Abstracts Archives: Abstracts

Afjeh, Tara: Sexual Behavior of Male Guppies (Poecilia reticulata) in Response to the Glyphosate-based Herbicide Roundup

Altmeyer, Aaron: Tick prevalence on the white-footed mouse, Peromyscus leucopus, in Bousson Environmental Research Reserve

Arcieri, Michael: An Analysis of Genetic Diversity in the Pennsylvania State Population of White-Tailed Deer (Odocoileus virginianus) 110 Years After Bottleneck and Translocation

Arison, Miranda: Probiotic Interference and Fibronectin Binding in Haemophilus ducreyi without dsrA

Atcheson, Karla: Comparison of the Preventative Effects of Vitamins C and E in the Formation of Cataracts in Murine Lenses

Aulicino, Jessica: Interactions Between Haemophilus ducreyi and Bacteria Found in the Male Urogenital Normal Flora

Avolio, Theodore: Creating the fbiA-fbiB- Double Null Mutant in Dictyostelium discoideum

Bacharach, Dana: The Effects of Omega-3 Fatty Acid and Exercise on Olfaction and Memory on Alzheimer’s Disease In Mice

Beaty, Sierra: Growth of Haemophilus ducreyi in the Presence of the Male Normal Flora Corynebacterium glucuronolyticum and Mycobacterium smegmatis

Bell, Emilie: Effects of Pseudomonas fluorescens-produced antibiotic 2,4-Diacetylphloroglucinol on Chestnut Blight fungus Cryphonectria parasitica

Berry, Joanna: The effects of barriers and brown (Salmo trutta) on fish communities in northwestern Pennsylvania

Billet, Logan: Temporal and interspecific variation of the amphibian chytrid fungus Batrachochytrium dendrobatidis in northwest Pennsylvania

Boleratz, Kayla: Vertebrate hormones in insects: Effects of Beta-Estradiol on mating, pre-oviposition time, fecundity, and fertility in the female ring-legged earwig, Euborellia annulipes

Bullis, Jessica: Effects of Detritivores on Detritus Breakdown in Wetlands: Do Detritivores Matter?

Campbell, Kaitlyn: Effects of the black spot disease parasite, Uvulifer amblopliti, on the behavior of blacknose dace

Carver , KayLynn: The Benefit of Resveratrol and Quercetin Co-treatments in Canine Osteosarcoma

Choi, Jeannie: Differentiation of Cat Littermates by Means of Mitochondrial Control Region Sequencing

Chung, Paul: Apoptotic Gene Expression of the AP-1 Transcription Factor in IRBP -/- Mice

Clark, Selena: Cross-modal Human Gender Discrimination by Domestic Dogs (Canis familiaris)

Clarke, Margaret: Are Anxiety and Depression in Offspring Caused by an Induced Immune- Response in Mothers During Pregnancy?

Clogan, Kaelin: The Effect of Aquatic Surface Area on Frog Resistance to a Fungal Pathogen

Cole, Sarah: Comparing bactericidal effects of sodium hypochlorite (NaOCl) solution and gel on Porphyromonas gingivalis: bacteria associated with periodontal pathogenesis.

Collins, Sean: How Previous Stressors Affect Disease Resistance in Red-Backed Salamanders

Craft, Laura: Can Female Red-Backed Salamanders, Plethodon cinereus, use Olfactory Signaling to Determine the Presence of Batrachochytrium dendrobatidis in Potential Mates?

Cuellar, Stephanie: Vitamin C Sensitivity of Canine Osteosarcoma Cells is Not Explained by KRAS or BRAF Mutations

Danisi, Jacqueline: "Changes in Lactobacilli Probiotic Concentration After Exposure to Haemophilus ducreyi and Unknown Contaminants **(Haemophilus ducreyi needs to be italicized)**"

Daugherty, Daniel: Two percent CO2 is as effective as five percent CO2 in controlling febrile seizures in the mouse model

Dillon, Morgan: Effect of Testosterone on Male Allegheny Mountain Dusky Salamander Resistance to the Amphibian Chytrid Fungus

Doran, Alexandra: Fruit Size in Flowering Dogwood (Cornus florida): Effects on Avian Frugivory and Seed Dispersal

Durant, Lauren: Preferential Mate Choice in Plethodon cinereus Based on Among-Population Variation in Chemical Cues

Eckhardt, Hayley: Effects on embryo development in Oryzias latipes exposed to di-2-ethylhexyl phthalate (DEHP)

Emerson, Kyle: The Effects of Temperature Variations and Cutaneous Bacteria Layer Removal on Fungal Pathogen Resistance in Plethodon cinereus

Fallon, Hannah: Transmission of Haemophilus ducreyi by Musca domestica

Favaro, Daniel: Genetic Pathway Analysis of Adolescent Idiopathic Scoliosis

Finigan, Rachael: Green Frog (Lithobates clamitans) Tadpoles: Ontogenetic Shifts in Food Preference, Foraging Behavior, and their Effect on Detritus Breakdown

Garlick, Callie: You can't Judge a Horse by its Color: Examining the Relationship between Horse Coat Color and Personality

Grace, David: Effects of Soy Infant Formula on Growth and Sexual Development in C57BL/6J Mice

Gribik, Zachary: Developing an eDNA System to Detect and Monitor the Spread of the Invasive Round Go(Neogobius melanostomus) in the Waterways of Northwestern Pennsylvania

Griffin, Colby: Effects of Warming up with a Bat Weight on Muscle Activity during the Swing of College Baseball Players

Happel, Rhet: Short-term vs. long-term effect of thermal acclimation on Desmognathus fuscus resistance to Batrachochytrium dendrobatidis infection

Hawk, Nicole: The Influence of Corynebacterium jeikeium on Haemophilus ducreyi growth

Horosko, Emily: Vitamin C Inhibits the Proliferation of Canine Osteosarcoma cell line OSCA 40

Husnick, Zoe: Different doses of Batrachochytrium dendrobatidis Affect Secretion of Corticosterone in Plethodon cinereus

Kalamasz, Kayla: Effects of DEHP on Male Earwig Seminal Vesicle Size and Pheromone Reception

Kelly, Leah: The Female Flora: Inhibition of Haemophilus ducreyi and Gardnerella vaginalis Growth by Presence of Vaginal Lactobacillus

Kelly-DeMello, Justine: The Effects of 17β-Estradiol on Neurogenesis in Crayfish Procambarus clarkii

Kinnamon, Benjamin: Evidence for the Existence of Genital Sex Pheromones in Ixodes scapularis

Klein, Nichole: Vinclozolin-Induced Endocrine Disruption and Epigenetic Manipulation in Ring-Legged Earwigs (Euborellia annulipes)

Krainz, Leah: Comparison of heat shock transcription factor mRNA sequences and expression in Brassica rapa and Arabidopsis thaliana

Krasa, Felicia: The detection of the amphibian fungal pathogen Batrachochytrium dendrobaditis in a population of Cryptobranchus alleganiensis, the Eastern Hellbender, in a Pennsylvania Creek

Landowski, Allison: Early Sport Specialization as a Risk Factor for Self-Reported Athletic Chronic Injuries in the Allegheny College Varsity Athletic Department: A Cross-Sectional Study

Lange, Carissa: Diurnal temperature variation hinders an amphibian host's ability to clear the fungal pathogen, Batrachochytrium dendrobatidis

Lattin, Chloe: Influence of Polyamines on Haemophilus ducreyi Growth

Leja, Liana: Separate vs. combined effects of snails, tadpoles, amphipods, and caddisflies on detritus decomposition in wetlands

Lynn, David: Streptococcus mutans Biofilm and Growth Inhibition by Garlic Extract in the Presence of Lactic Acid-Producing Bacteria and Starch

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

Mamula, Olivia: Effects of LCD light exposure during the dark phase on learning and memory in mice

Massart, Taylor: Genetic analysis of domestic cat mitochondrial DNA sample from Germany for forensic database use

Mattwig, Melissa: Differences in quality of organic matter, microbial metabolism, and phosphorus species across a trophic gradient of lake sediments in Northwestern PA.

McDermott, Mollie: Effects of exogenous testosterone on pregnant mice, their maternal care, and their offspring

McDowell, Kevin: Effects of Chronic Stress During Middle Childhood on Brain Development

Meehan, Madison: Inhibition of Proliferation in Canine Osteosarcoma Cell Line 40 by Resveratrol is Correlated with an Increase in the Level of Long Noncoding RNA MALAT1

Micheal, Hunegaw: Effects of metanotal gland feeding on male-male fighting outcomes in black-horned tree crickets (Oecanthus nigricornis)

Nagael, James: The Influence of Batrachochytrium dendrobatidis on the Metabolic Function of Plethodon cinereus and Notophthalmus viridescens

Nelson, Alyssa: The Effects of Imidacloprid and Atrazine on Nest Recognition in the Ring-legged Earwig, Euborellia annulipes

Nguyen, Jasmine: Prenatal and Neonatal Exposure to Nicotine and Caffeine Results in an Attenuation in the Respiratory Response to CO2 in Mice: a possible link to SIDS

Nolte, Alex: Assessment of Genetic Adaptation of the α-Amylase Gene in Pymatuning Lake Cyprinus carpio as a Result of Human Induced Diet Change

Orr, Kayla: Treating the Ischemic Penumbra with Propentofylline and Minocycline

Pariyar, Keva: Energetic Trade-offs between Reproduction and Infection Intensity in Female Plethodon cinereus

Pearson, Chelsea: The Effect of Dog Appeasing Pheromone Combined with Exercise on Anxiety Levels of Dogs (Canis lupus familiaris) Boarded at Kennels

Pellegrini, Laura: Resistance of *Pseudomonas aeruginosa* environmental isolates from college bathrooms to triclosan

Petro, Mary: The Roles of Epidetrital Biofilms and Nutrient Regeneration from Green Frog (Lithobates clamitans) Tadpole Foraging on Detritus Decomposition

Recke, Autumn: Effects of Triclosan on DNA Integrity and Oxidative Stress of Male Xenopus laevis Sperm

Reed, Julianne: The Effects of Bisphenol A on Adult C57BL/6J Male Mice Fertility

Rodrigues, Megan: Genetic Analysis of Cytochrome b and Cytochrome c Oxidase Subunit III Genes of Cytauxzoon felis in Domestic Cats (Felis catus) from Georgia

Rollin, Victoria: Effect of temperature on Batrachochytrium dendrobatidis growth in culture

Rosswog, Anna: Patterns of Brook Trout (Salvelinus fontinalis) Distribution in Northwest Pennsylvania: a GIS Analysis

Ruszczyk, Melissa: Serial Sonification of Chaoborus Behavior in Response to Daphnia Size: The Intricacies of the Predator-Prey Relationship

Rzodkiewicz, Lacey: Anatoxin-a Fails to Show Allelopathic Activity in the Presence of Cyanobacteria or Green Algae

