Digital Commons Network^™

Improving Glycemic Control Mechanisms By Electrical Muscle Stimulation, Jehu Narh Apaflo

Open Access Theses & Dissertations

Introduction: Neuromuscular electrical stimulation (NMES) has emerged as a promising intervention for improving metabolic health in sedentary individuals with overweight or obesity. Its capacity to induce muscle contraction without voluntary movement presents a viable alternative to traditional exercise, especially in mobility-limited populations. NMES may serve as a non-invasive alternative to traditional exercise, especially in high-risk populations who face elevated type 2 diabetes incidence linked to hyperglycemia, obesity, and inactivity. This study investigated the impact of NMES on glycemic control and metabolic health in a sedentary, predominantly Hispanic, overweight or obese population. Methods: This study examined the acute and long-term effects …

Systematics Of African River Frogs (Anura: Pyxicephalidae: Amietia) In Central Africa, With The Description Of Two New Species, Jesus Manuel Reyes

Open Access Theses & Dissertations

Amietia is a pyxicephalid anuran genus that is prevalent throughout central, southern, and eastern portions of sub-Saharan Africa. Recent phylogenetic studies have been in conflict regarding the validity and composition of several Amietia species in the Albertine Rift region. The goals of this study are to: (1) generate an updated molecular phylogeny for Central African Amietia with new sampling; (2) clarify the relationship between the previously unsampled taxa A. amieti and A. chapini; (3) clarify the status of A. desaegeri; and (4) confirm the taxonomic status of potentially new species. Maximum likelihood and Bayesian inference methods were used to generate …

Spatial And Thermal Aspects Of The Ecology Of Three Sympatric Rattlesnakes In The Montane Northern Chihuahuan Desert, Joshua James Mead

Open Access Theses & Dissertations

To understand how animals coexist on the landscape, the individual aspects of a species life history must first be understood. Animals need to find locations that provide the resources they need to survive. Movement, microhabitats, and temperature can alter such areas where animals occur. Understanding animal movements provide important information on space use and microhabitats on the landscape. Ectothermic animals must acquiesce to ambient temperatures or use behavioral modifications to alter their body temperature. The ability to maintain suitable body temperature is essential for physiological function, reproduction, and ability to avoid predation. Research on the variation in a species ecology …

Phylogenetics And Integrative Taxonomy Of The Lang's Reed Frog Species Complex (Anura: Hyperoliidae: Hyperolius Langi), Dominic Troiani

Open Access Theses & Dissertations

The genus Hyperolius (Rapp, 1842) is the most speciose amphibian genus in sub-Saharan Africa. The genus has a complex taxonomic history because of its extensive intraspecific and interspecific morphological variation, large geographic distribution of many taxa, gaps in sampling, and the discovery of significant cryptic diversity within many species. The goal of this study is to understand the relationships and taxonomy of Hyperolius langi via an integrative taxonomic approach that combines molecular, morphological, and bioacoustics data to clarify the systematics of the geographically widespread species Hyperolius langi. Two mitochondrial (16S and cyt b) and one nuclear (RAG1) gene were used …

Stress-Survival Pathway Genes In Colorectal Cancer: Crc Progression And Hispanic Disparities, Highlighting Mcm10 As A Potential Player, Urbashi Basnet

Open Access Theses & Dissertations

Despite advances in screening and treatment, colorectal cancer (CRC) remains a leading cause of cancer-related deaths in the U.S., with notable disparities across racial and ethnic groups. Hispanic populations face a disproportionate burden, underscoring significant differences in incidence and outcomes. This study examines the role of the Stress-Survival Pathway (SSP) in colorectal cancer (CRC), with a focus on addressing health disparities among Hispanic populations. Twenty-eight differentially expressed SSP genes identified from bioinformatic analysis were validated in CRC cell lines and cDNA arrays using qRT-PCR and tissue microarrays by immunohistochemistry. SSP genes were further analyzed in CRC tissues from Hispanic and …

