The use of quantitative mineralogy linked to palynological studies in palaeoenvironmental reconstruction : the case study of the "Lagoa Campestre" lake, Salitre, Minas Gerais, Brazil

La comparaison des contenus minéraux déterminés par spectroscopie IRTF et polliniques de sédiments lacustres de la région de Salitre (Brésil) montre que les variations des teneurs en phases minérales répercutent des changements régionaux ou locaux de l'environnement. Une évolution inverse entre couvert forestier et charge détritique des sédiments est observée pendant la phase lacustre pleistocène. La méthode utilisée permet la détection d'un hiatus sédimentaire marqué par un changement brutal du contenu minéral, ainsi que l'évaluation du caractère abrupt de certains changements du couvert végétal qui, en l'absence de datation, pourraient être confondus avec un hiatus sédimentaire. (Résumé d'auteur

Reduced in vitro susceptibility to artemisinin derivatives associated with multi-resistance in a traveller returning from South-East Asia

Decreased in vitro susceptibility to dihydroartemisinin (21.2 nM) and artesunate (16.3 nM) associated with decreased susceptibility or resistance to quinine (1131 nM), mefloquine (166 nM), lumefantrine (114 nM), pyronaridine (70.5 nM) and piperaquine (91.1 nM) is reported in a patient returning from South-East Asia after trekking along the Mekong from the south of Laos to the north of Thailand. Decreased in vitro susceptibility to artemisinin derivatives did not appear to be mediated by the number of copies of pfmdr1 or pfATPase6, pfcrt, pfmdr1 or pfmrp polymorphism. The high IC50 to mefloquine of this Asian isolate was not associated with pfmdr1 copy number. Pfnhe-1 microsatellite ms4760 showed a profile 7 (ms4760-7) with three repeats of DNNND and one repeat of DDDNHNDNHNN, which is associated with high quinine reduced susceptibility. The patient recovered in three days without relapse after treatment with the association of quinine and doxycycline. Decreased in vitro susceptibility to quinine and the delayed effect of doxycycline may both have contributed to the delayed parasite clearance time, D4 (0.5%) and D7 (0.004%). The in vitro data, with IC50 for dihydroartemisinin and artesunate were up to ten times those of the reference clone W2, which suggests that this isolate may be resistant to artemisinin derivatives, associated with a decreased susceptibility to quinine

An extrasolar planetary system with three Neptune-mass planets

Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5-20 times larger than the Earth and are mainly found on close-in orbits with periods of 2-15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 AU (the Sun-Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.Comment: 17 pages, 3 figures, preprint of the paper published in Nature on May 18, 200

A Escuta de Jovens em Filmes de Pesquisa

Apresenta-se trajetória de um grupo de pesquisa dedicado à produção de conhecimento sobre jovens de espaços populares no contexto de produção de filmes de pesquisa. Dois filmes são descritos e interpretados com especial destaque aos dispositivos utilizados para colocar em diálogo as narrativas de si e contextos de vida e sociabilidade de jovens através de imagens e sons. A representação fílmica não se confunde com um retrato do real, mas, em vez disso, é reconstituição através da seleção, tradução e montagem do produto que se quer compartilhar com o público. As entrevistas narrativas concebidas em bases dialógicas são elementos estruturantes da produção dos filmes que buscam apresentar o ser-jovem em sua complexidade

The Immune Cellular Effectors of Terrestrial Isopod Armadillidium vulgare: Meeting with Their Invaders, Wolbachia

