Life Sciences Commons^™

Nitrogen Cycling In The Rhizosphere Of Cheatgrass And Crested Wheatgrass: Contributions Of Root Exudates And Senescence, Kendalynn A. Morris

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cheatgrass is an invasive weed that has come to dominate large areas of the western United States. Once an ecosystem has been converted to a cheatgrass monoculture, it is extremely difficult to restore native vegetation. Cheatgrass negatively impacts wildlife and increases wildfire frequency and intensity. Understanding how cheatgrass so effectively invades western ecosystems is essential to turning the tide of invasion. One possible key to cheatgrass’ success is alteration of soil nutrient cycling. The goal of this study is to explore how nitrogen (N) may accumulate in cheatgrass soils via redistribution of N within soil N pools. To accomplish this …

Macroinvertebrate-Driven Nutrient Recycling In Four Large Rivers, Matt A. Schroer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cycling of nutrients is a fundamental process in streams and rivers, and scientists are increasingly recognizing the importance of animal communities to nutrient dynamics in these ecosystems. Despite growing evidence that animal excretion (i.e. urine) can supply limiting nutrients to primary producers in small streams, the importance of excretion is uncertain in large rivers. Accordingly, I used three estimation approaches based on past and new excretion rate data to determine nitrogen (N) and phosphorus (P) excretion inputs from insect communities in four large rivers (discharge > 10 cubic meters per second) in North America, and I compared these rates to …

Estimating Baseline Population Parameters Of Urban And Wildland Black Bear Populations Using A Dna-Based Capture-Mark-Recapture Approach In Mono County, California, Jonathan L. Fusaro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Prior to European settlement, black bear (Ursus americanus) were far less abundant in the state of California. Estimates from statewide harvest data indicate the California black bear population has tripled in the last 3 decades. Bears inhabit areas they formally never occurred (e.g., urban environments) and populations that were at historically low densities are now at high densities. Though harvest data are useful and widely used as an index for black bear population size and population demographics statewide, it lacks the ability to produce precise estimates of abundance and density at local scales or account for the numerous …

Systematics And Behavioral Evolution Of Spider Wasps (Hymenoptera: Pompilidae), Cecilia Waichert Monteiro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider wasps form a diverse and widespread group of stinging wasps. Although all Pompilidae have similar life history characteristics, there is considerable variation in nesting behavior modes and, thus, this family could be useful for learning about the evolution of nesting behavior in insects. The nesting behavior of many species is well known, the family is monophyletic and easily recognized, and certain species have some degree of pre-sociality, i.e., communal nesting. All these factors suggest that the Pompilidae are an important model group for understanding mechanisms and patterns of behavioral evolution.

Pompilidae, however, are rarely studied and their research potential …

Characterization Of Lactose Esters For Their Antimicrobial And Emulsification Properties, Guneev Sandhu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sucrose esters have an established use in food industry as emulsifiers. Two novel lactose esters (lactose monodecanoate and lactose monomyristate) were synthesized and studied for their antimicrobial and emulsification properties. Lactose is a byproduct in cheese production and is an inexpensive carbohydrate source.

The antimicrobial activity of lactose monodecanoate (LMD) and lactose monomyristate (LMM) was tested against the growth of seven different bacteria. Both esters, when dissolved in dimethoxy sulfoxide (DMSO), proved bactericidal against Bacillus cereus, Mycobacteria KMS and Streptococcus suis. LMM/DMSO was bactericidal against B. cereus at concentrations between 1 and 3 mg/ml. LMM/DMSO was bactericidal against …

Stability Of W1/O/W2 Double Emulsion Made With Milk Fat And A Simplified Make Procedure And Its Use In Reduced-Fat Cheese, Daniel Bradley Clayton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As overweight and obesity numbers continue to climb around the world, consumers continue to search for reduced-fat alternatives to foods they often consume. Given that cheese is naturally high in fat, this is one food that is often targeted for fat reduction. However, as fat plays an important functional role in the texture of cheese by breaking up the continuous protein matrix, reduced-fat products tend to be very chewy and rubbery compared to their full-fat counterparts.

