Digital Commons Network^™

Evaluating The Acute Effect Of Vaping On Food Intake, Gabrielle Maldonado

Theses and Dissertations

Background: Weight control is a common motive for continued cigarette smoking, and weight concerns pose a barrier to quitting. These effects are driven in part by nicotine’s ability to reduce overall appetite and ultimately body weight. Electronic nicotine delivery systems (ENDS) have been marketed and used for weight control, suggesting that the use of these products potentially may share similar effects as well as barriers to quitting as observed for cigarette smoking. However, little to no controlled clinical lab evidence exists supporting ENDS use for weight control. The present study tested the influence of an ENDS on acute eating behavior …

A Learning Health System For Radiation Oncology, Rishabh Kapoor

Theses and Dissertations

The proposed research aims to address the challenges faced by clinical data science researchers in radiation oncology accessing, integrating, and analyzing heterogeneous data from various sources. The research presents a scalable intelligent infrastructure, called the Health Information Gateway and Exchange (HINGE), which captures and structures data from multiple sources into a knowledge base with semantically interlinked entities. This infrastructure enables researchers to mine novel associations and gather relevant knowledge for personalized clinical outcomes.

The dissertation discusses the design framework and implementation of HINGE, which abstracts structured data from treatment planning systems, treatment management systems, and electronic health records. It utilizes …

Exploring Polyamorous Relationship Experiences Of Lesbian, Gay, Bisexual, And Pansexual Individuals, Jiale Man

Theses and Dissertations

Polyamory is a type of relationship under the consensual non-monogamy relationship umbrella that assumes the possibility, validity, and worthwhileness of maintaining romantic, sexual, and intimate relationships with multiple people simultaneously. In Western society, the prevalence and domination of mononormativity have led to the marginalization of relationships alternative to monogamy (i.e., polyamory). As a result, individuals in polyamorous relationships continue to experience bias, stigma, and discrimination at varying levels. With a rise in public interest in CNM in the past two decades, scientists and researchers have slowly started to examine various topics related to CNM, including its prevalence, public attitudes toward …

Exploring The Relationship Between The Epigenome And Metabolism In Mycn-Amplified Neuroblastoma, Krista M. Dalton

Theses and Dissertations

High risk neuroblastoma (NB) is responsible for nearly 15% of all cancer related deaths in the pediatric population. The transcription factor MYCN is the most studied oncogene in NB, automatically conferring high-risk and has been found to be difficult to target. One way that MYCN amplification in NB functions to support tumorigenicity is through altered metabolism, satisfying the demand for rapid proliferation by increasing the nutrient flux through biosynthetic pathways. We performed an unbiased screen on select metabolic targeted therapy combinations and correlated sensitivity with over 20 subsets of cancer. We found that MYCN-amplified NB is hypersensitive to the …

The Effect Of Mild Traumatic Brain Injury On Perineuronal Nets Surrounding Neocortical Parvalbumin Interneurons, Olivia Lowman

Theses and Dissertations

Mild traumatic brain injury (mTBI) is an extremely common affliction with an estimated 42 million people being affected by it worldwide each year. It can lead to a range of long-term chronic issues and the underlying pathology is not well understood. Several previous studies have shown that parvalbumin inhibitory interneurons (PV+) are injured during TBI, therefore altering the excitatory to inhibitory ratio in neural networks which can lead to several neurodegenerative disorders such as epilepsy. Perineuronal nets (PNNs) are an extracellular matrix element that preferentially surround PV+ neurons in the neocortex and are recently thought to have important roles in …

How Do Early Interventionists Adapt Instruction When Delivering Services In Natural Environments?, Brian C. Wysong

Theses and Dissertations

Early Interventionists (EIs) play a pivotal role in supporting development for young children with disabilities. It is vital that they are able to support child and family outcomes through building strong partnerships with families, utilizing best practices, and individualizing services to children and families. The purpose of this study was to explore early interventionists’ perceptions regarding how they adapted instruction when delivering services in natural environments. Specifically, this study aimed to understand how changes in the child’s skill level, interests, and level of engagement affected early interventionists’ decision-making process during service delivery. A qualitative research design was employed, utilizing semi-structured …

Machine Learning Models To Automate Radiotherapy Structure Name Standardization, Priyankar Bose

