Life Sciences Commons^™

Understanding Agricultural Irrigation Practices Along Utah's Wasatch Front Through Farmer-Reported Data, Garland Ledbetter

All Graduate Theses and Dissertations, Fall 2023 to Present

Water is a growing concern in Utah, especially along the Wasatch Front, where cities, farms, and communities all rely on the same limited water supply. Agriculture uses a large portion of the state’s water, so understanding how farms manage irrigation is important for statewide water planning. Utah currently uses a dataset called Water-Related Land Use (WRLU) to estimate agricultural water use across the state. This dataset provides useful information about irrigated land and crop types. However, it does not capture many of the day-to-day decisions farmers make when managing irrigation.

To better understand irrigation practices, this study surveyed 61 farmers …

Understanding And Predicting Precipitation Characteristics In The United States Through Machine Learning, Numerical Modeling And Measurements, Cody Luther Ratterman

All Graduate Theses and Dissertations, Fall 2023 to Present

Precipitation is one of the most important yet uncertain variables in the climate system. It varies dramatically in terms of timing, accumulation, rate, and phase, depending on location, season, circulation patterns, and atmospheric conditions. Precipitation forecasts, especially snowfall, are essential to supporting drought mitigation and water management in the Intermountain West. Because rainfall and snowfall lead to opposite effects on snowpack, accurately partitioning rain and snow is important to estimate snowpack levels, winter recreation, mountain ecosystems and runoff. The research findings in this dissertation have advanced the understanding and prediction of precipitation and snowpack in the U.S. by addressing the …

Integrative Taxonomic Analysis Of Cryptic Species Diversity In The Spiny Witch-Hazel Gall Aphid, Hamamelistes Spinosus (Hemiptera: Aphididae: Hormaphidini) In Eastern North America, Gavin Andrew Powell Munson

All Graduate Theses and Dissertations, Fall 2023 to Present

Taxonomy is the practice of identifying, classifying and categorizing species, providing structure for the vast diversity of life. Aphids are an ecologically important group of soft-bodied insects, but they can be difficult to identify because of their tiny anatomical size, reduced or simplified morphological features, and morphological variation within a single species across different generations. In this study, the taxonomy of the spiny witch-hazel gall aphid, Hamamelistes spinosus, is revised. The complex multi-generational life cycle of the aphids, which alternates between witch-hazel and birch trees, has led to confusion regarding past descriptions. Scientists in the late 1800s who were …

Evaluating Pfas And Marine Microbial Interactions In Estuarine Sediments With Varying Urbanization And Assessments Of Microbial Responses To Pfos, Zachary J. Padgett

All Theses

Per- and polyfluoroalkyl substances (PFAS) are a diverse class of synthetic chemicals that have become globally distributed due to their extensive use in industrial and consumer products and their extraordinary resistance to environmental degradation. Their persistence and documented toxicity have made them a growing concern in coastal environments, particularly in estuaries where urban runoff, wastewater, and industrial discharges concentrate these compounds. Estuaries are unique in that tidal mixing and interactions with fine-grained sediments and organic matter promote PFAS retention, while the microbial communities living directly within estuarine sediments are positioned where PFAS preferentially accumulate, creating conditions for prolonged exposure and …

Understanding The Potential Sources Of Bacteria And Turbidity Pollution In The Edisto Island Watershed, Brynne Sumner

All Theses

Anthropogenic pollution introduces contaminants, such as pathogenic bacteria and turbidity, into coastal watersheds. These contaminants are the major contributors to water quality impairments in the three sub-watersheds encompassing Edisto Island and the Town of Edisto Beach (hereafter referred to as the Edisto Island Watershed), located within the ACE Basin, South Carolina, USA. With 18 locations impaired for fecal bacteria and 19 for turbidity on the 2024 South Carolina 303(d) list of impaired waters, the Edisto Island Watershed offers valuable insights into the water quality challenges rural coastal communities face.

