Politique Trame verte et bleue : quelle cohérence territoriale ?

International audienceThe French public policy “Trame verte et bleue” (TVB) aims at preserving and restoring ecological networks. It is implemented at different scales, from national to regional and to local. The TVB coherence between spatial and governance scales is established in the French law. But territories have a wide margin for interpretation and implementation of this policy, which is paradoxically both a source of coherence and incoherence. A balance has to be found between different territory functions and between territories, implying compromises between stakeholders who have a variety of interests. We provide a territorial coherence evaluation grid of these “social-ecological” systems. After a definition of this form of territorial coherence, we shall present and discuss the evaluation grid with its criteria, together with our preliminary results on case study areas in Bretagne and Languedoc-Roussillon (two French regions).La Trame verte et bleue (TVB) vise la préservation et la remise en bon état des continuités écologiques. Cette politique publique est multi-échelles et se décline du national au régional au local. La cohérence de la TVB entre les échelles spatiales et de gouvernance est cadrée dans la loi française. Mais une importante marge d’appréciation de la politique est laissée aux territoires, ce qui est paradoxalement à la fois source de cohérence et d’incohérence. Un équilibre est à trouver entre les différentes fonctions du territoire et entre les territoires, impliquant des compromis entre acteurs aux intérêts distincts. Nous proposons une grille d’analyse de la cohérence territoriale de ces systèmes « socio-écologiques », au coeur des projets de réseaux écologiques. Après avoir défini les contours de cette forme de cohérence territoriale multi-dimensionnelle, nous présenterons et discuterons de la grille d’analyse assortie des critères identifiés, ainsi que de nos premiers résultats sur nos territoires d’étude en Bretagne et en Languedoc-Roussillon

Mechanisms of formation and reactivity of imogolite types material

Reactivity of nanopar8cles represents a central issue for many laboratories around the world. Among many supported efforts the control of the morphology of nanopar8cles is mo8vated by the fact that morphology strongly influence the proper8es of the final products. Among the vast family of available nanopar8cles, imogolite is a clay nanotube for which perfect control of the diameter is possible. Imogolites were first observed in volcanic soils[1]. They are natural aluminosilicate nanotubes having the general formula (OH)3Al2O3SiOH with a 2 nm external diameter and up to micrometers in length. The impressive monodispersity in imogolite nanotube diameter has mo8vated research on their forma8on mechanism. Synthesis protocols to produce imogolite were quickly developed. Farmer et al. were the first to obtain synthe8c imogolite using low concentra8ons of AlCl3 and SiO 2 monomers as star8ng materials (millimolar concentra8ons of the reagents) [2]. However, the produc8on of large amount of imogolite or imogolite type materials remained challenging for long 8me. We will present our most recent results concerning the possibility to produce imogolite type materials from highly concentrated stock solu8ons. We will also detail the possibility to form double wall Al- Ge nanotubes and the different stages of their forma8on [3-7]. We will then detail the surface reac8vity of these nanotubes toward metals at he lab scale as well as in natural soil. (Résumé d'auteur

Copper and zinc speciation in pig slurry: implications on mobility and bioavailability in soils

The fate of pollutants associated with organic wastes is a key issue. For example, pig slurry presents high concentration of Copper (Cu) and Zinc (Zn) since they are used (at high concentration) as essential micronutrients in animal feeds. As a consequence, Cu and Zn accumulation was measured in soil surface layers that had been amended with pig slurry, inducing phytotoxicity as well as groundwater quality degradation. Better prediction of the mobility and bioavailability of Cu and Zn from pig slurry spreading can be achieved by determining the speciation of these elements. The aim of this study is to investigate Cu and Zn speciation in pig slurry. A multitechnique approach was adopted including size fractionation, XRD, SEM-EDS, ?XRF and XAS. The present study demonstrated that only 0.2% of total Cu or Zn present in pig slurry was bound to particles smaller than 0.45 ?m, while 75% of total Cu and Zn was bound to particles in the 0.45-20 ?m size range. ?XRF highlighted the colocalisation of Cu and sulfur. In addition, geochemical modelling demonstrated that physical chemical conditions within pig slurry lagoon are compatible with the precipitation of chalcocite (Cu2S). Finally, XANES shows that Cu speciation in raw pig slurry and size fractions is described by Cu2S and that its oxidation state is Cu(I). These Cu speciation in pig slurry may be the main reason for the observed Cu accumulation at the soil surface. Zn speciation revealed three patterns 49% Zn bound to organic matter, 37% amorphous Zn hydroxide, and 14% sphalerite (ZnS). The detected presence Zn sulphide, was unexpected and is reported for the first time. These three Zn forms seemed to be soluble in neutral or weakly acid soil systems, so the long-term impact of pig slurry spreading could lead to Zn leaching. (Résumé d'auteur

Méthode d'élaboration d'un dispositif de suivi et d'évaluation de la politique Trame verte et bleue : application aux Schémas régionaux de cohérence écologique

Toute politique publique nécessite une évaluation. En ce qui concerne la Trame verte et bleue (TVB), un groupe de travail initié par le ministère en charge de l'environnement a produit en amont de la rédaction des Schémas régionaux de cohérence écologique (SRCE), des propositions pour concevoir cette évaluation. Ces propositions ont permis de mettre à disposition des acteurs territoriaux un ensemble de questions évaluatives et d'indicateurs, centrés sur les objectifs communs des SRCE, et des règles d'organisation du dispositif. Au-delà de la présentation du cadre méthodologique retenu, les auteurs de cet article s'interrogent sur les perspectives d'amélioration et d'appropriation du dispositif dans un contexte de forte évolution législative de la TVB

Historia de pérdidas y sintomatología depresiva.

