HYDROBIA ULVAE: A DEPOSIT-FEEDER FOR CLEANING LIVING HARD-SHELLED FORAMINIFERA

International audienceThis study proposes a new method for fast and inexpensive extraction of a large number of living foraminifera for laboratory cultures. The method is a significant improvement over current extraction methods, which are highly time-consuming. Several treatments were designed to test the method. Sediment bearing foraminifera from Brouage Mudflat (Atlantic coast of France) was washed through a 50-µm sieve and distributed in glass Petri dishes with 20, 40 and 80 specimens of Hydrobia ulvae, a common gastropod from European intertidal mudflats. As a control experiment, one dish was treated similarly but maintained without Hydrobia. After two days, most of the sediment in the Hydrobia treatments was compacted into small cylindrical gastropod feces and the tests of living benthic foraminifera (Ammonia tepida and Haynesina germanica) were clean and easily visible. Additional experiments showed that the foraminifera were not ingested by Hydrobia ulvae, and could be picked quickly and easily

Modelling waving crops using large-eddy simulation: Comparison with experiments and a linear stability analysis

International audienceIn order to investigate the possibility of modelling plant motion at the landscape scale, an equation for crop plant motion, forced by an instantaneous velocity field, is introduced in a large-eddy simulation (LES) airflow model, previously validated over homogeneous and heterogeneous canopies. The canopy is simply represented as a poroelastic continuous medium, which is similar in its discrete form to an infinite row of identical oscillating stems. Only one linear mode of plant vibration is considered. Two-way coupling between plant motion and the wind flow is insured through the drag force term. The coupled model is validated on the basis of a comparison with measured movements of an alfalfa crop canopy. It is also compared with the outputs of a linear stability analysis. The model is shown to reproduce the well-known phenomenon of honami which is typical of wave-like crop motions on windy days. The wavelength of the main coherent waving patches, extracted using a bi-orthogonal decomposition (BOD) of the crop velocity fields, is in agreement with that deduced from video recordings. The main spatial and temporal characteristics of these waving patches exhibit the same variation with mean wind velocity as that observed with the measurements. However they differ from the coherent eddy structures of the wind flow at canopy top, so that coherent waving patches cannot be seen as direct signatures of coherent eddy structures. Finally, it is shown that the impact of crop motion on the wind dynamics is negligible for current wind speed values. No lock-in mechanism of coherent eddy structures on plant motion is observed, in contradiction with the linear stability analysis. This discrepancy may be attributed to the presence of a nonlinear saturation mechanism in LES. © 2010 Cambridge University Press

Quelle R&D Mener pour le Développement Des Réseaux D'énergie De Demain ? Les Propositions de L'ancre en 2015

Feuille de route sur les réseaux électriques et stockage élaborée par le GP10 Réseaux et Stockages de l'Energie de l'ANCRECette feuille de route concerne les réseaux d’énergie électrique, de chaleur et de froid, les réseaux de gaz (hydrogène, gaz naturel), leurs stockages associés, ainsi que leurs couplages à venir dans le cadre de la transition énergétique et des évolutionsqui l’accompagneront, que ce soit sur les modes de production d’énergie ou sur l’évolution des usages.Le focus est porté sur les réseaux électriques qui seront les premiers impactés par cette transition énergétique. Hormisquelques éléments très spécifiques aux réseaux électriques (et qui seront notés dans le texte par une couleur différente)il est à souligner que la quasi-totalité des considérations et axes de R&D évoqués pour les réseauxélectriques et le développement de leur « intelligence » et/ou de leur flexibilité s’appliquentégalement aux autres réseaux d’énergie. Par ailleurs, si le groupe programmatique« Réseaux et Stockage » de l’ANCRE (GP10) s’est largement appuyé sur les nombreuses feuilles de route émises tant au niveau national, dont celles de l’ADEME, qu’européen, il a également souhaité s’en démarquer en insistantlargement et en détaillant les recherches scientifiques et technologiques à mener face aux verrous actuellement identifiés

Research Priorities for Neglected Infectious Diseases in Latin America and the Caribbean Region

