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Full text of "Year book - Carnegie Institution of Washington"

C A R N E G I E I N S T I T U T I O N 



Cl : WASHINGTON 



Extending the Frontiers of Science 



1998-1999 












1 



i 





< 








Above: Microtubule structures formed in Xenopus egg extract are revealed by immunofluorescence analysis. 
(Courtesy Yixian Zheng, Carnegie Department of Embryology.) 

Below: This image shows the crystal structure of Phase D, MgSi 2 H 2 6 . The orange octahedra represent Mg0 6 
and the blue ones, SiCV This material has the highest known pressure-temperature stability of any hydrous sili- 
cate and may be present as a mineral in Earth's lower mantle. (Courtesy Charies Prewitt, Carnegie Geophysical 
Laboratory and David Palmer, The Open University, U.K.) 





wmm 






Year Book 98/99 



THE PRESIDENT'S REPORT 



July 1, I998 



June 30, I999 




}0 







26 



EOPHYSICAL LABORATORY 







CARNEGIE INSTITUTION 



O F WA SH1NGTON 




ABOUT CARNEGIE 




Department of Embryology 

1 1 5 West University Parkway 
Baltimore, MD 21210-3301 
410.467.1414 

Department of Plant Biology 

260 Panama St. 
Stanford, CA 94305-4101 
650.325.1521 

Geophysical Laboratory 

525 1 Broad Branch Rd., N.W, 
Washington, DC 20015-1305 
202.686.24 1 

Department of Terrestrial Magnetism 

524 1 Broad Branch Rd., N.W. 
Washington, DC 200 1 5- 1 305 
202.686.4370 

The Carnegie Observatories 

8 1 3 Santa Barbara St. 
Pasadena, CA 91 101-1292 
626.577.1122 

Las Campanas Observatory 

Casilla 601 

La Serena, Chile 

Office of Administration 

1 530 P St., N.W. 
Washington, DC 20005 
202.387.6400 

http://www.ciw.edu 




. . .TO ENCOURAGE, IN THE BROADEST AND 
MOST LIBERAL MANNER, INVESTIGATION, 
RESEARCH, AND DISCOVERY, AND THE 
APPLICATION OF KNOWLEDGE TO THE 
IMPROVEMENT OF MANKIND . . . 






The Carnegie Institution of Washington 
was incorporated with these words in 
1902 by its founder, Andrew Carnegie. 
Since then, the institution has remained 
true to its mission. At five research depart- 
ments across the country, the scientific 
staff and a constantly changing roster of 
students, postdoctoral fellows, and visiting 
investigators tackle fundamental questions 
on the frontiers of biology, earth sciences, 
and astronomy. 





ISSN 0069-066X 

Design by Hasten Design, Washington, DC 
Printing by Delancey Printing, Alexandria, VA 
January 2000 



1 ^L3 


ONTENTS 


The President's Commentary 




Losses, Gains, Honors 


E2H 


Contributions, Grants, and Private Gifts 




First Light and CASE 


22 


Department of Plant Biology 


26 


Department of Embryology 


44 


The Observatories 


6i 


Geophysical Laboratory 




Department of Terrestrial Magnetism 




Extradepartmental and Administrative 




Financial Statements 


^VTTT^I 


Index of Names 


^F^y «T^H 



"X/'ormer ^^residents O- cl/rust 



ees 



PRESIDENTS 

Daniel Coit Gilman, 1902-1904 
Robert S. Woodward, 1904-1920 
John C Merriam, 1921-1938 
Vannevar Bush, 1939-1955 
Car/I P. Haskins, 1956-1971 
Philip H. Abelson, 1971-1978 
James D. Ebert, 1978-1987 
Edward E. David, Jr. (Acting President, 
1987-1988) 

TRUSTEES 

Alexander Agassiz, / 904- 1 905 
Robert O. Anderson, 1976-1983 
Lord Ashby of Brandon, 1967-1974 
J. Paul Austin, 1976-1978 
George G. Baldwin, 1925-1927 
Thomas Barbour, 1934-1946 
James R Bell, 1935-1961 
John S. Billings, 1902-1913 
Robert Woods Bliss, 1936-1962 
Amory H. Bradford, 1959-1972 
Lindsay Bradford, 1940-1958 
Omar N. Bradley, 1948-1969 
Lewis M. Branscomb, 1973-1990 
Robert S. Brookings, 1910-1929 
James E. Burke, 1989-1993 
Vannevar Bush, \ 958-1 97 1 
John L. Cadwalader, 1903-1914 
William W. Campbell, 1929-1938 
John J. Carty, 1916-1932 
Whitefoord R. Cole, 1925-1934 
John T. Connor, 1975-1980 
Frederic A. Delano, 1927-1949 
Cleveland H. Dodge, 1903-1923 
William E. Dodge, 1902-1903 
Gerald M. Edelman, 1980-1987 
Charles P. Fenner, 1914-1924 
Michael Ference, Jr., 1968-1980 
Homer L Ferguson, 1927-1952 
Simon Flexner, 19 10-19 14 
W. Cameron Forbes, 1920-1955 
James Forrestal, 1948-1949 
William N. Frew, 1902-1915 
Lyman J. Gage, 1902-1912 
Walter S. Gifford, 1931-1966 



Carl J. Gilbert, 1962-1983 
Cass Gilbert, 1924-1934 
Frederick H. Gillett, 1924-1935 
Daniel C Gilman, 1902-1908 
HannaH. Gray, 1974-1978 
Crawford H. Greenewalt, 1952-1984 
William C Greenough, 1975-1989 
Patrick E. Haggerty, 1974-1975 
John Hay, 1902-1905 
Barklie McKee Henry, 1949-1966 
Myron T. Herrick, 1915-1929 
Abram S. Hewitt, 1902-1903 
Henry L Higginson, 1902-1919 
Ethan A. Hitchcock, 1902-1909 
Henry Hitchcock, 1902 
Herbert Hoover, 1920-1949 
William Wirt Howe, 1903-1909 
Charles L Hutchinson, 1902-1904 
Walter A. Jessup, / 938- 1 944 
Frank B. Jewett, 1933-1949 
George F. Jewett, Jr., / 983-1987 
Antonia Ax:son Johnson, / 980- 1 994 
William F. Kieschnick, 1985-1991 
Samuel P. Langley, 1904-1906 
Kenneth G. Langone, 1993-1994 
Ernest O. Lawrence, 1944-1958 
Charles A. Lindbergh, 1934-1939 
William Lindsay, 1902-1909 
Henry Cabot Lodge, 1914-1924 
Alfred L Loomis, 1934-1973 
Robert A. Lovett, 1948-1971 
Seth Low, 1902-1916 
Wayne MacVeagh, 1902-1907 
William McChesney Martin, 1967-1983 
KeithS. McHugh, 1950-1974 
Andrew W. Mellon, 1924-1937 
John C. Merriam, 1921-1938 
J. Irwin Miller, 1988-1991 
Margaret Carnegie Miller, 1955-1967 
Roswell Miller, 1933-1955 
Darius O. Mills, 1902-1909 
S. Weir Mitchell, 1902-1914 
Andrew J. Montague, 1907-1935 
Henry S. Morgan, 1936-1978 
William W. Morrow, 1902-1929 
SeeleyG. Mudd, 1940-1968 
Franklin D. Murphy, 1978-1985 
William I. Myers, 1948-1976 



Garrison Norton, 1960-1974 
Paul F. Oreffice, 1988-1993 
William Church Osborn, 1927-1934 
Walter H. Page, 1971-1979 
James Parmelee, 1 9 17-1 93 1 
William Barclay Parsons, 1907-1932 
Stewart Paton, 1916-1942 
Robert N. Pennoyer, 1968-1989 
George W. Pepper, 1914-1919 
John J. Pershing, 1930-1943 
Henning W. Prentis, Jr., 1942-1959 
Henry S. Pritchett, 1906-1936 
Gordon S. Rentschler, 1946-1948 
Sally K. Ride, 1989-1994 
David Rockefeller, 1952-1956 
Elihu Root, 1902-1937 
Elihu Root, Jr., 1937-1967 
Julius Rosenwald, 1929-1931 
William M. Roth, 1968-1979 
William W. Rubey, 1962-1974 
Martin A. Ryerson, 1908-1928 
Howard A. Schneiderman, 1988-1991 
Henry R. Shepley, 1937-1962 
Theobald Smith, 1914-1934 
John C Spooner, 1902-1907 
William Benson Storey, 1924-1939 
Richard P. Strong, 1934-1948 
Charles P. Taft, 1936-1975 
William H. Taft, 1906-1915 
William S. Thayer, 1929-1932 
Juan T. Trippe, 1944-1981 
James W. Wadsworth, / 932-1 952 
Charles D. Walcott, 1902-1927 
Frederic C. Walcott, 1931-1948 
Henry P. Walcott, 1910-1924 
Lewis H. Weed, 1935-1952 
William H. Welch, 1906-1934 
Gunnar Wessman, 1984-1987 
Andrew D. White, 1902-1916 
Edward D. White, 1902-1903 
Henry White, 1913-1927 
James N.White, 1956-1 979 
George W. Wickersham, 1909-1936 
Robert E. Wilson, 1953-1964 
Robert S. Woodward, 1905-1924 
Carroll D. Wright, 1902-1908 



iS^rust 



William I. M. Turner, Jr., Vice-Chairman 
David Greenewalt, Secretary 

Philip H. Abclson 

Euan Baird 

William T. Coleman, Jr. 

Tom Cori 

John F. Crawford 

Edward E. David, Jr., Emeritus 

John Diebold 

James D. Ebert 

W. Gary Ernst 

Sandra M. Faber 

Bruce W. Ferguson 

Michael E. Gellert 

Robert G. Goelet 

William T. Golden, Emeritus 

Caryl P. Haskins, Emeritus 

William R. Hearst III 

Richard E. Heckert, Emeritus 

William R. Hewlett, Emeritus 

Kazuo Inamori 

Suzanne Nora Johnson 

Gerald D. Laubach, Senior Trustee 

John D. Macomber, Senior Trustee 

Burton J. McMurtry 

Jaylee Mead 

Richard A. Meserve 

Richard S. Perkins, Emeritus 

Frank Press, Senior Trustee 

William J. Rutter 

Robert C. Seamans, Jr., Emeritus 

Frank Stanton, Emeritus 

Christopher T. S. Stone 

David F. Swensen 

Charles H. Townes, Emeritus 

Sidney J. Weinberg, Jr., Senior Trustee 






«*£y irecton 



Augustus Oemler, Jr. The Observatories 

Wesley T. I Iuntress, Jr., Geophysical Laboratory 

Sean C. Solomon, Department of Terrestrial Magnetisti 

Christopher Somerville, Department of Plant Biology 

Allan C. Spradling, Department of Embryology 

John J. Lively, Administration and Finance 

Susan nc Garvey, External Affairs 



CARNEGIE INSTITUTION 



page 8 Iyear book p£—pp 









Mg x if* ^Sm m 




The President's Commentary 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page p 



IT HAS SEEMED ALL DAY AS THOUGH MY HORIZON WAS NOT BIG ENOUGH TO HOLD ME. 

THIS MEANS THAT MY SOLE AMBITION FOR ME [THESE] LAST [FEW] YEARS IS ABOUT TO BE REALIZED. 

RARELY, I THINK ARE AIMS SO CLEARLY DEFINED IN LIFE AS MINE HAVE BEEN. 

EVER SINCE VISITING CHICHEN ITZA 7 YEARS AGO ... 

IT HAS BEEN MY FONDEST WISH TO SOMEDAY EXCAVATE THAT CITY." 

FROM THE DIARY OF SYLVANUS G. MORLEY, JANUARY 16, 1914, 
THE DAY HE WAS NOTIFIED OF HIS APPOINTMENT TO THE CARNEGIE INSTITUTION OF WASHINGTON. 



goal of this institution is to demonstrate, 
through excellence and originality, the nature of 
scientific research and its value to society. As 
implied by Vannevar Bush's phrase, "the endless 
frontier," it is a goal without inherent limits, 
though it is constrained by the realities of time and 
resources. Carnegie's trustees and charter do not 
tell us how to reach that goal. The one directive 
was given by Andrew Carnegie in his Trust Deed 
of January 28, 1902: "To discover the exceptional 
man in every department of study whenever and 
wherever found, inside or outside of schools, and 
enable him to make the work for which he seems 
specially designed his life work." As might be 
expected, my personal sensibilities have trouble 
with the exclusively male noun and pronoun. But 
with slight modifications, Carnegie's remarkable 
statement remains pertinent and inspiring. 

To some, the phrase "exceptional person" implies 
the solitary scientist, who develops personal ideas 
and works with her or his own hands. Our vision 
of the institution surely includes the nurturing of 
such people. But any too rigid a vision would con- 
fine our opportunities to attain the goal. Caryl 
Haskins expressed a broader vision when he wrote: 
"That high mobility within specific fields, that the 
unfettered crossing of fields, that the fashioning of 
unconventionally wide-ranging research programs, 
are subject only to the limitations imposed by 
Nature and by the judgements of gifted and dis- 
criminating investigators, and that making this 
mobility and flexibility possible is a principal objec- 
tive of the Institution." 1 Operationally and institu- 
tionally, the central word is "flexibility." Originality 
and excellence as well as the ideas of exceptional 
people will flourish under many circumstances. 




Sylvanus Morley (right) is photographed on the expedition of 
1915. He identified this picture only as "Scene in Camp." The 
other men are local workers who accompanied Morley. 



I was stimulated to think about these issues by the 
growing participation of Carnegie scientists in very 
large projects. Science is a pragmatic and oppor- 
tunistic venture. Contemporary science often 
requires the collaboration of large numbers of peo- 
ple and very substantial resources. Typically, if 
there is anything typical about research, such 
enterprises bring Carnegie scientists into elaborate 
cooperative consortia with colleagues from other 
institutions. Some of the projects depend on costly 
facilities that are provided and managed by federal 
agencies. Even the word "managed" makes the 
projects questionable in some minds. How can we 
decide if these projects are consistent with 
Carnegie's directive? The appropriate measures are 
the originality and excellence of the science as well 
as the opportunity for the Carnegie scientist to 
develop her or his ideas. 



o 



I Haskins, C. P., ed., The Search for Understanding, xvii, Carnegie Institution of 
Washington, Washington, D.C., 1967. 



Left: The planet Mercury is shown here. (Image courtesy of the Johns Hopkins University, Applied Physics Laboratory.) 



CARNEGIE INSTITUTION 



►age 10 I YEAR BOOK p8~pp 



THE INDIVIDUAL SCIENTIST 



As a small institution, we hold that our limited 
resources can make the largest and most distinctive 
contribution by providing for the maximum inde- 
pendent initiative by Carnegie scientists. In research 
institutions less capable of support, scientists are of 
necessity more prone to undertake research that is 
consistent at any given time with the aims of federal 
or private funding sources. Carnegie's unique posi- 
tion reflects decisions by generations of trustees to 
keep the institution small in order to sustain its 
independence. The massive growth of research 
universities over the last 50 years relied heavily on 
resources provided by the federal government. 
However, the customs and practices of these 
research universities, and of their now huge scientific 
communities, have a common origin with those of 
this institution. Even today, in an era of many team 
efforts, the scientific community and university 
administrators still require the evaluation of 
individual scientists' accomplishments. University 
appointment and promotion committees struggle 
to identify an individual's contribution to multiau- 
thored papers even when that is next to impossible. 
Individual contributions are formally recognized by 
the many prizes awarded for outstanding scientific 
work; almost always some collaborators are left out. 
The ideas and competence of individual scientists, 
as reflected in their grant proposals, are evaluated by 
peer review groups. The Carnegie Institution is 
similar in this respect. Regardless of the number of 
collaborators, our institution values the role of the 
individual investigator "suitably endowed and suit- 
ably protected, whose time, quite literally, is bought 
by the Institution and then returned as uncon- 
strained endowment." 2 We do want to know that 
our scientists are and remain intellectually suitably 
endowed and productive. 



COLLABORATIVE PROJECTS 



And yet, large, collaborative, and expensive projects 
have been part of the institution's programs since 



its earliest days. The scientific question might be 
formulated by one person, but making the research 
happen requires many people and various skills. 
The nonmagnetic ship Carnegie and its many voy- 
ages over 20 years was such a venture; it was pro- 
posed and promoted by L. A. Bauer, first director 
of the Department of Terrestrial Magnetism. 
Another scientist with a large vision was Sylvanus 
G. Morley. In 1914-15, the institution provided 
him with $3,000 to begin a survey of Mayan sites 
in Central America. Morley tramped the jungles 
for a decade and his annual support rose slowly, 
reaching $31,000 in 1924, when he recommended 
extensive excavations at Chichen Itza and a few 
other sites. By the 1930s, and in spite of the finan- 
cial difficulties brought on by the depression, 
Morley's project was receiving $150,000, more or 
less, each year for excavation and preservation of 
the artifacts. No longer a lone surveyor, his group 
grew to seven Carnegie Staff Members and a large 
number of laborers. Many hands and heads were 
needed to realize one man's dream. And the dream 
was only a starting point. Neither Morley nor any- 
one else could have predicted at the start just how 
much the expeditions would reveal. As huge as the 
undertaking was, it was small compared with what 
is needed today to undertake certain ripe and 
remarkably interesting projects. 




The nonmagnetic ship Carnegie, which took magnetic mea- 
surements between 1909 and 1929, is shown here in full sail. 



2 Ibid 



I 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page II 



A voyage to the planet Mercury is one such 
project. In the summer of 1999, Sean Solomon 
learned that NASA approved the proposal made 
by him and a consortium from 12 other institu- 
tions for a mission to Mercury. The craft will 
depart in 2004 and arrive in orbit around the plan- 
et in 2009 after two flybys of Venus and two of 
Mercury itself. A lot of the challenge and expense 
of the new project is in the engineering and con- 
struction of the space probe and the scientific 
instruments. The majority of the almost $290 
million cost will be spent at the Applied Physics 
Laboratory (APL) and several firms. But the point 
of the whole thing is to answer basic questions 
about the innermost planet of the solar system. As 
chief scientist and principal investigator, Solomon 
will provide the leadership. To what extent is this 
Solomon's science in the sense that the Chichen 
Itza excavation was Morley's science? 

The Mariner 10 mission in 1974 and 1975 was the 
last and only time Earth visited Mercury. Unlike 
Morley, Solomon could only reconnoiter his target 
by tramping in his own mind. He began to formu- 
late his research plan for Mercury 25 years ago, 
soon after the Mariner 10 mission. He wrote that 
the remaining fundamental questions then includ- 
ed, "Why is Mercury so different from the other 
terrestrial planets in bulk composition, geological 
evolution, and magnetic field? To what extent are 
those differences attributable to the planet's prox- 
imity to the Sun or to some other explanation?" 
He collaborated in devising a scientific strategy for 
further exploration of the planet, although the 
required technology did not exist. That is where 
things stood until a few years ago when the 
Applied Physics Lab came up with a feasible tech- 
nical plan for a Mercury orbiter. 

Solomon's published ideas as well as his experience 
with a Venus mission in the intervening years 
made him an obvious candidate for scientific lead- 
ership. Together, Solomon and APL recruited 
additional members for the science team. These 
other scientists contributed their own ideas and 
then Solomon defined the scientific goals and 
rationale, including the six core questions the mis- 
sion will address. These questions reflect those 
Solomon set out more than 20 years ago: What is 




Department of Terrestrial Magnetism Director Sean 
Solomon is pictured with a model of the MESSENGER craft. 



the origin of Mercury's high density? What are the 
composition and structure of its crust? Has 
Mercury experienced volcanism? What are the 
nature and dynamics of its thin atmosphere and 
Earth-like magnetosphere? What is the nature of 
its mysterious polar caps (are they made of water 
ice or sulfur or something else)? Is a liquid outer 
core responsible for generating its magnetic field? 



THE INDIVIDUAL AS COLLABORATOR 



To what extent does Solomon's role in the new 
mission to Mercury reflect our institutional expec- 
tations of the individual scientist? Solomon will 
acquire data to help answer questions he has long 
pondered: What can we learn about how Mercury 
was formed, and how has the planet's surface been 
modified by volcanic and tectonic processes? Other 
scientists will concentrate on other questions, 
including those concerning the planetary atmos- 
phere and magnetosphere. Like Morley, who 
recruited experts in hieroglyphs, architecture, 
ancient agriculture, and ceramics, Solomon's collab- 
orators will help him make the most of the freedom 
he has as a Carnegie scientist by taking advantage 
of the extraordinary opportunity NASA is provid- 
ing to scientists interested in our solar system. His 
initiative and management of the mission mark 
Solomon as an exceptional individual in one sense. 
But the crux of the matter relates to his science. 



CARNEGIE INSTITUTION 



PAGE 12 I YEAR BOOK p8~pp 



o 



The Mercury project, dubbed MESSENGER, is 
just beginning. Carnegie astronomers have, for 
almost a decade, provided leadership to another 
huge endeavor that is now nearing completion: the 
Key Project of the Hubble Space Telescope, the 
evaluation of the Hubble constant. Edwin 
Hubble's name is attached to this constant num- 
ber, H, because he was first to recognize that the 
velocity, v, with which objects in the universe 
move away from us increases in proportion to the 
object's distance, d, from us. Thus, v = Hd. 
Publications reporting the results of the Key 
Project typically have more than 20 authors. In 
what way was the science driven by the 
Observatories' Staff Member Wendy Freedman, 
who is described in NASA announcements and 
the press as the team leader? 




t^^jV?*-> 










Wendy Freedman is an Observatories Staff Member and 
leader of the Hubble Space Telescope Key Project on the 
Extragalactic Distance Scale. 



As a graduate student, Freedman had used 
Cepheid variable stars to measure the distances to 
nearby galaxies. This was an established method for 
determining the distance scale of the universe, and 
thus the distance, d, of objects. The distance scale 
needs to be known with confidence if the Hubble 
constant, H, is to be evaluated. Newly available 
technologies allowed Freedman to correct errors 
inherent in earlier methods, including the nonlin- 
earity of measurements of brightness on photo- 
graphic plates and the effect of galactic dust, which 
make the Cepheids appear fainter and thus farther 
away than they really are. She, often in collabora- 




tion with her husband, Barry Madore, continued to 
refine the methods when she came to the Carnegie 
Observatories, first as a postdoctoral fellow and 
later as a Staff Member. In 1984, she presented 
new results on the distance scale at a meeting where 
it was also announced that plans for Hubble Space 
Telescope science included a Key Project to evalu- 
ate the Hubble constant. Freedman joined with 10 
other astronomers to prepare a proposal for the 
competition. She was a central figure in the group 
because she had unique experience with the new 
techniques and distance measurements. By 1990, 
when, after long delays in the launch time, the 
Space Telescope Science Institute finally accepted 
proposals, Freedman had become the chief scientist 
on the project. In the intervening years, she and 
Madore had refined techniques to enhance the effi- 
ciency of the observations and thus significantly 
decrease the required telescope time. The proposal 
was successful, and data collection began in 1991. 
By 1994, the science and the management of the 
project had become complex and time consuming, 
and more scientists joined. More than 27 people 
were finally involved, including Madore, now a 
Senior Research Associate at the Observatories, and 
DTM Staff Member John Graham, both of whom 
were two of the original team members. 

In this instance, Freedman had laid the ground- 
work for an improved approach to a long-standing 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 13 



problem of fundamental interest to all astrophysi- 
cists. The Hubble Telescope was essential if she 
was to advance her scientific interests. That 
requirement necessitated joining a national effort 
in which scientific and technical managers played 
critical roles and a score of astronomers were kept 
busy. The complexity of the research, its scientific 
importance, and public interest in the outcome 
made it essential to have many people bring differ- 
ent skills and talents to the problem, if the pre- 
cious time on the telescope was to be well used. 
Again, the analogy with Morley's Earth-bound 
science is striking. For Freedman, as for Morley 
and Solomon, personal scientific questions defined 
the road map for exploration. 

The mission to Mercury and the Hubble Key 
Project have in common a dependence on large, 
very expensive instruments that cannot be built, 
maintained, or operated by single institutions. The 
Las Campanas Observatory defines the largest 
such facility that the Carnegie Institution could 
reasonably undertake. Few other private institu- 
tions, can match what generations of Carnegie 
astronomers and trustees have built at Las 
Campanas. In the last few years, with the con- 
struction of the Magellan telescopes, we have rec- 
ognized that if we are to exploit in the future the 
opportunities for modern research provided by Las 
Campanas, we cannot do it ourselves. New science 
demands new, complex, and costly technology. 
Collaborators and consortia are necessary if Las 
Campanas is to be a significant source of new sci- 
ence in the new century. We will regret the loss of 
the unique independence and informal style of Las 
Campanas. Miguel Roth and the mountain staff 
will strive to sustain the spirit of the place in the 
new situation. But to do original and excellent sci- 
ence, change will be necessary, change that can, if 
we are not attentive, diminish the role of the 
exceptional individual. 



COLLABORATIONS BRIDGE DISCIPLINES 



Similar changes, on a much smaller scale, are 
occurring in other sciences. These are driven not 



so much by the need for enormous and expensive 
facilities as by the requirement for a variety of 
techniques and expertise to obtain answers to fun- 
damental questions. Sometimes an individual 
investigator can educate herself to handle all the 
challenges. Other times, collaborations make 
sense. The need for collaborations or for learning 
new methods is a sign that research is bridging 
more than one traditional discipline. And often 
this signifies great originality. The probability of 
major advancements in understanding is increased 
when scientists cross disciplinary boundaries. The 
astrobiology initiative at DTM and GL is an 
example of such an interdisciplinary endeavor. An 
example in biology is the growing collaboration 
between computer scientists and biologists directed 
at understanding the sequenced genomes of many 
organisms. At the Department of Plant Biology, 
Chris Somerville is establishing a new program in 
bioinformatics, which will adapt new computer 
technology for the study of the genome of the 
model plant, Arabidopsis. .Allan Spradling has 
helped to foster similar developments through his 
participation in the Drosophila community, 
although the work itself is not part of the program 
at the Department of Embryology. The ecological 
studies of Chris Field and Joe Berry at Plant 
Biology are also highly dependent on computer 
modeling. Biological studies increasingly cut across 
disciplinary lines that were once quite rigid. 

These changes in the way Carnegie science is done 
are evident in the bibliographies in the recent 




CARNEGIE INSTITUTION 



I 



page 14 I YEAR BOOK p8~pp 



Carnegie Year Books. As many as 25 authors are 
listed on the papers reporting the results of the 
Hubble Key Project. Few papers have single 
authors. Alan Boss and George Wetherill, both of 
whom model aspects of solar system and planet 
formation, publish on their own, as do others on 
occasion. Most papers have five or fewer authors. 
Counting papers on which Staff Members are 
authors, the averages are 3.6, 4.8, 3.3, 4.7, and 
3.0 for Embryology, the Observatories, the 
Geophysical Lab, Plant Biology, and DTM, 
respectively (omitting the few papers with more 
than 15 authors). Frequently, the additional 
authors are scientists in other institutions. 

In the two biology departments, the coauthors are 
usually postdoctoral fellows or graduate students. 
These two departments, which have the smallest 
number of Staff Members, have the highest num- 
ber of postdoctoral fellows per Staff Member: four 
in Embryology and three in Plant Biology. But the 
number of postdoctoral fellows per Staff Member 
is related less to the small number of Staff 
Members than to the dependence of modern bio- 
logical research on intensive, time-consuming 
experimental work and the many different tech- 
niques required for definitive answers to the ques- 
tions being asked. The modern biologist can no 
longer simply be a geneticist, a cell biologist, a 
physiologist, a microscopist, a biochemist, or an 
ecologist. Many of the most original investigations 
require that a scientist be many of these simultane- 
ously or engage the collaboration of those who can 
contribute the needed skills. 



LARGE LABS ARE NOT NECESSARILY 
BETTER LABS 



It is not only at Carnegie that independent investi- 
gators such as our Staff Members orchestrate the 
activities of a group. Groups in other institutions 
are frequently much larger than ours, though not 
necessarily as productive. More than 10 years ago, 
public discussion of concerns about the growing 
size of research groups in biology was initiated by 



Bruce Alberts. 3 At the time, Alberts was professor 
of biochemistry at the University of California, 
San Francisco. Now he is president of the National 
Academy of Sciences. Alberts argued that large 
research groups were inefficient because they 
increased the time that the leader had to spend on 
nonintellectual endeavors such as raising funds and 
finding jobs for members of the group, thereby 
leaving less time for thinking and reading. Alberts 
also said that large laboratories are a "poor training 
environment" for preparing young scientists for 
independent research careers. He provided only a 
couple of hints regarding his definition of a large 
laboratory. It seems to lie somewhere between 5 
and 15 members. Staff Members at the two 
Carnegie biology departments have, on average, 
smaller groups than Alberts's lower limit. But 
before we take any comfort in that, we should con- 
sider the other side of the picture. That other side 
was expressed in responses to Alberts from two 
other distinguished biologists. 

Paul Schimmel thought Alberts's statement was 
simplistic. Schimmel reviews the many different 
kinds of technical competencies and number of 
operations required to carry out certain biological 
investigations and concludes, "For some projects, 
the research simply demands a scale that is larger 
— for reasons of effectiveness and efficiency." 4 
A few weeks later, Jan Klein of the Max-Planck- 
Institut fur Biologie in Tubingen weighed in with 
a more extreme view: "What these many com- 
plainers do not seem to understand is that large 
research groups have become a historical necessity 
... If a small laboratory could afford all this [neces- 
sary] equipment, it would not be able to use it effi- 
ciently. It would be comparable to a farmer who 
has acquired a combine to harvest ten acres of 
land. Only in a large laboratory can questions 
requiring multifaceted approaches be posed [and 
answered]." 5 Klein has a point, but only if one 
examines his assumptions. The large laboratory he 
describes seems to stand alone, with little commu- 
nication or sharing with nearby colleagues. He fails 
to recognize that mutual collegiality can also 
enlarge the intellectual and instrumentational 
competencies of small groups. Perhaps shared 



3 Alberts, B., Limits to growth: in biology, small science is good science, Cell 41, 337-338, 1985. 

4 Shimmel, P., In biology, neither smaller or larger is necessarily better, Cell 42, 1 , 1985. 

5 Klein, j„ Big may not be beautiful, but it is necessary, Cell 42, 395-396, 1 985, 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp page JJ 



instruments and facilities were not part of his insti- 
tution's traditions, as they are at Carnegie labs. In 
spite of their small size and small groups, the 
Carnegie biology labs have demonstrated that 
multifaceted investigations can be carried out by 
small groups with extraordinary success and effi- 
ciency. Moreover, though it might seem counter- 
intuitive to some, the independence of individual 
investigators can thrive in a cooperative scientific 
community. 



THE ROLE OF POSTDOCS 



At Carnegie as well as in larger biology laboratory 
groups, much depends on the hard, sometimes 
tedious work of postdoctoral fellows and associates. 
The overall goals of the research project are gener- 
ally those of the senior scientist, vetted through the 
peer review of a granting agency. What do the stu- 
dents and postdoctoral fellows gain in return for 
their long hours at the bench and adherence to the 
general program set by someone else? First of all, 
they should acquire new knowledge, expertise, and 
insights into how to define, shape, and carry out 
research projects. In the best of circumstances, 
they, together with their mentors, form lively colle- 
gial groups that generate new questions and 
approaches in the framework of the established 
goal. If they are lucky enough and smart enough, 
the young scientists may discover something that 
changes the direction of the whole project. The sci- 
ence benefits from their youthful iconoclasm. What 




o 



Shauna Somerville (left) with postdoctoral fellow John Vogel. 



happens to the Staff Member, one of Carnegie's 
exceptional people, in the organization of modern 
biological research? The outcome of each research 
project is the result of the thinking, analysis, and 
hard work of a group of at least two people: the 
Staff Member, serving as mentor, and one student 
or postdoc. Even the participants may find it diffi- 
cult to sort out who had which important idea, and 
if their relationship is healthy, they don't spend a 
lot of time worrying about it. But the initial input, 
the framing of the question, the general road map, 
these more than likely reflect the vision of the indi- 
vidual exceptional person. 

In the physical sciences, postdoctoral fellows are 
more frequently independent researchers, interact- 
ing as colleagues with other postdocs and Staff 
Members, but not necessarily as collaborators on a 
particular project. That accounts, at least in part, for 




the fact that at the Observatories, the Geophysical 
Lab, and DTM the numbers of postdoctoral fel- 
lows and Staff Members are about equal. 

Flexibility remains essential in the organization 
and management of any institution for research. 
At Carnegie, flexibility is assured by the indepen- 
dent operations of the five departments and by 
emphasis on the freedom of individual scientists to 
follow their own lights. 

— Maxine F. Singer 
November 1999 



CARNEGIE INSTITUTION 



page l6 I YEAR BOOK p8~pp 



LOSSES 



, manager of grants and resources at the Observatories, died February 5. He was with 
Carnegie for over 20 years. 



>n, a longtime employee at the Department of Plant Biology, died this past spring. 



szyk died on March 21. He was the machine shop foreman at the Geophysical Laboratory and 
had been with Carnegie since 1980. 



nas, animal-care technician for the Department of Embryology, died on November 11. James 
came to the department in 1994. 

RETIRING 



i T. Golden stepped down from the board after 30 years of service to 
become a trustee emeritus. The board honored him for his years of service by 
naming the Observatories' auditorium in Pasadena, California, the William T. 
Golden Auditorium. 



Four trustees were named senior trustees: Gerald D. Laubach, John D. 
Macomber, Frank Press, and Sidney J. Weinberg, Jr. 



irkman retired from the Department of Plant Biology in July. He was 
guest of honor at a symposium in August that highlighted some of the areas where 
his research on plant physiology has had an impact. Held in California's wine country, 
the symposium was attended by nearly 50 of Olle's friends, students, and colleagues. 




inger, a Geophysical Laboratory Staff Member since 1969, retired in July. 
He arrived at the lab in 1967 as a postdoctoral fellow and was appointed staff crys- 
tallographer two years later. A symposium to honor him and Charles Prewitt was 
held at the administration building in April. It was entitled "Mineralogy at the 
Millennium" and was attended by over 135 participants. The event identified a 
number of new opportunities in experimental and theoretical studies of Earth 
and planetary materials, areas in which Larry and Charlie have had major 
influence worldwide. 









i ^^ 


i 


M 


Larry Finger 



["Ed") retired from the Geophysical Laboratory in October 1998. 
A conference was held in his honor at the American Geophysical Union headquar- 
ters in April 1998. The conference, entitled "Perspectives in amino acid and protein 
geochemistry," was a great success and a fitting tribute to Ed's significant scientific 
contributions. 



, Department of Plant Biology secretary/receptionist for more than 20 
years, retired in September 1999. 



' 


1 




hf\ 


/a 


^^w- | 


P. Edgar Hare ("Ed") 



■ 



CARNEGIE INSTITUTION 



YEARBOOK^?- 99 page IJ 



Brian Welsh, mechanical engineer at the Department of Plant Biology, retired in June. 



Joan Gantz, Observatories' librarian since 1976, retired on June 30. 



GAINS 



The board elected Tom Cori as a new trustee at its May meeting. Dr. Cori is the 
chairman and CEO of Sigma-Aldrich Corporation in St. Louis, Missouri. 



Jay lee Mead was elected to the board of trustees at the May board meeting. 
Dr. Mead is a Washington, D.C., resident and a retired astronomer from NASA 
Goddard Space Flight Center. She is very active in the Washington arts and 
philanthropy. 



Paul Butler is the newest Staff Member at DTM. He was previously with the 
Anglo-Australian Observatory in Sydney, Australia. Along with his colleague Geoff 
Marcy, Paul has discovered two-thirds of the known extrasolar planets, including the 
only known system of multiple planets orbiting a Sun-like star. 




Tom Cori 



Two new Staff Members joined the Observatories this year. John Mulchaey received 
his Ph.D. in 1994 from the University of Maryland. A former Carnegie Fellow at the 
department, his work focuses on galaxies and their clustering. Michael Rauch 
received his Ph.D. in 1993 from Cambridge University. He is a former Observatories 
postdoctoral fellow; his studies include QSO absorption-line systems and the large- 
scale structure of the universe. At Las Campanas in July 1998, Mark Phillips was appointed 
Associate Director. 




Jaylee Mead 



Mikhail Eremets is a new Senior Research Scientist at the Geophysical Laboratory. 
He is working in the field of high-pressure research with Dave Mao and Rus Hemley. 



Terence Murphy is the newest Staff Associate at Embryology. His work focuses on 
chromosome inheritance and epigenetic aspects of centromere function. 



Tina McDowell succeeded Pat Craig as editor and publications officer in February. 
Tina comes to Carnegie from Time-Life Books, where she was editorial director for 
science, nature, and health. 




TRANSITIONS 



Francois Schweizer, a DTM Staff Member since 1981, has transferred to the Observatories, where he 
will continue his work in observational astrophysics, the structure and evolution of galaxies, and the cosmic 
distance scale. 



CARNEGIE INSTITUTION 



page 1 8 I YEAR BOOK p8~pp 



HONORS 



Trustee S was elected a fellow of the California Academy of Sciences. 



The 1999 Harvard Business School Alumni Achievement Award was given to trustee Bruce Ferguson 
at a ceremony in June. 



I Meserve, also on the board, was confirmed by the Senate in October to be the new head of the 
Nuclear Regulatory Commission. 



Trustee William Rutter received the Biotechnology Hall of Fame special recognition award in 
October 1998. 



vnes, trustee emeritus, received the Mendel Medal from Villanova University. 



Maxine F. Singer received the Vannevar Bush Award from the National Science Board of the National 
Science Foundation in May. The award was established in 1980 to honor the leadership of a distinguished 
senior scientist and statesperson. It is the highest honor bestowed by the board, and Dr. Singer is the first 
woman ever to receive it. 



ssley T. Huntress, Jr., director of the Geophysical Laboratory, was reelected president of the American 
Astronautical Society and was appointed a distinguished visiting scientist at the Jet Propulsion Laboratory. 
Huntress also received the Caltech Management Association's Excellence in Management Award for 1999. 



ean Solomon, director of the Department of Terrestrial Magnetism, was the 1999 recipient of the G. K. 
Gilbert Award from the Geological Society of America. This award is presented annually for outstanding 
contributions to the solution of fundamental problems in planetary geology. Solomon also received a fellow- 
ship from the Japan Society for the Promotion of Science to visit and give lectures at the Earthquake Research 
Institute, the Ocean Research Institute, the Institute of Space and Astronautical Science, the universities of 
Tokyo, Hokkaido, and Kyushu, and the annual meeting of the Japanese Society for Planetary Sciences. 



Iriggs, Director Emeritus at Plant Biology, received two lectureship awards. He was selected as 
the Anton Lang Memorial Lecturer at Michigan State University in March, and was chosen to give the 
Philip C. Hamm Memorial Lecture at the University of Minnesota in May. 



Staff Member at Embryology Joe Gall received the J. E. Purkinje Honorary Medal for Merit in the 
Biological Sciences awarded by the Academy of Sciences of the Czech Republic. 



*n, Staff Member at Embryology, was elected to the board of directors of the Society for 
Developmental Biology as the junior faculty representative. 



, a Staff Associate at Embryology, received the John Merck Scholarship in the Biology of 
Developmental Disabilities in Children. 



lez Alvarado, Staff Associate at Embryology, received the Marcus Singer Medal for 
research in regeneration at the Midwest Society for Developmental Biology in May. 



CARNEGIE INSTITUTION 



YEARBOOK^?- 99 page Ip 



The American Society for Cell Biology's Women in Cell Biology Committee has awarded Embryology Staff 
Member Yixian Zheng its 1999 Junior Award. The award is one of the top honors from the society, and it 
recognizes Yixian's outstanding scientific contributions using Xenopus and Drosophila systems. 



Observatories Staff Member Alan Dressier received NASA's Medal for Public Service in recognition for his 
"extraordinary scientific leadership in developing the NASA Origins theme by producing the report, 
'Exploration and the Search for Origins,' and communicating it brilliantly." 



The lodge at Las Campanas was named in honor of Horace Babcock, emeritus member of the Observatories 
and former director of the then jointly operated observatories of Carnegie Institution and Caltech from 1964 to 
1978. Babcock arrived at Carnegie as a Staff Member in 1946; while director of the Observatories he was one 
of the leaders in Carnegie's founding and early development of the Las Campanas Observatories. 



Bill Pike, a Geophysical Laboratory summer intern in 1998, was awarded the 1999 Geological Society of 
America Stephen E. Dwornik Student Paper Award for his paper entitled "Melting temperatures in the 
Fe-Ni-S system at high pressures: implications for the state of the Martian core." This research was done 
in collaboration with Yingwei Fei and Connie Bertka. Alexander Berengaut, also a lab intern and a high 
school student, worked with Connie Bertka on a project entitled "The formation of symplectic exsolutions in 
Martian meteorites: implications for the petrologic history," and was a semifinalist in the Intel Science Talent 
Search. He also represented Montgomery County, Maryland, at the International Science Fair. 



CARNEGIE INSTITUTION 



PAGE 20 I YEAR BOOK p8~pp 



ward Tomorrow's Discover 



The Carnegie Institution received gifts 
and grants from the following individuals, 
foundations, corporations, and government 
agencies during the period from July I, 
1998, to June 30, 1999. 



1 



$100,000-$ I million 

Anonymous 

Arcana Foundation, Inc. 

The Morris and Gwendolyn 

Cafritz Foundation 
Damon Runyon-Walter 

Winchell Foundation 
DDI Corporation 
Howard Hughes Medical 

Institute 
Kimsey Foundation 
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Kyocera Corporation 
The John Merck Fund 
The Ambrose Monell 

Foundation 
The Ruth and Frank Stanton 

Fund 
The Starr Foundation 
Sidney J. Weinberg, Jr. 

Foundation 



$10,000 to $99,999 

Abbott Laboratories Fund 
Fundacion Andes 
Baxter International Inc. 
Carnegie Institution of 

Canada/Institution Carnegie 

du Canada 
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Dreyfus Foundation, Inc. 
Fannie Mae Foundation 
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Golden Family Foundation 
Philip L. Graham Fund 
David Greenewalt Charitable 

Trust 
William Randolph Hearst 

Foundation 
Richard W. Higgins 

Foundation 
Humana, Inc. 
Johnson & Johnson Family of 

Companies 
Suzanne and David Johnson 

Foundation 
Life Sciences Research 

Foundation 
Richard Lounsbery 

Foundation 



The G Harold and Leila Y. 

Mathers Charitable 

Foundation 
Eugene & Agnes E. Meyer 

Foundation 
The Pew Scholars Program 
The Pfizer Foundation, Inc. 
Frederick P. and Sandra Rose 

Foundation 
Six Flags 
The William and Nancy 

Turner Foundation 
The Helen J. Urban & 

Thomas N. Urban, Sr. 

Charitable Foundation 



$1,000 to $9,999 

The Berger Family Trust 
Eli Lilly and Company 

Foundation 
The Charlotte and Gary 

Ernst Fund 
Paul and Annetta Himmelfarb 

Foundation 
Nina and Ivan Selin Family 

Foundation 
Roslyne C Swig Philanthropic 

Fund 



Under $1,000 

Berkshire Hathaway Inc. 
Esquire Settlement 

Services, Inc. 
John Collins Harvey Trust 
Keith Family Revocable Trust 
Telecommunication 

Networks Consulting 




$100,000 to $1 million 

Michael E. Gellert 
Richard E. Heckert 
Kazuo Inamori 
William I. Rutter 



$10,000 to $99,999 

Philip H. Abelson 
L. Thomas and Margaret G. 
Aldrich 



Anonymous 

Diane and Norman Bernstein 

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Charles Ellis 

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Mr. and Mrs. Robert G. 

Goelet 
David Greenewalt 
Robert and Margaret Hazen 
Paul Johnson 
Gerald D. Laubach 
Burton J. and Deedee 

McMurtry 
Richard A. and Martha K 

Meserve 
Evelyn Stefansson Nef 
Robert J. and Vera C Rubin 
Dan and Maxine Singer 



$1,000 to $9,999 

Horace W. Babcock 

Jordan Baruch 

Donald D. and Linda W. 

Brown 
John F. Crawford 
Howard C and Eleanora K. 

Dalton 
Edward E. David, Jr. 
John Diebold 
Alan Dressier 
Jo Ann Eder 

Sandra and Andrew Faber 
Andrew Fire 
Pembroke J. Hart 
William R. Hearst III 
Martha Hoering 
Paul N. Kokulis 
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Alvin E. and Honey W. 

Nashman 
Frank Press 
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Seamans, Jr. 
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Allan Spradling 
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Dr. and Mrs. Yoshiaki Suzuki 
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W. John R. and Mendelle 

Tourover Woodley 



Under $1,000 

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Bennett 
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Bertani 
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Todd and Caroline Brethauer 
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John R. and Muriel H. Cronin 
Igor B. and Keiko Ozato 

Dawid 
Vincent De Feo 
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John Dilley 
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Richard Dunlop 
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Jeremiah J. Evans 
Dorothy Ruth Fischer 
Oscar and Toby Fitzgerald 
Marilyn L Fogel 
Charles and Kathleen Frame 
Fred S. Fry, Jr. 
David A. Fuss 
Arthur W. Galston 
David and Carolyn Gambrel 
Barry Ganapol 



Toward Tomorrow's Discoveries 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 21 



Ralph and Jane Geuder 
John Gibbons 
Kirsten and Oliver 

Gildersleeve, Jr. 
James F. Goff 
Jeffrey T. Green 
Richard and Irene Grill 
Richard and Roberta Gross 
Necip Guven 
Ralph Haag 

Arthur and Louisan Hagen 
Shirley A. Hargraves 
Stanley R. Hart 
William K. Hart 
Richard and Catherine 

Hartman 
Gordon and Beverly Hawkins 
Norris C Hekimian 
H. Lawrence Heifer 
Stewart and Lurette Henley 
Michael Hensley 
Mr, And Mrs. D. L Hersh 
John and Ann Hess 
Walter Holemans 
Vaclav Horak 
Martha Pardavi-Horvath 
Satoshi Hoshina 
Charles B. Hunter 
Pauline Innis 
Edwin Istvan 
Emiliejager 
Robert Jastrow 
Gary L Joaquin 
Sandy Keiser 
William and Julia Kerr 
Mark E. and Peggy A. Kidwell 
J.B.Kim 
Roger Knight 
Olavi Kouvo 
Audrey Krause 
Otto C. and Ruth Landman 
Arthur and Faith W. LaVelle 
Kurt Lawson 

Harold and Wei Soong Lee 
Arthur and Marjorie 

Levenson 
Robert Levis 
Harlan Lewis 

Steven and Nancy L'Hernault 
Sou-Yang Liu 
Felix J. Lockman 
Ruth Logue 
Eric Long 
Quentin Looney 
Richard A. Lux 
Billie Bryan Mackey 
W. Richard Mancuso 
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Glenn B. Marcus 

Charles and Barbara Marks 

Chester B. and Barbara C 

Martin, Jr. 
Irene and Egon Marx 
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James M. Mattinson 
David and Judith Mauriello 
Timothy McCauley 
Sheila McCormick 
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Lowell and Ruth Minor 
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Andrew and Teresa Murphy 
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Joseph and May Nakamura 
Russell T Nevins 
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Peiser 
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Robinson 
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Jerome and Rose Snyder 

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Lee Morrison 
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More than $1 million 

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Institute 
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Space Administration 



$10,000 to $99,999 



American Cancer Society 
Biosphere Two Center, Inc. 
International Human Frontier 
Science Program 



k .'v \$ ft 
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CARNEGIE INSTITUTION 



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First Light and The Carnegie Academy 
for Science Education 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 2$ 



Carnegie Science Education: 
Becoming Part of the Story of Science 



"When I examined myself and my methods of thought I came to the 
conclusion that the gift of fantasy meant more to me than my talent 
for absorbing positive knowledge." 

Albert Einstein 



Ejs humans, we are the carriers of the knowledge 
and experience of the past. This truth shapes tra- 
ditional science education, which is typically about 
past discoveries made by someone else. But as 
individuals, we are always making discoveries for 
ourselves. First Light and CASE (in their 12th 
and 6th years, respectively) seek to expand tradi- 
tional science education by developing the capacity 
of both youngsters and grown-ups to make 
insightful discoveries about the world around 
them. By doing so, the students become a part of 
the story of science and experience firsthand its 
curiosity, discovery, and surprise. 

Ironically, many schools insulate students against 
surprise — especially in science education. Educators 
craft textbooks, handouts, and work sheets so care- 
fully that often there is nothing left to discover, no 
personal role for the student except to learn the 
story of what others have done. To be truly educated 
however, is to learn things for oneself. 

In contrast, science education at Carnegie is an 
adventure celebrating the thoughts, products, and 



involvement of the students. We encourage pupils 
to ask questions and develop procedures for draw- 
ing their own conclusions. Where the traditional 
model skips to the end of the story, the Carnegie 
model stimulates students to become part of the 
story. 

To learn the story of science requires, above all, a 
highly developed imagination. Perhaps more 
important than any concept we teach, is to spark 
the imagination and curiosity of students so that 
they want to take the questions of the past and 
explore them today. 

The study of electricity provides an example. The 
traditional approach is to describe the discovery of 
electricity and the invention of the first electric 
devices. At Carnegie this is just the beginning. 
Students here participate in the phenomenon of 
electricity by harnessing its use through making 
and testing batteries, experimenting with resis- 
tance, and applying it to various problems. 



Left: Weekly field trips at First Light often provide the materials for unique investigations. Here students learn how natural resources 
were used in everyday life. 



CARNEGIE INSTITUTION 



page 24 I YEAR BOOK p8~pp 



Following in the Footsteps of Scientists 

Because Carnegie has five research departments, 
students here have an added advantage: they can 
learn science by following in the footsteps of real 
scientists. One exciting new area under investiga- 
tion involves ocean life. This topic was first cov- 
ered at First Light over a decade ago. Students this 
year took a fresh look at the subject in conjunction 
with the institution's work in astrobiology. 
Astrobiology is a multidisciplinary field, carried 
out at Carnegie and elsewhere, to discover the ori- 
gins and distribution of life in the universe. One 
component is to look at the evolution of ocean life. 
Over the next three years, the research conducted 
by Carnegie scientists will be translated into activi- 
ties for youngsters and posted on a new Web site 
beginning in the spring of 2000. Students will 
explore the same fundamental questions the 
scientists will, such as how other biospheres can 
be recognized and how habitable worlds form 
and evolve. 

Learning by Doing 

To introduce the subject of ocean life to the stu- 
dents this year, we initiated a discussion on seawa- 
ter and salinity. First, we asked them how we 
could measure the salt in salt water. A great idea 
emerged, which focused on evaporation: If you 
take a known quantity of water and evaporate it, 




you will be left with the salt, which can be 
weighed. The class did just that by creating vary- 
ing concentrations of salt water, evaporating it, 
and weighing the remaining salt. 

Another topic that emerged has to do with densi- 
ty. The class noted that it is easier to float in sea- 
water than in freshwater. To understand why this 
is so, we put an egg into a beaker of water and 
examined what happened to it as salt was added. 
Several youngsters thought that the salinity of sea- 
water could be measured by observing how the egg 
was suspended in the water. 

The students wanted to experiment with some- 
thing else. We took a plastic pipette and filled the 
bulb portion with different kinds of materials: 
copper, steel, lead, and plastic shot. In essence, we 
created a crude but effective hydrometer for com- 
paring densities. But we lacked a way to make 
measurements. One child observed, "It's like a 
thermometer without any numbers." We needed 
to devise a scale and a method for calibrating it. 
The class agreed to mark the hydrometer in mil- 
limeters with the baseline level set by water. We 
could then measure density changes from one 
experiment to another. What did the youngsters 
want to test with the new instrument? They 
immediately suggested different liquids — coke, oil, 
and alcohol. The class had developed the tools that 
paved the way for the true inquiry, and the ques- 
tions they posed were many: Why were there dif- 
ferences among liquids? Did temperature change 
the results? Did mixing two liquids with known 
densities change the density of the new solution? 
Would sugar produce a liquid as dense as salt? As 
each new test was performed, a new act in the 
story of science unfolded. In two short hours, the 
class explored questions and experienced concepts 
related to investigative protocol, instrumentation, 
calibration, measurement, density, temperature, 
and fair testing. In that one class, the students 
lived a complete science story. 

The Foundation for Inquiring Minds 

Imagination, curiosity, and inquiry provide the most 
important foundations for studying science. Albert 
Einstein recognized this when he wrote, "When I 



■ 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 2$ 



examined myself and my methods of thought I 
came to the conclusion that the gift of fantasy 
meant more to me than my talent for absorbing 
positive knowledge." Instilling these features into 
young minds creates safeguards so that our teaching 
does not become a dead-end; it also ensures that we 
will keep alive the wonder of science. 

CASE Summer Science Institute 

Every summer for the past six years teachers from 
Washington, D.C., public schools have participat- 
ed in a CASE experiment: for six weeks we 
immerse them in a program, similar to the one 
used in First Light, of doing science. This experi- 
ment will tell us whether our approach to teaching 
science by doing science can change the way the 
subject is taught in the city's elementary school 
classrooms. The ultimate goal is for the D.C. stu- 
dents to learn to ask good scientific questions, 
investigate them, collect and analyze data, and 
present their results. 

We have observed that children, both in First 
Light and in the city's classrooms, love to do sci- 
ence this way. We've seen how learning is sparked 
when they build structures out of straws and paper 
clips or observe the life cycles of butterflies, moths, 
and mealworms. This teaching technique provides 
the students with a variety of learning strategies 
and the means to show what they have absorbed. 
Their observations give them something to write 
about and a reason to read. Conducting measure- 
ments, integral to collecting and presenting data, 
also affords students an opportunity to use mathe- 
matics. The important skill of logical reasoning is 
strengthened because it is inherent in scientific 
investigation. Alva Abdussaalam, a CASE teacher 
at the special education center, Prospect Learning 
Center, says of our method, "It works!" She main- 
tains that this way of teaching science allows her 
students to learn. 

Sue White, the CASE mathematics coordinator, 
frequently observes that there are children who 
learn differently from other children. These stu- 
dents usually struggle in school and often fail aca- 
demically because the teaching methods are not 
geared to the way their minds work. The kinds of 




science activities that we have developed at CASE, 
and the teaching strategies that accompany them, 
do not rely exclusively on verbal and writing abili- 
ties for the expression of ideas. Perhaps these 
methods can be used to assess the learning poten- 
tials of these students and help them learn in a 
new way. 

CASE Summer Mathematics Institute 

For years, CASE teachers have asked us to run a 
summer institute in mathematics like the one in 
science. This past summer Sue White and Dr. 
Monica Neagoy from Georgetown University did 
just that. A small group of CASE teachers were 
invited to participate. They encountered fractals 
and chaos theory, mathematics concepts new to 
them; learned ways to prepare their students for 
algebraic thinking; and explored mathematical 
tools such as the graphing calculator. As the ses- 
sion progressed, they confirmed our ideas that 
professional development for teachers must be rich 
in content and taught in a variety of ways. These 
teachers also affirmed that our approach to 
strengthening the teaching of science and mathe- 
matics in the elementary classrooms of D.C. pub- 
lic schools is one that can improve the abilities of 
students today and in the future. 

— Chuck James aridities Cifuentes 



CARNEGIE INSTITUTION 



page 26 I YEAR BOOK p8~pp 










Department of Plant Biology 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 2J 



THE DIRECTORS INTRODUCTION 



Q he past year was a time of many changes for the 
department. In June 1999, Olle Bjorkman formally 
retired, more than 30 years after arriving at the 
department for a one-year postdoctoral appoint- 
ment. At a dinner held in his honor, Olle com- 
mented that the Carnegie postdoctoral fellowship 
program had exceeded his expectations and should 
be continued at all costs. It is hard not to agree 
with his sentiments, and during the past five years 
I have made a major effort to redirect endowment 
spending away from departmental services and 
into fellowships. Although this has meant that the 
department provides fewer services, I believe that 
this disadvantage is more than offset by the effects 
of being able to support at least five postdoctoral 
fellows. I fervently hope that some of the fellow- 
ships will support people who have a fraction of 
the influence that Olle has had on plant biology. I 
look forward to seeing what retirement means for 
someone who has remained actively engaged at the 
bench throughout his career. I will note for the 
record that Olle is currently somewhere in the 
mangrove swamps of northern Australia pursuing 
his research interests in mangrove diversity. 

Several other longtime members of the depart- 
ment also took their leave this year. Neil Hoffman 
left to assume a position at Paradigm Genetics in 
North Carolina. Neil is currently managing a bio- 
chemistry group in the company, which is a recent 
start-up focused on exploiting functional genomics 
in Arabidopsis. Brian Welsh, the manager of our 
workshop, retired to Bodega Bay after 13 years at 
the department. Aida Wells retired to explore her 
interests in writing community grants. The main 
building seems eerily quiet, and it remains to be 
seen how anyone will find out what is going on in 




Olle Bjorkman at his retirement party 



the department without her. Finally, I regret to say 
that Rudy Warren, our grounds manager, died 
unexpectedly. 

Because of the staff changes during the past several 
years, the department currently has fewer Staff 
Members than is desirable. Therefore, during the 
coming year we will begin making new appoint- 
ments. In anticipation of these changes, the presi- 
dent and the trustees provided about $2.8 million 
during the year for renovations to several of the 
buildings. The "main lab," where Art Grossman 
and Neil Hoffman were most recently housed, was 
completely renovated and expanded. This building 
now provides laboratory space for the groups 
headed by Shauna Somerville, Art Grossman, and 
me. A new building was erected on the northwest 
side of the lot and now houses the shop, storage, 
and growth chambers. The "400 building," which 
used to house the shop, was converted to modern 



Left: The apex of the female reproductive structure in an Arabidopsis flower is covered with specialized finger-like cells called stigmatic 
papillae. These cells interact with pollen cells to initiate fertilization of the flower. This three-dimensional image of living stigmatic cells was 
created by expression of jellyfish green fluorescent protein, laser scanning confocal microscopy, and computer imaging techniques. 
(Image courtesy David Ehrhardt.) 



CARNEGIE INSTITUTION 



page 28 I YEAR BOOK p8~pp 




o 



Renovation of the main laboratory does not mean work 
stops at the department. 



lab space. In all, the amount of useful lab space has 
been substantially improved and expanded. 

One of the first consequences of the expanded 
space was that it became feasible to consider 
undertaking projects that require reasonably large 
groups of people. In collaboration with Pam 
Green and colleagues at Michigan State, Mike 
Sussman and colleagues at the University of 
Wisconsin, and Steve Dellaporta at Yale 
University, Shauna has established a laboratory 
devoted to producing DNA microarrays for use 
within the department and in the community at 
large. Their group was awarded almost $9 million 
for this and other aspects of the project from the 
National Science Foundation (NSF). The goal is 
to make DNA microarrays containing at least 
12,000 Arabidopsis genes. The arrays can be used 
to measure the expression of each of the 12,000 
genes in response to a wide variety of environmen- 
tal and developmental conditions. It is hoped that 
this approach will facilitate the identification of 



genes that participate in various cellular processes 
and provide fresh insights into how the expression 
of different pathways is coordinated. 

Arthur Grossman and a group of collaborators 
have also begun applying genomics methods to the 
alga Chlamydomonas reinhardtii. They received 
$3.3 million from NSF to develop a number of 
broadly useful genetic tools for the research com- 
munity. These will include production of 
sequenced cDNA libraries, the development of 
DNA arrays, and the production of a high-density 
genetic map of cloned polymorphic DNA frag- 
ments. In conjunction with the powerful genetic 
methods now available for this organism, these 
genomics tools should greatly facilitate the analysis 
of plant gene function in Chlamydomonas. 

More recently, we received more than $5 million 
from the NSF to develop a new database for infor- 
mation about Arabidopsis. The project, called 
TAIR (The Arabidopsis thaliana Information 
Resource) is a collaboration between Carnegie and 
the National Center for Genomic Resources 
(NCGR) in Santa Fe. NCGR is responsible for 
developing software and computer applications, 
and we are responsible for designing the informa- 
tion content of the database and, ultimately, for 
entering the data. Former Carnegie student Sue 
Rhee has returned to the department to lead the 
project; the Web page that describes TAIR is 
located at http://arabidopsis.org. Former postdoc- 
toral associate Eva Huala has also returned to par- 
ticipate in the TAIR project as lead curator. In 
view of the fact that the Arabidopsis genome will 
be completely sequenced by the fall of the year 
2000, 1 am certain that the TAIR project will pro- 
vide an essential new resource to the scientific 
community. My expectation is that the TAIR 
group will also discover completely novel biologi- 
cal insights that can only be derived by having 
access to complete genome sequences and 
advanced computing tools. 

The departmental Staff Members summarize some 
of the research highlights of the past year in the 
following short essays. 

— Christopher Somerville 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 2p 



Olle Bibrkmans Care 



This year marks a major change at the Department 
of Plant Biology: Olle Bjorkman retired. Born in 
Sweden, Bjorkman earned the equivalent of the 
Ph.D. in genetics at the University of Uppsala in 
1 960. At the Carnegie Institution, with which he has 
been associated since 1 964, he has worked with 
other Staff Members and an illustrious string of visi- 
tors. His investigations of physiological and molecu- 
lar mechanisms of photosynthesis and associated 
processes explore how plants adapt to extremes of 
light and temperature and to drought and salinity. 
Bjorkman has been a central figure in the develop- 
ment of environmental plant biology for nearly four 
decades. Over his career, he has received many hon- 
ors in recognition of his research and public service 
contributions. He is a member of the U.S. National 
Academy of Sciences, a fellow of the American 
Academy of Arts and Sciences, and a foreign mem- 
ber of the Australian Academy of Science. He has 
received the Linnaeus Prize, awarded by the Royal 
Swedish Physiographic Society, the Stephen Hales 
Award of the American Society of Plant 
Physiologists, and the Selby Award of the Australian 
Academy of Science. These honors only begin to 
reflect the esteem the scientific community has for 
Bjorkman and his work. 

At the time that Bjorkman joined the department, the 
experimental taxonomy group of Jens Clausen, 
Malcolm Nobs and Bill Hiesey was just finishing up on 
an epic series of experiments that demonstrated the 
existence of ecological races, genetically distinct units 
within a species adapted to different habitats. At the 
same time, new technical approaches and new insights 
into the molecular mechanisms of photosynthesis and 
other key physiological processes of plants were 
developing at the department (particularly by fellow 
Staff Member David Fork, also recently retired) and 
elsewhere. Bjorkman seized the moment, producing a 
synthesis of the genetics, ecology, and plant physiolo- 
gy/biochemistry of plant adaptation. This new 
approach, which drew from several disciplines, illumi- 
nated the plant adaptation problem at different levels 
of organization. Under Bjorkman's leadership, 
progress in this new area was spectacular. 




re the physiotogicai properties of plants growing in their 
environments. During these experiments, temperatures 
sd 50°C. One of the native plants examined in this study 
ry high rates of photosynthesis, and these experiments 



[jig<MjKWJ'JEM»J 



(bl 



Bjorkman took advantage of the long-term 
est) funding and the shop facilities at the Carnegie labs 
to develop new equipment, which defined the state- 
of-the-art in environmental plant biology. Together 
with his Stanford University colleague Harold 
Mooney, for instance, he set up a mobile laboratory in 
the early 1 970s. This instrument package was used to 
make sophisticated measurements on plants in their 
native environments. The mobile lab field campaigns 
examined plants native to such contrasting environ- 
ments as Death Valley National Monument in the heat 
of summer and the shaded floor of the coastal red- 
wood forests. These studies demonstrated dramatic 
adaptive characteristics of plants to extremes of tem- 
perature, drought, salinity, and shade. The picture 
above is from July 1 970 and shows the mobile lab at 
work in Death Valley, California. A young Olle 
Bjorkman is shown (following page) at the controls 
inside the mobile lab during an experiment. 

The collaboration with Mooney also initiated a funda- 
mental change in the way the department operated. A 
Stanford University graduate student, Jim Ehleringer 
(now professor and past chairman of the Department 
of Biological Sciences at the University of Utah) con- 
ducted the research for his Ph.D. thesis under 
Bjorkman's direction. Soon many other students fol- 
lowed this path, and worked with Bjorkman and other 
Staff Members. A close integration of the academic 
program of Plant Biology with Stanford's biology 
department was eventually formalized when Winslow 
Briggs became Director in 1 973. Since then, more 
than 30 graduate students have conducted the major 
part of their thesis research at Plant Biology. 



CARNEGIE INSTITUTION 



PAGEJ0 I YEARBOOK p8~pp 



Bjorkman forged other partnerships. During a sab- 
batical jaunt in 1971-1972 to Canberra, Australia, he 
opened the way for many collaborative studies 
between members of Plant Biology and Australian 
scientists at the Australian National University and 
the CSIRO in the ensuing years. This came to be 
known as the "Carnegie-Canberra connection." It is 
significant that nearly half the participants in a recent 
symposium honoring Bjorkman's retirement came 
from the continent down under. 

Throughout his career, Bjorkman mentored many 
students, postdoctoral fellows, and sabbatical visitors. 
He is legendary for the attention he showered on the 
members of his research team. A consummate bench 
scientist, he never had a large research group. 
Rather, he worked most happily with small groups — 
often only one or two individuals. These research 
"adventures" were highly orchestrated and extended 
far beyond the normal scientific collaboration. It 
could also be said that Olle's co-workers experi- 
enced some of the best meals and drank some of the 
best wines of their lives in the Bjorkman home. 

