Genre, alliance et filiation dans les relations chamanes-esprits chez les Shipibo-Conibo : Un itinéraire de recherche conjointe et multisituée

Cet article montre comment une collaboration scientifique poursuivie pendant vingt ans entre deux anthropologues – Françoise Morin et Bernard Saladin d’Anglure – autour d’un intérêt commun pour le chamanisme leur a permis de faire des avancées théoriques et méthodologiques en combinant leurs problématiques, en croisant leurs données et en réalisant des enquêtes sur le terrain ensemble (Sibérie nord orientale, Arctique canadien et Amazonie péruvienne). Grâce à cette collaboration, nous avons mis en lumière des rapports subtils existant entre le chamanisme et certains domaines de la vie sociale : le politique, la parenté, la sexualité, le genre et les rites de passage ; et cela, tant dans les relations humaines, que dans celles qui existent entre les chamanes et certaines entités d’apparence humaine capables de se rendre invisibles, et considérées dans la littérature ethnographique comme une catégorie d’esprits. Ces rapports ont rarement été perçus et étudiés par l’ethnographie classique plus souvent cantonnée dans une approche monographique, avec un seul chercheur, un seul groupe, un seul terrain et un cadre conceptuel déterminé à l’avance.This article describes a 20-year-long scientific collaboration by two anthropologists with a common interest in shamanism: Françoise Morin and Bernard Saladin d’Anglure. Through this partnership, they have made theoretical and methodological advances by combining their research issues, by cross-tabulating their data, and by conducting fieldwork together (northeastern Siberia, Canadian Arctic, and Peruvian Amazonia). They have thus shed light on the subtle relationships between shamanism and certain areas of social life, such as politics, kinship, sexuality, gender, and rites of passage, both in human relations and in relations between shamans and human-looking entities who can make themselves invisible and are considered in the ethnographic literature to be a category of spirits. These relations have seldom been perceived and studied by classical ethnography, which has more often been confined to a monograph approach with one researcher, one group, one fieldwork location, and one predetermined conceptual framework.Este artículo muestra cómo una colaboración científica realizada durante veinte años entre dos antropólogos –Françoise Morin y Bernard Saladin d’Anglure- en torno de un interés común por el chamanismo les ha permitido realizar avances teóricos y metodológicos combinando sus problemáticas, cruzando sus datos y realizando encuestas conjuntas en el campo (Siberia nororiental, Ártico canadiense y Amazonia peruana). Gracia a dicha colaboración, hemos mostrado relaciones sutiles entre chamanismo y ciertos ámbitos de la vida social: la política, el parentesco, la sexualidad, el genero y los ritos de pasaje; esto, tanto en las relaciones humanas que en aquellas que existen entre los chamanes y ciertas entidades de apariencia humana capaces de volverse invisibles, y consideradas en la literatura etnográfica como una categoría de espíritus. Esas relaciones han sido raramente percibidas y estudiadas por la etnográfica clásica, normalmente confinada en un enfoque monográfico, con un solo investigador, un solo grupo, un solo terreno y un cuadro conceptual previamente determinado

Caractérisation in vivo des fonctions des facteurs de transcription ribosomique UBF et TTF-1

Dans le but d'élucider les mécanismes de régulation de la transcription de l'ARN ribosomique et de la biosynthèse des ribosomes, deux facteurs de transcription ribosomique, soit UBF et TTF -l, furent étudiés dans le but de mieux caractériser leurs fonctions in vivo. Un modèle , de désactivation conditionnelle du gène codant pour UBF chez la souris fut élaboré. Après l'inactivation d'un allèle chez des animaux hétérozygotes aucun défaut développemental, physique ou comportemental n'a été observé lors d' investigations préliminaires. Un modèle de diminution inductible de TTF-I par le ciblage par shRNAmir fut développé. Des études de marquage métabolique au tritium ont permis de conclure qu'une diminution de TTF -l avait un effet appréciable sur la transcription ribosomique et un effet encore plus marqué sur la maturation des ARN ribosomiques. On voit une inhibition claire et nette de la maturation des ARN ribosomiques et aucune accumulation appréciable du précurseur ce qui indique aussi un problème de transcription. Des études du cycle cellulaire, effectués par ±fluorescence-assisted cell sorting¿, ont permis de détecter un arrêt partiel en G 1 qui se traduit en une diminution de la vitesse de passage de la phase G 1 à G2/M lors d'une diminution de TTF-I. Finalement, un modèle de récupération fut développé en introduisant un vecteur conditionnel capable d'exprimer la forme pleine longueur de TTF-I dans les cellules de diminution conditionnelle. L'induction double et simultanée d'une forme pleine longueur de TTF-I et du shRNAmir ciblant TTF-I permit la récupération de la diminution de TTF -l chez ces cellules. Ce modèle de récupération permit de confirmer que les effets observés étaient dus à la diminution de TTF -l en excluant des effets secondaires

