| dc.description.abstract |
The aim of this study was to determine the minimum track length required forthe reliable calculation of the fractal dimension of trajectories ofcapacitating human spermatozoa. Manually reconstructed trajectories classifiedpreviously as hyperactivated or non-hyperactivated were re-analyzed. Thetrajectories were reconstructed at 60 Hz, and each comprised 61 points(corresponding to 1 s movement). The trajectories were ‘split’ togive the equivalent of 2 × 31 point, 3 × 21 point, 4 × 16point and 6 × 11 point track segments and the fractal dimensiondetermined for each. The fractal dimensions of each track segment within eachtrajectory were compared using paired t-tests. Nosignificant difference was observed between the fractal dimensions of tracksegments of equal length, irrespective of the motility pattern. However,significant differences in fractal dimension values were observed whensegments of different lengths were compared (P<0.01).For the non-hyperactivated tracks, the fractal dimension was consistentlybelow the hyperactivation threshold level for only the 31 point segments. Thehyperactivated tracks consistently had fractal dimension values above thethreshold level when segments of 16 points or longer were analysed. Therefore,the minimum track length for the determination of reliable fractal dimensionvalues was 31 points, corresponding to an image sampling time of 0.5 s at 60Hz, although it could be used as a screening method for the identification ofhyperactivated motility for track segments of greater than 11 points(corresponding to 0.17 s movement). |
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