Digital Commons Network^™

Patterns Of Molecular Population Genetic And Phenotypic Variation Associated With Urbanization In The Western Black Widow Spider, Lindsay Miles

Theses and Dissertations

In urban population genetic studies, the "urban fragmentation model" predicts that urbanization acts as a barrier that isolates native populations, and can lead to reduced gene flow and increased genetic drift between populations. The “urban facilitation model” predicts urban areas act as corridors to increase dispersal among urban areas, and can lead to higher genetic diversity within and lower differentiation between urban areas.

In a review of the current literature, we found that there is no consistent signature of reduced within-population genetic diversity or increased between-population genetic differentiation. Analyses that investigate the urban barriers to gene flow also found no …

Natural And Anthropogenic Drivers Of Tree Evolutionary Dynamics, Brandon M. Lind

Theses and Dissertations

Species of trees inhabit diverse and heterogeneous environments, and often play important ecological roles in such communities. As a result of their vast ecological breadth, trees have become adapted to various environmental pressures. In this dissertation I examine various environmental factors that drive evolutionary dynamics in threePinusspecies in California and Nevada, USA. In chapter two, I assess the role of management influence of thinning, fire, and their interaction on fine-scale gene flow within fire-suppressed populations of Pinus lambertiana, a historically dominant and ecologically important member of mixed-conifer forests of the Sierra Nevada, California. Here, I find evidence …

Observations Of Trends And Successes Of Revascularization Therapy At Virginia Commonwealth University: A Retrospective Study, Richard W. Sedwick

Theses and Dissertations

The aim of this study was to determine the trends in protocol, success rates, and consistency in follow up of revascularization procedures in a controlled environment. Patients of the Virginia Commonwealth University School of Dentistry were identified who were offered revascularization therapy as a treatment option on immature permanent teeth from January 1, 2010 to May 31, 2017. A total of 77 patients and 78 teeth were evaluated for revascularization therapy. For patients accepting treatment, records were reviewed for outcome assessment and consistency of follow up. A total of 30 patients (31 teeth) were treated following revascularization protocols, with only …

Chromodomain Helicase Dna Binding Protein 1 (Chd1) Is Required For Orofacial Development In Xenopus, Brent Wyatt

Theses and Dissertations

Abnormalities affecting orofacial development are some of the most common, expensive, and devastating birth defects. Children born with such defects may experience difficulties with eating, breathing, and speech and in addition, these defects often require multiple surgeries to correct them. Therefore, it is critical to understand how the orofacial region develops in order to better treat and prevent these types of birth defects. Xenopus laevis has emerged as a strong model in which to examine orofacial development and was utilized here to investigate the cellular and molecular mechanisms underlying the complex development of the orofacial region. Retinoic acid is one …

Determining Tidal Characteristics In A Restored Tidal Wetland Using Unmanned Aerial Vehicles And Derived Data, Victor Thornton

Theses and Dissertations

Unmanned aerial vehicle (UAV) technology was used to determine tidal extent in Kimages Creek, a restored tidal wetland located in Charles City County, Virginia. A Sensefly eBee Real-Time Kinematic UAV equipped with the Sensor Optimized for Drone Applications (SODA) camera (20-megapixel RGB sensor) was flown during a single high and low tide event in Summer 2017. Collectively, over 1,300 images were captured and processed using Pix4D. Horizontal and vertical accuracy of models created using ground control points (GCP) ranged from 0.176 m to 0.363 m. The high tide elevation model was subtracted from the low tide using the ArcMap 10.5.1 …

A Laboratory Study Of Stress Reactions To Witnessing A Police Killing Of An Unarmed Black Man: Discrimination, Distress Tolerance, Ethnic Identity, And Risk-Taking, Michael A. Trujillo

Theses and Dissertations

Black individuals have been disproportionately targeted by law enforcement, most notably in shooting deaths at the hands of police, and has contributed to a general distrust of law enforcement. A rise in citizen journalism has helped document excessive use of force by police on video; however, little is known how individuals respond to viewing this type of media. A history of race-based stress is likely to contribute to an expectation of racism and may impact how individuals respond to videos of the treatment of unarmed Black men at the hands of police, with some evidence suggesting ethnic identity may moderate …

Biochemical Analysis Of Putative Rna-Binding Proteins In Porphyromonas Gingivalis, Jacob Mirpanah

