Abstracts Year: 2017
Avolio, Theodore: Creating the fbiA-fbiB- Double Null Mutant in Dictyostelium discoideum
Favaro, Daniel: Genetic Pathway Analysis of Adolescent Idiopathic Scoliosis
Lattin, Chloe: Influence of Polyamines on Haemophilus ducreyi Growth
Maar, Megan: Molecular investigation of the Northern Brine Milkvetch, Astralagus pychnostachyus var. pychnostachyus, as a conservation model for the Ventura Marsh Milkvetch, Astragalus pychnostachyus var. lanosissimus
Thiessen, Jessie: Estrogen Fluctuations in the Female Menstrual Cycle
Sexual Behavior of Male Guppies (Poecilia reticulata) in Response to the Glyphosate-based Herbicide RoundupDate: Spring 2017
Thesis Committee: Dr. Ron Mumme and Dr. Catharina Coenen
Abstract: The use of glyphosate-based herbicides, such as Roundup, in the agricultural industry has increased dramatically since their development in the 1970s. One consequence of this usage is contamination of freshwater environments. Through excess usage, these agrochemicals run-off into external environments not intended to be exposed to the herbicide. As herbicide use persists, aquatic environments and their inhabitants will continue to be exposed to these new external stresses. The freshwater guppy species Poecilia reticulata is a common model organism used to study sexual selection and female preference for male coloration. Sexual behavior is also widely studied in regards to male guppies due to their persistent and visual courtship behavior. Based on the increased use of herbicides in agriculture, I examined the effect of the glyphosate-based herbicide, Roundup, on the sexual behavior in male guppies. I predicted that courtship behavior and mating attempts of male guppies would decrease in response to Roundup exposure. Male guppies were exposed to Roundup concentrations of 100 μg/L and 700 μg/L for an 8-10 day period. Concluding this period, each number of approaches to female’s and sigmoid displays were observed and recorded for each male, for a duration of 10 minutes. It was observed that after this exposure, male guppies exposed to a higher concentration of Roundup (700 μg/L) courted females more vigorously than did males in the control group. The results suggest that Roundup may actually have endocrine disrupting effects at very low concentrations, and that further work is needed to clarify these effects.
An Analysis of Genetic Diversity in the Pennsylvania State Population of White-Tailed Deer (Odocoileus virginianus) 110 Years After Bottleneck and TranslocationDate: Spring 2017
Thesis Committee: Dr. Kristen Webb and Dr. Matthew Venesky
Abstract: In wildlife conservation, genetic rescue is an attempt to combat the negative genetic effects of population bottleneck by increasing genetic diversity through translocation of new individuals into a threatened population. This method has been used extensively to preserve genetic diversity in overhunted populations, but concerns exist over the long-term consequences of these conservation efforts. White-tailed deer (Odocoileus virginianus) in the United States suggest long-term translocation success, with present population density at its highest point since European settlement and genetic diversity comparable to deer herds untouched by European hunting. Deer in Pennsylvania represent one of the oldest examples of these translocations, supporting the method as a viable means of genetic rescue. However, no current studies have analyzed the genetic diversity of this population. We used microsatellite analysis to assess genetic diversity at two loci across a sample of Pennsylvania white-tailed deer collected from hunters, testing our results for genetic bottleneck and comparing them to other recovered white-tailed deer populations. Our results suggest that Pennsylvania deer exhibit no evidence of genetic bottleneck and a level of genetic diversity comparable to recovered deer populations, supporting translocation as a sustainable means to maintain genetic diversity when increasing the size of a threatened population.
Probiotic Interference and Fibronectin Binding in Haemophilus ducreyi without dsrADate: Spring 2017
Thesis Committee: Dr. Tricia Humphreys and Dr. Catharina Coenen
Abstract: Chancroid is a sexually transmitted genital ulcerative infection commonly found in developing countries. The infection is caused by Haemophilus ducreyi, a gram-negative bacterium with outer membrane proteins that allow the pathogen to move through breaks in the epithelial lining of the genitals and adhere to the dermis. One of the major outer membrane proteins responsible for adhesion is Ducreyi serum resistance A (DsrA), which binds to fibronectin in the extracellular matrix. The current treatments for chancroid infections are antibiotics. However, due to the high cost and minimal availability, probiotic therapy is being considered as an alternative treatment. Three interference assays: competition, displacement, and blockage by exclusion were utilized to see how adherence was affected by Lactobacillus. I predicted that the dsrA mutant would not bind to the lysine or fibronectin coated plates as well as the wild type. My hypothesis was not supported. Both the interference and noninterference binding assays showed no significant difference between mutant and parent binding. The ANOVA showed a significant difference among the probiotic assays. The blockage by exclusion and competition assays were significantly different from each other. I predicted that the blockage by exclusion assay would greatly reduce adherence and my hypothesis was supported. I suspected that a mix of the two Lactobacillus strains would inhibit adhesion more than the individual strains. The ANOVA showed no significant difference among these treatments types. In conclusion, no significant difference was found among the pathogens, or among the Lactobacillus treatment types. However, timing of probiotic interference does significantly affect pathogen adherence.
Interactions Between Haemophilus ducreyi and Bacteria Found in the Male Urogenital Normal FloraDate: Spring 2017
Thesis Committee: Dr. Tricia Humphreys and Dr. Scott Wissinger
Abstract: Haemophilis ducreyi, the bacterium that causes the sexually transmitted disease chancroid, causes ulcer formation on men more frequently than on women. This sex bias could potentially be caused by a difference in the normal flora found on men and women. This study tested the interactions between components of the male urogenital normal flora, Mycobacterium smegmatis and Corynebacterium glucuronolyticum, with Haemophilus ducreyi. I hypothesized that the male normal flora species would increase the growth of H. ducreyi. Additionally, I expected that, as opposed to testing each bacterium with H. ducreyi individually, a combination of both C. glucuronolyticum and M. smegmatis would have the largest additive effect on the growth of H. ducreyi. By making mixed co-cultures of the three organisms, spreading these cultures on agar, and counting the bacterial colonies after incubation, I was able to determine that interactions between the organisms did not support the hypothesis. The data showed that H. ducreyi had a small increase of growth when co-cultured with M. smegmatis. However, H. ducreyi did not grow when co-cultured solely with C. glucuronolyticum. In the mixed culture with all three organisms, the C. glucuronolyticum inhibited the H. ducreyi enough to show a decrease in growth. An unexpected increase of C. glucuronolyticum growth was found in all cultures in which C. glucuronolyticum was present with H. ducreyi. In undeveloped countries, in which chancroid is most commonly found, I suspect that chancroid is misdiagnosed and the symptoms could be mistaken for an overgrowth of C. glucuronolyticum. These results support the idea that the normal flora in the male urogenital system could be a factor in the sex bias of male chancroid diagnoses.
Creating the fbiA-fbiB- Double Null Mutant in Dictyostelium discoideumDate: Spring 2017
Thesis Committee: Dr. Margaret Nelson and Dr. Kristen Webb
Abstract: Dictyostelium discoideum is a soil-dwelling social slime mold that serves as a remarkably useful model organism for studying signal transduction pathways, cell-type proportioning, and the ubiquitin-proteasome system (UPS). In the UPS, proteins are marked for ubiquitin-mediated degradation; therefore, it is a powerful regulatory pathway. FbxA is a protein that has been identified as a part of an SCF ubiquitin-ligase complex. FbxA likely targets another protein known as FbiA for ubiquitin-mediated proteolysis. In fbiA- null mutants, the developing organisms exhibit small prespore cell populations and increased prestalk populations. Thus, FbiA likely promotes the prespore pathway while inhibiting the prestalk pathway. A protein homologous to FbiA has been identified via sequence analysis, and it is suitably called FbiB. Mutants of the fbiB- null variety show a less severe phenotype relative to fbiA- nulls; however, they are comparable. Because of this less severe phenotype, it is suspected that the two proteins “rescue”, consequently demonstrating functional redundancy. Therefore, it is of interest to create an fbiA-fbiB- double null mutant in order to study this relationship. This study took steps toward confirming existing pools of double mutant candidates; however, no conclusive evidence emerged from various PCR analyses to verify genuine double mutants in those pools. As a result, a fresh attempt at creating the fbiA-fbiB- double knockout was commenced, which began by transforming Blasticidin sensitive fbiB- single null mutants. A PCR analysis of newly created double knockout candidates proved to be extraordinarily promising.
The Effects of Omega-3 Fatty Acid and Exercise on Olfaction and Memory on Alzheimer’s Disease In MiceDate: Spring 2017
Thesis Committee: Dr. Lee Coates and Dr. Ann Kleinschmidt
Abstract: Alzheimer’s disease (AD) is categorized as type of dementia that is recognized post-mortem by neurofibrillary tangles and beta-amyloid plaque build-up in areas of the brain associated with memory. The main symptoms include: confusion, mood swings, and short-term memory deficits; the incidence rate of AD is predicted more than double by 2050. Prior research has found omega-3 fatty acid and regular exercise slow the progression of AD. I hypothesized that the combination of omega-3 supplementation and exercise would prevent olfactory and memory decline associated with AD more than one of the treatments alone. My study included twenty-four Alzheimer’s model mice broken down into four groups. The Control group was given no treatment and the three experimental groups were given: exercise only, supplemented omega-3 fatty acid rich diet only, and both exercise and omega-3 supplementation. Groups that received exercise treatment ran on a treadmill three days a week at 13 meters/minute for twenty minutes. The groups that received omega-3 fatty acid were given food composed of 2.83% omega-3 fatty acid, as opposed to 0.30% in the normal food. The progression of Alzheimer’s was measured before and after treatment through a y- maze test, which measured spatial working memory and a hidden cookie test, which measured olfaction. A paired t-test did find a significant increase in time it took the mice in the Control group to find the hidden cookie after the treatment and a significant decrease in the time the omega-3 mice spent in the novel arm of the y-maze after treatment. This study found no significant difference between treatments, but a general trend showed the experimental groups performed better than the Control group. It appears that any of the experimental treatments are equally beneficial for AD patients compared to no treatment.
Effects of Pseudomonas fluorescens-produced antibiotic 2,4-Diacetylphloroglucinol on Chestnut Blight fungus Cryphonectria parasiticaDate: Spring 2017
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Catharina Coenen and Dr. Casey Bradshaw-Wilson
Abstract: Before the 1900s, the American chestnut tree, Castanea dentata, was a major component in the United States’ eastern deciduous and hardwood forests. It was a keystone species that many species of animals as well as humans depended on. When the chestnut blight, a fungus called Cryphonectria parasitica, was introduced from China, virtually all American chestnut trees were wiped out. Roots continue to survive in the soil and send up sprouts, but these sprouts do not survive to maturity. Attempts to bring back the chestnut tree have been largely unsuccessful. The purpose of this study was to determine if the root-associated bacteria Pseudomonas fluorescens and the antibiotic it produces, 2,4-diacetylphloroglucinol (DAPG), could be used as an effective treatment against C. parasitica. Chestnut trees were treated with a P. fluorescens inoculum, which was applied directly to cankers. Change in canker size was measured before and after treatment. Antibiosis experiments were performed with P. fluorescens and the P. fluorescens mutant lacking the phlD gene and plugs of C. parasitica in order to see if zones of inhibition were produced. Well diffusion assays were performed with DAPG and C. parasitica to also observe any zones of inhibitions. All treatments were found to be ineffective. Although this method was unsuccessful in treating chestnut blight, it is still important to find a way to restore the American chestnut tree.
