Delocalization of slowly damped eigenmodes on Anosov manifolds

We look at the properties of high frequency eigenmodes for the damped wave equation on a compact manifold with an Anosov geodesic flow. We study eigenmodes with spectral parameters which are asymptotically close enough to the real axis. We prove that such modes cannot be completely localized on subsets satisfying a condition of negative topological pressure. As an application, one can deduce the existence of a "strip" of logarithmic size without eigenvalues below the real axis under this dynamical assumption on the set of undamped trajectories.Comment: 28 pages; compared with version 1, minor modifications, add two reference

Modelling study of the impact of deep convection on the UTLS air composition – Part 2: Ozone budget in the TTL

International audienceIn this second part of a series of two papers which aim to study the local impact of deep convection on the chemical composition of the Upper Troposphere and Lower Stratosphere (UTLS), we focus on ozone simulation results using a mesoscale model that includes on-line chemistry. A severe convective system observed on 8 February 2001 at Bauru, Brazil, is studied. This unorganised convective system is composed of several convective cells that interact with each other. We show that there is an increase in the ozone concentration in the tropical transitional layer (TTL) in the model during this event, which is compatible with ozone sonde observations from Bauru during the 2004 convective season. The model horizontal variability of ozone in this layer is comparable with the variability of the ozone sonde observations in the same area. The calculation of the ozone budget in the TTL during a 24 h period in the area of the convective system shows that the ozone behaviour in this layer is mainly driven by dynamics. The horizontal flux at a specific time is the main contribution in the budget, since it drives the sign and the magnitude of the total ozone flux. However, when averaged over the 24 h period, the horizontal flux is smaller than the vertical fluxes, and leads to a net decrease of ozone molecule number of 23%. The upward motions at the bottom of the TTL, related to the convection activity is the main contributor to the budget over the 24h period since it can explain 70% of the total ozone increase in the TTL, while the chemical ozone production inside the TTL is estimated to be 29% of the ozone increase, if NOx production by lightning (LNOx) is taken into account. It is shown that downward motion at the tropopause induced by gravity waves generated by deep convection is non negligible in the TTL ozone budget, since it represents 24% of the ozone increase. The flux analysis shows the importance of the vertical contributions during the life time of the convective event (about 8 h). The TTL ozone is driven out of the domain horizontally by the convective outflow during this period, limiting the ozone increase in this layer

Modelling study of the impact of deep convection on the UTLS air composition – Part II: Ozone budget in the TTL avenue de la Recherche Scientifique, 45071 Orléans cedex 2, France

International audienceIn this second part of a series of two papers which aim to study the local impact of deep convection on the chemical composition of the Upper Troposphere and Lower Stratosphere (UTLS), we focus on ozone simulation results using a mesoscale model that includes on-line chemistry. A severe convective system observed on 8 February 2001 at Bauru, Brazil, is studied. We show that there is an increase in the ozone concentration in the tropical transitional layer (TTL) in the model during this event, which is compatible with ozone sonde observations from Bauru during the 2004 convective season. The model horizontal variability of ozone in this layer is comparable with the variability of the ozone sonde observations in the same area. The calculation of the ozone budget in the TTL shows that the ozone behaviour in this layer is mainly driven by dynamics. The upward motions at the bottom of the TTL, related to the convection activity is the main contributor to the budget since it can explain 75% of the total ozone increase in the TTL, while the chemical ozone production inside the TTL is estimated to be 23.5% of the ozone increase if NOx production by lightning (LNOx) is taken into account. It is shown that downward motions at the tropopause induced by gravity waves generated by deep convection are non negligible in the TTL ozone budget, since it represents 11% of the ozone increase. The correlation between the convection activity and the vertical flux at 13 km, the vertical flux at 17 km, and the chemical production is brought to the fore in this simulation

Sensibilité d'Anopheles gambiae aux insecticides en Côte d'Ivoire

Des études sur la sensibilité d'#Anophles gambiae aux insecticides ont été menées dans des zones de riziculture en Côte-d'Ivoire. Les populations larvaires d'#An. gambiae de ce pays sont résistantes au DDT mais sensibles aux insecticides organophosphorés. Les populations adultes issues des environs de Bouaké sont résistantes au DDT et à la perméthrine. Elles présentent une forte présomption de résistance au propoxur. L'effet #knock-down$ de la deltaméthrine et de la lambdacyhalothrine est retardé et considérablement diminué. La souche témoin de Bobo-Dioulasso, ainsi que des populations provenant de la zone de Katiola, éloignée de la ville, sont toujours sensibles aux trois pyréthrinoïdes. La résistance aux pyréthrinoïdes dans Bouaké a peut-être été sélectionnée par l'utilisation intensive des bombes insecticides à usage domestique. (Résumé d'auteur

Modelling the reversible uptake of chemical species in the gas phase by ice particles formed in a convective cloud

