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BEBOP VII. SOPHIE discovery of BEBOP-3b, a circumbinary giant planet on an eccentric orbit
No full textInternational audiencePlanetary systems orbiting close binaries are valuable testing grounds for planet formation and migration models. More detections with good mass measurements are needed. We present a new planet disco v ered during the BEBOP surv e y for circumbinary exoplanets using radial velocities. We use data taken with the SOPHIE spectrograph at the Observatoire de Haute-Pro v ence, and perform a spectroscopic analysis to obtain high precision radial velocities. This planet is the first radial velocity detection of a previously unknown circumbinary system. The planet has a mass of 0.56 M Jup and orbits its host binary in 550 d with an eccentricity of 0.25. Compared to most of the previously known circumbinary planets, BEBOP-3b has a long period (relative to the binary) and a high eccentricity. There also is a candidate outer planet with a ∼ 1400 d orbital period. We test the stability of potential further candidate signals inside the orbit of BEBOP-3b, and demonstrate that there are stable orbital solutions for planets near the instability region which is where the Kepler circumbinary planets are located. We also use our data to obtain independent dynamical masses for the two stellar components of the eclipsing binary using high resolution cross-correlation spectroscopy, and compare those results to a more traditional approach, finding them compatible with one another
Synergistic pathogenicity between Herpesvirus and Vibrio aestuarianus in killing juvenile oysters during spring in natural conditions
No full textInternational audienceYoung oysters of Pacific oyster Magallana (Crassostrea) gigas are regularly impacted by summer mortalities since 2008, caused by the infection by the Ostreid herpesvirus 1 (OsHV-1) when seawater temperature increases in summer. Adult oysters rather suffer from a vibriosis caused by the bacterial primary pathogen Vibrio aestuarianus francensis. Although these diseases are now well described, little is known about their contribution and possible synergy in natural mortality events of juvenile oysters. Using an in-situ approach conducted in the Thau lagoon, we investigated the potential implication of Vibrio aestuarianus in the juvenile oyster's mortality, as well as the virus OsHV-1, throughout a large sampling period from winter to late summer, after the mortality event. We further determined their respective effects on the microbial abundance and diversity on alive and moribund oysters. We demonstrated that microbiomes are dynamic throughout seasons and tend to become more similar in spring with a dominance of Mycoplasmataceae in alive oysters. Surprisingly, our data highlighted the prevalence and high loads of Vibrio aestuarianus in all moribund oysters. In contrast with the literature, we found that the microbial communities of moribund juvenile oysters were significantly influenced by both Vibrio aestuarianus and the virus OsHV-1. The moribund bacterial indicators were detected in abundance during mortalities in the surrounding environment of oyster farms and further (700 m far). These results highlight the connectivity between the different compartments of the lagoon and raise questions about the potential spread of the primary pathogen Vibrio aestuarianus from adult to juvenile oysters in farming areas located in lagoons
Explorer les parcours de vie et les trajectoires de soins des femmes immigrées originaires d’Afrique subsaharienne atteintes d’endométriose et installées en France
No full textInternational audienceThe diagnostic journey for endometriosis is a long and winding road. Years of consultations, minimised pain, missed diagnoses. This reality affects millions of women in France. While the diagnostic journey for endometriosis is common, it does not affect all women in the same way. For immigrant women from sub-Saharan Africa living with endometriosis in France, their journey to diagnosis and treatment may involve additional obstacles, such as language barriers, administrative precariousness and socio-economic vulnerability. We are taking a qualitative approach, conducting around forty biographical interviews in the Île-de-France region. These interviews will be conducted with women born in sub-Saharan Africa who have been diagnosed with endometriosis and live in the Île-de-France region. These women's life stories will provide insight into their experiences, their relationship with the healthcare system, the obstacles they encounter, the strategies they use to adapt, as well as the