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Avis du CNGOF concernant les accouchements instrumentaux par ventouse obstétricale
No full textNational audienceLa commission d’obstétrique du CNGOF, saisie par le CNP GOGM à la demande de l’ANSM, a examiné la sécurité d’utilisation des ventouses obstétricales. L’accouchement instrumental peut être réalisé pour écourter l’expulsion, notamment en cas de ralentissement du rythme cardiaque fœtal. Les instruments disponibles sont la ventouse, le forceps et les spatules, le choix dépendant de la situation et de l’opérateur. En France, environ 12 % des naissances sont instrumentales, un taux stable depuis 2016. La ventouse est utilisée dans environ deux tiers des cas, proportion similaire à celle observée dans la plupart des pays européens et au Canada, mais supérieure à celle des États-Unis. La ventouse agit par dépression sur le scalp fœtal, permettant une traction contrôlée et sécurisée. Les complications maternelles (lésions périnéales, hémorragies) et néonatales (notamment hémorragies intracrâniennes) sont rares et comparables à celles observées lors des césariennes en cours de travail. Les études épidémiologiques ne mettent pas en évidence de surrisque neurologique ou de séquelles à long terme chez les enfants nés par ventouse. Comparée au forceps, la ventouse réduit la morbidité maternelle, notamment le risque de lésion du sphincter anal, sans différence notable sur la santé néonatale globale, hormis un léger sur-risque de céphalhématome ou d’ictère. Aucune différence n’est observée selon l’expérience de l’opérateur. En conclusion, l’accouchement instrumental par ventouse qui fait partie des techniques recommandées par le CNGOF, constitue une alternative pertinente à la césarienne à dilatation complète
Physical Processes Driving Carbon Subduction in the Southern Ocean in an Eddy‐Permitting Model
No full textInternational audienceThe Southern Ocean south of 35°S represents a small source of natural inorganic carbon for the atmosphere but a major sink of anthropogenic carbon. The magnitude of the inorganic carbon sink, and the sequestration of inorganic and organic carbon strongly depend on the rate at which they are subducted below the mixed layer. We use a global ocean model at 0.25°resolution to quantify the drivers of the pathways of total and anthropogenic dissolved inorganic carbon (DIC) and organic carbon (OC) across and within the time-varying mixed layer of five physically consistent regions of the Southern Ocean over the period 1995-2014. Total DIC is brought into the mixed layer through obduction south of the Antarctic Circumpolar Current (ACC) and subducted north of the ACC, resulting in a net obduction of 11.2 PgC/year, with advective processes being responsible for about two-thirds of the total transfer. Anthropogenic carbon is brought to the mixed layer through the ocean surface in all regions but mainly subducted north of the ACC, with the subduction (1.05 PgC/ year) being achieved through both advection and diffusion, each dominating respectively north and south of the Subantarctic Front. Two thirds of the organic carbon are subducted through the gravitational pump (1.9 PgC/ year) and one-third through physical transfer (0.9 PgC/year), with an equivalent contribution from advection and diffusion. At the local scale, advective fluxes largely dominate other physical processes in transferring carbon across the base of the mixed layer, and are found to be increased near topographic features and boundary currents
Géo-ingénierie climatique : comment et avec quelles conséquences ?
No full textInternational audienceDevant la difficulté des politiques publiques à faire diminuer les émissions de gaz à effet de serre et l'amplification du réchauffement climatique et ses impacts associés, certains poussent à la mise en place de mesures de géo-ingénierie, qui visent à réduire les impacts du changement climatique par des modifications du système climatique à grande échelle. Pourtant, ces mesures ne sont pas sans effets indésirables, et des promesses inconsidérées sur leur potentiel pourraient ralentir la mise en place des réductions d'émissions
Oxidation of photochemical organic hazes: a prebiotic source of oxygen-bearing organics in Titan atmosphere and the Early Earth?
