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A Multi-Isotope Investigation Of Mammoth Diet, Habitat, And Movement Patterns In The Central Great Plains, U.S.A., Jacob Mccloskey

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

During the Last Glacial Maximum (LGM), the Great Plains in Nebraska consisted of wooded parklands and grasslands, whereas spruce (Picea) forests, parklands, and steppe grasslands dominated east of the Missouri River. I analyzed bulk carbon (δ¹³C), oxygen (δ¹⁸O), and strontium (⁸⁷Sr/⁸⁶Sr) isotopes from tooth enamel in isolated mammoth (Mammuthus) molars to compare diet and movement patterns in two late Pleistocene assemblages: one in Nebraska (n = 24), and one in western Iowa and Missouri (n = 17). Furthermore, I identified a morphometric subset of molars as …

Functional Genomics Of Phosphatidylcholine Biosynthesis In Saccharomyces Cerevisiae, Amanda Marie Maliva

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

Phosphatidylcholine (PtdCho) is a prominent structural building block of cell and organelle membranes in animal, plant, and fungal cells and some bacteria. Due to its abundant nature in the plasma membrane and intracellular organelle membranes in eukaryotes, the biosynthesis of PtdCho must remain regulated to preserve the correct membrane lipid composition. Dysregulations in PtdCho metabolism can lead to mitochondrial dysfunction, cell death, and the development of diseases including cancer, atherosclerosis, and hepatic diseases. Knowledge of PtdCho has remained limited to the genes involved in its three biosynthetic pathways (Kennedy (K), methylation (M), and acyltransferase (A)), despite the growing realization of …

B.R. Wells Arkansas Rice Research Studies 2024, J. Hardke, X. Sha, N. Bateman

Arkansas Agricultural Experiment Station Research Series

Research reports contained in the publication may represent preliminary or only a single year of results; therefore, these results should not be read as a basis for long-term recommendations.

Several research reports in this publication will appear in other University of Arkansas System Division of Agriculture’s Arkansas Agricultural Experiment Station publications. This duplication is the result of the overlap in research coverage between disciplines and our effort to inform Arkansas rice producers of all the research being conducted with funds from the rice check-off program. This publication also contains research funded by industry, federal, and state agencies.

Use of products …

Impact Of S-Phase Kinase Protien 2 Blockades On Hematopoetic Stem Cell Metabolism, Nicole Elmaraghy

Electronic Theses, Projects, and Dissertations

Hematopoietic stem and progenitor cells (HSPCs) quiescence is vital for the success of bone marrow transplantation, as it preserves long term self- renewal and prevents premature exhaustion (Takubo et al., 2013; Wilson et al., 2008). However, bone marrow transplant (BMT) failure remains a clinical challenge, often due to lack of long-term engraftment and insufficient stress reliance. Both of these characteristics are tightly linked to disrupted stem cell quiescence and metabolic imbalance (Anso et al., 2017; Vannini et al., 2016). One key player is S-phase kinase protein (SKP2), an E3 ubiquitin ligase that targets cell cycle inhibitors, like p27, for proteosome …

Microbial Guardians Of The Savannah: Unraveling The Gut Microbiome For African Carnivore Conservation, Laura E. Peirson

All NMU Master's Theses

Non-invasive fecal sampling is essential for wildlife gut microbiome (GMB) research, yet field conditions often limit preservation options. I compared gut bacterial communities in paired fecal samples preserved in stabilization tubes and air-dried in paper bags collected from anesthetized African lions (Panthera leo) and spotted hyenas (Crocuta crocuta) in Etosha National Park, Namibia. Additional opportunistic samples from carnivore kill sites were also analyzed. No significant differences in alpha or beta diversity were detected between preserved and dried samples, although bacterial beta diversity differed between preserved and opportunistic samples (PERMANOVA). Core bacterial communities remained consistent across sample …

