  We explain the B-model origin of extended Picard-Fuchs equations satisfied by
the D-brane superpotential on compact Calabi-Yau threefolds. Via the
Abel-Jacobi map, the domainwall tension is identified with a Poincare normal
function--a transversal holomorphic section of the Griffiths intermediate
Jacobian. Within this formalism, we derive the extended Picard-Fuchs equation
associated with the mirror of the real quintic.
