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Vivre avec un livret A. Analyse d'un dispositif d'inclusion bancaire
No full textLa Banque Postale met à disposition de toute la population certains services de base via le livret A dit « d’accessibilité bancaire ». Et elle reçoit pour cela une compensation financière proportionnée de la mission de service d’intérêt économique général qui lui est confiée.A l’heure du développement des offres de (néo-)banques en ligne, du web marchand, des nouvelles formes de crédit, à l’heure du reflux du paiement en argent liquide, nous avons enquêté auprès des usagers et usagères du livret, de façon à répondre aux questions suivantes : - Comment les usagers et usagères envisagent le monde bancaire? - Comment jugent-ils leur bancarisation via le Livret A?- Comment le dispositif livret A construit/contraint leur gestion budgétaire ?- Comment ils s'en satisfont et/ou le combinent à d'autres formes de bancarisation
Stress Release–Induced Suction in Unsaturated MX80 Bentonite Pellet and Powder Mixtures
No full textInternational audienceIn this study, a series of suction-control oedometer tests were conducted on unsaturated and saturated MX80 bentonite pellet/powder mixtures. The mixture samples were imposed with various suctions from 0 to 113 MPa under a low vertical stress (0.1 MPa). Then, the mixture samples were loaded in steps with controlled suction until reaching three different target stresses σv (0.1, 3.2, and 12.8 MPa) and instantaneously unloaded. The microstructure of unloaded samples was observed with mercury intrusion porosimetry (MIP) and microcomputed tomography (μCT), together with the determination of suction, water content, void ratio, and saturation degree. Results showed that the water-retention behavior of bentonite pellet/powder mixture was rather characterized by pellets instead of powder. Due to the stress release, the measured suction after unloading sme was larger than the imposed suction sim. The suction difference Δs between sme and sim depended on both suction and load. Under a given σv, the suction effect was characterized by an increase of Δs when sim decreased from 113 to 4.2 MPa, but by a noticeable decrease of Δs when sim further decreased to zero. This was found to be related to the changes of the slopes of soil-water retention curves (SWRCs): the slope was decreasing with suction increases after 4.2 MPa suction, but was increasing with suction increases before 4.2 MPa suction. As far as the stress effect was concerned, a larger Δs was identified at a higher σv for a given sim. The narrowing difference between Δs and the reduction of mean stress of pellet Δppellet with increasing load was because of the decrease of larger pores due to loading. The total mixture void ratio emixtureT was highly dependent on suction and vertical stress, whereas the total pellet void ratio epelletT was only dependent on suction in the stress range considered
A 3D picture of moist-convection inhibition in hydrogen-rich atmospheres: Implications for K2-18 b
No full textInternational audienceWhile small, Neptune-like planets are among the most abundant exoplanets, our understanding of their atmospheric structure and dynamics remains sparse. In particular, many unknowns remain on the way moist convection works in these atmospheres where condensable species are heavier than the non-condensable background gas. While it has been predicted that moist convection could shutdown above some threshold abundance of these condensable species, this prediction is based on simple linear analysis and relies on some strong assumptions on the saturation of the atmosphere. To investigate this issue, we develop a 3D cloud resolving model for hydrogen-dominated atmospheres with large amounts of condensable species and apply this model to a prototypical temperate Neptune-like planet-K2-18 b. Our model confirms the shutdown of moist convection above a critical abundance of condensable vapor and the onset of a stably stratified layer in the atmosphere of such planets, leading to much hotter deep atmospheres and interiors. Our 3D simulations further provide quantitative estimates of the turbulent mixing in this stable layer, which is a key driver of the cycling of condensables in the atmosphere. This allows us to build a very simple, yet realistic 1D model that captures the most salient features of the structure of Neptune-like atmospheres. Our qualitative findings on the behavior of moist convection in hydrogen atmospheres go beyond temperate planets and should also apply to the regions where iron and silicates condense in the deep interior of hydrogen-dominated planets. Finally, we use our model to investigate the likelihood of a liquid ocean beneath a H 2 dominated atmosphere on K2-18 b. We find that the planet would need to have a very high albedo (A > 0.5-0.6) to sustain a liquid ocean. However, due to the spectral type of the star, the amount of aerosol scattering that would be needed to provide such a high albedo is inconsistent with the latest observational data
