1,208 research outputs found

    Quark spectral properties above Tc from Dyson-Schwinger equations

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    We report on an analysis of the quark spectral representation at finite temperatures based on the quark propagator determined from its Dyson-Schwinger equation in Landau gauge. In Euclidean space we achieve nice agreement with recent results from quenched lattice QCD. We find different analytical properties of the quark propagator below and above the deconfinement transition. Using a variety of ansaetze for the spectral function we then analyze the possible quasiparticle spectrum, in particular its quark mass and momentum dependence in the high temperature phase. This analysis is completed by an application of the Maximum Entropy Method, in principle allowing for any positive semi-definite spectral function. Our results motivate a more direct determination of the spectral function in the framework of Dyson-Schwinger equations

    On Gribov's supercriticality picture of quark confinement

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    Some years ago Gribov developed the so-called supercritical light quark confinement scenario. Based on physical arguments he conjectured a drastic change in the analytical properties of the quark propagator when the back-reaction of Goldstone bosons (pions) is considered. We investigate this scenario and provide numerical solutions for the quark propagator in the complex plane with and without the pion back-reaction. We find no evidence for the scenario Gribov advocated. As an aside we present a novel method to solve the quark Dyson-Schwinger equation in the complex plane and discuss new characteristics of dynamical chiral symmetry breaking in our truncation scheme.Comment: 21 pages, 12 figures. Version to appear in EPJ

    Bullying girls - Changes after brief strategic family therapy: A randomized, prospective, controlled trial with one-year follow-up

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    Background: Many girls bully others. They are conspicuous because of their risk-taking behavior, increased anger, problematic interpersonal relationships and poor quality of life. Our aim was to determine the efficacy of brief strategic family therapy (BSFT) for bullying-related behavior, anger reduction, improvement of interpersonal relationships, and improvement of health-related quality of life in girls who bully, and to find out whether their expressive aggression correlates with their distinctive psychological features. Methods: 40 bullying girls were recruited from the general population: 20 were randomly selected for 3 months of BSFT. Follow-up took place 12 months after the therapy had ended. The results of treatment were examined using the Adolescents' Risk-taking Behavior Scale (ARBS), the State-Trait Anger Expression Inventory (STAXI), the Inventory of Interpersonal Problems (IIP-D), and the SF-36 Health Survey (SF-36). Results: In comparison with the control group (CG) (according to the intent-to-treat principle), bullying behavior in the BSFT group was reduced (BSFT-G from n = 20 to n = 6; CG from n = 20 to n = 18, p = 0.05) and statistically significant changes in all risk-taking behaviors (ARBS), on most STAXI, IIP-D, and SF-36 scales were observed after BSFT. The reduction in expressive aggression (Anger-Out scale of the STAXI) correlated with the reduction on several scales of the ARBS, IIP-D, and SF-36. Follow-up a year later showed relatively stable events. Conclusions: Our findings suggest that bullying girls suffer from psychological and social problems which may be reduced by the use of BSFT. Expressive aggression in girls appears to correlate with several types of risk-taking behavior and interpersonal problems, as well as with health-related quality of life. Copyright (c) 2006 S. Karger AG, Basel

    Accuracy of plain radiography in detecting fractures in older individuals after low-energy falls: current evidence

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    BackgroundOlder individuals sustaining low-energy falls (LEF) and presenting to the emergency department (ED) demand straightforward diagnostic measures for injury detection. Plain radiography (XR) series for diagnosis of fall-related injuries are standard of care, but frequently subsequent CT examination is required for diagnostic assurance. A systematic database search of diagnostic accuracy of XR for detection of fractures in older LEF patients was performed.MethodsWe searched PubMed, Embase, Cochrane Library, WHO International Clinical Trial Platform, and Clinical trials.gov databases from inception to January 2020 for studies including older patients (>= 65 years) with LEF and obtaining CT examination and XR of the skeleton in an ED setting.ResultsFrom 8944 references screened, 11 studies met the criteria for inclusion. Performance of XR for detection of fractures of the pelvic ring and hip was analyzed in nine studies, two studies investigated XR performance to detect rib fractures, and two studies compared diagnostic accuracy of thoracolumbar spine XR. Sensitivity estimates ranged from 10% to 58% and specificity estimates from 55% to 100%. Clinical and statistical heterogeneity was significant among included studies, with an overall considerable risk of bias.DiscussionHigh-quality evidence on accurate imaging strategies in older patients with LEF is lacking to date. XR is missing a reasonable amount of fractures of the pelvic ring, rib cage, and thoracic and lumbar spine. However, the utility of first-line CT imaging and the benefit of diagnosing every fracture is unknown, demanding high-quality prospective trials considering patient-oriented outcome as well

    Hadronic unquenching effects in the quark propagator

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    We investigate hadronic unquenching effects in light quarks and mesons. Within the non-perturbative continuum framework of Schwinger-Dyson and Bethe-Salpeter equations we quantify the strength of the back reaction of the pion onto the quark-gluon interaction. To this end we add a Yang-Mills part of the interaction such that unquenched lattice results for various current quark masses are reproduced. We find considerable effects in the quark mass function at low momenta as well as for the chiral condensate. The quark wave function is less affected. The Gell--Mann-Oakes-Renner relation is valid to good accuracy up to pion masses of 400-500 MeV. As a byproduct of our investigation we verify the Coleman theorem, that chiral symmetry cannot be broken spontaneously when QCD is reduced to 1+1 dimensions.Comment: 27 pages, 15 figures, minor corrections and clarifications; version to appear in PR

    What Is Special About Human Rights?

