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The Inevitable Fusion: A Mixed-Methods Sociological Approach To Comprehensive Kodiak Bear Viewing Management, Jacqueline M. Keating

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Kodiak National Wildlife Refuge is home to one of the highest concentrations of brown bears in Alaska. As the public demand for bear viewing opportunities continues to increase, managers are faced with the challenge of accommodating this new kind of visitor use on a refuge that was traditionally managed for the sustainable hunting of bears. To inform the public use management planning process, the Kodiak Refuge allocated funding to support social science research that objectively assessed the current nature of bear viewing opportunities and the factors that influence the quality of those opportunities. Ecologist Aldo Leopold claimed that the …

Anaerobic Digestion Of Wastewater: Effects Of Inoculants And Nutrient Management On Biomethane Production And Treatment, Jason Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to population expiation and the increased awareness of the impact on the environment by wastewater treatment, improved wastewater treatment systems are needed to treat municipal and agricultural wastewater. Treating wastewater with oxygen decreases carbon compounds at the expense of energy to move carbon and oxygen to be in contact with each other. Anaerobic digestion of wastewater can reduce the cost by utilizing microbes to treat high amounts of carbon in wastewater without the need for extensive oxygen requirement. With a proper balance of nutrients, microbes also produce methane, a renewable energy source.

It has been suggested that microalgae be …

Role Of Atp Hydrolysis And Mechanism Of Substrate Reduction In Nitrogenase, Sudipta Shaw

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is essential for life on earth as it is a major constituent of amino acids and nucleic acids. Nitrogen gas (N₂) is the most abundant form of nitrogen in the atmosphere but the strong N≡N bond makes it unavailable for most organisms. Certain prokaryotes known as diazotrophs possess the unique ability to convert N₂ to ammonia (NH₃) which can be utilized by other organisms as a source of nitrogen. The diazotrophs perform this difficult reaction with the help of a complex metalloenzyme, nitrogenase. This enzyme is a major contributor of the fixed source of …

Understanding The Mechanisms Of Insecticide Resistance In Phlebotomus Papatasi And Lutzoymia Longipalpis Sand Flies (Diptera: Psychodidae: Phlebotominae), David Denlinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sand flies, like mosquitoes, ticks, fleas, and lice, transmit pathogens that cause disease in humans. Leishmaniasis, caused by pathogens transmitted by sand flies, kills tens of thousands of people every year. Insecticides have been used to control sand flies, but there is evidence of insecticide resistance in populations of sand flies around the world. The goal of this dissertation was to develop tools to maintain sand flies in the laboratory, develop the ability to identify insecticide-resistant populations of sand flies, and to investigate the genetic mechanisms of how sand flies become resistant to insecticides. I began by comparing live animal …

Effects Of Computer Simulation And Animation (Csa) On Students’ Problem Solving In Engineering Dynamics: What And How, Seyed Mohammad Tajvidi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Previous studies have shown that in many fields, computer simulation and animation (CSA) improve students’ learning and problem solving. However, despite the massive body of research on the role of computers in education, little research has been conducted to qualitatively examine how they affect the learning of engineering students. The purpose of this study was to explore how learning and problem solving were affected by computer modules and what similarities and differences existed between computer representations and paper-based examples.

An analysis of collected data, observations of participants’ problem-solving activities, and interviews revealed that computers can enhance students’ analytical thinking, organizing, …

Effects Of Variable And Changing Environments On Demography: Inferences From A Lesser Snow Goose Colony, David T. Iles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mean and variability of environmental conditions have changed as a result of human activity, and continued changes are predicted. The strongest effects on natural populations will often be channeled through species interactions, as shifts in species range limits and life cycle schedules will shift in relation to each other. These changes will often impact rates of survival, growth, and reproduction simultaneously, and these effects will likely differ across habitats.

In chapter 2, I used mathematical modeling and computer simulations to investigate the evolutionary significance of increasingly variable environments, and examine how evolutionary pressures change when multiple vital rates are …

Increasing Student Engagement And Knowledge Retention In An Entry-Level General Nutrition Course With Technology And Innovative Use Of A Graduate-Level Teaching Assistant, Minhee Kang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Blended-design courses integrate both face-to-face and online learning. This thesis discusses the use of three teaching innovations and their effect on student engagement and course satisfaction in a blended-design nutrition course. The three teaching innovations include 1) a web-based learning platform, called Connect (published by McGraw-Hill Education) 2) other easily accessible technological tools (such as Google+), and 3) higher-level use of a graduate-level teaching assistant.

