Life Sciences Commons^™

Evaluating Utah 4-H Stem Curricula Used To Promote Stem In Utah 4-H Programs, Michelle D. Simmons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utah 4-H strives to ensure that youth receive the best that positive youth developmental programming has to offer in an endeavor to provide 4-H youth with the knowledge and skills that will given them an advantage in the workforce. The purpose of this study was to determine if Utah's Discover 4-H STEM curricula that is being used to promote STEM in Utah 4-H program met the outcomes of the National 4-H STEM logic model.

A Comparison Of Five Statistical Methods For Predicting Stream Temperature Across Stream Networks, Maike F. Holthuijzen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The health of freshwater aquatic systems, particularly stream networks, is mainly influenced by water temperature, which controls biological processes and influences species distributions and aquatic biodiversity. Thermal regimes of rivers are likely to change in the future, due to climate change and other anthropogenic impacts, and our ability to predict stream temperatures will be critical in understanding distribution shifts of aquatic biota. Spatial statistical network models take into account spatial relationships but have drawbacks, including high computation times and data pre-processing requirements. Machine learning techniques and generalized additive models (GAM) are promising alternatives to the SSN model. Two machine learning …

Understanding The Biology Of Clover Root Curculio And Improving Their Management Using Biofumigation In Alfalfa, Steven J. Price

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Clover root curculio (CRC) is a pest of alfalfa where larvae feed belowground damaging alfalfa roots. Regional knowledge of CRC activity and biology is limited making the development of pest management strategies difficult. One potential management technique for soil-dwelling pests is the use of biofumigant containing cover crops. Biofumigation can affect the survival and behavior of pest insects. However, biofumigant crops have not been evaluated against CRC or as a rotational crop compatible with alfalfa. The goals of this research were to determine 1) phenology, population sizes, and root damage severity of CRC occurring in the Intermountain region and 2) …

Natural And Anthropogenic Effects On Life History Characteristics In The Side-Blotched Lizard (Uta Stansburiana), Geoffrey David Stuart Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Survival is a prerequisite for successful reproduction, and is thus intertwined with fitness. Some physiological systems can improve survival, like the immune system, but compete with other processes for resources. Because animals evolved with resource limitation, it is important to understand how these resource-allocation decisions are made. To meet this end, I performed four investigations addressing how life-history characteristics shift in side-blotched lizards (Uta stansburiana) using laboratory studies and multi-year field sampling. First, I measured metabolic rates in response to different immune challenges and different energy states in male lizards. I found that, surprisingly, cutaneous biopsies were associated …

Integrating Black Bear Behavior, Spatial Ecology, And Population Dynamics In A Human-Dominated Landscape: Implications For Management, Jarod D. Raithel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The American black bear (Ursus americanus) has made a robust recovery within the human-dominated, social-ecological systems characterizing the Mid-Atlantic United
States. For example, in northwestern New Jersey (NJ), USA, black bear abundance increased from an estimated 450-500 in 1996 to 3200-3400 in 2010. Bear recovery
coincided with increasing human populations, coupled with shifting settlement patterns toward sprawling suburban communities. Consequently, conflicts have rapidly proliferated over the past three decades and resulted in >1400 incidents of verified property damage, >400 livestock kills, >250 pet attacks and/or kills, seven human attacks and one human fatality since 2001. The New Jersey …

Bridging Post-Wildfire Communication Gaps Between Managers, Researchers, And Local Communities, Including A Biological Soil Crust Case Study, Hilary Louise Whitcomb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Immediately after a wildfire land managers act quickly to protect water supplies, soil stability, habitat, and forage. We don't currently understand how managers make trade-off decisions between social, political, and ecological factors in these tight timelines or if they are able to use new science. We do know ecosystems often benefit from local engagement, and new, scientifically-grounded methods that improve restoration efforts are needed. As post-wildfire timelines don’t often allow for outside input, I asked managers what they and stakeholders think about post-wildfire projects and what managers think about new science. I asked local citizens what they think about postwildfire …

Seasonal Development Of The Biological Control Agent Of Dalmatian Toadflax, Mecinus Janthiniformis (Curculionidae: Coleoptera), In Utah: Phenology, Overwintering Success, And Mortality, Samantha A. Willden

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

By outcompeting desirable vegetation, invasive weeds can dominate field crops and rangelands, drastically reducing yield and land value. One option in controlling the impact and spread of such weeds is reuniting them with their natural insect herbivores, a process called biological control. When successful, biocontrol can be the cheapest way to provide long-term control of invasive weeds, but continual monitoring of insect and weed activity is required to ensure success.

