dose of irradiation that is fatal to 50% of the total study population
offspring mortality measurement +
post-insult time of death +
Measurement of the length of time between introduction of a disease-producing or otherwise toxic stimulus and the death of the subject, i.e. the cessation of all vital functions of the body including the heartbeat, brain activity (including the brain stem), and breathing.
ratio of deaths to total study population during a period of time +