Life Sciences Commons^™

The Development Of Tools For The Production Of Fusarium Oxysporum Race 4 Resistant Cotton Varieties, Thomas Rylands

All Theses

Fusarium oxysporum race 4 (FOV4) is a fungal pathogen that infects cotton (Gossypium spp.) plants, resulting in fusarium wilt (FW) disease that causes significant wilting, yield loss, and eventually death. Since cotton is such an important crop globally, with tens of millions of bales of fiber produced and sold worldwide each year, it is critical to develop effective strategies to combat this pathogen. This research aims to achieve that goal through two projects: (i) develop an efficient co-culture system to test fungal treatments in vitro, and (ii) develop a computer vision pipeline to more accurately assess plant resistance …

Evaluation Of Ocean Lidar Enhancement Through Miniaturization And Gated Pmt-Based Range Extension, Chandler Austin Slater

OES Theses and Dissertations

Oceanographic lidar systems remotely characterize the vertical structure of the upper ocean by recording the light backscattered from a laser pulse as it propagates through the water column. Historically these systems have been constrained by limited detection ranges, often capturing only a portion of the illuminated water column, typically fading to noise around the 10% isolume. A primary constraint has been the limited dynamic range of digitizers, which inhibits the ability to resolve both intense near-field and faint far-field backscatter signals within a single acquisition. To address this, we developed a novel optical lidar system incorporating gated photomultiplier tubes (PMTs) …

Molecular Pathway Dysregulation In Chronic Liver Disease: Metabolic And Mechanotransductive Drivers Of Hepatic Pathophysiology, Samantha Harvat

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Metabolic dysfunction–associated steatotic liver disease (MASLD) represents a rapidly growing cause of chronic liver injury, yet the molecular interactions linking metabolic stress, inflammation, fibrosis, and hepatocellular carcinoma (HCC) remain incompletely defined. This thesis integrates transcriptomic analyses across multiple GEO datasets to identify coordinated metabolic, inflammatory, and mechanotransductive pathways that collectively drive disease progression.

Analysis of human liver biopsy datasets (GSE126848 and GSE89632) revealed consistent suppression of glycolysis, β-oxidation, and oxidative phosphorylation across MASLD and MASH samples, accompanied by modest compensatory TCA cycle activation. These alterations reflect impaired metabolic flexibility, mitochondrial stress, and increased ROS susceptibility. Concurrently, cytokine-network enrichment demonstrated activation …

Fragmentation In The U. S. Fed Cattle Market: Implications For Price Transparency And Discovery, Taralee M. Hudson

Department of Agricultural Economics: Dissertations, Theses, and Student Research

The U.S. fed cattle market is one plagued by recurring stakeholder concern. Market participants frequently raise questions about the transparency of fundamental information under existing reporting frameworks, and the extent to which Private Negotiation, the dominant trading institution, effectively facilitates price discovery. Although extensive research has sought to address these issues, much of it has failed to account for the market’s increasingly fragmented structure. This thesis is comprised of three chapters that collectively examine price transparency and discovery through the lens of market fragmentation. Each chapter presents research related to the fed cattle market and is intended to stand …

Two Essays On Agricultural Trade Policy And Total Factor Productivity, Hanifi Otgun

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

This dissertation consists of two essays: the first examines the welfare and trade implications of the 2016–2017 drought in Brazil and the subsequent temporary import ban on Robusta coffee; the second examines how trade openness influences agricultural total factor productivity across 26 NUTS-2 regions in Türkiye from 2013 to 2020.

The first essay focuses on Brazil, a major Robusta coffee producer and exporter that faced a significant drought in 2016–17, reducing Robusta output. In response, the government initially allowed one million 60-kg bags of Robusta coffee to be imported. An import ban was imposed shortly afterward due to lobbying by …

Evaluating Fall And Spring Planted Cover Crops For Integrated Management Of Herbicide Resistant Palmer Amaranth And Effect On Soil Health, Vipin Kumar

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

Herbicide-resistant Palmer amaranth (Amaranthus palmeri S. Watson) pose a severe threat to agronomic crop productivity in the United States, including corn and soybean production in Nebraska. Therefore, there is an urgent need for diversified and sustainable management approaches. Integrating cover crops (CCs) with herbicide programs represents a promising strategy to achieve Palmer amaranth suppression, sustain crop yields, and contribute to long-term soil health in irrigated corn–soybean production systems in Nebraska.

