The Role of Center Vortices in QCD

Center vortices are unambiguously identified after Laplacian Center Gauge fixing and their influence on confinement and chiral symmetry breaking is investigated on a sample of SU(2) configurations at zero and finite temperature.Comment: LaTeX, 4 pages, 3 figures, espcrc1.sty. Talk at PANIC '99, Uppsala, Sweden, June 9

Carbonation of concrete with construction and demolition waste based recycled aggregates and cement with recycled content

Durability is a major concern in concrete (particularly recycled concrete) structures exposed to carbonation-induced corrosion, given the social, economic, environmental and safety implications involved. This article explores carbonation performance in concrete with 25% or 50% mixed recycled construction and demolition waste aggregate, alone or in conjunction with cement containing 25% fired clay construction and demolition waste. Irrespective of cement type, the mean carbonation depth was slightly greater in materials with 25% or 50% recycled aggregate than in concretes with 100% natural aggregate, although the difference was not statistically significant for the 25% replacement ratio. In all the concretes studied, the carbonation coefficient was below the 4 mm/yr0.5 indicative of good quality. Based on the prediction model proposed in Spain’s concrete code, reinforcement passivity was guaranteed in all these types of concrete when exposed to class XC1 to XC4 carbonation environments for substantially longer than their 100 year design service life.This study was funded under research projects BIA 2013-48876-C3-1-R, BIA2013-48876-C3-2-R and BIA2016-76643-C3-1-R awarded by the Ministry of Science and Innovation and grant GR 18122 awarded to the MATERIA Research Group by the Regional Government of Extremadura and the European Regional Development Fund, ERDF. In 2016 University of Extremadura teaching and research personnel benefitted from a mobility grant (MOV15A029) awarded by the Regional Government of Extremadura and in 2018 from a José Castillejo (CAS17/00313) scholarship granted by the Spanish Ministry of Education, Culture and Sport. Philip Van den Heede is since October 2017 a postdoctoral fellow of the Research Foundation—Flanders (FWO) (project number 3E013917) and acknowledges its support.Peer reviewe

High Order Upwind Schemes for Multidimensional Magnetohydrodynamics

A general method for constructing high order upwind schemes for multidimensional magnetohydrodynamics (MHD), having as a main built-in condition the divergence-free constraint \divb=0 for the magnetic field vector \bb, is proposed. The suggested procedure is based on {\em consistency} arguments, by taking into account the specific operator structure of MHD equations with respect to the reference Euler equations of gas-dynamics. This approach leads in a natural way to a staggered representation of the \bb field numerical data where the divergence-free condition in the cell-averaged form, corresponding to second order accurate numerical derivatives, is exactly fulfilled. To extend this property to higher order schemes, we then give general prescriptions to satisfy a $(r+1)^{th}$ order accurate \divb=0 relation for any numerical \bb field having a $r^{th}$ order interpolation accuracy. Consistency arguments lead also to a proper formulation of the upwind procedures needed to integrate the induction equations, assuring the exact conservation in time of the divergence-free condition and the related continuity properties for the \bb vector components. As an application, a third order code to simulate multidimensional MHD flows of astrophysical interest is developed using ENO-based reconstruction algorithms. Several test problems to illustrate and validate the proposed approach are finally presented.Comment: 34 pages, including 14 figure

Clinician-targeted interventions to reduce antibiotic prescribing for acute respiratory infections in primary care:An overview of systematic reviews

This is the protocol for a review and there is no abstract. The objectives are as follows: To systematically review the literature and appraise the existing evidence from systematic reviews regarding the effects of interventions, aimed at changing clinician behaviour, to reduce antibiotic prescribing for ARIs in primary care

Incorporating Uncertainties in Atomic Data Into the Analysis of Solar and Stellar Observations: A Case Study in Fe XIII

Information about the physical properties of astrophysical objects cannot be measured directly but is inferred by interpreting spectroscopic observations in the context of atomic physics calculations. Ratios of emission lines, for example, can be used to infer the electron density of the emitting plasma. Similarly, the relative intensities of emission lines formed over a wide range of temperatures yield information on the temperature structure. A critical component of this analysis is understanding how uncertainties in the underlying atomic physics propagates to the uncertainties in the inferred plasma parameters. At present, however, atomic physics databases do not include uncertainties on the atomic parameters and there is no established methodology for using them even if they did. In this paper we develop simple models for the uncertainties in the collision strengths and decay rates for Fe XIII and apply them to the interpretation of density sensitive lines observed with the EUV Imagining spectrometer (EIS) on Hinode. We incorporate these uncertainties in a Bayesian framework. We consider both a pragmatic Bayesian method where the atomic physics information is unaffected by the observed data, and a fully Bayesian method where the data can be used to probe the physics. The former generally increases the uncertainty in the inferred density by about a factor of 5 compared with models that incorporate only statistical uncertainties. The latter reduces the uncertainties on the inferred densities, but identifies areas of possible systematic problems with either the atomic physics or the observed intensities.Comment: in press at Ap

