2,196 research outputs found
Feasibility of the STarT back screening tool in chiropractic clinics: a cross-sectional study of patients with low back pain
The STarT back screening tool (SBT) allocates low back pain (LBP) patients into three risk groups and is intended to assist clinicians in their decisions about choice of treatment. The tool consists of domains from larger questionnaires that previously have been shown to be predictive of non-recovery from LBP. This study was performed to describe the distribution of depression, fear avoidance and catastrophising in relation to the SBT risk groups. A total of 475 primary care patients were included from 19 chiropractic clinics. They completed the SBT, the Major Depression Inventory (MDI), the Fear Avoidance Beliefs Questionnaire (FABQ), and the Coping Strategies Questionnaire. Associations between the continuous scores of the psychological questionnaires and the SBT were tested by means of linear regression, and the diagnostic performance of the SBT in relation to the other questionnaires was described in terms of sensitivity, specificity and likelihood ratios
Improved measurement of the lifetime of the τ lepton
A new measurement of the τ lifetime is presented. It uses data collected with the Opal detector during 1994, which almost doubles the size of the Opal τ sample. Two statistically independent techniques are used: an impact parameter analysis of one-prong decay tracks and a fit to the decay length distribution of three-prong decays. The lifetime obtained from the 1994 data by combining the results of these methods is τ(τ) = 289.7 ± 2.5 (stat)± 1.5 (sys) fs. When combined with the previous Opal τ lifetime measurement the improved τ lifetime is τ(τ) = 289.2 ± 1.7 (stat.) ± 1.2 (sys.) fs
Low back pain patients in Sweden, Denmark and the UK share similar characteristics and outcomes: a cross-national comparison of prospective cohort studies
Integrating GWAS and Transcriptomics to Identify the Molecular Underpinnings of Thermal Stress Responses in \u3cem\u3eDrosophila melanogaster\u3c/em\u3e
Thermal tolerance of an organism depends on both the ability to dynamically adjust to a thermal stress and preparatory developmental processes that enhance thermal resistance. However, the extent to which standing genetic variation in thermal tolerance alleles influence dynamic stress responses vs. preparatory processes is unknown. Here, using the model species Drosophila melanogaster, we used a combination of Genome Wide Association mapping (GWAS) and transcriptomic profiling to characterize whether genes associated with thermal tolerance are primarily involved in dynamic stress responses or preparatory processes that influence physiological condition at the time of thermal stress. To test our hypotheses, we measured the critical thermal minimum (CTmin) and critical thermal maximum (CTmax) of 100 lines of the Drosophila Genetic Reference Panel (DGRP) and used GWAS to identify loci that explain variation in thermal limits. We observed greater variation in lower thermal limits, with CTmin ranging from 1.81 to 8.60°C, while CTmax ranged from 38.74 to 40.64°C. We identified 151 and 99 distinct genes associated with CTmin and CTmax, respectively, and there was strong support that these genes are involved in both dynamic responses to thermal stress and preparatory processes that increase thermal resistance. Many of the genes identified by GWAS were involved in the direct transcriptional response to thermal stress (72/151 for cold; 59/99 for heat), and overall GWAS candidates were more likely to be differentially expressed than other genes. Further, several GWAS candidates were regulatory genes that may participate in the regulation of stress responses, and gene ontologies related to development and morphogenesis were enriched, suggesting many of these genes influence thermal tolerance through effects on development and physiological status. Overall, our results suggest that thermal tolerance alleles can influence both dynamic plastic responses to thermal stress and preparatory processes that improve thermal resistance. These results also have utility for directly comparing GWAS and transcriptomic approaches for identifying candidate genes associated with thermal tolerance
GEANT4 : a simulation toolkit
Abstract Geant4 is a toolkit for simulating the passage of particles through matter. It includes a complete range of functionality including tracking, geometry, physics models and hits. The physics processes offered cover a comprehensive range, including electromagnetic, hadronic and optical processes, a large set of long-lived particles, materials and elements, over a wide energy range starting, in some cases, from 250 eV and extending in others to the TeV energy range. It has been designed and constructed to expose the physics models utilised, to handle complex geometries, and to enable its easy adaptation for optimal use in different sets of applications. The toolkit is the result of a worldwide collaboration of physicists and software engineers. It has been created exploiting software engineering and object-oriented technology and implemented in the C++ programming language. It has been used in applications in particle physics, nuclear physics, accelerator design, space engineering and medical physics. PACS: 07.05.Tp; 13; 2
Chiropractic student choices in relation to indications, non-indications and contra-indications of continued care
Scaling violations of quark and gluon jet fragmentation functions in e+e- annihilations at sqrt(s) = 91.2 and 183-209 GeV
Flavour inclusive, udsc and b fragmentation functions in unbiased jets, and
flavour inclusive, udsc, b and gluon fragmentation functions in biased jets are
measured in e+e- annihilations from data collected at centre-of-mass energies
of 91.2, and 183-209 GeV with the OPAL detector at LEP. The unbiased jets are
defined by hemispheres of inclusive hadronic events, while the biased jet
measurements are based on three-jet events selected with jet algorithms.
