The Warm Springs Reservation is located in central Oregon. Livestock production consists of beef (commercial with an Angus, Horned Hereford base) and roping (Corriente and Longhorn) cattle and horses that forage most of the year on the open range within reservation boundaries. Forage consists of annual and perennial grasses and...
Sex differentiation in fish is a labile process that allows sex inversion in several species. The inherent capacity of fish germ cells to differentiate into oocytes or spermatocytes constitutes a key factor allowing for functional sex inversion. This thesis set out to determine the mechanism involved in steroid-induced sex differentiation...
Shallow landslides are a prevalent concern in mountainous regions that can result in severe societal, economic, and environmental impacts. The challenge is further compounded as the size and location of a potential slide is often unknown. This study presents a generalized approach for the evaluation of shallow landslide susceptibility using...
Increasing temperatures in western North America are expected to result in a decline in winter snowpacks, earlier snowmelt, and a shift in the timing of streamflows, with an increasing fraction of streamflows occurring earlier in the water year and drier conditions during the summer. However, few streamflow datasets have associated...
Glacial isostatic adjustment (GIA) alters the amplitude and timing of ‘glacioeustatic’ sea level maxima and minima around the globe. No study has examined the intrinsic distance that one can correlate marine stratigraphic records of glacial–interglacial sedimentation across continental shelves subject to varying amounts of GIA. Here, we seek to model...
Helical anchors are a type of deep foundation element that can be installed quickly in almost any location and can accept the immediate application of operational loads. The use of helical anchors has expanded in recent decades from its established application in the power transmission industry to more traditional civil...
This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at...
Chemoreception is one of the dominant sensory modalities for many species of salamanders (reviewed in Chapter 2). At least seven of the ten currently recognized salamander families are known to respond to some sort of chemical cue. These responses are as varied as delaying hatching, seeking refuge, or initiating aggressive...
Pseudomonas is a diverse genus of Gamma proteobacteria that are ubiquitous in the natural environment, including soil, water, plant surfaces, and animals. The Pseudomonas fluorescens group is a diverse collection of seven subgroups and more than 50 named species. This group is known for their production of a variety of...
Deep foundations are necessary for the construction of many structures, such as bridges and buildings, located in areas unsuitable for shallow foundations. Owing to the inherent variability of soil and the complex changes that occur in the soil adjacent to deep foundations as they are installed, the ability to accurately...
Sexual selection can influence the mating system of an organism through multiple mechanisms. These mechanisms result in variation in reproductive success among individuals, and include scramble competition, endurance rivalries, contests, mate choice and cryptic choice, and sperm competition. Understanding the mating system of a species requires the identification of which...
The number of endangered species is rapidly increasing while paucity of adequate information and resources delays establishment of conservation actions. The IUCN’s listing system is insufficient to determine conservation priorities and many species lack information even to be evaluated (i.e., “data deficient”). Here I proposed and tested the Rapid Endangered...
Previous attempts to understand the factors affecting the energetic cost of locomotion have found a direct link between the energetic cost and the mechanical work done during periods when the limb is in contact with the ground. However, when the limb is not in contact with the ground during the...
The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that is a member of the basic helix-loop-helix PER-ARNT-SIM (bHLH/PAS) protein family of cellular sensors. The AHR is conserved across multiple animal phyla and is required for proper vertebrate development. A structurally diverse group of chemicals, including polycyclic aromatic...
The focus of this dissertation was to understand protein function and structure ona molecular level. To do this successfully, a variety of biochemical and biophysicaltechniques were employed. A wide variety of techniques were applied to study theproteins of interest in this dissertation to probe protein-protein interactions, proteinfunction, protein structure, and...
Intrinsically disordered proteins (IDP) are a class of proteins that lack a three-dimensional structure and their prevalence and diverse functions in the cell have only been discovered relatively recently. The intermediate chain (IC) subunit of the microtubule motor protein complex dynein contains an N-terminal disordered region, N-IC, which is central...
Day 12-14 bovine embryos produce urokinase-type plasminogen activator (uPA) and
an uPA-plasminogen activator inhibitor (PAI) complex. The type of PAI, -1 or -2, in
the complex has not been determined therefore the objective of this research was to
identify the PAI produced by the Day 14 bovine embryo. In experiment...
In recent years considerable interest has been shown in the diversity of ammonia-oxidizing bacteria in soil communities. The majority of the research has been carried out in Northern Europe where soils have received high atmospheric inputs of nitrogen over the past two centuries. In contrast, although much work has been...
