Domain differences in the weights of perceptual and conceptual information in children's categorization.

Visual appearance is one of the main cues children rely on when categorizing novel objects. In 3 studies, testing 128 3-year-olds and 192 5-year-olds, we investigated how various kinds of information may differentially lead children to overlook visual appearance in their categorization decisions across domains. Participants saw novel animals or artifacts of varying degrees of similarity to target categories and were asked to place them in 1 of 2 categories.

[Cervical mass as an isolated finding in primary mediastinal seminoma].

Seminoma is a malignant tumor of germ cell origin, usually found in male gonads. Primary seminoma of the mediastinum is rare. The natural history of mediastinal seminoma is growth which is asymptomatic until a late stage, and therefore when diagnosed it is large and causes symptoms of cough, hoarseness and chest pain.