69 research outputs found
Frustrated magnets in three dimensions: a nonperturbative approach
Frustrated magnets exhibit unusual critical behaviors: they display scaling
laws accompanied by nonuniversal critical exponents. This suggests that these
systems generically undergo very weak first order phase transitions. Moreover,
the different perturbative approaches used to investigate them are in conflict
and fail to correctly reproduce their behavior. Using a nonperturbative
approach we explain the mismatch between the different perturbative approaches
and account for the nonuniversal scaling observed.Comment: 7 pages, 1 figure. IOP style files included. To appear in Journal of
Physics: Condensed Matter. Proceedings of the conference HFM 2003, Grenoble,
Franc
A non perturbative approach of the principal chiral model between two and four dimensions
We investigate the principal chiral model between two and four dimensions by
means of a non perturbative Wilson-like renormalization group equation. We are
thus able to follow the evolution of the effective coupling constants within
this whole range of dimensions without having recourse to any kind of small
parameter expansion. This allows us to identify its three dimensional critical
physics and to solve the long-standing discrepancy between the different
perturbative approaches that characterizes the class of models to which the
principal chiral model belongs.Comment: 5 pages, 1 figure, Revte
Involvement of patients or their representatives in quality management functions in EU hospitals:implementation and impact on patient-centred care strategies
OBJECTIVE: The objective of this study was to describe the involvement of patients or their representatives in quality management (QM) functions and to assess associations between levels of involvement and the implementation of patient-centred care strategies. DESIGN: A cross-sectional, multilevel STUDY DESIGN: that surveyed quality managers and department heads and data from an organizational audit. SETTING: Randomly selected hospitals (n = 74) from seven European countries (The Czech Republic, France, Germany, Poland, Portugal, Spain and Turkey). PARTICIPANTS: Hospital quality managers (n = 74) and heads of clinical departments (n = 262) in charge of four patient pathways (acute myocardial infarction, stroke, hip fracture and deliveries) participated in the data collection between May 2011 and February 2012. MAIN OUTCOME MEASURES: Four items reflecting essential patient-centred care strategies based on an on-site hospital visit: (1) formal survey seeking views of patients and carers, (2) written policies on patients' rights, (3) patient information literature including guidelines and (4) fact sheets for post-discharge care. The main predictors were patient involvement in QM at the (i) hospital level and (ii) pathway level. RESULTS: Current levels of involving patients and their representatives in QM functions in European hospitals are low at hospital level (mean score 1.6 on a scale of 0 to 5, SD 0.7), but even lower at departmental level (mean 0.6, SD 0.7). We did not detect associations between levels of involving patients and their representatives in QM functions and the implementation of patient-centred care strategies; however, the smallest hospitals were more likely to have implemented patient-centred care strategies. CONCLUSIONS: There is insufficient evidence that involving patients and their representatives in QM leads to establishing or implementing strategies and procedures that facilitate patient-centred care; however, lack of evidence should not be interpreted as evidence of no effect
Nonperturbative renormalization group approach to frustrated magnets
This article is devoted to the study of the critical properties of classical
XY and Heisenberg frustrated magnets in three dimensions. We first analyze the
experimental and numerical situations. We show that the unusual behaviors
encountered in these systems, typically nonuniversal scaling, are hardly
compatible with the hypothesis of a second order phase transition. We then
review the various perturbative and early nonperturbative approaches used to
investigate these systems. We argue that none of them provides a completely
satisfactory description of the three-dimensional critical behavior. We then
recall the principles of the nonperturbative approach - the effective average
action method - that we have used to investigate the physics of frustrated
magnets. First, we recall the treatment of the unfrustrated - O(N) - case with
this method. This allows to introduce its technical aspects. Then, we show how
this method unables to clarify most of the problems encountered in the previous
theoretical descriptions of frustrated magnets. Firstly, we get an explanation
of the long-standing mismatch between different perturbative approaches which
consists in a nonperturbative mechanism of annihilation of fixed points between
two and three dimensions. Secondly, we get a coherent picture of the physics of
frustrated magnets in qualitative and (semi-) quantitative agreement with the
numerical and experimental results. The central feature that emerges from our
approach is the existence of scaling behaviors without fixed or pseudo-fixed
point and that relies on a slowing-down of the renormalization group flow in a
whole region in the coupling constants space. This phenomenon allows to explain
the occurence of generic weak first order behaviors and to understand the
absence of universality in the critical behavior of frustrated magnets.Comment: 58 pages, 15 PS figure
Is having quality as an item on the executive board agenda associated with the implementation of quality management systems in European hospitals: a quantitative analysis.
