Digital Commons Network^™

Interference Under Pressure: Task-Switching And Cognitive Control In Adhd, Rocio Belen Varela

Theses and Dissertations

Attention-Deficit/Hyperactivity Disorder (ADHD) is a widespread neurodevelopmental condition associated with significant academic difficulties, often resulting in students scoring a year below average on standardized examinations (Lawrence et al., 2020; Mohammadi et al., 2019). A proposed core feature of the disorder involves impairments in working memory (WM), specifically the Central Executive component responsible for attentional control (Alderson et al., 2013; Kofler et al., 2008). These WM operations are governed by two cognitive control modalities: proactive control (sustained, anticipatory maintenance) and reactive control (cue-driven, on-demand processing) (Braver et al., 2007). This quasi-experimental study investigated whether a natural tendency toward reactive control grants …

Program Evaluation: A Study To Evaluate A Traditional Suspension Program Versus An Alternate Suspension Program, Ruth Desronvil

Theses and Dissertations

In the United States, millions of students face out-of-school suspensions from public schools each year. Black and Hispanic students, in particular, are suspended at higher rates than their white peers (Cobb-Clark et al., 2015). Students miss class time and valuable learning, which widens the achievement gap between Black, Hispanic, and White students. Suspended students also face additional consequences, such as social alienation from schools and a higher likelihood of engagement in delinquency. Several programs seek to improve the effects of suspensions on students’ outcomes. In this dissertation response, I examine the effectiveness of one such program: an alternative suspension educational …

Don’T Hit Mommy! Associations Between Harsh Parenting And Aggression In Toddlerhood: The Moderating Role Of Temperament, Serah Betancourt

Theses and Dissertations

Physical aggression is known to be particularly common in toddlerhood. Further, harsh parenting practices and certain temperament traits in children have been found to be associated with aggressive behaviors. Recently, aggression has been demonstrated to be differentiated between provoked and unprovoked aggression. The current study examined early aggression and explored the mechanisms by which harsh parenting practices and temperament traits may predict different types of aggression and how that may also change depending on the stage of development in toddlerhood. That is, we proposed that harsh parenting would be more strongly associated with provoked aggression among toddlers with higher negative …

Vulnerable Narcissism In Borderline Personality Disorder: Impact On Emotion Dysregulation, Identity Disturbance, And Rejection Sensitivity In Psychiatric Inpatients, Lauren Baker Lloveras

Theses and Dissertations

Borderline personality disorder (BPD) is a severe personality disorder frequently seen in clinical settings due to high service utilization. It is characterized by emotion dysregulation, identity disturbance, suicidal behavior, fear of abandonment, and impulsive or risky behavior. BPD is categorized as a Cluster B personality disorder, alongside narcissistic personality disorder (NPD), which is defined by grandiosity, attention-seeking, and a lack of empathy. NPD can be further conceptualized across two subtypes: grandiose narcissism and vulnerable narcissism (VN). Unlike grandiose narcissism, VN has been largely neglected in research – despite overlapping features with personality and mood disorders, especially BPD. These shared features …

Umbralisib Antagonizes Multidrug Resistance In Abcb1- Overexpressing Cancer Cells, Letao Bo

Theses and Dissertations

Overexpression of ATP-binding cassette (ABC) transporters, particularly ABCB1, is a major mechanism of multidrug resistance (MDR) and contributes to chemotherapy failure by reducing intracellular drug accumulation. Umbralisib is a dual inhibitor of phosphoinositide 3-kinase delta (PI3Kδ) and casein kinase 1 epsilon (CK1ε) that was developed for the treatment of hematologic malignancies; however, it was later withdrawn due to safety concerns. In the present study, we found that umbralisib has the potential to reverse ABCB1-mediated MDR. The MTT assay demonstrated that umbralisib significantly sensitized ABCB1-overexpressing KB-C2 and SW620/Ad300 cells, as well as ABCB1-transfected HEK293 cells. Mechanistic assays revealed that umbralisib enhanced …

Prevention Of Inflammation-Associated Neurodegeneration: Assessing The Efficacy Of N,N-Dimethylacetamide (Dma) In Lipopolysaccharide (Lps)-Induced Neuroinflammation Using C57bl/6 Mice, Teeshavi Devi Acosta

