Digital Commons Network^™

Contrasting Roles Of Downed Wood And Leaf Litter In Structuring Aphaenogaster Ants And Other Forest-Floor Arthropod Communities, Danielle E. Dolan

Great Lakes Center Masters Theses

Forest floors are dynamic and spatially heterogenous landscapes characterized by differing amounts of light, temperature, and moisture. Bounded substrates, like downed wood and leaf litter, add further complexity to this landscape. Specifically, downed wood is noted for its ability to retain a higher moisture level than the surrounding environment, and as such can serve as an ideal microhabitat for desiccation intolerant organisms (e.g., salamanders and eusocial insects). Here, I attempt to disentangle the relationship between forest floor arthropods and microhabitat selection (i.e., downed wood vs leaf litter) on a northeastern forest floor. The ant, Aphaenogaster picea, was chosen as my …

Differential Salinity Tolerance And Compositional Shift In Zooplankton Communities From Coastal And Inland Wetlands, Marisa Contreras

Theses, Dissertations and Culminating Projects

Anthropogenic salinization from road salt application has degraded freshwater ecosystems across the United States, yet the tolerance of freshwater communities to elevated salinity may depend on their historical exposure. Coastal systems experience natural salt intrusion through tides and storm events, potentially fostering greater salinity tolerance amongst resident organisms, while inland systems lack this exposure history. To investigate, I studied the abiotic and biotic responses of zooplankton communities from four wetlands across a salinity gradient to assess tolerance to experimental salt exposure. Two inland freshwater wetlands are subject to anthropogenic salinization from road salt runoff, while two coastal wetlands experience natural …

Improving Genomic Prediction For Feed Efficiency Traits In Beef Cattle Using Microbiome As An Intermediate Omics, Egodage Bhagya Sewwandi Samarakoon

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

Feed efficiency traits, including feed conversion ratio (FCR), average daily gain (ADG), and average daily dry matter intake (ADDMI), are economically important in beef cattle production. Emerging evidence suggests that host genetics influences feed efficiency traits through the microbiome. This study evaluates the integration of microbiome data as an intermediate layer in the Neural Network Mixed Model (NNMM), which hierarchically models genotype–microbiome–phenotype relationships as a unified regulatory network to improve genomic prediction accuracy. To reduce the computational burden of NNMM, microbiome features dimension were reduced using principal component analysis (PCA) and direct feature selection of top-ranked open reading frames (ORFs) …

Carcass Mass And Cooling Dynamics As Determinants Of Beef Color, Tenderness, And Dark-Cutting Risk, Grace C. Johnson

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

Discoloration in beef has important implications to the beef industry. Dark-cutting (DC) beef remains one of the most economically significant color defects; however, industry prevalence has only marginally declined (≈ 0.1%) despite mitigation efforts. This lack of improvement largely stems from research focused on pre-harvest stress and glycogen depletion leading to dark, firm, and dry (DFD) beef. However, not all darkcutting beef originates from DFD phenotypes. Atypical dark-cutting (ATDC) phenotypes have recently been observed and do not exhibit the classic metabolic indicators of DFD. This trend coincides with steadily increasing carcass weights in the beef industry and raises the possibility …

From Prairie To Practice: Forensic Taphonomy, Ethics, And Regional Ecology In Southeastern Nebraska, Jessica F. L. Gammage

Department of Anthropology: Theses and Student Research

Forensic taphonomy examines the postmortem processes that affect human remains within specific environmental contexts and plays a critical role in medicolegal death investigation. Despite significant advances in decomposition research, experimental studies remain geographically and environmentally uneven, limiting the transferability of postmortem interval (PMI) estimation methods across regions. The Central Great Plains are underrepresented in forensic taphonomic research despite its distinct ecological and geomorphological characteristics.

