Life Sciences Commons^™

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 …

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 …

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. …

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 …

Effects Of Starch Addition On Low Fat Rennet Curd Properties And Their Partitioning Between Curd And Whey, Kelly Marie Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study determined the impact of starches on the properties of low fat rennet curd as measured by microstructural and instrumental analysis. In experiment 1, 17 starches were initially screened for swelling power, impact of curd yield at 5 g/L and 10 g/L in milk, and settling in rennet-induced partially acidified low fat curd.

Starches examined were narrowed down to five in experiment 2; they included: modified waxy corn starch, waxy rice starch, instant tapioca starch, dextrin, and a modified tapioca starch. These starches were added to skim milk to make rennet-induced partially acidified milk gels. Gels were made by …

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 …

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 …

Disturbance Ecology And Vegetation Dynamics At Varying Spatial And Temporal Scales In Southern Rocky Mountain Engelmann Spruce Forests, R. Justin Derose

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

High-severity disturbances are the primary drivers of Engelmann spruce-subalpine fir ecosystems in the southern Rocky Mountain. Recently, an unprecedented, landscape-wide (at least 250 km2) spruce beetle outbreak killed virtually all the Engelmann spruce on the Markagunt Plateau in southwestern Utah, USA. Results from dendroecological analyses suggested the combination of antecedent disturbance history and drought-driven stand development was responsible for creating suitable host conditions prior to the recent outbreak. Multiple and consistent lines of evidence suggested mixed- and high-severity fires shaped the development of the Markagunt Plateau. Subsequent stand development, influenced by species-specific differential tree-ring response to drought, resulted in the …

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 …

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). …

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 …

Isolation And Characterization Of Different Aggregates Of Lipid From Bovine Milk, Ankur Jhanwar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bovine milk fat globules naturally vary from less than 0.2 µm to 15 µm in diameter. Milk has at least two distinct distributions of fat globules. While the majority (~90%) of globules in milk are of the smaller distribution (average diameter of 0.4 µm), virtually all the fat is carried in the larger globules (average diameter 3.5 µm). This distribution suggests some compositional and/or functional significance might exist between the two populations of fat globules, which may be related to origin of these globules in the lactating cell.

Milk fat globules have a unique structure, composed of a core droplet …

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, …

Goatsrue (Galega Officinalis) Seed Biology, Control, And Toxicity, Michelle Oldham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Goatsrue is an introduced perennial plant that has proven to have great invasive potential, leading to its classification as a noxious weed in many states and at the federal level. This research focused on seed biology, herbicide control, and toxic dynamics of goatsrue. Physical dormancy of mature goatsrue seed was tested through scarification using sulfuric acid with exposures of up to 60 minutes resulting in 100% germination. Comparison of dormancy for 26-year-old and 6-month-old goatsrue seed indicated aged seeds had reduced dormancy levels compared to newly harvested seeds, but had similar viability. Goatsrue seedling emergence was inversely related to burial …

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 …

Cognitive Inference And Resulting Behaviors In Response To Ambiguous Threat In The Coyote, Canis Latrans, Sarah Shawnee Dawson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

While antipredator strategies have been a focus of behavioral research for decades, scientists generally study the responses of prey toward overt, explicit threat. However, risk can also be significant when a threat is covert, such as when an ambush predator may be nearby or a secondary threat remains after a predator's departure. Little is known about the mechanism that prey use to assess risk in a predator's absence. Tests were conducted to determine the manner in which coyotes respond to these ambiguous threats. Specifically, I tested whether coyotes respond to prior anthropogenic activity that has occurred near their only food …

