121 research outputs found
Coping measurement and the state effect of depression and anxiety in psychiatric outpatients
The relationship between coping styles and mental health has received considerable attention, but the state effects on coping measures in a clinical sample are not well known. This study investigated changes in scores on the Coping Inventory for Stressful Situations between two treatment phases (acute and remitted phase) in 49 outpatients with major depression or anxiety disorders. Task-oriented coping changed significantly between the treatment phases in both depressive and anxious patients, as analyzed by two-way multivariate analysis of variance. Results from repeated measures of multivariate analysis of covariance indicated that task-oriented coping was influenced by depression and emotion-oriented coping was influenced by anxiety. Avoidance-oriented coping did not change significantly over time in either depressive or anxiety disorders controlled for depressive and anxiety symptoms. The results of this study suggest that depressive or anxiety symptoms and treatment phase affect coping measurement. Copyright (C) 2002 S. Karger AG, Basel
Turbulence Generation by Substructure Motion in Clusters of Galaxies
Clusters of galaxies form through major merger and/or absorption of smaller
groups. In fact, some characteristic structures such as cold fronts, which are
likely relevant to moving substructures, are found by {\it Chandra}. It is
expected that moving substructures generate turbulence in the intracluster
medium (ICM). Such turbulence probably plays a crucial role in mixture and
transport of gas energy and heavy elements, and particle acceleration. The {\it
Astro-E2} satellite, which is planned to be launched in 2005, will detect
broadened lines due to turbulent motion. In order to explore the
above-mentioned issues, it is important to investigate the generation processes
and structure of ICM turbulence. We investigate the ICM dynamical evolution in
and around a moving substructure with three-dimensional hydrodynamical
simulations. Eddy-like structures develop near the boundary between the
substructure and the ambient ICM through Kelvin-Helmholtz instabilities.
Because of these structures, characteristic patterns appear in the
line-of-sight velocity distribution of the ICM.Comment: 6 pages, 3 figures, Accepted for publication in Advances in Space
Research (Proceedings of COSPAR-2004
Childhood bullying victimisation is associated with use of mental health services over five decades: a longitudinal nationally-representative cohort study
Background: Research supports robust associations between childhood bullying victimisation and mental health problems in childhood/adolescence and emerging evidence shows the impact can persist into adulthood. We examined the impact of bullying victimisation on mental health service use from childhood to midlife. Methods: We performed secondary analysis using the National Child Development Study, the 1958 British Birth Cohort study. We conducted analyses on 9,242 participants with complete data on childhood bullying victimisation and service use at midlife. We used multivariable logistic regression models to examine associations between childhood bullying victimisation and mental health service use ages 16, 23, 33, 42 and 50. We estimated incidence and persistence of mental health service use over time to age 50. Results: Compared to participants who were not bullied in childhood, those who were frequently bullied were more likely to use mental health services in childhood and adolescence (OR: 2.53, 95% CI: 1.88, 3.40), and also in midlife (OR: 1.30, 95% CI: 1.10, 1.55). Disparity in service use associated with childhood bullying victimisation was accounted for by both incident service use through to age 33 by a sub-group of participants, and by persistent use up to midlife. Conclusions: Childhood bullying victimisation adds to the pressure on an already stretched health care system. Policy and practice efforts providing support for victims of bullying could help contain public sector costs. Given constrained budgets and the long-term mental health impact on victims of bullying, early prevention strategies could be effective at limiting both individual distress and later costs
Developmental Changes of Prefrontal Activation in Humans: A Near-Infrared Spectroscopy Study of Preschool Children and Adults
Previous morphological studies indicated that development of the human prefrontal cortex (PFC) appears to continue into late adolescence. Although functional brain imaging studies have sought to determine the time course of functional development of the PFC, it is unclear whether the developmental change occurs after adolescence to adulthood and when it achieves a peak because of the narrow or discontinuous range in the participant's age. Moreover, previous functional studies have not focused on the anterior frontal region, that is, the frontopolar regions (BA9/10). Thus, the present study investigated the developmental change in frontopolar PFC activation associated with letter fluency task by using near-infrared spectroscopy (NIRS), in subjects from preschool children to adults. We analyzed the relative concentration of hemoglobin (ΔHb) in the prefrontal cortex measured during the activation task in 48 typically-developing children and adolescents and 22 healthy adults. Consistent with prior morphological studies, we found developmental change with age in the children/adolescents. Moreover, the average Δoxy-Hb in adult males was significantly larger than that in child/adolescent males, but was not true for females. These data suggested that functional development of the PFC continues into late adolescence. Although the developmental change of the frontopolar PFC was independent of gender from childhood to adolescence, in adulthood a gender difference was shown
The Properties of X-ray Cold Fronts in a Statistical Sample of Simulated Galaxy Clusters
We examine the incidence of cold fronts in a large sample of galaxy clusters
extracted from a (512h^-1 Mpc) hydrodynamic/N-body cosmological simulation with
adiabatic gas physics computed with the Enzo adaptive mesh refinement code.