Most of crustacean immune responses are well described for the aquatic forms whereas almost nothing is known for the isopods that evolved a terrestrial lifestyle. The latter are also infected at a high prevalence with Wolbachia, an endosymbiotic bacterium which affects the host immune system, possibly to improve its transmission. In contrast with insect models, the isopod Armadillidium vulgare is known to harbor Wolbachia inside the haemocytes.In A. vulgare we characterized three haemocyte types (TEM, flow cytometry): the hyaline and semi-granular haemocytes were phagocytes, while semi-granular and granular haemocytes performed encapsulation. They were produced in the haematopoietic organs, from central stem cells, maturing as they moved toward the edge (TEM). In infected individuals, live Wolbachia (FISH) colonized 38% of the haemocytes but with low, variable densities (6.45±0.46 Wolbachia on average). So far they were not found in hyaline haemocytes (TEM). The haematopoietic organs contained 7.6±0.7×10(3)Wolbachia, both in stem cells and differentiating cells (FISH). While infected and uninfected one-year-old individuals had the same haemocyte density, in infected animals the proportion of granular haemocytes in particular decreased by one third (flow cytometry, Pearson's test = 12 822.98, df = 2, p<0.001).The characteristics of the isopod immune system fell within the range of those known from aquatic crustaceans. The colonization of the haemocytes by Wolbachia seemed to stand from the haematopoietic organs, which may act as a reservoir to discharge Wolbachia in the haemolymph, a known route for horizontal transfer. Wolbachia infection did not affect the haemocyte density, but the quantity of granular haemocytes decreased by one third. This may account for the reduced prophenoloxidase activity observed previously in these animals

Barcoding T Cell Calcium Response Diversity with Methods for Automated and Accurate Analysis of Cell Signals (MAAACS)

International audienceWe introduce a series of experimental procedures enabling sensitive calcium monitoring in T cell populations by confocal video-microscopy. Tracking and post-acquisition analysis was performed using Methods for Automated and Accurate Analysis of Cell Signals (MAAACS), a fully customized program that associates a high throughput tracking algorithm, an intuitive reconnection routine and a statistical platform to provide, at a glance, the calcium barcode of a population of individual T-cells. Combined with a sensitive calcium probe, this method allowed us to unravel the heterogeneity in shape and intensity of the calcium response in T cell populations and especially in naive T cells, which display intracellular calcium oscillations upon stimulation by antigen presenting cells

Chapitre 8 : Janvier - février 1929

« Des tas d’idées épatantes. Ce serait dommage que mon diplôme soit bâclé et raté. Il faut que j’y travaille »(Lettre du 13 janvier) Vendredi 4 janvier [1929] [Munich] […] Je me repose. Frisch m’a téléphoné, j’ai pris le thé une fois chez lui, j’y vais ce soir. Il m’a emmené hier soir chez Strich. Il y a Fritz Strich, professeur de littérature ici, qui a l’air bien. Je dois le revoir. Et Walter Strich, un philosophe. Große Gesellschaft, le grand salon intellectuel de Munich, des peintres, Rin..

Chapitre 5 — Février-mars 1928

« Curieuse impression de fouillis, de fermentation, d’ignorance où l’on est de l’avenir. […] Qu’est-ce qui mijote dans la grande marmite ? » (lettre du 5 mars 28) [Mercredi] 1er février 1928 Nouvelles mélangées : Gide aurait l’intention, disait Viénot à midi, de revenir dans 3 semaines présenter son film. Ce soir, on dînera avec Gide, et on le mènera à la gare. Il devait partir hier, mais a remis son départ à aujourd’hui. Viénot très embêté par le discours de Strese­mann, celui de Rheinbaben...

Les lettres à Carl Heinrich Becker

… was wär auch diese Welt, wenn sie nicht wär ein Einklang freier Wesen ? […] wie hölzern wär sie, wie kalt ? …(Hölderlin, Hyperion, 2. Band, 2. Buch, 5. Brief) Sèvres le 25 mai 1928 Monsieur le Ministre, sans aucune hésitation je vous aurais imposé mon mauvais alle­mand si je n’avais été pris de honte devant vous qui, sans être spécia­liste, possédez si bien notre langue, et, mieux, l’esprit de notre lan­gue. Vous auriez dit assurément que j’avais bien mal mis à profit mon séjour à Berlin ; ..