The present paper is a preliminary study preparing the introduction of reversible trace gas uptake by ice particles into a 3-D cloud resolving model. For this a 3-D simulation of a tropical deep convection cloud was run with the BRAMS cloud resolving model using a two-moment bulk microphysical parameterization. Trajectories within the convective clouds were computed from these simulation outputs along which the variations of the pristine ice, snow and aggregate mixing ratios and concentrations were extracted. The reversible uptake of 11 trace gases by ice was examined assuming applicability of Langmuir isotherms using recently evaluated (IUPAC) laboratory data. The results show that ice uptake is only significant for HNO<sub>3</sub>, HCl, CH<sub>3</sub>COOH and HCOOH. For H<sub>2</sub>O<sub>2</sub>, using new results for the partition coefficient results in significant partitioning to the ice phase for this trace gas also. It was also shown that the uptake is largely dependent on the temperature for some species. The adsorption saturation at the ice surface for large gas mixing ratios is generally not a limiting factor except for HNO<sub>3</sub> and HCl for gas mixing ratio greater than 1 ppbv. For HNO<sub>3</sub>, results were also obtained using a trapping theory, resulting in a similar order of magnitude of uptake, although the two approaches are based on different assumptions. The results were compared to those obtained using a BRAMS cloud simulation based on a single-moment microphysical scheme instead of the two moment scheme. We found similar results with a slightly more important uptake when using the single-moment scheme which is related to slightly higher ice mixing ratios in this simulation. The way to introduce these results in the 3-D cloud model is discussed

Des indicateurs en santé travail - Les troubles musculo-squelettiques du membre supérieur en France

France has sought to develop a series of indicators intended to monitor health trends at the national level. Since its creation in 1998, the Department of Occupational Health (DST) of the French Institute of Public Health Surveillance (InVS) has worked to develop monitoring programs, with the goal of producing such data regularly and thus improving our knowledge of occupational health risks. The data sources have expanded over time. In 2009, the DST established a program for the regular production of indicators intended to report the national workplace health situation and its trends over time. These indicators come from various sources and will be published regularly on the InVS website: www.invs.sante.fr. This third report covers musculoskeletal diseases of the upper limbs. This document summarizes data about their frequency in terms of prevalence and incidence, as well as about the frequency of exposures to the principal known risk factors, according to sex, age, occupational categories, and broad activity sectors. It also provides information about the proportion of these musculoskeletal diseases that are attributable to work, according to occupational categories and broad activity sectors, and about the scale of their under-reporting generally and as compensable occupational diseases. Finally, some questions enable us to put the results presented into perspective

Entropy of semiclassical measures for nonpositively curved surfaces

We study the asymptotic properties of eigenfunctions of the Laplacian in the case of a compact Riemannian surface of nonpositive sectional curvature. We show that the Kolmogorov-Sinai entropy of a semiclassical measure for the geodesic flow is bounded from below by half of the Ruelle upper bound. We follow the same main strategy as in the Anosov case (arXiv:0809.0230). We focus on the main differences and refer the reader to (arXiv:0809.0230) for the details of analogous lemmas.Comment: 20 pages. This note provides a detailed proof of a result announced in appendix A of a previous work (arXiv:0809.0230, version 2

Boojums in Rotating Two-Component Bose-Einstein Condensates

A boojum is a topological defect that can form only on the surface of an ordered medium such as superfluid $^3$He and liquid crystals. We study theoretically boojums appearing between two phases with different vortex structures in two-component BECs where the intracomponent interaction is repulsive in one phase and attractive in the other. The detailed structure of the boojums is revealed by investigating its density distribution, effective superflow vorticity and pseudospin texture.Comment: 4 pages, 4 figure

Quantification of potential recruitment of large woody debris in mountain catchments considering the effects of vegetation on hydraulic and geotechnical bank erosion and shallow landslides

Large woody debris (LWD) exacerbates flood damages near civil structures and in urbanized areas and the awareness of LWD as a risk is becoming more and more relevant. The recruitment of “fresh” large woody debris has been documented to play a significant role of the total amount of wood transported during flood events in mountain catchments. Predominately, LWD recruitment due to hydraulic and geotechnical bank erosion and shallow landslides contribute to high volumes of wood during floods. Quantifying the effects of vegetation on channel and slope processes is extremely complex. This manuscript therefore presents the concepts that are being implemented in a new modelling framework that aims to improve the quantification of vegetation effects on LWD recruitment processes. One of the focuses of the model framework is the implementation of the effect of spatio-temporal distribution of root reinforcement in recruitment processes such as bank erosion and shallow landslides in mountain catchments. Further, spatio-temporal precipitation patterns will be considered using a probabilistic approach to account for the spatio-temporal precipitation variability to estimate a LWD recruitment correction coefficient. Preliminary results are herein presented and discussed in form of a case study in the Swiss Prealps

Atomic environment and interfacial structural order of TiAlN/Mo multilayers

Multilayered TiAlN/Mo coatings were deposited by dc reactive magnetron sputtering in a custom-made chamber. In order to assess the composition of these coatings, a combined study of Extended X-ray Absorption Fine Structure (EXAFS) and Rutherford Backscattering Spectrometry (RBS) experiments were performed. Through the simulation of the EXAFS spectra, giving the local environment of the titanium atoms inside the nitride (TiAlN), a cubic phase has been evidenced with aluminium atoms occupying titanium sites. For modulation periods in the range of 3.6–11.8 nm, RBS simulations on these multilayers also enabled the determination of the level of intermixing that occurs at the interfaces as a function of the negative bias voltage and number of layers. It was observed that the intermixing width could be as high as 2.1 nm for the roughest samples (larger periods) or as low as 0.4 nm for those with the sharpest interfaces (smaller periods).Comunidade Europeia (CE). Fundo Europeu de Desenvolvimento Regional (FEDER) -Ministério da Ciência e Tecnologia.Cooperação Científica e Tecnológica Internacional (ICCTI) - Ambassade de France in Portugal - Project no. 543 B3/2001.Fundação para a Ciência e a Tecnologia (FCT) - Programa Operacional “Ciência, Tecnologia, Inovação - POCTI/32670/CTM/2000