Another form of web-based learning platform, Mastering, published by Pearson Education, was use previously in the course. However, students, especially those earning the highest grades in the course, did not see value in completing these …

Molecular And Physiological Mechanisms Of Toxin Resistance In Toad-Eating Snakes, Shabnam Mohammadi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many plants and animals are defended by toxic compounds, and circumvention of those defenses often has involved the evolution of elaborate mechanisms for tolerance or resistance of the toxins. Toads synthesize potent cardiotonic steroids known as bufadienolides (BDs) from cholesterol and store those toxins in high concentrations in their cutaneous glands. Those toxins protect toads from the majority of predators, including most snakes that readily consume other species of frogs. BDs exert their effect by inhibiting ion transport by the Na⁺/K⁺-ATPase (NKA). This ubiquitous transmembrane enzyme consists of a catalytic alpha-subunit, which carries out the enzyme's …

The Role Of The Fatty Acid Signaling Pathway In Dietary-Induced Obesity, Melissa N. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, dietary fat has been shown to be capable of activing taste receptor cells in the tongue. Fatty acids (FAs), which act as the chemical cue and are found in dietary fat, activate a cellular signaling pathway that results in a unique signal being sent to the brain that is then interpreted as the taste of fat. One important element in this pathway is the ion channel TrpM5. It is responsible for depolarizing the taste cells that are activated by fatty acids; depolarization is an essential step in cellular response, making TrpM5 essential in the functioning of the …

Modeling De Novo Granulation Of Anaerobic Sludge, Honey Varghese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The global market for biological waste water treatment is large and growing. Bioengineered reactor setups employ microorganisms to degrade waste and produce useful/less harmful components. Scientists are interested in studies that reveal the biological mechanisms involved in the process of these microbial actions in order to improve the reactor performance. The process of granulation in aerobic sludge is one such interesting process which is less explained.

The primary goal of the thesis is to design a computational model that simulates the process of granulation in anaerobic sludge and that addresses the role physiochemical and biological processes play in granule formation. …

The Performance Of A Bioenergetics Model In A System With An Abundant Population Of Salmonids: A Case Study Of Cutthroat Trout In The Logan River, Utah, Martha L. Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Widespread habitat degradation and fragmentation has significantly altered the distribution and abundance of salmonids across the Western United States. To effectively conserve these fish, managers need tools to evaluate habitat quality in physically diverse streams and watersheds. Traditionally, habitat assessment for stream fish has focused on the physical characteristics of sites. Thus, such research has often overlooked important biological factors, such as the availability of prey or the presence and abundance of competitors or predators. In recent years, however, researchers have considered habitat from both physical and biological dimensions.

Bioenergetics models offer a way to combine the both the biotic …

Algae-Based Biofilm Productivity And Treatment Of Dairy Wastewater: Effects Of Temperature And Organic Carbon Concentration, Zachary T. Fica

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Production of dairy and associated products is a source of millions of gallons of wastewater every year. Water used in cleaning feeding stalls as well as the liquid component of the animal waste are two of the major volumetric components of this wastewater. This water is nutrient rich, often limiting the viability as a land applied fertilizer. However, these same nutrients could be used as an inexpensive feedstock for the cultivation of algae, which can then be used to produce downstream products including animal feed and aquaculture.

As part of this study, algal biomass was cultivated on dairy wastewater from …

Interactions Between Plant Water-Stress And Neonicotinoid Insecticides On Spider Mite Infestations In Corn, Alice Ruckert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider mites (Acari: Tetranychidae) are an important agricultural pest of many crops and landscape plants. They can reproduce rapidly and quickly develop resistance to many pesticides, making them difficult to manage. Plant water-stress and high temperatures promote spider mite infestations, while spider mite outbreaks can also result from neonicotinoid insecticide applications. Drought is predicted to increase in the Intermountain West due to increases in temperature and reduced frequency of precipitation events in the region, and neonicotinoids are currently one of the most widely used classes of insecticides in field crops. I studied the interactive effect of these two simultaneously occurring …

Effect Of Foliage And Root Carbon Quantity, Quality, And Fluxes On Soil Organic Carbon Stabilization In Montane Aspen And Conifer Stands In Utah, Antra Boča

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic carbon (SOC) positively affects many soil properties (e.g., fertility and water holding capacity), and the amount of carbon (C) in soil exceeds the amount in the atmosphere by about three times. Forest soils store as much C as is found in trees. Tree species differ in their effect on SOC pools. Quaking aspen forests in the Western US often store more stable SOC in the mineral soil than nearby conifers. During the last decades a decline in aspen cover, often followed by conifer encroachment, has been documented. A shift from aspen to conifer overstories may negatively affect the …

