Life Sciences Commons^™

Ghrelin And Decision-Making: Exploring Its Role In Food Reward, Novelty-Seeking, And Cost Valuation, Serina A. Batson

Open Access Theses & Dissertations

When low energy levels are detected, Ghrelin, a peptide hormone, is produced in the fundus of the stomach. Referred to as the "hunger hormone", Ghrelin is traditionally associated with increased food intake and blood sugar levels. A key modulator in the gut-brain interaction, Ghrelin's growth hormone secretagogue receptor can be found widely across the cortico-striosomal circuit. Critical for decision-making, Ghrelin-based manipulation of this circuit can directly affect reward and cost valuation. While Ghrelin is uniformly considered to increase the valuation of food-based rewards, little research has explored its impact on non-food-based rewards or its effects on cost valuation. Therefore, to …

Translation Of The Carcinogenic Dna Breakage-Repair Inhibition Mechanism For Hexavalent Chromium To Its Key Targets: Lung Epithelial Cells, Lung Tissue And Impacts On The Genome., Idoia Meaza Isusi

Electronic Theses and Dissertations

Lung cancer is the leading cause of cancer death worldwide. Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread occupational and environmental exposure. Despite the known health risks, how Cr(VI) causes lung cancer remains unclear. This dissertation investigates the mechanisms of Cr(VI)-induced carcinogenesis. Cr(VI) causes DNA damage, specifically DNA double strand breaks, and inhibits homologous recombination repair, a high-fidelity repair pathway. Unrepaired DNA double strand breaks or those repaired through error-prone pathways, progress to chromosomal damage, and chromosome instability. The latter is a common characteristic of Cr(VI)-exposed cells, and a hallmark of lung cancer. Although the mechanism of Cr(VI)-induced …

The Effects Of Geographic Isolation And Anthropogenic Activity On The Social Behavior Of Caribbean Green Monkeys., Rose Amrhein

Electronic Theses and Dissertations

Green monkeys (Chlorocebus sabaeaus) arrived to the Caribbean with the Trans-Atlantic slave trade. Since then, they have experienced unique environments to those of their native ranges in West Africa. Additionally, recent taxonomic changes within the genus make previous knowledge about the species hard to determine to be accurate. In this dissertation, I both assess some of the effects the island environment may have had on monkey behavior as well as build on the understanding of their vocal communication across three islands: Barbados, St. Kitts, and St. Martin. In chapter one, I investigate how human activity in Barbados affects …

Dirty Dianthus: A Review Of The Microbotryum-Dianthus Plant Pathogen System., Roxanne Kaaren Hayes

Electronic Theses and Dissertations

Microbotryum dianthorum is a species complex of smut fungi that act as biotrophic plant pathogens of Dianthus flowering plants. This group of pathogenic fungi are situated within a larger group of fungi that act as biotrophic plant pathogens, some of which are responsible for extensive crop loss in our agricultural system. These pathogens are distinct from other Microbotryum species in their ability to infect not only a single host, but multiple hosts. Their unique ability to parasitize several plant hosts may unlock potential clues about the potential for emergent infection disease in crop systems. Previous work has established that these …

Sars-Cov-2 Modulates Pla2g2d/Pgd2 Signaling To Manipulate Host Immune Response To Increase Disease Severity., Dante L. Hamiel

Electronic Theses and Dissertations

Background: Previous studies suggested that SARS-CoV-2 infection could cause diverse immune and metabolic dysregulations, although the underlying mechanisms remain poorly understood. In addition, viruses may escape the immune response by modulating cellular metabolism, mitochondria, and protein functions indicating that immune or metabolic components may represent novel targets for anti-viral strategies. However, whether immune and metabolic disorders interact or affect each other waits to be determined. On the other hand, previous investigations identified the critical roles of a cell membrane-bound phospholipase PLA₂G2D and its downstream products PGD₂ in regulating the metabolism and inflammation in respiratory system. More importantly, …

Fc Gamma Receptors Facilitate Antigenic Modulation Of Lilrb4 And Function As Predictive Biomarkers In Acute Monocytic Leukemia, Joshua Morse

Dissertations and Theses (Open Access)

Acute monocytic leukemia (monocytic AML) is a subtype of AML marked by a proliferation of abnormal monoblasts. This subtype represents approximately 10% of AML cases. The prognosis of monocytic AML is poor, with a 5-year survival of ~30%. Most patients are diagnosed at an age when they are unlikely to survive first-line non-targeted cytotoxic chemotherapy as a bridge to hematopoietic stem cell transplant (HSCT). Even patients who achieve remission commonly relapse. This population of patients would greatly benefit from precision-targeted therapies but currently there are none approved for monocytic AML.

