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The Effects Of Laser Etching On Biocompatability And Mechanical Properties Of Polyetheretherketone, Andrew I. Deceuster

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polyetheretherketone (PEEK) is a Federal and Drug Administration (FDA) approved biomaterial that has been used as an orthopedic implant material due to its inherent properties. Laser etching has become a popular means to create identification markers on the individual implants as required by the FDA. The interaction of laser energy with polymeric materials could potentially cause changes in the material's biocompatibility and mechanical properties. The objective of this study was to determine the effect of laser energy on the biocompatibility and mechanical properties of implantable PEEK by measuring contact angle, micro-tensile testing, nite-element modeling (FEM), and biocompatibility testing according to …

The Impact Of Social Support, Psychosocial Characteristics, And Contextual Factors On Racial Disparities In Hypertension, E. Miranda Reiter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hypertension is a serious medical condition. Although men and women of all racial groups in the US suffer from high blood pressure, black women have the highest rates of hypertension. For instance, the age-adjusted prevalence of hypertension among black women ages 20 and over is 44.3, compared to 28.1 among white women, 40.5 among black men, and 31.1 among white men.

Past research has focused on SES and behavioral factors as potential explanations for blood pressure disparities between black and white women. But, even after controlling for such factors, considerable disparities remain. The goal of this research is to examine …

Structure And Multi-Center Bonding: From Atomic Clusters To Solid Phase Materials, Timur R. Galeev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The work presented in this dissertation has been focused on structure, stability, and chemical bonding of atomic clusters and solid-state compounds. The common thread was development of theoretical models and methods capable of interpreting bonding and hence, structures of these species. A major part of this work presents joint experimental and theoretical studies of a large series of doped boron clusters. The dissertation introduces a new theoretical tool for interpretation of bonding of solid phase materials in chemically intuitive terms of localized and multi-center bonds. Understanding how interactions between atoms in sub-nano clusters and solid-state compounds determine their structures, physical …

Computational Models Of Intracellular And Intercellular Processes In Developmental Biology, Ahmadreza Ghaffarizadeh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Systems biology takes a holistic approach to biological questions as it applies mathematical modeling to link and understand the interaction of components in complex biological systems. Multiscale modeling is the only method that can fully accomplish this aim. Mutliscale models consider processes at different levels that are coupled within the modeling framework. A first requirement in creating such models is a clear understanding of processes that operate at each level. This research focuses on modeling aspects of biological development as a complex process that occurs at many scales. Two of these scales were considered in this work: cellular differentiation, the …

Expert Vs. Novice: Problem Decomposition/Recomposition In Engineering Design, Ting Song

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate the design behavior. A commonly used design strategy called “problem decomposition and recomposition” was the focus of the study. Dyads of engineering experts, dyads of engineering seniors, and dyads of engineering freshmen completed an engineering design challenge within an hour. The entire design process was video and audio recorded. After the design session, participants participated in a group interview.

The conversation and behavior from the design were transcribed, segmented, and coded. Two coding systems including the FBS ontology and “levels of the problem” were used in this study. A series of statistical …

Bridging The Nano- And Macro-Worlds: Thermal Property Measurement Using Thermal Microscopy And Photothermal Radiometry – Application To Particle-Irradiation Damage Profile In Zirconium Carbide, Colby Bruce Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiscaled experimental investigations of heat transfer from nanoscales to macroscales are requisite to progress in energy technologies. In nuclear applications, material properties can undergo significant alteration due to destructive interaction with irradiating particles at microstructural levels that affect bulk properties. This study expands the current knowledge base regarding thermal transport in ion-irradiated materials through the use of a multiscaled experimental approach using four complementary thermal wave methods. For the first time, the in-depth thermal conductivity profile of an ion-irradiated sample is measured directly.

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). …

American Bison Ecology And Bison-Cattle Interactions In An Isolated Montane Environment, Dustin H. Ranglack

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As bison are considered to be ecologically extinct, and negative interactions between bison and cattle are perceived to limit bison restoration and cattle production, I designed a series of studies to test for potential competition between bison (Bison bison) and cattle (Bos taurus) for forage on the Henry Mountains in southern Utah. These studies provide insight into key information gaps previously identified by the Utah Division of Wildlife Resources (UDWR), Bureau of Land Management, and the local grazing association. The results indicate that bison and cattle are not strong competitors for forage on the Henry Mountains. …

Evaluating Process- And Constraint-Based Approaches For Modeling Macroecological Patterns, Xiao Xiao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Macroecological patterns, such as the highly uneven distribution of individuals among species and the monotonic increase of species richness with area, exist across ecological systems despite major differences in the biology of different species and locations. These patterns capture the general structure of ecological communities, and allow relatively accurate predictions to be made with limited information for under-studied systems. This is particularly important given ongoing climate change and loss of biodiversity. Understanding the mechanisms behind these patterns has both scientific and practical merits.