Theses and Dissertations

Structure name standardization is a critical problem in Radiotherapy planning systems to correctly identify the various Organs-at-Risk, Planning Target Volumes and `Other' organs for monitoring present and future medications. Physicians often label anatomical structure sets in Digital Imaging and Communications in Medicine (DICOM) images with nonstandard random names. Hence, the standardization of these names for the Organs at Risk (OARs), Planning Target Volumes (PTVs), and `Other' organs is a vital problem. Prior works considered traditional machine learning approaches on structure sets with moderate success. We compare both traditional methods and deep neural network-based approaches on the multimodal vision-language prostate cancer …

Model-Based Imputation Of Below Detection Limit Missing Data And Group Selection In Bayesian Group Index Regression, Matthew Carli

Theses and Dissertations

Investigations into the association between chemical exposure and health outcomes are increasingly focused on the role of chemical mixtures, as opposed to individual chemicals. The analysis of chemical mixture data required the development of novel statistical methods, one of these being Bayesian group index regression. A statistical challenge common to all chemical mixture analyses is the ubiquitous presence of below detection limit (BDL) data. We propose an extension of Bayesian group index regression that treats both regression effects and missing BDL observations as parameters in a model estimated through a Markov Chain Monte Carlo algorithm that we refer to as …

Selected Problems In Graph Coloring, Hudson Lafayette

Theses and Dissertations

The Borodin–Kostochka Conjecture states that for a graph G, if ∆(G) ≥ 9 and ω(G) ≤ ∆(G) − 1, then χ(G) ≤ ∆(G) − 1. We prove the Borodin–Kostochka Conjecture for (P5, gem)-free graphs, i.e., graphs with no induced P5 and no induced K1 ∨P4.

For a graph G and t, k ∈ Z+ at-tone k-coloring of G is a function f : V (G) → [k] such that |f(v) ∩f (w)| < d(v,w) for all distinct v, w ∈ V(G). The t-tone chromatic number of G, denoted τt(G), is the minimum k such that G is t-tone k-colorable. For small values of t, we prove sharp or nearly sharp upper bounds on the t-tone chromatic number of various classes of sparse graphs. In particular, we determine τ2(G) exactly when mad(G) < 12/5 and also determine τ2(G), up to a small additive constant, when G is outerplanar. Finally, we determine τt(Cn) exactly when t ∈ {3, 4, 5}.

The Living Legends Of Sholoukh – شلوخ الأساطير Facial Scarification In Sudan, Ayah S. Elnour

Theses and Dissertations

Sholoukh — ritual face scarring—is a dying art form in Sudan.

Used to distinguish members of one tribe from another,

Sholoukh reflects the tribal pride of an individual. In the past,

sholoukh was seen as important as having a passport for a tribe

member, however, it was not always applied by choice. Using

just a razor blade, the wisest, most senior tribal elder would scar

the face of a child, initiating them into the tribe for life.

As this tribal art form fades away, the dwindling Sholoukh-bearers

have become living legends in Sudan. To honor them, I create

a collage …

Kpt-330 Synergizes With Everolimus To Reduce Mtorc1-Overactive Basal-Like Triple-Negative Breast Cancer Brain Metastasis Burden, Aaron D. Valentine

Theses and Dissertations

Triple-negative breast cancer (TNBC), a highly metastatic breast cancer subtype, accounts for approximately 20% of all breast cancer diagnoses. Basal-like TNBC is notably difficult to treat due to the lack of actionable drug targets such as estrogen and progesterone receptors, as well as HER2. Due to the deficiency in TNBC-targeting drugs that are able to cross the blood-brain barrier (BBB) for breast-to-brain metastasis, there is a need to develop novel BBB-permeable treatments. After preliminary testing, KPT-330 (XPO1 inhibitor) and everolimus (FKBP1A/mTOR inhibitor) were selected as drug candidates for this study. Patient-derived xenograft (PDX) models for in vitro and in vivo …

Portable Robotic Navigation Aid For The Visually Impaired, Lingqiu Jin

Theses and Dissertations

This dissertation aims to address the limitations of existing visual-inertial (VI) SLAM methods - lack of needed robustness and accuracy - for assistive navigation in a large indoor space. Several improvements are made to existing SLAM technology, and the improved methods are used to enable two robotic assistive devices, a robot cane, and a robotic object manipulation aid, for the visually impaired for assistive wayfinding and object detection/grasping. First, depth measurements are incorporated into the optimization process for device pose estimation to improve the success rate of VI SLAM's initialization and reduce scale drift. The improved method, called depth-enhanced visual-inertial …

