Abstract: Systems and methods for lesson-based virtual reality (VR) welding training are provided. Broadly, the system creates a configurable, three-dimensional, virtual reality training environment displayed on a VR display. Using a handheld controller associated with the VR display, a student may select a welding lesson. The welding lessons correspond to a variety of different settings, such as welding process type, workpiece type, workpiece position, finishing tool type, guidance mode, and welding machine settings. The student then creates a weld on the workpiece via the handheld controller, and the system provides real-time feedback, such as audio, visual, and/or haptic, to the student. Once the student has completed the weld, the system generates and displays an assessment of the weld.

Abstract: A polypeptide isolated from the venom of the Agelenopsis aperta spider blocks calcium channels in cells of various organisms and is useful in blocking such calcium channels in cells per se, in the treatment of calcium channel-mediated diseases and conditions, and in the control of invertebrate pests.

Abstract: Compounds of formula (I) ##STR1## in which R.sub.1 represents hydrogen, a C.sub.1-6 aliphatic hydrocarbyl group or a C.sub.1-4 aliphatic hydrocarbyl group substituted by a C.sub.3-6 alicyclic hydrocarbyl group or by a phenyl group, which phenyl group is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.2 represents hydrogen, R.sub.3 represents hydrogen, a 5-or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur which is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, or a group AR wherein A is a straight chain C.sub.1-4 aliphatic hydrocarbyl group terminally substituted by R which is hydrogen, a phenyl group or a 5-or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur, which phenyl or heterocyclyl group R is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.4 and R.sub.

Abstract: Compounds of formula (I) ##STR1## in which R.sub.1 represents hydrogen, a C.sub.1-6 aliphatic hydrocarbyl group or a C.sub.1-4 aliphatic hydrocarbyl group substituted by a C.sub.3-6 alicyclic hydrocarbyl group or by a phenyl group, which phenyl group is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.2 represents hydrogen, R.sub.3 represents hydrogen, a 5- or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur which is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, or a group AR wherein A is a straight chain C.sub.1-4 aliphatic hydrocarbyl group terminally substituted by R which is hydrogen, a phenyl group or a 5- or 6-membered ring aromatic heterocyclyl group containing one or two heteroatoms selected from nitrogen, oxygen and sulphur, which phenyl or heterocyclyl group R is unsubstituted or substituted by a halogeno or C.sub.1-3 halogenoalkyl group, R.sub.4 and R.sub.

Abstract: Vesiculated polymer beads are prepared in which a water-in-oil-in-water emulsion containing a cross-linkable polymer and a copolymerizable monomer in the oil phase is heated in the presence of an initiator to cure the polymer beads, wherein curing is commenced in a first stage in the presence of a substantially water-insoluble initiator and, when the beads are sufficiently stable, curing is completed in a second stage in the presence of an at least partially water-soluble initiator. Preferably, the completion of curing is carried out at a temperature higher than that of the first stage. The beads can be used in low odor paint formulations.