Life Sciences Commons^™

Soil Response To Fire Frequency In The Northern Columbia Basin Sagebrush Steppe, Leslie C. Nichols

Boise State University Theses and Dissertations

Fire is one of the most significant disturbances in an ecosystem, as it is capable of altering the physical, chemical, and biological properties of soil, and the fire frequency in semi-arid ecosystems is increasing. These changes can potentially alter plant-soil feedbacks that may affect post-fire recovery of the native plant and soil communities and lead to an ecosystem state change. However, there is much uncertainty about the magnitude of change as soils are exposed to more fires, because soil recovery and changes in fire severity following a first fire mediate the impact of successive fires on soil properties. To improve …

Observed Defects Of Swiss Cheese Based On The Microbiome Contribution To The Production Of Organic Acids, Vannessa D. Campfield

Boise State University Theses and Dissertations

The United States Department of Agriculture downgrades on the order of 17% of all Swiss cheese produced in the United States due to defects. Many of these defects are related to improper eye formation, number, distribution, or size; leading to an industry loss of over $69 million per annum. The microbiome in Swiss-type cheeses plays a significant role in eye development due to production of organic acids and gaseous emissions contingent on bacterial abundance and phenotype. The relationship between bacteria and the organic acids they produce leading to Swiss cheese defects can be correlated using Next-generation sequencing and high-performance liquid …

Regulation Of In Vitro And In Vivo Hepatic Stellate Cell Activation By The Ayrl Hydrocarbon Receptor, Shivakumar Rayavara Veerabhadraiah

Boise State University Theses and Dissertations

Liver fibrosis is a pathological condition characterized by the excessive deposition of extracellular matrix material by activated hepatic stellate cells (HSCs). We recently reported that activation of the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases HSC activation in vitro and in mouse models of experimental liver fibrosis. The goal of this project was to determine the mechanism by which AhR activation impacts HSC activation and the subsequent development of liver fibrosis. It is possible that HSCs are direct cellular targets for TCDD. Alternatively, TCDD could increase HSC activation indirectly by exacerbating hepatocyte damage …

Identification And Characterization Of Candidate Staphylococcus Aureus Antigens For Inclusion In A Multivalent Bovine Mastitis Vaccine, Danielle Scarbrough

Boise State University Theses and Dissertations

Bovine mastitis, inflammation typically caused by bacterial infection, is the most prevalent disease affecting the global dairy industry. Staphylococcus aureus remains one of the most important pathogens implicated in the disease and can persist within herds at subclinical levels. A preventative S. aureus bovine mastitis vaccine would substantially lessen costs associated with treatment and restore revenue lost due to decreased milk production. One such experimental vaccine is the IsdA-CTA₂/B + ClfA-CTA₂/B vaccine, containing the S. aureus antigens IsdA and ClfA , each fused to the nontoxic A₂/B subunits of cholera toxin, which serves as …

Phenotypic Responses Of Sagebrush To The Southwestern North America Megadrought: A Genotype-By-Environment (Gxe) Approach, Kara A. Navock

Boise State University Theses and Dissertations

The Southwestern North America megadrought is an extreme climate event. Artemisia tridentata (big sagebrush) is the dominant, keystone species of sagebrush-steppe ecosystems in arid and semi-arid habitats of western North America. I conducted a genotype-by-environment (GxE) experiment on two putative genotypes (drought-tolerant, G1 and drought-sensitive, G2) and two cytotypes, diploid (2x) and tetraploid (4x), to determine the phenotypic responses of big sagebrush seedlings to drought. For three chlorophyll fluorescence parameters, my results indicate a complex set of factors influence sagebrush responses to drought, including canalization, adaptive phenotypic plasticity, cryptic genetic diversity, and GxE interactions. Variation in leaf temperature profiles of …

Analytic Solutions For Diffusion On Path Graphs And Its Application To The Modeling Of The Evolution Of Electrically Indiscernible Conformational States Of Lysenin, K. Summer Ware

