Understanding the impact of humans on the environment has long been a topic of scholarly interest and debate. As environmental problems mount, accounts of historic ecological conditions and the factors of change become increasingly useful. This study considers competing schools of interpretation about human impacts on ecological landscapes and develops...
The transmission of strawberry mottle virus (SMV) to Fragaria vesca
L. by Chaetosiphon thomasi and C. fragaefolii was studied to determine
differences between the two species. Acquisition, inoculation, and
retention phases of transmission were described. In all phases, C.
fragaefolii was found to be the more efficient vector.
Mean transmission...
Tall fescue [Schedonorus arundinaceus (Schreb.) Dumort.] is an important forage and turf grass seed crop in Oregon. Use of the stem-shortening plant growth regulator (PGR) trinexapac-ethyl (TE) has gained broad acceptance by tall fescue seed producers in Oregon and elsewhere world-wide as an economical agent of seed yield enhancement through...
Establishing true depths of recovered sediments is critical to determining sedimentation rates for high-resolution paleoclimatic
studies. We have corrected the composite depth scale, which accounts for the entire continuous sedimentary sequence, so that sediment
depths are consistent with logging depths, or "true" depths. We accomplished this by taking advantage of...
This thesis presents two related studies on the methodology for creating, and
subsequently analyzing, an inverse food web model of an intertidal seagrass bed. The first study (Chapter 2) describes, for the first time in the literature, a method for incorporating isotopic information gained from Bayesian mixing models into an...
Measurements on growth traits up to 41 years of age
from 68 progeny sites in eight first-generation breeding
zones of coastal Douglas-fir (Pseudotsuga menziesii
[MIRB.] FRANCO var. menziesii) in the US Pacific Northwest
were used to investigate age trends of genetic parameters
and to determine optimum age of selection. Heritabilities...
The reproductive performance of four strains of broiler breeder
males (BBM) were compared when housed in individual cages from 22 to
56 weeks of age (WOA), and fed Asi libitum 7% crude protein (CP) diets
with 1985, 2424, 2868 kilocalories (kcal) metabolizable (M) energy (E) per
kg of feed and...
Through this dissertation, the quality of freely available physical activity promotion web articles that lay adults would likely locate online was critically appraised and theoretically analyzed. Three broad categories were considered. They were 1) message consistency with national health guidelines for physical activity; 2) suitability for health-related communication; and 3)...