Digital Commons Network^™

The Fate And Removal Of E. Coli Across Liquid And Sludge Treatment Stages In An Activated -Sludge Water Resource Recovery Facility, Shrawan Tandukar

Electronic Theses and Dissertations

This study evaluates the fate and removal efficiency of Escherichia coli (E. coli) across both liquid and sludge treatment processes at a full-scale activated sludge water resource recovery facility (WRRF) in Brookings, South Dakota. Understanding pathogen reduction within wastewater treatment systems is critical for protecting public health and ensuring regulatory compliance, particularly in facilities practicing water reuse and biosolids management. Liquid and sludge samples were collected from multiple treatment stages between January and July 2025 and analyzed using the IDEXX Colilert Quanti-Tray 2000 method. This study quantifies E. coli concentrations throughout the treatment train to assess removal performance and identify …

Production Of Fungal Biomass And Crude Chitin From Cheese Whey: Effects Of Whey Type And Lactose Hydrolysis On Aspergillus Niger And Trichoderma Reesei, Anye Catharine Nora Drum

Electronic Theses and Dissertations

Chitin is a biodegradable and biocompatible biopolymer with broad applications in the food, biomedical, pharmaceutical, and packaging industries. Conventional chitin production from crustacean shells is associated with seasonal availability, intensive chemical processing, and environmental concerns, creating interest in more sustainable alternatives. Filamentous fungi represent a promising source of chitin because of their rapid growth and ability to utilize low cost agro-industrial residues. This study evaluated the feasibility of producing fungal biomass and crude chitin from cheese whey through submerged fermentation while investigating the effects of whey type and enzymatic lactose hydrolysis on fungal growth, substrate utilization, and wastewater remediation. Aspergillus …

Effect Of Increasing Potency Of Steroidal Implants In Beef Steers At Weaning From Dry-Lot To Finish, Weston Joseph Peschel

Electronic Theses and Dissertations

The receiving phase is a stressful transition period in beef production. Newly weaned cattle are offered low-energy, high-forage diets promoting lean tissue and bone development prior to the finishing phase. Steroidal implants containing trenbolone acetate (TBA) and estradiol benzoate (EB) enhance lean gain. Aggressive early implant exposure has been shown to negatively impact intramuscular fat deposition. This two-part study evaluated the initial and carryover effects of increasing doses of combined TBA and EB weaning implants on growth performance, serum metabolites, and carcass traits. In Exp. 1, newly weaned Charolais × Red Angus crossbred beef steers [n = 240 initially; body …

Effect Of Corn Processing Methods On Growth Performance, Carcass Characteristics, And Gastrointestinal Health In Ruminants Fed Finishing Diets, Reanna Rae Byrnes-Schoen

Electronic Theses and Dissertations

The objective of this work was to evaluate different feed processing techniques and their impacts on growth performance, carcass traits, and gastrointestinal health in ruminant animals fed in confinement during the finishing phase. Two studies were conducted. The first study evaluated the effect of kernel processing high moisture ear corn (HMEC) on growth performance and carcass characteristics of finishing beef steers. The second study used feeder lambs to evaluate the effect of steam-flaking corn in a finishing diet on growth performance, carcass characteristics, and gastrointestinal tract (GIT) health. The results from the first study using steers demonstrated that feeding kernel …

Strip-Till Adoption For Soybean Production In Eastern South Dakota: Plant Development, Seed Quality, And Economic Analysis, Nicolas Passone

Electronic Theses and Dissertations

Soybean production in eastern South Dakota faces a persistent challenge: cool, wet spring conditions combined with heavy soils limit the adoption of conservation tillage despite its soil health and environmental benefits. Strip-tillage has been proposed as a middle-ground practice capable of providing conservation benefits while maintaining the seedbed quality advantages of conventional tillage. However, its performance in soybean production in South Dakota had not been evaluated prior to this work. This research examined the effects of tillage systems and fertilizer placement-timing, fertilizer rate, and seeding rate on soybean plant development, nutrient uptake, seed yield, chemical composition, and partial net economic …

