Tight estimates

Insulin is the principal regulatory hormone involved in the tight regulation of fuel metabolism. In response to blood glucose levels, it is secreted by the b cells of the pancreas and exerts its effects by binding to cell surface receptors that are present on virtually all cell types and tissues. In humans, perturbations in insulin function and/or secretion lead to diabetes mellitus, a severe disorder primarily characterized by an inability to maintain blood glucose homeostasis. Furthermore, it is estimated that 90–95% of diabetic patients exhibit resistance to insulin action....

10p research12 01-06-2013 35 4   Download

Tightly coupled inside-out vesicles were prepared from Paracoccus denitrificanscells (SPP, sub-Paracoccusparticles) and characterized kinetically. The rate of NADHoxidation, catalysed by SPP, increases 6–8 times on addition of gram-icidin. The vesicles are capable of catalysing DlH + -dependent reverse electron transfer fromquinol toNAD + . The kinetic parameters of the NADH-oxidase and the reverse electron transfer carried out by membrane-bound P. denitrificanscomplex I were estimated and compared with those of the mitochondrial enzyme. ...

5p research12 23-04-2013 43 3   Download

It is shown that if a d-regular graph contains s vertices so that the distance between any pair is at least 4k, then its adjacency matrix has at least s eigenvalues which are at least 2pd − 1 cos(  2k ). A similar result has been proved by Friedman using more sophisticated tools.More generally, Serre has shown (see [3], [4] ) that for any fixed r and for any infinite family of d-regular graphs Gi, lim inf r(Gi) 2pd − 1. The same result has been proved by Friedman already in [5].

4p thulanh5 12-09-2011 97 6   Download