Éditeur(s) : HAL CCSD European Geosciences Union
Résumé : International audience
We calculated the seismic properties of 47 mantle xenoliths from 9 kimberlitic pipes in the Kaapvaal craton based on their modal composition, the crystal-preferred orientations (CPO) of olivine, ortho- and clinopyroxene, and garnet, the Fe content of olivine, and the pressures and temperatures at which the rocks were equilibrated. These data allow constraining the variation of seismic anisotropy and velocities within the cratonic mantle. The fastest P and S2 wave propagation directions and the polarization of fast split shear waves (S1) are always subparallel to olivine [100] axes of maximum concentration, which marks the lineation (fossil flow direction). Seismic anisotropy is higher for high olivine contents and stronger CPO. Maximum P wave azimuthal anisotropy (AVp) ranges between 2.5 and 10.2% and the maximum S wave polarization anisotropy (AVs), between 2.7 and 8%. Changes in olivine CPO symmetry result in minor variations in the seismic anisotropy patterns, mainly in the apparent isotropy directions for shear wave splitting. Seismic properties averaged over 20 km-thick depth sections are, therefore, very homogeneous. Based on these data, we predict the anisotropy that would be measured by SKS, Rayleigh (SV) and Love (SH) waves for five endmember orientations of the foliation and lineation. Comparison to seismic anisotropy data from the Kaapvaal shows that the coherent fast directions, but low delay times imaged by SKS studies, and the low azimuthal anisotropy with with the horizontally polarized S waves (SH) faster than the vertically polarized S wave (SV) measured using surface waves are best explained by homogeneously dipping (45°) foliations and lineations in the cratonic mantle lithosphere. Laterally or vertically varying foliation and lineation orientations with a dominantly NW-SE trend might also explain the low measured anisotropies, but this model should also result in backazimuthal variability of the SKS splitting data, not reported in the seismological data. The strong compositional heterogeneity of the Kaapvaal peridotite xenoliths results in up to 3% variation in density and in up to 2.3% variation of Vp, Vs, and Vp / Vs ratio. Fe depletion by melt extraction increases Vp and Vs, but decreases the Vp / Vs ratio and density. Orthopyroxene enrichment due to metasomatism decreases the density and Vp, strongly reducing the Vp / Vs ratio. Garnet enrichment, which was also attributed to metasomatism, increases the density, and in a lesser extent Vp and the Vp / Vs ratio. Comparison of density and seismic velocity profiles calculated using the xenoliths' compositions and equilibration conditions to seismological data in the Kaapvaal highlights that (i) the thickness of the craton is underestimated in some seismic studies and reaches at least 180 km, (ii) the deep sheared peridotites represent very local modifications caused and oversampled by kimberlites, and (iii) seismological models probably underestimate the compositional heterogeneity in the Kaapvaal mantle root, which occurs at a scale much smaller than the one that may be sampled seismologically.
ISSN: 1869-9510

hal-01053516
https://hal.archives-ouvertes.fr/hal-01053516
DOI : 10.5194/se-5-45-2014

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The Convective and Orographically-driven Precipitation Study (COPS) carried out in summer 2007 over northeastern France and southwestern Germany provided a fairly comprehensive description of the low-troposphere water-vapour field, thanks in particular to the deployment of two airborne differential absorption lidar systems. These lidar observations were assimilated using the 3D-Var assimilation system of the Application of Research to Operations at MEsoscale (AROME) numerical weather prediction mesoscale model. The assimilation was carried out for the period 4 July-3 August by running a three-hour forward intermittent assimilation cycle. First, the impact of the lidar observations was assessed by comparing the analyses with a set of more than 200 independent soundings. The lidar observations were found to have a positive impact on the analyses by reducing the dry bias in the first 500 m above ground level and by diminishing the root-mean-square error by roughly 15% in the first km. Then the impact of the lidar observations was assessed by comparing the precipitation forecasts (obtained with and without the lidar observations for the period 15 July-2 August) with the gridded precipitation observations provided by the Vienna Enhanced Resolution Analysis. In general, the impact was found to be positive but not significant for the 24 h precipitation and positive and significant for the 6 h precipitation, with an improvement lasting up to 24 h. Some selected case studies show that the improvement was obtained through a better depiction of convection initiation or through a more accurate positioning of the precipitation systems
ISSN: 0035-9009

hal-00659497
https://hal.archives-ouvertes.fr/hal-00659497
DOI : 10.1002/qj.1864

Éditeur(s) : Université des Antilles
Résumé : Una introducción a la seguridad turística requiere que nos ocupemos de una revisión bibliográfica. Ciertamente, los planes y los manuales parecen no traducirse en protocolos en momentos de emergencia. Ello sucede pues siempre un estado de emergencia se escapa de toda planificación pero también suele suceder por la falta de definiciones claras respecto a que es la seguridad. En este ensayo, discutiremos los paradigmas y tesis centrales de tres exponentes que han dedicado su vida a dicha tarea. Sevil Somnez, Abraham Pizam y Peter Tarlow han explorado las raíces del terrorismo y la seguridad por más de 20 años, y por eso, a pesar de la crítica, merecen su reconocimiento. La mejor forma de homenajearlos es discutir críticamente sus postulados. Con sus puntos de divergencia, los especialistas se encuentran preocupados por la dependencia occidental del terrorismo con los medios masivos de comunicación, aspecto a discutir en el presente trabajo de revisión.
Une introduction à la sécurité touristique nécessite un examen bibliographique. Certainement, les plans et les manuels semblent ne pas être traduits dans des protocoles de moments de secours. Il s’agit donc toujours d’état d'urgence confronté à l’évènement, sans planification et sans définitions claires de ce qu’est la sécurité. Dans cet essai, nous discuterons les paradigmes et les thèses centrales de trois auteurs qui ont consacré leur vie à la tâche mentionnée ci-dessus. Sevil Somnez, Abraham Pizam et Peter Tarlow ont exploré les racines du terrorisme et la sécurité pendant plus de 20 ans et pour cela, en dépit de la critique, ils méritent notre reconnaissance. La meilleure façon de leur rendre hommage est de discuter de manière critique de leurs postulats. Au-delà de leurs divergences, les spécialistes s’inquiètent de la dépendance occidentale au terrorisme sous le poids des mass-médias, aspect qu’il convient de discuter dans le présent travail de révision.
The specialized literature review is of paramount importance at time of exploring the current problems of tourism security. Certainly, plans and policies provided by guide-books are not being followed in disaster-contests simply chaos and disorder are the nature of emergencies. Beyond any protocol, crises and security are not properly defined by scholars. In this essay-review, we will not pay attention to define what tourism security means, lest by the lens of three senior scholars, Sevil Somnez, Abraham Pizam and Peter Tarlow, who have accomplished this task. They have explored not only the roots of terrorism but security over 20 years. Despite the criticism, they deserve recognition for this legacy. Based on substantial point of divergence, these specialists are concerned by the financial dependency of societies respecting to mass-media and its coverage of terrorist attacks.

