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Imaging Bajocian coral ridges in the Paris Basin and deciphering their origin
No full textInternational audienceEnigmatic N120° ridges have been identified from 3D seismic reflection imaging of the Bajocian limestones of the eastern Paris Basin. These features may impact flows within the active Middle Jurassic aquifer beneath the Callovian–Oxfordian claystones and marls that host the Underground Research Laboratory (URL) where the Andra (French National Agency for Radioactive Waste Management) is studying the feasibility of a deep repository for radioactive waste. Worldwide, there are numerous other examples where carbonate buildups form ridges in 3D, which are more or less interconnected, laterally amalgamated, or bifurcating, with no clear reason for these geometric features.It is consequently of paramount importance to understand the nature and origin of these ridges, and an integrated study combining (1) well logs, (2) new 3D seismic acquisitions, (3) classical field sedimentology and stratigraphy, (4) near-surface geophysics including Ground Penetrating Radar (GPR), electrical resistivity tomography (ERT) and frequency-domain electromagnetics (FDEM), and (5) seismic refraction has been developed to investigate them.Facies analysis and a regional sequence stratigraphy interpretation, integrating near-surface geophysical imaging, performed on time-equivalent outcrop sections demonstrate that elongated mounds of hermatypic scleractinian corals developed during the early Bajocian (Humphriesianum chronozone) in shallow, warm oligotrophic seawater. These buildups nucleated as patches on hardground atop giant subaqueous dunes composed of peloidal and bioclastic grainstones, dipping mostly N30° with N120°-oriented crests. Some of the coral reefs form buildups up to 15 m high and several hundred meters wide. They are elongated in the main N120° direction of the underlying dunes, although the dispersion of measurements illustrates the complexity of the interfingered structures observed in 3D seismic images. The coral buildups are progressively onlapped and draped by oncoid-rich alternating marl-limestones that may result from a shift from oligotrophic to mesotrophic conditions probably brought about by a rise in relative sea level. Near-surface geophysics provide insightful supporting evidence to supplement the field work, particularly by imaging the roots of several coral reefs, their internal structures, and the infill of the inter-reefal troughs.This work demonstrates the critical importance of outcrop analogue studies for resolving subsurface problems and also shows how near-surface geophysical methods can usefully supplement direct classical field geology investigations. This new characterization suggests that coral reefs forming ridges, structures that have often remained enigmatic, could develop by directly settling at the top of early cemented giant oo-bioclastic dunes. Submarine early diagenesis generates hardgrounds that constitute stable substrates for nucleation and growth of coral reefs, especially when they cap prominent submarine reliefs
Response to the letter by Xiaoming Zou on “Earthworms as mutualists rather than predators of soil microorganisms”
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Aspiration pneumonia guidelines – Société de Pathologie Infectieuse de Langue Française 2025
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Objectiver le sentiment de manque de soutien des enseignants en proie à des difficultés professionnelles
No full textInternational audienceLes enquêtes internationales montrent des enseignants français majoritairement stressés par le travail (OCDE, 2020). Le modèle de Karasek analyse le stress par la relation entre charge de travail, degré d’autonomie et soutien social. Nous proposons d’étudier cette dernière dimension pour éclairer les difficultés psychosociales des enseignants, notamment associées à un climat scolaire dégradé (Janot-Bergugnat & Rascle, 2008). Les enseignants exposés aux désordres scolaires expriment un sentiment de manque de soutien (Debarbieux & Moignard, 2023), en particulier de leur hiérarchie (Radé, 2018).Ce sentiment est traditionnellement mesuré par l’autodéclaration. Nous proposons une autre approche grâce à l’étude de signalements au registre santé et sécurité au travail, qui permet aux enseignants français de signaler toute situation de danger. Nous formulons l’hypothèse qu’à travers ces fiches, ils peuvent trouver un espace d’expression de leurs difficultés professionnelles et que la manière dont elles sont prises en compte alimente le sentiment de pouvoir ou non s’appuyer sur un soutien institutionnel. Ce terrain d’enquête nous permet donc, à travers une étude lexicométrique, d’objectiver le concept de soutien, en dépassant le simple ressenti.Nos résultats montrent que les inspecteurs de l'éducation nationale, supérieurs hiérarchiques directs dans le premier degré, apportent un soutien émotionnel explicite aux enseignants confrontés à des difficultés professionnelles liées aux relations dégradées avec les usagers (élèves, parents). Fréquemment, les équipes de circonscription qui entourent les inspecteurs apportent un soutien informationnel sous la forme de conseils. Par contre, le soutien instrumental est limité, en particulier quand les relations sont dégradées avec les parents. Notre étude fait le lien entre le sentiment d’abandon exprimé par les enseignants et le manque de solutions internes proposées par la hiérarchie
Is 3D, a more accurate quantitative method than 2D, crucial for analyzing disparity patterns in extinct marine arthropods (Trilobita)?
