3,404 research outputs found

    Semantic and inferencing abilities in children with communication disorders

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    Background: Semantic and inferencing abilities have not been fully examined in children with communication difficulties. Aims: To investigate the inferential and semantic abilities of children with communication difficulties using newly designed tasks. Methods & Procedures: Children with different types of communication disorder were compared with each other and with three groups of typically developing children: those of the same chronological age and two groups of younger children. In total, 25 children aged 11 years with specific language impairment and 22 children, also 11 years of age, with primary pragmatic difficulties were recruited. Typically developing groups aged 11 (n = 35; age‐match), and those aged 9 (n = 40) and 7 (n = 37; language similar) also participated as comparisons. Outcomes & Results: For Semantic Choices, children with specific language impairment performed significantly more poorly than 9‐ and 11‐year‐olds, whilst the pragmatic difficulties group scored significantly lower than all the typically developing groups. Borderline differences between specific language impairment and pragmatic difficulties groups were found. For inferencing, children with communication impairments performed significantly below the 11‐year‐old peers, but not poorer than 9‐ and 7‐year‐olds, suggesting that this skill is in line with language ability. Six children in the pragmatic difficulties group who met diagnosis for autism performed more poorly than the other two clinical groups on both tasks, but not statistically significantly so. Conclusions: Both tasks were more difficult for those with communication impairments compared with peers. Semantic but not inferencing abilities showed a non‐significant trend for differences between the two clinical groups and children with pragmatic difficulties performed more poorly than all typically developing groups. The tasks may relate to each other in varying ways according to type of communication difficulty

    The Jet in M87 from e-EVN Observations

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    One of the most intriguing open questions of today's astrophysics is the one concerning the location and the mechanisms for the production of MeV, GeV, and TeV gamma-rays in AGN jets. M87 is a privileged laboratory for a detailed study of the properties of jets, owing to its proximity, its massive black hole, and its conspicuous emission at radio wavelengths and above. We started on November 2009 a monitoring program with the e-EVN at 5 GHz, during which two episodes of activity at energy E > 100 GeV have occured. We present here results of these multi-epoch observations. The inner jet and HST-1 are both detected and resolved in our datasets. One of these observations was obtained at the same day of the first high energy flare. A clear change in the proper motion velocity of HST-1 is present at the epoch ~2005.5. In the time range 2003 -- 2005.5 the apparent velocity is subluminal, and superluminal (~ 2.7c) after 2005.5.Comment: Proceedings of the Workshop "Fermi meets Jansky - AGN in Radio and Gamma-Rays", Savolainen, T., Ros, E., Porcas, R.W. & Zensus, J.A. (eds.), MPIfR, Bonn, June 21-23 2010. 4 pages 4 figure

    e-EVN monitoring of M87

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    M87 is a privileged laboratory for a detailed study of the properties of jets, owing to its proximity (D=16.7 Mpc, 1 mas = 0.080 pc), its massive black hole (~6.0 x 10^9M) and its conspicuous emission at radio wavelengths and above. We started on November 2009 a monitoring program with the e-EVN at 5 GHz, in correspondence of the season of Very High Energy (VHE) observations. Indeed, two episodes of VHE activity have been reported in February and April 2010. We present here the main results of these multi-epoch observations: the inner jet and HST-1 are both detected and resolved in our datasets. We study the apparent velocity of HST-1, which seems to be increasing since 2005, and the flux density variability in the inner jet. All in all, the radio counterpart to this year’s VHE event seems to be different from the ones in 2005 and 2008, opening new scenario for the radio-high energy connection

