Digital Commons Network^™

Longevity In Afrikaner Cattle: A Survival Analysis, Allison M. Bot Steffl

Electronic Theses and Dissertations

The Afrikaner breed of cattle is indigenous to South Africa and due to their hardiness was once the most popular breed amongst farmers. The objectives for this study were to: (1) estimate environmental effects (age at first calving, season) and (2) genetic variance affecting longevity in Afrikaner cattle using survival analysis and a Weibull model and (3) evaluate the effect of the Infusion Project on longevity utilizing a Cox model. For the first objective, age at first calving impacted longevity as younger age at first calving was associated with decreased longevity. Season of birth and year of birth also impacted …

Soil Responses To Eastern Redcedar (Juniperus Virginiana L.) Afforestation And Prescribed Fire In South-Central South Dakota, Robert Schaefer

Electronic Theses and Dissertations

Research was conducted in 2019 and 2020 on rangelands located in south-central South Dakota assessing a number of physical, chemical, and biological properties of mineral ustepts and ustents soils associated with eastern redcedar (ERC) (Juniperus virginiana) afforestation and prescribed fire. ERC afforestation appeared to be associated with significantly higher field-condition soil aggregate stability, cation exchange capacity (CEC), soil pH, and fungi:bacteria (F:B) as well as significantly lower soil moisture, nitrate-N, phosphorus, bacteria biomass, and Gram-positive:Gram-negative (GP:GN) bacteria compared to native grassland conditions, while other mineral soil properties appeared relatively unaffected. Compared to soil conditions under dense, living ERC canopies, prescribed …

Increasing Retention Of Women In Hunting And Fishing, Shelby Isensee

Electronic Theses and Dissertations

Despite national declines in hunting and fishing, women are making inroads in historically male-dominated sports. To further encourage women’s participation, states established programs to recruit, retain, and reactivate [R3] hunters and anglers. Women are participating in these programs and other recreational groups to access opportunities to learn skills and grow their networks. Yet, very little is known about what programs are offered for women, what aspects of programs are most effective to support women’s retention in these activities, and what women’s hunting and fishing groups are available across the landscape. To address these questions, I collected qualitative data from participant …

Respiratory Disease In Bighorn Sheep: A Varied Investigation Of Immunization, Transmission, And Detection, Katelin Frerichs

Electronic Theses and Dissertations

Respiratory disease has historically been recognized as a limiting factor to wild bighorn sheep (Ovis canadensis) herds throughout North America with epizootics resulting in large-scale die offs and reductions in recruitment. The primary etiologic agent associated with pneumonia outbreaks in bighorn sheep is Mycoplasma ovipneumoniae. This bacterial pathogen is frequently carried asymptomatically by domestic sheep (Ovis aries) and goats (Capra hircus); however, when these domestic hosts come in contact with and spread this pathogen to bighorns, the disease can cause epizootics and large-scale mortality. Domestic sheep strains are more commonly detected in bighorn sheep than domestic goat strains, and previous …

Comparative Lineament And Geomorphic Analysis Of Chaotic Terrains And Noctis Labyrinthus, Mars, Sarah A. Walton

Electronic Theses and Dissertations

Noctis Labyrinthus (NL) is an extensional trough network connecting the Tharsis rise and Valles Marineris on Mars. Chaotic terrains are a group of polygonally-fractured surface features commonly associated with subsidence due to rapid fluid loss within the subsurface. Polygonal surface patterns are seen at both sites, where geometric topographic highs are bounded by low troughs. Lineaments, topography, and geomorphology of NL and chaotic terrains were analyzed to determine tectonics and fluid influence in the formation and evolution of both sites. NL shows preferential fracture patterns associated with regional extension. Lineaments within chaotic terrains do not show cumulative preferential trends but …

Understanding Unacceptable Graduation Outcomes For Historically Excluded Trio Student Support Services Students, Erica Willis

Electronic Theses and Dissertations

The primary purpose of this mixed-methods study is to define the problem and to understand the system that has been leading to unacceptably low graduation outcomes for historically excluded Trio Student Support Services (Trio SSS) students at Mid-Atlantic University (MAU), a pseudonym. To achieve the primary purpose extant documents and institutional data that can shed light on system processes and institutional conditions that perpetuate disparities in graduation outcomes, particularly for historically excluded racial groups that exist at the intersection of first-generation status and/or low socioeconomic status, will be analyzed. The secondary purpose of this study is to identify potential change …

