643 research outputs found
Accessing numeric data via flags and tags: A final report on a real world experiment
An experiment is reported which: extended the concepts of data flagging and tagging to the aerospace scientific and technical literature; generated experience with the assignment of data summaries and data terms by documentation specialists; and obtained real world assessments of data summaries and data terms in information products and services. Inclusion of data summaries and data terms improved users' understanding of referenced documents from a subject perspective as well as from a data perspective; furthermore, a radical shift in document ordering behavior occurred during the experiment toward proportionately more requests for data-summarized items
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The identification and psychological treatment of panic disorder in adolescents: a survey of CAMHS clinicians
Background
Panic disorder is experienced by around 1% of adolescents, and has a significant impact on social and academic functioning. Preliminary evidence supports the effectiveness of panic disorder specific treatment in adolescents with panic disorder, however panic disorder may be overlooked in adolescents due to overlapping symptoms with other anxiety disorders and other difficulties being more noticeable to others. The aim of this study was to establish what training National Health Service (NHS) Child and Adolescent Mental Health Services (CAMHS) clinicians have received in psychological therapies and panic disorder and how they identify and treat panic disorder in adolescents.
Method
CAMHS clinicians from a range of professions (n = 427), who were delivering psychological treatments to children and adolescents with anxiety disorders, participated. They completed a cross-sectional, online survey, including a vignette describing an adolescent with panic disorder, and were asked to identify the main diagnosis or presenting problem.
Results
Less than half the clinicians (48.6%) identified panic disorder or panic symptoms as the main presenting problem from the vignette. The majority of clinicians suggested CBT would be their treatment approach. However, few identified an evidence-based treatment protocol for working with young people with panic disorder. Almost half the sample had received no training in cognitive behaviour therapy (CBT) and around a fifth had received no training in delivering psychological treatments.
Conclusions
Only half of CAMHS clinicians identified panic disorder from a vignette and although CBT treatments are widely offered, only a minority of adolescents with panic disorder are receiving treatments developed for, and evaluated with young people with panic disorder. There is a vital need for clinician training, the use of tools that aid identification and the implementation of evidence-based treatments within CAMHS
Sub-Arcsecond Imaging of 3C123:108-GHz Continuum Observations of the Radio Hotspots
We present the results of sub-arcsecond 108 GHz continuum interferometric
observations toward the radio luminous galaxy 3C123. Using multi-array
observations, we utilize the high u,v dynamic range of the BIMA millimeter
array to sample fully spatial scales ranging from 0.5" to 50". This allows us
to make one-to-one comparisons of millimeter-wavelength emission in the radio
lobes and hotspots to VLA centimeter observations at 1.4, 4.9, 8.4, and 15 GHz.
At 108 GHz, the bright, eastern double hotspot in the southern lobe is
resolved. This is only the second time that a multiple hotspot region has been
resolved in the millimeter regime. We model the synchrotron spectra of the
hotspots and radio lobes using simple broken power-law models with high energy
cutoffs, and discuss the hotspot spectra and their implications for models of
multiple hotspot formation.Comment: 16 pages, 3 Figures, ApJ Accepte
The Electron Energy Distribution in the Hotspots of Cygnus A: Filling the Gap with the Spitzer Space Telescope
Here we present Spitzer Space Telescope imaging of Cyg A with the Infrared
Array Camera, resulting in the detection of the high-energy tails or cut-offs
in the synchrotron spectra for all four hotspots of this archetype radio
galaxy. When combined with the other data collected from the literature, our
observations allow for detailed modeling of the broad-band emission for the
brightest spots A and D. We confirm that the X-ray flux detected previously
from these features is consistent with the synchrotron self-Compton radiation
for the magnetic field intensity 170 muG in spot A, and 270 muG in spot D. We
also find that the energy density of the emitting electrons is most likely
larger by a factor of a few than the energy density of the hotspots' magnetic
field. We construct energy spectra of the radiating ultrarelativistic
electrons. We find that for both hotspots A and D these spectra are consistent
with a broken power-law extending from at least 100 MeV up to 100 GeV, and that
the spectral break corresponds almost exactly to the proton rest energy of 1
GeV. We argue that the shape of the electron continuum reflects two different
regimes of the electron acceleration process at mildly relativistic shocks,
rather than resulting from radiative cooling and/or absorption effects. In this
picture the protons' inertia defines the critical energy for the hotspot
electrons above which Fermi-type acceleration processes may play a major role,
but below which the operating acceleration mechanism has to be of a different
type. At energies >100 GeV, the electron spectra cut-off/steepen again, most
likely as a result of spectral aging due to radiative loss effects. We discuss
several implications of the presented analysis for the physics of extragalactic
jets.Comment: 29 pages, 8 figures and 2 tables included. Accepted for publication
in Ap
PILOT: a balloon-borne experiment to measure the polarized FIR emission of dust grains in the interstellar medium
Future cosmology space missions will concentrate on measuring the
polarization of the Cosmic Microwave Background, which potentially carries
invaluable information about the earliest phases of the evolution of our
universe. Such ambitious projects will ultimately be limited by the sensitivity
of the instrument and by the accuracy at which polarized foreground emission
from our own Galaxy can be subtracted out. We present the PILOT balloon project
which will aim at characterizing one of these foreground sources, the
polarization of the dust continuum emission in the diffuse interstellar medium.
