Abstract: Described herein is a variant human acidic mammalian chitinase (AMCase) enzyme having improved stability and an isolated nucleic acid sequence which encodes the variant. The invention also provides to nucleic acid constructs, vectors, and host cells comprising the nucleic acid sequences as well as methods for producing recombinant variant AMCase polypeptide and its use in screening assays to identify modulators.

Abstract: A test station for use in evaluating semiconductor chips and the like. The test station has improved components for supporting and adjusting the positions of a microscope and stage relative to a base surface which supports a plurality of probes.

Abstract: Apparatus is provided for guiding a pellicle-covered photomask or other flat object into viewing position for inspection upon a flat top plate of a stage below the objective of a microscope. The apparatus includes a pair of spaced parallel rails having inwardly extending upper and lower flanges that define opposed keyways in which keybars at the edges of a photomask-carrying paddle slide. To protect the pellicle membrane and to space the latter above the top stage top plate, at entrance ends of the rails, segments of the upper flanges are recessed greater than the width of the paddle to permit a vertical dropping movement of the leading end of paddle onto inlet horizontal guide surfaces. These guide surfaces are broad platforms on which may be deposited the leading end of the paddle.