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The Relationship Of Acculturation And Acculturative Stress In Latina/O Youths’ Psychosocial Functioning, Marsha Tafoya

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted to better understand how acculturation and acculturative stress are related to self-esteem, depression, substance use, and substance use problems in 206 Latina/o youth. Acculturation is the social and psychological process of change that occurs when an individual or group comes in contact with a different culture. The acculturation process can be positive, improving one’s life chances in the new culture, or it could be negative due to the challenging nature of change and adaptation to new cultural and social expectations. This difficulty creates a type of stress, called acculturative stress that has been found to be …

The Effects Of 24r, 25-Dihydroxyvitamin D3 And 24s, 25-Dihydroxyvitamin D3 On Phosphate Transport In Vivo, Yu Meng

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research studied the effects of the two isomers of 24,25(OH)₂D₃ on phosphate absorption in vivo to increase our understanding of the effects of 24,25(OH)₂D₃ on phosphate transport in vivo, and its two isomers. The current work demonstrates that 24R,25(OH)₂D₃ is capable of decreasing phosphate absorption after a 1h injection in vivo and 24S,25(OH)₂D₃ can increase phosphate absorption after a 5h injection, but this stimulation disappears at time points after 5h.

Since 24,25(OH)₂D₃ is made in vitamin D-replete animals, the observation that 24R,25(OH)₂D …

The Biogeography Of Marbled Godwit (Limosa Fedoa) Populations In North America, Bridget E. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mission of the U.S. Fish and Wildlife Service (USFWS) is working with others to conserve, protect, and enhance fish, wildlife, plants, and their habitats for the continuing benefit of the American people. Toward fulfillment of that mission, a priority of the USFWS is conservation and management of migratory birds. Effective conservation actions to ensure the continued existence of a species on the landscape cannot be designed without first understanding basic life history characteristics of a species. It is common in the case of migratory birds, that we lack understanding of some of their elemental biological traits.

The Marbled Godwit, …

Causes And Consequences Of Plant Spatial Patterns On Natural And Experimental Great Basin (Usa) Plant Communities, Andrew P. Rayburn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The processes by which plant spatial patterns are formed, and the effects of those patterns on plant community dynamics, remain important areas of research in plant ecology. Plant spatial pattern formation has been linked to many ecological processes that act to structure plant communities at different spatiotemporal scales. Past studies of pattern formation are common, but recent methodological advances in data collection and analysis have permitted researchers to conduct more advanced observational studies of pattern formation in space and time. While studies of the effects of plant spatial patterns were formally rare, they have increased in the last decade as …

Analysis Of The Import, Export, And Bioavailability Of Nitrogen And Phosphorus Within Pineview Reservoir, Brady K. Worwood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was conducted to provide new and useful data about Pineview Reservoir and its watershed, produce water and phosphorus (P) budgets for Pineview Reservoir, test the validity of conclusions made in the Pineview Reservoir Total Maximum Daily Loading (TMDL) document, and create estimates of nitrogen (N) loading to the reservoir from both surface and ground water sources. The production of the water and P budgets, as well as the N loading estimates, was accomplished by measuring flow, nitrate, ammonium, total phosphorus (TP), and soluble reactive phosphorus (SRP) that was entering and exiting the reservoir through surface water sources and …

Optimization Of A Low Reynold's Number 2-D Inflatable Airfoil Section, Todd A. Johansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A stand-alone genetic algorithm (GA) and an surrogate-based optimization (SBO) combined with a GA were compared for accuracy and performance. Comparisons took place using the Ackley Function and Rastrigin's Function, two functions with multiple local maxima and minima that could cause problems for more traditional optimization methods, such as a gradient-based method. The GA and SBO with GA were applied to the functions through a fortran interface and it was found that the SBO could use the same number of function evaluations as the GA and achieve at least 5 orders of magnitude greater accuracy through the use of surrogate …

Seasonal Transport Of Suspended Solids And Nutrients Between Bear River And Bear Lake, Cody M. Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I measured inflows and outflows of nutrients and suspended solid through the wetland complex, known as Dingle Marsh, at the Bear River Migratory Bird Refuge between October 2007 and September 2008. My analysis of changes throughout the year will help Dingle Marsh managers adjust the timing and volume of water movement between Bear River and Bear Lake to meet defined refuge goals, such as improving bird or other animal habitat. These results could also be used to protect Bear Lake’s water quality.