Dujardin, J. C. et al. 5 p.-1 tab.Global priorities for research in neglected infectious diseases (NIDs) can be assessed in different ways, but it is important to realize that regional priorities may significantly differ one from another. The region of Latin America and the Caribbean (LAC) is—along with Africa and Asia—more affected by NIDs than other regions of the world. Some of the Latin American NIDs are common to other continents, while others are very specific or disproportionately affect the Latin American region [1– 3] (Table 1). Because of its huge ecological diversity, ongoing environmental changes, and massive migrations, LAC is also a catalyst for the (re-)emergence and spreading of NIDs, both inside and outside the subcontinent. Following a colloquium on NIDs in LAC held in Lima, Peru, between 12 and 14 November 2009, a thematic workshop was organized with the support of the European Commission (EC). It involved 29 scientists (16 from the Americas, two from the Democratic Republic of Congo and India, respectively, and nine from Europe) working on different NIDs and representing several research areas from basic to applied. This report summarizes the consensus comments of the expert group after oral and written consultation. It is envisaged that this document should stimulate a debate within the scientific community and serve as a recommendation for future actions by international or regional funding agencies in the area of NIDs in LACThis work was supported by the Directorate-General for Development Cooperation of the Belgian Government (framework agreement 03, project 95502) and the European CommissionPeer reviewe

Identification of a Small TAF Complex and Its Role in the Assembly of TAF-Containing Complexes

TFIID plays a role in nucleating RNA polymerase II preinitiation complex assembly on protein-coding genes. TFIID is a multisubunit complex comprised of the TATA box binding protein (TBP) and 14 TBP-associated factors (TAFs). Another class of multiprotein transcriptional regulatory complexes having histone acetyl transferase (HAT) activity, and containing TAFs, includes TFTC, STAGA and the PCAF/GCN5 complex. Looking for as yet undiscovered subunits by a proteomic approach, we had identified TAF8 and SPT7L in human TFTC preparations. Subsequently, however, we demonstrated that TAF8 was not a stable component of TFTC, but that it is present in a small TAF complex (SMAT), containing TAF8, TAF10 and SPT7L, that co-purified with TFTC. Thus, TAF8 is a subunit of both TFIID and SMAT. The latter has to be involved in a pathway of complex formation distinct from the other known TAF complexes, since these three histone fold (HF)-containing proteins (TAF8, TAF10 and SPT7L) can never be found together either in TFIID or in STAGA/TFTC HAT complexes. Here we show that TAF8 is absolutely necessary for the integration of TAF10 in a higher order TFIID core complex containing seven TAFs. TAF8 forms a heterodimer with TAF10 through its HF and proline rich domains, and also interacts with SPT7L through its C-terminal region, and the three proteins form a complex in vitro and in vivo. Thus, the TAF8-TAF10 and TAF10-SPT7L HF pairs, and also the SMAT complex, seem to be important regulators of the composition of different TFIID and/or STAGA/TFTC complexes in the nucleus and consequently may play a role in gene regulation

Behavioural and Physiological Responses of Gammarus pulex Exposed to Cadmium and Arsenate at Three Temperatures: Individual and Combined Effects

This study aimed at investigating both the individual and combined effects of cadmium (Cd) and arsenate (AsV) on the physiology and behaviour of the Crustacean Gammarus pulex at three temperatures (5, 10 and15°C). G. pulex was exposed during 96 h to (i) two [Cd] alone, (ii) two [AsV] alone, and (iii) four combinations of [Cd] and [AsV] to obtain a complete factorial plane. After exposure, survival, [AsV] or [Cd] in body tissues, behavioural (ventilatory and locomotor activities) and physiological responses (iono-regulation of [Na+] and [Cl−] in haemolymph) were examined. The interactive effects (antagonistic, additive or synergistic) of binary mixtures were evaluated for each tested temperature using a predictive model for the theoretically expected interactive effect of chemicals. In single metal exposure, both the internal metal concentration in body tissues and the mortality rate increased along metallic gradient concentration. Cd alone significantly impaired both [Na+] and [Cl−] while AsV alone had a weak impact only on [Cl−]. The behavioural responses of G. pulex declined with increasing metal concentration suggesting a reallocation of energy from behavioural responses to maintenance functions. The interaction between AsV and Cd was considered as ‘additive’ for all the tested binary mixtures and temperatures (except for the lowest combination at 10°C considered as “antagonistic”). In binary mixtures, the decrease in both ventilatory and locomotor activities and the decline in haemolymphatic [Cl−] were amplified when respectively compared to those observed with the same concentrations of AsV or Cd alone. However, the presence of AsV decreased the haemolymphatic [Na+] loss when G. pulex was exposed to the lowest Cd concentration. Finally, the observed physiological and behavioural effects (except ventilation) in G. pulex exposed to AsV and/or Cd were exacerbated under the highest temperature. The discussion encompasses both the toxicity mechanisms of these metals and their interaction with rising temperature