Digital Commons Network^™

Local And Regional Drivers Of Biodiversity: From Life-History Traits To System-Level Properties, Sarah R. Supp

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biodiversity research includes the study of where species occur, the commonness and rarity of species, the number of species, and the diversity of life-history traits that occur in a single location, or community. Research is increasingly recognizing that a combination of local and regional scale processes influence community dynamics over ecological and evolutionary time-scales. However, ecologists currently lack a comprehensive understanding of the mechanisms driving biodiversity in different systems and at different spatial scales. This presents a critical problem because without understanding the important mechanisms that determine and maintain biodiversity, it is difficult to accurately predict community response to environmental …

Cationic Starch Synthesis, Development, And Evaluation For Harvesting Microalgae For Wastewater Treatment, Renil John Anthony

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae are the preferred crop for the production of biodiesel. Microalgae are microplants that have the ability to harness sunlight more efficiently than other plants and store 20-80% lipids per g of dry algae in their cells. Microalgae have the extraordinary ability to grow in brackish water or wastewater. Microalgae can be grown in municipal wastewater to uptake phosphorus and nitrogen and remediate the wastewater of these nutrients. Microalgae thus cultivated accomplishes a dual role of wastewater treatment and provides a sustainable feedstock for biofuels and other bioproducts.

This study focused on efficiently harvesting microalgae from water using modified starch. …

Factors That Influence Secondary Students To Join The Collegiate Ffa, Sara Vanderbos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Student involvement on college campuses is important for the professional growth, leadership development and learning of today's college student. This research sought to determine the factors that influence former high school FFA members' reasons for joining and participating in the Collegiate FFA.

The study showed that students who are involved in the National FFA at the secondary level are more likely to join Collegiate FFA while attending a university that offers the Collegiate FFA option. These students were actively engaged on campus and were interested in helping others. Collegiate FFA programs, the National FFA, and universities across the country should …

Physiological Response Of Kentucky Bluegrass Under Salinity Stress, Lijun Wang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salinity is a significant stress for plants world-wide. In agriculture, salts reduce germination, overall growth, yield, and sometimes death in crop plants. Salinity similarly affects turfgrass in our urban landscapes. Kentucky bluegrass (Poa pratensis L.) is the most widely used cool-season grass in the northern part of the United States, including the cool-arid West, but generally is a salt sensitive species. The overall objectives of this study were to study the physiological responses of Kentucky bluegrass to salt stress and to evaluate the genetic similarity among the cultivars used in the research.

Four Kentucky bluegrass entries, two salt-tolerant and …

Reproductive Biology And Impacts Of Energy Development On Physaria Congesta And Physaria Obcordata (Brassicaceae), Two Rare And Threatened Plants In The Piceance Basin, Colorado, Sarah Lynn Clark

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oil and gas development has increased profoundly over the last 20 years in the United States. A large underground deposit of natural gas has been found in the Piceance Basin, which is located in the northwestern part of the state of Colorado. This deposit occurs in an area inhabited by two rare mustard species commonly named the Dudley Bluffs bladderpod and the Dudley Bluffs twinpod. These two plant species are also listed as threatened by the US Fish and Wildlife Service. Concerns about gas development effects on these rare plants have motivated research that quantifies these potential impacts. Through funding …

Enhancement Of Random Forests Using Trees With Oblique Splits, Andrejus Parfionovas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Statistical classification is widely used in many areas where there is a need to make a data-driven decision, or to classify complicated cases or objects. For instance: disease diagnostics (is a patient sick or healthy, based on the blood test results?); weather forecasting (will there be a storm tomorrow, based on today's atmospheric pressure, air temperature, and wind velocity?); speech recognition (what was said over the phone, based on the caller's voice level and articulation); spam detection (can the unsolicited commercial e-mails be identified by their content?); and so on.

Classification trees …

An Environmental History Of The Bear River Range, 1860-1910, Bradley Paul Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area.

By the turn of the 20th century, …

A Data-Intensive Assessment Of The Species Abundance Distribution, Elita Baldridge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

One of the most commonly observed patterns in ecology is the fact that at most locations there are a large number of relatively rare species, composed of only a few individuals per species, and a small number of relatively common species. This pattern of commonness and rarity is quantified by the species abundance distribution. As one of the most commonly observed patterns in ecology, it has been studied intensively for over 100 years.

