3,540 research outputs found
Semantic and inferencing abilities in children with communication disorders
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
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
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
Endothelial cells, endoplasmic reticulum stress and oxysterols
Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell viability and are involved in several diseases, including atherosclerosis. Mounting evidence linked the atherosclerosis to endothelium dysfunction; in fact, the endothelium regulates the vascular system with roles in processes such as hemostasis, cell cholesterol, hormone trafficking, signal transduction and inflammation. Several papers shed light the ability of oxysterols to induce apoptosis in different cell lines including endothelial cells. Apoptotic endothelial cell and endothelial denudation may constitute a critical step in the transition to plaque erosion and vessel thrombosis, so preventing the endothelial damaged has garnered considerable attention as a novel means of treating atherosclerosis. Endoplasmic reticulum (ER) is the site where the proteins are synthetized and folded and is necessary for most cellular activity; perturbations of ER homeostasis leads to a condition known as endoplasmic reticulum stress. This condition evokes the unfolded protein response (UPR) an adaptive pathway that aims to restore ER homeostasis. Mounting evidence suggests that chronic activation of UPR leads to cell dysfunction and death and recently has been implicated in pathogenesis of endothelial dysfunction. Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation, maintaining basal levels of autophagic activity it is critical for cell survival. Several evidence suggests that persistent ER stress often results in stimulation of autophagic activities, likely as a compensatory mechanism to relieve ER stress and consequently cell death. In this review, we summarize evidence for the effect of oxysterols on endothelial cells, especially focusing on oxysterols-mediated induction of endoplasmic reticulum stress
A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012
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
SEEMP: A marketplace for the Labour Market
Employment Services are an important topic in the agenda of local governments and in the EU due to their social implications, such as sustainability, workforce mobility, workers’ re-qualification paths, training for fresh graduates and students. Many administrations started their own E-Government projects whose imitations emerge as the demand of workers mobility increases. The SEEMP system presented in this paper overcomes this issue in different ways: starting bilateral communications with near-border similar offices, building a federation of the local employment services, and merging isolate trials. The SEEMP approach relies on a distributed semantic service oriented infrastructure able to federate local projects, in order to create geographically aggregated services for employment by leveraging existing local ones. The social and technical aspects of the SEEMP project are presented, showing how the SEEMP system is integrated with National level systems
The Role of Antimatter Searches in the Hunt for Supersymmetric Dark Matter
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
Beyond the required LISA free-fall performance: new LISA pathfinder results down to 20 μHz
In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05) fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10 fm s^{-2}/sqrt[Hz] at 20 μHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency
Sub-femto-g free fall for space-based gravitational wave observatories: LISA pathfinder results
We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2 ± 0.1 fm s−2/√Hz or (0.54 ± 0.01) × 10−15 g/√Hz, with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8 ± 0.3) fm/√Hz, about 2 orders of magnitude better than requirements. At f ≤ 0.5 mHz we observe a low-frequency tail that stays below 12 fm s−2/√Hz down to 0.1 mHz. This performance would allow for a space-based gravitational wave
observatory with a sensitivity close to what was originally foreseen for LISA
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