598 research outputs found
The BIC of a singular foliation defined by an abelian group of isometries
We study the cohomology properties of the singular foliation \F determined
by an action where the abelian Lie group
preserves a riemannian metric on the compact manifold . 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 is almost
free).
-- Poincar\'e Duality for intersection cohomology (the group is compact
and connected)
Top dimensional group of the basic intersection cohomology for singular riemannian foliations
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 . 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
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
We prove that the basic intersection cohomology where is the singular
foliation determined by an isometric action of a Lie group on the compact
manifold , is finite dimensional
Tautness for riemannian foliations on non-compact manifolds
For a riemannian foliation on a closed manifold , it is
known that is taut (i.e. the leaves are minimal submanifolds) if
and only if the (tautness) class defined by the mean curvature form
(relatively to a suitable riemannian metric ) is zero. In the
transversally orientable case, tautness is equivalent to the non-vanishing of
the top basic cohomology group , 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
, when is oriented. When 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
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
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
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