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All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

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Sonication Assisted Synthesis Of Oligomannosides, Christabel Tomla Tanifum May 2009

Sonication Assisted Synthesis Of Oligomannosides, Christabel Tomla Tanifum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oligomannosides prevalently exist as cell surface antigens. They play important roles in diseases such as viral infection and cancer, and they have been shown to be useful as candidates for vaccines. HIV, one of the most devastating modern diseases, has a high content of mannose sugars on its envelope glycoprotein gp120. Oligomannosides of the HIV virus, also called Man9, which are found on the glycoprotein gp120, have been shown to play a protective role for the HIV virus, shielding highly conserved protein domains of gp120 from proteolytic attacks. Thus gp120 plays an important role in HIV infection of cells, being …


Feasibility Analysis Of Seed Production For Use In Re-Seeding Land Burned In Wildfires In The Great Basin Region Of The United States, Benjamin Jay Young May 2009

Feasibility Analysis Of Seed Production For Use In Re-Seeding Land Burned In Wildfires In The Great Basin Region Of The United States, Benjamin Jay Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Native and introduced grass and shrub species are grown for seed production in the Great Basin region of the United States. The purpose of this research is to evaluate the profitability and risk associated with the production of five different species of grasses and shrubs which are used in rehabilitation following wildfires. Enterprise budgets are constructed for both the establishment and production years. Returns above operating costs are compared to other crops produced in the same region. Production and market risks are discussed. Returns and risks are evaluated using an expected value model which compares risk and return between species, …


Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker May 2009

Consequences Of Vegetation Change On The Dynamics Of Labile Organic Matter And Soil Nitrogen Cycling In A Semiarid Ecosystem, Toby D. Hooker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sagebrush-dominated ecosystems are being transformed by wildfire, rangeland improvement techniques, and exotic plant invasions. These disturbances have substantial effects on the composition and structure of native vegetation, but the effects on ecosystem C and N dynamics are poorly understood. To examine whether differences in dominant vegetation affect the quantity and quality of plant organic matter inputs to soil, ecosystem C and N pools and rates of plant turnover were compared among historically grazed Wyoming big sagebrush, introduced perennial crested wheatgrass, and invasive annual cheatgrass communities. Since low soil moisture during the summer may inhibit the microbial colonization of plant detrital …


Consumer-Driven Nutrient Recycling In Arctic Alaskan Lakes: Controls, Importance For Primary Productivity, And Influence On Nutirient Limitation, Cody R. Johnson May 2009

Consumer-Driven Nutrient Recycling In Arctic Alaskan Lakes: Controls, Importance For Primary Productivity, And Influence On Nutirient Limitation, Cody R. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In lakes, fish and zooplankton can be both sources and sinks of nitrogen (N) and phosphorus (P) through the consumption of organic N and P, and subsequent excretion of bioavailable inorganic forms. These source/sink dynamics, known as consumer-driven nutrient recycling (CNR), may, in turn, control the availability of potentially limiting nutrients for algal primary production. In this dissertation I investigate the importance and controls of CNR as a source of inorganic N and P for primary production (Chapter 2). I then examine zooplankton CNR as a mechanism for increasing nutrient mean resident time (MRT) in the mixed layer of lakes …


Punta Toro Virus Infection In Mice: Strain Differences In Pathogenesis And Regulation Of Interferon Response Pathways, Michelle Mendenhall May 2009

Punta Toro Virus Infection In Mice: Strain Differences In Pathogenesis And Regulation Of Interferon Response Pathways, Michelle Mendenhall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Adames strain of Punta Toro virus (PTV-A) causes acute hepatic disease in hamsters and mice similar to that seen in natural Rift Valley fever virus (RVFV) infection, while the Balliet strain (PTV-B) is apathogenic. The ability of PTV-A to suppress the interferon (IFN) response has been demonstrated in hamsters and is thought to be a contributing factor to PTV-A's pathogenicity in hamsters. PTV-B is not assumed to exhibit this IFN-antagonistic activity, as it stimulates production of significantly higher IFN-β levels. To elucidate the role of IFN in resistance of mice to PTV-B infection, we utilized mice deficient in a …


Patterns Of Learning Object Reuse In The Connexions Repository, S. M. Duncan May 2009

Patterns Of Learning Object Reuse In The Connexions Repository, S. M. Duncan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since the term learning object was first published, there has been either an explicit or implicit expectation of reuse. There has also been a lot of speculation about why learning objects are, or are not, reused. This study quantitatively examined the actual amount and type of learning object use, to include reuse, modification, and translation, within a single open educational resource repository–Connexions. The results indicate that about a quarter of used objects are subsequently reused, modified, or translated. While these results are repository specific, they represent an important first step in providing an empirical evaluation of the frequency and some …