Investigating The E74-Mediated Regulation Of A Gata Factor In Aedes Aegypti Mosquitoes, Jacklyn Marie Estrada

Open Access Theses & Dissertations

The mosquito species Aedes aegypti has a significant impact on public health as a vector for multiple pathogens. Its ability to transmit deadly diseases, including Yellow Fever, Dengue Fever, and Zika, emphasizes the urgency of understanding its reproductive biology. In female mosquitoes, reproductive success hinges on obtaining a vertebrate blood meal, which triggers vitellogenesis - the synthesis of yolk protein precursors (YPPs) necessary for egg development. Without a blood meal, female Ae. aegypti remain in a state of previtellogenic arrest, where the YPP gene vitellogenin (Vg) is repressed by a type of transcriptional factor, GATAr (AaGATAr) (Attardo et al., 2003). …

Environmental Drivers Of Vegetation Dynamics In Constructed And Natural Wetlands Of The Chihuahuan Desert, Enrique David Garcia

Open Access Theses & Dissertations

Desert wetlands are critical ecosystems that provide water, food, and habitat for many different species at different trophic levels. Additionally, they have the capacity to recharge aquifers, control floods, and purify water, among others. Unfortunately, they have been facing multiple environmental challenges due to different human activities, sometimes with disastrous consequences. There is an urgent need to better understand the structure and function of wetlands of different types and in different biomes in order to conserve, restore, and even create them so we can continue to obtain all the ecological services they provide. In this dissertation, I investigated how environmental …

An Evaluation Of Key Components Of Natural Resource Camps, Undergraduate Persistence And Success In Natural Resources, Brandy Bishop

Electronic Theses and Dissertations

This study explores the key components that connect natural resource camps, undergraduate persistence, and overall success through gainful employment within the natural resource industry. The aim of this study was to assess early interest and attitudes towards natural resource career pathways and how education interventions shape students’ career outcomes thus leading to overall success. A longitudinal mixed method design was used combining Conservation Careers Camp survey data (n = 39) with institutional records for Forestry majors (n =655) in the Arthur Temple College of Forestry and Agriculture on the Stephen F. Austin State University campus. Quantitative data was analyzed through …

Stand Strucuture Of Planted Stands In Storm-Water Retention Basins, Jason Lanza

Electronic Theses and Dissertations

Trees assist in stormwater retention basin functionality as efficient sources of water removal, and determining stand structure and leaf area of forests can be a measure of their effectiveness. The structure of forest stands on these basins managed for runoff mitigation has received little attention. We investigated the structure and species composition/diversity (tree and herbaceous) of planted, managed stands and naturally regenerated stands on stormwater retention basins managed by Harris County Flood Control District in Harris County, Texas. We determined stand structure variables (trees per hectare, basal area per hectare, quadratic mean diameter, relative density, average tree height, and percent …

Effect Of Marination And Storage Time On The Properties And Meat Quality Of Broiler Breast, Mayra Mabel Herrera Rivera

Graduate Theses and Dissertations

Abstract The poultry industry has implemented numerous methods, as marination and aging, to improve meat quality and satisfy consumer demands. Three experiments were developed to assess the effects of vacuum tumble marination and aging on the proteins of chicken breast. These experiments utilized 0.75 % sodium chloride, 0.45 % phosphate, and water in a marinade. In experiment one, 270 fillets were allocated into six treatment groups, each comprising 45 fillets. Six days of storage time were used, marinating and storing the fillets in each group at a temperature of 4°C. Following each day of storage period, the fillets underwent a …

Modeling U.S. Corn Production Archetypes In The Agricultural Policy/Environmental Extender Model To Generate Life Cycle Assessment Inventory Data, Brandon Taylor

