Die Bedeutung von internetspezifischen maladaptiven Kognitionen, Einsamkeit und sozialer Isolation für problematischen Internetgebrauch

Die Bedeutung von internetspezifischen maladaptiven Kognitionen, Einsamkeit und sozialer Isolation für problematischen Internetgerbauch Zielsetzung: Internetspezifische maladaptive Kognitionen spielen in der Entwicklung und im Verlauf eines problematischen Internetgebrauchs (PIG) eine wichtige Rolle (Davis, 2001). Das Ziel dieser Studie war die Feststellung der Prävalenz für problematischen Internetgebrauch in einer deutschsprachigen Stichprobe. Außerdem interessierten die Effekte von internetspezifischen maladaptiven Kognitionen, Einsamkeit und sozialer Unterstützung auf PIG. Methoden: 2216 Internetnutzer/innen wurden in einer Online-Untersuchung befragt. Folgende Instrumente kamen zum Einsatz: “ISS-20” (Hahn & Jerusalem, 2001), die “OCS-Online Cognition Scale” (Davis, Flett & Besser, 2002) und die "MCI-Maladaptive Cognitions concerning the Internet" (Lehenbauer, 2006). 951 Teilnehmer/innen der Stichprobe wurde der “MEF – Multidimensionaler Einsamkeits-Fragebogen” (Schwab, 1997) und ein Fragebogen zur wahrgenommenen sozialen Unterstützung (Piffl, 2010) vorgegeben. Ergebnisse: Problematischer Internetgebrauch wurde für 2,89% der Stichprobe ermittelt. Beide Instrumente zur Erfassung der internetspezifischen maladaptiven Kognitionen zeigten höchst signifikante Effekte (OCS: F (2, 621,31) = 888,86, p < 0,001 (η² = 0,74); MCI: F (2, 922,92) = 78,71, p < 0,001 (η² = 0,15)). Höhere Einsamkeitswerte gingen mit höheren Werten in problematischem Internetgebrauch einher (M = 43,70, SD = 11,81). Personen mit PIG zeigten höchst signifikant niedrigere Werte in wahrgenommener sozialer Unterstützung (M = 3,44, SD = 1,10). Zusammenfassung: Die Ergebnisse dieser Studie unterstützen die Hypothese, dass internetspezifische maladaptive Kognitionen und Einsamkeit essentielle Rollen in problematischem Internetverhalten spielen. Internetnutzer/innen mit PIG nehmen weniger soziale Unterstützung aus ihrem sozialen Umfeld wahr.The Meaning of Internetspecific Maladaptive Cognitions, Loneliness and Social Isolation for Problematical Internet Use Objectives: Maladaptive cognitions play a significant role in the development and maintenance of problematic Internet use (PIU) (Davis, 2001). Aims of the study were to examine the prevalence rates of PIU in a German speaking online sample including the effects of maladaptive cognitions, possible influences of loneliness and social support. Methods: 2216 Internet users were surveyed using an online questionnaire consisting of questions regarding Internet use, the “ISS-20” (Hahn & Jerusalem, 2001), the “OCS-Online Cognition Scale” (Davis, Flett & Besser, 2002) and the "MCI-Maladaptive Cognitions concerning the Internet" (Lehenbauer, 2006). 951 users of this sample were asked the “MDLS – Multidimensional Loneliness Scale” (Schwab, 1997) and a questionnaire measuring social support (Piffl, 2010). Results: PIU was found for 2,89% of the participants and both instruments measuring maladaptive cognitions showed highly significant effects (OCS: F (2, 621,31) = 888,86, p < 0,001 (η² = 0,74); MCI: F (2, 922,92) = 78,71, p < 0,001 (η² = 0,15)). Higher values in loneliness included a larger extent of PIU (M = 43,70 SD = 11,81). In addition participants with PIU showed highly significant lower degree of perceived social support (M = 3,44, SD = 1,10). Conclusion: The findings of this study support the hypothesis that maladaptive cognitions and loneliness both play essential roles regarding problematic Internet behaviours. Internet users with PIU perceive lower social support from their social network

Galactic Archaeology with CoRoT and APOGEE: Creating mock observations from a chemodynamical model

