Life Sciences Commons^™

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 …

Evapotranspiration And Energy Balance Of Irrigated Urban Turfgrass, Matthew D. Miksch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water usage for irrigation is a big consumer of water resources in urban areas in Utah and other parts of the Intermountain Region of the Western United States. As populations continue to increase in these states, it is important to understand how much water is being used by urban landscapes in order to plan and manage future water resources. Evapotranspiration (ET), or the amount of water leaving a surface over a certain timeframe due to both transpiration from plants and evaporation from the soil, is a key variable in understanding how much water urban landscapes are really using to grow …

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 …

Evaluating Methods For Pathogen Spillover Detection And Forecasting In Desert Bighorn Sheep (Ovis Canadensis Nelsoni), Grete E. Wilson-Henjum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Managers mitigate the effects of disease on wildlife populations by detecting outbreaks and predicting disease transmission. Bighorn sheep (Ovis canadensis) populations face threat from the introduced pathogen Mycoplasma ovipneumoniae (M. ovipneumoniae). In the eastern Mojave Desert, managers detect pathogen outbreaks in desert bighorn (O. c. nelsoni) through aerial population surveys, which produce irregular and coarse population information. Furthermore, managers model the risk of M. ovipneumoniae transmission amongst desert bighorn populations, however these models assume that desert bighorn space use is unchanging across years. Here, I evaluate methods used by managers to detect disease outbreaks …

Social Factors Driving Grouping Dynamics In Bighorn Sheep Ewe, Toni Proescholdt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding and predicting movement is critical for conservation planning and disease risk mitigation, and important environmental drivers of animal movement have received extensive attention in the ecological literature. Social factors surrounding group fission and fusion events also directly affect movement. However, these events are infrequently measured in the wild and rarely linked to underlying mechanisms such as relatedness, agreement in reproductive status, or shared life stage. While some social factors cannot be directly observed in the field, individual animals congregating in groups and moving about a landscape can. In animal societies, groups may merge together in a fusion event, and …

Assessing Stream Ecosystem Structure And Function In An Urban Canal And Logan River In Logan, Utah, Ellie Smith-Eskridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans have constructed canals to support agriculture, to mitigate flooding, and to discharge stormwater, especially in the Intermountain West. These canals are common in Cache Valley, where they receive flows from the Logan River during summer months. However, the ecological structure (e.g., water quality, freshwater invertebrates) and function (e.g., leaf decomposition) of these canals remains largely unknown. Studying ecosystem structure and function of these urban waterways is important because it can inform us of the health of these waterways.

My research had three objectives. First, I compared water chemistry, invertebrate assemblages, and leaf decomposition in an urban canal and the …

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 …

Effect Of Increasing Levels Of Gossypol And Fatty Acids Coming From Whole Cottonseed On Rumen Fermentation, Nutrient Digestibility And Microbial Community Composition In Continuous Culture Fermenters, Camila Castro Veloz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In this study we determined the impact of increasing dietary whole cottonseed (WCS) on rumen fermentation, nutrient digestibility, and microbial community composition. This study contributes novel information to the dairy community deepening the understanding of how including different levels of WCS can affect the rumen environment. This research was conducted in continuous culture fermenters. Treatments included a control diet without WCS, or the control diet plus 5, 10, or 15% (dry matter) WCS. The control diet was a 50:50 orchardgrass hay:concentrate mixture fed twice daily. In the second experiment, soybean meal and cottonseed meal (CSM) were included, and rations were …

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 …

Student Perceptions Of Male And Female Instructors In A Post-Secondary Welding Course, S. Kjersti R. Decker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural mechanics and welding have traditionally been perceived to be careers reserved for males, yet more females have entered professions using welding such as agricultural education. This research was developed because of the lack of gender research in welding. The purpose of this study was to examine students’ perceptions of learning from a male instructor versus a female instructor in a post-secondary welding course. We examined associations and differences between students’ preference of a male and a female welding instructor as well as individual self-efficacy and perceptions towards using welding technology. The population for this study was undergraduate students and …

