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Quantification Of Neuronal Specific Responses To Depletion Of The Nascent Polypeptide-Associated Complex In Caenorhabditis Elegans, Harrison Hall

Senior Honors Projects, 2010-2019

Cells experiencing misfolded protein stress can become debilitated and die, consistent with this stress being linked to numerous diseases. When misfolded proteins accumulate in the endoplasmic reticulum (ER), the unfolded protein response (UPR) initiates mechanisms that resolve this stress or trigger apoptosis, dependent on the severity and/or duration of the stress. The nascent polypeptide-associated complex (NAC) is a heterodimeric chaperone that mediates proper protein folding and localization during translation; depletion of the NAC promotes misfolded protein stress in the ER, resulting in the initiation of the UPR in affected cells. The relationship between the NAC and the UPR is not …

Detecting The Cold: Do Innexins Function In Cold Nociception?, Rachel Barborek

Senior Honors Projects, 2010-2019

Nociception is the perception of and response to harmful stimuli. Nociception is essential for minimizing tissue damage, but aberrant nociceptive pathways can result in chronic pain. Chronic pain in the U.S. is commonly managed with wide-acting opioids, and precisely defining the components of nociceptive pathways could uncover novel targets for pain therapies. I hypothesize that the vitally quick process of nociception would utilize electrical synapses because they transmit signals between neurons more quickly than chemical synapses do. This study, therefore, aims to uncover the potential role of the eight Drosophila melanogaster gap junction proteins, the Innexins, in cold nociception. Wild …

The One Health Initiative: The Intersection Of Human, Animal, And Environmental Health, Mary Evelyn Pearsall

Senior Honors Projects, 2010-2019

The One Health concept is a global strategy for strengthening interdisciplinary collaborations among health care for humans, animals, and the environment. The purpose of this honors capstone project is to study the One Health Initiative and create a comprehensive thesis on what the initiative is and how it is relevant to different sectors of health. An overview of prevalent zoonotic diseases will be provided including how they are transmitted and their global relevance. Case studies on zoonotic diseases will be used in which the effectivity of a One Health approach can be analyzed. In addition, relevant sections on One Health …

Biosemiotics As An Argument For The Recontextualization Of Biological Discoveries: A Critical Analysis Of The Biosemiotic Model Of Marcello Barbieri., Augustus Morrissey Snyder

Senior Honors Projects, 2010-2019

The primary purpose of this project was to investigate and explain the philosophical approach of biosemiotics to understanding living systems in contrast to the current scientific paradigm. Secondary goals were to evaluate the potential merits and relevance of this approach to biology and to introduce such a topic for discussion to biologists in a formal academic setting. My method consisted of critical textual analysis supplemented by analogy and biological examples where appropriate. In general, contemporary biosemiotics argues for a teleologic recontextualization of biological discoveries in practice and education. This is accomplished in a sophisticated fashion through the application and modification …

Antimicrobial Activity Of Novel Cationic Amphiphiles, Melanie Kusakavitch

Senior Honors Projects, 2010-2019

This project focused on the development of amphiphiles in order to prevent hospital-acquired infections before they have a chance to enter the host, thereby reducing the need for antibiotics. The antibiotic resistance crisis of the 21st century is a dangerous epidemic with global consequences. Therefore, there is a desperate need for novel approaches in antimicrobial research. This would decrease the overall length of stay in hospitals and costs associated with such a stay. In this study, tetracationic amphiphiles with two 12-carbon chains and an aliphatic linker were studied. The MIC value of each amphiphile and strain pair was determined and …

Muscle Synergies And How They Contribute To The Movement Of The Tail During The Nociceptive Withdrawal Response In The Rat’S Tail, Hasti Izadpanah

Senior Honors Projects, 2010-2019

Noxious stimuli can evoke the nociceptive withdrawal response (NWR), which protects the affected part of the body from injury. The rat’s tail, because of the large number of joint (n=84) and muscle (n=300) degrees of freedom, may present a computational challenge to the central nervous system. Previous studies have revealed that synergies act to reduce the number of degrees of freedom across diverse movements in a variety of animals; however, there is little information in mammals on synergistic control of the tail. The long-term specific aim of this project is to test the hypothesis that during the NWR muscle synergies …

