Investigating Instructor Talk in Novel Contexts: Widespread Use, Unexpected Categories, and an Emergent Sampling Strategy.

Instructor Talk-noncontent language used by instructors in classrooms-is a recently defined and promising variable for better understanding classroom dynamics. Having previously characterized the Instructor Talk framework within the context of a single course, we present here our results surrounding the applicability of the Instructor Talk framework to noncontent language used by instructors in novel course contexts. We analyzed Instructor Talk in eight additional biology courses in their entirety and in 61 biology courses using an emergent sampling strategy.

Classroom sound can be used to classify teaching practices in college science courses.

Active-learning pedagogies have been repeatedly demonstrated to produce superior learning gains with large effect sizes compared with lecture-based pedagogies. Shifting large numbers of college science, technology, engineering, and mathematics (STEM) faculty to include any active learning in their teaching may retain and more effectively educate far more students than having a few faculty completely transform their teaching, but the extent to which STEM faculty are changing their teaching methods is unclear. Here, we describe the development and application of the machine-learning-derived algorithm Decibel Analysis for Research in Teaching (DART), which can analyze thousands of hours of STEM course audio recordings quickly, with minimal costs, and without need for human observers.

Properties of xanthine dehydrogenase variants from rosy mutant strains of Drosophila melanogaster and their relevance to the enzyme's structure and mechanism.

Xanthine dehydrogenase, a molybdenum, iron-sulfur flavoenzyme encoded in the fruit fly Drosophila melanogaster by the rosy gene, has been characterised both from the wild-type and mutant files. Enzyme assays, using a variety of different oxidising and reducing substrates were supplemented by limited molecular characterisation. Four rosy strains showed no detectable activity in any enzyme assay tried, whereas from four wild-type and three rosy mutant strains, those for the [E89K], [L127F] and [L157P]xanthine dehydrogenases (in all of which the mutation is in the iron-sulfur domain), the enzyme molecules, although present at different levels, had extremely similar or identical properties.