795 research outputs found
First-Year Movements by Juvenile Mexican Spotted Owls in the Canyonlands of Utah
We studied first-year movements of Mexican Spotted Owls (Strix occidentalis lucida) during natal dispersal in canyonlands of southern Utah. Thirty-one juvenile Mexican Spotted Owls were captured and radiotracked during 1992-95 to examine behavior and conduct experiments related to the onset of natal dispersal. Juvenile Spotted Owls dispersed from their nest areas during September to October each year, with 85% leaving in September. The onset of movements was sudden and juveniles dispersed in varied directions. The median distance from nest area to last observed location was 25.7 km (range = 1.7-92.3 km). Three of 26 juveniles tracked (11%) were alive after one year, although none were observed with mates. We conducted a feeding experiment, using Mongolian gerbils (Meriones unguicuculatus), to test the influence of increased food supply on dispersal onset. The mean dispersal date of five owls that received supplemental food Julian day no. 255 +/- 2.6 SD) was significantly different than a control group (day no. 273 +/- 12.3)
The effect of e-mental health interventions on academic performance in university and college students:A meta-analysis of randomized controlled trials
Background: Mental health symptoms are common among college and university students and these can affect their academic performance. E-mental health interventions have proven effective in addressing mental health complaints but their effect on academic performance has not been synthesized yet. Objectives: To synthesize the evidence from randomized controlled trials for the effectiveness of e-mental health interventions on academic performance in college and university students compared to inactive controls. Data sources and eligibility criteria: We searched six databases (PubMed, Cochrane library, CINAHL, ERIC, PsycINFO, Web of Science) during the period January 2000 until September 2019 for randomized controlled trials that reported on e-mental health interventions (guided or unguided) for college and university students and measured academic performance (e.g. grade point average). Study appraisal and synthesis methods: Study and participant characteristics and the academic performance measures at post-intervention were extracted. The latter were pooled and Hedges' g was calculated as the effect size. Heterogeneity and publication bias were investigated. Results: Six studies containing 2428 participants were included in the meta-analysis. These focussed on either mood and anxiety or alcohol and tobacco use. The pooling of data resulted in a small but non-significant effect of g = 0.26 (95% CI, −0.00, 0.52; p = .05) on academic performance, favouring e-mental health interventions over inactive controls. Interventions had positive effects on depression (g = −0.24) and anxiety (g = −0.2). Heterogeneity was high. Discussion: Despite the small and non-significant effect, our meta-analysis points to a promising direction for the effectiveness of e-mental health interventions on academic performance. Yet, these results must be interpreted with caution, as heterogeneity was high and few studies on the effectiveness of e-mental health interventions for students reported academic performance measures
Log in and breathe out: efficacy and cost-effectiveness of an online sleep training for teachers affected by work-related strain-study protocol for a randomized controlled trial
Background: Insomnia and work-related stress often co-occur. Both are associated with personal distress and diminished general functioning, as well as substantial socio-economic costs due to, for example, reduced productivity at the work place and absenteeism. Insomnia complaints by people experiencing work-related stress are correlated with a deficient cognitive detachment from work. Diffuse boundaries between work and private life can additionally complicate the use of recreational activities that facilitate cognitive detachment.Cognitive behavioral therapy for insomnia is effective but rarely implemented. Internet-based cognitive behavioral therapy for insomnia could potentially reduce this deficit given its demonstrated effectiveness. Less is known, however, about the efficacy of internet-based cognitive behavioral therapy for insomnia in populations affected by high work stress. Thus, the aim of the present study is to evaluate the efficacy and cost-effectiveness of a newly developed, guided online training which is based on Cognitive Behavioral Therapy for insomnia and tailored to teachers affected by occupational stress.Methods/Design: In a two-arm randomized controlled trial (N = 128), the effects of a guided online sleep training will be compared to a waitlist-control condition. German teachers with significant clinical insomnia complaints (Insomnia Severity Index ≥15) and work-related rumination (Irritation Scale, subscale Cognitive Irritation ≥15) will be included in the study. The primary outcome measure will be insomnia severity. Additionally, an economic evaluation from a societal perspective will be conducted. Data from the intention-to-treat sample will be analyzed two and six months after randomization.Discussion: To the best of our knowledge, this is the first study to evaluate an online sleep training tailored to a specific population with work stress, that is, teachers. If this type of intervention is effective, it could reduce the paucity of cognitive behavioral therapy for insomnia and augment the support for teachers in coping with their insomnia problems.Trial registration: German Clinical Trial Register (DRKS): DRKS00004700. © 2013 Thiart et al.; licensee BioMed Central Ltd
