5,053 research outputs found

    Les services intensifs : une nouvelle approche dans l’intervention auprès des familles à risque

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    L'augmentation du nombre de placements d'enfants et l'échec relatif de cette mesure dans le traitement des problèmes familiaux amènent les professionnels des services sociaux à réfléchir sur de nouvelles façons d'aider les familles à résoudre leurs difficultés tout en maintenant l'unité familiale intacte. Les services intensifs à la famille appartiennent à ce courant de renouveau. Le présent article décrit cette nouvelle forme d'intervention. Plus précisément, trois grands thèmes sont abordés. Le premier porte sur l'historique de ces programmes, leur philosophie et leurs principes, de même que sur les trois principaux modèles mis en oeuvre sous le vocable des services intensifs à la famille, soit les programmes Homebuilders, Familieset Family Treatment. Dans un second temps, l'efficacité des programmes de sauvegarde de la famille est examinée en apportant une attention particulière aux problèmes méthodologiques que soulève leur évaluation. L'article se termine par une présentation des conditions nécessaires à l'implantation de ces programmes dans les services sociaux québécois

    Mining XML Documents

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    XML documents are becoming ubiquitous because of their rich and flexible format that can be used for a variety of applications. Giving the increasing size of XML collections as information sources, mining techniques that traditionally exist for text collections or databases need to be adapted and new methods to be invented to exploit the particular structure of XML documents. Basically XML documents can be seen as trees, which are well known to be complex structures. This chapter describes various ways of using and simplifying this tree structure to model documents and support efficient mining algorithms. We focus on three mining tasks: classification and clustering which are standard for text collections; discovering of frequent tree structure which is especially important for heterogeneous collection. This chapter presents some recent approaches and algorithms to support these tasks together with experimental evaluation on a variety of large XML collections

    Covoiturage et territoire : quelle(s) proximité (s) dans la mobilité ?

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    International audienceCarpooling, as other shared uses for travelling, is growing for both economical and ideological reasons. Firstly related to long journey, this growth is now concerning average distance trips, especially in suburban areas. Suburbs are known for being automobile-oriented territories, structured by a sole travel mode, considered responsible for their unsustainability, their lack of social cohesion and functional efficiency. After exploratory research on the spatiality of social relations involved in shared use of cars, we are showing that carpooling jointly queried social cohesion and spatial organisation made in mobility. Producing new social and spatial convergences, these shared practices also reflect a capacity to create social organisations to face suburban liveability problems. These new uses suggest the possibility of “living together with and by networks” that questions suburban territoriality.Le covoiturage, comme d’autres modes de déplacement partagé, connaît un développement important, pour des raisons à la fois économiques et idéologiques. Concernant d’abord les trajets longue distance, cette croissance touche désormais ceux de moyenne distance, notamment au sein des espaces périurbains. Or ces espaces sont avant tout réputés pour les pratiques automobiles et individuelles qui les structurent, et ainsi mettent en cause leur durabilité, leur cohésion sociale et fonctionnelle. Suite à des recherches exploratoires sur la spatialité des rapports sociaux engagés dans les pratiques de co-déplacement, nous montrons que le covoiturage interroge conjointement la cohésion sociale et la structuration spatiale issue de la mobilité. Productrices de nouvelles convergences sociales et spatiales, ces pratiques témoignent d’une capacité d’organisation des acteurs sociaux face au problème de l’habiter périurbain. Elles suggèrent la possibilité d’un « vivre ensemble par et dans les réseaux » qui interpelle la question de la territorialité périurbaine

