Reconstruire Haïti après le séisme de janvier 2010: réduction des risques, cultures constructives et développement local

International audienceCet ouvrage présente une synthèse des résultats d'un travail mené par de nombreuses organisations haitiennes et internationales qui ont décidé de rassembler leurs forces en vue de répondre au mieux aux problèmes posés par la reconstruction de l'habitat suite au séisme de janvier 2010 en Haïti. L'approche qui y est proposée est issue de réflexions menées de concert lors de plusieurs rencontres internationales sur le sujet et que l'on peut résumer par la valorisation des cultures constructives locales afin d'apporter une meilleure réponse des programmes d'habita

Fuzzy Control to Drive Car-Like Vehicles

International audienceThe reactive component of a motion control architecture (called EM) for a car-like vehicle intended to move in dynamic and partially known environments is presented in this paper. Its purpose is to generate commands for the servo-systems of the vehicle so as to follow a given nominal trajectory while reacting in real-time to unexpected events. EM is designed as a fuzzy controller. A behaviour-based approach is used to set up the fuzzy rule base: the overall behaviour of the vehicle results from the combination of several basic behaviours (trajectory following, obstacle avoidance, etc.). This approach permits an easy and incremental construction of the fuzzy rule base and also to develop and test the basic behaviours separately. EM has been implemented and tested on a real computer-controlled car equipped with sensors of limited precision and reliability. Experimental results obtained with the prototype vehicle are presented. They demonstrate the capability of EM to actually control a real vehicle and to perform trajectory following and obstacle avoidance in real outdoor environments by using simple fuzzy behaviours relying upon low-resolution sensor data

Selection of coals of different maturities for CO2 Storage by modelling of CH4 and CO2 adsorption isotherms

International audienceCO2 injection in unmineable coal seams could be one interesting option for both storage and methane recovery processes. The objective of this study is to compare and model pure gas sorption isotherms (CO2 and CH4) for well-characterised coals of different maturities to determine the most suitable coal for CO2 storage. Carbon dioxide and methane adsorption on several coals have been investigated using a gravimetric adsorption method. The experiments were carried out using both CO2 and CH4 pure gases at 25 °C from 0.1 to 5 MPa (1 to 50 bar). The experimental results were fitted using Temkin's approach but also with the corrected Langmuir's and the corrected Tóth's equations. The two last approaches are more accurate from a thermodynamical point of view, and have the advantage of taking into account the fact that experimental data (isotherms) correspond to excess adsorption capacities. These approaches allow better quantification of the adsorbed gas. Determined CO2 adsorption capacities are from 0.5 to 2 mmol/g of dry coal. Modelling provides also the affinity parameters of the two gases for the different coals. We have shown these parameters determined with adsorption models could be used for classification and first selection of coals for CO2 storage. The affinity ratio ranges from a value close to 1 for immature coals to 41 for high rank coals like anthracites. This ratio allows selecting coals having high CO2 adsorption capacities. In our case, the modelling study of a significant number of coals from various ranks shows that anthracites seem to have the highest CO2 storage capacities. Our study provides high quality affinity parameters and values of CO2 and CH4 adsorption capacities on various coals for the future modelling of CO2 injection in coal seams

Exposure to vancomycin causes a shift in the microbial community structure without affecting nitrate reduction rates in river sediments

International audienceAntibiotics and antibiotic resistance genes have shown to be omnipresent in the environment. In this study, we investigated the effect of vancomycin (VA) on denitrifying bacteria in river sediments of a Waste Water Treatment Plant, receiving both domestic and hospital waste. We exposed these sediments continuously in flow-through reactors to different VA concentrations under denitrifying conditions (nitrate addition and anoxia) in order to determine potential nitrate reduction rates and changes in sedimentary microbial community structures. The presence of VA had no effect on sedimentary nitrate reduction rates at environmental concentrations, whereas a change in bacterial (16S rDNA) and denitrifying (nosZ) community structures was observed (determined by polymerase chain reaction-denaturing gradient gel electrophoresis). The bacterial and denitrifying community structure within the sediment changed upon VA exposure indicating a selection of a non-susceptible VA population

Interpreting ELISA analyses from wild animal samples: some recurrent issues and solutions

Many studies in disease and ecological immunology rely on the use of assays that quantify the amount of specific antibodies (immunoglobulin) in samples. Enzyme‐linked immunosorbent assays (ELISAs) are increasingly used in ecology due to their availability for a broad array of antigens and the limited amount of sampling material they require. Two recurrent methodological issues are nevertheless faced by researchers: (1) the limited availability of immunological assays and reagents developed for non‐model species, and (2) the statistical determination of the cut‐off threshold used to distinguish individual samples that are likely to have or not to have antibodies against a specific antigen. Here, we outline two solutions to deal with these issues. First, we show that implementing two assays with differing detection methods can help validate the use of reagents, such as antibodies, in species different from their intended target. We illustrate this by comparing the quantification of specific vaccinal antibodies against Newcastle disease virus (NDV) using two ELISA approaches in four seabird species (Cory's shearwater, European shag, European storm petrel and Southern rockhopper penguin). Second, we provide a simple way to determine from the distribution of ELISA values whether the assayed samples are likely to be made of a single group of individuals (likely negative) or of two groups of individuals (negative and positive). We illustrate the use of this approach with two independent datasets: NDV antibody levels following vaccination and anti‐Borrelia antibody levels following natural exposure. The practical implementation of these methodological approaches could provide a way to efficiently apply ELISAs and other immune‐based assays to address questions in the growing fields of ecological immunology and disease ecology

Reflexion and Diffraction of Internal Waves analyzed with the Hilbert Transform

We apply the Hilbert transform to the physics of internal waves in two-dimensional fluids. Using this demodulation technique, we can discriminate internal waves propagating in different directions: this is very helpful in answering several fundamental questions in the context of internal waves. We focus more precisely in this paper on phenomena associated with dissipation, diffraction and reflection of internal waves

System identification of the intrabrain tumoral uptake of multifunctional nanoparticles

International audienceRecent developments on multifunctional nano-systems have opened new perspectives for tumor control by proposing new nano-actuators and nano-sensors in in vivo anti-cancer treatments. But the delivery control of these nano-agents into the cancer cells is one of the major factors that directly affect the efficiency of nanotherapies. In this study, we show that system identification methods (CONTSID Matlab toolbox), generally used in control engineering, can bring efficient solutions to help biologists to estimate crucial parameters of the nanoparticles pharmacokinetics from experimental data. The in vivo results presented herein clearly emphasize the relevance of these data-driven modeling approaches associated with magnetic resonance imaging

(Re)construire en Haïti 2010-2019 : l’émergence du concept de TCLA

International audienceCette publication présente une synthèse des résultats du travail mené par CRAterre depuis 2010 en partenariat avec des organisations haïtiennes et internationales, travail qui, en 2018, a reçu l’un des prestigieux Prix Mondial de l’Habitat (mention spéciale). Ce prix récompense les projets et programmes d’habitat exemplaires ou innovants qui contribuent concrètement à résoudre les problèmes de logement aux quatre coins du monde