Life Sciences Commons^™

Nutrient Leaching Under Traditional And Intercropped Cover Crop Fields In Northern Utah, Katherine Hewitt

All Graduate Theses and Dissertations, Fall 2023 to Present

This study examines whether cover crops can be used in Utah and the Intermountain West to improve water quality and reduce contamination due to nutrient leaching from agricultural soils into the groundwater. Cover crops such as grasses, clover, and other seed mixtures can be planted to improve soil health, increasing the soil’s ability to retain water and nutrients, which reduces the amount of nitrate and phosphate fertilizers lost through leaching and contamination. In Utah, short growing seasons and limited irrigation water availability hinder the ability to establish cover crops. By planting the cover crop between the rows (intercropping) when the …

Microbes In Pollination Systems: Effects On Pollinator Health, Floral Traits, Nectar Robbing, And Plant Fitness, Valerie Nicole Martin

All Graduate Theses and Dissertations, Fall 2023 to Present

Flowers produce nectar to attract pollinators, but nectar is also a habitat for yeasts and bacteria that arrive via pollinators, robbers, and other visitors. These microbes consume nectar sugars and release byproducts that change the smell and taste of nectar. Whether these changes affect how pollinators find and choose flowers, and whether they ultimately affect how many seeds a plant produces, is not well understood. In this dissertation, I studied how a common nectar yeast and a plant-associated bacterium affect the scent of wildflowers, the behavior of bumble bees and hummingbirds, and plant reproduction in montane meadows in central Colorado. …

Integrative Taxonomic Analysis Of Cryptic Species Diversity In The Spiny Witch-Hazel Gall Aphid, Hamamelistes Spinosus (Hemiptera: Aphididae: Hormaphidini) In Eastern North America, Gavin Andrew Powell Munson

All Graduate Theses and Dissertations, Fall 2023 to Present

Taxonomy is the practice of identifying, classifying and categorizing species, providing structure for the vast diversity of life. Aphids are an ecologically important group of soft-bodied insects, but they can be difficult to identify because of their tiny anatomical size, reduced or simplified morphological features, and morphological variation within a single species across different generations. In this study, the taxonomy of the spiny witch-hazel gall aphid, Hamamelistes spinosus, is revised. The complex multi-generational life cycle of the aphids, which alternates between witch-hazel and birch trees, has led to confusion regarding past descriptions. Scientists in the late 1800s who were …

The Role Of Phenotypic Plasticity And Bet-Hedging In Coping With Unpredictable Temperature Fluctuations In The Marine Annelid Ophryotrocha Labronica, Gabrielle Dawn Newton

Biological Sciences Theses & Dissertations

Coastal ecosystems are increasingly exposed to unpredictable temperature fluctuations, potentially favoring strategies that buffer populations against environmental uncertainty. This study examines how phenotypic plasticity and diversified bet-hedging contribute to variation in life-history traits under differing thermal predictability in the marine annelid Ophryotrocha labronica. After three generations at 24 °C, broods were reared for three generations under four thermal regimes: constant 24 °C (C24), constant 27 °C (C27), predictable fluctuations (Fp), and unpredictable fluctuations (Fu). Survival was assessed before and after acclimation to evaluate selective pressure among regimes. Age at maturity, fecundity, and growth rate were used to quantify plasticity (trait …

Menopausal Symptoms, Psychosocial Factors, And Physical Activity Among Physically Active Midlife Females, Ella Onsoriasl

Exercise Science Theses & Dissertations

Menopausal symptoms are common during midlife and may be associated with females' physical activity (PA) participation, yet how these symptoms relate to PA levels, perceived confidence and enjoyment, and psychosocial resources such as social support (SS), exercise identity, and quality of life (QOL) remains unclear. The purpose of this study was to examine how menopausal symptom severity relates to PA levels, perceived confidence and enjoyment during PA, and psychosocial factors, including SS, exercise identity, and QOL. This cross-sectional study surveyed 151 midlife females aged 40 to 60 who reported engaging in intentional PA at least once per week. Participants completed …

Time-Frequency Analysis Of Arterial Pulse Signals Of Cardiovascular Disease Patients Measured By A Microfluidic-Based Tactile Sensor, Md Mahfuzur Rahman

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents a single-degree-of-freedom (SDOF) based time–frequency analysis framework that can simultaneously extract a comprehensive set of cardiovascular autonomic indices from arterial pulse wave recordings obtained at rest and post-exercise, supporting non-invasive monitoring of autonomic recovery during cardiac rehabilitation. The framework rests on three technical contributions.

