Last year,a study in the medical journal Neurology found smoking to be an established risk factor in developing the disease.

VOA: special.2010.03.09

She was widely recognized by other researchers for her work with a protein called transforming growth factor-beta.

VOA: special.2009.01.27

The third factor is a sense of pride in country and unity with other citizens.

VOA: special.2009.12.19

"While cost remains a major factor in decisions about where to off-source, the quality of the labor pool is gaining importance, and this includes English language skills."

VOA: special.2011.01.21

"So if you have hoarseness with tobacco or alcohol use, that would be a significant risk factor for cancer or other problems of the throat that could be serious.

VOA: special.2009.09.02

The Canadian-American writer John Geiger wrote about this in a recent book called The Third Man Factor. The book will soon be published in several languages, including Chinese, Korean and Japanese.

VOA: special.2010.02.24

One reporter questioned whether the artificial turf at San Jose's Ricardo Saprissa Stadium was a major factor in that loss.

VOA: standard.2009.06.07

Weather is not believed to be a factor. Witnesses say they did not see any fire before the plane broke apart.

VOA: standard.2010.05.12

"It's a risk factor in a similar way that elevated cholesterol is a risk factor for heart disease."

VOA: standard.2010.03.09

In order to attract the rabbit's own stem cells to re-grow the cartilage, channels in the scaffold were filled with a growth factor protein.

VOA: standard.2010.08.11

Columnist David Ignatius agrees with the president's move, saying Pakistan is a key factor in the new strategy,and the pressure on it must be increased.

VOA: standard.2009.12.06

Incumbent leader Hamid Karzai currently holds some But if turns out that vote fraud was a significant factor in the election, then the percentages become meaningless.

VOA: standard.2009.09.11

So,that is being a factor that is constraining for the progress for those countries."

VOA: standard.2009.05.21

"We know that it is a risk factor but we can't attribute the rise in autism to the shifting trend towards having children later in life."

VOA: standard.2010.02.10