this descriptive study was conducted to determine the prevalence of asthma and related symptoms among 6-7 and 13-14 year old school children in tehran as a part of international study of asthma and allergies in childhood (isaac) phase iii. the isaac written questionnaire was given to a total of 6127 students of 72 schools in urban area of tehran. simple random sampling was performed with a unif...

We define a compactum X to be AB-compact if the cofinality of the character χ(x, Y ) is countable whenever x ∈ Y and Y ⊂ X. It is a natural open question if every AB-compactum is necessarily first countable. We strengthen several results from [Arhangel’skii and Buzyakova, Convergence in compacta and linear Lindelöfness, Comment. Math. Univ. Carolin. 39 (1998), no. 1, 159–166] by proving the fol...