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Reconstructing monthly 20th century salinity fields using a data-driven method and Argo data
No full textInternational audienceThe distribution of ocean salinity is influenced by factors such as ocean currents, freshwater exchanges with the atmosphere, continental inputs, and sea ice formation and melting. Salinity is a fundamental variable in the seawater’s equation of state, influencing density, ocean dynamics, and stratification. To understand its distribution and impact, salinity variability must be accurately estimated from in situ observations. In the 20th century, temperature observations were scarce, but salinity data were even more limited, as many instruments measured only temperature. In 2002, the implementation of the Argo observing system improved sampling and reduced the disparity between both variables. Salinity variability can now be better assessed from the 20-year Argo period. In this study, information from the Argo period and estimates of salinity covariability with temperatureare used to reconstruct monthly subsurface salinity fields. The reconstruction uses in situ measurements and employs the data-driven RedAnDA scheme, which combines Data Assimilation, Analog Prediction, and Reduced-space Interpolation, a method previously validated for temperature reconstruction. The coupling of temperature and salinity is achieved using density-weighted three-dimensional empirical orthogonal functions. The method is applied to the tropical Pacific to evaluate its ability to reconstruct variability at monthly, interannual and decadal timescales, with emphasis on ENSO-related variability, which is the primary mode of variability in the region. Compared to Optimal Interpolation results, salinity analysis by RedAnDA shows significant improvements. The results yield a salinity product that provides valuable insights into historical salinity variability, includingfresh pool displacements and salinity-driven stratification changes. Changes in subsurface salinity associated with El Ni˜no and La Ni˜na events are estimated from 1930 to 2001
Trajectories of Body Mass Index Changes and Their Association with Overall Survival in Breast Cancer Patients in Limoges, France
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Bidirectional Translations Between Observational and Topography‐Based Hydrographic Data Sets: MERIT‐Basins and the SWOT River Database (SWORD)
No full textInternational audienceThe recently launched Surface Water and Ocean Topography (SWOT) Mission is expected to provide transformative observations of water surface elevation, width, and slope and produce derived estimates of discharge for global rivers along rivers in the SWOT River Database (SWORD). However, the hydrographic representation of rivers in SWORD differs from hydrography data sets commonly used for modeling purposes, such as Multi-Error-Removed Improved Terrain (MERIT)-Basins. Here, we develop links between the river networks of SWORD and MERIT-Basins (MB) to enable interoperability between SWOT data products and hydrologic modeling frameworks. This data set, termed MERIT-SWORD, identifies a subset of ∼277,000 global MB river reaches that most closely represent the location and extent of the SWORD river network and establishes bidirectional, one-to-many translations between reaches in the two hydrographic data sets. The MERIT-SWORD data set serves to unite SWOT observations with river routing models, allowing for the seamless and standardized assimilation of SWOT vector products into global river simulations and the provision of improved a priori discharge estimates for SWOT discharge computation. Plain Language SummaryThe Surface Water and Ocean Topography (SWOT) Mission observes the water surface elevation, width, and slope of river reaches described in the SWOT River Database (SWORD). The location and extent of rivers in SWORD differ considerably from other river network data sets that are commonly used for hydrological modeling such as Multi-Error-Removed Improved Terrain (MERIT)-Basins. Here, we present and publicly share the MERIT-SWORD data set which links rivers in SWORD to rivers in MERIT-Basins (MB), and vice versa. These links between river reaches in the two data sets can allow for model simulations to be used as a first guess for SWOT measurements, and for observations from SWOT to be easily transferred to hydrologic modeling frameworks based on the MB river network for data assimilation
Spatial variation of future trends in Atlantic upwelling cells from two CMIP6 models
No full textInternational audienceEastern Boundary Upwelling Systems (EBUS) are characterized by wind-triggered upwelling of deep waters along the coast. They are hotspots of biological productivity and diversity and therefore have a high economic, ecological and social importance. In the past, different methods using surface data have been used to estimate upwelling. Recently, the IPCC has suggested directly assessing vertical velocities as a promising method. We use this method to study the two Atlantic EBUS from CMIP6 models from the HadGEM3-GC3.1 and the CNRM6-CM6 family, for both the historical period and a high-emission future scenario with spatial resolutions in the ocean component ranging from 1 • to 1/12 • . The two major upwelling regions are divided in subregions depending on their seasonality. The vertical transport index shows similar values to a wind-derived Ekman index. Directly evaluating upwelling from transport processes further provides information about the depth of the upwelling, which has previously been identified as an important factor for nutrient availability. We show that depending on the subregion of the upwelling system, different cell structures can be seen in terms of depth and distance to the coast of maximum velocities. When looking at possible future changes, high interannual variability limits the significance of the trends but could indicate a poleward shift of the upwelling regions. A detailed comparison of the spatial structures and the distinction in subregions is important to explain contradictory trends in previous works.</div
Leçons apprises du projet ANRS 12381 PRINCESSE en Côte d’Ivoire
No full textLeçons apprises du projet ANRS 12381 PRINCESSE avec témoignage des paires-éducatrices, des médecins du projet et de l’équipe de recherche
A scoping review of decision aids for pregnant women around childbirth: Do they improve decision quality, processes, and outcomes?
