The link above is to a fermi lab program to look for Dyson spheres. The Matrioshka brain is a subset of the Dyson sphere. Something made famous, unfortunately, by Trekkers.
Unfortunate because it has distorted the original idea beyond recognition. :)
A lot of people know F. J. Dyson only for Dyson "spheres" (the original conception was that of a swarm, SF modified the idea to a sphere, then shell). Though it's obvious he did a lot of other work and that the Dyson sphere was nothing as compared to what he has done. It was just a thought experiment.
I notice some people above saying that it could be a mistake. I think it could be. But it is less likely that it was.
I say that because Pachauri had been saying for a year that the Indian government was being arrogant by not agreeing to their "findings". And he rejected research such as this : http://moef.nic.in/downloads/public-information/MoEF%20Discu...
Compiled by people who have 3-4 decades of experience in Himalayan glaciology.
Please do check that review paper. It is not easy to find.
I think this is a very helpful page.