VIRGINIA JOURNAL OF SCIENCE OFFICIAL PUBLICATION OF THE VIRGINIA ACADEMY OF SCIENCE Vol. 63 No. 1 & 2 Spring/Summer 2012 TABLE OF CONTENTS ARTICLES PAGE Effect of Greenhouse Temperature on Tomato Yield and Ripening. Mark E. Kraemer, Christopher D. Mullins, and Carl E. Niedziela Jr. 3 Proceedings of the 90th Annual Meeting Virginia Academy of Science Norfolk State University, Norfolk Virginia May 23-25,2012 SECTION ABSTRACTS Aeronautical and Aerospace Sciences 15 Astronomy, Mathematics and Physics &Materials Science 16 Biology 20 Microbiology & Molecular Biology 28 Biomedical and General Engineering 39 Botany 43 Chemistry 47 Computer Science 52 Education 52 Environmental Science 54 Medical Science 57 Natural History & Biodiversity 68 Psychology 74 Structural Biology, Biochemistry and Biophysics 76 NECROLOGY Ertle Thompson - 1929 - 2012 87 Virginia Journal of Science Volume 63, Number 1 & 2 Spring & Summer, 2012 Effect of Greenhouse Temperature on Tomato Yield and Ripening Mark E. Kraemer \ Agricultural Research Station, Virginia State University, Petersburg, VA 23806, Christopher D. Mullins, Virginia State University Cooperative Extension, Virginia State University, Petersburg, VA 23806, and Carl E. Niedziela Jr., Natural Sciences and Mathematics, Ferrum College, Ferrum, VA 24088-1000 ABSTRACT High fuel costs have encouraged producers of greenhouse tomato {Solarium lycopersicum L.) in the mid-Atlantic region to reduce air temperatures during the day. However, effects on fruit ripening and yield are not known, especially under the low hght conditions found in off-season production. This 2-yr study compai'ed fruit ripening and yield of tomato under two temperature regimes during the fall season. Two sets of 18 tomato plants, three rows of six, were grown in soilless culture under either a warm or cool temperature regime. Temperatures were similar during night hours but allowed to rise to at least 21- 24 °C in the cool greenhouse section and 23-26 °C in the warm section, depending on daily solar heating. Mean 24 hour temperature difference between zones was less than 2 °C. Ripe tomato fruit were harvested and weighed 3 times per week for 8 weeks and the remaining un-ripened green tomatoes were weighed at the termination of the experiment to obtain total fruit biomass. The warm zone produced significantly greater weight of ripe tomatoes (23%) than the cool zone. However, total fruit weight (ripe and green), was not significantly different. Thus, a relatively small increase in temperature (2 °C) during the mid-day was associated with a significant increase in fmit ripening but not in total tmit weight. This study showed that greenhouse temperature could be used to better manage fruit production to match weekly mai'ket demand without affecting total fruit weight and that consistently maintaining a cool greenhouse would delay tomato ripening and likely increase the potential for plant stress due to high fruit loads remaining on the vines. Keywords: Solarium lycopersicum, soilless culture, PAR, solar radiation INTRODUCTION Greenhouse tomato {Solarium lycopersicum L.) production is an important source of income for limited-resource producers in the mid-Atlantic region of the U.S. ^ Corresponding author. Email address: mkraemer@vsu.edu Use of trade names does not imply endorsement by the VSU-ARS of products named nor criticism of similar ones not mentioned. 4 VIRGINIA JOURNAL OF SCIENCE Tomato seeds are usually planted in the late fall and harvested in late winter through the early summer. These vine-ripened tomato fruits are often produced without the use of pesticides and marketed locally at a premium to restaurants, food retailers, and through farmer’s mai’kets. Higher energy costs during the last decade encouraged some producers to lower greenhouse day temperatures several degrees, but without knowledge of the effects of these changes on fruit ripening and yield. From work done in Quebec, Canada, Dalton (2003, 2005) recommended that day temperatures during seasons with low light intensity be set from 19 and 21 °C, depending on the level of light intensity. Night temperatures were recommended to be 17 to 18 °C. Cooler temperatures may affect flowering, fruit set, and fruit weight (Ercan and Vural 1994). Prior to these recommendations, many mid-Atlantic region growers had been using day temperatures several degrees higher. Both early production and high energy efficiency have been noted as important factors in greenhouse vegetable production (Zhang et al. 2010) and lowering greenhouse temperatures can save significant amounts of energy (Flings et al. 2005). Heating costs are often second only to labor costs and increases in fuel prices have created interest in maintaining the lowest possible temperature without harming fruit yields and early harvest. Cooler greenhouse temperatures can also be used to reduce plant stress during periods of low light intensity; such as short day lengths in the winter and prolonged periods of overcast weather (Dalton 2003). However, warmer temperatures result in more rapid fruit ripening (Adams et al. 2001) and are recommended for greenhouse producers if plant vigor is good and light intensity is sufficient to support the existing fruit load (Dalton 2003). Optimal greenhouse temperature for tomato production in the mid-Atlantic region has not been established. Thus, producers rely on models developed for higher latitudes, the Netherlands and Canada. The ability of greenhouse tomato cultivars to utilize available photosynthetically active radiation (PAR) has greatly increased in recent decades. Greenhouse tomato yields in the Netherlands have doubled since the 1950’s due to increased photosynthesis rates and changes in plant architecture that decreased the Ught extinction coefficient (Higashide and Heuvelink 2009). A preliminaiy study of photo.synthesis rates of tomato leaves (cultivar ‘Tmst’) in a commercial Virginia greenhouse indicated lower temperatures (18 C vs. 23 C) would not greatly reduce CO 2 fixation rates at light intensities typically available in the greenhouse during fall and winter (400 PAR). There was no difference in CO 2 fixation rates at light intensities typically found during overcast winter days (50-100 PAR) (Kraemer, unpublished data). This indicated that lower greenhouse temperatures could potentially be used to reduce energy costs. The cuiTent study was initiated to compare fruit yield and ripening of tomato fruit grown in a greenhouse under two temperature regimes during tlie fall season. Night temperatures were the same in both treatments but maximum daytime temperatures differed by about 2 °C. The experiment was conducted over two years, during the fall when natural light intensities were low. The results are most applicable to tomato growers in latitudes similar to the mid-Atlantic region of the U.S. and will allow these producers to better optimize their energy resources. MATERIALS AND METHODS The glass A-frame greenhouse (Rough Brothers, Cincinnati, OH) used in this study was located at the Randolph Farm of Virginia State University near Ettrick, VA at 37° EFFECTS OF TEMPERATURE ON TOMATO 5 14' north latitude. The greenhouse had side vents, an evaporative cooling system at the intake vents, and hot-water radiator heating along the walls at roof and floor. The greenhouse contained 4 sections (6 x 15 m) that were separated by glass walls and had individual environmental controls (Growmaster Procom, Micro Grow Greenhouse Systems, Inc., Temecula, CA). The sections were aligned on an east-west axis, with the two outer sections (east and west) used in this study. Because there was a potential difference between sections in direct exposure to morning and afternoon solar radiation, the experiment was repeated a second year with the locations of the warm & cool sections reversed. In 2009, the east greenhouse section was selected as the cool zone; whereas in 2010, it was the warm zone. Each greenhouse zone had a HOBO® Micro Station equipped with an 8-bit Temperature Smart Sensor and a Photosynthetically Active Radiation Smart Sensor (Onset Computer, Pocasset, MA). Photosynthetically Active Radiation (PAR) was measured in units of photons (pmol m'" sec '). The temperature probes were shielded from dkect sunlight and placed 4 feet off the concrete floor whereas the light sensors were horizontally leveled and placed 8 feet above the floor. Three time intervals for temperature were used to allow for slower temperature increases from cool nights. Minimum and maximum night teiuperatures (sunset to sunrise) were set at 17 and 19 °C, respectively, in both the warm and cool greenhouse zones. Morning temperatures (sunrise to 11 AM) were set at 18 and 20 °C in the cool zone and 19 and 22 °C in the warm zone. Mid-day temperatures (11 AM to sunset) were set at 21 and 24 "C in the cool zone and 23 and 26 °C in the warm zone. Actual temperatures in the greenhouse were dependent upon solar intensity and outside ak temperature, with temperatures at the lower end of the range during cooler and overcast weather. Seeds of tomato cultivar ‘Trust’ were sown on July 15^’^ in both years and maintained in a climate controlled greenhouse with temperature set to 24 °C. Tomato transplants were set into 6-inch-diameter (15 cm) plastic pots with coconut fiber media (Fiber Dust, LLC, Glastonbury, CT) and maintained until late August. They were then moved to the experimental greenhouse, divided into two equal groups of 18, and each transplanted into 5 gal (19 L) black plastic bags containing coconut fiber (EZ Gro Bags, Hydro-Gardens, Colorado Springs, CO), The plants were arranged in three rows of six plants in each of the two greenhouse temperature zones. Bags were spaced 0.7 m apart within the row and rows were spaced 1.5 m apart. Drip in'igation of individual bags was controlled by an Orbit 4-Station Programmable Timer, model 57114 (Orbit Inigation Products, Inc., Bountiful, UT) connected to a dual injector drip iiTigation system. The injectors (DI 16; Dosatron International, Inc., Clearwater, EL) were each set to 1:100 injection ratios of two nutrient solutions: 1) 368 g of 5N-11P-26K fertilizer (Peters Professional soluble, Peters Chemical Company, Hawthorne, NJ) with micronutrients and 36.8 g magnesium sulfate per gallon, and 2) 244 g calcium nitrate and 42 g potassium nitrate per gallon. Plants were drip irrigated four times daily until leaching from the bags was observed. Tomato plants were grown as vines, attached by clips to polyester twine hanging down from an upper support beam. Side shoots were removed weekly to maintain a single vine and the twine was lowered as the plants grew. Leaves below the last tmss were also removed and flowers were pollinated three times per week with an electric pollinator. Trusses were pruned to a maximum of five fruit. Ripe tomato fruit were 6 VIRGINIA JOURNAL OF SCIENCE TABLE 1. Mean light intensity (PAR) in west and east greenhouse sections in years 2009 and 2010 (1 Sept. - 5 Dec.). 2009 2010 Time Period West East West East 12:00 AM - 4:00 AM 1 1 1 1 4:00 AM - 8:00 AM 21 22 29 36 8:00 AM - 12:00 PM 362 358 394 409 12:00 PM - 4:00 PM 359 346 446 408 4:00 PM - 8:00 PM 49 32 21 23 8:00 PM - 12:00 AM 1 1 1 1 24-h Mean 132 127 149 146 harvested three times weekly for eight weeks, from October until early December. Tomato fruit were weighed in the greenhouse at the time of harvest. The number and weight of ripe tomato fmit, weight of green tomato fmit, and total fruit weight were compared between temperature treatments. Each of the three rows of tomato plants within a greenhouse temperature zone was treated as a replicate. Individual year and combined two-year data were analyzed using one-way analysis of variance (ANOVA) with means separated at P< 0.05 by t test, (PROC ANOVA, SAS Institute, 2009). Simple linear regression analysis was used to evaluate relationships between environmental parameters and yields over the 8 weeks of fruit harvest (PROC REG, SAS Institute, 2009). RESUETS Mean light intensity was similar in the two temperature zones in both years although zone 1 (west side) had slightly greater (3%) mean Photosynthetically Active Radiation (PAR) than zone 4 (east side) (Table 1). This difference was largely due to the western zone receiving more direct sunlight than the eastern zone in the late afternoon. Conversely, early morning sunlight was often more diffused because of higher humidity and fog. The temporal difference in light intensity between the zones created a small asymmeti-y, because morning mean temperatures in both zones were lower than afternoon temperatures. Thus, the zones assigned to temperature treatments were alternated the second year. Weekly mean light intensity (24-h) is provided in Tables 2 and 3 for the 8 weeks during which fruit were harvested in 2009 and 2010, respectively. Mean weekly PAR values ranged from 83 to 173 and were affected by both overcast weather and shortening day length. Daily mean values during this 8- week period ranged from 33 to 244 PAR, Air temperature was greatest during the afternoon hours in both zones, as were the EFFECTS OF TEMPERATURE ON TOMATO 7 temperature differences between zones, about 2 (Fig. 1). Zone temperatures were similar during the night hours, 8:00 PM to 8:00 am. In the first year, zone 1 (warm) had a slightly warmer (0.5 °C) night temperature due to initial differences in the calibration of the temperature sensors. Mean night temperatures during the second year were within 0.05 °C. Mean overall temperatures were slightly cooler (1 °C) during the second yeai* due to generally cooler weather conditions. Overhead shade cloth was not used and inside temperatures sometimes increa.sed beyond the cooling set points on sunny warm days, to a maximum of 29 ®C. Mean 24-h temperature was 1.5 °C and 1.2 C higher in the wann zone than the cool zone in 2009 and 2010, respectively (Tables 2 and 3). Tomato fruit were harvested for 8 weeks, from October 11 to Dec 05 in 2009 and from October 17 until December 10 in 2010 (Tables 2 & 3). The first harvest of ripe fruit was about a week later in 2010 than in 2009, accounting for the slightly later termination date in 2010. Ripe tomato yield increased to a maximum in the 3*^^ or 4“’ week. coiTesponding to the fir st week of November in both years. The tomato plants were fully developed by this time with each vine having 7 ti'usses. From this time onwards the weekly ripe fruit weight harvested was significantly correlated with mean weekly PAR (r= 0.25, df = 17, F = 5.3, P < 0.035). The mean weekly PAR varied with atmospheric conditions but tended to decrease throughout the 8-wk harvest at a rate of 6.6 PAR per week (F = 26, df = 31, r = 0.46, P < 0.001) as was expected from shortening days. Total ripe tomato fruit weight was significantly greater in the warmer than the cooler zone in both 2009 (F = 17.3; df = 1,5; P < 0.009) and in 2010 (F = 10.5; df = 1,5; P < 0.032),(Tables 4 & 5). Combined analysis of both 2009 and 2010 showed no significant interactions or year effects. Total ripe fruit weight was significantly greater (23%) in the warmer zone (F = 19.0; df = 2,8; P < 0.049) (Table 6). The mean weight of ripe tomato fruits was slightly greater (4%) in the warm zone (Table 6) although this difference was not significant in either year. Thus, the difference in total harvest weight of ripe tomato fruits was largely due to the 19% greater number of tomato harvested in the warm zone rather than a difference in individual fmit weight. In contrast to the yield of ripe tomato fruit, the total weight of green tomato fruit remaining on the vine at the conclusion of the experiment was significantly greater (17 %) in the cool zone in the first year (F = 21,6; df = 1,5; P < 0.01) (Table 4) and greater (8 %), though not significantly so, in the second year (Table 5). The combined weight of ripe and green fruit was not significantly different between zones in either year. Total fruit weight (ripe and green) over two yeai's was only slightly greater (1 %) in the warm zone than the cool zone (Table 6). Small differences in light intensity between the two greenhouse sections may have been responsible for a slight difference in total tomato fruit weight between the two sections. Over the two-year period, the greenhouse section with the more direct afternoon sun (zone 1) had a slightly higher mean total fruit weight, 39.3 kg vs. 38.9 kg (Table 6). However, there were no significant year effects on yield or other parameters. DISCUSSION Tomato requires a minimum amount of solar radiation to maintain plant vigor. Dalton (2003) estimated that it takes about 100-125 joules per cm'^ of energy per day for each truss of tomatoes on a vine, and an additional 100-125 joules cm'^ per day for general plant maintenance. He estimated that it requires an average of more than 5600 8 VIRGINIA JOURNAL OF SCIENCE FIGURE 1. Mean temperatures ( C) in west and east greenhouse sections during 4 h periods in year 2009 (A) and in year 2010 (B). to 7000 joules per cm^ solar energy per week to maintain a tomato plant with 7 trusses and that in Quebec this could be expected from the middle of March on. More southern latitudes could be expected to have greater amounts of solar energy during the fall and EFFECTS OF TEMPERATURE ON TOMATO 9 Oh ^ (N 00 (N cn ^ gQ' ONOCTNOor-’odr^odod H ^ j^Q:; ooin(NoocnON(Ncnin ox)'q-< —i'^OO^o^oooo^O ^ ^ ^ ^ ^ 8 g c /5 C 3 ^moo^oooo^mo^ O o U CT\0>m^O'^m(N^ cr;»nincn'Ornooir)r^_ O cn cn 'vd iri 'ct r^mt^ooo^OooTt m^'^cNmcNi^cN r^i^r^oqcr\rnr^p^_ O^’^’OOOCTnOOCTvO (N(N(N(N'-h^--ht-<(N bn^ oo'0'Ocnmoo(N'^0 o ^ 0^ 00 o o CU r- !