Life Sciences Commons^™

Functional Genomics Of Phosphatidylcholine Biosynthesis In Saccharomyces Cerevisiae, Amanda Marie Maliva

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

Phosphatidylcholine (PtdCho) is a prominent structural building block of cell and organelle membranes in animal, plant, and fungal cells and some bacteria. Due to its abundant nature in the plasma membrane and intracellular organelle membranes in eukaryotes, the biosynthesis of PtdCho must remain regulated to preserve the correct membrane lipid composition. Dysregulations in PtdCho metabolism can lead to mitochondrial dysfunction, cell death, and the development of diseases including cancer, atherosclerosis, and hepatic diseases. Knowledge of PtdCho has remained limited to the genes involved in its three biosynthetic pathways (Kennedy (K), methylation (M), and acyltransferase (A)), despite the growing realization of …

Aptamer Selection And Development Of Electrochemical Aptamer-Based Sensors For Neuropeptide Y, Evelyn Adela Carreto Guevara

Department of Chemistry: Dissertations, Theses, and Student Research

In this thesis, we report the results of four aptamers obtained from an aptamer selection process called the systematic evolution of ligands by exponential enrichment (SELEX) with affinity to Neuropeptide Y (NPY). NPY is a highly abundant peptide transmitter with widespread distribution throughout the body which affects various physiological functions. These functions include energy homeostasis, appetite regulation, stress response, and anxiety regulation. Dynamic monitoring of NPY levels is crucial for better understanding behaviors in individuals with neurological disorders associated with NPY. Aptamers are synthetic oligonucleotides obtained through SELEX which have a binding affinity to a target of interest when in …

Understanding The Dynamics Of Formal Mentoring In Professional Identity Development Of Early Career Extension Professionals: A Phenomenological Approach, Anuradha Choudhary

Department of Agricultural Leadership, Education, and Communication: Dissertations, Theses, and Student Research

Formal mentoring plays a crucial role in shaping the professional identity of early-career extension professionals; however, limited research has explored how these dynamics affect professional identity development within formal mentorship structures. This study uses a transcendental phenomenological approach to understand how mentees and mentors perceive the impact of formal mentoring on professional identity development within the Nebraska Extension system. Using criteria-based random sampling and snowball sampling, the study engaged 10 mentees and 10 mentors, employing semi-structured interviews, focus groups utilizing ripple effect mapping, and document analysis of mentoring agreements, program guidelines, and mentoring checklists. Following Moustakas' (1994) transcendental phenomenology framework, …

Improved Rumen Microbiome Interpretation Via Empirical Filtration Derived From Known Mock Microbiomes, Wesley A. Tom

School of Biological Sciences: Dissertations, Theses, and Student Research

The rumen microbiome plays a critical role in ruminant health and performance. As a consequence, many studies investigate microbial community composition using 16S rDNA based sequencing. As such, data quality and data filtering are critical to accurately identify microbial community composition. In this study we use mock communities to empirically select data filtering parameters to reduce artifact populations and compared the effect of filtering using different bioinformatic pipelines using rumen bacterial community data. The filtering parameters identified provides consistent estimates of rumen microbial diversity, regardless of bioinformatic pipeline utilized and provides a more accurate view of microbiome structure and composition. …

Associations Of Variation In Mtdna With Feed Efficiency In Beef Cattle And The Evaluation Of Transcriptomic Changes In Fetal Kidney Due To Hydrallantois, Lauren Elizabeth Seier

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

Project 1 focused on the central role that mitochondria play in ATP production, highlighting that variation within the mtDNA may influence feed efficiency. Variation in the mitochondrial genome was uncovered, and associations with feed efficiency in beef cattle were identified. Growth and feed intake phenotypes, as well as low-pass sequencing, were collected on beef steers across two populations. Protein coding variants were identified and used to classify animals into mitochondrial haplotypes. A linear mixed model was employed, which detected a significant association between mitochondrial haplotype and DMI. A significant haplotype with a variant in Complex I was associated with reduced …

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

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

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

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

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

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

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

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

Plant Nutrient Interactions In High-Yielding Soybean Environments, Victoria Inklman

