Conditions d’emploi de l’approximation de l’état quasi-stationnaire : cas du réacteur dynamique parfaitement agité

On montre que l’emploi de l’approximation de l’état quasi-stationnaire, lors du calcul d’un réacteur dynamique parfaitement agité à partir d’un mécanisme réactionnel, est légitime pour une réaction non explosive et lorsque le temps de passage est supérieur à une valeur appelée « période d’induction ». On établit les conditions pour lesquelles une réaction devient explosive. On montre que la période d’induction est fonction de la précision de calcul demandée, de la vitesse des processus d’amorçage et des constantes de vitesse des processus de ramification et de terminaison du mécanisme

An embryonic fold and thrust belt south of the Himalayan morphological front: Examples from the Central Nepal and Darjeeling piedmonts

International audienceThe morphological boundary between the Himalayas and the foreland plain is well expressed and most often corresponds to the frontal emergence of the Main Himalayan Thrust (MHT). This boundary is affected by surface ruptures during very large Himalayan earthquakes (Mw > 8) that regularly induce (with a recurrence of the order of 500 to 1200 years) the uplift of the foothills relative to the plain. However, a thrust-fold system is hidden beneath the plain and is displayed by the seismic profiles of oil companies in east/central Nepal and by H/V passive geophysical techniques in Darjeeling. Its long-term kinematic evolution is slow, with a tectonic uplift of the hanging wall that is lower than the subsidence rate of the foreland basin, that is, less than approximately half a millimetre per year. During phases of low sedimentation controlled by climatic fluctuations, the morphological surfaces of the piedmont are incised by large rivers for several tens of metres; therefore, structures hidden under the sediments emerge slightly in the plain. The evolution of the hidden structures corresponds to an embryonic thrust belt mainly affected by a long-term shortening rate of 1.4 +2.5/-1.2 mm·yr-1, that is, 2-20% of the shortening rate of the entire Himalayan thrust system. Nonetheless, the details of the deformation associated with the embryonic thrust belt are still poorly understood. Several deformation components could affect the central Himalayan and Darjeeling piedmonts. i) Any slow steady-state deformation, such as layer parallel shortening (LPS) is not detected by Global Navigation Satellite System (GNSS) data, and such deformation would therefore absorb less than 0.5 mm·yr-1. The geodetic data that suggest the aseismic growth of some of the structures are highly controversial. ii) For the rest of the deformation of the embryonic thrust wedge, it is yet to be proven whether deformation occurs during rare great earthquakes affecting the piedmont during medium earthquakes and/or during post-seismic deformation related to great earthquakes. The amplitude of this long-term low deformation is too limited to significantly reduce the seismic hazard in the seismic gaps of the Himalayan belt. iii) In some portions of the Himalayan front, such as Darjeeling (India), the thrust deformation related to great earthquakes propagates several tens of kilometres south of the morphological front in the zone previously affected by the long-term low deformation. It induces multi-metre surface ruptures in the piedmont and a mean shortening of 8.5 ± 6.2 mm·yr-1. iiii) Pre-existing faults in the bedrock of the Indian craton, often oblique to the Himalayan structures, are locally reactivated beneath the foreland plain with low deformation rates

A hidden fold and thrust belt south of the Himalayan morphological front: The examples of Central Nepal and Darjeeling piedmonts

International audienc

A hidden fold and thrust belt south of the Himalayan morphological front: The examples of Central Nepal and Darjeeling piedmonts

International audienc

A hidden fold and thrust belt south of the Himalayan morphological front: The examples of Central Nepal and Darjeeling piedmonts

International audienc

What are the ethical dimensions in the profession of intensive care specialist?

