Poster Sessions - Ground Floor

Ground Floor #1

Atelier InSite Life Science Collaboration
Sabra Buckaloo, Ashley Davis, JL Garofalo, Mariana Hay, Jena Heaton, Stephen Farrow, Debbie Jacobs, Amy Justice1, Brittany Lamont2, Gracie Lathrop3, Chipper McCall3, Kep Pate3, Kayla Smith1, Emily Sorgenfrei3, Victoria Tanenbaum1, and Jonathan Windham4
Departments of 3Art, 1Biological Sciences, 4School of Agricultural, Forest and Environmental Sciences – Horticulture, and 2Public Health Sciences
Faculty Mentors: David Detrich, Denise Detrich, and Joey Manson

ABSTRACT: Students enrolled in both the Art and Life Science programs are engaged in a new paradigm for implementing public art on university campuses by collaboratively participating in a direct, hands on process to determine artwork placed in the new Life Sciences facility by capitalizing on a cross-disciplinary, inclusive approach that is predominately student driven. Students investigated the design build process, conducted site analysis, and identified site locations for the implementation and stewardship of site specific artwork for the Life Sciences facility. Potential sites were narrowed down to three locations based upon an allotted budget. Location one is a potential site for a diptych wall art located on the top and middle floor of the building. Location two is a potential site for a 3D sculpture in the lobby area in front of the conference room on the middle floor. Location three is the Atrium area on the ground floor where a potential sculpture could be placed. A possible fourth site is being considered outdoors at the Life Sciences facility.

Ground Floor #2

1, 25-dihydroxyvitamin D3 modulates fat metabolism and prolongs C. elegans lifespan under heat stress
Jessica Dinh, Sara Smith, Sujay Guha, Min Cao1, and Yuqing Dong1
Department of Biological Sciences, and 1Institute for Engaged Aging
Faculty Mentor: Dr. Yuqing Dong 

ABSTRACT: Cholecalciferol, commonly known as Vitamin D3, is the physiologically active form of the secosteroid hormone responsible for calcium and phosphate absorption in humans. An increasing amount of evidence has suggested that supplementation of Vitamin D3 may provide health benefits, along with subsequent prevention of various diseases. Here we utilize Caenorhabditis elegans as a model to examine the beneficial effects of Vitamin D3. Our Nile red staining assay revealed that dietary Vitamin D3 supplementation reduced fat storage in C. elegans, in a dose-dependent manner. The role of Vitamin D3 in fat metabolism yields significant promise in approaching the escalating fat-related disease epidemic, such as obesity and cardiovascular disease. In addition, supplementation of Vitamin D3 significantly prolonged C. elegans lifespan under heat shock, implicating the beneficial effects of Vitamin D3 on stress resistance. Since Vitamin D3 induced gene expression and regulation is mediated by a nuclear receptor, we are currently identifying its corresponding nuclear receptor in C. elegans. Undoubtedly, identifying the Vitamin D3 hormone receptor in C. elegans will allow a more articulate understanding of the complex mechanisms involved in Vitamin D3s actions.

Ground Floor #3

Effect of invader litter chemistries on soil organic matter composition: consequence of Polygonum cuspidatum and Pueraria lobata invasions
Mioko Tamura and Nishanth Tharayil
School of Agricultural, Forest, & Environmental Sciences
Faculty Mentor: Dr. Nishanth Tharayil

ABSTRACT: Due to high resource use efficiencies, invasive plants often input tremendous litter biomass to soil as the precursor of soil organic matter (SOM) and energy for microbes. We hypothesized that invaders with unique litter chemistries would alter SOM composition and stability and tested this hypothesis using the sites of Japanese knotweed (Polygonum cuspidatum) and kudzu (Pueraria lobata) invasions, representing recalcitrant vs. labile litters, respectively. Biomarker analysis indicated that polyphenol rich knotweed invasion increased soil C by selective preservation of the litter from microbial degradation, while N-rich kudzu reduced C, inducing priming of indigenous Pinus litter decomposition. However, knotweed derived C was more prone to chemical oxidation, the proxy for biological degradation, whereas kudzu soil sustained higher fraction of C, suggesting higher stability of microbial re-synthesized SOM. The findings supported our hypothesis and implied the significance of plant invasion in climate change as it may influence the overall soil C cycling.

Ground Floor #4

A Disturbing Hypothesis: The effects of competition and predation on coral cover in the Florida Keys
Kylie Smith1, Kelsey McClellan2, and Brandt Quirk-Royal1
Department of 1Biological Sciences, and 2School of Agricultural, Forest, & Environmental Sciences –  Environment & Natural Resources
Faculty Mentor: Michael Childress

ABSTRACT: Coral reefs are threatened by increasing competition and predation. Many scientists say the overharvesting of corals by parrotfish has damaged the corals so severely that they are unable to survive, allowing macroalgae to dominate ecosystems. Fleshy macroalgae species can out-compete coral species for essential nutrients. The intermediate disturbance hypothesis demonstrates how coral species should respond to varying intensities of competition and predation. We predicted that coral diversity would be highest when disturbance is at an intermediate level. We conducted field surveys of coral, macroalgae, and parrotfish densities at 16 patch reefs throughout the Florida Keys National Marine Sanctuary. Live coral cover tended to be high at intermediate abundances of parrotfishes, but was not significant. Macroalgae abundance was positively correlated with total parrotfish abundance and was highly significant. To further test this hypothesis, we will conduct caging studies at each site with different treatments of macroalgae cover and parrotfish exposure.

