Digital Commons Network^™

Paley Graphs, Prime Graphs, And Crossword Puzzles, Robert D. Jacobs Jr.

Theses and Dissertations

In this paper, we will talk about many different mathematical concepts. We will prove theorems about Paley graphs, prime graphs, and crossword puzzles. It will be very fun.

The results in the section about Paley graphs include structure theorems about the subgraph induced by the quadratic residues, the subgraph induced by the non-residues and a few related subgraphs. The main is to better understand the “independence structure” of the Paley graph itself. No good upper bound on the independence number of Paley graphs is known. Theorems about these subgraphs, and various counts aim at future improvement of upper bounds for …

Acute Effects Of An Oral Nicotine Pouch In People Who Use Smokeless Tobacco, Alisha Eversole

Theses and Dissertations

People who use smokeless tobacco (SLT) are exposed to a variety of carcinogenic toxicants, yet, despite health risks, nearly 6 million people in the US use SLT. SLT contains and delivers nicotine, a psychostimulant that causes dependence and hinders cessation efforts. An orally-administered nicotine pouch marketed as “tobacco-free” recently has become available for purchase in the US. However, there are very few non-industry-sponsored studies regarding the effects of these oral nicotine pouches.

The current study used clinical laboratory methods to determine the acute effects of an oral nicotine pouch in people who use SLT. Participants completed four sessions (within subjects, …

Mental Health Help-Seeking Behaviors And Service Utilization Of Black College Students, Troy J. Keys

Theses and Dissertations

Black college students are less likely to seek mental health services compared to other students. While previous research has identified barriers and facilitators contributing to Black college students’ help-seeking behaviors, the current political and social climate and pandemic have negatively impacted their mental health thus warranting the exploration of these factors again. This study aimed to identify the mental health help-seeking behaviors and attitudes of Black college students, the barriers and supports for help-seeking behaviors, their preferred service utilization providers, and their thoughts about promoting mental health help-seeking among their peers. Black college students (n = 21) enrolled at an …

Assessing Providers’ Readiness To Integrate Mat Services In A Primary Care Setting, Carmen Ingram-Thorpe

Theses and Dissertations

Opioid use disorder is a growing concern in the United States. Despite medication-assisted treatment (MAT) being a more effective treatment option than behavioral treatment alone, primary care providers’ rate of adoption and utilization of MAT has not matched the demand of the opioid crisis. The largest barrier facing our local community is the availability of organizations and providers that can and will actually provide MAT services. The purpose of this study was to identify factors that impact primary care providers’ readiness to treat individuals with opioid use disorder (OUD) using MAT. This study used the ADKAR model as framework, which …

Towards Effective Developer Communication In Open Source Software Via Emotional Awareness, Mia Mohammad Imran

Theses and Dissertations

Emotions play an integral yet understudied role in open-source software development, profoundly shaping critical collaborative processes such as knowledge sharing, decision-making, and team dynamics. However, accurately detecting and analyzing emotions in developer communications poses significant challenges due to the lack of visual and auditory cues in text-based interactions. This dissertation investigates techniques to enhance the understanding and modeling of emotions within the textual artifacts of open-source projects. We conduct an extensive evaluation of existing emotion classification tools using a novel dataset of annotated GitHub comments. An error analysis reveals deficiencies in handling implicit emotional expressions and figurative language. We demonstrate …

Mindfulness, Moral Outrage, And The Climate Crisis: A Novel Approach Toward Motivating Pro-Environmental Behaviors, Erika Blair

Theses and Dissertations

The consequences of anthropogenic climate change are severe, continuously accelerating, and pose serious threats to the human and natural world. It is imperative to address the climate crisis from a psychosocial perspective and incite lasting, individual-level behavioral change. Various theoretical models have been adapted or developed to explain pro-environmental behaviors. However, the predictive powers of the most commonly used models have proven to be limited, and the underlying psychological processes of pro-environmental behavior constitute a significant gap in the literature. The present study identifies two psychological processes that show significant promise in motivating pro-environmental behaviors: moral outrage and mindfulness. Moral …

Investigating The Impact Of Chronic Inflammatory Pain On Ethanol Consumption In Mouse Models., Joshua L. Hunt