Clinician-targeted interventions to influence antibiotic prescribing behaviour for acute respiratory infections in primary care: An overview of systematic reviews

Background: Antibiotic resistance is a worldwide health threat. Interventions that reduce antibiotic prescribing by clinicians are expected to reduce antibiotic resistance. Disparate interventions to change antibiotic prescribing behaviour for acute respiratory infections (ARIs) have been trialled and meta-analysed, but not yet synthesised in an overview. This overview synthesises evidence from systematic reviews, rather than individual trials. Objectives: To systematically review the existing evidence from systematic reviews on the effects of interventions aimed at influencing clinician antibiotic prescribing behaviour for ARIs in primary care. Methods: We searched the Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects (DARE), MEDLINE, Embase, CINAHL, PsycINFO, and Science Citation Index to June 2016. We also searched the reference lists of all included reviews. We ran a pre-publication search in May 2017 and placed additional studies in 'awaiting classification'. We included both Cochrane and non-Cochrane reviews of randomised controlled trials evaluating the effect of any clinician-focussed intervention on antibiotic prescribing behaviour in primary care. Two overview authors independently extracted data and assessed the methodological quality of included reviews using the ROBIS tool, with disagreements reached by consensus or by discussion with a third overview author. We used the GRADE system to assess the quality of evidence in included reviews. The results are presented as a narrative overview. Main results: We included eight reviews in this overview: five Cochrane Reviews (33 included trials) and three non-Cochrane reviews (11 included trials). Three reviews (all Cochrane Reviews) scored low risk across all the ROBIS domains in Phase 2 and low risk of bias overall. The remaining five reviews scored high risk on Domain 4 of Phase 2 because the 'Risk of bias' assessment had not been specifically considered and discussed in the review Results and Conclusions. The trials included in the reviews varied in both size and risk of bias. Interventions were compared to usual care. Moderate-quality evidence indicated that C-reactive protein (CRP) point-of-care testing (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.66 to 0.92, 3284 participants, 6 trials), shared decision making (odds ratio (OR) 0.44, 95% CI 0.26 to 0.75, 3274 participants, 3 trials; RR 0.64, 95% CI 0.49 to 0.84, 4623 participants, 2 trials; risk difference -18.44, 95% CI -27.24 to -9.65, 481,807 participants, 4 trials), and procalcitonin-guided management (adjusted OR 0.10, 95% CI 0.07 to 0.14, 1008 participants, 2 trials) probably reduce antibiotic prescribing in general practice. We found moderate-quality evidence that procalcitonin-guided management probably reduces antibiotic prescribing in emergency departments (adjusted OR 0.34, 95% CI 0.28 to 0.43, 2605 participants, 7 trials). The overall effect of these interventions was small (few achieving greater than 50% reduction in antibiotic prescribing, most about a quarter or less), but likely to be clinically important. Compared to usual care, shared decision making probably makes little or no difference to reconsultation for the same illness (RR 0.87, 95% CI 0.74 to 1.03, 1860 participants, 4 trials, moderate-quality evidence), and may make little or no difference to patient satisfaction (RR 0.86, 95% CI 0.57 to 1.30, 1110 participants, 2 trials, low-quality evidence). Similarly, CRP testing probably has little or no effect on patient satisfaction (RR 0.79, 95% CI 0.57 to 1.08, 689 participants, 2 trials, moderate-quality evidence) or reconsultation (RR 1.08, 95% CI 0.93 to 1.27, 5132 participants, 4 trials, moderate-quality evidence). Procalcitonin-guided management probably results in little or no difference in treatment failure in general practice compared to normal care (adjusted OR 0.95, 95% CI 0.73 to 1.24, 1008 participants, 2 trials, moderate-quality evidence), however it probably reduces treatment failure in the emergency department compared to usual care (adjusted OR 0.76, 95% CI 0.61 to 0.95, 2605 participants, 7 trials, moderate-quality evidence). The quality of evidence for interventions focused on clinician educational materials and decision support in reducing antibiotic prescribing in general practice was either low or very low (no pooled result reported) and trial results were highly heterogeneous, therefore we were unable draw conclusions about the effects of these interventions. The use of rapid viral diagnostics in emergency departments may have little or no effect on antibiotic prescribing (RR 0.86, 95% CI 0.61 to 1.22, 891 participants, 3 trials, low-quality evidence) and may result in little to no difference in reconsultation (RR 0.86, 95% CI 0.59 to 1.25, 200 participants, 1 trial, low-quality evidence). None of the trials in the included reviews reported on management costs for the treatment of an ARI or any associated complications. Authors' conclusions: We found evidence that CRP testing, shared decision making, and procalcitonin-guided management reduce antibiotic prescribing for patients with ARIs in primary care. These interventions may therefore reduce overall antibiotic consumption and consequently antibiotic resistance. There do not appear to be negative effects of these interventions on the outcomes of patient satisfaction and reconsultation, although there was limited measurement of these outcomes in the trials. This should be rectified in future trials. We could gather no information about the costs of management, and this along with the paucity of measurements meant that it was difficult to weigh the benefits and costs of implementing these interventions in practice. Most of this research was undertaken in high-income countries, and it may not generalise to other settings. The quality of evidence for the interventions of educational materials and tools for patients and clinicians was either low or very low, which prevented us from drawing any conclusions. High-quality trials are needed to further investigate these interventions. </p

