STOCKHOLM?The Nobel committees confirmed the overwhelming domination of American laureates in the fields of medicine, physics and chemistry as they awarded the prestigious prizes this week.

In the first three days of the 2009 Nobel award season, eight of the nine laureates honored by the Stockholm-based committees were American citizens.

Many of those hold dual nationality, having obtained US citizenship while living there as researchers, with the well-funded US universities and research institutes long drawing the top scientists in their fields.

This year's medicine laureate is Australian-American Elizabeth Blackburn. The physics winners are Willard Boyle, a citizen of both Canada and the United States, and Charles Kao, a British-American born in China.

One of this year's chemistry winners, Indian-born US citizen Venkatraman Ramakrishnan has done most of his research in the US although he now works in Britain.

In the past 25 years, the Nobel Chemistry Prize, which was awarded Wednesday to Ramakrishnan alongside an American and an Israeli, has only twice gone to non-Americans: in 1988 and 2007, when it went to German scientists.

The Nobel Medicine Prize has gone to laureates from countries other than the US only five times since 1985 (1987/Japan; 1991/Germany; 1996 Switzerland-Australia; 2005/Australia; 2008/France-Germany).

And only seven times has the Physics Prize not gone to an American (1985/Germany; 1986/Germany-Switzerland; 1987/Germany-Switzerland, 1991 and 1992/ France; 1999/The Netherlands; 2007/France-Germany).

In the past quarter century, the number of American researchers awarded a Nobel in medicine was 34 out of 54 laureates.

For physics the number was 37 out of 62 laureates and for chemistry 30 out of 54, according to Agence France-Presse's tally, as the Nobel foundation does not make lists according to laureates' citizenships.