Organosilane deposition for microfluidic applications

Treatment of surfaces to change the interaction of fluids with them is a critical step in constructing useful microfluidics devices, especially those used in biological applications. Silanization, the generic term applied to the formation of organosilane monolayers on substrates, is both widely reported in the literature and troublesome in actual application for the uninitiated. These monolayers can be subsequently modified to produce a surface of a specific functionality. Here various organosilane deposition protocols and some application notes are provided as a basis for the novice reader to construct their own silanization procedures, and as a practical resource to a broader range of techniques even for the experienced user.     

Through a different lens: bridging the expectation–perception (quality) divide in higher education

The paper draws on the underpinnings of SERVQUAL (a Service Quality measurement model) and explores three key aspects of service standards as adopted by an Engineering School in Singapore: customer orientation, course design/delivery and support services. Qualitative methodology was employed and data were collected by means of structured in-depth interviewing with 24 respondents. Findings reveal that the way students are perceived, whether as customers or products, has a direct influence on the type of learning dynamics developed both inside and outside the classroom. Service quality needs to be evaluated on the basis of an integrated experience within a network of learning spaces created to promote dialogue, inquiry and reflection. By looking at the correlations of two sets of findings measuring gaps and perceived performance from a foreign study, a number of attributes were uncovered, illuminating our conceptual framework. It reveals another dimension of SERVQUAL such that the internal gaps would be made more explicit through the lenses of performance-based measures.     

Exploring and learning from failure in facilitation

ABSTRACT

Research in academic development more often articulates stories of success than of failure in our practice. Using a self-study methodology involving written reflections and analysis of recorded conversations, this article explores how two mid-career developers define and learn from feelings of failure in the context of group facilitation. Through reflection and discussion as critical friends, we identified a series of tensions that shape our work and our identities as developers. How we reflect upon and navigate through these potentially uncomfortable places has implications for how we reframe our feelings of failure and evolve our practice.     

The effect of leg kick on sprint front crawl swimming

Abstract

The aim of this study was to examine the influence of leg kick on the pattern, the orientation and the propulsive forces produced by the hand, the efficiency of the arm stroke, the trunk inclination, the inter-arm coordination and the intra-cyclic horizontal velocity variation of the hip in sprint front crawl swimming. Nine female swimmers swam two maximal trials of 25 m front crawl, with and without leg kick. Four camcorders were used to record the underwater movements. Using the legs, the mean swimming velocity increased significantly. On the contrary, the velocity and the orientation of the hand, the magnitude and the direction of the propulsive forces, as well as the Froude efficiency of the arm stroke were not modified. The hip intra-cyclic horizontal velocity variation was also not changed, while the index of coordination decreased significantly. A significant decrease (13%) was also observed in the inclination of the trunk. Thus, the positive effect of leg kick on the swimming speed, besides the obvious direct generation of propulsive forces from the legs, could probably be attributed to the reduction of the body’s inclination, while the generation of the propulsive forces and the efficiency of the arm stroke seem not to be significantly affected.     

Microfluidic size separation of cells and particles using a swinging bucket centrifuge

Biomolecular separation is crucial for downstream analysis. Separation technique mainly relies on centrifugal sedimentation. However, minuscule sample volume separation and extraction is difficult with conventional centrifuge. Furthermore, conventional centrifuge requires density gradient centrifugation which is laborious and time-consuming. To overcome this challenge, we present a novel size-selective bioparticles separation microfluidic chip on a swinging bucket minifuge. Size separation is achieved using passive pressure driven centrifugal fluid flows coupled with centrifugal force acting on the particles within the microfluidic chip. By adopting centrifugal microfluidics on a swinging bucket rotor, we achieved over 95% efficiency in separating mixed 20 μm and 2 μm colloidal dispersions from its liquid medium. Furthermore, by manipulating the hydrodynamic resistance, we performed size separation of mixed microbeads, achieving size efficiency of up to 90%. To further validate our device utility, we loaded spiked whole blood with MCF-7 cells into our microfluidic device and subjected it to centrifugal force for a mere duration of 10 s, thereby achieving a separation efficiency of over 75%. Overall, our centrifugal microfluidic device enables extremely rapid and label-free enrichment of different sized cells and particles with high efficiency.     

Producing Scientific Explanations in Physics—a Multimodal Account

Research in Science Education - This study focuses on the relationship between students’ use of language resources and their conceptualisation of phenomena in producing scientific...     

Exploring new potentials of blogs for learning: Can children use blogs for personal information management (PIM)?

This study explores the use of blogs for personal information management (PIM) as a learning tool that could bring increased efficiency and academic self‐efficacy for carrying out learning tasks. In order to identify the uses and effects of using blogs for PIM by children, a control group that used personal spaces within the class website and an experiment group that used personal blogs both posted their resources online (personal space within class website or blog) to use in their class assignments. Comparison of both groups demonstrate that when children used blogs for PIM their academic their self‐efficacy increased, their personalization of blogs made it easier to use collected resources and they became more actively engaged in tasks as well. This study suggests that using individual blogs for PIM can create personally meaningful contexts of learning for children.