Theories of ability and the pursuit of challenge among adolescents with mild mental retardation.

Dweck (1991) distinguishes two different ways children can view their abilities. Children who have an 'incremental theory' of their ability believe that it is a changeable, increasable and controllable quantity. Those who have an 'entity theory' believe their ability represents a fixed, unchangeable trait.

Talc pneumoconiosis: a pathologic and mineralogic study.

Seventeen cases of "talc pneumoconiosis" were examined pathologically and mineralogically to ascertain whether a true talc pneumoconiosis existed and also to compare these results in primary, secondary, and tertiary exposures. Mineralogic analyses were performed on wet tissue or tissue blocks by a variety of techniques, including analytical transmission electron microscopy and x-ray diffraction. Overall, the pathologic appearance of the tissues was similar in primary, secondary, and tertiary exposures, although ferruginous bodies and foreign body giant cells were not always present in cases caused by secondary exposures.