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Dorilson Silva Cambui

Publications and source records attributed to Dorilson Silva Cambui.

3 recordsLinked to original sources

A Fibonacci-Based Ontogenetic Discretization of Body-Mass Growth Trajectories

Body-mass growth is usually described by continuous models that represent the gradual increase of mass toward an adult or asymptotic value. In this work, we formulate and test an alternative description based on a Fibonacci-inspired ontogenetic coordinate. The model represents growth through a continuous or discretized developmental index, allowing the trajectory to be organized into fine substages. The main analysis compares the Fibonacci-based model with the ontogenetic growth model of West, Brown, and Enquist using digitized growth data from four species with markedly different body sizes and developmental times. The Fibonacci-based formulation was favored in two of the four cases, while the WBE equation remained favored in the other two. A complementary analysis using rodent growth data showed that the Fibonacci discretized model can also approach the performance of classical continuous models in some datasets, although not uniformly. These results suggest that a Fibonacci-based ontogenetic coordinate can provide a useful alternative representation of body-mass growth within a biological systems framework.

physics.bio-ph↗

Metabolic rate beyond the 3/4 law

In earlier work, we introduced a discrete Fibonacci-based ontogenetic model in which the metabolic scaling exponent $b(n)$ is treated as a dynamic function of an organism's developmental stage, and we estimated $b(n)$ for selected mammalian species. In the present article, we revisit this framework with a complementary aim. Rather than proposing new parameter estimates or statistical fits, we provide a didactic, step-by-step reconstruction of the derivation that leads from the recursive growth hypothesis to analytical expressions for the stage-dependent exponent $b(n)$. Building directly on these previously obtained exponents, we then incorporate Kleiber's classical result into the model by interpreting the constant $70$ in the law $B \approx 70\,M^{3/4}$ (with $B$ denoting basal metabolic rate and $M$ body mass) as a metabolic "anchoring point". This yields a stage-dependent basal metabolic rate of the form $B(n) = 70\,M^{b(n)}$, which defines an ontogenetic metabolic trajectory linking recursive growth to changes in scaling. We show, at a conceptual level, how this anchored formulation can describe a shift from strongly sublinear behavior at early stages towards an almost linear regime as development proceeds, while still producing basal rates that are compatible, in order of magnitude, with those reported for mammals of different sizes. In this way, the paper offers a self-contained and pedagogical presentation of the model, emphasizing how ontogenetic changes in metabolic rate can be understood through the combined ideas of Fibonacci-like recursion and metabolic anchoring.

physics.bio-ph↗

Metabolic scaling from Fibonacci dynamics

We propose a discrete model to determine the metabolic scaling exponent based on Fibonacci growth patterns and discrete biological development phases. In contrast to continuous fractal models such as the West-Brown-Enquist (WBE) theory, the present approach describes metabolic scaling as the cumulative result of successive discrete stages, each incrementally contributing to metabolic activity. The scaling exponent b(n) emerges naturally from the logarithmic relationship between consecutive Fibonacci numbers, varying systematically with the organism's developmental stage. A refined logarithmic formulation significantly enhances quantitative agreement with empirical metabolic data across various mammalian species. This discrete framework effectively captures deviations from classical scaling laws, directly connecting recursive hierarchical structures with metabolic processes. Our model provides an alternative to traditional fractal transport approaches and can be naturally extended to hierarchical physical systems, opening new avenues to explore stage-dependent scaling phenomena in complex adaptive systems.

physics.bio-ph↗