Las visiones y los mundos: depredación, transformación y equilibrio en discursos de la Amazonía occidental

[À l'origine dans / Was originally part of : Thèses et mémoires - FAS - Département de littératures et de langues modernes]Ce travail se veut d’un rapprochement aux pratiques et savoirs des peuples amazoniens à partir de discours produits par ces nations. Nous y interpréterons des chants sacrés, des narrations ancestrales et des textes académiques de penseurs autochtones. Ce travail indique que les pratiques amazoniennes s’inscrivent dans un contexte de significations qui considèrent que tout être vivant possède des pensées et un esprit; qu’il existe des êtres spirituels qui défendent ces êtres vivants contre les abus possibles. Les êtres humains doivent transcender leur état de conscience, se déplacer vers les mondes invisibles et initier la communication avec ces esprits, pour ainsi maintenir l’équilibre existentiel. Selon les pensées de l’Amazonie, les communautés humaines ne peuvent pas se concevoir comme autosuffisantes; elles doivent plutôt maintenir de constantes relations avec les multiples êtres qui peuplent leur environnement visible et les mondes invisibles. Les trois concepts clés qui permettent de rendre compte des pratiques des peuples amazoniens sont la déprédation, la transformation et l’équilibre. Par déprédation, nous entendons les pratiques amazoniennes qui impliquent une destruction des autres êtres afin de sustenter la vie de la communauté. Selon les pensées de l’Amazonie, cette déprédation devrait être mesurée, dans le but de ne pas tuer plus que nécessaire à la survie. La déprédation est régulée par les êtres spirituels. Les pratiques amazoniennes de transformation sont destinées à la sauvegarde des liens de la communauté, en transfigurant tout ce qui entre ou sort de cette dernière, de manière à ce qu’aucun agent externe ne mette en péril les liens affectifs. Les pratiques de déprédation et de transformation sont complémentaires et elles requièrent toutes les deux de se produire de manière équilibrée, en respectant les savoirs ancestraux et les lois cosmiques établies par les esprits supérieurs. En ce qui a trait à la méthode d’analyse, nous aborderons les discours de l’Amazonie à partir leur propre logique culturelle, sans imposer des méthodologies préétablies, ce qui donne comme résultat un travail académique qui approfondie la production intellectuelle interculturelle, puisque ce sont les voix indigènes qui expriment elles-mêmes leurs conceptions et le sens de leurs pratiques. Dans son ensemble, le travail engage un dialogue critique avec son champ d’étude en discutant ou en approfondissant certaines conceptions forgées par la littérature anthropologique consacrée à l’étude de la région, à partir des savoirs ancestraux amazoniens qui nourrissent les pratiques de ces nations.This dissertation delves into the knowledge-practices of Amazonian peoples, drawing on discourses produced by members of these nations. It explores sacred songs, stories and academic texts of ancient Indian thinkers. The dissertation signals that Amazonian practices belong to a context of meanings which consider that all living beings have thoughts and spirit; that spiritual beings defend these living beings against possible abuses. Human beings must transcend their state of consciousness, navigate the invisible worlds and establish communication with these spirits to uphold existential balance. According to Amazonian thought, human communities are not self-sufficient and must maintain a constant relationship with the multiplicity of beings that populate the visible environment and invisible worlds. Three key concepts account for the practices of Amazonian peoples: depredation, transformation and balance. Depredation refers to Amazonian practices involving the destruction of other beings in order to sustain the life of the community. According to Amazonian thought, depredation should be measured and only that which is necessary for survival should be killed. Depredation is governed by spiritual beings. Amazonian transformation practices are designed to safeguard community ties, transfiguring all that enters or leaves it, so that no external agent may jeopardize these ties of affection. The practices of depredation and transformation are complementary and both must be carried out in a balanced manner, respecting ancestral knowledge and cosmic laws established by higher spirits. With regard to the method of analysis, the dissertation considers Amazonian discourses from their own cultural logic and does not impose pre-established methodologies on them. Consequently, the present scholarly work makes a profound attempt at achieving an intercultural intellectual production; as it is indigenous voices themselves that express their ideas and the meaning of their practices. Overall, the dissertation enters into a critical dialogue with its field of study, both challenging and broadening certain concepts forged by the anthropological literature dedicated to the region’s study, drawing on the ancient Amazonian knowledge that nurtures the practices of those nations.El presente trabajo es una aproximación a los saberes-prácticas de las naciones de la Amazonía occidental, a partir de discursos producidos por miembros de esas mismas naciones. Se interpretarán cantos sagrados, narraciones ancestrales y textos académicos de pensadores indígenas. El trabajo señala que las prácticas amazónicas occidentales se enmarcan dentro de un contexto de significaciones que consideran que todo ser vivo tiene pensamientos y espíritu; que existen seres espirituales que defienden a estos seres vivos contra posibles abusos. Los seres humanos deben trascender su estado de conciencia, desplazarse a los mundos invisibles y entablar comunicación con estos espíritus, para de esa manera mantener el equilibrio existencial. Para los pensamientos amazónicos occidentales, las comunidades humanas no pueden pensarse autosuficientes, sino que deben mantener constantes relaciones con la multiplicidad de seres que pueblan su entorno visible y los mundos invisibles. Tres conceptos claves que permiten dar cuenta de las prácticas de los pueblos de la Amazonía occidental son depredación, transformación y equilibrio. Por depredación se entienden las prácticas amazónicas que implican una destrucción de otros seres para sustentar la vida de la comunidad. Según los pensamientos amazónicos occidentales, esta depredación debe ser medida, sin asesinar más de lo necesario para subsistir. La depredación se encuentra regulada por los seres espirituales. Las prácticas amazónicas de transformación están destinadas a salvaguardar los vínculos de la comunidad, transfigurando todo aquello que entra o sale de la misma, de tal manera que ningún agente externo ponga en peligro los vínculos de afecto. Las prácticas de depredación y transformación son complementarias y ambas requieren hacerse de manera equilibrada, respetando los saberes ancestrales y las leyes cósmicas establecidas por los espíritus superiores. En cuanto al método de análisis, se abordan los discursos amazónicos occidentales a partir de sus propias lógicas culturales, sin imponerles metodologías pre-establecidas, lo que da como resultado un trabajo académico que sigue ahondado en el intento de llegar a una producción intelectual intercultural, siendo las voces indígenas mismas las que expresan sus concepciones y los sentidos de sus prácticas. En su conjunto, el trabajo entabla un diálogo crítico con su campo de estudio, discutiendo o ahondando ciertas concepciones forjadas por la literatura antropológica dedicada al estudio de la región, a partir de aquellos saberes ancestrales de la Amazonía occidental que nutren las prácticas de esas naciones

