1,237 research outputs found

    China and the crisis : global power, domestic caution and local initiative

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    Even though the global crisis had a quick and dramatic impact on Chinese exports, the Chinese government responded with a range of policy responses that have helped maintain high rates of growth. This success has helped propel China to the centre of global politics, accelerating what many perceive to be a power shift from the West to China. But these gains were achieved by reversing policy in previous years designed to make a fundamental shift in China‟s mode of development, and have highlighted the problems associated with making such a transition. At the moment that many are looking at the Chinese "model" as a potential alternative to the Washington Consensus, one of the consequences of the crisis is to further question the long term efficacy of this "model" in China itself

    Correlated Persistent Tunneling Currents in Glasses

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    Low temperature properties of glasses are derived within a generalized tunneling model, considering the motion of charged particles on a closed path in a double-well potential. The presence of a magnetic induction field B violates the time reversal invariance due to the Aharonov-Bohm phase, and leads to flux periodic energy levels. At low temperature, this effect is shown to be strongly enhanced by dipole-dipole and elastic interactions between tunneling systems and becomes measurable. Thus, the recently observed strong sensitivity of the electric permittivity to weak magnetic fields can be explained. In addition, superimposed oscillations as a function of the magnetic field are predicted.Comment: 4 page

    New synchronization method for <i>Plasmodium falciparum</i>

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    &lt;b&gt;Background&lt;/b&gt;: Plasmodium falciparum is usually asynchronous during in vitro culture. Although various synchronization methods are available, they are not able to narrow the range of ages of parasites. A newly developed method is described that allows synchronization of parasites to produce cultures with an age range as low as 30 minutes. &lt;b&gt;Methods&lt;/b&gt;: Trophozoites and schizonts are enriched using Plasmion. The enriched late stage parasites are immobilized as a monolayer onto plastic Petri dishes using concanavalin A. Uninfected erythrocytes are placed onto the monolayer for a limited time period, during which time schizonts on the monolayer rupture and the released merozoites invade the fresh erythrocytes. The overlay is then taken off into a culture flask, resulting in a highly synchronized population of parasites. &lt;b&gt;Results&lt;/b&gt;: Plasmion treatment results in a 10- to 13-fold enrichment of late stage parasites. The monolayer method results in highly synchronized cultures of parasites where invasion has occurred within a very limited time window, which can be as low as 30 minutes. The method is simple, requiring no specialized equipment and relatively cheap reagents. &lt;b&gt;Conclusions&lt;/b&gt;: The new method for parasite synchronization results in highly synchronized populations of parasites, which will be useful for studies of the parasite asexual cell cycle

    The High Magnetic Field Phase Diagram of a Quasi-One Dimensional Metal

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    We present a unique high magnetic field phase of the quasi-one dimensional organic conductor (TMTSF)2_2ClO4_4. This phase, termed "Q-ClO4_4", is obtained by rapid thermal quenching to avoid ordering of the ClO4_4 anion. The magnetic field dependent phase of Q-ClO4_4 is distinctly different from that in the extensively studied annealed material. Q-ClO4_4 exhibits a spin density wave (SDW) transition at \approx 5 K which is strongly magnetic field dependent. This dependence is well described by the theoretical treatment of Bjelis and Maki. We show that Q-ClO4_4 provides a new B-T phase diagram in the hierarchy of low-dimensional organic metals (one-dimensional towards two-dimensional), and describe the temperature dependence of the of the quantum oscillations observed in the SDW phase.Comment: 10 pages, 4 figures, preprin

    Magic angle effects of the one-dimensional axis conductivity in quasi-one dimensional conductors

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    In quasi-one-dimensional conductors, the conductivity in both one-dimensional axis and interchain direction shows peaks when magnetic field is tilted at the magic angles in the plane perpendicular to the conducting chain. Although there are several theoretical studies to explain the magic angle effect, no satisfactory explanation, especially for the one-dimensional conductivity, has been obtained. We present a new theory of the magic angle effect in the one-dimensional conductivity by taking account of the momentum-dependence of the Fermi velocity, which should be large in the systems close to a spin density wave instability. The magic angle effect is explained in the semiclassical equations of motion, but neither the large corrugation of the Fermi surface due to long-range hoppings nor hot spots, where the relaxation time is small, on the Fermi surface are required.Comment: 4 pages, 3 figure

    Role of the dimerized gap due to anion ordering in spin-density wave phase of (TMTSF)2_2ClO4_4 at high magnetic fields

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    Magnetoresistance measurements have been carried out along the highly conducting a axis in the FISDW phase of hydrogened and deuterated (TMTSF)2_2ClO4_4 for various cooling rates through the anion ordering temperature. With increasing the cooling rate, a) the high field phase boundary βHI\beta_{\rm {HI}}, observed at 27 T in hydrogened samples for slowly cooled, is shifted towards a lower field, b) the last semimetallic SDW phase below βHI\beta_{\rm {HI}} is suppressed, and c) the FISDW insulating phase above βHI\beta_{\rm {HI}} is enhanced in both salts. The cooling rate dependence of the FISDW transition and of βHI\beta_{\rm {HI}} in both salts can be explained by taking into account the peculiar SDW nesting vector stabilized by the dimerized gap due to anion ordering.Comment: 6pages,6figures(EPS), accepted for publication in PR

    Strongly nonlinear magnetization above TcT_c in Bi2Sr2CaCu2O8+δ\rm Bi_2Sr_2CaCu_2O_{8+\delta}

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    Using high-resolution magnetometry we have investigated in detail the magnetization MM above the critical temperature TcT_c in Bi2Sr2CaCu2O8+δ\rm Bi_2Sr_2CaCu_2O_{8+\delta}. In a broad range of temperature TT above TcT_c, we find that M(T,H)M(T,H) is strongly non-linear in the field HH. We show that as TTcT\to T_c, the susceptibility χ(T,H)\chi(T,H) diverges to very large values (χ\chi \to -1) if measured in weak HH. In addition, M(H)M(H) displays an anomalous non-analytic form MH1/δM\sim H^{1/\delta} in weak fields with a strongly TT-dependent exponent δ(T)\delta(T). These features strongly support the proposal that, above TcT_c, the pair condensate survives to support significant London rigidity.Comment: 5 pages, 5 figure
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