This study aimed to identify the sources of fecal bacteria and …

A Genetic Analysis Of The Rare Endemic Astragalus Ripleyi Barneby, Juan Antonio Jaramillo-Chico

Master's Theses

Astragalus ripleyi Barneby is a rare endemic species found in the San Luis Valley of the southern portions of the Rocky Mountains in Colorado and New Mexico. Though not federally listed as endangered, the species is on the Bureau of Land Management’s Sensitive Species List, warranting protection and continued management. This study aims to provide information about the genetic health of the species to inform conservation efforts and provide updated management recommendations. A genetic health analysis was conducted investigating the levels of diversity present in the species, how genetic diversity is structured across the known range of the species and …

The Effect Of Sustainable 3d Store Design On Consumer Online Shopping Behavior, Sophie G. Roussel

Apparel Merchandising and Product Development Undergraduate Honors Theses

Sustainability has become a significant factor in shaping consumer shopping habits. Companies are implementing 3D store designs to provide a more immersive and interactive experience. Further study is needed to investigate whether a sustainable, green-focused 3D storefront shifts consumers’ satisfaction with online shopping and their intention to buy products from a sustainable store. This study seeks to fill the research gap by examining how sustainable 3D store design influences consumer shopping behavior. Specifically, three distinct 3D store mockups were developed using Visual Retailing (VR) technology. The same number of visually appealing features, products, and store layouts was used to make …

Determining The Role Of Maumee River Sediments In Microbial Nitrogen Transformations And Net Fluxes, Ashlyn Stanalonis

Master's Theses

The Maumee River watershed is the largest of any river feeding into the Laurentian Great Lakes and is primarily comprised of agricultural land uses. Most cultivated crops require fertilizer applications to sustain growth and productivity. Fertilizer runoff is a major source of nutrient loading to the river, and total nitrogen (N) and phosphorus (P) inputs contribute to eutrophication and cyanobacterial blooms in the western basin of Lake Erie. This study aimed to characterize Maumee River sediments as net N sinks or sources to the western basin and evaluate N removal efficiency (a valuable ecosystem service) to determine if river sediments …

Blue Crab Reproductive Output And Phenology In A Changing Climate, Blaise Rohan

Master's Theses

Globally, ecosystems are experiencing rising temperatures due to climate change, with potential consequences for reproductive investment and timing in many species. Blue crabs, Callinectes sapidus, support valuable commercial fisheries throughout the U.S. Atlantic and Gulf coasts, and understanding variation in reproductive output has important management and conservation implications. This study examined two components of blue crab reproduction: (1) reproductive investment across populations spanning multiple latitudes (New York, New Jersey, North Carolina, Mississippi, and Texas), using a space-for-time substitution to assess the effects of varying thermal regimes on fecundity and egg quality, and (2) spawning phenology in North Carolina from …

Genetic Regulation Of Uterine Organogenesis, Diana A. Machado

Dissertations and Theses (Open Access)

In eutherian and marsupial mammals, the site of embryo implantation and gestation is the uterus. The precursor tissue of the uterus, oviducts, cervix, and upper vagina is the Müllerian duct epithelium and its adjacent mesenchyme. Morphological uterine variation between species is established during embryogenesis by species-specific differences in Müllerian duct fusion at the midline, growth, and differentiation. For example, laboratory mice have a bipartite uterus with two uterine horns and a single cervix, whereas humans have a simplex uterus with a single chamber and single cervix. In humans, variations in the fusion process can alter typical uterine morphology, correlating with …

Paleolimnology And Diatom Taxonomy From Lake Tanganyika, Sristika Adhikari

All-Inclusive List of Electronic Theses and Dissertations

Lake Tanganyika is one of the world's largest freshwater ecosystems, supporting rich aquatic biodiversity and providing several ecosystem services to surrounding communities. Environmental changes such as rising lake surface temperatures, pollution, and land-use alterations threaten the lake’s sustainability. This research examines spatial and temporal variations in nutrient dynamics and primary productivity of Lake Tanganyika using diatom assemblages from multiple locations. Our findings indicate reduced nutrient levels and longer stratification periods in the lake’s central basin during most of the Common Era, as indicated by a remarkable increase in the relative abundance of long, needle-shaped planktonic Nitzschia species. In the southern …

Fibrous Protein Biomaterials: Characterization Of Solitary Bee Silk And Cocoons, And Development Of Recombinant Hagfish And Bee Silk Materials, Oran Wasserman

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation explores two complementary aspects of fibrous protein biomaterials: the characterization of understudied naturally occurring solitary bee silk and cocoons; and recombinant expression and biomaterial formation of recombinant hagfish intermediate filaments (rHIF) and a single Osmia lignaria Say (Hymenoptera: Megachilidae) silk protein. Some solitary bee species, which make up about 75% of all bee species, spin silk to construct protective cocoons during development. Despite the importance of silk and cocoons to the solitary bees' life history, their properties remain largely unexplored. This dissertation presents a novel method for isolating and testing individual silk fibers without interfering with the development …