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.7530
http://etudescaribeennes.revues.org/7530

Éditeur(s) : HAL CCSD Ecological Society of America
Résumé : CABI:20153174020
Understanding how plants are constructed - i.e., how key size dimensions and the amount of mass invested in different tissues varies among individuals - is essential for modeling plant growth, carbon stocks, and energy fluxes in the terrestrial biosphere. Allocation patterns can differ through ontogeny, but also among coexisting species and among species adapted to different environments. While a variety of models dealing with biomass allocation exist, we lack a synthetic understanding of the underlying processes. This is partly due to the lack of suitable data sets for validating and parameterizing models. To that end, we present the Biomass And Allometry Database (BAAD) for woody plants. The BAAD contains 259634 measurements collected in 176 different studies, from 21084 individuals across 678 species. Most of these data come from existing publications. However, raw data were rarely made public at the time of publication. Thus, the BAAD contains data from different studies, transformed into standard units and variable names. The transformations were achieved using a common workflow for all raw data files. Other features that distinguish the BAAD are: (i) measurements were for individual plants rather than stand averages; (ii) individuals spanning a range of sizes were measured; (iii) plants from 0.01-100 m in height were included; and (iv) biomass was estimated directly, i.e., not indirectly via allometric equations (except in very large trees where biomass was estimated from detailed sub-sampling). We included both wild and artificially grown plants. The data set contains the following size metrics: total leaf area; area of stem cross-section including sapwood, heartwood, and bark; height of plant and crown base, crown area, and surface area; and the dry mass of leaf, stem, branches, sapwood, heartwood, bark, coarse roots, and fine root tissues. We also report other properties of individuals (age, leaf size, leaf mass per area, wood density, nitrogen content of leaves and wood), as well as information about the growing environment (location, light, experimental treatment, vegetation type) where available. It is our hope that making these data available will improve our ability to understand plant growth, ecosystem dynamics, and carbon cycling in the world's vegetation.
ISSN: 0012-9658

hal-01535227
https://hal.archives-ouvertes.fr/hal-01535227
DOI : 10.1890/14-1889.1
PRODINRA : 306122

Résumé : Arbol 5 a 10 m, el tronco generalmente delgado e irregular. Hojas alternas, pinnadas, oblongas, pecíolo corto; folíolos opuestos, numerosos, corto peciolados, de 1 a 2 cm, obtusos, enteros, pálidos. Flores numerosas, blancas, aromáticas, en panículas axilares; pétalos ligeramente más largos que los sépalos. Cápsula linear, triquetra, pendiente, de hasta 45 cm de largo, dehiscente, de color amarillo-cenizo; semillas generalmente aladas, oleaginosas.
Arbre de 5 à 10 m de haut, tronc généralement fin et irrégulier. Feuilles alternes, pennées, oblongues, à pétiole court; nombreuses folioles opposées, à court pétiole, de 1 à 2 cm, obtuses, entières, pâles. Fleurs nombreuses, blanches, aromatiques, disposées en panicules axillaires; pétales légèrement plus longs que les sépales. Capsule linéaire, à trois angles arrondis, pendante, pouvant atteindre 45 cm de long, déhiscente, jaune cendré; graines généralement ailées, oléagineuses.
Tree, 5-10 m high, trunk brittle, root with taste and odour of horseraddish. Leaves deciduous, alternate, 30-60cm long, compound 3-pinnate, leaflets opposite, numerous, short-petiolate, 1-2.5 cm x 0.6-1.5 cm, variable in shape; inflorescence a panicle, axillary, flowers fragrant numerous, petals white,14-18 mm x 6-8 mm; fruit a linear capsule, triquetrous, 20- 45 cm long, 2 cm thick, usually pendulous tan; seeds globular 10 mm in diameter usually winged.
Nativo del noroeste de la India, comúnmente se cultiva en las regiones tropicales de todo el mundo.
Originaire du nord-ouest de l’;Inde, habituellement cultivé dans les régions tropicales du monde entier.
Native to northwest India, usually culti