I explore two conceptually different approaches that have been proposed as explanations for ecological patterns – the …

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 …

Ringtail Distribution, Dermatoglyphics, And Diet In Zion National Park, Utah, Adrian Argie Roadman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Current scientific knowledge of the ringtail (Bassariscus astutus) is limited, thus impeding appropriate management decisions. Ringtails in Zion National Park, Utah, are rarely seen, but are involved in increasing occurrences of negative interactions with park visitors and employees such as food theft and denning in buildings, interactions which are harmful to both parties. To manage this conflict, an update to the general knowledge about the status of the population is required as the only previous study on ringtails in this area was conducted in the 1960s. Using noninvasive techniques provides dependable large-scale population information. I used two noninvasive detection methods …

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 …

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 …

Effect Of Poultry Litter Biochar On Saccharomyces Cerevisiae Growth And Ethanol Production From Steam-Exploded Poplar And Corn Stover, Oumou Diallo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The use of ethanol produced from lignocellulosic biomass for transportation fuel offers solutions in reducing environmental emission and the use of non-renewable fuels. However, lignocellulosic ethanol production is still hampered by economic and technical obstacles. For instance, the inhibitory effect of toxic compounds produced during biomass pretreatment was reported to inhibit the fermenting microorganisms, hence there was a decrease in ethanol yield and productivity. Thus, there is a need to improve the bioconversion of lignocellulosic biomass to ethanol in order to promote its commercialization. The research reported here investigated the use of poultry litter biochar to improve the ethanol production …

Synthesizing Research And Education: Ecology And Genetics Of Independent Fern Gametophytes And Teaching Science Inquiry And Content Through Simulations, Aaron M. Duffy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mission statements of Utah State University and the Department of Biology, as well as the requirements of funding agencies like the National Science Foundation encourage an integration of teaching and research. I have attempted to achieve that in my dissertation work by using tools I originally created to support and inform my biological research projects to teach science content and inquiry to middle school and undergraduate students.

Chapter 2 of this dissertation reports the results of surveys for Hymenophyllum wrightii, a fern with independent gametophyte populations in the Pacific Northwest, which improved our understanding of the range, distribution, …

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.

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 …

Effects Of Processing And Packaging Modifications On The Quality And Shelf Life In Meats, Abdulla Khan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Shelf life of foods, mainly meat and meat products, is affected by its physical and chemical properties like color, pH, water holding capacity etc. In developed countries
food losses occur at production, retail and consumer levels with meat commodities accounting for 41% of the total loss in US during 2008. These losses are because of
spoilage due to inappropriate packaging, improper storage conditions, food wastage, and lack of consumer awareness. By focusing on shelf life and quality issues at the production level, we can overcome some of the major problems faced by the food manufacturers.

Active packaging is an innovative …

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 …

Self-Reported Psychopathology Correlates Of Homeless Youth In Utah, Kimberlee Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Homelessness among unaccompanied youth is a unique, yet pervasive, social problem. Youth often become homeless through three central pathways: conflict with family, involvement in the foster system, and involvement in juvenile justice systems. As youth experience homelessness during important developmental period(s), vulnerability to mental illness may occur if not already present. The present study examined the type and prevalence of mental illness. Characteristics of homelessness, health and mental health service utilization, and pathways to homelessness were examined in relation to the occurrence of mental illness. Findings indicated that a variety of characteristics are associated with mental illness. Mental health service …

Specific Learning Disabilities: Beliefs About The Construct, Identification Methods, And Job Satisfaction Among Practicing School Psychologists, Joseph M. Cottrell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Students with specific learning disabilities (SLDs) account for approximately 40% of all students receiving special education services. Debate among professionals regarding the causes of SLDs and the most appropriate methods used to identify SLDs persists. This debate may be related to the increase in prevalence of SLDs since the implementation of special education law in 1975. There are three prominent theories regarding the cause of SLDs: (a) environmental theory, (b) biological theory, and (c) interactional theory. The Individuals with Disabilities Education Act (IDEA) allows school districts to implement the following SLD identification procedures: (a) the IQ-Achievement discrepancy method, (b) response-to-intervention …

Effects Of Dietary Polyunsaturated Fatty Acids On Colorectal Cancer And The Development Of The Total Western Diet-2, Sara Kellen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Western diet is commonly consumed by industrialized societies and characterized by an increased consumption of vegetable oils rich in omega-6 (n-6) fatty acids. This results in a higher ratio of omega-6 to omega-3 (n-3) fatty acids in the diet. Omega-6 polyunsaturated fatty acids (PUFA) are believed to induce a pro-inflammatory response in the body. Therefore, this change in PUFA concentration and/or ratio of n-6:n-3 in the Western diet may contribute to colorectal cancer (CRC) risk. Five identical diets, varying only in PUFA concentration and n-6:n-3 ratio, were fed to mice dosed with a carcinogen and an inflammatory accent (AOM+DSS). …

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 …

Trophic Status, Energetic Demands, And Factors Affecting Lahontan Cutthroat Trout Distribution In Pyramid Lake, Nevada, Nicholas A. Heredia

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The progression of human development across the landscape has caused declines to both terrestrial and aquatic fauna. Many fishes, specifically native salmonids, have seen reductions in both population size and geographic distribution resulting from reduced habitat, overharvest, and the introduction of non-native predators and competitors. A native North American fish particularly hard hit by these types of actions, Lahontan cutthroat trout, are now limited to less than 10% of their historical habitat, and currently occupy only half of the lakes that they once occupied.

In Pyramid Lake, Nevada, where Lahontan cutthroat trout were once locally extinct, due to overfishing, water …

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 …