Accumulation et effets des éléments métalliques sur les populations végétales spontanées de trois crassiers métallurgiques : peut-on utiliser les plantes comme bioindicateurs ?

National audienceThe actual risk of metals doesn't depend on their total concentrations, but rather on their bioavailability and own toxicity, it is important to get suitable tools for evaluating bioavailability and ecological effects of metals in situ. In this context, characterization of bioindicators of soil quality is a challenging issue. In this work, we hypothesized that plants colonizing metal-contaminated soils could be an efficient tool to assess both the bioavailability of metals, and their effect on local ecosystem. To check this hypothesis, we studied spontaneous vegetation colonizing three metallurgical landfills characterised by different total and extractible heavy metals fractions (Table 1), both in terms of metal accumulation in leaves and of phytosociological associations. Results (Tables 2 and 3) showed that for two out of the three studied sites, leaf metals in native plants were closely comparable to normal concentrations found in plants growing in uncontaminated soil, while for the third site average levels in Cr, Cu, Ni, Pb and Zn were significantly higher. Thus, measurements of leaf metals clearly discriminated the studied sites, with respect to actual metal phytoavailability. Botanical survey of the three study sites showed that the vegetation was quite normal, with common species, their associations were unusual and, among the four major plant groups we identified, three of them had never been described. This suggested that metallurgical soils had an effect on the structure of plant communities independently from metal bioavailability. These overall results show that beside soil analyses, plants can provide additional indications regarding both the effects and potential mobility of pollutants.Il est aujourd'hui important de disposer d'outils efficaces pour évaluer la biodisponibilité et les effets écologiques des éléments métalliques des sols pollués. Dans ce contexte, la caractérisation de bioindicateurs de la qualité des sols représente un enjeu important. Pour répondre à cet objectif, nous proposons d'étudier l'accumulation foliaire et les associations végétales de la flore spontanée. Trois sites contaminés ont été étudiés. Sur deux d'entre eux, les concentrations métalliques (Cr, Cu, Ni, Pb et Zn) mesurées dans les plantes sont comparables à celles de la végétation se développant en milieu naturel non contaminé. Pour le troisième, ces concentrations sont significativement supérieures. De plus, ces analyses ont permis de différencier clairement les sites au regard de la phytodisponibilité des métaux. L'étude botanique des sites contaminés indique que si la végétation paraît normale, avec beaucoup d'espèces communes, les quatre associations végétales identifiées sont néanmoins particulières, voire inédites pour trois d'entre elles. Cette observation suggère que le substrat, indépendamment de la mobilité des métaux, a un effet sur la structure des communautés végétales. L'ensemble de ces résultats montre que l'analyse classique de sol, peut être avantageusement complétée par des analyses de la végétation au regard de l'estimation de la biodisponibilité des éléments métalliques et de leurs effets

European Red List of Trees

The European Red List is a review of the status of European species according to IUCN regional Red Listing guidelines. It identifies those species that are threatened with extinction at the regional level – in order that appropriate conservation action can be taken to improve their status. This publication summarises results for all Europe’s native species of tree (454 species), of which 265 species (over 58%) are endemic to continental Europe, with 56% (252 species) endemic to the 28 EU Member States. Of these, 168 (42%) of the species are threatened with extinction at the European level, however, for 57 species (nearly 13%) there was insufficient information to assign a conservation status, and are therefore classified as Data Deficient, and in need of further research. The main threat to tree species in Europe has been identified as invasive or problematic species, impacting 38% of tree species, followed by deforestation and wood harvesting, and urban development (both affecting 20% of tree species). For threatened species, livestock farming, land abandonment, changes in forest and woodland management, and other ecosystem modifications such as fire are the major threats, impacting the survival of trees.Peer reviewe

Metabolic syndrome: definitions and controversies

Metabolic syndrome (MetS) is a complex disorder defined by a cluster of interconnected factors that increase the risk of cardiovascular atherosclerotic diseases and diabetes mellitus type 2. Currently, several different definitions of MetS exist, causing substantial confusion as to whether they identify the same individuals or represent a surrogate of risk factors. Recently, a number of other factors besides those traditionally used to define MetS that are also linked to the syndrome have been identified. In this review, we critically consider existing definitions and evolving information, and conclude that there is still a need to develop uniform criteria to define MetS, so as to enable comparisons between different studies and to better identify patients at risk. As the application of the MetS model has not been fully validated in children and adolescents as yet, and because of its alarmingly increasing prevalence in this population, we suggest that diagnosis, prevention and treatment in this age group should better focus on established risk factors rather than the diagnosis of MetS

Brassica fruticulosa Cyr. (Brassicaceae) adventice dans le département de la Loire

