Life Sciences Commons^™

The Utah Forest Dynamics Plot: Long-Term Ecological Monitoring And Theoretical Ecology In A High-Elevation Subalpine Environment, Tucker J. Furniss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Unified Neutral Theory of Biodiversity has been advanced as a universal theory for species coexistence in forests worldwide, but few studies have examined its relevance to high-elevation, stressful environments. I established the Utah Forest Dynamics Plot (UFDP) in a heterogeneous subalpine forest at 3,091 m elevation on the Colorado Plateau to examine three underlying assumptions of neutral theory (functional equivalence, ecological equivalence, and habitat generality) and one prediction (the species abundance distribution). The UFDP comprises 27,845 stems ≥1 cm diameter at breast height of 17 species, 10 genera, and 6 families over 13.6 ha. The neutral model was a …

Invasive Coqui Frogs Serve As Novel Prey For Birds In Hawaii, And Not As Competitors, Robyn L. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Puerto Rican coqui frog was introduced the Hawaiian Islands in the late 1980s. Because of the frog's loud call and high abundance, the State of Hawaii has spent millions of dollars on its eradication. Conservationists are also concerned that the frog could negatively impact Hawaii's endemic birds, which are already threatened by a host of other invasive species, either by competing with them for insects or by increasing bird predators. The purpose of this research was to investigate the impacts of coquis on Hawaiian birds. First, we examined overlap in prey resources between coquis and birds, and second, we …

Spatial Ecology And Captive Behavior Of Rehabilitated Black Bears In Utah, Patrick J. Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animal movements and space use are fundamental components of life and play integral roles in organismal fitness, population dynamics, and the ecology and evolution of species. The heterogeneous distribution of resources and the movement required to access them, results in ecology being a fundamentally spatial concept. Thus, elucidating animal-habitat relationships is a central focus of wildlife ecology and conservation. I utilized GPS technology, resource selection functions, and generalized linear mixed models, to investigate the immediate post-release movements, denning chronology, release-site fidelity, and season-delineated movements, home ranges, and resource use for six, orphaned and rehabilitated black bears (Ursus americanus). …

Influence Of Disturbance On Greater Sage-Grouse Habitat Selection In Southern Utah, Erica P. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The greater sage-grouse (Centrocercus urophasianus; sage-grouse) is a species of conservation concern that occupies sagebrush-dominated (Artemisia spp.) landscapes across the western United States and southern Canada. The U. S. Fish and Wildlife Service (USFWS) reviewed the status of the sage-grouse in September 2015 and determined that it did not warrant protection under the Endangered Species Act due to collaborative efforts between numerous public and private stakeholders. However, this decision hinged on federal and state commitments to continue science-based management of sagebrush habitats. As human development increases across the west, there is an increasing need for understanding …

Douglas-Fir Beetle Mediated Changes To Fuel Complexes, Foliar Moisture Content And Terpenes In Interior Douglas-Fir Forests Of The Central Rocky Mountains, Andrew D. Giunta

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bark beetle outbreaks have affected millions of hectares of forests across western North America and are a major concern for forest managers. Aside from causing extensive tree mortality, other associated changes include alterations to forest structure in terms of modifications of surface and aerial fuels, which have led to concerns about overall forest health and wildfire risk. The majority of research into the interactions between bark beetles, fuels, and wildfire, has focused on upper elevation forests primarily in lodgepole pine and Engelmann spruce. Little research has been led in lower to middle montane forests which typically are more structurally and …

Structural And Biochemical Characterization Of The Frequency-Interacting Rna Helicase Frh, Jacqueline M. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cells function through a variety of regulatory pathways intricately communicating with one another. These pathways ensure that cellular functions happen at the appropriate times and keep the natural balance within the cell. When pathways do not communicate appropriately, this can lead to disease states and cell death. Two such connected pathways in Neurospora crassa involve the regulation of RNA levels and the circadian rhythms essential for these cells to maintain homeostasis. These pathways are connected by a unique helicase called the Frequency-interacting RNA Helicase (FRH), named for its discovery with the frequency protein involved in the circadian oscillation of the …

