190 research outputs found
Confinement from new global defect structures
We investigate confinement from new global defect structures in three spatial
dimensions. The global defects arise in models described by a single real
scalar field, governed by special scalar potentials. They appear as
electrically, magnetically or dyonically charged structures. We show that they
induce confinement, when they are solutions of effective QCD-like field
theories in which the vacua are regarded as color dielectric media with an
anti-screening property. As expected, in three spatial dimensions the
monopole-like global defects generate the Coulomb potential as part of several
confining potentials.Comment: RevTex4, 7 pages, 1 figure. Version to appear in Eur. Phys. J.
Risk, Timing, and Predictors of Disease Flare After Discontinuation of Anti–Tumor Necrosis Factor Therapy in Children With Polyarticular Forms of Juvenile Idiopathic Arthritis With Clinically Inactive Disease
© 2018, American College of Rheumatology Objective: To determine the frequency, time to flare, and predictors of disease flare upon withdrawal of anti–tumor necrosis factor (anti-TNF) therapy in children with polyarticular forms of juvenile idiopathic arthritis (JIA) who demonstrated ≥6 months of continuous clinically inactive disease. Methods: In 16 centers 137 patients with clinically inactive JIA who were receiving anti-TNF therapy (42% of whom were also receiving methotrexate [MTX]) were prospectively followed up. If the disease remained clinically inactive for the initial 6 months of the study, anti-TNF was stopped and patients were assessed for flare at 1, 2, 3, 4, 6, and 8 months. Life-table analysis, t-tests, chi-square test, and Cox regression analysis were used to identify independent variables that could significantly predict flare by 8 months or time to flare. Results: Of 137 patients, 106 (77%) maintained clinically inactive disease while receiving anti-TNF therapy for the initial 6 months and were included in the phase of the study in which anti-TNF therapy was stopped. Stopping anti-TNF resulted in disease flare in 39 (37%) of 106 patients by 8 months. The mean/median ± SEM time to flare was 212/250 ± 9.77 days. Patients with shorter disease duration at enrollment, older age at onset and diagnosis, shorter disease duration prior to experiencing clinically inactive disease, and shorter time from onset of clinically inactive disease to enrollment were found to have significantly lower hazard ratios for likelihood of flare by 8 months (P \u3c 0.05). Conclusion: Over one-third of patients with polyarticular JIA with sustained clinically inactive disease will experience a flare by 8 months after discontinuation of anti-TNF therapy. Several predictors of lower likelihood of flare were identified
Elliptic flow of charged particles in Pb-Pb collisions at 2.76 TeV
We report the first measurement of charged particle elliptic flow in Pb-Pb
collisions at 2.76 TeV with the ALICE detector at the CERN Large Hadron
Collider. The measurement is performed in the central pseudorapidity region
(||<0.8) and transverse momentum range 0.2< < 5.0 GeV/. The
elliptic flow signal v, measured using the 4-particle correlation method,
averaged over transverse momentum and pseudorapidity is 0.087 0.002
(stat) 0.004 (syst) in the 40-50% centrality class. The differential
elliptic flow v reaches a maximum of 0.2 near = 3
GeV/. Compared to RHIC Au-Au collisions at 200 GeV, the elliptic flow
increases by about 30%. Some hydrodynamic model predictions which include
viscous corrections are in agreement with the observed increase.Comment: 10 pages, 4 captioned figures, published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/389
Two-pion Bose-Einstein correlations in central Pb-Pb collisions at = 2.76 TeV
The first measurement of two-pion Bose-Einstein correlations in central Pb-Pb
collisions at TeV at the Large Hadron Collider is
presented. We observe a growing trend with energy now not only for the
longitudinal and the outward but also for the sideward pion source radius. The
pion homogeneity volume and the decoupling time are significantly larger than
those measured at RHIC.Comment: 17 pages, 5 captioned figures, 1 table, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/388
Suppression of charged particle production at large transverse momentum in central Pb-Pb collisions at TeV
Inclusive transverse momentum spectra of primary charged particles in Pb-Pb
collisions at = 2.76 TeV have been measured by the ALICE
Collaboration at the LHC. The data are presented for central and peripheral
collisions, corresponding to 0-5% and 70-80% of the hadronic Pb-Pb cross
section. The measured charged particle spectra in and GeV/ are compared to the expectation in pp collisions at the same
, scaled by the number of underlying nucleon-nucleon
collisions. The comparison is expressed in terms of the nuclear modification
factor . The result indicates only weak medium effects ( 0.7) in peripheral collisions. In central collisions,
reaches a minimum of about 0.14 at -7GeV/ and increases
significantly at larger . The measured suppression of high- particles is stronger than that observed at lower collision energies,
indicating that a very dense medium is formed in central Pb-Pb collisions at
the LHC.Comment: 15 pages, 5 captioned figures, 3 tables, authors from page 10,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/98
Do financial incentives for delivering health promotion counselling work? Analysis of smoking cessation activities stimulated by the quality and outcomes framework
<p>Abstract</p> <p>Background</p> <p>A substantial fraction of UK general practitioners' salaries is now intended to reflect the quality of care provided. This performance-related pay system has probably improved aspects of primary health care but, using the observational data available, disentangling the impacts of different types of targets set within this unique payment system is challenging.</p> <p>Discussion</p> <p>Financial incentives undoubtedly influence GPs' activities, however, those aimed at encouraging GPs' delivery of health promotion counselling may not always have the effects intended. There is strong, observational evidence that targets and incentives intended to increase smoking cessation counselling by GPs have merely increased their propensity to record this activity in patients' medical records. The limitations of using financial incentives to stimulate the delivery of counselling in primary care are discussed and a re-appraisal of their use within UK GPs' performance-related pay system is argued for.</p> <p>Summary</p> <p>The utility of targets employed by the system for UK General Practitioners' performance related pay may be inappropriate for encouraging the delivery of health promotion counselling interventions. An evaluation of these targets is essential before they are further developed or added to.</p
Investments in the Human Capital of the Socially Disadvantaged Children – Effects on Redistribution
The ALICE Transition Radiation Detector: Construction, operation, and performance
The Transition Radiation Detector (TRD) was designed and built to enhance the capabilities of the ALICE detector at the Large Hadron Collider (LHC). While aimed at providing electron identification and triggering, the TRD also contributes significantly to the track reconstruction and calibration in the central barrel of ALICE. In this paper the design, construction, operation, and performance of this detector are discussed. A pion rejection factor of up to 410 is achieved at a momentum of 1 GeV/c in p-Pb collisions and the resolution at high transverse momentum improves by about 40% when including the TRD information in track reconstruction. The triggering capability is demonstrated both for jet, light nuclei, and electron selection. (c) 2017 CERN for the benefit of the Authors. Published by Elsevier B.V
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