Ground Floor #5

Acetyl-CoA Carboxylase Links Lipid Metabolism and Immune Evasion in African Trypanosomes

Sunayan S Ray, Ciara Anderson Mcknight, Kimbely Paul
Department of Genetics & Biochemistry
Faculty Mentor: Dr. Kimberly Paul

ABSTRACT: Trypanosoma brucei, a lethal unicellular parasite transmitted by the tsetse fly, infects the bloodstream and cerebrospinal fluid of humans, causing African sleeping sickness. In addition to antigenic variation of its surface glycoprotein coat, T. brucei employs a secondary immune evasion tactic: the upregulation of endocytosis to clear lytic cell surface immune complexes, a strategy that likely involves membrane turnover and fatty acid synthesis (FAS). Acetyl-CoA carboxylase (ACC) catalyzes the first committed step of FAS and is a control point for regulating FAS. ACC RNAi, we observed a significant reduction in fluid phase (88%) and receptor-mediated endocytosis (87%). ACC RNAi caused delay in surface antibody clearance and 42% increase in complement-mediated lysis. ACC RNAi resulted in a significant 42% increase in complement-mediated lysis. Examination of ACC regulation revealed that only insect form parasites exhibited a 2-fold increase in ACC protein and enzymatic activity and decrease in phosphorylation in low lipid media.

Ground Floor #6

Allelic variation in the melanocortin 4 receptor gene in poeciliid fishes
A. Tyler Collins, Courtney T. Ward, Hannah E. Warren, and Elizabeth C. Lange
Department of Biological Sciences
Faculty Mentor: Margaret B. Ptacek

ABSTRACT: Many fish species, including swordtails (genus Xiphophorus) and mollies (genus Poecilia) demonstrate predictable mating strategies based on body size; large males court females, while small males sneak copulations. Recently, mutant duplicated alleles of a gene (mc4r) encoding melanocortin 4 receptor protein have been implicated in regulating time to maturation and male size at maturity in swordtails, thus affecting male mating strategy. We suspect this same genetic phenomenon occurs in other poecillid fishes, as males of a number of species exhibit a wide range of size at maturity and similar size-associated alternative mating strategies as swordtails. For our study, eight species of genus Poecilia were screened for mutant mc4r alleles. Vector cloning and DNA fragment analysis revealed the presence of mutant mc4r alleles in both males and females. Further studies will investigate the effect of mc4r copy number and cell function to determine if regulation of male body size is conserved.

Ground Floor #7

Barn Swallow Predation of Fly Pests Around Cattle: Climate Change Asychrony?
Claire Stuyck1, Ron Johnson1, and William Bridges2
1School of Agricultural, Forest, & Environmental Sciences, and 2Department of Mathematical Sciences
Faculty Mentor: Ron Johnson

ABSTRACT: Barn swallows, cattle, and various fly species have lived in close association for >2,000 years. Flies breed in manure and are harmful pests of cattle. Barn Swallows consume flies (~82% of nesting diet) and likely disturb fly activity. We are investigating whether swallows might be enhanced to offer an additional tool to reduce fly impacts. Climate change, however, may differentially affect flies that respond largely to temperature and swallows that migrate and respond to photoperiod. We are using Barn Swallow nesting records, from citizen science databases, and growing degree-days (GDD) to predict swallow nesting in relation to fly emergence. We expect nesting occurs when sufficient flies are present as a food resource. If GDD indicate high fly populations prior to swallow nesting, then asynchrony between swallows and flies would be suspected. Proportional hazards analysis indicates that GDD are a stronger indicator of when Barn Swallows nest than Julian days. This initial result will allow more precise tracking of swallow nesting and comparisons with fly emergence over time.

Ground Floor #8

Analogue Development of Inhibitors of an Essential Trypanosoma brucei Hexokinase
Michael Harris1, William Mitchell2, Elizabeth Kahney1, Kevin Dao1, April Joice1, Jennifer Golden3, Elizabeth Sharlow4, Jeffery Aubé4, and James Morris1
Departments of 1Genetics & Biochemistry, and 2Biological Sciences (Clemson Univ.), 3Specialized Chemistry Center (Univ. Kansas), 4Department of Pharmacology (Univ. Virginia), and 4Drug Discovery Institute (Univ. Pittsburg)
Faculty Mentor: James Morris, PhD

ABSTRACT: Hexokinase (HK) is the first enzyme in the glycolytic pathway and is essential to the survival of Trypanosoma brucei, the causative agent of African sleeping sickness. Through an optimized high throughput screen of over 220,000 unique chemical compounds, two structural scaffolds were identified as interesting inhibitors of TbHK1. These two scaffolds classes, which contained isobenzothiozolenones and benzamidobenzoic acids, were the starting point for further structure-activity relationship (SAR) determination. This project investigates the effect of structural differences within the benzamidobenzoic acids on enzyme inhibition. Eleven second-generation benzamidobenzoic acids were tested and a promising inhibitor of TbHK1 was identified (KU2354) (IC50 = 0.28 uM). Furthermore, KU2354 been shown to be cytotoxic to blood-stream form parasites (BSF), the infectious life stage of the parasite. This makes KU2354 an interesting structural scaffold from which further refinement and possible treatments of African sleeping sickness could be found.