This thesis evaluates southeastern Nebraska as a specific regional setting for forensic taphonomic research by integrating ecological, pedological, and geomorphological data with current forensic literature. Tallgrass prairie vegetation, loess-derived soils, seasonal moisture variability, and dynamic fluvial …

Understanding Roma Oppression In Europe Through Humantarian Forensic Analysis, Christal L. Quinn

Department of Anthropology: Theses and Student Research

This thesis examines the marginalization of Roma people in Europe, and how humanitarian forensic practices may help Roma communities in their quest for justice and recognition. The study draws exclusively on secondary information to examine the social, political, and legal issues affecting the Roma communities, who have endured centuries of institutional discrimination, marginalization, and violence. This thesis identifies ways in which systematic oppression continues to limit Roma communities’ access to education, housing, healthcare, and legal protection through a review of relevant literature and applicable theoretical frameworks. The study also examines the relevance of forensic science, particularly its humanitarian applications, in …

Rehumanizing Anatomized Individuals: Using Osteobiographies As A Step Towards Reparative Justice, Lillie C. Turpin

Department of Anthropology: Theses and Student Research

In 1985, India banned the export of human remains. This ended the major trade route for primarily US and European anatomical supply companies. Until this point, companies like Carolina Biological Supply exploited and erased vulnerable people's identities, molding them into anonymous anatomical specimens. This study investigates the life and postmortem history of twenty-five individuals, previously used as anatomical specimens, housed at the University of Nebraska–Lincoln. Using an osteobiographical approach, this research reconstructs aspects of these individuals' lived experiences and examines how anatomical preparation practices reflect structural violence and apathy.

Skeletal analysis of twenty-five individuals revealed a range of biological profiles, …

Non-Destructive Automated Classification Of Human And Large Mammal Long Bone Fragments: A Deep Learning Approach Using Micro-Ct Histomorphology And Grad-Cam Interpretation, Kathleen Marie Kelley

Department of Anthropology: Theses and Student Research

This study explores the development and validation of an automated, deep learning system designed to differentiate human from large mammal long bone fragments using micro-CT imagery. A comprehensive dataset of cross-sectional µCT images was assembled from human and animal skeletal material processed at the DPAA, Nebraska. A convolutional neural network (CNN) based on a ResNet-18 architecture, utilizing transfer learning from ImageNet weights, was trained to classify µCT images as human or animal. The model achieved a mean classification accuracy of 89.85% (± 8.27%) across five sample-level cross-validation folds, with a sensitivity of 96.21% and a 95% bootstrap confidence interval of …

Monitoring Biodiversity Growth In An Oyster Reef Restoration: Understanding How Oyster Reef Life Cycle May Impact Biodiversity., Gabriel A. Roses

Theses and Dissertations

Oyster reefs are vital to marine ecosystem health, improving water quality and providing food and habitat for diverse species. We assessed biodiversity changes for a proposed oyster reef restoration site to help guide management, future assessment, and deepen understanding of how oyster reefs function and their ecosystems dynamics.

Bugs, Birds, Blue: Queer Ecologies Of Embodiment, Kinship, And Survival, Celeste B. Newcomb

Theses and Dissertations

bugs, birds, blue is a multi-channel audiovisual installation that examines queer ecology as a framework for understanding transgender embodiment, kinship, and survival amid environmental crisis and ongoing political attacks on trans life (Mortimer-Sandilands and Erickson). Through sculpture, projection, sound, reflective surfaces, and biological imagery, the installation places human bodily matter alongside microbial and aquatic life forms to challenge narratives that frame trans existence as unnatural, recent, or isolated. Instead, the work proposes transness as relational, adaptive, and deeply entangled with broader ecological systems. The installation is composed of two interconnected environments. On one side of the space, three aquariums rest …

Genetic Screen For Regulators Of Pol4, A Dna Repair Polymerase In Saccharomyces Cerevisiae, Pasang Dolma Sherpa

Theses and Dissertations

In Saccharomyces cerevisiae, DNA polymerase 4 (POL4) is the beta repair polymerase, the product of the POL4 gene, and is involved in base excision repair (BER) and microhomology-mediated end joining (MMEJ). Despite its involvement in these repair pathways and its conservation across eukaryotes, deletion of POL4 shows no detectable phenotype under standard laboratory conditions. I hypothesized that unknown genes act as backup systems, providing redundant activities that allow pol4Δ cells to survive. To test this, a genetic screen for mutants showing synthetic lethality with pol4Δ was implemented. I constructed a strain lacking the POL4 gene and carrying …

Effects Of Vitamin E Deficiency On Anxiety-Like Behavior In Zebrafish With Distinct Stress Coping Styles, Areem Zahid

Theses/Capstones/Creative Projects

Stress and anxiety disorders affect millions worldwide and represent a significant public health burden. Individual differences in stress coping style and antioxidant regulation contribute to variability in stress responsiveness and anxiety-related behaviors. Oxidative imbalance has been implicated in the neurobiology of anxiety, but its interaction with inherent stress coping phenotypes remains unclear. This study examined whether long-term dietary vitamin E deficiency alters anxiety-like behaviors in zebrafish selectively bred for proactive and reactive stress coping styles. Adult zebrafish were maintained on either a vitamin E–sufficient or vitamin E–deficient diet for five months, followed by behavioral assessment using the novel tank diving …

