63 research outputs found

    SynthÚse de la journée

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    Il va ĂȘtre difficile de faire une synthĂšse courte car cette journĂ©e a Ă©tĂ© trĂšs riche et il s’y est dit Ă©normĂ©ment de choses. Je vous propose donc de balayer toutes ces idĂ©es sous deux formes. D’abord, sous la forme de constats. Je ne suis pas un spĂ©cialiste des bibliothĂšques, je suis plutĂŽt du cĂŽtĂ© de la formation, de l’autoformation et j’ai donc notĂ© un certain nombre de remarques qui m’ont frappĂ© et que je vais vous Ă©noncer. Ensuite, sous formes de questions que j’essaierai de synthĂ©tiser p..

    Estimation de paramÚtres pour des processus autorégressifs à bifurcation

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    Les processus autorĂ©gressifs Ă  bifurcation (BAR) ont Ă©tĂ© au centre de nombreux travaux de recherche ces derniĂšres annĂ©es. Ces processus, qui sont l'adaptation Ă  un arbre binaire des processus autorĂ©gressifs, sont en effet d'intĂ©rĂȘt en biologie puisque la structure de l'arbre binaire permet une analogie aisĂ©e avec la division cellulaire. L'objectif de cette thĂšse est l'estimation les paramĂštres de variantes de ces processus autorĂ©gressifs Ă  bifurcation, Ă  savoir les processus BAR Ă  valeurs entiĂšres et les processus BAR Ă  coefficients alĂ©atoires. Dans un premier temps, nous nous intĂ©ressons aux processus BAR Ă  valeurs entiĂšres. Nous Ă©tablissons, via une approche martingale, la convergence presque sĂ»re des estimateurs des moindres carrĂ©s pondĂ©rĂ©s considĂ©rĂ©s, ainsi qu'une vitesse de convergence de ces estimateurs, une loi forte quadratique et leur comportement asymptotiquement normal. Dans un second temps, on Ă©tudie les processus BAR Ă  coefficients alĂ©atoires. Cette Ă©tude permet d'Ă©tendre le concept de processus autorĂ©gressifs Ă  bifurcation en gĂ©nĂ©ralisant le cĂŽtĂ© alĂ©atoire de l'Ă©volution. Nous Ă©tablissons les mĂȘmes rĂ©sultats asymptotiques que pour la premiĂšre Ă©tude. Enfin, nous concluons cette thĂšse par une autre approche des processus BAR Ă  coefficients alĂ©atoires oĂč l'on ne pondĂšre plus nos estimateurs des moindres carrĂ©s en tirant parti du thĂ©orĂšme de Rademacher-Menchov.Bifurcating autoregressive (BAR) processes have been widely investigated this past few years. Those processes, which are an adjustment of autoregressive processes to a binary tree structure, are indeed of interest concerning biology since the binary tree structure allows an easy analogy with cell division. The aim of this thesis is to estimate the parameters of some variations of those BAR processes, namely the integer-valued BAR processes and the random coefficients BAR processes. First, we will have a look to integer-valued BAR processes. We establish, via a martingale approach, the almost sure convergence of the weighted least squares estimators of interest, together with a rate of convergence, a quadratic strong law and their asymptotic normality. Secondly, we study the random coefficients BAR processes. The study allows to extend the principle of bifurcating autoregressive processes by enlarging the randomness of the evolution. We establish the same asymptotic results as for the first study. Finally, we conclude this thesis with an other approach of random coefficient BAR processes where we do not weight our least squares estimators any more by making good use of the Rademacher-Menchov theorem.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

    BibliothĂšques et autoformation

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    Dans un univers oĂč les nouvelles technologies Ă©voluent constamment et oĂč l'individu est rĂ©guliĂšrement amenĂ© Ă  se recycler dans sa carriĂšre professionnelle ou Ă  maĂźtriser les outils de dĂ©veloppement personnel, la bibliothĂšque est aujourd'hui le lieu d'expression d'une demande nouvelle en autoformation. Cette demande, dĂ©pendante pour partie de l'offre de la bibliothĂšque et du niveau de formation de l'usager, remet Ă©galement en question le rĂŽle des bibliothĂ©caires et de leur mĂ©diation. Reprenant les actes du colloque organisĂ© Ă  la BibliothĂšque publique d'information en dĂ©cembre 2005, ainsi que le rapport de l'enquĂȘte rĂ©alisĂ©e par le service Études et recherche de la Bpi sur l'espace Autoformation de la Bpi, cet ouvrage se veut un outil de rĂ©flexion pour les professionnels des bibliothĂšques. Reformulant les questions auxquelles les bibliothĂ©caires sont confrontĂ©es dans leur pratique quotidienne, s'appuyant sur leurs expĂ©riences et sur l'analyse thĂ©orique de chercheurs en sciences de l'information, il tente d'ouvrir de nouvelles pistes de travail pour Ă©tablir Ă  l'avenir, peut-ĂȘtre une « charte de l'autoformation en bibliothĂšque »

