Life Sciences Commons^™

Native Bunchgrass And Invasive Weed Establishment In Low Nutrient Rangeland Soils With Nitrogen And Phosphorus Manipulation, Jeffrey S. Burnham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Competition between native perennial grasses and Bromus tectorum has been studied for many years. Recently, soil nutrients have been immobilized in an effort to preferentially inhibit growth of B. tectorum relative to native species. Most of this work has focused on soil N, but interactions with soil P are less studied and may be important as well. Additionally, although competitive effects and nutrient responses of several Centaurea spp. are well documented, data are lacking on the competitive effects that Centaurea virgata exerts on the establishment of native and exotic communities. A field experiment and a greenhouse experiment were conducted to …

Ecology And Management Of A High Elevation Southern Range Greater Sage-Grouse Population: Vegetation Manipulation, Early Chick Survival, And Hunter Motivations, Michael R. Guttery

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

My research provided new information concerning the management, ecology, and conservation of greater sage-grouse (Centrocercus urophasianus). I report the results of an experiment using strategic intensive sheep grazing to enhance the quality of greater sage-grouse brood-rearing habitat. Although forb cover, an important component of brood-rearing habitat, responded positively to the grazing treatment, the response of other habitat variables was suppressed because the plots were not protected from domestic and wild herbivores during the years following the treatments. Measurements taken in grazing exclosures confirmed that herbivory by both large and small animals had significant impacts on vegetation. However, despite …

Kinetic, Mechanistic, And Structural Investigation Of Features Controlling Stereoselectivity Of (R)- And (S)-Hydroxypropyl Com Dehydrogenases From Xanthobacter Autrophicus Strain Py2, Dariusz Adam Sliwa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enantiopure alcohols are valuable intermediates in fine organic synthesis, in particular for preparation of biologically active compounds. The necessity of preparing single enantiomer drugs in an optically pure form has triggered much research, especially in the pharmaceutical industry. The biocatalytical production of chiral alcohols by alcohol dehydrogenase enzymes is characterized by the asymmetric reduction of the corresponding ketones, usually with high degree of stereoselectivity. The commercial value of the enzymes as stereoselective biocatalysts has been a significant driving force in understanding features that control their mechanism of catalysis and stereoselectivity. This work focuses on two enantiocomplementary dehydrogenase enzymes ((R …

Selecting And Propagating Clones Of Bigtooth Maple (Acer Grandidentatum Nutt.), Melody Reed Richards

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Numerous wild bigtooth maple (Acer grandidentatum Nutt.) specimens in northern Utah have potential for use in landscapes, but improvements in selection and propagation need to be developed before these specimens can be introduced to the green industry. Criteria-based evaluations centered on aesthetics, function, and fall color were performed to objectively select superior bigtooth maple specimens. Out of 56 trees initially selected for red fall color, six were selected for propagation based on all three criteria. Five of the six selected trees yielded viable bud take via chip budding. Optimum time for chip budding propagation was determined by four experiments. …

Maporal Hantavirus Β-Integrin Utilization And Sensitivity To Favipiravir, Kristin K. Buys

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hantaviruses are members of the Bunyaviridae family of viruses. Pathogenic hantaviruses are the etiologic agents of hemorrhagic fever with renal syndrome (HFRS), a disease principally endemic in the Old World, and hantavirus pulmonary syndrome (HPS), a disease primarily restricted to the Americas. Maporal virus (MPRLV), a recently isolated hantavirus, has been found to cause disease in hamsters that resembles HPS in humans. However, the virus has not been linked to human cases of HPS. Considerable evidence suggests that β-integrin usage mediating infection may serve to distinguish hantaviruses pathogenic to humans from nonpathogenic, but this receptor usage pattern information is not …

An Investigation Of The Utilization Of Soil Water And Nitrogen Among Diverse Forage Plant Species And Mixtures, Sallee Reynolds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Species diversity achieved by adding novel functional groups (warm-season grasses and non-leguminous forbs) to pasture land, along with traditional grasses and legumes, could aid in the capture of nutrients and water in pasture systems by offering complementary rooting architecture to aid in water and nitrogen uptake and decrease nitrogen leaching. Because these species may differ from commonly used grasses and legumes in their seasonal pattern of productivity, they could also extend or enhance growing-season productivity. The goal of this project is to better understand the role of plant diversity in 1) nitrogen use and 2) distribution of rooting dynamics and …

