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Brigham Young University

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Articles 331 - 348 of 348

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Effect Of Exercise On Tissue Concentrations Of Thyroid Hormones And On Thyroxine Degradation Rate In The Rat, William W. Winder Aug 1971

Effect Of Exercise On Tissue Concentrations Of Thyroid Hormones And On Thyroxine Degradation Rate In The Rat, William W. Winder

Theses and Dissertations

Several methods were used to detect changes in thyroid activity and in degradation of thyroxine (T4) in exercising and sedentary control rats. Rats were run in a motor-driven exercise wheel over a three-week period at progressively increasing work loads and then were run 1.5-2 hours per day for 10-14 days before sacrifice. Disappearance of injected T4-125I from plasma was considerably enhanced by exercise. As determined by isotopic equilibration and paper chromatographic methods, T4 concentration was depressed in plasma and elevated in liver of exercised rats. No significant changes in T4 concentration were observed in heart, kidney, or gastrocnemius muscle. Thyroidal …

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The Biochemical Response Of Provo Bay To Nutrient Inflow, R. Bruce Sundrud Aug 1971

The Biochemical Response Of Provo Bay To Nutrient Inflow, R. Bruce Sundrud

Theses and Dissertations

Provo Bay of Utah Lake, Utah, receives the effluents from farms, industry, and three cities. In order to determine the effects of these effluents, eleven stations were established throughout the Bay. At weekly intervals from June 19 to October 26, 1970, and monthly thereafter until March, 1971, the water at these stations was sampled for dissolved oxygen (DO}, carbon dioxide (CO2), turbidity, pH, phosphates, nitrates, biochemical oxygen demand (BOD) and coliform bacteria. Due to intense algal blooms, the quality of the water changes as it passes through Provo Bay. Average values for the inflow, mid-Bay, and point of discharge respectively …

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High-Pressure Phase Studies On Sodium–Potassium Alloys, D. Ray Anderson, J. Bevan Ott, Rex J. Goates, H. Tracy Hall Jan 1971

High-Pressure Phase Studies On Sodium–Potassium Alloys, D. Ray Anderson, J. Bevan Ott, Rex J. Goates, H. Tracy Hall

Faculty Publications

The solid–liquid phase diagrams were investigated to 60 kbar for elemental sodium, potassium, and various sodium–potassium alloys. The data for Na and K are in general agreement with those of earlier workers. In the alloy system the temperatures of both the peritectic and eutectic halts increase as the pressure increases, but with different slopes, so that the two invariant points merge at approximately 35 kbar. Above this pressure, two halts are again observed. One increases with increasing pressure, and the other decreases with increasing pressure up to 55 kbar, where it abruptly starts increasing again. Melting points for samples in …

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The Effects Of 2-Chloro-4-Ethylamino-6-Isopropylamino-S-Triazine (Atrazine) On The Activities Of Certain Calvin Cycle Enzymes In Barley And Corn, L. Chris Harrison Aug 1970

The Effects Of 2-Chloro-4-Ethylamino-6-Isopropylamino-S-Triazine (Atrazine) On The Activities Of Certain Calvin Cycle Enzymes In Barley And Corn, L. Chris Harrison

Theses and Dissertations

Atrazine (2-chloro-4, ethylamino-6-isopropylaminos- triazine) applied to Hordium vulgare L. variety barbless in low concentrations (0.001, 0.01, 0.1 uM) was shown to in--­ crease the activity of D-ribulose-1, 5-diphosphate carboxylase (RuDPCase) and phosphoribulokinase (PRuK) up to 23% and 30% respectively and increase the amount of chlorophyll and extractable protein up to 18% and 21% respectively over the control plants. These results indicate that sub-toxic levels of atrazine significantly stimulate plant growth. Barley plants given higher concentrations of atrazine (1.0 and 10 uM) showed up to a 78% and 42% decrease in the activity of RuDPCase and PRuK respectively as well as …

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Asymptotic Evaluation Of Wkb Matrix Elements. Ii. Use Of Langer's Uniform Asymptotic Wavefunctions, Wesley D. Smith, Russell T. Pack Feb 1970

Asymptotic Evaluation Of Wkb Matrix Elements. Ii. Use Of Langer's Uniform Asymptotic Wavefunctions, Wesley D. Smith, Russell T. Pack

Faculty Publications

An improvement in a previous procedure for the analytic asymptotic evaluation of integrals arising in the quantum-mechanical theory of inelastic molecular collisions is presented. The integrals are evaluated using Langer's uniform asymptotic wavefunctions and the higher-order saddle-point or steepest-descents method. It is found that the Langer functions give no better results than WKB functions, but the higher-order steepest-descents corrections produce a marked improvement. The result is a simple method for evaluating a large class of integrals with an error of 0.1%-2.1%.

