Digital Commons Network^™

The Role Of The Mechanical Environment On Cd117+ Endothelial Cell Angiogenesis, Patrick Link

Theses and Dissertations

Angiogenesis is a complex process coordinating cell migration, proliferation, and lumen formation. Changes to the microenvironment regulate angiogenesis through mechanotransduction and cytokine signals. In pulmonary hypertension, something in the process becomes abnormal, resulting in changes to the microenvironment and the formation of a glomerulus of dysfunctional capillaries, called a plexiform lesion. Endothelial cells, expressing CD117 (CD117+ EC clones) increase in the plexiform lesions of pulmonary hypertension, independent of pro-angiogenic VEGF signaling. We hypothesize that the mechanical environment and the macromolecular composition of the extracellular matrix, both, contribute to the aberrant angiogenesis. When we changed the mechanical environment, we changed the …

Engineering The Alveolar Gas Exchange Barrier With Extracellular Matrix Coatings For Bioengineered Lungs, Bethany M. Young

Theses and Dissertations

Lower respiratory diseases are currently the third leading cause of death worldwide. For many end-stage patients with these diseases, there is no cure and a shortage of donor organs available for transplant. A promising solution is to design regenerative scaffolds or complete bioengineered lungs, using decellularized lung tissues as a template for regeneration. Recent advances in the field have made significant strides towards developing a transplantable lung. However, the current technology has not produced a functional lung for in vivo transplant due to immature gas exchange barriers. The mechanisms driving alveolar barrier maturation and role that extracellular matrix (ECM) plays …

An Adaptation And Psychometric Evaluation Of The Teacher Attribution Measure For Early Elementary (Tam-Ee), Shannon L. Nemer

Theses and Dissertations

This study examined the reliability and validity of the Teacher Attribution Measure for Early Elementary (TAM-EE), a measure adapted from the Preschool Teaching Attributions (PTA) measure, to assess the challenging behavior attributions of early elementary teachers. Like the PTA, the TAM-EE uses a series of student-specific behavior scenarios as prompts for teachers who then rate statements aligned with dimensions of attribution theory on a 6-point scale. A sample of 41 teachers completed the TAM-EE on 79 students in grades K-3 screened for risk of emotional and behavioral disorders (EBD). Teachers also completed reports of student behavior, self-efficacy, and perceptions of …

Embryonic Stem Cell-Derived Exosomes Increase The Antiproliferative Activity Of Doxorubicin In Breast Cancer, Alexander M. Hirsch

Theses and Dissertations

The field of cancer research has grown immensely in recent decades and has led to a better understanding of the causes of the disease, as well as greatly improved treatment for various types of cancers, especially breast cancer. One of the most effective treatments involves the chemotherapeutic drug doxorubicin (DOX). DOX is an effective tool against all types of breast cancer, especially against triple negative breast cancer. However, DOX causes adverse side effects that include damage to the heart and skeletal muscle, particularly above specific cumulative doses. Recent evidence suggests that embryonic stem cell-derived (ES) exosomes, nanoscale extracellular vesicles that …

A Hybrid Molecule Of Melatonin And Curcumin For Therpeutic Use In Pulmonary Fibrosis, Varsha V. Nair

Theses and Dissertations

Pulmonary fibrosis (PF) is a serious lung disease, as its life expectancy is only 3-5 years upon occurrence and more than 50 % of the cases are idiopathic, i.e., unknown cause. Two drugs, pirfenidone (PIR) and nintedanib, have recently been approved; however, their efficacies are moderate without evidence of prolonged survival. While this is primarily due to our insufficient knowledge about key PF pathogenesis, inductions of oxidative stress and transforming growth factor-b1 (TGF-b1) have been suggested in PF lungs. Hence, anti-oxidative melatonin (MEL) and curcumin (CUR) have been studied yet their efficacies remain moderate without clear understanding about the mechanisms …

The Influence Of Electronic Cigarette Heating Coil Resistance On Nicotine Delivery, Heart Rate, Subjective Effects, And Puff Topography, Marzena M. Hiler

Theses and Dissertations

Electronic cigarette (ECIG) users can manipulate several device features including liquid nicotine concentration (mg/ml) and heating coil resistance (Ohms). One class of ECIG models, called “sub-Ohm” devices, use coils with a resistance of < 1 Ohms, lower than those observed in conventional ECIGs (e.g., ≥ 1.5 Ohms). Increasing voltage or decreasing coil resistance increases device power. Given that ECIG coil resistance and liquid nicotine concentration have not been manipulated systematically and simultaneously in clinical laboratory studies, the influence of these factors on ECIG acute effects remain unclear. The primary purpose of this study was to examine the influence of coil resistance and liquid nicotine concentration on nicotine delivery, heart rate (HR), subjective effects, puff topography, and liquid consumption.

