Digital Commons Network^™

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 …

An Examination Of The Determinants Of Audit Quality: Implications From Firms Listed In Us Stock Markets, Abdelrahman Naser Elmaria

Theses and Dissertations

The purpose of this thesis is to examine the effect of several audit determinants, namely audit tenure, non-audit to audit fees ratio, auditing firm size, and firm size, impact on audit quality. This thesis extends the existing literature on audit determinants effect on audit quality using a Generalized Linear Model, (GLM) regression with robust estimation by analyzing a sample of 446 companies from the USA in the manufacture and service sectors. This is conducted through a series of diagnostic tests to identify an appropriate regression model. Such tests include testing and checking of baseline regression models to check for multicollinearity, …

Trajectories Of Egyptian Women In The Us, Sageda A. Tagen

Theses and Dissertations

This thesis aimed at studying and analyzing the experiences of highly skilled Egyptian migrant women living in the US both who migrated as adults and those who migrated as children with their families. It analyzed their backgrounds prior to the migration decision, the migration decision and their legal status, the role of the family in their journey and their challenges within the social context of their workplaces. The study utilized a qualitative ethnographic lens. The study is based on ethnographic interviews with 15 highly skilled women living in the US, most of whom are concentrated in Indiana and Michigan. The …

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 …

Psychometric Evaluation Of The Treatment Integrity Instrument For Elementary School Classrooms - Observer Report: Preliminary Evidence For Construct And Discriminative Validity, Cristian J. Rivera Nales

Theses and Dissertations

Treatment integrity is the degree to which a program and its practices are delivered as intended. Treatment integrity measures are critical for evaluating the effectiveness of evidence-based programs (EBPs) in effectiveness research, but few are designed for research conducted in community settings, such as schools. The Treatment Integrity Instrument for Elementary School Classrooms – Observer Report (TIES-O) is an observational measure used to assess the treatment integrity of teachers implementing EBPs in their classrooms. This study evaluated the psychometric properties of the TIES-O, which captures Adherence (frequency and thoroughness of delivery) Competence (skillfulness of delivery), and Differentiation (the extent to …

Staging Violence With Intentionality, Toby O'Brien

Theses and Dissertations

This thesis examines the role of the fight choreographer in the theatre while addressing the potential issues staged violence has in distracting an audience from the intended narrative of the play. Avoiding the instruction manual approach of stage combat in favor of expounding on the theory of violent entertainment, I have constructed a thesis that informs the reader of certain types of violence found in both classical and modern productions and have researched the psychological ramifications of violent spectatorship and the necessity for content acknowledgements as well as consideration for the performer’s well-being. By exploring the history of violent entertainment …

Your Left Or Mine: A Journey To Accessibility For Learning Disabilities And Neurodivergence In Stage Combat Pedagogy, Ambria Campbell

Theses and Dissertations

This thesis examines stage combat pedagogy from its inception to the present day through the lens of accessibility for learning disabilities and neurodivergence. Relevant research in education as it relates to disability is analyzed and applied to the field of stage combat pedagogy. What follows is a deconstruction and reconstruction of beginning level stage combat pedagogy to increase accessibility. These ideas are then tested and the results reflected on. This thesis focuses on college level and aged students who are the most likely demographic for beginning stage combat students. The completion of this thesis does not represent an endpoint in …

Medical Linear Accelerator Water Tank Measurements Optimization For Commissioning, Tyler R. Laugh

Theses and Dissertations

Beam commissioning is a critical component of linear accelerator (LINAC) implementation, requiring accurate measurement of percent depth dose (PDD), beam profiles, and output factors across a wide range of field sizes. Conventional commissioning workflows often require multiple detectors and can be time-intensive, particularly for small-field dosimetry where measurement accuracy is highly sensitive to detector characteristics. This study evaluated the performance of a plastic scintillation detector (BP-PSD) for full water tank commissioning and its potential to improve efficiency while maintaining dosimetric accuracy.

