title: Double-wavelet approach to studying the modulation properties of nonstationary multimode dynamics.
abstract: On the basis of double-wavelet analysis, the paper proposes a method to study interactions in the form of frequency and amplitude modulation in nonstationary multimode data series. Special emphasis is given to the problem of quantifying the strength of modulation for a fast signal by a coexisting slower dynamics and to its physiological interpretation. Application of the approach is demonstrated for a number of model systems, including a model that generates chaotic dynamics. The approach is then applied to proximal tubular pressure data from rat nephrons in order to estimate the degree to which the myogenic dynamics of the afferent arteriole is modulated by the slower tubulo-glomerular dynamics. Our analysis reveals a significantly stronger interaction between the two mechanisms in spontaneously hypertensive rats than in normotensive rats.
authors.affiliation: Department of Physics, The Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
authors.forename: O V
authors.initials: OV
authors.lastname: Sosnovtseva
authors.forename: A N
authors.initials: AN
authors.lastname: Pavlov
authors.forename: E
authors.initials: E
authors.lastname: Mosekilde
authors.forename: N-H
authors.initials: NH
authors.lastname: Holstein-Rathlou
authors.forename: D J
authors.initials: DJ
authors.lastname: Marsh
mesh_terms: D000465:Algorithms; D000818:Animals; D001683:Biological Clocks; D003198:Computer Simulation; D005246:Feedback; D006977:Hypertension, Renal / Q000503:physiopathology*; D008954:Models, Biological; D015233:Models, Statistical; D009399:Nephrons / Q000098:blood supply* / Q000503:physiopathology*; D011312:Pressure; D051381:Rats; D012079:Renal Circulation; D013269:Stochastic Processes