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Appalachian Student Research Forum

Office of Research and Sponsored Programs

Division I

Abstracts Submitted:Division I - Undergraduate students - Natural Sciences & Mathematics


CHRONIC WASTING DISEASE IN WHITE-TAIL DEER POPULATIONS WITH A FOCUS ON THE IMPACT IT COULD HAVE FOR THE STATE OF TENNESSEE

Georganna Jenkins and Dr. Leonard Robertson, Department of Biology, East Tennessee State University, Johnson City, TN 37614

Although many people have heard of the now infamous Mad Cow Disease, many are still unaware that there are other prion diseases that fall into the same category of transmissible spongiform encephalopathies. One of these diseases of the cervid variety, is decimating herds in the western United States and Canada, and has recently been detected on the eastern side of the Mississippi River in Wisconsin and Illinois. Unlike Mad Cow Disease, Chronic Wasting Disease is thought to be spread between deer by head to head contact through saliva, urine, and feces. White-tail deer seem to be especially succeptable because they are extremely social animals. Although there have been no confirmed cases of a human contracting the disease from eating venison or being in contact with infected deer, experts are still divided as to whether this could or may already have occurred. By being too alarmist on the issue, state economies and wildlife agencies could suffer huge losses. On the other hand, many point to Englands denial that Mad Cow could infect humans, which later proved to be a devastating falsity. Our study focused on the history of cervid spongiform encephalopathy, its current pattern of spreading, the extent to which testing is being done to detect the disease, the link with bovine spongiform encephalopathy, and the controversy over whether or not this disease could be transmitted into humans. In order to obtain field experience and data from Tennessee, we were able to assist Dan Gibbs of the Tennessee Wildlife Resources Agency in collecting brain samples from deer brought to a big-game check-in station in the Fall of 2003. These samples were sent to a laboratory in Athens, Georgia for analysis. As to date, Tennessee has reported no cases of cervid spongiform encephalopathy.


INSECT SUCCESSION ON A CARCASS IN EAST TENNESSEE

Jasmine Patterson, Heather McElyea and Dr. Karl Joplin, Department of Biology, East Tennessee State University, Johnson City, TN 37614

Insects are an integral part of the decomposition process of any organism. Today, many forensic entomologists use insect succession to determine the post mortem interval of a victim. Succession is the idea that as each organism feeds on the body it changes the body making it more inhabitable for the next group of organisms, and so on. This is a predictable process, with different organisms occupying the body at different times. Controlled studies on the succession of insects in the decomposition process can be applied to real life situations to help determine time of death. The aim of my research is to establish an entomological succession of insects involved in decomposition in this area. I will be looking at which insects are involved in decompostion, what time they arrive, and how long they feed. These measurements will be made to establish a timeline of development of each species involved in decompostion. I will then compare the data I collect to succession studies collected from the Knoxville area. I will be looking for variations in the species involved in the decomposition process between the two areas.


DIAPAUSE-SPECIFIC GENE EXPRESSION IN SARCOPHAGA CRASSIPALPIS

Abigail Mabe, Karl Joplin and Hugh Miller, Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614

Many insects have an alternative life stage, termed diapause, which allows them to survive under stressful environmental conditions, such as the cold winter months. For the flesh fly, Sarcophaga crassipalpis, this stage is optional and entrance into it is based on a circadian-gated window that can be experimentally controlled by manipulating day length. Genes expressed in head-enriched tissue, especially the brain, of diapausing and non-diapausing S. crassipalpis pupae were examined by a heterologous microarray using RNA probes against a Drosophila gene set. Genes of interest were chosen from the microarray for further analysis. Two genes indicated in microarray and used in this research include 1)LD05703 termed transcriptional repressor (TR) and indicated as up regulated in diapause and 2) LD08743 termed Eb1 microtubule binding protein and indicated in the down-regulation of the syndrome. cDNA products were isolated and amplified using reverse transcriptase-polymerase chain reaction techniques then cloned in chemically competent E. coli cells. Isolated colonies were grown and plasmid DNA was purified for restriction enzyme analysis. Restriction digests with EcoR1 revealed presence of inserts and successful cloning of gene of interest. Attempts to isolate TR were successful and the gene was verified from the microarray as being involved in up-regulation of diapause. However, cloning and sequencing attempts have so far been unsuccessful. Eb1 was successfully isolated, cloned and sequenced. Eb1 was characterized as diapause down-regulated, as indicated in preliminary microarray. Determining the specificity of the indicated target genes in the flesh fly will greatly expand the information known about the genetic pathways controlling the developmental state and has future implications for understanding genes involved in other cellular processes, particularly those relating to aging and life span.


