Digital Commons Network^™

Statistical Methods For Assessing Treatment Effects On Ordinal Outcomes And Selecting Optimal Treatment On Survival Outcomes Using Observational Data., Huirong Hu

Electronic Theses and Dissertations

This dissertation consists of two projects investigating statistical methods in causal inference and personalized medication using observational data. In the first project, we propose a parametric marginal structural ordinal logistic regression model (MS-OLRM) to assess treatment effects on ordinal outcomes. Average treatment effect (ATE) is used to measure the difference of the mean outcomes if all patients would have been treated compared with the outcomes if they would not have been treated. Many statistical methods have been developed to estimate ATE when the outcome is continuous or binary. The methodology on assessing treatment effect for an ordinal outcome is less …

Tropical Understory And Canopy Twig Ants (Pseudomyrmex): Natural History, Sensory Homing, And Neuroecology., Daniella Prince

Electronic Theses and Dissertations

In this dissertation, I examined the behavior of foraging twig ants, explored the sensory profile of their homing behavior, and investigated the role of habitat use in shaping the sensory neurobiology of species within the genus Pseudomyrmex (Hymenoptera: Formicidae). In chapter one, I reviewed the ecology of Pseudomyrmex, and introduced the focal species, P. boopis, a neotropical understory-dwelling twig ant. In chapter two, I described the natural history of P. boopis on Barro Colorado Island, Panama—specifically, their nesting habits, activity rhythm, and foraging behavior on understory surfaces. Pseudomyrmex boopis colonies were diurnal and nested in dead twigs in …

Intercalation And High-Pressure Investigations Of Black Arsenic Phosphorus: Unraveling Material Transformations., Dinushika Vithanage

Electronic Theses and Dissertations

Black arsenic phosphorus (b-As_yP_1-y) alloys have emerged as intriguing materials within the realm of two-dimensional (2D) materials, following the discovery of black phosphorus (BP). These alloys possess capability to overcome major limitations of BP and exhibit potential for tunability and enhancement of properties making them promising materials for a wide range of applications, including lithium-ion batteries. Inspired by the intriguing findings obtained for BP, this research focuses on understanding the structural modifications that can be achieved in b-As_yP_1-y alloys through the application of intercalation and high pressure. The initial phase of our investigation …

From Androgyny To Binary And Back: A Qualitative Analysis Of Nonbinary Tiktoks., Savannah Hatton

Electronic Theses and Dissertations

This study explores how nonbinary individuals represent and express their gender on TikTok. Given the limited amount of research that has been done on nonbinary gender expression in online spaces, this study uses TikTok to observe the ways that nonbinary individuals perform gender. Additionally, given the relative newness of TikTok, this study serves to inform growing research on identity formation through social media. It used a sample of fifty TikToks by nonbinary creators to perform a content analysis. The findings reveal significant variation in how nonbinary individuals "do gender" on the platform, with some individuals identifying closely with binary labels, …

Aurka Inhibition-Based Combination Therapy Approaches In Glioblastoma., Muge Sak

Electronic Theses and Dissertations

Glioblastoma is the most common and aggressive central nervous system tumor in adults with a 6% survival rate. Decades of research for improving life expectancy and quality of life have been ineffective. The discovery of better treatment strategies is urgent to improve the survival rates for glioblastoma patients. Aurora Kinase A is a regulator of tumor progression and is overexpressed in glioblastoma. We used a specific Aurora Kinase A inhibitor alisertib in combination with DNA-damaging platinum agent carboplatin or brain-penetrating taxane TPI 287. We investigated the efficacy of these combinations in treating in vitro and in vivo tissue culture models …

A Data-Driven Multi-Regime Approach For Predicting Real-Time Energy Consumption Of Industrial Machines., Abdulgani Kahraman

Electronic Theses and Dissertations

This thesis focuses on methods for improving energy consumption prediction performance in complex industrial machines. Working with real-world industrial machines brings several challenges, including data access, algorithmic bias, data privacy, and the interpretation of machine learning algorithms. To effectively manage energy consumption in the industrial sector, it is essential to develop a framework that enhances prediction performance, reduces energy costs, and mitigates air pollution in heavy industrial machine operations. This study aims to assist managers in making informed decisions and driving the transition towards green manufacturing. The energy consumption of industrial machinery is substantial, and the recent increase in CO2 …

