This study quantifies the short-term effects of low-, moderate-, and high-severity fire on carbon pools and fluxes in the Eastern Cascades of Oregon. We surveyed 64 forest stands across four fires that burned 41,000 ha (35%) of the Metolius Watershed in 2002 and 2003, stratifying the landscape by burn severity...
Multipurpose management of hydrosystems face a number of uncertainties related to hydrologic variability and nonstationarity. Anticipated air temperature increases in the Pacific Northwest region are projected to alter the timing and quantity of streamflow associated with precipitation shifting from snow to rain, including shorter winter runoff periods, earlier spring runoff,...
This thesis presents the results of quantum-mechanical first principles calculations
of optical, electronic and mechanical properties of organic molecules and solids, which have
diverse potential applications such as photovoltaics, flexible electronics, and mechanical
catalysts with applications in force sensors and self-healing materials.
The electronic and optoelectronic properties of organic thin...
For the first time in several years, the El Niño-Southern
Oscillation did not dominate regional climate conditions
around the globe. A weak La Niña dissipated to ENSOneutral
conditions by spring, and while El Niño appeared
to be emerging during summer, this phase never fully
developed as sea surface temperatures in...
Chilodontidae is a small family of eight described characiform species popularly
known as headstanders. These small to moderately sized fishes are well known to
aquarists, who prize their striking spotted pigmentation and unusual behaviors, and to
systematists, who have revised both chilodontid genera in recent memory and studied
their phylogenetic...
SAR11 Alphaproteobacteria are the most abundant aerobic chemoheterotrophs in ocean surface waters. Previous studies have indicated SAR11 cells play an important role in marine carbon cycling and consume up to half of some common dissolved organic compounds, such as amino acids. During sequencing of the first SAR11 genome, genes for...
The most frequent cause of pseudomembranous colitis is Clostridium difficile (C. difficile) infection. This type of colitis is characterized by an endoscopic pattern of numerous small, yellowish or whitish plaques diffusely distributed, which typically compromises the rectum extending to proximal colon. Occasionally, the pseudomembranes compromise only the transverse or right...
Clostridium difficile is an important nosocomial pathogen that has become a major cause of antibiotic-associated diarrhea.
There is a general consensus that C. difficile spores play an important role in C. difficile pathogenesis, contributing to infection,
persistence, and transmission. Evidence has demonstrated that C. difficile spores have an outermost layer,...
The increased severity of Clostridium difficile infection is primarily attributed to the appearance of an epidemic strain characterized as PCR ribotype 027. The only report that identified epidemic C. difficile ribotype 027 in an American country outside of North America comes from Costa Rica, raising the possibility that strains 027...