Graduate Theses and Dissertations

Corn (Zea mays) is an important crop grown across the US for many uses such as grain for animal feed, bio-ethanol production, food products, and industrial products. Corn is produced in almost every state in the US, but most corn production is concentrated in the Corn Belt Region including Iowa, Illinois, Ohio, Indiana, Minnesota, and Nebraska. Although technologies and production practices are improving corn production efficiency primarily through increased yields (improved land use), corn production at this scale greatly impacts the environment through emissions from fertilizer and pesticide runoff and leaching, soil degradation due to improper field practices, as well …

Effects Of Flavonoids On Reducing Colon Cancer Risk Via Macrophage Polarization, Gracien Jules

Graduate Theses and Dissertations

Colorectal cancer is one of the most fatal diseases in the United States. Chronic tissue inflammation can cause cell proliferation, which leads to tumor formation and cancer development. Macrophages are responsible for maintaining tissue homeostasis and for inflammatory responses. M1 macrophages exhibit proinflammatory responses while M2 macrophages exhibit anti-inflammatory responses. Imbalance between M1 and M2 macrophages is closely related to inflammation-associated disease development. The anti-inflammatory effects of apiaceous vegetable constituents, specifically flavonoids, have been studied for their preventative effects towards reducing disease risk. However, sufficient evidence is lacking on the mechanisms by which flavonoids impact M1/M2 macrophage polarization. RAW 264.7 …

Examining The Use Of Two-Dimensional Video Capture And A Pressure Sensing Walkway For Collection Of Obstacle Crossing Measures, Ashlyn M. Jendro

Graduate Theses and Dissertations

Obstacle crossing research is crucial for providing insights into how and why people trip and fall. However, a growing body of literature has proposed that laboratory-based studies may not directly translate into real-world settings due to the complex nature beyond the sterile lab. Unfortunately, the absence of real-world obstacle crossing literature is likely due to a lack of available validated methods for collection of data outside the laboratory. This dissertation explored two potential methodologies (i.e., 2D motion capture and a pressure sensing walkway) that are more portable and cost-effective for collecting real-world obstacle crossing measures. It is hypothesized that 2D …

Freezing And Shipping Optimization To Increase Quality And Profitability Of Meat E-Commerce, Paul Olaoluwaniyi Dahunsi

Graduate Theses and Dissertations

Freezing remains one of the most reliable methods for preserving meat quality and extending shelf life. However, quality deterioration can still occur due to structural and biochemical changes activated during freezing, thawing, and distribution. Since the COVID-19 pandemic, consumers’ preference for bulk purchasing and online meat shopping has increased, raising questions about the best strategies to balance both quality maintenance and profitability. This thesis aimed to evaluate two key stages where frozen beef is most vulnerable to quality degradation: consumer-level freezing and post-purchase shipping. The objectives were (1) to determine the effects of product size and subsequent consumer freezing practices …

Hepatic Lipid Metabolism Of High And Low Water-Efficient Broiler Lines Under Heat Stress, Maria Fernandez Cuadrado

Graduate Theses and Dissertations

Heat stress (HS) is one of the most critical environmental challenges negatively impacting global poultry production, significantly compromising broiler performance, welfare, and economic viability. Specifically, heat stress profoundly disrupts physiological and metabolic processes, including hepatic lipid metabolism. Two broiler lines were divergently selected for high (HWE) or low (LWE) water efficiency. Heat-stressed HWE birds showed reduced fat content compared to their LWE counterparts, and HS reduced abdominal fat content in both lines. The purpose of this study was to determine the difference in underlying molecular mechanisms involved in this divergent fat content between the lines. Day-old chicks were placed in …

A Multicomponent Microneedle Patch For The Delivery Of Meloxicam For Veterinary Applications, Katherine Alejandra Miranda Munoz

