Survey data suggest that, in addition to canceling courses and increasing class sizes, districts are responding to shortages by hiring underprepared teachers (teachers who have not yet completed the subject matter and teacher preparation requirements for a full credential); assigning some teachers out of their fields of preparation; and hiring substitutes, who need only pass a basic skills test.Podolsky, A., & Sutcher, L. (2016). (learningpolicyinstitute.org)
Many districts reported responding to shortage conditions by hiring teachers with substandard credentials or permits — meaning those teachers hadn't yet completed the subject matter and teacher preparation requirements for a full credential. (cabinetreport.com)
The technique neatly evades two problems in nanoscale microscopy, the diffraction limit that restricts conventional optical microscopes to resolutions no better than about half the wavelength of the light (so about 250 nm for green light), and the relatively high energies and sample preparation requirements of electron microscopy that are destructive to fragile specimens like tissue. (sciencedaily.com)