Digital Commons Network^™

Mechanisms Of The Extreme Sensitivity Of Turkeys To Aflatoxin B1, Sumit Rawal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The pathogenesis of hepatotoxic and hepatocarcinogenic actions of the mycotoxin aflatoxin B1 (AFB1) involves initial bioactivation by microsomal cytochrome P450s (P450) to a reactive and electrophilic intermediate, exo-aflatoxin B1-8,9-epoxide (exo-AFBO). Poultry, especially turkeys, are extremely sensitive to AFB1, a condition associated with efficient epoxidation by P450s. The purpose of this research was to 1) discover and characterize the P450s in turkey liver responsible for AFB1 bioactivation, and 2) determine the relative importance of these P450s in turkey liver.

Initial investigations led to the discovery of CYP1A5. We then identified CYP3A37, a human CYP3A4 homologue from turkey liver, …

Design And Scale-Up Of Production Scale Stirred Tank Fermentors, Ryan Z. Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the bio/pharmaceutical industry, fermentation is extremely important in pharmaceutical development, and in microbial research. However, new fermentor designs are needed to improve production and reduce costs of complex systems such as cultivation of mammalian cells and genetically engineered micro-organisms. Traditionally, stirred tank design is driven by the oxygen transfer capability needed to achieve cell growth. However, design methodologies available for stirred tank fermentors are insufficient and many times contain errors. The aim of this research is to improve the design of production scale stirred tank fermentors through the development of dimensionless correlations and by providing information on aspects of …

Biological And Mechanical Approaches To Sunscald Management In Bell Pepper Production, Samuel D. Day

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Producing red bell peppers in high temperature and light environments can be challenging because many new semi-indeterminate varieties produce small plant canopies that leave fruit exposed to damage (sunscald) caused by solar radiation. Pepper production in Utah coincides with high air temperatures and solar radiation levels during July, August, and September. Increasing plant canopy size is one way to protect fruit from solar radiation. Low tunnels optimize plant growth by increasing air and soil temperatures. Growing plants under low tunnels early in the season could increase fruit shading later in the season. Another way to protect fruit is by using …

The Influence Of Collective Action And Policy In The Development Of Local Food Systems, Lori Porreca

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The modern global agrifood system has had significant negative impacts on consumers and producers. This has precipitated the rise of local food systems that are purported to improve the health and livelihoods of consumers and producers. High expectations have led to significant public and private resources dedicated to the development of local food systems. Despite this, there has been little systematic research exploring the social and institutional conditions that facilitate or frustrate local food system development.

Using a comparative case study approach, this study explored the ways local structural conditions, collective action, food system policies, and the political context affect …

Evapotranspiration Of Kentucky Bluegrass, Lynda L. Fenton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid population growth in arid regions of the western US is placing increased demand on water resources. Variability in precipitation and common occurrence of drought have promoted scrutiny of water use in urban lawns and gardens. However, few reliable measurements of water use of these landscapes exist. Quantifying the amount of water used vs. required by landscapes such as turfgrass would allow significant water conservation. Evapotranspiration (ET) is affected by biophysical factors such as: available energy, turbulent mixing, saturation deficit, soil water, and stomatal conductance. In order to simulate the water use by turfgrass, the relative importance of these processes …

Comparative Performance Of Fluorometry And High Performance Liquid Chromatography In The Detection Of Aflatoxin M1 In Two Commercial Cheeses, Gustavo Peña

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aflatoxin M1 (AFM₁) is frequently found in milk and dairy products. It is a metabolite formed in cows from aflatoxin B1 (AFB₁), contained in animal feeds. In cheese production AFM₁ distributes between curds and whey. In this study, cows were fed 64 µg/AFB₁/d for the high treatment, and 5 µg/AFB₁/d for the low treatment, to obtain milk contaminated with AFM1 over the 0.5 µg/L and under 0.05 µg/L restrictions, respectively. Cheese was manufactured with milk contaminated with AFM₁ at 0.8 and 0.03 ìg/kg by the higher and lower …

Survival Of Mycoplasma Species In Recycled Bedding Sand And Possible Implications For Disease Transmission To Ruminants, Anne E. Justice-Allen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mycoplasmas are a group of bacteria which are small in size, lack a cell wall, and have small genomes in comparison to other bacteria. The members of the group that are pathogenic utilize several mechanisms to evade the host's immune system. These processes affect surveillance and control mechanisms such as serologic testing and vaccination. Many of these organisms cause diseases of livestock, which heavily impact production parameters such as weight gain, milk yield, and egg production. Mycoplasmas also cause disease in people.