The Contribution Of Principlism To Foster Ethical And Clinical Reciprocity In Resolving Healthcare Dilemmas, Dominic Glorioso

Electronic Theses and Dissertations

Principlism is an ethical method that uses an analytical framework based on a set of principles that can function as guidelines for healthcare professionals. The term was made

famous by the work of two bioethicists, Tom L. Beauchamp and James F. Childress. Their book, Principles of Biomedical Ethics and its multiple editions described a set of norms that are basic

for biomedical ethics. The first edition of their book was published in 1979, and the ninth edition in 2019. Its persistence and durability speak for themselves. In addition, their writings made

famous the four bioethical principles of respect for Autonomy, …

Interactive Effects Of Sublethal Concentrations Of Fracking Biocides And Abandoned Mine Drainage On Amphipod Behavior, Kelly Lenhart

Electronic Theses and Dissertations

This thesis examined the sublethal effects of three pollutants, namely glutaraldehyde, 4,4-dimethyloxazolidine (DMO), and abandoned mine drainage (AMD), on amphipods. The primary objective was to investigate their combined effects on amphipods. The three pollutants, despite having the potential to combine in the environment, have not been studied to determine their potential for detrimental interactive effects which could result in unexpected environmental damage.

The research employed a series of experimental setups involving controlled exposure of amphipods to varying, putatively sublethal, concentrations of the chemicals of interest. Subsequently, effects were assessed via both behavioral and feeding assessments. To facilitate this analysis, novel …

Understanding The Psychological Significance Of Astrology In Millennial Women's Lives, Rachel June Floyd

Electronic Theses and Dissertations

In North America, astrology has been experiencing a resurgence in popularity. This is immediately remarkable given that the United States and Canada are industrialized, modern societies where astrology is widely lamented as a pseudoscience. This dissertation presents a phenomenological exploration of the underlying reasons for this cultural trend, particularly among the demographic that uses it most: millennial women. Existing psychological literature on astrology is primarily dominated by correlational studies or historical analyses and lacks the depth and richness of direct experiences of individuals engaging with this phenomenon. This study sought to address this gap within psychological literature specifically, by conducting …

Quantifying Current Soil Brine Contamination Within The Smackover Oil Field In Arkansas Using Multispectral Digital Imagery, Victoria Williams

Electronic Theses and Dissertations

A remote sensing study was performed to quantify current soil brine contamination across the historic Smackover Oil Field in south-central Arkansas, United States. The oil field was established in 1922 and was not subject to the future waste regulations created by the Arkansas Oil and Gas Commission. Brine is a waste product of oil manufacturing which contains water with high salt levels. The storage and transport of brine in the oil field created landscape scarring across the study area.

Landsat 9 multispectral digital imagery was utilized to create supervised classification maps based on earthen pits and creek scarring across the …

Synergistic Strategies In Sinter-Based Material Extrusion (Mex) 3d Printing Of Copper: Process Development, Product Design, Predictive Maps And Models., Kameswara Pavan Kumar Ajjarapu

Electronic Theses and Dissertations

3D printing pure copper with high electrical conductivity and exceptional density has long been challenging. While laser-based additive manufacturing technologies suffered due to copper's highly reflective nature towards laser beams, parts printed via binder-assisted technologies failed to reach over 90% IACS (International Annealed Copper Standard), electrical conductivity. Although promising techniques such as binder jetting, filament, and pellet-based 3D printing that can print copper exist, they however still face difficulties in achieving both high sintered densities and electrical conductivity values. This is due to a lack of comprehensive understanding of property evolution from green to sintered states and the strategies that …

Educator Perceptions Of The Care And Instruction Of Trauma Exposed Students In A Small, Urban, Christian School., Amanda L. Petters

Electronic Theses and Dissertations

Students of color in low socio-economic, high crime urban areas are exposed to a higher level of trauma than their White contemporaries. The trauma that they bring into school with them create challenges for their teachers working to eliminate barrier to students’ education. Widespread efforts have been attempted to thwart the social injustices that many students of color experience in schools including disproportionality around implementation of school rules and the equitable access to curriculum. I used Critical Race Theory to frame my study around students of color in urban areas experiencing disproportionate levels of trauma, and their teachers’ level of …

Quantification Of Tumor Biophysical Heterogeneity Through Mechanical And Ultrastructural Analysis., Bradley James Mahaffey

