207 research outputs found

    Cultures of caste and rural development in the social network of a south Indian village

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    Cultures of caste in much of rural India have become entangled with institutions of rural development. In community-driven development, emphasis on “local resource persons” and “community spokespersons” has created new opportunities for brokerage and patronage within some villages, which interact with existing forms of authority and community afforded by caste identity and intra-caste headmanship. In this article, we study how these entangled cultures of caste and development translate into social network structures using data on friendship ties from a south Indian village. We find that although caste continues to be important in shaping community structures and leadership in the village’s network, its influence varies across different communities. This fluidity of caste’s influence on community network structures is argued to be the result of multiple distinct yet partially overlapping cultural-political forces, which include sharedness afforded by caste identity and new forms of difference and inequality effected through rural development

    Actin cytoskeleton remodeling during early Drosophila furrow formation requires recycling endosomal components Nuclear-fallout and Rab11

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    Cytokinesis requires a dramatic remodeling of the cortical cytoskeleton as well as membrane addition. The Drosophila pericentrosomal protein, Nuclear-fallout (Nuf), provides a link between these two processes. In nuf-derived embryos, actin remodeling and membrane recruitment during the initial stages of metaphase and cellular furrow formation are disrupted. Nuf is a homologue of arfophilin-2, an ADP ribosylation factor effector that binds Rab11 and influences recycling endosome (RE) organization. Here, we show that Nuf is an important component of the RE, and that these phenotypes are a consequence of Nuf activities at the RE. Nuf exhibits extensive colocalization with Rab11, a key RE component. GST pull-downs and the presence of a conserved Rab11-binding domain in Nuf demonstrate that Nuf and Rab11 physically associate. In addition, Nuf and Rab11 are mutually required for their localization to the RE. Embryos with reduced levels of Rab11 produce membrane recruitment and actin remodeling defects strikingly similar to nuf-derived embryos. These analyses support a common role for Nuf and Rab11 at the RE in membrane trafficking and actin remodeling during the initial stages of furrow formation

    Motility Screen Identifies Drosophila IGF-II mRNA-Binding Protein—Zipcode-Binding Protein Acting in Oogenesis and Synaptogenesis

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    The localization of specific mRNAs can establish local protein gradients that generate and control the development of cellular asymmetries. While all evidence underscores the importance of the cytoskeleton in the transport and localization of RNAs, we have limited knowledge of how these events are regulated. Using a visual screen for motile proteins in a collection of GFP protein trap lines, we identified the Drosophila IGF-II mRNA-binding protein (Imp), an ortholog of Xenopus Vg1 RNA binding protein and chicken zipcode-binding protein. In Drosophila, Imp is part of a large, RNase-sensitive complex that is enriched in two polarized cell types, the developing oocyte and the neuron. Using time-lapse confocal microscopy, we establish that both dynein and kinesin contribute to the transport of GFP-Imp particles, and that regulation of transport in egg chambers appears to differ from that in neurons. In Drosophila, loss-of-function Imp mutations are zygotic lethal, and mutants die late as pharate adults. Imp has a function in Drosophila oogenesis that is not essential, as well as functions that are essential during embryogenesis and later development. Germline clones of Imp mutations do not block maternal mRNA localization or oocyte development, but overexpression of a specific Imp isoform disrupts dorsal/ventral polarity. We report here that loss-of-function Imp mutations, as well as Imp overexpression, can alter synaptic terminal growth. Our data show that Imp is transported to the neuromuscular junction, where it may modulate the translation of mRNA targets. In oocytes, where Imp function is not essential, we implicate a specific Imp domain in the establishment of dorsoventral polarity

    Rhesus TRIM5α disrupts the HIV-1 capsid at the inter-hexamer interfaces

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    TRIM proteins play important roles in the innate immune defense against retroviral infection, including human immunodeficiency virus type-1 (HIV-1). Rhesus macaque TRIM5α (TRIM5αrh) targets the HIV-1 capsid and blocks infection at an early post-entry stage, prior to reverse transcription. Studies have shown that binding of TRIM5α to the assembled capsid is essential for restriction and requires the coiled-coil and B30.2/SPRY domains, but the molecular mechanism of restriction is not fully understood. In this study, we investigated, by cryoEM combined with mutagenesis and chemical cross-linking, the direct interactions between HIV-1 capsid protein (CA) assemblies and purified TRIM5αrh containing coiled-coil and SPRY domains (CC-SPRYrh). Concentration-dependent binding of CC-SPRYrh to CA assemblies was observed, while under equivalent conditions the human protein did not bind. Importantly, CC-SPRYrh, but not its human counterpart, disrupted CA tubes in a non-random fashion, releasing fragments of protofilaments consisting of CA hexamers without dissociation into monomers. Furthermore, such structural destruction was prevented by inter-hexamer crosslinking using P207C/T216C mutant CA with disulfide bonds at the CTD-CTD trimer interface of capsid assemblies, but not by intra-hexamer crosslinking via A14C/E45C at the NTD-NTD interface. The same disruption effect by TRIM5αrh on the inter-hexamer interfaces also occurred with purified intact HIV-1 cores. These results provide insights concerning how TRIM5α disrupts the virion core and demonstrate that structural damage of the viral capsid by TRIM5α is likely one of the important components of the mechanism of TRIM5α-mediated HIV-1 restriction. © 2011 Zhao et al

