1,051 research outputs found
Relationships Among Depression, Anxiety, and Insomnia Symptoms in Perinatal Women Seeking Mental Health Treatment
Background: Depression and anxiety symptoms are commonly experienced by women during the perinatal period. Changes in sleep and sleep quality are typical throughout pregnancy and early postpartum. However, little is known about relationships between insomnia symptoms and psychiatric symptoms in perinatal women. The objective of the present study is to characterize the burden of insomnia symptoms in perinatal women seeking outpatient psychiatric treatment and to examine relationships between insomnia and symptoms of depression and anxiety. Methods: Data from 257 pregnant or postpartum women who sought outpatient psychiatric treatment at a university hospital-affiliated clinic were extracted from an existing clinical management database. Data included validated self-report measures assessing insomnia (Insomnia Severity Index [ISI]), mood (Edinburgh Postnatal Depression Scale [EPDS]), and generalized anxiety (Penn State Worry Questionnaire [PSWQ]). Results: Fifty-two percent of women reported symptoms of insomnia, 75% reported symptoms of depression, and 61% reported symptoms of generalized anxiety. After controlling for PSWQ, the partial correlation between EPDS and ISI was 0.15 and 0.37 for pregnant and postpartum women, respectively. After controlling for EPDS, the partial correlation between PSWQ and ISI was 0.20 and 0.12 for pregnant and postpartum women, respectively. Women with clinically significant ISI scores had significantly higher odds for reporting symptoms consistent with depression (odds ratio [OR] 7.7) and generalized anxiety (OR 2.55) compared to women with lower ISI scores. Conclusions: Insomnia symptoms affected a significant proportion of the perinatal women in this sample. These symptoms are linked to symptoms of depression and anxiety in treatment-seeking pregnant and postpartum women. Perinatal women seen in psychiatric treatment settings should be routinely screened for sleep problems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90453/1/jwh-2E2010-2E2371.pd
Particle transport in evolving protoplanetary disks: Implications for results from Stardust
Samples returned from comet 81P/Wild 2 by Stardust confirm that substantial
quantities of crystalline silicates were incorporated into the comet at
formation. We investigate the constraints that this observation places upon
protoplanetary disk physics, assuming that outward transport of particles
processed at high temperatures occurs via advection and turbulent diffusion in
an evolving disk. We also look for constraints on particle formation locations.
Our results are based upon 1D disk models that evolve with time under the
action of viscosity and photoevaporation, and track solid transport using an
ensemble of individual particle trajectories. We find that two classes of disk
model are consistent with the Stardust findings. One class features a high
particle diffusivity (a Schmidt number Sc < 1), which suffices to diffuse
particles up to 20 microns in size outward against the mean gas flow. For Sc >
1, such models are unlikely to be viable, and significant outward transport
requires that the particles of interest settle into a midplane layer that
experiences an outward gas flow. In either class of models, the mass of inner
disk material that reaches the outer disk is a strong function of the disk's
initial compactness. Hence, models of grain transport within steady-state disks
underestimate the efficiency of outward transport. Neither model results in
sustained outward transport of very large particles exceeding a mm in size. We
show that the transport efficiency generally falls off rapidly with time.
Hence, high-temperature material must be rapidly incorporated into icy bodies
to avoid fallback, and significant radial transport may only occur during the
initial phase of rapid disk evolution. It may also vary substantially between
disks depending upon their initial mass distributions. We discuss implications
for Spitzer observations of crystalline silicates in T Tauri disks.Comment: ApJ, in pres
PilZ Domain Protein FlgZ Mediates Cyclic Di-GMP-Dependent Swarming Motility Control in Pseudomonas aeruginosa
The second messenger cyclic diguanylate (c-di-GMP) is an important regulator of motility in many bacterial species. In Pseudomonas aeruginosa, elevated levels of c-di-GMP promote biofilm formation and repress flagellum-driven swarming motility. The rotation of P. aeruginosa\u27s polar flagellum is controlled by two distinct stator complexes, MotAB, which cannot support swarming motility, and MotCD, which promotes swarming motility. Here we show that when c-di-GMP levels are elevated, swarming motility is repressed by the PilZ domain-containing protein FlgZ and by Pel polysaccharide production. We demonstrate that FlgZ interacts specifically with the motility-promoting stator protein MotC in a c-di-GMP-dependent manner and that a functional green fluorescent protein (GFP)-FlgZ fusion protein shows significantly reduced polar localization in a strain lacking the MotCD stator. Our results establish FlgZ as a c-di-GMP receptor affecting swarming motility by P. aeruginosa and support a model wherein c-di-GMP-bound FlgZ impedes motility via its interaction with the MotCD stator
Collapse of a molecular cloud core to stellar densities: the radiative impact of stellar core formation on the circumstellar disc
