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Genome-Scale Metabolic Modeling Of Chitin-Degrading Microbial Systems, Aimee Kristin Kessell

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

As a major component of fungal cell walls and exoskeletons of invertebrates, chitin is widespread in soils, constituting the second most abundant biopolymer in nature. Composed of N-acetyl-D-glucosamine chains, it serves as a vital source of nutrients, including both carbon and nitrogen, for the growth of microorganisms. A solid understanding of the microbial degradation of chitin is critical for predicting their impacts on biogeochemical cycling in soil ecosystems. Organisms that degrade biopolymers (degraders) produce energetically expensive extracellular enzymes to break down complex organic carbons into simpler labile forms that are sharable with other species, including those that do not contribute …

Sarcopenia And The Importance Of Resistance Training And Protein-Rich Diets For Prevention Of Muscle Loss In Older Adults: A Literature Review And Informational Pamphlet, Madison Steele

Honors Program: Senior Projects (Public)

The growing prevalence of sarcopenia among older adults as well as youths has prompted further research aimed at developing effective preventative measures and treatment plans. Sarcopenia is often thought to occur solely due to aging, but several other factors contribute to progressive muscle loss. Previous research studies have found an effect of physical activity and dietary protein levels on the risk of developing sarcopenia as well as its onset age. This study aims to review existing knowledge in the field to compile an extensive list of sarcopenia causes and methods of prevention. The main causes identified in this review are …

Determining The Impacts Of Corn Silage Mixing Ratios On Hydrogen Production From Beef Cattle Manure, Katya Faber-Quimby

Honors Program: Senior Projects (Public)

With global warming becoming an increasingly serious threat and a growing population requiring additional energy resources, interest in the production of clean energy from the agricultural sector has surged in popularity. Biohydrogen, also known as green hydrogen, is H₂ that has been produced using renewable energy, such as from agricultural byproducts or waste materials. It presents a promising alternative to nonrenewable resources due to its high potential for energy storage and lack of carbon emissions when used. Cattle manure has been explored as a resource for the production of biohydrogen. Selecting for hydrogen-producing microbes in the manure serves the …

Evaluation Of Essential Oils And Their Major Components For Disease Resistance, Serkan Tokgöz

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

Essential oils (EOs) are natural hydrophobic compounds, which are highly complex, typically comprising 20 to 60 constituents, with two or three main components making up 20% to 95% of their composition, alongside other minor constituents. Research has firmly established the potent antibacterial and antifungal properties of EOs and their primary components. To assess their efficacy, one EO, nutmeg oil, and seven main components, including safrole, toscanol, safraleine, cinnamaldehyde, carvacrol, carvone, and thymol, were tested against four economically significant fungal pathogens (Alternaria solani, Fusarium graminearum, Rhizoctonia solani, and Sclerotiorum sclerotiorum), one oomycete pathogen (Phytium ultimum …

Irt-Based Irrigation Scheduling And Dry Bean Crop Water Productivity Under Different Irrigation Scenarios In The Nebraska High Plains, Angie Gradiz

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

Irrigation plays a critical role for crop production in western Nebraska of the United States, where crop evapotranspiration often exceeds in-season precipitation. This study investigated the impacts of different irrigation treatments on yield and key physiological parameters of dry edible beans grown in semi-arid western Nebraska during the 2022-2023 growing seasons. Seven irrigation levels (0%, 25%, 50%, 75%, 100%, 125%, 150%) of the fully irrigated treatment (FIT), were applied using a Variable Rate Irrigation (VRI) Linear-Move Sprinkler System. Additionally, an eighth treatment was scheduled based on measurement from infrared radiometry thermometers (IRT) to evaluate the performance of the two-source energy …

Toxicological Effects And Treatment Of Accidental Ingestion Of Simparica Trio® In Felis Catus: An Investigative Review, Aussia M. Stander

Honors Program: Senior Projects (Public)

Simparica TRIO^®, a canine endectocide manufactured by Zoetis, contains sarolaner, moxidectin, and pyrantel pamoate salt in an orally administered chewable tablet. These compounds are all toxic to both cats and dogs in sufficient amounts. As Simparica TRIO^® rises in popularity among pet owners, Felis catus (felines, cats) in multi-pet households (households with both cats and dogs) are at increased risk of overdosage and toxicosis from accidental ingestion of Simparica TRIO^® due to their smaller weight.