International audienceTwo essential components of the profession of a medical doctor are the constant review of the patient's therapeutic project, and collaboration between healthcare professionals. The profession of intensive care unit (ICU) physician goes further in terms of responsibility, vis-à-vis the intensive treatments dispensed to the patients, and the physician's responsibilities towards the patient's family and the caregiving team, also bearing in mind that ICU care is costly in terms of human and financial resources. In this review, we address the profession of ICU physician from the perspective of the ethical questions that arise constantly, focusing on the timeframe of the reflection process. Firstly, admission to the ICU must be anticipated. The concept of advance care planning is a suitable tool for this, and in case of non-admission to the ICU, does not by any means constitute an abandonment of the patient, because palliative care can also be anticipated, with a view to avoiding suffering for the patient and their family. Next, during an ICU stay, while the technical aspects undoubtedly characterise the ICU best at the start of the patient's stay, the process of reflection rapidly becomes preponderant, and involves the analysis of often complex situations with a view to defining the level of therapeutic engagement and optimizing the care dispensed to the patient. Last, a further ethical issue concerns the decision to re-admit (or not) a patient to the ICU. This decision can be made, for example, in the framework of a systematic, formalised, structured, multidisciplinary meeting at the end of an ICU stay, using a similar procedure to that implemented for decisions relating to withholding or withdrawal of life-sustaining therapies. The profession of ICU physician is not simply a question of prolonging or sustaining life, but is also fraught with ethical questions about how best to employ their competences. In this regard, it is essential to foster interdisciplinary collaboration, and emphasise the need for ICU physicians to be involved in the development of therapeutic projects, particularly when the disease in question is likely to be complicated by acute situations that may require admission of the patient to the ICU

Terres mégalithes

Le film "Terres Mégalithes" explore le paysage mégalithique vendéen il y a 6500 ans. Le film projeté au CAIRN (http://www.cairn-prehistoire.com/) en Vendée fait découvrir au spectateur un inventaire unique de l'ensemble des monuments mégalithiques du Pays Talmondais, avec ses dolmens et ses menhirs.Le spectateur explore ensuite l'intérieur du Pey de Fontaine, monument funéraire au cairn intégralement restitué en 3D. La symbolique de ces espaces réservés aux morts s'entrecroise avec l'importance de ces architectures puissantes pour les communautés qui les ont érigées.Intégrant numérisations 3D, restitutions 3D et cartes iconographiques, "Terres Mégalithes" évoque le témoignage de 1000 ans d'histoire

Future Strategic Priorities of the Swiss Decentralized Healthcare System: A COVID-19 Case Study

The COVID-19 pandemic exposed a multitude of vulnerabilities in Switzerland’s decentralized healthcare system and highlighted the urgent need to strengthen Switzerland’s capacity to respond to health crises and disease outbreaks. In this article, we draw on three distinct areas of analysis of the current functioning of the Swiss healthcare system to examine its strengths and weaknesses, which can serve as a basis for future considerations and strategic priorities. First, we analyze the different levels of nine non-pharmaceutical interventions (NPIs), as defined by the ETH KOF Stringency Index and implemented in the Swiss cantons of Zurich, Vaud, and Ticino, compared with the rate of positive COVID-19 cases, hospitalizations, and deaths. We find that there was no strong correlation between the severity of the nine non-pharmaceutical interventions implemented and lower rates of positive COVID-19 cases, hospitalizations, and deaths. Second, we examine the challenges of Switzerland’s decentralized healthcare system through a literature review and with empirical data obtained from semi-structured interviews with health professionals in Switzerland. We conclude our analysis with the role of central authorities during the COVID-19 pandemic. The results demonstrate that during a national emergency in Switzerland, taking into account other factors that influence the success of a pandemic strategy, there is an opportunity for a more unified, centralized response to reduce the social and economic toll of the pandemic without necessarily risking greater health damage. We recommend that the Swiss federal government use a combination of decentralized and centralized public health and policy approaches and promote greater private–public collaboration with direct communication channels among policymakers, public health stakeholders, and the public to improve pandemic preparedness and response

Adaptive mesh generation for curved domains

This paper considers the technologies needed to support the creation of adaptively constructed meshes for general curved three-dimensional domains and outlines one set of solutions for providing them. A brief review of an effective way to integrate mesh generation/adaptation with CAD geometries is given. A set of procedures that support general h-adaptive refinement based on a mesh metric field is given. This is followed by examples that demonstrate the ability of the procedures to adaptively construct anisotropic meshes for flow problems. A procedure for the generation of strongly graded, curved meshes as needed for effective hp-adaptive simulations is also given. (C) 2004 IMACS. Published by Elsevier B.V. All rights reserved