First, an SDOF analytical model of motion artefacts quantifies two physically distinct distortion mechanisms: additive baseline drift and Time-Varying System Parameter (TVSP) generated distortion of the Tissue-Contact-Sensor (TCS) stack. Baseline drift is slowly varying and removable by filtering; TVSP distortion rides on all harmonics of the true pulse signal and cannot be removed …

Pre-Post Changes In Physiological, Cognitive, And Motivational Outcomes Following An Active Video Game Intervention In Adolescents And Adults: A Pilot Study, Ashley Williams, Danielle D. Wadsworth, Thaangiah Geetha

Publications

Active video games (AVG) are emerging as a promising home-based strategy to increase physical activity by integrating movement into interactive gameplay. However, evidence remains limited regarding their effectiveness across physiological, cognitive, and motivational outcomes in adolescents and adults within household settings.

Effects Of Photosynthetic Mode On Growth In Closely Related Tillandsia Species, Jeremy L. Read

Electronic Theses, Projects, and Dissertations

To examine the effects of photosynthetic mode (C3 vs CAM) on plant productivity, subjects of the sister taxa Tillandsia confertiflora (a C3 species) and Tillandsia latifolia (a CAM species) were grown under controlled conditions via growth chamber over 30 weeks. These subjects were divided into non-stressed and drought stress groups. Subjects were compared for total biomass gained or lost over the time period as well as physiological stress measures and CAM activity. The primary conclusion is that usage of CAM does not show major differences or tradeoffs for overall productivity. Future work is needed to clarify if this holds true …

A Comparison Of Survival, Growth, And Stress Resilience In Three Different Lineages Of The Pacific Oyster (Crassostrea Gigas) Farmed On The California Central Coast, Victoria F. Hanshaw

Master's Theses

Aquaculture of Pacific oysters on the US West Coast is routinely impacted by seasonal unexplained mortality events. To better understand these large-scale mortality events in oyster aquaculture, shellfish growers and scientists in California have partnered together to conduct comparative, multi-estuary farm trials of discrete Pacific oyster (Crassostrea gigas) lineages. In this thesis we investigate how the more recently imported Midori lineage performs compared to the historically used Miyagi lineage, as well as a Hybrid (Midori x Miyagi) lineage. As part of a 7-month long field study from April-November of 2024 in Morro Bay and Tomales Bay, California, we evaluated …

The Effect Of Specialty Malt On Dry-Hopping, Alexander Kivela

Master's Theses

Dry-Hopping is a modern and ever-increasing method to add hoppy flavors to beer. This is typically seen in pale ales and India Pale Ales (IPA’s). Most research has investigated the effect of dry-hopping only using pale malt, whereas most breweries used specialty malts to create a malty backbone to their beer.

The objectives of this research were to analyze the impact of specialty malts and their concentration on the efficacy of hop flavor and extraction, determined via gas chromatography and sensory analysis. Gas chromatography analysis was modeled after the ASBC Method Beer-48. Sensory analysis was performed via the 15cm line …

Comparative Assessment Of Developmental Fidelity In Hpsc-Derived Neural Crest Cells, Michael H. Zepeda

Electronic Theses, Projects, and Dissertations

Neural crest cells (NCCs) are a transient, multipotent cell population that contributes to craniofacial structures, peripheral neurons, melanocytes, and smooth muscle. Defects in NCC development underlie a broad range of congenital disorders known as neurocristopathies. Human pluripotent stem cell (hPSC)-derived NCCs provide an evaluable model for studying early human development; however, existing differentiation protocols produce variable outcomes, and no standardized method consistently generates high-fidelity NCC populations. To address this challenge, we compared five published hPSC-to-NCC differentiation protocols using the H9 human embryonic stem cell line. We hypothesized that specific protocols more faithfully recapitulate neural crest development through coordinated regulation of …

Analyses Of Atheroprotective Effects From Mir-33a Deletion In Primary Vascular Smooth Muscle Cells, Achala Pokhrel

All Theses

Atherosclerosis is one of the major causes of cardiovascular disease, characterized by the accumulation of cholesterol and foam cells within the arterial walls. Foam cells were traditionally believed to originate from macrophages; however, recent studies have shown vascular smooth muscle cells are also capable of accumulating cholesterol and developing foam-cell-like characteristics. ATP-binding cassette transporter A1 (ABCA1) plays an important role in removing excess cholesterol from cells by transporting intracellular cholesterol to circulatory apolipoprotein A-I (apoAI). MicroRNA-33a (miR-33a) is known to suppress ABCA1 expression and limit cholesterol efflux. However, its role in primary aortic smooth muscle cells is unknown and not …

