Preliminary studies on the detection ofMycobacterium avium-intracellulare complex using DNA probe from a clinical isolate

Genomic DNA from a clinical isolate ofMycobacterium avium-intracellulare complex was purified and cloned in PBR 322 at the tetracycline resistance site using Bam HI restriction enzyme. A 16 kb cloned fragment was purified, radiolabeled and used as a probe. Genomic DNA isolated from nineteen MAC strains, threeM. tuberculosis strains and oneM. kansasii strain were digested with Eco RI restriction enzyme, Southern blotted and hybridized with the 16 kb cloned and labeled fragment. Twelve MAC strains showed positive hybridization although five strains gave faint signals. Positive hybridization was noted in two out of the threeM. tuberculosis strains, possibly due to shared DNA homology. No signal was received from the singleM. kansasii strain used in this study.     

Are mathematics disabilities due to a domain-general or a domain-specific working memory deficit?

The relationship between verbal and visual-spatial working memory and mathematical computation skill was examined in children and adults with and without disabilities in mathematics. A hierarchical regression analysis showed that, when partialing for the influence of reading ability, age, and gender, mathematical computation was better predicted by verbal than by visual-spatial working memory. Furthermore, the results showed that the relationship between mathematics ability and working memory were not significantly moderated by age but were stable across a broad age span. We concluded that, regardless of age, deficits in mathematics are mediated by both a domain-general and a domain-specific working memory system.     

A Framework for Epistemological Discussion on Integrated STEM Education

Science & Education - In primary and secondary schools, the disciplines encompassed in “STEM”—Science, Technology, Engineering and Mathematics—have usually been studied...     

BE COOL! a digital learning environment to challenge and socially include gifted learners

Educational technology research and development - This paper describes the development of the BE COOL! learning environment that gives all children, gifted and non-gifted, the opportunity to learn...     

Pedro Gutiérrez Bueno’s Textbooks: Audiences, Teaching Practices and Chemical Revolution

Pedro Gutiérrez Bueno wrote two editions of a chemistry textbook between 1788 and 1802. The paper offers a comparative view of both editions taking into account Gutiérrez Bueno’s biography, his intended audience and the changes related to the so-called chemical revolution. Some conclusions are at odds with common images about scientific revolutions and the role of textbooks in science. The analysis aims to shed some light on the multiple historical forces shaping textbooks and the way in which scientific change is assimilated by their writers. This research was partially supported by the program BHA2002-04611-CO3-02     

Institutional Contexts and International Performances in Schooling: comparing patterns and trends over time in international surveys

15 European countries were classified into four types in an international comparative study. The country profiles are based on indicators of the key concepts' funding, governance and choice. This research attempts to answer the question of how the quality of schooling of these types of education systems progressed as from 1995 and what explanations an expert panel of educationalists and researchers can provide for the outcomes. We observe significant differences between the performance trends of the four types of education systems. Also, comparisons between the different years show relatively high and significant correlations, especially between the original sample of countries in 1995 and future performances in TIMSS and PISA measurements.