We examined how the experiences of World War II and Korean War veterans,
including prewar, warzone, and postwar factors, affected PTSD symptoms in later life.
This dissertation consists of two studies. In Study 1, four different hypotheses from a
lifespan approach were examined (King et al., 1996): stress evaporation (only...
Waterborne fecal contamination poses serious risks to human health and can disrupt aquatic ecosystems. Molecular marker methods are widely used to identify and, in some cases, quantify the sources of contamination and guide management decisions regarding water resource protection. However, methods to detect some likely sources of fecal contamination such...
Throughout many of the world’s mountain ranges snowpack accumulates during the winter and into the spring, providing a natural reservoir for water. As this reservoir melts, it fills streams and recharges groundwater for over 1 billion people globally. Despite its importance to water resources, our understanding of the storage capacity...
Continental flood basalts represent short-lived but immense blasts of mafic magma to the continental crust. The youngest and smallest continental flood basalt worldwide, the Columbia River Basalt, initiated with the eruption of the most mafic member, the Steens Basalt (~16.9 Ma). The Steens Basalt is exposed in southeast Oregon, southwest...
Senecio jacobaea (tansy ragwort) is a common weed in the
Pacific Northwest that contains toxic pyrrolizidine alkaloids
(PAs). Jacobine, the major PA in Senecio jacobaea, was incubated
with rat liver microsomes and metabolites were isolated by high
performance liquid chromatography (HPLC) and identified by mass
spectrometric analysis. Metabolites included a...
This study is an effort to characterize the magma sources, plumbing system, and eruptive behavior of Mount Hood, a low-explosivity recharge-dominated volcano in the Oregon Cascades. The three manuscripts in this dissertation make use of melt inclusion data, phenocryst compositions, and whole rock petrology and geochemistry to build a schematic...
I focus on addressing knowledge gaps relating to management of cryptogams in Oregon's public lands in Pseudotsuga menziesii-Tsuga heterophylla forests on the west side of the Cascade Range and dryland steppe in the Cascade Range's rainshadow.
While a great deal of research has illustrated the importance of late-successional forests for...
Sagebrush steppe ecosystems are one of the most widespread but endangered ecosystems in North America. A diverse array of human-related stressors has gradually compromised these ecosystems' resilience to disturbance and invasion by Bromus tectorum (cheatgrass). The role of the foundational shrub Artemisia as a driver of herbaceous community structure and...
Magnetotellurics is used in two geologic settings on scales ranging from 1000-km tectonic structures to local features hundreds of meters wide. These areas are the Midcontinent Rift System (MRS) and its related mantle plume in the northern Midwestern United States and Newberry Volcano in central Oregon.
The MRS study uses...
The sinking of the RMS Titanic has achieved a difficult feat – it has remained culturally relevant. The dedication of the general public to understanding Titanic is evident in many avenues of popular and consumer culture. For those individuals who did not get enough of the 1997 Titanic movie, there...