Schuver, Veronica: Cataract prevention in bovine lens: the effects of vitamin E and astaxanthin on protein oxidation

Sheppeck, Alexandra: The Inhibitory Effect of Bacteria of Circumcised and Uncircumcised Males on the Growth of Haemophilus ducreyi

Shipe, David: Influence of Tree Species and Soil Properties on Maco-Invertebrate Community Diversity

Sortino, Onalee: The effects of nicotine withdrawal on the development of a ventilatory response to CO2 in neonatal mice: A possible link to SIDS

Stengel, Jessica: Effects of acute iron overload on the testis, epididymis, and serum testosterone levels in C57BL/6J male mice

Stewart, Meghan: Evolution of Predatory Methods of the muricid subfamily Ocenebrinae using a Phylogenetic Framework

Stigall, Tyler: The effects of morphospace occupation and variation on genus survivorship through mass extinctions

Stookey, Jessica: Pre-pregnancy & early pregnancy exposure to Isotretinoin (Accutane®) in Laboratory Mice Mus musculus and Birth Outcomes

Sutkowski, Paul: Epigenetic Inheritance of Temperature-Induced Variation in Tail Lengths in Mice

Taylor, Rachael: Glycosuria effects on Pseudomonas aeruginosa PAO1 Biofilm Formation on Common Catheter Materials

Thiessen, Jessie: Estrogen Fluctuations in the Female Menstrual Cycle

Thomas, Samuel: Developing an Ethical and Effective Murine Model for Type 1 Diabetes Mellitus-Induced Cataract via Single Dose of Streptozotocin

Tilley, Matthew: The Effects of Alachlor Exposure on Adult Female Euborellia annulipes and Resulting Offspring

Vescio, Brittini: Determining tolerance to Batrachochytrium dendrobatidis in Notophthalmus viridescens newts through leukocyte analysis

Ward, Kenton: Effect of Electrolyte Treatment on Batrachochytrium dendrobatidis Infected Rana pipiens

Wehrer, Kathryn: The impact of temperature on rates of cannibalism in Ambystoma mexicanum

Weinstein, MacKenzie: Perinatal Exposure to 5-Hydroxytryptophan (5-HTP) Results in an Increased Breathing Frequency in Response to Hypercapnic Conditions in Neonatal SERT- Mice: A Possible Link to SIDS

Wildt, Amanda: The Effects of Photoperiod on Behavior in Rana clamitans Tadpoles

Woods, Michelle: Effects of disease pathology on nutrient cycling in aquatic systems

Yemc, Madison: The Effect of the Herbicide Roundup on Female Mate Choice in Guppies (Poecilia reticulata)

Yerramreddy, Ananya: Determining sexual dimorphism in the cheetah (Acinonyx jubatus spp.) through cranial and dental morphology

Zimmer, Harper: The effects of social partners on behavioral and physiological stress in a novel environment: Do domestic chicks (Gallus gallus domesticus) form strong social attachments?


Afjeh, Tara

Sexual Behavior of Male Guppies (Poecilia reticulata) in Response to the Glyphosate-based Herbicide Roundup

Date: Spring 2017
Major(s): Biology
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.

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Altmeyer, Aaron

Tick prevalence on the white-footed mouse, Peromyscus leucopus, in Bousson Environmental Research Reserve

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Matthew Venesky, Dr. Rebecca Dawson

Abstract:

Arthropod-borne diseases are transmitted via pathogens and can infect a wide range of hosts. Lyme disease (LD) is the most prevalent arthropod-borne disease in North America and Europe. The primary vector for LD, the blacklegged tick (Ixodes scapularis), and the primary reservoir for LD, the white-footed mouse (Peromyscus leucopus), were studied during this experiment. Factors such as temperature and acorn presence were tested to see if they had an effect on tick prevalence and mouse abundance. I hypothesized that as ambient temperature decreases, mouse abundance will increase. Tick prevalence would also increase as ambient temperature decreases due to mice being more active at cooler temperatures. I also hypothesized that transect 1 and transect 2, which had acorns present, would have higher catch rates than transect 3 and transect 4, which did not have acorns present. This research was conducted during the months of September and October at Bousson Environmental Research Reserve in Meadville, Pennsylvania. Sixteen traps between 4 different transects were set up at dusk and then checked the following morning. Mice that were caught were examined visually for ticks and then released at the site of capture. I found that as minimum ambient temperature decreased mouse abundance increased. As minimum ambient temperature decreased tick prevalence also increased. Transect 1 and transect 2 had the highest catch rate, which was expected due to the presence of acorns. These results were expected and are consistent with the literature. Future studies could be conducted by extending the trapping range and increasing the variability in habitats between transects. It would also be useful to remove ticks from captured mice and run quantitative polymerase chain reaction (qPCR) to test the prevalence of LD in Bousson.

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Arcieri, Michael

An Analysis of Genetic Diversity in the Pennsylvania State Population of White-Tailed Deer (Odocoileus virginianus) 110 Years After Bottleneck and Translocation

Date: Spring 2017
Major(s): Biology
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.

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Arison, Miranda

Probiotic Interference and Fibronectin Binding in Haemophilus ducreyi without dsrA

Date: Spring 2017
Major(s): Biology
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.

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Atcheson, Karla

Comparison of the Preventative Effects of Vitamins C and E in the Formation of Cataracts in Murine Lenses

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Christine Donmoyer, Dr. Matthew Venesky

Abstract:

Age-related cataracts are the cause of nearly 50% of all cases of blindness worldwide and about half of all visual impairment cases in the USA. Research has shown that the consumption of antioxidants may help reduce the severity of the cataract formed in the lens. The aim of this study was to compare the preventative effects of vitamins C and E in the formation of cataracts in murine lenses. Whether vitamins C and E have a synergistic effect was also tested. Wild-type mice were given weekly vitamin injections for four weeks. At the end of the treatment period, mice were sacrificed, and both of their lenses were collected. The formation of a cataract was induced using H2O2, and the protein carbonyl concentration within the lens was analyzed. The vitamin C group had the lowest mean carbonyl concentration of all of the treatment groups (439 ± 155 nmol/mg), while the control group had the highest (933 ± 1117 nmol/mg). The cataracts tended to be less severe in those two groups than those from the vitamin E and the combination group which suggests that vitamin C may be a more effective antioxidant in the lens. This study provides insight into possible treatments can be prescribed to help protect the lens from the formation of a cataract.

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Aulicino, Jessica

Interactions Between Haemophilus ducreyi and Bacteria Found in the Male Urogenital Normal Flora

Date: Spring 2017
Major(s): Biology
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.

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Avolio, Theodore

Creating the fbiA-fbiB- Double Null Mutant in Dictyostelium discoideum

Date: Spring 2017
Major(s): Biology
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.

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Bacharach, Dana

The Effects of Omega-3 Fatty Acid and Exercise on Olfaction and Memory on Alzheimer’s Disease In Mice

Date: Spring 2017
Major(s): Biology
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.

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Beaty, Sierra

Growth of Haemophilus ducreyi in the Presence of the Male Normal Flora Corynebacterium glucuronolyticum and Mycobacterium smegmatis

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Rebecca Dawson

Abstract:

The ratio of the normal flora to the bacterium Haemophilus ducreyi, the causative agent of the STD chancroid, is highly unexplored. Chancroid, being prevalent in many resource-poor areas and in regions of the world where commercial sex work is also highly prevalent, is often unnoticed or misdiagnosed. It is evident that males are at higher risk of contracting the disease than females are. There are several possible reasons for this uneven ratio, one of which being the difference in the composition of the normal flora between males and females. The male normal flora may promote the growth of H. ducreyi, causing males to progress to more severe stages of the disease, resulting in them seeking medical attention more often than females. This may contribute to the difference in gender prevalence to the disease. Therefore, to explore this possibility, H. ducreyi was individually co-cultured with two bacteria that are common in the composition of the male normal flora, Mycobacterium smegmatis and Corynebacterium glucuronolyticum, in proposed 1:1 and 1:10 ratios of H. ducreyi to the normal flora bacteria. H. ducreyi was co-cultured with these bacteria in differing ratios to determine if the ratio of normal flora to the pathogenic agent had an influence on the growth of H. ducreyi. Overall, H. ducreyi had 0% survival when co-cultured with C. glucuronolyticum and, on average, had a 10,230% survival when co-cultured with M. smegmatis. These data contradict existing literature. However, the results regarding M. smegmatis support the idea that the normal flora present in males is a possible reason for the sex bias seen in the diagnosis of chancroid. The results obtained from co-culturing H. ducreyi with C. glucuronolyticum goes against this idea of differences in normal flora between the sexes results in males contracting chancroid more frequently. Based on the data collected during this study, it is difficult to determine if the male normal flora plays a role in chancroid being more prevalent in males than in females and, therefore, more research needs to be conducted to confirm this.

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Bell, Emilie

Effects of Pseudomonas fluorescens-produced antibiotic 2,4-Diacetylphloroglucinol on Chestnut Blight fungus Cryphonectria parasitica

Date: 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.

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Berry, Joanna

The effects of barriers and brown (Salmo trutta) on fish communities in northwestern Pennsylvania

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Scott Wissinger, Dr. Casey Bradshaw-Wilson

Abstract:

Native fish communities are threatened by competition and predation by invasive species as well as climate change. In North America, invasive brown trout (Salmo trutta) introduced for sport fishing can alter fish community by reducing fish diversity of vulnerable prey species. Brown trout have difficulties passing beaver (Castor canadensis) dams and other barriers such as road culverts, whereas native brook trout (Salvelinus fontinalis) use side channels to pass dams and can better negotiate these barriers. If these barriers are able to block upstream movement of brown trout, the upstream areas of the stream would act as protected refuges for native fish species, including brook trout. Therefore, I hypothesized greater fish diversity upstream compared to downstream in the presence of barriers. To test this, I conducted fish community surveys by electrofishing 10 paired sites above and below barriers to compare the fish community assemblage and the presence/absence of brook and brown trout. Invasive nonnative brown trout presence had unique effects on the fish community that the native brook trout did not: brown trout reduced the number of fish species as well as cyprinid number. When brown trout were prevented from reaching upstream areas by barriers, the stream continuum of decline in species richness reversed. Taking advantage of barriers when creating management plans will preserve the integrity of upstream fish communities.

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Billet, Logan

Temporal and interspecific variation of the amphibian chytrid fungus Batrachochytrium dendrobatidis in northwest Pennsylvania

Date: Spring 2017
Major(s): Biology
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.

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Boleratz, Kayla

Vertebrate hormones in insects: Effects of Beta-Estradiol on mating, pre-oviposition time, fecundity, and fertility in the female ring-legged earwig, Euborellia annulipes

Date: Spring 2017
Major(s): Biology
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.

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Bullis, Jessica

Effects of Detritivores on Detritus Breakdown in Wetlands: Do Detritivores Matter?

