A physically-based parsimonious hydrological model for flash floods in Mediterranean catchments

A spatially distributed hydrological model, dedicated to flood simulation, is developed on the basis of physical process representation (infiltration, overland flow, channel routing). Estimation of model parameters requires data concerning topography, soil properties, vegetation and land use. Four parameters are calibrated for the entire catchment using one flood event. Model sensitivity to individual parameters is assessed using Monte-Carlo simulations. Results of this sensitivity analysis with a criterion based on the Nash efficiency coefficient and the error of peak time and runoff are used to calibrate the model. This procedure is tested on the Gardon d'Anduze catchment, located in the Mediterranean zone of southern France. A first validation is conducted using three flood events with different hydrometeorological characteristics. This sensitivity analysis along with validation tests illustrates the predictive capability of the model and points out the possible improvements on the model's structure and parameterization for flash flood forecasting, especially in ungauged basins. Concerning the model structure, results show that water transfer through the subsurface zone also contributes to the hydrograph response to an extreme event, especially during the recession period. Maps of soil saturation emphasize the impact of rainfall and soil properties variability on these dynamics. Adding a subsurface flow component in the simulation also greatly impacts the spatial distribution of soil saturation and shows the importance of the drainage network. Measures of such distributed variables would help discriminating between different possible model structures

Vers une méthode de maîtrise des risques dans l'informatisation de l'aide au handicap

National audienceDe nombreux projets visent à améliorer la situation de handicap en utilisant des technologies informatiques. Cela va des interfaces homme-machine pour les polyhandicapés à des outils de gestion des activités pour l'autonomie des autistes en passant par des logiciels d'assistance pour les troubles bipolaires. Cependant, si ces approches sont intéressantes et offrent souvent de bons résultats, les risques d'une assistance informatique dédiée pour le patient, le personnel soignant et l'entourage sont peu pris en considération. En effet, les travaux portent souvent sur les gains et les améliorations obtenus d'un point de vue de l'autonomie mais pas d'un point de vue plus global en terme de rééducation ou d'évolution de la pathologie du patient. Les gains sont souvent en terme d'allègement du suivi médical, social et familial, mais ils ne sont pas envisagés globalement et manquent d'une vision systémique seule à même d'évaluer l'amélioration de l'autonomie et les risques liés à une assistance informatique. Par ailleurs, cette vision se doit de prendre en compte tant les modifications de la place du handicapé au sein de la société que les modifications de celle-ci autour de ces enjeux. Cet article caractérise les risques lors d'une assistance informatique pour des handicaps moteurs et mentaux. Il classifie les approches d'assistance, la nature des risques rencontrés au regard du contexte d'encadrement thérapeutique et définit une méthode pour évaluer et prévenir ces risques. Il propose ainsi un cadre conceptuel d'évaluation globale des risques et des impacts afin de faciliter les expérimentations, l'analyse de ces risques et définir les meilleures pratiques permettant de les contrôler

Применение методов ядерной физики и ускорителей ННЦ ХФТИ для изучения состава, структуры и свойств твердых тел

