People with severe or persistent respiratory conditions (such as chronic lung disease or asthma) may experience stronger adverse reactions.

For most children, experts say the risk of a recurrent stroke is small, except for those with sickle cell disease or another persistent condition.

The evaporites in the geologic record suggested vast and extensive regions of persistent dry conditions near the Pangean equator, serving as the initial evidence for the theory's dissemination.

Intrauterine growth retardation and other perinatal problems raise the possibility of transience, while large birthweight suggests one of the more persistent conditions.

Wheat prices rose sharply on the Chicago Board of Trade yesterday on signs of persistent dry conditions in winter growing regions.

The persistent wet conditions also caused health problems for livestock.

Palinopsia can be a persistent condition, but it is also experienced periodically by migraine sufferers.

In Maryland, the rainfall helped to relieve persistent dry conditions.

Thirty-one-year-old Nancy Cruzan has been in what doctors call a persistent vegetative condition since she was injured in a car crash in January 1983.

Shortly after the 2005 season began, a persistent arthritic condition in his shoulder sidelined him for what turned out to be three-quarters of the season.