Abstracts of presentations and papers.
Karen E. Francl, Presiding
1:00: POTENTIATING AFFECT OF ENDOTHELIN-1 ON PHENYLEPRINE IN THE CONTRACTION OF RAT CAVERSONAL TISSUE STRIPS, Sherita James (1), J. Derek Stone (1), Linda S. James (1) and Christopher Wingard (2) Paine College (1) and Medical College of Georgia (2) Augusta, GA 30901. Causes for erectile dysfunction, consistent inability to sustain an erection sufficient for sexual intercourse, are currently under investigation. Studies have indicated that the combination of the vasoconstrictors Endothelin-1 and Phenylephrine will promote greater contraction in cavernosal tissue than will either Endothelin-1 or Phenylephrine alone. It was hypothesized that Endothelin-1 would potentiate Phenylephrine-induced contraction in isolated rat cavernosal strips. Dose responses were performed on rat cavernosal strips using Endothelin-1 and Phenylephrine. Combined agonist effects were tested with the combination of Endothelin-1 and Phenylephrine, both in the presence and absence of L-NAME, a blocker of Nitric Oxide Synthase. Independently, Endothelin-1 and Phenylephrine caused contraction of rat cavernosal tissue. L-NAME increased the contraction produced by Endothelin-1. Further, Endothelin-1 potentiated the confractile effect of Phenylephrine. An increase in force generation was observed when L-NAME was added to the combination of Endothelin-1 and Phenylephrine. Our results suggest that combined exposure to Phenylephrine and Endothelin-1 can increase the contractile response of rat cavernosal strips. These results may identify a mechanism by which these agents can contribute to some forms of erectile dysfunction.
1:15: IMMUNODETECTION AND LOCALIZATION OF THE [Na.sup.+]/[H.sup.+] EXCHANGER (NHE) PROTEIN IN THE GILLS OF A MARINE ELASMOBRANCH (SQUALUS ACANTHIAS) AND A EURYHALINE TELEOST (Fundulus heteroclitus), Jill Weakley and James B. Claiborne, Georgia Southern University, Statesboro, GA 30460. All animals require a mechanism to regulate intracellular pH. The sodium-hydrogen transporter (NHE), an ion exchanger found in the membrane of many cells, aids in the intracellular regulation of acid (hydrogen ions). We aimed to detect NHE in the gill epithelium of several fishes. We employed SDS-PAGE and western blot analysis, using species specific polyclonal antibodies which we have recently generated, to detect NHE in the gills of the dogfish shark (Squalus acanthias) and the euryhaline mummichog (Fundulus heteroclitus). A protein band was detected which corresponded to the molecular weight for mammalian NHEs. Immunohistochemical visualization of dogfish gill epithelium with the polychlor antibody against NHE2 demonstrated protein expression in a specific sub-population of gill cells. Experiments are currently underway to verify the presence of this protein in the gills of both fish species.
1:30: COMPARISON OF THE BIOENERGETICS OF THE WHITEFOOTED MOUSE (PEROMYSCUS LEUCOPUS) AND THE GOLDEN MOUSE (Ochrotomys nuttalli), Maura O'Malley, Jennifer Blesh, Michelle Williams and Gary W Barrett, University of Georgia, Athens, GA 30602-2202. This investigation focused on the food preferences and bioenergetics of the white-footed mouse (P leucopus) and the golden mouse (0. muttalli). Water oak acorns (Quercus alba), and privet berries (Ligust rum sin esis) comprised the study diet. The whitefooted mice showed significantly greater mean ingestion, assimilation, and respiration values than did the golden mice, suggesting greater patterns of activity under field conditions.
1:45: PHYLOGENETIC RELATIONSHIP OF SERIEMAS TO MUSOPHAGIDAE AND OTHER BIRD FAMILIES, Katie L. Cockeram, Catrine L. Sten mark, Robert M. Chandler and Michael L. Gleason, Georgia College & State University, Milledgeville, GA 31061. Cytochrome b sequences are being used to investigate the systematic position of the South American Red-legged Seriema (Cariama cristata) and Black-legged Seriema (Chunga burmeisteri) to the Musophagidae (turacos), Ciconiidae (storks), and Gruiformes (cranes). Genomic DNA from contour feather pith of the seriema species is amplified and then directly sequenced. Comparison of partial sequence data for the seriemas with previously described sequences for turacos and cranes supports a closer relationship of seriemas to turacos, than to the cranes with which seriemas are traditionally grouped. These data are in agreement with osteological and fossil data that previously have been reported. Further analysis of the complete sequence homology data is in progress and will be described. Evide nce that two seriema species should be reclassified into the same genus also will be presented.
2:00: BEHAVIORAL RESPONSES OF CRAYFISH (PROCAMBARUS CLARKII) TO CHEMICAL STIMULI, Mary Elizabeth Loughridge Daniel Hamby, Cecilia Trotter, Jayme Williams and Frank Corotto, North Georgia College and State University, Dahlonega, GA 30597. We sought to determine if crayfish (Procambarus clarkii) would respond behaviorally to known physiological, chemosensory (taste) stimuli. Animals were filmed while in a 1.7 L flow chamber and 10 ml stimuli were injected into the 142 mL/min flow. We tested a control blank, a mixture of cellobiose, glycine, leucine, maltose, sucrose, and trehalose (each at [10.sup.-4] M, initial concentration), and a mixture of the same compounds each at [10.sup.-2] M. Leg-sweep frequency (n=8) and search time (n=9) were both significantly elevated by the two mixtures in comparison to the blank (repeated measures 2-way ANOVA, interactions [F.sub.2,14]=5.230, P=0.020 and [F.sub.2,18]=6.445, P-0.008). Spurious antennule-flick responses (n-8) to the control blank were also significant (interaction [F.sub.2,14]=4.859, P-0.025). Search time and leg-sweep results both demonstrated behavioral responses to stimuli known to be physiologically effective for leg chemoreceptors. Antennules may posses relatively few receptor cells for these compounds.
2:15: SURVEY OF THE ECTOPARASITES OF THE WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS) IN SOUTHEASTERN GEORGIA, Currie N. Partin (1), J. Mitchell Lockhart (2) and Jimmy Wedincamp Jr. (1), Valdosta State University (1), Valdosta, GA 31698 and East Georgia College (2), Swainsboro, GA 30401. A survey of the ectoparasites of the white-tailed deer was conducted from October to January during the 2000 through 2003 hunting seasons. Deer were examined at local deer processing plants and the ectoparasites removed by combing. During the 2002-2003 season blood was collected from hunter-killed deer on Nobuto paper-filter strips, frozen, and shipped to Valdosta State University. DNA was extracted from the paper strips using a Qiagen DNA isolation kit. Nested PCR amplification was performed using TaKaRa HotStart PCR mastermix, generic primers designed to amplify any Ehrlichia species, and specific primers designed to amplify Ehr!ichia chaffeensis. Results from our study indicate infestations of Lipoptena mazamae (Hippoboscida e), Dermacentor albipictus, Ixodes scapulari, and Amblyomma americanum, Tricholiperus lipeuroides, and Solenopodes bin ipilosus. Results from the PCR analysis will be forthcoming.
2:30: PLANT CHEMICAL DEFENSE AND LEAF NUTRIENT LEVELS, Stephan Varga and Mark S. Davis, North Georgia College & State University, Dahlonega, GA 30597. We investigated the relationship between nutrient levels and chemical defense in plants. Leaves of eight plants from each of three toxic species (butterfly weed, spotted water hemlock, dog hobble) and three nontoxic species (goldenrod, joe-pye weed, muscadine) were collected, washed and blotted, then dried for 24 h at 5000. Percent nitrogen (combustion method), phosphorus, calcium, potassium, and magnesium (ICP method) were determined (blind protocol) for each species by the Soil, Plant & Water Laboratory at the University of Georgia. Data were analyzed using a nested (hierarchical) ANOVA with species nested within toxic and nontoxic groups. We found no significant difference in nutrient levels between toxic and nontoxic species and conclude that chemical defense in plants is not associated with increased leaf nutrient content.