Date: Spring 2017
Major(s): Biology
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.

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Campbell, Kaitlyn

Effects of the black spot disease parasite, Uvulifer amblopliti, on the behavior of blacknose dace

Date: Spring 2017
Major(s): Biology
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.

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Carver , KayLynn

The Benefit of Resveratrol and Quercetin Co-treatments in Canine Osteosarcoma

Date: Spring 2017
Major(s): Biology
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.

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Choi, Jeannie

Differentiation of Cat Littermates by Means of Mitochondrial Control Region Sequencing

Date: Spring 2017
Major(s): Biology
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.

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Chung, Paul

Apoptotic Gene Expression of the AP-1 Transcription Factor in IRBP -/- Mice

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Christine Donmoyer, Dr. Margaret Nelson

Abstract:

Activator Protein 1 (AP-1) is a dimeric transcription factor whose transcription rate is controlled by the Fos and Jun families. Fos and Jun families regulate structure and play a role in oncogenic transformation. In the retina, AP-1 transcription factor is stimulated by high intensity light, which induces photoreceptor apoptosis. A different mouse model, interphotoreceptor retinoid-binding protein-deficient (IRBP-/-) mice were chosen due to its early photoreceptor degeneration. This research investigated if there are comparable proteins involved in apoptosis in IRBP-/- mice as observed in the light-induced model. Expression of c-Fos, pro-apoptosis gene bax, and anti-apoptotic gene Bcl-xL were tested in IRBP-/- (n=3) and wild type (n=3) (WT) groups via quantitative polymerase chain reaction. Their retinal tissues were collected at postnatal day 25, which is near the peak of apoptosis. Tissues were homogenized and total RNA was isolated. Cycle threshold (Ct) was measured. ΔCt was calculated for each gene by subtracting the average Ct of reference gene (18S ribosomal RNA) from the average Ct of the target gene. Multivariate analysis of variance (MANOVA) was used to analyze the data. P-value was 0.096 for all genes, which indicates that there is no significant difference between IRBP-/- and WT groups. A trend was observed where c-Fos was more expressed in the IRBP-/- group than the WT group. Since p-value is >0.05, there was no difference between genes c-Fos, bax, and Bcl-xL, which suggests that apoptosis in 25-day-old IRBP-/- mice is not mediated by these genes.

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Clark, Selena

Cross-modal Human Gender Discrimination by Domestic Dogs (Canis familiaris)

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Lee Coates

Abstract:

Domestic dogs have been a part of human lives for 15,000 years. They have shared our space and have developed many abilities over time that we use to our advantage in our everyday lives. Their ability to categorize humans is something that has been recently questioned, but this topic remains under-investigated. In my experiment I tested what factors affect a dog’s ability to differentiate between human genders. By using 15 dogs, 6 male and 9 female, I looked at their ability to recognize gender in pre-recorded voices, recognize gender in pre-recorded voices that had been modified, and recognize gender when their owner is one of the people they have to choose from and the recording played is of the owner’s same gender. The subjects were split into groups dependent on their sex, their owner’s gender, and the number of people they live with. I hypothesized that female dogs, dogs with male owners, and dogs living with three or more people would be better at discriminating human gender. Female dogs showed slightly better ability to choose the correct gender (66.67%, 44.44%, 44.44%) than male dogs (50%, 16.67%, 33.33%) for all three experiments, respectively. These results, however, were not significant. There was also no significant effect on the percentage of correct choices when compared to the number of people living with the dog. Although the results were insignificant I did find that in experiment two, there was a higher probability for dogs to make the incorrect choice (Prob= 0.62) than the correct choice (Prob= 0.38) when voices had been digitally manipulated up or down to simulate the voice of the opposite gender. This suggests that the pitch of a human voice does contribute to a dog’s ability to differentiate between genders. I believe that had I had a larger sample size my results may have been significant.

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Clarke, Margaret

Are Anxiety and Depression in Offspring Caused by an Induced Immune- Response in Mothers During Pregnancy?

Date: Spring 2017
Major(s): Biology
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.

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Clogan, Kaelin

The Effect of Aquatic Surface Area on Frog Resistance to a Fungal Pathogen

Date: Spring 2017
Major(s): Biology
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.

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Cole, Sarah

Comparing bactericidal effects of sodium hypochlorite (NaOCl) solution and gel on Porphyromonas gingivalis: bacteria associated with periodontal pathogenesis.

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Catharina Coenen

Abstract:

Periodontal diseases are among the most common chronic diseases worldwide and the most severe case, periodontitis, caused by biofilm accumulation of bacterial pathogens such as Porphyromonas gingivalis, leads to deterioration of the alveolar bone and tooth loss. Sodium hypochlorite (NaOCl) is used in other procedures as an effective antiseptic, and the comparison of administration method in this study can provide insight on the treatment’s ability to be additionally utilized as a periodontal therapy. NaOCl solution was investigated against NaOCl gel to better understand the treatment options for a preferred means of periodontal therapy, in place of current antiseptics such as chlorhexidine (CHX) and Triclosan which have undesirable effects. This study utilized 2-fold serial dilution techniques of both NaOCl gel and solution (1.0% – 0.00049%) to determine their antiseptic effects on Streptococcus mutans and P. gingivalis biofilms. Minimum inhibitory concentration (MIC) assays found that the NaOCl solution had greater inhibitory effects on S. mutans than the gel (p-values < 0.0001) within 5 minutes of treatment. Meanwhile, the NaOCl treatment had no significant effect on the OD of P. gingivalis with respect to method and concentration (method p-values > 0.05). Minimal lethal concentration (MLC) assays suggest that the NaOCl solution is bactericidal to S. mutans within concentrations 1.0% – 0.0078%. Growth was observed in all dilutions of the NaOCl gel with S. mutans. MLC data for both the solution and gel with P. gingivalis are inconclusive; growth was inconsistently present in various concentrations across separate replicates. NaOCl solution would be an effective antiseptic for S. mutans bacteria, but more research is needed to determine the effects of NaOCl treatment on periodontal pathogens such as P. gingivalis, specifically.

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Collins, Sean

How Previous Stressors Affect Disease Resistance in Red-Backed Salamanders

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Matthew Venesky, Dr. Scott Wissinger

Abstract:

External climate factors influence the rate of physiological processes in ectotherms, and thus greatly influences their day to day actions. Not only does temperature affect the efficiency of their physiological processes, but it can also elevate an organism’s stress levels. With an increasingly changing climate, ectotherms are going to be put out of their optimal range for their physiology more often, causing more and more stress. Corticosterone (hereafter CORT) is a main hormone of the stress response in amphibians that may help them survive a particular situation and has been shown to have immuno-suppressing effect, when chronically elevated. My experiment examined how stress affects disease resistance, using two separate lab experiments, a control temperature group and a high temperature group, and a No CORT group and CORT group. I used the amphibian chytrid fungus, Batrachochytrium dendrobatidis (hereafter Bd), a fungal pathogen that may be responsible for many worldwide amphibian population declines. After a 10-day period the stressors were stopped, every animal was housed at the same temperature, and I exposed every animal to an infectious dose and Bd. There was no difference in mass loss during the stress period between the CORT and No CORT group, but the CORT group did lose significantly more mass than the No CORT group following the Bd exposure. The high temp group lost significantly more mass following the 10 day temperature exposure period compared to the low temp group, and the low temp group lost significantly more mass following the exposure to Bd. I found no statistically significant differences in infection abundance post treatment between the CORT/ No CORT groups and the Low Temp/High Temp groups. My results suggest that the established protocol the CORT dosing cycle I used may not cause the immediate physiological changes in metabolic rate or the immune response. My results also suggest that if an ectotherm experiences a temperature increase, that doesn’t put them out of their preferred temperature range, their physiological processes could be enhanced in the short term allowing them to be better prepared for an impending infection. Future studies that build of this one could add a sham Bd component with same treatment groups and same timeline, with an ELISA both after the stress period and post Bd exposure. In order better understand the long-term effects of stress on body condition, circulating CORT and disease resistance.

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Craft, Laura

Can Female Red-Backed Salamanders, Plethodon cinereus, use Olfactory Signaling to Determine the Presence of Batrachochytrium dendrobatidis in Potential Mates?

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Matthew Venesky, Dr. Ronald Mumme

Abstract:

When faced with the threat of disease, the allocation of resources for reproductive success creates a trade-off between reproduction and other physiological mechanisms like immune function. Therefore, the ability of females to assess the infection prevalence of potential mates may be important during courtship. In salamanders, females may use chemical signaling to assess mate quality indirectly. I explored this topic with female red-backed salamanders, Plethodon cinereus, and a fungal pathogen, Batrachochytrium dendrobatidis (Bd). Bd is implicated in the mass extinction and depletion in biodiversity of amphibians worldwide. This study investigated whether female P. cinereus were able to 1) utilize olfactory signaling to locate a potential mate and 2) assess potential mates based on infection prevalence. Females were first presented with the simultaneous choice of the bedding of an unexposed male and bedding that was absent of male pheromones. After it was shown that females preferred to spend time near male pheromones, females were then given the simultaneous choice between the bedding of an unexposed male and a male that had been exposed to Bd. It was found that females spent a significantly longer period of time on the bedding of infected males than unexposed males. These results suggest that females may not be able to utilize olfactory signaling to distinguish between uninfected and infected males. Instead, females may choose mates based on pheromone production which may be hindered by an immune response in males. Future studies may investigate the relationship between sexual signaling and immunity from the male perspective in P. cinereus.

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Cuellar, Stephanie

Vitamin C Sensitivity of Canine Osteosarcoma Cells is Not Explained by KRAS or BRAF Mutations

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ann Kleinschmidt, Chris Lundberg

Abstract:

Osteosarcoma (OSCA) once diagnosed, kills 55% of children and adolescents and 85% of domestic dogs, Canis lupus familiaris. It has been shown that colorectal cancer cells containing mutations in specific exons within either KRAS or BRAF genes are susceptible to treatment with vitamin C, however cell lines without these mutations are not. KRAS and BRAF gene mutations caused colorectal cancer to have an increase of GLUT1 transporters which makes them more susceptible to cell apoptosis with vitamin C treatment. Since vitamin C does decrease proliferation in OSCA cell line 40, it could be hypothesized that there are also mutations within either the KRAS or BRAF gene in OSCA 40. In addition, it was of interest to determine if different OSCA lines were also sensitive to vitamin C treatment, and if they were, whether they contain mutations in the KRAS or BRAF genes. For vitamin C treatment, 0 – 2.5 µM concentrations were used on both cell lines, and analysis of the effect on proliferation was determined 72 hours later. The OSCA cell line 32 was more sensitive with 0.2 µM having a significant effect on proliferation, and 0.5 µM for OSCA 40. For the DNA sequence analysis, DNA was isolated from a non-diseased dog and as well as the OSCA cell lines were used in a PCR reaction using primers to amplify the DNA corresponding to exon 2 of the KRAS gene and exon 15 of the BRAF gene. The PCR products were purified and submitted for sequencing. No mutation was found at the expected sites. Susceptibility of the two cell lines does suggest that they may have high numbers of GLUT1 transporters, however, in this case, this cannot be correlate with mutations found in either KRAS or BRAF gene.

