Ensemble averages and nonextensivity at the edge of chaos of one-dimensional maps

Ensemble averages of the sensitivity to initial conditions $\xi(t)$ and the entropy production per unit time of a {\it new} family of one-dimensional dissipative maps, $x_{t+1}=1-ae^{-1/|x_t|^z}(z>0)$, and of the known logistic-like maps, $x_{t+1}=1-a|x_t|^z(z>1)$, are numerically studied, both for {\it strong} (Lyapunov exponent $\lambda_1>0$) and {\it weak} (chaos threshold, i.e., $\lambda_1=0$) chaotic cases. In all cases we verify that (i) both $[\ln_q x \equiv (x^{1-q}-1)/(1-q); \ln_1 x=\ln x]$ and $<S_q > [S_q \equiv (1-\sum_i p_i^q)/(q-1); S_1=-\sum_i p_i \ln p_i]$ {\it linearly} increase with time for (and only for) a special value of $q$, $q_{sen}^{av}$, and (ii) the {\it slope} of $$and that of$$ {\it coincide}, thus interestingly extending the well known Pesin theorem. For strong chaos, $q_{sen}^{av}=1$, whereas at the edge of chaos, $q_{sen}^{av}(z)<1$.Comment: 5 pages, 5 figure

Evaluation de l'efficacité d'une tarification optionnelle de l'eau d'irrigation en Charente

En période d'étiage, certains bassins versants connaissent un déséquilibre entre la ressource en eau disponible et les usages. En France, le développement de l'irrigation depuis les années 1970 a constitué un facteur important de ce déséquilibre. Les besoins peuvent dépasser l'offre en eau du milieu naturel. Favorisée par la loi sur l'eau de 1992 qui oblige le comptage de l'eau agricole et recommande la concertation, une gestion volumétrique s'est progressivement développée. Ce mode de gestion consiste à répartir équitablement une offre en eau en définissant, selon son état, des règles d'accès entre les différents usages. La gestion volumétrique existe déjà sur des systèmes où l'offre en eau est prévisible avec une bonne probabilité (nappe ou barrage). Le bassin de la Charente amont a la particularité de présenter un déséquilibre important auquel s'ajoute une offre en eau très sensible aux aléas climatiques comme les orages. La gestion volumétrique y est cependant pratiquée depuis la construction du barrage de Mas-Chaban, qui permet de soutenir l'étiage. Cet article présente les instruments de gestion volumétrique mis en ½uvre sur ce bassin, discute leur efficacité et propose un nouveau système de gestion basé sur une tarification optionnelle de l'eau et sur un système nouveau de comptage et de déclaration des consommations. Nous montrons alors que ce système peut permettre non seulement d'économiser la ressource mais également de réduire les iniquités au sein même de la profession agricole / In period of low water level, some river basins face an imbalance between the available water resource and the uses. In France, the development of the irrigation since the years 1970 is an important cause of this imbalance. The water needs can exceed the natural water supply. Favoured by the 1992 French water act, rending the metering progressively obligatory and that recommend dialogue among water actors, a volumetric management (VM) mechanism has progressively been implemented. A VM consists in finding a equitable distribution of the water in defining, according to its state, some access rules among users. VM already exists in systems where the water supply is foreseeable with a good probability (tablecloth or dam). The Upstream Charente river basin in France face an important imbalance added to high sensitivity of the resource to the climatic conditions. However, a VM is implemented in this basin since the creation of Mas-Chaban dam in year 2000, which allow to resupply the river. This article presents the VM instruments implemented in this basin, discusses their effectiveness and propose an alternative management system based on an optional water pricing and on a new water consumption declaration system improving control and allowing potential sanctions. It is then shown that this system can save water an in the same time reduce inequities among farmersIRRIGATION;ECONOMIE DE L'EAU;ANALYSE COUT BENEFICE;PRIX;EVALUATION ECONOMIQUE;FRANCE;CHARENTE

Trajectories of self-rated health in people with diabetes: Associations with functioning in a prospective community sample