Graduate Theses and Dissertations

Veterinary medicine requires innovative drug delivery strategies to enhance therapeutic efficacy while minimizing stress and handling. This dissertation explores the development and application of biodegradable microneedle patches for the transdermal delivery of meloxicam in livestock, offering a minimally invasive alternative to traditional administration methods. The research investigates the fabrication and characterization of microneedles using polyvinyl alcohol, collagen, and chitosan blends, demonstrating their mechanical strength, biocompatibility, and ability to facilitate sustained drug release. In vitro and in vivo evaluations confirm effective skin penetration, dissolution, and localized drug delivery. Pharmacokinetic studies highlight anatomical site-dependent variations in drug absorption, emphasizing the need for …

Impact Of Lighting Wavelength On Broiler Behavior, Health, And Performance, Angela Perretti

Graduate Theses and Dissertations

Lighting influences broiler production, health, and behavior. Due to their advanced visual system, avian species perceive a wide spectrum of light. The objective of this study was to investigate the effects of white (W, 350 to 780 nm) blue (B, 450 nm), and green (G, 560 nm) light on broiler production, processing performance, activity, fear, stress, blood cell profiles, tibiotarsi (tibia) morphology, and depth perception. Day-of-hatch by-product chicks from a Cobb 500 female line (N=600) were randomly assigned to 12 pens (N=4 treatment replicates). Body weight and feed consumption were recorded on day (D) 0, 14, 28, and 41, and …

Insights Gained From Applying Molecular Techniques To Gray Triggerfish (Balistes Capriscus Gmelin, 1789) In The Mexican Caribbean, The Southern And Northwestern Gulf Of Mexico, Geaceli G. Orive

Theses and Dissertations

This study focuses on Balistes capriscus (Gray Triggerfish), a reef-associated species dependent on hard-bottom habitats in the Gulf of Mexico (GOM). Using mitochondrial DNA barcoding and phylogenetic analyses, genetic structure across four sites was assessed: Rio Grande Valley (RGV), Veracruz, Chinchorro Bank, and Xahuayxol. Samples from RGV and Veracruz exhibited limited haplotype diversity, minimal nucleotide divergence, and weak genetic differentiation-patterns consistent with recent population expansion and ongoing connectivity within the GOM. While the study centered on B. capriscus, all individuals from Chinchorro and Xahuayxol unexpectedly grouped with Canthidermis maculata (Spotted Oceanic Triggerfish), suggesting misidentification, cryptic diversity, or taxonomic uncertainty in …

The Effect Of Diet Formulations Containing Different Protein Sources On Energy And Nitrogen Utilization In Lactating Jersey Cows, Kortney Ann Harpestad

Department of Animal Science: Dissertations, Theses, and Student Research

It is well understood that lactating dairy cows require metabolizable protein (MP) for milk yield and milk protein synthesis. Diets with conventional feed sources like corn and soybean meal (SBM) may not sufficiently meet all MP and amino acid (AA) requirements so supplementation with more rumen undegradable protein (RUP) rich feeds or rumen-protected AA can be fed to support animal performance. The growth trajectory of biofuels has resulted in dramatic increases in the production of feeds like heat treated soybean meal (HTSBM). While the chemical composition of this product is understood, there is a need to better understand how HTSBM …

Authentication And Message Integrity Verification For Emerging Wireless Networks, Ebuka Philip Oguchi

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

This dissertation presents a comprehensive body of research on authentication and message integrity verification for emerging wireless networks, focusing on secret-free and physical layer security techniques across diverse, challenging, and unconventional environments.

It comprises four first-author contributions that span underground wireless systems, over-the-air (OTA) channels, vehicular communications, and nanoscale molecular networks.