My study aimed at producing a reduced-fat cheese with improved texture compared to other reduced-fat cheese products by incorporating a double emulsion into the …

Distribution And Drivers Of A Widespread, Invasive Wetland Grass, Phragmites Australis, In Great Salt Lake Wetlands, Arin Lexine Long

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native invasive plant species can often have negative effects on native ecosystems, such as altered nutrient cycling, decreased habitat for wildlife, and outcompeting native plants. Around the Great Salt Lake (GSL), Utah, the invasive wetland grass Phragmites australis has become abundant in wetlands around the lake. Phragmites is replacing many native wetland plants provide important waterfowl habitat around the GSL. For successful management of Phragmites in GSL wetlands, it is important to know the current distribution of Phragmites, as well as areas that might be vulnerable to future invasion by Phragmites. To do this, we used multispectral aerial …

Use Of A Net Rate Of Energy Intake Model To Examine Differences In Juvenile Steelhead (Oncorhynchus Mykiss) Densities And The Energetic Implications Of Restoration, C. Eric Wall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bonneville Power Administration (BPA) Fish and Wildlife Program mitigates for impacts of hydroelectric dams on ESA-listed salmon and steelhead populations in the Columbia River Basin (CRB). Considering the sizable investments in mitigation and the diversity of stream habitats within the CRB, there has been a pointed effort to develop and identify meaningful metrics relating to fish populations and trends in their habitat across the CRB. The Integrated Status and Effectiveness Monitoring Program (ISEMP) was developed in 2003 specifically for this purpose, and is tasked with developing and testing strategies for determining the status and trend of salmonid populations and …

Deficit Irrigation Of Kentucky Bluegrass For Intermountain West Urban Landscapes, Hang T. T. Duong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to end users irrigating with excess water, water conservation of turfgrass can make a large impact in urban water conservation by reducing water applied while still maintaining visual appearance. This study was conducted to determine if Kentucky bluegrass (Poapratensis L.) can be deficit irrigated to maintain minimum acceptable appearance while conserving water. The study investigated water stress in terms of stomatal conductance, chlorophyll index, leaf temperature and predawn leaf water potential at the point of water stress, or where visual quality no longer meets expectations during dry down conditions. Water use was measured over well established Kentucky …

Yield And Quality Of First-Year Corn Silage Following Alfalfa Stand Termination As Affected By Tillage, Herbicide, And Nitrogen Fertilizer, Jason Daniel Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Glyphosate-containing herbicides such as Roundup® are a common and highly effective method to terminate alfalfa stands. With the development of glyphosate-resistant (Roundup Ready®) alfalfa, this tool is no longer an option. The purpose of this research was to determine the optimal termination methods to use when rotating from glyphosate-resistant alfalfa into silage corn. Studies were conducted in 2012 and 2013 in Cache Junction and Cornish, Utah using five different combinations of tillage type and timing (fall conventional till, spring conventional till, fall strip-till, spring strip-till, and no-till), four 2,4-D plus dicamba herbicide timings (fall, spring, in-crop, and a control), and …

Influence Of Mountain Pine Beetle On Fuels, Foliar Fuel Moisture Content, And Litter And Volatile Terpenes In Whitebark Pine, Chelsea Toone

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain pine beetle (Dendroctonus ponderosae Hopkins) has caused extensive tree mortality in whitebark pine (Pinus albicaulis Engelm) forests. Previous studies conducted in various conifer forests have shown that fine surface fuels are significantly altered during a bark beetle outbreak. Bark beetle activity in conifer stands has also been shown to alter foliar fuel moisture content and chemistry over the course of the bark beetle rotation.

