Life Sciences Commons^™

Indicators Of Nutrient Limited Plankton Growth In Lakes Near Mount Saint Helens, Washington, Kurt Davis Carpenter

Dissertations and Theses

Several lakes located in the blast zone of the 1980 eruption of Mount St. Helens were studied to determine if the plankton in the lakes were limited in their growth by nitrogen or phosphorus availability. Long term nutrient enrichment experiments were performed on lake water from five lakes and measures of chlorophyll-a, carbon fixation, and nutrient uptake were used to evaluate the extent of limitation. Nutrient concentrations, ratios, and uptake from 14 lakes provided additional evidence for limitation by nitrogen and/or phosphorus. The physical, chemical, and biological characteristics of the lakes were also examined to monitor the return of these …

Investigations On Glycolipid Production By Pseudomonas Putida Grown On Toluene In Batch And Continuous Culture Conditions, Keith Foorest Dockery

Dissertations and Theses

Utilization of toluene by Pseudomonas putida as its sole carbon and energy source affects morphology, outer membrane protein composition, and glycolipid production. Two strains of P. putida were found to utilize toluene and to coexist in continuous and batch culture. The two strains were designated translucent and opaque, based upon their readily identifiable coloration when grown on Luria agar. The translucent strain was the dominant strain in continuous culture conditions. The outer membrane proteins of P. putida were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis. When toluene is the carbon and energy source, the trend in protein composition was …

Changes In Proteins Associated With Nitrogen Fixation And Iron Nutrition In The Marine Cyanobacterium Trichodesmium, Karen Marie Elardo

Dissertations and Theses

This investigation tested the hypothesis that iron, as a micronutrient, will affect proteins in Trichodesmium and therefore affect nitrogen fixation. Changes in proteins that are a result of iron enrichment were compared to naturally occurring diel changes. Alterations in the iron protein of nitrogenase were compared to nitrogen fixation rates using the acetylene reduction technique. The observed changes in proteins were compared in Trichodesmium colonies from the Caribbean Sea and the Sargasso Sea.

Trichodesmium colonies were monitored for protein and iron content over a diel period on two cruises. The changes in protein and iron content in Trichodesmium colonies were …

A Comparison Of Neutrophil Migration In The Mouse In Response To Infection With Three Species Of Trichinella, Jon Darin Prulhiere

Dissertations and Theses

The Genus Trichinella is currently thought to consist of 8 separate species. Several methods have been used to help differentiate these. In this study the ability of three of these species, T. spiralis, T. pseudospiralis, and T. sp. 3 to independently infect MRL++ mice was compared at 5, 7, 11, 18 and 20 days post infection (dpi) with the hope of discovering new distinguishing characteristics. Of interest was the development of inflammation through the accumulation of neutrophils associated with larvae of Trichinella in mouse skeletal muscle. This was evaluated with routine histological stains, endogenous peroxidase staining and immunohistochemical …

The Dna Sequence Required For The Maximal Transactivation Of The Vp5 Gene Of Herpes Simplex Virus Type 1, Shin Chen

Dissertations and Theses

A regulatory element involved in the transcriptional activation of the major capsid protein (VP5) of herpes simplex virus type 1 was identified and characterized in this research project. Gel mobility shift assay with nuclear extracts from both uninfected and HSV-1 infected HeLa cells identified two major protein-DNA complexes involving the VP5 promoter. No viral specific complex found. DNase I and orthophenanthroline-Cu⁺ footprint analyses in the same laboratory revealed that the two complexes involve a single binding site, GGCCATCTTGAA, located between -64 and -75 bp relative to the VP5 cap site. To determine the function of this leaky-late binding site …

Chlorophyll Characterization Of Three Mistletoes And The Chloroplast Ultrastructure Within Aerial And Endophytic Tissues Of Phoradendron Juniperinum, Wesley Emanuel Dubbs

Dissertations and Theses

The aerial shoot pigments of three epiphytic mistletoes and their hosts were examined and the results were found to concur with earlier reports. Emphasis was placed on the mistletoe Phoradendron juniperinum. Absorbance spectroscopy indicated a very similar ratio of pigments in both the aerial tissue of the mistletoe and its juniper host. Spectroscopic examination found the presence of chlorophyll in the endophytic tissue of the genus Phoradendron for the first time. Total chlorophyll concentrations of the endophytic tissue of Phoradendron juniperinum were found to be approximately 10% that of aerial shoots. However, chlorophyll a/b ratios of endophytic tissue were …

Investigations Of Factors Affecting The Transcriptional Regulation Of Herpes Simplex Virus Type 1 Βγ (Leaky-Late) Genes, Rosemary Ann Lown

