Abstract: A process for producing a polyurethane, comprising polyesterifying a carbamate containing at least two functional groups selected from hydroxyl groups and carboxylic acid groups or esters or anhydrides thereof, in the presence of a polyesterification enzyme, and optionally in the presence of one or more copolymerizable monomers having two or more functional groups selected from hydroxyl groups and carboxylic acid groups or esters or anhydrides thereof. This process enables a broader range of polyurethanes to be accessed commercially than the previously described processes.

Abstract: A method and apparatus is provided for performing occlusion testing in a computer graphics display system. The apparatus comprises logic configured to determine whether or not an object of a current image frame was occluded in a previous image frame. If a determination is made that the object was not occluded in the previous image frame, then the logic causes the object of the current image frame to be rendered to a frame buffer of the computer graphics display system. The current and previous image frames are each comprised of a plurality of objects, and the logic determines whether or not each of the objects of the current image frame were occluded in the previous image frame. The logic causes any objects of the current image frame that were not occluded in the previous image frame to be rendered to the frame buffer.

Abstract: A support harness for a child to be used when learning activities such as skating, in-line skating, and bicycling. The support harness comprises a length adjustable chest strap having a releasable fastener, a left and right length adjustable shoulder strap, each of the shoulder straps being connected by slidable loops to the length adjustable chest strap at anterior and posterior chest strap regions; and a length adjustable handle strap with a grasping region. The handle strap is connected to the left and right shoulder straps at left and right posterior shoulder strap positions. The design and the materials used in its construction allows this support harness to be manufactured at minimal cost. It has been found that the points of support, near the shoulders and approximately aligned to the back of the neck region of the child allow the child to maintain an appropriate posture for skating and bicycling.