Phonological features of child African American English.

The production of phonological features of African American English (AAE) was examined for 64 typically developing African American children in the 2nd through the 5th grade. Students read aloud passages written in Standard American English. Sixty of the students read the passages using AAE, and 8 different phonological features were represented in their readings. Phonological features were more frequent than morphosyntactic features. The findings as a whole support use of the taxonomy developed for this investigation in characterizing the phonological features of child AAE.     

Parents' facilitation of young children's writing

This study investigated the impact of a home composing curriculum on kindergarten children's concepts about print (a measure of reading readiness), writing fluency (the number of words children can write), and writing achievement. In addition, the study investigated gender differences on the above measures, types of writing done by children at home, and family members with whom children wrote. The treatment group was found to be significantly higher on the Concepts about Print test, writing fluency, and the first post-test of writing achievement. There were no significant gender differences on any of the measures. Data from parent response sheets indicated that these children wrote notes, letters, and lists more than other types of writing. They wrote with their mother or alone more often than with other family members. The findings of this study suggest that a flexible home composing curriculum, combined with the sharing of writing at school can have an impact on reading readiness, the number of words children can write, and possibly writing ability.     

Quantitative Characterization of Epicardial Wave Fronts During Regional Ischemia and Elevated Extracellular Potassium Ion Concentration

This study applied zero-delay wave number spectral estimation as a means of quantifying the changes in activation and recovery sequences of propagating plane waves on the epicardial surface of in situ porcine hearts during regional hyperkalemia and ischemia. Unipolar electrograms (104) were recorded from the left ventricular surface of nine hearts using a plaque electrode array with 1 mm spatial sampling intervals. The objectives were (1) to define a set of parameters capable of quantifying the spatial and temporal changes in measured extracellular potentials associated with localized ischemia prior to the onset of conduction block; (2) to elevate regional levels of extracellular potassium ion concentration and quantify potential changes due to this known physiologic manipulation; and (3) to use quantitative parameters to make statistical comparisons in order to distinguish wave fronts during normal, ischemic and hyperkalemic conditions. Results showed that the parameters of wave number and average temporal frequency and the associated power, as determined from the wave number spectrum, provided statistically significant (p < 0.05) quantification of changes in wave front features during normal and ischemic or hyperkalemic conditions. The results were consistent with results obtained from conventional time–space domain methods like isochronal mapping and electrograms, with the advantage of a quantitative result enabling simple comparisons and trend analysis for large numbers of heart beats. © 1998 Biomedical Engineering Society. PAC98: 8759Wc, 8722Fy, 8780+s