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Articles 13531 - 13560 of 13692

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

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation Jan 1971

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system. The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …


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 …


A Comparison Of Luteinizing Hormone And Prostaglandin F2 Α Stimulation Of Pseudo-Pregnant Rat Ovarian Steroidogenesis In Vitro, Ross R. Erickson Dec 1970

A Comparison Of Luteinizing Hormone And Prostaglandin F2 Α Stimulation Of Pseudo-Pregnant Rat Ovarian Steroidogenesis In Vitro, Ross R. Erickson

Masters Theses

No abstract provided.


Purification And Properties Of Dna Polymerase From Bacillus Licheniformis And Bacillus Stearothermophilus, Bruce A. Roe Dec 1970

Purification And Properties Of Dna Polymerase From Bacillus Licheniformis And Bacillus Stearothermophilus, Bruce A. Roe

Dissertations

No abstract provided.


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 …


The Enzymatic Oxidation Of Aldehydes By Xanthine Oxidase, Duane Beal Gregory Jun 1970

The Enzymatic Oxidation Of Aldehydes By Xanthine Oxidase, Duane Beal Gregory

All Master's Theses

As early as sixty years ago, the existence of an enzyme from mammalian tissues which catalyzed the oxidation of xanthine and hypoxanthine was recognized. The name given the enzyme was derived from its earliest recognized action, hence xanthine oxidase. Although little is known about the biological functions of the enzyme, the high affinity shown for xanthine and hypoxanthine may indicate that these are the most significant substrates biologically.


The Effects Of Sources And Levels Of Vitamin A And D On Some Aspects Of Sulfur Metabolism, Akbar Malekpour May 1970

The Effects Of Sources And Levels Of Vitamin A And D On Some Aspects Of Sulfur Metabolism, Akbar Malekpour

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Two trials were conducted using 48 infant pigs of both sexes. Pigs were taken from the sow when three to seven days old and placed in wire-bottomed metal cages by pairs. Animals in the first trial received synthetic diets containing 100 or 1000 international units of ergocalciferol and 1000 or 4000 international units of retinyl acetate or four or sixteen milligrams of beta carotene per kilogram of feed. Baby pigs in the second trial received the same synthetic diet plus 1000 international units of ergocalciferol (D2) or cholecalciferol (D3) and 2000 international units of vitamin A …


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%.


Compartmentation Of Glutamate Metabolism Observed With Glucose / D. D. Clarke, E. Dicker & E.J. Ronan, Chem. Dept. Fordham University, Bronx, N.Y. 10458, U.S.A., Donald Dudley Clarke Phd, E. Dicker, E. J. Ronan Jan 1970

Compartmentation Of Glutamate Metabolism Observed With Glucose / D. D. Clarke, E. Dicker & E.J. Ronan, Chem. Dept. Fordham University, Bronx, N.Y. 10458, U.S.A., Donald Dudley Clarke Phd, E. Dicker, E. J. Ronan

Chemistry Faculty Publications

Compartmentation of glutamate metabolism in the central nervous system has been demonstrated in a number of laboratories using a variety of labeled precursors. The labeling of glutamine is much more rapid than would be expected if the total pool of glutamate in brain is the precursor of glutamine. An obvious suggestion for the origin of this compartmentation is that it reflects glial vs. neuronal relationships. Some evidence in support of this idea has been obtained by Rose using separated neuronal vs. neuropil preparations (J. Neurochem. 17, 809 (1970)). Until recently orain was the only tissue which, after the injection of …


Urea Block Supplements For Stubble, H E. Fels, R. J. Parkin Jan 1970

Urea Block Supplements For Stubble, H E. Fels, R. J. Parkin

Journal of the Department of Agriculture, Western Australia, Series 4

THERE was a great deal of controversy throughout the summer of Western Australia's 1969-70 drought over the feeding of supplements other than grain to grazing sheep.

This report summarises some of the experiments carried out by this Department to investigate various artificial means of supplementing sheep grazing stubbles and dry summer pastures.

Further details of the experiments can be obtained by contacting the authors.

The results failed to demonstrate economic responses to urea supplements for grazing sheep.