© 2013 Schmitz et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Self-rated health (SRH) is a single-item measure that is one of the most widely used measures of general health in population health research. Relatively little is known about changes and the trajectories of SRH in people with chronic medical conditions. The aims of the present study were to identify and describe longitudinal trajectories of self-rated health (SRH) status in people with diabetes. Methods: A prospective community study was carried out between 2008 and 2011. SRH was assessed at baseline and yearly at follow-ups (n=1288). Analysis was carried out through trajectory modeling. The trajectory groups were subsequently compared at 4 years follow-up with respect to functioning. Results: Four distinct trajectories of SRH were identified: 1) 72.2% of the participants were assigned to a persistently good SRH trajectory; 2) 10.1% were assigned to a persistently poor SRH trajectory; 3) mean SRH scores changed from good to poor for one group (7.3%); while 4) mean SRH scores changed from poor to medium/good for another group (10.4%). Those with a persistently poor perception of health status were at higher risk for poor functioning at 4 years follow-up than those whose SRH scores decreased from good to poor. Conclusions: SRH is an important predictor for poor functioning in diabetes, but the trajectory of SRH seems to be even more important. Health professionals should pay attention to not only SRH per se, but also changes in SRH over time.This work was supported by Operating Grant MOP-84574 from the Canadian Institutes of Health Research (CIHR). GG was supported by a doctoral fellowship from the CIHR. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Predictors and Implications of Early Clinical Stability in Patients Hospitalized for Moderately Severe Community-Acquired Pneumonia.

Assessment of early response to treatment is crucial for the management of community-acquired pneumonia (CAP). To describe the predictors and the outcomes of early clinical stability. We did a secondary analysis of a multicentre randomized controlled trial on CAP treatment in which 580 patients hospitalized for moderately severe CAP were included. The association between demographic, clinical and biological variables available at inclusion and early clinical stability (stabilization of vital signs within 72 hours with predetermined cut-offs) was assessed by multivariate logistic regression. The association between early clinical stability and mortality, severe adverse events, and length of stay was also tested. Younger age (OR 0.98, 95% CI 0.96-0.99), lower platelet count (OR per 10 G/L increment 0.96, 95% CI 0.94-0.98), lower respiratory rate (OR 0.94, 95% CI 0.90-0.97), absence of hypoxemia (OR 0.58, 95% CI 0.40-0.85), lower numbers of co-morbid conditions (OR 0.82, 95% CI 0.69-0.98) and signs or symptoms (OR 0.78, 95% CI 0.68-0.90) were significantly associated with early clinical stability. Patients with early clinical stability had lower 90-days mortality (3.4% vs. 11.9%, p&lt;0.001), fewer admissions to the intensive care unit (2.7% vs. 8.0%, p = 0.005) and a shorter length of stay (6.0 days, IQR 4.0-10.0 vs. 10.0 days, IQR 7.0-15.0, p&lt;0.001). Patients with younger age, less co-morbidity, fewer signs or symptoms, less respiratory compromise, and a lower platelet count are more likely to reach early clinical stability. Patients without early clinical stability have a worse prognosis and warrant close scrutiny

Retrospective review of paediatric case reports of Stevens-Johnson syndrome and toxic epidermal necrolysis with lamotrigine from an international pharmacovigilance database

Objectives This study aims to characterise paediatric reports with lamotrigine (LTG) and Stevens-Johnson syndrome or toxic epidermal necrolysis (SJS/TEN), and to explore whether potential risk factors can be identified. Design This is a retrospective review of suspected adverse drug reaction (ADR) reports. Reported time from LTG start to SJS/TEN onset, indication for use and dose was explored. To identify potential risk groups, report features (eg, ages, patient sex, co-reported drugs) for LTG and SJS/TEN were contrasted with two reference groups in the same database, using shrinkage logOR. Setting Reports were retrieved from VigiBase, the WHO global database of individual case safety reports, in January 2015. Patients Data for patients aged ≤17 years old were extracted. Results There were 486 reports of SJS/TEN in LTG-treated paediatric patients. Ninety-seven per cent of the cases with complete information on time to onset of SJS/ TEN occurred within 8 weeks of initiation of LTG therapy. The median time to onset was 15 days (IQR: 10–22 days). The proportion of SJS/TEN with LTG and valproic acid (VPA) co-reporting was significantly more than non-cutaneous ADRs (43% vs 19%, (logOR: 1.60 (99% CI: 1.33 to 1.84)). Conclusions The results suggest that VPA co-medication with LTG therapy is a risk factor for SJS/TEN in the paediatric population. Although this relationship has been identified from individual case reports, this is the first supportive study from a large compilation of cases. SJS/TEN risk is highest in first 8 weeks of treatment with LTG in children and clinicians should be aware of this risk during this period

β-Lactam Monotherapy vs β-Lactam-Macrolide Combination Treatment in Moderately Severe Community-Acquired Pneumonia: A Randomized Noninferiority Trial.