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

Plant nutrient demands and limitations are usually studied individually by nutrient. Here, we investigated how nitrogen (N) limitation in high-yielding soybean environments affects the uptake, removal, and residual of other plant macro- and micronutrients. The objective of this study was to quantify the uptake, removal, and residual levels of soybean macro- and micronutrients under N-limited conditions and to identify nutrient priorities for high-yielding soybean systems. Aboveground plant samples at physiological maturity were collected in 19 high-yielding soybean fields with N limitation across the state of Nebraska. Reference plots with ample N supply were included within each field to compare macro- …

How Beliefs Shape What We Consider When Choosing What To Eat, Christopher Gustafson

Cornhusker Economics

What determines which foods we consider? One factor, certainly, is what we like to eat, and if liking what we eat were the sole relevant outcome of food consumption, there would be little to say about incomplete consideration. However, diet quality has important, well-documented effects on health outcomes (as well as other important considerations, such as differential environmental impact). Close to 75 percent of American adults are overweight or obese, which increases the likelihood that the individual will experience one or more serious non-communicable diseases. A food’s healthiness is an important consideration for many people when making food choices, but, …

Distributional Records Of Blanding’S Turtles (Emydoidea Blandingii) In Nebraska, Sam Thede, Dan Fogell, Keith Geluso

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Blanding’s Turtle (Emydoidea blandingii) is a species of concern in North America as many populations have declined across its distribution. Environmental factors associated with alteration of natural ecosystems have played a role in declines leading to many isolated populations. Most populations exist in the Great Lakes region with a number of outlying populations, such as Nebraska. Understanding the current distribution of the species will facilitate regional management strategies to protect this species into the future. In Nebraska, Blanding’s Turtles were known from 23 counties prior to this study. Herein, we report on eight new county records, five (Blaine, …

Simulated Walleye Responses To Various Harvest Regulations In A Nebraska Reservoir, Mikael Ranta, Melissa Wuellner, Keith D. Koupal

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Recreational fishing provides sociological and economic benefits, and fish populations are managed by state agencies to meet angler expectations. One of the most popular species in Midwest reservoirs are walleye (Sander vitreus), and most of these fisheries have established restrictions on the number and sizes of fish harvested. Regulations are set based on population structure and dynamics and management goals, but often agencies have incomplete information needed to establish regulations. Predictive models can provide insight on population responses and inform managers of the tradeoffs between angler restrictions and population sustainability. Lake McConaughy, Nebraska, supports a popular walleye fishery. …

A New Species Of Viscachataenia (Cestoda: Anoplocephalidae) From The Southern Mountain Viscacha, Lagidium Viscacia (Hystricomorpha: Chinchillidae), In Bolivia, Terry R. Haverkost, Scott L. Gardner

MANTER: Journal of Parasite Biodiversity

Anoplocephalid cestodes collected from the southern mountain viscacha, Lagidium viscacia, in Boliva in 1986 are here examined, and a new species of Viscachataenia is described. The new species has numerous body measurements that are larger than the existing species, V. quadrata, but the eggs and corresponding structures of the new species are all smaller than those of V. quadrata.

Cropland Acres Vs Base Acres In Nebraska, Jessica J. Groskopf, Cory Walters

Cornhusker Economics

Discusses cropland acres versus base acres in Nebraska.

Veterinary Drug Residue Regulations In Major U.S. Export Markets, Elliott James Dennis, Akinbode Okunola

Cornhusker Economics

Trade agreements shape the global agricultural trade landscape, encompassing both tariff and non-tariff measures. Among the latter, sanitary and phytosanitary (SPS) measures such as maximum residue limits (MRLs) are gaining attention. As trade tensions escalate, there is growing concern that countries could use SPS measures as a tool of retaliation in international agricultural markets, as they are often a focal point in trade negotiations (Disdier and Marette, 2010; Disdier and van Tongeren 2010; Grant et al., 2015).