http://www.tramil.net/fototeca/plant237

Éditeur(s) : HAL CCSD
Résumé : International audience
ABSTRACT :A satellite retrieval of surface solar irradiance (SSI) based on GOES satellite data is presented and validated for the French Guiana with three years of in situ measurements from six ground stations. We propose a particle filter approach combining GOES satellite observations and in situ data. We propose an original observation function based on a joint probability distribution and taking advantages of the characteristics of both the involved type of data. The statistical results are compared with those of existing estimation methods and they are found to be in accordance with them. The daily bias ranges from -12 W/m² (-6% of the mean of measurements) to 12 W/m² (6%), depending on the stations. The daily root mean square difference ranges between 23 W/m² (10%) and 27 W/m² (15%). The correlation coefficient is close to 0.92. There is no seasonal climatic effect on the method, the bias and RMSD remain similar for both the rainy and the dry season, but better correlation is observed in the rainy season than in the dry season. Uncertainties are mainly due to the presence of specific tropical atmospheric conditions during the dry season. The method has been tested through various tests: cross-validation scheme has highlighted the potential generalization of the model in a temporal dimension; the ability of the method to effectively duplicate anomalies in surface solar irradiance time series has also been tested. The robustness of the results shows the interest of the method compared to other existing estimation methods. Because of its simplicity of implementation this method opens new prospects in estimating surface solar irradiance. It is concluded that using a particle filter and original observation function method allow a high-quality surface solar irradiance estimation in French Guiana.RESUMEUne méthode d'estimation de l'irradiance solaire de surface (SSI) à partir de données satellites GOES est présentée et validée par comparaison avec trois années de mesures in situ provenant de six stations météorologiques de Guyane Française. Dans cet article, nous proposons une approche par filtre particulaire combinant observations du satellite GOES et données in situ. Nous proposons une fonction d'observation originale basée sur une distribution de probabilité conjointe des deux types de données. Les résultats statistiques sont conformes à ceux des méthodes existantes. Le biais journalier varie de -16 W / m² (-7% de la moyenne des mesures) à 12 W / m² (6%). L'erreur quadratique moyenne (RMSD) est comprise entre 23 W / m² (10%) et 27 W / m² (15%). Le coefficient de corrélation est de 0,92. La méthode est peu sensible aux variations climatiques saisonnières, le biais et RMSD restent similaires en saison des pluies comme en saison sèche, mais une meilleure corrélation est observée pendant la saison des pluies. Les incertitudes sont principalement dues à la présence de conditions atmosphériques tropicales spécifiques en saison sèche. La méthode a été soumise à différents tests : un processus de validation croisée a mis en évidence la possible généralisation du modèle dans une dimension temporelle, la capacité du modèle à reproduire efficacement des anomalies dans les séries temporelles d'irradiance solaire de surface a aussi été testée. La robustesse des résultats obtenus montrent l'intérêt du modèle par rapport aux autres méthodes d'estimation existantes. A cause de sa simplicité de mise en oeuvre cette méthode ouvre de nouvelles perspectives en matière d'estimation de l'irradiance solaire au sol. Nous concluons que l'utilisation d'un filtre particulaire combinée à une fonction d'observation originale permet une estimation de haute qualité de l'irradiance solaire au sol en Guyane Française.
Canadian Journal of Remote Sensing

meteo-01304574
https://hal-meteofrance.archives-ouvertes.fr/meteo-01304574
DOI : 10.1080/07038992.2015.1040150

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : The term social entrepreneurship is not new but during the past decade its interests have increased rapidly around the world while its field is still young and fragmented (Gawell, 2013). We believe that in one way or the other, the main objective of social entrepreneurship is to solve social, economic and environmental problems for sustainable development goals. One of the development challenges is the fact that Haiti has 0.47 as Human Development Index (HDI) figuring 168th among 187 countries with 58.6 % of the population living under the poverty line and 24.6% under the extreme poverty line with less than 1$UD per day (PNUD & MCI, 2014). Despite the fact that Haiti has a unique know-how that is passed down for generations in the area of craft, small industry and in the processing of products, social entrepreneurship has not taken its roots as it should have. Importantly, to get where they are today, it is undeniable that developed nations leaned the strengths of their development on human capital to produce physical/material capital. Most often, the human capital is utilized to produce strong public policies which enable the economic growth. The value of using human capital as a pillar for economic growth proved itself for Asian nations with an annual economic growth of 6.9% between 1980 and 1990 against 1.5% for Latin America (Gener, 2005). Thus, in this paper, we looked at the Emergence of Social Entrepreneurship for economic growth in Haiti.
 L'entrepreneuriat social n'est pas nouveau, mais au cours de la dernière décennie, l’intérêt pour ce terme a rapidement augmenté dans le monde alors que son champ est encore jeune et fragmenté (Gawell, 2013). Nous pensons que d'une manière ou d'une autre, l'objectif principal de l'entrepreneuriat social est de résoudre les problèmes sociaux, économiques et environnementaux en vue d'atteindre les objectifs de développement durable. La mission ou les activités d'une organisation sont soit entièrement philanthropiques soit uniquement commerciales. L'un des défis du développement est le fait que l’indice de développement humain (IDH) d’Haïti est de 0,47, le pays figure au 168e (parmi 187 pays). 58,6% de la population vit sous le seuil de pauvreté et 24,6% sous le seuil de pauvreté extrême avec moins de 1 USD par jour (PNUD et MCI, 2014). Malgré le fait qu’Haïti possède un savoir-faire unique transmis depuis des générations dans le domaine de l'artisanat, de la petite industrie et de la transformation des produits, l'entrepreneuriat social n'a pas pris ses racines comme il se doit. Il est important de noter que pour arriver là où ils sont aujourd'hui, il est indéniable que les pays développés ont soutenu le développement du capital humain pour produire du capital physique / matériel. Le plus souvent, le capital humain est utilisé pour produire des politiques publiques solides qui permettent la croissance économique. La valeur de l'utilisation du capital humain comme pilier de la croissance économique a été prouvée pour les pays asiatiques avec une croissance économique annuelle de 6,9% entre 1980 et 1990 contre 1,5% pour l'Amérique latine (Gener, 2005). Ainsi, dans cet article, nous examinons l'émergence de l'entrepreneuriat social pour la croissance économique en Haïti.
Haïti

