Nonlinear balance and exchange of stability in dynamics of solitons,   peakons, ramps/cliffs and leftons in a 1+1 nonlinear evolutionary pde
  We study exchange of stability in the dynamics of solitary wave solutions under changes in the nonlinear balance in a 1+1 evolutionary partial differential equation related both to shallow water waves and to turbulence. We find that solutions of the equation $ m_t + um_x +b u_xm = \nu m_{xx} $ with $m = u - \alpha^2 u_{xx}$ for fluid velocity $u(x,t)$ change their behavior at the special values $b=0,\pm1,\pm2,\pm3$. 
Darryl D. Holm and Martin F. Staley