ISOLATION, AMPLIFICATION, AND ANALYSIS OF A PUTATIVE GENOMIC DNA CLONE FOR A GLYCOSYLTRANSFERASE IN GRAPEFRUIT ( CITRUS PARADISII)

Alisha Glass, Dr. Lee Pike, and Dr. Cecilia McIntosh, Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614

All higher plant species make flavonoids, chemicals that serve critical functions in plant life cycles. Some of the functions of these phytochemicals include protection of plant exfoliation from UV radiation, production of plant coloration, signaling of bacterial and fungal symbionts, and response to pathogen or insect-induced wounding. Many of the flavonoid compounds have medicinal value as well. Several flavonoids are used commercially as natural taste enhancers. Naringin is the flavonoid responsible for the bitter taste in grapefruit. Most flavonoids are glycosylated by specific glycosyltransferase (GT) enzymes. Grapefruit plants contain novel flavonoid GTs; this project was designed to obtain a genomic clone for one of these putative grapefruit GTs. Genomic DNA was isolated from the leaves of young grapefruit seedlings, PCR-amplified using primers developed from partial cDNA clones, and cloned into pCR4-TOPO vector. The samples were then sent to the UTK Sequencing Center to be sequenced. The authenticity of the GT sequences was verified with NCBI Blast and FASTA searches. Sequences for the DNA clone were compiled and compared to the cDNA clone using BioEdit and other computer software. Analysis of the nucleotide sequence for the GT included determination of the number and location of any introns present, approximate length of the protein, and the possible occurrence of alleles or pre-translational modification. From the nucleotide sequence for the DNA and cDNA clones, an amino acid sequence was established. The amino acid sequence was used to reveal possible structural and functional properties for the GT enzyme.


PROPOSED SIGNIFICANCE OF THE INSULIN RECEPTOR DURING DIAPAUSE OF SARCOPHAGA CRASSIPALPIS

Neem Bhatt, Dr. Karl Joplin and Dr. Hugh Miller III ;Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614

Diapause, an alternate life stage much like hibernation, is used by temperate insects to avoid harsh environmental conditions. By entering diapause, flesh flies are able to live 70-80% longer by implementing lowered metabolic rates and consumption of fat reserves. In Sarcophaga crassipalpis, circadian rhythms received by the developing larvae controls induction of diapause in the pupal state. This facultative induction of this optimal developmental state makes this insect a valuable experimental model system. Amicroarray experiment, examined the level of gene expression in non diapausing and diapausing pupae of S. crassipalpis. Ecdysone receptor (EcR) which promoted growth and molting was down regulated in diapause. It was hypothesized that the insulin-like proteins and their receptors might have significant effects in ecdysteroidogenesis of insects because of their essential roles in insect embryonic development and aging processes as are seen in the dauer larvae formation in Caenorhabditis elegans. When InR was knocked out of C. elegans the development at dauer larvae formation was arrested but allowed the larvae to live longer. Although insulin receptor was not inthe microarry data RT-PCR reactions demonstrated that the insulin receptor was up-regulated in diapausing pupae. The up regulation of insulin maybe involved in controlling the lowered metabolic rates and increased longevity in the S.crassipalpis pupae.


