Portail "HAL-Francophonie Afrique et Océan Indien"
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Une histoire des sports olympiques d'hiver
No full textInternational audienceConsidérés aujourd’hui comme l’un des évènements sportifs internationaux majeurs, les Jeux olympiques d’hiver ont connu une émergence contrastée et un développement contesté, depuis la question de l’existence même des JO d’hiver, à laquelle les pays nordiques s’opposèrent longtemps, jusqu’à celle de la présence de nouveaux sports, qui frappe régulièrement à la porte des Jeux. Dépendants des contraintes spatiales pour glisser ou patiner, les Jeux olympiques d’hiver vont être confrontés à une série de défis qui vont fréquemment remettre en question leur existence comme leur sens. L’internationalisation réduite des pays concernés, la faiblesse du nombre de pratiquants comme le périmètre réduit de ces sports, le changement climatique ou la concurrence de nouvelles activités sont quelques-uns des défis qui se sont présentés aux JO d’hiver, amenant à des transformations significatives. Réunissant les meilleurs spécialistes internationaux de chaque sport, l’ouvrage témoigne d'une volonté d’offrir au lecteur français un panorama, discipline par discipline, qui dépasse la simple compétition pour questionner le contexte politique, économique, culturel et social. Il conduit à étudier le processus d’ olympisation des sports concernés et les conséquences quant à leurs formats, leurs modalités de pratiques, comme leur reconnaissance. Cet ouvrage propose en définitive un siècle d'histoire des sports olympiques d’hiver au prisme de l’histoire du monde, à travers 15 articles sur chacune des disciplines au programme de Milan-Cortina 2026
ONELO, une intelligence documentaire pour réaliser du publipostage en Administration
No full textInternational audienceIn administration, many different documents are produced. These include memos to inform employees of important changes, travel orders for upcoming trips, and certificates of attendance issued following participation in an event. Ensuring good service quality often means producing compliant documents quickly and with a minimum of errors. Few administrations still allow themselves to operate manually. Those that have moved towards digitisation still fall short in terms of outdated practices. In this configuration, separate pieces of information are still entered by hand, with the risk of inappropriate changes to the final formatting of the documents produced. In the Myènè language, ONège ELèle Ovono (ONELO) means Agile, Easy, Ingenious. Our ONELO tool is a unified strategy for intelligent mass mailing of administrative documents. For example, if we want to produce 100 certificates of participation in an event in a matter of seconds, a first MS Excel file will contain the contact details of the 100 participants (surnames, first names, email addresses, ...), a second MS Excel file will extract only the relevant information (surnames, first names) from the previous file, and a third MS PowerPoint file will group together the graphic charter (logo, signatures, event name, etc.) in image format. The data generated above will be formatted in a fourth MS Word file, which can be printed (in PDF or paper format) to produce a separate certificate for each of the 100 participants. ONELO, our document intelligence system, has several advantages. We can produce a large number of documents in a short time, with few errors and high resolution. ONELO documents can be shared internally. Several tools are similar to ONELO but require a permanent internet connection or the creation of an online account. ONELO works offline and uses the MS Office suite, which is useful for creating image-based graphic charters.En administration, de nombreux documents divers sont produits. Il y a les notes de services pour informer le travailleur de changements importants, les ordres de missions en cas de déplacement prochain de ce dernier ou encore des attestations de participation délivrées suite à l’assistance à un événement. Assurer une bonne qualité de service revient souvent à produire des documents conformes, rapidement et avec un minimum d’erreurs. Peu d’administrations se permettent encore un fonctionnement manuscrit. Celles qui ont évolué vers la numérisation pèchent encore dans des pratiques désuètes. Dans ladite configuration, les informations distinctes sont encore saisies à la main, avec pour risque la modification inappropriée de la mise en forme finale des documents produits. En langue Myènè, ONège ELèle Ovono (ONELO) signifie respectivement Agile Facile Ingénieux. Notre outil ONELO est une stratégie unifiée de publipostage intelligent de documents administratifs. Si nous souhaitons par exemple produire 100 attestations de participation à un événement en quelques secondes, un 1er fichier MS Excel contiendra les coordonnées des 100 participants (noms, prénoms, email, …), un 2ème fichier MS Excel extraira uniquement du précédent les informations pertinentes (noms, prénoms) et un 3ème fichier MS Powerpoint regroupera la charte graphique (logo, signatures, nom de l’événement, …) au format image. Les données générées précédemment seront mises en forme dans un 4ème fichier MS Word dont l’impression (aux formats pdf ou papier) produira une attestation distincte aux 100 participants. ONELO, notre intelligence documentaire, a plusieurs intérêts. Nous pouvons produire beaucoup de documents en peu de temps, avec peu d’erreurs et une bonne résolution. Les documents d’ONELO peuvent être partagé en interne. Plusieurs outils sont similaires à ONELO mais nécessitent une connexion internet permanente ou la création d’un compte en ligne. ONELO fonctionne hors-ligne et exploite la suite MS Office, utile pour la création de charte graphique imagée
