Life Sciences Commons^™

Vegetation Characteristics Of Wyoming Big Sagebrush Communities Historically Seeded With Crested Wheatgrass In Northeastern Great Basin, Usa, Justin Rodney Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded grass species in the western United States and dominates thousands of hectares in the Great Basin. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass, successional pathways, influence of soil attributes, and cultivation history on the vegetation of these communities have not been fully characterized. I sought to identify community phases, vegetative differences, and soil attributes that explain variation among 35 Wyoming big sagebrush communities historically seeded with crested wheatgrass. All communities were more than …

A Comparative Study Of The Structural Features And Kinetic Properties Of The Mofe And Vfe Proteins From Azotobacter Vinelandii, Miguel Alejandro Pabon Sanclemente

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological nitrogen fixation is accomplished in the bacterium Azotobacter vinelandii by means of three metalloenzymes: The molybdenum, vanadium, and iron-only nitrogenase. The knowledge regarding biological nitrogen fixation has come from studies on the Mo-dependent reaction. However, the V- and Fe-only-dependent reduction of nitrogen remains largely unknown.

By using homology modeling techniques, the protein folds that contain the metal cluster active sites for the V- and Fe-only nitrogenases were constructed. The models uncovered similarities and differences existing among the nitrogenases regarding the identity of the amino acid residues lining pivotal structural features for the correct functioning of the proteins. These differences, …

An Investigation Of Postzygotic Reproductive Isolation And Phenotypic Divergence In The Bark Beetle Dendroctonus Ponderosae, Ryan R. Bracewell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding reproductive isolation and divergence is the focus of speciation research. Recent evidence suggested that some Dendroctonus ponderosae populations produced hybrids with reproductive incompatibilities, a reproductive boundary undetected by phylogeographic analyses using molecular markers. Additionally, the unique bifurcated distribution of D. ponderosae and the proposed isolation-by-distance gene flow pattern around the Great Basin Desert provided a unique opportunity to investigate the evolution of postmating (postyzygotic) isolation while also understanding phenotypic divergence along latitudinal (climatic) gradients. First, I characterized the strength, biological pattern, and geographic pattern of postzygotic isolation in D. ponderosae by crossing increasingly divergent populations in a common garden …

The Bioactive Properties Of Syringomycin E-Rhamnolipid Mixtures And Syringopeptins, Mekki F. Bensaci

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The need for new antimicrobial agents has become important in the last decade due to emerging resistance to a number of conventional antimicrobial agents. New approaches and sources are needed to generate novel and effective antimicrobials. For example, synergistic combinations between two or more agents may lead to new antimicrobial therapies. Furthermore, the increase in health problems caused by the exposure to agricultural crop pesticides and synthetic fungicides and the emerging development of organic farming has increased the necessity to develop natural products than can be used safely in controlling crop diseases.

In this work, I present the first studies …

Mechanisms Of Induced Cell Death In Bluetongue Virus Challenged Human Cell Lines, Justin Darrel Hoopes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bluetongue virus (BTV) is a pathogenic member of the Reoviridae family. BTV does not cause disease in humans, but is capable of selectively infecting and killing certain transformed human cell lines. Understanding BTV's oncotrophism may lead to new therapeutics for treating cancer. This study focused on the underlying mechanisms of BTV-induced cell death in carcinoma cell lines. It was our hypothesis that BTV infects human carcinoma transformed cells, produces mRNA and protein, induces a strong inflammatory response, induces mitogen activated protein kinase (MAPK)-based pro-apoptotic signaling, inhibits PKB-based signaling, and eventually kills the cell by inducing apoptosis.

