The molecular mechanisms that regulate integrin-ligand binding are unknown; however, bivalent cations are essential for integrin activity. According to recent models of integrin tertiary structure, sites involved in ligand recognition are located on the upper face of the seven-bladed beta-propeller formed by the N-terminal repeats of the alpha subunit and on the von Willebrand factor A-domain-l...

The speci cation language Attempto Controlled English (ACE) is a controlled natural language, i.e. a subset of standard English with a domain-speci c vocabulary and a restricted grammar. The restriction of full natural language to a controlled subset is essential for ACE to be suitable for speci cation purposes. The main goals of this restriction are to reduce ambiguity and vagueness inherent i...

Compiler support for intervals as intrinsic data types is essential for promoting the development and wide-spread use of interval software. It also plays an important role in encouraging the development of hardware support for interval arithmetic. This paper describes modi cations made to the GNU Fortran Compiler to provide support for interval arithmetic. These modi cations are based on a rece...

The structure of margarosanite is probably very similar to that of synthetic CazBaSisOg. This in turn is closely related to other substances containing X3Oe rings: compare the cell dimensions given. These data show the existence of a series of metasilicates of large divalent cations containing X3Oe rings. These structures can also exhibit cation ordering; thus the Ca/Ba ratio is known to be fix...

Acidic deposition is comprised of sulfuric and nitric acids and ammonium derived from atmospheric emissions of sulfur dioxide, nitrogen oxides, and ammonia, respectively. Acidic deposition has altered soil through depletion of labile pools of nutrient cations (i.e. calcium, magnesium), accumulation of sulfur and nitrogen, and the mobilization of elevated concentrations of inorganic monomeric al...

Several natural and synthetic phospholipids can serve as substrates for the cyclopropane synthetase enzyme of Closfridium bufyricum. The conditions for optimum substrate effectiveness vary with the substrate; e.g. an anionic surfaceactive agent is necessary with phosphatidylethanolamine, while divalent cations stimulate the rate of reaction with anionic phospholipids. These variable conditions ...

The ODP Open Distributed Processing development model is a natural progression from OSI Multiple viewpoints are used to specify complex ODP systems The conformance assessment methodology for ODP de nes the relationships between speci cations and imple mentations that must be proved in order that conformance to ODP systems can be asserted These relationships include transformation re nement conf...

Accumulation of Li+ in Saccharomyces cerevisiae X2180-1B occurred via an apparent stoichiometric relationship of 1:1 (K+/Li+) when S. cerevisiae was incubated in the presence of 5 and 10 mM LiCl for 3 h. Other cellular cations (Mg2+, Ca2+ and Na+) did not vary on Li+ accumulation, although lithium chemistry dictates a degree of similarity to Group I and II metal cations. Compartmentation of Li+...

The kinetic properties of purified yeast pyruvate kinase were investigated. The enzyme showed cooperative kinetics toward the essential activating monovalent cations K+ and NH4+, Mg2+, and phosphoenolpyruvate. Fructose 1,6diphosphate, which yielded homotropic cooperative kinetics and did not affect maximal velocity, transformed the sigmoidal kinetics of Kf and NH4+, Mgz+, and phosphoenolpyruvat...