The trophoblast giant cells of cricetid rodents

Giant cells are a prominent feature of placentation in cricetid rodents. Once thought to be maternal in origin, they are now known to be trophoblast giant cells (TGCs). The large size of cricetid TGCs and their nuclei reflects a high degree of polyploidy. While some TGCs are found at fixed locations, others migrate throughout the placenta and deep into the uterus where they sometimes survive postpartum. Herein, we review the distribution of TGCs in the placenta of cricetids, including our own data from the New World subfamily Sigmodontinae, and attempt a comparison between the TGCs of cricetid and murid rodents. In both families, parietal TGCs are found in the parietal yolk sac and as a layer between the junctional zone and decidua. In cricetids alone, large numbers of TGCs, likely from the same lineage, accumulate at the edge of the placental disk. Common to murids and cricetids is a haemotrichorial placental barrier where the maternal-facing layer consists of cytotrophoblasts characterized as sinusoidal TGCs. The maternal channels of the labyrinth are supplied by trophoblast-lined canals. Whereas in the mouse these are lined largely by canal TGCs, in cricetids canal TGCs are interspersed with syncytiotrophoblast. Transformation of the uterine spiral arteries occurs in both murids and cricetids and spiral artery TGCs line segments of the arteries that have lost their endothelium and smooth muscle. Since polyploidization of TGCs can amplify selective genomic regions required for specific functions, we argue that the TGCs of cricetids deserve further study and suggest avenues for future research

