Premium
FOURIER ANALYSIS OF ANGULAR DISTRIBUTIONS FOR MOTILE MICROORGANISMS
Author(s) -
Hauder DonatP.,
Lipson Edward D.
Publication year - 1986
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.1986.tb04722.x
Subject(s) - fourier transform , amplitude , fourier analysis , histogram , frequency domain , euglena gracilis , chromatic scale , flagellate , optics , biological system , physics , mathematics , mathematical analysis , biology , computer science , artificial intelligence , biochemistry , botany , chloroplast , image (mathematics) , gene
The method of Fourier transformation is used to analyze histograms of the angular distribution of organisms moving with respect to a stimulus, in this case the light direction. In the Fourier spectra, the components with the highest amplitudes indicate the modality of orientation, i.e. the number of preferred directions, and the corresponding phase values indicate the deviation from the light direction. In the frequency domain, those components with high amplitude and/or those with low frequencies (low‐pass filtering) can be selected and used to reconstruct a smoothed histogram by means of an inverse Fourier transform. This method reduces the noise level and reveals the prominent features of histograms. Examples of unimodal, bimodal and multimodal distributions are shown in their original and smoothed form for the flagellate Euglena gracilis , and for amoebae and pseudoplasmodia or the slime mold Dictyostelium discoideum.