1.   And young rats fed diets low in iron learn poorly, while elderly people with zinc deficiencies seem to be at greater risk of developing senile dementia.

2.   At night they slide soundlessly among the branches, hunting mice, young rats or smaller birds.

3.   A similar procedure was performed on adult rodents earlier in the mission as well as on young rat at crucial points in the maturation of their nervous systems.

4.   Dozens of young rats used in brain research experiments on the space shuttle Columbia have died, NASA disclosed Monday.

5.   Fourteen young rats that began the mission at an older age remained healthy as did a small population of adult rats.

6.   Pusztai found differences in the size of several organs in young rats eating the transgenic potatoes, and evidence of damage to their immune systems.

7.   Resembling proud parents, astronauts aboard the shuttle Columbia looked on Thursday as some young rats struggled to take their first steps in weightlessness.

8.   The shuttle crew finished a third session in which they videotaped several other young rats that also had not walked on Earth before the mission.

9.   The researchers found that young rats chirp vigorously during rough-and-tumble play sessions with each other.

10.   They administered cancer-causing substances to young virgin rats, which subsequently developed many mammary tumors.