Digital Commons Network^™

Interspecific Gene Flow Potentiates Adaptive Evolution In A Hybrid Zone Formed Between Pinus Strobiformis And Pinus Flexilis, Mitra Menon

Theses and Dissertations

Species range margins are often characterised by high degrees of habitat fragmentation resulting in low genetic diversity and higher gene flow from populations at the core of the species range. Interspecific gene flow from a closely related species with abutting range margins can increase standing genetic diversity and generate novel allelic combinations thereby alleviating limits to adaptive evolution in range margin populations. Hybridization driven interspecific gene flow has played a key role in the demographic history of several conifer due to their life history characteristics such as weak crossability barriers and long generation times. Nevertheless, demonstrating whether introgression is adaptive …

E-Liquid Exposure Causes Multiple Cardiovascular Defects In Xenopus Laevis Embryos, James E. Black Iii

Theses and Dissertations

Over the past several years vaping has become part of the cultural zeitgeist in the United States, with ECIG usage amongst those of reproductive age rising more and more. Due to a lack of regulation and research concerning their long term effects, public opinion trends toward the idea that they are somehow safer than their traditional counterparts. As cases of lung injury and ECIG related death are beginning to be reported more and more, it is clear that the misinformation about their safety is unfounded. Congenital heart defects (CHDs) are some of the most common birth defects currently in the …

Amixicile As A Novel Antimicrobial Treatment For Periodontitis: A Pilot Study In The Non-Human Primate, Macaca Mulatta, Denver J. Lyons

Theses and Dissertations

Periodontitis is an inflammatory disease with a bacterial etiology in a susceptible host. Given the bacterial etiology, a selective antimicrobial agent with minimal side effects could be a useful adjunct to traditional therapy. Amixicile is a novel antimicrobial that targets the pyruvate: ferredoxin oxidoreductase (PFOR) which is an enzyme that is critical for anaerobic bacterial metabolism. It has been found to have no effect on commensal, aerobic microbes and has little to no side-effects thus far in animal models. In this study, two nonhuman primates of the Macaca mulatta species with naturally occurring mild chronic periodontitis were studied before and …

Repeat Full Mouth Dental Rehabilitation Under General Anesthesia For Medicaid Eligible Healthy Children Who Are High Caries Risk, Lajoi E. Wiggins

Theses and Dissertations

Purpose: To evaluate the treatment of healthy children who are high caries risk and of low socioeconomic status and who require repeat full mouth dental rehabilitation (FMDR) under general anesthesia (GA).

Methods: A retrospective chart review was performed on healthy Medicaid eligible patients who were initially between 18 months - 6 years of age who underwent FMDR under GA in the OR more than once at the Virginia Commonwealth University (VCU) School of Dentistry, Department of Pediatric Dentistry from January 2008 to December 2018. Biographical information for each patient was gathered into a REDCap™ Survey. Statistical analysis, chi-squared test with …

Exploring The Heteromeric Interface Of The 5-Ht2a-Mglu2 Receptor Complex, Mohamed Aarif Abdul Kareem

Theses and Dissertations

Schizophrenia is a serious mental disorder characteristic of several neurotransmitters including dopamine, serotonin, and glutamate being in imbalance. Early therapies focused solely on dopamine antagonism and second-generation antipsychotics focused on the dopamine and serotonin systems and their respective G protein coupled receptor (GPCR) proteins. Although debate for dimerization of certain classes of GPCR exist, the establishment of an mGlu2-5-HT_2A heterocomplex, which is implicated in schizophrenia is of interest. Previous studies have used a mutation-based approach to identify transmembrane domain 4 (TM4) as the domain responsible in mGlu2 for mediating heteromerization before narrowing down the individual amino acids responsible for …

Pharmacology Of Fentanyl-Related Substances In Mice Reveals Potential Therapeutics With Improved Protective Indices, Neil B. Varshneya