INFRARED VARIABILITY OF VERY LATE AGB STARS AND POST-AGB OBJECTS FROM THE DIRBE DATABASE

Rachel Baker and Dr. Beverly Smith, Department of Physics, Astronomy, and Geology, East Tennessee State University, Johnson City, TN 37614

We have extracted light curves from the Diffuse Infrared Background Experiment (DIRBE) database at wavelengths ranging from the near-infrared (1.25 mm) to the far-infrared (240 mm) for a sample of 89 sources with very red IRAS (Infrared Astronomical Satellite) colors. We have made a confirmed measurement of infrared variability (0.290.07 magnitudes) for one of the stars-QX Pup- at 25 mm flux density, and through inspection of the DIRBE light curves, we suspect infrared variability for another- GLMP 1048. Most of the objects in our sample have characteristics that indicate they are very late AGB stars and post-AGB objects. A large portion of our sample have been identified as non-variable post-AGB OH/IR objects, which supports earlier assertions that before a star becomes a planetary nebula, OH/IR stars become non-variable.


POLYACETALS AS BIODEGRADABLE POLYMERS

Amy J. Gauvreau and Tammy A. Davidson, Department of Chemistry, East Tennessee State University, Johnson City, TN 37614

Biodegradable plastics have received much attention in the last few decades. They differ from recyclable plastics in that they will degrade into non-hazardous materials usually under normal environmental conditions. This project focuses on the synthesis of polyacetals and the subsequent use of these materials as biodegradable polymers. Polyacetals have good potential as biodegradable polymers in that they are quite stable under basic and neutral pH conditions but will readily degrade under acidic conditions. We have conducted model studies on the formation of acetals from benzaldehyde and ethylene glycol, and have repeated a literature synthesis of a spiro-polyacetal. A drawback of the spiro polymers is that they are very rigid and virtually insoluble in most organic solvents. Our current work involves synthesis of a flexible tetrol to be used in the synthesis of various polyacetals. The flexible tetrol should give better processibility to our resulting polyacetals.


MATHEMATICAL RETENTION: ARE STUDENTS LEARNING OR MEMORIZING?

Holly Gragg, Sarah Patton and Dr. Carey R. Herring, Department of Mathematics, Carson-Newman College, Jefferson City, TN 37760

Using the Tennessee Curriculum Frameworks for Algebra I, we compiled a fifty-five question multiple-choice test of algebra problems, paying exclusive attention to material that supposedly was covered in Algebra I. We also prepared an eleven-question survey to accompany the test in which we asked about their learning styles and the teaching methods to which they had been exposed. To achieve our sample, we tested ninety-two students enrolled in Advanced Placement calculus courses in four area high schools. The students were tested within a two day time period, with none of the students knowing that the test was going to occur, and none of the teachers having prior access to the test. Also, we replaced their calculators with simple function calculators. The students were also asked to indicate after each problem if that concept was learned in Algebra I. We examined those problems for which less than 60%of the students answered correctly. The overall mean score on the test was 72.52% correct answers with a standard deviation of 10.31, or ten to twenty-one wrong answers. Students seemed to miss questions based on careless reading of problems and a lack of comprehension of terminology. Students who reported that they frequently used mnemonic devices (e.g. FOIL) to learn mathematical concepts scored significantly lower than those who did not rely on such devices. We also discovered that students atone of the four schools scored significantly higher than those at the other three. When we looked within our survey for possible reasons why this occurred, we found a significant difference in audio and tactile learning styles. We found no significant difference between the scores of males and females.


The Effect of Solvent and Temperature on the Concerted, One-Electron Reduction of Iodinated Aromatic Compounds: Environmental Influences on a Dissociative Electron Transfer.

Grant N. Holder and Jill M. Tierney, Department of Chemistry, Appalachian State University, Boone, NC, 28608-2036

The cyclic voltammetric reduction of 4-iodoacetophenone, 1-(4-iodophenyl)decan-1-one, 2-iodoacetophenone, 1-ethyl-4-iodobenzene, and other I-substituted aromatics in various solvents display an ECE mechanism following radical anion formation. Unlike other acetophenones with ring-bound halides, the 4-iodo compound displays bond-breaking in a single step as concomitant with the formation of the radical anion. This appears to occur only a low scan rates (reaction driving force), with a switch to a stepwise mechanism at higher scan rates. The affect appears dependent on temperature, solvent, and structure, solvent, with a loss of concerted-to-stepwise transition observed at low temperatures, greater solvent polarity, and for smaller molecules.


