48 research outputs found

    Spin glass overlap barriers in three and four dimensions

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    For the Edwards-Anderson Ising spin-glass model in three and four dimensions (3d and 4d) we have performed high statistics Monte Carlo calculations of those free-energy barriers FBqF^q_B which are visible in the probability density PJ(q)P_J(q) of the Parisi overlap parameter qq. The calculations rely on the recently introduced multi-overlap algorithm. In both dimensions, within the limits of lattice sizes investigated, these barriers are found to be non-self-averaging and the same is true for the autocorrelation times of our algorithm. Further, we present evidence that barriers hidden in qq dominate the canonical autocorrelation times.Comment: 20 pages, Latex, 12 Postscript figures, revised version to appear in Phys. Rev.

    Prediction of pH Change in Processed Acidified Turnips

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    The acetic acid uptake by turnips was studied during an acidification process in containers. The process was successfully described by a Fickian diffusion, using a correlation for the buffer effect. Diffusion coefficients (0.629 to 3.99 × 10-9 m2/sec) and partition coefficients (0.8 to 1.1) were obtained by optimization of the fit between experimental and theoretical values, using the simplex method. The partition coefficient did not show an evident dependence on temperature, while diffusivity followed an Arrhenius type behavior. The relationship between acid concentration and pH was described using a cubic model with parameters independent of temperature. Results showed that the combination of these models describing the acid diffusion into the food and the buffering effects of the food allowed accurate prediction of pH evolution in the acidification process

    Effects of Intermittent IL-2 Alone or with Peri-Cycle Antiretroviral Therapy in Early HIV Infection: The STALWART Study

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    The Study of Aldesleukin with and without antiretroviral therapy (STALWART) evaluated whether intermittent interleukin-2 (IL-2) alone or with antiretroviral therapy (ART) around IL-2 cycles increased CD4+ counts compared to no therapy

    THE COURTS AND RISK ASSESSMENT -super-1

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    In the past decade the federal courts have come to play an important role in reviewing agency decision-making on prospective risks. Questioning the conventional wisdom that judges are poorly equipped for the task, the authors outline the range of choices facing courts in such cases and contend that they cannot avoid making ultimate decisions on risk policy. However, recent Supreme Court cases on nuclear hazards and occupational benzene indicate narrowing of the scope for judicial review. Copyright 1982 by The Policy Studies Organization.
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