Robin boundary conditions in acoustic BTZ black holes

We introduce an analog model for the conformally coupled scalar field on the BTZ black hole. The model is based on the propagation of acoustic waves in a Laval nozzle. Since the BTZ black hole is not a globally hyperbolic spacetime, the dynamics of the scalar field is not well defined until extra boundary conditions are prescribed at its spatial infinity. We show that quasinormal modes (QNMs) satisfying Dirichlet, Neumann, and Robin boundary conditions in the BTZ black hole can be interpreted in terms of ordinary QNMs defined with respect to an appropriately extended nozzle. We also discuss the stability of our model with respect to small perturbations.Comment: 12 pages, 6 figure

A feasibility study with survival in swine model

Transrectal access still has some unsolved issues such as spatial orientation, infection, access and site closure. This study presents a simple technique to perform transcolonic access with survival in a swine model series. A new technique for NOTES perirectal access to perform retroperitoneoscopy, peritoneoscopy, liver and lymphnode biopsies was performed in 6 pigs, using Totally NOTES technique. The specimens were extracted transanally. The flexible endoscope was inserted through a posterior transmural incision and the retrorectal space. Cultures of bacteria were documented for the retroperitoneal space and intra abdominal cavity after 14 days. Rectal site was closed using non-absorbable sutures. There was no bowel cleansing, nor preoperative fasting. The procedures were performed in 6 pigs through transcolonic natural orifice access using available endoscopic flexible instruments. All animals survived 14 days without complications, and cultures were negative. Histopathologic examination of the rectal closure site showed adequate healing of suture line and no micro abscesses. The results of feasibility and safety of experimental Transcolonic NOTES potentially brings new frontiers and future wider applications for minimally invasive surgery. The treatment of colorectal, abdominal and retroperitoneal diseases through a flexible Perirectal NOTES Access (PNA) is a promising new approach

1-Methyl-7-(4-nitro­phen­yl)-3-phenyl­pyrazolo[3,4-b]pyrrolo[3,4-d]pyridine-6,8(3H,7H)-dione

In the title compound, C21H13N5O4, the dihedral angles formed between the planes of the phenyl and nitro­phenyl rings and that of the heterotricyclic plane are 41.29 (7) and 61.35 (6)°, respectively. In the crystal, weak C—H⋯O interactions help to establish the packing

Chemical and sensorial characterization of tropical syrah wines produced at different altitudes in northeast of the Brazil.

Over the years, viticulture has expanded to new regions outside the temperate zones, such as Northeast Brazil, India, Thailand, Myanmar, Vietnam, Bangladesh and Venezuela, characterized by the production of tropical wines. It is important for the productive sector to comprehend the effects of grapevine interaction with the characteristics of each new region on wines composition. In this study, the composition of wines of Syrah from two regions with different altitudes in Northeast Brazil were analyzed by different methodologies to characterize chemical compounds as sugar, acids, minerals, phenolics (anthocyanins, flavonols, stilbenes and condensed tannins) and the sensory profile. The wines of the Bahia region (1100 m of altitude) obtained high concentrations for chemical parameters related to color, monomeric anthocyanins, stilbenes and monomeric and oligomeric tannins. Wines of the low altitude region, Pernambuco (350 m of altitude) were characterized by higher concentrations of flavonols (kaempferol, isorhamnetin, quercetin and rutin) and polymerized tannins. The chemical composition of wines from the two studied regions was influenced by altitude. A trend towards higher concentrations in most for phenolic compounds analyzed was observed in wines from the higher altitude region during the two years of study. Regarding the sensory profile, fruity, floral, herbaceous and empyreumatic attributes aromatic obtained highest scores in wines of the 350 m altitude region, the other attributes were dependent on the year of harvest

A ESPACIALIZAÇÃO E A TERRITORIALIZAÇÃO DAS ESCOLAS DE ENSINO MÉDIO DO CAMPO EM ASSENTAMENTOS DE REFORMA AGRÁRIA: CONSTRUÇÃO COLETIVA E EM MOVIMENTO NO CEARÁ

The present work is the result of a research for a master’s thesis and it has as its central goal to analyze field education in the state of Ceará and whose object is the field secondary school at the agrarian reform settlements from the Landless Rural Workers’ Movement (MST). We sought to contribute to the debate over this theme from the struggle of the social movements in the construction of field education, a new concept and a new proposal which oppose to the current hegemonic education model. Therefore, it is a recent phenomenon in collective and ongoing construction in the country and in Ceará.O presente trabalho é fruto de uma pesquisa de mestrado e tem como objetivo central analisar a educação do campo no estado do Ceará, tendo como objeto a escola de ensino médio do campo dos assentamentos de reforma agrária do Movimento dos Trabalhadores Rurais Sem Terra. Procuramos contribuir para o debate do tema a partir da luta dos movimentos sociais na construção da educação do campo, um novo conceito e uma nova proposta que se contrapõem ao modelo hegemônico de educação vigente. Portanto, um fenômeno recente, em construção coletiva e em movimento no País e no Ceará