Beam data were acquired for field sizes ranging from 1 × 1 cm² to 40 × 40 cm² using …

Regulation Of Tgf-Β1–Induced Epithelial–Mesenchymal Transition By Integrin Inhibition, Wesam Elhawabri

Theses and Dissertations

Epithelial–mesenchymal transition (EMT) is a critical process underlying cancer progression, fibrosis, and tissue remodeling, characterized by coordinated changes in cell morphology, nuclear structure, and extracellular matrix (ECM) organization. Transforming growth factor beta 1 (TGF-β1) is a primary inducer of EMT; however, the extent to which integrin-mediated signaling and ECM remodeling regulate these structural changes remains incompletely understood. In this study, we quantitatively investigated EMT-associated remodeling in A549 lung carcinoma cells and MCF10A epithelial cells following TGF-β1 stimulation. Cells were cultured on ECM-coated substrates and treated with TGF-β1 in the presence or absence of integrin-targeting inhibitors (ATN-161, 28-G11, and STX-100). Im …

Spilt Milk, Fatima Kaleem

Theses and Dissertations

Spilt Milk explores how institutional discipline is rehearsed across the Pakistani home, school, and television soap opera. These seemingly domestic spaces converge at the military-industrial complex, where media propaganda (ISPR) and consumer commodities collaborate to manufacture a unified national identity.

Through an installation of school desks and re-fabricated cereal boxes, this project examines the ‘cereal/serial’ as a site of ideological consumption. By refabricating these boxes with embroidery, drawing, lace, and synthetic hair, the work subverts state-mandated narratives. These material interventions replace assembly lines with spills of hair and sweat to highlight the vulnerability of the body under surveillance. This project …

Timing And Stability Of Uav Operations In Smart City Environments: Experimental Analysis And Design Implications, Rabia Ipek Yasar

Theses and Dissertations

This thesis investigates the deployment and performance of unmanned aerial vehicles (UAVs) within the Virginia Commonwealth University Open Cyber City (OCC) testbed. The study focuses on evaluating real-time indoor positioning performance using the Crazyflie drone platform. High-precision position measurements are obtained using the Vicon motion capture system, enabling analysis of the latency between the drone’s actual position and the system-reported position. In a closed-loop control system, the time difference between the position measurement and the application of the control command is called the system delay. Both stationary (hovering) and trajectory-following experiments are conducted to evaluate system performance. Communication delays in …

Examining Mental Healthcare Underutilization Among Latino Immigrants: Healthcare Providers’ And Community Health Workers' Perspectives, Geovani Muñoz

Theses and Dissertations

Latinos continue to experience many logistical and systemic barriers to professional mental health services (Derr, 2016) despite being the second-largest racial-ethnic group in the United States (U.S.). With a community of 65 million people (U.S. Census Bureau, 2024), Latinos experience mental healthcare inequalities (Cook et al., 2019) due to structural, cultural, and systemic barriers. Although prior research has emphasized culturally responsive care as a pathway to reducing disparities (Nagy et al., 2025), much of the literature has focused on Western medical models, with limited attention to community-based perspective. Guided by the Knowledge, Attitude, and Practices (KAP) framework, the present study …

Plumbed 3-Manifolds And Neumann Moves, Noah J. Pope

Theses and Dissertations

We give a constructive proof that every weakly negative definite plumbing tree can be transformed into a negative definite one by a finite sequence of Neumann moves. The argument combines Neumann’s plumbing calculus with the diagonalization algorithm of Duchon, Eisenbud, and Neumann, which extracts the eigenvalues of the framing matrix directly from the combinatorics of the tree. We show that any positive eigenvalues are supported on linear branches and can be eliminated systematically via controlled applications of Neumann moves. This provides an explicit algorithm reducing weakly negative definite plumbing trees to negative definite ones.