Urea Or Grain Supplements For Stubble?, H E. Fels Jan 1970

Urea Or Grain Supplements For Stubble?, H E. Fels

Journal of the Department of Agriculture, Western Australia, Series 4

Three methods of supplementing sheep grazing stubble were compared at Merredin Research Station in 1970. The stubble used in the experiment was left after harvesting a nine-bushel crop of Gamenya wheat which was a weed-free second crop on new land. The land had never been sown to legumes.


Experiments With Urea On Private Farms, R J. Parkin, G. Palmer, A. Haagensen, L. D. White, R. J. Suiter, H. E. Fels Jan 1970

Experiments With Urea On Private Farms, R J. Parkin, G. Palmer, A. Haagensen, L. D. White, R. J. Suiter, H. E. Fels

Journal of the Department of Agriculture, Western Australia, Series 4

Many District Advisers have carried out trials on private farms to test the response to a variety of types of supplementary feeds. This report gives brief details of five such experiments carried out with urea supplements over the last five years. Table 1 summarises the details and results of these trials.


Urea Mixture Formulations, H E. Fels Jan 1970

Urea Mixture Formulations, H E. Fels

Journal of the Department of Agriculture, Western Australia, Series 4

This experiment was done once the experiment above (Urea or Grain Supplements for Stubble) had shown definite but uneconomic responses to a particular mixture of urea, molasses and minerals. The aim was to find whether the response depended on the content of various portions of the mixture, and whether the response to the "shotgun" lick could be explained by the presence of salt, sulphate or cobalt.


Evaluation Of The Essentiality Of Dextran In The Dental Caries Process, William Redman Grigsby Jan 1970

Evaluation Of The Essentiality Of Dextran In The Dental Caries Process, William Redman Grigsby

Theses and Dissertations

In summary, the main points to support the view that dextran synthesis is unessential to the dental caries process are presented below:

1 . Dextran-fed, microbe-bearing rats do not experience dental caries.

2 . Lactobacillus casei 4646 has no extracellular dextransucrase enzyme or other extracellular enzymes which release glucose or fructose from sucrose .

3. L. casei 4646 does not synthesize extracellular polysaccharide of the dextran class when grown on sucrose-containing medium.

4. L. casei 4646 does not exhibit in vitro, adherent growth on stainless-steel wire when grown on sucrose-containing medium .

5. L. casei 4646 does not cause dental …


Characterization Of Some Unidentified Components In Aorta Lipids, Max Elvin Royer Nov 1969

Characterization Of Some Unidentified Components In Aorta Lipids, Max Elvin Royer

Masters Theses

No abstract provided.


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. …


Pigments And Neurogenic Secretions Of Dermasterias Imbricata, Stephen Edward Davis Aug 1969

Pigments And Neurogenic Secretions Of Dermasterias Imbricata, Stephen Edward Davis

All Master's Theses

Identification of the compound from the asteroid Dermasterias imbricata that evokes the swimming response in the sea anemone Stomphia coccinea was attempted. Although the compound was not identified, it was postulated to be a low molecular weight highly polar molecule of possible carbohydrate origin.


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 …


Gas Chromatographic Determination Of Changes In Concentration Of Pipecolic Acid And Other Free Amino Acids In Hypersensitive Tobacco Plants Induced By Tobacco Mosaic Virus And Temperature, David Francis Brown May 1969

Gas Chromatographic Determination Of Changes In Concentration Of Pipecolic Acid And Other Free Amino Acids In Hypersensitive Tobacco Plants Induced By Tobacco Mosaic Virus And Temperature, David Francis Brown

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes in concentrations of pipecolic acid and other free amino acids in Nicotiana tabacum, L. cv. Xanthi induced by tobacco mosaic virus (TMV) incubated at 75 or 95 F after inoculation were investigated gas chromatographically. A preliminary extraction and gas chromatographic technique for separation and quantitative determination of the free amino acids, using hydroxyproline as an internal standard, was developed.

