Digital Commons Network^™

A Stochastic Model For Water-Vegetation Systems And The Effect Of Decreasing Precipitation On Semi-Arid Environments, Shannon A. Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current climate change trends are affecting the magnitude and recurrence of extreme weather events. In particular, several semi-arid regions around the planet are confronting more intense and prolonged lack of precipitation, slowly transforming these regions into deserts. Many mathematical models have been developed for purposes of analyzing vegetation-water interactions, particularly in semi-arid landscapes. Most models are based on the average behavior of the system as a whole, and how it is influenced by external changes. These models may be termed "macro-scale" models. Other models have concerned themselves with the interactions between individuals, in this case the interactions between individual plants …

Establishing A Kinetic Assessment Of Reactive Strength, Talin Louder

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three neuromuscular characteristics are identified in Sheppard and Young’s model of agility: concentric strength and power, bilateral symmetry, and reactive strength. Measures of reactive strength attempt to model the neuromuscular regulation of tissue stress and strain. The Coefficient of Reactivity (CoR) is the first known assessment of neuromuscular reactivity. The CoR was developed as an assessment of neuromuscular performance in drop jumping. The construct validity of the CoR was placed in question when Warren Young proposed the Reactive Strength Index (RSI). The RSI improved the theoretical validity of reactive strength assessment since it included a component measure (ground contact time) …

Do Data Structures Matter? A Simulation Study For Testing The Validity Of Age-Period-Cohort Models, Sun Young Jeon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Age, period, and cohort are three temporal dimensions that can make unique contributions to social and epidemiological changes that occur in populations over time. However, while the theoretical underpinnings for each temporal dimension are well established, the statistical techniques to assess the distinctive contributions of age, period and cohort are controversial. Unless questionable assumptions are imposed on the data, traditional linear regression models are incapable of estimating the independent contribution of each temporal dimension due to the linear dependence between age, period and cohort (A=P-C). Two recently developed methods, Hierarchical Age-Period-Cohort (HAPC) and Intrinsic Estimator (IE) models, enable researchers to …

Spatial And Behavioral Patterns Of Captive Coyotes, Jeffrey T. Schultz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Environmental enrichment is a technique used at many captive animal facilities that can improve the well-being of their animals. It seeks to enhance habitat features and promote natural behavior by providing a variety of practical ways for captive animals to control their environmental settings, especially during stressful circumstances. Enclosure features, such as shelter structures, are one tool that promotes wild behavior by adding complexity to an enclosure’s physical environment. Enrichment efforts for captive wildlife are most effective when they are specialized to the biological needs of the animals. Human activity may alter captive animal behavior and utility of enclosure features, …

Spatial Ecology Of Coyotes And Cougars: Understanding The Influence Of Multiple Prey On The Spatial Interactions Of Two Predators, Peter J. Mahoney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The coyote (Canis latrans) has expanded throughout much of North America over the past century following the regional extirpation of apex predators. These highly adaptable canids can occupy a variety of landscapes from the rainforests of Central America to the dense, human-dominated urban centers of the United States. As a generalist predator, coyotes can capitalize on a variety of food resources, including anthropogenic subsidies such as domestic livestock and food tailings at landfills. These tendencies often bring coyotes in direct conflict with humans, forcing managers to consider mitigation strategies ranging from the targeted removal of problem individuals to …

Hydrocarbon And Co2 Emissions From Oil And Gas Production Well Pad Soils Comparative To Background Soil Emissions In Eastern Utah, Cody S. Watkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

What effect does the development of oil and gas have on the observed air quality (i.e., increased ozone, carbon dioxide (CO₂), volatile organic compounds (VOCs), and/or methane emissions) in northeastern Utah? What percentage of these gases is natural background emissions, and what percentage is due to the recent oil and gas development in the region? Emissions in this text refer to gases released from the earth’s surface to the atmosphere. Methane is the primary compound in natural gas. Natural gas is a naturally occurring hydrocarbon gas mixture. Emissions of methane, non-methane hydrocarbons (NMHC), and CO₂ at 27 …

Evaluating Habitat-Based Niche Requirements And Potential Recruitment Bottlenecks For Imperiled Bluehead Sucker (Catostomus Discobolus), Bryan C. Maloney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to rivers that alter physical and thermal habitat may cause fish population abundance to decline, due to fewer individuals maturing and entering the adult population. The Weber River has become highly degraded with many dams and diversions altering fish habitat, river volume, velocity, and temperature, and limiting movement between reaches. Bluehead suckers (Catostomus discobolus) occupy only 47% of their historical range and the genetically-distinct Weber River (northern UT) population is declining and contains few young, juvenile fish. My objectives were to determine whether spawning and rearing habitat available in the Weber River may be limiting bluehead sucker …

