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Friday paper presentations.

Section I: Biological Sciences

IC--318

Mark S. Davis and Terry D. Schwaner, Presiding

1:00 CANINE DISTEMPER VIRUS IN SOUTHWEST GEORGIA RACCOONS**, Krista A. Cox* and J. Mitchell Lockhart, Biology Department, Valdosta State University, Valdosta, GA, 31698. A member of the family Paramyxoviridae, canine distemper virus (CDV) causes canine distemper, a significant viral disease in raccoons and fur animals, producing morbidity and mortality in unvaccinated populations worldwide. Although dogs are the most commonly affected species, CDV is also seen in raccoons, foxes, ferrets, and minks. Comparatively, canine distemper is now rare in many industrialized countries due to vaccination. Transmission of the virus occurs via an aerosol-droplet route, direct contact, or possibly contact with contaminated objects. Approximately 365 raccoons from 2003 and 2004 were obtained from three southwest Georgia plantations as part of an ongoing USDA--Wildlife Services bobwhite-quail predator project. Of the 365 samples, 116 (31.8%) tested positive for CDV by indirect immunoflourescent assay utilizing commerical antigen coated slides. Comparisons of seasonal, host sex, and host age data will be evaluated. These data suggest considerable levels of canine distemper virus are present in southwest Georgia.

1:15 TRYPANOSOMA CRUZI IN SOUTHWEST GEORGIA OPOSSUMS**, Jessica L. Gillis* and J. Mitchell Lockhart, Biology Department, Valdosta State University, Valdosta, GA, 31698. Trypanosoma cruzi is a protozoan parasite causing a disease that affects many in Central and South America, but only few in the United States. The disease is transmitted by triatomine insects of the Reduviidae family. T. cruzi is predicted to occupy numerous mammalian hosts such as raccoons, coyotes, opossums, deer and dogs. Over 1,000 opossums were acquired from three Southwest Georgia plantations as a result of an ongoing USDA--Wildlife Services bobwhite-quail predator project. DNA isolations were performed on frozen opossum heart tissue and samples were examined for the presence of T. cruzi via polymerase chain reaction. Approximately 20% have tested positive for T. cruzi as of the submission date. Seasonal, host sex, and host age data will also be analyzed. These results suggest that there are significant levels of this parasite in southwest Georgia opossum populations.

1:30 TRYPANOSOMA CRUZI IN SOUTHWEST GEORGIA RACCOONS**, Berrien Waters* and J. Mitchell Lockhart, Biology Department, Valdosta State University, Valdosta, Georgia, 31698. Trypanosoma cruzi, a parasite known to cause Chagas' disease, has been thought to occupy several mammalian hosts including canines, opossums, and raccoons. Although most cases of Chagas' disease are found in Central and South America, the theory that T. cruzi utilizes hosts that live in the United States prompted the urge to determine the prevalence of the parasite in these animals. More than 200 raccoons were obtained from three isolated regions in south Georgia and north Florida as part of a USDA-Wildlife Services bobwhite quail predator removal study. DNA from frozen raccoon heart samples was tested for the presence of T. cruzi using polymerase chain reaction. For 2004, 42 of 210 samples (20.0%) have tested positive. These data will be compared with data collected in 2003 and will be analyzed using various natural history variables. Collectively, data from these 2 years suggest that there are considerable levels of T. cruzi in wildlife populations in these locations.

1:45 DETECTION OF THE CAUSATIVE AGENTS OF LYME DISEASE, EHRLICHIOSIS, AND STARI IN INDIVIDUAL SOUTHERN BLACK-LEGGED TICKS COLLECTED FROM WHITE-TAILED DEER OF THE PIEDMONT NATIONAL WILDLIFE REFUGE**, Joshua Ellis*, Melissa Harrison, Jackie Delash, Brian Sparks, Green Berry Starnes, IV and Alan F. Smith. Department of Biology, Mercer University, Macon, GA 31207. Over 1000 adult and nymphal ticks were collected from the carcasses of freshly harvested, white-tailed deer (Odocoileus virginianus) at the check station during two prescribed hunts (Oct. 21-23 and Nov. 4-6, 2004) in the Piedmont National Wildlife Refuge (Jones Co. and Jasper Co., GA). Southern black-legged ticks (Ixodes scapularis) comprised the overwhelming majority of the tick species, although lone star ticks (Amblyomma americanum) were well represented (~10%). Maintained individually at -20[degrees]C, total genomic DNA was extracted from single specimens and aliquots provided templates for the PCR-generation of agarose-gel-electrophoretic identifiable amplicons. Primers were designed from specific gene sequences as follows: a 378-bp Borrelia spp. FLA-1 gene fragment; a 459-bp Borrelia burgdorferi (Lyme disease) rOmpA gene fragment; a 247-bp Ehrlichia spp. 16s rRNA gene fragment; and a 900-bp Ixodes spp. nuclear ribosomal gene cluster fragment (ITS2). The rOmpA and FLA-1 amplicons allowed us to distinguish between the two ixodid-borne borreliae since OmpA is absent in B. lonestari. The presence of the Ixodes-specific amplicon served as an added control and confirmed the quality of the genomic extraction. The identity of the PCR products was confirmed by sequencing of the agarose gel-purified amplicons. Faculty Research and Development Grants from the College of Liberal Arts, Mercer University provided funding for this project.

2:00 THE INCIDENCE OF THE CAUSATIVE AGENTS OF LYME DISEASE, STARI, AND EHRLICHIOSIS IN MALE LONE STAR TICKS COLLECTED FROM FIVE MIDDLE GEORGIA COUNTIES**, Melissa Harrison*, Jackie Delash, Green Berry Starnes, IV, Brian Sparks, and Alan F. Smith, Department of Biology, Mercer University, Macon, GA 31207. During the spring through fall months over a two-year (2003-2004) period, male lone star ticks (Amblyomma americanum) were collected from five middle Georgia counties (Bibb, Jones, Houston, Monroe, and Crawford) by sweeping vegetation with cotton batting or from the carcasses of recently harvested white-tailed deer (Odocoileus virginianus) during prescribed hunts. Ticks were maintained individually at -20[degrees]C. Total genomic DNA was extracted from single specimens and aliquots provided templates for the PCR-generation of agarose-gel-electrophoretic identifiable amplicons. Primers were designed from specific gene sequences as follows: a 378-bp Borrelia spp. FLA-1 gene fragment; a 459-bp Borrelia burgdorferi (Lyme disease) rOmpA gene fragment; a 247-bp Ehrlichia spp. 16s rRNA gene fragment; and a 158-bp A. americanum ubiquitin gene fragment. The two sets of Borrelia primers allowed us to distinguish between the B. burgdorferi and B. lonestari spirochaetes since the latter lacks the rOmpA gene. Moreover, inclusion of the lone star tick-specific PCR step served as an additional control accounting for the quality of the genomic extraction: Borrelia- and/or Ehrlichia-free samples could then be readily distinguished from poorly-extracted or absent templates. The identity of the PCR products was confirmed by sequencing of the agarose gel-purified amplicons. Faculty Research and Development Grants from the College of Liberal Arts, Mercer University provided funding for this project.