Simparica TRIO^® is not for feline use and little literature exists on the symptoms of and treatment for accidental ingestion …

Utilization Of The NuTrack System To Objectively Evaluate Changes In Active And Passive Behaviors Of Group-Housed Nursery Pigs Exposed To An Endotoxin Challenge, Aaron Holliday

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

This study aimed to evaluate the changes in activity of group-housed, newly weaned pigs challenged with lipopolysaccharide (LPS). At weaning, pigs (n = 192, 5.73 ± 1.8 kg) were stratified by sex, litter, and body weight (BW) and randomly assigned to one of three treatments (16 pigs/pen, 4 pens/treatment): 1) Saline-injected (SAL), 2) 50% challenged [50%-LPS) – only half of the pigs in a pen (8 pigs) were challenged with LPS and 3) 100% challenged (100%-LPS) – all pigs in a pen were challenged with LPS. Pigs in the SAL and 32 in the 50%-LPS treatment received a 3.0 …

Impact Of Strategic Postweaning Supplementation On March- And May-Born Yearling Range Heifer And Calf Growth And Performance In The Nebraska Sandhills, Josie Nicole Crouch

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

Three experiments were conducted at the Gudmundsen Sandhills laboratory near Whitman, Nebraska. Experiment 1, a retrospective regression analysis, evaluated the impact of heifer percentage of mature body weight (BW) at breeding on heifer performance, subsequent pregnancy rates, and calf production. Overall pregnancy rates were greater (P < 0.01) for heifers at 60 to 70% of mature BW than 50 to 55%, with no differences in pregnancy rates (P ≥ 0.15) after 2-years of age. Heifers at 50 to 60% of mature BW had a greater (P = 0.05) proportion give birth in the first 21-d. A higher percentage of mature BW at breeding resulted in greater (P < 0.01) BW at birth and weaning for offspring.

Experiments 2 and 3 were 3-year studies that evaluated the impact …

Artificial Insemination And Fetal Programming In Beef Production Systems, Dempster M. Christenson

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

Pregnancy to artificial insemination and late gestation fetal programming of the next calf crop are central to genetic development, reproductive longevity, calf crop productivity, and efficiency of cow/calf ranching. The purposes of this research are to find methods to improve pregnancy rate to artificial insemination, the growth and reproductive health of pregnant heifers, and the productivity of their offspring. In the first of four studies we found that extending the period of progesterone administration in an estrus synchronization protocol did not significantly hasten estrus response or increase pregnancy rate to artificial insemination, but timing of estrus within the melengestrol acetate …

Feeding Dried Distillers' Grains With Solubles To Lactating Dairy Cattle: Whole Animal Energy Utilization And Manure Biogas Production, Grant Michael Fincham

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

When DDGS are fed to lactating dairy cattle, the observed response in energy supply, milk production, and methane production varies among studies. One potential reason for these observed discrepancies is the nature of the diet formulation itself. Furthermore, little research has been conducted to examine how dietary changes can affect dairy cattle manure composition and methane production in an anaerobic manure digester. In order to gain a better understanding of these topics, we conducted two experiments. The first experiment was conducted to test how the manipulation of lactating dairy cattle diets affects energy utilization, milk production, methane production, and manure …

Implementation And Effectiveness Of Stress Management Strategies Among Stem Students At The University Of Nebraska-Lincoln, Dylan Hiser

Honors Program: Senior Projects (Public)