Crevice Corrosion Mechanisms Of Cocrmo Alloys In Orthopedic Implants: Retrieval Analysis, Nano-Tribocorrosion And Cellular Responses, Hwaran Lee

All Dissertations

Mechanically assisted corrosion and non-mechanically (chemically) driven corrosion in modular junctions of orthopedic implants using cobalt-chromium-molybdenum (CoCrMo) alloys remain clinical concerns and may contribute to implant failure. The underlying corrosion mechanisms are not yet fully understood, leaving a critical research gap. We hypothesized that corrosion in modular junctions may be driven by aggressive local environments, including fretting, metal ion release (cobalt ion, Co²⁺), low pH and reactive oxygen species (ROS). This dissertation aims to (1) analyze corrosion modes and potential causes in modular junctions; (2) identify chemically driven corrosion modes on CoCrMo alloys using simulated inflammatory modular taper …

Factors Underlying A Latitudinal Gradient In The S/G Lignin Monomer Ratio In Natural Poplar Variants, Jin Zhang, Pradeep Kumar Prabhakar, Yen On Chan, Rachel A. Weber, Mengjun Shu, Ganesh Panzade, Connor J. Cooper, Russell B. Davidson, Jin-Gui Chen, Sara S. Jawdy, Jerry M. Parks, Breeanna R. Urbanowicz, Gerald A. Tuskan, Trupti Joshi, Richard A. Dixon, Wellington Muchero, Jaime Barros

Biomedical Sciences

The chemical composition of wood plays a pivotal role in the adaptability and structural integrity of trees. However, few studies have investigated the environmental factors that determine lignin composition and its biological significance in plants. Here, we examined the lignin syringyl-to-guaiacyl (S/G) ratio in members of a Populus trichocarpa population sourced from their native habitat and conducted a genome wide association study to identify genes linked to lignin formation. Our results revealed many significant associations, suggesting that lignin biosynthesis is a complex polygenic trait. Additionally, we found an increase in the S/G ratio from northern to southern geographic origin of …

The Market For Local Beef And Local Beef Processing Investment In Arkansas., Rebekah O'Neal

Graduate Theses and Dissertations

The COVID-19 pandemic exposed vulnerabilities in the U.S. food supply chain, particularly in the beef sector, where processing bottlenecks and labor shortages disrupted meat production and the market. In response, several policies were implemented to strengthen food system resilience, and significant funding was allocated to expand independent meat processing capacity nationwide. However, the long-term viability of expanding regional processing capacity remains uncertain, notably in Arkansas, a net exporter of live cattle. This study evaluates whether consumer demand supports the expansion of local beef processing in Arkansas. Using a dichotomous choice survey, we estimate market shares for beef labeled “Arkansas Grown” …

Factors Associated With Farm Service Agency Direct Farm Ownership Loan Delinquency, Mohammad Ismile Hossain

Graduate Theses and Dissertations

This thesis investigates the factors associated with loan defaults in the USDA's Direct Farm Ownership (FO) loan program, emphasizing factors that affect how long it takes to default. This study uses a Cox Proportional Hazards model on a dataset of more than 47,000 loan records originated during 2011-2020 to identify loan characteristics, financial factors, and geographic settings related to the likelihood and timing of delinquency, which is defined as being 90 days past due. Recent research has focused on differences in loan outcomes based on demographics. This study, on the other hand, focuses on loan size, interest rates and terms, …

Assessment Of A Muscadine Grape (Vitis Rotundifolia) Mapping Population For Tolerance To Pierce’S Disease Pathogen Xylella Fastidiosa And Resistance To Black Rot Disease Pathogen Guignardia Bidwellii, Anushka Tennakoon