Boise State University Theses and Dissertations

Memory is traditionally thought of as a biological function of the brain. In recent years, however, researchers have found that some stimuli-responsive molecules exhibit memory-like behavior manifested as history-dependent hysteresis in response to external excitations. One example is lysenin, a pore-forming toxin found naturally in the coelomic fluid of the common earthworm Eisenia fetida. When reconstituted into a bilayer lipid membrane, this unassuming toxin undergoes conformational changes in response to applied voltages. However, lysenin is able to "remember" past history by adjusting its conformational state based not only on the amplitude of the stimulus but also on its previous …

In Vitro Regeneration, Rooting, And Cloning Of Artemisia Tridentata, Rachael Barron

Boise State University Theses and Dissertations

Artemisia tridentata (big sagebrush) is an ecologically important shrub found in western North America. In vitro techniques can be applied to big sagebrush for the purpose of studying gene function, genotypic and phenotypic plasticity studies, cloning, genotypic preservation, and restoration. I performed experiments to develop an indirect organogenesis protocol to regenerate whole Wyoming big sagebrush plants from leaf explants. Callus formation frequency was 88% (±4.0%) in leaf explants cultured on medium containing 0.5 mg/l BAP and 1.0 mg/l NAA. Shoot formation frequency was variable between replicates and was the highest when callus tissue was cultured on medium containing 1.5 mg/l …

Movements Of White-Headed And White-Backed Vultures, Teague K. Scott

Boise State University Theses and Dissertations

Vultures are the only obligate vertebrate scavengers, and as such provide crucial services as keystone species and support the health and function of ecosystems in which they live. African vultures are a diverse group, with nine species found throughout Sub-Saharan Africa, many with overlapping distributions. Unfortunately, African vultures are faced with numerous threats throughout their range that have led to significant population declines, some greater than 90%, in only three generations. Four of these species are currently listed as critically endangered, and three as endangered.

Despite the significant perils faced by African vultures, there are still significant knowledge gaps and, …

Effects Of Prolonged Load Carriage Of Knee Adduction Biomechanics, Micah Daniel Drew

Boise State University Theses and Dissertations

Introduction: Incidence of knee osteoarthritis (OA) in service members is twice that of the general population. Yet, it is currently unknown how body borne load and duration of walking with body borne load impact knee adduction, biomechanics linked to progression and severity of OA. Purpose: This study sought to examine magnitude and variability of knee adduction joint angle and moment throughout a prolonged walking task with body borne load. Methods: Eighteen participants had knee biomechanics quantified every five minutes while they walked at 1.3 m/s during a 60-minute over-ground walking task with three body-borne loads (unloaded, 15 kg and 30 …

Plant Diversity And Nitrogen Addition On Belowground Biodiversity And Soil Organic Carbon Storage In Biofuel Cropping Systems, Jennifer Butt

Boise State University Theses and Dissertations

Bioenergy production may reduce the emission of CO₂ which contributes to climate change, particularly when management strategies are adopted that promote soil carbon (C) sequestration in bioenergy cropping systems. Planting perennial native grasses, such as switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman) may be used as a strategy to enhance soil C accumulation owing to their extensive root systems. Fertilizer use may further promote soil C sequestration, because of its positive impacts on plant production and soil C input. However,, the influence of fertilizer addition on soil C accumulation is variable across bioenergy cropping …

Prevalence Of Anticoagulant Rodenticides In Ferruginous Hawk Nestlings And Evaluation Of A Novel Method To Rapidly Assess Exposure, Ariana Joyce Dickson

Boise State University Theses and Dissertations

Anticoagulant rodenticides (ARs) are compounds commonly used to control rodent pests by inhibiting an enzyme critical for synthesis of clotting factors in their blood. Secondary and tertiary poisoning of non-target species frequently occur, especially of predators that consume rodents, including many species of raptors. Although raptor exposure to ARs has been documented on at least three continents, patterns, pathways and the sub-lethal effects of exposure are not well studied. This has created a substantial need to monitor the effects of ARs in free-living populations. I evaluated the prevalence of secondary, non-target exposure to anticoagulant rodenticides experienced by a predatory raptor, …

Molecular Approaches For Analyzing Organismal And Environmental Interactions, Stephanie Fern Hudon

