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Continental-Scale Characterization Of Molecular Variation In Quaking Aspen, Colin M. Callahan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen has the largest natural distribution of any tree native to North America, ranging from Alaska through the breadth of Canada and south to mid-Mexico. Recent studies suggest a general decline of aspen throughout much of the range since at least the mid-20th century, though these findings remain inconclusive. Regardless, factors such as climate change, periods of drought, soil nutrient deficiencies, pathogens, insects, and encroachment by other tree species all pose risks to the health and maintenance of aspen across the continent. This situation is exemplified in the western United States where climate change is forecasted to have an …

Experimental Studies Of Vertical Mixing In An Open Channel Raceway For Algae Biofuel Production, Ram Sudheer Voleti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The USU BioEnergy Center has been successful in developing algae feedstocks for renewable biofuels and bioproducts. The concept is to utilize and maximize algae feedstocks for liquid transportation fuels, biomass for burning and digestion, and high value co-products. It is theorized that increasing the mixing in open and closed algal production systems improves the productivity of the algae culture. A raceway cultivation system was chosen to examine the phenomena of mixing. Vertical mixing will provide more uniform exposure to sunlight for all of the algae in the raceway. The main focus of this research was to increase vertical mixing. Delta …

Genetic Characterization Of Fine-Leaved Festuca Valesiaca Germplasm And Evaluation Of Their Relationship To The Festuca Ovina Complex, Yingmei Ma

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fine-leaved Festuca valesiaca has stress tolerance. However, its agronomic performance in the western United States and its genetic relationship to species of the Festuca ovina complex has not been investigated. Also, natural hybridization makes them difficult to identify. Given the species' potentials, our project was designed to identify Festuca valesiaca accessions that possess high biomass and seed yield and to examine their relatedness with the Festuca ovina complex.

The Festuca valesiaca accessions examined produced many small seeds. Seed production was correlated with the total biomass, plant height, and plant vigor. The Festuca valesiaca accessions examined were shorter than the control …

Estimating Willingness To Pay For Continued Use Of Plastic Grocery Bags And Willingness To Accept For Switching Completely To Reusable Bags, Jarod Dunn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis demonstrates a surveying method to collect data to obtain tax levels for plastic grocery bag usage. This data was collected through asking respondents about a hypothetical situation in which they were required to pay a tax for using plastic bags or whether they would instead switch to using reusable bags that could be purchased at the grocery store. The respondents were also asked if they already were using reusable bags, how much would the store have to pay them for them to use reusable bags for all grocery shopping trips. From our analysis, people who use reusable bags …

Effects Of Planting Date, Harvest Date, And Environmental Conditions On Germination Of Forage Kochia Accessions, Cody F. Creech

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Forage kochia is used to re-seed areas in harsh environments that have been infested by annual weeds or disturbed by repetitive fires. It is an introduced perennial semi-shrub that is valuable to livestock and wildlife as a forage. The seed of forage kochia is very unpredictable and successful establishment in areas of low precipitation where it is utilized has often been erratic. Forage kochia seeding failures are costly and leave the land vulnerable to further degradation and erosion. This study was conducted to investigate how germination of forage kochia is affected by different harvest and planting dates, age of seed, …

A Quantitative Analysis Of Response Elimination And Resurgence Using Rich, Lean, And Thinning Schedules Of Alternative Reinforcement, Mary M. Sweeney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mary M. Sweeney, graduate student in the Experimental and Applied Psychological Science graduate program, proposed and completed this thesis in partial fulfillment for the requirements of the degree of Master of Science of Psychology. This project was supported in part by the American Psychological Society of Graduate Students (APAGS) Basic Psychological Science Fall2010 Research Grant awarded by the members of the APAGS Science Committee.