Master's Theses

Pierce’s disease (PD) and black rot disease cause severe economic losses for grape production under humid and warm conditions. Identifying resistance genes is crucial for controlling these disease by developing resistant cultivars. Muscadine grape (Vitis rotundifolia) cultivar ‘Pam’ has been identified to possess a high level of resistance to diseases. To elucidate the genetic basis of the resistance to the causal pathogens Xylella fastidiosa and Guignardia bidwellii in this cultivar, parents and 141 F1 individuals developed from open pollinated ‘Pam’ were evaluated for two seasons under natural disease pressure. The mapping population was genotyped using genotyping-by-sequencing (GBS) and …

Analysis Of An Ethanol Sensitive Bmp-Nkx2.3-Fgf Signaling Pathway In Pouch Morphogenesis., Hieu Dai Le Vo

Electronic Theses and Dissertations

Craniofacial malformations lie at the heart of Fetal Alcohol Spectrum Disorders (FASD). While there is growing evidence for a genetic component to FASD, little is known of the cellular mechanisms underlying these ethanol-sensitive loci in facial development. Bone Morphogenetic Protein (Bmp) signaling pathway dependent pouch formation is a key mechanism in facial development. We have previously shown that multiple Bmp mutants are sensitized to ethanol-induced facial defects. However, ethanol does not directly impact Bmp signaling. This suggests that downstream effectors, like nkx2.3 and Fibroblast Growth Factor (Fgf) signaling, may mediate the impact of ethanol on Bmp mutants. Here, I …

Integrating Bulk And Single-Cell Transcriptomics To Investigate Intratumor Heterogeneity, Shuai Guo

Dissertations and Theses (Open Access)

Cancers are heterogeneous mixtures of tumor and surrounding cells, where each component comprises multiple distinct sub-types and/or states. Understanding the cell-type-specific contributions is critical for advancing cancer biology, yet high-throughput expression profiles from tumor tissues only represent combined signals from all diverse cellular sources. Bulk deconvolution with single-cell/nucleus (sc/sn) RNA-seq data has emerged as a powerful approach to dissect both cellular composition and cell-type-specific expression patterns, yet the technological discrepancy across sequencing platforms limits accuracy.

To systematically evaluate the impact of platform discrepancies on bulk deconvolution, we first generated a benchmark dataset of 24 healthy retinas with paired bulk and …

The Effect Of The Markle Mill Dam Removal On The Habitat And Riverine Food Web Of Otter Creek, Jenna Blanton

All-Inclusive List of Electronic Theses and Dissertations

Across the United States, dam removals are increasing in frequency. Despite this, the effects of dam removal on freshwater food webs are under-studied. Most existing studies investigate the impacts on fish assemblages, and very few investigate the impact on diatom, crayfish, and turtle communities. Furthermore, low-head dams are more abundant than large hydropower dams, yet the impacts of their removal are less studied than their larger counterparts. I used a Before After Control Impact (BACI) study design to survey populations of benthic diatoms, riffle-dwelling crayfish, and aquatic turtles. Species richness, species evenness, and Shannon Diversity Index values were used to …

Temperature Effects On Fruit Doubling And Bloom Prediction In Tart Cherry, Josette M. Moon

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry (Prunus cerasus) is a key horticultural crop in Utah. Extreme summer heat and cold weather in late spring are challenges to tart cherry production causing economic losses. These problematic weather conditions are influenced by the local landscape and are exacerbated by changing climate. This research explores (1) the impact of summer heat stress on fruit deformities, and (2) the accuracy of temperature-based predictions of spring bud development. High temperatures and water stress after harvest are known to cause a deformity known as twin or double fruits, resulting in unmarketable fruit. This disorder has been studied in …

The Effect Of An Acute Bout Of Rock Climbing On Cognitive Functioning And Cortisol Levels, Vanessa Steigauf

All NMU Master's Theses

Rock climbing is an understudied physical activity (PA) that demands active decision-making, integration of sensory and visual input, and continuous regulation of nervous system activity to produce complex motor outputs. The unique psychological demands of climbing warrant studying its effect on cognition and brain health. I recruited 26 generally healthy adults for a randomized-controlled study. Climbing experience, PA and perceived stress were self-reported. Each participant was randomly assigned to a climbing (10x2 minutes climb, moderate intensity) or control group (seated, watching climbing-related video). The primary outcomes, cognitive performance and salivary cortisol levels were assessed by the Stroop test. A linear …

