150 research outputs found

    Methodology for studying strain inhomogeneities in polycrystalline thin films during in situ thermal loading using coherent x-ray diffraction

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    International audienceCoherent x-ray diffraction is used to investigate the mechanical properties of a single grain within a polycrystalline thin film in situ during a thermal cycle. Both the experimental approach and finite element simulation are described. Coherent diffraction from a single grain has been monitored in situ at different temperatures. This experiment offers unique perspectives for the study of the mechanical properties of nano-objects

    CIB1 is an endogenous inhibitor of agonist-induced integrin αIIbβ3 activation

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    In response to agonist stimulation, the αIIbβ3 integrin on platelets is converted to an active conformation that binds fibrinogen and mediates platelet aggregation. This process contributes to both normal hemostasis and thrombosis. Activation of αIIbβ3 is believed to occur in part via engagement of the β3 cytoplasmic tail with talin; however, the role of the αIIb tail and its potential binding partners in regulating αIIbβ3 activation is less clear. We report that calcium and integrin binding protein 1 (CIB1), which interacts directly with the αIIb tail, is an endogenous inhibitor of αIIbβ3 activation; overexpression of CIB1 in megakaryocytes blocks agonist-induced αIIbβ3 activation, whereas reduction of endogenous CIB1 via RNA interference enhances activation. CIB1 appears to inhibit integrin activation by competing with talin for binding to αIIbβ3, thus providing a model for tightly controlled regulation of αIIbβ3 activation

    Anarchism, Utopianism and Hospitality: The Work of René Schérer

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    René Schérer (born 1922) is lamentably almost unknown to the Anglo-American world as his work has, as yet, not been translated . He is one of the main specialists of the French “utopian socialist”, Charles Fourier (1772-1837), and a major thinker in his own right. He is the author of more than twenty books and co-editor of the journal Chimères. Colleague and friend at Vincennes university (Paris 8) of Michel Foucault, Gilles Deleuze, Félix Guattari, Jacques Derrida, Jacques Rancière, Jean-François Lyotard, François Châletet, Alain Brossat, Georges Navet, Miguel Abensour, Pierre Macherey… he continues to host seminars at Paris 8 (now located at St. Denis). He is a living testimony to a radical past, and a continuing inspiration to a new generation of young thinkers. This article aims to convey the original specificity of his understanding of anarchism. By so doing, it will stress the importance of his work for any thinking concerned with a politicised resistance to social conformity and the supposed “state of things” today

    Human oocyte-derived methylation differences persist in the placenta revealing widespread transient imprinting

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    Thousands of regions in gametes have opposing methylation profiles that are largely resolved during the post-fertilization epigenetic reprogramming. However some specific sequences associated with imprinted loci survive this demethylation process. Here we present the data describing the fate of germline-derived methylation in humans. With the exception of a few known paternally methylated germline differentially methylated regions (DMRs) associated with known imprinted domains, we demonstrate that sperm-derived methylation is reprogrammed by the blastocyst stage of development. In contrast a large number of oocyte-derived methylation differences survive to the blastocyst stage and uniquely persist as transiently methylated DMRs only in the placenta. Furthermore, we demonstrate that this phenomenon is exclusive to primates, since no placenta-specific maternal methylation was observed in mouse. Utilizing single cell RNA-seq datasets from human preimplantation embryos we show that following embryonic genome activation the maternally methylated transient DMRs can orchestrate imprinted expression. However despite showing widespread imprinted expression of genes in placenta, allele-specific transcriptional profiling revealed that not all placenta-specific DMRs coordinate imprinted expression and that this maternal methylation may be absent in a minority of samples, suggestive of polymorphic imprinted methylation
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