Digital Commons Network^™

An Efficient Implementation Of Gibbs-Duhem Integration For Solid-Liquid Phase Coexistence In Binary Lennard-Jones System With Relevance To Aav Capsid Separation, Muhi Muntaka

Graduate Theses and Dissertations

Gene therapy using adeno-associated viruses (AAVs) holds promise for treating genetic diseases, but high manufacturing costs limit its widespread use. A major challenge is separating functional (full) AAV capsids from non-functional (empty) ones, which are produced in similar amounts and have nearly identical structures. Conventional purification methods, such as density gradient ultracentrifugation and chromatography, face drawbacks like low yield, poor scalability, and high cost, often requiring multi-step processes. Recently, selective crystallization has emerged as a promising alternative, offering improved efficiency, scalability, and product quality. However, optimizing this method requires a deep understanding of thermodynamic phase behavior in multicomponent systems. In …

Unveiling Factors Influencing Extract Yield From Milled Rice In Brewing, Matthew Aitkens

Graduate Theses and Dissertations

Rice (Oryza sativa L.) presents a locally sourced, climate-resistant starch source for the brewing industry. As barley faces increased uncertainty due to rising temperatures, Arkansas-grown rice offers a more stable and cost-effective alternative starch source. However, the use of milled adjunct rice by brewers has remained limited, largely due to knowledge gaps about cultivar-specific properties relative to brewing. Chapter 1 provides an overview of rice as a brewing adjunct, reviewing the physiochemical properties important to brewing success. These properties include kernel size, kernel breakage, amylose content, and gelatinization temperature. Mashing strategies for multiple different brewing layouts are overviewed, showing practical …

From Phenology To Yield Zones: Functional Clustering Of Satellite Time Series For Crop Growth Monitoring, Ikram Morso

Graduate Theses and Dissertations

Remote sensing and land surface phenology provide a strong basis for characterizing crop development, but their usefulness for within-field yield-zone delineation depends on whether crop development is analyzed as a phenological trajectory and whether the resulting zones are evaluated with spatially defensible statistics. These questions are especially relevant in soybean production because soybean is one of the most important row crops in the United States and the country’s dominant oilseed crop. This relevance is strong in Arkansas, where soybean is a major component of agricultural production. In soybean production, within-field yield variability reflects the combined influence of soil properties, stand …

“Menopause Is Universal, But No One Prepared Us”: An Inductive Thematic Analysis Of R/Menopause, Alissa Lauren Hardwick

Graduate Theses and Dissertations

Menopause is a universal biological transition, yet women’s lived experiences of its emotional, cognitive, relational, and healthcare dimensions remain comparatively underrepresented in research. Guided by critical feminist theory and feminist standpoint epistemology, this study examined how women in the r/Menopause online community described experiences of depression and anxiety during the menopausal transition, how they narrated healthcare encounters, and how they made sense of shifting identity and social value. By treating self-authored online narratives as situated forms of knowledge, the study aimed to illuminate how menopausal distress is interpreted and negotiated in everyday discourse. An inductive qualitative reflexive thematic analysis was …

Lumbopelvic Kinematics And Muscular Co-Contractions In Walking Prior To And Immediately Following A Bout Of Prolonged Standing., Stephanie Cotariu

Graduate Theses and Dissertations

Background: Prolonged standing is a common daily activity in a wide array of occupations, and approximately 44% of sample populations develop low back pain (LBP) during prolonged standing. Prolonged standing-induced LBP developers (“Pain Developers”) are three times more likely to develop clinical LBP and can therefore be considered a pre-clinical LBP population. Changes in typical gait have been observed in LBP patients, and walking has been hypothesized as being protective or preventive against LBP development. However, it is unknown whether Pain Developers exhibit similar kinematic adaptations to chronic LBP patients during common daily activities, such as walking. The exact muscular …

Assessment Of The Quality, Practicality, And Economic Viability Of Malted Rice, Bernardo Pontes Guimaraes

Graduate Theses and Dissertations

Climate change threatens the global supply of malting barley, creating a need for sustainable, climate-resilient alternative grains for the brewing industries. This dissertation investigated the chemical, sensorial, practical, and economic viability of using rice as a malting material. First, the malting and brewing qualities of 20 rice samples were evaluated. Results indicated malted rice (MR) had good malting and brewing qualities, including adequate levels of free amino nitrogen (FAN), high amyloglucosidase and limit dextrinase activities. Furthermore, pigmented rice varieties displayed a novel reddish-purple wort color. To identify rice cultivars suited for malting and brewing, the relationship between starch chemistry and …