Trawling For Clues: Examining Nefmc Herring Amendment 8, Christopher Santoro

Honors Scholar Theses

In 2007, almost twenty years ago, the Magnuson-Stevens Act changed the landscape of fisheries management in the US. Through the establishment of Fisheries Management Councils (FMCs), it paved the way for top-down management approaches that helped the government combat nationwide declines or collapses in fish stocks. Among the myriad responsibilities of the FMCs was the expectation that amendments to existing fisheries management plans would be a necessity to adapt to modern circumstances. This thesis focuses on New England Fisheries Management Council's (NEFMC's) Herring Amendment 8 (A8). This amendment, passed in 2021, attempts to lay the groundwork for sustainable management of …

Unveiling The Biochemical Pathway Responsible For Ankyloglossia (Tongue-Tie) By Tracking Enzymatic Activity Of Apoptosis Pathways, Becca Ringstad

Celebrating Scholarship and Creativity Day (2018-)

Ankyloglossia (Tongue-tie) is a condition that is caused by failed cellular degeneration leading to a short lingual frenulum. This short lingual frenulum tethers the tongue to the bottom palate of the mouth and leads to problems, including breastfeeding for infants, depriving them of important proteins that build the gut microbiome, strengthen the immune system, and fight off antigens. If left untreated, it leads to problems with speech articulation, airway development, and obstructive sleep apnea. Treatment involves a frenectomy, which is the release of the short lingual frenulum using surgical scissors or a laser. Ankyloglossia can occur with conditions such as …

Cancer Gets Extreme: How Extremophiles Can Improve Research And Therapy, Jason Malmgren

Celebrating Scholarship and Creativity Day (2018-)

Extremophiles are organisms that can survive in extreme environmental conditions, and their unique biological adaptations have gained attention for potential applications in cancer research. This paper explores how the molecular characteristics of extremophiles, such as enhanced DNA repair, resistance to oxidative stress, and structural stability, may be useful in improving cancer treatment strategies. A range of studies were examined to understand both direct and indirect roles of extremophile-derived compounds in oncology. Some research shows that compounds from organisms like Deinococcus radiodurans and extremophilic Streptomyces species can inhibit cancer cell growth, increase reactive oxygen species, and trigger apoptosis. Other studies highlight …

Lipid Deposition In Beef Cattle, Kyra L. Elliott

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

Both the amount and types of lipid deposition in beef cattle are key determinants of carcass value and meat quality. Amounts of intramuscular, subcutaneous, and visceral fat influence carcass grading outcomes, palatability, and composition traits that are important to beef producers as well as consumers. The objectives of this thesis were to: 1) compare beef grading camera estimates of intramuscular fat to amounts of chemically extractable lipid, 2) characterize the lipidomes of beef intramuscular fat, subcutaneous fat, and lean muscle using shotgun lipidomics, and 3) identify and characterize a novel genetic variant in cattle that may have important implications for …

Characterization Of Activity Changes In Gilts During Estrus Using The NuTrack Livestock Monitoring System, Emily P. Aquino

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

Early and accurate detection of estrus in replacement gilts is essential for reproductive success and to ensure efficient production. The objective of this study was to evaluate activity changes occurring relative to first estrus of gilts and subsequent cycles. At ~ 110 days of age, 112 gilts were randomly assigned to 14 pens and placed under continuous video monitoring until the end of the trial at ~ 200 days of age. Daily boar exposure (~ 10 minutes per day) began at ~ 122 days of age. During this period, recorded observations included vulva scores (based on swelling and redness), mounting …

Evaluation Of Maternal Bovine Appeasing Substance Administration And Feed Access Time On Finishing Cattle Performance, Behavior, And Carcass Characteristics, Carsten L. Loseke

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

Novel products and bunk management techniques may significantly influence economically relevant performance metrics of feedlot cattle. The objective of the first experiment was to evaluate maternal Bovine Appeasing Substance (mBAS) administration on performance, carcass, health, and cortisol outcomes of yearling steers. Steers (n = 1,754, initial BW = 423 kg, SD = 25 kg) were received and assigned to pens for treatment allocation. Steers received either 10 mL of the mBAS or a mineral oil placebo at initial processing and reimplant. Hair samples were collected from a subset (n = 4 steers/pen) on d 0 and d 14. …

