Entre exil et prison

Nous proposons dans cet article de réfléchir aux effets de répétition entre et à travers les générations liées à la part d’ombre logée dans l’héritage. Nous verrons comment, dans le cadre de la clinique carcérale, la situation de rupture sociale engage une expérience de « désaffiliation » qui entre en écho avec les blessures de la filiation. Notamment, en nous appuyant sur la rencontre clinique avec Alban, nous pointerons en quoi le « devenir père » en prison est venu réveiller chez lui la honte liée à l’expérience de l’exil, et l’a conduit à revisiter les liens l’attachant à sa lignée. Ce sera l’occasion d’observer comment il se trouve avant tout prisonnier d’une mémoire entachée par l’indicible, qui le laisse aux prises avec une souffrance léguée par ceux qui l’ont précédé

Consommation d'eau de la vigne en conditions hydriques non limitantes. Formulation simplifiée de la transpiration

La modélisation géometrique de la vigne, utilisée pour l'interception du rayonnement solaire (RIOU et al. 1989) est d'abord reprise pour évaluer les bilans radiatifs de la vigne et du sol intercalaire. La vérification expérimentale est satisfaisante. Après une période pluvieuse, les différents flux du bilan d'energie du vignoble sont ensuite mesurés, notamment grâce à la méthode des corrélations tourbillonnaires tandis que la transpiration de la vigne seule est obtenue par une mesure de flux de sève (VALANCOGNE et NASR 1993).Trois grandeurs concernant la vigne elle-même restent proches: le taux de transpiration par rapport à l'évaporation totale , le taux d' absorption du rayonnement net par rapport au bilan radiatif total et le taux d'absorption du rayonnement solaire par rapport au rayonnement global absorbé par le vignoble; une simulation montre que ces deux derniers taux restent voisins quand la distance entre rangs varie. L'évapotranspiration maximum étant finalement exprimée correctement par la formule de PENMAN (1948), ces résultats conduisent à proposer une formulation simple de la transpiration de la vigne en conditions hydriques non limitantes.Water use of grapevines well supplied with water. Simplified expression of transpirationA model of solar radiation interception by a vineyard canopy from simple geometrical assumptions (Riou et al. 1989) is first extended into a model of the whole radiative balance of the vine rows and of the intervening soil surface; experimental validation is excellent. After a rainy period, the various fluxes taking part in the energy balance of a vineyard canopy were measured, among which total evaportranspiration by an eddy correlation technique, and vine transpiration from a sap-flow estimation (Valancogne et Nasr 1993). Three partition rates quantifying the exchanges of the vines alone remain noticeably close to each other: those of transpiration over total evaportranspiration, of absorbed net radiation over overall radiative balance, and of intercepted global radiation over global radiation intercepted by the whole canopy. From a simulation, evidence is provided these two latter rates are still hardly distinguishable when the row spacing is changed. As maximum evapotranspiration is quite correctly expressed by the Penman formula, these results lead to the proposal of a simple method for estimating transpiration of grapevines well supplied with water

Role of CAP350 in Centriolar Tubule Stability and Centriole Assembly

BACKGROUND: Centrioles are microtubule-based cylindrical structures composed of nine triplet tubules and are required for the formation of the centrosome, flagella and cilia. Despite theirs importance, centriole biogenesis is poorly understood. Centrosome duplication is initiated at the G1/S transition by the sequential recruitment of a set of conserved proteins under the control of the kinase Plk4. Subsequently, the procentriole is assembled by the polymerization of centriolar tubules via an unknown mechanism involving several tubulin paralogs. METHODOLOGY/PRINCIPAL FINDINGS: Here, we developed a cellular assay to study centrosome duplication and procentriole stability based on its sensitivity to the microtubule-depolymerizing drug nocodazole. By using RNA interference experiments, we show that the stability of growing procentrioles is regulated by the microtubule-stabilizing protein CAP350, independently of hSAS-6 and CPAP which initiate procentriole growth. Furthermore, our analysis reveals the critical role of centriolar tubule stability for an efficient procentriole growth. CONCLUSIONS/SIGNIFICANCE: CAP350 belongs to a new class of proteins which associate and stabilize centriolar tubules to control centriole duplication

Looking beyond forest cover: an analysis of landscape-scale predictors of forest degradation in the Brazilian Amazon.

While forest degradation rates and extent exceed deforestation in the Brazilian Amazon, less attention is given to the factors controlling its spatial distribution. No quantified correlation exists between changes of forest structure due to anthropogenic disturbances and dynamics of land use and cover change occurring at broader spatial levels. This study examines the influence of multi-scale landscape structure factors (i.e. spatial composition, configuration and dynamic of land use/cover) on primary forest's aboveground biomass (AGB), spanning from low to highly degraded, in Paragominas municipality (Pará state). We used random forest models to identify the most important landscape predictors of degradation and clustering methods to analyze their distribution and interactions. We found that 58% of the variance of AGB could be explained by metrics reflecting land use practices and agricultural dynamics around primary forest patches and that their spatial patterns were not randomly distributed. Forest degradation is mainly driven by fragmentation effects resulting from old deforestation and colonization events linked with cropland expansion (e.g. soybean and maize) coupled with high accessibility to market. To a lesser extent, degradation is driven by recent and ongoing (1985?2015) deforestation and fragmentation in slash-and-burn agricultural areas, characterized by heterogeneous mosaics of pastures and fallow lands combined with high use of fire. Our findings highlight the potential of landscape-level framework and remotely sensed land cover data for a thorough understanding of the distribution of forest degradation across human-modified landscapes. Addressing these spatial determinants by looking at agricultural dynamics beyond forest cover is necessary to improve forest management which has major implications for biodiversity, carbon and other ecosystem services

A Large Gene Network in Immature Erythroid Cells Is Controlled by the Myeloid and B Cell Transcriptional Regulator PU.1

PU.1 is a hematopoietic transcription factor that is required for the development of myeloid and B cells. PU.1 is also expressed in erythroid progenitors, where it blocks erythroid differentiation by binding to and inhibiting the main erythroid promoting factor, GATA-1. However, other mechanisms by which PU.1 affects the fate of erythroid progenitors have not been thoroughly explored. Here, we used ChIP-Seq analysis for PU.1 and gene expression profiling in erythroid cells to show that PU.1 regulates an extensive network of genes that constitute major pathways for controlling growth and survival of immature erythroid cells. By analyzing fetal liver erythroid progenitors from mice with low PU.1 expression, we also show that the earliest erythroid committed cells are dramatically reduced in vivo. Furthermore, we find that PU.1 also regulates many of the same genes and pathways in other blood cells, leading us to propose that PU.1 is a multifaceted factor with overlapping, as well as distinct, functions in several hematopoietic lineages