17,885 research outputs found

    Anti Microbial Resistance Profile of E. coli isolates From Tropical Free Range Chickens

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    Normal intestinal flora of humans and animals constitute enormous reservoir of resistance genes for potentially pathogenic bacteria and may serve as major indictors of selection pressure exerted by anti-microbial use in a given population. A study was conducted in September 2003 at 3 purposively selected peri-urban sites spread across 3 senatorial zones of Imo state, Nigeria to determines the anti-microbial resistance profile of commensal E. coli isolated from free range chickens. The isolates were screened for anti-microbial resistance profile against 10 antibiotics using the disc diffusion method. E. coli strains from local fowls, recorded 100 and 78.9% resistances against ampicillin and cotrimoxazole respectively, while resistance rates against ciprofloxacin, gentamycin and norfloxacin were 0.0, 5.3 and 5.3% respectively. Isolates from free-range cockerels recorded 100% resistance against norfloxacin, cotrimoxazole and ampicillin and 83.3% against nitrofurantoin. Similarly, isolates from old layers, recorded 100% resistance against nitrofurantoin, cotrimoxazole, tetracycline, chloramphenicol and ampicillin and 80% against nalidixic acid. Similar resistance trends were observed in E. coli isolates from free-range turkeys and broiler roosters against the inexpensive broad-spectrum first line antibiotics (ampicillin, nalidixic acid, cotrimoxazole, nitrofurantoin and chloramphenicol), although values varied slightly across poultry types. Resistances against gentamycin were consistently low in isolates from the different types of poultry. Twenty-nine resistance patterns were observed in the E. coli isolates with predominant patterns being distributed widely across poultry types indicating a striking diversity of resistance patterns in the areas

    Implementation pathway report: Community Resource Person An intervention by the Technical Support Unit Uttar Pradesh, India, February 2015

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    A report describing the methodology behind an implementation pathway for the Community Resource Person innovation being implemented by the Technical Support Unit (a large-scale collaboration between the Bill & Melinda Gates Foundation and the Uttar Pradesh government) in Uttar Pradesh, India

    Nature of light correlations in ghost imaging

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    We investigate the nature of correlations in Gaussian light sources used for ghost imaging. We adopt methods from quantum information theory to distinguish genuinely quantum from classical correlations. Combining a microscopic analysis of speckle-speckle correlations with an effective coarse-grained description of the beams, we show that quantum correlations exist even in `classical'-like thermal light sources, and appear relevant for the implementation of ghost imaging in the regime of low illumination. We further demonstrate that the total correlations in the thermal source beams effectively determine the quality of the imaging, as quantified by the signal-to-noise ratio.Comment: 12 pages, 5 figures. To appear in Scientific Reports (NPG

    Exact Relativistic Static Charged Dust Disks and Non-axisymmetric Structures

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    The well-known ``displace, cut and reflect'' method used to generate disks from given solutions of Einstein field equations is applied to the superposition of twoextreme Reissner-Nordstrom black holes to construct disks made of charged dust and alsonon-axisymmetric planar distributions of charged dust on the z=0 plane. They are symmetric with respect to twoor one coordinate axes, depending whether the black holes have equal or unequal masses, respectively.For these non-axisymmetric distributions of matter we also study the effective potential for geodesic motion of neutral test particles.Comment: Classical and Quantum Gravity (in press). 15 pages, LaTex, 8 .eps fig

    Infrared response of ordered polarons in layered perovskites

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    We report on the infrared absorption spectra of three oxides where charged superlattices have been recently observed in diffraction experiments. In La1.67_{1.67}Sr0.33_{0.33}NiO4_4, polaron localization is found to suppress the low-energy conductivity through the opening of a gap and to split the E2uE_{2u}-A2uA_{2u} vibrational manifold of the oxygen octahedra. Similar effects are detected in Sr1.5_{1.5}La0.5_{0.5}MnO4_4 and in La2_2NiO4+y_{4+y}, with peculiar differences related to the type of charge ordering.Comment: File latex, 11 p. + 3 Figures, to appear on Phys. Rev. B (Rapid Commun.), 1 Oct. 1996. The figures will be faxed upon request. E-mail:[email protected] Fax: +39-6-446315

    On the Detectability of Galactic Dark Matter Annihilation into Monochromatic Gamma-rays

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    Monochromatic gamma-rays are thought to be the smoking gun signal for identifying the dark matter annihilation. However, the flux of monochromatic gamma-rays is usually suppressed by the virtual quantum effects since dark matter should be neutral and does not couple with gamma-rays directly. In the work we study the detection strategy of the monochromatic gamma-rays in a future space-based detector. The monochromatic gamma-ray flux is calculated by assuming supersymmetric neutralino as a typical dark matter candidate. We discuss both the detection focusing on the Galactic center and in a scan mode which detects gamma-rays from the whole Galactic halo are compared. The detector performance for the purpose of monochromatic gamma-rays detection, with different energy and angular resolution, field of view, background rejection efficiencies, is carefully studied with both analytical and fast Monte-Carlo method

    Modeling ϵ\epsilon Eridani and asteroseismic tests of element diffusion

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    Taking into account the helium and metal diffusion, we explore the possible evolutionary status and perform seismic analysis of MOST target: the star ϵ\epsilon Eridani. We adopt the different input parameters to construct the models by fitting the available observational constraints: e.g., TeffT_{eff}, LL, RR, [Fe/H][Fe/H]. From computation, we obtain the average large spacings of ϵ\epsilon Eridani about 194±1μ194\pm 1 \muHz. The age of the diffused models has been found to be about 1 Gyr, which is younger than one determined previously by models without diffusion. We found that the effect of pure helium diffusion on the internal structure of the young low-mass star is slight, but the metal diffusion influence is obvious. The metal diffusion leads the models to have much higher temperature in the radiation interior, correspondingly the higher sound speed in the interior of the model, thereby the larger frequency and spacings.Comment: 16 pages, 4 figures, accepted for publication in ChjA

    The Statistics of Density Peaks and the Column Density Distribution of the Lyman-Alpha Forest

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    We develop a method to calculate the column density distribution of the Lyman-alpha forest for column densities in the range 1012.51014.5cm210^{12.5} - 10^{14.5} cm^{-2}. The Zel'dovich approximation, with appropriate smoothing, is used to compute the density and peculiar velocity fields. The effect of the latter on absorption profiles is discussed and it is shown to have little effect on the column density distribution. An approximation is introduced in which the column density distribution is related to a statistic of density peaks (involving its height and first and second derivatives along the line of sight) in real space. We show that the slope of the column density distribution is determined by the temperature-density relation as well as the power spectrum on scales 2hMpc1<k<20hMpc12 h Mpc^{-1} < k < 20 h Mpc^{-1}. An expression relating the three is given. We find very good agreement between the column density distribution obtained by applying the Voigt-profile-fitting technique to the output of a full hydrodynamic simulation and that obtained using our approximate method for a test model. This formalism then is applied to study a group of CDM as well as CHDM models. We show that the amplitude of the column density distribution depends on the combination of parameters (Ωbh2)2T00.7JHI1(\Omega_b h^2)^2 T_0^{-0.7} J_{HI}^{-1}, which is not well-constrained by independent observations. The slope of the distribution, on the other hand, can be used to distinguish between different models: those with a smaller amplitude and a steeper slope of the power spectrum on small scales give rise to steeper distributions, for the range of column densities we study. Comparison with high resolution Keck data is made.Comment: match accepted version; discussion added: the effect of the shape of the power spectrum on the slope of the column density distributio
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