Entomological and functional role of floral strips in an organic apple orchard: Hymenopteran parasitoids as a case study

Habitat manipulation techniques improve the availability of resources required by natural enemies to increase their effectiveness. This study focused on the effects of floral strips on Hymenopteran parasitoid presence. The experiments were conducted during spring 2007 in one organic low-input apple orchard located in south-eastern France. The density and the diversity of parasitic wasps collected from sown floral strips were higher than those from mown plants. The family of parasitic wasps of Braconidae was strongly dominant, followed by Mymaridae and Pteromalidae. By studying 26 flowering species, the greatest diversity and density of parasitic wasps were collected from Potentilla reptans, Achillea millefolium, Trifolium repens and Torilis arvensis. In terms of the early flowering plants, the most important results were observed in Euphorbia helioscopia, Senecio vulgaris and Veronica persica. To give an idea of the functional role of these plants, we studied the parasitic wasps of the diapausing larvae (cocoon) of codling moth Cydia pomonella. We recorded three emerged species: Ascogaster quadridentata, Pristomerus vulnerator and the hyperparasite Perilampus fulvicornis. However, none of these species have been observed on the 26 studied plants. Hence, this result may be suggesting that the studied plants do not have a functional role concerning these parasitoids. These studies may be advantageous for biological control programs in order to select flowering plant species attracting parasitic wasps specific to fruit pests

High-speed rail reshaping urban areas: Valencia Parque Central

International audienceSince October 2010, Valencia has been connected to Madrid by the third radial high-speed rail axis. The city now intends to reach a nodal position within the network, thanks to its selected situation on the "Mediterranean corridor" project. The implementation of the AVE (Spanish high speed rail) reactivated Valencia Parque Central project, which aim is to transform disused railways into a park and to build a station and its tracks underground. AVE's implementation in Valencia is a major political issue at all scales. The institutions of Valencia's autonomous Community called for the AVE, which is supposed to boost tourism and regional economy, and to consolidate its position of outer harbour and beach of Madrid. The second issue concerns cities more directly. The realisation of a new railway station is an old project, but it is made possible, even necessary, with the arrival of the AVE. This project of a new station relies on an ambitious underground infrastructure, above which an urban park of 23ha and a business district should be created, giving the city a new centrality. Behind this project, there is a challenge for mobility at a metropolitan scale in Valencia. Parque Central concrete project is limited to the development of a business district in a section of the city, and remedial measures to improve the interconnection of networks.Depuis octobre 2010, Valence est connectée à madrid par le troisième axe ferroviaire à grande vitesse. Aujourd'hui, la ville tente d'atteindre une position nodale dans le réseau, grâce à sa place privilégiée sur le "Corridor méditerranéen". La mise en place de l'AVE a réactivé le projet de Valencia Parque Central, dont le but est de transformer des friches ferroviaires en parc et de construire une gare souterraine. La mise en place de l'AVE à Valence est une question politique majeure à tous les échelons. Les institutions de la Communauté autonome de Valence ont réclamé l'AVE, censé dynamiser le tourisme et l'économie régionale, et consolider sa position de port et de plage de Madrid. La deuxième question concerne la ville. La réalisation d'une nouvelle gare est un projet ancien, rendu possible voire nécessaire par l'arrivée de l'AVE. Ce projet repose sur une infrastructure souterraine ambitieuse au-dessus de laquelle un parc urbain de 23ha et un quartier d'affaires seraient créés. Enfin, derrière ce projet se cache un enjeu majeur pour la mobilité urbaine. Parque Central se limite au développement d'un quartier d'affaires dans une petite partie de la ville et à quelques mesures pour remédier au manque d'interconnexion des transports urbains

The effect of phosphorus on the iron redox ratio, viscosity, and density of an evolved ferro-basalt

