Additional file 4.Comparison between the frequency of light flicker in downward irradiance and two realistic estimates of F_{max}. F_{max} was estimated as either 10% (A,B) or 20% (C,D) of CFF. (A,C) The distribution of F_{max} values across frequency corresponded well to the power spectrum of flicker across depths. Note, however, that estimation of F_{max} as 20% of CFF resulted in F_{max} values that often exceeded the sampling frequency limit of light flicker. Depicted power spectrum (shaded gray) represents the envelope of flicker power across the 1 m and 10 m depth range. (B,D) Comparison between the cumulative power of the flicker and F_{max} for dim and bright stimuli (closed circles). Conventions for the indices of the distribution of power of flicker across frequencies (fP_{50}, fP_{90}, and fP_{99}), plot specifications, and species included in the analysis are the same as in Figure 3A,B. For estimation of F_{max} as 10% of CFF, the median F_{max} equaled 1.2 and 2.3 Hz, for dim and bright stimuli, respectively (open circle; red error bars represent the 25th and 75th percentiles). The median F_{max} for dim and bright stimuli matched the frequency below which approximately 50% of the cumulative power of flicker was found at 1 m depth. For estimation of F_{max} as 20% of CFF, the median F_{max} equaled 2.4 and 4.6 Hz, for dim and bright stimuli, respectively. The median F_{max} for dim and bright stimuli matched the frequency below which between 50% and 90% of the cumulative power of flicker was found at 1 m depth. For both F_{max} estimates, the median F_{max} for dim and bright stimuli matched the frequency below which 99% of the cumulative power at 10 m depth was found. Format: PDF Size: 250KB Download file This file can be viewed with: Adobe Acrobat Reader Sabbah and Hawryshyn BMC Biology 2013 11:77 doi:10.1186/1741-7007-11-77 |