pinecone/core-2020-05-10-deduplication huggingface dataset:
RFID interactive tabletop application with tangible objects: exploratory study to observe young children’ behaviors

International audienceNumerous academic and industrial studies and developments concerning interactive tabletops are paving the way for new educational applications. We have developed an interactive tabletop application equipped with RFID technology. This tabletop, called TangiSense, is based on a Multi-Agent System that allows users to associate information with behaviors to manipulate tangible objects. The application involves the recognition of basic colors. With the application, children are required to manipulate tangible objects. Their task involves recognizing objects that have "lost" their dominant color and placing these objects in appropriate colored areas. A tangible magician object automatically analyzes the filled zones and provides children and their teacher with virtual and vocal feedback. This application has been evaluated in a field study with children 3 to 5 years of age. The initial results are promising and show that such an application can support interaction and collaboration, and subsequently educational situations, among young children
Postpartum hemorrhage resulting from uterine atony after vaginal delivery: factors associated with severity.
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Factors associated with postpartum hemorrhage severity

International audienceOBJECTIVE: To identify factors associated with severity of postpartum hemorrhage among characteristics of women and their delivery, the components of initial postpartum hemorrhage management, and the organizational characteristics of maternity units. METHODS: This population-based cohort study included women with postpartum hemorrhage due to uterine atony after vaginal delivery in 106 French hospitals between December 2004 and November 2006 (N=4,550). Severe postpartum hemorrhage was defined by a peripartum change in hemoglobin of 4 g/dL or more. A multivariable logistic model was used to identify factors independently associated with postpartum hemorrhage severity. RESULTS: Severe postpartum hemorrhage occurred in 952 women (20.9%). In women with postpartum hemorrhage, factors independently associated with severity were: primiparity; previous postpartum hemorrhage; previous cesarean delivery; cervical ripening; prolonged labor; and episiotomy; and delay in initial care for postpartum hemorrhage. Also associated with severity was 1) administration of oxytocin more than 10 minutes after postpartum hemorrhage diagnosis: 10-20 minutes after, proportion with severe postpartum hemorrhage 24.6% compared with 20.5%, adjusted OR 1.38, 95% CI 1.03-1.85; more than 20 minutes after, 31.8% compared with 20.5%, adjusted OR 1.86, CI 1.45-2.38; 2) manual examination of the uterine cavity more than 20 minutes after (proportion with severe postpartum hemorrhage 28.2% versus 20.7%, adjusted OR 1.83, 95% CI 1.42-2.35); 3) call for additional assistance more than 10 minutes after (proportion with severe postpartum hemorrhage 29.8% versus 24.8%, adjusted OR 1.61, 95% CI 1.23-2.12 for an obstetrician, and 35.1% compared with 29.9%, adjusted OR 1.51, 95% CI 1.14-2.00 for an anesthesiologist); 4) and delivery in a public non-university hospital. Epidural analgesia was found to be a protective factor against severe blood loss in women with postpartum hemorrhage. CONCLUSION: Aspects of labor, delivery, and their management; delay in initial care; and place of delivery are independent risk factors for severe blood loss in women with postpartum hemorrhage caused by atony
Influence of initial mean helicity on homogeneous turbulent shear flow

International audienceHelicity statistics are studied in homogeneous turbulent shear flow. Initial mean helicity is imposed on an isotropic turbulence field using a decomposition of the flow into complex-valued helical waves. The initial decay of the turbulent kinetic energy is weakened in the presence of strong mean helicity, consistent with an analytic analysis of the spectral tensor of velocity correlations. While exponential growth of the mean turbulent kinetic energy is obtained, the mean helicity decays. Probability distribution functions (PDFs) of helicity are skewed and show that the imposed mean helicity prevails throughout the simulations. A wavelet-based scale-dependent analysis shows a trend to two dimensionalization for large scales of motion and a preference for helical motion at small scales. The magnitude of the skewness of the PDFs decreases for smaller scales. Joint PDFs indicate a strong correlation of the signs of both, helicity and superhelicity, for all cases. This correlation supports the conjecture that superhelicity dissipates helicity
Transition to turbulence through steep global-modes cascade in an open rotating cavity