Strategies For Increased Lactic Acid Production From Algal Cake Fermentations At Low Ph By Lactobacillus Casei, Tom J. Overbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We explored using de-oiled algal biomass (algal cake) as a low-value substrate for production of lactic acid in fermentations with Lactobacillus casei, and strategies for increasing lactic acid production at low pH. L. casei 12A algal cake (AC) fermentations showed carbohydrate and amino acid availability limit growth and lactic acid production. These nutritional requirements were effectively addressed with enzymatic hydrolysis of the AC using α-amylase, cellulase, and pepsin. Producing 0.075 g lactic acid per g AC from AC digested with all three enzymes. We explored heterologous expression of the cellulase gene (celE) from Clostridium thermocellum and the …

Sclerocactus Wetlandicus: Habitat Characterization, Seed Germination And Mycorrhizal Analysis, Kourtney T. Harding

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uinta Basin hookless cactus (Sclerocactus wetlandicus) is a threatened species native to Eastern Utah. The cactus is found in a landscape highly disturbed by non-renewable energy production. To understand the environmental conditions that support natural growth of this cactus, we asked what types of plants were present in the same areas as the cactus, and if the types of plants were different in environments that were disturbed. From our assessment, we determined that the types of plants present in disturbed areas were drastically different from those present in undisturbed locations. Areas previously used for energy production are …

Increasing Knowledge And Detection Of Racial And Ethnic Microaggressions In White College Students, Christina A. Patterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Scholars have strongly suggested that to combat microaggressions and their impact on persons of color, there needs to be an increased awareness and ability to detect microaggressions when they occur. There is limited research on how to practically address these concerns. This study examined the efficacy of a multimedia intervention aimed at increasing White individuals’ ability to accurately detect microaggressions. The high-exposure intervention was compared against two other conditions, low-exposure and control, at pre-, post-, and 1-week follow-up from intervention.

Undergraduate university students were recruited from two predominantly white universities (PWU). Participants watched a series of videos to determine if …

Direct And Indirect Effects Of Climate Change On Plant Populations And Communities In Sagebrush Steppe, Andrew R. Kleinhesselink

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid climate change presents humanity with a number of big problems. Foremost among these is the sad fact that the climate we will pass on to our children will likely be nothing like the climate that we inherited from our parents. Ecologists have collected solid evidence that climate change has already begun to affect the living things around us and the ecosystems humans depend on. Unfortunately, predicting the future effects of climate change on life on earth is not easy. We focused on three research goals as part of an effort to improve our ability to predict how plants and …

Environmental Values And Landscape Architecture: A New Ecological Paradigm Study, Emmet J. Pruss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent decades, landscape design theory has been affected by an increase in pro-environmental values. Largely, this trend has been associated with notions of ‘sustainability’ and ‘ecosystem services.’ These notions involve sustaining current human behaviors within the constraints of ecological limits and maximizing the benefits that humans receive from ecosystems, respectively. In this way, they involve high evaluations of the instrumental values of ecosystems, yet remain predominantly anthropocentric. As such, they are characteristic of shallow ecology worldview.

In order to assess whether the pro-environmental, yet essentially anthropocentric values involved with modern landscape architecture theory are reflected in the environmental worldviews …

Foraging Ecology Of Mountain Lions In The Sierra National Forest, California, Bradley C. Nichols

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We conducted this research to gain insight into mountain lion (Puma concolor) prey composition in the Sierra National Forest of California. Managers in the region are concerned with both causes of declines and inability to increase fisher (Pekania pennanti) populations. Research has shown that mountain lions are a threat to fishers due to direct predation of this forest specialist. We radio-collared 5 adult mountain lions in order to determine prey composition and kill rates. As expected, mountain lions selected primarily for mule deer (Odocoileus hemionus). However we did detect other prey such as gray …

Murder Becomes Her: Media Representations Of Murderous Women In America From 1890-1920, Emily M. Crumpton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis explores the relationship between the media, murderous women, and the concept of separate spheres. Murderous women challenged established gender norms. They did not conform to the societal expectations of their gender, therefore, they were not considered “normal.” As such, women like Alice Mitchell, Jane Toppan, and Amy Archer Gilligan became objects of media, medical, and public curiosity. As defined by medical science and society, newspapers policed the boundaries of “normality” by sensationalizing the lives, actions, and trials of deadly damsels. Newspaper coverage of murderous women reminded the public of the consequences of “abnormality” and non-conformity. This thesis argues …

Predicting The Impact Of A Northern Pike (Esox Lucius) Invasion On Endangered June Sucker (Chasmistes Liorus) And Sport Fishes In Utah Lake, Ut, Jamie Reynolds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive species introductions are associated with negative economic and environmental impacts, including reductions in native species populations. Successful invasive species populations often grow rapidly and a new food web structure is established. The ability of invasive species to outcompete and prey upon native species are two characteristics that make them a leading cause of fish extinctions in North America.

