22,923 research outputs found
Therapists' characteristics associated with the (non-)use of exposure in the treatment of anxiety disorders in youth:A survey among Dutch-speaking mental health practitioners
INTRODUCTION: Although there is consensus that exposure is the key ingredient in treating childhood anxiety disorders, several studies in the USA suggest exposure to be underused in clinical practice. Previous research pointed to therapists' beliefs about exposure, their age, experience, caseload, training and theoretical orientation, as well as the level of the therapists' own anxiety as important factors in the underusage of exposure in the treatment of adult anxiety disorders. This study examined what therapist characteristics may be involved in the (non-)use of exposure in treating childhood anxiety disorders. METHODS: An internet-based survey among 207 youth mental health care professionals in the Netherlands and Belgium was conducted to assess therapists' beliefs about exposure, their age, experience, caseload, training and theoretical orientation, as well as the level of the therapists' own anxiety, depression and stress. RESULTS: The current survey showed that therapists used exposure in about half of their cases of childhood anxiety and that the non-use was independently associated with the relatively strong negative beliefs about exposure, therapists' age, and non-CBT orientation. DISCUSSION: Findings point to the importance of addressing negative beliefs about exposure in therapists' training and supervision to resolve therapy drift away from exposure, and consequently improve utilization and delivery of exposure-based therapy for childhood anxiety disorders
Split-gate quantum point contacts with tunable channel length
We report on developing split-gate quantum point contacts (QPCs) that have a
tunable length for the transport channel. The QPCs were realized in a
GaAs/AlGaAs heterostructure with a two- dimensional electron gas (2DEG) below
its surface. The conventional design uses 2 gate fingers on the wafer surface
which deplete the 2DEG underneath when a negative gate voltage is applied, and
this allows for tuning the width of the QPC channel. Our design has 6 gate
fingers and this provides additional control over the form of the electrostatic
potential that defines the channel. Our study is based on electrostatic
simulations and experiments and the results show that we developed QPCs where
the effective channel length can be tuned from about 200 nm to 600 nm.
Length-tunable QPCs are important for studies of electron many-body effects
because these phenomena show a nanoscale dependence on the dimensions of the
QPC channel
Evolution in the Dust Lane Fraction of Edge-on L* Spiral Galaxies since z=0.8
The presence of a well-defined and narrow dust lane in an edge-on spiral
galaxy is the observational signature of a thin and dense molecular disk, in
which gravitational collapse has overcome turbulence. Using a sample of
galaxies out to z~1 extracted from the COSMOS survey, we identify the fraction
of massive disks that display a dust lane. Our goal is to explore the evolution
in the stability of the molecular ISM disks in spiral galaxies over a cosmic
timescale. We check the reliability of our morphological classifications
against changes in restframe wavelength, resolution, and cosmic dimming with
(artificially redshifted) images of local galaxies from SDSS. We find that the
fraction of L* disks with dust lanes in COSMOS is consistent with the local
fraction (~80%) out to z~0.7. At z=0.8, the dust lane fraction is only slightly
lower. A somewhat lower dust lane fraction in starbursting galaxies tentatively
supports the notion that a high specific star formation rate can efficiently
destroy or inhibit a dense molecular disk. A small subsample of higher redshift
COSMOS galaxies display low internal reddening (E[B-V]), as well as a low
incidence of dust lanes. These may be disks in which the growth of the dusty
ISM disk lags behind that of the stellar disk. We note that at z=0.8, the most
massive galaxies display a lower dust lane fraction than lower mass galaxies. A
small contribution of recent mergers or starbursts to this most massive
population may be responsible. The fact that the fraction of galaxies with dust
lanes in COSMOS is consistent with little or no evolution implies that models
to explain the Spectral Energy Distribution or the host galaxy dust extinction
of supernovae based on local galaxies are still applicable to higher redshift
spirals. It also suggests that dust lanes are long lived phenomena or can be
reformed over very short time-scales.Comment: 14 pages, 9 figures, 2 tables, accepted for publication by Ap
Big Cities, Big Problems? Reason for the Elderly to Move?
In many European countries, data on geographical patterns of internal elderly migration show that the elderly (55+) are more likely to leave than to move to the big cities. Besides emphasising the attractive features of the destination areas (pull factors), it is often assumed that this negative balance of migration of elderly people is caused by problems which mainly the big cities have to contend with and which would have a negative effect on living conditions, especially of the elderly (push factors). Although it is well-known that big cities in Europe are faced with several specific housing and neighbourhood problems, no detailed research has been carried out so far into whether these problems are indeed seen by the elderly themselves as very negative and, if so, whether these perceived problems result in an intention to move as a result of housing and neighbourhood dissatisfaction. The aim of this article is to shed empirical light on this matter for a case study in the Netherlands
Liver microwave ablation:a systematic review of various FDA-approved systems
ObjectivesThe aim of the present study is to analyze preclinical and clinical data on the performance of the currently US Food and Drug Administration (FDA)-approved microwave ablation (MWA) systems.MethodsA review of the literature, published between January 1, 2005, and December 31, 2016, on seven FDA-approved MWA systems, was conducted. Ratio of ablation zone volume to applied energy R(AZ:E) and sphericity indices were calculated for ex vivo and in vivo experiments.ResultsThirty-four studies with ex vivo, in vivo, and clinical data were summarized. In total, 14 studies reporting data on ablation zone volume and applied energy were included for comparison R(AZ:E). A significant correlation between volume and energy was found for the ex vivo experiments (r=0.85,
XTE J1550-564: INTEGRAL Observations of a Failed Outburst
The well known black-hole X-ray binary transient XTE J1550-564 underwent an
outburst during the spring of 2003 which was substantially underluminous in
comparison to previous periods of peak activity in that source. In addition,
our analysis shows that it apparently remained in the hard spectral state over
the duration of that outburst. This is again in sharp contrast to major
outbursts of that source in 1998/1999 during which it exhibited an irregular
light curve, multiple state changes and collimated outflows. This leads us to
classify it as a "failed outburst." We present the results of our study of the
spring 2003 event including light curves based on observations from both
INTEGRAL and RXTE. In addition, we studied the evolution of the high-energy
3-300 keV continuum spectrum using data obtained with three main instruments on
INTEGRAL. These spectra are consistent with typical low-hard-state thermal
Comptonization emission. We also consider the 2003 event in the context of a
multi-source, multi-event period-peak luminosity diagram in which it is a clear
outlyer. We then consider the possibility that the 2003 event was due to a
discrete accretion event rather than a limit-cycle instablility. In that
context, we apply model fitting to derive the timescale for viscous propagation
in the disk, and infer some physical characteristics.Comment: 22 pages, 8 figures, to be published in The Astrophysical Journa
Remote collaboration and innovative performance:the moderating role of R&D intensity
Collaboration with geographically distant partners may enhance a firm’s innovative performance. In practice, however, this may be complicated as personal contacts are more limited so that effective search and transfer of remote partners’ tacit knowledge is hampered. We tested the potential moderating role of R&D intensity which, by indicating technology-oriented absorptive capacity, may mitigate the problems associated with remote collaboration. Drawing on survey data of 248 high-tech small firms, we find that remote collaboration is positively related with innovation performance, but at low R&D intensity, the relationship vanishes
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