Integrating Growth Performance And Pathogen Detection To Investigate Disease Resilience In Commercial Swine, Emmalise Hope Marie Meyer

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

Disease resilience is an important trait in commercial swine production, influencing both animal health and growth performance under natural disease challenge. The primary objective of this study was to integrate growth performance data with longitudinal pathogen detection to better understand factors contributing to disease resilience in commercial pigs. A population of 1,014 pigs across four batches was monitored from weaning through the grow-finish phase, with body weights collected to calculate average daily gain (ADG). Genome-wide association analyses were conducted using BayesC and BayesIM approaches to identify genomic regions associated with growth performance. Longitudinal pathogen surveillance was performed using pen-level oral …

Tail Biting In The Nursery: Evaluating Postural, Spatial, And Behavioral Differences Between Tail Biter And Victim Pigs, Storey L. Forster

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

This study examined behavioral differences among pigs classified as tail biters, victims, or neutral during the nursery period. A total of 192 undocked nursery pigs were assigned to eight pens and monitored for 30 days using the NUtrack system. Tail biting events were identified from video observations, and pigs contributing to the top 25% of observed tail biting activity were classified as tail biters. Based on weekly tail scoring, pigs assigned a maximum tail injury score ≥ 2 were classified as victims. All other pigs were considered neutral. A total of 700 tail biting events were observed. Thirty-eight pigs …

Application Of High-Pressure Processing To Improve The Color Of Dark Beef, Kara Ann Reynolds

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

Deviation of beef from the bright cherry-red color preferred by consumers is often discounted or discarded at retail, resulting in substantial annual economic loss to the beef industry. One such deviation is dark cutting beef, which is characterized by a darker lean appearance that is undesirable to consumers and often rejected. Similarly, beef from mature cattle tends to exhibit a darker surface color, which can also reduce consumer acceptability. High-Pressure processing (HPP) has been investigated as a strategy to improve the color of dark cutting beef. Previous studies have focused on identifying pressure levels and holding times that optimize color …

Preclinical Animal Modeling To Investigate Redox-Mediated Molecular Dysfunction In Traumatic Brain Injury, Brandon Z. Mcdonald

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Impacts associated with traumatic brain injury (TBI) induce a multitude of neurological morbidities mediated by a spread of biochemical dysfunction. Redox stress is a significant contributor to TBI pathophysiology and several redox stress markers have substantial evidence to support their role in diagnosing preclinical and clinical TBI. However, there is a critical need to verify their translational utility through correlations with behavioral, imaging, and molecular modalities. In chapter two, we examined the therapeutic efficacy of an antioxidant treatment (NPC3) using a controlled cortical impact (CCI) mouse model of TBI. NPC3 alleviated glial expression and reactivity while influencing the expression of …

Factors Affecting The Efficacy Of Free Choice Vitamin & Mineral Supplementation Programs, Tanner K. Wansing

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

While free choice vitamin and mineral supplements are widely used within the cow/calf sector, large knowledge gaps exist around the proper management of those supplements. This thesis discusses two factors affecting the efficacy of supplementation. The first interest was the stability of vitamin A when stored with a common free choice mineral supplement. This research addressed a critical data gap by generating information on vitamin A stability within the beef industry, as current data are predominantly based in the swine industry. Vitamin A was discovered to be stable until 4 months of storage regardless of storage conditions, whereas after 4 …

Cytoplasmic Shift Of Interferon Regulatory Factors Co‐Evolved With Jawed Vertebrate Innate Immunity, Vanessa M. Hubing

Honors Program: Senior Projects (Public)

The emergence of jaws in early vertebrates introduced a novel feeding apparatus and powerful oral defenses, but it also increased the risk of physical injury and pathogen exposure. Interferon regulatory factors (IRFs) play critical roles in orches-trating innate immunity and inflammation in response to invading microbes and tissue damage, with their subcellular local-ization being essential to some IRFs' function. Our results indicate that IRF members underwent independent expansion and diversification in two distinct vertebrate lineages: jawed and jawless vertebrates. The jawed vertebrate-specific factor, IRF5, has maintained conserved nuclear export sequences throughout evolution, while newly diversified IRF members in jawed verte-brates …

Geospatial Science And The Changing Environment: Applied Methods For Sustainable Agriculture And Landscape Management, Harrison Wakefield Smith

