Les conceptions de la médiatisation au début du XIXème siècle

Tout au long du XIXe siècle, la nécessité de construire un nouvel ordre social a suscité une réflexion sur la place à donner à la médiatisation dans cette reconstruction. Les auteurs examinent plus particulièrement comment, au cours de la première partie du siècle, la presse est apparue susceptible, en contribuant à la formation de l’opinion publique et à la récréation d’un lien social, de constituer désormais un instrument indispensable à l’exercice du pouvoir au sein d’une société marquée par une exigence croissante de publicité

Measuring global ocean heat content to estimate the earth energy imbalance

The energy radiated by the Earth toward space does not compensate the incoming radiation from the Sun leading to a small positive energy imbalance at the top of the atmosphere (0.4–1 Wm–2). This imbalance is coined Earth’s Energy Imbalance (EEI). It is mostly caused by anthropogenic greenhouse gas emissions and is driving the current warming of the planet. Precise monitoring of EEI is critical to assess the current status of climate change and the future evolution of climate. But the monitoring of EEI is challenging as EEI is two orders of magnitude smaller than the radiation fluxes in and out of the Earth system. Over 93% of the excess energy that is gained by the Earth in response to the positive EEI accumulates into the ocean in the form of heat. This accumulation of heat can be tracked with the ocean observing system such that today, the monitoring of Ocean Heat Content (OHC) and its long-term change provide the most efficient approach to estimate EEI. In this community paper we review the current four state-of-the-art methods to estimate global OHC changes and evaluate their relevance to derive EEI estimates on different time scales. These four methods make use of: (1) direct observations of in situ temperature; (2) satellite-based measurements of the ocean surface net heat fluxes; (3) satellite-based estimates of the thermal expansion of the ocean and (4) ocean reanalyses that assimilate observations from both satellite and in situ instruments. For each method we review the potential and the uncertainty of the method to estimate global OHC changes. We also analyze gaps in the current capability of each method and identify ways of progress for the future to fulfill the requirements of EEI monitoring. Achieving the observation of EEI with sufficient accuracy will depend on merging the remote sensing techniques with in situ measurements of key variables as an integral part of the Ocean Observing System

Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Le rejet de la délibération : du dogmatisme à l'élitisme

En 1828, Charles de Rémusat constate que la société française est désormais décrite très fréquemment comme « livrée à l'anarchie des opinions ». Il constate également que, si ce jugement a été formulé d'abord par les réactionnaires catholiques, qui « présentent la théocratie comme la seule digue qui puisse contenir le torrent », il a été repris par les saint-simoniens, qui « n'attendent le retour de l'ordre que d'un système social qui ferait de l'humanité un grand couvent polytechnique gouver..

Voies de signalisation de l’apoptose médiées par les sphingolipides

Divers sphingolipides sont aujourd’hui reconnus comme étant doués de propriétés biologiques et/ou agissant comme seconds messagers. Parmi eux, le céra- mide (ou N-acylsphingosine) et la sphingosine se comportent comme des médiateurs généralement proapoptotiques. Ainsi, le céramide relaie le signal cytotoxique d’un certain nombre d’agents de stress qui, soit, stimulent sa biosynthèse de novo, soit, activent l’hydrolyse de sphingomyéline par des sphingomyélinases. Par exemple, la génération précoce de céramide induite par le TNF est médiée par une sphingomyélinase neutre dont l’activité est sous la dépendance de la protéine adaptatrice FAN, contrôlant ainsi l’activation des caspases et le processus apoptotique. De plus, l’activité de cette sphingomyélinase neutre semble être modulée négativement par la cavéoline, un constituant essentiel de certains microdomaines membranaires. Par ailleurs, la sphingosine kinase est une enzyme-clé du métabolisme des sphingolipides car elle contrôle les taux intracellulaires de deux molécules aux effets antagonistes, la sphingosine, pro-apoptotique, et la sphingosine 1-phosphate, anti-apoptotique. Le métabolisme du céramide et de la sphingosine est donc considéré actuellement comme au cœur d'un ensemble de voies de signalisation régulant le devenir de la cellule