The Aggregation Of Microplastics By Enhancing Extracellular Polymeric Substance Production In Pseudoalteromonas Sp. Ncimb 2021 To Improve Removal Efficiencies In Environmental Matrices, Janelle L. Mercer

All Theses

Microplastics (MP) are ubiquitous in the natural environment and are a growing threat due to their small size and durability. Plastics are released into the environment through improper waste management, wastewater treatment outfalls, industrial spills, agricultural runoff, and landfills. These particles breakdown into secondary MP through degradation pathways. MP, less than 5 mm, require intricate removal techniques from water systems. Filtration techniques, though viable and effective, have implementation constraints due to high cost, maintenance demands, and filter fouling. By integrating coagulation and flocculation processes prior to filtration, MP removal efficiencies can increase, while minimizing operational challenges during filtration. Extracellular polymeric …

Function And Regulation Of Long Polar Fimbriae During Enterohemorrhagic Escherichia Coli Infection, Walter J. Galdamez

Dissertations and Theses (Open Access)

Enterohemorrhagic Escherichia coli (EHEC) is a foodborne pathogen that causes severe gastrointestinal disease and hemolytic uremic syndrome. EHEC employs multiple virulence factors to colonize the host intestine, including the locus of enterocyte effacement (LEE) encoded type III secretion system, intimin, and flagella, yet the role of long polar fimbriae (Lpf) in adhesions and infection remains less well understood. Long polar fimbriae can mediate bacterial attachment to host cells in vitro, yet the regulation and function of its two fimbrial operons, lpf1 and lpf2 in vivo remain poorly understood. Preliminary RNA-seq data from zebrafish infected with EHEC reveal that expression of …

Silviculture For Coastal Forest Resilience: Promoting Forest Regeneration And Managing Invasive Plant Species, Ryan Bohannon

All Dissertations

Coastal forests of the southern United States and the ecosystem services they provide are threatened by an intensifying and interacting suite of disturbances associated with global change. Silvicultural strategies such as enrichment planting, invasive plant management, and browse mitigation treatments can enhance the resilience and adaptive capacity of forests to these threats by promoting sustainable regeneration and recruitment dynamics. To improve our understanding of coastal forest disturbance regimes and their impacts on forest stand dynamics, I conducted a systematic literature review of maritime forest disturbance ecology and identified coastal storms, ungulate browsing pressure, and invasive plants as primary disturbances shaping …

Regional Forecasting Of Southern Pine Beetle Outbreaks In The Southeastern Usa Using Spbom1 With Artificial Intelligence-Based Modeling, Ebere L. Anozie

All Dissertations

Southern pine beetle (SPB; Dendroctonus frontalis) outbreaks are among the most damaging biological disturbances affecting pine forests of the southeastern United States, capable of causing extensive tree mortality, economic losses, and reduced ecosystem resilience. This dissertation evaluated and advanced predictive approaches for SPB outbreak forecasting by integrating systematic review, geospatial modeling, comparative model evaluation, and artificial intelligence-based prediction. First, a systematic review of SPB predictive tools from 1978 to 2024 showed that modeling has evolved from statistical, climatic, and mechanistic approaches to remote sensing, GIS, machine learning, hybrid modeling, and decision-support systems, although many tools remain limited by scale …

Considerations And Challenges For Oak-Pine Woodland Restoration In The Southern Appalachians, Armin Weise

All Dissertations

Appalachian forests in the southeastern United States are composed of fire-adapted communities. These have historically been burned by native Americans and by lightning-ignited fires, causing widespread ignitions across the landscape for millennia that have shaped the forest and the species within it. Many of the more xeric oak-pine forest systems in the region were more akin to woodlands with open midstories, understocked canopies, and a diverse understory layer of herbaceous species and shrubs. With the decline of Native Americans due to disease and forced removal, fire across the landscape declined, a trend compounded by fire-suppression policies put forth by the …

Can Kinematics Specify Tool Use Affordances?, Tyler Duffrin

All Dissertations

Object properties such as length, shape, and heaviness, as well as affordance-based properties such as strike-with-ability and poke-with-ability, can be perceived via dynamic touch as functions of inertia tensor invariants. The primary question addressed here was whether people can perceive these same power and precision properties for purely virtual objects, which lack dynamic physical forces. The Kinematic Specification of Dynamics (KSD) principle asserts that missing dynamics are lawfully specified by kinematic (visual) motion patterns, such that kinematic information alone may support successful interactions with virtual objects. In three experiments, we investigated (1) whether virtual reality (VR) users could calibrate to …