Dietary Acculturation, Dietary Inflammatory Potential, And Metabolic Syndrome Among Immigrants In The United States: A Mixed-Methods Approach Using Nhanes And Qualitative Data, Esse G. Foka Nzaha

Theses and Dissertations

Background and Objectives: Immigrants in the United States undergo acculturation — a process of sociocultural and behavioral adaptation to the host country. Increasingly, behavioral adaptations have been associated with cardiometabolic health and chronic disease risk. Metabolic syndrome (MetS), a cluster of conditions including abdominal obesity, elevated blood pressure, impaired fasting glucose, elevated triglycerides, and reduced HDL cholesterol, is a major risk factor for type 2 diabetes mellitus, cardiovascular diseases and other chronic diseases, including cancer. Despite the growing immigrant population in the U.S., the role of diet and dietary acculturation in MetS development remains poorly understood in this population. This …

Mediator: Ornament As A Visual Language Of The Transcendent, Selma Fejzullaj

Theses and Dissertations

Adolf Loos’s declaration that “ornament is a crime” defined modernist design, establishing a legacy that dismisses ornamentation as wasteful and regressive. This research questions that legacy by repositioning aesthetics as a divinely grounded value, inspired by the Qur’anic vision of Paradise. In this celestial realm, beauty is not wasteful but a manifestation of divine perfection. Conceptually, the project reclaims ornament as a vital tool for contemplating metaphysical themes. Materially, it reimagines glass, shifting it from modernist "radical honesty" to a medium of layered depth. Recombining traditional Islamic ornamentation practices such as Girih and Chaharbagh, the project evokes the Qur’anic vision …

A Mathematical Frameworks For Singular, Nonlinear Phenomena: Applications To Nematocyst Firing And Inhomogeneous Nls With Coulomb Potential, Abdulrahman Alharbi

Theses and Dissertations

Nematocysts are specialized cellular organelles found in all cnidarians, including corals and jellyfish, as well as in some single-celled protists such as dinoflagellates. These organelles display remarkable diversity in morphology and function, playing roles in prey capture and defense. The firing of a nematocyst is one of the fastest accelerations in nature, yet the underlying physical mechanisms remain not fully understood. In this work, we address key questions: how sufficient force is generated to overcome the fluid boundary layer, whether fluid–structure interaction models can reproduce observed dynamics, and what mechanisms trigger discharge.

Our research investigates models based on osmotic pressure …

Synthesis Of Iso-Dityrosine, A Potential Biomarker Of Neurodegenerative Diseases, Brandon R. Knouse

Theses and Dissertations

As the population of the United States continues to age, the prevalence of neurodegenerative disorders is rising, increasing the societal and clinical burden of diseases such as Parkinson’s disease and dementia-related conditions. Lewy Body Dementia (LBD), the second most common cause of dementia, shares underlying neuropathological features with Parkinson’s disease, including the aggregation of misfolded α-synuclein into Lewy bodies and Lewy neurites. Current diagnostic approaches rely heavily on cerebrospinal fluid biomarker analysis; however, significant overlap exists among biomarkers associated with Alzheimer’s disease and other neurodegenerative conditions, limiting diagnostic specificity. Emerging evidence suggests that oxidative modifications of α-synuclein, particularly the formation …

What’S Sleep Got To Do With It? A Mixed Methods Exploration Of The Feasibility, Acceptability, And Initial Outcomes Of Group Cbt For Insomnia In Parkinson’S Disease, Claire M. Williams

Theses and Dissertations

Parkinson’s disease is a progressive neurodegenerative disease that is commonly associated with sleep disturbances, affecting up to 80 percent of individuals with Parkinson’s. Effective and accessible treatments for sleep problems in Parkinson’s disease remain limited. Cognitive Behavioral Therapy for Insomnia (CBTi) is a well-established, non-pharmacological treatment for insomnia but has been minimally studied in Parkinson’s populations. This study evaluated the feasibility, acceptability, and preliminary outcomes of a group-based CBTi intervention adapted for individuals with Parkinson’s disease. Participants engaged in a six-week group intervention that incorporated Parkinson’s-specific adaptations. Preliminary findings indicated that the adapted group CBTi intervention was generally feasible and …

Comparison Of Artificial Intelligence Vs Human Observer For Periapical Radiolucency Detection, Adam J. Pink

Theses and Dissertations

Objective: The aim of this study was to assess the performance of an Artificial Intelligence (AI) program (OverJet AI) with that of experienced endodontic residents, endodontists, a radiologist, and dental students in detecting periapical radiolucencies using radiographic images.