Many problem behaviors, such as aggression or self-injury in persons with intellectual or developmental disabilities (IDD) or drug abuse can be maintained by the consequences of those behaviors. For example, many instances of aggression in individuals …

Increasing The Retention Of Lipid-Soluble Components In A Curd Matrix, Megan Tippetts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Megan Tippetts, under the direction of Dr. Silvana Martini at Utah State University, proposes to demonstrate that it is possible to increase the retention of lipid-soluble components (e.g. vitamin D) in a curd matrix (e.g. Cheddar cheese). This project was coordinated with the Western Dairy Center for the initial phase of the project.

The initial phase used vitamin D₃ fortified emulsions stabilized with a dairy-based emulsifier. The objective was to determine if vitamin D₃ delivered in an emulsion form to the milk before cheesemake would have higher retention in the cheese versus vitamin D₃ oil added directly …

Productivity Studies Utilizing Recombinant Cho Cells In Stirred-Tank Bioreactors: A Comparative Study Between The Pitch-Blade And The Packed-Bed Bioreactor Systems, Taylor Stephen Hatton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Center for Integrated Biosystems (CIB) at Utah State University proposed to demonstrate the added benefits of bench top stirred-tank bioreactors utilizing the packedbed impeller system in perfusion mode for the production of recombinant proteins. In this study recombinant Chinese Hamster Ovary (CHO) cells were utilized for the production of a secreted protein in two bioreactor types: pitched-blade bioreactor operated in batch mode versus packed-bed bioreactor operated in perfusion mode. Our primary objective was to determine whether the packed-bed bioreactor is superior to a traditional pitched-blade bioreactor for the mass production of cell culture protein products. We hypothesize that the …

Assessments Of An Exogenous Proteolytic Enzyme In Beef Steer Diets To Improve Growth Performance And Ruminal Fermentation, Juan Manuel Vera

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of experiments were conducted to investigate the effects of adding an exogenous proteolytic enzyme (EPE) on growth performance and ruminal fermentation characteristics of beef steers fed growing and finishing diets containing 30% dried distillers grains with solubles (DDGS).

In the first experiment, 48 beef steers were divided into two treatments: DDGS diets with and without EPE. Dry matter intake (DMI) was increased (P = 0.02) by the addition of EPE, but neutral detergent fiber (NDF) digestibility was decreased on the growing phase. For the finishing phase, average daily gain ( …

Effects Of Cache Valley Particulate Matter On Human Lung Cells, Todd L. Watterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

During the wintertime, residents of the Cache Valley are very aware of the poor air quality that occurs during cold-air inversion episodes. If one somehow avoids the radio and television announcements as well as the electronic roadside signs indicating poor air quality and encouraging less driving, one need only to look upward toward the mountains that surround the valley and notice the lack of daytime visibility. This lack of visibility and health warnings are due to particulate air pollution or particulate matter (PM). PM is only one of many types of regulated air pollution but is the one that occurs …

Preventative Behavioral Parent Training: Demonstration Of The Immediacy Effects Of An Innovative Conduct Problem Prevention Program In Young At-Risk Children, Alexis Bolton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Researchers propose to administer preventative behavioral parent training (PBPT) to young children who are displaying developmentally typical conduct problems (i.e., noncompliance and tantrums), with the intent of contributing valuable knowledge for preventing the development of chronic conduct problems in children.

Preventative behavioral parent training is an innovative model designed for conduct problems prevention. The scope of this study will be limited to demonstrating the immediate effects of PBPT. Given the nature and origins of PBPT, immediacy effects are expected and should be relevant to the maintenance of effects over time.

