Benefits of self‐paced learning modules for teaching quantitative methods in environmental science

Abstract

This is a multiple‐indicators evaluation of an innovative approach, using self‐paced learning modules accompanying computerised exercises as an adjunct to teaching quantitative concepts and skills to environmental science students at university. The evaluation data, based on a pre‐unit and a post‐unit questionnaire survey completed by 38 students, show high levels of student satisfaction with the unit as a whole, and the self‐paced workbooks in particular. Students also indicated a clear preference for learning from self‐paced workbooks compared to learning from textbooks. Some students applied the quantitative skills acquired to other academic units, or took the initiative to learn to use additional statistical procedures (not covered in the unit) for academic purposes. However, comparison of students’ levels of interest and confidence in quantitative subjects before and after the completion of the unit did not yield significant changes. Implications of the research findings for university science education are discussed.     

Socio-emotional climate of storybook reading interactions for mothers and preschoolers with language impairment

The current study describes the storybook reading behaviors of 45 preschoolers [30 with language impairment (LI) and 15 with typical language (TL)] and their mothers. Each dyad was observed reading a storybook within their homes, and sessions were subsequently coded for indicators of emotional and instructional quality as well as for child participation. Mothers of children with LI showed lower levels of emotional support than mothers of children with TL, although all mothers exhibited similar quality of instruction. The two groups of children were equally enthusiastic about the book; however, children with LI were observed to be less compliant than children with TL and showed a trend to be less persistent. For the children with LI, participation in the book reading task was found to be high only when mothers’ behaviors were observed to be highly sensitive in nature, demonstrating the importance of exposing children to maternal behaviors that are responsive to their unique abilities and needs.     

Piper sarmentosum as an antioxidant on oxidative stress in human umbilical vein endothelial cells induced by hydrogen peroxide

Endothelial cell death due to increased reactive oxygen species(ROS) may contribute to the initial endothelial injury,which promotes atherosclerotic lesion formation.Piper sarmentosum(PS),a natural product,has been shown to have an antioxidant property,which is hypothesized to inhibit production of ROS and prevent cell injury.Thus,the present study was designed to determine the effects of PS on the hydrogen peroxide(H2O2)-induced oxidative cell damage in cultured human umbilical vein endothelial cells(HUVECs).In this experiment,HUVECs were obtained by collagenase perfusion of the large vein in the umbilical cord and cultured in medium M200 supplemented with low serum growth supplementation(LSGS).HUVECs were treated with various concentrations of H2O2(0-1000 μmol/L) and it was observed that 180 μmol/L H2O2 reduced cell viability by 50% as denoted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay.Using the above concentration as the positive control,the H2O2-induced HUVECs were concomitantly treated with various concentrations(100,150,250 and 300 μg/ml) of three different extracts(aqueous,methanol and hexane) of PS.Malondialdehyde(MDA),superoxide dismutase(SOD),catalase(CAT) and glutathione peroxidase(GPX) levels showed a significant increase(P0.05) in HUVECs compared to the negative control.However,PS extracts showed a protective effect on HUVECs from H2O2-induced cell apoptosis with a significant reduction in MDA,SOD,CAT and GPX levels(P0.05).Furthermore,PS had exhibited ferric reducing antioxidant power with its high phenolic content.Hence,it was concluded that PS plays a beneficial role in reducing oxidative stress in H2O2-induced HUVECs.     

Factors Affecting the Implementation of Argument in the Elementary Science Classroom. A Longitudinal Case Study

This longitudinal case study describes the factors that affect an experienced teacher’s attempt to shift her pedagogical practices in order to implement embedded elements of argument into her science classroom. Research data was accumulated over 2 years through video recordings of science classes. The Reformed Teacher Observation Protocol (RTOP) is an instrument designed to quantify changes in classroom environments as related to reform as defined by the National Research Council (National science education standards. Washington, DC: National Academy Press, 1996b) and the National Research Council (Fulfilling the promise: Biology education in the nation’s schools, Washington, DC: National Academy Press, 1990) and was used to analyze videotaped science lessons. Analysis of the data shows that there was a significant shift in the areas of teacher questioning, and student voice. Several levels of subsequent analysis were completed related to teacher questioning and student voice. The data suggests a relationship between these areas and the implementation of scientific argument. Results indicate that the teacher moved from a traditional, teacher-centered, didactic teaching style to instructional practices that allowed the focus and direction of the lesson to be affected by student voice. This was accomplished by a change in teacher questioning that included a shift from factual recall to more divergent questioning patterns allowing for increased student voice. As student voice increased, students began to investigate ideas, make statements or claims and to support these claims with strong evidence. Finally, students were observed refuting claims in the form of rebuttals. This study informs professional development related to experienced teachers in that it highlights pedagogical issues involved in implementing embedded elements of argument in the elementary classroom.