Concern over the plant's continuing safety problems has heightened since Sept. 11.

Such concerns will probably heighten during the next few weeks, as banks report second-quarter results.

Washington's concerns about the security of Pakistan's nuclear weapons program heightened after the Sept. 11 terrorist attacks.

Concern heightened at the time of the Falklands War.

Concern about water scarcity has heightened because of a recent drought in northern regions, which some scientists fear is linked to global climate change.

The concern heightened when the next hitter, Orlando Miller, drilled a single to right.

Such concerns have heightened investors' unwillingness to buy stocks, continuing a recent trend in which early market gains evaporate into declines by the day's end.

Concerns about a pandemic scenario heightened.

Concern over Japan's hostage problem heightened with the disappearance of about 20 Japanese citizens from a Baghdad hotel over the weekend.

Environmental politics and related concerns regarding carbon emissions have heightened sensitivity to gas mileage standards and environmental protection worldwide.