professor palinkas, that you thu very much for talking with us. >> it's a pleasure to be here, judy. >> woodruff: how does their situation compare with other extreme situations you've studied or been familiar with? >> well, there are some similarities and there are some differences. they are going to be undergoing an extended period of isolation and confinement. the environmental conditions will be quite severe. similar to being at the south pole, for example, they'll be deprived of sunlight and will have very little sense of day and night. but on the other hand, many people who go on polar expeditions or astronauts in space know what they're getting into when the expedition begins. these miners on the other hand have very little understanding of the likelihood of being under the ground for four monos when they went in for the day of work the uncertainty as to how long it will take for the rescue to occur is also a significant difference compared to other isolated, confined situations where a mission has a very defined temporal parameter. >> woodruff: how will the uncertainty affect