Leukocyte immunoglobulin-like receptor B4 (LILRB4) is an immune checkpoint expressed …

Expanding Inducible Epithelial Resistance Against Pneumonia: Novel Virus, Novel Receptor, Michael Longmire

Dissertations and Theses (Open Access)

Pneumonia is the leading infectious cause of death worldwide and presents a continuing risk among immunocompromised patients. Our work has been focused for many years on the phenomenon of inducible epithelial resistance, where activation of the innate immune response in the airway epithelium is necessary and sufficient to produce a pathogen-killing but self-protective environment to prevent severe disease. Inducible resistance is pathogen-agnostic and has been demonstrated against an array of respiratory infections. We achieve this using a combination of pattern recognition receptor agonists – Pam2CSK4 and ODN M362 being the current formulation – which produce synergistic levels of pathogen reduction …

Development And Functional Characterization Of Carbon Nanodot-Peptide Conjugates For The Treatment Of Bone Disease, Abigail Ali

Honors Theses

Carbon nanodots (CDs) synthesized from carbon nanopowder under acid oxidative conditions have unique bone-bind properties that could be exploited for theranostic purposes. In the zebrafish vertebrate model system, CDs bind to bone with high affinity and specificity, they don’t appear to bind to other tissues and they do not affect the bone physiology or animal viability. Thus, carbon-derived CDs could be developed for the delivery of pharmacological agents to bones to treat diseases such as osteoporosis. Biologicals such as peptides, proteins and antibodies are a new and exciting class of pharmacological agents that have been successfully used in treating complex …

A Cross-Taxa Comparison Of Avian Telomere Dynamics, Age, And Lifespan, Benjamin Konigsberg

Honors Theses

When eukaryotes replicate cells throughout their life, the end regions of chromosomes naturally degrade as a result of the 5' to 3' directionality of DNA polymerase. There is a point when the chromosome is too damaged to provide normal cellular functions, so the cell will die. Telomeres act as a buffer by providing repetitive sequences of non-coding nucleotides. While telomeres do shorten during replication events, the enzyme telomerase can extend telomeres to prevent senescence. Telomere lengths vary between individuals based on different stressor and stress mitigation. Telomeric rate of change is a metric that can capture telomerase activity by measuring …

Isolation And Identification Of Active Antimicrobial Compounds In Alcaligenes And Chromobacterium Strains, Hannah Lwin

Honors Theses

ESKAPE pathogens comprise six bacteria that can be highly virulent and are likely to develop antibiotic resistance to many of the currently available antibiotics. New antibiotics are needed to combat these pathogens. Our approach was to isolate and identify antimicrobial compounds from bacteria isolated from soil. Two isolates demonstrating antimicrobial activity were identified as Chromobacterium sp. and Alcaligenes parafaecalis. Preliminary extraction of their antimicrobials was performed.

Identifying Microbial Complexities And Control Strategies At Pre-Harvest Poultry Production, Tolulope Tiwa Ogundipe

Graduate Theses and Dissertations

While significant progress has been made in post-harvest control of Salmonella in the poultry industry, the development of effective pre-harvest intervention strategies remains critical for reducing foodborne pathogens. Environmental reservoirs such as poultry litter and drinking water systems (DWS) are potential harborage sites for Salmonella and other microbial communities. Understanding the microbiota of these environments, including biofilms within water lines, is essential to identifying factors contributing to Salmonella colonization and improving pre-harvest control approaches. This study aimed to evaluate the incidence and quantity of Salmonella in poultry litter and water lines, characterize the microbial populations in these environments, and assess …

Quantification Of Blue Carbon Within The Marine Animal Forest On The Rio Grande Valley Artificial Reef, Michelle Kathryn King

Theses and Dissertations

The protection and enhancement of coastal ecosystems provides a number of benefits such as heightened biodiversity, increased fisheries, and enhanced carbon capture (Yeemin et al., 2024). The study of blue carbon ecosystems has expanded rapidly in the last two decades since the term was coined in 2009 (Lovelock & Duarte, 2019). The most well-known blue carbon ecosystems include vegetation-dominated ecosystems such as seagrass meadows, salt marshes, and mangrove forests (Howard et. al., 2014). Prior studies have overlooked Marine Animal Forests (MAF) ability to capture carbon, until recent studies on soft coral (Coppari et al., 2019) and sponge (Rix et al., …

