Professional Education

  • Diplom, Technische Universit├Ąt Berlin, Physics (2012)
  • Dr. rer. nat, Humboldt-Universit├Ąt zu Berlin, Theoretical Physics (2016)


All Publications

  • Chemokinetic Scattering, Trapping, and Avoidance of Active Brownian Particles PHYSICAL REVIEW LETTERS Kromer, J. A., de la Cruz, N., Friedrich, B. M. 2020; 124 (11)
  • Long-lasting desynchronization by decoupling stimulation PHYSICAL REVIEW RESEARCH Kromer, J. A., Tass, P. A. 2020; 2 (3)
  • Variability of collective dynamics in random tree networks of strongly coupled stochastic excitable elements PHYSICAL REVIEW E Khaledi-Nasab, A., Kromer, J. A., Schimansky-Geier, L., Neiman, A. B. 2018; 98 (5)
  • Decision making improves sperm chemotaxis in the presence of noise PLOS COMPUTATIONAL BIOLOGY Kromer, J. A., Maercker, S., Lange, S., Baier, C., Friedrich, B. M. 2018; 14 (4): e1006109


    To navigate their surroundings, cells rely on sensory input that is corrupted by noise. In cells performing chemotaxis, such noise arises from the stochastic binding of signalling molecules at low chemoattractant concentrations. We reveal a fundamental relationship between the speed of chemotactic steering and the strength of directional fluctuations that result from the amplification of noise in a chemical input signal. This relation implies a trade-off between steering that is slow and reliable, and steering that is fast but less reliable. We show that dynamic switching between these two modes of steering can substantially increase the probability to find a target, such as an egg to be found by sperm cells. This decision making confers no advantage in the absence of noise, but is beneficial when chemical signals are detectable, yet characterized by low signal-to-noise ratios. The latter applies at intermediate distances from a target, where signalling molecules are diluted, thus defining a 'noise zone' that cells have to cross. Our results explain decision making observed in recent experiments on sea urchin sperm chemotaxis. More generally, our theory demonstrates how decision making enables chemotactic agents to cope with high levels of noise in gradient sensing by dynamically adjusting the persistence length of a biased random walk.

    View details for DOI 10.1371/journal.pcbi.1006109

    View details for Web of Science ID 000432169600044

    View details for PubMedID 29672515

    View details for PubMedCentralID PMC5929576

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