We suggest a minimalistic model for directed networks and suggest an application to injection and merging of magnetic field lines. We obtain a network of connected donor and acceptor vertices with degree distribution 1/s2, and with dynamical reconnection events of size Δs occurring with frequency that scale as 1/Δs3. This suggest that the model is in the same universality class as the model for self organization in the solar atmosphere suggested by Hughes et al.(PRL {\bf 90} 131101).
@article{arxiv.nlin/0403005,
title = {A simple model for self organization of bipartite networks},
author = {Kim Sneppen and Martin Rosvall and Ala Trusina and Petter Minnhagen},
journal= {arXiv preprint arXiv:nlin/0403005},
year = {2007}
}