OCB: A Generic Benchmark to Evaluate the Performances of Object-Oriented Database Systems

International audienceWe present in this paper a generic object-oriented benchmark (the Object Clustering Benchmark) that has been designed to evaluate the performances of clustering policies in object-oriented databases. OCB is generic because its sample database may be customized to fit the databases introduced by the main existing benchmarks (e.g., OO1). OCB's current form is clustering-oriented because of its clustering-oriented workload, but it can be easily adapted to other purposes. Lastly, OCB's code is compact and easily portable. OCB has been implemented in a real system (Texas, running on a Sun workstation), in order to test a specific clustering policy called DSTC. A few results concerning this test are presented

Connaître les techniques de conservation des documents patrimoniaux

Fiche pratique portant sur les techniques de conservation : un ensemble de techniques visant à prévenir les atteintes à l\u27intégrité physique des documents, à les limiter et, en dernier lieu, à remédier aux dégradations qu\u27elles n\u27ont pu empêcher. La fiche évoque ainsi des techniques de prévention, de préservation et de restauration

De la convention à la conviction : Banārasīdās dans l'histoire de la pensée digambara sur l'absolu

The works of Banārasīdās (1586-1643), a Jain merchant and poet active in the region of Agra, is largely based on the thought of the Digambara philosopher Kundakunda (c. third century). The latter invited to search for the true nature of the self seen as the only reality from an absolute point of view (niścaya-naya). The layman condition of Banārasīdās obliged him to consider also his own religion from a conventional point of view (vyavahāra-naya). He was helped by his discovery of the spiritual scales prepared by the Jain doctrine and described in detail by Nemicandra (tenth century). It is rewarding to look at the articulation between the two points of view in a historical perspective, from the Samayasāra, the major work of Kundakunda, up to Śrīmad Rājacandra, a holy layman of the late nineteenth century, with a particular focus on the members of the Adhyātma movement whose Banārasīdās was one of the most successful instigators.L’œuvre de Banārasīdās (1586-1643), marchand et poète jaina actif dans la région d’Agra, s’appuie sur la pensée du maître digambara Kundakunda (c. IIIe s. de notre ère) pour chanter la véritable nature du soi, intrinsèquement pur, réalité suprême d’un point de vue absolu (niścaya-naya). La condition laïque de Banārasīdās l’oblige pourtant à envisager aussi la religion d’un point de vue conventionnel (vyavahāra-naya), aidé en cela par des échelles de progression spirituelle ménagées par la doctrine jaina et décrites notamment par Nemicandra (Xe siècle). Il est intéressant de suivre en diachronie l’articulation entre les deux points de vue, depuis le Samayasāra, ouvrage fondateur de Kundakunda, jusqu’à Śrīmad Rājacandra, un saint personnage de la fin du XIXe siècle, en s’attardant particulièrement sur les membres du mouvement Adhyātma dont Banārasīdās a été l’un des plus brillants promoteurs

From solar to stellar corona: the role of wind, rotation and magnetism

Observations of surface magnetic fields are now within reach for many stellar types thanks to the development of Zeeman-Doppler Imaging. These observations are extremely useful for constraining rotational evolution models of stars, as well as for characterizing the generation of magnetic field. We recently demonstrated that the impact of coronal magnetic field topology on the rotational braking of a star can be parametrized with a scalar parameter: the open magnetic flux. However, without running costly numerical simulations of the stellar wind, reconstructing the coronal structure of the large scale magnetic field is not trivial. An alternative -broadly used in solar physics- is to extrapolate the surface magnetic field assuming a potential field in the corona, to describe the opening of the field lines by the magnetized wind. This technique relies on the definition of a so-called source surface radius, which is often fixed to the canonical value of 2.5Rsun. However this value likely varies from star to star. To resolve this issue, we use our extended set of 2.5D wind simulations published in 2015, to provide a criteria for the opening of field lines as well as a simple tool to assess the source surface radius and the open magnetic flux. This allows us to derive the magnetic torque applied to the star by the wind from any spectropolarimetric observation. We conclude by discussing some estimations of spin-down time scales made using our technique, and compare them to observational requirements.Comment: Accepted for publication in the Astrophysical Journa

Plant traits correlated with generation time directly affect inbreeding depression and mating system and indirectly genetic structure

<p>Abstract</p> <p>Background</p> <p>Understanding the mechanisms that control species genetic structure has always been a major objective in evolutionary studies. The association between genetic structure and species attributes has received special attention. As species attributes are highly taxonomically constrained, phylogenetically controlled methods are necessary to infer causal relationships. In plants, a previous study controlling for phylogenetic signal has demonstrated that Wright's <it>F</it>_ST, a measure of genetic differentiation among populations, is best predicted by the mating system (outcrossing, mixed-mating or selfing) and that plant traits such as perenniality and growth form have only an indirect influence on <it>F</it>_STvia their association with the mating system. The objective of this study is to further outline the determinants of plant genetic structure by distinguishing the effects of mating system on gene flow and on genetic drift. The association of biparental inbreeding and inbreeding depression with population genetic structure, mating system and plant traits are also investigated.</p> <p>Results</p> <p>Based on data from 263 plant species for which estimates of <it>F</it>_ST, inbreeding (<it>F</it>_IS) and outcrossing rate (<it>t</it>_m) are available, we confirm that mating system is the main influencing factor of <it>F</it>_ST. Moreover, using an alternative measure of <it>F</it>_STunaffected by the impact of inbreeding on effective population size, we show that the influence of <it>t</it>_mon <it>F</it>_STis due to its impact on gene flow (reduced pollen flow under selfing) and on genetic drift (higher drift under selfing due to inbreeding). Plant traits, in particular perenniality, influence <it>F</it>_STmostly via their effect on the mating system but also via their association with the magnitude of selection against inbred individuals: the mean inbreeding depression increases from short-lived herbaceous to long-lived herbaceous and then to woody species. The influence of perenniality on mating system does not seem to be related to differences in stature, as proposed earlier, but rather to differences in generation time.</p> <p>Conclusion</p> <p>Plant traits correlated with generation time affect both inbreeding depression and mating system. These in turn modify genetic drift and gene flow and ultimately genetic structure.</p

Gestion des fonds de manuscrits indiens dans les bibliothèques françaises

Les manuscrits en provenance de l’Asie du Sud sont entrés dans les collections des bibliothèques françaises dès le début du 18ème siècle. Leur nombre important, leur richesse et leur fragilité sont autant d’impératifs de pouvoir les gérer. Ce mémoire veut donner des éléments de description matérielle et des particularités pour une conservation adéquate. Il dresse un historique des collections de manuscrits indiens en France en signalant l’existence de fonds particuliers. Les particularités pour le catalogage de ces manuscrits sont données, tant d’un point de vue de la codicologie que de la technologie. Les différents moyens de valoriser ce type de patrimoine écrit auprès du grand public sont évoqués, de même que les éléments propices à leur exploitation scientifique