The healthy stem cells might then prevent the damage.
Mutations occur spontaneously, but most organisms have mechanisms that can prevent the damage they might cause.
"We want to prevent the damage — we don't want to clean it up," Mr. Bonano, the emergency-preparedness director, said.
So if financial crises are hard to predict, can anything be done to prevent the damage they cause?
Its democratic traditions, it is often said, including a free press, independent judiciary and vigorous social activism, will help prevent the damage.
"Most urgent is how we prevent the damage from the monsoon season," the report quoted Pak Chol-su, the chief North Korean delegate, as saying.
There are signs that German and Iranian officials conspired behind the scenes in a last-gasp effort to prevent the damage going even further.
But there was also serious concern that the United States had not policed its markets carefully enough to prevent the damage to its economy and others, making it much harder to raise money for the world's most vulnerable people.
Lifestyle changes can significantly reduce the chance of developing diabetes and other diseases of our time, and if people begin young enough, maybe they can prevent the damage from accruing in the first place.
What appears to have happened is that many investors have recovered their confidence that the securitization structure works, and will prevent the damage from climbing too far up the securitization ladder.
His raft ride was one of several makeshift maneuvers that helped prevent the damage from the fire at the North River Wastewater Treatment Plant in Harlem from continuing to wreak havoc across the city, according to workers interviewed this week.