Thirty-two experienced ECIG users completed four independent laboratory sessions that differed by coil resistance (0.5Ohm or 1.5Ohm ) and liquid nicotine concentration (3 or 8 mg/ml). In each session, participants used a 4.5 V “Kanger SUBOX” loaded with 3.5 ml ECIG liquid in a 10-puff directed and 60-minute ad libitum bout. Nicotine delivery was greatest when using 8 mg+0.5Ohm combination and lowest when using the 3 mg/ml+1.5Ohm …

Fluoxetine Attenuates Mast Cell Function By Targeting Purinergic Signaling, Tamara T. Haque

Theses and Dissertations

Mast cells are tissue resident, innate immune cells that provide protection against parasitic and bacterial infections and venom poisoning. Mast cells also play a pathogenic role in atopy and allergic diseases. Atopy and allergic diseases are increasing in the developed world and are predicted to continue to increase at an alarming rate. Current treatment options include corticosteroids, anti-histamines, anti-IgE and avoidance of allergen. These interventions have limitations: some patients are steroid resistant; anti-histamines have low efficacy since they need to be administered early during allergen exposure; and anti-IgE is costly. Thus there is a clinical need for new treatment options. …

Illumination Of The Golgi Apparatus Of Pathogenic And Nonpathogenic Naegleria Species, Tyler M. Poe

Theses and Dissertations

In this study, Naegleria fowleri, a pathogenic amoeba and the causative agent of Primary Amebic Meningoencephalitis (PAM), was utilized to determine the presence or absence of classically conserved Golgi molecules featured in the expression of a Golgi apparatus. Previous studies concluded no Golgi expression via light microscopy and transmission electron microscopy, but a recent report on Naegleria gruberi indicated the presence of dispersed Golgi tubules. Non-pathogenic species of the Naegleria genus such as Naegleria gruberi 30540 and Naegleria lovaniensis 30569 were utilized in Western immunoblot analysis compared to reduced whole-cell lysate proteins of two strains of N. fowleri and …

Analyzing Interactions Between Methcathinone Analogs And The Human Monoamine Transporters, Vy Nguyen

Theses and Dissertations

Psychostimulants elicit their psychological and behavioral effects through interactions with the monoamine transporters. These compounds are classified as either substrates or reuptake inhibitors, depending on their mechanism of action, and have varying potencies at the three human monoamine transporters, hDAT, hSERT, and hNET. Substrates and reuptake inhibitors also have distinct electrophysiological signatures: reuptake inhibitors cause hyperpolarization in HEK293 cells stably expressing the monoamine transporters, whereas substrate transport mediates a depolarizing current. Recent studies have shown that substrate-mediated depolarization is sufficient to activate L-type calcium channels, a characteristic which has been used to develop a novel calcium assay which uses calcium …

Metal Nanoparticle Synthesis By Photochemical Reduction With A High-Intensity Focused Laser Beam, Victoria K. Meader

Theses and Dissertations

Colloidal, metallic nanoparticles have myriad applications, but they are most ideal when they are monodisperse, and demonstrate maximum catalytic utility when they are small (< 5 nm) and uncoated; because their surface area is accessible and maximized. Laser- assisted metal nanoparticle synthesis is a ‘green’ method that has become a topic of active research because it is able to produce uncoated or ‘naked’ products. The nanoparticles synthesized in this work were formed through the reduction of metal salts in aqueous solutions; but the reducing agent is an electron-dense microplasma generated by the laser pulse interacting with the media. Because no chemical reducing agents or stabilizers are needed, the products have no surfactants.

The underlying reaction mechanisms that drive this type of synthesis are generally understood, however, there is insufficient detail that would allow control over the formation of ultimate product morphologies and size distributions. The metals examined in this thesis are: gold, whose formation follows an autocatalytic rate law; and silver, whose formation follows a first-order rate law. Through my research, I was able to …

Eralpha Isoforms Modulate The Tumorigenicity Of 24r,25(Oh)2d3 In Estrogen-Responsive Cancer, Anjali Verma

Theses and Dissertations

Over 200,000 cases of breast cancer are diagnosed every year. Nearly 20% of these patients supplement their diets with some form of vitamin D. This high frequency of vitamin D supplement use may be due in part to research suggesting that cancer patients with higher serum vitamin D₃ levels have better prognoses than patients with low serum vitamin D_3. However, double-blind clinical trials on the efficacy of vitamin D₃ supplementation in breast cancer have been inconclusive. A recent meta-analysis showed evidence of reduced cancer recurrence in patients taking vitamin D₃ supplements who had ‘estrogen receptor positive’ …

