My dissertation focuses on the evolutionary forces that have shaped the chemical signaling system of plethodontid salamanders. Pheromones mediate two phases of plethodontid reproduction: mate attraction prior to courtship and female persuasion during courtship. Substrate-borne chemical signals are believed to play an important role in mate attraction for these animals....
Asthma prevalence in children under age 18 has risen steadily in the U.S. since the mid-1970s. Most researchers attribute this increase to air pollutants, socioeconomic status or urban residence. This study examined asthma prevalence in Lane County, Oregon, using children's asthma hospital discharges (1990-1995), and data from 10 of 16...
The International Commission on Radiological Protection (ICRP) has modeled twelve reference animals and plants (RAPs) with simple geometric shapes to be used when estimating radiation dose to non-human biota (NHB). In recent years, there has been interest in creating more realistic models in order to better understand the radiation interactions...
The navicular drop test (NDT), Feiss' line (FL) and standing foot angle (SFA)
are clinical tests used to estimate the amount of pronation via inferior displacement of
the tarsal navicular. Thirty-two patients (female and male, ages 18-65) who sought
medical treatment for lower extremity pathologies participated in the study that...
Species and cultivar combinations have been relatively well studied, though little is known about the influence of spatial arrangement on agricultural or native plant mixtures. The effect of spatial pattern on mixtures was explored in three experiments. In the first two, agricultural and native plants were planted in two-way mixtures...
The approximation of a continuous function, in the maximum
norm, by continuous splines in the Everett Interpolation Form is considered.
The topics of characterization, uniqueness, and calculation
of best approximations are investigated. Since uniqueness fails, a
new vector-valued norm, which yields uniqueness, is introduced.
A brown and burn site preparation project was monitored on an
alder-dominated brushfield in the western Oregon Coast Range. Prefire
vegetation was surveyed, and the fuel complex created by felling
and aerial application of herbicides was evaluated. Post-fire vegetation
was examined during the four months following the August, 1974,
fire....
In 1990, the Clean Air Act (CAA) Amendments authorized the regulation of 188 hazardous air pollutants (HAP). Exposure to HAPs at sufficient concentrations and durations can increase both cancer and serious adverse non-carcinogenic effects. The purpose of this study was to conduct a human health risk assessment using data of...
Antineutrino detectors could provide a valuable addition to current safeguards
regimes. Antineutrinos are an attractive emission to monitor due to their low
interaction cross-section that prevents them from being shielded and the dependence
of their spectrum on the power level and isotopic content of a reactor core. While
there are...
Resource availability follows seasonal cycles in environmental conditions. To align physiology and behavior with prevailing environmental conditions, seasonal animals integrate cues from the environment with their internal state. One of the systems animals use to integrate those cues is the hypothalamus-pituitary-adrenal (HPA) axis and its primary effector, glucocorticoid hormones. The...