Predicted Relative Metabolomic Turnover (PRMT): determining metabolic turnover from a coastal marine metagenomic dataset

We present an approach in which the semantics of an XML language is defined by means of a transformation from an XML document model (an XML schema) to an application specific model. The application specific model implements the intended behavior of documents written in the language. A transformation is specified in a model transformation language used in the Model Driven Architecture (MDA) approach for software development. Our approach provides a better separation of three concerns found in XML applications: syntax, syntax processing logic and intended meaning of the syntax. It frees the developer of low-level syntactical details and improves the adaptability and reusability of XML applications. Declarative transformation rules and the explicit application model provide a finer control over the application parts affected by adaptations. Transformation rules and the application model for an XML language may be composed with the corresponding rules and application models defined for other XML languages. In that way we achieve reuse and composition of XML applications

Distribution and activity of chitinolytic enzymes in the digestive tract of birds and mammals

The extraction and purification of chitinolytic enzymes devoid of any lysozymic activity, taken from the gastric mucosa of mamals, indicated that these enzymes are true chitinases, rather than lysozymes with chitinolytic activity. A close relationship was found between chitinase secretions in the digestive tract and the nature of the normal diet of the species considered. Changing the diet of an animal (mouse, rat, hamster, guinea pig) for a few weeks did not modify its ability or inability to secrete chitinase. In the digestive tract of birds, chitinase is secreted only by the gtastric mucosa. All the more or less insectivorous birds so far studied, including chickens, do secrete gastric chitinases. No chitinase secretion was dected in the pigeon or the parrot. In mammals, gastric chitinases were found in omnivorous and insectivorous species belonging to the orders Insectivora, Chiroptera, Carnivora, Rodenta and primates. in the pig, chitinases are secreted by the gastric mucosa and by the pancreas. The digestibility of chitin in both a purified and a natural form was estimated in feeding experiments with mice, Japanese nightingales and chickens. From 19% to 58% chitin was digested by mice and chickens that were fed a diet containing pure chitin, and by Japanese nightingales that were fed mealworm larvae

Composition chimique du tube d'un pogonophore ( siboglinum

peer reviewedThe chemical composition of the skeletons of two species of pterobranchs, Cephalodiscus inaequatus (Andersson) and Rhabdopleura sp. of one pogonophore, Siboglinum sp., was studied quantitatively. The tubes of Siboglinum sp. are composed of proteins (about 47 %) and chitin (about 33 %) ; these two substances are probably associated in large amounts as glycoproteic complexes. The amino acid composition suggests that these proteins belong to the class of scleroproteins. Their composition is very differtent from that of collagen and keratin. On the contrary, the coenecium of the two pterobranchs does not contain any chitin and the amounts of proteins are much lower (19 %). The proteins are characterized by a very high proportion of glycine (35 % of the total amount of amino acids).La nature chimique du tube d'un Pogonophore, Siboglinum sp., et des formations squelettiques de deux Ptérobranches, Céphalodiscus inaequatus (ANDERSON) et Rhabdopleura sp. a été étudiée au moyen de méthodes quantitatives. Les tubes de Siboglinum sp. se composent essentiellement de protéines (environ 47 %) et de chitine (environ 33 %), ces deux substances étant vraisemblablement associées en grande partie sous forme de complexes glycoprotéiques. La composition en acides aminés de les protéines s'apparente à celle des scléroprotéines et s'écarte profondément de la composition des collagènes et des kératines. Le coenecium des Ptérobranches, par contre, ne contient pas de chitine et sa teneur en protéines est beaucoup moins élevée (environ 19 %). Ces protéines sont caractérisées par la proportion remaquablement élevée de glycocolle (35 % de la somme des acides aminés d'origine protéique)