Nambu Sigma Model and Branes
  In analogy to Nambu's generalization of mechanics, we present a generalization of Poisson sigma models to higher dimensional world volumes. We find corresponding generalizations of string sigma models and open-closed string relations for background fields to the case of p-branes. As an application, we discuss a DBI-type effective action for open membranes. 
Peter Schupp and Branislav Jurco
hep-th