67,044 research outputs found

    On multiplicity correlations in the STAR data

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    The STAR data on the multiplicity correlations between narrow psudorapidity bins in the pp and AuAu collisions are discussed. The PYTHIA 8.145 generator is used for the pp data, and a naive superposition model is presented for the AuAu data. It is shown that the PYTHIA generator with default parameter values describes the pp data reasonably well, whereas the superposition model fails to reproduce the centrality dependence seen in the data. Some possible reasons for this failure and a comparison with other models are presented.Comment: 8 pages, 3 figure

    A Trial of a 7-Valent Pneumococcal Conjugate Vaccine in HIV-Infected Adults.

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    BACKGROUND: Streptococcus pneumoniae is a leading and serious coinfection in adults with human immunodeficiency virus (HIV) infection, particularly in Africa. Prevention of this disease by vaccination with the current 23-valent polysaccharide vaccine is suboptimal. Protein conjugate vaccines offer a further option for protection, but data on their clinical efficacy in adults are needed. METHODS: In this double-blind, randomized, placebo-controlled clinical efficacy trial, we studied the efficacy of a 7-valent conjugate pneumococcal vaccine in predominantly HIV-infected Malawian adolescents and adults who had recovered from documented invasive pneumococcal disease. Two doses of vaccine were given 4 weeks apart. The primary end point was a further episode of pneumococcal infection caused by vaccine serotypes or serotype 6A. RESULTS: From February 2003 through October 2007, we followed 496 patients (of whom 44% were male and 88% were HIV-seropositive) for 798 person-years of observation. There were 67 episodes of pneumococcal disease in 52 patients, all in the HIV-infected subgroup. In 24 patients, there were 19 episodes that were caused by vaccine serotypes and 5 episodes that were caused by the 6A serotype. Of these episodes, 5 occurred in the vaccine group and 19 in the placebo group, for a vaccine efficacy of 74% (95% confidence interval [CI], 30 to 90). There were 73 deaths from any cause in the vaccine group and 63 in the placebo group (hazard ratio in the vaccine group, 1.18; 95% CI, 0.84 to 1.66). The number of serious adverse events within 14 days after vaccination was significantly lower in the vaccine group than in the placebo group (3 vs. 17, P=0.002), and the number of minor adverse events was significantly higher in the vaccine group (41 vs. 13, P=0.003). CONCLUSIONS: The 7-valent pneumococcal conjugate vaccine protected HIV-infected adults from recurrent pneumococcal infection caused by vaccine serotypes or serotype 6A. (Current Controlled Trials number, ISRCTN54494731.) Copyright 2010 Massachusetts Medical Society

    Holographic models for undoped Weyl semimetals

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    We continue our recently proposed holographic description of single-particle correlation functions for four-dimensional chiral fermions with Lifshitz scaling at zero chemical potential, paying particular attention to the dynamical exponent z = 2. We present new results for the spectral densities and dispersion relations at non-zero momenta and temperature. In contrast to the relativistic case with z = 1, we find the existence of a quantum phase transition from a non-Fermi liquid into a Fermi liquid in which two Fermi surfaces spontaneously form, even at zero chemical potential. Our findings show that the boundary system behaves like an undoped Weyl semimetal.Comment: 64 pages, 19 figure

    Pulsating Strings in Lunin-Maldacena Backgrounds

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    We consider pulsating strings in Lunin-Maldacena backgrounds, specifically in deformed Minkowski spacetime and deformed AdS_5xS^5. We find the relation between the energy and the oscillation number of the pulsating string when the deformation is small. Since the oscillation number is an adiabatic invariant it can be used to explore the regime of highly excited string states. We then quantize the string and look for such a sector. For the deformed Minkowski background we find a precise match with the classical results if the oscillation number is quantized as an even number. For the deformed AdS_5xS^5 we find a contribution which depends on the deformation parameter.Comment: 16 pages, 2 figures, typos fixe

    Analysis of Metal Content of Samples of Gloriosa Superba L (Colchicaceae) Collected from Two Different Locations in Pakistan

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    Purpose: To determine the metallic content of different parts of Gloriosa superba collected from two different locations in Pakistan, and also to assess their nutritious values and toxic levels.Methods: The plant material and soil were collected from two different locations - polluted and unpolluted. Wet digestion method was used for the preparation of samples (whole plant and soil) followed by analysis using flame atomic absorption spectrophotometer (for micronutrients) and flame photometry (for macronutrients).Results: Of the detected micronutrients, high concentrations of Zn, Fe and Mn were noted for samples collected from both areas. These values were within permissible limits. Samples collected from the polluted area contained Cu (7.5 – 13.0 ppm), Cr (1.4 − 1.9 ppm) and Ni (0.3 − 2.0 ppm), all of which exceeded acceptable limits; the same nutrients were mostly within acceptable limits for samples collected from the unpolluted area. Significant presence of macronutrients - Ca, Na and K - were observed in samples obtained from both areas.Conclusion: Proper validation of medicinal plants used for therapeutic purposes should be mandatory on safety grounds to protect consumers from contaminants.Keywords: Gloriosa superba, Micronutrients, Macronutrients, Toxicity, Metal ions, Medicinal plant

    The Spin of Holographic Electrons at Nonzero Density and Temperature

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    We study the Green's function of a gauge invariant fermionic operator in a strongly coupled field theory at nonzero temperature and density using a dual gravity description. The gravity model contains a charged black hole in four dimensional anti-de Sitter space and probe charged fermions. In particular, we consider the effects of the spin of these probe fermions on the properties of the Green's function. There exists a spin-orbit coupling between the spin of an electron and the electric field of a Reissner-Nordstrom black hole. On the field theory side, this coupling leads to a Rashba like dispersion relation. We also study the effects of spin on the damping term in the dispersion relation by considering how the spin affects the placement of the fermionic quasinormal modes in the complex frequency plane in a WKB limit. An appendix contains some exact solutions of the Dirac equation in terms of Heun polynomials.Comment: 27 pages, 11 figures; v2: minor changes, published versio

    Composition of the froth secreted by different spittlebug species.

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    The froth secreted by the spittlebugs protects the immature forms of these pests of pasture and agriculture from environmental damages. Frothes from Deois flavopicta, Mahanarva fimbriolata, Aeneolamia selecta selecta and Deois sp. (schach group) were compared for the purpose of establishing differences that could refleted upon control of these insects. The preparations were analyzed with topochemical methods and polarization microscopy. All of them were found to contain structural proteins and proteoglycans. However, the frothes of M. fimbriolata and Deois sp. appear to differ from the others in terms of anisotropic properties after staining with alcian blue, especially at pH 1.0. Differences in the acid glycosaminoglycans of these frothes, endowing them withdifferent responses to chemical and biological assays for control of these insects is thus suggested

    Emission Characteristics of the Projectile Fragments at Relativistic Energy

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    A projectile (84^Kr_36) having kinetic energy around 1 A GeV was used to expose NIKFI BR-2 emulsion target. A total of 700 inelastic events are used in the present studies on projectile fragments. The emission angle of the projectile fragments are strongly affected by charge of the other projectile fragments emitted at same time with different emission angle is observed. The angular distribution studies show symmetrical nature for lighter charge projectile fragments. The symmetrical nature decreased with the charge of projectile fragments. At ~4o of emission angle for double charge projectile fragments, the momentum transfer during interaction is similar for various target species of emulsion were observed. We also observed a small but significant amplitude peaks on both side of the big peak for almost all light charge projectile fragments having different delta angle values. It reflects that there are few percent of projectile fragments that are coming from the decay of heavy projectile fragments or any other process.Comment: 32 pages, 17 Figure
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