The Serrasalmidae (Pisces, Characoidei) from the Serra do Roncador, Mato Grosso, Brasil

Systematic account of the Fishes of the family Serrasalmidae (Characoidei, Cypriniformes) from the upper drainages of the Rios Araguaia and Xingu in Brazil, collected in 1968 by R.H. LOWE-McCONNELL, R. MILLS and J. GREEN. Eight species of the subfamily Myleinae are described, namely Myleus rubripinnis, M. schomburgki and a third unnamed species (that might be new to science), the rare Utiaritichthys sennaebragae and Acnodon normani (first collecting since the description of the types) and 3 Metynnis-species. Four species of the subfamily Serrasalminae are described: Serrasalmus striolatus ssp. (that has been compared with topotypical specimens of S. striolatus), S. humeralis (represented by topotypical individuals, which permitted an extended definition of the species), a geographic form of the common S. rhombeus and S. gibbus, an almost forgotten species that is tentatively restored

Contribution à la systématique des Prochilodus boliviens (Pisces, Characiformes, Prochilodidae)

Quatre-vingt-huit spécimens du genre néotropical de poissons characiformes #Prochilodus Agassiz, récoltés en Bolivie, ont été étudiés. L'évaluation de caractères taxonomiques classiques ainsi que la structure des dents labiales et une analyse multivariée (analyse en composantes principales) ont permis de dégager un certain nombre de caractères discriminants, ce qui abouti à la reconnaissance de cinq espèces : #P. nigricans (rios Mamoré et Béni), #aff. nigricans (rio San Juanito), #labeo n. sp. (Andes), #lineatus$ (rio Pilcomayo) et une espèce non décrite du rio Itenez. Après quelques considérations sur les localités de récoltes, la taxonomie du genre et l'utilisation de l'analyse multivariée, les espèces sont décrites et discutées. Une clé de détermination artificielle est donnée à la fin. (Résumé d'auteur

Using Proximity and Tag Weights for Focused Retrieval in Structured Documents

International audienceFocused information retrieval is concerned with the retrieval of small units of information. In this context, the structure of the documents as well as the proximity among query terms have been found useful for improving retrieval effectiveness. In this article, we propose an approach combining the proximity of the terms and the tags which mark these terms. Our approach is based on a Fetch and Browse method where the fetch step is performed with BM25 and the browse step with a structure enhanced proximity model. In this way, the ranking of a document depends not only upon the existence of the query terms within the document but also upon the tags which mark these terms. Thus, the document tends to be highly relevant when query terms are close together and are emphasized by tags. The evaluation of this model on a large XML structured collection provided by the INEX 2010 XML IR evaluation campaign shows that the use of term proximity and structure improves the retrieval effectiveness of BM25 in the context of focused information retrieval

UJM at INEX 2009 Ad Hoc track

7 pagesInternational audienceThis paper1 presents our participation to the INEX 2009 Ad- Hoc track. We have experimented the tuning of various parameters using a ”training” collection (i.e. INEX 2008) quite different than the ”testing” collection used for 2009 INEX Ad-Hoc track. Several parameters have been studied for article retrieval as well as for element retrieval, especially the two main BM25 weighting function parameters: b and k1

Blurred constitutive laws and bipotential convex covers

In many practical situations, incertitudes affect the mechanical behaviour that is given by a family of graphs instead of a single one. In this paper, we show how the bipotential method is able to capture such blurred constitutive laws, using bipotential convex covers