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Byline: C. Lahariya, M. Goel, A. Kumar, M. Puri, A. Sodhi The emerging and re-emerging diseases are posing a great health risk for the last few years. One such category [...]

This review describes the nature and applications of ribosome inactivating proteins (RIPs) from Momordica charantia (bitter melon). RIPs from the plant kingdom have received much attention in biomedical research because they target conserved host protein synthesis machinery and show specificity towards human and animal cell targets. Recent studies aimed at unravelling the enzymatic activities of the M charantia RIPs provide a structural basis for their activities. It has been reported that RIPs are member of the single chain ribosome inactivating protein (SCRIP) family which act irreversibly on ribosome by removing adenine residue from eukaryotic ribosomal RNA. Various activities of RIPs include anti-tumor, broad anti-viral, ribonuclease and deoxyribonuclease. MAP30 (Momordica Anti-HIV Protein), - and -momorcharins inhibit HIV replication in acutely and chronically infected cells and thus are considered potential therapeutic agent in HIV infection and AIDS. Further, MAP30 improved the efficacy of anti-HIV therapy when used in combination with other anti-viral drugs. MAP30 holds therapeutic promise over other RIPs because not only it is active against infection and replication of both HSV and HIV but is non toxic to normal cells. Here we review the nature, action, structure function relationship and applications of RIPs from Momordica charantia and evaluate their potential for anticancer and anti-viral therapy.

AbstractThis article presents a solution technique to generate the exhaustive set of efficient solutions of a bicriteria integer quadratic programming problem. An integer quadratic programming problem with one of the objective functions as the principal objective is considered. By varying the minimum acceptable values of the second objective. a sequence of constrained single objective integer quadratic programming problems is solved by ranking the integer feasible solutions of a related integer linear programming problem. These solutions help in generating the complete set of efficient solutions. In ranking the integer feasible solutions we start with an optimal feasible solution of the related integer linear programming problem and we use post-optimality procedures to find the next best integer feasible solutions.

TEK (TIE2) and TIE (TIE1) are structurally related receptor tyrosine kinases expressed in endothelial cells and their precursors. Genetic studies in the mouse have revealed essential functions of both receptors in angiogenic expansion of the vasculature during development. As previously shown, mouse embryos homozygous for a disrupted Tek allele die by day 10.5 of embryogenesis due to endocardial defects, hemorrhaging, and impaired vascular network formation. Furthermore, TIE is required cell autonomously for endothelial cell survival and extension of the vascular network during late embryogenesis. Here we have investigated possible redundancy in the TEK and TIE signalling pathways during vascular development. Vasculogenesis proceeds normally in embryos lacking both TEK and TIE, although such embryos die early in gestation of multiple cardiovascular defects. Mosaic analysis revealed an absolute requirement for TEK in the endocardium at E10.5, whereas TEK and TIE are dispensable for the initial assembly of the rest of the vasculature. In contrast, both receptors are required in the microvasculature during late organogenesis and in essentially all blood vessels of the adult. This analysis demonstrates essential functions for TEK and TIE in maintaining the integrity of the mature vasculature.

Vibration isolators consisting of polymeric materials exhibit non-linearity in their stiffness and damping characteristics. Two different approaches towards modelling these non-linear characteristics are discussed. In one approach, experimentally obtained hysteresis loops are modelled through a suitable constitutive equation. In the other, experimentally obtained harmonic, displacement transmissibility plots are modelled by expressing the restoring and damping forces through lower order polynomials of deformation and rate of deformation, respectively. In both cases, it is observed that the dynamic stiffness, which is more than the static stiffness, exhibits a small softening type non-linearity. The non-linearity in the damping characteristic is seen to be more pronounced than that in the stiffness.

Vascular endothelial cells are critical for the development and function of the mammalian circulatory system. We have analyzed the role of the endothelial cell‐specific receptor tyrosine kinase TIE in the mouse vasculature. Mouse embryos homozygous for a disrupted Tie allele developed severe edema, their microvasculature was ruptured and they died between days 13.5 and 14.5 of gestation. The major blood vessels of the homozygous embryos appeared normal. Cells lacking a functional Tie gene were unable to contribute to the adult kidney endothelium in chimeric animals, further demonstrating the intrinsic requirement for TIE in endothelial cells. We conclude that TIE is required during embryonic development for the integrity and survival of vascular endothelial cells, particularly in the regions undergoing angiogenic growth of capillaries. TIE is not essential, however, for vasculogenesis, the early differentiation of endothelial cells.

An algorithm is developed which ranks the feasible solutions of an integer fractional programming problem in decreasing order of the objective function values.

In this paper the fixed charge problem viz: Minsubject toAX=b, X>-0is solved by systematically enumerating extreme points of a linear programming problem viz:subject toAX= b, xj−dj°j≤0, X≥0 °≥0 where ° is an extreme point ofIn°≤1. The technique provides an exact solution of the problem. The theory is supported by a numerical example.

