Cytochemical characterization and ultrastructural organization in calluses of the agarophyte Gracilariopsis tenuifrons (Gracilariales, Rhodophyta).

The culture and physiology of red macroalgae calluses are well documented. To date, however, no report has either performed a cytochemical analysis or characterized the ultrastructural organization of calluses at different stages of development and under the effect of plant growth regulators. Therefore, to undertake such analyses, this work studied the red seaweed Gracilariopsis tenuifrons (Bird et Oliveira) Fredericq et Hommersand. Morphology studies suggested three types of calluses: a) terminal callus having an irregular amorphous shape and filamentous projections originating from the cortical region of the thallus; b) apical callus growing on apical branches and having an elongated semispherical shape; and c) intercalary callus developing along the intermediary region of the thallus and having the appearance of small declivities with irregular edges. The abundance of intercalary calluses over terminal and apical calluses is most likely a result of a major cortical surface that would support the cellular growth required to generate calluses. Callus development was initially observed as a matrix of cellular disorganization with filamentous projections; then, the cellular mass seemed to become more compact with spherical uncolored aspect. The presence of starch grains in the inner part of the explant could be explained by absorption from the culture medium and by proper biosynthesis during callus development. Cell wall reaction to staining suggested cellulose and agar composition with acidic polysaccharides. Results suggest that none of the three morphological types of calluses showed any significant differences on the basis of either cytochemistry or ultrastructural organization.

Gerenciamento de dados marinhos no contexto brasileiro

In a context of rapidly growing demand of information and production of technical and scientific knowledge about biotic and abiotic parameters of marine and coastal environments, the process of design integrated databases programs and geo-portals for disseminating information becomes imperative. Although isolated efforts have been proposed in recent years in Brazil, the creation of broadly accessible databases seems inevitable. Furthermore, the peculiarities of acquisition and processing marine data (expensive, complex and dynamic) demand an optimization of time and resources for new research projects and knowledge basis. In this work we address this issue contextualizing the demands for the implementation and marine data modelling projects, focusing on theoretical and practical aspects providing guidelines and connectivities establishing future efforts towards the dissemination of marine and coastal information in Brazil.

Em um contexto de franco crescimento de demanda e produção de conhecimento técnico e cientifico a respeito de parâmetros bióticos e abióticos de ambientes marinhos e costeiros, a concepção de programas de desenvolvimento de bancos de dados e geo-portais de disseminação de informação torna-se imperativa. Embora apenas esforços pontuais tenham sido propostos nos últimos anos, a criação de bases de dados de acesso mais amplo parece inevitável tendo em vista as peculiaridades práticas de aquisição e processamento de dados marinhos: caros, complexos e dinâmicos. Este trabalho pretende abordar tal questão contextualizando as necessidades e demandas para projetos desta natureza, focando aspectos teóricos e práticos da implementação de modelos de dados marinhos propondo diretrizes para que esforços futuros sejam estabelecidos visando a disseminação da informação marinha e costeira no Brasil.