Life Sciences Commons^™

Physiological Consequences Of Adrenal Enlargement And Implications For Toxin Resistance In North American Snakes, Megen E. Kepas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long observed relationship between enlarged adrenal glands and toad-eating in snakes has remained a mystery in physiological ecology and herpetology. It has been predicted that large adrenal glands may be capable of producing higher amounts of key hormones, and that higher plasma hormone levels may lend some behavioral or physiological benefits after a toxic toad has been eaten. I address questions surrounding adrenal enlargement and its potential benefits to toad eaters in four research chapters. In my second chapter, I quantify adrenal hormone output at different embryonic stages in the toad-generalist snake Thamnophis elegans and examine the ability of …

Anthropogenic Factors Affecting Common Raven Occurrence And Depredation Of Artificial Nests Within Greater Sage‐Grouse Habitat In Southern Utah, Zoë S. Moffett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain species of wildlife are more generalist and adaptive than others. These species often flourish when supported by human activities that provide additional food and habitat for them. The common raven (Corvus corax; hereafter raven) is one such species; their populations have risen and spread throughout the Intermountain West. As generalist scavengers and predators, ravens have been found to pose a severe threat to several threatened or sensitive species, including the greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse). The purpose of my research was to determine the specific anthropogenic and habitat factors that may increase the threat …

Antimicrobial Peptides In Transgenic Silkworm Silk, David Jaden Turner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Overview: People in India and China have produced silk textiles for thousands of years. Silk is a biodegradable, biocompatible compound used in the production of clothing, bedding, furniture, industrial materials, and medical applications. Over the last 30 years, research has increasingly investigated silk’s antimicrobial effects and how to augment its natural abilities. Antimicrobial peptides, or AMPs, are also an area of increasing interest as the rise of antibiotic resistance reduces the efficacy of current treatments. This project plans to systematically synthesize a fusion protein that incorporates the beneficial properties of each constituent into commercial silkworms.

Innovation: This project seeks to …

Fishing Out Nutrients: The Spatiotemporal And Ecological Dynamics Of Fishery-Based Nutrient Extraction, Adrián A. González Ortiz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Marine fisheries are one of the most impactful human activities on the planet. Since the 1950s, marine fisheries have removed billions of metric tons of marine biomass leading to substantial declines in many fish populations. Among their impacts, we have begun to investigate the role of fisheries in disrupting marine nutrient cycles. Specifically, removing biomass can change nutrient cycles by reducing the amount of nutrients stored within animal biomass.

No studies have investigated the large-scale geographical and ecological contexts of nutrient removal by fisheries over a large timescale. For my thesis, we compiled data on fishery-targeted organisms' carbon, nitrogen, and …

Evaluating Beaver Translocation Methods For Desert River Restoration, Christine E. Sandbach

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife translocation, or moving wild animals from their original home to a new location, is a common conservation practice; however, translocation programs have variable success rates. Beaver translocation is often used in stream restoration projects due to beavers’ role as ecosystem engineers—beavers enhance riparian habitat by building dams that hold water and create more diverse channels. Beaver translocation success is often limited by high mortality and long distance movement after release, and improvement in translocation methods is needed. My objective was to evaluate two methods of improving beaver translocation success in a degraded desert river in east-central Utah: beaver dam …

Treatment Of Yellow Fever Virus With The Ns4b Inhibitor Bdaa And Effects On Rna‐Sensing Innate Immune Pathways In Hamster And Mouse Models, Abbie E. Weight

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Yellow fever (YF) is an acute and often severe disease cause by yellow fever virus (YFV). Although there is an effective vaccine available to prevent YF, there are no antiviral drugs approved to treat the disease, which has a considerable disease burden in endemic areas of South America and Africa. BDAA is an experimental antiviral treatment which has shown efficacy against YFV both in cell culture and when administered before infection in an animal model of disease. BDAA targets the YFV protein NS4B and has two reported mechanisms of action: the primary mechanism of action is the direct inhibition of …

