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The turbulent Prandtl number has been calculated in the two-loop approximation of the epsilon expansion of the stochastic theory of turbulence. The strikingly small value obtained for the two-loop correction explains the good agreement of the earlier one-loop result with the experiment. This situation is drastically different from other available nontrivial two-loop results, which exhibit corrections of the magnitude of the one-loop term. The reason is traced to the mutual cancellation of additional divergences appearing in two dimensions, which have had a major effect on the results of previous calculations of other quantities.

The field theoretic renormalization group and operator-product expansion are applied to the model of a passive scalar quantity advected by a non-Gaussian velocity field with finite correlation time. The velocity is governed by the Navier-Stokes equation, subject to an external random stirring force with the correlation function proportional to delta(t- t')k(4-d-2epsilon). It is shown that the scalar field is intermittent already for small epsilon, its structure functions display anomalous scaling behavior, and the corresponding exponents can be systematically calculated as series in epsilon. The practical calculation is accomplished to order epsilon2 (two-loop approximation), including anisotropic sectors. As for the well-known Kraichnan rapid-change model, the anomalous scaling results from the existence in the model of composite fields (operators) with negative scaling dimensions, identified with the anomalous exponents. Thus the mechanism of the origin of anomalous scaling appears similar for the Gaussian model with zero correlation time and the non-Gaussian model with finite correlation time. It should be emphasized that, in contrast to Gaussian velocity ensembles with finite correlation time, the model and the perturbation theory discussed here are manifestly Galilean covariant. The relevance of these results for real passive advection and comparison with the Gaussian models and experiments are briefly discussed.

Toxic shock syndrome is one of the best understood of the systemic inflammatory response syndromes. The mechanisms of disease have been extensively studied; however, no therapies have been developed that can effectively reverse the syndrome once the inflammatory response has begun. Although toxic shock syndrome classically has been associated with tampon use, multiple other etiologies exist including postpartum toxic shock, which usually affects patients in the immediate weeks following delivery. We present a case of toxic shock in a woman 10 weeks postpartum and review the literature regarding both menstrual-related and nonmenstrual-related toxic shock.