2,480 research outputs found

    Electromagnetic follow-up of gravitational wave transient signal candidates

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    Pioneering efforts aiming at the development of multi-messenger gravitational wave and electromagnetic astronomy have been made. An electromagnetic observation follow-up program of candidate gravitational wave events has been performed (Dec 17 2009 to Jan 8 2010 and Sep 4 to Oct 20 2010) during the recent runs of the LIGO and Virgo gravitational wave detectors. It involved ground-based and space electromagnetic facilities observing the sky at optical, X-ray and radio wavelengths. The joint gravitational wave and electromagnetic observation study requires the development of specific image analysis procedures able to discriminate the possible electromagnetic counterpart of gravitational wave triggers from contaminant/background events. The paper presents an overview of the electromagnetic follow-up program and the image analysis procedures.Comment: Proceedings of the 12th International Conference on "Topics in Astroparticle and Underground Physics" (TAUP 2011), Munich, September 2011 (to appear in IoP Journal of Physics: Conference Series

    Is it possible to enhance immune response after vaccination? The role of a probiotic with a proven positive effect on all components of the immune system

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    Preventive vaccination is currently the most affordable and economical way to reduce morbidity and mortality from many infections, improve quality and human life expectancy with an almost ideal balance of benefits and risks among all medical procedures. The article deals with the reasons for variability of the immune response caused by vaccines, between individuals and between populations, which is of fundamental importance for human health. The authors have presented data indicating a key role of the gut microbiota in the control of the immune response to vaccination. Particular attention is paid to the microbial diversity in different loci of the body. The role of microorganisms in the proper functioning of the body and the formation of a number of pathological conditions is described. Most modern vaccines are live-attenuated, killed / inactivated or subunit (recombinant) vaccines, and they are designed for the parenteral route of administration. Most of these vaccines elicit a weak immune response, especially in the mucous membranes, due to the route of administration and are associated with weak cell-mediated immunity. Therefore, mechanisms that can enhance virus-specific vaccine immunity in infants and children are required, such as the use of more potent or selective immunity-enhancing adjuvants. Some probiotic strains may be considered as promising vaccine adjuvants. This article evaluates the recent clinical studies of probiotics used to enhance vaccine-specific immunity in adults and infants. The present-day knowledge on the role of the probiotic strain Lactobacillus rhamnosus GG with the aim of activating immunity after vaccination are presented

    Infant colic: from theory to practice

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    Infant colic is one of the most common, yet least studied, functional disorders of the gastrointestinal tract. Until now, there is no certainty both in the understanding of the nature of this condition and in the approaches to its correction. At the same time, infant crying is of concern to parents, forcing them to seek professional help and incur considerable medical expenses and to resort, sometimes unreasonably, to dietary and medical corrections. This article provides information on the etiology, pathogenesis and management of infantile colic from an evidence-based perspective, based on a review of the current literature. Various preconditions for the occurrence and development of infantile colic are analysed in detail, none of which can affect all occurrences. Evidence for the proven efficacy of including Lactobacillus reuteri in the treatment of intestinal colic in infants is presented. Effects on the gastrointestinal tract microbiome can be of undeniable benefit. Lactobacillus reuteri is one of the most studied and scientifically documented probiotics. 203 completed clinical trials involving 17,200 participants, including 67 trials involving 8,200 participants between 0 and 3 years of age. Numerous placebo-controlled studies have shown that taking Lactobacillus reuteri DSM 17938 can significantly reduce crying time in infants with colic, and in these studies, rates of 50% or more reduction in crying time were 2.3 times higher compared to controls

    Phase Diagram for Charge Density Waves in a Magnetic Field

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    The influence of an external magnetic field on a quasi one-dimensional system with a charge density wave (CDW) instability is treated within the random phase approximation which includes both CDW and spin density wave correlations. We show that the CDW is sensitive to both orbital and Pauli effects of the field. In the case of perfect nesting, the critical temperature decreases monotonously with the field, and the wave vector of the instability starts to shift above some critical value of magnetic field. Depending on the ratio between the spin and charge coupling constants and on the direction of the applied magnetic field, the wave vector shift is either parallel (CDWxCDW_x order) or perpendicular (CDWyCDW_y order) to the most conducting direction. The CDWxCDW_x order is a field dependent linear combination of the charge and spin density waves and is sensible only to the Pauli effect. The wave vector shift in CDWyCDW_y depends on the interchain coupling, but the critical temperature does not. This order is affected by the confinement of the electronic orbits. By increasing the relative strength of the orbital effect with respect to the Pauli effect, one can destroy the CDWyCDW_y, establishing either a CDWxCDW_x, or a CDW0CDW_0 (corresponding to perfect nesting wave vector). We also show that by increasing the imperfect nesting parameter, one passes from the regime where the critical temperature decreases with the field to the regime where it is initially enhanced by the orbital effect and eventually suppressed by the Pauli effect. For a bad nesting, the quantized phases of the field-induced CDW appear.Comment: 30 pages (LaTeX) + 15 figure