Olle's career is punctuated with many research mile- 
stones. In the late 1 960s, he began a series of com- 
parative studies of closely related plants genetically 
adapted to contrasting shaded and sunny habitats. His 
studies showed that these plants possessed suites of 
biochemical and morphological adaptations that pre- 
pared them to function more efficiently in their 
respective native environments. In the course of this 
research he discovered that a single factor, the quan- 
tity of an enzyme RuBP carboxylase, determines the 
rate of photosynthesis at high irradiance. He also 
discovered and characterized photorespiration, C 4 
photosynthesis, and photoinhibition, processes that 
have figured prominently in the rapid expansion 
of research on plant adaptation and physiological 
ecology. Collaborators who participated in making 
these advances include fellow Staff Members and 
visitors, Barry Osmond, Jan Anderson, Merv Ludlow, 
John Boynton, Bob Pearcy, and Eckard Ghaul. 

In the mid 1970s, Bjorkman and Mooney initiated 
work that examined the potential range of thermal 
adaptation among higher plants and characterized 
the biochemical mechanisms that plants use to 
modify their thermal limits. Prominent participants in 
these studies include Paul Armond, Murray Badger, 
Merv Ludlow, Norio Murata, Gunnar Oquist, John 
Troughton and CIW technican Frank Nicholson. 




At his retirement symposium Bjorkman, Chris 
Niyogi, and Arthur Grossman presented another 
landmark achievement. His team used powerful new 
genetic approaches with the model organisms 
Chlamydomonas reinhardtii and Arabidopsis thaliana to 
establish that certain carotenoid pigments play an 
essential role in reversibly modifying the properties 
of photosynthetic reaction centers exposed to exces- 
sive light. The genetic elucidation of this mechanism 
was certainly the highlight of the symposium and, 
indeed, is one of the key findings in environmental 
plant biology of this decade. Bjorkman and collabora- 
tors Barry Osmond, Barbara Demmig, Steve Powles, 
Christain Schaefer, Crista Chrichley, Catharina 
Lindley, and longtime technician Connie Chu played 
key roles in characterizing this mechanism that plants 
use to cope with the stress of too much light. 

Many of Bjorkman's former research collaborators 
attended the symposium held in his honor at a hill- 
top retreat in the Napa Valley region of northern 
California. Good food, good wines, and intensive sci- 
entific discussion were in abundance. Several former 
collaborators expressed the sentiment that they did 
the best work of their careers and felt the most 
important during their time of working with Olle. 
The symposium also offered an opportunity to 
reflect on the tremendous creativity and rapid 
progress associated with the early years of 
Bjorkman's career. Factors such as fortuitous timing, 
the audacity of youth, the availability of long-term 
stable funding, and a generous fellowship program 
certainly contributed to his dramatic success. But 
at the core, it was Bjorkman's intellect, curiosity, 
and intensity that led to breakthrough after 
breakthrough. 




CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 3 1 



Joseph Berry 

Understanding the Global Carbon 

Budget 

The year-to-year increase in the C0 2 concentra- 
tion of the atmosphere is largely driven by 
combustion of fossil fuels and deforestation. 
However, natural processes such as exchange of 
C0 2 with the ocean, growth of plants (driven by 
photosynthesis), respiration of living organisms, 
and decomposition also play a key role. These 
processes, which constitute the Earth's carbon 
cycle, account for about 95% of the total exchange 
of C0 2 with the atmosphere. In preindustrial 
times, the global carbon cycle was balanced and 
the C0 2 concentration of the atmosphere was sta- 
ble. At present, approximately two-thirds of the 
C0 2 added to the atmosphere by human activities 
is sequestered by these natural processes — presum- 
ably as bicarbonate in the ocean, wood in the 
forests, and organic matter in the soil. The 
remaining one-third accumulates in the atmos- 
phere, perturbing the radiative properties of the 
atmosphere and possibly altering the climate. C0 2 
sequestration by the global carbon cycle is, there- 
fore, a major factor mitigating the potential impact 
of human activity on climate. The future course of 
anthropogenic climate change depends in no small 
part on how these natural components of the 
Earth's carbon cycle respond in the future. A great 
deal of effort is now focused on understanding 
where the carbon is going and in establishing a 
system that will permit us to monitor the dynamics 
of carbon cycling by the oceans and terrestrial 
ecosystems of the world. 

The most powerful approach developed to date is 
based on a "top-down" analysis of the dynamics of 
C0 2 and other tracers in the atmosphere. Flask 
samples of air are collected at frequent intervals at 
stations located around the globe and sent to cen- 
tral laboratories operated by NOAA, Scripps 
Institution of Oceanography, and CSIRO. 
Analyses of these samples, for 2 and C0 2 con- 
centrations and other trace gases, provide impor- 
tant constraints on inversion calculations that 
attempt to determine the net uptake or release of 
C0 2 from surface reservoirs and to locate these 




Joe Berry (right) in the field. 



sources and sinks. One of the key measurements is 
the C and O isotopes of C0 2 . Great care is 
taken in the measurement protocols used to ana- 
lyze the flasks so that the isotopic measurements 
are of the highest possible accuracy and to provide 
standards so that measurements conducted at dif- 
ferent times or in different labs are comparable. 
However, these methods require large samples of 
air (typically 2 liters), and the measurements are 
labor intensive. 

It is widely recognized that these global measure- 
ments need to be supplemented by process-level 
studies of isotopic effects at the regional, ecosys- 
tem and plant scales. Such data is needed to cali- 
brate and test the models of isotopic fractionation 
used to interpret the global observations. Work at 
these scales needs to be conducted with a precision 
similar to that of the global-scale networks; even a 
modest level of experimentation could easily gen- 
erate as many samples as are now processed by the 
global sampling programs. While the managers of 
these global programs are sympathetic to the need 
for local-scale measurements, they simply do not 
have the capacity to fill this need. Ecosystem sci- 
entists have been reluctant to make the large com- 
mitments of laboratory space, equipment, and per- 
sonnel to duplicate these facilities. 



o 



CARNEGIE INSTITUTION 



page 32 I YEAR BOOK p8~pp 



\® © 




GC/MS 



Fig. I . A two-position-six port Valco valve ( I ) is used to 
switch the connections between a "trapping state," with the 
capillary connecting the sample or standard flask to the vacu- 
um chamber, and a "C0 2 release state," with the helium flow 
directed through the trapping capillary and on the mass spec- 
trometer. An air-actuated plunger (5) is used to submerge or 
withdraw the trapping capillary in a liquid nitrogen dewar. 

With the six-port valve in the trapping state, air is permitted 
to bleed through the trap and into the vacuum chamber. 
During this time the valve diverts the flow of helium directly 
to the mass spectrometer. Pneumatically activated 
microvalves (2) provide on/off control on the flow of air from 
either the sample or the standard flasks. The quantity of air 
sampled is measured manometrically with a high-precision 
capacitance manometer (0-100 mbar). Once a preselected 
quantity of air is admitted, the inlet valve is closed, the pres- 
sure is measured, and the residual air in the system is 
pumped away. The six-port valve is then switched to the 
release state. The trap is withdrawn from the dewar, and a 
microswitch is tripped, permitting a current to flow through 
the stainless steel capillary. This current heats the capillary to 
about 80°C, quickly volatilizing all of the C0 2 and water that 
had been trapped. A nafion drier (7) downstream of the trap 
removes the water and a capillary gas chromatography col- 
umn separates the C0 2 from the N 2 before the gas reaches 
the mass spectrometer. By alternately sampling air from the 
sample flask and one containing a standard, both the C0 2 
concentration and the isotope ratio of the sample can be 
referenced to other measurements. The C0 2 concentration 
is determined to a precision of 0.5 ppm and the isotope 
ratios are determined to a precision of 0.05 parts per mille. 

All of the valves can be computer controlled, permitting the 
process to be automated. Each cycle of trapping and release 
typically takes about four minutes. A typical measurement 
sequence consists of 10 cycles, 5 each of the sample and a 
flask containing a standard air. A multiposition valve (not 
shown) can be used to permit analysis of several sample flasks 
overnight. 



This report describes a new technology for mea- 
surements of C0 2 concentration and isotopic com- 
position of C0 2 in air samples. This technology is 
specifically intended for ecosystem and plant or 
leaf-scale measurements. Significantly, the tech- 
nology uses very small samples of air (less than 5 
ml for a complete analysis) while achieving levels 
of accuracy and cross-calibration that approach 
those of the flask networks. Most important, the 
procedure can be automated. In this new method, 
the batch inlet system of a conventional isotope 
ratio mass spectrometer is replaced with a continu- 
ous flowing helium inlet system. Samples are 
introduced as plugs in the flow of helium, and the 
isotope ratio is calculated from measurement of 
the "peaks" at m/e 44, 45, and 46 that are recorded 
when a sample of C0 2 passes through the mass 
spectrometer source. Typically, the quantity of the 
sample required for a measurement with the flow- 
ing helium inlet is about 10 5 that required for a 
measurement with a batch inlet system. The sys- 
tem described here functions to isolate the C0 2 
from a given quantity of air and to release that 
C0 2 into a stream of helium that carries the sam- 
ple into the mass spectrometer. Additionally, by 
measuring the amount of air used and the size of 
the C0 2 peak, one can calculate the C0 2 con- 
centration in a sample. 

A schematic diagram of the system is shown in 
Fig. 1. Air containing C0 2 is withdrawn from a 
flask and flows into an evacuated volume through 
a capillary tube immersed in liquid nitrogen. C0 2 
is quantitatively trapped from the air, and it is 
rapidly released when the trap is withdrawn from 
the liquid nitrogen. 

Winslow R. Briggs 

Identification and Characterization of 
the Photoreceptor for Phototropism in 
Higher Plants 

Briggs and collaborators previously demonstrated 
that the protein encoded by the NPH1 gene in 
Arabidopsis was a classic serine/threonine kinase, 
and that blue light activated its autophosphoryla- 
tion both in vivo and in vitro. Physiological studies 
and studies with mutants at the nphl locus conclu- 



I 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 




Director Emeritus Winslow Briggs 



sively demonstrated that the nphl protein was 
essential for all of the photo tropic responses 
known in Arabidopsis, including the negative pho- 
totropism of the roots. The researchers did not 
know, however, whether the protein was also the 
photoreceptor for the light-activated phosphoryla- 
tion and hence the photoreceptor for phototro- 
pism,- or whether it was activated by a separate 
photoreceptor. The answer came when postdoc- 
toral associate John Christie successfully expressed 
the NPH1 gene in an insect cell/virus system. His 
experiment showed that if the insect cells were 
kept in the dark while they were expressing the 
gene and the proteins were subsequently isolated 
under a dim red safelight, the recombinant protein 
retained its photosensitivity. Not only did blue 
light activate its phosphorylation, but the time 
course for phosphorylation and the fluence depen- 
dence were both virtually identical to those of the 
native protein. Since no other plant protein was 
present in the preparation, and since insect cells 
expressing the protein accumulated large quanti- 
ties of flavin mononucleotide (FMN), the 
researchers concluded that Nphl was indeed its 
own photoreceptor, and that its light-sensing 
chromophore was FMN. The absorption spectrum 
for the chromoprotein was virtually identical to the 
action spectrum for phototropism, leading the sci- 
entists to conclude that they had finally begun to 
characterize the photoreceptor for phototropism. 
The collaborators named the protein phototropin. 



An interesting characteristic of phototropin is that 
it has two domains, each about 40% identical to 
the other, which are also found in a wide range of 
proteins involved in signaling. These proteins all 
respond to either Light, Oxygen, or Voltage, so 
the scientists designated the regions of amino acid 
similarity LOV domains. The proteins bearing 
LOV domains have been reported in organisms 
ranging from the most primitive bacteria through 
mammals. Two that have been characterized at the 
protein level are both known to be flavoproteins. 
Since the only element that these proteins shared 
with Nphl was a LOV domain, the scientists 
hypothesized that the LOV domains might be the 
specific sites that bound FMN. It was possible to 
express either single LOV domains or a construct 
encoding both LOV domains in Escherichia coli 
and purify the recombinant polypeptide nearly to 
homogeneity. The products were water soluble 
and bound FMN stoichiometrically: constructs 
expressing a single LOV domain showed a 
FMN:protein ratio of 1.0, while those expressing 
constructs with two LOV domains showed a ratio 
near 2.0. Phototropin, therefore, proved to be a 
dual chromophore photoreceptor. 

Recently, the researchers found that LOV 
domains undergo photobleaching that is fully 
reversible in subsequent darkness. The spectral 
change is consistent with the formation of a 
covalent bond between the sulfur of a cysteine 
and one of the carbons of the FMN. Indeed, when 
the only cysteine in one of the LOV domains is 
mutated to a serine, the absorption spectrum of 
the FMN/polypeptide construct is the same as in 
the wild-type spectrum. This indicates normal 
FMN binding, except that the photobleaching is 
entirely eliminated. Other optical studies indicate 
a fairly major protein conformational change in 
one of the FMN/polypeptide constructs with blue- 
light irradiation — a change that is also eliminated 
when the cysteine is mutated to a serine. 

In a related project involving contributions by 
Margaret Olney, John Christie, Gerard Laceve, 
Juliette Leymarie, and Alain Vavasseur, the scien- 
tists obtained evidence that Arabidopsis contains at 
least four blue-light receptors. Several of these 
photoreceptors have been described for higher 



CARNEGIE INSTITUTION 



page 34 I YEAR BOOK 98—99 



plants in the past few years, and in a couple of 
cases, hypothesized to play a role in phototropism. 
These include cryptochromes 1 and 2 and a system 
utilizing zeaxanthin as its chromophore. The 
researchers obtained null mutants for the two 
cryptochromes and a mutant unable to synthesize 
zeaxanthin, and tested their phototropic sensitivity 
and their capacity to undergo blue-light-induced 
autophosphorylation of phototropin. In all cases, 
including cryptochrome 1-cryptochrome 2 double 
mutants, phototropism was normal, as was light- 
activated phosphorylation. The collaborators con- 
cluded that none of the photoreceptor systems 
could play a direct role in detecting the direction 
of unilateral light and mediating the consequent 
development of phototropic curvature. The zeax- 
anthin mutant was known to lack the normal blue- 
light-induced opening of its stomata, and the 
researchers tested both the two cryptochrome 
mutants and a phototropin null mutant for stom- 
atal opening to determine whether any of these 
photoreceptors played a role in the stomatal 
response. In all three cases, the blue-light-induced 
stomatal opening was normal. These results indi- 
cate that Arabidopsis has a minimum of four blue- 
light photoreceptors: phototropin, the two cryp- 
tochromes, and a photoreceptor mediating blue- 
light-induced stomatal opening. 

David Ehrhardt 

Mechanisms and Roles of Intercellular 

Interactions 

Higher plants are remarkably organized collections 
of individual cells. All multicellular organisms 
share the common problem of how to create 
multicellular diversity and form beginning from a 
single cell. To accomplish this task, the processes 
by which cells divide, grow, and acquire new iden- 
tities and functions must be coordinated with the 
activities and identities of other cells. Short-range 
interactions among cells have been shown to play 
key roles in establishing cellular identity, patterns 
of cell morphogenesis, and multicellular pattern 
formation. However, little is known about the 
machinery by which plant cells perform these 
interactions, how this machinery is assembled and 
regulated, and how cell-cell interaction affects sub- 



cellular organization and morphogenesis. 
Researchers in the Ehrhardt lab are pursuing the 
problem of cell-cell interaction and its role in cel- 
lular and multicellular development in the model 
plant Arabidopsis thaliana. The scientists are taking 
a multidisciplinary approach — including genetics, 
protein engineering, and confocal microscopy — 
with an emphasis on observation and manipulation 
of live cells and their components. 

The ability to introduce the jellyfish green fluores- 
cent protein (GFP) into cells of other organisms as 
an expressed genetic sequence is enabling new 
experimental approaches to cell and developmental 
biology. The Ehrhardt lab is exploiting GFP to 
create new tools for visualization of plant cell 
structure and behavior, and to identify genes of 
functional interest. For example, many proteins 
that are involved in cell-cell and cell-wall interac- 
tion are expected to localize to the cell periphery, 
or to domains about the cell periphery. Use of 
GFP, combined with the ease with which 
Arabidopsis can be transformed, has made it possi- 
ble for the researchers to design and conduct large- 
scale screens for genetic information that confers 
specific subcellular localization properties. In a 
collaborative project with Sean Cutler, a 
GFP::cDNA fusion library was created and trans- 
formed en mass into Arabidopsis. Individual trans- 
genic seedlings were screened for GFP localization 
patterns with confocal microscopy. This screen 
identified a large number of genetic tags that con- 
fer distinct subcellular localization patterns to 
GFP. Among the variety of tags that were recov- 
ered is a marker that localizes to the cell periphery 
and accumulates in discrete foci at cell-cell contact 
sites, structures that are likely to be the cell-cell 
channels known as plasmodesmata. 

Plasmodesmata are the only points where most 
plant cells come into direct contact with each 
other without an intervening cell wall, and are 
hypothesized to play important roles in cell-cell 
interaction, including the possible exchange of 
informational macromolecules involved in devel- 
opment. Very little is known about the compo- 
nents that make up plasmodesmata, the genes that 
encode the components, how the plasmodesmata 
are assembled at particular cell junctions, or how 



CARNEGIE INSTITUTION 



YEAR BOOK pS—pp page 55 



communication through them may be regulated. 
The researchers hope to exploit the new GFP tag 
as an entry point to pursue these questions. 

Confocal imaging of GFP is proving to be a robust 
method for visualizing cell behavior, including 
behavior related to morphogenesis. The group is 
employing their collection of GFP markers to study 
the mechanism of cytokinesis in Arabidopsis shoot 
cells. Plant cells divide very differently from animal 
cells. A new cell partition, a phragmoplast, is initi- 
ated as an internally assembled structure before it is 
fused to the parental cell membrane. It is during 
phragmoplast development that some plasmodes- 
mal channels are initiated. Confocal imaging of 
GFP is opening a new window on cell division by 
giving researchers the ability to visualize three- 
dimensional aspects of cytokinesis as it occurs in liv- 
ing cells. This technique provides access to cells that 
were previously difficult to observe, such as those in 
the shoot epidermis and cortex, permitting the 
researchers to address questions about how these 
cells perform cytokinesis in their native multicellular 
context. In addition, the variety of GFP markers 
that the group has isolated allows them to extend 
questions about cytokinensis to the behavior of dis- 
crete organelles and cell compartments. 

Important patterns of cell-cell interaction are 
established during embryogenesis. However, the 
Arabidopsis embryo has been challenging to study 
as a living system. Using their GFP tools, the 
Ehrhardt group is developing methods to image 
live embryos. The methods have allowed the 
researchers to obtain three-dimensional images of 
the entire cellular structure of live early embryos. 
These techniques will expand and make it possible 
to define in new ways the cellular phenotypes of 
mutations that affect the development of the 
embryo and possible plasmodesmal mutants that 
they hope to acquire with use of the GFP marker. 

A greater understanding of plant development will 
give biologists insight into the diverse mechanisms 
that have evolved to solve the problem of multi- 
cellular life. This information may one day help 
scientists engineer crop plants that make more 
efficient use of limited resources and are better 
optimized to produce food and novel products. 




c 



. 



Fig. 2. A variety of subcellular markers are isolated by screen- 
ing an expression library of GFP::cDNA fusion proteins in 
Arabidopsis. (A) A fusion to the carboxy terminus of CRY2 
accumulates in the cell nucleus and is associated with con- 
densed chromosomes during mitosis. Shown is a single confo- 
cal section of a root cell in anaphase of mitosis, surrounded 
by cells that are in interphase. CRY2 is a blue-light photore- 
ceptor that affects a variety of plant developmental responses 
to light. (B) The library screening method is capable of yield- 
ing surprises. This panel shows a computer reconstruction of 
hypocotyl cells expressing a fusion to a novel protein. This 
protein accumulates on the surface of an organelle that 
remains to be positively identified. (C) This is a computer 
reconstruction of young leaf epidermis. These cells express a 
fusion protein that localizes to the plasma membrane. Imaging 
of plasma membrane markers allows clear visualization of 
epidermal cell pattern. A mature pair of guard cells forming a 
stomate is shown in the upper left. Cell division patterns 
leading to stomatal development are clearly visualized visible 
throughout the image. 



Chris Field 

Simulating Global Climate Change 

In 1998 the Field lab, in collaboration with 
Harold Mooney and his group at Stanford, 
launched a major new global change study, 
designed to look at four of the main ways the 
global environment is changing. The study is a 
manipulative experiment in which grassland 
ecosystems are exposed to four different compo- 
nents of global change: elevated C0 2 , warming, 
increased water inputs, and nitrogen deposition. 
The treatments include two levels of each of the 
factors (enhanced versus ambient) and all possible 
combinations of the four factors, for a total of 16 
treatments. 

Three main questions motivate the design. First, the 
scientists want to know when effects of global 
change factors are additive. This is important 
because most experiments address the global change 
factors individually, and there is a risk of misinter- 
pretation if the factors interact in unexpected ways. 
Second, they are asking how much of the ecosystem 
response comes from changes in the composition of 
the community of plants, microbes, and animals in 



CARNEGIE INSTITUTION 



PAGE 36 I YEAR BOOK p8~pp 



the plots, versus changes in the physiology, bio- 
chemistry, and morphology of species present at the 
beginning of the experiment. Most experiments run 
for a time period that is shorter than the longevity of 
the dominant plants, and therefore have limited 
access to the components of the response driven 
through changes in species composition. Third, the 
researchers want to identify the pathways through 
which each of the global change factors affects pri- 
mary production, carbon storage, nutrient dynamics, 
the water budget, and species composition. One of 
the most interesting aspects of global change effects 
on ecosystems is that the responses are rarely direct. 
It is not uncommon for an ecosystem response of 
interest to be separated from the direct response by 
three or even more layers of indirect responses. 

The experiments are located on Stanford University's 
Jasper Ridge Biological Preserve, in an area 
dominated by annual grasses. The treated plots are 
relatively small, but the small size and high density 
of the plants means that even a plot of 0.8 m 2 has 
several thousand individuals of the dominant 
species — certainly enough to qualify as a whole 
ecosystem. Because the researchers placed a 
priority on keeping the conditions as natural as 
possible, they are using chamberless methods to 
apply all of the treatments. The warming is from 
overhead infrared lamps (designed to warm 
chicks), and the C0 2 is released as a cloud over 
each treatment plot. The C0 2 release rate is 
controlled by a computer to rise and fall with 
the wind speed, keeping the concentration 
(approximately twice that in the current atmos- 
phere) over each plot relatively constant. 

The treatments with added water and added nitro- 
gen fertilizer do double duty in this experiment. 
First, they mimic important global changes: many 
of the world's ecosystems are already heavily 
impacted by nitrogen deposition, and climate mod- 
els almost universally predict that precipitation 
increases in parallel with temperature. Second, the 
water and nitrogen treatments provide probes for 
untangling the direct and indirect effects of the C0 2 
and warming treatments. For example, C0 2 can 
increase plant growth directly by increasing photo- 
synthesis, but it can also act indirectly by decreasing 
stomatal conductance and increasing soil moisture. 



Similarly, warming can accelerate the decomposi- 
tion of soil organic matter through metabolic stim- 
ulation of the soil microorganisms; it can also have 
the opposite effect by drying the soil. 

The experiment is a useful approach to studying 
global change because the changes really are occur- 
ring in combination and over a long enough period 
to encompass several generations of many species. 
Some aspects of a deliberate manipulation are 
always unnatural (for example, the sudden imposi- 
tion of the experimental treatments). But careful 
assessment with models can help isolate the non- 
natural effects of the treatments. By examining a 
broad range of processes in an ecosystem with sub- 
stantial functional diversity, the scientists hope to 
uncover general principles that will help predict 
global change responses in all ecosystems. 

The first growing season with the experiment 
operating is now complete. The preliminary analy- 
sis points to some patterns that the researchers 
expected and some they did not. Among the 
expected responses was the earlier flowering of 
grasses in the heated treatments. However, the 
grasses grew the largest in the treatments with 
both added water and added nutrients. Elevated 
C0 2 had one potentially important unexpected 
response — it enhanced the success of shrub 
seedlings, suggesting that it could play a role in 
transforming the grassland to shrubland. So far, 
most of the significant responses are in the one- 
factor and two-factor treatments, rather than in 
those with three or four factors. 

A number of recent studies with simulation mod- 
els highlight the difficulty of interpreting long- 
term ecosystem responses from short-term experi- 
ments. To provide enhanced resolution on the 
dynamics of the processes with long time con- 
stants, the scientists are using 13 C, 14 C, and 15 N 
to trace the movement of carbon and nitrogen 
into pools of soil organic matter with a range of 
turnover times. The most valuable insights on the 
long-term dynamics of species composition, carbon 
storage, and other processes will come from the 
combination of the tracer analysis and several years 
of experimental treatments. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 57 



Arthur R. Grossman 

Regulation of Phosphorus Limitation 

Responses in Chlamydomonas 

Agricultural soils typically contain suboptimal lev- 
els of phosphate (Pi). Consequently, Pi is an 
important component of supplementary fertilizers. 
Usually some of this supplementary Pi is lost from 
agricultural fields as runoff into nearby lakes and 
rivers, which can lead to algal blooms, eutrophica- 
tion of aquatic ecosystems, and fish kills. The sus- 
tainability of agricultural yields and the quality of 
aquatic ecosystems depend on more efficient 
acquisition and use of Pi by crop plants. Efficient 
Pi utilization by plants will also decrease our 
dependence on rock phosphate reserves, a com- 
modity that is often mined with negative econom- 
ic and ecological consequences. 

Researchers in Grossman's lab are interested in 
understanding the mechanisms that regulate phos- 
phate metabolism in plants. Some of their recent 
work has focused on phosphorus starvation respons- 
es. In-several organisms, phosphorus starvation 
responses include the induction of proteins that 
allow the cells to acquire Pi more efficiently (such as 
alkaline phosphatases with broad substrate specifici- 
ties and high-affinity Pi transporters) and the slow- 
ing, or cessation, of cell division. A two-component 
regulatory system (PhoB and PhoR) governs 
responses of Escherichia coli to phosphorus limita- 
tion. In Saccharomyces cerevisiae, phosphorus starva- 
tion responses are controlled by a cyclin-dependent 
kinase (Pho80-85) complex. Wykoff, Usuda, 
Shimogawara, and Grossman recently character- 
ized phosphorus starvation responses in the unicel- 
lular green alga Chlamydomonas reinhardtii and 
screened for mutants that were unable to accumu- 
late extracellular alkaline phosphatase in response to 
phosphorus limitation. One of the mutants 
obtained, designated psrl (phosphate starvation 
response), is unable to induce specific responses to 
phosphorus starvation, including the accumulation 
of high-affinity Pi uptake and the secretion of alka- 
line phosphatases. Further characterization of the 
mutant demonstrated that although wild-type cells 
continue to divide three to four times upon the 
imposition of phosphorus starvation, the psrl 
mutant stopped dividing almost immediately. The 



mutant appears to be unable to access external 
and/or internal reserves of Pi and consequently is 
unable to continue dividing. Wykoff and collabora- 
tors cloned the PSR1 locus to better understand 
how phosphorus starvation is regulated and to 
determine the relationships among regulatory sys- 
tems that govern Pi metabolism in photosynthetic 
and nonphotosynthetic eukaryotes. 

The Psrl gene encodes a protein of 762 amino 
acids. Although the entire length of the protein is 
not similar to polypeptides represented in the 
database, the protein does contain numerous small 
regions that resemble specific domains of tran- 
scription factors. Most striking is a 59 amino acid 
region (amino acids 187 to 245) that is similar to a 
domain of Ccal, a transcription factor in 
Arabidopsis that regulates light-harvesting genes in 
response to circadian rhythm. This region is 
required to bind Ccal to DNA in a sequence-spe- 
cific manner and is postulated to be a distantly 
related myb DNA binding domain. Myb domains 
have been shown to mediate various types of tran- 
scription, and thus, Psrl could be a transcriptional 
regulator. Arabidopsis also contains a second gene 
(represented in the EST database) encoding a pro- 
tein with strong similarity to Psrl in the "myb- 
like" domain. Psrl also has three glutamine-rich 
tracts; these regions are present in certain tran- 
scription factors and appear to be involved in the 
activation of gene expression. Another feature of 
Psrl is a serine/threonine-rich region and a possi- 
ble metal-binding site. 

To monitor the level of Psrl and determine its sub- 
cellular location, a hemagglutinin (HA) peptide 
epitope tag was incorporated into the protein. 
Strains harboring the epitope-tagged Psrl were 
stained with a red fluorescent dye specific for DNA 
and a green fluorescent immunochemical staining 
system, which allows the tagged Psrl protein to be 
visualized. The stained cells were viewed by confo- 
cal microscopy after exposure to various environ- 
mental conditions (Fig. 3). The intense red fluores- 
cence (light gray) defines the nucleus of the cells in 
the image (1). Cells from nutrient-replete cultures 
exhibited a low level of green fluorescence in the 
nucleus with little in the cytoplasm. After 24 hours 
of phosphorus starvation, the nuclei fluoresce 



CARNEGIE INSTITUTION 



page 38 I YEAR BOOK p8~pp 




o 



Fig. 3. This series of images shows the Grossman's lab test for monitoring the Psrl protein's levels and locations within cells. 



bright green (light gray, 2). Overlap of immunolo- 
calized Psrl with the nuclei is represented as yellow 
fluorescence (glowing areas, 3). Together the results 
demonstrate that Psrl is a phosphorus-starvation- 
inducible, nuclear-localized protein. Since approxi- 
mately the same amount of fluorescence is observed 
in the cytoplasm of Chlamydomonas cells, whether 
or not they are starved of Pi, Psrl localization to 
the nucleus is not likely to be the key regulatory 
step in controlling the phosphorus starvation 
responses. Finally, the scientists examined the 
expression of the Psrl transcript during phosphorus 
replete and phosphorus starvation conditions and 
observed that transcript levels increased approxi- 
mately tenfold after 12 hours of starvation; they 
began to decline soon after. 

Psrl regulates only some responses of 
Chlamydomonas to phosphorus starvation. The 
mutant cells still survived prolonged phosphorus 
starvation, and photosynthesis was down-regulated 
during phosphorus deprivation of the psrl mutant. 
These results indicate that other regulatory factors 
influence phosphorus starvation responses. Psrl is 
the first regulator of Pi metabolism identified in a 
plant. Significantly, it has similarity to Arabidopsis 
sequences, suggesting that Pi metabolism may be 
similarly regulated in vascular plants. It is interest- 
ing that Psrl does not resemble any genes in 
Saccharomyces; this raises the possibility that Pi 
metabolism in Chlamydomonas, and possibly vascu- 
lar plants, is regulated in a way that is different 
from that of nonphotosynthetic eukaryotes. 



Furthermore, Psrl is induced during Pi starvation, 
differing from elements involved in controlling Pi 
metabolism in yeast. 

The researchers propose a speculative but plausible 
model for Psrl control of the phosphorus starvation 
responses in Chlamydomonas. The intracellular level 
of Psrl is low at all times, with the majority of pro- 
tein in the nucleus. During phosphorus starvation, 
the nuclear-localized protein is activated by an 
undefined mechanism and binds specific "Pi-sensi- 
tive" promoters. The genes that are activated early 
in the phosphorus starvation responses, such as that 
of the Pi transporter and the Psrl gene itself, may 
have a high affinity for Psrl. As Psrl continues to 
accumulate, the lower- affinity promoters begin to 
bind Psrl; this could explain the lag in phosphatase 
induction relative to Pi transport activity. As the 
cells stop dividing and enter a quiescent phase, the 
transcriptional apparatus operates at a minimal 
level, and many genes, including those involved in 
the initial phases of the cell's responses to phospho- 
rus limitation, become inactive. The group hopes to 
test these possibilities over the next few years. 

Christopher Somervtlle 
Genetic Dissection of Cell Wall 
Structure and Function 

The plant cell wall is a complex structure composed 
of a variety of branched and unbranched high-mol- 
ecular-weight polysaccharides and a variety of struc- 
tural and catalytic proteins. Some cell walls also 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 39 



contain lignin, a very high molecular weight 
polyphenol. Understanding the structure and func- 
tion of plant cell walls is of interest for several rea- 
sons. First, because the wall controls cellular expan- 
sion, it seems likely that morphogenesis involves 
mechanisms that determine the direction and extent 
of wall expansion. Thus, understanding how the 
wall is made and modified may lead to insights into 
how plants control their body plan. Cell walls are 
also the major component of terrestrial biomass and 
are used in large amounts as sources of fiber (e.g., 
paper, cotton, fuel, and feed). Somerville considers 
it likely that if researchers understand the factors 
that regulate wall assembly it will be possible to 
greatly enhance the efficiency for using cell walls 
from agricultural and forestry species. 

Relatively little is known about how cell walls are 
assembled or what the functional significance is of 
the: various components. One reason for the limit- 
ed progress is that it has been difficult to separate 
the components of the wall without altering them 
so that they no longer resemble their in vivo con- 
dition. A second reason is that most of the 
enzymes involved in wall synthesis have proved 
difficult or impossible to purify and characterize. 
Thus, the details of how the wall is made are 
sketchy. There is also no system that permits 
reconstitution of walls from purified components. 
Thus, it is not possible to examine how varying the 
components affects the physical properties of 
reconstituted walls. Indeed, there are numerous 
technical problems associated with the complexity 
of the structure and the high molecular weight and 
aqueous insolubility of the components. 

One project in the Chris Somerville lab is focused 
on using genetics to try to dissect the function of 
the various components and to identify the 
enzymes that participate in wall synthesis. The 
basic idea is that since researchers cannot recon- 
struct walls of differing composition in vitro, it 
should be possible to do this in vivo by altering the 
activity of the genes that encode the various com- 
ponents. Several years ago Simon Turner, then a 
postdoctoral associate, initiated the isolation of a 
series of mutants with altered cell wall composi- 
tion by screening for alterations in morphology of 



the vascular tissues in stem sections (Fig. 4). 
Among other things, the scientists identified four 
mutants (irxl...4) in which xylem cells collapsed 
because of deficiencies in the secondary cell wall. 
More recently, the Somerville lab in collaboration 
with Simon Turner's group at the University of 
Manchester, cloned one of the genes, correspond- 
ing to the irx3 mutation, by map-based cloning. 1 
This gene is closely related to a putative cellulose 
synthase gene cloned from cotton by Debbie 
Delmer and colleagues and is, therefore, thought 
to be a xylem-specific cellulose synthase. The 
analysis suggests that the irxl and irx2 loci may 
define other components of the cellulose synthase 
complex and are, therefore, targets for map-based 
cloning. 

In addition to the use of forward genetics, the 
group is exploring the use of functional genomics 
approaches 2 to try to identify other genes that par- 
ticipate in wall synthesis. The scientists are 
engaged in the analysis of the function of a large 
family of genes in Arabidopsis that show homology 
to cellulose synthase. To date, they have identified 
44 members of this family in the database of pub- 
lic Arabidopsis sequences. The relationship of these 




1 Taylor etal., 1999. 

2 Somerville and Somerville, 1999. 



CARNEGIE INSTITUTION 



page 40 I YEAR BOOK p8~pp 



genes to one another is shown on the Web site at 
http://cellwall.stanford.edu. 

There are six major branches to the family of cel- 
lulose-synthase-like genes called CesA, Csl a, (3, 7, 
5, e. The CesA branch contains irxJ and other 
genes that appear to be cellulose synthases. The 
hypothesis is that the Csl genes represent the pro- 
cessive /3-glycan synthases that make the /3-linked 
polymers other than cellulose (i.e., cellulose is (3- 
1,4-glucose). The researchers are exploring the 
function of the Csl families by making mutations 
in many of the genes, and determining where and 
when they are expressed. They have identified 
insertional mutations in a number of these genes 
and are characterizing the chemical composition 
of the walls from the mutants. However, to date 
they do not have convincing changes in cell wall 
composition in any of the mutants or in anti- 
sense/cosuppression lines for some of the genes. 
Because of the large number of related genes, it 
seems possible that many of the genes have func- 
tional duplicates that mask the effects of mutations 
that inactivate one of the genes. It may be possible 
to overcome this problem by using methods, such 
as antisense or cosuppression, that permit silencing 
of the expression of target genes in transgenic 
plants. Although the analysis of the wall remains 
an unusually difficult problem, Somerville believes 
that the new tools of functional genomics will pro- 
duce some fresh insights during the coming years. 2 

Shauna Somerville 

Mechanisms of Disease Resistance 

Powdery mildew diseases occur on more than 
9,000 plant species, including agriculturally impor- 
tant field and horticultural crops. The powdery 
mildew pathogens are obligate, biotrophic fungal 
pathogens that grow only on living host tissues. 
To successfully colonize a host, biotrophic 
pathogens must strike a balance between drawing 
sufficient nutrients from the host to thrive but not 
so much that the host dies. The powdery mildews 
extract nutrients and water from their hosts via a 
haustorium — a fungal structure encapsulated by an 
invagination of the host plasma membrane. This 
specialized host membrane is the site of nutrient 



transfer to the powdery mildew pathogen. In 
addition, the successful powdery mildew isolates 
must be able to evade or must be tolerant of nor- 
mal host defenses. 

In one of Shauna Somerville's lab projects, post- 
doctoral fellow John Vogel screened more than 
60,000 mutagenized powdery-mildew-susceptible 
plants for resistant mutants. From this screen, two 
classes of mutants were expected. In one class, the 
researchers predicted that the defense responses 
would be successfully activated when normally 
they are not. This class includes both mutants in 
which defense responses are induced following 
powdery mildew infection, and those in which 
defense responses are constitutively activated — or 
turned on all the time. The second class consists of 
mutants with defects in host compatibility fac- 
tors — components required by the pathogen for 
the successful colonization of the host. To aid in 
classifying the mutants into one of these two class- 
es, Vogel assayed the mutants for three features: 
the expression of known defense responses, the 
stage of powdery mildew arrest, and changes in 
susceptibility to other pathogens. Detailed analysis 
of four mutant groups was completed. 

The researchers found that the mutants in the 
largest complementation group are characterized by 
reduced pollen transmission, enhanced accumula- 
tion of pathogenesis-related protein 1 (PR1) 
mRNA, and susceptibility to a closely related pow- 
dery mildew, Erysiphe orontii. Thus, this group may 
fall into the class with enhanced defense responses. 
However, the defenses are not broad spectrum since 
they are effective only against E. cichoracearum. 

Mutants in a second group did not exhibit mor- 
phological aberration, had enhanced accumulation 
of PR1 mRNA, and were resistant to two addi- 
tional biotrophic pathogens, E. orontii and 
Peronospora parasitica — the downy mildew 
pathogen. Surprisingly, these mutants did not pro- 
duce callose either at sites of fungal penetration, a 
common host response, or at wound sites. (Callose 
accumulation in pollen tubes is normal, suggesting 
that these mutants are not defective in callose syn- 
thesis per se.) This mutant group may also fall into 
the class of mutants with enhanced defense 



CA1 



RNEGIE INSTITUTI 



ON 



YEAR BOOK p8~pp page 41 



responses, with the caveat that whatever defense 
responses are induced they do not include the cal- 
lose response. This mutant class is potentially 
interesting for commercial applications since it 
confers resistance on multiple pathogens. 

A third mutant group developed microlesions of 
dead cells in mesophyll tissue. (The powdery 
mildew fungus never penetrates beyond the epi- 
dermal layer.) These microlesions appear to arise 
regardless of the presence of the pathogen, and the 
lesions do not increase in either number or size 
following inoculation with the powdery mildew 
pathogen. Thus, although host-cell death of 
attacked cells — the hypersensitive necrosis 
response — is often associated with the expression 
of resistance, the researchers believe that the spon- 
taneous microlesions observed in this mutant 
group do not play a direct role in disease resis- 
tance. PR1 mRNA accumulation is reduced rela- 
tive to the susceptible wild-type plants, and the 
disease resistance phenotype is expressed only 
under high light conditions where the mutants are 
dwarfed. Under low light conditions, the mutants 
resemble the wild-type parent in stature and dis- 
ease susceptibility. Given this spectrum of proper- 
ties, it is difficult to place the mutants of this 
group in either of the two predicted classes. 



The final mutant group consisted of plants with 
no significant increase in any of the known defense 
responses. This mutant is the best candidate for 
the class in which host compatibility factors have 
been disrupted or a totally novel defense pathway 
has been activated. 

Relatively little is known about which host com- 
ponents contribute to disease development in sus- 
ceptible plants. However, with a better under- 
standing of such factors, it seems possible that dis- 
ease control strategies based on disrupting the suc- 
cessful colonization by the pathogen may offer a 
useful alternative to current strategies based on 
known host resistance genes. For example, a typi- 
cal barley powdery-mildew-resistance gene has a 
useful life span in the field of only five years. 
Disease control strategies based on disrupting host 
compatibility factors may be more difficult for the 
powdery mildew pathogen to overcome in the field 
and thus be more stable. 

In future studies, John Vogel will clone and char- 
acterize the genes from each mutant group. These 
genes will provide necessary tools both to evaluate 
any potentially novel defense pathways or pathway 
regulators uncovered by the mutant screen and to 
evaluate the hypothesis that genes recovered from 
this project encode host compatibility factors. The 
latter genes are potential sources of stable powdery 
mildew resistance. 



CARNEGIE INSTITUTION 



page 42 YEAR BOOK p8~pp 



Department of Plant Biology Personnel 



Research Staff Members 

Joseph A. Berry 

Olle E. Bjorkman, Emeritus' 

Winslow R. Briggs, Director Emeritus 

Christopher B. Field 

Arthur R. Grossman 

Neil E. Hoffman 2 

Christopher R. Somerville, Director 

Shauna G Somerville 

Staff Associate 

David Ehrhardt 

Postdoctoral Fellows and Associates 

Devaki Bhaya, USDA Research Associate 

John Mackie Christie, NSF Research Associate 

Gert jan De Boer, Carnegie Fellow" 

Rob Ewing, NSF Research Associate 

David Finkelstein, NSF Fellow 

Wei Fu, NASA Research Associate 2 

In-Seob Han, NSF Research Associate 15 

Eva Huala, NSF Research Associate"' 

Chung-Soon Im, NSF Research Associate" 

Jorg Kaduk, DOE Research Associate 

David M. Kehoe, NSF Research Associate'* 

Deepak Khatry, NSF Research Associate' 9 

Wolfgang Lukowitz, McClintock Fellow 

Margaret Olney, Carnegie Fellow 1 

Jeong Woo Park, NSF Research Associate 13 

Dana L Parmenter, DOE Research Associate 

Katrina Ramonell, NSF Research Associate 20 

Miguel Ribas-Carbo, Carnegie Research Associate 

Todd Richmond, DOE Research Associate 

Matthias Rillig, Carnegie Research Associate 

Koji Sakamoto, NSF Research Associate 2 ' 

Wolf Ruediger Scheible, DFG Fellow 

Danja Schuenemann, DFG Fellow 22 

John Sedbrook, DOE Research Fellow 23 

Rebecca Shaw, Hollander Fellow 

Norbert Sprenger, Swiss National Science Fellow* 

Susan S. Thayer, NSF Research Associate 

Margaret Torn, Mellon Research Associate 2 * 

Chao-Jung Tu, Carnegie Research Associate 

Lon van Waasbergen, NSF Fellow 

Per Villand, USDA Research Associate 25 

John Vogel, NIH Fellow 

lain Wilson, DOE Research Associate 

Shu-Hsing Wu, NSF Research Associate 22 

Predoctoral Fellows and Associates 

Sean Cutler, Stanford University 
Dafna Elrad, Stanford University 
Vanessa Fens, Wageningen Agricultural University, 

Netherlands 2 ' 1 
Stewart Gillmor, Stanford University 
Claire Granger, Stanford University 
Laura Hoffman, Stanford University 
Geeske Joel, Stanford University 1 
Chris Lund, Stanford University 
Marc Nishimura, Stanford University 



Margaret Olney, Stanford University 21 
Johanna Polsenberg, Stanford University 
Jim Randerson, Stanford University' 
Celine Schiff, National Institute of Agronomy, 

Pans, France' 6 
Patrick Sieber, University ofFribourg 27 
Monica Stein, Stanford University 
Chris Still, Stanford University 
Xin Wang, Stanford University 
Dennis Wykoff, Stanford University 
Erika Zavaleta, Stanford University 26 

Support Staff 

Pinky Amin, Laboratory Technician 
Cesar R Bautista, Horticulturist 
Elena Bolchakova, Laboratory Technician 23 
Kathryn Bump, Administrative Assistant 
Catherine Chase, Laboratory Assistant 30 
Sohaila Dar, Laboratory Assistant 3 ' 
Nadia Dolganov, Research Associate 32 
Beverly Fang, Laboratory Assistant 27 
Melissa Flanigan, Laboratory Assistant 10 
Glenn A. Ford, Laboratory Manager 
Anthony Gallego, Laboratory Assistant 3 ' 
Joel Griffitts, Laboratory Technician 3 
Stephen Gross, Laboratory Technician 
Meredith Johnson, Laboratory Technician 33 
Natalia Kalinina, Laboratory Assistant 3 
Clara Liang, Laboratory Assistant 3 * 
Adam Lowry, Laboratory Technician 2 
Angela Lu, Laboratory Assistant 35 
Barbara March, Bookkeeper 
Eriko Miura, Laboratory Technician 
Barbara Mortimer, Laboratory Technician 
Frank Nicholson, Facilities Manager 
Lisa Onaga, Laboratory Assistant' 
Kalpana Pachipala, Laboratory Assistant 
Patti Poindexter, Laboratory Technician 
Prorseut Por, Laboratory Assistant 3 ' 
Hector Pulido, Maintenance Technician 
Pedro F. Pulido, Maintenance Technician 
Thomas Robertson, Laboratory Assistant 30 
Adnenne Roeder, Laboratory Assistant 36 
Serafima Romanovskaya, Laboratory Assistant 3 
Georgina Salazar, Laboratory Assistant 38 
Delia Santiago, Laboratory Assistant 39 
Connie K. Shih, Senior Laboratory Technician 
Jennifer Silva, Laboratory Assistant* 
Jon Slenk, Computer Programmer 
Mary A. Smith, Business Manager 
Carolyn Stromberg, Laboratory Assistant*' 
Gayathri Swaminath, Laboratory Technician 29 
Donna Sy, Laboratory Assistant* 7 
Mary Varella, Laboratory Assistant* 3 
Jo-Man Wang, Laboratory Technician 
Susana Wang, Laboratory Assistant' 6 
Rudolph Warren, Maintenance Technician** 
Aida E. Wells, Secretary 
Brian M. Welsh, Mechanical Engineer' 
Diana Wiszowaty, Laboratory Assistant* 5 
Ling Zhang, Laboratory Technician* 6 



Visiting Investigators 

Farhah Assaad, University of Munich, Germany 3 
Yoann Huet, University of Munich, Germany 3 
Masahiro Kasahara, University of Tokyo, Japan* 
Michihiko Kobayashi, University of Kyoto, Japan 5 
Gundolf Kohlmaier, University of Frankfurt, Germany 6 
Louise Michaelson, University of Bristol, U.K. 7 
Kosuke Shimogawara, Teikyo University, Japan 6 
Renee Sung, University of California, Berkeley 9 
Daniel Vaulot, Centre National de la Recherche 

Scientifique, Roscoff, France' 
Daniele Werck, CNRS-lnstitute of Plant Molecular 
y, France" 



Carnegie Fellows (Senior) 

In-Seob Han, University of Ulsan, Korea' 
Young Mok Park, Korea Basic Science 
Institute, Korea' 3 



'Retired June 30, 1999 

To June 30, 1999 

'From January 1 , 1 999 

"From September 8, 1 998 

To March 30, 1999 

'From April 1 2, 1 999 

'From Apnl 5, 1 999 

To August 18, 1998 

'From February 1 , 1 999 

'To August 31. 1 998 

"From January 24, 1999 

'To August 15, 1998 

"From July I, 1 998 to December 3 1 , 1998 

Trom July I, 1998 

To August 1 5. 1 998 

To October 3 1 . 1 998 

"From January II, 1999 

'To October 1 5. 1 998 

"From Apnl 15, 1999 

•"From June I, 1999 

Tram May I, 1999 

"To February 28, 1999 

Tram September 1 , 1 998 

"To July 3 1 , 1 998 

To Apnl 9, 1 999 

Trom March 15, 1999 

"To December 3 1 , 1998 

Trom October I, 1998 

•To July 15, 1998 

"To November 30, 1 998 

"To September 30, 1998 

"To Apnl 5, 1999 

"From September 1 , 1 998 to January 3 1 . 1 999 

"To January 31, 1999 

3S FromJune 16, 1999 

"To August 1 . 1 999 

"From May 6, 1999 

"From January 15, 1999 

"From December I, 1 998 to June 30, 1999 

'"From Apnl 23. 1999 to June 30, 1999 

"From October 28, 1998 to February 28, 1999 

"To June 15, 1999 

"From October 28, 1998 

"Deceased May 30, 1999 

,s To February 28, 1999 

"from Apnl 1 , 1 999 



Department of Plant Biology Bibliography 



CARNEGIE INSTITUTION 



YEAR BOOK pS—pp page 43 



Here updated through December 1 , 1 999. Reprints are available at no charge from the Department of Plant 
Biology, 260 Panama Street, Stanford, California 94305. Please give reprint number(s) when ordering. 



1 378 Adam, L, S. Ellwood, I. Wilson, S. 
Xiao, J. Turner, R. Oliver, and S. G 
Somerville, Comparative studies of disease 
resistance in Arabidopsis thaliana and two 
species of powdery mildew, Erysiphe 
cichoracearum and E. cruciferarum, Mol. 
Plant-Microbe Interact. 12, 1031-1043, 1999. 

1 40 1 Bhaya, D., N. Watanabe, T. Ogawa, 
and A. R. Grossman, The role of an alternate 
sigma factor in motility and pili formation in 
the cyanobacterium Synechocystis sp. Strain 
PCC 6803, Proc Natl. Acad. So. USA 96, 3 1 88- 
3193, 1999. 

1 369 Briggs, W. R, Discovery of pho- 
tochrome, in Discoveries in Plant Biology, Vol. 
2, S.-D. Kung and S.-F. Yang, eds„ World 
Scientific Publishing, Hong Kong, pp. I 1 5- 
135, 1999. 

1413 Briggs, W„ and E. Huala, Blue-light 
photoreceptors in higher plants, Ann. Rev. 
Cell Dev. Biol. 15, 33-62, 1999. 

1432 Broun, P., S. Gettner, and C Somerville, 
Genetic engineering of plant lipids, Ann. Rev; 
Nutr.J9, 197-216, 1999. 

I 380 Christie, J. M., P. Reymond, G. Powell, 
P. Bernasconi, A. A. Raibekas, E. Liscum, and 
W. R Briggs, Arabidopsis NPH I : a flavopro- 
tein with the properties of a photoreceptor 
for phototropism, Science 282, 1 698- 1 70 1 , 



1423 Christie, J. M„ M. Salomon, K. Nozue, 
M. Wada, and W. R. Briggs, LOV (light, oxy- 
gen, or voltage) domains of the blue-light 
photoreceptor, phototropin (nphl): binding 
sites for the chromophore flavin mononu- 
cleotide, Proc. Natl. Acad. Sa. USA, in press. 

1406 Davies, J. D., and A. R. Grossman, The 
use of Chlamydomonas as a model algal sys- 
tem for genome studies,/ Phycol. 34, 907- 
917, 1998. 

1402 Davies, J. P., F. H. Yildiz, and A. R 
Grossman, The involvement of an SNFI -like 
serine-threonine kinase in the acclimation of 
Chlamydomonas reinhardtii to sulfur limita- 
tion, Plant Cell II, I 179-1 190, 1999. 

I 377 Dolganov, N„ and A. R Grossman, A 
polypeptide with similarity to phycocyanin 
a-subunit phycocyanobilin lyase involved in 
degradation of phycobilisomes,/ Bactenol. 
181,610-617, 1999. 

I 379 Field, C. B., M. J. Behrenfeld, J. T 
Randerson, and P. Falkowski, Primary pro- 
duction of the biosphere: integrating terres- 
trial and oceanic components, Science 28 1 , 
237-240, 1998. 



1438 Grossman, A. R., Chloroplast genome 
diversity; from large to small circles, J. Phycol. 
35,893-895, 1999. 

1429 Hoffman, N. E., and A. R. Grossman, 
Trafficking of proteins from chloroplasts to 
vacuoles: perspectives and directions,/ 
Phycol. 35, 3-6, 1 999. 

1430 Jansson, S., S. Green, A. R. Grossman, 
and R. Hiller, A proposal for extending the 
nomenclature of light-harvesting proteins of 
the three transmembrane helix type, Plant 
Molecular Biology Reporter 1 7, 22 1 -224, 
1999. 

1428 Katoh, H., A. R Grossman, and T 
Ogawa, A gene of Synechocystis sp. 
PCC6803 encoding a novel iron trans- 
porter,/ Biol, Chem., in press. 

I 337 Lasceve, G. L, J. Leymarie, A. 
Vavasseur, E. Liscum III, M. Olney, and W. R. 
Briggs, Arabidopsis contains at least four 
independent blue light-activated signal- 
transduction pathways, Plant Physiol. 1 20, 
605-614, 1999. 

1434 Lin, X., S. Kaul, S. Rounsley, T P. Shea, 
M.-l. Benito, C D. Town, C Y. Fujii, T Mason, 
C L Bowman, M. Bamstead, T Feldblyum, C 
R Buell, K. A. Ketchum, C M. Ronning, H. 
Koo, K. Moffat, L Cronin, M. Shen, G. Pai, S. 
Van Aken, L Umayam, L Tallon, J. Gill, M. D. 
Adams, A. J. Camera, T. H. Creasy, H. M. 
Goodman, C. R. Somer/ille, G. P. Copenhaver, 
D. Preuss, W. C Nierman, O. White, J. A. 
Eisen, S. Salzberg, C. M. Fraser, and J. C. 
Venter, Sequence and analysis of chromo- 
some 2 of the plant Arabidopsis thaliana, 
Nature 402,761-768, 1999. 

1433 Ogas, J., S. Kaufmann, J. Henderson, and 
C R Somerville, PICKLE is a CHD3 chromatin 
remodeling factor that regulates the transition 
from embryonic to vegetative development in 
Arabidopsis, Proc. Natl. Acad. Sa USA 96, 
13,839-13,844, 1999. 

1417 Ostrom, E., J. Burger, C B. Field, R. 
Norgaard, and D. Policansky, Revisiting the 
commons: local lessons, global challenges, 
Science 284, 278-282, 1999. 

I 399 Peer, W. A., W. R Briggs, and J. H. 
Langenheim, Shade-avoidance responses in 
two common coastal redwood forest 
species, Sequoia sempervirens (Taxodiaceae) 
and Satureja douglasii (Lamiaceae), occurring 
in various light environments, Am. J. Botany 
86,640-645, 1999. 

1427 Richmond, T, and S. Somerville, 
Chasing the dream: plant EST microarrays, 
Curr. Opin. Plant Biol., in press. 



1 373 Schuenemann, D., S. Gupta, F. 
Persello-Cartieaux, V. Klimyuk, J. D. G. 
Jones, L Nussaume, and N. E. Hoffman, A 
novel signal recognition particle targets light- 
harvesting protein to the thylakoid mem- 
branes, Proc. Natl. Acad. Sa. USA 95, 10312- 
10316, 1998. 

1254 Schuenemann, D„ P. Amin, and N. E. 
Hoffman, Functional divergence of the plas- 
tid and cytosolic forms of the 54 kDa sub- 
unit of signal recognition particle, Biochem. 
Biophys. Res. Comm. 254, 253-258, 1999. 

1412 Shimogawara, K„ D. Wykoff, H. 
Usuda, and A. R. Grossman, Isolation and 
characterization of mutants of 
Chlamydomonas reinhardtii unable to accli- 
mate to phosphorus limitation, Plant Physiol. 
120,685-693, 1999. 

1433 Somerville, C R„ and S. C Somerville, 
Plant functional genomics, Science 285, 380- 
383, 1999. 

1415 Taylor, N. C, W. R Scheible, S. 
Cutler, J. Hoyland, C R. Somerville, and S. R. 
Turner, The irregular xylem 3 locus of 
Arabidopsis encodes a cellulose synthase 
gene required for secondary cell wall syn- 
thesis, Plant Cell I 1,769-779, 1999. 

1408 Toole, C M„ T L Plank, A. R 
Grossman, and L K. Anderson, Bilin deletion 
and subunit stability in cyanobacterial light har- 
vesting proteins, Molecular Microbiol. 30, 475- 



1426 Vogel, J., and S. C Somerville, 
Isolation and characterization of powdery 
mildew resistant Arabidopsis mutants, Proc. 
Natl. Acad. Sa. USA, in press. 

1424 Wykoff, D., A. Grossman, D. Weeks, 
H. Usuda, and K. Shimogawara, Psrl, a 
nuclear localized protein that regulates 
phosphate metabolism in Chlamydomonas 
reinhardtii, Proc. Natl. Acad. Sa. USA 96, 
15,336-15,341, 1999. 



CARNEGIE INSTITUTION 



PAGE 44 I YEAR BOOK p8~pp 



Department of Embryology 



:arnegie institution 



YEAR BOOK p8~pp page 4$ 



THE DIRECTORS INTRODUCTION 



"Staff Associates have come to play a valued role in broadening the 
scope and novelty of departmental research." 



taff Associates have once again provided some 
of this year's highlights. The establishment of 
these independent faculty positions, with a limited 
duration of about five years, was an innovation 
started in this department more than 30 years ago. 
It hasproved to be very successful, providing a 
long succession of scientists with an environment 
in which, they can work undisturbed, typically with 
one associate, on innovative projects that would be 
hard to pursue under other circumstances. In 
recent years, the quality and success of the depart- 
ment's Staff Associates has inspired other institu- 
tions, including the Whitehead Institute, the Fred 
Hutchinson Cancer Research Center, the 
University of Texas Southwestern, and the 
National Cancer Institute, to initiate similar pro- 
grams. Within the department, Staff Associates 
have come to play a valued role in broadening the 
scope and novelty of departmental research. 

This year saw the appointment of two new Staff 
Associates, bringing the total number back up to 
our target level of four. Erika Matunis studies 
stem cells — the rare but critically important cells 
that retain the ability to renew adult tissues by 
division and differentiation. Drosophila has 
recently emerged as an important system for 
studying how stem cells are controlled. These 
elusive cells in the fly can be directly identified and 



analyzed using sophisticated genetic and develop- 
mental techniques. Matunis focuses on the stem 
cells that maintain sperm production in males. 
Her work is revealing genes that control male stem 
cells, and is uncovering fascinating differences 
between the cells that support male and female 
gamete production. 

Terence Murphy analyzes chromosome segrega- 
tion — a subject connected to many other research 
programs in the department. Most genetic func- 
tions are carried out by specific sequences of 
nucleotides located at particular fixed positions on 
the chromosomes. Murphy has been studying cen- 
tromeres — the unique site on each chromosome 
that directs its attachment to the mitotic spindle 
and ensures that exactly one of its two replicated 
copies enters each daughter cell. While working 
with former Carnegie Fellow Gary Karpen and his 
group at the Salk Institute in San Diego, Murphy 
was the first to define a centromere region in a 
chromosome from a multicellular animal at the 
molecular level. Surprisingly, however, Murphy, 
Karpen, and colleagues found that the location 
and sequences used as a centromere could change 
under certain circumstances. At Carnegie, he plans 
to address the molecular mechanisms that control 
such "epigenetic" changes. 



Left: Radiography of adult zebrafish reveals details of skeletal structure. See page 52. 



CARNEGIE INSTITUTION 



page 46 I YEAR BOOK p8~pp 



The Staff Associates have also been in the fore- 
front of a major trend that developed this year. For 
the first time in recent memory, all of our eight 
Staff Member and four Staff Associate positions 
are filled. The number of active scientists in the 
department is at an all-time high, and the com- 
plexity and diversity of their projects are beginning 
to place unprecedented demands on the depart- 
ment's space. In response, we have begun several 
new renovation projects, and expect to hear the 
sounds of construction somewhere in the building 
almost continually during the coming year. One 
such project will make it possible for Jimo Borjigin 
to expand her studies of the pineal gland and its 
role in mediating circadian behavior. A special 
room is being constructed in which the circadian 
rhythms of rodents can be automatically moni- 
tored and recorded. Staff Associate Alejandro 
Sanchez Alvarado is also expanding the scope of 
his research in the molecular biology of planarian 
regeneration. 

The Staff Members are also feeling the space 
shortage. Marnie Halpern is participating in the 
zebrafish genome project by constructing a 



genome-wide collection of deletion chromosomes; 
i.e., chromosomes that lack small, defined regions 
of the genome. To construct these valuable genetic 
tools, it is necessary to grow and examine large 
numbers offish. The facility originally constructed 
to support Halpern's research on developmental 
signaling has now reached full capacity. 
Consequently, plans are under way to add a new 
fish room and to completely renovate the original 
facility so that it can support a higher density of 
fish. Together these projects will expand the 
department's fish-rearing capacity more than 
twofold. Chen-Ming Fan occupies the only labo- 
ratory that has not been upgraded since the build- 
ing was constructed in 1960. Renovation plans 
have been drawn up recently that will improve 
existing space utilization by installing laboratory 
benches with desks for each member of his grow- 
ing group. 

News of the Department 

Our seminar program was highlighted by the 
twenty-second annual minisymposium entitled 
"Biological Clocks." Michael Menaker of the 



<r 



':- 



«? ** 



Members of the Department of Embryology, October 1999. First row (from left): Jie Deng, Jimo Borjigin, Valarie 
Bertoglio, Chris Wiese, Sofia Lizarraga, Marnie Halpern, Jenny Hsieh, Catherine Lee, Kelly Liu. Second row: Ben 
Remo, Jamie Fleenor, Bruce Hodess, Ella Jackson, Ellen Cammon, Dianne Stewart, Rachel Cox, Tim Mical. Third row: 
Xing Sun, Biswajit Das, Joe Gall, Lijun Zhang, Dongli Huang, Jenny Liang, Laura Buttitta, Rosa Alcazar, Eileen Hogan, 
Shannon Fisher, Amy Rubinstein, Pat Cammon. Fourth row: Nick Marsh-Armstrong, Don Brown, Lisa Timmons, 
Ryan Sterner, Luiz Pentaleno-Filho, Alton Etheridge, Nicole Greider, Michel Bellini, Phil Newmark, Bill Kelly, 
Rejeanne Juste, Paul Megee, Bri Lavoie, Haochu Huang, Melissa Pepling, Zengfeng Wang, Ting Xie, Nicole Mozden, 
Horacio Frydman, Andy Fire, Terence Murphy, Zheng'an Wu, Allan Spradling, Yixian Zheng 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 4 J 



University of Virginia, Michael Roshbash of 
Brandeis University, Detlef Weigel of the Salk 
Institute, Martin Raff of University College, 
London, Carol Greider of the Johns Hopkins 
University School of Medicine, and Cynthia 
Kenyon of the University of California, San 
Francisco, each presented a one-hour talk. 

Support for research in the department comes 
from a wide variety of sources. Doug Koshland 
and I, plus various members of our laboratories, 
are employees of the Howard Hughes Medical 
Institute. Others are grateful recipients of individ- 
ual grants from the National Institutes of Health, 
the John Merck Fund, the G. Harold and Leila Y. 
Mathers Charitable Foundation, the American 
Cancer Society, the Jane Coffin Childs Memorial 
Fund, the Damon Runyon-Walter Winchell 
Cancer Fund, the Pew Scholars Program, the 
Alfred P. Sloan Foundation, the National Science 
Foundation, and the Arnold and Mabel Beckman 
Foundation. We also remain indebted to the 
Lucille P. Markey Charitable Trust for its support. 

— Allan Spradling 

JlMO BORJIGIN 

Circadian Rhythms 

Scientists in the Borjigin lab are interested in 
understanding the cellular and molecular mecha- 
nisms that govern circadian rhythms. The pineal 
gland expresses melatonin, one of the most dramat- 
ically regulated hormones, which, because it links 
the body's physiological processes to the daily cycle 
of sunlight and darkness, provides an ideal model 
system for circadian-rhythm research. The scientists 
are focusing on two aspects of pineal rhythms: first, 
they are trying to identify the intracellular and 
extracellular molecules that control or influence 
pineal rhythms, and second, they are examining the 
mechanisms by which neuronal and humoral inputs 
lead to nightly production of melatonin. 

Utilizing a sensitive subtractive hybridization tech- 
nique, the researchers have isolated night pineal 
cDNAs encoding the serotonin N-acetyltrans- 
ferase (NAT), a novel Pineal Night-specific 
ATPase (PINA), and Patched 1 (Ptcl). NAT is 



the rate-limiting enzyme of melatonin formation; 
PINA is a novel, alternatively spliced, pineal, and 
night-specific form of the Wilson disease (WD) 
gene; and Ptcl is a tumor suppressor and a recep- 
tor for Hedgehog proteins that play a key role in 
embryonic development. The group's work indi- 
cates that the nightly production of all three mes- 
sages are controlled primarily by cAMP signaling 
and that the protein products are sensitive to light 
stimulation during dark periods. In addition to 
NAT, PINA, and Ptcl, the scientists have identi- 
fied a number of other diurnalfy regulated mRNAs 
in the rat pineal that appear to be important in 
pineal circadian functions. Understanding the role 
of these diurnal intracellular molecules in pineal 
circadian function is one of their main goals. 