Temporal and interspecific variation of the amphibian chytrid fungus Batrachochytrium dendrobatidis in northwest PennsylvaniaDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Casey Bradshaw-Wilson
Abstract: The abundance of parasites varies through time and among species, and is often associated with environmental factors (e.g. temperature) and host life-history traits (e.g. developmental rate). The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is one of the primary drivers of amphibian population declines and extinctions around the world. Like many parasites, Bd has temperature-dependent growth and amphibian species vary in their resistance to Bd, both of which could affect Bd prevalence in populations. To understand seasonal Bd dynamics in populations of amphibians, I conducted field surveys throughout the fall in northwest Pennsylvania. I tested for temperature-driven temporal patterns of Bd prevalence and infection intensity in green frog (Lithobates clamitans) and bullfrog (Lithobates catesbeianus) tadpoles at 2 ponds from September 23 – November 27 2016. I also recorded body length of each tadpole to assess for variation in Bd infection throughout tadpole development. Water temperature was a significant negative predictor of Bd infection prevalence in bullfrogs and a marginally significant negative predictor of Bd infection prevalence in green frogs. Length was a significant positive predictor of Bd infection prevalence and intensity in bullfrogs but not in green frogs. These results emphasize the importance of considering species identity and developmental stage when surveying for Bd and suggest that like in other regions, temperature is a driver of Bd prevalence fluctuations in northwest PA.
Vertebrate hormones in insects: Effects of Beta-Estradiol on mating, pre-oviposition time, fecundity, and fertility in the female ring-legged earwig, Euborellia annulipesDate: Spring 2017
Thesis Committee: Dr. Susan Rankin and Dr. Margaret Nelson
Abstract: Although Beta-Estradiol (estradiol) is a naturally occurring sex hormone in vertebrates, its physiological role in invertebrates remains unknown, despite its presence in multiple invertebrate species. While estradiol may or may not be naturally synthesized in invertebrates, it alters reproductive structure and function ranging from vitellogenin production and oocyte maturation to larval growth and development (Li et al 1997; Keshan and Ray 1999). The female ring-legged earwig, Euborellia annulipes, was used as a model system for observing the potential effects of estradiol in insects. Estradiol was topically applied to adult female earwigs, in either a low dose of 0.05 µg or a high dose of 0.5 µg, on day 0 and again after mating on day 7. Mating times and behavior, pre-oviposition time, number of eggs, and number of hatchlings were examined. In addition, estradiol levels in the adult females were quantified via an ELISA following termination 15 days post-oviposition. Treatment with estradiol did not induce changes in mating behavior, pre-oviposition time, number of eggs, or number of hatchlings, but did alter maternal behavior, such as inducing maternal cannibalism. All groups of females had detectable levels of estradiol, including the untreated control females, suggesting that female E. annulipes naturally synthesize estradiol. The presence of estradiol indicates the existence of some metabolic pathway in female E. annulipes to regulate and utilize the hormone, supporting the notion that at least some steps of steroid synthesis are conserved in invertebrates and vertebrates.
Effects of Detritivores on Detritus Breakdown in Wetlands: Do Detritivores Matter?Date: Spring 2017
Thesis Committee: Dr. Scott Wissinger and Prof. Christopher Lundberg
Abstract: Detritus decomposition is an important contributor to the productivity of wetlands; however, there is controversy over the role of animal detritivores in this process. Previous studies have demonstrated that detritivores (caddisflies, stoneflies, etc.) accelerate the breakdown of detritus with leaves in streams, but few studies have quantified the relative roles of animal detritivores and microbial decomposers in standing water habitats. The goal of this study was to determine the in situ role of animal detritivores, including caddisflies and other “cryptic” detritivores, on the breakdown of sedge (Carex) and red maple (Acer rubrum) leaves in a small, isolated wetland. This experiment assessed the relationship between detritivores and detritus decomposition rates by comparing detritus breakdown in litter packs that included or excluded detritivores. I hypothesized that (1) the presence of detritivores would result in a greater detrital decomposition rate when compared to the trays excluding detritivores, and (2) the relative decomposition rates of detritus composed of red maple leaf would be greater than sedge detritus. I found that red maple leaves decayed faster in comparison to sedge, but that after the first four months of experimentation, that detritivores had no effect on the decomposition of either types of detritus.
Effects of the black spot disease parasite, Uvulifer amblopliti, on the behavior of blacknose daceDate: Spring 2017
Thesis Committee: Dr. Scott Wissinger and Dr. Casey Bradshaw-Wilson
Abstract: Parasites are extremely common in fish populations and affect the health and behavior of their host. Many parasites do not kill their hosts, but rather utilize host energy resources, which indirectly can change normal behaviors of their host. The purpose of this study is to examine how the parasite Uvulifer amblopliti, commonly called Black Spot Disease (BSD) affects the foraging behaviors of blacknose dace (Rhinichthys atratulus) in the French Creek Watershed Area in Northwestern, Pennsylvania. I hypothesized that with an increase in parasite load, there would be a decrease in ability to capture prey. I studied the behavior of fish with different loads of BSD infection. With an increase in parasite load, I speculated there to be an increase in feeding rates within the individuals, possibly due to the amount of energy that is needed to host the parasites without causing harm to itself. I found that with an increase in parasite load, prey consumption success rates decreased. I concluded that this parasite can reduce its host’s ability to capture food effectively while also requiring a greater intake of protein. Some future studies of this topic would include observations of other behaviors such as competition success between parasite load categories and swimming performance.
Carver , KayLynn
The Benefit of Resveratrol and Quercetin Co-treatments in Canine OsteosarcomaDate: Spring 2017
Thesis Committee: Dr. Ann Kleinschmidt and Dr. Tricia Humphreys
Abstract: Phytochemicals from grapes and berries, including resveratrol and uercetin, have been studied for their chemotherapeutic properties. Quercetin and resveratrol, used individually, have caused decreases in proliferation of various cancer cell lines ranging from breast cancer to human steosarcoma. Co-treatments of resveratrol and quercetin have led to a synergistic, more
than additive, decreases in cell proliferation through apoptotic pathways, synergism which lead to a more efficient cancer cell decrease than if the chemicals were merely additive. In this study it was of interest to determine whether resveratrol and quercetin, alone or in combination, would have anticancer effect on OSCA-40, an osteosarcoma cell line. Cells were treated with resveratrol and quercetin independently and in combination, a decrease in proliferation was observed. To determine if the proliferation decrease occurred due to apoptosis, the treated cell were stained using DRAQ 5, a DNA stain, and analyzed using an imaging flow cytometer. The
analysis concluded that the co-treatment of resveratrol and quercetin lead to a significant increase in cells with a sub G1 level of DNA, signifying apoptosis. The data supports that resveratrol and quercetin in combination are able to induce apoptosis of OSCA-40 cells.
Differentiation of Cat Littermates by Means of Mitochondrial Control Region SequencingDate: Spring 2017
Thesis Committee: Dr. Kirsten Webb and Dr. Ann Kleinschmidt
Abstract: In animal forensics, animal identification is crucial, especially in criminal cases where animal hair can be used as evidence through means of mitochondrial DNA testing. However, a limiting factor to using mitochondrial DNA is being unable to differentiate between animal littermates because they inherit identical mitochondrial genomes from their mothers. This study is based on a human identical twins study where single nucleotide polymorphisms were discovered in between the mitochondrial genomes of 43-58 years old identical twins. The purpose of this study is to search for mitochondrial DNA differences between cat littermates. The control region of the cat mitochondrial genome was amplified and sequenced in cat littermates ranging in age from 6 months to 13 years old. Out of 11 littermate pairs, one has a single nucleotide polymorphism due to heteroplasmy. The pair was 5 years and 7 months old being equivalent to 36-40 human years old which is close to the ages of the human identical twins containing SNPs. It is possible that mitochondrial differences can occur during an individual’s lifetime, and first be detected when they are middle-aged; however, more research needs to be done. Nevertheless, this study stresses the necessity for using mitochondrial DNA testing as a method for distinguishing between the mitochondrial DNA profiles of maternally related individuals.
Are Anxiety and Depression in Offspring Caused by an Induced Immune- Response in Mothers During Pregnancy?Date: Spring 2017
Thesis Committee: Dr. Ron Mumme and Dr. Lisa Whitenack
Abstract: Influenza infections cause thousands of fatalities per year around the world. The offspring of mothers who contract the virus during pregnancy may be at a higher risk of developing psychological disorders due to the mothers’ immune-response causing detrimental effects to their fetus. Psychological disorders such as anxiety and depression are commonly diagnosed disorders. Using C57 mice as a model system, (1) I induced a flu-like immune- response in pregnant females using a flu-like immunostimulant , polyinosinic-polycytidylic acid (poly IC), and observed the offspring in an open-field test for depressive and anxious-like symptoms using four indicators of anxiety and/or depression: locomotion and exploratory behavior, defecation, urination, and sucrose anhedonia. I then, (2) re-tested for depressive and/or anxious-like symptoms by performing an identical open-field test with the same individuals after treatment with the anxiolytic drug benzodiazepine alprazolam, which is often used to reduce severity of psychological symptoms. Results suggest that poly IC injection in pregnant females significantly increased locomotion and exploratory activity (number of grid lines crossed) and significantly reduced sucrose consumed in their pups. There were no significant effects of poly IC injection on fecal pellet count and urination. Alprazolam treatment had no significant effect on any of the behavioral traits. Further research should be conducted to explore and expand upon the detrimental effects that maternal immune-responses may cause during pregnancy and what behavioral changes may occur in offspring. It is also important to explore what drugs may be beneficial in treatment of offspring of immune-challenged mothers.
The Effect of Aquatic Surface Area on Frog Resistance to a Fungal PathogenDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Susan Rankin
Abstract: Climate change is an ongoing issue around the world over the past two decades, especially in regards to how it changes the habitats of wildlife. For aquatic environments, this climate and resulting habitat change could be detrimental and poses as a potential stressor that decreases an organism’s ability to resist disease. As global temperature rises, aquatic environments get smaller. Smaller surface area of such environments decreases dissolved oxygen content, causing breathing rate to increase and thus could be a potential stressor. This study investigates how variance in surface area size affects the resitance of African Clawed frogs’ (Xenopus laevis) to the fungal pathogen Batrachochytrium dendrobatidis (Bd). Frogs were randomly distributed to aquatic environments that had either a small, intermediate, or large surface area with the same depth and volume. After 14 days, frogs were put into individual containers and exposed to Bd. Thirteen days after exposure, I swabbed the skin of each frog and used qPCR analysis to determine the infection intensity (genomic DNA equivalents of Bd). Mass was also taken prior to and after infection. Only 7 of the 24 frogs exposed to Bd were infected upon completion of the experiment and 22 of the 24 frogs experienced a decrease in mass. Surface area size was not a significant predictor of Bd infection intensity. This study suggests that, against my original hypothesis, surface area size does not increase X. laevis frogs’ susceptibility to Bd but a larger change in surface area or a more immediate introduction of the pathogen may increase disease intensity. This implies that this specific change in aquatic environment shape does not decrease frogs’ ability to resist Bd.