Despite the abundant evidence for the enrichment of phosphorus during the petrogenesis of natural ferro-basalts, the effect of phosphorus on the physical properties of these melts is poorly understood. The effects of phosphorus on the viscosity, density and redox ratio of a ferro-basaltic melt have been determined experimentally. The viscosity measurements were obtained using the concentric cylinder method on a ferro-basaltic melt above its liquidus, at 1 atm, in equilibrium with air and with CO2. The density measurements were performed using the double Pt-bob Archimedean method at superliquidus conditions under 1 atm of air. The redox ratio was obtained by wet chemical analysis of samples collected during physical property measurements. Phosphorus pentoxide reduces ferric iron in ferro-basaltic melt. The reduction due to P2O5 is much larger than that for most other oxide components in basaltic melts. A coefficient for the reduction of ferric iron has been generated for inclusion in calculation schemes. The effect of P2O5 on the viscosity is shown to be complex. The initial reduction of ferric iron with the addition of P2O5 results in a relatively small change in viscosity, while further addition of P2O5 results in a strong increase. The addition of phosphorus to a ferro-basaltic melt also reduces the density. A partial molar volume of 64.5±0.7 cm3/mol for P2O5 in this melt has been obtained at 1300° C, yielding a volume of 12.9 cm3/mol per oxygen, consistent with a tetrahedral coordination for this high field strength cation. The effects of P2O5 on redox state, density and viscosity provide constraints on the structural role of phosphorus in these melts. The results suggest a complex interaction of phosphorus with the aluminosilicate network, and tetrahedral ferric iron. In light of the significant effects of phosphorus on the physical and chemical properties of ferro-basaltic liquids, and the extreme enrichments possible in these liquids in nature, the role of phosphorus in these melts should, in future, be considered more carefully

Action and semantics of time in agro-ecology

In the systemic approach, the system is perceived as an action or a collection of overlapping actions expressed in reference to Time, Space, and Morphology (or Energy). When the system is studied by different disciplines, the referentials differ, as well as the semantics of terms used to describe the action. In order to establish the vocabulary of a collection of actions involving several disciplines, we propose a formal method for describing each action. The linguistic-based method enables (i) transcription of the literal description of an action in a semantic network, and (ii) building of a vocabulary in a formal setting. The method is illustrated through a complex biological system, i.e. the mutualistic relationship between two vine pests, while focusing particularly on temporality. The method provides a support for implementing multidisciplinary around a complex system. (Résumé d'auteur

L'AVE, opérateur et révélateur des dynamiques institutionnelles et territoriales en Espagne

National audienceL'anal yse d'un projet de corridor ferroviaire mixte (c'est-à-dire combinant trafic de voyageurs et de marchandises) à grande vitesse reliant les pôles du littoral méditerranéen espagnol est l'objet central de cette étude. Elle est menée dans la perspective d'une recherche portant sur les liens entre ces types de réseaux spécifiques que sont les corridors avec les territoires à diffé-rentes échelles et avec les opérateurs politiques ou économiques à différents ni-veaux 1. En effet, à la veille de la révision du schéma des réseaux transeuropéens de transport qui a lieu de 2009 à octobre 2011, ce sujet a été au centre d'une intense dynamique publique et collective, marquée par d'innombrables col-loques, conférences et forums. Il a également fait l'objet d'une prise en charge médiatique omniprésente, qui a accompagné l'organisation des négociations entre les différents réseaux d'acteurs (institutionnels, économiques, ou issus de la société civile – notamment universitaires) afin d'inscrire ce projet à l'agenda des instances européennes, nationales, régionales et provinciales. 1-Jean Debrie, Claude ComTois, « Une relecture du concept de corridors de transport : illustration comparée Europe/Amérique du Nord », Les Cahiers scientifiques du transport, n° 58 (2010), p. 127-144

High temperature behavior of electrostatic precipitator ash from municipal solid waste combustors

International audienceMunicipal solid waste (MSW) flue gas residues require further treatment prior to disposal or reuse, and vitrification is one of the main solidification-stabilization processes.This paper investigates the high temperature behavior of MSW flue gas residues, performed in laboratory experiments up to 1400°C, and coupled with thermogravimetric analyses, X-ray diffraction, chemical and electron microprobe analyses. Melting temperatures of electrostatic precipitator (ESP) ash are in the range of 1202-1272 °C, whereas semi-dry scrubber residues melt between 1900 and 2300 °C. The mean liquidus temperature of flue gas residues can be simply evaluated as a function of their CaO content, by using the CaO-SiO2-Al2O3 ternary diagram. For ESP ash, the liquidus phase is a Zn-rich aluminous spinel, followed by anorthite at 1225 °C, and melilite at 1190 °C. The total mass loss reaches 18 wt.% at 1300 °C. Moreover, 90% of evaporation takes place below 1000 °C, linked to evaporation of C, Cl, S, Na, K, and of the toxic metals Hg, Cd, Pb, Cu. Due to the high partial pressure of chlorine during heating, chloride is the most probable form of evaporation for Cd, Pb, and Cu. However, most of Zn, Cr, Ni, Sb and Sn remain in the vitrified product

Graphs for Ontology, Law and Policy

Le livre est en accès libre. The book is in open acces