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.10406
http://journals.openedition.org/etudescaribeennes/10406

Résumé : L’ingénierie agroécologique vise à produire des savoirs actionnables, pour concevoir des systèmes de cultures économiquement et écologiquement performants, par la valorisation de régulations naturelles. Notre problématique est centrée sur la santé des cultures, et plus particulièrement sur la bactérie phytopathogène Ralstonia solanacearum, agent du flétrissement bactérien alors qu’une souche extrêmement agressive menace la production de tomates en plein champ en Martinique. La nécessité d’explorer et de développer des alternatives aux méthodes conventionnelles de protection des plantes (variétés résistantes, pesticides), actuellement inefficaces, invite à la mise en œuvre d’une démarche de conception innovante. Nos travaux montrent que la mobilisation d’une barrière rhizosphérique est une stratégie de régulation biologique alternative. Différents processus y contribuent, telle que la mycorhization, symbiose entre racines et champignons mycorhiziens à arbuscules, présents dans la plupart des sols. Nous montrons que la mobilisation de réseaux de mycorhizes indigènes à partir d’un sol agricole permet une mycorhization précoce de la tomate. De plus, l’association de plantes aux propriétés mycorhizotrophes et assainissantes en conditions contrôlées montre des effets bioprotecteurs partiels et ouvre de nouvelles perspectives de combinaisons entre processus. Ces combinaisons sont mobilisables par des leviers d’actions multi-scalaires. Nous avons produit une grille d’analyse générique de ces leviers d’action pour la conception, par des trajectoires d’innovation multidirectionnelles, de « systèmes de culture bioprotégés ». Dans le contexte agricole martiniquais, une démarche d’apprentissage permet en effet l’émergence d’une dynamique de co-conception de systèmes de cultures recourant aux plantes mycorhizotrophes. Nos travaux proposent des outils pour une exploration collective de nouvelles stratégies de gestion durable de la santé des cultures.
Agroecological engineering aims to produce actionable knowledge to design economically and environmentally efficient cropping systems, based on the exploitation of natural regulation mechanisms. Our issue is centered on crop health, especially on the plant pathogenic bacterium Ralstonia solanacearum (bacterial wilt agent), of which an extremely aggressive strain threatens field tomato production in Martinique. The need to explore and develop alternatives to conventional methods of plant protection (resistant varieties, pesticides), ineffective in our case, calls for the implementation of an innovative design approach. Our work shows that the protection of the roots via the formation of a self-sustaining rhizospheric barrier may be an alternative biological control strategy. Different processes contribute, such as mycorrhizal symbiosis between roots and arbuscular mycorrhizal fungi, which are present in most soils. We show that the mobilization of indigenous mycorrhizal networks from an agricultural soil allows early mycorrhization of tomatoes. In addition, the association of plants with mycorrhizal and sanitizing properties in controlled conditions showed partial bioprotective effects and opens up new prospects for combinations between processes. These combinations may be exploited in various ways. We produced a generic analysis grid of key levers to design "healthy cropping systems " through multi-directional innovation trajectories. In Martinique's agricultural context, a learning process allows the emergence of a dynamic co-design of cropping systems using mycorrhizal plants. Our work thus provides tools for collective exploration of new sustainable management strategies for crop health.

http://www.theses.fr/2015AGUY0828/document

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The deep structure and deformation mechanisms of the Longmen Shan thrust belt (Sichuan, China), at the eastern border of the Tibetan plateau, were largely debated after the devastating Mw 7.9 Wenchuan earthquake (2008). Recent geophysical studies and field investigations have been focused on the active motion of the major Beichuan fault, which ruptured during the earthquake. However, the total exhumation across the fault still remains unclear. In the hanging wall of the Beichuan fault, the South China block is exhumed in the Pengguan massif. Close to the Beichuan fault, the rocks of the Pengguan massif underwent greenschist facies metamorphism associated with brittle-ductile deformation. No metamorphism is observed in the footwall of the fault. In this study, we characterize and date the metamorphic history recorded in the hanging wall of the Beichuan fault in order to constrain the depth and timing of exhumation of the rocks of the Pengguan massif along the fault. A high-resolution petrological approach involving chemical analyses and X-ray maps was used to analyze the micrometric metamorphic minerals. The P-T conditions of the greenschist facies metamorphic event were estimated by an inverse multi-equilibrium thermodynamic approach. The results, 280 ± 30 °C and 7 ± 1 kbar, suggest that the rocks of the Pengguan massif were exhumed from ca. 20 km depth. Our results underline the importance of the thrusting component in the long-term behavior of the Beichuan fault and provide a minimal depth at which the fault is rooted. In situ laser ablation 40Ar/39Ar dating of metamorphic white mica revealed that the greenschist overprint occurred at 135–140 Ma.The Pengguan massif was therefore partially thrusted along the Beichuan fault during the Lower Cretaceous, long before the Eocene-Miocene exhumation phase which is well-constrained by low-temperature thermochronology. Our results provide the first independent depth information for the exhumation history of the Pengguan massif and reveal a previously undocumented Lower Cretaceous tectonic event that marks the onset of the thick-skinned deformation in the external domain of the Longmen Shan (East of the Wenchuan Fault).
ISSN: 0743-9547

hal-01685556
https://hal.archives-ouvertes.fr/hal-01685556
DOI : 10.1016/j.jseaes.2017.04.003

