Bandpass sorting of heterogeneous cells using a single surface acoustic wave transducer pair

Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes.     

Teachers’ resilience and well-being: a role for educational psychology

The retention and resilience of teachers are subject to many influences. Children’s behaviour is often cited as a major source of stress for teachers and a challenge to their resilience. We suggest that an understanding of teachers’ attributions and efficacy beliefs may provide the foundations for work to support teachers. We outline findings from research that has examined teachers’ attributions for the causes of children’s misbehaviour, teachers’ beliefs in their efficacy as classroom managers of children’s behaviour as well as how, in principle, such beliefs may be supported and enhanced. We also relate these findings to those associated with educational and developmental outcomes for children. We conclude with some illustrative evidence of ways (involving consultation and other interventions) that applied psychologists have contributed to the professional well-being and resilience of teachers.     

Individual differences in decision-making and confidence: capturing decision tendencies in a fictitious medical test

Decision-making is a complex process that is largely studied from an experimental perspective or in specific organizational contexts. As such, no generalizable framework exists with which to study decision-making from an individual differences perspective for predictive/selection purposes. By generalising a context-specific decision model proposed by Koriat and Goldsmith (1996), the focus of this research was to therefore test a novel framework for studying individual differences in decision-making tendencies. Utilising this framework within a fictitious Medical Decision-Making Test (MDMT) yielded five novel variables that provided unique insight into individuals’ decision tendencies: Optimal, Realistic, Incompetent, Hesitant and Congruent. Metacognitive confidence and its calibration (bias and CAQ) were used as predictor variables to validate this framework. One hundred ninety-three undergraduate students completed the MDMT and three cognitive ability tests with confidence ratings, a personality questionnaire, and the Need for Closure questionnaire. All decision tendency variables demonstrated excellent internal consistency and were predicted by the metacognitive variables incrementally to the remaining variables as hypothesized. Additionally, the metacognitive indices were found to generalize across the decision-making and cognitive tests. The results imply that this novel framework and MDMT reliably capture individuals’ decision behaviour that shares a meaningful relationship with their general confidence and calibration.     

Demystifying Critical Reflection: Defining criteria for assessment

Many university teachers in the social sciences and humanities, especially those interested in emancipatory educative practices, wish to see their students develop a capacity for critical reflection, considered essential for the development of higher-order thinking. However, critical reflection is rarely precisely defined nor are clear indications given about how teachers can develop appropriate criteria for assessing how well students reflect. This paper offers a framework for identifying indicators of a capacity for critical reflection in the social sciences, as well as demonstrating how criteria can be developed for assessing students' capability for critical reflection, including making distinctions between reflection on values, beliefs and assumptions. It is argued that offering clear criteria can assist in providing guidance to both students and teachers in developing critically reflective capacities.     

A Reaction to Mehrens's NCME Presidential Address

As a state level measurement specialist, Tom notes that some psychometricians always have a list of reasons test data cannot be used to enhance the quality of educational decisions. He welcomes Bill's exhortation to be hope-oriented and calls on measurement specialists to provide decision makers with practical, understandable ways to best use test data.