A note on the noncommutative correction to gravity

An apparent contradiction in the leading order correction to noncommutative (NC) gravity reported in the literature has been pointed out. We show by direct computation that actually there is no such controvarsy and all perturbative NC corrections start from the second order in the NC parameter. The role of symmetries in the vanishing of the first order correction is manifest in our calculation.Comment: Revtex, 3 pages, transferred from PRC to PRD, references added, this version to be published in Phys. Rev.

An analytical study of the interior ballistics problem, including movement of solids and wall heat transfer

M.S.S. V. Shelto

The role of potential in the ghost-condensate dark energy model

We consider the ghost-condensate model of dark energy with a generic potential term. The inclusion of the potential is shown to give greater freedom in realising the phantom regime. The self-consistency of the analysis is demonstrated using WMAP7+BAO+Hubble data.Comment: A new sub-section added, 13 pages, 3 figures, LaTex. paper thoroughly rewritten. arXiv admin note: substantial text overlap with arXiv:1301.4746; and text overlap with arXiv:1008.2182 by other author

Bosonic p-brane and A--D--M decomposition

A master action for the bosonic p-brane, interpolating between the Nambu--Goto and Polyakov formalisms, is discussed. The fundamental arbitrariness of extended structures (p-brane) embeded in space time manifold has been exploited to build an independent metric in the brane world volume. The cosmological term for the generic case follows naturally in the scheme. The dynamics of the structure leads to a natural emergence of the A--D--M like split of this world volume. The role of the gauge symmetries vis-\`{a}-vis reparametrization symmetries is analyzed by a constrained Hamiltonian approach.Comment: LaTeX, 14 pages, Title changed, paper extended, references added, this version is to appear in Phys. Rev.

EFFECTS OF DRIED LEAF POWDER OF OCIMUM SANCTUM IN HEXAMITA-INFECTED FISH ANABAS TESTUDINEUS

Objective: The prophylactic and antioxidative role of the dried powdered of Ocimum sanctum (Tulasi) was measured in Hexamita-infected fish Anabas testudineus. Method: Four groups of infected fish were kept in four separate aquariums and the following doses of leaf powder applied (25 mg, 50 mg, and 100 mg/L) for 10 days, and the first group is considered as control and no such treatment is given there. Results: Histopathology showed a remarkable alteration in the structure of liver tissue. Progressive changes observe along with the treatment schedule in hepatic histology and differential count of blood. Results showed that Hexamita infections significantly increased (p<0.05) the oxidative stress in the liver of infected fish. Whereas the treated fish exposed to different doses of powdered leaf of O. sanctum show significantly higher levels of antioxidant enzymes (Catalase, Superoxide dismutase, Glutathione peroxidase) and lower levels of stress marker (Malondialdehyde) than control fish. This treatment caused a rapid skin formation in the scar region. The highest recovery found in 100 mg/L doses of leaf powder, whereas the least recovery found in 25 mg/L group. Conclusion: The findings of the present study may play a key role in aquaculture industry for controlling the death of fish from Hexamita infection

Interaction of 2-aminopyrimidine with dichloro-[1-alkyl-2-(naphthylazo) imidazole]palladium(II) complexes : Kinetic and mechanistic studies

<p>Abstract</p> <p>Background</p> <p>The anticancer properties of <it>cis</it>platin and palladium(II) complexes stem from the ability of the <it>cis</it>-MCl₂fragment to bind to DNA bases. However, <it>cis</it>platin also interacts with non-cancer cells, mainly through bonding molecules containing -SH groups, resulting in nephrotoxicity. This has aroused interest in the design of palladium(II) complexes of improved activity and lower toxicity. The reaction of DNA bases with palladium(II) complexes with chelating N,N^/donors of the <it>cis</it>-MCl₂configuration constitutes a model system that may help explore the mechanism of <it>cis</it>platin's anticancer activity. Heterocyclic compounds are found widely in nature and are essential to many biochemical processes. Amongst these naturally occurring compounds, the most thoroughly studied is that of pyrimidine. This was one of the factors that encouraged this study into the kinetics and mechanism of the interaction of 2-aminopyrimidine (2-NH₂-Pym) with dichloro-{1-alkyl-2-(α-naphthylazo)imidazole}palladium(II) [Pd(α-NaiR)Cl₂, <b>1] </b>and dichloro-{1-alkyl-2-(β-naphthylazo)imidazole}palladium(II) [Pd(β-NaiR)Cl₂, <b>2] </b>complexes where the alkyl R = Me (<b>a</b>), Et (<b>b</b>), or Bz (<b>c</b>).</p> <p>Results</p> <p>2-NH₂-Pym reacts with <b>1a</b>, <b>1b</b>, and <b>1c </b>to yield [{1-alkyl-2-(α-naphthylazo)imidazole}bis(2-aminopyrimidine)]palladium(II) (<b>3a, 3b, 3c</b>) dichloride and with <b>2a, 2b, </b>and <b>2c </b>to yield [{1-alkyl-2-(β-naphthylazo)imidazole}bis(2-aminopyrimidine)]palladium(II) (<b>4a, 4b, 4c</b>) dichloride in an acetonitrile (MeCN) medium. The products were characterized using spectroscopic techniques (FT-IR, UV-Vis, NMR). The ligand substitution reactions follow second order kinetics – first order dependence on the concentration of the Pd(II) complex and 2-NH₂-Pym. Addition of LiCl to the reaction does not influence its rate. The thermodynamic parameters (standard enthalpy of activation, Δ^‡H^°and standard entropy of activation, Δ^‡S^°) were determined from variable temperature kinetic studies. The magnitude of the second order rate constant, <it>k</it>₂, at 298 K, was shown to increase thus: <b>b </b><<b>a </b><<b>c </b>as well as <b>1 </b><<b>2</b>.</p> <p>Conclusion</p> <p>The kinetics of the reaction between Pd(II) complexes (<b>1 </b>and <b>2</b>) and 2-NH₂-Pym were examined spectrophotometrically at 530 nm in MeCN under pseudo-first-order conditions. The reaction rate is largely influenced by the π-acidity of the chelating ligand, with substitution in the naphthyl azoimidazole backbone influencing the rate of the substitution process. The activation parameters, Δ^‡H^°and Δ^‡S^°, were determined and support the kinetic rate data.</p