Life Sciences Commons^™

Understanding Plant Secondary Metabolites; Above And Below Ground, Andrea K. Clemensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plants naturally produce primary and secondary metabolites. Primary metabolites are directly involved with plant growth and metabolic function. Plant secondary metabolites (PSM) were once thought of as metabolic waste products, and more recently viewed as toxins to herbivores. However, ongoing research shows that PSM are beneficial to herbivores at low doses, and PSM aid plants by attracting pollinators, recovering from injury, protecting from ultraviolet radiation, increasing drought tolerance, and aid in defense against pathogens, diseases, and herbivores. Plant secondary metabolites also influence soil nutrient cycling, and can increase the sustainability of agroecosystems. Endophyte-infected tall fescue (Festuca arundinacea Schreb.), which …

Impacts Of Phragmites Australis Management On Wetland Plant Community Recovery, Seedbank Composition, And The Physical Environment In The Chesapeake Bay, Eric L. G. Hazelton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Biological invasions have adverse economic, cultural, and ecological effects worldwide. Among the most impactful in North America is the invasion of Phragmites australis (Phragmites), a large-scale clonal grass that rapidly colonizes wetlands. Phragmites crowds out native plants and alters habitat for native fauna. In doing so, Phragmites also alters human access to water resources and has adverse economic effects, including decreasing property value, inhibiting recreational use, and limiting populations of game species.

The efforts described in this dissertation are a component of a large, multidisciplinary effort to better understand the anthropogenic stressors to Chesapeake Bay, Maryland, at the …

Relationships Among Invasive Coqui Frogs, The Small Indian Mongoose And Rat Species In Hawaii, Shane A. Hill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Non-native species are increasing globally, and with this increase, it is likely that there will be new, unique relationships found among non-natives as well as additional impacts on native species. Rats and mongooses have been introduced to islands throughout the world where they impact native species, including birds, reptiles, and amphibians. The coqui frog was introduced to Hawaii in the 1980’s, where there were already abundant rat and mongoose populations. Previous research suggests that the high densities of coqui frogs may provide enough of a new food source for mongooses and rats that their populations would grow larger than they …

Utilizing Legumes To Improve Production And Nutritive Value Of Intermountain West Pastures, Jacob T. Briscoe

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Pastures in the Intermountain Western United States mainly consist of cool-season grasses which lack production without supplemental nitrogen. Legumes provide nitrogen at reduced cost compared to nitrogen fertilizer. There is a need for proven methods of inter-seeding legumes into existing cool-season grass pastures as well as knowledge of how animals prefer legumes to grasses and how the nutritive value of forages change throughout the growing season. This research provides a resource for effective integration of legumes into pastures of the Intermountain West. Alfalfa, birdsfoot trefoil, and cicer milkvetch were inter-seeded into existing cool-season grass pastures following pretreatments of light tillage, …

Comparative Pollination Efficacies Of Bees On Raspberry And The Management Of Osmia Lignaria For Late Blooming Crops, Corey J. Andrikopoulos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Unlike other rosaceous fruit crops such as apple and cherry, commercial raspberry cultivars are largely self-fertile and can set fruit in the absence of pollinators. However, their floral morphology often prevents complete self-pollaintion. Incomplete pollination yields unmarketable small or crumbly fruits. Insect visitation is therefore essential to maximizing raspberry yield. Honey bees are typically used to pollinate commercial raspberry; however, escalating prices for hive rentals coupled with increasing acreage encourage evaluation of other manageable pollinators. Bumble bees (Bombus spp.) and several mason bees (Osmia spp.) are promising raspberry pollinators. Five bee species were evaluated and compared for their …

Using Anthropogenic Risks To Inform Salmonid Conservation At The Landscape Scale, Andrew W. Witt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The expansion and industrialization of humanity has caused many unforeseen consequences to the natural world. Due to the importance of freshwater for people, rivers have been particularly altered to meet human needs, often at the expense of the natural world. Supplying water for farms, industries, and cities has reshaped the natural state of rivers by altering river paths, chemistry, and species compositions. These changes have harmed many species that prospered before widespread human alterations, including the native trout and salmon of western North America. As human populations continue to grow, new threats will surface for rivers, and the trout and …

