Diffuse radio emission in the merging cluster MACS J0717.5+3745: the discovery of the most powerful radio halo

Hierarchical models of structure formation predict that galaxy clusters grow via mergers of smaller clusters and galaxy groups, as well as through continuous accretion of gas. MACS J0717.5+3745 is an X-ray luminous and complex merging cluster, located at a redshift of 0.55. Here we present Giant Metrewave Radio Telescope (GMRT) radio observations at 610 MHz of this cluster. The main aim of the observations is to search for diffuse radio emission within the galaxy cluster MACS J0717.5+3745 related to the ongoing merger. These GMRT observations are complemented by Very Large Array (VLA) archival observations at 1.4, 4.9 and 8.5 GHz. We have discovered a radio halo in the cluster MACS J0717.5+3745 with a size of about 1.2 Mpc. The radio power P_1.4 GHz is 5 x 10^25 W/Hz, which makes it the most powerful radio halo known till date. A 700 kpc radio structure, which we classify as a radio relic, is located in between the merging substructures of the system. The location of this relic roughly coincides with regions of the intra-cluster medium (ICM) that have a significant enhancement in temperature as shown by Chandra. The major axis of the relic is also roughly perpendicular to the merger axis. This shows that the relic might be the result of a merger-related shock wave, where particles are accelerated via the diffuse shock acceleration (DSA) mechanism. Alternatively, the relic might trace an accretion shock of a large-scale galaxy filament to the south-west. The global spectral index of radio emission within the cluster is found to be -1.24 +/-0.05 between 4.9 GHz and 610 MHz. We derive a value of 5.8 microGauss for the equipartition magnetic field strength at the location of the radio halo. [abridged].Comment: 8 pages, 9 figures, accepted for publication in A&A on August 3, 200

Particle Acceleration on Megaparsec Scales in a Merging Galaxy Cluster

Galaxy clusters form through a sequence of mergers of smaller galaxy clusters and groups. Models of diffusive shock acceleration (DSA) suggest that in shocks that occur during cluster mergers, particles are accelerated to relativistic energies, similar to supernova remnants. Together with magnetic fields these particles emit synchrotron radiation and may form so-called radio relics. Here we report the detection of a radio relic for which we find highly aligned magnetic fields, a strong spectral index gradient, and a narrow relic width, giving a measure of the magnetic field in an unexplored site of the universe. Our observations prove that DSA also operates on scales much larger than in supernova remnants and that shocks in galaxy clusters are capable of producing extremely energetic cosmic rays.Comment: Published in Science Express on 23 September 2010, 6 figures, Supporting Online Material included. This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science, volume 330, 15 October 201

Electron microscopic and biochemical characterization of Fraction 1 protein

High resolution electron microscopy of Fraction I protein from plant leave

The provision of education and training for healthcare professionals through the medium of the internet

This paper describes a new initiative to provide Internet based courses to student and professional occupational therapists in four centres in the UK, Belgium the Netherlands and Sweden. The basis of this collaborative Occupational Therapy Internet School (OTIS) is the concept of the “Virtual College”. This comprises the design and implementation of a sophisticated Internet-based system through which courses can be managed, prepared and delivered online in an effective fashion, and where students can communicate both with the staff and their peers. The aim is to support and facilitate the whole range of educational activities within a remote electronic environment. A major feature of the course organisation is the adoption of a problem-based approach in which students will collaborate internationally to propose effective intervention in given case study scenarios. The paper outlines the rationale for OTIS, the content and structure of the courseware, the technical specification of the system and evaluation criteria. In addition to the more conventional web-based learning facilities generally offered, a number of agent-based approaches are being adopted to assist in the management of the course by ensuring the proper delivery of course materials and to assist the functioning of project groups. </p

Evolocumab's Long-Term Mortality Risk Unclear Due to Shortened Follow-Up of FOURIER

The FOURIER (Further Cardiovascular Outcomes Research with PCSK9 inhibition in Subjects with Elevated Risk) trial was conducted to study cardiovascular outcomes of treatment with evolocumab. The trial was terminated after a median follow-up of 2.2 years instead of the planned 3.6 years. We question this decision. According to the investigators, the event rate was 50% higher than expected. However, the accrued number of key secondary events (1829) was only 12% higher than the targeted number (1630). Also, around one-third of the events consisted of non-atherosclerotic myocardial infarctions, hemorrhagic strokes, and cardiovascular deaths unrelated to myocardial infarction or stroke. Moreover, halfway through the trial, the sample size changed from 22,500 to 27,500, even though the accrual of the targeted number of events was on track. Finally, the rate of all-cause mortality had started to diverge in favor of placebo after 2 years of follow-up. It was 4.8% for evolocumab and 4.3% for placebo in participants with > 2.5 years of follow-up. A long-term follow-up would have yielded more events and thus more power to evaluate the effect of evolocumab on all-cause mortality. We conclude that adaptive designs carry a recognized risk of false-positive efficacy results, but the risk of false-negative safety results is underappreciated

Stikstof- en fosfaatexcretie van gangbaar en biologisch gehouden landbouwhuisdieren. Herziening excretieforfaits Meststoffenwet 2015.

Om de hoeveelheden stikstof en fosfaat in dierlijke mest te berekenen die op een bedrijf worden geproduceerd, kunnen veehouders gebruik maken van de zogenoemde excretieforfaits in de Uitvoeringsregeling van de Meststoffenwet. Deze excretieforfaits geven weer hoeveel stikstof en fosfaat in mest per dier en per diercategorie op jaarbasis wordt geproduceerd. Op verzoek van het Ministerie van Economische Zaken heeft de Commissie Deskundigen Meststoffenwet (CDM) een voorstel gemaakt voor herziening van de diercategorieën en de excretieforfaits van de Uitvoeringsregeling Meststoffenwet. Dit rapport beschrijft het voorstel voor de herziening van de excretieforfaits voor de eerder aangepaste lijst vandiercategorieën. Bij de excretieforfaits wordt onderscheid gemaakt tussen gangbare en biologische dierhouderijsystemen. De bruto stikstof- en fosfaatexcreties voor dieren in gangbare dierhouderijsystemen zijn gebaseerd op de resultaten van de Werkgroep Uniformering berekening Mest- en mineralencijfers (WUM) voor de jaren 2011, 2012 en 2013. De WUM berekent per jaar de gemiddelde excreties per diercategorie op basis van statistieken over veevoergebruik en dierlijke productie. De bruto stikstof- en fosfaatexcreties voor dieren in biologische dierhouderijsystemen zijn gebaseerd op die van gangbare dierhouderijsystemen en een diercategorie-specifieke correctiefactor. De bruto stikstofexcreties zijn vervolgens gecorrigeerd voor gasvormige stikstofverliezen op basis van gegevens van de werkgroep National Emission Model for Agriculture (NEMA)

De ballingschap van de Byzantijnse tekst

For more than a century the Byzantine Text-type has been in exile. Mean­while, endeavours to re-establish the original text of the New Testament have not succeeded. The question thus arises whether it is necessary to keep the banished text silent forever. This article describes the revival of a plea for listening also to the Byzantine Text-type in restoring the ancient text. Arguments against this text in exile are evaluated. Two points in favour of the banished text are introduced: 1. Its readings are nearly always supported by one or more of the other text-types: why should the accom­plices go scot-free? 2. Its readings have more than once the flavour of authenticity: why should we leave innocent readings in exile