/D H I > ^ C/5 ^ '^'^■^»00^0^(NCN^ mm'oa\aN(N(Nir)aN , 0) o Q T3 ^ lo ' ^ u ^ O E5- ON . O (N O w < ^ H .S +3 ooinND^ON'sOcn'om (N (N cn >n CO IT) p '-H iri (N NO ON NO 'CfNOCOCOONONOOO m(NNO(N^(Nmcn (Nco^inNor^oo o 10 VIRGINIA JOURNAL OF SCIENCE S u 0) o '^OO'^r^OO^OOONCO O^OooooOnOnooooO^ Q tiSi ^ 'Om(Nir)^Ooooo(N hJ tH t/3 « G S =3 I S 0^ in On m m o OOOO'^00(N^ (N (N (N (N (N (N (N (N '^00^'—^(Nlnln^oo G5 o ^ ^ "O 00 00 (N (N (N ^ T^’ O ON 'O MD ^ 'O oooeNNOOr-oo^ON (Nin^(Nm(N(N(N a u (U o H ^ O 00 (N rn 00 ON r~^ONo6r^o6o6r^r^od S ce; miNcnm'^r^NO'-HNO ^ NO m (N r- (N o ON ON (N i_] ^ ^ ^ ^ ^ ^ ^ 05 e3 ^ OJ Q o o T3 --N lo ' • ♦ ^ o ^ O r- o--HOr^Ndcn^'Ndin O '^ON'^OO^ON^OONO ^ mmm^(N(N(N ^ o ^(Ncn^inNor^oo EFFECTS OF TEMPERATURE ON TOMATO 11 TABLE 4. Tomato fmit yield under wai*m (east section) and cool (west section) greenhouse temperature regimes in 2009. ___ Treatment No. ripe Fruit Mean ripe wt (g) Total ripe wt (kg) Total green wt (kg) Total fruit wt (kg) Warm 81 198 16.1 23.3 39.4 Cool 65 194 12.7 27.2 39.8 Significance® NS NS ** * NS NS, *, or ** indicates nonsignificant, significant at P<0.05, or significant at P<0.01, respectively, by F test. TABLE 5. Tomato fmit yield under warm (west section) and cool (east section) greenhouse temperature regimes in 2010. ___ Treatment No. ripe Fruit Mean ripe wt (g) Total ripe wt (kg) Total green wt(kg) Total fruit wt (kg) Warm 79 213 16.9 22.3 39.2 Cool 68 205 13.9 24.1 38.0 Significance® NS NS * NS NS NS or * indicates nonsignificant or significant at P<0.05, respectively, by F test. TABLE 6. Mean tomato yield under warm and cool greenhouse temperature regimes over two years (2009 & 2010). Treatment No. ripe Fruit Mean ripe wt (g) Total ripe wt (kg) Total green wt (kg) Total fruit wt (kg) Warm 80 205 16.4 22.8 39.3 Cool 66 200 13.3 25.6 38.9 Significance® NS NS * NS NS NS or * indicates nonsignificant or significant at P<0.05, respectively, by F test. 12 VIRGINIA JOURNAL OF SCIENCE winter months. However, periods of overcast weather can greatly reduce the amount of solar energy available to plants as shown in the degree of variation in weekly mean PAR (Tables 2 & 3) and range of 24-h mean PAR (33 to 244). There is no direct conversion of radiometric light energy units (joules) to quantum PAR units because not all wavelengths are used for photosynthesis and the spectrum of solar radiation varies with the time of day (sun angle) and atmospheric conditions. However, a general conversion factor for solar radiation was developed for atmospheric measurements by Ting andGiacomelli (1987). Using this conversion (2.07 pmol-.s'^-nT^ per joule-m'^), none of the weekly mean PAR levels in the current study (Tables 2 & 3) reached the minimum light requirements of Dalton (2003) for full tomato production, 5600 to 7000joules per cnr, although some days exceeded the minimum. Weekly solar energy during fruit production ranged from a low of 2425 joules (83 PAR) to a high of 5055 joules (173 PAR) per cm“ per week. However, the tomato plants did not appear to be under stress and continued to produce a new set of flowers each week. Blossom drop was not a problem. This could be because plant density (0.8 plants/nr) was much less than that used in most commercial greenhouses (2 plants/m‘) and thus plants were more exposed to the available light in this study. The wider spacing was used to eliminate possible stress effects from overcrowding and ensure equal sunexposure for all plants within a treatment. There was a significantly greater total weight of harvested ripe fruit in the warm than the cool greenhouse zone. This agrees with Adams et al., 2001, who showed that the rate of tomato fruit ripening was positively related to higher temperatures, up to at least 26 °C. The nearly equal weight of total fruit production (ripe and green) between temperature treatments indicates that the tomato cultivar ‘Tmst’ can be grown at slightly lower daytime temperatures without a significant loss of fruit production, although ripening may be delayed. Dalton (2003) recommended that growers reduce daytime greenhouse temperatures by a few °C during periods of low light intensity to reduce stress on plants, prevent loss of vigor, and maintain a balance between the vegetative and generative conditions. However, the present study showed that extended use of cooler temperatures would result in delayed ripening and increased stress on plants from increased fruit load. Dalton (2003) recommended setting greenhouse temperatures according to the amount of solar radiation available and the degree of plant vigor, i.e,, higher temperatures during sunny days and when plants were too vigorous.. He stated that plants that were too vigorous had greater vegetative than generative growth and that warmer temperatures and higher light levels decreased vegetative growth and increased generative growth. The objective was to obtain a balance between vegetative and generative growth. De Koning (1989) also found that tomato plants shift assimilate partitioning from vegetative towai'ds fruit growth with higher temperatures. That the results of the present study did not show a significant difference in total fruit weight (generative growth) between treatments may be related to the relatively small differences in temperatures in our study. Temperature treatments in the De Koning study differed by 6 °C (17 to 23 °C) whereas the difference in mean 24-h temperature between our treatments was only about 1 C over 24-h, and at most 2 °C during mid-day. In addition, De Koning used constant temperatures whereas temperatures varied in the current study, as is commonly found in commercial greenhouses. The longer day and more direct solar radiation during fall and winter in the mid- Atlantic region of the U.S. may allow for a longer growing season and/or the use of EFFECTS OF TEMPERATURE ON TOMATO 13 higher temperatures than those recommended for use in greenhouses at higher latitudes, such as those in Quebec and the Netherlands, However, periods of overcast weather during fall and winter in the Mid-Atlantic region often reduce light intensity to below that recommended for full production. Greater spacing of plants within the greenhouse would likely allow plants to better utilize the available hght during these periods and reduce stress. The mean rate of ripe fruit production (g/plant/day) in tliis study was greater in both the wami (142 g) and cool (118 g) greenhouse treatments than that of a local commercial greenhouse (102 g) using the same cultivar during a similar period of time (March-April) but at a higher mean plant density of 2 plants/nr (unpublished data, 2008-2010). Thus, the very low plant density used in this study (1 plant/m^) would likely reduce greenhouse tomato yield and is not recommended. Avoiding plant stress can be as important as increasing yields. To do this, growers often reduce daytime temperatures by several degrees during periods of prolonged overcast weather, similar to the cool temperatures used in this study. However, the results of this study indicate that keeping greenhouses at cooler temperatures to save on heating costs would significantly delay fruit ripening and increase fruit load on vines. Daytime greenhouse temperatures should be set according to the amount of solar radiation available. Fmit ripening would be enhanced by allowing greenhouses to warm on days with high light intensity, to 24 °C or more, by reducing venting, and/or adding supplemental heating. Reduced venting would also allow greater use of CO 2 generators. This study shows that relatively small changes in daytime greenhouse temperature will allow growers to significantly modify fruit ripening and thus better match weekly tomato production with market demand. ACKNOWLEDGMENTS The authors would like to thank Darlene and Jeny Taylor for providing weekly yield data for their Dogwood Grove Greenhouse over multiple years, and permitting photosynthetic measurements during several growing seasons. Mr. Christopher Mullins was instrumental in setting up the automated irrigation system used in this study and providing the expertise in tomato growing. Dr. Cai'l Niedziela provided statistical analysis and horticultural data interpretation. LITERATURE CITED Adams,, S.R., K.E. Cockshull and C.R.J. Cave, 2001. Effect of Temperature on the Growth and Development of Tomato Emits. Annals of Botany, 88:869-877. Dalton, C. 2003. Practical Measurements to help greenhouse tomato growers read the productivity of their plants. Tom Pousse, week 15, April 17“^. Quebec Department of Agriculture, Canada. Dalton, C. 2005. Reading the Plants. Annual Conference of the North Carolina Greenhouse Vegetable Growers Association, October 25, North Carolina Cooperative Extension, Wake County Agricultural Services Center, Raleigh, NC. Elings A, F.L.K. Kempkes, R.C. Kaarsemaker, M.N.A. Ruijs, N.J. van de Braak, and T.A. Dueck, 2005. The energy balance and energy-saving measures in greenhouse tomato cultivation. Acta Horticulturae, 691:67-74. Ercan, N. and H. Vural 1994. The Effects of Low Temperatures on Fruit Set of Tomatoes. Acta Horticulturae 366: 65-72. Higashide, T, and E. Heuvelink, 2009. Physiological and Morphological Changes over 14 VIRGINIA JOURNAL OF SCIENCE the Past 50 Years in Yield Components in Tomato. Journal of the American Society for Horticultural Science, 134(4):460-465. 2009. De Koning, A.N.M. 1989. The Effect of Temperature on Fruit Growth and Fruit Foad of Tomato. Acta Horticulturae, 248: 329-336. SAS Institute, 2009. SAS user’s guide, Version 9.2. SAS Institute, Cary, NC. Ting, K.C., G.A. Giacomelli, 1987. Availability of Solar Photosynthetically Active Radiation. Transactions of the ASAE, 39: 1453-1457. Zhang, F., X. Hao, Y. Fi and G. Jiang, 2010. Response of Greenhouse Tomato to Varied Fow Pre-night Temperatures at the Same Daily Integrated Temperature. HortScience, 45(11): 1654-1661. 2010. PROCEEDINGS 90“^ ANNUAL MEETING 15 Proceedings of the 90th Annual Meeting Virginia Academy of Science Norfolk State University, Norfolk Virginia May 23-25, 2012 Aeronautical and Aerospace Sciences A HYBRID AIRSHIP CONCEPT M. Lerov Spearman Langley Research Center, Hampton, VA. An airship differs from an airplane in that the 1 ift required for flight is provided by a lighter-than-air gas contained withm the airship hull. For an airplane the lift required for flight is generated by moving air over an airfoil shaped wing. The lift for an airship is called buoyant lift and it requires no forward motion. The lift for an airplane is called kinetic lift and requires forward movement of the vehicle through the air to produce the lift. A large airship is capable of lifting very heavy loads but is limited in speed and range. A hybrid airship is one in which buoyant lift is combined with kinetic lift. The proposed concept would be a twin-hull airship with a connecting inboard wing. The use of twin hulls would provide the required amount of lighter-than- air gas to be contained in a length half that of a single hull. let engines would be attached to the wing to provide for the foi'ward flight that would create the kinetic lift. Particular designs can be developed by manipulating such factors as the volume of gas, the wing area, the airfoil contour and the engine thrust. Designs could be made that varied from small, lightweight systems to very large, heavy-load systems. Such a vehicle would also pemiit access to almost any remote location because of the vertical landing and take-off capability provided by buoyancy. Such a vehicle would be suitable for militaiy'' logistic support missions. In commercial use the vehicle could serve small airports, could reduce community noise, could relieve air traffic delays, and could improve fuel efficiency. SOME LESSONS LEARNED WITH NACA/NASA WIND TLTNNELS , M. Lerov Spearman. Langley Research Center, Hampton, VA & Robert W, Heath, Canon of Virginia, Newport News, VA. The N ASA Langley Research Center in Hampton, VA has been engaged in improving our nations aircraft for over 92 years. Named after aviation pioneer, Samuel Pierpont Langley, the Langley Memorial Aeronautical Laboratory was the first laboratory of the National Advisory Committee on Aeronautics (NACA). When the first of many wind tunnels went into operation at Langley in the early 1920’s the typical aircraft was a low-speed, propeller-driven airplane Early research at Langley led to airfoil shapes that maximized the lift and minimized the drag. Other drag reduction led to the development of engine cowling for propeller-driven airplanes, the covering of the open cockpit, the cantilevered monoplane wing, and the retractable landing gear. When jet-propulsion was developed for aircraft the aerodynamic research was extended to transonic, supersonic and hypersonic speeds. New teclmiques and new wind tunnels were developed at Langley to address the problems at speeds beyond the speed of sound. One of the models tested at Langley, the Bell XS-1, was the first airplane to fly through the sound barrier. Essentially every supersonic aircraft built in the US has been influenced by Langley wind tunnel results. 16 VIRGINIA JOURNAL OF SCIENCE When further results lead to shapes that permitted access to space the NACA was replaced by the National Aeronautics and Space Administration (NASA) and research related to both aircraft and spacecraft continues at tlie Langley Research Center. VARIABLE GEOMETRY AIRCRAFT. M. Leroy Spearman. NASA-Langley Research Center. Hampton, VA. A given aircraft design is generally a fixed shape tliat fits the mission requirement and different requirements require different shapes. Since the early days of manned flight aircraft have generally had a lift-producing wing that was aligned normal to the airstream direction. As the air moves over the wing surface the air begins to compress and with increased speed a point is reached where the air cannot be moved any further and increased flight speed is not possible. By sweeping the leading edge of the wing back at an angle to the flight direction the air flow over the wing travels a greater distance from the wing leading edge to the trailing edge and this apparent slimming delayed the onset of compressibility. While swept wing designs did permit high speeds they had poor stability at low speeds that required translating the wing fore and aft as the sweep angle was changed. NASA Langley resolved the problem with a design in which only a portion of tlie wing was swept. This lead to the concept that a wing with variable sweep could combine the speed advantage of high sweep with the good stability characteristics of low sweep. In 1961 the U.S. Secretary of Defense, Robert McNamara initiated the Transonic Experimental Fighter (TFX) program to develop a common airframe suitable for the Navy and the Air Force. The General Dynamics F-111 airplane was produced that met the mission requirements but the Navy cancelled out because the airplane exceeded weight and size limits imposed by aircraft carriers. Other airplanes that have made use of variable sweep in the U.S. are the Navy Grumman F-14 and the Air Force Rockwell B-1. Astronomy, Mathematics and Physics / Materials Science AN INEXPENSIVE RADIO TELESCOPE IN A COLLEGE PHYSICS LAB. T C. Mo sea III . Dept, of Mathematics & C, Crook Dept, of Chemistry and Physics, Rappaliannock Community College. An amateur radio telescope was established on the Glenns campus of Rappahannock Community College. The components included a commercial amateur radio receiver, an antenna designed to operate in the 15-30 MHz range, and a laptop computer running a freely available software package. Data were collected in 24-hour increments at 20.100 MHz, which is a frequency reserved for radiotelescopy. N umerous events were recorded, several of which were simultaneously observed at sites up to 3000 km away, indicating that these events originated from extraterrestrial sources. Physics students experienced a tangible application of electromagnetism principles, and learned that extraterrestrial objects are radio emitters. They also learned that real and valid research can be conducted without sophisticated and expensive equipment. In the future, we hope that students can be more directly involved in the collection and analysis of data, and that data can possibly be collected from sources otlrer than our sun. The Accelerating Jet of 3C 279. S. D. Bloom*, C. M. Fromm^, and E. Ros^ ’Department of Physics & Astronomy, Hampden-Sydney College, “Max Planck PROCEEDINGS 90**^ ANNUAL MEETING 17 Institute for Radio Astronomy, ^University of Valencia. Analysis of the proper motions of the sub-parsec scale jet of the quasar 3C 279 at 15 GHz with the VLBA shows significant accelerations in four of nine superluminal features. Analysis of these motions is combined with the analysis of flux density light curves to constrain values of Lorentz factor and viewmg angle (and their derivatives) for each component. The data for each of these components is consistent with no changes to tlie Lorentz factor, but significant changes to the viewing angle and azimuthal angle, suggesting Jet bending with minimal changes in speed. We see that for these observed components Lorentz factors are in the range of 10'^'’, and for viewing angles of 0.1°-4.6°, and intrinsic (source frame) flux density, F=(7 x 10'*^ -1.6 x 10“^) Jy. Considering individual components, the viewing angles vary in time from 1.2 to 1.4 in the case of C1 (the least extreme example) and vaiy from 0.06° to 1.4° in the case of C6 (the most extreme example). The intrinsic flux density varies by factors from 1.6 for C8 and 240 for C5. Theoretical analysis of the accelerations also indicates potential Jet bending. In addition, for one component, C5, polarization measurements also set limits to the trajectory of tire Jet. FORMATION OF RELATIVISTIC OUTFLOWS IN ADAF DISKS WITH SHOCKS. Truong V. Lef Cassandra Brown', Peter A. Becker^, and Santabra Das^, ‘Dept, of Physics, Governor’s School for Science and Technology, ^School of Physics, Astronomy & Computational Science, George Mason University, and^Dept. of Physics & Astronomy, Indian Institute of Technology Guwahati, India. We have developed a new self-consistent theory for the production of the relativistic outflows observed from radio-loud black hole candidates and active galaxies as a result of particle acceleration in hot, inviscid accretion disks contaming standing, centrifugally supported isotliermal shocks. Utilizing tliis model, we estimate the Jet locations of 13 low-power radio-loud AGNs using the associated observed Jet powers and their inferred mass accretions. Our results suggest that there is a direct correlation between the Jet power and the Bondi accretion power, and that the Jets location increases further away from the event horizon as the mass accretion rates and Jets powers increases. ON THE REDSHIFT DISTRIBUTION OF GAMMA RAY BURSTS IN THE SWIFT ERA. Truong V. Le' and Charles Dermer^, ‘Dept, of Physics, Governor’s School for Science and Technology, and'E. O. Hulbuit Center for Space Research Naval Research Eaboratory. A simple physical model for long-duration gamma ray bursts (GRBs) is used to fit tlie redshift (z) and the Jet opening-angle distributions measured with earlier GRB missions and witli Swift. The effect of different sensitivities for GRB triggering is sufficient to explain the difference in tire z distributions of the pre-Swift and Swift samples, with mean redshifts of ~= 1.5 and ~= 2.7, respectively. Assuming that the emission properties of GRBs do not change with time, we find that the data can only be fitted if the comoving rate-density of GRB sources exhibits positive evolution to z ~ 3 - 5. SEARCHING FOR INTERMEDIATE MASS BEACK HOEES WITH X-RAYS. Insuk Jang' . Mario Gliozzi', Eev Titarchuk' & Shobita Satyapal', ‘School of Physics, Astronomy, and Computational Data Science, George Mason Univ., Fairfax VA. 22030. The black hole mass is a crucial parameter to shed light on the physics of 18 VIRGINIA JOURNAL OF SCIENCE accretion. While the presence of stellar mass black holes (sMBHs) in binary systems and supermassive black holes (SMBHs) in the center of galaxies is widely accepted, the veiy existence of intermediate mass black holes (IMBHs ) is still a matter of debate. It has been suggested that this type of black holes witlrin die mass range of =10“ - 10^ may reside in Ultralummous X-ray sources (ULXs) which are very bright off nuclear X-ray sources. Recently, a new method to constrain the mass of BH systems, based solely on X-ray data, was successfully used for sMBHs and SMBHs. Since the X-ray emission is thought to be produced by the same process (Comptonization) in all accretion objects, in principle, this method can be applied to estimate the mass of black holes in ULXs. We have carried out a systematic analysis of a sample of 43 ULXs with multiple X-ray observations and applied this novel method. Our preliminary results suggest that -70% of die sample harbor IMBHs and indicate a good agreement between the values of BH mass obtained with this technique and those derived with different methods present in the literature. STATUS OF NSU’S RAPID REPONSE ROBOTIC TELESCOPE AT FAN MOUNTAIN,VA. Carlos W. Salgado, Dept, of Physics, Norfolk State Univ., Norfolk, VA 23504. The Norfolk State University (NSU), 60 cm, Ritchey-Chretien, Rapid Response Robotic Telescope (RRRT) is located at Fan Mountain Observatory, Covesvillle, VA, about 15 miles south of Charlottesville, VA. It is afully automatic and remotely controllable telescope, initially equipped for UBVRl photometric studies. The RRRT is used for observational study of compact stars (and their progenitors), and in particular, the early photometry and polarimetry of Gamma-ray Optical Afterglows (GRB-OA), This telescope is part of the Swift follow-up team. The RRRT is a low inertia telescope (fast slew), dedicated to the study of fast transient phenomena, with rapid imaging polarimetry^ capabilities. The RRRT is also a central part of our educational and public outreach projects. For example, the Back Bay Amateur Astronomers use the telescope, and helped to build it. Furdiermore, the RRRT and its data are available to NSU students and other students from the Tidewater area of Virginia. Such users include those at UVa, GWU, ODU, CNU, and JMU. WHAT WE CAN LEARN ABOUT QUANTUM CHROMODYNAMICS (QCD) STUDYING THE MESON SPECTRUM. Carlos W. Salgado, Dept, of Physics, Norfolk State Univ., Norfolk, VA 23504. The study of the hadron spectrum led more than foity years ago to the development of the quark model, where baryons and mesons are described as bound (by a strong interaction) systems of three quarks and of a quark- antiquark pair, respectively. As a component of the current “Standard Model” of particle physics. Quantum Cliromodynamics (QCD) is the accepted theoiy' of the strong interactions. Wlrile much progress has been made in understanding QCD at high energies, strong interactions at the energy regime where hadrons are bounded (confinement) have remained obscure. A clear understanding of this regime is essential, since it is where the strong interactions are dominant (quark are confine into hadrons). While the original quark model still holds and has been proven to reproduce many features of the hadron spectrum, now we know that there are many more aspects (as hadron masses and spins) that cannot be explained only in terms of quarks. The dynamics of strong interaction fields (the QCD’s gluons) plays a crucial role. Mesons, being made by the minimum possible aggregate of quarks (a quark - anti-quark pair), PROCEEDINGS 90**^ ANNUAL MEETING 19 are the simplest quark bounded system and therefore an ideal bench to study the interactions between quarks, to understand the role of gluons, and to investigate the mechanism of confinement. In this talk, we will outline how the modern study of the light-mass meson spectrum can provide information on diose topics. New meson spectroscopy experiments plamied for the future upgrade of Jefferson Lab will be also described. AN ASSESSMENT OF DELIVERY METHODS IN TEACHING UNDERGRADUATE STATISTICS BY DISTANCE LEARNING. T.C. Mosca III, Dept, of Mathematics, Rappahannock Community College. Distance learning is sometimes criticized as being less effective than traditional methods because the teacher is not physically present in the room with the students. In the fall semester of 2011 I taught three sections of MTH 240 Statistics that were nearly identical, The classes differed only in the amount of face-to-face time. One class section was online; there was no face-to-face tmie. The others were two sections of a hybrid class. The hybrid class met once per week by two-way interactive audio and video connection. One section met face to face tlrree times per month, and the other class section met face to face one time per month. Class meetings and additional lessons were recorded. Students in the online class were provided both sets of recordings. All students received exactly the same instruction, with the only difference being the amount of face-to-face time for each section. The proportions of students who were successful vs. the proportions who failed or received a grade of “D” in each section were compared using a Chi-squared multiple comparison routine. Numerical grades were compared using ANOVA, The hypothesis that face-to-face time is a determining factor in student success was not supported. MEASUREMENTS OF STELLAR POLARIZATION USING THE VMI OPTICAL POLARIMETER. GregoiY A. Topasna & DanielaM. Topasna, Department of Physics and Astronomy, Virginia Military Institute, Lexington, VA 24450. We have designed and built an optical polarimeter for use with the Virginia Military Institute’s 0.5 meter telescope. The polarimeter uses an achromatic half-wave plate and Wollaston prism to image the ordinary and extraordinary rays onto a CCD camera after the light passes through a B, V, R, or I filter. Aperture photometry is perfomied to determine the flux for the ordinary and extraordinary stellar images and the normalized Stokes parameters with their associated uncertainties. Obseiwations of unpolarized stars are used to determine instrumental polarization and highly polarized stars are used to determme the instmmental zero-point reference. We present an analysis of the polarhueter and its performance characteristics. COMPARATIVE STUDY OF SELF-ASSEMBLED POLYMER THIN FILMS. D M. Topasna , A. R. Firehammer, & G. A. Topasna, Department of Physics and Astronomy, Virginia Military Institute, Lexington, VA 24450. We fabricated multiple layer polymer thin films using a layer-by-layer self-assembly method by automated and manual fabrication. The films were characterized by UV-VIS-NIR and SEM measurements for a range of thickness values. The characterization results demonstrate that both methods yield films with similar optical and physical properties. 20 VIRGINIA JOURNAL OF SCIENCE ERROR LIMITS, FADE APPROXIMANTS, AND POLE EXTRACTION FOR POWER SERIES. Joseph D. Rudmin, Dept, of Integrated Sci. and Tech., James Madison Univ., VA 22807. George Edgar Parker and James Sochacki have shown how to find, to any order, the Taylor Series approximation to a system of differential equations, if it exists. They and Paul and Debra Warne and David Carothers derived concise closed-form absolute error Imiits for tliis method. For most practical applications, a Fade approximant derived from the Taylor Series provides better fitthan the Taylor Series. However, both Taylor Series and Fade Approximants have difficulty modeling poles in the solution. Often one can best model a pole by a change of variable, where the variable explicitly contains the pole. The change of variable can be found from the differential equations by eliminating the highest order feedback loop in the Parker Sochacki approximation, thus simplifying those equations. TESTING A NEW METHOD FOR ESTIMATING BLACK HOLE MASS IN LOW LUMINOSITY ACTIVE GALACTIC NUCLEI. Christina L, Hughes & Mario Gliozzi, Dept, of Physics & Astronomy, George Mason Univ., VA 22030444. Black holes have recently become a primary topic in astrophysics as it is now known that each galaxy harbors one supermassive black hole at its center. Finding the mass of these black holes is critical to understanding the physical conditions around black holes and to shed light on the cosmological evolution of galaxies. Among techniques devised to determine black hole mass, dynamical methods are considered the most reliable. Unfortunately, such methods have severe limitations (they can be applied only on nearby galaxies) and have led astronomers to seek more far-reaching, universal methods One recently proposed method relies on the ubiquity of the X-ray radiation in black hole systems produced by the Comptonization process and on the analogy between stellar and supermassive black holes. Recently, this method has been successfully applied to black hole systems accreting at a high rate, but has yet to be tested on low-accreting systems. This project explores the limitations of this X-ray based method by applying it to sizeable sample of low accreting black holes whose mass is known via dynamical methods and which possess high-quality X-ray data. In addition to preliminary research in astrophysics literature, this project encompasses data reduction of archival Chandra satellite observations as well as the analysis of spatial and spectral properties of each object. Both analytical and statistical tecliniques, applied in conjunction with an understanding of the physical processes at work, were used to ascertain calculated masses. The results of this project will provide a general understanding of the applicability and/or limitations of this method. Biology with Microbiology and Molecular Biology CONTRIBUTIONS OF CELL DIVISION AND CELL DEATH TO GROWTH AND METAMORPHOSIS OF PHARYNGEAL ARCH CARTILAGES IN THE FROG XENPUS LAEVIS. W. T. Koch, V. K. Horne, & C. S. Rose, Department of Biology, James Madison University, Harrisonburg VA 22801. The pharyngeal arch cartilages of Xenopus laevis, including the lower jaw or Meckel’s cartilage (MC) and the ceratohyal (CH), grow isometrically at tadpole stages and undergo radical shape PROCEEDINGS 90“^ ANNUAL MEETING 21 changes during metamorphosis. The cell behaviors that underlie the growth and shape changes of these tissues are largely unknown. We addressed this issue by mapping the patterns of cell death and cell division in frontal sections through the center of Meckel’s cartilage and the ceratohyal in specimens ranging from early tadpole stages through the end of climax metamorphosis. Dying cells were identified under UV light by DAPI staining that indicated the blebbmg or fragmentation of nuclei. Dividing cells were identified under phase contrast microscopy on the same sections based on the proximity and shape of nuclei, and the thickness and shape of the surrounding extracellular matrix. From these “maps”, the distributions and frequencies of dying and dividing cells within cartilages were determined. Dividing and dying cells were found in both cartilages at all stages greater than NF 53. Cell division occurred at much higher frequency than cell death at all stages, and increased from NF 48 to 65 in both cartilages, as did cell death frequency in CH. There was no obvious change in the frequencies of either cell behavior at the transition from tadpole growth to metamoiphic shape change for either cartilage. MC had generally higher cell division frequencies than CH (25-50% versus 10-35%), and CH had generally higher cell deatli frequencies than MC (0-20% versus 0-1%). QUANTIFYING CELL CYCLE LENGTH DURING THE GROWTH AND METAMORPHOSIS OF PHARYNGEAL ARCH CARTILAGES IN THE FROG XENOPUS LAEVIS. V. K, Home . W. T. Koch & C. S. Rose, Department of Biology, James Madison University, Harrisonburg VA 22807-2012. The pharyngeal arch cartilages of Xenopus kievis, including the Meckel’s cartilage (MC) and ceratohyal (CH), grow isometrically at tadpole stages and undergo radical shape changes during metamorphosis. Questions of how frequently cells divide to contribute to the growth and shape changes of these tissues and dieir progression through the cell cycle were addressed by pulse labeling tadpoles at Nieukoop-Faber (NF) stages 55-56 and 58-59 with BrdU and following the labeled cells through to the end of mitosis. Tadpoles were sampled at 1-5 and 18 days after the injections and frontal sections through the center of each cartilage were made and photographed. Five categories of BrdU labeled cells throughout mitosis were recognized and counted. Interestingly, at least 60% of cells labeled in the S phase in MC and 45% of these cells in CH did not appear to advance to the start of mitosis. Of the cells that advanced tlirough mitosis, those which completed cell division were seen at one day in MC and after two days in CH. The first to complete a second mitosis were seen three days after the pulse in MC; none were observed in CH. These and previous data support a model of cartilage growth wherein a percentage (5-30%) of cells in both cartilages enter the S phase at every tadpole and metamorphic stage, but only a small percentage of these advance to complete mitosis and second mitoses, and another small percentage stall at stages between the S phase and end of mitosis. BrdU appears to not be a good indicator of cell division in frog MC and CH. CONFOCAL MICROSCOPY STUDY OF THE EMBRYONIC DEVELOPMENT OF THE VIVIPAROUS HOPLONEMERTEAN PROSORHOCHMUS AMERICANUS. Steven T Spindle & James M Turbeville, Dept, of Biol, Va, Commonwealth Univ., Richmond VA 23284. Recent studies of hoplonenemertean planuliform larvae have greatly clarified their development and provided insight into larval evolution within the 22 VIRGINIA JOURNAL OF SCIENCE phylum. However, an assessment of viviparous development using modern techniques is lacking. To help facilitate a comprehensive comparative evaluation of developmental diversity within hoplonemerteans, we have initiated a confocal laser scanning microscopy investigation of the development in Prosorhochmus americanus, one of the few nemertean species that is both hermaphroditic and viviparous. Phalloidin staining reveals that the foregut, midgut, proboscis, and body wall musculature form early in development. These results are consistent with those for planktonic hoplonemertean larvae. The cerebral organs form from paired invaginations near the anterior end of the embryo as described for some hoplonemertean planuliform larvae. Acetylated tubulin antibody labeling shows that late stage embryos are uniformly ciliated, and in some specimens, a caudal ciliary cirrus is present, which is characteristic of species with planktonic larvae. The caudal cirrus may be interpreted as a vestigial structure in the non-swimming P, americanus embryos, Our preliminary observations provide no evidence for a transitory larval epidermis during the development of this species, but analysis of additional stages will be necessary to verify its absence. Analysis of the development of the nervous system in this species is ongoing, and both phalloidin staining and acetylated tubulin antibody labeling indicate that the cerebral ganglia and lateral nerve chords are present in early-stage embryos. COURTSHIP SONG STRUCTURE AND MECHANISM OF A PARASITIC WASP. Justin P. Bredlau , Yasha J. Mohajer, Micheal L. Fine & Karen M. Kester, Dept, of Biology, Virginia Commonwealth University, Richmond VA 23284. Insects display a wide range of acoustic signals used in species recognition and courtship. Highly diverse parasitic wasps utilize wing movement or fanning to produce male courtship songs. Although courtship songs have been characterized for several parasitic wasp species, the mechanism of sound production has not been examined. We describe the male courtship song of Cotesia congregata (Hymenoptera: Braconidae) and examine the mechanism behind the production of its high amplitude component with high-speed videography (2,000 fps) and synchronized audio recording. The song consists of wing fanning followed by a series of pulsatile-sounding high amplitude “boings.” Boings are not produced by inter-wing contact or contact with the substrate or abdomen, and maximal sound amplitude does not occur during maximal velocity of wing motion, thereby ruling out atypical mechanical mechanism of sound generation. Instead, boings are generated at the termination of the wing down stroke when displacement is maximal but wing velocity is zero. Calculations iiile out a whip-like action caused by rapid acceleration of the wing tip to supersonic speeds. Therefore, the sound is likely created by aerodynamic vortices produced by the sudden change m wing direction at the bottom of the stroke. Funding was provided by the Thomas F. Jeffress & Kate Miller Jeffress Memorial Trust. GENOMIC COMPARISONS OF BACILLUS BACTERIOPHAGES: THE SEARCH FOR A BACILLUS PHAGE ANTI-RECEPTOR. Zein Al-Atrache & Lynn O. Lewis, Dept, of Biol., Univ. of Mary Washington, Fredericksburg VA 22401. Members of the Bacillus cereiis group including Bacillus cereus {B.c .), Bacillus thuringiensis (B.t.), and Bacillus anthracis (B.a.) are gram positive bacteria with roles ranging from biotechnology to biowarfare. Much research regarding the taxonomy of these species has determined a less than 1% difference in their 16S rDNA sequences, suggesting PROCEEDINGS 90**^ ANNUAL MEETING 23 similar genomic sequences, Little is known about bacteriophages capable of infecting these bacterial hosts. Three novel Bj, subsp. Kurstaki bacteriophages were purified from soil samples throughout Virginia and characterized using restriction enzyme analyses. An observed characteristic of these bacteriophages is their ability to cross- infect hosts, including 5.r. subsp. A1 Hakam and B.ci. subsp. Delta Sterne. The genomes of the three phages were sequenced and annotated to earn a more comprehensive understanding of the similarities and differences among their genomic sequences. Genomic comparisons revealed 96% coverage between the sequences of Phage Hakuna and Phage Megatron and only 5% coverage bet\\'een the sequences of Phage JPB9 and Phages Hakuna and Megatron. Potential bacteriophage anti-receptors that confer host- phage specificity were also annotated in each of the phages’ genomes. In the future, this knowledge gained will hopefully serve to elucidate the processes involved in bacteriophage infection of Bacillus hosts. ANTIMICROBIAL PROPERTIES OF HONEY FROM ENVIRONMENTAL STUDIES ON THE PIEDMONT. Abdulla Hafid, Biology, Dr. Barney Bishop, Biochemistry & Dr. Thomas C. Wood, New Century College. George Mason University. Fairfax, VA. At Dr. Bishop’s laboratory, honey collected from Environmental Studies on the Piedmont, was examined for the bactericidal impact on E.coli (Escherichia) k9. Honey showed to be effective in inhibiting bacterial growth and had greater rates of inhibition with higher honey concentrations. Analysis of the honey indicates the agent is water- soluble and size structure usually associated with that of a small carbohydrate or peptide. From this information, methods to introduce honey products in places of critical need can significantly increase the quality of life. However additional research must be done to precisely indicate the specific agent to be used effectively. NOVEL ARCHITECTURE OF COSTAL CARTILAGE, IMPLICATIONS IN CHEST WALL DEFORMITIES. A Asmar . Stacey M' ^ Fecteau A^ Werner A^ Kelly R Jr^ Trank Reidy Research Center for Bioelectrics, Old Dominion University, Norfolk, VA, USA. ^Department of Pediatrics, Eastern Virginia Medical School, Norfolk, VA, USA. ^Division of General Surgery, Hospital for Sick Children, Toronto, Canada "Dept of Pathology, Eastern Virginia Medical School and Med Director of Laboratories, Children's Hospital of The King’s Daughters, Norfolk VA, USA. ^Depaitment of Surgery, Eastern Virginia Medical School and Pediatric Surgery Division, Children’s Hospital of the King’s Daughters, Norfolk VA, USA. Costal cartilage is a type of hyaline cartilage that is relatively uncharacterized in comparison to load-bearing cartilage. Abnormal formation of costal cartilage is associated with the congenital chest wall deformities pectus excavatum and carinatum. Our present study is part of a larger ongoing project in characterizing the ultrastructural biology of costal cartilage. Using immunohistochemistry, we analyzed the distribution of two important proteoglycans, Biglycan and Decorin. These proteoglycans, also kno^vn as small leucine-rich proteoglycans (SLRPs), play important roles in collagen fibril fonnation and organization. Our results showed that localization of pro-Biglycan, mature Biglycan, and mature Decorin were mainly in the territorial matrix, whereas pro-Decorin localized in the chondrocytes. The difference in functional properties of pro- and 24 VIRGINIA JOURNAL OF SCIENCE mature forms are not well understood, and further investigation is needed to determine the functional impact of these results. EXPLORING THE ROLE OF A NOVEL ZINC-BED DOMAIN CONTAINING TRANSCRIPTION FACTOR, CG3995, IN MEDIATING CYTOSKELETAL ARCHITECTURE DURING DENDRITE MORPHOGENESIS. V. Thota, S. Prakash, L. Sullivan, Y. Lau, M. Garland, S. C. Iyer, E. P. R. Iyer & D. N. Cox, Department of Molecular and Microbiology, George Mason University, Fairfax, VA 22030. Neurons are highly complex, polarized cells that come in an astonishing number of shapes and sizes, attributable largely to their elaborate dendritic branching patterns. As dendrites are primarily specialized to receive/process neuronal inputs, the specific morphology of the dendrite can govern neuronal function, signal integration, and circuit assembly. Drosophila