International audienceThe transition to turbulence in a rotating boundary layer is analysed via direct numerical simulation (DNS) in an annular cavity made of two parallel corotating discs of finite radial extent, with a forced inflow at the hub and free outflow at the rim. In a former numerical investigation (Viaud, Serre & Chomaz J. Fluid Mech., vol. 598, 2008, pp. 451-464) realized in a sectorial cavity of azimuthal extent 2p68, we have established the existence of a primary bifurcation to nonlinear global mode with angular phase velocity and radial envelope coherent with the so-called elephant mode theory. The former study has demonstrated the subcritical nature of this primary bifurcation with a base flow that keeps being linearly stable for all Reynolds numbers studied. The present work investigates the stability of this elephant mode by extending the cavity both in the radial and azimuthal direction. When the Reynolds number based on the forced throughflow is increased above a threshold value for the existence of the nonlinear global mode, a large-amplitude impulsive perturbation gives rise to a self-sustained saturated wave with characteristics identical to the 68-fold global elephant mode obtained in the smaller cavity. This saturated wave is itself globally unstable and a second front appears in the lee of the primary where small-scale instability develops. These secondary instabilities are identical for the 2p/68 and the 2p/4 long sectorial cavities, indicating that transition involves a Floquet mode of zero azimuthal wavenumber. This secondary instability leads to a very disorganized state, defining the transition to turbulence. The observed transition to turbulence linked to the secondary instability of a global mode confirms, for the first time on a real flow, the possibility of a direct transition to turbulence through an elephant mode cascade, a scenario that was up to now only observed on the Ginzburg-Landau model. © 2011 Cambridge University Press
Comparison of photosynthesis and antioxidant performance of several Citrus and Fortunella species (Rutaceae) under natural chilling stress

International audienceCitrus plants originate from southeastern Asia, in a large area with various climates characterized by a broad range of temperatures. Some species have been diversified in temperate climates, others in subtropical climates. Temperature is assumed to be a key factor in citrus species adaptation and diversification of basic cellular functions. In a field experiment, the tolerance of the three fundamental Citrus species C. medica L., C. reticulata Blanco and C. maxima (Burm.) Merr., and Fortunella japonica (Thunb.) Swing. to photooxidative stress caused by seasonal climatic changes was evaluated on adult trees by measuring net photosynthesis (Pnet), stomatal conductance (Gs), maximum photosynthesis (Pmax) and chlorophyll fluorescence (Fv/Fm). In addition, seasonal changes in oxidative status, antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase and glutathione reductase) and antioxidant metabolites (ascorbate and glutathione) were monitored. Mandarin and pummelo appeared to be the most tolerant, showing the lowest down-regulation of photosynthetic parameters, and the lowest accumulation of oxidized compounds associated with efficiency of their antioxidant system. Kumquat showed intermediate behaviour, with a large diminution of photosynthetic parameters and marked accumulation of hydrogen peroxide, whereas the malondialdehyde content remained low, with a strong induction of glutathione synthesis. Finally, citron appeared to be the most sensitive genotype with a marked decrease in photosynthetic performance, the largest accumulation of oxidative parameters, insufficient induction of antioxidant enzymes and down-regulation of ascorbate and glutathione synthesis
Organometallic precursors as catalyst to grow three dimensional micro/nano structures: spheres, clusters and wires

International audienceThis paper presents the growth and characterization of three-dimensional structures using metal-organic (or organometallic) chemical precursors like M(CH3)3, where M is a metal. Their morphology depends principally on growth temperature and conditions at the surface of the substrate. These 3D structures can be separated into two classes: i) one with (Ga, Al, In) metallic alloys shaped as sphere, sceptre or cylinder and a carbon membrane covering the alloy; ii) other with semiconductor or oxide nanowires capped by a metallic sphere. The metal-organic precursors can be seen as catalysts molecules that grow semiconductors with micro and nano-structures similar to the role of gold particles used to grow nanowires in the VLS mechanism. We present the MOCVD growth of Ga2O3, CuGaxOyand (Ga,In)P nanowires using the metal-organic precursors on metallic or metal containing substrates
Precession, nutation, and space geodetic determination of the Earth's variable gravity field