2:45: GRAZING INFLUENCES PHYSICAL DEFENSE IN BLACKBERRIES (RUB US ARGUTUS), Stephanie Dye, Angela DeLong, Darren Hunt, Autumn Lusk and Mark Davis, North Georgia College & State University, Dahionega, GA 30597. We investigated the effect of grazing on prickle length and prickle density in Rubus argutus. Two hundred blackberry shoots were sampled, half in grazed locations and half in ungrazed locations, at eight sites in two northeast Georgia counties. For each shoot, data on prickle length and prickle density were obtained from a 5 cm section, the base of which was cut 10 cam from the terminal bud. We measured the length of the first three prickles and obtained mean prickle density in each 5 cm section. Data were analyzed with a two-way ANOVA (repeated measured) to compare the effects of location (grazed versus ungrazed) and position (1st, 2nd, or 3rd prickle) on prickle length. An unpaired t-test was used to assess differences in prickle density. Prickles were significantly longer in grazed (mean = 4.82 mm) than in ungrazed (mean = 3.81 mm) locations ([F.sub.1198] = 95.21, P<0.001) but prickle position had no significant effect ([F.sub.2,4] = 1.60, P = 0.20). No significant differences existed in prickle density between locations (t = 0.585, P = 0.56). Our results suggest that herbivory selects for enhanced physical defense by increased prickle length but not higher prickle density.
3:00: PRELIMINARY INDICATIONS OF SEXUAL DIMORPHISM IN MATURE LARVE OF ACILIUS SEMISULCATUS AUBE (COLEOPTERA: DYTISCIDAE), Tiffany A. Shepley, E.H. Barman and WP Wall, Georgia College & State University, Milled geville, GA 31061. A geometric analysis of mandibles of mature larvae and mature larval exuviae of Acilius semisulcatus revealed greater than expected variation in parameters evaluated. The analysis included exuviae collected with a pupa and five adults in pupal cells, providing a definitive identification of the exuviae and permitting sexing of the larval material. Mandibular curvature was defined using two parameters, arc and angle of attack. Mandibles of larvae that developed into males had less curvature (arc) and smaller angles of attack than those of larvae that developed into females. This project was supported in part by a Faculty Research Grant, Office of Research Services, GO & SU. Aquatic Coleoptera Laboratory Contribution No. 47.
3:15: A PREUMINARY ASSESSMENT OF CRANIAL MORPHOLOGY OF FIRST, SECOND, AND THIRD INSTARS OF AGABUS DISINTEGRATUS CROTCH (COLEOPTERA: DYTISCIDAE), USING DISTORTION COORDINATES, Devon Brannen, E.H. Barman and WP Wall, Georgia College & State University, Milledgeville, GA 31061. Larvae of Agabus disintegratus have been cultured successfully under laboratory conditions with microcrustaceans and diptern larvae as prey. Major shifts in prey regimes during development should be reflected in the morphology of the cranium and/or its appendages. A comparison of first, second, and third instar crania revealed changes in dorsoventral shape during the larval stage. Distortion coordinates (Cartesian Transformations) were used to evaluate and quantify these changes. Significant changes in cranial morphology were observed, indicating that ontogenetic shifts in prey selection and/or preferences may occur. This project was supported in part by a Faculty Research Grant, Office of Research Services, GC & SU. Aquatic Coleoptera L aboratory Contribution No. 47.
3:30: THE MORPHOLOGY OF THE MATURE LARVA OF Neoporus clypealis (HARRIS) (COLEOPTERA: DYTISCIDAE: HYDROPORINAE), Julie Scott, E.H. Barman and G. William Wolfe, Georgia College & State University, Milledgeville, GA 31061. Mature larvae of Neoporus were collected from lower Piedmont and upper Coastal Plain lotic habitats, cultured into the adult stage, and identified as N. clypealis. The larval haed is characterized by a nasale, a prominent reddish-brown dorsomedial marking, and well-developed stemmata. Mesothoracic and lateral abdominal spiracles are lacking. Chaetotaxy is comparable to that of previously described Neoporus, including tarsal and tibial natatory sensilla and short secondary sensilla on the proximal urogomphal segment. This project was supported in part by a Faculty Research Grant, Office of Research Services, GC & SU. Aquatic Coleoptera Laboratory Contribution No. 46.
3:45: PRELIMINARY INVESTIGATIONS OF THE GENETIC VARIATION OF A TREMATODE PARASITE AND ITS GRASS SHRIMP HOST ALONG THE SOUTHEASTERN COAST, Melody Flowers, Guang Xu, Oscar Pung and Quen tin Fang, Georgia Southern University, Statesboro, GA 30460. The study of genetic variation in populations of an organism provides important information concerning the origin of diversity and population parameters such as genetic drift and migration. The purpose of this study was to investigate the genetic structure of the trematode Microphallus turgidus and one of its hosts, the grass shrimp Palaemonetes pugio. Our primary objective was to develop a system
that could be used to examine the genetic variation in populations of M. turgidus and P pugio from the southeastern coast. Methods examined included an analysis of the 288S rDNA, 16S rDNA and cytochrome c oxidase subunit I (COI) genes. This was accomplished using restriction enzymes, RAPD primers, the polymerase chain reaction and single strand conformation polymorphism (SSC P). Preliminary findings suggest that SSCP analysis of the COI gene will achieve this goal.
4:00: RELATIONSHIPS AMONG SMALL MAMMAL COMMUNITIES, VEGETATION, AND LANDUSE COVERAGES IN CENTRAL APPALACHIAN WETLANDS, Karen E. Francl (1), Steven B. Castleberry (1) and W Mark Ford (2), University of Georgia (1), Athens, GA 30602 and USDA Forest Service (2), Northeastern Research Station, Parsons, WV 26287. We surveyed small mammals at 20 wetlands in West Virginia and Maryland, using Sherman traps, pitfalls, Museum Specials, and coverboards. In 24,693 trap-nights, we captured 12 mammal species. Using Pearson's correlations and canonical correlation (CANCORR) analysis, we examined relationships among mammal and vegetation/landscape measures at multiple scales. We found that meadow voles (Microtus pennsylvanicus) and shrews (Sorex cinereus, Blarina brevicauda) dominated large, open wetlands, while southern red-backed voles (Clethrionomys gapperi) were more prevalent at smaller sites surrounded by mixed forest stands. However, CANCORR's weak relationships among mammal and vegetative/landscape measures emphasiz ed that generalist mammals dominating these areas do not need specific landscape features within or surrounding the wetland to effectively use its resources.
4:15: EFFECT OF A TREMATODE PARASITE ON GRASS SHRIMP BEHAVIOR, Alyssa Kunz and Oscar Pung, Georgia Southern University, Statesboro, GA 30460. To facilitate transmission to a definitive host, parasites are thought to induce changes in intermediate host behaviors that may alter predator-prey dynamics. We tested this hypothesis by studying the impact of the trematode Microphallus turgidus on the behavior and predation of its intermediate host, the grass shrimp Palaemonetes pugio. To do so, we measured the susceptibility of infected and uninfected shrimp to predation by fish in predator selection trials. The swimming stamina of shrimp was evaluated in a flow tank and shrimp behaviors were compared in the presence and absence of a predator by scan sampling. We found that infected shrimp were more likely to be eaten by a predator and had significantly lower swimming stamina than uninfected shrimp. Scan samples suggested that infected shrimp might be more likely to swim in the presence of a predator. The results in dicate that M. turgidus increases the predation of shrimp by definitive hosts in the wild, perhaps by affecting shrimp behaviors.
4:30: EXPRESSION OF NHE3 [Na.sup.+]/[H.sup.+] EXCHANGER mRNA IN MARINE FISH GILL, Curtis E. Lanier and James B. Clairborne, Georgia Southern University, Statesboro, GA 30460. Regulation of [Na.sup.+] volume homeostasis by the mammalian kidney requires activities of a number of different [Na.sup.+] transport proteins. One of the most important is the [Na.sup.+]/[H.sup.+] exchanger isoform 3 (NHE3) due to its higher capacity for reabsorption of Na. The NHE are also present in the gills of fishes and NHE3 is believed to be one of the primary isoforms responsible for [H.sup.+] excretion in marine fish. In this study, we have used reverse transcriptasepolymerase chain reaction (RT-PCR) to detect the presence of NHE3 in the gills of marine long-horned sculpin (Myoxocephalus octodecimspinosus). A partial cDNA sequence shares homology with mammalian NHE3 isoforms. The inference from the study is that the expression of NHE3 is present in the gills of marine fish. This study represents the first detection of NHE3-like mRNA transcripts in marine fish. An examination of changes in expression of this isoform following acid-base perturbations is being investigated.