Regeneration Of Quaking Aspen And Understory Vegetation Change After Fire Risk Reduction Treatment, Allison M. Trudgeon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides Michx.) is a keystone species that, when coexisting with conifers (i.e., seral aspen), often undergoes stand-replacing disturbances to sustain long term vigor. Historically, mixed-to-high severity fire reduced fuels and regenerated aspen, but such disturbances have become less common in recent decades. This has often led to high fuel loading, and many seral aspen stands are at now risk of an unpredictable, high-severity fire, posing a threat to development in the wildland-urban-interface. The lack of a commercial market for aspen, and the risk of conducting prescribed fire, means there are few alternate management options. This has …

Practical Improvements For Pivot And Surface Irrigation, Jonathan A. Holt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Irrigation is critical to meeting global food and fiber demands. Optimizing agricultural irrigation may help sustain production levels, while reducing its demand for water. This research evaluated precision sprinklers and drip irrigation for pivots, five pivot track mitigation tools, three scientific irrigation scheduling (SIS) methods, sensors for surface irrigation cutoff, and automating surface systems to implement surge irrigation. With pivots and surface irrigation being the most common methods for irrigation in the West, small improvements from these tools could result in significant water savings.

Low energy precision application (LEPA) sprinklers and mobile drip irrigation (MDI) were tested on two pivots. …

Evaluating Quaking Aspen's Influence On Fire Behavior, Kristin A. Nesbit

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In western North America, quaking aspen (Populus tremuloides Michx.) forests have long been described as low flammability, “fireproof” forest types that are less likely to burn or burn less intensely than coniferous forests. While this assumption has been based on limited scientific research and is largely anecdotal, there is growing interest in the western U.S. to promote aspen near human developments to reduce fire risk. I investigated the available evidence for aspen forests reducing fire occurrence, behavior, and severity, and assessed possible factors that affect flammability in aspen forests to better understand when and where aspen burn, and when …

A Fine-Scale Understanding Of Sagebrush Islands To Improve Restoration Outcomes In The Intermountain West, Sofia Koutzoukis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, rapid expansion of non-native grasses, primarily cheatgrass, has created a repeating cycle where cheatgrass easily ignites and after a fire, more cheatgrass establishes in the burned area, leading to more fire, and more cheatgrass. The primary method to prevent further fires is to plant grass and shrub seeds after a fire because they can deter cheatgrass from establishing and reduce the chance of fire. However, this approach does not always work. There is a need and interest in alternative ways to establish native grasses and forbs.

Sagebrush, the dominant shrub of lower-elevation regions of the Intermountain …

Consequences Of Host Life Cycles For Symbiont Genome Evolution, Ashley Elizabeth Dederich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aphids are small insects that feed exclusively on plant sap, a notoriously low source of nutrients due to the high sugar content and low amino acid content. To make up for these deficiencies in nutrition, aphids harbor Buchnera aphidicola, a bacterial endosymbiont that resides in a specialized organ called the bacteriome. B. aphidicola provides essential amino acids and vitamins for the aphid in exchange for a safe place to live. Over the course of the symbiosis (established 160 million years ago), B. aphidicola has lost much of its genome, including essential genes for cell envelope synthesis, DNA replication and …

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 …

Use Of Protective Lactic Acid Bacteria Adjunct Cultures To Decrease The Incidence Of Gas Defects In Cheddar Cheese, Rhees T. Crompton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gas production in cheese making is becoming increasingly prevalent in the dairy industry. This gas is produced by microbes that are naturally found in the cheese, and when they metabolize sugar or other sources of energy, they can produce gas. This gas causes slits and cracks in the cheese, which causes the cheese to be worth less and causes issues during slicing and shredding. There are many microbes that cause unwanted gas in cheese, this research focuses on four know gas producers and five other protective microbes that use the same energy sources or have the ability to inhibit the …