Community On Campus: Examining The Impact Of Campus Climate, Belonging, And Flourishing On Bystander Behavior Among Diverse University Students, Amelia Liadis

Theses and Dissertations

This exploratory, nonexperimental study aimed to investigate the relationships among diverse undergraduate and graduate students’ perceived campus climate, flourishing, and university belonging on bystander intentions and bystander behaviors during the COVID-19 pandemic. The study’s theoretical framework combined the Theory of Planned Behavior and feminist theory, and examined intersectionality through an Identity Risk Index. Data used in the current study were originally collected as part of an institutional Healthy Minds Survey, on health behaviors of college students; responses from n = 171 of the randomly selected participants were used in the current study’s analyses. The majority of participants indicated at least …

Effects Of Slip On Highly Viscous Thin-Film Flows Inside Vertical Tubes (Constant Radius, Constricted And Flexible), Mark S. Schwitzerlett

Theses and Dissertations

Viscous liquid film flows in a tube arise in numerous industrial and biological applications, including the transport of mucus in human airways. Previous modeling studies have typically used no-slip boundary conditions, but in some applications the effects of slip at the boundary may not be negligible. We derive a long-wave model based on lubrication theory which allows for slippage along the boundary. Linear stability analysis verifies the impact of slip-length on the speed, growth rate, and wavelength of the most unstable mode. Nonlinear simulations demonstrate the impact of slip-length on plug formation and wave dynamics. These simulations are conducted for …

“It's Just Not Enough”: Examining The Experiences Of School-Based Sexual Health Education And Conversation Engagement With Trusted Adults Among Black Boys In Richmond, Va, Sharyn A. Dougherty

Theses and Dissertations

The Centers for Disease Control and Prevention estimate that youth make up a quarter of the sexually active population, yet account for half of the 20 million new sexually transmitted infections in the United States.In 2021, youth age 15-19 living in Virginia’s central region, which includes the Richmond Metropolitan area, had the second highest number of chlamydia cases and fourth highest number of gonorrhea cases among all age groups, with the highest rates among Black youth. The aim of this study is to explore the experiences of Black youth in Richmond, VA with school-based sexual health education (SHE) and their …

Rainbow Turan Methods For Trees, Victoria Bednar

Theses and Dissertations

The rainbow Turan number, a natural extension of the well-studied traditional
Turan number, was introduced in 2007 by Keevash, Mubayi, Sudakov and Verstraete. The rainbow Tur ́an number of a graph F , ex*(n, F ), is the largest number of edges for an n vertex graph G that can be properly edge colored with no rainbow F subgraph. Chapter 1 of this dissertation gives relevant definitions and a brief history of extremal graph theory. Chapter 2 defines k-unique colorings and the related k-unique Turan number and provides preliminary results on this new variant. In Chapter 3, we explore the …

Coming Out To Treatment: Identifying Facilitators & Characterizing Experiences Of Sexual And Gender Minoritized Individuals In Opioid Use Disorder Treatment Before And During The Covid-19 Pandemic, Jaclyn S. Sadicario

Theses and Dissertations

Sexual and Gender Minority (SGM) individuals are disproportionately impacted by substance use disorders vs. their non-SGM counterparts. Additionally, SGM folks face more barriers to access for treatment than others due to minority stressors including discrimination, internalized stigma, and marginalization related to their sex and gender minority statuses. It is important for researchers and treating providers alike to understand how these different factors are impacting the treatment of substance use disorders in SGM populations. With this in mind, this two phase study employed a mixed-methods approach to (1) describe the population of SGM folks enrolled in a MOUD treatment program with …

The Influence Of The Covid-19 Pandemic On Rural Virginia Secondary Teachers’ Self-Efficacy, Sherol L. Southerland

Theses and Dissertations

The COVID-19 pandemic has presented unique challenges for PK-12 education and exposed educators’ skill deficits. Teachers had to learn new approaches to doing their jobs while navigating the mental, emotional, spiritual, and financial impact of the pandemic on their personal lives. This undertaking was even more demanding for rural school divisions, which tend to lack the resources (e.g., personnel, technology, financial) that suburban and urban school divisions have. Schools reopened in fall 2020 offering fully remote, fully in-person, and hybrid modalities, however, there was no going back to teaching as it was before the pandemic. The present study sought to …

Grounded In Teachers’ Reality: A Collective Case Study On Middle School Teachers’ Self-Efficacy For Equity-Centered Trauma-Informed Educational Practices, Margaret Wallace

