Digital Commons Network^™

A Provable Semi-Infinite Programming Approach For Solving Dynamic Nash Games, Tyler C. Gardner

All Graduate Theses and Dissertations, Fall 2023 to Present

Many engineering problems must account for the non-cooperative decisions and actions of multiple players. These problems can be modeled within a game-theoretic framework. The approach herein is to model problems as Nash games, convert them to semi-infinite programs, and leverage provable semi-infinite algorithms to solve the original problem. A particular algorithm that leverages off-the-shelf solvers is used to solve four low-dimensional benchmark problems successfully. Two types of linear quadratic dynamic games are then investigated: ones where each player’s problem is convex and ones where at least one player’s problem is nonconvex. Within each type, variations based on information structure, communication …

Optimization Of The Root Zone In Controlled Environment Agriculture, Brendan Fatzinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Controlled environment agriculture (CEA) helps grow plants in spaces where resources like water and nutrients are limited, such as deserts or spacecraft. Effective management of water in the root zone, the area where plant roots grow, is vital to keeping plants healthy, especially in closed-loop systems where water cannot be wasted, as will be necessary for long-duration space missions.

An improved automated watering system designed for use in space-like environments was developed over several trials. Early designs using suction to draw water through tubes faced problems with uneven watering and roots blocking the tubes. Switching to a system that pushed …

An Embodied Social Demography For Trans And Nonbinary Workers, Jesse Ezra Shircliff

All Graduate Theses and Dissertations, Fall 2023 to Present

Recently, the separation of “sex” and “gender” has seen intense debate in public discourse, stemming from skepticism about the social sciences and the measurement and study of gender specifically. Meanwhile, the United States population is becoming more gender diverse, with roughly 1 in 200 people now identifying as trans gender or gender nonbinary (that is, as a gender that is different from that person’s sex assigned-at-birth or outside of the sex-gender binary). This growing population experiences numerous disadvantages across social life, including obstacles in one particularly important aspect of the American Dream: the right to have and hold a job. …

Adapting To Change In Amenity-Oriented Communities: Innovative Strategies For Shifting Social And Environmental Needs, Emma L. R. Epperson

All Graduate Theses and Dissertations, Fall 2023 to Present

Amenity-oriented communities are places with significant and desirable natural amenities that are highly visited and plentiful within the Intermountain West. These high rates of visitation create complex challenges such as congestion in recreation spaces and in towns and increase costs of living. These communities are typically rural and often do not have the resources, funding, or infrastructure to combat these challenges. Although tourists provide financial stability and other amenities to these towns, local wellbeing is highly impacted. Outdoor recreation and the nature connections derived from outdoor experiences are major contributors to wellbeing in amenity communities. This research investigates the changes …

Optimizing Delphinium And Larkspur Through Timing And Protective Cultivation Methods For Cut Flower Production, Nicholas Kirwan Volesky

All Graduate Theses and Dissertations, Fall 2023 to Present

Cut flowers have become an increasingly important specialty crop for small farms nationwide, and particularly in Utah, where decreasing agricultural land has heightened the need for profitable cropping options. However, production is challenged by Utah’s high-elevation climate, which presents unique constraints not addressed by current recommendations. Cool-season crops, like delphinium (Delphinium spp.) and larkspur (Consolida ajacis L.), are underproduced yet highly marketable, generating strong interest among growers throughout the state. Developing region-specific production guidelines is essential to help optimize yields, extend harvest windows, and meet local demand. This research evaluated spring planting dates in high tunnel and field …

Cutting Propagation And Out-Planting Of White-Margined Beardtongue (Penstemon Albomarginatus M.E. Jones), A Vulnerable Herbaceous Perennial Of The Mojave Desert), Alexander Stosich

All Graduate Theses and Dissertations, Fall 2023 to Present

Plant biodiversity is crucial for the proper functioning of ecosystems, with many species needed to maintain the variety of functions provided, especially with increasing environmental change. However, plant biodiversity is threatened in many different ecosystems, primarily through habitat loss. Species can be conserved by protecting their original habitat and mitigating for threats such as invasive species or altered disturbance regimes (plant conservation); however, with declining population numbers and continued habitat loss and/or disturbance, it may be necessary to actively move plants (plant restoration). Plant restoration is dependent on developing the capacity to a) reliably propagate plants in a nursery and …

