MRI of a knee. MRIs employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field.
Noun. 1. aestivation - (zoology) cessation or slowing of activity during the summer; especially slowing of metabolism in some animals during a hot or dry period. estivation. zoological science, zoology-the branch of biology that studies animals.
It's deactivated yeast, frequently the strain used is Saccharomyces cerevisiae. Totally dead yeast. Usually it is cultured in something sweet for a few days, then heated to deactivate it. It adds a nutty, savory, almost meat-y depth of flavor to recipes. (The term is 'umami').