49,826 research outputs found
Witness sets
Given a set C of binary n-tuples and c in C, how many bits of c suffice to
distinguish it from the other elements in C? We shed new light on this old
combinatorial problem and improve on previously known bounds.Comment: Coding theory and applications, Espagne (2008
Identification of the het-r vegetative incompatibility gene of Podospora anserina as a member of the fast evolving HNWD gene family
In fungi, vegetative incompatibility is a conspecific non-self recognition mechanism that restricts formation of viable heterokaryons when incompatible alleles of specific het loci interact. In Podospora anserina, three non-allelic incompatibility systems have been genetically defined involving interactions between het-c and het-d, het-c and het-e, het-r and het-v. het-d and het-e are paralogues belonging to the HNWD gene family that encode proteins of the STAND class. HET-D and HET-E proteins comprise an N-terminal HET effector domain, a central GTP binding site and a C-terminal WD repeat domain constituted of tandem repeats of highly conserved WD40 repeat units that define the specificity of alleles during incompatibility. The WD40 repeat units of the members of this HNWD family are undergoing concerted evolution. By combining genetic analysis and gain of function experiments, we demonstrate that an additional member of this family, HNWD2, corresponds to the het-r non-allelic incompatibility gene. As for het-d and het-e, allele specificity at the het-r locus is determined by the WD repeat domain. Natural isolates show allelic variation for het-
Transferts culturels et déclinaisons de la pédagogie européenne: le cas franco-romand au travers de l'itinéraire d'Alexandre Daguet (1816-1894)
Cette thĂšse vise Ă rĂ©Ă©valuer la circulation des savoirs pĂ©dagogiques dans lâespace francosuisse. MĂ©thodologiquement, nous nous proposons dâinsister sur les modalitĂ©s de passage de ces savoirs dâun contexte culturel Ă lâautre, en Ă©tudiant les acteurs, les vecteurs, ainsi que les inĂ©vitables transformations sĂ©mantiques qui accompagnent nĂ©cessairement ces Ă©changes transnationaux. Cette recherche, articulĂ©e sous la forme dâune Gesellschaftsbiographie, prend pour guide le thĂ©oricien des idĂ©es Ă©ducatives, Alexandre Daguet (1816-1894). Il sâagit dâĂ©clairer son rĂŽle de mĂ©diateur privilĂ©giĂ© dans le transfert de savoirs pĂ©dagogiques entre la Suisse romande et la France, en Ă©tudiant notamment son rĂŽle de passeur via la revue LâĂducateur. Bien quâil ait dĂ©clinĂ© lâappel de Ferdinand Buisson Ă Ă©difier avec lui une « oeuvre internationale dâĂ©ducation », il nâen a pas pour le moins jouĂ© un rĂŽle de « courtier » dans la diffusion de savoirs spĂ©cifiques, vĂ©hiculĂ©s notamment par les proscrits français rĂ©fugiĂ©s en Suisse romande dĂšs 1852. Cette thĂšse permet de souligner comment les savoirs pĂ©dagogiques europĂ©ens, Ă©laborĂ©s de maniĂšre collective, sont diversement dĂ©clinĂ©s selon des spĂ©cificitĂ©s locales. Dans ce sens, il sâagit de montrer quâĂ mesure que les identitĂ©s se solidifient, les spĂ©cificitĂ©s nationales sont de plus en plus exaltĂ©es lors des Expositions universelles et les « exotismes » bientĂŽt dĂ©valorisĂ©s, voire mĂȘme dissimulĂ©s au profit dâun certain gĂ©nie national. Cette recherche souhaite donc contextualiser cette apparence trompeuse de SonderfĂ€lle, pour mettre davantage de relief dans la construction collective dâune pĂ©dagogie europĂ©enne mĂ©tissĂ©e. Mots clĂ©s : Alexandre Daguet, Suisse, transferts culturels, transformation sĂ©mantique, circulation des savoirs, histoire de la pĂ©dagogie, Ferdinand Buisson, TroisiĂšme RĂ©publiqueThis thesis seeks to reassess the way in which pedagogical knowledge circulated between France and Switzerland. In terms of method, we have chosen to focus on the way in which this knowledge passed from one cultural context to another by studying the related actors and vectors, as well as the inevitable semantic transformations which, of necessity, accompany transnational exchanges of this nature. The research takes the form of a Gesellschaftsbiographie, with a guide in the person of educational theorist Alexandre Daguet (1816-1894). It aims to shed light on his role as a key mediator in the transfer of pedagogical expertise between French-speaking Switzerland and France, with a special emphasis on the way he used the review LâĂducateur to take this knowledge across borders. Although Daguet turned down the proposal by Ferdinand Buisson to work with the latter to create an âinternational treatise on educationâ, he nevertheless acted as a âbrokerâ in the trade of specific knowledge, passed on in particular by the French political exiles that took refuge in French-speaking Switzerland from 1852 onwards. The thesis also highlights the way in which European pedagogical knowledge, developed collectively, was applied in a variety of ways depending on local particularities. The issue here is to show the way in which, as identities became more firmly established, distinctive national features were increasingly honoured at Universal Expositions, while the various forms of âexoticismâ soon fell out of favour, sometimes even to the point of being concealed in favour of national genius. This research therefore seeks to contextualise the deceptive semblance of SonderfĂ€lle and provide a clearer picture of the collective emergence of a multifaceted European pedagogy. Key words : Alexandre Daguet, Switzerland, cultural transfer, semantic transformation, circulation of knowledge, history of pedagogy, Ferdinand Buisson, French Third Republi
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