Macroscopic transport in mixed phase space Hamiltonian systems and the role of a distinct time-scale for the power-law decay.

Motivated by the losses of runaway electrons during disruptive events in present and future tokamaks like the ITER, we investigate the transport in mixed phase space Hamiltonian systems. We are interested in the regime where the sticky regions, remaining after the disintegration of invariant transport barriers, form layers in the phase space separated by partial barriers to transport. The example we use is the standard map.

Fractals and Chaos in the Hemodynamics of Intracranial Aneurysms.

Computing the emerging flow in blood vessel sections by means of computational fluid dynamics is an often applied practice in hemodynamics research. One particular area for such investigations is related to the cerebral aneurysms, since their formation, pathogenesis, and the risk of a potential rupture may be flow-related. We present a study on the behavior of small advected particles in cerebral vessel sections in the presence of aneurysmal malformations.

Unrevealed part of myosin's powerstroke accounts for high efficiency of muscle contraction.

Background: Myosin II, the motor protein driving muscle contraction, uses energy of ATP hydrolysis to produce movement along actin. The key step of energy transduction is the powerstroke, involving rotation of myosin's lever while myosin is attached to actin. Macroscopic measurements indicated high thermodynamic efficiency for energy conversion.

Emerging fractal patterns in a real 3D cerebral aneurysm.

The behaviour of biological fluid flows is often investigated in medical practice to draw conclusions on the physiological or pathological conditions of the considered organs. One area where such investigations are proven to be useful is the flow-related formation and growth of different pathologic malformations of the cerebro-vascular system. In this work, a detailed study is presented on the effect of a cerebral aneurysm on blood transport inside a human brain artery segment.

Doubly transient chaos: generic form of chaos in autonomous dissipative systems.

Chaos is an inherently dynamical phenomenon traditionally studied for trajectories that are either permanently erratic or transiently influenced by permanently erratic ones lying on a set of measure zero. The latter gives rise to the final state sensitivity observed in connection with fractal basin boundaries in conservative scattering systems and driven dissipative systems. Here we focus on the most prevalent case of undriven dissipative systems, whose transient dynamics fall outside the scope of previous studies since no time-dependent solutions can exist for asymptotically long times.