The Relationship Between Education About Dress Practices And Change In Perception Of Self-Concept Related To Dress, Jennifer L. Nielson May 2009

The Relationship Between Education About Dress Practices And Change In Perception Of Self-Concept Related To Dress, Jennifer L. Nielson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The influence of an individual's dress practices on his/her sense of self has been studied for many years. Courses such as the Dress and Humanity course at Utah State University have been developed to educate students on the impact of dress on society. In this study, students in the Dress and Humanity course were given a pre-course and post-course survey to determine if self-perceptions related to dress practices underwent a change over the duration of the semester. Significant differences were found in the categories of body image, evaluating self-esteem, and communication of self to others. A relationship was found between …


The Regulation Of Epithelial Sodium Channels In Mammalian Taste Receptor Cells, Arian F. Baquero Gonzalez May 2009

The Regulation Of Epithelial Sodium Channels In Mammalian Taste Receptor Cells, Arian F. Baquero Gonzalez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrient recognition is one of the main physiological roles of the gustatory system. In mammals, it is well established that the taste of sodium salts is primarily mediated by sodium influx through the epithelial sodium channel. The epithelial sodium channel is a sodium-specific ion channel that is expressed across a wide range of transporting epithelia such as colon, kidney, and taste. In addition to its role as a salt taste receptor, sodium influx through the epithelial sodium channel is important systemically for maintaining sodium balance and blood pressure. Following our earlier work on the endocrine regulation of salt taste at …


Targeting Fat-Sensitive Pathways In Enteroendocrine Cells Using Nanoparticle-Mediated Drug Delivery, Bhavik P. Shah May 2009

Targeting Fat-Sensitive Pathways In Enteroendocrine Cells Using Nanoparticle-Mediated Drug Delivery, Bhavik P. Shah

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The current epidemic of obesity has been linked to an increase in fat intake associated with the Western diet. Nutrient-induced stimulation of enteroendocrine cells in the small intestine leads to the release of hormones that contribute to satiety and the control of food intake. In particular, ingested fat, specifically in the form of free fatty acids, is potent activator of enteroendocrine cells in the proximal small intestine. However, the underlying signaling cascade that free fatty acids initiate in these enteroendocrine cells, which leads to secretion of satiety hormones, is not known. In general, my research is focused on identifying nutrient-responsive …


Inducing A Normal Phenotype In Breast Epithelial Cells Using A Three-Dimensional Basement Membrane Extract Culture System: A Study On The Reversion Of Cancer, Ross H. Booth May 2009

Inducing A Normal Phenotype In Breast Epithelial Cells Using A Three-Dimensional Basement Membrane Extract Culture System: A Study On The Reversion Of Cancer, Ross H. Booth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Experimentally, traditional developmental models and transgenic animals consistently underscore the importance of studying cell behavior in the correct tissue context. However, live animal experimentation is inherently complex, and systematic assessment of the effects of individual variables, such as cell shape and matrix compliance on cell behavior, is extremely difficult at best. Two-dimensional monolayer culture of key individual cell types has provided abundant, fundamental information on cell response, but cannot be used to show the normal phenotype of breast epithelial cells. Furthermore, their results often fail to translate into in vivo and clinical studies. It has been previously established that normal …


Comparison Of Data Collection And Methods For The Approximation Of Streambed Thermal Properties, Jonathan D. Bingham May 2009

Comparison Of Data Collection And Methods For The Approximation Of Streambed Thermal Properties, Jonathan D. Bingham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When approximating heat transfer through a streambed, an understanding of the thermal properties of the sediments is essential (e.g., thermal conductivity, specific heat capacity, and density). Even though considerable research has been completed in this field, little has been done to establish appropriate standard data collection approaches or to compare modeling methods for approximating these properties. Three mixture models were selected for comparison against each other and against a bed conduction model (SEDMOD). Typical data collection approaches were implemented for use in the mixture models while numerous data collection approaches were employed for use within SEDMOD. Sediment samples were taken …


The Use Of Reverse Genetics To Clone And Rescue Infectious, Recombinant Human Parainfluenza Type 3 Viruses, Jason Peter Roth May 2009