Impact Of Basal Diet On Obesity Phenotype Of Recipient Mice Following Fecal Microbiome Transfer From Obese Or Lean Human Donors, Daphne Michelle Rodriguez Jimenez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The composition of the gut microbiome can be affected by environmental factors, such as diet. The Western dietary pattern is associated with microbiome dysbiosis and adverse health outcomes, including obesity and metabolic disorders. The objective of this study was to examine the effect of gut microbiota from lean or obese human donors on metabolism and weight gain in recipient mice fed one of three basal diets: 1) the standard AIN93G diet, which promotes rodent health; 2) the total Western diet (TWD), which mimics the American dietary pattern and promotes inflammation-associated colorectal carcinogenesis; and 3) a 45% high fat diet-induced obesity …

Phenotypic Association Between Lactose And Other Milk Components In Western Us Dairy Herds And Japan, Takuji Asami

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lactose in milk has relatively low variation regardless of season, breed, or country. The study of lactose concentration and correlation among other milk components is limited. Furthermore, dairy farmers have limited access to the lactose data and are not familiar with it. This study was conducted to: 1) investigate the phenotypic correlation between lactose and other milk components; and 2) determine the importance of lactose for dairy herds.

Monthly DHIA records from Utah (DHIA), Dairy Herd Performance Test (DHTP) records from Ibaraki, Japan, and California herd average data (CHAD) covering 27 states were used to analyze the relationships between milk …

Assessment Of Microchimerism Following Somatic Cell Nuclear Transfer And Natural Pregnancies In Goats (Capra Aegagrus Hircus), Kirsten Karen Gash

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Somatic cell nuclear transfer (SCNT) is a powerful tool for production of transgenic animals for various biomedical and agricultural applications. For instance, our group is using SCNT to produce transgenic goats to study the role of cardiac fibrosis in initiation and progression of atrial fibrillation. There is a possibility of cell transfer from a transgenic fetus to its non-transgenic surrogate mother, known as fetal microchimerism; from a transgenic mother to non-transgenic fetus, maternal microchimerism and from a transgenic twin to non-transgenic twin in utero. Initially, we have assessed the presence of fetal microchimerism in tissue samples from non-transgenic surrogates …

Integrated Management Of Billbugs (Coleoptera: Dryophthoridae) In Intermountain West Turfgrass, Madeleine M. Dupuy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Billbugs are a serious pest of turfgrass in the Intermountain West. Billbug larvae severely discolor and eventually kill turfgrass by feeding in stems, on roots, and on crowns of the plant. Billbugs are typically managed with preventive, calendar-based applications of insecticides. Most of our knowledge on the biology and management of billbugs comes from research in the eastern U.S, and little is known about billbug biology and best management practices in the Intermountain West. First, I examined the seasonal activity of billbug life stages in Intermountain West turfgrass and developed a predictive degree-day model to better time management strategies against …

Effect Of Tannin-Containing Legume Hays On Enteric Methane Emissions And Nitrogen Partitioning In Beef Cattle, Elizabeth K. Stewart

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Cattle are responsible for greenhouse gas emissions such as carbon dioxide, methane and nitrous oxide. In particular, the cow-calf phase of production accounts for approximately 80 percent of the total beef production system greenhouse gas emissions. Tannins are chemical compounds found in certain forages and they have the potential to help reduce these negative environmental impacts. Thus, given that the cow-calf phase often relies on feeding hay, feeding tannin-containing hays may represent a significant mitigation practice.

With my MS program, I sought to explore whether tannin-containing hays fed to mother cows and heifers influence methane and nitrogen emissions relative to …

Patterns Of Threatened Vertebrates Based On Trophic Level, Diet, And Biogeography, Shaley A. Valentine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humans have indirectly and directly contributed to the extinction of over 500 species within the past 500 years, a rate far higher than we have seen in the past. The high extinction rate and the fact that 18% of vertebrates may become extinct within the next century have pushed Earth into a biodiversity crisis. Understanding what makes species more at risk of extinction is needed to protect Earth’s biodiversity.