We present results from the first three-dimensional radiation hydrodynamical
calculations to follow the collapse of a molecular cloud core beyond the
formation of the stellar core. We find the energy released by the formation of
the stellar core, within the optically-thick first hydrostatic core, is
comparable to the binding energy of the disc-like first core. This heats the
inner regions of the disc, drives a shock wave through the disc, dramatically
decreases the accretion rate on to the stellar core, and launches a temporary
bipolar outflow perpendicular to the rotation axis that travels in excess of 50
AU into the infalling envelope. This outburst may assist the young protostar in
launching a conventional magnetic jet. Furthermore, if these events are cyclic,
they may provide a mechanism for intense bursts of accretion separated by long
periods of relatively quiescent accretion which can potentially solve both the
protostellar luminosity problem and the apparent age spread of stars in young
clusters. Such outbursts may also provide a formation mechanism for the
chondrules found in meteorites, with the outflow transporting them to large
distances in the circumstellar disc.Comment: Accepted by MNRAS Letters. 6 pages, 4 figures. Animations can be
found at http://www.astro.ex.ac.uk/people/mbate/Animations/Stellar
Impact of brief self-affirmation manipulations on university students' reactions to risk information about binge drinking
Objectives
Binge drinking is associated with an array of negative health consequences and is particularly prevalent in university students. Health-risk messages about alcohol may fail to change such behaviour because they are dismissed or derogated. The present study sought to compare the effect of three brief self-affirmation manipulations on message processing, message acceptance, and subsequent alcohol-related behaviour in university students.
Design
Participants (N = 307) were randomly allocated to condition (kindness questionnaire, values essay, attributes questionnaire, control questionnaire) before reading a health-risk message about binge drinking.
Methods
After reading the message, participants completed measures of message processing (message reactance, message evaluation, counter-arguing) and message acceptance (perceived risk, intention, plans) as well as a manipulation check. Alcohol consumption was assessed 1 week later.
Results
Participants in all three self-affirmation conditions scored significantly higher than participants in the control condition on the manipulation check measure. All other self-affirmation effects were non-significant.
Conclusions
While the three self-affirmation manipulations were found to be self-affirming, they failed to impact on measures of message processing, message acceptance, or subsequent behaviour. The findings concur with previous research that questions the use of self-affirmation to reduce alcohol consumption in university students. Current self-affirmation manipulations may not be strong enough to overcome defensive processing of health-risk messages about alcohol in students and/or prime social goals that are related to the domain under threat (i.e., alcohol consumption), thereby nullifying any positive self-affirmation effects
The Cluster-EAGLE project: Velocity bias and the velocity dispersion-mass relation of cluster galaxies
We use the Cluster-EAGLE simulations to explore the velocity bias introduced when using galaxies, rather than dark matter particles, to estimate the velocity dispersion of a galaxy cluster, a property known to be tightly correlated with cluster mass. The simulations consist of 30 clusters spanning a mass range 14.0 ≤ log 10 (M 200 c /M ⊙ ) ≤ 15.4, with their sophisticated subgrid physics modelling and high numerical resolution (subkpc gravitational softening), making them ideal for this purpose. We find that selecting galaxies by their total mass results in a velocity dispersion that is 5-10 per cent higher than the dark matter particles. However, selecting galaxies by their stellar mass results in an almost unbiased ( < 5 per cent) estimator of the velocity dispersion. This result holds out to z = 1.5 and is relatively insensitive to the choice of cluster aperture, varying by less than 5 per cent between r 500 c and r 200m . We show that the velocity bias is a function of the time spent by a galaxy inside the cluster environment. Selecting galaxies by their total mass results in a larger bias because a larger fraction of objects have only recently entered the cluster and these have a velocity bias above unity. Galaxies that entered more than 4 Gyr ago become progressively colder with time, as expected from dynamical friction. We conclude that velocity bias should not be a major issue when estimating cluster masses from kinematic methods
Extended Near-Infrared Emission from Candidate Protostars in the Taurus-Auriga Molecular Cloud
We describe near-IR imaging data for a sample of 23 class I sources in the
Taurus-Auriga dark clouds. Combining our data with previous photometry, we
detect brightness variations of 0.1-0.5 mag in many sources. The near-IR
morphologies are consistent with mm continuum measurements. Most (60%) of the
sample are true protostars; the rest may be objects in transition between class
I and class II, T Tauri stars with edge-on disks, or heavily reddened T Tauri
stars.Comment: 15 pages, 3 tables, 4 figures; to appear in the June 2002
Astronomical Journa
- …