greatest concentration or amount of a substance, found by experiment or observation, that causes no alterations of morphology, functional capacity, growth, development, or life span of target organisms distinguishable from those observed in normal (control) organisms of the same species and strain under the same defined conditions of exposure

greatest concentration or amount of a substance, found by experiment or observation, that causes no alterations of morphology, functional capacity, growth, development, or life span of target organisms distinguishable from those observed in normal (control) organisms of the same species and strain under the same defined conditions of exposure

pühadeaeg 25.–27. detsembril, mil ristiusu kirikus tähistatakse Kristuse sündimist, eesti rahvakalendris talvise pööripäeva tähistamise periood (21. detsember – 7. jaanuar)