A meta-analysis of 41 studies and 595 paired observations demonstrated that CCs reduced Amaranthus spp. density and biomass by 37–59% depending on the growing season, with grasses and mixtures …

Detecting Prescribed Fire, Haying And Grazing Events Via Remote Sensing To Create Grassland Disturbance Landcovers For The Ring-Necked Pheasant (Phasianus Colchicus), Megan Amy Baldissara

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

This dissertation developed disturbance detection models to fulfill the need for remote sensing landcover products describing grassland structure. The use of landcover products derived from remote sensing is increasing over time in pheasant (Phasianus colchicus) research. Such landcover, however, does not provide relevant pheasant structural habitat information (Chapter 1). Pheasants require tall, high-density grassland for nesting, tall grassland with medium density for brood rearing, and tall grassland for wintering. Time since disturbance can serve as a proxy for structure, as it shapes vegetation by removing biomass and resetting succession. Disturbance is easier to detect than structure with current …

An Integrated Modeling Framework To Evaluate Circularity Of The Corn–Water–Ethanol–Beef Nexus, Heydi Han

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

This dissertation examines the transition from conventional linear agricultural and food bioenergy systems toward more circular, resilient, and resource-efficient configurations. Prior research indicates that spatial and temporal variability in soil, weather, animal biological responses, and management decisions strongly influences productivity, nutrient-use efficiency, and profitability. Studies have also shown that a diversified circular system can buffer these sources of variability, improving stability and adaptive capacity. Building on these insights, the central focus of this work is to develop an integrated modeling framework to evaluate circularity within the Corn-Water-Ethanol-Beef (CWEB) nexus and explore how climate variability and management choices shape system-wide performance. …

Ogallala Fall Field Days, Janis Paseka

Nebraska Bird Review

The 2025 NOU Fall Field Days were held in Ogallala on September 26–28, with about 80 in attendance. The programs were held at the Quality Inn, and the meeting was planned by Boni Edwards, Dave Cunningham, and Paul Pearson. Field trips were led by Tobin and Keegan Brown, Jacob Cooper and UNK ornithology students, Joel Jorgensen and Stephen Brenner, T. J. Walker, and Thane Dinsdale. Destinations included various sites around Lake McConaughy, Lake Ogallala, Cedar Point Biological Station, Sutherland Reservoir SRA, Ash Hollow State Historical Park, Crescent Lake NWR, Arthur Co and various Sandhills lakes. The total species count was …

Post-Fire Soil Health Assessment Of The Grasslands And Woodlands In The Semi-Arid Nebraska Sandhills, Stephanie M. Lugo

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

Grasslands in the Nebraska Sandhills are shaped by natural wildfires, which help maintain the structure and function of native grasslands. In recent decades, afforestation with ponderosa pine and eastern redcedar has introduced new woodlands that altered the region’s fire dynamics and raised important questions about the effects of wildfire on different vegetation types. As wildfires become more frequent, understanding their impacts on soil health in grasslands and woodlands becomes increasingly important. This study examines the short-term effects of the 2022 Bovee Fire on physical, chemical, and biological soil properties in native grasslands and ponderosa pine and eastern redcedar afforested woodlands. …

Skeleton Weed Program 2024-25: Annual Report To Grain Growers, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity published reports

Skeleton weed is a major pest of grain crops and can significantly reduce grain crop yields by competing for moisture and nutrients (mainly nitrogen), due to its deep perennial root system.

Skeleton weed is a declared plant in WA under section 22 of the Biosecurity and Agriculture Management Act (2007) and is assigned to control category 2 (Eradication) for the whole of the State, except in the Narembeen and Yilgarn Shires, where it is category 3 (Management).