No full textInternational audiencePhacopid trilobites are well documented during the Paleozoic. Nevertheless, while 2D quantitative analyses have advanced our understanding of the morphological relationships among trilobites, the quantification of their morphological traits in 3D remains rarely documented. Based on two sets of morphological data (head and tail), 2D versus 3D shape quantification approaches were used to explore shape allometries as well as to explore how the shape variations can be explained by the phylogenetic relationships among phacopid trilobite species for the first time. We demonstrate that (1) there are similar patterns of morphological variability across taxa in 3D and 2D; (2) there are rather congruent results between 3D and 2D to discriminate taxa; (3) 2D and 3D landmarks capture different levels of detail, and the third dimension in 3D is very important for making taxonomic distinctions at the genus level; (4) there is congruity between 2D and 3D datasets for allometric patterns with results showing similar allometric slopes among species exhibiting a glabellar length decrease during growth leading to wider cephala; (5) the phylomorphospaces show tree branches that do not intersect, suggesting possible phylogenetic constraints on morphospace occupation for each species and supporting the idea that the Austerops and Morocops groups are sister clades that experienced different modes of morphological evolution; and (6) the morphological descriptors in morphometric analyses in 2D and 3D throughout phacopid evolution are effective
DIJON : Des bouteilles de vin plongées dans le réservoir Darcy pour une expérience scientifique [communiqué]
No full textCompte-rendu d'interview utilisé dans article.National audienceDes vignerons du Dijonnais et des chercheurs s'associent à la municipalité pour lancer une expérimentation scientifique de 10 ans portant sur la conservation du vin en immersion dans l'eau
Climate changes at the Jurassic/Cretaceous transition vs. supra-regional oceanographic processes: Insights from the Vocontian Basin (Clue de Taulanne section, SE France)
No full textInternational audienceHerein are presented the results of a detailed stratigraphic calibration and palaeoenvironmental studies performed in the upper Tithonian–lowermost Valanginian deposits of the Vocontian Basin (SE France), with special attention being paid to the Clue de Taulanne section. Integration of calpionellid biostratigraphy, magnetostratigraphy and δ13C stratigraphy, supplemented with regional correlations, enables precise dating of the latest Jurassic–earliest Cretaceous climate and oceanographic perturbations. These are recognized based on sedimentologic (microfacies analyses, clay mineralogy) and geochemical (elemental geochemistry, TOC) investigations. This research confirms that the latest Tithonian–early Berriasian (Tintinnopsella remanei–mid Calpionella elliptica subzones) was marked by a phase of dry climate and elevated burial of micronutrients. Furthermore, the uppermost Tithonian (Remanei/Massutiniana subzonal transition) documents an important palaeoecologic turnover, that is the disappearance of Saccocoma and a switch from radiolarian- to calpionellid-dominated microfacies. The subsequent shift towards humid palaeoclimate conditions at the early/late Berriasian transition was relatively rapid (~ 0.5 Ma), as evidenced by a significant increase in kaolinite proportion within the mid-Elliptica Subzone (mid M17r magnetozone; latest early Berriasian). Importantly, this major climate change was associated with lowered burial of nutrient-type elements, relative to lithogenic fraction. Collected data not only evidence the relation between the latest Jurassic–earliest Cretaceous climate and oceanographic processes, but also document biotic response to these perturbations. The regional significance of the above findings is evidenced by correlations between different sedimentary zones of the Vocontian Basin (Clue de Taulanne, Berrias, Montclus and Tré Maroua sections), while supra-regional context is provided by comparison with other Alpine Atlantic successions: Transdanubian Range and the Slovenian Basin
Impact of salting practices on sodium distribution in carrots assessed by quantitative MRI
No full textInternational audienceCurrently, sodium consumption is significantly higher than the 5 g per day recommended by health organizations. This paper aimed to compare salt distribution in food according to domestic salting practices. For this study, carrots boiled in water were used as a food model. Two practices were compared. On the one hand, sprinkling salt on the food after cooking, and on the other one, adding salt during cooking (i.e. in the cooking water). Two salts were compared: fine sea salt and fleur de sel, the latter having larger crystals. Sodium distribution, which is assumed to influence saltiness perception, can be assessed by quantitative MRI (qMRI). Thanks to a newly developed methodology, quantitative sodium maps were successfully obtained for the two salting practices. It was also possible to monitor the evolution of sodium distribution in different parts of the cooked carrots. Results show that a more heterogeneous distribution of sodium is obtained when salting is performed after cooking using fleur de sel compared to when salting is performed during cooking. The expected results allow us to highlight practices in terms of table salt use that can easily be adopted by consumers to increase the sensory availability of discretionary salt therefore lowering salt intake
