Christian Amann

Learn More
For a three-state Markov system in a stationary state, we discuss whether, on the basis of data obtained from effective two-state (or on-off) trajectories, it is possible to discriminate between an equilibrium state and a nonequilibrium steady state. By calculating the full phase diagram we identify a large region where such data will be consistent only(More)
The structure of the pyoverdin siderophore of Pseudomonas fluorescens 18.1 was elucidated by spectroscopic methods and chemical degradation. By cross feeding studies structurally closely related pyoverdins containing a C-terminal cyclopeptidic substructure were tested regarding the mutual recognition by the producing strains. Partial recognition of foreign(More)
We explore driven lattice gases for the existence of an intensive thermodynamic variable which could determine "equilibration" between two nonequilibrium steady-state systems kept in weak contact. In simulations, we find that these systems satisfy surprisingly simple thermodynamic laws, such as the zeroth law and the fluctuation-response relation between(More)
In this work, we address the problem of human pose estimation in still images by proposing a holistic model for learning the appearance of the human body from image patches. These patches, which are randomly chosen, are used for extracting features and training a regression forest. During training, a mapping between image features and human poses, defined(More)
A combination of confocal microscopy and rheology experiments, Brownian dynamics (BD) and molecular dynamics (MD) simulations and mode coupling theory (MCT) have been applied in order to investigate the effect of shear rate on the transient dynamics and stress-strain relations in supercooled and glassy systems under shear. Immediately after shear is(More)
Synopsis The stress vs strain curves in dense colloidal dispersions under start up shear flow are investigated combining experiments on model core shell microgels, computer simulations of hard disk mixtures, and mode coupling theory. In dense fluid and glassy states, the transient stresses exhibit first a linear increase with the accumulated strain, then a(More)
We demonstrate high-speed laser transmitters with relatively low-frequency devices using cascaded optical injection locking. Tailorable frequency response with a bandwidth of 52 GHz is obtained by adjusting locking parameters of the two slave lasers independently. Introduction Optical injection locking (OIL) is a very effective technique to increase the(More)
To execute system tests, two fundamentally different execution techniques exist: manual and automated execution. For each system test suite, one must decide how to employ those techniques (this strategy is called execution mode). Despite general conditions such as fixed testing strategies or development philosophies, almost all projects permit a wide range(More)
We employ x-ray scattering on sheared colloidal suspensions and mode coupling theory to study structure factor distortions of glass-forming systems under shear. We find a transition from quadrupolar elastic distortion at small strains to quadrupolar and hexadecupolar modes in the stationary state. The latter are interpreted as signatures of plastic(More)