Bridging Animal Production And Human Nutrition: How Production Ecology Shapes The Nutritional Quality Of Terrestrial Animal Foods And Human Omega-3 Status, Joseph Vinod Varre

All Graduate Theses and Dissertations, Fall 2023 to Present

The question at the center of this dissertation is simple: does the way food is produced change the quality of the food itself in ways that matter for human health? Across a series of studies on bison meat, eggs, and human dietary intervention, the answer was yes. This work began with a broad look at the modern food system and the nutritional consequences of industrialized diets. In particular, it focused on the growing imbalance between omega-6 and omega-3 fatty acids in the Western diet. This balance matters because omega-3 fats support heart, brain, and immune health, and diets high in …

Integrating Space Use And Demography To Support Management Of An Endangered Alpine Ungulate, Danielle J. Berger

All Graduate Theses and Dissertations, Fall 2023 to Present

The places animals choose to live affect the food they find, the dangers they face, and the weather conditions they experience. These experiences influence whether individual animals survive and reproduce, which in turn affects the size and health of animal populations. Although scientists have long believed that animal movements play an important role in population trends, there has been limited real-world evidence showing this connection. Advances in GPS tracking technology now allow researchers to follow animals over long periods and better understand how movement influences survival. Using 20 years of GPS tracking data from the endangered Sierra Nevada bighorn sheep …

Carbon Cycling, Salinization, And Long-Term Water Quality Trends In Rocky Mountain Streams, Allyson J. Marrs

All Graduate Theses and Dissertations, Fall 2023 to Present

Humans have greatly affected streams and rivers worldwide through urbanization, agriculture, and water use. The purpose of my dissertation is to increase our understanding of various human impacts on rivers. In chapter two, I aim to determine whether there are differences in greenhouse gas (GHG) emissions between a natural river and manmade canals. I did this by measuring the emissions and dissolved concentrations of three of the most prevalent GHGs, carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O). I found that most of the sites I studied were emitting CO₂ and CH …

Regional Occurrence And Spatiotemporal Habitat Partitioning Of The Culex Genus Mosquitoes In Salt Lake City And Uintah Basin, Utah, Katelyn Graybeal

All Graduate Theses and Dissertations, Fall 2023 to Present

West Nile virus is the most common mosquito-borne disease in North America and can cause serious illness, including inflammation of the brain and nervous system. Because there is currently no widely available vaccine for humans, preventing mosquito bites and monitoring mosquito populations remain the most effective ways to reduce disease risk. Understanding which mosquito species are present, where they occur, and how they respond to environmental change is critical for protecting public health.

This research examined the mosquito species responsible for spreading West Nile virus in Utah through two complementary studies. The first study focused on the Uinta Basin in …

Investigating Recruitment Bottlenecks Of Juvenile Native Fish In The Colorado River Basin, Utah, Anna R. Amidon

All Graduate Theses and Dissertations, Fall 2023 to Present

The first year of life is a vulnerable period for most fish species. Whether young fish survive this early stage determines how many individuals eventually survive and grow into reproductive adults, a process called recruitment. In desert rivers like the Colorado River Basin, native fish evolved alongside extreme natural conditions but now face additional pressure from drought and water storage infrastructure, which alter the shoreline habitats on which young fish depend. Long-lived, migratory native species with complex life cycles are especially vulnerable. We used four decades of monitoring data from the Upper Colorado River Basin to evaluate whether young-of-year (YOY, …

The Influence Of Habitat And Individual Specialization On Mountain Lion (Puma Concolor) Hunting Strategy In A Multi-Prey System, Hannah B. Klugman

All Graduate Theses and Dissertations, Fall 2023 to Present

There is a growing recognition that animal species considered generalists (having a broad and varied diet), are actually specialists, a collection of individuals with different preferences and strategies known as specializations. The diet of a specialist depends on the variety and quantity of available food options, and their own ability to take what they need. Mountain lions (Puma concolor) are known for their ability and tendency to hunt large prey, such as elk (Cervus canadensis) and mule deer (Odocoileus hemionus), but despite the fact they overlap with other potential large prey, like feral horses …

Drought And Diet Breadth: Does Insect Specialization Influence Herbivory When Plants Are Under Stress?, Jakob Palmer

All Graduate Theses and Dissertations, Fall 2023 to Present

Climate change will alter precipitation worldwide, causing more frequent and severe drought events worldwide. Drought affects many ecological processes, including plant-herbivore interactions, which are critical to biodiversity and ecosystem health. A variety of plant characteristics can influence herbivory – such as how hairy, nutritious, or toxic a leaf is – and drought has been shown to alter many of these traits. Unique characteristics of herbivore species are also important: herbivores can either feed on a variety of plants (generalists) or a group of closely related plants (specialists). Specialists can cope with traits of the plants they eat, while generalists are …

