The effect of glycerol and desmopressin on exercise performance and hydration in triathletes

Previous work from this laboratory has demonstrated an association between the suppression of c-myc expression and the antiproliferative activity of both topoisomerase II inhibitors and ionizing radiation in MCF-7 breast tumor cells. These findings suggested that suppression of c-myc expression could be related to the induction of DNA damage in this cell line. The present studies were designed to determine whether the inhibition of topoisomerase I (and the consequent induction of DNA strand breaks) would also result in the suppression of c-myc expression. At camptothecin concentrations of 1 microM and below, there was no detectable damage (single- or double-strand breaks) in bulk DNA or suppression of c-myc expression. At camptothecin concentrations of 5, 10, and 25 microM, where suppression of c-myc expression was observed, strand breaks in bulk DNA were also detected. These findings are consistent with the idea that suppression of c-myc expression could be a component of the DNA damage response pathway in MCF-7 breast tumor cells. In contrast to the absence of detectable damage to bulk DNA or suppression of c-myc expression at the lower concentrations of camptothecin, DNA synthesis was inhibited over the entire range of drug concentrations and demonstrated a strong correspondence with growth inhibition. These observations support the concept that growth inhibition of MCF-7 cells by camptothecin is closely related to the early suppression of DNA synthesis.     

On hardware/software trade-offs in computer system design

The communication path between the computer users and the computer manufacturer is not a very effective one, but it is the vehicle whereby hardware/software trade-offs are realized. The purpose of this paper is to discuss the concept of hardware/software trade-offs from the perspective of the hardware designer. Primarily, the paper will examine software oriented functions/goals/requirements and discuss considerations in determining the kind of hardware support which would be involved in implementing the particular concept.     

Electronic structure of conducting π-electron systems

We will discuss the application of one-electron band theory to several systems where π-electron delocalization has been experimentally established. We will use polyacetylene as our prototype and extend results on it to related polymers such as (SN)_x, polypyrrole and poly(p-phenylene). We will particularly concentrate on those aspects of chemical bonding and symmetry which govern whether a given system will be semiconducting or metallic, and which scale its transport properties.     

Evidence for facilitated transport in the absorption of sterols bySaccharomyces cerevisiae

Saccharomyces cerevisiae is known to absorb sterols readily in the absence of air. As shown in this paper yeast cells also will absorb sterols with and without various double bonds or an alkyl group at C-24 in the presence of air at a concentration (ca. 10% of the gas phase) which is growth-limiting due to limited sterol synthesis. However, if the growth conditions are changed to be fully aerobic, sterol is no longer absorbed to any significant extent even when the sterol in the medium (ergosterol) is the same as that present in the cells. This implies that sterol in the medium does not equilibrate passively with sterol in the plasma membrane and that some sort of facilitated transport, which can be turned on and off, is responsible for the entry of sterol when it occurs as a response to an inadequate endogenous supply of sterol. In agreement with facilitated transport mediated by protein binding, yeast cells in an auxotrophic state for sterol exhibit a high degree of stereoselectivity with respect to the orientation of the side chain around the C-17(20)-bond. For instance, E-17(20)- but not Z-17(20)-dehydrocholesterol is absorbed by cells undergoing limited growth with 10% air.     

Trigonometric entropies,Jensen difference divergence measures,and error bounds

Various authors have attempted to characterize generalized entropies which in special cases reduce to the Shannon entropy. In this paper, we also characterize new trigonometric entropies, and some information-theoretic properties are studied. Bounds on the Bayesian probability of error in terms of trigonometric entropies and Jensen difference divergence measures have been obtained. Ideas of paired entropies applied to statistical mechanics and fuzzy set theory are also discussed.     

Maintenance of reliable real time systems: Hardware versus software tradeoffs

The maintenance features in a high reliability real time control system form an important component in the total system. It is essential that software and hardware maintenance features function in an effective manner to ensure a high level of reliability in real time systems. Hardware maintenance features include redundant processors, self-checking circuits, diagnostic microcode etc., while software maintenance features include fault recovery programmes, audits, diagnostics etc. In this paper, we examine briefly the relationship of maintenance software to hardware in current high reliability real time systems, and how this relationship is likely to change in the future. Discussion in the paper centres around issues such as: factors that contribute to effective maintenance design; hardware characteristics that affect software; partitioning of maintenance functions between software, firmware and hardware; and current trends in maintenance of real time systems.     

Empirical prediction of overall reliability in computer communication networks

Incorporation of an overall reliability parameter in the design of reliable computer communication networks makes the computation prohibitive. A composite reliability index based on the network topological parameters has been presented [1], which is very simple to evaluate and gives computation while designing maximally reliable computer networks as compared to the techniques based on several reliability measures. In this paper, we use the tabulated results of Soi and Aggarwal [1] and develop empirical formulae which can be used for quick estimation of overall reliability of a computer network for a specified value of the link reliability.     

Nitrophenates of transition metals1 part II. DTA,explosion delay,impact and friction sensitivity studies

Abstract

Thermolysis of nitrophenates (C-NO₂ explosives) of transition metals of 3d-series have been studied by DTA, impact, friction, and explosion delay measurements. Explosion delay (D_E), explosion temperature (ET), activation energy for explosion (E?), and height for 50% explosion (h_50%) have been found to be in the order: trinitro<dinitro<p mononitrophenates of transition metals. Only trinitrophenates have been found to be friction sensitive. It has been observed that these salts dehydrate below 140°C and at higher temperatures corresponding metal oxide and nitrosubstituted diphenylethers (as intermediates) are formed. The oxidative decomposition reactions seem to occur in adsorbed phase between NO₂, MO, and radical species leading to explosion.     

Studies on energetic compounds: Part 6 synthesis of ring-substituted arylammonium salts of 3-nitro-1,2,4-triazole-5-one(NTO)

Abstract

In continuation of our programme of preparing new energetic materials, fifteen arylammonium (having electron donating or attracting substituents) salts of 3-Nitro-1,2,4-triazole-5-one (NTO) have been synthesised and characterised. These compounds have been found to be ionic in nature.     

Free convective mass transfer at corrugated surfaces in relation to catalytic and electrochemical reactor design

The free convective mass transfer behavior of V-corrugated horizontal and vertical surfaces was studied by measuring the limiting current of the cathodic deposition of copper from acidified copper sulphate solution. Variables studied were peak-to-valley height and angle of the V-grooves, physical properties of the solution and vertical electrode height. For vertical corrugated surfaces, the data were correlated by the equation:

Sh=0.78(ScGr)^0.26