Thanks Rick.

"The heartening thing to me is that with a rich, complex collection of causes there are a rich, complex set of opportunities to intervene. "

its true, but it is also a problem when you dont know what you are looking for. Current description of PD seems similar to ten blind men describing an elephant they are touching, each has a part of the elephant but no one has a complete picture (this is an Indian story, there must be an equivalent one here!).

girija