No full textInternational audienceMass spectra of unidentified oxidation products of titan tholins analysed by GC-MS. The compounds are numbered from 1 to 36 by increasing retention times. The numbers at the end of the filenames correspond to the main fragment associated with each compound. GC-MS analyses were performed using MTBSTFA derivatization prior to injection. As a result, the compounds in this database may contain TBDMS silyl group in their structure. Since mass spectra databases for MTBSTFA-derivatized compounds remain incomplete, these compounds could not be identified using existing databases
Investigating the ADOS-2 calibrated severity score: insights from the ELENA cohort
No full textInternational audienceIntroduction The Autism Diagnostic Observation Schedule (ADOS-2) is widely used to assess Autism Spectrum Disorder (ASD) symptom severity. To allow comparisons across modules and developmental levels, the Calibrated Severity Score (ADOS-CSS) was developed. However, concerns have been raised about potential changes in the measurement signal introduced by the calibration process, which may alter the signal captured by the ADOS-2 raw scores (ADOS-RS). Methods Using longitudinal data from the ELENA cohort ( N = 145 children with ASD assessed at baseline and after 3 years), we examined the psychometric properties of the ADOS-CSS and ADOS-RS. The Social Responsiveness Scale (SRS-2) was used as an external reference. Bootstrap resampling was used to estimate means and 95% confidence intervals (CIs). Results Variance explained by module, age, and IQ was higher for the ADOS-RS (R 2 = 0.45, 95% CI: 0.38–0.52) than for the ADOS-CSS (R 2 = 0.16, 95% CI: 0.10–0.24). Stability of ASD severity scores over time was lower for the ADOS-CSS ( ρ = 0.34, 95% CI: 0.23–0.45) than for the ADOS-RS ( ρ = 0.60, 95% CI: 0.51–0.68). Correlations with SRS-2 scores were consistently lower for ADOS-CSS ( ρ = 0.14, 95% CI: 0.06–0.22) than for ADOS-RS ( ρ = 0.24, 95% CI: 0.17–0.32). Similar patterns were observed for change scores (Δ indicating score differences between baseline and follow-up): ΔSRS-2 correlated more strongly with ΔADOS-RS ( ρ = 0.19, 95% CI: 0.09–0.28) than with ΔADOS-CSS ( ρ = 0.13, 95% CI: 0.06–0.21). Differences between ADOS modules were reflected in SRS-2 and ADOS-RS, but markedly attenuated in ADOS-CSS, suggesting that calibration reduces module-related variance but also induces changes in the measurement signal that may affect sensitivity to individual differences. Discussion While the ADOS-CSS facilitates standardized comparisons across modules, clinicians and researchers should be aware of potential distortions in the measurement signal associated with the calibration process. Clinical Trial Registration NCT02625116
D4Xgui: A tool for baseline correction and standardization of carbonate clumped isotope raw data
No full textInternational audienceAccurate and precise mass spectrometric determination of ppm-ppb quantities of mass 47-49 clumped isotopo logues of carbonate-derived CO 2 , expressed as Δ 47 -Δ 49 values, requires advanced processing schemes. Here, we introduce D4Xgui, a user-friendly processing tool that allows correction of mass-spectrometric raw intensities for a pressure baseline artifact, before standardization is carried out using D47crunch. D4Xgui enables rapid processing of multi-session data under consideration of full error-propagation, interactive visualization of results including tools for data quality assurance, calculation of carbonate crystallization temperature from finally pro cessed data, and rapid re-evaluation of datasets with revised processing parameters. Though the primary focus of D4Xgui is on carbonates it can also be applied to the correction of mass spectrometric raw data obtained on CO 2 from other sources.</div
Tracking surface ozone responses to clean air actions under a warming climate in China using machine learning
No full textInternational audienceSurface ozone, a major air pollutant with important implications for air quality, ecosystems, and climate, shows long-term trends shaped by both anthropogenic and climatic drivers. Here, we developed a machine learning-based approach, namely the fixed emission approximation (FEA), to decouple the effects of meteorological variability and anthropogenic emissions on summertime ozone trends in China under the clean air actions. Anthropogenic emissions drove an approximately +23.2 ± 1.1 µg m -3 increase in summer maximum daily 8 h average ozone during 2013-2017, followed by an approximately -4.6 ± 1.5 µg m -3 decrease between 2017 and 2020 in response to strengthened emission controls. In contrast, meteorological anomalies, including