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Danisi, Jacqueline

"Changes in Lactobacilli Probiotic Concentration After Exposure to Haemophilus ducreyi and Unknown Contaminants **(Haemophilus ducreyi needs to be italicized)**"

Date: Spring 2017
Major(s): Biology
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.

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Daugherty, Daniel

Two percent CO2 is as effective as five percent CO2 in controlling febrile seizures in the mouse model

Date: 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.

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Dillon, Morgan

Effect of Testosterone on Male Allegheny Mountain Dusky Salamander Resistance to the Amphibian Chytrid Fungus

Date: Spring 2017
Major(s): Biology
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.

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Doran, Alexandra

Fruit Size in Flowering Dogwood (Cornus florida): Effects on Avian Frugivory and Seed Dispersal

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Scott Wissinger

Abstract:

Recent changes in climate around the world have reinforced the importance of understanding fragile plant and animal interactions that occur in nature. Birds rely on fruiting plants as a source of food, and plants need birds to disperse their seeds so that they can reproduce. The purpose of this study was to determine how fruit size affected ingestion and subsequent seed regurgitation on germination rates of flowering dogwood, a common fruiting tree in northwest Pennsylvania. Seeds were collected directly from flowering dogwood fruits on trees, and regurgitated seeds were collected from underneath the same flowering dogwood trees. Seeds of both groups were stratified over the winter and germinated in the spring to see if regurgitated seeds had higher or lower germination success. This study also looked at whether birds showed a preference for larger or smaller fruits. This was done by measuring individual fruits and the seeds within them to see if the size of the seed could be an indicator of fruit size. Because a strong correlation was found between fruit and seed size, the size of regurgitated seeds could be compared to the average size of uneaten seeds. There was not a significant difference in seed size between regurgitated and uneaten fruits, indicating that frugivorous birds do not have a strong preference for large versus small seeds. None of the seeds collected from undigested fruits germinated, but two (3.8%) of the 52 regurgitated seeds did germinate. Although limited, this result suggests that ingestion and regurgitation is important for dispersal and germination of flowering dogwood seeds.

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Durant, Lauren

Preferential Mate Choice in Plethodon cinereus Based on Among-Population Variation in Chemical Cues

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Matthew Venesky

Abstract:

Vertebrates utilize chemical cues during their daily social functions, and chemical cues are believed to play a large role in choosing a mate. In salamanders, males are primarily attracted to the scents of reproductively mature females over the scents of immature females and as well as other males. The eastern red-backed salamander (Plethodon cinereus) has two organs that are used to identify these reproductive chemicals. Because pheromones can differ in populations from different areas, I tested the hypothesis that the salamander Plethodon cinereus will show a preference for the chemical cues of potential mates from their local population rather than cues of potential mates collected from more distant populations. The local females were collected from Robertson Field woods. Other female salamanders were collected from Bousson located 11.3 km from the local population, State Game Lands 47 located 51.1 km from the local population, and State Game Lands 29 located 74.3 km from Robertson. I utilized a plastic container as a testing chamber. The chamber had each side lined with the paper towels of females from two different areas. To determine the preference of the salamander, I recorded what side of the container the salamander occupied every two minutes for a full hour as well as the number of nose taps, which function in detecting chemical signals or substrates, for each side of the chamber. Males showed a significant preference for the local females over females from 51.1 km and 74.3 km away in terms of both time and nose taps, but did not significantly prefer local females over those from 11.3 km away. Although this study suggests males prefer local females to distant ones, more research needs to be done to understand this topic.

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Eckhardt, Hayley

Effects on embryo development in Oryzias latipes exposed to di-2-ethylhexyl phthalate (DEHP)

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Christopher Lundberg

Abstract:

Reproductive abilities, behavior, development, and overall health can be adversely affected by chemicals called endocrine disruptors, which interfere with hormone regulation. Among the disruptors are phthalates, chemicals used in plastics to induce flexibility. Di-2-ethylhexyl phthalate (DEHP) is one of the phthalates being used to study the potential consequences in various organisms, such as mammals and aquatic vertebrates, and invertebrates. In this study, Japanese medaka Oryzias latipes was used as the model system to explore the negative effects of di-2-ethylhexyl phthalate on the developing embryo in these fish. Adult male and female medaka were paired and embryos were collected post fertilization. Embryos were assigned to one of three groups: EtOH control, 0.1 µg/L DEHP, or 10 µg/l DEHP. The embryos were maintained in treatment conditions until hatching (6-8 days). Hatching success and hours post-fertilization (hpf) that the embryonic body, eye spots, heart, red blood cell movement, and gall bladder appeared were recorded. Additionally, the first visible heart rate and heart rate on day 6 were calculated. A decrease in the number of hatched embryos in the 0.1 µg/L DEHP occurred. Embryonic toxicity leading to mortality occurred in the unhatched embryos. Endocrine disruptors, such as herbicides and estradiol, can also decrease hatch success in exposed embryos. The decreased survival rate of DEHP-exposed embryos suggest possible threats to wildlife populations of several aquatic and mammal organisms.

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Emerson, Kyle

The Effects of Temperature Variations and Cutaneous Bacteria Layer Removal on Fungal Pathogen Resistance in Plethodon cinereus

Date: Spring 2017
Major(s): Biology
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.

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Fallon, Hannah

Transmission of Haemophilus ducreyi by Musca domestica

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Susan Rankin

Abstract:

Haemophilus ducreyi is the causative agent of the sexually transmitted disease chancroid, which is characterized by the formation of genital ulcers (GU). However, recent studies highlight the occurrence of cutaneous ulcers (CUHD) caused by the same bacteria. The transmission of CUHD is under investigation and a recent study speculates that M. domestica potentially mechanically transmits H. ducreyi. I hypothesized that most of the bacteria would be carried on the flies’ legs. Therefore, this study focuses on the bacterial presence of H. ducreyi at this site. Flies were exposed to H. ducreyi in a vial swabbed with bacteria and food containing the same bacteria. Flies were transferred to sterile vials to rest post-exposure prior to their euthanasia. Micro-dissections were conducted to remove the legs of each fly and DNA was extracted. Samples underwent PCR analysis to amplify the pal gene, which is a characteristic gene of H. ducreyi. Gel electrophoresis indicated that the pal gene was present in three of the twenty exposed fly samples. This supports the notion that the H. ducreyi has the potential to be mechanically transmitted, and that M. domestica potentially plays a significant role in the transmission.

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Favaro, Daniel

Genetic Pathway Analysis of Adolescent Idiopathic Scoliosis

Date: Spring 2017
Major(s): Biology
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.

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Finigan, Rachael

Green Frog (Lithobates clamitans) Tadpoles: Ontogenetic Shifts in Food Preference, Foraging Behavior, and their Effect on Detritus Breakdown

Date: Spring 2017
Major(s): Biology
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.

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Garlick, Callie

You can't Judge a Horse by its Color: Examining the Relationship between Horse Coat Color and Personality

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Bradley Hersh, Dr. Ronald Mumme

Abstract:

Many equestrians believe in stereotypes that link a horse’s personality to coat color, but the genetics of horse coat color can be incredibly complex. While horses can display many different colors, nearly all horses have a black, bay, or chestnut base coat color controlled by interactions between the MC1R and ASIP loci. This study aims to examine relationships between base coat color and horse personality traits to explore variation at the MC1R and ASIP loci. Multiple owners filled out a survey for 94 horses of various breeds and backgrounds to gauge personality traits. In addition, we performed novel object and handling tests to include two tests administered by a consistent individual that could be related to the owner-reported information. Horses were then genotyped at the MC1R and ASIP loci to determine base coat color. We compared base coat color to the owner survey, handling test, and novel object test and found no significant correlations between base coat color and personality. The results of this study will be useful for horse buyers and trainers when working with new horses and could be useful for breeding programs and for additional studies into pleiotropies between horse coat color and personality.

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Grace, David

Effects of Soy Infant Formula on Growth and Sexual Development in C57BL/6J Mice

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Dr. Ronald Mumme

Abstract:

The consumption of soy is becoming more widespread as soy-based products are increasingly advertised as healthy alternatives to dairy; however, these benefits have only been demonstrated adults. All soy-based products contain isoflavones, compounds that are structurally similar to estrogen, and mimic its effects in vivo. Isoflavones are hypothesized to be particularly detrimental to newborns because estrogen production has not yet begun, leaving the estrogen receptors available for isoflavone binding. Males are at a particularly high risk due to estrogen’s negative feedback on luteinizing hormone production, which in turn lowers testosterone levels. The purpose of this study was to examine the effects of soy-based formula concentrations of genistein and daidzein, the two most highly concentrated isoflavones in soy, on male and female growth and sexual development. Mice were fed from birth to weaning with a diet either mimicking the dosage (9mg/kg) of isoflavones that human infants would consume or an isoflavone-free diet. Treatment was expected to decrease the mass of the male testes and epididymides and increase body weight. Because isoflavones are estrogen mimics, testosterone levels were expected to be lower in response to the treatment. Isoflavone exposure significantly reduced the anogenital distance of both male and female mice pups. Treatment resulted in smaller epididymides, while testosterone and testis weight were unaffected by treatment. Males showed no significant changes in weight, whereas treated female pups had lower weights than did control females. These results demonstrate that isoflavones have the potential to disrupt the growth and sexual development of mice, suggesting that humans may be affected in a similar manner.

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Gribik, Zachary

Developing an eDNA System to Detect and Monitor the Spread of the Invasive Round Go(Neogobius melanostomus) in the Waterways of Northwestern Pennsylvania

Date: Spring 2017
Major(s): Biology
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.

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Griffin, Colby

Effects of Warming up with a Bat Weight on Muscle Activity during the Swing of College Baseball Players

Date: Spring 2017
Major(s): Biology
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.

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Happel, Rhet

Short-term vs. long-term effect of thermal acclimation on Desmognathus fuscus resistance to Batrachochytrium dendrobatidis infection

Date: Spring 2017
Major(s): Biology
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.