Modelling indicates that under a nil management scenario, the cost to WA broadacre agriculture will be approximately $19.2 million per year after twenty …

From Mechanisms To Management: Implications Of Biogeochemical Controllers And Land Management For Soil Carbon Cycling And Storage, Savannah R. Adkins

All Graduate Theses and Dissertations, Fall 2023 to Present

Climate change and its cascading effects are driven by increases in atmospheric carbon dioxide (CO₂). Many climate solutions exists to remove this excess carbon (C) from the atmosphere, and soils, in particular, represent one of the few win-win solutions. Soils play a vital role in the global C cycle because they store more C than plants and the atmosphere combined, however, they also release more CO₂ annually than fossil fuel combustion (a major contributor to accelerating climate change). Therefore, preventing CO₂ loss from soil could help slow the progression of climate change, and increasing overall soil …

Understanding Impact Of Starter Culture Blends On The Ph Variation In Cheddar Cheese During Early Aging, Samuel J. Clarke

All Graduate Theses and Dissertations, Fall 2023 to Present

Consumer expectations govern what is acceptable when it comes to the flavor, texture, and color of the cheese. These quality attributes of cheese are all influenced by the pH of the cheese which is in turn controlled by the acid production of the starter lactic acid bacteria (SLAB) used to make cheese. Whatever the final pH of the cheese is, is what determines the quality of the cheese. Unfortunately, there are some Cheddar cheese manufacturers that have observed pH variation during the early aging of their cheeses. We hypothesize that the addition of thermophilic, fast-acid producing bacteria, like Streptococcus thermophilus …

Characterization And Recycling Of Waste Gabbro Stone Powder As A Sustainable Cement Replacement, Jad Bawab, Hilal El-Hassan, Hassan Al Zagha, Maisa El Gamal

All Works

Cement production significantly contributes to climate change due to its high carbon emissions and resource-intensive processes. With traditional cement alternatives dwindling, exploring underutilized resources is crucial. This study investigates gabbro stone powder (GSP), an abundant byproduct in the United Arab Emirates (UAE), as a partial cement replacement in blended pastes. The characteristics of GSP were determined using standardized procedures. Then, it was incorporated into mixes at 0 %, 5 %, 10 %, and 20 % cement replacement levels with water-to-binder (w/b) ratios of 0.30, 0.35, and 0.40. Characterization revealed GSP as a siliceous-aluminous material with limited hydraulic activity. Experimental results …

Exploring The Path To Sustainable Firm Performance: The Role Of Leadership, Learning, And Procurement In Smes, Manar Fawzi Bani Mfarrej, Imane Belyamani, Syed Zamberi Ahmad, Abdul Rahim Abu Bakar

All Works

This study explores how sustainability leadership influences sustainable firm performance in small and medium-sized enterprises (SMEs), with a particular focus on the mediating roles of sustainable procurement and organizational learning. Anchored in the dynamic capabilities view (DCV), the research proposes leadership, learning, and procurement practices as dynamic capabilities that enable firms to adapt, transform, and thrive amid sustainability-related challenges. Data were collected from 476 SMEs across the United Arab Emirates (UAE), including middle- and senior-level managers, owners, and CEOs. The proposed hypotheses were tested using partial least squares structural equation modeling (PLS-SEM). The findings reveal that the direct effect of …

Genomic And Functional Characterisation Of Endophytic Bacterium Bacillus Cereus Strain E1 Alleviating Salt Stress And Enhancing Tomato Physiology And Spectral Indices, Balamurugan Sadaiappan, Tanveer Alam Khan, Qurban Ali, Sulamita Santos Correa, Mahideen Afridi, Soumaya Tounsi Hammami, Munawwar Ali Khan, Sunil Mundra