To facilitate molecular dissection of circadian- 
rhythm pathways, the group has established meth- 
ods to examine in vivo the influences of extracellu- 
lar molecules on pineal circadian rhythms. They 
have also developed techniques to express foreign 
proteins in pineals of live animals at high efficien- 
cy, which will allow the Borjigin lab to explore the 
mechanism of action of newly discovered genes. 

Donald D. Brown 
Amphibian Metamorphosis 

The fertilized egg of the frog Xenopus laevis takes 
about one week to become a feeding tadpole. 
Three days later the tadpole forms a small thyroid 
gland. As the tadpole grows, the gland enlarges 
and synthesizes increasing amounts of thyroid hor- 
mone (TH). The concentration of this hormone 
controls the metamorphosis of tadpoles into frogs. 
TH is known to function by binding to a protein 
located in the nucleus of target cells, which in turn 
activates or represses genes. The Brown group has 
studied metamorphosis as a set of complex genetic 
programs, which are controlled by this single, sim- 
ple molecule. 

How can a simple hormone trigger such very 
diverse responses in most of the tissues of a tad- 
pole? To find out the answer, the scientists began 
by identifying many of the genes that are up- or 
down- regulated by TH in several target tadpole 



CARNEGIE INSTITUTION 



page 48 I YEAR BOOK p8~pp 



organs. These include the tail, which dies and is 
resorbed, the limb, which grows and differentiates, 
and the intestine, which is completely remodeled 
during metamorphosis. Next the researchers found 
the exact cell types that express these genes. By 
sequencing the genes that are regulated by TH, 
the team identified the protein that each gene 
encodes. Knowing the identity of the gene and 
where and when it is expressed provided clues on 
the possible role of each gene in metamorphosis. 
One conclusion has been that the extensive thy- 
roid-hormone-induced cell death that occurs con- 
sists of multiple genetic programs. 

Recently, the Brown group has been aided by the 
development of a technique called transgenesis, in 
which any isolated gene can be introduced into the 
genome of a Xenopus embryo before first cleavage. 1 
This guarantees that all the cells of the embryo 
and the tadpole will contain the gene. Using this 
powerful method, the Brown group has tested 
many of their genes and developed functional 
assays for gene function in metamorphosis. 

Some of the discoveries that the group has made 
are as follows: 

The hormone prolactin, previously thought to 






Kroll, K. L, and E. Amaya, Development 1 22, 3 1 73-3 1 83, 1 996. 



Fig. 2. Both control tadpoles and frogs, and those overex- 
pressing growth hormone, are shown. 



be a juvenile hormone for anuran tadpoles, does 
not retard metamorphosis. However, it specifi- 
cally inhibits the tail resorption program, yield- 
ing a powerful tool in the search for the basis of 
cell death in the tail (Fig. 1). 

Growth hormone has the same effect on tad- 
poles and frogs as it does on mammals. It dra- 
matically increases growth (Fig. 2). 

The group has identified two independent meth- 
ods to inhibit functions that are dependent on 
TH; namely, overexpressing either a gene encod- 
ing an enzyme that destroys the hormone, or an 
altered form of the hormone's receptor called a 
dominant negative inhibitor. Both kinds of genes 
are introduced under the control of a specific pro- 
moter. The resulting transgenic animals are unable 
to complete specific sets of functions. These new 
methods are making possible a new approach to 
the age-old problem of amphibian metamorphosis. 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK pS—pp page 4p 



Chen-Ming Fan 

Generating Mouse Models for Human 

Genetic Diseases 

Mouse models provide a powerful tool to study 
human diseases and to allow molecular testing of 
the underlying mechanisms involved. The primary 
goal of Fan's research is to generate mouse models 
for better understanding of human development 
and genetic diseases. The scientists hope that the 
information obtained through basic research will 
be used to find cures or minimize the impact of 
the genetic aberration. 

The group has generated the mouse models lack- 
ing Siml and Sim2 function. Siml and Sim2 are 
two mouse homologs of the Drosophila sim gene, 
which controls the development of the central ner- 
vous system midline cells in the fly. The group has 
cloned and characterized these mouse Sim genes, 2 
and both Siml and Sim2 gene functions have 
been inactivated in the mouse via homologous 
recombination. 

The analyses of Siml mutant mice have led to the 
conclusion that Siml controls the development of 
the anterior periventricular nucleus, the paraven- 
tricular nucleus, and the supraoptic nucleus of the 
hypothalamus. Consequently, in the Siml mutant, 
the neuroendocrine peptide hormones such as cor- 
ticotropin-releasing hormone, thyrotropin-releas- 
ing hormone, somatostatin, vasopressin, and oxy- 
tocin are not produced by the hypothalamus. The 
severe depletion of these homeostasis hormonal 
peptides most likely causes the perinatal lethality 
of Siml mutant mice. 3 The scientists have also 
found that there was a mutant mouse generated in 
the 1960s that displayed identical hypothalamic 
phenotype as Siml. They showed that Siml and 
this mutated gene Arnt2 are coexpressed in the 
hypothalamus and that their protein products 
can bind to each other, suggesting that they 
function together to control the development of 
the hypothalamus. 4 

To their surprise, Siml heterozygous mice are 
obese (Fig. 3). Recently, many of the genetic com- 



2 Fan et al., MCN 7, 1-16, 1996. 

3 Michaud et al., Genes & Development 12, 3264-3275, 1998. 

4 Michaud et al., Mechanisms of Development, in press. 



ponents involved in mouse obesity have been iden- 
tified. While the lateral and ventral hypothalamic 
nuclei have been implicated to control satiety, the 
role of the paraventricular region in obesity is less 
clear. The researchers are currently investigating 
how Siml fits into the genetic pathway of obesity. 
An obese patient has been identified by Dr. Andrew 
Zinn of Southwestern University to carry a muta- 
tion in the SIM1 gene. Collaborative efforts have 
been initiated to use the Fan mouse model to 
understand this corresponding human condition 
and possibly develop a corrective procedure. 




Fig. 3. An obese Siml heterozygous mouse is shown on the 
left. To the right is a control. 



Preliminary analysis of the Sim2 mutant suggests 
that Sim2 is required for the proper development 
of specific craniofacial structures. The primary 
defects when this gene is absent are cleft palate, 
nasal bone abnormality, and trigeminal nerve 
reduction. This is consistent with the possibility 
that Sim2 may contribute to aspects of Down's 
syndrome pathology (the human SIM2 gene is 
located within the Down's syndrome "critical 
region" of chromosome 21). Detailed documenta- 
tion of the affected cartilage and bones is the 
immediate goal. However, overexpression of Siml 
does not appear to recapitulate the trisomy pheno- 
type of Down's syndrome (DS), most likely due to 
the requirement of multiple genes on chromosome 
21 to reproduce the DS phenotype. 



CARNEGIE INSTITUTION 



page J0 I YEAR BOOK p8~pp 



Andrew Z. Fire 

The Fire lab is interested in the mechanisms by 
which cells choose their fates during development, 
and in particular the means by which asymmetry is 
generated. Two types of developmental decisions 
are being studied: early developmental decisions 
between germ line and somatic fates, and later 
decisions between different somatic fates (e.g., 
skin and muscle). 

As an experimental organism, the group uses 
C. elegans because of its genetics, the ease of exper- 
imental manipulation, and the simplicity of its 
development. The studies of germ line/soma 
decisions have focused so far on questions of how 
these two cell populations differ in their capacities 
for gene expression. It appears that germ cells have 
a number of highly active mechanisms to limit the 
expression of somatically expressed genes. Some of 
these mechanisms may act at the level of gene con- 
text or chromatin structure. The scientists would 
like to understand how this regulation is mediated 
and what features of gene expression allow specific 
cells to maintain germ line capacity to produce 
subsequent generations of the organism. 

Much of the analysis of somatic fates has focused 
on the formation of different muscle types during 
embryonic development. Studies of muscle devel- 
opment have been facilitated by the wealth of 
available information about their morphology, 
function, and terminal differentiation products. 
Myogenic decisions during embryogenesis and lar- 
val development result in a variety of different 
muscle types in C. elegans. The analysis at the Fire 
lab is directed toward an understanding of general 
processes responsible for the choice of cell type 
and subsequent tissue patterning. This includes 
what types of factors control and carry out deci- 
sions to undergo myogenesis; what the molecular 
nature is of the blastomere identities that are set 
up in the early embryo and "remembered" during 
cell proliferation; how lineage information is inter- 
preted to determine cell fate; and if there are simi- 
lar activities regulating myogenesis for nematode 
and analogous vertebrate muscles. 



Protein or RNP 
Co-factor 




Cleaved or 
modified 
target RNA ^^ 



(Additional cellular 

degradation 

mechanisms?) 

^_ »\|_ 

Degraded target RNA 



Fig. 4. RNAi model. 



Much of current biological research is technique 
driven. A portion of Fire's research effort is aimed 
at producing tools to address each of the following 
questions for a molecule of interest: When and 
where is the molecule present? What happens if 
expression is prevented? What happens if the mol- 
ecule is provided at an inappropriate time or place? 
What other molecules interact? The lab has been 
involved in developing methods to answer these 
questions based on DNA-mediated transforma- 
tion, as well as on wholemount, in situ hybridiza- 
tion and genetic-deficiency screening. In the 
course of this work, the scientists have developed a 
number of vectors for DNA transformation and 
analysis of expression patterns that have been use- 
ful both for their own work and for work in other 



CARNEGIE INSTITUTION 



YEAR BOOK pS—pp page JZ 



labs in the field. A major technical challenge for 
C. elegans researchers over the next few years will 
be to develop methods for precisely targeting 
mutations to specific genes in their normal 
chromosomal context. 

Joseph G. Gall 

The Cajal Body: Assembly Site for the 

Nuclear Transcription Machinery 

The first step in the expression of any gene is the 
formation of an RNA copy of its DNA. This step, 
referred to as transcription, takes place in the cell 
nucleus. Transcription requires the enzyme RNA 
polymerase and a multitude of processing factors, 
which modify the primary transcript before it is 
exported to the cytoplasm as the functional mes- 
senger RNA. Although the biochemical details of 
transcription and processing of RNA are known in 
considerable detail, relatively little is known about 
their cellular organization. It has been generally 
assumed that the polymerase and various additional 
factors are recruited separately to active genes on 
the chromosomes. Researchers in the Gall lab have 
recently proposed an alternative model in which 
the RNA machinery is preassembled as a unitary 
particle completely separate from the chromo- 
somes. This particle, which they call a transcripto- 
some, is recruited to the sites of active genes, bring- 
ing the entire transcription machinery to the genes 
as a single packet. This model is based on cytolog- 
ical and molecular studies of animal cell nuclei. 

Much of the lab's work is carried out on oocytes of 
the frog Xenopus. An oocyte is an egg before it is 
laid by the female; in Xenopus it is a single giant 
cell up to 1.5 mm in diameter. The nucleus of the 
oocyte is equally large, about 0.4 mm in diameter, 
and can be hand-isolated from the oocyte. For his- 
torical reasons, the oocyte nucleus is usually called 
the germinal vesicle, or simply GV. The large size 
of the GV permits one to examine the contents of 
a cell nucleus in unprecedented morphological 
detail. At the same time, many biochemical studies 
can be carried out on single hand-isolated GVs or 
small numbers of GVs. 



The scientists have focused their attention on 
structures in the GV called Cajal bodies, first seen 
in the nuclei of nerve cells nearly 100 years ago by 
the Spanish neurobiologist Ramon y Cajal. They 
have shown that Cajal bodies contain many, if not 
all, factors required for transcription and process- 
ing of messenger RNA, including RNA poly- 
merase II and factors required for initiation, splic- 
ing, cleavage, and polyadenylation of the RNA 
transcript. Remarkably, Cajal bodies also contain 
the special factors required for transcription and 
processing of ribosomal RNA (polymerase I and 
its associated factors), as well as polymerase III, 
which transcribes certain small RNAs. The GV is 
an ideal system in which to study not only the sites 
where specific factors are found, but also where 
they are assembled into macromolecular complexes. 
This can be done by injecting factors into the cell 
and observing where they go initially, and where 
they end up after a longer time. From experiments 
of this sort, the scientists conclude not only that 
the transcription machinery exists in the Cajal 
bodies, but that a significant fraction of it must 
be assembled there. 

In future experiments, the Gall lab hopes to learn 
how various factors are recruited to the Cajal bodies 
and how they assemble into the large transcripto- 
some complexes. The researchers are also trying to 
isolate transcriptosomes from oocytes to determine 
their composition and structure in more detail. 

Marnie Halpern 

The Halpern laboratory uses genetic approaches in 
the zebrafish to study how signaling pathways in a 
vertebrate embryo lead to correct patterning of 
adult structures. Several mutations have been iden- 
tified that transform the fates of embryonic cells so 
that cells that should form muscle (a more dorsal 
fate) give rise instead to blood (a ventral fate). 
Surprisingly, for one of the identified genes, 
chordin, which encodes an antagonist of ventraliz- 
ing signals, some mutant embryos can sufficiently 
regulate to develop into fertile adults. However, 
these fish have defective skeletons and abnormal or 
missing caudal fins (Fig. 5). A normal vertebral 
column is restored in the adult by overexpressing 



CARNEGIE INSTITUTION 



PAGEJ2 I YEAR BOOK p8~pp 



N *X><>4X 



Fig. 5. Radiography of adult zebrafish reveals details of skele- 
tal structure. On top is a homozygous chordin mutant with 
irregularly shaped bones in the caudal skeleton and no tail 
fins. On the bottom is a chordin mutant whose skeletal 
defects were corrected by the introduction of chordin RNA 
during embryonic development several weeks before the for- 
mation of the vertebral column. The images were taken in a 
Faxitron MX-20 cabinet x-ray, with a four-second exposure 
at threefold magnification. 



chordin RNA in the mutant embryo. This finding 
reveals an early requirement for Chordin for cor- 
rect patterning of the adult skeleton, and has led to 
a search for other genes involved in bone differen- 
tiation and morphogenesis. Through a mutational 
screen of live, anesthetized fish using x-rays, post- 
doctoral fellow Shannon Fisher aims to identify 
dominant mutations that perturb the skeleton, and 
thereby identify other new genes that are involved 
in specifying and patterning adult bones. 

Studies of zebrafish mutants are also revealing 
molecular mechanisms that underlie development 
of the vertebrate central nervous system, and most 
recently, left-right differences in the vertebrate 
brain. In collaboration with Chris Wright's group 
at the Vanderbilt Medical School, the Halpern 
group found that zebrafish cyclops encodes a nodal- 
related, TGF-beta signaling family member that is 
involved in patterning the midline of the neural 
tube. Postdoctoral fellow Amy Rubinstein has 
been examining other genes transcribed in the 
early embryo that depend on Cyclops signals for 
their correct expression. Interestingly, cyclops is 
also expressed asymmetrically later in embryogene- 
sis in two places: the left lateral-plate mesoderm, 



WT MUT WT MUT WT MUT Blank 



Fig. 6. Visualization of the cleavage product of cytosolic 
phospholipase A 2 (cPLA 2 ) using fluorescent lipid substrates 
and thin layer chromatography is an efficient way to monitor 
the activity present in single embryo extracts. This method is 
used to identify mutations (MUT) in the zebrafish that alter 
normal levels of enzymatic activity (WT). 



which is thought to influence patterning of the 
heart, and the left dorsal forebrain. Postdoctoral 
fellow Jennifer Liang is exploring how transient 
left-sided signaling in the brain is regulated and 
what its functional significance may be. To do 
this, mutant embryos with midline defects are 
transiently rescued by RNA injection, but not long 
enough to restore left-sided gene expression in the 
brain. Thus, the role of asymmetric signals in the 
developing forebrain can be assessed by the conse- 
quences on the neuroanatomy and behavior of the 
adult fish. 

To capitalize on the accessibility and optical clarity 
of the fish embryo, methods have also been devised 
for direct visualization of protein action during sig- 
naling processes. Initially, postdoctoral fellow Steve 
Farber focused on phospholipase A 2 (PLA 2 ), which 
cleaves phospholipids to liberate potent lipid sig- 
nals and is present in high levels in the developing 
zebrafish. The subcellular localization of PLA 2 
activity was revealed in living embryos using fluo- 
rescently quenched lipid substrates that fluoresce 
upon cleavage. Moreover, uptake of these lipid 
substrates by cells of the intestinal epithelium per- 
mits monitoring of lipid metabolism in the newly 
formed digestive system. One aim is to use these 
and other fluorescent reporters in genetic screens 
for functional modulators of activity (Fig. 6) and 
for real-time imaging of enzyme action during 
development. 



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YEAR BOOK p8~pp page JJ 



Douglas Koshland 

Replicated chromosomes (sister chromatids) 
acquire three specific structural features that are 
important for chromosome segregation in mitosis. 
First, each sister chromatid has a centromere that 
mediates the attachment and the movement of 
chromosomes on the spindle. Second, sister chro- 
matids are paired. Pairing is needed to establish a 
stable bipolar attachment of sister chromatids to 
microtubules of the mitotic spindle, which in turn 
ensures that sister chromatids segregate from each 
other during anaphase. Additionally, the dissolu- 
tion of pairing appears to be a key event in govern- 
ing the onset of chromosome segregation. Third, 
sister chromatids are condensed. This condensation 
helps to minimize entanglement of chromosomes 
while they move during mitosis, and shortens the 
chromosomes so that they are always displaced 
from the cytokinetic furrow at the end of mitosis. 

Much of our understanding of mitotic chromo- 
some function and structure has come from the 
study of vertebrate and invertebrate cells using 
cytology and established biochemical assays. More 
recently, studies using the budding yeast, 
Saccharomyces cerevisiae, have also begun to make 
significant contributions to the field. This simple 
eukaryote is amenable to extensive genetic analysis; 
and researchers have determined the specific DNA 
sequences required for the function of cen- 
tromeres, telomeres, and origin of replications. 
With this knowledge it has been possible to 
manipulate the structure of endogenous chromo- 
somes, as well as generate novel artificial chromo- 
somes. Genetic and biochemical studies have also 
identified key genes encoding histones, topoiso- 
merases, centromere proteins, and cell cycle regu- 
lators. Mutations in these genes provide important 
tools to manipulate both chromosomes and the 
cell cycle in vivo. 

The Koshland group has developed three new 
assays for analyzing mitotic chromosomes in the 
budding yeast: an in vitro assay for centromere- 
microtubule interactions, a fluorescent in situ 
hybridization assay for following sister chromatid 
pairing and condensation, and a chromatin 
immunoprecipitation assay for monitoring in vivo 



binding of proteins to chromosomes at specific 
sites. Using these assays and yeast genetics, the 
group has characterized yeast centromere function 
in vitro, identified and characterized centromere 
components (Mif2p, Cse4p, and Cep3p), identi- 
fied a potential nucleosome-based centromere core 
conserved from yeast to humans, and revealed both 
centromere movement and regulation during the 
cell cycle. Koshland's team has also identified and 
characterized two new classes of proteins important 
for sister chromatid pairing and condensation. The 
first is Pdslp: a cell cycle regulator important for 
the control of the metaphase/anaphase transition, 
for the exit of mitosis, and for cell cycle arrest in 
response to DNA and spindle damage. The second 
class, Smc proteins, is a family of chromosomal 
proteins, conserved from bacteria to humans that 
are essential in diverse eukaryotes for processes 
involving higher-order chromosome structure, 
including chromosome condensation, sister chro- 
matid cohesion, dosage compensation, and recom- 
bination repair. Recently the scientists identified 
non-Smc subunits required for condensation and 
cohesion. The study of these proteins provided 
novel links between cohesion and condensation, 
and between cohesion and DNA replication. The 
team has also been able to map cohesion sites on 
chromosomes, demonstrating that the centromere 
nucleates the assembly of cohesion factors onto at 
least several kilobases of DNA flanking the cen- 
tromere. Further analyses of these proteins and 
sites will provide insight into higher-order 
chromosome folding, as well as genome organiza- 
tion and stability. 

Erika Matunis 

Stem cells have the ability to replicate indefinitely 
and can also give rise to more specialized tissue 
cells in response to appropriate environmental 
cues. Because of their unique regenerative proper- 
ties, stem cells are the focus of much research. 
However, because stem cells are usually rare and 
reside in complex environments, little is known 
about how they behave in vivo. Since the regulatory 
mechanisms discovered in simpler model organisms 
often apply to complex systems as well, the 
Matunis lab is studying stem cells that sustain 



CARNEGIE INSTITUTION 



page 54 I YEAR BOOK p8~pp 



spermatogenesis in the fruit fly Drosophila 
melanogaster. Stem cells in the Drosophila testis are 
easy to identify, reside in a well-defined environ- 
ment, and are amenable to both experimental and 
genetic manipulation. The researchers' goal is to 
use genetics to identify the environmental cues 
that regulate stem cells in the Drosophila testis. 

Spermatogenesis begins when a germ line stem 
cell (gsc) divides, producing one cell that remains a 
gsc and can replicate indefinitely, and another cell 
(called a gonial cell) with a very different fate. 
Unlike gscs, gonial cells cannot divide indefinitely. 
Instead they differentiate, ultimately producing a 
bundle of sperm. When the gsc divides then, how 
does it give rise to two cells with such different 
fates? Perhaps the gsc receives a signal from its 
environment that allows it to remain a stem cell, 
while the gonial cell is displaced away from the 
signal, thus causing it to lose the stem cell fate. 
This type of mechanism is hypothesized to operate 
in many stem cell systems, but has been extremely 




difficult to prove. Interestingly, gscs in the 
Drosophila testis (Fig. 7; indicated by the arrow- 
head) are attached to a small cluster of cells called 
the hub (indicated by the thin arrow), and as 
gonial cells are created (thick arrow), they are dis- 
placed away from the hub. The hub is thus a good 
candidate for a source of signals that influence the 
gsc divisions. But does such a signal exist? To 
search for it, researchers can remove genes that 
encode signaling molecules from cells in the testis 
and look for a corresponding loss of gscs. Such 
genes should encode signals that are needed to 
maintain the gsc fate. Using this approach, 
Matunis's lab has found that the Jak-Stat signaling 
pathway is needed to maintain gscs. In this path- 
way, receptor-associated cytoplasmic protein tyro- 
sine kinases (Janus, or Jak kinases) are catalytically 
activated upon ligand binding, and activate tran- 
scription factors in the signal transducer and acti- 
vator of transcription (Stat) family. The scientists 
are currently trying to determine if the Jak-Stat 
pathway is activated directly in the gscs, or in 
nearby cells in their environment. They are also 
looking for the ligand that activates the Jak-Stat 
pathway during spermatogenesis. Once this ligand 
is identified, they will determine which cells in the 
testis are producing it. This should give them a 
detailed picture of how an environmental cue reg- 
ulates stem cells at a level of detail not possible in 
more complex stem cell systems. Furthermore, 
since Jak-Stat signaling is required for the function 
of mammalian stem cells, notably during 
hematopoiesis, the knowledge gained here will 
likely apply to such stem cell systems. 

Terence Murphy 

The term chromosome means colored body, but this 
description hardly does them justice. As the main 
bearers of genetic information in the cell, chromo- 
somes serve an essential role throughout the cell 
cycle. Yet their primary role is not revealed until 
cell division, at which time they undergo an intri- 
cate series of movements to ensure that each 
daughter nucleus receives an identical complement 
of genetic material. The fidelity of this process is 
amazing: natural chromosomes in the budding 
yeast Saccharomyces cerevisiae are lost only once in 



c 



:arnegie institution 



YEAR BOOK p8—pp page 55 



every 100,000 divisions. The consequences of mis- 
takes are equally staggering. Gain or loss of a 
chromosome (aneuploidy) in every cell of an 
organism is typically lethal or results in severe 
birth defects such as Down's syndrome. 
Aneuploidy is also associated with cancer progres- 
sion, aging, Alzheimer's disease, developmental 
disorders such as Robert's syndrome, and even one 
type of bacterial infection, thus providing a con- 
siderable impetus for studying the mechanics of 
chromosome inheritance. 

Chromosome inheritance requires a coordinated 
series of interactions between chromosomes and 
the mitotic spindle. Spindle attachments primarily 
occur at a single site on each chromosome called 
the centromere, which nucleates a large proteina- 
ceous structure called the kinetochore. The kineto- 
chore attaches to microtubules and helps direct 
chromosome movements along the spindle. But 
how do centromeres work? For many years, 
researchers have postulated that centromeres 
would function in a manner analogous to gene 
prompters — that is, unique DNA sequences on the 
chromosome would be bound by specific DNA- 
binding proteins, which in turn would mediate the 
attachment to microtubules. However, a growing 
body of data suggests that in many eukaryotes this 
is not the case. Centromeres in multicellular 
eukaryotes are primarily composed of highly repet- 
itive satellite sequences that vary substantially from 
one centromere to the next, and are not evolution- 
arily conserved. Also, centromeres have been 
found to change their functional state (i.e., turn off 
or turn on) without detectable changes in DNA 
sequence. These paradoxes have led researchers to 
propose that centromeres are partially epigenetic: 
that is, centromeres are specified not by DNA 
sequence but by a special mark on the chromo- 
some, such as a DNA modification or a unique 
chromatin structure that can be copied from the 
original centromere to the nascent centromeres 
during chromosome replication. 

An epigenetic model for centromere function is 
consistent with the available data, but very little is 
known about the nature of the mark or how it is 
copied during chromosome replication. Murphy is 




Fig. 8. The typical behavior of a dicentric chromosome 
during anaphase is shown. The two centromeres are moving 
to opposite poles, stretching the intervening chromatin 
into a dicentric bridge (arrow) that will eventually break. 
Chromosomes are shown in dark gray, centromeres in light 
gray. (Image courtesy of Byron Williams.) 



constructing an assay in Drosophila that will direct- 
ly measure the frequency at which centromeres are 
epigenetically turned off by assaying the behavior 
of chromosomes with two centromeres (dicentric 
chromosomes) (Fig. 8). This assay will in turn 
allow the identification of genes that are involved 
in copying the centromere mark during chromo- 
some replication, as well as other genes connected 
with centromere function such as microtubule- 
based motors. To complement this assay, Murphy 
is also constructing a set of in vivo tools that will 
aid in the analyses of genetic mutations that affect 
chromosome inheritance. Together, these tools 
will allow dissection of the genes and mechanisms 
controlling the behavior of chromosomes during 
cell division. 

Alejandro Sanchez Alvarado 
Animal Regeneration 

Regeneration is a fundamental attribute of all liv- 
ing things, whether it be simple tissue restoration 




CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



or the complete replacement of lost body parts 
such as limbs, tails, or even heads. As a biological 
problem, regeneration began to be studied formal- 
ly over 250 years ago in crustaceans by Rene- 
Antoine Ferchault de Reaumur (1683-1757), and 
soon after in hydra by Abraham Trembley (1710- 
1784). A long-standing problem of biology, regen- 
eration in metazoans still awaits a satisfactory 
mechanistic explanation. The laboratory's goal is 
to identify and study the molecular components 
underpinning this phenomenon. The researchers 
are approaching the problem by analyzing and 
manipulating the regenerative properties found in 
both vertebrate and invertebrate organisms. 

As a vertebrate model, the Sanchez Alvarado lab 
uses amphibian tadpoles {Xenopus laevis and Rana 
temporaria), whose tails regenerate to completion 
after amputation. These studies aim to identify a 
complement of genes operating during tail regen- 
eration. To date, nearly 20 genes upregulated by 
the process of regeneration have been identified in 



Control 6 hours 




o 



Sanchez Alvarado and Newmark 



Fig. 9. Abrogation of gene expression in planarians using 
double-stranded RNA is shown here. A schematic represen- 
tation of the planarian photoreceptor is shown on the left; 
the pigment cup is c-shaped and the retinular, light-sensing 
cells in light gray (after von Graff, L. ( 1 9 1 2- 1 9 1 7), in Klassen 
und Ordnungen des Tier-Reichs, vol. 4, H. G. Bronn, ed., C. F. 
Winter'sche Verlangshandlung, Leipzig). The light-gray cells 
express the gene for opsin, a protein involved in mediating 
phototransduction. The control panel shows a section of the 
planarian Schmidtea mediterranea photoreceptor injected with 
water as a control, and also shows the cells where opsin 
RNA is present as detected by in situ hybridization (in dark 
gray). The remaining panels show what happens to the opsin 
RNA 6, 12, and 24 hours after opsin double-stranded RNA 
(instead of water) is injected into the animals. 



Rana temporaria tadpoles, and their temporal and 
spatial expression patterns are being elucidated. 

The invertebrate organisms the scientists chose are 
members of the phylum Platyhelminthes and are 
commonly known as planarians, or flatworms. The 
uncanny regenerative abilities of these triploblastic 
animals have been known for many years. In fact, 
work on planarian regeneration dates back to the 
work of the German naturalist Peter Simon Pallas 
(1741-1811) and has continued ever since. The 
group studies Schmidtea mediterranea, a stable 
diploid with a genome size slightly larger than that 
of Dros op hi la. Thus far, the researchers have iden- 
tified over 30 regeneration-modulated and region- 
ally enriched genes, and have shown that gene 
expression in these animals can be silenced by 
double-stranded RNA. More recently the group 
has succeeded in specifically labeling planarian 
neoblasts — the stem cell population at the root of 
the regenerative prowess of planarians. With the 
tools of ablating gene expression and labeling 
neoblasts, the scientists will be able to vertically 
integrate what is learned from planarians into the 
study of regeneration in higher organisms. 

Future research in the laboratory will involve the 
creation of transgenic planarians using neoblasts as 
vectors for the introduction of DNA, as well as a 
more extensive delineation of the transcription 
programs activated during the events of metazoan 
regeneration using DNA microarrays. Further 
information on the laboratory's activities can be 
found at http://www.ciwemb.edu/links/ 
research_blurbs/sanchez/sanchezresearch.html. 

Allan Spradling 

Structure and Function of Female 

Germ Cells 

Each generation, germ line cells carry out two 
major functions. First, they propagate their own 
intricate, information-rich contents in an essen- 
tially undamaged state, thereby continuing an 
unbroken chain of inheritance from their germ cell 
ancestors stretching back billions of years. 
Secondly, female germ cells choreograph early 
embryonic development, which establishes essen- 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp page J7 



tial conditions for germ line-derived somatic cells 
to produce a new, but transient organism. The 
Spradling lab studies several of the processes germ 
cells use to accomplish these fundamental tasks by 
conducting molecular genetic studies of the fruit 
fly Drosophila and of mice. 

How can germ line cells proliferate, seemingly 
without limit, while somatic cells age and die? 
One group of cellular organelles, the mitochon- 
dria, produce energy by oxidative processes that 
generate highly reactive and potentially damaging 
by-products. Despite this, mitochondria contain 
their own small genome, encoded by mitochon- 
drial DNA. Damage to mitochondrial DNA 
has recently been shown to cause several human 
diseases, and to occur spontaneously in aging 
somatic cells. Spradling's group has begun to ana- 
lyze how new mitochondria are produced during 
the process of egg formation and to learn how 
germ cells are able to furnish succeeding genera- 
tions of somatic cells with functional, undamaged 
mitochondrial genomes. 

Spradling believes that keys to understanding this 
and several other aspects of germ cell biology can 
be found during a little-studied, early stage of 
germ cell development, when small groups of germ 
cells transiently become interconnected with one 
another into cell clusters. During this time, mem- 
brane-rich cellular constituents, including mito- 
chondria, aggregate within an unusual structure — 
the fusome — that extends throughout all the cells 
in the cluster. The scientists are identifying the 
genes and mechanisms used to program cell cluster 
and fusome formation, and are gaining insight into 
the function of these processes. 

Even earlier in their generational cycle, Drosophila 
germ cells proliferate extensively as stem cells. 
Germ line stem cells represent one of the best sys- 
tems currently available to study the molecular 
mechanisms that control stem cell proliferation — 
a fundamental process underlying the maintenance 
of many adult tissues. The lab's work has implicat- 
ed the regulated translation of stored messenger 
RNAs as a critical process used by stem cells and 
has identified a likely key target of such regulation. 



Moreover, the researchers discovered extracellular 
signals from nearby somatic cells that are needed 
to maintain the stem cell's fate. They are also 
studying mechanisms that germ line cells use 
to silence the expression of unwanted genes, 
such as those of invading viruses and transposable 
elements. 

Finally, Spradling and his lab members recognize 
that progress in biology often comes from 
improved methods. They continue to participate 
in the Drosophila genome project. Their current 
goal is to further facilitate studies of gene 
function by isolating insertional mutations in 
greater than 85% of all genes identifiable in the 
genome sequence. 

Yixian Zheng 

Microtubule Nucleation and 
Organization in Response to Cell Cycle 
and Developmental Signals 

How a cell organizes its interior and how it divides 
are central questions in cell and developmental 
biology. Research in the Zheng lab focuses on 
understanding how different microtubule arrays 
are nucleated and are organized in response to cell 
cycle and developmental signals. Microtubules are 
tiny filaments found in all eukaryotes. They are 
essential for intracellular organization and mitosis. 

The major microtubule nucleation site inside an 
animal cell is the centrosome. One research avenue 
in the Zheng lab is to understand the structure and 
function of the centrosome using Xenopus and 
Drosophila as model systems. The centrosome con- 
sists of a pair of centrioles and an electron-dense 
pericentriolar material (PCM), which harbors the 
activity for microtubule nucleation and organiza- 
tion. The scientists in Zheng's lab discovered a y- 
tubulin-containing ring complex (tTuRC) in the 
two organisms and found that it can nucleate 
microtubules in vitro. Additionally they found that 
7TuRC is essential for centrosomes to nucleate 
microtubules. Zheng's current hypothesis is that 
the tTuRC is the major microtubule nucleator at 
the PCM. tTuRC consists of approximately five, 
presently uncharacterized, proteins in addition to 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



7-tubulin. The team is using a combination of 
molecular genetic, biochemical, and genetic 
approaches to understand this ring complex. The 
researchers are particularly interested in addressing 
how the tTuRC is involved in regulating micro- 
tubule-nucleating activity of the centrosome, how 
it is recruited and assembled at the PCM, and 
whether (and how) it is involved in centrosome 
duplication. 

Another research direction in the lab is to under- 
stand the signals that regulate spindle assembly 
during mitosis. In animal cells, the transition from 
interphase to mitosis is accompanied by dramatic 
changes in cellular architecture such as nuclear 
envelope breakdown, chromosome condensation, 
and spindle formation. The reorganization of the 
interphase microtubule array into a highly dynamic 
mitotic spindle requires more than the presence of 
centrosomes and the conversion of cytosol into a 
mitotic state. Several studies have found that 
nuclear signals released into the cytoplasm upon 
nuclear envelope breakdown exert many different 
effects on microtubule arrays. Recently, the Zheng 
group discovered that the small nuclear GTPase, 
Ran, can stimulate microtubule aster and spindle 
formation in the absence of both centrosomes and 
chromosomes. These findings suggest that Ran is 
the nuclear signal that regulates microtubule 
assembly in mitosis. 

Future projects in the lab will involve dissecting 
the mechanism of the Ran signaling pathway in 
mitosis. The Zheng lab has shown that RanGTP 
can stimulate not only microtubule polymerization 
but also microtubule organization in mitosis. They 
are now developing assays to help identity the 
downstream targets of RanGTP. 



Department of Embryology Personnel 



:arnegie institution 



YEAR BOOK p8~yp page $p 



Research Staff Members 

Donald D. Brown 
Chen-Ming Fan 
Andrew Z. Fire 
Joseph G. Gall 
Marnie Halpern 
Douglas E. Koshland 
Allan C. Spradling, Director 
Yixian Zheng 

Staff Associates 

Jimo Borjigin 
Erika Matunis 2 
Terence Murphy 3 
Alejandro Sanchez Alvarado 

Postdoctoral Fellows and Associates 

Michel Bellini, Markey Charitable Trust 

Brian Calvi, Markey Charitable Trust 4 

Rachel Cox, Helen Hay Whitney Foundation Fellow 5 

Biswajit Das, Mothers Charitable Foundation (Brown) 

Maggie de Cuevas, Howard Hughes Research 

Associate, NIH Grant (Spradling) 
Daniela Drummond-Barbosa, NIH Fellow, 

Carnegie Fellow 
Steve Farber, NIH Fellow, McClintock Fellow 
Shannon Fisher, NIH Fellow 
Nicole Grieder, European Molecular Biology 

Organization, Carnegie Fellow 
Vincent Guacci, Carnegie Fellow, NIH Grant 

(Koshland)* 
William Kelly, NIH Grant (Fire) 
Shika Laloraya, Howard Hughes Research Associate 
Bngitte Lavoie, Canadian Research Council, 

Carnegie Fellow 
Jennifer Liang, NIH Fellow, Markey Charitable Trust, 

Carnegie Fellow 
Kelly Liu, NIH Fellow, Carnegie Fellow 
Nick Marsh-Armstrong, NIH Grant (Brown) 
Paul Megee, Howard Hughes Research Associate 
Timothy Mical, Carnegie Fellow, Markey Charitable 

Trust 
Jacques Michaud, Medical Research Council of 

Canada 7 
Phil Newmark, NIH Fellow 
Melissa Pepling, Howard Hughes Research Associate 
Amy Rubinstein, NIH Fellow, Carnegie Fellow, 

Markey Charitable Trust 
Alex Schreiber, Markey Charitable Trust? 
Robert Skibbens, NIH Fellow, Carnegie Fellow 9 
Xing Sun, Carnegie Fellow' 
Lisa Timmons, NIH Fellow, Carnegie Fellow 
Alexei Tulin, Howard Hughes Research Associate" 
Zengfeng Wang, Howard Hughes Research Associate 
Christiane Wiese, Markey Charitable Trust, American 

Cancer Society, Carnegie Fellow 
Andrew Wilde, Carnegie Fellow 
Zheng'an Wu, Research Associate, NIH Grant (Gall) 
Ting Xie, Howard Hughes Research Associate 



Predoctoral Fellows and Associates 

Rosa Alcazar, Johns Hopkins University 
Valarie Bertoglio, Johns Hopkins University 
Laura Buttitta, Johns Hopkins University 
Olivia Doyle, Johns Hopkins University 
Horacio Frydman, Johns Hopkins University 
Ru Gunawardane, Johns Hopkins University 
Korie Handwerger, Johns Hopkins University 
jenny Hsieh, Johns Hopkins University 
Dongli Huang, Johns Hopkins University 
Haochu Huang, Johns Hopkins University 
Steve Kostas, Johns Hopkins University 
Catherine Lee, Johns Hopkins University 
Sofia Lizarraga, Johns Hopkins University 
Susan Parrish, Johns Hopkins University 

Supporting Staff 

Betty Addison, Laboratory Helper 

Kristin Belschner, Photographer (P J.) I Amphibian 

Facility Technician (P.T.) 
Ellen Cammon, Laboratory Helper 
Patricia Cammon, Laboratory Helper 
Jie Deng, Technician' 

Pat Englar, Director's Administrative Assistant 
Rachel Fasnacht, Technician 10 
Jamie Fleenor, Technician 
Eleni Goshu, Animal Care Technician' 2 
Amy Hennessey, Fish Facility Technician 
Linda Henry, Administrative Assistant 
Bruce Hodess, Animal Care Technician 
Eileen Hogan, Senior Technician 
Ella Jackson, Laboratory Helper' 3 
Connie Jewell, Graphic Artist 
Glenese Johnson, Laboratory Helper 
Rejeanne Juste, Technician 
Susan Kern, Business Manager 
Bill Kupiec, Computer Systems Manager 
Tong Tong Liu, Technician 
Michelle Macurak, Technician 
Ona Martin, Senior Technician 
Noah May, Technician 
Ronald Millar, Building Engineer 
Cathy Mistrot, Technician'* 
Nicole Mozden, Technician 
Christine Murphy, Senior Technician 
Christine Norman, Howard Hughes Medical Institute 

Research Secretary 
Allison Pinder, Research Technician III 
Earl Potts, Custodian 
Benjamin Remo, Technician 
Ronald Roane, Animal Care Technician 5 
Michael Sepanski, Electron Microscopy Technician 
Loretta Steffy, Accounting Assistant 
Erin Sterner, Laboratory Helper' 5 
Dianne Stewart, Research Technician III 
Allen Strause, Machinist 
Natalia Tulina, Technician' 6 
John Watt, Librarian 
Lijun Zhang, Technician 



Visiting Investigators and 
Collaborators 

Kiyokazu Agata, Himeji Institute of Technology, Japan 

Francesc Cebria, University of Barcelona 

James Clark, Genetics Institute 

Knsten Crossgrove, Loyola College of Maryland 

Richard Elinson, University of Toronto 

Elizabeth Hendrickson, University of Washington 

Stewart Hendrickson, University of Washington 

Paul Henion, Ohio State University 

Phil Hieter, Johns Hopkins School of Medicine 

Andrew Hoyt, Johns Hopkins University 

Casonya Johnson, Morgan State University 

Michael Krause, National Institutes of Health 

William F. Marzluff, University of North Carolina, 

Chapel Hill 
Craig Mello, University of Massachusetts 
Karen Oegema, European Molecular Biology Lab, 

Heidelberg, Germany 
Michael Pack, University of Pennsylvania 
Robert E. Palazzo, University of Kansas 
Rafael Romero, University of Barcelona 
Gerald M. Rubin, University of California, Berkeley 
Lila Solnica-Krezel, Vanderbilt University 
Christopher V. E. Wright, Vanderbilt University 

Medical School 



'From August I, 1998 
! From October 1 , 1 998 
'From August II, 1999 
To December 31, 1998 
s FromJune7, 1999 
To October 3 1 , 1998 
To March I, 1999 
B From August 6, 1998 
To August 31, 1999 
'"From January I, 1999 
"From July I, 1998 
Trom January 20, 1999 
i: fromJune I, 1999 
Trom October 19, 1998 
Trom May 13, 1998 
"From February 8, 1999 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



Department of Embryology Bibliography 



Abbott, J., W. F. Marzluff, and J. G. Gall, The 
stem-loop binding protein (SLBPI) is present in 
coiled bodies of the Xenopus germinal vesicle, 
Mol. Biol. Cell 10, 487-499, 1999. 

Ashbumer, M., S. Misra, J. Roote, S. Lewis, R. 
Blazej, T. Davis, C. Doyle, R Galle, R George, N. 
Hams, D. Harvey, L Hong, K. Houston, R 
Hoskins, C. Martin, A. Moshrefi, M. Palazzolo, A. 
Spradling, G Tsang, K. Wan, K. Whitelaw, G B. 
Kimmel, S. Celniker, and G. M. Rubin, An explo- 
ration of the sequence of a 2.9-megabase region 
of the genome of Drosophila melanogaster — the 
"Adh region," Genetics 153, 179-219, 1999. 

Bellini, M., and J. G Gall, Coilin shuttles between 
the nucleus and cytoplasm in Xenopus oocytes, 
Mol. Biol. Cell 9, 2987-300 1 , 1 999. 

Berry, D„ G Rose, B. Remo, and D. D. Brown, 
The expression pattern of thyroid hormone 
genes in remodeling tadpole tissue defines dis- 
tinct growth and resorption gene expression 
programs, Dev. Biol. 203, 24-35, 1998. 

Berry, D., R. Scwartzman, and D. D. Brown, The 
expression pattern of thyroid hormone response 
genes in the tadpole tail identifies multiple 
resorption programs, Dev. Biol. 203, 1 2-23, 1 998. 

Borjigin, J., J. Deng, M. M. Wang, X. Li, S. 
Blackshaw, and S. H. Snyder, Orcadian rhythm of 
patched I transcription in the pineal regulated by 
adrenergic stimulation and cAMP.J. Biol. Chem. 
274,35,012-35,015, 1999. 

Borjigin, J., X. Li, and S. H. Snyder, The pineal 
gland and melatonin: molecular and pharmaco- 
logic regulation, Ann. Rev. Pharmacology & 
Toxicology 39, 53-65, 1999. 

Borjigin, J., A. S. Payne, J. Deng, X. Li, M. M. 
Wang, B. Ovodenco, J. D. Gitlin, and S. H. 
Snyder, A novel pineal night-specific ATPase 
encoded by the Wilson Disease gene, 
J. Neurosa. 1 9 (3), 1 1 8- 1 026, 1 999. 

Calvi, B., and A. C Spradling, Chonon gene 
amplification in Drosophila: a model for meta- 
zoan ongins of DNA replication and S phase 
control, Methods: A Companion to Methods in 
Enzymology 1 8, 407-417, 1999. 

Cohen-Fix, O., and D. Koshland, Pdslp of bud- 
ding yeast has dual roles: inhibition of anaphase 
initiation and regulation of mitotic exit, Genes 
Dev. 13, 1950-1959, 1999. 

Crews, C S., and C.-M. Fan, Passing in the wind: 
regulation of vascular system, nervous system, 
and appendage development by bHLH-PAS 
proteins, Curr. Opin. Genet. Dev. 9, 524-53 I , 
1999. 

Dej, K., and A. C. Spradling, The endocycle con- 
trols nurse cell polytene chromosome structure 
during Drosophila oogenesis, Development 1 26, 
293-303, 1999. 

Elinson, R. P., B. Remo, and D. D. Brown, Novel 
structural elements during tail resorption in 
Xenopus metamorphosis: lessons from tailed 
frogs, Dev. Biol. 2 1 5, 243-252, 1 999. 

Farber, S. A., E. S. Olson, J. D. Clark, and M. E. 
Halpem, Characterization of Ca >+ -dependent 
phospholipase A-, activity dunng zebrafish 
embryogenesisj. Biol. Chem. 274, 19338-19346, 
1999. 

Fire, A., RNA-tnggered gene silencing, Trends 
Genet. 1 5, 358-363, 1999. 

Fisher, S„ and M. E. Halpem, Patterning the 
zebrafish axial skeleton requires early chordin 
function, Nature Genetics 23, 442-446, 1 999. 

Furlow, J. D., and D. D. Brown, In vivo and in 
vitro analysis of the regulation of a transcnption 
factor gene by thyroid hormone during Xenopus 
laevis metamorphosis, Mol. Endocrinol., in press. 



Gall, J. G, M. Bellini, Z. Wu, and C Murphy, 
Assembly of the nuclear transcription and pro- 
cessing machinery: Cajal bodies (coiled bodies) 
and transcnptosomes, Mol. Biol. Cell 10, 4385- 
4402, 1999. 

Gonczy, P., E. Matunis, and S. DiNardo, Bag of 
marbles and benign gonial cell neoplasm act in 
the germ line to restrict proliferation during 
Drosophila spermatogenesis, Development 1 24, 
4361-4371, 1997. 

Halpem, M. E., Diving into Danios, Cell 98,7 \\- 
712, 1999. 

Hendnckson, H. S., E. K. Hendnckson, and S. A. 
Farber, Intramolecularly quenched BODIPY- 
labeled phospholipid analogs in phospholipase 
A 2 and platelet-activating factor acetylhydrolase 
assays and in vivo fluorescence imaging, Anal. 
Biochem., in press. 

Hsieh, J., J. Liu, S. Kostas, C Chang, P. Sternberg, 
and A. Fire, The RING finger/B-Box factor TAM- 
I and a retinoblastoma-like protein LIN-35 
modulate context-dependent gene silencing in 
Caenorhabditis elegans, Genes Dev. 1 5, 2958- 
2970, 1999. 

Huang, H., and D. D. Brown, Overexpression of 
Xenopus laevis growth hormone stimulates 
growth of tadpoles and frogs, Proc. Natl. Acad. 
Sci. USA, in press. 

Huang, H, and D. D. Brown, Prolactin is not a 
juvenile hormone in Xenopus laevis metamor- 
phosis, Proc. Natl. Acad. Sci. USA, in press. 

Huang, H., N. Marsh-Armstrong, and D. D. 
Brown, Metamorphosis is inhibited in transgenic 
Xenopus laevis tadpoles that over-express type 
III deiodinase, Proc. Natl. Acad. So. USA 96, 962- 
967, 1999. 

Hyland, K. M., J. Kingsbury, D. Koshland, and P. 
Hieter, Ctf 1 9p: a novel kinetochore protein in 
Saccharomyces cerevisiae and a potential link 
between the kinetochore and mitotic spindle, 
J. Cell Biol. 1 45, 1 5-28, 1 999. 

Lee, C S„ L Buttitta, N. R May, A. Kispert, and 
C.-M. Fan, SHH-N upregulates Sfrp2 to mediate 
its competitive interaction with WNTI and 
WNT4 in the somitic mesoderm, Development, 
in press. 

Lilly, M., M. de Cuevas, and A. C. Spradling, 
Cyclin A associates with the fusome during 
germline cyst formation in the Drosophila ovary, 
Dev. Biol, in press. 

Marsh-Armstrong, N., H. Huang, D. L Berry, and 
D. D. Brown, Germline transmission of trans- 
genes in Xenopus laevis, Proc. Natl. Acad. Sci. 
USA 96, 14,389-14,393, 1999. 

Marsh-Armstrong, N., H. Huang, B. F. Remo, T 
T Liu, and D. D. Brown, Asymmetric growth 
and development of the Xenopus laevis retina 
during metamorphosis is controlled by type-Ill 
deiodinase, Neuron, in press. 

Matunis, E. L, J. Tran, P. Gonczy, K Caldwell, and 
S. DiNardo, Punt and schnurri regulate a somati- 
cally derived signal that restricts proliferation of 
committed progenitors in the germline, 
Development 124,4383-4391, 1997 

McMahon, J. A., S. Takada, L B. Zimmerman, C- 
M. Fan, R. Harland, and A. P. McMahon, Noggin- 
mediated antagonism of BMP signaling is 
required for growth and patterning of the neural 
tube and somites, Genes Dev. 1 2, 1 438- 1 452, 
1998. 

Megee, P. C, and D. Koshland, Functional assay 
for centromere-associated sister chromatid 
cohesion, Science 285, 254-257, 1 999. 



Michaud, J„ C De Rossi, N. R May, B. Holdener, 
and C.-M. Fan, Amt2 acts as the the dimenza- 
tion partner of Sim I to control the development 
of the hypothalamus, Mechanism of 
Development, in press. 

Miller, D. M., N. Desai, D. Hardin, D. W. Piston, 
G H. Patterson, J. Fleenor, S. Xu, and A. Fire, A 
two-color GFP expression system for C. elegans, 
Biotechniques 26, 9 1 4-92 1 , 1 999. 

Miller-Bertoglio, V., A. Carmany-Rampey, M. 
Furthauer, E. Gonzales, C Thisse, B. Thisse, M. E. 
Halpem, and L Solnica-Krezel, Maternal and 
zygotic activity of the zebrafish 
mercedes/ogon/short tail locus antagonizes BMP 
signaling, Dev. Biol. 214, 72-86, 1999. 

Murphy, T D., and G H. Karpen, Centromeres 
take flight: alpha satellite and the quest for the 
human centromere, Cell 93, 3 1 7-320, 1 998. 

Newmark P. A., and A. Sanchez Alvarado, 
Planarian Regeneration, in Encyclopedia of Life 
Sciences, Nature Publishing Group, London, UK, 
1 999. (http://www.els.net). 

Oegema, K, C Wiese, O. C Martin, R A. 
Milligan, A. Iwamatsu, T Mitchison, and Y. 
Zheng, Charactenzation of two related 
Drosophila 7-tubulin complexes that differ in 
their ability to nucleate microtubules,]. Cell Biol. 
1 44, 721-733, 1999. 

Pepling, M. E., M. de Cuevas, and A. C Spradling, 
Germline cysts: a conserved phase of germ cell 
development? Trends Cell Biol. 9, 257-26 1 , 1 999. 

Sanchez Alvarado, A., The case for comparative 
regeneration: learning from simpler organisms 
how to make new parts from old, e-biomed: 
]. Regenerative Medicine, in press. 

Sanchez Alvarado, A., Regeneration in the meta- 
zoans: why does it happen? BioEssays, in press. 

Sanchez Alvarado, A., and P. A. Newmark 
Double-stranded RNA specifically disrupts gene 
expression dunng planarian regeneration, Proc. 
Natl. Acad. Sci. USA 96, 5049-5054, 1 999. 

Skibbens, R V., L B Corson, D. Koshland, and P. 
Hieter, Ctf7p is essential for sister chromatid 
cohesion and links mitotic chromosome struc- 
ture to the DNA replication machinery, Genes 
Dev. 1 3, 307-319, 1999. 

Spradling, A. C, ORC-binding, gene amplifica- 
tion, and the nature of metazoan replication ori- 
gins, Genes Dev. 13, 2619-2623, 1999. 

Spradling, A. C, D. Stem, A. Beaton, E. J. Rhem, 
N. Mozden A. deGrey, and G. M. Rubin, The 
BDGP gene disruption project: single P element 
insertions mutating 25?-6 of vital Drosophila 
genes, Genetics 153, 135-177, 1999. 

Tabara, H., M. Sarkissian, W. Kelly, J. Fleenor, A. 
Grishok L. Timmons, A. Fire, and C. Mello, The 
rde- 1 gene, RNA interference, and transposon 
silencing in C. elegans, Cell 99, 123-1 32, 1999. 

Wiese, C, and Y. Zheng, 7-tubulin complexes 
and their interaction with microtubule organizing 
centers, Curr. Opin. Structural Biol. 9, 250-259, 
1999. 

Wilde, A., and Y. Zheng, Stimulation of micro- 
tubule aster formation and spindle assembly in 
Xenopus egg extracts by the small GTPase Ran, 
Science 284, 1359-1362, 1999. 

Williams, B. C, T D. Murphy, M. L Goldberg, 
and G H. Karpen, Neocentromere activity of 
structurally acentric minichromosomes in 
Drosophila, Nature Genetics 1 8, 30-37, 1 998. 

Zhang, J.-M., L Chen, M. Krause, A. Fire, and B. 
M. Paterson, Evolutionary conservation of MyoD 
function and differential utilization of E proteins, 
Dev. Biol. 208, 465-472, 1999. 



The Observatories 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



THE DIRECTOR'S INTRODUCTION 




Fig. I. This is a model of the Inamori Magellan Areal Camera and Spectrograph (IMACS) to be mounted on the 
Magellan I telescope. When complete, this wide-field instrument will be used in high-redshift studies of the universe. 



The Postdoctoral Program 

Qhe research of the senior staff of the 
Observatories is described in the pages that follow. 
However, it is only part of the scientific activity on 
Santa Barbara Street. Another key component is 
the postdoctoral program. This program is the 
principal way in which the Observatories con- 
tribute to the education of young astronomers; but 
it does more than that. The constant flow of new 
faces and new ideas through the Observatories 
makes a significant contribution to the intellectual 
life of the department. It is a contribution to the 
future as well as to the present: the majority of 
Observatories Staff Members first came to Santa 
Barbara Street as postdocs. 

There are usually about a dozen postdoctoral fel- 
lows and associates at the Observatories: three 
Carnegie Fellows, funded by the institution; up to 



three Hubble Fellows, funded by the Space 
Telescope Science Institute; and a half dozen post- 
doctoral associates, funded by grants to individual 
researchers. Unlike those in laboratory sciences 
such as biology, many astronomy postdocs are free 
agents. The Carnegie and Hubble Fellows, in par- 
ticular, are completely independent researchers, 
doing the science they want to do in the way they 
want to do it. This is a great challenge as well as a 
great opportunity for a still-maturing scientist, 
and our fellows almost invariably make the most 
of the opportunity. Indeed, former Observatories 
postdocs have been extremely successful in their 
later careers and populate many of the leading 
astronomy positions. 

Carnegie postdocs work on a wide variety of prob- 
lems either on their own or in collaboration with 
Observatories staff. A few examples follow. 



CARNEGIE INSTITUTIO 



)N 



YEAR BOOK p8~pp 



Carnegie Fellow Jason Prochaska uses the light 
from extremely distant quasi-stellar objects (QSOs) 
to probe the contents of the universe. The view of 
the universe normally provided by telescopes, 
whether optical, radio, or x-ray, is a biased one, 
because it is dominated by those objects that are 
copious emitters of optical, radio, or x-radiation. 
QSO light tells us about QSOs, of course, but it is 
also an unbiased probe of all the space through 
which the light travels on the way to our telescope. 
This probe reveals a very different universe, filled 
with gas, which leaves telltale absorption lines in the 
QSO spectrum. The challenge is to relate the 
objects detected by this technique to the luminous 
objects seen in usual observations. The strongest 
absorption lines are believed to be produced in the 
disks of young galaxies, but proof of this has been 
hard to find. Prochaska has used very high resolu- 
tion spectroscopy of these systems to demonstrate 
that they are in ordered rotation, consistent with the 
hypothesis that they are indeed disk galaxies or, at 
the very least, rotating collapsing protogalaxies. 

Another take on a somewhat later stage in galaxy 
evolution is provided by Carnegie Fellow Scott 
Trager's study of elliptical galaxies and spiral 
galaxy bulges. These are both spheroidal systems 
thought to be products of the earliest phase of 
galaxy formation. The spectrum of a collection of 
young (less than 1 billion years old) stars differs 
markedly from that of a collection of old (10 bil- 
lion years old) stars. However, the differences 
between the spectra of 5 and 10-billion-year-old 
stellar populations are quite subtle. It is these small 
differences that Trager searches for. He has found 
that the bulges of spiral galaxies with big bulges 
(such as the Andromeda galaxy) are quite old, hav- 
ing formed very early in the history of the uni- 
verse, while the bulges of at least some disk galax- 
ies with small bulges are quite young — no older 
than their own disks. This suggests that the two 
types of spiral galaxies form in reverse order: the 
large bulges may form as elliptical galaxies and 
then accrete their disks, while small bulges may 
form from the disks themselves. 

One can directly study the earlier history of elliptical 
galaxies by observing them at high redshifts. As Pat 
McCarthy and Eric Persson describe in following 




Fig. 2. The Andromeda galaxy M3 I 



pages, high-redshift ellipticals are very red, and are 
most easily discovered using a combination of visible 
light and infrared observations. Persson, McCarthy, 
and Hubble Fellow Ron Marzke are leading 
Carnegie's participation in a collaborative project 
with the Institute of Astronomy at Cambridge 
University. This project mates an infrared detector 
system from Cambridge with an optical system pro- 
duced by Persson's infrared instrumentation group 
to form the most powerful infrared survey instru- 
ment extant. Mounted on the du Pont telescope at 
Las Campanas, this instrument is producing the 
most extensive deep-infrared survey yet obtained. 
When combined with optical observations, these 
data will form the basis for Magellan telescope stud- 
ies of early elliptical and starburst galaxies, and the 
evolution of clustering in the universe. 

Department News 

The Observatories continue to grow as scientific, 
technical, and support staff are added. Most of the 
growth has been driven by Magellan's need for 
instrument builders, programmers, operations 
staff, etc. Finding yet another unused basement 
space that can be turned into new offices has 



:arnegie institution 



YEAR BOOK p8~pp 









<j 


m m fli iL 
George Preston 


• S-'i 




become a constant pre- 
occupation. Two new 
Staff Members were 
appointed during the 
past year to replace 
Allan Sandage and 
George Preston, who 
are both retiring. John 
Mulchaey received his 
Ph.D. in 1994 from the 
University of Maryland 
and has been a fellow at 
the Observatories ever 
since. He is a leader in 
the study of groups of 
galaxies, the most com- 
mon but most neglected 
galactic environment. 
Mulchaey's work has 
revealed surprising new 
properties of groups of 
galaxies, including some 
in which all the galaxies 
have merged into one giant object. 

Michael Rauch received his Ph.D. in 1993 from 
Cambridge University. He worked at the 
Observatories and at Caltech, and is now on the 
staff of the European Southern Observatory. Dr. 
Rauch's field is absorption-line QSOs. This is an 
area of long-standing importance for understand- 
ing the contents and structure of the universe; it 
has undergone a significant flowering in recent 
years due in significant part to Dr. Rauch's work. 
Unlike Prochaska's work in the same area, Rauch's 
focuses on the lowest-density systems, which are 
thought to be primordial gas clouds that have not 
yet condensed into bound systems. 

Dr. Luis Ho began a five-year appointment as Staff 
Associate. Dr. Ho's principal interest is the inci- 
dence and properties of black holes in the centers 
of galaxies. Such black holes manifest themselves 
in two ways: by their gravitational pull on the 
surrounding stars, and by powering active galactic 
nuclei (AGNs). He has shown that such AGNs 
are much more prevalent than previously thought, 
suggesting that most, if not all, large galaxies 
harbor a supermassive black hole in their centers. 



Another very welcome addition is Mark Phillips, 
who was appointed Associate Director of the Las 
Campanas Observatory. Dr. Phillips was a long- 
time staff member and former Associate Director 
of the Cerro Tololo Inter- American Observatory 
(CTIO) in La Serena, Chile, and he is a leading 
authority on supernovae. His calibration of the 
luminosities of supernovae is central to recent 
work using them as cosmological probes. He has 
moved across the street from CTIO to El Pino to 
continue his supernova research, and to work with 
LCO director Miguel Roth to manage the 
increasingly complex Las Campanas operation. 

The Magellan Project 

The enclosure and mount of the Magellan I tele- 
scope are essentially complete. Only minor addi- 
tions to the telescope control system software 
remain. Work on the aluminization system con- 
tinues; it is expected to be ready for a first coating 
of the primary mirror in the spring of 2000. 
Figuring was completed for the primary mirror at 
the Steward Observatory Mirror Laboratory 
(SOML) and for the f/11 secondary mirror at 
Contraves. Both mirrors are superb, meeting or 
exceeding specifications at all levels. 
Unfortunately, slow progress on the f/15 silicon 
carbine secondary mirror has forced a suspension 
of that effort. By mid- 1999, the primary mirror 
support system (also being produced by SOML) 
was nearing completion, and the mirror and mir- 
ror cell were shipped to Chile in the fall of 1999. 

Meanwhile, erection of the Magellan II enclosure 
has reached the halfway point. All steel for the fixed 
lower part of the enclosure is in place, but comple- 
tion of the rotating upper half awaits delivery of the 
remaining steel from the fabricator in Spain. 
Assembly of the telescope mount is well under way 
at L&F Industries in Huntington Park, California. 
The Magellan II primary mirror was successfully 
cast in the fall of 1998 at SOML, and work on the 
back side of the mirror is nearly complete. 

The IMACS spectrograph for Magellan I passed 
its preliminary design review in April 1999. 
Fabrication of the optics for the collimator and 
long camera, and fabrication of mechanical com- 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 




Fig. 3. The Magellan Project's facilities at Las Campanas 
include the dome for the first telescope, as shown in the 
foreground. The enclosure for the Magellan II telescope is 
under construction in the background. 



ponents should begin by the end of 1999. The 
mechanical design of the Kyocera Echelle 
Spectrograph is also near completion. Design 
work on the DDI infrared spectrograph continues, 
but progress has been slowed by the need to 
complete the infrared camera, described earlier, 
for the du Pont telescope. Most of the glass for 
the optics has been delivered, and polishing of 
elements should begin in the latter half of 1999. 

— Augustus Oemler, Jr. 

Alan Dressler 

One of the great mysteries of modern astronomy is 
the nature, amount, and distribution of the dark 
matter that dominates the universe. A principal 
direction of Alan Dressler's research has been to 
try to map the distribution of dark matter on cos- 
mic scales by tracing its presence through the grav- 





itational pull it exerts 
on galaxies. By finding 
the "peculiar velocities" 
of thousands of galax- 
ies in our cosmic 
neighborhood, 
Dressier and his col- 
leagues discovered a 
huge concentration of 
dark matter, which 
they named the Great 
Attractor. 



This year marked a milestone in the study. Data 
from the new technique called surface brightness 
fluctuations have at last been brought to bear on 
the problem. Many of the new measurements were 
made with the du Pont CCD cameras and relied 
on the excellent observing conditions at Las 
Campanas Observatory. The data took almost 10 
years to obtain, and provide the most accurate 
peculiar velocities to date. In three new papers, 
Dressier and his colleagues John Tonry of the 
University of Hawaii, John Blakeslee of Caltech, 
and Ed Ajhar of the National Optical Astronomy 
Observatories confirm the existence of the Great 
Attractor. Additionally, the researchers were able 
to see, for the first time, the weaker flows of galax- 
ies into much smaller mass concentrations, as well 
as the flows away from voids — places where few 
galaxies are seen and the corresponding mass den- 
sity is thought to be very low. The higher resolu- 
tion and sensitivity of these new dark-matter maps 
will allow a much better determination of the 
extent to which the galaxy distribution traces the 
dark matter. This information is crucial to inter- 
preting the large-scale structure of the universe as 
mapped by galaxies, and to understanding the role 
of dark matter in galaxy formation. 

Another theme of Dressler's research involves the 
question of how galaxies formed and evolved over 
cosmic time. Astronomers have the unique ability to 
look back in time as they look far out into space. 
With their colleagues, Dressier and Gus Oemler 
have been using large ground-based telescopes and 
the Hubble Space Telescope to observe distant 
galaxies to determine their properties at earlier 



:arnegie institution 



YEAR BOOK p8~pp 



times. This collaboration, known as the MORPHS 
Project, has produced two major papers this year. 
The papers describe the connection between galaxy 
morphology (structure) and star-formation history 
in galaxies seen as they were 5 billion years ago. 
Among the conclusions of this work is that bursts 
of star formation were much more common in 
galaxies at that epoch, in contrast to the steadier 
star-formation rate characteristic of galaxies today. 
Additionally, the scientists found that because these 
starbursts were often shrouded by dust, their impor- 
tance had been underestimated in earlier work. 

The MORPHS study concluded that elliptical 
galaxies — the spheroidal systems that are most 
common in regions of high galaxy density — are 
generally old, nearly as old as the universe, but that 
over the last 5 billion years many spiral galaxies — 
disk galaxies with ongoing star formation — have 
been transformed to a dormant kind of disk galaxy 
calle'd an SO. The specific mechanisms responsible 
for this change remain elusive and are still under 
study by the group. 