Cyclophilin A As A Molecular Switch Regulating Prolactin Receptor Mediated Signaling, Mammary Tumorigenesis And Metastasis, Shawn Hakim

Theses and Dissertations

Prolactin (PRL) and its receptor (PRLr) have been implicated in the development and progression of human breast cancer. PRL activates its receptor and induces activation of proximal Janus kinase 2 (Jak2) for signal transduction. Here, we sought to determine the role of PRLr-associated peptidyl-prolyl isomerase, cyclophilin A (CypA), in modulating structure/function relationships of the PRLr. It was demonstrated that CypA mediated PRL-induced conformational change of the CFP- and -YFP tagged forms of the PRLr cytoplasmic-tail, whereas CypA inhibition by NIM811 (N-methyl-4-isoleucine cyclosporin) or knockdown blocked the conformational change of the PRLr assessed by Fluorescence Resonance Energy Transfer (FRET) signal or …

Sensor Placement For Damage Localization In Sensor Networks, Fereshteh Firouzi

Theses and Dissertations

The objective of this thesis is to formulate and solve the sensor placement problem for damage localization in a sensor network. A Bayesian estimation problem is formulated with the time-of-flight (ToF) measurements. In this model, ToF of lamb waves, which are generated and received by piezoelectric sensors, is the total time for each wave to be transmitted, reflected by the target, and received by the sensor. The ToF of the scattered lamb wave has characteristic information about the target location. By using the measurement model and prior information, the target location is estimated in a centralized sensor network with a …

Preconditioning Of The Tumor Microenvironment By Means Of Low Dose Chemotherapies For An Effective Immunotherapy Of Breast Cancer, Hussein F. Aqbi

Theses and Dissertations

Breast cancer mortality is mainly due to distant recurrence of the disease arising from dormant tumor cells established by cancer therapies. Patients who initially respond to cancer therapies often succumb to distant recurrence of the disease. It is not clear why people with the same type of breast cancer respond to treatments differently; some escape from dormancy and relapse earlier than others. In addition, some tumor clones respond to immunotherapy while others do not. We investigated how autophagy plays a role in accelerating or delaying recurrence of neu overexpressing mouse mammary carcinoma (MMC) following adriamycin (ADR) treatment, and in affecting …

Dating Violence And Latina/O Emerging Adult’S Attitudes Towards Condoms And Condom Use Behaviors: Examining The Role Of Culture, Melissa Avila

Theses and Dissertations

Latina/o emerging adults living in southern states may be especially at risk of being disproportionately affected by HIV. In 2015, Latina/os aged 20 to 24 accounted for 14.7% of all 20-24-year old’s living with HIV in southern states, despite the fact that 20 to 24-year-olds make up 3.7% of the region’s overall population of individuals living with HIV (CDC, 2016; U.S. Census Bureau, 2017). Specifically, there continues to be groups of Latina/o emerging adults who do not use condoms when they are sexually active and who are not using condoms consistently. Condom use literature suggests that relationship factors, such as …

The Role Of Cellular Aging In The Regulation Of Free Fatty Acid Induced Cellular Inflammation By Liver X Receptor Alpha, Charles S. Schwartz

Theses and Dissertations

Purpose: This study examined the impact of an acute bout of exercise on LXRα mRNA expression in isolated PBMCs from aerobically fit middle-aged males, and its associations with cellular inflammation. Furthermore, association between cellular age and LXRα were investigated. Methods: LXRα mRNA, plasma free fatty acids, IL-6, and MCP-1 responses were quantified following acute moderate intensity exercise and throughout recovery. To examine LXRα’s associations with cellular inflammation, PBMCs were stimulated with palmitate. Finally, telomere length was quantified as an indicator of cellular age. Results: LXRα mRNA expression was reduced at 90 minutes of recovery and did not influence systemic inflammation. …

Fabrication Of Nanoporous Electrodes For Sensing Applications, Md Rezaul Karim Khan

Theses and Dissertations

Fabrication of nanoporous electrodes for sensing applications

By Md Rezaul Karim Khan, Ph.D.