This simulation contains a sample of roughly 4000 galaxy clusters with M >
10^14 M_sun at z=0. For each simulated galaxy cluster, we have created mock
0.3-8.0 keV X-ray observations and spectroscopic-like temperature maps. We have
searched these maps with a new automated algorithm to identify the presence of
cold fronts in projection. Using a threshold of a minimum of 10 cold front
pixels in our images, corresponding to a total comoving length L_cf > 156h^-1
kpc, we find that roughly 10-12% of all projections in a mass-limited sample
would be classified as cold front clusters. Interestingly, the fraction of
clusters with extended cold front features in our synthetic maps of a
mass-limited sample trends only weakly with redshift out to z=1.0. However,
when using different selection functions, including a simulated flux limit, the
trending with redshift changes significantly. The likelihood of finding cold
fronts in the simulated clusters in our sample is a strong function of cluster
mass. In clusters with M>7.5x10^14 M_sun the cold front fraction is 40-50%. We
also show that the presence of cold fronts is strongly correlated with
disturbed morphology as measured by quantitative structure measures. Finally,
we find that the incidence of cold fronts in the simulated cluster images is
strongly dependent on baryonic physics.Comment: 16 pages, 21 figures, Accepted to Ap
Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure
(Abridged) We present results of Suzaku observations of the intracluster
medium (ICM) in Abell 1689, combined with complementary analysis of the SDSS
data and weak and strong lensing analysis of Subaru/Suprime-Cam and HST/ACS
observations. Faint X-ray emission from the ICM around the virial radius is
detected at 4.0 sigma significance. We find anisotropic gas temperature and
entropy distributions in cluster outskirts correlated with large-scale
structure of galaxies. The high temperature and entropy region in the
northeastern (NE) outskirts is connected to an overdense filamentary structure.
The outskirt regions in contact with low density void environments have low gas
temperatures and entropies, deviating from hydrostatic equilibrium. These
results suggest that thermalization of the ICM occurs faster along the
filamentary structures than the void regions. A joint X-ray and lensing
analysis shows that the hydrostatic mass is of spherical lensing
one but comparable to a triaxial halo mass within errors in 0.6r_{2500} \simlt
r \simlt 0.8r_{500}, and that it is significantly biased as low as \simlt60%
within , irrespective of mass models. The thermal gas pressure
within is, at most, --60% of the total pressure to balance
fully the gravity of the spherical lensing mass, and --40% around the
virial radius. Although these constitute lower limits when one considers the
possible halo triaxiality, these small relative contributions of thermal
pressure would require additional sources of pressure, such as bulk and/or
turbulent motions.Comment: 24 pages, 15 figures, 9 tables. Accepted for publication in Ap
Recommended from our members
Psychosocial twin cohort studies in Japan: the Keio Twin Research Center (KoTReC)
The Keio Twin Research Center (KoTReC) was established in 2009 at Keio University to combine two longitudinal cohort projects — the Keio Twin Study (KTS) for adolescence and adulthood and the Tokyo Twin Cohort Project (ToTCoP) for infancy and childhood. KoTReC also conducted a two-time panel study of self-control and psychopathology in twin adolescence in 2012 and 2013 and three independent anonymous cross-sectional twin surveys (ToTcross) before 2012 — the ToTCross, the Junior and Senior High School Survey and the High School Survey. This article introduces the recent research designs of KoTReC and its publications
Evolution of shocks and turbulence in major cluster mergers
We performed a set of cosmological simulations of major mergers in galaxy
clusters to study the evolution of merger shocks and the subsequent injection
of turbulence in the post-shock region and in the intra-cluster medium (ICM).