The objective of this study was to evaluate changes to fine surface fuels, foliar fuel moisture and chemistry and litter chemistry in and under whitebark pine trees infested by mountain pine beetle. Fuels …

Winter Waterbird Ecology On The Great Salt Lake, Utah, And Interactions With Commercial Harvest Of Brine Shrimp Cysts, Anthony J. Roberts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Interactions among commercial fisheries and birds have been studied in open ocean ecosystems and at aquaculture facilities. On the Great Salt Lake (GSL), Utah, USA, a commercial harvest of brine shrimp (Artemia franciscana) eggs (i.e. cysts) occurs annually during fall and winter. Coinciding with commercial harvest is the use of the GSL by millions of waterbirds which has the potential to result in conflict among industry and birds. The objectives of my research were to examine fall and winter ecology of birds using the GSL and interactions with the brine shrimp cyst harvest. I examined the influence of temperature and …

Determination Of The Expression Patterns Of Bovine Non-Classical Major Histocompatibility Complex (Mhc) Class I Proteins, Parveen Parasar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This project was funded by the United States of Department of Agriculture (USDA), which funds research aimed at improving production and animal health. The aim of this study was to advance knowledge of maternal immune tolerance to the fetus and mechanisms bovine non-classical MHC class I proteins employ to interact with immune cells and render them inert towards the fetus.

A fetus is a tissue graft inside the mother’s uterus yet must be accepted by the mother to maintain a successful pregnancy. Reproductive insufficiency and pregnancy failure are major causes of production loss in cattle, especially in cloned animals. Knowledge …

Constraints On Patterns Of Abundance And Aggregation In Biological Systems, Kenneth J. Locey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the mechanisms that structure biological systems is a primary goal of biology. My research shows that the biological structure is constrained in important ways by general variables such as the number of base pairs in a genome and the number of individuals and species in a community. I used a combination of macroecology, bioinformatics, statistics, mathematics, and advanced computing to pursue my research and published several peer-reviewed scientific manuscripts and open-source software as a result.

I was funded through a combination of fellowships and scholarships awarded by the Utah State University School of Graduate Studies, College of Science, and …

Optimizing Systems For Cold-Climate Strawberry Production, Tiffany L. Maughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Producing fruits and vegetables in the Intermountain West can be challenging due a short growing season, extreme temperatures, and limited availability of irrigation water. This is particularly true of strawberries, where commercial production is limited due to late fall and early spring frosts that shorten the growing season. With the increasing demand for local produce as urban populations grow and as consumer buying habits change, growers are looking for ways to overcome these climatic challenges. High tunnels are one option growers can use. High tunnels are similar to greenhouses, but less expensive to construct and to maintain. Another way to …

Characterization Of The Hydrogen Peroxide Stress Responses Of Bifidobacterium Longum And Bifidobacterium Animalis Subsp. Lactis, Taylor S. Oberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Probiotics are living organisms which exert a beneficial health effect when consumed in sufficient numbers. Consumer interest in probiotics has increased dramatically in recent years prompting an increase in production and development of functional foods. One major problem is the decreased viability of probiotic bacteria during functional food production and storage and subsequent digestion due to environmental stresses. The most common probiotic strains belong to the genus Lactobacillus or Bifidobacterium. Due to the anaerobic nature of these bacteria, they lack the required defense mechanisms for oxidative stress inherent in aerobic microorganisms. This study examined the oxidative stress responses of …

Effect Of Predator Removal On Greater Sage-Grouse (Centrocercus Urophasianus) Ecology In The Bighorn Basin Conservation Area Of Wyoming, Elizabeth Kari Orning

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The decline of greater sage-grouse distribution and population densities across western North America has led conservation, research, and management objectives to focus efforts on understanding sage-grouse populations across their range. The purpose of this study was to gain a better understanding of direct and indirect predation effects on hen survival and nest success of sage-grouse. The project was conducted in Hot Springs and Park Counties in the Bighorn Basin of Wyoming. The study had three main objectives: 1) obtain and quantify the types and impacts of predators on sage-grouse hen survival and nest success, 2) compare the effect predator removals …