Lizards In The Trees: Structural, Functional, And Behavioral Specializations To A High-Risk Environment, Victor D. Munteanu

All Dissertations

Animals must contend with unexpected changes in their habitat and environment to thrive. Arboreal habitats can consist of a wide variety of environmental features, and failure to adequately contend with these features can result in high risk of injury or death upon falling. Despite these strong selective pressures, many vertebrate lineages have successfully invaded arboreal habitats. Using lizard taxa as a model system, I investigated how morphology and behavior have evolved within this specific habitat transition. I pursued these investigations through complementary analyses including: 1) evaluating the effect of stance height and tail prehensility on perturbation recovery, 2) assessing behavior …

Effects Of Urbanization On Barrier Island Bobcats, Meghan P. Keating

All Dissertations

Urbanization is a leading driver of ecological change and presents unique challenges for carnivores by altering habitat availability, prey communities, and exposure to anthropogenic threats. Although many carnivore species persist in developed landscapes, the ecological and demographic consequences of urbanization often remain poorly understood, particularly over long timescales. Using one of the longest-running studies of a free-ranging carnivore population, I evaluated the effects of urbanization on the behavior, resource use, exposure risk, and population dynamics of bobcats (Lynx rufus) inhabiting a residentially developed barrier island in coastal South Carolina, USA. I first examined temporal and spatial responses to …

Towards Improved Stress Resilience, Optimal Growth And Enhanced Biosafety In Transgenic Plants, Xiaotong Chen

All Dissertations

This dissertation investigates biotechnology strategies to improve plant stress resilience, growth, and biosafety in transgenic perennial grasses using creeping bentgrass as a model system. Functional analyses of non-coding RNAs such as miR164 and miR169 showed that regulatory non-coding RNAs influence plant architecture and abiotic stress responses through broad developmental and transcriptional networks, supporting them as valuable engineering targets for complex trait improvement. The dissertation also developed a dual recombinase platform for transgene containment and removal, linking trait engineering with biosafety control. Additionally, the recombinases themselves were examined for their potential impact on heterologous host and were found to reshape plant …

The Past, Present, And Future Of Climate Adaptation In A Widespread Lizard Species, Matthew R. Mcternan

All Dissertations

Climate, as a selective force, shapes patterns of biodiversity globally. However, how species adapt to climate remains a central question of biology. The need to understand climate adaptation is paramount, as global climate change threatens a large portion of global diversity. Climate can impose selection on life by either controlling rates of energy intake and expenditure through effects on body temperature and activity, or by exposing organisms to conditions beyond their physiological limits. Studies of climate adaptation have identified a wide-range of putatively adaptive phenotypic patterns, but genomic evidence is increasingly being used to investigate these patterns and better understand …

Prenatal Acoustic Programming Of The Developing Hypothalamus: A Multi-Omic Analysis Of Heat Call Exposure In Zebra Finch Embryos, Prakrit Subba

All Dissertations

Climate change is intensifying thermal stress on wildlife globally, yet the developmental mechanisms by which embryos use prenatal cues to adjust to predicted environments remain unclear. In Australian zebra finches (Taeniopygia guttata), incubating parents produce distinctive heat call vocalizations at high ambient temperatures, and embryos exposed to these calls during late incubation develop altered growth trajectories, thermoregulatory capacity, and reproductive outcomes, suggesting a form of anticipatory developmental programming triggered by sound alone. To investigate the molecular basis of this response, I initially hypothesized that prenatal heat call exposure would act primarily through hypothalamic neuroendocrine reprogramming, given the central …

Why Technical Readiness Is Not Enough: Institutional Barriers To Full Harvest Strategy Adoption In The International Pacific Halibut Commission, Evelyn Roozee, Owen Temby, Gordon M. Hickey

School of Earth, Environmental, & Marine Sciences Faculty Publications

Harvest strategies are increasingly promoted as a mechanism to reduce political discretion and align fisheries management with pre-agreed scientific objectives. While substantial progress has been made in tuna regional fisheries management organizations (RFMOs), non-tuna RFMOs have lagged behind. Existing research has focused primarily on technical modeling challenges, with comparatively limited attention to the governance dynamics shaping adoption. Using the International Pacific Halibut Commission (IPHC) as an instrumental case study, we examine the progress and delays in the development of a harvest strategy policy (HSP) through semi-structured interviews and participant observation. We find that the IPHC successfully addressed commonly cited barriers, …

Effect Of Food Resource, Preservation Method, And Preservation Duration On Larval Size Of Forensically Important Fly Species (Order: Diptera), John Zukowski