Theses and Dissertations

BIOCHEMICAL ANALYSIS OF PUTATIVE RNA-BINDING PROTEINS IN PORPHYROMONAS GINGIVALIS

By Jacob Mirpanah

Bachelor of Arts in Biology, University of Virginia, 2015

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Physiology and Biophysics at Virginia Commonwealth University

Virginia Commonwealth University, 2018

Major Director: Janina P. Lewis, Ph.D., Philips Institute for Oral Health Research

RNA-Binding Proteins (RBPs) play important regulatory roles in countless cellular processes. Often via the induction of a structural change in RNA’s secondary structure, RBPs are known to modulate protein expression through post-transcriptional regulation. In Escherichia coli, such RBPs have …

The Progress On Mapping Ubiquitin Signaling Using Photocrosslinking Mono And Di-Ubiquitin Probes And Other Ubiquitin Moieties, Courtney N. Braxton

Theses and Dissertations

Ubiquitin (Ub) is a small, 76 amino acid, and post-translational modification (PTM) protein in eukaryotes. Modification of a substrate protein via the covalent attachment of the C-terminal glycine of Ub to the ε-amino group of lysine residues in a substrate is termed ubiquitination. Unlike, other PTM proteins, Ub can form polyUb chains at one or more of its seven lysine residues. (K6, K11, K27, K29, K33, K48, and K68). The consequence of these different polymerization sites is altered biological response with different polyUb linkages conferring different fates to target proteins. Unfortunately, the study of these chains have been limited by …

Glycolytic Atp Production Is Required For Innate Mast Cell Activation And Is Limited By Lactic Acid, Which Effectively Reduces Lps-Induced Cytokine Production In Mast Cells And In Vivo, Heather Caslin

Theses and Dissertations

The metabolic pathways required for adenosine triphosphate (ATP) production within the cell are well understood, however recent publications suggest that metabolic pathways are closely linked to immune cell activation and inflammatory diseases. There has been little examination of the metabolic pathways that modulate mast cell activation and the feedback regulator lactic acid. Here we examine metabolic pathways and regulation within mast cells in the context of lipopolysaccharide (LPS) and interleukin (IL-33) activation, for which there has been little to no reported studies. First, we examine the effects of lactic acid, previously considered only a by-product of glycolysis and now understood …

Evolution And Niche Specialization Of Microbial Taxa In Vaginal Infection And Pregnancy, Abigail L. Glascock

Theses and Dissertations

The vaginal microbiome plays an important role in reproductive health and pregnancy. It has coevolved with humans and has direct effects on reproductive success, rendering selective pressure more pronounced at this site. Herein, we probe coevolution of the vaginal microbiome using a systems-level approach. In Chapter 2, we examine the evolutionary trajectory of two vaginal Veillonellaceae phylotypes evolved from an ancestral gastrointestinal lineage to inhabit the vaginal niche. We present evidence of their divergence and subniche specification and describe their differential associations with vaginal infection and pregnancy. In Chapter 3, we identify ten bacterial taxa, predicted to contribute to the …

The Role Of A Type Lamins In Regulating Myelination, Jacqueline M. Deloyht

Theses and Dissertations

Multiple sclerosis (MS), a demyelinating disorder of the central nervous system (CNS), affects approximately 400,000 individuals in the United States, and 2.5 million people worldwide. It is a leading cause of disability in young adults. Current treatments for MS target the inflammatory aspects of the disease, but do not aid in remyelination. To address remyelination as a therapeutic strategy, it is imperative to identify mechanisms that regulate myelin formation, including epigenetic targets. In this study, we investigate the role of the LMNA, a gene encoding Lamins A and C, intermediate filaments of the nuclear lamina, in regulating oligodendrocyte development and …

A Novel, Orally Active Hydrogen Sulfide-Releasing Compound, Sg1002, Improves Left Ventricular Function With An Associated Induction Of Angiogenesis In A Murine Model Of Ischemia/Reperfusion, Om A. Evani

Theses and Dissertations

Hydrogen sulfide (H₂S) is the newest member of the gasotransmitter family and is becoming well known for its cardioprotective effects in preclinical trials. Many recent studies have shown the benefits of exogenous H₂S in the setting of acute myocardial infarction (AMI) and pressure overload-induced heart failure, but current formulations are derived from inorganic salts which have shortcomings in the precision and control of release of H₂S. The main objective of this thesis was to determine if the novel, orally active, slow-releasing compound, SG1002, can attenuate the severity of damage and adverse remodeling caused by …

A Familiar House, William Lenard

Theses and Dissertations

The landscapes of my home in Connecticut are important to me. When I was young, I went to the woods for seclusion and comfort. While I wandered through the woods, I discovered a passion for storytelling. Now that I no longer live in New England, I miss the familiar landscapes of home. As a way to portray my sentiment, I write poetic narratives and create objects to illustrate natural landscapes.