2:15 PRELIMINARY STUDY OF TREE DISTRIBUTION PATTERNS AND DIVERSITY IN A TROPICAL DRY DECIDUOUS FOREST OF YUCATAN, MEXICO, A. Rachel Prakash (*1), Jeffrey Pittman (1), and Paula C. Jackson (1), (1) Kennesaw State University, Kennesaw, GA 30144. The dry deciduous forest of the Yucatan has been studied very little in comparison with its rainforest counterparts. The main factor influencing the forest is its seasonal rainfall and, potentially, subterranean water sources called cenotes. In this study we investigated how the following ecological parameters differed with distance to a cenote: 1) spatial distribution patterns (even, clumped or random) of six tree species with differing patterns of leaf production and loss (deciduous species: Bursera simaruba and Acacia gaumeri; briefly deciduous species: Phyllostylon brasiliense, Piscidia piscipuda, and Lysiloma latisiliquum; and the evergreen species: Gymnopodium floribundum); 2) [alpha]-diversity; and 3) whether there was a difference in rank abundance of species among sites. Two study sites were selected, one near, the other far (more than 800 m) from a cenote. At each site four 10 m X 10 m quadrats were randomly established, and coefficients of variation (CV = variance/mean) were used to determine spatial distribution patterns of species. Diversity was estimated with the Shannon index, and all species were ranked at each site based on abundance. Sites differed in diversity and in the rank order of abundance of each species. For all species studied, distribution patterns were not significantly different from random probably due to the small sample size.

2:30 POPULATION GENETICS OF GOPHER TORTOISES AT MOODY AIR FORCE BASE, GEORGIA**, David I. Mederos*, John F. Elder, Gregory Lee, and J. Mitchell Lockhart, Biology Department, Valdosta State University, Valdosta GA, 31698. Gopher tortoises (Gopherus polyphemus) are a threatened species in Georgia and a basic understanding of natural history and population genetic parameters is vital for successful management of the species. Knowledge of population genetics can provide important information concerning normal movement and artificial translocation of animals and perhaps diseases they may carry. DNA was isolated from the blood of 15 gopher tortoises from different colonies found on Moody Air Force Base, Georgia. Using microsatellite analysis from nine different VNTR loci we were able to establish the gene flow between colonies, genetic distance, and map out phylogenetic trees between different sub-populations. Data from an additional 80 animals will be generated and included in the final analysis.

2:45 ANALYSIS OF BODY SHAPE VARIATION OF RELATED TAXA OF HYBOPSIS (CYPRINIDAE) USING DISTORTION COORIDINATES**, P. Faith Owens*, Christopher E. Skelton, and William P. Wall, Georgia College & State University, Milledgeville, GA 31061. The minnow genus Hybopsis is represented by three species in Georgia (Hybopsis amblops, H. lineapunctata, and H. rubrifrons) and one or two undescribed forms. Recent analyses suggest that both potential undescribed forms are closely related to Hybopsis winchelli from Alabama and Mississippi. We analyzed the shape of the presumed undescribed forms and compared those with nominal H. winchelli as well as a primitive member of the group (Hybopsis amblops). We first generated digital photographs for each specimen studied then measured standard length on each fish which was then used as the standard for all other measurements in the computer analysis. Intra and inter-specific variation was analyzed using a variety of statistical methods (cluster analysis, principal components, discriminant analysis). Morphological variation was also determined visually using distortion coordinate analysis. The systematic and biogeographic implications of our findings will be discussed.

3:00 Break

3:15 THE USE OF ARTIFICIAL SUBSTRATE TO STUDY THE COLONIZATION PATTERNS OF MACROINVERTEBRATES IN A MIDDLE GEORGIA STREAM**, Chris Pace*, Joshua Ellis, Brian Sparks, Katie Smith, and Alan F. Smith, Department of Biology, Mercer University, Macon, GA 31207. Typical Middle Georgia streams are subject to high levels of silt deposition. In response, decreased substrate availability limits biological diversity. Previous colonization studies have utilized transient, biodegradable substrates such as wood and leaf packs, the use of which introduces two or more confounding variables (e.g., nutrients, mutable surfaces). In our experiment, we increased only the substrate availability through the introduction of non-nutritive, non-degradable, synthetic "leaf packs" (syn., pods). Six PVC-anchored stations, each with 12 sets of pods, were placed within a segment of a second-order stream, Hurricane Creek (Brender Demonstration Forest, Jones Co.) during the summer of 2003. Pods consisted of polypropylene and nylon leaf-sized fragments constrained by monofilament netting. Over the course of six months, pods from each station were randomly collected from each station, preserved, and later examined for the presence of macroinvertebrates. Physical parameters (e.g., pH, discharge, temperature, DO) were concurrently recorded at each station during pod harvesting. Identifications to the level of genus, where feasible, or morphospecies, provided pertinent data for the calculation of diversity indices for correlations with the physical parameters as well as elucidating changes in community structure over time. Faculty Research and Development Grants from the College of Liberal Arts, Mercer University, provided funding for this project.

3:30 EFFECTS OF NANO-SIZED PARTICLES OF COPPER OXIDE (CuO) ON SELENASTRUM CAPRICORNUTUM (CHLOROPHYTA), A. E. Sanford*, J. A. Nienow, T. J. Manning, Valdosta State University, Valdosta, GA 31698. Concerns have been raised recently about the potential hazardous effects of nanomaterials in the environment. To test the validity of these concerns, we investigated the effects of nano-sized particles of copper oxide (CuO) on the growth of the green alga Selenastrum capricornutum. Cultures were grown in liquid BBM solution supplemented with 2, 4, 8, or 40 mg of nano-sized or regular-sized particles of CuO per 100 mL of culture medium. The size of the population was monitored by periodic direct counts over a period of 14 d. The growth rate of S. capricornutum was significantly lower in cultures supplemented with 8 mg/100mL of nano-sized particles of CuO. The effect of nano-sized CuO on growth was less than the effect of adding CuS[O.sub.4] solutions. The cause of the decreased growth is not clear. Excess copper is thought to affect photosynthetic electron transport. We tested this hypothesis using pulse-amplitude-modulated (PAM) fluorometry on filtered aliquots of the cultures, but were unable to detect a significant difference in the photosynthetic yield.

3.45 FRESHWATER MUSSELS (UNIONIDAE) OF THE LITTLE OCMULGEE RIVER SYSTEM, GEORGIA**, Brooke N. Hawk (*1), Christopher E. Skelton (1), and C. Nathan Webb (2), (1) Georgia College & State University, Milledgeville, Georgia 31061 and (2) Medical College of Georgia, Augusta, Georgia 30904. The Little Ocmulgee River is a large tributary to the lower Ocmulgee River. Twenty-one sites in the Little Ocmulgee River system were surveyed for freshwater mussels between June and October, 2004. Surveys were conducted visually and by hand-grubbing in appropriate habitats. Surveys were timed and conducted for at least one total hour of search time at each site (person-hour). All live individuals and dead shells were examined at the survey site and all identifiable specimens were released. Difficult to identify forms were retained for later identification in the laboratory. Retained specimens were euthanized by freezing or by relaxing in a solution of tricaine methane sulfonate (MS-222). Relaxed specimens were preserved in 10% formalin and after rinsing with water, placed in 70% ethanol for permanent storage. Headwater portions of the system were dominated by species of the genus Elliptio and Uniomerus carolinianus. Lower portions of system harbored "big river" species typical of the Ocmulgee and Altamaha rivers such as Elliptio dariensis, E. hopetonensis, E. shepardiana, and Lampsilis dolabraeformis.