A major emphasis of this research has been developing models to try to understand the forces that generate such a general pattern. As a result, there are …

A Middle To Late Holocene Record Of Arroyo Cut-Fill Events In Kitchen Corral Wash, Southern Utah, William M. Huff

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Arroyos are steeply entrenched channels that form by incision into weakly consolidated valley-fill alluvium. This study attempts to offers clues into the processes behind their formation by dating arroyo sediments using luminescence and radiocarbon techniques. The importance of understanding arroyo formation is due to a possible linkage with decadal to centennial-scale climate fluctuations. In the 1800s and early 1900s, many of the shallow, perennial streams throughout southern Utah that used for a variety of agricultural and domestic uses were incised up to ~30 m into their alluvium by frequent and high-magnitude flood events. The economical and ecological effects of these …

Token Reinforcement And Resistance To Change, Eric A. Thrailkill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Interventions based on a token economy effectively reduce problematic behavior. Yet, treatment gains deteriorate once an intervention is discontinued. It is important to better understand the persistence of behavior maintained by token reinforcement in simple experimental procedures. A Pavlovian association with primary reinforcement is said to endow neutral stimuli (e.g., coins, poker chips, lights, signs, stickers, etc.) with their own function to strengthen behavior as conditioned reinforcers. Behavioral momentum theory suggests that resistance to change under conditions of disruption is the appropriate measure of response strength. However, some animal studies have suggested that conditioned reinforcement may not affect resistance to …

Hazard Classification And Hydraulic Remediation Options For Flat-Topped And Ogee-Crested Low-Head Dams, Riley J. Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The dangerous hydraulic conditions that can form downstream of a low-head dam were investigated. These dangerous hydraulic conditions have been the cause of hundreds of drowning incidents since the construction of the first low-head dams. Two primary objectives were identified for this study, each of which were primarily performed using the Computational Fluid Dynamics software, Flow-3D^®, with physical models used to verify the numerical results. The first objective was the identification of a risk factor made up of easily measured parameters that could accurately predict when the dangerous hydraulic conditions are present at a low-head dam. The risk …

An Ecofeminist Perspective On The Influences That Promote And Restrict Three Early Childhood Educators' Inclusion Of Open-Ended Outdoor Learning, Anne K. Mackiewicz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to explore the influences that promoted and restricted three women early childhood educators' inclusion of open-ended outdoor learning in a Head Start center. With the recorded history of human's impact on nature, along with the majority of women in the early childhood workforce, I chose a theory, ecofeminism, that looked at both the domination of women and nature in the early childhood setting.

The methods included participant interviews, observations, and a study of the site's documents. Four themes were identified as promoting or restricting open-ended outdoor learning. These themes included: (a) participant's attitudes, (b) …

Effects Of Inorganic Nutrients And Dissolved Organic Carbon On Oxygen Demand In Select Rivers In Northern Utah, Joseph L. Crawford

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Our nation’s waterways are a valuable resource whose quality is influenced by their surroundings as well the amount of nutrients (largely nitrogen and phosphorus) in the water. Nutrients play an important role in aquatic ecosystems; however, if nutrient levels become too high, it is detrimental to water quality. Excess fertilizer that runs off of agricultural land and into the rivers and streams is a common source of nutrients in our waterways. Other sources of nitrogen and phosphorus include effluent released from wastewater facilities.

There are many negative side effects of high nutrients in the water. They can create large algal …

Growth Performance And Nutrient Metabolism Of Pasture-Finished Beef Steers And In Vitro Fermentation Characteristics Of Pasture Forages In Continuous Cultures, Cuk Tri Noviandi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A 2-year grazing study was conducted to evaluate the growth performance, ruminal fermentation, carcass characteristics, and fatty acid compositions in subcutaneous adipose tissue of beef steers grazing tall fescue (Festuca arundinacea Shreb.; TF) pastures without or with N fertilization. Nitrogen fertilization increased crude protein concentration of TF pasture and average daily gain of beef steers. Increase in total volatile fatty acids (VFA) and ammonia-N (NH₃-N) concentrations were detected in steers grazing fertilized TF. In comparison with steers on feedlot, pasture-finished steers had greater proportions of cis-9, trans-11 CLA and C18:3 n-3, …

Forage Yield And Quality Of Binary Grass-Legume Mixtures Of Tall Fescue, Orchardgrass, Meadow Brome, Alfalfa, Birdsfoot Trefoil, And Cicer Milkvetch, Steven R. Cox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Managed pasture forms the foundation for much of the U.S. livestock iv production. Increased forage yield and quality can be achieved with nitrogen (N) fertilizer but increases the cost of pasture production. Rising prices of N have led to a return to the use of grass-legume pastures to reduce or replace commercial N fertilizer. There is a need to identify viable grass-legume mixtures and species planting ratios for the region of the Intermountain Western United States The purpose of this study was to identify grass-legume combinations and planting ratios that maximize forage production and forage quality in irrigated pastures. The …

The Application Of Tomographic Reconstruction Techniques To Ill-Conditioned Inverse Problems In Atmospheric Science And Biomedical Imaging, Vern Philip Hart Ii