Mycoplasma spp. can cause mastitis, metritis, pneumonia, and arthritis. The currently documented routes of transmission of Mycoplasma spp. …

Synchronization And Media Exchange In Large-Scale Caenorhabditis Elegans Cultures, Jason D. Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The nematode Caenorhabditis elegans is a model organism for understanding sensory molecules of multicellular organisms. Ovulating hermaphrodites produce putative pheromone(s) that cause male attraction. Because pheromones are produced in such small quantities, adult conditioned-media from large-scale synchronous culture is necessary to analyze these pheromones. Current protocols for culture synchronization have volume constraints that limit large-scale synchronous cultures and current methodology for adult conditioned-media production is impractical.

Modification of Tangential Flow Filtration (TFF) systems was investigated for use as a method to increase the volume limits of bleach egg harvest for C. elegans culture synchronization. Also, an adult retention device built …

Summer Home Range Fidelity In Adult Female Elk (Cervus Elaphus) In Northwestern Colorado, April M. Brough

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the degree of spatial fidelity of individuals within a species increases our ability to manage appropriately. Elk (Cervus elaphus) is a highly managed species in the Intermountain West, but there is little research evaluating summer home range fidelity of individual elk. We evaluated fidelity of 72 adult female elk to individual summer-fall home ranges in the White River study area in northwestern Colorado during two consecutive summers. Based on individual kernel-estimated utilization distributions, we used (1) the Volume of Intersection (VI) statistic and (2) interannual distances between centers of mass to compare summer range overlap and distribution. …

A Comparison Of Soil Moisture And Hillslope-Stream Connectivity Between Aspen And Conifer-Dominated Hillslopes Of A First Order Catchment In Northern Utah, Amy R. Burke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain headwater catchments in the semi-arid Intermountain West are important sources of surface water because these high elevations receive more precipitation than neighboring lowlands. The hydrology of these mountain catchments is especially important as the region faces water shortages and conflicts. Conifer encroachment on aspen stands has been observed across the western US and can result in a decline in water yield. The overall objective of this study was to further our understanding of hillslope-stream connectivity in a headwater catchment of Northern Utah and any observable differences in this connection between aspen and conifer hillslopes. Hillslopes are the fundamental unit …

Effects Of Coyote Removal On Pronghorn And Mule Deer Populations In Wyoming, Dylan Earl Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I studied the relationship between coyote (Canis latrans) removal and pronghorn (Antilocapra americana) and mule deer (Odocoileus hemionus) density and fawn:doe ratios in southwest Wyoming and northeast Utah in 2007 and 2008. Coyote removal variables studied included the number of coyotes removed, ground hours worked, total hours worked, coyotes removed/aerial gunning hour, coyotes removed/ground work hour, and coyotes removed/total effort hour. None of the variables explained changes observed in fawn:doe ratios of pronghorn or mule deer. The number of coyotes removed, ground hours worked, total hours worked, and coyotes removed/aerial gunning hour were positively …

A Pilot Study Examining The Use Of Technologically Assisted Psychotherapeutic Intervention In The Delivery Of Therapy To Women With Anxiety Residing In Rural Utah Communities, Benjamin K. Farmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to examine change in symptoms of anxiety and satisfaction experienced by participants who received acceptance and commitment therapy (ACT) by using technologically assisted psychotherapeutic interventions (TAPI). TAPI utilizes the internet as a medium to make mental health services available and accessible to people residing in rural communities. The participants in this study were women who were experiencing severe levels of anxiety and lived in a rural community. Measures were taken at three different points in the study (pretherapy, posttherapy, and 6-months posttherapy). Participants received therapy over the internet via Macromedia Breeze videoconferencing to reduce …

