Digital Commons Network^™

Site Fidelity, Seasonality, Movement, And Fish Associates Of Sand Tigers Carcharias Taurus In North Carolina, Ara L. Mcclanahan

Electronic Theses and Dissertations

Sand tigers Carcharias taurus are mackerel sharks with a disjunct global distribution in tropical and temperate seas. In the northwest Atlantic, sand tigers migrate along the coast of the eastern United States from the Gulf of Maine to Florida and occupy structurally complex benthic habitats. The long-term, underwater camera installation, SharkCam, at Frying Pan Tower, off Cape Fear, North Carolina, USA, sits atop an expanse of hard bottom reef frequented by sand tigers. The citizen-science platform Spot A Shark USA (SAS USA) uses images of sand tigers to identify and track individuals. This study utilized image encounters from SAS USA …

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 …

Evaluation Of Performance Characteristics And Groundwater Contamination Risks Associated With On-Farm Swine Carcass Disposal Via Composting And Shallow Burial With Carbon, Gustavo Castro Garcia

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

This dissertation evaluates the performance of three on-farm swine carcass disposal methods: whole carcass composting (WCC), ground carcass composting (GCC), and shallow burial with carbon (SBC), focusing on biosecurity factors and groundwater contamination risks. Foreign animal diseases (FADs), such as African swine fever and classical swine fever, pose severe economic and animal well-being risks if introduced to the United States. With confirmation of an FAD, swine movement will be halted, creating an urgent need for practical, biosecure, and environmentally responsible on-farm disposal strategies for swine carcasses. Nebraska, as a leading swine-producing state, exemplifies the vulnerability of high-density livestock regions to …

Educating The New Generation Of Food Scientists Through Innovative Learning Experiences, Karen Andrea Nieto Flores

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

Food science provides an opportunity to engage high school students in Science, Technology, Engineering, and Mathematics (STEM) by connecting classroom concepts to real-world applications. Despite the field’s relevance to public health, food safety, sustainability, and innovation, food science remains largely absent from high school curricula, and few students recognize it as a viable STEM pathway. This research addressed this gap by evaluating immersive summer camp experiences and teacher-focused curriculum review as strategies to increase food science awareness and interest among students and educators. A literature review traced the historical development and current landscape of K–12 food science education, identifying barriers …

Egg White Hydrolysate In Hypertension: A Mechanistic Investigation Of Gut Microbiota Dependent And Independent Pathways, Emerson David Nolasco

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

Cardiovascular diseases are one of the leading causes of mortality worldwide in which hypertension is a risk factor. Present pharmacological interventions require long-term adherence to the therapy and are often associated with undesirable side effects. Moreover, treatments have overlooked the role of the microbiome in the development of hypertension. Egg white hydrolysate (EWH) has exhibited antihypertensive properties with potential to be used as a natural alternative for the prevention and management of hypertension. However, EWH peptide’s effect on the gut microbiome remains yet to be elucidated. Studies have described that a portion of the ingested protein can remain undigested 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 …

Aptamer Selection And Development Of Electrochemical Aptamer-Based Sensors For Neuropeptide Y, Evelyn Adela Carreto Guevara

Department of Chemistry: Dissertations, Theses, and Student Research

In this thesis, we report the results of four aptamers obtained from an aptamer selection process called the systematic evolution of ligands by exponential enrichment (SELEX) with affinity to Neuropeptide Y (NPY). NPY is a highly abundant peptide transmitter with widespread distribution throughout the body which affects various physiological functions. These functions include energy homeostasis, appetite regulation, stress response, and anxiety regulation. Dynamic monitoring of NPY levels is crucial for better understanding behaviors in individuals with neurological disorders associated with NPY. Aptamers are synthetic oligonucleotides obtained through SELEX which have a binding affinity to a target of interest when in …

Breaking Confirmatory Spells By Implementing Research- Integrated Cures, J. A.C. Vriezen