Impacts Of Management Practices And Soil Properties On Free-Living Nitrogen Fixation In Eastern South Dakota, Laura Galvan Nuevo

Electronic Theses and Dissertations

Free-living nitrogen (N) fixation (FLNF) may represent a sustainable pathway to supplement crop N demand in agroecosystems, yet edaphic and management factors regulating this process under field conditions remain poorly understood in the Northern Great Plains. Using 15N2 direct method to quantify potential FLNF (pFLNF) and baseline FLNF (bFLNF), this thesis investigates how crop rotations (2-, 3-, and 4-year systems), tillage management (conventional vs. no-till), cover cropping, and soil properties affect the potential of free-living diazotrophs to supply N via FLNF in a long-term no-till corn-based system in Southeastern South Dakota. A two-year field study evaluated pFLNF across four growing …

Primary Avian Tracheal Cell Models For The Isolation Of Emerging Avian Metapneumovirus Strains, Tricia Serrao

Electronic Theses and Dissertations

The emergence of avian metapneumovirus (aMPV) subgroups A and B in the United States poultry industry has created an urgent need for standardized, host-specific diagnostic platforms. Historically, reliance on continuous, multi-species cell lines has limited the primary isolation of field strains and introduced potential adaptation artifacts. To address these challenges, this research first established and characterized a reproducible primary cell culture system derived from the tracheal tissues of 1-day-old turkey poults. This system was maintained in an optimized DMEM/F-12 formulation supplemented with 5% FBS, EGF, and ITS, with early-passage cultures achieving 90% confluence within 24 to 48 hours. Morphological and …

Impact Of Water Level Fluctuations On Fish Populations In Eastern South Dakota Rivers, Benjamin Schall

Electronic Theses and Dissertations

Riverine systems are highly dynamic, and changes in flow conditions can impact the population dynamics of fishes. Increased flows from historical averages in eastern South Dakota rivers have likely impacted fish populations. The goals of this study were to 1) better understand the changes in resource use by Blue Suckers Cycleptus elongatus through retrospective eye lens stable isotope analysis, 2) determine the effects of record flooding in the James River on complex woody habitat and Flathead Catfish Pylodictis olivaris population structure, and 3) assess the influence of river discharge and temperature on Channel Catfish Ictalurus punctatus and Flathead Catfish condition …

Evaluating The Potential Of Genomic Selection For Grain Yield And Yield Component Traits In South Dakota Winter Wheat, Dante Koupal

Electronic Theses and Dissertations

Wheat (Triticum aestivum L.) is a major cereal crop worldwide, but recent gains in grain yield (GY) have not kept pace with projected demand. GY is a highly quantitative trait with low heritability that requires multi-year, multi-location phenotyping, limiting selection efficiency. Targeting higher heritability yield component traits, such as kernel size and weight, and incorporating them into the genomic selection (GS) pipeline has the potential to accelerate genetic gain for GY. The objectives of this study were to (i) understand the relationship between GY and the kernel-size traits, including thousand kernel weight (TKW), kernel length (KL), kernel width (KW), and …

Butting Heads With Respiratory Disease: Post-Epizootic Demography And Movement-Driven Spillover Risk In A Badland’S Bighorn Sheep (Ovis Canadensis) Meta-Population, Sean P. Ryder

Electronic Theses and Dissertations

Respiratory disease caused by Mycoplasma ovipneumoniae is among the most significant threats to bighorn sheep (Ovis canadensis) conservation in North America. In July 2021, contact between bighorn sheep rams and domestic sheep north of Badlands National Park (BADL), South Dakota, USA introduced M. ovipneumoniae into the Badlands bighorn sheep meta-population, triggering an epizootic that reduced the population by approximately 80%. I evaluated the post-outbreak status of this population through two complementary studies conducted from 2023 to 2025. In Chapter 1, I quantified disease prevalence, adult survival, lamb recruitment, and population growth rate (λ) using serial quantitative polymerase chain reaction (qPCR) …

