Hugo Chavez and the Future of Venezuela

Steven Ellner, Department of Economic History, Universidad Central de Venezuela, and David Myers, Department of Political Science, Pennsylvania State University, talked about democracy in Venezuela and the Chavez movement. The accompanying audio files provide the complete recording and audience discussion of the talks given by the authors. Those who download the audio files must have their own software for playing and listening

A theoretical study of the role of spatial population structure in the evolution of parasite virulence

The rich theory of infectious disease modelling using the Susceptible–Infectious–Recovered (SIR) framework is mainly based on the assumption of a well-mixed population, under which evolutionary behaviours (typically derived using adaptive dynamics) are shown to depend critically on the qualitative features of a virulence-transmission trade-off. Spatial extensions of this work, using simulation studies, show multiple evolutionary outcomes, which strongly depend on trade-off shape and, additionally, the length scale of the infectious process. In this paper, we aim to shed analytical insight into the mechanisms underlying these spatial evolutionary outcomes. In particular, why there is a qualitative difference observed in the evolutionary predicted virulence rates between linear and decelerating trade-offs between transmission and virulence and how recovery can weaken the effect of space. We use both pair approximations and cellular automata to model the spatial populations and the analysis exploits small neighbourhood variations in the spatial settings. The evolutionary outcomes are derived using adaptive dynamics

A randomized, double-blind, placebo-controlled trial of the use of prednisolone as an adjunct to treatment in HIV-1-associated pleural tuberculosis.

BACKGROUND: Active tuberculosis may accelerate progression of human immunodeficiency virus (HIV) infection by promoting viral replication in activated lymphocytes. Glucocorticoids are used in pleural tuberculosis to reduce inflammation-induced pathology, and their use also might reduce progression of HIV by suppressing immune activation. We examined the effect that prednisolone has on survival in HIV-1-associated pleural tuberculosis. METHODS: We conducted a randomized, double-blind, placebo-controlled trial of prednisolone as an adjunct to tuberculosis treatment, in adults with HIV-1-associated pleural tuberculosis. The primary outcome was death. Analysis was by intention to treat. RESULTS: Of 197 participants, 99 were assigned to the prednisolone group and 98 to the placebo group. The mortality rate was 21 deaths/100 person-years (pyr) in the prednisolone group and 25 deaths/100 pyr in the placebo group (age-, sex-, and initial CD4+ T cell count-adjusted mortality rate ratio, 0.99 [95% confidence interval, 0.62-1.56] [P =.95]). Resolution of tuberculosis was faster in the prednisolone group, but recurrence rates were slightly (though not significantly) higher, and use of prednisolone was associated with a significantly higher incidence of Kaposi sarcoma (4.2 cases/100 pyr, compared with 0 cases/100 pyr [P =.02]). CONCLUSIONS: In view of the lack of survival benefit and the increased risk of Kaposi sarcoma, the use of prednisolone in HIV-associated tuberculous pleurisy is not recommended