Establishment And Aesthetic Value Of Native Grass, Legume, And Forb Species For Grassland Restoration In The Northern Intermountain West, Bridget M. Atkin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Interest in the restoration of landscapes native to the Intermountain West is growing as the value of these arid ecosystems is increasingly recognized. Many landscapes within the Intermountain region have been impacted by grazing, development, recreation, and other human-caused disturbances. The complex relationships within the native plant communities of these arid landscapes need to be well-understood biologically, while considering their aesthetic contribution, if restoration efforts are to succeed. Although the use of ecologically appropriate native species is increasing in popularity, there is discontinuity between aesthetics and meaningful ecological contributions. A series of studies was designed to aid in the restoration …

Pervasive Thermal Consequences Of Stream-Lake Interactions In Small Rocky Mountain Watersheds, Usa, Jessica D. Garrett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Limnologists and stream ecologists acknowledge the fundamental importance of temperature for regulating many ecological, biological, chemical, and physical processes. I investigated how water temperatures were affected by hydrologic linkages between streams and lakes at various positions along surface water networks throughout several headwater basins in the Sawtooth and White Cloud Mountains of Idaho (USA). Temperatures of streams and lakes were measured for up to 27 months in seven 6 – 41 km² watersheds, with a range of lake influence. When they were ice-free, warming in lakes resulted in dramatically warmer temperatures at lake outflows compared to inflow streams (midsummer …

The Status Of Dwarfed Populations Of Short-Horned Lizards (Phrynosoma Hernandesi) And Great Plains Toads (Anaxyrus Cognatus) In The San Luis Valley, Colorado, Megan E. Lahti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The San Luis Valley is a large valley formation in Colorado surrounded on either side by mountain ranges exceeding 4,267 m. Within the Valley, two of the 14 amphibian and reptile species are dwarfed: the short-horned lizard (Phrynosoma hernandesi) and the Great Plains toad (Anaxyrus cognatus). Since its initial reporting in 1968 and confirmation in 1981, no research further investigating this dwarfism has been conducted. I collected morphological measurements to determine the extent and patterns of dwarfism of both species. I then investigated the genetics of both species using mitochondrial DNA to determine whether they are …

Enhancing Out-Of-Season Production Of Tomatoes And Lettuce Using High Tunnels, Britney L. Hunter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The growing season for vegetable crops is limited by freezing temperatures in arid high elevation climates such as northern Utah. Logan, Utah (41.73 N, 111.83 W, 1382 m elevation) has a short, variable growing season with an average frost-free period of 135 days. Extending the growing season provides growers with an opportunity to extend revenue into a normally unproductive period and benefit from out-of-season price premiums. High tunnels have been used to effectively extend the growing season for numerous crops by providing cold temperature protection. However, limited high tunnel research has been performed in arid high elevation regions that experience …

Phenotypic And Genetic Characterization Of Wildland Collections Of Western And Searls Prairie Clovers For Rangeland Revegetation In The Western Usa, Kishor Bhattarai

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Western prairie clover [Dalea ornata (Douglas ex Hook.) Eaton & J. Wright] is a perennial legume that occurs in the northern Great Basin, Snake River Basin, and southern Columbia Plateau, whereas Searls prairie clover [Dalea searlsiae (A. Gray) Barneby], also a perennial legume, occurs in the southern Great Basin and surrounding areas. Understanding the genetic and ecotypic variation of these prairie clovers is a prerequisite for developing populations suitable for rangeland revegetation in the western USA. DNA sequences of internal transcribed spacer (ITS/5.8S) and trnK/matK were used to study the phylogeny of these species. The species were distinguished …

Dietary Milk Fat Globule Membrane Reduces The Incidence Of Aberrant Crypt Foci In Fischer-344 Rats And Provides Protections Against Gastrointestinal Stress In Mice Treated With Lipopolysaccharide, Dallin R. Snow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Milk fat globule membrane surrounds the fat droplets of milk. It is a biopolymer containing primarily membrane glycoproteins and polar lipids which contribute to its properties as a possible neutraceutical. The aims of the studies were to determine if dietary milk fat globule membrane: (1) confers protection against colon carcinogenesis; and (2) promotes gut mucosal integrity while decreasing inflammation compared to diets containing corn oil or anhydrous milk fat.

