Changes of the power coefficient in the 'metabolism-mass' relationship in the evolutionary process of animals.

Biosystems

Department of Biophysics, Faculty of Medicine, Thracian University, Stara Zagora 6000, Bulgaria.

Published: December 2002

The power coefficient k decreases along evolution in an allometric relationship between the oxygen consumption rate and the body mass of animals. This theoretical study investigated the role of the power coefficient k and its behavior along evolution. The animals were organized in three groups according to the values of the power coefficient k as follows: (I) from unicellular Prokaryotes to Eukaryotes; (II) from Mytilus and Annelida to Pisces; (III) from Reptilia to Mammals and Aves. At the beginning of each animal group (stage), the value of k was close to 0.9-1.0 and at the end of the stage it was close to 0.67-0.70. Exponential sharp increase of the power coefficient k was observed during the biological transition from Protozoa to simply organized Metazoa and in the transition from Poikylothermic to Homothermic organisms (e.g. from Pisces to Reptilia). Also, when using the periodogram regression analysis, a cyclic (periodic) pattern in this increase was observed (i.e. period T approximately 8-11 units, P<0.05). It was postulated that the power coefficient k, as with the coefficient a, might represent the increase of complexity of animal organization within each group.

Download full-text PDF

Source
http://dx.doi.org/10.1016/s0303-2647(02)00034-5DOI Listing

Publication Analysis

Top Keywords

power coefficient
20
stage close
8
coefficient
5
changes power
4
coefficient 'metabolism-mass'
4
'metabolism-mass' relationship
4
relationship evolutionary
4
evolutionary process
4
process animals
4
power
4

Similar Publications

The aim of the study was to determine the relationship between slaughter weight (SW) with body components and liner body measurements and investigate the coefficient of correlation between slaughter weight with body component and liner body measurements to select the best regression equation. Data on liner body measurements (height at wither and at hips, heart girth, body length, height and width of hump, height at fall and hind legs, body sheath height, height at hooks, barrel circumference, width of face, length of face and tail circumference) and slaughter weight of body components (Hot Carcass Weight (HCW), Empty Body Weight (ESW), Internal Offal (IO) and External Offal (EO)) were collected from 62 Hararghe cattle at Haramaya University abattoir. ESW was calculated as SW with less gut contents.

View Article and Find Full Text PDF

The use of winglet devices is an efficient technique for enhancing aerodynamic performance. This study investigates the effects of winglet cant angles on both the aerodynamics and aeroacoustics of a commercial wing, comparing them to other significant parameters using a parametric analysis. A Full Factorial Design method is employed to generate a matrix of experiments, facilitating a detailed exploration of flow physics, with lift-to-drag ratio (L/D) and the integral of Acoustic Power Level (APL) as the primary representatives of aerodynamic and acoustic performance, respectively.

View Article and Find Full Text PDF

Non-fused electron acceptors have obtained increasing curiosity in organic solar cells (OSCs) thanks to simple synthetic route and versatile chemical modification capabilities. However, non-fused acceptors with varying quinoxaline core and as-cast device have rarely been explored, and the molecular structure-photovoltaic performance relationship of such acceptors remains unclear. Herein, two non-fused acceptors L19 and L21 with thienyl substituted non-fluorinated/fluorinated quinoxaline core were developed via five-step synthesis.

View Article and Find Full Text PDF

Deep proximal gradient network for absorption coefficient recovery in photoacoustic tomography.

Phys Med Biol

January 2025

North China Electric Power University - Baoding Campus, North China Electric Power University, Baoding, Hebei Province, P.R.China, Baoding, Hebei, 071003, CHINA.

Objective: The optical absorption properties of biological tissues in photoacoustic tomography are typically quantified by inverting acoustic measurements. Conventional approaches to solving the inverse problem of forward optical models often involve iterative optimization. However, these methods are hindered by several challenges, including high computational demands, the need for regularization, and sensitivity to both the accuracy of the forward model and the completeness of the measurement data.

View Article and Find Full Text PDF

The MgSb-based layered compounds exhibit exceptional thermoelectric properties over a wide temperature range and possess the potential to supplant traditional BiTe modules with reliable and economical MgSb-based thermoelectric devices, contingent upon the availability of a complementary p-type MgSb material with high thermoelectric efficiency comparable to that of n-type MgSb. We provide a simpler method involving the codoping of monovalent atoms (K and Na) at the Mg site of the MgSb lattice to improve the thermoelectric performance of p-type MgSb. K-Na codoping results in a peak power factor of around 0.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!