32 research outputs found

    Creativiteit en innovatie : introductie op het thema

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    In deze introductie op het themanummer van Gedrag & Organisatie schetsen we kort de stand van zaken binnen het wetenschappelijk onderzoek naar creativiteit en innovatie. Vervolgens introduceren we de zes bijdragen van dit themanummer. We sluiten af met een korte conclusie

    Reduction of conditioned avoidance via contingency reversal

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    There is an increased interest in how excessive avoidance can diminish. Avoidance reduction is typically tested by using Extinction with Response Prevention (ExRP) protocols, where feared stimuli are presented without any aversive outcome while avoidance is prevented. These effects, however, often do not persist. Here, we tested whether pairing an avoidance response with the presence of an aversive event would reduce avoidance more than ExRP. Participants (N = 58) first saw a picture of a square (A) being paired with a shock whereas another picture of a square (B) not being paired with a shock. Then, they learned to press a button during the presentation of A to avoid the shock. Afterwards, the ExRP group saw unreinforced presentations of A and B without being able to press the avoidance button, whereas the Contingency Reversal group (ConR) received a shock whenever they pressed the button in presence of A. In the test phase, participants saw unreinforced presentations of A and B. Results showed that after successful acquisition of fear and avoidance, in the test phase the ConR group avoided A less often than did the ExRP group. Research on contingency reversal could prove helpful for developing avoidance reduction protocols

    Stable Anxiety and Depression Trajectories in Late Adolescence for Oral Contraceptive Users

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    Background: The use of oral contraceptives (OCs) has been associated with increased incidences of anxiety and depression, for which adolescents seem to be particularly vulnerable. Rather than looking at singular outcomes, we examined whether OC use is associated with depressive and anxiety symptom trajectories from early adolescence into early adulthood. Materials and Methods: Data from 178 girls were drawn from the Research on Adolescent Development and Relationships (RADAR-Y) younger cohort study. We used assessments on 9 waves from age 13 until 24. Developmental trajectories of ratings on the Reynolds Adolescent Depression Scale (RADS-2) and the Screen for Child Anxiety Related Emotional Disorders (SCARED) were compared between never and ever users of OCs. Results: Never users showed increases in depressive and anxiety symptoms in late adolescence, whereas OC users showed a stable level of symptoms throughout adolescence. This effect remained after adjusting for baseline differences between groups in romantic relationships, sexual debut, educational level, smoking, drinking, and drug use. Age of OC use onset did not significantly predict symptom development. Conclusions: OC use in adolescence was related to an altered developmental trajectory of internalizing symptoms, in which OC users did not show an increase in depressive and anxiety symptoms in late adolescence, whereas never users did. The question remains whether this altered symptom trajectory can be considered a protective effect of OC use on psychopathology. Additional research is needed to improve our understanding of the long-term consequences of OC use on mental health

    Stable Anxiety and Depression Trajectories in Late Adolescence for Oral Contraceptive Users

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    Background: The use of oral contraceptives (OCs) has been associated with increased incidences of anxiety and depression, for which adolescents seem to be particularly vulnerable. Rather than looking at singular outcomes, we examined whether OC use is associated with depressive and anxiety symptom trajectories from early adolescence into early adulthood. Materials and Methods: Data from 178 girls were drawn from the Research on Adolescent Development and Relationships (RADAR-Y) younger cohort study. We used assessments on 9 waves from age 13 until 24. Developmental trajectories of ratings on the Reynolds Adolescent Depression Scale (RADS-2) and the Screen for Child Anxiety Related Emotional Disorders (SCARED) were compared between never and ever users of OCs. Results: Never users showed increases in depressive and anxiety symptoms in late adolescence, whereas OC users showed a stable level of symptoms throughout adolescence. This effect remained after adjusting for baseline differences between groups in romantic relationships, sexual debut, educational level, smoking, drinking, and drug use. Age of OC use onset did not significantly predict symptom development. Conclusions: OC use in adolescence was related to an altered developmental trajectory of internalizing symptoms, in which OC users did not show an increase in depressive and anxiety symptoms in late adolescence, whereas never users did. The question remains whether this altered symptom trajectory can be considered a protective effect of OC use on psychopathology. Additional research is needed to improve our understanding of the long-term consequences of OC use on mental health

    Comparison between simulated and observed LHC beam backgrounds in the ATLAS experiment at Ebeam =4 TeV

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    Results of dedicated Monte Carlo simulations of beam-induced background (BIB) in the ATLAS experiment at the Large Hadron Collider (LHC) are presented and compared with data recorded in 2012. During normal physics operation this background arises mainly from scattering of the 4 TeV protons on residual gas in the beam pipe. Methods of reconstructing the BIB signals in the ATLAS detector, developed and implemented in the simulation chain based on the \textscFluka Monte Carlo simulation package, are described. The interaction rates are determined from the residual gas pressure distribution in the LHC ring in order to set an absolute scale on the predicted rates of BIB so that they can be compared quantitatively with data. Through these comparisons the origins of the BIB leading to different observables in the ATLAS detectors are analysed. The level of agreement between simulation results and BIB measurements by ATLAS in 2012 demonstrates that a good understanding of the origin of BIB has been reached

    Search for long-lived neutral particles in pp collisions at s√=13 TeV that decay into displaced hadronic jets in the ATLAS calorimeter