    Quality of roof harvested rainwater from houses in Île-de-France area, France

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    International audienceBacteriological and physico-chemical water quality parameters were measured in rainwater from 10 harvesting tanks, belonging to two types of rainwater harvesting systems (outside tanks for garden watering and underground tanks for both outdoor and indoor uses) in Île-de-France area (France). The presence of fecal coliforms, enterococci, Pseudomonas spp., coliforms, total flora at 22°C and 36°C and total DAPI direct counts showed a microbiological contamination in water and sediment samples for both tank types. However, the harvested rainwater quality suited some existing water quality guidelines for different non-potable purposes (bathing water or reused wastewater). To our knowledge, the presence of microorganisms in sediment compartment in rainwater harvesting tank has been studied for the first time here. Results showed that the sediment could be a reservoir of re-contamination for some microbial species, which would survive in the sediment and may be resuspended in the water column. In parallel, physical-chemical parameters (temperature, turbidity, conductivity, pH and dissolved organic carbon) of collected rainwater were found in the ranges reported in the literature. Algal blooms, principally green algae, occurred in the outside tanks during spring and summer as shown by the high chlorophyll levels (the highest chlorophyll content reached 209.8 µg/L with a water pH of 9.37). Nitrate and phosphate concentrations in water samples were low (respectively less than 5 mg/L and 0.5 mg/L) but high enough to support the development of microorganisms and especially photosynthetic microorganisms in the outside tanks. The difficulty to evaluate the microbial quality of roof-harvested rainwater due to the lack of suitable quality standards is underlined. Depending on the usage of the harvested rainwater, some treatments may be needed to get a better microbial quality and direct measurements for pathogens may be also needed to establish whether or not such harvested rainwater is safe for different types of uses

    A New Human NHERF1 Mutation Decreases Renal Phosphate Transporter NPT2a Expression by a PTH-Independent Mechanism

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    Background: The sodium-hydrogen exchanger regulatory factor 1 (NHERF1) binds to the main renal phosphate transporter NPT2a and to the parathyroid hormone (PTH) receptor. We have recently identified mutations in NHERF1 that decrease renal phosphate reabsorption by increasing PTH-induced cAMP production in the renal proximal tubule. Methods: We compared relevant parameters of phosphate homeostasis in a patient with a previously undescribed mutation in NHERF1 and in control subjects. We expressed the mutant NHERF1 protein in Xenopus Oocytes and in cultured cells to study its effects on phosphate transport and PTH-induced cAMP production. Results: We identified in a patient with inappropriate renal phosphate reabsorption a previously unidentified mutation (E68A) located in the PDZ1 domain of NHERF1.We report the consequences of this mutation on NHERF1 function. E68A mutation did not modify cAMP production in the patient. PTH-induced cAMP synthesis and PKC activity were not altered by E68A mutation in renal cells in culture. In contrast to wild-type NHERF1, expression of the E68A mutant in Xenopus oocytes and in human cells failed to increase phosphate transport. Pull down experiments showed that E68A mutant did not interact with NPT2a, which robustly interacted with wild type NHERF1 and previously identified mutants. Biotinylation studies revealed that E68A mutant was unable to increase cell surface expression of NPT2a. Conclusions: Our results indicate that the PDZ1 domain is critical for NHERF1- NPT2a interaction in humans and for th

    Animal gaits from video

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    International audienceWe present a method for animating 3D models of animals from existing live video sequences such as wild life documentaries. Videos are first segmented into binary images on which Principal Component Analysis (PCA) is applied. The time-varying coordinates of the images in the PCA space are then used to generate 3D animation. This is done through interpolation with Radial Basis Functions (RBF) of 3D pose examples associated with a small set of key-images extracted from the video. In addition to this processing pipeline, our main contributions are: an automatic method for selecting the best set of key-images for which the designer will need to provide 3D pose examples. This method saves user time and effort since there is no more need for manual selection within the video and then trials and errors in the choice of key-images and 3D pose examples. As another contribution, we propose a simple algorithm based on PCA images to resolve 3D pose prediction ambiguities. These ambiguities are inherent to many animal gaits when only monocular view is available. The method is first valuated on sequences of synthetic images of animal gaits, for which full 3D data is available. We achieve a good quality reconstruction of the input 3D motion from a single video sequence of its 2D rendering. We then illustrate the method by reconstructing animal gaits from live video of wild life documentaries

    Decoupling of arsenic and iron release from ferrihydrite suspension under reducing conditions: a biogeochemical model