Nitrogen Excretion Of Lactating Dairy Cows Fed An Alfalfa Hay- Or Birdsfoot Trefoil Hay-Based High-Forage Diet, Mohammad Ghelich Khan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Legumes that contain condensed tannins (CT) may have lower protein degradability than alfalfa. The present study investigated the effects of feeding birdsfoot trefoil (Lotus corniculatus L.) hay on lactation performance and N utilization. Eight multiparous Holstein cows in mid lactation (150 ± 22.3 d-in-milk) were randomly assigned to 1 of 2 rations [alfalfa hay-based TMR (AHT) or birdsfoot trefoil hay-based TMR (BFTT)] in a crossover design with 2 experimental periods. Each experimental period lasted 16 d (14 d of adaptation and 2 d of total collection), and the 2 experimental periods were separated by a 7-d washout period. In the …

Statistical Techniques To Model And Optimize Performance Of Scientific, Numerically Intensive Workloads, Steena Dominica Steven Monteiro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Projecting performance of applications and hardware is important to several market segments—hardware designers, software developers, supercomputing centers, and end users. Hardware designers estimate performance of current applications on future systems when designing new hardware. Software developers make performance estimates to evaluate performance of their code on different architectures and input datasets. Supercomputing centers try to optimize the process of matching computing resources to computing needs. End users requesting time on supercomputers must provide estimates of their application’s run time, and incorrect estimates can lead to wasted supercomputing resources and time. However, application performance is challenging to predict because it is …

Simple Soil Quality Tests And Organic Management Practices For Orchards In The Intermountain West, Esther Oline Thomsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil health is often overlooked as a long-term management strategy as growers face an increasing number of short-term management challenges in the Intermountain West. The costs of inputs are rising and water resources are becoming more limited. Soil with poor health typically requires more amendments and fertlizers to meet crop needs. Soil health tests can help reveal management practices that reduce soil health, as well as those that improve soil health. Practices known to improve soil health are reduced to no tillage, cover crop use- especially legumes, and addition of mulch and other organic materials. Soil health testing is not …

Development Of A Student-Perspective Based Scale On Instructor Approachability, Xin Zhao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Students respond to instructor characteristics. Instructor approachability is one such characteristic that is often discussed yet inconsistently defined in the literature. The purpose of this study was to construct and validate a new measure, the Instructor Approachability Scale. The present study used a rationally derived process to generate a list of items that are representative of instructor approachability. Factor analysis was conducted to establish psychometrics for the scale. Regression analyses were then conducted to examine the impact of instructor approachability on several outcomes, including students’ help-seeking attitudes, satisfaction with the course, and mastery of course content. Several significant main …

Characterization Of The Substrate Interactions And Regulation Of Protein Arginine Methyltransferase, Yalemi Morales

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein arginine methylation is a posttranslational modification catalyzed by the family of proteins known as the protein arginine methyltransferases (PRMTs). Thousands of methylated arginines have been found in mammalian cells. Many targets of arginine regulation are involved in important cellular processes like transcription, RNA transport and processing, translation, cellular signaling, and DNA repair. Since PRMT dysregulation has been linked to a variety of disease states, understanding how the activity of the PRMTs is regulated is of paramount importance. PRMT1 is the predominant PRMT, responsible for about 85% of all arginine methylation in cells, but very little is known about how …

Laboratory Experiences In Mathematical Biology For Post-Secondary Mathematics Students, Matthew Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In addition to the memorization, algorithmic skills and vocabulary which is the default focus in many mathematics classrooms, professional mathematicians are expected to creatively apply known techniques, construct new mathematical approaches and communicate with and about mathematics. We propose that students can learn these professional, higher level skills through Laboratory Experiences in Mathematical Biology (LEMBs) which put students in the role of mathematics researcher creating mathematics to describe and understand biological data. LEMBs are constructed so they require no specialized equipment and can easily be run in the context of a college math class. Students collect data and develop mathematical …

Oocyte Quality: Molecular Constituents Altered In The Oocyte Due To Various Environmental Factors, Lindsay Cox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An estimated 1.6 million American couples struggle with infertility. Some causes for poor fertility can be clearly defined but in many instances, subfertility is unexplained. Poor oocyte quality is now considered to be a main contributing factor for many causes of infertility. Good oocyte quality is crucial for many processes including embryo development and maintaining pregnancy. There is a possibility that any alterations to the oocyte can have long lasting effects on embryo development and the health of the offspring. The oocyte is very sensitive to any perturbations to its surrounding environment. Transcripts for apoptosis inhibitors and epigenetic modifiers were …

Invasive Coqui Frogs Serve As Novel Prey For Birds In Hawaii, And Not As Competitors, Robyn L. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Puerto Rican coqui frog was introduced the Hawaiian Islands in the late 1980s. Because of the frog's loud call and high abundance, the State of Hawaii has spent millions of dollars on its eradication. Conservationists are also concerned that the frog could negatively impact Hawaii's endemic birds, which are already threatened by a host of other invasive species, either by competing with them for insects or by increasing bird predators. The purpose of this research was to investigate the impacts of coquis on Hawaiian birds. First, we examined overlap in prey resources between coquis and birds, and second, we …

An Examination Of How Qualitatively Different Delayed Outcomes Are Discounted, Jonathan E. Friedel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Jonathan E. Friedel, a graduate student in the Experimental and Applied Psychological Sciences program at Utah State University, will complete this dissertation as part of the requirements of the degree of Doctor of Philosophy in Psychology.

