Genetically-modified parasite trajectories.

<p>a) Typical raw trajectory of a genetically-modified epimastigote (the trajectory initial point is indicated by means of a black dot) and b) the same trajectory after being smoothed by means of a moving average of length 5. The beginning of persistent-motion and tumbling segments are respectively indicated with green and red triangles. In c) and d), the power spectra of the angular changes of direction computed from the trajectories in a) and b), respectively.