The PILOT experiment will also constitute a test-bed for using multiplexed
bolometer arrays for polarization measurements. We present the results of
ground tests obtained just before the first flight of the instrument.Comment: 17 pages, 13 figures. Presented at SPIE, Millimeter, Submillimeter,
and Far-Infrared Detectors and Instrumentation for Astronomy VII. To be
published in Proc. SPIE volume 915
Herschel imaging of the dust in the Helix Nebula (NGC 7293)
In our series of papers presenting the Herschel imaging of evolved planetary
nebulae, we present images of the dust distribution in the Helix nebula (NGC
7293). Images at 70, 160, 250, 350, and 500 micron were obtained with the PACS
and SPIRE instruments on board the Herschel satellite. The broadband maps show
the dust distribution over the main Helix nebula to be clumpy and predominantly
present in the barrel wall. We determined the spectral energy distribution of
the main nebula in a consistent way using Herschel, IRAS, and Planck flux
values. The emissivity index of 0.99 +/- 0.09, in combination with the carbon
rich molecular chemistry of the nebula, indicates that the dust consists mainly
of amorphous carbon. The dust excess emission from the central star disk is
detected at 70 micron and the flux measurement agree with previous measurement.
We present the temperature and dust column density maps. The total dust mass
across the Helix nebula (without its halo) is determined to be 0.0035 solar
mass at a distance of 216 pc. The temperature map shows dust temperatures
between 22 and 42 K, which is similar to the kinetic temperature of the
molecular gas, strengthening the fact that the dust and gas co-exist in high
density clumps. Archived images are used to compare the location of the dust
emission in the far infrared (Herschel) with the ionized (GALEX, Hbeta) and
molecular hydrogen component. The different emission components are consistent
with the Helix consisting of a thick walled barrel-like structure inclined to
the line of sight. The radiation field decreases rapidly through the barrel
wall.Comment: 8 pages, 9 figures, revised version A&A in pres
X-Rays from NGC 3256: High-Energy Emission in Starburst Galaxies and Their Contribution to the Cosmic X-Ray Background
The infrared-luminous galaxy NGC3256 is a classic example of a merger induced
nuclear starburst system. We find here that it is the most X-ray luminous
star-forming galaxy yet detected (~10^42 ergs/s). Long-slit optical
spectroscopy and a deep, high-resolution ROSAT X-ray image show that the
starburst is driving a "superwind" which accounts for ~20% of the observed soft
(kT~0.3 keV) X-ray emission. Our model for the broadband X-ray emission of
NGC3256 contains two additional components: a warm thermal plasma (kT~0.8 keV)
associated with the central starburst, and a hard power-law component with an
energy index of ~0.7. We find that the input of mechanical energy from the
starburst is more than sufficient to sustain the observed level of emission. We
also examine possible origins for the power-law component, concluding that
neither a buried AGN nor the expected population of high-mass X-ray binaries
can account for this emission. Inverse-Compton scattering, involving the
galaxy's copious flux of infrared photons and the relativistic electrons
produced by supernovae, is likely to make a substantial contribution to the
hard X-ray flux. Such a model is consistent with the observed radio and IR
fluxes and the radio and X-ray spectral indices. We explore the role of
X-ray-luminous starbursts in the production of the cosmic X-ray background
radiation. The number counts and spectral index distribution of the faint radio
source population, thought to be dominated by star-forming galaxies, suggest
that a significant fraction of the hard X-ray background could arise from
starbursts at moderate redshift.Comment: 31 pages (tex, epsf), 8 figures (postscript files), accepted for
publication in Part 1 of The Astrophysical Journa
Mutations of the BRAF gene in human cancer
Cancers arise owing to the accumulation of mutations in critical genes that alter normal programmes of cell proliferation, differentiation and death. As the first stage of a systematic genome-wide screen for these genes, we have prioritized for analysis signalling pathways in which at least one gene is mutated in human cancer. The RAS RAF MEK ERK MAP kinase pathway mediates cellular responses to growth signals. RAS is mutated to an oncogenic form in about 15% of human cancer. The three RAF genes code for cytoplasmic serine/threonine kinases that are regulated by binding RAS. Here we report BRAF somatic missense mutations in 66% of malignant melanomas and at lower frequency in a wide range of human cancers. All mutations are within the kinase domain, with a single substitution (V599E) accounting for 80%. Mutated BRAF proteins have elevated kinase activity and are transforming in NIH3T3 cells. Furthermore, RAS function is not required for the growth of cancer cell lines with the V599E mutation. As BRAF is a serine/threonine kinase that is commonly activated by somatic point mutation in human cancer, it may provide new therapeutic opportunities in malignant melanoma
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