DefinitionsThe movement of ocean water is one of the twoprincipal sources of discrepancy between dead reckonedand actual positions of vessels. Water in motion is called acurrent; the direction toward which it moves is called set,and its speed is called drift.
Human RBC precursors are obtained by (i) separating glycophorin A(+) (gly A(+)) cells using a magnetic cell sorting (MACS) technique and by (ii) ex vivo expansion of precursors BFU-E (burst forming unit-erythroid) on methylcellulose semi-solid culture media from mononuclear cells of cord blood.
Cholesterol as a precursor. Cholesterol is a major precursor in the synthesis of vitamin D, steroid hormones and sex hormones. Examples of the various steroid hormones include corticosteroids such as aldosterone (a mineralcorticoid), cortisol (a glucocorticoid) and cortisone.