Theses and Dissertations

Chronic pain affects nearly 20% of Americans annually and for many alcohol provides a convenient and legally acquired palliative. Population-based studies have suggested a link between increased alcohol use and reduced pain, but chronic or excessive alcohol use potentiates the risk to develop alcohol dependence and neuropathy. However, sex differences in chronic pain and alcohol abuse are still not well understood. In the present study, we investigated whether chronic inflammatory pain using the inflammatory agent Complete Freund’s Adjuvant (CFA) model could alter ethanol consumption in male and female C57BL/6J mice. We observed that only CFA-treated male mice increased their ethanol …

Problems In Graph Theory With Applications To Topology And Modeling Rna, Rayan K. Ibrahim

Theses and Dissertations

In this thesis, we explore four projects. In the first project, we explore $r$-neighbor bootstrap percolation on a graph $G$. We establish upper bounds for the number of vertices required to percolate in the case that $r=2$ for particular classes of graphs. In the second project, we study the structure of graphs with independence number two. We prove a lower bound on the number of edges of such graphs, related to an upper bound on the number of edges in a triangle-saturated graph, and give a sufficient forbidden induced subgraph condition for independence number two graphs. In the third project, …

Memory Impairments Due To Binge Ethanol Are Impacted By Age And Sex, Maria Alexis M. Bent

Theses and Dissertations

Ethanol is the most consumed drug among adolescents, which can cause long-term effects on memory and changes in gene and protein expression. While both adolescents and adults engage in binge drinking, the neurological and behavioral effects differ, with adolescents showing fewer adverse physiological effects but greater memory deficits than adults. Sex differences related to ethanol occur with women showing higher BEC than men and similar cognitive deficits despite fewer years of ethanol consumption. During adolescence the mPFC and dHPC undergo maturation development with both brain regions playing a role in spatial and recognition memory. Proteins critically involved in memory and …

Exploring The Role Of Senescence In Disuse-Induced Bone Loss And Therapeutic Strategies For Prevention, Steven J. Meas

Theses and Dissertations

Both age-related and disuse-related bone loss result in decreases in bone mineral density, cortical thickness, and trabecular thickness and connectivity. Disuse induces physiological changes in bone similar to those seen with aging. This study compared age- and disuse-related bone loss using C57BL/6J mice of various ages that were hind-limb unloaded (HLU). In male and female mice, HLU induced a bone phenotype between those of 6-month-old and 22-month-old control mice. Gene analysis suggested that HLU leads to mitochondrial dysfunction, while aging primarily downregulates cell cycle processes. Although, the specific response to HLU appeared to be dependent on age. The study identified …

Leaf To Canopy Functional Resilience: Plant Physiological And Carbon Cycling Stability Following Disturbances, Lisa T. Haber

Theses and Dissertations

Ecological disturbances impact core ecosystem functions, including production and biogeochemical cycling, by precipitating changes in biodiversity, physical environmental variables, vegetation structure, and functional trait distributions. As disturbance patterns intensify and abruptly transition to novel regimes under global change, future trajectories of ecosystem functions, including carbon (C) uptake and storage, are uncertain. A more complete understanding of the mechanisms underpinning ecosystem stability (or ability to return to baseline functioning) following disturbance is needed to forecast future C cycling.

Replicated ecosystem-scale disturbance experiments, particularly when coupled with modeling, are required to rigorously test hypothesized trajectories of ecosystem structural and functional change following …

A Qualitative Analysis Of Section 1983 Filings By Incarcerated Plaintiffs, Hollie Macdonald

Theses and Dissertations

The onset of the COVID-19 pandemic was a “watershed moment" in human history, transcending its role as a mere health crisis to reveal deeper fissures within societies. The present retrospective longitudinal study examined COVID-19 as an “era” of complexity utilizing it as an intermediate construct that delineates “pre-COVID” and “post-COVID.” In order to understand the impact of the COVID-19 era, the design of the study and hypotheses stem from an assumption of the interconnectedness of issues related to health, social justice, racial justice, politics, and information dissemination.