Investigation Of Perennial Clover Living Mulch And Reduced Tillage Effects On Weed Suppression, Crop Metrics, And Yield Of Organic Cabbage And Sweet Corn In The Northern Great Plains, Kristina Harms

Electronic Theses and Dissertations

Vegetable farmers often face weed management and soil health challenges, such as nitrate leaching, soil compaction, and top-soil loss. Sustainable agriculture is a forefront of innovation compared to conventional agriculture. Living mulches, non-cash crops grown alongside cash crops, have demonstrated weed suppression and impact on the promotion of sustainable agriculture. Yet studies have not evaluated established living mulch systems on cash crop quality and yield. This study conducted in 2023, 2024, and 2025 at SDSU Southeast Research Farm, Beresford, SD, USA evaluates the impact of established ‘Dynamite’ red clover (Trifolium pratense), ‘Domino’ white clover (T. repens), and ‘Aberlasting’ white × …

Production, Characterization, And Diagnostic Application Of Monoclonal Antibodies Against The N-Protein Of Avian Metapneumovirus Subgroup B, Ravi Gupta

Electronic Theses and Dissertations

Avian metapneumovirus (aMPV) is a respiratory pathogen that causes Turkey Rhinotracheitis (TRT) in turkeys and Swollen Head Syndrome (SHS) in chickens. The infection leads to facial swelling, nasal discharge, reduced egg production, and poor growth. This virus is classified into four subgroups: aMPV-A, B, C, and D, with two other novel subgroups, in which aMPV-A, B, and C are most prevalent in the commercial flocks. In early 2024, aMPV-A and B outbreaks have been reported in the US, resulting in severe economic losses. An economic assessment estimates around $112 million in losses in Minnesota and up to $434 million in …

Evaluating Supplementation Strategies Using Precision Livestock Technologies And Energy Based Models In Developing Beef Heifers Grazing Dormant Rangeland, Kali-Jo Bentz

Electronic Theses and Dissertations

Replacement beef heifer development in extensive grazing systems is challenged by variation in forage quality, supplement intake, and animal behavior, all of which influence the ability to achieve targeted growth prior to breeding. Precision livestock technologies (PLT) enable continuous monitoring of individual animal performance, while energy-based nutritional models support individualized supplementation. However, their application under extensive grazing conditions remains poorly understood. Therefore, the objectives of this thesis were to (1) evaluate heifer utilization of multiple precision livestock technologies and their relationship with animal performance and (2) evaluate the accuracy of an individualized energy-based supplementation model by comparing predicted supplement allotments …

Demographic Impact And Diagnostic Evaluation Of Mycoplasma Ovipneumoniae In Bighorn Sheep Of The Pine Ridge Badlands, Jeffrey Tillery

Electronic Theses and Dissertations

Mycoplasma ovipneumoniae (M. ovi) decimates bighorn sheep (Ovis canadensis) populations through acute die-offs followed by years or decades of failed lamb recruitment. Test-and-remove management has emerged as the primary intervention to restore population growth, and this thesis quantifies the demographic costs of endemic M. ovi infection and evaluates the diagnostic tools upon which this strategy depends. I quantified vital rates across five bighorn sheep subherds (four infected, one uninfected) on the Pine Ridge Reservation (2023–2025), supplemented by pre-outbreak data (2017–2018) from the North Unit of Badlands National Park. Infected subherds declined (λ = 0.965, 95% CrI: 0.813–1.039) while the uninfected …

Plant-Insect Interactions In Great Plains Restoration And Invasion Ecology, Joseph H. Cammarano

