  We present evidence for disconnected contributions to the $\sigma_{\pi N}$
term and the flavor singlet axial coupling $g_A^0$ of the proton on full QCD
configurations, which are obtained by means of improved stochastic estimator
techniques. Furthermore we discuss results from the fermionic determination of
the topological charge of the QCD vacuum (in the spirit of the Athiya-Singer
theorem) again achieved with stochastic estimator methods. It turns out that
this approach provides an monitor for the tunneling efficiency of the HMC on
QCD with dynamical Wilson fermions which is independent on the pure gluonic
method that implies cooling.