Electronic Theses and Dissertations

Glioblastoma (GBM) is a highly invasive, aggressive brain cancer that carries a median survival of 15 months. This poor prognosis is due, in part, to its resistance to standard therapeutic intervention. Recent studies have demonstrated that tumor heterogeneity plays a critical role in facilitation therapy resistance by mediating tumor adaptation through microenvironmental cues. Efforts to describe these microenvironmental differences may aid in the development of strategies to combat resistance. GBM can be separated into two distinct regions – a core and a rim, which are thought to drive specific aspects of tumor evolution. The core is proliferative as evidenced by …

Perovskite Oxide Derivatives For Enhanced Electrochemical Water Splitting And Pseudocapacitor Applications., Md. Sofiul Alom

Electronic Theses and Dissertations

The global energy landscape is at a crossroads, marked by surging demand, finite fossil fuel reserves, and escalating environmental concerns stemming from carbon emissions. To address these challenges and transition towards a sustainable energy future, this dissertation embarks on a multidisciplinary exploration of perovskite oxides and their derivatives as catalysts and materials for advanced electrochemical water splitting and pseudocapacitive energy storage. In the quest for efficient water splitting catalysts, a series of quasi-2D oxides, SrLaAl_1/2M_1/2O₄ (M = Mn, Fe, Co), was synthesized and systematically studied where the B-site comprised of both transition metals and main …

Scalable Solution Processing Of Niox Nanoparticles., Peter James Armstrong

Electronic Theses and Dissertations

Perovskite solar cells (PSCs) are a promising alternative to silicon-based photovoltaics. However, PSCs face several challenges due to shortcomings in their stability, module efficiency, and scaled production. Although PSCs is still a young field of research, significant attention has been given to demonstrating power conversion efficiencies that are on par with traditional silicon. With that target reached, converting the laboratory demonstration into practical materials to increase access and abundance of solar energy are among the next large targets for the field. This comes with material challenges for perovskite and their companion charge transport layers (CTLs). Among the charge transport materials …

Effects Of A Protection Zone In A Reaction-Diffusion Model With Strong Allee Effect., Isaac Johnson

Electronic Theses and Dissertations

A protection zone model represents a patchy environment with positive growth over the protection zone and strong Allee effect growth outside the protection zone. Generally, these models are considered through the corresponding eigenvalue problem, but that has certain limitations. In this thesis, a general protection zone model is considered. This model makes no assumption on the direction of the traveling wave solution over the Strong Allee effect patch. We use phase portrait analysis of this protection zone model to draw conclusions about the existence of equilibrium solutions. We establish the existence of three types of equilibrium solutions and the necessary …

Bayesian Strategies For Propensity Score Estimation In Causal Inference., Uthpala I. Wanigasekara

Electronic Theses and Dissertations

Causal inference is a method used in various fields to draw causal conclusions based on data. It involves using assumptions, study designs, and estimation strategies to minimize the impact of confounding variables. Propensity scores are used to estimate outcome effects, through matching methods, stratification, weighting methods, and the Covariate Balancing Propensity Score method. However, they can be sensitive to estimation techniques and can lead to unstable findings. Researchers have proposed integrating weighing with regression adjustment in parametric models to improve causal inference validity. The first project focuses on Bayesian joint and two-stage methods for propensity score analysis. Propensity score modeling …

The Self-Consistent Field Energy Landscape And Its Application To Describing Electron Correlation., Xinju (Spancer) Dong

Electronic Theses and Dissertations

Global elucidation of SCF (self-consistent-field) solutions is an extension of global optimization in which the goal is the identification of all solutions, which can be defined as a NP (nonpolynomial)-hard problem. The value of identifying multiple SCF solutions is to use as reference wavefunctions, such as NOCI (nonorthogonal configuration interactions), NOMCSCF (nonorthogonal multiconfigurational SCF), etc. However, the high-dimensional space over which to search and the relatively high cost of local optimization in Hartree-Fock (HF) models cause difficulty in efficiently searching over the full SCF space. In order to address the technical issues of high-dimensionality and nonlinearity, a Lie algebraic description …

Adaptive Personalized Drug Delivery Method For Warfarin And Anemia Management: Modeling And Control., Affan Affan