Les conséquences institutionnelles des modes de financement de la reconstruction économique post-crise 2024 en Nouvelle-Calédonie : soutien financier de l'Etat et investissements directs étrangers chinois face aux défis d'autodétermination et d'indivisibilité de la République
No full textInternational audienceRésumé :Les émeutes du 13 mai 2024 ont plongé la Nouvelle-Calédonie dans une crise politique et économique majeure, mettant en péril sa stabilité institutionnelle. Malgré trois référendums en faveur du maintien dans la République française, le territoire reste profondément divisé entre aspirations indépendantistes et attachement à la Nation. Dans ce contexte, la reconstruction économique, rendue urgente par des pertes estimées à un tiers du PIB, repose sur des financements stratégiques. Cet article examine l’impact différencié des financements alloués par la France et la Chine à la relance économique, dans une perspective mêlant sociologie financière et géopolitique. Si l’aide française, ancrée dans la solidarité nationale, vise à consolider l’unité de la République, l’engagement économique de la Chine apparaît comme un levier d’influence soutenant les aspirations indépendantistes. À travers cette étude, il s’agit de comprendre comment les instruments financiers deviennent des outils d’action politique, capables de remodeler les relations intergouvernementales et de redéfinir la place de la Nouvelle-Calédonie dans les équilibres régionaux du Pacifique.Abstract:The riots of 13 May 2024 plunged New Caledonia into a major political and economic crisis, jeopardising its institutional stability. Despite three referendums in favour of remaining part of the French Republic, the territory remains deeply divided between independence aspirations and attachment to the nation. In this context, and with losses estimated at a third of GPD, the economic reconstruction becomes urgent and relies on strategic financing. This article examines the specific impact of the funding allocated to economic recovery by France and China from the viewpoint of financial sociology and geopolitics combined. While the aim of French aid is rooted in national solidarity and aims at consolidating the unity of the Republic, China’s economic commitment appears to be a levering influence supporting independence aspirations. The aim of this study is to understand how financial instruments become tools for political action, are capable of reshaping intergovernmental relations and of redefining New Caledonia’s place in the Pacific regional balance.Les émeutes du 13 mai 2024 ont plongé la Nouvelle-Calédonie dans une crise politique et économique majeure, mettant en péril sa stabilité institutionnelle. Malgré trois référendums en faveur du maintien dans la République française, le territoire reste profondément divisé entre aspirations indépendantistes et attachement à la Nation. Dans ce contexte, la reconstruction économique, rendue urgente par des pertes estimées à un tiers du PIB, repose sur des financements stratégiques. Cet article examine l’impact différencié des financements alloués par la France et la Chine à la relance économique, dans une perspective mêlant sociologie financière et géopolitique. Si l’aide française, ancrée dans la solidarité nationale, vise à consolider l’unité de la République, l’engagement économique de la Chine apparaît comme un levier d’influence soutenant les aspirations indépendantistes. À travers cette étude, il s’agit de comprendre comment les instruments financiers deviennent des outils d’action politique, capables de remodeler les relations intergouvernementales et de redéfinir la place de la Nouvelle-Calédonie dans les équilibres régionaux du Pacifique
Degrowth + marketing = demarketing? Rethinking demarketing as an effective tool for sufficiency
No full textInternational audienceThis paper explores the intersection of demarketing and degrowth, proposing a new framework that aligns demarketing practices with sufficiency principles. While traditional demarketing approaches often prioritize profit-driven, instrumental goals, they remain incompatible with the transformative objectives of degrowth, such as addressing systemic overconsumption and fostering equitable resource distribution. Through a critical review of the demarketing literature, we identify key gaps, including the neglect of environmental limits, equity, and consumer well-being. We argue that sufficiency—a principle emphasizing “enoughness” and ecological sustainability—provides a compelling lens for redefining demarketing. By integrating sufficiency into demarketing, we outline pathways to transition from growth-oriented practices to degrowth-consistent strategies, offering theoretical and practical insights into reshaping marketing. Our contribution lies in advancing a degrowth-consistent definition of demarketing that challenges conventional marketing paradigms, paving the way for systemic change in research and practice