Complex Orthogonal Decomposition Applied to Nematode Posturing

Abstract

The complex orthogonal decomposition (COD), a process of extracting complex modes from complex ensemble data, is summarized, as is the use of complex modal coordinates. A brief assessment is made on how small levels of noise affect the decomposition. The decomposition is applied to the posturing of Caenorhabditis elegans, an intensively studied nematode. The decomposition indicates that the worm has a multimodal posturing behavior, involving a dominant forward locomotion mode, a secondary, steering mode, and likely a mode for reverse motion. The locomotion mode is closer to a pure traveling waveform than the steering mode. The characteristic wavelength of the primary mode is estimated in the complex plane. The frequency is obtained from the complex modal coordinate's complex whirl rate of the complex modal coordinate, and from its fast Fourier transform. Short-time decompositions indicate the variation of the wavelength and frequency through the time record.

Neurobiology of Caenorhabditis elegans Locomotion: Where Do We Stand?

“… 2011 , Feeny et al. 2013 ). Moreover, the quantitative description of behavior arising from the building blocks spanning the space of observed body postures, termed eigenworms , provided a framework for unbiased scoring of previously undetectable phenotypes (Stephens et al.…”

Characterizing Wave Behavior in a Beam Experiment by Using Complex Orthogonal Decomposition

“…The interval of the strong nearly harmonic oscillation is then used to extract the modal coordinate temporal whirl rate, which represents the frequency of the mode. The mechanism for how experimental error leads to modal pollution was analyzed previously [23]. The extracted geometric dispersion relationship is shown in Fig.…”

“…The details of the COD algorithm are presented in the next section. Thus far COD has been applied to nematode posturing [23], whiting fish locomotion [24], and discerning traveling and standing modal waves [1]. COD has also been applied to extract the dispersion relation from a simulated beam [25].…”

Proprioceptive Sensing of Soft Tentacles with Model Based Reconstruction for Controller Optimization

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