Boise State University Theses and Dissertations

Our planet is undergoing rapid change due to the expanding human population and climate change, which leads to extreme weather events and habitat loss. It is more important than ever to develop methods which can monitor the impact we are having on the biodiversity of our planet. To influence policy changes in wildlife and resource management practices we need to provide measurable evidence of how we are affecting animal health and fitness and the ecosystems needed for their survival. We also need to pool our resources and work in interdisciplinary teams to find common threads which can help preserve biodiversity …

Patterns And Drivers In Counts Of Migratory Raptors At Hawk Mountain Sanctuary, Usa, Patricia Kaye Tahura Dumandan

Boise State University Theses and Dissertations

Understanding the mechanisms driving biodiversity patterns amidst an era of global environmental change is the core of modern ecological research. The magnitude of biodiversity losses associated with anthropogenic activities has prompted resource managers and ecologists alike to identify strategies to address conservation issues. Broadly, two types of approaches are employed to answer ecological research questions: 1) single-species and 2) ecosystem-based approach. Single-species approaches are often useful to elucidate mechanisms driving population trajectories of individual species. On the other hand, ecosystem-based approaches can help in identifying general patterns that may be useful for multi-species management.

Here, I used both approaches in …

A Symbiosis Between A Dark Septate Fungus, An Arbuscular Mycorrhiza, And Two Plants Native To The Sagebrush Steppe, Craig Lane Carpenter

Boise State University Theses and Dissertations

Plant roots form symbioses with various fungi, including arbuscular mycorrhizae (AMFs) and dark septate endophytes (DSEs). The symbiosis between plants and AMFs has been extensively studied and is generally considered to be mutualistic. Much less is known about the symbiosis between plants and DSE. In sagebrush habitats, DSEs are common, but their effects on the vegetation are unclear. As a first step to study these effects, I isolated and cultured a DSE from the roots of the shrub Artemisia tridentata. Based on partial sequences of five genes and phylogenetic analyses, the isolated fungus was a non-described species within the …

A Metanalysis Of Sequences Of Vascular Plants In The World’S Biodiversity Hotspots With A Special Section On Madagascar, John Michael Adrian Wojahn

Boise State University Theses and Dissertations

Humans have become a major factor in reshaping the Earth’s biosphere. One of the major effects of human changes to the environment is an increase in the rate of species extinction as compared to background rates. Biodiversity hotspots are areas whose species assemblages are very rich (50% of the world’s plants and 42% of land vertebrates) yet very threatened with extinction ( > 70% habitat destruction), and which ought to be foci for conservation efforts. The intense peril in which the flora of these endangered regions are requires an equally intense response from the scientific community. This study investigated the benefits …

Spectral Fingerprints Predict Functional Phenotypes Of A Native Shrub, Brecken Cherice Robb

Boise State University Theses and Dissertations

Landscapes are rapidly changing. To understand these changes and how they may influence coexisting herbivores, it is critical that we improve the ways in which we monitor changes in plant species, populations, and functional phenotypic traits over space and time. Near infrared spectroscopy (NIRS) is proving to be a valuable tool when it comes to this goal. NIRS is noninvasive and can provide high-resolution temporal information, including structural and chemical characteristics, on objects that are otherwise expansive, inaccessible, or imperceptible. We used the threatened sagebrush-steppe ecosystem, which spans over 43 million hectares of the Western United States, as a case …

Phenological Mismatch Is Correlated With Fitness Outcomes And Adaptive Behavior In A Generalist Avian Predator Distributed Across North America, Kathleen R. Callery

Boise State University Theses and Dissertations

Climate-driven advances in the start of spring may result in a phenological mismatch between peak-prey abundance and the breeding season of secondary consumers. Phenological mismatch has been well-studied in insectivorous birds for which reproductive productivity is strongly linked to caterpillar abundance. The effects of mismatch on the productivity of dietary generalists, that forage on several types of prey, are less well-understood. Further, few studies have addressed questions about the effects of mismatch on survival, an important component of fitness that can be affected by breeding in sub-optimal conditions. We examined the relationship between phenological mismatch and fitness for a widespread …

Learning From Chemical Coping Behaviors Of Wildlife To Discover New Approaches For Pest Management, Britt Pendleton

