An optical counting technique with vertical hydrodynamic focusing for biological cells

A barrier in scaling laboratory processes into automated microfluidic devices has been the transfer of laboratory based assays: Where engineering meets biological protocol. One basic requirement is to reliably and accurately know the distribution and number of biological cells being dispensed. In this study, a novel optical counting technique to efficiently quantify the number of cells flowing into a microtube is presented. REH, B-lymphoid precursor leukemia, are stained with a fluorescent dye and frames of moving cells are recorded using a charge coupled device (CCD) camera. The basic principle is to calculate the total fluorescence intensity of the image and to divide it by the average intensity of a single cell. This method allows counting the number of cells with an uncertainty ±5%, which compares favorably to the standard biological methodology, based on the manual Trypan Blue assay, which is destructive to the cells and presents an uncertainty in the order of 20%. The use of a microdevice for vertical hydrodynamic focusing, which can reduce the background noise of out of focus cells by concentrating the cells in a thin layer, has further improved the technique. Computational fluid dynamics (CFD) simulation and confocal laser scanning microscopy images have shown an 82% reduction in the vertical displacement of the cells. For the flow rates imposed during this study, a throughput of 100–200 cells∕s is achieved.     

Standardized Testing + High-Stakes Decisions = Educational Inequity

Changes in assessment policy have increased standardized testing at provincial, national, and international levels, introduced testing at more grade levels, increased the reporting of test results, and attached more significance to those results. Advocates claim that testing will result in greater accountability in education. The research demonstrates that standardized testing has a negative impact on students, perpetuating and intensifying educational inequity through test bias and the misuse of test scores. Test results are increasingly being used to analyse policy, program, school, and teacher success, and they are being inappropriately used as "educational gatekeepers" to make important decisions about students, teachers, schools, and school systems. This paper focuses on how standardized testing is becoming the mechanism that facilitates many questionable education practices that contribute to educational inequity.     

Lessons learned from a community engagement initiative within Irish higher education

This paper focuses on a community–university partnership built around a programme of study co-created by residents of a disadvantaged community and situated, for the most part, within that community. The aim of this paper is to share lessons learned from this community engagement initiative, as identified through a research study which ran concurrent to the programme. The study involved 41 interviews (18 individual interviews and 23 focus groups) over a two-year period with 28 participants. Participants included students, lecturers and community and university stakeholders. The finding section focuses on the characteristics of the initiative which allowed it to positively impact those involved. The data indicated that (i) the authenticity of the partnership between the community and university, (ii) the suitability of the lecturers and (iii) the ability of the lecturers and management to adapt the programme to identified needs were all key to the success of the programme. The paper concludes with a discussion, incorporating relevant literature, regarding what can be learned from this programme for those interested in enacting truly engaged practice in Irish higher education.     

迈向学习型社会--运用ICT学习的全球挑战

知识时代的来临,在全世界提出了对学习型社会的新需求。“运用ICT进行学习”作为一种新的终身技能、新的学习理论、新的全球学习方式和新的学习工具格外引人瞩目。运用ICT来创造未来学习型社会存在着十大挑战。