In a companion paper, we have presented the combined asteroseismic-spectroscopic dataset obtained from CoRoT lightcurves and APOGEE infra-red spectra for 678 solar-like oscillating red giants in two fields of the Galactic disc (CoRoGEE). We have measured chemical abundance patterns, distances, and ages of these field stars which are spread over a large radial range of the Milky Way's disc. Here we show how to simulate this dataset using a chemodynamical Galaxy model. We also demonstrate how the observation procedure influences the accuracy of our estimated ages.Comment: 5 pages, 6 figures. To appear in Astronomische Nachrichten, special issue "Reconstruction the Milky Way's History: Spectroscopic surveys, Asteroseismology and Chemo-dynamical models", Guest Editors C. Chiappini, J. Montalb\'an, and M. Steffe

Chemical gradients in the Milky Way from the RAVE data: II. Giant stars

Aims. We provide new constraints on the chemo-dynamical models of the Milky Way by measuring the radial and vertical chemical gradients for the elements Mg, Al, Si, Ti, and Fe in the Galactic disc and the gradient variations as a function of the distanc

Constraining the Galaxy's dark halo with RAVE stars

We use the kinematics of $\sim200\,000$ giant stars that lie within $\sim 1.5$ kpc of the plane to measure the vertical profile of mass density near the Sun. We find that the dark mass contained within the isodensity surface of the dark halo that passes through the Sun ($(6\pm0.9)\times10^{10}\,\mathrm{M_\odot}$), and the surface density within $0.9$ kpc of the plane ($(69\pm10)\,\mathrm{M_\odot\,pc^{-2}}$) are almost independent of the (oblate) halo's axis ratio $q$. If the halo is spherical, 46 per cent of the radial force on the Sun is provided by baryons, and only 4.3 per cent of the Galaxy's mass is baryonic. If the halo is flattened, the baryons contribute even less strongly to the local radial force and to the Galaxy's mass. The dark-matter density at the location of the Sun is $0.0126\,q^{-0.89}\,\mathrm{M_\odot\,pc^{-3}}=0.48\,q^{-0.89}\,\mathrm{GeV\,cm^{-3}}$. When combined with other literature results we find hints for a mildly oblate dark halo with $q \simeq 0.8$. Our value for the dark mass within the solar radius is larger than that predicted by cosmological dark-matter-only simulations but in good agreement with simulations once the effects of baryonic infall are taken into account. Our mass models consist of three double-exponential discs, an oblate bulge and a Navarro-Frenk-White dark-matter halo, and we model the dynamics of the RAVE stars in the corresponding gravitational fields by finding distribution functions $f(\mathbf{J})$ that depend on three action integrals. Statistical errors are completely swamped by systematic uncertainties, the most important of which are the distance to the stars in the photometric and spectroscopic samples and the solar distance to the Galactic centre. Systematics other than the flattening of the dark halo yield overall uncertainties $\sim 15$ per cent.Comment: 20 pages, 17 figures, accepted for publication in MNRA

Spectroscopic signatures of extratidal stars around the globular clusters NGC 6656 (M 22), NGC 3201, and NGC 1851 from RAVE

Context. Stellar population studies of globular clusters have suggested that the brightest clusters in the Galaxy might actually be the remnant nuclei of dwarf spheroidal galaxies. If the present Galactic globular clusters formed within larger stellar systems, they are likely to be surrounded by extratidal halos and/or tails made up of stars that were tidally stripped from their parent systems. Aims. The stellar surroundings around globular clusters are therefore one of the best places to look for the remnants of an ancient dwarf galaxy. Here an attempt is made to search for tidal debris around the supernovae enriched globular clusters M? 22 and NGC 1851, as well as the kinematically unique cluster NGC 3201. Methods. The stellar parameters from the RAdial Velocity Experiment (RAVE) are used to identify stars with the RAVE metallicities, radial velocities, and elemental abundances that are consistent with the abundance patterns and properties of the stars in M? 22, NGC 1851, and NGC 3201. Results. Discovery of RAVE stars that may be associated with M? 22 and NGC 1851 are reported, some of which are at projected distances ∼10 degrees away from the core of these clusters. Numerous RAVE stars associated with NGC 3201 suggest that either the tidal radius of this cluster is underestimated or that there are some unbound stars extending a few arc minutes from the edge of the cluster's radius. No other extratidal stars associated with NGC 3201 could be identified. The bright magnitudes of the RAVE stars make them easy targets for high-resolution follow-up observations, eventually allowing further chemical tagging to solidify (or exclude) stars outside the tidal radius of the cluster as tidal debris. In both our radial velocity histograms of the regions surrounding NGC 1851 and NGC 3201, a peak of stars at ∼230 km? s-1 is seen, consistent with extended tidal debris from ω Centauri