Les sources du Centre de recherches politiques de Sciences Po

En France, les sources sur l’histoire politique contemporaine, et particulièrement les élections, sont très dispersées. Au Centre de recherches politiques de Sciences Po, les documents de travail des chercheurs en science politique d’hier peuvent pleinement servir aux historiens d'aujourd’hui. [Premier paragraphe

Mariage mystique et pouvoir chamanique chez les Shipibo d'Amazonie péruvienne et les Inuit du Nunavut canadien

RÉSUMÉMariage mystique et pouvoir chamanique chez les Shipibo d'Amazonie péruvienne et les Inuit du Nunavut canadienLes auteurs adoptent une approche ethnographique néo-comparatiste pour étudier les médiations chamaniques chez deux peuples autochtones des Amériques. Ils s'intéressent tout d'abord à la sexualité onirique entre les esprits et les humains, puis aux relations de parenté (alliance et filiation) des chamanes avec leurs esprits auxiliaires. Ces relations sont une source de pouvoir, soit qu'elles déterminent de nouveaux destins chamaniques, soit qu'elles consacrent la fin de l'apprentissage et le pouvoir de médiation des grands chamanes avec les esprits. Le travestissement, perceptible aux sens ou symbolique, et l'androgynie expriment la capacité des chamanes à chevaucher toutes les frontières.Mots-clés : Saladin d'Anglure, Morin, chamanisme, sexe, genre, travestissement, androgynie, rêve, mariage mystique, Amazonie, Shipibo, Arctique, InuitABSTRACTMystical Marriages and Shamanistic Powers among the Shipibo of Amazonia (Peru) and the Inuit from Nunavut (Canada)The authors adopt a neo-comparatist ethnographie approach to study cases of shamanistic mediation in two aboriginal peoples of the Americas. They first look into dream sexuality between spirits and humans, and then into the kinship (by marriage and descent) of shamans with their helping spirits. These relationships are a source of power. They may engender future shamans or they may sanction the end of the learning period and consecrate the mediating power of great shamans with the spirits. Shamans can eut across ail boundaries through androgyny and through transvestism, be it symbolic or concrete (i.e., ils outward signs can be seen, heard or smelled).Key words : Saladin d'Anglure, Morin, shamanism, sex, gender, transvestism, androgyny, dreams, mystical marriage, Amazonia, Shipibo, Arctic, Inui

B cell-dependent EAE induces visual deficits in the mouse with similarities to human autoimmune demyelinating diseases.

BACKGROUND In the field of autoimmune demyelinating diseases, visual impairments have extensively been studied using the experimental autoimmune encephalomyelitis (EAE) mouse model, which is classically induced by immunization with myelin oligodendrocyte glycoprotein peptide (MOG35-55). However, this model does not involve B cells like its human analogs. New antigens have thus been developed to induce a B cell-dependent form of EAE that better mimics human diseases. METHODS The present study aimed to characterize the visual symptoms of EAE induced with such an antigen called bMOG. After the induction of EAE with bMOG in C57BL/6J mice, visual function changes were studied by electroretinography and optomotor acuity tests. Motor deficits were assessed in parallel with a standard clinical scoring method. Histological examinations and Western blot analyses allowed to follow retinal neuron survival, gliosis, microglia activation, opsin photopigment expression in photoreceptors and optic nerve demyelination. Disease effects on retinal gene expression were established by RNA sequencing. RESULTS We observed that bMOG EAE mice exhibited persistent loss of visual acuity, despite partial recovery of electroretinogram and motor functions. This loss was likely due to retinal inflammation, gliosis and synaptic impairments, as evidenced by histological and transcriptomic data. Further analysis suggests that the M-cone photoreceptor pathway was also affected. CONCLUSION Therefore, by documenting visual changes induced by bMOG and showing similarities to those seen in diseases such as multiple sclerosis and neuromyelitis optica, this study offers a new approach to test protective or restorative ophthalmic treatments