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

Virginia Commonwealth University, 2019. Major Director: Dr. Maryanne M. Collinson

Professor of Chemistry

The focus of this dissertation work is the fabrication of nanoporous electrodes and the study of their chemical and physical properties. The fabrication routes involved one or more of the following strategies: dealloying or chemical corrosion, co-electrodeposition, physical vapor deposition, and metal ions reduction. The work was not only restricted to the synthesis of …

Democratic Education And An Urban Teacher Residency: A Case Study, Bryan P. Arnold

Theses and Dissertations

Over the course of American schooling scholars note that democratic education and citizenship have not been abandoned, but perhaps marginalized or pushed aside, as test scores and achievement have become the most desired outcomes. Democratic education must move out of the margins and into high priority. The current political climate of increased division and divisiveness could not illustrate this need any more. Another well-documented challenge within the American educational system, particularly in high need areas is the need for highly qualified teachers. Urban Teacher Residency (UTR) programs have offered a possible solution to this growing problem in recruiting, training, and …

Mathematics Identity Construction In Successful African Americans: Reflections On Mathematics Experiences During Adolescence, Teri N. Johnson

Theses and Dissertations

This project used narrative inquiry to examine adolescent experiences that contributed to the development of positive mathematics identities in successful African Americans. Ten African Americans, who had worked in a STEM-related occupation for at least two years, were asked to reflect on in- and out-of-school experiences with mathematics during their middle and high school years. Data collection included individual interviews and one focus group discussion. A combination of internal and external factors emerged as contributors to participants’ adolescent mathematics identities. Internal factors included early career interest, finding enjoyment in the challenges associated with learning mathematics, or facing setbacks they were …

Modulation Of Autophagy And Senescence To Enhance The Response To Therapy In Triple Negative Breast Cancer, Liliya Tyutyunyk-Massey

Theses and Dissertations

Abstract

Although great strides have been made over the decades in development and optimization of anti-cancer therapies, even highly effective drugs often fail to completely eliminate tumors. Residual tumor cells can enter into a state of dormancy for prolonged periods of time but eventually are able to regain proliferative capacity and reemerge as chemotherapy-resistant disease. Because recurrent disease is a leading contributor to patient’s mortality, it is paramount to identify strategies for effectively destroying residual tumor cells.

Cytotoxic drugs and ionizing radiation are used as standard therapies in a variety of cancers. These modalities induce apoptosis, autophagy and senescence. Senescence …

Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin

Theses and Dissertations

Lethal interactions between carnivorans (interspecific killing) may influence their population dynamics, behavior, and other important aspects of their ecology. In this study, I expand upon previous research on the broad-scale patterns of interspecific killing in Carnivora (Palomares & Caro 1999, Donadio & Buskirk 2006) with a greatly expanded dataset (inclusion of scat and stomach data and more intensive sampling of the literature), and suggest avenues for future research. While like previous studies, I found a positive effect of relative body size between killer species and killed species on the likelihood of forming a killing interaction, I failed to find evidence …

2nd Tier Assay For The Detection Of Congenital Adrenal Hyperplasia By Virginia’S Newborn Screening Laboratory: Steroid Profile By Hplc-Ms/Ms, Christopher E. Nixon

Theses and Dissertations

Congenital Adrenal Hyperplasia (CAH) encompasses several disorders related to disruptions in the adrenal steroid production pathway. These disruptions may cause virilization of the external female sex organs, incorrect gender assignment, precocious puberty, and in the most severe form, may cause life-threatening salt wasting and adrenal crisis if not detected and treated early in the newborn period.

17α-Hydroxyprogesterone (17-OHP) is the primary target for immunofluorescence detection of CAH from dried blood spots in newborn screening (NBS). Unfortunately, current immunoassay techniques for the detection of CAH suffer from high false positive rates. The primary factors contributing to false positive determinations can include …

Undergraduate Students' Attitudes About The Collection, Use, And Privacy Of Search Data In Academic Libraries, Laura W. Gariepy

Theses and Dissertations

The purpose of this study was to understand undergraduate students’ attitudes about search data privacy in academic libraries and their preferences for how librarians should handle information about what students search for, borrow, and download. This is an important area of study due to the increasingly data-driven nature of evaluation, accountability, and improvement in higher education, along with libraries’ professional commitment to privacy, which has historically limited the amount of data collected about student use. Using a qualitative approach through the lens of interpretive description, I used the constant comparative method of data collection and analysis to conduct semi-structured interviews …

The Role Of Strength: Navigating Perinatal Loss Among Black Women, Ashley N. Hill