International audiencePrecession and nutation of the Earth depend on the Earth's dynamical flattening, H, which is closely related to the second degree zonal coefficient, J2 of the geopotential. A small secular decrease as well as seasonal variations of this coefficient have been detected by precise measurements of artificial satellites (Nerem et al. 1993; Cazenave et al. 1995) which have to be taken into account for modelling precession and nutation at a microarcsecond accuracy in order to be in agreement with the accuracy of current VLBI determinations of the Earth orientation parameters. However, the large uncertainties in the theoretical models for these J2 variations (for example a recent change in the observed secular trend) is one of the most important causes of why the accuracy of the precession-nutation models is limited (Williams 1994; Capitaine et al. 2003). We have investigated in this paper how the use of the variations of J2 observed by space geodetic techniques can influence the theoretical expressions for precession and nutation. We have used time series of J2 obtained by the "Groupe de Recherches en Géodésie spatiale" (GRGS) from the precise orbit determination of several artificial satellites from 1985 to 2002 to evaluate the effect of the corresponding constant, secular and periodic parts of H and we have discussed the best way of taking the observed variations into account. We have concluded that, although a realistic estimation of the J2 rate must rely not only on space geodetic observations over a limited period but also on other kinds of observations, the monitoring of periodic variations in J2 could be used for predicting the effects on the periodic part of the precession-nutation motion
Mid- and Far-Infrared Marker Bands of the Metal Coordination Sites of the Histidine Side Chains in the Protein Cu,Zn-Superoxide Dismutase

International audienceVibrational spectroscopy gives important information on the properties of ligand and metal–ligand bonds in metalloenzymes. Infrared spectroscopy is appealing for the study of metal active sites that are not amenable to Raman spectroscopy. We present a combined experimental and theoretical approach to analyze the mid- and far-IR spectra of Cu,Zn-superoxide dismutase (Cu,Zn-SOD) as a probe of the histidine ligands. This metalloenzyme provides a unique model to identify specific IR signatures of metal–histidine coordination and to study their alterations as a function of the metal (copper/zinc), the copper valence state (+I/+II), the histidine coordination mode (Nτ and Nπ) and the histidine protonation state. DFT calculations combined with normal mode descriptions from potential energy distribution calculations were performed on two slightly different cluster models. Differences in the constraints at the side chain of one histidine Cu ligand sensibly modify the geometric parameters and vibrational properties. Electrochemically induced FTIR difference spectroscopy provided mid- and far-IR fingerprint spectra of the Cu protein in aqueous media that are sensitive to the redox state of the Cu centre at the active site. Comparisons of the DFT predictions with the experimental IR modes of the histidine ligands at the Cu,Zn-SOD active site showed that useful mid-IR markers of histidine Nτ and Nπ coordination were predicted with good accuracy. The DFT analysis further demonstrated a link between the ν(C4–C5) mode frequency of His46 and the specific properties of the His46–Cu bond in Cu,Zn-SOD. A combined theoretical and experimental approach on samples in H2O and 2H2O or 15N-labelled samples identified the contributions from the histidine side chain modes in the 669–629 cm–1 region
Sparsity and the Bayesian Perspective

International audienceSparsity has recently been introduced in cosmology for weak-lensing and cosmic microwave background (CMB) data analysis for different applications such as denoising, component separation, or inpainting (i.e., filling the missing data or the mask). Although it gives very nice numerical results, CMB sparse inpainting has been severely criticized by top researchers in cosmology using arguments derived from a Bayesian perspective. In an attempt to understand their point of view, we realize that interpreting a regularization penalty term as a prior in a Bayesian framework can lead to erroneous conclusions. This paper is by no means against the Bayesian approach, which has proven to be very useful for many applications, but warns against a Bayesian-only interpretation in data analysis, which can be misleading in some cases
Extraction of the homogeneous linewidth of the spectrally diffusing line of a CdSe/ZnSe quantum dot embedded in a nanowire

