Détection de l’ADN de Toxoplasma gondii et évaluation des performances de deux tests sérologiques dans la viande équine vendue dans les supermarchés en France

In France, some cases of severe toxoplasmosis have been linked to the consumption of horse meat that had been imported from the American continent where atypical strains of Toxoplasma gondii are more common than in Europe. Many seroprevalence studies exist in the literature but the risk assessment of T. gondii infection after horse meat consumption is impossible because of the absence of validation of serological tests and the unknown correlation between detection of antibodies against T. gondii and presence of tissue cysts. We performed magnetic capture-polymerase chain reaction (MC-PCR) to detect T. gondii DNA in 231 horse meat samples purchased in supermarkets in France and evaluated the performance and level of agreement of the modified agglutination test (MAT) and Enzyme-linked immunosorbent assay (ELISA) in the meat juices. We also tested 196 horse sera from - institut français du cheval et de l'équitation, Chamberet, France - to assess the accuracy of ELISA, MAT and immunofluorescence antibody test (IFAT). The serological tests lacked sensitivity, specificity, agreement between them, and there was no correlation with the presence of T. gondii DNA in horse meat, raising concerns about the reliability of T. gondii seroprevalence data in horses from the literature. T. gondii DNA was detected in 43% of horse meat samples but the absence of strain isolation in mice from more than 100 horse meat samples suggest a low distribution of cysts in skeletal muscles and a low risk of T. gondii infection associated with horse meat consumption. However, to avoid any risk of toxoplasmosis, a thorough cooking of horse meat is recommended.En France, quelques cas de toxoplasmose sévère ont été liés à la consommation de viande de cheval qui avait été importée du continent américain où les souches atypiques de Toxoplasma gondii sont plus fréquentes qu’en Europe. De nombreuses études de séroprévalence existent dans la littérature mais l’estimation du risque d’infection par T. gondii après consommation de viande de cheval est impossible à cause de l’absence de validation des tests sérologiques et la corrélation inconnue entre la détection des anticorps anti T. gondii et la présence de kystes dans les tissus. Nous avons utilisé la technique de capture magnétique-réaction de polymérisation en chaine (CM-PCR) pour détecter l’ADN de T. gondii dans 231 échantillons de viande de cheval achetés dans des supermarchés en France et évalué la performance et le niveau d’agrément du test d’agglutination modifié (MAT) et de la méthode immuno-enzymatique ELISA dans les jus de viande. Nous avons également utilisé 196 sérums de chevaux provenant de l'institut français du cheval et de l'équitation à Chamberet, en France, pour évaluer la précision des tests sérologiques ELISA, MAT et le test d’immunofluorescence (IFAT). Les tests sérologiques manquaient de sensibilité, de spécificité, d’agrément entre eux et il n’y avait pas de corrélation avec la présence d’ADN de T. gondii dans la viande de cheval, ce qui suscite des doutes sur la fiabilité des données de séroprévalence de T. gondii chez les chevaux dans la littérature. L’ADN de T. gondii a été détecté dans 43% des échantillons de viande de cheval mais l’absence d’isolement de souche chez la souris suggère une faible répartition des kystes dans les muscles squelettiques et un faible risque d’infection par T. gondii avec la consommation de viande de cheval. Cependant, pour éviter tout risque de toxoplasmose, il est recommandé de bien cuire la viande

Body Maps of Resistance: Understanding everyday resistance to violent extremism in Kenya

Body Maps of Resistance is collection of personal stories and body map paintings created by twenty participants from around the Kenyan coast during two body mapping workshops held in November 2019 in Mombasa. The body mapping workshops were organised as part of a study on Gender and Resistance to Violent Extremism in Kenya funded by a British Academy ‘Tackling UK International Challenges’ award. This book explores how men and women at the level of local communities perceive, experience, and resist violent extremism in their everyday lives. The book aims to give voice to silenced narratives on communities’ everyday resistance to violent extremism. The body maps and stories in this volume, reveal complex everyday struggles against violence, discrimination and marginalisation. The paintings and stories are personal narratives that offer a window into the lives of the participants in our study and should not be used to generalise about communities living on the coast in Kenya