Dalmatian toadflax is an invasive weed that occurs widely throughout the northwestern U.S., and that is spreading south each year to warmer and drier regions, including sites in Utah. Although …

The Role Of Utah Farmers In Farm To School Programming, John L. Hawley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This purpose of this study was to describe Utah farmers’ role in farm to school (FTS) programming and their interest in institutional marketing of local foods. The researcher sent a survey to farmers belonging to the Utah Farm Bureau to discover the role they play in FTS in Utah.

Respondents held positive attitudes toward FTS programming and agreed that building relationships with community members and increasing awareness of local food were benefits. They cited a lack of information about schools seeking to purchase local products and restriction of growing seasons as barriers to their participation in FTS. They displayed their …

Maternal Diabetes, Related Biomarkers And Genes, And Risk Of Orofacial Clefts, Tiwaporn Maneerattanasuporn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Orofacial clefts (OFCs) are among the most common congenital birth defects and are characterized by incomplete development of the lip or the palate or both. The lip and palate develop separately at different times during the first trimester of pregnancy. The etiology of OFCs is multifactorial and includes a combination of genetic and environmental factors. This project aims to examine role of maternal diabetes mellitus in orofacial clefts through studies of medical histories, biomarkers, and genes.

In a study of Utah birth certificates, mothers with pre-existing diabetes and gestational diabetes mellitus (GDM) had an increased risk of OFCs, and obese …

Using Silkworms As A Host To Spin Spider Silk-Like Fibers, Xiaoli Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Using silkworms as the potential host to spin spider silk-like fibers is an area of intense research world-wide. The conventional methods used to create transgenic silkworms hosting spider silk-like gene limits the incorporation of spider silk-like protein and do not improve the mechanical performance of the composite silkworm/spider silk fibers. In this dissertation, synthetic spider ampullate genes were incorporated into the precise site of the fibroin heavy chain or light chain using the latest genome editing technology CRISPR/cas9 guided non-homologous end joining as opposed to conventional random integration using transposon-based piggyBac system. These protocols, with extensive applicability to other silkworm …

Comparison Of Chikungunya Virus Strains In Disease Severity And Susceptibility To T-705 (Favipiravir), In Vitro And In Vivo, Makda Gebre

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chikungunya is a mosquito-transmitted disease caused by Chikungunya virus (CHIKV). Symptoms of Chikungunya include debilitating joint pain and swelling, fever and rash. CHIKV was first discovered in 1953 in Tanzania, and has since caused periodic outbreaks of disease. The virus reemerged recently in 2004 and has since spread around the world affecting more than 3 million people. The different strains of CHIKV have been grouped into three phylogenetic clades: West African, Asian and East/Central/South African (ECSA). There are no FDA approved medicines or vaccines used to treat or prevent CHIKV infection. The antiviral drug, T-705 (commercially known as Favipiravir), has …

Evaluating Habitat-Based Niche Requirements And Potential Recruitment Bottlenecks For Imperiled Bluehead Sucker (Catostomus Discobolus), Bryan C. Maloney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes to rivers that alter physical and thermal habitat may cause fish population abundance to decline, due to fewer individuals maturing and entering the adult population. The Weber River has become highly degraded with many dams and diversions altering fish habitat, river volume, velocity, and temperature, and limiting movement between reaches. Bluehead suckers (Catostomus discobolus) occupy only 47% of their historical range and the genetically-distinct Weber River (northern UT) population is declining and contains few young, juvenile fish. My objectives were to determine whether spawning and rearing habitat available in the Weber River may be limiting bluehead sucker …

Great Basin Bristlecone Pine Resistance To Mountain Pine Beetle: An Evaluation Of Dendroctonus Ponderosae Host Selection Behavior And Reproductive Success In Pinus Longaeva, Erika L. Eidson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mountain pine beetle (Dendroctonus ponderosae) is a native bark beetle that attacks and kills most species of pines (Pinus) throughout its range in western North America. Due to the strong relationship between thermal conditions and mountain pine beetle population success, climate change-induced changes in mountain pine beetle outbreaks are a major concern for land managers. Over the past several decades, warmer than average temperatures allowed mountain pine beetle populations to reach epidemic levels across much of the western U.S. and Canada, including high elevations where outbreaks were previously limited by cool temperatures. Many high-elevation pine …

Intentional Mentoring Through 4-H: The Role Of 4-H In A Successful Mentoring Program Between Youth And Adults, Emily Ann Shepperd

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

4-H Youth and Families with Promise (4-H YFP) is a one to one youth mentoring program that aims to help youth obtain skills that will help them to be successful. The purpose of this research was to determine if any positive outcomes were shown of youth participating in 4-H YFP. Positive outcomes were identified as peer social competence, greater ability to make positive choices, the development of effective communication skills, building connections, and contributing to the community. Results show that these outcomes positively increased among youth participants in the 4-H YFP program- but the changes were too small to be …

Foraging Ecology Of Mountain Lions In The Sierra National Forest, California, Bradley C. Nichols