Theses and Dissertations

Neurological function is closely linked to both longevity and quality of life. While some degree of neurodegeneration occurs naturally with aging, pathological neurodegeneration leads to devastating functional decline. The mechanisms underlying these processes remain incompletely understood; however, neuroinflammation is recognized as a key driver of neuronal dysfunction and death. Emerging evidence indicates that neuroinflammatory cascades can precede and potentiate hallmark features of neurodegenerative diseases, including synaptic loss and cognitive decline observed in Alzheimer’s disease (AD). Activation of the NF-κB signaling pathway contributes to amyloid beta (Aβ) peptide production, further amplifying a cycle of inflammation and neuronal injury. Preclinical work from …

Finding, Founding, And Forging: Queer Formulations Of Family In Nineteenth-Century British Novels, Brian Hicks

Theses and Dissertations

This dissertation examines how nineteenth-century British novels imagine and negotiate queer formulations of family at moments when biological kinship, marriage, and inheritance were increasingly formalized as social and legal imperatives. Reading canonical texts by Austen, Shelley, Wilde, Brontë, and Hardy, alongside the proto-modern and modernist work of Joseph Conrad and Virginia Woolf, I argue that these novels resist consanguinity as the sole basis of family and instead theorize queer kinship as something found, founded, or forged through affinity, care, and shared orientation rather than blood or reproduction. Drawing on queer theory, feminist criticism, phenomenology, and Foucauldian accounts of power and …

Reframing Sexual Assault And Intimate Partner Violence Through A Maternal And Child Health Lens: Implications For Integrated Prevention, Policy, And Practice, Daija C. Gibson

Theses and Dissertations

Sexual assault and intimate partner violence remain persistent public health concerns in the United States, with significant consequences for individual health, family stability, and population well-being. Although these forms of violence are frequently addressed through criminal justice and behavioral health frameworks, less attention has been given to their implications within maternal and child health, where relational dynamics, life course development, and intergenerational outcomes are central. This study reframed SA and IPV as core MCH issues to examine how integrated, systems-based approaches can strengthen prevention efforts. A structured literature review and systematic synthesis of peer-reviewed studies published between 2015 and 2026 …

Understanding Maternal Morbidity And Mortality Rates In Georgia, Ebony Hall

Theses and Dissertations

The United States continues to have a significant concern for public health regarding the maternal morbidity and mortality rates. In contrast, women of African American descent and other marginalized populations maintain a disproportionately higher rate of pregnancy-related disparities. More specifically, in Georgia, a persistent number of disparities can correlate to a lack of access to adequate prenatal care, insurance status, and many other social determinants of health that are linked to the contribution of adverse maternal health care outcomes. The purpose of this research study is to evaluate various maternal health experiences during pregnancy, while focusing on the occurrence of …

Child Maltreatment Risk Identification In Complex Caregiving Environments: A Public Health Review Of Split-Custody And Multi-Household Family Contexts, Makenzie Lee

Theses and Dissertations

Child maltreatment remains a significant public health concern with lifelong consequences for children's health, development, and well-being. As children's caregiving environments become increasingly diverse through split-custody arrangements, blended families, kinship care, and other multi-household contexts, recognizing and assessing child safety concerns may become more complex. Although these family structures are not inherently associated with maltreatment, the distribution of caregiving responsibilities and information across multiple households may complicate child maltreatment risk identification.

This capstone presents a scoping review of peer-reviewed literature examining child maltreatment risk identification within complex caregiving environments. The review synthesized evidence related to caregiving environments, caregiver relationships, child …

Substance Use Behaviors And Treatment Engagement In Individuals With Severe Psychopathology With And Without Comorbid Obesity, Rachel M. Madera-Arnold

Theses and Dissertations

Research has found significantly higher rates of both substance use and obesity among individuals with SMI compared to population samples which in turn can lead to worsening health outcomes. Despite this, there is limited research on the co-occurrence of obesity, substance use, and SMI and how these conditions may interact to affect patient outcomes. In addition, there are many gaps in the research regarding the relationship between substance use and body weight, appetite and/or eating behaviors. This study conducted a secondary analysis of the NSDUH 2021 survey that characterized substance use and disorders among individuals who had severe psychopathology, examined …

Family- And Cultural-Level Influences For Latine Adolescent Nicotine Use: A Qualitative Study Informing Prevention, Cindy M. Hernandez Castro