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Hawk, Nicole

The Influence of Corynebacterium jeikeium on Haemophilus ducreyi growth

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Rebecca Dawson

Abstract:

Haemophilus ducreyi is a pathogen that causes chancroid, a sexually transmitted genital ulcer disease in humans. It affects more males than females, which could be due to sex differences in susceptibility to bacterial infection. This could be due to differences in normal skin flora, such as Corynebacterium jeikeium, which commonly colonizes in the perineum of adult males. H. ducreyi and C. jeikeium are bacteria located in an area near the genitalia where other bacteria are colonized and can interact with each other through cell-cell interactions. H. ducreyi is not easily isolated, which makes diagnosis unreliable because it is based on clinical signs, rather than laboratory tests. I studied the relationship between C. jeikeium and H. ducreyi to determine whether or not it affected H. ducreyi growth, and thus, the likelihood of its progression into chancroid in males. I hypothesized that C. jeikeium would increase H. ducreyi growth. I grew the bacteria in cultures under favorable conditions using a co-culture assay. I found that H. ducreyi did not grow at all in the physical presence of C. jeikeium. Therefore, it seemed that C. jeikeium inhibited H. ducreyi growth. This could have happened because the experiment was done in vitro and C. jeikeium is an opportunistic pathogen that could interact with the host and other microbiota naturally in vivo to enhance the progression of the development of chancroid into the pustular stages in males.

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Horosko, Emily

Vitamin C Inhibits the Proliferation of Canine Osteosarcoma cell line OSCA 40

Date: Spring 2017
Major(s): Biology
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.

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Husnick, Zoe

Different doses of Batrachochytrium dendrobatidis Affect Secretion of Corticosterone in Plethodon cinereus

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Matthew Venesky, Dr. Ronald Mumme

Abstract:

A stressor is any challenge to an organism’s homeostasis. To regulate how the body responds to stress, vertebrates have a hypothalamo-pituitary adrenal (HPA) axis which release glucocorticoid (GC) hormones. Vertebrates respond to various stressors by releasing corticosterone (CORT) which is the main GC hormone. Factors such as physiological changes, environmental changes, and infectious diseases affect the body’s amount of stress. Batrachochytrium dendrobatidis (Bd) is a parasitic fungus that causes the disease chytridiomycosis, infecting amphibians worldwide. Previous research has not found a connection between dosages of Bd and CORT secretion. Within my experiment, I predicted the high treatment group will have the highest infection load, followed by the low treatment group and control will not have any infection present. My hypothesis was, as Bd dosage increases, the more secretion of CORT will be present from each salamander. I exposed Red-backed salamanders (Plethodon cinereus) with different doses of Bd and observed the amount of CORT secreted. Salamanders were divided into 3 treatment groups: a low dose of Bd (1 x 10^7 zoospores), a high dose of Bd (2 x 10^7 zoospores), and a control group that was not given Bd. After applying the above treatments, I analyzed CORT secretion using a water-borne assay enzyme linked immunosorbent assay (ELISA) kit. I then analyzed Bd prevalence and Bd infection intensity within exposed animals using quantitative polymerase chain reaction (qPCR). As predicted, the results showed the high treatment group had the highest infection load. Additionally, there was a general trend of the low treatment group released the most amount of CORT and the high treatment group released the least amount of CORT. While this experiment did not find the relationship between stress hormones and disease it did, however, add to the knowledge on the impact this infection has on amphibians. Future studies could determine if the cause of CORT secretion is species specific, disease oriented, or an outside factor of stress.

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Kalamasz, Kayla

Effects of DEHP on Male Earwig Seminal Vesicle Size and Pheromone Reception

Date: Spring 2017 2017
Major(s): Biology
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.

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Kelly, Leah

The Female Flora: Inhibition of Haemophilus ducreyi and Gardnerella vaginalis Growth by Presence of Vaginal Lactobacillus

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Margaret Nelson

Abstract:

Chancroid is a sexually-transmitted ulcerative disease caused by Haemophilus ducreyi, a human-specific pathogen that has been found to also facilitate other STDs such as HIV. Studies have found that females have a significantly lower natural infection rate than males. This could be due to differences in the natural flora between the two sexes, specifically because of the natural defense mechanisms found in the female natural flora. Lactobacillus maintains adequate vaginal health in women through inhibiting pathogenic bacteria and maintaining the overall low pH of the vagina. Conversely, Gardnerella vaginalis, another bacterium found in the female microflora, has been found to have opposite effects as its proliferation results in female-specific diseases such as Bacterial Vaginosis (BV). BV, like chancroid, facilitates the transmission of STDs.  Understanding bacterial interactions between naturally occurring bacteria in female flora and H. ducreyi was my experimental aim through this study. Two Lactobacillus vaginalis strains (08&11) and Gardnerella vaginalis were both individually co-cultured with Haemophilus ducreyi and with one another to assess the potential effects on the growth of each bacteria. In a two-way co-culture between L. vaginalis (08&11) and H. ducreyi, the growth of H. ducreyi was significantly decreased (p<0.0001), and L. vaginalis (08 & 11) growth was not significantly affected (p=0.5693, p=1.0, respectively). In a two-way co-culture between G. vaginalis and H. ducreyi, neither species showed a statistically significant change in growth (p=0.9987, p=0.7953, respectively). G. vaginalis significantly decreased in the presence of L. vaginalis 11 (p=0.0242). H. ducreyi growth showed a statistically significant decrease both the three-way co-cultures (p<0.0001) containing G. vaginalis and either strain of L. vaginalis (08/11), which is consistent with the hypothesis I made that L. vaginalis would inhibit the potential promoter effects that G. vaginalis could have on H. ducreyi growth. The inhibitory effects that L. vaginalis has on the two pathogenic bacteria, H. ducreyi and G. vaginalis, could be applicable to developing an easily accessible probiotic geared towards a more preventative measure of maintaining adequate vaginal health not only in resource-poor areas, but for individuals with reoccurring cases of BV.

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Kelly-DeMello, Justine

The Effects of 17β-Estradiol on Neurogenesis in Crayfish Procambarus clarkii

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Lauren French, Dr. Christine Donmoyer

Abstract:

Neurogenesis is the process by which new neurons are formed continuously in various regions of the brain and the ability of those neurons to survive to maturity. This process was believed to only occur at a young age; however, research suggests this process continues in adult brains. Numerous factors, such as environmental stimulation, serotonin, and hormones have been found to enhance neurogenesis. Estrogen has been found to increase neural plasticity, cell proliferation, and cell survival in various models. This experimental focused primarily on the effect of 17ß-estradiol on neurogenesis in Procambarus clarkii. Crayfish were injected with 5-bromo-2-deoxyuridine (BrdU) to label new neurons, with the experiment crayfish injected with 17ß-estradiol (0.5 g estradiol / 0.4 mL of peanut oil) and the control crayfish were injected with peanut oil (0.4 mL of peanut oil). After 7 days, crayfish were sacrificed and dissected to extract their brains for processing. Finally, a series of immunocytochemistry staining was used on the brains, and were mounted. Fluorescent microscopy was used to determine amount of neurogenesis between the two different groups. Image J software determined Integrated Density Units (IDUs) to measure amount of fluorescence. After running a two-factorial ANOVA, it was found that 17ß-estradiol had a statistical effect on the amount of fluorescence, with a higher amount of neurogenesis compared to the control group. There was no statistical effect of the sexes, and the sexes did not differ in the amount of IDUs. Lastly, there was no significant interaction between sex and 17ß-estradiol. 17ß-estradiol did not affect one sex differently than it did the other sex. Future experiments could potentially focus on various concentrations of 17ß-estradiol to further analyze the neuroprotective effects of estradiol.

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Kinnamon, Benjamin

Evidence for the Existence of Genital Sex Pheromones in Ixodes scapularis

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Dr. Margaret Nelson

Abstract:

With confirmed cases of Lyme disease in Pennsylvania at historical highs, thoroughly understanding the mechanisms that regulate mating behavior in the vector Ixodes scapularis (deer tick) is crucial for developing population control strategies. Pheromones responsible for mating behavior in metastriate ticks have been identified: attractant sex pheromones, mounting sex pheromones, and genital sex pheromones. In contrast, little is known about the existence or identities of pheromones of the prostriate ticks, to which I. scapularis belongs. The aim of this study was to provide evidence for the existence of genital sex pheromones in I. scapularis. The behavior associated with detection of genital sex pheromones, genital probing of the female by the male, was prevented through blocking of the female genital aperture. Spermatophore formation was eliminated in treatment groups: no males formed spermatophores. These findings support the hypothesis that genital sex pheromones do exist and male I. scapularis rely on their detection to complete copulation. Sex pheromones have been identified in other tick species and utilized in combination with pesticides to increase efficacy. Further experimentation should attempt to confirm and identify I. scapularis pheromones as they could prove invaluable in limiting population growth and ultimately the spread of Lyme disease.

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Klein, Nichole

Vinclozolin-Induced Endocrine Disruption and Epigenetic Manipulation in Ring-Legged Earwigs (Euborellia annulipes)

Date: Spring 2017
Major(s): Biology
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.

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Krainz, Leah

Comparison of heat shock transcription factor mRNA sequences and expression in Brassica rapa and Arabidopsis thaliana

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ann Kleinschmidt, Dr. Tricia Humphreys

Abstract:

Heat shock transcription factors (HSFs) are one of the main components of the plant response to and increased tolerance of heat stress. As the global average daily temperatures continue to increase, a robust understanding of the heat shock response will assist in understanding which genes may provide crop plants with the greatest ability to adapt. The goal of this investigation was to compare protein and genomic sequences as well as mRNA levels under control and heat shock conditions of several Arabidopsis thaliana and Brassica rapa HSFs. The A. thaliana genome has been sequenced and thoroughly studied. It is known to contain 21 HSF genes. Brassica rapa, a lesser studied but more economically significant organism, is thought to contain at least 30 HSFs. It is a relative of A. thaliana that underwent a whole genome triplication event. Such an event is interesting because it is an opportunity for different, and perhaps more advantageous, genes to arise through subfunctionalization and neofunctionalization. The expression of these HSFs under heat stress when compared to orthologs and ohnologs has not been performed. A. thaliana HSFs of interest were selected based upon known levels of mRNA expression under control and heat shock and the B. rapa HSFs that were selected correspond to these. Due to the time frame of this project, only a subset of these genes could be investigated. Collectively, the HSFs were analyzed for sequence conservation and relative levels of mRNA expression. Genomic, cDNA, and CDS sequences of 11 A. thaliana and B. rapa HSFs were compared to examine their phylogeny. The HSF mRNA levels in both A. thaliana and B. rapa were measured using RT- qPCR. Under heat stress, two of the B. rapa HSFs were significantly different from their A. thaliana orthologs; one of which is correlated to its amino acid phylogeny. This suggests that these ohnologs have may have undergone subfunctionalization in the course of B. rapa’s evolution.