4:00 A SURVEY OF THE BATS OF BALDWIN COUNTY, CENTRAL GEORGIA**, Michael Bender* and Dennis Parmley, Georgia College & State University, Milledgeville, GA 31061. On the basis of published records, 16 species of bats occur in Georgia. Of these, only one, Tadarida brasiliensis, is documented from Baldwin County of central Georgia. Records from surrounding counties clearly suggest the probability of at least eight additional species occurring in the county. Due to a lack of documentation of the bat species inhabiting this area, we initiated a survey to compile a species list for Baldwin County. Since June 2004 we have used traditional capture/collection techniques and specimen handling procedures to survey bat populations living in this area. Thus far we have documented six species of bats to include Pipistrellus subflavus, Nycticeius humeralis, Lasiurus borealis, Lasiurus seminolus, Eptesicus fuscus, and Tadarida brasiliensis.

4:15 DISTRIBUTION OF DRAGONFLIES (ANISOPTERA) IN BALDWIN COUNTY, GEORGIA, Stephen R. Parrish*, Georgia College & State University, Milledgeville, Georgia 31061. The distribution of dragonflies (Anisoptera) in Baldwin County, Georgia was studied from March to November 2004. Dragonflies were collected and viewed at 12 different sites. When possible, new species were netted, immersed in acetone for a day, dried, and placed in labeled plastic envelopes. Before immersion they were chilled and photographed in posed positions. Dragonfly species were also identified by observation with binoculars. A total of 41 species of Anisoptera were found. Some of the less common species found include Gomphaeschna furcillata, Cordulegaster bilineata, Celithemis bertha, and Anax longipes. Species found earlier than previously recorded in Georgia are Epitheca (Tetragoneuria) costalis, Celithemis elisa, Cordulegaster bilineata, and Libellula cyanea. Late records were established for Gomphus (Gomphurus) dilatatus, Libellula auripennis, Libellula luctuosa, Boyeria vinosa, Libellula incesta, and Celithemis elisa.

4:30 PRELIMINARY ASSESSMENT OF THE FRESHWATER MUSSEL FAUNA (UNIONIDAE) OF THE BROAD RIVER SYSTEM, GEORGIA**, Stephanie S. Westmoreland* and Christopher E. Skelton, Georgia College & State University, Milledgeville, Georgia 31061. Fourteen sites were surveyed for freshwater mussels in the Broad River system of Georgia between 4 August and 26 September, 2004. Surveys were conducted visually and by hand-grubbing in appropriate habitats. Surveys were timed and conducted for at least one total hour of search time at each site (person-hour). All live individuals and dead shells were examined at the survey site. Because the taxonomy of Atlantic Slope mussels is poorly understood, we kept examples of each discernible form for later identification in the laboratory. Retained specimens were later relaxed in a solution of tricaine methane sulfonate (MS-222), preserved in 10% formalin and after rinsing with water, placed in 70% ethanol for permanent storage. Native mussels were found at ten of 14 sites and the exotic Asian clam (Corbicula fluminea) was found at twelve of fourteen sites. The mussel fauna was dominated by common members of the genus Elliptio and Uniomerus carolinianus.

4:45 REVERSE GENETICS MADE AVAILABLE TO UNDERGRADUATES: TILLING THE DET2 GENE**, Emily Deanna Salman* and Ryan Becker, Mercer University, Macon, Georgia 31207. Reverse genetics is a newly emerging field that has developed in response to the influx of genomic data generated from high-throughput technology. A new technique, TILLING (Targeted Induced Local Lesions In Genomes), is a reverse genetic approach that correlates genetic structure to subsequent gene function. In TILLING, an allelic series is generated and the phenotypic responses for the different mutants are examined. An allelic series for the det2 gene of the model organism Arabidopsis thaliana is currently being developed. Det2 is one of the several light response genes in the photo-morphogenic pathway of A. thaliana. The phenotypic evaluation of this allelic series will measure hypocotyl response under different light conditions. Part of my research involves modifying the CELI genotyping assay in order to examine the TILLED mutants in an undergraduate setting. TILLING is a useful tool for an undergraduate laboratory as a method for understanding reverse genetics as well as high-throughput technology.

Section II: Chemistry

IC--417

Ken Martin, Presiding

2:30 PHOTOCHEMICAL PROPERTIES OF NON-BENZENOID TETRASUBSTITUTED PORPHYRINS, Mark Wehunt (*1), Amber Everett (1), Adegboye Adeyemo (2), and James LoBue (1), (1) Georgia Southern University, Statesboro, GA 30460 and (2) Savannah State University, Savannah, GA 31404. Photodynamic Therapy (PDT) utilizes a combination of light with a photosensitizer molecule as a method for the treatment of tumors. We are interested in studying the photochemical properties of a group of tetra-substituted porphyrin molecules for their potential as photosensitizer drugs. The fluorescence quantum yields and luminescence lifetimes of two tetraquinolinyl porphyrin derivatives are compared. The luminescence lifetimes of tetra-3-quinolino porphyrin and tetra-4-quinolino porphyrin were 13 ns and 9 ns, respectively. The fluorescence quantum yields of tetra-3-quinolino porphyrin and tetra-4-quinolino porphyrin were calculated to be 0.14 and 0.27, using tetra phenyl poryphyrin (TPP) as a quantum yield reference.

2:45 PHOTOCHEMICAL PROPERTIES OF SUBSTITUTED TETRAPHENYL PORPHYRINS, Amber Everett (*1), Mark Wehunt (1), Adegboye Adeyemo (2), and James LoBue (1), (1) Georgia Southern University, Statesboro, GA 30460 and (2) Savannah State University, Savannah, GA 31404. Several porphyrins were studied to see if they could be used in photodynamic therapy. In photodynamic therapy an oral or topical photosensitizing agent is used in conjunction with exposure to light. Porphyrin photosensitizers are absorbed by tumor tissue preferentially and once the tumor with porphyrin is irradiated with light, the tumor is destroyed (by the singlet oxygen that forms). In this study, 2- and 4-Amino tetraphenyl porphyrins (TPP) were analyzed by measuring their absorbance, fluorescence, and luminescence lifetimes. The luminescence quantum yields for these two molecules were determined by using tetraphenyl porphyrin as a reference. The quantum yield for 2-Amino TPP was determined to be 0.05 and the 4-Amino TPP was 0.31. Lifetime for 4-Amino TPP was observed at 5.42 ns. The lifetime for 2-Amino TPP could not be effectively determined but appears to be significantly shorter than its 4-Amino partner.

