An international scoring system for self-reported health complaints in adolescents

Background: Aimed to develop a unitary scoring system for the 'Health Behaviour in school-aged Children' (HBSC) symptom checklist that would facilitate cross-national comparisons and interpretation. Rasch measurement analysis and investigation of differential item functioning (DIF) were conducted. Methods: Data were obtained from the 'WHO collaborative study HBSC 2001/2002'. A total of 162 305 students aged 11, 13 and 15 years from 35 European and North American Countries were surveyed. Unidimensionality of the items and local independence were tested using means of confirmatory factor analysis. DIF across countries, age groups and gender was investigated using a logistic regression procedure. Item and person parameters were estimated according to the Rating Scale Model (RSM). Results: All items proved to be unidimensional. One item displayed noticeable DIF across countries and was discarded. The remaining items were functioning equally across subgroups. The RSM analysis resulted in Rasch model conform item parameter estimation. Infit mean square values between 0.84 and 1.35 revealed acceptable item fit. Conclusion: The control of DIF enables comparable and unbiased assessment of subjective health complaints across countries, age groups and gender. A scoring algorithm could be developed which enables a cross-cultural comparable and interval-scaled assessment of subjective health complaints.publishersversionPeer reviewe

Focal depths and mechanisms of Tohoku-Oki aftershocks from teleseismic P wave modeling

earthquake have a wide range of focal depths and fault plane mechanisms. We constrain the focal depths and focal mechanisms of 69 aftershocks with Mw [ 5.4 by modeling the waveforms of teleseismic P and its trailing near-surface reflections pP and sP. We find that the ‘‘thrust events’ ’ are within 10 km from the plate interface. The dip angles of these thrust events increase with depth from *5 to *25. The ‘‘non-thrust events’ ’ vary from 60 km above to 40 km below the plate interface. Normal and strike-slip events within the overriding plate point to redistribution of stress following the primary great earthquake; however, due to the spatially variable stress change in the Tohoku-Oki earthquake, an understanding of how the mainshock affected the stresses that led to the aftershocks requires accurate knowledge of the aftershock location

Enhanced production of multi-strange hadrons in high-multiplicity proton-proton collisions

At sufficiently high temperature and energy density, nuclear matter undergoes a transition to a phase in which quarks and gluons are not confined: the quark-gluon plasma (QGP)(1). Such an exotic state of strongly interacting quantum chromodynamics matter is produced in the laboratory in heavy nuclei high-energy collisions, where an enhanced production of strange hadrons is observed(2-6). Strangeness enhancement, originally proposed as a signature of QGP formation in nuclear collisions(7), is more pronounced for multi-strange baryons. Several effects typical of heavy-ion phenomenology have been observed in high-multiplicity proton-proton (pp) collisions(8,9), but the enhanced production of multi-strange particles has not been reported so far. Here we present the first observation of strangeness enhancement in high-multiplicity proton-proton collisions. We find that the integrated yields of strange and multi-strange particles, relative to pions, increases significantly with the event charged-particle multiplicity. The measurements are in remarkable agreement with the p-Pb collision results(10,11), indicating that the phenomenon is related to the final system created in the collision. In high-multiplicity events strangeness production reaches values similar to those observed in Pb-Pb collisions, where a QGP is formed.Peer reviewe

D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions root S-NN=5.02 TeV

The azimuthal anisotropy coefficient v(2) of prompt D-0, D+, D*+, and D-s(+) mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair root s(NN)=5.02 TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y| < 0.8, in the transverse momentum interval 1 < p(T) < 24 GeV/c. The measured D-meson v(2) has similar values as that of charged pions. The D-s(+) v(2), measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.Peer reviewe

Production of muons from heavy-flavour hadron decays in p-Pb collisions at root s(NN)=5.02 TeV

