Endothelin is a potent vasoconstrictor peptide which has recently been localized in the gastrointestinal tract. We have investigated the transmembrane signaling properties of endothelin in isolated smooth muscle cells of the rabbit rectosigmoid. Endothelin induced a dose dependent contraction of smooth muscle cells in a range of 10(-10) to 10(-6)M. In normal buffer, contraction peaked at 30 sec...

In this paper‎, ‎we introduce a new type of graph contraction using a special class of functions and give a best proximity point theorem for this contraction in complete metric spaces endowed with a graph under two different conditions‎. ‎We then support our main theorem by a non-trivial example and give some consequences of best proximity point of it for usual graphs.

We develop two generalizations of contraction theory, namely, semi-contraction and weak-contraction theory. First, using the notion seminorm, we propose a geometric framework for introduce matrix semimeasures characterize their properties. show that spectral abscissa is infimum over weighted semimeasures. For dynamical systems, use semimeasure Jacobian to contractivity properties trajectories. ...

In this paper, we introduce the (G-$psi$) contraction in a metric space by using a graph. Let $F,T$ be two multivalued mappings on $X.$ Among other things, we obtain a common fixed point of the mappings $F,T$ in the metric space $X$ endowed with a graph $G.$