Life Sciences Commons^™

Transforming Grassland Conservation: Challenges And Opportunities Across Law, Policy, And Human Dimensions, Conor D. Barnes

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

Great Plains social-ecological systems are facing growing pressure from complex, ‘wicked’ problems. Addressing these problems will require integrating ecological resilience and complex systems thinking concepts into our legal framework in order to better reflect the changing ecological reality of the Great Plains and promote flexibility and adaptability in the face of that change. In this dissertation, I examine how past and present policy priorities have affected social-ecological systems on the Great Plains, and how ecological resilience and complex systems thinking might be applied to grassland management policy. In Chapter 2, I examine the rapid progress made in the adoption of …

Role Of The Malate Dehydrogenase-Citrate Synthase Metabolon In Metabolic Flux Regulation, Joy John Omini

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

The TCA cycle enzymes- malate dehydrogenase (MDH) and citrate synthase (CS)- interact to transfer oxaloacetate from the active site of MDH to the active site of CS, through an electropositive channel. The MDH-CS metabolon is highly conserved across different domains of life, and it has been associated with many advantages. Some of these advantages include protecting oxaloacetate from competing enzymes like aspartate aminotransferase, allowing the thermodynamically unfavorable MDH forward reaction to occur and increasing the local concentration of oxaloacetate within the active site of CS. These advantages and conservativeness of the MDH-CS metabolon indicate that it is highly important to …

The Effects Of Anchor Scheme On The Central And Peripheral Contributions To Performance Fatigability, Perceived Responses And Sensations, And Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks To Failure, Robert Walker Smith

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

The Effects of Anchor Scheme on the Central and Peripheral Contributions to Performance Fatigability, Perceived Responses and Sensations, and Psychological Factors Following Sustained, Isometric Forearm Flexion Tasks to Failure Robert W. Smith, Ph.D. University of Nebraska, 2024 Advisor: Terry J. Housh This study assessed time to task failure (TTF), performance fatigability (PF), neuromuscular responses, central and peripheral measures of fatigue, and perceived responses including sensations and psychological factors that contributed to task termination during sustained, isometric forearm flexion tasks anchored to ratings of perceived exertion (RPE) and the torque corresponding to RPE. Fifteen men (age = 21.5 ± 2.3 yrs; …

Phylogenetic And Biogeographic Patterns Of Devonian Proetid Trilobites, Katherine Jane Jordan

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

Ecological disruption events such as mass extinctions can result in the permanent alteration in clades and ecosystems. A pivotal time of change during the history of life on Earth can be seen in the Devonian Period. During this time, major transitions in marine and terrestrial system resulted in a different world at the end of the period in comparison to the beginning. One such group most heavily impacted were trilobites. Trilobites were reduced to one order by the end of the Devonian: Proetida. My dissertation focuses on phylogenetic, biogeographic, and paleocommunity patterns of this group, known as the last of …

Development Of An Egg-Specific Mass Spectrometry Targeted Method For Processed Food Matrices, Liyun Zhang

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

Egg is a major food allergen in the United States, causing symptoms from mild reactions to severe anaphylaxis. An egg-free diet remains the only management approach for egg allergy. Therefore, individuals and families living with egg allergies rely heavily on allergen statements on packaged food products for informed food choices. Currently, no labeling regulations exist for unintentionally introduced allergens, posing risks to consumers with egg allergies. Therefore, it is critical to have an accurate and reliable detection method in allergen control and management to determine the concentration of total protein from allergenic food sources. Traditional enzyme-linked immunosorbent assays are routinely …

A Data-Driven Discovery System For Studying Extracellular Microrna Sorting And Rna-Protein Interactions, Sasan Azizian

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

Interactions between microRNAs (miRNAs) and RNA-binding proteins (RBPs) are pivotal in miRNA-mediated sorting, yet the molecular mechanisms underlying these interactions remain largely understudied. Few miRNA-binding proteins have been verified, typically requiring extensive laboratory work. This study introduces DeepMiRBP, a novel hybrid deep learning model designed to predict microRNA-binding proteins. The model integrates Bidirectional Long Short-Term Memory (Bi-LSTM) networks with attention mechanisms, transfer learning, and cosine similarity to offer a robust computational approach for inferring miRNA-protein interactions.