The first contribution, Soil-Assisted Trust Establishment for Underground Wireless Networks (STUN), introduces a physical-layer trust bootstrapping protocol that achieves authentication and message integrity without pre-shared secrets. Leveraging underground-to-air propagation laws and trusted relay nodes, STUN resists active signal injection attacks and demonstrates security comparable to the unbalanced oil and …

Impact Of Adoption Of Fall Armyworm And Stemborer Pest Control Practices On Maize Yields In Rwanda: A Multinomial Endogenous Switching Regression Approach, Vincent Gadamba Misango, Jonathan Makau Nzuma, Patrick Irungu, Menale Kassie

All Peer-Reviewed Publications

The use of push-pull technologies (PPT) as an alternative control method for fall armyworms and stemborer pests amongst maize farmers has recently received considerable global attention. However, the impact of adoption of PPT on the maize productivity remains largely unexplored. This study used a multinomial endogenous switching regression (MESR) to evaluate the impact of adoption of PPT on smallholder maize farmer's yields in Rwanda. The MESR model was estimated on a sample of 398 households operating 967 maize plots selected using a stratified random sampling technique. Overall, 25, 20, and 14 percent of the households used traditional methods, PPT and …

Heterogeneous Yield Effects Of Cover Crop Adoption In U.S. Corn And Soybean Systems, Ethan Kendall

Graduate Theses and Dissertations

Identifying the conditions where cover crops will succeed or fail is crucial for advancing conservation agriculture. Cover crops have been widely accepted as a conservation practice that can improve soil health and might improve or stabilize crop yields, though these benefits are not consistent across different regions. This study examines how heterogeneous factors can shape the effectiveness of cover crops on corn and soybean yields across the United States. Using the National Commodity Crop Productivity Index (Index) to measure soil productivity, this study examines how cover crop impacts vary across different levels of soil quality. A county level, 16- year …

Bifunctional Fusion Protein Pdl1sfv/Micae For Cancer Immunothearpy, Junyi Li

All Dissertations

Cancer immunotherapy has highlighted the importance of immune checkpoint blockade and innate immune cell engagement in battling tumor-mediated immune suppression in the past few decades. However, with cancer development, advanced tumors are often found to develop resistance towards single-target immunotherapy due to the complexity of the immunosuppressive mechanisms within the tumor microenvironment (TME). To address this, we developed a novel bifunctional fusion protein, PDL1sFv/MICAe, which combines the tumor-targeting capability of an anti-PDL1 single-chain variable fragment (sFv) with the NK cells immunostimulatory properties of the MICA extracellular domain.

In vitro functional assays revealed that PDL1sFv/MICAe significantly enhanced cytotoxicity towards natural killer …

Factors Influencing Swift Fox Reintroduction Success To Fort Belknap Reservation, Montana, Dana Nelson

All Dissertations

Reintroductions are an important conservation tool for reestablishing wildlife populations, and studying the factors influencing reintroduction outcomes is important to improving success rates over time. Swift fox are a small canid native to the short- and mixed grass prairies of western North America that have experienced severe population declines due to habitat loss and poisoning in the late 1800s. While swift fox now occupy approximately 40% of their historic range, reintroduction to northern Montana may promote the species’ long-term persistence, encourage connectivity in an existing range gap, and return species to areas where it is culturally significant. We studied the …

A Convergent Mixed Methods Study Of The Social Studies Academy In South Carolina Middle Schools, Audie Cherry

All Dissertations

There is a global labor shortage in the agricultural industry and middle school is a critical time to get students serious about career decision making. The Studies of Occupations, Culture, and Innovations toward Agricultural Literacy (SOCIAL) Studies Academy is a high impact professional development program in South Carolina that provides experiences and for middle school social studies teachers (N = 12) to become more suited to teach their standards associated with the agricultural sciences with hopes of encouraging more students to pursue agricultural careers. This study was a mixed-methods convergent parallel design that examined 1) Academy Fellows (n = 4) …

Adiponectin-Regulated Macrophage Responses In Aspergillus Fumigatus Infection: Mechanisms Of Uptake And Killing, Sri Harshini Goli

