31,978 research outputs found

    Prevalence of deliberate self harm and attempted suicide within contemporary Goth youth subculture: longitudinal cohort study

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    <b>Objective</b> To investigate whether deliberate self harm is associated with contemporary Goth youth subculture. <b>Design</b> Longitudinal cohort study. <b>Setting</b> School and community based study of young people living in the Central Clydeside Conurbation, Scotland. <b>Participants</b> 1258 people aged 19, surveyed in 2002-4 and followed-up since age 11 (1994). <b>Main outcome measures</b> Lifetime prevalence of self harm and attempted suicide and their association with Goth youth subculture, before and after adjusting for confounders. <b>Results</b> Identification as belonging to the Goth subculture was strongly associated with lifetime self harm and attempted suicide, with a prevalence of 53% and 47%, respectively among the most highly identified group, and evidence for a dose-response relation. Adjusting for potential confounders did not significantly attenuate this association. Analysis of other youth subcultures showed that this effect was primarily associated with Goth subculture. <b>Conclusions</b> Identification as belonging to the Goth subculture was the best predictor of self harm and attempted suicide. Although based on small numbers, additional longitudinal analysis suggests both selection and modelling mechanisms are involved, selection mechanisms possibly being more likely

    Mining Missing Hyperlinks from Human Navigation Traces: A Case Study of Wikipedia

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    Hyperlinks are an essential feature of the World Wide Web. They are especially important for online encyclopedias such as Wikipedia: an article can often only be understood in the context of related articles, and hyperlinks make it easy to explore this context. But important links are often missing, and several methods have been proposed to alleviate this problem by learning a linking model based on the structure of the existing links. Here we propose a novel approach to identifying missing links in Wikipedia. We build on the fact that the ultimate purpose of Wikipedia links is to aid navigation. Rather than merely suggesting new links that are in tune with the structure of existing links, our method finds missing links that would immediately enhance Wikipedia's navigability. We leverage data sets of navigation paths collected through a Wikipedia-based human-computation game in which users must find a short path from a start to a target article by only clicking links encountered along the way. We harness human navigational traces to identify a set of candidates for missing links and then rank these candidates. Experiments show that our procedure identifies missing links of high quality

    E_11 and M Theory

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    We argue that eleven dimensional supergravity can be described by a non-linear realisation based on the group E_{11}. This requires a formulation of eleven dimensional supergravity in which the gravitational degrees of freedom are described by two fields which are related by duality. We show the existence of such a description of gravity.Comment: 21 pages, some typos corrected and two references adde

    Voyager 1 imaging and IRIS observations of Jovian methane absorption and thermal emission: Implications for cloud structure

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    Images from three filters of the Voyager 1 wide angle camera are used to measure the continuum reflectivity and spectral gradient near 6000 A and the 6190 A band methane/continuum ratio for a variety of cloud features in Jupiter's atmosphere. The dark barge features in the North Equatorial Belt have anomalously strong positive continuum spectral gradients suggesting unique composition. Methane absorption is shown at unprecedented spatial scales for the Great Red Spot and its immediate environment, for a dark barge feature in the North Equatorial Belt, and for two hot spot and plume regions in the North Equatorial Belt. Methane absorption and five micrometer emission are correlated in the vicinity of the Great Red Spot but are anticorrelated in one of the plume hot spot regions. Methane absorption and simultaneous maps of five micrometer brightness temperature is quantitatively compared to realistic cloud structure models which include multiple scattering at five micrometer as well as in the visible. Variability in H2 quadrupole lines are also investigated

    Remarks on E11 approach

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    We consider a few topics in E11E_{11} approach to superstring/M-theory: even subgroups (Z2Z_2 orbifolds) of EnE_{n}, n=11,10,9 and their connection to Kac-Moody algebras; EE11EE_{11} subgroup of E11E_{11} and coincidence of one of its weights with the l1l_1 weight of E11E_{11}, known to contain brane charges; possible form of supersymmetry relation in E11E_{11}; decomposition of l1l_1 w.r.t. the SO(10,10)SO(10,10) and its square root at first few levels; particle orbit of l1⋉E11l_1 \ltimes E_{11}. Possible relevance of coadjoint orbits method is noticed, based on a self-duality form of equations of motion in E11E_{11}.Comment: Two references adde

    Observation of a cyclotron harmonic spike in microwave-induced resistances in ultraclean GaAs/AlGaAs quantum wells

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    We report the observation of a colossal, narrow resistance peak that arises in ultraclean (mobility 3X10^7cm^2/Vs) GaAs/AlGaAs quantum wells (QWs) under millimeterwave irradiation and a weak magnetic field. Such a spike is superposed on the 2nd harmonic microwave-induced resistance oscillations (MIRO) but having an amplitude > 300% of the MIRO, and a typical FWHM ~50 mK, comparable with the Landau level width. Systematic studies show a correlation between the spike and a pronounced negative magnetoresistance in these QWs, suggesting a mechanism based on the interplay of strong scatterers and smooth disorder. Alternatively, the spike may be interpreted as a manifestation of quantum interference between the quadrupole resonance and the higher-order cyclotron transition in well-separated Landau levels.Comment: 4pages, 4figure

    The Principal Axis of the Virgo Cluster

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    Using accurate distances to individual Virgo cluster galaxies obtained by the method of Surface Brightness Fluctuations, we show that Virgo's brightest ellipticals have a remarkably collinear arrangement in three dimensions. This axis, which is inclined by 10 to 15 degrees from the line of sight, can be traced to even larger scales where it appears to join a filamentary bridge of galaxies connecting Virgo to the rich cluster Abell 1367. The orientations of individual Virgo ellipticals also show some tendency to be aligned with the cluster axis, as does the jet of the supergiant elliptical M87. These results suggest that the formation of the Virgo cluster, and its brightest member galaxies, have been driven by infall of material along the Virgo-A1367 filament.Comment: 8 pages, 4 figures, accepted for publication in ApJ Letter
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