236 research outputs found

    Does a short-term intervention promote mental and general health among young adults? – An evaluation of counselling

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    <p>Abstract</p> <p>Background</p> <p>Since 1988, self-reported mental health problems in Sweden have increased more among young people than in any other age group. Young adults aged 18 – 29 with minor mental health problems were welcomed to four (at most) counselling sessions led by psychotherapists. The present study aimed to evaluate the method's appropriateness and usefulness.</p> <p>Methods</p> <p>The study population was recruited consecutively during six months (N = 74) and consisted of 59 women and 15 men. Fifty-one, 46 women and five men, met the criterion for a <it>personal semi-structured interview </it>three months post intervention. Self-assessed health data were collected on three occasions using the General Health Questionnaire (GHQ-12), Pearlin's Personal Mastery Scale and two items from the Swedish Living Conditions Surveys. Thirteen women and six men were not statistically assessed due to incomplete data, but were <it>interviewed by telephone</it>. Four men refused to be interviewed and became <it>dropouts</it>.</p> <p>Results</p> <p>The largest group of the study population had long been troubled by their problem(s): 43 percent for over three years and 28 percent for over one year. Among those <it>personally interviewed</it>, 76 percent reported psychological distress (> 3 GHQ points) before the counselling. After the counselling, GHQ-12 distress decreased by 50 percent while mastery and perceived health status increased significantly. A majority experienced an improved life situation, found out something new about themselves and could make use of the sessions afterwards. Personal participant session contentment was about 70 percent and all counsellees would recommend the intervention to a friend. Those <it>interviewed by telephone </it>were not statistically assessed due to incomplete health data. Their personal contentment was just under 50 percent, though all except one would recommend the counselling to a friend. Their expectations of the intervention were more result-orientated compared to the more process-directed personally-interviewed group.</p> <p>Conclusion</p> <p>This evaluation shows a clear improvement in self-rated mental and general health, mastery and control in the group completing the study agreement. The intervention seems to be effective for young adults with minor mental health problems, but due to the skewed gender-distribution it is unclear if the method is appropriate for men. After the proposed internal quality improvements, this short-term counselling could enhance mental and general health among young people.</p

    Foundations of Black Hole Accretion Disk Theory

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    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).Comment: 91 pages, 23 figures, final published version available at http://www.livingreviews.org/lrr-2013-

    Identification of Methanoculleus spp. as active methanogens during anoxic incubations of swine manure storage tank samples

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    Methane emissions represent a major environmental concern associated with manure management in the livestock industry. A more thorough understanding of how microbial communities function in manure storage tanks is a prerequisite for mitigating methane emissions. Identifying the microorganisms that are metabolically active is an important first step. Methanogenic archaea are major contributors to methanogenesis in stored swine manure, and we investigated active methanogenic populations by DNA stable isotope probing (DNA-SIP). Following a preincubation of manure samples under anoxic conditions to induce substrate starvation, [U-ÂčÂłC] acetate was added as a labeled substrate. Fingerprint analysis of density-fractionated DNA, using length-heterogeneity analysis of PCR-amplified mcrA genes (encoding the alpha subunit of methyl coenzyme M reductase), showed that the incorporation of ÂčÂłC into DNA was detectable at in situ acetate concentrations (~7g/liter). Fingerprints of DNA retrieved from heavy fractions of the ÂčÂłC treatment were primarily enriched in a 483-bp amplicon and, to a lesser extent, in a 481-bp amplicon. Analyses based on clone libraries of the mcrA and 16S rRNA genes revealed that both of these heavy DNA amplicons corresponded to Methanoculleus spp. Our results demonstrate that uncultivated methanogenic archaea related to Methanoculleus spp. were major contributors to acetate-C assimilation during the anoxic incubation of swine manure storage tank samples. Carbon assimilation and dissimilation rate estimations suggested that Methanoculleus spp. were also major contributors to methane emissions and that the hydrogenotrophic pathway predominated during methanogenesis

    Association of narcolepsy-cataplexy with HLA-DRB1 and DQB1 in Mexican patients: A relationship between HLA and gender is suggested

