Conduite diagnostique et thérapeutique face à une diarrhée chronique chez le chat

La diarrhée chronique est un motif de consultation très fréquent en médecine féline. Elle est difficile à évaluer en raison de commémoratifs et de symptômes souvent frustes. Les Maladies Inflammatoires Chroniques Intestinales et le lymphome sont plus souvent diagnostiqués chez le chat que chez le chien. Le parasitisme est une cause potentielle mais apparaît généralement moins fréquente que chez le chien. L'allergie alimentaire rentre dans le diagnostic différentiel. En revanche, l'insuffisance pancréatique exocrine est très rare chez le chat comparativement au chien. L'examen clinique permet de suspecter une diarrhée d'origine spécifiquement intestinale ou une diarrhée secondaire à une affection extra-intestinale telle qu'une insuffisance rénale ou hyperthyroïdie chez un vieux chat. Une coproscopie permet de diagnostiquer une parsitose, en particulier la giardiose. Un bilan biochimique et une analyse d'urine confirment ou non une affection systèmique. Des sérologies FeLV/FIV/PIF et un dosage de la thyroxine sur les vieux chats doivent être également effectués. Ces premiers examens "simples" à réaliser et peu onéreux offrent la possibilité au clinicien de limiter le cadre étiologique et l'amènent, en cas de résultat négatif, à s'orienter vers des examens plus complexes tels que le dosage du trypsinogène sérique et l'association de techniques d'imagerie, comme l'endoscopie ou l'échographie, et de biopsies du tube digestif précisant le diagnostic. Aussi, l'approche diagnostique d'une diarrhée chronique chez le chat est-elle de plus en plus fine permettant la mise en place d'une thérapeutique diététique et médicale la mieux adaptée à chaque cas

Study of elementary micro-cutting in hardened tool steel

In order to model micro-milling cutting forces, a way is to apply a local model on discretized elements of the cutting edge and then summing on the whole edge to obtain the global cutting forces. This local model is usually obtained by numerical simulation or cutting experimentation. This paper focuses on orthogonal and oblique micro-cutting experiments of AISI 6F7 with tungsten carbide tools. Results show the influence of cutting edge sharpness on cutting forces and the existence of different mechanisms corresponding to different ranges of uncut chip thickness values. A phenomenological model has been identified to model correctly these zones. Then, by comparing experimental micro-milling forces with those deduced from these micro-cutting model and tests, a good agreement has been found. In order to complete this study, phenomenological and thermo mechanical models are being developed. The aim is to obtain an elementary cutting model that can be used for micro-milling simulation and optimization

A modelling exercise on the importance of ternary alkaline earth carbonate species of uranium(VI) in the inorganic speciation of natural waters

International audiencePredictive modelling of uranium speciation in natural waters can be achieved using equilibrium thermodynamic data and adequate speciation software. The reliability of such calculations is highly dependent on the equilibrium reactions that are considered as entry data, and the values chosen for the equilibrium constants. The working group " Speciation " of the CETAMA (Analytical methods establishment committee of the French Atomic Energy commission, CEA) has organized a modelling exercise, including four participants, in order to compare modellers' selections of data and test thermodynamic data bases regarding the calculation of U(VI) inorganic speciation. Six different compositions of model waters were chosen so that to check the importance of ternary alkaline earth carbonate species of U(VI) on the aqueous speciation, and the possible uranium solid phases as solubility-limiting phases. The comparison of the results from the participants suggests i) that it would be highly valuable for end-users to review thermodynamic constants of ternary carbonate species of U(VI) in a consistent way and implement them in available speciation data bases, and ii) stresses the necessary care when using data bases to avoid biases and possible erroneous calculations

Expérimentation de la micro-coupe élémentaire sur un acier dur et comparaison au micro-fraisage

Cet article présente des essais de micro-coupe orthogonale et oblique à partir de tournage sur un acier 40NiCrMo16. Les résultats obtenus démontrent l’influence du rayon d’acuité d’arête sur les efforts mesurés notamment aux faibles épaisseurs de copeau non déformé. Les efforts spécifiques de coupe déduits sont en cohérence avec ceux obtenus lors d’essais de micro-fraisage issus de travaux précédents. Pour compléter l’étude, cet article pose les bases de la modélisation phénoménologique et thermomécanique adaptée à la micro-coupe. Le but à terme est d’obtenir un modèle de coupe élémentaire utilisable dans le cas du micro-fraisage puis de comparer les résultats obtenus aux résultats expérimentaux