Cad System For Early Diagnosis Of Diabetic Retinopathy Based On 3d Extracted Imaging Markers., Ahmed Sleman

Electronic Theses and Dissertations

This dissertation makes significant contributions to the field of ophthalmology, addressing the segmentation of retinal layers and the diagnosis of diabetic retinopathy (DR). The first contribution is a novel 3D segmentation approach that leverages the patientspecific anatomy of retinal layers. This approach demonstrates superior accuracy in segmenting all retinal layers from a 3D retinal image compared to current state-of-the-art methods. It also offers enhanced speed, enabling potential clinical applications. The proposed segmentation approach holds great potential for supporting surgical planning and guidance in retinal procedures such as retinal detachment repair or macular hole closure. Surgeons can benefit from the accurate …

Connectivity Of Amygdala Somatostatin-Expressing Neurons And Their Role In Taste-Guided Behavior., Jane Jeruto Bartonjo

Electronic Theses and Dissertations

The nucleus of solitary tract (NST) and parabrachial nucleus (PBN) represent the first and second central synapses of ascending gustatory information. Neural processing in these nuclei is influenced by descending input from forebrain regions such as the central nucleus of the amygdala (CeA). In mice, we have shown that somatostatin (Sst) expressing neurons of CeA that project to NST and PBN are largely distinct cell populations and optogenetic inhibition of the CeA/Sst-to-NST subpopulation increases the intake of high concentrations of quinine with no apparent effect on sucrose intake. Synaptic connectivity of these cells is needed to understand the possible mechanisms …

Experimental And Numerical Studies Of Laser Powder-Bed Fusion Process With Ti-6al-4v Powder: (1) Porosity And Mechanical Properties, And (2) Transient Phenomena In One- And Two-Dimensional Fabrications., Santosh K. Rauniyar

Electronic Theses and Dissertations

Laser powder bed fusion (L-PBF) process represents a form of metal additive manufacturing (AM) where micron-level powdered material is selectively melted and fused layer by layer to create intricate three-dimensional parts. This process involves rapid melting and solidification, leading to intense thermocapillary convection within the molten pool. The melt pool is a crucial element of the L-PBF process and refers to the localized region where the powder particles are melted and solidified to form each layer of the printed part. The shape and dimensions of the melt pool directly influence the accuracy and surface finish of the printed part. Precise …

Using Graphic Novels To Teach Economics Content To High School Students With Extensive Support Needs., Caroline Mae Fitchett

Electronic Theses and Dissertations

The purpose of social studies instruction in school is to facilitate the growth of competent citizens (National Council for the Social Studies [NCSS], 2013). Despite the recognized benefit of social studies instruction, emphasis on this subject has decreased over time, and has ultimately been termed a “dispensable subject” (Fitchett & Haefner, 2010). Social studies is an even more marginalized subject area for students with disabilities (Zakas et al., 2013). Expanding the research in this area is not only necessary to improving social studies academic content acquisition but is also likely to facilitate greater independence for students post-school – and by …

Perception Is Reality! How Perception Shapes Our World., Nicole Clay

Electronic Theses and Dissertations

This thesis is an examination of the role different photography techniques play in how images are perceived. There have existed techniques for manipulating the perception of images since the creation of the camera. The techniques examined in this paper are editing, staging, and the use of captions. In recent years, perception has become a powerful tool for political parties to manipulate. This manipulation of perception has led to an increasing distrust in the images the media presents to the public. This paper does not seek to answer any questions but to encourage people to have a greater understanding of photography.