Behavioral And Landscape Factors Affecting The Effectiveness Of Egg-Bait Management For Common Ravens In The Great Basin, Usa, Sierra L. Pederson

All Graduate Theses and Dissertations, Fall 2023 to Present

Common Ravens have become increasingly common across the Great Basin of the western USA, largely because human activities, such as roads, agriculture, livestock operations, and human-made structures, provide them with abundant food, water, and nesting sites. As raven numbers have grown, so has their impact on vulnerable species like the greater sage-grouse. Like many other ground-nesting species, greater sage-grouse eggs and chicks are especially susceptible to predation. To help reduce raven numbers in sensitive areas, wildlife managers often place hard-boiled chicken eggs treated with a toxin (DRC-1339) on the landscape, expecting that ravens will die after eating these eggs and …

Analysis Of The Cannabinoid Compositions, Byproducts And Heavy Metals In Unregulated Cannabinoid Products By Hplc-Ms/Icp-Ms, Simone K. Melle

All NMU Master's Theses

The rapid expansion of unregulated hemp-derived products has created a need for analytical methods that characterize both cannabinoid composition and contaminant occurrence. This thesis used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify cannabidiol (CBD), Δ8-tetrahydrocannabinol (Δ8-THC), and Δ9-tetrahydrocannabinol (Δ9-THC), and inductively coupled plasma mass spectrometry (ICP-MS) to measure Al, As, Cd, Cr, Cu, Fe, Mg, Ni, Pb, and Zn in commercial hemp-derived products, laboratory-prepared hemp oils, cultivated hemp tissues, extracted material, and post-harvest soil. Commercial products showed wide cannabinoid variability, with several samples containing more than one target cannabinoid, while laboratory-prepared plant oils showed a more consistent profile dominated by …

Eusocial Caste Specialization Under Abiotic And Biotic Stress In A Stingless Bee, Tetragonisca Angustula, Kristin M. Robinson

Dissertations

Eusocial insects rely on division of labor to achieve high colony efficiency and provide essential ecosystem services, but specialization may also constrain colony resilience when workers operate near their physiological or behavioral limits under abiotic and biotic stressors. How specialization mediates these responses remains poorly understood, particularly in stingless bees (Tribe: Meliponini). Using the agriculturally relevant stingless bee Tetragonisca angustula, which possesses a specialized soldier subcaste, I investigated how a high degree of worker specialization influences physiological tolerance and predator responses across worker subcastes.

In this dissertation, I quantified variation in thermal tolerance and desiccation resistance among worker subcastes …

History-Dependent Gain Control In The Paraventricular Thalamus: Neural Substrates Of Stress-Enhanced Fear Learning, Michael Martino

MUSC Theses and Dissertations

Post-traumatic stress disorder (PTSD) is characterized by hyperarousal and heightened reactivity that generalize beyond the original traumatic event, yet the neural mechanisms by which prior stress experience biases future fear learning remain poorly understood. Stress-enhanced fear learning (SEFL) is a well-validated rodent model of this phenomenon, in which a severe stressor produces persistent sensitization of subsequent fear acquisition. This dissertation used a 30-day SEFL paradigm to identify the brain-wide functional signature of stress sensitization and to identify candidate neural substrates.

Whole-brain cFos mapping during acute fear acquisition revealed a predominant pattern of suppressed neural activity in sensitized animals, with limbic …

Effects Of Photosynthetic Mode On Growth In Closely Related Tillandsia Species, Jeremy L. Read

Electronic Theses, Projects, and Dissertations

To examine the effects of photosynthetic mode (C3 vs CAM) on plant productivity, subjects of the sister taxa Tillandsia confertiflora (a C3 species) and Tillandsia latifolia (a CAM species) were grown under controlled conditions via growth chamber over 30 weeks. These subjects were divided into non-stressed and drought stress groups. Subjects were compared for total biomass gained or lost over the time period as well as physiological stress measures and CAM activity. The primary conclusion is that usage of CAM does not show major differences or tradeoffs for overall productivity. Future work is needed to clarify if this holds true …

A Comparison Of Survival, Growth, And Stress Resilience In Three Different Lineages Of The Pacific Oyster (Crassostrea Gigas) Farmed On The California Central Coast, Victoria F. Hanshaw