Three carcinoma cell lines …

Taste Sensitivity To 6-N-Propylthiouracil (Prop) As A Biological Marker For Vulnerability To Stress In Mothers And Children, Deann Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Some people are genetically more vulnerable to stress than others, leading them towards poorer outcomes following stressful events. Mothers' vulnerability to stress may, in turn, influence their children, leading their children towards poor outcomes as well. A biological marker of vulnerability to stress may indicate mothers who are at greater risk for experiencing parenting stress, depression, and less support of the infant's emotional development, and infants who are at greater risk for development of poor emotion regulation and behavior problems. Taste sensitivity to propylthiouracil (PROP) is proposed as a biological marker of stress vulnerability in mothers and children. This research …

Microbial Growth Inhibition And Decomposition Of Milk Mineral And Sodium Tripolyphosphate Added To Media Or Fresh Ground Beef, Rossarin Tansawat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Milk mineral (MM) is a type II antioxidant (metal chelator) that can bind iron and prevent iron catalysis of lipid oxidation. Thus, MM might have microbial growth inhibition effects on iron-dependent bacteria. Objective 1 was to evaluate effects of MM on growth of non-pathogenic iron-dependent bacterial strains (Listeria innocua, Eschericia coli, Pseudomonas fluorescens). MM (1.5 % w/v) did not significantly inhibit growth of Listeria and E. coli. However, growth of Pseudomonas fluorescens was consistently and significantly reduced by ~1 log colony forming units per ml (CFU/ml) with all levels of MM (0.5, 0.75, 1.5 % …

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

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 …

Speciation, Species Concepts, And Biogeography Illustrated By A Buckwheat Complex (Eriogonum Corymbosum), Mark W. Ellis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The focus of this research project is the complex of infraspecific taxa that make up the crisp-leaf buckwheat species Eriogonum corymbosum (Polygonaceae), which is distributed widely across southwestern North America. This complex provides an ideal taxonomic group for research into population relationships and speciation. To avoid unnecessary debates about taxonomic validity or contentious issues regarding appropriate species definitions, the historical evolution of the species concept is first reviewed in detail, demythologizing an often-assumed species problem. Following that review, the E. corymbosum complex is examined specifically.

Although eight varieties of E. corymbosum are currently recognized based on morphological characters, this group …

Design And Evaluation Of Oligonucleotide Microarrays For The Detection Of Bovine Pathogens, Ryan Weldon Black

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two microarray designs were developed and produced to screen for multiple bovine pathogens commonly found in the cattle industry today. The first microarray was designed, built, and processed in-house using conventional material and equipment and targeted Pasteurella multocida, Manheimia haemolytica, Histophilus somni, and Arcanobacterium pyogenes. For each pathogen, 12 perfect-match oligonucleotide probes, which were also designed in-house, targeted different sections of the respective 16S ribosomal genes, and were coupled with 12 corresponding mismatched probes for background. These arrays were able to produce distinct hybridization patterns for each pathogen that were easily visible without the need for …

Validation Of A Peer-Teaching-Peer Paraprofessional Model In Teen Parenting Nutrition Education, Sylvia D. Keller

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Each year, teen pregnancy occurs in 750,000 15-to-19 year-old women in the United States (U.S.). Utah has the youngest population and the lowest teen abortion rates in the U.S. Approximately 73% of teen pregnancies in Utah result in live births. The prevalence of teen pregnancy and the nutritional risk to mother and child result in a much greater need for social support, such as nutrition education. Current literature shows that the paraprofessional model is effective in increasing positive behavior change through nutrition education. Presently, there is a lack of evidence that paraprofessional teens are capable of accurately and effectively teaching …

Mycorrhizae In Sagebrush-Steppe Community Restoration: Mycorrhizal Dependency Of Invasive And Native Grasses With Intraspecific And Interspecific Competition, Dara S. Scherpenisse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mycorrhizae have been used in restoration for decades. However, studies assessing the use of mycorrhizae in Bromus tectorum-invaded areas of the Great Basin are limited. Two greenhouse pot experiments were conducted to assess the role of mycorrhizae in sagebrush restoration.

