A fast radio burst localized to a massive galaxy.

Intense, millisecond-duration bursts of radio waves (named fast radio bursts) have been detected from beyond the Milky Way1. Their dispersion measures-which are greater than would be expected if they had propagated only through the interstellar medium of the Milky Way-indicate extragalactic origins and imply contributions from the intergalactic medium and perhaps from other galaxies2. Although several theories exist regarding the sources of these fast radio bursts, their intensities, durations and temporal structures suggest coherent emission from highly magnetized plasma3,4. Two of these bursts have been observed to repeat5,6, and one repeater (FRB 121102) has been localized to the largest star-forming region of a dwarf galaxy at a cosmological redshift of 0.19 (refs. 7-9). However, the host galaxies and distances of the hitherto non-repeating fast radio bursts are yet to be identified. Unlike repeating sources, these events must be observed with an interferometer that has sufficient spatial resolution for arcsecond localization at the time of discovery. Here we report the localization of a fast radio burst (FRB 190523) to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66. This galaxy is different from the host of FRB 121102, as it is a thousand times more massive, with a specific star-formation rate (the star-formation rate divided by the mass) a hundred times smaller.

Efficacy of high dose of recombinant alpha 2b interferon on long term response in chronic hepatitis C and cirrhosis: prospective randomized multicentre study.

BACKGROUND/AIMS: The long-term response to alpha-Interferon in HCV-related chronic liver diseases is disappointing. A randomized controlled trial was conducted to investigate: 1) if doubling the standard regimen of 3 MU recombinant alpha 2b-interferon thrice weekly for one year could improve the long-term response, and 2) the efficacy of these two schedules in cirrhotic patients. PATIENTS AND METHODS: A series of 80 anti-HCV positive patients with biopsy proven liver disease (52 chronic hepatitis and 28 cirrhosis) were randomized to receive either 3 MU or 6 MU alpha 2b-interferon. RESULTS: Based on "intention-to-treat analysis", 38% in the 3 MU group and 53% in the 6 MU group had end-of-treatment response. After 24 months, 18% had long-term response: 5% in 3 MU group and 30% in 6 MU group (p < 0.008). HCV genotype had no influence on the response rate. Thirty-eight percent of the cirrhotics treated with 6 MU had long-term response, while none of those treated with 3 MU had long-term response (difference 38%; 95% confidence internal 10%-67%; p = 0.03). At the end of treatment, 38% of patients lost HCV-RNA. After 24 months only 19% remained HCV-RNA negative: 12 patients (31%) in the 6 MU group and 2 (6%) in the 3 MU group (p < 0.05). CONCLUSIONS: 6 MU of alpha 2b-interferon thrice weekly for 12 months is significantly better than 3 MU in inducing a long-term response and permanent loss of HCV-RNA. This result is particularly striking in the subgroup of cirrhotics.

Overview and initial results of the very long baseline interferometry space observatory programme

High angular resolution images of extragalactic radio sources are being made with the Highly Advanced Laboratory for Communications and Astronomy (HALCA) satellite and ground-based radio telescopes as part of the Very Long Baseline Interferometry (VLBI) Space Observatory Programme (VSOP). VSOP observations at 1.6 and 5 gigahertz of the milli-arc-second-scale structure of radio quasars enable the quasar core size and the corresponding brightness temperature to be determined, and they enable the motions of jet components that are close to the core to be studied. Here, VSOP images of the gamma-ray source 1156+295, the quasar 1548+056, the ultraluminous quasar 0014+813, and the superluminal quasar 0212+735 are presented and discussed.