The Role Of E-Liquid Constituents In E-Cigarette-Induced Cardiac Arrhythmia And Autonomic Imbalance., Cory Kucera

Electronic Theses and Dissertations

Introduction. Accumulating evidence indicates that exposure to electronic cigarettes (e-cigs) promotes sympathetic dominance and electrophysiologic instability in the heart, potentially culminating in arrhythmogenesis. E-liquids contain various formulations of nicotine and flavorings, but the effects of specific e-liquid constituents and their concentrations on e-cig-induced autonomic imbalance and electrical dysfunction are unresolved. To that end, we tested the hypothesis that e-cigs modify cardiac autonomic balance and ventricular arrhythmogenesis in mice dependent on e-liquid constituent type and concentration. Methods. Using a crossover design and a serial exposure regimen, ECG-telemetered male C57BL/6J mice underwent whole-body exposure to e-cig aerosols generated from e-liquids containing different …

Penalized Bayesian Exponential Random Graph Models., Vicki Modisette

Electronic Theses and Dissertations

Networks have the critical ability to represent the complex interconnectedness of social relationships, biological processes, and the spread of diseases and information. Exponential random graph models (ERGM) are one of the popular statistical methods for analyzing network data. ERGM, however, struggle with computational challenges and degeneracy issues, further exacerbated by their inability to handle high-dimensional network data. Bayesian techniques provide a promising avenue to overcome these two problems. This paper considers penalized Bayesian exponential random graph models with adaptive lasso and adaptive ridge penalties to perform variable selection and reduce multicollinearity on a variety of networks. The experimental results demonstrate …

August 2023, Swosu Bulldog Wellness Committee

SWOSU BULLDOG WELLNESS

August is the time to celebrate National Wellness month

• Prioritize your self-care -------- Go to the spa.
• Manage your stress ------------- You will feel happier.
• Promote healthy routines ----- Attend a fitness class.

Chip- And System-Level Reliability On Sic-Based Power Modules, Pengyu Lai

Graduate Theses and Dissertations

The blocking voltage, switching frequency and temperature tolerance of power devices have been greatly improved due to the revolution of wide bandgap (WBG) materials, such as silicon carbide (SiC) and gallium nitride (GaN). Owing to the development of SiC-based power devices, the power rating, operating voltage, and power density of power modules have been significantly improved. However, the reliability of SiC-based power modules has not been fully explored yet. Thus, this dissertation focuses on the chip- and system-level reliability on SiC-based power modules. For chip-level reliability, this work focuses on on-chip SiC ESD protection devices for SiC-based integrated circuits (ICs). …

Determinants Of Market Participation Among Milk Producers In Kyrgyzstan, Akhmadjon Nurullaev

Graduate Theses and Dissertations

This study explores the key factors that drive milk producers to enter the milk market as sellers in Kyrgyzstan. The study utilizes the Life in Kyrgyzstan dataset, a nationally representative survey that tracks 3,000 households and 8,000 individuals throughout Kyrgyzstan. The results were analyzed with two different models: Heckman’s two-stage and the double hurdle models. The results show that regional location, ethnic group origin, risk awareness, dependency ratio, vehicle ownership, total value of assets, distance to agro market, and family shock occurrence significantly impact both market participation and the volume of milk sales. The findings hold great significance in establishing …

Market Outlet Choices Of Small-Scale Fruits And Vegetables Producers In Arkansas, Grace Sivilondire Mahamba

Graduate Theses and Dissertations

This thesis comprises two studies investigating the market outlet choices of small-scale fruit and vegetable producers in Arkansas. By examining the marketing decisions of producers in the region, the objective was to profile producers based on their utilization of different available outlets and identify the factors influencing their decisions regarding where to sell their products. Data from a survey conducted in the Ozark Mountain Region (comprising Arkansas, Southern Missouri and Eastern Oklahoma) during Fall of 2022 were analyzed using k-means clustering to classify producers based on their characteristics, thus establishing distinct producer profiles. Multinomial logit regression was employed to determine …

Non-Physical Abuse In Sports: Organizational Culture’S Role, Ian O'Rourke

Graduate Theses and Dissertations

The purpose of this study was to explore the perceptions of sport professionals who worked in organizations that tolerated non-physical abuse. This qualitative study used active interviewing and grounded-theory design to guide the data collection and coding efforts. The data identified emerging themes to generate essential theory. The research collected data through interviews with 10 sport professionals. This phenomenological study looked at sport professionals’ experiences who worked at private sport organizations and those that worked within a university athletic department. Interview responses illustrated that all participants experienced comparable treatment and felt similarly to the non-physical abuse taking place. An interesting …