Seed Banks Of Sagebrush Communities Seeded With Crested Wheatgrass, Kevin L. Gunnell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Crested wheatgrass (Agropyron cristatum [L.] Gaertn.) is one of the most commonly seeded exotic species in the western United States. Although many degraded Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) plant communities have been seeded with crested wheatgrass during rehabilitation efforts, seed banks of these communities have not been characterized. I sought to characterize and explain the variation among 33 seeded communities in the northeastern Great Basin. Hierarchical clustering and principal components analysis identified four possible seed bank categories in these communities. Seed bank categories varied from high to low crested wheatgrass dominance. The crested wheatgrass-dominated category …

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 …

Effects Of Targeted Grazing And Prescribed Burning On Fire Behavior And Community Dynamics Of A Cheatgrass (Bromus Tectorum)-Dominated Landscape, Joel M. Diamond

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies were conducted to determine the effectiveness of using targeted grazing and prescribed burning as tools to reduce fire hazards and cheatgrass (Bromus tectorum) dominance on rangelands in the northern Great Basin. A field study, with four grazing-burning treatments (graze and no-burn, graze and burn, no-graze and burn, and no-graze and no-burn), was conducted on a B. tectorum-dominated site near McDermitt, Nevada from 2005-2007. Cattle removed 80-90% of standing biomass in grazed plots in May 2005 and 2006 when B. tectorum was in the boot (phenological) stage. Grazed and ungrazed plots were burned in October 2005 and …

Predicting The Growth Potential Of A Shallow, Warm-Water Sport Fishery: A Spatially Explicit Bioenergetics Approach, Samuel Kirk Dahle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Capturing the range of fish consumption and growth potential of large, heterogeneous lentic systems can be challenging due to strong gradients in productivity, the diversity of habits types present, and in some cases, site-specific water quality issues. Cutler Reservoir (Utah, USA) displays a high degree of spatial and temporal variation in physical conditions and potential water quality limitations for fish, including high summertime water temperature and large, diel fluctuations in dissolved oxygen concentrations. The combination of bioenergetics modeling and GIS spatial analysis offers a promising interface for quantifying the fish consumptive and growth potential across a spatially and temporally heterogeneous …

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) …

Social Acceptability Of Conifer Control And Sagebrush Restoration In The Northern Rocky Mountain Region, Cameron G. Nay

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the past two centuries, woody plant species have increased in density and extent throughout the rangelands of North America. This encroachment generally has undesirable effects on hydrological function, forest resources, and plant community composition. Encroachment of Douglas-fir (Pseudotsuga menziesii) and ponderosa pine (Pinus ponderosa) into sagebrush communities is occurring in the Northern Rocky Mountain region. Removal and restoration treatments are often proposed to manage this issue, mainly prescribed fire, mechanical destruction, and/or herbicide use. Several contextual factors may affect public level of acceptability for such treatments. The issue frames used to present this problem to …

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 …

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 …

Prediction Of Protein Function And Functional Sites From Protein Sequences, Jing Hu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

High-throughput genomics projects have resulted in a rapid accumulation of protein sequences. Therefore, computational methods that can predict protein functions and functional sites efficiently and accurately are in high demand. In addition, prediction methods utilizing only sequence information are of particular interest because for most proteins, 3-dimensional structures are not available. However, there are several key challenges in developing methods for predicting protein function and functional sites. These challenges include the following: the construction of representative datasets to train and evaluate the method, the collection of features related to the protein functions, the selection of the most useful features, and …

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 % …

Evolutionary Consequences Of The Introduction Of Eleutherodactylus Coqui To Hawaii, Eric Michael O'Neill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The introduction of a species to areas outside its native range can result in ecological and genetic changes of evolutionary significance. The frog Eleutherodactylus coqui was introduced to Hawaii, from Puerto Rico, in the late 1980s and has lost genetic variation in mitochondrial DNA. The extent to which founder effects have influenced phenotypic variation in the introduced range is unknown. In this study I compared phenotypic variation in life-history traits, advertisement calls, and stripe patterns among introduced and native populations of the frog Eleutherodactylus coqui. I also conducted laboratory experiments to determine the influence of genetics and temperature on …