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tomography is an imaging technique in which 3D models of objects are created from several 2D projections viewed at different angles. When the number of available projections is limited, the resulting data are said to be sparse. This restriction is often a direct result of the imaging geometry used to acquire the data. One-sided views and a small number of receivers can reduce the range of available projections, which makes the object more difficult to reconstruct. Approximate solutions to difficult imaging problems can be obtained using a class of iterative algorithms known as the algebraic reconstruction techniques (ARTs). The presented …

Mechanisms And Signal Transduction Pathways Involved In Bovine Oocyte Activation, Ammon Hanson Bayles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Being able to create a genetically identical, living replicate of a prized animal sounds impossible. Through advanced scientific methods and the wonders of mother nature it can be accomplished by a process called cloning. In 2003, the USU Animal, Dairy, and Veterinary Science department and Dr. Kenneth L. White gained world wide recognition when they, along with a team for Idaho, cloned the first equine species.

Cloning certain animals could be very advantageous to the agricultural industry. Prized animals that have died could be cloned, producing the best meat and milk supply. Animals that are sterile or endangered could be …

Modulation Of The Host Response To Tacaribe Arenavirus Infection In Ag129 Mice By My-24, Eric Sefing

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

MY-24 is a new antiviral compound recently shown to protect immunocompromised mice from lethal challenge with Tacaribe virus (TCRV). Tacaribe virus is incapable of causing disease to humans, but is closely related to the highly pathogenic New World arenaviruses that cause often-fatal viral hemorrhagic fever syndromes. Remarkably, MY-24 prevents mortality without reducing virus burden in the circulation or tissues. To investigate the mechanism by which MY-24 protects AG129 mice against Tacaribe virus infection, we first characterized the natural history of disease in the model with an emphasis on host immune response and blood vessel function to establish the best times …

Biodiesel Production From Mixed Culture Algae Via A Wet Lipid Extraction Procedure, Ashik Sathish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Development of renewable sources of energy has received significant interest due to the rising costs of energy and the environmental impact of using fossil fuels. Biodiesel production from renewable sources of oil has shown promise of helping to replace or reduce dependence on petroleum based diesel thereby reducing demand for crude oil. Microalgae have been considered as a strong candidate for the production of large quantities of renewable oil for biodiesel production.

Microalgae are single cell photosynthetic organisms that posses the capability to produce renewable oil at rates much faster than land based plants and crops. In addition, microalgae can …

Synthesis And Biological Activity Of Aminoglycosides And 1,4-Naphthoquinone Derivatives, Marina Fosso Yatchang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research described in this dissertation is at the interface of organic chemistry and biology, and it aimed at designing and synthesizing biologically active molecules for the possible development of therapeutic agents.

Spinal muscular atrophy is an incurable disease that affects 1 in every 6000 babies, making it the leading genetic cause of infant mortality. While no treatment is available, efforts are being taken to solve this issue. Part of the work outlined in this dissertation was carried out in collaboration with researchers from the University of Missouri to investigate a potential therapeutic for this disease.

In addition, the continuous …

The Effects Of Bison On Cattle Winter Range In The Henry Mountains Of South Central Utah: Resolving A Conflict, Ian M. Ware

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The American Bison in the Henry Mountains are one of the last free-roaming, genetically pure herds of bison remaining in North America. Over the last decade, the herd has used a cattle winter range during the summer and early fall, creating a conflict between the wildlife officials who manage the bison population, and Bureau of Land Management officials and local ranchers who manage the rangeland. At the heart of this conflict is the question of whether bison are negatively impacting the rangeland resource, potentially reducing the abundance of preferable plant species. Negative impacts could include reduced forage availability in the …

Population Dynamics And Movements Of Translocated And Resident Greater Sage-Grouse On Anthro Mountain, Utah, Natasha W. Gruber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greater sage-grouse (Centrocercus urophasianus) populations have declined range-wide. Species translocations have been identified as a conservation strategy to augment declining populations in restored habitats. I evaluated protocols previously used to successfully translocate greater sage-grouse in Utah by comparing annual production, survival, habitat use, integration and seasonal movements of translocated birds and their chicks to the resident population. To conduct this study, I translocated 60 greater sagegrouse hens captured and radio-collared on Parker Mountain to Anthro Mountain in the spring of 2009 and 2010. I also captured and radio-collared 19 resident hens to serve as my control group. All …

Factors Influencing Relocation Success Of Utah Prairie Dog (Cynomys Parvidens), Rachel Curtis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah prairie dogs have been extirpated in 90% of their historic range due to introduced disease, eradication, and habitat destruction. Most of the population lives on private land where animals burrow in lawns and agricultural fields, which keeps this threatened species continually in conflict with landowners. The Utah Division of Wildlife Resources has been relocating prairie dogs from private to public land since the 1970s, but relocations have been largely unsuccessful due to high mortality. Prairie dogs are highly social animals, but they are usually relocated without regard to their family group, or coterie. Coteries typically consist of one reproductive …

Utah Angler Specialization And Its Relationship To Environmental Attitudes And Angler Motivations, Joseph W. Unger Iii

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

For this research, I sampled 10,000 anglers who purchased a Utah fishing or fishing/hunting combination license from January through November, 2011. An online survey link was provided to the potential participants during November-December, 2011, to determine levels of specialization, motivations for fishing, and environmental awareness/concern. Anglers were also compared to a sample from the general public to compare the two groups’ feelings toward several practices taking place on public lands. Finally, anglers were divided into consumptive and nonconsumptive subgroups to compare the environmental attitudes of these two groups.

