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Stronger Sensitivity of Plant Photosynthesis to Rising CO2 in High Elevation Ecosystems
No full textInternational audienceThe CO 2 ‐fertilisation effect (CFE) on vegetation productivity is the major driver of the enhanced land carbon sink in recent decades. CFE theoretically increases with elevation due to the higher sensitivity of carboxylation to an increase of CO 2 under lower CO 2 partial pressure, but the elevation‐dependent CFE pattern has been largely overlooked. By conducting a 6‐year CO 2 enrichment experiment (+100 ppm) in an alpine grassland, we show that elevated CO 2 increased gross primary production (GPP) by 25.5% ± 4.6%. Water availability and plant biomass allocation modulates CFE during different seasons. A global synthesis of 10 CO 2 enrichment experiments reveals that CFE increased with elevation. The satellite‐based EC‐LUE model also demonstrates a positive global elevation‐dependent CFE pattern, albeit substantially weaker than that from experimental observations. Current terrestrial biosphere models, however, could not represent the elevation‐dependent pattern, highlighting the need to improve the representations of plants' elevational physiological adaptation to rising CO 2 in models
Les brumes de Titan : des grains organiques formés dans la haute atmosphère ionisée
No full textInternational audienceLe système climatique de la lune de Saturne, Titan, est gouverné par la production intense d'aérosols organiques dans sa haute atmosphère, sous l'effet de rayonnements UV et de particules énergétiques. Ce phénomène s'est aussi certainement produit sur Terre au moment de l'apparition de la vie, avant la Grande Oxygénation. Ces deux points motivent fortement les recherches sur les processus de formation et d'évolution des aérosols dans l'atmosphère de Titan
Idealized modeling of stratospheric aerosol injection deployment scenarios with two non-cooperative actors
No full textInternational audienceThis code is the version of https://github.com/OB-IPSL/two-actor-SRM used in the article by Määttänen et al. (2025) in Environmental Science: Atmospheres of the Royal Society of Chemistry (A. Määttänen, F. Ravetta, J. Bureau, T. Lurton and O. Boucher, Environ. Sci.: Atmos., 2026, DOI: 10.1039/D5EA00022J. The article investigates solar radiation management scenarios of two non-cooperative actors deploying stratospheric aerosol injection (SAI) through idealized experiments. The repository includes the codes for a four-box Energy Balance Model capable of predicting hemispheric temperatures and monsoon precipitation and the coupled PI-controller. A short README is included
The odyssey of the black hole low mass X-ray binary GX339-4: Five years of dense multi-wavelength monitoring
No full textInternational audienceWe present the longest and the densest quasi-simultaneous radio, X-ray and optical campaign of the black hole low mass X-ray binary GX339-4, covering five years of weekly GX339-4 monitoring with MeerKAT, Swift-XRT and MeerLICHT, respectively. Complementary high frequency radio data with the Australia Telescope Compact Array are presented to track in more detail the evolution of GX339-4 and its transient ejecta. During the five years, GX339-4 has been through two "hard-only" outbursts and two "full" outbursts, allowing us to densely sample the rise, quenching and re-activation of the compact jets. Strong radio flares were also observed close to the transition between the hard and the soft states. Following the radio flare, a transient optically thin ejection was spatially resolved during the 2020 outburst, and was observed for a month. We also discuss the radio/X-ray correlation of GX339-4 during this five year period, which covers several states in detail from the rising phase to the quiescent state. This campaign allowed us to follow ejection events and provide information on the jet proper motion and its intrinsic velocity. With this work we publicly release the weekly MeerKAT L-band radio maps from data taken between September 2018 and October 2023
Dissolved organic matter dynamics and chemistry under fungal activity: A microcosm incubation with litter differentially 13C-labelled
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Cognitive and Psychosocial Outcome in Children and Adolescents Treated for Extracranial Malignant Solid Tumors and Lymphomas in the RISK‐N Study
No full textInternational audienceObjective: Recent studies show evidence of cognitive and psychosocial impairments and reduced quality of life (QoL) in adult survivors of childhood extracranial solid tumors and lymphomas, but limited research has addressed these issues in pediatric populations.Study Design: The French RISK‐N prospective study (2014–2021) evaluated 278 survivors of extracranial solid tumors or lymphomas (47% female, mean age at diagnosis and assessment: 6.2 and 11.7 years). Patients with pre‐existing neurological conditions were excluded. Sociodemographic, disease‐related, and treatment data were collected. Cognitive performance was assessed using Wechsler Intelligence Scales for Children (WISC‐IV, WISC‐V). Psychosocial outcomes included parent and/or patient‐reported executive functions (Behavior Rating Inventory of Executive Function), behavior (Conner's Parent Rating Scale), QoL (Pediatric Quality of Life Inventory), fatigue (Multidimensional Fatigue Scale), and depression (Children's Depression Inventory). Information on schooling and educational/rehabilitative interventions was also recorded.Results: Diagnoses included lymphoma (25%), nephroblastoma (19%), neuroblastoma (19%), osteosarcoma (7%), other sarcomas (18%), and other tumors (12%). Mean Full Scale Intellectual Quotient [ M (SD) = 99.44(15.62)] was as expected in the general population [ M (SD) = 100(15)], but the WISC‐IV Perceptual Reasoning Index was slightly lower [ M (SD) = 95.4(15.0), <1.5 SD 14%]. Parent‐ and self‐reports indicated greater executive dysfunction, inattention, fatigue, and reduced QoL. In multivariable regression models, poorer cognitive outcomes were associated with lower parental education and developmental/learning delays before diagnosis.Conclusions: Objective cognitive deficits were uncommon among pediatric cancer survivors, contrasting with a relatively high level of subjective cognitive and psychosocial complaints, highlighting the need for systematic screening and tailored clinical interventions
Isolated multiple minute digitate keratoses of the penile shaft in an adult
No full textInternational audienceWe report the first documented case of adult-onset Multiple Minute Digitate Keratoses (MMDK) localized exclusively to the penile shaft. Dermoscopic and histopathological examination revealed distinctive features that assisted in excluding other keratinization disorders. This unusual presentation expands the clinical spectrum of MMDK and highlights the importance of careful clinicopathological correlation in genital keratoses
Accounting for exposure in 3D spatiotemporally contiguous heatwaves in Europe 1975-2024
No full textHeatwaves are becoming more common, intense, and widespread as climate change accelerates, increasing their effects on infrastructure, economies, and health. However, heatwaves' material and human effects cannot be adequately captured by their meteorological characteristics alone. In order to address this challenge, we propose a new heatwave index (HWMId_pop), which combines population exposure and meteorological data to provide a more accurate representation of heatwave impacts. Heatwaves are detected using a 3D-event framework, which considers heatwaves as spatiotemporal events that transcend conventional, spatially limited definitions. We validate this new index by comparing it to the impacts of heatwaves recorded in the EM-DAT disaster database for Europe from 1975 to 2021. Our results show that HWMId_pop outperforms traditional heatwave indices by correlating more closely with mortality data and demonstrating a superior ability to identify significant heatwave events. We also examine trends in several commonly used heatwave indices between 1975 and 2024, finding that our proposed index shows a significant increasing trend. We highlight that the increasing affected population, driven by the expanding spatial extent of heatwaves and the rising European population, poses growing health risks. Additionally, we argue that this index can be used as a guide to carry out gap-filling in heatwaves impacts database such as EM-DAT
Adaptive LASSO Quantile Regression with Fixed Effects
No full textInternational audienceQuantile regression with fixed effects for longitudinal data accounts for individual-specific intercepts.When the number of individuals is large relative to the number of repeated measurements and the covariate dimension is high, we propose a dimension-reduction approach based on the least absolute shrinkage and selection operator (LASSO) penalty. Specifically, we extend adaptive LASSO quantile regression to accommodate longitudinal data. The proposed method retains oracle properties, including asymptotic normality and consistent variable selection. Monte Carlo simulations demonstrate that it performs best under moderate dimensionality, while also outperforming alternative methods in low-dimensional settings, though with smaller margins.The practical relevance of the approach is illustrated through two real-world applications: French electricity consumption and the Millennium Cohort Study. Using departmental-level data from France, we analyze non-residential electricity consumption to uncover patterns in energy demand. The log-transformed outcome remains markedly skewed, emphasizing the need for models capable of handling non-Gaussian distributions. Drawing on data from the Millennium Cohort Study, we examine factors associated with children's internalizing difficulties across different quantiles of the outcome distribution, identifying maternal mental health (Kessler scale) as the most influential predictor.</p
Simultaneous estimation of radiance and its sensitivities to radiative properties in a spherical-heterogeneous atmospheric radiative transfer model by Monte Carlo method: Application to Titan
No full textInternational audienceWe propose a control variates technique to reduce the variance of null-collision Monte Carlo algorithms used for solving the Radiative Transfer Equation (RTE) in highly heterogeneous media. The method complements the classical spatially partitioned overestimate approach by additionally recording the minimum absorption coefficient within each voxel during preprocessing. During path tracing, the attenuation due to this minimum absorption is evaluated analytically, while the residual part is handled by path-samplings. This analytical treatment significantly improves convergence particularly in strongly absorbing media such as the planetary atmospheres in infrared absorbing band. The mathematical equivalence between the original and control-variates estimators is demonstrated, and numerical applications for Earth's and Titan's atmospheres confirm the expected variance reduction.</div