Biological Sciences: Faculty Publications

Differences in economic and social growth and academic equity, experi ences, and opportunities have left an achievement gap in STEM for underprivileged students. Course-based Undergraduate Research Experiences (CUREs) have attempted to answer these inequalities by leveling the playing field or by offering course-based research opportunities with minimal requirements for background knowledge. When we ask novel questions, more students get the experience of performing research, which lowers thresholds to pursue research and increases participation. Although the learning outcomes have been largely positive, there is a concern that many CUREs are still too scaffolded. In contrast, I propose to develop exploratory, hypothesis-driven …

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 …

Local Adaptation In The Pinus Palustris Ground Layer, Jason Paul Joines

All Dissertations

Population survival or extirpation may be dependent on adaptation to local environmental conditions. I hypothesized that populations of species with large ranges would be locally adapted because of the variety of environments that different populations experience, that spatial patterns of local adaptation would correspond to patterns of endemism because processes driving local adaptation may also lead to speciation, and that the extent of local adaptation would be stronger in species with little gene flow among populations than in those with extensive gene flow because of the relative strength of selection necessary to overcome gene flow. I tested these hypotheses using …

Expression Of Glycine Transporter 1 In The Rodent Basal Ganglia: Glial Vs. Neuronal, Rosa Atziri Perez

Open Access Theses & Dissertations

Glycine functions as an inhibitory neurotransmitter in the central nervous system (CNS),and it is mainly involved in autonomic functions. The levels of extracellular glycine are regulated by two membrane transporters, glycine transporter 1 and glycine transporter 2 (GlyT1 and GlyT2, respectively). These transporters differ in function and localization within the CNS. For many years, studies suggested that only GlyT2 served as a neuronal marker; however, GlyT1 has been localized in neurons in recent studies. The expression of GlyT1 is widespread compared to GlyT2; hence, the main objective is to determine the nature of the expression of GlyT1 in areas devoid …

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 …

Trophic Roles And Climate-Driven Vulnerability For Benthic Invertebrates At Artificial Reefs In The Northern Gulf Of Mexico, Amanda Kirkland

LSU New Orleans Theses and Dissertations

Artificial reefs are deployed to enhance marine habitats and fisheries, yet their role in supporting secondary production and their vulnerability to climate stressors remain understudied. This dissertation investigates the trophic ecology and climate sensitivity of benthic invertebrates at artificial reefs in the northern Gulf of Mexico. Chapter 1 assessed reef food webs using stable isotopes from fishes, invertebrates, and primary producers across six reefs and two seasons. Mixing models showed that most fishes rely on benthic reef carbon, while suspension feeders consume plankton and sediment microphytobenthos. Isotopic niche analysis revealed functional diversity and seasonal shifts in δ¹³C and δ³⁴S, though …

Elucidating The Mechanisms Underlying A Functional Plant-Arbuscular Mycorrhizal Symbiosis Using Omics Approaches, Jasmine Gill

All Dissertations

Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs forming symbiotic association with plants. The plant-AMF symbiosis has gained much attention due to its ability to improve plant nutrient uptake, especially phosphorus, which is often inadequately available to plants due to its limited mobility and complex formation in many soils. Phosphorus (P) is a crucial nutrient for plants, and most phosphate fertilizers are derived from phosphate rock, a finite natural resource. Thus, optimizing P uptake is vital for sustaining crop yields and addressing the needs of a growing global population. Plant-AMF symbioses are significant in this context, as AMF can acquire P …

Alternative Therapeutics For Human Breast Cancer: Nutraceutical Underpinnings, In Vitro Metabolomic Profiling, Treatment Efficacy, And Contextual Ethical Implications, Aubrey A. Mattingly

All Dissertations

Breast cancer remains one of the most prevalent diseases worldwide, yet therapeutic equity is still lacking. Standard treatments including surgery, radiotherapy, chemotherapy, and long-term hormone therapy. These approaches are often accompanied by significant side effects. While newer methods such as immunotherapy and targeted therapies have emerged, chemotherapy protocols and incorporation have remained largely unchanged in the past decades. In this context, nutraceuticals represent an alternative or adjuvant to therapy worthy of exploration. The reviewed literature highlights the anti-carcinogenic activity in selected nutraceuticals, marjoram, thyme and persimmon, considering their phytochemical constituents and secondary metabolites. Metabolomic profiling using the Biolog Phenotype Mammalian …

