In the heat of summer in the Rogue Valley, yellow starthistle (Centaurea solstitialis) raises heads of brilliant yellow flowers rigidly defended by sharp spines. Although bees reap double benefits of nectar and pollen during a season when most native plants no longer are flowering, this nonnative weed is a threat...
Squarrose knapweed, introduced from southwest Asia and the Middle East, became weedy in northern California and Utah by the early 1950s. How it
was originally introduced is not known, but its spread in California
and Utah was associated with the trailing of range sheep. Squarrose knapweed grows in the Klamath,...
When observers monitor for infrequent signals for extended durations, they generally experience a decline in detections over time. This decline is termed the vigilance decrement. Current theories of vigilance attribute the decrement to three potential mechanisms: conservative shifts in response bias, losses of sensitivity, and an increased rate of attentional...
This thesis outlines the development of new elastomeric materials and manufacturing processes for soft robotics. Specifically, this work describes the development of custom material formulations for use in additive manufacturing, additive manufacturing processing techniques for silicone elastomers, and multi-component additive manufacturing techniques. Material synthesis and processing is a gap in...
Centaurea solstitialis L. (yellow starthistle) and C. × moncktonii Britt. (meadow knapweed) are members of the genus Centaurea in the Asteraceae family. Both species have become serious management concerns as invasive species in North America, often displacing native vegetation and costing land managers millions of dollars to eradicate. Seven plants...
Yellow starthistle (Centaurea solstitialis L.) is a member of the knapweed
(Centaurea L.) complex. It is poor forage for all livestock and causes
“chewing disease,” a nervous disorder, in horses. Yellow starthistle infests
millions of acres in California and the Pacific Northwest. Infestations range
from scattered plants to dense stands...
In many areas of the Western U.S., diffuse knapweed (Centaurea diffusa Lam.)
has invaded into plant communities dominated by bluebunch wheatgrass
(Pseudomegnaria spicata [Pursh] A. Love). The objectives of this study were to compare
growth response of both species when grown under altered moisture and temperature
regimes while in the...
Wild garlic (Allium vineale) was introduced from Europe where it was used as a food flavoring. It is found in pastures, lawns, ornamental beds, and several cultivated crops. It grows west of the Cascades from Vancouver Island south into northwest Oregon.
The encroachment of alien weeds onto western rangelands is one of the most perilous and perhaps least recognized problems facing land managers today. Oregon rangelands are under siege from ever-increasing numbers and distribution of exotic weeds. They threaten Oregon's economy and environmental quality by reducing livestock forage, wildlife habitat, watershed...
A method was developed for the measurement of 19 parent PAHs (PAHs) and 34 hydroxylated
PAHs (OH-PAHs) in urine and personal air samples of particulate matter less than 2.5 um in
diameter (PM[subscript 2.5]) using GC-MS and validated using NIST SRM 3672 (Organic Contaminants in
Smoker’s Urine) and SRM 3673...
Full Text:
-glucuronidase/arylsulfatase was purchased from Roche Diagnostics
Corporation (Indianapolis, IN). Acetate