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Assessing Plant Community Structure In The Upper Las Vegas Wash Conservation Transfer Area, Nevada: The Influence Of Biotic And Abiotic Variables, Amy A. Croft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Ecological communities are complex, the structure of which is composed of interactions between multiple community characteristics and the abiotic and biotic factors shaping them. Because of this complexity, ecological studies are generally limited in scope and size, often dissecting communities into their component parts to examine them piece by piece. While this might be the most practical method to study communities, this approach often neglects other characteristics that, with their inclusion, would provide a more complete picture of community ecology. The studies described in this dissertation were conducted in an effort to synthesize the complexity that is inherent in ecological …

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 …

Relationships Between Riparian Vegetation, Hydrology, Climate And Disturbance Across The Western United States, Nathaniel Hough-Snee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Flow regime, the magnitude, duration and timing of streamflow, controls the development of floodplain landforms on which riparian vegetation communities assemble. Streamflow scours and deposits sediment, structures floodplain soil moisture dynamics, and transports propagules. Flow regime interacts with environmental gradients like climate, land-use, and biomass-removing disturbance to shape riparian plant distributions across landscapes. These gradients select for groups of riparian plant species with traits that allow them to establish, grow, and reproduce on floodplains – riparian vegetation guilds. Here I ask, what governs the distributions of groups of similar riparian plant species across landscapes? To answer this question, I identify …

Spider Aggregate Glue Sequence Characterization And Expression, Kyle Berg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Orb-weaving spiders create a glue which is secreted onto the web to capture and retain insects. This glue is made from aggregate protein. Aggregate glue is sticky when wet and can stretch far when pulled at slow speeds, and pull back with a greater force if pulled at high speeds which helps it achieve its purpose as the adhesive that keeps insects in the web. These features also make it an attractive target for applications such as a surgical glue or underwater adhesive. Unfortunately, very little is known about the aggregate glue gene, and knowledge of the genetic sequence is …

To Dot Product Graphs And Beyond, Sean Bailey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We will introduce three new vector representations of graphs. These representations are based on relationships between the vectors that are used. Specifically, we will examine scenarios where we ignore specific relationships, where we consider if information is missing, and where we look for when the information in common is not of a specified amount.

Quantum Mechanical Studies Of Charge Assisted Hydrogen And Halogen Bonds, Binod Nepal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Like cement bridges one brick to another, noncovalent forces also bridge two or more molecules together to form a molecular crystal or molecular cluster. Although weaker than the covalent bond, the existence of noncovalent forces can be seen everywhere from liquid water to construction of complex biomolecules like DNA, RNA, proteins etc. An introduction of suitable charge; positive or negative, on the binding units can increase the strength of noncovalent interaction by several orders of magnitude. The primary aim of this dissertation is to explore some fundamental properties of such charge assisted noncovalent interactions which will be helpful for the …

Soil Nutrient Cycling And Water Use In Response To Orchard Floor Management In Stone-Fruit Orchards In The Intermountain West, Catherine Mae Culumber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An organic peach orchard trial evaluated the effectiveness of different organic management approaches to enhance soil quality and conserve water without compromise to fruit tree growth and fertility. Two tree-row treatments: ‘straw mulch’ (Triticum aestivum L.) and ‘living mulch’ (Lobularia maritima (L.) Desv.) were tested in combination with two alleyway groundcovers: ‘grass’ (Festuca rubra L. with Lolium perenne L.) and a legume, ‘Birdsfoot trefoil’ (Lotus corniculatus L.). The novel treatments were compared with tillage and weed fabric tree-rows with grass alleyways. After mowing, cuttings from the trefoil alleyway were deposited into tree-rows, which provided additional N …

Identifying And Reducing Risk Of The Female Athlete Triad In Division I Athletes, Jennifer Day

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Physically active females, or female athletes, are at risk for the condition known as the female athlete triad (Triad). The Triad is made up of three components that are distinctly separate, but intertwined: consuming inadequate energy for how much they are exercising, poor bone health, and problems with their menstrual periods. When female athletes don’t consume enough energy for how much they exercise, there can be hormonal imbalances, causing the body to conserve energy from some important functions including menstruation, and increased bone turnover resulting in a higher risk of stress fractures and early osteoporosis. Female athletes at risk for …

