The geomorphology of Ireland's Coastline : patterns, processes and future prospects

Glacial history and sea-level have together helped shape the coastline of Ireland. Ireland's coastline suffers erosional problems at many points at present. More information is needed on the causes and type of erosion in progress. It is necessary that management plans be set in place in order to maintain coastal environments in the future.Géomorphologie des côtes irlandaises : modelés, processus et perspectives d'évolution Il n'existe pas, jusqu'ici, d'étude intégrée ni d'analyse systémique du littoral irlandais. L'évolution des différents secteurs côtiers dépend à la fois de la lithologie et de l'énergie des vagues. Celle-ci est beaucoup plus faible sur les côtes de la mer d'Irlande que le long de l'Atlantique où des vagues peuvent atteindre 20 m de hauteur (fig. 1 et photo 1).Sinnot A.M., Devoy R. J. N. The geomorphology of Ireland's Coastline : patterns, processes and future prospects. In: Hommes et Terres du Nord, 1992/3. Les littoraux. pp. 145-153

Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of Tay–Sachs disease

Chitin, the second most abundant polysaccharide on earth, is degraded by chitinases and chitobiases. The structure of Serratia marcescens chitobiase has been refined at 1.9 A resolution. The mature protein is folded into four domains and its active site is situated at the C-terminal end of the central (beta alpha)8-barrel. Based on the structure of the complex with the substrate disaccharide chitobiose, we propose an acid-base reaction mechanism, in which only one protein carboxylate acts as catalytic acid, while the nucleophile is the polar acetamido group of the sugar in a substrate-assisted reaction. The structural data lead to the hypothesis that the reaction proceeds with retention of anomeric configuration. The structure allows us to model the catalytic domain of the homologous hexosaminidases to give a structural rationale to pathogenic mutations that underlie Tay-Sachs and Sandhoff disease