An Evaluation Of Stress Tolerance In Restoration Plant Species In Response To Fire, Drought, And Invasive Plants Through The Lens Of Functional Traits, Adam M. Clifford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush communities in the Great Basin face many threats. Cheatgrass, a winter annual from Eurasia, has invaded these communities, increasing wildfire and lowering species diversity. Additionally, climate models project warmer and drier conditions throughout much of the Great Basin, likely increasing drought, cheatgrass invasion, and wildfire. Intact stands of native and introduced perennial grasses have been shown to limit invasion by cheatgrass and restore ecosystem functions. The objective of this research was to identify the functional traits and growth characteristics needed by restoration species to survive periods of drought and to evaluate varieties of commonly used restoration species for establishment, …

Consumption Of A Western Diet Enhanced Colitis-Associated Colorectal Cancer And Dysbiosis Of The Fecal Microbiome In Mice Notwithstanding Dietary Intervention Or Fecal Microbiome Transfer, Daphne Michelle Rodriguez Jimenez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In a rodent model of inflammation-associated colorectal cancer, consumption of a Western-style diet increases gut inflammation and enhances risk of developing colon tumors. The goal of this dissertation was to understand the contribution of bacteria within the large intestine on colon inflammation and colon tumorigenesis. Two pre-clinical animal studies were performed using two different intervention strategies to shift the microbiome, and potentially gut inflammation and tumor development: 1) an experiment using dietary supplementation with black raspberries, a functional food enriched in bioactive anthocyanins with purported antiinflammatory activity, and 2) an experiment using fecal microbiota transfer from mice fed a healthy …

Multispecies Genomic Sex Identification Using Ddx3 Gene Polymorphisms, Jessica Felts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

PCR sex determination assays must be reliable and cost effective due to the frequent and integral use of these assays in biological research and the animal production industry. Thus, the design of proof of a primer pair with a built-in control is warranted to not only bypass the extra cost of a multiplex reaction, but also to prevent anomalous results that have been documented with other primer pairs.

The objective of this study was to design primer pairs with built in PCR amplification control to identify sex in Equus caballus (domestic horse), Homo sapiens (humans), Macaca mulatta (rhesus macaque), and …

Investigating Mitochondrial Influence On The Rate Of Anaerobic Glycolysis In An In Vitro Model, Mackenzie Jenna' Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The rate at which the muscle acidifies after an animal is harvested has a profound effect on the quality of the resulting pork. When acidification increases gradually, desirable pork quality characteristics are developed. In contrast, rapid acidification deteriorates pork quality, exemplified by the pale, soft, and exudative (PSE) pork defect. The rate of acidification is determined by the rate of anaerobic metabolism in postmortem muscle. Yet the processes controlling postmortem anaerobic metabolism are not well understood. Recent research suggests that mitochondria, the powerhouse of the cell, may influence this process by competing for substrate (pyruvate) with anaerobic metabolism, thereby reducing …

Water Conservation Through Drought-Resilient Landscape Plants And Deficit Irrigation, Ji-Jhong Chen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increases in urban population and inadequate rainfall result in imbalanced water budgets in urban and sub-urban regions. Water conservation becomes important in urban landscapes because of increased water demands. Modern landscape designs require drought-resistant plants to maintain urban landscape greenness during water scarcity. Irrigating plants at their irrigation requirements, which is the minimum irrigation rate that can achieve acceptable aesthetic quality, can also conserve water. However, the drought tolerance and irrigation requrements of most landscape plants have not been widely evaluated. Shepherdia ×utahensis ‘Torrey’ (‘Torrey’ buffaloberry) and Penstemon species (beardtongues) are low-water-use landscape plants, but their drought resistance mechanisms are …

Precipitation And Soil Properties Determine Long-Term Consequences Of Disturbance And Invasion In Drylands, Tyson Terry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Disturbance and invasive species have dramatic effects on desert plant communities, often resulting in degradation or shifts to alternative plant communities. Climate and soil properties determine water availability to plants, and have been thought to drive patterns of recovery following disturbance and potential for invasion.