Bugs, Bullets And Birds: Factors Affecting The Health And Survival Of Ferruginous Hawk Nestlings In The Intermountain West, Ellis A. Juhlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ferruginous Hawks are a bird of prey species that nest in sagebrush steppe and grassland habitat. These birds are threatened by habitat loss and fragmentation from urbanization, rural development, oil and natural gas extraction, habitat treatment projects, and wildfires, and experiencing widespread population declines across their breeding range. Because of this, Ferruginous Hawks (FEHAs) have been deemed a Species of Greatest Conservation Need by state management agencies in Utah, Idaho, Wyoming and Nevada. The health and survival of Ferruginous Hawk (FEHA) nestlings is crucial to long-term population viability. Understanding the threats these birds are facing as nestlings can provide valuable …

Dust Deposition Changes Production, Chlorophyll-A And Community Composition In Mountain Lakes, Jiahao Wen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Increasing quantities of dust emitted from semi-arid soils, agricultural soils, and urban regions are blown to remote mountain lakes in the American West. Remote mountain lakes lacking local nutrient inputs and presenting simple food webs that are easily affected by climate changes. Dust can carry nutrients (e.g., nitrogen and phosphorus) to mountain lakes and potentially enhance algae growth and change algal communities. However, experimental tests of this hypothesis are lacking. Using in situ experiments, we investigated the effects of dust enrichment on the production, biomass, and primary algal species in three mountain lakes in the American West. We found that …

Rainfall Increases Alpha And Has No Effect On The Beta Diversity Of Animal-Dispersed Shrubs In Panama, Rosemary Hopson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate patterns affect where plants can grow and survive. In tropical areas, the main form of precipitation is rain, and rainfall has been demonstrated to influence tree species distributions. For this thesis, I examined the relationship between rainfall and the diversity of animal-dispersed tropical shrubs. To do this, I used data on shrub diversity collected in the summer of 2017. Plots were established across the Isthmus of Panama, from the drier Pacific side to the wetter Atlantic side, to survey animal-dispersed shrubs. I analyzed three metrics of diversity that weigh rare and common species differently. The first weighs rare species …

Quantifying Floral Resource Availability Using Unmanned Aerial Systems And Machine Learning Classifications To Predict Bee Community Structure, Jesse Anjin Tabor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bees are important for agricultural and non-agricultural ecosystems because they pollinate both wild plants and commercial crops. Flowers provide pollen and nectar resources that bees use to survive and reproduce. Measuring the relationship between the floral community and bee community may help apiarists and land managers to make informed decisions in managing wild and domesticated bee species. Manual methods to describe and count flowering vegetation is costly in time and personnel. Unmanned aerial vehicle (UAV) technology may be an efficient way to describe and count flowering vegetation on a large scale. UAVs with classification analysis and ground transect surveys were …

Functional Characterization Of The Newly Discovered Type V Crispr-Cas Protein Cas12a2, Dylan J. Keiser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Similarly to people, bacteria are under the treat of infection by viruses. To circumvent these threats, bacteria evolve complex immune systems. Our understanding of some of these immune systems has led to many advancements in the field of Biotechnology including tools that made expressing proteins for study in a lab easier, tools that revolutionized the feasibility of gene editing, and tools that could change the way we think about viral diagnostics and cancer therapeutics. A certain type of immune system that bacteria use to fight virus is called a CRISPR system. Presented here is work to understand the function of …

Assessing Post-Fire Revegetation Efforts In Box Elder County, Utah, Using The Rangeland Analysis Platform, Rayce Bryan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

After fires occur in western rangelands, land management agencies commonly perform vegetation treatments and reseeding projects. The West Box Elder Coordinated Resource Management Group expressed concern regarding the difficult process of determining outcomes from the many post-fire revegetation projects undertaken on rangeland of Box Elder County, Utah. This research attempted to compile and clarify the fire and treatment history of the county and produce an assessment of the outcomes from each unique post-fire treatment in West Box Elder County. Also produced was a database of post-fire revegetation outcomes in published literature.