DeepMiRBP is implemented through two distinct architectures. The first architecture employs a Y-shaped model that uses Bi-LSTM networks and transfer learning to extract contextual …

Understanding The Role Of The Microbiome In Infectious Disease, Developing Surveillance Tools, And Engineering Direct Fed Microbials To Improve Animal Health, Alison Clare (Bartenslager) Neujahr

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

With the ever-increasing demand for animal protein and the continual need for the assurance of proper animal welfare, investigations of preventative strategies for diseases is greatly needed. Specifically in the cattle industry, infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, causes a large economic loss to the producer. However, effective mitigation strategies are lacking. Partly, this is due to the lack of studies investigating the ocular microbiome. Therefore, studies investigating the bovine ocular microbiome are greatly needed to better understand IBK disease etiology. To this end, we investigated the changes in the ocular microbiome in animals before, during and after …

Preschool Executive Control And Adolescent Dietary Outcomes: Highlighting The Role Of Context, Marla Lopez

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

Research has identified executive control (EC) as an important predictor of dietary outcomes among youth. Executive control in preschool age has been shown to predict important outcomes across development for youth, indicating that good, foundational EC abilities are associated with successful development in later life. Dietary outcomes across adolescence, an important transitional period for establishing healthy eating behaviors, are understudied. Therefore, the current study sought to link two critical developmental periods, examining how preschool EC is associated with dietary trajectories across adolescence. Further, the study aimed to identify how contextual factors, specifically indices of socio-economic status and the home and …

Candida Albicans Farnesol Synthesis And Secretion, Daniel John Gutzmann

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

Candida albicans is a polymorphic fungus and opportunistic commensal found primarily in the gastrointestinal and skin of healthy individuals. Several barriers prevent C. albicans from causing disease including a healthy immune system and microbiome. When these barriers become comprised, C. albicans can transition to a pathogen and disseminate through the intestinal mucosa leading to life-threatening bloodstream and invasive infections with mortality rates of up to 64%. Morphogenic plasticity is key to this transition and impacts virulence, adaptation to different host environments, and evasion of host immune responses. One regulator of morphogenesis is farnesol. Farnesol is a secondary metabolite …

Investigating Associations Between Activity And Performance Traits Across Three Breeds Of Swine Using NuTrack, Dalton R. Obermier

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

Feed costs are the largest contributor towards the variable costs of pork production. To decrease feed cost while not sacrificing output requires an improvement in feed efficiency (FE). A potential approach to expand available phenotypes associated with FE is with activity tracking, yet the relationship between activity and performance is not well defined in swine. Therefore, the objective of this study was to quantify associations between activity and feed intake traits. Average daily feed intake (ADFI) was collected on 1,766 purebred boars of three genetic lines (Duroc, Landrace, and Yorkshire) using FIRE (Osborne Industries, Inc., Osborne, KS) at a testing …

Integrating Water And Nitrogen Management For Sustainable Agriculture: Optimizing Resource Use Efficiency And Maximizing Crop Productivity, Jiaming Duan

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

Advisors: Derek Heeren and Daran Rudnick Maize, accounting for over 95% of national grain production in the United States, is highly sensitive to water and nitrogen (N) inputs. Conventional agricultural practices often lead to excessive application, causing groundwater contamination through nitrate leaching. Therefore, there is a demand for integrating water and nitrogen management with innovative scheduling methods for sustainable agricultural development.

This dissertation first reviewed two decades of U.S.-based research, highlighting the optimal management of water and N to enhance yield, water use efficiency (WUE), and nitrogen use efficiency (NUE). Findings indicate that maintaining optimal levels of N and water …

Dynamics Of Soybean Seed Protein And Oil Content With Depth In The Canopy, Hafith Furqoni

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

Understanding the physiological basis of variation in seed composition is critical for optimizing soybean seed composition. Also, studying dry matter accumulation and nitrogen uptake, partitioning, and redistribution in soybeans is crucial due to its direct impact on seed yield levels and overall plant productivity. This study aimed to test the primary proxy influencing seed protein and oil content, which is their accumulation rate determined by the assimilate supply per seed. The second objective was to comprehensively understand soybean dry matter (DM) accumulation and nitrogen (N) uptake, partitioning, and removal patterns within the canopy. Field experiments were conducted using two soybean …