Patterns Of Fire History And Vegetation Changes In The Last 5000 Years: A Paleoecological Study Of Iquitos, Annabel Zwarts

Theses and Dissertations

The vegetation of the Amazonian rainforest is hypothesized to have been shaped by pre-Columbian activities, such as burning and palm management to various extents. Management of palms is hypothesized to have caused some of the most useful species to become hyperdominant in Amazonia. This study investigated the extent to which human activities over the past 5000 years affected palm abundances in mature lowland rainforests near Iquitos, Peru. I used phytoliths and charcoal from soil cores to determine the history of local floras, and modern palm surveys to compare modern phytolith occurrence with modern vegetation. Because pre-Columbian activity clustered along the …

Targeting Bard1 Suppresses A Myc-Dependent Transcriptional Program And Tumor Growth In Pancreatic Ductal Adenocarcinoma, Sohum Patel, Eleanor Jenkins, Rutuj P. Kusurkar, Sherry Lee, Wei Jiang, Avinoam Nevler, Matthew Mccoy, Michael J. Pishvaian, Rosalie C. Sears, Jonathan R. Brody, Charles J. Yeo, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers demanding better and more effective therapies. BARD1 or BRCA1-Associated -Ring Domain-1 plays a pivotal role in homologous recombination repair (HRR). However, its function and the underlying molecular mechanisms in PDAC are still not fully elucidated. Here, we demonstrate that BARD1 is overexpressed in PDAC and its genetic inhibition suppresses c-Myc and disrupts c-Myc dependent transcriptional program. Mechanistically, BARD1 stabilizes c-Myc through ubiquitin-proteasome system by regulating FBXW7. Importantly, targeting BARD1 using either siRNAs or CRISPR/Cas9 deletion blocks PDAC growth in vitro and in vivo, without any signs of toxicity to mice. …

Risky Genes: The Impact Of Social Determinants Of Health On Dna Methylation In Indigenous Communities, Ella Martin

Celebrating Scholarship and Creativity Day (2018-)

Epigenetics is the study of molecular modifications to DNA structure that do not impact the sequence of the DNA itself. This biological study works to link health outcomes later in life with environmental interactions that affect our genetic predispositions. These complex factors can greatly impact longevity and quality of life. DNA methylation is one type of epigenetic mark that happens through natural biological processes. However, this marking has been shown to be detrimental to the process of aging and can be accelerated by harmful exposures such as stress, substance-use, or chemicals in the environment. Exposure to these compounds is exasperated …

Assessment Of Dose-Dependent Cytotoxicity Of Caffeine On Human Colorectal Adenocarcinoma And Foreskin Fibroblast Cell Lines, Sanjay Srinivasan

Theses/Capstones/Creative Projects

Caffeine is a stimulant well-known for its alertness enhancement and energy functions. Beyond its neurological effects, caffeine also influences cellular qualities, including viability and membrane integrity. This study aimed to investigate the cytotoxic effects of caffeine on two distinct human cell lines: Human Colorectal Adenocarcinoma (HT-29) and Foreskin Fibroblasts (HFF). Cells were exposed to varying concentrations of caffeine to evaluate whether its effects were dose dependent. Cell viability was assessed using the Trypan Blue exclusion and Alamar Blue assays. Results showed that HFF cell death was more evident than the HT-29 Cells, displaying a potential therapeutic for cancer treatment.

Gender And Race Stigma Consciousness Denialism And Reactions To Race And Gender Measures, Valerie Partida, Alicia Sylvester, Magel Baker

Celebrating Scholarship and Creativity Day (2018-)

The study examined whether denialism, defined as holding problematic stigma consciousness scores in, predicts emotional reactions to race- and gender-related survey measures. Specifically, we asked whether race stigma consciousness scores correlate with feeling upset when completing race scales, and whether gender stigma consciousness scores correlate with either positive or negative reactions to gender scales. Undergraduate students in introductory psychology courses participated (N = 38; 61 % women/gender minority, 39 % men; 21% POC, 79% White). Measures of students’ awareness of racial and gender discrimination (Pietri et al., 2018) were scored such that high scores meant that students of color (POC), …