This study utilized both manifest and latent content analysis to explore the most …

The Relationship Between Outcomes Associated With Patient Blood Management Programs And Transfusion Safety Officers, Gary Morral

Theses and Dissertations

BACKGROUND: Patient Blood Management (PBM) has become the standard of care for transfusion services in hospitals. Transfusion Safety Officers (TSOs) have been identified by some as being a crucial part of a successful PBM program; however, no studies have been done to show their effectiveness, or if there is even a relationship between having a TSO and outcomes associated with PBM programs. The purpose of this study was to describe and test the relationship between having a TSO and six outcomes associated with PBM programs including blood product wastage (red blood cells, plasma, and platelets), hospital lengths of stay, rates …

Effect Of Social Anxiety On Trial-By-Trial Changes In Attentional Biases To Emotional Faces, Nina Plotnikov

Theses and Dissertations

Cognitive research suggests that many anxiety disorders, including social anxiety disorder, are associated with an increased attentional bias toward potentially threat-related stimuli. However, inconsistent findings suggest the effect of anxiety on attentional bias to threat is not direct and that other factors, including emotion, perceptual load, and time on-task, impact the relationship between social anxiety and attentional biases to facial stimuli. In the present study, 157 undergraduate students completed a computerized letter search task identifying one of two target letters (N or X) from a circular arrangement of different letters (high load) or dots (low load). In 20% of trials, …

Modeling The Radiation Shielding Effectiveness Of Hafnium Diboride Reinforced Epoxy Composites Using Mcnp, Randolph Snook

Theses and Dissertations

This thesis uses MCNP simulations to evaluate the performance of a radiation shielding material consisting of Hafnium Diboride (HfB₂) powder in an epoxy matrix. Comparing the results to previously measured data against both gamma and neutron sources, suitability for other applications can be confirmed. The model simulated the epoxy material with different weight percentages of HfB₂ and thicknesses. It was compared to other shielding materials such as pure epoxy and 5% Borated High Density Polyethylene (HDPE-B). The HfB₂-epoxy composite was tested against a wide energy range gamma spectrum from a ¹⁵²Eu source, and neutrons …

Who Is Responsible For Corporate Social Responsibility? Investigating Employees’ Roles As Agents Of Csr, Leah Alley

Theses and Dissertations

Corporate social responsibility (CSR) can be thought of as involving an interaction between two parties: one party who performs the socially good deed (i.e., the “agents” of CSR), and another party who is to receive its benefits (i.e., the “intended beneficiary” of CSR). Research on employee reactions to CSR largely focuses on employees’ reactions to CSR in general, which makes it impossible to assess how employees’ roles as agents and beneficiaries of CSR influence subsequent attitudes and behaviors. Theories of justice suggest that employee perceptions of CSR change when they are and are not the agents and beneficiaries of CSR, …

Exploring End-User Environments For The Control And Programming Of Collaborative Robots, Luiz Felipe Fronchetti Dias

Theses and Dissertations

To collaborate with the ongoing development of robotics, this thesis highlights three research contributions to collaborative robot programming. The first study evaluates block-based programming as an alternative for two-armed robots. A commercial solution is put in contrast with a block-based programming language. Both programming solutions are evaluated by 52 participants in an experiment involving a pick-and-place task. This study brings insights into human-robot collaboration, including robot positioning and interaction challenges. The second study discusses using mixed-reality devices as a potential workaround to the manual positioning of industrial and collaborative robots. Five different control interfaces implemented in mixed reality were used …

Special Educators’ Insights On Essential Mentoring Components: A Mixed-Method Examination, Rachel W. Bowman

Theses and Dissertations

This mixed-method study used the Nominal Group Technique to gain insights into the essential components of mentoring programs for new special education teachers. Mentors and mentees participated in highly-structured focus groups in which they generated, discussed, ranked, and rated ideas about important elements of mentoring and considerations for matching mentors and mentees. Transcriptions of interviews were coded and analyzed to generate themes, and means of rankings and ratings were calculated. Qualitative and quantitative data were compared, and data were disaggregated by the racial background of the participants. Findings indicated that mentoring programs and matches must be thoroughly individualized and focus …

Enhancing Chemotherapeutic Efficacy Of Doxorubicin Through Combination Therapy With Rapamycin And Sildenafil, While Providing Cardioprotection In Breast Cancer Models, Rebecca Mathew

Theses and Dissertations

Doxorubicin (DOX) is a common chemo-drug for breast cancer, but it causes severe cardiotoxicity. This study explores combining Sildenafil (Sild) and Rapamycin (Rapa), which inhibit phosphodiesterase-5 (PDE5) and mTOR, respectively, to boost DOX’s anticancer, but provide cardioprotection. Triple negative human (MDA-MB-231) and murine (4T1) breast cancer cells were treated with DOX (1 µM) with/without Rapa (100 nM) and Sild (10 µM) for 24-72 hours to analyze cell death, cell viability assays and protein expression. Human epidermal growth factor receptor 2-positive breast cancer (SKBr3) spheroids were treated with the same concentrations of DOX and/or AG825 (5µM) with/without Rapa and/or Sild for …

Mathematical Analysis Of Eukaryotic Pericentromere, Puranjan Ghimire

Theses and Dissertations

The centromere is crucial for chromosomal stability and their proper segregation during cell division in eukaryotes. Surrounding the centromere are pericentromeres, made of repetitive DNA elements called pericentromeric repeats, varying from 10 in fission yeast to thousands in humans. These repeats form densely packed heterochromatin, where genes are usually silenced. The silencing mechanism across different pericentromeric repeats remains unclear.