4:45: THE ROLE OF EVOLUTIONARY PROCESSES IN A BIOLOGICAL INVASION: AN EXPERIMENTAL STUDY WITH SILENE LATIFOLIA, Amy Blair and Lorne Wolfe, Georgia Southern University, Statesboro, GA 30460. Biological invasions represent one of the greatest threats to biodiversity. This project examined whether the success of invasive species may be in part due to population genetic change resulting from evolution following introduction. This hypothesis was tested using the aggressive agricultural weed, Silene latifolia. A common garden approach was used both in the field (Mountain Lake Biological Station, VA) and greenhouse (Georgia Southern University). The experimental design included ten plants grown from seed from each of twenty native (European) populations and twenty introduced (North American) populations. A number of morphological and life history traits were measured throughout the plant's life cycle. The results indicate that plants from the two regions differ, with North American populations exhibiting weedier gr owth (i.e. greater germination rates and reproductive output.
Section II: Chemistry
Marina Koether, Presiding
1:05: INTRODUCTION OF JUDGES TO UNDERGRADUATE PRESENTERS
1:15: THE HUNT FOR BRYOSTATIN, Ruth Borchelt * and Thomas Manning, Chemist ry Department, Valdosta State University, Valdosta, GA 31698. Bryostatin is a group of approximately 30 molecules that share a common bryophan ring. These high molecular weight molecules have been shown to have strong anticancer properties. Bryostatin is extracted from the marine organism bryozoa. Currently approximately 14 tons of bryozoa must be harvested to isolate 1-2 ounces of bryostatin. The synthesis of the molecule is estimated to cost approximately two million dollars per gram. Our group has focused on finding a precursor that the filter feeder bryozoa ingest and convert to bryostatin. This would simplify the synthesis dramatically. We have isolated and analyzed various sediments from the lower Suwanee River and the Gulf of Mexico, where the bryozoa live and are conducting theoretical modeling to help identify potential precursors.
1:30: SYNTHESIS AND CHARACTERIZATION OF (DICYANOMETHYLENE) ACENAPHTHENE, Nicholas M. Marshall *, Kevin P Gwaltney and Brian Wesley Williams, Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144. Fluorescent organic molecules are of interest in a variety of applications including dyes, non-linear optical materials and potential emitting layers for computer displays. In order to better understand fluorescence and fluorescent molecules, we synthesize novel compounds, and measure their absorption and emission spectra. We then compare the spectra to those that have been previously measured in this research group as well as data found in the literature. The synthesis of (dicyanomethylene)acenaphthene has proven to be a significant challenge. Attempts to synthesize (dicyanomethylene)acenaphthene will be presented along with characterization of precursors by absorption spectroscopy and emission spectroscopy as well as NMR and IR.
1:45: FLUORESCENCE STUDIES OF SOME TETRAPHENYL PORPHYRIN DERIVATIVES, Freddie Gaither*(1), James LoBue(1) and Adegboye Adeyemo(2), Department of Chemistry, Georgia Southern University(1), Statesboro, GA and Department of Natural Sciences and Mathematics, Savannah State University(2), Savannah, GA. Fluorescence excitation and emission spectra were acquired for 13 derivatives of tetraphenyl porphyrin. In most of the derivatives the four phenyl rings were modified with the following substitutions: 2,4 dimethyl, p-methyl, m-methyl, 4-amino, 2-amino, 4-chloro, 3-chloro, 2,6-difluoro, and 2,5-difluoro. In addition, four derivatives involved tetrasubstitution of the following moieties: pyrenyl, vanillin, and quinoline (2 isomers). For 9 of these derivatives the wavelengths for
maximum fluorescence lie within two relatively narrow ranges. The range for the blue, more intense line is 683 to 688 nm while the red line lies in the range 738 to 748 nm. These results are as expected by comparison with similar molecules fo und in the literature. The underivatized tetraphenyl prophyrin shows just a single peak in the red.
2:00: HIGH VOLTAGE DISCHARGE IN PRODUCTION OF ORGANIC SALTS, Emily Olsen*, Thomas Manning, Jim Nienow and Linda Chamberlin, Chemistry and Biology Department, Valdosta State University, Valdosta, GA 31698. The classic Miller-Urey experiment, of which hundreds of variations of parameters such as gas composition, pressures, and voltage have been tested, involves the production of simple amino acids and other species in the gas phase in an arc discharge. This work's emphasis is the production of various chemical species at a discharge-liquid interface. A high voltage (250 kV) discharge is arced to different solutions containing the simple molecular species of water, methanol, and ammonia. We show that the impact of the discharge at the discharge-solution interface produces a range of organic molecules including amino acids and polymers containing carboxylate, amine, imine, and cyano groups. The solid products are analyzed by FT-Raman and MALDI-MS.
2:15: THE PREPARATION, CHARACTERIZATION, AND X-RAY STRUCTURAL ANALYSIS OF DICHLOROBIS[1-METHYL-3-(2-PROPYL)-(3H)-IMIDAZOLETHIONE] MERCURY (II), Anna M. Hutchings*, Natalia E. McConnell*, Roland A. Faucher*, Donald VanDerveer and Daniel J. Williams, Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144 and School of Chemistry, Georgia Institute of Technology, Atlanta, GA 30332. A new compound of mercury (II) chloride complexed to 1-methyl-3-(2-propyl)-2(3H)-imidazolethione (mipit) has been prepared and characterized via standard methods and x-ray crystallography. The compound [HgCl.sub.2][(mpit).sub.2] crystallizes in space group P2/1c with a = 17.143(6) A, b = 17.047(6) A, c = 14.759(5) A, [beta] = 105.899(5)[degrees], V = 4148(2)[A.sup3], Z = 8. The coordination sphere is a distorted tetrahedron with Hg-S bonds and Hg-Cl bond distances falling within the normally expected ranges. Ligand bond distances and angles including the C=S distance are within the normally expected va lues observed for this compound. The structural significance of this study is that it shows one of the few nomomeric examples of a mercury (II) chloride thione complex reported to date.
2:30: PHYTOCHEMICAL INVESTIGATION OF RUMEX HASTATULUS AND RUMEX ACETOSELLA, Bethany A. Lynn *, J. Richard Carter and James T. Baxter, Valdosta State University, Valdosta, GA 31698. The steam volatile oil of two related species, Rumex hastatulus and Rumex acetosella, were analyzed using CG-MS. The patterns of total ion chromatograms of the two related species can be used in identification. In addition, several compounds in the steam volatile oils of both plants have been identified. Rumex hastatulus has been extracted using a National Institute of Health (NIH) extraction procedure. The extracts were analyzed using a CG-MS.
3:00: THE PREPARATION, CHARACTERIZATION AND X-RAY STRUCTURAL ANALYSIS OF DICHLOROBIS[1-ETHYL-3-METHYL-2(3H)-IMIDAZOLETHIONE]BISMUTH(III), Dustin R. Smith *, Jack W Long, Donald VanDerveer and Daniel J. Williams, Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144 and School of Chemistry, Georgia Institute of Technology, Atlanta, GA 30332. A new compound of bismuth (III) chloride complexed to 1-ethyl-3-methy-2(3ah)-imidazolethione (emit) has been prepared and characterized via standard methods and x-ray crystallography. The compound Bi[Cl.sub.3][(emit).sub.2] crystallizes in space group P/c with a = 17.143(6) A, b = 17.047(6) A, c = 14.759(5) A, [beta] = 105.899(5)[degrees], V = 4148(2) [A.sup.3], Z = 8. The structure consists of two distorted octahedra sharing a common edge through chlorine atom bridging. The thione ligands are trans to each other and perpendicular to the chlorine-bismuth plane. The structure is similar to the bis complex of 1,3-dimethyl-2(3H)-imidazolethio ne (dmit) except that the six chlorine and two bismuth atoms are not coplanar, and the two octahedra are canted slightly toward each other. Bond distances and angles are comparable to those observed for Bi[Cl.sub.3][(dmit).sub.2].