The three dimensional bottleneck assignment problem and some of its variants are studied in the present paper. A procedure is developed for each of these bottleneck assignment problems.

Gamma radiation damage in zeolite- 13X is studied with special reference to the Cs+ uptake by the zeolite. Prolonged exposure to a 5 kCi 60Co-γ source with a dose rate of 4.5 k Gyh-1 does not alter the cation exchange capacity of the zeolite. Structural effects consequent to γ-irradiation are examined by the X-ray diffraction, i.r. and surface area measurements. The data support the view of displacement of exchangeable cations as also the framework atoms from their normal locations. EPR measurements suggest the formation of paramagnetic centre in the structure. A 3 % weight loss and release of hydrogen subsequent to γ-irradiation (∼840 h) is attributed to the radiolysis of zeolite water.

Radiation damage in zeolite-13X exposed to neutrons is studied with reference to its effect upon the Cs+ uptake capacity of the zeolite. Structural investigation is carried out by XRD, IR, ESR spectroscopy and thermal analysis. The observations indicate a slight expansion with minor changes in the Al, Si order of the zeolite framework upon prolonged n-exposure. A 2.8% loss in zeolite water is attributed to radiolysis via the n- and accompanying γ-interactions with water molecules. No significant change either in diffusivity or in net uptake of Cs + is observed.

The preferential exchange uptake of the cations Cs+, Ba2+ and Zn2+ from pure solutions by zeolite-13X follows the order Q∞ [Cs+]>Q∞ [Ba2+]>Q∞ [Zn2+], while in case of binary mixtures the order is Q∞ [Ba2+(Zn2+)]>Q∞ [Ba2+(Cs+)]>Q∞ [Cs+(Zn2+)]>Q∞ [Cs+(Ba2+)]>Q∞ [Zn2+(Cs+)]>Q∞ [Zn2+(Ba2+)]. Ba2+ uptake from mixtures shows the least suppression effect.

A new Aurivillius phase, (Bi2O2)(NaNb2O6.5), with intrinsic oxygen vacancies has been synthesized. The average structure is very close to that of the parent phase (Bi2O2)(CaNb2O7). The new phase displays a discontinuous change in the Arrhenius plot of the ionic conductivity versus temperature. Differential thermal analysis (DTA) confirmed the presence of a reversible phase transition at 860°C. At 900°C, the conductivity of (Bi2O2)(NaNb2O6.5) is 10−2S cm−1. At 1000°C, the Aurivillius phas e slowly decomposes to a mixture of phases with a lower total conductivity.

TIE is a receptor tyrosine kinase expressed in both mature endothelial cells and their precursors, as well as in some hematopoietic cells. Mouse embryos homozygous for a disrupted Tie allele die at midgestation due to impaired endothelial cell integrity and resulting hemorrhage. Here we have performed chimeric analysis to study further the function of the murine TIE in the development of embryonic vasculature and in the hematopoietic system. Cells lacking a functional Tie gene (tie(lcz)/tie(lczn-) cells) contributed to the embryonic vasculature at E10.5 as efficiently as cells heterozygous for a targeted Tie allele (tie(lcz)/+ cells). Thus, TIE does not play a significant role in vasculogenesis or in early angiogenic processes, such as formation of the intersomitic arteries and limb bud vascularization. At E15.5 tie(lcz)/tie(lczn-) cells still readily contributed to major blood vessels and to endothelial cells of organs such as lung and heart, which have been suggested to be vascularized by angioblast differentiation. In contrast, the tie(lcz)/tie(lczn-) cells were selected against in the capillary plexuses of several angiogenically vascularized tissues, such as brain and kidney. Our results thus support a role for TIE in late phases of angiogenesis but not vasculogenesis. Furthermore, the results suggest that different mechanisms regulate early and late angiogenesis and provide support for a model of differential organ vascularization by vasculogenic or angiogenic processes. Analysis of adult chimeras suggested that TIE is required to support the survival or proliferation of certain types of endothelial cells demonstrating heterogeneity in the growth/survival factor requirements in various endothelial cell populations. Chimeric analysis of adult hematopoietic cell populations, including peripheral platelets and bone marrow progenitor cells, revealed that tie(lcz)/tie(lczn-) cells were able to contribute to these cell types in a way indistinguishable from tie(lcz)/+ or wild-type cells. Thus, the primary function of TIE appears to be restricted to the endothelial cell lineage.

LetW(N,d)be theN-parameter Wiener process with values inRd. Then the dimension of the level sets isN−d/2 with positive probability ifd<2N. The dimension of the graph is a.s. min {2N,N+d/2}. The level sets have zero (N−d/2)-measure a.s. and the graph has zero min {2N,N+d/2}-measure a.s.

