Le coyote dans l’iconographie mésoaméricaine, de 200 ap. J.-C. jusqu’à la Conquête

The coyote in Central American iconography (from 250 A. D. to the conquest). The coyote, an animal specific to the American continent, drew the attention of Indian people from prehistoric times and is still present to-day in the symbolic world of some North American tribes. The artistic production of Central American culture, from the Classical Period (200-900 A.D.) is an excellent evidence of this particular interest : indeed, the coyote is present on a great variety of artefacts : wall paintings, sculpture, pottery and feather works. The violent image developed around the animal is surprising, since the coyote is far less aggressive than other animals of prev : jaguar, wolf or puma. Realistic figuration seems to refer to certain norms, with slight differences according to the cultures. Since the Teotihuacan period (200-750 A.D.), the animal seems to he symbolically related to fertility and war.</jats:p

Le coyote dans l’iconographie mésoaméricaine, de 200 ap. J.-C. jusqu’à la Conquête

The coyote in Central American iconography (from 250 A. D. to the conquest). The coyote, an animal specific to the American continent, drew the attention of Indian people from prehistoric times and is still present to-day in the symbolic world of some North American tribes. The artistic production of Central American culture, from the Classical Period (200-900 A.D.) is an excellent evidence of this particular interest : indeed, the coyote is present on a great variety of artefacts : wall paintings, sculpture, pottery and feather works. The violent image developed around the animal is surprising, since the coyote is far less aggressive than other animals of prev : jaguar, wolf or puma. Realistic figuration seems to refer to certain norms, with slight differences according to the cultures. Since the Teotihuacan period (200-750 A.D.), the animal seems to he symbolically related to fertility and war.Allain Ariane. Le coyote dans l’iconographie mésoaméricaine, de 200 ap. J.-C. jusqu’à la Conquête. In: Histoire de l'art, N°49, 2001. Animalia. pp. 39-49

La sculpture à Teotihuacan

International audienc

La sculpture dans la civilisation de Teotihuacan

Teotihuacan occupe, à l'époque classique, une position essentielle dans le Bassin de Mexico et au-delà. Or, en dépit des très nombreuses recherches dont le site a fait l'objet depuis la fin du XIXe siècle, il n'existe aucune étude systématique du matériel sculpté mis au jour dans cette métropole. Le présent travail a consisté d'abord à établir un corpus aussi exhaustif que possible de la sculpture produite à Teotihuacan. Les pièces inférieures à 25 cm de hauteur, les masques et les objets sculptés en obsidienne en ont été toutefois exclus, car ils représentent des catégories d'art lapidaire de forme et de fonction apparemment distinctes des autres sculptures. Le corpus constitué comporte 322 fiches qui correspondent à un total de 866 sculptures. C'est cet ensemble d'œuvres qui a été soumis à des analyses iconographique, stylistique et de distribution spatiale. De la recherche effectuée il ressort que la sculpture a été relativement peu abondante à Teotihuacan, en particulier par rapport à la peinture murale. Les images zoomorphes et les représentations à caractère symbolique occupent une place importante ; les figures anthropomorphes sont également présentes, mais il s'agit d'image dépersonnalisée. En réalité, il est possible de distinguer deux grandes familles de sculptures : les unes ont décoré des édifices publics, tandis que les autres se trouvent plutôt dans des contextes résidentiels. Il existe cependant au moins une classe d'objet (les représentations du Vieux Dieu) que l'on rencontre aussi bien dans la zone cérémonielle que dans les secteurs d'habitation. L'analyse des données a finalement permis de déceler l'existence d'un changement sculptural, qui interviendrait aux alentours de 200 apr. J-C. ; ce changement se traduit autant dans les motifs représentés que dans le style des sculptures.PARIS1-BU Pierre Mendès-France (751132102) / SudocSudocFranceF