dendritic arborization (da) sensory neurons have emerged as an exceptional model for dissecting the molecular mechanisms regulating class-specific dendrite development. Investigations using da neurons as a model system have revealed important roles for a broad range of biological processes including transcriptional regulation, cytoskeletal regulation, cell signaling and cell-eell interactions in mediating class specific dendritic architecture. Intriguingly, transcriptional regulation has been demonstrated to mediate da neuron dendritic morphology via modulation of the actin and microtubule cytoskeletons. We have recently identified and characterized a novel zinc-BED domain containing transcription factor, CG3995, which was found to be critical for the development of higher-order dendritic branches. To explore the potential functional mechanism via which CG3995 exerts control over dendritogenesis, we examined how changes in the levels of CG3995 expression may impact cytoskeletal architecture. To facilitate these studies, we have developed a unique transgenic Drosophila strain that enables simultaneous confocal imaging of F-actin and (3-tubulin in live Drosophila da neurons in vivo. This approach has provided new molecular insight into the action of the CG3995 transcription factor in mediating cytoskeletal changes that ultimately result in class-specific dendritic patterning. INVESTIGATING ABIOTIC AND BIOTIC INFLUENCES ON SPACE USE OF TWO SMALL MAMMALS IN SOUTHEASTERN VIRGINIA. Sarah A. Crawford & Robert K. Rose, Department of Biological Sciences, Old Dominion LJniversity, Norfolk VA 23529. Relatively little is known about the relationship between syntopic Sigmoclon hispicius (hispid cotton rat) and Reithroclontomys sp. (harvest mouse), Literature on the associations between these two species suggests that competition may exist, particularly in southern populations; however both seem to be greatly affected by environmental and seasonal changes, making it difficult to draw any definite conclusions. Analysis of data from 34 consecutive months of live trapping on a fonner agricultural field in secondary succession in Southeastern Virginia revealed space use by both species to be more influenced by microhabitat preference than interspecific density. Hispid cotton rats were most influenced by ground elevation (r^ = 0.45, p=0.0002, N=64) and eastern harvest mice were most influenced by tree size and abundance (r3=0.52, p=0.00001, N=64). As favorable habitat diminished through succession, hispid cotton rats stayed closer to food sources at the cost of moving to wetter, less appealing habitat, whereas eastern harvest mice were less affected, their distribution similar until the study site was abandoned. Hispid cotton rat and eastern PROCEEDINGS 90**^ ANNUAL MEETING 25 harvest mouse captures were not found to be significantly correlated. A finer examination over an extended study period may yield stronger associations but overall these two species appear to coexist, not compete, in Southeastern Virginia. THE EPIGENETIC EFFECTS OF ENVIRONMENTAL POLLUTION ON AQUATIC SPECIES. Shawn Mitchell & Lisa Horth Dept, of Biol. Old Dominion Univ. Norfolk VA 23529. This is an ongoing study gathering data on epigenetics in Micropterus salmoides, Callinectes sapidus, Fundulus heterocUtus, and Littorina littorea. Methylation patterns may be globally reversed if many tumor suppressor genes are switched on which leads to observing the genomes of these species to see if their methylation rates may be reversed when extracted from a dirty enviromnent and placed in a clean environment. Various tanks were set up in a controlled environment in our lab to simulate different measurable conditions of pollution. These species then had their genomes extracted and quantified. These genomes are currently be used to determine their rates of methylation. Once the rates of methylation have been determined, we will analyze our data to find a correlation between epigenetics and environmental pollution among species of the Chesapeake Bay watershed. Posters THE IMPACT OF LEAD TOXICITY ON CAENORHABDITIS ELEGANS POPULATION. Hunfa Asghar. Gita Sudama, Danial Khan, Anima Adhikari & Dr. Willet, School of Systems Biology^ George Mason University, Manassas, VA 20110.The nematode, Caenorhcdniitis elegans (C elegans) is an excellent model system in which to study fundamental biological processes of eukaryotic multicellular organisms. They provide ideal models for determining mechanisms of neurotoxins, such as the environmental contaminant, lead (Pb). The impact of lead toxicity (0,250, 500 and 1000 parts per million [ppm] ) on C. elegans populations was monitored. It was carried out by direct observations of the treated nematodes populations under the light microscope, over a period of nine (9) days. Life stages counts and live/dead ratios were recorded for each population. Population profile changes were observed with lead dose treatment. Increases in dauer C. elegans were observed with lead treatment. Decreases in population size and distribution were seen with lead treated C. elegans populations. The number of dead nematodes increased with lead concentration, over time. A SYSTEMS GENOMICS APPROACH FINDS CANDIDATE GENES FOR NON¬ INSULIN DEPENDENT DIABETES MELLITUS. J. James, L. Jones, B.L. Sayre and G.C. Harris, Department of Biology, Virgmia State University. Non-insulin dependent diabetes mellitus (NIDDM ) is one of the most significant chronic human diseases, affecting over 20 million people in the United States (7% of the population). NIDDM is associated with obesity and characterized primarily by insulin resistance and impaired insulin production. In this study a multiple SNP (single nucleotide polymorphism) analysis was conducted to identify potential candidates for the disease. Mouse SNP data was mined from databases that included strains for accepted NIDDM models Tallyho (NIDDM model) and SWR/J (wild type). Expressed genes were captured in the form of mRNA, converted to cDNA, and analyzed for differential expression in 4 different tissues (fat, skeletal muscle, liver and pancreas). The results 26 VIRGINIA JOURNAL OF SCIENCE show several of the gene candidates tested were found to be differentially expressed (DE) in various tissue samples; Alpkl, Hfe2, Manba, Slc22al5, Slc30a7 and Tchhll. Future efforts can now focus attention and resources on these likely candidates for NIDDM with obesity phenotypes. These efforts confum the significant impact a systems genomics approach can have on identifying potential candidates for multigenic inherited human diseases such as NIDDM. THE EFFECTS OF POSITIVE AND NEGATIVE STRESSORS ON THE RATIO OF URIC ACID TO XANTHINE IN CAENORHABDITIS ELEGANS. Anima Adhikari , Gita Sudama, Danial Khan, Hunfa Asghar, Neeraja Podugu, Jenifer Isbister & James D. Willett, Department of Systems Biology, George Mason University, Manassas VA 20110. Caenorhabditis elegans (C elegans) seiwe as an excellent model system in which to study fundamental biological processes of eukaiyotic multicel lular organisms. They are ideal models for determining mechanisms of action of neurotoxins, reactive oxidative stress and aging. In this study C. elegans populations were separated into three different cohorts, cohort 1 (young < 20 pm), cohort 2(middle aged 20 - 35 pm) and cohort 3(adult > 35 pm) to examine how each cohort react to positive (vitamins C and E) and negative (lead acetate and aging) stressors. Uric acid (uric) and xanthine (metabol ites of the purine degradati ve pathways) concentrations were measured by the application of high perfonnance liquid chromatography coupled to electrochemical detection (Coularray/HPLC). The ratio of uric/xanthine was calculated to demonstrate change in flux of the fonnation of uric acid, from xanthine, on exposure to the stressors. In one experiment, the C. elegans populations were age separated (into cohorts 1, 2, and 3) and then treated with lead acetate (0,250,500, 1000 ppm) for 2,5 hours. The Uric/Xanthine ratio increased with dose treatment for each cohort. In a second experiment, the C. elegans populations were grown with vitamm C [C] (0,0.1,0.5, 1.0 mg/ml), vitamin E [E] (0, 0.1, 0.5, 1 mg/ml) and vitamin C & E ([0.1 C + 0.1 E], [0.5 C + 0.1 E], [0.5 C + 0.5 E], [0.1 C + 0.5 E]) and age separated. The Urie/Xantliine ratio fluctuated with dose treatment for each cohort, due to the antioxidant properties of the vitamins. INDUCTION OF APOPTOSIS BY NONSTRUCTURAL PROTEINS OF THE SINDBIS VIRUS IN XENOPUS LAEVIS EMBRYOS. Kaitlyn Childs, Jacob Graham, Kevin M. Myles, Ph.D. & Carla V. Finkielstein, Ph.D., Virginia Polytechnic Institute of Virginia, Blacksburg VA 24060. Viral infections are of interest as is related to virotherapy and host-virus interaction studies for mechanism construction that may result in knockout therapies to reduce or diminish virulence. Sindhis virus, an Alphavirus of the Togavnidae family, is transmitted by mosquitos; the endogenous strain is opportunistic, infecting immunocompromised mdividuals, elders and young children. The viral genome is divided into nonstructural (ns) and stmctural open reading frames. The nonstmctural region encodes a polyprotein consisting of nsPl, nsP2, nsP3, and nsP4. In this study, we have found that the nonstmctural protein nsp3 has the ability to induce apoptosis in an heterologous system and that this property is restricted to its N-terminus domain. Interestingly, whereas the nonstructural polyprotein is able to trigger apoptosis inXenopus embryos when a polycistronic mRNA is injected in one-cell stage, neither nspl, 2 nor 4 was able to accomplish this form of cell death on their own. Apoptosis was confirmed by measuring caspase-3 activity, visualization PROCEEDINGS 90“^ ANNUAL MEETING 27 of membrane blebbing, and cleavage of cyclin A2, a known caspase substrate in Xenopus early embryogenesis. Next, we investigated whether nsp3 pro-apoptotic activity was inhibited by interacting with anti-apoptotic members of the Bcl-2 family. Thus, Xenopus laevis embryos were injected witli various nsp3 constructs in one-cell, collected at different times before MBT and will be analyzed for binding by immunoprecitadon. We hope to elucidate the mechanism behind apoptosis induction of the Sindbis virus in Xenopus laevis embryos in this way. POINT MUTATIONS THAT DRIVE PIGMENTATION DIFFERENCES IN MOSQUITOFISH. Hampus A. Engstroem & Lisa Horth, Dept, of Biol., Old Dominion University, Norfolk, VA 23529. Melanie pigmentation is widespread in nature, and plays a crucial role in species fitness, The eastern mosquitofish {Gambusia holbrooki) melanic male morph is found in natural populations at frequencies typical ly maintained below 0.05 of the male population. A single albino western mosquitofish {Gambusia affinis) was found in nature and bred in captivity. To elucidate the genetic mechanisms that contribute to these two veiy^ rare phenotypes the genes encoding the melanocortin- 1 receptor (MCIR) and enzyme tyrosinase (TYR) were analyzed for nucleotide sequence variation and gene expression differences. Sequence analyses of both genes revealed non-synonymous mutations in melanics and albinos as compared to the wild- types. Expression of both genes was higher in melanics compared to wild-types, and lower in albinos for both genes. These results demonstrate for the first time a correlation between gene expression differences and unique genotypes in the melanin biosynthesis pathway. (Supported by National Science Foundation, and Jeffress Memorial Trust.). EFFECTS OF VITAMIN A METABOLITES ON APOPTOSIS. Anne M. Campbell and Rosemary Barra, Dept, of Biol. Sci., Univ. of Mary Washington, Fredericksburg, VA. 22401. Retinol is a metabolite of vitamin A found in all mammalian cells. Retinol must be converted to retinoic acid in order to be used by cells and the cis and trans isomers are common metabolites. Studies suggest that retinoic acid affects cellular growth and differentiation in a dose dependent manner. The objective of this experiment was to detennine the effects of retinoic acid on CRT 1790 colon epithelial cells. The cells were incubated with 1 mM, 10 mM and 100 mM of 13-cis retinoic acid andall-trans retinoic acid (ATRA). Cell viability was determined usingtheMTT assay and the concentration of CD95 was determined following an ELISA procedure. The lOOmM concentration of both 13-cis retmoic acid and ATRA decreased cell viability to 60.37% and 69.16% of control, respectively. The 1 mM and 10 mM concentrations did not significantly affect cell viability. The results of the ELISA showed tliat cells treated with lOOpM 13-cis retinoic acid and lOpMall-trans retinoic acid had increased concentrations of human CD95 suggesting that they increase apoptosis in CRL1790 epithelial cells. Further experimentation should be done to confimr tliese results. THE EFFECT OF CLIMATE CHANGE AND OIL SPILL ON BLACK-SPOTTED MOSQUITOFISH GENOTYPE lordankaN. Panayotova, Department of Mathematics and Statistics, Ann Creasy & Lisa Horth, Department of Biological Sciences, Old Dominion University, Norfolk, VA 23529. In this work, we use a numerical model, and employ a suite of empirically derived relative fitness values, to simulate the change in 28 VIRGINIA JOURNAL OF SCIENCE frequency of two color-pattern morphs over time in a large population of conspecific fish (Gamhusia holhrooki). Numerical simulations are employed to model dynamics of the black-spotted mosquitofish genotype. It is shown that the climate change may have a devastating effect on the mosquitofish resulting in extinction of die motted-black eastern mosquitofish genotype. In contrast, if an oil spill happens and kills 80% of the population of mosquitofish, the remaining 20% are enough for the population to return to the equilibrium observed in nature however it may take over 100 year for the stabilization to occur. ATTACHMENT AND BIOFILM FORMATION OF CITROBACTER RODENTIUM IN THE MOUSE INTESTINE. Michael W. Canfarotta & Andrew J. Fabich, Department of Biology and Chemistry, Liberty University, Lynchburg VA 24502. Citrohacter rodentium DBS 100 is an enteric murine pathogen similar to enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic Escherichia coli (EPEC) as it forms an attaching and effacing (A/E) lesion during gastrointestinal infection. Attachment has been previously shown to be an important initial step m both colonization and biofilm formation. However, the mechanism of colonization of C. rodentium in the mouse intestine is poorly understood. In vitro biofilm formation assays were perfonned comparing the ability of pathogenic DBS 100 and commensal E. coli strain MG1655 to form a biofilm on a polystyTene surface while grown in media containing specific carbon sources commonly found in intestinal mucosa. In vitro, pathogenic DBS 100 demonstrates increased biofilm formation when grown on fucose and mannose whereas commensal MG 1655 forms greater biofilms when grown on ribose. The data suggests that pathogens may form a biofilm during gastrointestinal infection by utilizing sugars that are not important in the biofilm formation of commensal intestinal microbiota. Microbiology and Molecular Biology NF-kB DEPENDENT FAS SIGNALING IN HEPATOCYTES. Ouoc Tran ^ l Rohini Mehta“, Aybike Birerdinc",& Ancha Baranova’ ", ’Biology Department, George Mason University, "Betty and Guy Beatty Center for Integrated Research, Inova Health System. The high prevalence and substantial morbidity and mortality accompanying Non alcoholic fatty liver disease (NAFLD) makes it imminent to understand the mechanistic basis of this disorder. Hepatocyte apoptosis, is an important mechanism in the pathogenesis and progression of NAFLD with Fas signaling being an important player. The focus of the current study was to determine whether chemokines CCL21 and CCL4 induce Fas ligation and, if so, whether the Fas signaling activates downstream NF-kB mediated inflammatory pathway, or caspase-3 dependent apoptosis. HepG2 cell line was used as in vitro model for the current study. For qPCR, cells were subjected to var>ang concentration of individual chemokines in a time course experiment of 2, 4, 6 and 8 hours. mRNA was extracted from the cells using Qiagen RNeasy kit (Qiagen, USA) according to manufacturer’s protocol cDNA synthesis was carried out using First strand synthesis kit (Qiagen). qPCR was performed on 18 genes specifie to Fas signaling and NF-kB inflammatory pathway. For ELISA, cells were subjected to varying concentration of individual chemokines in a time course experiment of 6,8,12 and 24 hours. After stimulation, supernatants were collected and PROCEEDINGS 90“^ ANNUAL MEETING 29 subjected to ELISA using custom Multi-analyte ELISArray kits from Qiagen (Fredericks, MD) according to the manufacturer's suggestions. Apoptosis was evaluated by detection of caspase-3/7 activity using Caspase-Glo 3/7 Assay (Promega). Apoptosis results were in agreement with the apoptotic and anti-apoptotic gene expression pattern. IDENTIFYING TARGET GENES IN THE ERR GAMMA PATHWAY RESULTING FROM BPA EXPOSURE IN BREAST CANCER. K.L. Voss & DA O’Dell, Dept Biological Sciences, Univ Mary Wash., Fredericksburg, VA, 22401. Bisphenol A(BPA binding) to the Estrogen Related Receptor Gamma (ERR-y) was studied to detennine whether it can lead to alterations in the cell cycle by affecting the activity of oncogenes and tumor suppressor genes. Normal breast epithelial cells were divided into 3 groups; control and 2 experimental groups. Estrogen and Androgen receptors were blocked in experimental groups using fulvestrant and p-p’-DDE. ERR-y activity was blocked with 5 uM 5-Hydroxytamoxifen. Vz of each group was exposed to 5 pM of BPA in normal culture medium for 72 hours. Total RNA was extracted and assayed using RT-PCR and a commercially available microarray (SABioSciences).Twenty-one genes were found to be upregulated and 7 were down regulated in response to BPA exposure in cells with no receptors blocked. When the ERR-y receptor was active, only 4genes were upregulated and 7 were down regulated. When the ERR-y receptor was blocked, 3genes were up regulated and 4 showed downregulation. The results show that BPA does alter gene activity which could lead to changes in the cell cycle leading to a cancerous state. The results also indicate that there is yet another receptor through which BPA can exert its effects. This work was supported by an Undergraduate Research Grant (UMW) to KV and a Mary Louise Trust Award (VAS) to DAO. GENE EXPRESSION IN HUMAN GLIOBLASTOMA CELLS POST CELL PHONE RADIATION EXPOSURE. K.M Meyer & DA O’Dell, Dept Biol. Sci., Univ. Mary Wash. Fredericksburg, VA 22401. The effects of cell phone radiation on gene expression in human glioblastoma cells was studied to determine whether EMF exposure could lead to changes in genes which regulate the cell cycle. Human glioblastoma cells were cultured to a G1 arrested state after which they were exposed to 25 min of cell phone radiation (Avg 57.3 mW/m" ), Total RNA was extracted at Omin -20 min-24 hour time intervals after exposure, RT-PCR using a commercially available microarray (SABiosciences) for 84 oncogenes and tumor suppressor genes was used to analyze the changes in gene activity. Cells responded immediately after exposure by upregulating 45 genes, many of them tumor suppressor genes. After 24 hours, tire number of gene upregulated increased to 71, with more tumor progression genes (oncogenes and transcription factors) activated. Two genes promoting cell death (CASP8 and FHIT) showed significant changes after 20 min while after 24 hours, significant changes were seen in 3 genes, one of which was JUND, a transcription factor and oncogene. The results show that cells respond to cell phone radiation exposure by activating genes which promote