Update To: Advancing Butterfly Systematics Through Genomic Analysis, Jing Zhang, Qian Cong, Jinhui Shen, Leina Song, Nick Grishin

The Taxonomic Report of the International Lepidoptera Survey

In this update, we propose (type species or type localities in parentheses): Lochris Grishin, nom. nov. (Lasaia oileus Godman, 1903; Lepidoptera: Riodinidae) as a new substitute name for Locris Grishin, 2025 preoccupied by Locris Stål, 1866 (Cercopis rubra Fabricius, 1794; Hemiptera: Cercopidae), 5 new species, and 5 new subspecies: Emesis (Mandania) mandarina Grishin, sp. n. (Brazil: Santa Catarina) and Emesis (Mandania) mandela Grishin, sp. n. (Venezuela, Carabobo) in Riodinidae Grote, 1895 (1827); others in Hesperiidae Latreille, 1809: Telegonus (Rhabdoides) flavifimbro Grishin, sp. n. (Colombia), Urbanus (Urbanoides) dolus Grishin, sp. n. (Colombia: …

Larger Price Limits For Cattle Futures Contracts: Should We Pay Attention To That?, Fabio Mattos

Cornhusker Economics

The CME Group has recently announced an increase in price limits for its cattle futures contracts. This means that cattle futures prices now have a wider range to fluctuate on any given day, and the possibility of larger price fluctuations implies that traders may find larger gains as well as larger losses in their trading accounts at the end of the day. This is certainly something that people trading in futures markets should be aware of, but the change in price limits itself is just a regular update that happens every year. Let's take a closer look at this.

Biocomputing Approach To Modeling And Modulating Calcium Signaling, Sehee Sun

School of Computing: Dissertations, Theses, and Student Research

Biocomputing is an emerging field that seeks to perform computational tasks using biological substrates and processes. Unlike conventional computing systems based on silicon hardware, biocomputing leverages the parallelism, energy efficiency, and complex dynamics of living systems. Among various cellular mechanisms, calcium (Ca2+) signaling stands out as a central regulator of diverse biological functions, offering a promising basis for programmable logic and control in living cells.

This thesis introduces a novel framework for modeling and modulating Ca2+ dynamics using biologically inspired Boolean logic circuits. Specifically, we propose the Ca2+ Boolean Logic (CaBL) model, in which Ca2+ fluxes and interactions are abstracted …

Attitudes Towards Insects: An Attempt To Change Negative Attitudes To Neutral Or Positive, Christina Chapman

Department of Entomology: Distance Master of Science Projects

Purpose and Summary

The purpose of this project was to examine whether negative attitudes towards insects could be changed in children after learning about them in a safe and enjoyable environment. At the start of this project, I was a science teacher in an urban middle school, where most students were neither fond of nor interested in insects. This experience shaped my project: I wanted to change attitudes from negative to positive, transforming “eww gross, kill it!” into “let it live; it has a job to do.” Through my studies in the entomology program, my belief that insects are highly …

Soil Health In Nebraska: Exploring Practitioners' Needs And Insights From A Long-Term Organic Farm, Ingrids Isabel Mata Vigil

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

Soil health is foundational to sustainable agriculture, environmental resilience, and long-term food security. Yet, the adoption of soil health assessments remains limited, often perceived as too technical, costly, or difficult to implement in real-world contexts. To better understand these challenges, the first chapter presents findings from a statewide survey of 41 soil health practitioners in Nebraska, including farmers, extension educators, NRCS staff, and conservation professionals. Respondents highlighted the need for simpler, more accessible, and context-specific tools for soil health assessment that help practitioners make informed decisions aligned with their management goals. Complementing these insights, the second chapter includes an independent, …

Use Of High-Throughput Phenomics With And Without Fungicide As A Wheat Breeding Tool, Gerardo Ivan Rivera Collazo

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

Wheat (Triticum aestivum) is an important food staple for many countries around the world and current consumption and production data demonstrate a production deficit. Breeders are challenged to help close this gap in production by selecting better cultivars with improved yields. Several methods aim to accelerate the breeding process to reduce the time required for releasing an elite variety. One of the main breeding bottlenecks is the lack of fast and reliable phenotypic data acquisition that could dissect physiological and morphological plant data. High-throughput remote sensing could have the potential to reduce this bottleneck by streamlining data acquisition, …