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    Participation as a Core Principle of Community Health Promotion: General Account and Examples

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    One of the key principles of the Ottawa Charta is participation. Community health interventions should involve the community, i.e., residents and local actors. In Hamburg, we tried to put this principle into practice during a project initiated by the municipal health service in a disadvantaged quarter with about 3000 inhabitants. The contribution starts with an account of the meaning of participation in health promotion (1) and gives an overview of participation methods in general (2). The next part contains a short account of our project (3). Five examples are presented in part four: a survey with key actors and two approaches to listening to residents’ perceptions of capacity building in the neighborhood. Another survey of residents was meant to explore the use of health promotion offers and the preparedness to get involved. The last example is the round table of local actors as a sort of steering committee for health promotion interventions (4). Key findings of the examples are: Surveys do result in valuable information for the local actors. The expressed willingness to participate is larger than the actual participation. Opportunities to participate (in surveys and at the round table) are welcome by local actors. In the last section we discuss the advantages, problems and some illusions concerning participation in health promotion (5)

    Pregnant women with bronchial asthma benefit from progressive muscle relaxation: A randomized, prospective, controlled trial

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    Background: Asthma is a serious medical problem in pregnancy and is often associated with stress, anger and poor quality of life. The aim of this study was to determine the efficacy of progressive muscle relaxation (PMR) on change in blood pressure, lung parameters, heart rate, anger and health-related quality of life in pregnant women with bronchial asthma. Methods: We treated a sample of 64 pregnant women with bronchial asthma from the local population in an 8-week randomized, prospective, controlled trial. Thirty-two were selected for PMR, and 32 received a placebo intervention. The systolic blood pressure, forced expiratory volume in the first second, peak expiratory flow and heart rate were tested, and the State-Trait Anger Expression Inventory and Health Survey (SF-36) were employed. Results: According to the intend-to-treat principle, a significant reduction in systolic blood pressure and a significant increase in both forced expiratory volume in the first second and peak expiratory flow were observed after PMR. The heart rate showed a significant increase in the coefficient of variation, root mean square of successive differences and high frequency ranges, in addition to a significant reduction in low and middle frequency ranges. A significant reduction on three of five State-Trait Anger Expression Inventory scales, and a significant increase on seven of eight SF-36 scales were observed. Conclusions: PMR appears to be an effective method to improve blood pressure, lung parameters and heart rate, and to decrease anger levels, thus enhancing health-related quality of life in pregnant women with bronchial asthma. Copyright (c) 2006 S. Karger AG, Basel

    Diagnoses and mortality among prehospital emergency patients calling 112 with unclear problems:a population-based cohort study from Denmark

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    BACKGROUND: Patients calling for an emergency ambulance and assessed as presenting with ‘unclear problem’ account for a considerable part of all emergency calls. Previous studies have demonstrated that these patients are at increased risk for unfavourable outcomes. A deeper insight into the underlying diagnoses and outcomes is essential to improve prehospital treatment. We aimed to investigate which of these diagnoses contributed most to the total burden of diseases in terms of numbers of deaths together with 1- and 30-day mortality. METHODS: A historic regional population-based observational cohort study from the years 2016 to 2018. Diagnoses were classified according to the World Health Organisation ICD-10 System (International Statistical Classification of Diseases and Related Health Problems, 10th edition). The ICD-10 chapters, R (‘symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified)’ and Z (‘factors influencing health status and contact with health services”) were combined and designated “non-specific diagnoses”. Poisson regression with robust variance estimation was used to estimate proportions of mortality in percentages with 95% confidence intervals, crude and adjusted for age, sex and comorbidities. RESULTS: Diagnoses were widespread among the ICD-10 chapters, and the most were ‘non-specific diagnoses’ (40.4%), ‘circulatory diseases’ (9.6%), ‘injuries and poisonings’ (9.4%) and ‘respiratory diseases’ (6.9%). The diagnoses contributing most to the total burden of deaths (n = 554) within 30 days were ‘circulatory diseases’ (n = 148, 26%) followed by ‘non-specific diagnoses’ (n = 88, 16%) ‘respiratory diseases’ (n = 85, 15%), ‘infections’ (n = 54, 10%) and ‘digestive disease’ (n = 39, 7%). Overall mortality was 2.3% (1-day) and 7.1% (30-days). The risk of mortality was highly associated with age. CONCLUSION: This study found that almost half of the patients brought to the hospital after calling 112 with an ‘unclear problem’ were discharged with a ‘non-specific diagnosis’ which might seem trivial but should be explored more as these contributed the second-highest to the total number of deaths after 30 days only exceeded by ‘circulatory diseases’. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13049-022-01052-y
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