Modelling the lithospheric rheology control on Cretaceous rifting in West Antarctica.

Small-scale analogue models were used to investigate the process of Cretaceous orthogonal extension in the West Antarctic Rift System. The models considered the transition from the East Antarctic Craton to a weaker lithosphere, and the results support previous hypotheses about the strong control exerted by lateral variations in lithospheric structures on the process of extension. Strain was mostly accommodated at the boundary between the two types of lithosphere, with a relative uplift of the cratonic block which remained essentially undeformed. Conversely, the weaker lithosphere showed wide-rifting style geometry, locally associated with core complex-like structures. In agreement with the natural prototype, this tectonic scenario led to a long-lasting extension without continental break-up, and to the absence of relevant surface magmatism. © 2007 Blackwell Publishing Ltd

Propafenone for the prevention of atrial tachyarrhythmias after cardiac surgery: a randomized, double-blind placebo-controlled trial

We studied the efficacy of propafenone in preventing atrial tachyarrhythmias after cardiac surgery, and the possible relationships between CYP2D6 polymorphism and the efficacy, pharmacokinetics, and tolerability of propafenone. One hundred and sixty patients were randomized (double blind) to receive propafenone (n= 78) or placebo (n= 82) for 1 week after cardiac surgery. The patients who were assigned to the propafenone group received 1 mg/kg infused in 1 h, followed by a continuous infusion at a rate of 4 mg/kg/24 h until the following morning, and subsequently 450 mg/day orally until the sixth postoperative day. Thirty-seven patients completed the trial in the propafenone group and 45 in the placebo group. The frequency of occurrence of atrial tachyarrhythmia was lower in the propafenone group than in the placebo group (29.7% vs. 53.3% , P< 0.05; relative risk, 0.56). Plasma propafenone concentrations were markedly influenced by CYP2D6 genotype-derived phenotype.K Mörike...M Eichelbaum...et al