It has almost always been the case that some group or groups have controlled and exploited other groups.

These were compared with their littermates and to control groups that experienced no hormone intervention.

A smaller number of distributors control groups of these brands.

Such trials have been chastised for the administration of placebo pills to control groups.

Each of the Chechen "battalions", most not much larger than a traditional company, were groups controlled and kept together by individuals.

"What attracted us to control groups is that we wanted to design our research scientifically," Professor Card said.

However they have also been described as "a loosely allied group of organizations" including "many groups controlled by local clerics."

The question is whether it will be adhered to by the sector's controlling economic groups, which Community policies are increasingly subservient to.

The police admit that they, too, relied on the yakuza to check random street violence and to control left-wing groups.

Tensions in the area broke out when Georgia sent in troops in 1992 to control groups who wanted separation.