Éditeur(s) : HAL CCSD Wiley
Résumé :  
The symbiotic interactions between Frankia strains and their associated plants from the Casuarinaceae under controlled conditions are well documented but little is known about these interactions under natural conditions. We explored the symbiotic interactions between eight genotypically characterized Frankia strains and five Casuarinaceae species in long-term field trials. Characterization of strains was performed using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) for the nifD-nifK intergenic transcribed spacer (ITS) and 16S-23S ITS. Assessments of the symbiotic interactions were based on nodulation patterns using nodule dry weight and viability, and on actual N-2 fixation using the delta N-15 method. The PCR-RFLP patterns showed that the analyzed strains belonged to the same genotypic group (CeD group), regardless of the host species and environment of origin. The nodule viability index is introduced as a new tool to measure the viability of perennial nodules and to predict their effectiveness. The host Casuarinaceae species was a key factor influencing both the actual N-2-fixing activity of the associated Frankia strain and the viability of nodules within a location. This is the first study providing information on the symbiotic interactions between genotypically characterized Frankia strains and actinorhizal plants under natural conditions. The results revealed a way to improve a long-term management of the Casuarinaceae symbiosis.
ISSN: 0031-9317

hal-01032134
https://hal.archives-ouvertes.fr/hal-01032134
DOI : 10.1111/j.1399-3054.2007.00856.x

Éditeur(s) : HAL CCSD
Résumé : This study provides additional constraints on the relations between deformation, hydration and percolation of fluids and melts in the subcontinental lithospheric mantle beneath a craton and a rift, as well as their implication on its geodynamical behaviour. I have analysed the microstructures, the CPOs, and the hydrogen content of mantle xenoliths from the Kaapvaal craton, and two sets of xenoliths from different localities along the East African Rift (North Tanzanian Divergence and SE Ethiopia).The coarse-granular microstructures and the well-defined CPOs in Kaapvaal peridotites suggest a deformation followed by a long quiescence time. Orthorhombic olivine CPOs predominates, but axial-[100] and axial-[010] are also measured. Cratonic peridotites record multiple metasomatic episodes, leading to a significant compositional heterogeneity, which cannot be imaged by seismic studies. Olivine hydrogen contents are variable, but tend to increase until 150 km depth, reaching up to 50 ppm wt. H2O. The deeper samples are almost dry. Piston-cylinder experiments on hydrogen diffusion between a volatile-rich kimberlitic melt and forsterite suggest that the presence of CO2 in the system could significantly decrease water fugacity and thus forsterite hydration. These experimental results indicate that the hydrogen contents measured in olivine were acquired during a metasomatic event rather than during xenolith extraction by kimberlites. However, this metasomatism was not followed by remobilization of the cratonic root.In the North Tanzanian Divergence, localities within the rift axis and the volcanic transverse belt (Lashaine and Olmani) show significant differences in microstructures and olivine CPO patterns. In Lashaine, coarse-granular microstructures and orthorhombic to axial-[100] CPO patterns in olivine can be explained by transpressional deformation during the formation of the Mozambique belt, or by the occurrence of a remnant of a cratonic domain embedded within the Mozambique belt. Within the rift axis, porphyroclastic to mylonitic microstructures suggest a recent rift-related deformation accompanied by syn-kinematic melt-rock reactions, and followed by variable annealing. The strong heterogeneity in microstructures and olivine CPO suggests that this deformation was acquired during multiple tectonic events probably linked to episodic magma percolation, separated by quiescence episodes. The axial-[100] patterns in olivine and the oblique fast directions reported by SKS studies are coherent with transtensional deformation within the lithospheric mantle beneath the rift.The peridotites from SE Ethiopia are less recrystallized than the rift-axis Tanzanian peridotites, displaying coarse-porphyroclastic microstructures. Microstructures and orthorhombic CPOs in olivine suggest syn- to post-metasomatic deformation. S-waves polarization anisotropies calculated for these samples cannot explain alone the delay times reported by SKS studies in this part of the East-African Rift.
Les travaux réalisés durant cette thèse apportent de nouvelles contraintes sur les relations entre déformation, hydratation et percolation de fluides et/ou de magmas dans le manteau subcontinental sous un craton et sous un rift, et leurs implications sur son comportement rhéologique. Il repose sur l'analyse des microstructures, des OPRs et des teneurs en hydrogène de xénolites mantelliques du craton du Kaapvaal, et sur deux séries de xénolites provenant de différentes localités le long du rift Est-Africain (Divergence Nord Tanzanienne et SE de l'Ethiopie). Les microstructures granulaires à gros grains et les OPRs bien définies des péridotites du craton du Kaapvaal sont cohérentes avec un épisode de déformation suivi d'une longue période de quiescence. Les OPRs de l'olivine sont majoritairement à symétrie orthorhombique, mais des symétries axiale-[100] et axiale-[010] sont aussi mesurées. Les péridotites cratoniques enregistrent de multiples épisodes métasomatiques, ayant entraîné une hétérogénéité de compositions à petite échelle ne pouvant être détectée par les études sismiques. Les teneurs en hydrogène mesurées dans l'olivine sont variables, mais ont tendance à augmenter jusqu'à 150 km de profondeur, atteignant alors jusqu'à 50 ppm wt. H2O. En dessous de cette profondeur, les échantillons montrent des teneurs en hydrogène très faibles. Les expériences réalisées en piston-cylindre sur la diffusion de l'hydrogène issue d'un liquide kimberlitique vers de la forstérite suggèrent que la fugacité en eau pourrait fortement être diminuée par la présence de CO2, empêchant l'hydratation de l'olivine durant extraction des xénolites par les kimberlites. Ces résultats expérimentaux suggèrent que les teneurs en hydrogène dans l'olivine des péridotites du craton du Kaapvaal ont été acquises durant un épisode métasomatique en profondeur et non pendant leur extraction par les kimberlites. Ces teneurs n'ont toutefois pas à ce jour entraîné de remobilisation de la racine cratonique. Enfin, le calcul des propriétés sismiques des péridotites cratoniques révèle que les anisotropies générées par les OPRs de ces échantillons sont suffisantes pour expliquer les anisotropies mesurées par les ondes SKS et les ondes de surface.Les xénolites de la Divergence Nord-Tanzanienne, montrent des variations significatives de microstructures et d'OPR de l'olivine entre les péridotites des localités dans l'axe du rift et celles de la chaîne volcanique transverse (Lashaine et Olmani). A Lashaine, les microstructures granulaires à gros grains et les OPRs de type orthorhombique et axial-[010] peuvent être expliquée par une déformation en transpression liée à la formation de la chaîne Mozambique ou par la présence d'une relique d'un domaine cratonique à l'intérieur de la chaîne Mozambique. Dans l'axe du rift, les microstructures porphyroclastiques à mylonitiques suggèrent une déformation plus récente, accompagnée de réactions magma-roche sous des conditions proches du solidus, suivie d'un recuit variable. L'hétérogénéité des microstructures enregistrées par les échantillons du rift suggère de multiples épisodes de déformation localisée, probablement liés à l'injection percolation épisodique de magmas, espacés de périodes d'accalmie. Les OPRs de l'olivine de type axial-[100] et l'orientation des directions de polarisation des ondes SKS suggère que le rift s'est formé en régime de transtension Les péridotites du Sud-Est de l’Éthiopie présentent des microstructures porphyroclastiques à gros grains moins recristallisées qu'en Tanzanie. Les microstructures et les OPRs principalement de type orthorhombique suggèrent une déformation syn- à post-métasomatisme. Les anisotropies de polarisation des ondes S calculées pour ces échantillons sont insuffisantes pour expliquer à elles seules les déphasages des ondes SKS dans cette partie du rift.
https://tel.archives-ouvertes.fr/tel-01684759