"Changes in Lactobacilli Probiotic Concentration After Exposure to Haemophilus ducreyi and Unknown Contaminants **(Haemophilus ducreyi needs to be italicized)**"Date: Spring 2017
Thesis Committee: Dr. Tricia Humphreys and Dr. Lisa Whitenack
Abstract: Chancroid is a sexually transmitted infection caused by Haemophilus ducreyi, which forms ulcers on and around the genitals. Because chancroid raises an individual’s risk of contracting human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs), it is imperative to find an affordable and effective treatment. Since probiotic therapy with lactobacilli has been shown to be successful in alleviating symptoms in bacterial vaginosis infections, it could be useful against H. ducreyi. If in vitro experimentation is successful, human in vivo models would be the ultimate target. In order to simulate the daily amount of vaginal secretions produced by an infected female, H. ducreyi was added to a solution of Brain Heart infusion broth containing lactobacilli. It was hypothesized that the planktonic H. ducreyi would survive when placed into the original lactobacilli solution, but the surviving planktonic bacteria would die when subjected to the lactobacilli probiotic therapy treatment. Due to continuous contamination, however, H. ducreyi was unable to grow neither independently nor when combined with lactobacilli, preventing the testing of probiotic therapy. This resulted in the collection of lactobacilli colony forming units (CFUs) instead of the surviving H. ducreyi CFUs. Lactobacilli did not show significant decreased growth when exposed to a pathogen. Nonetheless, due to the presence of the contaminant, it was difficult to determine lactobacilli’s effect on the growth of H. ducreyi. It is crucial to understand the relationship between naturally occurring flora and the presence of infection in order to find a successful and cost efficient treatment.
Two percent CO2 is as effective as five percent CO2 in controlling febrile seizures in the mouse modelDate: Spring 2017
Major(s): Neuroscience, Biology
Thesis Committee: Dr. Lee Coates and Dr. Jeffrey Cross
Abstract: One of the most common neurological problems worldwide, epilepsy is defined as recurrent, unprovoked seizures. The main type of seizure during childhood are febrile, or fever induced seizures but there are many other types. Febrile seizures affect 3-14% of children worldwide from the age of 6 months to 6 years. The anticonvulsant properties of carbon dioxide inhalation have been proven with concentrations as low as 5%. I hypothesized that inhalation 2-3% carbon dioxide would have similar anticonvulsant effects to 5%. I used four groups of six mice which received 0%, 2%, 3%, and 5% carbon dioxide respectively. All mice were pretreated with the group’s respective carbon dioxide concentration then heated to about 47℃. Each experiment was recorded and scored on a spectrum of seizure behaviors. I have supported that 2-3% carbon dioxide has similar anticonvulsant effects to 5% carbon dioxide with no dose-response trend evident. This suggests that 2-5% carbon dioxide inhalation could prove to be an effective treatment for children displaying febrile seizures rather than the use sedatives which could cause harm or impair development. Treating children who suffer from febrile seizures with carbon dioxide may also reduce the risk of developing subsequent temporal lobe epilepsy in adulthood.
Effect of Testosterone on Male Allegheny Mountain Dusky Salamander Resistance to the Amphibian Chytrid FungusDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Susan Rankin
Abstract: Males often have higher parasite burdens than females, which is potentially due to the immunosuppressive effects of testosterone. Yet, few studies have directly investigated whether testosterone is associated with increased infection intensity in male amphibians exposed to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that has been associated with amphibian declines. If testosterone affects immune function in male salamanders, a greater number of males could die from Bd than females, leaving imbalanced sex ratios in amphibian populations. To investigate the association between testosterone and Bd infection intensity in male salamanders, I administered exogenous testosterone (or an oil control) to male Allegheny Mountain dusky salamanders (Desmognathus ochrophaeus) via transdermal patches. Half of the salamanders in each experimental group were then exposed to Bd and the other half of the salamanders were exposed to a Bd-free inoculate. Of the salamanders that were exposed to Bd (n = 17), 8 were from the testosterone treated group and 9 were from the oil control group. Only 2 salamanders tested positive for Bd 7 days post-exposure, and both individuals were from the Bd exposed, testosterone treated group. The salamander with the higher infection intensity of these 2 Bd positive individuals died before completion of the experiment. Analysis of mass change among treatment groups did not indicate an effect of Bd exposure, testosterone exposure, or their interaction on the percentage of mass change throughout the experiment. Overall, conclusions based on the results of this study were greatly affected by the low Bd prevalence, and future research remains to see if males are more likely to become infected with Bd in this host/parasite system due to the immunosuppressive effects of testosterone.
The Effects of Temperature Variations and Cutaneous Bacteria Layer Removal on Fungal Pathogen Resistance in Plethodon cinereusDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Milt Ostrofsky
Abstract: In order for organisms to fight off the myriad of diseases that can decrease population size, a strong immune system is beneficial. The immune system fuels innate immune responses that fight pathogens and viruses to keep the host healthy. Maintaining a strong immune system requires a large amount of energy, although colder temperatures make energy resources less abundant. This can leave organisms more vulnerable to infection. To combat this, some amphibians have a cutaneous bacteria layer on their skin that produces metabolites that defend the organism from pathogens. Although not part of the amphibian immune system, the cutaneous bacteria layer enhances salamander resistance to Batrachochytrium dendrobatidis (Bd). I predict when temperature is decreased, there is a decrease in amphibian immune function and increased emphasis on the cutaneous bacteria layer to fight off infection. In this experiment, I used the fungal pathogen Bd to infect Redback salamanders (Plethodon cinereus) held in two temperature treatments (~10C and ~19C). Then I removed the cutaneous bacteria layer via 3% hydrogen peroxide from half of each temperature group, forming four treatment groups that were all exposed to Bd. Removing the layer of skin bacteria should isolate amphibian immune defenses and thus show at what temperatures immune defenses can and cannot resist Bd infection. My experiment found that temperature and the cutaneous bacteria layer have no significant effect on Bd prevalence, Bd intensity or mass change in local redback salamanders. These results were unexpected and do not support the literature. Future studies should take into account the dynamic host-parasite interaction, specifically that the pattern of temperature dependent growth of the fungus may not be the same as the pattern of growth displayed by Bd in culture.
Genetic Pathway Analysis of Adolescent Idiopathic ScoliosisDate: Spring 2017
Thesis Committee: Dr. Rebecca Dawson and Dr. Tricia Humphreys
Abstract: Adolescent idiopathic scoliosis (AIS) is a musculoskeletal disorder that causes a sideways curve of the spine. The etiology of AIS is currently unknown, but there are numerous genes and single nucleotide polymorphisms (SNPs) that have been associated with AIS in recent genome-wide association studies (GWAS) and gene association studies. The purpose of this project is to investigate the potential that gene participants of a biomolecular pathway are overrepresented within the list of statistically significant genes and that variations to genes in this pathway are the underlying cause of AIS. The traditional method of pathway analysis where a systematic review of publications presenting statistically significant SNPs that are associated with genes was conducted. In addition, a novel method named “intra-GWAS pathway analysis”, which uses a list of statistically significant SNPs associated with genes from within a particular publication, was utilized. This study found multiple overrepresented pathways in the gene list generated by the traditional method of pathway analysis, but failed to find overrepresented pathways using the intra-GWAS pathway analysis. Pathways pertaining to endocrine resistance, pancreatic cancer, endochondral ossification, senescence and autophagy in cancer, stem cell differentiation, spinal cord injury response, cardiac hypertrophy, and lung fibrosis were found to be overrepresented in the population of statistically significant genes. This project was successful in identifying many candidate pathways for further investigation.
Green Frog (Lithobates clamitans) Tadpoles: Ontogenetic Shifts in Food Preference, Foraging Behavior, and their Effect on Detritus BreakdownDate: Spring 2017
Thesis Committee: Dr. Scott Wissinger and Dr. Matthew Venesky
Abstract: The role generalist benthic biofilm grazers play in detritus breakdown remains unknown. Tadpoles might shift ontogenically in foraging strategies, which could affect their role in detritus breakdown. To test this hypothesis, I observed food preference of Lithobates clamitans tadpoles at early and late developmental stages in microcosms with biofilm on both tile and detrital substrates. I found more chlorophyll a on tile substrate with late stage tadpoles compared to control and early stage treatments, whereas chlorophyll a remained constant on detritus substrates across treatments. I observed increased detritus decomposition with tadpoles, although this trend was not statistically different. Behavioral observations revealed contradictory results where early stage tadpoles spent more time on detritus compared to late stage tadpoles, and vice-versa for time near tiles. Overall, tadpoles were observed more often near or on detritus compared to tiles. These results suggest tadpoles may play an important role in detritus breakdown as they ontogenetically shift from grazer to shredder. Determining whether this breakdown is an incidental effect of grazing activity on epidetrital biofilms or a shift towards actual ingestion of the detritus substrate requires complementary dietary analysis across tadpole stages.
Developing an eDNA System to Detect and Monitor the Spread of the Invasive Round Go(Neogobius melanostomus) in the Waterways of Northwestern PennsylvaniaDate: Spring 2017
Thesis Committee: Dr. Kristen Webb and Dr. Ron Mumme
Abstract: The round goby (Neogobius melanostomus), an invasive species of fish, has recently been spotted in French Creek, an ecologically important ecosystem in Northwest Pennsylvania. Invasive species pose threats to the native biodiversity, such as food source depletion through increased competition. For effective management of an invasive population, the distribution of the population must first be characterized. Tracking invasive species using traditional techniques, such as electrofishing, can be expensive, cumbersome, and inaccurate when species are present at low densities. An alternative approach for tracking invasive species uses environmental DNA (eDNA) obtained directly from the water. eDNA detection has yet to be applied to study the presence of round goby in French Creek. In order to characterize the distribution of the population, an eDNA system of tracking has been implemented. The approach included identifying potential confounding variables and optimizing sample collection, filtration, DNA extraction, and target loci amplification using quantitative polymerase chain reaction (qPCR). Following optimization, the system was used to track the spread of the round goby in French Creek. eDNA was detected in several samples collected from French Creek, although inconsistencies in detection limit the ability to quantify the amount of DNA present.