OBJECTIVE: To assess whether there is a relationship between having quality as an item on the board's agenda, perceived external pressure (PEP) and the implementation of quality management in European hospitals. DESIGN: A quantitative, mixed method, cross-sectional study in seven European countries in 2011 surveying CEOs and quality managers and data from onsite audits. PARTICIPANTS: One hundred and fifty-five CEOs and 155 quality managers. SETTING: One hundred and fifty-five randomly selected acute care hospitals in seven European countries (Czech Republic, France, Germany, Poland, Portugal, Spain and Turkey). Main outcome measure(s) Three constructs reflecting quality management based on questionnaire and audit data: (i) Quality Management System Index, (ii) Quality Management Compliance Index and (iii) Clinical Quality Implementation Index. The main predictor was whether quality performance was on the executive board's agenda. RESULTS: Discussing quality performance at executive board meetings more often was associated with a higher quality management system score (regression coefficient b = 2.53; SE = 1.16; P = 0.030). We found a trend in the associations of discussing quality performance with quality compliance and clinical quality implementation. PEP did not modify these relationships. CONCLUSIONS: Having quality as an item on the executive board's agenda allows them to review and discuss quality performance more often in order to improve their hospital's quality management. Generally, and as this study found, having quality on the executive board's agenda matters
Development and validation of an index to assess hospital quality management systems
The study, "Deepening our Understanding of Quality Improvement in Europe (DUQuE)" has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 241822. Funding to pay the Open Access publication charges for this article was provided by European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 241822.Objective: The aim of this study was to develop and validate an index to assess the implementation of quality management systems (QMSs) in European countries. Design: Questionnaire development was facilitated through expert opinion, literature review and earlier empirical research. A cross-sectional online survey utilizing the questionnaire was undertaken between May 2011 and February 2012. We used psychometric methods to explore the factor structure, reliability and validity of the instrument. Setting and participants. As part of the Deepening our Understanding of Quality improvement in Europe (DUQuE) project, we invited a random sample of 188 hospitals in 7 countries. The quality managers of these hospitals were the main respondents. Main Outcome Measure. The extent of implementation of QMSs. Results: Factor analysis yielded nine scales, which were combined to build the Quality Management Systems Index. Cronbach's reliability coefficients were satisfactory (ranging from 0.72 to 0.82) for eight scales and low for one scale (0.48). Corrected item-total correlations provided adequate evidence of factor homogeneity. Inter-scale correlations showed that every factor was related, but also distinct, and added to the index. Construct validity testing showed that the index was related to recent measures of quality. Participating hospitals attained a mean value of 19.7 (standard deviation of 4.7) on the index that theoretically ranged from 0 to 27. Conclusion: Assessing QMSs across Europe has the potential to help policy-makers and other stakeholders to compare hospitals and focus on the most important areas for improvement
Involvement of patients or their representatives in quality management functions in EU hospitals : Implementation and impact on patient-centred care strategies
The study, "Deepening our Understanding of Quality Improvement in Europe (DUQuE)" has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 241822. Funding to pay the Open Access publication charges for this article was provided by European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no 241822.Objective: The objective of this study was to describe the involvement of patients or their representatives in quality management (QM) functions and to assess associations between levels of involvement and the implementation of patient-centred care strategies. Design: A cross-sectional, multilevel study design that surveyed quality managers and department heads and data from an organizational audit. Setting: Randomly selected hospitals (n = 74) from seven European countries (The Czech Republic, France, Germany, Poland, Portugal, Spain and Turkey). Participants: Hospital qualitymanagers (n = 74) and heads of clinical departments (n = 262) in charge of four patient pathways (acute myocardial infarction, stroke, hip fracture and deliveries) participated in the data collection between May 2011 and February 2012. Main Outcome Measures: Four items reflecting essential patient-centred care strategies based on an on-site hospital visit: (1) formal survey seeking views of patients and carers, (2) written policies on patients' rights, (3) patient information literature including guidelines and (4) fact sheets for post-discharge care. The main predictors were patient involvement in QM at the (i) hospital level and (ii) pathway level. Results: Current levels of involving patients and their representatives in QM functions in European hospitals are low at hospital level (mean score 1.6 on a scale of 0 to 5, SD 0.7), but even lower at departmental level (mean 0.6, SD 0.7). We did not detect associations between levels of involving patients and their representatives in QM functions and the implementation of patient-centred care strategies; however, the smallest hospitals were more likely to have implemented patient-centred care strategies. Conclusions: There is insufficient evidence that involving patients and their representatives in QM leads to establishing or implementing strategies and procedures that facilitate patient-centred care; however, lack of evidence should not be interpreted as evidence of no effect
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