High-stakes exams often induce significant stress among STEM (Science, Technology, Engineering, and Math) students, impacting their academic performance and overall well-being. As the opportunity for careers in STEM grows rapidly, understanding the stressors that students face remains critical in mitigating the effects of this stress and ensuring the success of these students. The objective of this study is to determine how well STEM students respond to recommended interventions that mitigate exam stress and to identify trends in these students’ exam scores. To accomplish this, a set of surveys was sent to undergraduate STEM students at the University of Nebraska-Lincoln. The …

Numerical Variations In The Thoracic And Lumbar Vertebrae Within The John A. Williams Skeletal Collection, Western Carolina University, Cullowhee, Nc (Usa), Leanna Annette Sanford

Department of Anthropology: Theses and Student Research

This research is on how human variation can lead to the identification of remains based on skeletal variation. The data were collected by performing a morphoscopic trait study of the John A. Williams (J.A.W.) Documented Human Skeletal Collection at Western Carolina University in Cullowhee, NC (USA). Morphoscopic traits are nonmetric traits, visually identified using the knowledge of osteology. The study was performed to study variation of the vertebral column, specifically focusing on morphoscopic traits of the thoracic and lumbar vertebrae. The focus of this research is centralized on the presence of numerical variations in the vertebral column such as eleven …

The Osteobiography Of Human Remains From The Seaview And Indian Town Trail Archaeological Sites, Maggie M. Klemm

Department of Anthropology: Theses and Student Research

Extensive site surveys and excavations on the Island of Barbuda led by Sophia Perdikaris have identified over 62 sites spanning from the Archaic time period to Historic times. Over the last 18 years, these multidisciplinary teams have focused on mapping all sites and performing rescue excavations on sites threatened by sea level rise, erosion or development. Two such sites are the Saladoid site of Seaview (BA016) and the Troumassoid site of Indian Town Trail (BA01). The dunes surrounding the site of Seaview receive the brunt of storms and hurricanes. In 1998 hurricane Georges exposed skeletal material now part of the …

Cultivating Academic Achievement: An Updated Social Psychological Explanation, Maika Malualelagi Tuala

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

This study looks at how income differences affect children's social psychological development, which in turn shapes their academic achievement. Building on theories of social class, cultural capital, and self-concept formation, this dissertation offers a new social psychological model that connects parental SES, concerted cultivation, children's academic mindset and achievement. This new concept called “academic mindset” includes several key social-psychological factors that influence academic performance namely- self-esteem, locus of control, math and reading self-concepts, and educational expectations and values. The study uses data from the Early Childhood Longitudinal Study-1998 Kindergarten cohort and tests the model using multivariate regression analyses. Findings show …

Linking Reactive Nitrogen Species Within The Vadose Zone With Surface Irrigation, Kaitlyn Richards

Honors Program: Senior Projects (Public)

This study investigated the relationship between irrigation methods and the mobilization of nitrogen in the vadose zone, focusing on soil properties, water dynamics, and nitrogen species distribution. Data collected from dryland and pivot-irrigated soil cores reveal distinct patterns in water content, bulk density, soil texture, pH, conductivity, and nitrogen concentrations. Results indicated that water content has a major influence in nitrogen availability and microbial activity. Nitrate-N and ammonium-N concentrations varied between dryland and pivot soils, with notable disparities observed. In dryland soils, nitrate-N concentrations varied widely across depth intervals, with notable accumulation in deeper layers, while ammonium-N concentrations exhibited a …

Overall And Sex-Specific Associations Of Serum Lipid-Soluble Micronutrients With Metabolic Dysfunction-Associated Steatotic Liver Disease Among Adults In The United States, Weiwen Chai, Meng-Hua Tao

