Digital Commons Network^™

Changes In Populations Of Soil Acari During The First Year After Clearcutting, Sue Ellen Orlaske

Dissertations and Theses

Soil samples taken from a clearcut and adjacent uncut site of a Douglas Fir and Western Hemlock old growth forest in the Cascade Range of southern Washington showed greatly reduced adult and juvenile population densities of macro-phytophagous, microphytophagous, and predatory soil acari in the clearcut. These effects appeared to be due to high lethal summer litter temperatures and reduced pore spaces due to scarification. Also, the number of species of acari in the clearcut was lower than in the control after clearcutting.

Rare, Threatened And Endangered Vascular Plants In Oregon: An Interim Report, Jean L. Siddall, Kenton L. Chambers, David H. Wagner

Institute for Natural Resources Publications

This report on rare, threatened and endangered vascular plants in Oregon is a basic document in the process of inventorying the state's natural areas * Prerequisite to the orderly establishment of natural preserves for research and conservation in Oregon are (1) a classification of the ecological types, and (2) a listing of the special organisms, which should be represented in a comprehensive system of designated natural areas. The necessary ecological classification was published in the U.S. Forest Service Pacific Northwest Forest and Range Experiment Station document, "Research Natural Area Needs in the Pacific Northwest," by Dyrness et al. (1975). This …

Culture And Growth Of Closterium Ehrenbergii (Desmidiaceae), David Bruce Renstrom

Dissertations and Theses

Methods were devised for the isolation and pure culture in defined mineral medium of Closteriurn ehrenbergii Menegh (Chlorophyceae). The effect of pH, type of nitrogen source, nitrate concentration, total hardness, and various buffers on growth were investigated. Best growth rates were obtained at pH 8 to 9, but good growth was observed even at pH 9.4. Nitrate, ammonia, or urea nitrogen could be utilized, but at concentrations greater than 10^-2M urea was toxic to growth. At higher concentrations of ammonia and nitrate longer lag phases of growth were obtained but eventual higher cell yields were obtained. Good growth …

A Comparison Of Dramatic Storytelling And Puppet Storytelling As A Means Of Teaching Selected Nutritional Concepts, Edith M. Martin

Dissertations and Theses

The present study investigated the basic question: Will preschool, kindergarten, and first grade students have a greater increase in knowledge of selected nutritional concepts as a result of viewing a puppet story than a similar composite will have when the same material is presented via dramatic storytelling?

Ascorbic Acid, Lipid Peroxidation, And Aging, Brian Evan Leibovitz

Dissertations and Theses

The role of ascorbic acid with regard to lipid peroxidation and aging has been examined. A thorough literature analysis indicates that free radical-induced lipid peroxidation is a plausible biochemical explanation for aging. Lipid peroxidation causes cellular damage due to altered enzyme activities, error-prone nucleic acid metabolism, and membrane dysfunction, as well as the accumulation of aging pigments in the lysomes. Ascorbic acid, a water soluble free radical quencher, was examined with regard to carbon tetra-chloride-induced lipid peroxidation and in vivo aging. Carbon tetrachloride, a well-known free radical inducer, caused marked increases in the ration of oxidized/reduced vitamin C only …

Androgen-Induced Immunosuppression, Debra Ann Weyant

Dissertations and Theses

It is well established that females are more immunocompetent than males as evidenced by higher humoral antibody titers, lowered susceptibility to infection, and more efficient graft rejection.

Furthermore, females also exhibit a much higher incidence of autoimmune disease. These observations have led investigators to believe that the male hormonal environment may play a key role in the regulation of immune response. For this reason, this study is concerned with the expression of autoimmunity and of immune function in the mouse.

This study included the New Zealand Black (NZB) mouse strain, as an animal model for human SLE, as well as …

The Allelopathic Potential Of Rhododendron Macrophyllum In A Western Cascades Clearcut, Ivan W. Clark

Dissertations and Theses

The purposes of this study were to determine if Rhododendron macrophyllum has the potential to inhibit the growth of other species through the production of water-soluble toxins which are leached out of its litter by rainfall, and to determine if this potential is realized in the field. The study was therefore composed of two part: 1) a series of bioassays to determine the presence an activity of water-soluble phytotoxins in R. macrophyllum leaf litter, and 2) a field study to describe vegetational patterns associated with R. macrophyllum in a western Cascades clearcut.

Some Physical And Biological Factors Affecting Red-Tailed Hawk Productivity, Stewart Wayne Janes

Dissertations and Theses

Various physical and biological factors affecting annual productivity in a Red-tailed Hawk population in north-central Oregon were investigated. The percentage of the population successfully fledging one or more young was the most important factor in determining the number of young fledged per pair in a given year. Neither clutch size nor the number of young fledged per successful nest varied significantly. Percent pair success was correlated with several January weather variables. A cold and dry January is positively correlated with Red-tailed Hawk productivity. This is apparently related to the onset of rapid vegetative growth and this in turn is positively …