The Effect Of Calorie Restriction On Humoral Responses Towards The Influenza Vaccine, Grayson Kobluk

Celebrating Scholarship and Creativity Day (2018-)

Calorie restriction (CR) - a reduction in caloric intake without malnutrition - has been widely studied for its impact on lifespan and the onset of age-related diseases. Emerging research indicates that CR also influences immune function, though its effects can vary depending on the degree of restriction, duration, and individual characteristics. This study examined how CR effects vaccine-specific antibody responses following influenza vaccination. Male and female mice were maintained on either a control diet or a calorie-restricted diet and vaccinated with an inactivated influenza virus vaccine. Antibody titers were measured 28 days post-vaccination to evaluate the magnitude of the humoral …

Effect Of Glycation On The Binding Interactions Of Serum Albumin And Silver Nanoparticles, Megan Kirk

Celebrating Scholarship and Creativity Day (2018-)

Nanoparticles are particles ranging from 1-100 nanometers in size. Most nanoparticles, upon contact with biological matrices, are immediately coated with proteins, forming the protein corona, which can alter the structure and function of proteins. Despite the tremendous advancement of nanotechnology over the last decade, the interactions of nanoparticles with proteins are not well characterized. This project investigates the effect of glycation on the binding interactions of HSA, the most abundant protein in human blood, with silver nanoparticles using various spectroscopic techniques. This is important because in diabetic patients, HSA is exposed to high concentrations of glucose over extended periods of …

Life In Plastic? Not So Fantastic: Marine Plastic Pollution On San Salvador Island, Dayna Wiley

Celebrating Scholarship and Creativity Day (2018-)

Marine plastic pollution, also known as marine macroplastic debris (MMD), impacts many aspects of marine ecosystems. MMD is defined as macroplastic (> 5mm) objects that are deposited in the ocean and are found floating in the water column or washed up on beaches. MMD washup is significantly affected by ocean and wind currents. The Antilles Oceanic Current and the Trade Winds move west across the Atlantic Ocean, and thus were predicted to cause more MMD deposition on the eastern side of San Salvador Island, Bahamas. Beaches on the North (Graham’s Harbor), South (French Bay), East (East Beach), and West (Columbus …

Exercise Physiological Insights Into Exercise-Induced Muscle Cramping: Blood Lactate And Creatine Kinase As Biomarkers In College Students, William Yu

Celebrating Scholarship and Creativity Day (2018-)

Creatine kinase (CK) is an enzyme that's found in the skeletal muscle, heart muscle and brain. When any of these tissues are damaged, they leak creatine kinase into your bloodstream. Elevated CK levels may indicate muscle injuries, cramping, or disease1. There are different types of CK, which are also known as isozymes for the cytoplasm, CK-MM, CK-MB, and CK-BB. CK-MM focuses on musculoskeletal, CK-MB focuses on heart muscles, and CK-BB focuses on the brain tissue. There are also two isozymes in the mitochondria15. Cramping is common problem amongst runners and can be described as “painful, spasmodic contraction of the skeletal …

The Effects Of Climate Change On The Spread Of Mosquito-Borne Diseases, Lauren Provoncha, Sarah Franta, Portia Lawrence

Celebrating Scholarship and Creativity Day (2018-)

This paper examines the impact of climate change on the spread of mosquito-borne diseases, focusing on how rising temperatures, altered precipitation patterns, and extreme weather events influence mosquito habitats and disease transmission. It explores the ecological and public health implications of these shifts and highlights the importance of understanding climate-disease dynamics to inform effective prevention and intervention strategies.

Ecological Consequences Of Variable Glacial Melting On Arctic Biodiversity: Trophic Shifts And Community Dynamics, Aislyn Malone, Audrey Swart

Celebrating Scholarship and Creativity Day (2018-)

Our project investigated the profound impacts of increasing glacial melting on various trophic levels, habitats, and other ecological processes.

An Empirical Study On The Economic And Policy Drivers Of Livestock Risk Protection Utilization, Milan Chauhan

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

Federally supported risk management programs for livestock producers have existed for the last twenty years. Among these, Livestock Risk Protection (LRP) is a federally subsidized insurance tool available for cattle producers to manage downside price risk. In recent years, participation in LRP has surged. This paper examines the key economic and policy variables that partially drive LRP utilization and analyzes the role of risk management educational efforts in the decision to participate and the intensity of the insurance utilization using unique state-level panel data from 2003 through 2023.