The Use Of Reverse Genetics To Clone And Rescue Infectious, Recombinant Human Parainfluenza Type 3 Viruses, Jason Peter Roth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Reverse genetics is a discipline that involves the use of genetic manipulation and modification to study an organism's altered phenotype. In this study, infectious recombinant viruses were rescued from altered cDNA clones encoding the antigenome of human parainfluenza virus type 3 and the resulting phenotypes were examined. In one clone, the gene for the enhanced green fluorescent protein was inserted into the virus antigenome to be expressed during viral replication, resulting in infected cells emitting green fluorescence. Viral titers, mRNA replication, and genomic replication for the virus expressing the enhanced green fluorescent protein were reduced when compared to the human …


Status And Slaughter: The Psycho-Social Factors That Influence Public Mass Murder, Stephen G. Van Geem May 2009

Status And Slaughter: The Psycho-Social Factors That Influence Public Mass Murder, Stephen G. Van Geem

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Even though public mass shootings are relatively rare, they represent an atypical form of violence that is both sudden and yields an unprecedented amount of carnage; for these reasons, an inordinate amount of scholarship has been produced in order to isolate both the causes and effects of these rampages. As there is no clear cut and universal cause, over the past forty years numerous factors have been offered to account for these types of shootings, including bullying, peer relations, family problems, cultural conflict, demographic change, mental illness, gun culture, copycatting, and the media. While there appears to be an element …


Greater Sage-Grouse And Energy Development In Northeastern Utah: Implications For Management, Leah Suzanne Smith May 2009

Greater Sage-Grouse And Energy Development In Northeastern Utah: Implications For Management, Leah Suzanne Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Concern regarding the effect of energy development on greater sage-grouse (Centrocercus urophasianus) is increasing as the search for fossil fuel intensifies. Sage-grouse may be especially sensitive to energy development because they require large, diverse areas of sagebrush (Artemisia spp.) habitat to complete their life cycle. Additionally, the network of pipelines, roads, and wells required by energy development may fragment sagebrush habitat isolating populations and contributing to genetic drift, inbreeding, local extinction, or rapid divergence.

Seep Ridge, located in northeastern Utah, is one area where sage-grouse habitat and energy development plans overlap. Approved leases call for the construction …


The Development Of Context-Specific Operant Sensitization To D-Amphetamine, Wesley Paul Thomas May 2009

The Development Of Context-Specific Operant Sensitization To D-Amphetamine, Wesley Paul Thomas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animal models have previously been used to study tolerance and sensitization using two different procedures that are difficult to compare. Tolerance has been studied by administering a drug to a subject that is engaged in an operant behavior, and sensitization by administering a drug to a subject that is not engaged in an operant behavior. Previous research has shown that sensitization can occur when d-amphetamine is administered to rats emitting an operant behavior for a food presentation. The first goal of the experiment was to show operant sensitization using dose response curves. The second goal of the present experiment was …


Maintaining Population Persistence In The Face Of An Extremely Altered Hydrograph: Implications For Three Sensitive Fishes In A Tributary Of The Green River, Utah, Jared L. Bottcher May 2009

Maintaining Population Persistence In The Face Of An Extremely Altered Hydrograph: Implications For Three Sensitive Fishes In A Tributary Of The Green River, Utah, Jared L. Bottcher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The ability of an organism to disperse to suitable habitats, especially in modified and fragmented systems, determines individual fitness and overall population viability. The bluehead sucker (Catostomus discobolus), flannelmouth sucker (Catostomus latipinnis), and roundtail chub (Gila robusta) are three species native to the upper Colorado River Basin that now occupy only 50% of their historic range. Despite these distributional declines, populations of all three species are present in the San Rafael River, a highly regulated tributary of the Green River, Utah, providing an opportunity for research. Our goal was to determine the timing and …


Application Of Electrified Fladry To Decrease Risk Of Livestock Depredation By Wolves (Canis Lupus), Nathan J. Lance May 2009

Application Of Electrified Fladry To Decrease Risk Of Livestock Depredation By Wolves (Canis Lupus), Nathan J. Lance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wolf (Canis lupus) predation on livestock can cause economic and emotional hardships for livestock producers, complicating the balance of wolf conservation with other human interests. New management tools that decrease risk of predation may offer additional flexibility or efficiency for both livestock producers and management agencies. I examined 1) the efficacy of electrified fladry compared to fladry at protecting a food source from wolves in captivity, 2) the efficacy of electrified fladry for reducing wolf use of pastures and preventing depredations, and 3) the applicability of electrified-fladry. In captivity I tested the reaction from 15 groups (46 wolves) …