Three angler specialization groups were identified from the sample of respondents. Anglers …

Examination Of Nonpoint Source Nutrient Export From A Snowfall-Dominated Watershed, Lindsey Deboer Carrigan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study examined nonpoint source pollution via tributaries to Pineview Reservoir. Since few literature values of export coefficients are available for snowfall-dominated watersheds such as Pineview, locally scaled rates were quantified using an upstream-downstream bracketing technique. Nitrogen and phosphorus grab samples were manually collected and discharge measurements were conducted during the annual study period. Additionally, high-frequency monitoring sensors that measured EC, temperature, turbidity, and water level were deployed at the up- and downstream sites to represent short-duration transport events and to examine watershed processes on a more representative time scale.

Daily nutrient loads were estimated from grab samples and flow …

Characterization Of The Involvement Of Integrins, Focal Adhesion Kinase, And Phospholipase C Enzymes Endogenous To The Oocyte In Bovine Fertilization And Oocyte Activation, Benjamin Rand Sessions

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Center for Integrated Biosystems (CIB) and Animal, Dairy, and Veterinary Sciences (ADVS) Department at Utah State University propose a multi-year molecular study of cattle gamete interactions to improve our basic understanding of fertilization. The CIB and ADVS will utilize existing collaborations in addition to recruiting state and federal funding sources to complete the extensive project.

Various laboratory techniques will be used to discover the molecular players of fertilization in hopes of shedding light on a variety of human infertility issues due to problems at the gamete level. A more complete understanding of fertilization could also lead to the development …

An Exploration Of The Relationships Among Connectedness To Nature, Quality Of Life, And Mental Health, Peter G. Tauber

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent decades, a new branch of psychology has emerged—ecopsychology. This field looks at the complex relationship between human beings and the natural world. Previous research has shown the importance of direct experiences in nature for the promotion of human health and well-being. However, it is still not understood why these experiences in nature carry so much importance.

It is possible that the concept of connectedness to nature (CTN) plays a role in this relationship between nature and wellness. CTN is defined as feelings of close affiliation with the natural world in a physical, cognitive, and emotional manner. Previous research …

Reinforcer Magnitude And Resistance To Change Of Forgetting Functions And Response Rates, Meredith Steele Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enhanced memory that is less susceptible to disruption has been demonstrated previously, by presenting more reinforcement for correct responses (e.g., a higher probability of reinforcement) in a conditional discrimination task. The purpose of the present experiment was to extend our current understanding of this phenomenon to a different dimension of reinforcement (i.e., magnitude). This would offer additional techniques for delivery of reinforcement within applied settings (e.g., a classroom) that could promote accurate and persistent memory. The present experiment, therefore, was conducted to investigate the effects of reinforcer magnitude on resistance to disruption of remembering and response rates. Pigeons were exposed …

The Effects Of Habitat Manipulations On Utah Prairie Dogs (Cynomys Parvidens) And Their Habitat On The Awapa Plateau Recovery Area In South-Central Utah, Gretchen Elizabeth Caudill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah prairie dogs have been listed, in some capacity, under the Endangered Species Act since 1972. The lack of suitable habitat, particularly cool season grass cover,
has been identified as the primary factor impeding species recovery. Due to reproduction costs, Utah prairie dogs require a large quantity of cool season grasses. Lack of recovery has also been attributed to poor juvenile survival. Increased resources have been shown to increase weights, which would increase survival through the winter.

Beneficial habitat management techniques for Utah prairie dogs have yet to be determined for the Awapa Plateau recovery area. Utah prairie dogs require …

Farmer, Miner, Ranger, Writer: Interpreting Class And Work In The Writing Of Wendell Berry And Edward Abbey, Tyler Austin Nickl

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This study compares some of the essays and novels of two well known, environmental writers: Wendell Berry and Edward Abbey. Usually, these writers are discussed for their environmental politics and representations of nature, but this study examines the ways in which each of these writers discusses class and manual labor. This aspect of Abbey’s and Berry’s works has not yet received the attention it deserves. With this focus in mind, I make the following conclusions: 1) An author’s view of society (as expressed by their opinions of class and socioeconomic status) necessarily affects their view of nature. 2) Berry’s occupational …