In chapter II we used a combination of natural gas pipelines and satellite imagery to understand how recovery from a uniform disturbance differs across precipitation and soil gradients. We used a recovery ratio (disturbed/undisturbed) of pipeline pixels and their undisturbed nearest neighbor pixel to quantify recovery in a comparable way across precipitation gradients. We found …

Opening The Black Box: Soil Microbial Communities In Field-Based Plant-Soil Feedback Experiments, Julia Kate Aaronson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant-soil feedback is a process through which plants modify the properties of their associated soils, affecting their growth. PSF can play a key role in regulating plant growth and communities including altering plant invasion, rarity, and abundance. However, our understanding of the soil organisms that drive these plant growth responses is limited. Most studies treat soils as a ‘black box’ and do little to reveal which specific microbes or microbial communities may be responsible. This chapter examines two recent large PSF field experiments conducted in Minnesota, USA, and Jena, Germany. These experiments revealed that plants altered their soils, changing subsequent …

A Statewide Evaluation Of Fuel Treatment Effectiveness In Altering Wildfire Outcomes On Public Lands In Utah, Jamela Charmaine Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fuel treatments are land management activities that reduce living and dead flammable materials on the landscape to mitigate undesirable wildfire behavior and effects. Common treatments in the western United States include mechanical methods such as thinning and mastication, prescribed burns, and chemical methods, such as herbicide application. Treatments usually have multiple objectives, including reducing fire intensity, protecting natural and cultural resources, slowing or disrupting a potential future fire’s path, supporting ecosystem health, and reestablishing low to mid severity fire cycles in ecosystems. Although treatments can potentially modify fire behavior and ecological health, they generally cannot prevent fires from igniting, eliminate …

A Mechanistic Examination Of Interspecific Competition Between Wild And Domestic Herbivores, Courtney Check

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Large herbivores, such as mule deer and cattle have similar life histories and likely compete for resources. However, quantifying the extent to which these species compete and the specific resources they compete for has proved challenging. My research examines if cattle influence deer abundance and behavior due to competition for forage, competition for shade, and/or by affecting the predation risk of deer. Using a grid of autonomous trail cameras, I was able to determine if cattle abundance influences local deer abundance in relation to specific resources and habitat features. Using GPS data from collared deer, I was also able to …

Greater Sage-Grouse Response To Tree Canopy Removal: Habitat Vegetation Composition And Sage-Grouse Use 10–15 Years Post Treatment In The Southern Periphery Of The Species Range, Benjamen Donnelly

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pinyon juniper woodland expansion into Greater sage-grouse (Centrocercus urophasianus, hereafter ‘sage-grouse’) habitat in southern Utah continues to threaten sage-grouse survival. Habitat restoration after pinyo-juniper removal treatment is key to the continued persistence and survival of sage-grouse along the southern edge of their range. Few long-term studies are available that examine sage-grouse use of areas treated to remove pinyon-juniper forests (i.e., ‘restored habitat’). The purpose of this research was to determine if sage-grouse used ‘restored’ areas in the long-term, as a measure of the actual effectiveness of pinyon-juniper woodland control treatments. I compared vegetation composition, shrub height and shrub …

From Flames To Forage: How Wildfire Affects Elk Behavior And Abundance, Megan M. Whetzel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Rocky Mountain elk (Cervus elaphus nelsoni) is an ecologically and culturally important wildlife species in the Intermountain West, but it is facing habitat changes caused by increasing fire activity. Wildfire frequency is projected to continue to change into the future, yet increases in annual area burned and increases in area burned at high severity may actually represent opportunities for some species. Large herbivores like elk may benefit from increased access to regenerating areas where forage abundance and quality are often elevated. Therefore, effective management of wildlife populations may depend on quantifying how large ungulates, like elk, alter …

Quantifying The Impacts And Assessing The Permeability Of A Divided Four-Lane Highway On Migratory Mule Deer, Daniel P. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increased human development and expansion has led to an ever-growing transportation network, which has both direct and indirect ecological impacts to local wildlife populations. In response, wildlife crossing structures have become an increasingly fundamental component of wildlife conservation throughout the United States. The focus of this study was a 13.5 km section of US Highway 395, Mono County, California. The California Department of Transportation recently identified this section of highway, hereafter known as the Mammoth Wildlife Crossing, as the highest priority location for wildlife crossing structures along US 395 within Mono County. The goal of this study was to use …