Ground Floor #9

Analysis of Ago2 and RhoGDI Proteins in Morphologically Normal and Abnormal Porcine Sperm Using Digital Image Processing Software
S.M. Calcatera1, A.M. Minton3, W.C. Bridges2, N. Korn1, M. Owens1, S. Ellis1, and S.L. Pratt1
Departments of 1Animal & Veterinary Sciences, 2Mathematical Sciences, and 3P.I.C. North America
Faculty Mentor: Dr. Scott L. Pratt

ABSTRACT: Advancements in digital imaging allow for the examination of sperm features that would normally go undetected using standard semen evaluation procedures. Objectives were to examine histological profiles of two peptides and nuclear staining within sperm heads from boar ejaculates that were classified as morphologically normal or abnormal. Immunofluorescent detection of Ago2 and RhoGDI was performed, nuclei labeled, slides examined using a Leica LMD6000, and multispectral imaging performed using Nuance. Spectral channels underwent automated feature quantification in CellProfiler. Data were analyzed in JMP and logistic regression was used to develop a model in which parameters predicted classification as normal or abnormal. Specific parameter combinations classified >80% of sperm into the correct group. Results show that digital image processing of peptide markers can detect differences in sperm heads that are not readily detectable using standard semen analysis procedures and may provide a means for increased accuracy and precision in semen analysis.

Ground Floor #10

Application of Bacteriophages to Dairy Slurry Contaminated with E. coli O157:H7
Muthu P. Dharmasena, Spencer Herringa, and Xiuping Jiang
Department of Food, Nutrition & Packaging Science
Faculty Mentor: Dr. Xiuping Jiang

ABSTRACT: Bacteriophage treatment can be used to control enterohemorrhagic Escherichia coli O 157:H7, which is commonly found in dairy waste. A mixture of three rifampin resistant E. coli O 157:H7 strains was inoculated into fresh dairy manure slurry at 6 log CFU/ml. Equal amounts of six specific bacteriophages were added to inoculated slurry to achieve MOI of 100 and 1000. E. coli O 157:H7 was enumerated on tryptic soy agar (with 100 µg/ml Rifampin) at selected intervals in winter and summer. Background aerobic mesophilic count for winter slurry was ca.5.8 log CFU/ml and the E. coli O 157:H7 population was significantly reduced for MOI 100 and MOI 1000 compared to control sample. The level of background aerobic mesophiles was ca.7.8 log CFU/ml where the fecal bacteria were ca. 4.9 log CFU/ml for summer slurry and reduction of E. coli O 157:H7 population in treated samples was not significant compared to control.

Ground Floor #11

Araucana Chicken as a Model for DiGeorge's Syndrome
Rachel Bernstein, Nowlan Freese, Hilary Denny, and Susan Chapman
Department of Biological Sciences
Faculty Mentor: Susan Chapman

ABSTRACT: Digeorge’s Syndrome is caused by a deletion of a segment on chromosome 22 in humans, resulting in a wide array of symptoms including: heart defects, hearing loss and craniofacial defects. Approximately 1 in every 2,000-4,000 live births is affected by Digeorge’s syndrome. This deletion is usually not inherited, but rather is due to a de novo mutation. No single gene has been definitively identified as the cause of DiGeorge’s syndrome. However, Tbx1, a gene that is deleted in DiGeorge’s syndrome, is a candidate. To better understand the mechanism of DiGeorge’s syndrome, we have used the Araucana Tufted chicken as a model organism. We have mapped the tufted mutation to a 60Kb region on chromosome 15 containing Tbx1. Phenotypes of tufted Araucana that are similar to those of DiGeorge’s syndrome are craniofacial defects, decreased hearing, and heart defects. We are investigating the tufted Araucana phenotype as a model for DiGeorge’s syndrome.

Ground Floor #12

Comparative Diet Analysis of Coyotes (Canis latrans) and Red Wolves (Canis rufus)
Sloane Wiggers1, Olivia Souther1, Cady Etheredge2, and Greg Yarrow2
2School of Agricultural, Forest, & Environmental Sciences
1Department of Biological Sciences 
Faculty Mentor: Cady Etheredge 

ABSTRACT: Top predators affect the biodiversity of an ecosystem through top-down effects, or the regulation of mesopredator and herbivore populations. In areas of the Southeast where red wolves (Canis rufus) were once the top predators, mesopredator populations have flourished. Recent appearances of the coyote (Canis latrans) in the Southeast imply a potential for coyotes to fill the ecological niche left by red wolves. A comparative diet study is being conducted by analyzing more than 400 samples of coyote scat collected from the Yawkey Wildlife Center in Georgetown, SC from 2009-2011, whose results will be compared to the documented diet of red wolves. If no significant diet overlap is observed then it could be assumed that coyotes have not assumed the functional role of the red wolf. A significant overlap in the canid diets might indicate that the coyote is filling the role of top predator.

