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ABSTRACT:In this paper, we examined data collected as part of a 5-year project designed to foster reform-based urban science teaching through teachers' communities of inquiry. Drawing upon a distributed leadership framework, we analyzed teacher "talk" during professional learning community (PLC) meetings. This analysis yielded five elements: teacher learning and collaboration, community formation, confidence in knowledge of content and guided inquiry, concerns about the impact of accountability measures on teaching and learning, and sustainability of reform. Follow-up interviews with participants reinforced the importance of these elements. While accountability measures were found to have a significant impact on science teaching, participants were also able to use their PLCbased experiences to develop strategies to deal with such external constraints. Facilitation and leadership also play key roles in establishing and maintaining PLCs in this urban setting. Finally, we present a revised framework that incorporates the elements we identified to describe those local and systemic factors critical for successful implementation and influence of professional development efforts. C 2010 Wiley Periodicals, Inc. Sci Ed 95: 543 -570, 2011

Research shows that students face challenges as they learn about genetic inheritance. The challenges could emanate from the fact that genetic inheritance involves unseen processes at different organizational levels. We explored students' understanding of heredity and related concepts such as cells and reproduction using a Web-based Science Inquiry Environment (WISE) curriculum unit that was developed to help middle school students learn about genetic inheritance. Our findings suggest that students made significant gains from pretest to posttest. However, despite overall gains, some students struggled to explain the importance of mitotic and meiotic divisions in transferring genetic information.

Abstract

Field tests showed that Anopheles gambiae s.l. from 4 villages in Gokwe District, Midlands Province, Zimbabwe, were susceptible to 4% DDT, 0.025% deltamethrin, 0.025% alpha-cypermethrin, and 0.1% lambdacyhalothrin. In the laboratory, F1 progeny of field-caught females that were identified as Anopheles arabiensis Patton were completely susceptible to deltamethrin, alpha-cypermethrin, lambdacyhathrin, and DDT. The use of insecticides in Gokwe district has not yet induced detectable resistance in An gambiae s.l.