Comparing Conventional And Noninvasive Monitoring Techniques For Assessing Cougar Population Size In The Southern Greater Yellowstone Ecosystem, Peter D. Alexander

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Determining the abundance or density of wildlife populations is needed for informed decision-making by wildlife biologists. Cougars (Puma concolor), however, are a highly secretive species occurring at very low densities across the landscape, and thus their populations are difficult for biologists to accurately assess. The conventional, and most trusted, method entails physically trapping and radio-collaring as many cougars as possible in a population, and then performing a simple count to determine a minimum population size. While accurate, this method is prohibitively expensive, logistically challenging, and behaviorally disruptive to the study animal. Many noninvasive surveying techniques, such as camera …

Effects Of Thermosonication On Microbial Population Reduction And Solubility Index In Skim Milk Powder, Nicola F. Beatty

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermosonication has been researched as a means to improve shelf life, quality, and functional properties in dairy products. This study explored the effects of thermosonication on the inactivation of Geobacillus stearothermophilus in concentrated skim milk as a function of total solids content, temperature, and time and investigated changes in the solubility of the skim milk. Results showed thermosonication had an increased bactericidal effect on both vegetative cells and spores as compared to heat treatment alone without affecting solubility. A model was developed using response surface analysis showing that log reductions produced by thermosonication can be predicted based on a polynomial …

Entrepreneurs' Perceived Factors Of Success And Barriers-To-Entry For Small Business And Farm Operations In Rural Paraguay, Braden J. Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Both agriculture and nonagriculture activities are important for Paraguay's economy and its rural development plan. Ensuring opportunity for successful enterprise creation and expansion will facilitate new business entrance, while also growing rural economies. Past research has identified many factors that contribute highly to business and farm operation success, though little information exists about the perceptions of would-be entrepreneurs.

This study analyzes perceptions and characteristics of young, would-be entrepreneurs and agriculture producers in rural Paraguay to better understand their views of business/farm success and hurdle factors. Results suggest that increased experience, education and business exposure will decrease perceptions of many barrier …

Effect Of Chronic Administration Of Oxytocin On Corpus Luteum Function In Cycling Mares, Katherine Clissold Parkinson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Undesirable and variable behavior in mares related to the reproductive cycle is a common issue reported in the equine industry, especially for female horses in a performance setting. These behaviors can interfere with and decrease, overall performance. The objective of this study was to determine if administration of 60 units of the hormone oxytocin once daily for 29 days, regardless of when treatment was initiated during the estrous cycle, would induce prolonged corpus luteum function in cycling mares. Mares were randomly assigned to two groups: 1) saline-treated control (n=7) and 2) oxytocin-treated (n=9). Control mares received 3 cc saline and …

A Spatiotemporal Mountain Pine Beetle Outbreak Model Predicting Severity, Cycle Period, And Invasion Speed, Jacob P. Duncan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (MPB, Dendroctonus ponderosae), a tree-killing bark beetle, has historically been part of the normal disturbance regime in lodgepole pine (Pinus contorta) forests. In recent years, warm winters and summers have allowed MPB populations to achieve synchronous emergence and successful attacks, resulting in widespread population outbreaks and resultant tree mortality across western North America. We develop an age-structured forest demographic model that incorporates temperature-dependent MPB infestations: the Susceptible-Infested-Juvenile (SIJ) model. Stability of equilibria is analyzed as a function of population growth rates, and indicates the existence of periodic outbreaks that intensify as growth rates …

Investigation Of The Tailoring Steps In Pradimicin Biosynthesis, Kandy L. Napan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research focused on the investigation of the late steps in the biosynthetic pathway of the novel antifungal and antiviral pradimicins A-C. Pradimicins were first isolated from the soil bacterium Actinomadura hibisca. These bioactive molecules are assembled by a type II polyketide biosynthetic pathway. Although the biosynthetic gene cluster of pradimicin has been identified, the functions of the biosynthetic genes and how they work collaboratively to form the final structures of pradimicins remain unknown. This research aims to functionally characterize the enzymes involved in the late steps of the biosynthetic route.