The computations were done with the grid-based, adaptive mesh refinement hydro
code Enzo, using an especially designed refinement criteria for refining
turbulent flows in the vicinity of shocks. A substantial amount of turbulence
energy is injected in the ICM due to major merger. Our simulations show that
the shock launched after a major merger develops an ellipsoidal shape and gets
broken by the interaction with the filamentary cosmic web around the merging
cluster. The size of the post-shock region along the direction of shock
propagation is about 300 kpc h^-1, and the turbulent velocity dispersion in
this region is larger than 100 km s^-1. Scaling analysis of the turbulence
energy with the cluster mass within our cluster sample is consistent with
M^(5/3), i.e. the scaling law for the thermal energy in the self-similar
cluster model. This clearly indicates the close relation between virialization
and injection of turbulence in the cluster evolution. We found that the ratio
of the turbulent to total pressure in the cluster core within 2 Gyr after the
major merger is larger than 10%, and it takes about 4 Gyr to get relaxed, which
is substantially longer than typically assumed in the turbulent re-acceleration
models, invoked to explain the statistics of observed radio halos. Striking
similarities in the morphology and other physical parameters between our
simulations and the "symmetrical radio relics" found at the periphery of the
merging cluster A3376 are finally discussed. In particular, the interaction
between the merger shock and the filaments surrounding the cluster could
explain the presence of "notch-like" features at the edges of the double
relics.Comment: 16 pages, 19 figures, Published in Astrophysical Journal (online) and
printed version will be published on 1st January, 201
Effects of the Non-Equipartition of Electrons and Ions in the Outskirts of Relaxed Galaxy Clusters
(abridged) We have studied the effects of electron-ion non-equipartition in
the outer regions of relaxed clusters for a wide range of masses in the
\LambdaCDM cosmology using one-dimensional hydrodynamic simulations. The
effects of the non-adiabatic electron heating efficiency, \beta, on the degree
of non-equipartition are also studied. Using the gas fraction f_gas = 0.17
(which is the upper limit for a cluster), we give a conservative lower limit of
the non-equipartition effect on clusters. Beyond the virial radius, the
non-equipartition effect depends rather strongly on \beta, and such a strong
dependence at the shock radius can be used to distinguish shock heating models
or constrain the shock heating efficiency of electrons. We have also studied
systematically the signatures of non-equipartition on X-ray and SZ observables.
We have calculated the effect of non-equipartition on the projected temperature
and X-ray surface brightness profiles using the MEKAL emission model. The
non-equipartition effect can introduce a ~10% bias in the projected temperature
at R_vir for a wide range of \beta. We also found that the effect of
non-equipartition on the projected temperature profiles can be enhanced by
increasing metallicity. We found that for our model in the \LambdaCDM Universe,
the integrated SZ bias, Y_{non-eq}/Y_{eq}, evolves slightly (at a percentage
level) with redshift, which is in contrast to the self-similar model in the
Einstein-de Sitter Universe. This may introduce biases in cosmological studies
using the f_gas technique. We discussed briefly whether the equipartition and
non-equipartition models near the shock region can be distinguished by future
radio observations with, for example, ALMA.Comment: 28 pages, 19 figures, accepted for publication in the Astrophysical
Journal. Typos corrected in version
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