The first objective (Chapter 2) was to determine the response of Pseudoroegneria spicatum, Elymus elymoides, and B. tectorum to mycorrhizal symbiosis by altering phosphorus, density, species, presence of mycorrhizae and water levels in a 5 factor design. To assess the mycorrhizal response, a variety of morphological and physiological traits were measured, such as tissue P concentration, specific …

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

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

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 …

Naive Prey Versus Nonnative Predators: A Role For Behavior In Endangered Species Conservation, Stephanie A. Kraft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fish are one of the most imperiled groups of vertebrates worldwide. Threats to fish fall into one of four general categories: physical habitat loss or degradation, chemical pollution, overfishing, and nonnative species introductions. Nonnative predatory fish often have a devastating impact on native prey, especially with endemic fish, whose restricted distribution and often limited evolutionary history with predators make them particularly susceptible to nonnative predators. One reason nonnative fish are often so efficient predators is that the native fish do not recognize the predator as a threat. Although many studies have examined the role of predator odor recognition, no fish …

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 …

Effects Of Olfactory And Visual Predators On Nest Success And Nest-Site Selection Of Waterfowl In North Dakota., Jennifer S. Borgo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Selecting a nest site is an important decision for waterfowl. Because most nest failure is due to depredation, the primary selective pressure in choosing a nest site should be to reduce depredation risk. This task is difficult because predators use differing tactics to locate nests, such as olfactory or visual cues. I investigated several components of waterfowl nest-site selection and success on sites with shelterbelts (planted tree-rows) in North Dakota, during the 2006 and 2007 nesting seasons.

I found that meteorological conditions impacted nest depredation; artificial nests were more likely to be depredated when either temperature or dew point was …

Predator-Prey Relationships And Spatial Ecology Of Jaguars In The Southern Pantanal, Brazil: Implications For Conservation And Management, Sandra Maria Cintra Cavalcanti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Pantanal wetland of Brazil is an important area for the conservation of jaguars (Panthera onca) and a stronghold for the species. Although our knowledge of jaguar ecology has increased since the first field studies in the mid 1980’s, a detailed study of this cryptic species remains challenging. In the following chapters, we investigated the ecology of jaguars in the southern Pantanal of Brazil. In Chapter II, we examined the foraging ecology of jaguars, documenting predation rates, patterns, and species killed. We found individual jaguars differed in the selection of their prey. There were differences in the proportion …

Aminoglycosides And Syringomycin E As Fungicides Against Fusarium Graminearum In Head Blight Disease, Yukie Kawasaki

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fusarium graminearum is one of the most problematic phytopathogens in US agriculture. This fungus causes head blight, foot rot, and damping off on wheat and barley. The infection lowers the grain yield and causes contamination of the grain product with mycotoxins. Effective control measures are lacking, and new fungicides that kill F. graminearum but remain safe and economical to use are needed. Newly synthesized aminoglycosides (JL22, JL38, JL39, JL40, NEOF004, NEOF005), classic aminoglycosides (amikacin, gentamicin, kanamycin A, kanamycin B, neomycin, and ribostamycin), and a lipopeptide, syringomycin E (SRE), were studied to determine their antifungal potential to control F. graminearum. …

Estimating Total Phosphorus And Total Suspended Solids Loads From High Frequency Data, Amber Spackman Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Frequently measured turbidity was examined as a surrogate for total phosphorus (TP) and total suspended solids (TSS) loads at two locations in the Little Bear River, Utah, USA. Using regression techniques, equations were developed for TP and TSS as functions of turbidity. The equations accounted for censored data, and additional explanatory variables to represent hydrological conditions were considered for inclusion in the equations. By using the resulting surrogate relationships with high frequency turbidity measurements, high frequency estimates of TP and TSS concentrations were calculated. To examine the effect of sampling frequency, reference loads were determined from the concentration records for …

Livestock Mortality At Beef Farms With Chronic Wolf (Canis Lupus) Depredation In The Western Great Lakes Region (Wglr), Arion Vandergon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gray wolf (Canis lupus) depredation on beef calves has been studied extensively in recent years. As wolf populations increase throughout the United States there is a corresponding increase in wolf/livestock interactions. Most research concentrates on summaries of reported depredations and surveys of producers affected by depredations. The objective of this study was to present data on the fate of beef calves on 3 farms in Minnesota and Wisconsin over a 2-year period. Predator presence/absence was studied as an indicator of potential depredations. Also, data are presented comparing 2 techniques that may aid researchers and livestock producers with monitoring …

Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …

Evaluation Of An Interactive Health Communication Trans Fat Website, Tara Banks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to evaluate the short-term educational and behavioral impact of the American Heart Association's "Face the Fats" web application had upon college students, a study involving 116 Utah State University undergraduate students was conducted. A one-group pre-posttest design was utilized to answer eight research questions focusing on: health risks associated with trans fat, general trans fat knowledge, ability to identify foods containing trans and saturated fats, food label information, healthy alternatives to trans fat, and readiness to change trans fat intake. Participants completed an online pretest survey and then viewed the "Face the Fats" website at their own pace. …

Influence Of Supplemental Legumes That Contain Tannins And Saponins On Intake And Diet Digestibility In Sheep Fed Grasses That Contain Alkaloids, Jacob Michael Owens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

My objectives were to determine if nutritional benefits occur when animals are offered foods with compounds -- alkaloids, saponins, and tannins - that are potentially complementary. I hypothesized that food intake and digestibility increase when lambs consume plants such as alfalfa ALF that contain saponins or birdsfoot trefoil (BFT) that contain tannins when the basal diet is endophyte-infected tall fescue (TF) or reed canarygrass (RCG) both of which contain alkaloids. I predicted that the nutritional status of lambs would be enhanced if basal diets of alkaloid-containing grasses were supplemented with ALF or BFT.

Lambs fed a basal diet of either …

Enhancing The Proportions Of Healthy Fatty Acids In Milk From Dairy Cows, Korie A.S. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Twenty cows were used in a repeated measures, block design experiment for 9 wk to determine the effects of feeding partially ruminally inert calcium salts (Ca-salts) of fish oil (FO) and a general fatty acid (FA) supplement (EnerGII) at varying levels. The effects on cow health, milk components, composition of milk FA, and sensory evaluation of milk were evaluated. Cows in the 4 treatments were fed either a control diet of 57% forage and 43% concentrate mix with EnerGII fat supplement at 1.65% of diet DM (CTL) or EnerGII in basal diet was partially replaced with (a) 0.21% …

Movement Patterns And Multi-Scale Factors That Influence Exotic Brook Trout And Endemic Bonneville Cutthroat Trout Distribution And Abundance In The Mill Creek Drainage, Utah, Benjamin Keith Nadolski

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Introduced brook trout (Salvelinus fontinalis) are implicated as a primary factor leading to the decline in distribution and abundance of native cutthroat trout (Oncorhynchus clarkii). However, not all introductions are successful, suggesting local conditions influence the success of invasions. Therefore, I sought to determine the multi-scale factor(s) that influence brook trouts’ invasion success of native Bonneville cutthroat trout (Oncorhynchus clarkii utah) habitats in Mill Creek, Utah. I conducted patch occupancy surveys to determine watershed-scale brook trout and cutthroat trout distribution. I also determined the relative abundance of brook trout and cutthroat trout at the …

Growing Wild: Crested Wheatgrass And The Landscape Of Belonging, Lafe Gerald Conner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass arrived in North America at the turn of the twentieth century through the foreign plant exploration missions sponsored by the United States Department of Agriculture. During the first two decades of the new century, scientists tested the grass at agricultural experiment stations. They determined it was useful for grazing and particularly valuable because it could grow in drought conditions with little or no care and would continue to produce high quality feed even after several years of heavy use. Beginning in the 1930s federally sponsored land utilization and agricultural adjustment programs sponsored the use of crested wheatgrass for …

Mountain Pine Beetle Fecundity And Offspring Size Differ Among Lodgepole Pine And Whitebark Pine Hosts, Donovan Gross

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Whitebark pine (Pinus albicaulis Engelmann) is a treeline species in the central Rocky Mountains. Its occupation of high elevations previously protected whitebark pine from long-term mountain pine beetle outbreaks. The mountain pine beetle, however, is currently reaching outbreaks of record magnitude in high-elevation whitebark pine. We used a factorial laboratory experiment to compare mountain pine beetle (Dendroctonus ponderosae Hopkins) life history characteristics between a typical host, lodgepole pine (Pinus contorta Engelmann), and whitebark pine. We tested the effects of natal host and brood host on beetle fecundity, offspring size, and brood sex-ratio. We reared mountain pine beetles …