The Statistical Performance of Collaborative Inference

The statistical analysis of massive and complex data sets will require the development of algorithms that depend on distributed computing and collaborative inference. Inspired by this, we propose a collaborative framework that aims to estimate the unknown mean $\theta$ of a random variable $X$. In the model we present, a certain number of calculation units, distributed across a communication network represented by a graph, participate in the estimation of $\theta$ by sequentially receiving independent data from $X$ while exchanging messages via a stochastic matrix $A$ defined over the graph. We give precise conditions on the matrix $A$ under which the statistical precision of the individual units is comparable to that of a (gold standard) virtual centralized estimate, even though each unit does not have access to all of the data. We show in particular the fundamental role played by both the non-trivial eigenvalues of $A$ and the Ramanujan class of expander graphs, which provide remarkable performance for moderate algorithmic cost

Übersicht über die Ergebnisse eines Forschungsprojekts zur schulischen Integration von Kindern mit einer geistigen Behinderung

Cet article présente une synthèse des résultats d’un projet de recherche qui évalue les effets de l’intégration scolaire d’élèves ayant une déficience intellectuelle sur leurs progrès et ceux de leurs pairs au développement typique et qui examine les attitudes des enseignants. Ce projet mené à l’Institut de Pédagogie Curative de l’Université de Fribourg a été primé en mai 2014 par le prix de la Conférence suisse pour la coordination de la recherche en éducation (CORECHED).Dieser Artikel bietet eine Übersicht über die Ergebnisse eines Forschungsprojekts, das vom Heilpädagogischen Institut der Universität Freiburg realisiert und im Mai 2014 mit dem Preis der Schweizerischen Koordinationskonferenz Bildungsforschung (CORECHED) ausgezeichnet wurde. Mit diesem Projekt wurden die Auswirkungen der schulischen Integration von Kindern mit einer geistigen Behinderung auf die Entwicklung dieser Kinder und ihrer nichtbehinderten Mitschülerinnen und Mitschüler sowie die Einstellungen der Lehrpersonen untersucht

Synthèse des résultats d’un projet de recherche sur l’intégration scolaire d’élèves ayant une déficience intellectuelle

Cet article présente une synthèse des résultats d’un projet de recherche qui évalue les effets de l’intégration scolaire d’élèves ayant une déficience intellectuelle sur leurs progrès et ceux de leurs pairs au développement typique et qui examine les attitudes des enseignants. Ce projet mené à l’Institut de Pédagogie Curative de l’Université de Fribourg a été primé en mai 2014 par le prix de la Conférence suisse pour la coordination de la recherche en éducation (CORECHED)Dieser Artikel bietet eine Übersicht über die Ergebnisse eines Forschungsprojekts, das vom Heilpädagogischen Institut der Universität Freiburg realisiert und im Mai 2014 mit dem Preis der Schweizerischen Koordinationskonferenz Bildungsforschung (CORECHED) ausgezeichnet wurde. Mit diesem Projekt wurden die Auswirkungen der schulischen Integration von Kindern mit einer geistigen Behinderung auf die Entwicklung dieser Kinder und ihrer nichtbehinderten Mitschülerinnen und Mitschüler sowie die Einstellungen der Lehrpersonen untersucht

Trophic groups and modules: two levels of group detection in food webs

Within food webs, species can be partitioned into groups according to various criteria. Two notions have received particular attention: trophic groups, which have been used for decades in the ecological literature, and more recently, modules. The relationship between these two group definitions remains unknown in empirical food webs because they have so far been studied separately. While recent developments in network theory have led to efficient methods for detecting modules in food webs, the determination of trophic groups (sets of species that are functionally similar) is based on subjective expert knowledge. Here, we develop a novel algorithm for trophic group detection. We apply this method to several well-resolved empirical food webs, and show that aggregation into trophic groups allows the simplification of food webs while preserving their information content. Furthermore, we reveal a 2-level hierarchical structure where modules partition food webs into large bottom-top trophic pathways whereas trophic groups further partition these pathways into sets of species with similar trophic connections. Bringing together trophic groups and modules provides new perspectives to the study of dynamical and functional consequences of food-web structure, bridging topological analysis and dynamical systems. Trophic groups have a clear ecological meaning in terms of trophic similarity, and are found to provide a trade-off between network complexity and information loss

La banque de données Médoc mécanisation de la France xixe-xxe siècles

Définition d'une problématique : la mécanisation envisagée comme l'un des processus centraux de l'industrialisation La mécanisation est l'un des aspects clés pour comprendre le processus d'ensemble de l'industrialisation. Cette notion recouvre en réalité deux dynamiques à la fois conjointes et distinctes. D'une part, la mécanisation comme substitution toujours plus étendue du machinisme au travail manuel dans la sphère de la production. De l'autre, comme extension continue des applications de..

Isolation and characterization of novel glycoproteins from fish epidermal mucus: correlation between their pore-forming properties and their antibacterial activities

AbstractIn fish, a layer of mucus covers the external body surface contributing therefore, among other important biological functions, to the defense system of fish. The prevention of colonization by aquatic parasites, bacteria and fungi is mediated both by immune system compounds (IgM, lysozyme, etc.) and by antibacterial peptides and polypeptides. We have recently shown that only the hydrophobic components of crude epidermal mucus of fresh water and sea water fish exhibit strong pore-forming properties, which were well correlated with antibacterial activity [N. Ebran, S. Julien, N. Orange, P. Saglio, C. Lemaitre, G. Molle, Comp. Biochem. Physiol. 122 (1999)]. Here, we have isolated novel glycosylated proteins from the hydrophobic supernatant of tench (Tinca tinca), eel (Anguilla anguilla) and rainbow trout (Oncorhynchus mykiss) mucus. The study of their secondary structure was performed by circular dichroism and revealed structures in random coil and α-helix in the same proportions. When reconstituted in planar lipid bilayer, they induced the formation of ion channels. This pore-forming activity was well correlated with a strong antibacterial activity (minimal inhibitory concentration<1 μM for the three proteins) against both Gram-negative and Gram-positive bacteria. Our results suggest that fish secrete antibacterial glycoproteins able to kill bacteria by forming large pores (several hundreds to thousands of pS) in the target membrane

On Linear Cryptanalysis with Many Linear Approximations

In this paper we present a theoretical framework to quantify the information brought by several linear approximations of a block-cipher without putting any restriction on these approximations. We quantify here the entropy of the key given the plaintext-ciphertext pairs statistics which is a much more accurate measure than the ones studied earlier. The techniques which are developed here apply to various ways of performing the linear attack and can also been used to measure the entropy of the key for other statistical attacks. Moreover, we present a realistic attack on the full DES with a time complexity of $2^{48}$ for $2^{41}$ pairs what is a big improvement comparing to Matsui\u27s algorithm 2 ($2^{51.9}$)