301 research outputs found

    A luminous blue kilonova and an off-axis jet from a compact binary merger at z=0.1341

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    The recent discovery of a faint gamma-ray burst (GRB) coincident with the gravitational wave (GW) event GW 170817 revealed the existence of a population of low-luminosity short duration gamma-ray transients produced by neutron star mergers in the nearby Universe. These events could be routinely detected by existing gamma-ray monitors, yet previous observations failed to identify them without the aid of GW triggers. Here we show that GRB150101B was an analogue of GRB170817A located at a cosmological distance. GRB 150101B was a faint short duration GRB characterized by a bright optical counterpart and a long-lived X-ray afterglow. These properties are unusual for standard short GRBs and are instead consistent with an explosion viewed off-axis: the optical light is produced by a luminous kilonova component, while the observed X-rays trace the GRB afterglow viewed at an angle of ~13 degrees. Our findings suggest that these properties could be common among future electromagnetic counterparts of GW sources.Comment: 28 pages, 8 figures, 2 tables. Accepted for publicatio

    Synthesis and Complexing Properties of p-Toluensulfonylamido and Phosphorylamido Derivatives of Second-Generation Hyperbranched Polyester

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    © 2018, Pleiades Publishing, Ltd. Hyperbranched polyesters containing terminal p-toluenesulfonylamido and diethoxyphosphorylamido groups have been synthesized, and their complexes with copper(II) and cobalt(II) ions have been prepared. The thermal stability of the ligands and their metal complexes has been studied by differential scanning calorimetry

    Development and Operation of the Microshutter Array System

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    The microshutter array (MSA) is a key component in the James Webb Space Telescope Near Infrared Spectrometer (NIRSpec) instrument. The James Webb Space Telescope is the next generation of a space-borne astronomy platform that is scheduled to be launched in 2013. However, in order to effectively operate the array and meet the severe operational requirements associated with a space flight mission has placed enormous constraints on the microshutter array subsystem. This paper will present an overview and description of the entire microshutter subsystem including the microshutter array, the hybridized array assembly, the integrated CMOS electronics, mechanical mounting module and the test methodology and performance of the fully assembled microshutter subsystem. The NIRSpec is a European Space Agency (ESA) instrument requiring four fully assembled microshutter arrays, or quads, which are independently addressed to allow for the imaging of selected celestial objects onto the two 4 mega pixel IR detectors. Each microshutter array must have no more than approx.8 shutters which are failed in the open mode (depending on how many are failed closed) out of the 62,415 (365x171) total number of shutters per array. The driving science requirement is to be able to select up to 100 objects at a time to be spectrally imaged at the focal plane. The spectrum is dispersed in the direction of the 171 shutters so if there is an unwanted open shutter in that row the light from an object passing through that failed open shutter will corrupt the spectrum from the intended object

    Synthesis and spectral characteristics of 2,2-bis(hydroxymethyl)propionic acid derivatives as model compounds for the estimation of properties of modified hyperbranched polyesters polyols

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    © 2015 Pleiades Publishing, Ltd. New amino and carboxy derivatives of methyl 2,2-bis(hydroxymethyl)propionate have been synthesized as models of terminal fragments of hyperbranched polyester polyamines and polyesters polycarboxylic acids, and their spectral characteristics have been studied

    Paleogenomics of the Plague Agent and Prospects for Paleogenomic Studies in Russia

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    The review contains information on paleogenomic studies of the plague pathogen, Yersinia pestis, covering the prehistoric epoch, the periods of the first and second plague pandemics, epidemics and outbreaks of plague of the late XIX–XX centuries. We have summarized the data on the reconstruction of ancient Y. pestis genomes of the Late Neolithic, Bronze and Iron Ages, the Justinian Plague epidemic of the first plague pandemic, the Black Death epidemic and the subsequent epidemics of the second plague pandemic of the XIV–XVIII centuries, as well as on tracing the pathways of plague propagation waves in Eurasia and the course of plague agent evolution with the formation of a vector-borne transmission route with the help of arthropods. We present the results of our own research of Y. pestis genomes from the key sites of formation of etiological agents of the first and second plague pandemics in the Tien Shan Mountains, historical outbreaks in the Northern and North-Western Caspian sea region and other regions of Russia and adjoining countries in the late XIX–XX centuries. The paper discusses the areas of the Caucasus, Crimea, Northern Caspian, Siberia, and Tien Shan in the territory of Russia and neighboring states that are promising for national paleogenomic studies of plague

    Historical and Modern Classifications of the Plague Agent

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    The review presents the data on domestic and foreign phenotypic classifications of Yersinia pestis strains developed in the XX century; genetic classifications of the XXI century; as well as on the genealogy of ancient strains of the plague microbe, reconstructed using paleogenomic technologies. Since the discovery of the plague agent in 1894, many classifications were created that corresponded to the level of development of microbiology at that time. The intraspecific classification schemes of the XX century were based on three principles: phenotypic differences between strains, features of the species composition of carriers, and geographical affiliation. With the development of molecular microbiology early on in the XXI century, a genetic nomenclature of the branches of the pathogen evolution was developed and a number of classifications based on the analysis of the population structure of Y. pestis were created. Through the prism of the genetic diversity of Y. pestis strains from natural plague foci in Russia, near and far abroad countries, an improved classification with a division into seven subspecies has been developed: pestis, tibetica, caucasica, qinghaica, angolica, central asiatica, ulegeica, which allocates the subspecies according to the phylogenetic principle and epidemic significance. With the advancements in paleomicrobiology, prehistoric lineages of evolution have been included in the genealogy of Y. pestis, which expand the data on the intraspecific diversity of the plague microbe

    Synthetic Biology: Risks and Prospects

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    New area of biological studies that goes under general name of “synthetic biology” is a next step in the development of gene engineering associated with design and construction of unique biological systems with “preset” functions and properties, having no natural analogues. Nowadays synthetic biology is a source of innovations that offer solution to a number of global problems facing the humanity, including production of artificial genome-based multi-diagnostic panels, medicinal preparations, synthetic vaccine, etc. The process of unnatural life form creation requires conduction of monitoring both on the international and national scales using advanced system of biological risk assessment
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