Catching A Fever: A Comparison Of Vachellia Xanthophloea Populations In The Limpopo And Luvuvhu River Floodplains Of The Makuleke Contractual Park, Kianie B. David

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

This study investigates patterns of stand structure regeneration, growth characteristics, and coarse woody debris (CWD) patterns in Vachellia xanthophloea (fever tree) stands within the Makuleke Contractual Park (MCP), a semi-arid savanna system in northern Kruger National Park (KNP), South Africa. Fieldwork was conducted across two stand types: a monospecific fever tree stand in Rietbok Vlei and a mixed-species stand in the Western Nhlangaluwe Floodplain where fever tree is established with Faidherbia albida (ana tree). Data were collected from 20 total 1/4-acre (1,011 m²) circular plots between both stands in 2024 and 2025, including seedling root collar diameter (RCD), …

Bioenergy Crop Production: Implications For Grassland Bird Communities In Southwestern Nebraska, Grace E. Schuster

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

Biofuel and bioenergy systems are components of most climate stabilization pathways to reduce greenhouse gas emissions and limit global warming. Currently, corn (Zea mays) is the predominant feedstock used for bioenergy production in the United States. However, widespread production of this monoculture crop has resulted in many negative environmental impacts. The most notorious impact has been the loss of grassland habitat due to agriculture expansion which has had detrimental effects on wildlife that depend on grassland habitat. One such group, grassland birds, has faced steeper, more consistent, and more widespread declines than any other avian guild. Therefore, strategies …

Primary Investigation Of Rice-Fish Co-Culture: Investigating The Feasibility Of Raising Fish In Flooded Rice Paddies In The Southern Usa, Yulin Jia, Aaron K. Jackson, Bartholomew Green, S. Adam Fuller, Heather Box, Laduska Sells, Candis Ray, Paxton Harper, Brennan Smith

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

With limited land and water resources available it has become critical to maximize output for agricultural products while maintaining sustainable farming practices. Ricefish co-culture can be used to maximize limited land and water resources for production of rice and fish concurrently and reduce the need of chemical inputs. While rice-fish co-culture has been practiced in Asia for centuries, very few studies have examined the feasibility and economic impact of rice fish co-culture in the U.S.A. Two studies were conducted in Stuttgart, Arkansas, U.S.A. from 2023-2024 to investigate the suitability of raising Koi carp in flooded rice paddies with a sushi …

Response Of Soybean To Variable Irrigation Levels In Eastern Nebraska Using The Aquacrop Model, Anmol Singh

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

AquaCrop was calibrated and validated for soybean [Glycine max (L.) Merr.] using 19 irrigation treatments from five years using data from field experiments. The model accurately simulated canopy cover (CC), soil water content (SWC), and grain yield, with overall validation nRMSE values of 12%, 7%, and 7%, respectively. The overall validation nRMSE for SWC in individual 30-cm soil layers was comparatively higher, at 19%. The model was subsequently applied for long-term simulations (2010–2024) to estimate soybean yield and water requirements for two dominant soil types, Yutan silty clay loam and Tomek silt loam under three irrigation levels - rainfed, …

Overcoming Maternal Antibody Interference In Swine Influenza: Advancing Dna Vaccine Strateies For Enhanced Immune Protection In Piglets, Danh Cong Lai

School of Veterinary and Biomedical Sciences: Dissertations, Theses, and Student Research

Maternally derived antibodies (MDAs) play a vital role in protecting neonates from infectious diseases, but their presence at the time of vaccination can interfere with vaccine-induced immune responses, thereby reducing vaccine effectiveness. MDA interference has been documented in pigs vaccinated with whole inactivated virus (WIV) vaccines against swine influenza A virus (IAV). In this thesis, we evaluated the efficacy of a lipid nanoparticle encapsulated DNA (LNP-DNA) vaccine against swine IAV in the presence and absence of MDAs, comparing it to a WIV vaccine. In MDA-negative piglets, both the LNP-DNA and WIV vaccines induced strong immune responses and effectively prevented the …