Droits : info:eu-repo/semantics/OpenAccess
NNT : 2014MON20139
tel-01684759
https://tel.archives-ouvertes.fr/tel-01684759
https://tel.archives-ouvertes.fr/tel-01684759/document
https://tel.archives-ouvertes.fr/tel-01684759/file/43443_BAPTISTE_2014_archivage_cor.pdf

Résumé : Planta perenne con raíces gruesas. Culmos cilíndricos gruesos, de hasta 1 m de alto, huecos, septados. Espiguillas cilíndricas, de hasta 5 cm, con muchas flores; glumas subcartilaginosas, nervadas, obovadas u oblongas con márgenes escariosos; estambres 3, estilo 2 a 3 dividido. Aquenios biconvexos, amarillos, pardos o grises.
Plante pérenne avec de grosses racines. Extrémités cylindriques épaisses, pouvant atteindre 1 m de haut, creuses, présentant sept éléments. Petits épis cylindriques, pouvant atteindre 5 cm, avec de nombreuses fleurs; glumes subcartilagineuses, avec nervures, ovées ou oblongues à bords scarieux; étamines 3, style 2 à 3 divisé. Akènes biconvexes, jaunes, bruns ou gris.
Perennial, stoloniferous plant, with fibrous roots.  Culms tufted 40-100 cm tall 3.6 mm thick, cylindrical, hollow, transversely septate; spikelets cylindrical, up to 6 cm long x 5-7 mm wide; glumes straw-coloured, oblong to obovate 4-5 mm x 3 mm; stamens 3, style 3-fid.  Achenes oval to obovate 1.5-2 mm long, biconvex, slightly shiny, brownish-yellow.
Pantropical, común en terrenos húmedos.
Pantropicale, commune en terrains humides.
Pantropical, growing in swampy areas.

http://www.tramil.net/fototeca/plant163

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Satellite precipitation products are a means of estimating rainfall, particularly in areas that are sparsely equipped with rain gauges. The Guiana Shield is a region vulnerable to high water episodes. Flood risk is enhanced by the concentration of population living along the main rivers. A good understanding of the regional hydro-climatic regime, as well as an accurate estimation of precipitation is therefore of great importance. Unfortunately, there are very few rain gauges available in the region. The objective of the study is then to compare satellite rainfall estimation products in order to complement the information available in situ and to perform a regional analysis of four operational precipitation estimates, by partitioning the whole area under study into a homogeneous hydro-climatic region. In this study, four satellite products have been tested, TRMM TMPA (Tropical Rainfall Measuring Mission Multisatellite Precipitation Analysis) V7 (Version 7) and RT (real time), CMORPH (Climate Prediction Center (CPC) MORPHing technique) and PERSIANN (Precipitation Estimation from Remotely-Sensed Information using Artificial Neural Network), for daily rain gauge data. Product performance is evaluated at daily and monthly scales based on various intensities and hydro-climatic regimes from 1 January 2001 to 30 December 2012 and using quantitative statistical criteria (coefficient correlation, bias, relative bias and root mean square error) and quantitative error metrics (probability of detection for rainy days and for no-rain days and the false alarm ratio). Over the entire study period, all products underestimate precipitation. The results obtained in terms of the hydro-climate show that for areas with intense convective precipitation, TMPA V7 shows a better performance than other products, especially in the estimation of extreme precipitation events. In regions along the Amazon, the use of PERSIANN is better. Finally, in the driest areas, TMPA V7 and PERSIANN show the same performance.
ISSN: 2072-4292

Droits : http://hal.archives-ouvertes.fr/licences/copyright/
hal-01257912
https://hal.archives-ouvertes.fr/hal-01257912
https://hal.archives-ouvertes.fr/hal-01257912/document
https://hal.archives-ouvertes.fr/hal-01257912/file/remotesensing-07-15831.pdf
DOI : 10.3390/rs71215831