Stimulation de la voie des phénylpropanoïdes par application de phénylalanine chez la fraise et la tomate pour le contrôle de Botrytis cinerea
No full textInternational audienceLa fraise (Fragaria × ananassa) et la tomate (Solanum lycopersicum) sont deux cultures économiquement importantes sensibles au champignon Botrytis cinerea, responsable de la pourriture grise au champ et sur les fruits lors du stockage post-récolte. Face aux enjeux environnementaux et sanitaires liés à l’usage des fongicides de synthèse, stimuler les défenses des plantes via la voie des phénylpropanoïdes apparaît comme une alternative prometteuse (Ramaroson et al., 2022). Cette voie métabolique débute par la conversion de la phénylalanine (Phe) en acide trans-cinnamique via l’enzyme phénylalanine ammonia-lyase (PAL). Les composés phénoliques produits, notamment les flavonoïdes, stilbènes ou acides phénoliques, contribuent à la résistance aux pathogènes via des fonctions antioxydantes, structurelles et de signalisation (Saini et al., 2024). Des travaux récents montrent que l’application exogène de Phe peut induire une résistance accrue des plantes à des infections fongiques. L’application préventive d’une solution de 4,1 mM de Phe confère une résistance à B. cinerea sur feuilles détachées de tomate (Oliva et al., 2020). Sur fraise, des pulvérisations de 10 mM en pré- ou post-récolte diminuent la sensibilité des fruits sans affecter leur qualité (Pons et al., 2025). L’effet de la Phe semble indirect, via l’induction de métabolites de défense par la plante (Oliva et al., 2020), et son efficacité accrue proche de la récolte pourrait s’expliquer par une métabolisation rapide de la Phe en composés actifs (Kumar Patel et al., 2020). L’étude vise à (1) explorer l’effet de différents paramètres sur l’efficacité de la protection induite par la pulvérisation de Phe contre B. cinerea (dose, moment d’application, génotype de la plante, souches de l’agent pathogène) sur fraise et tomate, (2) développer une compréhension fine de la métabolisation de la Phe dans ces conditions, et (3) évaluer l’impact de ce traitement sur la qualité et la conservation des fruits
Selective estrogenic activity of Gouania longipetala Hemsl. (Rhamnaceae) aqueous extract through in vivo and in vitro antiproliferative approaches on MCF-7-167 and MDA-MB-231 cancer cells
No full textInternational audienceBackground and aim: Estrogens used in hormone therapy could lead to some cancers on uterus and mammary gland. Due to estrogenic activity, Gouania longipetala (GLO), is used to manage climacteric complaints and postmenopausal disorders. The present study aimed to assess mechanisms supporting GLO's activity on estradiol-sensitive tissues in vivo and, on breast cancer cells in vitro. The study was also about to characterize and identify Gouania longipetala active compounds.Methodology: Distilled water, estradiol and 45 and 180 mg/kg doses of G. longipetala, were orally administrated over 3 days to ovariectomized rats. Morphometric analyses were performed on vagina, uterus and breast. Then, a wide range of doses of G. longipetala was used to study the effects on MDA-MB-231 and MCF-7-167 cell proliferation. Binding to estrogen receptors was performed using transfection assay and, cell cycle was studied in MCF-7-167 cells using flow cytometry. Real-time PCR was assessed to quantify PgR, pS2, GREB1, CXCL12 and AREG gene expression. GLO phytochemicals were identified using liquid chromatography-mass spectrometry (LC-MS) analyses.Results: G. longipetala induced vaginal epithelial cell proliferation in ovariectomized rats, without significant activity on uterus and mammary gland. In vitro, GLO extract showed a powerful antiproliferative activity on MCF-7-167 and MDA-MB-231 cells, and even on E2-induced proliferation of MCF-7-167 cells, probably due to kaempferol-3-O-a-L-rhamnopyranoside, identified in the plant extract. GLO showed a slight involvement of binding to estradiol receptors and, decreased particularly PgR, GREB1 and CXCL12 E2-induced gene expression.Conclusion: Overall, Gouania longipetala aqueous extract exhibit selective activity on estradiol-sensitive tissues in vivo and, various effects against breast cancer cell proliferation and estradiol-induced proliferative effects in vitro. All taken into account, GLO may have a notably importance as therapeutic agent used in chemotherapy against E2-dependent cancer
A Unified Framework for Trend Uncertainty Assessment in Climate Data Records: Demonstration on Global Mean Sea Level