Reaction Control Mechanism In Deoxyuridine 5'-Triphosphate Nucleotidohydrolase, Aaron Delay

School of Biological Sciences: Dissertations, Theses, and Student Research

Deoxyuridine 5'-triphosphate nucleotidohydrolase (dUTPase) is an enzyme involved in the pyrimidine biosynthesis pathway, a key component of cellular DNA metabolism. It regulates intracellular uracil carrying triphosphate levels by hydrolyzing dUTP, thereby providing a substrate for thymidylate synthase (TS). The effective inhibition of dUTPase is expected to enhance TS-targeted chemotherapy by promoting thymine-less apoptosis.

Although the reaction mechanism of dUTPase has been studied, the human nuclear homotrimeric form remains complex, as all three subunits cooperatively form a single active site. As a result, the detailed molecular dynamics of its catalysis are still not fully understood. In this study, I investigated the …

Evaluating The Effects Of Row Spacing, Legume Intercropping, Fertilizer Source, And Fertilizer Timing On Intermediate Wheatgrass In Eastern Nebraska, Madeline M. Johnston

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

Kernza^® is the trademarked name of the perennial crop intermediate wheatgrass (Thinopyrum intermedium). In addition to its potential for dual-use as a grain and forage crop, Kernza is marketed to provide needed environmental services by increasing crop biodiversity, sequestering soil carbon, and reducing nitrate leaching. However, more work is needed in cultivar selection and crop management to increase total grain yields and prevent long-term grain yield decline. Furthermore, research in quantifying and understanding Kernza’s ability to affect soil properties and water dynamics is limited.

Two field experiments were conducted at the Eastern Nebraska Research Extension and Education …

Evaluating Biodegradable Mulch As A Soil Conservation Tool And The Impact On Soil Properties And Yield In Soybean (Glycine Max) Cropping Systems In Eastern Nebraska, Ana Clara Gomes

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

This study, conducted during the 2024 growing season, evaluated short-term effects of soil management practices on greenhouse gas (GHG) emissions, soil microclimate, nitrogen dynamics, weed suppression, and soybean (Glycine max) yield. In addition to conventional tillage and no-till, this research included cereal rye (Secale cereale) cover cropping and a novel sprayable biodegradable mulch (BioWRAP®) to assess emerging strategies for sustainable soybean systems under contrasting moisture regimes.

Field trials were established at two eastern Nebraska locations: Havelock (dryland, silty clay loam) and ENREEC (irrigated, clay loam). A strip-block randomized design with four replications tested six soil management …

Cazyme Gene Cluster Diversity In Human Gut Microbiome, Yi Xing

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

In gut microbiome research, carbohydrate-active enzyme gene clusters (CGCs) have emerged as key functional units for understanding microbial glycan degradation. Unlike taxonomic or broad pathway annotations, CGCs offer gene-cluster-level resolution and capture substrate-specific microbial functions. However, their diversity and distribution in relation to host metabolic phenotypes, such as obesity, remain poorly characterized. This study tests the hypothesis that the composition and abundance of fiber-targeting CGCs vary between obese and healthy human gut microbiomes, reflecting distinct microbial carbohydrate utilization strategies. To examine this, we constructed a high-quality reference CGC dataset comprising 94,019 clusters from the Unified Human Gastrointestinal Genome and profiled …

Annotated Checklist And Distribution Of The Jewel Beetles (Coleoptera: Buprestidae) Of Idaho, Luc Leblanc, Emma L. Eakins

Insecta Mundi

An annotated checklist of the 102 species of Buprestidae (Coleoptera) known to be present in the state of Idaho is provided, with photographs and detailed distribution maps for each species. The checklist is based on label data from 7,506 museum specimens, 21 observations obtained from iNaturalist.org and Bug-Guide.net, and 63 distribution records from published literature. Buprestis consularis Gory is a new record for Idaho, formerly reported as Buprestis nutalli Kirby, which is not known to occur in the state. Obscure past records of Anthaxia retifera LeConte and Melanophila occidentalis Obenberger published in the literature are regarded as dubious and are …