IMPORTANCE: The clinical benefit of adding a macrolide to a β-lactam for empirical treatment of moderately severe community-acquired pneumonia remains controversial. OBJECTIVE: To test noninferiority of a β-lactam alone compared with a β-lactam and macrolide combination in moderately severe community-acquired pneumonia. DESIGN, SETTING, AND PARTICIPANTS: Open-label, multicenter, noninferiority, randomized trial conducted from January 13, 2009, through January 31, 2013, in 580 immunocompetent adult patients hospitalized in 6 acute care hospitals in Switzerland for moderately severe community-acquired pneumonia. Follow-up extended to 90 days. Outcome assessors were masked to treatment allocation. INTERVENTIONS: Patients were treated with a β-lactam and a macrolide (combination arm) or with a β-lactam alone (monotherapy arm). Legionella pneumophila infection was systematically searched and treated by addition of a macrolide to the monotherapy arm. MAIN OUTCOMES AND MEASURES: Proportion of patients not reaching clinical stability (heart rate &lt;100/min, systolic blood pressure &gt;90 mm Hg, temperature &lt;38.0°C, respiratory rate &lt;24/min, and oxygen saturation &gt;90% on room air) at day 7. RESULTS: After 7 days of treatment, 120 of 291 patients (41.2%) in the monotherapy arm vs 97 of 289 (33.6%) in the combination arm had not reached clinical stability (7.6% difference, P = .07). The upper limit of the 1-sided 90% CI was 13.0%, exceeding the predefined noninferiority boundary of 8%. Patients infected with atypical pathogens (hazard ratio [HR], 0.33; 95% CI, 0.13-0.85) or with Pneumonia Severity Index (PSI) category IV pneumonia (HR, 0.81; 95% CI, 0.59-1.10) were less likely to reach clinical stability with monotherapy, whereas patients not infected with atypical pathogens (HR, 0.99; 95% CI, 0.80-1.22) or with PSI category I to III pneumonia (HR, 1.06; 95% CI, 0.82-1.36) had equivalent outcomes in the 2 arms. There were more 30-day readmissions in the monotherapy arm (7.9% vs 3.1%, P = .01). Mortality, intensive care unit admission, complications, length of stay, and recurrence of pneumonia within 90 days did not differ between the 2 arms. CONCLUSIONS AND RELEVANCE: We did not find noninferiority of β-lactam monotherapy in patients hospitalized for moderately severe community-acquired pneumonia. Patients infected with atypical pathogens or with PSI category IV pneumonia had delayed clinical stability with monotherapy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00818610

Participatory analysis for adaptation to climate change in Mediterranean agricultural systems: possible choices in process design (versão Pre Print)

There is an increasing call for local measures to adapt to climate change, based on foresight analyses in collaboration with actors. However, such analyses involve many challenges, particularly because the actors concerned may not consider climate change to be an urgent concern. This paper examines the methodological choices made by three research teams in the design and implementation of participatory foresight analyses to explore agricultural and water management options for adaptation to climate change. Case studies were conducted in coastal areas of France, Morocco, and Portugal where the groundwater is intensively used for irrigation, the aquifers are at risk or are currently overexploited, and a serious agricultural crisis is underway. When designing the participatory processes, the researchers had to address four main issues: whether to avoid or prepare dialogue between actors whose relations may be limited or tense; how to select participants and get them involved; how to facilitate discussion of issues that the actors may not initially consider to be of great concern; and finally, how to design and use scenarios. In each case, most of the invited actors responded and met to discuss and evaluate a series of scenarios. Strategies were discussed at different levels, from farming practices to aquifer management. It was shown that such participatory analyses can be implemented in situations which may initially appear to be unfavourable. This was made possible by the flexibility in the methodological choices, in particular the possibility of framing the climate change issue in a broader agenda for discussion with the actors

Conceptual design of the liquid metal laboratory of the TECHNOFUSION facility

The application of liquid metal technology in fusion devices requires R&D related to many phenomena: interaction between liquid metals and structural material as corrosion, erosion and passivation techniques; magneto-hydrodynamics; free surface fluid-dynamics and any other physical aspect that will be needed for their safe reliable operation. In particular, there is a significant shortage of experimental facilities dedicated to the development of the lithium technology. In the framework of the TECHNOFUSION project, an experimental laboratory devoted to the lithium technology development is proposed, in order to shed some light in the path to IFMIF and the design of chamber's first wall and divertors. The conceptual design foresee a development in two stages, the first one consisting on a material testing loop. The second stage proposes the construction of a mock-up of the IFMIF target that will allow to assess the behaviour of a free-surface lithium target under vacuum conditions. In this paper, such conceptual design is addressed