Sagebrush Ecology Of Parker Mountain, Utah, Nathan E. Dulfon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

On Parker Mountain located in south central Utah, management actions such as controlling mountain big sagebrush (Artemisia tridentata Nutt. subsp. vaseyana), with mechanical and chemical treatments can increase forage for livestock and benefit wildlife such as greater sage-grouse (Centrocercus urophasianus). Tebuthiuron treatments were applied on Parker Mountain from 2000-2012 with assistance from the Utah School and Institutional Trust Lands Administration, the Utah Department of Food and Agriculture, and the Natural Resources Conservation Service. Treatments applied to mountain big sagebrush on Parker Mountain provide an important opportunity to evaluate the value of mountain big sagebrush treatments in …

Rhizosphere Interactions Between Copper Oxide Nanoparticles And Wheat Root Exudates In A Sand Matrix; Influences On Bioavailability And Uptake, Paul Mcmanus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Copper oxide nanoparticles (CuO NPs) are extremely small particles (less than 1 nm in one or more dimension, or one billionth (10^-9) of a meter) used in a diverse range of industries. They have been shown to travel through water systems, and like pharmaceuticals, can end up in wastewater treatment plants and then be land applied as biosolids, where crops are grown for animal consumption, potentially leading to food chain accumulation.

Cu is an essential micronutrient for plants, but is phytotoxic at higher concentrations. CuO NPs present an increasingly real environmental threat to agriculture in soils treated with …

Stable Isotopes And The Ecology And Physiology Of Reptiles, Andrew M. Durso

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When animals don’t have enough food, they have to “choose” between “spending” their limited energy on themselves or on their offspring. Biologists think that reptiles can make this choice quickly in response to different environments. But, it can be hard to study these choices because it is hard to convert between, for example, the number of eggs laid and the speed of healing a wound. By using stable isotope chemistry, we can collect more detailed and comparable information about how lizards and other animals spend their limited resources than with any other method. For example, lizards in the wild have …

Revegetation Of Bulrushes Bolboschoenus Maritimus, Schoenoplectus Acutus, And S. Americanus In Great Salt Lake Wetlands: Seed Biology And Influence Of Environmental Factors On Rhizomes, James Marty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A primary goal of ecological restoration is to establish desirable plant species. This goal is particularly important following the removal of invasive plants. Understanding biological characteristics of plant species important to revegetation is crucial to plant establishment. In the globally important Great Salt Lake (GSL) wetlands, native habitat-forming bulrushes Bolboschoenus maritimus, Schoenoplectus acutus, and S. americanus are frequently displaced by the invasive grass Phragmites australis. Bulrush seeds require very specific germination conditions and are also dormant, therefore they do not germinate consistently even when exposed to appropriate germination conditions. Additionally, wetland environments are often associated with water …

Agricultural Nitrogen Management Affects Microbial Communities, Enzyme Activities, And Functional Genes For Nitrification And Nitrogen Mineralization, Yang Ouyang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Improved understanding of nitrogen cycling in agriculture is essential for increasing fertilizer use efficiency and sustainable food production. The availability and mobility of nitrogen are largely determined by the processes of nitrogen mineralization and nitrification. Nitrification is mediated by ammonia oxidizing bacteria, ammonia oxidizing archaea, and nitrite oxidizing bacteria. Our understanding of the controls on the relative activity of these nitrifying organisms in soil is limited. A wide variety of soil microorganisms produce enzymes that mineralize nitrogen from organic matter, but we have limited knowledge about links between enzyme activity and the microbes that work in soil. The main objective …

Salt Tolerance Of Forage Kochia, Gardner's Saltbush, And Halogeton: Studies In Hydroponic Culture, Joseph Sagers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Halogeton (Halogeton glomeratus) is a halophytic, invasive species that displaces Gardner’s saltbush (Atriplex gardneri) on saline rangelands. Forage kochia (Bassia prostrata) is a potential species to rehabilitate these ecosystems. This study compared the salinity tolerance of these species and tall wheatgrass (Thinopyrum ponticum) and alfalfa (Medicago sativa). Plants were evaluated for 28 days in hydroponics where they were maintained at 0, 150, 200, 300, 400, 600, and 800 mM NaCl. Shoot growth and ion accumulation were determined. Alfalfa and tall wheatgrass were severely affected by salt with both species’ shoot …

