  We investigate the highly incoherent regime of hole-doped 2d Mott-Hubbard
insulators at moderately small doping and temperatures T>=0.1J, where J is the
exchange coupling. Within an extended dynamical mean-field theory of the t-J
model and a generalized non-crossing approximation we calculate the
single-particle spectral function, the dynamical susceptibility, and
thermodynamic and transport quantities. Short-ranged antiferromagnetic
fluctuations lead to strongly incoherent single-particle dynamics, large
entropy and large electrical resistivity. At low doping a pseudogap is found to
open up both in the single-particle and the spin excitation spectra leading to
a decrease in entropy and resistivity. The Hall coefficient changes sign to
positive values upon lowering the doping level and increases inversely
proportional to doping.