Outcomes that are received far in the future are less valuable than outcomes that are to be received more proximally. Delay discounting describes how outcomes in the future lose value. The goal of this dissertation is to examine how people discount different types of delayed outcomes. Two experiments examine the value of a wide
variety of delayed outcomes for cigarette smokers and nonsmokers. These …

Evapotranspiration Estimation: A Study Of Methods In The Western United States, Clayton S. Lewis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Theoretical water use of well-watered vegetation in the western United States was investigated by comparing a gridded dataset developed from satellite and ground instruments to weather stations representative of irrigated agricultural conditions. Since wetter environments are cooler and therefore subject to lower levels of evaporation than the same scenario with warmer temperatures, models derived from dryland and often populated areas overestimate potential plant needs in semi-arid or arid conditions. Evaluation of the model revealed an acceptable fit for air temperatures and solar radiation but with less confidence in humidity and wind speeds. Ultimately, the last two parameters were minor components …

Effects Of Thermosonication On Microbial Population Reduction And Solubility Index In Skim Milk Powder, Nicola F. Beatty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermosonication has been researched as a means to improve shelf life, quality, and functional properties in dairy products. This study explored the effects of thermosonication on the inactivation of Geobacillus stearothermophilus in concentrated skim milk as a function of total solids content, temperature, and time and investigated changes in the solubility of the skim milk. Results showed thermosonication had an increased bactericidal effect on both vegetative cells and spores as compared to heat treatment alone without affecting solubility. A model was developed using response surface analysis showing that log reductions produced by thermosonication can be predicted based on a polynomial …

The Demography And Determinants Of Population Growth In Utah Moose (Alces Alces Shirasi), Joel S. Ruprecht

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Moose (Alces alces) occur widely in northern regions of the world. Across their distribution, the species is considered to be of high intrinsic, ecological and recreational value. Populations of moose along their southern range limit in North America have shown erratic population dynamics in recent decades including severe numeric declines in some areas. Moose in Utah belong to the Shiras subspecies, which is a relatively understudied population segment. Additionally, moose in Utah represent the southernmost naturally occurring moose populations worldwide. Concerns over possible declines and a paucity of baseline data on moose within the state prompted the Utah …

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Analysis And Modeling Of Pedestrian Walking Behaviors Involving Individuals With Disabilities, Mohammad Sadra Sharifi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Walking facilities like walkways and stairs are important infrastructures which must be designed to effectively accommodate the behavior of pedestrians. Heterogeneity in pedestrian composition is one important factor generally overlooked in walking facility design guidelines and handbooks. While individuals with disabilities constitute a significant portion of the population in the United States, they are often overlooked due to lack of available data. To remedy this, large scale controlled walking experiments were performed at Utah State University (USU) to study the walking behavior of various types of individuals with disabilities (including vision and mobility impairments) in different walking environments. These environments …

Examining The Effects Of Caregiver Coping Strategies On Care Recipient Outcomes, Joseph S. Wanzek

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dementia is a progressive syndrome with declines in cognitive and functional abilities. As the world’s population becomes increasingly older, prevalence rates are expected to increase exponentially to over 80 million affected by the year 2040. Individuals with dementia and their caregivers experience various difficulties associated with progression that increases stress for both parties. Caregiving can be burdensome and caregivers may employ a number of strategies to manage problems as they arise. Renewed interest has been focused on the care environment as one way to modify dementia progression as caregivers can be an influential person in the care recipient’s life. Two …

Refining Methods For Quantifying Macroinvertebrate Estimates Of Preference For Use In Stream Bioassessments, Ellen F. Wakeley Tomlinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two-thirds of United States stream length is in either fair or poor biological condition. However, we do not yet have reliable, quantitative tools to diagnose site-specific causes of biological impairment. One way to diagnose causes of impairment is to compare the environmental tolerances or preferences of the taxa expected at a site to those of the observed community. Stream ecologists have derived tolerance values (TVs) from field data for use in causal analysis, but inconsistencies across studies cast doubt on the accuracy of these TVs. Published TVs may not agree with one another for several reasons, including: differences in the …