Emplir les corps des dieux pour rassasier les hommes

Chaque année, chez les Kabyè du Togo, le parcours rituel organisé pour soutenir le développement final du petit mil et annoncer la tenue de nouvelles sessions initiatiques donne lieu à une importante alcoolisation d’un jeune garçon, dont la participation au rite consiste avant tout à marcher, puis à boire. Sur quels ressorts symboliques l’efficacité de cette pratique rituelle s’appuie-t-elle ? Après une description analytique et contextualisée de cet usage du boire, nous trouverons des éléments de réponse dans les représentations relatives au corps des enfants, et dans une mise en regard avec d’autres rituels qui impliquent d’emplir de bière ou de substances dérivées de la fabrication de la bière des réceptacles de forme humaine. Il s’agit dans tous les cas de créer l’image d’une réplétion agissant comme une injonction à l’abondance adressée aux divinités.Each year, in the Kabye society, a boy takes part in a ritual route supporting the final growth of millet and announcing the beginning of initiations. Above all, his participation consists in walking and ingesting a large amount of sorghum beer. On which symbolical motives does the efficacy of this alcoholization practice rest? After describing and analyzing the context surrounding this drinking custom, some answers will arise from representations related to the children’s body. This practice will also be put into perspective with other rites entailing to fill anthropomorphous receptacles with beer or with matters derived from beer making. All these rites aim to create the image of satiety, acting as a request for abundance addressed to the divinities

Enantiomeric resolution of helicochiral paddlewheel complexes and their infrared, Raman, UV-vis and X-ray optical activity

International audienceLinear polynuclear paddlewheel complexes-"extended metal atom chains" or "metal strings"-have provided attractive models for the study of metal-metal bonding, magnetism and conductivity since their discovery in the 1990s [1]. Their helicoidal chirality, arising from mutual steric hindrance of the 3-pyridyl protons, resulting in the twisting of the equatorial ligand around the metal axis (see figure), has been less studied. Nonetheless, in one of the few examples of chiral resolution, the obtained enantiomers of a trinickel complex showed a remarkably high specific rotation of 5000 deg•mL•g −1 •dm −1 [2], motivating us to seek a general technique for the chiral resolution of such racemates. We have developed a procedure based on anion exchange for the chiral resolution of [M3(dpa)4] 2+ salts (M = Co(II) or Ni(II), Hdpa = 2,2'-dipyridylamine). Homochiral arsenyl tartrate (AsT) salts promoted the selective crystallization of [-M3(dpa)4(MeCN)2](NBu4)2[-AsT]2, or [-M3(dpa)4(MeCN)2](NBu4)2[-AsT]2 in the P4212 space group. The enantiopure compounds demonstrated surprisingly large optical activities using UV-vis, Raman and infrared spectroscopy in solution and, for the cobalt derivatives, in the X-ray range at the Co K-edge in single crystals. An intense X-ray linear dichroism was observed in the orthoaxial crystal orientation, whereas it vanished in the axial confirmation, while the angular dependence of the circular dichroism spectra followed the expected (3cos 2 − 1) function, thus spectroscopically confirming the D4 crystal symmetry. X-ray magnetic circular dichroism and X-ray magnetochiral dichroism signals at the Co K-edge were not detected, likely due to a strongly delocalized spin density on the metal-metal bonded tricobalt core. Nevertheless, these results establish that chiral polynuclear paddlewheel complexes can be cleanly resolved using selective crystallization and demonstrate considerable optical activity in the infrared, UV-vis and X-ray energy ranges, thus potentially offering future perspectives in non-linear optics and asymmetric synthesis [3]

Elementary Reactions and Their Role in Gas-Phase Prebiotic Chemistry

The formation of complex organic molecules in a reactor filled with gaseous mixtures possibly reproducing the primitive terrestrial atmosphere and ocean demonstrated more than 50 years ago that inorganic synthesis of prebiotic molecules is possible, provided that some form of energy is provided to the system. After that groundbreaking experiment, gas-phase prebiotic molecules have been observed in a wide variety of extraterrestrial objects (including interstellar clouds, comets and planetary atmospheres) where the physical conditions vary widely. A thorough characterization of the chemical evolution of those objects relies on a multi-disciplinary approach: 1) observations allow us to identify the molecules and their number densities as they are nowadays; 2) the chemistry which lies behind their formation starting from atoms and simple molecules is accounted for by complex reaction networks; 3) for a realistic modeling of such networks, a number of experimental parameters are needed and, therefore, the relevant molecular processes should be fully characterized in laboratory experiments. A survey of the available literature reveals, however, that much information is still lacking if it is true that only a small percentage of the elementary reactions considered in the models have been characterized in laboratory experiments. New experimental approaches to characterize the relevant elementary reactions in laboratory are presented and the implications of the results are discussed

Parrainage initiatique et confiage rituel. Une relation de pseudo-parenté du point de vue des enfants (pays kabyè, Togo)

Dans une partie du pays kabyè, l’organisation des initiations masculine et féminine implique l’élaboration d’une relation de pseudo-filiation entre un.e novice âgé.e d’environ vingt ans et un enfant. Considérer les modalités de constitution de cette relation et de son évolution – le confiage rituel initial, les implications symboliques, formelles et affectives de cet apparentement – permet de montrer, d’une part, que les enfants non-initiés jouent eux-mêmes ici un rôle d’initiateurs construisant l’initiant.e en père ou mère potentiel.le, et d’autre part, que la nécessité de porter attention aux plaisirs et déplaisirs des enfants confère à ces derniers une capacité d’action sur les conditions de formation de leur lien de pseudo-filiation. La parenté rituelle est pensée ici comme un préalable logique à la parenté biologique, le ou la « filleul.e » apparaissant comme un opérateur symbolique du passage de l’une à l’autre