Evaluating Cyanotoxins In Surface Water And Aerosols Near Utah Lake, Dylan R. Mcpeake

All Graduate Theses and Dissertations, Fall 2023 to Present

Utah Lake is a freshwater lake in Utah County near Provo, Utah. It is the third- largest lake in Utah and is important for recreation and local businesses. However, from June to October, the lake often has cyanobacteria harmful algal blooms (cHABs), which contain a toxin called cyanotoxin. These toxins can be dangerous to people who come into contact with the water. Government agencies regularly check for cHABs and warn people when the water is unsafe for activities like swimming. Collecting water samples to test for cHABs can be risky because it can possibly result in direct contact with the …

From Rifles To Running Shoes: How Outdoor Recreation Trends Are Reshaping Conservation Efforts, Lane James Arthur

All Graduate Theses and Dissertations, Fall 2023 to Present

Parks and protected areas (PPAs) serve a dual purpose: they conserve wildlife and natural habitats while providing spaces for people to enjoy outdoor recreation. However, balancing conservation with recreation can be challenging, especially as outdoor activities continue to grow and evolve. In Utah, Wildlife Management Areas (WMAs) are set aside to protect important wildlife habitats and provide opportunities for hunting and fishing. Recently, these areas have seen an increase in activities such as mountain biking, trail running, and dog walking, some of which take place in areas which prohibit recreational activity in effort to protect wildlife. These shifts in recreation …

Effects Of Elevation, Fire Age, Burn Severity, And Pre-Fire Vegetation On Post-Fire Sagebrush Songbird Communities, William D. Harrod

All Graduate Theses and Dissertations, Fall 2023 to Present

The Sagebrush Biome of western North America has been threatened by a combination of interconnected threats. In the Great and Columbian Basins, a large portion of sagebrush loss has been due to an increase in higher-severity wildfires, caused by invasive annual grasses. As sagebrush declines, numerous wildlife species that rely on the biome have experienced similar trends. Sagebrush-adapted songbirds such as sage thrasher, Brewer's sparrow, and sagebrush sparrow as well as steppe-songbirds, have all experienced population declines. Currently, limited information exists as to how fire severity or recovery affect these songbirds or what resource managers can do to improve their …

Evaluating Maternal Polar Bear Denning Habitat Along The Arctic Coastal Plain And Assessing The Potential For Noise Disturbance In Polar Bear Dens, Ethan Ducharme

All Graduate Theses and Dissertations, Fall 2023 to Present

Polar bears (Ursus Maritimus) in northern Alaska are increasingly choosing land instead of sea ice to build their maternity dens. As sea ice continues to decline due to climate change, this shift makes it more important than ever to identify and protect the areas where polar bears dig dens to give birth and raise their cubs. In the first part of my research, I used new satellite-based elevation data to map potential polar bear denning habitat across a large section of Alaska’s Arctic Coastal Plain. This technology allowed me to identify the types of sloped terrain where drifting …

Habitat Selection Analysis Of Mule Deer To Determine Efficacy Of The Coyote Bounty Program In Utah, Xaela M. Walden

All Graduate Theses and Dissertations, Fall 2023 to Present

Mule deer populations have been declining over the past couple of decades in many parts of the western United States. Often times, predators are blamed for the decreases in deer populations. Because of this, wildlife managers implement programs focused on reducing the number of predators on the landscape in an attempt to increase deer populations. However, predator removal programs have had mixed results, thus further investigation is needed to determine if coyote removals by the public through a bounty program have a positive effect on mule deer populations. My study investigated whether coyote removals through the bounty program in Utah …

Enabling Sustainability Transitions For Great Salt Lake: Framing Of Public Opinion, Boundary Work, And Policy, Anna Mcentire

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation explores how people think about, talk about, and take action to save Great Salt Lake, which reached historic low levels in 2021. Using surveys, public records, and legislative documents primarily from 2022 to 2024, the research examines public opinions, collaborative efforts, and policy changes related to the lake. The first chapter looks at what people value about the lake and what actions they want to see taken. It finds that people are very concerned and want significant efforts to stop the lake's decline. The second chapter investigates how different groups work together publicly to negotiate new understandings, create …

Evaluating The Effects Of Two Key Temporal Intervals During Pavlovian Training On Conditioned Reinforcement, Gabrielle M. Sutton