Aim 1. Three dietary treatments differing only in the fat source were formulated: (1) AIN-76A, corn oil; (2) AIN-76A, anhydrous milk fat; and (3) AIN-76A, 50% milk fat globule membrane, 50% …

Effect Of Mica Content On Surface Infiltration Of Soils In Northwestern Kern County, California, Steven Keyes Stakland

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A soils infiltration rate (IR) is the measured rate that soil is able to absorb water, either from precipitation or irrigation. A low IR can cause damage to crops if the necessary amount of water cannot penetrate to the plant roots in the time needed. The damage can be common in permanent plantings such as almond and pistachio orchards where regular tillage is avoided. This indicates a physical aspect to the problem because tillage increases IR. However, there is also an electrochemical side to infiltration problems because certain calcium surfactant treatments can increase IR. Various other methods have been used …

Interclonal Variation Of Primary And Secondary Chemistry In Western Quaking Aspen And Its Influence On Ungulate Selection, Damon A. Winter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides) clones within close proximity to one another can exhibit drastically different levels of browsing by ungulates. The objectives of this study were to (1) determine interclonal differences in plant chemistry between adjacent clones exhibiting different degrees of herbivory which may influence the browsing behavior and patterns of ungulates, and (2) determine if correlation exists in the levels of salicortin and tremulacin between current year's suckers and current year's growth on older trees. This second objective was meant to indicate a protocol for land managers for identifying clones meriting increased protection from herbivory after treatment …

Historical Biogeography Of Velvet Ants (Hymenoptera: Mutillidae) In The North American Deserts And Arid Lands, Joseph S. Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For centuries, scientists have been intrigued by the high amount of biodiversity that is found in the deserts of North America. Recently, several studies have investigated the causes of the high diversity found in desert-dwelling mammals, reptiles, and amphibians. These studies have found that many of these organisms seem to have diversified in response to the same historical events. Little work has been done, however, on diverse desert-dwelling insect groups. In this dissertation, I investigate the patterns of genetic diversity in four groups of nocturnal wasps called velvet ants. I compare the patterns of genetic diversity to the historical events …

Assessment Of Ruminal Fermentation Characteristics Of Condensed Tannin-Containing Forages Using Continuous Cultures, Christina Marie Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two independent studies were conducted to assess the effects of feeding condensed tannin (CT)-containing forages to continuous cultures to evaluate their impacts on ruminal fermentation and digestibility, with an emphasis on methane (CH4) and ammonia-N (NH3-N) production. In Chapter 3, treatments consisted of: 1) 100% alfalfa hay (AH), 2) 50% AH and 50% birdsfoot trefoil hay (dry matter (DM) basis; AHBFTH), and 3) 100% birdsfoot trefoil hay (BFTH). Three replicated runs lasted 8 d each, with the first 5 d allowed for microbial adaptation to the diets, and 3 d for data collection and sampling. Methane, neutral detergent fiber (NDF) …

Assessing Linkages Among Landscape Characteristics, Stream Habitat, And Macroinvertebrate Communities In The Idaho Batholith Ecoregion, Andrew C. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the composition of lotic communities and the landscape processes and habitat characteristics that shape them is one of the main challenges confronting stream ecologists. In order to better understand the linkages among landscape processes, stream habitat, and biological communities and to understand how accurately our measurements represent important factors influencing biological communities, it is important to test explicit hypotheses regarding these linkages. Increasing our understanding of aquatic communities in a hierarchical context and recognizing how well our measurements represent factors structuring aquatic communities will help managers better evaluate the influence of land management practices on aquatic ecosystems, direct conservation …

Season Extension Of Strawberry And Raspberry Production Using High Tunnels, Daniel R. Rowley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

High tunnels have been used successfully in many areas of the world to extend the growing season for numerous crops. However, very little research has been conducted to evaluate the season extension benefits offered by high tunnels to small fruit crops in high elevation growing areas such as the Intermountain West region of the United States. The use of high tunnels was investigated in North Logan, Utah (41.766 N latitude, 1405 m elevation, 119 freeze free days) to extend the growing season for both strawberries and raspberries. June-bearing 'Chandler' strawberries in a fall-planted annual hill system were evaluated for early …