Theses and Dissertations

Fentanyl-related substances constitute a class of compounds that were originally developed in the latter half of the 20th century as combination analgesic-anesthetic agents. Today, many of these compounds have emerged in the recreational drug marketplace as adulterants to heroin, counterfeit prescription pills, and even as standalone products designed to circumvent drug control laws. The objective of this dissertation was to identify the structural determinants of fentanyl analogs that could affect the potency and efficacy for eliciting their therapeutic and toxic effects to identify candidates of potential therapeutic interest. To accomplish this objective, thirty-eight fentanyl-related substances, in addition to the MOR …

Synaptic Plasticity In A Visual Cortical Region Induced By Early-Deafness, John M. Kay

Theses and Dissertations

When organisms learn and adapt to their environment or lose a sensory modality, neurons in the brain undergo a cellular process called ‘plasticity.’ This thesis explores the loss of a non- visual system (early deafness) and how it can affect visual plasticity. To examine this question, Golgi-stained cortical neurons were studied from the visual region PLLS from early-deaf cats and their hearing controls. Dendritic spine density and dendritic spine diameter are well-known indicators of synaptic plasticity and these neuronal features were measured using light microscopic techniques and Neurolucida. Within the visual PLLS, the mean spine density for the deaf cats …

Systematic Model-Based Design Assurance And Property-Based Fault Injection For Safety Critical Digital Systems, Athira Varma Jayakumar

Theses and Dissertations

With advances in sensing, wireless communications, computing, control, and automation technologies, we are witnessing the rapid uptake of Cyber-Physical Systems across many applications including connected vehicles, healthcare, energy, manufacturing, smart homes etc. Many of these applications are safety-critical in nature and they depend on the correct and safe execution of software and hardware that are intrinsically subject to faults. These faults can be design faults (Software Faults, Specification faults, etc.) or physically occurring faults (hardware failures, Single-event-upsets, etc.). Both types of faults must be addressed during the design and development of these critical systems. Several safety-critical industries have widely adopted …

A Comparison In Pediatric Dental Website Design From A Guardian And Pediatric Dentists’ Perspective., David M. Voth

Theses and Dissertations

Purpose: This project aims to determine which aspects of pediatric dental practice websites are preferable to the guardians of pediatric dental patients and which of these aspects are currently available to guardians on the websites of pediatric dental practices across the United States. The comparison will reveal if practice websites are meeting the needs of the guardians of pediatric dental patients. Our hope is to provide meaningful guidance to pediatric dentists designing new practice websites and to provide the guardians of pediatric dental patients with an appealing online experience during their use of the aforementioned websites. Methods: A survey with …

Investigating The Role Of Oncogene C-Terminal Binding Protein (Ctbp) In Pancreatic Ductal Adenocarcinoma, Kranthi Kumar Chougoni

Theses and Dissertations

The transcriptional coregulator CtBP2 has been implicated as an oncogene in colon, prostate, breast and ovarian cancers. Previously, we reported overexpression of CtBP2 in human PDAC specimens. However, its exact role in PDAC is still unclear. In the current study, we attempt to delineate the oncogenic role CtBP2 in PDAC growth and metastasis. Using an orthotopic syngeneic pancreatic tumor mouse model (CKP), we found that deletion of Ctbp2 decreases PDAC tumor growth, proliferation, metastasis, EMT and significantly prolongs survival. Further, we identified significant downregulation of Erbb3 mRNA levels upon deletion of Ctbp2 in CKP PDAC cells As ErbB3 signaling was …

Three Studies Of Research-Based Pedagogy In Physical Chemistry: Development Of A Zno Thin Film Experiment, Analysis Of Student Discourse By Graph Theory And Cognitive Engagement, Building A Physical Chemistry Faculty Network., Dilhara Liyanage

Theses and Dissertations

Three research projects, each focusing on a different aspect, development of a ZnO thin film experiment, student’s cognitive engagement behavior, and building of a faculty network, are presented in this dissertation.