Effects of Warming up with a Bat Weight on Muscle Activity during the Swing of College Baseball PlayersDate: Spring 2017
Thesis Committee: Dr. Lisa Whitenack and Dr. Ron Mumme
Abstract: Hitters in baseball are commonly seen preparing for their next plate appearance swinging with a bat weight to warm up. Intuition tells us that swinging a heavy object immediately before swinging an object of less mass will allow for a quicker and more forceful swing. With the increasing competition in the game of baseball, players are looking for every advantage they can get over the competition. While there have been studies that have examined the effects of a bat weight on certain aspects of the swing, few have examined muscle activity and none to my knowledge have used a pitching machine to simulate a game-like experience. Ten Allegheny College baseball players participated in this study by first completing a survey asking about their opinions and experiences with a bat weight. Surface Electromyography was used to examine the relationship between warming up with a bat weight and warming up without a bat weight. EMG signals were normalized to compare the muscle activity between the two conditions. The athletes participated in six trials of hitting off of a pitching machine in which four muscle groups (lead-arm triceps brachii, trail-arm pectoralis major, trail-leg gastrocnemius and trail-leg biceps femoris), that are considered the prime movers of the baseball swing, were examined. Results yielded no significant difference between the muscle activities of the prime movers after warming up with a weight compared to warming up without one. The majority of participants stated that they believed they would have greater muscle activity after using a bat weight during the survey which means there may be a psychological effect when warming up with a bat weight.
Short-term vs. long-term effect of thermal acclimation on Desmognathus fuscus resistance to Batrachochytrium dendrobatidis infectionDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Milt Ostrofsky
Abstract: As global temperatures continue to rise, extreme weather events are becoming more frequent, exposing animals to larger variations in temperature. These temperature changes will introduce new hosts to unfamiliar temperatures, making them more susceptible to new emerging infectious diseases. Research has shown that amphibian species are less resistant to Batrachochytrium dendrobatidis (referred to as “Bd” hereafter) when having less time to acclimate to a drop in temperature because Bd has the ability to acclimate faster due to its higher mass specific metabolic rate. To test this prediction, I conducted an experiment in which I investigated the resistance of dusky salamanders (Desmognathus fuscus) to Bd. I allowed all the salamanders to acclimate to a 6 °C drop in temperature from 24 °C to 18 °C, giving them an 8-hour, 32-hour, or 96-hour acclimation period, before being exposed to Bd. Host resistance was quantified by genomic equivalents of Bd still present on the salamanders 8 days after exposure. I hypothesized that the dusky salamanders in the 8-hour acclimation group would be less resistant with greater levels of genomic equivalents present on them and more mass lost compared to the dusky salamanders in the 96-hour acclimation period. My results, however, did not support my hypothesis. The salamanders in the 8-hour acclimation group appeared to be more resistant with lower infection prevalence and intensity, which indicates that less acclimation time may increase the resistance of hosts after a sudden decrease in temperature.
Vitamin C Inhibits the Proliferation of Canine Osteosarcoma cell line OSCA 40Date: Spring 2017
Thesis Committee: Dr. Ann Kleinschmidt and Dr. Catharina Coenen
Abstract: Osteosarcoma (OSA) is a malignant bone cancer with a poor prognosis that affects humans and canines. Human and canine OSA share many characteristics, making canine osteosarcoma (OSCA), which has a higher incidence than human OSA, an excellent model for investigating possible human OSA treatments. It has recently been shown that vitamin C is an effective treatment against colorectal cancer (CRC) where it enters through GLUT1 transporters as dehydroascorbic acid, its oxidized form, and causes cell death by increasing reactive oxygen species levels. The purpose of this study was to determine whether vitamin C inhibits the proliferation of canine osteosarcoma cell line 40 (OSCA 40), and if so, whether the mechanism may be similar to what was observed in colorectal cancer. It was determined that 0.5 mM ASC caused a significant decrease in OSCA 40 proliferation. Co-treatment of OSCA 40 with both glutathione (GSH), which blocks the oxidation of vitamin C, and 0.5 mM ASC eliminated the decrease in proliferation. Increasing the amount of glucose in the medium from 2.5 to 10 mM did not block the effect of ASC on proliferation, suggesting that DHA competes well with glucose for entry into OSCA 40 cells. Flow cytometric analysis to determine the fraction of cells with sub-G1 DNA levels did not indicate that treatment with ASC increases the amount of apoptotic cells; however, cells were treated with ASC for less time before flow cytometry than for proliferation assays. These results suggest that ASC is entering OSCA 40 cells in its oxidized form, DHA, and thus possibly decreasing proliferation through the same pathway as in CRC cells.
Effects of DEHP on Male Earwig Seminal Vesicle Size and Pheromone ReceptionDate: Spring 2017 2017
Thesis Committee: Dr. Susan Rankin and Dr. Lisa Whitenack
Abstract: Humans and animals interact with many substances daily that have the potential to impact the endocrine system. Di-ethylhexyl phthalate (DEHP) is a common endocrine disruptor mostly found in medical equipment. This experiment used ring-legged earwigs as the model to see if DEHP would affect the seminal vesicle size of male earwigs. Four groups were injected with varying amounts of DEHP: 0µg, 0.03µg, 0.3µg and 3µg. Each injected consisted of 2µL of the desired DEHP concentration. Only the highest treatment affected the seminal vesicle, and did so by elongating the structure. In accordance with DEHP feminizing males, a second study was conducted to determine if pheromone reception was altered. Using the same treatments, a 7-day old untreated female earwig was confined in a wing of a y-tube apparatus while a treated 7-day old male earwig was released. During each 20-minute trial, the number of times the male earwig visited each wing and the amount of time it took the male to first contact the female were assessed. Treatment had no effect on male behavior in these trials. Although the hypothesis was not supported, further experiments should continue to address whether DEHP affects seminal vesicles and pheromone reception.
Vinclozolin-Induced Endocrine Disruption and Epigenetic Manipulation in Ring-Legged Earwigs (Euborellia annulipes)Date: Spring 2017
Thesis Committee: Dr. Susan Rankin and Dr. Ann Kleinschmidt
Abstract: Vinclozolin is a fungicide used throughout the world on plants, ranging from produce to turf grass. It is particularly difficult to wash from the surface of produce, which makes it a potential toxicant through ingestion of contaminated food. Vinclozolin is an anti-androgenic endocrine disruptor. Exposure results in feminizing effects, such as reduced male sex organ development, sperm count, and fertility. The effects of this fungicide have been observed transgenerationally, indicating epigenetic disruption. The epigenome is highly evolutionarily conserved, and can be affected by environmental factors, including exposure to chemicals, such as vinclozolin. This research investigated the effects of vinclozolin in ring-legged earwigs, Euborellia annulipes, on the quantity and viability of eggs laid, seminal vesicle size, and global DNA methylation levels. Exposure resulted in trends of decrease in seminal vesicle size and clutch sizes. Surprisingly, hatchability increased in the “low dose” vinclozolin group. However, none of these differences were statistically significant. Global DNA methylation was reduced in adults and larvae exposed to vinclozolin, but these differences were not significant. Larval DNA methylation was significantly lower than adult samples. However, transgenerational effects of the fungicide in earwigs are yet to be determined due to insufficient larval samples sizes. Overall, vinclozolin seemed to have anti-androgenic effects in the earwigs. However, future studies are required to draw decisive conclusions.
Early Sport Specialization as a Risk Factor for Self-Reported Athletic Chronic Injuries in the Allegheny College Varsity Athletic Department: A Cross-Sectional StudyDate: Spring 2017
Thesis Committee: Dr. Rebecca Dawson and Dr. Lisa Whitenack
Abstract: An athlete is at risk for athletic injuries when they compete or practice in their particular sport. Chronic athletic injuries occur over time from repetitive muscle movements that eventually lead to microtraumas that can injure an athlete. There are certain factors an athlete can possess that may lead to a greater risk for athletic chronic injuries, including their sex, their age, and what sport they play. Early sport specialization is another possible risk factor for athletic chronic injuries. Early sport specialization refers to an athlete focusing on one sport at an early age by intense and constant practice and competition in that sport. This cross sectional study calculated the odds of an athlete at Allegheny College self-reporting a chronic injury with several risk factors such as early sport specialization, sex, age, and what type of sport they played. These variables were measured through an online survey. Respondents who self-reported a chronic injury were 0.869 times less likely to specialize in their sport early than respondents with no self-reported chronic injury (95% CI= 0.377-2.04). Also, the respondents with a chronic injury were 3.33 times more likely to be a senior than a sophomore compared to respondents with no reported chronic injury (95% CI= 1.22-9.17). While it cannot be concluded that early sport specialization, sex, or category of sport significantly affected self-reported chronic injuries, this study serves as an appropriate foundation for future studies measuring early sport specialization and self-reported chronic injuries.
Influence of Polyamines on Haemophilus ducreyi GrowthDate: Spring 2017
Thesis Committee: Dr. Tricia Humphreys and Dr. Ann Kleinschmidt
Abstract: Haemophilus ducreyi is a gram-negative bacterium that causes the sexually transmitted infection (STI) chancroid. Chancroid increases the susceptibility to additional STIs including HIV by disturbing the epithelial barriers of the vagina and creating open ulcers. Bacterial Vaginosis (BV) is a common bacterial infection that occurs when Gardnerella vaginalis becomes the primary vaginal flora resulting in an increase in pH, which disables the defense mechanisms of the vagina. Polyamines, a byproduct of BV, are derivatives of amino acids and essential for cell development. However, they are toxic at high levels. It is possible that the high concentrations of the polyamines would be enough to inhibit bacterial growth, while the lower concentrations could promote bacterial growth. G. vaginalis culture supernatant was tested to determine if the byproducts alone could inhibit the growth of H. ducreyi. Varying concentrations of cadaverine and arginine were used in an assay along with H. ducreyi to determine whether the polyamine presence would inhibit bacterial growth at high concentrations. At 100mM of cadaverine solution, growth of H. ducreyi was significantly inhibited, while the 12.5mM arginine solution significantly promoted growth. The 50% supernatant solution was also seen to inhibit bacteria growth. These results were consistent with the understanding that certain polyamines can promote growth at lower concentrations, while inhibit growth at high concentrations.
Separate vs. combined effects of snails, tadpoles, amphipods, and caddisflies on detritus decomposition in wetlandsDate: Spring 2017
Thesis Committee: Dr. Scott Wissinger and Dr. Milt Ostrofsky
Abstract: The role of animal detritivores in accelerating detritus breakdown in standing waters is poorly understood compared to in streams. Caddisflies are a commonly identified detritivore in north temperate and boreal ponds and wetlands, and previous field studies indicate they accelerate decay rates beyond that of microbial decomposition in these lentic systems. Recent studies indicate several other wetland taxa that are often described as biofilm grazers, such as snails, tadpoles, and amphipods also enhance detrital decay rates. However, the combined effects of these taxa on detritus decomposition remain unclear. The purpose of my study was to compare the separate and combined effects of these taxa on detritus processing and to determine if their effects are additive, more than additive (i.e., facilitative), or less than additive (interference). I conducted a microcosm experiment and found that snails and tadpoles enhanced detritus breakdown whereas amphipods did not. Detritus breakdown rates were highest when caddisflies, amphipods, tadpoles, and snails were combined as compared to single-species treatments indicating a synergistic effect. Although further experiments are needed to identify complementarity in feeding mechanisms and gut contents, my study suggests that these particular “cryptic detritivores” facilitate caddisfly-mediated breakdown in addition to their own detrital breakdown.