Decoupling of arsenic and iron release from ferrihydrite suspension under reducing conditions: a biogeochemical model

High levels of arsenic in groundwater and drinking water are a major health problem. Although the processes controlling the release of As are still not well known, the reductive dissolution of As-rich Fe oxyhydroxides has so far been a favorite hypothesis. Decoupling between arsenic and iron redox transformations has been experimentally demonstrated, but not quantitatively interpreted. Here, we report on incubation batch experiments run with As(V) sorbed on, or co-precipitated with, 2-line ferrihydrite. The biotic and abiotic processes of As release were investigated by using wet chemistry, X-ray diffraction, X-ray absorption and genomic techniques. The incubation experiments were carried out with a phosphate-rich growth medium and a community of Fe(III)-reducing bacteria under strict anoxic conditions for two months. During the first month, the release of Fe(II) in the aqueous phase amounted to only 3% to 10% of the total initial solid Fe concentration, whilst the total aqueous As remained almost constant after an initial exchange with phosphate ions. During the second month, the aqueous Fe(II) concentration remained constant, or even decreased, whereas the total quantity of As released to the solution accounted for 14% to 45% of the total initial solid As concentration. At the end of the incubation, the aqueous-phase arsenic was present predominately as As(III) whilst X-ray absorption spectroscopy indicated that more than 70% of the solid-phase arsenic was present as As(V). X-ray diffraction revealed vivianite Fe(II)3(PO4)2.8H2O in some of the experiments. A biogeochemical model was then developed to simulate these aqueous- and solid-phase results. The two main conclusions drawn from the model are that (1) As(V) is not reduced during the first incubation month with high Eh values, but rather re-adsorbed onto the ferrihydrite surface, and this state remains until arsenic reduction is energetically more favorable than iron reduction, and (2) the release of As during the second month is due to its reduction to the more weakly adsorbed As(III) which cannot compete against carbonate ions for sorption onto ferrihydrite. The model was also successfully applied to recent experimental results on the release of arsenic from Bengal delta sediments

Specificity of Anti-Tau Antibodies when Analyzing Mice Models of Alzheimer's Disease: Problems and Solutions

Aggregates of hyperphosphorylated tau protein are found in a group of diseases called tauopathies, which includes Alzheimer's disease. The causes and consequences of tau hyperphosphorylation are routinely investigated in laboratory animals. Mice are the models of choice as they are easily amenable to transgenic technology; consequently, their tau phosphorylation levels are frequently monitored by Western blotting using a panel of monoclonal/polyclonal anti-tau antibodies. Given that mouse secondary antibodies can recognize endogenous mouse immunoglobulins (Igs) and the possible lack of specificity with some polyclonal antibodies, non-specific signals are commonly observed. Here, we characterized the profiles of commonly used anti-tau antibodies in four different mouse models: non-transgenic mice, tau knock-out (TKO) mice, 3xTg-AD mice, and hypothermic mice, the latter a positive control for tau hyperphosphorylation. We identified 3 tau monoclonal antibody categories: type 1, characterized by high non-specificity (AT8, AT180, MC1, MC6, TG-3), type 2, demonstrating low non-specificity (AT270, CP13, CP27, Tau12, TG5), and type 3, with no non-specific signal (DA9, PHF-1, Tau1, Tau46). For polyclonal anti-tau antibodies, some displayed non-specificity (pS262, pS409) while others did not (pS199, pT205, pS396, pS404, pS422, A0024). With monoclonal antibodies, most of the interfering signal was due to endogenous Igs and could be eliminated by different techniques: i) using secondary antibodies designed to bind only non-denatured Igs, ii) preparation of a heat-stable fraction, iii) clearing Igs from the homogenates, and iv) using secondary antibodies that only bind the light chain of Igs. All of these techniques removed the non-specific signal; however, the first and the last methods were easier and more reliable. Overall, our study demonstrates a high risk of artefactual signal when performing Western blotting with routinely used anti-tau antibodies, and proposes several solutions to avoid non-specific results. We strongly recommend the use of negative (i.e., TKO) and positive (i.e., hypothermic) controls in all experiments