Happy Or Sad? Quaking Aspen (Populus Tremuloides Michx.) On Cedar Mountain, Southern Utah, Jaycee Cappaert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen forests are important communities in the western United States where they provide preferential food and habitat for animals, limit wildfires from spreading, and have favorable aesthetics, among other things. Their putative decline is an issue for ecology and management. We remeasured the aspen population on Cedar Mountain, Utah, to assess changes to its condition since it was originally surveyed in 2008. We found that the area comprised of stable aspen (>80% aspen) decreased from 84.3% to 69.7%. The amount of mortality has increased slightly over the last decade, but crown dieback has stayed virtually identical. Additionally, the …

Population Physiology, Demography, And Genetics Of Side-Blotched Lizards (Uta Stansburiana) Residing In Urban And Natural Environments, Spencer B. Hudson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife populations across the globe are poised to lose their natural habitat to urbanization, yet there is limited information on how different species handle living in cities. Animals in urban environments are often susceptible to novel stressors, which can threaten their individual health and population viability. The physiological characteristics of animals, such as those related to metabolic hormones, oxidative stress, and immunity, are expected to be important for survival in this context. If so, animals persisting in urban areas may demonstrate physiological differences from their natural counterparts, perhaps due to evolutionary change. These potential outcomes have been documented in birds …

Mountain Lion (Puma Concolor) And Feral Horse (Equus Ferus) Interactions: Examining The Influence Of A Non-Native Ungulate On Predator Behavior In A Semi-Arid Environment, Peter C. Iacono

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A non-native is a species that evolved in one ecosystem and has established within another. Non-native species can thrive in new ecosystems as they can spread quickly, outcompete and replace native species, and disrupt food webs. Domestic horses were brought to North America by Europeans in 1493. They are now found in 11 states across the western United States. Feral horses can negatively impact vegetation, endangered species habitat, compete with native species, and be important prey for mountain lions under certain conditions. But do feral horses affect the food web? Feral horses are managed by large removals to reduce the …

Overcoming Barriers To Aquatic Plant Restoration: Addressing Gaps In Species Identification And Planting Techniques In The Intermountain West, Kate A. Sinnott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aquatic ecosystems provide many critical and economically valuable benefits, including drinking water, food, recreational opportunities, and water supply for irrigation and agriculture. However, the health of these systems has been severely impacted by human activities such as pollution, land conversion, and introductions of harmful species. Restoring native aquatic plants can help reverse this damage and reestablish benefits, though it is not a common practice. With an objective to increase capacity for aquatic plant restoration in the Intermountain West, I identified and addressed two major barriers: 1) a lack of confidence in aquatic species identification among wetland professionals, and 2) underdeveloped …

Impact Of Forage Conditioner Systems On The Harvesting Of Alfalfa, Derrick Hendry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study analyzed three major brands of conditioner rollers and determined how they performed in drying the forage crop alfalfa. Each type of conditioner roller would cut a wide and narrow windrow. All the windrows were tested and analyzed the same. The study was concluded once the forage was baled.

Using Genome Analysis Methods To Screen Lactococcus Starter Cultures For Bitter‐Related Genes And Establish A Differentiation Method Using Qpcr For Lactococcus Lactis And Lactococcus Cremoris Species In Cheddar Cheese, Brantzen R. Wood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumers of Cheddar cheese expect consistent flavor and texture in the cheese they eat. Cheese flavor and texture is highly influenced by the bacteria cheese makers add during cheese production. These bacteria are generally responsible for the flavors and textures consumers associate with Cheddar cheese and are referred to as starters.

