Figure 1.
<(Δz)2> and <(ΔR)2> versus z corrected for noise. The apparent z position is based on the observed average intensity between successive pairs of z or R measurements, with the corresponding Δz or ΔR placed in the appropriate uniformly spaced z bin. The brightest granule in the cell is used to define z = 0. Uncorrected values are straight averages of the (Δz)2 or (ΔR)2 in each bin. The corrected values take into account that part of the uncorrected values that arise from instrumental noise, as described in the Appendix. The gray band around the corrected values represent the ±2 × SE (i.e., 95% confidence) values, as calculated according to the Appendix. The uncorrected and corrected average R motions almost overlap. With the correction and the uncertainty band, one can see that the real motion both for Δz or ΔR is significant at all apparent z positions, it increases with z, and it is generally larger for R (the lateral direction) than for z (orthogonal to the substrate and presumably the membrane).