Evaluation Of Macroinvertebrates As A Food Resource In The Assessment Of Lotic Salmonid Habitat, Nicholas P. Weber May 2009

Evaluation Of Macroinvertebrates As A Food Resource In The Assessment Of Lotic Salmonid Habitat, Nicholas P. Weber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Criteria used to characterize lotic salmonid habitat are often based on observed correlations between physical habitat characteristics and salmonid abundances. A focus on physical habitat features ignores other habitat components, such as an adequate supply of food that set the physiological limitations on salmonid growth and survival. This study outlines the development of a habitat assessment approach that focuses on how invertebrate food availability interacts with stream temperatures to determine salmonid growth potentials. Abundances of benthic and drifting invertebrate communities, stream temperatures, and juvenile steelhead trout (Onchorhynchus mykiss gairdneri) summer growth rates and abundances were measured within 10 …


Biological And Economic Effects Of Grazing Spring-Calving Cow-Calf Pairs On Improved Irrigated Pastures Using Creep Supplementation, Adam F. Summers May 2009

Biological And Economic Effects Of Grazing Spring-Calving Cow-Calf Pairs On Improved Irrigated Pastures Using Creep Supplementation, Adam F. Summers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent trends to develop farmland into improved irrigated pastures raise questions regarding the profitability of creep supplementing terminal-sired calves on these production systems. This study was initiated to answer these questions. Two previously established adjacent sprinkler-irrigated plots were separated into 2 paddocks. One plot (3.4 ha) consisted of a monoculture of Seine tall fescue while the other plot (3.9 ha) consisted of a mixture of Seine tall fescue, AC Grazeland Alfalfa, and Norcen birdsfoot trefoil. The mixture of the second plot consisted of 50% tall fescue, 37.5% alfalfa, and 12.5% birdsfoot trefoil. Plots were designated as monoculture no-creep supplement (MONOC) …


Production Performance And Profiles Of Milk Fatty Acids Of Lactating Dairy Cows Fed Whole Safflower Seed Containing High Fat And Low Fiber, Christopher M. Dschaak May 2009

Production Performance And Profiles Of Milk Fatty Acids Of Lactating Dairy Cows Fed Whole Safflower Seed Containing High Fat And Low Fiber, Christopher M. Dschaak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oil seeds are natural sources of fat and protein in diets for lactating cows, and are usually fed whole or crushed. A recently released variety of safflower seed, 'Nutrasaff,' contains high fat (47% crude fat) and low fiber (26% NDF), and has a potential to be effectively used as a fat supplement for lactating dairy cows. Therefore, a lactating dairy cow trial was conducted to assess production performance of dairy cows when fed graded levels of whole Nutrasaff safflower seed (NSS), to determine the optimum level of NSS supplementation in the diet and to identify its impact on milk fat …


Nitrogen And Phosphorus Dynamics As Applied To Water Quality Under Management Intensive Grazing, Vaughn J. Thacker May 2009

Nitrogen And Phosphorus Dynamics As Applied To Water Quality Under Management Intensive Grazing, Vaughn J. Thacker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Contamination of freshwater systems by nutrients has been studied extensively in the eastern U.S. Little research on the fate of nutrients in grazing conditions has been done in the western U.S. Western agriculture is often irrigated and research addressing the potential for leaching under these conditions is warranted. This study used Management Intensive Grazing (MIG) and eight grass-legume mixtures to evaluate the management and forage choice in relation to nitrogen and phosphorus leaching to ground water. Soil water samples were taken weekly through the growing season from 2001 through 2003. Water samples were analyzed for nitrate, ammonia, and phosphate. Soils …


Anti-Semitic Folklore Motif Index, Sita Bell May 2009

Anti-Semitic Folklore Motif Index, Sita Bell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Anti-Semitism, or Jew hatred, much of which is expressed and communicated through folklore, has a long history and continues unabated today. Incendiary opinions, deadly misconceptions, and insidious accusations have plagued Jews throughout history. Anti-Semitic expressions and incidents are scattered throughout countless texts, but no single comprehensive reference work that compiles all forms of anti-Semitic folklore motifs exists. This thesis attempts to fill that gap by supplying an index of anti-Semitic motifs.

