  This paper emphasizes that non-linear rotational or diamagnetic
susceptibility is characteristic of Bose fluids above their superfluid Tcs. For
sufficiently slow rotation or, for superconductors, weak B-fields this amounts
to an incompressible response to vorticity. The cause is that there are terms
missing in the conventionally accepted model Hamiltonian for quantized vortices
in the Bose fluid. The resulting susceptibility can account for recent
observations of Chan et al on solid He, and Ong et al on cuprate
superconductors.