All Graduate Theses and Dissertations, Fall 2023 to Present

Reinforcers are anything that increases or maintains the frequency of a behavior that precedes their occurrence. Reinforcers can be separated into two types, primary and secondary. Primary reinforcers are biologically relevant stimuli like food, water, or drugs that can influence behavior without any prior training. Secondary reinforcers are those that impact behavior through their trained relationship with a primary reinforcer, like money and tokens. For this reason, they are also known as conditioned reinforcers. Conditioned reinforcers are used in therapies and training designed to increase desirable behaviors, but they are also involved in the development and maintenance of maladaptive behaviors …

Early And Late Season Weed Control In Dormant Alfalfa, Mckenna Saige Barney

All Graduate Theses and Dissertations, Fall 2023 to Present

Hexazinone + diuron is an herbicide mix commonly used to control weeds in established alfalfa in the late fall or early spring when alfalfa is dormant. If applied outside full dormancy, this mix can cause significant crop injury. The Intermountain West’s cold weather leaves a narrow time frame for applicators to apply herbicide. To help extend the application period to when alfalfa has not yet entered complete dormancy, the burndown herbicide paraquat can be added to the tank mix. Paraquat burns back existing plant matter to prevent hexazinone + diuron from spreading throughout the plant and causing long-term crop injury. …

Assessing Long-Term Changes In Aspen Forest Cover In Northern Yellowstone National Park Before And After Carnivore Recovery, Nicholas J. Bergeron

All Graduate Theses and Dissertations, Fall 2023 to Present

The recovery of large carnivores (wolves, bears, cougars) in Yellowstone National Park and the subsequent decline of the area's elk herd have raised key questions about ecosystem restoration—particularly for species such as aspen, which are heavily browsed by elk. Following wolf reintroduction in the mid-1990s, scientists began tracking changes in browsing intensity and height of young aspen within sampling plots, assuming reduced browsing and taller stems were signs of population recovery. However, no studies have measured whether the total area covered by aspen stands actually increased, as would be expected with broader recovery. Moreover, the potential influence of climate change …

Aquatic Habitat Representation For Robust Water Resources Management And Fish Conservation Decision-Making, Gregory C. Goodrum

All Graduate Theses and Dissertations, Fall 2023 to Present

We rely on rivers to provide water supply, flood control, and hydroelectricity for people and to sustain aquatic ecosystems. The development of dams and reservoirs to provide water for people did not consider environmental impacts to rivers, leading to widespread decline of freshwater species and habitat. Improving environmental outcomes of water management is needed to protect and restore aquatic ecosystems. However, rivers are complex and variable, making them difficult to represent as objectives for water management. This dissertation explores approaches to improve aquatic habitat representation and environmental objectives for water resources management and river conservation and restoration.

Chapter 2 uses …

Precision Agriculture Applications In Tart Cherries: Yield Mapping Technologies And Remote Sensing For Water Stress Estimation, Anderson Luiz Dos Santos Safre

All Graduate Theses and Dissertations, Fall 2023 to Present

Tart cherry is an important specialty crop in the United States, particularly in Utah where the area dedicated to tart cherry cultivation is larger than any other fruit grown in the state. However, growers face increasing challenges due to rising land prices, limited water availability, and extreme weather events. These factors make it essential to adopt new technologies that improve efficiency and sustainability. Precision agriculture, which uses data-driven tools to manage crops more effectively, can help address these challenges. However, most tart cherry orchards still rely on traditional practices due to a lack of specialized technologies for this crop. This …

Linking Variation In Mule Deer Nutritional Condition And Age To Population Performance In A Temperate Environment, Kent R. Hersey

All Graduate Theses and Dissertations, Fall 2023 to Present

The amount of body fat animals have as they enter and exit winter can have major impacts on how well they survive and reproduce. Mule deer are widely distributed herbivores whose survival and reproduction are strongly tied to weather patterns and the quality of vegetation they consume, which in turn impacts nutritional condition. The objective of this study was to identify and quantify the factors (animal specific, climatic, or habitat) influencing mule deer body fat during both summer and winter in Utah and examine how nutritional condition influences survival. We found December body fat was most affected by December lactation …

Ecology And Management Of Forest Grouse: Breeding Acoustic Monitoring, Spatial Behavior, And Harvest, Logan Clark

All Graduate Theses and Dissertations, Fall 2023 to Present

Forest grouse are difficult to study and manage in the Intermountain West because they live in remote, rugged areas and do not gather at predictable display sites like other grouse species. From 2023 to 2025, I studied two species, dusky grouse (Dendragapus obscurus) and ruffed grouse (Bonasa umbellus), to test new survey tools, track their seasonal movements, and evaluate hunting impacts.