    Micro-trottoir

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    Ce micro-trottoir a Ă©tĂ© rĂ©alisĂ© aux alentours du Centre Pompidou en juin 2005. L’équipe « Autoformation » de la BibliothĂšque publique d’information, avec l’aide d’un preneur de son, a posĂ© la question : « Si je vous dis autoformation, Ă  quoi cela vous fait-il penser ? » Les rĂ©ponses Ă  ces questions, dont nous vous proposons ici une sĂ©lection, ont Ă©tĂ© diffusĂ©es en toile de fond lors du colloque. Nous remercions celles et ceux qui ont acceptĂ© de prendre le temps de nous rĂ©pondre. « Se former so..

    Conclusion

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    L’autoformation Ă  la Bpi, lorsqu’elle est Ă©voquĂ©e par nos usagers, est dotĂ©e de significations diffĂ©rentes. Si cette notion se rĂ©fĂšre parfois pour eux Ă  une façon d’apprendre spĂ©cifique, reposant sur un projet autogĂ©rĂ©, l’autoformation renvoie Ă©galement Ă  une norme d’usage qui consiste Ă  se dĂ©brouiller seul. L’autonomie est alors vĂ©cue comme un point de passage obligĂ©, pour accĂ©der Ă  des ressources difficiles d’accĂšs et pourtant nĂ©cessaires. Nos usagers ressentent une certaine gratitude Ă  l’é..

    Genomic Exploration of the Hemiascomycetous Yeasts: 1. A set of yeast species for molecular evolution studies11Sequences and annotations are accessible at: GĂ©noscope (http://www.genoscope.cns.fr), FEBS Letters Website (http://www.elsevier.nl/febs/show/), Bordeaux (http://cbi.genopole-bordeaux.fr/Genolevures) and were deposited into the EMBL database (accession number from AL392203 to AL441602).

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    AbstractThe identification of molecular evolutionary mechanisms in eukaryotes is approached by a comparative genomics study of a homogeneous group of species classified as Hemiascomycetes. This group includes Saccharomyces cerevisiae, the first eukaryotic genome entirely sequenced, back in 1996. A random sequencing analysis has been performed on 13 different species sharing a small genome size and a low frequency of introns. Detailed information is provided in the 20 following papers. Additional tables available on websites describe the ca. 20 000 newly identified genes. This wealth of data, so far unique among eukaryotes, allowed us to examine the conservation of chromosome maps, to identify the ‘yeast-specific’ genes, and to review the distribution of gene families into functional classes. This project conducted by a network of seven French laboratories has been designated ‘GĂ©nolevures’

    Genomic Exploration of the Hemiascomycetous Yeasts: 19. Ascomycetes-specific genes

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    AbstractComparisons of the 6213 predicted Saccharomyces cerevisiae open reading frame (ORF) products with sequences from organisms of other biological phyla differentiate genes commonly conserved in evolution from ‘maverick’ genes which have no homologue in phyla other than the Ascomycetes. We show that a majority of the ‘maverick’ genes have homologues among other yeast species and thus define a set of 1892 genes that, from sequence comparisons, appear ‘Ascomycetes-specific’. We estimate, retrospectively, that the S. cerevisiae genome contains 5651 actual protein-coding genes, 50 of which were identified for the first time in this work, and that the present public databases contain 612 predicted ORFs that are not real genes. Interestingly, the sequences of the ‘Ascomycetes-specific’ genes tend to diverge more rapidly in evolution than that of other genes. Half of the ‘Ascomycetes-specific’ genes are functionally characterized in S. cerevisiae, and a few functional categories are over-represented in them