Climate Change And Plant Demography In The Sagebrush Steppe, Aldo Compagnoni

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We used demographic methods to address one of the main challenges facing ecological science: forecasting the effect of climate change on plant communities. Ecological forecasts will be crucial to inform long-term planning in wildland management and demographic methods are ideal to quantify changes in plant abundance. We carried out our research in the sagebrush steppe, one of the most extensive plant ecosystems of Western North America. Our research intended to inform ecological forecasts on an exotic invader, cheatgrass (Bromus tectorum). Moreover, we investigated the general question asking: to what degree competition among plants influences the outcome of ecological …

Presence And Function Of Tetrodotoxin In Terrestrial Vertebrates And Invertebrates, Amber N. Stokes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tetrodotoxin (TTX) is a potent neurotoxin found in a variety of species. This toxin has long been of concern to human health as it is found in puffer fish, which are a delicacy in Japan. Since the distribution of this toxin is so great, there are many questions regarding the evolution and ecology of organisms that have TTX. My research has focused on further investigating three topics with this research: production, predation, and identification of novel TTX bearing taxa. In order to perform this research I first refined a Competitive Inhibition Enzymatic Immunoassay methodology to quantify levels of TTX in …

The Ecology And Genetics Of Schoenoplectus Maritimus, An Important Emergent Macrophyte, Across Diverse Hydrologic Conditions—Implications For Restoration, Amanda Clare Sweetman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wetlands in the Intermountain West are typically dominated by large monotypic stands of emergent wetland plants, are highly productive, and support millions of migratory birds as important stops along the Pacific Flyway. In systems with low species diversity, such as these, diversity within a species (intraspecific diversity) can play an important role in population fitness and ecosystem functioning and can impact restoration success. Our research was designed to inform future restoration and management activities by studying the pattern of diversity within and among natural plant populations, and by studying how hydrology and plant materials used in restoration (source and diversity …

Utilizing Remote Sensing And Geospatial Techniques To Determine Detection Probabilities Of Large Mammals, Patricia A. Terletzky-Gese

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whether a species is rare and requires protection or is overabundant and needs control, an accurate estimate of population size is essential for the development of conservation plans and management goals. Wildlife science has traditionally relied on human observers in airplanes, helicopter, or ground vehicles to count the number of individuals seen during wildlife surveys. However, these traditional surveys of wildlife require significant resources, are difficult to conduct quickly and safely over remote and/or extensive locations, are disruptive to the studied species, and are prone to significant error due to unobserved or missed animals and multiple counts of single animals. …

Common Raven Density And Greater Sage-Grouse Nesting Success In Southern Wyoming: Potential Conservation And Management Implications, Jonathan B. Dinkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Declines in the distribution and abundance of greater sage-grouse (Centrocercus urophasianus; hereafter "sage-grouse") in western North America over the past century have been severe. The goal of my research was to increase the understanding of factors influencing where sage-grouse hens placed their nests, how common ravens (Corvus corax: hereafter "raven") impacted sage-grouse nest success, and whether high raptor densities negatively impacted hen survival of sage-grouse. I compared raven and raptor densities at sage-grouse nest and brood locations to available habitat. I also assessed how sage-grouse positioned their nests and broods relative to proximity to man-made structures, …

Modeling Habitat Use Of A Fringe Greater Sage-Grouse Population At Multiple Spatial Scales, Anya Cheyenne Burnett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; hereafter sage-grouse) are a prominent bird species of sagebrush-dominated landscapes across the western United States. Over the past 15 years, sage-grouse have gained international attention due to decreasing population trends despite management efforts. In 2010 the U.S. Fish and Wildlife Service designated this species as warranted for listing under the Endangered Species Act, but the listing was precluded by other species at higher conservation risk. Habitat loss, degradation, and fragmentation have been implicated as primary sources of declines in sage-grouse distribution and abundance. The Bald Hills population in southwestern Utah occupies an area with …

Selected Neuropharmacology Of Resurgence, Adam D. Pyszczynski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The reemergence of problem behavior (i.e., relapse) is a key concern in most behavioral interventions. Resurgence refers to the reappearance of a previously rewarded behavior when reward for an alternative behavior is also discontinued. It is especially relevant to the reappearance of problem behavior because many behavioral interventions discontinue reward for aberrant behavior while simultaneously rewarding an appropriate response.