Reconstruction Of The Tail Nociceptive Withdrawal Response From Combinations Of Movement Primitives Associated With Individual Muscles In The Rat, Justin Nguyen

Senior Honors Projects, 2010-2019

Abstract

One type of involuntary movement is the nociceptive withdrawal response (NWR), in which mammals move a part of their body away from noxious, or tissue damaging, stimuli. Previous studies have evoked the limb NWR in diverse animals such as cats, frogs, and humans. However, there is minimal information on how complex movement arising from numerous muscles and joints, such as in the tail of the rat, is effectively coordinated.

The specific aim was to identify the contribution of movement from individual extrinsic muscles to the tail NWR utilizing a new technique. From previous studies, extrinsic muscles in the pelvis …

Tetrameric Structure Of Beta-Amylase 2 (Bam2) In Arabidopsis Thaliana, Lauren Elizabeth Pope

Senior Honors Projects, 2010-2019

Plants store starch during the day for use at night. This process of transitory starch degradation is mostly attributable to the β-Amylase (BAM) family, which are starch exohydrolases that cleave the penultimate α-1,4 glycosidic bonds of starch to release maltose. BAM2 was recently characterized as a catalytically active, K⁺-requiring tetramer with sigmoidal kinetics and cooperativity. All other catalytically active BAMs display Michaelis-Menten kinetics, no cooperativity, and do not require salt, making BAM2’s characteristics intriguing. Due to a lack of a crystal structure, a monomeric homology model of BAM2 was generated using I-TASSER based on a BAM5 from soybean. …

The Role Of Brain Stem 5-Ht1a And Gaba-A Receptors In The Thermoregulatory Response To Hypoxic Stress, Alexander Schmidt

Senior Honors Projects, 2010-2019

Sudden Infant Death Syndrome (SIDS) is a leading cause of infant mortality. Alterations in brainstem development of Serotonin (5HT) and γ-aminobutyric acid (GABA) are linked to its cause. The sympathetic premotor neurons located in the Nucleus of the Raphe Pallidus (NRP) in the brainstem have both 5-HT1A and GABA-A receptor subtypes that mediate protective cardiovascular responses to environmental stress. It is hypothesized that alteration in these receptors at the NRP will also modify protective thermoregulatory responses to hypoxic stress such as hypothermia. Using aseptic techniques, male and female Sprague-Dawley rats (230-385g) were instrumented with radiotelemetry probes to non-invasively measure core …

Rat Hind Limb Nociceptive Withdrawal Response To Heat And Mechanical Stimuli Depends On Initial Position Of The Paw But Not Stimulus Location, Giavanna Verdi

Senior Honors Projects, 2010-2019

Mammals rapidly withdraw their hind limb in response to noxious stimulation, which is a protective movement known as the nociceptive withdrawal response (NWR). The NWR has been previously studied in spinalized, decerebrated and anesthetized non-human and human mammals; however, there is minimal information on the NWR in intact, unanesthetized non-human mammals.

The first specific aim was to identify the factors that determine the direction and magnitude of the NWR in intact, unanesthetized rats. Based on previous studies, we hypothesized that the location of stimulation and the initial position of the paw preceding the NWR will influence the direction and magnitude …

Searching For Sex Differences In Snake Skin, Sydney E. Ashton

Senior Honors Projects, 2010-2019

The production of many secondary sexual signals, including pheromones, is controlled by sex hormone action at the sites of signal synthesis. The red-garter snake (Thamnophis sirtalis parietalis) is an ideal vertebrate for studying the interaction between steroids and sexual signals: males exclusively rely on skin-based female pheromones during courtship, and pheromone composition is augmented by treatment with sex steroids (e.g., males produce female pheromone if implanted with estrogen). But how do steroid hormones promote pheromone expression at the molecular level in snake skin? Feminizing effects of estrogens on sexual signals are known to result from activation of estrogen …

Reverse Genetic Screening Of Innexin Gap Junction Proteins In Drosophila Neurons, Shannon P. Fox

Senior Honors Projects, 2010-2019

The reflexive response and perception of pain (nociception) is an evolutionarily conserved process in animals. Pain can be a major health concern and current treatments often prove insufficient, especially in regards to chronic pain. Greater understanding of the molecular processes underlying pain sensation could lead to new and more effective treatments. The aim of this study is to investigate the molecular mechanisms of cold nociception in Drosophila melanogaster. A specific subset of peripheral sensory neurons (Class III dendritic arborization (da) neurons), are implicated in Drosophila larvae’s response to noxious cold.

