258 research outputs found

    Long-Range Activation of Systemic Immunity through Peptidoglycan Diffusion in Drosophila

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    The systemic immune response of Drosophila is known to be induced both by septic injury and by oral infection with certain bacteria, and is characterized by the secretion of antimicrobial peptides (AMPs) into the haemolymph. To investigate other possible routes of bacterial infection, we deposited Erwinia carotovora (Ecc15) on various sites of the cuticle and monitored the immune response via expression of the AMP gene Diptericin. A strong response was observed to deposition on the genital plate of males (up to 20% of a septic injury response), but not females. We show that the principal response to genital infection is systemic, but that some AMPs, particularly Defensin, are induced locally in the genital tract. At late time points we detected bacteria in the haemolymph of immune deficient RelishE20 flies, indicating that the genital plate can be a route of entry for pathogens, and that the immune response protects flies against the progression of genital infection. The protective role of the immune response is further illustrated by our observation that RelishE20 flies exhibit significant lethality in response to genital Ecc15 infections. We next show that a systemic immune response can be induced by deposition of the bacterial elicitor peptidoglycan (PGN), or its terminal monomer tracheal cytotoxin (TCT), on the genital plate. This immune response is downregulated by PGRP-LB and Pirk, known regulators of the Imd pathway, and can be suppressed by the overexpression of PGRP-LB in the haemolymph compartment. Finally, we provide strong evidence that TCT can activate a systemic response by crossing epithelia, by showing that radiolabelled TCT deposited on the genital plate can subsequently be detected in the haemolymph. Genital infection is thus an intriguing new model for studying the systemic immune response to local epithelial infections and a potential route of entry for naturally occurring pathogens of Drosophila

    Transposing tirtha: Understanding religious reforms and locative piety in early modern Hinduism

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    The paper deals with a historical and hitherto obscure case of de-commercialisation of sacred geography of India. Sahajanand Swami, an eighteenth century religious leader from Gujarat who became popular as Bhagwan Swaminarayan took an initiative to eliminate corruption in Dwarka, one of the most sacred destination in Hindu imagination. He also attempted to transpose the piety of Dwarka and recreate a parallel religious experience at Vadtal, an important site in Swaminarayan Hinduism. This process of making sacred sites more egalitarian is classified here as a 'religious reform'. The paper assesses this bivalent pursuit as an institutional reform within religion as well as a religious process in the context of piety, authority and orthodoxy. Through the example of Sahajanand Swami, it is argued to calibrate the colonial paradigm of reform that was largely contextual to social issues and western thought and failed to appreciate the religious reforms of that era. By constructing a nuanced typology of 'religious reform' distinct from 'social reforms', the paper eventually calls for a reassessment of religious figures who have significantly contributed in reforming the Hindu tradition in the medieval and modern era

    Phenolic, polysaccharidic and lipidic fractions of mushrooms from northeast Portugal: chemical compounds with antioxidant properties

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    Mushrooms do not constitute a significant portion of the human diet, but their consumption continues to increase due to their functional benefits and presence of bioactive compounds. Some of those compounds can be found in the phenolic, polysaccharidic and lipidic fractions of edible and inedible species. Herein, those fractions of five wild mushrooms (Coprinopsis atramentaria, Lactarius bertillonii, Lactarius vellereus, Rhodotus palmatus and Xerocomus chrysenteron) from Northeast Portugal were studied for their chemical composition and antioxidant properties. Protocatechuic, p-hydroxybenzoic, p-coumaric and cinnamic acids were found in the phenolic fraction, ramnose, xylose, fucose, arabinose, fructose, glucose, manose, mannitol, sucrose, maltose and trehalose were quantified in polysaccharidic fraction, linoleic and stearic (only in Lactarius sp.) acids, and β- and γ-tocopherols were the main compounds in the lipidic fraction. C. atramentaria and X. chrysenteron phenolic fractions gave the highest free radical scavenging activity, reducing properties and lipid peroxidation inhibition in brain homogenates, which is in agreement with its highest content in total phenolics. Furthermore, among the polysaccharidic fractions C. atramentaria also gave the highest antioxidant activity, which is accordingly with its highest total polysaccharides content and sugars obtained after hydrolysis.The authors are grateful to Fundação para a Ciência e a Tecnologia (FCT, Portugal) and COMPETE/QREN/EU (research project PTDC/AGR-ALI/110062/2009) for financial support. L. Barros (BPD/4609/2008) and S.A. Heleno (BD/70304/2010) also thank FCT, POPH-QREN and FSE. The GIP-USAL is financially supported by the Spanish Ministerio de Ciencia e Innovación through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063), and Junta de Castilla y León (Grupo de Investigación de Excelencia, GR133)
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