A model of growth with living capital
No full textAcknowledging the economic role of knowledge, education, training and health, can preserve and make them thrive without assuming that preferences depend on any of them. Here, living capital is defined as their aggregate.In a planned economy, we find that the optimal sequence of total cap- ital is always monotonic. Depending on the productivity of total capital (defined as the sum of physical and living capital), three different regimes hold: bounded growth; asymptotically balanced unbounded growth or unbalanced unbounded growth.Only at the very early stages of development the economy devotes all its investment effort to increase the stock of physical capital and only physical capital. As the economy develops, it will start using living capital in production. In the first regime, total capital converges to a steady state with a positive stock of total capital, which is larger than the one without living capital. In the second regime, growth becomes unbounded, and consumption grows at a constant rate. Total capital grows at the same rate but only asymptotically. In the third case, living capital is used increasingly at the beginning. Once the economy is sufficiently rich, physical capital starts growing faster than living capital.To close, we consider a market economy with externalities from the living. In this case, if the government levies taxes to finance the accumulation of living capital and implements exactly the optimal sequence of living capital as in the planner’s program, then the equilibrium market prices decentralize exactly the planner’s solution
Exploring the effects of wildfires on stratospheric aerosol composition anddynamics using satellite and ground-based lidars
No full textInternational audienceThe severity of wildfires has remarkably increased over the last years in both Northernand Southern hemispheres and there is an emerging realization of their effect on climate andozone layer. Intense wildfires give rise to extreme thunderstorms termed PyroCb, which caninject significant amounts of smoke into the stratosphere. A number of recent studies havedemonstarted that the effects of strong PyroCb outbreaks on the global stratosphere can rivalthose of moderate volcanic eruptions in terms of magnitude and duration whilst exceedingthem in terms of radiative forcing. Furthermore, the PyroCb injections into the stratospherewere shown to generate persistent synoptic-scale anticyclones (SCV – Smoke-ChargedVortex), lofting confined bubbles of smoke deep into the stratosphere due to solar heating ofcarbonaceous aerosols, which prolongs their atmospheric residence time and radiativeeffects.Here we exploit a synergy of satellite and ground-based lidar observations to characterizethe impact of PyroCb on the stratospheric aerosol composition and dynamics. We useCALIOP observations of aerosol backscatter and depolarization to characterize the opticalproperties of stratospheric smoke aerosols, their evolution and longevity. Additionally, weuse multi-decade aerosol lidar records at the French Observatoire de Haute Provence (43.9N) and Lauder observatory in New Zealand (45.0 S), both located downwind of the mainsources of PyroCb activity. Using the long-term ground-based and satellite lidarobservations of depolarization, we point out the longevity of fine smoke particles in thestratosphere.The multi-wavelength fluorescence lidar observations at the French LILAS site are usedto constrain the optical properties of stratospheric smoke plumes, which provides anaccurate reference for estimating the radiative forcing of persistent smoke plumes in thestratosphere.Finally, the global wind profiling, exclusively provided by Aeolus Doppler lidar, is usedto explore the dynamics of the rotating smoke plumes and related generation of downward-propagating gravity wave
Séparation à la source des excrétats : bases pour des règles professionnelles
No full textInternational audienceCet article aborde la séparation à la source des urines et matières fécales en France dont le déploiement s’intensifie depuis le début des années 2010. Il présente un état des lieux en France et à l’international des modes de gestion des excrétats humains en dehors de la filière « eau ». Après avoir abordé les enjeux associés à l’environnement et à la réglementation de telles pratiques, les principes de fonctionnement et de mise en œuvre sont détaillés en s’appuyant sur 4 exemples de filières. Enfin, sont abordées, au regard de la montée en puissance de ce sujet, les questions à se poser pour déployer ces installations et les perspectives associées
