He arrived at MIT four and a half years ago assuming that truly understanding how cells work was the main hurdle facing synthetic biologists.

FORBES: Drew Endy aims to reinvent the biotechnology industry.

Finding a persuasive shape for a large-scale work is perhaps the trickiest hurdle for a younger composer.

NEWYORKER: The Long Haul

The work requirement, according to the developer, has been the biggest hurdle.

ECONOMIST: America's mixed-income experiment

Recession itself could also prove too big a hurdle: in Chicago, TIF-district tax revenues are slowing, and so is building work.

ECONOMIST: Britain looks westward for tips on tarting up its towns