Methods: One hundred and fifty periapical radiographic images were analyzed using the OverJet AI software to determine the presence/absence of a periapical radiolucency as well as the size (small 1-3mm, medium 4-6mm, and large 6+mm). The unaltered images were also evaluated by two endodontic residents, two practicing endodontists, an oral radiologist and two 4th year dental students.

Results: Agreement between the AI …

Class-Aware Early-Exit Networks For Efficient And Secure Edge Deployment, Mohammed Ayyat

Theses and Dissertations

Edge devices increasingly run high-stakes machine learning workloads under strict latency, power, memory, and communication constraints. Deep neural networks provide the accuracy needed for tasks such as network intrusion detection, health monitoring, autonomous sensing, and human activity recognition, but conventional inference executes the same computational path for every input. Early-exit neural networks reduce average inference cost by allowing confident samples to terminate before the final layer. However, existing early-exit systems are largely class-agnostic: they allocate computation according to confidence or uncertainty, without considering that different output classes may carry different operational urgency. This dissertation develops class-aware early-exit inference, a framework …

Partisan Local Media And Corporate Voluntary Disclosures: Evidence From Sinclair Acquisitions, Ming Li

Theses and Dissertations

I investigate the impact of local media’s political orientation on firms’ voluntary disclosure, exploiting the acquisitions of local TV stations by Sinclair Broadcast Group, a conservative media conglomerate. Drawing on the media bias theory and implementing a staggered difference‐in‐differences design, I find that the local partisan media affects management earnings forecasts. Specifically, Conservative-leaning CEOs in designated market areas (DMAs) affected by Sinclair’s acquisitions forecast more optimistically, increasing forecast frequency and inflating forecasted earnings. The impact is stronger if the DMAs are more Liberal-leaning before the acquisitions and when firms have weaker corporate governance. I also find that the stock market …

Discrete Cell Signaling Differences Cause Female-Dominant Il-33 Responses In Mast Cells, Tania D. Maldonado

Theses and Dissertations

Many allergic diseases are more common and severe in women than in men. A key component of allergic inflammation is IL-33, a cytokine released by epithelial cells after allergen exposure. Because mast cells are a central early responder in allergic disease and are activated by IL-33, we investigated sex differences in mast cell responses to IL-33. We first found that male mast cells expanded poorly in standard RPMI-based culture media containing phenol red, which has estrogenic properties. Male cells also responded poorly to IL-33 when cultured with in media containing phenol red. In contrast, female mast cells expanded 3-fold less …

Climate, Biogeography, And Dispersal: A Unifying Framework For Ameri-Caribbean Dry Forests, Pablo Lopez Bustamante

Theses and Dissertations

Seed dispersal is a crucial ecological function that enables plants to alter their distributional range, avoid intense competition and natural enemies near the parent plant, and recover from disturbances. These processes shape species and functional composition of forests. Wind has traditionally been considered the dominant dispersal mechanism in Ameri-Caribbean dry forests, yet growing evidence suggests that other dispersal mechanisms also play significant roles in this ecosystem, responding differently to biotic and abiotic conditions. Still, how dispersal syndrome composition influences plant communities, the ecological drivers underlying these patterns, and the effects of climate change on dispersal syndrome dominance remain poorly understood. …

Managing Identity, Claiming Expertise, And Emotional Labor: A Constructivist Grounded Theory Of The Experience Of People With Serious Mental Illnesses In Primary Care, Jeffrey Ciak

Theses and Dissertations

People with serious mental illnesses (SMI) die 15 to 20 years before their peers without mental illness primarily due to chronic physical health conditions. Preventative care and treatment for chronic physical health conditions primarily occurs through primary care, but the experience of people with SMI in primary care is understudied. This constructivist grounded theory dissertation explored the experiences of people with SMI in primary care. Theoretical sampling resulted in 19 participants who were adults with SMI and long-term anti-psychotic use. Data was collected through one-to-two-hour long intensive interviews. The analytical process occurred concurrently with data collection. The abductive analytical process …