The Effects Of Social Status And Learning On Captive Coyote (Canis Latrans) Behavior, Lynne Barbara Gilbert-Norton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many canids live within hierarchical social systems that could promote differences in learning or in behavior between ranked individuals. Differences in foraging and territorial behavior have been observed between ranked coyotes (Canis latrans), yet effects of learning and social status on coyote behavior are not thoroughly understood. I explored a) coyote response to an artificial scent boundary and whether response differed by status, b) how foraging coyotes tracked temporal resource change, and c) how coyotes find spatially distributed food, and the effect of dominance on foraging behavior. I used male/female pairs of captive coyotes at the National Wildlife Research Center …

Ecological Effects Of Genotypic Diversity On Community And Ecosystem Function, Megan K. Kanaga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Genotypic diversity within populations can have important evolutionary consequences, but the ecological effects of intraspecific genetic variation on community and ecosystem function have only been studied in a few systems. I present the results of a three-year study designed to address the ecological impacts of genotypic diversity in quaking aspen (Populus tremuloides Michx.), using aspen genotypes planted across genotypic diversity levels (monoculture and mixture) and watering treatment levels (well-watered and water-limited). First, I demonstrated that significant variation exists among genotypes for a wide range of growth, morphological and physiological traits, and quantified high heritability and coefficient of genetic variation …

Herbicide, Salinity, And Flooding Tolerance Of Foxtail Barley (Hordeum Jubatum L.) And Desirable Pasture Grasses, Karl R. Israelsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research trials performed in the greenhouse compared the tolerance and response of Hordeum jubatum and desirable pasture grass species to herbicides, salinity, and flooding. Desirable grass species used in this study included: 'Fawn' tall fescue (Festuca arundinaceae), 'Garrison' creeping foxtail (Alopecurus arundinaceus), 'Palaton' reed canarygrass (Phalaris arundinacea), 'Climax' timothy (Phleum pratense), 'Alkar' tall wheatgrass (Thinopyrum ponticum), 'Potomac' orchardgrass (Dactylis glomerata), and 'Mustang' altai wildrye (Leymus angustus). Tolerance to herbicides, salinity, and flooding varied significantly among grass species. Herbicide tolerance was tested using four herbicides at five …

Removal And Utilization Of Wastewater Nutrients For Algae Biomass And Biofuels, Erick W. Griffiths

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Logan City Environmental Department operates a facility that consists of 460 acres of fairly shallow lagoons (~ 5'deep) for biological wastewater treatment that meets targets for primary and secondary treatments (solids, biological oxygen demand (BOD), and pathogen removal). Significant natural algal growth occurs in these lagoons, which improves BOD removal through oxygenation and also facilitates N removal through volatilization as ammonia under high pH conditions created by algal growth. Phosphorus, however, is non-volatile and stays in the water and likely cycles in and out of algal cells as they grow and die in the lagoons. In the near future, …

Conservation Design Guidelines For Botanic Gardens, C. Craig Houston

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Botanic gardens worldwide are asked to be centers of conservation. However, little is written about conservation-specific planning and design forms botanic gardens should use to fulfill this assignment. After looking at the history of botanic gardens, with a focus on the purpose/design relationship, examining design guidelines suggested in and inferred from the literature, and presenting habitat conservation principles and sustainable construction guidelines from other areas of practice, the author developed conservation design guidelines for botanic gardens focused on conservation. The guidelines address the following five categories: (1) Mission Statement and Site Character, (2) Presentation of Native Habitats, (3) Presentation of …