3:00 Break

3:30 PHYTOCHEMICAL INVESTIGATION OF SARGASSUM FLUITANS, Delicia L. Emanuel*, J. Richard Carter, James A. Nienow, and James T. Baxter, Valdosta State University, Valdosta, GA 31698. The chloroform extract of Sargassum fluitans, marine brown algae, obtained from the Gulf of Mexico in June 2003, was analyzed using GC-MS. At least fourteen compounds were identified including 1-hexadecene, 3-hexadecene, heptadecanoic acid, and heptadecanoic acid, ethyl ester.

3:45 REDUCTION OF KETONES IN SOLUTION AND ON DRY SILICA, Flynt Goodson*, Giso Abadi, and John T. Barbas, Valdosta State University, Valdosta, GA 31698. Cyclic and bicyclic ketones were adsorbed on activated silica by stirring in organic solvents. The solvents were removed under vacuum giving a free flowing powder. Similarly sodium borohydride was adsorbed on activated silica and the solvent removed under vacuum. Mixing the two powders at room temperature resulted in a facile reduction of the ketones with half lives of less than two hours. The two isomeric alcohols obtained from each ketone were analyzed using NMR techniques and their ratios were compared to the same reactions done in solution and to predictions made using molecular modeling. In some cases the ratios in the solid state were identical to those obtained in solution whereas in other cases the ratios were somewhat different, favoring hydride attack from the less hindered side when adsorbed on silica. For example, the reduction of 2-methylcyclohexanone in methanol and on silica gave identical results of 60% trans-2-methylcyclohexanol and 40% cis-2-methylcyclohexanol. However, the reduction of 4-tert-butylcyclohexanone gave 89% trans-4-tert-butylcyclohexanol and 11% of the cis isomer in methanol but on silica it gave 82% of the trans isomer and 18% of the cis isomer. Work is continuing with polymer-supported reducing agents.

4:00 SIMPLE AND SPEEDY SYNTHESIS OF POLY(p-PHENYLENE ETHYNYLENE)S USING ACETYLENE GAS, Kevin P. Gwaltney (1), Kimberly A. Kellett (1), Daniel R. Durham (1), Igal Maasen (1), James M. Gilbert (1), and Uwe H. F. Bunz (2), (1) Kennesaw State University, Kennesaw, GA 30144 and (2) Georgia Institute of Technology, Atlanta, GA 30332. We have further investigated the direct coupling of acetylene and arenes to synthesize poly(p-phenylene ethynylene)s (PPEs). A variety of polymers and copolymers were produced. The monomers, acetylene gas and diiodoaryl compounds, are polymerized by a Pd/Cu catalyst. This method conserves two or more steps, thus is more efficient than the conventional metathesis or coupling methods. In addition, the method allows straightforward synthesis of random copolymers. Dialkyl-PPEs, dialkoxy-PPEs and random copolymers have been synthesized. Copolymers of diiodofluorene with dialkyl or dialkoxy arenes were also synthesized. Catalyst load, reaction temperature and reaction time were varied. Number average molecular weights, measured by gel permeation chromatography with polystyrene standardization, ranged from 3,000 to 84,000. Degree of polymerization was limited by solubility of the monomers and oligomers. Diiodofluorene provided the most difficulty due to insolubility. Characterization included fluorescence, UV-Vis, (1) H NMR, (13) C NMR and IR. Microstructuring was performed using the breath figure method creating a hexagonal array of 0.2-10 mm structures.

Section III: Earth and Atmospheric Science

IC--421

Mark Groszos, Presiding

2:00 A PRELIMINARY ANALYSIS OF AN EOCENE FOSSIL FAUNA FROM THE IMERYS SHEPPARD MINE, WASHINGTON COUNTY, GEORGIA**, Joseph W. Sheffield (*1), Alfred J. Mead (1) and Bob J. Pruett (2), (1) Georgia College & State University, Milledgeville, GA 31061 and (2) Imerys Clays, Sandersville, GA 31082. Beginning in the fall of 2004, researchers from Georgia College & State University began a systematic analysis of fossil material from the Imerys Sheppard Kaolin Mine in Washington County, Georgia. The fossiliferous horizon lies immediately above the Tertiary kaolin deposit and is exposed on the pit's highwall. Field observations suggest that the fossiliferous horizon is dominated by in situ oyster bioherms. Sections of the deposit have been excavated and examined for faunal composition. The invertebrate fauna is dominated by the oyster Crassostrea cf. gigantissima. Additional invertebrates include fragmented Chlamys, endocasts of Turritella, larger gastropods and wedge clams, and fragmented bryozoans and decapods. The chondricthyean fauna includes several shark species and at least one mylobatid ray species. Osteichthyeans are represented by several vertebrae and spines. The stratigraphic position and faunal composition suggest that this fossiliferous horizon represents an eastern portion of the Riggins Mill Member of the Clinchfield Formation.

2:15 A PRELIMINARY DESCRIPTION OF THE PLEISTOCENE HERPETOFAUNA FROM CLARK QUARRY, BRUNSWICK, GEORGIA**, Joshua L. Clark*, Kelly A. Clark*, Alfred J. Mead, Dennis Parmley and Robert A. Bahn, Georgia College & State University, Milledgeville, GA 31061. Excavations at Clark Quarry near Brunswick, Georgia, continue to produce Pleistocene-aged vertebrate fossils. The vertebrate macrofossils are dominated by the large mammals Mammuthus columbi and Bison latifrons. The herpetofauna are dominated by fragments of turtle carapace and plastron elements and osteoderms. This material represents at least one species of large tortoise and two species of emydid turtles. Osteoderms and numerous teeth indicate the presence of Alligator mississippiensis. Natricine snake vertebrae identified thus far include Nerodia sp. and Thamnophis sp. Three lacertilian vertebrae have been recovered. Anurans are indicated by the presence of ranid vertebrae, ilia, and a maxilla fragment. This herpetofauna suggests a riverine habitat with winter temperatures slightly more moderate than presently exist in the area.

2:30 BISON LATIFRONS (ARTIODACTYLA) FROM THE PLEISTOCENE OF BRUNSWICK, GEORGIA, Robert A. Bahn* and Alfred J. Mead, Georgia College & State University, Milledgeville, GA 31061. Fossil remains of the giant Pleistocene bison (Bison latifrons) have been known from Georgia since the mid-1800's. The majority of this material was discovered in spoil piles following dredging of coastal rivers. Some in situ bison material was also recovered during the construction of the Brunswick Canal between 1838-39. Previous authors tentatively identified these fossils as belonging to Bison latifrons or Bison sp. based on post-cranial comparative measurements to Bison bison. However, due to the similarity of post-cranial material between these species, no definitive identification could be made. A nearly complete skull of Bison was recovered during excavations at Clark Quarry near Brunswick, GA during the summer of 2004. Measurements of horn-cores, the definitive species character, positively identifies the skull as Bison latifrons. In addition to the skull, Clark Quarry has produced a minimum of two individuals of Bison, based on two right dentaries. Additional material includes: numerous cervical, thorasic, lumbar, and caudal vertebrae, numerous ribs, two scapulae, four humeri, two radio-ulnae, one femur, one tibia, and numerous podials.