It is predicted that participation in PBPT would yield positive …

Ensuring Microbial Safety In Food Product/Process Development: Alternative Processing Of Meat Products And Pathogen Survival In Low-Salt Cheddar Cheese, Subash Shrestha

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Most outbreaks of foodborne illness in the United States occur as a result of improper food-handling and preparation practices in homes or food establishments. The lack of food-safety knowledge is one of the several reasons for this. However, researchers also suggest that food-operators and consumers with adequate food-safety knowledge, attitudes, and intentions do not always follow the food-safety recommendations because not all recommendations are easy to put into practice. Therefore, the first part of this study sought to establish safe alternative processing of meat products that can be easily practiced by food-operators and consumers. In Chapter 3, a novel method …

The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Composition, Stephanie M. Cobbold

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecologists strive to identify the mechanisms that drive the identity and abundance of species in different locations, because a better understanding of such factors enables them to better predict the effects of habitat modification on organisms, and to identify landscapes in which species are likely to benefit from conservation interventions. However, there is still no consensus on the mechanisms behind geographical variation in species diversity. The primary objective of this dissertation was to focus on spider assemblages to investigate how the fine-scale habitat associations of organisms may drive the composition of their communities at larger scales. Research was conducted in …

Cattle Browsing Sagebrush Steppe During Fall: Effects On Plant Community Structure And Influence Of Experience On Cattle Foraging Behavior And Body Weights, Charles A. Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historic and repetitious spring grazing by livestock, combined with altered fire regimes, has increased the density and abundance of big sagebrush and reduced the frequency of perennial grasses and forbs on many western landscapes. Periodic disturbance is critical for maintaining and improving sagebrush ecosystems. Compared with traditional disturbances – chemical, mechanical, and fire – strategic grazing with livestock offers several benefits. They include creating locally adapted cattle that can rejuvenate sagebrush steppe, which reduces costs associated with mechanical and chemical rejuvenation treatments and feeding cattle during winter, the major cost of ranch operation.

I evaluated the practicality of strategically timed …

Exploring The Reliability And Validity Of The Experiential Discounting Task, Rochelle R. Smits

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Delay discounting is the devaluation of rewards that are delayed in time. This phenomenon was first studied with animals in controlled laboratory environments and later translated to human procedures. Though the decrease in value of outcomes as the delay to receipt increases is the same across species (money for humans, food for animals), a number of methodological concerns have been raised about the procedures used to study delay discounting in humans.

The Experiential Discounting Task (EDT) was recently developed in order to study delay discounting in humans in a way that is more similar to that used with animals. That …

Use Of Rumen Modifiers To Manipulate Ruminal Fermentation And Improve Nutrient Utilization And Lactational Performance Of Dairy Cows, Christopher M. Dschaak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A series of lactation studies reported in this dissertation hypothesized that supplementing different rumen modifiers would have consistent responses on ruminal fermentation and lactational performance under optimal rumen conditions.

The first experiment investigated the influence of magnesium exchanged zeolite on ruminal fermentation and lactational performance. Intake of dry matter (DM), milk yield, milk fat, and feed efficiency were not affected. Milk protein concentration tended (P = 0.15) to be higher for cows fed the zeolite. Ruminal pH tended to increase (P = 0.11) by feeding the sodium bicarbonate or the zeolite.

A second lactation experiment determined …

In Vitro And In Vivo Comparison Of The Pathogenicity Of Four Influenza Virus Strains, Brett L. Hurst

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Influenza viruses cause between 3 and 5 million cases of respiratory infection each year and are responsible for between 250 and 500 thousand deaths. Two avenues for the treatment and prevention of influenza virus infections are vaccination and antiviral chemotherapy. Prevention is largely accomplished through vaccination. While vaccines remain the preferred method for controlling the spread of influenza, antiviral treatment is important for severe infections caused by new and emerging virus strains. Occasionally new viruses emerge to which the population has no previous immunity. Such was the case when the pandemic H1N1 influenza virus appeared in 2009. When new viruses …

Latent Classes Of Self-Reported Adolescent Depression In A Clinical In-Patient Population, Jonathan F. Doti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The depressive disorders are among the most common mental health problems with substantial financial and quality-of-life costs. Depression has generated considerable debate as to the underlying structure/taxonomy and continues to be frequently debated. Adolescents who meet diagnostic criteria for major depressive disorder often experience anxiety (and vice versa). Therefore, understanding the underlying structure of depression as well as the co-occurrence of anxiety in a population of adolescents adds to our conceptual understanding of these disorders and facilitates treatment clarity.

