Variability of the drift velocity with the cell body size.

<p>(a) Histograms showing the distribution of flick angles with various body lengths (data from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0190434#pone.0190434.ref017" target="_blank">17</a>]). Red histogram represents all measured flick angles—170 events for 20 cells with various body lengths. Flick angles for four particular values of cellular body lengths are shown by narrow color histograms (<i>l</i> = 3.45 <i>μ</i>m, orange; <i>l</i> = 2.31 <i>μ</i>m, yellow; <i>l</i> = 1.72 <i>μ</i>m, green; <i>l</i> = 1.35 <i>μ</i>m, cyan histogram). The data obtained for 20 individuals (each of which is displayed at least 6 flicks in their trajectory) are shown as red points. Small blue ticks show the mean flick angles obtained from individual distributions. Black tick labels of the vertical axis correspond to the histograms of individual cells, whereas the red tick labels correspond to the red histogram for all cells. (b) Analytically obtained drift speed calculated for the mean flick angle of the considered cells, as a function of the angle and the corresponding body length. For results the following parameters were used: |∇<i>c</i>| = 0.5 <i>μ</i>m⁻⁴, λ = 3.3 s⁻¹, <i>v</i>₀ = 45 <i>μ</i>ms⁻¹, <i>D</i>_<i>r</i> = 0.2 rad²s⁻¹, <i>W</i> = 0.0458 <i>μ</i>m³ and <i>β</i> = cos 172°.