Soil Health On Utah's Farms And Ranches, Jenae Dean

All Graduate Theses and Dissertations, Fall 2023 to Present

The term soil health has gained popularity in agriculture due to prolonged droughts, rising food costs, and the growing public concern for sustainable and organic practices. Soil health practices can offer solutions to all of these pressures. This thesis provides Utah's farmers and ranchers with quantifiable data on implementing soil health practices in Utah's unique climate. It presents the first two years of on-farm trial results on yield and quality after implementing various soil health practices on five categories of crops: corn, mixed hay, alfalfa, produce, and dryland grain. Over a two-year period, none of the soil health practices resulted …

Group I Introns As Catalytic Rna Models To Investigate The Origin Of Life And To Explore The Drivers Of Evolution In The Rna World, Gianluca Peri

Boise State University Theses and Dissertations

The RNA World is the theory that life on Earth originated as RNA molecules able to both carry genetic information and catalyze enzymatic activities, without the need of DNA nor proteins. Abundant evidence supports that RNA preceded the emergence of DNA and proteins, the most notable being that both DNA replication and protein synthesis require RNA components. It has been hypothesized that the RNA World originated as a self-replicating RNA system. Furthermore, since the activity of modern-day catalytic RNA (ribozymes) can be affected by reaction conditions (e.g. Mg^2+ cofactor concentrations), it is hypothesized that evolution in the RNA World may …

Identification Of Anti-Inflammatory Pathways Induced By Enterotoxin B Subunits For Use As Therapeutics In Inflammatory Bowel Disease, Hannah Juel Hedelius

Boise State University Theses and Dissertations

Vibrio cholerae’s AB5 enterotoxin, cholera toxin (CT), has a homopentameric, non-toxic B subunit (CTB). CTB is a well-known vaccine adjuvant used for its ability to create a strong immune response, however more recent studies have shown its ability to also behave in an anti-inflammatory manner, performing as a protective agent in a variety of different inflammatory diseases. Escherichia coli (E. coli) produces a heat-labile AB5 enterotoxin (LT) that is very homologous to CT, with its B subunit (LTB) being used in a similar manner as a vaccine adjuvant. There have been many studies comparing LTB to CTB due …

Social And Economic Gradients Of Resource Transfer Behavior In Gorongosa, Mozambique, Karl J. Mertens

Boise State University Theses and Dissertations

Why do people who experience the same environmental and social conditions vary so much in their resource transfer behavior? This dissertation addresses that question through examination of behavioral variation in subsistence horticulturalists in the dry tropical forest bufer conservation area of Gorongosa National Park in Mozambique. In this region of moderate and acute food shortages at both household and regional levels, individuals face similar challenges of addressing social and resource uncertainty yet respond with marked behavioral variation that cannot be explained solely by diferences in wealth, kinship, or reciprocity patterns.

Using a Behavioral Reaction Norms (Dingemanse et al., 2010) (BRN) …

Optimizing Delphinium And Larkspur Through Timing And Protective Cultivation Methods For Cut Flower Production, Nicholas Kirwan Volesky

All Graduate Theses and Dissertations, Fall 2023 to Present

Cut flowers have become an increasingly important specialty crop for small farms nationwide, and particularly in Utah, where decreasing agricultural land has heightened the need for profitable cropping options. However, production is challenged by Utah’s high-elevation climate, which presents unique constraints not addressed by current recommendations. Cool-season crops, like delphinium (Delphinium spp.) and larkspur (Consolida ajacis L.), are underproduced yet highly marketable, generating strong interest among growers throughout the state. Developing region-specific production guidelines is essential to help optimize yields, extend harvest windows, and meet local demand. This research evaluated spring planting dates in high tunnel and field …