Излагается применение методов ядерной физики и ускорителей ННЦ ХФТИ для решения научных и технологических задач в области физики металлов, сплавов, полупроводников, металлоксидных и магнитных материалов. Представляются результаты экспериментов по определению концентрации и распределения элементов, выполненных с помощью пучков ионов водорода и гелия, ускоренных в электростатическом ускорителе до энергии 0,5…4,0 МэВ. Для идентификации элементов и изотопов использовались резонансные ядерные реакции, кулоновское и резонансное ядерное рассеяние и возбуждаемое ускоренными частицами характеристическое рентгеновское излучение. Излагаются результаты и возможности применения каналированных частиц и ориентационных эффектов для изучения локализации, структуры, ориентации, образования, распада и аннигиляции простейших дефектов, определения концентрации и распределения дефектов в радиационно нарушенных кристаллах.Викладається застосування методів ядерної фізики і прискорювачів ННЦ ХФТИ для рішення наукових і технологічних задач в області фізики металів, сплавів, напівпровідників, металооксидних та магнітних матеріалів. Приведені результати експерементів з визначення концентрації та розподілу елементів, виконаних за допомогою пучків іонів водню та гелію, що прискорюються в електростатичному прискорювачю до енергії 0,5 - 4,0 МеВ. Для ідентифікації елементів і ізотопів використовувалися резонансні ядерні реакції, кулонівське і резонансне ядерне розсіювання та збуджуване прискореними частками характеристичне рентгенівське випромінюваня. Викладаються результати і можливості застосування часток що каналюють та орієнтаційных ефектів для вивчення локалізації, структури, орієнтації, утворення, розпаду й анігіляції найпростіших дефектів, визначення концентрації і розподілу дефектів у радіаційно порушених кристалах.Nuclear physics methods and use of the NSC KIPT accelerators as applied to scientific and technological problems in the field of physics of metals, alloys, semiconductors, metal oxide and magnetic materials are surveyed. The results of the experiments relevant to determination of element concentration and distribution using 0,5 - 4,0 MeV hydrogen and helium ions of electrostatic accelerator are presented. Resonance nuclear reactions, coulomb and nuclear resonance scattering as well as X-ray radiation were used for element and isotope identification. The possibilities of application of channeling particles and oriented effects for study of localization, structure, orientation, formation, disintegration and annihilation of elementary defects, determination of defect concentration and distribution in radiation disturbed crystals

Strain inhomogeneity in copper islands probed by coherent X-ray diffraction

International audienceThe strain field of individual epitaxial sub-micrometric copper islands is studied using coherent X-ray diffraction and finite element modelling. The strain inhomogeneity in each island is so large that the characteristic features of the island shape tend to disappear in the diffraction pattern, which is dominated by strain effects. The model confirms the tensile strain imposed to the island by the thermal mismatch occurring during the preparation of the samples. An evaluation of the residual strain is obtained by qualitatively fitting the diffraction data

Impact of seawater sulfate concentration on sulfur concentration and isotopic composition in calcite of two cultured benthic foraminifera

Marine sediments can be used to reconstruct the evolution of seawater [SO42-] and δ34S over time, two key parameters that contribute to refine our understanding of the sulfur cycle and thus of Earth's redox state. δ34S evolution can be measured from carbonates, barites and sulfate evaporites. [SO42-] variations can be reconstructed using fluid inclusions in halites, a method that only allows a low-resolution record. Reconstruction of the past sulfur cycle could be improved if carbonates allowed the tracking of both seawater δ34S and [SO42-] variations in a sole, continuous sedimentary repository. However, most primary carbonates formed in the ocean are biogenic, and organisms tend to overprint the geochemical signatures of their carbonates through a combination of processes often collectively referred to as vital effects. Hence, calibrations are needed to allow seawater δ34S and [SO42-] reconstructions based on biogenic carbonates. Because foraminifera are important marine calcifiers, we opted to focus on calcite synthesized by individuals of rosalinid benthic foraminifera cultured in the laboratory under controlled conditions, with varying seawater [SO42-] (ranging from 0 to 180 mM). Our experimental design allowed us to obtain foraminiferal asexual reproduction over several generations. We measured bulk carbonate-associated sulfate (CAS) content and sulfur isotopic composition (δ34SCAS) on samples of tens to hundreds of specimens from a selection of culture media, where [SO42-] varied from 5 to 60 mM. Increasing or decreasing [SO42-] with respect to modern-day seawater concentration (28 mM) impacted foraminiferal population size dynamics and the total amount of bioprecipitated carbonate. Foraminiferal CAS concentration increased proportionally with [SO42-] concentration from 5 mM up to 28 mM and then showed a plateau from 28 to 60 mM. The existence of a threshold at 28 mM is interpreted as the result of a control on the precipitation fluid chemistry that foraminifera exert on the carbonate precipitation loci. However, at high seawater sulfate concentrations (&gt; 40 mM) the formation of sulfate complexes with other cations may partially contribute to the non-linearity of the CAS concentration in foraminiferal tests at high increases in [SO42-]. Yet, despite the significant effect of seawater [SO42-] on foraminiferal reproduction and on CAS incorporation, the isotopic fractionation between CAS and seawater remains stable through varying seawater [SO42-]. Altogether, these results illustrate that CAS in biogenic calcite could constitute a good proxy for both seawater [SO42-] and δ34S and suggests that sulfate likely plays a role in foraminiferal biomineralization and biological activity.</p

