Abstract: The present invention provides devices and methods for reducing or eliminating sources of systematic errors in the measurement of absolute gravity or gravity field gradients; specifically, an improved test mass for an interferometer is disclosed that reduces the influence of nearby electromagnetic fields on a freefalling test mass.

Abstract: An adjustable orthodontic bracket assembly includes a plurality of brackets. Each bracket is attachable to a front face of a tooth such that the bracket is positionable in series relation to one or more other of the brackets. Each bracket is continuously adjustable in at least three planes and, preferably, in six planes of motion without a need to replace any parts thereof. The adjustment of each bracket in one of the planes of motion can be accomplished without affecting the adjustment of the bracket in any of the other planes of motion. Specifically, each bracket is capable of adjustment in at least three and, preferably, all of vertical, lateral and mesio/distal translational planes of motion and tip, torque and circular rotational planes of motion. Also, the assembly includes an arch wire extending between and retained on the brackets.