resources they mobilise and their experiential knowledge. Our findings should enable us to formulate operational recommendations for adapting prevention programmes and improving the diagnosis and management of endometriosis in specific populations. Endometriosis should not be considered solely as a biomedical issue; sufferers may be affected by social inequalities that influence their care pathways and quality of life.Le parcours diagnostic de l'endométriose est un parcours d'errance. Des années de consultations, de douleurs minimisées, de diagnostics manqués. Cette réalité touche des millions de femmes en France. Si l'errance diagnostique de l'endométriose est commune, elle ne touche pas toutes les femmes de la même manière. Pour les femmes immigrées d'Afrique subsaharienne atteintes d’endométriose en France, leurs parcours diagnostic et de prise en charge de l’endométriose peut avoir d’autres obstacles à savoir des barrières linguistiques, une précarité administrative, une vulnérabilité socio-économique. Nous adoptons une approche qualitative, avec la réalisation d’environ quarante entretiens biographiques, en Région Île-de-France. Ces entretiens seront menés avec des femmes nées en Afrique subsaharienne, diagnostiquées d'endométriose et vivants en Région Île-de-France. Les récits de vie de ces femmes permettront de comprendre leur vécu, leur rapport au système de santé, les obstacles qu’elles rencontrent, les stratégies qu’elles déploient pour s’adapter, mais aussi les ressources qu’elles mobilisent et leurs savoirs expérientiels. Nos résultats doivent permettre de formuler des recommandations opérationnelles pour adapter les programmes de prévention, améliorer le diagnostic et la prise en charge de l’endométriose chez les populations spécifiques. L’endométriose ne doit pas être considérée seulement comme un enjeu biomédical ; les personnes malades peuvent être marquées par des inégalités sociales qui influencent leurs trajectoires de soins et leurs qualité de vie
The Freshwater Origin of a Brackish Submarine Spring Inferred from a Long-Term Stable Isotope Survey: The Port-Miou Karstic Spring (S-E France)
No full textInternational audienceThe submarine Port-Miou spring (S-E of France), represents a major regional discharge, draining a catchment area of around 400 km² with pronounced relief up to 1148 m a.s.l., close to highly urbanized coastal areas (Marseille). The spring has a brackish salinity, rising up to 14 psu during low flow and diluted until 2 psu during floods. The aim of this study is to better understand the origin of freshwater and the salinization mechanism, using the results of a long-term stable geochemical survey of the brackish Port-Miou spring and of the surrounding aquifers. Since 2012, water salinity and temperature are measured in situ and water sampling was performed unevenly in springs and boreholes for stable isotopes analysis (δ18O and δ2H). Based on a twoendmembers mixing between continental freshwater and seawater, we propose a method for calculating the isotopic composition of the freshwater feeding the Port-Miou spring. Results show δ 18 O values varying between -7.7 and -6.5 ‰ for the reconstructed composition of freshwater. These variations are discussed with regards to the compositions of regional aquifers. A relative stability is evidenced for the isotopic composition of the freshwater endmember during low flow, consistent with the regional deep aquifers. However, during high water events the freshwater endmember shows a more variable isotopic composition, which suggests the contribution of different water sources
The noose is tightening on parasites: how environmental nucleic acids (RNA/DNA) help us identifiy the different forms of freshwater parasites
No full textInternational audienceEnvironmental DNA led to significant advances in the detection of pathogens, including those that are microscopic, endoparasitic, or present at low concentrations, as well as their hosts in aquatic environments. This has enabled the characterisation of community composition, species interactions, and distribution patterns. However, DNAs can persist in ecosystems and do not inform on the physiological status of the targeted organisms (i.e. death or living organism, parasitic life stage). Further investigation is thus required to ascertain the precise nature of the signals detected in water and what they can tell us about host/pathogen interactions. Environmental RNA (eRNA), due to its presumed rapid degradation, could serve as a valuable tool for identifying active organisms, while offering a unique potential for epidemiological monitoring of infectious life stages through the