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Frederick S. Brown

Articles 1 - 4 of 4

Full-Text Articles in Operations Research, Systems Engineering and Industrial Engineering

The Viking Biological Investigation: Preliminary Results, Harold Klein, Norman Horowitz, Gilbert Levin, Vance Oyama, Joshua Lederberg, Alexander Rich, Jerry Hubbard, George Lobby, Patricia Straat, Bonnie Berdahl, Glenn Carle, Frederick Brown, Richard Johnson Jun 2014

The Viking Biological Investigation: Preliminary Results, Harold Klein, Norman Horowitz, Gilbert Levin, Vance Oyama, Joshua Lederberg, Alexander Rich, Jerry Hubbard, George Lobby, Patricia Straat, Bonnie Berdahl, Glenn Carle, Frederick Brown, Richard Johnson

Frederick S. Brown

Three different types of biological experiments on samples of martian surface material ("soil") were conducted inside the Viking lander. In the carbon assimilation or pyrolytic release experiment, $^{14}$CO$_{2}$ and $^{14}$CO were exposed to soil in the presence of light. A small amount of gas was found to be converted into organic material. Heat treatment of a duplicate sample prevented such conversion. In the gas exchange experiment, soil was first humidified (exposed to water vapor) for 6 sols and then wet with a complex aqueous solution of metabolites. The gas above the soil was monitored by gas ...


Chloroperoxidase: Ii. Utilization Of Halogen Anions, Lowell Hagar, David Morris, Frederick Brown, Horst Eberwein Jun 2014

Chloroperoxidase: Ii. Utilization Of Halogen Anions, Lowell Hagar, David Morris, Frederick Brown, Horst Eberwein

Frederick S. Brown

Chloroperoxidase can utilize chloride, bromide, and iodide ions and catalyze the formation of a carbon-halogen bond in the presence of suitable acceptor molecules. Suitable halogen acceptor molecules are β-keto acids, cyclic β-diketones, and substituted phenols.

An optical assay has been developed to measure the halogenating activity of chloroperoxidase. The assay is based on the conversion of monochlorodimedon to the corresponding gem-dihalo derivative. The optical assay is based on the loss of absorbance at 278 mµ associated with the formation of the dihalo derivative from the monohalo compound.

In the optical assay, crystalline chloroperoxidase preparations catalyze the formation of the ...


Seed Meal Constituents, Oxazolidinethiones And Volatile Isothiocyanates In Enzyme-Treated Seed Meals From 65 Species Of Cruciferae, Frederick Brown, M. E Daxenbichler, C. H Vanetten, Q. Jones Jun 2014

Seed Meal Constituents, Oxazolidinethiones And Volatile Isothiocyanates In Enzyme-Treated Seed Meals From 65 Species Of Cruciferae, Frederick Brown, M. E Daxenbichler, C. H Vanetten, Q. Jones

Frederick S. Brown

Information is unavailable concerning the amounts and types of isothiocyanate-yielding glucosides in many species of Cruciferae seeds. Because such compounds have nutritional significance, a number of unreported species were investigated. Information about the parent thioglucosides was obtained by estimation of the oxazolidinethione and steam-volatile isothiocyanate contents of enzymatic hydrolyzates of the seed meals. Significant amounts of oxazolidinethione were found in hydrolyzates from 11 species not previously known to contain such glucosidic precursors. Oxazolidinethione (calculated as vinyl oxazolidinethione) measurements ranged from 0 to 19.3 mg. per gram of pentane- hexane-extracted meal. Total volatile isothiocyanate measurements (calculated as butenyl isothiocyanate) ranged ...


Racemization Of Amino Acids In Sediments From Saanich Inlet, British Columbia, Keith Kvenvolden, Etta Peterson, Frederick Brown Jun 2014

Racemization Of Amino Acids In Sediments From Saanich Inlet, British Columbia, Keith Kvenvolden, Etta Peterson, Frederick Brown

Frederick S. Brown

In sediments spanning the last 9000 years from Saanich Inlet L enantiomers of amino acids are most abundant, but the percentages of D enantiomers increase with age, apparently because of partial racemization. Of the amino acids measured, glutamic acid and alanine show the greatest degree of racemization; leucine, isoleucine, and valine show the least.