2:45 OCHNA LIKE FRUIT FROM THE PALEOCENE OF NORTH DAKOTA, Mark A. Brewer (*1), Melanie L. DeVore (1) and Kathleen B. Pigg (2), (1) Georgia College & State University, Milledgeville, GA 31061 and (2) Arizona State University, Tempe, AZ 85287-4501. Compound fruits comprised of five-six single-seeded follicles were first described from the Almont site in Morton County, ND. Additional specimens have been collected from the Kate's Butte site in McKenzie County, ND. Both of these floras are equivalent in age based on the composition of plant megafossil assemblages and contain excellently preserved fruit and seed material. The follicles are teardrop shaped, 4-7 mm in length and 3-4 mm wide, with 0.2-0.4 mm thick walls. Follicles are radially attached by their constricted side to a thick receptacle. Individual follicles are found in the matrix suggesting that the fruit separated at maturity. The fossil fruit material is most similar to fruits of Ochna that are also concrescent and consist of 2-5 clustered single-seeded drupes or capsules. There is currently no complete taxonomic treatment of Ochnaceae and a phylogeny has not been constructed for the family. Ochnaceae is distributed in both the Old World and New Work tropics and subtropics. The presence of Ochnaceae in the Paleocene of North America suggests that the family had been a circumpolar element and was represented in more temperate floras in the past and today has survived and radiated in the tropics.

3:00 Break

3:15 MAPLE FRUITS FROM THE PALEOCENE OF NORTH DAKOTA, Alex Kittle (*1), Melanie DeVore (1), Bill Wall (1) and Kathleen Pigg (2), (1) Georgia College & State University, Milledgeville, GA 31061 and (2) Arizona State University, Tempe, AZ 85287-4501. Winged fruits are a conspicuous component of Cenozoic floras (e.g. Florissant and Green River). One of the most recognizable types of winged fruits is the samara. Two samara types are represented in the Almont and Beicegel Creek, ND floras from the Sentinel Butte Formation. The first samara type represents the genus Securidaca (Polygalaceae). The second samara clearly can be placed in the genus Acer (maple, Sapindaceae) and represents the oldest record of fruits belonging to the maples. The Acer-like samaras are 2.75-5.50 cm long and 1.5-2.5 cm wide. The fruits belong to the genus based on shape, wing venation and basal attachment scars. The fossil Acer-like samaras differ from most modern members of Acer based on the presence of a pronounced, elongated stipe. To date, no fossil foliage assignable to this genus has been documented from the Paleocene of North Dakota. However, Acer leaves have been described from the uppermost Paleocene of southeastern Alaska. Like the dogwoods (Cornaceae), the maples have a disjunct distribution between eastern North America and eastern Asia. Acer also has an eastern North America and eastern Mexican pattern of distribution. In the case of Acer, the genus first appeared in the Paleocene and underwent a major radiation in the Eocene. Means of dispersal are clearly significant when examining the radiation of a taxon and the utility of applying aerodynamics to assessing dispersal capability will be addressed.

3:30 ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY AS A TOOL TO EVALUATE MODERN AND FOSSIL MICROBIAL TAPHONOMY, Phillip M. Cole* and Julie K. Bartley, Department of Geosciences, State University of West Georgia, Carrollton, GA 30118. The Environmental Scanning Electron Microscope (ESEM) allows high-resolution imaging of uncoated, delicate, and hydrated samples. Using this tool, fresh microbial cultures can be imaged directly and their surface morphology compared to fossil microbes in chert or shale. We conducted a series of ESEM analyses of modern and fossil microbes, with the aim of identifying common taphonomic and taxonomic features. Because specimens are uncoated, observed fine-scale surface structures cannot be artifacts of elemental coating, and modern and fossil organic structures can be compared directly. Live cultures of Eremosphaera were assessed using the ESEM in environmental mode (hydrated). Uncollapsed cells exhibited the typical smooth-walled structure that characterizes this alga. However, collapsed cells displayed a fine-scale reticulate surface pattern. Some acritarchs possess a similar reticulate texture, which has been described as a taxonomic feature. Our results suggest that this surface pattern could be created by diagenetic processes such as compaction or desiccation. We are currently investigating other algal taxa to determine whether the observed reticulate pattern forms commonly during collapse, or whether its expression is limited to certain algal groups.

Section IV: Physics, Mathematics,

Computer Science and Technology

IC--321

A. Lazari, Presiding

2:00 SYSTEMATIC ERRORS IN THE EXPERIMENTAL MEASURMENT OF THE CHARGE TO MASS RATIO OF THE ELECTRON, Zade J. Coley, George E. Keller and James C. Espinosa, State University of West Georgia, Carrollton, GA 30118. An experiment employing inexpensive equipment has been used to determine e/m for the electron. The results of the experiment are found to be systematically higher than the standard value. The work presented here is the analysis of these systematic errors in terms of the equipment design. Corrections in the calculation of results were obtained that can be attributed to "cheap" design. The justifiable corrections give results that are randomly distributed, to within a few percent, about the standard value of e/m. The standard value for e/m equals 1.7588 X [10.sup.11] C/kg. The initial results were off 25% to 40% from the standard value as the radius of curvature of the electron path changes from 26cm to 13cm. After applying the corrections, the % error was 0.13% with random deviation. The details of the equipment, procedure, and the raw results will be presented, and the method of inferring the source of the systematic error and calculation of the corrections to be applied will be discussed.

2:15 ACOUSTIC FIRE CONTROL IN MICROGRAVITY**, Zade Coley, Matt Herron, Elizabeth Nelson, Dmitriy Plaks, and James Espinosa. State University of West Georgia, Carrollton, GA 30118. Our objective is to study the effects of acoustics on a flame in microgravity. Our research may provide a new approach to reducing and extinguishing a combustion reaction in space (where a conventional fire extinguisher is hazardous). We propose to test the following hypotheses: 1) as sound intensity increases, so does the magnitude of the effect on the flame, 2) there is an optimal frequency for maximizing the effects of sound waves on a flame, 3) homogenous flames (found only in microgravity) can be affected in a single area separate of others, 4) a sustained pulse of sound, rather than a single, brief pulse, can be used to extinguish a flame. Our setup includes an interior cage, inside of which is a candle; four speakers surround the cage, which are used to manipulate the flame. A video camera, infrared camera, light sensor, and microphone are placed in various locations throughout the setup to collect data. A master computer records all data and is later used for data analysis. The experiment will be performed aboard a NASA DC-9 Aircraft. We have written and submitted a proposal to NASA's Reduced Gravity Student Flight Opportunities Program (RGSFOP). Testing done in a 1 g environment indicates hypotheses 1 and 4 are correct.

2:30 A RETARDED CORRECTION TO NEWTON'S LAW OF GRAVITY, Gary Hunter, James Espinosa, and Julie Talbot, State University of West Georgia, Carrollton, GA 30118. Historically, the first experimental observation inconsistent with Newton's law of gravity was the precession of the perihelion of Mercury. The orbit of the innermost planet is shifted by a very small but measurable amount due to the intense gravitational force caused by its proximity to the Sun. One of the first theories to correctly account for this precession was Einstein's Theory of General Relativity. As an alternate approach we have modified Newton's law of gravity by assuming that gravity travels at the speed of light. From this assumption, we derived an equation that includes the relative velocity between two objects. An equation of motion for Mercury was solved numerically with Mathematica. The resulting orbit prediction was compared with the measured precession of the perihelion of Mercury. The theoretical prediction for the rate of precession is 43" per century which agrees well with the observed value of 43.11" [+ or -] .45" per century.