To establish a baseline of already catalogued anti-Semitic motifs, all six volumes of Stith Thompson's Motif-Index of Folklore-Literature: A Classification of Narrative Elements in Folktales, Ballads, Myths, Fables, Mediaeval …


Surgical Sterilization Of Coyotes To Reduce Predation On Pronghorn Fawns, Renee Seidler May 2009

Surgical Sterilization Of Coyotes To Reduce Predation On Pronghorn Fawns, Renee Seidler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coyote (Canis latrans) predation accounts for the majority of neonatal pronghorn (Antilocapra americana) mortality in many areas and may influence local population declines. Current techniques used to manage coyote predation on wildlife species generally focus on lethal control methods. However, these methods may be controversial to the general public. Coyote sterilization is an alternative predation control method which is more acceptable to the public and has been shown to be effective in reducing sheep predation. We hypothesized that surgical sterilization of coyotes may increase pronghorn fawn survival; in the same way it reduces coyote predation on …


Characterization Of The Substrate Specificity And Mechanism Of Protein Arginine Methyltransferase 1, Whitney Lyn Wooderchak May 2009

Characterization Of The Substrate Specificity And Mechanism Of Protein Arginine Methyltransferase 1, Whitney Lyn Wooderchak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Protein arginine methyltransferases (PRMTs) posttranslationally modify protein arginine residues. Type I PRMTs catalyze the formation of monomethylarginine (MMA) and asymmetric dimethylarginine (ADMA) via methyl group transfer from S-adenosyl methionine onto protein arginine residues. Type II PRMTs generate MMA and symmetric dimethylarginine. PRMT-methylation affects many biological processes. Although PRMTs are vital to normal development and function, PRMT-methylation is also linked to cardiovascular disease, stroke, multiple sclerosis, and cancer.

Thus far, nine human PRMT isoforms have been identified with orthologues present in yeast, plants, and fish. PRMT1 predominates, performing an estimated 85% of all protein arginine methylation in vivo. Yet, the substrate …


River Network Structure: A Template For Understanding Predator-Prey Dynamics And Potential Anthropogenic Impacts, Catherine L. Hein May 2009

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 …


Terrestrial Small Mammals From The Gamba Complex In Gabon: Distribution Patterns And Landscape Influences, Carrie J. O'Brien May 2009

Terrestrial Small Mammals From The Gamba Complex In Gabon: Distribution Patterns And Landscape Influences, Carrie J. O'Brien

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The small mammal communities of central Africa are not well understood, and the southwestern section of Gabon has not been previously surveyed except for some recent work in Monts Doudou. At five sites within the Gamba Complex we set out to 1) document the species of terrestrial rodents (Muridae) and shrews (Soricidae) weighing less than 100 g, 2) compare the community composition between inland and coastal sites, and 3) evaluate our sampling protocols. Using a combination of pitfall lines, Sherman live traps, and snap traps we captured 721 individuals of 12 rodent and 10 shrew species in 15,792 trap-nights. The …


Greater Sage-Grouse Ecology, Chick Survival, And Population Dynamics, Parker Mountain, Utah, David K. Dahlgren May 2009

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 …


Predation On Domestic Sheep On Summer Range Lands In Southwestern Utah, Brian Carl Palmer May 2009

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 …


Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie May 2009

Soil Organic Carbon And Site Characteristics In Aspen And Evaluation Of The Potential Effects Of Conifer Encroachment On Soil Properties In Northern Utah, Mical K. Woldeselassie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the Intermountain West, aspen (Populus tremuloides) has declined mainly due to a combination of successional processes, fire suppression and long-term use of ungulates which has led to replacement by conifers, sagebrush or other shrub communities. Conifer encroachment is believed to cause critical changes in the ecosystem properties. In order to understand the impacts of conifer encroachment on soil properties such as soil organic carbon (SOC) storage, soil morphology, and soil chemical properties, and the implications of such changes, it is very important to assess the soil properties under the two vegetation types. The objectives of this study …


Detecting Organic Molecules On The Surface Of Inorganic Dust Particles Using Aerosol Mass Spectrometry, Sileola B. Akinsiku May 2009

Detecting Organic Molecules On The Surface Of Inorganic Dust Particles Using Aerosol Mass Spectrometry, Sileola B. Akinsiku

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detection of organic molecules present on the surface of dust particles is important in homeland security, agriculture, and several other applications. The research presented reports the ability of the aerosol mass spectrometer (AMS) to detect molecules on the surface of dust particles without detecting the particle core.

Experiments were carried out to detect semi-volatile organic compounds adsorbed onto the surface of particulates without interference from the dust particle core. Methyl salicylate, oleic acid, and organophosphorus pesticides such as Malathion were detected on the surface of particles representative of dust-type materials. Zeolite powders were used as aerosol support, representative of a …