No full textInternational audienceBackground: Meaningful engagement of women in childbirth decisions is a growing priority in maternity care. Decision aids are tools designed to improve decision quality, decision-making processes quality, care behaviours, and health outcomes (quadruple aim). Objective: To map quantitative studies evaluating the effects of decision aids for women making decisions around childbirth. Methods: We searched MEDLINE, Cochrane DSR and CENTRAL, CINAHL, and EMBASE (January 1975-April 2025) for reviews, randomized controlled trials and controlled before-and-after studies that assessed the effect of decision aids for childbirth decisions. Results: 28 studies (11 reviews, 17 primary studies) met selection criteria. Most involved high-risk pregnant women and showed that decision aid improved the quality of decision and decision-making process. Positive impacts on care behaviour and health outcomes were more evident when decision aids were combined with other components and required discussions with healthcare providers. Discussion: Although limited, evidence suggests decision aids are more effective when women are prepared to use the tool and healthcare providers are actively involved. The review identified gaps in research targeting low-risk women in low-and middle-income countries and assessing women's value and preferences for shared decisionmaking. Conclusions: Decision aids around childbirth have the potential to meet women's needs in decision-making, appropriate use of care and perinatal health outcomes especially when they are prepared to use the tool and supported by healthcare providers. Future research should evaluate all four aim objectives to strengthen the evidence on the benefits of decision aids, especially for low-risk population and in low-and middle-income countries
Challenges and opportunities offered by geostationary space observations for air quality research and emission monitoring
No full textInternational audienceSpace-borne remote sensing of atmospheric chemical constituents is crucial for monitoring and better understanding global and regional air quality. Since the 1990s, the continuous development of instruments onboard low-Earth orbit (LEO) satellites has led to major advances in air quality research by providing daily global measurements of atmospheric chemical species. The next generation of atmospheric composition satellites measures from the geostationary Earth orbit (GEO) with hourly temporal resolution, allowing the observation of diurnal variations of air pollutants. The first two instruments of the GEO constellation coordinated by the Committee on Earth Observation Satellites (CEOS), the Geostationary Environment Monitoring Spectrometer (GEMS) for Asia and the Tropospheric Emissions: Monitoring of Pollution (TEMPO) for North America, were successfully launched in 2020 and 2023, respectively. The European component, Sentinel-4, is planned for launch in 2025. This work provides an overview of satellite missions for atmospheric composition monitoring and the state of the science in air quality research. We cover recent advances in retrieval algorithms, the modeling of emissions and atmospheric chemistry, data assimilation, and the application of machine learning based on satellite data. We discuss the challenges and opportunities in air quality research in the era of GEO satellites, and provide recommendations on research priorities for the near future
Improvement of Iron and β‐Carotene Bioaccessibility in Complementary Foods: Biofortification of Local Crops With Organic Residual Products and Microorganisms
No full textInternational audienceMicronutrient deficiencies remain a great public health challenge worldwide with iron, zinc, and vitamin A being the most problematic. It has been shown that biofortification through agronomic strategies can increase their micronutrient content, but data on the bioavailability remain limited. In Senegal, consumption of cereals and legumes is high, and orange‐fleshed sweet potato (OFSP), rich in β‐carotene, has been introduced a decade ago. The objective of the present work was to assess the bioaccessibility of iron, zinc, and β‐carotene in local complementary foods prepared with millet, cowpea, and OFSP alone or in combination, produced using different agronomic biofortification strategies. Organic residual products were used alone or in combination with microorganisms to produce the abovementioned crops that were used to prepare