2:45 USING MATLAB TO SIMULATE THE DYNAMICS OF A THREE BODY SYSTEM**, Heidi L. Lesser, and J. E. Hasbun, State University of West Georgia, Carrollton, GA 30118. In a three-body system, Newton's second law of motion is written as,

[m.sub.i] [[[d.sup.2][[right arrow].r.sub.i]]/[d[t.sup.2]]] = [summation over (j)][[right arrow].F.sub.i,j], where [[right arrow].r.sub.i] is the ith body of mass [m.sub.i], and [[right arrow].F.sub.i,j] represents the gravitational force on the ith body due to the jth body. In this work we simulate the resulting second order differential equations for a three-body system. We perform simulations under two cases. The first case is that for which two of the more massive bodies, separated by a finite distance, are at rest while a third body orbits them. The simulation is capable of rendering orbits such as the popular figure eight, and the example for which the two massive bodies act as one. The second case is the more numerically involved example of two bodies orbiting the third, more massive body. In this simulation, the case that closely resembles the Sun-Earth-Moon system is one of several possible orbital characteristics. We conclude by presenting the results of the above mentioned orbits as well as others and, in particular, how the initial conditions affect the final orbital shapes. Additionally, we will discuss the details of the incorporation of the differential equations and their solutions as performed by the MATLAB script used here.

3:00 SIMPLIFIED WATER BALLOON LAUNCHER, L. Andrew Block and J.E. Hasbun, State University of West Georgia, Carrollton, GA 30118. In the talk we present a water-balloon launcher designed with a range of about 100 meters. The analysis for its design was made using standard classical mechanics formulas. The project began with a device built at a local high school to launch a water balloon projectile. This launcher happens to stand at about 10 feet high and about 4 feet wide. The disadvantages of the high school model are that its range is highly variable and it is difficult to aim, in addition to the awkwardness of its sheer size. We set out to develop a simplified version with the same or greater capabilities and better accuracy. The analysis began with a desired ideal range of 100 meters. From this range and a set barrel angle, the necessary muzzle velocity was calculated. The calculation further assumed an ideal spherical water balloon as well as windless environmental conditions. The muzzle velocity required defined the needed acceleration and thereby a certain barrel length. Since the apparatus desired was to employ springs rather than elastic bands, the spring constant was thus determined. Preliminary results demonstrate that the current simplified model is indeed capable of launching water balloons more precisely. Yet to achieve the objective range a better launching mechanism is needed as well as a more detailed model to explain the energy transfer process. In conclusion, there are several unknown parameters that our theoretical model does not include and more experimental testing is needed for a detailed understanding of the current launcher prototype.

3:15 THE EXPERIMENTAL VERIFICATION OF THE DE BROGLIE HYPOTHESIS**, Gary L. Hunter, George E. Keller, and James C. Espinosa, Physics Department, State University of West Georgia, Carrollton, GA 30118. A simple experiment, utilizing inexpensive equipment to diffract electrons with a graphitized carbon crystal, can predict the de Broglie wavelength of the electron, [lambda] = h/p, to within .6 to 1.5 percent. Experimental measurements of the de Broglie wavelength were made using the diffraction maxima for voltages 2500, 3500, 4000, 4400 volts. The experimental results were compared to the theoretical values, [lambda] = h/(2meV)[.sup.1/2], for these voltages. Experimental procedure, data, calculations, and results will be presented and discussed in detail.

3:30 A COMPARISON OF THE ELECTRIC BREAKDOWN PROCESSES IN WATER AND HEAVY WATER**, Dmitriy Plaks and James Espinosa, State University of West Georgia, Carrollton, GA 30118. Whenever a sufficiently high electric field is imposed on an insulator, dielectric breakdown occurs; lightning in a thunderstorm is a classic example. We are investigating how electric sparks form in heavy water ([D.sub.2]O) in order to test Espinosa's model of dielectric breakdown in regular water ([H.sub.2]0). According to accepted theory, there should be no difference between these two forms of water since they are electronically identical. However Espinosa's model predicts that there should be a big difference between them. We will measure both the electric field necessary and the time needed to create an electric spark in samples of heavy water and regular water that have identical electrical conductivity. The electrodes will have a point to plate geometry. The conductance of the solutions will be measured with an Omega conductivity meter. The voltage and the current in the water gaps will be measured as a function of time using Pearson transformers. The temporal data will be stored in a digital oscilloscope. If Espinosa's model is correct, we expect heavy water to breakdown at 16 kV/cm, which is half the electric field needed to breakdown regular water.

3:45 SIMULATION OF m ELECTRONS INTERACTING WITH n IMPURITIES IN AN EXTERNAL ELECTRIC FIELD IN NANO-DEVICES, Max F Perkins and J. E. Hasbun, State University of West Georgia, Carrollton, GA 30118. In this paper we simulate the motion of electrons interacting with impurities through the Coulomb force in addition to an external electric field oriented in the direction. The motion takes place in the x-y plane, and electron-electron interactions are ignored. The general equations of motion are therefore:

m [[d.sup.2]/[d[t.sup.2]]] [x.sub.j] = -[n.summation over (i)] [[K[q.sup.2]([x.sub.j]-ia)]/[(([x.sub.j]-ia)[.sup.2] + ([y.sub.j]-ib)[.sup.2]))[.sup.3/2]]] + [E.sub.x] (1), for thedirection, and

m [[d.sup.2]/[d[t.sup.2]]] [y.sub.j] = -[n.summation over (i)] [[K[q.sup.2]([y.sub.j]-ia)]/[(([x.sub.i]-ia)[.sup.2] + ([y.sub.j]-ib)[.sup.2]))[.sup.3/2]]] (2), for the y direction. Here and [x.sub.j] and [y.sub.j] represent the position of the [j.sup.ith] electron, with mass m, interacting with the [i.sup.ith] impurity. The impurity separation is determined according to multiples of crystal lattice constants a and b as seen in equations (1) and (2) above with K = 1/4[pi][[epsilon].sub.0]. In this simulation the charge of the electrons is q and the impurities are assumed to have equal and opposite charge. The simulation has been made possible through the use of the Open Source Physics (OSP) Java library. We will present examples of simulations performed with different parameters. We conclude that the simulations are very useful in demonstrating the multi-body interactions that goes on within nano electrical devices.

4:00 COMPUTERIZED UNDERDAMPED HARMONIC OSCILLATOR EXPERIMENT, Clayton W. Huff, and J. E. Hasbun, State University of West Georgia, Carrollton, GA 30118. In this experiment we have digitized the time dependent position of a suspended harmonic oscillator (HO) and analyzed the data using a MATLAB script that incorporates the theoretical formulas corresponding to an under-damped HO. The data was taken using a VERNIER sensor that measures force with respect to time. The sensor was controlled through the VERNIER software and has the capability to start and stop the data recording process. The experimental data is calibrated according to a linear relation that was found to exist between the force and the displacement versus time. A bare HO does not have the capability to damp out quickly, thus a special damper was fabricated, which permitted us to observe a damping effect in a relatively short time span. The data was read by the MATLAB script then plotted. A theoretical curve was superimposed by the script, which required adjustable parameters to be imputed a priori. This process was repeated several times until a reasonable low error was obtained between theory and experiment. The error was calculated based on the average of the sum of the squares of the differences between the calculated positions and the actual positions. The lowest error obtained in this manner guided us to determine the best fitting parameters. We conclude that this method is a great opportunity to experience the true nature of a harmonic oscillator in addition to the fact that it is a very efficient way to study its damping characteristics.

