Management, Control, and the Dilemmas of Presidential Leadership in the Modern Administrative State

To assess the virtues of strong presidential leadership in the regulatory process, we need to have a richer sense of the dimensions of presidential leadership in regulatory decisionmaking. The set of proposals put forward by the National Performance Review (NPR), a task force established by the Clinton administration last year, provides a useful focal point for the examination of this issue. In Part I, the author considers how the trend toward President-led initiatives fits with our growing skepticism about the capacities of legislators and bureaucrats to improve regulation and administration. In Part II, the author traces some of the conceptual underpinnings of the President\u27s expanding regulatory role. The author adds to this mostly theoretical discussion the particulars of the NPR Report in Part III. Ultimately, the Clinton administration\u27s opening salvo into the thicket of regulatory reform is of a piece with contemporary trends in presidential politics and regulatory administration

Adding magnetic flux to the baryon vertex

We generalise the baryon vertex configuration of AdS/CFT by adding magnetic field on its worldvolume, dissolving D-string charge. A careful analysis of the configuration shows that there is an upper bound on the number of dissolved strings. We provide a microscopical description of this configuration in terms of a dielectric effect for the dissolved strings.Comment: 6 pages, 2 figures. Contribution to the proceedings of the RTN workshop in Napoli, Octobre 200

Computational probabilistic quantification of pro-arrhythmic risk from scar and left-to-right heterogeneity in the human ventricles

Both scar and left-to-right ventricular (LV/RV) differences in repolarization properties have been implicated as risk factors for lethal arrhythmias. As a possible mechanism for the initiation of re-entry, a recent study has indicated that LV/RV heterogeneities in action potential duration (APD) adaptation can cause a transient increase in APD dispersion following rate acceleration, promoting unidirectional block of conduction at the LV/RV junction. In the presence of an ischemic region and ectopic stimulation, a pathological dispersion in repolarization has been suggested to increase the risk of electrical re-entry. However, the exact location and timing of the ectopic activation play a crucial role in initiation of re-entry, and certain combinations may lead to re-entry even under normal LV/RV dispersion in repolarization. This suggests that the phenomenon needs to be investigated in a quantitative way. In this study we employ a computationally efficient, phenomenological model in order to investigate the proarrhythmic properties of a range of combinations of position and timing of an ectopic activation. This allows us to probabilistically study how increasing interventricular dispersion of repolarization increases arrhythmic risk. Results indicate that a larger LV/RV dispersion in repolarization allows ectopic beats to initiate re-entry during a significantly larger time window and from a greater number of locations compared to the case of smaller LV/RV dispersion