Éditeur(s) : HAL CCSD INRA Editions
Résumé : International audience
The objective of this study was to examine the water relations and hydraulic architecture and vulnerability to cavitation in Virola surinamensis and V. michelii and to compare to similar measurements in Eperua falcata. In several previous reports Virola was seen to have a rather narrow range of xylem pressure potentials (Ψx) near zero in the course of a wet-season day while having water fluxes quite close to Eperua. We tested the hypothesis that the narrow range of Ψx might be consistent with very high hydraulic conductivities of stems, roots and shoots and high vulnerability to cavitation in Virola compared to Eperua. When this hypothesis proved false we concluded that the previous determinations of Ψx might be wrong in Virola due to latex. We re-examined the determination of Ψx in Virola by the pressure chamber technique and compared results to determination of Ψleaf by the thermocouple psychrometer technique and found that the likely range of Ψx are more negative than previously reported. Problems concerning the determination of Ψx in species with latex are discussed.
ISSN: 2268-4565

hal-01077475
https://hal.archives-ouvertes.fr/hal-01077475
https://hal.archives-ouvertes.fr/hal-01077475/document
https://hal.archives-ouvertes.fr/hal-01077475/file/JPH-1-e0002.pdf

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Persistent organic pollutants have not been conclusively associated with length of gestation or with preterm birth. Chlordecone is an organochlorine pesticide that has been extensively used to control the banana root borer population in the French West Indies. Data from the Timoun Mother-Child Cohort Study conducted in Guadeloupe between 2004 and 2007 were used to examine the associations of chlordecone concentrations in maternal plasma with the length of gestation and the rate preterm birth in 818 pregnant women. Data were analyzed using multivariate linear regression for length of gestation and a Cox model for preterm birth. The median plasma chlordecone concentration was 0.39 µg/L (interquartile range, 0.18-0.83). No correlation was observed with plasma concentrations of p,p'-dichlorodiphenyl dichloroethene (ρ = 0.017) or polychlorinated biphenyl 153 (ρ = -0.016), the other main organochlorine compounds detected. A 1-log10 increase in chlordecone concentration was associated with a decreased length of gestation (-0.27 weeks; 95% confidence interval: -0.50, -0.03) and an increased risk of preterm birth (60%; 95% confidence interval: 10, 130). These associations may result from the estrogen-like and progestin-like properties of chlordecone. These results are of public health relevance because of the prolonged persistence of chlordecone in the environment and the high background rate of preterm births in this population.
ISSN: 0002-9262

hal-01010740
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01010740
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01010740/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01010740/file/Chlordecone%20Exposure%20final.pdf
DOI : 10.1093/aje/kwt313

Résumé : Herbácea erecta o trepadora de hasta 1 m de alto, estolonífera y con tubérculos. Hojas imparipinnadas; folíolos ovados o elípticos, ápice agudo o acuminado, base obtusa. Panículas terminales con muchas flores; cáliz lobado hasta cerca de la mitad de su longitud, lóbulos lanceolados, acuminados; corola blanca, azul, rosada o purpúrea, levemente lobada. Baya (fruto) subglobosa, glabra, amarilla.
Herbacée dressée ou grimpante pouvant atteindre 1 m de haut; stolonifère à tubercules. Feuilles imparipennées; folioles ovés ou elliptiques, extrémité aiguë ou acuminée, base obtuse. Panicules terminales portant de nombreuses fleurs; calice lobé ayant approximativement la moitié de sa longueur, lobes lancéolés, acuminés; corolle blanche, bleue, rosée ou pourpre, légèrement lobée. Baie (fruit) subarrondie, glabre, jaune.
Herbaceous branched annual 0.3-1m high, with a mass of fine fiberous adventitious roots and swollen stem tubers.  Leaves pinnate with small interjected leaflets between the main pinnae; flowers white, red or purple; fruit a small inedible berry.
Oriunda del sur de América, ampliamente cultivada en todo el mundo.
Originaire du sud de l’;Amérique, cultivée dans le monde entier.
Native to South America, now widely cultivated worldwide.

http://www.tramil.net/fototeca/plant329

Éditeur(s) : HAL CCSD Elsevier
Résumé : Displacement-length data from faults, joints, veins, igneous dikes, shear deformation bands, and compaction bands define two groups. The first group, having a power-law scaling relation with a slope of n = 1 and therefore a linear dependence of maximum displacement and discontinuity length (D-max = gamma L), comprises faults and shear (non-compactional or non-dilational) deformation bands. These shearing-mode structures, having shearing strains that predominate over volumetric strains across them, grow under conditions of constant driving stress, with the magnitude of near-tip stress on the same order as the rock's yield strength in shear. The second group, having a power-law scaling relation with a slope of n = 0.5 and therefore a dependence of maximum displacement on the square root of discontinuity length (D-max = alpha L-0.5), comprises joints, veins, igneous dikes, cataclastic deformation bands, and compaction bands. These opening- and closing-mode structures grow under conditions of constant fracture toughness, implying significant amplification of near-tip stress within a zone of small-scale yielding at the discontinuity tip. Volumetric changes accommodated by grain fragmentation, and thus control of propagation by the rock's fracture toughness, are associated with scaling of predominantly dilational and compactional structures with an exponent of n = 0.5.
ISSN: 0191-8141

hal-00411173
https://hal.archives-ouvertes.fr/hal-00411173
DOI : 10.1016/j.jsg.2008.08.001

