The subsurface microbial biosphere in the igneous oceanic crust has implications for global geochemical cycling, early life on Earth, and the search for life on Mars. Microscopic evidence of a subsurface microbial ecosystem includes biotic alteration textures associated with basaltic glass. The exact conditions in the basaltic layer that make...
Many conditions affecting hydrogen (H₂) production by the cyanobacterium, Synechocystis sp. PCC 6803, were optimized to yield maximum H₂ accumulation. Biological H₂ production from photosynthetic species is a promising form of renewable energy since an abundant supply of sunlight hits the Earth every day, and photosynthetic bacteria can harness this...
The atmospheric transport and deposition of semi-volatile organic compounds (SOCs), including current and historic use pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), to mountain ecosystems may result in the exposure of tadpoles to these SOCs. This exposure has been implicated in amphibian population declines in California. Tadpoles encounter...
The primary goal of this study is to assess the impact of a subduction component
added to the mantle wedge beneath the Oregon Cascades to the composition and fO2 of
primitive Cascade basalts. Olivine-hosted melt inclusions from compositionally diverse
basalts across the Cascade arc (~100 km) are utilized in an...
For the past several years vegetable growers in Oregon's Willamette Valley
have experienced reduced yields in their sweet corn plantings. We conducted
studies to 1) describe the symptomology and etiology of the disease, 2) test a root
rot rating system we developed to evaluate factors in the disease syndrome, and...
When Douglas-fir and red alder grow in mixture, interactions between the two species can be competitive, facilitative, or a combination of both over time. A number of factors have recently led to increased interest in managing these two species together for commercial production, and ongoing investigations are yielding important information...
Seed piece to plant transmission of the potato late blight pathogen, Phytophthora infestans, occurred with isolates of the clonal lineages US-8 in Oregon and US-11 in Washington in field trials. Average transmission rate across potato cultivars was 0.5 and 2.4% with US-8, and 0.8 and 1.0% with US-11 in 1999...
In this project, we have investigated three different techniques for plagiarism detection and have compared its effectiveness against that of an unaided human grader. The techniques investigated were word frequency analysis, sentence inclusion analysis and sub string inclusion analysis. We found that a combination of word frequency analysis and sub...
In plantation forestry, rapid growth rate is favorable for wood production, but may decrease wood density, which is an important indicator of wood quality for both pulp and solid wood products. I looked for (1) differences in radial patterns of wood
density between planted and naturally grown Costa Rican tree...
Virus contamination in a potato breeding program can seriously
disrupt the variety development process. Experiments were conducted
from 1989 through 1993 to: evaluate the extent to which Potato
Leafroll Virus (PLRV) and Potato Virus Y (PVY) can invade a breeding
program, determine viral spread within hills and within individual
tubers,...