Theses and Dissertations

Early tobacco use among Latine adolescents represents a critical public health concern, with 23.8% reporting current use and exceeding rates among other racial/ethnic groups (Birdsey et al., 2023; Gaddy et al., 2022). This early initiation elevates risks for nicotine dependence and related morbidity in adulthood (Tsao et al., 2023). Guided by Structural Ecosystems Theory (Szapocznik & Coatsworth, 1999) and contemporary grounded theory analysis (Braun & Clarke, 2006; Charmaz, 2006; Noble & Mitchell, 2016), this study examined multilevel influences on nicotine-related attitudes among Latine youth, including: (1) familial factors (i.e., parental monitoring, caregiver-youth communication), (2) cultural dynamics (i.e., cultural values and …

Characterization Of Growth, Motility And C-Di-Gmp In Selenomonas Sputigena Atcc 35185, Margaret E J Stiker

Theses and Dissertations

Selenomonas sputigena is an obligate anaerobic, Gram-negative pathobiont that transitions from a low-abundance commensal bacteria to a structural component in dysbiotic oral biofilms associated with early childhood caries and periodontitis. Analysis of S. sputigena ATCC 35185 cultures optimized in TYGVS media revealed robust growth, characteristic crescent morphology with flagellar tuft motility, and strong monospecies biofilm formation comparable to Streptococcus mutans via crystal violet assays.

ELISA quantification demonstrated significantly elevated c-di-GMP levels in sessile biofilm fractions relative to motile planktonic cells (p=0.0009), establishing the secondary messenger’s correlation with the motile-sessile lifestyle switch. Recombinant expression and purification yielded PilZ-domain effector proteins, Selsp_1666 …

Environmental Monitoring In Shallow Lakes: Public Health Threats In Urban Waters, Kyleigh E. Johnson

Theses and Dissertations

Lakes are an integral part of urban and suburban communities, providing ecological, recreational, and public health benefits. Many of these lakes are located in densely populated areas and are subject to urban influences on water quality. Algal toxins and Escherichia coli are two common recreational concerns. Algal toxins come from harmful algal blooms that are influenced by nutrient availability and temperature, while bacteria are often introduced through run-off and animal waste. Sampling every 3-4 weeks from May-October 2025 allowed for the assessment of seasonal patterns and site-specific differences across nine lakes in the Richmond area. The highest bacterial concentrations appeared …

Mathematical Models With Clinical Applications For Improving Health Outcomes, Helen Harris

Theses and Dissertations

In clinical settings, patients are exposed to many risks and stressors that could result in adverse health outcomes. Here we present mathematical models that seek to address these risks. First, we present a Markov Chain model to investigate the effect of medication reconciliation (MR) completion on patient health outcomes in the intensive care unit. Using this model, we simulate the annual incidence of adverse drug events (ADEs) for three different ADE rates. Based on the simulated results, we conduct a cost-benefit analysis for various levels of compliance to determine the financial implications of increasing MR completion depending on the baseline …

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk

Theses and Dissertations

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance quality …

In Search Of The Soul Of Creativity: Authorship, Agency, And Meaning In Refractive Collaboration With Generative Ai, Fatima Nazir

Theses and Dissertations

When images can be generated in seconds, what remains uniquely human in the act of creation? In Search of the Soul of Creativity: Authorship, Agency, and Meaning in Refractive Collaboration with Generative AI investigates where authorship, agency, and meaning reside within design practices mediated by generative AI. Rather than using AI to produce predictable results, this research deliberately relinquishes control to observe how generative systems interpret language through their own learned associations. Through a practice-led investigation across four generative models within the Higgsfield platform, user prompts were progressively shortened from full sentences to single words, revealing recurring patterns and cultural …

Magnetic Resonance Only Planning Validation Using Synthetic Ct By Mvision, Eric D. Brass Sr

Theses and Dissertations

Problems: Adaptive radiotherapy requires clinically practical methods for responding to patient-anatomy changes that occur between the original planning images and the day of treatment delivery. Registering a previously acquired computed tomography scan to a newly acquired magnetic resonance image can introduce cross-modality uncertainty and may delay replanning. This thesis evaluates whether synthetic computed tomography generated from same-day magnetic resonance imaging can reduce registration-related uncertainty while supporting rapid dose recalculation for fraction-level adaptation.

