Digital Commons Network^™

Substance Use Amongst Veterans Following Post-Deployment Reintegration: An Examination Through The Lens Of Acculturation, Brittany Hampton

Electronic Theses and Dissertations

Each year, approximately 46.3 million Americans are diagnosed with substance use disorder (SUD), which costs the United States healthcare system approximately $13 billion in annual costs. One group particularly at risk for SUD is veterans due to the unique stressors that veterans face (e.g., being apart from loved ones, exposure to life threatening events, transitioning between military and civilian life) and a military culture that often reinforces maladaptive patterns of substance use. Little research has been done to examine substance use as a negative outcome associated with the acculturative experience veterans face when transitioning from military life back to civilian …

Pi3k Signaling And Its Role In Cardiac Morphogenesis, Rabina Shrestha

Electronic Theses and Dissertations

The formation of the heart tube in vertebrates involves the coordinated movement of bilateral myocardial precursors to the midline, where they merge in a process known as cardiac fusion to form the primitive heart tube. While external influences from the anterior endoderm and the endocardium are known to be essential for cardiac fusion, intrinsic myocardial mechanisms are less understood. Here, we identify an intrinsic PI3K-dependent mechanism directing myocardial cells toward the midline during cardiac fusion. We found that inhibiting the PI3K pathway throughout the embryo using chemical inhibitors and injection of dnPI3K mRNA results in cardiac fusion defects. PI3K-inhibited embryos …

Isolation Of Novel Myxobacteria And Progress Towards Heterologous Expression Of Uncharacterized Secondary Metabolites, Andrew Ahearne

Electronic Theses and Dissertations

Myxobacteria, first observed by Roland Thaxter in the late 19th century, are known for their unique swarming behavior, complex fruiting body formation and biosynthetic potential. Myxobacteria are noted for their large genomes and the presence of numerous biosynthetic gene clusters (BGCs) that hint at their potential to produce novel metabolites with therapeutic properties. Isolation of myxobacteria utilizing E. coli and filter paper baiting yielded 20 myxobacteria isolated from rhizospheric soil samples in North America. Among these isolates, nine were identified as novel species, representing the genera Archangium, Myxococcus, Nannocystis, Polyangium, Pyxidicoccus, Sorangium, and Stigmatella. Comprehensive growth profiles, biochemical assays, and …

Make It Funny! Developing A Novel Humor-Based Digital Positive Psychology Intervention To Investigate The Influence Of Duchenne Laughter And Mirth On Psychological Distress In Daily Life, Joshua Semko

Electronic Theses and Dissertations

The aim of the present research was to develop a novel digital humor-based PPI (Make it Funny!) to investigate the influence of Duchenne laughter and mirth on psychological distress in daily life. Participants (N = 159; Agemedian = 39 years; 47.77% biologically female; 68.15% White) were tasked with completing Make it Funny! or a placebo activity every day for 7 days. Duchenne laughter frequency had a small negative cross-sectional moderation effect on the relationship between the occurrence of stressful events and psychological distress (t(79.71) = -2.33, b = -10.89, p = .022). Within participants, Duchenne laughter frequency slightly increased the …

Formulation Development Of Simvastatin Self-Emulsifying Drug Delivery System Using Hot Melt Extrusion, Srikanth Chilamula

Electronic Theses and Dissertations

Simvastatin, a potent HMG-CoA reductase inhibitor, lowers cholesterol levels. It prevents cardiovascular events like heart attacks and strokes in patients with high cholesterol and heart disease. However, its oral bioavailability is limited due to its poor aqueous solubility The current study aims to enhance the solubility of the poorly water-soluble drug simvastatin through the development of self-emulsifying drug delivery systems (SEDDS). Gelucire® 48/16 (oil), Gelucire 44/14 (surfactant), and Cremophor RH40 (co-surfactant) were assessed as potential excipients for SEDDS formulation. Initial SEDDS (Before adsorption) formulations were created based on the solubility of simvastatin in solid lipid excipients, as determined by a …