Generally, it is expected that predators have greater extinction risk than omnivores and herbivores because predators are larger in body size, depend on other animal species for food, need large home …

Electron Flow And Management In Living Systems: Advancing Understanding Of Electron Transfer To Nitrogenase, Rhesa N. Ledbetter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen is a critical nutrient for growth and reproduction in living organisms. Although the Earth's atmosphere is composed of ~80% nitrogen gas (N₂), it is inaccessible to most living organisms in that form. Biological nitrogen fixation, however, can be performed by microbes that harbor the enzyme nitrogenase. This enzyme converts N₂ into bioavailable ammonia (NH₃) and accounts for at least half of the "fixed" nitrogen on the planet. The other major contributor to ammonia production is the industrial Haber-Bosch process. While the Haber-Bosch process has made significant advances in sustaining the global food supply through …

Incentivizing Fruit, Vegetable, And Physical Activity Level Change: Expansion And Evaluation Of The Fit Game Program For Healthy Behavior Change In Elementary Schools, Damon L. Joyner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Researchers in the Nutrition, Dietetics and Food Science department and Psychology department sought to improve healthy behaviors in elementary schools such as fruit and vegetable consumption (FV) and daily physical activity (PA). We chose to use a healthy behavior program called the “FIT Game” that has successfully increased FV consumption among elementary-aged children over short periods of time. Our aim was to improve the program by lowering operating costs, adjusting its materials to target PA and see if it could maintain healthy eating improvements over a longer period of time. Our series of research shows encouraging results: short term improvements …

Biological Condition And Stressors Of Blm Wadeable Streams In Northeastern California And Northwestern Nevada, Nicole Cappuccio

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Taxpayer dollars can be used more efficiently by land management agencies to monitor streams if agency-wide monitoring protocols are adopted. To address this issue, the Bureau of Land Management (BLM) developed the National Aquatic Monitoring Framework (NAMF) to implement standardized assessments of stream condition and trend in the Western United States. As one of the first applications of the NAMF I sought to develop and apply an analytical framework to determine the biological condition of streams, extent of instream stressors and their impact on biological condition, and anthropogenic sources of stressors in Northeast California and Northwest Nevada over three years …

U.S. Consumers’ Perception, Intention, And Purchase Behavior Of Grass-Fed Beef, Elizabeth K. Crandall

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research study was to compile regional profiles of the consumers who intend to consume grass-fed beef in the U.S. and to create marketing strategies that would assist producers in marketing their product to consumers. The researcher sent an online survey to a panel of 484 consumers across the U.S. to learn about their perceptions of and intention to purchase grass-fed beef.

Respondents had a weak, positive attitude toward purchasing grass-fed beef but had low knowledge of production practices. These consumers had a desire to eat healthier; however, they wanted meat that was priced right and had …

Pharmacologically Induced Meiosis Apomeiosis Interconversions In Boechera, Arabidopsis And Vigna, Lei Gao

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Apomixis is a clonal propagation method that produces offspring identical to the mother plant. With this feature, superior traits could be maintained over generations. However, our knowledge about apomixis is limited. In this study, we analyzed several apomictic Boechera embryologically to learn the details of apomixis. Meanwhile, we designed chemical treatments to successfully induce sex in apomictic plants and apomixis in sexual plants. Our experiments suggest that sex and apomixis coexist in plants and that sexual and apomictic reproduction are switchable by treating with specific chemicals.

The Effects Of Enhanced Flows On Community Structure And Ecosystem Functioning In A Montane Utah River System, Joshua A. Epperly

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to growing human demands for freshwater within the last century, manmade flow alterations are now a common characteristic of rivers worldwide. Alterations to the volume and timing of flows in rivers are known to negatively impact aquatic biodiversity, biological productivity and ecosystem functions such as nutrient cycling. While previous research has focused on the effects of flow reductions and spates, there is a lack of knowledge on how high flows across longer timespans (i.e. ‘enhanced flows’) impact the structure of river communities and the integrity of ecosystem functions.