No full textInternational audienceTrends of essential climate variables are often estimated from climate data records to quantify changes in the Earth system. An understanding of the uncertainty in a trend is essential for accurately determining the significance of a trend and attributing its causes. Despite this importance, trend-uncertainty estimates rarely account for all known sources of uncertainty. Common approaches neglect measurement-system instability or neglect the impact of natural variability on trend uncertainty. Such neglect can result in over-confidence in trend estimates. This study addresses trend-uncertainty assessment, particularly the need to account for the combined effects of measurement instability and natural variability on the trend uncertainty. The study presents a novel, unified framework for trend estimation that combines available measurement uncertainty information with empirical modelling of natural climate variability to achieve a more accurate uncertainty estimate. The framework is demonstrated for a time series of global mean sea level observations, obtaining more realistic trend-uncertainty values. The framework is applicable to most other climate data records. Adopting this approach will enhance confidence in climate change analysis through more accurate trend-uncertainty assessment in climate studies
Weak trophic position–body mass relationships undermine simple size-spectrum models for coral reefs
No full textInternational audienceAbstract Unravelling food web dynamics across biological communities is a central goal of ecology. In size-structured ecosystems, the shape of trophic pyramids is often inferred from their size spectra—the distribution of biomass across body-mass classes. Size-spectrum analysis has become a popular tool to study ecosystem functioning in aquatic ecosystems, including coral reefs. However, the key assumption behind size spectra, that body size directly and positively correlates with trophic position, has rarely been evaluated in these systems. Here, we test this assumption by quantifying body mass, population densities and estimating trophic position from stable isotopes for 325 fish species across four Indo-Pacific locations. Consistent with prior studies, we found a positive relationship between biomass and body mass. However, weak and variable relationships between body mass and trophic position led to higher biomass in primary consumers than in predators, as expected in traditional bottom-heavy or diamond-shaped trophic structures. Our findings thus challenge previous reports of coral reef fish biomass prevalence in higher trophic levels (e.g. inverted biomass pyramids), supporting earlier suggestions that simple size-spectrum models do not adequately represent the trophic structure of reef fish communities
Fatal Attraction: Light Pollution Creates an Ecological Trap for Wild Fish
No full textInternational audienceEcological traps, poor‐quality habitats that attract animals, significantly threaten ecosystems but have rarely been documented in marine environments. In fish, early life‐history events, such as larval settlement, play a key role in shaping individual survival, population stability, and community interactions. While evidence suggests that late‐stage fish and invertebrate larvae exhibit a phototactic response, the effects of light pollution on larval settlement and survival remain poorly understood. Here, we simulated environmental light pollution on coral reefs using artificial light to examine its impact on fish settlement and post‐settlement consequences. We found that settlement was up to eight times higher onto corals exposed to light pollution compared to those under natural conditions. However, exposure to light pollution reduced recruit survival by half, desynchronized settlement from the full moon and reduced size at settlement. We identified key mechanisms contributing to increased mortality of individuals exposed to artificial light, including disruptions in resting metabolic rhythm and higher predation (due to heightened predator attraction). Additionally, we reveal potential trait compensation in body condition and maximum metabolic rate, traits linked to fitness. However, despite these potential compensatory mechanisms, light pollution functions as a severe ecological trap for fish, attracting individuals into suboptimal environments where they experience higher mortality. This underscores the need to regulate light pollution as a critical environmental stressor
Enquête qualitative sur la diaspora malgache en France
No full textForte de près de 170 000 personnes, cette communauté est pourtant peu connue en France. Une enquête permet de mieux comprendre la perception de l’appartenance à la diaspora malgache ainsi que la diversité des relations entre les membres
Global-scale AI-powered prediction of hydrogen seeps
No full textInternational audienceNatural hydrogen (H2) holds promising potential as a clean energy source, but its exploration remains challenging due to limited knowledge and a lack of quantitative tools. In this context, identifying active H2 seepage areas is crucial for advancing exploration efforts. Here, we focus on sub-circular depressions (SCDs) that often mark high H2 concentration in soils, thought to correspond to deeper fluxes seeping at the surface, making them promising targets for exploration. Coupling open-access Google Earth© images and in-field H2 measurement data, an artificial intelligence model was trained to detect seepage zones. The model achieves an average precision of 95 %, detects and maps seepage zones in new regions like Kazakhstan and South Africa, highlighting its potential for global application. Moreover, preliminary spatial analyses show that geological features control the distribution of H2-SCDs that can emit billions of tons of H2 at the scale of a sedimentary basin. This study paves the way for a faster and more efficient methodology for selecting H2 exploration targets