Performance Comparison of Augmented Reality Versus Ultrasound Guidance for Puncture: A Phantom Study
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Menstrual Stigma, Hygiene, and Human Capital: Experimental Evidence from Madagascar
No full textThis paper presents results from an RCT in 140 schools in Madagascar that targets both hygiene practices and menstrual stigma. First, we show that a bundle of interventions (sanitation infrastructure, menstrual products, and teacher sensitization) leads to substantial (0.15 SD) improvements in learning tests and school marks, without affecting attendance or health. These learning benefits appear to be driven by reduced stress and an improved psychosocial environment in treatment schools, where girls’ heart rate at endline is lower (-0.12 SD), severe bullying is less common (-0.08 SD), and a measure of network integration is higher (+0.24 SD). Second, we evaluate the additional effect of nominating and coaching “young girl leaders” - school girls willing to speak out against menstrual stigma - to spread positive messages about hygiene and menstruation. The combined program generates substantial improvements in hygiene knowledge and behavior (0.33-0.56 SD) and in menstrual stigma (0.74 SD), and the Young Girl Leader component significantly increases the impact on all of these dimensions
Fluorescence spectroscopy for tracking microbiological contamination in urban waterbodies
No full textInternational audienceDissolved organic matter (DOM) plays a crucial role in freshwater ecosystem function. Monitoring of DOM in aquatic environments can be achieved by using fluorescence spectroscopy. Particularly, DOM fluorescence can constitute a signature of microbiological contamination with a potential for high frequency monitoring. However, limited data are available regarding urban waterbodies. This study considers fluorescence data from field campaigns conducted in the Paris metropolitan region: two watercourses (La Villette basin and the river Marne), two stormwater network outlets (SO), and a wastewater treatment plant effluent (WWTP-O). The objectives of the study were to characterize the major fluorescence components in the studied sites, to investigate the impact of local rainfall in such components and to identify a potential fluorescence signature of local microbiological contamination. The components of a PARAFAC model (C1-C7), corresponding to a couple of excitation (ex) and emission (em) wavelengths, and the fluorescence indices HIX and BIX were used for DOM characterization. In parallel, fecal indicator bacteria (FIB) were measured in selected samples. The PARAFAC protein-like components, C6 (ex/em of 280/352 nm) and C7 (ex/em of 305/340 nm), were identified as markers of microbial contamination in the studied sites. In the La Villette basin, where samplings covered a period of more than 2 years, which also included similar numbers of wet and dry weather samples, the protein-like components were significantly higher in wet weather in comparison to dry weather. A positive relationship was obtained between C6 and FIB. In urban rivers, the high frequency monitoring of C6 levels would support the fecal contamination detection in rivers. In addition, it could help targeting specific field campaigns to collect comprehensive dataset of microbiological contamination episodes
Stronger Oceanic CO<sub>2</sub> Sink in Eddy-Resolving Simulations of Global Warming
No full textInternational audienceUnderstanding the ocean's capacity to mitigate or amplify human-induced climate change is essential for refining future climate projections, particularly for estimating the remaining carbon budget (Canadell et al., 2021). To date, the ocean absorbs ∼25% of CO2 emissions caused by human activities (Friedlingstein et al., 2022). The ocean's capacity to sequester anthropogenic CO2 makes it a key player in determining the rate at which CO2 accumulates in the atmosphere. Thus an important question is how this oceanic CO2 sink will evolve under continuing CO2 emissions and global warming, because it will influence the pace of climate change. The strength of the oceanic CO2 sink is set by the balance between two mechanisms. The uptake of anthropogenic CO2 by the ocean is primarily a chemical response to the rise in atmospheric CO 2 that forces a growing disequilibrium of the partial pressure of CO2 (pCO2) at the air-sea interface. The carbon-concentration feedback parameter is a metric commonly used to measure how much anthropogenic CO2 is absorbed by the ocean for each additional unit of CO2 (expressed in ppm) added to the atmosphere, assuming the ocean dynamical and thermodynamical state remains unchanged