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Soybean Cyst Nematode (Heterodera Glycines Ichinohe) Virulence Assay Against Resistance Sources In Nebraska, Pratibha Karki

Department of Plant Pathology: Dissertations, Theses, and Student Research

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe), one of the major yield-limiting pathogens of soybean, is currently found in 60 counties of Nebraska that produce more than 90% of the state’s soybean. Often, yield loss occurs without any above-ground symptoms, which makes it difficult to manage. The primary management option is the use of SCN-resistant varieties. Several soybean plant introductions serve as resistance sources against SCN. Unfortunately, the single source, PI 88788, is used in approximately 90% of resistant varieties and its prolonged use has increased the virulence status of SCN in the U.S. A study was conducted to assess …

Analysis Of Impulsive Differential Equation Models Of Cell Populations Undergoing Radiation Therapy, Abigail D'Ovidio Long

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

Radiation therapy is a mode of treatment which is implemented for approximately 50% of cancer patients. Treatment needs to be able to kill cancer cells, but also do minimal damage to surrounding healthy tissue. We propose two main impulsive differential equation models of radiation therapy to capture the periodic nature of the treatment. These models build off of previous studies using clinical data to ensure biological relevance. The first model incorporates only cancer cell populations, and we provide parameter relationships which theoretically ensure treatment outcomes of cancer eradication, cancer approaching a carrying capacity, and cancer approaching a periodic solution. We …

Local Rural Knowledge And Early Childhood Informal Science Education In Rural Nebraska, Sarah Michelle Paulos

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

This study aims to discover the existing experiences that lead to local rural knowledge (LRK) of specific rural Northeast Nebraska communities. This information will assist in understanding the impact that LRK has on young children’s science knowledge in rural communities. By engaging in hands-on experiences and interactions, science learning goals for children may be achieved and developed through science outreach programs. During Phase 1 of this study, adults in the selected rural communities participated in an online survey indicating their knowledge of various common rural phrases with the option to share personal stories of experiences and family history. This information …

Characterization Of The Final Enzyme In The Coenzyme M Biosynthesis Pathway In Methanosarcina, Connor John Hines

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

Methanogenesis is known to be one of the oldest forms of energy generation on our planet. Methanogens rely on this method of energy conservation and have evolved to metabolize a variety of substrates, including the waste products of other organisms. This feature has made methanogens beneficial to both wastewater treatment and landfill-to-energy projects. Methane itself is a greenhouse gas twenty times more potent than carbon dioxide, viewed as a particularly influential contributor to global greenhouse emissions. Climate change was known to be on the horizon throughout the 20^th century but has made itself known vocally during this 21^{st …}

Investigating The Impact Of An Elaborative Conversation Strategies (Ecs) Intervention On Parent-Child Interactions And Preschool Children's Science Learning Using A Single-Case Experimental Design, Yao Yao

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

The primary purpose of this study was to examine the efficacy of the elaborative conversation strategies (ECS) intervention in improving the quality of parents' science talk during everyday home learning interactions using a single-case experimental design. Specifically, the study explored whether training parents in ECS could increase their use of these high-quality conversation strategies and enhance the quality of their science talk when engaging their children in science activities. The study also investigated how the ECS intervention impacted children's science knowledge, skills, and interest, as well as parents' attitudes toward supporting their children's science learning.

Participants included five typically developing …

Novel Mouse Models To Study The Role Of T Cells In Cardiac Autoimmunity, Meghna Sur

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

Myocarditis patients can chronically develop dilated cardiomyopathy and autoreactive T cells could contribute to the disease pathogenesis, but defining their antigen specificity remains a major challenge. To fill this gap, we generated T cell receptor (TCR) transgenic (Tg) mice specific to cardiac myosin heavy chain (Myhc)-α 334–352 and made a few observations. First, we unexpectedly noted both CD4 and CD8 T cells expressing TCRs specific to Myhc-α 334–352. Second, while Tg T cells from myocarditis-resistant C57BL/6J mice did not respond to Myhc-α 334–352, those from immunized mice responded, indicating that in vivo priming is necessary to break tolerance. Third, upon …

