The GenTree Platform: growth traits and tree-level environmental data in 12 European forest tree species

Background: Progress in the field of evolutionary forest ecology has been hampered by the huge challenge of phenotyping trees across their ranges in their natural environments, and the limitation in high-resolution environmental information. Findings: The GenTree Platform contains phenotypic and environmental data from 4,959 trees from 12 ecologically and economically important European forest tree species: Abies alba Mill. (silver fir), Betula pendula Roth. (silver birch), Fagus sylvatica L. (European beech), Picea abies (L.) H. Karst (Norway spruce), Pinus cembra L. (Swiss stone pine), Pinus halepensis Mill. (Aleppo pine), Pinus nigra Arnold (European black pine), Pinus pinaster Aiton (maritime pine), Pinus sylvestris L. (Scots pine), Populus nigra L. (European black poplar), Taxus baccata L. (English yew), and Quercus petraea (Matt.) Liebl. (sessile oak). Phenotypic (height, diameter at breast height, crown size, bark thickness, biomass, straightness, forking, branch angle, fructification), regeneration, environmental in situ measurements (soil depth, vegetation cover, competition indices), and environmental modeling data extracted by using bilinear interpolation accounting for surrounding conditions of each tree (precipitation, temperature, insolation, drought indices) were obtained from trees in 194 sites covering the species’ geographic ranges and reflecting local environmental gradients. Conclusion: The GenTree Platform is a new resource for investigating ecological and evolutionary processes in forest trees. The coherent phenotyping and environmental characterization across 12 species in their European ranges allow for a wide range of analyses from forest ecologists, conservationists, and macro-ecologists. Also, the data here presented can be linked to the GenTree Dendroecological collection, the GenTree Leaf Trait collection, and the GenTree Genomic collection presented elsewhere, which together build the largest evolutionary forest ecology data collection available

Between but not within species variation in the distribution of fitness effects

New mutations provide the raw material for evolution and adaptation. The distribution of fitness effects (DFE) describes the spectrum of effects of new mutations that can occur along a genome, and is therefore of vital interest in evolutionary biology. Recent work has uncovered striking similarities in the DFE between closely related species, prompting us to ask whether there is variation in the DFE among populations of the same species, or among species with different degrees of divergence, i.e., whether there is variation in the DFE at different levels of evolution. Using exome capture data from six tree species sampled across Europe we characterised the DFE for multiple species, and for each species, multiple populations, and investigated the factors potentially influencing the DFE, such as demography, population divergence and genetic background. We find statistical support for there being variation in the DFE at the species level, even among relatively closely related species. However, we find very little difference at the population level, suggesting that differences in the DFE are primarily driven by deep features of species biology, and that evolutionarily recent events, such as demographic changes and local adaptation, have little impact

Simulation numérique du coup de bélier sur un réservoir rempli par une balle OTAN

Le problème de couplage fluide-structure est celui d'un impact balistique par une balle de calibre OTAN 7.62 mm sur un réservoir rempli. La simulation reproduit l'érosion de la balle au moment de la perforation de la paroi, sa dislocation pendant la traversée du fluide, le front de pression et les zones de cavitation dans le fluide. Les résultats numériques sont comparés à l'expérimentation

On a wave-based reduced order model for transient effects computation including mid frequencies

International audienc

La chaîne opératoire funéraire: ethnologie et archéologie de la mort

International audienceComplexe, la chaîne opératoire funéraire assure à la fois une transformation matérielle, celle du corps du défunt, et une transformation idéelle qui concerne son âme ou principe vital et sa place, laissée vide, dans la société. Sa restitution, son bornage et son découpage dépendent à la fois de la nature des funérailles, du projet des acteurs et, dans une certaine mesure, du choix de l’observateur, ethnologue ou archéologue.Cet ouvrage présente un découpage de la chaîne en plusieurs étapes centrées sur le corps mort, marquant ses changements progressifs, toutes indispensables au bon déroulement de la transformation du défunt. Ainsi, au fil des 16 contributions, sont illustrés : la préparation du corps ; la transformation du cadavre ; le devenir des restes ; le souvenir du mort ; grâce à des exemples ethnologiques et archéologiques variés, fruits des travaux des chercheurs de la Maison Archéologie & Ethnologie, René-Ginouvès. (Source : 4e de couverture

Introduction : la chaîne opératoire funéraire

International audienceLa mort est une dimension humaine centrale autour de laquelle toutes les sociétés ont développé un ensemble de croyances et de pratiques, souvent très élaborées et très codifiées. Le « travail du deuil » engage généralement la communauté au-delà des proches du défunt. Il tend à réaliser la séparation entre les morts et les vivants. Enfin, il « construit » le défunt ou mort en ancêtre. Cette exigence a été identifiée dans le travail pionnier de Robert Hertz et sa théorie des doubles funérailles : l'âme du mort est dangereuse pendant une période intermédiaire, ce sont les deuxièmes funérailles qui, en le transformant en ancêtre, en font une entité bienfaisante pour les vivants.Le devenir du corps mort, sa thanatomorphose, est également un sujet central de préoccupation. Le cadavre est le support de représentations diverses, voire de fantasmes, propres à chaque culture, qui vont conditionner les différents types de traitement que l'on va lui faire subir. C'est par l'analyse de ces différents traitements que nous tentons ici de déchiffrer les solutions qu'ont élaborées les sociétés, selon deux approches rarement combinées, celle de l'ethnologie et celle de l'archéologie. Un même fil directeur a conduit ces travaux dont les contextes culturels et géographiques sont variés : celui d'une chaîne opératoire funéraire

Experimental and numerical study of compression after impact of sandwichs structures with metallic skins

A finite element model is proposed to determine the residual print of sandwich structures with Nomex honeycomb core and metallic skins indented by a spherical indenter and to simulate its behavior when this indented structure is subjected to lateral compressive loading (known as CAI/ Compression after impact). The particularities of this model rely on representing the honeycomb with a grid of nonlinear springs which its behavior law calibrated from uniform compression test. This simple model, after integrating the cycle behavior law of honeycomb, allows predicting the geometry of residual print with a good precision. This model is then developed to propose a complete computation from indentation, residual print geometry to lateral compressive loading after indentation (CAI). This model also allows predicting numerically the residual strength of structure in CAI and the elliptical evolution of residual print geometry during CAI loading. A good correlation with test results is obtained except for the very small residual print depth

Discrete modeling of the crushing of nomex honeycomb core and application to impact and post-impact behavior of sandwich structures

In this chapter, an original method for modeling the behavior of sandwich structures during and after impact is proposed and validated. It is based on the demonstration that Nomex honeycomb behaves in a post-buckling mode very early and that compression forces are taken up by the corners or vertical edges of the honeycomb cells in the same way as they are in the stiffeners in aircraft structures. Thus it is possible to represent the honeycomb discretely by a grid of springs located at the six corners of hexagonal cells. This approach represents the phenomenon of indentation on honeycomb alone or on sandwiches very well. This approach provides an understanding of how the sandwich and the core behave under compression after impact. An original criterion based on a local core crush is tested and validated to compute the residual strength. To consider the bending response of sandwich structures, a multi-level approach is also proposed