Comment on "Germinal center helper T cells are dual functional regulatory cells with suppressive activity to conventional CD4+ T cells"

http://www.jimmunol.org/content/179/2/731.1.ful

More on donor-derived T-cell leukemia after bone marrow transplantation

http://www.nejm.org/doi/full/10.1056/NEJMc06105

Hierarchical Curl-Conforming Vector Bases for Pyramid Cells

Advanced applications of the finite element method use hybrid meshes of differently shaped elements that need transition cells between quadrilateral and triangular faced elements. The greatest ease of construction is obtained when, in addition to triangular prisms, one uses also pyramids with a quadrilateral base, as these are the transition elements with the fewest possible faces and edges. A distinctive geometric feature of the pyramid is that its vertex is the point in common with four of its faces, while the other canonical elements have vertices in common with three edges and three faces, and that is why pyramids’ vector bases have hitherto been obtained with complex procedures. Here we present a much simpler and more straightforward procedure by shifting to a new paradigm that requires mapping the pyramidal cell into a cube and then directly enforcing the conformity of the vector bases with those used on adjacent differently shaped cells (tetrahedra, hexahedra and triangular prisms). The hierarchical curl-conforming vector bases derived here have simple and easy to implement mathematical expressions, including those of their curls. Bases completeness is demonstrated for the first time, and results confirming avoidance of spurious modes and faster convergence are also reported

Curl-Conforming Vector Bases for Hybrid Meshes: A New Paradigm for Pyramid Elements

A simple procedure for obtaining hierarchical curlconforming pyramid bases has been obtained by shifting to a new paradigm that requires the mapping of the pyramidal cell into a cube and then directly imposing the conformity of the vector bases with those used on adjacent differently shaped cells (tetrahedra, hexahedra and triangular prisms). This summary discusses and generalizes some features of the new construction method recently published elsewhere

Assessing Curl-Conforming Bases for Pyramid Cells

Successful three-dimensional finite element codes for Maxwell’s equations must include and deal with all four types of geometrical shapes: tetrahedra, bricks, prisms, and quadrangular-based pyramids. However, pyramidal elements have so far been used very rarely because the basis functions associated with them have complicated expression, are complex in derivation, and have never been comprehensively validated. We recently published a simpler procedure for constructing higher-order vector bases for pyramid elements, so here we fill a gap by discussing a whole set of test case results that not only validate our new curl-conforming bases for pyramids, but which enable validation of other codes that use pyramidal elements for finite element method applications. The solutions of the various test cases are obtained using either higher order elements or multipyramidal meshes or both. Further-more, the results are always compared with the solutions obtained with classical tetrahedral meshes using higher order bases. This allows us to verify that purely pyramidal meshes and elements give numerical results of comparable accuracy to those obtained with multitetrahedral meshes that use elements of the same order, essentially requiring the same number of degrees of freedom. The various results provided here also show that higher order vector bases always guarantee a superior convergence of the numerical results as the number of degrees of freedom increases

Produção de semente genética de arroz irrigado através do sistema de transplante de mudas.

bitstream/item/31543/1/comunicado60.pd

Secagem do arroz.

bitstream/CPACT-2009-09/11058/1/comunicado_145.pd

Hierarchical Divergence Conforming Bases for Tip Singularities in Quadrilateral Cells

Electromagnetic scattering from targets such as thin conducting plates induce singular currents and charges at sharp edges and sharp tips. In this article, a hierarchical family of divergence-conforming singular basis functions are presented for modeling the singularities associated with current and charge density at tips. These new basis functions are used to increment existing edge-singular bases so that on cells that contain a singular tip where two singular edges join together, the final base combines a hierarchical polynomial representation with linearly independent singular terms that incorporate general exponents that may be adjusted for the specific wedge angle of interest and for the specific angle at the tip. Several variations on the tip functions are proposed