Religion, Crime, And The Mediating Effects Of Social Control And Self-Control, Parker Bowman

Graduate Theses and Dissertations

Past research on the relationship between religion and crime has found the two variables have a significant negative correlation. Currently, there are two main mechanisms used to explain this relationship: social control and self-control. Social control theorists argue that participation in religious organizations decreases criminal behaviors by increasing social bonds. Self-control theorists argue that religious norms and values decrease criminal behavior by increasing an individual's self-control. While both mechanisms have been well supported by research, there remains the question of which is the stronger mediator of the religion-crime relationship. This study seeks to answer this question by comparing the effects …

Simultaneous Carrier, Cargo, And Functional Tracking Of Lipid Nanoparticles, Hannia Vanessa Balcorta Muñoz

Open Access Theses & Dissertations

Lipid nanoparticles (LNPs) have become effective delivery vehicles in nanomedicine, particularly for nucleic acid-based treatments. However, a major limitation remains in the field regarding the simultaneous monitoring of the nanoparticle carrier, its encapsulated payload, and the resulting functional protein production in both in vitro and in vivo systems. Furthermore, traditional lipophilic dyes employed for labeling LNPs frequently exhibit incompatibility with tissue-clearing methods, such as CLARITY, due to signal loss following lipid removal. This research developed and evaluated a new fluorescent labeling method using CM-DiI, a dye that reacts with thiols, for multimodal tracking of LNPs. CM-DiI was included in the …

Spike-Sorting Algorithm For Neuropixel Probes, Luis David Davila

Open Access Theses & Dissertations

Modern extracellular neural probes like Neuropixels, allow for high-density extracellular neural probes to record terabytes of electrophysiological brain data. Spike sorting is the process of isolating individual neurons on this data through various clustering and filtering techniques. Modern spike sorting algorithms are held back by their need for human intervention to separate high-quality from low quality clusters, due to the volume of data that can be collected a completely automated approach is required. To address this requirement, we have developed a framework to preprocess, cluster, grade, and separate high/low quality clustering results using custom models trained on the grades. To …

The Phylogenetic And Biogeographic History Of Cranes (Gruidae), Phillip Conrad Williams

Dissertations

Cranes (Gruidae) are a globally distributed clade of large, wetland-associated birds. Prior phylogenetic analyses have shown there to be two major subfamilies, Balearicinae and Gruinae, and five consistently recovered clades within Gruinae. However, the relationships among those five clades has remained contentious. In addition, little has been done to reconstruct the biogeographic history of cranes. To that end, I first inferred phylogeny using a large, nuclear dataset sampled from all 15 extant crane species and two outgroup species. The phylogeny mostly agreed with previous analysis using whole mitochondrial genomes but differed in that the Anthropoides species group formed a sister …

Lyapunov-Krasovskii Based Approach To Time-Delay Systems: Computational Efficiency And Feedback Control, Huan Phan

Dissertations

Time-delay systems arise naturally in many engineering applications due to sensing,actuation, communication, and computation delays. The presence of delays has a significant influence on system performance both positively and negatively. Although Lyapunov--Krasovskii functional (LKF) methods provide a systematic framework for stability analysis and controller synthesis, their implementation often suffers from high computational complexity, particularly for large-scale systems and systems involving multiple feedback channels. This dissertation addresses both computational efficiency and feedback control for linear time-delay systems.The first part of this dissertation develops a decomposition-based approach to reduce the computationalburden of stability analysis. By exploiting structured invariant subspaces associated with the …

From Structure To Support: An Integrative Model Of Leadership, Emotional Exhaustion, Role Clarity, And Daoist Moderation, Aradhna Mohan

Dissertations

Rooted in the understanding that effective leadership significantly influences organizational outcomes, this study examines process-oriented relationships between leader initiating structure and subordinate outcomes. Specifically, it extends the leadership literature by focusing on the cognitive resources underlying initiating structure behaviors, such as role-related clarity, that may enhance positive subordinate outcomes and mitigate negative ones. The study also incorporates an underexamined Eastern leadership style, Daoist Water-Like Leadership, and explores its associations with leader initiating structure and consideration. Guided by the Job Demands-Resources (JD-R) model, this research assesses the effects of initiating structure and Daoist leadership on emotional exhaustion, examines the relationship between …

Intelligent Surveillance For Weapon Threat Detection: Transformer-Based Detection And Segmentation Using Thermal And Rgb Imagery, Akhila Kambhatla