3:15: IMPACT OF SIZE ON THE MAGNETO CHEMISTRY OF Mn12, Jerry Purcell * (1), Thomas Manning (1), Jim Nienow (2), Micah North (3), Naresh Dalal (3) and Kim Riddle (3), Chemistry Department, Valdosta State University (1), Valdosta, GA 31698, Biology Department, Valdosta State University (2), Valdosta, GA and Chemistry and Biology, Florida State University (3), Tallahassee, FL. Mn12 ([[[Mn.sub.12] [([CH.sub.3]OO).sub.16] [([H.sub.2]O).sub.4] [O.sub.12]].sub.2] [CH.sub.3] COOH.[4H.sub.2]0) is a ferromagnetic molecular cluster with a total spin S = 10 that exhibits quantum tunneling of its magnetic moment at low temperatures. We use three novel approaches to make manocrystals of Mn12: 1. entrapment in the nanometer sized pores in the silicate shell of the marine organism diatom, 2. wrapping the clusters in the individual sheets of graphite made from exfoliated graphite, and 3. trapping the Mn12 inside single walled nanotubes. Using SQUID, we measure the blocking temperature and shift a from 2.95 K to 4.0 K. The hys teresis loop for the Mn12 cluster also shifts. These results will be presented and discussed in-depth.
3:30: BEHAVIOR OF IMAZAQUIN AT A MERCURY DROP ELECTRODE VIA CYCLIC AND SQUAREWAVE VOLTAMMETRY, Natalia McConnell * and Huggins Z. Msmanga, Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144. Imazaquin, a new class of pre-emptive herbicides called imidazolinones, is widely used to control broad-leafed weeds during the growth of soybeans. Previous studies showed that, at the platinum electrode, imazaquin gives weak peaks at very negative potentials where the support electrolyte interferes with the signal. However, at the mercury drop electrode, three distinct cathodic peaks are observed when [CH.sub.3]COOH/[CH.sub.3]COONa is used as support electrolyte at pH 2.8. Anodic peaks are observed around pH 5.4, within the potential window used. The three peaks, after studying compounds with similar structures, are due to the reduction of the pyridine group, the -N=C=, and possibly, the =C=O functions. All three peaks respond differently to pH variation, indicating that these peaks are from different functional groups. Squarewave voltammetry using a Ammel 433A Trace Analyzer potentiostat was used to quantify imazaquin in soybeans after pre-concentration via octadecyl extraction disks.
3:45: THE ROLE OF MULTIANGLE LASER LIGHT SCATTERING IN DETERMINING THE SIZE AND MOLAR MASS OF SELECT MACROMOLECULE, Michael Land *, John Elder and Thomas Manning, Chemistry Department, Valdosta State University, Valdosta, GA 31698. Multi-Angle Laser light Scattering is a technique that can be used to study macromolecules in a variety of solvents. In this study, we used the Berry, Zimm, Debye and Random Coil formalisms to study the impact of pH on naturally occurring organic matter as well as the structure of deoxyribunucleic acid. Results that include the radius of gyration, number-average molar mass, weight-average molar mass, Z-average molar mass will be reported in the talk.
4:00: POLYMERIC ALUMINUM KINETIC EXPERIMENTS USING A CARY 4000, Bridget N. Lemley * and Marina C. Koether, Department of Chemistry and Biochemistry, Kennesaw State University, Kennesaw, GA 30144. Aluminum polymeric species are suspected to be toxic in the environment and yet no substantial evidence exists to confirm this. A preliminary exercise on aluminum polymeric species would be their identification and quantification. The degradation of the polymeric species with "ferron" is known to follow first-order kinetics. Using a new Cary 4000, numerous kinetic experiments on solutions containing known concentration of the polymeric and monomeric aluminum were performed. The results described will provide an insight into the ability of the Cary 4000 and provide background and baseline data for the analysis of polymeric aluminum in the environment.
4:15: THE ROLE OF FT-RAMAN IN STUDYING PHOTOTHERMAL ENERGY DISSIPATION FROM SINGLE WALLED CARBON NANOTUBES, Laura Taylor *, Jerry Purcel and Thomas Manning, Chemistry Department, Valdosta State University, Valdosta, GA 31698. Single-Walled carbon Nanotubes (SWNT) appear as black dust when handled in bulk. Black samples are known to emit when a relatively high power laser (1-2W) is used in the Near Infrared (NIR). When irradiated with a Near Infrared laser in a Perkin Elmer FT-Raman instrument, photothermal emission is dramatic and can mask a vibrational spectrum. In this work, we will demonstrate this effect with increasing laser power and show that, when the SWNT are mixed with various salts (e.g. KBr), the photothermal emission decreases as measured by the FT-Raman instrument.
4:30: JUDGES CONVENE TO CHOOSE THE BEST PRESENTATION
4:45: AWARD PRESENTATION TO BEST UNDERGRADUATE PRESENTER
Section III: Earth and Atmospheric Sciences
Melanie DeVore, President
1:30: GRAND TETON NATIONAL PARK PALEONTOLOGICAL SURVEY, Krisha Hansel Tracy, Dept. of Biological and Environmental Sciences, Georgia College & State University, Milledgeville, GA 31061. Grand Teton National Park has many formations which are rich in fossils representing a time span of 535 million years. The 26,000 feet of sedimentary rocks have yielded a variety of invertebrate, vertebrate, and botanical fossils. These paleontological resources that occur throughout Grant Teton National Park are identified and listed as a comprehensive paleontological survey. It identifies the fossils, their locations, and the formations in which they are found in the attempt to provide a greater understanding of the richness of Grant Teton National Park's paleontological resources. This survey also encourage an awareness of the protection and management of these resources while identifying possible hazards and solutions for park officials.
1:45: PLATANACEOUS REMAINS FROM THE MIDDLE MIOCENE OF NORTH AMERICA, S. Wells (1), M.L. DeVore (1) and K.B. Pigg (2), Georgia College & State University (1), Milledgeville, GA 31061 and Arizona State University (2), Tempe, AZ 85287. The Platanaceae (Sycamore family) is richly represented in the fossil record from the Early Cretaceous through the Cenozoic. Silicified platanaceous forms including staminate catkins with in situ pollen, fragmentary infructescences, isolated fruits and leaves have been discovered in the Middle Miocene Saddle Mountain and Yakima Canyon floras of central Washington. These fossils serve as a valuable link between the permineralized Middle Eocene genera from Clarno, Oregon and extant forms. Achenes are ovoid to ellipsoid in shape, 2.5 mm long x 0.8 mm wide. Dispersal hairs subtend the achenes. It is unknown if the infructescences are elongate like those of the Eocene Tanyoplatanus or spheroid in shape like Macgin icarpa and extant species. Staminate catkins are 2-3 mm in diameter with tricolpate platanaceous pollen within elongate anthers. These remains document the first anatomical details for Miocene age Platanaceae and demonstrate that this family was an important component of the Neogene in northwestern North America.
2:00: FOSSIL FRUITS OF THE EBENALES FROM THE MIDDLE MIOCENE YAKIMA CANYON FLORA OF CENTRAL WASHINGTON, USA, R.M. Creekmore (1), Melanie L. DeVore (1) and Kathleen B. Pigg (2), Georgia College & State University (1), Milledgeville, GA 31061 and Arizona State University (2), Tempe, AZ 85287-1601. The Yakima Canyon flora of central Washington state is a Middle Miocene age locality rich in anatomically preserved fruits and seeds. Whereas some components of this flora can be closely related to modern forms, others may represent extinct genera. Twelve specimens of a particularly enigmatic fruit type have been recently discovered. Fruits are 2.5-4.5 mm across, pedunculate and top-shaped with a slightly flattened base and a pointed apex. Prominent ridges extend laterally from the fruit base to apex. Fruits are 5-8 locular with axile placentation and bear one seed per locule. Seeds are ovate and characterized by a simple integument. Fruits have septicidal dehiscence and contain dark tannins. These fruits bear a striki ng similarity to members of the Ebenales, including Ebenaceae, the persimmon family, and Sapotaceae, the sapote family, and provide further evidence of the floristic diversity of this interesting Neogene flora.
