21.   It was concluded that good schools can, and do, exert an important protective effect against behavioural disturbance.

22.   Investigators focusing on the ill-effects of life stress on mental health have also demonstrated the protective effects of social support.

23.   Although the crucial relationships were pre-existing, and of a close, confiding quality, their protective effect derived from the support during the crisis.

24.   It may be that only when key supportive figures are lacking, or have been lost, that others in the wider social network can have a protective effect.

25.   Some may have stronger bones to start with or there may be a protective effect from exercise or other factors.

26.   An earlier study in men also showed a protective effect of fiber on the heart, though not as strong an effect as was observed in women.

27.   And the protective effect of the mumps vaccine wears off, unlike mumps itself, which affords lifetime immunity.

28.   As consumption increases, the researchers found, the protective effect is lost.

29.   As the spheres slowly dissolve, he said, animal tests indicate they may offer a protective effect for four to six months.

30.   Aspirin, unlike other anti-inflammatory drugs, did not appear to have a protective effect, possibly, the researchers said, because participants were taking very low doses.