Dissertations

Proactive public-safety surveillance requires deep learning systems that can detect and segment weapons reliably under real-world conditions. This research develops and evaluates a progressive, multi-phase pipeline that moves (i) from RGB object detection to pixel-level semantic segmentation and (ii) from visible-spectrum cameras to thermal imagery to improve robustness under low-light, clutter, and occlusion. Early phases establish strong detection baselines using one-stage and two-stage detectors (YOLOv5 and Faster R-CNN) for multi-class weapon localization, followed by practical optimization through pruning and ensembling to reduce false positives and computational overhead while maintaining real-time feasibility. Building on the limitations of bounding-box localization, the methodology …

Robots And Ageing Population – Rehabilitation And Social Robots, Yuzhou Qian, Keng Siau

Research Collection School Of Computing and Information Systems

Population ageing is placing increasing pressure on healthcare and caregiving worldwide. Governments in different countries are looking into the use of advanced information technologies such as artificial intelligence and robotics to help in caring for ageing population. Older adults often need both physical assistance and psychological support, and robots have emerged as a promising technological approach to supplement eldercare. This paper provides an overview of the current state of robots in eldercare. It reviews the major definitions, categories, and features of robots used in healthcare and eldercare. The paper also examines the potential benefits of robotic technologies, such as reducing …

Diacylglycerol Kinase Eta As A Novel Target In Nras Mutant Melanoma, Haley P. Wilson, Casey D. Stefanski, Signe Caksa, Glenn L. Mersky, Scott D. Varney, Jelan I. Haj, Dan A. Erkes, Timothy J. Purwin, Vivian Chua, Andrew E. Aplin

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

NRAS mutations occur in 10%-30% of cutaneous melanomas and are associated with high tumor mutational burden. Mutant NRAS signaling drives aberrant cell growth and proliferation, in part, through activation of the RAF-MEK-ERK1/2 kinase pathway; however, targeted therapies to this pathway have limited effectiveness in patients with NRAS mutant melanoma. The role of other targetable signaling pathways in NRAS mutant melanoma is poorly characterized. Here, we demonstrated that one isoform of diacylglycerol kinase, diacylglycerol kinase eta (DGKη), a lipid signaling regulator, was highly expressed in NRAS mutant melanoma patient samples. Knockdown of DGKH in NRAS mutant melanoma cell lines resulted in …

Twenty-Four-Hour Intermittent Fasting Extends Lifespan At The Expense Of Fecundity In Daphnia, Meridith L. Smith

Undergraduate Honors Theses

Dietary restriction (DR) is a well-established intervention for extending lifespan, yet the specific efficacy of intermittent fasting (IF) and its associated trade-offs remain under-explored in many Daphnia magna. This study investigated the effects of three IF intervals—2h, 24h, and 48h—on the longevity and fecundity of two clones of Daphnia. We hypothesized that longer fasting intervals would significantly extend lifespan at the cost of reproductive output, consistent with the disposable soma theory of resource allocation.
Our results demonstrate that 24h IF significantly increased longevity relative to ad libitum controls, even outperforming caloric restriction (CR) by reducing late-life mortality. In …

Unravelling Taxonomic Complexity In Elusive Cetaceans: Mitogenome Insights Into Evolutionary History And Cryptic Diversity Of Bryde's Whales, Dominique Paynee, Paulette Bloomer, Gwenith Penry, Simon Elwen, Ada Natoli, Vaisakh Dhanalakshmy, Thyago Cardoso, Els Vermeulen

All Works

Cetaceans, despite their ability to cross wide distances, enabling mostly high levels of gene flow, can develop unique genetic lineages driven by variations in life-history traits, diverse migratory routes and local adaptation, complicating taxonomy and delineation of conservation units. Comprehensive genetic data are essential to overcome the challenges of obtaining suitable sample sizes from wild cetaceans while untangling cryptic species diversity. The Bryde's whale (Balaenoptera edeni) has a complicated discovery and taxonomic history that hinders accurate conservation assessments. In southern Africa, two populations are recognised: the inshore (SAi) and the offshore southeast Atlantic population (SEA). This study examines their phylogenetic …

Anxious Impairment: Exploring Executive Functions And Anxiety In College Students, Dawson C. Mathis

Masters Theses and Doctoral Dissertations

College students are tasked with juggling a variety of responsibilities. To manage these responsibilities college students must rely on their executive functioning (EF). Executive function refers to cognitive processes that are used to set goals, make plans to achieve those goals, and shift between tasks when necessary. A large portion of college students report experiencing anxiety and anxiety has been theorized to negatively impact cognitive performance, generally. This study sought to explore the impact of anxiety on inhibition and vigilance performance. Participants’ anxiety scores significantly correlated with the number of omission errors made on the inhibition task. Participants also made …

