Modulus stabilization of generalized Randall Sundrum model with bulk scalar field

We study the stabilization of inter-brane spacing modulus of generalized warped brane models with a nonzero brane cosmological constant. Employing Goldberger-Wise stabilization prescription of brane world models with a bulk scalar field, we show that the stabilized value of the modulus generally depends on the value of the brane cosmological constant. Our result further reveals that the stabilized modulus value corresponding to a vanishingly small cosmological constant can only resolve the gauge hierarchy problem simultaneously. This in turn vindicates the original Randall-Sundrum model where the 3-brane cosmological constant was chosen to be zero.Comment: 12 Pages, 1 figure, Revtex, Version to appear in Euro. Phys. Let

In vitro antimicrobial activity of cefsulodin and kanamycin in combinations

Background:Infectious diseases are the greatest challenge of the world. The main failure in the treatment of infectious diseases is development of antibiotic resistance by the infective agents. Combination drug therapy is proposed to be more successful to contain diseases. But before the selection of combination of antibiotics, it is important to determine interaction of such antibiotics. Two antibiotics may have either synergistic or antagonistic action. In this study it was designed to find out the Minimum Inhibitory Concentration (MIC), and Minimum Bactericidal Concentration (MBC), which is usually used for the quantitative assessment of bacterial sensitivity to antibiotics.Methods:Checkerboard titration in microtitre trays used for this assay, and Fractional Inhibitory Concentration (FIC) and Fractional Bactericidal Concentration (FBC) measured to identify the type of interaction between the two antibiotics. Cefsulodin (Cef) and Kanamycin (Kan) were used against Escherechia coli (Esch. coli) and Staphylococcus aureus (Staph. aureus) to determine the efficacy of these antibiotics in combination.Results:MIC of cefsulodin and kanamycin against Staph. aureus was 3.125 and 3.125 respectively. MIC of Cef for Esch. coli was 6.25 and for Kan 50. FIC for Staph. aureus was 1. FIC for Esch. coli was different in different antibiotic concentrations and the least value was 0.37. There was no bactericidal effect of these antibiotics in combination against these organisms.Conclusion:Combination of two drugs cefsulodin and kanamycin showed synergistic action against Esch. coli and additive against Staph. aureus. So combined drug therapy can be used for better treatment with low toxicity, broad spectrum activity, and prevent emergence of drug resistance organism.

Galactic `Snake' IRDC G11.11−-0.12: a site of multiple hub-filament systems and colliding filamentary clouds

To probe star formation processes, we present a multi-scale and multi-wavelength investigation of the `Snake' nebula/infrared dark cloud G11.11$-$0.12 (hereafter, G11; length $\sim$27 pc). Spitzer images hint at the presence of sub-filaments (in absorption), and reveal four infrared-dark hub-filament system (HFS) candidates (extent $<$ 6 pc) toward G11, where massive clumps ($>$ 500 $M_{\odot}$) and protostars are identified. The $^{13}$CO(2-1), C$^{18}$O(2-1), and NH$_{3}$(1,1) line data reveal a noticeable velocity oscillation toward G11, as well as its left part (or part-A) around V$_{lsr}$ of 31.5 km s$^{-1}$, and its right part (or part-B) around V$_{lsr}$ of 29.5 km s$^{-1}$. The common zone of these cloud components is investigated toward the center's G11 housing one HFS. Each cloud component hosts two sub-filaments. In comparison to part-A, more ATLASGAL clumps are observed toward part-B. The JWST near-infrared images discover one infrared-dark HFS candidate (extent $\sim$0.55 pc) around the massive protostar G11P1 (i.e., G11P1-HFS). Hence, the infrared observations reveal multiple infrared-dark HFS candidates at multi-scale in G11. The ALMA 1.16 mm continuum map shows multiple finger-like features (extent $\sim$3500-10000 AU) surrounding a dusty envelope-like feature (extent $\sim$18000 AU) toward the central hub of G11P1-HFS. Signatures of forming massive stars are found toward the center of the envelope-like feature. The ALMA H$^{13}$CO$^{+}$ line data show two cloud components with a velocity separation of $\sim$2 km s$^{-1}$ toward G11P1. Overall, the collision process, the ``fray and fragment'' mechanism, and the ``global non-isotropic collapse'' scenario seem to be operational in G11.Comment: 20 pages, 13 figures, 3 Tables, Accepted for publication in Monthly Notices of the Royal Astronomical Society (MNRAS) Journa

Evaluation of hepatoprotective and antioxidant activity of Ichnocarpus frutescens (Linn.) R.Br. on paracetamol-induced hepatotoxicity in rats

Purpose: The entire plant including the flowers, of Ichnocarpus frutescens R.Br. (Apocynaceae) has been used for the treatment of cancer, skin infections, diabetes and liver disorder. The present study is aimed at evaluating the hepatoprotective effect of chloroform and methanol extract (CEIF and MEIF) of whole plant of I. frutescens (Linns) by paracetamol-induced liver damage in rats. Methods: The chloroform and methanolic extracts of I. frutescens (CEIF and MEIF) were studied for their hepatoprotective and antioxidant effects on paracetamol (750mg/kg) induced acute liver damage on Wistar albino rats. The degree of protection was measured by using biochemical parameters such as serum glutamate oxalate transaminase (SGOT) and serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), bilirubin and total protein. Further, the effects of both extracts on lipid peroxidation (LPO), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were estimated. Results: CEIF and MEIF at a dose level of 250mg/kg and 500mg/kg produce significant (

