Characterization of Posidonia Oceanica Seagrass Aerenchyma through Whole Slide Imaging: A Pilot Study

Characterizing the tissue morphology and anatomy of seagrasses is essential to predicting their acoustic behavior. In this pilot study, we use histology techniques and whole slide imaging (WSI) to describe the composition and topology of the aerenchyma of an entire leaf blade in an automatic way combining the advantages of X-ray microtomography and optical microscopy. Paraffin blocks are prepared in such a way that microtome slices contain an arbitrarily large number of cross sections distributed along the full length of a blade. The sample organization in the paraffin block coupled with whole slide image analysis allows high throughput data extraction and an exhaustive characterization along the whole blade length. The core of the work are image processing algorithms that can identify cells and air lacunae (or void) from fiber strand, epidermis, mesophyll and vascular system. A set of specific features is developed to adequately describe the convexity of cells and voids where standard descriptors fail. The features scrutinize the local curvature of the object borders to allow an accurate discrimination between void and cell through machine learning. The algorithm allows to reconstruct the cells and cell membrane features that are relevant to tissue density, compressibility and rigidity. Size distribution of the different cell types and gas spaces, total biomass and total void volume fraction are then extracted from the high resolution slices to provide a complete characterization of the tissue along the leave from its base to the apex

Cosmology and Practice in Amazonia: The Inspiring Career of Stephen Hugh-Jones

Stephen Hugh-Jones’s ethnographic and collaborative engagement with the peoples of the Pirá-Paraná and, more widely, the Vaupés and Upper Rio Negro today spans 50 years. In this Introduction we chart the evolution of Hugh-Jones’s hybrid identity as iconoclast scholar, knowledgeable elder, and long-term collaborator. A biographical sketch identifies phases in this anthropological life: that of the ethnographer and initiate, steeped in the intellectual world of Barasana shaman-priests; that of lecturer and theorist in anthropology; and that of areal specialist, developing a synthesis of the ethnography of North West Amazonia through an engagement with Brazilian and indigenous intellectuals. We characterize the enduring hallmarks of Stephen’s work through very numerous and varied thematic interventions as the holding of the cosmological and esoteric together with the mundane, practical, and necessary; the foregrounding of commonalities between Amazonians and Europeans; and the open character of abstract models that allow for dissension, individual variation and historical transformation. Finally we introduce contributions to the two thematic sections of the Special Issue, the first on the form and gender of the universe in Northwest Amazonia, and the second on the politics of Amazonian indigenous Knowledge

Sibran Anne (scénariste) et Emmanuel Lepage (dessinateur), La Terre sans Mal, Dupuis, Paris, 1999, 64 p., 23 x 31 cm Pellejero Ruben (dessinateur) et Jorge Zentner (scénariste), Le Captif, Mosquito, St Egrève, 2002, 48 p., 23 x 30 cm [traduction française par Pablo Guevara de Europeos ante el nuevo mundo : el cautivo, Planeta-Agostini / Sociedad Estatal Quinto Centenario, Barcelona/Madrid, 1992]

Les textes non scientifiques consacrés à l’Amérique indigène ne sont pas souvent pris au sérieux par les ethnologues, et on pourrait croire que ce jugement mériterait d’être encore plus marqué à propos des bandes dessinées. Toutefois, La Terre sans Mal et Le Captif ont retenu toute notre attention, car ces ouvrages s’appuient sur des textes qui sont au cœur du patrimoine américaniste et ont parfois touché un public plus vaste : d’un côté, un récit romancé fondé sur les travaux de Pierre et Hé..

La parenté en substance

Parler d’un renouveau de la parenté en anthropologie est peut-être déjà devenu une banalité... En 2004 sont parus deux ouvrages, de chaque côté de la Manche, marqués par une ambition synthétique sur le sujet. Si d’un côté la parenté se transforme, de l’autre on se situe dans un «après»: comparer les questionnements et les interrogations qui marquent ce retour montrera peut-être que cette simultanéité n’est pas le signe d’une disparition des traditions et des spécificités nationales. La somme ..

De l’os, de l’ennemi et du divin. Réflexions sur quelques pratiques funéraires tupi-guarani

De l’os, de l’ennemi et du divin. Réflexions sur quelques pratiques funéraires tupi-guarani. En soulignant son importance dans les rites et les mythes tupi-guarani, cet article cherche à montrer que l’os n’est pas un support neutre et que ses différents modes de traitement permettent de discriminer, au sein des divers rites funéraires, deux pôles extrêmes. Ceux-ci sont définis par leur caractère agressif ou attentionné (à l’égard du défunt) et conditionnent en grande partie le destin post-mortem. Si le contraste maximal apparaît entre l’exo-cannibalisme vengeur et le culte des os, il existe également une gradation, culturellement déterminée et définie par le traitement des os, dans la consommation des dépouilles.Of Bones, enemies and divinities. Reflections on some Tupi-Guarani funerary practices. By underlining the importance of bone in Tupi-Guarani myth and ritual, this article seeks to demonstrate that bone is not a neutral substance, and that the different ways of treating it allow us to distinguish two major axes structuring various funerary rites. These axes are defined by their aggressive or caring attitude toward the deceased, and they largely determine one’s posthumous fate. If the greatest contrast is that between vengeful exo-cannibalism and the cult of bones, there is also, within the former, a culturally determined gradation in the treatment of the bones during consumption of the corpse.De los huesos, del enemigo y de lo divino. Reflexiones sobre algunas prácticas funerarias tupi-guarani. Subrayando la importancia del hueso en los ritos y mitos tupi-guarani, este artículo se propone mostrar que éste no es un soporte neutro y que sus diferentes modos de tratamiento permiten distinguir, en diversos ritos funerarios, dos polos extremos. Estos se definen por su carácter agresivo o intencionado (con respecto al difunto), y condicionan en gran parte el destino post-mortem. Si el contraste máximo aparece entre el exo-canibalismo vengativo y el culto del hueso, existe igualmente una graduación, determinada culturalmente y definida por el tratamiento de los huesos, en el consumo de los restos

Amazonian masters in theory and in practice

Luiz Costa has offered us an important and fascinating book on the topic of ownership in lowland South America (aka “Amazonia”), rich with ethnographic details, astute interpretations, and bold theorization. While deeply impressed by Costa’s work and convinced by many of his arguments, I also found myself disagreeing with as many other interpretations or developments he makes—some of which have to do with the purpose and nature of our work as anthropologists. I want to acknowledge this fact f..

Beckerman Stephen and Paul Valentine (eds), Cultures of multiple fathers. The theory and practice of partible paternity in Lowland South America, University Press of Florida, Gainesville, 2002, 291 p., bibl., index, ill., carte

La possibilité d’avoir plusieurs pères n’a jamais été écartée par l’anthropologie, mais en distinguant toujours l’unique genitor (biologique) des multiples pater (sociaux) : la coïncidence exceptionnelle entre les croyances populaires occidentales et la vérité scientifique a longtemps rendu tout autre approche impensable. Stephen Beckerman et Paul Valentine, dans un ouvrage qui réunit douze contributions, attirent notre attention sur ce phénomène, en s’intéressant à une « croyance » très répa..

Objets, personnes, esprits

L’Art et ses agents est un livre qui captive – comme un motif labyrinthique envoûte l’esprit d’un démon, comme un chef-d’œuvre fascine un spectateur – parce que l’argumentation, les rapprochements, les références, les analyses prennent toujours des tournures imprévues. Ce rapprochement est un peu convenu, et d’autres commentateurs ont déjà montré qu’il était possible de pasticher ainsi Alfred Gell en rendant compte de sa propre œuvre (Miller 2000 et, implicitement, Campbell 2001 : 117). Toute..

Morality and Emotion in the Dynamics of an Amerindian Society (Warao, Orinoco Delta, Venezuela)

This dissertation is a study of the interplay of moral issues and emotional states in the daily life of the Warao of the Orinoco Delta in Venezuela. Among the Warao, neither moral issues nor emotional processes are the subject of much explicit discursive elaboration. They usually emerge in a non-propositional or even non-verbal way as aspects of everyday and ritual interactions, and shape the course of those interactions, which are essentially dynamic processes. This dissertation is therefore essentially concerned with understanding the effect of people’s actions on one another, and with elucidating the role played by morality and emotion in such processes. The dissertation starts with a general description of interactions between Warao and outsiders, which centres on the acquisition and management of things (chapter 1) and continues with a consideration of the effects of the production and consumption of food upon such interactions (chapter 2). Both chapters stress how the moral issues surrounding such practices are central in accounting for the form taken by Warao sociality. Nurture, as a specific form of food consumption, also has long-lasting emotional effects, revealed by the saliency of childhood experiences in the definition of kinship networks, and of the schema of fosterage as an asymmetrical – yet valued – way of relating to others. Discourses and practices of care and nurture also abound around illness and shamanism, and such contexts present shamanic aggression as the archetypically immoral act. They also offer the opportunity to study how different types of discourse (ritual speech, gossip, etc.) and non-verbal acts have effects on the emotional state of those involved and on the nature of their relationships. Death offers another stage for the critical and reflexive evaluation of the behaviour of oneself and others, especially in funerary laments. But intense sorrow is not only conventionally expressed or channelled, it is also intentionally produced in circumscribed contexts, because it is a moral – albeit painful – state. By focusing on verbal and non-verbal acts in specific contexts, this study shows how moral reflexivity can be pervasive in spite of not being explicitly theorised, and how it is inextricably linked to emotional states which are produced by – as well as productive of – interaction

Evaluation of French motorway network in relation to slime mould transport networks

© The Author(s) 2016. France has developed a high quality motorway system that has been rapidly rationalised and matured in the late 20th century yet has been founded on ancient, Roman infrastructures. The development of the motorway system is thus an iterative method associated with hierarchical ‘top-down’ processes taking into consideration factors such as population density, network demand, location of natural resources, civil engineering challenges and population growth. At the opposite extreme to this approach is the development of transport networks within simple biological systems which are typically decentralised, dynamic and emerge from simple, local and ‘bottom-up’ interactions. We examine the notion, and to what extent, that the structure of a complex motorway network could be predicted by the transport network of the single-celled slime mould Physarum polycephalum. This comparison is explored through its ability to ‘deduce’ the French motorway network in a series of analogue and digital experiments. We compare Physarum network and motorway network topology in relation to proximity graphs and assess the trade-off between connectivity and minimal network length with a bottom-up model of a virtual plasmodium. We demonstrate that despite the apparent complexity of the challenge Physarum can successfully apply its embodied intelligence to rationalise the motorway topology. We also demonstrate that such calculations prove challenging in the face of significant obstacles such as, mountainous terrain and may account for the missing route between Nice, Grenoble Avignon and Lyon. Finally, we discuss the topological findings with respect to circle and spoke city planning infrastructures and certain species of web-building spiders