analysis of their specific transcripts. Here we focus on the development of ARNe markers targeting the miracidia and cercariae of Schistosoma mansoni, two infectious stages with distinct epidemiological roles in the complex life cycle of this trematode. We evaluated the specificity, sensitivity and quantification capacity of these markers, first in silico and then experimentally. We quantified ADNe/ARNe ratio and RNAs specific to miracidia and cercariae from water where these two S. mansoni life-stages were present at different ratios (10/90, 50/50, 90/10). We also experimentally studied the dynamics of RNAs and DNAs degradation in aquaria in which the cercariae/miracidia ratio was set to 50/50 after 24h, 48h and 120h. Precise quantification of each of these life-stages would represent a significant step forward in the biomonitoring of complex-cycle pathogens in freshwater, going beyond simple species detection. Furthermore, this study provides new insights on longevity and our ability to quantify eRNAs. It also highlights the usefulness of eRNA in pathogen ecology and epidemiology
No evidence for a 10-m historical tectonic uplift at Mangalia, (Romanian Black Sea coast): comment on Drăguşin et al. (2025)
No full textInternational audienceDrăguşin et al. (2025) interpreted deposits at Mangalia (Romania) as evidence of a two-phase tectonic event (~ 14 m subsidence and uplift) during the 18th–19th centuries. Based on multi-proxy data from the same site, we show that this scenario is inconsistent with regional tectonics, stratigraphy, and archaeology. The deposits instead record the gradual infill of a coastal depression episodically affected by extreme marine incursions
Two contrasting swamp forest succession pathways in central Congo Basin peatlands
No full textInternational audienceThe central Congo Basin (CCB) contains one of the world's most extensive regions of tropical peat swamp forest, occupying interfluves and floodplains surrounding the Congo River and its tributaries. The region is dominated by hardwood and Raphia-palm forests. Little is known about how and when these forests developed. We investigate peatland ecosystem and forest development via pollen and δ13CTOC analysis on peat cores from four study sites, two on floodplains to the east of the Congo River, and two on interfluves to the west of the Congo River. We present 81 14C dates on bulk peat samples from four peat cores to show that peat initiation and forest establishment occurred at three sites before or during the Last Glacial Maximum (LGM), at 26,750 calendar years before present (cal yr BP) (Bolengo), 19,600 cal yr BP (Ekolongouma) and 19,400 cal yr BP (Bondamba), and later at 13,350 cal yr BP (Boboka) at a fourth site. The three oldest dates support earlier hypotheses that the CCB may have been a dynamic refuge for rainforest taxa during the LGM. The pollen records from the four sites show two contrasting patterns of vegetation succession following peat initiation: the interfluvial peatlands developed from an open herbaceous wetland; the river floodplain peatlands developed from a hardwood swamp forest. All four sites eventually transitioned to a mixed swamp forest containing Raphia and Uapaca trees. Differences in the timing of vegetation transitions between sites suggest that autogenic (within-site) processes are important drivers of vegetation succession in these peatlands, overlain to varying degrees by allogenic (climatic) drivers. Overall, the comparative analysis of pollen records from four sites within the CCB reveals two contrasting trajectories of forest development—one associated with interfluves and the other with river floodplains—driven by a combination of autogenic and allogenic processes. Our findings highlight the biological diversity and complexity of the CCB peatlands, and their sensitivity to climatic change. Reduced precipitation in the Late Holocene affected peat accumulation and forest composition at all sites, with some sites being more sensitive than others. This study provides important context for efforts to protect and conserve the CCB peat swamp forests by demonstrating their sensitivity to environmental stress in the past
Farmers hold diverse and connected values towards crops