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Krasa, Felicia

The detection of the amphibian fungal pathogen Batrachochytrium dendrobaditis in a population of Cryptobranchus alleganiensis, the Eastern Hellbender, in a Pennsylvania Creek

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Matthew Venesky, Christopher Lundberg

Abstract:

Pathogens are affected by ecological factors such as changes in temperature, and host traits such as gender and life stages. As pathogens become more virulent and host defense diminish, hosts begin to disappear. Amphibians, which are a common host for a novel fungal pathogen, play an important role in the ecosystem. For the last couple decades, amphibians have been disappearing at alarming rates, which has started to negatively affect such ecosystem. Batrachochytrium dendrobatidis (hereafter “Bd”), an emerging infectious disease, has been one of the main causes of this recent extinction epidemic. Some species of amphibians are more susceptible than others to this fungal pathogen, but little is currently known about the prevalence and resistance to Bd in a species of fully aquatic salamander, Cryptobranchus alleganiensis, the Eastern Hellbender. For swab collection, these animals were captured from a local creek and measured for length and had sex and scarring documented for the identification of recaptured individuals. Swabs were used to test the abundance of the pathogenic fungi through DNA extraction in a 1:10 dilution and ran using quantitative PCR. Swabs collected were compared to swabs taken and run from previous years of a long-term dataset. Using data collected during the project along with previous data collected by other researchers, prevalence rates corresponded closely with the predicted temperature range that is optimal for Bd. Sex and life stage did not have any significant correlation to the probability of infection. The length of the hellbender was independent of infection prevalence. The recapture rate has increased as years have gone on, which is indicative of the animals living year to year. Future studies should continue to research the amount of Bd on the animals and how that changes over time and with different temperatures of the water and air, as well as to investigate the population numbers at the creek in order to determine whether the population is growing or declining.

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Landowski, Allison

Early Sport Specialization as a Risk Factor for Self-Reported Athletic Chronic Injuries in the Allegheny College Varsity Athletic Department: A Cross-Sectional Study

Date: Spring 2017
Major(s): Biology
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.

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Lange, Carissa

Diurnal temperature variation hinders an amphibian host's ability to clear the fungal pathogen, Batrachochytrium dendrobatidis

Date: Spring 2018
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Matthew Venesky, Dr. Beth Choate

Abstract:

Increases in global temperatures can significantly impact disease dynamics by influencing pathogen virulence, rates of pathogen transmission, and host susceptibility. As average global temperatures increase, temperature variation on annual or seasonal time scales also increases. This increased variation in temperatures has recently been associated with more frequent and severe disease outbreaks; however, few studies have explored how variation along smaller time scales (e.g., diurnal variation) might affect disease dynamics. To fill this gap in the literature, I focused on the influence of diurnal temperature variation on Batrachochytrium dendrobatidis (Bd) infection in red-backed salamanders (Plethodon cinereus). I housed salamanders in one of three constant temperatures (18°C, 23.5°C, 29°C) or in a diurnal temperature condition (29°C day, 18°C night, average of 23.5°C). After a two-week acclimation to these temperature regimes, I exposed salamanders to Bd or a control treatment. I hypothesized that the diurnal temperature group would have the highest prevalence and abundance of Bd. Additionally, because other studies have shown that Bd thrives at cooler temperatures, I predicted that the cool temperature group (18°C) would have higher infection prevalence and abundance than the intermediate (23.5°C) and warm (29°C) temperature groups. Although the diurnal temperature group did have the highest infection prevalence, the warm temperature group experienced 60% mortality and was the only other temperature group to test positive for Bd. Thus, these results suggest that increasing global temperatures could result in increased mortality among amphibian populations, and that diurnal temperature variability may be hindering a host’s ability to clear infection. This study helps provide a better understanding of how future climatic conditions may affect disease outbreak, and it emphasizes the importance of focusing specifically on the role of diurnal temperature variability.

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Lattin, Chloe

Influence of Polyamines on Haemophilus ducreyi Growth

Date: Spring 2017
Major(s): Biology
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.

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Leja, Liana

Separate vs. combined effects of snails, tadpoles, amphipods, and caddisflies on detritus decomposition in wetlands

Date: Spring 2017
Major(s): Biology
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.

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Lynn, David

Streptococcus mutans Biofilm and Growth Inhibition by Garlic Extract in the Presence of Lactic Acid-Producing Bacteria and Starch

Date: Spring 2017
Major(s): Biology
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.

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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

Date: Spring 2017
Major(s): Biology
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.

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Mamula, Olivia

Effects of LCD light exposure during the dark phase on learning and memory in mice

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Lee Coates

Abstract:

Circadian rhythms have been linked to many biological processes including sleep-wake behaviors, eating habits, hormone secretion, cellular function, metabolism, and others. Similarly, healthy sleeping habits have been linked to cognition and successful memory consolidation. With the explosion of nighttime light both in the environments we live in and phone and computer usage, it has been increasingly difficult for circadian rhythms to regulate themselves. LCD screens and blue-shifted light have been shown to negatively impact circadian rhythms and the processes they regulate. Mice that were exposed to LCD computer screens at inappropriate times during their light-dark cycle were tested in a Morris Water maze to see if this exposure affected their ability to learn and remember spatial information. Three groups were tested: a control group, a learning group, and a memory group. Control mice went through the training and testing without any LCD exposure at all. Mice in the learning group were exposed during the training phase of the maze and the memory group was exposed during the rest phase in between the training and testing phases. Mice in the learning group showed slower learning in the maze based on their average time spent completing the maze every day for 6 days. After three days of rest, the control group was minorly affected while the memory group had a slight decline in performance. The learning group seemed to be the most affected of the three groups. Although the results were not statistically significant, they suggest that inappropriate LCD exposure during the dark cycle could have negative consequences on learning and memory.

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Massart, Taylor

Genetic analysis of domestic cat mitochondrial DNA sample from Germany for forensic database use

Date: Spring 2017
Major(s): Biology
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.

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Mattwig, Melissa

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.

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McDermott, Mollie

Effects of exogenous testosterone on pregnant mice, their maternal care, and their offspring

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Dr. Lee Coates

Abstract:

Testosterone propionate is a known anabolic steroid that has been shown to cause negative side effects in both sexes. This study’s main goal is to support existing literature on the physical effects of testosterone propionate on pregnant C57 mice, their maternal abilities post-partum and the morphology of their offspring. Fifteen female mice were broken in to three equal groups. Two groups were treated with 100 µg/kg/bw and 10 µg/kg/bw of testosterone propionate and control group was treated with acetone, administered on chocolate pellets starting around day 5 of gestation continuing 10 days post-partum. After gestation and 10 days of observation, litters were sacrificed using CO2, anogenital distance was measured and blood was collected. Litter size and male anogenital distance were all affected in the 100 µg/kg/bw group. Female anogenital length, and activity in the open field test were affected by the 10 µg/kg/bw group. Mother’s weight gain, pup weight at sacrifice, and nervous grooming were significant in both treated groups. Overall testosterone propionate showed significant effects on gestation, post-partum behavior and pup morphology in C57 mice.

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McDowell, Kevin

Effects of Chronic Stress During Middle Childhood on Brain Development

Date: Spring 2018
Major(s): Biology, Psychology
Thesis Committee: Dr. Christine Donmoyer, Dr. Rod Clark

Abstract:

Many people suffer from behavioral disorders ranging from having mild
Attention Deficit Disorder that produces minor impairments, to having
severe Post Traumatic Stress Disorder that induces crippling panic attacks.
The regions of the brain primarily associated with behavioral disorders are
the amygdala and hippocampus. This study aimed to determine whether
chronic stress during middle childhood would cause these areas to develop
abnormally. Brain sections were collected from both rats developing
normally and rats that experienced chronic stress throughout weeks 3-8 of
their lives to measure the size of the amygdala and hippocampus. Stressed
rats were placed in 2-inch PVC pipes for 1 hour per day for the 5 weeks
equivalent to middle childhood. The results of this experiment showed
significant differences in size of the amygdala (p&lt;.001) and hippocampus
(p=.004) between the control and chronically stressed groups. This novel
study and its findings may advance our knowledge in the developmental
process of behavioral disorders.

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Meehan, Madison

Inhibition of Proliferation in Canine Osteosarcoma Cell Line 40 by Resveratrol is Correlated with an Increase in the Level of Long Noncoding RNA MALAT1

Date: Spring 2017
Major(s): Biology
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.

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Micheal, Hunegaw

Effects of metanotal gland feeding on male-male fighting outcomes in black-horned tree crickets (Oecanthus nigricornis)

Date: Spring 2017
Major(s): Biology
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.

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Nagael, James

The Influence of Batrachochytrium dendrobatidis on the Metabolic Function of Plethodon cinereus and Notophthalmus viridescens

Date: Spring 2017
Major(s): Biology
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.

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Nelson, Alyssa

The Effects of Imidacloprid and Atrazine on Nest Recognition in the Ring-legged Earwig, Euborellia annulipes

Date: Spring 2017
Major(s): Biology
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.

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Nguyen, Jasmine

Prenatal and Neonatal Exposure to Nicotine and Caffeine Results in an Attenuation in the Respiratory Response to CO2 in Mice: a possible link to SIDS

Date: Spring 2017
Major(s): Biology
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 .

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Nolte, Alex

Assessment of Genetic Adaptation of the α-Amylase Gene in Pymatuning Lake Cyprinus carpio as a Result of Human Induced Diet Change

Date: Spring 2017
Major(s): Biology
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.

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Orr, Kayla

Treating the Ischemic Penumbra with Propentofylline and Minocycline

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Jeffrey Cross, Dr. Lauren French

Abstract:

Strokes are responsible for the deaths of over 130,000 people in the United States alone, making them the fifth leading cause of death for Americans. Recent studies have shown evidence of neurogenesis occurring after an ischemic injury in response to neuroinflammation; however, little research has been done to determine if facilitating new neuron proliferation would be a viable treatment option for stroke sufferers. Propentofylline, a xanthine derivative, and minocycline, a tetracycline derivative, both have been shown to hold neuroprotective properties. The present study was an attempt to determine if these drugs could be useful in creating a more suitable environment for neurogenesis while limiting the damage caused by ischemia. For this experiment, a distal middle cerebral artery occlusion (MCAO) was used to induce a focal ischemic stroke in male Sprague Dawley rats. Propentofylline (12.5mg/kg) and minocycline (25 mg/kg) were administered on day 1 and days 1, 4, and 7, respectively. Minocycline given alone was effective in limiting unilateral neglect of the left side while reducing the area of infarct by 130%. Propentofylline given alone helped maintain balance, coordination, motor function, and right ventricular size while reducing the area of infarct by 160%. When administered together, propentofylline and minocycline preserved balance, coordination, bilateral motor function, and right ventricular size while reducing the area of infarct by 350%. In addition, although it could not be statistically analyzed, rats treated with propentofylline and minocycline appeared to have more neurogenesis at the infarct site compared to the controls.

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Pariyar, Keva

Energetic Trade-offs between Reproduction and Infection Intensity in Female Plethodon cinereus

Date: Spring 2017
Major(s): Biology
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.

