Results from PAMELA, ATIC and FERMI : Pulsars or Dark Matter ?

It is well known that the dark matter dominates the dynamics of galaxies and clusters of galaxies. Its constituents remain a mystery despite an assiduous search for them over the past three decades. Recent results from the satellite-based PAMELA experiment detect an excess in the positron fraction at energies between 10-100 GeV in the secondary cosmic ray spectrum. Other experiments namely ATIC, HESS and FERMI show an excess in the total electron (\ps + \el) spectrum for energies greater 100 GeV. These excesses in the positron fraction as well as the electron spectrum could arise in local astrophysical processes like pulsars, or can be attributed to the annihilation of the dark matter particles. The second possibility gives clues to the possible candidates for the dark matter in galaxies and other astrophysical systems. In this article, we give a report of these exciting developments.Comment: 27 Pages, extensively revised and significantly extended, to appear in Pramana as topical revie

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

Inkorporationsmeßstelle-Inkorporationsüberwachung im 4. Quartal 2002

This is the final version of the article. Available from Lippincott, Williams & Wilkins via the DOI in this record.Objective: To identify the genetic cause of disease in 2 previously unreported families with forms of distal hereditary motor neuropathies (dHMNs). Methods: The first family comprises individuals affected by dHMN type V, which lacks the cardinal clinical feature of vocal cord paralysis characteristic of dHMN-VII observed in the second family. Next-generation sequencing was performed on the proband of each family. Variants were annotated and filtered, initially focusing on genes associated with neuropathy. Candidate variants were further investigated and confirmed by dideoxy sequence analysis and cosegregation studies. Thorough patient phenotyping was completed, comprising clinical history, examination, and neurologic investigation. Results: dHMNs are a heterogeneous group of peripheral motor neuron disorders characterized by length-dependent neuropathy and progressive distal limb muscle weakness and wasting. We previously reported a dominant-negative frameshift mutation located in the concluding exon of theSLC5A7gene encoding the choline transporter (CHT), leading to protein truncation, as the likely cause of dominantly-inherited dHMN-VII in an extended UK family. In this study, our genetic studies identified distinct heterozygous frameshift mutations located in the last coding exon ofSLC5A7, predicted to result in the truncation of the CHT C-terminus, as the likely cause of the condition in each family. Conclusions: This study corroborates C-terminal CHT truncation as a cause of autosomal dominant dHMN, confirming upper limb predominating over lower limb involvement, and broadening the clinical spectrum arising from CHT malfunction.This work was supported by the Association Belge contre les Maladies Neuromusculaire (ABMM)—Aide à la Recherche ASBL and the EU FP7/2007 2013 under grant agreement number 2012—305121 (NEUROMICS), the Medical Research Council (G1002279 to A.H.C.), and the Neurosciences Research Foundation (to A.H.C. and E.L.B.). J.B. is supported by a Senior Clinical Researcher mandate of the Research Fund—Flanders (FWO)