Performance Of Acoustic Telemetry And Space Use Of Pallid Sturgeon In The Lower Platte River, Nebraska, Christopher F. Pullano

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

Pallid Sturgeon (Scaphirhynchus albus) are centenarian, potamodromous, rheophiles that historically occupied the Missouri River and Mississippi River basins. Listed on the U.S. Endangered Species Act in 1990, population declines are attributed to habitat fragmentation and degradation, as well as overharvest, and hybridization. A knowledge gap exists regarding the extent to which tributaries facilitate key life stages for Pallid Sturgeon. This study evaluated the capacity of acoustic telemetry to monitor the movements of Pallid Sturgeon in a shallow, braided tributary to the Missouri River. The specific objectives were to (1) evaluate the environmental variables influencing the performance of acoustic …

Occupancy Of Fish Species Of Greatest Conservation Need And Temporal Patterns Of Assemblage Occurrence In Sandhills Ecoregion, Nebraska Streams, Braxton M. Newkirk

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

Fish species’ occurrence is influenced by environmental conditions across multiple spatial and temporal scales. Alteration to stream systems has the potential to affect occurrence patterns of fish species. Stream systems of the North American Great Plains face threats originating from climate change and anthropogenic activities resulting in negative implications for many fish species. The Sandhills Ecoregion, Nebraska is considered one of the largest intact grasslands in North America, and thus may experience fewer threats than surrounding areas. Stream systems of the Sandhills Ecoregion are home to 12 fish species of greatest conservation need (SGCN). Little context exists regarding the environmental …

Spatial Ecology Of American Bison On Vermejo Park Ranch, New Mexico, Kate Ann Asmus

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

American bison (Bison bison) are a keystone species that impact grassland productivity, plant diversity, and landscape heterogeneity. We used GPS telemetry and a replicate herbivore grazing experiment on Vermejo Park Ranch in northeastern New Mexico to advance understanding of bison spatial ecology and grazing dynamics. First, we evaluated the potentially disparate influences of forage productivity and site fidelity on the size and selection of home ranges of bison. Home range size was strongly negatively influenced by forage productivity. However, home range selection was influenced more strongly by site fidelity than spatial variation in forage, as bison selected home …

The Role Of Disgust In Films: Disgust As An Aesthetically Appreciable Emotion That Enhances The Film’S Other Emotional Effects, Yunyi Zhu

Department of Philosophy: Dissertations, Theses, and Student Research

The goal of this paper is to address the questions: what is the role of disgust in films, or what makes people appreciate a film’s disgusting contents, given that disgust is unpleasant to experience? The films to which I am referring are audiovisual artworks, including both TV shows and movies, that arouse the emotion of disgust and typically have contents that are gory or gross, yet despite their disgusting contents, these films have as a primary goal to present a narrative or an experience rather than merely to disgust or disturb their audiences. This includes various genres of films, from …

Assessing Reproducibility Challenges In Clinical Metabolics, Darcy Lin Cochran

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

Current metabolomics research is expanding to be multiplatform and interdisciplinary. Metabolomic analysis has the potential to provide detailed insight into any biological system of interest to analyze the underlying molecular mechanisms of variables like environment, disease, and genetics. Human clinical metabolomics is a major research area that is often focused on finding biomarkers or panels of biomarkers for different diseases. However, results are difficult to compare across different laboratories since the field of metabolomics has yet to widely adopt best practices for sample preparation, data acquisition and data processing, results are difficult to compare across different laboratories.

