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The role of mediating organizations for school reform: independent agents or district dependents?

This paper examines the role of mediating organizations in helping schools engage in whole school change as part of a school district's reform agenda. Specifically, it examines the Learning Community Program in Los Angeles, a programme designed by an external school reform organization, to assist schools in planning and implementing LEARN (Los Angeles Educational Alliance for Restructuring Now). The programme's success is shaped by the district and school contexts in which it operates. As mediating agent, the Learning Community Program must balance the challenges facing the schools ‐‐ particularly their readiness to engage in reform ‐‐ with the demands of the district for scale, accountability and resources. As it does so, it faces the challenges of maintaining program flexibility, building sustainable changes, and preserving its organizational independence. These pressures generate three central dilemmas and threaten to undermine the success of the district's reform and the Learning Community Program ‐‐ scale versus sustainability, district mandates versus site autonomy, and organizational independence versus survival. It concludes that mediating agencies can be constrained by their dependence on policymakers for critical resources.     

Three-dimensional printed millifluidic devices for zebrafish embryo tests

Implementations of Lab-on-a-Chip technologies for in-situ analysis of small model organisms and embryos (both invertebrate and vertebrate) are attracting an increasing interest. A significant hurdle to widespread applications of microfluidic and millifluidic devices for in-situ analysis of small model organisms is the access to expensive clean room facilities and complex microfabrication technologies. Furthermore, these resources require significant investments and engineering know-how. For example, poly(dimethylsiloxane) soft lithography is still largely unattainable to the gross majority of biomedical laboratories willing to pursue development of chip-based platforms. They often turn instead to readily available but inferior classical solutions. We refer to this phenomenon as workshop-to-bench gap of bioengineering science. To tackle the above issues, we examined the capabilities of commercially available Multi-Jet Modelling (MJM) and Stereolithography (SLA) systems for low volume fabrication of optical-grade millifluidic devices designed for culture and biotests performed on millimetre-sized specimens such as zebrafish embryos. The selected 3D printing technologies spanned a range from affordable personal desktop systems to high-end professional printers. The main motivation of our work was to pave the way for off-the-shelf and user-friendly 3D printing methods in order to rapidly and inexpensively build optical-grade millifluidic devices for customized studies on small model organisms. Compared with other rapid prototyping technologies such as soft lithography and infrared laser micromachining in poly(methyl methacrylate), we demonstrate that selected SLA technologies can achieve user-friendly and rapid production of prototypes, superior feature reproduction quality, and comparable levels of optical transparency. A caution need to be, however, exercised as majority of tested SLA and MJM resins were found toxic and caused significant developmental abnormalities in zebrafish embryos. Taken together, our data demonstrate that SLA technologies can be used for rapid and accurate production of devices for biomedical research. However, polymer biotoxicity needs to be carefully evaluated.