Integrating Uas And Satellite Data To Improve Classification Of Plant Functional Types In A Forest Landscape, Sky Mae Gennette

Boise State University Theses and Dissertations

Remotely sensed land-use/land-cover (LULC) data products are an important tool for understanding landscape processes at all scales. The types of inference researchers can derive from remote sensing data depend on the quality and characterization of these LULC products. Currently, gaps in the detail of widely available vegetation cover products limit inference about processes at the level of plant functional type (PFT). Advanced remote sensing tools, machine learning, and data fusion can be employed to contribute novel methods to produce detailed, accurate vegetation cover products. Here, we combine high resolution Unoccupied Aerial Systems (UAS) multispectral, structural and textural data with large-scale …

Changes In Co-Activation And Lower Limb Stiffness During Prolonged Load Carriage, Matthew V. Robinett

Boise State University Theses and Dissertations

Introduction: Overuse musculoskeletal injuries are a common, costly challenge for the armed services. A stiffer lower limb during routine prolonged load carriage tasks may be necessary to attenuate elevated ground reaction forces but further increases musculoskeletal overuse injury risk. Quantifying leg and joint stiffness provides comprehensive and joint level insight into the attenuation of ground reaction forces, and subsequent injury risk. But, it is currently unknown how prolonged load carriage affects leg, knee and ankle stiffness, and knee and ankle muscular activation. Purpose: This study sought to quantify leg, knee, and ankle stiffness, and the activation and coordination of associated …

How Plant-Soil Feedbacks At Varying Levels Of Plant Species Diversity Influences The Reestablishment And Performance Of Native Sagebrush Steppe Species, Sierra Santosuosso

Boise State University Theses and Dissertations

Increased frequency of wildfire has become a significant problem in the sagebrush steppe, altering soil biogeochemical properties that promote the establishment of invasives at the expense of native species. To reduce annual grass invasion, restoration efforts often include seeding with non-native bunch grasses such as Agropyron cristatum (L.) Gaertn (crested wheatgrass [AGCR]) that outcompete cheatgrass; however, this strategy does not lead to the return of a native sagebrush steppe ecosystem. Restoring ecosystems to higher levels of native species diversity may reduce invasion and promote sustained success of restoration efforts since biodiversity can improve ecosystem functioning and promote resilience. In 2019 …

Exploring Variability Of The Cg18562578 Methylquant Assay For The Forensic Discrimination Of Monozygotic Twins, Sydney E. Arnold

Student Theses

Monozygotic (MZ) twins possess identical DNA sequences, posing a problem for forensic scientists, as they are incapable of distinguishing MZ twins from each other using traditional DNA identification methods. However, the epigenomes of MZ twins will differ and might be used for their forensic discrimination. Here, we explored the variability of an assay previously developed by our laboratory that showed high discrimination potential for MZ twins using buccal swab DNA, cg18562578 MethylQuant. We measured precision at each step: bisulfite conversion, nested PCR, and qPCR, reproducibility, and repeatability. DNA methylation ratios were compared between two analysts carrying each step using the …

Arginine Vasotocin And Corticosterone In Nesting And Non-Nesting Loggerhead Sea Turtles In X’Cacel-X’Cacelito Sanctuary, Krista Blair Reed

Theses and Dissertations

Sea turtles exhibit distinct behaviors before and after egg laying, however, not all individuals successfully oviposit. Some females display disruptions in their typical nesting behavior, returning to the water without laying eggs, which is referred to as a non-nesting emergence (NNE). NNEs can be due to external disturbances on the beach, but why they occur is often unclear. Arginine vasotocin (AVT) is a neuropeptide involved in various physiological processes, including stimulating smooth muscle contraction of the oviduct to facilitate egg deposition in nesting sea turtles. On the other hand, corticosterone is the primary stress hormone in sea turtles and is …

