Multi-messenger observations of a binary neutron star merger

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

Localization and broadband follow-up of the gravitational-wave transient GW150914

A gravitational-wave (GW) transient was identified in data recorded by the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) detectors on 2015 September 14. The event, initially designated G184098 and later given the name GW150914, is described in detail elsewhere. By prior arrangement, preliminary estimates of the time, significance, and sky location of the event were shared with 63 teams of observers covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths with ground- and space-based facilities. In this Letter we describe the low-latency analysis of the GW data and present the sky localization of the first observed compact binary merger. We summarize the follow-up observations reported by 25 teams via private Gamma-ray Coordinates Network circulars, giving an overview of the participating facilities, the GW sky localization coverage, the timeline, and depth of the observations. As this event turned out to be a binary black hole merger, there is little expectation of a detectable electromagnetic (EM) signature. Nevertheless, this first broadband campaign to search for a counterpart of an Advanced LIGO source represents a milestone and highlights the broad capabilities of the transient astronomy community and the observing strategies that have been developed to pursue neutron star binary merger events. Detailed investigations of the EM data and results of the EM follow-up campaign are being disseminated in papers by the individual teams

15N-Labelled proteins by cell-free protein synthesis. Strategies for high-throughput NMR studies of proteins and protein-ligand complexes

Abstract [15N]-heteronuclear single quantum coherence (HSQC) spectra provide a readily accessible fingerprint of [15N]-labelled proteins, where the backbone amide group of each nonproline amino acid residue contributes a single cross-peak. Cell-free protein synthesis offers a fast and economical route to enhance the information content of [15N]-HSQC spectra by amino acid type selective [15N]-labelling. The samples can be measured without chromatographic protein purification, dilution of isotopes by transaminase activities are suppressed, and a combinatorial isotope labelling scheme can be adopted that combines reduced spectral overlap with a minimum number of samples for the identification of all [15N]-HSQC cross-peaks by amino acid residue type. These techniques are particularly powerful for tracking [15N]-HSQC cross-peaks after titration with unlabelled ligand molecules or macromolecular binding partners. In particular, combinatorial isotope labelling can provide complete cross-peak identification by amino acid type in 24 h, including protein production and NMR measurement

Disfonias: relação S/Z e tipos de voz Dysphonias: S/Z ratio and types of voice

OBJETIVO: verificar o resultado da relação s/z e do tipo de voz em pacientes com diagnóstico de disfonias orgânico-funcionais (DOF) e disfonias funcionais por uso incorreto da voz (DFUIV), bem como a ocorrência das diferentes patologias dentro das DOF. MÉTODOS: 70 indivíduos, de ambos os sexos, entre cinco e 65 anos de idade, atendidos numa clínica-escola, cadastrados em Banco de Dados, entre 1998 e 2006, com DOF e DFUIV, ambos classificados em três subgrupos: casos em que a relação s/z indicava hipercontração, normalidade, e falta de coaptação das pregas vocais durante a fonação. Os tipos de voz foram classificados conforme a ocorrência em: sem alteração; ruidosa; ruidosa, comprimida e/ou apresentando alteração de f0h; ruidosa e/ou apresentando alteração de f0h; e comprimida. RESULTADOS: ocorrência significativa de DOF e de DOF com nódulos vocais; nas DOF e DFUIV, ocorrência significante de relação s/z normal com tempos isolados de /s/ e /z/ abaixo do normal e voz ruidosa. CONCLUSÕES: O resultado da relação s/z foi estatisticamente significativo a favor da faixa de normalidade estabelecida, tanto nos pacientes com diagnóstico de DOF, quanto naqueles com DFUIV, sendo que, em ambos os grupos de pacientes, a voz ruidosa foi a mais freqüente. Dentro das DOF, os nódulos vocais foram significativamente mais freqüentes do que as demais patologias.<br>PURPOSE: to check the result of s/z ratio and types of voice in patients with diagnosis of organic-functional dysphonias (DOF) and functional dysphonias by incorrect use of voice (DFUIV), as well as the occurrence of the various pathologies within the DOF. METHODS: 70 subjects of both genders, between 5 and 65 years old, seen in a clinic-school, registered in a data bank from 1998 to 2006, with DOF and DFUIV, both classified in three sub-groups: cases in which the s/z ratio indicated hypercontraction, normality and lack of coaptation of the vocal folds during phonation. According to the occurrence, the types of voice were classified in: without alteration; noisy; compressed and/or presenting alteration of f0h; noisy and/or with alteration of f0h; and compressed. RESULTS: significant presence of DOF and DOF with vocal nodules; in DOF and DFUIV, significant presence of the normal s/z ratio with isolated times of /s/ and /z/ below the normal and noisy voice. CONCLUSIONS: the result of the s/z ratio was statistically significant in favor of the range of established normalcy, both in patients with a diagnosis of DOF, as well as with those with DFUIV, and that, in both groups of patients, the noisy voice was the most frequent. Within the DOF, the vocal nodules were significantly more frequent than the other pathologies