In the first project, a physical chemistry laboratory experiment was developed to answer the question, “How do electrons move in a solid?”. The experiment structure follows the POGIL-PCL (Process Oriented Guided Inquiry Learning - Physical Chemistry Laboratory) model. Students begin by using the PhET “Quantum Bound States” animation to compare energy levels for single atoms to energy levels of a lattice containing many potential wells, and they incorporate that …

Internalizing Data Collection: Personal Analytics As An Investigation Of The Self, Neal R. Swisher

Theses and Dissertations

Personal analytics, aka self-tracking, is the practice of using a digital device to track aspects of behavior, such as exercise habits, heart rate, sleep patterns, location, diet, and a host of other data points. This dissertation is an exploration of “self” in self-tracking, informed by theories of subjectivity, autonomy, power and knowledge. As a technological intervention, self-tracking devices change how we experience our own body and behavior. They also serve as methods to digitize human behavior. This data is combined with other data and processed using computational methods. Self-tracking devices are both personal and bureaucratic. They are devices used for …

Examining Body Mass Index And Sepsis Mortality At One Year After Sepsis, Jamie D. Robinson

Theses and Dissertations

Introduction: Sepsis is a serious and life-threatening syndrome affecting 1.7 million Americans annually and resulting in approximately 270,000 deaths. An “obesity paradox” where obese individuals have lower sepsis mortality than their non-obese counterparts has been described. The problem is that the longevity of the effect is unknown, and few studies have examined the obesity paradox after 1-2 months post-diagnosis.

Methods: This retrospective cohort study examined clinical, demographic, and biomarker variables thought to affect sepsis mortality at three-time points: 30 days, 180 days, and at one year post-sepsis diagnosis in order to shed light on specific factors that might define …

Regulation Of Vascular And Lymphatic Endothelial Barrier Function By Sphingosine-1-Phosphate, Jacqueline Bellaci

Theses and Dissertations

Endothelial cells play an important role in maintaining homeostasis, and disruption of the endothelial barrier have been linked to a number of different pathologies, including cancer metastasis. The vascular endothelial barrier is known to be regulated by a variety of factors, including sphingosine-1-phosphate (S1P), a bioactive lipid metabolite, which has been shown to improve barrier function. However, most studies to date have been focused on the vascular endothelium, and the regulation of the lymphatic endothelial barrier has not been thoroughly investigated. We found that prior to any stimulation the lymphatic endothelial cells (LECs) had a lower trans-endothelial resistance (TER) in …

Martian Mother, Elizabeth Mcgrady

Theses and Dissertations

This paper examines the relationship between humans and land, through the lens of the scientific and religious, bridging the physical realm with the spiritual. It acts as accompanying material to the project titled Martian Mother, supplementary information to the visual work, and an extension of the proposal, the center of the work. The proposal exists to send myself, or a like-minded individual, to Mars with artificial insemination equipment to give birth to the first Martian, becoming the first Martian Mother. This work is rooted firmly in speculative fiction, creating a nonlinear future framework for a new society and space exploration.

Spit In My Mouth: Queer Intimacies, Material Intra-Actions, And Sensuous Becoming, Gm Keaton

Theses and Dissertations

This document describes my multidisciplinary art practice as it intersects with New Materialism, Queer and Affect theory, Ecology, and my embodied and experiential knowledge as a queer subject. The writing is divided into two categories. One is more theoretical, thinking through these different discourses. The other realizes them through relationships and intra-actions between my material kin and me. With these two modes of writing,I propose that embodied and felt knowing is as valid and illuminating as more traditional forms of knowledge. These sections are interdependent and resist linear logic, offering relational meanings to each reader as they find their way …

A Girl Is A Girl Is A Girl, Paige Lizbeth Morris

Theses and Dissertations

It is well known that Western society uses men’s visual pleasure as a means to determine womxn’s value; her success is dependent on her compliance with culturally determined beauty standards. This process turns womxn into commodities and reinforces notions of gender complementarity, perpetuating a lifetime of servitude to patriarchal ideologies. It reminds the non-male that she is incomplete, insufficient, insignificant, and so easily dismissable. It forces her to be dependent, to shut up, to sit down, and to enjoy it.