En la literatura científica se ha dado importancia a la relación existente entre las pérdidas, la muerte de un ser querido y la depresión. Objetivos. Identificar la prevalencia de las pérdidas de seres queridos y otros tipos de pérdidas, la percepción de los participantes de haberse adaptado satisfactoriamente o no a cada una de las pérdidas y la relación que dichas pérdidas y su posible superación tienen con la sintomatología depresiva. Método. Utilizando el Inventario de Historia de Pérdidas (IHP) y el BDI-II se evaluó una muestra comunitaria incidental de 288 participantes. Resultados. El 42,71% de la muestra mencionó alguna pérdida que consideraba no haber superado. Se encontró que la intensidad de los síntomas correlacionaba con el número total de pérdidas, con el número de pérdidas de ser querido no superadas y con las pérdidas no superadas de otra índole. Conclusiones. Sería conveniente explorar la historia de pérdidas tanto de participantes en estudios de investigación como de los pacientes que se atienden ya desde el primer contacto, dado que las pérdidas pueden ser un factor de predisposición en la presentación de sintomatología diversa, y un aspecto a considerar en la planificación del tratamiento. El IHP es un instrumento breve y adecuado que cumple con ese propósito

Impact of durum wheat milling on the deoxynivalenol distribution in the outcoming fractions

International audienceThe milling behavior of two naturally infected samples from durum wheat grains displaying contrasting levels of mycotoxins were analyzed. Although the two samples showed a similar milling behavior, an increase of about twenty percent in deoxynivalenol level was found in semolina from the sample containing the higher amount of mycotoxins. However, even if the highest concentration of deoxynivalenol was found in fractions originating from the grain outer layers, the mycotoxin contamination in semolina and flours were not related to the amount of two biochemical compounds (ash or phytic acid) that could be used as markers to monitor these external tissues. Presence of the trichothecene-producing fungi in the most internal semolina fraction was also shown using specific DNA primers and PCR amplification. Comparison between deoxynivalenol concentration in the feedings and corresponding output at each milling step or grinding of semolina fractions followed by sizing showed that mycotoxin concentration occurs in the finest particles at the first processing steps. Therefore, deoxynivalenol contamination of the milling fractions is not simply due to the presence of peripheral grain tissues

The High E_T Drop of J/psi to Drell-Yan Ratio from the Statistical c anti-c Coalescence Model

The dependence of the J/psi yield on the transverse energy E_T in heavy ion collisions is considered within the statistical c anti-c coalescence model. The model fits the NA50 data for Pb+Pb collisions at the CERN SPS even in the high-E_T region (E_T > 100 GeV). Here E_T-fluctuations and E_T-losses in the dimuon event sample naturally create the celebrated drop in the J/psi to Drell-Yan ratio.Comment: 14 pages, REVTeX, 1 PS-figure. v2: References are corrected and update

Imogolites as a tool for evaluating the hazard of HARN

Since the discovery of carbon nanotubes (NTs), there has been great interest in the synthesis and characterization of similar shaped structures like inorganic nanotubes, nanorods, or nanowires. Imogolites (Al2SiO3 (OH)4) are natural aluminosilicate single wall nanotubes. To date, only Ge-Al imogolite analogues have been successfully synthesized 100 times more concentrated than Si-Al imogolites. The growth mechanisms of imogolite-like aluminogermanate nanotubes were examined using a combination of local- (XAS at the Ge-Kedge and 27Al NMR) and semilocal scale techniques (in situ SAXS). A model is proposed for the precursors of the nanotubular structure and consist in rooftileshaped particles, up to 5 nm in size, with ca. 26% of Ge vacancies and varying curvatures. These precursors assemble to form short nanotubes/nanorings observed during the aging process. The final products are most likely obtained by an edge-edge assembly of these short nanotube segments. Two structures are revealed by SAXS: at 0.25M of Al the Al-Ge imogolite are double-walled NTs whereas at 0.5 M single-walled NTs are obtained. First tests to reveal cyto and genotoxicity on various vertebrates cells (human fibroblasts and CHO-K1) are interesting. They show a genotoxicity for concentrations from 8 10-5 g/L and effects decreasing from proto-imogolite to long tube. (Texte intégral

Environmental assessment of the behavior of a BOF steel slag used in road construction : the PRECODD-ECLAIR research program

International audienceSteel production generate great amounts of by-products as steel slags. The use of Basic Oxygen Furnace slags (BOF slags) has been restrained due to insufficient volume stability, and due to the lack of environmental regulations. The purpose of the PRECODD-ECLAIR research program is to develop a behavior model based on a multi-scale physico-chemical, mechanical, hydrodynamic and ecotoxicological characterizations of a BOF slag used in a public works scenario. This paper aims at presenting the overall ECLAIR research program, the equipped experimental platform constructed using a BOF steel slag, and the first results of the slag characterization