Electronic Theses and Dissertations

Personalized precision medicine aims to develop the appropriate treatments for suitable patients at the right time to obtain optimal results. Personalized medicine is challenging due to inter- and intra-patient variability, narrow therapeutic window, the effect of other medications, comorbidity (more than one disease at a time), nonlinear patient dynamics, and time-varying patient dose response characteristics which include bleeding (internal and external). This research aims to develop a framework for an adaptive personalized modeling and control method with minimum clinical patient specific dose response data for optimal drug dosing. The proposed methodology is applied to anemia and warfarin management. It is …

Causal Inference For The Effect Of Continuous Treatment On Time-To-Event Outcomes And Mediation Analysis On Health Disparities In Observational Studies., Triparna Poddar

Electronic Theses and Dissertations

The dissertation comprises two projects related to causal inference based on observational data. In healthcare research, where abundant observational data such as claims data and electronic records are available, researchers often aim to study the treatment effect and the pathway of that effect. However, estimating treatment effects in observational data presents challenges due to confounding factors. The first project focuses on estimating continuous treatment effects for survival outcomes, while the second concentrates on mediation analysis, allowing the exploration of the pathway of the causal effect. Both projects involve addressing confounding variables. In the first project, I investigate estimation of the …

Isotopic Ecology Of Bison And Bootherium At Big Bone Lick, Kentucky, Frances Stephenson

Electronic Theses and Dissertations

Big Bone Lick (BBL) is a late Pleistocene and Holocene fossil locality in the Ohio River valley of Kentucky. This study utilized stable isotopes (δ¹³C, δ¹⁸O, and ⁸⁷Sr/⁸⁶Sr) in tooth enamel to reconstruct mobility and diet in Bison, as well as diet in Bootherium bombifrons. Isotopic results from seven Bison and two B. bombifrons are reported. Results suggest Pleistocene Bison and Bootherium occupied different dietary niches. Although both had C3-dominated diets, Bison occupied more open environments than B. bombifrons. Two bison from the late Holocene deposit had diets that consisted …

Perceptions Of Educators On Motivational Strategies Influencing Middle School Students In Mathematics Courses, Amy Rigsby

Electronic Theses and Dissertations

This qualitative study examined educators' perceptions of motivational strategies influencing and motivating middle school students to comprehend and perform in mathematics courses. This study used interview data from 15 participants with 2 to 30 years of teaching experience. Educators may utilize this information in multiple settings within the classroom to influence and motivate students in mathematics courses.

Data collection strategies included one-on-one semi-structured middle school educator interviews. Analysis of data occurred in three phases: (a) categorization of data under the five organizational factors, (b) building the explanation in narrative form, and (c) re-examination of the data. The analysis of the …

Computational Investigations Of Bond Breaking Processes Using Dft And Td-Dft Approaches., Saurav Parmar

Electronic Theses and Dissertations

The efficient application of DFT and TD-DFT has been harnessed to study bond-breaking processes in some molecules which play a prominent role in enzymatic reactions. The first application includes Radical S-adenosyl methionine (SAM) enzymes which are fundamentally important sources of organic radicals to initiate diverse radical reactions. Recently a bio-organometallic intermediate (Ω) that contains an Fe‒C bond has been characterized and shown to be a common feature of radical SAM enzymes. The strength of Fe‒C bond in Ω has been computed using broken-symmetry density functional theory (BS‒DFT). Additionally, Fe‒C bond dissociation energy (BDE) in Ω has been compared to that …

Building Efficacy In Special Educators: An Examination Of Basic Readiness Factors, Clarice Wright Edwards

Electronic Theses and Dissertations

This phenomenological study examined the perceptions of self-efficacy of elementary special education teachers (SETs) providing services for students with disabilities (SWD) in the general education classroom setting. Additionally, this study explored the effect of job-embedded supports and the skill sets deemed essential to meet the needs of SWDs. Understanding methods that can enhance the skill sets and pedagogical knowledge of SETs beyond teacher preparation can provide schools and school districts with opportunities to build highly efficacious teachers and improve student outcomes. Participants were asked about the perceived impact of teacher preparation programs on the self-efficacy of practicing SETs and about …

Publication Of Undergraduate Experiments, Development Of Additional X-Ray Crystallography Experiments, And Proof-Of-Concept Cyclopropanation Reactions, Alain Beauparlant