Resident macrophages influence stem cell activity in the mammary gland

Introduction Macrophages in the mammary gland are essential for morphogenesis of the ductal epithelial tree and have been implicated in promoting breast tumor metastasis. Although it is well established that macrophages influence normal mammopoiesis, the mammary cell types that these accessory cells influence have not been determined. Here we have explored a role for macrophages in regulating mammary stem cell (MaSC) activity, by assessing the ability of MaSCs to reconstitute a mammary gland in a macrophage-depleted fat pad. Methods Two different in vivo models were used to deplete macrophages from the mouse mammary fat pad, allowing us to examine the effect of macrophage deficiency on the mammary repopulating activity of MaSCs. Both the Csf1(op/op) mice and clodronate liposome-mediated ablation models entailed transplantation studies using the MaSC-enriched population. Results We show that mammary repopulating ability is severely compromised when the wild-type MaSC-enriched subpopulation is transplanted into Csf1(op/op) fat pads. In reciprocal experiments, the MaSC-enriched subpopulation from Csf1(op/op) glands had reduced regenerative capacity in a wildtype environment. Utilizing an alternative strategy for selective depletion of macrophages from the mammary gland, we demonstrate that co-implantation of the MaSC-enriched subpopulation with clodronate-liposomes leads to a marked decrease in repopulating frequency and outgrowth potential. Conclusions Our data reveal a key role for mammary gland macrophages in supporting stem/progenitor cell function and suggest that MaSCs require macrophage-derived factors to be fully functional. Macrophages may therefore constitute part of the mammary stem cell nich

ROAST: rotation gene set tests for complex microarray experiments

Motivation: A gene set test is a differential expression analysis in which a P-value is assigned to a set of genes as a unit. Gene set tests are valuable for increasing statistical power, organizing and interpreting results and for relating expression patterns across different experiments. Existing methods are based on permutation. Methods that rely on permutation of probes unrealistically assume independence of genes, while those that rely on permutation of sample are suitable only for two-group comparisons with a good number of replicates in each group

Деякі проблеми використання тимчасово зайнятих земель

<div><p>Glucocorticoid induced-leucine zipper (GILZ) has been shown to be induced in cells by different stimuli such as glucocorticoids, IL-10 or deprivation of IL-2. GILZ has anti-inflammatory properties and may be involved in signalling modulating apoptosis. Herein we demonstrate that wildtype <em>Yersinia enterocolitica</em> which carry the pYV plasmid upregulated GILZ mRNA levels and protein expression in epithelial cells. Infection of HeLa cells with different <em>Yersinia</em> mutant strains revealed that the protease activity of YopT, which cleaves the membrane-bound form of Rho GTPases was sufficient to induce GILZ expression. Similarly, <em>Clostridium difficile</em> toxin B, another bacterial inhibitor of Rho GTPases induced GILZ expression. YopT and toxin B both increased transcriptional activity of the GILZ promoter in HeLa cells. GILZ expression could not be linked to the inactivation of an individual Rho GTPase by these toxins. However, forced expression of RhoA and RhoB decreased basal <em>GILZ</em> promoter activity. Furthermore, MAPK activation proved necessary for profound GILZ induction by toxin B. Promoter studies and gel shift analyses defined binding of upstream stimulatory factor (USF) 1 and 2 to a canonical c-Myc binding site (E-box) in the <em>GILZ</em> promoter as a crucial step of its trans-activation. In addition we could show that USF-1 and USF-2 are essential for basal as well as toxin B induced GILZ expression. These findings define a novel way of <em>GILZ</em> promoter trans-activation mediated by bacterial toxins and differentiate it from those mediated by dexamethasone or deprivation of IL-2.</p> </div