I combine my interests of classic Americana art and literature with brutalist architecture and modern furniture to create immersive installations. I work with concrete and hardwood to materially bridge the …

There Is Someone In This Dress, George, Michael S. Royce

Theses and Dissertations

Questions surrounding queer subjectivity—including shame, the closet, and celebration—are at the core of my interests as a painter and image maker. Mining the history of religious iconography, including annunciation paintings, scenes of the crucifixion, and other notable works of this ilk, my paintings seek to explore the intricacies of sexuality and the workings of shame and celebration at play in the life of the queer-identified.

Nam June Paik As A Pioneer Of Interactive Art, Byeongwon Ha

Theses and Dissertations

Nam June Paik (1932-2006) is well known as the father of video art. However, this study demonstrates the importance of his earlier interactive art (1961-63), which historically has been overshadowed by his video art. At the climax of his career in interactive art, Paik introduced his two-way art to the public at his first solo exhibition in Wuppertal, West Germany, in 1963. Interactive art itself has been a peripheral area in the history of art, and it has plural pioneers across disciplinary boundaries. Among the several origins of interactive art, Nam June Paik utilized music as a fundamental approach to …

Cellular Inhibitor Of Apoptosis Protein2 – A Critical Regulator Of Neuroinflammation, Debolina Dipankar Biswas

Theses and Dissertations

Inhibitors of apoptosis (IAPs) modulate cell death and play critical role in signal transduction that promotes inflammation. Recently, Smac mimetics, which are IAP antagonists, have attracted attention as novel cancer therapeutics. Cellular Inhibitor of Apoptosis 2 (cIAP2), a member of IAP family, positively affects both NF-κB and MAPK activation in response to many inflammatory stimuli. We observed that the lack of cIAP2 ablates LPS-induced neuroinflammation. Also, cIAP2^-/- macrophages demonstrated diminished antigen presentation potential that could contribute to ablated immunity. In addition to these functions, we have previously reported that cIAP2 also regulates the activation of Interferon Regulatory Factor 1 …

Abuse Liability Of An Electronic Cigarette In Traditional Cigarette Smokers, Sarah F. Maloney

Theses and Dissertations

Electronic cigarettes have grown in popularity across the U.S. and concerns have been raised about their abuse liability. The purpose of the current study was to evaluate and compare the abuse liability of an electronic cigarette with and without nicotine to a nicotine inhaler (the Nicotrol inhaler) and participants’ own brand of cigarettes. A total of 24 smokers attended four sessions in which the abuse liability of each product was examined using the Multiple-Choice Procedure (MCP), nicotine delivery, nicotine abstinence symptom suppression, and subjective reinforcing effects. Results revealed that the nicotine containing and non-nicotine containing electronic cigarette had a higher …

Social Soul, Norah Alshammari

Theses and Dissertations

Twitter has over 313 million users, with 500 million tweets produced each day.

Society’s growing dependence on the internet for self-expression shows no

sign of abating. However, recent research warns that social media perpetuates

loneliness, caused by reduced face-to-face interaction. My thesis analyzes and

demonstrates the important role facial expressions play in a conversation’s

progress, impacting how people process and relate to what is being said. My

work critically assesses communication problems associated with Twitter. By

isolating and documenting expressive facial reactions to a curated selection

of tweets, the exhibition creates a commentary on our contemporary digital

existence, specifically articulating …

Lps-Induced Inos Mrna And The Pro-Apoptotic Signaling Pathway In Leukocytes Of Fit And Unfit Males, Tiffany M. Zuniga