The production of muons from heavy-flavour hadron decays in p-Pb collisions at root s(NN) = 5.02 TeV was studied for 2 <p(T) <16 GeV/c with the ALICE detector at the CERN LHC. The measurement was performed at forward (p-going direction) and backward (Pb-going direction) rapidity, in the ranges of rapidity in the centre-of-mass system (cms) 2.03 <y(cms) <3.53 and -4.46 <y(cms) <-2.96, respectively. The production cross sections and nuclear modification factors are presented as a function of transverse momentum (P-T). At forward rapidity, the nuclear modification factor is compatible with unity while at backward rapidity, in the interval 2.5 <p(T) <3.5 GeV/c, it is above unity by more than 2 sigma. The ratio of the forward -to -backward production cross sections is also measured in the overlapping interval 2.96 <|y(cms)| <3.53 and is smaller than unity by 3.7 sigma in 2.5 <p(T) <3.5 GeV/c. The data are described by model calculations including cold nuclear matter effects. (C) 2017 The Author(s). Published by Elsevier B.V.Peer reviewe

Measurement of the production of high-p(T) electrons from heavy-flavour hadron decays in Pb-Pb collisions at root s(NN)=2.76 TeV

Electrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb–Pb collisions at a centre-of-mass of energy sNN=2.76 TeV. The transverse momentum (pT) differential production yields at mid-rapidity were used to calculate the nuclear modification factor RAA in the interval 3<pT<18 GeV/c. The RAA shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb–Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50–80%) collisions is observed. The suppression of electrons in this broad pT interval indicates that both charm and beauty quarks lose energy when they traverse the hot medium formed in Pb–Pb collisions at LHC

Measurement of the production of high-p(T) electrons from heavy-flavour hadron decays in Pb-Pb collisions at root s(NN)=2.76 TeV

Electrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb–Pb collisions at a centre-of-mass of energy sNN=2.76 TeV. The transverse momentum (pT) differential production yields at mid-rapidity were used to calculate the nuclear modification factor RAA in the interval 3<pT<18 GeV/c. The RAA shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb–Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50–80%) collisions is observed. The suppression of electrons in this broad pT interval indicates that both charm and beauty quarks lose energy when they traverse the hot medium formed in Pb–Pb collisions at LHC

Centrality dependence of high-p(T) D-meson suppression in Pb-Pb collisions at root s(NN) = 2.7 6 TeV (vol 2015, 2015)

This is an addendum to the article JHEP 11 (2015) 205 [1]. The figures 3 (right), 4 (right) and 5 are updated with published results on non-prompt J/psi-meson production from the CMS collaboration [2]

Measuring (KSK +/-)-K-0 interactions using Pb-Pb collisions at root S-NN=2.76 TeV

We present the first ever measurements of femtoscopic correlations between the KS0 and K± particles. The analysis was performed on the data from Pb–Pb collisions at sNN=2.76 TeV measured by the ALICE experiment. The observed femtoscopic correlations are consistent with final-state interactions proceeding via the a0(980) resonance. The extracted kaon source radius and correlation strength parameters for KS0K− are found to be equal within the experimental uncertainties to those for KS0K+. Comparing the results of the present study with those from published identical-kaon femtoscopic studies by ALICE, mass and coupling parameters for the a0 resonance are tested. Our results are also compatible with the interpretation of the a0 having a tetraquark structure instead of that of a diquark

Measurement of the production of high-p(T) electrons from heavy-flavour hadron decays in Pb-Pb collisions at root s(NN)=2.76 TeV

Electrons from heavy-flavour hadron decays (charm and beauty) were measured with the ALICE detector in Pb–Pb collisions at a centre-of-mass of energy sNN=2.76 TeV. The transverse momentum (pT) differential production yields at mid-rapidity were used to calculate the nuclear modification factor RAA in the interval 3&lt;pT&lt;18 GeV/c. The RAA shows a strong suppression compared to binary scaling of pp collisions at the same energy (up to a factor of 4) in the 10% most central Pb–Pb collisions. There is a centrality trend of suppression, and a weaker suppression (down to a factor of 2) in semi-peripheral (50–80%) collisions is observed. The suppression of electrons in this broad pT interval indicates that both charm and beauty quarks lose energy when they traverse the hot medium formed in Pb–Pb collisions at LHC