Sometimes during cheese manufacture off-flavors and textures can arise that make the cheese unappealing to eat. One such flavor that is off putting is bitterness. The bitter taste in cheese arises while the cheese is aging and is largely due to the same flavor producing starters added to the …

An Evaluation Of U.S. Horseback Riding Instruction Certifications: Availability, Acquisition, Barriers, And Industry Need, Makenna L. Osborne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this mixed-methods study is to analyze the U.S. equine industry’s availability of riding instruction certification options, describe the relationship between professional certification and the self-efficacy of horseback riding instructors in the U.S., and explore the expectations that consumers have of instructors and instructor selection criteria. Two surveys were developed and sent out to instructors and consumers aligned with the research objectives designed to collect information on instructors’ self- perception of self-efficacy after certifying their perceived barriers to receiving certification, and consumers’ selection criteria for instructors. The average certified instructor was extremely satisfied with their decision to pursue …

Thermal Tolerance, Physiology, And Microhabitat Use Of Eleutherodactylus Coqui Across An Elevational Gradient In Hawai‘I, Jack Marchetti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The coqui frog (Eleutherodactylus coqui) is an invasive species in Hawai‘i, and has spread across much of the island. While elevational temperature differences are thought to restrict the coqui’s spread, it is unclear if they have resulted in changes to the coqui’s physiology and microhabitat use as it has expanded into higher elevations.

We first sought to determine if the coqui’s substrate use and baseline physiology differs between elevations. We found that frogs at high elevation were found closer to the forest floor and used different substrates than frogs from low and mid-elevations. This change in microhabitat use …

The Effects Of Recent Climate Change On Spring Phenology, With A Special Focus On Patterns Of Bee Foraging, Michael Stemkovski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The date on which plants flower and on which bees begin to pollinate varies year-to-year depending on differences in weather. This seasonal timing is known as phenology, and it is already clear that climate change has pushed the spring phenology of many species earlier by increasing temperatures. This is particularly clear in flowering plants, but studying how and why the phenology of pollinators is shifting is more difficult. Most flowering plants rely on pollinators such as bees for their reproduction, and most bees rely on flowers for their sustenance, so bee and flower phenology has to overlap for the crucial …

Habitat Selection By Desert Carnivores: How Water, Intraguild Predation, And Prey Impact Animal Space Use, Nadine A. Pershyn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Across North America large carnivores have lost nearly half of their historic range, creating openings for smaller (< 15 kg) carnivores to take over their ecological roles. Coyotes (Canis latrans) have seen a significant range expansion, including into arid deserts. It was believed that the addition of artificial water sources by humans allowed coyotes to expand into desert ecosystems where they were previously unable to survive. The kit fox (Vulpes macrotis) is a small, desert-adapted carnivore with declining populations that faces threats from coyotes of intraguild predation. This is when carnivores compete over the same prey, and the larger carnivore (intraguild predator) kills the smaller carnivore (intraguild …

Fish Community Impacts And Conservation Implications Of A Novel Barrier On The San Juan River, Utah, Zachary T. Ahrens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stream fragmentation and non-native species introductions are among a suite of anthropogenic disturbances shaping the structure and function of freshwater ecosystems. The impacts of such alterations contribute to the global decline of stream fish biodiversity and may be synergistic in their effects. For example, the Colorado River basin’s unique native fish assemblage is imperiled not only by numerous dams and diversions, but also by threats of predation and competition for limited resources from non-native fish species. On the San Juan River, Utah, a recently formed fish barrier prevents upstream movement of native and non-native fish. The goal of this project …

Local And Regional Landscape Characteristics Driving Habitat Selection By Greater Sage-Grouse Along A Fragmented Range Margin, Aidan T. Beers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In response to ongoing landscape change, wildlife species are likely to respond in varied ways. By studying habitat specialists, we are able to better understand the most likely ways in which the denizens of threatened ecosystems will react to those changes. Among the most threatened ecosystem types in North America are sagebrush ecosystems of the Intermountain West, where one of its most well-known residents, greater sage grouse (hereafter, “sage-grouse), have lost more than 50% of their habitat due to fire, invasive species, climate change, encroachment by coniferous forests and avian predators using it, and human-caused landscape conversion. Sage-grouse rely on …