Seeking And Providing Social Support In Online Forums For Individuals Experiencing Depression, Anna Gentry

Graduate Theses and Dissertations

This thesis project investigates how individuals suffering from depression seek support, provide support, and describe experiences of stigma in an online support platform. A phronetic-iterative and constant comparative approach guided an in-depth analysis of 37 posts on a discussion board designed for individuals with depression. The findings demonstrated that individuals use online discussion forums to request support both implicitly and explicitly. In response to sought support, individuals provided informational, emotional, and network support. Finally, discussion board participants discussed social and self stigma. Despite the limitations of the study, the findings indicate the utility of online social support platforms for individuals …

Understanding The Environmental And Genetic Influence On Fluctuating Asymmetry And Developmental Instability In Primates, Ashly N. Romero

Graduate Theses and Dissertations

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation …

Risk-Returns Of Forward Contracting Southern Row Crops With Crop Revenue Insurance, Chandan Bhattarai

Graduate Theses and Dissertations

This study evaluated the risk and return associated with various levels of forward contracting for southern row crops, specifically corn, soybean, and rice, in conjunction with different coverage levels of the Revenue Protection (RP) crop insurance program and government support plans. Forward contracting is a strategy to manage price risk by transferring ownership of physical grain from a seller to a buyer at a pre-agreed time. RP is a return-based crop insurance program offering coverage levels ranging from 50-85 percent in 5 percent increments, which allows producers to hedge against yield or price risks. Additionally, the study analyzed the effectiveness …

Functional Morphology Of The Platyrrhine Humerus And Talus: Implications For Inferring Locomotor Behavior In Extinct Primates, Liam Michael Zachary

Graduate Theses and Dissertations

Platyrrhines are a diverse radiation of primates that exhibit a range of locomotor adaptations. The relationships between extant primate locomotor behavior and variation in postcranial morphology are often used to make functional interpretations of skeletal anatomy in extinct primates. However, a comparative baseline of form-function relationships in the extant platyrrhine postcranium is lacking compared to other primates, which limits understanding of platyrrhine locomotor evolution. The humerus and talus are two of the best represented skeletal elements in the platyrrhine fossil record and are informative of locomotor behavior. Therefore, quantification of morphological variation in extant platyrrhine tali and humeri can provide …

A Phenomenographic Analysis Of Elementary Student Teachers’ Reflections Using Tiktok As A Resource For Classroom Management, Stefanie Lynn Mckoy

Graduate Theses and Dissertations

This phenomenographic study investigates how student teachers use TikTok to discover, analyze, evaluate, and adopt classroom management information and strategies. Student teachers often struggle with classroom management regarding student behavior, classroom environment, and instruction. To address these concerns, they turn to traditional print, digital, and human resources. Fifteen student teachers during the 2022-2023 school year were interviewed using a semi-structured guide. Transcripts were analyzed following a second order approach whereas the research examines student teachers’ perceptions. Four themes, resource discovery, TikTok analysis, evaluating credibility, and strategy adoption. Findings support the need for teacher preparation programs to incorporate exemplar examples of …

Optocoupler Integration Of Ltcc-Based Gate Driver In A Sic Power Module, Michael Oghenekome Otobo

Graduate Theses and Dissertations

The growing demand for electrical energy in today’s industrialized economy has driven the need for innovative approaches to meet diverse application requirements. Notably, advancements have been made in the field of power electronic systems, as reliable power electronic converters are essential for managing multiple power sources and loads. However, the development of these systems poses challenges related to power device switching speed, system weight and size, and power losses. The integration of a gate driver into a SiC power module offers a solution to many of these challenges, thereby driving the advancement of electrical power density expansion. An LTCC-based gate …