Quantifying Legacy Effects Of Managed Disturbance On Sagebrush Steppe Resilience And Diversity, Julie Ripplinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Land-use legacies can affect landscapes for decades to millennia. A long history of shrub management exists in the sagebrush steppe of the Intermountain West where shrub-removal treatments, a type of managed disturbance, have been implemented for over 50 years to reduce sagebrush cover. The assumption behind managed disturbances is that they will increase forage for domestic livestock and improve wildlife habitat. However, the long-term effects of managed disturbance on plant community composition and diversity are not well understood. We investigated the legacy effects of three common types of managed disturbance (chemical, fire, and mechanical treatments) on plant community diversity and …

Investigation Of The Toxicity And Toxicokinetics Of Selenium From The Accumulator Plant Symphyotrichum Spathulatum (Western Mountain Aster) In Sheep, Amanda Wilhelm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study was designed to observe the effects of selenium from plant material in sheep after a single, oral dose. Purified sodium selenite and selenomethionine were given as positive controls. The plant Symphyotrichum spathulatum (Western Mountain Aster) was collected, analyzed for selenium content, and administered orally to sheep at varying doses according to body weight. Clinical signs were observed for 7 days during which time whole blood, serum, and expired air were collected. Following euthanasia, tissues were collected for histopathological analysis and mineral analysis.

Clinical signs were less apparent than expected and included depression and mild dyspnea in sheep receiving …

Maternal Effects In Transmission Of Self-Medicative Behavior From Mother To Offspring In Sheep, Udita Sanga

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mammals begin learning food preferences in utero and maternally mediated influences early in life help offspring develop their feeding habits. Mammals also learn by individual experience to ingest medicinal compounds such as polyethylene glycol (PEG), which attenuates the negative post-ingestive effects of tannins, a group of potentially toxic plant secondary compounds. The objective of this study was to investigate the transmission of acquired self-medicative behavior from mother to offspring using polyethylene glycol (PEG) as a medicine to relieve malaise caused by tannins. I hypothesized that: 1) mothers trained to associate the beneficial effects of PEG while consuming tannins will pass …

Genomic Perspectives On Evolution In Bracken Fern, Joshua P. Der

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The fern genus Pteridium comprises a number of closely related species distributed throughout the world. Collectively they are called bracken ferns and have historically been treated as a single species, Pteridium aquilinum. Bracken is notorious as a toxic weed that colonizes open fields and poisons livestock. Bracken is also easily cultured and has become one of the most intensively studied ferns. Bracken has been used as a model system for the study of the fern life cycle, fern gametophyte development, the pheromonal mechanism of sex determination, toxicology, invasion ecology, and climate change. This dissertation places bracken within a global …

A Spatio-Temporal Analysis Of Landscape Change Within The Eastern Terai, India: Linking Grassland And Forest Loss To Change In River Course And Land Use, Tanushree Biswas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Land degradation is one of the most important drivers of landscape change around the globe. This dissertation examines land use-land cover change within a mosaic landscape in Eastern Terai, India, and shows evidence of anthropogenic factors contributing to landscape change. Land use and land cover change were examined within the Alipurduar Subdivision, a representative of the Eastern Terai landscape and the Jaldapara Wildlife Sanctuary, a protected area nested within Alipurduar through the use of multi-temporal satellite data over the past 28 years (1978 – 2006).

This study establishes the potential of remote sensing technology to identify the drivers of landscape …

Reproductive Ecology Of Astragalus Filipes, A Great Basin Restoration Legume, Kristal M. Watrous

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Astragalus filipes Torrey ex. A. Gray (Fabaceae) is being studied and propagated for use in rangeland restoration projects throughout the Great Basin. Restoration forbs often require sufficient pollination services for seed production and persistence in restoration sites. Knowledge of a plant's breeding biology is important in providing pollination for maximal seed set.

