RESUMEN
A dilatometer system usable to 1600 degrees C in atmospheres varying from oxidizing to reducing, with or without controlled dew points, is described. The system was optimized to measure the shrinkage of a liquid-containing ceramic material without causing deformation by viscous creep. Shrinkages up to 20% may be measured continuously during a heating cycle.
RESUMEN
Because the cot-2 and inv loci of Neurospora crassa are closely linked, the invertase from the morphological mutant, cot-2, was examined. The cot-2 strains produce an invertase with altered heat sensitivity, Km, and ratio of heavy to light forms. The cellular localization of cot-2 invertase is different from that of the wild type. There were no observable changes in the energy of activation or the pH optimum of cot-2 invertase, and some of the differences detected were not apparent under culture conditions that promoted wild-type growth. Since recombination (about 5 percent) occurred between cot-2 and inv and culture conditions affected the enzyme characteristics, we suggest cot-2 determines, in part, the carbohydrate composition of the enzyme.