Racial Disparities In Women’S Imprisonment, Gift Onyinyechi Onwuadiamu

Graduate Theses and Dissertations

The total imprisonment rate in the United States, and racial disparity in imprisonment, have decreased substantially since 2008 (Carson, 2020), but research has not examined if disparity in women’s imprisonment rates has also declined, or what accounts for these changes. Guided by prior research and theory, this study examines racial differences in women’s prison admission rates from 2000 to 2019 in 25 states. Analyses examine changes over time, by state, and the effects of social structural characteristics that prior research has shown to be associated with women’s imprisonment disparities. Initial findings indicate that disparity has decreased, substantially, due to both …

Use Of Microorganisms For The Enrichment Of Zn And Se By Using Solid-State Fermentation, Rashmi Rangaswamaiah

Graduate Theses and Dissertations

Zinc (Zn) and selenium (Se) are essential minerals for human health and naturally found in many food sources. However, the risk of Zn and Se deficiency has been recognized in several countries. As most people throughout the world consume rice, grains, and cereals as staple foods in their daily diet, which contain a certain amount of phytic acid (antinutrients), the phytic acid content inhibits mineral absorption (Zn and Se) by the human body. Moreover, the low levels of Zn and Se content found in the crop's soil also reduce the amount of minerals in the food sources. Therefore, it is …

Molecular Characterization Of Compartment Boundary Formation During Epithelial Remodeling In Drosophila Melanogaster, Samia Parveen

Graduate Theses and Dissertations

The ability of epithelial cells to self-organize is crucial for the development of proper tissue structures and organs in multi-cellular organisms. Epithelia consist of inter-connected cells that form flat sheets, and specific groups of cells within these sheets are partitioned into distinct compartments via compartment boundaries (CBs). These CBs are specialized interfaces between cells characterized by stable, high-tension actomyosin cables, which act as fences to prevent movements between adjacent compartments during tissue reorganization. In the early Drosophila embryo, CBs are established in response to the asymmetrical localization of two cell-surface proteins the Leucine-Rich Repeat (LRR) protein Tartan and the Teneurin …

Characterizing Logistics Operations Within A Federal Staging Area For Hurricane Response: A Qualitative Analysis Of Federal, State And Local Perspectives, Jannatul Shefa

Graduate Theses and Dissertations

A successful deployment of logistics operations following a disaster is a collective contribution of federal, state, and local entities to ascertain an efficient and effective response. This research analyzes data from interviews with disaster response logistics experts from these entities. The objective is to investigate the information sources and planning processes used in these organizations to plan vehicle routes for critical resource deliveries to impacted areas. Special attention is directed to the impacts of incomplete knowledge of infrastructure status, such as road disruptions due to debris or flooding. Supported by both qualitative and quantitative evidence, the study finds that incomplete …

The Hidden Role Of Religiosity In Contemporary Public Education In The United States Of America, Marilyn Anderson Rhames

Graduate Theses and Dissertations

The ‘separation of church and state’ is a fundamental precept of the United States, yet the phrase itself is not written in the Constitution and even Supreme Court justices disagree on how it should be defined. The ambiguity surrounding religious liberty is perhaps most felt in K-12 public education, where the fear of inflicting faith formation on impressionable students has inspired the vision of a secular, God-neutral, government-run school system. As such, federal and state laws dictate that public school educators who coerce students by promoting or inhibiting religious devotion risk losing their jobs. Yet, the reality is that the …

Comparing Predictive Performance Of Garch And Stochastic Volatility Models, Swapnaneel Nath

Graduate Theses and Dissertations

This paper compares the predictive performance of two commonly used financial models, the Generalized Auto-Regressive Conditional Heteroskedasticity (GARCH) model, and the Stochastic Volatility model. Both techniques are used in the finance literature to model returns on an asset; the main difference between the two is that the former holds volatility as deterministic, whereas the latter treats it as a stochastic component. Three 10-year periods (2006-15, 2008-17, and 2010-19) of returns of the S&P-500 Index are used to train the two models. The parameter estimation is done using Hamiltonian Monte Carlo. Then, using Sequential Monte Carlo updates, returns for 2016, 2018, …