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Breaking Virulent: The Coincidental Evolution Of Virulence Factors In Bacteria., Rhiannon Emmanuelle Cecil

Electronic Theses and Dissertations

Understanding how innocuous organisms can evolve to be pathogenic to humans is of increasing global concern. Further, understanding how existing pathogens may evolved to be more virulent is also vital to our ability to provide healthcare to people afflicted with diseases that promote chronic bacterial infections, such as cystic fibrosis. With the rise of antibiotic resistance in both bacteria and fungi it is paramount that new therapeutics are identified. Understanding what mutations occur that result in increased virulence in microbes can potentially provide new targets for antimicrobial drugs to combat antibiotic resistance. The Coincidental Evolution Hypothesis is a fundamental hypothesis …

Habitat Associations Of Plains Spotted Skunk (Spilogale Interrupta) Across The Plains Ecoregion. And The Landcover Occupancy Models Of The Gray Fox (Urocyon Cinereoargenteus) In The Southeastern Plains Region In Arkansas, Michael Shaw

Graduate Theses and Dissertations

Much of the landscape of the United States has been altered by humans, leading to the eradication of most populations of large mammalian predators. Consequently, many species of mammalian mesopredators (medium-sized mammalian predators) have come to dominate the landscape. Species such as the gray fox (Urocyon cinereoargenteus) may appear to be on the rise and doing well due to their widespread range, but at a local scale may need monitoring and less is known in areas of its range. Others such as the plains spotted skunk have a wide range across the plains but are on the decline even with …

Human-Bat Interactions In A Disease Emergence Hotspot: Implications For Human Health And Bat Conservation, Reilly Tempest Jackson

Graduate Theses and Dissertations

Bats are an ecologically important taxon that can host zoonotic pathogens. Globally, many bat species are synanthropic and live closely with humans, often roosting in man-made structures. The spatial overlap between humans and bats creates opportunities for human-bat contact, which can lead to human exposure to bat-borne pathogens and conflicts that cause bat mortality. Despite this risk, little is known about the drivers and characteristics of these human-bat interactions in buildings and work is needed to understand this aspect of the wildlife-urban interface. In Chapter I, I present a literature review that identifies the geographic and taxonomic trends in reported …

Activity Patterns Of Whiptail Lizards (Aspidoscelis) Found In The Northern Chihuahuan Desert, Guillermo Alvarez

Open Access Theses & Dissertations

Traditional lizard pitfall traps were modified to allow organisms to escape, while collecting valuable ecological data. Modified camera traps were capable of detecting the same species as traditional traps in a semi-arid environment, without posing the associated mortality risks. Pitfall-camera traps were used to sample the activity of the Side-blotched Lizard (Uta stansburiana) and the Southwestern Fence Lizard (Sceloporus cowlesi) in an urban wetland during four continuous years. Evaluations on activity pattern and the activity overlap between the two species revealed extensive overlap, with minor but significant seasonal shifts mediating coexistence. Traps were also effective at detecting other reptiles, invertebrates, …

Evaluation Of Evapotranspiration Estimates Using An Existing Hybrid Machine Learning Model In A Natural And A Managed Dryland Site, Katya Esquivel Herrera

Open Access Theses & Dissertations

Evapotranspiration (ET) is a critical component of the hydrologic cycle, encompassing both evaporative water loss from surfaces and transpiration through plant stomata. The environmental factors influencing ET include water and energy availability, atmospheric capacity for water uptake, and various meteorological variables. ET serves as a unique climate variable linking water, energy, and carbon cycles. In agroecosystems, accurate ET quantification is vital for optimizing water use efficiency, irrigation management, and crop yield. Traditional methods for ET estimation involve direct measurements and indirect models, with both presenting limitations.

Recent years have witnessed the integration of remote sensing and machine learning (ML) algorithms …

Evolution Of Forest Bitis (Macrocerastes) In Africa: Phylogeography, Population Genetics, And Potential As A Model For Batesian Mimicry, Eugene Richard Vaughan

Open Access Theses & Dissertations

The major biogeographical patterns characterizing the diversification of widely distributed species in the African rainforest remain poorly understood because of the low number of well-sampled studies that are focused on this region. I examine the phylogeography and population genetics of two broadly sympatric sister lineages of large African forest vipers (genus Bitis, subgenus Macrocerastes), the rhinoceros viper (B. nasicornis) and the Gaboon vipers (B. gabonica and B. rhinoceros). Despite their close relationship, these two lineages have notably different patterns of divergence in time and space. A time-calibrated phylogeny with sequence data from five genes, and population structure and PCA analyses …

