Digital Commons Network^™

Population Analysis Of Cyanobacteria In Rotating Algal Biofilm Reactors, Eric H. Matthews

All Graduate Theses and Dissertations, Fall 2023 to Present

Algal biofilms have numerous applications in wastewater treatment and bioproduct production. The Sustainable Waste-to-Bioproducts Engineering Center at Utah State University is working to develop rotating algal biofilm reactors (RABRs) to remove excess nitrogen and phosphorus from wastewater effluent while producing biomass for downstream production.

Genetic analysis of algal biofilms on various RABRs was performed to gain improved understanding of the biofilm populations. This analysis focuses on a pilot-scale RABR and how it compares to several other RABRs. Additionally, old methods of genetic analysis filtered out important cyanobacterial populations. A new method was developed to identify the cyanobacteria within the biofilms. …

Modeling For Functional Traits In Bluebunch Wheatgrass Using Unmanned Aerial Vehicle (Uav) High-Throughput Phenotyping, Brittany L. Johnson

All Graduate Theses and Dissertations, Fall 2023 to Present

Changing climates and shifts in community composition in the Intermountain West threaten sagebrush-steppe ecosystems, impacting both plants and animals. Restoring native grasses like bluebunch wheatgrass (Pseudoroegneria spicata; BBWG) can help ecosystems resist invasive species and recover from stress and disturbances. As a native cool-season grass, BBWG is widely used in rangeland restoration for the western U.S. Breeding programs for restoration plant materials, such as seeds for ecological projects, often require years or decades of field testing while facing staffing constraints. High- throughput phenotyping (HTP), which rapidly measures observable plant traits, offers a faster solution using drones to capture time-series …

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 …

From Supercomputers To Desktops: An Interactive And Portable System For Particle In Cell Simulation And Visualization Using Commodity Hardware, Kim Peterson

All Graduate Theses and Dissertations, Fall 2023 to Present

Generating and analyzing visual representations of simulation data in real time (i.e., during execution), has become increasingly important for handling the complexity and scale of modern computational models. Traditionally, this approach has been limited to High-Performance Computing (HPC) environments, leaving some researchers, students and educators without resources to explore cutting-edge simulations and analyses. This work attempts to show that powerful scientific simulations and real-time analysis can be made available by using more easily obtained commodity hardware. This approach may enable a broader participation in the scientific computing discovery process.

In this paper, we explore how advanced simulation and visualization frameworks …

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 …

What’S The Beef With Agriculture? Evaluating The Effectiveness Of An Agricultural Literacy Intervention On Students’ Attitudes And Knowledge Toward Sustainability And Animal Agriculture, Jenny E. Bennett

All Graduate Theses and Dissertations, Fall 2023 to Present

Agricultural literacy is essential for helping individuals understand how food systems impact their daily lives and society. While most research has focused on students’ knowledge, this study addresses the underexplored role of attitudes—critical predictors of behavior—as outcomes of educational interventions. This research analyzed survey data collected before and after an agricultural literacy intervention delivered to high school students in school-based agricultural education (SBAE) programs. The curriculum focused on sustainability in animal agriculture.

Findings from paired samples t-tests showed statistically significant improvements in students' attitudes (from moderately neutral to more positive) and knowledge scores. Further analyses revealed that demographic factors such …

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 …

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 …

Soil Health On Utah's Farms And Ranches, Jenae Dean

All Graduate Theses and Dissertations, Fall 2023 to Present

The term soil health has gained popularity in agriculture due to prolonged droughts, rising food costs, and the growing public concern for sustainable and organic practices. Soil health practices can offer solutions to all of these pressures. This thesis provides Utah's farmers and ranchers with quantifiable data on implementing soil health practices in Utah's unique climate. It presents the first two years of on-farm trial results on yield and quality after implementing various soil health practices on five categories of crops: corn, mixed hay, alfalfa, produce, and dryland grain. Over a two-year period, none of the soil health practices resulted …

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 …

Investigating Temporally Dynamic Models Of Choice In Rats And Bumblebees, Jack Van Allsburg

