Réalisation d’un Contrat d’Etudes Prospectives des secteurs du transport: Rapport final

Le CEP a pour objectif de réaliser un état des lieux du secteur, de conduire une analyse prospective qualitative et quantitative de l’évolution des métiers et des besoins de compétences du transport et de préconiser un plan d’actions pour les transports routiers, maritimes et fluviaux. A l’issue des travaux d’étude, le rapport final a été remis aux membres du Comité de pilotage (Ministère de l’emploi - DGEFP, Représentants des branches des transports, l’OPCA Transports et Services, Pôle Emploi, Ministère de l’écologie et du développement durable, des transport et du logement)

Effects of forcing differences and initial conditions on inter-model agreement in the VolMIP volc-pinatubo-full experiment

International audienceThis paper provides initial results from a multi-model ensemble analysis based on the volc-pinatubo-full experiment performed within the Model Intercomparison Project on the climatic response to volcanic forcing (VolMIP) as part of the sixth phase of the Coupled Model Intercomparison Project (CMIP6). The volc-pinatubo-full experiment is based on ensemble of volcanic forcing-only climate simulations with the same volcanic aerosol dataset across the participating models (the 1991-1993 Pinatubo period from the CMIP6-GloSSAC dataset). The simulations are conducted within an idealized experimental design where initial states are sampled consistently across models from the CMIP6-piControl simulation providing unperturbed pre-industrial background conditions. The multi-model ensemble includes output from an initial set of six participating Earth system models (CanESM5, GISS-E2.1-G, IPSL-CM6A-LR, MIROC-E2SL, MPI-ESM1.2-LR and UKESM1).The results show overall good agreement between the different models on the global and hemispheric scale concerning the surface climate responses, thus demonstrating the overall effectiveness of VolMIP’s experimental design. However, small yet significant inter-model discrepancies are found in radiative fluxes especially in the tropics, that preliminary analyses link with minor differences in forcing implementation, model physics, notably aerosol-radiation interactions, the simulation and sampling of El Niño-Southern Oscillation (ENSO) and, possibly, the simulation of climate feedbacks operating in the tropics. We discuss the volc-pinatubo-full protocol and highlight the advantages of volcanic forcing experiments defined within a carefully designed protocol with respect to emerging modeling approaches based on large ensemble transient simulations. We identify how the VolMIP strategy could be improved in future phases of the initiative to ensure a cleaner sampling protocolwith greater focus on the evolving state of ENSO in the pre-eruption period

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Adiponectin: a new adipocytokine

peer reviewedAdipose tissue is not simply a store of excess energy, but also secretes a variety of proteins into circulating blood that influence systemic metabolism. These include tumor necrosis factor (TNF-alpha), plasminogen activator inhibitor type 1 (PAI-1), leptin, resistine and adiponectin. These are collectively known as adipocytokines. Adiponectin (also referred to as AdipoQ, Acrp 30, apM1 or GBP28) is a novel adipose-specific protein. A recent genome study mapped a susceptibility locus for type 2 diabetes and the metabolic syndrome on chromosome 3q27, where the adiponectin gene is located. Adiponectin is a peculiar adipocytokine because in contrast to the markedly increased levels of many others, as leptin or TNF-alpha, its level is reduced in obesity and type 2 diabetes. The administration of thiazolidinediones, which are synthetic PPARs-gamma ligands, significantly increases the plasma adiponectin concentrations, an effect that could improve insulin sensitivity. Thus, the administration of adiponectin may provide a novel treatment modality for insulin resistance and type 2 diabetes

Cocaïne (portrait d'une drogue)

LILLE2-BU Santé-Recherche (593502101) / SudocSudocFranceF

The influence of volcanic eruptions on circulation regimes over the North Atlantic and their impact on European climate

International audienceLarge volcanic eruptions influence climate on both annual and decadal time scales due todynamical interactions of different climate components in the Earth's system. It is well established that the North Atlantic Oscillation (NAO) tends to shift towards its positive phase during the winter season in the first 1–2 years after large tropical volcanic eruptions, causing warming over Europe. However, other North Atlantic circulation regimes such as Atlantic Ridge or zonal regime have received less attention. This study explores the volcanic fingerprint in terms of patterns and mechanisms on the North Atlantic atmospheric circulation in IPSL-CM6A-LR model simulations for tropical eruptions of the last millennium using dedicated sensitivity experiments and observatio

