Detection of Babesia divergens in southern Norway by using an immunofluorescence antibody test in cow sera

<p>Abstract</p> <p>Background</p> <p>The incidence of bovine babesiosis, caused by <it>Babesia divergens </it>(Apicomplexa: Piroplasmida) has decreased markedly since the 1930 s, but may re-emerge as a consequence of climate change and changes in legislation and pasturing practices. This is a potentially serious disease, with both economical and animal welfare consequences. Therefore, there is a need to survey the distribution of <it>B. divergens</it>.</p> <p>Methods</p> <p>We tested sera from 306 healthy pastured cows from 24 farms along the southern Norwegian coast by using an indirect immunofluorescence IgG antibody test (IFAT). Fractions of seropositive cows were compared by calculating 95% CI.</p> <p>Results</p> <p>The results of this test showed that 27% of the sera were positive for <it>B. divergens </it>antibodies. The fraction of antibody-positive sera that we detected showed a two-humped distribution, with a high fraction of positives being found in municipalities in the western and eastern parts of the study area, while the municipalities between these areas had few or no positive serum samples.</p> <p>Conclusions</p> <p>Neither the farmers' observations nor the Norwegian Dairy Herd Recording System give an adequate picture of the distribution of bovine babesiosis. Serological testing of cows by using IFAT is a convenient way of screening for the presence of <it>B. divergens </it>in an area.</p

Dynamical analysis of homogenized second gradient anisotropic media for textile composite structures and analysis of size effects

International audienceIn order to predict the dispersion relation of 3D composite structures in the low frequency range, we construct effective first and second order grade continuum models. The effective properties of textile composites are obtained computationally by an equivalent strain energy method based on the response of the representative volume unit cell (RUC) under prescribed boundary conditions as described in Goda and Ganghoffer (2016). The expressions of the phase velocities for the three modes of wave propagation in a 3D context (longitudinal, horizontal shear and vertical shear) reveal that the second order continuum is dispersive, due to the presence of the second order elasticity constants. The shape change of the phase velocity when increasing the wave number shows the dispersive behavior of the second gradient medium, whereas Cauchy medium is non dispersive. Plots of the iso-frequency contour for the two investigated composites in the case of second gradient and Cauchy effective medium show that the second gradient contributions does not modify the anisotropic behavior of the considered composites. Important size effects on the dynamical behavior are shown, especially reflected by the dispersive behavior and the anisotropic dynamic responses, due to the significant overall increase of the second order rigidity matrix when increasing the RUC size

A coupled carbonation- rust formation-mechanical damage model for steel corrosion in reinforced concrete

WOS:000341010300007International audienceThis paper aims at presenting a strategy to simulate the corrosion of steel reinforcement due to carbonation of concrete in atmospheric environment. We propose a model coupling drying, carbonation, diffusion of oxygen, formation of rust and mechanics to describe these phenomena. The rust layer is assumed to be composed of two sub-layers with different elastic modulus. An unstable layer with a low modulus (from 0.1 to 5 GPa) is located next to the transformed medium, and another more stable one with a higher modulus (from 100 to 150 GPa) at the interface with steel reinforcement. This model is applied to a numerical mesostructure composed of 4 phases: mortar matrix, randomly distributed aggregates, steel rebar and rust layers to underline the effect of aggregates on damage initiation and corresponding crack pattern of concrete cover

An urbanism oriented towards rail in Germany and France, three main findings of a research-action program

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Développement de structures composites intelligentes

Depuis quelques années le CETIM-CERMAT et le LPMT développent et élaborent un nouveau type de matériau actif, le M3C, matériau composite à comportement contrôlé. Le principe de ce matériau consiste à rendre une structure composite active sans rajout d'actionneurs ou d`éléments extérieurs. L'activation du matériau est réalisée grâce à une source interne de chaleur creé par effet Joule à l'aide de renforts actifs. L'objectif de cette présentation consiste, dans un premier temps, à faire une présentation complète de ce nouveau matériau, et à situer ses performances par rapport à celles des autres matériaux intelligents, ceci en terme de domaine d'application, de puissance utile, de rendement, de temps de réponse. Dans un second temps, nous présenterons les différents outils numériques qui ont été développés afin de permettre le calcul et l'optimisation de ce matériau. Nous finirons cet article par une application potentielle du M3C

Prix et cotisations dans quelques systemes des produits agricoles et alimentaires (fruits et legumes, fleurs, porcs, poissons)

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