109 research outputs found
LâIntelligence Collective dans la Conception et le DĂ©ploiement dâune UnitĂ© dâEnseignement Transversale et Interdisciplinaire Ă Grande Ăchelle : lâUE CATI
LâUnitĂ© dâEnseignement (UE) CATI est basĂ©e sur lâapprentissage par projets, la transversalitĂ© et lâinterdisciplinaritĂ© de sa conception jusquâĂ sa valorisation. ExpĂ©rimentĂ©es pour la premiĂšre2fois en 2020-2021 pour les 1086 Ă©tudiants de 1Êłá” annĂ©e de licence inscrits au sein de lâinstitut sciences et techniques de CY Cergy Paris UniversitĂ© (CY), la construction et la rĂ©alisation en apprentissage par projet dâune UE interdisciplinaire de cette envergure ont Ă©tĂ© rendues possibles par lâimplication de plusieurs acteurs, en mobilisant les principes de lâintelligence collective.Dans cet article, nous indiquerons comment lâintĂ©gration des principes de lâintelligence collective Ă toutes les Ă©tapes a permis dâengager et de mettre en mouvement ces diffĂ©rents acteurs : la conception de lâUE par 15 enseignants issus de 8 dĂ©partements disciplinaires, sa mise en oeuvre/animation par 44 Ă©tudiants-tuteurs, eux-mĂȘmes accompagnĂ©s par deux services distincts de lâuniversitĂ©, a permis au millier dâĂ©tudiants de 1Êłá” annĂ©e organisĂ©s en 143 groupes autonomes, de travailler en apprentissage par projet, de produire dans les dĂ©lais imposĂ©s des livrables ancrĂ©s dans des problĂ©matiques sociĂ©tales et territoriales
The Origin of Phenotypic Heterogeneity in a Clonal Cell Population In Vitro
BACKGROUND: The spontaneous emergence of phenotypic heterogeneity in clonal populations of mammalian cells in vitro is a rule rather than an exception. We consider two simple, mutually non-exclusive models that explain the generation of diverse cell types in a homogeneous population. In the first model, the phenotypic switch is the consequence of extrinsic factors. Initially identical cells may become different because they encounter different local environments that induce adaptive responses. According to the second model, the phenotypic switch is intrinsic to the cells that may occur even in homogeneous environments. PRINCIPAL FINDINGS: We have investigated the âextrinsicâ and the âintrinsicâ mechanisms using computer simulations and experimentation. First, we simulated in silico the emergence of two cell types in a clonal cell population using a multiagent model. Both mechanisms produced stable phenotypic heterogeneity, but the distribution of the cell types was different. The âintrinsicâ model predicted an even distribution of the rare phenotype cells, while in the âextrinsicâ model these cells formed small clusters. The key predictions of the two models were confronted with the results obtained experimentally using a myogenic cell line. CONCLUSIONS: The observations emphasize the importance of the âecologicalâ context and suggest that, consistently with the âextrinsicâ model, local stochastic interactions between phenotypically identical cells play a key role in the initiation of phenotypic switch. Nevertheless, the âintrinsicâ model also shows some other aspects of reality: The phenotypic switch is not triggered exclusively by the local environmental variations, but also depends to some extent on the phenotypic intrinsic robustness of the cells
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 ââGreenâ 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. Instrumentsâ development and satellite missionsâ 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 25âŻyears 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 âGreenâ 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. Instrumentsâ development and satellite missionsâ 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
Les crustacés de l'Oxfordien supérieur de Cricqueboeuf (Normandie, France)
International audienceLa faune du Jurassique supĂ©rieur (Oxfordien supĂ©rieur) de Cricqueboeuf (Normandie, France) est remarquable par ses crustacĂ©s fossilisĂ©s en trois dimensions dans des nodules carbonatĂ©s et phosphatĂ©s, certains conservant mĂȘme leurs yeux avec le rĂ©seau d'ommatidies. La faune (Crustacea, Decapoda) comprend quatre espĂšces attribuĂ©es aux langoustes Mecochiridae Van Straelen, 1925 (Meyeria n. sp.), Glypheidae Winkler, 1881 (Glypheopsis trouvillensis Charbonnier, Garassino, Schweigert & Simpson, 2013) et Erymidae Van Straelen, 1925 (Eryma ventrosum [Meyer, 1835], Enoploclytia sp.). Une analyse quantitative basĂ©e sur 191 spĂ©cimens montre que la faune Ă©tait dominĂ©e par Eryma ventrosum (46,6 % des spĂ©cimens) et Meyeria n. sp. (40,3 %), la rendant unique dans le registre fossilifĂšre des assemblages de crustacĂ©s du Jurassique. Meyeria n. sp. est l'une des plus anciennes occurrences du genre Meyeria M'Coy, 1849 et son abondance Ă Cricqueboeuf est remarquable.Le palĂ©oenvironnement est interprĂ©tĂ© comme correspondant Ă des vasiĂšres subtidales, oĂč le substrat mou Ă©tait favorable Ă la colonisation et au creusement de terriers par les glyphĂ©ides, mĂ©cochirides et Ă©rymides. La plupart des spĂ©cimens auraient Ă©tĂ© conservĂ©s directement Ă l'intĂ©rieur de leur propre terrier, comblĂ© par le remaniement du fond boueux lors d'apports dĂ©tritiques
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