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Full-Text Articles in Life Sciences

Characterization Of A New Freshwater Methanogen, Methanogenium Wolfei Sp. Nov., Theodore B. Moore Jul 1985

Characterization Of A New Freshwater Methanogen, Methanogenium Wolfei Sp. Nov., Theodore B. Moore

Dissertations and Theses

A recently isolated freshwater methanogenium species, Methanogenium wolfei, is characterized. Cells were irregular cocci, measuring 1.5 to 2.0 micrometers in diameter. No motility was observed, but 1 to 2 flagella per cell were observed after staining with Gray's Flagella Stain. Colonies formed by this species were small, shiny, and green-brown in color. Formate or hydrogen plus carbon dioxide served as substrates for growth. The optimal temperature for growth was found to be 45 degrees centigrade with minimal growth below 30 degrees centigrade and above 55 degrees centigrade. The optimal pH for growth was determined to be 6.8. Optimal growth was …


Aspects Of Cardiovascular Oxygen Transport In Vertebrates, Michael Scott Hedrick May 1985

Aspects Of Cardiovascular Oxygen Transport In Vertebrates, Michael Scott Hedrick

Dissertations and Theses

The hematological and rheological characteristics of blood from a number of vertebrates was compared to assess possible species differences in blood viscosity that may influence cardiovascular oxygen transport. Nucleated red blood cells (RBCs) were more viscous (measured by cone-plate viscometry) in comparison with enucleate (mammalian) RBCs at hematocrits greater than 40% when measured at equivalent temperatures. The lower viscosity of enucleate RBCs is attributed to an enhanced deformability of enucleate cells in comparison to nucleated cells.


Partial Purification And Characterization Of F₄₂₀-Dependent Nadp Reductase From Methanobrevibacter Smithii Strain De1, Scott D. Sheridan Jan 1985

Partial Purification And Characterization Of F₄₂₀-Dependent Nadp Reductase From Methanobrevibacter Smithii Strain De1, Scott D. Sheridan

Dissertations and Theses

The F420-dependent NADP reductase of Methanobrevibacter smithii has been partially purified employing a combination of affinity chromatography with Blue Sepharose (Cl-6B) and molecular sieve chromatography with Sephacryl S-200, The enzyme, which requires reduced F420 as an electron donor, has been purified over 145 fold with a recovery of 6%. A molecular weight of 120,00 for the native enzyme was determined by Sephacryl S-200 chromatography. A subunit molecular weight of 28,200 was determined by SDS-PAGE, indicating that the native enzyme is a tetramer. The optimal temperature for enzymatic activity was found to be 45°C, with a pH optimum …


The Analysis And Use Of Methodologies For The Study Of The Diets Of Long-Eared Owls From Three Environments In North Central Oregon, John M. Barss Jan 1985

The Analysis And Use Of Methodologies For The Study Of The Diets Of Long-Eared Owls From Three Environments In North Central Oregon, John M. Barss

Dissertations and Theses

Part I of this study presents a procedure for standardization of pellet analysis methodologies which improves estimation of prey biomass and determines the number of pellets needed to estimate prey diversity indices. The procedure was developed to provide a simple, easily replicated methodology for the study of pellets which also retains maximal data recorded from pellet analysis. A sample size of ten Long-eared Owl pellets was found adequate to calculate diversity indices with no significant loss of accuracy when compared to total pellets recovered from beneath a roosting site. Analysis of the total sample of pellets from a specific roost …


A Phylokaryotypic Evaluation Of The Genus Tursiops (Family Delphinidae), Melissa Kay Estes Jan 1985

A Phylokaryotypic Evaluation Of The Genus Tursiops (Family Delphinidae), Melissa Kay Estes

Dissertations and Theses

In an attempt to correlate genetic data with possible species delineation, this study investigates the presence of chromosomal variants between the North Atlantic bottle nose dolphin, Tursiops truncatus, and the North Pacific bottle nose dolphin, T. gilli. Blood samples were obtained from oceanaria in the United States. Location of capture was correlated with karyotype to compare chromosome morphology with geographic range.


The Significance Of Hypovolemia In Dehydrational Death In Anurans, Peter Blair Kimmel Jan 1985

The Significance Of Hypovolemia In Dehydrational Death In Anurans, Peter Blair Kimmel

Dissertations and Theses

The importance of hypovolemia in dehydrational death was assessed in two anuran species. Xenopus laeyis, a species which experiences a significant reduction in circulating plasma volume with dehydration, was used to evaluate the role of sympathetic reflex compensation in hypovolemia. Adrenergic blockade with propranolol or phenoxybenzamine produced no significant reduction in dehydration tolerance in this species, although β-blockade with propranolol appeared to have a minor effect. The role of hypovolemic shock in the terminal circulatory collapse that precedes death in dehydrating anurans was investigated in the toad, Bufo marinus. The activity of lysosomal proteinases (cathepsins) was used as an indicator …


The Role Of Copper In The Apparent Aluminum Toxicity Of Aquatic Systems, Kirk Thomas O'Reilly Jan 1985

The Role Of Copper In The Apparent Aluminum Toxicity Of Aquatic Systems, Kirk Thomas O'Reilly

Dissertations and Theses

The effect of variations in aluminum and copper concentrations on the growth rate and enzyme activity of the green alga Scenedesmus quadricauda was investigated. The goal was to determine which chemical species control the biological parameters. The computer program MINEQL (Westal et al 1976) was used to estimate chemical speciation. In the prevalence of both metals, algal growth rate and alkaline phosphatase activity could be correlated to cupric ion activity. The activity of isolated bacterial alkaline phosphatase was found to be a function of both total copper concentration and cupric ion activity. A model was developed to predicted the effects …