2:15: INSECT - PLANT INTERACTIONS FROM THE MIOCENE OF WASHINGTON: PERMINERALIZED LEPIDOPTERAN COPROLITES, RE. Howell (1), M.L. DeVore (1), E.H. Barman (1) and K.B. Pigg (2), Georgia College & State University (1), Milledgeville, GA 31061 and Arizona State University (2), Tern pe, AZ 85287-1601. The Yakima Canyon flora of central Washington has provided some valuable insight to insect-plant interactions in the middle Miocene. Cynipid wasp galls are known from acorns and associated with taxodiaceous foliage from the locality. Coprolites with a distinctive segmented, six-sided morphology diagnostic of Lepidopteran frasse have been discovered at the Yakima Canyon locality. The coprolites are approximately 5.0 mm long and 1.5-2.0 mm wide. They contain fragmentary plant tissues congruent to anatomically preserved plant remains in the surrounding matrix. Analysis of the composition of the coprolites will provide an opportunity to determine if these herbivorous larvae had host specific trees or whether they utilized multiple host species.
2:30: PRELIMINARY PALYNOLOGICAL DETERMINATION OF THE PALEOCENE - EOCENE BOUNDARY WITHIN THE UMATILLA NATIONAL FOREST, OREGON, Jane Ballard and Eddie B. Robertson, Rein hardt College, Waleska, GA 301 83. This study reports on the preliminary palynological reconnaissance within a Tertiary coal section in the Umatilla National Forest in northeastern Oregon. Twenty eight samples were collected over 95 meters of measured section within the Herren formation dated as Paleocene to early Eocene on the basis of plant megafossils.
2:45: VERTICAL CORRELATION OF THE PALYNOFLORAS OF THE AQUICLUDES WITHIN THE HAGERMAN FOSSIL BEDS NATIONAL MONUMENT, HAGERMAN, IDAHO, Danielle M. Jolly and Eddie B. Robertson, Reinhardt College, Waleska, GA 30183. This study reports on the continuing work delineating the distribution of diatoms, pollen and spores recovered from the aquicludes within Hagerman Fossil Beds National Monument in the Snake River Buttes near Hagerman, Idaho. Hagerman Fossil Beds is best known for the Hagerman horse, Equus simplicidens, a late Pliocene zebra-like species. An inquiry was made into the microflora of the aquicludes 200 feet stratigraphically below the deposits that contain the horse quarry. Five eighty foot vertical sections were taken through the aquicludes. A total of twenty carbonaceous paper shale samples were collected. Samples were processed by standard palynological techniques. Chi square was run on the data from the sections in order to determine if the upper beds in the sections are different in content from the bottom beds.
Deborah Freile, Presiding
3:15: LATERAL CORRELATION OF THE PALYNOFLORAS OF THE AQUICLUDES WITHIN THE HAGERMAN FOSSIL BEDS NATIONAL MONUMENT, HAGERMAN, IDAHO, Christopher T. O'Kelley and Eddie B. Robertson, Reinhardt College, Waleska, GA 30183. This study reports on the continuing work delineating the distribution of diatoms, pollen and spores recovered from the aquicludes within Hagerman Fossil Beds National Monument in the Snake River Buttes near Hagerman, Idaho. Hagerman Fossil Beds is best known for the Hagerman horse, Equus simplicidens, a late Pliocene zebra-like species. An inquiry was made into the microflora of the aquicludes 200 feet stratigraphically below the deposits that contain the horse quarry. Five sections containing a total of twenty carbonaceous paper shale samples were taken along a threemile lateral exposure of the aquicludes. Samples were processed by standard palynological techniques. Chi square was run on the data from the sections in order to determine if the samples could be correlated laterally.
3:30: IS PTEROSPHENUS SCHUCHERTI A RELIABLE LATE EOCENE BIOSTRATIGRAPHIC MARKER IN THE SE UNITED STATES?, Dennis Parmley, Georgia College & State University, Milledgeville, GA 31061. Pterosphenus schucherti Lucas is the most commonly reported palaeopheid snake in North America. It is known from Middle to late Eocene plaeocoastal deposits from New Jersey to Texas. It has been suggested recently that at least in the southeastern United States, P. schucherti may be a good Late Eocene "marker" species. The recent discovery of the co-occurrence of Pterosphemus and Palaeophis fossils in a Late Eocene site in central Georgia sheds new information on the biostratigraphic significance of P. schucherti, suggesting it should be viewed with caution as a Late Eocene biostratigraphic marker.
3:45: AN ENIGMATIC TOOTH FROM A PLEISTOCENE DEPOSIT IN GEORGIA -- IS IT HUMAN? Joel M. Sneed, 5054 Holly Hock Dr., Flowery Branch, GA 30542. A Pleistocene deposit in a Bartow County cave has yielded over 150 taxa, including fauna both extinct and extirpated, an intermingled fauna of species with more northern affinities and more southern affinities than those found in the area today. Radiocarbon dates on elements from this deposit include one of 12,470 +/- 50 YBP from the antler of a deer, Odocoileus virginianus, and another of 12,790 +/- 50 YBP from bone collagen of an extinct peccary, Mylohyus nasutus. One tooth recovered from the deposit has eluded identification, despite being examined by several specialists. This tooth, a well-worn molar, was initially identified as human, commanding the attention of many due to the age of the deposit and its association with extinct fauna. The tooth has been subjected to several macrostructure and micro-structure tests, including SEM, X-ray, and photomicrography. None o f the tests has yielded a definitive answer as to its animal or human origins. Interestingly enough, human anthropologists, who have seen the tooth, feel that it must be animal, and zooarchaeologists insist that the tooth matches no animal, living or extinct.
4:00: THIN SECTION AND GEOCHEMICAL ANALYSIS OF PLANT MATERIAL AND ROCKS FROM THE CATAHOULA FM., Phyllis Midkiff (1), Deborah Freile (1), Melanie DeVore (2), and Kathleen Pigg (3), Berry College (1), Mt. Berry, GA 30149, Georgia College & State University (2), Milledgeville, GA and Arizona State University (3), Tern pe, AZ. Thin-sections of the Catahoula Fm (Ohgocene) of Texas show well-preserved plant fragments. The plant fragments have a reddish-brown low-grade thermal maturation. Authigenic feldspars are clearly visible. Cements include chert and quartz. The rock samples are either 1) parallellaminated, very fine to fine grained, angular and sub-angular and moderately sorted, or 2) wavy-laminated, fine to medium grained sub-angular to sub-rounded and moderately to well sorted. Accessory minerals include feldspars, altered micas, zeolites and nascent glauconite. Some specimens show cementation by opal and clays- related to the diagenesis of volcanic ashes. The Catahoula Fm. has been described as a fluvio-lac ustrine to marginal marine unit. The highly variable lithology of the samples indicates multiple provenances. Some grains are volcanic in origin, others are detrital, while a few others show the undulose extinction of metamorphic quartz. Geochemical analysis shed light into the distinct provenance areas.
4:15: CHEMOSTRATIGRAPHY OF THE AVZYAN FORMATION (SOUTHERN URALS, RUSSIA), AS IT RELATES TO THE MESOPROTEROZOIC CARBON ISOTOPIC SHIFT, Alice F. Stagner and Julie K. Bartley, State University of West Georgia, Carroilton, GA 30118. There is a known carbon isotopic shift in Mesoproterozoic seawater in which [delta]13C values rose from ~0%o before 1300 Ma to around +3.5%o by 1200 Ma. To identify the nature and timing of this shift it is necessary to couple biostratigraphic and chemostratigraphic data from successions known to capture portions of this change. Through ICP analysis and isotopic data derived from mass spectrometry we have identified the Avzyan Formation (Southern Urals, Russia), which has a relative age date between 13481080 Ma, as a candidate for capturing part of the isotopic transition. Our hypothesis is that comparison with the isotopic curves from two similarly aged successions, the Dismal Lakes Group, Arctic Canada (>1270 Ma) which has a [delta]13C shift from 0%o to +2%o, and the Allamoore Forma tion, Texas (1250 Ma) which has [delta]13C values from 0%o up to +4%o, may constrain the age of the Avzyan Formation and also further refine the global isotopic curve for the late Mesoproterozoic.