The Utah Reclamation, Mitigation and Conservation Commission has expressed interest in …

Development And Characterization Of Reporter-Expressing Zika Viruses, Michael E. Woolley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, Zika virus (ZIKV) has garnered worldwide attention due to its epidemic spread throughout the Americas and due to the newly recognized link between ZIKV infection and neurological diseases, including microcephaly and Guillain-Barré syndrome. ZIKV is a mosquito-borne member of the genus Flavivirus, which includes the other prominent human pathogens Japanese encephalitis virus, West Nile virus, dengue virus, and yellow fever virus. Many questions about the biology of ZIKV and how it causes disease remain unanswered. Furthermore, there currently are no vaccines or licensed antiviral drugs available to treat ZIKV infection. The goal of this study was to …

Invasive Phragmites Australis Management In Great Salt Lake Wetlands: Context Dependency And Scale Effects On Vegetation And Seed Banks, Christine B. Rohal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive plants can outcompete native plants, replacing diverse plant communities with monocultures, which can negatively impact the whole ecosystem. One invasive plant, Phragmites australis, has invaded wetlands across North America. In Utah’s Great Salt Lake, it has greatly reduced the area of native plants that are important habitat for migratory birds. Here we describe experiments that assess multiple treatments for Phragmites removal and evaluate the return of native plants after Phragmites management. The treatments were applied to Phragmites patches at two scales (small 1/4-acre plots and large 3-acre plots) and across multiple sites to evaluate how patch size and …

Land Cover And Use Change In Utah: A Comparison Of Field- Vs. Aerial Image-Based Observations, Jennifer Lynn Bakken

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Image-based Change Estimation program (ICE) was developed by the US Forest Service Forest Inventory & Analysis (FIA) program and the Geospatial Technology Applications Center in response to the 2014 Farm Bill calling for more timely and accurate estimates of land cover and use change. ICE monitors change throughout the US on a state by state basis by assessing each FIA plot using high resolution imagery from two dates in time. In the western US, FIA measures 10% of the plots each year to report on status, trends, and sustainability of our Nation’s forests. However, this 10 year cycle misses …

Effects Of Livestock Grazing Management Practices On Greater Sage-Grouse Nest And Female Survival, Seth J. Dettenmaier

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The decline in greater sage-grouse (Centrocercus urophasianus; sage-grouse) populations across western North America has been primarily attributed to loss and fragmentation of their sagebrush (Artemisia spp.) habitats. This habitat loss is largely the result of increased human activities, with grazing by domestic livestock as the most predominant land use across the sagebrush ecosystem in North America. The goal of my research was to increase our understanding of the effects of livestock on sage-grouse populations. I reviewed the peer-reviewed literature for all published studies that reported potential effects of grazing on grouse species worldwide. I found that there …

Development And Fitness Consequences Of Onshore Behavior Among Polar Bears In The Southern Beaufort Sea Subpopulation, Kate M. Lillie

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed onshore during late summer and early fall has increased considerably. Previous research suggests that the number of polar bears onshore is linked to sea ice conditions and the availability of subsistence-harvested whale carcasses, which are referred to as bone piles. My objectives were to determine the development …

Enhancing Spider-Silk Protein Materials Through Continuous Electrospinning And Photo-Initiated Cross-Linking, Dan Gil

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider-silk is known as one of the stronger natural materials, unfortunately it is impossible to farm spiders due to their territorial and cannibalistic nature. To address this issue, researchers have studied spider-silk to discover how it is produced in nature. From their results, spider-silk is composed of large sized proteins produced in two different cell types. Using this knowledge, researchers created transgenic organisms capable of producing spider-silk proteins in large quantities. Using these proteins, several groups have created fibers, films, hydrogels, and adhesives with robust and versatile properties.