All Graduate Theses and Dissertations, Fall 2023 to Present

Temporally dynamic models of choice simulate how animals use past experience to make optimal decisions in variable environments. Chapter 1 briefly reviews a series of such modeling approaches and their mathematical properties. Extension of these models to longer experiments (more than 48 hours) designed to produce spontaneous recovery of choice (a behavioral phenomenon implicated in relapse) previously led to results not described well by current models. Chapter 2 comprises an empirical investigation of different explanations for these inconsistent results using rats, evaluating the effect of different test delays on preference following varied reward conditions. The results of the first two …

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 …

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 …

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 …

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 …

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 …

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 …

Warfare And Woodlands: Tracing Environmental And Military History In The Hürtgen Forest, Cedar Williams

All Graduate Theses and Dissertations, Fall 2023 to Present

This thesis explores what happens when war enters a forest. From 1944 to 1945, American and German forces fought a long, brutal battle in the Hürtgen Forest near Germany’s western border. The dark, wet, and heavily wooded terrain made the fighting unusually difficult. Soldiers struggled not just with enemy fire, but with freezing rain, deep mud, low visibility, and constant stress. The forest shaped how the battle unfolded and intensified its hardships.

But the war’s impact on the forest continued long after the soldiers left. Unexploded bombs and artillery shells littered the ground. During a heatwave in 1947, many of …

Authentic Digital Writing Parameters In College Composition: Design, Implementation, And Assessment Of A Culture Jam, Mary Ellen Greenwood

All Graduate Theses and Dissertations, Fall 2023 to Present

As technology reshapes communication, college classrooms must adapt to prepare students for writing in a quickly changing world. This dissertation investigates how authentic writing—writing that feels meaningful, relevant, and tied to real-world purposes—can enhance student motivation, confidence, and writing skills in college composition courses.

The study introduces a multimodal assignment called a Culture Jam, where five participants critiqued and remixed media messages, such as advertisements or social media posts, to create their own critical digital compositions. Over three weeks, participants created their Culture Jams, shared feedback with peers, and reflected on their experiences. This project focused on five key elements …

Groundwater-Dependent Ecosystems In Southeastern Utah: An Integrated Analysis Of Hydrology, Ecology, And Landscape Change, Colten Lay

All Graduate Reports and Creative Projects, Fall 2023 to Present

In Southeastern Utah, springs play a critical role in sustaining groundwater-dependent ecosystems (GDEs) in a semi-arid environment. However, they remain understudied and face growing threats from climate change, land use modifications, and hydrologic alterations. This study addresses knowledge gaps in spring occurrence, hydrologic function, and ecological condition by integrating field surveys, remote sensing, and geospatial analysis across multiple spatial scales. It provides a comprehensive assessment of spring hydrology, water quality, and ecological conditions using field surveys, remote sensing, and GIS analysis to establish a foundational baseline of GDE resources in the region. I applied a multi-scale monitoring approach across the …

Challenging The Gaze: A Feminist Interpretation Of The S.M.S. Mail Art Collection, Karissa A. Krievins

All Graduate Reports and Creative Projects, Fall 2023 to Present

In the late 1960s, many people called for radical, immediate change to America’s political, societal, and cultural structures. The artistic practices of the time reflected the social and political realities of the moment and played a crucial role in advocating for change. The title of the 1968 S.M.S. (Shit Must Stop) subscription art portfolios was a bold and urgent call for action, challenging artists and audiences alike to confront the pressing injustices of the era and inspire a collective awakening to the necessity of transformative change across the United States. Despite a fifty-six-year gap, today we are …

Drawing On The Past: Understanding Japanese American Internment Through Camp Newspaper Comics, Rory Olsen

All Graduate Reports and Creative Projects, Fall 2023 to Present

When studying the past, what artifacts are left behind for us to study? In understanding Japanese American internment in the United States during WWII, camp newspapers help give a look at the reality of camp life, which included the ongoing issues of a lack of supplies,, the generational divide between older and younger Japanese Americans, and even the racist leanings of some members of the camp. With a balance of humor and seriousness, as well as reality and the abstract, three artists - Roy Kawamoto, Harry Kuwada, and Michiko "Rosie" Arima - who were interred in Camp Jerome (located near …

The Effects Of Temperature And Cardiotonic Steroids On Cardiac Function And Metabolism In Snakes, Hannah Wilson