Student Theses

Forensic entomology is a vital discipline that can aid in the proceedings of criminal cases. Larval age and development are important aspects to consider when utilizing blow flies (Family: Calliphoridae) for estimates pertaining to the initial time of colonization (TOC), which contributes to postmortem interval (PMI) estimations. Thus, it is important to understand the factors that influence larval size and development, since larval size is commonly used as a proxy for age. Larvae of three species of flies, Lucilia sericata (Meigen), Calliphora vicina (Robineau-Desvoidy), and Phormia regina (Meigen), were reared on five different food resources. Specimens of L. sericata and …

Quaking Aspen On Cedar Mountain, Utah: Status And Update, Jaycee Cappaert, Larissa L. Yocom, Paul C. Rogers, Darren J. Mcavoy, R. Justin Derose

Wildland Resources Student Research

Quaking aspen forests are important communities in the western United States where they provide preferential food and habitat for animals, limit wildfires from spreading, and have favorable aesthetics, among other things. Their putative decline is an issue for ecology and management. We remeasured the aspen population on Cedar Mountain, Utah, to assess changes to its condition since it was originally measured in 2008 and laid the groundwork for continued aspen monitoring on Cedar Mountain. Our objectives were to compare current metrics of stand structure and composition, mortality, crown dieback, bole damage, regeneration, and recruitment, to those of the original inventory. …

Agent-Based Modeling Of Cellular Dynamics In Adoptive Cell Therapies, Yujia Wang

Dissertations and Theses (Open Access)

Adoptive cell therapies (ACT) have shown promising progress in combating cancer, but clinical responses remain heterogeneous. Key determinants, including the functional states of infused cells, tumor–immune interactions, and dosing strategies, are difficult to resolve experimentally in the dynamic and heterogeneous tumor microenvironment, limiting optimization of ACT products and treatment regimens. To address the gap, we developed ABMACT (Agent-Based Model for Adoptive Cell Therapies), a computational framework that reconstruct key cellular functions, interactions, and molecular signatures to recapitulate cell population dynamics associated with differential treatment responses. ABMACT encodes autonomous “virtual cells” using literature-informed rules calibrated with experimental data, enabling simulation of …

Transcriptional Regulation In The Uterine Luminal Epithelium, Evelyn A. Carrion

Dissertations and Theses (Open Access)

Transcriptional Regulation in the Uterine Luminal Epithelium

Evelyn A. Carrion

Advisor: Richard R. Behringer, PhD

Abstract

The uterus is an organ comprised of multiple tissues that are essential for women’s health and reproduction. The uterus is composed of multiple tissue layers, including the perimetrium, myometrium, and the endometrium. The endometrium is the inner lining of the uterus, and contains the luminal epithelium, glandular epithelium, and stroma. The luminal epithelium is a simple columnar layer of cells that is necessary for embryo implantation. The uterus is derived in part from the embryonic precursor tissue called the Müllerian duct. There are no …

Defining The Role Of Spxa1 And Spxa2 In Group A Streptococcus (Gas), Gretchen Anne Morrison

Dissertations and Theses (Open Access)

Group A Streptococcus (GAS) is a human-restricted pathogen whose global incidence has surged in the post-COVID era. The ability of GAS to shift from a colonizing to invasive phenotype depends on coordinated virulence gene regulation in response to host-imposed stressors. The paralogous global transcriptional regulators, SpxA1 and SpxA2, have emerged as central mediators of these adaptive responses; however, the mechanisms by which these regulators influence both global gene regulation in direct response to external stresses and the host response as a result of regulatory changes remain incompletely understood. Using an integrated multi-omic approach, we define the distinct yet interconnected regulatory …

Regulation Of Müllerian Duct Mesenchyme Transcription During Mammalian Sex Differentiation, Haowen Li, Richard R Behringer, Rachel D Mullen

Dissertations and Theses (Open Access)

Sp7/Osterix (Osx) encodes a zinc-finger transcription factor of the Specificity-protein family discovered by Nakashima et al. at the MD Anderson Cancer Center. While primarily recognized for its role in osteogenesis, Osx has also been implicated in mammalian reproductive development, particularly in male sex differentiation, where Müllerian Duct (MD) regression occurs, mediated by anti-Müllerian hormone (AMH) signaling. AMH-induced regression signals are transduced by the mesenchymal tissue surrounding the ductal structure, known as the Müllerian Duct mesenchyme (MDM). It was discovered that AMH signaling is necessary and sufficient for driving Osx expression in MDM. A previous transgenic mouse reporter …