Automated samplers took readings of dissolved oxygen, turbidity, pH and water temperature every 30 minutes. These values were …

Analysis Of Food Web Effects Of Non-Native Fishes And Evaluation Of Stream Restoration Potential For The San Rafael River, Utah, Timothy E. Walsworth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Native fishes of the Colorado River Basin have experienced dramatic reductions in range and abundance as a result of extensive human alterations to the basin’s waterways. Many of these native fishes are federally listed under the Endangered Species Act, while several others are subject to range-wide conservation agreements between state and federal management agencies. Three of the native species subject to range-wide conservation agreements are the flannelmouth sucker, bluehead sucker, and roundtail chub (hereafter, the “three species”). Each of the “three species” is still found in the San Rafael River of southeastern Utah, which has experienced habitat degradation and non-native …

Genetic Status Of Isolated Populations Of Colorado River Cutthroat Trout (Oncorhynchus Clarkii Pleuriticus) In The North Fork Little Snake River Drainage, Wyoming, Rachel Van Horne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Over the last century native cutthroat trout populations have declined in the western United States. Habitat fragmentation is one of the main causes for this decline. Human actions such as the construction of roads, weirs, dams, and water diversions intersect streams and prevent the natural movement of fish. In many cases native cutthroat trout are now confined to headwater streams above human-created barriers. These barriers not only fragment the populations but also increase the risk of individual population extinction.

This study established a baseline genetic structure for nine isolated populations of Colorado River cutthroat trout in the North Fork Little …

Seasonal Influenza Vaccination Disparities Between U.S. Non-Hispanic Whites And Hispanics, 2000-2009, Andrew E. Burger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Seasonal influenza produces substantial disease within the United States every year. Despite the availability of safe and effective vaccines for influenza, millions of individuals go unvaccinated each flu season, with notable differences across racial/ethnic groups. Using the Behavioral Risk Factor Surveillance System (BRFSS), I examine vaccination rates among non-Hispanic whites and Hispanics during the 2000-2009 influenza seasons. After developing a new method that addresses shortcomings of BRFSS vaccination measures, I find that non-Hispanic whites exhibit higher vaccination rates than Hispanics. Through a series of logistic regression models I show that the disparities between non-Hispanic whites and Hispanics narrow after controlling …

Relative Importance Of Environmental Variables For Spawning Cues And Tributary Use By An Adfluvial Lake Sucker, Brian A. Hines

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The endangered June sucker (Chasmistes liorus mictus), which is only found in Utah Lake, UT, historically spawned in all streams flowing into the lake, but due to human-caused changes their spawning is restricted to the Provo River. The purpose of this study was to gain a better understanding of the spawning and early life-history of the
June sucker for recovery purposes. My specific objectives were to determine:

1. what environmental factors attract or deter June suckers to certain Utah Lake tributaries for spawning,
2. what cues June suckers to migrate upstream to spawn,
3. if June suckers use more than one …

Prediction Models For Estimation Of Soil Moisture Content, Swathi Gorthi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Center for Self-Organizing Intelligent Systems (CSOIS) has been successful in developing personal remote sensing systems. These systems can be further enhanced to monitor important resources of earth such as soil moisture content. Soil moisture is the major component of the soil in relation to plant growth. Soil water dissolves salts and makes up the soil solution, which is important as medium for supply of nutrients to growing plants.

Usually, measuring such physical quantities would include using derived formulas that mathematically describe the relationships between the parameters involved. With the advancements in computer modeling, other methods such as empirical modeling …

Designing Predictive Mathematical Models For The Metabolic Pathways Associated With Polyhydroxybutyrate Synthesis In Escherichia Coli, Angela Dixon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plastics are a versatile and widely used material. However, traditional plastics are derived from petrochemicals and are not biodegradable. Polymers synthesized from microorganisms that have similar properties to plastic are potential biodegradable replacements. The objective of this project is to use mathematical modeling as a tool to engineer a strain of bacteria optimized for the production of bio-plastics.