Designing An Instrument Based On Native Fluorescence To Determine Soil Microbial Content At A Mars Analog Site, Heather D. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For this research project we designed an instrument to detect bacteria via biomolecular fluorescence. We introduce the current understanding of astrobiology, our knowledge of life beyond Earth, and the commonality of Earth life as it pertains to the search for life on Mars. We proposed a novel technique for searching for direct evidence of life on the surface of Mars using fluorescence. We use the arid region of the Mojave Desert as an analog of Mars. Results indicate the fluorescence of the biotic component of desert soils is approximately as strong as the fluorescence of the mineral component. Fluorescence laboratory …

Geometry And Electronic Structure Of Doped Clusters Via The Coalescence Kick Method, Boris Averkiev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Developing chemical bonding models in clusters is one of the most challenging tasks of modern theoretical chemistry. There are two reasons for this. The first one is that clusters are relatively new objects in chemistry and have been extensively studied since the middle of the 20th century. The second reason is that clusters require high-level quantum-chemical calculations; while for many classical molecules their geometry and properties can be reasonably predicted by simpler methods.

The aim of this dissertation was to study doped clusters and explain their chemical bonding. The research was focused on three classes of compounds: aluminum clusters doped …

Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digital soil mapping (DSM) relies on quantitative relationships between easily measured environmental covariates and field and laboratory data. We applied innovative sampling and inference techniques to predict the distribution of soil properties, soil attributes, taxonomic classes, and dominant vegetation across a 30,000-ha complex Great Basin landscape in southwestern Utah. This arid rangeland was characterized by rugged topography, diverse vegetation, and intricate geology. Environmental covariates calculated from digital elevation models (DEM) and spectral satellite data were used to represent factors controlling soil development and distribution. We investigated optimal sample size and sampled the environmental covariates using conditioned Latin Hypercube Sampling (cLHS). …

Factors Associated With Physical Activity Behaviors Among Rural Adolescents, Kenli A. Urruty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The "obesity epidemic" in the United States is a current health concern that has sparked research interest in physical activity as a means of weight management. However, little research has examined the physical activity behaviors of rural adolescents. The goal of the current study was to use a biopsychosocial framework to examine the physical activity behaviors of a sample of rural adolescents, and explore factors associated with physical activity participation.

A sample of 162 ninth- and tenth-grade students in a rural, western community were recruited for this study. Generally, the sample reported levels of physical activity for both genders that …

Quantifying Surface Water And Groundwater Interactions In A High-Gradient Mountain Stream For Solute Transport, Noah M. Schmadel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study reach in a mountain stream highly influenced by groundwater was selected to test common data collection strategies used to characterize and quantify groundwater exchange processes necessary to predict solute transport. The data types collected include: high frequency discharge estimates with the use of rating curves, dilution gauging techniques with instantaneous tracer experiments, groundwater table and stream water surface elevations, vertical head gradients, and hydraulic conductivity estimates. The first two data types were categorized as stream gauging and the remaining three data types as site characterization. The stream gauging data were used to quantify net changes in stream discharge …

The Effect Of Irrigation Diversions On The Mountain Whitefish (Prosopium Williamsoni) Population In The Big Lost River, Patrick Allen Kennedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Management agencies documented a decline in the mountain whitefish (Prosopium williamsoni) population on the Big Lost River, and unscreened diversions were recognized as a potential factor for this decline. Research suggests the Big Lost River mountain whitefish population is genetically unique, and it has been petitioned for protection under the Endangered Species Act. In 2007, a basin-wide synopsis of diversions was conducted to describe relative entrainment and identify diversions that entrained the most mountain whitefish. This larger scaled synopsis facilitated a more precise assessment of entrainment by a subset of diversions in 2008. In 2008, the volume that …

Information Retrieval Using The Constructivist's Approach To Get The Most Out Of The Internet, Ishani Shukla

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The constructivist's theory and its application to information retrieval from the Internet was reviewed. The main aim of the study was to devise and test an approach with which the most relevant information could be easily and efficiently extracted from the Internet. The impact of a judicious choice of the keywords to retrieve information, according to the particular approach to be implemented as well as the importance of speed reading as an additional technique to improve information retrieval, was compared and critically analyzed. The study was based on information retrieval from www.google.com and www.images.google.com and focused on real-life examples and …