All-Inclusive List of Electronic Theses and Dissertations

Invasive aspergillosis (IA), caused by Aspergillus fumigatus, is a life-threatening infection in immunocompromised individuals, necessitating novel host-directed therapies. Macrophages are pivotal in antifungal defense, yet their function can be dysregulated; the influence of the adipokine adiponectin (APN) on this process is not fully understood. This thesis investigated the role of APN signaling in alveolar macrophage (AM) and bone marrow-derived macrophage (BMDM) responses to A. fumigatus and assessed the therapeutic potential of the APN receptor agonist, AdipoRon. Initial studies revealed that genetic deficiency in APN or its receptors renders AMs intrinsically pro-inflammatory and significantly impaired fungicidal activity against A. fumigatus. Subsequent …

Dermatoglyphic Fluctuating Asymmetry In Schizotypy, Marcus R. Thomas

All-Inclusive List of Electronic Theses and Dissertations

Schizotypy has been linked with many of the proposed endophenotypes of schizophrenia, but research is limited on the relationship between schizotypy and dermatoglyphic fluctuating asymmetry. The present study sought to examine relationships between schizotypy, dermatoglyphic fluctuating asymmetry, handedness, and season of birth. 146 undergraduate students were identified as schizotypes (n = 52) or controls (n = 94) based on the Multidimensional Schizotypy Scale and had their finger and palm prints collected along with completing additional measures of schizotypy and handedness. Schizotypes did not exhibit a greater degree of dermatoglyphic fluctuating asymmetry, negative schizotypy was associated with increased absolute finger ridge …

Applying Transcriptomics For Technology Development And Conservation In North American Marine Organisms, Cory Von Eiff

Dissertations

RNA biology is a rapidly expanding field, with many avenues of discovery among marine organisms. In this study, we analyze both mollusks and sawfish. First, we perform an evaluation of sRNA biogenesis pathways throughout Mollusca, with emphasis on the easter oyster, Crassostrea virginica. Understanding these molecules prescribes RNAi-based gene silencing approaches, benefiting genetic investigation and biotechnology. Similar to other animal groups, mollusks have conserved microRNAs (miRNAs), with some shared with ecdysozoans and deuterostomes; however, there is no evidence of an endogenous small interfering RNA (siRNA) pathway. These results suggest that long double-stranded RNA (dsRNA)-based RNAi is not appropriate for gene …

Crystal Structures Of Escherichia Coli Glucokinase And Insights Into Phosphate Binding, Joseph Andrews, Joshua Sakon, Chenguang Fan

Chemistry & Biochemistry Faculty Publications and Presentations

Here, we report the crystal structure of Escherichia coli glucokinase (GLK), which has phosphate bound in the cleft between the alpha and beta domains adjacent to the active site. A ternary complex consisting of GLK, glucose and phosphate is also reported in this work. Diffraction data were collected at 2.63 angstrom resolution for the phospate-bound form (R-work/R-free = 0.191/0.230) and at 2.54 angstrom resolution for the ternary complex (R-work/R-free = 0.202/0.258), both at 297 K. A B-factor analysis of the phosphate-bound GLK structure revealed consistently lower values for phosphate-interacting basic residues in the alpha 4, alpha 5 and alpha 9 …

Evaluating Quadrupedal Locomotion In Bats: A Geometric Morphometric Comparison Of Vertebral Adaptations Across Mammals, Jessica Upham

Electronic Theses and Dissertations

Flight is the primary locomotion of bats, while quadrupedal locomotion is not often observed and is widely variable among bats. Frugivorous bats in Pteropodidae are more efficient climbers than frugivorous bats in Phyllostomidae and insectivorous bats in Vespertilionidae, while phyllostomids and vespertilionids are better at walking on horizontal surfaces. The aim of this study is to investigate whether bats with differing modes of nonflight locomotion also exhibit disparity in thoracolumbar vertebral morphology. Using geometric morphometrics, we compared the thoracolumbar vertebral shapes of these bat families with other terrestrial and arboreal mammals. The results revealed distinct vertebral shapes among bat families …