tumor suppression initially followed by genes which are involved in tumor promotion. More work to establish long term effects of cell phone radiation on gene activity in cells is needed to determine the role of cell phone radiation in promoting cancer. This work was supported by an Undergraduate Research Grant (UMW) to KM. 30 VIRGINIA JOURNAL OF SCIENCE ADAR FACILITATED RNA EDITING IN HUMAN PLASMACYTOID DENDRITIC CELLS (PDC). A. Sharmal, Lamva AlomairL Katherine Doylel, Patrick Gillevet3, Masoumeh SikaroodiS, Aybike Birerdinc 1,2^ & Ancha Baranova 1,2, 1, School of Systems Biology, George Mason University, Fairfax VA 22030, 2Betty and Guy Beatty Center for Integrated Research, Inova Health System, Falls Church, VA 22042,3 Microbiome Analysis Center, George Mason University, Manassas, VA 20100,4National Institute of Health, Bethesda, MD 20892. Adenosine (A) to Inosine (I) RNA editing is facilitated by enzymes known as ADAR (Adenosine Deaminase that Act on RNA). ADARs specifically recognize double stranded RNA structures or RNA duplex structures as their substrates. Inosine is translated as Guanosine, since most enzymes recognize Inosine as Guanosine. Examples of physiological ADAR editing are edits to neuronal Glutamate and Serotonin receptor transcripts. Here we set to find out whether ADAR-editing in human PDCs (Plasmacytoid Dendritic Cell) is limited to TLR7, or whether it covers other known ADAR targets, including other TLR receptors, FLNA, IGFBP7, KCNAl, GABRA3, and CYFIP2. Site specific pruners around previously known edited sites were designed using NCBI primer blast and then tested on cDNA derived from universal RNA and adipose tissue. Purified cDNA from PDC cells was used as templates for PCR amplification, tagged, purified, and subjected to Multitagged (MTPS) pyrosequencing on Roche GS-FLX instrument. The pyrosequencing data was assembled using Lasergene’s Seqman Pro to assemble all the contigs. USE OF CO-EXPRESSION PATTERNS FOR FUNCTIONAL ANALYSIS OF HUMAN GENES (KCNRG & KCTD7) WITH LTNCLEAR CELLULAR ROLES, Sarath Babu Kiishna Murthv’ , Hannali Choi" & Ancha Baranova'-^ 'School of Systems Biology, George Mason University, Manassas, VA,"Biology Department, George Mason University, Fairfax, VA,^Betty and Guy Beatty Center for Integrated Research, Inova Health System, Falls Church VA. KCNRG is a soluble protein with characteristics suggesting it forms hetero-tetramers with voltage-gated K+ channels and inhibits their function. The ONCOMINE database is an online collection of microarrays from various sources, usually cancer-related, and contains many "multi-arrays". The KCTD7 gene is a paralog of the KCNRG gene that also binds to cullin 3. We analyzed 10 different datasets containing 100 different genes each for common overlapping co¬ expressed genes of KCNRG, using multiple cancer studies within the Oncomine database, focusing here predominantly upon brain and cns cancer studies. Meta¬ analysis result, with frequency of 3 or more, for KCNRG yielded 95 hits and was further assessed for ontology and full gene names. This genelist was used as input file for an advanced analysis usmg Metacore^'^, an integrated software suite for pathways and network analysis of OMICs data. GeneGo Pathways Maps show that top scored map (map with the the lowest p value) based on the enrichment distribution sorted by 'Statistically significant Maps' set is Transport RAN reglation pathway. Analysis of co¬ correlations is a powerful tool that allows one to get a glimpse into function of genes with no known function Cancer-related Oncomine database is a suitable input for analysis of co-correlations. PROCEEDINGS 90**^ ANNUAL MEETING 31 MDM2 IS AN UBTQUITIN E3 LIGASE MEDIATING PROTEASOME- DEPENDENT DEGRADATION OF CIRCADIAN RHYTHM PERIOD 2. Jingjing Liu, Dept, of Biol., Virginia Tech., Blacksburg VA. 24061, The circadian rhythm and cell cycle are the two main oscillatory systems in cells. How cells sense time and decide what is the best time for growing, dividing or die? One possibility is that there are crosstalks between these two systems. Based on tire fact that Period 2 (Per2) also plays essential role in DNA damage response {Fu, L, and Lee, C. C. 2002), Per2 is supposed to connect circadian rhythm and cell cycle, which makes Per2 work as a tumor suppressor. We found Per2 regulating p53 pathway but little is known about how Per2 itself is regulated. One interesting finding is that independent of transcriptional regulation, overexpressed Per2 protein also oscillating, this implies posttranslational modifications are essential for sustaining Per2 protein oscillation. Per2 binds to Mdm2, a well-known E3 ubiquitin ligase, both in vitro and in vivo. Mdm2 induces Per2 ubiquitination in vitro, but further experiments are needed to verify Mdm2 is an E3 ligase for Per2 in vivo. GLOBAL CHARACTERIZATION OF DNA METHYLATION PATTERNS IN AN ALZHEIMER’S DISEASE MODEL. Courtney A. McKenzie . Rebecca C. Garrett, NoorM. Taher& Gary D. Isaacs, Dept, of Biology and Chemistry, Libert}' University, Lynchburg VA 24502-2269. Epigenetics play a role in regulating transcription through gene silencing by DNA methylation. Epigenetics have been implicated in multiple diseases. This experiment consisted of a genomic scale analysis of neuronal cells to determine the methylation patterns associated with models for mature neurons, cancer, and Alzheimer’s disease (AD). The restriction endonucleases MspI and Hpall were utilized because they both cleave methylation sensitive regions, but Hpall only cleaves these sequences when they are not methylated. To determine genomic metliylation patterns, DNA from each model was differentially digested with the enzymes and hybridized with fluorescent markers to a microarray. Analysis revealed global differences in methylation levels between cancer, mature neuron, and AD models. Regions have been identified where a gene’s methylation status is different in the AD model than it is in the mature neuron model. These regions represent genes that were either turned on by hypomethylation or turned off by hypermethylation as a result of AD pathogenesis. Gene specific studies to determine the affected cellular processes are currently in progress. EXPRESSION OF THE PROPANOYL-COA METABOLIC PATHWAY FROM T. fusca IN E. coli. Allison Yaguchi & Dr. Stephen Fong, Dept, of Chemical and Life Sciences Engineering, Virginia Commonwealth Universit}'. The objective of this project was to successfully express a metabolic pathway found in Therrnobifida fusca, a thermophilic, cellulolytic actinobacteria, in the model organism, Escherichia coli. A potentially novel method for biologically producing 1-propanol was found in an engineered strain of T. fusca. Direct confirmation of the novel pathway’s activity is difficult in T. fusca, thus expression of the target pathway in E. coli would provide a direct means of testing the novel pathway The T. fusca gene, Tfu_2395, was transformed into E. coli and positive transformants were confirmed with blue/white screening and DNA sequencing. Secretion of 1-propanol by the engineered strain of E. coli would functionally demonstrate the activity of novel metabolic pathway for 32 VIRGINIA JOURNAL OF SCIENCE production of 1-propanol found in T, fusca and secondary confirmation will be achieved using molecular measurements such as real-time PCR of pathway genes. This research was funded by the Virginia Academy of Science and Virginia Commonwealth University. ROLE OF RETINOIC ACID INDUCED-1 (RAll) DOSAGE JN XENOPUS EMBRYOGENESIS AND THE FORMATION OF CRANIAL NEURAL CREST DERIVATIVES. R.Tahir^ A.J.Dickinson-, & S.H.Elsea\ 'Center of the Study of Biological Complexity, ’Dept, of Biology and ^Depts. of Pediatrics and Human & Molecular Genetics, Virginia Commonwealth University. Haploinsufficiency of transcription factor Retinoic acid indiiced-1 (RAIT) is the primary cause of Smith- Magenis Syndrome (SMS), a rare congenital disease marked by mental retardation, craniofacial abnormalities, obesity, and an inverted circadian rhythm, In the present study, we characterize the expression of Rail during embryonic development of Xenopus using whole-mount in situ hybridization. Furthermore, we reduce the dosage of Rail during development using an antisense morpholmo and analyze the resulting abnormalities. Our work demonstrates tha.t Rail is higlily expressed in facial and dorsal regions of the developing embiym, with Rail expression in maxillary and nasal prominences. In addition, expression is localized to a region that appears to be migrating neural crest. A disturbance in Rail dosage during development can lead to significant craniofacial abnomialities, including abnoimal formation of cartilage and cranial nerves, two important cranial neural crest derivatives. This study was funded in part by Howard Hughes Medical Institute and Virginia Academy of Science, SUPPRESSION OF THE MATURATION AND ACTIVATION OF THE DENDRITIC CELL LINE DC2.4 BY MELANOMA-DERIVED FACTORS. Kristian M. Hargadon . Osric A. Forrest, & Pranay R. Reddy, Dept, of Biol., Hampden-Sydney College, Hampden-Sydney VA 23943. Dendritic cells play important roles mboth innate and adaptive immunity, and their numerous functions are tightly linked to then- maturation and activation status. Many tumors have been shown to induce anti-tumor immune dysfunction, but the basis for this dysfunction is often unclear. Here, we characterize the influence of melanoma-derived factors on the maturation and activation of the murine dendritic cell line DC2.4. Exposure of DC2.4 cells to the Toll¬ like receptor ligand lipopoly saccharide induces both maturation and activation of these cells, characterized by upregulation of costimulatory molecule expression and proinflammatory cytokine/chemokine production, This maturation and activation is suppressed by sol uble factors derived from both the highly tumorigenic B16-F1 and the poorly tumorigenic D5.1G4 murine melanoma cell lines, hiterestingly, tire extent of DC2.4 immunosuppression by these melanomas correlates with their tumorigenicity. The impact of diis suppression on the quality of T cell responses elicited by tumor- altered dendritic cells points to a critical role for tumor cell/dendritic cell interactions in regulating the quality of anti-tumor immune responses. (Supported by; Virginia Academy of Science Jeffress Research Grant Virginia Foundation for Independent Colleges Mednick Memorial Fellowhsip, Virginia Foundation for Independent Colleges Undergraduate Science Research Fellowship, Sigma Xi Grant-in-Aid of Research, and Hampden-Sydney College Research Grant from the Arthur Vining Davis endowment). PROCEEDINGS 90**^ ANNUAL MEETING 33 CELL FUSION AND THE GROWTH FACTOR IGF IN MYOCARDIAL REPAIR. Syeda S. Baksh, Dept, of Biol, The University of Mary Washington., Fredericksburg VA, 22401. Traditionally, the myocardium has been considered terminally differentiated tissue due to the incapability of cardiomyocytes to regenerate in adult life. Therefore, tliese cells are not able to compensate for the cell loss as a result of myocardial hifarction. However, m the past couple of years, tliere has been significant evidence that the heart does have regenerative potential. This evidence suggests that in response to growth or injury, the myocardium recruits stem cells/progenitor cells to repair and regenerate. One mechanism possibly used to differentiate the stem cells of the heart into cardiomyocytes is known as cell-cell fusion. In order to enhance fusion, previous studies have employed insulin-like growth factor (IGF), and the results illustrated that the addition of IGF was successful in skeletal muscle cells. Our goal in this study is to show whether or not stem cells fuse with cardiomyocytes, if IGF promotes this fusion, and if fusion stimulates the cardiomyocytes to reenter the cell cycle. Cardiac stem cells and cardiomyocytes were isolated from newborn rat pups and adult rats (respectively) using the Wortliington Biochemical Corp. Neonatal Cardiomyocyte Isolation System. After fluorescently labeling the stem cells with a Qtracker® Cell Labeling Kit, they were co-cultured wnth the cardiomyocytes for four days. IGF was added to half of the cultures. After four days, fusion was assessed and was observed in the culture with IGF, but was not observed in the culture without IGF, indicating that IGF successfully enhanced fusion of cardiac stem cells with cardiomyocytes. Whether fusion stimulates cardiomyocytes to reenter the cell cycle could not be investigated due to a shortage of time. THE EFFECTS OF EXERCISE TRAINING AND ESTROGEN ON THE ATHEROSCLEROTIC PLAQUE SIZE AND COMPOSITON. Leslie N. Valenzuela & Kathryn E. Loesser, Dept, of Biol, University of Mary Washington, Fredericksburg VA 22401. Atherosclerosis and cardiovascular disease are the leading cause of death in the western world. Twelve normal mice and twelve Apolipoprotein E deficient mice were used to investigate the effects of exercise training and estrogen on the atherosclerotic plaque size and composition in atherosclerosis-prone mice. Half of the mice were labeled as sedentary and the other half were under the exercise protocol. In the beginning of the study, the mice were fed a normal chow diet. At six weeks of age, the mice w^ere switched to a high fat diet. At six weeks of age, twelve mice that were under the exercise protocol began their exercise, which was swimming. The mice swam for a total of six weeks. At the start of a new week, 4 minutes were added to the swimming protocol. A program called ImageJ was used to measure the blood vessel wall thickness of the mice. An Estradiol EIA Kit was used to measure the estradiol levels in the mice. A student’s t-test with unequal variance was used to find statistical differences for the estradiol levels between tlie males and females. There was no statistical difference between the levels of estradiol in the males and females of either normal or Apolipoprotein E deficient mice. For the blood vessel wall thickness, all the mice that swam had a smaller blood vessel wall thickness than the mice that were sedentary highlighting that exercise leads to having healthier arteries. It appears that exercise is more important than either gender or predisposition to atherosclerosis in preventing vessel wall thickening. 34 VIRGINIA JOURNAL OF SCIENCE CRMl-INDEPENDENT NUCLEAR EXPORT OF THE THYROID HORMONE RECEPTOR IS MEDIATED BY EXPORTIN 5. K. S. Siibrmanian. H. N. Nelson, & L. A. Allison, Biology Department, College of William and Maty, Williamsburg VA 23185. Thyroid hormone receptors (TRal and TR(31) bind to thyroid honnone to regulate target genes involved in metabolism, growth, and development. Although primarily found in tire nucleus, TRs rapidly shuttle in and out of the nucleus tlrrough the nuclear pore complex. Previously, we showed that TR nuclear export is not completely blocked when the export factor CRMl is inhibited, suggesting that TR can also exit the nucleus by a CRMl-independent pathway. To determine which export factors are involved in the CRMl-independent pathway, RNA interference was used to knockdown gene expression of several different export factors. The effect of knockdown on the shuttling kinetics of GFP-tagged TR (al and j31) was assessed in live HeLa cells using FRAP. Knockdown of exportin 5 altered TRs nuclear export dynamics; recovery was markedly slower in photobleached nuclei, indicating that nuclear export was inhibited. To detennine whether increased nuclear export had an impact on TR-mediated gene expression, we co-expressed TR. exportin 5, and a thyroid hormone response element (TRE)-mediated CAT I'eporter gene. CAT ELISA showed a decrease of TRE-mediated CAT reporter gene expi'ession when increased amounts of exportin 5 wei'e present. Fuither, we showed that when exportin 5 is over-expressed, the distribution of TR shifts to a more cytoplasmic localization. Taken together, our data suggest that TR nuclear export is mediated, in part, by exportin 5, and that disrupting the fine balance between nuclear import and export can lead to changes in TR-mediated gene expression. (Supported by; NIH #2R15DK058028-03 to LAA) EARLY MARKERS OG CYTOGENETIC ANOMALIES IN THE INTERPHASE NUCLEI. Tatiana Glazko. N anobiotechnology Centre of Russian State Agrarian University - MTAA named after K.A.Timiiynzev, Moscow^ Russia Cytogenetic anomalies are common in both premalignant and malignant cells. Formation of the cells with these anomalies is multifactorial process that is disturbed as a result of the disruption or insufficiency in the chromosomal arrangement in interphase nuclei. Our observations indicate tliat, in normally functioning nucleus, the paternal and maternal haploid chromosome sets behave relatively mdependent of each otlier. Here we present the data supporting this hypothesis and derived from the study of the following models: metaphase plates in the peripheral blood lymphocytes of the cattle and polythene chromosomes in the salivary glands of Chironomus thiimmi larvae. Close contacts between haploid chromosome sets enliance the stability of the cell’ genome, while its relative dissociation leads to an increase in the frequency of aneuploidy. CHERNOBYL LESSONS IN GENETICS: AN ADAPTATION OF MAMMALIAN POPULATIONS TO THE EXTREME ECOLOGICAL STRESS Valeiw Glazko . Nanobiotechnology Centre of Russian State Agrarian University-MTAA named after K.A.Timiryazev, Moscow, Russia. In 1986, Chernobyl disaster forever changed our understanding of the place of human kind within the Earth’ environment. Twenty five years later, we still continue to derive important scientific insights form the consequences of this global catastrophe. Here we present the data collected using three animal models chronically e.xposed to substantially elevated levels of irradiation: laboratory mice, natural populations of various species of voles {Microtus arvalis, PROCEEDINGS 90"' ANNUAL MEETING 35 Microtus oeconomus, Clethrionomys glareolus) and experimental herd of cattle. In cattle, the dramatic decrease in the fertility was observed subsequent to irradiation. This observation was compatible with preferential elimination of embryos with radiosensitive genotypes. In dairy breed Holstein cows, there was a change in the structure of population toward the loss of the breed specialization and reversal to genetic characteristics of the priinitive breed, thus, confimiing Shmalgausen’s Rule of the preferable reproduction of the least specialized forms in case of dramatic environmental change. In voles, the spread of radioresistant genotypes/phenotypes through entire populations took approximately 26-30 generations. Thus,, the main consequence of the Chernobyl disaster was observed at the level of populations rather than individuals and manifests through the change in the genetic structure of population due to an increase in the level of the genomic instability. Posters DETERMINATION OF GENOME-WIDE METHYEATION IN NEURONS TREATED WITH AMYLOlD-p. Rebecca Gairett . Courtney McKenzie, Noor Taher, & Gaiy^ Isaacs, Department of Biology and Chemistry, Liberty University, Ly nchburg VA 24502-2269. Alzheimer’s disease (AD) is a form of dementia characterized by the formation of neurofibrillary tangles and amyloid-(3 plaques. Known causes of AD cannot account for the large number of AD cases, so the connection between AD and the epigenome, specifically CCGG genomic loci, is being studied. Several factors make the case for an epigenetic basis for AD. A global change of DNA methylation levels is shown in AD subjects relative to control groups, and several AD-associated genes are regulated by DNA methylation To study the differing levels of methylation in a disease vs. non-disease state, isoschizomer enzymes MspI and Hpall (which cut CCGG regions) were