Over the next two years Dressier will devote consid- 
erable effort as principal investigator of the IMACS 
instrument, a sensitive multiobject spectrograph and 
camera with a very wide field. When mated with 
the new Magellan I telescope, this instrumentation 
will open new territory in the high-redshift universe 
for Dressier and colleagues to study the evolution of 
galaxies with lookback time. 

Wendy Freedman 

Big Bang cosmology makes a number of predic- 
tions, one of which is the expansion of the uni- 
verse. However, the Big Bang theory does not pre- 
dict how fast that expansion is, or what the density 
of matter in the universe is. These quantities, 
which describe the fundamental, global nature of 
the universe, must be determined by observations. 
For the past 15 years, Wendy Freedman has been 
working on a project to measure the Hubble con- 
stant — the rate of the expansion of the universe. 
The Hubble constant, when combined with a 
value for the average density of mass/energy in the 
universe, yields a measure of the universe's age. 




Fig. 5. The galaxy Messier 100 is shown here as imaged by 
the Hubble Space Telescope. 



Freedman is a principal investigator, with Robert 
Kennicutt of the University of Arizona and Jeremy 
Mould of the Australian National University, of a 
group of 27 astronomers located across the U.S. 
and in Canada, Great Britain, and Australia. For 
the past eight years, the group has been using the 
Hubble Space Telescope (HST) to improve accu- 
racy in the measurement of the Hubble constant. 
Most of the effort in the HST project has been 
aimed at measuring the distances to galaxies using 
a relation between the period and luminosity of 
Cepheid variables — pulsating stars that are used 
to measure distance. Turbulence in the Earth's 
atmosphere makes these measurements impossible 
from the ground for all 
but the nearest galax- 
ies. As part of the Key 
Project, the team mea- 
sured Cepheid dis- 
tances to 18 galaxies 
and discovered about 
750 Cepheid variables. 
Even with the HST, 
however, the range for 
discovery of Cepheids 
is limited to distances 
less than about 80 mil- 
lion light-years. To measure the Hubble constant, 
it is necessary to measure farther out. To do so, the 
scientists tied the Cepheid distances into other 
methods that are based on more luminous objects 
visible at greater distances, such as luminous 
supernovae, and spiral and elliptical galaxies. 




G?j3fe 



Wendy Freedman 



o 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



Using four independent methods, all calibrated by 
the new HST Cepheid distances, Freedman and 
collaborators found a value of the Hubble constant 
of 71 km/sec/megaparsec with a total uncertainty 
of 10%. The current best estimates for the average 
density of matter in the universe suggest a lower 
value than was previously thought; it is now 
believed to be about one quarter of the so-called 
critical density. This new value, when coupled 
with a Hubble constant of 71, yields a universe 
that is about 12 billion years old. This age agrees 
well with recent results from the Hipparcos satel- 
lite, which give very similar ages for the oldest 
stars in our galaxy. 

Several years ago, the preferred theoretical models 
suggested that we live in a critical-density uni- 
verse. Under that scenario, values of the Hubble 
constant of 70 or 80 led to a universe that is 8 or 9 
billion years old. This result was in apparent con- 
flict with the then-current estimates for the ages of 
globular clusters at 15 billion years. This paradox 
is very simply resolved, however, if we live in a 
low-matter density universe. We might still live in 
a universe at critical density (if there is another 
component of energy, perhaps due to the so-called 
cosmological constant), but the new Hubble con- 
stant results do not require this possibility. 

Luis Ho 

Luis Ho's arrival at the Observatories last fall 
coincided with a particularly eventful time, the 
birth of his son Hansun. After the inevitably hec- 
tic period of moving across the country, the transi- 
tion to LA life was smooth. It did not take long 
for his wife, Sandra, and daughter Mya to appreci- 
ate the virtues of sunny southern California. 

Ho's work primarily focuses on two themes: physi- 
cal processes in galactic nuclei and the properties 
of young, massive extragalactic star clusters. The 
study of the central regions of nearby galaxies has 
entered an exciting era with the advent of powerful 
new instruments such as the Space Telescope 
Imaging Spectrograph (STIS) aboard the Hubble 
Space Telescope (HST). Ho and his collaborators 
are using STIS to obtain high-resolution, spatially 




resolved spectra of the 
nuclear regions of a 
large sample of galax- 
ies. These data yield 
kinematic measure- 
ments of gas and stars, 
information that can 
constrain the central 
mass distribution in an 
unprecedentedly large 
number of galaxies, 
and thus verify the 

existence of massive black holes. The same data 
also give exquisite spectral information that allows 
Ho to probe the stellar population and gas proper- 
ties on spatial scales of a few parsecs. Ho is also 
taking advantage of the fantastic imaging capabili- 
ty of the HST to study the structure of spiral 
galaxies' bulges. The HST data reveal a bewilder- 
ing array of fine structures previously unknown 
from ground-based images such as spiral arms, 
dust lanes, star clusters, and compact nuclei. 

In an effort to better understand the physics of 
low-luminosity, active galactic nuclei (AGNs) — 
common in most large nearby galaxies — Ho has ini- 
tiated a suite of observational programs using the 
HST, x-ray satellites, and ground-based radio tele- 
scopes. The goal of these programs is the same: to 
characterize the properties of nearby galactic nuclei 
at many wavelengths. These nuclei have been virtu- 
ally unstudied because of their extreme faintness. 
The initial results are startling: the broadband spec- 
tral energy distributions of low-luminosity AGNs 
look remarkably different from those of the tradi- 
tionally studied, high-power AGNs, such as Seyfert 
nuclei and quasars. This information strongly sug- 
gests a difference in the process by which the central 
black holes accrete matter in the two classes of 
AGNs; a suspicion confirmed by theoretical calcu- 
lations made with colleagues at Harvard. 

Ho recently started work in two rather different 
directions. With Mark Phillips and collaborators 
at Cerro Tololo Inter- American Observatory, Ho 
joined an ambitious study, which employs a 
large-format camera to monitor a large number of 
galaxies with redshifts up to 0.1. The primary 
objective is to search for local supernovae and to 



c/ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



characterize their properties as a function of their 
environment. Another objective is to search for 
flashes of light from galactic nuclei. These flashes 
are a unique signature predicted from the tidal dis- 
ruption of stars caused by massive black holes, 
which are believed to be ubiquitous in galactic 
nuclei. With John Mulchaey, Gus Oemler, and 
Steve Shectman, Ho is also using the du Pont tele- 
scope at Las Campanas to obtain morphological 
data and integrated optical spectra of a large sam- 
ple of "local" (redshifts less than 0.1) galaxies. The 
intention is to assemble a library of reference data 
to serve as a useful present-epoch benchmark for 
future optical studies of more distant galaxies. 

William Kunkel 

Kunkel's research has focused on the internal 
dynamics of the Large and Small Magellanic 
Clouds (moderate -size satellites of the Milky Way) 
using observations from the motion of carbon stars. 
Carbon stars were selected as test particles because 
of their age: they are old enough to have completely 
decoupled from the motions of the gas, and no 
longer retain traces from the earliest phases of galaxy 
formation. Because of these features, carbon star 
motion is expected to represent the median dynamic 
behavior under gravity alone. Up to now, 
astronomers have assumed that the motion of gas is 
a reliable tracer of gravitational forces. Kunkel, in 
collaboration with Serge Demers of the University 
of Montreal and Mike Irwin of the Royal 
Greenwich Observatory, discovered significant devi- 
ations between the stellar and gas motions in both 
Magellanic Clouds. The data acquisition phase of 
the study was completed in 1998, and 1999 has 
been dedicated to the final interpretive exercise. 

The Magellanic Clouds are satellites on highly 
elongated orbits. They receive episodic impulses of 
mechanical energy generated by tidal forces each 
time they approach one another or the Milky 
Way. These tidal impulses offer an opportunity to 
"tweak" the behavior of gravity in a known way, 
facilitating specific tests that are easily replicated 
in a computer simulation. Comparison of the 
behavior seen in the numerical simulation with 
that observed in the carbon stars reveals serious 



difficulties with otherwise well-established tradi- 
tion. The most serious problem is the distribution 
of dark matter. According to established lore, it is 
expected to follow gravitational forces exclusively, 
yet somehow sustain a spatial distribution different 
from that of observed matter, which congregates at 
the centers of dark matter complexes. Other 
conundrums addressed include the surprise that 
unlike carbon stars in the Milky Way, carbon stars 
in the Magellanic Clouds are found far from cur- 
rent sites of star formation. Large amounts of 
energy (and traditionally, a very long time) are 
required to carry carbon stars from their birth 
locations to where they are seen today. 
Mechanisms are thus needed to "stir things up," 
and tidal impulses are the outstanding candidates. 

Since numerical simulations have clarified the 
global dynamic picture of gravitational processes in 
the Magellanic Clouds, the results of the present 
study indicate that significant nongravitational 
forces are acting on the gaseous components of the 
local satellites. Eventually, the significance of these 
findings is expected to impact how reliably one 
can trust the information about the spins in small 
galaxies, which is inferred from observations of 
rotating gas disks. More important, the findings 
will affect inferences about the distribution of 
gravitational potentials from such observations. 

In the future, Kunkel intends to explore the 
gas/stars discrepancies in the nearest of the more 
remote galaxies: IC1613 and NGC6822. These are 
examples of systems experiencing occasional tidal 
impulses, and NGC3109 is one in which such 
impulses (stirring spoons!) are expected to be absent. 

Patrick McCarthy 

The stars that constitute the bulk of the mass of 
galaxies emit most of their luminous energy at wave- 
lengths longer than 0.5 microns. These cool, giant 
stars have masses comparable to that of the Sun and 
lifetimes of billions of years. At large distances, the 
cosmological redshift has shifted this radiation to 
the near-infrared (IR). Most surveys of high-red- 
shift galaxies have been confined to visible wave- 
lengths, and thus sample ultraviolet (UV) photons 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



emitted at the source. The emitted and observed 
wavelengths are related by Emitted = Xobserved/(l + z), 
where z is the redshift. The ultraviolet luminosity of 
galaxies is often dominated by a small population of 
massive stars that produce 100 to 1,000 times more 
luminosity per unit mass than stars like the Sun, but 
have lifetimes that are measured in millions rather 
than billions of years. The UV luminosities 
of galaxies thus reflect their present star formation 
rates, while near-infrared luminosities are a far 
better tracer of the total stellar mass. 

For the past few years Patrick McCarthy and 
colleagues have been applying near-infrared 
techniques, from Las Campanas and from orbit, 
to study faint and distant galaxies. Together with 
Staff Member Eric Persson and Hubble Fellow 
Ron Marzke, McCarthy has embarked on an ambi- 
tious survey of faint galaxies in the near-infrared. 
Using a unique camera containing a mosaic of four 
large near-IR detectors, the scientists are surveying 
an area of the sky four and a half times the area of 
the full Moon. This survey will yield a sample of 
between 2,000 and 4,000 old galaxies at large red- 
shifts, and will allow the astronomers to precisely 
measure their spatial clustering — an important clue 
in understanding the growth of density irregularities 
in the early universe. 




Fig. 6. This is a near-infrared and optical image of a cluster of 
galaxies with a redshift of nearly I . The picture is a composite 
of images at 0.5, 0.8, and 1 .6 microns. Old galaxies are 
strongly clustered around the central object, a luminous 
radio source. These data were obtained with the du Pont 
telescope at Las Campanas. 



Spectroscopy in the near-infrared offers a new win- 
dow on galaxies at large redshifts. McCarthy and 
postdoctoral associate Lin Yan have used the near- 
IR spectrometer on board the Hubble Space 
Telescope to measure the star formation rates of 
galaxies with redshifts between 1 and 2. Yan and 
others find that the star formation rate at a redshift 
of 1.5 is 17 times larger than the present rate. This 
high rate of star formation is a factor of two to three 
times greater than the rate derived from ultraviolet 
measurements and implies that roughly 50% of the 
stars in the present universe were formed as recently 
as 5 billion years ago. This is in stark contrast to the 
very inactive and old galaxies that are the targets of 
the survey described above. These results highlight 
the fact that galaxy evolution is not a uniform or 
homogeneous process. The life history of a galaxy is 
greatly influenced by the environment in which it 
begins. Some reach maturity early in the history of 
the universe, while others lie dormant until some 
stimulus drives the conversion of gas into stars. 

Andrew Mc William 

Andrew Mc William's research focuses on nucleo- 
genesis and galactic chemical evolution. His goal is 
to understand where and how the elements were 
produced by studying the composition of very old 
stars and stars born in different environments. 

Stars produce most of the elements in the universe; 
supernovae (SNe) are particularly important sources. 
Theoretical models of SNe and other astrophysical 
enrichment events are very crude and require obser- 
vational constraint. Stars of low mass are very long- 
lived and span the age of our galaxy. Such fossil stars 
can be used to trace the history of chemical evolu- 
tion. In general, the oldest stars are the most metal- 
poor because fewer supernovae had occurred before 
the very early epoch when the stars formed. 

Most stars contain the chemical signatures of 
many supernovae (over 100 million SNe have 
occurred in our galaxy), so the amplitude of abun- 
dance variations from individual SNe are usually 
insignificant. The abundance variations of individ- 
ual SNe are more evident in stars composed of 
ejecta from only one or a few supernovae. These 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



stars are very metal poor and very rare. They show 
large abundance variations, some with detectable 
amounts of the radioactive element thorium, 
which can be used to measure the age of the 
galaxy. In 1998 and 1999, there were two searches 
for extremely metal-poor stars. Staff Members 
George Preston, Ian Thompson, and McWilliam 
conducted the first search toward the galactic 
bulge; the second was done by McWilliam in 
metal-poor dwarf spheroidal galaxies (dSph). At 
present, stars with metal abundances near 10 3 
those of the Sun are confirmed, and two candidates 
near abundances of 10" 4 solar have been identified. 

McWilliam and Director Emeritus Leonard Searle 
have produced a model of stochastic chemical 
evolution to understand the 300-fold dispersion of 
strontium abundance in extremely metal-poor stars. 
The model assumes a distribution of supernovae 
Sr/Fe ratios from the most metal-poor stars; the 
ratios are selected randomly from this distribution 
and then mixed. Figure 7 shows predicted and 
observed abundances; note the excellent fit. The 
unusual position of two stars with metal abundances 
near 10" 4 solar constrain the model, and suggest that 
stars composed of material from individual super- 
novae have metal abundances near 10~ 32 of the Sun. 




[Fe/H] 



Fig. 7. The figure shows the observed abundances of Sr/Fe 
(crosses) compared with predictions. The region bounded by 
the dotted lines indicates the stars used to set the initial dis- 
tribution in Sr/Fe ratio, while solid lines show the predicted 
evolution (5, 15, 85 and 95 percentiles) of Sr/Fe. Filled circles 
indicate the predicted evolution of the median Sr/Fe ratio. 



The compositions of other environments permit 
tests of the chemical evolution paradigm. To this 
end, McWilliam and Tammy Smecker-Hane of 
UCI used the Keck telescope to acquire spectra of 
red giant stars in the Sagittarius dSph. The results 
show a large spread in metallicity and unusual 
abundances of O, Mg, Si, Ca, Al, and Na. One 
explanation for this spread is that the Sagittarius 
dSph experienced an extended quiescent period 
of several billion years followed by a burst of star 
formation, with the composition of the metal-rich 
population coming from metal-poor (10~ 2 of solar) 
type la supernovae. 

McWilliam acquired CTIO spectra of 70 galactic- 
bulge red giants, and 12 spectra using the Keck I 
with Mike Rich of UCLA. The scientists found 
unusual enhancements of O and Eu at solar metal- 
licity. These elements are mostly made by type II 
SNe (with short progenitor lifetimes), which indi- 
cates a rapid formation timescale for the galactic 
bulge on the order of one billion years. It is 
remarkable that the bulge reached solar metallicity 
so quickly. 

Eric Persson 

Recent rapid improvements in the quality and size 
of near-infrared imaging array detectors have led to 
significant advances in several areas of astronomy. 
Persson is leading a group of Carnegie scientists 
and engineers in the development of telescope 
instrumentation that exploits these new devices. 
They have built one wide-field survey camera for 
the du Pont 2.5-m telescope, and are currently 
designing infrared instruments for the two Magellan 
6.5-m telescopes at Las Campanas. The group has 
started a number of projects with the new camera, 
the most demanding of which concerns the discov- 
ery, measurement, and follow-up spectroscopy on 
distant galaxies — particularly those whose properties 
and remote distances are such that they can only be 
studied at near-infrared wavelengths. 

Until recently, it has been difficult to find signifi- 
cant numbers of these galaxies. This is solely due to 
technical reasons: detectors and cameras have not 
been large enough to cover large areas of sky. For 
the next several years, the Persson group will survey 



CARNEGIE INSTITUTIO 



)N 



page JO I YEARBOOK^- 99 



one square degree of sky to find and accurately 
measure the brightnesses of thousands of high-red- 
shift galaxies. It will then be possible to estimate 
their distances and intrinsic luminosities, and study 
their clustering tendencies in space. Another objec- 
tive of the survey is to discover large numbers of 
abnormal galaxies that exist at great distances. 
Persson and others have serendipitously found dis- 
tant galaxies that emit virtually all of their energy in 
the infrared range. While these galaxies are fairly 
easy to detect in the near-infrared, they can be 
completely invisible in the deepest optical searches. 
They are so rare that prohibitively large areas of 
sky must be surveyed to find new examples. 
Preliminary spectroscopic evidence on a handful of 
such galaxies indicates a heterogeneous population: 
some are likely to be intense star-forming galaxies 
buried within optically opaque dust clouds, while 
others appear to be passively evolving objects in 
which star formation ceased several billion years 
before. These objects will be prime targets for 
Magellan instrumentation. 

For the past 70 years, astronomers have tried to 
determine the distance scale of the universe. 
Persson and Carnegie collaborators hope to 
advance this field by studying newly found type la 
supernovae. These objects are widely believed to 
provide the key to understanding how the 
timescale, geometry, and mass content of the uni- 
verse can be reconciled within the framework of 
general relativity. Type la supernovae are stellar 
explosion events, which appear to follow a 
well-defined development of brightness over time 
as they rise to a maximum luminosity and then 
decline. Because the intrinsic luminosities of super- 
novae at maximum light are essentially the same 
event-to-event, relative distances to their remote 
counterparts, observed in host galaxies billions of 
light years away, can be determined in a fairly 
straightforward manner. However, it is vital to be 
certain that the local supernova events are physically 
the same as their distant counterparts. At 
near-infrared wavelengths, type la supernova light 
curves appear to be very similar to one another. 
With the new infrared camera on the 2.5-m tele- 
scope, Persson's group will monitor the many new 
supernovae found each year and create a database 
that will calibrate distances to the remote objects. 




Mark Phillips 

Supernovae are among the most violent and ener- 
getic phenomena observed in the universe. The high 
temperatures reached inside a supernova explosion 
energize a wide range of nuclear reactions, which 
synthesize new heavy elements. These elements are 
then dispersed into interstellar space along with the 
products of the fusion reactions that originally pow- 
ered the progenitor star. 
The shock wave pro- 
duced by a supernova 
can trigger the collapse 
of neighboring molecu- 
lar clouds, leading to 
the formation of new 
stars. Some of these 
new stars will eventually 
end their lives as super- 
novae. This alternating 
cycle of the birth and 
death of stars has led to 

the steady heavy-element enrichment of the uni- 
verse, making possible life as we know it on Earth. 

Because of their extreme brightness at maximum, 
supernovae are potentially powerful "standard can- 
dles" for probing the geometry and expansion of 
the universe. The type la supernovae, which are 
thought to be the complete thermonuclear disrup- 
tion of a small, very dense stellar remnant called a 
white dwarf, are especially attractive candidates. 
They display a high degree of homogeneity and 
can be observed to very great distances because of 
their immense luminosities at maximum light (up 
to 10 billion times that of the Sun). 

Since the early 1980s, Mark Phillips has carried 
out observations of supernovae to understand in 
more detail the nature of these events and to cali- 
brate their usage as standard candles. Several years 
ago, Phillips showed that the peak luminosities 
of the type la supernovae were not identical, but 
that these objects could still be used as standard 
candles because the luminosity of each event was 
correlated with the rate of decline from maximum 
light, which could be measured independently. 
Calibrating the exact dependence of this correla- 
tion has required obtaining precise light curves for 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8—pp page JI 



a large number of supernovae. In addition, a 
method had to be devised for deriving the absorp- 
tion of the light of each supernova due to dust in 
its "host" galaxy. Phillips and his collaborators 
developed a technique for measuring this absorp- 
tion, which then allowed them to correct the 
observed peak brightness of the supernova for this 
"missing" light. From this work, Phillips and his 
collaborators have been able to determine a value 
of the Hubble constant (a measure of the present 
rate of expansion of the universe) of approximately 
65 km/sec/megaparsec. 

Phillips has also been heavily involved in the 
effort to detect very distant supernovae. Using the 
Hubble Space Telescope, he and his collaborators 
recently demonstrated the feasibility of detecting 
supernovae at redshifts as great as z = 1.5, when the 
universe was only one- third its present age. In the 
future, it should be possible to probe the star-for- 
mation history of the universe by carrying out com- 
prehensive searches for such distant supernovae. 

Phillips and his collaborators are also using 
very distant type la supernovae to measure the 
expansion rate of the universe at earlier epochs. 
These observations have led to a surprising result: 
we seem to be living in an accelerating universe. 
Although unexpected, this finding has a certain 
attraction since it leads to an age of the universe 
that is consistent with the ages of the oldest stars 
in our galaxy. Nevertheless, these observations are 
sensitive to the possibility that the luminosities of 
the type la supernovae have evolved with time. 
During the next few years, Phillips plans to focus 
his research on testing the latter prospect through 




Fig. 8. These are images of the z = 0.95 galaxy 3-22 1 .0 in the 
Hubble Deep Field. The first epoch image was taken in 
December 1995; the second epoch image was obtained two 
years later in December 1997. Note the appearance of a 
supernova in the second epoch image. 



systematic observations of supernovae at a variety 
of redshifts and environments. 

George Preston 

George Preston, with Carnegie collaborators 
Andrew McWilliam, Stephen Shectman, and Ian 
Thompson, is engaged in the astronomical equiva- 
lent of looking for radium in pitchblende. He is 
searching for extremely rare astronomical relics — 
the earliest generations of stars formed in the Milky 
Way. The signature of these relics is the virtual 
absence of elements heavier than helium in their 
atmospheres. They are identified by wholesale 
examination of spectra from the myriad of stars 
that inhabit the dense central bulge of our galaxy. 

The very first generation of stars was made of Big 
Bang material, that is, hydrogen and helium with a 
trace of lithium. All the heavier elements have been 
produced by nucleosynthesis in massive stars that 
explode as supernovae after they exhaust their fuel 
supplies. Debris from the first supernova explosions 
polluted the galactic gas. Out of this gas, future 
generations of stars formed. Continual repetition 
of this process for the past 15 billion years or so has 
gradually increased the heavy-element content of 
the universe to its present level. 

The second generation of stars contained no more 
than one-tenth of a percent of the metal content of 
the Sun. These stars comprise no more than one- 
tenth of a percent of the stars formed since the 
beginning of time. These are the objects sought by 
the Carnegie team. Because they are made of gas 
enriched by single, or at most a few, supernova 
events, their chemical compositions tell what particu- 
lar combinations of heavy elements are produced in 
various supernova explosions. What little was learned 
about the "yields" of supernovae from an earlier 
Carnegie survey reveals that these explosions are not 
all alike. Their debris exhibits enormous variety, 
which means that the accumulation of all the chemi- 
cal elements to their present levels is a complex 
process of which we have only a dim comprehension. 

The Carnegie team conducted the first phase of 
their new search for extremely metal-poor stars in 



CARNEGIE INSTITUTION 



page 72 YEAR BOOK p8~pp 





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Fig. 9. This image shows spectra (plots of light intensity 
versus color progressing from blue to red) for two stars. 
The spectrum of the Sun with present-day levels of heavy 
elements (above) looks like a picket fence. The spectrum of 
CD -38:245, a star of similar temperature but with 10,000 
times fewer heavy elements (below), looks almost feature- 
less. Such stars are rare but unmistakable. 



1997 and 1998 at Las Campanas using the Swope 
and du Pont telescopes. They performed CCD 
photometry in 50 star fields in the galactic bulge 
with a special set of filters that identify metal-poor 
candidates among the 100,000 red giants present. 
Unfortunately, the metal-poor signature can be 
forged by a few other exotic groups of stars — those 
with very high velocities, powerful chromospheric 
emission, or large carbon excesses. GRISM 1 
spectroscopy of the metal-poor candidates initiat- 
ed at the du Pont telescope in 1999, however, 
eliminated the forgers to produce a list of bona 
fide metal-poor stars. "We don't even know 
where the carbon in our bones came from," says 
Preston. He expects that in the next decade spec- 
tral analysis of these extremely metal-poor stars 
at the Magellan telescopes will shed light on this 
and many other questions about the creation 
and evolution of the chemical elements in the 
universe — and in our bones. 

Miguel Roth 

The interstellar medium contains all of the com- 
ponents from which stars are formed. It changes 
continuously as stars evolve and return part of the 
processed material to the medium. There are two 
particularly interesting phenomena in the process- 
ing of the interstellar medium: supernovae explo- 
sions and planetary nebulae (PN). Both phenome- 



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na, particularly the supernovae explosions, are 
sources of heavy elements. 

Over the past five years, Roth has been involved in 
the study of "old" PNs. These nebulae arise from 
stars of intermediate 
mass that, during their 
evolution, expel an 
important fraction of 
their mass. The mater- 
ial that surrounds the 
evolved and very hot 
star at the core of the 
PN contains several 
distinctive elements, in 
particular, hydrogen, 
nitrogen, and oxygen. 

PNs display a great variety of shapes; old ones tend 
to be rather spherical, with the star displaced from 
the geometrical center. This shape is indicative of 
the interaction of the PN with the medium that 
surrounds it. Spectroscopic determinations of the 
relative abundance of the elements H, N, and O 
can be correlated with optical and infrared images 
to understand the mechanisms involved in the ori- 
gin and evolution of these objects. 

A comparable scenario can be pictured when 
studying the evolution of the much more energetic 
expansion of material from supernovae explosions. 
Roth has looked at the interaction of some super- 
nova remnants with the interstellar medium. In 
these cases, radio techniques were used to study 
the "clumpy" distribution of molecular species such 
as CO and H 2 . When these data were correlated 
with tracers of star formation, the possibility of 
induced star formation became apparent. This may 
well be one of the mechanisms that trigger the for- 
mation of new generations of stars. Our Sun was 
formed as a consequence of such an explosion. 

Sequential star formation is also probably present 
in areas surrounding what are known as HII 
regions. In some cases, very massive and short-lived 
stars ionize their surrounding medium and com- 
press it as the HII region expands. Analysis of 
infrared images obtained at Las Campanas and 



I A GRISM is a special combination of diffraction Grating and pRISM used to analyze starlight. 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 75 



images obtained with the Hubble Space Telescope 
confirmed the existence of a new generation of very 
young stars in the surroundings of a massive cluster 
known as R136. This cluster is located in the 
Tarantula Nebula, in the Large Magellanic Cloud. 

Roth is collaborating with Mark Phillips (see 
above) to study the evolution of light curves of 
supernovae in infrared light. Using the evolution of 
the light curve, it is possible to determine accurately 
the peak luminosity of supernovae (Phillips Law). 
This information will allow the researchers to 
determine the distance to the host galaxies of these 
objects and the rate of expansion of the universe. 

Infrared measurements have been mentioned sev- 
eral times in this essay. Accurate determinations of 
the luminosities of astronomical objects require 
the use of what are known as standard stars. It was 
necessary to establish a reliable list of such stan- 
dards — rather tedious but fundamental work. 
Astronomers at Las Campanas devoted many 
nights to the systematic measurement of a body of 
such new stars, and researchers all over the world 
now use these standards. 

Stephen Shectman 

During the past year, Stephen Shectman spent five 
months in residence at the Las Campanas 
Observatory working on the control system for the 
Magellan I telescope. This work was conducted in 
collaboration with many members of the Magellan 
Project staff, particularly Joe Asa, Greg 
Bredthauer, Dave Carr, Emilio Cerda, Charlie 
Hull, Matt Johns, and Frank Perez. 

There are several highlights from the control sys- 
tem work. For instance, the precision optical tape 
encoders were installed; they provide accurate 
information about the position of the telescope 
axes. The servomotor drives and amplifiers were 
brought into reliable operation, and accurate servo 
control of the telescope mount was implemented. 
When the telescope is tracking the position of a 
star, the telescope's motion is controlled to an accu- 
racy of a few hundredths of an arcsecond. In order 
to achieve this precision, the positions of the large 



structural components of the telescope mount must 
be maintained to within about 1 micron. 

An accurate time-base, using signals from the 
Global Positioning System, was also installed in 
the system. A small telescope and TV camera were 
attached to the side of the mount, and a map of 
pointing corrections was derived by measuring 
more than 100 star positions around the sky. 
These corrections were needed for the manufac- 
turing tolerances and mechanical flexure of the 
telescope structure, which are many times greater 
than the allowable uncertainties in the telescope's 
positioning. The computer control system uses the 
pointing corrections to set the telescope to within 
a few arcseconds of any position on the sky. The 
telescope mount and its control system are now 
reliable enough and safe enough to allow the pri- 
mary mirror and cell to be installed. 

Shectman has also been working with Hubble 
Fellow Rebecca Bernstein on the construction of 
MIKE, the high-resolution optical spectrograph 
for Magellan. This spectrograph features separate 
optical paths for the red and blue parts of the spec- 
trum. These permit the optical design, dispersing 
elements, antireflection coatings, and detectors to 
be optimized separately for the red and the blue. 
The spectrograph will be able to measure the 
entire optical spectrum of an object between 3,300 
and 10,000 angstroms in a single observation, with 
a resolution of a few tenths of an angstrom. 

During the past year, Shectman and Bernstein 
finalized the optical design of the spectrograph, 
ordered and received all of the optical glass, and 
sent the first components to the optical contractor 
for polishing. They also worked with consulting 
engineer Steve Gunnels to define the mechanical 
structure of the device. 

Working with engineers from L&F Industries, 
Shectman also conducted a design study for a 
major modification of the 2.5-m du Pont telescope 
at Las Campanas. This modification would add a 
Newtonian focus and corrector to the top end of 
the telescope, where a mosaic CCD camera could 
be used to image a one-square-degree-area of the 
sky. This area is more than six times larger than 



CARNEGIE INSTITUTION 



page 74 I YEAR BOOK p8~pp 



can be observed with a comparable mosaic camera 
at the present Cassegrain focus. Such a wide-field 
camera would be particularly interesting for con- 
ducting wide-area photometric surveys as well as 
real-time searches for distant supernovae, gravita- 
tional lens events, and variable stars. These exam- 
ples require massive computational power, which 
has only recently become available and affordable. 

Ian Thompson 

The distances and ages of globular clusters — 
spherical systems consisting of upwards of 100,000 
stars in our galaxy — are key stepping-stones on the 
path to understanding the age and scale of the 
universe. Globular clusters are among the oldest 
components of our galaxy. Previous measurements 

of the distances to 
them have compared 
the characteristics of 
different types of 
stars found in our 
solar neighborhood 
(for which we can 
estimate distances) 
with the same types 
of stars found in the 
clusters. For various 



Ian Thompson 



reasons, measure- 
ments of the globular 
cluster distances suffer from systematic errors and 
remain the limiting factor in determining the ages 
of these objects. 

Ian Thompson, with colleagues at the 
Observatories and the University of Warsaw, has a 
different approach to this distance problem. 
Observations of detached eclipsing binary stars 
allow a geometric measurement of distances. These 
systems are composed of two separated stars that 
orbit about each other, with the orbital plane in the 
line of sight to the stars. As one star passes in front 
of the other, the total light is modulated. Analysis 
of the shapes of these eclipses permits a measure- 
ment of the relative sizes of the stars and their sep- 
aration. After additional observations are made of 
the variations of the radial velocities of the two 
stars, the absolute dimensions of the system can be 




derived from a simple application of Kepler's laws 
of gravity. Once the absolute sizes of the individual 
stars in the binary are known, the distance to the 
system can be measured by comparing the appar- 
ent brightness of the stars to their surface bright- 
ness as estimated from the infrared colors. 

Thompson is searching for these exceedingly rare 
stars using the Swope 1-m telescope to monitor a 
selection of nearby southern globular clusters. 
Many nights of continuous monitoring are needed 
to detect the eclipses and then measure their 
orbital periods. Detailed measurements of the 
shape of the light curves are made with the du 
Pont 2.5-m telescope. When the Magellan tele- 
scopes are operational, the radial velocity curves 
will be measured with the echelle spectrograph. 
Although only one or two eclipsing binaries are 
expected to be detected in each cluster, these will 
be sufficient to overhaul our imperfect knowledge 
of their distances and ages. This research, and the 
collaboration with George Preston, Andrew 
McWilliam, and Steve Shectman in the search for 
extremely metal-poor stars, will show the new way 
in which the smaller telescopes at Las Campanas 
will be used in the upcoming Magellan era. 
Resources will be devoted to extensive surveys for 
interesting objects that can be studied in greater 
detail with the twin telescopes. 





•--. 


" 


■ 


1 + 0.45 


- 


-•~-. 


17 


■;■' 




'■-■ 






-s 








V 


V 








H 










**■ 


17,5 


\"~ 






B-0.25 




i 



0.5 

phase 



Fig. 10. This image shows light curves of a detached eclipsing 
binary in the globular cluster Omega Centauri, as measured 
in the blue, visual, and near-infrared. The eclipses occur at 
phases 0.0 and 0.5, and the different depths of the eclipses 
indicate that the two stars in the binary are not equally bright. 



:arnegie institution 



YEAR BOOK p8~pp page 7J 




RayWeymann 

Much of Ray Weymann's time during the past year 
was devoted to organizing, convening, and editing 
the proceedings of a workshop entitled 
"Photometric Redshifts and High Redshift 
Galaxies." The event was 
held in the William T. 
Golden Auditorium at 
the Observatories in 
Pasadena during April 
28-30, 1999. Stimulated 
by research using the 
Space Telescope NIC- 
MO S camera (described 
below), the workshop 
was attended by about 
65 astronomers from 
the U.S. and abroad. 

Photometric redshifts use direct images of galaxies 
taken in several bandpasses to estimate the redshift, 
or distance, of galaxies. The virtues of this tech- 
nique are that it can produce redshifts of huge num- 
bers of galaxies much more efficiently (in terms of 
telescope time), and it can view the bodies to much 
fainter brightness levels than can the more accurate 
method of measuring galaxy spectra with large tele- 
scopes. A closely related topic that was addressed 
involves the search for extremely distant galaxies to 
trace the history of star and galaxy formation in the 
very early phase of the expanding universe. The 
proceedings of the workshop are in volume 191 of 
the Astronomical Society of the Pacific Conference 
Series published in late November. Lisa Storrie- 
Lombardi, formerly of the Observatories and now 
at Caltech, and Robert Brunner and Marcin 
Sawicki (also of Caltech) collaborated with 
Weymann to organize the workshop. 

The impetus for the workshop came from research 
using observations with the infrared NICMOS 
camera on the Hubble Space Telescope. The obser- 
vations, combined with previous visible light obser- 
vations in the Hubble Deep Field, provided a set of 
images ideally suited for both the determination of 
photometric redshifts and the search for a very high 
redshift galaxy. This search yielded one galaxy that 
was confirmed to have a redshift of z = 5.6 based on 
spectroscopic observations made with the Keck tele- 











1 


» 




• " 




" - ( 






' 


h * 






1 






♦ 




™ F60GW 




F814W 




ig. II. These are Hubble Space Telescope images of a 
galaxy at a redshift of 5.6. The images labeled F606W and 
F8I4W were taken with a visible light CCD camera, and 
those labeled F I 1 0W and F 1 60W were taken with the 
infrared NICMOS camera. The galaxy, labeled HDF 
4-473.0, is relatively bright in the two infrared images, 
much fainter in the F8I4W image, and invisible in the 
shortest-wavelength image, F606W. The brightness ratio of 
these images has a distinctive signature indicative of a high- 
redshift star-forming protogalaxy and illustrates the use of 
the photometric redshift technique. The redshift of this 
very distant object was confirmed using the Keck telescope 
on Mauna Kea after several hours of exposure. 



scope. The images that identified this as a likely can- 
didate for a very high redshift galaxy are shown in 
Fig. 11. The main goal of the current research is to 
see whether, and how well, astronomers can estimate 
both the redshift of the galaxies using the photomet- 
ric redshift technique and simultaneously estimate 
the internal dust absorption of the ultraviolet light 
associated with stars being formed in the galaxy or 
protogalaxy. It has recently become apparent that 
correction for this absorption is crucial to obtaining a 
true picture of the rate at which stars have been 
forming in the history of the universe. This is far 
more difficult than estimating only the redshift since 
the colors of a galaxy undergoing a vigorous burst of 
star formation, coupled with moderately heavy dust 
absorption, closely mimics the colors of a galaxy with 
only moderate star-formation rates and little or no 
dust absorption. 

In a different field of extragalactic astronomy, 
Weymann is analyzing data on a bright quasar taken 
with the new STIS spectrograph on the Hubble 
Space Telescope. He will compare the properties of 
intergalactic hydrogen gas clouds and their associa- 
tion with galaxies with the predictions from com- 
puter simulations of the evolving universe. These 
data are being augmented by spectroscopic redshifts 
of galaxies close to the quasar (in angle, not dis- 
tance) observed with the 2.5-m du Pont telescope. 



CARNEGIE INSTITUTION 



Observatories' Personnel 



YEAR BOOK p8~pp 



Research Staff Members 

Alan Dressier 

Wendy Freedman 

Patnck McCarthy 

Andrew McWilliam 

Augustus Oemler, Jr., Director 

Eric Persson 

George Preston 

Allan Sandage, Emeritus Staff Member 

Leonard Searie, Director Emeritus 

Stephen Shectman 

Ian Thompson 

Ray Weymann 

Senior Research Associate 

Luis Ho 1 

Postdoctoral Fellows and Associates 

Martin Beckett, Magellan Instrumentation Fellow 2 

Rebecca Bernstein, Hubble Fellow 3 

Scott Chapman, Magellan Instrumentation Fellow* 

Julianne Dalcanton, Fellow 5 

Carme Gallart, Research Fellow 6 

Mauro Giavalisco, Hubble Fellow 6 

Ron Marzke, Hubble Fellow 

John Mulchaey, Fellow 

Jason Prochaska, Carnegie Fellow 7 

Lisa Storrie-Lombardi, Research Associate 

Scott Trager, Starr Fellow 

Ben Weiner, McClintock Fellow 

Lin Yan, Research Associate 

Predoctoral Fellow 

Yasuhiro Hashimoto, Predoctoral Fellow 

Las Campanas Research Staff 

William Kunkel, Resident Scientist 

Mark Phillips, Associate Director, Las Campanas 

Observatory 8 
Miguel Roth, Director, Las Campanas Observatory 

Las Campanas Fellow 

Gaspar Galaz, Andes/Carnegie Fellow 

Support Scientists 

Bruce Bigelow, Instrument Scientist 
Greg Burley, Instrument Scientist 
David Murphy, Instrument Scientist 
Brian Sutin, Optical Scientist 

Supporting Staff, Pasadena 

Joseph Asa, Magellan Electronics Technician 
Alan Bagish, Las Campanas Observatory Engineer 
Christoph Birk, Data Acquisition Program 
Richard Black, Purchasing 9 



Tim Bond, Mechanical Engineer 10 

Greg Bredthauer, Magellan Project Support Engineer 

David Carr, Magellan Project Instrument Engineer 

Ken Clardy, Programmer 

Paul Collison, Computer Systems Manager 

Marinus de Jonge, Magellan Project Construction 

Manager 
Joan Gantz, Assistant Librarian" 
Darrell Gilliam, Electronics Technician 
John Grula, Head Librarian, Information 

Services/Publications Manager 
Bronagh Glaser, Administrative Assistant 
Karen Gross, Assistant to the Director 
Earl Harris, Assistant Building and Grounds 
Steve Hedberg, Accountant 
Charles Hull, Magellan Project Mechanical Engineer 
Matt Johns, Magellan Project Manager 
Sharon Kelly, Buyer 12 
Imelda Kirby, Data Reduction Assistant' 2 
Aurora Mejia, Housekeeper 
Robert Mejia, Housekeeper 
Georgina Nichols, Controller 
Greg Ortiz, Assistant, Buildings and Grounds 
Stephen Padilla, Photographer 
Frank Perez, Magellan Project Lead Engineer 
Emily Petty, Magellan Project Administrative 

Assistant 
Pilar Ramirez, Machine Shop Foreperson/lnstrument 

Maker 
Scott Rubel, Assistant, Building and Grounds 
Jeanette Stone, Purchasing Manager 
Robert Storts, Instrument Maker 
Richard Surnock, Instrument Maker" 
Estuardo Vasquez, Instrument Maker 
Steven K Wilson, Facilities Manager 

Supporting Staff, Las Campanas 

Victor Aguilera, Magellan Project Electronic Engineer 

Carolina Alcayaga, Purchasing Officer 

Richard Alcayaga, Mechanic 

Heman Angel, Driver/Purchaser 7 

Yerko Aviles, Administrative Assistant 

Hector Balbontin, Chef 

Eduardo Carvajal, El Pino Guard' 5 

Pedro Carrizo, Plumber 

Emilio Cerda, Magellan Electronics Technician 

Oscar Cerda, janitor 

Angel Cortes, Accountant 

Jose Cortes, Janitor 

Jorge Cuadra, Mechanic Assistant 

Oscar Duhalde, Mechanical Technician 

Julio Egana, Painter 

Juan Espoz, Mechanic 

Luis Gallardo, El Pino Guard 16 

Juan Godoy, Chef 

Jaime Gomez, Accounting Assistant 

Danilo Gonzalez, El Pino Guard 

Javier Gutierrez, Heavy Equipment Operator 

Juan Jeraldo, Chef 

Leonel Lillo, Carpenter 

Juan Lopez, Magellan Project Supervisor 

Mario Mondaca, El Pino Guard 



Cesar Muena, Night Assistant 

Pascal Munoz, Cook 

Silvia Munoz, Business Manager 

Herman Olivares, Night Assistant 

Fernando Peralta, Night Assistant 

Patricio Pinto, Electronics Technician 

Robert Ramos, Gardener 

Demesio Riquelme, Janitor 

Andres Rivera, Electronics Technician 2 

Hugo Rivera, Night Assistant 

Honorio Rojas, Water Pump Operator 

Hernan Solis, Electronics Technician' 7 

Jose Soto, Magellan Software Engineer 

Gabriel Tolmo, El Pino Guard 

Hector Torres, Magellan Janitor 

Manuel Traslavina, Heavy Equipment Operator 

David Trigo, Mountain Operations Supervisor 

Geraldo Valladares, Magellan Telescope Operator' 

Patricia Villar, Administrative Assistant 

Visiting Investigators 

Roberto Abraham, Cambridge University, 

Pablo Araya, Catholic University of Chile 

Alex Athey, University of Michigan 

Ian Beuing, University of Sao Paulo, Brazil 

Leonardo Bronfman, University of Chile 

Ray Carl berg, University of Toronto 

Rodrigo Carrasco, University of Sao Paulo, Brazil 

Edgardo Costa, University of Chile 

Vandana Desai, University of Washington 

Richard Ellis, Cambridge University 

Andrew Firth, Cambridge University 

Peter Frenchaboy, California State University, 

Sacramento 
Douglas Geisler, University of Concepcion 
Eva Gerbel, University of Colorado 
Wolfgang Gieren, University of Concepcion 
Eduardo Gonzalez, University of Chile 
John Graham, Department of Terrestrial Magnetism 
Jason Harris, University of California at Santa Cruz 
George Hau, Catholic University of Chile 
Michael Hicks, Jet Propulsion Laboratory 
Leopoldo Infante, Catholic University of Chile 
januz Kaluzny, Warsaw University 
Dan Kelson, Department of Terrestrial Magnetism 
Florian Kerber, Innsbruck University 
Marcin Kubiak, Warsaw University 
Randy Kuehnel, Department of Terrestrial 

Magnetism 
Arlo Landolt, Louisiana State University 
Lori Lubin, California Institute of Technology 
Barry Madore, California Institute of Technology 
Steve Majewski, University of Virginia 
David Martinez, Canary Islands Institute of 

Astrophysics, Spain 
Jose Maza, University of Chile 
Mario Mateo, University of Michigan 
Stacy McGaugh, University of Maryland 
Craig McKay, Cambridge University 
Kevin McLin, University of Colorado 
Richard McMahon, Cambndge University 
Ricardo Munoz, University of Concepcion 



Observatories' Personnel 



:arnegie institution 



YEAR BOOK p8~pp page JJ 



Mike Pah re, Harvard University 
Chris Palma, University of Virginia 
Richard Patterson, University of Virginia 
Isabel Perez, University of Chile 
Randy Phelps, California State University, 

Sacramento 
Grzegorz Pietrzynski, Warsaw University 
Grzegorz Pojmanski, Warsaw University 
Wojciech Pych, Warsaw University 
Hernan Quintana, Catholic University of Chile 
Thomas Rauch, Innsbruck University 
Mike Regan, Department ofTerrestnal Magnetism 
Neill Reid, California Institute of Technology 
Vera Rubin, Department of Terrestrial Magnetism 
Monica Rubio, University of Chile 
Mike Segal, University of Virginia 
Ian Smail, University of Durham 
Todd Small, California Institute of Technology 
John Stocke, University of Colorado 
Michal Szymanski, Warsaw University 
Andrzej Udalski, Warsaw University 
Eduardo Unda, University of Concepcion 
Stuart Vogel, University of Maryland 
Marina Wichjenewski, University of Chile 
Paul Weissman, Jet Propulsion Laboratory 
Josh Winn, Massachusetts Institute of Technology 
Ann Zabludoff, University of California at Santa Cruz 
Dennis Zantsky, University of California at Santa Cruz 



'From August 10, 1998 
! From October 10, 1998 
J From November I, 1998 
'From June I, 1999 
To August 3 1, 1998 
'To December 3 1 , 1998 
'From September 1 , 1 998 
"From July I, 1998 
'Deceased February 5, 1999 
"From October 5, 1998 
'Retired June 3,0, 1999 
'FromApnl I, 1999 
To August 31. 1999 
'From December 1 , 1 998 
s From September 28, 1998 
To September 10. 1998 
To September 30. 1998 



YEAR BOOK p8~pp 



Observatories' Bibliography 



Barger, A. J., A. Aragon-Salamanca, I. Smail, 
R. S. Ellis, W. J. Couch, A. Dressier, A. 
Oemler, B. M. Poggianti, and R. M. Sharpies, 
New constraints on the luminosity evolu- 
tion of spheroidal galaxies in distant clusters, 
Astrophys.J. 591, 552, 1998. 

Barth, A. J., L C. Ho, A. V. Filippenko, and 
W. L W. Sargent, A search for ultraviolet 
emission from LINERs, Astrophys.J. 496, I 33, 



Bigelow, B. C, A. Dressier, S. A. Shectrman, 
and H. Epps, IMACS: the multiobject spec- 
trograph and imager for the Magellan I tele- 
scope, S.P.I.E. 3355, 225, 1 998. 

Brandt, J. C, S. R. Heap, E. A. Beaver, A. 
Boggess, K. G. Carpenter, D. C Ebbets, J. B. 
Hutchings, M. Jura, D. S. Leckrone, J. L 
Linsky, S. P. Maran, B. D. Savage, A. M. 
Smith, L M. Trafton, F. M. Walter, R J. 
Weymann, G. M. Wahlgren, S. G. Johansson, 
H. Nilsson, T. Brage, M. Snow, and T. B. Ake, 
A Goddard high resolution spectrograph 
atlas of echelle observations of the HGMN 
star Chi Lupi, Astron.j. 117, 1505, 1999. 

Calvani, H„ A. R. Koratkar, S. Deustua, I. N. 
Evans, A. V. Filippenko, T. M. Heckman, and 
L G Ho, UV spectral distribution in 
low-luminosity active galaxies, Bull. Am. 
Astron.Soc 193,0707, 1999. 

Davis, D. S., J. S. Mulchaey, and R F. 
Mushotzky, The enrichment history of hot 
gas in poor galaxy groups, Astrophys.J. 511, 
34, 1999. 

Dressier, A., The journey back to the 
source, Sky & Telescope 96, 46, 1998. 

Dressier, A., Scientific goals and challenges 
for the NGST, The Next Generation Space 
Telescope: science drivers and technological 
changes: Proceedings of the 34th Liege 
International Astrophysics Colloquium, p. 25, 
European Space Agency, Netherlands, 1 998. 

Dressier, A., I. Smail, B. M. Poggianti, H. 
Butcher, W. J. Couch, R. S. Ellis, and A. 
Oemler, A spectroscopic catalog of 1 dis- 
tant rich clusters of galaxies, Astrophys.J. 
Suppl. 122,51, 1999. 

Falcke, H, W. M. Goss, L C. Ho, H. Matsuo, 
R. Teuben, A. S. Wilson, J.-H. Zhao, and R. 
Zylka, Sgr A* and company — multiwave- 
length observations of Sgr A* and VLA 
search for "Sgr A*s" in LINERs, in IAU Colloq. 
1 64, Radio Emission from Galactic and 
Extragalactic Compact Sources, A. Zensus, G. 
Taylor, and J. Wrobel, eds., p. 323, 
Astronomical Society of the Pacific, San 
Francisco, 1998. 

Falcke, H., and L C, Ho, Radio nuclei in 
nearby galaxies, in Annual Scientific Meeting of 
the Astronomische Gesellschaft 14, H06, 1999. 

Freedman, W. L, Measurement of the 
Hubble constant, Physics Reports 307, 45, 
1998. 

Freedman, W. L, Measuring cosmological 
parameters, Proc. Natl. Acad. Sci. USA 95, 2, 
1998. 

Freedman, W. L, J. R Mould, R C 
Kennicutt, and B. F. Madore, The Hubble 
Space Telescope key project to measure 



the Hubble constant, in Cosmological 
Parameters and the Evolution of the Universe, K. 
Sato, ed., Reidel, Dordrecht, pp. 1 7-30, 1 999. 

Gallart, C, W. L Freedman, M. Mateo, C 
Chiosi, I. B. Thompson, A. Aparicio, G. 
Bertelli, G. P. Hodge, M. G. Lee, E. Olzewski, 

A. Saha, P. Stetson, and N. Suntzeff, HST 
observations of the local group dwarf galaxy 
Leo I, Astrophys.J. 514, 665, 1999. 

Garnavich, P. M., S. Jha, P. Challis, A. 
Clocchiatti, A. Diercks, A. V. Filippenko, R. L 
Gilliland, C. J. Hogan, R P. Kirshner, B. 
Leibundgut, M. M. Phillips, D. Reiss, A. G. 
Riess, B. P. Schmidt, R. A. Schommer, R C. 
Smith, J. J. Spyromilio, C Stubbs, N. B. 
Suntzeff, J. Tonry, and S. M. Carroll, 
Supernova limits on the cosmic equation of 
state, Astrophys. J. 509, 74, 1 998. 

Garnavich, P. M., R P. Kirshner, P. Challis, J. 
Tonry, R. L Gilliland, R. C. Smith, A. 
Clocchiatti, A. Diercks, A. V. Filippenko, M. 
Hamuy, C. J. Hogan, B. Leibundgut, M. M. 
Phillips, D. Reiss, A. G. Riess, B. P. Schmidt, 
R. A. Schommer, J. Spyromilio, C. Stubbs, N. 

B. Suntzeff, and L. Wells, Constraints on 
cosmological models from Hubble Space 
Telescope observations of high-z super- 
novae, Astrophys. J. 493, L53, 1998. 

Gibson, B., W. L Freedman, B. F. Madore, et 
al., The Hubble Space Telescope key pro- 
ject on the extragalactic distance scale. XVII. 
The Cepheid distance to NGC 4725, 
Astrophys.J. 512,48, 1999. 

Gilliland, R L, P. E. Nugent, and M. M. 
Phillips, High-redshift supermovae in the 
Hubble Deep Field, Astrophys.J. 521, 30, 
1999. 

Graham, J., L Ferrarese, W. L Freedman, et 
al., The Hubble Space Telescope key pro- 
ject on the extragalactic distance scale. XX. 
The discovery of Cepheids in the Virgo 
Cluster galaxy NGC 4548, Astrophys.J. 5 1 6, 
626, 1999. 

Hashimoto, Y„ and A. Oemler, The concen- 
tration-density relation of galaxies in the Las 
Campanas redshift survey, Astrophys.J. 510, 
609, 1999. 

Hines, D. C, F. J. Low, R. I. Thompson, R J. 
Weymann, and L. Storrie-Lombardi, The 
host galaxy of the broad absorption line 
QSO PG 1 700 +5 1 8 and its ring galaxy 
companion: NICMOS 1.6 micron imaging, 
Astrophys.J. 512, 140, 1999. 

Ho, L, C, Supermassive black holes in galac- 
tic nuclei: observational evidence and some 
astrophysical consequences, in Observational 
Evidence for Black Holes in the Universe, S. K. 
Chakrabarti, ed., p. 1 57, Kluwer, Dordrecht, 



Ho, L C, LINERs as low-luminosity active 
galactic nuclei, Advances in Space Research 23, 
813, 1999. 

Ho, L C, Observational evidence for super 
star clusters as progenitors of globular clus- 
ters, Bull. Am. Astron. Soc. 194, 4009, 1999. 

Ho, L C, The spectral energy distributions 
of low-luminosity active galactic nuclei, Bull. 
Am. Astron. Soc. 193, II 904, 1 999. 



Ho, L C, The spectral energy distributions 
of low-luminosity active galactic nuclei, 
Astrophys. J. 5 1 0, 672, 1999. 

Ho, L C, What powers the compact radio 
emission in nearby elliptical and SO galaxies? 
Astrophys. J. 5 1 0, 631, 1999. 

Ho, L C, A. V Filippenko, and W. L W. 
Sargent, Demographics of nuclear activity in 
nearby galaxies, in IAU Symp. 184, The Central 
Regions of the Galaxy and Galaxies, Y. Sofue, 
ed., p. 463, Kluwer, Dordrecht, 1 998. 

Jannuzi, B. T, R J. Weymann, et al., The 
Hubble Space Telescope quasar absorption 
line key project. XIII. A census of absorption 
line systems at low redshift, Astrophys.J. 
Suppl. 118, I, 1998. 

Kells, W., A. Dressier, A. Sivaramakrishnan, 
D. Carr, E. Koch, H. Epps, D. Hilyard, and G. 
Pardeilhan, COSMIC: a multiobject spectro- 
graph and direct imaging camera for the 5- 
meter Hale Telescope prime focus, Pub. 
Astron. Soc. Pacific I 10, 1487, 1998. 

Kelson, D., W. L Freedman, B. F. Madore, et 
al., The Hubble Space Telescope key pro- 
ject on the extragalactic distance scale. XIX. 
The discovery of Cepheids in and a new 
distance to NGC 3 1 98, Astrophys.J. 5 1 4, 
614, 1999. 

Kerber, F„ J. Koppen, M. Roth, and S. C 
Trager, The hidden past of Sakurai's object: 
stellar properties before the final helium 
flash, Astron. & Astrophys. 344, L79, 1 999. 

Kraemer, S. B., L C Ho, D. M. Crenshaw, A. 
V Filippenko, and J. C Shields, Physical con- 
ditions in the emission-line gas in the least 
luminous Seyfert I galaxy, NGC 4395, Bull. 
Am. Astron. Soc. I 93, 0706, 1 999. 

Kulkami, S. R., J. S. Mulchaey, et al., The 
afterglow, redshift, and extreme energetics 
of the gamma-ray burst of 23 January 1 999, 
Nature 398, 389, 1 999. 

Madore, B. F., W. L Freedman, et al., The 
Hubble Space Telescope key project on the 
extragalactic distance scale. XV. A Cepheid 
distance to the Fornax cluster and its impli- 
cations, Astrophys. J. 515, 29, I 999. 

Mahabal, A., A. Kambhavi, and P. J. 
McCarthy, Effective radii and color gradients 
in radio galaxies, Astrophys. J. 5 1 6, 6 1 L, 1 999. 

Maoz, D„ A. R Koratkar, J. C Shields, L C 
Ho, A. V. Filippenko, and A. Sternberg, The 
ultraviolet spectra of LINERs: a comparative 
study, Astron.j. 1 16,55, 1998. 

Maoz, D., A. Sternberg, and L. C. Ho, 
"Super star clusters" revealed in NICMOS 
images of circumnuclear rings, Bull. Am. 
Astron. Soc. 1 93, 7604, 1 999. 

Martel, A., S. Baum, W. Sparks, E. Wykoff, J. 
Biretta, D. Golombek, F. Macchetto, S. de 
Koff, P. J. McCarthy, and G. Miley, HST 
snapshot survey of 3CR radio source coun- 
terparts. III. Radio galaxies with z < 0. 1 , 
Astrophys. J. Suppl. 122,81, 1999. 

Martel, A., W. Sparks, D. Macchetto, J. 
Biretta, S. Baum, D. Golombek, P. J. 
McCarthy, S. de Koff, and G. Miley, New 
optical fields and candidates of 10 3C radio 



Here updated through November 15, 1999. The Obseivatones does 

cles. However, the abstract and. in some cases, full text of many ofthi at the NASA Astrophysics 

Data Systems Web site at http://adswww.haivard.edu/, or at !!•< 



/vww.iournals.uchicivi i.ec 



;arnegie institution 



YEAR BOOK pS—pp I page yp 



sources. I. The R-band images, Astron.J. 1 15, 
1348, 1998. 

Martel, A., W. Sparks, D. Macchetto, J. 
Biretta, S. Baum, D. Golombek, P. J. 
McCarthy, S. de Koff, and G. Miley, 
Discovery of an optical synchrotron jet in 
3C 15, Astrophys.J. 496, 203, 1998. 

Mcintosh, D. H, M. J. Rieke, H.-W. Rix, C. B. 
Foltz, and R J. Weymann, A statistical study 
of rest-frame optical emission properties in 
luminous quasars at 2.0 < z < 2.5, Astrophys. 
J. 514, 40, 1999. 

Mulchaey, J. S., and A. I. Zabludoff, The iso- 
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1999. 



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Geophysical Laboratory 



c 



ARNEGIE INSTITUTION 



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THE DIRECTORS INTRODUCTION 



"There is fertile ground in the seams between the traditional disci- 
plines WHERE THE NEW DISCOVERIES ARE TAKING PLACE." 



grow steadily under the leadership of Dave Mao, 
Rus Hemley, and the lab's last director, Charles 
Prewitt. This growth was accelerated nine years 
ago with the establishment, by the National 
Science Foundation (NSF), of the Center for 
High Pressure Research. The Geophysical Lab is a 
member of a consortium that includes the State 
University of New York (SUNY) Stony Brook, 
UC Davis, and UC San Diego. A critical part of 
the consortium's work is the use of the second- 
generation x-ray synchrotron source at 
Brookhaven National Laboratory. 



Qince its inception in 1905, the Geophysical 
Laboratory (GL) has been one of the world's fore- 
most laboratories in the science of petrology — the 
study of rocks. GL scientists are renowned for 
their research into the formation and evolution of 
terrestrial rocks. A major goal of this science has 
been to understand the physics and chemistry of 
the Earth's deep interior. Toward this end, the lab 
has remained at the forefront of high-pressure and 
high-temperature research. 

GL has pioneered many laboratory methods in 
high-pressure research. The advent of the dia- 
mond-anvil pressure cell in the 1960s, and its 
development since, has been a hallmark of this 
work. Over the years, many new methods and 
instruments have been developed to improve the 
cell's ability to measure the physical and chemical 
properties of materials and the transformations 
they undergo with changing pressure and tempera- 
ture. As a result, unsuspected phenomena of fun- 
damental, condensed matter have been discovered 
and have been applied to problems in understand- 
ing the interiors of the Earth, Mars, and the gas 
giant planets such as Jupiter. 

With GL's global reputation in high-pressure 
physical science, this research area continues to 

Left: Fu and Cohen presented a model for understanding the huge electromechanical coupling in new single-crystal piezoelectncs. They tested 
the model by studying BaTi0 3 , a classic ferroelectric. The figure opposite is a 3-D polar plot that shows the computed c-axis strain as a function 
of polarization direction in BaTiCX The bow-shaped area is negative. Large strains can be obtained by rotating the polanzation direction. (Image 
courtesy Ronald Cohen.) 




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The NSF funded the center for a limited, 11-year 
period. The vision now is to establish a long-term 
center at GL. The staff would consist of mineral 
physicists, petrologists, physicists, and chemists. 
They would use laboratories and computers at GL 
and leverage costly national facilities at Argonne 
National Laboratory and Brookhaven to investi- 
gate materials at ever increasing pressures. Toward 
this end, a new high-pressure collaborative access 
team has just been formed, under the direction of 
Dave Mao, to build and operate a new dedicated 
beamline facility for high-pressure x-ray materials 
science at the third-generation Advanced Photon 
Source at Argonne. 

Although petrology has been a mainstay at the lab 
since it originated, GL research has branched out 
along the way. Former director Philip H. Abelson 
broadened the scope 50 years ago to include biology 
when he extracted amino acids from ancient 
clamshells. This began a new direction into biogeo- 
chemistry that continues today. Current efforts in 
this field, under the leadership of Marilyn Fogel and 
Doug Rumble, include stable isotope studies and 
molecular and biochemical research. This work has 



been applied to organic geochemistry, paleoecology, 
oceanography, human nutrition, and ecology. 

New equipment and new analytical techniques 
have yielded unanticipated discoveries. 
Instruments shared by GL and the Department of 
Terrestrial Magnetism (DTM) were coupled with 
a new technique for extracting organic materials 
from rock. The result is a joint GL/DTM research 
project characterizing fossil biomolecules in 
ancient terrestrial rocks. The newly developed 
methods were then applied to the study of astro- 
chemistry in meteorites. This led to a break- 
through: the identification within meteorites of 
chemical processes in the early solar nebula that 
were preserved separately from processes that 
occurred in the parent body of the meteorite after 
the planets accreted. 

The broadening of geochemistry to include plane- 
tary chemistry, biogeochemistry, and astrochem- 
istry has recently spread into astrobiology — the 
search for the origins of life on Earth and the 
potential for its existence elsewhere. The 
Geophysical Lab's strategic approach to astrobiol- 




Members of the Geophysical Laboratory, May 1999. First row (from left): Robert Hazen, Marilyn Fogel, Doug Rumble, Neil Irvine, 
Ho-kwang Mao, Charles Prewitt, Wesley T. Huntress, Hatten Yoder, Joe Boyd, Larry Finger, Yingwei Fei, Bjorn Mysen, George 
Cody, Ronald Cohen, Russell Hemley, John Frantz. Second row: Pedro Roa, Sue Schmidt, Jinfu Shu, Jack Tossell, Steve Gramsch, 
Atlaf Carim, Jie Li, Mark Teece, Oguz Giilseren, Richard Ash, Sue Ziegler, Mikhail Eremets, Maceo Bacote, Pablo Esparza, Paul 
Meeder, Jack Almquist, Roy Scalco, Lawrence Patrick. Third row: Bert Collins, Merri Wolf, Wenjie Jiao, Sebastien Merkel, Zhen- 
xian Liu, Gotthard Saghi-Szabo, Chris Hadidiacos, Tim Filley, Joakim Bebie, Jiirgen Konzett, Bill Minarik, Maddury Somayazulu, 
Viktor Struzhkin. Fourth row: Yanzhang Ma, Bobbie Brown, Margie Imlay, Eugene Gregoryanz, Fred Marton, Alex Goncharov, 
David George, Shaun Hardy, Huaxiang Fu, Steve Coley, John Straub 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 83 




Hatten Yoder (left) and Bob Hazen are two members of the 
astrobiology team at GL 



ogy is twofold: first, to establish the chemistry 
involved in the emergence of biochemistry under 
extreme conditions such as are found at high-pres- 
sure hydrothermal vents at the ocean bottom; and 
second, to explore how minerals of the early Earth 
may have acted as catalysts for the production of 
biologically important molecules. The goal is to 
establish a seamless connection between the young 
geochemical world and the subsequent biochemi- 
cal world. Another product of this work will be to 
understand biomarkers — the molecular and iso- 
topic signatures that indicate the presence of life. 

The lab began investigations into astrobiology in 
1996. Organic geochemist George Cody, mineral 
physicist Bob Hazen, and experimental petrologist 
and former GL director Hatten Yoder conducted 
the first experiments studying the possible role of 
deep-ocean hydrothermal systems in prebiotic 
organic synthesis. Their efforts led to the selection 
of a joint GL/DTM team to be part of NASA's 
virtual Astrobiology Institute in 1998. The insti- 
tute's members across the country are connected 
through the Internet. 

Currently, GL's principal focus in this new science 
is to understand how, under extreme pressure, the 
hot crustal minerals and gases ejected from the 
vents into the seawater can result in the chemical 
resources necessary to support a diverse local bio- 
logical community. Many types of microbes are 



found in the hot waters of ocean-ridge vents. They 
live without light or oxygen on various chemical 
nutrients and may be representative of the earliest 
organisms of a young oxygen-free Earth. By 
understanding these organisms, the GL team 
hopes to discover the earliest chemical mecha- 
nisms used in biology and to develop laboratory 
methods to understand the evolution from prebi- 
otic chemistry to primitive life. 

