Digital Commons Network^™

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 …

Cyber-Physical Systems Enabled By Unmanned Aerial System-Based Personal Remote Sensing: Data Mission Quality-Centric Design Architectures, Calvin Coopmans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the coming 20 years, unmanned aerial data collection will be of great importance to many sectors of civilian life. Of these systems, Personal Remote Sensing (PRS) Small Unmanned Aerial Systems (sUASs), or “data drones,” will need special attention due to their low cost and high value for farming, scientific, and search-and-rescue uses, among countless others. Cyber-physical systems (large-scale, pervasive automated systems that tightly couple sensing and actuation through technology and the environment) can use sUASs as sensors and actuators, leading to even greater possibilities for benefit from sUASs. However, this nascent robotic technology of small unmanned aerial systems (sUASs) …

The Optimal Cow Size For Intermountain Cow-Calf Operations: The Impact Of Public Grazing Fees On The Optimal Cow Size, Jesse Russell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cattle industry is very competitive which is forcing cow-calf producers to strive for efficiency. Research has shown that as a cows mature weight increases, feed efficiency decreases, as well as reproductive efficiency and other production factors. The purpose of this paper is to (1) identify the economically optimum cow size when charging for grazing public lands on a true Animal Unit Equivalent (AUE) basis and (2) determine if the current practice of charging on a per head basis for grazing public lands has an effect on the optimal cow size.

To simplify the complexity of this problem, three different …

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 …

Are Experimentally Derived Estimates Of Thermal Tolerance Useful In Interpreting Species Distribution Models, Iva Sokolovska

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Species distribution models are frequently used in ecology to predict the spatial and temporal occurrence of organisms. Direct interpretation of these models assumes that the relationships between the organisms and their environment are manifestations of causal mechanisms. However, in general, the mechanisms producing these associations have not been experimentally validated, which questions our confidence in their interpretation and application. Temperature is one of the most important factors influencing the fitness and distribution of aquatic organisms, and studying the thermal physiology of aquatic invertebrates could provide a useful approach for validating predictions of the species distribution models.

Experimental thermal tolerance studies, …

Adolescent Self-Described Volume Of Texting: Discovering Relationships With Psychosocial Development And Interpersonal Relationships, Tessa Cutler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Researchers explored the relationship among adolescent self-reported amounts of texting and self-esteem, self-construal, autonomy, and attachment. Data were collected from a high school in an urban area in the Mountain West. Participants included 180 students (53% female). Participants were asked to self-describe their volume of texting as high, medium, or low. Participants were also asked to complete the following scales: Rosenberg Self-Esteem Scale, the Self-Construal Scale, the Case Inventory, The Adolescent Autonomy Questionnaire, and The Modified Inventory of Parent and Peer Attachment.

It is suggested that text messaging is more strongly related to self-esteem when texting is placed as the …

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 …

Biopsychosocial Variables Predict Compensation And Medical Costs Of Radiofrequency Neurotomy In Utah Workers' Compensation Patients, Amie L. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Back pain is one of the most expensive medical conditions to treat. There has been a great deal of research showing that back pain surgery is expensive, but less is known about the costs of less-invasive spine procedures such as radiofrequency neurotomy. Radiofrequency neurotomy is used to treat facet joint pain and typically offers temporary pain relief by coagulating the affected nerve with radiofrequency waves to block pain messages from reaching the brain. This study aimed to document the costs of radiofrequency neurotomy in a group of participants who received the procedure through the Workers’ Compensation Fund of Utah (WCFU). …

Optimization Of Wastewater Microalgae Pretreatment For Acetone, Butanol, And Ethanol Fermentation, Yessica A. Castro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Acetone-butanol-ethanol (ABE) fermentation from wastewater microalgae by Clostridium saccharoperbutylacetonicum N1-4 is a novel bioprocess that utilizes waste substrate to generate valuable solvents. Butanol, the most abundant product resulting from ABE fermentation, is an environmentally safe and high performing fuel that can be utilized as a drop-in-fuel; however, high operational costs and low ABE yield present challenge in scale-up of the process. The utilization of algae as a substrate requires pretreatment prior to fermentation to increase the bioavailability of the algal fermentable sugars and to improve the conditions of the pre-fermentation medium. The purpose of this thesis was to optimize wastewater …