Procedure: Magnetic resonance imaging DICOM data were exported from the ViewRay MRIdian treatment planning system and uploaded to MVision for synthetic computed tomography generation. The synthetic computed tomography …

The Ethereal Being That Is Me, And Maybe You, Hwiy Chang

Theses and Dissertations

The Ethereal Being That Is Me, and Maybe You is a 23-minute video collection of short stories accompanied by an installation at the Institute for Contemporary Art at Virginia Commonwealth University. This thesis explores the work’s creation as a visual and narrative meditation on self-transformation, drawing from personal experiences in therapy and philosophical texts including Carl Jung’s concept of the unconscious. The paper examines how each story represents a distinct stage of transformation—from recognizing patterns to confronting setbacks to reshaping internal dialogue—and how watercolor’s fluid, unpredictable nature serves as a visual metaphor for the process of change. The installation component …

Follow The Cyclists: Everyday Navigation Of Richmond's Bike Infrastructure, Emily E. Schreer

Theses and Dissertations

This thesis explores the embodied experience of cycling in Richmond, emphasizing the importance of centering firsthand, lived experience in cycling research and urban planning. While traditional transportation planning can often myopically prioritize efficiency and safety metrics to evaluate infrastructure, this project argues that such approaches overlook essential experiential, sensory, and emotional dimensions of cycling that determine how infrastructure is perceived, used, and ultimately succeeds or fails.

Through an ethnographic approach combining field observation of cyclist behavior and mental mapping sessions with Richmond cyclists, this study positions people who bike in Richmond as expert knowledge holders. Participant contributions, combined with observations …

A Mutant Perfect, Amelia R. Baxter

Theses and Dissertations

A Mutant Perfect examines how embodied knowledge can be made visible and transmissible through ceramic figures. The research asks what forms emerge when making is understood as a mode of thinking rather than a vehicle for pre-formed ideas, and how those forms might activate somatic recognition in a viewer. The primary method is coil-built ceramic sculpture. Color is applied in layered coats and removed by hand-sanding to expose varying strata beneath, producing a speckled, worn surface. In a second approach, pigment is built directly into the clay body through coil construction, making color structural rather than applied. Narrative prose and …

Characterization Of Microrna Expression In Neuron-Enriched Extracellular Vesicles During Early Life, Allison Molen

Theses and Dissertations

Extracellular vesicles (EVs) are membrane-bound sacs released by cells that carry molecular cargo reflective of their cell of origin. EVs enriched using L1 cell adhesion molecule (L1CAM) as a marker of putative neuronal origin can cross the blood–brain barrier and provide a minimally invasive window into brain-related processes. Exosomal microRNA (miRNA) regulate gene expression and have been implicated in psychiatric disorders, including major depressive disorder (MDD). However, measuring and analyzing miRNA from L1CAM-positive EVs presents substantial analytical challenges due to low abundance and sparse detection across samples.

Plasma samples from participants recruited through the Mid-Atlantic Twin Registry (MATR) were used …

Examining The Impact Of Trauma-Informed Mindfulness Meditation On Posttraumatic Growth Following Interpersonal Trauma: A Randomized Controlled Trial, Margaret Poandl

Theses and Dissertations

Research on interventions designed to increase posttraumatic growth (PTG) among interpersonal trauma survivors is limited. The purpose of this study was to examine the impact of a six-week trauma-informed mindfulness meditation intervention on PTG. Additionally, I examined outcomes of posttraumatic stress (PTS) and loneliness, as well as analyzed the variables of dispositional mindfulness, hope, spirituality, and self-compassion to understand their potential role as mechanisms of change within the intervention on PTG. To answer these research questions, I conducted a randomized controlled trial study with 113 adults from a community sample who reported experiencing interpersonal trauma. Utilizing linear mixed modeling and …

Commissioning & Daily Qa Of Converted Linac For Electron Flash, Tomaj Javidtash

Theses and Dissertations

Ultra-high dose rate (FLASH) radiotherapy has demonstrated promising normal tissue sparing in preclinical studies; however, the lack of standardized dosimetry, commissioning, and quality assurance (QA) methodologies remains a major barrier to its reproducible and safe implementation. In particular, conventional clinical commissioning and QA protocols are not directly applicable at FLASH dose rates due to challenges associated with detector response, dose-per-pulse effects, and beam control limitations.

