Parâmetros bioquímicos foliares das espécies Licania tomentosa (Benth.) e Bauhinia forficata (Link.) para avaliação da qualidade do ar

Foliar analysis of biochemical parameters were carried out in order to investigate the influence of air pollutants on two tropical tree species (Licania tomentosa (Benth.) and Bauhinia forfícata (Link.)). Special attention was given to tropospheric ozone due to the fact that concentration levels in the region were found to be up to 140 µg m-3 for a 4 h average time, which is well above the value that can cause injuries to orchides and tobacco (59 µg m-3). Other pollutants such as nitrogen and sulphur oxides were measured and their ambient concentrations were also associated to biochemical alterations in the investigated species.

ClC-5 chloride channel and kidney stones : what is the link?

Nephrolithiasis is one of the most common diseases in the Western world. The disease manifests itself with intensive pain, sporadic infections, and, sometimes, renal failure. The symptoms are due to the appearance of urinary stones (calculi) which are formed mainly by calcium salts. These calcium salts precipitate in the renal papillae and/or within the collecting ducts. Inherited forms of nephrolithiasis related to chromosome X (X-linked hypercalciuric nephrolithiasis or XLN) have been recently described. Hypercalciuria, nephrocalcinosis, and male predominance are the major characteristics of these diseases. The gene responsible for the XLN forms of kidney stones was cloned and characterized as a chloride channel called ClC-5. The ClC-5 chloride channel belongs to a superfamily of voltage-gated chloride channels, whose physiological roles are not completely understood. The objective of the present review is to identify recent advances in the molecular pathology of nephrolithiasis, with emphasis on XLN. We also try to establish a link between a chloride channel like ClC-5, hypercalciuria, failure in urine acidification and protein endocytosis, which could explain the symptoms exhibited by XLN patients.

Memória, intertextualidade, literatura e semiótica : a tragédia e o trágico em Sandman

Este trabalho investiga as relações entre a literatura e a história em quadrinhos Sandman, escrita por Neil Gaiman. Para estabelecer o liame entre essas artes, descrevemos os primórdios da indústria dos quadrinhos de super-heróis, o seu desenvolvimento e as raízes dos gêneros literários populares de crime e horror, assim como as críticas que conduziram à censura e à subsequente superação desta – que lentamente tornou possível um novo tipo de discurso na área dos quadrinhos, permitindo um diálogo aberto com o mundo literário. Entendendo que as noções de intertextualidade, intermidialidade e semiose atuam como transmissores da memória da literatura e da cultura, adotamos a semiótica de Charles S. Peirce, para estabelecer o encadeamento semiósico do mito órfico, além de traçar a transformação da tragédia (conceito literário) em trágico (concepção filosófica) e as suas funções na narrativa de Sandman e no percurso de Morpheus, o herói condenado.