CHARACTERISATION OF MULTIPHASE FLUID-STRUCTURE INTERACTION USING NON-INTRUSIVE OPTICAL TECHNIQUES

The purpose of this study is to determine experimentally the effectiveness of passive drag reduction techniques (which involve adjusting surface geometry) within a chaotic multiphase flow system. To quantify the intrusion and disturbance caused, a liquid-air blast atomiser continuously discharges within a test section of air at atmospheric pressure, with a circular cylinder placed 25 cylinder diameters (250 mm) downstream of the nozzle. This cylinder is then replaced with other cylinders which have modified surface geometry. The data was obtained using Particle Image Velocimetry (PIV) and determines the fluid motion resulting from spray structure interaction of a liquid spray with a circular cylinder. Subtraction of non intruded spray images from intruded spray images at the same locations, using the time averaged analysis allows the direct comparison of the amount of disturbance each geometric variant has on the spray. Using this data alongside velocity profiles time averaged trends were compared. Drag reduction from V-shaped grooves provides the greatest disturbance reduction. This is due to the reduced shear stress around its cross section and the addition of small liquid eddies within each V-groove creates a gliding surface. These features proved to be most effective when monitoring drag reduction in multiphase flow-structure interaction

Enhancement of the direct power control applied to DFIG-WECS

This work is dedicated to the study of an improved direct control of powers of the doubly fed induction generator (DFIG) incorporated in a wind energy conversion system 'WECS'. The control method adopts direct power control 'DPC' because of its various advantages like the ease of implementation which allows decoupled regulation for active and reactive powers, as well as a good performance at transient and steady state without PI regulators and rotating coordinate transformations. To do this, the modeling of the turbine and generator is performed. Therefore, the Maximum Power Point Tracking (MPPT) technology is implemented to extract optimal power at variable wind speed conditions. Subsequently, an explanation of the said command is spread out as well as the principle of adjusting the active and reactive power according to the desired speed. Then, the estimation method of these two control variables will be presented as well as the adopted switching table of the hysteresis controller model used based on the model of the multilevel inverters. Finally, the robustness of the developed system will be analyzed with validation in Matlab / Simulink environment to illustrate the performance of this command

Application Géomatique Pour La Cartographie De La Vulnérabilité Environnementale Engendrée Par Les Déchets Miniers De La Mine Ferrifere De Nador (Nord-est du Maroc)

The field work has been done to study the impact of acid mine drainage on the environment. Space pollution measurement was carried out on the basis of interesting physicochemical and geomatic analyses of water and solid region outcrops. The study showed that the phenomenon under study represents an alarming problem that is attributed to the presence of huge stocks of mining waste sulphur, directly exposed to a Mediterranean climate and thus remains capable of accelerating the oxidation process. The classification of zones according to the levels of fragility is entailed by the necessity to opt for a model that is compatible with different intrinsic and extrinsic parameters. The study was concluded by the superposition of six thematic layers charting the environmental vulnerability map by the GIS. The findings demonstrated that most vulnerable zones near the points of exploitation are very oxidized in bottomlands or in places well apart from carbonate facies (pH <3

Applying the Upper Integral to the Biometric Score Fusion Problem in the Identification Model

This paper presents a new biometric score fusion approach in an identification system using the upper integral with respect to Sugeno's fuzzy measure. First, the proposed method considers each individual matcher as a fuzzy set in order to handle uncertainty and imperfection in matching scores. Then, the corresponding fuzzy entropy estimates the reliability of the information provided by each biometric matcher. Next, the fuzzy densities are generated based on rank information and training accuracy. Finally, the results are aggregated using the upper fuzzy integral. Experimental results compared with other fusion methods demonstrate the good performance of the proposed approach