Formulation Design And Development For Extended-Release Drug Delivery System, Sheng Feng

Electronic Theses and Dissertations

The drug delivery system enables the release of the active pharmaceutical ingredient to achieve a desired therapeutic response. Conventional, non-controlled drug delivery systems are unable to deliver the drug at a sustained rate which leads to poor bioavailability, fluctuations in plasma drug concentration, and potential side effects. The extended drug delivery system enables drug delivery at a sustained or predetermined rate to achieve maximum efficacy and safety. Different routes of drug administration, along with various extended-release dosage forms have been extensively developed such as oral delivery, parenteral delivery, transdermal delivery, ocular delivery, and tumor delivery among others. This dissertation developed …

Efficient Design Of Neural Network Hardware Accelerator For Enhanced Performance In Deep Learning Systems, Tamador Nadem Mohaidat

Electronic Theses and Dissertations

Artificial intelligence (AI) hardware accelerator is an emerging research for several applications and domains. The hardware accelerator aims to provide high computational speed while retaining low cost and high learning performance. The main challenge is to design complex machine learning models on hardware with high performance. In this thesis, the aim is to develop the hardware implementation of perceptron within a neural network. Innovative hardware-based approaches are explored to optimize perceptron networks, enhancing accuracy, reliability, and fault tolerance while minimizing resource requirements and power consumption.

A thorough investigation into machine learning accelerators and associated challenges was initially conducted. The hardware …

Heterologous Expression, Isolation, And Metabolomic Profiling Of Myxobacteria To Explore Their Potential In Natural Product Biosynthesis, Nawal Mohamed Hamed Elsayed Shehata

Electronic Theses and Dissertations

Myxobacteria are distinguished by their ability to produce a spectrum of natural products,positioning them as an active resource for therapeutic discovery. These products include metabolites with significant antibacterial, antifungal, cytotoxic, antiviral, and immunosuppressive properties. Current synthetic biology tools for the exploration of myxobacteria are not as advanced as those for the well-studied Streptomyces. This thesis presents an evolution of synthetic biology techniques specifically designed for the exploitation of myxobacteria in the realm of natural product discovery. Chapter One investigates the potential of myxobacteria to act as heterologous hosts due to their large genomes and their capacity for diverse biosynthetic processes. …

An Argument Against Positivist Separability, Nichalus Zoltan Vali

Electronic Theses and Dissertations

One of the most influential views associated with legal positivism is that of the separability thesis. Primarily associated with H.L.A Hart, this thesis is widely understood to be the view that there is no necessary connection between law and morality. However, John Gardner takes this to be a naïve interpretation of separability that fails to adequately characterize legal positivism and which Hart himself did not endorse. Instead, Hart and other legal positivists were committed to the view that whether a norm is legally valid depends on its sources (i.e., social facts such as official engagement with the norm) and not …

Atomistic Simulation Of Pfas And Graphene: Interactions For Water Applications, Bashar Moufeed Awawdeh

Electronic Theses and Dissertations

The contamination of drinking water by per- and polyfluorinated alkyl substances (PFAS) is a global issue. PFAS have been widely utilized in a variety of applications, including water and stain-resistant coatings, fire suppression foams, cosmetics, paints, and adhesives. They have been detected in soils and rivers globally due to their widespread use and resistance to degradation. The strong C–F bonds of PFAS make them exceedingly stable and hard to remove. In order to remediate PFAS contamination in the environment, it is essential to develop selective adsorbent materials that can effectively capture a wide range of PFAS structures. On April 10, …

Cationic Charge-Shifting Polymers As Improved Vectors For Nucleic Acid Delivery, Alexander Fortenberry