Cornier Bruno. Brassica fruticulosa Cyr. (Brassicaceae) adventice dans le département de la Loire. In: Bulletin mensuel de la Société linnéenne de Lyon, 68ᵉ année, n°9, novembre 1999. pp. 249-250

Sorbus legrei (spec. nov.) et Sorbus remensis (spec. nov.) (Rosaceae), deux nouvelles espèces françaises

Sorbus legrei (spec, nov.) and Sorbus remensis (spec, nov.) (Rosaceae), two new French species The genus Sorbus has been extensively studied in several European countries. Numerous papers about morphological and biological characteristics of the genus have been published, and a number of endemic hybridogenous species have been described. In France, however, hybridogenous populations have only been scarcely studied, despite the presence of a hybridogenous species described since 1779 in the Parisian basin and which is today protected at the national level (Sorbus latifolia, the "service-tree of Fontainebleau"). In the present work, two new French hybridogenous species are described and named. Populations of these species are known since a long time ; the first one is endemic from the Lure Mountain (Alpes-de-Haute-Provence département, formerly Basses-Alpes until 1970) and belongs to the S. hybrida aggregate ; the second one belongs to the S. latifolia aggregate and is endemic from the Marne department, especially in the south of the Reims Mountain. This paper gathers morphological and chorological observations and presents seedling experiments confirming phenotypic stability of the two species. First results of chromosome counting are also given. Moreover, for both taxa historical data are brought about their discovery. Last, guidelines are proposed to aid accurate study of the genus Sorbus in our country.Le genre Sorbus a été très étudié dans un certain nombre de pays d'Europe. D'importants travaux concernant la biologie du genre ont été publiés, et de nombreuses espèces hybridogènes endémiques ont été décrites. En France, les populations hybridogènes ont été relativement peu étudiées, malgré la présence dans le bassin parisien d'une espèce hybridogène décrite depuis 1779, et actuellement protégée au niveau national, l'alisier de Fontainebleau (Sorbus latifolia (Lam.) Pers.). Dans la présente publication, deux espèces hybridogènes nouvelles sont nommées et décrites, pour lesquelles des populations sont connues depuis plusieurs décennies, voire plus d'un siècle ; l'une du groupe de Sorbus hybrida, endémique de la montagne de Lure, dans les Alpes-de-Haute-Provence (département français nommé Basses-Alpes jusqu'en 1970), l'autre du groupe de S. latifolia, endémique de la Marne, présente notamment dans le sud de la montagne de Reims. Cette publication rassemble des observations morphologiques et chorologiques, des résultats d'expériences de semis confirmant la stabilité de ces deux espèces, ainsi que les premiers résultats concernant leur numération chromosomique. Pour chacun de ces taxons, l'histoire de sa découverte est précisée. En conclusion, quelques indications sont données pour favoriser une étude correcte du genre Sorbus dans notre pays.Cornier Bruno. Sorbus legrei (spec. nov.) et Sorbus remensis (spec. nov.) (Rosaceae), deux nouvelles espèces françaises. In: Bulletin mensuel de la Société linnéenne de Lyon, 78ᵉ année, n°1-2, Janvier-février 2009. pp. 27-46

Brassica barrelieri (L.) Janka (Brassicaceae), plante nouvelle pour la France naturalisée dans le département de la Loire

