Nonlinear temperature effects on multifractal complexity of metabolic rate of mice

PeerJ

article

Fabio A. Labra¹  Jose M. Bogdanovich²  Francisco Bozinovic³ 

[1] Facultad de Ciencias, Universidad Santo Tomás;Centro de Investigación e Innovación para el Cambio Climático, Universidad Santo Tomás;Departamento de Ecología, Center of Applied Ecology & Sustainability ,(CAPES) and LINC-Global, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile

关键词: Physiological complexity;    Metabolic rate fluctuations;    Endothermy;    Mus musculus;    Long-range correlations;    Multifractality;    Metabolic rate;   

DOI  :  10.7717/peerj.2607

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Complex physiological dynamics have been argued to be a signature of healthy physiological function. Here we test whether the complexity of metabolic rate fluctuations in small endotherms decreases with lower environmental temperatures. To do so, we examine the multifractal temporal scaling properties of the rate of change in oxygen consumption r(VO2), in the laboratory mouse Mus musculus, assessing their long range correlation properties across seven different environmental temperatures, ranging from 0 °C to 30 °C. To do so, we applied multifractal detrended fluctuation analysis (MF-DFA), finding that r(VO2) fluctuations show two scaling regimes. For small time scales below the crossover time (approximately 102 s), either monofractal or weak multifractal dynamics are observed depending on whether Ta < 15 °C or Ta 15 °C respectively. For larger time scales, r(VO2) fluctuations are characterized by an asymptotic scaling exponent that indicates multifractal anti-persistent or uncorrelated dynamics. For both scaling regimes, a generalization of the multiplicative cascade model provides very good fits for the Renyi exponents τ(q), showing that the infinite number of exponents h(q) can be described by only two independent parameters, a and b. We also show that the long-range correlation structure of r(VO2) time series differs from randomly shuffled series, and may not be explained as an artifact of stochastic sampling of a linear frequency spectrum. These results show that metabolic rate dynamics in a well studied micro-endotherm are consistent with a highly non-linear feedback control system.

【 授权许可】

CC BY