This thesis presents the commissioning of a converted Varian 21EX linear accelerator for electron FLASH operation within the Division of Medical Physics at the Virginia Commonwealth University (VCU) Department of Radiation Oncology. Comprehensive beam characterization …

The Effects Of Overwash On Barrier Island Evolution And Building A Barrier Island Measure Of Resistance, Beth Thomas

Theses and Dissertations

Barrier islands are critical for coastal communities, as they serve as a natural buffer against storm surge, waves, and the effects of rising sea levels, protecting life and property. These islands continuously evolve due to both normal and severe environmental conditions; global warming makes it increasingly difficult to predict the evolution of these islands due to increases in storm frequency and intensity. We present a cellular model of barrier island evolution consisting of biotic and abiotic processes including the effects of vegetation, wind, ocean currents, and gravity. The model is used to predict the future evolution of barrier islands off …

Machine Learning-Based Spatio-Temporal Modeling Of Climate Dynamics And Desertification In The Sahara–Sahel Region, Stephen M. Tivenan

Theses and Dissertations

Arid climate classifications are threshold-dependent and easily interpretable mappings that are widely used in ecological, agricultural, and climate-related studies. These classifications inform scientific understanding, support policy and land management decisions, and provide an intuitive summary of environmental conditions. Despite their usefulness, traditional arid climate classifications often fail to quantify uncertainty, incorporate spatial context, or account for complex relationships among relevant environmental variables. Existing approaches to uncertainty assessment have largely relied on comparing classifications across multiple datasets or alternative formulas, but these methods generally overlook important spatial dependence and latent structure in the data.

This dissertation develops three machine learning-based statistical …

Teachers’ Perceptions Of The Decline In Reading Scores Among Fourth- And Fifth-Grade Students, Brigetta Foules-Sims

Theses and Dissertations

The purpose of this qualitative instrumental case study was to explore teachers’ perceptions of the factors contributing to the decline in reading achievement among fourth- and fifth-grade students in a rural elementary school in a southern state. The study explored teachers’ perceptions of the causes of declining reading performance, the instructional challenges they encounter when addressing reading difficulties, and the resources and supports they believe are necessary to improve student outcomes.

Data were collected through semi structured interviews with eight certified fourth- and fifth-grade teachers. Five themes emerged from the data: (a) increasing academic demands reveal foundational reading gaps, (b) …

Dimension Reduction Involving Exogenous Variables With Applications In Manufacturing And Healthcare, Linxi Li

Theses and Dissertations

High-dimensional data analysis presents diverse challenges, including the curse of dimensionality, the complexities of working with datasets that combine large feature spaces with limited sample sizes, and difficulties in identifying meaningful relationships among variables. As datasets grow in size and complexity across different fields, it is increasingly important to develop practical approaches for extracting essential information from such data. Dimension reduction methods address these challenges by alleviating the effects of high dimensionality, enhancing the ability to reveal hidden patterns, and uncovering latent structures within the data to support further analysis. Some methods reduce dimensionality while preserving all relevant information, offering …

Towards Sample-Efficient Deep Reinforcement Learning, Guang Yang

Theses and Dissertations

Deep reinforcement learning (DRL), combining reinforcement learning and high-performance function approximations such as deep neural networks (DNN), is a powerful approach to solving complex sequential decision-making problems. However, due to the complex solution space of the sequential decision-making problems and the inefficient design of the DRL algorithms, DRL algorithms usually require a prohibitively large number of data samples to train effective strategies. Consequently, it is difficult to apply these DRL algorithms to complex real-world problems that require high costs to collect a large volume of data samples. This dissertation proposes new mechanisms to address this sample inefficiency issue, realizing sample-efficient …

Gz17.602, A Combination Of Three Nutraceuticals, Interacts With Carboplatin And Etoposide To Kill Neuroblastoma, Michael R. Booth

Theses and Dissertations

This study examined the efficacy of GZ17.602, a combination of Harmine, Isovanillin, and Curcumin as a therapeutic for MYCN-amplified Neuroblastoma, both alone and in combination with standard of care chemotherapeutics. This was done due to the low survival rate associated with these neuroblastomas, the large degree of morbidity associated with current treatments, previous experiments in the Dent lab having shown 602 as effective for killing cancers of other types, and the current lack of understanding of the biology of GZ17.602 in solid pediatric cancers. Due to the GZ17.602 components being present at different concentrations in tumors than those administered, the …