Wet-spinning is a technique commonly used to create fibers from spider-silk proteins. …

Growth Characteristics Of Lactobacillus Wasatchensis And Its Detection And Enumeration Using Quantitative Polymerase Chain Reaction, Isaac Brockbank Bowen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

There are numerous challenges encountered during the manufacturing and storage of cheese by both the large-scale and artesian producers. One such challenge has been the formation of late gassy defect, which occurs when gas is produced by certain lactic acid bacteria found in the cheese block during storage and aging over a three month time period. Negative consequences of late gas production are slits and cracks in the cheese block and puffy cheese packaging, which cause significant financial losses for manufacturers along with poor consumer acceptance.

Lactobacillus wasatchensis is one such lactic acid bacterium shown to produce gas during cheese …

Evaluation Of Therapeutics For An Enterovirus 71 Infection In An Ag129 Mouse Model, Christopher Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Discovered in 1969 in California, enterovirus 71 (EV-71) is a serious cause of disease in young children. It is one of the major causative agents of hand, food, and mouth disease (HFMD), and can produce neurological complications, such as meningitis, encephalitis, and an acute flaccid paralysis. For serious cases, the fatality rate can be up to 26%, almost exclusively in young children.

While the virus was initially discovered in the United States, it was soon detected in the Eastern hemisphere, causing outbreaks in Europe and Asia. The largest outbreak occurred in Taiwan in 2008, with approximately 490,000 cases and 128 …

Silage Corn Hybrid Response To Row Width And Plant Density In The Intermountain West, Mark A. Pieper

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Corn (Zea mays L.) hectarage has increased rapidly in Utah and Idaho in recent years due to expansion of the dairy industry, but little is known about corn production practices that optimize yield and quality of silage corn in semi-arid irrigated cropping systems. The objective of this study was to determine the dry matter yield and quality effects of corn hybrids grown in different plant densities and row widths in the Intermountain West. Field experiments were conducted under irrigation in 2015 and 2016 at locations near North Logan, Utah and Jerome, Idaho. The experimental design was a randomized complete …

Managing For Multiple Objectives In Southwestern Forests: Evaluating The Trade-Offs Between Enhancing Mexican Spotted Owl Nest Habitat And Mitigating Potential Crown Fire, Daniel C. Deane Mckenna

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Forest Inventory and Analysis (FIA), the United States’ forest census, measured sixty-six Mexican spotted owl nest stands in order gain insight into the structure and composition of the nest habitat of this threatened species. I used these data, along with the greater FIA database and the Forest Vegetation Simulator to explore questions surrounding the management of Mexican spotted owl habitat, specifically how to balance the objective of sustaining and enhancing nest habitat in face of increasing forest fire size and severity in the Southwest. My research consisted of three studies. The first study quantified the structure and composition of …

Characterization Of Black Walnut Genotypes For Resistance To Thousand Cankers Disease, Frost Hardiness And Other Desirable Horticultural Traits, J. Elisa Lauritzen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The black walnut, Juglans nigra L., is native to the United States (USA) and is a valuable timber and nut tree. Just before the beginning of the 21st century, several western states observed a decline in the health and, later, death of black walnut trees. The pathogen-vector complex now known as thousand cankers disease (TCD) was shown to be the cause. The disease, caused by Geosmithia morbida Kolařik, is vectored by the walnut twig beetle (WTB), Pityophthorus juglandis Blackman. Thousands of WTB will swarm and enter a tree vectoring the fungus at each entry point where cankers then develop, quickly …

The Influence Of Multiyear Drought-Driven Habitat Loss On The Bear Lake Sculpin (Cottus Extensus) And The Bear Lake Strain Of The Bonneville Cutthroat Trout (Oncorhynchus Clarkii Utah), Hayley C. Glassic

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multiyear drought is expected to increase in occurrence and severity in dry regions across the world, such as the American Southwest, endangering native species and ecosystem health. The effects of multiyear drought are often worsened by human water use for consumption, energy production, and agriculture, which, in lakes and reservoirs, cause reduced lake elevation. Reductions in lake elevation may leave previously submerged habitat stranded along shorelines and make tributaries inaccessible to fishes. Here, we show that decreasing lake elevation, associated with drought and water withdrawal, reduces the availability of shoreline cobble habitat to fishes and increases tributary distance by creating …