Northern pike (Esox lucius; hereafter pike) are voracious ambush top predators \native to the upper Midwest and Mid-Atlantic regions of the lower 48 United States, Alaska, and southern Canada. Pike have been spreading across the Intermountain West and Pacific …

Great Basin Bristlecone Pine Resistance To Mountain Pine Beetle: An Evaluation Of Dendroctonus Ponderosae Host Selection Behavior And Reproductive Success In Pinus Longaeva, Erika L. Eidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (Dendroctonus ponderosae) is a native bark beetle that attacks and kills most species of pines (Pinus) throughout its range in western North America. Due to the strong relationship between thermal conditions and mountain pine beetle population success, climate change-induced changes in mountain pine beetle outbreaks are a major concern for land managers. Over the past several decades, warmer than average temperatures allowed mountain pine beetle populations to reach epidemic levels across much of the western U.S. and Canada, including high elevations where outbreaks were previously limited by cool temperatures. Many high-elevation pine …

Identifying The Underlying Components Of Delay Discounting Using Latent Factor Modeling, W. Brady Dehart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many problematic behaviors can be conceptualized as choosing a smaller, immediate outcome over a larger, delayed outcome. For example, drug abuse involves choosing between the immediate euphoric effects of the drug and the delayed health and legal consequences of drug abuse. Individuals that consistently choose the smaller outcome are said to behavior “impulsively.” The goal of this dissertation was to understand how to change impulsive choice. Chapters 2 and 3 successfully demonstrate that impulsive choice can be altered by reframing how the choice is presented. For example, framing a delayed outcome using a specific date instead of a duration of …

Water Entry Impact Dynamics Of Diving Birds, Saberul Islam Sharker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plunge diving and surface diving are two main techniques used by seabirds for foraging purposes. While some plunge divers can dive into the water at very high speeds (24 m/s), surface divers do not. This study analyzes the free-surface impact of 3D printed bird head models with embedded accelerometers to determine why surface divers cannot dive safely at high speeds. The problem is investigated in the context of impact jerk where surface divers, unlike plunge divers, are found to experience non-dimensional jerk (J^∗) values exceeding a safe limit. This approach portrays itself as an unconventional yet effective method …

The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …

First-Row Transition Metal Sulfides And Phosphides As Competent Electrocatalysts For Water Splitting, Nan Jiang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar energy is a carbon-neutral and renewable energy resource. Its nature of intermittence and unequal distribution requires efficient solar energy capture, conversion, and storage. Solar-driven water splitting to produce hydrogen and oxygen is widely considered as an appealing approach to meet this goal, in which hydrogen acts as a green energy carrier. Water splitting consists of two redox half reactions: hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Both reactions involve the transfer of multiple electrons and protons and possess high energy barriers to proceed at appreciable rates, hence catalysts are needed.

A large number of HER and OER …

To What Extent Might Beaver Dam Building Buffer Water Storage Losses Associated With A Declining Snowpack?, Konrad Hafen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dams built by North American Beaver create natural water storage and slow water as it moves through streams. In portions of streams with beaver dams, these effects have been observed to decrease the peak magnitude of floods and increase base flow during annual summer droughts. In the western United States changes to streamflow patterns have been observed in recent decades with large spring floods coming earlier in the year, causing annual summer droughts to start earlier and last longer. These changes are linked to decreasing snowpack which acts as the most significant natural water storage reservoir by holding onto precipitation …

Participation In Dual Language Immersion Programs: Using Theory Of Planned Behavior To Predict Enrollment, Andrea Call

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many theories have been developed to help explain and predict human behavior. Ajzen’s Theory of Planned Behavior (TPB) holds that behavior is based on behavioral intention, as well as attitudes, subjective (or social) norms, and perceived behavioral control. According to the TPB mode, perceived behavioral control moderates (or influences) the effect of behavioral intentions on behavior. Previous research has focused on the application of TPB to health behaviors, although some research has been done in educational situations. In addition, dual language immersion (DLI) programs are increasing in popularity, particularly in Utah. The Utah model begins in first grade, and follows …

Comparing The Effect Of Carbon Sources, Lactate And Whey, On Biological Reductive Dechlorination Of Tce In Laboratory Flow Through Columns, Sarah M. Kissell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Trichloroethylene (TCE) is a chlorinated solvent most commonly used as an industrial degreaser for cleaning mechanical equipment. Historic improper management and disposal of TCE has resulted in contaminated soil and groundwater across the United States, including Hill Air Force Base in Utah. The abundance of TCE in the environment presents a public health risk because it is categorized as a Group 1 carcinogen by the International Agency for Research on Cancer (IARC).