Exploring Transcriptional Stress Responses In Sorghum And Evolutionary Insights Into Yth Domain Proteins Across Plants, Shikha Bharti

Theses and Dissertations

Understanding how plants respond to abiotic stress is crucial for enhancing crop resilience in the face of climate change. This thesis explores plant stress adaptation mechanisms through two interlinked studies that address different aspects of gene regulation. The first study investigates the transcriptional dynamics of Sorghum bicolor under drought and heat stress at 1-hour and 6-hour time points. By employing 3'-end RNA sequencing, this study provides a comprehensive temporal view of gene expression changes, revealing stress-responsive transcription factors, hormone-associated pathways, and chromatin regulators. The comparative analysis highlights both common and distinct molecular responses between drought and heat stress, providing insights …

Biological, Histological, And Immunohistochemical Responses To Heat Stress In Common Goldfish, Carassius Auratus, Ngozichukwu Francis Ngozichukwu

Theses and Dissertations

Global climate change has led to rising temperatures, posing significant challenges to aquatic ecosystems and the health of ectothermic species such as goldfish (Carassius auratus) This thesis investigated the effects of heat stress on growth performance, histological alterations, and molecular stress responses in the gill and kidney tissues of goldfish Fish were exposed to control (24°C), medium (28°C), and high (32°C) temperatures for two weeks Growth parameters, including instantaneous growth rate (IGR), absolute growth rate (AGR), body value gain (BVG), and condition factor, were evaluated alongside histological and immunohistochemical markers of stress Results revealed that high temperature significantly reduced AGR …

Opa1-Mediated Mitochondrial Dynamics In Myogenic Differentiation Of C2c12 Myoblasts, Daniel Eloy Bazan

Theses and Dissertations

Mitochondria play a pivotal role in metabolic energy production, cellular signaling, and apoptosis. To carry out these key cellular roles, mitochondria dynamically balance their organization through opposing including fusion and fission processes. The balance between mitochondrial fusion and fission is regulated by key proteins such as OPA1 (optic atrophy 1) and OMA1 (overlapping activity with metalloprotease). More recently, mitochondria have been increasingly revealed to play key roles in cellular differentiation, where metabolic demands are reprogrammed. This study aims to elucidate the specific roles of OPA1 and OMA1 in the differentiation of C2C12 myoblast cells into myotubes.

Our data demonstrates that …

Endotherm Energetics Under Environmental And Physiological Constraints, Zachary Andrew David

Biological Sciences Theses & Dissertations

Metabolic rate governs how animals allocate energy toward maintenance, activity, growth, and reproduction, linking physiology to environmental context. This dissertation investigates how two endothermic mammals regulate metabolic rate in response to environmental variability, focusing on thermoregulatory flexibility and physiological constraints. Using flow-through respirometry, I measured resting metabolic rates (RMRs) in two complementary systems: tropical bears housed in semi-natural outdoor enclosures and marsh rice rats (Oryzomys palustris) exposed to controlled thermal treatments. Asiatic black bears (Ursus thibetanus) exhibited unexpectedly low mass-specific metabolic rates even under high ambient temperatures, yet their RMR increased with temperature, suggesting proximity to their …

Towards Improving Computational Modeling Of The Lumbar Spine - Impact Of Material Properties And Laminotomy On Spinal Biomechanics, Isaac K. Kumi

Mechanical & Aerospace Engineering Theses & Dissertations

Spinal ligaments play a crucial role in maintaining the mechanical stability of the lumbar spine. These dense, collagenous tissues not only resist excessive motion but also distribute loads between spinal components to protect neural structures. Traditionally, the mechanical response of ligaments has been modeled using linear elastic assumptions, which treat the tissue as having a constant stiffness regardless of loading history. While this simplifies analysis, it fails to capture the time-dependent behaviors, such as creep, stress relaxation, and hysteresis, that are characteristic of biological tissues.

