RESUMEN
Two training studies replicated and extended a Scandinavian study by Lundberg, Frost, and Petersen (1988). In Study 1, a 6-month metalinguistic training program was given to kindergartners (mean age: 5 years 7 months) who were later compared to a control group in the regular kindergarten program. Tests of phonological awareness and other metalinguistic and cognitive variables were given before and after training; a metalinguistic transfer test was given after training. Reading and spelling skills were assessed at the end of Grades 1 and 2, respectively. The training program was improved and monitored more closely in Study 2. Both studies revealed short- and long-term effects, consistent with Lundberg et al. (1988) and extending findings from Anglo-American and Scandinavian populations to German children.
Asunto(s)
Fonética , Percepción del Habla , Preescolar , Femenino , Alemania , Humanos , Lenguaje , Masculino , Lectura , Factores de Tiempo , EscrituraRESUMEN
Cats underwent massive microembolization via carotid infusion of 10.5 million microspheres (15 +/- 5 mu in diameter), resulting in brain death within four hours; 87.4 +/- 10.2% of emboli reaching the brain were in the ipsilateral hemisphere; 87.9 +/- 4.4% were in the grey matter; and 12.1 +/- 4.4% were in the white matter. Evans blue and sodium fluorescein dyes were given intravascularly before and at different times after embolization. Fluorescence microscopy disclosed that embolization initially provoked a hyperemic engorgement of both the embolized and nonembolized hemispheres. Multifocal, blood-brain barrier extravasations occurred throughout the ipsilateral cortex and oral basal ganglia. Severe vasogenic brain edema ensued, with migration of extravasations from cortex into the white matter, which initially showed only minimal injury. Migration and accumulation of edema in white matter, with subsequent uptake and swelling of neuroglia and axons, may be related to secondary white matter damage following cortical embolic lesions. Degenerative foci developed throughout the embolized cortex over the one- to four-hour period of this study. These sites may correspond to those areas in which hyperemia and damage to the blood-brain barrier was present shortly after embolization.