This thesis focuses …

Use Of Electrocardiogram To Evaluate Welfare Of Laying Hens And Chicks During Different Life Stages And Events, Ashley Elizabeth Bigge

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

Three separate studies were conducted to evaluate the welfare of laying hens and chicks during different life stages. The stress responses of mature laying hens in two different scenarios were also investigated. All three studies utilized the electrocardiogram (ECG) as the chosen tool for data collection. Study 1 examined the startle response, prompted by an acute stressor that created sudden movement and noise, in White and Brown Leghorn hens housed in either cages or aviaries. The presence of a chronic stressor, a 23-hour feed failure, was also assessed as a factor. These hens had been surgically implanted with wireless ECG …

Examining Factors Of Variance In Energy Metabolism Of Dairy Cattle, Addison Lee Carroll

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

Variation is thought to occur in the use of dietary energy for production in dairy cattle. First, variance can be observed when new methane mitigation strategies are fed resulting in increased H₂ output potentially resulting in downstream effects on estimates heat production via the Brouwer (1965) equation. Therefore, in chapter 3 a review was created to systematically describe the mathematics and theory behind the Brouwer equation, and rederive a heat production equation to integrate H₂ production. Results indicate heat production using the classical Brouwer equation (1965) relative to the rederived equation resulted in an overestimation of heat production …

Microbiome Variation In Production Phenotypes And The Role Of Colonization History In Microbiome Establishment, Seidu Adams

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

Ruminant-based agriculture is expected to continue to be a major contributor to food security to feed the growing population. At the heart of nutrient degradation of complex organic matter within the rumen are its microbes. These microbes can convert otherwise unusable organic matter into usable protein and energy and can provide up to 50% of the animal’s protein needs and up to 70% of the energy needs. The microbial functional capacity within the rumen determines the nutrients utilized and the end products of fermentation. However, our understanding of microbial functional capacity within the rumen and factors that influence the rumen …

Domain-Specific Machine Learning Approaches For Geospatial Problems, Shine Bedi

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

This dissertation explores novel algorithms for complex geospatial problems at the intersection of environmental, social, and computational sciences. Emphasizing the unique challenges of the geospatial domain, particularly the deviation from the independent and identical distribution (IID) assumption, the research spans various methodologies across different domains, demonstrating the benefits of specialized approaches in spatial analysis.

First, we show that machine learning techniques can be effectively used in environmental modeling, which often has severe class imbalance challenges. Using artificial neural networks (ANN), support vector machines (SVM), and extreme gradient boosting (XGB) and techniques to address class imbalance provides insights into groundwater quality …

Motivated By Hope: Why We Strive For The Improbable, Varkey K. Titus Jr.

Department of Philosophy: Dissertations, Theses, and Student Research

Some of the most rewarding actions we take in life are difficult. The outcomes of these actions are surrounded by uncertainty, and what relevant data is available indicates a high probability of failure. Current philosophical work proposes that hope can resolve the puzzle of how people can rationally choose to engage in difficult actions, but this work constrains hope’s motivational role to actions whose successful outcomes reside within the realm of an individual’s own agency. I expand the explanatory role of hope motivating action to include cases whose outcomes depend on some combination of factors internal and external to the …

Gamma Sigma Delta, Nebraska Chapter Newsletter, Issue #66 December 2024

Gamma Sigma Delta, Nebraska Chapter: Newsletters

Nominations Solicitations Issue

President's Message, John R. Ruberson

Members

Grad Student Award

Teaching Award

Research Award

Extension Award

Award of Merit

Annual Membership Info

Student Award Fund

In Memoriam: John L. Lambert (April 25, 1942-July 3, 2024), Larry Elmer Germer (April 24, 1941-October 25, 2024), Leo Lucas (1931-November 13, 2024)

Pledge

Using High-Pressure Processing To Improve The Quality Of Dark-Cutting Beef, Ashley A. Hahn

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

Previous studies have shown high-pressure processing (HPP) can be utilized to improve lean color of dark-cutting beef color by increasing the lightness and redness of steaks. However, the optimal parameters of length of time product is held under pressure and at which pressure must be applied have yet to be fully defined. Furthermore, the impact of HPP on color labile muscles in dark-cutting beef are currently unknown. Therefore, two studies were designed and specific efforts were focused on first defining optimal parameters for color stable muscles, followed by determining the effect of HPP on dark-cutting color labile muscles.