Electronic Theses and Dissertations

This work investigates the development and application of charge-shifting polycations for gene delivery, focusing on their synthesis, characterization, and applications for in vitro mRNA delivery. Utilizing poly(2-vinyl-4,4-dimethylazlactone) (PVDMA), this study explores modifications with various reactive handles, such as alcohol, thiol, and amine groups, to create cationic amide-, ester-, and thioester-functionalized polycations. These modifications aim to exploit the charge-shifting capabilities of the polycations to form stable polyplexes with nucleic acids, promoting the efficient intracellular release of the genetic cargo.Initial studies first examine the charge-shifting properties of PVDMA-based polycations under different pH and temperature conditions. This work highlights the potential of these …

Ecological And Evolutionary Ramifications Of Host-Parasite Interaction In Aquatic And Model Ecosystems, Akacia Halliday-Isaac

Electronic Theses and Dissertations

Host-parasite interactions are ubiquitous and have negative risks and consequences on individual, population, and evolutionary scales. These risks and consequences include altered population densities, changes in interspecies interactions, and rapid changes in host phenotypes. In this thesis, I seek to understand the ecological and evolutionary ramifications of host-parasite interactions within ecosystems. To do this, I investigated the presence and environmental correlates of potential host-parasite interactions in a freshwater ecosystem and used a model ecosystem to explore how past host-parasite coevolution affects community assembly dynamics and future adaptation in the presence of new stressors. To examine the presence of potentially parasitic …

Acoustic Localization In Reverberant Environment, Xing Yang

Electronic Theses and Dissertations

The main goal of this dissertation is to develop algorithms to accurately locate and detect underwater oil leakages through sounds emitted by oil-induced bubbles recorded by passive hydrophones. These algorithms aim to create an early warning system to prevent or identify catastrophic oil spills from pipelines, wellheads, and seafloor seepage.

Effects Of Off-Season Fall-Winter Farm Field Flooding On Nitrogen Gas Production, Andrew Rosson

Electronic Theses and Dissertations

Increased nitrogen (N) fertilizer use and cultivation of N-fixing crops have dramatically increased agricultural N inputs to the global N cycle. Excess N on agricultural lands is highly susceptible to loss through runoff or atmospheric emissions, potentially as a greenhouse gas (GHG). Nitrous oxide (N2O), a GHG with a warming potential ~300 times that of carbon dioxide (CO2), primarily enters the atmosphere through denitrification, which converts bioavailable nitrate (NO3-) to inert nitrogen gas (N2), with N2O as an intermediate. Wetlands are crucial for de-nitrification and N regulation due to their wet, anoxic soils, but have declined worldwide, including substantial losses …

Exploring African American Female Students' Choice Of Stem Major At Rust College, Shatara Hall

Electronic Theses and Dissertations

In comparison to the rest of the United States population, African American women are undeniably inadequately represented in the fields of science, technology, engineering, and mathematics (STEM). As one of the oldest historically black colleges in Mississippi, Rust College has the social responsibility to increase the presence and contributions of minorities in STEM. Since the enrollment of African American females is greater than that of African American males at Rust College, the college has the fortuity to assist in increasing the diversity in STEM for both race and gender. This DIP utilizes Intersectionality Theory as the conceptual foundation to explore …

Formulation And Characterization Of Clotrimazole Buccal Films Using Hot Melt Extrusion, Harish Kandhuri

Electronic Theses and Dissertations

Clotrimazole is a broad-spectrum antifungal /antimycotic, it is used topically in the treatment of oropharyngeal candidiasis. The oral route is the most preferred route of administration 60% of the conventional dosage forms are available as tablets and capsules. The main objective of the study was to develop and Formulate Clotrimazole oral film to get local effect for treating oropharyngeal candidiasis. Oral films are thin flexible strips which can be placed on the tongue, where it adheres to the surface of the tongue and dissolves releasing the drug into the oral cavity. Here, the films are formulated using hot melt extrusion …

Grace Satellite Spatial Resolution Downscaling Using Machine Learning: Methods And Applications, Abdel Rahman M. Awawdeh

Electronic Theses and Dissertations

The Gravity Recovery and Climate Experiment (GRACE) satellite mission has been instrumental in advancing our understanding of global water dynamics, providing unprecedented insights into terrestrial water storage (TWS). Despite its revolutionary contributions, the coarse spatial resolution of GRACE data (~300 km² grids) limits its utility for local-scale water resource management, particularly in regions requiring detailed hydrological analysis such as the Mississippi Delta. This dissertation addresses this limitation by developing and validating machine learning models to enhance the spatial resolution of GRACE data, thereby facilitating more precise and effective local water management strategies.