Cooling of Hybrid Neutron Stars and Hypothetical Self-bound Objects with Superconducting Quark Cores
We study the consequences of superconducting quark cores (with
color-flavor-locked phase as representative example) for evolution of
temperature profiles and the cooling curves in quark-hadron hybrid stars and in
hypothetical self-bounded objects having no a hadron shell (quark core neutron
stars). The quark gaps are varied from 0 to MeV. For hybrid
stars we find time scales of , and years for the
formation of a quasistationary temperature distribution in the cases , 0.1 MeV and \gsim 1 MeV, respectively. These time scales are governed by
the heat transport within quark cores for large diquark gaps (\Delta \gsim 1
MeV) and within the hadron shell for small diquark gaps (\Delta \lsim 0.1
MeV). For quark core neutron stars we find a time scale years for
the formation of a quasistationary temperature distribution in the case \Delta
\gsim 10 MeV and a very short one for \Delta \lsim 1 MeV. If hot young
compact objects will be observed they can be interpreted as manifestation of
large gap color superconductivity. Depending on the size of the pairing gaps,
the compact star takes different paths in the vs. diagram
where is the surface temperature. Compared to the corresponding hadronic
model which well fits existing data the model for the hybrid neutron star (with
a large diquark gap) shows too fast cooling. The same conclusion can be drawn
for the corresponding self-bound objects.Comment: 8 pages, 4 figures, uses aa-package (included), accepted for A&
Evaluating the efficacy and cost-effectiveness of web-based indicated prevention of major depression: design of a randomised controlled trial
BACKGROUND: Major depressive disorder (MDD) imposes a considerable disease burden on individuals and societies. Web-based interventions have shown to be effective in reducing depressive symptom severity. However, it is not known whether web-based interventions may also be effective in preventing the onset of MDD. The aim of this study is to evaluate the (cost-) effectiveness of an indicated web-based guided self-help intervention (GET.ON Mood Enhancer Prevention) on the onset of MDD. METHODS/DESIGN: A randomised controlled trial (RCT) will be conducted to compare the (cost-) effectiveness of the GET.ON Mood Enhancer Prevention training with a control condition exclusively receiving online-based psychoeducation on depression. Adults with subthreshold depression (N = 406) will be recruited from the general population and randomised to one of the two conditions. The primary outcome is time to onset of MDD within a 12-months follow-up period. MDD will be assessed according to DSM-IV criteria as assessed by the telephone-administered Structured Clinical Interview for DSM-IV (SCID). Time to onset of MDD will be assessed using life charts. Secondary outcomes include changes on various indicators of depressive symptom severity, anxiety and quality of life from baseline to post-treatment, to a 6-month and a 12-month follow up. Additionally, an economic evaluation using a societal perspective will be conducted to examine the intervention’s cost-effectiveness. DISCUSSION: This is one of the first randomised controlled trials that examines the effect of an indicated guided self-help web-based intervention on the incidence of major depression. If shown to be effective, the intervention will contribute to reducing the disease burden due to MDD in the general population. TRIAL REGISTRATION: German Clinical Trial Registration DRKS00004709
The effect of the neutron star crust on the evolution of a core magnetic field
We consider the expulsion of the magnetic field from the super-conducting
core of a neutron star and its subsequent decay in the crust. Particular
attention is paid to a strong feedback of the distortion of magnetic field
lines in the crust on the expulsion of the flux from the core. This causes a
considerable delay of the core flux expulsion if the initial field strength is
larger than 10^{11} G. It is shown that the hypothesis on the magnetic field
expulsion induced by the neutron star spin-down is adequate only for a
relatively weak initial magnetic field G. The expulsion
time-scale depends not only on the conductivity of the crust, but also on the
initial magnetic field strength itself. Our model of the field evolution
naturally explains the existence of the residual magnetic field of neutron