Ground Floor #13

Binding affinity of antidepressants to the serotonin reuptake transporter as a predictor of adverse behavioral effects observed in fish
L.E. Sweet, J.H. Bisesi, and S.J. Klaine
Institute of Environmental Toxicology, and Department of Biological Sciences
Faculty Mentor: Steve Klaine

ABSTRACT: Widespread use of antidepressants and their incomplete removal during wastewater treatment has resulted in increased detection of antidepressants in many surface waters. Previous research in our lab has elucidated that there is a mechanistic link between antidepressant exposure, brain serotonin levels, and alterations in predation behavior in fish. The objective of the current study was to determine the relationship between the binding affinities of selective serotonin reuptake inhibitor (SSRI) antidepressants to their target receptor, the serotonin reuptake transporter, as a predictor of adverse behavioral responses in fish. The binding affinities (Ki) of fluoxetine, venlafaxine, citalopram, and sertraline were measured using radio-ligand binding assays. Results from this study will provide a valuable tool for predicting the effects of antidepressants on subtle behaviors that directly influence ecological fitness and population survival; but are not captured using traditional toxicity testing endpoints.

Ground Floor #14

Biochemical Characterization of BCCIP β
Leah Watts1, LeAnna Ledford2, and Michael G. Sehorn2
Departments of 2Genetics & Biochemistry, and 1Biological Sciences
Faculty Mentor: Michael G. Sehorn

ABSTRACT: Homologous recombination (HR) is a vital pathway that preserves genomic integrity by repairing double-stranded breaks (DSBs) in DNA. The loss of HR could result in improper chromosome segregation, the formation of tumors or even cell death. Rad51, a RecA-like recombinase, plays a key role in repairing DSBs through HR. Several proteins, such as BRCA2, assist Rad51 during HR. Previous studies have identified a BRCA2- and CKN1A-interacting protein (BCCIP) that is consistently expressed in cancer cell lines with two isoforms, α and β. The goal of this project is to examine the role of human BCCIP β in HR. The BCCIP protein was purified and confirmed by western analysis. Purified BCCIP β was then tested for the ability to bind both single-stranded and double-stranded DNA. Additionally, we investigated the ability of BCCIP β to physically interact with other recombination proteins.

Ground Floor #15

Biochemical Characterization of Xylulose 5-phosphate/Fructose 6-phosphate Phosphoketolase 2 (XFP2) from Cryptococcus neoformans
Katie Glenn, Indrani Bose, Cheryl Ingram-Smith, and Kerry Smith
Department of Genetics & Biochemistry
Faculty Mentor: Dr. Kerry Smith

ABSTRACT: Xylulose 5-phosphate/fructose 6-phosphate phosphoketolase (XFP), which catalyzes the formation of acetyl phosphate from xylulose 5-phosphate or fructose 6-phosphate, was thought to be only present in bacteria but has more recently been found in fungi. Cryptococcus neoformans, an opportunistic pathogen infecting the central nervous system of immunocompromised individuals, has two XFP genes (designated XFP1 and XFP2). XFP2 is upregulated during infection and may be essential for survival, thus XFP2 is a possible drug target in the treatment of cryptococcal infections.

Here we describe the first characterization of a eukaryotic XFP, the C. neoformans XFP2. Optimal pH and temperature for maximum activity are consistent with C. neoformans growth in the human alveolar macrophage. Kinetic parameters were determined for each substrate and show that XFP2 is an allosteric enzyme inhibited by ATP, phosphoenolpyruvate and oxaloacetic acid but activated by AMP. Future studies will determine important residues involved in substrate and allosteric effector binding.

Ground Floor #16

Biofilm Regulation and Control: Studies from Listeria monocytogenes and Vibrio cholerae
Daniel Pederson, Sara Smith, Lauren Blakely1, Yuqing Dong, and Min Cao
Department of Biological Sciences, and 1UC Berkeley School of Law
Faculty Mentor: Min Cao

ABSTRACT: Biofilm is an integral phase of the bacterial life cycle in which the bacterial cells attach to biotic or abiotic surfaces and grow as matrix-encased communities. Biofilm bacteria are highly resistant to sanitizers and are thus difficult to eradicate, posing a big challenge to the public health and the industry. Here, we present our recent progress in biofilm regulation and control from studies of two bacterial systems. On one end, we tried to elucidate the molecular basis of biofilm formation. We applied transposon mutagenesis and genome-wide screening in Listeria monocytogenes, a food-borne pathogen. Biofilm-defective mutants were identified and categorized into four functional groups. On the other end, we have been seeking natural and safe anti-biofilm measures such as nutraceuticals. We found that cranberry extracts could exclusively inhibit biofilm formation of Vibrio cholera, a water-borne pathogen. The inhibition is not due to growth defect, but rather changes of biofilm genes expression.

Ground Floor #17

Biological control of H2S-producing bacteria in raw poultry by-products and surfaces of the rendering plant

Chao Gong1, Spencer Heringa1, Randhir Singh1, Jinkyung Kim2, and Xiuping Jiang1,2
Departments of 1Biological Science, and 2Food, Nutrition & Packaging Sciences
Faculty Mentor: Xiuping Jiang

ABSTRACT: Raw animal by-products destined for rendering process contain high population of H2S producing bacteria (SPB) that can produce harmful H2S and form biofilm. This study was to apply bacteriophages to reduce H2S production and decontaminate SPB biofilm in rendering plant.

SPB-specific bacteriophages were inoculated to raw poultry by-products and SPB biofilm on different surfaces under laboratory and real conditions. SPB was enumerated using TSA-H2S selective medium and H2S production was determined using either PbAc test strips or H2S monitor.