Master's Theses

Aquaculture of Pacific oysters on the US West Coast is routinely impacted by seasonal unexplained mortality events. To better understand these large-scale mortality events in oyster aquaculture, shellfish growers and scientists in California have partnered together to conduct comparative, multi-estuary farm trials of discrete Pacific oyster (Crassostrea gigas) lineages. In this thesis we investigate how the more recently imported Midori lineage performs compared to the historically used Miyagi lineage, as well as a Hybrid (Midori x Miyagi) lineage. As part of a 7-month long field study from April-November of 2024 in Morro Bay and Tomales Bay, California, we evaluated …

The Effect Of Specialty Malt On Dry-Hopping, Alexander Kivela

Master's Theses

Dry-Hopping is a modern and ever-increasing method to add hoppy flavors to beer. This is typically seen in pale ales and India Pale Ales (IPA’s). Most research has investigated the effect of dry-hopping only using pale malt, whereas most breweries used specialty malts to create a malty backbone to their beer.

The objectives of this research were to analyze the impact of specialty malts and their concentration on the efficacy of hop flavor and extraction, determined via gas chromatography and sensory analysis. Gas chromatography analysis was modeled after the ASBC Method Beer-48. Sensory analysis was performed via the 15cm line …

Comparative Assessment Of Developmental Fidelity In Hpsc-Derived Neural Crest Cells, Michael H. Zepeda

Electronic Theses, Projects, and Dissertations

Neural crest cells (NCCs) are a transient, multipotent cell population that contributes to craniofacial structures, peripheral neurons, melanocytes, and smooth muscle. Defects in NCC development underlie a broad range of congenital disorders known as neurocristopathies. Human pluripotent stem cell (hPSC)-derived NCCs provide an evaluable model for studying early human development; however, existing differentiation protocols produce variable outcomes, and no standardized method consistently generates high-fidelity NCC populations. To address this challenge, we compared five published hPSC-to-NCC differentiation protocols using the H9 human embryonic stem cell line. We hypothesized that specific protocols more faithfully recapitulate neural crest development through coordinated regulation of …

Analyses Of Atheroprotective Effects From Mir-33a Deletion In Primary Vascular Smooth Muscle Cells, Achala Pokhrel

All Theses

Atherosclerosis is one of the major causes of cardiovascular disease, characterized by the accumulation of cholesterol and foam cells within the arterial walls. Foam cells were traditionally believed to originate from macrophages; however, recent studies have shown vascular smooth muscle cells are also capable of accumulating cholesterol and developing foam-cell-like characteristics. ATP-binding cassette transporter A1 (ABCA1) plays an important role in removing excess cholesterol from cells by transporting intracellular cholesterol to circulatory apolipoprotein A-I (apoAI). MicroRNA-33a (miR-33a) is known to suppress ABCA1 expression and limit cholesterol efflux. However, its role in primary aortic smooth muscle cells is unknown and not …

The Aggregation Of Microplastics By Enhancing Extracellular Polymeric Substance Production In Pseudoalteromonas Sp. Ncimb 2021 To Improve Removal Efficiencies In Environmental Matrices, Janelle L. Mercer

All Theses

Microplastics (MP) are ubiquitous in the natural environment and are a growing threat due to their small size and durability. Plastics are released into the environment through improper waste management, wastewater treatment outfalls, industrial spills, agricultural runoff, and landfills. These particles breakdown into secondary MP through degradation pathways. MP, less than 5 mm, require intricate removal techniques from water systems. Filtration techniques, though viable and effective, have implementation constraints due to high cost, maintenance demands, and filter fouling. By integrating coagulation and flocculation processes prior to filtration, MP removal efficiencies can increase, while minimizing operational challenges during filtration. Extracellular polymeric …

Function And Regulation Of Long Polar Fimbriae During Enterohemorrhagic Escherichia Coli Infection, Walter J. Galdamez

Dissertations and Theses (Open Access)

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that causes severe gastrointestinal disease and hemolytic uremic syndrome. EHEC employs multiple virulence factors to colonize the host intestine, including the locus of enterocyte effacement (LEE) encoded type III secretion system, intimin, and flagella, yet the role of long polar fimbriae (Lpf) in adhesions and infection remains less well understood. Long polar fimbriae can mediate bacterial attachment to host cells in vitro, yet the regulation and function of its two fimbrial operons, lpf1 and lpf2 in vivo remain poorly understood. Preliminary RNA-seq data from zebrafish infected with EHEC reveal that expression of …