First, I tested whether small audio recording devices placed in the forest could minimize labor needed for spring breeding surveys. To do this, I conducted traditional surveys with human observers at the same time and …

Morphological Correlates Of Limaxivory In Contia (Serpentes: Dipsadinae) Compared To Related Taxa Carphophis And Diadophis, Lauren A. Houstoun

All Graduate Theses and Dissertations, Fall 2023 to Present

Differences in the skull and musculature of snakes can often be linked to their diet. Snakes that eat snails and slugs have evolved independently at least four times. Several skull features of the skull have already been reported in snakes that eat snails, specifically those in the genus Pareas and some Dipsadini. Among those features are a shorter, more compressed snout and, in some species, asymmetry of the lower jaw. However, little attention has been paid to snakes that specialize only on slugs (limaxivores). Unlike the snail-eating members of the Pareidae and Dipsadini, limaxivores lack the morphological traits associated with …

Exploring Biotic And Abiotic Drivers Of Ecosystem Properties: The Influence Of Waterbirds And Photodegradation On Wetland Ecosystems, Lindsay Miller

All Graduate Theses and Dissertations, Fall 2023 to Present

Wetlands provide a wide range of valuable ecosystem services: these are benefits from the environment that support human well-being, such as water filtration, fish and bird habitat, and shoreline protection. Despite their importance, wetlands are among the most threatened ecosystems, facing increasing pressure from natural and human activities. To better predict the future of wetlands and guide effective management and restoration practices, we need to understand the various forces shaping their ecological properties. In this thesis, we examined the influence of two forces: waterbirds and photodegradation (the process by which sunlight breaks down plant material). To explore each of these …

Exploring The Long-Term Impact Of Dating And Family Violence On American Indian Youth And Adults: The Role Of Belongingness In Moderating Negative Effects, Racheal M. Killgore

All Graduate Theses and Dissertations, Fall 2023 to Present

Exposure to violence during childhood and adolescence is an important issue, particularly among Native Americans, who experience violence at higher rates compared to other racial/ethnic groups. This early exposure to violence can significantly affect future physical and mental health outcomes—including depression, substance abuse, suicide attempts, obesity, and premature death—while also shaping subsequent relationships in adulthood. Though widely studied in the general population, research focused on American Indians is lacking, with cultural contexts and factors uniquely shaping the experiences of those affected. In AI/AN communities, belongingness is important for well-being and, as such, is a relevant cultural factor that calls for …

Setting Salinity Water-Quality Standards Protective Of Aquatic Life: Insights From Analyses Of The Effects Of Salinity On Stream Insects, Katlyn M. Gardner

All Graduate Theses and Dissertations, Fall 2023 to Present

Freshwater ecosystems are becoming saltier due to human activities like agriculture, urbanization, and resource extraction. This change in salinity is important because we know very little of how stream salinity affects aquatic insects at natural concentrations, much less at elevated concentrations. Increases in salinity may harm aquatic macroinvertebrates, which play important roles in stream food webs and are widely used as indicators of ecosystem health. Understanding how salinity affects aquatic insect growth, survival, and distribution is critical for developing effective criteria protective of aquatic life, but existing methods often rely on field surveys where multiple environmental factors covary, making it …

Water Conservation Strategies For Growing Ornamental Plants In Utah Landscapes, Jenny L. Koller

All Graduate Theses and Dissertations, Fall 2023 to Present

When early pioneers settled in Utah, they faced challenges living in a dry region with limited water. They built dams, canals, and irrigation systems by working together as a community to manage their water needs. However, adoption of European landscaping methods, farming and rapidly growing population increased water need while climate change and frequent drought reduced water supply.