Status of center dominance in various center gauges

We review arguments for center dominance in center gauges where vortex locations are correctly identified. We introduce an appealing interpretation of the maximal center gauge, discuss problems with Gribov copies, and a cure to the problems through the direct Laplacian center gauge. We study correlations between direct and indirect Laplacian center gauges.Comment: Presented by S. Olejnik at the NATO Advanced Research Workshop "Confinement, Topology, and other Non-Perturbative Aspects of QCD", Jan. 21-27, 2002, Stara Lesna, Slovakia. 10 pages, 3 figures (8 EPS files), uses crckapb.st

Secondary infall model and dark matter scaling relations in intermediate redshift early - type galaxies

Scaling relations among dark matter (DM) and stellar quantities are a valuable tool to constrain formation scenarios and the evolution of galactic structures. However, most of the DM properties are actually not directly measured, but derived through model dependent mass mapping procedures. It is therefore crucial to adopt theoretically and observationally well founded models. We use here an updated version of the secondary infall model (SIM) to predict the halo density profile, taking into account the effects of angular momentum, dissipative friction and baryons collapse. The resulting family of halo profiles depends on one parameter only, the virial mass, and nicely fits the projected mass and aperture velocity dispersion of a sample of intermediate redshift lens galaxies. We derive DM related quantities (namely the column density and the Newtonian acceleration) and investigate their correlations with stellar mass, luminosity, effective radius and virial mass.Comment: 15 pages, 3 figures, 2 tables, accepted for publication on MNRA

Theory of Abelian Projection

Analytic methods for Abelian projection are developed. A number of results are obtained related to string tension measurements. It is proven that even without gauge fixing, abelian projection yields string tensions of the underlying non-Abelian theory. Strong arguments are given for similar results in the case where gauge fixing is employed. The methods used emphasize that the projected theory is derived from the underlying non-Abelian theory rather than vice versa. In general, the choice of subgroup used for projection is not very important, and need not be Abelian. While gauge fixing is shown to be in principle unnecessary for the success of Abelian projection, it is computationally advantageous for the same reasons that improved operators, e.g., the use of fat links, are advantageous in Wilson loop measurements. Two other issues, Casimir scaling and the conflict between projection and critical universality, are also discussed.Comment: Minor corrections, new section added, 14 pages, 3 figures, RevTe

Acute and long-lasting effects of oxytocin in cortico-limbic circuits: consequences for fear recall and extinction.

The extinction of conditioned fear responses entrains the formation of safe new memories to decrease those behavioral responses. The knowledge in neuronal mechanisms of extinction is fundamental in the treatment of anxiety and fear disorders. Interestingly, the use of pharmacological compounds that reduce anxiety and fear has been shown as a potent co-adjuvant in extinction therapy. However, the efficiency and mechanisms by which pharmacological compounds promote extinction of fear memories remains still largely unknown and would benefit from a validation based on functional neuronal circuits, and the neurotransmitters that modulate them. From this perspective, oxytocin receptor signaling, which has been shown in cortical and limbic areas to modulate numerous functions (Eliava et al. Neuron 89(6):1291-1304, 2016), among them fear and anxiety circuits, and to enhance the salience of social stimuli (Stoop Neuron 76(1):142-59, 2012), may offer an interesting perspective. Experiments in animals and humans suggest that oxytocin could be a promising pharmacological agent at adjusting memory consolidation to boost fear extinction. Additionally, it is possible that long-term changes in endogenous oxytocin signaling can also play a role in reducing expression of fear at different brain targets. In this review, we summarize the effects reported for oxytocin in cortico-limbic circuits and on fear behavior that are of relevance for the modulation and potential extinction of fear memories