A closely related avenue for investigation is to 
understand how to recognize the chemical signs of 
life on other planets. This knowledge is critical for 
NASA planetary missions. GL astrochemists and 
astrobiologists are working to participate in these 
missions several ways: by working in the laboratory 
to find ways to spot ancient life from planetary 
samples; by providing the expertise, and possibly 
the instrumentation, for selecting samples to 
return to Earth; and, by using the lab's consider- 
able state-of-the-art instrumentation to analyze 
the returned materials. 

Over the years, the character of science at the 
Geophysical Lab has changed. Traditionally, it 
was a small community of scientists with focused 
objectives who worked in isolation. It has evolved 
to an interactive group working across scientific 
boundaries and with many outside collaborators. 
The lines of inquiry have gone beyond petrology 
and geochemistry. There is fertile ground in the 
seams between the traditional disciplines where 
the new discoveries are taking place. Carnegie has 
a long history of finding new, emerging scientific 
fields. It is this tradition that will create a vital and 
exciting scientific future for the Geophysical 
Laboratory. Independence as a privately endowed 
research institution, and the freedom to pursue 
risky but potentially high-payoff new ventures in 
science, are the enduring characteristics that will 
propel the lab into an exciting, productive, and 
respected future in science. 

— Wesley T. Huntress, Jr. 

Constance Bertka 

An understanding of the formation and evolution 
of the Earth is linked to understanding the forma- 



CARNEGIE INSTITUTION 



page 84 YEAR BOOK p8~pp 





Fig. 2. The planet Mars and the meteorites believed to orij 
nate from it, are subjects of research for Connie Bertka. 



tion and evolution of its terrestrial neighbors. The 
focus of Bertka's research is the interior of Mars. 
She uses high-pressure experimental techniques 
available with the piston-cylinder and multianvil 
apparatus. The goal of her work is to provide the 
necessary data to understand the structure and 
evolution of the Martian interior, in addition to 
the formation of the terrestrial planets. 

Until recently, only limited geophysical data were 
available to determine the composition or structure 
of the Martian interior. Models for the composi- 
tion were derived from the Martian meteorites. 
Bertka, with Staff Member Yingwei Fei, deter- 
mined the high-pressure mineralogy of one mete- 
orite-based model and used this information to 
model the structure of the Martian interior. The 
scientists then compared their data with data on 
the mass distribution of the planet's interior 
obtained from the Mars Pathfinder mission. They 
determined that a commonly assumed notion that 
the terrestrial planets have refractory element bulk 
compositions equivalent to a primitive CI mete- 
orite is invalid. However, their work did verify 
another assumption about the mantle of Mars: it is 
richer in iron than Earth's mantle. 



Bertka's research efforts are currently focused on 
the composition and state of the Martian core. She 
conducts melting experiments and density determi- 
nations of model core compositions. This work will 
enhance accretion models for the formation of 
Mars and the other terrestrial planets, and provide 
the experimental data to compare with seismic data 
from future Mars missions. 

Using existing data from the Martian meteorites 
and data obtained by the Mars Pathfinder mission, 
Bertka has recently started experiments to under- 
stand the formation of textural features in the 
meteorites and to assess the types of melts that 
would be produced from partial melting of an iron- 
rich hydrous source region. Data from current and 
future Mars missions will also provide information 
about the geochemistry of surface materials. An 
experimental database, such as the one Bertka is 
developing in iron-rich systems, is key to under- 
standing the origin and evolution of these materials. 

In addition to her research efforts, Bertka is the 
director of the Carnegie Institution of Washington's 
Summer Intern Program in Geoscience. In the past 
three years, with support from the National Science 
Foundation, the Camille and Henry Dreyfuss 
Foundation, and the Carnegie Institution of 
Washington, the Geophysical Laboratory and the 
Department of Terrestrial Magnetism have invited 
over 40 undergraduate and high school students to 
participate in research projects. During the 10-week 
summer program the students are introduced to 
hands-on scientific research with guidance from 
Staff Members. They also tour other research facili- 
ties in the area, participate in a weekly informal 
lunch meeting with the Carnegie scientific staff, and 
present their work at a final summer intern sympo- 
sium. Several of the students have also presented the 
results of their Carnegie research at national meet- 
ings. 

Nabil Z. Boctor 

Boctor's research focuses on the oldest known 
Martian meteorite, Allan Hills (ALH) 84001. The 
4. 5 -billion-year- old meteorite contains a complex 
mineral assemblage that some believe is evidence of 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



possible relic life on Mars. For life to evolve in any 
geologic environment, water must be present. The 
early Martian atmosphere was apparently very dif- 
ferent from the present-day one and may have 
allowed liquid water to exist on the surface of the 
planet. A way to trace the history of water on Mars 
is through the isotopic composition of hydrogen. 
The hydrogen isotope composition of the present- 
day Martian atmosphere is enriched in the heavy 
isotope deuterium by a factor of 5.2 (<5D = 4200 per 
thousand (%o) relative to mean terrestrial ocean 
water). This value is considerably higher than the 
values observed in any terrestrial environment (5D 
= -300 %o to +100 %o). The deuterium enrichment 
in the Martian atmosphere is attributed to isotopic 
mass fractionation associated with the loss of 
hydrogen to space through time. Measuring the 
hydrogen isotope composition of Martian mete- 
orites of different ages, therefore, could provide 
information on the history of water loss on Mars. 

Boctor and coinvestigators Jianhua Wang, Conel 
Alexander, and Erik Hauri at the Department of 
Terrestrial Magnetism used the ion microprobe to 
determine the hydrogen isotope composition of 




Fig. 3. This is a zoned carbonate globule from Martian mete- 
orite ALH 84001. Magnesium-rich layers (dark gray) alternate 
with magnesium-poor, iron-rich layers (white to light gray). 



the mineral phases in ALH 84001. The investiga- 
tion showed three water-bearing phases: phos- 
phate (5D = +166 to +733 %o), carbonate (5D = 
+165 to +1165 %o), and feldspathic glass (<5D = 
+1073 to +1748 %o). The isotopic compositions of 
the three phases showed that the water is extrater- 
restrial, confirming the presence of indigenous 
water in the oldest known Martian meteorite. 

The conventional explanation for the high <5D val- 
ues observed in the carbonates and glass is their 
interaction with hydrothermal fluids that equili- 
brated with the Martian atmosphere. However, the 
researchers found the highest 5D values were in the 
glass that formed by impact melting at a pressure of 
about 4 x 10 5 atmospheres. This result raised the 
possibility that the deuterium enrichment in the 
glass is due to devolatilization and to preferential 
loss of hydrogen during impact. The scientists 
measured the <5D in impact-melted feldspathic glass 
(SD = +1612 to +2757 %o) and mafic glass (5D = 
+2023 to +2901 %o) from another Martian mete- 
orite, EETA 79001. This meteorite was shocked at 
pressures of 6 x 10 5 to 8 x 10 5 atmospheres, which 
was higher than the pressure that ALH 84001 
experienced. The results showed a positive correla- 
tion between <5D values and the shock pressure. 

Any fractionation process associated with water 
loss by devolatilization will produce an inverse cor- 
relation between water content and deuterium 
enrichment. The researchers observed this kind of 
correlation in ALH 84001. The estimates of the 
initial water content of the glasses from ALH 
84001 needed to produce the range of <5D values 
(+970 to +1650 %o) are not unusual for feldspathic 
melts under pressure. These calculations suggest 
that hydrogen loss by impact may have contributed 
significantly to the high deuterium enrichments in 
the impact glasses in both meteorites studied. 
These results imply that when using hydrogen iso- 
tope data from shocked meteorites to infer the his- 
tory of water on Mars caution should be exercised. 

Francis (Joe) Boyd 

Joe Boyd joined the Geophysical Laboratory staff 
in 1955 to conduct high-pressure experiments. 
One of his many contributions since then includes 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 




o 



L Lou 

F Finsch 

FS Frank Smith 

K Kimberley 



Fig. 4. This map of southern Africa shows the Kaapvaal craton 
with important kimberlites and kimberlite clusters. 



the development of a high-pressure apparatus 
called the Boyd-England device. This instrument 
has allowed scientists worldwide to determine crit- 
ical pyroxene-garnet phase relations — essential 
data for estimating the depth at which mantle 
rocks originate. More recently, with fellow Staff 
Member Yingwei Fei, Boyd created the 
cubic-anvil apparatus. With a pressure range from 
5 to 25 GPa, this equipment allows scientists to 
conduct phase studies with large-volume samples. 

Although Boyd officially retired in 1996, he 
continues to be an active researcher at the lab. 
He is well known for his other petrologic work on 
the nature and structural history of the crust and 
mantle. He is one of the world's leading experts 
on the mantle root of the Kaapvaal craton in 
southern Africa. 

Cratons are the kernels on which continents grow. 
They are much older and deeper than the neigh- 
boring crust and mantle. The Kaapvaal craton is 
some 3.5 billion years old. At 200 kilometers deep, 
it is well below the crust-mantle boundary. To 
study it, Boyd gathers and analyzes fragments of 
mantle wall rocks contained in diamond-bearing 
volcanic breccias called kimberlite that erupted 
onto the southern African surface millions of years 
ago. (The "pipes" through which the kimberlite 
erupted are now actively mined for diamonds.) 
Each fragment of mantle rock contains a chemical 



signature that tells its depth, age, and chemical 
history. By piecing together the fragments from 
different locations, Boyd and his colleagues are 
learning about the Kaapvaal craton's early forma- 
tion. This information can be applied to cratons in 
other parts of the world. Boyd is collaborating 
with Russian scientists, for example, to determine 
the similarities and differences between the crust 
and mantle forming the Kaapvaal craton with that 
forming the Siberian Platform. One of the 
long-term goals of these studies is to learn how the 
Earth's first early crust formed — a crust that pre- 
sumably preceded even that of the Kaapvaal and 
other ancient cratons around the world. 

George Cody 

The blend of organic chemistry and geology can 
address a broad range of scientific questions — from 
understanding the processes of oil and gas genera- 
tion to solving the mystery of the origin of bio- 
chemistry as it emerged from the molecular chaos 
of the primitive Earth. George Cody is an organic 




Fig. 5. The molecular tapestry of 40-million-year-old wood is 
shown in this high-resolution x-ray image acquired with the 
scanning transmission microscope at the National 
Synchrotron Light Source. The spatial resolution of the image 
is 50 nm and sample thickness is 150 nm. Contrast is based 
on the distribution of a specific type of carbon, and this pro- 
vides a high-resolution chemical "map" of carbon chemistry. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



geochemist whose research focuses on devising a 
unified understanding of the controls on organic 
reactions within the solid Earth. He explores the 
roles that temperature, pressure, time, fluid compo- 
sition, and mineral catalysis play in controlling 
organic reactions over time. Understanding these 
processes is a prerequisite to investigating larger 
issues that tie together the biological, physical, 
organic, and inorganic world of our planet. 

The mechanisms that govern natural organic syn- 
thesis and reactions are not restricted to Earth, 
however. The presence of significant quantities of 
organic molecules found in certain types of mete- 
orites indicates that the range of viable environ- 
ments for organic synthesis is extremely broad. In 
collaboration with others at Carnegie, Cody is 
working on questions pertaining to the extent of 
organic synthesis within the presolar nebula and 
the synthesis and reaction during the subsequent 
planetary accretion. His specific focus is to charac- 
terize the extraterrestrial organic matter within 
carbonaceous chondritic meteorites. If organic 
synthesis and reaction are necessary for the emer- 
gence of life, then the range and limits of organic 
stability and reaction need to be defined to set cri- 
teria for determining the probability of life on 
other planets and beyond our solar system. To 
study organic chemistry in this context, Cody has 
joined with others at Carnegie to form one of the 
first groups in NASA's Astrobiology Institute. 

A wide range of analytical methods is required to 
study organic molecules in complex systems. Over 
the past several years Cody has worked on a partic- 
ularly promising device that uses a one-of-a-kind 
soft x-ray transmission microscope based on a syn- 
chrotron source. He has been using this instrument 
to characterize the chemistry of cell wall mem- 
branes in plants and to follow the evolution of the 
chemical differentiation over geologic time as these 
materials transform into fossil fuels. 

Cody also led the effort at the Geophysical 
Laboratory to obtain a solid-state nuclear magnet- 
ic resonance (NMR) spectrometer — an instrument 
used by scientists at both the Geophysical Lab and 



the Department of Terrestrial Magnetism at the 
Broad Branch Road campus. Solid-state NMR has 
recently evolved into one of the most versatile and 
powerful tools in solid-phase chemistry. The new 
equipment is used to address fundamental ques- 
tions in organic geochemistry as well as questions 
in many other ongoing research areas. 

Ronald Cohen 

The Geophysical Laboratory has a long and dis- 
tinguished history of determining the stability and 
physical properties of materials experimentally. 
This work continues today. The materials investi- 
gated include Earth's minerals, materials that form 
the other planets, those used in high technology, 
and those that are interesting because of the prob- 
lems they pose to physics and chemistry. One goal 
of this research is to understand what the underly- 
ing physics is that gives rise to the materials' 
behavior. Cohen and his research group look at 
the problem by starting with electrons and nuclei; 
they try to predict and understand mineral and 
material behavior using fundamental physics. 

Three major projects are currently under way in 
Cohen's lab. The first explores the question: How 
do transition metal compounds behave at high 
pressures? Whereas electronically simple com- 
pounds like MgO and Si0 2 are well understood 
and their properties can be predicted quite accu- 
rately, transition metal oxides such as FeO are at 
the frontier of solid-state physics and are poorly 
understood. Experiments have not yet been able to 
clarify the properties and physical origins of the 
behavior of FeO. At high pressures and tempera- 
tures (approximately 100 GPa and 1000 K), a 
NiAs-type structure forms. The reanalysis of the 
experimental data shows that this product is most 
likely a polytype of NiAs with anti-NiAs struc- 
tures (with Fe on the Ni or As sites respectively). 1 
Interestingly, the researchers predict the NiAs part 
to be metallic, and the anti-NiAs part to be insu- 
lating. Since this phase may form in the deep 
Earth near the core-mantle boundary, this behav- 
ior could be very important in helping control the 
variations in the Earth's magnetic field. 



Mazm, 1. 1, Y. Fei, R. Downs, and R. E. Cohen, Possible polytropism in FeO at high pressures, Am. Mineral. 83, 45 1 -457, 1 998. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



Currently, Steve Gramsch, a CHiPR fellow, is try- 
ing to understand possible high-spin low-spin and 
metal insulator transitions in the rock salt (NaCl) 
structure of FeO. He is applying a newly developed 
method, which includes local electronic correla- 
tions, and finds that with increasing pressure a 
metal insulator transition occurs before a high-spin 
low-spin transition. This previously had been found 
theoretically with more conventional methods. 2 

In the second area of research, Cohen is working 
on materials used in high technology. In particu- 
lar, he is trying to understand piezoelectricity in 
ferroelectric perovskites. These materials are used 
in sonar and medical imaging as well as in 
dielectrics and nonvolatile computer memories. 
Postdoctoral associates Henry Fu and Sergei 
Stolbov are working with Cohen to understand 
the large strains found in a new class of single- 
crystal piezoelectrics that will revolutionize the 
above applications. 

Finally, active research is also under way in Cohen's 
lab to understand the thermoelastic, melting, and 
rheological behavior of minerals, metals, and com- 
pressed gases at high pressures and temperatures. 

Mikhail Eremets 

In 1999, Eremets joined the Geophysical Laboratory 
as a Senior Research Scientist. He is currently devel- 
oping a technique for obtaining electrical measure- 
ments at ultrahigh pressures. His goal is to study 
metallization and to find superconductivity in ele- 
mental and simple molecular substances at ultrahigh 
pressures. His recent work includes the metallization 
of xenon and search for conductivity of water, nitro- 
gen, and hydrogen at pressures above 2 Mbars. 

Mikhail Eremets began his scientific career at the 
Institute of High Pressure Physics in Troitsk, 
Moscow, as a Ph.D. student. Eventually, he 
became director of the high-pressure division. He 
has more than 20 years of experience in experi- 
mental studies of semiconductors and supercon- 
ductors using various optical techniques in a wide 




spectral range — from the submillimeter to the 
ultraviolet. Eremets is also interested in developing 
high-pressure techniques and has numerous arti- 
cles and patents on various instruments including 
the diamond-anvil cell, the Bridgman-type cell, 
and the piston-cylinder hydrostatic cell. 

In the past decade, Eremets has conducted experi- 
ments in laboratories in the United Kingdom, 
France, the Netherlands, Germany, and Poland. 
He has studied semiconductors and other materi- 
als at high pressures in combination with high 
magnetic fields and low temperatures. 

Eremets is particularly interested in diamond and 
closely related boron nitride (BN). He studied 
optical properties of cubic BN in the Laboratory 
for Solid State at the University of Paris-6. 
Working as a fellow at the National Institute for 
Research of Inorganic Materials (NIRIM) in 
Tsukuba, he performed experiments on the laser 
heating of cubic BN. These experiments yielded 
numerous results on a mechanism of first-order 
phase transformation and a phase diagram of BN. 
During these studies, he discovered boron nitride 
nanotubes, which are similar to the known carbon 
nanotube, but have different physical properties. 



2 Cohen, R. E., 1. 1. Mazin, and D. G. Isaak, Magnetic collapse in transition metal oxides at high pressures: implications for the Earth, Science 275, 654-657, 1997. 

Cohen R. E., Y. Fei, R. Downs, 1 ,1, Mazin, and D. G. Downs, Magnetic collapse and the behavior of transition metal oxides: FeO at high pressures, in High-Pressure Materials Research, 
Materials Research Society Proceedings, Vol. 499, R. Wentzcovitch, R J. Hemley, W. j. Nellis, and P. Yu, eds„ 1998. 



;arnegie institution 



YEAR BOOK p8—pp page 8p 



In the last few years, Eremets has turned his atten- 
tion to the study of the electrical properties of sub- 
stances at very high pressures. This is an essential, 
intrinsic area for high-pressure physics because 
under compression all substances ultimately become 
metals. However, electrical measurements in a dia- 
mond-anvil cell are challenging. Few experiments 
have been carried out and in those that have, the 
pressure was limited to 1 Mbar. Eremets, though, 
resolved numerous experimental difficulties in the 
preparation of an insulating gasket and electrodes. 
In collaboration with Japanese colleagues, he carried 
out studies on optical and electrical properties of 
sulfur at pressures up to 1.5 Mbar, during which for 
the first time sulfur was metallized and supercon- 
ductivity was found in it. This work was done at 
Osaka University in Japan, where Eremets worked 
as a visiting professor between 1995 and 1998. 
During that time, he further developed electrical 
measurements and pushed the pressure limit up to 
2.2 million atmospheres. He succeeded in the met- 
allization of Csl and found superconductivity in it. 
This high-pressure experiment was performed in 
combination with millikelvin temperatures and high 
magnetic fields. With the Japanese scientists, he 
also transformed oxygen to metals with supercon- 
ductive properties. 

YlNGWEI FEI 

A major goal of penological, geochemical and 
geophysical research is to completely describe the 
Earth's interior — from the crust to the core — to 
understand the physical and chemical conditions 
of the planet over time. Recent advances in high- 
pressure techniques allow scientists to explore the 
deep interiors of the Earth and other planets via 
simulations. Yingwei Fei is an expert in using 
high-pressure devices such as the piston-cylinder, 
the multianvil apparatus, and the diamond-anvil 
cell to simulate the high pressure and temperature 
conditions of planetary interiors. The multianvil 
apparatus allows scientists to simulate conditions 
ranging from 5 to 27 GPa. (The larger number is 
equivalent to a depth of 750 kilometers in the 
Earth, which is the uppermost part of the lower 
mantle.) While the diamond-anvil cell allows 
scientists to reproduce conditions as deep as the 




inner core, the multianvil apparatus is ideal for 
scientific investigations that require the analysis of 
relatively large samples to provide accurate phase 
equilibrium data. 

One particularly vexing problem for earth scien- 
tists is the makeup of the Earth's core. Iron cer- 
tainly is a major part; but what other elements are 
there? It has been proposed that sulfur (S), carbon 
(C), and oxygen (O) are the lighter alloying ele- 
ments that reside there. Fei and postdoctoral fel- 
low Jie Li are conducting experiments to investi- 
gate the nature of the core's lighter elements. 
Their experiments with the multianvil apparatus 
and the diamond-anvil cell have produced phase 
transformation and melting relations in the Fe-O- 
S-C system. This is an important step in under- 
standing how these elements interact at high pres- 
sures and temperatures. 

Fei and colleagues are also investigating the role of 
water and potassium in Earth's deep geological 
processes and the fate of subducted basaltic crust 
in the lower mantle. A subducted slab of oceanic 
crust contains significant amounts of water and 
potassium. What happens to the hydrous and 
potassium-bearing minerals at such depths? Many 
believe that hydrous phase transformations in sub- 
ducted slabs play a large role in mantle processes, 
including magma generation, water recycling, and 
possibly the occurrence of deep-focus earthquakes. 
With the goal of elaborating these phase changes, 



CARNEGIE INSTITUTION 



page^0 YEAR BOOK p8~pp 



Fei focuses on determining the stability fields of 
several dense hydrous magnesium silicates in the 
lower mantle. Fei and postdoctoral fellow Jiirgen 
Konzett conducted a series of high-pressure exper- 
iments to address transport and storage of potassi- 
um in the Earth's upper mantle and transition 
zone. Postdoctoral fellow Wenjie Jiao and Fei, in 
collaboration with Department of Terrestrial 
Magnetism Staff Member Paul Silver, are devel- 
oping a new multichannel acoustic emission data 
collecting system to detect acoustic emissions at 
high pressures and temperatures. This new system 
will allow them to test proposed physical mecha- 
nisms of deep earthquakes. 

Much of what scientists learn about our Earth can 
be applied to other planets. Fei is collaborating 
with Research Scientist Connie Bertka in investi- 
gating the internal structure of the planet Mars. 
Since there is no seismic data for Mars, scientists 
must rely on models and high-pressure and tem- 
perature experiments. Fei and Bertka are develop- 
ing a model of the Martian interior that starts with 
a chemical composition derived from Martian 
meteorites. On the basis of recent geophysical data 
from Mars Pathfinder, the two researchers found 
that CI chondrite accretion models are not suffi- 
cient to explain the formation of Mars and the 
other terrestrial planets. 

Marilyn Fogel 

A vast reservoir of carbon lies beneath the Earth's 
surface. It is composed of organic material millions 
of years old that has a mass many times larger than 
that of all living animals and plants combined. It is 
critical to us because it is the source of all of our fos- 
sil fuels — oil, gas, and coal. Carbon is also critical 
because within it, and in the organic molecules that 
give rise to it, are the keys to understanding the bio- 
logical and geological evolution of our planet. 
Understanding the coevolution of biology and geol- 
ogy is essential for management of our resources and 
predictions of climate change in the next century. 

Fogel's aim is to unlock the secrets within the 
Earth's carbon record through a unique combina- 
tion of methodologies and techniques. She applies 



advanced biochemical, isotopic, and spectroscopic 
techniques — some borrowed from the medical 
community — to learn how and why biochemicals 
survive and transform into other molecules on the 
Earth's surface to eventually become part of the 
carbon reservoir below. She is interested to learn, 
for example, how carbohydrates make up such a 
large fraction of the organic matter in geological 
samples, when for years it was believed that carbo- 
hydrates were destroyed early in the decay process. 
She wonders how nonbiological complexes of car- 
bohydrates with proteins and nucleic acids become 
structurally complex and stable geopolymers that 
withstand the test of time. To investigate such 
puzzles, her work straddles the territory between 
geochemistry and molecular biology. 




Fogel is also interested in studying past global 
change by reconstructing ancient environments 
using tools of isotopic analysis. Her rationale 
begins with the dictum "You are what you eat." 
An organism's tissues retain the nitrogen, carbon, 
and oxygen isotopic signatures of its diet and envi- 
ronment. These signatures are retained over mil- 
lions of years in fossils, particularly in shell or 
tooth fragments, and can be measured in the labo- 
ratory. Fogel has analyzed ancient emu eggshell, 
for instance, to learn how the practice of 
large-scale burning by ancient humans in the 
Australian Outback has altered the climate on a 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page pi 



continental scale. Learning how such ancient envi- 
ronments have been changed by humans can help 
scientists, better understand how humans now and 
in the future alter the global landscape. 

Fogel is currently working in a new direction with 
fellow Staff Members George Cody, Douglas 
Rumble, and Bob Hazen. They and others at the 
Geophysical Laboratory are members of NASA's 
Astrobiology Institute, which is involved in studies 
searching for evidence of early forms of life on 
Earth, on other planets, and outside our solar system. 

John Frantz 

John Frantz is interested in the investigation of the 
chemical structure of amorphous materials, such as 
silicate melts and aqueous fluids, as they pertain to 
processes involving heat and mass transfer in the 
terrestrial planets. As the Earth and neighboring 
terrestrial planets continue to cool, materials are 
constantly recycled throughout the crust and man- 
tle, resulting in chemically diverse rock composi- 
tions. Since amorphous materials are the primary 
agents in recycling, it is necessary to understand 
their chemical structure and associated physical 
properties to understand the processes controlling 
planetary evolution. In recent years, Frantz has 
investigated the chemical structure of both silicate 
melts and hydro thermal fluids. 

Frantz has also developed a furnace assembly, 
which permits for the first time the routine study 
of polymerization of silicate tetrahedra to tempera- 
tures above 1600°C at atmospheric pressure using 
Raman spectroscopy. He and Bjorn Mysen have 
successfully used this technique to investigate the 
structure of silicate melts involving alkalis, alkaline 
earths, and aluminum. 

More recently Frantz's interests have focused on the 
structure of hydrothermal fluids. His experiments 
currently involve supercritical fluids using Raman 
spectroscopy in conjunction with hydrothermal 
optical pressure vessels. He designed and built an 
optical cell fitted with diamond windows suitable 
for in situ measurement of the Raman spectra of 
fluids to 600°C and 4000 bar for this work. 




Steel Gasket 



Platinum Liner 



Vapor Bubble 



Aqueous Fluid 



Fig. 9. This is a view of aqueous magnesium sulfate solution 
shown through a microscope in the heated diamond cell. 



Frantz is also investigating supercritical fluids con- 
taining both water and carbon dioxide — a vital 
study since carbon dioxide is a major component of 
natural hydrothermal fluids. As part of this project, 
he successfully developed a methodology by which 
he can directly study CO2-H2O binary fluids in situ 
using Raman spectroscopy. He is also studying the 
stability and complexing of salts of aliphatic acids 
in hydrothermal fluids; salts might be important 
agents for mass transport since they may exist 
metastably for significant periods of time. 

Over the next two or three years, Frantz hopes to 
conclude these studies and change his research to 
in situ monitoring and theoretical modeling of 
natural hydrothermal fluids at oceanic ridges. As a 
first step in this new direction, he is developing an 
instrument to measure the hydrogen fugacity of 
the high-temperature fluids in these environments. 

Alexander Goncharov 

Alexander Goncharov has been working with Staff 
Members Ho-kwang Mao and Russell Hemley for 
almost six years to develop methods in optical 
spectroscopy for ultrahigh-pressure research. 
Optical spectroscopy is one of the most informa- 
tive techniques for ultrahigh-pressure studies. Its 




CARNEGIE INSTITUTION 



page^ I YEAR BOOK p8~pp 



importance arises from the power it has to study a 
wide variety of phenomena, and the transparency 
of the high-pressure cell's diamond windows over 
a wide spectral range. Optical methods are unsur- 
passed in many cases, such as studying low-Z con- 
taining materials, disordered materials, phase tran- 
sitions, pressure calibration, and lattice dynamics. 

Goncharov has built a variety of new optical 
instruments including GL's infrared (IR) facility at 
the U2 beamline of the National Synchrotron 
Light Source (NSLS), Brookhaven National Lab; 
GL's low temperature-ultrahigh pressure system 
for Raman and infrared experiments; and 
Raman/fluorescence spectrometers at the XI 7C 
beamline of the NSLS and Sector 13 of the 
Advanced Photon Source. These contributions 
have made it possible to routinely perform numer- 
ous optical experiments at ultrahigh pressures. 

Goncharov, in collaboration with Staff Members at 
GL, conducted experiments to examine the behav- 
ior of simple molecular substances at megabar pres- 
sures. Among the most exciting results was the dis- 
covery of a new class of excitations in orientationally 
ordered low- temperature phases of solid hydrogen 
and deuterium. Another breakthrough was the first 
unambiguous experimental evidence of the exis- 
tence of nonmolecular high-pressure modification 
of ice with symmetric hydrogen bonds. 

Recently, Goncharov was involved with the 
upgrade of the U2 beamline. This substantially 
improved the performance in the far-infrared 
spectral range and has made it possible to measure 
far-infrared spectra in the megabar pressure range. 
Goncharov is also working on a new design for a 
laser spectrometer with holographic optics. 

Robert Hazen 

Robert Hazen worked with former Staff Member 
Larry Finger for two decades to establish the field 
of high-pressure crystallography — the study of 
crystal structures at high pressure. Their work has 
led to a deeper understanding of compression 
mechanisms in solids, as well as identification of 
numerous high-pressure phase transitions in min- 



erals and related compounds. They have also pre- 
dicted a variety of new structures, including miner- 
al-like compounds that may have applications as 
ceramics, abrasives, and materials for trapping and 
isolating the radioactive atoms found in nuclear 
waste. When they began, their high-pressure work 
was groundbreaking. Today, researchers around 
the world use their techniques. 

Hazen has turned his attention to a new area — the 
study of high-pressure organic synthesis deep with- 
in the Earth. Carbon, the central element of life, 
exists in high-pressure and high- temperature envi- 
ronments. Hazen, in collaboration with other Staff 
Members at the lab — George Cody, Marilyn Fogel, 
Hatten Yoder, and Russell Hemley — is conducting 
experiments to examine the pathways by which the 
simplest organic compounds, like carbon, may have 
combined deep in the Earth's ancient crust to form 
the molecules essential to life. Among the most 
exciting potential outcomes of these studies would 
be the discovery of the evolutionary sequence of 
chemical reactions leading to the origin of life. 

The organic synthesis work is complemented by 
studies of carbon and nitrogen isotopes preserved 
in fossils. Hazen, working with the Department of 
Terrestrial Magnetism's ion microprobe facility 
and with paleontologists at the Royal Ontario 
Museum in Toronto and at Harvard University, is 
examining extraordinary specimens in which origi- 
nal atoms of ancient life are preserved. These stud- 
ies hold the promise of understanding biochemical 




■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp page ^J 



aspects of organisms that became extinct hundreds 
of millions of years ago. 

During the last several years, Hazen has also been 
an advocate for the reform of science education, at 
both the K-12 and the undergraduate level. He 
helped write the National Science Education 
Standards introduced by President Clinton in 
1995, and has served on the Executive Board of 
the National Research Council's National 
Committee for Science Education and on advisory 
boards for NOVA, Encyclopedia Americana, and 
the National Science Resources Center. In 1997, 
he coauthored a book with Carnegie's president, 
Maxine Singer, titled Why Arerit Black Holes 
Black?: The Unanswered Questions at the Frontiers of 
Science. Intended to inform and intrigue science 
enthusiasts beyond the academic sphere, this work 
examines 14 of the most compelling mysteries fac- 
ing scientists today. It is the latest of a long list of 
books about science that Hazen has written. 

Russell J. Hemley 

Rus Hemley continues to explore the remarkable 
behavior of materials when they are subjected to 
extreme pressures, up to and beyond 300 GPa 
(3 Mbar), at temperatures ranging from millikelvins 
to above 5000 K. It is becoming increasingly clear 
that such studies have implications that span the 
physical sciences, from fundamental chemistry and 
physics, earth and planetary science, to materials 
science and high technology. Research within 
Hemely's group during the past year has continued 
to uncover new phenomena in molecular materials 
at very high pressures. For instance, the researchers 
pinpointed the transition pressure of H 2 0-ice from 
its normal molecular form to its high-density non- 
molecular state. They also found unusual quantum 
mechanical phenomena associated with this transi- 
tion. These experiments, combined with related 
studies of hydrogen and methane, reveal the nature 
of materials that comprise the large planets of the 
solar system. Some of the group's other high- 
pressure studies of molecular systems include the 
study of superconductivity in organic conductors, 
and in situ monitoring of the organic reactions 
under hydrothermal conditions. 



Hemley's group is also focusing on the oxides, sili- 
cates, and metals that form major constituents of 
our planet. Long thought to be a solved problem, 
the high-pressure behavior of silica continues to 
produce new surprises. Important advances have 
been made in both theory and experiment, includ- 
ing the evidence for new forms of silica that may 
exist deep within the mantle. Recent experimental 
data were used to develop a theory for silica's major 
high-pressure transition at 50 GPa; this provides a 
basis for evaluating the geophysical signature of 
free silica in the lower mantle. The pressure depen- 
dence of the stability of quartz — the common form 
of silica found in the Earth's crust — was tracked 
using light-scattering techniques. The experiment 
revealed the origin of the pressure-induced trans- 
formation of the material to a dense glass. The 
group had discovered this phenomenon in the 
1980s. New x-ray diffraction and spectroscopic 
studies have uncovered novel phenomena in iron- 
bearing oxides and silicates, including electronic 
spin transitions and magnetic collapse. These latter 
studies also include the first direct measurements of 
the elasticity, texture, and flow properties of iron — 
crucial information for understanding seismological 
observations of the Earth's core. 

Most of the discoveries mentioned above were 
made possible by the group's ability to continually 
develop new techniques in high-pressure experi- 
mentation. Among the most important have been 
those involving high-intensity synchrotron radia- 
tion, such as new techniques for x-ray diffraction 
of materials at pressures and temperatures found at 
the Earth's core, x-ray fluorescence spectroscopy, 
and new high-pressure inelastic x-ray scattering. 
In fact, the group has launched a major program to 
build a high-pressure synchrotron x-ray facility at 
the Advanced Photon Source, Argonne National 
Laboratory to carry out these studies in a dedicated 
fashion. This new facility offers many opportuni- 
ties and will complement the dedicated high-pres- 
sure synchrotron beamlines the group uses at the 
National Synchrotron Light Source at Brookhaven 
Lab, including the just-completed dedicated high- 
pressure synchrotron infrared beamline. This syn- 
chrotron work also complements technical 
advances in other areas. Some examples are high- 
pressure magnetic susceptibility and electrical con- 



CARNEGIE INSTITUTION 



page 94 I YEAR BOOK p8~pp 



ductivity techniques for investigating new super- 
conductors and novel metals, and the development 
of new synthetic diamond anvils for compressing 
larger samples, reaching higher pressures, and per- 
forming an even wider range of measurements. 

T. Neil Irvine and Hatten S. Yoder, Jr. 

Metasomatic rocks are formed when an original 
rock is transgressed by mineralized solutions (liq- 
uid and/or vapor) that react in passing to produce 
material of new composition. Commonly the new 
rock replaces the original on an approximately vol- 
ume-for-volume basis. Metasomatic rocks are 
widespread in the Earth's crust and upper mantle, 
and they frequently are exotic in mineralogy and 
texture. Many feature monomineralic zones; some 
are economically important as ore deposits; almost 
all are problematic in origin. The nature and ori- 
gin of the fluids and the mechanics of the reaction 
processes are especially difficult to define. 

The Skaergaard intrusion is situated in East 
Greenland, just north of the Arctic Circle. It solid- 
ified from a body of magma (molten rock) roughly 
10 km long, 7 km wide, and 3.5 km thick. The 
intrusion is renowned for spectacular primary layer- 
ing, and it is by virtue of this layering that the sec- 
ondary metasomatic bodies considered here are 
recognized (below). These bodies are mostly 
anorthosite, a white rock composed largely of the 
mineral plagioclase (a solid solution of CaAl 2 Si 2 8 
and NaAlSi 3 Og), but many have thin basal rims of 





o 



: ig. I I . Metasomatic anorthosite formed by replacement of 
layered gabbroic troctolite in the Skaergaard intrusion is 
shown here. A thin, dark rim of peridotite follows the lower 
edge of the anorthosite. The layering was almost horizontal 
originally, and all the rocks have been tilted to the right. 



peridotite, a brown rock rich in olivine (a solid 
solution of Mg 2 Si0 4 and Fe 2 Si0 4 ). The anorthosite 
bodies typically wend through their layered host 
rock without appreciably displacing its stratifica- 
tion, this being prime evidence that volume-for- 
volume replacement, and the bodies are ideal for 
study because they are well exposed, convenient in 
size (1-10 m long), and distinctively simple. It is 
reasonably established that the host rock (called 
gabbroic troctolite) originated by sedimentation of 
plagioclase and olivine crystals on the floor of the 
original magma body as it cooled and solidified, 
and that the metasomatism was imposed as the 
pore liquid between the accumulated crystals grad- 
ually solidified. Water was evidently important to 
the metasomatism, because the anorthosite plagio- 
clase contains tiny, H 2 0-rich vapor bubbles. 

The metasomatism is further explored here 
through a new experimental observation that addi- 
tion of H 2 to olivine-plagioclase cotectic melts in 
a model system Mg 2 Si0 4 -CaAl 2 Si 2 8 -Si0 2 strong- 
ly shifts their compositions toward plagioclase. 

The diagram below illustrates schematically how 
such shifting might induce mineral exchange reac- 
tions in troctolite, and the drawing (right) inter- 
prets the Skaergaard metasomatic processes using 
these reactions. The dry liquid, L°, is portrayed as 
original pore liquid being gradually filter pressed 
upward through the layered crystal pile by com- 



». ^^-'Dry' liquidus 

Olivine "^^^L 

Cooling by ** 
plagioclase! 
olivine resorption 




Cooling Plagioclase 
^by actual ** 

/ heat loss -•- "" 



Cotectic shifted 
by H 2 gain 
Cotectic shifted 




Heating by 
plagioclase 
olivine precipitation 



'Wet' 

iquidus 



-Mg2Si04 -SiC>2 join 



CaAI 2 Si20 8 - 



Fig. 12. This image shows possible interactions of olivine-pla- 
gioclase cotectic liquids with troctolite (plagioclase-olivine 
rock) from gains or losses of H 2 and heat, based on newly 
defined relations for the system Mg 2 Si0 4 -CaAl2Si208-Si0 2 -H 2 
at 5 kilobars pressure. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 95 




Fig. 1 3. Physical processes are inferred for the formation 
of Skaergaard metasomatic anorthosite and peridotite in 
this diagram. 



paction. Hydrous liquid L 1 forms in the lower part 
of the intrusion where H 2 entering along frac- 
tures from the floor or wall rocks interacts with the 
first L° it encounters; then, being the more fluid 
and buoyant liquid, L 1 preferentially rises along 
permeable channels to local sites of metasomatism 
near the top of the crystal pile. Metasomatic 
anorthosite forms where L 1 dehydrates by boiling; 
the peridotite rim at its base develops concurrently 
below a density graded L'/L° diffusive interface. 

Ho-kwang (Dave) Mao 

Ho-kwang (Dave) Mao joins his principal collabo- 
rator and fellow Staff Member, Russell Hemley, in 
the belief that high-pressure research is reaching a 
turning point and may soon emerge as a dominant 
branch of modern science. Mao is a pioneer in 
ultrahigh-pressure technology. He has repeatedly 
demonstrated how innovative high-pressure exper- 
imentation has exposed new scientific phenomena 
critical to solving problems in physics and the 
planetary sciences. As the field grows, he foresees 
that it will also add new dimensions to research in 
chemistry, the material sciences, and technology. 



Mao is a principal investigator at the Center for 
High Pressure Research (CHiPR) and director of 
the newly established high-pressure collaborative 
access team at the Advanced Photon Source at 
Argonne National Laboratory. Mao is an expert on 
research using multimegabar techniques, especially 
with the diamond-anvil cell. He and former col- 
league Peter Bell first reached 1 megabar static 
pressure in 1976, an advancement that doubled the 
previous pressure limit. Three years later, Mao and 
Bell became the first to compress hydrogen to solid 
form at room temperature. Mao and his colleagues 
have been steadily improving the multimegabar 
technique ever since, integrating it with methods of 
analysis such as synchrotron x-ray diffraction and 
infrared, Raman, and other kinds of spectroscopies. 
By 1990, the high-pressure researchers reached 1.8 
megabars and detected evidence of a transition to 
metallic hydrogen in the molecular form. 

Mao and his collaborators have made a myriad of 
discoveries about physical and chemical phenomena 
at high pressures, including pressure-induced amor- 
phization and crystallization and electronic and 
structural phase transitions, as well as discoveries 
relevant to planetary interiors. Several years ago, for 
example, Mao participated in an investigation of the 
core of Mars. With his colleagues, including 
Charles Prewitt and Yingwei Fei, he suggested that 
sulfur might be a possible light-element component 
of the Martian core. The year before, Mao and Fei 
raised the possibility that sulfur and oxygen could 
both be components of the Earth's largely iron core. 

Bjorn Mysen 

Bjorn Mysen is intrigued with the processes that led 
to the formation and evolution of the Earth. He is 
particularly interested in the physical chemistry of 
melting and crystallization, as well as in materials 
and energy transfer and transport processes in the 
interiors of the Earth and terrestrial planets. The 
interactions between molten silicate (magma), its 
crystalline equivalent, and water are central to his 
investigation; they influence the fundamental physi- 
cal and chemical processes within the Earth. 

At high pressure, water is released from silicate 
melts, altering the surrounding volume of fluid; 



CARNEGIE INSTITUTION 



page 96 I YEAR BOOK p8~pp 



■ 1 00 urn 1 



aqueous fluid 



Re gasket 




1 3C diamond 
(P-calibrant) 



O 






o 



Fig. 1 4. This is a photomicrograph of coexisting 
H 2 0-satu rated silicate melt and silicate-saturated 
bubbles of aqueous fluids taken in situ in the dia- 
mond-anvil high-pressure cell at 0.9 GPa and 9 1 0°C. 



this may govern the explosive nature of many vol- 
canic processes. These fluids also act as solvents 
for silicates, and thus function as principal agents 
to transport materials within the Earth. This 
transport also results in the enrichment of ele- 
ments that ultimately provide economically impor- 
tant ore deposits. Much of Mysen's research spot- 
lights a common link between the mixing behavior 
of solutions in silicate melts and in silicate-bearing 
aqueous solutions, and the transport properties, or 
rheology, of fluids and melts. 

Materials like these are measured in the lab by 
examining their structural features microscopically. 
This requires examining silicate melts and fluids at 
high pressures and temperatures comparable to 
those in the Earth's interior. Mysen uses these 
structural data to model the materials' thermo- 
chemical and transport properties. This in turn 
allows him to develop a framework to predict the 
melting, aggregation, ascent, and crystallization of 
the silicates melts and aqueous fluids. 



Charles T. Prewitt 

Charles Prewitt's research involves the synthesis 
and characterization of mineral analogs and new 
materials that are interesting to both geoscientists 
and materials scientists. Along with Staff 
Members Larry Finger and Robert Hazen, and 
Research Scientist Hexiong Yang, Prewitt main- 
tains and operates the Geophysical Laboratory's 
x-ray diffraction lab and, with the retirement of 
Finger in July 1999, has taken on an expanded 
role. Prewitt also uses synchrotron facilities in the 
U.S. and abroad for his work. He has several cur- 
rent research projects. 

Funds from the W. M. Keck Foundation were 
used to match a National Science Foundation, 
Division of Earth Sciences grant to purchase a 
Bruker CCD single-crystal x-ray diffractometer. 
Larry Finger and Prewitt were the principal inves- 
tigators. The instrument was delivered in October 
1998 and, after learning how to operate the equip- 
ment and reduce the data, a number of different 
scientists have used it for a variety of projects. The 
researchers are pleased with its capabilities and 
believe it will have a major impact on productivity, 
enabling scientists to perform experiments that 
would be difficult or impossible with the older dif- 
fractometers. The early operation of the instrument 
was aided substantially by a predoctoral fellow, 
Przemyslaw Dera, who is a graduate student at 
Adam Mickiewicz University in Poznan, Poland. 
Dera returned to Poland in March to complete his 
Ph.D. thesis and will return to Carnegie in January 
2000 as a postdoctoral fellow to continue working 
with the group. Other scientists who have used the 
equipment include Finger, Prewitt, Hexiong Yang, 
Jeff Post (Smithsonian Institution), Altaf Carim 
(Penn State University), and two summer interns, 
Kenneth Kehoe (University of Wisconsin) and 
Jason Nicholas (Franklin and Marshall College). 
Several papers based on data from the diffractome- 
ter have been submitted for publication, and several 
others are in preparation. 

Prewitt is also interested in research on hydrous 
magnesium silicates, particularly in the addition 
of components other than those found in the 
MgO-Si0 2 -H 2 system. High-pressure hydrous 



■ 



ARNEGIE INSTITUTION 



YEAR BOOK p8~pp page pj 



silicate phases have attracted much attention for 
the past 30 years because of the implications they 
have for the presence of water in the Earth's mantle 
and the effects they have on Earth processes. 
Previous studies on hydrous silicates were focused 
primarily on the MSH (MgO-Si0 2 -H 2 0) system, 
and a number of phases were identified and labeled 
as 10A, 3.65A, A, B, C, D, E, F, G, and superhy- 
drous B (the "alphabet phases"). Because the man- 
tle contains elements other than those in the MSH 



V/ 



V 



M ML 



Fig. 15.. This image shows the crystal structure of Phase D, 
MgSiiHjO^ The dark gray octahedra represent Mg0 6 and the 
light gray ones, Si0 6 . This material has the highest known 
pressure-temperature stability of any hydrous silicate and 
may be present as a mineral in Earth's lower mantle. 



system, Jiirgen Konzett, Charles Prewitt, and 
Hexiong Yang investigated more chemically com- 
plicated hydrous silicate phases synthesized at high 
pressures and temperatures using the multianvil 
apparatus. The synthesis and characterization 
include the following hydrous phases: 

M4 K-substituted K-richterite, K(KCa)Mg 5 Si 8 22 (OH) 2 
(15 GPa, 1400°C); 

Clinopyribole, Ko.96Ca1.56Na2.51Mg6.01Al1.12 SiuCh^OH);. 
(lOGPa, 1200°C); 

Hydrous phase (aenigmatite structure), Na2(MgsjoAlo/ts)Sis.9iOi8(OH)2 
(10 GPa, 1250°C); 



Na-phase X, (Nai.i6Ko.oi)(Mg,. w Alo., 4 )Si 2 07Ho.6s 
(10 GPa, 1250°C); 

K-phase X, Ki 5 4Mgi 93Si1.89O7H1.04 
(16 GPa, 1300°C) 

Identification and structure refinements of these 
phases not only provide researchers with insights 
into crystal chemistry of high-pressure hydrous 
silicates, they also expand the knowledge of deep 
Earth mineralogy. The table shows several new 
phases with structures related to Phase E, one of the 
major candidates to be actually present in the man- 
tle, but as yet not identified as a mineral. Addition 
of Fe 3+ results in structures with different unit cells 
and symmetries but similar structural components. 

Douglas Rumble III 

Oxygen isotope geochemistry is the single most 
powerful research tool available for the study of 
interactions between water and rocks. Water alters 
rocks by chemical reactions such as solution, replace- 
ment, and precipitation, and at the same time indeli- 
bly changes the rocks' oxygen isotope composition. 
Oxygen has three stable, nonradioactive isotopes — 
16 0, 17 0, and 18 0. Seawater, rainwater, glacier ice, 
groundwater, and extraterrestrial water each have 
distinctive and identifiable ratios of the isotopes. By 
measuring the oxygen isotope ratios in rocks and 
minerals, the sources and amounts of ancient waters 
long drained away can be estimated. 

Projects under way in Doug Rumble's laboratory 
accurately illustrate the wide applicability and 
power of oxygen isotope geochemistry. Rumble is 
analyzing oxygen isotopes in high-pressure miner- 
als from a continental collision zone in northern 
Kazakhstan. The samples are unique to the planet 
because they contain diamonds in a matrix of 
metamorphosed sediments rather than the more 
typical occurrence in volcanic rocks. Together with 



Phase 


S.G. 




Composition 


Synthesis 


E 


R3m 




Mg 2 .4oSi|2|0 6 H2 36 


16 GPa, I000°C 


Brown 


PSJmtnc 




Mg2.29Fe 3+ 0.60Si|.0|O 6 H 2 .|5 


14 GPa, I400°C 


Green 


P6,22, P6 5 22 


Mg 2 l3 Fe 3+ 59Si 870 6 H 2 52 


14 GPa, I400°C 


Dark green 


R32, R3m, 


R3m 


Mg|. 96 Fe + 0.87Si .63O 6 H 3 .05 


14 GPa, I400°C 



CARNEGIE INSTITUTION 



page ?8 I YEAR BOOK p8~pp 



geologists from the Tokyo Institute of Technology 
(TIT), Waseda University, Yokohama University, 
the Geological Survey of Japan, and Stanford 
University, Rumble participated in mapping and 
sampling diamond-bearing rocks of the Kokchetav 
massif in August 1999. Graduate students from 
Waseda and TIT are now analyzing the samples in 
Rumble's laboratory. The goal of the study is to 
identify the source of the diamond-containing 
rocks. The isotopic information will be used to 
understand how surface rocks can be subducted to 
depths of 125 kilometers, or more, and return to 
Earth's surface without losing their definitive sur- 
face characteristics. It should be possible to recon- 
struct ancient environmental conditions recorded 
by sediments before they were driven into the 
Earth's mantle by continental collision. 

NSF postdoctoral fellow Henry Fricke is using the 
ultraviolet (UV) laser oxygen isotope microprobe 
and other analytical techniques to investigate the 
record of ancient climate stored in dinosaur teeth. 
These methods work because the oxygen isotope 
ratio of rainwater is influenced by local climate. 
Animals drink the rainwater, which in turn influ- 
ences the oxygen isotopic composition of their 
growing teeth. A UV laser study of several small 
dinosaur teeth indicates that they grew rapidly, 
and may be used to study seasonal changes in tem- 
perature during the Cretaceous period. Analyses of 
dinosaur teeth from different localities in North 
America using conventional techniques indicate 
that temperatures were much warmer during this 
same time period, particularly in the polar regions. 

Richard Ash, NASA postdoctoral fellow, is study- 
ing meteorites with the UV laser oxygen isotope 
microprobe. He has found isotopic evidence of the 
effects of 4.5-billion-year-old ice that accumulated 
with the metallic and rocky components of mete- 
orites early in the history of the solar system. 
Continuing accretion from the solar nebula grew 
planetesimals big enough that the internal radioac- 
tive decay melted ice chunks. Liquid water perco- 
lated through the metal-rock mixture, altering the 
isotopic composition as it moved, and leaving 
behind a record that survived even the fiery flight 
through Earth's atmosphere. 



None of the projects would be possible without 
the use of state-of-the-art equipment, much of 
which must be crafted in-house. The infrared laser 
oxygen isotope probe was invented in this labora- 
tory by postdoctoral fellow Zach Sharp 10 years 
ago and an updated instrument remains in 
demand. The new UV laser oxygen isotope micro- 
probe was developed through the efforts of many 
researchers, including former German Science 
Foundation postdoctoral fellow Uwe Wiechert, 
former Carnegie fellows Ed Young and James 
Farquhar, and Rumble. The UV microprobe is 
opening up new research opportunities because of 
its capability for in situ, spatially resolved analyses. 

Viktor Struzhkin 

Viktor Struzhkin joined the Geophysical Lab's 
high-pressure group, led by Ho-kwang Mao and 
Russell Hemley, in October 1994. He started 
working with diamond-anvil cells on projects 
exploring superconductivity at extremely high pres- 
sures. This work was initiated by Yuri Timofeev, 
who is still an active collaborator in the effort. The 
experiments have been very successful — supercon- 
ductivity measurements were obtained for the first 
time on niobium at megabar pressures of 140 GPa 
and on sulfur at 155 GPa. Recent developments in 
instrumentation have improved the sensitivity of 
the technique substantially, allowing the measure- 
ment of superconductive magnetic signals from 
samples only 30 microns in diameter and a few 
microns thick. Recent successful measurements of 
sulfur to 230 GPa confirmed that this is the tech- 
nique of choice for multimegabar experiments. 
This method will allow researchers to explore novel 




CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page pp 



metallic phases of light elements that are funda- 
mentally and astrophysically important, partly 
because of their potential as high-temperature 
superconductors. One of these novel phases may be 
metallic hydrogen, which is widely believed to have 
a very high critical superconducting temperature. 
The experimental work recently received an added 
dimension — new developments in magnetic tech- 
niques, by Yuri Timofeev, to be used to study fer- 
romagnetic materials. Senior Research Scientist 
Mikhail Eremets, who recently arrived at GL, 
brought another technique for resistivity measure- 
ments. This method extends the possibilities for 
studies of superconductors and magnetic materials 
even further. 

Struzhkin is also involved with other synchrotron- 
based techniques recently developed at the 
Geophysical Laboratory, including those that probe 
the magnetic and electronic structure of metals and 
magnetic materials. These techniques were devel- 
oped in collaboration with the National Synchrotron 
Light Source at Brookhaven and the Advanced 
Photon Source at Argonne National Laboratory. 
Recendy, Struzhkin investigated the local magnetic 
structure of FeS and FeO with x-ray emission spec- 
troscopy. The high-pressure group's recent break- 
throughs in the creation and characterization of 
novel metals and superconductors are providing 
extraordinary opportunities that Struzhkin and col- 
leagues plan to pursue in their upcoming research. 

In addition to his other work, Struzhkin devotes a 
considerable portion of his research time investigat- 
ing simple molecular solids using spectroscopic tech- 
niques. He is a member of the team that discovered 
the symmetric form of ice. Synchrotron infrared 
spectroscopy was the main tool used to investigate 
the transition region in detail, and Struzhkin was 
responsible for the analysis of the data that revealed 
the underlying pressure-induced changes in ice. 

David Virgo 

Throughout his career, David Virgo's major field of 
concentration has been the use of crystal, chemical, 
and other structural information to characterize 
properties and processes in rock-forming minerals 



and silicate melts. His early work focused on inter- 
crystalline partitioning between coexisting feldspar 
phases in metamorphic rocks and on intracrystalline 
equilibria, namely the distribution of iron cations 
between crystallographically distinct sites in ferro- 
magnesian minerals. These initial interests remain a 
top priority in his research today. In a series of clas- 
sic studies, he has shown how Fe-Mg order-disor- 
der equilibria in pyroxenes and amphiboles can be 
used as a powerful means to determine 
temperature-time paths of metamorphic and 
igneous rocks on the Earth and the Moon. This 
interest has led him to projects using thermody- 
namic calibrations of heterogeneous phase equilibria 
between coexisting minerals in xenoliths entrained 
in basaltic and kimberlitic magmas to clarify the 
oxidation state of the Earth's upper mantie. An 
extension of these studies, to include the crystallo- 
graphic controls of Fe + and Fe + in lower mantle 
phases, aims at modeling the oxidation state of the 
lower mantle. Both these latter studies provided 
unique answers to fundamentally important ques- 
tions concerning the Earth's early evolution. 

Virgo also devoted a considerable portion of his 
research time to experimental studies of the struc- 
ture of silicate glasses and to the relationships 
between structure and derivative physical and 
chemical properties. He was an integral part of the 
extensive effort at the Geophysical Laboratory on 
silicate melt structure beginning around 1979, 
when he demonstrated how Mossbauer and 
Raman spectroscopic data can be used to deter- 
mine the cationic and anionic speciation in silicate 
glasses. In these pioneering studies, he advocated 
the concept of coexisting structural units in melts, 
a concept that at the time was not fashionable, but 
that today is in accord with the extensive body of 
spectroscopic data of silicate glasses and liquids. 

Virgo's current research concerns experimental 
studies of the iron oxidation mechanism in mag- 
matic hydrous minerals such as micas, amphiboles, 
and allanites. He believes that these studies will 
lead to a new magmatic geohygrometer. Thus far 
his work has led to important predictions regard- 
ing the water contents of Martian magmas, which 
in turn have raised questions concerning the possi- 
bility of prior existence of life on Mars. 



CARNEGIE INSTITUTION 



page IOO I YEAR BOOK p8~pp 



>oratory Personnel 



July 1 , 1 77o —June 



Research Staff Members 

Francis R. Boyd, Jr., Penologist Emeritus 

George D. Cody 

Ronald E. Cohen 

Yingwei Fei 

Larry W. Finger 1 

Marilyn L Fogel 

John D. Frantz 

P. Edgar Hare 2 

Robert M. Hazen 

Russell J. Hemley 

Wesley T. Huntress, Jr., Director* 

T. Neil Irvine 

Ho-kwang Mao 

Bjorn O. Mysen 

Charles T. Prewitf 

Douglas Rumble III 

David Virgo 

Hatten S. Yoder, jr., Director Emeritus 

Senior Fellows and Associates 

Peter M. Bell, Adjunct Senior Research Scientist 
Constance Bertka, Research Scientist, National 

Aeronautics and Space Administration (NASA) and 

Center for High Pressure Research (CHiPR) 
Nabil Z. Boctor, Research Scientist (NSF 

Astrobiologyf 
Mikhail Eremets, Senior Research Scientist (CHiPR 

and NSF) b 
Alexander Goncharov, Research Scientist (CHiPR) 
Jingzhu Hu, Research Technician (NSF) 
Jurgen Konzett, Swiss National Science Foundation 

Fellow 
Gotthard Saghi-Szabo, Research Scientist (Carnegie) 
Markus Schwoerer-Bohning, Beamline Scientist 

(Carnegie HPCAT) 7 
Jinfu Shu, Research Technician (CHiPR) 
Viktor Struzhkin, Research Scientist (CHiPR) 
Uwe Wiechert, Deutsche Forschungsgemeinschaft 

(DFG) Fellow 8 
Hexiong Yang, Research Scientist (Hazen Gift and 

NSF Grant)9 

Postdoctoral Fellows and 
Postdoctoral Research Associates 

Richard D. Ash, Carnegie Fellow and NASA 

Associate 10 
James Badro, CHiPR Associate 
Joakim Bebie, Carnegie and NSF Astrobiology Institute 

Fellow" 
Jay A. Brandes, Carnegie Fellow' 2 
Timothy R. Filley, Carnegie Fellow and Astrobiology 

Associate 
Matthew Fouch, Harry Oscar Wood Fellow' 3 
Henry C Fricke, NSF Associate 
Huaxiang Fu, ONR Associate'* 
Stephen A. Gramsch, CHiPR Associate 
Eugene A. Gregoryanz, CHiPR and NSF Associate' 1 
Oguz Gulseren, DOE Associate 
Yoshiyuki lizuka, CHiPR Associate"' 
Wenjie Jiao, Carnegie Fellow and NSF Associate' 
Jurgen Konzett, CHiPR Associate 
Jie Li, Grove Karl Gilbert Fellow' 
Zhen-Xian Liu, CHiPR Associate' 7 
Yanzhang Ma, NSF Associate 
Fredenc C. Marton, NSF Associate'" 
William Minarik, Carnegie Fellow and NSF 

Associate" 
Anurag Sharma, NSF Astrobiology Associate 10 
Sean Shieh, NSF Associate 5 
Maddury S. Somayazulu, Carnegie and Arizona 

State Fellow 
Mark A. Teece, Smithsonian Institution Research 

Associate 



Ji-anXu, NSF Associate 2 ' 
Hexiong Yang, Hazen Gift and NSF Associate 21 
Susan Ziegler, Carnegie Fellow and NSF Astrobiology 
Associate 22 

Predoctoral Fellows and Predoctoral 
Research Associates 

Charles Kevin Boyce, Harvard University 2 * 
Pamela G. Conrad, CHiPR Associate 25 
Subarnarekha De, Carnegie Fellow 26 
Przemyslaw Dera, CHiPR Associate 27 
Stefanie L. Kitchell, The Johns Hopkins University 2 ' 
Sebastien Merkel, NSF and CHiPR Associate 
Sean Shieh, Carnegie Fellow 26 

Summer Interns, Geoscience 
Program (NSF) 

Lora Armstrong, Montgomery Blair High School 

Alexander Berengaut, Montgomery Blair High School 

Emily Bloomfield, Cose Western Reserve University 

Stacia DeSantis, Dartmouth College 

Sarah Faulkner, Brown University 

Stephen Hadley, Union College 

Heather Hibbert, Princeton University 

Valerie Joe, State University of New York at Stony 

Brook 
Kenneth Kehoe, University of Wisconsin Eau-Claire 
George Maglares, Yale University 
Sarah Miller, Wellesley College 
Jason Nicholas, Franklin and Marshall College 
Xavier Noblin, Eco/e Normale Superieur de Lyon, 

France 
Christopher Noser, Carnegie Mellon University 
Beth Ann Parker, Huntingdon College 
William Pike, Carieton College 
Richard Praseuth, A/It. San Antonio College 
Bryan Wade Scott, Howard University 
Abigail Wasserman, Princeton University 
Kevin Wheeler, Brown University 

Supporting Staff 

John R. Almquist, Library Volunteer 
Andrew J. Antoszyk, Shop Foreman 26 
Maceo T. Bacote, Engineering Apprentice' 
Bobbie L. Brown, Instrument Maker 
Stephen D. Coley, Sr., Instrument Maker 
James B. Collins, Instrument Maker 
H. Michael Day, Facilities Manager' 
Roy R. Dingus, Building Engineer' 
Pablo D. Esparza, Maintenance Technician' 
Rose Filley, Research Technician 
David J. George, Electronics Technician 
Christos G. Hadidiacos, Electronics Engineer 
ShaunJ. Hardy, Librarian' 
Marjorie E. Imlay, Assistant to the Director 
William E. Key, Building Engineer' 
Adriana Kuehnel, Library Volunteer 
Paul Meeder, Administrative Assistant 
Lawrence B. Patrick, Maintenance Technician' 
Glenn Piercey, Research Technician 2 ' 
Pedro J. Roa, Maintenance Technician 10 
Roy E. Scalco, Engineering Apprentice 10 
Susan A. Schmidt, Coordinating Secretary 
John M. Straub, Business Manager 
Merri Wolf, Library Technical Assistant' 

Visiting Investigators 

John V. Badding, Pennsylvania State University 
Brigitte Behrends, Deutsche Akademische 

Austauschdienst, Bonn 
David R. Bell, Cape Town, South Africa 
Ben Burton, National Institute of Standards and 

Technology 



Altaf H. Carim, Pennsylvania State University 
Pamela Conrad, Jet Propulsion Laboratory, NASA 
I. Ming Chou, U.S. Geological Survey 
Jean Dubessy, Centre de Recherches sur La Geologie 

des Matieres Premieres Minerales et Energetiques, 

Vandoeuvre-Les-Nancy, France 
Thomas S. Duffy, Princeton University 
Joseph Feldman, Naval Research Laboratory 
Yuri Freiman, Verkin Institute of Low-Temperature 

Physics and Engineering, Ukrainian Academy of 

Sciences, Kharkov, Ukraine 
Reto Giere, Purdue University 
Donald G. Isaak, University of California at Los 

Angeles 
Deborah Kelley, University of Washington 
Boris Kiefer, University of Michigan 
Amy Y. Liu, Georgetown University 
Haozhe Liu, Institute of Physics, Chinese Academy of 

Sciences, Beijing 
Ryan P. McCormack, National Institute of Standards 

and Technology 
Harold Morowitz, George Mason University 
Yoshihide (Yoshi) Ogasawara, Waseda University, 

japan 
Michel Pichavant, CNRS-Orieans, France 
Nicolai P. Pokhilenko, Institute of Mineralogy and 

Petrology, Novosibirsk, Russia 
Robert K Popp, Texas A&M University 
Dean C. Presnall, University of Texas 
Pascal Richet, Institut de Physique du Globe, Paris, 

France 
Anil K. Singh, National Aerospace Laboratories, 

Bangalore, India 
Nicolai V. Sobolev, Institute of Mineralogy and 

Petrology, Academy of Sciences, Novosibirsk, Russia 
Gerd Steinle-Neumann, University of Michigan 
Lars Stixrude, University of Michigan 
Mikhail Strzhemechny, Verkin Institute of Low- 
Temperature Physics and Engineering, Ukrainian 

Academy of Sciences, Kharkov, Ukraine 
Jack Tossell, University of Maryland 
Noreen C Tuross, Smithsonian Institution 
Qingchen Wang, Chinese Academy of Sciences 
Wansheng Xiao, Institute of Geochemistry, Chinese 

Academy of Sciences, Guangzhou 
Hak Nan Yung, Chinese Academy of Sciences, 

Guangzhou 
Ru-Yuan Zhang, Stanford University 
Yi-Gang Zhang, Academia Sinica, China 
Guangtian Zou, Director of Center for Superhard 

Materials, Jilin University, Changchun, China 



'Retired June 30, 1999 

'Retired September 30. 1998 

'From September 28. 1998 

'Regular staff from July I, 1998 

s From April I, 1999 

'From January 4, 1 999 

'From August 10, 1998 

"To February 5, 1999 

"From August 1 , 1 998 

'"Joint appointment with DTM 

"From March I, 1999; joint appointment with DTM 

"To December 3, 1998 

"From January 15, 1999; joint appointment with DTM 

"From January II, 1999 

l5 From August 16, 1998 

"To September 1 , 1 998 

"From July 24, 1998 

'•From September 24. 1 998 

'To January 8, 1 999; joint appointment with DTM 

"from June 7. 1999 

"From June I. 1999 

"To July 30, 1998 

"From September 16, 1998 

"From June 1 , 1 999; joint appointment with DTM 

"To August 31, 1998 

"To March 31. 1999 

"From November 1 , 1 998 to March 31. 1 999 

"Deceased March 21. 1999 



Geophysical Laboratory Bibliography 



:arnegie institution 



YEAR BOOK p8~pp page 101 



2823 Aguilar, C, M. L Fogel, and H. W. Paerl, 
Dynamics of atmospheric combined inorganic 
nitrogen utilization in the coastal waters off 
North Carolina, Mar. Ecol. Prog. Ser. 180, 65-79, 
1999. (No reprints available.) 

