INTERLOCKED PROBLEM POSING AND CHILDREN’S PROBLEM POSING PERFORMANCE IN FREE STRUCTURED SITUATIONS

The aim of this study is to explore the mathematical problem posing performance of students in free structured situations. Two classes of fifth grade students (N??=??30) were randomly assigned to experimental and control groups. The categories of the problems posed in free structured situations by the 2 groups of students were studied through inductive and deductive content analysis and coded in categories before and after a 5-week treatment. The treatment for the experimental group was the Interlocked Problem Posing Instruction in which student cognitive engagement was emphasized, and for the control group, it was Traditional Problem Posing Instruction. The results revealed that the experimental group students posed more solvable, reasonable and start-unknown problems than the control group students after the treatment.     

Internet Use and Social Networking Among Middle Aged and Older Adults

In this study, the associations between Internet use and the social networks of adults over 50 years of age were examined. A sample (n = 2284) from the 2004 wave of the Health and Retirement Survey was used. In regression models considering a number of control variables, frequency of contact with friends, frequency of contact with family, and attendance at organizational meetings (not including religious services) were found to have a significant positive association with Internet use for adults over 50. Results add to the body of research that suggests Internet use can strengthen social networks, looking specifically at adults over 50.     

Microfluidic immunomagnetic cell separation using integrated permanent micromagnets

In this paper, we demonstrate the possibility to trap and sort labeled cells under flow conditions using a microfluidic device with an integrated flat micro-patterned hard magnetic film. The proposed technique is illustrated using a cell suspension containing a mixture of Jurkat cells and HEK (Human Embryonic Kidney) 293 cells. Prior to sorting experiments, the Jurkat cells were specifically labeled with immunomagnetic nanoparticles, while the HEK 293 cells were unlabeled. Droplet-based experiments demonstrated that the Jurkat cells were attracted to regions of maximum stray field flux density while the HEK 293 cells settled in random positions. When the mixture was passed through a polydimethylsiloxane (PDMS) microfluidic channel containing integrated micromagnets, the labeled Jurkat cells were selectively trapped under fluid flow, while the HEK cells were eluted towards the device outlet. Increasing the flow rate produced a second eluate much enriched in Jurkat cells, as revealed by flow cytometry. The separation efficiency of this biocompatible, compact micro-fluidic separation chamber was compared with that obtained using two commercial magnetic cell separation kits.     

The effect of a programming tool scratch on the problem-solving skills of middle school students

Education and Information Technologies - Problem-solving is one of the most important twenty-first-century skills and should be acquired at an early age. Since programming is a kind of...     

IMPACT OF INTERACTIVE MULTIMEDIA MODULE WITH PEDAGOGICAL AGENTS ON STUDENTS’ UNDERSTANDING AND MOTIVATION IN THE LEARNING OF ELECTROCHEMISTRY

The Electrochemistry topic is found to be difficult to learn due to its abstract concepts involving macroscopic, microscopic, and symbolic representation levels. Studies have shown that animation and simulation using information and communication technology (ICT) can help students to visualize and hence enhance their understanding in learning abstract chemistry topics. As a result, an interactive multimedia module with the pedagogical agent (IMMPA) named the EC Lab (Electrochemistry Lab) was developed in order to assist students in the learning of Electrochemistry topics. A non-equivalent pretest–posttest control group design investigation was carried out in order to gauge the effect of the IMMPA EC Lab on students’ understanding and motivation in the learning of Electrochemistry. Some 127 Form Four students from two secondary schools in one of the districts in Malaysia were involved in the study. Each school had one treatment group and one control group taught by the same Chemistry teacher. Instruments involved were a pre- and posttest, a pre- and post-motivation questionnaire, and the IMMPA EC Lab. Results showed a significant difference between the control groups and treatment groups in the understanding of concepts in the learning of Electrochemistry.     

从考古资料试析西域民族丧葬习俗的演变及文化渊源

本文根据诸多考古资料及历史文献,探讨西域古代民族在信仰伊斯兰教之前的萨满教、袄教、佛教等不同时期的丧葬习俗及特征,并对它所反映的文化背景进行论述。     

One Science Teacher’s Professional Development Experience: A Case Study Exploring Changes in Students’ Perceptions of Their Fluency with Innovative Technologies

The purpose of this case-study is to narrate a secondary science teacher’s experience of his professional development (PD) education and training in innovative technologies (IT) in the context of engaging students in environmental research projects The sources from which the narrative is derived include (1) the science teacher’s reflective reports during three summer institute programs and (2) the science teacher’s reflective reports while subsequently engaging students in IT-embedded environmental research projects in his classroom. The science teacher’s explanations for changes in students’ perception of their IT fluency illuminate his personal narrative. The science teacher attributed his growth and significant changes in students’ perceptions of their IT fluency to the following mechanisms: (a) a personal commitment to developing his own and his students’ IT abilities in the context of doing environmental research projects, and (b) an increase in class time devoted to science education due to school-time scheduling policy. The study implies that immersive professional development opportunities have the potential to produce significant increases in students’ perceptions of their IT fluency.     

Changes in Attitudes Towards Science–Technology–Society of Pre-service Science Teachers

This research focuses on use of a triadic teaching approach in a science–technology–society (STS) course designed for future science teachers for middle schools in Turkey. Forty-three pre-service science teachers were enrolled in a semester-long course organized around issues students identified and used throughout the semester. The triadic teaching approach includes library-online searches that lead the students to design and conduct investigations, to carrying out mini-scientific symposia, and to preparing and conducting poster presentations open to the entire student body and faculty. The results of a 30-item Likert scale, administered to the students as a pretest and a posttest, indicated that there were significant increases in positive attitudes towards STS issues from the beginning to the end of the study. Individual interviews were also conducted with the students to determine the individual effects of each component of the triadic teaching approach on their attitudes towards STS issues. All aspects of the new approach provided significant contributions to the development of more positive attitudes among the students towards STS via interviews and on all sub-scales of a survey administered that include: (1) pupil interest in STS issues; (2) teacher interest in STS issues; (3) general perceptions regarding importance of STS issues.

High School Students’ Reasons for Their Science Dispositions: Community-Based Innovative Technology-Embedded Environmental Research Projects

Research in Science Education - The purpose of this investigation was to qualitatively describe high school students’ reasons for their science dispositions (attitude, perception, and...     

红茶、绿茶、茯茶的茶末中多糖的提取及含量测定

采用苯酚-硫酸法，以葡萄糖作为标准品，对茶中多糖进行提取和含量分析．结果显示在85℃下3％碳酸钠溶液中提取可得最大值，多糖含量可达3％～8％．表明采取比色法测定多糖含量简单、可靠．