Despite variations in sequence and length, pericentromeric repeats are conserved across eukaryotes, indicating their functional importance. This dissertation presents mathematical models to quantify gene silencing in fission yeast and humans. In fission yeast, my model predicts that silencing occurs only with …

The Regulation Of Laryngeal Cancer Cell Phenotype And Proliferation By 24r,25-Dihydroxyvitamin D3 Is Correlated With Erα Isoform Expression, Cydney Dennis

Theses and Dissertations

Laryngeal cancer is the most common type of head and neck cancer and is associated with poor prognosis due to common delayed diagnoses. The sex disparities associated with laryngeal cancer are constantly growing, as the risk of malignancy in males is continually increasing compared to women. Due to the high chance of late-stage diagnosis requiring aggressive treatments, there is a high demand for less aggressive treatment options and early-stage diagnostic markers. The apparent sex disposition of the larynx, the correlation between sex hormones, and the risk of malignancy in aging men suggest that estrogen may play a role in laryngeal …

Exploring Emerging Adults' Consideration Of Future Cancer Risk Reduction: Opportunity For Shifting Prevention Paradigms?, Jacqueline Knight Wilt

Theses and Dissertations

Background
Early onset colorectal cancer (EOCRC) among individuals younger than age-based population prevention screening guidelines has been linked to lifestyle-related risk factors. Emerging adulthood (18-25 years) is when elevated autonomy can alter health behaviors with implications for future health. Greater consideration of future consequences for behavior predicts several lifestyle health behaviors. Future consideration is sensitive to resource availability, and thus may differ between students who are first-generation and/or from low-income households (FGLI) compared to Non-FGLI. This dissertation study aimed to (1) characterize college students’ consideration of future cancer risk (CFC-Cancer), perceived colorectal cancer (CRC) risk and associations with EOCRC risk …

Explore Security And Machine Learning Applications In Next Generation Wireless Networks, Haolin Tang

Theses and Dissertations

Next-generation (NextG) or Beyond-Fifth-Generation (B5G) wireless networks have become a prominent focus in academic and industry circles. This is driven by the increasing demand for cutting-edge applications such as mobile health, self-driving cars, the metaverse, digital twins, virtual reality, and more. These diverse applications typically require high communication network performance, including spectrum utilization, data speed, and latency. New technologies are emerging to meet the communication requirements of various applications. Intelligent Reflecting Surface (IRS) and Artificial Intelligence (AI) are two representatives that have been demonstrated as promising and powerful technologies in NextG communications. While new technologies significantly enhance communication performance, they …

Behavioral Effects Of Adolescent Social Isolation Stress And/Or Binge Drinking And The Role Of The Vhip --> Mpfc Circuit, Jyoti Lodha

Theses and Dissertations

Adolescence is characterized by heightened social interaction and risk-taking behavior. Disruptions to cortical development by binge ethanol or social isolation can lead to attention, social, and cognitive deficits later in life, and increase risk for alcohol use disorders. During adolescence, proper development of a monosynaptic connection from the ventral hippocampus (vHip) to the medial prefrontal cortex (mPFC) is critical to proper social and working memory. We ask whether these factors affect neurobiological factors such as gene expression and the role of the vHipmPFC circuit in these behaviors. Social stress was modeled by social isolation (aSI) during adolescence. We expect aSI …

The Role Of Mirna-17-92 Following Myocardial Ischemia/ Reperfusion Under Normal And Diabetic Conditions, Virginia Villani Zwiren