Investigating Methods To Reduce Black Bear (Ursus Americanus) Visitation To Anthropogenic Food Sources: Conditioned Taste Aversion And Food Removal, Kari D. Signor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Conflicts between humans and black bears (Ursus americanus) jeopardize the safety of both humans and bears, especially when bears become food-conditioned to anthropogenic food sources in areas such as campgrounds. Interest in using non-lethal techniques, such as aversive conditioning, to manage such conflicts is growing. I conducted a captive experiment at The Wildlife Science Center in Minnesota and two field experiments in the La Sal Mountains, Utah, to investigate the effects of taste aversion conditioning using thiabendazole (TBZ) with a novel flavor cue and food removal on black bear food consumption and visitation to human food sources. In …

River Network Structure: A Template For Understanding Predator-Prey Dynamics And Potential Anthropogenic Impacts, Catherine L. Hein

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A landscape perspective is critically important for understanding community structure, particularly in systems dominated by migratory fauna. I aimed to understand how the structure of riverscapes in Puerto Rico mediates potential anthropogenic impacts, predator-prey interactions, and the migratory behavior of a diadromous species. I surveyed fishes and shrimps at sites throughout two watersheds, designed transplant experiments that investigated the role of natural barriers on predator-prey interactions, and developed models of shrimp migration specific to a particular river network. I did not detect an effect of anthropogenic changes to the landscape on fish and shrimp species distributions in two watersheds that …

Individual Endorsement Of Remarriage Beliefs, Consistency Of Cognitions Between Spouses, And Outcomes In Remarriage, Lyndy Sue Agee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Despite the increasing prevalence of remarriages over the last several decades, little work has been done in establishing theories and models specific to remarried couples and stepfamilies. To address this gap, the multidimensional cognitive development model for individuals in stepfamilies was utilized. To evaluate the model, this study tested the consistency tenet, which is central to the model. Consistency of cognitions is assumed to be of primary importance in stepfamily relationships and a balanced system is one that is defined by consistency of cognitions. Data were analyzed from the "Relationship Quality and Stability in Utah Newlywed Remarriages" study. With a …

Greater Sage-Grouse Ecology, Chick Survival, And Population Dynamics, Parker Mountain, Utah, David K. Dahlgren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We estimated survival of ~ 1-day-old chicks to 42 days based on radio-marked individuals for the Parker Mountain greater sage-grouse (Centrocercus urophasianus) population. Chick survival was relatively high (low estimate of 0.41 and high estimate of 0.50) compared to other studies. Brood-mixing occurred for 21 % of radio-marked chicks, and within 43 % of radio-marked broods. Our study showed that brood-mixing may be an important ecological strategy for sage-grouse, because chicks that brood-mixed experienced higher survival. Additionally, modeling of chick survival suggested that arthropod abundance is important during the early brood-rearing period (1 - 21 days). We also …

Optimal Compost Rates For Organic Crop Production Based On A Decay Series, Jeffrey B. Endelman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the more challenging aspects of organic farming is the development of an appropriate fertility plan, which may include crop rotation, cover crops, and/or soil amendments. When fertility is maintained by applying manure and/or compost, a pressing question is how much should be used. A framework was developed to address this question based on the idea of a decay series, which is a sequence of numbers quantifying the effects of compost on crop yield over a multi-year period. Prior research has focused on decay series expressed in nitrogen fertilizer equivalents. Given this information, I show how to calculate what …

Predation On Domestic Sheep On Summer Range Lands In Southwestern Utah, Brian Carl Palmer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Much of the decline of the U.S. sheep industry has been attributed to losses caused by predators. Most predatory losses are inflicted on lambs rather than ewes. Losses have historically ranged from 4-8% of lamb crops, inflicting significant financial loss on ranchers. However, most research providing data on sheep predation is over 20 years old. Changes in the sheep industry as well as predation rates may make previous loss rates inapplicable to current conditions. Coyotes (Canis latrans) are the primary predator of concern when it comes to sheep losses, but increasingly, cougars (Felis concolor) and black …