Habitat Selection Analysis Of Mule Deer To Determine Efficacy Of The Coyote Bounty Program In Utah, Xaela M. Walden

All Graduate Theses and Dissertations, Fall 2023 to Present

Mule deer populations have been declining over the past couple of decades in many parts of the western United States. Often times, predators are blamed for the decreases in deer populations. Because of this, wildlife managers implement programs focused on reducing the number of predators on the landscape in an attempt to increase deer populations. However, predator removal programs have had mixed results, thus further investigation is needed to determine if coyote removals by the public through a bounty program have a positive effect on mule deer populations. My study investigated whether coyote removals through the bounty program in Utah …

Coyote (Canis Latrans) And Non-Target Wildlife Responses To Livestock Guardian Dogs At Sheep Grazing Sites On The California Central Coast, Tricia T. Nguyen

Master's Theses

Livestock depredation is one of the oldest and most widespread forms of human-wildlife conflict. The coyote (Canis latrans), a midsized canid, represents a significant proportion of domestic sheep depredations in the United States, costing livestock producers an estimated 24.6 million dollars annually. Management strategies for coyote-sheep depredation vary widely in their effectiveness and in their level of public support. Identifying appropriate strategies for farms, ranches, and other sheep grazing sites remains a pressing need due to the potentially negative consequences for surrounding ecosystems and socioeconomic outcomes for sheep producers. The livestock guardian dog (LGD) is a nonlethal control …

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 …

Analysis Of The Scleroderma / Systemic Sclerosis Etiopathology Using The University Of California At Davis (Ucd)-Ssc Chicken Line, Angeline E. Rodriguez

Graduate Theses and Dissertations

Scleroderma/Systemic Sclerosis (SSc) is a multifaceted autoimmune disorder affecting approximately 300,000 people in the United States. Main features include vasculitis, immune dysfunction (innate and adaptive), autoantibody production, perivascular leukocyte infiltration, and extensive tissue fibrosis. The University of California, Davis (UCD) SSc chicken line was shown to exhibit all clinical and biological manifestations of human SSc. One early and distinctive clinical sign in both humans and UCD-SSc chickens is Raynaud’s phenomenon (RP), characterized by decreased blood flow in extremities and skin lesions. RP-like lesions develop in combs of UCD-SSc chickens within one- to two-weeks post-hatch, progressing from erythema and edema to …

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 …

Human Salivary Gland Stem/Progenitor Cells For Tissue Engineering, Sars-Cov-2 Susceptibility, And Neurointegration, Caitlynn Barrows

Dissertations and Theses (Open Access)

Salivary glands and the saliva they secrete are important for digestion, chewing, and maintaining oral health. Reduced saliva production leads to a decreased quality of life for patients experiencing hyposalivation as a result of disease or injury, thus a large effort has been dedicated to developing materials and medium to recapitulate the structure of the gland for regenerative medicine. In doing so, we have come closer to developing a more complex model to study disease. These models, however, do not yet fully recapitulate the gland. In this dissertation, we describe a new cell source that can be used to develop …

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 …

Clonal Phenotype Mapping Reveals Genomic Alterations Underlying Tumor Immunosuppression During Immunotherapy, Er-Yen Yen

Dissertations and Theses (Open Access)

Tumors are dynamic ecosystems that evolve under selective pressures, shaping their ability to either elicit or evade immune responses. In pancreatic ductal adenocarcinoma (PDAC), where immunotherapy has yet to become an effective treatment option, we investigated the role of intratumoral heterogeneity in influencing immune interactions. Using orthotopic clonal replica tumors, we tracked clonal dynamics in response to anti-PD1 therapy and found that while treatment had limited impact on overall tumor volume, it induced profound shifts in clonal composition. Spatial lineage analysis of treatment-naïve tumors revealed that clones with distinct immunotherapy sensitivities occupy unique tumor microenvironments, a pattern that remained stable …