International audienceWe present a simple method to extract the homogeneous linewidth of a single photon emitter line exhibiting fast (down to 1 ns) spectral diffusion (SD). It is based on a recently developed technique using photon correlation measurements on half of the line. Here we show that the SD induced bunching depends on the ratio between the width of the homogeneous line and the spectral diffusion amplitude. Using this technique on a CdSe/ZnSe quantum dot, we investigate the temperature dependence of its fast SD amplitude and its homogeneous excitonic linewidt
Thermodynamics of MHD flows with axial symmetry

We present strategies based upon extremization principles, in the case of the axisymmetric equations of magnetohydrodynamics (MHD). We study the equilibrium shape by using a minimum energy principle under the constraints of the MHD axisymmetric equations. We also propose a numerical algorithm based on a maximum energy dissipation principle to compute in a consistent way the equilibrium states. Then, we develop the statistical mechanics of such flows and recover the same equilibrium states giving a justification of the minimum energy principle. We find that fluctuations obey a Gaussian shape and we make the link between the conservation of the Casimirs on the coarse-grained scale and the process of energy dissipation
Evolution of the specific star formation rate function at z< 1.4   Dissecting the mass-SFR plane in COSMOS and GOODS

International audienceThe relation between the stellar mass (M⋆) and the star formation rate (SFR) characterizes how the instantaneous star formation is determined by the galaxy past star formation history and by the growth of the dark matter structures. We deconstruct the M⋆-SFR plane by measuring the specific SFR functions in several stellar mass bins from z = 0.2 out to z = 1.4 (specific SFR = SFR/M⋆, noted sSFR). Our analysis is primary based on a 24 μm selected catalogue combining the COSMOS and GOODS surveys. We estimate the SFR by combining mid- and far-infrared data for 20500 galaxies. The sSFR functions are derived in four stellar mass bins within the range 9.5 < log (M⋆ /M⊙) < 11.5. First, we demonstrate the importance of taking into account selection effects when studying the M⋆-SFR relation. Secondly, we find a mass-dependent evolution of the median sSFR with redshift varying as sSFR ∝ (1 + z)b, with b increasing from b = 2.88±0.12 to b = 3.78± 0.60 between M⋆ = 109.75 M⊙ and M⋆ = 1011.1 M⊙, respectively. At low masses, this evolution is consistent with the cosmological accretion rate and predictions from semi-analytical models (SAM). This agreement breaks down for more massive galaxies showing the need for a more comprehensive description of the star formation history in massive galaxies. Third, we obtain that the shape of the sSFR function is invariant with time at z< 1.4 but depends on the mass. We observe a broadening of the sSFR function ranging from 0.28 dex at M⋆ = 109.75 M⊙ to 0.46 dex at M⋆ = 1011.1 M⊙. Such increase in the intrinsic scatter of the M⋆-SFR relation suggests an increasing diversity ofstar formation histories (SFHs) as the stellar mass increases. Finally, we find a gradual decline of the sSFR with stellar mass as log 10(sSFR) ∝ −0.17M⋆. We discuss the numerous physical processes, as gas exhaustion in hot gas halos or secular evolution, which can gradually reduce the sSFR and increase the SFH diversity
Inferring transit time distributions from atmospheric tracer data: Assessment of the predictive capacities of Lumped Parameter Models on a 3D crystalline aquifer model

