2,654 research outputs found
Auditory frequency threshold comparisons of humans and pre-adolescent chimpanzees
Auditory frequency threshold comparisons of humans and pre-adolescent chimpanzee
Internet-based CBT for depression with and without telephone tracking in a national helpline: randomised controlled trial
BACKGROUND Telephone helplines are frequently and repeatedly used by individuals with chronic mental health problems and web interventions may be an effective tool for reducing depression in this population. AIM To evaluate the effectiveness of a 6 week, web-based cognitive behaviour therapy (CBT) intervention with and without proactive weekly telephone tracking in the reduction of depression in callers to a helpline service. METHOD 155 callers to a national helpline service with moderate to high psychological distress were recruited and randomised to receive either Internet CBT plus weekly telephone follow-up; Internet CBT only; weekly telephone follow-up only; or treatment as usual. RESULTS Depression was lower in participants in the web intervention conditions both with and without telephone tracking compared to the treatment as usual condition both at post intervention and at 6 month follow-up. Telephone tracking provided by a lay telephone counsellor did not confer any additional advantage in terms of symptom reduction or adherence. CONCLUSIONS A web-based CBT program is effective both with and without telephone tracking for reducing depression in callers to a national helpline. TRIAL REGISTRATION Controlled-Trials.comISRCTN93903959.Funding for the trial was provided by an Australian Research Council Linkage Project Grant (LP0667970) (http://www.arc.gov.au/). LF is supported by an
Australian Postgraduate Award Industry scholarship. KG is supported by a National Health and Medical Research Council Fellowship (No. 525413) and HC is
supported by a National Health and Medical Research Council Fellowship (No. 525411)
Coulomb-Blockade directional coupler
A tunable directional coupler based on Coulomb Blockade effect is presented.
Two electron waveguides are coupled by a quantum dot to an injector waveguide.
Electron confinement is obtained by surface Schottky gates on single
GaAs/AlGaAs heterojunction. Magneto-electrical measurements down to 350 mK are
presented and large transconductance oscillations are reported on both outputs
up to 4.2 K. Experimental results are interpreted in terms of Coulomb Blockade
effect and the relevance of the present design strategy for the implementation
of an electronic multiplexer is underlined.Comment: 4 pages, 4 figures, to be published in Applied Physics Letter
Age differences in mental health literacy
BACKGROUND: The community's knowledge and beliefs about mental health problems, their risk
factors, treatments and sources of help may vary as a function of age.
METHODS: Data were taken from an epidemiological survey conducted during 2003–2004 with a
national clustered sample of Australian adults aged 18 years and over. Following the presentation
of a vignette describing depression (n = 1001) or schizophrenia (n = 997), respondents were asked
a series of questions relating to their knowledge and recognition of the disorder, beliefs about the
helpfulness of treating professionals and medical, psychological and lifestyle treatments, and likely
causes.
RESULTS: Participant age was coded into five categories and cross-tabulated with mental health
literacy variables. Comparisons between age groups revealed that although older adults (70+ years)
were poorer than younger age groups at correctly recognising depression and schizophrenia, young
adults (18–24 years) were more likely to misidentify schizophrenia as depression. Differences were
also observed between younger and older age groups in terms of beliefs about the helpfulness of
certain treating professionals and medical and lifestyle treatments for depression and
schizophrenia, and older respondents were more likely to believe that schizophrenia could be
caused by character weakness.
CONCLUSION: Differences in mental health literacy across the adult lifespan suggest that more
specific, age appropriate messages about mental health are required for younger and older age
groups. The tendency for young adults to 'over-identify' depression signals the need for awareness
campaigns to focus on differentiation between mental disorders
Free induction decay of a superposition stored in a quantum dot
We study the free evolution of a superposition initialized with high fidelity
in the neutral-exciton state of a quantum dot. Readout of the state at later
times is achieved by polarized photon detection, averaged over a large number
of cycles. By controlling the fine-structure splitting (FSS) of the dot with a
dc electric field, we show a reduction in the degree of polarization of the
signal when the splitting is minimized. In analogy with the "free induction
decay" observed in nuclear magnetic resonance, we attribute this to hyperfine
interactions with nuclei in the semiconductor. We numerically model this effect
and find good agreement with experimental studies. Our findings have
implications for storage of superpositions in solid-state systems and for
entangled photon pair emission protocols that require a small value of the FSS
Effect of continuous gamma-ray exposure on performance of learned tasks and effect of subsequent fractionated exposures on blood-forming tissue
Sixteen monkeys trained to perform continuous and discrete-avoidance and fixed-ratio tasks with visual and auditory cues were performance-tested before, during, and after 10-day gamma-ray exposures totaling 0, 500, 750, and 1000 rads. Approximately 14 months after the performance-test exposures, surviving animals were exposed to 100-rad gamma-ray fractions at 56-day intervals to observe injury and recovery patterns of blood-forming tissues. The fixed-ratio, food-reward task performance showed a transient decline in all dose groups within 24 hours of the start of gamma-ray exposure, followed by recovery to normal food-consumption levels within 48 to 72 hours. Avoidance tasks were performed successfully by all groups during the 10-day exposure, but reaction times of the two higher dose-rate groups in which animals received 3 and 4 rads per hour or total doses of 750 and 1000 rads, respectively, were somewhat slower
Magnetic Field Induced Instabilities in Localised Two-Dimensional Electron Systems
We report density dependent instabilities in the localised regime of
mesoscopic two-dimensional electron systems (2DES) with intermediate strength
of background disorder. They are manifested by strong resistance oscillations
induced by high perpendicular magnetic fields B_{\perp}. While the amplitude of
the oscillations is strongly enhanced with increasing B_{\perp}, their position
in density remains unaffected. The observation is accompanied by an unusual
behaviour of the temperature dependence of resistance and activation energies.
We suggest the interplay between a strongly interacting electron phase and the
background disorder as a possible explanation.Comment: 5 pages, 4 figure
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