Aoki, H., Y. Syono, and R. J. Hemley, 



Physics and mineralogy: the current confluence, 
in Physics Meets Mineralogy — Condensed Matter 
Physics in Geosciences, H. Aoki, Y. Syono, and R. 
J. Hemley, eds., Cambridge University Press, in 
press. 

Aoki, H„ Y. Syono, and R. J. Hemley, eds., 



Physics Meets Mineralogy — Condensed Matter 
Physics in Geosciences, Cambridge University 
Press, in press. 

Badro, J„ V. V. Struzhkin, J. Shu, R. J. 

Hemley, H. K. Mao, C. C. Kao, J. P. Rueff, and G. 
Shen, Magnetism in FeO at megabar pressures 
from x-ray emission spectroscopy, Phys. Rev. 
Lett., in press. 

2809 Bao, H., P. L Koch, and D. Rumble, III, 
Paleocene-Eocene climatic variation in western 
North America: evidence from the 5 I8 of 
pedogenic hematite, Geol. Soc. Am. Bull. Ill, 
1405-1415, 1999. 

Bearhop, S., M. A. Teece, S. Waldron, 

and R. W. Furness, The influence of lipid and 
uric acid upon 5 I3 C and 5 I5 N values of avian 
blood: amplications for trophic studies, The Auk, 
in press. 

2753 Boyd, F. R., The origin of cratonic peri- 
dotites: a major element approach, Int. Geol. 
Rev. 40, 755-764, 1998. (No reprints available.) 

2835 Boyd, F. R., The origin of cratonic peri- 
dotites: a major-element approach, in Planetary 
Petrology and Geochemistry, G. A. Snyder, C. R. 
Neal, and W. G. Ernst, eds., pp. 5- 1 4, 
Bellwether Publishing/Geological Society of 
America, Boulder, Colorado, 1 999. (No 
reprints available.) 

Boyd, F. R, D. G Pearson, and S. A. 



Mertzman, Spinel-facies peridotites from the 
Kaapvaal root, in Proceedings of the 7 th 
International Kimberlite Conference, in press. 

Brandes, I. A., N. Z. Boctor, R. M. Hazen, 



H. S. Yoder, Jr., and G. D. Cody, Prebiotic 
amino acid synthesis pathways via a-keto acids: 
an alternative to the Strecker synthesis, in 
Perspectives in Amino Acid and Protein 
Geochemistry, G A. Goodfriend et al., eds., 
Oxford University Press, New York, in press. 

2758 Brandes, J. A., A. H. Devol, T. Yoshinari, 
D. A. Jayakumar, and S. W. A. Naqvi, Isotopic 
composition of nitrate in the central Arabian 
Sea and eastern tropical North Pacific: a tracer 
for mixing and nitrogen cycles, Limnol. Oceanogr. 
43, 1680-1689, 1998. (No reprints available.) 

Canm, A. H., P. Dera, L W. Finger, B. 

Mysen, C T. Prewitt, and D. G. Schlom, Crystal 
structure and compressibility of Ba^Ru 3 O 10 , J. 
Solid State Chem., in press. 

Carlson, R W„ D. G Pearson, F. R Boyd, 

S. B. Shirey, G. Irvine, A. H. Menzies, and J. J. 
Gurney, Re-Os systematics of lithospheric peri- 
dotites: implications for lithosphere formation 
and preservation, in Proceedings of the 7th 
International Kimberlite Conference, in press. 



2785 Cody, G D„ and G Saghi-Szabo, 
Calculation of the l3 C NMR chemical shift of 
ether linkages of lignin derived geopolymers: 
constraints on the preservation of lignin primary 
structure with diagenesis, Geochim. Cosmochim. 
Acta 63, 193-205, 1999. 

2822 Cody, G. D., and P. Thiyagarajan, The 
macromolecular structure of coal: insight 
derived from small angle neutron scattering, in 
Materials Research Using Cold Neutrons at Pulsed 
Neutron Sources, P. Thiyagarajan et al., eds., pp. 
I 29- 1 40, World Scientific, Singapore, 1 999. 
(No reprints available.) 

2834 Cohen, R. E., Mineral physics, Geotimes 
44 (no. 7), 35-36, 1999. (No reprints available.) 

Cohen, R. E., Bonding and electronic 



structure of minerals, in Microscopic Properties 
and Processes in Minerals, K. Wright and C R. A. 
Catlow, eds., NATO ASI Proceedings, Kluwer 
Academic Publishers, Dordrecht, in press. 

Cohen, R. E., MgO — the simplest miner- 



al, in Physics Meets Mineralogy — Condensed 
Matter Physics in Geosciences, H. Aoki, Y. Syono, 
and R. J. Hemley, eds., Cambridge University 
Press, in press. 

Cohen, R. E., Theory of ferroelectrics: a 



vision for the next decade and beyond, J. Phys. 
Chem. Solids, in press. 

Cohen, R. E., O. Gulseren, and R. 



Hemley, Accuracy in equation of state formula- 
tions, Am. Mineral., in press. 

2775 Conrad, P. G, C. S. Zha, H. K. Mao, and 
R. J. Hemley, The high-pressure, single-crystal 
elasticity of pyrope, grossular, and andradite, 
Am. Mineral. 84, 374-383, 1999. 

2774 Downs, R T., H. Yang, R. M. Hazen, L 
W. Finger, and C T Prewitt, Compressibility 
mechanisms of alkali feldspars: new data from 
reedmergnerite, Am. Mineral. 84, 333-340, 
1999. 

Duffy, T S., G. Shen, D. L Heinz, Y. Ma, J. 



Shu, H. K. Mao, R. J. Hemley, and A. K. Singh, 
Lattice strains in gold and rhenium under non- 
hydrostatic compression to 37 GPa, Phys. Rev. 
B, in press. 

Duffy, T S„ G Shen, J. Shu, H. K. Mao, R 



J. Hemley, and A. K. Singh, Elasticity, shear 
strength, and equation of state of molybdenum 
and gold under non-hydrostatic compression to 
24 GPa, J. Appl. Phys., in press. 

Eggert, J. H., E. Karmon, R J. Hemley, H. 



K. Mao, and A. F. Goncharov, Pressure- 
enhanced ortho-para conversion in solid hydro- 
gen up to 58 GPa, Proc. Natl. Acad. Sa. USA, in 
press. 

282 1 Fantle, M. S„ A. I. Dittel, S. M. Schwalm, 
C E. Epifanio, and M. L Fogel, A food web 
analysis of the juvenile blue crab, Callinectes 
sapidus, using stable isotopes in whole animals 
and individual amino acids, Oecologia 1 20, 4 1 6- 
426, 1999. 

28 1 I Farquhar, J., E. Hauri, and J. Wang, New 
insights into carbon fluid chemistry and graphite 
precipitation: SIMS analysis of granulite facies 
graphite from Ponmudi, South India, Earth 
Planet. Sa. Lett. 171, 607-62 1 , 1 999. 



2756 Farquhar, J., and D. Rumble, III, 
Comparison of oxygen isotope data obtained 
by laser fluorination of olivine with KrF excimer 
laser and C0 2 laser, Geochim. Cosmochim. Acta 
62, 3141-3149, 1998. 

2764 Fei, Y., Solid solutions and element parti- 
tioning at high pressures and temperatures, Rev. 
Mineral. 37, 343-367, 1998. (No repnnts avail- 
able.) 

2773 Fei, Y„ Effects of temperature and com- 
position on the bulk modulus of (Mg.Fe)O, Am. 
Mineral. 84, 272-276, 1 999. 

28 I 3 Fei, Y., and C. M. Bertka, Phase transi- 
tions in the Earth's mantle and mantle mineral- 
ogy, in Mantle Petrology: Field Observations and 
High Pressure Experimentation, Y. Fei, G M. 
Bertka, and B. O. Mysen, eds., pp. 1 89-207, 
Special Publication No. 6, Geochemical Society, 
Houston, 1999. 

28 I 2 Fei, Y., C M. Bertka, and B. O. Mysen, 
eds., Mantle Petrology: Field Observations and 
High Pressure Experimentation: A Tribute to 
Francis R. (joe) Boyd, Special Publication No. 6, 
Geochemical Society, Houston, 322 pp., 1999. 
(Available for purchase from the publisher.) 

2769 Fei, Y., D. J. Frost, H. K. Mao, C T 
Prewitt, and D. Hausermann, In situ structure 
determination of the high-pressure phase of 
Fe 3 4 , Am. Mineral. 84, 203-206, 1 999. 

2804 Feldman, J. L, J. H. Eggert, J. De Kinder, 
H. K. Mao, and R. J. Hemley, Influence of order- 
disorder on the vibron excitations of H 2 and D 2 
in ortho-para mixed crystals,/ Low Temp. Phys. 
115, 181-216, 1999. 

2798 Fiebig, J., U. Wiechert, D. Rumble, III, and 
J. Hoefs, High-precision in situ oxygen isotope 
analysis of quartz using an ArF laser, Geochim. 
Cosmochim. Acta 63, 687-702, 1 999. 

Riley, T, P. G Hatcher, W. C Shortle, 



and R. T. Praseuth, The application of re- 
labeled tetramethylammonium hydroxide ( l3 C- 
TMAH) thermolysis to the study of the fungal 
degradation of wood, Org. Geochem., in press. 

2827 Filley, T. R, R. D. Mmard, and P. G 
Hatcher, Tetramethylammonium hydroxide 
(TMAH) themochemolysis: proposed mecha- 
nisms based upon the application of ' 3 C-labeled 
TMAH to a synthetic model lignin dimer, Org. 
Geochem. 30,607-621, 1999. 

2824 Fogel, M. L, C Aguilar, R Cuhel, D. J. 
Hollander, J. D. Willey, and H. W. Paerl, 
Biological and isotopic changes in coastal waters 
induced by Hurricane Gordon, Limnol. 
Oceanogr. 44, 1359-1369, 1999. 

2825 Fogel, M. L, and N. Tuross, 
Transformation of plant biochemicals to geo- 
logical macromolecules dunng early diagenesis, 
Oecologia 120, 336-346, 1999. 

Frantz, J. D., Salts of aliphatic carboxylic 

acids: spectra and ion painng in hydrothermal 
solutions containing sodium and calcium 
acetates, Chem. Geol., in press. 

2783 Freiman, Yu. A., R. J. Hemley, A. Jezowski, 
and S. M. Tretyak, Broken symmetry phase 
transition in solid p-H,, o-D, and HD: crystal 
field effects, Physica B 265, 12-15, 1 999. 



CARNEGIE INSTITUTION 



page 102 I YEAR BOOK p8~pp 



updated thn u : N ember 2. 1999. The list is regularly updated on the Geophysical Laboratoiy Web site 
.vww.gl.ciw.edu/libraiy/). Reprints of the numbered publications listed below are available, except where noted, at n 
in, Geophysical Laboratory, 5251 Broad Branch Road, N.W., Washington, D.C. 20015-1305, U.S.A. 
(E-mail: Iibrat7@dtm.ciw.edu). Please give reprint number(s) when ordering. 



28 1 4 Frost, D. J., and Y. Fei, Static compression 
of the hydrous magnesium silicate phase D to 
30 GPa at room temperature, Phys. Chem. 
Minerals 26, 415-418, 1 999. 

2806 Ghiorso, M. S., H. Yang, and R. M. Hazen, 
Thermodynamics of cation ordering in kar- 
rooite (MgTi 2 O s ), Am. Mineral. 84, I 370- 1 374, 
1999. 

Gibbs, G. V., F. C. Hill, M. B. Boisen.Jr., 

and R. T. Downs, Molecules as a basis for mod- 
eling the force field of silica, in Structure and 
Imperfections in Amorphous and Crystalline SiO>, 
R. A. B. Devine, J.-P. Duraud, and E. Dooryhee, 
eds„ John Wiley & Sons, in press. 

2765 Gillet, P., R. J. Hemley, and P. F. McMillan, 
Vibrational properties at high pressures and 
temperatures, Rev. Mineral. 37, 525-590, 1998. 

28 10 Goncharov, A. R, V. V. Struzhkin, H. K. 
Mao, and R. J. Hemley, Raman spectroscopy of 
dense H 2 and the transition to symmetric 
hydrogen bonds, Phys. Rev. Lett. 83, 1 998-200 1 , 
1999. 

283 1 Goodfriend, G. A., Terrestrial stable iso- 
tope records of late Quaternary paleoclimates 
in the eastern Mediterranean region, Quat. Sci. 
Rev. 1 8, 50 1 -5 I 3, 1 999. (No reprints available.) 

Goodfriend, G. A., M. J. Collins, M. L 



Fogel, S. A. Macko, and J. F. Wehmiller, eds., 
Perspectives in Amino Acid and Protein 
Geochemistry, Oxford University Press, New 
York, in press. 

2779 Goodfriend, G, A., and D. J. Stanley, 
Rapid strand-plain accretion in the northeastern 
Nile Delta in the 9th century A.D. and the 
demise of the port of Pelusium, Geology 27, 
147-150, 1999. 

2830 Hammouda, T., and M. Pichavant, 
Kinetics of melting of fluorphlogopite-quartz 
pairs at I atmosphere, Eur. J. Mineral. I 1 , 637- 
653, 1999. (No reprints available.) 

2749 Hazen, R. M., Finie, la science? Tu paries, 
Charles!, Le Temps strategique 84, 80-95, 1998 
November/December. (No reprints available.) 

2777 Hazen, R. M., A new perspective on the 
origin of life, in The NOVA Reader. Science at the 
Turn of the Millennium, S. Hackman, ed„ pp. 48- 
54, TV Books, New York, 1 999. (No reprints 
available.) 

280 1 Hazen, R. M., The Great Principles of 
Science [60 lectures on videocassette and audio- 
cassette with course guide], The Teaching 
Company, Springfield, Virginia, 1999. (Available 
for purchase from the publisher.) 

2807 Hazen, R. M., The Diamond Makers, 
Cambridge University Press, Cambridge and 
New York, 2 1 4 pp., 1 999. (Available at book- 
stores or from the publisher.) 

28 I 8 Hazen, R. M., Plate tectonics, in 
Encyclopedia Americana, vol. 22, pp. 223-226, 
Grolier, Danbury, Connecticut, 1 998. (No 
reprints available.) 

Hazen, R. M., The endless frontier in sci- 
entific research, in Accelerating Creativity, G L. 
Harper, ed., Templeton Foundation, Radnor, 
Pennsylvania, in press. 



Hazen, R. M., M. H. Hazen, and S. Pober, 

American Geological Literature: 1669-1850, 
Pober Publishing, Staten Island, New York, in 
press. 

Hazen, R. M., M. B. Weinberger, H. Yang, 



and C. T. Prewitt, Comparative high-pressure 
crystal chemistry of wadsleyite, 
/3-(Mg,- x Fe x )2SiO„ with x=0 and 0.25, Am. 
Mineral., in press. 

Hazen, R. M., and H. Yang, Effects of 



cation substitution and order-disorder on P-V-T 
equations of state of cubic spinels, Am. Mineral., 
in press. 

2788 Hazen, R. M., H. Yang, L W. Finger, and 
B. A. Fursenko, Crystal chemistry of high-pres- 
sure BaSi 4 0, in the trigonal (P3) barium 
tetragermanate structure, Am. Mineral. 84, 987- 



Hazen, R. M„ H. Yang, and C T. Prewitt, 



High-pressure crystal chemistry of Fe 3+ -wads- 
leyite, j8-Fe2.33Sio.67O4, Am. Mineral., in press. 

2759 Hemley, R. J., ed., Ultrahigh-Pressure 
Mineralogy: Physics and Chemistry of the Earth's 
Deep Interior, Reviews in Mineralogy, Vol. 37, 
Mineralogical Society of America, Washington, 
D.C, 671 pp., 1 998. (Available for purchase 
from the publisher.) 

2803 Hemley, R. J., Mineralogy at a crossroads, 
Science 285, 1026-1027, 1999. 

Hemley, R. J., J. Badro, and D. M. Teter, 



High-pressure crystalline and amorphous silica, 
in Physics Meets Mineralogy — Condensed Matter 
Physics in Geosciences, H. Aoki, Y. Syono, and R. 
J. Hemley, eds., Cambridge University Press, in 
press. 

2752 Hemley, R. J., and H. K. Mao, New phe- 
nomena in low-Z materials at megabar pres- 
sures,/ Phys.: Cond. Matter 10, I I I 57- 1 I I 67, 



2766 Hemley, R. J., H. K. Mao, and R. E. 
Cohen, High-pressure electronic and magnetic 
properties, Rev. Mineral. 37, 591-638, 1998. 

Hemley, R. J., H. K. Mao, and S. A. 



Gramsch, Transformation in deep mantle and 
core minerals, Mineral. Mag., in press. 

2800 Hemley, R. J., H. K. Mao, M. S. 
Somayazulu, Y. Ma, P. F. McMillan, and G H. 
Wolf, Investigations of new ceramic materials at 
high pressures and temperatures, in Advanced 
Materials '99, New Semiconducting Materials: 
Diamond and Related Materials (Proceedings of 
the 6th NIRIM International Symposium on 
Advanced Materials), Y. Bando et al., eds., pp. 
15-16, National Institute for Research in 
Inorganic Materials, Tsukuba, Japan, 1999. 

2748 Hemley, R. J., M. S. Somayazulu, A. F. 
Goncharov, and H. K. Mao, High-pressure 
Raman spectroscopy of Ar-H 2 and CH4-H 2 van 
der Waals compounds, Asian J. Phys. 7, 3 1 9- 
322, 1998. 

2768 Hirose, K., Y. Fei, Y. Ma, and H. K. Mao, 
The fate of subducted basaltic crust in the 
Earth's lower mantle, Nature 397, 53-56, 1999. 

2776 Hofmeister, A. M., H. Cynn, P. C. 
Burnley, and C Meade, Vibrational spectra of 
dense, hydrous magnesium silicates at high 
pressure: importance of the hydrogen bond 
angle, Am. Mineral. 84, 454-464, 1 999. 



llchik, R. P., and D. Rumble, III, Sulfur, car- 
bon, and oxygen systematics during diagenesis 
and fluid infiltration in the Creede Caldera, 
Colorado, in Preliminary Scientific Results of the 
Creede Caldera Continental Scientific Drilling 
Program, P. M. Bethke, ed., Geological Society 
of America, in press. 

2772 Jephcoat, A. P., J. A. Hriljac, C A. 
McCammon, H. St. C O'Neill, D. C Rubie, and 
L. W. Finger, High-resolution synchrotron X-ray 
powder diffraction and Rietveld structure 
refinement of two (Mg .95,Feoos)Si0 3 perovskite 
samples synthesized under different oxygen 
fugacity conditions, Am. Mineral. 84, 2 1 4-220, 
1999. 

2786 Johnson, B. J., G. H. Miller, M. L Fogel, J, 
W. Magee, M. K. Gagan, and A. R. Chivas, 
65,000 years of vegetation change in central 
Australia and the Australian summer monsoon, 
Science 284, I 150-1 152, 1999. 

2817 Kennedy, D., B. Alberts, D. Ezell, T. 
Goldsmith, R. Hazen, N. Lederman, J. 
Mclnerney, J. Moore, E. Scott, M. Singer, M. 
Smith, M. Suiter, and R. Wood, Teaching about 
Evolution and the Nature of Science, National 
Academy of Sciences/National Academy Press, 
Washington, D.C, 140 pp., 1998. (Available for 
purchase from the publisher.) 

Konzett, J., and Y. Fei, Transport and 

storage of potassium in the Earth's upper man- 
tle and transition zone: an experimental study 
to 23 GPa in simplified and natural bulk com- 
positions,/ Petrol., in press. 

28 1 5 Linton, J. A., Y. Fei, and A. Navrotsky, 
The MgTi0 3 -FeTi0 3 join at high pressure and 
temperature, Am. Mineral. 84, I 595- 1 603, 1 999. 

276 1 Liou, J. G, R. Y. Zhang, W. G. Ernst, D. 
Rumble, III, and S. Maruyama, High-pressure 
minerals from deeply subducted metamorphic 
rocks, Rev. Mineral. 37, 33-96, 1998. (No 
reprints available.) 

28 1 6 Lu, R., A. F. Goncharov, H. K Mao, and 
R. J. Hemley, Synchrotron infrared microspec- 
troscopy: applications to hydrous minerals, in 
Synchrotron X-ray Methods in Clay Science, D. G. 
Schulze, J. W. Stuck, and P. M. Bertsch, eds., pp. 
1 65- 1 82, CMS Workshop Lectures, Vol. 9, Clay 
Minerals Society, Boulder, Colorado, 1999. 

2760 Mao, H. K, and R. j. Hemley, New win- 
dows on the Earth's deep interior, Rev. Mineral. 
37, 1-32, 1998. 

2757 Mao, H. K, J. Shu, G. Shen, R. J. Hemley, 
B. Li, and A. K Singh, Elasticity and rheology of 
iron above 220 GPa and the nature of the 
Earth's inner core, Nature 396, 74 1 -743, 1 998. 

2778 Merkel, S„ R. J. Hemley, and H. K. Mao, 
Finite-element modeling of diamond deforma- 
tion at multimegabar pressures, Appl. Phys. Lett. 
74,656-658, 1999. 

2770 Miller, G. H, J. W. Magee, B. J. Johnson, 
M. L Fogel, N. A. Spooner, M. T. McCulloch, 
and L K Ayliffe, Pleistocene extinction of 
Genyornis newtoni: human impact on Australian 
megafauna, Science 283, 205-208, 1 999. 

2747 Minarik, W. G, Complications to carbon- 
ate melt mobility due to the presence of an 
immiscible silicate melt,/ Petrol. 39, 1965-1973, 
1998. 



Geophysical Laboratory Bibliography 



■ 



ARNEGIE INSTITUTION 



'EAR BOOK 98—99 I page 103 



2832 Murillo de Nava, J., D. S. Gorsline, G. A. 
Goodfriend, V. K. Vlasov, and R. Cruz-Orozco, 
Evidence of Holocene climatic changes from 
aeolian deposits in Baja California Sur, Mexico, 
Quat. Int. 56; 141-154, 1999. (No reprints avail- 
able.) 

278 1 Mysen, B. O., Structure and properties of 
magmatic liquids: from haplobasalt to naploan- 
desite, Geochim. Cosmochim. Acta 63, 95- 1 1 2, 
1999. 

Mysen, B. O., Water in H 2 Q-saturated 



magma-fluid systems: solubility behavior in K 2 0- 
Al 2 3 -Si0 2 -H 2 to 2.0 GPa and I 300°C, 
Geochim. Cosmochim. Acta, in press. 

2805 Mysen, B. O., F. Holtz, M. Pichavant, J.-M. 
Beny, and J.-M. Montel, The effect of tempera- 
ture and bulk composition on the solution 
mechanism of phosphorus in peraluminous 
haplogranitic magma, Am. Mineral. 84, I 336- 
1345, 1999. 

2762 Mysen, B. O., P. Ulmer, J. Konzett, and M. 
W. Schmidt, The upper mantle near conver- 
gent plate boundaries, Rev. Mineral. 37, 97- 1 38, 
1998. (No reprints available.) 

Norinaga, K., J. Hayashi, T, Chiba, G. D. 



Cody, and M. lino, Microheterogeneity of sol- 
vent-swollen coal probed by proton spin diffu- 
sion, Energy & Fuels, in press. 

2826 Paerl, H. W., J. D. Willey, M. Go, B. L 
Peierls, J. L Pinckney, and M. L Fogel, Rainfall 
stimulation of primary production in western 
Atlantic Ocean waters: roles of different nitro- 
gen sources and co-limiting nutrients, Mar. Ecol. 
Prog. Ser. 176, 205-214, 1999. (No reprints 
available.)" 

2763 Prewitt, C T, and R T Downs, High- 
pressure crystal chemistry, Rev. Mineral. 37, 
283-3 1 7, 1 998. (No reprints available.) 

2808 Richet, P., and B. O. Mysen, High-tem- 
perature dynamics in cristobalite (Si0 2 ) and 
carnegieite (NaAISi0 4 ): a Raman spectroscopy 
study, Geophys. Res. Lett. 26, 2283-2286, 1999. 

2782 Rueff, J.-P., C.-C Kao, V. V. Struzhkin, j. 
Badro, J. Shu, R. J. Hemley, and H. K. Mao, 
Pressure-induced high-spin to low-spin transi- 
tion in FeS evidenced by x-ray emission spec- 
troscopy, Phys. Rev. Lett. 82, 3284-3287, 1999. 

2750 Rumble, D., Stable isotope geochemistry 
of ultrahigh-pressure rocks, in When Continents 
Collide: Geodynamics and Geochemistry of 
Ultrahigh-Pressure Rocks, B. R. Hacker, and J. G. 
Liou, eds., pp. 241-259, Kluwer Academic 
Publishers, Dordrecht, 1998. (No reprints avail- 
able^) 

2820 Rumble, D., and Z. D. Sharp, Laser 
microanalysis of silicates for l8 0/ l7 0/ l6 and of 
carbonates for l8 0/ 16 and l3 C/ l2 C, in 
Applications of Microanalytical Techniques to 
Understanding Mineralizing Processes, M. A. 
McKibben, W. C Shanks, III, and W. I. Ridley, 
eds., pp. 99-1 19, Reviews in Economic Geology, 
Vol. 7, Society of Economic Geologists, 
Littleton, Colorado, 1998. 

2819 Rumble, D., and T.-F. Yui, The 
Qinglongshan oxygen and hydrogen isotope 
anomaly near Donghai in Jiangsu Province, 
China, Geochim. Cosmochim. Acta 62, 3307- 
3321, 1998. 



Rushmer, T, W. G. Minarik, and G. J. 



Taylor, Physical processes of core formation, in 
Origin of the Earth and Moon, K. Righter and R. 
M. Canup, eds., University of Arizona 
Press/Lunar and Planetary Institute, in press. 

2797 Saghi-Szabo, G., R E. Cohen, and H. 
Krakauer, First-principles study of piezoelectrici- 
ty in tetragonal PbTi0 3 and PbZr, /2 Ti| /2 3 , Phys. 
Rev. B 59, 1 277 1 - 1 2776, 1999. 

2829 Saxena, S. K„ L S. Dubrovinsky, P. Lazor, 
and J. Hu, In situ X-ray study of perovskite 
(MgSi0 3 ): phase transition and dissociation 
under mantle conditions, Eur. J. Mineral. 10, 
1275-1281, 1998. 

2828 Skelton, E. F., P. L Hagans, S. B. Qadn, D. 

D. Dominguez, A. G Ehrlich, and J. Z. Hu, In 
situ monitoring of crystallographic changes in Pd 
induced by diffusion of D, Phys. Rev. B 58, 
14775-14779, 1998. (No reprints available.) 

2799 Steinle-Neumann, G., L Stixrude, and R. 

E. Cohen, First-principles elastic constants for 
the hep transition metals Fe, Co, and Re at high 
pressure, Phys. Rev. B 60, 79 I -799, 1 999. 

2767 Stixrude, L, R. E. Cohen, and R. J. 
Hemley, Theory of minerals at high pressure, 
Rev. Mineral. 37,639-671, 1998. 

Teece, M. A., M. L Fogel, M. E. Dollhopf, 



and K. H. Nealson, Isotopic fractionation associ- 
ated with biosynthesis of fatty acids by a marine 
bacterium under oxic and anoxic conditions, 
Org. Geochem., in press. 

Teece, M. A., N. Tuross, I. Kress, P. 



Peterson, G. Russell, and M. L Fogel, 
Preservation of proteins in museum herbarium 
samples, in Perspectives in Amino Acid and 
Protein Geochemistry, G. A. Goodfriend et al., 
eds., Oxford University Press, New York, in 
press. 

2833 Timofeev, Yu. A, H. K. Mao, V. V. 
Struzhkin, and R J. Hemley, Inductive method 
for investigation of ferromagnetic properties of 
materials under pressure, Rev. Sci. Instrum. 70, 
4059-4061, 1999. 

Velinsky, D. J., and M. L Fogel, Cycling of 



dissolved and particulate nitrogen and carbon in 
the Framvaren Fjord, Norway: stable isotopic 
variations, Mar. Chem., in press. 

Virgo, D., and R. K. Popp, H-deficiency in 



mantle-derived phlogopites, Am. Mineral, in 
press. 

2802 Yang, C S., C S. Ro, W. C Chou, C M. 
Lin, D. S. Chuu, J. Hu, E. Huang, and J. Xu, 
Energy-dispersive x-ray diffraction and Raman 
scattering of Zn lx Mn.Se bulk crystals at high 
pressure,/ Appl. Phys. 85, 8092-8096, 1999. 
(No reprints available.) 

277 I Yang, H, L W. Finger, P. G. Conrad, C. 
T Prewitt, and R. M. Hazen, A new pyroxene 
structure observed at high pressure: single-crys- 
tal X-ray and Raman study of the Pbcn-Pl^n 
phase transition in protopyroxene, Am. Mineral. 
84,245-256, 1999. 

275 I Yang, H., and R. M. Hazen, Comparative 
high-pressure crystal chemistry of karooite, 
MgTi jO s , with different ordering states, Am. 
Mineral. 84, 130-137, 1999. 



2780 Yang, H, J. Konzett, C T. Prewitt, and Y. 
Fei, Single-crystal structure refinement of syn- 
thetic M4 K-substituted potassic richterite, 
K(KCa)Mg 5 Si 8 22 (OH) 2 , Am. Mineral. 84, 
681-684, 1999. 

2787 Yang, H„ and C T. Prewitt, On the crys- 
tal structure of pseudowollastonite (CaSi0 3 ), 
Am. Mineral. 84, 929-932, 1999. 

Yang, H., and C T, Prewitt, Crystal struc- 



ture and compressibility of a two-layer polytype 
of pseudowollastonite (CaSi0 3 ), Am. Mineral., in 
press. 

2789 Yoder, H. S., Jr., "Norman Levi Bowen," 
in American National Biography, j. A. Garraty and 
M. C Carnes, eds., vol. 3, pp. 282-285, Oxford 
University Press, New York, 1 999. (No reprints 
available.) 

2790 Yoder, H. S., Jr., "Henry Stephens 
Washington," in American National Biography, J. 
A. Garraty and M. C Carnes, eds., vol. 22, pp. 
769-77 1 , Oxford University Press, New York, 
1999. (No reprints available.) 

279 I Yoder, H. S„ Jr., "Charles Whitman 
Cross," in American National Biography, J. A. 
Garraty and M. C Carnes, eds., vol. 5, pp. 787- 
789, Oxford University Press, New York, 1 999. 
(No reprints available.) 

2792 Yoder, H. S., Jr., "Samuel Franklin 
Emmons," in American National Biography, J. A. 
Garraty and M. C Carnes, eds., vol. 7, pp. 5 1 0- 
511, Oxford University Press, New York, 1 999. 
(No reprints available.) 

2793 Yoder, H. S., Jr., "Joseph Paxson Iddings," 
in American National Biography, J. A. Garraty and 
M. C. Carnes, eds., vol. I I , pp. 628-629, Oxford 
University Press, New York, 1 999. (No reprints 
available.) 

2794 Yoder, H. S., Jr., "Waldemar Lindgren," in 
American National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. I 3, pp. 692-693, Oxford 
University Press, New York, 1 999. (No reprints 

available.) 

2795 Yoder, H. S., Jr., "William Thomas 
Pecora," in Amencan National Biography, J. A. 
Garraty and M. C Carnes, eds., vol. 1 7, pp. 
236-237, Oxford University Press, New York, 
1999. (No reprints available.) 

2796 Yoder, H. S„ Jr., "Louis Valentine 
Pirsson," in American National Biography, J. A. 
Garraty and M. C Carnes, eds., vol. 1 7, pp. 
560-56 1 , Oxford University Press, New York, 
1999. (No reprints available.) 

2754 Young, E. D„ M. L Fogel, D. Rumble, III, 
and T. C Hoenng, Isotope-ratio-monitonng of 
O; for microanalysis of l8 0/ lb O and r O/ ,( in 
geological materials, Geochim. Cosmochim. Acta 
62, 3087-3094, 1998. 

2755 Young, E. D„ H. Nagahara, B. O. Mysen, 
and D. M. Audet, Non-Rayleigh oxygen isotope 
fractionation by mineral evaporation: theory 
and experiments in the system SiO-, Geochim. 
Cosmochim. Acta 62, 3 1 09-3 I I 6, 1 998. 

2784 Zhang, R. Y„ J. F. Shu, H. K Mao, and J. 
G. Liou, Magnetite lamellae in olivine and clino- 
humite from Dabie UHP ultramafic rocks, cen- 
tral China, Am. Mineral. 84, 564-569, 1 999. 







.■:.>..,. 
■ ■■■■■. ■ ■■■ 



CARNEGIE INSTITUTION 



page 104 I YEAR BOOK p8~pp 



.. 






1 mm 




Department of Terrestrial Magnetism 



, 



CARNEGIE INSTITUTION 



YEAR BOOKpS-yp page I0f 



THE DIRECTOR'S INTRODUCTION: 

The Ever- Whirling Wheel of Change 






"...i find it to be the general method of nature, which is always 
going forward, and continually making a progress of changing all 
things from the state in which it finds them in at the present..." 

Robert Hooke (1699) 1 



n he study of nature, as the English physicist and 
geologist Robert Hooke observed, is the study of 
change. Galaxies form and interact, stimulating 
the formation of stars. As stars consume their 
nuclear fuel, their often violent death throes can 
trigger the collapse of nearby clouds of gas and 
dust, generating new stars. Accompanying the for- 
mation of many stars was the formation of orbiting 
planetesimals and planets. The former are pre- 
served in our solar system as asteroids and comets, 
and the latter are now known from recent discov- 
eries of planets around other stars to include 
objects several times more massive than Jupiter. 
Our Earth and other Earth-like planets formed 
from the accretion of solid planetesimals and 
retained sufficient internal energy, augmented by 
the energy of radioactive decay, to melt rock and 
deform the surface for eons thereafter. Volcanic 
eruptions and earthquakes, the modern manifesta- 
tions of that energy, provide important clues to the 
processes by which the Earth transports heat and 
magma from its deep interior to the ever moving 
tectonic plates and the volcanic centers concentrated 
near plate boundaries. Life on Earth has been both 
a beneficiary and an agent of changes in the plan- 
et's atmosphere, hydrosphere, and upper crust. 



These subjects form the core of the research enter- 
prise at the Department of Terrestrial Magnetism. 
The 13 essays that follow, each by a member of 
the Research Staff, highlight aspects of recent 
work. They convey a flavor of staff interests and 
how those interests, too, change as new tools or 
discoveries reveal new questions and open fresh 
avenues for inquiry. 




Shown from left are DTM summer research interns Kirsten 
Brandt (Earlham College), Patrick Kelly (Sidwell Friends High 
School), Lan-Anh Ngoc Nguyen (University of North 
Carolina), Kisha Steele (Howard University), Kaisa Mueller 
(University of Missouri, Columbia), Caleb Fassett (Williams 
College), and Jacob Bauer (Spring Hill College). 



I . Hooke, Robert, A Discourse on the Causes of Earthquakes. July 30, 1 699, published 
in The Posthumous Works of Robert Hooke, London, 1705. 

Left: Close-up view of a sulfide inclusion in a diamond from the Orapa kimberlite in Botswana, obtained with an optical microscope and 
incident light. The sulfide inclusion lies within the white dashed lines at the center of a "rosette" of fractures that radiate from the inclusion. 
These fractures formed by decompression when the diamond was transported rapidly to the Earth's surface during the volcanic eruption of 
the kimberlite. The edge of the diamond is visible in the upper right. (Photo courtesy of Steven B. Shirey.) 




Change, of course, characterizes those who study 
as well as the subjects of our investigations. Two 
important changes in our Research Staff occurred 
during 1999. Francois Schweizer, a member of the 
staff at DTM since 1981, left the department at 
the end of August to join the staff of the Carnegie 
Observatories. That same month saw the arrival of 
our newest Staff Member, Paul Butler, an 
astronomer whose specialty is the detection and 
characterization of extrasolar planets. Schweizer's 
final DTM essay, and Butler's first such piece, are 
both included here and illustrate how astronomy at 
DTM is undergoing its own metamorphosis. 

The pace and feel of daily activities on this campus 
also evolved over the past year. There were several 
new additions to the pool of talented postdoctoral 
scientists in the department (see Year Book 97/98, 



pp. 59-69) as others departed for academic or 
research positions at other institutions. The first 
full year of a new director of our sister department, 
the Geophysical Laboratory, saw the scientific and 
infrastructural boundaries between the two depart- 
ments continue to blur. One measure of these 
changes is that 10 members of the DTM Research 
Staff are now formal coinvestigators on externally 
funded projects involving collaboration between 
the two departments. This past summer, the 
research intern programs at the two departments 
were formally merged, and 15 bright young men 
and women from colleges and secondary schools 
around the country were immersed for 10 weeks in 
the research programs of the institution. 

Even the boundaries between heretofore distinct sci- 
entific disciplines are warping and falling. Nowhere 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 10/ 



is this locally more evident than through Carnegie's 
participation as a lead institution in the NASA insti- 
tute for the newly amalgamated field of astrobiology, 
founded with no less audacious a goal than the 
"understanding of the origins, evolution, distribu- 
tion, and future of life on Earth and in the universe." 
Working under the auspices of this institute, now 
in its second year, are six Staff Members from 
DTM and an equal number from the Geophysical 
Laboratory. Few of these individuals imagined 
themselves as contributing to the advance of the 
biological sciences as little as two or three years ago. 

Robert Hooke's insightful generalization of three 
centuries ago may be more encompassing than 
even he imagined. 

— Sean C. Solomon 

Virgo Cluster Galaxies with Disturbed 
Kinematics, and the Cluster Approach 
to Equilibrium 

Vera C. Rubin 

We live in an era in which galaxies are forming 
into clusters. In a galaxy cluster, the high central 
galaxy density overcomes the expansion of the uni- 
verse, and the galaxies are not separating, one from 
the other, but are gravitationally bound to the 
group. Some clusters, formed early, appear to be in 
dynamical equilibrium, with a deep central poten- 
tial, massive elliptical galaxies in the core, and a 
fairly smooth spherical distribution of constituent 
galaxies. Younger clusters, like our nearby Virgo 
cluster, still contain irregular clumps of galaxies, 
which are expected to smooth out during their 
consequent evolution. 

It has long been known that the Virgo cluster 
galaxies exhibit a curious distribution of central 
velocities when the galaxies are separated into 
ellipticals and spirals. The ellipticals, a population 
probably well on their way toward dynamical equi- 
librium, exhibit a Gaussian distribution of 
observed velocities with many velocities near 1,100 
km/second. In contrast, the spirals have velocities 
that range equally from about -400 km/second 
(i.e., approach with respect to the cluster mean 
velocity) to about +2,600 km/second (i.e., reces- 



sion). Hence the cluster, well defined by the ellip- 
ticals, is poorly defined by the spiral velocities. 

Over the past decade, I have observed internal 
rotational velocities for the ionized gas component 
in 100 spiral galaxies in the Virgo cluster. Together 
with high school student Andrew Waterman and 
Yale University astronomer Jeff Kenney, I have 
analyzed these data. We divide the spirals into two 
groups, roughly equal in number: those with normal 
rotation properties, and those with significantly 
disturbed rotation. Independent of galaxy rotation 
properties, parameters such as galaxy brightness 
and Hubble type are the same for both groups. 

However, the central velocities are strikingly dif- 
ferent. Spirals with normal rotation curves have 
central velocities distributed evenly from -400 to 
+2,600 km/second, like the previously known spi- 
rals. In contrast, spirals with disturbed rotation 
have a distribution of central velocities that matches, 
almost exactly, the velocity distribution of the 
ellipticals (Fig. 1). Moreover, the distribution on 
the sky of the galaxies with disturbed rotation 
shows that these galaxies are preferentially on 
elongated radial orbits, which carry them close to 
the central core of the cluster. Here, tidal interac- 
tions are strong and more common. 

We believe that the disturbed rotation properties 
arise from galaxy-galaxy or galaxy-cluster field 
interactions. Galaxies with disturbed rotation have 




-1000 1000 2000 

SYSTEMIC VELOCITY (km/sec) 



3000 



Fig. I . The distribution of 43 spirals with disturbed rotation 
curves, as a function of systemic velocity, are superposed 
here on a histogram that shows the distribution of 1 64 ellipti- 
cals in Virgo. Note the exceptional similarity. (Elliptical veloci- 
ties from the work of John Huchra of the Harvard- 
Smithsonian Center for Astrophysics.) 




CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



likely endured such an interaction within the last 
billion years. Interactions and mergers will alter 
the morphology of some galaxies, puffing the disks 
into a spheroidal or an elliptical morphology. The 
interactions will also play a role in driving the 
Virgo cluster toward dynamical equilibrium. 

Star Clusters as Chronometers of 
Galaxy Evolution 

Francois Schweizer 

Many galaxies form and grow in fits and spurts. 
Periods of relatively tranquil evolution are punctu- 
ated by occasional collisions and mergers, during 
which a significant fraction of a galaxy's gaseous 
content can be violently compressed and turned 
into billions of new stars. These stars tend to form 
not only in isolation, but also in clusters that con- 
tain from a few to a few million stars. As observa- 
tions with the Hubble Space Telescope have 
revealed, the most massive and dense of these 
newborn clusters survive even fierce mergers and 
appear as aging globular clusters, akin to the 
splendid but much older globulars that adorn the 
halo of our own galaxy. 

The newborn globular clusters have three proper- 
ties that make them near-ideal chronometers for 
studying galaxy evolution: (1) they are highly 
luminous and easily identified even in distant 
galaxies; (2) their stars are coeval, producing spec- 
tral signatures whose time evolution is well under- 
stood; and (3) their expected lifetimes are compa- 
rable to, and often exceed, the age of the universe. 
Hence, like tree rings, the age distributions of such 
clusters contain valuable clues about the past star- 
formation history and growth of the host galaxies. 

Clusters between 100 million and 1 billion years 
old are relatively easy to date because their spectra 
feature strong, age-sensitive absorption lines due 
to hydrogen. Thus, the several hundred young star 
clusters discovered with Hubble in NGC 7252, a 
galaxy formed from two recently merged spirals, 
offer a rich sample for investigation. 

For several years I have, in collaboration with 
others, dated most of these clusters from their 



measured colors and a few from their spectral 
absorption lines. The spectral method is the most 
accurate and yields cluster ages of 400-600 Myr 
(million years), telling us that vehement star for- 
mation occurred during a 200-Myr time interval 
beginning about 170 Myr after the close collision 
that started the galaxies' merger. 

During the past year, we extended our efforts at 
deriving merger chronologies from cluster ages to 
both a younger, still ongoing merger and a sus- 
pected several-billion-year-old remnant. In collab- 
oration with a team led by former DTM fellow 
Brad Whitmore (now at the Space Telescope 
Science Institute), we analyzed Hubble images of 
The Antennae, a spectacular pair of colliding spi- 
rals that have given birth to over 1,000 clusters so 
far. Our observations reveal peaks in the age distri- 
bution of the young clusters at about 500, 100, and 
less than 10 Myr, apparently reflecting the episod- 
ic nature of star-formation bursts in this still accel- 
erating merger. 

Among the youngest globular clusters some are 
truly gigantic, such as the 7-Myr-old "Knot S" 
depicted in Figure 2. This cluster dwarfs the most 
massive globular of our galaxy, co Cen, by factors 
of 7 in size and 200 in luminosity. If placed at 



1 



300 lyr 



# 




Fig. 2. Young globular cluster "Knot S," in The Antennae 

Galaxies, is imaged here with the Hubble. This huge cluster's "^ 

outskirts extend beyond the image boundaries. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp I page I Op 



co Cen's distance, Knot S would appear 7° in diam- 
eter, 10 times brighter than the Large Magellanic 
Cloud, and peppered with dozens of fifth-magni- 
tude stars. This cluster's glory may, however, be 
short-lived. As it ages the stars will fade, and its 
huge envelope — currently extending over nearly 
3,000 light-years — may be whittled away by tidal 
forces. Hence, over the next 10 billion years Knot 
S may still come to resemble to Cen in luminosity 
and size. 

At the other end of the age scale, some of the glob- 
ular clusters in the elliptical galaxy NGC 3610 
seem to show weak but measurable signs of similar 
former glory. In April 1999, we obtained — in col- 
laboration with Jean Brodie of Lick Observatory, 
her student Linda Schroder, and Patrick Seitzer of 
the University of Michigan — exploratory spectra of 
seven clusters with the Keck II telescope on Mauna 
Kea. .Though the data reduction is still in progress, 
two of the seven clusters already seem to show 
enhanced absorption lines due to hydrogen, sug- 
gesting ages of only 1.5-3 billion years. If con- 
firmedby our planned follow-up observations, this 
would make NGC 3610 the first elliptical known 
to possess intermediate-age globular clusters and 
would add to other evidence that it formed from a 
major merger a few billion years ago. The new gen- 
eration of large telescopes, and Magellan I and II in 
particular, will — I hope — greatly facilitate the 
unraveling of galaxies' star-formation histories from 
the fossil record contained in their globular clusters. 

Star Formation in Radio Galaxy 
Centaurus A 

John A. Graham 

I am currently engaged in studying star formation 
occurring under unusual circumstances in the near- 
by radio galaxy Centaurus A (Cen A). I am working 
on this project with Caleb Fassett, who was a sum- 
mer intern at DTM in 1999 and is now at Williams 
College. The radio emission from giant galaxies 
such as Cen A fills an enormous volume, making 
them among the largest objects in the universe. 
Located about 10 million light-years from us, the 
whole Cen A structure stretches over several 
degrees in the sky. Maintaining the huge energy 



output over astronomical timescales has always been 
a problem, and it is currently believed that they are 
powered by particle jets, which stream at relativistic 
velocities from the central core of the galaxy. 

Cen A, although close, is a comparatively mild 
example of the class, and the radio jet is directly 
observed only close to the active nucleus of the 
galaxy. Farther out, it makes its presence known 
by impacting a stray cloud of dust and gas. Some 
of the gas is entrained in the jet and shocked into 
visibility by the impact. It is seen as a long stream 
of faint filaments (Fig. 3). The cloud is probably 
quite clumpy, and some material is compressed by 
the impact to the extent that gravitational cloud 
collapse is triggered and loose chains of young, 
luminous blue stars are formed. I have discussed 
characteristics of the gas in a recent paper, and the 
ongoing work with Fassett consists of obtaining 
brightnesses and colors of the blue stars as a means 
for estimating their ages and predicting their ulti- 
mate destinies. 




Fig. 3. The radio galaxy Centaurus A is shown with contours 
of the inner radio structure at 1407 MHz superposed. The 
outer radio lobes extend far beyond the confines of this illus- 
tration. The direction of the radio jet is indicated by the ori- 
entation of these inner radio lobes. Shown as a single broad 
white contour is the outer boundary of a neighboring cloud 
of dust and gas. Note the extended filamentary emission from 
gas entrained and excited by the radio jet. The square box 
shows the location of a region where shock-triggered star 
formation is observed. 



CARNEGIE INSTITUTION 



page 110 YEAR BOOK p8~pp 




The field we are investigating is outlined by the 
square in Figure 3. We use images taken with a 
2,048 x 2,048 CCD detector on the du Pont 2.5- 
m telescope at Las Campanas Observatory. Images 
were obtained with U, B, and V filters to obtain 
color information. A blue image, shown as Figure 4, 
indicates the locations of the main concentrations 
of blue stars. Reduction of the observational 
material has been carried out with the software 
developed for the Hubble Space Telescope Key 
Project on the Distance Scale of the Universe 
(see Freedman entry in the Observatories' section). 
The brightest blue stars in the loose groups are 
close to magnitude 20 and are evidently quite 
normal and similar to the brightest stars in the 
Large Magellanic Cloud. Ages can be computed 
by interpolation of theoretical stellar models. A 
significant age range is indicated, extending from 
less than a million to more than 15 million years. 

To maintain the observed energy in the radio 
lobes, the radio jet must be long-lived, with a life- 
time of many millions of years at least. We thus 
have the unusual situation in which shocked gas 



and the stars resulting from triggered cloud-core 
collapse can be seen at the same time. In the more 
local situation in our galaxy, star formation is 
believed to be triggered by shocks generated in 
supernova outbursts. In such a case, however, the 
supernova, its remnant, and the attendant shocks 
have long disappeared by the time the new stars 
manifest themselves about a million years later. In 
Cen A, in contrast, because of the long life of the 
radio jet, we can see both the triggering mecha- 
nism and the consequent star formation at the 
same time. 

Upsilon Andromedae and Multiple- 
Planet Systems 

Paul Butler 

The rich diversity of planets in the solar system 
display an astonishing range of environments, 
from surface temperatures high enough to melt 
lead on Venus to the frozen rings of Saturn. Yet to 
first order, one can accurately describe the solar 
system as consisting of the Sun, Jupiter, and some 
leftover debris. If alien astronomers are looking at 
the solar system with technologies similar to our 
own, they will detect only the Sun and Jupiter. It is 
therefore not surprising that the first rush of extra- 
solar planet discoveries have all been of single- 
planet systems. 

Over the last four years, about 30 planets have 
been discovered orbiting nearby Sun-like stars 
(Fig. 5). My collaborator Geoffrey Marcy, of the 
University of California at Berkeley, and I have 
found two-thirds of these using the "precision 
Doppler technique." An orbiting Jupiter-mass 
planet will gravitationally tug its parent star in a 
small counter orbit. This stellar wobble can be 
detected via the Doppler effect acting on the star's 
light. The planets discovered to date have orbital 
periods of a few days to a few years, and most of 
these planets reside in eccentric orbits. None of 
these planets reminds us of our own solar system, 
with giant planets in elegant circular orbits with 
periods of a decade or longer. And none of the 
systems found prior to 1999 has yielded more 
than one planet. 



;arnegie institution 



YEAR BOOK p8~pp page III 



HD187123 

HD75289 

TauBoo 

51Peq 

UpsAnd 

HD217107 

HD130322 

55Cnc 

GLB6 

HD19S019 

GLB76 

RhoCrB 

HD1 68443 

HD1 14762 

70Vir 

Iota Hor 

HD210277 

16CygB 

47UMa 

UHer 



ft. 0.57 M, 


ft. 0.42 Mj 


0m it*. 


a. 0.4HJ, 


m* o-mij 


• MVj 






. 4.4 W, 




ft • 1.2 M, 


• • t-Olf, 


a ■ 0.S5M, 


a . *stn, 


a * 3.4 M, 


a • *-i *, 


a • »•'*, 


a • somj 


a • »• «j 


a » 7.4 M, 


a • 2-2W, 


a • ^m, 


a • '-smj 






• 


2.3 M, 






a • 3.3 M, 





* 


2 






3 



Orbital Semimajor Axis (AU) 



Fig. 5. Known extrasolar planets are shown as a function of 
orbital distance. 



The discovery of a true multiple-planet system 
with current state-of-the-art technology requires a 
combination of measurement precision, patience, 
and Tuck. Reliable detection of an extrasolar planet 
by the precision Doppler technique requires that 
observations span a time covering at least two 
orbits. Since the longest-running precision 
Doppler program is only 12 years old, systems in 
which the outer planet has a period longer than 6 
years would not yet be detectable. With this limi- 
tation, only those systems of multiple Jupiter-mass 
planets orbiting within 4 AU (1 astronomical unit 
= Earth- Sun distance = 93 million miles) of the 
parent star can be detected. 

Upsilon Andromedae, the only confirmed system of 
multiple extrasolar planets, meets these conditions. 
Marcy and I have observed Upsilon Andromedae at 
Lick Observatory for the past 12 years. In June of 
1996, we announced the presence of a planet in a 
scorching hot, 4.6-day orbit with a minimum mass 
of 0.7 Jupiter-masses (Fig. 6). Like the handful of 
other "51 Peg-like" planets with orbital periods of 
less than 5 days, the orbit is circular. The discovery 
paper noted evidence for additional longer-period 
planets. 

Because of these suspicions, the Lick group and 
the Advanced Fiber Optic Echelle (AFOE) group 
(led by Robert Noyes at Harvard) independently 
monitored the Doppler velocity of Upsilon 



> 



150 


, , | , i , | i , , | 
- Mass = 0.72 M JUP /slni 


P = 4.63 day 
K = 74.5 m/s 
e = 0.1 1 


100 


l\ i\ i\ l\ i\ 


1 \ l\ \ 1 ~ 


50 




11 - 





- \ j \ If \ If 




-50 


; RMS = 7.84 m/s 

. . i i 


■ ■ ' 



0.94 



0.96 0,98 1.00 

Time - 1995 (Years) 



1.02 



Fig. 6. These are the discovery data for the inner planet with 
a 4.6-day period in the Upsilon Andromedae system, from 
December 1995 to January 1996. 



Andromedae as often as possible. By early 1999, 
more than 140 observations had been collected, 
allowing the complicated pattern of Doppler 
velocities to be untangled into two additional 
planets (Fig. 7). The middle planet in this system 
has 2 Jupiter-masses in a 240-day orbit; the outer 
planet has 4 Jupiter-masses in a 3.5-year orbit. 
Both the outer two planets are in eccentric orbits, 
as are all of the extrasolar planets that orbit more 
than 0.2 AU from their host stars. 



to 

i 

"mm 

3 
cc 

§ 

i 





Upsilon Andromedae: Outer Two Planets 


150 
100 




50 


-J\L |\a h 



-50 


\ \r im 


100 
150 


'■ 4.6-day Planet \\ V 
Removed. , \ 



1992 



1994 



1996 
Time (yr) 



1998 



2000 



Fig. 7. The discovery data for the outer two planets in the 
Upsilon Andromedae are shown here, with the Doppler 
velocities of the inner planet removed. 




CARNEGIE INSTITUTION 



page 112 I YEAR BOOK ?8~pp 



With the possible exception of the companion to 
47 Ursae Majoris, all of the extrasolar planets 
found to date are either "51 Peg-like" or eccentric. 
In the Upsilon Andromedae system we have both 
types of planets, perhaps making this a Rosetta 
stone that will allow us to understand the forma- 
tion and evolution of these alien planetary systems. 
As the existing Doppler survey programs improve 
their precision, time baseline, and sample size, 
many more multiple-planet systems will be found. 

Over the next 10 years, the precision Doppler 
technique will continue to provide the bulk of the 
extrasolar planet discoveries. Within the past three 
years, Marcy and I have increased the size of our 
survey from 100 stars to 1,100 stars using tele- 
scopes in both the northern and southern hemi- 
spheres, including the biggest telescope in the 
world — the 10-m Keck. By 2010 these surveys will 
provide the first hints about the fraction of plane- 
tary systems similar to the solar system, with giant 
planets orbiting out to 5 AU and beyond. These 
surveys will ultimately point the way to advanced 
technology missions (such as the proposed NASA 
Terrestrial Planet Finder) that will directly image 
Jupiter-like and Earth-like extrasolar planets, and 
ultimately take their spectra. 

Rapid Gas Giant Planet Formation 

Alan P. Boss 

As noted above, over two dozen gas giant planets 
have been detected in orbit around nearby stars, 
most of them discovered by Paul Butler and his 
colleagues. These discoveries have highlighted the 
unsatisfactory state of our knowledge about how 
gas giant planets like Jupiter formed. Two mecha- 
nisms have been suggested for forming gas giant 
planets, core accretion and disk instability. Core 
accretion is the generally accepted mechanism, but 
if disk instability is possible, it will occur well 
before core accretion can even get started. 

The core- accretion model of giant planet formation 
presumes the collisional accumulation of a roughly 
15-Earth-mass core of ice and rock, which then 
accretes hydrodynamically an envelope of hydrogen 
and helium gas. However, recent models of the 



interiors of Jupiter and Saturn require considerably 
smaller core masses than were previously thought, 
or even no core at all. Given the additional difficulty 
of growing a Jovian-mass planet within the expect- 
ed lifetime of the solar nebula (a few million years 
at most), it seems prudent to investigate other 
mechanisms for giant planet formation as well. 

The only viable alternative appears to be the disk- 
instability mechanism, where a gravitationally 
unstable disk breaks up into clumps of gas and 
dust that can contract and become giant gaseous 
protoplanets. The disk-instability mechanism can 
lead to core formation by rapid sedimentation of 
dust grains as the protoplanet slowly contracts 
toward planetary densities. Because the instability 
occurs over a timescale of about 1,000 years, there 
is no danger of losing the disk gas before the giant 
gaseous protoplanets form. However, the instabili- 
ty requires a disk that is massive enough and cold 
enough to become gravitationally unstable. Disk 
instability may be able to explain the formation of 
massive giant planet systems like that of Upsilon 
Andromedae, described by Paul Butler. 

In order to study further the disk-instability mech- 
anism, I have calculated the evolution of a number 
of three-dimensional (3D), gravitational-hydrody- 
namical models of protoplanetary disks starting 
from realistic initial temperature and density pro- 
files. The 3D models show that a clump-forming 
disk instability can occur in marginally unstable 
disks with masses as low as 4% of a solar mass 
inside a radius of 10 AU and perhaps even in disks 
with somewhat lower masses. However, the disk 
mass seems to need to be greater than about 1% of 
a solar mass inside 10 AU. Models with doubled 
radial extent show that the outer boundary condi- 
tions on the calculations have little effect on the 
results. This implies that clump formation may be 
limited to an annulus in orbital radius between 
about 5 AU and 12 AU, with the usual outcome 
being two multiple-Jupiter-mass clumps within 
this annulus (Fig. 8). These 3D models suggest 
that a protoplanetary disk with a mass at the high 
end of the range (1% to 7% of a solar mass), con- 
sidered possible for the minimum-mass solar neb- 
ula, could quickly lead to the formation of two 



;arnegie institution 



YEAR BOOK p8~pp I page IIJ 




Equatorial density after 2,200 years is 
shown for a disk with a mass 1 0% that of 
the Sun. The region illustrated has a radius 
of 20 AU. The surface density in this rela- 
tively low-mass disk is comparable to that 
required for runaway accretion in core 
accretion models. The lightest area is high- 
est density. Spiral arms have grown and are 
being sheared by differential rotation into 
thin filaments. 



This image shows the equatorial density 
after 3,000 years for the same disk. The 
spiral arms have grown around 8 AU and 
have formed a double clump. These clumps 
are sweeping up the gas at their orbital 
radius, forming a thin gap (black arcs). The 
two clumps soon thereafter merge. A 
solar-mass protostar wobbles unseen at 
the center of the disk in reaction to the 
clumps. 



Equatorial density after 3,500 
years is seen for the same disk, 
about 17 orbital periods (at 10 
AU) later than the previous figure. 
The first clumps have helped stim- 
ulate the growth of another clump 
with a radius of around 7 AU, and 
the merged first clump has moved 
outward to 10 AU in response. 
Both clumps have cleared wide 
gaps in the disk, and should con- 
tract to form gas giant planets 
with initial orbital radii similar to 
those of Jupiter and Saturn. 



giant gaseous protoplanets, one at about 6 AU and 
one at about 12 AU. The terrestrial and outer 
planets could then form much later by the usual 
process of collisional accumulation of solids, a 
process that has been studied in most detail by 
George Wetherill. 

Disk instability thus seems to be possible in disks 
with total masses comparable to that inferred for 
the solar nebula, and indeed comparable to the 
disk masses that seem to be required in order for 
core accretion to produce giant planets in a few 
million years. Clearly if a disk instability can occur, 
it will outpace core accretion. 

Formation of the Asteroids 

George W. Wetherill 

On the same day that I sat down to write this brief 
essay, I learned by e-mail of the death of the 
Russian astronomer Victor Safronov, who during 
the 1960s created the modern epoch in the study 
of the physical processes by which planets are 
formed. I wouldn't be doing this work if it had not 



been for his inspiration. One of his minor contri- 
butions was to introduce the biological term 
embryo to describe the bodies that were to grow 
into planets. This tradition can be extended to 
describe the development of this science itself. It 
has passed through the stages of infancy and'child- 
hood, when these processes seemed relatively easy 
to understand. On the way to maturity, we are 
now experiencing a confusing and difficult period 
of "adolescence," in which nothing seems to work 
as well as it did a decade earlier. Ironically, this is a 
natural consequence of the great advances that 
have been made in understanding the dynamic 
processes involved, the ability to test complex 
models with readily affordable desktop computers, 
the new theoretical and observational discoveries 
in the area of star formation, and the first actual 
observation of the planetary systems of other stars, 
a field in which our new Staff Member, Paul 
Butler, is a pioneer. Many enigmas have been 
revealed by these more advanced discoveries. 

A major difficulty is that in our solar system all of 
these events took place 4.5 billion years ago. All of 



CARNEGIE INSTITUTION 



page II4 I YEAR BOOK p8~pp 



the larger planets have experienced major changes 
since their formation, and even for the Earth, the 
only planet that has been studied in much detail, 
the essential record of its earliest history has been 
very badly obscured by later events. Thus the plan- 
ets provide little "ground truth" for testing theories. 

Nevertheless, well-preserved samples of rocks that 
were formed within the first few million years of 
the formation of our Sun are readily available and 
are being studied by use of precise technology in 
laboratories throughout the world, including the 
isotope cosmochemists in this department. These 
samples are the meteorites. A small number of 
these are known to be rocks blasted from the 
Moon and Mars by impacts of asteroids and 
comets. The great majority are fragments of aster- 
oids themselves. Asteroids are small planets, rang- 
ing up to about 1,000 km in diameter. Most of 
their orbits lie between those of Mars and Jupiter. 
Because of their small size, they have been spared 
the geological processes that have obscured the 
early history of the larger planets. As a result, they 
still have a "memory" of the circumstances under 
which they and the other planets were formed. 

It is not possible to simply "invert" the meteoritic 
data and infer events in the early solar system. 
Rather, it is necessary to "forward model" quantita- 
tive alternative plausible scenarios of asteroid for- 
mation, and compare the consequences of these 
models with the record preserved in the meteorites. 

Rather little attention has been given to this oppor- 
tunity. One such study is an extension of earlier 
calculations I published in 1992. These have now 
been repeated by the use of greatly improved com- 
putational facilities, as well as software developed 
by a former DTM postdoctoral associate, John 
Chambers, who is now on the staff of the Armagh 
Observatory in Northern Ireland. This work has 
been published during the past year. Chambers and 
I have written a paper concerning the processes in 
the asteroid region during the early solar system. It 
examines the consequences of the "standard model" 
of planet formation and shows that not only the 
inner planets, but unobserved planets in the aster- 
oid region as well, would grow to about the size of 



Mars in less than a few million years. In this stan- 
dard model, Jupiter and Saturn become gas giant 
planets somewhat later. We then find, thank good- 
ness, that gravitational interactions between these 
"asteroid planets" and Jupiter and Saturn quickly 
remove these presently nonexistent large bodies in 
the asteroid region, leaving only residual small bod- 
ies that represent the observed asteroids, the 
sources of the meteorites. 

At the same time, present DTM postdoctoral 
associate Stephen Kortenkamp and I are develop- 
ing an alternative model to permit comparison 
with these consequences of the standard model. 
This model makes use of the computations made 
by Alan Boss that imply that the giant planets dis- 
covered by Paul Butler and others could have 
formed very rapidly, during the later stages of the 
formation of their central star. Boss has suggested 
that Jupiter and Saturn may have formed by this 
same mechanism (see above), thereby avoiding 
some serious difficulties with the standard model. 
We are also examining whether this alternative 
model also permits the formation of small aster- 
oids and the inner terrestrial planets. At present 
our answers to these questions are "maybe" and 
"probably." We are trying to provide better 
answers and to infer the consequences of such 
alternative models, with regard to the unique 
information preserved in the meteorites, as well as 
their asteroidal parents that are at present targets 
for observation by spacecraft. 

The Formation of Chondrules 

Conel M. O'D. Alexander 

At 4.55 billion years in age, chondritic meteorites 
are the oldest known rocks in the solar system. 
When looked at in detail, they appear to be essen- 
tially sedimentary rocks and are made up of primi- 
tive materials that formed in the first 10 million 
years or so of the solar system. This was when the 
solar nebula — the disk of gas and dust that sur- 
rounded the young Sun — was still present and dust 
was beginning to accumulate into planets. If we can 
only decipher them, chondrites will provide us with 
a window into processes that occurred in the nebu- 
la during this important but distant period. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 11$ 



The most abundant of the materials in chondrites 
(50-80% by volume) are chondrules. These are 
millimeter-size spherical objects that appear to 
have formed as free-floating molten droplets in the 
nebula. Melting material with their compositions 
requires temperatures of 1500-1800°C. Clearly the 
process that formed them was very energetic. If 
their abundance in chondrites is any guide, chon- 
drule formation was one of the most energetic 
processes in the nebula, at least in the region of 
the asteroid belt between Mars and Jupiter where 
the chondrites come from. 

Despite having been studied for over 100 years, 
there remains no consensus on what the energy 
source was for making chondrules. More progress 
has been made in trying to pin down the condi- 
tions under which chondrules formed, however. 
Simulation experiments of chondrules suggest that 
they were rapidly heated to near their total melting 
temperatures (1500-1800°C) and then cooled at 
100-1000°C/hr. The cooling rate of a millimeter- 
size droplet radiating freely into space at such high 
temperatures would be at least 100 times faster 
than these estimates. To slow the cooling rates 
probably requires that the chondrule-forming 
regions were fairly large and dusty. How large and 
how dusty remains very uncertain. 

