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There is a conjecture that complete Riemannian 3-manifold with bounded sectional curvature, and pointwise pinched nonnegative Ricci must be flat or compact. We show this true when the negative part (if any) of curvature decays quadratically.

The interconversion and extraction of testosterone and androstenedione across and within different tissues or areas have been studied by the constant infusion technique. The results were calculated using the (3)H/(14)C ratios and radioactive concentrations of testosterone and androstenedione obtained from afferent and efferent blood and tissues at equilibrium. In each tissue studied, the interc...

The effects of &adrenergic agonists (e.g. epinephrine and isoproterenol) on the metabolic flux through, and the activation state of the pyruvate dehydrogenase multienzyme complex, were investigated in the isolated perfused rat heart. Infusion of epinephrine caused an inhibition of pyruvate decarboxylation at low (0.1 m ~ ) pyruvate concentrations in the perfusion medium, a stimulation of flux a...

Acholeplasma laidlawii B-PG9 was examined for 16 cytoplasmic enzymes with activity for purine salvage and interconversion. Phosphoribosyltransferase activities for adenine, guanine, xanthine, and hypoxanthine were shown. Adenine, guanine, xanthine, and hypoxanthine were ribosylated to their nucleoside. Adenosine, inosine, xanthosine, and guanosine were converted to their base. No ATP-dependent ...

when one of the substrates used is labeled, is readily demonstrable in both these tissues, even under aerobic conditions. The rate of interconversion in the actively respiring kidney slices was at least as high as the oxidative decarboxylation of the substrates. It proceeded more rapidly in the tumor cells in which its rate was 4-5 times as high as that of the oxidative decarboxyla tion. The fa...