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    <p>Abstract</p> <p>Background</p> <p>Narcolepsy-cataplexy is characterized by excessive daytime sleepiness with recurrent episodes of irresistible sleep, cataplexy, hallucinations and sleep paralysis. Its aetiology is unknown, but it is positively associated with the human leukocyte antigens (HLA) in all studied populations. The purpose of the present study was to investigate the association of HLA class II <it>DRB1</it>/<it>DQB1 </it>alleles with narcolepsy-cataplexy in Mexican Mestizo patients.</p> <p>Methods</p> <p>This is a case-control study of consecutive patients and ethnically matched controls. We included 32 patients diagnosed with typical narcolepsy-cataplexy, of the National Institute of Neurology, of the Institute of Psychiatry and at the Center of Narcolepsy at Stanford University. As healthy controls, 203 Mexican Mestizos were included. <it>DRB1 </it>alleles were identified using sequence based typing. A PCR-SSOP reverse dot blot was used for <it>DQB1 </it>typing. Allele frequency was calculated by direct counting and the significance of the differences was assessed using the Yates Chi square. Odds ratio and confidence intervals were evaluated.</p> <p>Results</p> <p>HLA-<it>DRB1</it>*1501 (OR = 8.2; pc < 0.0001) and <it>DQB1</it>*0602 (OR = 8.4; pc < 0.0001) were found positively associated with narcolepsy. When deleting <it>DQB1</it>*0602+ patients from the analysis, <it>DQB1</it>*0301 was also found increased (OR = 2.7; p = 0.035; pc = NS). <it>DQB1</it>*0602/<it>DQB1</it>*0301 genotype was present in 15.6% of the cases (OR = 11.5; p = 0.00035), conferring a high risk. <it>DRB1</it>*0407 (OR = 0.2; p = 0.016 pc = NS) and <it>DQB1</it>*0302(OR = 0.4; p = 0.017, pc = NS) were found decreased in the patients. The gender stratification analysis showed a higher risk in females carrying <it>DRB1</it>*1501 (OR = 15.8, pc < 0.0001) and <it>DQB1</it>*0602 (OR = 19.8, pc < 0.0001) than in males (OR = 5.0 for both alleles; p = 0.012, pc = NS for <it>DRB1 </it>& p = 0.0012, pc = 0.017 for <it>DQB1</it>). The susceptibility alleles found in Mexicans with narcolepsy are also present in Japanese and Caucasians; <it>DRB1</it>*04 linked protection has also been shown in Koreans. A stronger HLA association is suggested in females, in accordance with the sexual dimorphism claimed previously.</p> <p>Conclusion</p> <p>This knowledge may contribute to a better understanding of the disease pathogenesis in different populations. The evaluation of the risk to develop narcolepsy-cataplexy in carriers of the described alleles/genotypes may also be possible. A larger sample should be analysed in Mexican and in other Hispanic patients to confirm these results.</p

    Effective Rheology of Bubbles Moving in a Capillary Tube

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    We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

    Alignment of the ALICE Inner Tracking System with cosmic-ray tracks

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    37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe

    First measurement of the |t|-dependence of coherent J/ψ photonuclear production

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    The first measurement of the cross section for coherent J/ψ photoproduction as a function of |t|, the square of the momentum transferred between the incoming and outgoing target nucleus, is presented. The data were measured with the ALICE detector in ultra-peripheral Pb–Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02TeV with the J/ψ produced in the central rapidity region |y|<0.8, which corresponds to the small Bjorken-x range (0.3−1.4)×10−3. The measured |t|-dependence is not described by computations based only on the Pb nuclear form factor, while the photonuclear cross section is better reproduced by models including shadowing according to the leading-twist approximation, or gluon-saturation effects from the impact-parameter dependent Balitsky–Kovchegov equation. These new results are therefore a valid tool to constrain the relevant model parameters and to investigate the transverse gluonic structure at very low Bjorken-x.publishedVersio

    First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at √sNN = 5.44 TeV

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    The first measurement of the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV is presented. This result, together with previous HERA Îłp data and γ–Pb measurements from ALICE, describes the atomic number (A) dependence of this process, which is particularly sensitive to nuclear shadowing effects and to the approach to the black-disc limit of QCD at a semi-hard scale. The cross section of the Xe+Xe→ρ0+Xe+Xe process, measured at midrapidity through the decay channel ρ0→π+π−, is found to be dσ/dy=131.5±5.6(stat.)−16.9+17.5(syst.) mb. The ratio of the continuum to resonant contributions for the production of pion pairs is also measured. In addition, the fraction of events accompanied by electromagnetic dissociation of either one or both colliding nuclei is reported. The dependence on A of cross section for the coherent ρ0 photoproduction at a centre-of-mass energy per nucleon of the ÎłA system of WÎłA,n=65 GeV is found to be consistent with a power-law behaviour σ(ÎłA→ρ0A)∝Aα with a slope α=0.96±0.02(syst.). This slope signals important shadowing effects, but it is still far from the behaviour expected in the black-disc limit.publishedVersio
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