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Quasilattice Interpretation Of The Thermodynamic Properties Of Mixing Of Binary Alkali-Metal Systems, J. Bevan Ott, J. Rex Goates Nov 1969

Quasilattice Interpretation Of The Thermodynamic Properties Of Mixing Of Binary Alkali-Metal Systems, J. Bevan Ott, J. Rex Goates

Faculty Publications

Quasilattice theory was applied to heats of mixing in the six systems formed from the binary combinations of Na, K, Rb, and Cs. The alkali-metal systems are particularly well suited for a critical test of the quasi-crystalline assumption since the theoretical model for these systems is relatively simple and the thermodynamic data are fairly complex. Very good fits of the heat-of-mixing data were achieved by assuming that the larger atom in the binary system covered multiple sites on the quasilattice. The values of the empirically determined constants appear to fit the physical significance accorded to them by the quasilattice model. …

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A Study Of Folic Acid Dependent Reactions In Bovine Brain, Dillard Spencer Broderick Aug 1969

A Study Of Folic Acid Dependent Reactions In Bovine Brain, Dillard Spencer Broderick

Theses and Dissertations

The enzymatic interconversion of serine to glycine and N5, N10-methylene tetrahydrofolate to N5 -methyl tetrahydrofolate have been studied in a cell-free system derived from bovine brain. A partial purification of serine transhydroxymethylase and N5, N10 -methylene tetrahydrofolate reductase has been achieved by ammonium sulfate fractionation, protamine sulfate fraction, and by various column chromatography procedures. The two enzymes studied catalyze sequentially the reductive transfer of the hydroxymethyl group of serine to the N5 position of tetrahydrofolate forming N5 -methyl tetrahydrofolate. The products of these reactions were assayed by the incorporation of C14 from a one-carbon precursor i.e., L-beta-(C14)-serine, or N5 -methyl …

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Expectation Values Of Simple Correlated Helium-Atom Wavefunctions, Thomas P. Tsien, Russell T. Pack Nov 1968

Expectation Values Of Simple Correlated Helium-Atom Wavefunctions, Thomas P. Tsien, Russell T. Pack

Faculty Publications

In this Note we present the results of a calculation of the expectation values of a number of one- and two electron properties of the ground-state helium atom using two very simple correlated wavefunctions.

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The Role Of Thiamine Pyrophosphate In Regulating The Level Of Gamma-Aminobutyric Acid In The Central Nervous System, Bryant L. Adams Aug 1965

The Role Of Thiamine Pyrophosphate In Regulating The Level Of Gamma-Aminobutyric Acid In The Central Nervous System, Bryant L. Adams

Theses and Dissertations

The level of gamma-aminobutyric acid in the brains of white rats suffering from thiamine deficiency symptoms resulting from pyrithiamine or oxythiamine antagonism of thiamine or from thiamine deprivation was measured. The level of this amino acid was 17.5% lower in the brains of pyrithiamine-treated rats and 20.0% lower in the brains of thiamine-deprived rats than in the control rats. Daily injections of ten times the required amounts of vitamin B6 in rats treated with pyrithiamine or oxythiamine or by thiamine deprivation had no effect on the level of brain gamma-aminobutyric acid or on the psiological behavior of these rats. The …

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Studies Of Rat Brain Thiamine Pyrophosphokinase, Lavell Rolfson Johnson Aug 1965

Studies Of Rat Brain Thiamine Pyrophosphokinase, Lavell Rolfson Johnson

Theses and Dissertations

The enzyme ATP:thiamine pyrophosphotransferase (thiamine pyrophosphokinaseJ was purified from acetone powders which were prepared from rat brains up to the chromatography on alumina C_γ step by a modified procedure that Mano (Y. Mano, J. Biochem., 42, 283 (1960)] developed for the purification of the rat liver thiamine pyrophosphokinase. The enzyme was purified 12 fold over that in the original extract of the acetone powder. A spectrophotometric assay for the brain thiamine pyrophosphokinase was developed utilizing brewer's yeast apotransketolase. The transketolase assay was able to detect less than 10^-11 moles of thiamine diphosphate, which was synthesized by the kinase, in the …

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The Vitamin B1-Sparing Action Of Sorbitol, Gisela Eleanor Bethsold Jun 1960

The Vitamin B1-Sparing Action Of Sorbitol, Gisela Eleanor Bethsold

Theses and Dissertations

The present study was initiated to determine the effect sorbitol has upon the enzymatic functions of thiamin; specifically, what effect sorbitol bas upon the alpha-ketoglutarate and pyruvate dehydrogenases activities of rat liver mitochondria. In addition, the effect of varying the dietary sorbitol concentration on the development of an athiaminosis was studied, particularly the effect on growth rate.