Several methods are employed to extract the fragmentation functions over a wide
range of scales. Possible biases are studied in the results are obtained. The
fragmentation functions are compared to results from lower energy e+e-
experiments and with earlier LEP measurements and are found to be consistent.
Scaling violations are observed and are found to be stronger for the
fragmentation functions of gluon jets than for those of quarks. The measured
fragmentation functions are compared to three recent theoretical
next-to-leading order calculations and to the predictions of three Monte Carlo
event generators. While the Monte Carlo models are in good agreement with the
data, the theoretical predictions fail to describe the full set of results, in
particular the b and gluon jet measurements.Comment: 46 pages, 17 figures, Submitted to Eur. Phys J.
Search for Yukawa Production of a Light Neutral Higgs Boson at LEP
Within a Two-Higgs-Doublet Model (2HDM) a search for a light Higgs boson in
the mass range of 4-12 GeV has been performed in the Yukawa process e+e- -> b
bbar A/h -> b bbar tau+tau-, using the data collected by the OPAL detector at
LEP between 1992 and 1995 in e+e- collisions at about 91 GeV centre-of-mass
energy. A likelihood selection is applied to separate background and signal.
The number of observed events is in good agreement with the expected
background. Within a CP-conserving 2HDM type II model the cross-section for
Yukawa production depends on xiAd = |tan beta| and xihd = |sin alpha/cos beta|
for the production of the CP-odd A and the CP-even h, respectively, where tan
beta is the ratio of the vacuum expectation values of the Higgs doublets and
alpha is the mixing angle between the neutral CP-even Higgs bosons. From our
data 95% C.L. upper limits are derived for xiAd within the range of 8.5 to 13.6
and for xihd between 8.2 to 13.7, depending on the mass of the Higgs boson,
assuming a branching fraction into tau+tau- of 100%. An interpretation of the
limits within a 2HDM type II model with Standard Model particle content is
given. These results impose constraints on several models that have been
proposed to explain the recent BNL measurement of the muon anomalous magnetic
moment.Comment: 24 pages, 9 figures, Submitted to Euro. Phys. J.
Tests of model of color reconnection and a search for glueballs using gluon jets with a rapidity gap
Gluon jets with a mean energy of 22 GeV and purity of 95% are selected from
hadronic Z0 decay events produced in e+e- annihilations. A subsample of these
jets is identified which exhibits a large gap in the rapidity distribution of
particles within the jet. After imposing the requirement of a rapidity gap, the
gluon jet purity is 86%. These jets are observed to demonstrate a high degree
of sensitivity to the presence of color reconnection, i.e. higher order QCD
processes affecting the underlying color structure. We use our data to test
three QCD models which include a simulation of color reconnection: one in the
Ariadne Monte Carlo, one in the Herwig Monte Carlo, and the other by Rathsman
in the Pythia Monte Carlo. We find the Rathsman and Ariadne color reconnection
models can describe our gluon jet measurements only if very large values are
used for the cutoff parameters which serve to terminate the parton showers, and
that the description of inclusive Z0 data is significantly degraded in this
case. We conclude that color reconnection as implemented by these two models is
disfavored. The signal from the Herwig color reconnection model is less clear
and we do not obtain a definite conclusion concerning this model. In a separate
study, we follow recent theoretical suggestions and search for glueball-like
objects in the leading part of the gluon jets. No clear evidence is observed
for these objects.Comment: 42 pages, 18 figure
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