131 research outputs found

    Entreprise et travail en Europe occidentale et aux États-Unis aux XIXe et XXe siùcles

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    Patrick Fridenson, directeur d’études Consommation, marchĂ©, rĂ©gulation (suite et fin) La troisiĂšme et derniĂšre annĂ©e de ce sĂ©minaire a Ă©tĂ© consacrĂ©e, d’une part, Ă  des enquĂȘtes sur des points jusque-lĂ  non encore abordĂ©s et, d’autre part, Ă  un Ă©largissement des perspectives. Dans un premier temps le sĂ©minaire a Ă©tudiĂ© les multiples changements des relations entre consommation et politique dans les annĂ©es 1950-1970 en prenant trois cas emblĂ©matiques. Le directeur d’études, en s’appuyant sur le..

    L'innovation technologique face au changement climatique : quelle est la position de la France ?

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    Cet article propose une analyse statistique du positionnement et de la performance de la France en matiĂšre de technologies de lutte contre le rĂ©chauffement climatique. La mĂ©thodologie s'appuie sur une base de donnĂ©es dĂ©crivant l'ensemble des dĂ©pĂŽts de brevets entre 1980 et 2008 dans 17 classes technologiques couvrant un large spectre de technologies liĂ©es au climat. Avec 5,2% des inventions brevetĂ©es en moyenne en 2008 dans les technologies Ă©tudiĂ©es, la France est en moyenne au 5Ăšme rang mondial dans un classement dominĂ© par les Etats-Unis, le Japon, la CorĂ©e du Sud et l'Allemagne. 20% des dĂ©pĂŽts de brevet en France proviennent du secteur public, contre 10% dans les autres pays industrialisĂ©s. Plus de la moitiĂ© des inventions "climat" françaises sont protĂ©gĂ©s dans des pays Ă©trangers, soit 1,5 fois plus que la moyenne mondiale. L'analyse par domaine technologique met en Ă©vidence un positionnement faible de la France dans les Ă©nergies renouvelables, dans lesquelles l'innovation est pourtant la plus dynamique au niveau mondial. En revanche, son positionnement est fort dans des secteurs comme le nuclĂ©aire (mĂȘme si elle n'arrive qu'au troisiĂšme rang derriĂšre le Japon et les Etats-Unis), la capture et sĂ©questration du carbone (CSC), l'isolation, le ciment, le chauffage, l'hydraulique et les vĂ©hicules Ă©lectriques et hybrides, oĂč elle tire parti de la prĂ©sence et du potentiel innovant des grandes firmes françaises d'envergure internationale (Air Liquide, Alstom, Areva, ElectricitĂ© de France, Lafarge, PSA Peugeot CitroĂ«n, Renault, Saint-Gobain, Schlumberger) et des organismes publics de recherche scientifique (CNRS, Commissariat Ă  l'Energie Atomique, Institut Français du PĂ©trole)

    Histoire sociale comparĂ©e de l’industrialisation

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    Alain Dewerpe, directeur d’études Les objets de l’industrie (1760-1960) Le sĂ©minaire, pour la troisiĂšme et derniĂšre annĂ©e, a Ă©tĂ© consacrĂ© aux objets dans l’histoire de l’industrialisation occidentale. Il a tentĂ© de faire l’inventaire raisonnĂ© – Ă  partir de dĂ©marches multiples (archĂ©ologie industrielle, histoire de la culture matĂ©rielle, sociologie des technosciences, Ă©conomie des conventions) – des objets de l’univers matĂ©riel de la production industrielle, d’analyser leurs interactions avec ..

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Search for invisible Higgs boson decays in vector boson fusion at s=13TeV with the ATLAS detector

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    We report a search for Higgs bosons that are produced via vector boson fusion and subsequently decay into invisible particles. The experimental signature is an energetic jet pair with invariant mass of O(1) TeVand O(100) GeVmissing transverse momentum. The analysis uses 36.1 fb(-1) of pp collision data at root s = 13 TeV recorded by the ATLAS detector at the LHC. In the signal region the 2252 observed events are consistent with the background estimation. Assuming a 125 GeV scalar particle with Standard Model cross sections, the upper limit on the branching fraction of the Higgs boson decay into invisible particles is 0.37 at 95% confidence level where 0.28 was expected. This limit is interpreted in Higgs portal models to set bounds on the wimp-nucleon scattering cross section. We also consider invisible decays of additional scalar bosons with masses up to 3 TeV for which the upper limits on the cross section times branching fraction are in the range of 0.3-1.7 pb. (C) 2019 The Author(s). Published by Elsevier B.V

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

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    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/)

    Combination of searches for WW, WZ, and ZZ resonances in pp collisions at root s=8 TeV with the ATLAS detector

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    The ATLAS experiment at the CERN Large Hadron Collider has performed searches for new, heavy bosons decaying to WW, WZ and ZZ final states in multiple decay channels using 20.3 fb-1 of pp collision data at s=8 TeV. In the current study, the results of these searches are combined to provide a more stringent test of models predicting heavy resonances with couplings to vector bosons. Direct searches for a charged diboson resonance decaying to WZ in the ℓΜℓ'ℓ' (ℓ=ÎŒ, e), ℓℓqq-, â„“Îœqq- and fully hadronic final states are combined and upper limits on the rate of production times branching ratio to the WZ bosons are compared with predictions of an extended gauge model with a heavy W' boson. In addition, direct searches for a neutral diboson resonance decaying to WW and ZZ in the ℓℓqq-, â„“Îœqq-, and fully hadronic final states are combined and upper limits on the rate of production times branching ratio to the WW and ZZ bosons are compared with predictions for a heavy, spin-2 graviton in an extended Randall-Sundrum model where the Standard Model fields are allowed to propagate in the bulk of the extra dimension

    Measurement of differential cross sections of isolated-photon plus heavy-flavour jet production in pp collisions at √s=8 TeV using the ATLAS detector

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    This Letter presents the measurement of differential cross sections of isolated prompt photons produced in association with a b-jet or a c-jet. These final states provide sensitivity to the heavy-flavour content of the proton and aspects related to the modelling of heavy-flavour quarks in perturbative QCD. The measurement uses proton–proton collision data at a centre-of-mass energy of 8 TeV recorded by the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of up to 20.2 fb−1. The differential cross sections are measured for each jet flavour with respect to the transverse energy of the leading photon in two photon pseudorapidity regions: |ηγ | < 1.37 and 1.56 < |ηγ | < 2.37. The measurement covers photon transverse energies 25 < EÎł T < 400 GeV and 25 < EÎł T < 350 GeV respectively for the two |ηγ | regions. For each jet flavour, the ratio of the cross sections in the two |ηγ | regions is also measured. The measurement is corrected for detector effects and compared to leading-order and nextto-leading-order perturbative QCD calculations, based on various treatments and assumptions about the heavy-flavour content of the proton. Overall, the predictions agree well with the measurement, but some deviations are observed at high photon transverse energies. The total uncertainty in the measurement ranges between 13% and 66%, while the central Îł + b measurement exhibits the smallest uncertainty, ranging from 13% to 27%, which is comparable to the precision of the theoretical predictions
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