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14C dating of tsunami deposits in arid environments: How challenging can it be? The example of La Graciosa, Canary Islands
No full textco-auteur étrangerInternational audienceC dating of tsunami deposits in arid environments is often challenging, especially when there is no organic material available. The marine bioclasts found in the tsunami deposits thus become the main dating possibility. Apart from the reservoir effect, the main source of uncertainty is the age difference between the shells and the tsunami that transported them.Taking as an example a tsunami deposit on the island of La Graciosa (Canary Islands), we demonstrate that the marine shells (Patella) come from different sources, with 14 C ages ranging from >45 kBP to 200 BP, the main source being an ancient marine terrace probably of MIS5e age. In addition, we propose a landslide source for this tsunami, the scar of which can be observed on the Famara cliff to the northeast of Lanzarote, just opposite the tsunami deposit outcrops at La Graciosa. In addition to the methodological aspects of shell dating, this study also serves as a reminder that local tsunamis generated by coastal cliff collapses are not a hazard to be neglected.</p
Les réformes contemporaines de l’institution judiciaire face à la crise de la justice
No full textInternational audienc
Flux map on tall towers: a study over heterogeneous landscapes
No full textARPHA Conference Abstracts 8: e150592International audienceMonitoring fluxes of greenhouse gases is crucial to attribute sources and sinks. With advancements in satellite technology offering resolutions smaller than a tower's footprint, we can now have spatially-explicit estimations at the meter scale, a comparable resolution to in-situ observations. This study explores the potential of assimilating tall tower eddy covariance fluxes to calibrate a surface model of CO 2 exchange over a heterogeneous landscape. We present a bayesian inversion strategy which compares an estimated flux supposedly measured by the tower, calculated based on a priori flux map and a footprint model, and the observed flux. Two sites (Saclay and P2OA) are evaluated both consisting of a mix of agricultural, forest and urban patches. The heterogeneous landscape provides an ideal setting to assess the method's ability to distinguish and quantify greenhouse gas flux contributions from different land types
Leveraging interaction between memory footprint and parallelism degree for efficient GPU portings
No full textInternational audiencePorting large HPC applications entirely on a Graphics Processing Unit (GPU) can be challenging. Some code portions are indeed unsuitable for GPU porting. Therefore, selecting the most profitable code parts for GPU porting is crucial. Many profiling tools address this issue, but their overhead is non-negligible for large HPC test cases. Moreover, the extracted code parts might not be the best candidates for any input set size. We present an approach that extrapolates the behavior of pre-selected code parts from different input set size runs on a target GPU. This enables developers to evaluate the application's parallelism potential and memory footprint prior to GPU porting. We applied our approach to several HPC mini-applications and evaluated the extrapolations through a comparison to the existing GPU versions, as ground truth, on different vendors' GPUs. Our results provide input set sizes of magnitude leading to GPU memory saturation and recommend which pre-selected code parts should be further studied for GPU porting
Evaluation of O<sub>3</sub>, H<sub>2</sub>O, CO, and NO<sub><i>y</i></sub> climatologies simulated by four global models in the upper troposphere–lower stratosphere with IAGOS measurements
No full textInternational audienceAssessing global models in the upper troposphere (UT) and in the lowermost stratosphere (LS) is an important step toward a better understanding of the chemical composition near the tropopause. For this purpose, the current study focuses on an evaluation of long-term simulations from four chemistry-climate/transport models, based on In-service Aircraft for a Global Observing System (IAGOS) measurements. Most simulations span the period from 1995 to 2017 and follow a common protocol among models. The assessment focuses on climatological averages of ozone (O 3 ), water vapour (H 2 O), carbon monoxide (CO), and reactive nitrogen (NO y ). In the extra-tropics, the models reproduce the seasonality of O 3 , H 2 O, and NO y in both the UT and LS, but none of them reproduce the CO springtime maximum in the UT. Tropospheric tracers (CO and H 2 O) tend to be underestimated in the UT, consistently with an overestimation of cross-tropopause exchanges. Most models systematically overestimate ozone in the UT, and the background of nitrogen oxides (NO x ) appears to be the main contributor to ozone variability across the models. The partitioning between NO y species changes drastically across the models and acts as a source of uncertainty in the NO x mixing ratio and on the impact of these species on atmospheric composition. However, we highlight some well-reproduced geographical variations, such as the Intertropical Convergence Zone (ITCZ) seasonal shifts above Africa and the correlation of extratropical ozone (H 2 O) in the LS (UT) with the observations. These features are encouraging with respect to the simulated dynamics in both layers. The current study confirms the importance of separating the UT and the LS with a dynamical tracer for the evaluation of model results and for model intercomparisons.</div