    Searching for prompt signatures of nearby core-collapse supernovae by a joint analysis of neutrino and gravitational-wave data

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    We discuss the science motivations and prospects for a joint analysis of gravitational-wave (GW) and low-energy neutrino data to search for prompt signals from nearby supernovae (SNe). Both gravitational-wave and low-energy neutrinos are expected to be produced in the innermost region of a core-collapse supernova, and a search for coincident signals would probe the processes which power a supernova explosion. It is estimated that the current generation of neutrino and gravitational-wave detectors would be sensitive to Galactic core-collapse supernovae, and would also be able to detect electromagnetically dark SNe. A joint GW-neutrino search would enable improvements to searches by way of lower detection thresholds, larger distance range, better live-time coverage by a network of GW and neutrino detectors, and increased significance of candidate detections. A close collaboration between the GW and neutrino communities for such a search will thus go far toward realizing a much sought-after astrophysics goal of detecting the next nearby supernova.Comment: 10 pages, 3 figures. To appear in Class. Quantum Gra

    Toward an optimal search strategy of optical and gravitational wave emissions from binary neutron star coalescence

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    Observations of an optical source coincident with gravitational wave emission detected from a binary neutron star coalescence will improve the confidence of detection, provide host galaxy localisation, and test models for the progenitors of short gamma ray bursts. We employ optical observations of three short gamma ray bursts, 050724, 050709, 051221, to estimate the detection rate of a coordinated optical and gravitational wave search of neutron star mergers. Model R-band optical afterglow light curves of these bursts that include a jet-break are extrapolated for these sources at the sensitivity horizon of an Advanced LIGO/Virgo network. Using optical sensitivity limits of three telescopes, namely TAROT (m=18), Zadko (m=21) and an (8-10) meter class telescope (m=26), we approximate detection rates and cadence times for imaging. We find a median coincident detection rate of 4 yr^{-1} for the three bursts. GRB 050724 like bursts, with wide opening jet angles, offer the most optimistic rate of 13 coincident detections yr^{-1}, and would be detectable by Zadko up to five days after the trigger. Late time imaging to m=26 could detect off-axis afterglows for GRB 051221 like bursts several months after the trigger. For a broad distribution of beaming angles, the optimal strategy for identifying the optical emissions triggered by gravitational wave detectors is rapid response searches with robotic telescopes followed by deeper imaging at later times if an afterglow is not detected within several days of the trigger.Comment: 6 pages, 1 figure, Accepted for publication in MNRAS Letters (2011 April 22

    Specific and general autobiographical knowledge in adults with autism spectrum disorders: The role of personal goals

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    Autobiographical knowledge is stored hierarchically, at both specific and general levels of representation. It has also been proposed that the self is the structure around which autobiographical memories are organised. The current series of studies assessed whether the autobiographical memory difficulties observed in adults with autism spectrum disorders (ASD) could be due to problems in using the self as an effective memory cue. A series of cueing paradigms were used to assess the accessibility of both specific and general autobiographical knowledge relating to (i) currently pursued goals (either high or low in self-concordance) and (ii) goals that participants were not currently pursuing. Results demonstrated that while event-specific knowledge was impaired in the ASD group, general event knowledge appeared relatively intact. Moreover, while both event-specific and general event knowledge were organised around goals of the self in control participants, a corresponding relationship was only observed for general event knowledge in the ASD group

    Pressure Tuning of the Charge Density Wave in the Halogen-Bridged Transition-Metal (MX) Solid Pt2Br6(NH3)4Pt_2Br_6(NH_3)_4

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    We report the pressure dependence up to 95 kbar of Raman active stretching modes in the quasi-one-dimensional MX chain solid Pt2Br6(NH3)4Pt_2Br_6(NH_3)_4. The data indicate that a predicted pressure-induced insulator-to-metal transition does not occur, but are consistent with the solid undergoing either a three-dimensional structural distortion, or a transition from a charge-density wave to another broken-symmetry ground state. We show that such a transition cacan be well-modeled within a Peierls-Hubbard Hamiltonian. 1993 PACS: 71.30.+h, 71.45.Lr, 75.30.Fv, 78.30.-j, 81.40.VwComment: 4 pages, ReVTeX 3.0, figures available from the authors on request (Gary Kanner, [email protected]), to be published in Phys Rev B Rapid Commun, REVISION: minor typos corrected, LA-UR-94-246
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