The purpose of this study was to improve the bioremediation techniques of biostimulation and bioaugmentation. A continuous flow-through column study was performed where columns packed with aquifer material …

A Parallel Genetic Algorithm For Optimizing Multicellular Models Applied To Biofilm Wrinkling, Christopher Douglas Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiscale computational models integrating sub-cellular, cellular, and multicellular levels can be powerful tools that help researchers replicate, understand, and predict multicellular biological phenomena. To leverage their potential, these models need correct parameter values, which specify cellular physiology and affect multicellular outcomes. This work presents a robust parameter optimization method, utilizing a parallel and distributed genetic-algorithm software package. A genetic algorithm was chosen because of its superiority in fitting complex functions for which mathematical techniques are less suited. Searching for optimal parameters proceeds by comparing the multicellular behavior of a simulated system to that of a real biological system on the …

Conservative Tryptophan Mutations In Protein Tyrosine Phosphatase Ptp1b And Its Effect On Catalytic Rate And Chemical Reaction, Teisha Richan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein-tyrosine phosphatases (PTPs) catalyze the hydrolysis of phosphorylated tyrosines by a 2-step mechanism involving nucleophilic attack by cysteine and general acid catalysis by aspartic acid. In most PTPs the aspartic acid resides on a flexible protein loop, consisting of about a dozen residues, called the WPD loop. PTP catalysis rates span several orders of magnitude, and differences in WPD loop dynamics have recently been show to correlate with the rate of enzymatic catalysis. The rate of WPD loop motion could possibly be related to a widely conserved tryptophan residue on the WPD loop. Therefore, point mutants were made in PTP1B …

Production Of Phenol-Formaldehyde Adhesives From Catalytic Pyrolysis Oil, Angela M. Akude

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phenol-formaldehyde adhesives conventionally synthesized from fossil fuel resources pose two major concerns: sustainability issues and environmental concerns. The sustainability issues arise from the inevitable depletion of fossil fuel resources while
the environmental concerns, primarily, stem from the emission of volatile organic compounds. Thus, opting for alternative raw materials from renewable resources reduces the dependence on fossil fuels as well as promote the production of environmentally-friendly products.

The successful commercialization of bio-adhesives requires that the substitution of phenol with bio-oil during resin synthesis should be above 40%. In this study, catalytic pyrolysis oil produced from pinyon-juniper biomass and red mud alumina …

Effect Of N-3 And N-6 Polyunsaturated Fatty Acids On Inflammation, Tao Xu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Intake of polyunsaturated fatty acids (PUFA) has changed drastically in the past century in the American diet has received attention due to potential effects on chronic inflammation-related metabolic diseases. In this project, the effects of dietary PUFA content and the n-6 to n-3 ratio on inflammatory responses in the acute and chronic inflammation models were evaluated. The PUFA content was modified on a Western diet background to deliver both n-6 and n-3 intakes at the 10^th and 90^th percentile of the population in the United States, and models of acute and chronic inflammation were tested in mice model. …

Mechanism Of Substrate Reduction By Nitrogenase, Nimesh Khadka

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen (N) is a vital element of life and the main component of chemical fertilizer. The industrial Haber-Bosch process fulfills the demands of today’s nitrogen need and is therefore considered as one of the major scientific breakthroughs of the last century. However, the Haber-Bosch process operates at very high temperature and pressure, and requires fossils fuels to drive the reaction, making it an energy expensive process. The energy demand for this process accounts for almost 3% of the total global energy consumption. In addition, the rapid population growth, economic development and depletion of limited non-renewable fossil fuels have already created …

The Behavior And Ecology Of Cursorial Predators And Dangerous Prey: Integrating Behavioral Mechanisms With Population-Level Patterns In Large Mammal Systems, Aimee Tallian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Driving into Yellowstone National Park for the first time is a moving experience. Gazing over the sweeping landscapes, seeing a geyser erupt 80 feet into the air, and having your first ‘wildlife encounter’, whether that be a 2 ton bull bison aggressively wallowing on his dirt mound, snorting and kicking up dust, or watching a pack of 6 wolves move through a valley off in the distance, pausing to howl in search of their companions. Yellowstone staff wishes to manage our park in a way that preserves these remarkable experiences. In order to effectively manage this dynamic ecosystem, it is …

Adolescent Relationship Concerns And Perceived Gains From A Relationship Education Course, Jenny Harris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted with survey data drawn from a relationship education initiative in the state of Utah. Teenagers participated in the Premarital Interpersonal Choices and Knowledge (PICK) program (also known as How to Avoid Falling for a Jerk or Jerk-ette), a program designed for single individuals. They answered questions before and after the course, and I used their responses to answer two questions: (1) What concerns do middle-adolescents (ages 15-17) have about romantic relationships? (2) What do middle-adolescents gain from participation in PICK?

Data from 605 participants were combined and analyzed for themes. Teenage participants expressed concerns about …