In the …

Relationship Between Host Genomics And Microbiomics In Beef Cattle, Andrew D. Lakamp

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

As sequencing technology becomes more affordable and throughput increases, microbiome information is becoming more readily available. For beef cattle selection, microbial information has a variety of uses including being a target for genetic prediction or used as a means to explicitly describe additional phenotypic variability in other traits.

Infectious bovine keratoconjunctivitis (IBK), commonly known as pinkeye, is a disease that infects the ocular surface and surrounding tissue which is an animal health and producer economic concern. Vaccinations have shown to have variable effectiveness, while limited genetics studies have suggested that direct genetic selection for resistance would be slow. Therefore, an …

Examining Factors Of Variance In Energy Metabolism Of Dairy Cattle, Addison L. Carroll

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

Variation is thought to occur in the use of dietary energy for production in dairy cattle. First, variance can be observed when new methane mitigation strategies are fed resulting in increased H₂ output potentially resulting in downstream effects on estimates of heat production via the Brouwer (1965) equation. Therefore, in chapter 3 a review was created to systematically describe the mathematics and theory behind the Brouwer equation, and rederive a heat production equation to integrate H₂ production. Results indicate heat production using the classical Brouwer equation (1965) relative to the rederived equation resulted in an overestimation of heat …

Impacts Of Annual Forage Management On Grazing Cattle Performance And Carrying Capacity, Shelby Davies Jenkins

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

Rapid conversion of historical grasslands to cropland in recent history has led to limited perennial pasture availability and an increase in cost of pasture rent. Annual forages are an alternative grazing source. Many annual forages can grow and accumulate stockpile following summer harvest of wheat. Strip grazing is often suggested to increase grazing efficiency of stockpiled forages. To evaluate this, a stockpiled mixture of annual forages were either strip grazed or grazed continuously in the fall and winter. The mixture contained oats and rapeseed in the first year and a diverse warm season annual mixture in the second. Strip grazing …

Development Of A Surface-Mounted Strong Post For The Midwest Guardrail System, Gnyarienn Selva Kumar

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

This research investigated the development of a surface-mounted strong post for the Midwest Guardrail System (MGS), designed to replicate the behavior of the standard MGS post, a W6 x8.5, 72-in. long post embedded 40 in. into strong soil. The MGS is a strong post, W-beam guardrail system that has been successfully evaluated in many applications using crashworthiness criteria described in the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). However, in some locations, conventional soil-embedded posts are impossible to install due to subgrade obstructions like concrete slabs, mow strips, utilities, and limited right-of-way. …

Increasing The Impact Of Dietary Fiber From Grains On Human Health Through Gut Microbiome, Sujun Liu

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

The relationship between dietary fiber intake and human health has gained significant attention due to its potential in preventing chronic diseases and promoting gut health. Grains are a primary source of dietary fiber; however, the health impact of grain fibers is often limited because they are incompletely metabolized by gut bacteria. This dissertation explores innovative strategies to enhance the concentration and of dietary fiber from grains and its utilization by gut bacteria. By investigating various treatments, this research aims to maximize the health benefits of grain-derived dietary fibers, thereby contributing to a healthier society.

This dissertation is organized into four …

Finding Them Before They Find Us: Solving The Emerging Infectious Disease Crisis, Daniel R. Brooks

MANTER: Journal of Parasite Biodiversity

The human population grows daily, it’s on the move, and it’s carving a deep technological footprint on our planet. We alter landscapes and perturb ecosystems, inserting ourselves and other species into novel regions of the world, leading to potentially irreversible changes in the biosphere. This is not news. More than 75 years ago, Charles Elton, one of the founders of modern ecology, wrote, “We must make no mistake; we are seeing one of the greatest historical convulsions in the world’s fauna and flora.” We are also in the midst of a public health and epidemiological crisis. Climate change alters movements …

First Records Of The Spider Wasp Entypus Ochrocerus Dahlbom (Hymenoptera: Pompilidae: Pepsinae) From The Continental United States, Jamaica, And The Bahamas, Frank E. Kurczewski, Rick C. West, Dionne Newell, Scott Johnson

