Spacetime Dependent Lagrangians and Weak-Strong Duality : Sine Gordon and Massive Thirring Models

The formalism of spacetime dependent lagrangians developed in Ref.1 is applied to the Sine Gordon and massive Thirring models.It is shown that the well-known equivalence of these models (in the context of weak-strong duality) can be understood in this approach from the same considerations as described in [1] for electromagnetic duality. A further new result is that all these can be naturally linked to the fact that the holographic principle has analogues at length scales much larger than quantum gravity. There is also the possibility of {\it noncommuting coodinates} residing on the boundaries. PACS: 11.15.-q: 11.10/EfComment: Latex, 16 pages, article shortened, references added, minor typos correcte

Physical properties of noncentrosymmetric superconductor LaIrSi3: A {\mu}SR study

The results of heat capacity C_p(T, H) and electrical resistivity \rho(T,H) measurements down to 0.35 K as well as muon spin relaxation and rotation (\muSR) measurements on a noncentrosymmetric superconductor LaIrSi3 are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal BaNiSn3-type structure (space group I4\,mm) of LaIrSi3. The bulk superconductivity is observed below T_c = 0.72(1) K. The intrinsic \Delta C_e/\gamma_n T_c = 1.09(3) is significantly smaller than the BCS value of 1.43, and this reduction is accounted by the \alpha-model of BCS superconductivity. The analysis of the superconducting state C_e(T) data by the single-band \alpha-model indicates a moderately anisotropic order parameter with the s-wave gap \Delta(0)/k_B T_c = 1.54(2) which is lower than the BCS value of 1.764. Our estimates of various normal and superconducting state parameters indicate a weakly coupled electron-phonon driven type-I s-wave superconductivity in LaIrSi3. The \muSR results also confirm the conventional type-I superconductivity in LaIrSi3 with a preserved time reversal symmetry and hence a singlet pairing superconducting ground state.Comment: 11 pages, 8 figures, 2 table

Chemical and kinetic evidence for an essential histidine in horseradish peroxidase for iodide oxidation

Horseradish peroxidase (HRP), when incubated with diethylpyrocarbonate (DEPC), shows a time-dependent loss of iodide oxidation activity. The inactivation follows pseudo-first order kinetics with a second order rate constant of 0.43 min-1 M-1 at 30°C and is reversed by neutralized hydroxylamine. The difference absorption spectrum of the modified versus native enzyme shows a peak at 244 nm, characteristic of N-carbethoxyhistidine, which is diminished by treatment with hydroxylamine. Correlation between the stoichiometry of histidine modification and the extent of inactivation indicates that out of 2 histidine residues modified, one is responsible for inactivation. A plot of the log of the reciprocal half-time of inactivation against log DEPC concentration further suggests that only 1 histidine is involved in catalysis. The rate of inactivation shows a pH dependence with an inflection point at 6.2, indicating histidine derivatization by DEPC. Inactivation due to modification of tyrosine, lysine, or cysteine has been excluded. CD studies reveal no significant change in the protein or heme conformation following DEPC modification. We suggest that a unique histidine residue is required for maximal catalytic activity of HRP for iodide oxidation

Study of Beta Equilibrated 2+1 Flavor Quark Matter in PNJL Model

We report a first case study of the phase diagram of 2+1 flavor strongly interacting matter in $\beta-$equilibrium, using the Polyakov$-$Nambu$-$Jona-Lasinio model. Physical characteristics of relevant thermodynamic observables have been discussed. A comparative analysis with the corresponding observables in the Nambu-Jona-Lasinio model is presented. We find distinct differences between the models in terms of a number of thermodynamic quantities like the speed of sound, specific heat, various number densities as well as entropy. The present study is expected to give us a better insight into the role that the superdense matter created in heavy ion collision experiments play in our understanding of the properties of matter inside the core of supermassive stars in the Universe

Chemical and kinetic evidence for an essential histidine residue in the electron transfer from aromatic donor to horseradish peroxidase compound I

Horseradish peroxidase, when incubated with diethyl pyrocarbonate (DEPC), a histidine-specific reagent, shows time-dependent inactivation to oxidize aromatic electron donor, guaiacol. The inactivation follows pseudo-first order kinetics with a second order rate constant of 0.67 min-1 M-1. The pH dependence of inactivation shows an inflection point at 6.02, indicating histidine derivatization by DEPC. A difference spectrum of modified versus native enzyme shows a peak at 244 nm for N-carbethoxyhistidine that is diminished by hydroxylamine. Stoichiometric studies indicate that out of 2 histidine residues modified, one is responsible for inactivation. A plot of log reciprocal half-time of inactivation against log DEPC concentration suggests that only 1 histidine is essential. From the computer-stimulated structure of horseradish peroxidase, we tentatively suggest that this critical histidine is most likely distal histidine 42. Binding studies show that this histidine is not involved in guaiacol binding. Modified enzyme forms compound I with H2O2 but not compound II, suggesting a block of electron transfer process. Modified compound I cannot oxidize guaiacol as evidenced by the absence of donor-induced spectral shift from 408 nm, suggesting a block of electron transfer from bound donor to compound I. We suggest that this tentatively identified distal histidine controls aromatic donor oxidation by regulating electron transport without affecting donor binding or compound I formation