The study analyzes three complementary metrics of insurance utilization: market volume (policies …

Evaluating Risk And Return Of Corn And Soybean Marketing Strategies Using Monte Carlo Simulation Methods, Johanna Ilves

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

This study evaluates the performance of pre-harvest marketing strategies for corn and soybeans, using Monte Carlo simulation techniques. Given the increasing volatility in commodity prices and the evolving landscape of agricultural markets, producers face growing challenges in developing effective marketing plans that manage risk and enhance profitability. This thesis examines thirteen marketing strategies from 2008 to 2024, including benchmark harvest-only sales and various pre-harvest futures contract approaches. Historical futures price data for December corn and November soybean contracts were used to simulate 1,000 marketing outcomes per strategy per year, capturing a broad range of market conditions. Key performance indicators such …

Walleye And Sauger Movement And Entrainment In Lewis And Clark Lake, William Joseph Radigan

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

Walleye Sander vitreus and Sauger Sander canadensis are both socioeconomically important sportfish species in Lewis and Clark Lake, an interjurisdictionally managed mainstem Missouri River reservoir fishery. Since 2011, adult catch per unit effort (CPUE) of both Walleye and Sauger has remained at approximately 50% of pre-2011 levels. A presumed reason for the suppressed CPUE of adult Walleye and Sauger is substantial entrainment of larval and adult fish resulting from the reservoir’s high turnover rate (7.2 d). Acoustic telemetry was used to quantify adult movement and entrainment and ichthyoplankton trawls were used to assess larval entrainment. Relative importance of factors driving …

Illustrating Insects: Using Art To Encourage Experiences In Entomology, Nia Kaufmann

Honors Program: Senior Projects (Public)

The goal of this creative project is to use art to highlight the diversity of our insect neighbors and encourage others to explore their local environments. In order to accomplish this, I created a poster-sized illustration of five insects I’ve encountered on the University of Nebraska-Lincoln’s City Campus. All insects are posted within the silhouette of Memorial Stadium, each with an ecological and personal significance. The contrast of a well-known building with less popular insects invokes the audience to reconsider how much attention they pay to the wilderness around them.

Keywords: Entomology, Natural Biodiversity, Illustration, Insects, Appreciation of Nature

Parasitic Effects Of Amoebidium Appalachense On Daphnia Magna Heart Rate, Hopping Frequency, And Metabolic Rate, Vanessa Wise

Honors Program: Senior Projects (Public)

Daphnia magna are a crustacean that inhabits multiple different types of freshwater ecosystems and thus is plays a part in many different types of interspecies interactions, one of which is parasitism. Amoebidium appalachense is a Mesomycetozoean parasite of aquatic arthropods that colonizes the antenna of D. magna. Previous research has shown that A. appalachense infection will reduce the fecundity and increase mortality rate of D. magna but how it causes these effects is unknown. To determine if A. appalachense causes these effects on D. magna by either stealing nutrients inside the D. magna like a tick or by compromising …

Landscape Effects On The Beneficial Arthropod Community In Agriculturally Dominated Environments, Hannah E. Stowe

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

Ecosystem services in agriculturally dominated regions rely, at least in part, on arthropods. Environment and biodiversity influence beneficial arthropods in population size, community structure, diversity, and ecosystem service provisioning. Predation is among the most important services provided by arthropods in agroecosystems. Understanding what alters predation and predator activity can support the successful application of biological control and, more broadly, integrated pest management. Land use and edge adjacency, field characteristics, landscape, seasonality, and diel period all alter predatory behavior. Crop fields dominate Nebraska agroecosystems, although interspersed perennial grasslands persist through the Conservation Reserve Program (CRP). Such grasslands supply crucial resources and …

A Case Study On Readiness Of Engineers In Agricultural Technology Start-Ups, Katie Marie Mowat

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

This dissertation explores the perceptions of practicing engineers regarding the skills necessary to be workforce-ready at agricultural technology (ag-tech) start-ups in the Midwestern United States. A qualitative case study methodology is leveraged, combining both interview and job description data. Given their uniqueness, the study divides the ag-tech start-up industry into two subcases: livestock and cropping systems. The Work Readiness Integrated Competence Model (WRICM) is used as the theoretical framework for this study and informs the conceptual framework and analysis processes. The study identified skills that fit into thirteen distinct categories, which are further grouped into four overarching resource groups. Skills …