Amino acids were converted into their trifluoroacetyl n-butyl (TAB) derivatives and gas chromatographed on 0.325 percent ethylene glycol adipate (EGA) columns. Resolution was generally good, but glycine-isoleucine and phenylalanine-aspartic acids were not resolved on old columns. The over-all …


Quantitative Evaluation Of Saponin Content In Du Puits Alfalfa Foliage (Medicago Sativa L.) With Trichoderma, Wang Li-Chun May 1969

Quantitative Evaluation Of Saponin Content In Du Puits Alfalfa Foliage (Medicago Sativa L.) With Trichoderma, Wang Li-Chun

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Selections in Du Puits alfalfa (Medicago sativa L. ) were evaluated for saponin content. The data obtained from the Trichoderma bioassay were converted to saponin values by regressions and standard curves. It was necessary to adjust the concentration of alfalfa extract in the bioassay so that the saponin content in alfalfa was estimated in that portion of the curve showing a marked response to saponin. A different regression was established for each group of low and high saponin plants of Du Puits alfalfa. The standard curve prepared with extract of Du Puits alfalfa used on the basis of its …


The Nature Of The "Contractile" Protein Isolated From Brain / S. Puszkin, E. Puszkin, D. D. Clarke, And S. Berl. Coll Of Phys. And Surgeons., Columbia Univ., N.Y. 10032, S. Puszkin, E. Puszkin, Donald Dudley Clarke Phd, Soll Berl Jan 1969

The Nature Of The "Contractile" Protein Isolated From Brain / S. Puszkin, E. Puszkin, D. D. Clarke, And S. Berl. Coll Of Phys. And Surgeons., Columbia Univ., N.Y. 10032, S. Puszkin, E. Puszkin, Donald Dudley Clarke Phd, Soll Berl

Chemistry Faculty Publications

We have described the isolation from brain of a Mg++/Ca++-ATPase resembling muscle actomyosin (Sci. 12 1 1701 1968). Like myofibrils (Perry and Grey 1 Biochem. J. 64, 184, 1956), the ATPase activity isolated from rat and cat brain is dependent upon the cone. of ATP and cation. When the conc. of ATP exceeds that of Mg++ 1 enzyme activity is inhibited. With increasing conc. of Mg++ 1 the optimum conc. of ATP also increases. This does not occur with Ca++ . Polyethylenesulfonate( PS)(I0-6M)causes the splitting of actomyosin into actin and myosin; the Mg++-ATPose activity is correspondingly diminished (Barony and Joisle …


The Dissociative Breakdown Of Negative Ions / By D. D. Clarke, Chemistry Department, Fordham University, New York, 10458, U.S.A. C. A. Coulson, Mathematical Institute, University Of Oxford, Donald Dudley Clarke Phd, C. A. Coulson Jan 1969

The Dissociative Breakdown Of Negative Ions / By D. D. Clarke, Chemistry Department, Fordham University, New York, 10458, U.S.A. C. A. Coulson, Mathematical Institute, University Of Oxford, Donald Dudley Clarke Phd, C. A. Coulson

Chemistry Faculty Publications

A discussion is given of the process whereby a substituted aromatic molecule captures a slow electron and dissociates. It is shown that the process often goes via two stages. and that the relative symmetries of the electroncapture state and the final dissociation state are very important. Both the sensitivity of the process to changes in the substituent and the existence of an activation energy are explained in the model


Decarboxylation Studies Of Glutamate, Glutamine, And Aspartate From Brain Labelled With [I-14]Acetate, L-[U-14c]-Aspartate, And L-[U-14c]Glutamate / W.J. Nickls And D. D. Clarke Chemistry Department, Fordham University, Bronx, N.Y. And S. Berl Department Of Neurology, College Of Physicians And Surgeons, Columbia University, New York, N.Y., William J. Nicklas, Donald Dudley Clarke Phd, Soll Berl Jan 1969

Decarboxylation Studies Of Glutamate, Glutamine, And Aspartate From Brain Labelled With [I-14]Acetate, L-[U-14c]-Aspartate, And L-[U-14c]Glutamate / W.J. Nickls And D. D. Clarke Chemistry Department, Fordham University, Bronx, N.Y. And S. Berl Department Of Neurology, College Of Physicians And Surgeons, Columbia University, New York, N.Y., William J. Nicklas, Donald Dudley Clarke Phd, Soll Berl