Manipulations Of The Caenorhabditis Elegans Microbiome Reveal Influences Of Detrimental Members On Host Life History Traits, Ashley Elizabeth Foltz

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

Microbiomes are a fundamental part of eukaryotic organisms and play a role in both host health and fitness. Although microbiomes are often associated with health and positive effects on the host, certain microbiome compositions are also associated with disease. We used Caenorhabditis elegans and its experimental microbiome, CeMbio to explore the interactions that individual microbiome members have with other microbes, with the host, and how the entire microbiome community interacts with the host. We found that individual CeMbio members have varying effects on host health and fitness compared to the whole community. This suggested that there is synergy occurring in …

Spatial Ecology Of Mountain Lions Throughout Their Distribution In California, Kyle Duncan Dougherty

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

Mountain lions (Puma concolor) have been studied extensively throughout their wide geographic distribution in the Western Hemisphere, but most research has been conducted at relatively small spatial scales. We used GPS telemetry data contributed by researchers in 16 study areas throughout California to advance understanding of mountain lion spatial ecology. First, we investigated multi-scale resource selection of mountain lions relative to spatially varying risk of intentional human-caused mortality associated with livestock depredation management. We show that individuals that proactively avoided mortality risk when selecting home ranges were able to relax their avoidance of risk when making resource selection …

Development Of A Durable And Low-Dose Universal Vaccine Against Swine Influenza A Virus, Erika Petro-Turnquist

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

Swine Influenza A Virus (IAV-S) imposes a significant burden on the pork industry and poses a great threat to public health due to its zoonotic potential. Susceptibility to human, avian, and swine influenza make pigs the ultimate mixing vessels for reassorted influenza A virus strains. Current vaccination strategies induce short-lived and strain-specific responses against IAV-S. Further, the substantial genetic diversity of IAV-S necessitates consistent revaccination and updating of commercial vaccines. Computational platforms have recently emerged as a promising strategy to develop new-age vaccines against infectious diseases in livestock animals. Here, we describe a computationally derived set of vaccine immunogens, called …

Heat Stress Changes The Bovine Methylome And Transcriptome And Investigation Of Two Novel Genetic Defects In Cattle, Rachel Renae Reith

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

Heat stress is a major concern for livestock producers due to its negative impact on animal health and productivity. Heat stress does so by altering expression of genes through different regulatory mechanisms such as DNA methylation. Understanding how heat stress alters gene expression will help elucidate the genetic basis of physiological changes as well as identify targets for possible heat stress mitigation. The purpose of the first study was to understand how heat stress alters the adipose and skeletal muscle transcriptomes in zilpaterol-fed Brahman, as zilpaterol improves muscle growth and may mitigate the effects of heat stress. Differential expression and …

Unmanned Aerial Vehicle (Uav)-Based High-Throughput Phenotyping For Maize Improvement, Eric T. Rodene

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

Modern breeding programs rely heavily on efficiently screening large numbers of genotypes for agronomic traits, such as disease resistance, drought tolerance, and yield. Identifying the genetic loci or genes associated with these traits using GWAS or functional analyses will benefit future plant breeding efforts seeking to incorporate these traits into new crop varieties, whether through conventional breeding or gene editing techniques. Unmanned aerial vehicle (UAV)-based image data has been increasingly used for this task, as it allows entire test plots to be quickly and cost-effectively phenotyped. In my research, I have developed methods to improve the accuracy of machine learning …

Assessment Of Foam Decontamination In Tomato Washing Process, Basim M. Alohali

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

The work of the dissertation investigated the efficacy of foam-based decontamination treatments to enhance microbial safety in Roma tomatoes, specifically targeting natural microflora and Salmonella contamination. Growing concerns over foodborne illnesses linked to fresh tomatoes and the limitations of conventional decontamination techniques, such as organic matter built-up and limited microbial reduction, are addressed. The primary objectives were to characterize the physiochemical properties of foams formed using various concentrations of Tween 20 (T20) and sodium dodecyl sulfate (SDS) with and without the addition of sodium hypochlorite (NaOCl) and peracetic acid (PAA), compare the efficacy of foam and traditional dump tank (DT) …