Reducing Inputs And Adding Value To Turfgrass Systems Through Clover Inclusion And Plant Growth-Promoting Rhizobacteria Applications, Paige E. Boyle

All Graduate Theses and Dissertations, Fall 2023 to Present

Recently, the US has seen an expansion in the amount of turfgrass land cover (lawns, parks, roadsides, sports fields, and golf courses), as well as an interest in reducing fertilizer, water, and pesticide use in these grass systems. To help maintain quality and function while reducing resource inputs, two promising approaches have emerged: planting clover into lawns and applying plant growth-promoting rhizobacteria.

White clover and grass mixtures have been studied for their ability to cut down on fertilizer usage and provide a uniform, dark green lawn, but other clover types have not been as widely studied and may provide similar …

Edaphic And Climatic Regulation Of Microbial Carbon-Use Efficiency In Managed Semi-Arid Systems, Kirsten R. Butcher

All Graduate Theses and Dissertations, Fall 2023 to Present

In agricultural systems, an increasingly prevalent goal is to promote carbon sequestration into stable, mineral-associated soil organic matter, as increases in soil organic matter have been linked to increases in soil water-holding capacity and increases in nutrient availability. Because microbially-produced compounds are the foundation of soil organic matter, understanding interactions between management strategies and abiotic controls on microbial activity can prove invaluable for producers and ranchers interested in building soil organic matter and safeguarding production systems under a changing climate. The ability of microorganisms to contribute to growing soil organic matter stocks is dictated by their carbon-use efficiency, which is …

Germination Trends Of American Chaffseed, Schwalbea Americana L., And Factors Affecting First-Year Seedling Development, Trenton Miller

All Theses

Following centuries of exploitation and fire suppression, longleaf pine systems are now the focus of many conservation efforts. Efforts to restore populations of Schwalbea americana L. in longleaf pine savannas have been met with frustratingly low recruitment. While past studies have briefly quantified germination rates for Schwalbea, there have not been any studies yet that truly investigate this plant’s germination requirements. Additionally, there has been little research into characterizing the parasitic relationship between Schwalbea and its various host species. We conducted a germination study in a growth chamber that investigated Schwalbea’s germination rate and time to germinates as …

Accelerated Evolution Of Sars-Cov-2 In Free-Ranging White-Tailed Deer, Dillon S. Mcbride, Sofya K. Garushyants, John Franks, Andrew F. Magee, Steven H. Overend, Devra Huey, Amanda M. Williams, Seth A. Faith, Ahmed Kandeil, Sanja Trifkovic, Lance Miller, Trushar Jeevan, Anami Patel, Jacqueline M. Nolting, Michael J. Tonkovich, J. Tyler Genders, Andrew J. Montoney, Kevin Kasnyik, Timothy J. Linder, Sarah N. Bevins, Julianna B. Lenoch, Jeffrey C. Chandler, Thomas J. Deliberto, Eugene V. Koonin, Marc A. Suchard, Philippe Lemey, Richard J. Webby, Martha I. Nelson, Andrew S. Bowman

United States Department of Agriculture Wildlife Services: Staff Publications

The zoonotic origin of the COVID-19 pandemic virus highlights the need to fill the vast gaps in our knowledge of SARS-CoV-2 ecology and evolution in non-human hosts. Here, we detected that SARS-CoV-2 was introduced from humans into white-tailed deer more than 30 times in Ohio, USA during November 2021-March 2022. Subsequently, deer-to-deer transmission persisted for 2–8 months, disseminating across hundreds of kilometers. Newly developed Bayesian phylogenetic methods quantified how SARS-CoV-2 evolution is not only three-times faster in white-tailed deer compared to the rate observed in humans but also driven by different mutational biases and selection pressures. The long-term effect of …

Analysis Of Mitochondrial Dna Sequence Data Demonstrates That Monophyly Of Myotis Occultus Is Complicated By Greater Sampling Of Myotis Lucifugus, Jeffrey M. Lorch, Daniel R. Taylor, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Abstract

