Towards a cross-correlation approach to strong-field dynamics in Black Hole spacetimes

The qualitative and quantitative understanding of near-horizon gravitational dynamics in the strong-field regime represents a challenge both at a fundamental level and in astrophysical applications. Recent advances in numerical relativity and in the geometric characterization of black hole horizons open new conceptual and technical avenues into the problem. We discuss here a research methodology in which spacetime dynamics is probed through the cross-correlation of geometric quantities constructed on the black hole horizon and on null infinity. These two hypersurfaces respond to evolving gravitational fields in the bulk, providing canonical "test screens" in a "scattering"-like perspective onto spacetime dynamics. More specifically, we adopt a 3+1 Initial Value Problem approach to the construction of generic spacetimes and discuss the role and properties of dynamical trapping horizons as canonical inner "screens" in this context. We apply these ideas and techniques to the study of the recoil dynamics in post-merger binary black holes, an important issue in supermassive galactic black hole mergers.Comment: 16 pages, 5 figures, contribution to the proceedings volume of the Spanish Relativity Meeting ERE2011: "Towards new paradigms", Madrid, Spain, 29 Aug-2 Sep 201

Weighted automata as coalgebras in categories of matrices

The evolution from non-deterministic to weighted automata represents a shift from qual- itative to quantitative methods in computer science. The trend calls for a language able to reconcile quantitative reasoning with formal logic and set theory, which have for so many years supported qualitative reasoning. Such a lingua franca should be typed, poly- morphic, diagrammatic, calculational and easy to blend with conventional notation. This paper puts forward typed linear algebra as a candidate notation for such a unifying role. This notation, which emerges from regarding matrices as morphisms of suitable categories, is put at work in describing weighted automata as coalgebras in such categories. Some attention is paid to the interface between the index-free (categorial) language of matrix algebra and the corresponding index-wise, set-theoretic notation.Fundação para a Ciência e a Tecnologia (FCT

Black-hole horizons as probes of black-hole dynamics II: geometrical insights

In a companion paper [1], we have presented a cross-correlation approach to near-horizon physics in which bulk dynamics is probed through the correlation of quantities defined at inner and outer spacetime hypersurfaces acting as test screens. More specifically, dynamical horizons provide appropriate inner screens in a 3+1 setting and, in this context, we have shown that an effective-curvature vector measured at the common horizon produced in a head-on collision merger can be correlated with the flux of linear Bondi-momentum at null infinity. In this paper we provide a more sound geometric basis to this picture. First, we show that a rigidity property of dynamical horizons, namely foliation uniqueness, leads to a preferred class of null tetrads and Weyl scalars on these hypersurfaces. Second, we identify a heuristic horizon news-like function, depending only on the geometry of spatial sections of the horizon. Fluxes constructed from this function offer refined geometric quantities to be correlated with Bondi fluxes at infinity, as well as a contact with the discussion of quasi-local 4-momentum on dynamical horizons. Third, we highlight the importance of tracking the internal horizon dual to the apparent horizon in spatial 3-slices when integrating fluxes along the horizon. Finally, we discuss the link between the dissipation of the non-stationary part of the horizon's geometry with the viscous-fluid analogy for black holes, introducing a geometric prescription for a "slowness parameter" in black-hole recoil dynamics.Comment: Final version published on PR

A Percepção dos Auxiliares e Técnicos em Saúde Bucal da Atenção Básica Sobre a Política Nacional de Educação Permanente Implementada na Região Metropolitana de Vitória - Es

