Its roving scientists are courageous, effective and unusually persistent.

Rarely, in unusually persistent and distressing cases, some women have had their labor induced as soon as they are considered to be at term (37 weeks).

In addition, this young $13 workhorse wine's finish is unusually persistent, so its freshness lingers and lingers.

There it picked up moisture, some of it probably produced by the unusually persistent El Nino.

Strikes by pilots, cabin crew and ground staff, were compounded last winter by unusually persistent fog at under-equipped north Italian tourist airports.

Veterinarians throughout Long Island say that they have been encountering an unusually persistent cough in dogs this year, particularly in puppies.

The poisonous effects of the Alaskan oil spill could be unusually persistent, scientists said today.

An unusually persistent red tide bloom has been causing health problems for residents and visitors in much of southwest Florida since Christmas.

At the same time, jobless black Americans have been unusually persistent about staying in the labor force.

Although our weather is normally dominated by westerly winds in winter, they have been unusually persistent and strong through December and into January.