1,522 research outputs found

    Municipal commonage and implications for land reform: A profile of commonage users in Philippolis, Free State, South Africa

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    This paper reports on a survey of municipal commonage users, which was undertaken in Philippolis in the southern Free State, in May 2005. The survey showed that a significant number of commonage users are committed to their farming enterprises, as shown by five proxy indicators: Their readiness to plough their income into their farming enterprises; their sale of livestock; their desire for more land, and their willingness to pay rental to secure such land; their desire to farm on their own; and their desire to own their own land. The paper reflects on the significance of commonage in the context of the South African government’s land reform policy, and argues that commonage can transcend survivalist or subsistence production, and can be used as a “stepping stone” for emergent farmers to access their own land parcels. Finally, the paper argues that, if commonage is to become a key part in a “step-up” strategy of land reform, then appropriately sized land parcels should be made available for commonage users, to enable them to “exit” from commonage use and invest in smallholdings or small farms.Land Economics/Use,

    Type 0 T-Duality and the Tachyon Coupling

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    We consider the T-duality relations between Type 0A and 0B theories, and show that this constraints the possible couplings of the tachyon to the RR-fields. Due to the `doubling' of the RR sector in Type 0 theories, we are able to introduce a democratic formulation for the Type 0 effective actions, in which there is no Chern-Simons term in the effective action. Finally we discuss how to embed Type II solutions into Type 0 theories.Comment: some misprints corrected and a reference adde

    On the fermionic T-duality of the AdS_4 \times CP^3 sigma-model

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    In this note we consider a fermionic T-duality of the coset realization of the type IIA sigma-model on AdS_4 \times CP^3 with respect to the three flat directions in AdS_4, six of the fermionic coordinates and three of the CP^3 directions. We show that the Buscher procedure fails as it leads to a singular transformation and discuss the result and its implications.Comment: LaTeX2e, 9 pages, no figures, JHEP style; v2: minor clarifications; v3: typos fixed, matches the published versio

    D5D5-brane type I superstring background fields in terms of type IIB ones by canonical method and T-duality approach

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    We consider type IIB superstring theory with embedded D5D5-brane and choose boundary conditions which preserve half of the initial supersymmetry. In the canonical approach that we use, boundary conditions are treated as canonical constraints. The effective theory, obtained from the initial one on the solution of boundary conditions, has the form of the type I superstring theory with embedded D5D5-brane. We obtain the expressions for D5D5-brane background fields of type I theory in terms of the D5D5-brane background fields of type IIB theory. We show that beside known Ω\Omega even fields, they contain squares of Ω\Omega odd ones, where Ω\Omega is world-sheet parity transformation, Ω:σ→−σ\Omega:\sigma\to -\sigma. We relate result of this paper and the results of [1] using T-dualities along four directions orthogonal to D5D5-brane

    Corporal diagnostic work and diagnostic spaces: Clinicians' use of space and bodies during diagnosis

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    © 2015 The Authors. Sociology of Health & Illness © 2015 Foundation for the Sociology of Health & Illness/John Wiley & Sons Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.An emerging body of literature in sociology has demonstrated that diagnosis is a useful focal point for understanding the social dimensions of health and illness. This article contributes to this work by drawing attention to the relationship between diagnostic spaces and the way in which clinicians use their own bodies during the diagnostic process. As a case study, we draw upon fieldwork conducted with a multidisciplinary clinical team providing deep brain stimulation (DBS) to treat children with a movement disorder called dystonia. Interviews were conducted with team members and diagnostic examinations were observed. We illustrate that clinicians use communicative body work and verbal communication to transform a material terrain into diagnostic space, and we illustrate how this diagnostic space configures forms of embodied 'sensing-and-acting' within. We argue that a 'diagnosis' can be conceptualised as emerging from an interaction in which space, the clinician-body, and the patient-body (or body-part) mutually configure one another. By conceptualising diagnosis in this way, this article draws attention to the corporal bases of diagnostic power and counters Cartesian-like accounts of clinical work in which the patient-body is objectified by a disembodied medical discourse.The Wellcome Trust (Wellcome Trust Biomedical Strategic Award 086034

    Syrian Refugees and the Digital Passage to Europe: Smartphone Infrastructures and Affordances

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    This research examines the role of smartphones in refugees’ journeys. It traces the risks and possibilities afforded by smartphones for facilitating information, communication, and migration flows in the digital passage to Europe. For the Syrian and Iraqi refugee respondents in this France-based qualitative study, smartphones are lifelines, as important as water and food. They afford the planning, navigation, and documentation of journeys, enabling regular contact with family, friends, smugglers, and those who help them. However, refugees are simultaneously exposed to new forms of exploitation and surveillance with smartphones as migrations are financialised by smugglers and criminalized by European policies, and the digital passage is dependent on a contingent range of sociotechnical and material assemblages. Through an infrastructural lens, we capture the dialectical dynamics of opportunity and vulnerability, and the forms of resilience and solidarity, that arise as forced migration and digital connectivity coincide

    Generalized Kahler Geometry from supersymmetric sigma models

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    We give a physical derivation of generalized Kahler geometry. Starting from a supersymmetric nonlinear sigma model, we rederive and explain the results of Gualtieri regarding the equivalence between generalized Kahler geometry and the bi-hermitean geometry of Gates-Hull-Rocek. When cast in the language of supersymmetric sigma models, this relation maps precisely to that between the Lagrangian and the Hamiltonian formalisms. We also discuss topological twist in this context.Comment: 18 page

    Background independent action for double field theory

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    Double field theory describes a massless subsector of closed string theory with both momentum and winding excitations. The gauge algebra is governed by the Courant bracket in certain subsectors of this double field theory. We construct the associated nonlinear background-independent action that is T-duality invariant and realizes the Courant gauge algebra. The action is the sum of a standard action for gravity, antisymmetric tensor, and dilaton fields written with ordinary derivatives, a similar action for dual fields with dual derivatives, and a mixed term that is needed for gauge invariance.Comment: 45 pages, v2: minor corrections, refs. added, to appear in JHE

    Two-Vierbein Formalism for String-Inspired Axionic Gravity

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    Using independent left and right vierbeins to describe graviton plus axion as suggested by string mechanics, O(d,d) duality can be realized linearly.Comment: 14 pg., (uuencoded dvi file; fixed uuencoding so file is unprotected) ITP-SB-93-

    Exact Models of Extremal Dyonic 4D Black Hole Solutions of Heterotic String Theory

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    Families of exact (0,2)(0,2) supersymmetric conformal field theories of magnetically and electrically charged extremal 4D black hole solutions of heterotic string theory are presented. They are constructed using a (0,1)(0,1) supersymmetric SL(2,R)×SU(2)SL(2,R)\times SU(2) WZW model where anomalously embedded U(1)×U(1)U(1)\times U(1) subgroups are gauged. Crucial cancelations of the U(1)U(1) anomalies coming from the supersymmetric fermions, the current algebra fermions and the gauging ensure that there is a consistency of these models at the quantum level. Various 2D models, which may be considered as building blocks for extremal 4D constructions, are presented. They generalise the class of 2D models which might be obtained from gauging SL(2,R)SL(2,R) and coincide with known heterotic string backgrounds. The exact conformal field theory presented by Giddings, Polchinski and Strominger describing the angular sector of the extremal magnetically charged black hole is a special case of this construction. An example where the radial and angular theories are mixed non--trivially is studied in detail, resulting in an extremal dilatonic Taub--NUT--like dyon.Comment: 42 pages (Plain TEX), IASSNS-HEP-94/20 (Revised version has minor corrections, references and a note added and is now identical to published version in Phys Rev D.
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