Litter nutrient dynamics contribute significantly to biogeochemical cycling in
forest ecosystems. These dynamics may be influenced by site attributes, litter nutrient concentrations, and soil nutrient availability either independently or synergistically. Litter nutrient dynamics were examined in two decomposition studies in temperate coniferous forests of Oregon. I used ¹⁵N-labelled litter of...
Understanding how N availability influences base cation stores is critical for long-term ecosystem sustainability. Indices of nitrogen (N) availability and the distribution of nutrients in plant biomass, soil, and soil water were examined across ten young, unpolluted Douglas-fir (Pseudotsuga menziesii) stands in the Oregon Coast Range spanning a three-fold soil...
The Hippo signaling pathway is an evolutionarily conserved regulator of cell growth, proliferation, and apoptosis. A key function of the pathway is to regulate the subcellular distribution and activity of Yorkie in Drosophila or Yes-associated protein (YAP) and transcription co-activator with PDZ-binding motif (TAZ) in mammals. The dysregulation of the...
The environmental health science community recognizes polycyclic aromatic hydrocarbons (PAHs) as a re-emerging class of environmental pollutants due to their persistence and prominence in mixtures of concern. Due to their widespread distribution in the environment, exposure to PAHs often occur as complex chemical mixtures. Exposures are linked to numerous adverse...
Circadian clocks coordinate molecular, cellular, physiological, and behavioral processes with the 24-hour solar day. While clock functions are well understood in young animals, it is not clear how aging or neurodegenerative disease affects the various levels of the circadian system. A common symptom of many neurodegenerative diseases including Alzheimer’s disease...
Skeletal muscle, the largest organ in the body in mass, is composed by 600 specialized muscles in humans with unique biochemical, physiological and metabolic identities. Skeletal muscles control body movement, locomotion, and nutrient balance. Muscle formation requires precisely orchestrated environmental signals and regulatory gene networks in time and space. Gene...
Cells represent microcosms of spatial and temporal structural organization, with the achievement of internal spatial organization relying upon a collection of macromolecular motor complexes to transport and localize components throughout the cell. Cytoplasmic dynein is one such motor complex, and is the principal ATP-dependent motor for retrograde transport along microtubules...
The symbiosis between cnidarians, such as corals and sea anemones, and photosynthetic dinoflagellates belonging to the genus Symbiodinium spp. is one of the most productive in the marine environment. This mutualistic endosymbiosis allow reef-building corals to lay down the foundation of coral reef ecosystems, which supports a highly biodiverse community...
Circadian clocks are endogenous molecular mechanisms that coordinate daily rhythms in gene expression, cellular activities, and physiological functions with external day/night cycles. Breakdown of circadian rhythms such as sleep/wake cycles is associated with the onset of several neurological diseases; however, it is not clear whether disruption of rhythms is a...
With respect to a multienzyme complex of deoxyribonucleoside triphosphate (dNTP) synthesis somehow juxtaposed with DNA replication sites, our laboratory has demonstrated the existence of a multienzyme complex in T4-infected E. coli, named the T4 dNTP synthetase complex, but the idea of direct linkage of dNTP synthesis to DNA replication and...
The Pacific Northwest has a relatively low diversity of primary freshwater fishes with most of the endemism and diversity in the Columbia River and Klamath River. However, the Oregon Coastal Subprovince defined as the coastal rivers from Miami River in the north to Sixes River in the south, has a...
Sustainable management of planted forests requires maintenance of soil function
to promote 1) root growth; 2) storage and cycling of water and nutrients; 3) optimal gas
exchange; and 4) biological activity. Soil quality measurements can be used to monitor
short- and long-term changes in these soil functions, allowing managers to...
Accurate chromosome segregation and cell cleavage are critical to maintaining genomic integrity. Both events involve the spindle apparatus, but the exact mechanics is as puzzling as the contradicting models proposed in the last two centuries. In this dissertation, current prevailing models of chromosome segregation and cell cleavage are tested using...
We evaluated the regeneration behavior and early growth rates of 10 non-pioneer canopy tree species in medium-height, semi-evergreen dry tropical forest in Quintana Roo, Mexico. These species provide timber and non-timber forest products for local communities and include evergreen and deciduous species with varied dispersal mechanisms. The species were Coccoloba...