The validity of Myotis occultus as a species unique from Myotis lucifugus has been a source of debate. Most recently, many authorities treat M. occultus as a distinct species, at least in part because a previous study showed that M. occultus and M. l. carissima (the subspecies that occurs in closest geographic proximity to M. occultus) form separate monophyletic clades based on sequences of two mitochondrial genes (cytochrome-b [cytb] and cytochrome oxidase subunit II [COII]). We re-evaluated the phylogenetic relationship between M. occultus and M. lucifugus based on mitochondrial sequences …

Effects Of A Protection Zone In A Reaction-Diffusion Model With Strong Allee Effect., Isaac Johnson

Electronic Theses and Dissertations

A protection zone model represents a patchy environment with positive growth over the protection zone and strong Allee effect growth outside the protection zone. Generally, these models are considered through the corresponding eigenvalue problem, but that has certain limitations. In this thesis, a general protection zone model is considered. This model makes no assumption on the direction of the traveling wave solution over the Strong Allee effect patch. We use phase portrait analysis of this protection zone model to draw conclusions about the existence of equilibrium solutions. We establish the existence of three types of equilibrium solutions and the necessary …

Impacts Of Environmental Stressors On Native South Dakota Amphibian Physiology And Survival, Danielle Jean Galvin

Dissertations and Theses

Amphibian populations around the world are declining, with some of the most likely drivers behind these declines including emerging infectious diseases and environmental contaminants. To address major gaps in the current literature, I sought to evaluate the effect of two major environmental stressors on various aspects of amphibian physiology: emerging infectious diseases and environmental contaminants. Emerging infectious diseases of amphibians include fungal, viral, and parasitic pathogens which have expanded in host range, either geographically or in competent host species. Environmental contaminants include chemicals which may be naturally occurring in the environment, or which may be introduced to the environment, often …

Effects Of Landcover On Mesocarnivore Density And Detection Rate Along An Urban To Rural Gradient, Leah E. Mctigue, Brett Degregorio

Biological Sciences Faculty Publications and Presentations

Human development has major implications for wildlife populations. Urban-exploiter species can benefit from human subsidized resources, whereas urban-avoider species can vanish from wildlife communities in highly developed areas. Therefore, understanding how the density of different species varies in response to landcover changes associated with human development can provide important insight into how wildlife communities are likely to change and provide a starting point for predicting the consequences of those changes. Here, we estimated the population density of five common mesocarnivore species (coyote (Canis latrans), bobcat (Lynx rufus), red fox (Vulpes vulpes), raccoon (Procyon …

Interactions Between Fitness Components Across The Life Cycle Constrain Competitor Coexistence, Miguel Gómez-Llano, Wade A. Boys, Taylor Ping, Simon P. Tye, Adam M. Siepielski

Biological Sciences Faculty Publications and Presentations

1. Numerous mechanisms can promote competitor coexistence. Yet, these mechanisms are often considered in isolation from one another. Consequently, whether multiple mechanisms shaping coexistence combine to promote or constrain species coexistence remains an open question.
2. Here, we aim to understand how multiple mechanisms interact within and between life stages to determine frequency-dependent population growth, which has a key role stabilizing local competitor coexistence.
3. We conducted field experiments in three lakes manipulating relative frequencies of two Enallagma damselfly species to evaluate demographic contributions of three mechanisms affecting different fitness components across the life cycle: the effect of resource competition on individual growth …

Effects Of Seasonal Environment On Abundance, Behavior, Visual Signaling, And Perception In Prairie Butterflies, Grace Elizabeth Hirzel

Graduate Theses and Dissertations

Phenotypic plasticity is a widespread mechanism that allows animals to respond quickly to seasonal changes in their environment. However, the depth and complexity of these plastic responses is still being discovered. One aspect of seasonal physiology that is relatively unstudied is changes to sensory physiology and how it may explain changes in behavior. To determine how changes in seasonal conditions affect behavior, coloration, and vision, I examined populations of wild butterflies in Northwest Arkansas. Focusing on a single species, the common buckeye Junonia coenia, I found that seasonal coloration covaries with thermoregulating behavior and is accompanied by changes in visual …

Unlocking The Mysteries Of Opportunism: Neuroendocrine Insights From An Aseasonal Breeder (Taeniopygia Guttata), Jessica A. Moodie

Graduate Theses and Dissertations (2019 - present)