Electronic Theses and Dissertations

Prairie ecosystem loss and invasive plant species are major ecological problems in the Great Plains. Plant-insect interactions have important consequences for both the restoration of prairie ecosystems and management of invasive plant species. Pollinating insects are vital to the sustainability of prairie ecosystems, and herbivorous insects can provide biological control of invasive plant species. Understanding how restoration strategies may influence potential pollinator communities can have important consequences for restoration sustainability and success and understanding how biological control strategies may help manage invasive plant populations can also help land managers reach restoration and conservation goals. In Ch. 2, I sought to …

The Influence Of Controlled Intake And Anabolic Implant Timing On Growth Performance And Carcass Traits In Feedlot Ruminants, Justin J. Delver

Electronic Theses and Dissertations

The objective of this dissertation was to evaluate how previous plane of nutrition and anabolic implant timing interact to influence growth performance, composition of growth, and the carcass characteristics in ruminants. Three experiments were conducted using cattle and sheep models to determine the metabolic adaptations driving compensatory growth. In experiment 1, yearling beef steers (n = 192) were fed ad libitum for 141 days (ADLIB) or restricted to 92% of ad libitum intake for 56 (RES56) or 86 (RES86) days followed by realimentation. Cumulative dry matter intake (DMI) was reduced in both restricted groups (P = 0.002) with no difference …

Accessing Campus Mental Health Services In A Nigerian Southwestern University: Barriers To Academic Success, Caroline Dada

Electronic Theses and Dissertations

Mental health disorders are a significant health concern among higher education institutions in sub-Saharan Africa, including Nigeria. A substantial treatment gap exists in the Nigerian healthcare system, and this gap is further worsened by cultural and religious barriers, which reinforce stigma that discourages students from seeking professional help. This qualitative narrative inquiry explored the barriers students encountered when accessing mental health services at a university in Southwestern Nigeria, to increase service access. Qualitative semistructured interviews were conducted with seven professional mental health providers at a university counseling center between March and April 2025. Inductive thematic analysis was used to identify …

An Ancient And Future Model Of Ecclesial Ministry: Exploring Insights From African Ecclesiology For A Revitalized Understanding Of The Catechist In The Amecea Region, Fortunatus Mugisha

Electronic Theses and Dissertations

The ministry of the catechist has historically been an enduring and transformative ministry in the life of the Church in Africa, particularly in the AMECEA region. Within the AMECEA region (Association of Member Episcopal Conferences in Eastern Africa), catechists have ministered not merely as transmitters of the faith but as the “unsung heroes and heroines” and vital agents of evangelization, pastoral care, and community leadership serving as the local face of the Church. This dissertation, relying on the insights from African ecclesiologies, proposes a renewed theological and pastoral understanding of the catechist as an ancient and future model of ecclesial …

Hoarding And The Hoarded Home: A Phenomenological And Psychoanalytic Study, Brianna Stich

Electronic Theses and Dissertations

While research on hoarding tends to isolate hoarders from the homes they hoard and in which they live, the hoard and the hoarder share a life in the home. This study explores how hoarders live with and live through their hoard at home. It combines psychoanalysis and phenomenology within a unique methodological framework to provide a hermeneutic reading of the psychological significances of the hoarded home. In this study, the contemporary conceptualization of hoarding is historically situated and critiqued from a phenomenological perspective, and the view that hoarding is a single, behaviorally-defined syndrome that is explainable by a cognitive-behavioral model …

Behavior Analytic Food Reinforcement Use And Guidelines In Interventions For Children With Autism, Christopher Rogers

Electronic Theses and Dissertations

Reinforcers create opportunities to increase behaviors in applied behavioral analysis, with healthy and unhealthy foods offering high reinforcing value. The use of food raises ethical and health concerns, so researchers and behavior analysts often avoid food reinforcement altogether. Kronfli et al. (2024) indicate healthy food alternatives bring about similar rates of responding as snack foods, potentially reducing ethical and health concerns. This research presents the question: To what degree are food reinforcers used in behavioral interventions for children with autism spectrum disorder? This review analyzes behavioral research articles containing the words “food,” “edible,” “autism,” and “children” in the context of …

