Life Sciences Commons^™

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 …

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 …

Population Structure And Connectivity Of Atlantic Nurse Sharks (Ginglymostoma Cirratum) In The Bahamas And Outlying Areas, Baylie A. Fadool

School of Natural Resources: Dissertations, Theses, and Student Research

Understanding animal ecosystem dynamics and behavior at the individual and population levels is essential for identifying life-history patterns and important areas for management and conservation. Marine fish species often face minimal geographic barriers to movement, but environmental (temperature, salinity, current) or intrinsic barriers (philopatry, site fidelity) can dictate gene flow. Atlantic nurse sharks (Ginglymostoma cirratum) are an International Union for Conservation of Nature (IUCN) listed ‘vulnerable’ species and present a unique opportunity to investigate patterns of population structure and connectivity in large-bodied sharks. They are benthic and display reproductive philopatry, with recent work suggesting they have the capacity …

Exploring Student Sensemaking During A Collaborative Biology Lab, Rebecca Kollipara

School of Natural Resources: Dissertations, Theses, and Student Research

Collaborative learning environments offer valuable opportunities for students to construct scientific understanding through dialogue, yet the conditions that support sustained conceptual reasoning in group settings remain incompletely understood. While prior research has identified discourse moves associated with productive collaboration, less attention has been paid to how those moves function together across turns and conceptual boundaries, or how individual student characteristics shape their emergence. This thesis examines collaborative sensemaking in an undergraduate General Biology II course, drawing on two complementary analyses of student discourse during a bryophyte life-cycle modeling activity.

Chapter 1 investigates how student groups participated in sensemaking and how …

Gaining Mussel: Evaluating Reintroduction Success Of Native Freshwater Mussels In Nebraska And Eastern Wyoming, Travis A. Moore

School of Natural Resources: Dissertations, Theses, and Student Research

Freshwater mussels are one of the most imperiled groups of organisms in North America, with over two-thirds of species considered threatened, endangered, or of special concern. These long-lived bivalves are essential to stream ecosystems, acting as filter feeders that improve water quality and as indicators of aquatic health. In Nebraska and Wyoming, native mussel populations have declined sharply due to habitat modification, pollution, and reduced connectivity. Two species of particular concern are the Plain Pocketbook Lampsilis cardium, listed as Tier I at-risk in Nebraska, and the Fatmucket Lampsilis siliquoidea, a Tier II at-risk species. In response, state agencies …

Honeybee Colony Response To Probiotic Supplementation And Grazing Practices, Katya M. Busenitz

Department of Entomology: Dissertations, Theses, and Student Research

Honeybee health is a complicated issue. Studies were conducted to scale honeybee (Apis mellifera) health from the microbiome to the landscape. Colony health parameters were measured in response to probiotic administration. Colony capped brood production, colony summer weight gain, and Varroa mite incidence were measured. I found that applications of over-the-counter probiotics did not improve the measured parameters of honeybee health compared to a control group. Results suggest that probiotic application was not beneficial but positive benefits may depend on application method, brand, or strain of probiotics used. I also examined how colony health metrics responded to different …

Assessment Of Super Absorbent Polymer In Soybean Cultivation Under Variable Irrigation Conditions In Nebraska, Ankit Chandra, Abia Katimbo, Ronaldo Marchezan, Martha Nabaggala

Department of Agricultural and Biological Systems Engineering: Presentations and White Papers

Water limitation is a primary constraint to soybean productivity in both irrigated and rainfed systems. Soil-applied superabsorbent polymers (SAPs) have been proposed as a strategy to buffer crops against episodic drought stress; however, their physiological and agronomic performance under varying irrigation regimes remains insufficiently quantified. Here, we evaluate three biodegradable polymer formulations: broader granules (BB), original granules (OG), and powder (PWR) applied at low (17.7 lb/ac) and high (120 lb/ac) rates under full (100% ET), reduced (50% ET), and no irrigation conditions in western Nebraska. Polymer application had negligible effects under full irrigation, with yields comparable to untreated controls. Under …

Passive Microwave Remote Sensing Of Flash Drought Impacts On Vegetation, Quinton R. Deppert

School of Natural Resources: Dissertations, Theses, and Student Research

In 2002, Dr. Mark Svoboda characterized a new form of drought known as flash drought. Flash drought was defined as a rapid decline in vegetation health caused by severe heat and drought. In recent years, attempts to quantify the impacts of flash drought via precipitation, soil moisture, evapotranspiration, and temperature indicators have proliferated. What has rarely been quantified is what the rapid decline in vegetation health amid flash drought looks like through remote sensing. This is because vegetation health indices like the Normalized Difference Vegetation Index (NDVI) are derived from the visible and infrared regions of the electromagnetic spectrum and …

