Une analyse de lutilisation doutils de création numérique en expression graphique chez de jeunes élèves

Le graphisme des enfants de trois à douze ans a constitué lobjet de nombreuses recherches, mais sans jamais sinterroger sur linfluence possible de lergonomie de loutil de production des dessins sur la production elle-même. Lutilisation doutils numériques de création modifierait-elle, et dans quel sens, les performances des enfants par rapport à lusage de techniques traditionnelles ? En comparant, daprès un système de cotation validé en psychométrie, les dessins dun bonhomme réalisés en utilisant une tablette graphique, puis un matériel traditionnel, nous montrons que des enfants sont aussi performants avec un outil numérique quavec un outil analogique. Plus qualitativement, utiliser une tablette graphique napparaît pas comme un frein à une représentation correcte ainsi quà la créativité mais semble au contraire les faciliter

Trade-off between predictive performance and FDR control for high-dimensional Gaussian model selection

In the context of the high-dimensional Gaussian linear regression for ordered variables, we study the variable selection procedure via the minimization of the penalized least-squares criterion. We focus on model selection where the penalty function depends on an unknown multiplicative constant commonly calibrated for prediction. We propose a new proper calibration of this hyperparameter to simultaneously control predictive risk and false discovery rate. We obtain non-asymptotic theoretical bounds on the False Discovery Rate with respect to the hyperparameter and we provide an algorithm to calibrate it. It is based on completely observable quantities in view of applications. Our algorithm is validated by an extensive simulation study and is compared with some existing variable selection procedures. Finally, we propose a study to generalize our approach in complete variable selection.Comment: 39 pages, 10 figures, 1 algorithm, 3 table

Efficacité de la formation par Apprentissages par Problèmes (APP) pour l'acquisition des compétences scientifiques et techniques en Cursus Master Ingénierie

International audienceThe aim of this paper is to introduce problem based learning (PBL) as one of the solutions to the lack of satisfaction as regards the traditional teaching (explicit teaching) of disciplinary skills expected from an engineer. The experiment is led in a bachelor's degree in Sciences for the Engineer, within a Master's degree Engineering Program (CMI) on the course entitled Study of mechanical systems. The method held to estimate the efficiency of PBL is based on diverse criteria of efficiency such as learning gain, transfer of knowledge. The partial results obtained show that PBL is effective on the acquisition of disciplinary skills.Cet article a pour objet l'apprentissage par problèmes (APP) qui est une des solutions possible, à partir du constat de non satisfaction de l'enseignement traditionnel (explicite) vis à vis des compétences disciplinaires attendues d'un ingénieur. L'expérimentation est menée en licence sciences pour l'ingénieur dans un Cursus Master Ingénierie (CMI) sur l'UE étude des systèmes mécaniques. La méthode retenue pour évaluer l'efficacité du dispositif en APP est fondée sur divers critères de l'efficacité (exemples : gain d'apprentissage, transfert des connaissances,…). Les résultats partiels obtenus montrent que le dispositif en APP est efficace sur l'acquisition des compétences disciplinaires

Les vésicules extracellulaires comme nouveaux biomarqueurs d’exposition: Les vésicules extracellulaires comme nouveaux biomarqueurs de toxicité des polluants environnementaux

National audienceLes vésicules extracellulaires sont de petites vésicules membranaires qui peuvent être libérées par tous types cellulaires et se retrouvent, pour une grande majorité, dans les liquides biologiques. Le but du projet "VESITOX" est de caractériser les vésicules extracellulaires produites après exposition aux PM2,5 ou au tabac dans le but d’identifier des biomarqueurs d’exposition et d’effet de ces polluants environnementaux

Circularity in Mineral and Renewable Energy Value Chains: Overview of Technology, Policy, and Finance Aspects

The mineral-intensive global energy transition and the increasing material needs of a growing population will exacerbate mining’s footprint on the planet, under current linear economy conditions. Responsible primary production of minerals and metals needs to be combined with circular economy approaches. CCSI’s report, Circularity in Mineral and Renewable Energy Value Chains: Overview of Technology, Policy, and Finance Aspects, examines existing conditions as well as reforms needed to enable global circularity in the mineral value chains of solar photovoltaic (PV) panels and wind turbines, zeroing in on four key materials: aluminum, copper products, silicon, and steel. The project was supported by ICMM and the Enel Foundation

The proliferating cell nuclear antigen regulates retinoic acid receptor transcriptional activity through direct protein–protein interaction