La médiatisation des problèmes publics

Médiatiser : le travail de journalistes et seulement de ceux-ci ? Quels enjeux pour les acteurs sociaux d’un processus où se joue l’une des formes de la publicisation ? Médiatiser : un travail de relation, de mise en réseaux aboutissant à du rédactionnel, étape ultime de la médiatisation ? Ou un travail de mise en circulation de discours dans des espaces multiples offerts à des lectures publiques ? Médiatiser : quels enjeux et quels points de vue pour les chercheurs ? Au travers de l’analyse des « problèmes publics », ce numéro d’Etudes de communication s’offre comme un espace de dialogue interdisciplinaire où Sciences de l’Information et de la Communication, Anthropologie, Science Politique, Histoire, Sciences du Langage conjuguent leurs perspectives pour mieux analyser ce qui est à l’œuvre dans l’acte de « médiatiser », ce qui se construit dans le processus social de « médiatisation ». Comité scientifique de ce numéro : Pierre Achard, Patrick Charaudeau, Bernard Miège, Pierre Moeglin, Jean Mouchon, Eric Neveu, Roger Odin, Michael Palmer, Jean-François Tétu, Yves Winkin. Comité de rédaction de ce numéro : Olivier Chantraine, Pierre Delcambre, Bernard Delforce, Elisabeth Fichez, Martine Hédoux, Bernard Leconte, François Poulle, Christine Revuz

Switched allotype expression in an immunoglobulin‐nonsecreting rabbit lymphoid cell line fused with rabbit gangliocytes

The Simian virus 40‐transformed rabbit spleen cell TRSC‐1 synthesizes intracellular whole IgG molecules of the a1b4 allotype. Two hypoxanthine‐guanine phosphoryl transferase‐deficient mutants were derived from this line. One of these, TRSC‐1‐8, was used in somatic cell fusion experiments together with gangliocytes from a rabbit immunized against β‐galactosidase. Out of nineteen hybrid clones surviving in selective medium, only one, L17, was shown to produce free γ chains which express the a2 allotype of the donor rabbit rather than the a1 marker of the parents TRSC‐1‐8 line. The inability to restore IgG secretion in hybrids suggests that dominant regulatory controls are exerted by the TRSC‐1 genome on Ig production. This supports the notion that the TRSC‐1 line originated from a splenocyte that had not reached the final plasmocyte differentiation stage at the time of viral transformation. Copyright © 1981 WILEY‐VCH Verlag GmbH & Co. KGaA, WeinheimSCOPUS: ar.jFLWNAinfo:eu-repo/semantics/publishe

Epoetin alfa facilitates presurgical autologous blood donation in non-anaemic patients scheduled for orthopaedic or cardiovascular surgery

Patients expected to need at least three units of blood for their elective cardiovascular or orthopaedic surgery, were allocated randomly to receive intravenous (i.v.) Epoetin alfa 600 IU kg-1 (n = 27), 300 IU kg-1 (n = 30) or placebo (n = 23), on days 1, 4 and 7. Provided haemoglobin ≤ 11 g dL-1, one unit of blood was collected on days 1, 4, 7, 11 and 14. Iron supplementation was given throughout the study. Surgery was scheduled between days 18 and 21. Significantly more patients treated with Epoetin alfa (100% for 600 IU kg-1; 97% for 300 IU kg-1) were able to donate ≤ 4 units of blood compared with placebo (78%) (P = 0.011 and P = 0.032). No significant differences were seen in total patient exposure to homologous blood 17.4%, 3.3% and 17.4%, respectively). Mean red cell volume donated (P = 0.005 for 600 IU kg-1; P = 0.158 for 300 IU kg-l both vs. placebo) and production (P < 0.001 and P = 0.012, respectively) were dose related. Twenty-four patients became iron deficient. No differences in the incidence of adverse events were seen between the groups.SCOPUS: ar.jinfo:eu-repo/semantics/publishe