Streptococcus mutans Biofilm and Growth Inhibition by Garlic Extract in the Presence of Lactic Acid-Producing Bacteria and StarchDate: Spring 2017
Thesis Committee: Dr. Catharina Coenen and Dr. Margaret Nelson
Abstract: The oral bacterium Streptococcus mutans is one of the leading causes of dental caries, also known as cavities. Caries is directly correlated to biofilm formation. Once plaques, or biofilm, are created, S. mutans is able to metabolize sugars through glycolysis and fermentation. This process produces an acidic environment on the tooth surface, which allows for the degradation of calcium phosphate from the tooth enamel. Oral health and dietary habits influence oral flora composition. Some probiotic oral lactobacilli have been shown to inhibit growth and biofilm formation of pathogenic bacteria. Garlic (active ingredient: allicin) is a common dietary product known to exhibit antimicrobial properties and disrupt growth of various bacterial species, including S. mutans. Probiotics, garlic, and starch can be found together in some foods, like kimchi and certain cultures consume these foods with nearly every meal. To assess whether synergistic effects between lactobacilli, and garlic may disrupt establishment of S. mutans in the presence of starch, I quantified biofilm formation of S. mutans with garlic extract in isolation, or combined with lactobacilli species L. rhamnosus GR-1 and L. reuteri RC-14. In the absence of lactobacilli and starch, 5% garlic completely inhibited biofilm formation. With the addition of starch, 20% garlic extract was required to completely inhibit biofilm, while growth inhibition began at 5%. In the presence of starch, lactobacilli and garlic inhibited S. mutans growth at 1%, but the probiotic increased biofilm formation at garlic concentrations 1% and 5%. In the absence of starch, growth was again inhibited by the probiotic, but biofilm was decreased at 1% garlic concentration and increased at 5%. Treatment of starch-grown S. mutans with probiotics and garlic extract needs to be further analyzed with additional lactobacilli strains before an epidemiological study on the correlation between kimchi consumption and dental caries should be warranted.
Molecular investigation of the Northern Brine Milkvetch, Astralagus pychnostachyus var. pychnostachyus, as a conservation model for the Ventura Marsh Milkvetch, Astragalus pychnostachyus var. lanosissimusDate: Spring 2017
Thesis Committee: Dr. Kristen Webb and Dr. Ron Mumme
Abstract: Thought to have been extinct for thirty years, the Ventura Marsh Milkvetch, Astralagus pychnostachyus var. lanosissimus, was recently rediscovered in Ventura County, CA. Reestablishment of the species has been challenging due to limited success in outplanting efforts at Mandalay State Beach, McGrath State Beach, and Carpinteria Salt Marsh Reserve. Although conservationists have studied the morphological characteristics of the Ventura Marsh Milkvetch, no genetic work has been done to determine the genetic diversity of the Ventura Marsh Milkvetch population or how closely related the Ventura Marsh Milkvetch is to its model relative, the Northern Brine Milkvetch, Astragalus pycnostachyus var. pycnostachyus. The goal of this project was to perform a phylogenetic analysis by looking at the ITS and trnfM-trnS1 regions in the Ventura Marsh Milkvetch and Northern Brine Milkvetch species to determine how genetically similar the variants are to one another as well as assess the genetic diversity within the Ventura Marsh Milkvetch population. However, out of the 18 samples of both variants, only 2 Northern Brine Milkvetch samples were able to be sequenced in the ITS region. The resulting phylogenetic tree suggest that the Ventura Marsh Milkvetch may have two other model populations that could be utilized for outplanting site determinants.
Genetic analysis of domestic cat mitochondrial DNA sample from Germany for forensic database useDate: Spring 2017
Thesis Committee: Dr. Kristen Webb and Prof. Christopher Lundberg
Abstract: Cats can leave behind biological evidence at a crime scene either directly through hair, blood, or saliva, or indirectly through secondary transfer by their owners. Both nuclear and mitochondrial DNA can be found in this biological material. However, mitochondrial DNA is usually found in the hair that is found at the crime scene. In forensics, cat mitochondrial DNA has been proven to be a useful tool in linking human suspects to crimes. A database has been created with cat mitochondrial DNA samples represented from all over the world. Adding domestic cat mitochondrial DNA sequences to this database can be beneficial for forensic use. Crime scene investigators can compare the biological evidence they find at the scene to this database to help determine the value of any matches they find. This study amplified and sequenced the mitochondrial control region of 25 domestic cat samples from four German cities. Little genetic variation was observed among the German cites. When compared to other European countries, Germany showed moderate to great variation, indicating significant diversity in this geographical region. Establishing a country-specific database for Germany is important when trying to solve criminal cases from that region. Germany will only have to compare evidence to the German samples within the database.
Differences in quality of organic matter, microbial metabolism, and phosphorus species across a trophic gradient of lake sediments in Northwestern PA.Date: Spring 2017
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Milt Ostrofsky and Dr. Rebecca Dawson
Abstract: Understanding eutrophication is at the forefront of limnological research and results in substantial environmental degradation within lake ecosystems. While there exists current literature detailing the correlation between phosphorus (P) availability and the quality of sediment organic matter or between P availability and microbial communities that process the aforementioned P, there lacks investigation of the links between microbial metabolism and the quality of sediment organic matter. This study aimed at filling this gap by investigating this relationship across a trophic gradient. I hypothesized that 1) Po fractions in oligotrophic lakes would be dominated by high molecular weight polymers rather than low molecular weights sugars in eutrophic lakes and 2) there would exists qualitative differences in organic matter across a trophic gradient that would correlate with microbial metabolism. Using Biolog Ecoplates for four days and P fractionation from the sediment, I used a principle components analysis (PCA) and found that the H20 (Po and Pi), CaEDTA (Po and Pi), NaEDTA (Po), and TCA (Po at 0ºF) fractions were significantly correlated across axis one, which showed a delineation across a trophic gradient. Regarding microbial metabolism, up to 96 hours I did not find a delineation across trophic gradient, instead the eutrophic and oligotrophic lakes clustered and only began to separate at the end. The mesotrophic lakes remained more separate throughout the analysis. Although these data did not support my second hypothesis, I drew attention to the ecoplate analysis methodology and recommend that future analysis using this mechanism take the analysis of every sampling period into consideration.
Inhibition of Proliferation in Canine Osteosarcoma Cell Line 40 by Resveratrol is Correlated with an Increase in the Level of Long Noncoding RNA MALAT1Date: Spring 2017
Thesis Committee: Dr. Ann Kleinschmidt and Dr. Catharina Coenen
Abstract: Resveratrol is a dietary polyphenolic compound that has been found to have anti-proliferative and pro-apoptotic effects in a variety of cancers including osteosarcoma, meaning it holds potential as a chemotherapeutic agent. There is evidence that resveratrol acts a histone deacetylase inhibitor (HDACi). A synthetic chemical, suberoylanilide hydroxamic acid (SAHA), is also an HDACi and has been successfully used as a chemotherapeutic. In this study, the anti-proliferative effect of both resveratrol and SAHA on canine osteosarcoma cell line 40 (OSA40) was investigated using a cell proliferation assay. It was determined that 100 µM resveratrol or 1 µM SAHA significantly decreased proliferation. Global acetylation of H3 was investigated using an ELISA assay and it was determined that neither resveratrol nor SAHA caused a significant change in H3 acetylation as compared to the control. In addition, the level of a long non-coding RNA (lncRNA) metastasis-associated adenocarcinoma transcript 1 (MALAT1) in control, resveratrol, and SAHA-treated OSA40 cells was investigated by reverse transcription followed by quantitative PCR. Abnormally high levels of MALAT1 have been correlated with poor prognosis, and its depletion from human osteosarcoma cells caused cell proliferation to decrease. Both resveratrol and SAHA treatments caused a four-fold increase in MALAT1 RNA levels. These results do not support that resveratrol is acting as an HDACi for H3, however, acetylation of other proteins was not analyzed. The results also suggest that there may be a similar mechanism of how resveratrol and SAHA affect cell proliferation and MALAT1 up-regulation.
Effects of metanotal gland feeding on male-male fighting outcomes in black-horned tree crickets (Oecanthus nigricornis)Date: Spring 2017
Thesis Committee: Dr. Ron Mumme and Dr. Tricia Humphreys
Abstract: The Black-horned Tree Cricket (Oecanthus nigricornis) is a species known for its metanotal gland that plays a part in their mating practice where the females feed on contents of the gland. Previous literature has dealt with the idea of male-male conflict and how different factors affect this process. Many of these factors include size while other studies focus on the victorious parties during these conflicts. There is little or no research done on the idea of how the deposits of this gland might be a deciding factor for the “winner” when it comes to these conflicts. In this study, I looked at the effect of gland feeding on male-male competition. Overall, I saw that males whose glands were fed on by a female prior to conflict would have a lower chance of victory in a conflict and the isolated males would act more aggressively. Aggressive actions such as biting, hind-limb kicking and rearing were more frequent for unmated and undepleted males, whereas the mated males with the depleted gland showed more instances of actions like retreating which had a negative connotation and were associated with losing a given fight. In conclusion, gland feeding seemed to have a negative effect on the males under intraspecific competition conditions.
The Influence of Batrachochytrium dendrobatidis on the Metabolic Function of Plethodon cinereus and Notophthalmus viridescensDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Ron Mumme
Abstract: Hosts dealing with infection need energy in order to mount an immune response. These immune responses require energy from their host in the form of either clearing infection (resistance) or minimizing the impact on the host (tolerance). Plethodon cinereus (red back salamanders) and Notophthalmus viridescens (eastern newts) are two species of amphibian that mount a different response to Batrachochytrium dendrobatidis (Bd). Red back salamanders will resist the infection while evidence suggests eastern newts are tolerant. Both resistance and tolerance require energy to be spent by the host, ultimately increasing metabolism, but the mounting of an immune response in resistance is a more energy intensive process. In this research, I examined the metabolic rates of 20 infected vs. uninfected Plethodon cinereus (red back salamanders) and Notophthalmus viridescens (eastern newts) exposed to Batrachochytrium dendrobatidis (Bd), in particular how red back salamanders’ and eastern newts’ oxygen consumption (a proxy for metabolic rate) changes when infected vs. uninfected. Both red back salamanders and eastern newts are expected to survive Bd infection. I predict that infected red back salamanders will have a higher metabolism because of their resistance response, while eastern newts will stay relatively constant. I also predict that after an increase in metabolic rates, red backs will clear the infection and see their metabolic rates fall to the level of uninfected salamanders while newts will have little to no change in metabolic rates across the two groups. These experiments carry important implications about how hosts deal with infection. To the best of my knowledge, this kind of research has not been performed yet with Bd, and poses the opportunity to gather novel data.