In an effort to reject these presumed histories and narrow connotations of womxn, I have analyzed my gender performance in …

Prey Begins With Play, Seren C. Moran

Theses and Dissertations

My work examines the lasting psychological and emotional torment of trauma focusing on sexual violence against women. My thesis consists of five short animated films recounting non-fiction experiences of sexual assault. To contextualize my work within cultural and historical representations of sexual violence, this text reflects my research on the mishandling of rape in Western art history as well as contemporary politics and cinema. In both my work and research, I address the complicated, and often contradictory, internal reality of experiencing and remembering trauma and how this relates to artistic strategies such as collage and maximalism. My personal struggles recovering …

Structural Features Contributing To Methylenedioxypyrovalerone (Mdpv) Analog Inhibition Of The Human Dopamine Transporter, Zachary R. Spires

Theses and Dissertations

Monoamine transporters (MATs) are transmembrane neurotransmitter sodium symporters consisting of the dopamine, norepinephrine, and serotonin transporters: DAT, NET, and SERT, respectively. Following an action potential and neurotransmitter vesicular release, MAT-mediated reuptake of these neurotransmitters in the presynaptic membrane contributes to the termination of monoaminergic neurotransmission. MATs are the targets of many drugs providing therapeutic benefits or taken recreationally. One of these drugs is methylenedioxypyrovalerone (MDPV), an abused synthetic cathinone that is a high potency uptake inhibitor of the human DAT (hDAT). In contrast, MDPV is a low potency uptake inhibitor of the Drosophila melanogaster dopamine transporter (dDAT). The reasons for …

Ghost Signs Are More Than Paintings On Brick, Eric Anthony Berdis

Theses and Dissertations

My work embraces a maximalist aesthetic that incorporates, archival research, personal secrets, and pubescent gay boy glamour. I seek to create a stimulating yet jarring experience, while building a world that is both familiar and inherently strange to the viewer. Thrift store cast-offs, hobbyist craft supplies, and saturated drawings are reassembled into a cast of characters and costumes that balance on the line between ghosts, creatures, and friends. While we often think of costume and even art installations as meant to cover bodies and walls, my work tends to reveal more than conceal. I aspire through this work to shine …

Arabic Beyond Arabic, Abir Zakzok

Theses and Dissertations

Arabic is the best and the most complicated language of all time!” Even though this statement seems like an exaggeration, it is what I grew up hearing; from my Arab parents as a child, my Arab teachers as a student, and my Arab customers as a salesperson. The Arabic language has a significant role in Arabs’ identity, yet most Arabs only scratch the surface and do not fully grasp the embedded meaning of the language. I have long been fascinated by the relationship between language and community as well as how it translates to design - specifically, the relationship between …

Machine Girl, Yutong Liu

Theses and Dissertations

Machine girl is a character that mimics biology, labor, and humanity.

She relates to machine sympathy and machine learning; She is updating and processing of big data. During the interaction between me and the machine, I found you --- Machine girl.

Machine girl is a brilliant girl. She is an excellent translator and communicator, which is determined by her ability for machine learning. The cyber living space gives her a fundamental learning gift with a mathematical algorithm. She uses this gift to mimic everything from the human brain. She is not reasonable but sensitive. There are many different versions of …

Fool's Rest, Aidan Quinlan

Theses and Dissertations

The text calls itself a guide, but it is no guide. From the genre of guide, it borrows the outlines and silhouettes and lines between things and spaces and ideas. It lingers on the shadows of its subject(s); it is attentive to the periphery of its world; but it cannot take you there. There is no there. It lacks the authority of the guide; it lacks the lucidity, the efficiency, the false totality of the guide; it lacks the confidence.

The guide embodies its own anxieties. This makes sense, as its reason to exist was born on the one-way highway …

Library By Day, Theater By Night, Julia Moncure Jones Mishler

Theses and Dissertations

This project will re-conceive a historic movie theater, honoring the program of the building as it was originally intended, while introducing a new programmatic element: the library. Instead of this large space only being used in the evenings for movie showings, it will now also be a place for the public to gather during the day as a popular materials library. This project is an exploration of diversion through literature and cinema. This space will continue to be a landmark in Richmond and a place community members visit on a regular basis.