used. Hpall can only cleave if the CCGG is unmethylated, allowing for detennination of methylation status. DNA samples from undifferentiated IMR32 cells (cancerous state), differentiated IMR32 cells (normal state) and amyloid-fl treated differentiated IMR32 cells (AD-like state) were digested using MspI and Hpall. Samples were then concentrated using the HELP assay, fluorescently labeled, and hybridized to a microarray. Genome-wide increases and decreases in methylation of CCGG regions were observed between the cancerous, normal, and AD-like states. Microarray data was used to pinpoint specific genomic regions where the methylation status changed; studies of CCGG regions of these specific genes are currently being conducted. INVESTIGATION AND ANALYSIS OF THE MOLECULAR BIOLOGY AND EVOLUTION OF THE APPETITE REGULATING HORMONE AGOUTI- RELATED PROTEfN (AgRP). C. Gemer'-~ . A. Birerdinc' Z. Younossi* " ^ A. Baranova'-^, & M. Estep', 'Betty and Guy Beatty Center for Integrated Research, Inova Health System, Falls Church VA, "Center for the Study of Genomics in Liver Diseases, Molecular and Microbiology Department, George Mason University, Fairfax, VA and ^Center for Liver Diseases^ Inova Fairfax Hospital. Agouti-Related Protein (AgRP) is an orexigenic peptide hormone that suppresses metabolism. Its role in appetite, metabolism, dyslipidemia, inflammation, and melanogenesis makes the dysregulation of AgRP a likely contributor to metabolic disease. The aim of this research is to 36 VIRGINIA JOURNAL OF SCIENCE compare AgRP DN A and protein sequences, gene structure, and genetic neighborhood across several species in an attempt to identify important regulatory motifs and possibly develop hypotheses regarding their specific function Bioinformatic comparisons using clustering and alignment tools will be used to assess consensus and divergence. Preliminary results have already identified two conserved putative miRNA binding sites; tire putative binding site for hsa-miR-554 is highly conserved in die prunates examined, while the putative binding site for hsa-miR-375 is conserved among all mammals examined but not other species. Our study could offer insights into intervention targets for the regulation of AgRP. FUNCTIONAL ANALYSIS OF PUTATIVE TUMOR SUPPRESSOR GENES KCNRG AND KCTD7. Hannah Choi ’. S. Krishnamurthy' & A. Baranova'’^, 'Biology Department, George Mason University, Fairfax VA, ’Betty and Guy Beatty Center for Integrated Research, Inova Health System, Falls Church VA. KCNRG is a soluble protein with characteristics suggesting it forms hetero-tetramers with voltage-gated K+ channels (K,,) and inhibits tlieir function. However, KCNRG related proteins do not bind (KJ but are associated with ubiquitin ligase cullin 3, suggesting that the function of KCNRG may be different from that hypothesized before. Cullin 3 ubiquitination is suspected to directly modify the activities of K^. KCTD7 gene is a paralog of the KCNRG gene that also binds to cullin 3 .The Oncomine database is an online collection of microarrays that profile various types of human cancer samples. Hundreds of tumor samples are described as a single, co-processed multi-array study to allow analyses of co-expression patterns. Separate analyses of ten different Oncomine datasets for co¬ expression patterns for the top 100 genes co-correlating with KCNRG and KCTD7 were perfomied with CNS samples. The meta-analysis with genes found in 3 or more of the datasets yielded 95 gene hits for KCNRG and 37 for KCTD7. This data was used as input for an advanced analysis using Metacore, an integrated software suite for pathways and network analysis of OMlCs data. The "‘Analyze Single Experiment” workflow in Metacore was employed for the meta-analysis of the data using 650 Canonical Pathways maps. This analysis showed that the top scored map based on the enrichment distribution for genes co-expressed with KCNRG is “Transport_RAN regulation pathway”. The top score map for KCTD7 revealed to be “Cadherin mediated cell adhesion”. Further research is currently in progress. EFFECTS OF NEUROTRANSMITTERS ON THE LOCOMOTION OF TERRESTRIAL SLUG, LIMAX MAXIMUS, Jamie P. Warrick, April C. Nivens, and Brett G. Szymik. Longwood University, Farmville, VA 23909. This project investigates the putative role of various neurotransmitters on the locomotory behavior of the terrestrial slug Umax maximiis. Tune-lapse videography and still photography were used to determine the behavioral effects of administration of serotonin, dopamine, and ergometrine neurotransmitters, as well as a saline control. Pedal wave number and speed as well as overall animal speed were measured after neurotransmitter injection into the body cavity. Serotonin decreased the average number of pedal waves but increased pedal wave speed. Dopamine increased the inter-wave length while decreasing wave speed. Overall, this project begins to hone-in on the neurotransmitters that may be endogenously used to modulate locomotory speed in the terrestrial slug Umax. PROCEEDINGS 90**^ ANNUAL MEETING 37 ROLE OF THYMOSIN BETA4 IN EPITHELIAL TO MESENCHYMAL TRANSITION IN IDIOPATHIC PULMONARY FIBROSIS. C Collins', MLeema^^ E McLaughlin‘s S, Nathan- and G Grant'. 'SSB GMU, Manassas VA, -IITNH Inova Fairfax, Falls Church, VA. The transformation of epithelial cells to mesenchymal cells (EMT) is an important, normal cellular process. However, EMT can also play a role in diseases as seen in metastatic cancer and fibrotic diseases such as Idiopathic Pulmonary Fibrosis (IPF). IPF is a fatal scarring disease of the lung involving deregulated tissue repair. IPF is exacerbated by an over population of fibroblasts and EMT is believed to contributed to this overabundance. Thymosin beta-4 (T|34) is a small (4.9kDa) protein, predominantly involved in the actin cytoskeleton assembly. However, recently additional roles have been attributed to this protein including migration, pro¬ survival/anti-apoptosis and the ability to initiate EMT, We have recently discovered that T(34 is over expressed in IPF fibroblasts. Therefore, here we investigated the potential of the protein T|34 to induce EMT in lung alveolar cells and thereby contribute to IPF. The model alveolar type U cell line A549 was employed. These cells were exposed to 0,5, lOng/ml Tp4 at various serum concentrations over a 7,24, and 72-hour period. In addition stable Tp4 over-expressing transfected A549 cell lines were derived to investigate the effect of endogenously over expressed Tp4. Cells exposed to 0, 5,10 ng/ml transforming growth factor- beta (TGF-P) at 1 % and 10% serum concentrations served as a positive control. EMT was tracked by quantitative real-time PCR (qRT- PCR) and western blotting using markers of EMT such as E-cadherin. (Supported by: The Jeffress Memorial Trust) DEVELOPING A SINGLE STEP DETECTION OF ANTIGEN-ANTIBODY INTERACTIONS IN SOLUTIONS Ekaterina Marakasova' I Alexei Shevelev^ & Ancha Baranova', 'School of Systems Biology, George Mason University, Manassas, VA 20110, USA, and ■ Department of Virology, Moscow State Academy of Veterinary Medicine and Biotechnology, 23 Academika Skryabina, Moscow 109472, Russia. Instant immunodetection of relevant chemical compounds performed by pocket-size devices may be useful in clinical assays as well as in customs and security service, in the product quality control and in environmental monitoring. Moreover, a quality of medical care can be substantially elevated if serological tests for inflectional diseases could be carried out in several minutes, not days. The same advantages are commonly applicable in veterinary practice as well. We propose a detection system based on antigen-induced molecular rearrangements in C2h and Ch3 domains of IgG. This system consists of several artificially designed proteins containing fluorescent moieties. These proteins are readily compatible with any types of available antibodies against infectious agents or other chemical compounds. When a specific molecule is recognized, a fluorescent signal may be detected by eye or by a special mobile device. UNKNOWN BACTERIAL STRAINS IDENTIFIED THAT PRODUCE INHIBITORY PRODUCTS. Grant Waldrop and Dr. Michaela Gazdik, Dept, of Natural Sciences, Ferrum College, Ferrum VA. Three unknown bacterial strains exhibited inhibitory capabilities towards gram-negative and gram-positive bacterial strains through contamination in the lab. Through differential media, metabolic characteristics, stains, and 16 S gene rDNA sequencing the unknown bacterial strains where identified as three different strains of Paenibacilluspolyrnyxa. The antmiicrobials produced by these 38 VIRGINIA JOURNAL OF SCIENCE bacterial strains had an effect on gram-negative and gram-positive bacteria including: Mycobacterium smegrnatis, Escherichia coli, Leifsonia shinshuensis, Proteus vulgaris, Staphylococcus epiderrnidis, Pseudomonas fluorescens, Bacillus cereus, Staphylococcus typhomurium, Pseudomonas aeruginosa, and Staphylococcus aureus, although effectiveness varied. Mycobacterium smegrnatis being a model organism for Mycobacterium tuberculosis research became a target organism of interest. The stability of the unknown antimicrobial/antimicrobials inhibitory factor collected in the TSB broth of cultures was exposed to varying temperatures and its effectiveness was tested on Escherichia coli. The determination of the most viable culture incubation time period for the most effective antimicrobial/antimicrobials was detennined as well. Further details of the unknown antimicrobial/antimicrobials will be eluded through future work along with molecular and genomic origins. NIAID grant number 1R15AI084058-01 LONGEVITY AND NEURONS: MAKING DROSOPHILA LIVE LONGER THROUGH ELECTRON TRANSPORT CHAIN RNAI IN SPECIFIC NEURONAL SUBTYPES. Betliany J. Jolinson . Charise J. Garber, & Jeffrey M. Copeland, Eastern Mennonite University, Department of Biology. Over the past few years several genetic screens have isolated genes important for determining lifespan. Genes for the electron transport chain can dictate lifespan when partially inhibited in neurons and various other tissues. We have conducted tissue specific genetic inhibition of the ETC, and have observed that ETC inhibition in motor neurons is sufficient for lifespan extension. Impoilantly, ETC inhibition specific to intestines and glutamatergic neurons fail to extend lifespan. These results point to an important role of motor neurons in longevity. A DROSOPHILA MUTANT RESISTANT TO OXIDATIVE STRESS. Charise J. Garber & Jeffrey M. Copeland, Eastern Memionite University, Department of Biology. While oxidative damage is known to play an important role in the aging process and the re-oxygenation after an ischemic stroke, the molecular mechanisms are still poorly known. To better understand the cellular response to oxidative stress, we have conducted an X chromosome screen in Drosophila to find mutants resistant to elevated oxygen levels. The mitochondrial gene CG7772 showed increased resistance to hyperoxia, but not to paraquat, another reactive oxygen species generator. Mutants for CG7772 do not confer resistance to general stressors as CG7772 females do not resist starvation. THE PSEUDOPHOSPHATASE MK-STYX ROLE IN NEURONAL DIFFERENTIATION. K. E. Wong & S. D. Hinton, Dept, of Biology, College of William and Mary. The pseudophosphatase MK-STYX [MAPK (mitogen-activated protein kinase) phosphoserine/threonine/tyrosine-binding protein] has been previously implicated to cause neuronal differentiation. MK-STYX is structurally similar to the MAPK protein family, whose proteins are involved in pathways regulating cell proliferation and differentiation. We hypothesized that MK-STYX plays a direct role in neuronal differentiation. To determine if MK-STYX has a role in neuronal differentiation, PC 12 cells were transfected with pMT2, MK-STYX-FLAG, and pEGFP vectors. Cells were examined and scored 5 days post-transfection. Here, we show that MK- STYX is endogenously expressed in PC12 cells. Furdiermore, over- PROCEEDINGS 90“^ ANNUAL MEETING 39 expression of MK-STYX encourages neurite production. Neurite expression is seen in the presence and absence of NGF, neiTe growth factor. Finally, MK-STYX can induce neurite outgrowth when MEK is inhibited. Together, these data are significant because they provide more insight into MK-STYX’s potential role in neuronal differentiation. Future directions should explore other proliferation and differentiation patliways to determine MK-STYX’s role. Biomedical and General Engineering VARIABLE CRACKING PRESSURE SWING CHECK VALVE. Cameron J. Grover , Samantha L, Leach , Graham S. Kelly, Stephen J. Warren, Charles E. Taylor & Gerald E. Miller, Dept, of Biomedical Engineering, Virgmia Commonwealth University, Richmond VA. 23220. Aortic Valve Sclerosis is a heart condition affecting up to thirty percent of the population over the age of sixty-five. It is characterized by a calcification of the aortic valve leaflets. If the condition is left unchecked, it can lead to aortic valve sclerosis, which may significantly impede blood flow to the heart. This leads to an increased left ventricular load and an increased pulse pressure, both of which may cause complications and undue stress on the body. This project models aortic valve sclerosis by developing a variable cracking pressure swing check valve. Using laser printed acrylic of quarter-inch thickness, a casing for the valve was built with openings comparable to that of a sclerotic valve, The valve was built with sixteenth-inch thick acrylic and pivots on a pin hmge. The elastic material Thera-band Silver was affixed to the valve and attached to a linear-actuator. The Imear-actuator pulls the strip of Thera-band, making it more difficult for the valve to open. In future studies, this model can be used in mock circulatory loops to test left ventricular assist devices interaction with pathological valve states. IN VITRO STEREOSCOPIC FLOW INVESTIGATION OF A TILTING DISC VALVE AT AN AORTIC ROOT MODEL. Stephen J. Warren . Graham S. Kelly, Charles E. Taylor, Gerald E. Miller., Dept, of Biomedical Engineering, Virginia Commonwealth University, Richmond VA. 23220. Currently, bench top experimental fluid mechanics study for biomedical applications require physiologically accurate flow and geometries. Because of this, it was necessary to include working anatomical models in tlie mock circulatory systems bemg used to simulate cardiovascular hemodynamics. The first step in this process was a rigid model of the aortic root, which would serve as accurate exit geometry from the aortic valve. An acrylic aortic model was created from cryoslice data from the National Library of Medicines Visible Human project. The model was implemented into an automated mock circulatory loop that would provide the downstream resistance and compliance to create relevant flow patterns. A tilting disc valve (Bjork-Shiley®) was used in this experiment to display the effects of a central occluder on the exit flow of the valve into the aortic root. Stereoscopic Particle Image Velocimetry was included to allow for three velocity components to be taken in to account at once rather than a multi-planar comparison. The studies concluded that the large central occluder design confirms the presence of large low flow regions in the sinuses of the aortic root. These flow patterns could result in thrombosis formation in coronary sinuses, which could result in myocardial infarction if coronary flow becomes interrupted. 40 VIRGINIA JOURNAL OF SCIENCE PHOSPHOLEMMAN IS A NEGATIVE FEED-FORW ARD REGUEATOR OF CA^^ IN B-ADRENERGIC SIGNALING, ACCELERATING B-ADRENERGIC INOTROPY Jason H. Yang & Jeffrey J, Saucemian, Dept, of Biomedical Engineering, University of Virginia, Charlottesville VA 22903. Sympathetic stimulation enhances cardiac contractility by stimulating (3-adrenergic signaling and protein kinase A (PKA). Recently, phospholemman (PLM) has emerged as an important PKA substrate capable of regulating cytosolic Ca""^ transients. However, it remains unclear how PLM contributes to p-adrenergic inotropy. Here we developed a computational model to clarify PLM’s role in the p-adrenergic signaling response. Simulating Na^ and sarcoplasmic reticulum (SR) Ca^^ clamps, we identify an effect of PLM phosphorylation on SR unloading as the key mechanism by which PLM confers cytosolic Ca'^ adaptation to long-tenn p-adrenergic receptor (p-AR) stimulation, Moreover, we show phospholamban (PLB) opposes and overtakes these actions on SR load, forming a negative feed-forward loop in the p-adrenergic signaling cascade. This network motif dominates tlie negative feedback conferred by p-AR desensitization and accelerates p-AR-induced inotropy. Model analysis tlierefore umiiasks key actions of PLM phosphorylation during p-adrenergic signaling, indicating that PLM is a critical component of the fight-or-flight response. SUCCESS OF FLATFOOT SURGICAL CORRECTION ON PLANTAR PRESSURE DISTRIBUTION. Erika A Matheis . Edward M Spratley, Charles W Hayes, Robert S Adelaar & Jennifer S Wayne, Virginia Commonwealth University, Richmond VA. Adult Acquired Flatfoot Deformity (AAFD) is a progressive disease affecting the soft tissue structures of the foot in which Joint alignment degenerates and significant dysfunction results. This pre-operative/post-operative study focused on the plantar pressure foot patterns of both stance and walking of AAFD participants to detemiine the effectiveness of surgical correction. The pressure pattern was divided into nine regions, from toes to heel and medial to lateral, with peak pressure and % body weight loading in each region calculated. Arch index was also determined to quantify flatness as the area of midfoot loading relative to the entire foot. Additionally, participants completed two health questionnaires (SF-36 and FAOS surveys). A lateral shift in pressure loading was evident post-operatively in both the forefoot and midfoot regions. Scores on both surveys increased post-operatively. Arch index was inconclusive, Clinically, plantar pressures as well as surveys may be useful to assess the success of the surgical technique for AAFD. SEARCH ENGINE OF PHYSIOLOGICAL CONDITIONS IN THE PHYSIOBANK DATABASE. Nitin S. Panwar . Graham S. Kelly, Charles E. Taylor & Gerald E. Miller, Dept, of Biomedical Engineering, Virginia Commonwealth University, Richmond VA. 23220. PhysioBank is an open source database where patient information from multiple sources is collected. The patient data of interest to this laboratory is the blood pressure wavefonn data and physician amiotations pertaining to pathological events that occurred during data collection. However, the size of the library (27000 files) makes it difficult to locate files of interest. This Matlab program has been implemented to sort and categorize these files to make relevant data easily accessible. A search of the databases was perfomied to obtain a list of files that contain blood pressure waveform data. This list is then compared against every annotation (57) PROCEEDINGS 90**^ ANNUAL MEETING 41 in the PhysioBank approved annotation list to filter for records that contain pathological events; yielding 3700 records. The list is filtered to include only the databases of interest (Mimic 1, Mimic II, MGH/MF, Fantasia, SLPDB); as these databases have the most complete waveform data. Fmally, the records are narrowed to create a unique download list of individual files each with a physiological annotation (1990 records). This method provides a faster alternative to the Waveform Database (WFDB) toolbox for Matlab, as it accesses the database information directly from the website. It delivers functionality not seen in the WFDB tools through the identification of blood pressure waveform records containing specified