Department of Nutrition and Health Sciences: Faculty Publications

This study examined overall and sex-specific associations of serum lipid-soluble micronutrients including α- and γ-tocopherols, 25-hydroxy-vitamin D (25(OH)D), retinol, and six major carotenoids with metabolic dysfunction-associated steatotic lever disease (MASLD) using the 2017–2018 National Health and Nutrition Examination Survey. This analysis included 3956 adults (1991 men, 1965 women) aged ≥ 20 years. Steatotic liver disease was determined through transient elastography examination. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for MASLD associated with micronutrients were estimated using logistic regressions. Higher serum α-tocopherol (highest vs. lowest quartile: OR = 1.53, 95% CI = 1.05–2.22, p = 0.03) and γ-tocopherol (highest …

Accurate Measurement Of Field Size Is Essential For Analysis Of Smallholder Survey Data, Rica Joy Flor, Shen Yuan, Gonzalo Rizzo, Fahmuddin Agus, Anny Ruth P. Pame, Akhara Ouk, Rathmuny Then, Sokheng Keo, Virender Kumar, Particio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Context: Agronomic surveys play a vital role in identifying on-farm yield constraints and opportunities to increase productivity, input-use efficiency, and farmer profit. These surveys typically rely on farmer-reported data, where crop yield and applied inputs per hectare are estimated based on farmer-reported total harvested output and applied inputs per field and associated field size. At question is how accurate field size is, which is vital in the case of smallholders as small inaccuracies can lead to large biases in estimated yield and inputs.

Objectives: The goals of this study are to assess current approaches to determine field size …

Phenotypic Diversity For Morpho-Agronomic Traits In The Us Proso Millet (Panicum Miliaceum L.) Core Collection, Santosh G. Rajput, Rituraj Khound, Dipak K. Santra

Department of Agronomy and Horticulture: Faculty Publications

Proso millet (Panicum miliaceum L.) is a short-season annual crop known for high water-use efficiency and drought tolerance. The low water requirement makes this ancient grain an excellent rotational crop for the winter wheat-based dryland cropping system in theHigh Plains of theUnited States. The genetic base of the commonly grown US cultivars is very narrow. Assessment of proso millet germplasm for agronomic traits is essential for its efficient utilization in the genetic improvement of this crop. The objectives of this study were to (1) characterize the US proso millet germplasm based on nine important morpho-agronomic traits and (2) classify …

Increased Dietary Trp, Thr, And Met Supplementation Improves Performance, Health, And Protein Metabolism Of Weaned Piglets Under Mixed Management And Poor Housing Conditions, Joseane Penteado Rosa Gonçalves, Antonio Diego Brandão Melo, Qinnan Yang, Marllon José Karpeggiane De Oliveira, Danilo Alves Marçal, Manoela Trevisan Ortiz, Pedro Righetti Arnaut, Ismael França, Graziela Alves Da Cunha Valini, Cleslei Alisson Silva, Nate Korth, Natasha Pavlovikj, Paulo Henrique Reis Furtado Campos, Henrique Gastmann Brand, John Kyaw Htoo, João Carlos Gomes-Neto, Andrew K. Benson, Luciano Hauschild

Department of Food Science and Technology: Faculty Publications

A sanitary challenge was carried out to induce suboptimal herd health while investigating the effect of amino acids supplementation on piglet responses. Weaned piglets of high sanitary status (6.33 ± 0.91 kg of BW) were distributed in a 2 × 2 factorial arrangement into two similar facilities with contrasting sanitary conditions and two different diets. Our results suggest that increased Trp, Thr, and Met dietary supplementation could support the immune systems of piglets under a sanitary challenge. In this manner, AA+ supplementation improved the performance and metabolism of piglets under mixed management and poor sanitary conditions. No major temporal microbiome …

Gsl Researcher (Spring 2024)

GSL Researcher

GSL Researcher (Spring 2024)

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Unl Emeriti And Retirees Association Newsletter, Spring 2024

UNL Emeriti and Retirees Association: Newsletters and Other Materials

University of Nebraska-Lincoln Emeriti and Retirees Association Newsletter, Spring 2024

The Effect Of Sample Grinding On Color-Based Predictions Of Soil Organic Carbon, Mason Rutgers

Honors Program: Senior Projects (Public)

