A universal power law and proportionate change process characterize the evolution of metabolic networks

2007 ◽  
Vol 57 (1) ◽  
pp. 75-80 ◽  
Author(s):  
S. Singh ◽  
A. Samal ◽  
V. Giri ◽  
S. Krishna ◽  
N. Raghuram ◽  
...  
Keyword(s):  
Power Law ◽  
Change Process ◽  
Metabolic Networks ◽  
Universal Power Law ◽  
Proportionate Change

scholarly journals Maximal modularity and the optimal size of parliaments

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Luca Gamberi ◽  
Yanik-Pascal Förster ◽  
Evan Tzanis ◽  
Alessia Annibale ◽  
Pierpaolo Vivo
Keyword(s):  
Power Law ◽  
Real World ◽  
Empirical Data ◽  
Random Network ◽  
Functional Relation ◽  
Optimal Size ◽  
Real World Data ◽  
Universal Power Law ◽  
The Empirical Analysis ◽  
Democratic Country

AbstractAn important question in representative democracies is how to determine the optimal parliament size of a given country. According to an old conjecture, known as the cubic root law, there is a fairly universal power-law relation, with an exponent equal to 1/3, between the size of an elected parliament and the country’s population. Empirical data in modern European countries support such universality but are consistent with a larger exponent. In this work, we analyse this intriguing regularity using tools from complex networks theory. We model the population of a democratic country as a random network, drawn from a growth model, where each node is assigned a constituency membership sampled from an available set of size D. We calculate analytically the modularity of the population and find that its functional relation with the number of constituencies is strongly non-monotonic, exhibiting a maximum that depends on the population size. The criterion of maximal modularity allows us to predict that the number of representatives should scale as a power-law in the size of the population, a finding that is qualitatively confirmed by the empirical analysis of real-world data.

Effect of Adsorbed Water and Temperature on the Universal Power Law Behavior of Lepidocrocite-Type Alkali Titanate Ceramics

2021 ◽  
Author(s):  
Saichon Sriphan ◽  
Phieraya Pulphol ◽  
Thitirat Charoonsuk ◽  
Tosapol Maluangnont ◽  
Naratip Vittayakorn
Keyword(s):  
Power Law ◽  
Adsorbed Water ◽  
Universal Power Law ◽  
Titanate Ceramics

scholarly journals Generic Properties of Curvature Sensing through Vision and Touch

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Birgitta Dresp-Langley
Keyword(s):  
Power Law ◽  
Sensory Modality ◽  
Generic Properties ◽  
Scale Invariant ◽  
Curvature Sensing ◽  
Mathematical Properties ◽  
Universal Power Law ◽  
Sensory Modalities ◽  
Congenitally Blind ◽  
Blind Individuals

Generic properties of curvature representations formed on the basis of vision and touch were examined as a function of mathematical properties of curved objects. Virtual representations of the curves were shown on a computer screen for visual scaling by sighted observers (experiment 1). Their physical counterparts were placed in the two hands of blindfolded and congenitally blind observers for tactile scaling. The psychophysical data show that curvature representations in congenitally blind individuals, who never had any visual experience, and in sighted observers, who rely on vision most of the time, are statistically linked to the same mathematical properties of the curves. The perceived magnitude of object curvature, sensed through either vision or touch, is related by a mathematical power law, with similar exponents for the two sensory modalities, to the aspect ratio of the curves, a scale invariant geometric property. This finding supports biologically motivated models of sensory integration suggesting a universal power law for the adaptive brain control and balance of motor responses to environmental stimuli from any sensory modality.

Nonexponential “blinking” kinetics of single CdSe quantum dots: A universal power law behavior

2000 ◽  
Vol 112 (7) ◽  
pp. 3117-3120 ◽  
Author(s):  
M. Kuno ◽  
D. P. Fromm ◽  
H. F. Hamann ◽  
A. Gallagher ◽  
D. J. Nesbitt
Keyword(s):  
Quantum Dots ◽  
Power Law ◽  
Cdse Quantum Dots ◽  
Universal Power Law ◽  
Kinetics Of

scholarly journals Universal power-law diet partitioning by marine fish and squid with surprising stability–diversity implications

2010 ◽  
Vol 278 (1712) ◽  
pp. 1617-1625 ◽  
Author(s):  
Axel G. Rossberg ◽  
Keith D. Farnsworth ◽  
Keisuke Satoh ◽  
John K. Pinnegar
Keyword(s):  
Species Richness ◽  
Power Law ◽  
Measurement Accuracy ◽  
Scale Free ◽  
Marine Communities ◽  
Trophic Links ◽  
Universal Power Law ◽  
Link Density ◽  
Traditional Approaches

A central question in community ecology is how the number of trophic links relates to community species richness. For simple dynamical food-web models, link density (the ratio of links to species) is bounded from above as the number of species increases; but empirical data suggest that it increases without bounds. We found a new empirical upper bound on link density in large marine communities with emphasis on fish and squid, using novel methods that avoid known sources of bias in traditional approaches. Bounds are expressed in terms of the diet-partitioning function (DPF): the average number of resources contributing more than a fraction f to a consumer's diet, as a function of f . All observed DPF follow a functional form closely related to a power law, with power-law exponents independent of species richness at the measurement accuracy. Results imply universal upper bounds on link density across the oceans. However, the inherently scale-free nature of power-law diet partitioning suggests that the DPF itself is a better defined characterization of network structure than link density.

Sign in / Sign up

Export Citation Format

Share Document