598 research outputs found

    The BIC of a singular foliation defined by an abelian group of isometries

    Full text link
    We study the cohomology properties of the singular foliation \F determined by an action Φ ⁣:G×MM\Phi \colon G \times M\to M where the abelian Lie group GG preserves a riemannian metric on the compact manifold MM. More precisely, we prove that the basic intersection cohomology \lau{\IH}{*}{\per{p}}{\mf} is finite dimensional and verifies the Poincar\'e Duality. This duality includes two well-known situations: -- Poincar\'e Duality for basic cohomology (the action Φ\Phi is almost free). -- Poincar\'e Duality for intersection cohomology (the group GG is compact and connected)

    Top dimensional group of the basic intersection cohomology for singular riemannian foliations

    Full text link
    It is known that, for a regular riemannian foliation on a compact manifold, the properties of its basic cohomology (non-vanishing of the top-dimensional group and Poincar\'e Duality) and the tautness of the foliation are closely related. If we consider singular riemannian foliations, there is little or no relation between these properties. We present an example of a singular isometric flow for which the top dimensional basic cohomology group is non-trivial, but its basic cohomology does not satisfy the Poincar\'e Duality property. We recover this property in the basic intersection cohomology. It is not by chance that the top dimensional basic intersection cohomology groups of the example are isomorphic to either 0 or R\mathbb{R}. We prove in this Note that this holds for any singular riemannian foliation of a compact connected manifold. As a Corollary, we get that the tautness of the regular stratum of the singular riemannian foliation can be detected by the basic intersection cohomology.Comment: 11 pages. Accepted for publication in the Bulletin of the Polish Academy of Science

    Enhanced reproducibility of SADI web service workflows with Galaxy and Docke

    Get PDF
    Background: Semantic Web technologies have been widely applied in the life sciences, for example by data providers such as OpenLifeData and through web services frameworks such as SADI. The recently reported OpenLifeData2SADI project offers access to the vast OpenLifeData data store through SADI services. Findings: This article describes how to merge data retrieved from OpenLifeData2SADI with other SADI services using the Galaxy bioinformatics analysis platform, thus making this semantic data more amenable to complex analyses. This is demonstrated using a working example, which is made distributable and reproducible through a Docker image that includes SADI tools, along with the data and workflows that constitute the demonstration. Conclusions: The combination of Galaxy and Docker offers a solution for faithfully reproducing and sharing complex data retrieval and analysis workflows based on the SADI Semantic web service design patterns

    Finitness of the basic intersection cohomology of a Killing foliation

    Get PDF
    We prove that the basic intersection cohomology IHpˉ(M/F), {I H}^{^{*}}_{_{\bar{p}}}{(M/\mathcal{F})}, where F\mathcal{F} is the singular foliation determined by an isometric action of a Lie group GG on the compact manifold MM, is finite dimensional

    Tautness for riemannian foliations on non-compact manifolds

    Full text link
    For a riemannian foliation F\mathcal{F} on a closed manifold MM, it is known that F\mathcal{F} is taut (i.e. the leaves are minimal submanifolds) if and only if the (tautness) class defined by the mean curvature form κμ\kappa_\mu (relatively to a suitable riemannian metric μ\mu) is zero. In the transversally orientable case, tautness is equivalent to the non-vanishing of the top basic cohomology group Hn(M/F)H^{^{n}}(M/\mathcal{F}), where n = \codim \mathcal{F}. By the Poincar\'e Duality, this last condition is equivalent to the non-vanishing of the basic twisted cohomology group Hκμ0(M/F)H^{^{0}}_{_{\kappa_\mu}}(M/\mathcal{F}), when MM is oriented. When MM is not compact, the tautness class is not even defined in general. In this work, we recover the previous study and results for a particular case of riemannian foliations on non compact manifolds: the regular part of a singular riemannian foliation on a compact manifold (CERF).Comment: 18 page

    Equivariant intersection cohomology of the circle actions

    Full text link
    In this paper, we prove that the orbit space B and the Euler class of an action of the circle S^1 on X determine both the equivariant intersection cohomology of the pseudomanifold X and its localization. We also construct a spectral sequence converging to the equivariant intersection cohomology of X whose third term is described in terms of the intersection cohomology of B.Comment: Final version as accepted in RACSAM. The final publication is available at springerlink.com; Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales. Serie A. Matematicas, 201

    A Status Assessment of Perkinsiosis, Bonamiosis, and Mateiliosis in Commercial Marine Bivalves from Southern Brazil

    Get PDF
    14 páginas, 1 figura, 3 tablas.-- Simone Sühnel ... et al.The protozoans Perkinsus marinus, Perkinsus olseni, Bonamia ostreae, Bonamia exitiosa, and Marteilia refringens are responsible for some of the most detrimental diseases in the production of cultivated shellfish worldwide and are classified as notifiable diseases by the World Organization for Animal Health (OIE). This study examined the general health status of wild and cultured bivalves from southern Brazil and included diagnostic tests for the presence of Perkinsus sp., Bonamia sp., andMarteilia sp. Cultured bivalves included the mangrove oyster Crassostrea gasar (syn. Crassostrea brasiliana), the brown mussel Perna perna, the lion's paw scallop Nodipecten nodosus, andwing pearl oyster Pteria hirundo. Themangrove oyster Crassostrea rhizophorae and the carib pointed venus clam Anomalocardia brasiliana (syn. Anomalocardia flexuosa) were collected from wild populations. A variety of parasitic or commensal organisms were detected by histology including Ancistrocoma-like and Spenophrya-like organisms; Bucephalus genus, Nematopsis sp., Steinhausia sp., and Tylocephalum sp.; unidentified trematode; unknown protozoan and metazoans; and an amoeba parasite. Hemocytic infiltration was most commonly associated with parasitized animals. Histological, culture and molecular diagnostic tests did not find any evidence of the presence of OIE-listed pathogens or related species in this study. Although the current survey did not identify any pathogens or diseases of concern, it provides baseline health assessment data for these species against which any future disease developments or significant changes in population health can be compared. These data are also valuable with respect to the development and implementation of public policies related to aquatic animal healthWe would like to thank to the Ministry of Fisheries and Aquaculture, Brazil, for the research support provided to the Fundaçao de Amparo à Pesquisa do Estado de Santa Catarina (FAPESC), Brazil; the National Council of Technological and ScientificDevelopment, Brazil (CNPq-558222/2008-0), for supporting themacro- andmicroscopical analysis and for providing a grant (CNPq-301072/2007-8); the Coordenaçao de Aperfeiçoamento de Pessoal de Nivel Superior (CAPES), Brazil, for post-doctoral scholarship support for SS; the Pacific Biologic Station and Vancouver Island University (VIU) in Canada for supporting the molecular studiesPeer reviewe
    corecore