Synthetic Spider Silk Sustainability Verification By Techno-Economic And Life Cycle Analysis, Alan Edlund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Major ampullate spider silk represents a promising biomaterial with diverse commercial potential ranging from textiles to medical devices due to the excellent physical and thermal properties from the protein structure. Recent advancements in synthetic biology have facilitated the development of recombinant spider silk proteins from Escherichia coli (E. coli), alfalfa, and goats. This study specifically investigates the economic feasibility and environmental impact of synthetic spider silk manufacturing. Pilot scale data was used to validate an engineering process model that includes all of the required sub-processing steps for synthetic fiber manufacture: production, harvesting, purification, drying, and spinning. Modeling was constructed modularly …

The Effects Of Familism And Sibling Relationships On Mexican-Origin Adolescents' Intentions For Alcohol, Tobacco, And Other Drug Use, Molly Mechammil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The aim of this study was to investigate whether and how sibling relationships and family values intersect to influence Mexican origin youth’s intentions to use substances. Previous research with European-American families has indicated that the nature and quality of sibling relationships in particular plays a large role in whether or not youth will engage in substance use behaviors. In addition, high levels of family and cultural values have also been found to be strong protective factors for substance use in Latino youth. A better understanding of the relation between family values and sibling relationship processes is important in order to …

Discharge-Suspended Sediment Relations: Near-Channel Environment Controls Shape And Steepness, Land Use Controls Median And Low Flow Conditions, Angus A. Vaughan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Erosion, transport and deposition of fine sediment (clay, silt and fine sand) influence the form and function of river systems. Excess suspended sediment degrades stream ecosystems and is implicated as a leading cause of water quality and aquatic life impairment. Therefore, understanding the factors that control fine sediment transport patterns is an interesting topic for basic science and one that has important management and policy implications.

In this study, we sought to understand how attributes of the landscape and channel network might control the shape, steepness and vertical offset of the relationship between river discharge and suspended sediment. Watershed and …

Hybridization, Population Genetic Structure And Gene Expression In The Genus Boechera, Martin Peter Schilling

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When we look at life on earth, we can see a lot of different life forms, but we still do not fully understand how these different life forms came to be and at which points in time these life forms began to be different enough from each other so we could call them by different names, or species. Some groups of species on earth, especially plants, seem to reproduce with each other, even though they are already very different from each other so that we call them different species. This process is called hybridization, and it can stir up the …

The Utah Forest Dynamics Plot: Long-Term Ecological Monitoring And Theoretical Ecology In A High-Elevation Subalpine Environment, Tucker J. Furniss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a …

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 …

Family And Consumer Sciences Teacher Needs Assessment Of A Stem-Enhanced Food And Nutrition Sciences Curriculum, Cathy A. Merrill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Career and Technical Education (CTE) has long taught abstract science, technology, engineering, and mathematics (STEM) concepts in contextualized settings. In 2014, a new CTE Food and Nutrition Sciences curriculum was written by a pilot group of CTE family and consumer sciences teachers, enhancing the STEM education teaching opportunities available in a food and nutrition course. This study is a teacher needs assessment of the implementation of the new STEM-enhanced curriculum.

The curriculum objectives were measured for perceived importance and self-perceived ability to teach by the teachers. Curriculum feedback, educational background and general demographics were also gathered. The curriculum objectives data …

Influence Of Disturbance On Greater Sage-Grouse Habitat Selection In Southern Utah, Erica P. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern that occupies sagebrush-dominated (Artemisia spp.) landscapes across the western United States and southern Canada. The U. S. Fish and Wildlife Service (USFWS) reviewed the status of the sage-grouse in September 2015 and determined that it did not warrant protection under the Endangered Species Act due to collaborative efforts between numerous public and private stakeholders. However, this decision hinged on federal and state commitments to continue science-based management of sagebrush habitats. As human development increases across the west, there is an increasing need for understanding …

