Strength Distribution in Derivative Networks
  This article describes a complex network model whose weights are proportional to the difference between uniformly distributed ``fitness'' values assigned to the nodes. It is shown both analytically and experimentally that the strength density (i.e. the weighted node degree) for this model, called derivative complex networks, follows a power law with exponent $\gamma<1$ if the fitness has an upper limit and $\gamma>1$ if the fitness has no upper limit but a positive lower limit. Possible implications for neuronal networks topology and dynamics are also discussed. 
Luciano da Fontoura Costa and Gonzalo Travieso