We construct a complete metric space M of cardinality continuum such that every non-singleton closed separable subset fails to be Lipschitz retract M. This provides analogue the various classical and recent examples Banach spaces failing have linearly complemented subspaces prescribed smaller density character.

Recently, there has been great interest in 3-D ultrasound imaging, but power constraints have precluded practical implementation of high-resolution and highframe-rate 3-D ultrasound in handheld imaging platforms. In this paper, we propose a separable beamforming procedure for both 3-D synthetic aperture and plane wave systems that drastically reduces computational and hence power requirements. ...