International audienceWhile central in groundwater resources and contaminant fate, Transit Time Distributions (TTDs) are never directly accessible from field measurements but always deduced from a combination of tracer data and more or less involved models. We evaluate the predictive capabilities of approximate distributions (Lumped Parameter Models abbreviated as LPMs) instead of fully developed aquifer models. We develop a generic assessment methodology based on synthetic aquifer models to establish references for observable quantities as tracer concentrations and prediction targets as groundwater renewal times. Candidate LPMs are calibrated on the observable tracer concentrations and used to infer renewal time predictions, which are compared with the reference ones. This methodology is applied to the produced crystalline aquifer of Plœmeur (Brittany, France) where flows leak through a micaschists aquitard to reach a sloping aquifer where they radially converge to the producing well, issuing broad rather than multi-modal TTDs. One, two and three parameters LPMs were calibrated to a corresponding number of simulated reference anthropogenic tracer concentrations (CFC- 11, 85Kr and SF6). Extensive statistical analysis over the aquifer shows that a good fit of the anthropogenic tracer concentrations is neither a necessary nor a sufficient condition to reach acceptable predictive capability. Prediction accuracy is however strongly conditioned by the use of a priori relevant LPMs. Only adequate LPM shapes yield unbiased estimations. In the case of Plœmeur, relevant LPMs should have two parameters to capture the mean and the standard deviation of the residence times and cover the first few decades [0;50 years]. Inverse Gaussian and shifted exponential performed equally well for the wide variety of the reference TTDs from strongly peaked in recharge zones where flows are diverging to broadly distributed in more converging zones. When using two sufficiently different atmospheric tracers like CFC-11 and 85Kr, groundwater renewal time predictions are accurate at 1 to 5 years for estimating mean transit times of some decades (10-50 years). 1-parameter LPMs calibrated on a single atmospheric tracer lead to substantially larger errors of the order of 10 years, while 3-parameter LPMs calibrated with a third atmospheric tracers (SF6) do not improve the prediction capabilities. Based on a specific site, this study highlights the high predictive capacities of two atmospheric tracers on the same time range with sufficiently different atmospheric concentration chronicles
Role of goethite during air-oxidation of PAH-contaminated soils

International audienceThe impact of goethite on air-oxidation of PAH-contaminated soils was studied through two sets of experiments. (i) Soil extractable organic matter (EOM) and (ii) whole coking plant soils were oxidized at 60 and 100 °C for 160 d, with/without goethite. Organic matter (OM) mineralization was monitored via CO2 production and polycyclic aromatic compounds (PACs) oxidation was investigated by GC–MS analyses. The decrease in EOM and PAH contents, and the oxygenated-PAC production observed during EOM oxidation, were enhanced by the presence of goethite. PACs were likely transformed at the goethite surface through electron transfer process. Mass carbon balance revealed a transfer from EOM to the insoluble organic fraction indicating condensation/polymerization of organics. Soil oxidation induced a decrease in EOM, PAH but also in oxygenated-PAC contents, underscoring different oxidation or polymerization behavior in soil. The goethite addition had a lesser impact suggesting that indigenous minerals played an important role in PAC oxidation
An overview of the ACE-2 CLOUDYCOLUMN closure experiment

International audienceCLOUDYCOLUMN is one of the 6 ACE-2 projects which took place in June-July 1997, between Portugal and the Canary Islands. It was specifically dedicated to the study of changes of cloud radiative properties resulting from changes in the properties of those aerosols which act as cloud condensation nuclei. This process is also refered to as the aerosol indirect effect on climate. CLOUDYCOLUMN is focused on the contribution of stratocumulus clouds to that process. In addition to the basic aerosol measurements performed at the ground stations of the ACE-2 project, 5 instrumented aircraft carried out in situ characterization of aerosol physical, chemical and nucleation properties and cloud dynamical and microphysical properties. Cloud radiative properties were also measured remotely with radiometers and a lidar. 11 case studies have been documented, from pure marine to significantly polluted air masses. The simultaneity of the measurements with the multi-aircraft approach provides a unique data set for closure experiments on the aerosol indirect effect. In particular CLOUDYCOLUMN provided the 1st experimental evidence of the existence of the indirect effect in boundary layer clouds forming in polluted continental outbreacks. This paper describes the objectives of the project, the instrumental setup and the sampling strategy. Preliminary results published in additional papers are briefly summarized
Femtosecond time resolved CARS spectroscopy of H2-N2 mixtures in the Dicke regime: Experiments and modeling of velocity effects

International audienceIn this paper, we present measurements and modeling of femtosecond time resolved CARS signal in H2-N2 mixtures at low densities. Three approaches have been used to model the CARS response. The first is the usual sum of Voigt profiles. In the second approach, the speed dependent Voigt profile is used. In the last approach, a new model of the CARS signal is developed which takes into account the velocity changes induced by collisions and the speed dependence of the collisional parameters. The velocity changes are modeled using the Keilson and Storer memory function; the radiator speed dependences of the collisional parameters are determined from their temperature dependences. The results show that the changes of the velocity have important effects for the H2/N2 system at the Dicke density regime