Graduate Theses and Dissertations

Rapid environmental change is disrupting agricultural productivity, ecological function, and the long-term resilience of managed landscapes. At the same time, the rapid growth of geospatial data science has improved our understanding of environmental change and increasingly is being used to improve sustainability in agricultural and environmental management. However, critical gaps remain that limit the applicability of data-driven insights in landscape management. This dissertation investigates the potential of geospatial analytics for sustainable agriculture and landscape management, with a focus on applied methods that operate across spatial and temporal scales. Using field, landscape, regional, and national datasets, it explores the capabilities and …

Genome-Wide Phenotypic Characterization Of Mycobacteriophage Mercurio, Tyler Downs

Departmental Honors & Graduate Capstone Projects

Bacteriophages, or phages, are being piloted as a supplemental or alternative therapeutic to antibiotics against drug-resistant Mycobacterium pathogens, such as M. tuberculosis, which pose a global public health crisis.  Characterizing bacteriophage genomes can provide insights into efficacy in phage therapy before implementation or elucidate new targets to manipulate bacterial growth.  Overexpression of individual phage genes is useful to study a gene product’s function independent of others.  Here, the results of phage Mercurio plasmid library overexpression in plate-based assays are described.  Mercurio infects nonpathogenic Mycobacterium smegmatis and is genetically related to bacteriophages infecting pathogenic Mycobacterium species.  Eleven gene products of …

Aggregation And Collation Of Texas Crayfish Museum Specimens To Determine Their Current Conservation Statuses, Adrian Alvarez

Biology Theses

Crayfish account for over half of the macroinvertebrate biomass in many ecosystems and serve as crucial bioindicators because of their behavioral and physiological adaptability to environmental changes. Despite being home to approximately 52 native crayfish species, Texas currently lacks protective regulations. This gap is primarily because of insufficient information regarding their distribution and occurrences within the state, including their statuses as Species of Greatest Conservation Need (SGCN). This study focuses on compiling and comparing crayfish museum records with current iNaturalist field survey data across Texas to address these knowledge gaps and recommend updates to SGCN statuses. Five species not currently …

Cis-Variant Gene-Expression Association Analysis: A Targeted Approach To Identify Functional Cis-Regulatory Variation, Sofiya Arora

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Phenotypic diversity in plants is largely driven by changes in gene function arising from mutations in both the coding and regulatory regions. Regulatory variation is particularly pervasive because it can fine-tune gene expression without disrupting protein function and is therefore less likely to be strongly selected against in natural populations. As a result, it has played a central role in evolution and domestication. In our previous genome-wide eQTL mapping study in maize, nearly two-thirds of the expressed genes were found to harbor detectable cis-expression quantitative trait loci (cis-eQTLs) with strong local effects on gene expression. Though these cis-variants are widespread, …

Quantitative Genetics, Genomics, And Phenomics In Maize And Sorghum, Nikee Shrestha

Complex Biosystems Program: Dissertations and Student Research

Generating the best crop varieties and hybrids requires identifying genes associated with the phenotype of interest and screening thousands of varieties across multiple locations. Quantitative genetics, along with comparative genomics, phenomics, and machine learning approaches, can help us identify target genes associated with the phenotype of interest to develop the right genotypes. Satellite platforms offer logistical and technical advantages in scalability and accessibility and could facilitate plot-level predictions, especially with steadily improving spatial resolution, thereby empowering the large-scale screening of thousands of genotypes across diverse locations. In the first chapter, I evaluated over 20,000 plot-level images of over 80 hybrid …

Fisheries Management Paper No. 313: Western Australian Statewide Small Pelagic Scalefish Resource Harvest Strategy, Department Of Primary Industries And Regional Development, Western Australia

Fisheries Management Papers

Harvest strategies for Western Australia’s (WA) aquatic resources are formal documents developed by the Department of Primary Industries and Regional Development (DPIRD, the Department) to support decision-making processes that ensure the outcomes are consistent with the principles of Ecologically Sustainable Development (ESD; Fletcher 2002a) and Ecosystem Based Fisheries Management (EBFM; Fletcher et al. 2012).

Harvest strategies are a key component of all contemporary fishery management systems and a requirement for certification under the Marine Stewardship Council (MSC; Marine Stewardship Council 2018). The objectives of ESD are reflected in the objects of the Fish Resources Management Act 1994 (FRMA).

This Statewide …