The Effects of Imidacloprid and Atrazine on Nest Recognition in the Ring-legged Earwig, Euborellia annulipesDate: Spring 2017
Thesis Committee: Dr. Susan Rankin and Dr. Lisa Whitenack
Abstract: Colony collapse disorder (CCD) has threatened honeybee populations worldwide. CCD is peculiar in that beehives are abandoned by worker bees, but no dead or dying bodies are located near the hive. No certain cause of CCD has been identified. One highly-researched potential culprit is the neonicotinoid insecticide imidacloprid, which affects olfactory memory and learning and may impact hive recognition by worker bees. However, pesticide mixtures have not been studied concerning CCD. Using the ring-legged earwig Euborellia annulipes as a model system, mated female earwigs were exposed to concentrations of either imidacloprid, the herbicide atrazine, or an imidacloprid-atrazine mixture. Nest recognition was tested one day after oviposition and three days after oviposition. No significant differences in nest recognition were observed between treatment groups. However, none of the females in the imidacloprid-atrazine group returned to their nests, unlike the other groups. A larger sample size is needed to determine whether this observation could be statistically significant. Future research needs to focus on pesticide mixtures in relation to CCD because they are common in the environment and in honeybee hives specifically. Considering the contribution honeybees provide to human food supply, preventing further honeybee population declines is a critical ecological and economical issue that must be addressed.
Prenatal and Neonatal Exposure to Nicotine and Caffeine Results in an Attenuation in the Respiratory Response to CO2 in Mice: a possible link to SIDSDate: Spring 2017
Thesis Committee: Dr. Lee Coates and Dr. Rebecca Dawson
Abstract: Sudden Infant Death Syndrome is the leading cause of postnatal infant mortality in the U.S. This study was based off the Triple-Risk Model for SIDS. CO2 is an exogenous stressor. Nicotine and caffeine are possible contributors to one’s underlying vulnerability. The relationship between nicotine, caffeine, and pregnancy is complex; nicotine speeds up and pregnancy slows down the metabolism of caffeine. It was hypothesized that neonatal exposure to both nicotine and caffeine would result in a greater attenuation of the ventilatory response to CO2 compared to neonatal mice exposed to either nicotine or caffeine alone. This study used three experimental groups—Caffeine, Nicotine, and Caffeine & Nicotine—to study how newborn mouse pups respond to three minutes of increasing levels of CO2 (0%, 2%, 4%, and 6%) on Days 1, 3, 5, 7, 9, and 11. A “head out” plethysmograph chamber measured frequency and tidal volume. Frequency increased in response to CO2 over age for all experimental groups. Tidal volume and minute ventilation remained constant across days in the caffeine and nicotine group but decreased in the caffeine and nicotine group. The results supported that simultaneous exposure to caffeine and nicotine result in an attenuation of the ventilatory response to CO2 .Back to top
Assessment of Genetic Adaptation of the α-Amylase Gene in Pymatuning Lake Cyprinus carpio as a Result of Human Induced Diet ChangeDate: Spring 2017
Thesis Committee: Dr. Kristen Webb and Prof. Christopher Lundberg
Abstract: Pymatuning Lake is a man-made recreational body of water located in northwestern Pennsylvania. Spanning across the lake is a causeway that connects opposite shores to each other with a road. Along the causeway is a construct called the spillway. The spillway is a man-made concrete bowl structure that transitions the high-water levels of the sanctuary lake to the low water levels of the middle lake. This structure acts as an artificial habitat to a population of Cyprinus carpio, common carp, residing in the lake. The Pymatuning spillway offers a novel diet of starches that other populations of carp in the lake do not have. This novel diet stems from the tourists that toss in large amounts of bread to the fish that are found there. This diet separates the carp into two populations: those at the spillway, and those in other parts of the lake. The enzyme, α-amylase, aids in the digestion of these starches into simpler sugars so this makes it an excellent tool to assess adaptation between populations. This genetic adaptation was measured using a Ka/Ks test. Between populations, a single non-synonymous was found in the coding region and several gaps were identified in the non-coding regions.
Energetic Trade-offs between Reproduction and Infection Intensity in Female Plethodon cinereusDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Ron Mumme
Abstract: Sub-lethal effects of infections have the ability to alter life-history traits of an individual within a population that could potentially lead to overall decline. Life-history traits are characteristics of an organism that assist with the survival of the individual such as developmental rates and reproductive investments. Energetic trade-offs in life-history traits of individuals may bring about devastating consequences to the afflicted population in future generations. Batrachochytrium dendrobatidis (Bd) is a fungus that causes chytridiomycosis and is a leading killer of amphibians worldwide. Though it is deadly to many amphibians; red-backed salamanders (Plethodon cinereus) are resitant to Bd and therefore are a good model to use to study sub-lethal effects and life-hisotry trade-offs because of low mortality due to the infection. Both reproduction and feeding behaviors require an individual’s energy and have been shown to be altered by infection. In this study 25 P. cinereus were collected and exposed to Bd. Their feeding behavior, which was recorded as attempts to attack and successful attacks on fruit flies (Drosophila melanogaster), was observed on 7, 14, and 28 days post-exposure. The number and mass of eggs for each salamander was determined by dissection after euthanization as a measure of reproductive effort. Based on previous research, it was believed feeding behavior would increase as infection intensity did. Furthermore, it was thought that the females which had put more energy into reproduction previously would show more feeding behavior as there is an energetic input involved in the development and maintenance of eggs. It was observed that feeding behaviors did not vary between observation days regardless of infection intensity, though there was a low prevalence and abundance of Bd. The infection intensity, however, was positively correlated to the total mass of the eggs when uninfected individuals were excluded from the dataset. These results suggest that there is a possible trade-off between energy invested in reproduction resulting in the individual being more susceptible to infection. Further investigation into the way that vitellogenesis proceeds in artificial conditions and the relationship of development with infection is necessary. The susceptibility to infection as a result of reproductive effort has potential consequences to future generations.
Resistance of *Pseudomonas aeruginosa* environmental isolates from college bathrooms to triclosanDate: Spring 2017
Thesis Committee: Dr. Catharina Coenen and Dr. Lisa Whitenack
Abstract: The antibacterial agent, triclosan, has been incorporated into hand soaps for decades and is also found in other household products, such as plastics and clothing. While hand soaps do not contain enough triclosan to kill most bacteria, they may select for triclosan resistance and for cross-resistance to clinically relevant antibiotics. *Pseudomonas aeruginosa*, a bacterial species that is the leading cause of death from hospital-acquired infections, is famous for displaying high levels of antibiotic resistance as well as the ability to thrive in diverse environments. I hypothesized that *P. aeruginosa* populations in restrooms stocked with soap containing triclosan harbor a larger percentage of *P. aeruginosa* cells resistant to triclosan than populations in restrooms stocked with triclosan-free soap. To test this hypothesis, swab samples from soap dispensers, faucets, door knobs, and light switches were incubated in soap solutions with or without triclosan and then plated on *Pseudomonas*-selection agar to assess colony forming units. Exposure time to triclosan required to differentiate resistant from non-resistant strains was determined by using the resistant strain PAO1. While selection of triclosan-resistant strains of *P. aeruginosa* has been previously demonstrated for soap dispensers in hospital settings, demonstrating similar selection mechanisms in a non-clinical environment strongly supports a role for antibiotic soaps in the selection of antibiotic resistant strains in the population at large. It was found that *Psuedomonas* environmental isolates could survive plain soap treatment after having been previously exposed to triclosan-containing soap. This implies that bacterial populations are more resilient and more difficult to kill off with exposure to triclosan soap and provides added impetus for discontinuing the indiscriminate use of this antibacterial agent.
The Roles of Epidetrital Biofilms and Nutrient Regeneration from Green Frog (Lithobates clamitans) Tadpole Foraging on Detritus DecompositionDate: Spring 2017
Thesis Committee: Dr. Scott Wissinger and Dr. Matthew Venesky
Abstract: Approximately 90% of the annual global plant production enters the food web as detritus, the basal energy source for aquatic ecosystems. Energy release from detritus decomposition in wetlands is often attributed to heterotrophic microbes within the epidetrital biofilm—algae stimulate microbial growth by providing dissolved organic carbon (DOC) via the “priming effect,” and microbes stimulate algal growth by providing nitrogen and phosphorus via the microbial loop. However, there is increasing evidence that omnivorous macroconsumers are also contributors. I examined the influence of green frog (Lithobates clamitans) tadpoles on red maple leaf (Acer rubrum) detritus breakdown by manipulating tadpole presence or absence, algae density by light or low-light illumination, and inorganic nutrient retention or removal in laboratory microcosms. I predicted that breakdown would be greatest when tadpoles were present, in the light, and nutrients accumulated. Detritus breakdown was greater when tadpoles were present, in low light, nutrients accumulated, and an interaction between nutrient accumulation and low light occurred. Algae density was greater when tadpoles were present, in the light, and their interaction, and greater benthic algal biomass may have counteracted detritus mass lost. The results emphasize that tadpoles are influential in wetland detritus breakdown in addition to the biofilm.
Effects of Triclosan on DNA Integrity and Oxidative Stress of Male Xenopus laevis SpermDate: Spring 2017
Thesis Committee: Dr. Susan Rankin and Dr. Ron Mumme
Abstract: Triclosan is a common antimicrobial found in many personal care products and is a common chemical in the environment. The continuous exposure of triclosan to aquatic organisms, combined with its bioaccumulation potential, has led to detectable levels in several aquatic species. This study examines male African clawed frogs, Xenopus laevis, and the effects of triclosan at 0, 100, and 350µg/L over a 4-week period. I hypothesized that extended exposure to triclosan would cause increased damage to the DNA and oxidative stress to X. laevis sperm. DNA integrity of sperm was assessed using a comet assay and the total amount of superoxide radicals necessary to cause oxidation in the cells was measured by a superoxide dismutase (SOD) assay. Sperm cells had elevated DNA damage and decreased SOD activity as the triclosan concentrations increased. Therefore, the higher levels of triclosan in the water induced sperm DNA damage but lacked oxidative stress.
Genetic Analysis of Cytochrome b and Cytochrome c Oxidase Subunit III Genes of Cytauxzoon felis in Domestic Cats (Felis catus) from GeorgiaDate: Spring 2017
Thesis Committee: Dr. Kirsten Webb and Dr. Ann Kleinschmidt
Abstract: Cytauxzoon felis, a protozoan parasite, typically infects bobcats, but in recent decades the number of infected domestic cats has increased significantly. If left untreated, domestic cats will die of the infection within a few days. Previous research has shown that domestic cats infected with C. felis bearing specific cytochrome b genotypes respond best to atovaquone and azithromycin therapy. This project pursued the hypothesis that the cytochrome b gene shares a relationship with neighboring genes in the mitochondrial genome which may be leading to the change in treatment response across genotypes. By amplifying and sequencing the cytochrome b gene and a neighboring gene, cytochrome c oxidase subunit III, we were able to determine and compare the resulting genotypes. The cytochrome b1 and cytochrome c oxidase subunit III 2 genotypes were the most frequent genotypes. Knowing which genotypes were most common among these samples will allow veterinarians in Georgia to choose the appropriate treatment. A pattern was noted between samples carrying the cytochrome b genotype 1 and the cytochrome c oxidase subunit III genotype 2. This genotypic relationship may give us insight into why different genotypes yield different treatment responses.