Section V: Biomedical Science
Carl F. McAliister, Presiding
1:15: THERMAL CHARACTERIZATION OF PROTEIN FORMULATION USING MODULATED TEMPERATURE DIFFERENTIAL SCANNING CALORIMETRY, Aniket Badkar, Paulos Yahannes and Ajay Banga, Department of Pharmaceutical Sciences, Mercer University, Atlanta, GA 30341. Differential scanfling calorimetry (DSC) studies constitute an important role in the determination of stability and unfolding behavior of proteins. Modulated temperature DSC (MTDSC) is an extension of DSC, which involves the application of a sinusoidal heating program to a sample and the resolution of the response into reversing and non-reversing signals. This enables the deconvolution of complex and overlapping thermal processes. MTDSC represents a significant advance on conventional DSC, which involves the application of a linear heating program. The presentation will focus on the application of MTDSC in thermal characterization and development of protein formulations. Lysozyme was used as a model protein and its unfolding temperature (~72[degrees]C) along with the glass transition temperatures for lysozyme! sucrose formulations (-32 to -25C) were determihed as a function of concentration and instrument related factors.
1:30: INVOLVEMENT OF T CELL SECRETED CHEMOKINES AND CYFOKINES IN PATHOGENESIS OF AND IMMUNITY AGAINST CHLAMYDIA, Erika Barr (1), E. Okwandu (1), Y Ogunkoya (1), FO. Eko (1), J.U. Igietseme (2) and G.A. Ananaba (1), CCRTD (1), Clark Atlanta University, Morehouse School of Medicine, Atlanta, GA 30310 and Center for Disease Control and Prevention (2), Atlanta, GA 303033. Chlamydia trachomatis is the most common bacterial sexually transmitted disease (STD) worldwide. Clinical complications of Chlamydia infection if untreated may include pelvic inflammatory disease, ectopic pregnancy and infertility. Our goal is to understand the pathogenesis and immunobiology of chlamydial disease, by defining the relevant immune effectors that mediate local and systemic anti-chlamydial immunity. We tested the hypothesis that the types of cytokines and chemokines secreted during genital chlamydial infection determine the outcome of the infection. In this study purified T cells were stimulated with UV-inactivated antigen plus APCs and after 5 days immunoassayed for secreted cytokines and chemokines. Variable levels of IFN-[gamma], MCP1 and IL4 were detected. The results suggest that the nature and levels of the cytokines and chemokines elicited can influence the ability of an infected animal to clear Chlamydia by dictating the types of T cells that are recruited (Supported by PHS grants GM 08247, RR03062 and A141231).
1:45: EXPRESSION AND LOCALIZATION OF RANTES AND CORRESPONDING RECEPTORS CCR1, CCR3, AND CCR5 IN PLASMODIUM YOELII INFECTED MOUSE BRAIN, Bismark Y Sarfo, Richard K. Gyasi, Andrew A. Adjei, Shaleish A. Sin gh, James W Lillard Jr. and Jonathan K. Stiles, More house School of Medicine, Atlanta, GA 30310 and Universoth of Ghana Med. School, Accra, Ghana. Malaria causes up to 3,000,000 deaths annually. 20-30% of fatal cases are caused by severe or cerebral malaria resulting in coma, convulsions and other neurological complications. Malaria-induced inflammation and other unknown factors impact brain development and may impair cognitive function in survivors. Previous studies showed that chemokines mediate pathogenesis of severe malaria but their role in malaria-induced brain inflammation is unclear. We hypothesized that chemokines and their corresponding receptors modulate malaria-induced brain inflammation. Our objective was to characterize the role of chemokines in malaria. We analyzed alterations in chemokine/rec eptor gene expression in brains of P. yoelii infected mice using cDNA micro array screening followed by mRNA and protein expression analysis by qRT-PCR and ELISA respectively. We also evaluated effects of P. yoelii infection on brain microvascular endothelium by electron microscopy. Our results indicated that RANTES, MCP-1, MIP-2[alpha], CCR1, CCR3, and CCR5 mRNA's are upregulated at peak parasitemia and remain at steady state thereafter. RANTES protein was correspondingly upregulated by 3-fold beyond levels in controls. Distal microvessel cell membranes were degraded in infected brains but were intact in controls. Interestingly, CCR5, a cell entry cofactor of HIV-1 and its ligand RANTES, were both upregulated during the infection. We conclude that malaria-induced up-regulation of RANTES and receptor CORS, may potentially predispose the host to other pathogens such as HIV.
2:00: THE EFFECTS OF NICOTINE EXPOSURE AND CYCLICAL MECHANICAL STRAIN ON HUMAN GINGIVAL FIBROBLASTS IN AN IN VITRO WOUND HEALING MODEL, Michael Dinos, James Borke, Steven Hokett, Baldev Singh, Jurandir Dalle Lucca and Augustine Chuang, Clinical Investigation, Eisenhower Army Medical Center, Fort Gordon, GA 30905. Pathologic tooth mobility may induce greater stresses on supporting gingival fibroblasts. The effects of nicotine to wound healing are well established. The combination of nicotine and tooth mobility is not known. This study investigated the effects of nicotine exposure and cyclical mechanical strain on human gingival fibroblasts (HOF) in an in vitro wound healing model. A 3mm wound was created in a synchronized, confluent layer of HGF. Cells were grown in DMEM media with 5% FBS containing 0, 1mM, 2mM, or 4mM of nicotine. The cells were divided into 2 test groups; one exposed to 20kPa cyclical mechanical strain (3 cycles of 10 seconds strain, 10 seconds no strain per minute) the other to no strain (c ontrol). On days 1, 3, 5, 7, cells were stained with Hematoxylin & Eosin. Wound areas were found to have reduced cell migration in the higher nicotine concentrations combined with cyclical mechanical strain. This data suggests that pathologic tooth movement coupled with nicotine exposure may delay oral wound healing resulting in periodontal breakdown.
2:30: IMMUNE COMPLEXES AS A VACCINE STRATEGY AGAINST CI-ILAMYDIA, Kiantra Ramey (1), F. Eko (2) G. Ananaba (3), Q. He (2), L. McMillan (2), T. Moore (2) and J. Igietseme (2,4), Spelman College (1), Morehouse School of Medicine (2), Clark Atlanta University (3) and Centers for Disease Control (4), Atlanta, GA. Chiamydia trachomatis causes genital diseases and complications. An efficacious vaccine should elicit a T helper type 1 (Th1) response and provide long-term immunity. We hypothesized that immunizing mice with an antigen-antibody immune complex will induce a greater Th1 response than with antigen alone. To test our hypothesis, immunoglobulin antibodies were purified from immune serum and complexed with antigen. Naive mice were immunized intramuscularly with immune complex or antigen alone and challenged intravaginally with mouse pneumonitis. The course of infection was monitored by cervico-vaginal swabbing and chlamydiae were isolated in tissue culture and enumerated using immunofluorescence. Results reve aled increased levels of interferon-gamma and decreased shedding of chlamydiae in the genital tract of immunized mice. Thus, immune complexes may be a practical approach for immunizing against genital chlamydial infections.
2:45: EXPRESSION OF RHOA IN THE MOUSE FEMALE REPRODUCTIVE TRACT, Toyosi Fatunase, Esther Lee and Holly Boettger-Tong, Wesleyan College, Macon, GA 31210. The Ras homologue gene family comprises three subfamilies, including Rho, Rac and Cdc42. One subfamily member, RhoA, encodes a small protein belonging to a class of GTPases which are essential for actin assembly. RhoA is nearly ubiquitously expressed, but activation of RhoA is differentially regulated, depending on the cell type. Although RhoA function has been extensively studied in fibroblasts, the role of this protein in reproductive tract tissues remains largely uncharacterized. In the female reproductive tract, hyperplasia and hypertrophy are controlled by ovarian hormones. However, the mechanism by which ovarian hormones induce changes in target tissue cell morphology are poorly understood. It is the aim of this research to determine which cell types in the mouse uterus and vagina express RhoA; in addition, these studies will determine if RhoA is diffe rentially expressed during the estrous cycle. Estrous cycle stages will be determined by vaginal cytology and cryostat sections will be obtained from the uterus and vagina. RhoA expression patterns will be determined via immunohistochemistry and analysis of resultant slides will be performed using a Zeiss Axioplan II imaging research microscope.