At present, we have few independent means of 
determining conditions in the nebula, such as dust 
densities or gas pressure, and we must rely on 
astrophysical models for estimating them. 
Pressures in the nebula were probably low, about 
10 3 -10~ 6 atmospheres. At these pressures and at 
the high temperatures of chondrule formation, 
many elements become volatile. The degree of 
volatility of some elements can be very sensitive to 
the conditions, such as gas pressure. Therefore, it 
might be possible to constrain nebular conditions 
if we can determine the degree of volatile loss of 
one or more elements. During evaporation, the 
heavy isotopes of an element become increasingly 
enriched in the residue, in this case the chondrule. 
The isotopic composition of an element can there- 
fore be a sensitive indicator of the degree of evapo- 
rative loss. I have been developing techniques for 
making precise isotopic measurements of four ele- 



ments, potassium, iron, magnesium, and oxygen. 
These elements will have had quite different 
volatilities during chondrule formation. 

The potassium and iron isotope measurements 
were made with the DTM's ion microprobe in 
collaboration with Jianhua Wang. The magnesium 
isotopes were measured with the DTM's new 
Plasma 54 multicollector inductively coupled plasma 
mass spectrometer (MC-ICP-MS) in collabora- 
tion with Richard Carlson, Timothy Mock, and 
summer intern Lan-Anh Nguyen. Joint DTM- 
Geophysical Laboratory- Smithsonian Institution 
fellow Richard Ash made the oxygen isotope mea- 
surements with the laser fluorination system devel- 
oped by Douglas Rumble. 

The picture that emerges from these four elements 
is still hazy. The two most volatile elements, 
potassium and iron, show no evidence of evapora- 
tive loss; the more refractory magnesium exhibits 
isotopic fractions consistent with small degrees of 
loss; and oxygen seems to have undergone isotopic 
mixing between two reservoirs with quite different 
isotopic compositions but not the isotopic frac- 
tionation associated with evaporation. There are 
conditions under which the fractionation associat- 
ed with evaporation can be suppressed in some 
elements. The challenge is to explain the results 
for all four elements, a task that will require 
detailed numerical modeling. 

Coupling between Climate Change and 
Tectonics on Venus 

Sean C. Solomon 

Planets have considerable internal energy, and the 
processes of energy transport and loss drive long- 
term changes. Understanding the differences in 
evolution among the planets of our solar system 
poses a considerable challenge. A particularly 
interesting puzzle has been Venus, in size and in 
bulk composition the planet most similar to Earth. 
One important difference in the two planets is 
their climates. The dense carbon dioxide atmos- 
phere and global cloud cover have turned Venus 
into an efficient greenhouse, trapping solar radia- 



CARNEGIE INSTITUTION 



page Il6\ YEAR BOOK p8~pp 



tion and rendering the modern surface tempera- 
ture a searing 740 K. Another difference is in their 
volcanic and tectonic history. Lacking Earth-like 
plate tectonics, Venus shows evidence for wide- 
spread resurfacing of the planet about 500 million 
years ago as well as globally coherent episodes of 
deformation that appear to have been concentrated 
over short intervals of the preserved geological his- 
tory. Recent work of mine, carried out with collab- 
orators Mark Bullock and David Grinspoon at the 
Southwest Research Institute, suggests that these 
two aspects of the evolution of Venus may be 
strongly coupled. 

Bullock and Grinspoon have shown that the cli- 
mate of Venus is unstable with respect to a very 
large volcanic eruption, because such an event 
would release into the atmosphere significant 
quantities of water and sulfur dioxide from the 
erupting lavas. Water and sulfur dioxide are green- 
house gases that modify the radiative balance in 
the atmosphere; their abundance also affects 
strongly the distribution of sulfuric acid-water 
aerosols that make up the Venus clouds. There are 
important sinks for both species: photodissociation 
of water molecules and loss of hydrogen to space, 
and chemical reaction of sulfur dioxide with sur- 
face and near-surface minerals. Climate models 
incorporating all of these processes indicate that 
for a sufficiently large eruption the excursions in 
surface temperature accompanying changes to the 
greenhouse and to the global cloud cover can 
exceed ±100 K and can extend over periods from 
tens to hundreds of millions of years. 

Such temperature changes over these timescales 
diffuse deep into the interior of a planet. 
Differential temperature changes of this magni- 
tude expand or contract surface and near-surface 
material by amounts sufficient to fracture rock. 
Climate change on Venus is therefore capable of 
affecting the deformation of the surface and the 
global distribution of tectonic features. 

We tested this idea by examining the climate 
change that would have followed the emplacement 
of the largest distinct episode of widespread vol- 
canism known to have occurred on Venus: the 






i i i i | i i i i 1 i i i i 1 i i i i 1 i i i i 1 i 


i i i 1 i i i i 


40 


/ 


^^^ 


20 


/ 


- 





>t> Extension / 


- 


,A -v Compression / 


- 


-20 




- 


-40 




- 


-60 




- 




i i i i 1 i i i i 1 i i i i 1 i i i i 1 i i i i 1 i 


i i i I i i i i 



300 400 

Time (My) 



Fig. 10. The predicted evolution of surface horizontal stress 
resulting from the climate change that accompanied and 
followed emplacement of ridged plains lavas is depicted 
here. The compressive stresses that accumulated in the first 
100 million years of the model would have been sufficient to 
produce widespread faulting manifested in the formation of 
wrinkle ridges. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page IIJ 



eruption of the ridged plains. These plains, making 
up 60-65% of the present surface, are characterized 
by pervasive wrinkle ridges (Fig. 9), produced by 
horizontal shortening of the lithosphere. The vol- 
ume of lavas that erupted to form the plains, on the 
basis of area and relief of buried topography, was at 
least 2 x 10 8 km 3 , as much as an order of magnitude 
greater than even the largest of the major igneous 
provinces on Earth. Widespread ridge formation 
evidently occurred less than 100 million years after 
the plains were emplaced, on the grounds that only 
about 1% of impact craters on these plains have 
been deformed by the wrinkle ridges. The change 
in surface horizontal stress predicted to accompany 
the climate change that would follow eruption of 
the ridged plains lavas is of the correct sign and 
magnitude to account for a narrow interval of time 
between plains emplacement and wrinkle ridge for- 
mation (Fig. 10), as observed. 

Many further tests are in progress. These include 
exploring the sensitivity of climate models to 
changes in key parameters, incorporating a fuller 
description of the known volcanic flux history of 
the planet, and exploring whether other apparently 
global episodes of coherent contractional or exten- 
sional deformation might also be the result of 
stresses induced by climate change. What is 
already apparent is that climate change on Venus 
has been much more pronounced than the "global 
warming" that heats political debates on this plan- 
et, and that the coupling between climatic and tec- 
tonic change may be a major contributor to the 
distinct evolutionary tracks of Venus and Earth. 

Water in the Hawaiian Mantle Plume: 
Where Did It Come From and Where 
Did It Gol 

Erik H. Hauri 

Water plays a highly significant role in the genera- 
tion and differentiation of magmas in a variety of 
planetary environments. Water dissolved in miner- 
als in the deep Earth can strongly lower both the 
melting temperature and the viscosity of rock. At 
high abundances, water can also determine, in 
large part, many of the physical properties of mag- 
mas that influence eruption dynamics. The pres- 



ence of liquid water at the Earth's surface is also 
thought to be a primary factor that enables the 
persistence of active plate tectonics. 

The primordial conditions under which the Earth 
formed were probably very hot, perhaps hot 
enough to have melted much of the planet. As a 
result, the Earth's interior was depleted in volatile 
elements during accretion and has lost volatile ele- 
ments throughout its history by the eruption and 
degassing of magmas at locations of active volcan- 
ism. On other planets, the water expelled from 
volcanoes is either lost to space by a variety of 
physical and chemical mechanisms — such as on 
Mercury and Venus — or may be partly frozen as 
ice and trapped in the crust, as on Mars. However, 
temperature conditions on the Earth's surface 
favor the stability of liquid water. Geophysicists 
have long recognized the lack of active plate tec- 
tonics on the other terrestrial planets. This obser- 
vation has led to the idea that water from the 
Earth's surface is carried into the interior by plate 
subduction and serves as the lubricant that facili- 
tates plate tectonics. Water-rich explosive volcan- 
ism occurring at subduction zones confirms that 
water is carried down with the descending plate. 
But two major questions about the water budget at 
subduction zones remain unanswered: How much 
of the water that goes down into subduction zones 
comes back up at subduction-zone volcanoes, and 
how much water is left in the subducting plate that 
is carried into the deep Earth? The answers to 
both of these questions will constrain the amount 
of water that is left in the upper parts of the 
Earth's mantle to lubricate plate tectonics. 

To address the second question about water 
trapped in the subducting plate, I am measuring 
the abundance and isotopic composition of water 
in magmas from the Hawaiian Islands. Our previ- 
ous geochemical work on Hawaii has shown that 
certain Hawaiian volcanoes (Koolau, Mauna Loa, 
Mauna Kea) contain a component made up of 
recycled oceanic crust and sediment that had been 
carried into the deep mantle during an ancient 
subduction episode. Oxygen isotope work on these 
same samples, carried out with collaborators at the 
California Institute of Technology and the 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp 



University of Wisconsin, showed convincingly that 
these components had interacted with water near 
the Earth's surface. We therefore selected one of 
these volcanoes (Koolau) to initiate our study. 

Magmas that erupt on the Earth's surface lose 
their water through degassing. Only those that 
erupted at ocean depths greater than 500 meters 
cool quickly enough to retain their original volatile 
contents. Another way of examining volatiles in 
magmas is to study tiny inclusions of melt, which 
are trapped in solid crystals that have grown from 
the magma before eruption. Because the crystal 
surrounding these inclusions acts as an inert cap- 
sule, melt inclusions can preserve a record of the 
behavior of volatiles deep within the volcanic sys- 
tem even when they are contained in lava samples 
that have erupted on the Earth's surface and lost 



upper oceanic crust 

(8 18 > +6 %o) 
(6D>^ 



lower oceanic crust 
and lithospheric mantle 

(6 18 < +6 %c) 
(8D> -50% o ) 



sediments (5 18 = +20 % c ) 
(8D = %c) 




Subduction 

Volcanoes 

5D = -20%, 



Dehydration 



8D% -so 

-100 



4.6 5.0 .5.4 5.8 62 
8 18 % 



Fig. I I . The upper crust and lower crust of the oceanic plate 
interact with seawater at different temperatures, resulting in 
changes in their average oxygen and hydrogen isotope ratios. 
Addition of seawater-derived sediments (down arrow at top) 
adds material with high oxygen isotope ratios and high water 
contents. During subduction, some of the water is transport- 
ed into the mantle source of subduction-zone volcanoes by 
dehydration, while the water remaining in the subducted 
plate is recycled (curved arrow) and returns to the surface 
in mantle plumes such as Hawaii. This cycle results in correla- 
tions between oxygen and hydrogen isotopes in Hawaiian 
magmas (inset). 



their own volatiles. These inclusions have been 
measured for their volatile abundances (H 2 0, 
C0 2 , F, S, CI) and hydrogen isotope ratios using 
the DTM ion microprobe. 

The melt inclusion results for several Hawaiian 
volcanoes (Loihi, Kilauea, Mauna Loa) show mod- 
erate water contents and hydrogen isotopes, which 
generally agree with the data on submarine erup- 
tions on these same volcanoes. The H 2 and CI 
data on melt inclusions reveal that many magmas 
are contaminated by seawater-derived components 
prior to eruption, a process which changes their 
original CI, H 2 0, and hydrogen isotope composi- 
tions. The Koolau melt inclusions, however, are 
characterized by the lowest abundances of H2O, S, 
and CI ever observed for any undegassed Hawaiian 
magma, and these low abundances are coupled 
with the lowest hydrogen isotope ratios ever 
observed at Hawaii (Fig. 11). The combined 
volatile data sets for melt inclusions and submarine 
eruptions show a correlation of hydrogen isotope 
ratio with other isotopes measured on the same 
samples, including oxygen isotopes. 

The lavas from the Koolau volcano contain the 
largest amount of the water-altered recycled 
oceanic crust component, yet they appear to have 
the lowest abundances of volatiles. This observa- 
tion is best explained if the recycled plate was 
extensively dehydrated during the ancient subduc- 
tion episode that introduced this component into 
the deep mantle. The observed hydrogen isotope 
ratios for Koolau are consistent with hydrogen iso- 
tope changes expected during dehydration of a 
subducting plate containing hydrous minerals. 
These observations lead us to conclude that sub- 
duction dehydration is very efficient, with the 
result that nearly all of the water that goes down 
into subduction zones is released from the 
descending plate and transported into the zone of 
magma generation beneath subduction-zone vol- 
canoes. The amount of water left in the mantle 
after subduction-zone volcanism is probably the 
lubricating force for plate tectonics. How much is 
left? Answering this question will require similar 
ion-probe studies of melt inclusions from subduc- 
tion-zone volcanoes. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp I page lip 



Rhenium-osmium (Re-Os) Studies of 
Sulfide Inclusions in Diamonds from 
the Orapa Kimberlite, Kaapvaal 
Craton, Botswana 

Steven B. Shirey 

Sulfides, chiefly of iron (Fe) but also with subordi- 
nate nickel (Ni) and copper (Cu), are common 
inclusion minerals in diamond that occur in two 
basic assemblages: peridotitic (p-type) and 
eclogitic (e-type). At DTM the recent develop- 
ment, by former fellow Graham Pearson, Richard 
Carlson, and me, of microchemical techniques for 
the analysis of the rhenium-osmium isotopic com- 
positions of single sulfide inclusions at 10 15 gram 
levels has led to detailed geochronology on indi- 
vidual diamonds that contain either inclusion 
assemblage. Apart from the obvious economic 
importance of such work to diamond exploration, 
any materials encased in diamonds provide a 
unique geological sample of mantle minerals that 
have been isolated from chemical exchange since 
diamond growth. Diamond distribution on Earth 
is closely linked to the distribution of continental 
mantle keels. Thus, an important focus of this 
research is to compare diamond growth episodes 
to geological processes such as continental core 
(craton) stabilization and much later continent- 
margin accretion via subduction to understand the 
role of continental keels in continent development. 

A Re-Os isotopic study of sulfide inclusions in dia- 
monds from the 93-million-year-old Orapa kim- 
berlite in Botswana is under way. The Orapa kim- 
berlite is host to one of the world's largest and most 
productive diamond mines and is situated on the 
northwest side of the ancient continental core mak- 
ing up southern Africa called the Kaapvaal craton. 
Orapa is noted for its well-exposed kimberlite (the 
diamond host rock), its diamond-bearing and non- 
diamond-bearing eclogite (high-pressure metamor- 
phosed basalt) xenoliths (rock fragments carried by 
the kimberlite), and the high proportion of sulfide 
and silicate in its diamond inclusion population. In 
general, we want to better understand the age spec- 
trum of diamonds containing e-type sulfide inclu- 
sions at localities such as Orapa, where we can com- 
pare sulfide inclusion ages to previously studied 



eclogitic silicate inclusion ages. A goal is to look for 
other generations of diamond growth, and to 
explore the relationship between the sulfide inclu- 
sions in diamond and their eclogite xenolith hosts 
in ways that can be extended to the larger Kaapvaal 
craton and its geological history. 

The sulfides fall into two groups based on the Re- 
Os isotopic data: one group with a 2,900-million- 
year age and the other with a 990-million-year age 
(Fig. 12). The older age represents the first firm 
Archean age for diamonds containing eclogitic 
materials. This is exciting because it begins to 
resolve the long-standing issue of why there have 
been good examples of old diamond-bearing 
eclogite xenoliths but few examples of old eclogitic 
diamond inclusions of either sulfide or silicate 
type. The younger age is interesting because it is 
identical to the previous 990 million-year-old 
samarium-neodymium isochron age obtained on 
Orapa eclogitic garnet and clinopyroxene diamond 
inclusions. 




c/> 
O 
fe 4.00 L 



| ■ i ■ ' | ■ i ' i | i ■ i i M I i I | 



7 



■ Orapa 

O Koffiefontein 



' * * * * * * ' * ' ■ * ' * * * * ' * * * * * ■ . . 



100 200 300 400 500 600 700 
187 Re/ 188 0s 



Fig. 1 2. This Re-Os isochron diagram shows Orapa and 
Koffiefontein eclogitic (e-type) sulfide inclusions in diamond. 
Each data point represents the inclusion from a single dia- 
mond. Error bars are derived chiefly from blank correction 
uncertainties when analytical concentrations of Os are low 
(e.g., 30- 1 00 x 10 IS grams). Error bars are not shown when 
smaller than symbols. 990 and 2,900 million-year-old (Ma) 
lines are shown for reference purposes. (Koffiefontein data 
from Graham Pearson of the University of Durham and 
coworkers.) 



o 



CARNEGIE INSTITUTION 



page 120 I YEAR BOOK p8~pp 



These data suggest that there were at least two 
episodes of diamond growth in the mantle beneath 
the Orapa area, separated by about 2,000 million 
years. The striking similarity of the older ages to 
the rhenium-depletion model ages on peridotites 
from the Letlhakane kimberlite 40 km to the east- 
southeast of the Orapa kimberlite makes a com- 
pelling argument that continental core stabiliza- 
tion about 2,900 million years ago was accompa- 
nied by oceanic crustal underthrusting to make 
eclogite. The striking similarity of the younger 
ages to the eclogitic sulfide inclusions in diamond 
at the Koffiefontein kimberlite some 800 km to 
the south indicates that eclogite emplacement into 
the cratonic lithosphere 1,000 million years ago 
may be more widespread than previously thought. 

Crustal Deformation and the DTM 
Borehole Strainmeter Program 

Alan T. Linde 

Earthquakes and volcanic activity result from 
changes within the Earth. Those internal changes 
also cause deformation of the Earth's surface. For a 
number of years, working with Selwyn Sacks, 
I have carried out a program of both measuring 
such deformations in tectonically active areas 
and interpreting the data in terms of processes 
at depth. The primary source of data for this 
program comes from Sacks-Evertson borehole 
strainmeters installed in a number of different 
active areas, particularly California, Japan, and 
Iceland. These high-resolution data have allowed 
identification of new processes, such as slow 
earthquakes in seismogenic zones and changes in 
magma reservoirs during episodes of volcanic activ- 
ity, which are not detectable with other techniques. 

Work on this program in the last year has resulted 
in the completion, or near completion, of several 
studies. With Icelandic colleagues Kristjan 
Agustsson and Ragnar Stefansson, we analyzed 
strain changes associated with a moderate (magni- 
tude 5.8) earthquake in southern Iceland. 
Coseismic changes were consistent with the earth- 
quake's parameters determined from seismic waves 
and allowed resolution of spatial variation in the 
slip distribution. Preceding and following the 



earthquake were slow strain changes, which were 
interpreted as being due to magma movement. It 
appears that this earthquake may have been trig- 
gered by an episode of dike growth. 

Our work on slow earthquakes, based on record- 
ings from the strainmeters, led us to reexamine 
reports of slow changes before the great Tonankai 
(1944) and Nankaido (1946) earthquakes along 
the Nankai trough south of Honshu, Japan. The 
evidence for those slow changes came from level- 
ing surveys, tide gauge records, and reports of the 
drying up of water wells. Because such changes 
have had significance in earthquake prediction 
efforts in Japan, we were interested to see if the 
slow changes were consistent with slow earth- 
quakes before the main shocks. Our results show 
that such is the case and that the slow rupture 
takes place on the subduction interface down-dip 
from the seismic rupture zone. This situation, sim- 
ilar to what happened before the 1960 great Chile 
earthquake, is such that the slow events increased 
the shear stress in the seismogenic zone, presum- 
ably triggering the earthquakes. 

New insight into volcanic activity has come from 
analyzing borehole strain data from sites close to 
Hekla, Iceland, and Long Valley, California. Sacks 
and I, together with colleagues Osamu 
Kamigaichi, Kenji Kanjo, and Masaaki Churei of 
the Japan Meteorological Agency (JMA), are ana- 
lyzing the deformations caused by the 1986 erup- 
tion of Miharayama on the island Izu-Oshima in 
Japan. The strainmeters, which recorded that 
activity, are part of a network installed by the JMA 
as part of their earthquake prediction research pro- 
gram. The data show that, during the first stage of 
the eruption, the relatively shallow reservoir 
(which was the ultimate source of magma for the 
eruption) was continuously being replenished from 
a much deeper (about 30 km) source. Additionally, 
the rate of that replenishment was changed at the 
time of small volcanic earthquakes. Strain changes 
preceding the second stage of the eruption were 
clear at distances up to 50 km. Those strain 
changes were due to the formation and propaga- 
tion of dikes from a depth of several kilometers up 
to the surface. Somewhat surprising was the fact 
that most of the magma movement from the reser- 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 121 



voir was not to the surface but rather into a large 
dike that did not break the surface. 

The strainmeter observational program continues 
to be enhanced. Over the next several years, in col- 
laboration with the U.S. Geological Survey and 
the University of California at Berkeley and San 
Diego, about 10 new sites will be instrumented in 
California in the San Francisco Bay area. In the 
summer of 1999, borehole strainmeters together 
with tiltmeters and seismometers were installed for 
the first time in deep drill holes (about 1,100 m) 
below the seafloor, as described at greater length 
below. Data from these sites should yield new 
insight into the processes of plate motion and 
earthquake generation. 

Strain Diffusion from Great 
Earthquakes 

I. Selwyn Sacks 

The motion of the plates in the uppermost Earth 
causes deformation that can lead to failure at the 
interaction boundaries. The deformation results in 
the slow buildup of stresses, but those stresses can 
be released rapidly and possibly catastrophically as 
earthquakes. Recent observations, initially from 
high-sensitivity borehole strainmeters, showed that 
these failures can also occur slowly on the same 
faults that have regular destructive earthquakes. 
The residual stress and the proximity to failure, 
therefore, cannot be estimated without knowledge 
of these slower events. The analyses of data from 
slow events and from volcanic eruptions are dis- 
cussed further in the article above by Alan Linde. 

Also important is another type of slow deforma- 
tion of the Earth's surface due to strain diffusion 
from great earthquakes, volcanic eruptions, or 
spreading events at the separating plate bound- 
aries. This type of deformation propagates across 
the surface at velocities that depend on the dis- 
tance from the source. Near the source, the propa- 
gation velocity is some hundred kilometers per 
year, but at greater distances the velocities decrease 
to only a few kilometers per year. The parameters 
of the elastic crust and those of the viscoelastic 
underlying layers govern this highly dispersive 



propagation rate. Analyses of this slow deforma- 
tion have allowed determination of the viscosity of 
the crust and uppermost mantle for Japan, 
California, and Iceland. Some of these deforma- 
tions can be measured hundreds of kilometers 
from the source even after a century. An important 
consequence of this long-lasting disturbance is 
that the present-day strain field, even from highly 
precise Global Positioning Satellite (GPS) mea- 
surements, cannot be reliably estimated without 
allowing for the effects of past great earthquakes. 

Another key effect of this strain diffusion has 
recently been recognized. The slowly propagating 
strain pulse is capable of unlocking favorably ori- 
ented, highly stressed faults. It does this by reduc- 
ing the force pressing the two sides of the fault 
together, allowing the fault to slip in an earth- 
quake. Former DTM fellow Fred Pollitz and I 
have shown that the highly destructive 1995 earth- 
quake in Kobe, Japan, was likely triggered by strain 
diffusing from great earthquakes in 1944 and 1946. 
And the Tonankai earthquake of 1944, which 
occurred about 50 years earlier than expected, may 
itself have been triggered by strain from a great 
earthquake in 1891. Because of the orientation sen- 
sitivity, strain pulses are also capable of inhibiting 
earthquakes. Since in many active tectonic regions 
there are faults with many different orientations, it 
is possible to calculate the probabilities that for any 
particular fault the likelihood of failure has been 
enhanced or lessened. In a region in south central 
Japan, Pollitz and I found that during the period 
1901-1969, all earthquakes occurred where the fail- 
ure probability was enhanced by strain diffusion, 
mainly from the 1891 Nobi earthquake. No earth- 
quakes occurred where the fault orientation was 
such that the strain pulse increased fault clamping 
even though many of these faults have been simi- 
larly active historically. 

While the physics of strain diffusion is reasonably 
well understood, earthquake rupture at slow speeds 
is not. In particular the discovery by AJan Linde 
and me, that slow events can occur on the same 
faults that also fail rapidly at other times, is yet to 
be understood. It is obviously of considerable soci- 
etal relevance to understand what conditions cause 
the different behavior. One of the most dramatic 



CARNEGIE INSTITUTION 



page 122 I YEAR BOOK p8—pp 



situations occurs off northeast Japan. Here there 
are great subduction events, as large as magnitude 
8. However, most of the plate motion is released 
as slow, non-destructive events that, until recently, 
could not even be detected. The locked zone of 
these earthquakes is well to the east of Japan, so 
can best be studied using instruments on or below 
the seafloor. 

During the summer of 1999 a DTM team — 
Linde, Nelson McWhorter, Ben Pandit, Michael 
Acierno, and I — spent two months on the drill 
ship of the international Ocean Drilling Program, 
the JOIDES Resolution, about 120 km off the coast 
of Japan. Two holes, about 50 km apart, were 
drilled and instrumented with strainmeters, tilt- 
meters, and seismometers, in collaboration with a 
Japanese team led by former DTM predoctoral 
fellow Kiyoshi Suyehiro. One hole is about 15 km 
above an area of active seismicity, which illumi- 
nates the subduction interface. The other is in a 
similar position, but the interface is seismically 
quiet. Since the plate motion here is about 10 cm 
per year, there is a strong expectation that these 
data will soon provide new insight into the com- 
plex behavior of this important subduction zone. 

Observing Transient Deformation 

Paul G. Silver 

Transient deformation in the Earth's crust is one 
of the important sources of information about the 
processes that trigger seismic events. In collabora- 
tion with postdoctoral fellow Stephen Gao and 
Staff Members Alan Linde and Selwyn Sacks, I 
have been examining two very interesting tran- 
sients that may shed light on the earthquake-trig- 
gering process. 

As discussed at greater length above by Selwyn 
Sacks, it is not unusual to observe slow multiyear 
deformation following a large earthquake, as the 
crust slowly adjusts to the change in the stress field 
brought about by such an event. It is much more 
unusual to observe such slow deformation unrelat- 
ed to a large earthquake. We have observed one 
such event, and it produced an increase in the slip 
velocity along the San Andreas Fault that began in 



1993 and continues to the present. This transient 
was observed in the Parkfield region of central 
California — a site of an expected magnitude 6 
earthquake. This expectation is based on a past 
sequence of earthquakes that ruptured the same 
patch of the fault every 22 years on average. While 
the anticipated Parkfield earthquake has not yet 
occurred, the resulting concentration of many dif- 
ferent kinds of strain instrumentation has produced 
an unprecedented data set spanning 15 years of 
observations. The instrumentation used includes 
two-color electronic distance meters (EDMs), 
which are similar in precision to the better-known 
GPS receivers; creepmeters, which measure motion 
locally across the fault; borehole strainmeters, 
including those produced at DTM; and borehole 
seismometers for detecting microearthquake activity, 
which is a useful measure of strain in the seismo- 
genic zone beneath the surface. The integration of 
data from all these instruments reveals a fascinating 
deformation event. 

The most easily observable aspect of the transient, 
from the EDM and creep data, shows a speeding 
up of the San Andreas Fault slip from 1 cm/yr to 
1.3 cm/yr beginning in 1993. The increase in slip 
rate corresponds temporally to a dramatic increase 
in general seismic activity, including the occur- 
rence of four M ~ 4 earthquakes that occurred 
along a 6-km segment of the fault just northwest 
of the EDM network. There was also a synchro- 
nous change in borehole shear strain rate. Such a 
change in slip and strain rate requires that the con- 
ditions on the fault have changed: either the resis- 
tance to slip on the fault has been reduced, or the 
stress driving the fault slip has increased. 

Modeling of the EDM and borehole strain data 
provides a means for distinguishing between these 
two possibilities. Indeed, the data suggest that the 
stress has increased as a result of even larger slow 
aseismic slip to the north that loaded the southern 
segment. This larger event was probably triggered 
by the occurrence of the four seismic events. The 
existence of this northern slip transient is not 
directly visible from surface observations, but it has 
been inferred from careful analysis of the rate of 
microearthquake activity. Thus, the examination 
of these various sources of data reveals a complex 



I 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 123 



episode of transient deformation and stress redis- 
tribution. Such events have only occasionally been 
observed, and we presently know relatively little 
about them. They nevertheless represent a phe- 
nomenon that could significantly increase our 
understanding of the redistribution of stress and 
strain in the crust and its relation to the occurrence 
of earthquakes. 

Another intriguing transient involves the M w = 7.3 
Landers earthquake of June 28, 1992. Since the 
occurrence of this earthquake, there has been 
heightened interest in the topic of triggered seis- 
micity, because this event was followed by intense 
seismic activity for several weeks over a broad area 
encompassing much of the western United States. 
To see if there was a long-term effect, we examined 
all earthquakes, including the very smallest. We 
found that the short-term triggering was only the 
beginning of a previously unrecognized longer- 
term (five-year) trend, consisting of a persistently 







(a) 


200 - 








100- 




! 






n - 


1 1 i t 


-, — i — , — i — U i , — 1 — , — 1 — 1 — 


pwn) 



1988 1990 1992 1994 1996 

Time (Years) 




1988 1990 1992 1994 1996 



20 i 

15 

10 

5 





-5 -*-r 



error bar = 2 STD 



HHiii, 



(c) 



H 



l§H *-*-HliHH 



0.0 0.5 1.0 1.5 2.0 

Cut-off magnitudes 



2.5 



Fig. 1 3. A time series of seismicity rate (events/day) and ampli- 
tude of the annual cycle is shown here: (a) number of events 
per day; (b) monthly average of number of events per day (solid 
line), fit to a decaying sinusoid with an annual period (dotted 
line); (c) amplitude of the annual cycle (and uncertainty) calcu- 
lated using different cutoff magnitudes. The amplitude is signifi- 
cantly different from zero for events less than magnitude 1 .7. 



elevated, but decaying, microearthquake rate 
(Fig. 13). This finding suggests that the changes 
brought about by this earthquake were both wide- 
spread and semipermanent, essentially sensitizing a 
large area to small stress perturbations. 

Perhaps even more surprising, this seismicity excess 
was modulated by an annual cycle, in which there 
was a maximum of earthquakes in the fall and a 
minimum in the spring (Fig. 13). Much of this 
signal comes from volcanic/ hydrothermal areas 
(Fig. 14) where the short-term triggering was 
clearly observed. There are several possible envi- 
ronmental sources of stress that might give rise to 
this cycle, including tidal loading, precipitation, 
and barometric pressure. For a variety of reasons, 
barometric pressure appears to be the most plausi- 
ble of the three. Whichever is in fact the cause, it 
implies that very small environmental stresses of 
order tens of millibars are capable of triggering 
small seismic events. 



40' -a 




1000 



100 



•100 



■-J- -1000 



Fig. 1 4. This map shows the spatial distribution of the annual 
cycle (defined as the difference in the total number of events 
between the second half and the first half of the year) for the 
post-Landers period. Dark areas (at lat 39°, long -123°; lat 37° 
long - 1 19°; and lat 36°, long - 1 18°) show the largest annual 
cycle, with more events in the fall than in the spring. Dots 
denote events that occurred within 1 days after Landers and 
reflect regions of short-term triggering. Note that the annual 
cycle is seen where there was short-term triggering. 



CARNEGIE INSTITUTIO 



N 



Department of Terrestrial Magnetism Personnel 



page 124 YEAR BOOK p8~pp 



Research Staff Members 

L Thomas Aldrich, Emeritus 

Conel M. O'D. Alexander 

Alan P. Boss 

Louis Brown, Emeritus 

Richard W. Carlson 

John A. Graham 

Erik H. Hauri 

David E. James 

Alan T. Linde 

Vera C. Rubin 

I. Selwyn Sacks 

Francois Schweizer 

Steven B. Shirey 

Paul G. Silver 

Sean C. Solomon, Director 

Fouad Tera, Emeritus 

George W. Wethenll 

Senior Research Fellows 

Don L Anderson, Merle A. Tuve Senior Fellow 1 
Renzo Sancisi, Merle A. Tuve Senior Fellow 2 

Senior Associate 

Ian D. Mac Gregor, National Science Foundation 3 
Postdoctoral Fellows and Associates 

Richard D. Ash, Carnegie Fellow and NASA 

Associate'' 
Joakim Bebie, Carnegie Fellow and NSF Astrobiology 

Institute FelloW*- 5 
Laurie D. Benton, NSF Earth Sciences Research 

Fellow 6 
Kenneth M. Chick, Carnegie Fellow 
Matthew J. Fouch, Harry Oscar Wood Fellow* 1 
Andrew M. Freed, NSF Earth Sciences Research Fellow 
Stephen S. Gao, NSF Associate 8 
Monica R. Handler, Carnegie Fellow 9 
Emilie E. E. Hooft, NSF and NASA Associate 
Satoshi Inaba, Japan Society for the Promotion of 

Science Fellow 10 
Philip E. Janney, NSF Associate" 
Wenjie Jiao, Carnegie Fellow and NSF Associate* 
Daniel D. Kelson, Barbara McClintock Fellow 
Stephen J. Kortenkamp, NASA Associate 
John C. Lassiter, NSF Associate' 1 
Jie Li, Grove Karl Gilbert Fellow* 
Hong Liu, NSF Associate' 3 
Patrick J. McGovern, NASA Associate 
William G. Minarik, Carnegie Fellow and 

NSF Associate* '* 
Larry R. Nittler, Carnegie Fellow 1 ' J 
Aaron J. Pietruszka, Carnegie Fellow 11, 
Michael W. Regan, Hubble Fellow 
Paul B. Tomascak, Carnegie Fellow 17 
Harri A. T. Vanhala, NASA Associate 
Lianxing Wen, Carnegie Fellow 6 



Predoctoral Fellows and Associates 

Ana Lucia Novaes de Araujo, University of Brasilia 

Charles Kevin Boyce, Harvard University* 

Jaime Domi'nguez, Universidad Nacional Autonoma 

de Mexico 
Jane Gore, University of Zimbabwe 
Gordon J. Irvine, University of Durham 
Andrew H. Menzies, University of Cape Town 
Teresia K. Nguuri, University of the Witwatersrand 
Susan J. Webb, University of the Witwatersrand 

Research Interns 

Jacob Bauer, Spring Hill College 
Kirsten A. Brandt, Eartham College 
Caleb I. Fassett, Williams College 
Sarah E. Faulkner, Brown University 
Caprice L Gray, Massachusetts Institute of 

Technology 
Patrick L. Kelly, Sidwell Friends High School 
Kaisa E, Mueller, University of Missouri, Columbia 
Lan-Anh Ngoc Nguyen, University of North Carolina 
Matthew J. K. Runkle, Yale University 
Kisha I. Steele, Howard University 
Branson C Stephens, Oklahoma Baptist University 
Karina Zavala, Northern Arizona University 
Sarah B. Zimmerman, Saint Lawrence University 

Supporting Staff 

Michael J. Acierno, Computer Systems Manager 

John R. Almquist, Library Volunteer 

Maceo T. Bacote, Engineering Apprentice* 

Georg Bartels, Instrument Maker 

Richard L. Bartholomew, Machinist Instrument 

Maker" 3 
Mary McDermott Coder, Senior Administrator 
H. Michael Day, Facilities Manager* 
Roy R. Dingus, Building Engineer* 
Janice Scheherazade Dunlap, Secretary to the 

Director 
Pablo D. Esparza, Maintenance Technician* 
Rosa Maria Esparza, Administrative Assistant 
Shaun J, Hardy, Librarian* 
Mary Horan, Geochemistry Laboratory Manager 
Sandra A. Keiser, Scientific Computer Programmer 
William E. Key, Building Engineer* 
Adriana Kuehnel, Library Volunteer 
Randy A. Kuehnel, Geophysical Technician 
P. Nelson McWhorter, Sen/or Instrument Maker, 

Shop Manager 
Timothy D. Mock, Moss Spectrometry Laboratory 

Manager 
Ben K. Pandit, Electronics Engineer 
Lawrence B. Patrick, Maintenance Technician* 
Daniela D. Power, Geophysical Research Assistant 
Pedro J. Roa, Maintenance Technician* 
Roy E. Scalco, Building Engineer* 
Brian P. Schleigh, Electronics Technician 19 
Terry L. Stahl, Fiscal Officer 
Jianhua Wang, Ion Microprobe Research Specialist 
David Weinrib, Fiscal Assistant 10 
Mem Wolf, Library Technical Assistant* 



Adjunct Investigators 

Jay A. Brandes, University of Texas at Austin 
Stephen S. Gao, Kansas State University 
Catherine L. Johnson, Incorporated Research 

Institutions for Seismology 
Cecily J. Wolfe, National Science Foundation 

Visiting Investigators 

Craig R, Bina, Northwestern University 
Ingi Th. Bjarnason, University of Iceland 
Sherwood Chang, NASA Ames Research Center 
Ines L. Cifuentes, Carnegie Institution of Washington 
Timothy J. Clarke, New Mexico Institute of Mining 

and Technology 
Gregory A. Good, West Virginia University 
Jitendranath Goswami, Physical Research Laboratory, 

Ahmedabad, India 
Rosemary Hickey-Vargas, Florida International 

University 
Christopher R. Kincaid, University of Rhode Island 
John T. Lynch, National Science Foundation 
William G. Minarik, University of Maryland 
Harold J, Morowitz, George Mason University 
Julie D. Morris, Washington University, St. Louis 
Jeffrey J. Park, Yale University 
D. Graham Pearson, University of Durham 
Stephen H. Richardson, University of Cape Town 
Jeroen E. Ritsema, California Institute of Technology 
Stuart A. Rojstaczer, Duke University 
Raymond M. Russo, Jr., Northwestern University 
Paul A. Rydelek, University of Memphis 
Yuji Sano, Hiroshima University 
Martha K. Savage, Victoria University, New Zealand 
Patrick O. Seitzer, University of Michigan 
Yang Shen, University of Rhode Island 
David W. Simpson, Incorporated Research 

Institutions for Seismology 
j. Arthur Snoke, Virginia Polytechnic Institute and 
State University 

Douglas R. Toomey, University of Oregon 
Marian Tredoux, University of Cape Town 
Nathalie J. Valette-Silver, National Oceanographic 

and Atmospheric Administration 
John G VanDecar, Nature Magazine, England 
Dominique A. M. Weis, Free University of Brussels 
Elisabeth Widom, Miami University, Ohio 



'October and November 1998 

'April 1999 

3 FromJune2l, 1999 

'Joint appointment with the Geophysical Laboratory 

5 From March I, 1999 

'From July I, 1998 

'From January 15, 1999 

8 To August 3. 1998 

'From November 19, 1998 

'"FromApnl I, 1999 

'From October I, 1998 

"To December 3 1 . 1998 

"ToApnl30, 1999 

"To January 8, 1999 

'To October 3 1, 1998 

l6 From February 16, 1999 

'To September 30, 1998 

"From September 2 1, 1998 

"From September I, 1998 

"'Deceased September 14, 1998 



epartment of Terrestrial Magnetism Bibliography 






CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 12$ 



5587 Agustsson, K., A. T. Linde, R. Stefansson, 
and I. S. Sacks, Strain changes for the 1987 
Vatnafjoll earthquake in south Iceland and pos- 
sible magmatic triggering, J. Geophys. Res. 104, 
I 151-1 I6f, 1999. 

5632 Alexander, C. M. O'D., and L R. Nittler, 
The galactic evolution of Si, Ti, and O isotopic 
ratios, Astrophys.J. 5 I 9, 222-235, 1 999. 

5624 Becker, H, K. P. Jochum, and R W. 
Carlson, Constraints from high-pressure veins 
in eclogites on the composition of hydrous flu- 
ids in subduction zones, Chem. Geol. 160, 291- 
308, 1999. 

Becker, H„ K. P. jochum, and R W. 



Carlson, Trace element fractionation during 
dehydration of eclogites from high-pressure 
terranes and the implications for element fluxes 
in subduction zones, Chem. Geol., in press. 

5635 Bloom, J. R, S. C. Odewahn, S. G. 
Djorgovski, S. R. Kulkarni, F. A. Harrison, C 
Koresko, G. Neugebauer, L Armus, D. A. Frail, 
R. R. Gal, R. Sari, G. Squires, G. Illingworth, D. 
Kelson, F. H. Chaffee, R Goodrich, M. Feroci, E. 
Costa, L Piro, F. Frontera, S. Mao, C. Akerlof, 
and T. A. McKay, The host galaxy of GRB 
990 1 23, Astrophys. J. (Lett.) 5 I 8, L I -L4, 1 999. 
(No reprints available.) 

Bokelmann, G. H. R., and P. G. Silver, 



Mantle variations within the Canadian Shield: 
travel times from the APT89 portable broad- 
band transect,/ Geophys. Res., in press. 

56 1 9 Boss, A. P., Collapse and fragmentation 
of molecular cloud cores. VI. Slowly rotating 
magnetic clouds, Astrophys.J. 520, 744-750, 
1999. 

562 1 Boss, A. P., Planets elsewhere: more sur- 
prises, Modem Astronomer 3 (no. I), 59-60, 

1 999. (No reprints available.) 

5622 Boss, A. P., The birth of binary stars, Sky 
& Telescope 97 (no. 6), 32-38, 1999. (No 
reprints available.) 

Boss, A. P., Collapse and fragmentation 



of magnetic molecular cloud cores, in Star 
Formation 1 999, T Nakamoto, ed., Nobeyama 
Radio Observatory, Nobeyama, Japan, in press. 

Boss, A. P., Formation of extrasolar plan- 



ets: core accretion or disk instability?, Earth, 
Moon, and Planets, in press. 

Boss, A. P., C A. Beichman, and H. A. 

Thronson, NASA and the search for extrasolar 
planets, Earth, Moon, and Planets, in press. 

Boss, A. P., R Fisher, R I. Klein, and C F. 



McKee, The Jeans condition and collapsing 
cloud cores: filaments or binaries?, Astrophys. J., 
in press. 

Boss, A. P., and H. A. T. Vanhala, 



Triggering protostellar collapse, injection, and 
disk formation, Space Sci. Rev., in press. 

5625 Brandon, A. D., H. Becker, R W. 
Carlson, and S. B. Shirey, Isotopic constraints 
on time scales and mechanisms of slab material 
transport in the mantle wedge: evidence from 
the Simcoe mantle xenoliths, Washington, 
USA, Chem. Geol. 1 60, 387-407, 1 999. (No 
reprints available.) 



5610 Brown, L, "Richard Brooke Roberts," in 
American National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. 1 8, pp. 614-61 6, 
Oxford University Press, New York, 1 999. (No 
reprints available.) 

561 I Brown, L, Paths for flight: innovation and 
the origin of radar, in Innovation and the 
Development of Flight, R. D. Launius, ed., pp. 
1 88-206, Texas A&M Press, College Station, 
Texas, 1999. (No reprints available.) 

Brown, L, A Radar History of World War 



II: Technical and Military Imperatives, Institute of 
Physics, Bristol, UK, in press. 

Burkert, A., P. Bodenheimer, R. I. Klein, 



and A. P. Boss, Multiple fragmentation of pro- 
tostars, in Protostars and Planets IV, V. G. 
Mannings, A. P. Boss, and S. S. Russell, eds., 
University of Arizona Press, Tucson, in press. 

Carlson, R. W., and G. W. Lugmair, 



Timescales of planetesimal formation and dif- 
ferentiation based on extinct and extant 
radioisotopes, in Origin of the Earth and Moon, 
K. Righter and R. M. Canup, eds., University of 
Arizona Press/Lunar and Planetary Institute, in 
press. 

Carlson, R W., D. G. Pearson, F. R 



Boyd, S. B. Shirey, G. Irvine, A. H. Menzies, and 
J. J. Gurney, Re-Os systematics of lithospheric 
peridotites: implications for lithosphere forma- 
tion and preservation, in Proceedings of the 7th 
International Kimberlite Conference, in press. 

5588 Chambers, J. E., and G. W. Wetherill, 
Making the terrestrial planets: N-body integra- 
tions of planetary embryos in three dimensions, 
Icarus 136, 304-327, 1998. (No reprints avail- 
able.) 

5620 Constable, C. G., and C L Johnson, 
Anisotropic paleosecular variation models: 
implications for geomagnetic field observables, 
Phys. Earth Planet. Inter. I 15, 35-51, 1999. (No 
reprints available.) 

5582 de Blok, W. J. G., and S. S. McGaugh, 
Testing modified Newtonian dynamics with 
low surface brightness galaxies: rotation curve 
fits, Astrophys.J. 508, 132-140, 1998. 

5626 Farquhar, J., E. Hauri, and J. Wang, New 
insights into carbon fluid chemistry and graphite 
precipitation: SIMS analysis of granulite facies 
graphite from Ponmudi, South India, Earth 
Planet. Sci. Lett. 171, 607-62 1 , 1 999. 

Ferrarese, L, J. R Mould, R C. Kennicutt, 

Jr., J. P. Huchra, H. C Ford, W. L Freedman, P. 
B. Stetson, B. F. Madore, S. Sakai, B. K. Gibson, 
J. A. Graham, S. M. Hughes, G. D. Illingworth, 
D. D. Kelson, L Macn, K. Sebo, and N. A. 
Silbermann, The HST key project on the extra- 
galactic distance scale. XXVI. The calibration of 
population II secondary distance indicators and 
the value of the Hubble constant, Astrophys.J., 
in press. 

Gao, S., P. G. Silver, and A. T Linde, A 

systematic analysis of deformation data at 
Parkfield, California: detection of a long-term 
strain transient,/ Geophys. Res., in press. 

5597 Gibson, B. K, S. M. G. Hughes, P. B. 
Stetson, W. L Freedman, R. C. Kennicutt, jr., J. 
R. Mould, F. Bresolin, L, Ferrarese, H. C, Ford, J. 
A. Graham, M. Han, P. Harding, J. G. Hoessel, J. 



P. Huchra, G. D. Illingworth, D. D. Kelson, L M. 
Macn, B. F. Madore, R L Phelps, C F. Prosser, 
A. Saha, S. Sakai, K M. Sebo, N. A. Silbermann, 
and A. M. Turner, The Hubble Space Telescope 
key project on the extragalactic distance scale. 
XVII. The Cepheid distance to NGC 4725, 
Astrophys.J. 512, 48-64, 1999. (No repnnts 
available.) 

Gibson, B. K„ P. B. Stetson, W. L. 



Freedman, J. R. Mould, R. C. Kennicutt, Jr., J. P. 
Huchra, S. Sakai, G. A. Graham, C I. Fassett, D. 
D. Kelson, L Ferrarese, S. M. G. Hughes, G. D. 
Illingworth, L. M. Macn, B. F. Madore, K. M. 
Sebo, and N. A. Silbermann, The HST key pro- 
ject on the extragalactic distance scale. XXV A 
recalibration of Cepheid distances to type la 
supernovae and the value of the Hubble con- 
stant, Astrophys.J., in press. 

5638 Good, G. A., "Louis A. Bauer," in 
American National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. 2, pp. 349-35 I , Oxford 
University Press, New York, 1 999. (No reprints 

available.) 

5639 Good, G. A., "Sydney Chapman," in 
American National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. 4, pp. 715-71 7, Oxford 
University Press, New York, 1 999. (No reprints 
available.) 

5640 Good, G. A., "John A. Fleming," in 
American National Biography, J. A. Garraty and 
M. C, Carnes, eds., vol. 8, pp. 1 02- 1 04, Oxford 
University Press, New York, 1 999. (No reprints 
available.) 

5641 Good, G. A., "Scott E. Forbush," in 
Amencan National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. 8, pp. 213-21 5, Oxford 
University Press, New York, 1 999. (No reprints 
available.) 

5642 Good, G. A., "Ernest Harry Vestine," in 
/American National Biography, J. A. Garraty and 
M. C Carnes, eds., vol. 22, pp. 343-344, 
Oxford University Press, New York, 1 999. (No 
reprints available.) 

Goswami, J. N., and H. A. T Vanhala, 



Short-lived nuclides in the early solar system: 
meteoritic evidence and plausible sources, in 
Protostars and Planets IV, V. G. Mannings, A. P. 
Boss, and S. S. Russell, eds., University of 
Arizona Press, Tucson, in press. 

5609 Graham, J. A., L. Ferrarese, W. L 
Freedman, R C Kennicutt, Jr., J. R Mould, A. 
Saha, P. B. Stetson, B. F. Madore, F. Bresolin, H. 
G Ford, B. K Gibson, M. Han, j. G. Hoessel, J. 
Huchra, S. M. Hughes, G. D. Illingworth, D. D. 
Kelson, L Macn, R Phelps, S. Sakai, N. A. 
Silbermann, and A. Turner, The Hubble Space 
Telescope key project on the extragalactic dis- 
tance scale. XX. The discovery of Cepheids in 
the Virgo Cluster galaxy NGC 4548, Astrophys. 
J. 5 1 6, 626-646, 1999. 

Grossman, J. N„ C, M. OD. Alexander, J, 

Wang, and A. J. Brearley, Bleached chondrules: 
evidence for widespread aqueous alteration 
processes on the parent asteroids of ordinary 
chondntes, Meteontics Planet. So., in press. 

Hauri, E. H., D. G. Pearson, D. G. 



Bulanova, and H. J. Milledge, Microscale varia- 
tions in C and N isotopes within mantle dia- 
monds revealed by SIMS, in Proceedings of the 
7th International Kimberlite Conference, in press. 



CARNEGIE INSTITUTION 



page I26\ YEAR BOOK p8~pp 



■ 



nough November 3, 1999. The list is regularly updated on the DTM Web site 

i/DTM,html), Ri prints of the numbered publications listed below can be obtained, except wr 
Department of Terrestrial Magnetism. 524 I Broad Branch Ro.id. N.W., Washmgto 
(E-mail: librai") i | When ordering, please give reprint number(s). 



Hooft, E. E. E., R. S. Detrick, D. R. 



Toomey, J. A. Collins, and J. Lin, Crustal and 
upper mantle structure along three contrasting 
spreading segments of the Mid-Atlantic Ridge, 
33.5-35°N,J. Geophys. Res., in press. 

5608 Hoppe, K. A., P. L Koch, R. W. Carlson, 
and S. D. Webb, Tracking mammoths and 
mastodons: reconstruction of migratory behav- 
ior using strontium isotope ratios, Geology 27, 
439-442, 1999. 

5603 Ishikawa, T., and F. Tera, Two isotopical- 
ly distinct fluid components involved in the 
Mariana arc: evidence from Nb/B ratios and B, 
Sr, Nd, and Pb isotope systematics, Geology 27, 
83-86, 1999. 

5630 James, D. E., and I. S. Sacks, Cenozoic 
formation of the central Andes: a geophysical 
perspective, in Geology and Ore Deposits of the 
Gentral Andes, B.J. Skinner, ed., pp. 1-25, 
Special Publication No. 7, Society of Economic 
Geologists, Littleton, Colorado, 1999. 

5605 Kelson, D. D., G. D. Illingworth, A. Saha, 
J. A. Graham, P. B. Stetson, W. L Freedman, R. 
C Kennicutt, J. R. Mould, L Ferrarese, J. P. 
Huchra, B. F. Madore, C F. Prosser, F. Bresolin, 
H. C Ford, B. K. Gibson, J. G. Hoessel, S. M. G. 
Hughes, L M. Macri, S. Sakai, and N. A. 
Silbermann, The Hubble Space Telescope key 
project on the extragalactic distance scale. XIX. 
The discovery of Cepheids in and a new dis- 
tance to NGC 3 1 98, Astrophys. J. 5 1 4, 6 1 4-636, 
1999. 

Kelson, D. D., G. D. Illingworth, J. L 

Tonry, W. L Freedman, R. C. Kennicutt, Jr., j. R. 
Mould, J. A. Graham, J. P. Huchra, L M. Macri, 
B. F. Madore, L Ferrarese, B. K Gibson, S. 
Sakai, P. B. Stetson, E. A. Ajhar, J. P. Blakeslee, 
A. Dressier, H. C Ford, S. M. G. Hughes, K. M. 
Sebo, and N. A. Silbermann, The extragalactic 
distance scale key project. XXVII. A denvation 
of the Hubble constant using the fundamental 
plane and D n .<r relations in Leo I, Virgo, and 
Fornax, Astrophys. J., in press. 

Kelson, D. D., G. D. Illingworth, P. G. van 

Dokkum, and M. Franx, The evolution of early- 
type galaxies in distant clusters. II. Internal kine- 
matics of 55 galaxies in the z=0.33 cluster 
CL 1 358+62, Astrophys. J., in press. 

Kelson, D. D., G. D. Illingworth, P. G. van 

Dokkum, and M. Franx, The evolution of early- 
type galaxies in distant clusters. III. M/L v ratios 
in the z=0.33 cluster CL I 358+62, Astrophys. ]., 
in press. 

5592 Kortenkamp, S„ Amid the swirl of inter- 
planetary dust, Mercury 27 (no. 6), 7- 1 1 , 1 998. 
(No reprints available.) 

Kortenkamp, S. J., E. Kokubo, and S. J. 



Weidenschillmg, Formation of planetary 
embryos, in Origin of the Earth and Moon, R. 
Canup and K. Righter, eds., University of 
Arizona Press/Lunar and Planetary Institute, in 
press. 

Kortenkamp, S. J„ and G. W. Wetherill, 



Terrestrial planet and asteroid formation in the 
presence of giant planets. I. Relative velocities 
of planetesimals subject to Jupiter and Saturn 
perturbations, Icarus, in press. 



5634 Kulkarni, S. R„ S. G. Djorgovski, S. C. 
Odewahn, J. S. Bloom, R. R. Gal, C, D. Koresko, 
F. A. Harrison, L M. Lubin, L Armus, R. Sari, G. 
D. Illingworth, D. D. Kelson, D. K Magee, P. G. 
van Dokkum, D. A. Frail, J. S. Mulchaey, M. A. 
Malkan, I. S. McClean, H. I. Teplitz, D. Koerner, 
D. Kirkpatrick, N. Kobayashi, I. -A. Yadigaroglu, J. 
Halpern, T. Piran, R. W. Goodrich, F. H. 
Chaffee, M. Feroci, and E. Costa, The afterglow, 
redshift, and extreme energetics of the -y-ray 
burst of 23 January 1999, Nature 398, 389-394, 
1999. (No reprints available.) 

5590 Lassiter, J. C, and E. H. Hauri, Osmium- 
isotope variations in Hawaiian lavas: evidence 
for recycled oceanic lithosphere in the 
Hawaiian plume, Earth Planet. Sci. Lett. 164, 
483-496, 1998. 

56 1 6 Macri, L M., J. P. Huchra, P. B. Stetson, 
N. A. Silbermann, W. L Freedman, R. C 
Kennicutt, J. R. Mould, B. F. Madore, F. Bresolin, 
L Ferrarese, H. C Ford, J. A. Graham, B. K 
Gibson, M. Han, P. Harding, R. J. Hill, J. G. 
Hoessel, S. M. G. Hughes, D. D. Kelson, G. D. 
Illingworth, R. |_ Phelps, C. F. Prosser, D. M. 
Rawson, A. Saha, S. Sakai, and A. Turner, The 
extragalactic distance scale key project. XVIII. 
The discovery of Cepheids and a new distance 
to NGC 4535 using the Hubble Space 
Telescope, Astrophys. J. 521, 1 55- 1 78, 1 999. (No 
reprints available.) 

5606 Madore, B. F., W. L Freedman, N. 
Silbermann, P. Harding, J. Huchra, J. R. Mould, j. 
A. Graham, L Ferrarese, B. K. Gibson, M. Han, 
J. G. Hoessel, S. M. Hughes, G. D. Illingworth, R. 
Phelps, S. Sakai, and P. Stetson, The Hubble 
Space Telescope key project on the extragalac- 
tic distance scale. XV. A Cepheid distance to 
the Fornax Cluster and its implications, 
Astrophys.]. 515, 29-41, 1999. (No reprints 
available.) 

Madore, B. F., W. L Freedman, N. 



Silbermann, P. Harding, J. R. Mould, J. Huchra, J. 
A. Graham, L Ferrarese, B. K Gibson, M. Han, 
J. G. Hoessel, S. M. Hughes, G. D. Illingworth, R. 
Phelps, S. Sakai, and P. Stetson, The HST key 
project, on the extragalactic distance scale. XV 
Implications of a Cepheid distance to the 
Fornax cluster, Astrophys. J., in press. 

Mannings, V G., A. P. Boss, and S. S. 



Russell, eds., Protostars and Planets IV, University 
of Arizona Press, Tucson, in press. 

Menzies, A. H., R. W. Carlson, S. B. 

Shirey, and J. J. Gurney, Re-Os systematics of 
Newlands peridotites: implications for diamond 
and lithosphere formation, in Proceedings of the 
7th International Kimberlite Conference, in press. 

558 1 Minarik, W. G., Complications for car- 
bonate melt mobility due to the presence of an 
immiscible silicate melt,/ Petrol. 39, 1965-1973, 
1998. (No reprints available.) 

Mould, J. R., J. P. Huchra, W. L 

Freedman, R. C Kennicutt, Jr., L. Ferrarese, H. 
C, Ford, B. K. Gibson, J. A. Graham, S. M. G. 
Hughes, G. D. Illingworth, D. D. Kelson, L M. 
Macri, B. F. Madore, S. Sakai, K. Sebo, N. A. 
Silbermann, and P. B. Stetson, The HST key 
project on the extragalactic distance scale. 
XXVIII. Combining the constraints on the 
Hubble constant, Astrophys. J., in press. 



5589 Mukasa, S. B., A. H. Wilson, and R. W. 
Carlson, A multielement geochronologic study 
of the Great Dyke, Zimbabwe: significance of 
the robust and reset ages, Earth Planet. Sci. Lett. 
1 64, 353-369, 1998. 

Nittler, L R., and C M. O'D. Alexander, 



Can stellar dynamics explain the metallicity dis- 
tributions of presolar grains?, Astrophys. J., in 
press. 

Pearson, D. G., and S. B. Shirey, Isotopic 

dating of diamonds, in Application of Radiogenic 
Isotopes to Ore Deposit Research and 
Exploration, Short Course Reviews in Economic 
Geology, Society of Economic Geologists, 
Littleton, Colorado, in press. 

56 1 2 Pearson, D. G„ S. B. Shirey, G. P. 
Bulanova, R. W. Carlson, and H. J. Milledge, Re- 
Os isotope measurements of single sulfide 
inclusions in a Siberian diamond and its nitro- 
gen aggregation systematics, Geochim. 
Cosmochim. Acta 63, 703-7 11,1 999. 

Pearson, D. C, S. B. Shirey, G. P. 

Bulanova, R. W. Carlson, and H. J. Milledge, 
Dating and paragenetic distinction of diamonds 
using the Re-Os isotope system: application to 
some Siberian diamonds, in Proceedings of the 
7th International Kimberlite Conference, in press. 

Polet, J„ P. G. Silver, S. Ruppert, S. Beck, 

T. Wallace, G. Zandt, R. Kind, A. Rudloff, and 
G. Asch, Shear wave anisotropy beneath the 
Andes from the BANJO, SEDA, and PISCO 
experiments,/ Geophys. Res., in press. 

5645 Prosser, C F., R. C Kennicutt, Jr., F. 
Bresolin, A. Saha, S. Sakai, W. L Freedman, J. R. 
Mould, L Ferrarese, H. C Ford, B. K Gibson, J. 
A. Graham, J. G. Hoessel, J. P. Huchra, S. M. 
Hughes, G. D. Illingworth, D. D. Kelson, L 
Macri, B. F. Madore, N. A. Silbermann, and P. B. 
Stetson, The Hubble Space Telescope key pro- 
ject on the extragalactic distance scale. XXII. 
The discovery of Cepheids in NGC 1 326A, 
Astrophys.]. 525, 80-104, 1999. (No reprints 
available.) 

563 I Regan, M. W., and J. S. Mulchaey, Using 
Hubble Space Telescope imaging of nuclear dust 
morphology to rule out bars fueling Seyfert 
nuclei, Astron. ]. II 7, 2676-2694, 1999. 

Regan, M. W., K. Sheth, and S. N. Vogel, 



Molecular gas kinematics in barred spiral galax- 
ies, Astrophys.]., in press. 

Richardson, W. P., E. A. Okal, and S. van 



der Lee, Rayleigh-wave tomography of the 
Ontong-Java Plateau, Phys. Earth Planet. Inter., in 
press. 

5602 Rubin, V C, Recollections after fifty 
years: Haverford AAS meeting, December 
1 950, in The American Astronomical Society's 
First Century, D. H. DeVorkin, ed., pp. 90-93, 
American Astronomical Society, Washington, 
DC, 1 999. (No reprints available.) 

5628 Rubin, V C, The trials and triumphs of 
American women in science, AWIS Magazine 
(Association for Women in Science) 28 (no. 2), 
34-36, 1999. (No reprints available.) 

Rubin, V C, Cecilia Payne-Gaposchkin, 



in Contribution of Women to Twentieth Century 
Physics, N, Byers, ed., IOP, London, in press. 



Department of Terrestrial Magnetism Bibliography 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 12/ 



Rubin, V. C, Comment on "A correla- 
tion between the spectroscopic and dynamical 
characteristics of the late F- and early G-type 
stars," Astrophys.J., in press. 

56 1 7 Rubin, V. C, A. H. Waterman, and J. D. 
P. Kenney, Kinematic disturbances in optical 
rotation curves among 89 Virgo disk galaxies, 
Astron.J. II 8, 236-260, 1999. 

5586 Rumpker, G., and P. G Silver, Apparent 
shear-wave splitting parameters in the pres- 
ence of vertically varying anisotropy, Geophys.J. 
Int. 1 35, 790-800, 1998. 

Rushmer, T„ W. G Minarik, and G I. 



Taylor, Physical processes of core formation, in 
Origin of the Earth and Moon, K. Righter and R. 
M. Canup, eds., University of Arizona 
Press/Lunar and Planetary Institute, in press. 

56 1 3 Rydelek, P. A., and I. S. Sacks, Large 
earthquake occurrence affected by small stress 
changes, Bull. Seismol. Soc. Am. 89, 822-828, 
1999. 

5627 Saal, A., S. R. Hart, N. Shimizu, E. H. 
Hauri, and G D. Layne, Pb isotopic variability in 
melt inclusions from oceanic island basalts, 
Polynesia, Science 282, 1481-1484, 1998. 

5643 Sakai, S„ L Ferrarese, R. C Kennicutt, J. 
A. Graham, N. A. Silbermann, j. R. Mould, W. 
L Freedman, F. Bresolin, H. C. Ford, B. K. 
Gibson, M. Han, P. Harding, J. G Hoessel, J. P. 
Huchra, S. M. Hughes, G. D. Illingworth, D. 
Kelson, L Macri, B. F. Madore, R. L, Phelps, A. 
Saha, K. M. Sebo, P. B. Stetson, and A. Turner, 
The Hubble Space Telescope extragalactic dis- 
tance scale key project. XXIII. The discovery of 
Cepheids in NGC 33 19, Astrophys.J. 523, 540- 
558, 1999. (No reprints available.) 

Sakai, S., J. R. Mould, S. M. G Hughes, J. 

P. Huchra, L. M. Macri, R. C. Kennicutt, B. K. 
Gibson, L Ferrarese, W. L Freedman, M. Han, 
H. G Ford, J. A. Graham, G D. Illingworth, D. 
D. Kelson, B. F. Madore, K. Sebo, N. A. 
Silbermann, and P. B. Stetson, The Hubble 
Space Telescope key project on the extragalac- 
tic distance scale. XXIV. The calibration of 
Tully-Fisher relations and the value of the 
Hubble constant, Astrophys.J., in press. 

5623 Schweizer, F., Overview: low-z observa- 
tions of interacting and merging galaxies, in 
Galaxy Interactions at Low and High Redshift, J. E. 
Barnes and D. B. Sanders, eds., pp. I -10, 
International Astronomical Union Symposium 
186, Kluwer, Dordrecht, 1999. 

Schweizer, F., Effects of late mergers on 

stellar populations in E and SO galaxies, 
Astrophys. Space So'., in press. 

Schweizer, F., Young globular clusters, in 

Spectrophotometnc Dating of Stars and Galaxies, 
I. Hubeny, S. Heap, and R. Cornett, eds., 
Astronomical Society of the Pacific, San 
Francisco, in press. 

5604 Silbermann, N. A., P. Harding, L 
Ferrarese, P. B. Stetson, B. F. Madore, R. C. 
Kennicutt, Jr., W. L Freedman, J. R Mould, F. 
Bresolin, H. Ford, B. K Gibson, J. A. Graham, M. 
Han, J. G Hoessel, R. J. Hill, J. Huchra, S. M. G 
Hughes, G D. Illingworth, D. Kelson, L Macri, 
R. Phelps, D. Rawson, S. Sakai, and A. Turner, 



The Hubble Space Telescope key project on the 
extragalactic distance scale. XIV The Cepheids 
in NGC I 365, Astrophys.J. 515, 1-28, 1999. 
(No reprints available.) 

5629 Silver, P. G, Y. Bock, D. C Agnew, T 
Henyey, A. T. Linde, T. V. McEvilly, J.-B. Minster, 
B. A. Romanowicz, I. S. Sacks, R. B. Smith, S. C 
Solomon, and S. A. Stein, A plate boundary 
observatory, IRIS Newsletter lb (no. 2), 3-9, 
1 998. (No reprints available.) 