H2S production by SPB in various raw poultry by-products was reduced ranging from 25 to 71% by bacteriophages in laboratory. Phages also reduced H2S production by 30~85% in a greenhouse study. Furthermore, bacteriophages was able to reduce SPB biofilm on different surfaces by 1.5~2 log and 0.4~1.4 log CFU/cm2 in laboratory and rendering plant respectively.

Control of H2S production provides a safer working environment for workers and high quality products for feed industry.

Ground Floor #18

Characterization of GIM5 and PEX11 in Trypanosoma brucei Glycosome Biogenesis
Brett Tomashitis and Meredith Morris
Department of Genetics & Biochemistry
Faculty Mentor: Meredith Morris

ABSTRACT: Trypanosoma brucei is a parasitic protist responsible for African Trypanosomiasis infection. Glycosomes are kinetoplastid-specific organelles which compartmentalize the glycolytic pathway in such parasites, and are thus essential to their fitness. Two specific genes: GIM5 and PEX11, are considered to be involved in glycosomal biogenesis; however, GIM5p and PEX11p are hypothesized to perform the same function: binding to phospholipids via an amphipathic helix during glycosomal membrane constriction and elongation. Microbes are not known to contain redundant genes; therefore, this research seeks to elucidate the roles of two gene products: GIM5 and PEX11, in the de novo biogenesis of the glycosome.

Ground Floor #19

Characterizing the Chronic Toxicity of Total Dissolved Solids on Two Freshwater Invertebrates: Ceriodaphnia dubia and Utterbackia imbecillis
Katherine A. Johnson and Stephen J. Klaine
Institute of Environmental Toxicology
Faculty Mentor: Dr. Stephen Klaine

ABSTRACT: Human activities, such as mining operations and power plant effluents, increase Total Dissolved Solids (TDS) entering freshwater systems. TDS is a measure of all ions present in solution, which contribute to salinity. This increase in salinity causes added stress to freshwater organisms, which use energy to maintain a homeostatic balance of ions between their bloodstream and the environment. However, the contribution of individual ions to this stress is unclear, and although acute toxicities have been well characterized for many ions, the chronic effects are less known. A series of 8-day chronic bioassays to characterize the varying toxicities of chloride, sulfate and bicarbonate on Ceriodaphnia dubia and Utterbackia imbecillis will be performed. Results from this study will facilitate better management of coal-fired power plant effluents, as well as contribute to the growing body of data that suggest C. dubia chronic endpoints are protective of freshwater mussels.

Ground Floor #20

Cloning of Trypanasoma brucei recombinases
Douglas Morte, Shivani Shah and Michael Sehorn
Department Genetics & Biochemistry
Faculty Mentor: Dr. Michael Sehorn

ABSTRACT: Homologous recombination (HR) is a DNA repair pathway that maintains genome integrity. Defective HR results in chromosomal aberrations, improper chromosomal segregation and cell death. The Rad51 and Dmc1 enzymes are critical for successful HR and repair of damaged DNA. The goal of this project is to clone the Rad51 and Dmc1 genes found in the eukaryotic parasite Trypanosoma brucei, synthesize their proteins and biochemically characterize the two recombinase proteins. The genes for these recombinases will be cloned into a bacterial expression plasmid in order to express and purify the proteins. I will use ion exchange chromatography to purify the proteins. These proteins will then be characterized using DNA binding experiments, affinity pull-down experiments, and recombination assays.

Ground Floor #21

Combined Antimicrobial Effect of Sonication and Organic Acid Mixtures on Escherichia coli O157:H7
Xiuping Jiang, Claudia Ionita, Chris Covey, Sharbel Elhage, Matthew Kerr, Parker Leland, Alex Laferriere, Courtney Evans, and Emily Marsinko
Departments of Microbiology, and Food, Nutrition & Packaging Science
Faculty Mentor: Dr. Xiuping Jiang

ABSTRACT: Enteric Escherichia coli infection is a serious problem facing the growers, processers and consumers of fresh vegetables. Antimicrobial methods targeting the pathogenic microorganism are currently employed to treat the vegetables, but what constitutes an effective killing technique often reduces food quality. By combining two or more techniques in less intensive degrees, also known as the hurdle effect, an elevated level of inhibition is achieved while reducing the detrimental effects of the treatment on food product quality.


The particular combination explored was that of high velocity sound waves, generated by a sonicator at various intervals, with low concentrations of lactic acid. Preliminary results indicated that a lactic acid concentration of 0.5% in phosphate-buffer solution combined with a period of sonication exceeding five minutes in length yielded an inhibitory effect greater than either treatment enacted individually. The antimicrobial mechanisms and effectiveness of this combined treatment on fresh produce are currently under investigation.

Ground Floor #22

Comparison of anti-proliferative effects of Noni (M. citrifolia) extract on lung carcinoma TC-1 and fibroblastic CL.7 cell lines
Graham Temples, Ashlee Tietje, and Robert Borucki
Department of Biological Sciences
Faculty Mentor: Yanzhang Wei

ABSTRACT: Morinda citrifolia (Noni) is a chemically rich Polynesian plant that has been utilized in folk medicine for centuries to treat a vast array of ailments ranging from diabetes to cancer. Despite investigations into the properties of Noni, little is known about its compounds effects on mammalian cells. In an effort to better elucidate the cancer combating potential of the plant’s compounds, different concentrations of a uniquely prepared exudate were applied to two cell lines; a “cancerous” lung cell line and “normal” fibroblast line. A comparison of the effects on each model will provide a more practical way to determine the medicinal efficacy of the plant as a novel cancer-fighting agent.

