Linear stability of Einstein-Gauss-Bonnet static spacetimes. Part II: vector and scalar perturbations

We study the stability under linear perturbations of a class of static solutions of Einstein-Gauss-Bonnet gravity in $D=n+2$ dimensions with spatial slices of the form \Sigma_{\k}^n \times {\mathbb R}^+, \Sigma_{\k}^n an $n-$manifold of constant curvature \k. Linear perturbations for this class of space-times can be generally classified into tensor, vector and scalar types. In a previous paper, tensor perturbations were analyzed. In this paper we study vector and scalar perturbations. We show that vector perturbations can be analyzed in general using an S-deformation approach and do not introduce instabilities. On the other hand, we show by analyzing an explicit example that, contrary to what happens in Einstein gravity, scalar perturbations may lead to instabilities in black holes with spherical horizons when the Gauss-Bonnet string corrections are taken into account.Comment: 16 pages, 6 figure

Environments of Redshift Survey Compact Groups of Galaxies

Redshift Survey Compact Groups (RSCGs) are tight knots of N >= 3 galaxies selected from the CfA2+SSRS2 redshift survey. The selection is based on physical extent and association in redshift space alone. We measured 300 new redshifts of fainter galaxies within 1 h^{-1} Mpc of 14 RSCGs to explore the relationship between RSCGs and their environments. 13 of 14 RSCGs are embedded in overdense regions of redshift space. The systems range from a loose group of 5 members to an Abell cluster. The remaining group, RSCG 64, appears isolated. RSCGs are isolated and distinct from their surroundings to varying degrees, as are the Hickson Compact Groups. Among the 13 embedded RSCGs, 3 are distinct from their general environments (RSCG 9, RSCG 11 and RSCG 85).Comment: 35 pages, including 10 figures and 5 tables, accepted for publication in the Astronomical Journa

Desconstrução de Subalternidades e Idéias Anarquistas: possíveis convergências à caminho da insubordinação

A pesquisa em desenvolvimento nasceu dentro do projeto “Educação Intercultural: desconstrução de subalternidades em práticas educativas e socioculturais”. Surge da busca por aprofundar a perspectiva da desconstrução de subalternidades relacionando-a com movimentos políticos/sociais de insubordinação. O objetivo é discutir as possíveis convergências entre a opção pela desconstrução de subalternidades e as idéias anarquistas. Parte da desconstrução de subalternidades, enquanto uma perspectiva que leva em conta a complexidade do mundo atual, não acredita ser detentora de uma verdade redentora (Azibeiro) e busca a identificação de entre-lugares viáveis ao dialogo a construção do pensamento fronteiriço. É realizada por meio de pesquisa bibliográfica, análise e identificação dos pressupostos teóricos confluentes. Traz em conta os aportes da desconstrução de subalternidades: colonialidade do poder, eurocentrismo (Quijano), colonialidade-modernidade, diferença colonial, consciência dupla, pensamento fronteiriço (Mignolo) transmodernidade (Dussel), Entre-Lugar (Bhabha). Busca-se: levantar um pouco da história das idéias e movimentos anarquistas (Woodcock); traçar convergências como, por exemplo, a defesa pela desconstrução enquanto um postulado à transformação, à construção (Bakunin); refletir sobre o movimento antiglobalização (Liberato e Klein), sua relação com o surgimento de uma nova utopia, suas possíveis confluências ao manter um viés libertário, uma rebeldia visceral contra toda e qualquer forma de opressão e a autonomia como caminho e fim contribuindo com um horizonte de transformação social

Study of the Distillability of Werner States Using Entanglement Witnesses and Robust Semidefinite Programs

We use Robust Semidefinite Programs and Entanglement Witnesses to study the distillability of Werner states. We perform exact numerical calculations which show 2-undistillability in a region of the state space which was previously conjectured to be undistillable. We also introduce bases which yield interesting expressions for the {\em distillability witnesses} and for a tensor product of Werner states with arbitrary number of copies.Comment: 16 pages, 2 figure

LL37, a human antimicrobial peptide with immunomodulatory properties

Cationic antimicrobial peptides (AMPs) represent the first line of defense against many invading pathogens. These small amphipathic peptides are part of the innate immune system and have a broad-spectrum activity against bacteria, fungi and viruses. In mammals, at least two distinct groups of AMPs are found. Defensins are the more representatives and cathelicidins form the second group. The hCAP18/LL37 is the only known human cathelicidin. The antimicrobial peptide is referred to as LL37, since it has a 37 amino acids sequence starting with two leucines. It is a 4.5 kDa, cationic (+6), amphipathic -helical peptide, with a broad spectrum of antimicrobial activity. Besides its antimicrobial properties LL37 plays a central role in innate immune responses and inflammation. It has been identified as a potent chemoattractant for mast cells, monocytes, T lymphocytes and neutrophils using formyl-peptide receptorlike 1 (FPRL1). LL37 also promotes wound healing, angiogenesis and arteriogenesis and acts as immune adjuvant.y FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE and by national funds through the project PTDC/EDB/EBI/112170/2009 from the Fundação para a Ciência e Tecn