The early biosynthetic steps of pradimicins have been …

Intraspecific Variation In The Response Of Elymus Elymoides To Competition From Bromus Tectorum, Rebecca K. Mann

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the western United States, thousands of acres of degraded rangelands are dominated by aggressive invasive species such as cheatgrass (Bromus tectorum), and are seeded by managers with native plants in an attempt to restore species diversity, wildlife habitat, and ecosystem services. There are many options for obtaining seeds of native plants; for instance, they can be collected from the region where restoration is to occur, or they may be purchased through commercial producers. For a given plant species, managers may also select seeds from unique subspecies, cultivars, and populations. Genetic differentiation among these within-species groups can not only affect …

Effects Of Carboxymethyl-Lysine In Heat Processed Foods On The Plasma Metabolome In Mice, Zhou Fang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Carboxymethyl-lysine (CML), an advanced glycation end product (AGEs), is formed during the cooking process and may induce toxic effects on human health. The effect of dietary CML on the plasma metabolite profile was investigated. Mice were fed with one of five different diets: AIN93 diet (negative control), a 45% kcal from fat Diet Induced Obesity diet (DIO; positive control); CML0, TWD (Total Western Diet) with low CML; CML1, TWD with medium CML, and CML2, TWD with high CML for 8 weeks, and the plasma metabolome was determined by Gas Chromatography-Mass Spectrometry (GC-MS). In addition quantitative analysis of plasma glucose level …

Modulation Of The Nutritional Context And Early Experience As New Tools To Increase The Use Of Medusahead (Taeniatherum Caput-Medusae Ssp. Asperum) By Grazing Sheep, Juan J. Montes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Medusahead is an invasive weed that reduces wildlife habitat and biodiversity as well as commercial and recreational value of land. Grazing represents a sustainable method for its control but stakeholders claim that livestock will not eat medusahead because of its low feed value. This research explored a supplementation program, along with experiences early in life with mother to enhance use of medusahead by sheep. Results showed that an energy supplement did not enhance medusahead use by sheep but that early experience with mother influenced yearlings to use the weed more evenly across days. When availability of the weed was low …

Biodiversity, Community Dynamics, And Novel Foraging Behaviors Of A Rich Native Bee Fauna Across Habitats At Pinnacles National Park, California, Joan M. Meiners

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Global concern about honeybee declines has spurred feverish research about the status and protection of this single species, yet our understanding of the ecology and issues impacting thousands of species of native bees lags behind. Pinnacles National Park, America's newest, near Salinas, California, is currently the most densely biodiverse area for native bees known on the planet. Recent work by researchers at Utah State University and the USDA-ARS has documented 479 species of native bees in only 42 square miles of this park. During two years of field studies and 308 collector days, we assembled data on 52,853 bee specimens …

Anthropogenic And Natural Stressors And Their Effect On Immunity, Reproduction, And The Stress Response, Lorin A. Neuman-Lee

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Animals must be able to cope with many natural and human-made stressors in order to successfully survive and reproduce. These stressors can come in many forms and are increasing as human activities become more and more prevalent across the globe. In order to cope with these stressors, organisms must allocate limited energy away from processes such as reproduction to mount a stress response. This stress response involves the activation of the hypothalamic-pituitary-adrenal axis and results in a cascade of hormones and down-stream effects, such as changes in reproduction and immune function. In order to understand how reptiles and amphibians cope …

Utah Lotus: North American Legume For Possible Use In Rangeland Revegetation In The Southern Great Basin Of The Western United States, Jason M. Stettler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis project explored the production and forage quality characteristics of Utah lotus (Lotus utahensis Ottley) and scrub lotus (L. wrightii (A. Gray) Greene) seed collections during a two-year period. The variation of 14 Utah lotus and five scrub lotus seed collections was evaluated by measuring important plant characteristics at three common garden sites in northern Utah. In addition, the genetic structure of the collections was determined by molecular biological techniques. Large variation was observed among collections for all phenotypic traits measured, with Utah lotus and scrub lotus being phenotypically quite different. Two collections of Utah lotus (LU-5 …