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    High levels of arsenic in groundwater and drinking water are a major health problem. Although the processes controlling the release of As are still not well known, the reductive dissolution of As-rich Fe oxyhydroxides has so far been a favorite hypothesis. Decoupling between arsenic and iron redox transformations has been experimentally demonstrated, but not quantitatively interpreted. Here, we report on incubation batch experiments run with As(V) sorbed on, or co-precipitated with, 2-line ferrihydrite. The biotic and abiotic processes of As release were investigated by using wet chemistry, X-ray diffraction, X-ray absorption and genomic techniques. The incubation experiments were carried out with a phosphate-rich growth medium and a community of Fe(III)-reducing bacteria under strict anoxic conditions for two months. During the first month, the release of Fe(II) in the aqueous phase amounted to only 3% to 10% of the total initial solid Fe concentration, whilst the total aqueous As remained almost constant after an initial exchange with phosphate ions. During the second month, the aqueous Fe(II) concentration remained constant, or even decreased, whereas the total quantity of As released to the solution accounted for 14% to 45% of the total initial solid As concentration. At the end of the incubation, the aqueous-phase arsenic was present predominately as As(III) whilst X-ray absorption spectroscopy indicated that more than 70% of the solid-phase arsenic was present as As(V). X-ray diffraction revealed vivianite Fe(II)3(PO4)2.8H2O in some of the experiments. A biogeochemical model was then developed to simulate these aqueous- and solid-phase results. The two main conclusions drawn from the model are that (1) As(V) is not reduced during the first incubation month with high Eh values, but rather re-adsorbed onto the ferrihydrite surface, and this state remains until arsenic reduction is energetically more favorable than iron reduction, and (2) the release of As during the second month is due to its reduction to the more weakly adsorbed As(III) which cannot compete against carbonate ions for sorption onto ferrihydrite. The model was also successfully applied to recent experimental results on the release of arsenic from Bengal delta sediments

    A Novel fry1 Allele Reveals the Existence of a Mutant Phenotype Unrelated to 5′->3′ Exoribonuclease (XRN) Activities in Arabidopsis thaliana Roots

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    BACKGROUND Mutations in the FRY1/SAL1 Arabidopsis locus are highly pleiotropic, affecting drought tolerance, leaf shape and root growth. FRY1 encodes a nucleotide phosphatase that in vitro has inositol polyphosphate 1-phosphatase and 3',(2'),5'-bisphosphate nucleotide phosphatase activities. It is not clear which activity mediates each of the diverse biological functions of FRY1 in planta. PRINCIPAL FINDINGS A fry1 mutant was identified in a genetic screen for Arabidopsis mutants deregulated in the expression of Pi High affinity Transporter 1;4 (PHT1;4). Histological analysis revealed that, in roots, FRY1 expression was restricted to the stele and meristems. The fry1 mutant displayed an altered root architecture phenotype and an increased drought tolerance. All of the phenotypes analyzed were complemented with the AHL gene encoding a protein that converts 3'-polyadenosine 5'-phosphate (PAP) into AMP and Pi. PAP is known to inhibit exoribonucleases (XRN) in vitro. Accordingly, an xrn triple mutant with mutations in all three XRNs shared the fry1 drought tolerance and root architecture phenotypes. Interestingly these two traits were also complemented by grafting, revealing that drought tolerance was primarily conferred by the rosette and that the root architecture can be complemented by long-distance regulation derived from leaves. By contrast, PHT1 expression was not altered in xrn mutants or in grafting experiments. Thus, PHT1 up-regulation probably resulted from a local depletion of Pi in the fry1 stele. This hypothesis is supported by the identification of other genes modulated by Pi deficiency in the stele, which are found induced in a fry1 background. CONCLUSIONS/SIGNIFICANCE Our results indicate that the 3',(2'),5'-bisphosphate nucleotide phosphatase activity of FRY1 is involved in long-distance as well as local regulatory activities in roots. The local up-regulation of PHT1 genes transcription in roots likely results from local depletion of Pi and is independent of the XRNs.This work was supported by an ANR-GENOPLANT grant (RIBOROOT-ANR06 GPLA 011) and the CEA agency. Array hybridizations have been partly supported by RNG (Réseau National des Génopoles, Evry, France). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No additional external funding received for this study

    Phosphate Import in Plants: Focus on the PHT1 Transporters

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    The main source of phosphorus for plants is inorganic phosphate (Pi), which is characterized by its poor availability and low mobility. Uptake of this element from the soil relies heavily upon the PHT1 transporters, a specific family of plant plasma membrane proteins that were identified by homology with the yeast PHO84 Pi transporter. Since the discovery of PHT1 transporters in 1996, various studies have revealed that their function is controlled by a highly complex network of regulation. This review will summarize the current state of research on plant PHT1 multigenic families, including physiological, biochemical, molecular, cellular, and genetics studies
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