Preliminary look at feasibility of using marine reports of sea surface temperature for documenting climatic change in the western North Atlantic

The nature and quality of portions of the Marine Deck of sea-surface temperature (SST) records for Marsden Squares 114 and 78 (20°-40°N, 50°-60°W) have been examined to determine their suitability for historical analysis of SST, and for evidence of climatic variation. Apparently the data is numerous enough to demonstrate, using six-year means for individual months, a warming from 1910-1920 to a maximum in 1950-1960, and thereafter a cooling, coherent over both square (both in winter and summer), trends consistent with other sources of data

Historical evidence for two gyres in the Somali Current

Surface currents and some surface temperatures in the Somali Basin have been plotted for May and June of each year from 1900 to 1973 when any data were available. A current pattern containing two clockwise gyres, one situated south of 5N, the other between 5N and 10N, was usually present in June. It is similar to the one observed in a detailed survey of the Somali Current in 1979. Some evidence is presented suggesting that the timing of the development of the gyres, in relation to changes in winds, was similar in other years to the sequence observed in May and June 1979

Du cadastre ancien au graphe. Les dynamiques spatiales dans les sources fiscales médiévales et modernes

http://archeosciences.revues.org/3758National audienceMedieval and modern tax documents (fieldbooks, "compoix", cadasters...) give a rich spatial information. Whole territories are described plot per plot at different succesive periods. Nevertheless, historians don't know how to relate different states of spatial information on the long term. Moreover, there are no plot plans before the 17th and 18th century. We want to overcome this methodological lock with the following proposition: modelling ancient plots described in tax documents using the topological proprieties of the graph theory. The translation of the spatial data into graphs should allow to set up a commun language between the historical documents, mapped and not mapped. The article talks about the fondamental method choices and the used process to transform the spatial information of ancient plans into graphs which will allow us not only to compare them together, but also to compare them with cadastral registers that have no plan. Finally, it is within a Geographic Information System that will be tested the pertinence of comparing possibilities while studying the plot changes according to the spatiotemporal operators of changement (creation, disappearance, stability, dilatation, contraction, fusion, fission, deformation).Les documents fiscaux médiévaux et modernes (terriers, compoix, cadastres...) offrent une information spatiale riche. Des territoires entiers sont décrits parcelle par parcelle à des époques successives. Les historiens ne parviennent toutefois jamais à corréler ces différents états de l'information spatiale sur la longue durée, d'autant qu'on ne dispose d'aucun plan parcellaire avant les xviie-xviiie siècles. C'est ce verrou méthodologique qu'il s'agit de dépasser en proposant, dans le cadre de l'ANR Modelespace, une modélisation des parcellaires anciens décrits dans les documents fiscaux en mettant en œuvre les propriétés topologiques de la théorie des graphes. La conversion des données spatiales en graphes doit permettre de mettre en place un langage commun entre les documents historiques. L'article traite des choix méthodologiques fondamentaux et de la démarche utilisée pour transformer l'information spatiale des plans anciens en graphes susceptibles d'être appariés non seulement entre eux, mais encore avec des graphes issus de matrices cadastrales sans plan. Au final, c'est au sein d'un Système d'Information Géographique que devra être testée la pertinence des possibilités de comparaisons en étudiant les recompositions parcellaires selon des opérateurs spatio-temporels de changement (création, disparition, stabilité, dilatation, contraction, fusion, fission, déformation)

Measurements within the Pacific-Indian oceans throughflow region

Two hydrographic ... and trichlorofluoromethane (F-11) sections were carried out between the Australian continental shelf and Indonesia, in August 1989, on board the R.V. "Marion Dufresne". The sections lie in the easternmost part of the Indian Ocean where the throughflow between the Pacific Ocean and the Indian Ocean emerges. They allow us to describe the features of the water-property and circulation fields of the throughflow at its entrance in the Indian Ocean. Between the Australian continental shelf and Bali, the Subtropical and Central waters are separated from the waters of the Indonesian seas by a sharp hydrological front, located around 13°30S, below the thermocline down to 700 m. Near the coast of Bali, upwelling occurs in the near-surface layer under the effect of the Southeast monsoon; at depth, between 300 m to more than 800 m, a water mass of Northern Indian Ocean origin was present. (D'après résumé d'auteur

Deep Water Exchange through the Owen Fracture Zone in the Arabian Sea

From geostrophic calculations the exchange of deep water from the Somali into the Arabian Basin through the Owen Fracture Zone has been estimated to be about 2 Sv, with a seasonal modulation of the same magnitude. After leaving the Fracture Zone, the flow bifurcates into a northern and a southern branch, each closely following the slope of the Carlsberg Ridge. The weaker vertical gradients of the hydrographic properties in the deep Arabian Basin are consistent with enhanced vertical mixing at the rugged topography over the Carlsberg Ridge

PIXSIC: A Wireless Intracerebral Radiosensitive Probe in Freely Moving Rats

International audienceThe aim of this study was to demonstrate the potential of a wireless pixelated β+-sensitive intracerebral probe (PIXSIC) for in vivo positron emission tomographic (PET) radiopharmacology in awake and freely moving rodents. The binding of [ 11 C]raclopride to D 2 dopamine receptors was measured in anesthetized and awake rats following injection of the radiotracer. Competitive binding was assessed with a cold raclopride injection 20 minutes later. The device can accurately monitor binding of PET ligands in freely moving rodents with a high spatiotemporal resolution. Reproducible time-activity curves were obtained for pixels throughout the striatum and cerebellum. A significantly lower [ 11 C]raclopride tracer–specific binding was observed in awake animals. These first results pave the way for PET tracer pharmacokinetics measurements in freely moving rodents

Simplicial simple-homotopy of flag complexes in terms of graphs

International audienceA flag complex can be defined as a simplicial complex whose simplices correspond to complete subgraphs of its 1-skeleton taken as a graph. In this article, by introducing the notion of s-dismantlability, we shall define the s-homotopy type of a graph and show in particular that two finite graphs have the same s-homotopy type if, and only if, the two flag complexes determined by these graphs have the same simplicial simple-homotopy type. This result is closely related to similar results established by Barmak and Minian [J.A. Barmak, E.G. Minian, Simple homotopy types and finite spaces, Adv. Math. 218 (1) (2008) 87-104. doi:10.1016/j.aim.2007.11.019] in the framework of posets and we give the relation between the two approaches. We conclude with a question about the relation between the s-homotopy and the graph homotopy defined in [B. Chen, S.-T. Yau, Y.-N. Yeh, Graph homotopy and Graham homotopy, Selected papers in honor of Helge Tverberg, Discrete Math. 241 (1-3) (2001) 153-170. doi:10.1016/S0012-365X(01)00115-7.