The Role Of Gpr84 In Medium-Chain Saturated Fatty Acid Taste Transduction, Yan Liu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The prevalence of overweight or obese in adults has nearly doubled during the past two decades, and obesity increases the risk of heart disease, diabetes, and even some types of cancer. One of the factors closely linked with the obesity epidemic is overconsumption of dietary fat. Accumulating evidence has supported the existence of the "taste of fat", and more and more studies have focused on identifying the mechanisms of fatty acid detection by gustatory system. In this study, I showed for the first time that medium-chain saturated fatty acids (MCFAs) were able to activate taste cells isolated from mice, and …

Examining The Utah 4-H Volunteer Program: The Effects Of Donation And Motives In Relation To Volunteer Recruitment And Retention, Kelsey W. Romney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah 4-H is a volunteer driven, youth development program. The success of Utah 4-H depends on the recruitment and retention of volunteers. The purpose of this study was to identify recruitment and retention motivators and how those motivators related to the unique cultural demographics of Utah 4-H volunteers. Results show that volunteers did not begin volunteering because of their religious affiliation; however, those who were religious were more likely to remain active volunteers for Utah 4-H. The underlying motive of 4-H volunteers, related to all types of involvement in the program, was an altruistic desire to help others.

Effects Of Feeding High-Moisture Corn Grain With Slow-Release Urea In Dairy Diets On Lactational Performance, Energy And Nitrogen Utilization, And Ruminal Fermentation Profiles By Lactating Cows, Braden M. Tye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this experiment was to determine if nutrient utilization and energy partitioning by lactating dairy cows would differ in response to dietary corn grain (CG) types [steam-flaked corn (SFC) vs. high-moisture corn (HMC)] and to test if the types of CG would interact with slow-release urea (SRU) on lactational performance and energy utilization. Eight multiparous Holstein cows (32 ± 8.2 days-in-milk) were used in a duplicated 4 × 4 Latin square with one square consisting of ruminally cannulated cows. A 2 × 2 factorial arrangement was used to test 4 dietary treatments: SFC without SRU, SFC with SRU, …

Migratory Waterbird Ecology At A Critical Staging Area, Great Salt Lake, Utah, Maureen G. Frank

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Millions of birds use Great Salt Lake, Utah, during their migrations every year. While many of the birds use the shorelines and wetlands around Great Salt Lake, there are three migratory species that use the open waters of Great Salt Lake: Wilson's phalaropes (Phalaropus tricolor), red-necked phalaropes (Phalaropus lobatus), and eared grebes (Podiceps nigricollis). Eared grebes feed primarily on brine shrimp (Artemia fanciscana), while phalaropes are thought to consume brine flies (Ephydridae) and brackish-water aquatic invertebrates. Despite the reliance of phalaropes and eared grebes on the invertebrate prey of Great Salt Lake, …

Does Experience With Sagebrush In Utero And Early In Life Influence The Use Of Sagebrush By Sheep?, Ashley T. Longmore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Learning from mother begins early in the developmental process and can have lifelong effects when it comes to forage preferences. Recent research suggests that mothers are a powerful and positive influence before birth. Pregnancy is not an incubation period buy a staging period for well-being and disease later in life. Better understanding the developmental processes which take place in utero and the effects they have later in life may help us create management plans that utilize grazing animals to their full potential as landscape manipulators.

