Typing systems are used to discriminate between isolates ofHelicobacter pylori for epidemiological and clinical purposes. Discriminatory power and typeability are important performance criteria of typing systems. Discriminatory power refers to the ability to differentiate among unrelated isolates; it is quantitatively expressed by the discriminatory index (DI). Typeability refers to the ability of the method to provide an unambiguous result for each isolate analyzed; it is quantitatively expressed by the percentage of typeable isolates. We evaluated the discriminatory power and the typeability of the most currently used DNA fingerprinting methods for the typing of H. pyloriisolates: ribotyping, PCR-based restriction fragment length polymorphism (PCR-RFLP) analysis, and random amplified polymorphism DNA (RAPD) analysis. Forty epidemiologically unrelated clinical isolates were selected to constitute a test population adapted to the evaluation of these performance criteria. A meta-analysis of typeability and discriminatory power was conducted retrospectively with raw data from published studies in which ribotyping, PCR-RFLP, RAPD, repetitive extragenic palindromic DNA sequence-based PCR (REP-PCR), or pulsed-field gel electrophoresis (PFGE) was used. Experimental results and the meta-analysis demonstrated the optimal typeability (100%) and the excellent discriminatory powers of PCR-based typing methods: RAPD analysis, DIs, 0.99 to 1; REP-PCR, DI, 0.99; and PCR-RFLP analysis, DIs, 0.70 to 0.97). Chromosome restriction-based typing methods (ribotyping and PFGE) are limited by a low typeability (12.5 to 75%) that strongly decreases their discriminatory powers: ribotyping, DI, 0.92; PFGE, DIs, 0.24 to 0.88. We do not recommend the use of ribotyping and PFGE for the typing of H. pylori isolates. We recommend the use of PCR-based methods.

Tufs calcaires et travertins quaternaires : morphogenèse, biocénoses, paléoclimats et implantations paléolithiques. 1ère partie Le tuf calcaire de La Celle-sur-Seine (Seine et Marne) : nouvelles données sur un site clé du stade 11 dans le Nord de la France The La Celle-sur-Seine (Seine et Marne) tufa sequence: new data on a MIS 11 key site from northern France

La grotte du Renne à Arcy-sur-Cure est l'un des gisements les plus importants pour la transition Paléolithique moyen/supérieur mais sa position chronologique n 'est pas encore bien établie. Une coupe a donc été rouverte en 1998 pour reprendre des échantillons pour datation. Dans la perspective de la publication des données châtelperroniennes des fouilles Leroi- Gourhan, elle a permis de compléter les informations stratigraphiques et sédimentologiques de la couche X et de montrer la cohérence du dépôt. Un aperçu du matériel mis au jour à cette occasion est également donné.

Since 1994, the archaeological survey of the Pleistocene alluvial deposits of the north of the River Yonne valley, in the southeast of the Paris Basin, has allowed the discovery of twelve Palaeolithic settlements (Lower to Upper Palaeolithic), the plotting of the evolution of the Yonne terrace system and the proposal of a chronostratigraphical hypothesis. The settlements found in the six last alluvial terraces (Soucy 1 to 6, Etigny Le Brassot PLM, Le Fond des Blanchards and Le Chemin de l'Évangile 3 at Gron, Le Brassot at Étigny) have yielded many lithic industries andfaunal assemblages preserved in fine fluviatile sequences (sands and silts). The first studies and analyses of these settlements have provided much new information about modes of occupation in the palaeovalleys (Soucy), lithic production systems (Le Fond des Blanchards and Le Chemin de l'Évangile 3 at Gron) and the variability of the lithic industries (Soucy), and strategic behaviour in acquiring and exploiting animal resources (Soucy and Le Fond des Blanchards at Gron).

Resume. Soucy 1 est le premier des six gisements du Pleistocene moyen mis au jour en contexte fluviatile sur une ancienne terrasse de l'Yonne, à Soucy (Yonne), dans une séquence stratigraphique prudemment attribuée à l'interglaciaire holsteinien. Fouillé en sauvetage en 1995, il a livré plus de 2 500 restes (lithique, faune et galets). L'analyse spatiale pratiquée sur le gisement met en évidence des zones de débitage, dès concentrations de restes fauniques et une concentration de galets bruts indiquant des secteurs d'activités différenciées. Ces éléments permettent de proposer une interprétation de la fonction du site.