    Oil spill hazard bulletin

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    Dissemination Method: Web Product weblink: https://glamor.sincem.unibo.it The MSFD, the new Directive on Safety of offshore oil and gas operations (2013) and the European Maritime Safety Agency require robust tools for oil spill hazard mapping, from accidental to operational. In this activity WP7 and Marine Core Service products were coupled to Medslik-II oil spill model in order to produce, on request, an Oil Spill Hazard Bulletin based upon the hazard mapping data generated earlier in the project. This report contains background information and some examples of oil spill hazard bulletins for target Atlantic areas. The web-GIS Portal GLAMOR developed for Task 8.4 “Oil spill hazard mapping and disaster risk reduction best practices” is used to create the information content in the requested bulletins. Please note: bulletins are only produced on a request basis

    A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012

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    We report our intensive radio monitoring observations of the jet in M87 with the VLBI Exploration of Radio Astrometry (VERA) and the European VLBI Network (EVN) from February 2011 to October 2012, together with contemporaneous high-energy gamma-ray light curves obtained by the Fermi-LAT. During this period, an elevated level of the M87 flux is reported at VHE gamma rays. We detected a remarkable increase of the radio flux density from the unresolved jet base (radio core) with VERA at 22 and 43GHz coincident with the VHE activity. Meanwhile, we confirmed with EVN at 5GHz that HST-1 (an alternative gamma-ray production candidate site) remained quiescent in terms of its flux density and structure. These results in the radio bands strongly suggest that the VHE gamma-ray activity in 2012 originates in the jet base within 0.03pc or 56 Schwarzschild radii from the central supermassive black hole. We further conducted VERA astrometry for the M87 core during the flaring period, and detected core shifts between 22 and 43GHz. We also discovered a clear frequency-dependent evolution of the radio core flare at 43, 22 and 5GHz; the radio flux density increased more rapidly at higher frequencies with a larger amplitude, and the light curves clearly showed a time-lag between the peaks at 22 and 43GHz. This indicates that a new radio-emitting component was created near the black hole in the period of the VHE event, and then propagated outward with progressively decreasing synchrotron opacity. By combining these results, we estimated an apparent speed of the newborn component, and derived a sub-luminal speed of less than ~0.2c. This value is significantly slower than the super-luminal (~1.1c) features that appeared from the core during the prominent VHE flaring event in 2008, suggesting that the stronger VHE activity can be associated with the production of the higher Lorentz factor jet.Comment: 29 pages, 5 figures, 3 tables, accepted for publication in Ap

    The Role of Antimatter Searches in the Hunt for Supersymmetric Dark Matter

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    We analyze the antimatter yield of supersymmetric (SUSY) models with large neutralino annihilation cross sections. We introduce three benchmark scenarios, respectively featuring bino, wino and higgsino-like lightest neutralinos, and we study in detail the resulting antimatter spectral features. We carry out a systematic and transparent comparison between current and future prospects for direct detection, neutrino telescopes and antimatter searches. We demonstrate that often, in the models we consider, antimatter searches are the only detection channel which already constrains the SUSY parameter space. Particularly large antiprotons fluxes are expected for wino-like lightest neutralinos, while significant antideuteron fluxes result from resonantly annihilating binos. We introduce a simple and general recipe which allows to assess the visibility of a given SUSY model at future antimatter search facilities. We provide evidence that upcoming space-based experiments, like PAMELA or AMS, are going to be, in many cases, the unique open road towards dark matter discovery.Comment: 34 pages, 18 figures; V2: misprints in the labels of fig. 2,3 and 5 correcte

    The Galactic center as a dark matter gamma-ray source

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    Status of the VERITAS Observatory

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    VERITAS, an Imaging Atmospheric Cherenkov Telescope (IACT) system for gammma-ray astronomy in the GeV-TeV range, has recently completed its first season of observations with a full array of four telescopes. A number of astrophysical gamma-ray sources have been detected, both galactic and extragalactic, including sources previously unknown at TeV energies. We describe the status of the array and some highlight results, and assess the technical performance, sensitivity and shower reconstruction capabilities.Comment: Submitted to Proceedings of "4th Heidelberg International Symposium on High Energy Gamma-Ray Astronomy 2008
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