The evolution of new catalytic activities and specificities within an enzyme superfamily requires the exploration of sequence space for adaptation to a new substrate with retention of those elements required to stabilize key intermediates/transition states. Here, we propose that core residues in the large enzyme family, the haloalkanoic acid dehalogenase enzyme superfamily (HADSF) form a "mold"...

Laser experiments on 1.5at.%, 5at.%, and 8at.% thulium-gadolinium-lutetium-yttrium co-doped, buried, ridgetype channel waveguides in a monoclinic potassium double tungstate demonstrate a maximum slope efficiency of 70% and output powers of 300 mW at ~1.9 μm. Keywords-component; thulium; monoclinic double tungstates; channel waveguide; infrared lasers

Lead Tungstate crystals will be used as calorimetric medium in high energy physics at CERN, in a particularly hostile radiation environment. Methods of testing their behaviour under irradiation are discussed here and are illustrated by some R&D results. Presented at 5th European Conference on Radiation and its Effects on Components and Systems, (Fontevraud, France, September 1999) For the CMS C...