All Graduate Theses and Dissertations, Fall 2023 to Present

The function of the heart provides a window into the physiology of vertebrates and a means of evaluating their response to the stresses imposed by diverse activities. I developed a miniaturized instrument to record electrocardiograms (ECGs), using open-source Arduino technology, that a snake can wear as a backpack. The backpack can also be used when the snake is in a metabolic chamber, to record the metabolic rate and ECG simultaneously. I first used the ECG backpack to record the physiology of snakes under different temperature conditions, to verify that the system worked as expected. the backpack was then used on …

Living Pantry: Affordable Housing And Traditional Agriculture, Alanna S. Nafziger

All Graduate Reports and Creative Projects, Fall 2023 to Present

Utah is a beautiful and unique landscape with a vibrant food history that is, as I write this in 2025, undergoing some dramatic changes in both climate and population.

The population is projected to almost double by 2065, increasing by 2.8 million people over a 50-year period. Cache Valley, in the Northern part of the state, is projected to increase its population by 93% in that same time frame (Perlich et. al., 2017).

This population growth represents a huge increase in demand for housing, but while demand grows, the market becomes less affordable, with the median home price 6.26 times …

The Pharmacology Of Gpr171 Ligands In The Treatment Of Pain: An In Vitro And In Vivo Preclinical Characterization, Max V. Mcdermott

All Graduate Theses and Dissertations, Fall 2023 to Present

Opioids are addictive, ineffective for long-term treatment, readily produce withdrawal and tolerance, and can cause overdose and death. These properties have contributed to an epidemic of addiction and overdose, which continues unabated in the United States. Therefore, new drugs to treat acute and chronic pain are needed. Opioids bind to receptors belonging to a superfamily of proteins called G protein-coupled receptors (GPCRs). GPCRs are the most commonly targeted proteins among FDA-approved drugs. As such, under-researched GPCRs are a viable source of new targets in the field of drug development. One such underexplored GPCR is GPR171. Studies have demonstrated that a …

Supplementing Tannins To Increase Performance And Reduce Methane Emissions In Cows Grazing On Western Grasslands, Horacio Pedro Blanchard

All Graduate Theses and Dissertations, Fall 2023 to Present

Cattle grazing on U.S. rangelands often rely on a limited diet made up mostly of grasses. As the seasons change from spring to fall, the nutritional quality of these grasses declines, leading to less efficient digestion and higher production of methane—a potent greenhouse gas. In addition, most grass-based pastures lack beneficial plant compounds, such as tannins.

This study explored whether adding natural tannins—specifically, condensed and hydrolyzable tannins from quebracho and chestnut trees—to the diet of grazing cattle could improve how the use efficiency of nutrients and reducing methane emissions from cattle. Over two years, 24 cow-calf pairs grazed in small …

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 …

Cocoa Polyphenols Alter The Fecal Microbiome Without Mitigating Colitis In Mice Fed Healthy Or Western Basal Diets, Eliza C. Stewart, Mohammed F. Almatani, Marcus Hayden, Giovanni Rompato, Jeremy Case, Samuel Rice, Korry J. Hintze, Abby D. Benninghoff

Animal, Dairy, and Veterinary Science Student Research

Background/Objectives: Chronic inflammation and Western-style diets elevate colorectal cancer (CRC) risk, particularly in individuals with colitis, a feature of inflammatory bowel disease (IBD). Diets rich in polyphenol-containing functional foods, such as cocoa, may reduce gut inflammation and modulate the gut microbiome. This study investigated the impact of cocoa polyphenol (CP) supplementation on inflammation and microbiome composition in mice with colitis, fed either a healthy or Western diet, before, during, and after the onset of disease. We hypothesized that CPs would attenuate inflammation and promote distinct shifts in the microbiome, especially in the context of a Western diet. Methods: …

Equine Pituitary Pars Intermedia Dysfunction (Equine Cushing's Syndrome), Cheyanne Eaton, Karl Hoopes

All Current Publications

Pituitary pars intermedia dysfunction (PPID), also known as equine Cushing’s disease, is an endocrine disorder that affects a horse’s pituitary gland. Involving a veterinarian early in the diagnosis and treatment of PPID will greatly enhance the horse’s welfare and longevity. A veterinarian diagnoses PPID by observing symptoms and testing blood. Treatments for this disease include medicinal intervention and dietary changes.