Impact Of Beaver Ponds On Stream Temperature And On Solar Radiation Penetration In Water, Camilla J. Snow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Beaver dams alter streams characteristics in a way that promotes the diversity of aquatic species and provides a wide distribution of temperatures within beaver ponds. In order to quantify the spatial distribution of these temperatures, a process-based temperature model was developed for a beaver pond in Northern Utah. This model provided insight into the processes and characteristics that are driving these temperatures. Solar radiation is one of these processes that is often the primary driver of stream temperature. There is a need to develop methods to measure the fate of solar radiation within the water to better represent solar radiation …

Climate Forcings On Groundwater Variations In Utah And The Great Basin, Kirsti A. Hakala

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Groundwater levels over northern Utah have undergone a declining trend since the 1960’s. This trend has made apparent the need to understand the relationship between climate and groundwater resources. Such necessary information is already in dire need in places such as California. At the close of 2013, California had experienced its driest year in recorded history, with severe drought continuing for the foreseeable future. Utah is the second driest state in the U.S., and therefore has been paying close attention to California’s current water crises. Water resource projections may prove to be one of the most vital pieces of information …

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 …

Sustainable Production Of Novel Biomaterials In Escherichia Coli, Asif Rahman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The biotechnology revenues in the United States exceeded $100 billion in 2010 and the potential impact of synthetic biological engineering has been identified nationally as an emerging technology to further expand the national bioeconomy. Synthetic biological engineering approaches biology from an engineering perspective to make biology easier to engineer. The potential to engineer microorganisms for novel applications can have far-reaching implications and benefits for society. Some of the potential applications range from biosensors, biofuels, therapeutics, and biomaterials.

In this study two biomaterials were produced in genetically engineered Escherichia coli: polyhydroxybutyrates (PHBs) and spider silk. PHBs are bioplastics that have …

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 …

Alkaloid Production By Hairy Root Cultures, Bo Zhao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the present research, nicotine alkaloid production by Nicotiana tabacum (tobacco) hairy roots and tropane alkaloid production by Hyoscyamus niger hairy roots were investigated. The first objective of this research was to improve the oxygen mass transfer in hairy root cultures with microbubbles. Oxygen was shown as a critical nutrient for the growth of tobacco and H. niger hairy roots. In a 1-liter fermentor, microbubble dispersion improved the oxygen mass transfer, tobacco hairy root growth, and nicotine production in the medium. In a novel ground-joint column bioreactor, microbubbles enhanced the oxygen mass transfer and the growth of H. niger hairy …

Landscape Evolution Of The Needles Fault Zone, Utah, Investigated Through Chronostratigraphic And Terrain Analyses, Faye L. Geiger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Arcing eastward from the deep gorge of Cataract Canyon on the Colorado River is a series of aligned valleys (graben) and ridges (horst). This unusual landscape has formed as subsurface salt deforms toward the river and dissolves away, causing the overlying rocks to fault, slide, and subside. Geologists have long been interested in this actively evolving area they call the Needles fault zone, because understanding its mechanics and origin may shed light on how faults work in general and similar, yet inaccessible places like offshore rift zones or even the surface of the Moon. Despite this interest, the timing and …

Metabolic Modeling Of Spider Silk Production In E. Coli, Sarah Allred

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider silk has the potential to be a useful biomaterial due to its high tensile strength and elasticity. It is also biocompatible and biodegradable, making it useful for wound dressings and sutures, tissue and bone scaffolds, vessels for drug delivery, and ligament and tendon replacements. In some studies where spider silk has been used to grow cells, the silk has promoted more cell growth than the control. However, it is difficult to obtain the high volume of silk needed for these undertakings on a large scale. Spiders are territorial and cannibalistic, so they cannot be easily farmed. Therefore, spider silk …

Information And Hardness Quantification Of Graphs: A Computational Study, Brent Dutson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

New techniques to measure the information contained within a network of interconnected nodes (such as links between computers in the Internet) have recently been developed. This work studies the relationship between the computer time needed to solve a common network problem and the information contained within the given network.