Profiles Of Adults With Attention-Deficit/Hyperactivity Disorder (Adhd) Using The Personality Assessment Inventory (Pai), Tailyn L. Gillette

Electronic Theses and Dissertations

Attention-Deficit/Hyperactivity Disorder (ADHD) is often diagnosed in childhood. However, the disorder can be more complex to diagnose in adulthood as several comorbid disorders may also impact attention. Many symptoms, often prevalent in childhood, taper off in adulthood, adding to the difficulty of differential diagnosis. Clinicians must decipher symptoms of ADHD from comorbid disorders during diagnostic procedures, which can be tedious. As the requests for adult ADHD diagnoses grow, the need for more efficient diagnostic procedures seems to be ever-present. The current research utilized an exploratory two-step cluster analysis to explore subgroups that resulted from archival data of adults with ADHD. …

Deep Learning For Underwater Manatee Counting And Tracking, Theodor Owchariw

Electronic Theses and Dissertations

The Florida manatee (Trichechus manatus latirostris), a threatened marine mammal often found in coastal waters, require accurate monitoring to inform conservation strategies. However, traditional counting methods are hindered by observer bias and surface distortions. Recent advances in artificial intelligence (AI) address these challenges using captured aerial footage of manatees, demonstrating the potential of artificial intelligence for automating manatee counting. Still, various challenges arise hindering accurate counts.

Building on these studies, this work advances artificial intelligence with underwater footage, instance segmentation, data augmentation, and pseudo-labeling to automate manatee counting in data-scarce environments. Three experiments were conducted using 10%, 60%, and 90% …

Molecular Dynamics Simulations Of Biologically Relevant Interfaces: From Tear Film Lipid Layers To Rna Adsorption On Silica Surfaces., Mahbuba Khanom

Electronic Theses and Dissertations

Molecular dynamics (MD) simulation is an important tool in biochemical sciences for studying complex molecular processes and interfacial interactions at the molecular level. Biological interfaces play key roles in processes such as ocular lubrication and biomolecular adsorption. This dissertation studies interfacial phenomena involving two distinct yet conceptually related systems: the tear film lipid layer (TFLL) at the air–water interface at the surface of the human eye, and RNA adsorption on silica surfaces. These studies provide insight into how interfacial composition, structure, and environmental conditions affect larger-scale behavior. Atomistic MD simulations were used to model the TFLL. The TFLL is essential …

Experiences Of Research Administrators With Faculty Researchers In Sponsored Project Compliance., Adrienne M. Lindsay

Electronic Theses and Dissertations

The purpose of this study was to examine how central office research administrators perceive and describe their professional interactions with faculty researchers, and how those relationships may impact compliance with sponsored project requirements in United States higher education institutions. Cohen et al.’s (1972) organized anarchy theory and Schein’s (2010) organizational culture theory provided a foundational context for understanding research systems within higher education institutions and the social environment in which research administrators navigate potentially contentious roles, both facilitating research and stewarding compliance for the institution and the sponsor. Findings emerged around specific challenges faced by research administrators, which included role …

Impacts Of Biology Modeling Pedagogy On Student Cogitive And Non-Cognitive Elements Of Learning., Jessie K. Newhouse

Electronic Theses and Dissertations

This dissertation employed a quasi-experimental design used to investigate the use of a modeling pedagogy in high school biology. Modeling is a key element of the Science and Engineering Practices of the Next Generation Science Standards. While research of Model Based Pedagogy (MBP) in physics and chemistry is well established, the influence on biology instruction remains less understood. This research examined how MBP affected both cognitive and non-cognitive components of student learning compared to traditional biology instruction. Existing data collected by Dr. Kathy Malone in collaboration with Ohio State University (2016) were analyzed to study the effectiveness of the MBP. …

Controlling Selectivity In Electrocatalytic Co2 Reduction With An External Magnetic Field., Nawaraj Karki