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We conducted this research to gain insight into mountain lion (Puma concolor) prey composition in the Sierra National Forest of California. Managers in the region are concerned with both causes of declines and inability to increase fisher (Pekania pennanti) populations. Research has shown that mountain lions are a threat to fishers due to direct predation of this forest specialist. We radio-collared 5 adult mountain lions in order to determine prey composition and kill rates. As expected, mountain lions selected primarily for mule deer (Odocoileus hemionus). However we did detect other prey such as gray …

Sclerocactus Wetlandicus: Habitat Characterization, Seed Germination And Mycorrhizal Analysis, Kourtney T. Harding

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Uinta Basin hookless cactus (Sclerocactus wetlandicus) is a threatened species native to Eastern Utah. The cactus is found in a landscape highly disturbed by non-renewable energy production. To understand the environmental conditions that support natural growth of this cactus, we asked what types of plants were present in the same areas as the cactus, and if the types of plants were different in environments that were disturbed. From our assessment, we determined that the types of plants present in disturbed areas were drastically different from those present in undisturbed locations. Areas previously used for energy production are …

Effect Of Foliage And Root Carbon Quantity, Quality, And Fluxes On Soil Organic Carbon Stabilization In Montane Aspen And Conifer Stands In Utah, Antra Boča

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic carbon (SOC) positively affects many soil properties (e.g., fertility and water holding capacity), and the amount of carbon (C) in soil exceeds the amount in the atmosphere by about three times. Forest soils store as much C as is found in trees. Tree species differ in their effect on SOC pools. Quaking aspen forests in the Western US often store more stable SOC in the mineral soil than nearby conifers. During the last decades a decline in aspen cover, often followed by conifer encroachment, has been documented. A shift from aspen to conifer overstories may negatively affect the …

Comparison Of Beef Flavor Compounds From Steaks And Ground Patties Of Three Usda Quality Grades And Varied Degrees Of Doneness, Kourtney Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to determine how quality grade (Prime, Low Choice, and Standard) and degree of doneness (4, 25, 55, 60, 71, and 77°C) influence the development of the flavor-producing compounds in beef whole muscle and ground patties. The content and type of many compounds influence beef flavor, including: proximate composition, pH, neutral and polar lipid fatty acids, free and total amino acids, reducing sugars, and volatile compounds, in addition to cooking duration. The important proximate components include fat, moisture, and protein content. Amino acids and reducing sugars alone contribute to the five basic tastes, but they …

Effects Of Changing Environments On Survival Of A Widely Distributed Ungulate, S Andrew Sims

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wildlife species distributed over large areas of land inhabiting varying environments are experiencing shifts in their home ranges due to human expansion and climate change. As these species home ranges shifts out of familiar, critical habitat they are forced to interact with novel environments, which in turn affects the species population demographics. In order to manage and conserve these species accordingly, specifically in a time of large-scale change, it is imperative that we add to current understandings of how they interact with various environments. Furthermore, frequently generating short-term predictions of demographic drivers will allow for conservation and management insight that …

Increasing Student Engagement And Knowledge Retention In An Entry-Level General Nutrition Course With Technology And Innovative Use Of A Graduate-Level Teaching Assistant, Minhee Kang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Blended-design courses integrate both face-to-face and online learning. This thesis discusses the use of three teaching innovations and their effect on student engagement and course satisfaction in a blended-design nutrition course. The three teaching innovations include 1) a web-based learning platform, called Connect (published by McGraw-Hill Education) 2) other easily accessible technological tools (such as Google+), and 3) higher-level use of a graduate-level teaching assistant.

Another form of web-based learning platform, Mastering, published by Pearson Education, was use previously in the course. However, students, especially those earning the highest grades in the course, did not see value in completing these …

Understanding The Mechanisms Of Insecticide Resistance In Phlebotomus Papatasi And Lutzoymia Longipalpis Sand Flies (Diptera: Psychodidae: Phlebotominae), David Denlinger

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Sand flies, like mosquitoes, ticks, fleas, and lice, transmit pathogens that cause disease in humans. Leishmaniasis, caused by pathogens transmitted by sand flies, kills tens of thousands of people every year. Insecticides have been used to control sand flies, but there is evidence of insecticide resistance in populations of sand flies around the world. The goal of this dissertation was to develop tools to maintain sand flies in the laboratory, develop the ability to identify insecticide-resistant populations of sand flies, and to investigate the genetic mechanisms of how sand flies become resistant to insecticides. I began by comparing live animal …

Effects Of Gestational Dietary Intake On Calf Growth And Early Feedlot Performance Of Offspring, Jose M. Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fetal programming is a relatively new and quickly growing field of research in the livestock industry. The concept of fetal programming is simply defined as the effects a change in maternal nutritional intake has on offspring, whether it be a genetic or physical change. The intention of this study was to specifically look at the effects of nutrient restriction of cows during the second trimester of gestation on the growth and performance of the resulting calves.