Production costs can be reduced by using a bacterial strain specifically optimized for bio-plastic production. By reducing production costs, bio-plastics will be able to commercially compete with traditional plastics. Society will benefit as bio-plastics replace traditional plastics. Fossil fuels will not be …

Using Species Distribution Models To Assess Invasion Theory And Provide Management Recommendations For Riparian Areas In The Eastern Columbia And Western Missouri River Basins, Diane R. Menuz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Globalization has created opportunities for plant and animal species to be transported to novel ecosystems. A subset of these species become invasive species, which are able to persist and spread rapidly to become influential components in their new ecosystems. Invasive species are often able to out-compete co-occurring native species and can alter fundamental ecosystem properties, such as soil nutrient availability or time between wildfires in a region. The United States is estimated to lose $34 billion per year to invasive plant species through costs to control unwanted species and lowered crop and forage production.

We used statistical models to better …

Rotating Algal Biofilm Reactors: Mathematical Modeling And Lipid Production, Paul A. Woolsey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Harvesting of algal biomass presents a large barrier to the success of biofuels made from algae feedstock. Small cell sizes coupled with dilute concentrations of biomass in lagoon systems make separation an expensive and energy intense-process. The rotating algal biofilm reactor (RABR) has been developed at USU to provide a sustainable technology solution to this issue. Algae cells grown as a biofilm are concentrated in one location for ease of harvesting of high density biomass. A mathematical model of this biofilm system was developed based on data generated from three pilot scale reactors at the City of Logan, Utah wastewater …

Mexican American Youths’ Academic Outcomes: The Role Of Ethnic And Academic Socialization In Buffering Discrimination, Spencer M. Richards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An increasingly diversifying educational landscape in the United States has accompanied distressing academic disparities among ethnic minority youths. As Latinos represent the largest and fastest growing ethnic minority group within the U.S., particular attention to their academic outcomes is warranted. Alarming educational statistics have been reported for Latinos, with some estimating that nearly half fail to complete high school, and only a fraction go on to complete a degree in higher education. As Latinos grow to represent an increasing segment of the American educational system, more attention is required to understand what leads Latinos to engage (or disengage) in the …

Reducing Reliance On Supplemental Winter Feeding In Elk (Cervus Canadensis): An Applied Management Experiment At Deseret Land And Livestock Ranch, Utah, Dax L. Mangus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife managers have fed elk in North America for nearly 100 years. Giving winter feed to elk can compensate for a shortage of natural winter range and may boost elk populations while also helping prevent commingling with livestock and depredation of winter feed intended for livestock. In contrast to these benefits of supplemental feeding, there are economic and environmental costs associated with feeding, and elk herds that winter on feeding grounds have a higher risk of contracting and transmitting disease. Brucellosis is of primary concern now, and Chronic Wasting Disease may be in the future. Many see the discontinuation of …

Zeolite‐Based Algae Biofilm Rotating Photobioreactor For Algae And Biomass Production, Ashton M. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH₃) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N₁₆P₁. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, …

Effect Of Adjunct Cultures, Sodium Gluconate, And Ripening Temperature On Low-Fat Cheddar Cheese Flavor, Rebekah M. Lance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Low-fat Cheddar cheese flavor is different from full-fat Cheddar cheese and is not acceptable to many consumers. This 2-part experiment was designed to examine effects adjunct cultures have on low-fat Cheddar cheese flavor as determined through descriptive analysis and consumer feedback.