Impact Of Organic Matter Composition From Urban Streams And Storm Water On Oxygen Consumption In The Jordan River, Jacob Matt Richardson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The water quality of the Jordan River has been the subject of a Total Maximum Daily Load study conducted under the direction of the Utah Department of Environmental Quality's Water Quality Division (DWQ). They have determined the oxygen impairment issues in the river are most likely tied to the amount of organic material entering the river from various sources.

The focus of the study conducted by Jacob Richardson was organic material that enters the Salt Lake City storm drain system, and is eventually released into the Jordan River. He found that leaves, grass, and wood particles that enter the storm …

Distribution Of Heavy Metals From Flue Gas In Algal Bioreactor, Katerine Napan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Algae are microscopic organisms with a great potential to produce biomass and lipids at productivities several times higher than terrestrial crops. To grow, these organisms consume carbon dioxide (CO₂), a greenhouse gas. This gas, emitted primarily by power plants after coal burning, can be effectively used for algae production, thus resulting in CO₂ remediation and biomass beneficial utilization as feedstuff, industrial filler and biodiesel feedstock. However, since coal is a fuel mined from the earth’s crust, it contains heavy metals that are released during coal burning and inevitably enter the algal cultivation system, contaminating the water were …

Impact And Management Of Megacopta Cribraria (Hemiptera: Plataspidae), Nicholas Seiter

All Dissertations

Megacopta cribraria (F.) (Hemiptera: Plataspidae), known informally as the kudzu bug or bean plataspid, was found in Georgia in 2009 and has since spread rapidly throughout the southeastern United States. A known feeder on soybean, Glycine max (L.) Merrill, in its native Asian range, M. cribraria has been commonly encountered in soybean fields in the southeastern United States since its first detection in the crop in Georgia and South Carolina during 2010. In addition, its overwintering behavior sometimes results in nuisance infestations in homes. The primary objectives of this research were to determine the potential impacts of M. cribraria on …

Inkjet Printing Of Three-Dimensional Vascular-Like Constructs From Cell Suspensions, Changxue Xu

All Dissertations

Inkjet printing has found an increasing number of biofabrication applications, specifically organ printing, which has been emerging as a promising solution to the organ donor shortage. While some studies have been conducted to investigate various engineering problems associated with DOD inkjet printing of biological material-based fluids, the pinch-off, the cell-laden droplet formation, the effects of electric field on droplet formation, and challenges in 3D vascular-like construct fabrication haven't been systematically investigated. The objective of this study is to investigate the pinch-off, the cell-laden droplet formation, the effects of electric field on droplet formation, and manufacturing challenges during fabrication using DOD …

The Contagion Of Sharing: Rhetorics Of Community In An Age Of Digital Media, Jared Colton

All Dissertations

This dissertation, entitled 'The Contagion of Sharing: Rhetorics of Community in an Age of Digital Media,' interrogates the relationship between rhetoric, ethics, and politics in community building, practice, and critique in an age of online communities and new media writing. I focus on how rhetoric and composition scholars overemphasize the role inclusion plays in communal phenomena and that not enough attention is paid to understanding how community practices and processes require both sharing and protection, identity and difference, and thus, inclusion and exclusion. I argue that, as teachers of rhetoric and writing, if we intend to help students write for, …

Cardiovascular Tissue Engineered Constructs For Patients With Diabetes, James Chow

All Dissertations

Clinical translation of cardiovascular tissue engineering (CVTE) is rapidly shifting from concept to application, granting a myriad of opportunities for the treatment of cardiovascular disorder (CVD). There remains, however, a critical hurdle to overcome: the application of tissue engineering to a comprised patient - more specifically, a patient with diabetes mellitus (DM). The alarming prevalence of DM is of great concern due to its duel threat as both a risk factor for CVD and a predictor of biomedical device failure. Elevated levels of inflammation and impaired wound healing are hallmarks of DM contributing to cardiomyopathy, atherosclerosis, and valve disease. The …