Electronic Theses and Dissertations

Single crystal X-ray crystallography instructional materials were developed using a variety of compounds including sugar, Epsom salt, pyrite, copper(II) acetate, and rhodium(II) acetate. Rhodium(II) acetate was reacted with a variety of functionalized benzonitriles, and when crystals were obtained, characterized using single crystal X-ray crystallography. Rhodium(II) acetate with adducts of 4-nitrobenzonitrile and 4-(dimethylamino)benzonitrile were also characterized using proton NMR spectroscopy and Fourier Transform Infrared Spectroscopy. Rhodium(II) acetate with adducts of 4-(dimethylamino)benzonitrile was used as a catalyst in a proof-ofconcept reaction to determine if it acts as a catalyst in cyclopropanation reactions. Further, the new rhodium(II) acetate dinitrile compounds were investigated to …

Synthesis Of Bacterial Glycerophospholipids For Biomembrane Model Studies: A Means To Advanced Biofuels, Felix Adulley

Electronic Theses and Dissertations

To reduce reliance on fossil fuels, sustainable biofuels are being pursued, especially advanced biofuels like 1-butanol that have higher energy content and greater compatibility with existing infrastructure than ethanol. A persistent challenge is the yield-limiting toxicity of biofuels and process solvents, such as tetrahydrofuran, to the microbes that ferment biomass into biofuel. The cell membrane is a focal point of toxicity, and understanding how it interacts with fuels and solvents is key to improving yield. Phospholipid bilayers are the core of biomembranes, and model biomembranes of defined composition provide the ideal platform for biophysical studies. To this end, glycerophospholipids characteristic …

Electrodeposition Studies Of Gold Nanoparticles And Alginate Hydrogel Films., Harikrishnan Nambiathan Nambiar

Electronic Theses and Dissertations

This dissertation investigates the electrochemical deposition (ECD) and electrophoretic deposition (EPD) processes involving citrate (cit)-stabilized Au nanoparticles (NPs) and calcium alginate (Ca-Alg-Au NP) hydrogel films. The first part of the dissertation investigates the influence of NP size, surface area (SA) coverage, and ligand stabilizers on the electrochemical growth of Au on Au NPs, aiming to enhance our understanding of the growth process during the nucleation and growth of metal NPs. The growth kinetics depend on Au NP size (4 nm > 15 nm > 50 nm) for a constant SA coverage, as determined by the overpotentials for ECD. The growth rate increases …

Implementation Of Hierarchical And K-Means Clustering Techniques On The Trend And Seasonality Components Of Temperature Profile Data, Emmanuel Ogedegbe

Electronic Theses and Dissertations

In this study, time series decomposition techniques are used in conjunction with Kmeans clustering and Hierarchical clustering, two well-known clustering algorithms, to climate data. Their implementation and comparisons are then examined. The main objective is to identify similar climate trends and group geographical areas with similar environmental conditions. Climate data from specific places are collected and analyzed as part of the project. The time series is then split into trend, seasonality, and residual components. In order to categorize growing regions according to their climatic inclinations, the deconstructed time series are then submitted to K-means clustering and Hierarchical clustering with dynamic …

Computational Quantum Chemistry Studies Of The Stabilities Of Radical Adducts Formed During The Oxidation Of Melatonin Derivatives, James Horne

Electronic Theses and Dissertations

Melatonin is a natural antioxidant that has been investigated for properties as a potential spin trap to identify short-lived free radicals. Computational quantum chemistry studies have been performed for the oxidation of melatonin to N¹-acetyl-N²-formyl-5-methoxykynuramine. This research focused on modification of melatonin into derivatives and analyzing the change in total molecular energy from melatonin to its oxidation product, as well as the corresponding derivatives. Each of the molecular geometries were optimized at the DFT/B3LYP/6-31G(d), DFT/B3LYP/cc-pVXZ (X = D, T), HF/6-31G(d), HF/cc-PVXZ (X = D, T), MP2/6-31G(d), and MP2/cc-PVXZ (X = D, T) levels of theory. …

Convolution And Autoencoders Applied To Nonlinear Differential Equations, Noah Borquaye

Electronic Theses and Dissertations

Autoencoders, a type of artificial neural network, have gained recognition by researchers in various fields, especially machine learning due to their vast applications in data representations from inputs. Recently researchers have explored the possibility to extend the application of autoencoders to solve nonlinear differential equations. Algorithms and methods employed in an autoencoder framework include sparse identification of nonlinear dynamics (SINDy), dynamic mode decomposition (DMD), Koopman operator theory and singular value decomposition (SVD). These approaches use matrix multiplication to represent linear transformation. However, machine learning algorithms often use convolution to represent linear transformations. In our work, we modify these approaches to …