14 research outputs found

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Influence of footwear choice, velocity and surfaces on tibial accelerations experienced by field hockey participants during running

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    Field hockey is a physically demanding sport, exposing participants to potential overuse injuries linked to high levels of impact shock. This study evaluated the influence of footwear, surface and running velocity on impact shock in field hockey participants. Nine elite university male field hockey participants (age 21 ± 1.69 years, height 175.75 ± 6.56 cm and mass 78.13 ± 12.11 kg) volunteered for this study. A skin-mounted accelerometer was used to measure tibial impact shock during forward running at 3.3 and 5.0 m s -1 on concrete and a field hockey-specific synthetic sports surface (SSS), in a range of shoes (n = 5) typically worn by field hockey participants. A significant effect was found for surface and velocity. No significant differences were found between footwear conditions. The study concluded that reducing running velocity and participating in all field hockey activities on a suitable SSS may reduce the occurrence of injuries linked to impact shock in a field hockey population. © 2012 Copyright Taylor and Francis Group, LLC

    Nutrients: the environmental regulation of cardiovascular gene expression

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    The complexity of nutrient–gene interactions has led to the development of a new branch in the nutrition sciences, the nutrigenomics. The individual susceptibility to nutrients based on environment → genotype → phenotype interplay makes this new research field extremely promising although complex. In this review, we highlight and examine recent findings and the most relevant hypotheses on the role of the diet in the onset and progression of cardiovascular diseases. The effect of unbalanced diets on the cardiovascular system is considered one of the most important risk factors both for ischemic and degenerative myocardial pathologies. The concept that nutrigenomics could help in improving public and personal health is becoming tangible indicating future directions for basic and applied research in the pathophysiology of cardiovascular disease
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