Phenylalanine is an essential amino acid and vital precursor used by the brain to produce dopamine, epinephrine and norepinephrine, stimulatory neurotransmitters that regulate mood, sex drive, memory, alertness, and learning. (nutritionreview.org)
The awards are often seen as vital precursors for the Oscars, nominations for which will be announced on 23 January. (theguardian.com)
To be sure, some vital precursor technology was lacking, particularly the computational horsepower needed to reveal your friends - of - friends - of - friends. (newscientist.com)