This research first establishes a comprehensive background in …

Increasing Minority Student Enrollment: An Applied Research Study On Increasing The Enrollment Of Minority Students In Advanced Placement Courses, Tamekia Helm

Electronic Theses and Dissertations

Addressing the disparity in Advanced Placement (AP) course enrollment among minority students at Greater High School is the focus of this research. Through an extensive review of the literature, the study examines the various factors contributing to this gap, including access limitations and systemic barriers. Additionally, teacher perceptions, student attitudes, and parental involvement are explored to understand the influence on AP course enrollment decisions. Utilizing a mixed-methods approach, including surveys and interviews, data is collected from students, teachers and parents to gain comprehensive insights.

Proposed solutions to enhance AP course enrollment include targeted outreach initiatives and support for minority students. …

Indirect And Direct Pathways Of Migratory Shorebird Effects On Nitrogen Cycling Within Temporarily Flooded Agricultural Fields, Victoria Blocker

Electronic Theses and Dissertations

The global human population continues to grow exponentially, and agriculture will need to become more productive to meet growing food demands. Humans also need clean water and other services that ecosystems provide. This requires future agriculture production to reduce environmental and wildlife impacts through improved efficiencies and best management practices. Migratory shorebirds rely on wetlands throughout North and South America as stopover habitat for rest and refueling during migration. Temporarily flooded farmlands in the Mississippi Delta have proven to be beneficial locations for shorebirds during migrations along the central flyway. This conservation practice also enhances wetland properties that promote excess …

Perceived Linguistic And Non-Linguistic Barriers Facing Saudi Female Partners Learning English, Samah Mohamad Dulli

Electronic Theses and Dissertations

The partners of the Saudi students who come to the United States on scholarships to earn a degree (Bachelor's, Master's, or Ph.D.) are eligible for full scholarships as well. However, most of them fail to proceed in earning a degree or fulfill the language proficiency requirement needed to join an academic degree program. This study surveys between 10 to 20 adult female partners of Saudi university students to elicit their opinions on how much English they think they will learn during their partner scholarship time in academic and non-academic settings. This study investigates the female partners of the Saudi degree …

Punishing Poverty: An Examination Of Financial Disadvantage And Out-Of-School Suspension, Joshua Rosenbaum

Electronic Theses and Dissertations

School suspension is often a response by officials to address deviant behavior within the school setting. While studies have examined various causes and consequences of school suspension, there is a dearth of literature focusing on the effects of financial disadvantage on school discipline (i.e., school suspension). Given that out-of-school suspension is a reliable predictor of juvenile justice involvement later in life, it serves as an important outcome variable in preventative criminology. Using data from the National Longitudinal Study of Adolescent to Adult Health (Add Health), the purpose of the current study is to analyze the relationship between financial disadvantage and …

Ftir Microspectroscopy For The Investigation Of Microplastic Pollution, Automotive Paint Layers, And Prehistoric Rock Paint With An Emphasis On Analytical Method Development, Kendall Wontor

Electronic Theses and Dissertations

The research detailed in this dissertation centers on the development of new analytical methods using chemical imaging microspectroscopy, primarily μ[micro]-FTIR, for applications in environmental, forensic, and archeological chemistry. The state-of-the-art instrument (LUMOS II) used in this research combines optical microscopy with IR spectroscopy, allowing sample visualization during FTIR imaging and micro-analysis.

