Increased immigration is the key to sustaining the quality of life enjoyed by Americans, an article recently published in Businessweek.com argues.  There’s reason for this view.  Foreign-born nationals in 2006 were inventors or co-inventors of one-quarter of all patent applications filed in the U.S.  Further, one-quarter of science and technology companies founded from 1995 to 2005 had a foreign-born lead technologist or chief economist, and these businesses employed 450,000 workers.