74 research outputs found

    Acute low back pain – a cross sectional study: Fear-avoidance beliefs and associated characteristics

    Get PDF
    Abstract Background/Aim: Fear-avoidance beliefs (FAB) is exsessive fear of movements that may lead to movement avoidance and contribute to maintenance of LBP. The aim of the study was (i) to identify the percentage of fear-avoidance beliefs (FAB) in patients with acute low back pain (ALBP) and (ii) find any association that may exist between demographic variables, pain and FAB in the sample. Design: The study is a cross sectional survey with a strategic sample. Material: 115 patients between 20 and 70 years of age with acute (less than 12 weeks) low back pain recruited from physiotherapists in outpatient clinics in Norway in the period November 2006 to February 2007. Method: A questionnaire including questions on fear-avoidance beliefs (FABQ) was used. The questionnaire has two parts with five questions about Physical Activities (FABQ-PA) and 11 questions about work related issues. The scores go from 0-6 where 6 is worst. No cutoff values are indicates in the questionnaire, the cut values in the article are quoted from other authors. The patients were also asked for demographic variables and pain. Result: 115 patients participated in the survey: 85 percent answered the FABQ-W part and 20.4 per cent of these had high scores at a cutoff >29. In total 95 per cent answered the FABQ-PA part and 32.1 per cent of these had high scores at a cutoff >14. Mean scores of FABQ-W were 18.3 (10.9) and FABQ-PA 12.3 (5.8). Patients with lowest level of education were significantly associated with high scores on FABQ-W. Conclusion: Increased pain at present (current pain) was significantly associated with high score on the FABQ-PA. Further, being on sick leave and having attained the lowest level of education were independently associated with having high FABQ-W to a significant degree. Keywords: Acute low back pain, fear-avoidance beliefs, cutoff score, formal education

    Red Queen Coevolution on Fitness Landscapes

    Full text link
    Species do not merely evolve, they also coevolve with other organisms. Coevolution is a major force driving interacting species to continuously evolve ex- ploring their fitness landscapes. Coevolution involves the coupling of species fit- ness landscapes, linking species genetic changes with their inter-specific ecological interactions. Here we first introduce the Red Queen hypothesis of evolution com- menting on some theoretical aspects and empirical evidences. As an introduction to the fitness landscape concept, we review key issues on evolution on simple and rugged fitness landscapes. Then we present key modeling examples of coevolution on different fitness landscapes at different scales, from RNA viruses to complex ecosystems and macroevolution.Comment: 40 pages, 12 figures. To appear in "Recent Advances in the Theory and Application of Fitness Landscapes" (H. Richter and A. Engelbrecht, eds.). Springer Series in Emergence, Complexity, and Computation, 201

    Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

    Full text link
    We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

    Search for electroweak production of single top quarks in ppˉp\bar{p} collisions.

    Get PDF
    We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

    Get PDF
    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at √s = 13 TeV with the ATLAS detector

    Get PDF
    A combination of searches for new heavy spin-1 resonances decaying into diferent pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at √s = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, tt¯, and tb) or third-generation leptons (τν and τ τ ) are included in this kind of combination for the frst time. A simplifed model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confdence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Searches for exclusive Higgs boson decays into D⁎γ and Z boson decays into D0γ and Ks0γ in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    Searches for exclusive decays of the Higgs boson into D⁎γ and of the Z boson into D0γ and Ks0γ can probe flavour-violating Higgs boson and Z boson couplings to light quarks. Searches for these decays are performed with a pp collision data sample corresponding to an integrated luminosity of 136.3 fb−1 collected at s=13TeV between 2016–2018 with the ATLAS detector at the CERN Large Hadron Collider. In the D⁎γ and D0γ channels, the observed (expected) 95% confidence-level upper limits on the respective branching fractions are B(H→D⁎γ)<1.0(1.2)×10−3, B(Z→D0γ)<4.0(3.4)×10−6, while the corresponding results in the Ks0γ channel are B(Z→Ks0γ)<3.1(3.0)×10−6

    Measurement of vector boson production cross sections and their ratios using pp collisions at √s = 13.6 TeV with the ATLAS detector

    Get PDF
    Abstract available from publisher's website

    Beam-induced backgrounds measured in the ATLAS detector during local gas injection into the LHC beam vacuum

    Get PDF
    Inelastic beam-gas collisions at the Large Hadron Collider (LHC), within a few hundred metres of the ATLAS experiment, are known to give the dominant contribution to beam backgrounds. These are monitored by ATLAS with a dedicated Beam Conditions Monitor (BCM) and with the rate of fake jets in the calorimeters. These two methods are complementary since the BCM probes backgrounds just around the beam pipe while fake jets are observed at radii of up to several metres. In order to quantify the correlation between the residual gas density in the LHC beam vacuum and the experimental backgrounds recorded by ATLAS, several dedicated tests were performed during LHC Run 2. Local pressure bumps, with a gas density several orders of magnitude higher than during normal operation, were introduced at different locations. The changes of beam-related backgrounds, seen in ATLAS, are correlated with the local pressure variation. In addition the rates of beam-gas events are estimated from the pressure measurements and pressure bump profiles obtained from calculations. Using these rates, the efficiency of the ATLAS beam background monitors to detect beam-gas events is derived as a function of distance from the interaction point. These efficiencies and characteristic distributions of fake jets from the beam backgrounds are found to be in good agreement with results of beam-gas simulations performed with theFluka Monte Carlo programme

    Acute low back pain – a cross sectional study: Fear-avoidance beliefs and associated characteristics

    No full text
    Abstract Background/Aim: Fear-avoidance beliefs (FAB) is exsessive fear of movements that may lead to movement avoidance and contribute to maintenance of LBP. The aim of the study was (i) to identify the percentage of fear-avoidance beliefs (FAB) in patients with acute low back pain (ALBP) and (ii) find any association that may exist between demographic variables, pain and FAB in the sample. Design: The study is a cross sectional survey with a strategic sample. Material: 115 patients between 20 and 70 years of age with acute (less than 12 weeks) low back pain recruited from physiotherapists in outpatient clinics in Norway in the period November 2006 to February 2007. Method: A questionnaire including questions on fear-avoidance beliefs (FABQ) was used. The questionnaire has two parts with five questions about Physical Activities (FABQ-PA) and 11 questions about work related issues. The scores go from 0-6 where 6 is worst. No cutoff values are indicates in the questionnaire, the cut values in the article are quoted from other authors. The patients were also asked for demographic variables and pain. Result: 115 patients participated in the survey: 85 percent answered the FABQ-W part and 20.4 per cent of these had high scores at a cutoff >29. In total 95 per cent answered the FABQ-PA part and 32.1 per cent of these had high scores at a cutoff >14. Mean scores of FABQ-W were 18.3 (10.9) and FABQ-PA 12.3 (5.8). Patients with lowest level of education were significantly associated with high scores on FABQ-W. Conclusion: Increased pain at present (current pain) was significantly associated with high score on the FABQ-PA. Further, being on sick leave and having attained the lowest level of education were independently associated with having high FABQ-W to a significant degree. Keywords: Acute low back pain, fear-avoidance beliefs, cutoff score, formal education
    corecore