EFFECTS OF DIFFERENTIAL TRAINING ON THE EXTINCTION OF THE HONEY BEE TIME-MEMORY

Jonathan Humberd and Darrell Moore, Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614

The honey bee is well known for its time-sense which permits the forager bee to precisely associate the time of day with the presence of a food reward. In nature, the circadian time-sense governs the bees ability to anticipate the species-specific, optimal time of day when flowers produce nectar. Many previous studies have determined that bees can be trained to collect food at virtually any time of day and return to the food source at the appropriate time on test days when the food has been removed. This time-memory lasts for several days. Most previous studies have treated the honey bee time-memory as a population response and therefore have not analyzed the phenomenon from the perspective of the individual forager. Our goal was to determine if varying the number of days of training at a fixed time of day would have an effect on the rate of extinction of the time-memory. Our working hypothesis is that increasing the number of pairings of food with time of day should increase the strength of the association and cause the extinction to slow. We trained bees to collect sucrose from feeding stations located 100 meters from the colony. The original foragers at the station successfully recruited other foragers that had no previous experience at the station. Newly recruited bees were individually marked so that we could monitor the timing and exact number of rewarded arrivals at the training station. Using this approach, we generated groups of bees with different numbers of days of training. Previous research in our lab has indicated that it is the number of days of training and not the number of rewards per day that determine the time-memory. We then discontinued training and monitored the arrivals of our trained foragers at the unrewarded feeding station for several days. The results show that extinction rates are considerably slower for bees with more days of training. Furthermore, if rain occurs during the second test day in a sequence of either 3 or 4 consecutive test days, the process of extincti


USE OF ITSrDNA SEQUENCES TO RESOLVE PATTERNS OF SPECIATION IN THE GENUS SEMPERVIVUM

Kellie Burke and Kevin Jones, Department ofNatural Sciences, UVa's College at Wise, Wise VA24293

Sempervivum are a genus of succulent alpineplants that are native to mountain ranges from Morocco to Turkey. Species-level distinctions among Sempervivum remain obscure. DNA sequences derived from the internal spacer regions of rDNA are being used to develop aphylogenetic species concept for Sempervivum. ITS sequences were generated for twelve collections, representing eight distinct morphological species, and three outgroup taxa. In aligned sequences, the degree of nucleotide polymorphism is low, and apomorphic sites are unequally distributed. Nevertheless, parsimony analyses indicate a complex pattern of allopatric speciation through the mountain ranges of Europe and North Africa.


Superstring Theory and Optical Unification

Kristin R. Stone and Dr. Beverly Smith, Department of Physics, Astronomy, and Geology, East Tennessee State University

String Theory has been a more promising candidate for the theory of everything (TOE) than any other theory for many years. However, String Theory provides no prediction of the MSSM (Minimal Supersymmetric Standard Model) unification scale. As predicted by the MSSM, the three GUT forces will unify at an energy of 2.5e16 GeV, the MSSM unification scale. String Theory predicts that this unification will occur at a scale of 5.0e17 GeV, the weakly coupled heterotic string scale. To bridge this gap it is postulated that there is a set of intermediate particles that act as a diverging lens. A model containing a set of intermediate particles was discovered. When the output data was analyzed, considering only abelian groups, necessary conditions for flat directions were violated. Further investigation into the non-abelian, hidden sector, groups will hopefully prove the model to be a success.


THE RELATIONSHIP BETWEEN BETULA UBER AND BETULA LENTA

Joshua Belcher, Margie Tucker, and Kevin Jones, Department of Natural Sciences, University of Virginias College at Wise, Wise VA, 24293

Betula uber, the Virginia Round Leaf Birch, is a rare species of birch, characterized by circular leaves. Indigenous to Southwest Virginia, B. uber was the first woody plant to be placed on the Federal Endangered Species list. The true taxonomic status of this species has been ambiguous from the time of its discovery. We isolated DNA from B. uber and B. lenta, the Sweet Birch, and the Intervening Transcribed Spacer (ITS) regions of the DNA were amplified and sequenced. B. uber proved to be identical to B. lenta in the ITS region. Identity of these two trees sequences supports the argument that B. uber is a variety of B. lenta and does not warrant species status.


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