The regulation of reproductive physiology in animals is mediated by the Hypothalamus-Pituitary-Gonad (HPG) axis. In seasonal breeders, a conserved reciprocal switching of deiodinase enzymes alters thyroid hormone signaling, which controls HPG activity. This study tested the hypothesis that neural regulation of the HPG axis as described in seasonal systems is conserved and repurposed to respond to other cues in aseasonal species. Using water deprivation and nest restriction in the opportunistic Zebra Finch, we were able to create a breeding group and non-breeding group, confirmed by egg laying and changes in ovarian anatomy. Breeding females had clear follicular hierarchy, increased ovary …

Interactions Between Sediment Mechanical Structure And Infaunal Community Structure Following Physical Disturbance, William Cyrus Roger Clemo

Graduate Theses and Dissertations (2019 - present)

Shallow, river-influenced coastal sediments are important for global carbon storage and nutrient cycling and provide a habitat for diverse communities of invertebrates (infauna). Elevated bed shear stress from extreme storms can resuspend, transport, and deposit sediments, disrupting the cohesive structure of muds, and sorting and depositing sand eroded from beaches. These physical disruptions can also resuspend or smother infauna, decreasing abundances and changing community structure. Infaunal activities such as burrowing, tube construction, and feeding can impact sediment structure and stability. However, little is known about how physical disturbance impacts short and long-term sediment habitat suitability and whether disturbance-tolerant infauna influence …

Effect Of Plant Genotype On Plant-Microbe Interactions And Multi-Generation Ecosystem Selection Of Microbial Communities Associated With Plant Biomass In Arabidopsis Thaliana, Nachiket Shankar

Graduate Doctoral Dissertations

The microbiome's role in shaping host phenotypes is a critical area of investigation, with implications for ecology, evolution, and host health. Dynamic plant-microbe interactions are influenced by factors like soil type, environment, and genotype. Understanding their impact on microbial communities is key for tailored plant benefits. An artificial ecosystem selection experiment was done for eight generations with Arabidopsis thaliana Ler and Cvi. This revealed distinct microbial communities shaped by genotypes and biomass treatments. Initially, environment dominated, but over time, genotype and biomass gained influence, explaining ~40% of the variation. Moreover, genotype-specific rhizobacterial associations were observed, enhancing understanding of community dynamics …

Patterns In Winter Stonefly Distribution Along A River Continuum And Land-Use Gradient In Northwest Arkansas Streams, Zachary Tipton

Graduate Theses and Dissertations

Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need …

Polluting The Senses: The Impact Of Noise And Light Pollution On Fledgling Movement And Evolution Within The Avian Eye, Margaret C. Mackinlay

Master's Theses

There is more human-generated noise and light today than ever before, a trend tied to ongoing urbanization and with reverberating impacts on a wide range of organisms. While research on these impacts is mounting and particularly plentiful when it comes to birds, there is still much to explore within its effects on avian behavior, fitness, and evolution. In chapter 1, we investigated how fledgling movement is influenced by noise and light pollution. While adult birds have well-documented species-specific responses to these stimuli, fledglings are sorely understudied in this context. We experimentally manipulated light levels and took advantage of an existing …

Balsam Woolly Adelgid And Host Forest Characteristics: Impacts And Interactions In Recently Invaded Areas Of Northern Utah And Southeastern Idaho, Grayson B. Jordan

All Graduate Theses and Dissertations, Fall 2023 to Present

The balsam woolly adelgid (BWA), is an invasive forest insect native to central and southern Europe. In 2017, it was detected in Utah for the first time. While BWA had limited impact as a pest in its native European range, it has caused considerable damage to true fir populations in North America. In the Intermountain region, subalpine fir has been identified as the tree species most at risk of BWA infestation. Subalpine fir provides a variety of ecosystem services and is a critical component of the spruce-fir alpine forests of the area. With an expected increase in the severity and …

Specialized Recreation, Spatial Behavior, And Ecological Implications In The Nature Reserve Of Orange County, Ca, Jake Van Deursen

All Graduate Theses and Dissertations, Fall 2023 to Present

A widespread surge in park and protected area (PPA) visitation strikes managers with the imminent challenge of preserving ecological conditions and maintaining accessibility in the open spaces that are a fundamental component to the health and wellness needs of society. In the field of recreation resource management, recreation specialization, the selective channeling of interests and abilities into a specific recreational activity, has contributed to comprehensive understandings of recreation behavior, site preference, management perceptions and conservation support. Contributing to historical understandings of specialization can inform recreation planning on the diversity of uses occurring in urban-proximate PPAs. Survey data providing information on …

Metapopulation Genomics Of American Goshawks In The Intermountain West, Megan M. Sidran

All Graduate Theses and Dissertations, Fall 2023 to Present

Understanding a species dispersal ecology and population dynamics is essential to effectively manage and conserve a species. As advancing technology improves our knowledge of species movements, it is becoming clear that many species form metapopulations to some extent. A metapopulation is a network of interconnected subpopulations that exchange reproductive individuals with subpopulations occupying nearby patches. Metapopulations have been observed in a variety of species, ranging from plants to vertebrates, and can vary greatly in their dynamics (level of connectivity and gene flow) based on the species behavior and life history strategy.