Chemistry Faculty Publications

Studies in vivo and in vitro of the distribution of label in C-1 of glutamate and glutamine and C-4 of aspartate in the free amino acids of brain were carried out. [1-14C]Acetate was used both in vivo and in vitro and L-[U-14C]aspartate and L-[U-14C]glutamate were used in vitro. (1) The results obtained with labelled acetate and aspartate suggest that CO2 and a 3-carbon acid may exchange at different rates on a CO2-fixing enzyme. (2) The apparent cycling times of both glutamate and glutamine show fast components measured in minutes and slow components measured in hours. (3) With [l-14C]acetate in vitro …


Nitrogen Fertiliser Survey, Department Of Agriculture, Western Australia Jan 1969

Nitrogen Fertiliser Survey, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

THE DECEMBER, 1968 issue of the "Journal of Agriculture" included, as part of an article on the economics of nitrogen fertiliser use, a lift-out section for farmers to complete and return to the Journal.

In the lift-out, farmers were asked to calculate their fertiliser costs and answer a series of questions about the use of nitrogen on their farms.


Metabolic Responses Of White Rats To Glucose Or Fructose Fed With Two Safflower Oils Containing Different Proportions Of Fatty Acid, Paula Lynn Yates Jan 1969

Metabolic Responses Of White Rats To Glucose Or Fructose Fed With Two Safflower Oils Containing Different Proportions Of Fatty Acid, Paula Lynn Yates

Journal of the Arkansas Academy of Science

No abstract provided.


Superphosphate For Wheatbelt Pastures : Rates Of Application, Walter Jacob Cox Jan 1969

Superphosphate For Wheatbelt Pastures : Rates Of Application, Walter Jacob Cox

Journal of the Department of Agriculture, Western Australia, Series 4

BECAUSE Western Australian soils are low in phosphorus, frequent applications of superphosphate are required for both crop and pasture production. The recommended rates are determined from the results of field experiments that test different quantities of super and measure the extra yield.

This article discusses the recommended rates of superphosphate in relation to soil type and superphosphate history. Methods of application and time of topdressing are also discussed.


Electrophoretic Patterns Of Plasma Proteins And Hemoglobin Of The Pigeon Columba Liva Domestica, Lloyd D. Snow, Earl L. Hanebrink, Bob D. Johnson Jan 1969

Electrophoretic Patterns Of Plasma Proteins And Hemoglobin Of The Pigeon Columba Liva Domestica, Lloyd D. Snow, Earl L. Hanebrink, Bob D. Johnson

Journal of the Arkansas Academy of Science

No abstract provided.


The Identification Of Cis-Ii, I2-Methylene-2-Hydroxyoctadecanoic Acid From Thiobacillus Thiooxidans, H. W. Knoche, J. M. Shively Jan 1969

The Identification Of Cis-Ii, I2-Methylene-2-Hydroxyoctadecanoic Acid From Thiobacillus Thiooxidans, H. W. Knoche, J. M. Shively

Department of Biochemistry: Faculty Publications

A polar fatty acid has been observed as a component of an

ornithine-containing lipid of Thiobacillus thiooxidans. A

comparison of thin layer chromatographic mobilities of reference

compounds to those of the natural acid and its derivatives

suggested that the acid was a 2-hydroxy fatty acid.

The presence of a cyclopropane function in the acid was

indicated by l4e-Iabeling experiments and infrared spectroscopy.

Mass spectrometry of the methyl ester and the acetylated

methyl ester of the natural acid provided a molecular

weight for the acid. Equivalent chain lengths were determined

for the natural acid, the acid obtained by oxidative

decarboxylation of …


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.


Membrane Bound Dehydrogenase Enzymes And Related Electron Transport Systems In Acetobacter Aceti Var. Liquefaciens: Their Induction And Pleiotropic Nature, John C. Rakoczy Oct 1968

Membrane Bound Dehydrogenase Enzymes And Related Electron Transport Systems In Acetobacter Aceti Var. Liquefaciens: Their Induction And Pleiotropic Nature, John C. Rakoczy

Masters Theses

No abstract provided.