French birds lag behind climate warming

Biodiversity responses to climate warming have been documented through the study of changes in distributions, abundances or phenologies of individual species or in more integrated measures such as species community richness and composition. However, whether these observed population and community changes are occurring fast enough to cope with new climatic conditions remain uncertain and hardly quantifiable. Here, using spatial and temporal trends from the French breeding bird survey, we show that although bird assemblages are strongly responding to climate warming, this response is slower than expected for catching up with the current temperature increase. During the last two decades, French birds have only achieved 54% of the response required to follow temperature increase, and have accumulated, in 18 years, a 97 km delay in their northward shift. We thus developed a framework to measure both the observed and predicted response of species assemblage to climate change, an approach which is flexible enough to be applicable to any taxa with large-scale survey data, using either abundance or distribution data. For example, it can be further used to test if different delays are found across groups or if, for a given group, the delay depends on the land-use contexts

Introduction: urban crises, policing crises: mirror images? (c. 1700–1900): cities in flux and changes to policing

[V. Denis, V. Milliot et C. Lucrezio Monticelli (dir.), Special section on policing and urban crisis, Urban History, volume 43, issue 2, May 2016, p. 200-305. En savoir plus https://www.cambridge.org/core/journals/urban-history/issue/4BF2E88B7804439C0E4F27CD68107F47 (consulté le 10/10/2016)]The articles gathered here aim at outlining a complex view of the relationship between cities in a state of ‘crisis’ and changes to policing systems, in a period marked by rapid urbanization and industrialization. They explore the connections between the rhythms of urban change and the changes in the institutions responsible for policing the city. This introduction defines ‘urban crisis’ as a brief paroxysm and a way of describing rapid urban change that is considered problematic especially in terms of social control. It examines three sets of issues to highlight the relationships between policing powers and urban dynamics: first, how the police managed to handle unforeseen, traumatic events in emergency situations; second, how the police forces tried to legitimize their status through their understanding and control of urban dynamics; and third, how the police used the discourse of urban crisis they helped to produce, as a tool for their own ends

Perception, understanding and initiatives with regard to sustainable development: A profile of Québec tourism organizations

The concept of sustainable development is not new. However, its application in the field of tourism in Québec needs to be clarified. This way, this study is aimed at drawing the profile of Québec tourist organizations, at comparing the initiatives developed according to various perspectives (environmental, social and economic) and finally, to verify the coherence between the level of importance these organizations give to the concepts of sustainable development and the application of these within their environment. Generally, we can assert that a majority of initiatives connected to sustainable development of tourism are applied by tourist companies and organizations. It is thus possible to notice a growing desire on behalf of the organizations to get involved, through their initiatives and actions, for the sustainable development of the industry. However, the environmental and economic dimensions of these initiatives turn out to be the most recommended without knowing the socio-cultural dimension to which they are connected. As a matter of fact, Québec tourist organizations understand the importance of their actions without forgetting that a precision of the evolution of sustainable tourism over time would reveal the impact of the international symposium on the sustainable development with the tourist organizations

Minkowski sum of HV-polytopes in Rn

Minkowski sums cover a wide range of applications in many different fields like algebra, morphing, robotics, mechanical CAD/CAM systems ... This paper deals with sums of polytopes in a n dimensional space provided that both H-representation and V-representation are available i.e. the polytopes are described by both their half-spaces and vertices. The first method uses the polytope normal fans and relies on the ability to intersect dual polyhedral cones. Then we introduce another way of considering Minkowski sums of polytopes based on the primal polyhedral cones attached to each vertex.Comment: 4th Annual International Conference on Computational Mathematics, Computational Geometry and Statistics, Jan 2015, Singapore, Singapor

Heat Estimation from Infrared Measurement Compared to DSC for Austenite to R Phase Transformation in a NiTi Alloy

International audienceHeat sources estimations from temperature field measurements deduced from infrared imaging are increasingly used to study thermo-mechanical coupling during materials deformation. These estimations are based on approximations of the derivative terms with respect to time and space which are involved in the heat diffusion equation. This paper proposes a first experimental validation of this method by applying it to an experimental uniform air cooling of a NiTi Shape Memory Alloy thin plate. In the studied cooling temperate range, heat sources are due to Austenite to R phase transformation. Transformation temperatures, heat sources and energies are estimated from infrared temperature measurements and compared to differential scanning calorimetry results. The small 2 discrepancies are mainly explained by errors in DSC measurements due to thermal inertia and baseline determination

Identification and validation of a continuum damage model applied for the lifetime prediction of H11 tool steel

Extrait de : Proceedings of 7th International tooling conference : tooling materials and their applications from research to market / sous la dir. de M. ROSSO, M. ACTIS GRANDE et D. UGUES. - 7th International tooling conference on tooling materials and their applications from research to market, Torino, ITALIE, 2-5 May 2006International audienceThis paper describes the work performed to identify and validate a non-isothermal continuum damage model for a widely used hot-work tool steel H11 at a hardness of 47 HRc. The investigation is based on an extensive high-temperature low-cycle fatigue database performed under strain rate controlled tests with and without dwell times in the range of 300°C-600°C. The approach gives a good description of the thermomechanical behaviour of H11 tool steel under various test conditions and constitutes a very good prediction tool for a very large amount of fatigue tests. This work is divided into three stages. First, isothermal fatigue tests are performed on flat specimens in order to identify lifetime model parameters. Then, thermo mechanical fatigue tests are considered in order to validate the model in a non-isothermal case. Lastly, low-cycle fatigue tests are carried out on notched specimens in order to investigate the model capabilities in a multiaxial condition