3:00: ACTIN CYTOSKELETON AND THE MAINTENANCE OF [PSI.sup.+]] PRIONS IN YEAST, MyQuang T. Pham and Michael L. Gleason, Georgia College & State University, Milledgeville, GA 31061. Creutzefeldt-Jacob Disease and kuru are human prion diseases caused by the self-perpetuating PrPSC?? isoform that converts the normal isoform [PrP.sup.c] to [PrP.sup.sc]. Originally a novel discovery, it now appears that self-perpetuating states are likely to be wide spread phenomena in nature. Several prion-like isoforms have been demonstrated in the common yeast, Saccharomyces cerevisiae, with the prionic isoform of Sup35, [[PSI.sup.+]], being the best understood. Sup35 functions as eRF3 required for translation termination, but when converted from its normal isoform into a [[PSI.sup.+]] aggregate it is no longer bioavailable and suppression of termination occurs. A simple plate assay is used to investigate the maintenance of the prion in a [[PSI.sup.+]] inducible and curable yeast strain. Growth of this [ade1-14.sub.UGA] strain o n -ade media indicates suppression and [[PSI.sup.+]]'s presence, whereas lack of growth indicates translation termination and Sup35's presence. Four classes of protein have been demonstrated to influence the maintenance of [PSI+]: yeast prions, heat-shock proteins, ubiquitin system proteins, and actin-associated proteins. Interestingly, cortical actin patches have been recently implicated in [PSI+] maintenance. Here we report our direct investigation of the actin point mutations known to affect cortical patch formation by knocking out the normal actin gene and replacing it with plasmid-borne actin mutant in the adel-[14.sub.UGA] strain.
3:15: A COMPARISON OF FLUORESCENT BISPHOSPHONATE COMPOUNDS, Yasmeen I. Jilani (1), P.D. Brewer (2), T.B. Buxton (2), A.H. Chuang (2), J.C. McPherson III (2) G.G. Stroebel (1) and E.K. Urban (1), Augusta State University (1), Augusta, GA 30904 and Clinical Investigation (2), EAMC, Fort Gordon, GA 30905. NAAB ([alpha]-naphthylacetamide bisphosphonic acid) was synthesized to create a bisphosphonate with a flurescent marker. NAAB and E41 (ciprofloxacinethylbisphosphonic acid) were compared for bone-binding affinity and toxicity to cells in culture. Binding was determined following addition of NAAB or E41 to porcine femur powder, and unbound compound, remaining in the supernatant, was measured by fluorescence spectroscopy. Toxicity was determined by addition of dose-dependent equimolar concentrations of NAAB or E41 to 24h human fibroblasts in culture and measured by a decrement in cell counts on day 3. At 87.4 [micro]M, E41 showed 75% binding, versus NAAB with only 22% binding at 122 [micro]M (p < 0.05). E41 show ed toxicity at 0.163 [micro]M, NAAB showed no toxicity up to a concentration of 0.65 [micro]M. The difference in binding affinity may be due to a carboxylate group on E41 that is absent in NAAB. NAAB may be a nontoxic bisphosphonate for cell culture studies.
Section VII: Science Education
Mary Lue Walser, Presiding
1:15: TEACHING PHYSICS ONLINE USING MIMIO SOFTWARE, John M. Stanford, Georgia Perimeter College, Lawrenceville, GA 30043. The author will describe his current experiences teaching calculus-based physics using Mimio in a hybrid lecture/online course and will present the results of a survey of student opinions regarding its usefulness. Several Mimio-derived web pages will be presented and the author will demonstrate the creation of a web page using Mimio. The Mimio software package makes the presentation of mathematics on the web almost as simple as writing on a board. It also allows a smooth integration of web-based lecture material with computer simulations.
1:30: THE ART OF TEACHING: AN INTERACTIVE TEACHING/LEARNING STYLE, Patricia Adumanu Ahanotu, Georgia Perimeter College, Clarkston, GA. This session emphasizes the importance of teamwork and students' interaction in the classrooms. The presenter discusses learning theories and how they can be incorporated in teaching; other things that will be discussed include the roles of lecture, and assessment in teaching. The presenter discusses various teaching styles and classroom activities considered collabortive. The discussion will also include the different learning styles and how students can benefit from them. The presenter will also discuss good practices in teaching and qualities of effective teaching. The audience will learn about students' approaches to learning; ways to promote "Deep Learning" as opposed to "Surface Learning" approaches among students. The audience will also understand the importance of applying "Cognitive Load Theory" and "Constructivism Theory" (both learning theories) in teaching.
1:45: THE SELECTION AND TRAINING OF TUTORS FOR UNDERGRADUATE MATHEMATICS COURSES, Sandra Rucker, Clark Atlanta University, Atlanta, GA 30314. Most colleges have tutorial programs designed to assist students in undergraduate courses. Research indicates that the quality of tutoring received by students influences the retention rate. To maximize beneficial outcomes associated with tutoring, student tutors must be trained appropriately. We discuss components of an effective tutor training program. Important factors which affect the quality of tutoring sessions addressed in this presentation include the following: appropriate use of questions which elicit higher order thinking from students; time management during tutoring sessions; and tutor's knowledge of the psychology of learning.
2:15: CONSTRUCTIVIST SCIENCE TEACHING, David J. Martin, Kennesaw State University, Kennesaw, GA 30144. In this position paper, the author posits several discrepant events in scientific inquiries that can lead to different understandings and conclusions. The thinking people apply to the resolution of these events is explained in terms of Piagetian and Vygotskian theories, which inform the practice of constructivism in science teaching. Several general principles of constructivist teaching and learning are discussed including the following: (1) People learn by attaching new experiences to preexisting knowledge; (2) The resulting conceptualizations may be different for different people; (3) Student responses are examined for validity of conceptualization rather than for correctness; (4) Teachers must listen to students; and (5) Assessment of constructivist learning occurs within the context of learning. The constructivist paradigm is consistent with the National Science Education standards.
2:30: SIBLINGS UNDER THE SKIN: MESOZOIC REPTILES AND HUMANS, Joan B. Murray, Georgia Perimeter College, Clarkston, GA 30021. The Fernbank Museum of Natural History, Atlanta, GA, displays casts of the herbivore Argentinosaurus (126 feet), the carnivore Giganotosaurus (46 feet) and pterosaurs Anhanguera and Pterodaustro. Visitors can be "bone detectives" comparing the skeletons on display with their own skeletons. Other activities relate footprints and feeding habits, look at four ways to make a wing, make tail-to-head observations of adaptations of vertebrae, and compare casts and original fossils.
2:45: VALDOSTA STATE UNIVERSITY'S VIRTUAL FOSSIL MUSEUM A PALEONTOLOGISTS'S DREAM COME TRUE, Edward E. Chatelain and Cecilia S. Barnbaum, Valdosta State University, Valdosta, GA 31698. A new collection housed in the Department of Physics, Astronomy, and Geosciences at Valdosta State University containing nearly 200 vertebrate and invertebrate casts representing fossils from all over the world was recently designed into a virtual museum as http://fossils.valdosta.edu. For each geologic time period, the website provides ancient world configurations, important ancient world physiographic features, ancient world locations where fossil casts were found, a comprehensive pictorial table with thumbnails of all fossils illustrated, and multiple views of the casts themselves, with reference skeletal reconstructions where available from the literature. Although the site is still under construction, this resource has already proved itself in the administration of Historical Geology laboratories where student handling of delicate cast material provides high instructor anxiety. The potential of this site to the educational community is enormous, for it combines specimens from many museums into a single, highly comprehensive, easily accessible location.