No full textAll the data and R scripts used for analyses are shared here: https://github.com/AntoineDoncieux/crops_values_reviewInternational audienceConsiderations of yield and profit often drive decision-making in agriculture, but these are not the only values farmers ascribe to crops. Recognizing the multiple values farmers use to choose crops and their management holds potential as a leverage point for sustainable transformations. To assess the diversity of values attributed by farmers towards individual crops, mixes of crops, and agroecosystems, we conducted a literature review of 125 studies published between 2010 and 2022. We analyzed 1,716 unique reports of value ascribed by farmers to 135 crop species across 67 countries and 20 agroecosystems. Farmers' values towards crops are diverse and connect economic, agronomic, social, cultural, and ecological dimensions of agriculture. While yield and profit are the values most frequently reported by farmers, social and cultural values, such as identity and cultural preferences, are also often considered as vitally important. Although most reviewed studies examined smallholder farmers and values assigned to single crops, results indicate that values vary across farm size and market orientation and across crop types. We also show that external forces, such as markets, policies, and climate change, interact with farmers' values to influence their management of crops. Finally, this review shows that researchers in different disciplines highlight different values, and that the complexity underpinning farmers' decisions about crops can be enlightened by interdisciplinary approaches. The article thus supports and extends the recommendation of IPBES to integrate diverse values linking farmers and crops into research and policy
L’influence des systèmes d’indemnisation dans les choix résidentiels en contexte de risques côtiers en France et au Québec
No full textDespite increasing coastal erosion and flooding in the context of climate change, the appeal of living by the sea remains strong in both France and Quebec. Understanding what drives individuals to purchase or remain close to the shore is becoming a key issue for public authorities seeking to counter this trend and promote adaptation policies such as relocation. As part of a Franco-Quebec research project (ARICO), this jointly supervised doctoral thesis investigates a factor still largely overlooked in geography: the influence of compensation systems on coastal residential choices. In both France and Quebec, part of the costs associated with coastal risks are mutualized through solidarity-based compensation systems in which the state plays a central role. The hypothesis is that these systems may encourage individuals to purchase or remain by the sea, by shifting the financial burden of risk from individuals to the broader community.To examine this hypothesis, a multi-scale survey was conducted in France and Quebec, combining interviews with 54 private- and public-sector stakeholders and questionnaires completed by 371 coastal homeowners. The cross-analysis of interview and questionnaire data, and the France-Quebec comparison, reveal that these systems influence residential choices in different ways, depending on how solidarity is balanced with individual responsibility. This finding argues not for the abandonment of solidarity, but rather for a redefinition of how it is implemented.En dépit de l’accentuation de l’érosion et la submersion côtières dans un contexte de changements climatiques, l’attrait pour la vie en bord de mer demeure prégnant en France et au Québec. Comprendre ce qui motive les choix des particuliers à acheter ou à rester proches du rivage devient un enjeu pour les pouvoirs publics afin de tenter d’infléchir cette tendance au profit de politiques d’adaptation comme la relocalisation. Dans le cadre d’un projet de recherche franco-québécois (ARICO), cette thèse en cotutelle interroge un facteur encore peu exploré en géographie : l’influence des systèmes d’indemnisation dans les choix résidentiels côtiers. En France et au Québec, une partie des coûts associés aux risques côtiers est mutualisée au travers de systèmes d’indemnisation solidaires où l’État intervient. L’hypothèse est donc que ces systèmes pourraient encourager les particuliers à acheter ou à rester en bord de mer, en faisant reposer les conséquences financières de ces risques sur la collectivité et non sur l’individu.Pour étayer cette hypothèse, une enquête, à différentes échelles de la France et du Québec, a été menée par entretiens auprès de 54 acteurs des secteurs privés et publics et par questionnaire auprès de 371 propriétaires de résidences côtières. L’analyse croisée des données recueillies par entretien et par questionnaire, et la comparaison France-Québec, montrent que ces systèmes influencent différemment les choix résidentiels, en fonction de la manière dont la solidarité est articulée à la responsabilité individuelle. Ce constat plaide non pas pour l’abandon de la solidarité, mais pour une redéfinition de ses modalités