Unique treatment polygons were identified and then subset according …

Pronghorn Space-Use Ecology In Utah, Veronica A. Winter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pronghorn are viewed as a quintessential part of the landscape in the American West. Found only in western North America, pronghorn is a unique species, having historic ranges within prairie, shrubland-steppe, and desert habitat across the continental west. Even though they have been present on this landscape since the last ice age, little is known of pronghorn ecology. There has been growing concern over the impact anthropogenic features, such as development, agriculture, and roads are having on migration, seasonal range conditions, and overall population dynamics. The aim of this thesis is to investigate factors that may be important for pronghorn …

Seed Ecology And Regeneration Processes To Inform Seed-Based Wetland Restoration, Emily E. Tarsa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands provide immense value to wildlife and humans but have been degrading rapidly around the world. One major challenge is the loss of native plant species in wetlands, which limits the ability of wetlands to function as they should. Restoring wetlands requires a combination of removing the cause of degradation (such as invasive plant species) and, in many cases, actively returning native plants to the site especially via seeding. Further, early plant life stages are the most vulnerable for plants and is often the time in which sown species die and fail to establish. Thus, understanding how and why seeds …

Nest‐Site Selection, Success, And Response To Predators By Cinnamon Teal And Other Ground‐Nesting Ducks In The Wetlands Of Great Salt Lake, Utah, Mark E. Bell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The wetlands of Great Salt Lake once supported hundreds of thousands of nesting ducks each year. In recent years, the number of nesting ducks in the same area was a fraction of those historic numbers. While many species of ducks do not rely on these wetlands for primary nesting habitat, cinnamon teal (Spatula cyanoptera) do. Great Salt Lake and its associated wetlands are in the heart of the cinnamon teal breeding range, and once supported half of the continental population.

These wetlands are unique from other wetlands where waterfowl nest because they are artificially created using dams to hold …

Insecticide Susceptibility And Resistance Detection In Phlebotomus Argentipes Sandflies (Diptera: Psychodidae: Phlebotominae), Shawna M. Hennings

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Leishmaniasis is an understudied disease found predominantly in high heat and humidity areas. The disease is transmitted by sandflies which are blood-feeding, biting insects. There is currently no known vaccine for any form of leishmaniasis and treatment imposes a significant economic impact on already poor and marginalized populations, as well as severe, lingering side effects for afflicted individuals. Annually, there are millions of people around the world afflicted with a form of Leishmaniasis that is transmitted by species of sandflies. The primary sandfly population control method for over half a century has been indoor residual spraying using insecticides. The selective …

Immunological Tradeoffs And The Impacts Of Urbanization On The Reproductive Ecology And Physiology Of The Side-Blotched Lizard (Uta Stansburiana), Emily E. Virgin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investing resources into reproduction can limit energy available to other competing demands, such as fighting off an infection; yet, both processes are necessary for organisms to survive and pass on their genes to the next generation. These strategies often follow patterns associated with lifespan, such that shorter-lived animals are more likely to invest more resources into reproduction over survival, and vice versa in long-lived animals. However, environmental change caused by urbanization can disrupt these relationships, and the within- and transgenerational costs of urbanization on females and offspring are unknown. I address these uncertainties in three research chapters to better understand …

Approaches To Supplementing Silicon In Soilless Media And The Value Of Silicon In The Mitigation Of Drought Stress, Mackenzie Grace Dey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Silicon (Si) is not considered an essential element for plants to complete their lifecycle, but is known to be beneficial for plants under environmental stress such as drought. Unlike natural soils, Si is minimally bioavailable in soilless media. With indoor agriculture and greenhouse production increasing, the benefits of Si have been seen and Si should be supplemented. This work aimed to characterize and quantify the dissolution of Si from media substrates and additives to achieve a steady-state release of Si in soilless media. Typical media components such as coconut coir, peat moss, perlite, rock wool, sand, and vermiculite minimally released …

Evaluating Strategies For Anemone And Ranunculus Cut Flower Production In The Us Intermountain West, Shannon Rauter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

National growth in small-scale, specialty cut flower farms is reflected in Utah, where 145 members have joined the Utah Cut Flower Farm Association since its 2019 founding. Cool season cut flower production is limited in Utah and the Intermountain West by a narrow harvest window and elevated soil salinity. The objective of this research was to optimize production systems for anemone (Anemone coronaria L.) and ranunculus (Ranunculus asiaticus L.) in the Intermountain West by evaluating season advancement methods within a high tunnel and field production system, as well as the salinity sensitivity of each species. Fall planting dates, …