Internal tides in the Solomon Sea in contrasted ENSO conditions

Abstract. Intense equatorward western boundary currents transit the Solomon Sea, where active mesoscale structures exist with energetic internal tides. In this marginal sea, the mixing induced by these features can play a role in the observed water mass transformation. The objective of this paper is to document the M2 internal tides in the Solomon Sea and their impacts on the circulation and water masses, based on two regional simulations with and without tides. Since the Solomon Sea is under the influence of ENSO, the characteristics of the internal tides are also analyzed for two contrasted conditions: the January–March 1998 El Niño and the April–June 1999 La Niña. The generation, propagation, and dissipation of the internal tides are sensitive to changes in stratification and mesoscale activity, and these differ between these contrasted El Niño and La Niña case studies. Mode 1 is the dominant vertical mode to propagate baroclinic tidal energy within the Solomon Sea, but mode 2 becomes more energetic during the El Niño period when the stratification is closer to the surface. The La Niña period with a higher level of mesoscale activity exhibits more incoherent internal tides. These results illustrate the complexity of predicting internal tides in marginal seas in order to clearly observe meso- and submesoscale signatures from altimetric missions, including the future Surface Water Ocean Topography (SWOT) mission. Diapycnal mixing induced by tides contributes to a stronger erosion of the salinity maximum of the upper thermocline water and to cooling of the surface temperature interacting with the atmosphere. Such effects are particularly visible in quieter regions, where particles may experience the tidal effects over a longer time. However, when averaged over the Solomon Sea, the tidal effect on water mass transformation is an order of magnitude less than that observed at the entrance and exits of the Solomon Sea. These localized sites appear crucial for diapycnal mixing, since most of the baroclinic tidal energy is generated and dissipated locally here, and the different currents entering/exiting the Solomon Sea merge and mix. Finally, the extreme ENSO condition case studies suggest the strong role of local circulation changes, as well as stratification changes, in modifying the internal tides. </jats:p

Allosteric pathway identification through network analysis: from molecular dynamics simulations to interactive 2D and 3D graphs

Allostery is a universal phenomenon that couples the information induced by a local perturbation (effector) in a protein to spatially distant regulated sites. Such an event can be described in terms of a large scale transmission of information (communication) through a dynamic coupling between structurally rigid (minimally frustrated) and plastic (locally frustrated) clusters of residues. To elaborate a rational description of allosteric coupling, we propose an original approach – MOdular NETwork Analysis (MONETA) – based on the analysis of inter-residue dynamical correlations to localize the propagation of both structural and dynamical effects of a perturbation throughout a protein structure. MONETA uses inter-residue cross-correlations and commute times computed from molecular dynamics simulations and a topological description of a protein to build a modular network representation composed of clusters of residues (dynamic segments) linked together by chains of residues (communication pathways). MONETA provides a brand new direct and simple visualization of protein allosteric communication. A GEPHI module implemented in the MONETA package allows the generation of 2D graphs of the communication network. An interactive PyMOL plugin permits drawing of the communication pathways between chosen protein fragments or residues on a 3D representation. MONETA is a powerful tool for on-the-fly display of communication networks in proteins. We applied MONETA for the analysis of communication pathways (i) between the main regulatory fragments of receptors tyrosine kinases (RTKs), KIT and CSF-1R, in the native and mutated states and (ii) in proteins STAT5 (STAT5a and STAT5b) in the phosphorylated and the unphosphorylated forms. The description of the physical support for allosteric coupling by MONETA allowed a comparison of the mechanisms of (a) constitutive activation induced by equivalent mutations in two RTKs and (b) allosteric regulation in the activated and non-activated STAT5 proteins. Our theoretical prediction based on results obtained with MONETA was validated for KIT by in vitro experiments. MONETA is a versatile analytical and visualization tool entirely devoted to the understanding of the functioning/malfunctioning of allosteric regulation in proteins – a crucial basis to guide the discovery of next-generation allosteric drugs.</p

