2,369 research outputs found

    Struggling to a monumental triumph : Re-assessing the final stages of the smallpox eradication program in India, 1960-1980

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    The global smallpox program is generally presented as the brainchild of a handful of actors from the WHO headquarters in Geneva and at the agency's regional offices. This article attempts to present a more complex description of the drive to eradicate smallpox. Based on the example of India, a major focus of the campaign, it is argued that historians and public health officials should recognize the varying roles played by a much wider range of participants. Highlighting the significance of both Indian and international field officials, the author shows how bureaucrats and politicians at different levels of administration and society managed to strengthen—yet sometimes weaken—important program components. Centrally dictated strategies developed at WHO offices in Geneva and New Delhi, often in association with Indian federal authorities, were reinterpreted by many actors and sometimes changed beyond recognition

    The labour ward analgesic service at King Edward VIII Hospital, Durban

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    The provision of analgesic services to the labour ward at King Edward VIII Hospital was studied during a 1-week period. Of 249 patients, 113 (45%) received no analgesia whatsoever. Intramuscular pethidine was the commonest form of analgesia and was used in 97 patients (39%). Thirty-six patients (14%) received epidural analgesia and only 4 inhalational analgesia using nitrous oxide and oxygen (Entonox). A significant proportion of patients who received pethidine were given the drug between 1 and 3 hours before delivery, increasing the potential for opiate-related neonatal depression. Of the patients given opiate analgesia, 22 (23%) proceeded to caesarean section and could have been at increased risk of aspiration of gastric contents owing to delayed gastric emptying caused by the opiate. One hundred and eleven mothers (76%) who had an obstetric indication for epidural analgesia were denied it because of lack of medical staffing

    Structure of Abrikosov Vortices in SU(2) Lattice Gauge Theory

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    We calculate the electric flux and magnetic monopole current distribution in the presence of a static quark-antiquark pair for SU(2) lattice gauge theory in the maximal Abelian gauge. The current distribution confines the flux in a dual Abrikosov vortex whose core size is comparable to the flux penetration depth. The observed structure is described by a dual Ginzburg-Landau model.Comment: 15 pages, latex file, three figure postscript files appended, Report No. LSUHEP No. 138-199

    Geological dimension of the cultural heritage: A case example of the Ajanta Caves (Maharashtra, India)

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    [Abstract]International development for the both geoconservation and geotourism requires attention to all kinds of (potential) geological heritage. The Ajanta Caves (western Maharashtra, India) is a famous cultural object consisting of 30 caves carved in the Deccan Traps and inscribed to the UNESCO list of the World Heritage Sites. Its examination permits to indicate four geological features, which are the artificial caves themselves (these mark geological activity of the man in the historical past), the end-Cretaceous flood basalts (these demonstrate the emplacement of Large Igneous Province and the relevant palaeoenvironmental catastrophe), the gorge of the Waghora River (this is peculiar landform resulted from the river erosion of hard rocks), and the rockfall hazard (this is an interesting engineering geological phenomenon linked to the caves construction/maintenance). Geological heritage value of these features is argued. Unfortunately, there is not any geotourism activity at the Ajanta Caves presently. The content analysis of the principal on-line resources (web pages) devoted to this cultural site reveals the absence of sufficient geological information that would 68 Gontareva, E.F et al. CAD. LAB. XEOL. LAXE 38 (2015) facilitate geotourism. Generally, judgements about the Ajanta Caves and the other similar sites in the geological dimension permit to consider the wide spectrum of the geological heritage. They also highlight some extra opportunities for geotourism, which can benefit by its development at cultural sites with thousands of visitors

    Superconductivity and Electronic Structure of Perovskite MgCNi3

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    The electronic structure, stability, electron phonon coupling and superconductivity of the non-oxide perovskite MgCNi3_3 are studied using density functional calculations. The band structure is dominated by a Ni dd derived density of states peak just below the Fermi energy, which leads to a moderate Stoner enhancement, placing MgCNi3_3 in the range where spin fluctuations may noticeably affect transport, specific heat and superconductivity, providing a mechanism for reconciling various measures of the coupling λ\lambda. Strong electron phonon interactions are found for the octahedral rotation mode and may exist for other bond angle bending modes. The Fermi surface contains nearly cancelling hole and electron sheets that give unusual behavior of transport quantities particularly the thermopower. The results are discussed in relation to the superconductivity of MgCNi3_3.Comment: 4 pages, RevTex, 5 ps figure