Brassica barrelieri (L.) Janka (Brassicaceae) newly found in France, acclimatized in the Loire department Brassica barrelieri (L.) Janka is a plant originating from Spain and Portugal that has also been mentioned as originating from North Africa. Newly found in the Loire department, it was under so far unknown in France. In this article, we correct the first determination published in 1999 under the name of Brassica fruticulosa Cyr. We also give some descriptive elements to identify B. barrelieri and to avoid confusion with other species. We first indicate the localisations of the stations, the kind of soil it grows on and some information about the climate, then we indicate our information about the morphology and the phenology of the species and we give a floristic inventory. A study of the chromoso mical numeration is also present. Lastly, we try to give the origin of the implantation of B. barrelieri in the Loire department. To conclude, we think that this specie is acclimatized in France, we invite botanists to look for it in siliceous area and we suggest that some comparatives studies might be made in the French Herbariums.Brassica barrelieri (L.) Janka est une plante originaire de la Péninsule Ibérique (Espagne et Portugal) qui fut également signalée en Afrique du Nord. Récemment découverte dans le département de la Loire, elle était jusque-là inconnue en France. Nous corrigeons la première détermination publiée en 1999 sous le nom de B. fruticulosa Cyr. Nous donnons aux botanistes francophones les éléments descriptifs permettant d'identifier B. barrelieri et d'éviter les confusions avec les espèces voisines. Après avoir indiqué les localisations des stations, la nature du sol et le climat, nous faisons part de nos observations sur le terrain : morphologie et phénologie de l'espèce, inventaire floristique partiel. Une étude de numération chromosomique complète ces observations. Enfin, nous tentons de définir l'origine de l'implantation de B. barrelieri dans ce secteur de la Loire. En conclusion, nous estimons que cette espèce est naturalisée en France, nous invitons les botanistes à la rechercher dans les régions siliceuses, et nous proposons que des études comparatives soient effectuées dans les herbiers français.Brassica barrelieri (L.) Janka (Brassicaceae) nueva especie para Francia, naturalizada en el departamento del Loira Brassica barrelieri (L.) Janka es una planta de la Peninsula Ibérica (Espana y Portugal) citada también en Africa del Norte. Descubierta recientemente en el departamento del Loira, su presencia en Francia era desconocida hasta el momento. Se corrige la primera determinación publicada en 1999 bajo el nombre de B. fruticulosa Cyr. y se proporciona a los botánicos francofonos los caractères que permiten identificar B. barrelieri y evitar confusiones con otras especies afines. Tras dar cuenta de las localidades précisas, se indica el tipo de suelo y clima y se comunican varias observaciones hechas "in situ" sobre la morfología y fenología de la especie, anadiendo un estudio del numéro cromosômico y un inventario florístico parcial. Por ultimo, se intenta définir el origen de la presencia de B. barrelieri en este sector del Loira. Consideramos, en conclusión, que esta especie se ha naturalizado en Francia, invitamos a los botánicos a buscarla en otras regiones siliceas y proponemos que se efectuen algunos estudios comparativos en los herbarios franceses.Cornier Bruno, Girod Christophe. Brassica barrelieri (L.) Janka (Brassicaceae), plante nouvelle pour la France naturalisée dans le département de la Loire. In: Bulletin mensuel de la Société linnéenne de Lyon, 71ᵉ année, n°2, février 2002. pp. 75-88

ZnO and its doped structures for the applications in LEDs, solar cells and gas sensors

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A rapidly developing market of white LEDs requires new solutions for replacing the rare earth-based phosphors, as 95 % of these materials come from China, creating a monopoly disadvantageous for other countries and a risk for the wide deployment of white LED technology in the coming years. Ona alternative to these rare-earth based phosphors is ZnO. It is a wide bandgap semiconductor, cheap, non-harmful and abundant in nature and it can emit visible light, from yellow to red, depending on the nature of the crystalline and surface defects [1]. IRCELyon recently developed a quick and convenient chemical sol-gel approach to obtain a unique mesospheric self-assembly of ZnO nanoparticles in a hybrid system with intense and stable photoluminescent quantum yield (PL QY) of 40-75 % [1]. This high PL QY is possible thanks to a so-called down-shifting (DS) process, a variant of the down-conversion. This synthesis route uses the mixture of commercially available polyacrylic acid (PAA)-based polymers and can provide large scale amounts of ZnO NPs in clear water suspensions which can be dried and dispersed again in water without compromising the performance (e.g. transparency and PL QY) of the final DS layer. We present the effects of the ZnO NPs surface functionalization and the influence of various doping atoms in ZnO NPs on their photoluminescence spectrum and the PL QY, in order to be able to favor and boost a desired color of emission.References:1.Y. Zhu, A. Apostoluk, P. Gautier, A. Valette, T. Cornier, J. Bluet, K. Masenelli-Varlot, S. Danièle, B. Masenelli, Scientific Reports 6, pp. 23557 (1-11), 2016.

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Soil characteristics, heavy metal availability and vegetation recovery at a former metallurgical landfill: Implications in risk assessment and site restoration

International audiencePedological and botanical characteristics of a former metallurgical landfill were examined to assess the risks of heavy metals mobility and to evaluate remediation feasibility. In addition to very high heavy metals levels (Cu, Cr, Mn, Ni, Pb, Zn), the soil was characterized by a lack of clear horizonation, a relatively high pH, a high mineral and organic carbon contents, a low nitrogen level and a high C/N ratio. A two step sequential extraction showed that heavy metals were poorly labile (i.e. not soluble in diluted CaCl2), indicating that their leaching under natural conditions was probably very low. However, extraction with DTPA generated significant amounts of metals (mainly Pb and Cu), suggesting they were potentially mobilizable. A botanical survey of the area showed a biodiverse plant community (28 species and 11 families), with no obvious toxicity symptoms. Measurements of metal contents in dominant species confirmed that they were closely similar to those reported for species growing in unpolluted environments. Consequently, for an effective site restoration, indigenous species could be well suited to cope with local conditions in a phytostabilization strategy. Heavy metals at a former metallurgical landfill are not leachable and poorly phytoavailable

Doping ZnO inorganic-organic nanohybrids with metal elements

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