Shell-model calculation of high-spin phenomena in 128Ba, assuming an inert z=50=N core with g1/2d5/2d3/2s1/2 and h11/2 valence orbitals, have been carried out. The positive parity part of the space was truncated to leading representations of pseudo SU(3) and the negative parity part to seniority zero and two configurations. The effect of pair scattering from positive to negative parity orbitals was investigated. Pair alignment is found to be the primary mechanism for backbending and the band crossing can lead to B(E2) strength anomalies.