Using in utero and early-life programming as a management tool is a relatively new concept, …

Emerging Technology To Exclude Wildlife From Roads: Electrified Pavement And Deer Guards In Utah, Usa, Joseph P. Flower

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Vehicle collisions with large wild animals threaten public safety, can harm wildlife populations, and often result in substantial property damage. The most effective
way to reduce these collisions is to install wildlife fencing along the roadway and provide structures that enable wildlife to cross roads safely. However, if access roads that bisect fencing do not include barriers to deter animals from entering the highway, these measures can become ineffective. The purpose of my research was to: 1) evaluate the effectiveness of barriers currently used to exclude wildlife from highways, and 2) determine whether cattle guards augmented with segments of electrified …

Rapid Savanna Response To Changing Precipitation Intensity, Ryan S. Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate change has the potential to cause large-scale changes in plant growth, biodiversity, and biosphere-climate feedbacks. A pervasive aspect of climate change is that as the atmosphere warms, precipitation events are likely to become less frequent but more intense, because warmer air can hold more water. Larger precipitation events can be expected to change plant productivity and community composition, particularly in semiarid ecosystems such as savannas. Savannas are of particular interest because they are spatially expansive at the global scale, they are important to humans for food production, and they are known to be sensitive to changes in soil water …

An Allometric Approach To Evaluate Physiological And Production Efficiencies In Tree Size For Tart Cherry And Apple Orchard Systems, Zachary T. Brym

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In orchard systems, the size of a tree and the physical structure of its canopy influences how the tree gathers resources and uses them to produce fruit. Smaller orchard trees produce a higher proportion of fruit relative to their size. Small trees also produce higher quality fruit than larger trees. These relationships were demonstrated for apples and tart cherries grown in Utah. In physiological ecology, models called allometries have been developed that explain how the size of wild plants is related to growth, architecture, and reproduction. These models were applied to apple and tart cherry orchard systems and revealed consistent …

Control Of Large Stands Of Phragmites Australis In Great Salt Lake, Utah Wetlands, Chad R. Cranney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phragmites (common reed) is a non-native, invasive perennial grass from Eurasia that is taking over wetlands across North America. In Utah, Phragmites has expanded to cover tens of thousands of acres in and around the Great Salt Lake (GSL). The GSL and its associated wetlands are recognized regionally and hemispherically as an important bird area (IBA) that provide critical habitat for a wide variety of wetland dependent birds. The invasion and expansion of Phragmites has replaced many of the high quality habitats these avian populations rely on. This research aimed to determine the most effective methods to control Phragmites and …

Effects Of Environmental Water Rights Purchases On Dissolved Oxygen, Stream Temperature, And Fish Habitat, Nathaniel R. Mouzon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Degraded water quality has reduced aquatic species abundance and survivability in Nevada’s Walker River. Low instream flows and increased nutrients affect native fish populations through high daily stream temperatures and low nightly dissolved oxygen concentrations. Increasing streamflow, through environmental water purchases, may improve water quality and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses River Modeling System, a computer model, to estimate streamflows, stream temperatures, and dissolved oxygen concentrations in the Walker River. Streamflow increases are simulated to determine potential improvements to high water temperatures and low dissolved oxygen concentrations, enabling the prioritization of …

Amelioration Of Chikungunya Through Inhibition Of The Inflammatory Response, Ashley L. Dagley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

CHIK is an emerging viral disease that is rapidly spreading around the world and causing significant illness in infected people. This virus is spread through the bite of an infected mosquito. Symptoms of disease include high fever, rash, joint pain and arthritis-like symptoms. This disease has recently been reported in the United States, mainly as a result of importation from vacationers to areas affected by this disease. The purpose of this research was to model the disease in mice in order to identify intervention strategies that reduce disease in the hope that it will be useful in the treatment of …

Investigation Of Solubilization, Cold Gelation, And Rennet Coagulation Properties Of Highly Concentrated Micellar Casein Concentrate For Use In Cheese Making, Ying Lu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work demonstrated potentials to use a microfiltrated, diafiltrated, and vacuum-evaporated milk protein concentrate-highly concentrated micellar casein
concentrate (HC-MCC) for use in cheese making. Previously, ultrafiltrated milk concentrate has been used for cheese making to improve cheese yield and increase milk processing ability. However, ultrafiltrated milk contains high level of serum protein, which negatively impact cheese quality during aging. Microfiltrated milk is more suitable for cheese making with most serum proteins removed.

The project evaluated the potential of cheese making using recombined concentrated milk (RCM) by mixing HC-MCC and cream. We identify the method to solubilize …