Effectiveness of student response systems in terms of learning environment, attitudes and achievement

In order to investigate the effectiveness of using Student Response Systems (SRS) among grade 7 and 8 science students in New York, the How Do You Feel About This Class? (HDYFATC) questionnaire was administered to 1097 students (532 students did use SRS and 565 students who did not use SRS). Data analyses attested to the sound factorial validity and internal consistency reliability of the HDYFATC, as well as its ability to differentiate between the perceptions of students in different classrooms. Very large differences between users and non-users of SRS, ranging from 1.17 to 2.45 standard deviations for various learning environment scales, attitudes and achievement, supported the efficacy of using SRS

Sardonic science? The resistance to more humanistic forms of science education

Resistance to more humanistic forms of science education is an endemic and persistent feature of university scientists as well as school science teachers. This article argues that science education researchers should pay more attention to its origins and to the subtleties of its stubborn influence. The paper explores some of the imperatives which dominate the continuing practices of teachers; the linkages between school and university science; and re-considers the relationships between learning science, learning to do science and learning about science. It draws on recent, prominent publications, as well as neglected and rather more contentious material, to underline the unhelpfully narrow view of science held by those who defend the traditional disciplinary influences of biology, chemistry and physics. Suggestions are made as to where those of a more radical and determined disposition should direct their attention in the interests of improved education, vital scientific progress as well as human survival. It is argued that university science must change in order to ensure that teachers better help their students to learn, do and appreciate science

Selectivity of antimicrobial peptides: a complex interplay of multiple equilibria

Antimicrobial peptides (AMPs) attack bacterial membranes selectively, killing microbes at concentrations that cause no toxicity to the host cells. This selectivity is not due to interaction with specific receptors, but is determined by the different lipid composition of the membranes of the two cell types, and by the peculiar physico-chemical properties of AMPs, particularly their cationic and amphipathic character. However, the available data, including recent studies of peptide-cell association, indicate that this picture is excessively simplistic, because selectivity is modulated by a complex interplay of several interconnected phenomena. For instance, conformational transitions and self-assembly equilibria modulate the effective peptide hydrophobicity, the electrostatic and hydrophobic contributions to the membrane binding driving force are non-additive, and kinetic processes can play an important role in selective bacterial killing in the presence of host cells. All these phenomena, and their bearing on the final activity and toxicity of AMPs, must be considered in the definition of design principles to optimize peptide selectivity