All Works

Mangroves in arid environments represent unique ecological niches that support a diverse range of microorganisms. Endophytic bacteria residing within host plants play a crucial role in promoting plant growth by enhancing pathogen resistance and alleviating environmental stress. Identifying novel stress-tolerant strains, specific to arid environments, is essential for expanding the repertoire of plant growth-promoting bacteria (PGPB). In this study, we investigated the saline tolerance of the endophytic bacterium strain E1, previously isolated from the root of Avicenna marina (grey mangrove). Whole-genome sequence (WGS), phylogenetics and average nucleotide identity (ANI) analysis were performed. The strain exhibited high salinity tolerance, growing in …

Efficacy Of Zinc Oxide Nanoaciculates As Antagonists Against Meloidogyne Javanica On Phaseolus Abyssinicus, Manar Fawzi Bani Mfarrej, Faheem Ahmad, Amir Khan, Mohd Sajid Ali, Hamad A. Al-Lohedan, Arshad Iqbal, Khalid Umar, Gulam Rabbani, Mohd Farhan Khan

All Works

This work investigates the synthesis of zinc oxide nanoaciculates (ZNA) using the Sol–gel method and their potential as a long-term bio-control agent against Meloidogyne javanica, a root-knot nematode that causes severe damage to Phaseolus abyssinicus. The produced ZNA were evaluated using SEM–EDS, X-ray diffraction (XRD), and UV–Vis spectroscopy to ensure precise evaluation of their nanoscale characteristics. Bio-efficacy assays were carried out at four concentrations (125, 250, 375, and 500 mg/L) to evaluate nematicidal activity on juvenile nematodes (J2) and M. javanica egg masses. The results showed that ZNA had significant toxicity at all doses, with the highest efficacy observed at …

Impacts Of Halophila Stipulacea Invasion On Organic Matter Dynamics In Thalassia Testudinum Dominated Seagrass Meadows, Puerto Rico, Jonathan D. Herald

Master's Theses

Halophila stipulacea (Forsskål & Niebuhr) is a tropical seagrass native to the Red Sea, Persian Gulf, and Indian Ocean. In 2002, invasive populations of H. stipulacea were identified in the Caribbean Sea where it now forms large meadows, displaces native seagrasses, alters invertebrate and fish communities, and potentially affects organic matter dynamics in invaded meadows. This study investigated differences in organic matter dynamics between meadows of H. stipulacea and native Thalassia testudinum within the Jobos Bay National Estuarine Research Reserve (JBNERR) on the southern coast of Puerto Rico. From March 2023-March 2024, sampling was conducted across four sites to investigate …

Effects Of Urbanization On The Population Genetics And Morphology Of The White-Footed Mouse (Peromyscus Leucopus) Across An Urban–Rural Gradient, Sydney A. Morton

Master's Theses

Urbanization alters landscapes in ways that can reshape wildlife populations by changing habitat connectivity, resource availability, and selective pressures. To investigate how urbanization influences both genetic differentiation and morphology in small mammals, I examined Peromyscus leucopus (PELE) across an urban–rural gradient in northern Georgia. Using RADseq SNP data from PELE individuals across 13 sites, I quantified pairwise genetic differentiation (F_ST) and tested how various environmental variables, including impervious surface cover, human population density, and tree canopy cover, predict genetic differentiation after accounting for geographic distance. Genetic differentiation increased with geographic distance and, after controlling for isolation by …

Strategic Enhancement Of Biofuel Production Using Bacillus Subtilis As A Model Organism: A Dual Approach Of Gene Essentiality Mapping And Optimization, Angela A. Zebede

Electronic Theses and Dissertations

With rising global demand for renewable energy, enhancing microbial platforms for biofuel production is vital. This study engineered Bacillus subtilis to improve resilience to solvent stress by targeting membrane lipid biosynthesis pathways essential for integrity. Growth curve analysis (OD₆₀₀) showed that phosphatidylserine (PS) and phosphatidylethanolamine (PE) knockout strains grew significantly slower than wild type (168), indicating the importance of these lipids under stress. Laurdan fluorescence spectroscopy was used to assess membrane properties. Generalized polarization (GP) analysis revealed a concentration-dependent reduction in membrane order upon 1%–2% 1-butanol exposure. GP values declined progressively from control to 2% treatment, reflecting increased membrane fluidity …

Mountain Communities During A Time Of War: A Case Study Of The Hutsul Region In The Carpathian Mountains Of Ukraine, Pavlo Rybaruk

Electronic Theses and Dissertations

This thesis investigates the ethno-ecological technologies employed by the Hutsul people within the highland agrarian economy of the Carpathian Mountains. Over centuries, the Hutsuls have developed ethno-ecological technologies that maintain ecological integrity while supporting community livelihoods.