Forming a metapopulation can add much resilience to the …

Developing Empirical Predictive Models To Support Conservation Planning For Threatened Frogs, Toads, And Turtles In South-Coastal California, Umarfarooq Adavudi Abdulwahab

All Graduate Theses and Dissertations, Fall 2023 to Present

Amphibians and reptiles (i.e., herptiles) are among the most threatened groups of species on Earth. The major threats to these species include the direct, indirect, and synergistic effects of habitat loss and fragmentation, invasive species, disease, overexploitation, and pollution. To protect and restore species, natural resource managers need effective, data-driven conservation plans that are grounded in sound knowledge of species distributions and habitat requirements. Species distribution models (SDMs) are popular tools used to assess species-habitat relationships. However, SDMs are sensitive to the choice and quality of input data, both of which can affect model accuracy and precision and lead to …

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …

Dusky Grouse Population Ecology And Thermal Landscape Ecology In The Great Basin Ecosystem, Stephanie M. Landry

All Graduate Theses and Dissertations, Fall 2023 to Present

Dusky Grouse are a mountainous forest grouse found throughout the western, inland mountain ranges of the United States and Canada. While a few studies have looked at Dusky Grouse in the Rocky Mountain Ecosystem of their range, there have been no prior studies of the Dusky Grouse in the Great Basin Ecosystem aside from a brief survey by Zwickel and Bendell in 2004 in the Duck Creek Range of Nevada. With the available habitats differing in both species diversity and availability on the landscape between the two Ecosystems, I wanted to assess characteristics about the Dusky Grouse populations at the …

Restoration Strategies For Wetlands In The Arid West: Seeding And Planting Approaches For Lakeshore Ecosystems, Jes Braun

All Graduate Theses and Dissertations, Fall 2023 to Present

Wetlands are widely recognized for their valuable benefits such as providing habitat, improving water quality, and reducing the impacts of flooding. However, wetlands face threats from development, drought, and invasive species. This is particularly apparent in the arid west, where upstream water use and drought make water scarcer and contribute to dramatically changing water levels. Here, I investigated revegetation techniques for lakeshore wetlands, using Utah Lake as a case study. Although recent management efforts have minimized invasive Phragmites cover, the desired plant communities are not returning as quickly as needed, highlighting the need to research restoration techniques. Through my research, …

How Beavers (Castor Canadensis) Affect Habitat Availability For Two Native Oregon Turtles: Actinemys Marmorata And Chrysemys Picta Bellii, Rodé Krige

University Honors Theses

Oregon is home to two native freshwater turtle species: the northwestern pond turtle and the western painted turtle. Both turtles are Oregon conservation strategy species with a status rating of sensitive, indicating declining populations. Oregon's decline in these turtle's populations is thought to be predominantly due to loss and degradation of habitat that results from development and urbanization. Beavers' ability to dam streams and create ponds may be creating habitat usable by turtles, but the relationship is under-studied. This study assessed water temperature, basking habitat, and overall turtle habitat suitability at beaver-dammed and control ponds in Portland, Oregon. Average basking …

Assessment Of Green Spaces In Metro Nashville Public High Schools, Webster G. Andrews, Anna Lennon, Darlene Panvini

Science University Research Symposium (SURS)

Green spaces on and near school property have been correlated to student mental health and academic achievement. However, there is a gap in the literature investigating how quality and quantity of green space is related to socioeconomic status and school economic metrics in public high schools and the surrounding neighborhoods. Nashville public high schools located in higher socioeconomic areas and having greater financial resources were predicted to provide larger, higher quality green spaces. This study combined a quantitative analysis of neighborhood socioeconomic metrics, school socioeconomic metrics, and quantity of green space (assessed using iTree Canopy) with a qualitative field assessment …