@misc{AlonsoStangeBeta2018,
  author    = {Alonso, Sergio and Stange, Maike and Beta, Carsten},
  title     = {Modeling random crawling, membrane deformation and intracellular polarity of motile amoeboid cells},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch Naturwissenschaftliche Reihe},
  number    = {1014},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-45974},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-459745},
  pages     = {24},
  year      = {2018},
  abstract  = {Amoeboid movement is one of the most widespread forms of cell motility that plays a key role in numerous biological contexts. While many aspects of this process are well investigated, the large cell-to-cell variability in the motile characteristics of an otherwise uniform population remains an open question that was largely ignored by previous models. In this article, we present a mathematical model of amoeboid motility that combines noisy bistable kinetics with a dynamic phase field for the cell shape. To capture cell-to-cell variability, we introduce a single parameter for tuning the balance between polarity formation and intracellular noise. We compare numerical simulations of our model to experiments with the social amoeba Dictyostelium discoideum. Despite the simple structure of our model, we found close agreement with the experimental results for the center-of-mass motion as well as for the evolution of the cell shape and the overall intracellular patterns. We thus conjecture that the building blocks of our model capture essential features of amoeboid motility and may serve as a starting point for more detailed descriptions of cell motion in chemical gradients and confined environments.},
  language  = {en}
}
@misc{SeyrichAlirezaeizanjaniBetaetal.2018,
  author    = {Seyrich, Maximilian and Alirezaeizanjani, Zahra and Beta, Carsten and Stark, Holger},
  title     = {Statistical parameter inference of bacterial swimming strategies},
  series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {914},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-44621},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-446214},
  pages     = {23},
  year      = {2018},
  abstract  = {We provide a detailed stochastic description of the swimming motion of an E. coli bacterium in two dimension, where we resolve tumble events in time. For this purpose, we set up two Langevin equations for the orientation angle and speed dynamics. Calculating moments, distribution and autocorrelation functions from both Langevin equations and matching them to the same quantities determined from data recorded in experiments, we infer the swimming parameters of E. coli. They are the tumble rate lambda, the tumble time r(-1), the swimming speed v(0), the strength of speed fluctuations sigma, the relative height of speed jumps eta, the thermal value for the rotational diffusion coefficient D-0, and the enhanced rotational diffusivity during tumbling D-T. Conditioning the observables on the swimming direction relative to the gradient of a chemoattractant, we infer the chemotaxis strategies of E. coli. We confirm the classical strategy of a lower tumble rate for swimming up the gradient but also a smaller mean tumble angle (angle bias). The latter is realized by shorter tumbles as well as a slower diffusive reorientation. We also find that speed fluctuations are increased by about 30\% when swimming up the gradient compared to the reversed direction.},
  language  = {en}
}