Ground Floor #23

Constitutive expression of a miR156 gene improves turf quality and plant drought tolerance in transgenic creeping bentgrass
Zhigang Li, Dayong, Li, Man Zhou, Qian Hu, Shuangrong Yuan, and Hong Luo
Department of Genetics & Biochemistry
Faculty Mentor: Dr. Hong Luo 

ABSTRACT: MicroRNAs (miRNAs) are small, endogenous RNAs that regulate gene expression in plants and animals. They repress gene expression at the transcriptional or posttranscriptional levels and have critical functions in plant defense, growth, development, disease and stress responses. The miR156 family is one of the first characterized and conserved miRNA families in plants and it has been demonstrated to target SQUAMOSA promoter-binding-like (SPL) genes which encode plant-specific transcription factors. We have cloned a rice miR156 gene (Osa-miR156) and studied its involvement in plant development and plant response to environmental stress. Overexpression of Os-miR156 genes led to dramatic morphological changes in transgenic rice, tobacco and Arabidopsis plants. When overexpressed in turfgrass, transgenic plants exhibited dwarf phenotype and enhanced tolerance to water stress. Our results point out the great potential of microRNA genes for use in genetic improvement of plant architecture, plant biomass production and plant response to environmental adversities.

Ground Floor #24

Cranberry Extract Promotes Longevity and Modulates Stress Response in Caenorhabditis elegans
Sujay Guha, Min Cao, Ryan M. Kane, Anthony M. Savino, Sige Zou, and Yuqing Dong
Department of Biological Sciences 
Faculty Mentor: Yuqing Dong

ABSTRACT: Nutraceuticals are known to have numerous health benefits. Here we examined the effects of cranberry extract (CBE) on the lifespan of Caenorhabditis elegans, a nematode used extensively in aging research. Supplementation of CBE increased the lifespan of worms in a dose-dependent manner. Because aging and stress are correlated, we also tested the effects of CBE supplementation on numerous stresses. We found that CBE supplementation improved the survival of worms under heat shock. In addition, we tested the effects of CBE on general health parameters and found that CBE did not influence these factors. Next, we wanted to examine the pathways that might play a key role in bringing about this lifespan extension. Further experimentation indicates that cranberry supplementation confers increased longevity and stress resistance in C. elegans through pathways modulated by daf-16 and osr-1. This study elucidates the anti-aging properties of cranberries and their modes of action.

Ground Floor #25

Determination of EPSPS copy number in Amaranthus species
Katerina Lay and Kristin Beard
Department of Genetics & Biochemistry 
Faculty Mentor: Amy Lawton-Rauh

ABSTRACT: Amaranthus is a diverse genus plants, the most notable of which, A. palmeri, is considered a weed by farmers. Previous studies by Gaines et al. (2009) have shown that increased copy number in the gene coding for 5-enolpyruvylshikimate-3 phosphate synthase (EPSPS) has been linked to glyphosate (the major component in the herbicide Round-up) resistance in A. palmeri. This experiment investigates the copy number of EPSPS in various species of Amaranth, including A. palmeri, in order to see if high EPSPS copy number is a standing variation among members of the genus, or if it occurs from a novel mutation when the plant is under the selective pressure of glyphosate. Quantitaive PCR was carried out on genomic DNA of 10 different species of Amaranthus to determine the relative copy number of EPSPS in those plants.

Ground Floor #26

Development of a RacF2DN-RFP Expression Vector for Rab8 Colocalization Studies in the Social Amoebae, Dictyostelium discoideum
Joseph Angeloni1, Brittany Lamont2, Amanda Goldston1, Rhonda Powell1, Lesly Temesvari1, and Terri Bruce1
Departments of 1Biological Sciences, and 2Public Health Sciences
Faculty Mentor: Terri F. Bruce

ABSTRACT: The small GTPase, Rab8, has been implicated in cellular adhesion events and actin cytoskeleton restructuring in mammalian cells and in the lower eukaryote, Dictyostelium discoideum. D. discoideum is a non-pathogenic amoeba whose life cycle consists of both single-cell and multi-cellular stages. When constitutively activated Rab8 (Rab8CA) was expressed in D. discoideum, it caused changes in cell morphology including a reduction in the cell adhesion molecule, gp24, and development of actin-rich protrusions. Although Rab8 has been shown to effect actin restructuring, no specific pathway for this action has been identified. It is believed that the protein RacF2 may lie upstream of Rab8 in the actin pathway. The goal of this work was to provide further evidence for the interaction between Rab8 and RacF2 by determining if the two proteins colocalize within the cell. A new RacF2-DN-RFP plasmid was constructed and subcellular localization of RacF2-DN-RFP and Rab8-CA-GFP
was examined using fluorescence microscopy.

Ground Floor #27

Development of Molecular Beacons for Detection of African Trypanosome Infections
Haaris S. Khan, Lauren M. Frederic, Kenneth A. Christensen, and James C. Morris
Department of Genetics & Biochemistry
Faculty Mentor: Dr. James C. Morris

ABSTRACT: Trypanosoma brucei is the causative agent of African sleeping sickness, a neglected tropical disease endemic to sub-Saharan Africa. As the name suggests, neglected tropical diseases have been historically overlooked by the majority of researchers, often due to a perceived lack of incentives. The first step towards treatment is an accurate diagnosis. Currently, only trained technicians working in a clinical laboratory can diagnose these diseases, a privilege to which most at risk communities have no access. The goal of this project was to develop a new method for the detection of African sleeping sickness with the use of a diagnostic device that is inexpensive, easy to use, field ready, and has results that can be seen by eye. At the heart of the device are fibers that, after treatment, are able to bind parasitic DNA through complementary base pairing and can therefore determine the presence of the parasite in a sample.

