Two strains of Escherichia coli were studied to determine the effect of constitutive expression of the SOS DNA damage repair response on the activity of ribonucleotide reductase. Activity of the reductase and cellular deoxynucleoside triphosphate (dNTP) pools were both determined before and after exposure of the cells to ultraviolet radiation....
A relatively stable, persistent and historical problem with elevated NO₃⁻ concentrations in rural drinking wells in the southern Willamette Valley, Oregon is evident. What is the origin of NO₃⁻ in rural drinking water wells in this area? The answer to the question is not simple. Many non-point sources contribute to...
The City of Woodburn, Oregon's Wastewater Treatment Plant (WWTP) has been investigating several natural alternatives for improving effluent quality. Based on its current National Pollution Discharge Elimination System (NPDES) permit, the WWTP will require additional reduction of temperature and ammonia levels in the summer, especially in the critical month of...
Reducing future fire severity is a proposed ecological benefit of salvage logging following wildfire disturbance. Considerable debate continues over the ability of such management practices to achieve this objective given limited understanding of coarse woody detritus (CWD) dynamics, fuel bed alterations, and post-fire vegetative growth. The objective of this study...
There are many diagnostic approaches to evaluate the nutritional status of a forest stand. "Inference based on site and stand characteristics, visual symptoms, and foliar analysis are suggested to have the greatest utility in routine evaluations, while soil analysis and pot trial techniques should primarily be regarded as research tools...
The three most expensive wildland fire suppression seasons have occurred since 2000, each exceeding $1 billion. Many problems and issues have been highlighted including the grounding of the federal air tanker fleet, training problems with private contractors, overspending, poor management strategies, negative public pefceptions, and the inability to utilize the...
Arctostanhylos viscida is a broad-leaved, evergreen, sclerophylbus shrub which grows in northern California and the Siskiyou
Mountain region of southwest Oregon. After site disturbance, A. viscida competes with conifer regeneration, and may dominate a site for ninety years. This study examined the rate at which full site occupancy occurs in...
Ages, diameter growth, density, tree size, and species were studied in old-growth, plantation, and young natural Douglas-fir stands in three areas in western Oregon: the western and eastern Coast Range and the western Cascades. The purpose was to compare the development of these three stand types and to determine whether...
Many ecological systems are characterized by brief periods of increased resource availability called resource pulses. Empirical studies suggest that some populations of primary consumers grow rapidly in response to resource pulses, but others instead remain at low abundance despite increases in resource availability. Previous theory suggests that the lack of...
The ability of flavoenzymes to reduce dioxygen varies greatly and is controlled by the protein environment that can cause either a rapid (oxidases) or sluggish (dehydrogenases) reaction. Previously, a “gatekeeper” amino acid residue was identified that controls the reactivity to dioxygen in proteins from the vanillyl alcohol oxidase superfamily of...