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Pearson, Chelsea

The Effect of Dog Appeasing Pheromone Combined with Exercise on Anxiety Levels of Dogs (Canis lupus familiaris) Boarded at Kennels

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Tricia Humphreys

Abstract:

Dogs, like humans, are able to exhibit signs of anxiety, especially when placed in a stressful environment. A common source of anxiety arises when dogs are left in kennels. Dog appeasing pheromone (DAP) is known to reduce anxious behaviors, calming dogs in taxing situations. I examined the interacting effects of the duration of DAP exposure and regular exercise on anxious behaviors shown by dogs temporarily held in kennels. Two buildings at Brizes Kennel in Elizabeth, Pennsylvania, were randomly assigned either two working pheromone diffusers, or two nonfunctioning control diffusers. Anxiety was examined through three tests: separated neutral stranger test, separated friendly stranger test, and full-contact friendly stranger test. Anxious behavior decreased throughout the dog’s duration of stay at the kennel regardless of treatment. Neither exercise treatment nor pheromone treatment had significant effects on anxious behavior; however, there was an interesting trend suggesting that females had a stronger response to the pheromone than the males. Behavioral data appears to show high between-subject variation, and therefore, other measures of anxiety may provide more information on the effects of DAP coupled with exercise.

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Pellegrini, Laura

Resistance of *Pseudomonas aeruginosa* environmental isolates from college bathrooms to triclosan

Date: Spring 2017
Major(s): Biology
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.

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Petro, Mary

The Roles of Epidetrital Biofilms and Nutrient Regeneration from Green Frog (Lithobates clamitans) Tadpole Foraging on Detritus Decomposition

Date: Spring 2017
Major(s): Biology
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.

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Recke, Autumn

Effects of Triclosan on DNA Integrity and Oxidative Stress of Male Xenopus laevis Sperm

Date: Spring 2017
Major(s): Biology
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.

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Reed, Julianne

The Effects of Bisphenol A on Adult C57BL/6J Male Mice Fertility

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Christopher Lundberg

Abstract:

Bisphenol A is an estrogen mimic and endocrine disruptor that affects fertility and reproductive health in multiple living organisms, and could harm human fertility. It is one of the most commonly produced compounds in the world, and has a widespread distribution.  This research utilized 9-week-old male C57BL/6J mice, with 6 mice per group: (i) vehicle control group (20 µg/kg of body weight), (ii) low dose of BPA (20 µg/kg of body weight), (iii) high dose of BPA (200 µg/kg of body weight) for 5 weeks. The treatments were administered daily via chocolate pellets. It was hypothesized that testis weight and sperm count would decrease and the percentage of sperm abnormalities would increase with treatment groups and the effects would not be dose dependent. BPA had no effect on testis weight and sperm count, though there was a slight downward trend for testis weight. However, BPA did significantly increase the percentage of sperm abnormalities in treatment groups with no difference between the doses.

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Rodrigues, Megan

Genetic Analysis of Cytochrome b and Cytochrome c Oxidase Subunit III Genes of Cytauxzoon felis in Domestic Cats (Felis catus) from Georgia

Date: Spring 2017
Major(s): Biology
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.

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Rollin, Victoria

Effect of temperature on Batrachochytrium dendrobatidis growth in culture

Date: Spring 2017
Major(s): Biology
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.

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Rosswog, Anna

Patterns of Brook Trout (Salvelinus fontinalis) Distribution in Northwest Pennsylvania: a GIS Analysis

Date: 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.

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Ruszczyk, Melissa

Serial Sonification of Chaoborus Behavior in Response to Daphnia Size: The Intricacies of the Predator-Prey Relationship

Date: 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.

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Rzodkiewicz, Lacey

Anatoxin-a Fails to Show Allelopathic Activity in the Presence of Cyanobacteria or Green Algae

Date: 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.

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Schuver, Veronica

Cataract prevention in bovine lens: the effects of vitamin E and astaxanthin on protein oxidation

Date: Spring 2017
Major(s): Biology
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.

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Sheppeck, Alexandra

The Inhibitory Effect of Bacteria of Circumcised and Uncircumcised Males on the Growth of Haemophilus ducreyi

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Tricia Humphreys, Dr. Matthew Venesky

Abstract:

Male circumcision can greatly reduce the risk of contracting sexually transmitted infections. This is most likely due to the physical changes that arise from the circumcision surgery, specifically the change to the urogenital microbiome. Microbiomes have been found to greatly reduce the pathogenicity of bacteria and viruses, and may be the driving factor behind the decreased rate of infection in males that are circumcised. The purpose of this experiment was to determine if bacteria present in the microbiome affects the growth of a sexually transmitted infection. To a larger extent, this can determine if the effect that circumcision has on the microbiome leads to the decrease in the pathogenicity of sexually transmitted infections. By co-culturing the bacteria which causes the sexually transmitted infection chancroid, Haemophilus ducreyi, with bacteria that are found in circumcised or uncircumcised males, the growth patterns of H. ducreyi were recorded. I found that H. ducreyi growth was inhibited in co-cultures by all bacteria, except for Corynebacterium diphtheriae, where H. ducreyi exhibited minimal growth. H. ducreyi is not affected by the microbiome of the penis, suggesting that there are other circumcision-dependent factors which affect the propagation of sexually transmitted infections from one host to another.

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Shipe, David

Influence of Tree Species and Soil Properties on Maco-Invertebrate Community Diversity

Date: Spring 2018
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Scott Wissinger, Dr. Beth Choate

Abstract:

Trees are the keystone species and ecosystem engineers of forest ecosystems, often manipulating and cultivating the biotic communities that reside within the forest. Forest soils are often indicators of overall forest health and diversity. This study aimed to determine if tree species and/or soil properties directly influence the local soil macro-invertebrate community diversity adjacent to trees. Using soil cores and Berlese funnel analysis, this study found correlations between aspect, tree species, and invertebrate diversity. These findings are supported by experimental evidence from other forests around the world and could be used as a catalyst for additional research regarding mixed hardwood forests of Northeastern North America and as a resource for managers and policy makers in the region.

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Sortino, Onalee

The effects of nicotine withdrawal on the development of a ventilatory response to CO2 in neonatal mice: A possible link to SIDS

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Lee Coates, Dr. Susan Rankin

Abstract:

Sudden Infant Death Syndrome (SIDS) is the leading cause of infant death in the United States. Though the exact causes of SIDS are unknown, prenatal nicotine exposure during the critical developmental period of one month to one year of age can render an infant vulnerable to SIDS by causing developmental abnormalities in the brainstem. The brainstem is responsible for many autonomic functions, including the control of breathing. This study tested the effects of nicotine and nicotine withdrawal on B6 mouse pups when exposed to hypercapnia during neonatal development. Results from this study may be useful to model an infant exposed to nicotine prenatally, but formula fed or given up for adoption after birth and forced to suffer the effects of withdrawal. Three groups were used for this study: a control group, a group that received 3mg/kg/day of nicotine tartrate prenatally only (NW), and a group that received 3mg/kg/day of nicotine tartrate both prenatally and postnatally (NC). It was hypothesized that both nicotine exposed groups would elicit depressed ventilatory responses to CO2 during the critical period of development, but that nicotine withdrawal would be an added stressor and further negatively affect breathing during infancy. The ventilatory responses to stepwise increases of 0-6% CO2 were recorded using a head-out plethysmograph chamber on days 1, 3, 5, 7 ,9 and 11 after birth. The results of this study showed that overall, nicotine withdrawal did not cause a significant difference in weight, tidal volume, or minute ventilation when compared to control pups. However, there were an increased number of apneas and a significantly higher breathing frequency response to CO2 in the NW group compared to the control group. Overall, these results illustrate that nicotine withdrawal could cause impairments in ventilatory responses in hypercapnic conditions and be linked to an increased risk of SIDS in an infant.

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Stengel, Jessica

Effects of acute iron overload on the testis, epididymis, and serum testosterone levels in C57BL/6J male mice

Date: Spring 2017
Major(s): Biology
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.

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Stewart, Meghan

Evolution of Predatory Methods of the muricid subfamily Ocenebrinae using a Phylogenetic Framework

Date: 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.”

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Stigall, Tyler

The effects of morphospace occupation and variation on genus survivorship through mass extinctions

Date: Spring 2017
Major(s): Biology
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.

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Stookey, Jessica

Pre-pregnancy & early pregnancy exposure to Isotretinoin (Accutane®) in Laboratory Mice Mus musculus and Birth Outcomes

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Susan Rankin, Dr. Rebecca Dawson

Abstract:

Isotretinoin, marketed as Accutane, is an oral medication which has been highly effective in the treatment of severe and persistent acne. Isotretinoin has been shown to have teratogenic effects in both human population studies and rodent models. Isotretinoin increases incidence of birth defects by almost 30%, with the most common defects being craniofacial abnormalities, limb reductions and malformations, decreased body size, and increased likelihood of miscarriage and stillbirth. In this study, experimental mice were exposed to 1.0mg/kg/day of isotretinoin for 10 days prior to mating and for the first 10 days of gestation. Observations of malformations and body size were made on pups 3 weeks after birth. Although no limb reductions or malformations were observed, there was a significant number of craniofacial abnormalities present in pups of Isotretinoin-treated mothers. These Isotretinoin-treated mothers also gave birth to smaller litters, and their pups were smaller in body weight and size. Additionally, two treated mothers died during parturition, suggesting that Isotretinoin treatment may put pregnant mothers at risk.

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Sutkowski, Paul

Epigenetic Inheritance of Temperature-Induced Variation in Tail Lengths in Mice

Date: Biology 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Bradley Hersh

Abstract:

Epigenetics is a relatively new field in biology. Epigenetics deals with the methylation of DNA in an organism leading to changes in gene expression and phenotype, regardless of what genotype may be. Epigenetic inheritance is the idea that methylation patterns and other epigenetics tags can be passed down to offspring. Rearing temperature in mice has been shown to affect their tail length in adulthood, with mice reared at cold temperatures growing shorter tails. To determine if this environmentally-induced change in tail length could be inherited epigenetically, I reared mice at two separate temperatures. One group (F1) was raised at 8°C and the other at 23°C. When sexually mature, the mice were bred and half of the resulting F2 pups were raised at the same temperature as the parents while the other half were raised at the other treatment temperature. Tail lengths and mass were measured once a week. This was to determine if the epigenetic effect of rearing temperature on tail length can be transmitted to offspring. It was found that the mother’s rearing temperature did have an effect on the tail of its offspring.

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Taylor, Rachael

Glycosuria effects on Pseudomonas aeruginosa PAO1 Biofilm Formation on Common Catheter Materials

Date: Spring 2017
Major(s): Biology
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.

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Thiessen, Jessie

Estrogen Fluctuations in the Female Menstrual Cycle

Date: Spring 2017
Major(s): Biology
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.