Sex In Plants: Birth, Death, And Trying To Survive In Changing Climates, Elena M. Meyer

Theses and Dissertations

Plant mating systems are key determinants of fitness. Angiosperms exhibit a wide variety of reproductive strategies, including self-fertilization (or selfing), outcrossing, and mixed mating. It has been estimated that up to 43% of plant species are capable of selfing, and selfing has been hypothesized to provide reproductive assurance where opportunities for mating may be limited, such as in marginal environments. However, questions regarding the overall distribution of selfing rates across angiosperms, the maintenance of mixed mating in the face of inbreeding depression, and the impact of self-fertilization on diversification rates remain incompletely resolved. Here, we explore the dynamics of self-fertilization …

Empirical Dynamical Modeling Of Cortico-Hippocampal Information Transfer During Memory Encoding, Sam Y. Cole

Theses and Dissertations

Understanding how brain dynamics support successful memory formation remains a central challenge in neuroscience. This dissertation applies tools from empirical dynamical systems theory to investigate the neural mechanisms underlying episodic encoding, with a focus on cortico-hippocampal interactions. Using stereoelectroencephalography (sEEG) data recorded during a delayed free recall of word lists task, this work reveals nonlinear, state-dependent shifts in directed information flow between cortex and hippocampus that distinguish successful from unsuccessful encoding. To further characterize these dynamics, state-space trajectories are reconstructed using time-delay embedding and recurrence-based methods, and features derived from these trajectories are used to classify memory outcomes. By integrating …

Real-Life Health Applications Of Wireless Sensing Using Edge Devices, Md Touhiduzzaman

Theses and Dissertations

Wireless sensing has emerged as a transformative paradigm that leverages ubiquitous radio-frequency signals for environmental perception and human activity recognition beyond their primary role in data communication. Unlike wearable sensors and camera-based systems, wireless sensing offers a non-intrusive, privacy-preserving, and cost-effective alternative that operates seamlessly under low-lighting conditions, through walls, and in non-line-of-sight (NLoS) scenarios. The growing availability of edge computing devices further enables real-time on-device data processing, making wireless sensing solutions highly suitable for in-home health monitoring and smart living applications. This dissertation investigates real-life health applications of wireless sensing through four completed systems, each addressing a distinct challenge …

Modeling Of Laser-Produced Plasma Plumes: Expansion, Chemistry, And Thin-Film Deposition, Edmund Tsiri Semaha, Edmund Tsiri Semaha

Theses and Dissertations

Abstract

Laser-assisted material processing involves coupled plasma expansion, chemical reactions, and particle transport that govern the quality of thin-film deposition. This dissertation presents a comprehensive computational investigation of these processes using the OpenFOAM framework. First, the performance of the twoPhaseEulerFoam (tPEF), rhoCentralFoam (rCF), and sonicFoam (sF) solvers is evaluated for modeling laser-produced plasma plume expansion under atmospheric conditions, demonstrating that tPEF accurately captures shock-wave propagation, hydrodynamic behavior, and multispecies interactions. Building on this validation, the reactingFoam (rF) solver is employed to investigate the chemistry of aluminum plasma expanding into an air environment (Al–N₂–O₂). The model incorporates appropriate thermodynamic, transport, and …

Implementation Of Tg-351 Reference Dosimetry For A 6 Mv Photon Beam In An Mr-Guided Radiotherapy System, Nicholas A. Castellano Jr.

Theses and Dissertations

Magnetic resonance guided radiation therapy (MRgRT) combines magnetic resonance imaging (MRI) and radiation therapy to enable the visualization of anatomy in real time during treatment. The presence of a magnetic field in MRgRT affects charged particle radiation and detector responses, necessitating changes to traditional reference dosimetry procedures. The American Association of Physicists in Medicine (AAPM) Task Group 351 (TG-351) provides a formalism for reference dosimetry in MRgRT. In this study, the TG 351 formalism is used to perform reference dosimetry for a 6 MV flattening filter-free (FFF) photon beam from a Viewray MRIdian MR-Linac radiation therapy system. Beam quality determination, …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …