The symptoms also suggest that estrogen acts directly on bone cells, rather than through an indirect mechanism, as had been proposed.

They enhance plant growth by several direct and indirect mechanisms.

Darwinian evolution works by the indirect and inefficient mechanism of natural selection.

There are two main indirect mechanisms.

In recent years many economists have argued that there is another important indirect mechanism through which changes in money supply affect aggregate demand.

The indirect mechanism operates via interest rates or exchange rates.

Monetarists also see monetary policy operating through the indirect mechanisms.

The investigators stress that other, more indirect mechanisms that had been proposed previously still might play a role.

"As long as we've got these indirect mechanisms to deal with home instruction, then the districts and the parents are both at a disadvantage," he said.

This indirect mechanism of action is referred to as transrepression.