Higher-order duality for a class of nondifferentiable multiobjective programming problems involving generalized type I and related functions

This paper extends the class of generalized type I functions introduced by Aghezzaf and Hachimi(2000) to the context of higher-order case and formulate a number of higher-order duals to a non-differentiable multi-objective programming problem and establishes higher-order duality results under the higher-order generalized type I functions introduced in the present paper. A special case that appears repeatedly in the literature is that the support function is the square root of a positive semi-definite quadratic form. This and other special cases can be readily generated from these results.     

Satellite DNA (II) from sea urchin (Lytechinus variegatus) sperm

When DNA isolated from freshly collected sperm of sea urchin (Lytechinus variegatus) is centrifuged to equilibrium in CsCl, 2 heavy satellite bands appear beside the main band DNA. Satellite DNA (II) appears in between the main band DNA (rho = 1.695 g/cm3) and the rDNA satellite (rho = 1.722 g/cm3). Satellite DNA (II) has a buoyant density 1.710 g/cm3, corresponding to 50% GC content. It is speculated that the satellite DNA (II), which appears to be of high mol. wt, might contain the sequences complementary to histone mRNA.     

A conformationally isoformic thermophilic protein with high kinetic unfolding barriers

The basis for the stability of thermophilic proteins is of fundamental interest for extremophile biology. We investigated the folding and unfolding processes of the homotetrameric Thermoanaerobacter brockii alcohol dehydrogenase (TBADH). TBADH subunits were 4.8 kcal/mol less stable towards guanidinium chloride (GdmCl) unfolding compared to urea, indicating ionic modulation of TBADH stability. Strongly denaturing conditions promoted mono-exponential unfolding kinetics with linear dependence on denaturant concentration. Here TBADH unfolded >40-fold slower when extrapolated from urea as compared to GdmCl unfolding. A marked unfolding hysteresis was shown when comparing refolding and unfolding in urea. An unusual biphasic unfolding trajectory with an exceptionally slow phase at intermediate concentrations of GdmCl and urea was also observed. We advocate that TBADH forms two distinctly different tetrameric isoforms, and likely an ensemble of native states. This unusual supramolecular folding behavior has been shown responsible for formation of amyloidotic yeast prion strains and can have functional importance for TBADH. Received 9 November 2007; received after revision 19 December 2007; accepted 8 January 2008     

Extraction of Zr(IV) from hydrochloric acid with tri-octyl amine and Cyanex 921 in kerosene

This article reports the extraction of zirconium (IV) from aqueous HCl solution by tri-octyl amine (TOA), Cyanex 921, and their binary mixture using kerosene as the diluent. The effect of some parameters on the extraction of Zr(IV) was investigated such as equilibration time, aqueous phase acidity, extractant molarity, chloride ion concentration, nature of diluents, and temperature. The extraction of Zr(IV) was found to be 99% from 7.5 M HCl using the mixture of extractants containing 0.1 M TOA and 0.02 M Cyanex 921 in kerosene. Kerosene was found to be the effective diluent for the extraction of Zr(IV) with the binary mixture of TOA and Cyanex 921. The positive enthalpy change and positive entropy change in the binary extraction system show the endothermic process with an increase in entropy. Stripping of Zr(IV) from the loaded organic phase containing the mixture of TOA (0.1 M) and Cyanex 921 (0.02 M) indicates that HNO₃ and Na₂CO₃ are the best stripping agents.     

Optimal parallel algorithm for shortest paths problem on interval graphs

This paper presents an efficient parallel algorithm for the shortest-path problem in interval graph for computing shortest-paths in a weighted interval graph that runs in O(n) time with n intervals in a graph. A linear processor CRCW algorithm for determining the shortest-paths in an interval graphs is given.     

MINIMAX PROGRAMMING UNDER GENERALIZED （p, r）-INVEXITY

Minimax programming problems involving generalized （p, r）-invex functions are consid- ered. Parametric sufficient optimality conditions and duality results are established under the aforesaid assumptions on the objective and constraint functions.