    Confining string and P-vortices in the indirect Z(2) projection of SU(2) lattice gauge theory

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    We study the distribution of P-vortices near the confining string in the indirect Z(2) projection of SU(2) lattice gauge theory. It occurs that the density of vortices is constant at large distances and strongly suppressed near the line connecting the test quark-antiquark pair. This means that the condensate of P-vortices is broken inside the confining string. We also find that the width of the P-vortex density distribution is proportional to the logarithm of the distance between the quark and antiquark.Comment: 3 pages, 4 figures, Lattice2002(topology), 2 references added, minor change

    Critical exponents in Ising spin glasses

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    We determine accurate values of ordering temperatures and critical exponents for Ising Spin Glass transitions in dimension 4, using a combination of finite size scaling and non-equilibrium scaling techniques. We find that the exponents η\eta and zz vary with the form of the interaction distribution, indicating non-universality at Ising spin glass transitions. These results confirm conclusions drawn from numerical data for dimension 3.Comment: 6 pages, RevTeX (or Latex, etc), 10 figures, Submitted to PR

    Effects of C, Cu and Be substitutions in superconducting MgB2

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    Density functional calculations are used to investigate the effects of partial substitutional alloying of the B site in MgB2 with C and Be alone and combined with alloying of the Mg site with Cu. The effect of such substitutions on the electronic structure, electron phonon coupling and superconductivity are discussed. We find that Be substitution for B is unfavorable for superconductivity as it leads to a softer lattice and weaker electron-phonon couplings. Replacement of Mg by Cu leads to an increase in the stiffness and doping level at the same time, while the carrier concentration can be controlled by partial replacement of B by C. We estimate that with full replacement of Mg by Cu and fractional substitution of B by C, Tc values of 50K may be attainable.Comment: 5 pages, 4 figure

    Phase diagram for a class of spin-half Heisenberg models interpolating between the square-lattice, the triangular-lattice and the linear chain limits

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    We study the spin-half Heisenberg models on an anisotropic two-dimensional lattice which interpolates between the square-lattice at one end, a set of decoupled spin-chains on the other end, and the triangular-lattice Heisenberg model in between. By series expansions around two different dimer ground states and around various commensurate and incommensurate magnetically ordered states, we establish the phase diagram for this model of a frustrated antiferromagnet. We find a particularly rich phase diagram due to the interplay of magnetic frustration, quantum fluctuations and varying dimensionality. There is a large region of the usual 2-sublattice Ne\'el phase, a 3-sublattice phase for the triangular-lattice model, a region of incommensurate magnetic order around the triangular-lattice model, and regions in parameter space where there is no magnetic order. We find that the incommensurate ordering wavevector is in general altered from its classical value by quantum fluctuations. The regime of weakly coupled chains is particularly interesting and appears to be nearly critical.Comment: RevTeX, 15 figure

    SrCu_2(BO_3)_2 - a Two Dimensional Spin Liquid

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    We study an extended Shastry-Sutherland model for SrCu_2(BO_3)_2 and analyze the low lying parts of the energy spectrum by means of a perturbative unitary transformation based on flow equations. The derivation of the 1-magnon dispersion (elementary triplets) is discussed. Additionally, we give a quantitative description (symmetries and energies) of bound states made from two elementary triplets. Our high order results allow to fix the model parameters for SrCu_2(BO_3)_2 precisely: J_1=6.16(10)meV, x:=J_2/J_1=0.603(3), J_\perp=1.3(2)meV. To our knowledge this is the first quantitative treatment of bound states in a true 2d model.Comment: 4 pages, 3 figures, Proceeding paper of the HFM2000 conference in Waterloo, Canada, Jun 200
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