Kontakt: K. Samwer/C. Heussinger

Kontakt: K.-H. Rehren

Acanthamoeba castellanii is a human pathogenic parasite that is wide-spread in our water reservoirs. It can, upon contact with the human eye, cause a severe keratitis. 90% of the patients with this painful disease are contact lens users, who got infected due to wrong contact lens care. Through small lesions of the outermost epithelial cell layer, the amoebae reach the cornea and start to destroy target cells by an extracellular killing mechanism. A crucial first step during this killing process is the adhesion between an Acanthamoeba and a target cell. This initial contact is supposed to be mediated by carbohydrates. Subsequently, intracellular granules move towards the contact site and release pore-forming molecules. These pore-forming molecules finally destroy the membrane of target cells. In our work we aim at understanding the biophysical processes involved in target-cell killing: we study the “killing kiss” between Acanthamoeba and target cells from their initial adhesion to intracellular transport processes and to target cell death. In particular, studying intracellular motion in Acanthamoeba is highly interesting, as Acanthamoebae are extremely motile, change their shape, and show fast intracellular motion. The final goal of our studies is to receive a comprehensive biophysical picture of Acanthamoeba pathogenicity.

Kontakt: Glormann

Phase field methods are widely used in modeling the dynamics and equilibrium properties of materials. Unfortunately, time marching the equations of motion generally requires keeping the time step below a fixed, lattice-dependent size in order to be numerically stable. Such stability-limited simulations are vastly less efficient than an accuracy-limited simulation could be, with a time step chosen by the natural time scale of the dynamics. I will review recent progress by Eyre and others in developing stable phase field methods. Then I will present a general approach for developing unconditionally stable steps (i.e. stable for any size time step) that consist of linear equations for the updated field. This allows for solution via fast Fourier transform, making the method simple and efficient. I will demonstrate the approach for the Allen-Cahn and Cahn-Hilliard equations, Swift-Hohenberg and phase field crystal models, an Ehrlich-Schwoebel type interface growth model, and the Ohta-Kawasaki model for block copolymers.

Kontakt: Marcus Müller

Kontakt: K.-H. Rehren

Kontakt: K.-H. Rehren

Kontakt: K.-H. Rehren

Kontakt: K.-H. Rehren

Kontakt: K.-H. Rehren