World Health Organisation test applied on Culicoides: a multicentric study

The aim of this work is to organize a multicentric assay to compare susceptibilities of Culicoides populations to insecticides (i.e. C. imicola and C. obsoletus sensu stricto). The base line of the World Health Organisation test kit (WHO/VBC81.805) is to expose mosquitoes to papers impregnated with insecticides to detect the resistance of Anopheles (paludism vector) in the field. In a novel approach, the WHO test can be used on Culicoides to assess midges' susceptibility to insecticides. Information on the intrinsic susceptibilities to insecticides is required to assess correctly the existing (or new) formulations of insecticide. This multicentric assay will improve our capacity to experiment by networking and assess the population variability by comparing susceptibilities between different populations of Culicoides. Field-collected midges are trapped alive using an ultraviolet light trap (OVI model, South Africa) and replacing the collection jar with a fine mesh cage. To prevent desiccation, cages are covered with wet papers, wrapped in aluminium foil and retrieved at dawn. It is important to choose the site and period with abundant target species to improve robustness with more individuals. Experiments should be carried out in an insecticide-free environment with constant temperature and humidity, and started a few hours after collection. Insecticide-impregnated papers are rolled and fastened into the WHO kit test tube. About 30 Culicoides (approximately 20 nulliparous females) are collected and transferred to the tube. Tubes are maintained horizontally for an hour (exposure to insecticide). Mortalities are recorded 1 h and 24 h after exposure. One control is performed without insecticide to validate the test. Mortalities are analysed by probit regression to obtain LC50 and LC90 for each population. The test has to be run at least with four concentrations of insecticide, one control and four replicates with samples from the same population. Only nulliparous females are recorded. Insecticide concentrations are given in percentages (WHO standard). In this WHO test, the target species are C. imicola and C. obsoletus s.s., and the active ingredient used is deltamethrin at doses 0.005, 0.001, 0.0005 and 0.0001%. Data will be centralized and analysed by EID-Méditerranée (France), and results will be given back to the partners and published. Future studies could focus on comparing the four deltamethrin concentrations on other species and testing Culicoides susceptibility to other components. (Texte intégral

Wave Finite Element based Strategies for Computing the Acoustic Radiation of Stiffened or Non-Stiffened Rectangular Plates subject to Arbitrary Boundary Conditions

20 pagesInternational audienceThe wave finite element method (WFE) is investigated for the computation of the acoustic radiation of stiffened or non-stiffened rectangular plates under arbitrary boundary conditions. The method aims at computing the forced response of periodic waveguides (e.g. rectangular plates that are homogeneous or that contain a periodic distribution of stiffeners) using numerical wave modes. A WFE-based strategy is proposed which uses the method of elementary radiators for expressing the radiation efficiencies of stiffened or non-stiffened baffled rectangular plates immersed in a light acoustic fluid. In addition, a model reduction strategy consisting in using reduced wave bases for computing these radiation efficiencies with small CPU times is proposed. Numerical experiments highlight the relevance of the strategies

A comparison of soft and hard decision-directed feedforward phase estimators

Publication in the conference proceedings of EUSIPCO, Florence, Italy, 200

Coping with Information Disruption in A Simple Multi-Actor Information System

Information and knowledge management have become crucial to the development of a competitive edge on the market. This requires the gathering of complete and consistent information in an environment where companies are working increasingly with a vast network of partners. In this paper, we investigate the case of platforms on the tourism market selling trips in boxes thanks to a wide network of partners upstream (service providers) and downstream (distribution network). A particular case feature here is that the product is bought to be gifted which increases the complexity of the information gathering process. The information needs are defined as well as the potential information gaps.  Solutions are discussed in order to reach information consistency through greater Information System integration: bridging information gaps appears to be mostly feasible but still leaves one actor in the shade. Platforms in the tourism market, even though they may get a good degree of qualitative information, will not achieve perfect information

Asymptotic Analysis and Design of Iterative Receivers for Non Linear ISI Channels

International audienceIn this paper, iterative receiver analysis and design for non linear satellite channels is investigated. To do so, an EXtrinsic Information Transfer (EXIT) chart-based optimization is applied using two major assumptions: the equalizer outputs follow a Gaussian Mixture distribution since we use non-binary modulations and partial interleavers are used between the Low Density Parity Check (LDPC) code and the mapper. Achievable rates, performance and thresholds of the optimized receiver are analysed. The objective in fine is to answer the question: Is it worth optimizing an iterative receiver for non linear satellite channels

On Linear Frequency Domain Turbo-Equalization of Non Linear Volterra Channels

International audienceThis article deals with iterative Frequency Domain Equalization (FDE) for Single Carrier (SC) transmissions over Volterra non linear satellite channels. SC-FDE has gained much importance in recent research for its efficient implementation at the receiver and its interesting low Peak to Average Power Ratio (PAPR) at the transmitter. However, nearly saturated power amplifiers on board satellites generate linear and non linear Inter Symbol Interference (ISI) at the receiver. It is thus interesting to investigate the implementation of SC-FDE for non linear channels. To do so, a frequency domain equivalent satellite channel is derived based on the time domain Volterra series representation of the non linear channel. Then a Minimum Mean Square Error (MMSE)-based iterative frequency domain equalizer is designed. It is shown that the proposed equalizer consists of a Soft Interference Canceller (SIC) which subtracts both the linear and non-linear soft frequency symbols. The equalizer performance is then compared to the equivalent time domain implementation. Results show that a channel-memory independent efficient implementation is achieved at the price of a negligible spectral efficiency loss due to cyclic prefix insertion

On linear MMSE based turbo-equalization of nonlinear Volterra channels

International audienceThis article deals with Minimum Mean Square Error (MMSE) turbo equalization of nonlinear interference using a volterra series decomposition of the underlying nonlinear channel. Although it has been often argued that linear MMSE based equalization is unsuited for cancelling nonlinear interference, we show that this common belief is not true in a strict sense. By a proper derivation of the linear based MMSE soft equalizer, we are able to show that the underlying structure of the equalizer is equivalent to a Soft Interference Canceller (SIC) treating both the linear and nonlinear interference. Based on these results, approximations are provided for lowering the computational complexity. Links to previously proposed “nonlinear” SIC are emphasized showing that the previously proposed structures are nothing but approximations of a linear MMSE receiver applied to nonlinear ISI channels. Simulations show that significant improvements can be achieved by using the proposed exact and approximate MMSE based turbo-equalizers

Aide à la communication informatisée dans les TED

National audienceAprès avoir rappelé les symptômes de l'autisme comme pathologie neuro-développementale qui appartient aux Troubles Envahissants du Développement (TED), nous étudions les principes et les caractéristiques des supports visuels (classeurs traditionnels et tablettes électroniques) destinés aux enfants autistes afin qu'ils puissent communiquer avec leur entourage (famille et personnes chargées du suivi thérapeutique, éducatif ou pédagogique). Nous présentons les fonctionnalités d'un prototype innovant fonctionnant sur tablette électronique que nous avons développé (paramétrage des utilisateurs, du lexique, de la syntaxe des messages, mémorisation d'un journal des interactions, ...). Nous exposons les modalités de l'expérience que nous allons mener auprès de jeunes enfants autistes de moins de 6 ans dans le cadre de leur accueil au CATTP ISATIS (CH St-Jean-de Dieu) et dans leur cadre familial