Placentation in Sigmodontinae: a rodent taxon native to South America

Background: Sigmodontinae, known as ""New World rats and mice,"" is a large subfamily of Cricetidae for which we herein provide the first comprehensive investigation of the placenta. Methods: Placentas of various gestational ages ranging from early pregnancy to near term were obtained for five genera, i.e. Necromys, Euryoryzomys, Cerradomys, Hylaeamys, and Oligoryzomys. They were investigated by means of histology, immunohistochemistry, a proliferation marker, DBA-lectin staining and transmission electron microscopy. Results: The chorioallantoic placenta was organized in a labyrinthine zone, spongy zone and decidua and an inverted yolk sac persisted until term. The chorioallantoic placenta was hemotrichorial. The interhemal barrier comprised fetal capillary endothelium and three layers of trophoblast, an outermost, cellular layer and two syncytial ones, with interspersed trophoblast giant cells (TGC). In addition, accumulations of TGC occurred below Reichert's membrane. The junctional zone contained syncytial trophoblast, proliferative cellular trophoblast, glycogen cells and TGC that were situated near to the maternal blood channels. In three of the genera, TGC were also accumulated in distinct areas at the placental periphery. PAS-positive glycogen cells derived from the junctional zone invaded the decidua. Abundant maternal uNK cells with positive response to PAS, vimentin and DBA-lectin were found in the decidua. The visceral yolk sac was completely inverted and villous. Conclusion: The general aspect of the fetal membranes in Sigmodontinae resembled that found in other cricetid rodents. Compared to murid rodents there were larger numbers of giant cells and in some genera these were seen to congregate at the periphery of the placental disk. Glycogen cells were found to invade the decidua but we did not identify trophoblast in the walls of the deeper decidual arteries. In contrast these vessels were surrounded by large numbers of uNK cells. This survey of wild-trapped specimens from five genera is a useful starting point for the study of placentation in an important subfamily of South American rodents. We note, however, that some of these rodents can be captive bred and recommend that future studies focus on the study of time dated pregnancies.This research was supported by grants from FAPESP (Proc. 07/51491-3 and\ud 09/53392-8)

Chorioallantoic and yolk sac placentation in the plains viscacha (Lagostomus maximus) - A caviomorph rodent with natural polyovulation

Objectives: Reproduction in the plains viscacha is characterized by the polyovulation of hundreds of oocytes, the loss of implantation and the development of 1-3 offspring. Our goal was to determine whether placental development was affected by these specializations. Study design: Thirteen placentas from early pregnancy to near-term pregnancy were analyzed using histological, immunohistochemical and transmission electron microscopy. Results: An inverted, villous yolk sac was present. Placentas were formed by the trophospongium, labyrinth and subplacenta. A lobulated structure with a hemomonochorial barrier was established early in pregnancy. Proliferating trophoblast that was clustered at the outer border and inside the labyrinth was responsible for placental growth. Trophoblast invasion resulted from the cellular trophoblast and syncytial streamers derived from the subplacenta. Different from other caviomorphs, numerous giant cells were observed. Conclusions: The principle processes of placentation in caviomorphs follow an extraordinarily stable pattern that is independent of specializations, such as polyovulation.Facultad de Ciencias Veterinaria

Realization and high power test of damped C -band accelerating structures

The linac of the European project Extreme Light Infrastructure-Nuclear Physics (ELI-NP) foresees the use of 12 traveling wave C-band accelerating structures. The cavities are 1.8 m long, quasiconstant gradient, and have a field phase advance per cell of 2π/3. They operate at 100 Hz repetition rate, and, because of the multibunch operation, they have been designed with a dipole higher-order mode (HOM) damping system to avoid beam breakup. The structures have symmetric input and output couplers and integrate, in each cell, a damping system based on silicon carbide (SiC) rf absorbers coupled to each cell through waveguides. An optimization of the electromagnetic and mechanical design has been done to simplify the fabrication and to reduce the costs. The cavities have been fabricated, and the first full-scale prototype has been also successfully tested at the nominal gradient of 33 MV/m, repetition rate of 100 Hz, and pulse length of 820 ns. It represents, to our knowledge, the first full-scale linac structure with HOM damping waveguides and SiC absorbers tested at this high gradient. In the paper, we illustrate the realization process of such a complicated device together with the low and high power test results

On the (parameterized) complexity of recognizing well-covered (r,l)-graphs.

An (r,ℓ)(r,ℓ)-partition of a graph G is a partition of its vertex set into r independent sets and ℓℓ cliques. A graph is (r,ℓ)(r,ℓ) if it admits an (r,ℓ)(r,ℓ)-partition. A graph is well-covered if every maximal independent set is also maximum. A graph is (r,ℓ)(r,ℓ)-well-covered if it is both (r,ℓ)(r,ℓ) and well-covered. In this paper we consider two different decision problems. In the (r,ℓ)(r,ℓ)-Well-Covered Graph problem ((r,ℓ)(r,ℓ) wcg for short), we are given a graph G, and the question is whether G is an (r,ℓ)(r,ℓ)-well-covered graph. In the Well-Covered (r,ℓ)(r,ℓ)-Graph problem (wc (r,ℓ)(r,ℓ) g for short), we are given an (r,ℓ)(r,ℓ)-graph G together with an (r,ℓ)(r,ℓ)-partition of V(G) into r independent sets and ℓℓ cliques, and the question is whether G is well-covered. We classify most of these problems into P, coNP-complete, NP-complete, NP-hard, or coNP-hard. Only the cases wc(r, 0)g for r≥3r≥3 remain open. In addition, we consider the parameterized complexity of these problems for several choices of parameters, such as the size αα of a maximum independent set of the input graph, its neighborhood diversity, or the number ℓℓ of cliques in an (r,ℓ)(r,ℓ)-partition. In particular, we show that the parameterized problem of deciding whether a general graph is well-covered parameterized by αα can be reduced to the wc (0,ℓ)(0,ℓ) g problem parameterized by ℓℓ, and we prove that this latter problem is in XP but does not admit polynomial kernels unless coNP⊆NP/polycoNP⊆NP/poly

Morphometric analysis of the placenta in the New World mouse Necromys lasiurus (Rodentia, Cricetidae): a comparison of placental development in cricetids and murids

Background: Stereology is an established method to extrapolate three-dimensional quantities from two-dimensional images. It was applied to placentation in the mouse, but not yet for other rodents. Herein, we provide the first study on quantitative placental development in a sigmodontine rodent species with relatively similar gestational time. Placental structure was also compared to the mouse, in order to evaluate similarities and differences in developmental patterns at the end of gestation. Methods: Fetal and placental tissues of Necromys lasiurus were collected and weighed at 3 different stages of gestation (early, mid and late gestation) for placental stereology. The total and relative volumes of placenta and of its main layers were investigated. Volume fractions of labyrinth components were quantified by the One Stop method in 31 placentae collected from different individuals, using the Mercator® software. Data generated at the end of gestation from N. lasiurus placentae were compared to those of Mus musculus domesticus obtained at the same stage. Results: A significant increase in the total absolute volumes of the placenta and its main layers occurred from early to mid-gestation, followed by a reduction near term, with the labyrinth layer becoming the most prominent area. Moreover, at the end of gestation, the total volume of the mouse placenta was significantly increased compared to that of N. lasiurus although the proportions of the labyrinth layer and junctional zones were similar. Analysis of the volume fractions of the components in the labyrinth indicated a significant increase in fetal vessels and sinusoidal giant cells, a decrease in labyrinthine trophoblast whereas the proportion of maternal blood space remained stable in the course of gestation. On the other hand, in the mouse, volume fractions of fetal vessels and sinusoidal giant cells decreased whereas the volume fraction of labyrinthine trophoblast increased compared to N. lasiurus placenta. Conclusions: Placental development differed between N. lasiurus and M. musculus domesticus. In particular, the low placental efficiency in N. lasiurus seemed to induce morphological optimization of fetomaternal exchanges. In conclusion, despite similar structural aspects of placentation in these species, the quantitative dynamics showed important differences.For technical support we thank Marie-Christine Aubrière, Michèle Dahirel of the Institut National de la Recherche Agronomique, Jouy-en-Josas, as well as members of the Universidade Federal Rural do Semi-Árido, Mossoró. We thank also Yves Maurin for Nanozoomer facilities. This research was supported by INRA and by grants from FAPESP (Process number: 09/53392-8).INRAFAPESP [09/53392-8