BACKGROUND AND PURPOSE The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this stu...

This study examined the generality of the logarithmic to linear transition in children's representations of numerical magnitudes and the role of subjective categorization of numbers in the acquisition of more advanced understanding. Experiment 1 (49 girls and 41 boys, ages 5-8 years) suggested parallel transitions from kindergarten to second grade in the representations used to perform number l...

The aim of the study is to analyse middle school students’ estimation performances (the accuracy estimation) in regard measurement based on several variables, including their attitudes towards estimation, experience gender and grade level. employs quantitative methods, namely causal comparison relational designs. participants are 490 students attending public schools Ankara. Data collection too...

We employ a standard identification strategy from the peer effects literature to investigate the importance of network definitions in estimation of endogenous peer effects. We use detailed information on friends in the National Longitudinal Study of Adolescent Health Survey (Add Health) to construct two network definitions that are less ad hoc than the school-grade cohorts commonly used in the ...