Unsupervised Discovery And Validation Of Affective Engagement States Using Synchronized Eeg And Eye-Tracking During Digital Learning, Menekse Adar

Masters Theses and Doctoral Dissertations

This study explores affective engagement states in digital learning environments using synchronized EEG and eye-tracking data. EEG signals were collected from frontal channels and processed using sliding windows to extract band-power features. Frontal Alpha Asymmetry (FAA; log alpha power difference, F4–F3) and the Beta–Alpha ratio (BA; log beta/alpha power ratio) were used as affective proxies. Instead of predefined emotion labels, unsupervised clustering methods were applied to identify latent engagement patterns directly from EEG features. To ensure robustness, non-overlapping parity analysis and hold-out validation were performed. Statistical tests were conducted to compare FAA and BA values across the identified clusters. Results …

Dean's Research Newsletter, May 2026, Neil W. Schluger

SOM Dean's Research Newsletter

No abstract provided.

Attachment And Betrayal: Post-Infidelity Attachment Issues With A Focus On Gender, Taylor Forsythe

Electronic Theses and Dissertations

Infidelity represents a significant relational trauma that may disturb attachment processes such as trust, emotional intimacy, and closeness. There is a gap in the literature on how different infidelity exposures may relate to these attachment responses; more so, there is a dearth of information on the gender differences for attachment issues following any kind of infidelity. The purpose of this study aimed to examine differences in avoidant and anxious attachment across infidelity groups (no infidelity, non-sexual infidelity, sexual infidelity), and a further comparison of gender differences in those groups. Participants (N = 151) completed online surveys in a larger study …

A Phenomenological Study Of Teachers Who Use Oral Reading To Foster Student Reading Fluency And Engagement, Donyetta Grimes

Dissertations

The National Reading Panel (2000) recommends oral reading instruction as a means to improve overall reading fluency and reading comprehension. Oral reading fluency is a necessary foundational skill, and students who have not mastered it by the end of third grade, when students transition from learning to read to reading to learn, become struggling adolescent readers (Ming, 2018). Furthermore, there is a lack of research on reading fluency past the primary grades (Makebo et al., 2022). Additionally, research gaps exist when considering teachers’ actual practices during reading instruction (O’Sullivan et al., 2009). This gap is particularly concerning considering that teachers …

Science For All: Utilizing Native And Everyday Language To Increase Academic Performance And Student Engagement For High School English Language Learners, Lashanda K. Whitworth

Dissertations

In public high schools across the U.S. high stakes assessments are seen as a lever to facilitate high-quality education and to gauge student learning. English Language Learners are mainstreamed into content classes and despite having low English proficiency scores are expected to perform as well as English first students and are required to take district and state mandated biology assessments. At the research site, ELLs comprise 25% of students and consistently score below the other subgroups in biology. This quasi-experimental study tested whether using disaggregate instructional strategies—incorporating ELLs’ native and everyday language—increases learning gains, academic growth, and engagement in a …

Unified Deep Learning Techniques For Spatial Detection And Temporal Forecasting Across Visual Domains, John Olawale Olamofe

All Dissertations

This dissertation proposed a unified deep learning framework for spatial detection and temporal forecasting across visual domains, designed to address limited supervision, class imbalance, and scale variability. The framework was structured around four complementary principles: Domain-Aware Input Rebalancing, Representation-Centric Learning, Diversity-Driven Robustness, and Transfer Across Scale and Modality, which together enabled robust visual representation learning across heterogeneous data sources.

Domain-Aware Input Rebalancing mitigates non-uniform and sparse data distributions by actively reshaping inputs before learning via class-aware augmentation, sampling, resolution manipulation, and super-resolution. This principle underpins object detection in overhead satellite imagery (xView), dense urban aerial scenes (CADOT), temporally sparse NDVI …

Molecular Mechanisms Of Pfas Induced Protein Dysfunction: Implications For Neurodegenerative Risk, Daisy Lee Wilson

Open Access Theses & Dissertations

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants with widespread human exposure and well-established links to adverse health outcomes. However, despite increasing epidemiological and experimental evidence, the molecular mechanisms underlying PFAS-induced neurotoxicity remain incompletely defined. This dissertation investigates PFAS toxicity across biological scales, integrating protein biophysics with neuronal cell models to elucidate pathways relevant to neurodegeneration. At the molecular level, we demonstrate that PFAS disrupts the structure and function of globular proteins, including the impairment of α-lactalbumin's calcium-binding capacity and of β-lactoglobulin's retinol binding, through concentration-dependent conformational destabilization. By applying these findings to a neuronal model, we show that …

