Time-variations of equivalent water heights'from Grace Mission and in-situ river stages in the Amazon basin

Gravity Recovery and Climate Experiment (GRACE) mission is dedicated to measuring temporal variations of the Earth's gravity field. In this study, the Stokes coefficients made available by Groupe de Recherche en Géodésie Spatiale (GRGS) at a 10-day interval were converted into equivalent water height (EWH) for a ~4-year period in the Amazon basin (from July-2002 to May-2006). The seasonal amplitudes of EWH signal are the largest on the surface of Earth and reach ~ 1250mm at that basin's center. Error budget represents ~130 mm of EWH, including formal errors on Stokes coefficient, leakage errors (12 ~ 21 mm) and spectrum truncation (10 ~ 15 mm). Comparison between in situ river level time series measured at 233 ground-based hydrometric stations (HS) in the Amazon basin and vertically-integrated EWH derived from GRACE is carried out in this paper. Although EWH and HS measure different water bodies, in most of the cases a high correlation (up to ~80%) is detected between the HS series and EWH series at the same site. This correlation allows adjusting linear relationships between in situ and GRACE-based series for the major tributaries of the Amazon river. The regression coefficients decrease from up to down stream along the rivers reaching the theoretical value 1 at the Amazon's mouth in the Atlantic Ocean. The variation of the regression coefficients versus the distance from estuary is analysed for the largest rivers in the basin. In a second step, a classification of the proportionality between in situ and GRACE time-series is proposed.

Nicolas Sanson and his Map: The Course of the Amazon River

One of the first scientific maps of the Amazon region, The Course of the Amazon River (Le Cours de La Rivière des Amazones), was constructed by Nicolas Sanson, a French cartographer of the seventeenth century, and served as the prototype for many others. The evaluation of this chart, until now, has been that it is a very defective map, a sketch based on a historical account, according to the opinion of La Condamine. Thus, the aim of the present work was to prove that the map of the Amazon River traced by Nicolas Sanson is a scientific work, a map that presents precise geographic coordinates considering its time, shows a well-determined prime meridian, and also employs a creative methodology to deduce longitudes from latitudes and distances that had been covered. To show such characteristics, an analysis of the accuracy of the map was made by comparing its latitudes and longitudes with those of a current map. We determined the prime meridian of this map and analyzed the methodology used for the calculation of longitudes. The conclusion is that it is actually a good map for the time, particularly considering the technology and the limited information that Sanson had at his disposal. This proves that the negative assertion of La Condamine is unfounded.

Processo grupal: reflexões de uma equipe de enfermagem

Estudo qualitativo, exploratório-descritivo com o objetivo de analisar o processo grupal de uma equipe de enfermagem do Hospital de Clínicas de Porto Alegre (HCPA), à luz da Teoria de Grupo Operativo de Pichon-Rivière. A coleta de dados ocorreu em 2008, por meio de questionário semiestruturado e grupo focal. Concepção de trabalho em grupo é uma das quatro categorias resultantes do estudo, sendo objeto de abordagem neste artigo. Depreendeu-se que o conhecimento sobre processo grupal necessita ser compartilhado, divulgado e discutido desde a formação acadêmica, no curso de graduação em enfermagem, e desenvolvido ao longo de toda a carreira profissional. À medida que se conhece e consegue identificar os principais indicadores presentes no processo grupal, a equipe pode conduzir-se operativamente, considerando não apenas resultados, mas principalmente o caminho percorrido até o alcance da tarefa, visando à aprendizagem grupal.

La philosophie comme méthodologie: la conception sceptico-rationaliste de la raison Chez Bayle

Bayle est souvent considéré comme sceptique, mais sa conception de la raison n'est pas toujours claire ; ce qui en revanche est clair, c'est qu'il manifeste une profonde méfiance à l'égard des capacités de la raison de livrer une connaissance certaine. Cependant, une nouvelle interprétation de Bayle comme rationaliste «stratonicien » a été développée par Gianluca Mori, qui donne une description détaillée de Bayle comme philosophe critique désireux de rendre compte de toutes positions possibles dans leur complexité et de tirer toutes les conséquences des arguments invoqués au service des principes dits « stratoniciens ». Cette conception de Bayle comme rationaliste critique stratonicien rend possible une interprétation de Bayle moins comme un « supersceptique » à la Richard Popkin, que celui qui permet à la raison d'opérer avec une portée et une autorité plus grandes que ne le permettrait le scepticisme. Mori affirme que la conception de la raison chez Bayle est assez forte ; selon lui, la raison peut aller jusqu'au bout, avec une autorité absolue, et tirer des conclusions. Je soutiens que la conception de la nature et de la fonction de la raison chez Bayle se situe en fait entre le rationalisme stratonicien de Mori et l'interprétation « supersceptique » de Popkin. Comme Mori, je pense qu'il s'agit d'un rationalisme « critique » ; mais contre lui, je pense que la raison elle-même définit et recommande ses propres limites. J'appelle cette conception de la raison « sceptico-rationaliste » et, en suivant Bayle, je suggère comment le « bon sens » (qui fait partie de la raison) aide à définir ces limites.