Ground Floor #28

Effects of Fescue Toxicosis on Bovine Semen Quality
Heather M. Stowe1, Maggie C. Miller1, Matthew G. Burns1, Samantha M. Calcatera1, John G. Andrae1, Glenn Aiken2, F. Neil Schrick3, William C. Bridges4, and Scott L. Pratt1
Departments of 1Animal & Veterinary Sciences (Clemson Univ.), 2USDA-ARS (Univ. Kentucky), 3Department of Animal Science (Univ. of Tennessee), 4Department of Mathematical Sciences (Clemson Univ.)
Faculty Mentor: Scott L. Pratt

ABSTRACT: Tall fescue, a popular forage in the Southeast due to its heat, drought, and pest resistance, has a symbiotic relationship with a fungal endophyte, which produces compounds that are toxic in animals consuming the grass. Our objective was to determine the effects of fescue toxicosis on bovine semen quality. Bulls were assigned to treatments of toxic (E+) or non-toxic (E-) fescue seed for 126 days. Semen and blood samples were collected every 21 days for analysis. Decreased PRL levels demonstrated the effectiveness of the E+ diet on bulls, while reduction in SC for E+ treated bulls towards the end of the study may be due to restricted blood flow to the testes. Fescue toxicity had little to no effect on semen quality in this experiment. Future studies should expand beyond normal semen analysis and address possible biochemical changes in spermatozoa that would impact male fertility.

Ground #29

Characterizing the Bioavailability of Fluoranthene Adsorbed to Carbon Nanotubes in the Presence of Natural Organic Matter
E.N.Linard, P. van den Hurk, and S.J. Klaine
Institute of Environmental Toxicology
Faculty Mentors: P. van den Hurk, and S.J. Klaine

ABSTRACT:  The introduction of carbon nanomaterials into the environment has increased exponentially in the last decade. Of particular concern is the interaction that such nanomaterials have with the biota in the aquatic ecosystem and the direct and indirect toxic effects that may result.  Previous research has documented positive influence of natural organic matter (NOM) on the stability of carbon nanotube (CNTs) suspensions in surface waters.  Further, other research has quantified the ability of these nanomaterials to adsorb aquatic contaminants such as polynuclear aromatic hydrocarbons (PAHs).  Although CNTs and PAHs can co-occur in wastewater treatment effluents no research has characterized the bioavailability of these adsorbed PAHs.  The goal of this research was to characterize the bioavailability of fluoranthene that has been adsorbed to CNTs to fathead minnows. The fathead minnows will be exposed for 15 hrs to different treatments including fluoranthene alone, fluoranthene in the presence of different concentrations of NOM, and fluoranthene adsorbed to CNTs in the presence of NOM.  Bioavailable fluoranthene is quantified in each exposure through bile analysis using a fluorescence microplate reader.

Ground #30

Modeling Studies of Soy/Polyethylene Composite Fibers to Determine Microbiological Stability and to Develop a Prediction Model for Mold Spoilage
Chinmay Naphade1, Inyee Han1, James Rieck2, Amod Ogale3 and Paul Dawson1

Departments of 1Food, Nutrition and Packaging Sciences, 2Department of Mathematical Sciences, 3Department of Chemical and Biomolecular Engineering
Faculty Mentor: Paul Dawson

ABSTRACT: The objective of present study was to determine the microbial stability of Soy/Polyethylene (soy/PE) composite fibers against environmental yeast and mold growth. A detailed study was performed to predict the safe storage period of soy/PE fibers under various temperature (T) and humidity conditions by moisture sorption. Understanding of environmental effects on mold growth is important for safe processing manufacturing, storage and use of soy/PE biocomposite. Statistical models would be valuable to predict mold free days (MFD) under controlled storage conditions and could be used to determine appropriate storage conditions and use conditions for bio-composites. Mold spoilage was visually monitored for 109 days on soy/PE fibers maintained under controlled temperatures (T) and water activities (aw). Container with saturated salt solutions generating water activities ranging from 0.11 to 0.98 were placed in temperature-controlled incubators with temperatures ranging from 10oC to 40oC. Soy/PE fibers that were held at 0.823 water activity (aw) or higher exhibited mold growth at all temperatures. As postulated, increased aw (greater than 0.89) and temperature (higher than 25oC) accelerated mold growth on soy/PE fibers. A slower mold growth was observed on soy/PE fibers that were held at 0.87 aw and 10oC. A Weibull model was employed to fit the observed logarithmic values of T, aw and an interaction term Log T × Log aw and was chosen as the final model as it gave the best fit to the raw mold growth data. These growth models predict the expected mold-free storage period of soy/PE fibers when exposed to various environmental temperatures and humidities.