Measurements of soil color are widely accessible and can be used as indirect measures of soil organic carbon (SOC). Sensor-based soil color measurements, frequently used in quantitative studies to predict SOC, often use ground and sieved soil samples for color analysis. However, it is unknown whether the extra steps of drying, crushing, and sieving a sample improve the quantitative relationship between color and SOC. This study was conducted to evaluate color-based predictions of SOC using intact, sieved (<2 mm), and fine-ground soil samples from northwest Oklahoma. Moist soil color was measured using Munsell color charts (MCCs) and a Nix Mini 3™ portable color sensor (PCS). The color of the soil samples was measured before processing, after crushing to pass through a 2-mm sieve, and after mechanical grinding to less than 0.25-mm. Using Munsell value (from the MCC) and CIEL* (from the PCS) as predictor variables, regression analyses were conducted to develop SOC predictive functions for each physical state. The resulting coefficients of determination (R2) and root mean squared errors (RMSE) were used to assess model fits for predicting SOC. Model contrasts were calculated to evaluate significant differences between each predictive model. All models exhibited strong relationships (0.56 < R2 < 0.70, 0.20 < RMSE < 0.25) between soil lightness and predicted SOC. Models built using aggregated samples measured with both MCCs (R2= 0.70, RMSE= 0.20) and the PCS (R2= 0.69, RMSE= 0.21) produced the best results. Models built using intact samples measured using the PCS did perform significantly better on samples dark in color (CIEL* < 30). These results suggest that grinding soil samples does not improve color-based predictions of SOC using MCCs and the PCS.

Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #64 Spring 2024

Gamma Sigma Delta, Nebraska Chapter: Newsletters

President-Elect's message, John R. Ruberson

Nominations form for Gamma Sigma Delta, Nebraska chapter

2023 Outstanding Graduate Student Award nominations solicitation

2023 Teaching Award nominations solicitation

2023 Research Award nomination solicitation

2023 Extension Award nomination solicitation

2023 Award of Merit nomination solicitation

Annual dues notice

List of active members with expiration terms

Membership renewal form

Outstanding Graduate and Undergraduate Student Award fund solicitation

In memoriam:

Raymond "Gene" White (October 10, 1930-May 28, 2021)

ΓΣΔ pledge

How College Graduates Decide To Remain In A Rural Community Post-Graduation, Benjamin J. Lamb

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

Rural Brain Drain is a critical issue facing hundreds of non-metropolitan communities across the country. Existing research that addresses the outmigration of college graduates from rural areas primarily focuses on the reasons the graduates leave, and not on what influences the decision making of those who stay. This study adds to existing retention research by; establishing an initial understanding of the influential experiences rural college students have that contribute to their decision to stay in the rural community post-graduation, and providing an emergent theory for practice to help coalitions better assess and strategize efforts to create improved pathways to rural …

Unlocking The Door To Access And Success: The Keys Program, Timothy Paul Barshinger

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

The Keystone Education Yields Success (KEYS) program is a welfare-to-work program in Pennsylvania meant to promote financial independence through education. Across the community colleges in the state of Pennsylvania, the KEYS program has often allowed financially disadvantaged students to succeed on par with—and often surpass—their non-KEYS classmates, defying metrics that typically suggest that low-income students will struggle to succeed. The purpose of this study was to understand how and why the KEYS program at a single community college in Pennsylvania was able to foster that level of success. The study was conducted as an instrumental case study of one KEYS …

Long-Term Soil Change In The Us Great Plains: An Evaluation Of The Haas Soil Archive, Mark A. Liebig, Francisco J. Calderon, Andrea K. Clemensen, Lisa Durso, Jessica L. Duttenhefner, Jed O. Eberly, Jonathan J. Halvorson, Virginia L. Jin, Kyle Mankin, Andrew J. Margenot, Catherine E. Stewart, Scott Van Pelt, Merle F. Vigil

