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Bilan du Groupe de Travail 8 les technologies pour l’apprentissage, l’enseignement et la formation
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The Galaxy Activity, Torus, and Outflow Survey (GATOS). VII. The 20–214 μm Imaging Atlas of Active Galactic Nuclei Using SOFIA
No full textInternational audienceWe present a 19.7–214 μ m imaging atlas of local (4–181 Mpc; median 43 Mpc) active galactic nuclei (AGN) observed with FORCAST and HAWC+ on board the SOFIA telescope with angular resolutions ~3 ″ –20 ″ . This atlas comprises 22 Seyferts (17 Type 2 and five Type 1) with a total of 69 images, 41 of which have not been previously published. The AGN span a range of luminosities of log 10 ( L bol [ erg s - 1 ] ) = [ 42 , 46 ] with a median of log 10 ( L bol [ erg s − 1 ] ) = 44.1 ± 1.0 . We provide the total fluxes of our sample using aperture photometry for point-source objects and a 2D Gaussian fitting for objects with extended host galaxy emission, which was used to estimate the unresolved nuclear component. Most galaxies in our sample are pointlike sources; however, four sources (Centaurus A, Circinus, NGC 1068, and NGC 4388) show extended emission in all wavelengths. The 30–40 μ m extended emission in NGC 4388 is coincident with the narrow-line region at PA ~ 50°, while the dusty extension at longer wavelengths arises from the host galaxy at PA ~ 90°. Our new observations allow us to construct the best-sampled parsec-scales (spectral energy distributions, SEDs) available between 30 and 500 μ m for a sample of nearby AGN. We estimate that the average peak wavelength of the nuclear SEDs is ~40 μ m in νF ν , which we associate with an unresolved extended dusty region heated by the AGN
Incorporation d'un élastomère dans des bicouches de poly(3-hexylthiophène) : vers un film polymère conducteur flexible
No full textInternational audienceAbstract Flexible, wconductive polymer films are crucial for next‐generation wearable electronics, soft robotics and biomedical devices. Traditional conducting polymers like poly(3‐hexylthiophene) (P3HT) are rigid due to strong π–π interactions. We investigated mixtures of polydimethylsiloxane (PDMS), a highly flexible elastomer, and P3HT bilayers to understand their interaction and characterize the resulting nanoscale organization and electronic properties. Composite P3HT:PDMS films were fabricated at the air–water interface, allowing precise control over nanoscale morphology. Characterization revealed complete phase separation with crystalline P3HT nanofibers in a PDMS matrix. Sequential doping with 2,3,5,6‐tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F 4 TCNQ) led to a 4%–5% contraction in the π–π stacking distance, indicating polaron formation while maintaining phase separation. Electronic conductivity measurements revealed a percolation threshold at 30% PDMS content. Films with 10% PDMS achieved conductivities around 0.1 S cm –1 , comparable to pure P3HT. Multilayer films (five layers) reached conductivities up to 1.5 S cm –1 , showing minimal adverse impact on charge transport. © 2025 Society of Chemical Industry
Evidence of haze control of Pluto’s atmospheric heat balance from JWST/MIRI thermal light curves
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Insights from measured versus BSR-derived heat flow in an active gas seeping area of the Amazon deep-sea fan
No full textInternational audienceThe Amazon deep-sea fan is one of the largest sedimentary deposits on passive margins. Its rapid growth in response to the supply of organic-rich sediments from the Amazon River has been accompanied by both fan-wide giant landslides and gravitational collapse on shale detachments. The upper slope compressional belt contains a gas hydrate system indicated by bottom simulating reflection (BSR) patches aligned with the crests of thrust-fold anticlines, which in places rise towards seafloor fluid vents. The 2023 AMARYLLIS-AMAGAS I campaign and the ANR MEGA project aim to study the link between the gas hydrate system, seafloor fluid venting and landslide triggering. Here we present a comparison between new seafloor heat flow measurements and BSR-derived heat flow, along two transects crossingdifferent fluid venting structures (seeps, pockmarks and mud volcanoes) at the crest of an anticline. Measured and BSR-derived values concord that conductive heat flow in the Amazon upper slope is low (32-36 mW/m2), likely due to sediment blanketing. Above the anticline measured heat flow increases regionally to 41-55 mW/m2. Near active venting structures measured surface heat flow increases to values up to 115-185 mW/m2. BSR-derived heat flow also increases but to a lesser extent. The magnitude and extent of the heat flow anomaly are both fully compatible with a model where fluids bring heat by advection from deeper sedimentary levels to the seafloor along near-vertical conduits. The source depth of the fluid expulsion is likely not very deep (100-200m) and corresponds to the depth of the base of the gas hydrate stability zone (GHSZ) and where gas hydrates may be locally dissociating beneath venting structures. These data and modeling results suggest that deep fluids migrating upwards in the thrust-fold anticlines along faults and/or pinch-out layers are blocked by gas hydrates forming in the stability zone. These warmer fluids will dissociate the hydrates near the base of the GHSZ, elevating the base of the stability zone and locally breaching it towards the seafloor. Normal faults observed above anticline crests indicate extensional stresses that may favor fluid migration to seafloor, consistent with the distribution of fluid venting structures in the study area