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Thomas, Samuel

Developing an Ethical and Effective Murine Model for Type 1 Diabetes Mellitus-Induced Cataract via Single Dose of Streptozotocin

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Christine Donmoyer, Dr. Rebecca Dawson

Abstract:

Cataracts, which are characterized by cloudiness/opacification of the lens, were the leading cause of blindness in 2010. Type 1 diabetes mellitus (T1DM) is one of the most prevalent risk factors for cataracts. To test preventative treatments for T1DM-induced cataracts, a valid, ethical, and cost-effective animal model is necessary. This proposed model used a single intraperitoneal (IP) streptozotocin (STZ) injection of 85 mg/kg body weight (BW) to induce T1DM and cataracts in male C57BL mice by 3- and/or 4-weeks post-injection. Other investigators have observed mortality rates of 15-20% as a result of higher STZ dosages. This STZ dosage was selected to limit mortality from acute hypoglycemia or hyperglycemia. Groups 3W (n=4) and 4W (n=4) received STZ injections suspended in 0.1M sodium citrate buffer, while the sham control group (n=4) received an IP injection of 0.1M sodium citrate buffer. All mice were weighed daily and tail vein blood samples were obtained biweekly. At 3- (group 3W) or 4-weeks (groups 4W and sham) post-injection, lenses were dissected immediately following euthanasia and photographed under a microscope. Lens opaqueness was rated from 1-3 (1 being least opaque, and 3 most opaque) by two observers. Average change from baseline in blood glucose level for groups 3W, 4W, and sham were -1 +/- 28, -38 +/- 13, and 32 +/- 20 mg/dL, respectively. Average opaqueness for groups 3W, 4W, and sham were 1.2 +/- 0.02, 1.6 +/- 0.31, and 1.5 +/- 0.04. Using the statistical Mann-Whitney U Test, no statistical differences between opaqueness, change in BW (g), or change in blood glucose concentration were observed between the experimental groups and the sham group. Consequently, it can be concluded that T1DM was not induced by this dose. This model could be improved if either the single dosage of STZ was increased or by administering multiple doses of STZ over time.

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Tilley, Matthew

The Effects of Alachlor Exposure on Adult Female Euborellia annulipes and Resulting Offspring

Date: Spring 2017
Major(s): Biology
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.

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Vescio, Brittini

Determining tolerance to Batrachochytrium dendrobatidis in Notophthalmus viridescens newts through leukocyte analysis

Date: Spring 2017
Major(s): Biology
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.

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Ward, Kenton

Effect of Electrolyte Treatment on Batrachochytrium dendrobatidis Infected Rana pipiens

Date: Spring 2017
Major(s): Biology
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.

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Wehrer, Kathryn

The impact of temperature on rates of cannibalism in Ambystoma mexicanum

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Scott Wissinger

Abstract:

A common way that amphibians adapt to overcrowding and lack of food resources is the cannibalization of conspecifics. Cannibalism has been strongly connected to crowding and dietary restrictions, but the relationship between the prominence of cannibalism and temperature has yet to be explored. Axolotls, Ambystoma mexicanum, an aquatic salamander native to Mexico, were used to determine the impact of temperature on cannibalism with adequate food and moderate population density. This experiment examined the occurrence of the cannibalism across three temperatures: low (17°C), moderate (20°C), and high (23°C). The experiment used a density of 15 salamanders per 35L tank to induce cannibalism, and the occurrence of cannibalism was recorded across the three temperature treatments. I hypothesized that larvae exposed to the high-temperature environment would experience an increased metabolic rate resulting in a higher occurrence of cannibalism compared to the moderate and cold conditions. As expected, the high-temperature treatment experienced the most cannibalism with 15 salamanders cannibalized over 28 days. The cold and moderate-temperature treatments each experienced 7 instances of cannibalization. Although metabolic rate was not measured, the data suggests that warm-temperatures promote cannibalism in Ambystoma mexicanum.

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Weinstein, MacKenzie

Perinatal Exposure to 5-Hydroxytryptophan (5-HTP) Results in an Increased Breathing Frequency in Response to Hypercapnic Conditions in Neonatal SERT- Mice: A Possible Link to SIDS

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Lee Coates, Dr. Bradley Hersh

Abstract:

Sudden Infant Death Syndrome (SIDS) is the death of a child under the age of one for an unknown reason during sleep. According to the Triple Risk Model (TRM), three conditions must overlap for an infant to die of SIDS: critical development period (2-4 months), presence of an exogenous stressor (hypercapnia, hypoxia, upper airway infections, etc.), and an underlying systemic abnormality or vulnerability (lack of 5-HT [serotonin] in the brainstem). Wildtype mice pups exposed to increasing levels of CO2 have shown increased ventilatory responses, while mice pups lacking serotonin have shown a muted ventilatory response to increased CO2. It was hypothesized that mice lacking 5-HT who were treated with 5-hydroxytryptophan (5-HTP) would have increased ventilatory rates when exposed to CO2, similar to a wildtype response. In this study, female mice lacking the serotonin transport protein (SERT-) were treated with 58.8 ± 2.59 mg/kg/day 5-HTP via water during pregnancy and the testing days post-birth. Their pups were exposed to increasing levels of CO2 (0%, 2%, 4%, and 6%) on postnatal days 1, 3, 5, 7, 9, and 11 and the pups ventilatory responses were measured through a head out plethysmograph. Recordings were analyzed to determine frequency (ƒ) (breaths/min), tidal volume (VT) (mL/breath) and minute ventilation (VE) (mL/min) for all mice pups. This study found that SERT- mice exposed perinatally to 5-HTP exhibited increased ƒ over time compared to control mice, while there were no changes in VT or VE that reached statistical significance. Trends were seen in this study to demonstrate that 5-HTP partially rescues the muted ventilatory response in SERT- mice over the testing period of 11 days and when exposed to hypercapnic conditions, especially in heterozygous pups. Infants lacking serotonin or with malfunctioning SERT proteins in the brainstem are at an increased risk for SIDS shown by the neonatal mice displaying a decrease in ƒ and a lack of change in VT and VE in hypercapnic conditions, suggesting a delayed maturation period of the central and peripheral chemoreceptors. 5-HTP treatment therefore reduces the risk of SIDS in infants who have a reduced level of serotonin or only some functioning SERT proteins (heterozygous) in the brainstem, suggesting 5-HTP allows for earlier maturation of the central and peripheral chemoreceptors necessary to sense changes in CO2 and control ventilation.

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Wildt, Amanda

The Effects of Photoperiod on Behavior in Rana clamitans Tadpoles

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Matthew Venesky

Abstract:

Circadian rhythms have been found to play an important role in the behavior of amphibians. The timing of development of amphibian larvae and the ability to reproduce as adults can be affected by both temperature and light (Paniagua et al. 1990). Daylength and the temperature correspond to different times of year and allow amphibians to time reproduction and metamorphosis when conditions are favorable. If the day were significantly longer or shorter than average, then organisms would have more or less time to forage for food which would affect how active they are and potentially when they are choosing to be more active. It is likely that the amphibian larvae that are given the shortest daylength will be much more active than the ones that receive longer days due to the fact that they will have less time to forage for food. The green frog tadpoles in the experiment will be exposed to either 12 or 16 hours of light and their activity will be monitored. There will also be a group that will be exposed to light constantly throughout the duration of the experiment. The results of the experiment did not yield a significant difference in activity level between the 6-hour light group and the 12-hour light group. However, there was a nearly significant difference between the daylight activity levels in the 6-hour and12-hour groups, with the daylight hours being more active than the nighttime hours.

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Woods, Michelle

Effects of disease pathology on nutrient cycling in aquatic systems

Date: Spring 2018
Major(s): Biology, Environmental Science
Thesis Committee: Dr. Matthew Venesky, Dr. Scott Wissinger

Abstract:

Organisms play important roles in cycling nutrients within ecosystems, and the rate and efficiency of nutrient cycling is impacted by various factors. This can include the presence of wildlife infectious diseases as disease can affect organismal behavior and morphology thus impacting the role that those organisms play in nutrient cycling. An example is the fungal pathogen, Batrachochytrium dendrobatidis (Bd) which causes chytridiomycosis (chytrid) in tadpoles and negatively affects their jaw sheaths and labial teeth leading to abnormal feeding behaviors and reduced food consumption. This may impact how nutrients flow through ecosystems as the infection could hinder the ability of tadpoles to consume and break down detritus. This study investigated how a Bd infection in Lithobates clamitans (green frog) tadpoles impacts detrital breakdown and the concentrations of nitrogen, phosphorus, and Chlorophyll-A in aquatic ecosystems. Microcosms that included detritus, tadpoles, and periphyton tiles were created and the CPOM breakdown, FPOM generation, and the concentrations of Chlorophyll-A, NH4+, and were analyzed. I hypothesized that a Bd infection would impair the tadpoles’ ability to break down detritus and that this would decrease the concentrations of Chlorophyll-A, NH4+, and SRP. Only 2 tadpoles were confirmed to have the Bd infection, and there were no significant differences CPOM breakdown, FPOM generation, and Chlorophyll-A, NH4+ and SRP concentrations between the non-exposed and replicates, attributed to a low infection prevalence. However, the qualitative trends observed could be amplified with a higher infection prevalence indicating that Bd infection could be a powerful influence in ecosystem form and function.

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Yemc, Madison

The Effect of the Herbicide Roundup on Female Mate Choice in Guppies (Poecilia reticulata)

Date: Spring 2017
Major(s): Biology
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.

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Yerramreddy, Ananya

Determining sexual dimorphism in the cheetah (Acinonyx jubatus spp.) through cranial and dental morphology

Date: Spring 2017
Major(s): Biology
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.

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Zimmer, Harper

The effects of social partners on behavioral and physiological stress in a novel environment: Do domestic chicks (Gallus gallus domesticus) form strong social attachments?

Date: Spring 2018
Major(s): Biology
Thesis Committee: Dr. Ronald Mumme, Dr. Matthew Venesky

Abstract:

Social bonds are something that are necessary for many species. The purpose of this study is to discern if chicks (Gallus gallus domesticus) make deep social attachments to one another as opposed to simply requiring being reared with a partner. The first 2-9 days post hatching is considered a “sensitive period” where the initial imprinting of chicks can be overridden. The study involved 16 chicks paired up, to create eight couples. The eight couples were split into two groups of four. The first group of four couples remained with their same partner throughout the entire study and was labeled as the control group. The second group of four couples all switched partners on the tenth day. Behavioral data was observed and recorded daily. On the eleventh and thirteenth days all of the chicks were subjected to a novel test environment with their partners for ten minutes during which their behavior was recorded. At the end of the ten minutes blood samples were taken from the chicks. The plasma was later removed and then run through a Cayman ELISA kit to determine the corticosterone concentrations in order to evaluate the stress levels. The behavioral data suggests that chicks who remained with their original partners throughout the duration of the study showed more exploratory behavior and gave fewer distress calls than chicks in the switched group. However, levels of corticosterone were unexpectedly higher in the control group, but only on day 13. Despite the contradictory corticosterone data, my behavioral data suggests that chicks formed deep social bonds with long term rearing partners.

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