Retinoic acid receptors (RARs) interact, in a ligand-dependent fashion, with many coregulators that participate in a wide spectrum of biological responses, ranging from embryonic development to cellular growth control. The transactivating function of these ligand-inducible transcription factors reside mainly, but not exclusively, in their ligand-binding domain (AF2), which recruits or dismiss coregulators in a ligand-dependent fashion. However, little is known about AF2-independent function(s) of RARs. We have isolated the proliferating cell nuclear antigen (PCNA) as a repressor of RAR transcriptional activity, able to interact with an AF2-crippled RAR. The N-terminus of PCNA interacts directly with the DNA-binding domain of RAR, and PCNA is recruited to a retinoid-regulated promoter in intact cells. This interaction affects the transcriptional response to retinoic acid in a promoter-specific manner, conferring an unanticipated role to PCNA in transcriptional regulation. Our findings also suggest a role for RAR as a factor coordinating DNA transcription and repair

Tri-Frequency Synthetic Aperture Radar for the Measurements of Snow Water Equivalent

A new airborne synthetic aperture radar (SAR) system was recently developed for the estimation of snow water equivalent (SWE). The radar is part of the SWESARR (Snow Water Equivalent Synthetic Aperture Radar and Radiometer) instrument, an active passive microwave system specifically designed for the accurate estimation of SWE. The dual polarization (VV, VH) radar operates at three frequency bands (9.65 GHz, 13.6 GHz, and 17.25 GHz), with bandwidths of up to 200 MHz. The radar flew its first flight campaign in November 2019, along with SWESARRs - already operational radiometer. The radar collected comprehensive data sets over various terrains that show a successful system performance. The inst slated to participate in future SnowEx campaigns

Tri-Frequency Synthetic Aperture Radar for the Measurements of Snow Water Equivalent

SWESARR (Snow Water Equivalent Synthetic Aperture Radar and Radiometer) is an airborne instrument developed at the NASA Goddard Space Flight Center for the retrieval of Snow Water Equivalent. SWESARR was specifically designed to measure co-located active and passive signals using a high resolution and multi-frequency Synthetic Aperture Radar (SAR) and a multifrequency radiometer. SWESARRs Synthetic Aperture Radar (SAR) system is made up of three independent radar units that operate in the X, Ku-Low, and Ku-High bands with bandwidths up to 200 MHz, and acquires data in two polarizations (dual-polarization radar). The difference in sensitivity of the backscatter signals to snow microstructure, in conjunctions with radiometer measurements, permits an accurate estimation of the snow water equivalent (SWE)

The Case for a Climate-Smart Update of the Africa Mining Vision

The 2009 Africa Mining Vision (AMV) provides guidance for the industrialization of African countries by leveraging their mining sector. However, the global context has changed since its adoption. As a result, it does not include guidance on how governments should embrace the climate change agenda as an opportunity for better and further industrialization, deeper linkages, and sustainable development. There are many ways to look at the implications of international climate change policy for Africa, including through the increased extraction of minerals needed in clean energy application and the greening of mines. The localization of global value chains – induced by a rising carbon cost and by the desire to build resilience in supply chains in light of increased pandemic risks – provides another set of opportunities. Seizing this momentum will require policy guidance to ensure that the relocation of industries in global value chains occurs upstream (closer to mineral sources) rather than downstream (closer to final consumers). An open acknowledgment of the impact of climate change on the shifting global value chains for critical minerals and the need to broaden the governance framework to include the emerging role of sustainability and ESG requirements should form the foundation for a revised and revitalized AMV. Read our policy brief elaborating these suggested foundations as well as research directions for a climate-smart update of the AMV

Transferred Emissions Are Still Emissions: Why Fossil Fuel Asset Sales Need Enhanced Transparency and Carbon Accounting

In a widely reported trend, the “Oil Supermajors” — BP, Chevron, ConocoPhillips, Eni, ExxonMobil, Shell, and TotalEnergies — are selling off many upstream fossil fuel assets. Selling these assets to entities that will continue producing and selling the fossil fuel resources does not necessarily reduce greenhouse gas emissions, but the supermajors have used these asset sales to support claims that they are making progress toward reaching net-zero greenhouse gas emissions. Emissions reporting frameworks allow companies to conflate the apparent emissions reductions from asset sales with direct reductions from efficiency improvements and asset retirements. In doing so, they hinder the ability of investors and the public to push for actual emissions reductions. In addition, the companies that buy these assets are sometimes governed by less rigorous reporting requirements and subject to less public scrutiny than the supermajors, further removing the assets sold and their emissions from public scrutiny. It is crucial to track and monitor the emissions attributable to fossil fuel assets even after they are sold. This report assesses the regulatory landscape governing the corporate disclosure of fossil fuel asset sales, outlines the scale of fossil fuel asset sales by the supermajors, and proposes regulatory reforms to enhance transparency around fossil fuel asset sales by oil and gas companies