Effect of temperature on Batrachochytrium dendrobatidis growth in cultureDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Margaret Nelson
Abstract: Temperature is a variable that affects all organisms due to its significant role in the processes that allow for life. More specifically, pathogens can respond in various ways to temperature differences in their environment attributable to temperature’s impact on biochemical, physiological and behavioral processes. In recent years, research has increased exploring the pathogenic chytrid fungus Batrachochytrium dendrobatidis (hereafter “Bd”) which has raised concerns due to its lethal nature in amphibians. With global change impacting host-parasite interactions, exploration into the interaction between temperature and this deadly pathogen is necessary. In multiple studies, temperature, the pathogen and the host were examined, though little research has been conducted specifically on the pathogen and its response to temperature in culture. In addition, based on past research, there is reason to believe that genotypically different isolates may display phenotypically different responses to variables such as temperature. Therefore, I investigated the isolate JEL660/JSOH-1, the isolate used in the Venesky lab for other research, and tested how temperature (12°C and 19°C) affected Bd growth rates in culture. I hypothesized that growth would be greater at 19°C due to the optimal temperature for Bd ranging from 17°C-25°C. Contrary to my hypothesis, growth rates were significantly higher at 12°C than 19°C (p < .0001). Results may be explained by a between-isolate difference with isolates explored in past research or evolution towards a lower optimal temperature during the laboratory maintenance of the pathogen. Further research is necessary to determine the cause of this phenomenon with hopes of bettering research methods in the Venesky lab as well as across the entirety of Bd research.
Patterns of Brook Trout (Salvelinus fontinalis) Distribution in Northwest Pennsylvania: a GIS AnalysisDate: Spring 2017
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Scott Wissinger and Chris Shaffer
Abstract: Historically, native brook trout (Salvelinus fontinalis) have occupied streams in northwest Pennsylvania, which is along the western most extent of their natural range. Due to extensive deforestation in the past and the introduction of non-native brown trout (Salmo trutta), brook trout have been extirpated from many streams they used to inhabit with isolated remnant populations scattered across the region. The goal of this study was to develop a region-specific model for predicting the location of brook and brown trout populations based on three main predictor variables: percent forest cover, stream gradient, and position within the watershed. I predicted the proportion of brook trout would increase with higher forest covers, stream gradients, and positions within the watershed. The top ranked model included stream gradient, watershed forest cover, and a gradient by position interaction. Brook trout occurrence increased with higher forest cover and gradient, but position only influenced the model in relationship to gradient. Few sympatric trout populations and the gradient by position relationship indicate barriers are limiting brown trout movement in this area and creating small-headwater stream refuge for brook trout from brown trout competition. Overall, promoting native brook trout populations while maintaining brown trout recreational fishing is possible through watershed conservation and the strategic stocking and reintroduction of trout.
Serial Sonification of Chaoborus Behavior in Response to Daphnia Size: The Intricacies of the Predator-Prey RelationshipDate: Spring 2017
Major(s): Biology, Music
Thesis Committee: Dr. Milt Ostrofsky, Dr. Lowell Hepler and Dr. Scott Wissinger
Abstract: Perception is something we often take for granted. There are many different ways to perceive and interpret the environment. Small aquatic creatures, such as chaoborids sense their environment differently than fish. This study looks at the rudimentary sensory mechanics of chaoborids in order to determine how refined they are. Are chaoborid mechanoreceptors fine enough to detect differences in sizes in a common prey, Daphnia pulex, resulting in a behavioral change for their preferred size of prey? Although no statistically significant differences in chaoborid behavior were observed in the presence of different sized Daphnia, an unexpected swivel behavior appeared that occurred most frequently when chaoborids were in the presence of 3-day old Daphnia. Results of this behavioral analysis were used to create a 7-member tone row, which was used in a serial composition as a means of translating the images and behaviors seen in the chaoborids into music. This sonification allows readers to perceive and interpret patterns in the chaoborid behavior in a new way which might have been lost in countless charts and figures.
Anatoxin-a Fails to Show Allelopathic Activity in the Presence of Cyanobacteria or Green AlgaeDate: Spring 2017
Major(s): Biology, French
Thesis Committee: Dr. Milt Ostrofsky and Dr. Phillip Wolfe
Abstract: Harmful algal blooms (HABs) are often the result of cyanobacteria producing dangerous toxins that contaminate the water. One such toxin, anatoxin-a, acts upon mammalian nicotinic acetylcholine receptors, resulting in symptoms such as gastro-enteritis, seizures, or even death. The evolutionary reason for anatoxin-a production may be 1) a byproduct of metabolism, 2) a defense against herbivory, or 3) an allelopathic agent. No such metabolic pathways have been found, and little evidence points towards a defense to herbivory beyond the mammalian effects. With mammals not being the primary consumers, this leaves allelopathy as the most likely option. This study investigated this third option through exposing cyanobacteria (Anabaena flos aquae, Microcystis aeruginosa, and Oscillatoria agardhii) and green algae (Pediastrum duplex, Scenedesmus quadricauda, and Staurastrum paradoxum) to varying concentrations of anatoxin-a from low environmental levels to those denoted as too dangerous for human contact. Despite anticipated enhancement of cyanobacterial growth and suppression of green algal growth, no growth rates were found to have a significant enhancement or suppression by the toxin (p<0.05). Results did not give clear support for the use of anatoxin-a as an allelopathic agent of cyanobacteria.
Cataract prevention in bovine lens: the effects of vitamin E and astaxanthin on protein oxidationDate: Spring 2017
Thesis Committee: Dr. Christine Donmoyer and Dr. Margaret Nelson
Abstract: Cataract, which involves a dramatic opacification of the lens, is the leading cause of blindness in humans. The clouding of the lens is caused in part by the oxidation of crystallin lens proteins by reactive oxygen species (ROS). Antioxidants work to reduce oxidative damage by removing free radicals like ROS. This study investigated the ability of the antioxidants vitamin E and astaxanthin to reduce oxidative damage in bovine lenses. Lenses were kept in individual vials and treated with 20 µM vitamin E, 100 µM vitamin E, 20 µM astaxanthin, or 100 µM astaxanthin or HEPES buffer for 48 hours. Lenses were then subjected to oxidative stress via 24 hour exposure to 1 mM H2O2 and homogenized. A colorimetric protein carbonyl assay was used to measure the amount of protein carbonyls (nmol/mg) in each sample, an indicator of oxidative stress. Though not significant, lenses exposed to 20 µM vitamin E (4.84 ± 0.88) and 20 µM astaxanthin (4.89 ± 0.45) had lower levels of protein carbonyls than the lenses in buffer (5.45 ± 1.01). In addition, lenses exposed to 100 µM vitamin E (5.67 ± 1.33) and 100 µM (5.94 ± 0.72) tended to have higher levels of protein carbonyls than lenses in buffer. Vitamin E and astaxanthin were not different in the ability to protect against lens protein oxidation. The findings suggest that astaxanthin and vitamin E have similar capabilities as antioxidants and that a low dose of antioxidant could be more effective than a high dose for preventing cataract formation. This is relevant for patients taking dietary supplements as a preventative measure against cataracts.
Effects of acute iron overload on the testis, epididymis, and serum testosterone levels in C57BL/6J male miceDate: Spring 2017
Thesis Committee: Dr. Susan Rankin and Dr. Rebecca Dawson
Abstract: Iron is an essential nutrient in all living organisms. Excess iron can act as a catalyst, producing harmful reactive oxygen species (ROS). ROS cause oxidative stress on tissues, damaging affected organs. Oxidative stress contributes to numerous disorders in humans, such as hypogonadism. Hypogonadism affects 2-4 million males in the United States, and is caused by iron overload in the hypothalamic-pituitary-gonadal (HPG) axis. Damage to the HPG axis can cause dysfunction of the gonads and infertility. Low serum testosterone levels are also associated with hypogonadism. This research utilized 6-week-old C57BL/6J male mice, with 5 mice per group: (i) untreated control, (ii) solvent control = 9.4 μL of 0.5 % phenol, (iii) 0.25 mg iron-dextran (ID)/ day, and (iv) 37.5 mg ID/ day for three weeks. Treatments were applied to chocolate pellets. It was hypothesized that iron-dextran would decrease testis and epididymis weights, decrease sperm numbers and increase incidence of sperm abnormalities in the testis and epididymis. Lastly, I predicted that there would be an inverse relationship between serum testosterone levels and iron-dextran. All hypotheses assumed 0.5% phenol preservative in iron-dextran would be innocuous. Body, testis, and epididymis weights were not altered by treatment. ID treatments had a dose dependent effect on sperm count and deformity in both the testes and epididymis. Interestingly, phenol and high ID treatment induced similar findings, suggesting that phenol is responsible for observed changes. Serum testosterone trends could not be determined. Overall, more testing must be done to confirm effects of iron and phenol.
Evolution of Predatory Methods of the muricid subfamily Ocenebrinae using a Phylogenetic FrameworkDate: Spring 2017
Major(s): Biology, Geology
Thesis Committee: Dr. Lisa Whitenack and Dr. Rachel O'Brien
Abstract: "Various modes of predation were compared between and within clades of the muricid gastropod subfamily Ocenebrinae. This particular group of species is easily observable in nature and relatively well documented throughout the fossil record. Recent advances in technology have allowed for genetic testing and therefore phylogenetic mapping. Through phylogeny, we are able to detect trait patterns within and between clades. One particular area of interest to map and analyze is predatory techniques in Ocenebrinae clades, as the techniques have not yet been studied. Predatory techniques can be both observed and predicted based on anatomical characteristics and geographic location, depending on the time period of their evolution.
After an extensive literature search, data was entered into Mesquite 3.2 to create phylogenetic trees that were used to compare modes of predation to anatomical characteristics and geographic locations. Both pairwise and mirror tree comparisons were conducted for each character for the 24 Ocenebrinae species used in this study, however, no patterns were found. Phylogenetic mapping should allow one to reconstruct past traits and to understand the directionality of evolution. Without patterns, it is challenging to understand the origin of various traits and why such traits have appeared when and where they have. Therefore, more research should be conducted on more characters, other Ocenebrinae species, and closely related subfamilies to determine if any correlations could be drawn between characters and evolution."
The effects of morphospace occupation and variation on genus survivorship through mass extinctionsDate: Spring 2017
Thesis Committee: Dr. Lisa Whitenack and Dr. Kristen Webb
Abstract: Mass extinctions can halt evolutionary trends in ecological or geological time (Gould 1985). Tropical, deep-water lineages of class Trilobita expanded through morphospace (quantified organismal shape, as in Foote 1990) during the Ordovician period (Hopkins 2014). However, the extinction at the end of this period hurt deep-water fauna (Owen et al. 1991). Surviving lineages refilled newly opened niches in ecospace (Erwin 1998), but not much is known about the link between survivorship through a mass extinction and prior morphospace use.
Paleontologists are limited to studying changes in the shape and form of physical remains in order to measure evolutionary change in extinct species. Geometric morphometrics is a class of techniques that can analyze shape change without the confounding effects of size or rotational orientation (Zelditch et al. 2004); the results of GM analyses can be used to study lineages’ occupation of morphospace, or expansion into all possible forms of structure and shape (Foote 1990).