Chapter 1 serves as an introduction and provides background detail on the instrumentation and technique. Chapter 2 describes the use of fluorescent microscopy to quantify microplastics (MPs) in oysters from the Mississippi Sound. High concentrations of putative MPs were found, with sites inside bays near population centers displaying higher …

Breaking Old: Trends And Adverse Events Of Prescription Stimulant Use In Older Adults, Saumil Jadhav

Electronic Theses and Dissertations

This dissertation examined prescription stimulant medication (PSM) use among older adults in the United States from 2012-2020 by (1) assessing annual prevalence and describing clinical characteristics and treatment patterns among new PSM users, (2) evaluating the association between PSM initiation and risk of adverse events such as stroke, myocardial infarction, and all-cause mortality, and (3) analyzing trends in the concomitant use of PSMs and antidepressants. The study utilized 5% national sample of Medicare administrative claims from 2012-2020.

First, the study identified an increase in the annual prevalence of PSM use from 0.44% in 2012 to 0.63% in 2020 among older …

Formulation And Characterization Of Quetiapine Fumarate Floating Bioadhesive Tablets, Ajay Reddy Kolipaka

Electronic Theses and Dissertations

Quetiapine fumarate (QF) is an antipsychotic drug, and it has a plasma half-life of 6 hours. The chemical structure of QF has nitrogen groups making it highly soluble in acidic pH and slightly soluble in alkaline pH. This study aimed to develop the QF gastroretentive tablets by TSMG technology comprising floating and mucoadhesive approach by using different viscosity grades of HPMC to improve absorption by prolonging its gastric residence time. The floating tablets were prepared using the Twin screw melt granulation (TSMG) technology, and the impact of polymer concentration and viscosity grades of HPMC on the floating ability and drug …

Bacterial Metallophores As Potential Agents In Heavy Metal Bioremediation, Mohammed Ahmed

Electronic Theses and Dissertations

Heavy metal pollution is a significant threat to human health and the environment. Bacteria have evolved diverse mechanisms to adapt to these pollutants, including the secretion of small molecules called metallophores. Bacterial metallophores are metabolites excreted in response to toxic metal stress to protect the bacterial cell. These small molecules have shown versatility in potential applications for the remediation of heavy metals. This research focuses on constructing a library of bacterial metallophores, which will facilitate the assessment of their metal-binding properties when exposed to different metals. The study has two main areas of investigation: Firstly, it involves isolating and characterizing …

Research News, Publications, 2024, Volume 2, Soumyajit Majumdar

Publications (2015-)

Publications that appeared during the period of April 1 through June 30, 2024.

Research News, Publications, 2024, Volume 3, Soumyajit Majumdar

Publications (2015-)

Publications that appeared during the period of July 1 through September 30, 2024.

Research News, Publications, 2024, Volume 4, Joshua Sharp

Publications (2015-)

Publications that appeared during the period of October 1 - December 31, 2024.

Research News, Grants, 2024, Volume 3, Soumyajit Majumdar

Grants (2015-)

Grants and contracts awarded during July - September 2024 - Revised 10/22/24

Application Of Hot-Melt Extrusion Technology For The Preparation Of Carbamazepine Extended-Release Tablets, Chamundeswara Srinivasa Akash Kalla

Electronic Theses and Dissertations

Carbamazepine (CBZ) is an anti-convulsant and specific analgesic for trigeminal neuralgia that reduces polysynaptic responses and blocks post titanic potentiation. Moreover, CBZ is effective in partial and generalized convulsions and mixed types. It is not effective in petit mal seizures. Carbamazepine extended-release tablets are used to treat episodes of mania (or) mixed episodes i.e., symptoms of mania and depression that happen at the same time, in patients with bipolar disorder. The present study was designed to develop CBZ extended-release tablets with acrylic acid-based polymer (Eudragit® RL PO) using a melt granulation and to match the USP dissolution test specification. Thermal …