The study addresses three primary research questions: What are the most important ethno-ecological technologies of the Hutsul highland economy? How might these traditional ethno-ecological practices be applied to economic, agricultural, and tourism development in the Hutsul region? How might these traditional ethno-ecological practices be combined with contemporary approaches to encourage sustainable development in the region?

The research explores the devastating impact of the Russian …

Novel Approaches To Disinfecting Poultry Processing Wastewater For Reuse, Seth Olorunmijuwonlo Adesope

Graduate Theses and Dissertations

Water is an essential resource used in poultry processing, generating large volumes of foodborne pathogen-rich wastewater posing treats to public health. Treating poultry processing wastewater (PPW) is crucial for safe water reuse and sustainable development. Conventional disinfection methods like aerobic digestion and chlorination, although effective, impose considerable operational cost and generate harmful by-products. Integrated recycling systems such as advanced oxidation processes (AOPs) which destroy micro-organisms through the generation of reactive oxygen species (ROS) present a promising opportunity for enhancing resources and sustainability. This study investigated the use of photo-electrochemical (PEC), specifically by combining electrochemical (EC) and photochemical (PC; Photosensitizer and …

Solar Powered Conservation: The Effects Of Solar Photovoltaic Facilities On Avian Community Composition, Michael Christopher Ferrara

Graduate Theses and Dissertations

The expansion of solar photovoltaic energy infrastructure is transforming landscapes worldwide. Increasingly, facilities are planted with native vegetation, yet how vegetation characteristics and landscape variables shape wildlife communities in solar facilities remains poorly understood. Because avian populations have been in decline and are sensitive to habitat changes, understanding how solar facilities influence avian communities is important. In Chapter 1, we used autonomous recording units, local vegetation measurements, and land use and land cover data to quantify how avian community occupancy is influenced by solar cover in solar facilities and comparable reference sites. We used a Bayesian multi-species occupancy model to …

Transcriptomic And Contractile Adaptations In Skeletal Muscle In A Rodent Model Of Anorexia Nervosa, Oscar Armando Vicen

Graduate Theses and Dissertations

BACKGROUND: Anorexia Nervosa (AN) is a psychiatric disorder marked by severe chronic caloric restriction and is primarily diagnosed through psychological and behavioral symptoms. AN has the highest mortality of any psychiatric disorder with an increased risk of all-cause mortality. Many individuals with a history of AN experience incomplete recovery despite intervention treatment. Skeletal muscle molecular mechanisms under chronic energy deprivation remain poorly understood. PURPOSE: To investigate transcriptomic profiles of the gastrocnemius muscle following one month of a rodent model of AN. This study analyzed whether the molecular changes correlate with collected muscular force data to provide a comprehensive understanding of …

Predictive Modeling Of Listeria Monocytogenes Growth In Ready-To-Eat Meat Products, Manjari Singh

Graduate Theses and Dissertations

Listeria monocytogenes remains a significant food safety concern in ready-to-eat (RTE) meat and poultry products due to its persistence under refrigerated and stressed conditions. Predictive models play a vital role in risk assessment and food safety management; broth models are highly conservation & results in overprocessing. This thesis focuses on developing and validating meat-specific predictive models for Listeria monocytogenes growth and lag for RTE beef, pork, and poultry products. Matrix-specific secondary models were built to predict the maximum specific growth rate (μmax) of Listeria monocytogenes under varying environmental conditions, including temperature, pH, water activity, salt, organic acids, and nitrites. Growth …