heatwaves and rainfall conditions, emerged as substantial drivers of ozone variability during 2020-2023. Satellite-derived formaldehyde-to-nitrogen dioxide ratios revealed widespread urban volatile organic compounds-limited regimes for ozone production, with a shift toward nitrogen oxides-limited sensitivity under influence of heatwaves. Extending the FEA framework to assess long-term climate influences from 1970 to 2023, we find that sustained climate warming has driven a substantial increase in urban summertime ozone in China. These results demonstrate that climate change was increasingly offsetting the benefits of emission reductions and highlight the need for integrated ozone mitigation strategies that jointly address emission controls and climate adaptation in a warming world.</div
Characterization of Titan’s Northern Polar Terrains From Inversion of Cassini RADAR Data
No full textInternational audienceWe investigated the surface geophysical properties of Titan through a multiangular backscattering analysis of Cassini Ku-band radar data acquired in altimetry, SAR, scatterometry, and radiometry modes. We test quasi-specular scattering models in combination with a volume scattering formulation to model the backscatter coefficient as a function of incidence angle over specific areas identified from topographic and radar imaging data. From data inversion, we found that the exponential model provides the best fit to the observed data. We present our results in terms of effective permittivity, surface roughness, and volume scattering albedo across different backscattering uniform regions at Titan’s northern hemisphere, where both radar-bright and -dark terrains have been observed from radar images acquired during the mission. Our results indicate that these bright regions belong to a large low-lying plain made of material with a relatively high dielectric constant, high-volume scattering albedo, and moderate wavelength-scale roughness inferred from the model inversion. In contrast, dark regions are consistent with solid hydrocarbons accumulations, reaching thicknesses of up to hundreds of meters above this plain, and they exhibit a lower dielectric constant, lower volume albedo, and slightly higher wavelength-scale surface roughness together with additional higher meter- to tens-of-meter-scale roughness inferred from altimetry. Finally, we propose some of the most probable scenarios based on a list of candidate materials that may be present at the surface of Titan. Although our analysis focuses on a specific, albeit extensive, region near the North Pole, our findings may offer broader insights into the global distribution of complex organics on Titan surface, which are likely superimposed on top of a mixture of ice and organic material
Comparison of the trace and major elements distribution in river waters from large-scale watersheds of the Tibetan Plateau
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Neuroethical Issues in Times of Health Crisis. What Roles for Neurosciences, IA, Neurotechnologies?<strong> </strong>
No full textHow can neuroscience help everyone to live and care for our confined brains? Understanding and studying human behaviour allows us to measure the impact of such confinement on each of us and to identify those who need help. The challenges are to understand the psychological repercussions following confinement and to understand how neuroscience and neurotechnology can be very interesting tools for dealing with the health crisis. Neuroscience is changing our traditional philosophical and ethical views by providing information about the biological basis of our moral behaviour. The exception of the brain is at the heart of neuroethical thinking and discourse. Neuroethics is an interdisciplinary discipline placed at the intersection between the human sciences and the neurosciences, and aims to help understand how knowledge and research in neurosciences and neurotechnologies will affect the future of society, their impact on humans, relationships, daily life, the labour market ... but also how they can help and provide solutions and answers to the questions of citizens in a health crisis. But it's a double-edged sword, collecting and analyzing brain data in real time seems to be increasingly simple and within everyone's reach, without having the hindsight of the real meaning of these data, allowing one day to read people's thoughts, control them and manipulate them. It is becoming clear that the boundaries between medical and non-medical uses of neuroscience and neurotechnology are becoming very porous, inviting us to reflect on neuroethical issues in order to put safeguards on these uses