Boise State University Theses and Dissertations

Pests, such as parasites and pathogens, persist throughout time and space as threats to public health and food security. The need for novel and sustainable approaches to managing these threats are in high demand. The current approach of discovering and developing chemical treatments to manage pests is tedious, not efficient, and often outpaced by traits of resistance in pests. Here, we propose a new approach to discovering new chemical pest management solutions by observing chemical coping behaviors in wildlife. We define a chemical coping behavior as the exploitation of naturally occurring chemicals within a host’s environment to manage pests. Specifically, …

Dimerization Of The Notch Intracellular Domain Results In Distinct Signaling Activity, Jacob Jeffery Crow

Boise State University Theses and Dissertations

The Notch signaling pathway is a core component of multicellularity; enabling cells to directly communicate with both their neighbors and the surrounding microenvironment. These signals are translated directly through the Notch proteins, where a fragment of Notch transitions into the nucleus to act as a co-transcription factor, setting into motion a host of physiological responses. Commonly involved in pathways that define a cell’s identity and fate decisions, what appears to be a simplistic pathway instead exists in a state of high-tunability and strict control. Missteps in this pathway are generally embryonically lethal or lead to a suite of congenital disorders …

Sagittal And Frontal Plane Knee Angular Jerk Effects During Prolonged Load Carriage, Samantha M. Krammer

Boise State University Theses and Dissertations

Introduction: Musculoskeletal injuries are a costly military problem that routinely occur during training. Quantifying smoothness of knee motion, or angular knee jerk, may be an effective measure to monitor injury risk during training, but to date, the effects of body borne load and prolonged locomotion on angular knee jerk are unknown. Purpose: This study sought to quantify angular knee jerk for frontal and sagittal plane motion during prolonged load carriage. Methods: Eighteen participants had peak and cost of angular jerk for frontal and sagittal plane knee motion quantified while they walked (1.3 m/s) 60-minutes with three body borne loads (0, …

Analyzing Change-Of-Direction And The Laterally Resisted Split Squat: Incorporating A Lateral Vector Into The Single Leg Squat, Derek Maddy

Boise State University Theses and Dissertations

Improving change of direction (COD) with the use of strength training has led to mixed results. To date, the modified single leg squat (MSLS) and the bilateral squat (BS) have been successfully used to improve COD, with equal improvement. COD is primarily performed at a 45-75° frontal plane angle; however, the MSLS and BS are performed at a 90° frontal plane angle. Based on the force vector theory, it is proposed that a more mechanically similar strength training exercise, the Laterally Resisted Split Squat (LRSS), be used. The purpose of this study is to compare COD with the LRSS, MSLS, …

Genetic Analysis Of Invasive Populations Of Ventenata Dubia (Poaceae): An Assessment Of Propagule Pressure And Pattern Of Range Expansion In The Western United States, Inna Pervukhina-Smith

Boise State University Theses and Dissertations

Molecular markers prove to be an invaluable tool in assessing the introduction dynamics, pattern of range expansion, and population genetics of an invasive species. Ventenata dubia (Leers) Coss. (Aveneae; ventenata) is a diploid, primarily self-pollinating, annual grass native to Eurasia and Northern Africa. The grass has a detailed herbarium collection history in the western United States since its discovery in eastern Washington in 1952. Genetic analysis of 51 invasive populations (1636 individuals) of V. dubia, coupled with historical records, suggests moderate propagule pressure from multiple introductions, followed by local or regional range expansion. Enzyme electrophoresis detected nine multilocus genotypes …

How Water Level And Irrigation Practices Affect Waterbird Community, Nesting, And Foraging Habitat Use On The Duck Valley Indian Reservation, Jamie L. Burke

Boise State University Theses and Dissertations

Loss of habitat continues to threaten all bird populations. Despite efforts for conservation of wetlands, waterbirds continue to face habitat threats especially in western North America where water resources are limited across the landscape. The White-faced Ibis (Plegadis chihi) is a colonial nesting waterbird of conservation concern that builds nests in emergent vegetation of freshwater wetlands throughout the western United States. An ibis breeding colony site located at the Blue Creek Wetland complex on Duck Valley Indian Reservation may face habitat threats in the future due to plans intended to increase irrigation water use efficiency. Plans include manipulation …