Nonlinear ionic pulses along microtubules D.L. Sekulić, B.M. Satarić, J.A. Tuszynski and M.V. Satarić Eur. Phys. J. E, 34 5 (2011) 49 Published online: 23 May 2011 DOI: 10.1140/epje/i2011-11049-0