In Part 1, low-fat (5%) Cheddar cheese was produced in duplicate, using 6 combinations of DVS850, LH32, CR540, CRL431, Emfour, and CR319 bacterial cultures. Due to a previously observed positive effect by sodium gluconate on low-fat cheese flavor, each replicate was split into treatments of 0.0% and 0.8% sodium gluconate. Each of these treatments was then split into ripening …

Studies Of The Distinguishing Features Of Nadph:2-Ketopropyl-Coenzyme M Oxidoreductase/Carboxylase, An Atypical Member Of The Disulfide/ Oxidoreductase Family Of Enzymes, Melissa A. Beighley-Kofoed

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The metabolism of propylene in Xanthobacter autotrophicus occurs via epoxypropane formation and subsequent metabolism by a three-step, four-enzyme pathway, utilizing the atypical cofactor Coenzyme M (CoM) to form acetoacetate. The last step in the epoxide carboxylase pathway is catalyzed by a distinctive member of the disulfide oxidoreductase (DSOR) family of enzymes, NADPH:2-ketopropyl CoM oxidoreductase/carboxylase (2-KPCC). 2-KPCC catalyzes the unorthodox cleavage of a thioether bond and successive carboxylation of the substrate. The focus of the research presented in this dissertation aims to elucidate the details of 2-KPCC that allow it to perform chemistry unconventional for typical DSOR members. Sitedirected mutagenesis was …

Community Level Effects Of Vegetation Architecture And Prey Availability: A Study Of Ground-Dwelling Arthropods In A Shrub-Steppe Ecosystem, Mary E. Pendergast

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to vegetation architecture within a natural habitat can have profound impacts upon ecological community function, but the relative influence of vegetation architecture itself and potential indirect influences of associated food resources are often difficult to disentangle. I present the results of a three-year study designed to address the community level impacts of changes in big sagebrush (Artemisia tridentata) architecture and associated prey availability upon the ground-dwelling arthropod community. Three experimental sagebrush architecture treatments (low, intermediate, and high foliage density) and two levels of prey insect availability treatment (natural and baited/increased prey availability) were imposed in a sage-steppe …

The Decline And Conservation Status Of North American Bumble Bees, Jonathan B. Koch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several reports of North American bumble bee (Bombus Latreille) decline have been documented across the continent, but no study has fully assessed the geographic scope of decline. In this study I discuss the importance of Natural History Collections (NHC) in estimating historic bumble bee distributions and abundances, as well as in informing current surveys. To estimate changes in distribution and relative abundance I compare historic data assembled from a >73,000 specimen database with a contemporary 3-year survey of North American bumble bees across 382 locations in the contiguous U.S.A. Based on my results, four historically abundant bumble bees, B. …

Ecologically-Based Manipulation Practices For Managing Bromus Tectorum-Infested Rangelands, Beth Fowers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheatgrass (Bromus tectorum) is an invasive annual grass common in several semiarid plant communities in the western U.S. B. tectorum presence increases fire frequency and size, reducing species diversity, and leading to annual species-dominated systems with inconsistent livestock forage potential and degraded wildlife habitat value. Most efforts to manage B. tectorum-dominated rangelands have focused on controlling the plant itself rather than addressing the causes of vegetation change. An alternative approach, ecologically-based invasive plant management (EBIPM), identifies treatments that can alter factors associated with the causes of succession, leading to a more desirable vegetation state. This study utilized …

Testing Mediated Effects Of A Sex Education Program On Youth Sexual Activity, Paul James Birch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Empirical investigations have identified hundreds of factors that predict whether youth engage in sexual activity (YSA). To promote optimal health and the avoidance of unhealthy or problematic outcomes that can result from YSA, sex education programs have been extensively developed and evaluated. Many evaluations have identified the effect of the program on immediate outcomes such as attitudes and intentions, others have examined subsequent behavioral and health outcomes, and some have done both. The purpose of this study was to extend the evaluation literature by testing a mediated effects model. A sex education program was found to have significant immediate effects …

Effects Of Non‐Surface‐Disturbing Treatments For Native Grass Revegetation On Cheatgrass (Bromus Tectorum L.) Metrics And Soil Ion Availabilities, Jan C.R. Summerhays