La "grande accélération" à l'aune de la demande de transport internationale
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Appréhender l'inconnu et s'y familiariser : processus expérientiel de l'apprentissage de la langue arabe
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Beliefs on proof in mathematics: a survey of future elementary school teachers in Switzerland
No full textV1 Soumise : INDRUM 2026This paper analyzes the conceptions of proof among first-year bachelor's students, future primary school teachers, in the context of current thinking in proof research. Using a questionnaire tailored to this audience, we study the functions of proof that they recognize, as well as their criteria for evaluating the rigor and validity of different types of proof. The results show a clear gap between their ability to identify intellectual, deductive proof as rigorous and the empirical or perceptual approaches relevant to pragmatic proof that they spontaneously mobilize. Explanatory and verification functions dominate, while more social dimensions appear only marginally. These results highlight the need to reinforce, in initial training, the active and diversified appropriation of the activity of proof
The Onset of Summer Drought on the Iberian Peninsula Following Pliocene Global Cooling
No full textInternational audienceThe highly biodiverse Iberian Peninsula has winter-dominated precipitation and summer drought. The onset of this modern climate regime, termed a Mediterranean-Type Climate, began during the Late Pliocene–Early Pleistocene, concurrent with global cooling. To advance our understanding of regional hydroclimate changes in relation to past global changes, we present a stable oxygen isotope record measured on paleosol carbonates (δ18Oc) from Teruel, Spain spanning 4.1–2.4 Ma, when the regional ecosystems shifted from subtropical requiring high humidity to dominantly drought-tolerant. The δ18Oc values show a negative excursion during Marine Isotope Stage M2 (∼3.3 Ma) and a subsequent decrease during the onset and intensification of the Northern Hemisphere Glaciation (iNHG: ∼2.73 Ma). While the δ18Oc decrease during global cooling could have resulted from less high-δ18O summer rainfall and/or intensified low-δ18O winter rainfall, comparison with previously published proxy records point toward drying in the Mediterranean Basin during the Late Pliocene. We therefore propose that global cooling at this time resulted in lower Atlantic and Mediterranean sea surface temperatures during the iNHG which decreased moisture availability to the Mediterranean Basin, and together with enhanced and equatorward shifted Hadley circulation, reduced summer rainfall in the Mediterranean Basin when compared to the conditions of the Early Pliocene
Enseigner la géographie et l'anglais en classe de DNL : étude de cas autour d'un exercice de production graphique au lycée
No full textInternational audienceEn France, les recherches sur la didactique de la DNL (Disciplines Non Linguistiques) semblent peu développées (Carlo et Verdelhan-Bourgade, 2007), d'autant plus celles portant sur la didactique de la DNL en géographie (Denmat, 2024). Pourtant, les enjeux didactiques sont nombreux, que ce soit sur les spécificités de la langue de spécialité, sur les différences entre géographie francophone et anglophone ou encore sur la formation des enseignants de DNL (Manoïlov et Leroux, 2024).Dans le cadre d'une recherche collaborative associant enseignant.es d'histoire-géographie et chercheurs.ses, nous avons mené une expérimentation dans 3 classes de DNL de lycée portant sur la réalisation de production graphique sur la métropolisation. Le procédé de l'information fragmentée a permis d'amener les élèves à collaborer et à interagir en anglais, par binôme, pour réaliser leur schéma. L'objectif de cette expérimentation était d'étudier les enjeux didactiques disciplinaires et langagiers à l'œuvre dans un exercice typique de la classe de géographie. Ces activités ont été filmées et les productions graphiques des élèves ont été collectées. C'est sur ce matériau que se fonde cette communication. En mêlant point de vue des enseignant.es et point de vue des chercheur.ses, nous proposons de revenir sur les verrous didactiques identifiés et les moyens mis en place pour renforcer la complémentarité des langages graphiques et linguistiques et visant à renforcer la compréhension du concept de métropolisation chez les lycéens.Il s'agira ainsi de revenir sur les « malentendus » (Naudet, 2024) entre enseignants et élèves qui ont été identifiés concernant les enjeux de la tâche finale. En effet, les productions graphiques réalisées se sont par exemple révélées très descriptives et ne traduisant pas les dynamiques métropolitaines attendues. Les films ont permis de mettre en perspective ces résultats en montrant que les élèves ont eu tendance à concentrer leurs efforts sur les enjeux lexicaux liés à l'activité. Cependant, les échanges entre les élèves sur les choix de sémiologie graphique ou sur l'organisation de leur légende montrent bien que la tâche menée permet aux élèves de penser leur schéma, même dans le cadre de la DNL. La communication proposera également des pistes de remédiation, testées dans le cadre de l'expérimentation