Evaluating Management Strategies And Technology To Improve Grazing Efficiency, Thomas E. Aquino

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

Increasing land costs and labor constraints continue to challenge beef producers. More intensive practices can increase harvest efficiency; however, many producers are deterred from implementing them due to increased labor and management considerations. Virtual fencing (VF) may provide a reduced labor alternative to traditional fencing for managing intensive grazing. This dissertation evaluated management strategies and VF technology to improve grazing efficiency of stocker cattle systems. In Experiment 1, VF was used to effectively manage groups of steers grazing in adjacent paddocks separated by only virtual boundaries. There was no difference in VF containment (99%) when steers were grazing co-fenced, with …

Decomposition Study Using Pigs In Southeastern Nebraska During The Fall And Winter Seasons, Ryan Bodine

Department of Anthropology: Theses and Student Research

When an individual is found deceased, one of the tools used in the identification process is estimating the post-mortem interval (PMI). This estimate is used to determine how long an individual has been deceased once their remains are found. To estimate an accurate PMI, knowing how decomposition is affected by external factors is key. The transition period from fall to winter in southeastern Nebraska consists of fluctuating temperatures as the seasons transfer from fall to winter. This thesis investigates how decomposition is affected during this transition period while also looking at two different environments that are common in Nebraska, prairies …

Exploring The Biocultural Profile Of The Undocumented Populations Of The Sonoran Corridor: A Skeletal Assessment Of The Prevention Through Deterrence Strategy, Mary A. Vaughn

Department of Anthropology: Theses and Student Research

Over the last thirty years the mortality rate of the undocumented population at the US-Mexico border has risen, requiring methods distinguishing US-born individuals from immigrants to improve the likelihood of identification and repatriation through foreign consulates. Forensic anthropologists with the Pima County Office of the Medical Examiner (PCOME) have advocated for the use of the biocultural profile, combining the biological profile with factors including oral health, osteological stress, and personal effects. The biocultural profile serves two purposes, functioning both as a tool for identification and with which to document structural inequality within communities of origin.

This study examines changes in …

Evaluation Of Palm Oil As An Ingredient In Finishing Beef Cattle Diets On Performance, Carcass Characteristics, And Meat Quality, And The Composition Of Spayed Heifers To Intact Heifers Fed Melengestrol Acetate On Feedlot Performance And Carcass Characteristics, Tate S. Johnson

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

Heifers represent a large proportion of cattle placed in feedlots, making pregnancy management an important consideration for maintaining performance and carcass value. Melengestrol acetate (MGA) is commonly included in feedlot diets to suppress estrus and prevent pregnancy in intact heifers during the finishing period. Alternatively, spaying has historically been utilized as a management practice to allow heifers to graze alongside breeding cattle without the risk of pregnancy. Despite its historical use, there is limited contemporary research comparing the growth performance and carcass characteristics of spayed heifers with intact heifers managed with MGA under modern feedlot conditions. Therefore, a commercial study …

Advancing Targeted Food Allergen Detection: Extraction Optimization And Sample Preparation Method Comparison Using Lc-Ms/Ms, Zhenhao Wang

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Accurate quantification of food allergens in processed foods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) requires effective protein extraction and sample cleanup. However, no single sample preparation workflow has shown consistent performance across diverse food matrices. This study evaluated extraction buffer formulations and post-extraction cleanup strategies for quantification of milk, soy, and peanut allergens in multiple processed food matrices.

Six extraction buffers with varying combinations of SDS, urea, and thiourea alongside a common Tris-HCl/DTT/PVPP base were evaluated across five food matrices. No significant differences in extraction efficiency were observed among buffer formulations for nonfat dry milk (NFDM), non-roasted soy flour, peanut …

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 …

Effects Of Applying Humic Acid In-Furrow At Potato Planting, Jonathan Tyler Price

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

Many products are marketed towards potato farmers that purport to have a positive return on investment for yield and quality. Humic acids, which are comprised of long chained, organic molecules that can be naturally or industrially made, are currently being marketed in this way. The use of these materials is reported to improve nutrient uptake, increase soil health, encourage vigorous growth, and most importantly, increase yields.  From 2023-2025, the in-furrow application of humic acid containing commercial products was evaluated in Pennsylvania on the cultivars ‘Lehigh’ and ‘Waneta’. Black Label Zn, Duo Maxx, Fertiactyl RhiZn, Humi-flex FA, Hydra-Hume, and Monty's Liquid …