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Several restoration methods intended to increase the success of aerially‐seeded perennial grasses were assessed to determine their effects on cheatgrass metrics and soil nutrient bioavailabilities. These methods were: 1) imazapic herbicide application (140 g ai ∙ ha^-1, 210 g ai ∙ ha^-1, and no application [control]), 2) vegetation manipulation treatments (50% sagebrush overstory thinning, 100% sagebrush overstory thinning, sagebrush overstory and/or vegetative thatch burning, and no manipulation [control]), and 3) alternative seeding treatments (aerial seeding with raking, aerial seeding with activated carbon [AC] addition, aerial seeding with sucrose addition, and regular aerial seeding [control]). Treatments were …

The Impact Of Team-Based Learning’S Readiness Assurance Process On Virtually Isolated Adults, Matthew W. Barclay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to test the effectiveness of the readiness assurance process of team-based learning (TBL) in virtually isolated settings. Many Internet sites offer courses for adults to use on their own without access to mentors or other learners. However, educational theory suggests that people learn better with others than by themselves. The focus of this investigation was whether the inclusion of the readiness assurance process would increase participants’ levels of learning based on Bloom’s revised taxonomy within the limits of virtual isolation.

In this study an experimental pretest-posttest design was employed. Using a 2- day mini-course …

A Functional Assessment Of The Use Of Virtual Simulations To Train Distance Preservice Special Education Teachers To Conduct Individualized Education Program Team Meetings, Lee Landrum Mason

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The individualized education program (IEP) is a critical component of providing special education services to children with disabilities, outlining the services and modifications that will be provided to help them make progress towards the general curriculum. While simulations have been shown to be an effective means of teaching special education policies and procedures, this can be challenging when working with distance students. The purpose of this study was to identify and examine how virtual simulations function to train preservice teachers learning to conduct IEP team meetings.

Seven preservice special education teachers enrolled in a mild/moderate distance degree and licensure program …

Ungulate Damage To Safflower In San Juan County, Utah, Michael J. Haney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In Utah, farmers are concerned that ungulates are damaging safflower (Carthamus tinctorius) fields. I examined elk (Cervus elaphus) and mule deer (Odocoileus hemionus) damage to safflower production in San Juan County, Utah during 2009 and 2010. Data on damaged safflower plants were collected within 28 fields, totaling 1,581 ha (13 fields totaling 963 ha during 2009; 15 fields totaling 618 ha during 2010). I compared 3 methods to assess losses: ungulate-proof exclosures, adjacent plant compensation method, and counting the number of damaged plants in 50-m transects (safflower count method). Exclosures were of limited use …

Evaluating Fertilizer Rate, Crop Rotation And Trap Crops For Effects On Onion Growth And Yield, Soil Health, Thrips Densities And Iris Yellow Spot Virus Incidence, Kristine R. Buckland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Onion production in the United States is seriously affected by the tospovirus Iris Yellow Spot (IYSV), whose symptoms include lenticular-shaped lesions that reduce photosynthesis and bulb yield. Thrips tabacai Lindeman, onion thrips (OT), is the only known vector of the disease and a primary arthropod pest of onion. Frequent insecticide applications, increasing resistance in OT populations to insecticides, high nitrogen (N) fertilization rates and loss of yield to disease and insect pressure threaten sustainable onion production. The objectives of this study were to identify crop management strategies to enhance onion productivity while suppressing OT and IYSV. Three fertilizer rates and …

Algal Biofilm Production And Harvesting System For Wastewater Treatment With Biofuels By-Products, Logan Christenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Excess nitrogen and phosphorus in discharged wastewaters can lead to downstream eutrophication, ecosystem damage, and impaired water quality that may affect human health. Chemical-based and physical-based technologies are available to remove these nutrients; however, they often consume significant amounts of energy and chemicals, greatly increasing treatment costs. Algae are capable of removing these pollutants through biomass assimilation, and if harvested, can be utilized as a feedstock for biomethane or biodiesel production. Currently, difficulties in harvesting, concentrating, and dewatering algae have limited the development of an economically feasible treatment and production process. When algae are grown as surface-attached biofilms, the biomass …