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In ophiolites and in present-day oceanic crust formed at fast spreading ridges, oceanic plagiogranites are commonly observed at, or close to the base of the sheeted dike complex. They can be produced either by differentiation of mafic melts, or by hydrous partial melting of the hydrothermally altered sheeted dikes. In addition, the hydrothermally altered base of the sheeted dike complex, which is often infiltrated by plagiogranitic veins, is usually recrystallized into granoblastic dikes that are commonly interpreted as a result of prograde granulitic metamorphism. To test the anatectic origin of oceanic plagiogranites, we performed melting experiments on a natural hydrothermally altered dike, under conditions that match those prevailing at the base of the sheeted dike complex. All generated melts are water saturated, transitional between tholeiitic and calc-alkaline, and match the compositions of oceanic plagiogranites observed close to the base of the sheeted dike complex. Newly crystallized clinopyroxene and plagioclase have compositions that are characteristic of the same minerals in granoblastic dikes. Published silicic melt compositions obtained in classical MORB fractionation experiments also broadly match the compositions of oceanic plagiogranites; however, the compositions of the coexisting experimental minerals significantly deviate from those of the granoblastic dikes. Our results demonstrate that hydrous partial melting is a likely common process in the root zone of the sheeted dike complex, starting at temperatures exceeding 850A degrees C. The newly formed melt can either crystallize to form oceanic plagiogranites or may be recycled within the melt lens resulting in hybridized and contaminated MORB melts. It represents the main MORB crustal contamination process. The residue after the partial melting event is represented by the granoblastic dikes. Our results support a model with a dynamic melt lens that has the potential to trigger hydrous partial melting reactions in the previously hydrothermally altered sheeted dikes. A new thermometer using the Al content of clinopyroxene is also elaborated.
ISSN: 0010-7999

hal-00534058
https://hal.archives-ouvertes.fr/hal-00534058
DOI : 10.1007/s00410-010-0502-6

Résumé : Herbácea bienal. Raíz típicamente globosa o elongada, de color exterior blanco, blanco con púrpura o amarillento. Casi sin tallo antes de florecer. Hojas de hasta 30 cm de largo, glaucas, a veces liradas. Tallo de inflorescencia con hojas lobuladas. Flores con 4 pétalos amarillos, dispuestas en racimos corimbosos.
Herbacée bisannuelle. Racine typiquement renflée ou allongée, extérieurement de couleur blanche, blanc mêlé de pourpre ou jaunâtre. Presque dépourvue de tige avant la floraison. Feuilles pouvant atteindre 30 cm de long, glauques, parfois en forme de lyre. Tige à inflorescence avec feuilles lobulées. Fleurs à 4 pétales jaunes, disposées en grappes ombelliformes.
Biennial herb, almost without stem before flowering.  Leaves pinnatifid, up to 60 cm long, with terminal lobe larger and rounded and the lower lobes smaller; inflorescence a raceme, flowers with four yellow petals; fruit dry, dehiscent; roots globose or elongated, skin white, white and purple, green or yellowish, the flesh white or yellow.
Originaria de Eurasia. Ampliamente cultivada en regiones templadas.
Originaire d';Eurasie. Largement cultivée dans les régions tempérées.
Native to Eurasia.  Widely cultivated in regions with moderate climate.

http://www.tramil.net/fototeca/plant107

Éditeur(s) : HAL CCSD Seoul National University
Résumé : http://www.episodes.org/backissues/302/abstract2.htm
International audience
The Trans-North China Belt (TNCB) is a Paleoproterozoic collisional orogen (ca. 1.9-1.8 Ga) responsible for the amalgamation of the North China Craton. Detail field works in Lüliangshan, Hengshan, Wutaishan and Fuping massifs where the belt is well exposed, allow us to draw new tectonic map and crustal-scale cross sections. The available petrologic, radiometric, geochronologic data are integrated in a geodynamic evolution scheme for this orogen. The Low Grade Mafic Unit (LGMU) is interpreted as an ophiolitic nappe rooted in a suture zone located in the western part of the Lüliangshan. This ophiolitic nappe overthrusts to the SE upon the Orthogneiss-Volcanites Unit (OVU) that consists of a bimodal volcanicsedimentary series metamorphosed under amphibolite facies conditions intruded by calcalkaline orthogneiss. The OVU is a composite Neoarchean-Paleoproterozoic magmatic arc developed during two stages (ca. 2500 and 2100 Ma) upon a continental basement corresponding to the western extension of the Neoarchean Fuping massif. The OVU overthrusts to the SE the Fuping massif along the Longquanguan shear zone. This stack of nappe, coeval with an amphibolite facies metamorphism, is dated at ca 1880 Ma. Subsequently, the metamorphic series experienced a widespread migmatization at 1850 Ma and was intruded by post-orogenic plutons dated at 1800 Ma. The weakly to unmetamorphosed Hutuo Supergroup unconformably overlies the metamorphosed and ductilely deformed units (OVU and LGMU), but it is also involved in a second tectonic phase developed in subsurface conditions. These structural features lead us to question the ca 2090 Ma age attributed to the Hutuo supergroup. Moreover, in the Fuping massif, several structural and magmatic lines of evidence argue for an earlier orogenic event at ca 2100 Ma that we relate to an older west-directed subduction below the Fuping Block. The Taihangshan Fault might be the location of a possible suture zone between the Fuping Block and an eastern one. A geodynamic model, at variance with previous ones, is proposed to account for the formation of the TNCB. In this scheme, three Archean continents, namely from West to East, the Ordos, Fuping and Eastern Blocks are separated by the Lüliang and Taihang Oceans. The closure of the Taihang Ocean at ca 2100 Ma by westward subduction below the Fuping Block accounts for the arc magmatism and the 2100 Ma orogeny. The second collision at 1900-1880 Ma between the Fuping and Ordos blocks is responsible for the main structural, metamorphic and magmatic features of the Trans-North China Belt.
ISSN: 0705-3797

insu-00152972
https://hal-insu.archives-ouvertes.fr/insu-00152972
https://hal-insu.archives-ouvertes.fr/insu-00152972/document
https://hal-insu.archives-ouvertes.fr/insu-00152972/file/Episodes_TNCB_Faure_et_al.pdf