Viscoelastic modeling may provide a more physiologically accurate representation by incorporating both elastic and viscous …

Effects Of Sediment Composition On Spartina Alterniflora And Juncus Roemerianus Productivity In Coastal Virginia: A Thin-Layer Sediment Placement Experiment, Caitlin Hemphill

Biological Sciences Theses & Dissertations

Climate change poses a major threat to the health of estuaries and their coastal wetland systems. The Chesapeake Bay’s coastal salt marshes are at high risk of inundation due to sea-level rise and land subsidence. Restoration techniques for maintaining coastal marsh resistance to sea-level rise are being developed and refined, with thin layer placement (TLP) emerging as a feasible solution in many areas of the United States. Despite TLPs use across the country, additional research is needed on species-specific responses, sediment types, and geographically focused studies in the lower Chesapeake Bay. My research addresses these gaps by combining both greenhouse …

Role Of Cellular Proteins In The Regulation Of Herpes Simplex Virus Type 1 Gene Expression And Dna Replication, Joseph R. Heath

Electronic Theses and Dissertations

Herpes simplex virus type 1 (HSV-1) is a ubiquitous human pathogen that infects the majority of the human population. To facilitate infection, this virus relies on a combination of host and viral factors. Previous studies have revealed a number of host proteins that associate with the HSV-1 genome throughout infection but their putative role(s) in this process remain undefined. This study aims to examine two such proteins to determine their contributions to HSV-1 gene expression and DNA replication. The first of these factors is Ints3, a subunit of the Integrator complex. This protein complex functions in transcription regulation, and Ints3 …

Life Cycle Assessment Of The Cultivation Of Lettuce In A Hydroponic System Using The Nutrient Film Technique, Raquel Jordan

All Theses

Hydroponic systems are an emerging method of soilless crop cultivation typically done inside a greenhouse where nutrients are delivered dissolved in water rather than being supplied from the soil. Potential benefits of hydroponic systems include reduced irrigation requirements, higher crop yield per area, and the ability to grow crops year-round in nontraditional areas such as urban settings, cold climates, and sites with contaminated soil. However, hydroponic systems tend to have high energy requirements for lighting and climate control, which can yield significant environmental impacts. To explore the environmental impacts of cultivating lettuce in a nutrient film technique (NFT) hydroponic system, …

3,5-Dihydroxy-4-Isopropylstilbene (Tapinarof) Is A Partial Aryl Hydrocarbon Receptor Agonist In Fish, Conner A. Dicks

All Theses

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is essential in regulating development, immune homeostasis, and drug and xenobiotic metabolism. Activation of the AHR by specific ligands results in its translocation to the nucleus where it induces a myriad of gene products, including cytochrome P450 (CYP) drug metabolizing enzymes (e.g., CYP1A1) and other components of the chemical defensome, as well as inflammatory control. Interestingly, the AHR can bind a wide variety of endogenous and xenobiotic ligands which are able to induce unique downstream effects dependent on cell type, inflammatory context, and ligand stability. The AHR is …

Investigating Rattlesnake Social Networks And Improving Their Public Image Through Unobtrusive Technologies And Community Science, Owen M. Bachhuber

Master's Theses

While technology is often blamed for humans’ increasing disconnect with nature, it can also serve as a tool to facilitate empathy and conservation action for wildlife. Snakes are among the most feared animals on the planet, though their understudied social interactions provide opportunities to make scientific discoveries and change public perceptions. Project RattleCam was founded as a camera trap project in 2021 and launched the first off-grid livestream on a den of wild Prairie Rattlesnakes (Crotalus viridis) in 2024. Both camera types captured hundreds of Prairie Rattlesnakes gathering in the summer as they prepared to give birth to pups before …