7 research outputs found

    looming

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    loomAn unusual lapse rate of temperature (and therefore density as well) with height immediately above the sea (or land) surface produces a dis- tortion in the appearance of objects near the horizon; such a phenomenon is known as mirage. [enter symbol] When the surface is relatively cold (and the wind ver y light) so that the density of the air decreases rapidly for a short distance above the surface, light rays from objects low down near the horizon are bent down, the same way in fact as are usually the rays of the sun when entering the earth's atmosphere at a low altititude. The effect is to render visible objects that are normally below the horizon, e.g. lights may be 'raised' at night to much greater distances than one would ordinarily expect. This phenomenon is known as 'looming.'PRINTED ITEMNot usedNot usedWithdrawnChecked by Jordyn Hughes on Wed 17 May 201

    Alanine-Metabolizing Enzyme Alt1 Is Critical in Determining Yeast Life Span, As Revealed by Combined Metabolomic and Genetic Studies

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    Alterations in metabolic pathways are gaining attention as important environmental factors affecting life span, but the determination of specific metabolic pathways and enzymes involved in life span remains largely unexplored. By applying an NMR-based metabolomics approach to a calorie-restricted yeast (<i>Saccharomyces cerevisiae</i>) model, we found that alanine level is inversely correlated with yeast chronological life span. The involvement of the alanine-metabolizing pathway in the life span was tested using a deletion mutant of <i>ALT1</i>, the gene for a key alanine-metabolizing enzyme. The mutant exhibited increased endogenous alanine level and much shorter life span, demonstrating the importance of <i>ALT1</i> and alanine metabolic pathways in the life span. <i>ALT1</i>’s effect on life span was independent of the TOR pathway, as revealed by a <i>tor1</i> deletion mutant. Further mechanistic studies showed that <i>alt1</i> deletion suppresses cytochrome <i>c</i> oxidase subunit 2 expression, ultimately generating reactive oxygen species. Overall, <i>ALT1</i> seems critical in determining yeast life span, and our approach should be useful for the mechanistic studies of life span determinations

    Alanine-Metabolizing Enzyme Alt1 Is Critical in Determining Yeast Life Span, As Revealed by Combined Metabolomic and Genetic Studies

    No full text
    Alterations in metabolic pathways are gaining attention as important environmental factors affecting life span, but the determination of specific metabolic pathways and enzymes involved in life span remains largely unexplored. By applying an NMR-based metabolomics approach to a calorie-restricted yeast (<i>Saccharomyces cerevisiae</i>) model, we found that alanine level is inversely correlated with yeast chronological life span. The involvement of the alanine-metabolizing pathway in the life span was tested using a deletion mutant of <i>ALT1</i>, the gene for a key alanine-metabolizing enzyme. The mutant exhibited increased endogenous alanine level and much shorter life span, demonstrating the importance of <i>ALT1</i> and alanine metabolic pathways in the life span. <i>ALT1</i>’s effect on life span was independent of the TOR pathway, as revealed by a <i>tor1</i> deletion mutant. Further mechanistic studies showed that <i>alt1</i> deletion suppresses cytochrome <i>c</i> oxidase subunit 2 expression, ultimately generating reactive oxygen species. Overall, <i>ALT1</i> seems critical in determining yeast life span, and our approach should be useful for the mechanistic studies of life span determinations
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