5644 Silver, P. G, D. Mainprice, W. B Ismail, 
A. Tommasi, and G Barruol, Mantle structural 
geology from seismic anisotropy, in Mantle 
Petrology: Field Observations and High Pressure 
Experimentation: A Tribute to Francis R. (Joe) 
Boyd, Y Fei, C M. Bertka, and B. O. Mysen, 
eds., pp. 79-103, Special Publication No. 6, 
Geochemical Society, Houston, Texas, 1 999. 

5615 Smith, D. E., M. T Zuber, S. C Solomon, 
R. j. Phillips, J. W. Head, J. B. Garvin, W. B. 
Banerdt, D. O. Muhleman, G. H. Pettengill, G 
A. Neumann, F. G Lemoine, J. B. Abshire, O. 
Aharonson, C. D. Brown, S. A. Hauck, A. B. 
Ivanov, P. J. McGovern, H. J. Zwally, and T C. 
Duxbury, The global topography of Mars and 
implications for surface evolution, Science 284, 
1495-1503, 1999. 

5633 Solomon, S. C, M. A. Bullock, and D. H. 
Grinspoon, Climate change as a regulator of 
tectonics on Venus, Science 286, 87-90, 1999. 

5595 Stacey, F. D., Equations-of-state for 
close-packed materials at high pressures: geo- 
physical evidence,/ Phys.: Gondens. Matter I I , 
575-582, 1999. 

5594 Stecher, O., R. W. Carlson, and B. 
Gunnarsson, Torfajokull: a radiogenic end- 
member of the Iceland Pb-isotopic array, Earth 
Planet. Sa. Lett 165, I 1 7- 1 27, 1 999. 

5584 Stetson, P. B., A. Saha, L Ferrarese, D. M. 
Rawson, H. C. Ford, W. L Freedman, B. K. 
Gibson, J. A. Graham, P. Harding, M. Han, R. J. 
Hill, J. G. Hoessel, J. P. Huchra, S. M. G Hughes, 
G D. Illingworth, D. D. Kelson, R. C Kennicutt, 
Jr., B. F. Madore, J. R Mould, R L Phelps, S. 
Sakai, N. A. Silbermann, and A. Turner, The 
extragalactic distance scale key project. XVI. 
Cepheid variables in an inner field of M 1 1 , 
Astrophys.J. 508, 49 I -5 1 7, 1 998. (No reprints 
available.) 

56 1 8 Tera, F„ and R W. Carlson, Assessment 
of the Pb-Pb and U-Pb chronometry of the 
early solar system, Geochim. Gosmochim. Acta 
63, 1877-1889, 1999. 

5607 Tomascak, P. B„ R. W. Carlson, and S. B. 
Shirey, Accurate and precise determination of 
Li isotopic compositions by multi-collector sec- 
tor ICP-MS, Ghem. Geol. 158, 145-154, 1999. 

56 1 4 Tomascak, P. B., F. Tera, R. T. Helz, and 
R. J. Walker, The absence of lithium isotope 
fractionation during basalt differentiation: new 
measurements by multicollector sector ICP-MS, 
Geochim. Gosmochim. Acta 63, 907-9 1 0, 1 999. 

5637 Tran, K. H, D. D. Kelson, P. G van 
Dokkum, M. Franx, G D. Illingworth, and D. 
Magee, The velocity dispersion of MS 1054-03: 
a massive galaxy cluster at high redshift, 
Astrophys.J. 522, 39-45, 1999. (No reprints 
available.) 



5636 van Dokkum, P. G, M. Franx, D. 
Fabricant, D. D. Kelson, and G D. Illingworth, A 
high merger fraction in the rich cluster MS 
1 054-03 at z = 0.83: direct evidence for hier- 
archical formation of massive galaxies, 
Astrophys. J. (Lett.) 520, L95-L98, 1999. (No 
reprints available.) 

5598 van Geen, A., N. J. Valette-Silver, S. N. 
Luoma, C, C Fuller, M. Baskaran, F. Tera, and J. 
Klein, Constraints on the sedimentation history 
of San Francisco Bay from l4 C and l0 Be, Mar. 
Ghem. 64, 29-38, 1999. (No reprints available.) 

VanDecar, J. C, R. M. Russo, D. E. James, 

W. B. Ambeh, and M. Franke, Aseismic contin- 
uation of the Lesser Antilles slab beneath conti- 
nental South America,/ Geophys. Res., in press. 

5601 Vanhala, H. A. T., The triggered origin of 
the solar system, Proc. Indian Acad. Sci. (Earth 
Planet. Sa.) 107, 391-400, 1998. 

5583 Vanhala, H. A. T, and A. G. W. 
Cameron, Numerical simulations of triggered 
star formation. I. Collapse of dense molecular 
cloud cores, Astrophys.J. 508, 29 I -307, 1 998. 

Wethenll, G W., Planetary accumulation 



with a continuous supply of planetesimals, in 
Dust to Terrestrial Planets, R. Kallenbach, ed., 
Kluwer, in press. 

Whitmore, B. G, Q. Zhang, C. Leitherer, 

S. M. Fall, F. Schweizer, and B. W. Miller, The 
luminosity function of young star clusters in 
"The Antennae" galaxies (NGC 4038/4039), 
Astron.J., in press. 

5596 Widom, E„ K A. Hoernle, S. B. Shirey, 
and H.-U. Schmincke, Os isotope systematics in 
the Canary Islands and Madeira: lithospheric 
contamination and mantle plume signatures,/ 
Petrol. 40, 279-296, 1999. (No reprints avail- 
able.) 

5585 Wolfe, C J., Prospecting for hotspot 
roots, Nature 396, 212-213, 1998. 

5599 Wolfe, G J., Number of women faculty 
in the geosciences increasing, but slowly, Eos, 
Trans. Am. Geophys. Union 80 (no. 12), I 33 and 
136, 1999. 

5600 Wolfe, C J., F. L Vernon, III, and A. Al- 
Amri, Shear-wave splitting across western 
Saudi Arabia: the pattern of upper mantle 
anisotropy at a Proterozoic shield, Geophys. 
Res. Lett. 26,779-782, 1999. 

559 I Zuber, M. T, D. E. Smith, R. J. Phillips, S. 
C. Solomon, W. B. Banerdt, G A. Neumann, 
and O. Aharonson, Shape of the northern 
hemisphere of Mars from the Mars Orbiter 
Laser Altimeter (MOLA), Geophys. Res. Lett. 
25,4393-4396, 1998. 

5593 Zuber, M. T, D. E. Smith, S. C Solomon, 
J. B. Abshire, R S. Afzal, O. Aharonson, K 
Fishbaugh, P. G. Ford, H. V Frey, J. B. Garvin, J. 
W. Head, A. B. Ivanov, C L Johnson, D. O. 
Muhleman, G A. Neumann, G H. Pettengill, R. 
J. Phillips, X. Sun, H. J. Zwally, W. B. Banerdt, 
and T, C, Duxbury, Observations of the north 
polar region of Mars from the Mars Orbiter 
Laser Altimeter, Science 282, 2053-2060, 1998. 



CARNEGIE INSTITUTION 



page 128 YEAR BOOK p8~pp 



Extradepartmental and Administrative 



Carnegie Administrative Personnel 

Lloyd Allen, Building Maintenance Specialist 

Sharon Bassin, Secretory to the President 

Sherrill Berger, Research Assistant External Affairs 

Gloria Bnenza, Budget and Management Analysis Manager 

Don A. Brooks, Building Maintenance Specialist 

Cady Canapp, Human Resources and Insurance Manager 

Ellen Carpenter, Assistant Editor' 

Margaret Charles, Secretary 

Michael Charles, Systems Assistant 2 

Patricia Craig, Editor and Publications Officer 3 

Karin Dasuki, Financial Accountant 

Sonja DeCarlo, Grants and Operations Manager 

Susanne Garvey, Director of External Affairs 

Ulysses Glover, Moving Assistant 4 

Claire Hardy, Data Processor 5 

Margaret Hazen, Staff Director — Centennial Committee 6 

Susan Humphreys, Administrative Secretary 

Ann Keyes, Payroll Coordinator 

Charles Kim, Systems Administrator 7 

John Lively, Director of Administration and Finance 

Tina McDowell, Editor and Publications Officer 3 

Trong Nguyen, Financial Accountant 

Catherine Piez, Endowment Manager" 

Arnold Pryor, Facilities and Services Supervisor 

Michelle Robinson, Housekeeper 

Maxine F. Singer, President 

John Strom, Facilities Coordinator 

Kris Sundback, Financial Manager 

Vickie Tucker, Administrative Coordinator/ Accounts Payable 

Susan Vasquez, Assistant to the President 

Yulonda White, Human Resources and Insurance Records Coordinator 

Catherine Whittenburg, Assistant Editor 10 

Jacqueline Williams, Assistant to Manager/Human Resources and Insurance 



From October 1 5, 1 998 

1 To January 3 1 , 1999 
- To January 29, 1 999 
' To June 15, 1999 
5 From October 2. 1998 



<■ From July 20, 1998 
' From January 4, 1 999 
e From February 1 , 1999 
'To April 30, 1999 
10 To September 25, 1 99i 



Carnegie Academy for Science Education 

Kim Abies, Mentor Teacher 2 

Dayo Akinsheye, Mentor Teacher 2 

Jamie Antonisse, CASE Intern 2 

Michael Charles, CASE Intern' 

Ines Cifuentes, CASE Director 

Namaal DeSilva, CASE Intern 2 

Carolyn Dickey, Mentor Teacher' 

Sandra Dobson, Mentor Teacher 2 

Asonja Dorsey, Mentor Teacher 2 

Julie Edmonds, Consultant 2 

Daniel Feinberg, Mentor Teacher 2 

Linda Feinberg, CASE Administrator and Editor 

Alida Fenner, Mentor Teacher'- 2 

Kim Fndie, Mentor Teacher' 

Maritsa George, Mentor Teacher'- 2 

Jacqueline Goodloe, Mentor Teacher'- 2 

Charles James, CASE and First Light Director 

Sharon Musa, Mentor Teacher 2 

Thomas Nassif, Mentor Teacher 2 

Sandra Norried, Mentor Teacher' 

Daniel Robison, Mentor Teacher 2 

Amy Seitz, CASE Intern 2 

Jennifer Seligmann, CASE Intern'- 2 

Gregory Taylor, Mentor Teacher'- 2 

Jerome Thornton, Mentor Teacher' 

Kalin Tobler, Mentor Teacher' 

Derric Turner, CASE Intern 2 

Nirav Vakharia, Mentor Teacher 2 

Sue P. White, Mathematics Coordinator', Mathematics Institute Director 2 

Laurie Young, Mentor Teacher' 2 



Summer Institute, 1998 
: Summer Institute, 1 999 




Extradepartmental and Administrative 



:arnegie institution 



YEAR BOOK p8~pp page I2p 




On May 5, 1 999, Carnegie President Maxine Singer was recog- 
nized for her lifetime of achievements. M.R.C. Greenwood, 
Chancellor of the University of California, Santa Cruz, presented 
Dr. Singer with the prestigious Vannevar Bush Award from the 
National Science Board of the National Science Foundation. The 
award is the highest honor bestowed by the board and Dr. Singer 
is the first woman ever to receive it. 



Publications of the President 

Berg, P., and M. F. Singer, Inspired choices, Science 282, 873, 1998. 

Berg, P., and M. F. Singer, Regulating human cloning, Science 282, 
413, 1998. 

Singer, M. F., Believing Is Not Understanding, Washington Post, 
OpEd page, August I 8, 1 999. 



The Capital Science Lectures are spon- 
sored by the institution with substantial 
support from Baxter International Inc., the 
Bell Atlantic Foundation, Human 
Genome Sciences, Inc., and the Johnson 6c 
Johnson Family of Companies. The lec- 
tures — free and open to the public — are 
held in the Root Auditorium at Carnegie's 
headquarters at 16th and P Streets in 
northwest Washington, D. C. Speakers 
also meet informally with groups of high 
school students. During the 1998-1999 
year, the following lectures were given: 




CAPITAL SCIENCE LECTURES 




Prion Biology and Diseases, by Stanley B. Prusiner (Department of Neurology, University of 
California, San Francisco), October 13, 1998 

Return to the Center of the Universe: Our Search for Place and Purpose, by Alan Dressier (The 
Observatories of the Carnegie Institution of Washington), November 17, 1998 

The Early Evolution of Animals, by Andrew H. Knoll (Department of Organismic and Evolutionary 
Biology, Harvard University), December 15, 1998 

Planetary Perspectives on Life in the Solar System, by Christopher F. Chyba (The SETI Institute 
and Department of Geological and Environmental Studies, Stanford University), January 26, 1999 

Volcanic Eruptions: Watching the Magma Rise from Depth, by Alan Linde (Department of Terrestrial 
Magnetism, Carnegie Institution of Washington), February 23, 1999 

Too Much of a Good Thing? Fertilizer and Global Change in the Nitrogen Cycle, by Pamela A. 
Matson (Department of Geological and Environmental Sciences and the Institute of International 
Studies, Stanford University), March 23, 1999 

Cancer Development and Cell Immortality , by Robert A. Weinberg (Whitehead Institute for 
Biomedical Research, Massachusetts Institute of Technology), April 20, 1999 

Phytochemicals: Plant Sex, Human Drugs, and Insect Rock and Roll, by May Berenbaum 
(Department of Entomology, University of Illinois at Urbana-Champaign), May 18, 1999 



CARNEGIE INSTITUTIO 



N 



page 130 I YEAR BOOK p8~pp 



inancial Statements 



Financial Profile 



r's Note: Reader's Note: In this section, any discussion of 
spending levels or endowment amounts are on a cash or cash-equivalent 
basis. Therefore, the funding amounts presented do not reflect the impact 
of capitalization, depreciation, or other non-cash amounts. 

The primary source of support for Carnegie 
Institution of Washington's activities is its endow- 
ment. This reliance has led to an important degree 
of independence in the research program of the 
Institution. This independence is anticipated to 
continue as a mainstay of Carnegie's approach to 
science in the future. 

At June 30, 1999, the endowment was valued at 
approximately $451.6 million. For a number of 
years, Carnegie's endowment has been allocated 
among a broad spectrum of asset classes. This 
includes fixed-income instruments (bonds), equi- 
ties (stocks), absolute return investments, real 
estate partnerships, private equity, an oil and gas 
partnership and a hedge fund. The Finance 
Committee of the Board regularly examines the 
asset allocation of the endowment and readjusts the 
allocation, as appropriate. The Institution relies 
upon external managers and partnerships to con- 
duct these investment activities, and it employs a 
commercial bank to maintain custody. 

The goal of diversifying the endowment into alter- 
native assets is to reduce the volatility inherent in 
an undiversified portfolio while generating attrac- 
tive overall performance. 

In its private equity allocation, the Institution 
accepts a higher level of risk in exchange for a 
higher return. By entering into real estate partner- 
ships, the Institution in effect, holds part of its 



endowment in high-quality commercial real estate, 
deriving both capital appreciation and income in 
the form of rent from tenants. Along with the oil 
and gas partnership, this asset class provides an 
effective hedge against inflation. Finally, through 
its investments in an absolute return partnership 
and a hedge fund, the Institution seeks to achieve 
long-term returns similar to those of traditional 
U.S. equities with reduced volatility and risk. 

For the fiscal year ended on June 30, 1999, 
Carnegie's endowment had a total return (net of 
management fees) of 11.6%. The annualized five- 
year return for the endowment was 15.1%. 

The following chart shows the allocation of the 
Institution's endowment among the asset classes it 
uses as of June 30, 1999: 





Target 
Allocation 


Actual 
Allocation 


Common Stock 


35% 


35.4% 


Alternative Assets 


40% 


37.5% 


Fixed Income 


25% 


23.4% 


Cash 


0% 


3.7% 



Actual Asset Allocation 




35.4% Common Stock 



23.4% Fixed Income 



3.7% Cash 



37.5% Alt. Assets 



Endowment Spending Over Seven Years 



(Dollars in Millions) 
FY 



92-93 



93-94 



94-95 



95-96 



96-97 



97-98 



98-99 



Endowment 


















Spending 




$12.5 


$12.4 


$13.9 


$15.1 


$15.5 


$16.4 


$20.9 


Actual Market 


















Value at June 30 




$270.4 


$275.5 


$304.5 


$338.0 


$382.9 


$423.3 


$45 1 .6 


Actual Spending as 


°/ 

7o 
















of Market Value 




4.63% 


4.51% 


4.57% 


4.48% 


4.05% 


3.87% 


4.63% 


Planned Spending 


















Rate in Budget 




5.86% 


5.81% 


5.76% 


5.71% 


5.66% 


5.61% 


5.50% 




CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 131 



Carnegie's primary purpose is to maintain the 
long-term spending power of its endowment. To 
achieve this objective, it employs a budgeting 
methodology that provides for: 

• averaging the total market value of the 
endowment for the three most recent fiscal 
years, and 

• developing a budget that spends at a set per- 
centage (spending rate) of this three-year 
market average. 

During the 1990s, this budgeted spending rate 
has been declining in a phased reduction, moving 
towards an informal goal of an actual, average 
spending rate of 4.5%. For the 1998-1999 fiscal 
year, the rate was budgeted at 5.5%. While 
Carnegie has been reducing this budgeted rate by 
between 5 and 10 basis points a year, there has 
also been continuing, significant growth in the 
size^of the endowment. The result has been that, 
for the 1998-1999 fiscal year, the actual spending 
rate (the ratio of annual spending from the endow- 
ment to actual endowment value at the conclusion 
of the fiscal year in which the spending took place) 
was 4.63%. 

The table below left compares the planned versus 
the actual spending rates, as well as the market 
value of the endowment from 1991-1992 to the 
most recently concluded fiscal year, 1998-1999. 



Budgeted and Actual Spending Rates 




Actual Spending Rate Budgeted Spending Rate 

Within Carnegie's endowment, there are a num- 
ber of "Funds" that provide support either in a 
general way or in a targeted way, with a specific, 
defined purpose. The largest of these is the 
Andrew Carnegie Fund, begun with the original 
gift of $10 million. Mr. Carnegie later made 



additional gifts totaling another $12 million 
during his lifetime. This fund is now valued at 
nearly $376 million. 



UNAUDITED 



The following table shows the amounts in the 
principal funds within the institution's endowment 
as of June 30, 1999: 

Market value of the Principal Funds 
Within Carnegie's Endowment 



Andrew Carnegie 


$375,976,205 


Capital Campaign 


28,828,808 


Mellon Matching 


9,595,334 


Anonymous 


8,019,950 


Astronomy Funds 


7,490,092 


Anonymous Matching 


7,295,719 


Wood 


4,936,744 


Carnegie Futures 


3,234,707 


Golden 


3,028,396 


Bowen 


2,3 1 2,677 


Science Education Fund 


1 ,956,744 


Colburn 


1 ,907,247 


McClintock Fund 


1,497,552 


Special Instrumentation 


1,035,100 


Bush Bequest 


931,004 


Moseley Astronomy 


763,580 


Starr Fellowship 


723,253 


Special Opportunities 


687,603 


Roberts 


400,437 


Lundmard 


315,281 


Morgenroth 


232,288 


Hollaender 


222,507 


Moseley 


138,397 


Forbush 


1 3 1 ,085 


Bush 


1 10,700 


Green Fellowship 


97,244 


Harkavy 


88,744 


Hale 


88,206 




Total 


$462,045,604 



CARNEGIE INSTITUTION 



page 132 YEAR BOOK p8~pp 



inancial Statements 



fol 



V IBM I ■■WWI 



Independent Auditors' Report 




To the Auditing Committee of the 
Carnegie Institution of Washington: 

We have audited the accompanying statements of financial position of the Carnegie Institution of Washington 
(Carnegie) as of June 30, 1999 and 1998, and the related statements of activities and cash flows for the years 
then ended. These financial statements are the responsibility of Carnegie's management. Our responsibility is 
to express an opinion on these financial statements based on our audits. 

We conducted our audits in accordance with generally accepted auditing standards. Those standards require 
that we plan and perform the audit to obtain reasonable assurance about whether the financial statements 
are free of material misstatement. An audit includes examining, on a test basis, evidence supporting the 
amounts and disclosures in the financial statements. An audit also includes assessing the accounting principles 
used and significant estimates made by management, as well as evaluating the overall financial statement 
presentation. We believe that our audits provide a reasonable basis for our opinion. 

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial 
position of the Carnegie Institution of Washington as of June 30, 1999 and 1998, and its changes in net assets 
and its cash flows for the years then ended, in conformity with generally accepted accounting principles. 

Our audits were made for the purpose of forming an opinion on the basic financial statements taken as a 
whole. The supplementary information included in Schedule I is presented for purposes of additional analysis 
and is not a required part of the basic financial statements. Such information has been subjected to the 
auditing procedures applied in the audits of the basic financial statements and, in our opinion, is fairly 
presented in all material respects in relation to the basic financial statements taken as a whole. 



K^P/KGr lcp 



Washington, D.C 
October 29, 1999 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page ZJ3 



Statement 



Assets 



Cash and cash equivalents 
Accrued investment income 
Contributions receivable (note 2) 
Accounts receivable and other assets 
Bond proceeds held by trustee (note 6) 
Investments (note 3) 
Construction in progress (notes 4 and 5) 
Property and equipment net (note 4) 




Accounts payable and accrued expenses 

Deferred revenue (note 5) 

Broker payable (note 3) 

Bonds payable (note 6) 

Accrued postretirement benefits (note 7) 

Total liabilities 

Net assets (note 8): 
Unrestricted: 
Board designated: 
Invested in fixed assets, net 
Designated for managed investments 
Undesignated 




osition 



1999 




247,697 

537,470 

2,119,791 

4,096,520 

1,665,390 

462,045,604 

54,056,641 

45,333,399 



570,102,512 



$ 2,896,622 
25,476,955 

34,843,325 
9,968,543 

73,185,445 



39,069,760 

401,014,333 

5,190,932 



1998 



147,343 

665,437 

2,414,271 

2,573,029 

7,162,230 

431,802,740 

40,642,497 

41,607,41 I 

527,014,958 



2,409,330 
12,108,046 

2,171,665 
34,806,460 

9,836,437 

61,331,938 



35,335,402 

369,733,863 

10,489,238 



445,275,025 



415,558,503 



Temporarily restricted 
Permanently restricted 



14,002,694 
37,639,348 



14,172,427 
35,952,090 



Total net assets 



496,917,067 



465,683,020 



Commitments and contingencies (notes 9, 1 0, and I I ) 



See accompanying notes to financial statements. 




$570,102,512 



527,014,958 



CARNEGIE INSTITUTION 



page 134 I YEAR BOOK p8~pp 



Statements 



Years ended June 30, 1 999 and 1998 




Temporarily Permanently 
Unrestricted restricted restricted Total 




Temporarily Permanently 
restricted restricted restricted Total 



Revenues and support: 

Grants and contracts $ 1 2,0 1 3, 1 29 

Contributions and gifts 77,80 1 
Net gain (loss) on disposals 

of property 60,558 

Other income 1 , 1 88,846 



Net external revenue 



3,340,334 



Investment income (note 3) 45,2 1 0,087 
Net assets released from 
restnctions (note 8) 6, 1 1 3,93 1 



3,9 1 6,380 


1 ,630,265 


12,013,129 
5,624,446 


11,259,930 
709,030 


3,894,584 


1,144,309 


11,259,930 
5,747,923 


— 


1 ,630,265 


60,558 
1 , 1 88,846 


(90,224) 
720,656 


— 


— 


(90,224) 
720,656 


3,9 1 6,380 


1 8,886,979 


12,599,392 


3,894,584 


1,144,309 


17,638,285 


2,027,818 


56,993 


47,294,898 


54,982,546 


4,016,507 


124,973 


59,124,026 



(6,113,931) 



9,324,754 (9,324,754) 



Total revenues, gains, and 
other support 64,664,352 



(169,733) 1,687,258 66,181,877 76,906,692 (1,413,663) 1,269,282 76,762,3 



Program and supporting services expenses: 



Terrestrial Magnetism 


6,576,909 


Observatories 


6,687,508 


Geophysical Laboratory 


6,868,289 


Embryology 


5,567,359 


Plant Biology 


4,840,61 1 


Other Programs 


1,005,455 


Administrative and 




general expenses 


3,401,699 


Total expenses 


34,947,830 


Increase (decrease) in 




net assets 


29,716,522 



6,576,909 


6,221,701 


6,687,508 


5,799,559 


6,868,289 


6,283,859 


5,567,359 


5, 1 63,256 


4,840,611 


4,562,436 


1,005,455 


1,050,946 


3,401,699 


2,316,114 


34,947,830 


31,397,871 




6,221,701 
5,799,559 
6,283,859 
5, 1 63,256 
4,562,436 
1,050,946 

2,316,114 

,397,871 



(169,733) 1,687,258 31,234,047 45,508,821 (1,413,663) 1,269,282 45,364,440 



Net assets at the beginning 
of the year 415,558,503 



4,172,427 35,952,090 465,683,020 370,049,682 15,586,090 34,682,808 420,318,580 



Net assets at the end 
of the year 



$445,275,025 14,002,694 37,639,348 496,917,067 415,558,503 14,172,427 35,952,090 465,683,020 



See accompanying notes to financial stateme 




Statements of Cash Flows 



Years ended June JU, I VVV and I yyb 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page I$$ 



1999 



1998 




Cash flows from operating activities: 
Increase in net assets 
Adjustments to reconcile increase in net assets to 
net cash provided by operating activities: 
Depreciation 
Net gains on investments 
Loss (gain) on disposal of property 
Amortization of bond issuance costs and discount 
Contribution of stock 
(Increase) decrease in assets: 
Receivables 

Accrued investment income 
Increase in liabilities: 
Accounts payable and accrued expenses 
Deferred revenues 
Accrued postretirement benefits 
Contributions and investment income restricted for 
long-term investment 

Net cash provided by (used for) operating activities 

Cash flows from investing activities: 
Draws from bond proceeds held by trustee 
Acquisition of property and equipment 
Construction of telescope, facilities, and equipment 
Investments purchased, net of change in broker payable of 

$0 and ($2, 1 7 1 ,665) in 1 999 and 1 998, respectively 
Proceeds from investments sold or matured 

Net cash (used for) provided by investing activities 



Cash flows from financing activities - proceeds from contributions 
and investment income restricted for 
Investment in endowment 
Investment in property and equipment 



Net cash provided by financing activities 

Net increase (decrease) in cash and cash equivalents 
Cash and cash equivalents at the beginning of the year 
Cash and cash equivalents at the end of the year 



Supplementary cash flow information 
Cash paid for interest 



,234,047 



2,902,842 
(37,191,987) 
(60,558) 
36,865 
(543, 1 36) 

(1,229,01 I) 
127,967 

487,292 
1 3,368,909 

132,106 

(4,350,629) 
4,914,707 



5,496,840 
(6,568,272) 
(13,414,144) 

(474,633,607) 
479,954,201 

(9, 1 64,982) 



1,630,265 
2,720,364 




$ 1,488,410 




45,364,440 

2,488,284 
(47,591,512) 
90,224 
36,865 
(1,425,784) 

793,664 
(169,530) 

341,236 

10,958,996 

599,454 

(2,716,782) 

8,769,555 



3,997,646 
(6,305,806) 
(11,905,053) 

(427,075,566) 
427,190,728 

(14,098,051) 



1 ,269,282 

1 ,447,500 

2,7 1 6,782 
(2,61 1,714) 
2,759,057 
147,343 

1,568,792 



See accompanying notes to financial statements 




CARNEGIE INSTITUTION 



page I36\ YEAR BOOK p8~pp 



Notes to Financial Statements 



June 30, 1 999 and 1998 

(I) Organization and Summary of Significant 
Accounting Policies 

Organization 

The Carnegie Institution of Washington (Carnegie) 
conducts advanced research and training in the sci- 
ences. It carries out its scientific work in five 
research centers located throughout the United 
States and at an observatory in Chile. The centers 
are the Departments of Embryology, Plant Biology, 
and Terrestrial Magnetism, the Geophysical 
Laboratory, and the Observatories (astronomy). 
Income from investments represents approximately 
75 percent of Carnegie's total revenues. Carnegie's 
external income is mainly from gifts and federal 
grants and contracts. 

Basis of Accounting and Presentation 

The financial statements are prepared on the accrual 
basis of accounting. Contributions and gifts rev- 
enues are classified according to the existence or 
absence of donor-imposed restrictions. Also, satis- 
faction of donor-imposed restrictions are reported as 
releases of restrictions in the statements of activities. 

Investments and Cash Equivalents 

Carnegie's debt and equity investments are reported 
at their fair values. Carnegie also reports invest- 
ments in partnerships at fair value as determined 
and reported by the general partners. All changes in 
fair value are recognized in the statements of activi- 
ties. Carnegie considers all highly liquid debt instru- 
ments purchased with remaining maturities of 
90 days or less to be cash equivalents. Money mar- 
ket and other highly liquid instruments held by 
investment managers are reported as investments. 

Income Taxes 

Carnegie is exempt from federal income tax under 
Section 501(c)(3) of the Internal Revenue Code 
(the Code). Accordingly, no provision for income 
taxes is reflected in the accompanying financial 



statements. Carnegie is also an educational institu- 
tion within the meaning of Section 170(b)(l)(A)(ii) 
of the Code. The Internal Revenue Service has clas- 
sified Carnegie as other than a private foundation, 
as defined in Section 509(a) of the Code. 

Fair Value of Financial Instruments 

Financial instruments of Carnegie include cash 
equivalents, receivables, investments, bond proceeds 
held by trustee, accounts and broker payables, and 
bonds payable. The fair value of investments in debt 
and equity securities is based on quoted market 
prices. The fair value of investments in limited part- 
nerships is based on information provided by the 
general partners. 

The fair value of Series A bonds payable is based on 
quoted market prices. The fair value of Series B 
bonds payable is estimated to be the carrying value, 
since these bonds bear adjustable market rates. 

The fair values of cash equivalents, receivables, and 
accounts and broker payables approximate their car- 
rying values based on their short maturities. 

Use of Estimates 

The preparation of financial statements in confor- 
mity with generally accepted accounting principles 
requires management to make estimates and 
assumptions that affect the reported amounts of 
assets and liabilities and disclosure of contingent 
assets and liabilities at the date of the financial 
statements. They also affect the reported amounts of 
revenues and expenses during the reporting period. 
Actual results could differ from those estimates. 

Property and Equipment 

Carnegie capitalizes expenditures for land, buildings 
and leasehold improvements, telescopes, scientific 
and administrative equipment, and projects in 
progress. Routine replacement, maintenance, and 
repairs are charged to expense. 

Depreciation is computed on a straight-line basis 
over the following estimated useful lives: 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page I$J 



Buildings and telescopes 
Leasehold improvements 



50 years 

lesser of 25 years or the 

remaining term of the 

lease 



Scientific and 

administrative equipment 5 years 

Contributions 

Contributions are classified based on the existence 
or absence of donor-imposed restrictions. 
Contributions and net assets are classified as follows: 

Unrestricted - includes all contributions 
received without donor-imposed restrictions on 
use or time. 

Temporarily restricted - includes contributions 
with donor-imposed restrictions as to purpose of 
gift or time period expended. 

Permanently restricted - generally includes 
endowment gifts in which donors stipulated that 
the corpus be invested in perpetuity. Only the 
investment income generated from endowments 
may be spent. Certain endowments require that 
a portion of the investment income be reinvested 
in perpetuity. 

Gifts of long-lived assets, such as buildings or 
equipment, are considered unrestricted when placed 
in service. Cash gifts restricted for investment in 
long-lived assets are released from restriction when 
the asset is acquired or as costs are incurred for asset 
construction. 

Grants 

Carnegie records revenues on grants from federal 
agencies only to the extent that reimbursable 
expenses are incurred. Accordingly, funds received 
in excess of reimbursable expenses are recorded as 
deferred revenue, and expenses in excess of reim- 
bursements are recorded as accounts receivable. 
Reimbursement of indirect costs is based upon pro- 
visional rates which are subject to subsequent audit 
by Carnegie's federal cognizant agency, the National 
Science Foundation. 



Allocation of Costs 

The costs of providing programs and supporting 
services have been summarized in the statements 
of activities. Accordingly, certain costs have been 
allocated among the programs and supporting 
services benefited. 

Reclassifications 

Certain prior year amounts were reclassified to 
conform to the current year presentation. 

(2) Contributions Receivable 

Contributions receivable representing unconditional 
promises expected to be collected are summarized as 
follows at June 30, 1999 and 1998: 



Years ending June 30, 



1999 



1998 



2000 


$ 825,100 


2,041,690 


2001 


665,000 


144,690 


2002 


400,000 


102,000 


2003 


14,938 


71,891 


2004 


10,000 


27,000 


2005 and later 


204,753 


27,000 



$2,119,791 2,414,271 



(3) Investments 



At June 30, 1999 and 1998, investments at fair value 
consisted of the following: 



1999 



1998 



Time deposits and money 

market funds $ 1 29,474,938 

Debt mutual funds 
Debt securities 
Equity securities 
Real estate partnerships 
Limited partnerships 



4,707,63 1 

8,385,121 

149,946,198 

53,058,884 

I 16,472,832 



20,253,740 
55,886,196 
40,07 1 ,660 
55,190,157 
5 1 ,744,690 
08,656,297 



$462,045,604 431,802,740 



CARNEGIE INSTITUTION 



page 138 I YEAR BOOK p8~pp 



Investment income for the years ended June 30, 
1999 and 1998, consisted of the following: 



1999 



1998 



Interest and dividends $ 1 1 ,484,577 


1 3,092,269 


Telescope 


$50,73 1 ,430 


38,447,209 


Net realized gains 24, 1 24,433 


28,100,705 


Buildings 


802,523 


1,147,369 


Net unrealized gains 1 3,067,554 


19,490,807 


Scientific equipment 


2,522,688 


1,047,919 


Less — investment 










management expenses ( 1 ,38 1 ,666) 


(1,559,756) 




$54,056,641 


40,642,497 



$47,294,898 59,124,025 

Carnegie purchased and sold certain investment 
securities on dates prior to June 30, 1998. These 
trades were settled subsequent to June 30, 1998, and 
are reflected in the investment balances reported at 
year end. The net obligation for these unsettled 
trades is reported as broker payable in the accompa- 
nying statements of financial position. 

As of June 30, 1999, the fair value for approximately 
$43 million of Carnegie's $170 million of real estate 
and limited partnership investments has been esti- 
mated by the general partners in the absence of 
readily ascertainable market values. However, these 
estimated fair values may differ from the values that 
would have been used had a ready market existed. 

(4) Property and Equipment 

At June 30, 1999 and 1998, property and equipment 
placed in service consisted of the following: 



1999 



1998 



Buildings and 






improvements 


$ 43,569,957 


38,904,093 


Scientific equipment 


17,379,687 


15,917,470 


Telescopes 


7,910,825 


7,910,825 


Administrative equipment 


2,507,290 


2,334,975 


Land 


787,896 


787,896 


Art 


34,067 


34,067 




72,189,722 


65,889,326 


Less accumulated 






depreciation 


26,856,323 


24,28 1 ,9 1 5 



$45,333,399 41,607,411 



At June 30, 1999 and 1998, construction in progress 
consisted of the following: 



1999 



1998 



At June 30, 1999 and 1998, approximately $59 mil- 
lion and $44 million, respectively, of construction 
in progress and other property, net of accumulated 
depreciation, was located in Las Campanas, Chile. 
During 1999 and 1998, Carnegie capitalized 
interest costs (net of interest earned of $245,000 
and $489,000, respectively) of approximately 
$1,229,000 and $1,118,000, respectively, as 
construction in progress. 

(5) Magellan Consortium 

During the year ended June 30, 1998, Carnegie 
entered into an agreement (Magellan Agreement) 
with four universities establishing a consortium to 
build and operate the Magellan telescopes. The two 
Magellan telescopes are currently under construc- 
tion on Manqui Peak, Las Campanas in Chile. The 
total construction costs of the two telescopes is 
expected to be approximately $72 million and will 
be recorded as assets by Carnegie. Title to the 
Magellan facilities is held by Carnegie. As of 
June 30, 1999, construction in progress of 
$50,731,430 related to the Magellan project. 

The university members of the consortium, by con- 
tribution to the construction and operating costs of 
Magellan, acquire rights of access and oversight as 
described in the Magellan Agreement. Total contri- 
butions by the university members for construction 
are expected to be $36 million, 50% of the total 
expected costs and these monies are being used by 
Carnegie to finance part of the Magellan Telescopes' 
construction costs. As of June 30, 1999, the universi- 
ty members had contributed $24,910,264 which is 
included in deferred revenue in the accompanying 
statements of financial position. The deferred rev- 
enue will be recognized ratably as income over the 
estimated useful lives of the telescopes. 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page I$p 



(6) Bonds Payable 

On November 1, 1993, Carnegie issued $17.5 mil- 
lion each of secured Series A and Series B 
California Educational Facilities Authority Revenue 
tax-exempt bonds. Bond proceeds are used to 
finance the Magellan telescope project and the ren- 
ovation of the facilities of the Observatories at 
Pasadena. The balances outstanding at June 30, 
1999 and 1998, on the Series A issue totaled 
$17,402,913 and $17,380,068, respectively, and on 
the Series B issue totaled $17,440,413 and 
$17,426,392, respectively. The balances outstanding 
are net of unamortized bond issue costs and bond 
discount. Bond proceeds held by the trustee and 
unexpended at June 30, 1999 and 1998, totaled 
$1,665,390 and $7,162,230, respectively. 

Series A bonds bear interest at 5.6 percent payable 
in arrears semiannually on each April 1 and 
October 1 and upon maturity on October 1, 2023. 
Series B bonds bear interest at variable money mar- 
ket rates (ranging from 2.8% to 3.2% at June 30, 
1999) in effect from time to time, up to a maximum 
of 12 percent over the applicable money market rate 
period of between one and 270 days and have a 
stated maturity of October 1, 2023. At the end of 
each money market rate period, Series B bondhold- 
ers are required to offer the bonds for repurchase 
at the applicable money market rate. If repurchased, 
the Series B bonds would be resold at the current 
applicable money market rate and for a new 
rate period. 

Carnegie is not required to repay the Series A and B 
bonds until the October 1, 2023, maturity date, and 
Carnegie has the intent and the ability to effect the 
purchase and resale of the Series B bonds through a 
tender agent; therefore all bonds payable are classi- 
fied as long term. Sinking fund redemptions begin 
in 2019 in installments for both series. The fair 
value of Series A bonds payable at June 30, 1999 
and 1998, based on quoted market prices is estimat- 
ed at $18,043,000 and $18,600,000, respectively. 
The fair value of Series B bonds payable at June 30, 
1999 and 1998, is estimated to approximate carrying 
value as the mandatory tender dates on which the 
bonds are repriced are generally within three 
months of year end. 



(7) Employee Benefit Plans 

Retirement Plan 

Carnegie has a noncontributory, defined contribu- 
tion, money-purchase retirement plan in which all 
United States personnel are eligible to participate. 
After one year's participation, an individual's 
benefits are fully vested. The Plan has been 
funded through individually owned annuities 
issued by Teachers' Insurance and Annuity 
Association (TIAA) and College Retirement 
Equities Fund (CREF). Total contributions made 
by Carnegie totaled approximately $2,133,000 and 
$1,851,000 for the years ended June 30, 1999 and 
1998, respectively. 

Postretirement Benefits Plan 

Carnegie provides postretirement medical benefits 
to all employees who retire after age 55 and have at 
least ten years of service. Cash payments made by 
Carnegie for these benefits totaled approximately 
$318,000 and $341,000 for the years ended June 30, 
1999 and 1998, respectively. 

The expense for postretirement benefits for the 
years ended June 30, 1999 and 1998 consists of the 
following: 



1999 



1998 



Service cost - benefits earned 

during the year $283,000 237,000 

Interest cost on projected 

benefit obligation 531,000 502,000 

Amortization of gain (45,000) ( I 1 2,000) 



Accrued postretirement 
benefit cost 



$769,000 



627,000 



The 1999 postretirement benefits expense was 
approximately $451,000 more than the cash expense 
of $318,000, and the 1998 postretirement benefits 
expense was approximately $286,000 more than the 
cash expense of $341,000. The postretirement 
benefits expense was allocated among program and 
supporting services expenses in the statements of 
activities. 



CARNEGIE INSTITUTION 



page 140 I YEAR BOOK p8~pp 



The reconciliation of the Plan's funded status to 
amounts recognized in the financial statements at 
June 30, 1999 and 1998 follows: 



1999 



Benefit obligation 
at end of year 



7,848,000 



Prepaid (accrued) 
benefit cost 



1998 



Change in benefit obligation: 
Benefit obligation at 

beginning of year $ 8,041,000 

Service cost 283,000 

Interest cost 531,000 

Actuarial gain (689,000) 

Benefits paid (3 1 8,000) 



9,237,000 
237,000 
502,000 

(1,594,000) 
(341,000) 



8,041,000 



Change in plan assets: 
Fair value of plan assets at 

beginning of year 
Actual return on 

plan assets — 

Contribution to plan 3 1 8,000 

Benefits paid ( 3 1 8,000) 



341,000 
(341,000) 



Fair value of plan assets 
at end of year 


— 


— 


Funded status 


(7,848,000) 


(8,041,000) 


Unrecognized net 
actuarial gain 


(2, 1 20,000) 


(1,795,000) 



$(9,968,000) (9,836,000) 



The present value of the benefit obligation as of 
June 30, 1999, was determined using an assumed 
health care cost trend rate of 9.0 percent and an 
assumed discount rate of 7.5 percent. The present 
value of the benefit obligation as of June 30, 1998, 
was determined using an assumed health care cost 
trend rate of 9.4 percent and an assumed discount 
rate of 6.75 percent. Carnegie's policy is to fund 
postretirement benefits as claims and administrative 
fees are paid. 

For measurement purposes, a 9.0 percent annual 
rate of increase in the per capita cost of covered 
health care benefits was assumed for 1999; the rate 



was assumed to decrease gradually to 5.5 percent in 
12 years and remain at that level thereafter. The 
health care cost trend rate assumption has a signifi- 
cant effect on the amounts reported. A one-percent- 
age change in assumed annual health care cost trend 
rate would have the following effects: 

One-percentage One-percentage 
point increase point decrease 

Effect on total of 

service and interest 

Cost components $ 1 65,000 ( 1 40,000) 



Effect on 
postretirement 
benefit obligation 

(8) Net Assets 



1 ,023,000 



(837,000) 



At June 30, 1999 and 1998, temporarily restricted 
net assets were available to support the following 
donor-restricted purposes: 



1999 



1998 



Specific research 

programs 
Equipment acquisition 

and construction 



$10,479,226 9,278,140 



3,523,468 4,894,287 



$14,002,694 14,172,427 

At June 30, 1999 and 1998, permanently restricted 
net assets consisted of permanent endowments, the 
income from which is available to support the fol- 
lowing donor-restricted purposes: 



1999 



1998 



Specific research 

programs 
Equipment acquisition 

and construction 
General support 

(Carnegie endowment) 22,000,000 22,000,000 



$14,434,629 12,747,37 



1,204,719 1,204,719 



$37,639,348 35,952,090 



I 



CARNEGIE INSTITUTION 



YEAR BOOK p8~pp page 141 



During 1999 and 1998, Carnegie met 
donor-imposed requirements on certain gifts and, 
therefore, released temporarily restricted net assets 
as follows: 



1999 



1998 



Specific research programs 
Equipment acquisition and 
construction 



$2,022,748 3,979,778 



4,09 1,183 5,344,976 



$6,113,931 9,324,754 

(9) Federal Grants and Contracts 

Costs charged to the federal government under 
cost-reimbursement grants and contracts are subject 
to government audit. Therefore, all such costs are 
subject to adjustment. Management believes that 
adjustments, if any, would not have a significant 
effect on the financial statements. 

(10) Commitments 

In 1997, Carnegie entered into a contract with the 
University of Arizona for the construction of the 
primary mirror and support system for the second 
telescope in the Magellan project. The amount of 
the contract is approximately $9,700,000 of which 
approximately $3,646,000 had not been incurred at 
June 30, 1999. Carnegie had previously entered into 
an agreement with the University of Arizona for the 
primary mirror and support system for the first tele- 
scope and had outstanding commitments of approx- 
imately $63,490 at June 30, 1999. Carnegie also has 
other contracts relating to the construction of 
Magellan with outstanding commitments totaling 
approximately $3,758,547. 

Carnegie has outstanding commitments to invest 
approximately $25 million in limited partnerships. 



(11) Lease Arrangements 

Carnegie leases a portion of the land it owns in Las 
Campanas, Chile to other organizations. These 
organizations have built and operate telescopes on 
the land. Most of the lease arrangements are not 
specific and some are at no-cost to the other organi- 
zations. One of the lease arrangements is noncance- 
lable and has annual future rents of $120,000 
through fiscal year 2001. For the no-cost leases, the 
value of the leases could not be determined and is 
not considered significant, and, accordingly, contri- 
butions have not been recorded in the financial 
statements. 

Carnegie also leases a portion of one of its laborato- 
ries to another organization for an indefinite term. 
Rents to be received under the agreement are 
approximately $339,000 annually, adjusted for 
CPI increases. 

Carnegie leases land and buildings. The monetary 
terms of the leases are considerably below fair value, 
however, these terms were developed considering 
other non-monetary transactions between Carnegie 
and the lessors. The substance of the transactions 
indicates arms-length terms between Carnegie and 
the lessors. The monetary value of the leases could 
not be determined, and has not been recorded in the 
financial statements. 

(1 2) Year 2000 

Carnegie is in the process of addressing anticipated 
operational issues resulting from the Year 2000. 
The Year 2000 problem is typically the result of 
computer programs using two digits rather than four 
digits to define the applicable year for date interpre- 
tation. Management believes that mission-critical 
systems will be functioning as necessary to avoid any 
major business interruption. However, no assurance 
can be given that Carnegie can or will become Year 
2000 compliant. 



CARNEGIE INSTITUTION 



page 142 I YEAR BOOK p8~pp 



Schedules of Expenses 

Schedule 1 

Years ended lune 30, 1999 and 1998 



Carnegie 
funds 



1999 



Federal and 
private 
grants 



Total 
expenses 



998 



Federal and 

Carnegie private 

funds grants 



Total 
expenses 



Personnel costs: 
Salaries $11,268,614 3,171,189 14,439,803 10,341,061 2,852,217 13,193,278 

Fringe benefits and payroll taxes 3,975,980 869,052 4,845,032 3,512,361 773,285 4,285,646 



Total personnel costs 


1 5,244,594 


4,040,24 1 


19,284,835 


13,853,422 


3,625,502 


1 7,478,924 


Fellowship grants and awards 


1,319,122 


983,363 


2,302,485 


1,325,949 


888,367 


2,214,316 


Depreciation 


2,902,842 


— 


2,902,842 


2,474,898 


— 


2,474,898 



General expenses: 

Educational and research supplies 988,536 1,365,473 2,354,009 866,150 

Building maintenance and operation 2,315,995 57,701 2,373,696 1,512,049 

Travel and meetings 690,237 530,656 1,220,893 634,442 

Publications 33,249 57,932 91,181 38,197 

Shop 57,705 57,705 57,282 

Telephone 199,023 10,438 209,461 175,120 

Books and subscriptions 264,491 7,430 271,921 226,358 

Administrative and general 683,797 163,110 846,907 647,577 

Printing and copying 148,385 8,465 156,850 91,256 

Shipping and postage 134,230 36,591 170,821 110,560 

Insurance, taxes and professional fees 740,853 164,278 905,131 663,824 

Equipment 1,432,203 1,432,203 



,000,382 

33,229 

530,816 



12,613 

9,328 

1 6 1 ,494 

2,546 

65,522 

1 38,847 

,914,681 



Capitalized scientific equipment and 
construction projects funded by 
Federal and private grants 



,866,532 

,545,278 

,165,258 

1 23,095 

57,282 

187,733 

235,686 

809,071 

93,802 

176,082 

802,671 

,914,681 



Fund-raising expense 


366,890 


— 


366,890 


321,420 


— 


321,420 


Total general expenses 


6,623,391 


3,834,277 


10,457,668 


5,344,235 


3,954,356 


9,298,591 


Indirect costs - grants 


(3,155,248) 


3,155,248 


— 


(2,79 1 ,705) 


2,79 1 ,705 


— 



(68,858) 



(68,858) 



$22,934,701 



12,013,129 



34,947,830 



20,137,941 11,259,930 31,397,871 



Index of Names 



CARNEGIE INSTITUTION 



YEAR BOOK p8—pp I page 143 



Abelson, Philip H„ 7, 82 

Aciemo, Michael, 122, 124 

Alcazar, Rosa, 59 

Aldrich, L Thomas, 124 

Alexander, Conel M. O'D., 85, 114-115, 124 

Anderson, Don L, 1 24 

Antoszyk Andy, 16, 1 00 

Armstrong, Lora, 100 

Asa, joe, 73, 76 

Ash, Richard D., 98, 100, 115, 124 

Babcock, Horace, 1 9 

Badro, James, 1 00 

Baird, Euan, 7 

Bauer, Jacob, 124 

Bebie, Joakim, 100, 124 

Beckett, Martin, 76 

Bell, Peter M., 1 00 

Bellini, Michel, 59 

Benton, Laurie D., 1 24 

Berengaut, Alexander, 19, 1 00 

Bernstein, Rebecca, 73, 76 

Berry, Joseph A, 1 3, 29-32 

Bertka, Constance, 83-84, 90, 1 00 

Bertoglio, Valarie, 59 

Bhaya, Devaki, 42 

Bigelow, Bruce, 76 

Bjorkman, Olle E„ 1 6, 27, 29-30, 42 

Black, Richard, 1 6, 76 

Bloomfield, Emily, 1 00 

Boctor, Nabil Z, 84-85, 100 

Borjigin, Jimo, 18,46,47,59 

Boss, Alan P., 14, I 12-113, 114, 124 

Boyce, Charles Kevin, 1 00, 1 24 

Boyd, Francis R, Jr., 85-86, 1 00 

Brandes, Jay A, 100 

Brandt, Kirsten A, 1 24 

Bredthauer, Greg, 73, 76 

Briggs, Winslow R, 1 8, 30, 32-34, 42 

Brown, Donald D., 47-48, 59 

Brown, Louis, 1 24 

Burley, Greg, 76 

Butler, Paul, 17, 106, 110-112, 113, 114 

Buttitta, Laura, 59 

Calvi, Brian, 59 

Carlson, Richard W., I 1 5, I 1 9, 1 24 
Carr, Dave, 73, 76 
Cerda, Emilio, 73, 76 
Chapman, Scott, 76 
Chick, Kenneth M., 1 24 
Christie, John Mackie, 33, 42 
Cifuentes, Ines, 1 28 

Director's essay, 23-25 
Cody, George D., 83, 86-87, 91,92, 1 00 
Cohen, Ronald E., 87-88, 1 00 
Coleman, William T„ Jr., 7 
Conrad, Pamela G, 100 
Cori, Tom, 7, 1 7 
Cox, Rachel, 59 
Craig, Pat, 17, 128 
Crawford, John F., 7 
Cutler, Sean, 34, 42 

Dalcanton, Julianne, 76 
Das, Biswajit, 59 
David, Edward E., Jr., 7 



de Araujo, Ana Lucia Novaes, 1 24 

De Boer, Geert jan, 42 

de Cuevas, Maggie, 59 

De, Subarnarekha, 1 00 

Dera, Przemyslaw, 96, 1 00 

DeSantis, Stacia, 1 00 

Diebold, John, 7 

Domfnguez, Jaime, 124 

Doyle, Olivia, 59 

Dressier, Alan, 19,64-65,76 

Drummond-Barbosa, Daniela, 59 

Ebert, James D., 7 

Ehrhardt, David, 34-35, 42 

Elrad, Dafna, 42 

Eremets, Mikhail, 17,88-89,99, 100 

Ernst, W. Gary, 7 

Ewing, Rob, 42 

Faber, Sandra M„ 7, 1 8 

Fan, Chen-Ming, 46, 49, 59 

Farber, Steve, 52, 59 

Fassett, Caleb I., 109, 124 

Faulkner, Sarah E., 100, 124 

Fei, Yingwei, 84, 86, 89-90, 95, 100 

Fens, Vanessa, 42 

Ferguson, Bruce W., 7, 1 8 

Field, Christopher B, 1 3, 35-36, 42 

Filley, Timothy R„ 1 00 

Finger, Larry W., 1 6, 92, 96, 1 00 

Finkelstein, David, 42 

Fire, Andrew Z„ 50-5 1 , 59 

Fisher, Shannon, 52, 59 

Fogel, Marilyn L, 82, 90-9 1 , 92, 1 00 

Fouch, Matthew J., 1 00, 1 24 

Frantz, John D., 9 1 , 1 00 

Freed, Andrew M., 1 24 

Freedman, Wendy, 1 2, 65-66, 76 

Fricke, Henry C, 98, 1 00 

Frydman, Horacio, 59 

Fu, Huaxiang, 88, 1 00 

Fu, Wei, 42 

Galaz, Gaspar, 76 

Gall, Joseph G, 1 8, 5 1 , 59 

Gallart, Carme, 76 

Gantz, Joan, 1 7, 76 

Gao, Stephen S., 1 22, 1 24 

Garvey, Susanne, 7, 1 28 

Gellert, Michael E„ 7 

Giavalisco, Mauro, 76 

Gillmor, Stewart, 42 

Goelet, Robert G„ 7 

Golden, William T, 7, 16 

Goncharov, Alexander, 9 1 -92, 1 00 

Gore, Jane, 1 24 

Graham, John A, 12, 109-1 10, 124 

Gramsch, Stephen A., 88, 1 00 

Granger, Claire, 42 

Gray, Caprice L, 1 24 

Greenewalt, David, 7 

Gregoryanz, Eugene A„ 1 00 

Grieder, Nicole, 59 

Grossman, Arthur R, 27, 28, 30, 37-38, 42 

Guacci, Vincent, 59 

Gulseren, Oguz, 100 

Gunawardane, Ru, 59 



Hadley, Stephen, 1 00 

Halpern, Mamie, 18,46,51-52,59 

Han, In-Seob, 42 

Handler, Monica R., 1 24 

Handwerger, Korie, 59 

Hare, P. Edgar, 16, 1 00 

Hashimoto, Yasuhiro, 76 

Haskins, Caryl P., 7, 9 

Hauri, Erik H., 85, II 7- 1 18, 124 

Hazen, Robert M., 83, 9 1 , 92-93, 96, 1 00 

Hearst, William R, III, 7 

Heckert, Richard E., 7 

Hemley, Russell J., 8 1 , 9 1 , 92, 93-94, 95, 

98, 100 
Hewlett, William R, 7 
Hibbert, Heather, 1 00 
Ho, Luis, 63, 66-67, 76 
Hoffman, Laura, 42 
Hoffman, Neil E„ 27 
Hooft, Emilie E. E„ 124 
Hsieh, Jenny, 59 
Hu.Jingzhu, 100 
Huala, Eva, 28, 42 
Huang, Dongli, 59 
Huang, Haochu, 59 
Hull, Charlie, 73, 76 
Huntress, Wesley T, Jr., 7, 1 8, 1 00 

Director's introduction, 8 1 -83 

lizuka, Yoshiyuki, 1 00 
lm, Chung-Soon, 42 
Inaba, Satoshi, 1 24 
Inamori, Kazuo, 7 
Irvine, Gordon J„ 1 24 
Irvine, T. Neil, 94-95, 100 

James, Charles, 1 28 

Director's essay, 23-25 
James, David E„ 1 24 
Janney, Philip E., 124 
Jiao, Wenjie, 90, 100, 124 
Joe, Valerie, 1 00 
Joel, Geeske, 42 
Johns, Matt, 73, 76 
Johnson, Suzanne Nora, 7 

Kaduk Jorg, 42 
Kehoe, David M., 42 
Kehoe, Kenneth, 96, 1 00 
Kelly, Patrick L, 1 24 
Kelly, William, 59 
Kelson, Daniel D., 124 
Khatry, Deepak, 42 
Kitchell, Stefanie L, 1 00 
Konzett, Jurgen, 97, 1 00 
Kortenkamp, Stephen J., 1 24 
Koshland, Douglas E, 47, 53, 59 
Kostas, Steve, 59 
Kunkel, William, 67, 76 



Laloraya, Shika, 59 
Lassiter, John C, 1 24 
Laubach, Gerald D„ 7, 1 6 
Lavoie, Brigitte, 59 
Lee, Catherine, 59 
Li.Jie, 89, 100, 124 



CARNEGIE INSTITUTION 



PAGE 144 I YEAR BOOK p8~pp 





Liang, Jennifer, 52, 59 

Linde, Alan T., 120-121, 1 22, 1 24 

Liu, Hong, 1 24 

Liu, Kelly, 59 

Liu, Zhen-Xian, 1 00 

Lively, John J., 7, 128 

Lizarraga, Sofia, 59 

Lukowitz, Wolfgang, 42 

Lund, Chris, 42 

Ma, Yanzhang, 100 

Mac Gregor, Ian D., 1 24 

Macomber, John D., 7, 1 6 

Madore, Barry, 1 2, 76 

Maglares, George, 1 00 

Mao, Ho-kwang, 8 1 , 82, 9 1 , 95, 98, 1 00 

Marsh-Armstrong, Nick 59 

Marton, Frederic C, 1 00 

Marzke, Ron, 62, 68, 76 

Matunis, Erika, 45, 53-54, 59 

McCarthy, Patrick 62, 67-68, 76 

McDowell, Tina, 17, 128 

McGovern, Patrick J., 124 

McMurtry, Burton J., 7 

McWhorter, Nelson, 1 22, 1 24 

McWilliam, Andrew, 68-69, 7 1 , 74, 76 

Mead, Jaylee, 7, 1 7 

Megee, Paul, 59 

Menzies, Andrew H., 1 24 

Merkel, Sebastien, 1 00 

Meserve, Richard A., 7, 1 8 

Mical, Timothy, 59 

Michaud, Jacques, 59 

Miller, Sarah, 100 

Minarik, William G., 100, 124 

Mock Timothy, I 1 5 

Mueller, Kaisa E, 1 24 

Mulchaey, John, 17,63,67,76 

Murphy, David, 76 

Murphy, Terence, 1 7, 45, 54-55, 59 

Mysen, Bjom O., 9 1 , 95-96, 100 

Newmark, Phil, 59 

Nguuri, Teresia K, 1 24 

Nguyen, Lan-Anh Ngoc, 115, 1 24 

Nicholas, Jason, 96, 100 

Nicholson, Frank, 30, 42 

Nishimura, Marc, 42 

Nittler, Larry R, 124 

Noblin, Xavier, 1 00 

Noser, Christopher, 1 00 

Oemler, Augustus, Jr., 7, 67, 76 
Director's introduction, 6 1 -64 
Olney, Margaret, 33, 42 

Pandit, Ben, 1 22, 1 24 

Park Jeong Woo, 42 

Parker, Beth Ann, 1 00 

Parmenter, Dana L, 42 

Parrish, Susan, 59 

Pepling, Melissa, 59 

Perez, Frank 73 76 

Perkins, Richard S., 7 

Persson, Enc, 62, 68, 69-70, 76 

Phillips, Mark, 1 7, 63, 66, 70-7 1 , 73, 76 



Pietruszka, Aaron J., 1 24 

Pike, William, 19, 100 

Polsenberg, Johanna, 42 

Praseuth, Richard, 1 00 

Press, Frank 7, 1 6 

Preston, George, 63, 69, 7 1 -72, 74, 76 

Prewitt, Charles T, 1 6, 8 1 , 95, 96-97, 1 00 

Prochaska, Jason, 62, 76 

Ramonell, Katrina, 42 

Randerson, Jim, 42 

Rauch, Michael, 1 7, 63 

Regan, Michael W., 1 24 

Rhee, Sue, 28 

Ribas-Carbo, Miguel, 42 

Richmond, Todd, 42 

Rillig, Matthias, 42 

Roth, Miguel, 1 3, 63, 72-73, 76 

Rubin, Vera C, 107-108, 124 

Rubinstein, Amy, 52, 59 

Rumble, Douglas, III, 82, 91, 97-98, 100, I 15 

Runkle, Matthew J, K„ 124 

Rutter, William J., 7, 1 8 

Sacks, I. Selwyn, 120, 121-122, 124 
Saghi-Szabo, Gotthard, 100 
Sakamoto, Koji, 42 
Sanchez Alvarado, Alejandro, 1 8, 46, 

55-56, 59 
Sancisi, Renzo, 1 24 
Sandage, Allan, 63, 76 
Scheible, Wolf Ruediger, 42 
Schiff, Celine, 42 
Schreiber, Alex, 59 
Schuenemann, Danja, 42 
Schweizer, Francois, 17, 106, 108-109, 124 
Schwoerer-Bohning, Markus, 100 
Scott, Bryan Wade, 1 00 
Seamans, Robert C, Jr., 7 
Searle, Leonard, 69, 76 
Sedbrook, John, 42 
Sharma, Anurag, 1 00 
Shaw, Rebecca, 42 

Shectman, Stephen, 67, 7 1 , 73-74, 76 
Shieh, Sean, 100 
Shirey, Steven B., I 19-120, 124 
Shujinfu, 100 
Sieber, Patrick 42 
Silver, Paul G, 90, 122-123, 124 
Singer, Maxine F„ 7, 18,93, 128 

President's commentary, 8- 1 5 

Publications of, 129 
Skibbens, Robert, 59 
Solomon, Sean C, 7, I 1 , 1 8, I 1 5- 1 1 7, 1 24 

Director's introduction, 1 05- 1 07 
Somayazulu, Maddury S„ 1 00 
Somerville, Chnstopher R, 7, 1 3, 38-40, 42 

Director's introduction, 27-28 
Somerville, Shauna C, 27, 28, 40-41 , 42 
Spradling, Allan C, 7, 11,56-57,59 

Director's introduction, 45-47 
Sprenger, Norbert, 42 
Stanton, Frank 7 
Steele, Kisha I., 1 24 
Stein, Monica, 42 
Stephens, Branson C, 1 24 



Still, Chris, 42 
Stolbov, Sergei, 88 
Stone, Christopher T S., 7 
Storrie-Lombardi, Lisa, 75, 76 
Struzhkin, Viktor, 98-99, 1 00 
Sun, Xing, 59 
Sutin, Brian, 76 
Swensen, David F., 7 

Teece, Mark A, 1 00 
Tera, Fouad, 124 
Thayer, Susan S., 42 
Thomas, James, 1 6, 
Thompson, Ian, 69, 7 1 , 74, 76 
Timmons, Lisa, 59 
Tomascak, Paul B„ 124 
Torn, Margaret, 42 
Townes, Charles H., 7, 1 8 
Trager, Scott 62, 76 
Tu, Chao-Jung, 42 
Tulin, Alexei, 59 
Turner, William I. M., Jr., 7 

Urban, Thomas N., 7 

van Waasbergen, Lori, 42 
Vanhala, Harri A. T, 124 
Villand, Per, 42 
Virgo, David, 99, 100 
Vogel, John, 40, 42 

Wang, Jianhua, 85, 115 

Wang, Xin, 42 

Wang, Zengfeng, 59 

Warren, Rudy, 16,27,42 

Wasserman, Abigail, 1 00 

Webb, Susan J., 1 24 

Weinberg, Sidney J., Jr., 7, 16 

Weiner, Ben, 76 

Wells, Aida, 16,27,42 

Welsh, Brian, 17,27,42 

Wen, Lianxing, 1 24 

Wetherill, George W., 14, I 13-1 14, 124 

Weymann, Ray, 75, 76 

Wheeler, Kevin, 100 

White, Sue, 25, 128 

Wiechert, Uwe, 1 00 

Wiese, Christiane, 59 

Wilde, Andrew, 59 

Wilson, lain, 42 

Wu, Shu-Hsing, 42 

Wu, Zheng'an, 59 

Wykoff, Dennis, 37, 42 

Xie, Ting, 59 
Xu,Ji-an, 100 

Yan, Lin, 68, 76 

Yang, Hexiong, 96, 100 

Yoder, Hatten S.Jr., 83, 92, 94-95, 100 

Zavala, Karina, 1 24 
Zavaleta, Erika, 42 
Zheng, Yixian, 19,57-58,59 
Ziegler, Susan, 100 
Zimmerman, Sarah B., 1 24 






A GIFT FOR THE FUTURE OF THE 



CAR 



OF WASHINGTON 




One of the most effective ways of supporting the work of the Carnegie 
Institution of Washington is to include the institution in your estate 
plans. By making a bequest, you can support the institution well into the 
future. 

A bequest is both a tangible device of your dedication to the Carnegie 
Institution and a way to generate significant tax savings for your estate. 
Some bequests to the institution have been directed to fellowships, 
chairs, and departmental research projects; some have been additions to 
the endowment; other bequests have been unrestricted. 

The following sample language can be used in making a bequest to the 
Carnegie Institution: 

"I give, and bequeath the sum of $ (or % of my residuary estate) to 

the Carnegie Institution of Washington, 1530 P Street, N.W., 
Washington, DC 20005-1910." 

For additional information, please call Susanne Garvey, Director of 
External Affairs, at 202.939.1128, or write: 



Susanne Garvey 
Directory External Affairs 



CARNEGIE I 



1530 P Street, N.W. 
Washington, DC 20005-1910 





CARNEGIE INSTITUTION 



OF WAS H I N GTO N 



1530 P Street, NW 
Washington, DC 20005