Life Sciences Commons^™

Cadmium And Zinc Levels In The Hair Of Smokers And Nonsmokers, Neal R. Simonsen

Dissertations and Theses

To determine the relationship of tobacco and marijuana smoking to levels of cadmium and zinc manifested in hair samples, a study was conducted at Portland State University using atomic absorption spectrophotometry. 97 adult student volunteers participated in the main study.

Characterization Of Gram-Positive Bacterial Isolates From Burn Victims, Trisha A. Hannan

Dissertations and Theses

Streptococcus and Staphylococcus were collected from patients hospitalized at the Oregon Burn Center, Emanuel Hospital, Portland, Oregon, between October 27, 1980 and January 1, 1981. Forty-five isolates of Staphylococcus and twenty-one isolates of Streptococcus, Lancefield Group D, were included in the investigation.

The objectives of the investigation were: (i) to identify to the species level all isolates, (ii) to determine their susceptibility to antimicrobial agents, (iii) to test the organisms. over time for increasing resistance to silver, (iv) to determine, if present, a bacterium harbored within the burn unit (nosocomial bacterium), and (v) to determine any recognizable pattern of successive …

Variation In Branch Growth Characteristics Of Pinus Contorta Infected With Arceuthobium Americanum, Lynn Anne Larsen

Dissertations and Theses

Arceuthobium americanum is a flowering plant which parasitizes Pinus contorta (Lodgepole pine). This study examined branch performance of P. contorta infected to varying degrees with A. americanum.

A Genetic And Physiological Study Of An Arsenite Resistant, Uncoupled Mutant Of Escherichia Coli, Daniel Gordon Smiley

Dissertations and Theses

Chromosomally determined arsenate resistance in Escherichia coli is well characterized. Little, however, is known about chromosomally determined arsenite resistance in E. coli. Accordingly, spontaneous arsenite resistant mutants were selected in a plasmid free strain of E. coli. One mutant strain was analyzed in detail, genetically and physiologically. The mutation confering arsenite resistance was shown to be a single gene mutation. Genetic mapping studies using conjugation and transduction showed that the mutation was closely linked to the ilv region of the E. coli map.

The Metabolic Cost Of Behavioral Thermoregulation Of Body Temperature In The Northern Alligator Lizard Gerrhonotus Coeruleus, And How It Affects The Classical Concept Of Eurythermality, James Dudley Campbell

Dissertations and Theses

The effect of total metabolic cost expenditures on the precision of behavioral thermoregulation was investigated for the purportedly eurythermic Northern Alligator lizard (Gerrhonotus coeruleus). An operant apparatus was designed to test metabolic output at different heat reinforcement magnitudes. The mean T_B reflected in each trial was positively correlated to the length of reinforcement. The shuttle rate during each trial was inversely correlated to the length of reinforcement. The standard deviation and total metabolic costs did not vary significantly between trials undertaken at the same ambient temperature. Eurythermality in G. coeruleus is caused by fluctuations in preferred body temperature and …

Plasmid-Mediated Resistance To Arsenite And Arsenate In Escherichia Coli, Thomas Patrick Trezona

Dissertations and Theses

Bacterial strains resistant to arsenite, arsenate (or both) are readily isolated from nature. The resistance, in many cases, can be shown to be determined by conjugal plasmids. The mechanisms by which these plasmids confer resistance to arsenic compounds are entirely unknown. This study was undertaken to shed light on some of the physiological and genetic aspects of this resistance using plasmid-bearing strains of Escherichia coli which are highly resistant to both arsenite and arsenate. Most studies were carried out using E. coli J53 (R773) or the plasmid-free strain J53.