vie. vb, vies, vying or vied. 1. (intr; foll by with or for) to contend for superiority or victory (with) or strive in competition (for). 2. (tr) to offer, exchange, or display in rivalry. [C15: probably from Old French envier to challenge, from Latin invÄ«tÄre to invite].
On rare occasions, a halfback is asked to throw the ball when running a HB option. This play is generally referred to as a half-back pass, regardless if the player throwing the football is a tailback or fullback.
Hemoglobin (or haemoglobin, frequently abbreviated as Hb), which is contained in red blood cells, serves as the oxygen carrier in blood. The name hemoglobin comes from heme and globin, since each subunit of hemoglobin is a globular protein with an embedded heme (or haem) group. Each heme group contains an iron atom, and this is responsible for the binding of oxygen. The presence of hemoglobin in blood increases the oxygen carrying ability of a litre of blood from 5 to 250 ml. Hemoglobin also plays a major role in the transport of carbon dioxide from the tissues back to the lungs.