stars. Its strength is correlated with the impurity concentration in neutron
star crusts and anti-correlated with the initial field strengths.Comment: 15 pages, 6 figures, accepted to MNRA
The Occurrence of the Hall--Instability in Crusts of Isolated Neutron Stars
In former papers we showed that during the decay of a neutron star's magnetic
field under the influence of the Hall--drift, an unstable rise of small--scale
field structures at the expense of the large--scale background field may
happen. This linear stability analysis was based on the assumption of a uniform
density throughout the neutron star crust, whereas in reality the density and
all transport coefficients vary by many orders of magnitude. Here, we extend
the investigation of the Hall--drift induced instability by considering
realistic profiles of density and chemical composition, as well as background
fields with more justified radial profiles. Two neutron star models are
considered differing primarily in the assumption on the core matter equation of
state. For their cooling history and radial profiles of density and composition
we use known results to infer the conductivity profiles. These were fed into
linear calculations of a dipolar field decay starting from various initial
configurations. At different stages of the decay, snapshots of the magnetic
fields at the equator were taken to yield background field profiles for the
stability analysis. The main result is that the Hall instability may really
occur in neutron star crusts. Characteristic growth times are in the order of
\lesssim 10^4 ... 10^6 yrs depending on cooling age and background field
strength. The influence of the equation of state and of the initial field
configuration is discussed.Comment: 16 pages, 16 figures, PS, submitted to A&A. Justification/discussion
slightly changed/extended in replying to the referee. Changes on p. 3, 11,
13, framed by XXX mark
Efficacy of an internet-based problem-solving training for teachers: results of a randomized controlled trial
Objective The primary purpose of this randomized controlled trial (RCT) was to evaluate the efficacy of internet-based problem-solving training (iPST) for employees in the educational sector (teachers) with depressive symptoms. The results of training were compared to those of a waitlist control group (WLC). Methods One-hundred and fifty teachers with elevated depressive symptoms (Center for Epidemiologic Studies Depression Scale, CES-D ≥16) were assigned to either the iPST or WLC group. The iPST consisted of five lessons, including problem-solving and rumination techniques. Symptoms were assessed before the intervention began and in follow-up assessments after seven weeks, three months, and six months. The primary outcome was depressive symptom severity (CES-D). Secondary outcomes included general and work-specific self-efficacy, perceived stress, pathological worries, burnout symptoms, general physical and mental health, and absenteeism. Results iPST participants displayed a significantly greater reduction in depressive symptoms after the intervention (d=0.59, 95% CI 0.26-0.92), after three months (d=0.37, 95% CI 0.05-0.70) and after six months (d=0.38, 95% CI 0.05-0.70) compared to the control group. The iPST participants also displayed significantly higher improvements in secondary outcomes. However, workplace absenteeism was not significantly affected. Conclusion iPST is effective in reducing symptoms of depression among teachers. Disseminated on a large scale, iPST could contribute to reducing the burden of stress-related mental health problems among teachers. Future studies should evaluate iPST approaches for use in other working populations
Landbird Migration in the American West: Recent Progress and Future Research Directions
Our knowledge of avian behaviors during the non-breeding period still lags behind that of the breeding season, but the last decade has witnessed a proliferation in research that has yielded significant progress in understanding migration patterns of North American birds. And, although the great majority of migration research has historically been conducted in the eastern half of the continent, there has been much recent progress on aspects of avian migration in the West. In particular, expanded use of techniques such as radar, plasma metabolites, mist-netting, count surveys, stable isotopes, genetic data, and animal tracking, coupled with an increase in multi-investigator collaborations, have all contributed to this growth of knowledge. There is increasing recognition that migration is likely the most limiting time of year for migratory birds, and this places increasing importance on continuing to decipher patterns of stopover ecology, identifying critical stopover habitats, and documenting migration routes in the diverse and changing landscapes of the American West. Here, we review and briefly synthesize the latest avian migration findings and advances and consider research needs to guide future research on migration in the West
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