This investigation sought to investigate the following research questions for adolescents’ self-reported symptoms of depression, and self-reported symptoms of depression and …

Increasing Student Voice And Empowerment Through Technology: The Perceptions Of Communication Apprehensive Latter-Day Saint (Lds) Seminary Students, Doran H. Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many students find themselves unwilling or unable to participate vocally in traditional classroom settings. This study examines a group of LDS (members of the Church of Jesus Christ of Latter-day Saints) seminary students who were hesitant to participate vocally in the classroom, but were highly involved in peer-to-peer communication through technology. The objective of this research was to determine the perceived value of technological implementations as it provides a potential forum for increased student participation.

As educators find and utilize teaching methods and resources that engage students more fully in the educational process, the students themselves become the primary beneficiaries. …

Wheat-Gold Currency How To Make Large-Scale Grain Storage Possible, David L. Garrett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States has a National Oil Reserve but no food reserve. Just as the oil reserve is designed to buffer unforeseen disruptions in the critical supply, the nation should also have a food reserve for at least the same purpose.

Biochemical Characterization Of Sac9, A Putative Phosphoinositide Phosphatase In Arabidopsis Thaliana, And Its Role In Cellular Abnormalities, Almut H. Vollmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since the early colonization of land by fungi and plants some 700 million years ago, plants have been continuously faced with changes in their environment. Unlike animals, plants are not free to move about, and can therefore not evade many stress factors. How plants sense and respond to their environment has been of interest not only to scientific research but also in more practical applications such as agriculture.

Signals (such as light or salinity) from the outside of plant cells trigger a flow of information to the inside of the cell. The final target for most of the information is …

Assessment Of Atmospheric Nitrogen Deposition: Possible Effects On Alpine Ecosystems Above 9000 Feet In Grand Teton National Park, Jennifer Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Certain forms of nitrogen (N) in the atmosphere are pollutants with effects that mimic fertilizer application. If there is too much N, it can become a stressor, and the ecosystem may undergo drastic changes (e.g. certain plant species may decline or disappear). The N load at which a system starts exhibiting negative effects is dependent on the type and location of the ecosystem. Alpine ecosystems (i.e. above 9000 feet in Wyoming) may be particularly sensitive to low levels of atmospheric N input because of short growing seasons, sparse plant cover, and shallow soils that limit their ability to absorb the …

Evaluating The Effectiveness Of Three Utah Wastewater Treatment Facilities In Removing Pharmaceuticals And Personal Care Products, Oksana Roth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The occurrence of Pharmaceuticals and Personal Care Products (PPCPs) in surface waters has become a growing concern within the last decade although the first mention of human PPCPs in the environment goes back to late 1970s. Pharmaceuticals include prescription drugs, over-the-counter medications, and veterinary drugs. Personal care products include products such as lotions, fragrances, and soaps. In addition to traditional personal care products, the term PPCPs has been adopted to represent a wide variety of chemicals used in consumer products including plasticizers and fire retardants. Wastewater effluents are thought to be the main source of PPCPs in surface waters since …

Behavioral Mechanisms Of Pramipexole-Induced Impulsivity: Discrimination Processes Underlying Decision-Making, Patrick S. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Impulsivity represents a substantial and devastating cost to our economic, cultural, and physical prosperity. Using quantitative models of choice behavior, researchers are able to identify environmental conditions likely to promote impulsive decision-making. Such an approach is especially valuable in experimental efforts to better understand how drugs negatively affect choice in humans and nonhumans alike. For instance, pramipexole, a dopamine agonist medication prescribed for Parkinson’s disease, has been associated with reports of increased rates of impulsive behavior. By which behavioral mechanisms pramipexole achieves these effects is unknown and requires further investigation.