    The Political Economy of Non-Traditional Security: Explaining the Governance of Avian Influenza in Indonesia

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    Given the common association of non-traditional security (NTS) problems with globalisation, surprisingly little attention has been paid to how the political economy context of given NTS issues shape how they are securitised and managed in practice. We argue that security and its governance are always highly contested because different modes of security governance invariably privilege particular interests and normative agendas in state and society, which relate directly to the political economy. Drawing on critical political geography, we argue that, because NTS issues are perceived as at least potentially transnational, their securitisation often involves strategic attempts by actors and coalitions to ‘rescale’ their governance beyond the national political and institutional arenas, into new, expert-dominated modes of governance. Such efforts are often resisted by other coalitions, for which this rescaling is deleterious. As evidenced by a case study of avian influenza in Indonesia, particular governance outcomes depend upon the nature of the coalitions assembled for and against rescaling in specific situations, while these coalitions’ make-up and relative strength is shaped by the political economy of the industries that rescaling would affect, viewed against the broader backdrop of state-society relations

    Relational persons and relational processes: developing the notion of relationality for the sociology of personal life

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    The concept of relationality has recently found widespread favour in British sociology, particularly in the emergent sub-field of the sociology of personal life, which is characterised by its attachment to the concept. However, this ‘relational turn’ is under-theorized and pays little attention to the substantial history of relational thinking across the human sciences. This paper argues that the notion of relationality in the sociology of personal life might be strengthened by an exploration of the conceptualization of the relational person and relational processes offered by three bodies of literature: the process oriented thinking of American pragmatism, specifically of Mead and Emirbayer; the figurational sociology of Elias; and psychoanalysis, particularly the object relations tradition, contemporary relational psychoanalysis and Ettinger’s notion of transubjectivity. The paper attends particularly to the processes involved in the individuality, agentic reflexivity and affective dimensions of the relational person

    HIV-1 gp41 Core with Exposed Membrane-Proximal External Region Inducing Broad HIV-1 Neutralizing Antibodies

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    The membrane-proximal external region (MPER) of the HIV-1 gp41 consists of epitopes for the broadly cross-neutralizing monoclonal antibodies 2F5 and 4E10. However, antigens containing the linear sequence of these epitopes are unable to elicit potent and broad neutralizing antibody responses in vaccinated hosts, possibly because of inappropriate conformation of these epitopes. Here we designed a recombinant antigen, designated NCM, which comprises the N- and C-terminal heptad repeats that can form a six-helix bundle (6HB) core and the MPER domain of gp41. Two mutations (T569A and I675V) previously reported to expose the neutralization epitopes were introduced into NCM to generate mutants named NCM(TA), NCM(IV), and NCM(TAIV). Our results showed that NCM and its mutants could react with antibodies specific for 6HB and MPER of gp41, suggesting that these antigens are in the form of a trimer of heterodimer (i.e., 6HB) with three exposed MPER tails. Antigen with double mutations, NCM(TAIV), elicited much stronger antibody response in rabbits than immunogens with single mutation, NCM(TA) and NCM(IV), or no mutation, NCM. The purified MPER-specific antibodies induced by NCM(TAIV) exhibited broad neutralizing activity, while the purified 6HB-specific antibodies showed no detectable neutralizing activity. Our recombinant antigen design supported by an investigation of its underlying molecular mechanisms provides a strong scientific platform for the discovery of a gp41 MPER-based AIDS vaccine

    Probing the Links between Political Economy and Non-Traditional Security: Themes, Approaches, and Instruments

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    This is a pre-print of an article published in International Politics. The definitive publisher-authenticated version of: Hameiri, Shahar, and Lee Jones. "Probing the links between political economy and non-traditional security: Themes, approaches and instruments." International Politics (2015), is available online at: http://dx.doi.org/10.1057/ip.2015.1In recent decades, the security agenda for states and international organisations has expanded dramatically to include a range of ‘non-traditional’, transnational security issues. It is often suggested that globalisation has been a key driver for the emergence or intensification of these problems, but, surprisingly, little sustained scholarly effort has been made to examine the link between responses to the new security agenda and the changing political economy. This curious neglect largely reflects the mutual blind-spots of the sub-disciplines of International Security Studies and International Political Economy, coupled with the dominance of approaches that tend to neglect economic factors. This special issue, which this article introduces, aims to overcome this significant gap. In particular, it focuses on three key themes: the broad relationship between security and the political economy; what is being secured in the name of security, and how this has changed; and how things are being secured – what modes of governance have emerged to manage security problems. In all of these areas, the contributions point to the crucial role of the state in translating shifting state-economy relations to new security definitions and practices
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