7 research outputs found

    Convergence of row sequences of simultaneous Pad\'{e}-Faber approximants

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    We consider row sequences of vector valued Pad\'{e}-Faber approximants (simultaneous Pad\'{e}-Faber approximants) and prove a Montessus de Ballore type theorem.Comment: This paper is accepted and will be published in Journal "Mathematical Notes" V. 103, 201

    Lymphoedème unilatéral du membre supérieur au cours d’une polyarthrite rhumatoïde

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    Les lymphoedèmes chroniques et localisés des membres ne sont qu’exceptionnellement signalés au cours de la polyarthrite rhumatoïde (PR). Nous rapportons l’observation d’une patiente âgée de 63 ans ayant une PR diagnostiquée depuis dix ans et traitée par hydroxychloroquine, prednisone et méthotrexate avec une bonne évolution fût explorée pour une tuméfaction du membre supérieur gauche évoluant depuis deux ans. À l’examen clinique on notait un membre infiltré en totalité, indolore, élastique et recouvert d’une peau tendue, luisante mais d’aspect normal. Le reste de l’examen somatique était sans particularités. La biologie ne montrait pas d’anomalies. L’imagerie médicale (radiographies-X standards des os de l’avant bras et du thorax, scanner-X thoracique, échographie des parties molles et du creux axillaire, doppler artériel et veineux du membre atteint et écho-mammographie) se révélait normale. La lympho-scintigraphie concluait à l’absence de visualisation du réseau lymphatique superficiel gauche. Le diagnostic de lymphoedème secondaire associé à la PR était retenu devant la négativité du bilan étiologique. Une kinésithérapie de drainage lymphatique fût prescrite en association à des assauts cortisoniques mais l’amélioration n’était que partielle. Parmi les manifestations extra articulaires de la PR, les lymphoedèmes chroniques localisés des membres restent inhabituels et souvent méconnus. Leurs mécanismes physiopathologiques sont mal élucidés et leur traitement ne fait pas encore l’unanimité. Ils gardent en revanche une implication pronostique fonctionnelle majeure.Pan African Medical Journal 2015; 2

    Ecophysiological characterization and molecular differentiation of Culex pipiens forms (Diptera: Culicidae) in Tunisia

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    Abstract Background The Culex pipiens complex (Diptera: Culicidae) includes the most widespread mosquito species in the world. Members of this complex are the primary enzootic and epidemic vectors of the West Nile virus (genus Flavivirus) in several countries. The two recognized forms of Cx. pipiens (Linnaeus, 1758) - pipiens and molestus - exhibit behavioral and physiological differences. Natural populations of Cx. pipiens were investigated in several sites in Tunisia to evaluate the ecophysiological and molecular characteristics of their forms. Results The analysis showed the sympatric presence of Cx. pipiens forms and hybrids in all studied sites. Of all the tested larvae of Cx. pipiens, 33.5% were identified as pipiens, 30.8% were identified as molestus, and 35.6% were identified as hybrids. The molestus and hybrid forms were positively correlated with urban habitats and belowground sites while the pipiens form was positively correlated with rural habitats and aboveground sites. Autogeny was expressed in all types of habitats and breeding sites. By contrast with the microsatellite CQ11, the two molecular markers, ace-2 and cytb, did not allow differentiation between the Cx. pipiens forms. Conclusions Our study shows the ubiquitous distribution and the plasticity of the different forms of Cx. pipiens in a wide range of ecological conditions. It suggests that the behavioral traits assigned to the forms of Cx. pipiens seem to be more flexible than previously assumed. Our analysis also proves that the microsatellite CQ11 remains an efficient tool for distinguishing between Cx. pipiens forms

    Additional file 5: Table S5. of Ecophysiological characterization and molecular differentiation of Culex pipiens forms (Diptera: Culicidae) in Tunisia

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    Results of the relationship between habitat type and breeding site type and the percentage of autogeny of Cx. pipiens mosquitoes, based on a Generalized Linear Model with Poisson distribution. (PDF 88 kb

    Author Correction: Culex pipiens crossing type diversity is governed by an amplified and polymorphic operon of Wolbachia

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    International audienceCorrection to: Nature Communications https://doi.org/10.1038/s41467-017-02749-w, published online 22 January 201

    Stable coexistence of incompatible Wolbachia along a narrow contact zone in mosquito field populations

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    International audienceIn arthropods, the intracellular bacteria Wolbachia often induce cytoplasmic incompatibility (CI) between sperm and egg, which causes conditional embryonic death and promotes the spatial spread of Wolbachia infections into host populations. The ability of Wolbachia to spread in natural populations through CI has attracted attention for using these bacteria in vector-borne disease control. The dynamics of incompatible Wolbachia infections have been deeply investigated theoretically, whereas in natural populations, there are only few examples described, especially among incompatible infected hosts. Here, we have surveyed the distribution of two molecular Wolbachia strains (wPip11 and wPip31) infecting the mosquito Culex pipiens in Tunisia. We delineated a clear spatial structure of both infections, with a sharp contact zone separating their distribution areas. Crossing experiments with isofemale lines from different localities showed three crossing types: wPip11-infected males always sterilize wPip31-infected females; however, while most wPip31-infected males were compatible with wPip11-infected females, a few completely sterilize them. The wPip11 strain was thus expected to spread, but temporal dynamics over 7 years of monitoring shows the stability of the contact zone. We examined which factors may contribute to the observed stability, both theoretically and empirically. Population cage experiments, field samples and modelling did not support significant impacts of local adaptation or assortative mating on the stability of wPip infection structure. By contrast, low dispersal probability and metapopulation dynamics in the host Cx. pipiens probably play major roles. This study highlights the need of understanding CI dynamics in natural populations to design effective and sustainable Wolbachia-based control strategies
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