4:15 USING WELL KNOWN PROBABILITY DENSITY FUNCTIONS IN CALCULUS, Stacey Pittman, and Andreas Lazari, Mathematics and Computer Science Department, Valdosta State University, Valdosta, GA 31698. Learning and practicing integration techniques is something required of every calculus student. However, some methods of integration can be difficult and time consuming for students, especially the famous method know as integration by parts. While introduced to calculus students as a means of obtaining a simpler, solvable integral from a more complex integral, integration by parts often involves multiple applications of the method in order to get the problem into a form simple enough to solve. The lengthy and tedious process involved in integration by parts often generates algebra errors that are hard to correct, leaving students frustrated with the method. Students may even find themselves asking if there is a better way to calculate these problems. Luckily, there is a better way. Some integrals can be evaluated using probability density functions (p.d.f's) that tremendously simplify and shorten the work. Moreover, the chance of an algebra error is greatly reduced. Yet, p.d.f's are not taught in calculus. In this paper, I will introduce well-known probability density functions and explain how they can be used as an alternative way for evaluating some integrals in calculus. I will also present an argument as to why p.d.f's should be added to calculus programs.

Section V: Biomedical Sciences

IC--410

Pamela Moolenaar-Wirsiy, presiding

1:00 NEW METHODS FOR VACCINE DESIGN AND EVALUATION AGAINST CHLAMYDIA. Joseph U. Igietseme*, Francis Eko, Qing He, Godwin Ananaba, Teresa Brown, Claudiu Bandea, Godwin Ifere, Deborah Lyn and Carolyn M. Black, National Center for Infectious Diseases, CDC, Atlanta GA 30333 and Morehouse School of Medicine, Atlanta, GA 30310. Chlamydia trachomatis is the most common bacterial sexually transmitted disease in the United States and several industrialized countries. An effective vaccine will constitute the best approach to control the infection and the complications that include pelvic inflammatory disease and involuntary tubal factor infertility. The objective of these studies was to define the elements of protective immunity against genital chlamydial infection, design specific experimental vaccines, and evaluate their efficacies in a mouse model of the disease. T cell clones characterized as high IFN-[gamma]-secreting CD4 (A-1) and CD8 (B-1) cells transferred significant protection (P > 0.0001 and 0.002, respectively) against genital chlamydial infection, although the CD4 T cell clones conferred a greater level of immunity. Also, mice that cleared their infections had elevated levels of IgA and IgG2a in their cervico-vaginal secretions two weeks after cell transfer, suggesting an adequate T cell help for a humoral immune response. The ability of a clone to resolve an infection was dose-dependent, requiring high IFN-[gamma] secretion, and coincided with a timely recruitment and maintenance of a high frequency of T cells in the genital mucosa of infected animals. In conclusion, the immunologic basis for the apparent greater contribution of CD4 than CD8 Th1 cells to chlamydial immunity was associated with the enhanced helper function of CD4 Th1 cells for specific antibody response. Potentially protective vaccine constructs require the delivery of multiple chlamydial subunits, the induction of an early and elevated IL-12, and activation of a high frequency of Th1 cells.

1:30 ISOLATION, PURIFICATION & CHARACTERIZATION OF ANTISTENOTRO-PHOMONAS MALTOPHILIA IMMUNOGLOBULINS** Freeman Smalls (1) D.L. Scott (2) E. Archibold, Clark Atlanta University Atlanta, GA 30314 D2 Biotechnology, Atlanta, GA 30314 and Morehouse College, 30314. The resistance of Stenotrophomonas maltophilia to antimicrobial agents is rapidly becoming a major medical and public health problem. The frequent treatment of S. maltophilia borne infections with the same anti-microbial agent over a period of time inherently results in the pathogen developing resistance to the drug. A polyclonal antibody cocktail (D2-DLS01) were used to recover surfaces exposed immunogenic polypeptides (SEIP's) from the cell walls of S. maltophilia. Individual SEIP's were characterized and bioinformatics strategies employed to localize immunogenic amino acid sequences. The strategy described in this application for the recovery of immunogenic polypeptides provides invaluable information in reference to what epitope on the surface of a pathogenic microorganism is accessible by the immune system of the said host. Individual S. maltophilia surface exposed immunogenic. polypeptides were evaluated in growth inhibition studies and enzyme link absorbance assay (ELISA) to determine their applicability as targets for complement independent immunoglobulin neutralization The data suggest that serial dilution (100-fold increments) of D2-DLS01 antisera (10-[.sup.2] dilutions) showed significant binding of D2-DLS01 to S. maltophilia antigens as compared to controls. The data showed that D2-DLS01 inhibited the proliferation of S. maltophila and several gram negative bacteria suggesting that there are conserved sequences that are common among gram negative bacteria, however D2-DLS01 did not show any inhibition of proliferation on gram positive bacteria (S. aureus), suggesting that there are no common conserved sequence among gram negative and gram positive bacteria.

2:00 TRYPANOSOMA BRUCEI INFECTION MODULATES APOPTOTIC GENES AND GENE PRODUCTS IN THE MOUSE SPLEEN**, Eric B. Darrington (1,3), Dennis Spencer (1,2), Ikowa Irune (3), Jonathan K. Stiles (3), (1) Department of Biological Sciences, Clark Atlanta University Atlanta Georgia (2) Department of Biology, Morehouse College Atlanta Georgia, (3) Department of Microbiology, Biochemistry and Immunology, Morehouse School of Medicine Atlanta Georgia, 30310. Human African trypanosomiasis (HAT) is caused by infection with Trypanosoma brucei. T. brucei infection results in perivascular infiltration, meningoencephalitis, blood brain barrier dysfunction, and apoptosis. The molecular mechanisms mediating these complications are unclear. It has previously been reported that T. brucei induces apoptosis in cerebellum and brainstem cells at peak parasitemia; and earlier work suggests that T. brucei procyclin might play a role in the up-regulation of the apoptotic genes for Bax, Caspase-3, Caspase-8, and Caspase-9 in infected mouse brain. However, it is not known whether this phenomenon occurs in the other organs of infected hosts. Here, we hypothesized that T. brucei infection would affect the expression of specific apoptotic markers. It was observed, that in the animals infected with T. brucei, there was enhanced tissue damage coupled with expression of trypanosomal procyclin, Caspase-3, -8, -9 and Bax in spleen tissue. A thorough understanding of the interaction between parasite and host proteins in various host organs is required for full comprehension of the mechanisms that drive the complications associated with T. brucei infection. Trypanosomal procyclin's apparent role in the pathology of HAT suggests the possibility that it could be a potential drug target for protection against T. brucei infection.