the complementary foods. Static in vitro digestion was performed to assess the bioaccessibility of the micronutrients, according to a harmonized protocol. The two organic residual products had different effect, as the cow dung alone was inefficient to increase iron and zinc contents as well as their bioaccessibility in millet porridges. However, the use of poultry litter alone or in combination with microorganisms increased iron bioaccessibility in cooked cowpea (27%–29%) compared to the non‐biofortified counterpart (9%). Surprisingly, bioaccessible β‐carotene was significantly higher (4.1%) in sample of mashed OFSP biofortified with the combination of the different agronomic strategies than in the others (1.4%–2.5%). Portions (150 g) of porridge prepared from the three biofortified crops would cover up to 100% of the daily vitamin A requirements of children aged 6–23 months. The use of a combination the most promising varieties of crops, together with the agronomic strategies, would be a complementary approach to sustainability limit micronutrient deficiencies in a context of monotonous diets
Lanthanide(III)-dependent hydration of the methanol dehydrogenase cofactor, pyrroloquinoline quinone
No full textInternational audienceThe mechanism by which pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenases (MDH), bearing either a Ca2+ or a lanthanide (Ln3+) ion in their active site, oxidize methanol has been intensely debated. In particular, the Ln3+-dependent activity of Ln-MDH remains poorly understood. The lack of experimental evidence represents a significant limitation to improve our understanding of these enzymes. In this work, we propose that insights on Ca- and Ln-MDH reactivity can be gained by examining a model reaction, the hydration of PQQ. Indeed, this reaction is similar to the first step of the putative methanol addition-elimination mechanism and is expected to be similarly influenced by the metal ion. The apparent affinity constants of PQQ for Ca2+ and Ln3+ were determined by UVvis absorption spectroscopy. Ln-PQQ complexes in aqueous solution were analyzed by steady-state and time-resolved fluorescence spectroscopy. The thermodynamic and kinetic parameters describing the equilibrium were obtained by variable-temperature and proton exchange spectroscopy (EXSY) NMR, as well as DFT calculations. Results demonstrated a Ln-dependent exchange rate for PQQ hydration equilibrium, the late and more Lewis acidic Ln3+ having the stronger impact
Diel changes in the expression of a marker gene and candidate genes for intracellular amorphous CaCO 3 biomineralization in Microcystis
No full textInternational audiencePhylogenetically diverse cyanobacteria biomineralize intracellular amorphous calcium carbonate (iACC) inclusions. This includes several genotypes of the Microcystis genus, a potentially toxic, bloom-forming cyanobacterium found worldwide in freshwater ecosystems. While we ignore the biological function of iACC and the molecular mechanisms driving their formation, this process may impact local geochemical cycles and/or be used for bioremediation strategies. Recently, a marker gene of this biomineralization pathway, named ccyA, was discovered. However, the function of the calcyanin protein encoded by ccyA remains unknown. Here, based on an RNA-Seq approach, we assess the expression of the ccyA gene in Microcystis aeruginosa PCC 7806 during a 24 h day/night cycle. The ccyA gene shows a clear day/night expression pattern with maximum transcript abundances during the second half of the night. This is consistent with the assumption that iACC biomineralization is related with photosynthesis and may therefore follow a day/night cycle as well. Moreover, several genes directly co-localized upstream and downstream of ccyA, on the same DNA strand show a similar expression pattern, including a cax gene encoding a calcium/proton exchanger and a gene encoding a protein with a domain also present in the N-terminal region of calcyanins in many iACC-forming cyanobacteria. This suggests that they all could be part of an operon, and may play a concerted role in iACC formation. Last, several other genes involved in carbon concentrating mechanisms and calcium transport show an expression pattern similar to that of ccyA. Overall, this study provides a list of candidate genes that may be involved in the biomineralization of iACC by cyanobacteria and whose role could be, in the future, analyzed by biochemistry and genetics approaches