Understanding the underlying neuropharmacology of behavioral phenomena such as resurgence is important because it helps elucidate the neural processes at the root of such behavior, and also has implications for pharmacotherapies. Existing information about the neuropharmacology of resurgence is scarce, but …

Assessment Of Consumer Motivations To Attend Farmers' Markets, Their Preferences, And Their Willingness To Pay For Differentiated Fresh Produce: Three Essays, Jean Dominique Gumirakiza

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this public abstract is to present research objectives, societal benefits, and costs associated with this dissertation. This dissertation is one the outcomes of a three-year $155,450.86 project whose number is UTA01008. Kynda Curtis, Associate Professor, Department of Applied Economics proposed the project to assess consumer demand and purchase motivations for differentiated produce across direct marketing outlets. In general, this dissertation seeks to analyze consumer primary motivations for attending farmers’ markets, their preferences, and their willingness to pay for differentiated fresh produce. To accomplish this task, we develop three essays.

Specific objectives for the first essay are to …

Assessing The Importance Of Sequencing Laboratory Welding Practicums, Malcolm Riley Rose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to determine if having fewer operator-controlled variables during welding will improve secondary students' ability to meet weld quality standards for an AWS 1F test. Two different welding processes, Gas Metal Arc Welding and Shielded Metal Arc welding, were used in the research. The population of this study (N = 71), participants were randomly assigned into one of four treatment groups. The study was conducted over six class periods. Participants completed a welding pretest, taught safety procedures followed by welding instruction of both GMAW and SMAW process. Practice sessions were given for each welding …

Greater Sage-Grouse Habitat Selection And Use Patterns In Response To Vegetation Management Practices In Northwestern Utah, Stephanie E. Graham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are a sagebrush obligate species and an indicator of sagebrush (Artemisia spp.) habitat quality. Sage-grouse populations have declined across western North America. Fragmentation of landscapes and habitat loss have been identified as factors that negatively impact sage-grouse populations. Wildfires can increase the distribution of invasive plants and contribute to fragmentation and habitat loss across sagebrush ecosystems. Greenstripping has been identified as a technique to reduce the threat of wildfire and subsequent spread of invasive species. Forage kochia (Bassia prostrata) is a semi-shrub that contains a high moisture content year-round, high …

Apoptotic And Epigenetic Induction Of Embryo Failure Following Somatic Cell Nuclear Transfer, Aaron Patrick Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cloning of domestic species has tremendous potential, as the technology can be used in selective breeding, conservation, and the production of transgenic animals. The technique of cloning involves the transplant of DNA from a cell to a recipient gamete. Following transfer to a surrogate, the cloned embryo may successfully complete development to a live offspring. Despite intensive research, the success rate of cloning remains prohibitively low, and the potential benefits of cloning have not yet been realized. Embryos produced from cloning suffer from high rates of embryo degradation, implantation failure, and abortion. The goal of this dissertation research project …

Effects Of Integrating Mathematical Concepts Into An Animal Science Curriculum, Andrea Rae Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nationwide, mathematical scores have been a topic of concern among elementary and secondary educators for many years. Teaching contextualized math has been found to be effective and includes providing a direct application to real-life scenarios rather than teaching linear equations and algebraic principles outside of their application.

A study was conducted measuring the effects of integrating mathematical skills in an animal science curriculum. All students were taught a unit of instruction about animal nutrition and feeding. The control group received a typical nutrition unit and the treatment group received the same unit of instruction with the addition of mathematical skill …

Self-Limitation As An Explanation For Species' Relative Abundances And The Long-Term Persistence Of Rare Species, Glenda Marie Yenni

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological theories often hinge on species interactions, or how the species in an area "see" other species with whom they have to share food and space. Despite the contributions theoretical coexistence models have made to our understanding of species coexistence, it can still be difficult to match these theories with data from real communities. For example, we know of many species that are very rare where they occur. Theory predicts that these species should quickly go extinct, but they do not. I use simulations and real data to show that rare species are rare because they are more self-limiting. Self-limitation …