7 research outputs found

    Investigation of the correlation patterns and the Compton dominance variability of Mrk 421 in 2017

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    Aims. We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with a special focus on the multi-band flux correlations.Methods. The dataset has been collected through an extensive multi-wavelength campaign organised between 2016 December and 2017 June. The instruments involved are MAGIC, FACT, Fermi-LAT, Swift, GASP-WEBT, OVRO, Medicina, and Metsahovi. Additionally, four deep exposures (several hours long) with simultaneous MAGIC and NuSTAR observations allowed a precise measurement of the falling segments of the two spectral components.Results. The very-high-energy (VHE; E > 100 GeV) gamma rays and X-rays are positively correlated at zero time lag, but the strength and characteristics of the correlation change substantially across the various energy bands probed. The VHE versus X-ray fluxes follow different patterns, partly due to substantial changes in the Compton dominance for a few days without a simultaneous increase in the X-ray flux (i.e., orphan gamma-ray activity). Studying the broadband spectral energy distribution (SED) during the days including NuSTAR observations, we show that these changes can be explained within a one-zone leptonic model with a blob that increases its size over time. The peak frequency of the synchrotron bump varies by two orders of magnitude throughout the campaign. Our multi-band correlation study also hints at an anti-correlation between UV-optical and X-ray at a significance higher than 3 sigma. A VHE flare observed on MJD 57788 (2017 February 4) shows gamma-ray variability on multi-hour timescales, with a factor ten increase in the TeV flux but only a moderate increase in the keV flux. The related broadband SED is better described by a two-zone leptonic scenario rather than by a one-zone scenario. We find that the flare can be produced by the appearance of a compact second blob populated by high energetic electrons spanning a narrow range of Lorentz factors, from gamma(min)' = 2 x 10(4) to gamma(max)' = 6 x 10(5).</p

    Monitoring aspirin therapy in children after interventional cardiac catheterization: laboratory measures, dose response, and clinical outcomes

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    Very few studies have investigated dose response of aspirin and agreement of different platelet function assays in children. One hundred five children were studied at baseline and after interventional cardiac catheterization during aspirin treatment and, in cases of aspirin resistance (AR), after dose increase. Results from arachidonate-induced aggregation (AA) were compared with aggregation induced by ADP, PFA-100 closure times (CTs), urinary 11-dehydro-thromboxane B2 (urinary 11-dhTxB2) levels, and Impact-R % surface coverage. Aspirin at 2-5 mg/kg/day inhibited platelet function in a large majority. While 19 % showed bruising and mild epistaxis, no thrombotic complications were recorded. AR was detected by AA in seven children (6.7 %). After dose increase, the majority showed inhibition by aspirin. Infants had higher urinary 11-dhTxB2 baseline levels; this assay showed some correlation with AA. Both assays manifested high sensitivity and specificity for aspirin while inferior results were found for the other assays. With the PFA-100, 15.2 % of patients were found to have AR, but this corresponded to AR by AA in only one of seven children. CONCLUSION: While there was poor agreement among assays, AA and urinary 11-dhTxB2 show good specificity for the monitoring of aspirin therapy in children. Aspirin at 2-5 mg/kg inhibits platelet function; AR in children is rare and can be overcome by dose increase

    Resistance Training as a Tool for Preventing and Treating Musculoskeletal Disorders

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    The aging process is characterized by several physiological, morphological, and psychological alterations that result in a decreased functional and health status throughout the life span. Among these alterations, the loss of muscle mass and strength (sarcopenia) is receiving increased attention because of its association with innumerous age-related disorders, including (but not limited to) osteoporosis, osteoarthritis, low back pain, risk of fall, and disability. Regular participation in resistance training programs can minimize the musculoskeletal alterations that occur during aging, and may contribute to the health and well-being of the older population. Compelling evidence suggest that regular practice of resistance exercise may prevent and control the development of several musculoskeletal chronic diseases. Moreover, resistance training may also improve physical fitness, function, and independence in older people with musculoskeletal disorders, which may result in improved quality of the years lived. In summary, regular participation in resistance training programs plays an important role in aging and may be a preventive and therapeutic tool for several musculoskeletal disorders.Exercise and Chronic Disease Research Laboratory Physical Education Department School of Sciences São Paulo State University-UNESP, Av. Engenheiro Luiz Edmundo Carrijo Coube 14-06Exercise and Chronic Disease Research Laboratory Physical Education Department School of Sciences São Paulo State University-UNESP, Av. Engenheiro Luiz Edmundo Carrijo Coube 14-0

    A review of surface damage/microstructures and their effects on hydrogen/helium retention in tungsten

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