Insecta Mundi

A small population of Entypus ochrocerus Dahlbom, a predominantly Greater Antilles spider wasp (Hymenoptera: Pompilidae: Pepsinae), is reported for the first time from the continental United States based on photographs and associated information from iNaturalist.org. The species was initially misidentified online as E. unifasciatus unifasciatus (Say) or Entypus sp. However, Entypus u. unifasciatus individuals from east of the 100th Meridian in the United States typically have melanochromatic (dark) wings with a subapical xanthochromatic (orange-amber) patch. Entypus ochrocerus from Miami-Dade County, Florida is differentiated from E. u. unifasciatus by its black body with dark greenish blue reflections …

First Record Of The Camphor Shot Borer, Cnestus Mutilatus (Blandford) (Coleoptera: Curculionidae: Scolytinae), In Massachusetts, Lawrence E. Barringer

Insecta Mundi

Cnestus mutilatus (Blandford) (Coleoptera: Curculionidae: Scolytinae) is reported from Massachusetts, United States for the first time. Brief trapping information is provided.

Student Comprehension Of Biochemistry In A Flipped Classroom Format, Ed Harris, Evan A. Schroder, Teryn J. Berks

Department of Biochemistry: Faculty Publications

Concept-heavy courses such as Biochemistry in life and physical science curricula are challenging for many college-aged students. It is easy for students to disengage in a lecture and not learn the subject matter while in class. To improve student learning and participation, we employed a flipped format for the first half of the course and compared learning outcomes and attitudes with the traditional lecture in the second half of the course. The experimental course was an upper-level biochemistry course taken primarily by juniors (49%), seniors (40%), and some graduate students (10%) at the college level. Our results indicate that lower-performing …

Small Beef-Packer Resilience During The Covid-19 Pandemic: Evidence And Policy Implications, Azzeddine Azzam, Sunil P. Dhoubadel, Binod Khanal

Cornhusker Economics

As part of a larger research project on the economics of beef supply chain resilience to natural disasters, financed in part by a grant from the USDA National Institute of Food and Agriculture, we obtained information from 289 processing plants across the United States about their operations during the peak COVID-19 period of March to June 2020 via a telephone survey. We collected data on plant type (slaughter, processing, both), the dominant livestock processed by the plant (predominantly beef, pork, poultry, and sheep/goat), plant capacity (maximum and typical capacity in slaughter head/day), age of establishment, and, whether the plant ceased, …

Porcine Peritoneal Macrophages Are Susceptible To Porcine Reproductive And Respiratory Syndrome Virus Infection, Kassandra Durazo-Martinez, Jayeshbhai Chaudhari, Sushmita Kumari, Hiep Vu

Department of Animal Science: Faculty Publications

Previous studies have suggested that porcine peritoneal macrophages (PPMs) are resistant to PRRSV infection, whereas porcine alveolar macrophages (PAMs) are highly susceptible. This contrast is intriguing, as both cell types belong to the same monocyte/macrophage family. The current study aimed to investigate the host factors contributing to the differing susceptibility of PPMs and PAMs to PRRSV infection. We found that PPMs exhibit a higher frequency of CD14+ cells compared to PAMs, suggesting a more immature macrophage phenotype in PPMs. Importantly, PPMs expressed both CD163 and CD169, the key receptors for PRRSV entry, although the frequency and intensity of CD163 and …

In The Case Of Prince Ling Ching: Visualizing The Boxer Rebellion Through Puck Magazine, Mimi Yu

Honors Program: Senior Projects (Public)

Through the framework of orientalism, this paper examines the historicism behind satirical illustrations created by artists and editors in Puck Magazine which depict the Boxer Rebellion, spanning from 1899 to 1902. In doing so, I aim to explore the nuances in which mass-produced visual satire seeks to justify Western hegemony. Widely published and distributed in the United States, Puck was a satirical magazine from the late 19th and early 20th century, and one of the first satirical magazines to contain colored lithographic covers. Puck further contributed to discourse over the “Yellow Peril” by employing caricature art and passages of punchlines …