Ground # 31

Chitosan and Modified Atmosphere Packaging to Prevent Oxidation in Whole Milk
Wesam Hameed Barrak Al-Jeddawi and Paul Dawson
Department Food, Nutrition and Packaging Sciences
Faculty Mentor: Paul Dawson

ABSTRACT:  Milk powder product is widely used in many food products therefore the demad has increased for a high quality product.  People get the benefit of dried milk powder as an ingredient in many foods such as infant formula, chocolate or coffee whitners.  One problem is after drying, the powders are more vulnerable to lipid oxidation.  The main goal is studying the antioxidant effect of Chitosan which will be combined with modified atmosphere packaging (MAP) in order to prevent oxidation in the while mild powder.  Chitosan is a linear polysaccharide with a good biodegradability, biocompatibility, and no toxicity, which allows for its potential use as a preservative.  The chitosan molecule appears to be a suitable polymeric complex for many biomedical applications.  Chitosan has antioxidant properties, including scavenging activities for DPPH radicals, hydrogen peroxide, superoxide anion radicals and CU2 ino-chelating activity.  In addition, packaging of dried milk powder is important to retard the oxidation; therefore, increasing attention has focused on midified atmosphere packaging.  Packaging proposed in this research is 60% nitrogen with 40% carbon dioxide in order to retard oxidation.  Thus, the combination of different concentrations of chitosan and modified atmosphere packaging will be tested to prevent oxidation in while milk powder.  The treatments will be (Chitosan 2% combined MAP 20% CO2+80% O2), (Chitosan 3% combined MAP 20% CO2+80% O2), (Chitosan 4% combined MAP 20% CO2+80% O2), (Chitosan 8% combined MSP 20% CO2_80% O2). Then, all samples will be stored at 45 centigrade for 50 days. Each 10 days, the samples will be tested by using two-thiobarbiturid acid (TBA test) and DPPH radical free assay in order to examine the anitoxidative effect of chitosan and combination of chitosan with Modified atmosphere packaging in the whole milk powder. 

Ground #32

Bactericidal Effects of Natural Tenderizing Enzymes on Escherichia coli and Listeria monocytogenes
Hanan Eshamah1, Inyee Han1, Hesham Naas2, James Rieck3 and Paul Dawson 1,4    
Departments of 1Food, Nutrition and Packaging Sciences, 2Department of Food Hygiene, Faculty of Veterinary Medicine (Univ. of Tripoli, Tripoli, Libya), and 3Department of Mathematical Sciences
Faculty Mentor: Paul Dawson

ABSTRACT: The main objective of this study was to determine the antimicrobial activity of proteolytic enzymes (papain and bromelain), which used as meat tenderizer, against E. coli and L. monocytogenes at three different temperatures (5, 25 and 35°C). Two overnight cultures of E. coli Jm109 and L. monocytogenes were separately suspended in 1% peptone water and exposed to the proteolytic enzyme (papain and bromelain) at three different temperatures. Bromelain concentrations (4mg/ml) and (1mg/ml) that tested at room temperature against E.coli and L.monocytogenes respectively were the most effective concentrations. It reduced the mean for log of CFU/ml by 3.37 and 5.7 after 48h respectively.

Papain concentrations (0.0625 mg/ml) and (0.5 mg/ml) that tested at room temperature against E. coli and L. monocytogenes respectively were the most effective concentrations. It reduced the mean for log of CFU/ml by 4.94 and 6.58 after 48h respectively.   It was noticed that the small papain concentration (0.0625 mg/ml) was more effective than the large concentration (0.5mg/ml) against E. coli at all three temperatures. Also the temperature had an effect on enzymes (bromelain, papain) efficiency against both E. coli and L. monocytogenes. This experiment showed that the higher the temperature (35°C) the more effective the enzymes.

Ground # 35

Efficacy of Combining Ginger Extract, Tea Extract with Nisin to Increase Meat Safety during Storage
Yueyuan Zhang and Paul Dawson
Department Food, Nutrition and Packaging Sciences
Faculty Mentor: Paul Dawson

ABSTRACT: There have been a lot of reports on antibacterial effect of ginger extract and tea extract. Studys have shown that tea extract have great inhibition effect on many bacteria such as Listeria monocytogenes and E. coli. Ginger extract also possess good antibacterial effect on bacteria such as Staphylococcus aureus and Streptococcus pyogenes. Besides, nisin is one of the most commonly used natural antimicrobial compounds which are regarded as safe additive. However, the antibacterial effect is not good as expected. Combing all of these natural preserves maybe an effective way to control foodborne pathogens thus increasing meat safety.

Ground #36

Application of Papain and Bromelain for Meat Products Tenderization
Ahmet Buyukyavuz and Paul Dawson
Department Food, Nutrition and Packaging Sciences
Faculty Mentor: Paul Dawson

ABSTRACT: This study investigates the tenderizing effects of the commercially used tenderizers (papain and bromelain) in muscle foods. Uniform-sized parts of meat will be marinated with different concentrations of papain and bromelain for a specific time at a specific temperature. Concentrations for each enzyme will be determined during early investigations to maximize tenderizing effects while minimizing negative effects on eating quality. The samples marinated with different enzyme solutions will be exposed to texture measurement, sensory evaluations, biochemical analysis and histological observations after stored by taking account time and temperature. Hence, changes in pH, moisture content, water holding capacity, shear force values, collagen solubility, sarcoplasmic and myofibrillar protein solubility, flavor, juiciness of marinated meat will be observed. Moreover, the extent of tenderization and myofibrillar or/and collagen degradation will be determined.