This study examined variation and use of morphospace, as captured by geometric morphometrics, in trilobite families throughout the late Ordovician and early Silurian. Occupation of morphospace was compared among and within groups before the event, as well as between pre- and post-extinction groups.
Glycosuria effects on Pseudomonas aeruginosa PAO1 Biofilm Formation on Common Catheter MaterialsDate: Spring 2017
Thesis Committee: Dr. Catharina Coenen and Dr. Margaret Nelson
Abstract: "Catheter-associated urinary tract infections (CAUTIs) are the most common hospital-acquired infections and a leading cause of death in elderly patients. Risk for acquiring a CAUTI within an intensive care unit is increased five-fold by Diabetes Mellitus, suggesting that increased concentrations of glucose in the urine may increase bacterial colonization of catheter surfaces, and hence the formation of antibiotic-resistant biofilms. Novel approaches, such as coating of catheters with antimicrobials, have been ineffective against gram negative bacteria, such as Pseudomonas aeruginosa, but interactions between catheter materials and glycosuria have not been investigated.
To assess effects of glucose at concentrations found in diabetic patients on colonization of catheter materials, I compared P. aeruginosa growth and biofilm formation in a nutrient-rich medium, M63, and in an artificial urine medium (AUM). On the polystyrene surface of a standard microtiter dish, glucose increased both growth and biofilm formation in M63. However, in AUM, glucose only increased growth but not biofilm formation. Biofilm formation on common catheter materials was assessed in the presence or absence of glucose by inserting catheter sections into wells containing AUM and determining biofilm growth per area through staining with crystal violet and quantification of dye retained on the catheter. Overall, catheter type had a significant effect on both biofilm formation, and, the interaction between glucose and catheter material. Interactions between glucose and catheter materials may provide a basis for a clinical comparison of particular catheter materials in patients with Diabetes Mellitus.
Estrogen Fluctuations in the Female Menstrual CycleDate: Spring 2017
Thesis Committee: Dr. Rebecca Dawson and Prof. Christopher Lundberg
Abstract: The female menstrual cycle (Figure 1) is a series of changes that women go through in order to prepare for reproduction (Sharma et al., 2016). Hormones present during the menstrual cycle can fluctuate depending on a number of mental and physical health factors (Manikandan et al., 2016). Estrogen is produced in women and most present during ovulation in the menstrual cycle (Stijak et al. 2015). Estradiol is responsible for female sex characteristics and sexual functioning (Otag et al., 2016). The effect of exercise on estrogen levels in the female menstrual cycle is examined in this experiment. Two groups of human females participated – ten active females and eight females that are not active on a regular basis. Saliva samples were collected on day one and day fourteen of each participant’s menstrual cycle. On day one of their menstrual cycle, participants completed a survey to determine the demographics of each participant. An estradiol enzyme-linked immunosorbent assay (ELISA) was performed on each sample to measure the amount of estrogen in each sample. There was no significant difference between active and non-active participants on day one of sample collection (F(1) = 0.1553, P = 0.6988) (Figure 3). There was no significant difference between active and non-active participants on day fourteen of sample collection (F(1) = 0.000, P = 0.9980) (Figure 4). There was no significant difference between day one and day fourteen of the female menstrual cycle (Figure 5). The purpose of this experiment was to determine the influence of physical activity on estrogen levels in women.
The Effects of Alachlor Exposure on Adult Female Euborellia annulipes and Resulting OffspringDate: Spring 2017
Thesis Committee: Dr. Susan Rankin and Prof. Christopher Lundberg
Abstract: The use of herbicides in modern agriculture has become common practice since their introduction in the 1940s. While the benefits are observed though high crop yield, the potential side effects of these chemicals are currently being assessed. Alachlor is a common herbicide that is utilized to prevent pre-emergence of broadleaf weeds and grasses. While alachlor is a human carcinogen at high concentration levels, its effects at environmental concentrations require further observation. This study utilized the invertebrate system Euborellia annulipes (ring-legged earwig) to examine the effects of alachlor exposure on adult females and resulting offspring. Females exposed to levels of alachlor found in surface water of agricultural developments had significantly smaller clutch sizes than did non-exposed and those exposed to concentrations similar to agricultural ground water concentrations. Overall growth, basal follicle length on day 10 post oviposition, length of embryogenesis, hatching success rate, and behaviors including cannibalism and mating remained unchanged. E. annulipes thus provides a useful model for assessing potentially toxic environmental contaminants. Additionally, understanding the mechanisms by which alachlor affects reproduction in earwigs may lead to practical methods of pest suppression.
Determining tolerance to Batrachochytrium dendrobatidis in Notophthalmus viridescens newts through leukocyte analysisDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Susan Rankin
Abstract: Hosts can display two different mechanisms in attempts to protect themselves from invading pathogens/parasites: resistance or tolerance. Resistance is defined as the ability of a host to prevent and/or limit parasite burden. In a tolerant host, the host is attempting to limit damage done by the given parasite. Tolerance saves the host from harm that a parasite may cause without causing direct negative effects to the parasite. One way to measure a host’s response to a pathogen is through leukocyte counting. In a resistant host, leukocyte numbers should vary from infected to uninfected, as their blood cells are in use to fight infection. In a tolerant host, it would be predicted that leukocyte numbers wouldn’t exhibit a change because leukocytes are associated with resistance and not tolerance. Previous experiments suggest that the Eastern red-spotted red newts (Notophthalmus viridescens) are tolerant to the amphibian chytrid fungus, Batrachochytrium dendrobatidis (hereafter “Bd”); however this has not been experimentally evaluated. I exposed Notophthalmus viridescens to Bd and quantified aspects of their cell-mediated immunity, Bd infection intensity, and percentage of mass change. I hypothesized that Bd+ and Bd- newts would produce the same leukocyte profiles, exhibiting no leukocyte response to this pathogen; (i.e., that they are tolerant to Bd). Also, I hypothesized that prevalence and infection intensity would be relatively high among the exposed group and no significant mass would be lost, which also suggests they are tolerant to Bd. No significant differences were found between the leukocyte profiles in either treatment groups among any of the leukocytes counted. However, 4 of the 5 newts that were infected 9 days post infection managed to clear the infections 14 days post infection indicating that they can clear Bd (i.e., that they exhibit resistance to Bd also) without elevating their cell-mediated immune response. In addition, no significant relationship was found between percent mass change 9 days post exposure and infection intensities, indicating tolerance. Together, the results of this study indicates tolerance and resistance are not mutually exclusive among amphibians.
Effect of Electrolyte Treatment on Batrachochytrium dendrobatidis Infected Rana pipiensDate: Spring 2017
Thesis Committee: Dr. Matthew Venesky and Dr. Lee Coates
Abstract: Decreases in amphibian species continue to be observed on a global scale, which in part is due to a rise in a fungal infectious disease. Batrachochytrium dendrobatidis (Bd) is the front-runner of fungal diseases that is causing amphibian population declines. Research suggests that infected amphibians lack the ability to retain proper electrolyte balance which, in turn, leads to cardiac arrest and then death. A majority of researchers have supplemented antifungal therapy with electrolyte treatments to combat Bd infections. However, it is suggested that electrolyte treatment alone is capable of prolonging the infected animal’s life. My research aimed to test whether electrolyte treatments are effective in prolonging the life of Northern leopard frogs (Rana pipiens) infected with Bd. I infected 10 frogs with Bd and treated with them electrolytes for a short period of 5 days and one group for a longer period of 10 days. I tracked the development of Bd, chytridiomycosis, as well as weight loss. I hypothesized that the replenishment of electrolytes the frogs received from the electrolyte treatment would prolong the frog’s life while infected with Bd. At the end of the experiment there was no mortality and a 20% prevalence rate throughout the Bd exposed groups. Statistical analysis determined that the effect of electrolyte treatment was marginally significant to average percentage mass change and the effect of pathogen on average percent mass change was not significant throughout the experiment.
The Effect of the Herbicide Roundup on Female Mate Choice in Guppies (Poecilia reticulata)Date: Spring 2017
Thesis Committee: Dr. Ron Mumme and Dr. Kirsten Webb
Abstract: Roundup, which contains non-ionic, polyethoxylated tallowamine (POEA) surfactant and the active ingredient glyphosate, is one of the most commonly used glyphosate-based herbicides globally. According to the World Health Organization, Roundup does not pose a threat to animals; however, concerns remain about how this herbicide may negatively affect aquatic ecosystems due to the longevity and persistence of chemicals in these environments. Presently, not much is known about how fish behave under the presence of Roundup in their environment. Because guppies (Poecilia reticulata) are a model organism for sexual selection and toxicology studies, I studied the effect of an environmentally relevant, sublethal concentration of Roundup on female choice in guppies. Over a period of 16 days, female guppies were exposed to 700 μg/L of Roundup. On days 1, 2, 4, 7, 11, and 14, female fish underwent preference trials to evaluate their inclination for bright males. On days 15 and 16, I evaluated female guppies’ sexual receptivity behavior in the direct presence of males. Collectively, control female guppies preferred bright males on days 1 and 2 (n = 6, P = 0.044), but did not exhibit a preference for either bright or dull males on all subsequent days. Female guppies exposed to 700 μg/L of Roundup strongly preferred bright males on day 1, but, they did not exhibit a strong preference for either bright or dull males on the following days. Additionally, neither group of females exhibited strong receptivity to males. Although, this study demonstrates that short-term Roundup exposure (48 hours) could have affected female choice in guppies, further research is needed to more thoroughly examine the short- and long-term effects of Roundup exposure on fish behavior. More holistically understanding the consequences of commonly used herbicides on wildlife is important so these chemicals can be used more safely and conservatively, or so safer methods of eliminating weeds can be researched for future use.
Determining sexual dimorphism in the cheetah (Acinonyx jubatus spp.) through cranial and dental morphologyDate: Spring 2017
Thesis Committee: Dr. Lisa Whitenack and Christopher Lundberg
Abstract: The Felidae family is composed of various species ranging from the largest felid, the tiger (Panthera tigris) to the smallest, the kodkod (Leopardus guigna). Cheetahs were first seen in the Late Miocene era, approximately seven million years ago. Studying the morphology of these felids will allow researchers to understand different social behaviors to better their conservation efforts. Sexual dimorphism, or differences in size and appearance of individuals of different sexes, is a phenomenon that has been documented in living carnivores, especially felids. Members of the Felidae family that have been previously reported to be sexually dimorphic include, lions (Panthera leo) and tigers (Panthera tigris). However, its presence in the cheetah (Acinonyx jubatus) is not a very well known. Much of this uncertainty stems from their proximity to extinction; this carnivore has been reduced to small, fragmented populations throughout the African continent. The cheetah has been reported as being sexually dimorphic in size with regards to their body mass, canine tooth, body length and chest girth. However, previous studies have not looked at sexual dimorphism in regards to cranial and dental morphology. I hypothesize that due to the low genetic variation, the cheetah will not be sexually dimorphic. This study uses geometric morphometric techniques of Procrustes superimposition and resampling- based Goodall’s F-test. Although cheetahs have been shown to be sexually dimorphic in body size, results from this show that male and female cheetah were not sexually dimorphic in regards to craniodental features.