Theses and Dissertations

In the U.S., Black mothers experience fetal and infant mortality at alarming rates when compared to White and Latina mothers (Gregory, Drake, & Martin, 2018). The intent of this study was to examine perinatal loss among Black American women and to expand understanding of how the Strong Black Woman (SBW) ideology influences bereavement. Data were gathered from (N=109) Black American bereaved mothers. It was predicted that endorsement of differing aspects of the SBW would moderate the relationship between perinatal grief and psychosocial outcomes (i.e., depression and post-traumatic growth). Regression analyses, alongside a bootstrapping procedure via PROCESS (Hayes, 2017), …

Toward Liveness: The Polytemporality Of Performance Objects, Tracy Stonestreet

Theses and Dissertations

In this dissertation, I examine the temporal and material connections between component parts of hybrid artworks, specifically between live events / acts of performance and the long-lasting sculptural elements that those events / performances produce. I propose a re-orientation of the temporal gaze of performance art history, from one oriented to the past to one focused on the continually unfolding present. Such a re-orientation requires a nonlinear approach to art making that complicates set boundaries of past and present, liveness and record, and presence and absence, and disrupts in potentially corrective ways our historically normative systems of looking, categorizing, and …

Stat5b And Stat5 Tetramers Are Essential For Ige-Mediated Mast Cell Function, Kasalina N. Kiwanuka

Theses and Dissertations

Signal Transducers and Activators of Transcription (STATs) are latent transcription factors that mediate several cellular responses. This protein family consists of seven members, STAT1 – 6 including two closely related molecules, STAT5a and STAT5b, that show 96% amino acid sequence homology and are critical for lymphoid, myeloid and erythroid cell development and function. Activated STAT proteins dimerize and translocate to the nucleus, where they bind to high-affinity DNA motifs to modulate gene expression. We recently identified STAT5b as the critical regulator of IgE-mediated cytokine production in mast cells. STAT5b knockout (KO) cells show decreased sensitivity to IgE-mediated passive systemic anaphylaxis …

The Implied Editor: A Theory Of Craft And Poetics, Mary Selph

Theses and Dissertations

This dissertation advances a new theory of the editor. Editors are pervasively influential for shaping our evaluations of all kinds of work, from literature, to news, to scholarship, and beyond. I test my theory on editorial influence in little magazines, providing close readings, recovering historical contexts, and identifying a wide variety of rhetorical affordances available to little magazines’ editors. I draw on rhetorical narrative theory, most especially the “implied author” concept, which I build on in order to theorize an “implied editor.” I furthermore demonstrate that understanding the authored and edited texts as distinct is important for teasing apart the …

Phenotypic Characterization Of Pnpase Mutation And Overexpression In C. Elegans, Brian J. Hur

Theses and Dissertations

PNPase, polynucleotide phosphorylase, is a multifunctional exoribonuclease protein with 3` terminal oligonucleotide polymerase activity. Coded by the PNPT1 gene, the protein is associated with mitochondrial homeostasis and functions as a possible target for cancer therapy. In this study, C. elegans was used to investigate the effect of mutation and overexpression of pnpt-1, the gene that encodes PNPase. It was determined that two specific mutations in pnpt-1 did not affect PNPase expression nor did they produce deleterious phenotypes that affected polycistronic transcript accumulation or ROS production. Creation of a stable overexpression model was achieved through Fusion PCR. However, different transgenic …

An Evaluation Of Differences In Motivations To Receive Cervical Cancer Screening And Follow-Up Care Between Black And White Women, Ashlee Sawyer

Theses and Dissertations

Background: Cervical cancer among Black women is a major individual and public health concern. Despite advancements in medical technology and policy, disparities in cervical cancer diagnosis and mortality still exist between White and Black women, with Black women having higher rates of diagnosis (10.0 vs 7.1 per 100,000) and mortality (4.1 vs 2.0 per 100,000). Previous studies have focused heavily on barriers to obtaining cervical cancer screening among Black women and efforts to improve screening rates. Despite speculation by researchers that gaps in receipt of quality follow-up care may contribute to disparities, its role in disparate mortality rates between Black …

Why Women Give To Women: A Portrait Of Gender-Based Philanthropy, Amy C. G. Beck

Theses and Dissertations

Abstract

WHY WOMEN GIVE TO WOMEN: A PORTRAIT OF GENDER-BASED PHILANTHROPY AT A PUBLIC COLLEGE IN VIRGINIA

By Amy Gray Beck, Ph.D.

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

Virginia Commonwealth University, 2019

Chair: Katherine Cumings Mansfield, Ph.D., Associate Professor, Educational Leadership and Cultural Foundations, School of Education, UNC Greensboro

The cost of public higher education is steadily increasing, with state and federal government cutting its support year after year. Students are having to pay more out of pocket for classes and tuition, and institutions rely on …