Covalently immobilized biomolecule gradient on hydrogel surface using a gradient generating microfluidic device for a quantitative mesenchymal stem cell study

Precisely controlling the spatial distribution of biomolecules on biomaterial surface is important for directing cellular activities in the controlled cell microenvironment. This paper describes a polydimethylsiloxane (PDMS) gradient-generating microfluidic device to immobilize the gradient of cellular adhesive Arg-Gly-Asp (RGD) peptide on poly (ethylene glycol) (PEG) hydrogel. Hydrogels are formed by exposing the mixture of PEG diacrylate (PEGDA), acryloyl-PEG-RGD, and photo-initiator with ultraviolet light. The microfluidic chip was simulated by a fluid dynamic model for the biomolecule diffusion process and gradient generation. PEG hydrogel covalently immobilized with RGD peptide gradient was fabricated in this microfluidic device by photo-polymerization. Bone marrow derived rat mesenchymal stem cells (MSCs) were then cultured on the surface of RGD gradient PEG hydrogel. Cell adhesion of rat MSCs on PEG hydrogel with various RGD gradients were then qualitatively and quantitatively analyzed by immunostaining method. MSCs cultured on PEG hydrogel surface with RGD gradient showed a grated fashion for cell adhesion and spreading that was proportional to RGD concentration. It was also found that 0.107–0.143 mM was the critical RGD concentration range for MSCs maximum adhesion on PEG hydrogel.     

Peer victimization in children with Attention‐Deficit/Hyperactivity Disorder

This study explored peer victimization in 9‐ to 14‐year‐old children with and without Attention‐Deficit/Hyperactivity Disorder (ADHD). The sample comprised 104 children, 52 of whom had a previous ADHD diagnosis. Children with ADHD had higher overall rates of self‐reported victimization by peers and parent‐ and teacher‐reported bullying behavior than did children without ADHD. The rates of victimization were especially high for girls with ADHD. Furthermore, children with ADHD reported higher frequencies of verbal, physical, and relational victimization than did children without ADHD. When data were pooled from children, parents, and teachers, children with ADHD were categorized as victims, bullies, and bully/victims significantly more often than were children without ADHD. Parent ratings of ADHD symptoms predicted self‐reported victimization by peers. Neither parent‐rated anxious‐shy behaviors nor parent‐ and teacher‐rated social skills predicted victimization by peers over and above ADHD symptoms. Parent ratings of oppositional behavior mediated the relationship between ADHD symptoms and parent‐ and teacher‐rated bullying. © 2008 Wiley Periodicals, Inc.     

世界工厂必备--也谈协同软件PLM

在我们日常生活中所接触的，现代生活必不可少的产品当中，电子业的产品远远多于其他行业，对此，我们已经习以为常。电子业生产的器件和终端产品之多，令人惊叹。从最常见的手提电话、笔记本电脑、PDA、计算机和打印机等到那些虽不常见但却渗透了生活方方面面的联网设备、路由器、存储器等。     

重拾文学阅读的初衷——浅析“香港文学深度体验”计划的实践

阐明“香港文学深度体验”计划的构思,并详细介绍文学景点考察、学校经验分享会及文学夏令营的内容,藉此说明文学散步与文学阅读的关系,为推广文学阅读探寻更多可能。     

Group procedures and applications for developing sociocultural competencies among immigrants

If immigrants are to get the best results in theirsocial and work worlds, they must possess not only therelevant cultural information, but also the requisitebehavioural skills inherent in the novel social rolesthat people acquire as members of the new country. This paper argues that the preferred training modelfor developing such competencies is one which utilizesrole-based learning in groups and incorporates aspectsof group counselling theory and practice. Effectivefacilitators of these immigrant groups should beskilled group leaders competent in taking participantsthrough the four stages - alliance building, culturalmapping, coaching and practice, and contract setting - involved in teaching each of severalkey sociocultural competencies. Group leaders will need to performparticular types of task and maintenance functions,and facilitate the development of group inclusion,control, and trust. To achieve this, facilitators arerecommended to use a range of micro skills for groupleading, processing, and counselling.     

Validation of the Olympic Games Attitude Scale (OGAS): Evidence from Exploratory and Confirmatory Factor Analyses

There have been extensive studies of local residents’ perception and reaction to the impacts of mega events. However, there is limited empirical research on the social impacts that shape foreign attitudes toward the host country. The purpose of this study was to develop and validate the Olympic Games Attitude Scale (OGAS) to examine viewers’ perception of the Olympics hosting country. Participants (N = 483) were based on a convenience sample in a local community of the mid-Atlantic region in the United States. Results of the exploratory factor analysis identified four factors (economic advancement, image enhancement, community enrichment, and turmoil development) with a total variance of 67.59%. Confirmatory factor analysis showed that after removing one item, the 13-item OGAS provided a good fit to the data (comparative fit index [CFI] = .97; incremental fit index [IFI] = .97, standardized root mean square residual [SRMR] = .049; root mean square error of approximation [RMSEA] = .080). It is concluded that the OGAS is a valid measuring instrument for assessing viewers’ perception of hosting the Olympic Games.     

An evaluation of China’s Kindergarten quality rating system through the Chinese early childhood environment rating scale – the Zhejiang case

This study examined the effectiveness of one province’s Kindergarten Quality Rating System in differentiating quality levels using the Chinese Early Childhood Environment Rating Scale (CECERS). Results confirmed that, except for the difference between the Standard and Level-3 Kindergartens, the CECERS was successful in detecting the differences among various quality levels based on Space & Furnishing, Personal Care Routines, Curriculum Planning & Implementation, Whole-Group Instruction, Activities, Language-Reasoning, Guidance & Interactions, and Parents & Staff. The findings suggest combining the Standard and Level-3 Kindergartens to improve the efficacy and efficiency of the quality rating system. Moreover, to ensure a quality ECE for children from disadvantaged backgrounds, the findings suggest that the government must increase both the number of rural programs and the quality of local ECE programs, especially rural and private programs. Finally, practitioners are encouraged to use the CECERS as a tool for improving ECE quality and for ensuring a quality early childhood education for every child.     

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.