117 research outputs found

    Déconvolution aveugle en microscopie de fluorescence 3D

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    National audienceDans ce papier, nous proposons une méthode de déconvolution aveugle estimant la fonction de flou (PSF) et l'image nette en microscopie de fluorescence 3D. L'idée est d'utiliser un modèle paramétré par la fonction pupille pour la PSF en décomposant le module et la phase de la partie aberration sur la base de Zernike. Les résultats tant sur des simulations que sur des données expérimentales montrent la supériorité de notre méthode comparée à l'état de l'art

    New data on the Silurian-Devonian paleontology and biostratigraphy of Bolivia

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    P. 269-314In order to precisely establish the bio- and chronostratigraphic position of several levels of the Silurian–Devonian succession of Bolivia, with respect to the International Time Scale, additional Silurian and Devonian localities belonging to the Eastern Cordillera and the Interandean Zone areas have been recently revised and sampled, both for macrofossils and palynomorphs. Specifically, the localities are Ñuñumayani, and Muruhuta from the late Silurian–early Devonian time interval. Correlations with other fossiliferous localities are discussed, namely Huacallani and Rumicorral.S

    Ciliary Beating Recovery in Deficient Human Airway Epithelial Cells after Lentivirus Ex Vivo Gene Therapy

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    Primary Ciliary Dyskinesia is a heterogeneous genetic disease that is characterized by cilia dysfunction of the epithelial cells lining the respiratory tracts, resulting in recurrent respiratory tract infections. Despite lifelong physiological therapy and antibiotics, the lungs of affected patients are progressively destroyed, leading to respiratory insufficiency. Recessive mutations in Dynein Axonemal Intermediate chain type 1 (DNAI1) gene have been described in 10% of cases of Primary Ciliary Dyskinesia. Our goal was to restore normal ciliary beating in DNAI1–deficient human airway epithelial cells. A lentiviral vector based on Simian Immunodeficiency Virus pseudotyped with Vesicular Stomatitis Virus Glycoprotein was used to transduce cultured human airway epithelial cells with a cDNA of DNAI1 driven by the Elongation Factor 1 promoter. Transcription and translation of the transduced gene were tested by RT–PCR and western blot, respectively. Human airway epithelial cells that were DNAI1–deficient due to compound heterozygous mutations, and consequently had immotile cilia and no outer dynein arm, were transduced by the lentivirus. Cilia beating was recorded and electron microscopy of the cilia was performed. Transcription and translation of the transduced DNAI1 gene were detected in human cells treated with the lentivirus. In addition, immotile cilia recovered a normal beat and outer dynein arms reappeared. We demonstrated that it is possible to obtain a normalization of ciliary beat frequency of deficient human airway epithelial cells by using a lentivirus to transduce cells with the therapeutic gene. This preliminary step constitutes a conceptual proof that is indispensable in the perspective of Primary Ciliary Dyskinesia's in vivo gene therapy. This is the first time that recovery of cilia beating is demonstrated in this disease

    Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

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    A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

    stairs and fire

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    Blind deconvolution of 3D data in wide field fluorescence microscopy

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    International audienceIn this paper we propose a blind deconvolution algorithm for wide field fluorescence microscopy. The 3D PSF is modeled after a parametrized pupil function. The PSF parameters are estimated jointly with the object in a maximum a posteriori framework. We illustrate the performances of our algorithm on experimental data and show significant resolution improvement notably along the depth. Quantitative measurements on images of calibration beads demonstrate the benefits of blind deconvolution both in terms of contrast and resolution compared to non-blind deconvolution using a theoretical PSF

    Induction de la cardioprotection par le diazoxide (études en temps réel sur un modèle cellulaire)

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    Une protection contre les lésions dues à une ischmie-reperfusion peut être induite par le diazoxide, un ouvreur de canaux potassiques ATP-dépendants (Katp). Le diazoxide est aussi connu pour inhiber la succinate déshydrogénase (SDH), enzyme de la chaîne respiratoire et du cycle de Krebs. Pour mieux comprendre les mécanismes en jeu, nous avons caractérisé la lignée cellulaire d'origine cardiaque HL-1-NB, adaptée à l'utilisation de techniques optiques, pour suivre en temps réel plusieurs paramètres cellulaires. Sur ce modèle nous avons montré que le diazoxide n'induit pas l'ouverture des canaux KATP, ni sarcolemmaux, ni mitochondriaux, dans des conditions qui induisent pourtant une protection. Nos résultats sont en faveur d'un rôle clé de l'inhibition de la SDH dans l'induction de la protection. Ils suggèrent par ailleurs que le diazoxide pourrait avoir, par une action sur les canaux KATP sarcolemmaux, indépendamment de leur ouverture, un effet métabolique compartimentéLYON1-BU.Sciences (692662101) / SudocSudocFranceF
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