3:00: SEXUAL REPRODUCTION IN ENGLISH IVY, Paul E. Greene, Piedmont College, Demorest, GA 30535. English ivy, Hedera helix, is one of the most popular plants used in landscaping. The plant reproduces sexually via inconspicuous flowers. These structures occur in clusters on mature stems in mid summer to early fall. The purpose of this study was to determine the typical number of bunches per cluster, number of pods per bunch, and the normal reproductive cycle chronology. Each cluster produced branched bunches upon which developed pods that ranged from 3 mm to 5 mm in diameter. Data were collected from a sample of ten clusters on mature ivy. Results indicated the average number of bunches per cluster was 11.1. The number of pods per bunch averaged 10.8. The pods dropped from the plant in late February and early March as purple "berries." This information should be useful for the casual observer who may not normally observe the reproductive aspects of the plant. It might also be very useful as an educational inves tigation because the plant is common on school campuses.
3:30: ESA 21: ENVIRONMENTAL SCIENCE ACTIVITIES FOR THE 21ST CENTURY, Matthew Laposata, Kennesaw State University, Kennesaw, GA 30144. I will profile the computer-based laboratory program for Kennesaw State University's General Education Interdisciplinary Science course. Developed with NSF funding (DUE-0088723), the laboratory program utilizes hands-on and online exercises to have students quantify and analyze their personal contributions to regional and global environmental impacts, and understand fundamental concepts in Environmental Science. The exercises are organized into multi-week modules on a common topic, allowing students to examine issues in substantial detail and gain a holistic view of complex environmental issues. The materials are available to all interested parties online, and can be utilized in both traditional and online courses. I will present an overview of the laboratory program, and provide assessment of its use in the 2001-2002 academic year by over 2,000 students. The exercises may be v iewed at http://esa21.kenneasaw.edu.
3:45: ANALYSIS OF STUDENTS' RESPONSES IN DISTANCE LEARNING COURSES, Kailash S. Chandra, Department of Natural Sciences and Mathematics, Savannah State University, Savannah, GA 31404. In the online learning course, the dialogues generated among students are considered a rich source of evaluation material for student performance. Multiple sources of data such as the quantity of posts and the quality of participation in the online discussion along with performance on course assignments and other exercises are taken into account in awarding the final grade. The author, as a member of the team of University System of Georgia, analyzed three hundred ninety students' responses in discussion in online course(s). The major categories of cognitive responses are Not Cognitive (Not.), Triggering Event (Trig.), Exploration (Exp.), Integration (Int.), and Resolution (Re.). Each category is further divided into subcategories. The analysis of these data indicated that students responses are 50.5% UR, 5.4% Trig., 31.5% Exp., 12.6% Int., and 0.0% Re. [The author expresses his sincere thanks to Mr. Tom McKlin of Georgia Institute of Technology and Dr. Catherine Finnegan of University System of Georgia for data and guidance.]
4:00: THE ESTABLISHMENT OF THE HURRICANE CREEK TRACT WILDLIFE CONSERVATION AREA, James C. Parker North Georgia College and State University, Dahlonega, GA 30597. In 1999, a 63-acre tract of undeveloped University land was made available to the Biology Department at NGCSU for student projects and various other field activities near campus. The tract is remotely located 5 miles southwest of campus along the Etowah River. Hurricane Creek flows through the property. Grant funding was obtained for the purpose of materials and equipment; students and faculty provided the labor. The following were completed or constructed over a three year period: road improvements, parking area, restroom facility, utility house, covered bulletin board, storage shed, large outdoor classroom shelter with work tables and benches, and almost two miles of nature trails. The site provides opportunities to observe and study wildlife, improve wildlife habitat (with emphasis on non-game species), and for student research. On-going activiti es include installation of bird houses, bat boxes, owl boxes, and duck boxes, control of invasive plant species, erecting brush piles, recording plant and animal diversity, stream monitoring, and wetland restoration.
4:15: STUDENT AWARENESS OF PROBLEMS WITH LITTER ON THE ENVIRONMENT, Catherine Carter, Georgia Perimeter College, Decatur, GA 30034. Each student in two separate Environmental Science classes chose a specific three tenth of a mile site on a roadway in DeKalb County. As the sites were selected, they were recorded on a large map, to insure that no site could be selected by more than one student. Each student was instructed to collect litter on three separate occasions, one week apart. After examining their litter collections, each student chose five categories into which their litter could be classified. As the students' analyses were turned in, the data was entered into an Excel spreadsheet. An analysis of the data provided information about the quantity and types of litter specific to certain areas. Students developed an increased awareness of the degree of the problem of litter on the environment. Variations in litter types and quantities could be related to the heaviness in travel on the roadway, to locatio n of convenience stores, schools, bus stops and finally to the economic environment of the location.
Section IX: Genetics Society of Georgia
Brian Schwartz, Presiding
3:00: GENETIC ANALYSIS OF TWO CONIDIAL-SHED MUTANTS OF NEUROSPORA CRASSA, Gregory J. Digby, Sara Neville Bennett and Wayne A. Krissinger Georgia Southern University, Statesboro, GA 30460. The present study examined two conidial-shed mutants which had been isolated in the Georgia Southern Neurospora Genetics Laboratory following UV irradiation. Compared to the wild type strain, these mutants fail to shed conidia when the culture tubes are inverted and sharply tapped (the tap test), whereas the conidia of wild type produce a visible could. Earlier work had shown that crosses of K-44 and E-1 to wild type exhibited 1:1 segregation, indicating single genes following Mendelian inheritance. However, no attempts to map the mutants had been made. To begin mapping, K-44 and E-1 were crossed to the Alcoy tester strain which facilitates mapping mutants to linkage groups. Failure to show linkage of either mutant to the six tested linkage groups suggested that both mutants were in the seventh linkage group (LG VII).
3:15: HEDGEHOG SIGNALING REGULATES CELL CYCLE CONTROL CURING ERYTHROID DIFFERENTIATION, Angela J. Thompson, Kristin a M. Detmer, Anna N. Walker and Ronald E. Garner, Mercer University School of Medicine, 1550 College Street, Macon, GA 31207. Inhibition of hedgehog (Hh) signaling during the differentiation of erythrocytes resulted in delayed red cell maturation. To address the underlying mechanisms, we examined the effect of the hedgehog signaling inhibitor, cyclopamine, on changes in cell number, cell morphology, cell cycle phase distribution, and the appearance of markers of red cell maturation. Cyclopamine decreased cell number by half and decreased the percentage of late erythrocytes on each harvest day. Cyclopamine altered the distribution of the cells in [G.sub.1], [G.sub.2], and S. Most notably, in the early days of development, the fraction of cells in S phase was decreased. Over the course of maturation, the erythrocyte marker, CD36, disappeared at a slower rate in the cyclopamine treated cells than i n the control cells. These results demonstrate the importance of sonic hedgehog in erythrocyte differentiation and maturation.
3:30: GENOMES TO CONTINENTS: GENETICS AND THE PEOPLING OF THE AMERICAS, Michael D. Brown, Mercer University, Macon, GA 31207. Analysis of mitochondrial DNS (mtDNA) has been a valuable tool in the study of Native American (NA) origins. Roughly 97% of NA mtDNAs belong to one of four major founding mtDNA lineages, designated haplogroups A, B, C, and D. We have recently discovered a fifth NA mtDNA haplogroup (haplogroup X). Unlike haplogroups A - D, haplogroup X is found at low frequencies in modern European populations. To investigate the origins and continental relationships of this haplogroup, we performed mtDNA RFLP and control region (CR) sequence analysis on 22 putative NA haplogroup X and 14 European haplogroup X mtDNAs. The results identified a consensus haplogroup X motif that characterized our European and NA samples. Recent European admixture does not explain the presence of haplogroup X in the New World. Coalescence time estimates range from 12,000 - 35,000 years. In NA, this lineage was largely rest ricted to northern Amerinds and, unlike haplogroups A - D, was not found in several northeast Asian/Siberian populations, raising controversy over the origins of NA haplogroup X.
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|Title Annotation:||biological and genetic research|
|Publication:||Georgia Journal of Science|
|Date:||Mar 22, 2003|
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