Department of Agronomy and Horticulture: Faculty Publications

Diverse patterns of climate and edaphic factors challenge detection of soil property change in the US Great Plains. Because detectable soil change can take decades, insights into the trajectory of soil properties frequently require long-term site monitoring and, where available, associated soil archives to enable comparisons with initial or baseline states. Unfortunately, few multi-decadal soil change investigations have been conducted in this region. Here, we document effects of dryland cropping on a suite of soil properties by comparing matched historic (1947) and contemporary (2018) soil samples from the Haas Soil Archive at three sites in the US Great Plains: Moccasin, …

Nebraska Women In Agriculture Conference Marks 39 Years, Ryan Evans, Sarah Treffer, Jessica Groskopf

Cornhusker Economics

The Nebraska Women in Agriculture program marked 39 years of educating and empowering females in farming, ranching, and agribusiness, with nearly 380 people attending its annual conference on February 22 and 23, 2024 in Kearney, Nebraska, with a pre-conference session held on February 21. Including 25 workshops, 5 keynotes, and activities to help learn about risk management, farm and ranch improvement, and successful business practices.

Leveraging Digital Agriculture For On-Farm Testing Of Technologies, Laila A. Puntel, Laura J. Thompson, Taro Mieno

Department of Agronomy and Horticulture: Faculty Publications

The Precision Nitrogen Project (PNP) worked with more than 80 corn and winter wheat producers to inexpensively design and implement randomized, replicated field strip trials on whole commercial farm fields, and to provide site-specific testing of current nitrogen (N) technologies. This article proposes a conceptual framework and detailed procedure to select the N technology to be tested; design and implement field trials; generate, process, and manage field trial data; and automatically analyze, report, and share benefits from precision N technology. The selection of the N technology was farmer-driven to ensure a good fit and to increase the likelihood of future …

Honey Bee Colony Behavior And Ontogeny Are Adversely Affected When Exposed To A Pesticide-Contaminated Environment, Rogan Tokach, Autumn H. Smart, Carol Fassbinder-Orth, Chandler Fong, Judy Wu-Smart

Department of Entomology: Faculty Publications

Honey bees exhibit age polyethism and thus have a predictable sequence of behaviors they express through developmental time. Numerous laboratory studies show exposure to pesticides may impair critical honey bee behaviors (brood care, foraging, egg-laying, etc.) that adversely affect colony productivity and survival. There are fewer studies that examine the impacts of pesticides in natural field settings, especially given the challenges of implementing treatment groups and controlling variables. This study helps address the need for impact studies on pollinators under field conditions to assess the consequences of chemical overuse and dependency in agricultural and urban landscapes. To assess the impact …

Association Of Habitual Intake Of Probiotic Supplements And Yogurt With Characteristics Of The Gut Microbiome In The Multiethnic Cohort Adiposity Phenotype Study, Weiwen Chai, Gertraud Maskarinec, Unhee Lim, Carol J. Boushey, Lynne R. Wilkens, V. Wendy Setiawan, Loïc Le Marchand, Timothy W. Randolph, Isaac C. Jenkins, Johanna W. Lampe, Meredith A.J. Hullar

Department of Nutrition and Health Sciences: Faculty Publications

Consumption of probiotics and/or yogurt could be a solution for restoring the balance of the gut microbiota. This study examined associations of regular intake of probiotic supplements or yogurt with the gut microbiota among a diverse population of older adults (N=1,861; 60–72 years). Fecal microbial composition was obtained from 16S rRNA gene sequencing (V1-V3 region). General Linear Models were used to estimate the associations of probiotic supplement or yogurt intake with microbiome measures adjusting for covariates. Compared to non-yogurt consumers (N=1,023), regular yogurt consumers (≥once/week, N=818) had greater Streptococcus (β=0.29, P=0.0003) and lower Odoribacter (β=−0.33, P<0.0001) abundance. The directions of the above associations were consistent across the five ethnic groups but stronger among Japanese Americans (Streptococcus: β=0.56, P=0.0009; Odoribacter: …