Today, Utah is one of the driest states and uses more water per person than most other states in the nation. If things don't change, the state could run out of water by 2060. To address Utah's growing water challenges, this research …

Evaluation Of Novel Biomarkers As Predictive Measures Of Mastitis – Establishing A Relationship With Health Status, Lamb Performance, And Determination Of Prevalence Of Mastitis In Ewes Under Intensive Management, Courtney Berghoff

All Graduate Theses and Dissertations, Fall 2023 to Present

Inflammation of the mammary gland, also known as mastitis, is a prevalent and financially impactful disease in sheep production. The objectives of this survey were to 1) evaluate current testing methods: somatic cell count (SCC), California Mastitis Test (CMT), and bacterial culture, as well as novel biomarkers: lamb performance, milk composition, and udder conformation, for their impact on ewes categorized as clinically healthy or unhealthy under intensive management systems at 15 days in milk (DIM) and 30 DIM, and 2) identify biological markers that are correlated with clinical and subclinical mastitis. Milk, blood, and fecal samples, a visual and physical …

An Exploratory Study Of The Vertical Snarc Effect In Mayan Numerals: Effects Of Language Transparency And Reading Direction, Emmett A. Speed

All Graduate Theses and Dissertations, Fall 2023 to Present

The Mayan numerical system, used by the ancient Maya people, is very different from the Western Arabic numerical system. Instead of being based on 10, it's based on 20, and it uses dots and bars instead of the numbers 0 through 9. This study explored how people learn and understand Mayan numbers.

Participants took a 2.5-hour online course to learn Mayan numerals and number words. They were tested to see how quickly and accurately they could recognize and compare Mayan numerals. The results showed that people can learn the Mayan number system and use it automatically.

The study also looked …

Impacts Of 4r Nitrogen Management And Water Optimization On Soil Health, Kamaldeep Kamaldeep

All Graduate Theses and Dissertations, Fall 2023 to Present

Farmers in Utah and Idaho are facing growing challenges due to high fertilizer costs, limited irrigation water, and pressure to improve long-term soil health. To better understand current practices and grower attitudes, a survey was conducted in 2020 targeting 5,000 producers of small grains, corn, and potatoes. Although the response rate was low, 146 growers representing over 25,000 hectares of cropland participated. Survey results showed that most growers are open to improving nitrogen and irrigation practices and care about their soil health, even if not all are fully using 4R or precision agriculture methods.

This thesis includes two field studies …

Unveiling Insights From Complexity: Advanced Computational Techniques For High-Dimensional Medical Data, Devin P. Eddington

All Graduate Theses and Dissertations, Fall 2023 to Present

Healthcare generates vast amounts of data daily, from genetic profiles to hospital records, but much of it remains untapped due to its complexity. This dissertation develops new computational tools to unlock this data’s potential, aiming to improve patient care and medical research. Five projects tackle different challenges: Project 1 creates Deep MAGIC, a method to fill in missing genetic and image data accurately, vital for understanding diseases like cancer. Project 2 analyzes how the COVID-19 pandemic disrupted surgeries, finding a 27% drop and temporary complication rises in 2020, guiding future crisis planning. Projects 3 and 4 study kidney disease trials, …

Factors Influencing Cognitive Load: Exploring Affective Elements, Motivational Constructs, And Regulatory Strategies In Learning, Rebecca B. Brockbank

All Graduate Theses and Dissertations, Fall 2023 to Present

There are three separate research papers within this dissertation, each looking at specific elements of learning. The process of learning is a complex phenomenon that includes not just cognitive aspects, but also emotional and motivational aspects. During learning there is an input of information into our cognitive system (i.e., minds). When too much information is given or the information is not presented effectively, this can overload our cognitive system and negatively impact our learning. Understanding how to learn within the parameters of our cognitive system is important. However, learning is more complex than just the simple input and output of …

Watermelon Production In Utah: Exploring Biostimulants To Reduce Water And Fertilizer Use, Evan A. Christensen

All Graduate Theses and Dissertations, Fall 2023 to Present

The impacts of climate change and drought threaten water supplies that are important for watermelon production. Additionally, rising fertilizer costs and off-site effects from improper fertilizer applications cause concerns for the sustainability of watermelon production. Biostimulant products have shown promise in helping plants maintain production under reduced irrigation conditions and may offset fertilizer addition. Biostimulants are any microorganism or substance that is applied to a plant with the goal to increase nutrition efficiency, crop quality traits, or tolerance to environmental stresses. Most of the production in the U.S. uses seedless watermelon which are typically grown in greenhouses and transplanted due …