Theses and Dissertations

Overexpression of the enzyme iNOS induces apoptotic cellular death by increasing indices of pro-inflammation and oxidative stress. Aerobic physical activity has been known to have anti- inflammatory benefits and reduce oxidative stress. Purpose: Therefore, this study aimed to examine the impact of aerobic fitness on LPS-induced iNOS mRNA expression and the relationship of this expression with indices of oxidative stress, pro-inflammation and apoptosis in isolated leukocytes. Methods: Whole blood samples from aerobically fit and unfit males were stimulated with and without LPS. Thereafter, iNOS mRNA expression and MDA, TNF-α and p53 concentrations were analyzed. Results: iNOS mRNA expression levels following …

Redox Reactions At Oil-Water Interface By Particle Collision Electroanalysis, Dilip K. Paul

Theses and Dissertations

Particle Collision Electrochemistry (PCE) has gained considerable attention in heterogeneous catalysis, petroleum chemistry and pharmaceutical fields. The PCE refers to a phenomenon in which a particle strikes on an inert electrode surface as a consequence of its Brownian motion and produces a spike of current for the direct oxidation/reduction of the individual particle. This method allows us characterization of individual particles and in-situ study of electrochemical reactions coupled to the particle.

Herein, emulsion droplets were studied by PCE where toluene droplets contained hydrophobic tetrachloro-1,4-benzoquinone (Q). This was investigated as a model system to study the molecular effects that arise due …

Detection Of Genetic Abnormalities Using High Speed Atomic Force Microscopy, Anita J. Olsen

Theses and Dissertations

Genetic mutations in the regulatory genes responsible for cell proliferation, differentiation, and death play a significant role in cancer. Molecular diagnostic and sequencing techniques used to detect these abnormalities have limitations that need to be overcome. These issues can be addressed with the use of a novel High-Speed Atomic Force Microscope (HS-AFM) taking physical measurement of molecules labeled with a programmable nanoparticle (Cas9). This technique was used to demonstrate proof-of-concept using genetic mutations found in breast cancer and follicular lymphoma.

Current quantification methods for copy number variation (gene duplication) and gene expression analysis are based on amplification and fluorescence-based techniques …

Chronic Clozapine Treatment Impairs Functional Activation Of Metabotropic Glutamate Receptor 2 Via An Hdac2-Depedent Mechanism, Travis M. Cuddy

Theses and Dissertations

Schizophrenia is a chronic mental disorder affecting millions worldwide. It has no known cure. Current pharmaceutical treatments have shown efficacy in only one of the three symptom clusters of schizophrenia, providing little or no benefit in the other two. Furthermore, the current standard-of-care drugs, known as atypical antipsychotics, carry risks of severe side effects affecting multiple body systems. Most patients opt to discontinue drug therapy within two years of initiation due to lack of efficacy and/or preponderance of adverse effects. Previous findings have shown that chronic usage of atypical antipsychotics causes a 5-HT_2A-dependent upregulation of histone deacetylase 2 …

Effects Of The Na-Cl Co-Transporter (Ncc) In Western Diet Induced Metabolic And Cardiac Dysfunction, Zachary S. Cutter

Theses and Dissertations

Interleukin-18 (IL-18) is a pro-inflammatory cytokine known to be involved in maintaining metabolic homeostasis; however, also capable of inducing cardiac dysfunction. Additionally, IL-18, has been shown to bind to a novel receptor, the Na-Cl Co-transporter (NCC). We hypothesized that NCC mediates IL-18 metabolic and cardiac signaling in mice. Using male C57BL/6J mice, we compared the metabolic and cardiac function changes after at least 8 weeks of high-saturated fat high sugar diet (Western Diet) in NCC knockout (NCCKO), IL-18 knockout (IL-18KO), and wild-type mice. We show that NCCKO mice have significantly increased body weight gain from baseline, no difference in fasting …

Migratory Patterns And Population Genetic Structure In A Declining Wetland-Dependent Songbird, Matthew G. Desaix

Theses and Dissertations

Understanding migratory connectivity is essential for assessing the drivers behind population dynamics and for implementing effective management in migratory species. Genetic markers provide a means to describe migratory connectivity, as well as incorporate population genetic analyses, however genetic markers can be uninformative for species with weak genetic structure. In this study, we evaluate range-wide population genetic structure and migratory connectivity in the prothonotary warbler, Protonotaria citrea, a wetland-dependent neotropical migratory songbird, using high-resolution genetic markers. We reveal regional genetic structure between sampling sites in the Mississippi River Valley and the Atlantic Seaboard with overall weak genetic differentiation among populations …