Computational Chemistry Of Non-Covalent Interaction And Its Application In Chemical Catalysis, Vincent De Paul Nzuwah Nziko

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Known to be weaker than conventional covalent bonds, non-covalent bonds, especially hydrogen bond, has shown to be of great importance in molecular structures such as DNA, RNA, proteins and other organic frameworks. In this dissertation, we looked at non-covalent interactions other than the hydrogen bond. Replacement of the bridging hydrogen atom in a typical hydrogen bond by other atoms such a halogen, chalcogen and tetrel lead to the formation of interactions which are comparable in strength to the hydrogen bond. Unlike the hydrogen bond which arises mainly from electrostatics, these unconventional interactions mostly result from induction. Besides studying the fundamentals …

An Economic Analysis Of Factors Affecting Pre-Weaned Dairy Calf Growth And Profit Optimization In Dairy Calf Operations, Vincent T. Hess

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was an extension of a study submitted in April 2014 by Sheldon D. Holt entitled “Ambient Temperature, Calf Intakes, and Weight Gains on Preweaned Dairy Calves”.

A major component in a profitable dairy operation is the raising of female calves as replacement heifers; but since no direct income is generated by calf raising alone, it is often overlooked as a potential profit area on a dairy farm. Calf management practices that ultimately impact milk productivity and reproductive performance during a heifer’s lifetime begin at birth. This study examines the effect of calf starter intake on calf growth, measuring …

An Analysis Of The Feasibility Of Anaerobic Digestion On Small-Scale Dairies In Utah, Steven Chans Lund

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With an ever increasing concern for the environment, different methods of managing organic waste on dairy farms have been explored and analyzed. Anaerobic digestion has long been a popular method of managing organic waste. Its popularity stems from the potential to decrease greenhouse gases, improve air quality and provide a source of additional revenue for the farm. Problems with implementing anaerobic digestion arise from high failure rates, high start-up costs and continuous maintenance and equipment replacement.

Subsidies for the initial investment and improved technology have increased the possibility of large-scale dairy farms to adopt anaerobic digestion. Due to economies of …

Accumulation And Release Of Trace Inorganic Contaminants From Biofilm Matrices Produced And Challenged Under Drinking Water Distribution System Conditions, William W. Kent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Drinking water distribution systems (DWDS) are used to transport drinking water from the place of treatment to your home. DWDS are made of many types of pipe materials and have the potential to accumulate materials such as iron and manganese oxides and biofilms that serve as reservoirs for toxic trace inorganic contaminants (TICs) such as thallium, arsenic, and lead. These materials can be stable, but changes in water quality or a physical disturbance such as road construction or water use changes may result in a TIC release, causing water quality degradation. This study used glass columns filled with glass beads …

Structural And Biochemical Characterization Of The Frequency-Interacting Rna Helicase Frh, Jacqueline M. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cells function through a variety of regulatory pathways intricately communicating with one another. These pathways ensure that cellular functions happen at the appropriate times and keep the natural balance within the cell. When pathways do not communicate appropriately, this can lead to disease states and cell death. Two such connected pathways in Neurospora crassa involve the regulation of RNA levels and the circadian rhythms essential for these cells to maintain homeostasis. These pathways are connected by a unique helicase called the Frequency-interacting RNA Helicase (FRH), named for its discovery with the frequency protein involved in the circadian oscillation of the …

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 …

Perceived Alzheimer's Disease Threat As A Predictor Of Behavior Change To Lower Disease Risk: The Gray Matters Study, Christine Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alzheimer’s disease is a growing public health concern with an estimated five million Americans currently afflicted. That number is projected to triple by 2050 as the baby boomer generation approaches age 65, the most common age where people begin to show symptoms of cognitive decline stemming from changes in the brain related to Alzheimer’s. Since there is currently no cure or preventive pharmacological treatment, AD prevention research is now recognized as an important enterprise. Modifiable lifestyle factors that can reduce AD risk or delay its onset have been identified as reasonable targets for behavioral intervention, including increased physical activity, healthier …