Complex Networks on Hyperbolic Surfaces

We explore a novel method to generate and characterize complex networks by means of their embedding on hyperbolic surfaces. Evolution through local elementary moves allows the exploration of the ensemble of networks which share common embeddings and consequently share similar hierarchical properties. This method provides a new perspective to classify network-complexity both on local and global scale. We demonstrate by means of several examples that there is a strong relation between the network properties and the embedding surface.Comment: 8 Pages 3 Figure

Capabilité des micro-fraises en carbure de tungstène à usiner un acier à moule d'injection plastique

La présente étude constitue une approche de l'usinage d'une empreinte de moule d'injection plastique par micro-fraisage. Basée sur des résultats expérimentaux, elle permet de mettre en évidence certains phénomènes liés au procédé. Les résultats présentés résultent de l'usinage d'un acier 42NICrMo16 à l'état trempé avec des micro-fraises en carbure de tungstène revêtu de diamètre 0,5 mm. Ils seront principalement liés aux matériaux et phénomènes d'usure. Néanmoins, des aspects dynamiques de la coupe ainsi que la géométrie de l'outil seront abordés

Assessment of co–contaminant effects on uranium and thorium speciation in freshwater using geochemical modelling

Speciation modelling of uranium (as uranyl) and thorium, in four freshwaters impacted by mining activities, was used to evaluate (i) the influence of the co–contaminants present on the predicted speciation, and (ii) the influence of using nine different model/database combinations on the predictions. Generally, co–contaminants were found to have no significant effects on speciation, with the exception of Fe(III) in one system, where formation of hydrous ferric oxide and adsorption of uranyl to its surface impacted the predicted speciation. Model and database choice on the other hand clearly influenced speciation prediction. Complexes with dissolved organic matter, which could be simulated by three of the nine model/database combinations, were predicted to be important in a slightly acidic, soft water. Model prediction of uranyl and thorium speciation needs to take account of database comprehensiveness and cohesiveness, including the capability of the model and database to simulate interactions with dissolved organic matter. Measurement of speciation in natural waters is needed to provide data that may be used to assess and improve model capabilities and to better constrain the type of predictive modelling work presented here

The Radioecology Exchange

The Radioecology Exchange (www.radioecology-exchange.org) was created in 2011 under the EU FP7 STAR (STrategy for Allied Radioecology, www.star-radioecology.org) Network of Excellence; (2011-2015). This project aims to integrate radioecological research efforts of European organisations into a sustainable network. In 2013, the EU FP7 COMET (COordination and iMplementation of a pan-European instrumenT for radioecology (2013- 2017); www.comet-radioecology.org) project commenced; COMET will build upon the work initiated under STAR. The Radioecology Exchange has therefore become the web resource for activities from both projects which will ultimately be maintained by the European Radioecology Alliance (ALLIANCE; www.er-alliance.org). The Radioecology Exchange is intended to become a ‘gateway’ for information related to European (and wider) radioecological research

Adverse outcome pathways (AOPs) for radiation-induced reproductive effects in environmental species: state of science and identification of a consensus AOP network

Background Reproductive effects of ionizing radiation in organisms have been observed under laboratory and field conditions. Such assessments often rely on associations between exposure and effects, and thus lacking a detailed mechanistic understanding of causality between effects occurring at different levels of biological organization. The Adverse Outcome Pathway (AOP), a conceptual knowledge framework to capture, organize, evaluate and visualize the scientific knowledge of relevant toxicological effects, has the potential to evaluate the causal relationships between molecular, cellular, individual, and population effects. This paper presents the first development of a set of consensus AOPs for reproductive effects of ionizing radiation in wildlife. This work was performed by a group of experts formed during a workshop organized jointly by the Multidisciplinary European Low Dose Initiative (MELODI) and the European Radioecology Alliance (ALLIANCE) associations to present the AOP approach and tools. The work presents a series of taxon-specific case studies that were used to identify relevant empirical evidence, identify common AOP components and propose a set of consensus AOPs that could be organized into an AOP network with broader taxonomic applicability. Conclusion Expert consultation led to the identification of key biological events and description of causal linkages between ionizing radiation, reproductive impairment and reduction in population fitness. The study characterized the knowledge domain of taxon-specific AOPs, identified knowledge gaps pertinent to reproductive-relevant AOP development and reflected on how AOPs could assist applications in radiation (radioecological) research, environmental health assessment, and radiological protection. Future advancement and consolidation of the AOPs is planned to include structured weight of evidence considerations, formalized review and critical assessment of the empirical evidence prior to formal submission and review by the OECD sponsored AOP development program