Ultrasound—Re:Viewing Bodies, Minjee Jeon

Theses and Dissertations

A medical evaluation of physical impairment imposes the additional burden of “labeling” the patient with the condition. The binary nature of the normal versus abnormal label emphasizes difference and can lead to trauma. Understanding differences, however, can lead to the generation of new forms and thus, more sensitive differentiation and representation. Tension is created by exploring different bodily forms—a dialectic between form and essence. I am designing a space that visualizes and illuminates difference as a source of trauma and amplifying the tension by comparing figures that represent varying degrees of normalcy. This forms a critique of idealized form and …

Investigating Smoke Exposure And Chronic Obstructive Pulmonary Disease (Copd) With A Calibrated Agent Based Model (Abm) Of In Vitro Fibroblast Wound Healing., James A. Ratti

Theses and Dissertations

COPD is characterized by tissue inflammation and impaired remodeling that suggests fibroblast maintenance of structural homeostasis is dysregulated. Thus, we performed in vitro wound healing experiments on normal and diseased human lung fibroblasts and developed an ABM of fibroblasts closing a scratched monolayer using NetLogo to evaluate differences due to COPD or cigarette smoke condensate exposure. This ABM consists of a rule-set governing the healing response, accounting for cell migration, proliferation, death, activation and senescence rates; along with the effects of heterogeneous activation, phenotypic changes, serum deprivation and exposure to cigarette smoke condensate or bFGF. Simulations were performed to calibrate …

Consuming Digital Debris In The Plasticene, Stephen R. Parks

Theses and Dissertations

Claims of customization and control by socio-technical industries are altering the role of consumer and producer. These narratives are often misleading attempts to engage consumers with new forms of technology. By addressing capitalist intent, material, and the reproduction limits of 3-D printed objects’, I observe the aspirational promise of becoming a producer of my own belongings through new networks of production. I am interested in gaining a better understanding of the data consumed that perpetuates hyper-consumptive tendencies for new technological apparatuses. My role as a designer focuses on the resolution of not only the surface of the object through 3-D …

Advances In Dual-Energy Computed Tomography Imaging Of Radiological Properties, Dong Han

Theses and Dissertations

Dual-energy computed tomography (DECT) has shown great potential in the reduction of uncertainties of proton ranges and low energy photon cross section estimation used in radiation therapy planning. The work presented herein investigated three contributions for advancing DECT applications. 1) A linear and separable two-parameter DECT, the basis vector model (BVM) was used to estimate proton stopping power. Compared to other nonlinear two-parameter models in the literature, the BVM model shows a comparable accuracy achieved for typical human tissues. This model outperforms other nonlinear models in estimations of linear attenuation coefficients. This is the first study to clearly illustrate the …

Rational Design Of Allosteric Modulators Of Hemoglobin As Dual Acting Antisickling Agents, Piyusha P. Pagare

Theses and Dissertations

Intracellular polymerization of deoxygenated sickle hemoglobin (Hb S) remains the principal cause of the pathophysiology associated with sickle cell disease (SCD). Naturally occurring and synthetic allosteric effectors of hemoglobin (AEH) have been investigated as potential therapeutic agents for the treatment of SCD. Several aromatic aldehydes, including vanillin, have been studied previously as AEHs for their antisickling activities. Specifically, these compounds form Schiff- base adduct with Hb to stabilize the oxygenated (R) state, increase Hb affinity for O2 and concomitantly prevent the hypoxia-induced primary pathophysiology of Hb S polymerization and RBC sickling, in turn, ameliorating several of the cascading secondary adverse …

The Development Of Novel Inhibitors Of The Nlrp3 Inflammasome, Jacob W. Fulp

Theses and Dissertations

Inflammasomes are intracellular multimeric protein complexes that regulate inflammation by controlling the maturation of cytokines, interleukin-1β (IL-1β) and interleukin-18 (IL-18). Additionally, activation of these inflammasome complexes has been implicated in an inflammatory form of death known as proptosis. Of the known inflammasomes, the NOD-like receptor family pyrin domain containing 3 (NLPP3) inflammasome, is the most elucidated. Under physiological conditions, NLRP3-mediated inflammation promotes healing and the elimination of cellular debris and pathogens. However, the dysregulation of IL-1β, IL-18 and pyroptosis are instrumental in the development of multiple pathologies. Furthermore, studies suggest that the NLRP3 inflammasome mediates detrimental neuroinflammation and …