    Evolving and sustaining ocean best practices and standards for the next decade

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    The oceans play a key role in global issues such as climate change, food security, and human health. Given their vast dimensions and internal complexity, efficient monitoring and predicting of the planet’s ocean must be a collaborative effort of both regional and global scale. A first and foremost requirement for such collaborative ocean observing is the need to follow well-defined and reproducible methods across activities: from strategies for structuring observing systems, sensor deployment and usage, and the generation of data and information products, to ethical and governance aspects when executing ocean observing. To meet the urgent, planet-wide challenges we face, methods across all aspects of ocean observing should be broadly adopted by the ocean community and, where appropriate, should evolve into “Ocean Best Practices.” While many groups have created best practices, they are scattered across the Web or buried in local repositories and many have yet to be digitized. To reduce this fragmentation, we introduce a new open access, permanent, digital repository of best practices documentation (oceanbestpractices.org) that is part of the Ocean Best Practices System (OBPS). The new OBPS provides an opportunity space for the centralized and coordinated improvement of ocean observing methods. The OBPS repository employs user-friendly software to significantly improve discovery and access to methods. The software includes advanced semantic technologies for search capabilities to enhance repository operations. In addition to the repository, the OBPS also includes a peer reviewed journal research topic, a forum for community discussion and a training activity for use of best practices. Together, these components serve to realize a core objective of the OBPS, which is to enable the ocean community to create superior methods for every activity in ocean observing from research to operations to applications that are agreed upon and broadly adopted across communities. Using selected ocean observing examples, we show how the OBPS supports this objective. This paper lays out a future vision of ocean best practices and how OBPS will contribute to improving ocean observing in the decade to come

    Des hommes et des objets - Esquisses pour une sociologie avec objets

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    This dissertation defines the relations between men and the objects, and sketches a sociology taking objects into account. The core hypothesis of this work, inspired by post-phenomenological approaches, is that objects embody social relations; that they are compulsory mediators of relational processes between human beings.The author starts from the fact that objects are quite absent in social sciences topics. To study the relations to objects, he proposes to consider them as pieces of knowledge, to determine what type of knowledge they are, and how this knowledge is built into man's brain. This work relies on field researches on how communication instruments are used at work. The first finding is that “utility” relationship is a social relationship. These findings are then confronted with approaches of objects appearing in the writings of several authors from various disciplinary fields: technology, semiology, sociology, psychology. This confrontation reveals the existence of different registers of relations to objects, corresponding to different social processes.Then, the author proposes an organisation of these relations to objects into a two-levels coherent system of relational processes: basic affective-cognitive relations, and instrumental relations, most of which being of “conventional” order. He suggests at the end what could be a “sociology encompassing objects”.Cette thĂšse dĂ©finit les relations aux objets et esquisse une sociologie qui prendrait en compte les objets. L'hypothĂšse centrale de ce travail, inspirĂ© des approches post-phĂ©nomĂ©nologiques, c'est que les objets incarnent les relations sociales ; qu'ils sont les mĂ©diateurs obligĂ©s des processus relationnels entre les ĂȘtres humains.L'auteur part du constat que les objets sont pratiquement absents des prĂ©occupations des sciences sociales. Pour Ă©tudier les relations aux objets, il propose de les considĂ©rer comme des « connaissances », puis de chercher Ă  comprendre quelles sont ces connaissances et comment elles se construisent. Ce travail est menĂ© dans un premier temps Ă  partir de l'Ă©tude de diffĂ©rentes formes d'utilisation des instruments de communication. Il permet de montrer que la relation d'utilitĂ© est une relation sociale. Les conclusions de ce travail sont ensuite confrontĂ©es Ă  l'approche des objets apparaissant dans les Ă©crits de plusieurs auteurs dans diffĂ©rents champs disciplinaires : technologie, sĂ©miologie, sociologie, psychologie. Cette confrontation permet de dĂ©gager l'existence de plusieurs registres de relations aux objets, correspondant Ă  divers registres de relations sociales.L'auteur propose ensuite l'organisation de ces relations aux objets en un systĂšme cohĂ©rent de processus relationnels comportant deux niveaux : les relations affectivo-cognitives fondamentales, et les relations instrumentales, dont la plupart sont d'ordre conventionnel. Il suggĂšre pour finir ce que pourrait ĂȘtre une « sociologie avec objets »
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