Identifying The Relative Abundance Of Cell-Cell Signaling Peptides During Mammalian Hibernation And Anesthetic Administration By Label-Free Peptidomics Analysis, Somayeh Mousavi

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

Cell-cell signaling molecules known as neuropeptide and peptide hormones, distributed in both the central nervous system (CNS) and the peripheral nervous system (PNS), regulate a variety of physiological processes including body temperature, feeding, circadian rhythm, reproduction, energy homeostasis, and more. While a number of active neuropeptides structures with physiological functions have been discovered, advances in peptidomic mass spectrometry are enabling researchers to uncover novel, previously unknown, active neuropeptide structures with potential for bioactivities. Using liquid chromatography coupled with tandem mass spectrometry (MS/MS), it is possible to identify a wide range of neuropeptides in single experiments without preselecting specific peptides. Mass …

Genetically Modified Bovine Milk-Derived Small Extracellular Vesicles In Drug Delivery, Alice Kah Hui Ngu

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

Small extracellular vesicles (SEVs, “exosomes”) are natural nanoparticles that can be endogenously synthesized and also obtained from dietary sources, such as bovine milk SEVs (mEVs). mEVs have been extensively studied and discovered with contributive features that potentially play a role in drug delivery and other therapeutic purposes, such as diagnostic tools. Current studies have shown that mEVs have been used preclinically to carry in targeting drugs, nucleotides, biomolecules, and labels to target metabolic diseases and cancers. Extensive studies have focused on further modifying SEVs to enhance their versatility in pharmaceutical use. In this dissertation, we exhibited one of the ways …

Exploring Producers' Willingness To Pay For Ecosystem Services: Three Essays On Soil Health, Location Preferences, And Cover Crop Adoption, Kaouter Essakkat

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

This dissertation comprises three essays: one assessing Midwest producers' willingness-to-pay (WTP) for soil health-enhancing ecosystem services (ES), another examining the impact of policy implementation locations on WTP, and a third identifying factors influencing producers' adoption of cover crops (CC).

The first essay pioneers the understanding of agricultural producers’ valuation of soil health-associated ES amid growing concerns of soil degradation due to agricultural intensification. Using a discrete choice experiment, this study assesses producers’ WTP for a policy that incentivizes ES provision, specifically improved water quality, carbon sequestration, and enhanced crop yield. Surveying producers across Iowa, Kansas, and Nebraska, our results show …

Performance Fatigability And Neuromuscular Responses During And After One Set Of Forearm Flexion Muscle Actions To Failure At 30% Versus 70% One-Repetition Maximum In Men And Women, Tyler Joseph Neltner

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

Previous studies have examined sex differences in performance fatigability during isometric, isokinetic and controlled dynamic constant external resistance (DCER) fatiguing tasks (FT), however, whether those sex differences remain during maximal intended velocity (MIV) DCER muscle actions remains unclear. The purpose of this study was to examine the sex-related differences in the time course of fatigue, neuromuscular responses, and coactivation from the ipsilateral and contralateral limbs during MIV DCER muscle actions to failure at low versus high relative loads, as well as performance fatigability from pre- to post-testing. Twenty-seven college-aged men (n = 14) and women (n = 13) …

Next-Generation Crop Monitoring Technologies: Case Studies About Edge Image Processing For Crop Monitoring And Soil Water Property Modeling Via Above-Ground Sensors, Nipuna Chamara

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

Artificial Intelligence (AI) has advanced rapidly in the past two decades. Internet of Things (IoT) technology has advanced rapidly during the last decade. Merging these two technologies has immense potential in several industries, including agriculture.

We have identified several research gaps in utilizing IoT technology in agriculture. One problem was the digital divide between rural, unconnected, or limited connected areas and urban areas for utilizing images for decision-making, which has advanced with the growth of AI. Another area for improvement was the farmers' demotivation to use in-situ soil moisture sensors for irrigation decision-making due to inherited installation difficulties. As Nebraska …