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Complete recovery from anxiety disorders following Cognitive Behavioural Therapy in children and adolescents: a meta analysis
Cognitive Behavior Therapy (CBT) is a well-established treatment for childhood anxiety disorders. Meta-analyses have concluded that approximately 60% of children recover following treatment, however these include studies using a broad range of diagnostic indices to assess outcomes including whether children are free of the one anxiety disorder that causes most interference (i.e. the primary anxiety disorder) or whether children are free of all anxiety disorders. We conducted a meta-analysis to establish the efficacy of CBT in terms of absence of all anxiety disorders. Where available we compared this rate to outcomes based on absence of primary disorder. Of 56 published randomized controlled trials, 19 provided data on recovery from all anxiety disorders (n = 635 CBT, n = 450 control participants). There was significant heterogeneity across those studies with available data and full recovery rates varied from 47.6 to 66.4% among children without autistic spectrum conditions (ASC) and 12.2 to 36.7% for children with ASC following treatment, compared to up to 20.6% and 21.3% recovery in waitlist and active treatment comparisons. The lack of consistency in diagnostic outcomes highlights the urgent need for consensus on reporting in future RCTs of childhood anxiety disorders for the meaningful synthesis of data going forwards
A quantum study of multi-bit phase coding for optical storage
We propose a scheme which encodes information in both the longitudinal and
spatial transverse phases of a continuous-wave optical beam. A split
detector-based interferometric scheme is then introduced to optimally detect
both encoded phase signals. In contrast to present-day optical storage devices,
our phase coding scheme has an information storage capacity which scales with
the power of the read-out optical beam. We analyse the maximum number of
encoding possibilities at the shot noise limit. In addition, we show that using
squeezed light, the shot noise limit can be overcome and the number of encoding
possibilities increased. We discuss a possible application of our phase coding
scheme for increasing the capacities of optical storage devices.Comment: 8 pages, 7 figures (Please email author for a PDF file if the
manuscript does not turn out properly
Quantum limited particle sensing in optical tweezers
Particle sensing in optical tweezers systems provides information on the
position, velocity and force of the specimen particles. The conventional
quadrant detection scheme is applied ubiquitously in optical tweezers
experiments to quantify these parameters. In this paper we show that quadrant
detection is non-optimal for particle sensing in optical tweezers and propose
an alternative optimal particle sensing scheme based on spatial homodyne
detection. A formalism for particle sensing in terms of transverse spatial
modes is developed and numerical simulations of the efficacy of both quadrant
and spatial homodyne detection are shown. We demonstrate that an order of
magnitude improvement in particle sensing sensitivity can be achieved using
spatial homodyne over quadrant detection.Comment: Submitted to Biophys
New insights into ultraluminous X-ray sources from deep XMM-Newton observations
The controversy over whether ultraluminous X-ray sources (ULXs) contain a new
intermediate-mass class of black holes (IMBHs) remains unresolved. We present
new analyses of the deepest XMM-Newton observations of ULXs that address their
underlying nature. We examine both empirical and physical modelling of the
X-ray spectra of a sample of thirteen of the highest quality ULX datasets, and
find that there are anomalies in modelling ULXs as accreting IMBHs with
properties simply scaled-up from Galactic black holes. Most notably, spectral
curvature above 2 keV in several sources implies the presence of an
optically-thick, cool corona. We also present a new analysis of a 100 ks
observation of Holmberg II X-1, in which a rigorous analysis of the temporal
data limits the mass of its black hole to no more than 100 solar masses. We
argue that a combination of these results points towards many (though not
necessarily all) ULXs containing black holes that are at most a few 10s of
solar mass in size.Comment: 5 pages, 2 figures, to appear in the proceedings of "The X-ray
Universe 2005", San Lorenzo de El Escorial (Spain), 26-30 September 200
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