In [1], Samoilov, Plyasunov, and Arkin provide an example of a chemical reaction whose full stochastic (Master Equation) model exhibits bistable behavior, but for which the deterministic (mean field) version has a unique steady state. The reaction that they provide consists of an enzymatic futile mechanism driven by a second reaction which induces " deterministic noise " on the concentration of...

Siderophores of six fungi viz. Aspergillus sp. ABp4, Aureobacidium pullulans, Penicillium oxalicum, P. chrysosporium, Mycotypha africana and Syncephalastrum racemosum were examined for their (1) electrophoretic mobilities to determine the acidic, basic or neutral charge; (2) Fe (III) binding nature viz., mono-, di-, or trihydroxamate; (3) amino acid composition; and (4) NMR (nuclear magnetic re...

Clusters of noble metals, particularly gold, with precise nuclearity (number of atoms) and overall molecular composition continue to be a topic of intense experimental and theoretical research endeavors. These efforts aim at understanding the basic factors, such as electronic structure, atomic packing, and adsorbed layers that underlie the appearance of certain structural motifs and control the...

In this paper we consider the representation and generation of three-dimensional structures by means of formal descriptive methods. Graph and graph grammar theory present us with a powerful two-dimensional representational method, and we propose to use these concepts as basis for the threedimensional case. Three-dimensional structures however, often appear in other structures and within a certa...

The existence of certain structures designated as agglutinogens on the red cell envelope has been inferred from the reactions, hemolysis and agglutination, which occur on contact with specific antisera. These structures, whose chemical nature is incompletely understood, are antigenic, that is, they have the capacity to stimulate the formation of immune antibodies, and the reacting substances or...

Nonempirical quantum chemical ST0-3G calculations were performed for cluster models of two oxygen-bridged T0 4 tetrahedra (T = Si, Al). The models are based on [(H0)3T0T(0H)3]"structures and, in case of Al-containing models (n = 1,2), their electric neutrality is ensured by adding positive point charges. The calculations suggest the occurrence of X4.I — O —Al^ pairings provided certain electric...

It is shown that the Hermitian-symmetric space CP1 × CP1 × CP1 and the flag manifold F1,2 endowed with any left invariant metric admit no compatible integrable almost complex structures (even locally) different from the invariant ones. As an application it is proved that any stable harmonic immersion from F1,2 equipped with an invariant metric into an irreducible Hermitian symmetric space of co...

ALTHOUGH for many years it has been recognized that relationships exist between the chemical structures of certain compounds and their pharmacological properties, those interdependencies1 which have been observed have served more to correlate existing data in many isolated sectors of the field of drug action than to serve as guideposts on the road of medicine and research ahead. Therefore it ha...