Theses and Dissertations

Background: Cardiovascular disease (CVD) is the leading cause of death worldwide. The risk of developing CVD is increased two-to-four-fold in patients with diabetes, and, following a myocardial infarction, patients with diabetes often have worse outcomes. Dysregulation of individual or clusters of microRNAs is linked to the pathogenesis of heart diseases and its risk factors, such as diabetes, hypertension, atherosclerosis, myocardial ischemia/reperfusion (I/R) injury, and heart failure. Our study identified that the microRNA-17-92 cluster (miR-17-92) is suppressed in diabetic hearts with CVD. The purpose of the present study is to define how miR-17-92 attenuates injurious signaling in the post ischemic heart …

Exploring Serotonin 1b Autoreceptor Mediated Regulation Of Serotonin Transporter In Female Mice, Sanyukta Jalihalkar

Theses and Dissertations

Rationale: Serotonin (5-HT) is a crucial neurotransmitter involved in regulating various physiological processes. Dysregulation of the serotonergic system has been implicated in several neuropsychiatric disorders. Though numerous 5-HT receptors exist, the 5-HT transporter (SERT) is responsible for 5-HT clearance in the brain and periphery. 5-HT_1Bautoreceptors regulate 5-HT release and interact with glycogen synthase kinase-3β (GSK3β), which can modulate SERT function via specific Ser44/48 phosphorylation sites. While these findings suggest a potential interplay between 5-HT_1Band GSK3β-mediated SERT phosphorylation in regulating extracellular 5-HT, the primary causal molecular link remains unknown.

Objectives: To investigate if 5-HT_1B activation by …

Energy Efficient Spintronic Devices For Non-Volatile Memory And Hardware Ai, Walid Al Misba

Theses and Dissertations

Nanomagnetic devices have emerged as a promising alternative to conventional complementary metal-oxide-semiconductor (CMOS) devices due to their low energy dissipation and inherent non-volatility. However, the widespread adoption of these devices requires high-density, high-speed, reliable, scalable, and energy-efficient technologies. This thesis investigates the use of nanomagnetic memory devices as both conventional Boolean memory and multistate memory for hardware AI applications.

Magnetic tunnel junctions (MTJs) are nanomagnetic memory devices that can be switched reliably and energy-efficiently using stress-mediated switching. However, realistic material inhomogeneity and scalability pose challenges for stress-mediated switching of MTJs scaled to lateral dimensions below 50 nm. We demonstrate that …

A Complexity Aware Overlay Architecture For High Integrity Fpga Based Systems, Richard Dwight Hite Jr

Theses and Dissertations

Cyber-Physical systems are becoming more and more prevalent in our society and are simultaneously becoming more complex due to evolving technological capabilities in both hardware and software. This complexity exacerbates verification and validation activities thereby negatively impacting important system attributes like design assurance, system reliability, development costs and trust. These facts necessitate the need for computing architectures that constrain complexity for the sake of assurance. Traditional software and hardware development for safety-critical systems have been demonstrated in previous safety-critical systems and the established development methodologies are well understood. However, both technologies have their strengths and limitations. Processor-based technology (SW based …

Transforming Children's Oral Health: The Impact Of Oral Healthcare Policies On Virginia Medicaid Dental Health Outcomes., Anita M. Kumar

Theses and Dissertations

Abstract: Transforming Children's Oral Health: The Impact of Oral Healthcare Policies on Virginia Medicaid Dental Health Outcomes.

Objectives: This dissertation uses Department of Medical Assistance Services (DMAS) administrative files at the individual and provider level from fiscal years (FY) 2011 to 2021 to systematically study the effect of recently implemented oral health policies (EBD guidelines on sealants, CMS updated quality measures, expansion of Medicaid oral healthcare for qualifying pregnant women) on oral health outcomes of Virginia Medicaid-enrolled children.

Methods: The studies employ a difference in differences regression methods (negative binomial, Poisson, and logistic) to examine the effects of oral health …

Exploration Of Dopaminergic And Serotonergic Pathways Utilizing Pleiotropic Agents, Charles B. Jones Iii

Theses and Dissertations

2-(Benzoyl)piperidines (BPs) are at a crossroads of therapy and abuse. These compounds are a hybrid between the ADHD medication methylphenidate and abused stimulant cathinones. Here we use computational molecular modeling, synthesis, mutagenesis, and epifluorescence microscopy to further improve the understanding of and potential treatments for several neuropsychiatric disorders. Utilizing the BP scaffold and controlling chirality and aryl substitution, these agents were examined at DAT and SERT. From these investigations it has now been established that R isomer BPs are favored for DAT while S isomer BPs are favored for SERT. Aryl-substitution can greatly affect the selectivity of these agents with …