Electronic Theses and Dissertations

My dissertation describes how to alter the speciation and concentration of molecules at the electrode-electrolyte interface, and how those alterations affect reactivity and selectivity. This dissertation presents two distinct approaches to control the mass transport of neutral molecules such as carbon dioxide (CO₂) at the electrode-electrolyte interface by using an external magnetic field. The first finding demonstrates that magnetic fields indirectly affect the mass transport of target analytes such as CO₂ molecules by selectively interacting with charged species, such as hydroxide ions (OH^-). Such interaction induces magnetohydrodynamic (MHD) effects, which generate localized hydrodynamic flow and …

Integration And Modulation Of Visual Signals In Dorsal Thalamus., James Whitley

Electronic Theses and Dissertations

The visual thalamus is influenced by a diverse array of cortical and subcortical inputs that shape how information is transmitted to cortex. Using a variety of anatomical, optogenetic, and in vitro physiological techniques I investigated the differential impacts of modulation and integration of first and higher-order thalamic nuclei, while relying on influential concepts on the general organization of thalamic nuclei. In the first data chapter, I determined how GABAergic pretectum (PT) projections to the dorsal lateral geniculate nucleus (dLGN) and visual thalamic reticular nucleus (vTRN) can influence retinogeniculate signal transfer. We found that the PT provides over 75% of the …

The Role Of Fast-Food Consumption, Residential Fast-Food Exposures, And Urinary Essential Trace Heavy Metals In Colorectal Cancer (Crc) Outcomes., Jeevan Adhikari

Electronic Theses and Dissertations

Background: Colorectal cancer (CRC) is a public health concern. Within the United States (US), fast-food consumption and environmental exposure to heavy metals have increased. The impact of fast-food consumption frequency from fast-food restaurants, residential fast-food exposures, and urinary essential trace heavy metals in relation to CRC outcomes have not yet been rigorously evaluated in the US. Methods: Within the LEAPS-CRC study, we used geographic information systems (GIS) and logistic regression to study the association of fast-food consumption, residential proximity to a fast-food outlet, and urinary essential trace metals with CRC incidence. Additionally, within Kentucky Cancer Registry (KCR) CRC cases, the …

Genetic Identification Of A Rapidly-Adapting Low-Threshold Mechanoreceptor Innervating Fungiform Papillae., Thomas Alexander Myers Ii

Electronic Theses and Dissertations

Mechanosensory innervation of the oral cavity enables us to detect the texture and location of the foods we consume. Our goal was to find a genetic identifier for a mechanoreceptive subtype. Toward this goal, we examined neurons expressing the neurotrophin receptor TrkC, parvalbumin (Pvalb), and the glutamate transporter Vglut3. Because different papilla types contribute to food detection in different ways, we examined the innervation patterns of these neuron subtypes. We found that Pvalb+ and Vglut3+ neurons were fungiform papilla specific, where TrkC innervated both papilla types. We examined the anatomy of the three genetic populations, finding that the Pvalb+ neurons …

Characterizing Hexavalent Chromium Neurotoxicity Across Laboratory Models., Samuel Thomas Vielee

Electronic Theses and Dissertations

Hexavalent chromium [Cr(VI)] is a ubiquitous environmental pollutant and potent toxicant. Exposure to Cr(VI) in drinking water is primarily associated with cancers, inflammation, and hepatotoxicity; however, recent studies have identified Cr(VI) as a neurotoxicant in rodent and cell culture models. The literature suggest chromium accumulates in the brain, induces widespread neurodegeneration, and alters rodent behaviors. Despite these data, we lack a detailed and consistent assessments of Cr(VI) neurotoxicity across models, and interactions between aging and Cr(VI) neurotoxicity are not reported in the literature. In this dissertation, we characterize Cr(VI) neurotoxicity across 3 laboratory models: Sprague-Dawley rats, Caenorhabditis elegans, and …