2:30 THE EFFECT OF ESTROGEN ON CHLAMYDIA INFECTION AND CHEMOKINE EXPRESSION**, Erika L. Barr (1), Tesfaye Belay (1), Frances O Eko (2), Joseph Igietseme (*2), and Godwin Ananaba (1), (1) Clark Atlanta University, Morehouse School of Medicine, Atlanta GA 30310 and (2) CDC & Prevention, Atlanta, GA 30333. Diseases caused by Chlamydia trachomatis range from acute self-limiting infection to chronic inflammatory condition, which results in inflammatory disease, infertility, and ectopic pregnancy. Although, clearance of Chlamydia from the host has been shown to be associated with the recruitment of immune cells such as T-helper type 1 (Th1), it is also believed that the frequency and activity of these cells may be influenced by changes in the levels of the local immunoregulatory factors. The aim of this study was to examine the influence of estrogen on the level of chemokine production during Chlamydia infection. We hypothesized that estrogen increases susceptibility to Chlamydia infection by decreasing the level of Th1 chemokine expression. HeLa cells were treated with various concentrations of estrogen for 24 hours prior to infection with various concentrations of Chlamydia (MoPn) ([10.sup.6], [10.sup.7], [10.sup.8]). Following 32 h of infection, supernatant was collected and assayed for the presence of chemokines (RANTES, IP-10 and MCP-1). Inclusion bodies were stained and enumerated using florescent microscopy. Increased susceptibility to Chlamydia infection and decreased chemokine production was observed in the estrogen treated HeLa cells compared to the controls. These results indicate that estrogen does have some affect on Chlamydia infection and may play a possible role in altering chemokine expression. Supported by NIH grants RR03034, A141231.

3:00 MAXIMAL CEREBELLAR EXPRESSION OF CYTOKINES AND ADHESION MOLECULES IN FATAL PEDIATRIC CEREBRAL MALARIA** Henry Armah (1,2), Alfred K. Dodoo (3), Edwin K. Wiredu (2), Andrew A. Adjei (2), Richard K. Gyasi (2), Yao Tettey (2) and Jonathan K. Stiles (1), (1) Morehouse School of Medicine, Atlanta, GA 30310; (2) University of Ghana Medical School, Korle-Bu, Accra, Ghana, and (3) Noguchi Memorial Institute for Medical Research, Legon, Accra, Ghana. Although the role of systemic cytokines and their up-regulation of adhesion molecules in the pathogenesis of cerebral malaria (CM) is well established, the role of local cytokine release remain unclear. Immunohistochemistry (IHC) was used to compare the expression of ICAM-1, VCAM-1, E-Selectin, IL-1[beta], TNF-[alpha] and TGF-[beta] in cerebral, cerebellar and brainstem postmortem sections from 10 CM, 5 severe malarial anaemia (SMA), 1 purulent bacterial meningitis (PBM), 2 non-central nervous system infections (NCNSI) and 3 non-infections (NI) deaths in Ghanaian children. Fatal malaria and Salmonella sepsis showed significantly higher vascular expression of all 3 adhesion molecules, with highly significant co-localization with sequestration in the malaria cases. However, there was negligible difference between CM and SMA. TGF-[beta] showed intravascular and perivascular distribution in all cases, but expression was most intense in the PBM case and CM group. TNF-[alpha] and IL-1[beta] showed brain parenchymal staining, in addition to intravascular and perivascular staining, in only the PBM case and CM group. In conclusion, the maximal expression of all 6 antigens studied was in the cerebellar sections of the malaria cases, and IL-1[beta] and TNF-[alpha] were expressed in only cases with neurodegenerative lesions (CM and PBM), whilst TGF-[beta] is present in all cases.

3:30 IMMUNOHISTOCHEMICAL EVALUATION OF CASPASE 9 IN ORAL CANCER, Baldev Singh, J. Borke and R. Abdelsayed, Medical College of Georgia, Augusta, GA 30912. We have previously reported the role of proto-oncogene Bcl-2 and its congeners in the regulation of programmed cell death (PCD). However the caspases have been implicated to mediate PCD (apoptosis) via intrinsic or extrinsic pathways. The objective of this study was to elucidate the status of Caspase 9 (C-9) in oral squamous cell carcinoma. 5m thick sections of tumors from archival paraffin blocks were examined employing polyclonal antibodies to C-9. Immunoreactivity for C-9 was observed primarily in cytoplasm of 75% of oral tumors (total 20 specimens). Differentiating tumors exhibited varying degrees of focal reaction, whereas poorly differentiated tumors had a diffuse heterogenous reaction and focal granularity. The upstream C-9 proenzyme is activated by Apoptosome formation (Intrinsic Pathway). C-9 subsequently activates PCD inducing downstream caspase-3 also expressed in oral tumors as previously reported by us. The expression of these caspases suggests their possible role in oral cancer progression.

4:00 EXPRESSION AND FUNCTIONAL ROLE OF RANTES CHEMOKINE IN MALARIA, Bismark Y. Sarfo (1), R. K. Gyasi (2), A. A. Adjei (2), H. Armah (2), I. Irune (3), A. Quarshie (3), J. W. Lillard Jr (3), J. K. Stiles (3), (1) NMRI, Ghana, (2) UOG Medical School, Ghana, (3) Morehouse School of Medicine, Atlanta, GA, 30310. Malaria infects 300-500 million people and kills >1 million per year. The pathogenesis of malaria is mediated by complex interactions involving co-regulators such as cytokines and adhesion molecules. However, the role of chemokines remains unclear. RANTES is a chemokine involved in the generation of inflammatory infiltrates and mediates degradation of cell-cell junctions, BBB dysfunction, and chemotaxis of Plasmodium-infected RBC into and occlusion of microvessels during malaria. Activated T lymphocytes, platelets and endothelial cells also release RANTES when exposed to IRBC's. We hypothesize that RANTES mediates malaria pathogenesis and that blocking RANTES (up regulated during malaria) could minimize or abrogate the severity of the disease. We evaluated plasma and tissue expression of RANTES in a murine malaria model (SW/P. yoelii 17X) and compared results with that in human subjects with malaria. Mock and anti-RANTES blocking experiments were then performed to determine the functional role of RANTES in severity and mortality associated with murine malaria. RANTES in plasma from infected and uninfected mice as well as malaria infected (n=64) and uninfected (n=19) humans were determined by ELISA. Tissue expression was evaluated by Western blot analysis using anti-RANTES antibody. RANTES expression in plasma was upregulated 2-3 fold in both human and mice (p < 0.0001) compared with controls. Plasma levels of RANTES correlated positively with levels of P. falciparum antigens in infected humans. Parasitemia (4.2X 106/ml [+ or -] 0.2) in mock antibody treated mice was greater (p<0.06) than in mice in with RANTES blocked (1.2X106/ml [+ or -] 0.2 [+ or -] SD). Mean survival of Anti-RANTES antibody treated mice was longer (14 days) while mock antibody treated mice survived for 10 days indicating that blocking RANTES reduced parasitemia associated with P. yoelii infection and increased survival. We conclude that malaria induced RANTES mediates severity of the disease.

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Title Annotation:biological sciences
Publication:Georgia Journal of Science
Date:Mar 22, 2005
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