Introdução: A proposta da Educação Permanente em Saúde (EPS) implantada no Brasil destaca a importância do potencial educativo do processo de trabalho para a transformação da prática dos profissionais da área da saúde. A EPS na atenção básica é importante devido à necessidade de garantir a universalidade e a integralidade do Sistema Único de Saúde. Objetivo: Analisar a percepção dos Auxiliares e Técnicos em Saúde Bucal (ASBs/TSBs) sobre a Política Nacional de Educação Permanente em Saúde implementada para as Equipes de Saúde Bucal da Região Metropolitana da Grande Vitória, Espírito Santo, que atuavam na atenção básica entre 2007 e 2012. Metodologia: Estudo com abordagem qualitativa, cuja construção dos dados foi realizada por meio de um grupo focal. A discussão entre os sujeitos da pesquisa durante o grupo focal foi gravada e transcrita na íntegra e de forma literal, e analisada segundo a Análise de Conteúdo Temática. Resultados: As ASBs/TSBs não compreendiam a EPS e não a visualizavam na prática em serviço. Viam a mesma como cursos rápidos e pontuais. Mencionaram que antigamente os cursos e as rodas aconteciam com maior frequência. Citaram o número elevado de atendimentos, o que impossibilitava a ausência do consultório e participação em outras atividades, a desvalorização da profissão, e a prioridade para os dentistas. Conclusão: As ASBs/TSBs não enxergaram a implantação dessa política no seu dia a dia nem tampouco no seu local de trabalho, associando essa ausência a: falta de tempo, desvalorização da profissão, gestão da unidade e a escolha do próprio profissional

Evaluation of manioc (Manihot esculenta Crantz) cultivation in mixed cropping systems.

Avaliação da cultura da mandioca (Manihot esculenta Crantz) em sistema e policultivo: Yields and survival rates will be presented for three manioc cultivars(Pao IM 226, Vinagre IM 157 and Mandioca IM 116), planted between the rows in two mixed cropping systems, which were treated by application of 30% or 100% of the recommended fertilizer dose and inoculation or not with mycorrhizal fungi spores. With regard to yield, there is no statistically significant difference between the treatments viewed in isolation. However, there are statistically significant differences between the cultivars Pao (10.6 tons/ha) and Vinagre (5.5 tons/ha) in system 2; between 100% fertilization (5.2 tons/ha) and 30% fertilization (3.7 tons/ha) in system 3, and between the Pao cultivars in systems 2 (10.6 tons/ha) and 3 (5.4 tons/ha). The resprouting rates of the cutting were considered to be low. There was no statistically significant difference in survival rates between the treatments. The yields are lower than those normally obtained in the region, i.e., 20.0 tons/ha for Pao, 14.0 tons/ha for Vinagre and 16,0 tons/ha for manioc in monoculture

Mata ciliar é vida.

bitstream/item/26693/1/Mata-Ciliar-vida-Portal-Dia-de-Campo.pd

Potential worldwide distribution of Fusarium dry root rot in common beans based on the optimal environment for disease occurrence.

Root rots are a constraint for staple food crops and a long-lasting food security problem worldwide. In common beans, yield losses originating from root damage are frequently attributed to dry root rot, a disease caused by the Fusarium solani species complex. The aim of this study was to model the current potential distribution of common bean dry root rot on a global scale and to project changes based on future expectations of climate change. Our approach used a spatial proxy of the field disease occurrence, instead of solely the pathogen distribution. We modeled the pathogen environmental requirements in locations where in-situ inoculum density seems ideal for disease manifestation. A dataset of 2,311 soil samples from commercial farms assessed from 2002 to 2015 allowed us to evaluate the environmental conditions associated with the pathogen's optimum inoculum density for disease occurrence, using a lower threshold as a spatial proxy. We encompassed not only the optimal conditions for disease occurrence but also the optimal pathogen's density required for host infection. An intermediate inoculum density of the pathogen was the best disease proxy, suggesting density-dependent mechanisms on host infection. We found a strong convergence on the environmental requirements of both the host and the disease development in tropical areas, mostly in Brazil, Central America, and African countries. Precipitation and temperature variables were important for explaining the disease occurrence (from 17.63% to 43.84%). Climate change will probably move the disease toward cooler regions, which in Brazil are more representative of small-scale farming, although an overall shrink in total area (from 48% to 49% in 2050 and 26% to 41% in 2070) was also predicted. Understanding pathogen distribution and disease risks in an evolutionary context will therefore support breeding for resistance programs and strategies for dry root rot management in common beans

Caracterização de sintomas de deficiências em mudas de teca (Tectona grandis L. f.).

Este estudo teve por objetivo caracterizar os sintomas visuais de deficiência de macro e micronutrientes em mudas de teca.bitstream/item/24801/1/ct90-teca.pd

Solo: um patrimônio ameaçado.

bitstream/item/26700/1/Solo-um-patrimnio-ameaado-Portal-Dia-de-Campo.pd