47 research outputs found

    Studies on the synthesis of the toxins, pardaxin, δ-toxin and their analogues by solid-phase methods

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    Studies in our laboratory have been directed towards understanding the mechanism of action of two hydrophobic toxins, pardaxin comprising 33 residues and δ-toxin comprising 26 residues. Since isolation of these peptides in large amounts from natural sources is not convenient, we have explored synthetic approaches to get these peptides as well as their analogs. We have used chemistry specific to fluorenylmethoxycarbonyl (Fmoc) andt-butyloxycarbonyl (Boc) amino acids. Synthesis specific for Fmoc amino acids was carried out manually as well as on a semi-automated continuous flow peptide synthesizer. Synthesis specific for Boc amino acids was carried out manually. The protocols used by us have yielded 15-33 residue peptides which are of high purity. Even in peptides where heterogeneity was present, pure peptide could be obtained in good yields using simple gradients in fast performance liquid chromatography. The synthesis of pardaxin, δ-toxin and several analogs should help in identifying the molecular determinants of biological activity

    Justice at Sea: Fishers’ politics and marine conservation in coastal Odisha, India

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    This is a paper about the politics of fishing rights in and around the Gahirmatha marine sanctuary in coastal Odisha, in eastern India. Claims to the resources of this sanctuary are politicised through the creation of a particularly damaging narrative by influential Odiya environmental actors about Bengalis, as illegal immigrants who have hurt the ecosystem through their fishing practices. Anchored within a theoretical framework of justice as recognition, the paper considers the making of a regional Odiya environmentalism that is, potentially, deeply exclusionary. It details how an argument about ‘illegal Bengalis’ depriving ‘indigenous Odiyas’ of their legitimate ‘traditional fishing rights’ derives from particular notions of indigeneity and territory. But the paper also shows that such environmentalism is tenuous, and fits uneasily with the everyday social landscape of fishing in coastal Odisha. It concludes that a wider class conflict between small fishers and the state over a sanctuary sets the context in which questions about legitimate resource rights are raised, sometimes with important effects, like when out at sea

    On the functional overlap between complement and anti-microbial peptides

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    Intriguingly, activated complement and anti-microbial peptides share certain functionalities; lytic, phagocytic, and chemo-attractant activities and each may, in addition, exert cell instructive roles. Each has been shown to have distinct LPS detoxifying activity and may play a role in the development of endotoxin tolerance. In search of the origin of complement, a functional homolog of complement C₃ involved in opsonization has been identified in horseshoe crabs. Horseshoe crabs possess anti-microbial peptides able to bind to acyl chains or phosphate groups/saccharides of endotoxin, LPS. Complement activity as a whole is detectable in marine invertebrates. These are also a source of anti-microbial peptides with potential pharmaceutical applicability. Investigating the locality for the production of complement pathway proteins and their role in modulating cellular immune responses are emerging fields. The significance of local synthesis of complement components is becoming clearer from in vivo studies of parenchymatous disease involving specifically generated, complement-deficient mouse lines. Complement C₃ is a central component of complement activation. Its provision by cells of the myeloid lineage varies. Their effector functions in turn are increased in the presence of anti-microbial peptides. This may point to a potentiating range of activities, which should serve the maintenance of health but may also cause disease. Because of the therapeutic implications, this review will consider closely studies dealing with complement activation and anti-microbial peptide activity in acute inflammation (e.g., dialysis-related peritonitis, appendicitis, and ischemia)

    Making sense of the local state: rent-seeking, vernacular society and the employment assurance scheme in eastern India

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    This paper opens a window on the local state in eastern India. It studies the ways in which government officers in five districts of Bihar and West Bengal re-shaped one of India's major poverty alleviation programmes, the Employment Assurance Scheme (EAS). District and Block-level officials in Bihar converted a participatory programme of employment generation into a scheme for the construction of durable assets. Many poorer men and women obtained no work under the EAS. Outside Midnapore District, West Bengal, members of the rural poor were unaware of their right to demand work from the state. The acts of translation that we document were largely inspired by a fear of corruption on the part of junior officials. District and Block-level officials in Bihar worried that labour-intensive schemes would increase opportunities for rent-seeking and simple looting. That principals sought to constrain the actions of agents in this way suggests a weakness in the model of rent-seeking behaviour favoured by some economists. That the EAS was re-worked by well-educated, English-speaking government officials--and not by their subordinates--also suggests the need for refinement of a body of work on the 'vernacular' nature of the local state. No sharp distinction between elite and vernacular lifeworlds is evident in the field area
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