In this study, thirty-two cows of predominantly angus influence from the Utah state university herd were chosen, naturally bred to a pure bred angus …

Precision Drought Stress In Orchards: Rootstock Evaluation, Trunk Hydration And Canopy Temperature, Lance V. Stott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tree fruit crops are of high value, but use a lot of water. Precision irrigation has the potential to save water while simultaneously improving crop quality. The timing and method of precision water stress in various tree fruit crops has been widely studied. However, in order to successfully employ precision irrigation methods in orchards, an accurate measurement of tree water status is required. Currently, stem water potential is the preferred indicator. However, this measurement is tedious and cannot be automated. Because measurements must be taken near solar noon (approximately 1:30 PM MDT in the summer in northern Utah), the number …

The Role Of The Fatty Acid Signaling Pathway In Dietary-Induced Obesity, Melissa N. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In recent years, dietary fat has been shown to be capable of activing taste receptor cells in the tongue. Fatty acids (FAs), which act as the chemical cue and are found in dietary fat, activate a cellular signaling pathway that results in a unique signal being sent to the brain that is then interpreted as the taste of fat. One important element in this pathway is the ion channel TrpM5. It is responsible for depolarizing the taste cells that are activated by fatty acids; depolarization is an essential step in cellular response, making TrpM5 essential in the functioning of the …

Analysis Of Beef Steaks Of Varying Usda Quality Grades And Thicknesses Cooked On Low And High Grill Surface Temperatures, Tonirae Gardner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this project was to analyze the thermodynamics (thermal conductivity and diffusivity as well as protein denaturation) and physical properties (percent expressible moisture, cooking loss, change in steak thickness, shear force, texture profile analysis and rheological behavior) of beef steaks of different USDA quality grades (Upper 2/3 Choice and Select), thicknesses (thick and thin), and grill surface temperatures (high and low) cooked to the same internal degree of doneness to determine if a specific set of cooking parameters would create a profound difference in the eating characteristics, described by the tenderness and juiciness of cooked beef strip steaks. …

The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …

First-Row Transition Metal Sulfides And Phosphides As Competent Electrocatalysts For Water Splitting, Nan Jiang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solar energy is a carbon-neutral and renewable energy resource. Its nature of intermittence and unequal distribution requires efficient solar energy capture, conversion, and storage. Solar-driven water splitting to produce hydrogen and oxygen is widely considered as an appealing approach to meet this goal, in which hydrogen acts as a green energy carrier. Water splitting consists of two redox half reactions: hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Both reactions involve the transfer of multiple electrons and protons and possess high energy barriers to proceed at appreciable rates, hence catalysts are needed.

A large number of HER and OER …

Strategies For Increased Lactic Acid Production From Algal Cake Fermentations At Low Ph By Lactobacillus Casei, Tom J. Overbeck

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We explored using de-oiled algal biomass (algal cake) as a low-value substrate for production of lactic acid in fermentations with Lactobacillus casei, and strategies for increasing lactic acid production at low pH. L. casei 12A algal cake (AC) fermentations showed carbohydrate and amino acid availability limit growth and lactic acid production. These nutritional requirements were effectively addressed with enzymatic hydrolysis of the AC using α-amylase, cellulase, and pepsin. Producing 0.075 g lactic acid per g AC from AC digested with all three enzymes. We explored heterologous expression of the cellulase gene (celE) from Clostridium thermocellum and the …

To What Extent Might Beaver Dam Building Buffer Water Storage Losses Associated With A Declining Snowpack?, Konrad Hafen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Dams built by North American Beaver create natural water storage and slow water as it moves through streams. In portions of streams with beaver dams, these effects have been observed to decrease the peak magnitude of floods and increase base flow during annual summer droughts. In the western United States changes to streamflow patterns have been observed in recent decades with large spring floods coming earlier in the year, causing annual summer droughts to start earlier and last longer. These changes are linked to decreasing snowpack which acts as the most significant natural water storage reservoir by holding onto precipitation …

Impact Of Climate Variability On The Frequency And Severity Of Ecological Disturbances In Great Basin Bristlecone Pine Sky Island Ecosystems, Curtis A. Gray

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Many high elevation conifer species, including high elevation five needle pines, are declining throughout western North America. Warming temperatures, mountain pine beetle, white pine blister rust and alteration of naturally occurring fire regimes represent an interactive set of circumstances leading to greater risk. The loss of these treeline pines can detrimentally impact biodiversity and valuable ecosystem services including wildlife habitat, watershed and soil protection, aesthetics and recreation. Great Basin bristlecone pine ecosystems are naturally highly fragmented because of their elevational requirements. However, they may become even more fragmented due to combined impacts of warming temperature, insects and diseases listed above. …