Spatiotemporal Variability of the South Pacific Convergence Zone Fresh Pool Eastern Front from Coral-Derived Surface Salinity Data

International audienceDirect observations indicate a southeastward expansion of the South Pacific convergence zone (SPCZ) fresh pool and a freshening trend since the 1970s. Understanding decadal and longer-term variability of the SPCZ fresh pool and of the salinity front located at its southeastern margin has been limited by the scarcity of instrumental sea surface salinity (SSS) measurements. This study uses coral δ18O as a proxy for SSS to extend the salinity record back to the 1880s, from three different locations across the SSS front: Fiji, Tonga, and Rarotonga (FTR region). High percentages of observed SSS variance are explained by multicoral δ18O mean composite at each site. At the interannual time scale, the salinity front displacement over the last 200 years follows the El Niño–Southern Oscillation (ENSO) index. The different El Niño flavors are observable in the amplitude of the salinity front interannual displacement. However, no significant changes in either the frequency or the amplitude of its displacements were observed. At longer time scales, the timing and magnitude of the freshening trend vary among sites. The earliest freshening onset of about −0.06 psu decade−1 is detected in Fiji (around 1865), then Rarotonga (around 1939), and Tonga (around 1982). The role of atmospheric freshwater fluxes on SSS variability is evaluated by comparing coral SSS to historical precipitation data. The results suggest that, despite the known influence of the interdecadal Pacific oscillation (IPO) negative phases on increasing atmospheric freshwater fluxes and lowering SSS in the FTR region, ocean dynamics has a dominant influence at decadal time scale and in the onset of freshening trends

Influence of external forcings on the hydroclimate conditions in the Europe-Mediterranean Region over the Common Era : a model/data approach

International audienceThe climate system has been largely influenced by emerging anthropogenic forcing effects during the last decades of the historical period. Hence, the historical simulations may not be the most appropriate ones to constrain the internal climate variability at such long time scales. The last 2000 years provide a promising time frame constrained by climate reconstructions to explore the interactions between external forcings and the internal dynamics of climate. The Common Era is indeed relatively long and forcing are reasonably well reconstructed and physical processes modelled. In this contribution, we use IPSL-CM6A-LR model simulations covering the last 1500 years (500AD to Present Day) and available paleo-proxy reconstructions to study the influence of the internal variability and external forcing on climate variability in the North Atlantic at decadal-to-multi-decadal time scales and the impacts on the hydro-climate conditions evolution over Europe-Mediterranean sector

Contributions of Internal Variability and External Forcing to the Recent Trends in the Southeastern Pacific and Peru-Chile Upwelling System

International audienceIn a warming world context, sea surface temperature (SST) off central-south Peru, northern Chile, and farther offshore increases at a slower rate than the global average since several decades (i.e., cools, relative to the global average). This tendency is synchronous with an interdecadal Pacific oscillation (IPO) negative trend since ~1980, which has a cooling signature in the southeastern Pacific. Here, we use a large ensemble of historical coupled model simulations to investigate the relative roles of internal variability (and in particular the IPO) and external forcing in driving this relative regional cooling, and the associated mechanisms. The ensemble mean reproduces the relative cooling, in response to an externally forced southerly wind anomaly, which strengthens the upwelling off Chile in recent decades. This southerly wind anomaly results from the poleward expansion of the Southern Hemisphere Hadley cell. Attribution experiments reveal that this poleward expansion and the resulting enhanced upwelling mostly occur in response to increasing greenhouse gases and stratospheric ozone depletion since ~1980. An oceanic heat budget confirms that the wind-forced upwelling enhancement dominates the relative cooling near the coast. In contrast, a wind-forced deepening of the mixed layer drives the offshore cooling. While internal variability contributes to the spread of tendencies, the ensemble-mean relative cooling in the southeastern Pacific is consistent with observations and occurs irrespectively of the IPO phase, hence, indicating the preeminent role of external forcing