Experimental observation of resonance manifold shrinking under zonal flow shear.

In two-dimensional turbulent systems the redistribution of energy can be described by quadratic nonlinear three-wave interactions, which are limited by resonance conditions. The set of coupling modes can be understood as resonant manifold. It has been predicted by theory that, in the presence of a shear flow, the resonant manifold in wave-number space shrinks in time favoring large-scale structures.

Out of Africa by spontaneous migration waves.

Hominin evolution is characterized by progressive regional differentiation, as well as migration waves, leading to anatomically modern humans that are assumed to have emerged in Africa and spread over the whole world. Why or whether Africa was the source region of modern humans and what caused their spread remains subject of ongoing debate. We present a spatially explicit, stochastic numerical model that includes ongoing mutations, demic diffusion, assortative mating and migration waves.

The Radial Propagation of Heat in Strongly Driven Non-Equilibrium Fusion Plasmas.

Heat transport is studied in strongly heated fusion plasmas, far from thermodynamic equilibrium. The radial propagation of perturbations is studied using a technique based on the transfer entropy. Three different magnetic confinement devices are studied, and similar results are obtained.

Constructing criteria to diagnose the likelihood of extreme events in the case of the electric power grid.

A set of new criteria for the diagnosis of the possible occurrence of a large blackout are constructed, using the output from a model for the dynamics of the electric power grid (the OPA model). The approach used is to look for maximum values of the Transfer Entropy between time series of the system variables and the time series of large blackouts. The best criterion is found by looking at the number of overloaded lines at the beginning of the day.

Relevance of uncorrelated Lorentzian pulses for the interpretation of turbulence in the edge of magnetically confined toroidal plasmas.

Recently, it has been proposed that the turbulent fluctuations measured in a linear plasma device could be described as a superposition of uncorrelated Lorentzian pulses with a narrow distribution of durations, which would provide an explanation for the reported quasiexponential power spectra. Here, we study the applicability of this proposal to edge fluctuations in toroidal magnetic confinement fusion plasmas. For the purpose of this analysis, we introduce a novel wavelet-based pulse-detection technique that offers important advantages over existing techniques.