Until recently, trade flows were of interest mainly to economic experts and executives of large corporations, but since the past few years, the movement of goods and services across national boundaries have become the subject of intense public attention all over the world.

According to some botanists, invasive plants are the second most serious threat, after habitat loss, to native species of plants and animals and to the maintenance of biologically diverse ecosystems.

Both the Federal Reserve's decision that borrowing rates be raised, along with investor's speculation that another increase might be on the way, helped bolster the dollar in recent weeks by making deposits more attractive.

Researchers hypothesize that granitic soil is the ideal construction material for the desert tortoise because it is not so hard that it makes burrowing difficult or so soft that it could cause tunnels to collapse.

Known today by a name they would not have recognized—Anasazi, Navajo for "ancient enemies"—the ancestors of the modern Zuni and Hopi built and then, for reasons still mysterious, abandoned the complex roads and structures of the domain they ruled a millennium ago in the American southwest.

Because of a similarity to dance, synchronized swimming—exhibition swimming in which the movements of one or more swimmers synchronize to a musical accompaniment—is sometimes called water ballet, especially in theatrical situations.

A March 2000 Census Bureau survey showed that Mexico accounted for more than a quarter of all foreign-born residents of the United States, the largest share for any country to contribute since 1890, when about 30 percent of the country's foreign-born population was from Germany.

According to a recent study of consumer spending on prescription medications, increases in the sales of the 50 drugs that were advertised most heavily accounts for almost half of the $20.8 billion increase in drug spending last year, the remainder of which came from sales of the 9,850 prescription medicines that companies did not advertise or advertised very little.

The Environmental Protection Agency's proposal to place restrictions on both diesel fuel and diesel engines has sparked a counterattack by the oil industry, saying that the move will exacerbate the nation's fuel supply problems.

Almost like clones in their similarity to one another, the cheetah species' homogeneity makes them especially vulnerable to disease.