Riemannian Manifold-Coupled Joint Sparse Graphical Models For Spatially Structured Precision Matrix Estimation, Abdul Rahman Adam

Open Access Theses & Dissertations

This thesis introduces a novel geometry-aware framework for joint precision matrix estimation in spatially structured data. Unlike existing joint Gaussian graphical model estimators that rely on Euclidean coupling mechanisms such as fused or group graphical lasso, our approach incorporates intrinsic Riemannian geometry through geodesic distance penalties on the symmetric positive definite manifold.

The method measures similarity between precision matrices of adjacent spatial regions using the affine-invariant Riemannian distance, capturing deformations of concentration ellipsoids rather than entrywise differences. This is particularly suited for spatial transcriptomics, where regions may share dependence structures despite differences in scale or composition.

An efficient Alternating Direction …

Comparative Case Studies Of How General Chemistry Ii Students Explain Entropically-Driven Phenomena, Raymundo Aragonez

Open Access Theses & Dissertations

Understanding how students conceptualize entropy remains a central challenge in chemistry education. Often referred to as a "driving force" of chemical reactions, the dispersal of energy as a process proceeds is indicative of a process's spontaneity or thermodynamic favorability. Students frequently default to discussing phenomena in deterministic terms, potentially reflecting the language choice and heuristics selected by the instructor such as "disorder". In this study, assessment prompts about entropy from a convenience sample of general chemistry textbooks were characterized as to their potential to elicit three-dimensional learning, and students' responses to assessment prompts from a curriculum aligned with three-dimensional learning …

Bayesian Deep Learning For Photovoltaic Power Forecasting: A Probabilistic Framework For Uncertainty Quantification And Grid Reliability Optimization, Pablo Abraham Bustamante

Open Access Theses & Dissertations

The global energy landscape is undergoing a profound transformation, driven by the urgent need to decarbonize power systems, enhance energy security, and meet growing electricity demands. Solar photovoltaic (PV) power has emerged as a critical component of future energy infrastructure due to its abundance, scalability, and cost-effectiveness. However, PV generation is inherently variable and weather-dependent, introducing significant uncertainty into grid operations and complicating the task of balancing supply and demand. Accurate forecasting of PV power generation-particularly on day-ahead and hour-ahead horizons-has become a strategic necessity for grid stability, economic efficiency, and environmental sustainability. PV output is influenced by numerous factors, …

Computational Studies Of Dna-Wrapped Carbon Nanotubes: From Enantioselective Dna Binding To Molecular Recognition Of Small-Molecule Analytes, Sayantani Chakraborty

Open Access Theses & Dissertations

Single-walled carbon nanotubes (SWCNTs) exhibit chirality-dependent optoelectronic properties and near-infrared fluorescence that make them promising platforms for biosensing. When functionalized with single-stranded DNA (ssDNA), SWCNTs form conjugates capable of selective molecular recognition. However, the molecular mechanisms governing chirality recognition and analyte-induced optical modulation remain incompletely understood. This dissertation investigates these mechanisms through an integrated computational approach combining molecular dynamics simulations, enhanced sampling techniques, and machine learning. First, atomistic molecular dynamics (MD) and replica exchange MD simulations were used to investigate how short ssDNA sequences interact with enantiomers of (7,5) SWCNTs. Analyses of base stacking, nucleotide orientation, sugar-phosphate positioning, and contact …

From Covid-19 To Influenza: Transforming Public Health Surveillance Through Freeze-Drying Innovations, Rui Dong

Open Access Theses & Dissertations

Public health surveillance increasingly relies on wastewater-based epidemiology (WBE) as a non-invasive, community-level early warning system for infectious diseases like COVID-19 and influenza. However, detecting minute viral concentrations in complex wastewater matrices remains a significant analytical challenge. Traditional concentrating methods, such as ultrafiltration, are limited by high performance variability and significant viral signal loss due to necessary pretreatment steps, such as pre-clarification, which inadvertently discard solid-associated viral fractions. To address these limitations, this dissertation introduces and evaluates freeze-drying as a novel, pretreatment-free concentrating method for wastewater viral surveillance. By sublimating water, freeze-drying uniquely retains both liquid and solid-phase viruses within …