annotations. This projects assists the current work of identifying gold standards for pathological event effects on blood pressure waveforms. FINITE ELEMENT ANALYSIS OF TRANSVERSE MEDIAL MALLEOLAR FRACTURE FIXATION. Ruchi D, Chande . John R, Owen & Jennifer S. Wayne, Virginia Commonwealth University, Richmond VA. Fracture of the medial malleolus, or distal end of the tibia, can occur in pronation loading scenarios. If such ankle injuiy is left untreated, more severe conditions such as osteoarthritis can result. Via various devices, open reduction/internal fixation (ORIF) maybe utilized to secure the malleolar fragment to the proximal tibia. In this study, finite element analysis (FEA) was employed to investigate transverse fracture fixation by two cancellous screws or a relatively newer fixation device known as the Medial Malleolar Sled^'^. The performance of these two devices in both tension and torsion was first assessed during cadaveric testing. Following experimentation, SolidWorks was used to develop a computer model of the study, and this model was then validated against experimental results by perfonning FEA. Force, torque, and displacement results demonstrated the validity of the models, and stress analyses were successful in predicting regions of failure corresponding to those observed during experimentation. Such results illustrate the general utility of computational modeling for the investigation of biomechanical systems. DESIGN OF A COMPUTATIONAL MODEL FOR ELBOW JOINT BIOMECHANICS. C. A. Woodcock . E. M. Spratley & J. S. Wayne, Orthopaedic Research Laboratory, Virginia Commonwealth University, Richmond VA 23284. Computational modeling is an effective but underutilized method to study the biomechanics of joints, It provides a high degree of adaptivity and reproducibility, while enabling the uivestigatorto study parameters such as stress, strain and forces that are not easily measured otherwise. Using computed topography scans of a cadaver specimen and Mimics™ (Materialise) software, tliree-dimensional representations of bony anatomy were created using masking and remeshing tools. A functional computational model of the elbow was then developed using the commercially available software package SolidWorks"^. Soft tissue constraints were defined and modeled using osteoarticular surfaces and in situ strains. The model was validated through an abbreviated reproduction of the cadaver study Hull et al (2005), which explored the effects of coronoid process resections on varus stability of the elbow. Thus, it was shown that the model accurately represented elbowjoint biomechanics via physiological movement and quantitative constraining loads during applied perturbations tliroughout a range of motion. F urther expansion upon the computational 42 VIRGINIA JOURNAL OF SCIENCE model will focus on radial head contributions to stability, as its effects are under researched despite being the secondary constraint against valgus instability, REAL-TIME DIGITAL SIGNAL PROCESSING OE MOCK CIRCULATORY LOOP PRESSURE SENSOR DATA USING AN XPC TARGET SOLUTION. Robert B. Thompson . Charles E. Taylor & Gerald E. Miller, Dept, of Biomedical Engineering, Virginia Commonwealth University, Richmond VA. 23220. Real time analysis and control of a mock circulatory loop is highly desirable. Mock Circulatory loop experimentation involves e.xtensive analysis of the cause and effect relationship between many parameters, including pressure at determined points in the mock circulatory loop. Real time analysis allows for dynamic experimentation; high frequency iterative acquisition of parallel sensor data with automatic or host operator controlled response of control of mock circulatory loop parameters. A National Instruments Embedded Controller, operating a parallel Input/Output device, under the LabVIEW Real-Time Kernel is proposed as an xPC target to run a LabVIEW Virtual Instrument (VI) to accomplish dynamic mock circulatory loop experimentation. A VI consisting of an eight Elertz timed loop and network published variables is created to acquire pressure sensor data from a mock circulatory loop. Pressure sensor voltage, acquired at 512Hz, is mathematically manipulated as a dynamic data type on the xPC target to detennine real time measurements of cardiac output and total peripheral resistance. The network published variables are read and displayed by a host computer, allowing for operator monitoring and control. An xPC target will perform mock circulatory loop signal processing and control outside of a PC operating system environment, enabling high frequency sampling, up to IMHz, and unloading the processor requirements of the PC. APPLICATION OF SIMULINK CODER™ TO A COMPUTATIONAL MODEL OF A SYSTEMIC MOCK CIRCULATORY LOOP. Charles E.Tavlor «SL Gerald E. Miller. Dept, of Biomedical Engineering, Virginia Commonwealth University, Richmond VA 23220. Mock circulatory loops provide an essential in vitro assessment tool for evaluating cardiovascular devices through their operation as a hydraulic analog to the human circulatory system. A computational model of this physical system enables experimental settings to be pre-determined, which assists the efficiency of in vitro experimentation. The development of computational models has been traditionally an intensive programming effort. Utilization of Simulink® Simscape™ toolboxes expedites the model construction process and yields a high fidelity computer model. However, these pre-constructed physical modeling components are computationally intensive. The simulation times for large models may take longer than the experimental run time in the mock circulatory loop. Simulink Coder™ can accelerate these models by compiling the code into more efficient C code, which can be executed more efficiently outside of the Matlab® runtime environment. Various levels of the Simulink Coder'^^ (Accelerator, Rapid Accelerator, Rapid Accelerator Standalone) provide improvements in execution, and the approach of each level in code packaging will be discussed. The impact of the acceleration on a computational model of a mock circulatoiy loop will be discussed with a focus on the topology of the model and what sections prevented simulation time reduction. PROCEEDINGS 90**^ ANNUAL MEETING 43 DESIGN OF AUTOMATED DETECTION OF INCOMPLETE EMPTYING FROM VENTILATOR GRAPHICS: EVALUATING THRESHOLD VALUES. Nvimas Y, Isti ArieT Curtis N. Sessler, Paul A. Wetzel, and Mary Jo E. Grap, Dept, of Biomedical Engineering, Virginia Commonwealth University. Auto-PEEP stemming from incomplete emptying of breath uilialation is an undesired excessive pressure in the lungs of patients on invasive mechanical ventilator has been a hidden presence drat hinders optimal care. Noninvasive indicator for the presence of auto-PEEP is known to those who special ize in ventilator graphics whom are veiy rare. Incomplete emptying of the breath indicative of auto-PEEP can be automatically detected through a computerized algorithm. Two distinct algorithms have been developed, the first being dependent upon pressure waveform and the second is evaluating flow waveform independent from pressure. Both algorithms are dependent upon varying threshold values. For one criterion of the threshold, the first algorithm yields a sensitivity of 84.7% and specificity of 92.6%, and the second algorithm yields sensitivity of 90.1% and specificity of 82%. Tliresholds are adjustable for finding the optimum rate of detection for incomplete emptying that can eventually be used for an automated detection of auto-PEEP. HIGH-LEVEL GPU COMPUTING IN MATLAB®: TWO CASE STUDIES OF ACCELEREYES JACKET IN BIOMEDICAL ENGINEERING APPLICATIONS. Graham S. Kelly . Charles E. Taylor & Gerald E. Miller, Dept, of Biomedical Engineering, Virginia Commonwealth University, Richmond VA. 23220. Graphical Processing Units, or GPUs, have emerged as important scientific computing tools due to their ability to handle computationally intensive algorithms in parallel, providing drastic reductions m execution time. As die demand for GPU acceleration has increased, higher-level computing languages have emerged to streamline the process of memory transfer to and from the device and executing custom kernels (e.g. CUDA, OpenCL). AccelerEyes Jacket, a GPU computing environment for MATLAB®, provides the very-high-level functionality of MATLAB® with speed and overhead superior to the native MATLAB® Parallel Computing Toolbox'*''^. We illuminate the usefulness of Jacket through two differently staictured Particle Image Velocimetry algorithms, which track particle displacement in moving fluid. These algorithms show marked improvements in execution time with minimal changes in code between the CPU and GPU variants. Botany THE EFFECT BY HYDROLOGIC REGIMES AND SAHDE ON ATLANTIC WHITE CEDAR {CHAMAECYPARIS THYOIDES) GROWTH IN THE CAVALIER WILDLIFE MANAGEMENT AREA IN CHESAPEAKE, VIRGINIA Justin L. Weiser . Jackie Roquemore, & Robert B Atkinson, Department of Organismal and Environmental Biology, Christopher Newport University, Newport News VA, 23606, The Virginia Department of Game Inland Fisheries began restoring a 1538-ha Atlantic white cedar (AWC) Swamp in Chesapeake, Virginia m2007. Reestablishment of AWC is critical in restoration of this globally- threatened ecosystem. The purpose of this study is to compare morphometric parameters of two tree planting types, propagated seedlings and rooted cuttings, at two locations characterized by hydric and mesic 44 VIRGINIA JOURNAL OF SCIENCE hydrologic regimes, which were assigned via prevalence index of wetland indicator status for non-cedar vegetation. In August 2010 and 2011, field crews quantified survivorship and gro\vth (estimated by height, canopy diameter and stem diameter), and shade intensity at each location. Data were analyzed using t-tests and linear regressions. Growtli was significantly greater (p<0.05) for rooted cuttmgs than for propagated seedlings over one growing season and shade negatively unpacted all growth indices. Growth in hydric hydrologic regime for all three morphometric parameters was less than in mesic plots {p <0.05). Rooted cuttings had greater mean growth than propagated seedlings and shade is greater in the hydric plots. Reestablishment of AWC may be effective in sites that have a prevalence index of between 2.5 and 3.5; however, mesic sites might lack the self- maintenance capacity in that seeds could be destroyed by fire. THE FLORA OF VIRGINIA PROJECT; A 2011 -2012 UPDATE. MarionB Lobstein . (Retired) Dept, of Biology, Northern Virginia C.C., Manassas, VA 22205, Virginia, for its landmass, has the most diversity of vascular plant species of any state in the United States. The colony of Virginia had the first flora, of any of the 13 colonies, the Flora Virginica in 1739 and last updated 250 years ago in 1762, yet Virginia does not have a modem The Virginia Academy of Science for over eighty years has supported efforts to produce a modem Flora of Virginia. In 2001 the Foundation of the Flora of Virginia (FFVP), Inc, was formed and by May 2002 received 501(c) 3 status. Since 2001 both the Academy and the Fellows have generously given both financial and moral support to FFVP in the development of a modern Flora of Virginia. The publication date of the Flora of Virginia by the FFVP is December 2012. BRIT (Botanical Research Institute of Texas) Press will be the publisher. The Flora of Virginia will be a 1,500 page manual describing and aiding in the identification of the 3,200 species of vascular plants that are native or naturalized in Virginia. SOIL COMPOSITION IN TFIE GREAT DISMAL SWAMP; BEFORE AND AFTER FIRE. Kristina M. Kowalski . Jackie Roquemore & Robert B. Atkinson, Christopher Newport University. The physical and chemical properties of peat soils are influenced by fire and may effect regeneration of native species, such as Atlantic white cedar (AWC) in the Great Dismal Swamp National Wildlife Refuge (GDSNWR). This study was conducted to determine soils changes associated with the 2008 South One Fire. In 1999 soil samples were collected from GDSNWR AWC stands that had not burned in at least several decades including 27 plots in 3 stands. In the summer of 2011, samples were collected from 21 plots m 5 AWC stands that burned in the 2008 South One Fire and 2 stands eontaining 7 plots that were unburned. Soil samples for all years and plots were collected at 10 cm depth and AWC needle samples were also collected from the 2011 plots. Grand mean bulk density increased from 0.148 g cc~‘ to 0.214 g cc~^ in burned, and 0.173 g cc~‘ in unburned stands. Grand mean carbon remained near 47.5% across all treatments. Total nitrogen increased, but in both burned and unburned stands. There were no clear trends in AWC tissue total nitrogen content. ATLANTIC WHITE CEDAR REGENERATION IN THE GREAT DISMAL SWAMP. Shawn J. Wurst. R. B. Atkinson & J. D. Roquemore, Department of Organismal and Environmental Biology, Christopher Newport University, Newport News VA 23606. A peat-based seed bank underlies many East Coast Atlantic white PROCEEDINGS 90“^ ANNUAL MEETING 45 cedar (AWC) swamps, and this globally-threatened ecosystem exhibits self¬ maintenance through high rates of natural regeneration after a stand-clearing fire. AWC stands in the Great Dismal Swamp have been in decline for approximately 200 years at least in part due to the draining of water by ditches. In this study we report the amount of regeneration of AWC in the Great Dismal Swamp after the South One Fire of 2008. For regeneration in 8-m' plots during 2009 and 2010, regenerants were counted in 143 and 41 plots, respectively. Mean regeneration in 2009 (26,500 ± 23,800 stems ha-1) was not significantly different than in 2010 (29,300 ± 38,000 stems ha-1, Paired t-Test P=0.315). Regeneration rates suggest that most regeneration occurred in the first year after the fire. Regeneration rates reported in the literature were much higher for natural cedar swamps and the lower regeneration rate in the current study might be the result of low water tables coincidental with the 2008 fire. ANTIOXIDANT ANALYSIS OF SPICES FROM THE APIACEAE. R. A. McNeive and M. H. Renfroe, Dept, of Biology, James Madison Univ., Harrisonburg VA 22801. Antioxidants in one’s diet are an important component of protection from cellular oxidative damage, effects of overall aging, and certain diseases such as some fonns of cancer. Spices from plants have been shown not only to have antimicrobial properties, but also to contain potent concentrations of antioxidants. One plant family, the Apiaceae, has provided more spices to the human diet than perhaps any other single plant family. Therefore we analyzed the antioxidant content of seven of the spices from Apiaceae to establish an intrafamilial comparison. Results indicated these spices contained greater quantities of hydrophilic antioxidants than lipophilic antioxidants. Fermelj cumin and dill contained the greatest quantities of hydrophilic antioxidants, while celery contained the greatest quantity of lipophilic antioxidants. Fennel, cumin and dill contained significantly greater concentrations of total antioxidants compared to celery, anise, which were not statistically different from one another, but which were significantly greater tlian caraway, which was significantly greater tlian coriander. Analysis of these spices will increase our understanding of the intrafamilial variation in antioxidant production by plants and also provide valuable information for dieticians interested in considering antioxidants as a dietary component. From this, there were no large differences between fresh weight measurements and dry weight measurements of the spices. Celery was found to be no different than anise regarding antioxidants. Cumin was found to be equal to dill and fennel while caraway and coriander were each different from the other spices. INTERACTIVE EFFECTS OF ALLELOPATHY, PHOTOPERIOD, AND TEMPERATURE ON THE GROWTH OF CUCUMIS SATIVUS. Catherme Daniels & Maiy E. Lehman, Dept, of Biological and Environmental Sciences, Longwood University, Farmville VA 23909. Allelopathy involves the interaction of plants through the release of chemicals into the environment, often negatively affecting the growth of surrounding plants. Little is known about how variability in environmental factors interacts with allelopathy. Cucumber seedlings were grown in nutrient culture systems containing 0-0.8 mM ferulic, p-coumaric or salicylic acid, three common allelopathic chemicals. The seedlings were also exposed to either a 6- or 12-hour photoperiod and to either variable or constant temperatures, Some significant interactions were seen, but were not consistent across all allelochemicals and environmental conditions. The 46 VIRGINIA JOURNAL OF SCIENCE strongest effects were seen with the reduction in allelopathic effects of salicylic acid under lower temperatures and shorter photoperiods, even when light intensity was adjusted to maintain equivalent total energy supply. Additional experiments suggest that the significant interaction is only between allelopathy and temperature. APOMIXIS IN A PISTILLATE CLONE OF FLUEGGEA SUFFRUTICOSA (PHYLLANTHACEAE). Jessica Kelly & W. John Hayden, Department of Biology, University of Richmond, Richmond, VA 23173. Pistillate specimens of Flueggea sujfruticosa, dioecious shrubs native to temperate Asia, produce viable seeds in the absence of pollen. First (spring) flowers abort shortly after anthesis but some later (summer) flowers form fruits with apomictic seeds. Summer flowers, fruits, and seeds from plants cultivated in central Virginia were studied via light microscopy to document development of apomictic seeds, Ovules are hemitropous, bitegmic, crassinucellate, with nucellar beaks and obturators. Embryo sacs abort shortly after anthesis; nevertlieless, many ovaries and ovules persist and grow despite absence of embryos. The hypostase region is responsible for some post-antliesis growth of unfertilized ovules but no apomictic embryoids were observed in this region; approximately 90% of these abort after enlarging three times greater than their size at anthesis. In about 10 % of post-anthesis ovules studied, adventitious embryony initiates catwo weeks post anthesis via mitotic proliferation of nucellus cells located in the general vicinity of the former egg apparatus. Early apomictic embryoids are irregular masses of cells; ordinaiy basal cells and suspensors cannot be distinguished. Mature apomictic seeds possess bi-layered sclerified testa and straight dicotyledonous embiy^os sun'ounded by relatively empty nucellus cells; only one apomictic seed studied possessed densely cytoplasmic nucellus cells. This is the first report of apomixis in Phyllanthaceae. POLLINATOR PREFERENCE BASED UPON ULTRAVIOLET CUES. L. Abbott & L. Horth, Dept of Biology, Old Dominion University, Norfolk, Va. 23529. Pollinators are responsible for 1/3 of all the food that hmnans consume. This accounts for 15 billion dollars in food crops annually. LJltraviolet Cues are a way to attach pollinators to these crops. Ultraviolet cues are ray that are emitted from the sun and absorbed by the petals of the plant producing a black ring. Two experiments were preformed one on Rcluhekia hirta and one on Ranunculus sp In both of these experiments bees were monitored for there preference between large UV cues and small UV cues. In the R. hirta experiment tliree flower types were used; an enlianced flower (90% of the flower petal had an ultraviolet cue), a cut and paste control flower (roughly 45% cue), and an unmanipulated flower (roughly 45% cue). This same manipulation was done in one of the subset experiments for the buttercup. The other subset of the Runculus experiment was monitoring natural UV cues to see if the small