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

A KARYOMETRIC STUDY OF HEAT-SHOCKED HELA-CELLS

HeLa cells exposed to heat shock at temperatures of 40-degrees-C and 43-degrees-C for 1 hour and also cells 4h after returning to control conditions (37-degrees-C) were studied comparatively with respect to nuclear and nucleolar sizes, using karyometric procedures. Some alterations especially involving nucleolar areas were found to be promoted by the shock, though mostly detectable during the post-shock period held at control temperature. These alterations when elicited by the shock at 43-degrees-C were assumed to be associated with transcriptional activities involved in recovery of the ordinary cellular activities, whereas those related to the shock at 40-degrees-C were suggested to be due to karyoskeletal proteins appearing late with the stress and which could be mechanically restraining the nucleolar area increase. These proteins also appear in the HeLa cells exposed to the heat shock at 43-degrees-C and equally seem to affect the increase in nucleolar area in comparison to nuclear area, however they are disassembled when the cells are returned to control temperature.16116117

HB LEPORE(BALTIMORE) (DELTA-50SER BETA-86ALA) IDENTIFIED BY DNA ANALYSIS IN A BRAZILIAN FAMILY

Genomic DNA from two Brazilian hemoglobin (Hb) Lepore heterozygotes of Italian ancestry have been studied in order to identify the Hb Lepore type and to sequence the breakpoint region. The two genes were sequenced after PCR amplification and had the delta globin sequence up to exon 2 codon 68 while the first specific base for the beta globin gene was at codon 86 of the second exon; between the two ends, they had 51 base pairs in common with the delta and beta globin genes. These data indicate that the mutation was of the Hb Lepore(Baltimore) type. The Lepore chromosome haplotype was different from that previously described in members of a Spanish family with Hb Lepore(Baltimore). These data suggest that independent mutations have given rise to Hb Lepore(Baltimore) in different regions of the world.9117

Hb Camperdown [alpha(2)beta(2)104(G6)Arg->Ser] identified by DNA analysis in a Brazilian family

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