How do new elements introduced into a historic …

Development Of Dexamethsone Sodium Phosphate Loaded Nanoparticles For Treating Corneal Allograft Rejection, Vineet R. Kulkarni

Theses and Dissertations

Corneas are the most commonly transplanted tissue worldwide, with approximately 80,000 transplantations performed in the United States in 2018 alone. Corneal transplantation is used to restore the vision due to opaque corneas in various diseases such as fungal keratitis, keratoconus, Fuchs’s dystrophy, corneal ulceration, traumatic injury, abrasions or scarring, inflammation, and infection. Corneal transplant surgery could involve replacing the entire cornea (penetrating keratoplasty) or selective replacement of the corneal layers (e.g. Descemet’s membrane endothelial keratoplasty and deep anterior lamellar keratoplasty). Immunologic graft rejection is one of the main causes of graft failure in these corneal transplantations. The 2-year rejection rate …

Reaction Profiling Of Extracellular Protein Phosphorylation Through A Microfluidic Reactor Coupled With Raman Spectroscopy, Abigail Casey

Theses and Dissertations

Diseases and disorders in the human body are considered abnormalities of proper cellular function. Understanding the signal transduction mechanisms that cause these abnormalities is crucial to developing earlier detection methods, better treatment options and effective cures. While current diagnostic procedures are powerful tools in diagnosing diseases, they are ineffective in informing physicians on the real-time behavior of the signal transduction mechanisms associated with diseases and disorders. Currently, disease progression is monitored over time through routine patient visits and testing by one or more of the above techniques. By developing an approach that can monitor structural and conformational changes of proteins …

Dendrimer-Based Therapeutic Delivery Vehicle For The Treatment Of Ocular Diseases, Remy C. Cooper

Theses and Dissertations

The treatment of ocular diseases poses a significant challenge to drug delivery design, due to the eye’s complex anatomy, with a semi-permeable blood-ocular barrier and associated immune privilege. To address some of the delivery challenges, polycationic dendrimers are explored as vehicle for the treatment of posterior chamber disease. Dendrimers are a class of polymeric nanoparticles that are highly branched, multivalent and monodisperse, whose three-dimensional globular architecture has given them the nickname of “synthetic proteins”. Dendrimers are synthesized by reacting monomers in a step-wise fashion to produce generationally and radially increasing structures, with core, interior and surface chains that are highly …

Characterization Of The Gonococcal Calprotectin Zn-Acquisition System, Tdfh, And The Efficacy Of Metal Starvation For Treating Gonococcal Disease, Michael T. Kammerman

Theses and Dissertations

Abstract

Characterization of the Gonococcal Calprotectin Zn-Acquisition System, TdfH, and the Efficacy of Metal Starvation for Treating Gonococcal Disease.

By Michael T. Kammerman, B.S.

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University

Virginia Commonwealth University, 2020

Major Director: Cynthia Nau Cornelissen, Ph.D.

Professor, Department of Microbiology and Immunology

Neisseria gonorrhoeae, the bacterial agent that is responsible for the human disease gonorrhea, has had a steady increase in the number of infections per year. In 2018 the WHO estimated over 87 million infections occurred world-wide, and the CDC …

Surrogate Memories In Animation And Sound, Jared Duesterhaus

Theses and Dissertations

A document in support of my exploration into memory in relation to the mediums of animation, sound, and theater. A reflection on remembering as a creative act.

It’S Funny Because It’S True: The Transmission Of Explicit And Implicit Racism In Internet Memes, Tabitha Fairchild

Theses and Dissertations

Video games are traditionally seen as the domain of heteronormative white males. The purpose of this study is to explore how racism is transmitted and reproduced within digital communities, and how humor is being used to frame racist discourse in virtual spaces. Digitally, internet memes are widely used rhetorical vehicles, reaching large and broad audiences. The roles these artifacts play in the reproduction and transmission of racist ideology is often obfuscated by the perception that internet memes are "just jokes." This study analyzes internet memes collected from 16 months of communication between members of Discord servers that self-identify as communities …