TY - THES T1 - Stochastic modeling of active biological transport in inhomogeneous environments A1 - Greulich,Philip Y1 - 2010/04/09 N2 - This thesis considers systems of actively driven particles on biased tracks in inhomogeneous environments. One example is vehicular- and pedestrian traffic. The main focus of this work, however, is on modeling collective directed motion of molecular motors involved in protein production or the transport of cargo on intracellular filaments. Transport on inhomogeneous tracks exhibits a jamming transition that emerges if the particle current attains the transport capacity of a bottleneck, which marks the maximum current. Jamming can be observed in traffic, but also for molecular motors. An analytical scheme to predict the transport capacity and critical parameters of this transition is developed. The presented models apply to tracks with slow sites (defects). These can for example be induced by biomedical drugs. In the context of intracellular traffic, defects are presently discussed as a cause of several diseases, e.g. Alzheimer's disease. Particular codons on mRNA can also slow down ribosomes. Furthermore, transport on (filament-) networks is investigated. It is shown that particle clusters emerge. In contrast to regular networks or diffusion limited (reversible) aggregation, inhomogeneous networks exhibit a scale-free distribution of cluster sizes. This result can help to distinguish microscopic dynamics and structures by analyzing macroscopic particle cluster patterns. Applied to clusters of membrane proteins that promote the internalization of toxins, an analysis of clusters might improve the understanding of toxic pathways. KW - Stofftransport KW - Statistische Physik KW - Unordnung KW - Mathematische Modellierung KW - Netzwerk CY - Saarbrücken PB - Universitäts- und Landesbibliothek AD - Postfach 151141, 66041 Saarbrücken UR - http://scidok.sulb.uni-saarland.de/volltexte/2010/2998 ER -