Previous literature has associated a family of gap junction protein, …

Embryonic And Post-Embryonic Hoxa13 Expression In The Four-Toed Salamander, Hemidactylium Scutatum., Breanna R. Lee

Senior Honors Projects, 2010-2019

The process of somitogenesis occurs during embryological development and results in the definition of persisting axial segments. The four toed salamander, Hemidactylium scutatum, exhibits post-embryonic segmentation while most other vertebrates stop segmentation at the end of embryological development. HoxA13, a transcription factor expressed along the developing anteroposterior axis, plays a role in specifying caudal segmental identity, cell ingression into the pre-somitic mesoderm (PSM), and PSM truncation. HoxA13’s responsibilities in influencing embryological development make it an interesting candidate for involvement in post-embryonic segment addition mechanisms. This study explores the role of HoxA13 in tail segmentation in H. scutatum embryonic, larval, …

Nonlinear Dynamics Of Filaments In Free Space And Fluids, Victoria Kelley

Senior Honors Projects, 2010-2019

The purpose of this paper is to study a straight rod, held at both ends, with a known twist and tension or compression. We study the stability of this steady state when the system is dominated either by inertia or drag. In order to do this, we first replicate the work of Goriely and Tabor to look at the case with inertia, without drag. After conducting the analysis for that case, we then apply their framework to perform a linear stability analysis of a model that is without inertia, but with hydrodynamic drag. Our motivation is the study of locomotion …

Population Projection And Habitat Preference Modeling Of The Endangered James Spinymussel (Pleurobema Collina), Marisa Draper

Senior Honors Projects, 2010-2019

The James Spinymussel (Pleurobema collina) is an endangered mussel species at the top of Virginia’s conservation list. The James Spinymussel plays a critical role in the environment by filtering and cleaning stream water while providing shelter and food for macroinvertebrates; however, conservation efforts are complicated by the mussels’ burrowing behavior, camouflage, and complex life cycle. The goals of the research conducted were to estimate detection probabilities that could be used to predict species presence and facilitate field work, and to track individually marked mussels to test for habitat preferences. Using existing literature and mark-recapture field data, these goals were accomplished …

Structural Comparison Of Tonb-Dependent Receptors In Bradyrhizobium Japonicum, Allie R. Casto

Senior Honors Projects, 2010-2019

Soybean is one of the leading crops grown in the United States. Nitrogen fertilizers are widely used in soybean production to increase crop yields. An alternative to nitrogen fertilizers is the symbiotic relationship between soybean and a species of nitrogen-fixing Gram-negative soil bacteria, Bradyrhizobium japonicum. The bacterium infects the roots of the soybean, forming nodules that perform nitrogen fixation. This study involves analysis of TonB-dependent receptors, intermembrane proteins responsible for iron uptake and, in some cases, symbiosis in B. japonicum. A comparison of sequence alignments and 3D structure predictions was used to identify potential symbiosis-specific structural domains within …

Characterization Of Cell-Type Specific Responses In C. Elegans Experiencing Misfolded Protein Stress: How Do Some Cells Save Themselves While Others Die?, Courtney A. Matson, Erin N. Wallace

Senior Honors Projects, 2010-2019

To maintain viability, cells must resolve misfolded protein stress; the inability to do so often triggers cell death, most notably in neurons during neurodegenerative disease. The NAC is a highly conserved translational chaperone essential for protein folding and localization to organelles throughout the cell. In C. elegans, depletion of the NAC initiates misfolded protein stress specifically in the endoplasmic reticulum, inducing a response that upregulates the HSP-4 chaperone in an attempt to prevent cell death. This upregulation is robust but not uniform, and deficient in regions containing neurons. We are characterizing this non-uniform stress response to determine if HSP-4 upregulation …

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …