Métamorphose et ancestralité : Un nouveau regard sur les « dieux » des Iban de Sarawak (Malaysia)

Dans cet article, je propose que les « divinités » chez les Iban de Sarawak (Malaysia) sont en fait des ancêtres transformés en oiseaux et en animaux qui « font vivre les humains ». Sur le plan conceptuel, je m’inscris dans un courant contemporain de relectures de l’animisme. Au sein de celui-ci, je reprends l’approche relationnelle de l’ancestralité de Tim Ingold selon laquelle des entités invisibles de diverses origines prodiguent des soins aux humains. Sur le plan ethnographique, mon propos prolonge un débat initié par Sellato selon lequel une minorité de défunts deviennent des ancêtres au terme d’un processus rituel. Chez les Iban, une minorité de défunts devient des ancêtres, mais ce processus résulte, dans sa forme privilégiée, non pas de rituels mais de transformations qui créent une ligne d’ancestralité avec les règnes aviaire et animal.I suggest in this paper that Iban « gods » are in fact ancestors transformed in birds or animals who sustain human life. On the conceptual plan, my analysis is inscribed in a contemporary current which revisits animism. In that current, I am following Tim Ingold relational approach of ancestrality in which invisible beings of different origins nurture humans. On the ethnographic side, my argument enters the debate initiated by Sellato who considers that only a minority of deceased becomes ancestors following a ritual process. That argument applied to the Iban of Sarawak, but the creation of ancestors is not by means of rituals, but of metamorphosis which creates ancestrality with the aviary and animal kingdoms.En este artículo, propongo que las «divinidades» de los Iban de Sarawak (Malasia) en realidad son ancestros transformados en aves y en animales que «mantienen a los humanos». En el plano conceptual, me inscribo en una corriente contemporánea de relectura del animismo. Al interior de éste, retomo el enfoque relacional de la ancestralidad de Tim Ingold según el cual los entes invisibles de diversos orígenes prodigan cuidados a los humanos. En el plano etnográfico, mi propósito prolonga un debate iniciado por Sellato, según el cual una minoría de difuntos se convierte en ancestros, pero dicho proceso proviene, en su forma privilegiada, no de rituales sino de transformaciones que crean una línea de ancestralidad con los reinos aviario y animal

Accelerating parser combinators with macros

Parser combinators provide an elegant way of writing parsers: parser implementations closely follow the structure of the underlying grammar, while accommodating interleaved host language code for data processing. However, the host language features used for composition introduce substantial overhead, which leads to poor performance. In this paper, we present a technique to systematically eliminate this overhead. We use Scala macros to analyse the grammar specification at compile-time and remove composition, leaving behind an efficient top-down, recursive-descent parser. We compare our macro-based approach to a staging-based approach using the LMS framework, and provide an experience report in which we discuss the advantages and drawbacks of both methods. Our library outperforms Scala's standard parser combinators on a set of benchmarks by an order of magnitude, and is 2x faster than code generated by LMS

Identification of NF-κB Modulation Capabilities within Human Intestinal Commensal Bacteria

The intestinal microbiota plays an important role in modulation of mucosal immune responses. To seek interactions between intestinal epithelial cells (IEC) and commensal bacteria, we screened 49 commensal strains for their capacity to modulate NF-κB. We used HT-29/kb-seap-25 and Caco-2/kb-seap-7 intestinal epithelial cells and monocyte-like THP-1 blue reporter cells to measure effects of commensal bacteria on cellular expression of a reporter system for NF-κB. Bacteria conditioned media (CM) were tested alone or together with an activator of NF-κB to explore its inhibitory potentials. CM from 8 or 10 different commensal species activated NF-κB expression on HT-29 and Caco-2 cells, respectively. On THP-1, CM from all but 5 commensal strains stimulated NF-κB. Upon challenge with TNF-α or IL-1β, some CM prevented induced NF-κB activation, whereas others enhanced it. Interestingly, the enhancing effect of some CM was correlated with the presence of butyrate and propionate. Characterization of the effects of the identified bacteria and their implications in human health awaits further investigations

Impact of Leptospermone, a Natural β-Triketone Herbicide, on the Fungal Composition and Diversity of Two Arable Soils

Impact of leptospermone, a β-triketone bioherbicide, was investigated on the fungal community which supports important soil ecological functions such as decomposition of organic matter and nutrients recycling. This study was done in a microcosm experiment using two French soils, Perpignan (P) and Saint-Jean-de-Fos (SJF), differing in their physicochemical properties and history treatment with synthetic β-triketones. Soil microcosms were treated with leptospermone at recommended dose and incubated under controlled conditions for 45 days. Untreated microcosms were used as control. Illumina MiSeq sequencing of the internal transcribed spacer region of the fungal rRNA revealed significant changes in fungal community structure and diversity in both soils. Xylariales, Hypocreales, Pleosporales and Capnodiales (Ascomycota phyla) fungi and those belonging to Sebacinales, Cantharellales, Agaricales, Polyporales, Filobasidiales and Tremellales orders (Basidiomycota phyla) were well represented in treated soil microcosms compared to control. Nevertheless, while for the treated SJF a complete recovery of the fungal community was observed at the end of the experiment, this was not the case for the P treated soil, although no more bioherbicide remained. Indeed, the relative abundance of most of the saprophytic fungi were lower in treated soil compared to control microcosms whereas fungi from parasitic fungi included in Spizellomycetales and Pezizales orders increased. To the best of our knowledge, this is the only study assessing the effect of the bioherbicide leptospermone on the composition and diversity of the fungal community in soil. This study showed that leptospermone has an impact on α- and β-diversity of the fungal community. It underlines the possible interest of microbial endpoints for environmental risk assessment of biopesticide

Butyrate Produced by Commensal Bacteria Down-Regulates Indolamine 2,3-Dioxygenase 1 (IDO-1) Expression via a Dual Mechanism in Human Intestinal Epithelial Cells

Commensal bacteria are crucial for the development and maintenance of a healthy immune system therefore contributing to the global well-being of their host. A wide variety of metabolites produced by commensal bacteria are influencing host health but the characterization of the multiple molecular mechanisms involved in host-microbiota interactions is still only partially unraveled. The intestinal epithelial cells (IECs) take a central part in the host-microbiota dialogue by inducing the first microbial-derived immune signals. Amongst the numerous effector molecules modulating the immune responses produced by IECs, indoleamine 2,3-dioxygenase-1 (IDO-1) is essential for gut homeostasis. IDO-1 expression is dependent on the microbiota and despites its central role, how the commensal bacteria impacts its expression is still unclear. Therefore, we investigated the impact of individual cultivable commensal bacteria on IDO-1 transcriptional expression and found that the short chain fatty acid (SCFA) butyrate was the main metabolite controlling IDO-1 expression in human primary IECs and IEC cell-lines. This butyrate-driven effect was independent of the G-protein coupled receptors GPR41, GPR43, and GPR109a and of the transcription factors SP1, AP1, and PPARγ for which binding sites were reported in the IDO-1 promoter. We demonstrated for the first time that butyrate represses IDO-1 expression by two distinct mechanisms. Firstly, butyrate decreases STAT1 expression leading to the inhibition of the IFNγ-dependent and phosphoSTAT1-driven transcription of IDO-1. In addition, we described a second mechanism by which butyrate impairs IDO-1 transcription in a STAT1-independent manner that could be attributed to its histone deacetylase (HDAC) inhibitor property. In conclusion, our results showed that IDO-1 expression is down-regulated by butyrate via a dual mechanism: the reduction of STAT1 level and the HDAC inhibitor property of SCFAs