277 research outputs found

    Indications to hospital admission and isolation of children with possible or defined tuberculosis : Systematic review and proposed recommendations for pediatric patients leaving in developed countries

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    Tuberculosis (TB) is a re-emerging health problem in developed countries. This paper is part of large guidelines on the global management of TB in children, by a group of scientific societies. It describes the indications to hospitalization of children with suspected or diagnosed TB, the isolation measures, hospital discharge, and re-admission into the community. Using the Consensus Conference method, relevant publications in English were identified by means of a systematic review of MEDLINE and the Cochrane Database of Systematic Reviews from their inception until 31 December 2014. Available data on indications to hospitalization were mainly indirect and largely derived from observational studies. They include: (1) host-related risk factors, the main being age <12 months, immune deficiencies, and malnutrition; (2) TB-related clinical conditions that resemble those of pneumonia but also include drug-resistance; and (3) social and logistic conditions. The latter are based on opinion and depend on local conditions. Analysis of the literature showed that patients hospitalized with suspected pulmonary TB should be put in precautionary respiratory isolation regardless of their age while they await diagnosis. The general conditions for re-admission into the community are at least 14 days of effective treatment and negative microscopic tests of 3 consecutive samples in previously microscopically positive patients. This is the first paper that provides indications to hospitalization of children with TB. Most recommendations are generally applicable in all developed countries. Some might need an adaptation to local setting, epidemiological, parameters, and availability of specific health-care facilities

    Practical issues in early switching from intravenous to oral antibiotic therapy in children with uncomplicated acute hematogenous osteomyelitis: Results from an italian survey

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    Background: The European Society of Pediatric Infectious Diseases (ESPID) guidelines for acute hematogenous osteomyelitis (AHOM) have been published recently. In uncomplicated cases, an early (2-4 days) switch to oral empirical therapy, preferentially with flucloxacillin, is recommended in low methicillin-resistant Staphylococcus aureus settings. We conducted a survey with the aim of evaluating the behaviors of Italian pediatricians at this regard. Methods: An open-ended questionnaire investigating the empiric therapy adopted in uncomplicatedAHOMchildren according to age was sent by email to 31 Italian pediatric clinics taking care of children with infectious diseases, and results were analyzed. Results: The preferred intravenous (IV) regimen was a penicillin plus an aminoglycoside (n = 10; 32.3%) in children aged &lt;3 months, and a combination of a third-generation cephalosporin plus oxacillin (n = 7; 22.6%), or oxacillin alone (n = 6; 19.4%) in those 653 months. In every age class, amoxicillin-clavulanate was the first-choice oral antibiotic. Other antibiotics largely used orally included clindamycin, rifampicin, and trimethoprim/sulfamethoxazole. Flucloxacillin was never prescribed. Only 3 centers switched to oral therapy within 7 days in children 653 months of age. The most commonly reported reason influencing the time to switch to oral therapy concerned caregivers\u2019 adherence to oral therapy. Conclusion: Adherence to guidelines was poor, and early transition to oral therapy in the clinical practice was rarely adopted. Given the large use of potentially effective, but poorly studied, oral antibiotics such as amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, and rifampicin, our data may stimulate further studies of this regard

    A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

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    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

    Mechanical Behavior and Microstructural Development of Low-Carbon Steel and Microcomposite Steel Reinforcement Bars Deformed under Quasi-Static and Dynamic Shear Loading

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    Reinforcement bars of microcomposite (MC) steel, composed of lath martensite and minor amounts of retained austenite, possess improved strength and corrosion characteristics over low-carbon (LC) steel rebar; however, their performance under shear loading has not previously been investigated at the microstructural level. In this study, LC and MC steel cylinders were compression tested, and specimens machined into a forced-shear geometry were subjected to quasi-static and dynamic shear loading to determine their shear behavior as a function of the strain and strain rate. The as-received and sheared microstructures were examined using optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). Higher-resolution microstructural examinations were performed using transmission electron microscopy (TEM). The influence of the starting microstructure on the shear behavior was found to depend strongly on the strain rate; the MC steel exhibited not only greater strain-rate sensitivity than the LC steel but also a greater resistance to shear localization with load. In both steels, despite differences in the starting microstructure, post-mortem observations were consistent with a continuous mechanism operating within adiabatic shear bands (ASBs), in which subgrains rotated into highly misoriented grains containing a high density of dislocations

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    All-sky search for long-duration gravitational wave transients with initial LIGO

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    We present the results of a search for long-duration gravitational wave transients in two sets of data collected by the LIGO Hanford and LIGO Livingston detectors between November 5, 2005 and September 30, 2007, and July 7, 2009 and October 20, 2010, with a total observational time of 283.0 days and 132.9 days, respectively. The search targets gravitational wave transients of duration 10-500 s in a frequency band of 40-1000 Hz, with minimal assumptions about the signal waveform, polarization, source direction, or time of occurrence. All candidate triggers were consistent with the expected background; as a result we set 90% confidence upper limits on the rate of long-duration gravitational wave transients for different types of gravitational wave signals. For signals from black hole accretion disk instabilities, we set upper limits on the source rate density between 3.4×10-5 and 9.4×10-4 Mpc-3 yr-1 at 90% confidence. These are the first results from an all-sky search for unmodeled long-duration transient gravitational waves. © 2016 American Physical Society

    Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

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    The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

    Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

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    We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

    Erratum: "A Gravitational-wave Measurement of the Hubble Constant Following the Second Observing Run of Advanced LIGO and Virgo" (2021, ApJ, 909, 218)

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    [no abstract available

    Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

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    We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society
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