`Standard' Cosmological model & beyond with CMB

Observational Cosmology has indeed made very rapid progress in the past decade. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and, more recently, polarization have played a very important role. Besides precise determination of various parameters of the `standard' cosmological model, observations have also established some important basic tenets that underlie models of cosmology and structure formation in the universe -- `acausally' correlated initial perturbations in a flat, statistically isotropic universe, adiabatic nature of primordial density perturbations. These are consistent with the expectation of the paradigm of inflation and the generic prediction of the simplest realization of inflationary scenario in the early universe. Further, gravitational instability is the established mechanism for structure formation from these initial perturbations. The signature of primordial perturbations observed as the CMB anisotropy and polarization is the most compelling evidence for new, possibly fundamental, physics in the early universe. The community is now looking beyond the estimation of parameters of a working `standard' model of cosmology for subtle, characteristic signatures from early universe physics.Comment: 16 pages, 6 figures, Plenary talk, Proc. of GR-19, Mexico City, Mexico (Jul 5-9, 2010). To appear in a special issue in Class. Q. Gra

IC 5146 dark Streamer: is a first reliable candidate of edge collapse, hub-filament systems, and intertwined sub-filaments?

The paper presents an analysis of multi-wavelength data of a nearby star-forming site IC 5146 dark Streamer (d $\sim$600 pc), which has been treated as a single and long filament, fl. Two hub-filament systems (HFSs) are known toward the eastern and the western ends of fl. Earlier published results favor the simultaneous evidence of HFSs and the end-dominated collapse (EDC) in fl. Herschel column density map (resolution $\sim$13$''$.5) reveals two intertwined sub-filaments (i.e., fl-A and fl-B) toward fl, displaying a nearly double helix-like structure. This picture is also supported by the C$^{18}$O(3-2) emission. The scenario "fray and fragment" may explain the origin of intertwined sub-filaments. In the direction of fl, two cloud components around 2 and 4 km s$^{-1}$ are depicted using the $^{13}$CO(1-0) and C$^{18}$O(1-0) emission, and are connected in velocity space. The HFSs are spatially found at the overlapping areas of these cloud components and can be explained by the cloud-cloud collision scenario. Non-thermal gas motion in fl with larger Mach number is found. The magnetic field position angle measured from the filament's long axis shows a linear trend along the filament. This signature is confirmed in the other nearby EDC filaments, presenting a more quantitative confirmation of the EDC scenario. Based on our observational outcomes, we witness multiple processes operational in IC 5146 Streamer. Overall, the Streamer can be recognized as the first reliable candidate of edge collapse, HFSs, and intertwined sub-filaments together.Comment: 22 pages, 11 figures, Accepted for publication in The Astrophysical Journa

Detecting metrologically useful asymmetry and entanglement by a few local measurements

Important properties of a quantum system are not directly measurable, but they can be disclosed by how fast the system changes under controlled perturbations. In particular, asymmetry and entanglement can be verified by reconstructing the state of a quantum system. Yet, this usually requires experimental and computational resources which increase exponentially with the system size. Here we show how to detect metrologically useful asymmetry and entanglement by a limited number of measurements. This is achieved by studying how they affect the speed of evolution of a system under a unitary transformation. We show that the speed of multiqubit systems can be evaluated by measuring a set of local observables, providing exponential advantage with respect to state tomography. Indeed, the presented method requires neither the knowledge of the state and the parameter-encoding Hamiltonian nor global measurements performed on all the constituent subsystems. We implement the detection scheme in an all-optical experiment

Polyaniline-Based Nanocomposites for Environmental Remediation

With growth in civilisation and industrialisation, there is an increase in the release of toxic heavy metal ions and dyes into water system, which is of public concern. As a result, appropriate treatment methods have to be implemented in order to mitigate and prevent water pollution. The discovery of nanotechnology has led to the development and utilisation of various nanoadsorbent for the removal of pollutants from water. PANI nanostructures and nanocomposites are noble adsorbents that have gained popularity in addressing water pollution issues and have been reported in literature. In this chapter, the main focus is on the synthesis of PANI nanocomposites and nanostructures and their application as efficient adsorbents for water treatment. Detailed discussions on different synthetic routes and characterisation have been dedicated to applications of these materials and are compared for the adsorptive removal of heavy metal ions and dyes from water

Cosmology with CMB anisotropy

Measurements of CMB anisotropy and, more recently, polarization have played a very important role allowing precise determination of various parameters of the `standard' cosmological model. The expectation of the paradigm of inflation and the generic prediction of the simplest realization of inflationary scenario in the early universe have also been established -- `acausally' correlated initial perturbations in a flat, statistically isotropic universe, adiabatic nature of primordial density perturbations. Direct evidence for gravitational instability mechanism for structure formation from primordial perturbations has been established. In the next decade, future experiments promise to strengthen these deductions and uncover the remaining crucial signature of inflation -- the primordial gravitational wave background.Comment: Plenary talk at the IXth. International Workshop on High Energy Physics Phenomenology (WHEPP-9), Institute of Physics, Bhubaneshwar, India. Jan 3-14, 2006; To appear in the Proceedings to be published in Pramana; 12 pages, 2 figure