title: Inference on periodicity of circadian time series.
abstract: Estimation of the period length of time-course data from cyclical biological processes, such as those driven by the circadian pacemaker, is crucial for inferring the properties of the biological clock found in many living organisms. We propose a methodology for period estimation based on spectrum resampling (SR) techniques. Simulation studies show that SR is superior and more robust to non-sinusoidal and noisy cycles than a currently used routine based on Fourier approximations. In addition, a simple fit to the oscillations using linear least squares is available, together with a non-parametric test for detecting changes in period length which allows for period estimates with different variances, as frequently encountered in practice. The proposed methods are motivated by and applied to various data examples from chronobiology.
authors.affiliation: Warwick Systems Biology Centre, University of Warwick, Coventry CV4 7AL, UK,. maria.x.costa@gsk.com.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Costa
authors.forename: Bärbel
authors.initials: B
authors.lastname: Finkenstädt
authors.forename: Véronique
authors.initials: V
authors.lastname: Roche
authors.forename: Francis
authors.initials: F
authors.lastname: Lévi
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gould
authors.forename: Julia
authors.initials: J
authors.lastname: Foreman
authors.forename: Karen
authors.initials: K
authors.lastname: Halliday
authors.forename: Anthony
authors.initials: A
authors.lastname: Hall
authors.forename: David A
authors.initials: DA
authors.lastname: Rand
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000254:growth & development; D001683:Biological Clocks / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D016500:Color Therapy / Q000379:methods; D015179:Colorectal Neoplasms / Q000188:drug therapy; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D006801:Humans; D008171:Lung Diseases / Q000188:drug therapy; D051379:Mice; D056950:Period Circadian Proteins / Q000627:therapeutic use; D012044:Regression Analysis; D012881:Skin Temperature / Q000187:drug effects
chemical_list: C421902:PER2 protein, human; D056950:Period Circadian Proteins
keywords: Circadian rhythms; Non-parametric testing; Period estimation; Resampling; Spectrum