Theses and Dissertations

The current body of literature clearly demonstrates the high prevalence of student trauma and the significant impact of trauma on adolescents' well-being and academic outcomes. Middle school teachers are uniquely positioned to support adolescents experiencing trauma using trauma-informed educational practices (TIEP), however, more work is needed to understand their self-efficacy beliefs for using TIEP. Thus, the purpose of this qualitative collective case study is to explore middle-school teachers' self-efficacy (TSE) beliefs for trauma-informed educational practices particularly as they relate to centering equity, and what factors impact those beliefs. Specifically, my study asks the following research questions, (1) How do middle …

Studying Gene Function In Streptococcus Sanguinis Using Rna-Sequencing Analysis, Ahmed Ismail

Theses and Dissertations

The oral cavity hosts hundreds of bacterial species, amongst them are the Streptococci family. More specifically, S. sanguinis is a benign bacteria in the oral cavity to protect the tooth surface from S. mutans. which is a pathogen causing dental caries. While S. sanguinis is harmless in the oral cavity, it becomes pathogenic once entering the bloodstream and causing Infective Endocarditis (IE). To further study S. sanguinis and eventually develop an effective drug to treat IE caused by S. sanguinis, a gene expression study was conducted. In order to study gene expression, RNA-sequencing was conducted, and appropriate methods to remove …

Exploration Of Dimensional Structure Of Major Psychiatric Disorders Reveals Relationship With Substance Use And Personality, Noah Berley

Theses and Dissertations

Objective: Using a mixture of statistical techniques like structural equation modeling, confirmatory, and exploratory factor analyses, we aimed to determine the genetic factor structure among Externalizing, Internalizing, and Psychotic spectrum disorders through methods that evaluate GWAS-based correlations. Additionally, a subsequent factor analysis based on the most suitable psychiatric model was conducted to understand how non-clinical behavioral traits align with this factor structure.

Methods: Publicly available GWAS summary statistics for twelve major psychiatric disorders, six substance use measures and two personality domains were incorporated into structural equation models. Using the GenomicSEM software package, GWAS-based correlations were estimated between all twelve disorders …

Examining The Home Interventionist Model Of Care In Pediatric Asthma, Katherine D. Lohr

Theses and Dissertations

Pediatric asthma disproportionately affects children living in urban areas and within families reporting an income below the poverty threshold. Home interventionist models of care, utilizing interventionists from the communities they serve, have been found to improve pediatric asthma symptoms and reduce Medicaid costs. Home interventionists, such as community health workers (CHWs) and Healthy Homes assessors (HHAs), focus on connecting care among schools, providers, and homes, and empowering families in accessing resources to overcome barriers to care. However, research is just beginning to understand how home interventionists create positive change among families within low-income, urban communities. This dissertation study used a …

Evaluation Of Spliceai For Improved Genetic Variant Classification In Inherited Ophthalmic Disease Genes, Melissa Reeves

Theses and Dissertations

ABSTRACT

EVALUATION OF SPLICEAI FOR IMPROVED GENETIC VARIANT CLASSIFICATION IN INHERITED OPHTHALMIC DISEASE GENES

By Melissa Jean Reeves, 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, 2023

Major Director: Melissa Jamerson, PhD, MLS(ASCP)

Associate Professor, Department of Medical Laboratory Sciences

Inherited ophthalmic diseases impact individuals around the globe. Inherited retinal diseases (IRDs) are the leading cause of blindness in individuals aged 15 to 45. The personal, social, and economic impact of vision loss is profound. Due to individual differences, symptoms can be variable, and …

Improving The Use Of Diffusing Wave Spectroscopy As A Multiphase Process Analytical Technology, Robert Emerson Mcmillin Iii

Theses and Dissertations

The study of multiphase formulations is a difficult task due to inhomogene- ity. Typical methods of study, such as microscopy, suffer from sampling drawbacks and are ill-equipped at probing the system in its native state. Additionally, more concentrated sys- tems, including optically-dense emulsions and suspensions, render common light-scattering techniques, such as dynamic light scattering (DLS), useless. Lastly, macroscopic phase track- ing or transmission intensity techniques can only obtain partial information about a system. Herein, the use of diffusing wave spectroscopy (DWS), a multiple scattering adjunct to DLS, to study optically dense multiphase systems is explored. Three different systems are exam- …

