Researchers study the impact of these changes on food production.

Researchers studied 3,718 people 65 and older over six years.

Researchers studied 244 children, following them from the age of three to seven.

The researchers studied the children for an average of two and a half years.

Environmental changes can have an impact, too, and that's what the researchers studied.

Chinese researchers are now studying it for the first time.

The researchers studied data collected over 40 years in the park.

Researchers studied 2,447 men over 12 years, examining them every other year.

The researchers studied 200 women aged 40 to 78 for eight weeks.

But the Texas team said few contemporary researchers have studied it.