Evaluating The Impact Of Intercropping Vegetables And Cut Flowers On Yield And Conservation Biological Control, Alliance Igiraneza

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

Specialty crops such as vegetables are some of the most susceptible to yield losses and increased management difficulty over time due to pests. One of the potential solutions to this problem, which aims at ensuring the sustainability of the sector, is using conservation biological control practices such as intercropping to increase diversity, while maintaining the economic feasibility and profitability of the system. This study was conducted to evaluate the impact of this management practice using Bell pepper (Capsicum annuum var. King Arthur) as the main crop, intercropped with flowers including zinnia (Zinnia elegans var. Benary’s Giant), sunflower ( …

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, …

Breeding For Diverse Color And Protein Quality In Popcorn And Sweet Corn, Jonathan Niyorukundo

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

Sweet corn and popcorn are important crops consumed globally as vegetable and snack, respectively. They are deemed healthy foods due to high fiber and carotenoid contents, especially in yellow varieties. Commercial varieties are optimized for high-yielding agronomics, and previous efforts were made to improve specific macro- and micronutrient contents. Both sweet corn and popcorn have poor protein quality due to the inadequate essential amino acids such as lysine and tryptophan. Moreover, commercial varieties are predominantly yellow, thereby offering no diversity of other maize colors, which are potentially healthier and more appealing to the consumer. In this project, we sought to …

Impacts Of Supplemental Fat In Finishing Diets On Digestibility, Performance, Carcass Outcomes, Meat Quality And Methane Production Of Feedlot Cattle, Anna Marie Kobza

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

Rising costs and fluctuating availability of supplemental fats has led to increased interest in alternative fat sources or feed additives that might improve utilization of supplemental fat in feedlot diets. Two separate experiments were conducted to evaluate alternative strategies to overcome high fat prices. The first experiment was a metabolism study, conducted to evaluate digestion parameters of supplemental fat sources with or without LYSOFORTE Extend. The objectives of this experiment were to evaluate LYSOFORTE Extend in beef finishing diets containing a saturated fat source (tallow) and unsaturated fat source (corn oil). Duodenally and ruminally fistulated steers were fed diets containing …

Program And Proceedings, The Nebraska Academy Of Sciences 1880–2026: 146th Anniversary Year, One Hundred-Thirty-Sixth Annual Meeting

Nebraska Academy of Sciences: Programs and Proceedings

Program and abstracts of the proceedings for the Nebraska Academy of Sciences 136th annual meeting, 2025

Sessions

Aeronautics and Space Science

Anthropology

Biological and Medical Sciences

Earth Sciences

Ecology, Sustainability, and Environmental Science

Physics and Engineering

General Poster Session

2026 Maiben Lecture: Shifting Extremes: Understanding Nebraska’s Changing Climate and Preparing for What Lies Ahead, Deborah Bathke

2026 Friends of Science Awards: Julie Shaffer and Irina Filina

2026 C. Bertrand and Marian Othmer Schultz Colleaguate Schoalrship Award: Piper Ryschon and Bryce Reeson

In Memoriam: Paul Royster

On The Transport Of Chloroplast Lipids, Cailin Smith

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

Chloroplasts are green, photosynthetically active organelles ubiquitous to the plant kingdom. Owing to their cyanobacterial origin, chloroplasts consist of three membranes: the outer envelope, the inner envelope, and the thylakoid, the latter of which is the site of the light-dependent reactions of photosynthesis. Not only do the lipids that make up these membranes delineate aqueous compartments, but they also respond dynamically to developmental and environmental cues, constitute the matrix that scaffolds protein machinery, and even serve as functional components of some proteinaceous complexes. However, while lipids are of vital importance to the structure and function of the chloroplast, the mechanisms …

The Impact Of State And Federal Policies On Academic Researchers: Findings From A National Survey, Dylan Ruediger, Chelsea Mccracken, Jonathan Barefield

Copyright, Fair Use, Scholarly Communication, etc.

Key findings

● State and federal policies targeting divisive concepts or DEI are shaping research agendas at scale and across disciplines. Twenty percent of all respondents, and 29 percent of researchers working in states with divisive concepts or similar laws, reported having avoided certain research topics because of state laws and policies.

● Eight percent of respondents representing a wide range of disciplines reported having had a federal grant cancelled in 2025.

● Eleven percent of respondents reported that federal and state policies restricting research activities are compelling them to seek employment out of state, to leave the academy, or …