550 research outputs found

    Who's afraid of the big bad wolf: a prospective paradigm to test Rachman's indirect pathways in children

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    Rachman's theory [The conditioning theory of fear insition: a critical examination. Behav. Res. Ther. 15 (1977) 375–387] of fear acquisition suggests that fears and phobias can be acquired through three pathways: direct conditioning, vicarious learning and information/instruction. Although retrospective studies have provided some evidence for these pathways in the development of phobias during childhood [see King, Gullone, & Ollendick, Etiology of childhood phobias: current status of Rachman's three pathway's theory. Behav. Res. Ther. 36 (1998) 297–309 for a review], these studies have relied on long-term past memories of adult phobics or their parents. The current study was aimed towards developing a paradigm in which the plausibility of Rachman's indirect pathways could be investigated prospectively. In Experiment 1, children aged between 7 and 9 were presented with two types of information about novel stimuli (two monsters): video information and verbal information in the form of a story. Fear-related beliefs about the monsters changed significantly as a result of verbal information but not video information. Having established an operational paradigm, Experiment 2 looked at whether the source of verbal information had an effect on changes in fear-beliefs. Using the same paradigm, information about the monsters was provided by either a teacher, an adult stranger or a peer, or no information was given. Again, verbal information significantly changed fear-beliefs, but only when the information came from an adult. The role of information in the acquisition of fear and maintenance of avoidant behaviour is discussed with reference to modern conditioning theories of fear acquisition

    Generalized Integer Partitions, Tilings of Zonotopes and Lattices

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    In this paper, we study two kinds of combinatorial objects, generalized integer partitions and tilings of two dimensional zonotopes, using dynamical systems and order theory. We show that the sets of partitions ordered with a simple dynamics, have the distributive lattice structure. Likewise, we show that the set of tilings of zonotopes, ordered with a simple and classical dynamics, is the disjoint union of distributive lattices which we describe. We also discuss the special case of linear integer partitions, for which other dynamical systems exist. These results give a better understanding of the behaviour of tilings of zonotopes with flips and dynamical systems involving partitions.Comment: See http://www.liafa.jussieu.fr/~latapy

    EFFECTS OF SUPPLEMENTATION WITH CREATINE MONOHYDRATE AND BETA-ALANINE, ALONE OR COMBINED, ON REPEATED SPRINT PERFORMANCE AND PHYSIOLOGICAL PARAMETERS IN AMATEUR TEAM AND RACKET SPORT PLAYERS

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    The purpose of this study was to compare the combined effects of creatine monohydrate (Cr) and beta- alanine (BA) with their isolated use on performance and physiological parameters during repeated sprint sequences (RSS). Forty-four male (n=34) and female (n=10) amateur team- and racket sport players (25.1±3.1 years; 175.2±9.8 cm; 76.0±10.3 kg; 15.2±6.8% body fat) performed ten repetitions of 6-s sprints with departure every 30 s, before and after a 28-day supplementation period with either Cr (n=11, 5 g‧day-1), BA (n=10, 6 g‧day-1), combined Cr and BA (n=12, 5 g‧day-1 of Cr plus 6g‧day-1 of BA) or placebo (11 g‧day-1 of rice flour). Peak (PP) and mean power (MP), performance decrement (%Dec), heart rate (HR), blood lactate concentration (LA) and perceived exertion (RPE) were measured. Analyses of variance (ANOVA) were used to determine the effects of groups (Cr, BA, CrBA, P), sprint number (1 to 10), and time (pre- vs. post-supplementation) on all variables. A significant increase in PP was shown in the post- compared to the pre-supplementation in Cr (+5.2%) and BA (+5.2%) groups only (p<.05), and significant decreases in MP in all groups (3.7% to 6.4%, p<.05), except BA. %Dec was significantly decreased post-supplementation in the Cr group only (17.4%, p<.05). No effects were shown on HR, RPE and LA (p<.05). These results show no additional benefits of the combination of Cr and BA on RSS performance and suggest that longer sprint or total exercise duration might be necessary to observe the benefits of the combined supplementation

    Is this photograph taken? - The active (act of) collaboration with photography

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    Over more than thirty years of commercial and fine art photographic practice, I have often noticed remarkable disparities between the scenes, objects, events or moments ‘out there’ I had attempted to record – and the images within the resulting photographs. These (sometimes subtle, sometimes profound, but rarely anticipatable) disparities between what I had seen and what the photograph shows me offer the tantalising suggestion that there may be something else going on here – but something which the popular conception of photography may hinder our ability to recognise. This article explores the implications of four central assumptions implicit within the popular conception of photography which may impede new ways of thinking about photographic practice. Supported by a number of photographs that depict scenes, events and ‘moments’ which were not ‘taken’ but were created by the act of photographing them, I will suggest that new opportunities for practice may be available by ‘re-imagining’ the practice of photography as an active – or, as an act of – collaboration between medium and practitioner

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

    Standalone vertex nding in the ATLAS muon spectrometer

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    A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
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