Dissertations and Theses

Herpes simplex virus type 1 (HSV-1) is a virus commonly causing cold sores in humans, however, virulent infections are known to produce debilitating encephalitis and death. HSV-1 transcription is carried out by the host cell RNA polymerase II in a tightly regulated temporal cascade. The first genes transcribed, the a genes, are activated in the absence of viral DNA synthesis. Transcription of the other temporal classes, the β, βγ, and γ genes is dependent upon the protein products of the a genes for activation. The purpose of this study was to investigate the factors that contribute to this rigid regulation …

A Study Of Understory Plant Recovery After A Forest Fire In The Columbia River Gorge, Mark Alan Pittsenbarger

Dissertations and Theses

Between October 9, 1991 and October 16, 1991 a fire burned 577 hectares in the Columbia River Gorge near the west end on the Oregon side. All of the area burned consisted of second growth Pseudotsuga menziesii and the accompanying understory. This was the first disturbance of this magnitude in this part of the Columbia River Gorge since 1902. The purpose of this study was to examine the pattern of understory recovery in the first two years following the fire. This study also sought to learn: 1) how Pseudotsuga menziesii seedlings are recruited into the population, 2) how quickly the …

Extracellular Matrix Proteins Of The Nurse Cell Capsule In Trichinella Spiralis Infections, Mary Louise Taylor

Dissertations and Theses

The infectious first-stage larvae of the nematode Trichinella spiralis is an intracellular parasite of altered skeletal muscle. Invasion of the muscle cell initiates a series of morphological changes in the host muscle cell which ultimately results in a specialized unit called the nurse cell. The completed nurse cell consists of a collagenous capsule, matrix of altered sarcoplasm, and a circulatory rete.

The purpose of this study was to determine the types of collagen present in the nurse cell capsule. Additionally, the presence of the glycoproteins, laminin and tenascin was determined. This study also sought to demonstrate the location of the …

Relationships Between Avian Diversity And Vegetational Parameters In Forested Patches Of The Tualatin Mountains, Oregon, Jerry Sexton Fugate

Dissertations and Theses

The effect of contiguous forested habitat area on local avian diversity and species richness in the Tualatin Mountain area of northwestern Oregon was investigated. Observations of eight forested stands representing seven area values (1, 2, 7, 14, 18, 24 and 40 hectares) were made during the spring and summer of 1991 and 1992. The variables measured were chosen in an attempt to show possible relationships between vegetation factors, spatial patterns and bird communities. Kendall's rank correlation coefficients were used to analyze the data. Avian species richness and diversity were significantly correlated with forest stand (patch) size. The only significant correlation …

Evidence For The Eutrophication Of Selected Coastal Dunal Lakes: Historical Comparison Of Indices For Nutrient Enrichment, Steven Gregory Dagget

Dissertations and Theses

Three coastal Oregon dunal lakes, Mercer Lake, Munsel Lake, and Woahink Lake, were studied in an effort to determine if eutrophication has occurred since initial studies were conducted in 1938 and to determine each lake's current trophic status. Data collected in 1991 and 1992 for phytoplankton primary productivity; chlorophyll a; phytoplankton species, biovolumes, and densities; nutrients; optical characteristics; and dissolved oxygen were compared with historical data sets. Additional data for zooplankton, benthic invertebrates, and other relevant limnological data were used to more completely characterize each lake.

Phytoplankton primary productivity measurements indicate that biological productivity has increased at each lake …

Studies On The Role Of Cellular Factor, Yy1, In Herpes Simplex Virus Type 1 Late Gene Expression, Xuehui Liu

Dissertations and Theses

The herpes simplex virus 1 (HSVl) VP5 gene codes for the major viral capsid protein. Understanding of the mechanism of how the VP5 gene is regulated in host cells will help us to understand the molecular action of the HSV 1 life cycle and its interplay with the host cell gene expression machinery (transcription and translation). This may ultimately provide scientific bases for both better prevention and cure of HSV 1 caused diseases. Previous work from Dr. Robert L. Millette' s laboratory has indicated that a 164 base pair region of the VP5 promoter gene could activate the transcription of …

Recovery Of Marsh Vegetation At Malheur Lake Following An Extended Flood, Sherry Vlasta Spencer

Dissertations and Theses

Water levels of Malheur Lake in southeastern Oregon fluctuate widely with seasonal and cyclic climatic changes. Seven years of severe flooding from 1978 to 1984 produced the highest water levels in recorded history and covered almost all marsh vegetation. Seven years of drought followed the flooding, and by 1992 the water level had dropped to the lowest point in nearly 60 years. A survey of vegetation colonizing the lakeshore as flood water receded was conducted from 1989 to 1992 to describe the reestablishment of marsh vegetation. Six transects were placed in three different ecological units of the lake. Frequency and …