12 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

    Cancer in Indigenous Australians: a review

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    OBJECTIVES: To summarize for the first time evidence of the impact of cancer on Indigenous Australians. METHODS: Medline search of peer-reviewed scientific journals, and extensive search of reports of government agencies, publications of cancer registries and non-government organizations, and other non-peer-reviewed sources. RESULTS: Indigenous Australians have much higher incidence rates than other Australians of cancers of the lung, liver, and cervix; but much lower rates of cancers of the breast, colon and rectum, prostate, melanoma of skin, and lymphoma. Some of these differences can be explained, in part at least, by differences in risk factor prevalence. Indigenous Australians also have higher mortality and lower survival from cancer as a whole than other Australians. More advanced disease at diagnosis, and possibly poorer treatment, are partly responsible for these differences, but other factors may also be involved. CONCLUSIONS: Less accessible and less effective health programs are as great a problem for cancer control as for other aspects of Indigenous health in Australia. Major improvements in preventive services, screening, primary care, and specialist treatment services are required to reduce cancer incidence and improve cancer outcomes for Australia's Indigenous peopl

    Theory of Circular Dichroism of Proteins

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    Theoretical Foundations to Guide Mindfulness Meditation: A Path to Wisdom

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    Turns

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    Effect of Three Different Mouthrinses on Microleakage of Composite Resin Restorations with Two Adhesive Systems after Bleaching with 10% Carbamide Peroxide

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    Sunflower and climate change: Possibilities of adaptation through breeding and genomic selection

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    Due to its ability to grow in different agroecological conditions and its moderate drought tolerance, sunflower may become the oil crop of preference in the future, especially in the light of global environmental changes. In the field conditions, sunflower crop is often simultaneously challenged by different biotic and abiotic stresses, and understanding the shared mechanisms contributing to two or more stresses occurring individually or simultaneously is important to improve crop productivity under foreseeable complex stress situations. Exploitation of the available plant genetic resources in combination with the use of modern molecular tools for genome-wide association studies (GWAS) and application of genomic selection (GS) could lead to considerable improvements in sunflower, especially with regard to different stresses and better adaptation to the climate change. In this chapter we present a review of climate-smart (CS) traits and respective genetic resources and tools for their introduction into the cultivated sunflower, thus making it the oil crop resilient to the extreme climatic conditions and well-known and emerging pests and diseases. © Springer Nature Switzerland AG 2019
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