The research reported herein sought to clarify pramipexole’s effects on …

Drivers Of Nest Success And Stochastic Population Dynamics Of The Common Eider (Somateria Mollissima), David Thomas Iles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human-caused climate alterations to Arctic ecosystems have resulted in a constellation of impacts on the biological relationships within them, yet the consequences of these changes on the population dynamics of many species are poorly understood. Thus, an understanding of the drivers of variation in population performance is needed to inform the management and conservation of imperiled species. Here, we use a long-term dataset for the common eider, an Arctic-breeding sea duck, to examine the drivers of annual variation in nest survival, and evaluate the effects of variation in vital rates on population growth. Our chapter 2 results suggested that increased …

Avian Response To Post Wildland Fire Reseeding Treatments In Great Basin Shrubsteppe, Adam B. Brewerton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildfire is often considered a destructive force. However, we have learned that fire is a natural part of many ecosystems and can even be productive by recycling nutrients, and allowing for regrowth. A natural pattern of fire frequency allows for native plants and animals to recover from its destructiveness and capitalize on its benefits. Environmental changes, such as exotic invasive species, like cheatgrass, and livestock grazing, can make recovery less likely. Cheatgrass also promotes fire. As cheatgrass establishes, fires become more frequent and larger, making it hard or impossible for native plants to recover. Land managers often reseed to restore …

Genetic Diversity And Genetic Structuring At Multiple Spatial Scales Across The Range Of The Northern Leopard Frog, Rana Pipiens, Ryan P. O'Donnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genetic diversity is the raw material for evolution: evolution cannot happen without genetic diversity, and the ability of a population to respond to a changing environment depends directly on how diverse its genes are. Understanding the distribution of genetic diversity is important for many reasons, including predicting whether species will be able to adapt to climate change and predicting the spread of invasive species. Information about the distribution of genetic diversity across the range of the Northern Leopard Frog, a declining species, will not only help us to ensure that the species can continue to evolve in response to changing …

Using Relevance Vector Machines Approach For Prediction Of Total Suspended Solids And Turbidity To Sustain Water Quality And Wildlife In Mud Lake, Hussein Aly Batt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The main objective of the research is the development of Multivariate Relevant Vector Machine (MVRVM) to predict suspended fine sediment, water quality constituents, and provide an understanding for the practical problem of determining the amount of data required for the MVRVM. MVRVM is a statistical learning algorithm that is based on Bayes theory. It has been widely used to predict patterns in hydrological systems and other fields. This research represents the first known attempt to use a MVRVM approach to predict transport of very fine sediment and water quality constituents in a complex natural system.

The results demonstrate the ability …

Homogenization Of Large-Scale Movement Models In Ecology With Application To The Spread Of Chronic Wasting Disease In Mule Deer, Martha J. Garlick

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) that affects deer, elk, and moose. TSEs are prion diseases which include mad cow disease and scrapie in sheep and goats. The disease agent is a misshapen protein called a prion, which causes lesions in the brain, and to date, there is no cure. CWD is a slow-developing, fatal disease, which is rare in the free-ranging mule deer population of Utah. Infected deer shed prions into the environment through saliva, feces, and decaying carcasses. These prions remain infective in soils for many years and healthy deer may contract CWD by …

The Influence Of Geology And Other Environmental Factors On Stream Water Chemistry And Benthic Invertebrate Assemblages, John R. Olson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining if a stream has been degraded by human activities requires knowing what that stream’s natural water quality and freshwater species composition would likely be without any alteration. However stream natural conditions vary greatly from stream to stream, making predicting natural conditions difficult. To determine natural stream conditions, I developed models to predict natural stream water chemistry at individual streams across the western USA. Specifically, the models predict a stream’s electrical conductivity (a measure of the amount of solids dissolved in water), acid neutralization capacity, and concentrations of calcium, magnesium, sulfate, total phosphorus, and total nitrogen. These models predict chemistry …