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Studies On The Biological Oxidation Of Ferrous Iron And Chalcopyrite, Loral Alvin Decker Aug 1959

Studies On The Biological Oxidation Of Ferrous Iron And Chalcopyrite, Loral Alvin Decker

Theses and Dissertations

The purpose of this investigation was to determine the effectiveness of the leaching streams from waste copper ore dumps as a nutrient solution for subsequent biological oxidation and solubilization of sulfide minerals. The copper in the leaching streams is precipitated by displacement with iron. As a result of this procedure the solution is high in ferrous iron concentration and has a pH of near 3.7. The bacteria in the leaching streams are capable of oxidizing ferrous iron to the ferric state and sulfide minerals to sulfates. The effects of temperatures, pH, urea, and aeration rate on the oxidation of the …

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A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson Apr 1958

A Study Of Three Photochemical Activities Of Chloroplasts, Jimmy W. Hinkson

Theses and Dissertations

Chloroplasts of sugar beet leaves were subjected to treatment by heating, by incubation at pH 8.5 and pH 5.5, by incubation in ion low water, by sonic oscillation, by digestion with enzymes (lysozyme, pancreatin, and lipase), by extraction with digitonin, and by chemical compounds including 8-hydroxy-quinoline, sodium azide, zinc sulfate, phenyl mercuric acetate, potassium cyanide, 1-allylthiourea, 2,4-dinitrophenol, thymol, and p-chloromercuribenzoate. A comparative study was made of the effects of these treatments upon three photochemical reactions (the photoreduction of 2,6- dichlorophenol indophenol, the photoreduction of indigo carmine in the presence of a couple composed of 2,6-dichlorophenol indophenol and ascorbic acid, and …

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Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson Jul 1957

Chemosynthetic Microorganisms In Leaching Sulfide Minerals, A. Keith Jameson

Theses and Dissertations

This investigation showed that a single bacterium was capable of sulfide oxidation in exposed ore bodies. This single bacterium was isolated and characterized. It exhibited different characteristics than any previously known organism. It was found to be a chemosynthetic autotroph. An optimum nutrient concentration was determined for pyrite oxidation. The nutrient concentration was determined for pyrite oxidation. The nutrient contains only a source of phosphate and nitrogen. Urea was found to be a better source of nitrogen than ammonium sulfate which had previously been used. The effect of various organic compounds on the oxidation of pyrite was observed. Glucose and …

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Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson Aug 1956

Oxidation Of Molybdenite With The Aid Of Microorganisms, Ralph Anderson

Theses and Dissertations

This work represents a study on the biological oxidation of molybdenite, MoS2. The principal objective of this study was to investigate the possibility of the biological oxidation of molybdenite, to determine the physical and chemical conditions under which the oxidative process occurs, and to develop a strain of bacteria or alter the activity of the microorganisms by acclimatization to increase their activity on sulfide minerals, in particular molybdenite. Minerals used in this study were pyrite (FeS2), chalcopyrite (CuFeS2), molybdenite concentrate, and molybdenite ore. The microorganisms used in this investigation were autotrophic bacteria obtained from the leaching streams of Bingham Canyon, …

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Photo-Oxidations Sensitized By Physiologically Important Substances, Ernel D. Ihnen Jun 1956

Photo-Oxidations Sensitized By Physiologically Important Substances, Ernel D. Ihnen

Theses and Dissertations

A study of the photo-oxidation of the 2,6-dichlorophenol indophenol-ascorbic couple was undertaken with a view to investigating the postulated mechanism of oxidation by a component of the oxygen evolving sequence operative in photosynthesis. A spectrophotometric method for the measurement of the progress of photo-oxidation was developed. Temperature and pH dependence were determined and the effect of various common inhibitors and physiological substances tested. None of the common Hill reaction inhibitors were effective in the ascorbic acid photo-oxidation in the system used. KCN and catalase as well as a few other high molecular weight proteins were able to inhibit dark auto-oxidation …

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The Chromatographic Purification Of Human Red Blood Cell Acetylcholinesterase, Richard P. Dunkley May 1954

The Chromatographic Purification Of Human Red Blood Cell Acetylcholinesterase, Richard P. Dunkley

Theses and Dissertations

A process of column chromatography of human erythrocyte acetylcholinesterase, using a cationic exchange resin, was investigated as a possible method for the primary partial purification of the enzyme on a large scale. The investigation was based, first; on a detailed study of the enzymatic stability to variation in hydrogen-ion and salt concentrations for periods of time extending to forty eight hours and, second; on an investigation of the degree of adsorption by the resin of the enzyme at various pH values within the pH range of enzyme stability. A method for the analysis of the enzyme activity of large numbers …

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Biological Oxidation Of Copper Sulfide Minerals, Delmar Boyd Davis Dec 1953

Biological Oxidation Of Copper Sulfide Minerals, Delmar Boyd Davis

Theses and Dissertations

This work represents a study of the biological oxidation of copper sulfide minerals. The principal objective of the study was to determine the extent of bacterial oxidation on copper containing sulfide minerals. It was also desired to determine if the bacteria could oxidize copper sulfides in the absence of iron. A better understanding of the nitrogen requirements of the organisms was desired. Minerals used in this study were Bingham Canyon Float Concentrate, chalcopyrite, covellite, calcocite, bornite, tetrahedrite, and reagent grade copper sulfide. The bacteria used were obtained from the mine waters of Bingham Canyon, Utah. To study the problem the …

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