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Factors Affecting The Population Of Raptorial Birds On Sauvie Island, Oregon, Jeffry Gottfried

Dissertations and Theses

This study is an analysis of the various factors affecting the population of raptorial birds on Sauvie Island, Oregon. A census of diurnal and nocturnal raptors was carried out along with an analysis of food habits. Once the major prey species were determined they were censused, and the effects of the land management practices on their numbers was investigated. In addition, 100 randomly selected nest boxes were sampled so as to determine the extent to which raptors were making use of them. Red-tailed hawk and Great Horned Owl nests were located.

It was found that four diurnal raptors and three …

Euryhelmis Cotti N. Sp. (Trematoda: Heterophyidae) With Observations On Its Life Cycle, Michael Joseph Simon

Dissertations and Theses

Fish of the genus Cottus were found infected with heterophyid metacercariae. Laboratory animals were infected with the metacercariae, and adult heterophid trematodes were recovered. These flukes were found to represent an undescribed species of the genus Euryhelmis. Various streams in the Willamette Valley and coastal areas were sampled for infected Cottus sp. Snails of the genera Oxytrema and Fluminicola were collected. Several possible definitive hosts were examined. A partial review of the subfamily Apophallinae and a complete review of the genus Euryhelmis are presented. Euryhelmis cotti n. sp. is placed in the subfamily Apophallinae, and its life cycle …

Polychlorinated Biphenyls: Uptake By Daphnia And Residues In Crayfish From The Willamette River, John J. Salmon

Dissertations and Theses

Polychlorinated Biphenyls (PCB's) are organochlorine molecules which find various industrial and product applications. PCB's are of concern to biologists because they are toxic substances which have become global contaminants. They are also of concern to biologists and analytical chemists because they interfere with the determination of some organochlorine pesticide residues. PCB's were discovered to be environmental contaminants after they showed up as unidentified peaks in pesticide analysis using gas-liquid chromatography with an electron capture detector (GLC-EC).

In the present experiment standard GLC-EC techniques were used to assay PCB's in Daphnia experimentally contaminated in the laboratory and in crayfish from the …

The Life Cycle Of Lissorchis Heterorchis, Macy And Krygier (1969), Brendan P. H. Onyejekwe

Dissertations and Theses

Many Flumenicola virens (Lea) collected from Crystal Springs Creek and Tualatin River, Portland, Oregon, were found to shed large numbers of a species of microcercous cercariae containing refractile granules. They resembled the cercariae of Triganodistomum mutabile (=Lissorchis mutabile Cort, 1918 as described by Wallace (1939), and subsequent experiments proved that they were the larval stages of what was described by Macy and Krygier (1969), as Lissorchis heterorchis. Encystment of these cercariae was induced experimentally in uninfected adult brown planarians collected partly from Crystal Springs Creek and partly from Carolina Biological Research Station in Gladstone, Portland, Oregon. Adult flukes were obtained …

A Taxonomic Study Of Two Nominal Subspecies Of Pikas (Ochotona Princeps) In The Cascade Mountains Of Oregon, Richard M. Coots

Dissertations and Theses

Pikas from four colonies in the Cascade Mountains of Oregon were examined. Two colonies were chosen from within the geographical distribution of two nominal subspecies. A discriminate analysis of morphological measurements taken from the specimens showed that each colony could be distinguished from each other. Each colony studied showed more intra-colony similarity than inter-colony similarity regardless of distance separating the colonies or subspecies designations. The results indicate that the validity of subspecies designations for this species can be questioned.

Mutual Exclusion Between Salmonberry And Douglas-Fir In The Coast Range Of Oregon, Kenneth Ray Still

Dissertations and Theses

One serious problem faced by the forest industry in the Pacific Northwest is poor regeneration of commercial trees on land which is harvested and subsequently dominated by brush species. In Coastal Oregon, salmonberry is one of these brush species. Detailed investigations of field sites indicate that light intensity in the brush stands was low but sufficient for germination and early growth of Douglas-fir seedlings and soil moisture percentages and nutrient levels were high enough to support early Douglas-fir growth. Laboratory tests demonstrated the presence of leachable phytotoxins in the leaves of salmonberry. The hypothesis resulting from this study is that …

Repression Of Β-Galactosidase Synthesis In Escherichia Coli By Salicylates, Joan Carlyn Olson

Dissertations and Theses

Salicylic acid, and to a lesser extent aspirin, have been shown to repress β-galactosidase synthesis in Escherichia coli. The repression is not due to decreased inducer uptake, nor does it result from competition with inducer for repressor. Dinitrophenol does not exert similar effects on β-galactosidase synthesis. Cyclic adenosine 31, 51-monophosphate partially relieves the repression. The extent or the relief by cyclic adenosine monophosphate seems to depend on the concentration of salicylic acid. This indicates there may be direct interaction between the actions of cyclic adenosine monophosphate and salicylic acid in E. coli cells.

A Taxonomic Study Of The Marine Algae Of Netarts Bay, Oregon, Charles Jerome Kunert

Dissertations and Theses

Gathering taxonomic data is fundamental to any biological or ecological research. It was the intent of this paper to increase the storehouse of taxonomic information by studying the marine algae of one section of the Oregon coastline. Netarts Bay was chosen because of its accessibility and generally primitive nature. It is in an area of Oregon largely untouched by phycologists and so offered an opportunity for original research.

Techniques of collecting and preserving specimens were kept as simple as possible, thus allowing a proportionately greater amount of the available time to be spent in the classification of the organisms. The …