A user's guide to the Encyclopedia of DNA elements (ENCODE)

The mission of the Encyclopedia of DNA Elements (ENCODE) Project is to enable the scientific and medical communities to interpret the human genome sequence and apply it to understand human biology and improve health. The ENCODE Consortium is integrating multiple technologies and approaches in a collective effort to discover and define the functional elements encoded in the human genome, including genes, transcripts, and transcriptional regulatory regions, together with their attendant chromatin states and DNA methylation patterns. In the process, standards to ensure high-quality data have been implemented, and novel algorithms have been developed to facilitate analysis. Data and derived results are made available through a freely accessible database. Here we provide an overview of the project and the resources it is generating and illustrate the application of ENCODE data to interpret the human genome

Stable oxygen and hydrogen isotopic tracers in Amazon shelf waters during Amasseds

A detailed hydrographic survey of the water column of the Amazon shelf was performed using stable oxygen and hydrogen isotopes to determine the source and fate of waters on the shelf. delta(18)O-H2O and deltaD measurements were made on water column samples from approximately 60 stations (three depths per station) which were each collected during four Amasseds (A Multidisciplinary Amazon Shelf SEDiment Study) cruises: I8909-August 1989, falling river discharge; I9002-March 1990, rising river discharge; I9004-May 1990, peak discharge: I9113-November 1991, minimum discharge. Isotopes were compared with salinity and temperature measurements in order to identify water masses and mixing. The characteristics (salinity, temperature, delta(18)O, deltaD and d) are proposed for the following end-number water masses: river water, open ocean surface water (0-100 m) and open ocean intermediate water (> 300 m). River water: salinity = 0; temperature approximate to 27-29 degreesC; delta(18)O = -4.2 to -6.8 per mil; deltaD approximate to -22.1 to -38.9 per mil: d = 9.4 to 17.0 per mil (compare to d = 10 for Meteoric Water Line). Open ocean surface water (approximate to 0-100 m): salinity approximate to 35 to 37; temperature approximate to 25-29 degreesC; delta(18)O approximate to -1 to +2 per mil; deltaD -3.6 to +10.2 per mil. Open ocean intermediate water (greater than or equal to300 m): salinity approximate to 34.6 to 35.0; temperature = 4.8 to 9.6 degreesC; delta(18)O = -0.2 to +0.3 per mil; deltaD = -8.72 to -0.95 per mil. Amazon river water follows a seasonal isotopic cycle in response to basin hydrologic processes. River water mixes with equatorial surface ocean water and intermediate ocean waters originating in mid-to-high southem latitudes. Near-surface waters in the region of North Brazil Current retroflection were identical in isotope-salinity space to waters on the outer shelf during November 1991.Un suivi hydrologique de la colonne d’eau du plateau continental au débouché de l’Amazone a été réalisé en utilisant les isotopes de l’oxygène stable et de l’hydrogène pour déterminer lˈorigine et la destinée des eaux sur la plate-forme. Les mesures des δ18O-H2O et δD ont été réalisées à soixante stations (trois niveaux par station) durant quatre campagnes Amasseds (A multidisciplinary Amazon shelf sediment study) : la première en août 1989 en période d’apports décroissants, la seconde en mars 1990, quand ces apports croissent, la troisième lors du pic de la décharge (mai 1990) et la dernière en novembre 1991, lors du minimum dˈapports. Les isotopes ont été comparés à la salinité et à la température pour identifier les masses d’eaux et leurs mélanges. L’article propose les caractéristiques (salinité, température, δ18O, δD et d pour les masses d’eau suivantes: eau de rivière, eau océanique de surface (0 à 100 m) et eau océanique intermédiaire (> 300 m). Les eaux amazoniennes suivent un cycle saisonnier isotopique en réponse aux processus hydrologiques du bassin. Les eaux du fleuve se mélangent avec lˈeau océanique équatoriale de surface et les eaux intermédiaires originaires des latitudes moyennes ou élevées de l’hémisphère Sud. En novembre 1991, les eaux proches de la surface dans la région de rétroflexion du courant Nord du Brésil sont identiques, en termes de salinité et de rapports isotopiques, aux eaux à l’extérieur du plateau continental