We're all involved in many potential avenues to varying degrees. As I said in my introductory remarks, to date the work that we're involved in is driven largely by the GHGs and the energy usage factor, so given the impact of automobiles and on-road transportation, that's where we focused.
I certainly accept your premise that there's more to do. NRC has work going on in many of those areas, so we've not overlapped. We try to collaborate whenever we can and wherever we can, and to date we've not been involved in the other modes. As I said, there is certainly potential there, but we can't spread it too thin or we'll end up a mile wide and half an inch deep; then we wouldn't be effective in bringing innovation forward, so to date, we've stayed on the road.