margins in UV had an effect on what flowers bees chose. In all experiments the pollinators showed preference to the large Ultraviolet cues. Pollinators chose the large ultraviolet cues in; wild R. hirta, cultivated R. hirta, unmanipulated Ranunculus and enhances Ranunculus. Regardless of the species and treatment of the plant when the flower had a larger Ultraviolet cue pollinators chose this cue more often than a smaller UV cue. Due to the recent decline in bees, knowing what bees chose to pollinate can be a solution to sustain more crops, PROCEEDINGS 90**^ ANNUAL MEETING 47 ANTIOXIDANT ANALYSIS OF COMMERCIAL SPICES. D. Killeen and M. H. Renfroe, Dept, of Biology, James Madison Univ., Harrisonburg VA 22801. There is a growing awareness of the role of antioxidants as an important component of human health. Antioxidants have been implicated in preventing degenerative diseases such as cancer, cardiovascular and neurological diseases, and reducing the effects of aging. Spices have long been part of the human diet and are known to have antimicrobial properties. We investigated eleven spices from around the Mediterranean, southern and southeastern Asia, and the West Indies. Cloves (823 pmol TE/g dw) and cinnamon (387 pmol TE/g dw) contained the greatest hydrophilic antioxidant content. Sage (68 pmol TE/g dw) and rosemary (60 pmol TE/g dw) contained the greatest lipophilic antioxidant content. Overall, cloves (835 pmol TE/g dw) and cinnamon (397 pmol TE/g dw) contained the greatest total antioxidant content. Other spices analyzed were oregano, mint, marjoram, allspice, ginger, allspice, and turmeric. Results indicated that spices are very potent sources of antioxidants and can complement one another to provide a variety of antioxidant molecules. Spices can complement other dietary components such as fruits and vegetables to greatly increase available dietary antioxidants. REHABIEITATION OF RARE SPECIES POPUEATIONS. ErinGillin k Stephen W. Fuller’ & Phillip Sheridan^, ’University of Mary Washington, “Meadowview Biological Research Station. Cell tissue culture of plant seeds has been used in previous research for horticultural and commercial purposes. This study focuses on successful seed propagation for the restoration of a variety of rare and endangered species. A standard tetrazolium test was used to determine the viability of the seeds. Platanthera blephariglottis (Willdenow) Lindley, white-fringed orchid, and Tetragoriotheca helianthoides L., pinelands nerve-ray, seeds were used for both cell tissue culture and soil planting propagation. In cell tissue culture the seeds were sown aseptically on nutrient full media and stored in sealed sterile bags. Orchid protocorm development was expected, but only one vessel withstood contamination long enough to see some growth before also becoming contaminated. Failure in the aseptic processes caused loss of results for the project. Additionally, no growth was seen in the soil flats. This procedure has been successful in previous research, so we suggest further development of the methods to decrease contamination growth. With attention paid to sterile technique, plantlet development should be attainable in tissue culture for application for large scale production and wild population restoration. Further work with seed stratification and soil types is also recommended. Chemistry ASSESSMENT OF GUIDED INQUIRY IN GENERAE CHEMISTRY TABS: A THREE YEAR PROJECT. Heather N. Anthony & Jack K Steehler, Department of Chemistry, Roanoke College, Salem VA 24153.This project investigates student improvements in chemistry laboratories when guided inquiry experiments are added. The project investigated student anxiety levels, content learning, and student perceptions of instruction. Three years of General Chemistry 111-112 were analyzed; the first year studied included mostly cookbook experiments, while years two and three 48 VIRGINIA JOURNAL OF SCIENCE included a mixture of eookbook and guided inquiry experiments.Lab anxiety decreased after eompleting the eourse.The years in which guided inquiry experiments were incorporated saw a smaller decrease in anxiety about time availability. Students gained content knowledge during each experiment, regardless of pedagogy. For most experiments in which pedagogy changed, student content learning did not change significantly when the guided inquiry format was used. Students perceived designing experiments yourself as least helpful to their learning; however, as guided inquiry was added, their perception of helpfulness on this topic increased. This study was funded by the National Science Foundation. COMPUTATIONAL EVALUATION OF SILICON-BASED HIV PROTEASE INHIBITORS, Chynna Blaker , Eatricia Bowman, Vietoria Parker & Wondwossen Arasho, Dept, of Chemistry and the Center for Biotechnology and Biomedical Sciences, Norfolk State University, 700 Park Avenue, Norfolk, VA 23504. There is no known cure for HIV/AIDS and it is imperative to develop a drug that will prevent the replication of the virus, without the stressing concern for resistance. Scientists across the globe struggle to create a mechanism that will slow down the mutations of the virus and suppress viral load in the infected human.This study foeuses on HIV-1 inhibition therapy and utilizes the drug Nelfinavir (Viracept®) as a starting platform for preparation of a newly improved silicon-based drug. S YBYE software was used to test and compare the effectiveness of Nelfinavir against the silanediol analogue and other modified silanediol analogues. The original silanediol analogue (4.48p/l) proved to more effeetive than Nelfinavir (2.68p/l) according to the Surflex doek calculations from the SYBYE software. Silar.sfiiot of NelfirjvLi THERMODYNAMICS OF THE SN2 VERSUS E2 COMPETITION. Charles M. Bump . Department of Chemistry, Hampton University, Hampton, VA 23668. Reactions between alkyl halides and strong bases give a mixture of both substitution (Sn 2) and elimination (E2) products. The major product is usually discerned by students of organic chemistry on the basis of rote memorization of generalizations such as “2° halide plus strong base = elimination”. The “answer” is technically correct, but an analysis of the factors that influence the major product is frequently sacrificed in favor of a quick answer to a complex question. Thermodynamies and kinetics are two major driving forces for organic reactions. We will describe how calculated thermodynamic properties (Gaussian 98, B3EYP) predict whether substitution or elimination is favored in these reactions. THERMAE DECOMPOSITION OF METAE HYDROXIDES, A.Bagley, G.Berman & T C. DeVore . Dep. of Chemistry and Biochemistry James Madison University, Harrisonburg VA 22897. Serious concerns about the quality of decomposition dynamics measurements obtained using standard thermal analysis methods have been PROCEEDINGS 90**^ ANNUAL MEETING 49 expressed over the past 25 years. The thermal decomposition of Al(OH )3 has been investigated under a variety of experimental conditions to further explore the cause of these concerns. The results of these investigations indicate that while analysis using standard techniques such as those developed by Ozawa, Kessinger, and others appear to give describe the dynamics well, tliey give different answers as experimental conditions change. For example, die apparent activation energy mcreases by ~ 10 kJ mol ' is decreased from 10 mg to 0 mg (determined by measuring the dynamics at several sample masses and extrapolating to zero mass). These results clearly indicate that this decomposition does not follow a one step mechanism and clearly indicate the need to use several sets of experimental conditions to determine the reaction dynamics for the process. 3,4:3’,4’-BISBENZO[B]THIOPHENE AND RELATED DERIVATIVES: SYNTHESES AND INVESTIGATION OF THEIR ELECTRO-OPTICAL, CHELATING, AND BIOLOGICAL PROPERTIES. Marissa L. Estep. Diego S. Suarez Boscan, Matdiew VanTil, Zachar>^ R. Rliodenizer, GarthMcGibbon & Michael R. Korn, Dept, of Biol. & Chem., Liberty Univ., Lynchburg, VA 24502. 3,4:3’,4’- Bisbenzo[/dthiophene (BBT) was prepared following a published patent protocol. Molecular modeling computations of BBTcalculated itsbandgap (i.e. the energy difference between the HOMO and of LUMO) to be 3.61 eV (343 nm) (DFT, B3LYP, 6-3IG* ); to test for the accuracy of these computations, UV-vis spectroscopy of BBT was perfoiTned. The resultingspectrum (in dichloromethane) showed two maxima at approximately 383 nm and 365 nm, and two smaller peaks at 349 nm and 332 nm (shoulder); the UV-vis cut-off wavelength was at396 nm (3.13 eV). BBT was tested for intercalation into DNA because of its planar structure, Agarose gels were run in the presence of BBT and a DNA ladder (0.5-10 kb); however, no intercalation of BBT was observed as determined by the absence of fluorescence when gels were exposed to wavelengths of 254 and 365 nm; additional experiments are planned to further investigate the interaction of BBT with agarose gels as well as with DNA. BBT was also tested for antibacterial activity because of its two sulfur atoms; two strains of Pseudomonas aeruginosa were investigated which were grown in the presence of smal 1 paper discs soaked with BBT (from water and from DMSO). No growth inhibition was observed. Chelating properties are still under investigation as well as improved synthetic pathways to increase yields and reduce overall synthetic steps.(Supported in part by a $500 award from the Virginia Academy of Science). A LUMINESCENCE DEMONSTRATION REACTION. Susan Hannegan & H. Alan Rowe, Department of Chemistry, Norfolk State University, Norfolk, VA 23504. Luminol (CsHyN^O,), also known as o-aminophthalylhydrazide, 5-amino-2,3- dihydro-l,4-phthalazinedione,and 3-aminophthatichydrazide, is used in popular luminescent chemical demonstration reactions as well as in forensic science for the detection of blood. Luminol added to a metal catalyst in a basic solution is oxidized resulting in the release of energy as light (maximum wavelength of 424 nm). Light from the oxidation of luminol is the basis for a sensitive method for the detection of blood. A popular chemistry' luminescent lecture demonstration involves the addition of two solutions in the dark creating a dramatic glow. In one popular version, the solutions are noted as “A-1”, consisting of luminol, in a complex salt solution, and 50 VIRGINIA JOURNAL OF SCIENCE “A-2” a hydrogen peroxide solution. To establish the optimum conditions for this reaction each component wasvaried and the response evaluated using a computer- interfaced light sensor. De-oxygenation of both solutions resulted in an increase in both intensity and hal f-life presumably due to tire elimination of quenching. Inclusion of cobalt mstead of copper as the metal catalyst mcreased bothparameters. Alteration of the hydrogen peroxide concentration did not significantly improve the results, while exclusion of some components had a reciprocal effect: increasing intensity and decreasing half-life (sodium bicarbonate) and vice versa (sodium carbonate). OYSTER RESTORATION AND WATER QUALITY ANALYSIS IN AN URBAN SUB-ESTUARY. Melinda Hopper . MatthewBoyce, & Dr. Maury Howard, Chemistry Department, Virginia Wesleyan College, 1584 Wesleyan Drive #B314, Norfolk, VA 23502. This study was conducted to monitor a local body of water and to determine the effect of oysters on water quality, The puipose is to determine whether oyster restoration can help the quality of the water and whether tliis site is an ideal location for restoration. Water samples were collected over a year long period at 3 different sites. Each sample was tested for various water quality indicators, including chlorophyll a, total phosphorus, temperature, pH, BOD and salinity. Sediment samples and oyster tissue samples were also collected and run through an ICP-MS to identify the toxic metals found within them. High concentrations of lead, mercury, arsenic, and other heavy metals were some of the main components. The water contained very low levels of metals due to the tidal influence. However, the sediments and oyster tissue contained high concentrations of many of them, showing the effects of bioaccumulation. It also shows the value of the oysters as filters for the system, removing toxins and nutrients from the ecosystem. NEW SULFONE-DERIVATIVE PHEN YLENEVIN YLENE-BASED CONJUGATED POLYMERS FOR OPTOELECTRONIC APPLICATIONS. Thuong H. Nguven & Sam-Shajing Sun, Department of Chemistry., Norfolk State University., Norfolk VA. 23504. A series of stable, processable, and end functional izable sulfone-derivatized phenylenevinylene based conjugated polymers (SFPVs) containing different donor type co-monomers have been synthesized and characterized. The polymer main chains consist of a sulfone-phenylene electron accepting unit coupled with an electron donating unit derived from one of the dialdehyde co-monomers based on benzene, thiophene, and pyrrole. The solution optical energy gaps and the electrical energy gap (thin fihTis) of these polymers are m the range of 1.94 - 2.45 eV and 2.04 - 2.51 eV respectively. The lowest energy gap was obtained from tlie polymer containing pyrrole unit due to the smallest resonance energy . The vinylene bounds on the polymer main chain are still chemically stable to survive strong basic conditions as compared to the S,S-dioxo-thiophene based PT V polymers developed earlier. These polymers also have very good thermal stability (onset decomposition temp, in N 2 gases, >270 "C). The lower energy gap P(Pyrrole-SFPV) exhibited ten times better photoelectric power conversion efficiency than the higher energy gap P(TV-SFPV). The diphosphonate ends functionalized and frontier energy level engineered of these conjugated polymers are very attractive in development of supramolecular block copolymers for the next generation of optoelectronic devices particularly in solar energy conversion applications. PROCEEDINGS 90“^ ANNUAL MEETING 51 BLUING OF HYDRANGEA MACROPHYLLA SEPALS BY INTRODUCING ALUMINUM IONS THROUGH ROOTS, CUT STEMS, AND SEPAL SURFACES. Henw D. Schreiber . Connne M. Lariviere, Andrew H. JoneSj Kelly M. Mayhew & Judith B. Cain, Department of Chemistry, Virginia Military Institute, Lexington, VA 24450. Sepals of many Hydrangea macrophylla are red when grown in basic to neutral soils, blue in acidic soils, and shades of purple in soils of mtermediate pH. Delphinidm- 3-glucoside that provides the red color to the sepals is transformed to a blue complex in the presence of molar Al( IIl ). Al( in) is only mobile in acidic soils so the roots can only assimilate aluminum as a citrate complex into the plants under acidic soil conditions. The threshold Al(III) content for bluing is about 40-80 pg/g fresh sepal. If the Al(III)-citrate complex is introduced into cut stems of red hydrangea inflorescences, several orders of magnitude more Al(Itl) must be distributed to the sepals before bluing occurs In addition, the bluing is not homogeneous throughout the sepals, but instead results in unique patterns in which the blue color advances from the center and outer edges. Evidently, the diffusion of Al(III) to the reaction centers, or pigment location, in the cell vacuoles is slow. An aqueous spray of a pH-adjusted Al(UI )-citrate solution was also directly applied to the sepals over a period of tmie. The rapidity of the bluing was related to the pigment concentration of the sepals; the cultivars with the lighter sepals and less pigment blued faster as less Al(III) was required for a molar excess. The threshold Al(III) contents were about the same as when obtained through the roots. HETEROGENEOUS OPENING OF EPOXIDES AND EPISULFIDES WITH AMINO ACIDS - AN APPROACH TO THE SYNTHESIS OF THIOES. Marc-Antoine Tremblay . Eric P. Ginsburg . Chelsea L. Brown, Ellen R. Simmons, Dylan J. Jamieson & Jeffrey M. Carney, Department of Molecular Biology and Chemistry, Cliristopher Newport University, Newport News, VA 23606. Cystinuria is a metabolic disorder that results in the accumulation of insoluble and reoccurring cystine stones in the kidneys. Only a few methods for the treatment of cystinuria exist and surgery to remove the stones is frequently required. Further research is necessary to determine how to best prevent and treat this painful disorder. One known treatment involves the use of thiols to break up cystine and increase solubility of the stones through disulfide exchange. Our vision is to develop a small library of thiol compounds via the nucleophilic opening of episulfides with amino acid derivatives. Epoxide ring-opening with amino acids represents a simpler model system, but it has also not been extensively studied under heterogeneous conditions. We report our progress in the development of both epoxide- and episulfide-ring opening using amino acids and a solid catalyst. MEASURING STUDENT COMPREHENSION OF LEARNING OBJECTIVES IN ORGANIC CHEMISTRY COMPUTATIONS EXPERIMENTS, M.K. Waddell. C. Bump, E. Ndip, and G. Nwokogu, Dept. Of Chemistry, Hampton University, Hampton, VA 23668. The incorporation of computation macromodels into several organic chemistry laboratory' experiments has been an ongoing endeavor. As a result, the measurement of student comprehension of these computational experiments has been assessed Students were surveyed on their perceptions of the learning objectives of an organic chemistry computation experiment. Pre and post surveys were administered through the BlackboardTM course webpage. Results were compared to identify trends and key areas of learning deficiencies. 52 VIRGINIA JOURNAL OF SCIENCE Computer Science ALERT: AN ARCHITECTURE FOR THE EMERGENCY RETASKING OF WIRELESS SENSOR NETWORKS. Sved R. Rizvi . Stephan Olariu, & Michele C. Weigle, Dept, of Computer Science, Old Dominion University, Norfolk, VA 23529. When an emergency or disaster strikes, first responders work as part of a complex emergency management network that calls upon many functions, resources, and capabilities. The objective of our research is to design a real-time information system to improve emergency-response functions by bringing together information to respond to a terrorist attack, natural disaster or other small or large-scale emergency. We call this system ALiF/^r; An Architecture for the Emergency Retasking of Wireless Sensor Networks. The novel contribution of this research to the emergency response strategies is the seamless integration of various wireless sensor networks by retasking them with explicit missions involving a dynamically changing situation. Preliminary results have shown that retasking sensor networks for emergency response is a promising new paradigm that can not only promote a wider adoption of sensor network systems in support of guarding our national infrastructure and public safety, but can also provide invaluable help with disaster management and search-and-rescue operations. DENSE UNSTRUCTURED AND STRUCTURED MATRIX COMPUTATIONS USING MPI. Stephen V. Providence, Dept, of Computer Science, Hampton University, Hampton, Virginia 23668. Computations with dense unstructured general matrices requires 0(} f) operations and 0(m) words of storage for n x n input matrices. Such matrices are encountered in applications to solving integral equations. The best algorithms involving computations with dense structured matrices require 0(n logfi) operations and 0(n) words of storage with small overhead constants. MPI or the message passing interface binds to the C programming language and is used to implement parallel algorithms. The time and space complexity estimates above are for sequential algorithms involving matrix computations. We have interest in the complexity estimates for parallel implementation of the sequential versions. For p processors where p<