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    This paper describes a search for pairs of neutral, long-lived particles decaying in the ATLAS calorimeter. Long-lived particles occur in many extensions to the Standard Model and may elude searches for new promptly decaying particles. The analysis considers neutral, long-lived scalars with masses between 5 and 400 GeV, produced from decays of heavy bosons with masses between 125 and 1000 GeV, where the long-lived scalars decay into Standard Model fermions. The analysis uses either 10.8 fb−1 or 33.0 fb−1 of data (depending on the trigger) recorded in 2016 at the LHC with the ATLAS detector in proton–proton collisions at a centre-of-mass energy of 13 TeV. No significant excess is observed, and limits are reported on the production cross section times branching ratio as a function of the proper decay length of the long-lived particles

    Prompt and non-prompt J/psi elliptic flow in Pb plus Pb collisions at root S-NN=5.02 TeV with the ATLAS detector

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    The elliptic flow of prompt and non-prompt J/ \u3c8 was measured in the dimuon decay channel in Pb+Pb collisions at sNN=5.02 TeV with an integrated luminosity of 0.42nb-1 with the ATLAS detector at the LHC. The prompt and non-prompt signals are separated using a two-dimensional simultaneous fit of the invariant mass and pseudo-proper decay time of the dimuon system from the J/ \u3c8 decay. The measurement is performed in the kinematic range of dimuon transverse momentum and rapidity 9 < pT< 30 GeV , | y| < 2 , and 0\u201360% collision centrality. The elliptic flow coefficient, v2, is evaluated relative to the event plane and the results are presented as a function of transverse momentum, rapidity and centrality. It is found that prompt and non-prompt J/ \u3c8 mesons have non-zero elliptic flow. Prompt J/ \u3c8v2 decreases as a function of pT, while for non-prompt J/ \u3c8 it is, with limited statistical significance, consistent with a flat behaviour over the studied kinematic region. There is no observed dependence on rapidity or centrality

    Search for squarks and gluinos in final states with hadronically decaying tau-leptons, jets, and missing transverse momentum using pp collisions at root s = 13 TeV with the ATLAS detector

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    A search for supersymmetry in events with large missing transverse momentum, jets, and at least one hadronically decaying τ-lepton is presented. Two exclusive final states with either exactly one or at least two τ-leptons are considered. The analysis is based on proton-proton collisions at √s=13  TeV corresponding to an integrated luminosity of 36.1  fb⁻¹ delivered by the Large Hadron Collider and recorded by the ATLAS detector in 2015 and 2016. No significant excess is observed over the Standard Model expectation. At 95% confidence level, model-independent upper limits on the cross section are set and exclusion limits are provided for two signal scenarios: a simplified model of gluino pair production with τ-rich cascade decays, and a model with gauge-mediated supersymmetry breaking (GMSB). In the simplified model, gluino masses up to 2000 GeV are excluded for low values of the mass of the lightest supersymmetric particle (LSP), while LSP masses up to 1000 GeV are excluded for gluino masses around 1400 GeV. In the GMSB model, values of the supersymmetry-breaking scale are excluded below 110 TeV for all values of tanβ in the range 2 ≤ tanβ ≤ 60, and below 120 TeV for tanβ > 30.M. Aaboud … D. Duvnjak … P. Jackson … J.L. Oliver … A. Petridis … A. Qureshi … A.S. Sharma … M.J. White … et al. [The ATLAS Collaboration

    Genetics in experimental psychopathology: From laboratory models to therapygenetics. Where do we go from here?

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    Experimental psychopathology is the application of experimental methods to the study of psychopathology and its underlying processes. The study of individual differences in the development, maintenance and/or relapse of psychopathology is currently at the forefront of research. Stressful events are known to exert a substantial impact on our lives. Why however, do some people react in an extremely adaptive way, while others develop pathology in the aftermath of a trauma? One particularly interesting individual differences factor is genetic makeup and the aim of this paper is to review the current state of the art of genetics in experimental psychopathology which is illustrated by using fear conditioning as an exemplary model in the study of mechanisms underlying anxiety. We identify and discuss current challenges of the field and provide recommendations on how these can be met. In addition, criteria for experimental models of psychopathology as well as future directions are discussed

    The impact of cue learning, trait anxiety and genetic variation in the serotonin 1A receptor on contextual fear

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    In everyday life, aversive events are usually associated with certain predictive cues. Normally, the acquisition of these contingencies enables organisms to appropriately respond to threat. Presence of a threat cue clearly signals 'danger', whereas absence of such cues signals a period of 'safety'. Failure to identify threat cues may lead to chronic states of anxious apprehension in the context in which the threat has been imminent, which may be instrumental in the pathogenesis of anxiety disorders.In this study, existing data from 150 healthy volunteers in a cue and context virtual reality fear conditioning paradigm were reanalyzed. The aim was to further characterize the impact of cue acquisition and trait anxiety, and of a single nucleotide polymorphism in the serotonin 1A receptor gene (5-HTR1A, rs6295), on cued fear and contextual anxiety before and after fear contingencies were explicitly introduced. Fear conditioned responding was quantified with fear potentiation of the eyeblink startle reflex and subjective fear ratings.First, we replicated previous findings that the inability to identify danger cues during acquisition leads to heightened anxious apprehension in the threat context. Second, in subjects who did not identify the danger cue initially, contextual fear was associated with trait anxiety after the contingencies were explicitly instructed. Third, genetic variability within 5-HTR1A (rs6295) was associated with contextual fear independent of awareness or trait anxiety.These findings confirm that failure to acquire cue contingencies impacts contextual fear responding, in association with trait anxiety. The observed 5-HTR1A effect is in line with models of anxiety, but needs further replication
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