Mechanistic Insight Into Traumatic Brain Injury Induced Neuronal Membrane Disruption: Cathepsin B Relocalization And A Neun Negative Cortical Neuron Subpopulation, Martina L. Hernandez

Theses and Dissertations

Traumatic brain injury (TBI) is a mechanical insult to the head that leads to brain damage and, in turn, causes long-term sensory, motor, cognitive, and affective dysfunction. Diffuse pathologies seen following such injury are associated with these life-altering outcomes that impact the daily lives of TBI survivors. The diffuse pathology that this body of work focuses on is neuronal membrane disruption; it is characterized by increased permeability of the neuron’s plasma membrane. Moreover, our lab had previously found that membrane disruption is exacerbated with intracranial pressure (ICP) elevation. We set out to measure the duration of membrane disruption following injury …

Characterizing 3-O-Sulfation-Induced Novel Compact Topologies In Heparan Sulfate And Their Interactions With Proteins, Samuel Holmes

Theses and Dissertations

Heparan sulfate (HS) is highly-charged, linear polysaccharide that interacts with numerous proteins in humans as consituents of proteoglycans. The action of sulfotransferase enzymes during the biosynthesis of HS can generate a combinatorially massive library of differentially sulfated sequences. Furthermore, the number and position of these sulfate groups are key to their biological activity, modulating their selectivities for certain proteins at the cell surface or ECM. The installation of a sulfate on the C3 hydroxyl of a glucosamine residue in HS represents the rarest of the sulfations, despite the HS 3-O-sulfotransferase (3OST) family being the most diverse of the other sulfotransferases. …

Fascism In Sci-Fi: "Mobilizing Passions" In Robert A. Heinlein's Starship Troopers, Alton C. Ayers

Theses and Dissertations

This thesis responds to criticism of Robert A. Heinlein’s Starship Troopers (1959) as a “fascist” novel by further investigating the claim through a close reading of the novel that applies political theory scholarship on fascism. Chapters I and II introduce the novel along with its general reception and controversy. These chapters consider the accusations of “fascism” given to the novel while at the same time understanding that a clear, exact definition of “fascism” has long been grappled with by scholars since the rise of the regimes in Nazi Germany and Fascist Italy. Chapters III and IV apply political theory to …

Supporting Students Who Are Deafblind To Increase Their Access To The General Education Curriculum Through Trained Interveners: A Mixed Methods Study, Ira Padhye

Theses and Dissertations

The purpose of this mixed-methods research study was to identify the educational trends of children and young adults who are deafblind and identify strategies to improve the outcomes through interviews of nationally qualified interveners who have received training in deafblind specific strategies. Secondary data from the 2017-2021 National Center on Deafblindness and interview transcripts were used for data analysis and then integrated to identify the supports students who are deafblind should access. Trends in age of identification, primary eligibility category, school settings and access to state standardized assessments showed a plateau and displayed no significant improvement in educational outcomes. Nationally …

Advanced Modeling And Innovative Transcranial Magnetic Stimulation Coil Designs For The Treatment Of Neurological Disorders, Mohannad Tashli

Theses and Dissertations

Transcranial magnetic stimulation (TMS) is a safe, effective and non-invasive treatment for several mental and psychiatric disorders. TMS is an FDA approved treatment and is commonly applied to patients who do not respond to medications for the treatment of clinical depression, smoking cessation, obsessive-compulsive disorder and migraine. Recently, there has been an increase in the development of electromagnetic neuromodulation techniques targeted at enhancing the effectiveness of TMS devices for the treatment of mental diseases. In TMS stimulation, focality is an important factor which determines the specificity of the pulses induced in different brain tissues. The electromagnetic pulses must be confined …

Activity Levels Of Different Cell Types In An Epileptogenic Model Of Cortical Microgyria: A Cfos Investigation, Peter F. Lamothe

Theses and Dissertations

A large percentage of individuals with intractable epilepsies have an accompanying cortical malformation, the underlying cellular mechanisms of which are not fully understood. In an animal model for one such malformation, polymicrogyria, epileptogenesis occurs most easily in a region of tissue just adjacent to the microgyria termed the paramicrogyral region (PMR). Previous studies implicate somatostatin containing interneurons (SOM) as a potential contributor to this pathology, and show increased excitation of SOM in the PMR. We hypothesis that SOM are more active in the PMR when compared to SOM within the homologous region of the control cortex. In addition to this …