Multiple Aspects Of Environmental Temperature Have Complex Interactions With Avian Parental Behavior To Influence Offspring Outcomes, William H. Kirkpatrick

Graduate Theses and Dissertations

Anthropogenic climate change is projected to shift not only average temperatures across the globe, but also the amount of thermal variation experienced in the natural environment. Exposure to shifts in averages and a wider range of thermal experiences will cause shifts in wildlife behavior. In avian species, behaviors exhibited during reproduction have implications for the well-being of their offspring. Here, I explore specific incubation behaviors in four species: Scaled Quail (Callipepla squamata), Northern Bobwhite Quail (Colinus virginianus), Tree Swallows (Tachycineta bicolor), and Eastern Bluebirds (Sialia sialis). I examined constancy, or the percentage of time on the nest, and off-bout duration, …

Using Color And Fluorescent Spectrometry As A New Rapid Cleaning Verification Method In Poultry Processing Plants, Clark Griscom

Graduate Theses and Dissertations

The poultry industry is expected to be growing at 3% in the total global market with the U.S. being the largest producer of poultry meat. Poultry processing plants are expected to produce 140 birds per minute with the potential of up to 175 birds per minute to meet the market demand. With the growing market and need for faster production, maintaining food safety needs to be a priority to ensure the safety of consumers. Over 9.9 million foodborne illness cases are reported each year in the United States. A change in food safety is needed, and one area lacking is …

Next-Generation Salmonella Inactivated Vaccine Platforms And Phytobiotic-Modulated Immune Responses In Poultry, Santiago Uribe Diaz

Graduate Theses and Dissertations

Here, a comprehensive understanding of immune responses triggered by either a multimeric CD40 receptor-agonistic DNA aptamer-based or mannosylated chitosan-based Salmonella Enteritidis inactivated vaccine platforms, along with phytobiotic supplementation as an immune modulatory strategy in response to Salmonella lipopolysaccharides, is presented. This dissertation supports the development of next-generation Salmonella vaccine platforms that simultaneously stimulate both protective cell-mediated and humoral immune responses, while indicating the potential immunomodulatory effects of phytobiotics supplementation to reduce the immunological impact of Salmonella lipopolysaccharides in chickens. The first chapter describes that both vaccine platforms administered in broiler chickens initiated local inflammatory responses, recruiting heterophils and macrophages from …

Micro-Greens, Not Micro-Yellows: Evaluating Dehydration-Based Preservation Techniques For Reducing Foodborne Pathogens And Quality Preservation On Microgreens, Travis S. Sananikone

Graduate Theses and Dissertations

Microgreens are increasingly popular among consumers due to their high nutritional value. However, their limited shelf-life remains a significant challenge. To extend their usability, small-scale growers increasingly apply home preservation methods like warm air drying or freeze-drying. However, the effects of these methods on common foodborne pathogens are not well understood. Radish and alfalfa microgreens were inoculated with cocktails of Salmonella enterica, Escherichia coli O157:H7, and Listeria monocytogenes 4b (ca. 8.0 log CFU/g). Treatments included dehydration in a commercial dehydrator, freeze-drying (-20°C, 24 h), and convective drying in an oven (60°C for 4 h), and convective drying in an oven …

Drivers Of Ecosystem Respiration In The Middle Rio Grande Floodplain Aquifer, Eva Tipps

Biology ETDs

Little is known about carbon flux and ecosystem metabolism in river floodplains, despite their potentially large and dynamic contributions to carbon storage and loss. We hypothesized that the region of intermittent saturation (ROIS), which is the subsurface interface between terrestrial and aquatic ecosystems, is a biogeochemical ‘hotspot’ for ecosystem respiration and carbon transformation. Groundwater depth and variability in the ROIS facilitate interactions between aquatic and terrestrial processes, but their role in carbon fluxes is poorly understood. We developed a novel method utilizing high-frequency sensors in groundwater wells to capture biogeochemical ‘hot moments’ of ecosystem respiration in the ROIS of the …