Reproductive output from four manual pollination treatments (autogamy, geitonogamy, xenogamy, and distant xenogamy) was examined in a common garden. Pod set, seed set, and seed germination were quantified for each of the treatments. Seed set from four wild populations was compared to that of an openly visited common …

Identifying And Understanding The Spatial Distribution Of Bobcat And Coyote Behavior, Ryan Radford Wilson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A common observation in animal space use studies is that animals do not use space uniformly, but rather use some areas of their home ranges and territories with much higher intensity than others. Numerous methods have been developed to estimate these "core areas"; however, all of the current methods available are based on arbitrary rules. Additionally, most studies do not attempt to understand what behavioral processes lead to the observed patterns of non-uniform space use. This study has four main objectives: 1) to develop an objective and more precise method for estimating core areas, 2) to understand the processes leading …

Evaluating Native Wheatgrasses For Restoration Of Sagebrush Steppes, Jayanti Ray Mukherjee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pseudoroegneria spicata and Elymus wawawaiensis are two native perennial bunchgrasses of North America's Intermountain West. Frequent drought, past overgrazing practices, subsequent weed invasions, and increased wildfire frequency have combined to severely degrade natural landscapes in the region, leading to a decline in the abundance of native vegetation. Being formerly widespread throughout the region, P. spicata is a favorite for restoration purposes in the Intermountain West. Elymus wawawaiensis, which occupies a more restricted distribution in the Intermountain West, is often used as a restoration surrogate for P. spicata. However, since most restoration sites are outside the native range of …

A Synthetic Biological Engineering Approach To Secretion- Based Recovery Of Polyhydroxyalkanoates And Other Cellular Products, Elisabeth Linton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The costs associated with cellular product recovery commonly account for as much as 80% of the total production expense. As a specific example, significant recovery costs limit commercial use of polyhydroxyalkanoates (PHA), which comprise a class of microbially-accumulated polyesters. PHAs are biodegradable compounds that are of interest as a sustainable alternative to petrochemically-derived plastics. Secretion-based recovery of PHAs was studied to decrease PHA production costs. Type I and II secretory pathways are commonly used for the translocation of recombinant proteins out of the cytoplasm of E. coli. Proteins were targeted for translocation using four signal peptides (HlyA, TorA, GeneIII, …

Ecology Of Isolated Greater Sage-Grouse Populations Inhabiting The Wildcat Knolls And Horn Mountain, Southcentral Utah, Christopher J. Perkins

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus) currently inhabit about 56% of pre-settlement distribution of potential habitat. In 2005, the Castle Country Adaptive Resources Management Local Working Group (CaCoARM) was formed to address concerns regarding local sage-grouse populations in Carbon and Emery counties. In 2006-2007, CaCoARM identified the Wildcat Knolls and Horn Mountain as areas of special concern for greater sage-grouse conservation. Both sites selected by the group were inhabited by what appeared to be small isolated sage-grouse populations. Factors limiting small isolated greater sage-grouse populations throughout its range are diverse and largely site-specific.

During 2008-2009, I captured, radio-collared, and monitored …

Natural History And Breeding System Of Maguire Primrose, Jacob B. Davidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The goal of this thesis was to examine the breeding system and natural history of the Maguire primrose (Primula cusickiana var. maguirei). Maguire primrose is an endemic, threatened subspecies found only along a narrow corridor within Logan Canyon in northern Utah, USA. This plant displays distinct flower distyly, with clear distinction of pin and thrum morphologies (morphs). The timing of Maguire primrose flower blooms was disparate between upper and lower canyon populations, and the flowers experienced cool temperatures occasionally. I captured eight different species of flying insects visiting Maguire primrose flowers, and made 67 observations of insect visitation. …

Cougar Resource Selection In Two Mountain Ranges In Utah: A Study On Scale And Behavior, Wendy R. Rieth

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

An understanding of habitat relationships is essential for managing hunted species, such as cougar, that are difficult to census. In the first phase of this study, I used aerial telemetry data to examine diurnal cougar resource selection at 2 scales, and compared results between 2 study sites, the Oquirrh Mountains and Monroe Mountain, Utah. In the second phase of this study, I used conditional logistic regression models and GPS collar data from the Oquirrh Mountains to determine whether cougar resource selection varied over 3 behaviors (prey caching, resting at a daybed site, and nocturnal activities) and 2 scales.

Results from …