Range Limits, Range Shifts, And Lower Thermal Tolerance In The Tropical Barnacle Megabalanus Coccopoma, Samuel Crickenberger

All Dissertations

Climate change and species introductions are leading to shifts in marine species' geographic distributions. However, few studies have examined range limits and range shifts in tropical marine species. The barnacle Megabalanus coccopoma is native to shorelines from Baja California to Peru and has been introduced to a number of locations worldwide including the Atlantic US SE coast, where its current introduced range extends from Ft. Pierce, FL to Cape Hatteras, NC with seasonal populations as far north as Kitty Hawk, NC. In order to understand the potential poleward range limit of M. coccopoma in the US SE under modern day …

Public School Credits For Devotional Courses In Religion: The Evangelical Reconceptualization Of Released Time, Benjamin James Bindewald

All Dissertations

Released time is an arrangement through which students are excused from public schools, during regular hours, to participate in devotional lessons conducted by local religious organizations. The courts have upheld this practice as long as classes are held off public school premises, with parental permission, and without government aid. South Carolina has become the center of operations for a movement of evangelical Christians to expand proselytizing released time programs throughout the United States. As a result of the movement’s lobbying efforts, in 2006 South Carolina became the first state to enact legislation allowing public schools to award graduation credits for …

Impact Of Physical And Psychosocial Workplace Hazards On Employee Health: An Irish T Ale Of Civil Servant Workers, Kyle R. Stanyar

All Dissertations

Obesity, mental health problems, and absenteeism are both economic and health burdens for employers and employees. Research suggests that physical and psychosocial hazards in the workplace contribute to health risks and health problems among employees. There is a need for researchers to examine how exercise, diet, and age interact with the negative effects of workplace hazards upon health. Hypotheses 1a through 3b predicted that physical and psychosocial workplace hazards would negatively impact body mass index (BMI), general mental health, and sickness absences. Further, hypotheses 4a through 9b predicted that exercise and diet would buffer stress from occupational hazards upon BMI, …

The Effects Of Indirubin-3’-(2,3 Dihydroxypropyl)-Oximether (E804) On Inflammation Profile In Macrophages, Amy Lauren Anderson

All Dissertations

Indirubin is a deep-red bis-indole isomer of indigo blue, both of which are biologically active ingredients in Danggui Longhui Wan, an ancient Chinese herbal tea mixture used to treat neoplasia and chronic inflammation, and to enhance detoxification of xenobiotics. Multiple indirubin derivatives have been synthesized and shown to inhibit cyclin-dependent kinases (CDKs) and glycogen-synthase kinase (GSK-3β) with varying degrees of potency. Several indirubins are also aryl hydrocarbon receptor (AhR) agonists, with AhR-associated activities covering a wide range of potencies, depending on structure-activity-relationships (SAR). In this study, the effects on indirubin-3’-(2,3 dihydroxypropyl)-oximether (E804), a novel indirubin derivative with potent effects on …

Pretreatment Development Of Lignocellulosic Feedstocks For The Production Of Bioproducts, Arpan Jain

All Dissertations

Three different lignocellulosic feedstocks – switchgrass, sweet sorghum bagasse and pine wood chips, were analyzed for the production of bioproducts (sugars and enzymes). High sugar content of these feedstocks could be utilized either in the production of enzymes, biofuel and paper/pulp. Utilization of lignocellulosic feedstock in any production processes require preprocessing to remove phenolic compounds (lignin). Lignin acts as a barrier and protects the structure of polysaccharides from oxidation. Removal of lignin (delignification) leads to maximum utilization of lignocellulosic polysaccharides, mainly glucan and xylan in bioproducts production. The effect of pretreatment on ground switchgrass were evaluated through enzyme production and …