Internal tides in the Solomon Sea in contrasted ENSO conditions

International audienceIntense equatorward western boundary currents transit the Solomon Sea, where active mesoscale structures exist with energetic internal tides. In this marginal sea, the mixing induced by these features can play a role in the observed water mass transformation. The objective of this paper is to document the M2 internal tides in the Solomon Sea and their impacts on the circulation and water masses, based on two regional simulations with and without tides. Since the Solomon Sea is under the influence of ENSO, the characteristics of the internal tides are also analyzed for two contrasted conditions: the January-March 1998 El Niño and the April-June 1999 La Niña. The generation, propagation, and dissipation of the internal tides are sensitive to changes in stratification and mesoscale activity, and these differ between these contrasted El Niño and La Niña case studies. Mode 1 is the dominant vertical mode to propagate baroclinic tidal energy within the Solomon Sea, but mode 2 becomes more energetic during the El Niño period when the stratification is closer to the surface. The La Niña period with a higher level of mesoscale activity exhibits more incoherent internal tides. These results illustrate the complexity of predicting internal tides in marginal seas in order to clearly observe meso- and submesoscale signatures from altimetric missions, including the future Surface Water Ocean Topography (SWOT) mission. Diapycnal mixing induced by tides contributes to a stronger erosion of the salinity maximum of the upper thermocline water and to cooling of the surface temperature interacting with the atmosphere. Such effects are particularly visible in quieter regions, where particles may experience the tidal effects over a longer time. However, when averaged over the Solomon Sea, the tidal effect on water mass transformation is an order of magnitude less than that observed at the entrance and exits of the Solomon Sea. These localized sites appear crucial for diapycnal mixing, since most of the baroclinic tidal energy is generated and dissipated locally here, and the different currents entering/exiting the Solomon Sea merge and mix. Finally, the extreme ENSO condition case studies suggest the strong role of local circulation changes, as well as stratification changes, in modifying the internal tides

Internal tides in the Solomon Sea in contrasted ENSO conditions

Abstract. The Solomon Sea is a place of intense Low Latitudes Western Boundary current transiting to the equator where mesoscale activity is superimposed on internal tides. In this marginal sea, the cumulated effects of these dynamical constraints result in water mass transformation as observed by in situ observations. The objective of this paper is to document the M2 internal tides in the Solomon Sea and their impacts based on two regional simulations with and without tides. Because the Solomon Sea is under the influence of ENSO, the characteristics of the internal tides are analyzed for two contrasted ENSO conditions: the 1997–1998 El Niño and the 1999 La Niña. The generation, propagation and dissipation of the internal tides are sensitive to changes in stratification and mesoscale activity between El Niño and La Niña. Mode 1 is the dominant mode to propagate baroclinic tidal energy within the Solomon Sea, but the El Niño conditions, with stratification closer to the surface, are favorable for the propagation of mode 2. The la Niña case with a high level of mesoscale activity favors the appearance of incoherent internal tides. These results illustrate the complexity in predicting internal tides in order to access meso and submesoscale signatures from altimetric missions, including the future SWOT mission. Diapycnal mixing induced by the internal tides is efficient in eroding the salinity maximum of the upper thermocline water, and in cooling the surface temperature interacting with the atmosphere. Such effects are particularly visible far from the strong currents, where particles may experience the tidal effects during a longer time. Nevertheless, the impacts are different when considering particular ENSO conditions. The interaction of internal tides with the surface mesoscale activity reduces surface cooling during El Niño 1998, but increases surface warming during La Niña 1999, with possible impacts on regional air sea interaction. </jats:p

Explicit modelling of external and internal tidal waves in the global 1/12&amp;#176; NEMO ocean model

&amp;lt;p&amp;gt;Ocean tides play a major role in ocean mixing, and setting up water properties, both in the deep and the shallow ocean. Whether parameterized or explicitly simulated, tides can not be ignored in modern ocean prediction models. Representing them explicitly, the approach followed here to prepare the upcoming CMEMS (Copernicus Marine Environment Monitoring Service) global prediction system, allows for the generation of a large quantity of internal waves propagating at great distances. This is a useful information for future high resolution wide swath altimetry missions but also for forcing regional systems, enabling remotely generated internal waves to enter the user domain, providing in some places an important part of the high frequency&amp;lt;br&amp;gt;energy.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;In the present work, we review numerical aspects in the NEMO ocean model influencing the explicit representation of both external and internal tidal waves in a global 1/12&amp;amp;#176; configuration. The numerical core of NEMO has indeed largely evolved recently to simulate tides, by now including the lunisolar tidal potential, Self Attraction and Loading effects, a split-explicit barotropic solver but also Lagrangian vertical coordinates to limit the spurious numerical diffusion. We report here the effect of various parameters, using data assimilative tidal models and altimetry data as references. Semi-diurnal energy budgets are also computed. Throughout this work, a systematic comparison to HYCOM results (Ansong et al. 2015 and Buijsman et al. 2016) is performed.&amp;lt;/p&amp;gt; </jats:p