  A study of nonstrange meson-baryon systems has been made with the idea of
understanding the properties of the low-lying $1/2^-$ $N^*$ and $\Delta$
resonances. The coupled channels are built by considering the pseudoscalar and
vector mesons together with the octet baryons. The formalism is based on
obtaining the interactions from the lowest order chiral Lagrangian when dealing
with pseudoscalar mesons and relying on the hidden local symmetry in case of
the vector mesons. The transition between the two systems is obtained by
replacing the photon by a vector meson in the Kroll-Ruderman theorem for the
photoproduction of pseudoscalar mesons. The subtraction constants, required to
calculate the loop-function in the scattering equations, are constrained by
fitting the available experimental data on some of the reactions with
pseudoscalar meson-baryon final states. As a consequence, we find resonances
which can be related to $N^*(1535)$, $N^*(1650)$ (with a double pole
structure), $N^*(1895)$ and $\Delta(1620)$. We conclude that these resonances
can be, at least partly, interpreted as dynamically generated resonances and
that the vector mesons play an important role in determining the dynamical
origin of the low-lying $N^*$ and $\Delta$ states.