Visualization of Respiratory Syncytial Virus RNA Synthesis Sites by Ethynyl Uridine Labeling
No full textInternational audienceModified cell-permeable nucleosides such as 5-bromouridine 5′-triphosphate (BrUTP) or 5-ethynyluridine (5-EU), together with the powerful click chemistry, have been widely used to specifically label newly synthetized RNA in cells and tissues in a simple two-step approach. The use of cellular transcription inhibitors has established metabolic RNA labeling as an optimal approach for the precise visualization of viral RNA transcripts and the microscopic analysis of their distribution in infected cells. The labeling of nascent viral RNA of respiratory syncytial virus (RSV) and other Mononegavirales (MNV) (e.g., rabies virus (RABV), Ebola virus (EBOV), or human metapneumovirus (HMPV)) demonstrated the presence of newly synthesized viral RNAs in virally induced cytoplasmic inclusions called inclusion bodies (IBs). This was the crucial result to confirm that viral RNA synthesis occurs in these IBs, which could thus be renamed viral factories. Here, we describe a method for the unbiased detection of newly synthetized viral RNA in RSV-infected cells via metabolic labeling with 5-EU and subsequent detection using highly specific alkyne-azide “click” chemistry
Risk of over-diagnosis in iconodiagnosis: the example of Rachel Furtado's portrait
No full textInternational audienceThe practice of iconodiagnostics requires careful observation, as well as knowledge of the biographic details of the subject and the artist's style, to avoid making excessive diagnoses. We have analyzed the portraits of Rachel Furtado and her husband from the 19th century displayed at the Museum of Art and History of Judaism in Paris. A thorough examination and knowledge of their way of life allows us to distinguish pigment disorders from the painter's stylistic effects and avoid diagnostic pitfalls
Les syndromes d'Ehlers-Danlos : diagnostic et parcours de soins de ces maladies complexes et multisystémiques
No full textInternational audienceEhlers-Danlos syndromes (EDS) are a heterogeneous group of rare and inherited connective tissue disorders characterized by the following clinical triad: joint hypermobility, skin hyperelasticity and tissue fragility. Thirteen subtypes of EDS were described in 2017 by an international consortium: there are 12 subtypes with an identified genetic etiology, and the most frequent hypermobile EDS of which the molecular basis remains unknown. EDS are complex and multisystemic pathologies, with a wide clinical and genetical heterogeneity. Diagnosing EDS is a tough task, and it requires to apply a rigorous method to spot clinical red flags and eliminate differential diagnoses. There is no specific treatment for non-vascular EDS to date, so the care management is symptomatic, multidisciplinary and personalized. This document in the "carrefour des spécialités" section presents the diagnosis pathway and the care management for both vascular and non-vascular EDS.Les syndromes d’Ehlers-Danlos (SED) sont un groupe hétérogène de maladies rares et héréditaires du tissu conjonctif caractérisées par la triade clinique : hypermobilité articulaire, hyperélasticité cutanée et fragilité tissulaire. On distingue 13 types de SED décrits par un consortium international en 2017, dont 12 ont une cause génétique identifiée, et le SED hypermobile, le plus fréquent, dont les bases moléculaires demeurent inconnues. Ce sont des pathologies complexes, multisystémiques, présentant une grande hétérogénéité clinique et génétique. Leur diagnostic est difficile et requiert une méthode rigoureuse pour repérer les points d’appel cliniques et écarter les nombreux diagnostics différentiels. Il n’existe à ce jour pas de traitement spécifique pour les SED non vasculaires, dont la prise en charge est symptomatique, multidisciplinaire et personnalisée. Ce document au carrefour des spécialités traite de la démarche diagnostique et de la prise en charge pour les SED vasculaires et non vasculaires
Editorial commitment to trust and integrity in science: Implications for pain and anesthesiology research
No full textInternational audienceNo abstract availabl