The paper discusses a non-concave fractional programming problem aiming at maximization of a pseudoconvex function under standard transportation conditions. The pseudoconvex function considered here is the product of two linear functions contrasted with a positive valued linear function. It has been established that optimal solution of the problem is attainable at an extreme point of the convex feasible region. The problem is shown to be related to ‘indefinite’ quadratic programming which deals with maximization of a convex function over the given feasible region. It has been further established that the local maximum point of this quadratic programming problem is the global maximum point under certain conditions, and its optimal solution provides an upper bound on the optimal value of the main problem. The extreme point solutions of the ‘indefinite’ quadratic program are ranked to tighten the bounds on the optimal value of the main problem and a convergent algorithm is developed to obtain the optimal solution. In der Arbeit betrachten wir ein Transportproblem mit nicht-konkaver, peudo-konvexer Zielfunktion, die sich als Quotient des Produktes zweier linearer Funktionen und einer linearen Funktion ergibt. Man kann zeigen, daß die Optimallösung für dieses Problem in einer Ecke des zulässigen Bereichs angenommen wird. Die betrachtete Problemstellung ist verwandt mit der Problemstellung der indefiniten quadratischen Optimierung. Für diese Probleme ist jedes lokale Optimum auch global optimal und die Optimallösung liefert zunächst eine obere Schranke für unser Ausgangsproblem. Durch ein „Ranking“ der Ecken des Quadratischen Programms erhalten wir dann die Optimallösung für das pseudo-konvexe Transportproblem.

In this paper, the conditions that govern the existence of the "more(same)-for-less" paradox in a minimal cost network flow problem with bounded variables are obtained. Some supporting illustrations are also included

This paper studies a special class of min max problems in two sections. In Section I, a procedure is developed which gives the optimal solution of the problem. The Section II deals with ranking the solutions in increasing order of the value of the objective function.

The bicriteria bottleneck linear programming problem is studied in this paper. The two criteria considered are concave bottleneck functions, and the feasible region is a non-empty convex polyhedron. It has been established that all the efficient pairs of values of the objective function can be attained at the extreme points of the feasible region. Based upon some related bottleneck linear programming problems and linear programming problems, a convergent algorithm to generate all the efficient pairs is proposed

The present paper studies a paradox in Linear Fractional Transportation Problems with 'mixed constraints'. A sufficient condition for the existence of a paradox is established. Paradoxical range of flow is obtained for any flow in which the corresponding objective function value is less than that of the original Linear Fractional Transportation Problem with 'mixed constraints'

The bilevel fractional programming problem (BFPP), in which the follower's objective function is a linear fractional functional, is introduced and studied in this paper. The leader's and the follower's decision variables are related by linear constraints. A solution strategy for (BFPP) when the leader's objective is a bottleneck function is presented. In this case the optimal solution is found to exist at an entreme point of the underlying region. However in the case when the leader's objective function is a linear function or a linear fractional function, the corresponding (BFPP) is found to be hard as its optimal solution may occur at a non-extreme point of the underlying region. This problem is posed as a potential area for further research.

Abstract: Competitive uptake of Cs+, Ba2+ and Zn2+ ions from aqueous medium by zeolite-3A is studied by the radiotracer technique. Suppression Cs+ uptake in presence of Ba2+ is the maximum amongst the competitive uptakes. The simultaneous uptakes of the individual cations are considered in the light of the zeolite pore size, hydration effects and mobilities of the competing cations.

This paper deals with the optimization of the ratio of two linear functions subject to a set of linear constraints with the additional restriction that the optimal solution is to be an extreme point of another convex polyhedron. In this paper, an enumerative procedure for solving such type of problems is developed. For an illustration, a numerical example is also provided.

Summary In this paper a “Strong-Cut Enumerative Procedure” for solving Extreme Point Mathematical Programming Problem:

The presence of N-acetylglucosamine is essential for the induced synthesis of N-acetylglucosamine kinase in Candida albicans. The enzyme synthesis stops and its concentration in the cells declines rapidly as soon as N-acetylglucosamine is removed from the medium. Experiments with RNA- and protein-synthesis inhibitors indicate that the appearance of new enzyme activity is dependent on concomitant new protein synthesis and the inducer operates at a transcriptional level.

The zeolite ZSM‐5 is usually synthesized in the presence of tetrapropylammonium ion, therefore, monitoring the vibrations of Pr4N+is used to examine the Raman spectra of the solution and solid phases present during various stages of ZSM‐5 synthesis.

The vibrational data of the solution and solid phases during zeolite Y formation indicate the presence of six‐membered aluminosilicate rings during nucleation, which act as building blocks.

The vibrational spectra of the (Al2Li(OH)6)+ framework exhibit characteristic bands due to AlO6and OH groups and indicate a D3 site symmetry of the AlO6units.