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.     

Defining'science-based targets'

The 2015 Paris Agreement to keep global warming well below 2℃above pre-industrial levels and aim towards limiting warming to 1.5℃marked a wa-tershed in planetar...     

Boundary Crossing and the Professional Learning of Teacher Educators in New International Contexts

In this collaborative self-study, two teacher educators examine their experiences of working in new international contexts and the impact of those experiences on their professional learning and identities. Mandi moved from a major research university in one country to another, while Judy co-led a group of pre-service teachers on an international practicum for three weeks each year for three years. Using the concept of boundary crossing as a theoretical and analytical framework, each teacher educator identified a boundary-related critical incident or experience that occurred during her work in new international contexts. Through individual and collaborative analysis of their critical incidents, they found that working as a teacher educator in new international contexts involves the crossing and re-crossing of multiple personal, professional, linguistic and cultural boundaries. Working in these boundary spaces involved learning how to negotiate new kinds of relationships with colleagues and students, manage changed roles and responsibilities and, ultimately, a search for a renewed sense of self, as each sought to understand herself differently within a new professional context.     

Transformative Learning: First-Year MSW Students' Reactions to,and Experiences in,Gerontological Field Placements

We present findings from interviews with 17 first-year MSWs assigned to gerontological placements undertaken before beginning—and again as they neared completion—of practicum. All respondents, even those most positive and negative at beginning of placement, report a reduction in stereotypes, improved appreciation of older adults’ capacities and strengths, and increased skills in working with this population. All but one respondent reports increased likelihood of pursuing a position working with older adults as a result of exposure through field placement. Specific factors reported by students to influence their decision as well as implications for social work education are discussed.     

Using the College Outcome Measures Project to measure college outcomes

This article describes one institution's use of the College Outcome Measures Project (COMP) in comparing outcomes for graduates of traditional and non-traditional programs. The study was designed to answer three questions concerning the use of COMP in evaluating traditional and non-traditional programs. Results obtained in a study of 96 University of Minnesota graduating seniors suggest greater potential usefulness in distinguishing among institutions than in comparing outcomes of programs within an institution. The authors conclude that as new approaches and instruments for measuring college outcomes become available, criteria for instrument selection need to be shared among individuals charged with conducting outcome studies.     

False‐Belief Understanding and Social Preference Over the First 2 Years of School: A Longitudinal Study

The role of false belief in establishing children's social relationships during the transition to school was examined and compared to other social cognitive constructs. One hundred and fourteen 5‐year‐olds were recruited during their 1st year of school (Time 1); 106 children were retained 1 year later. False belief, emotion expression recognition, empathy, verbal ability, and peer‐rated social preference were measured at both times. False belief at Time 1 had a direct influence on concurrent social preference, over and above the influence of emotion expression recognition and empathy. False belief made no independent contribution to later social preference accounting for stability in social preference. The role of social cognitive development is discussed with respect to how children establish and maintain their position in a peer group.     

Developing Scientific Literacy in a Primary School

The science education literature demonstrates that scientific literacy is generally valued and acknowledged among educators as a desirable student learning outcome. However, what scientific literacy really means in terms of classroom practice and student learning is debatable due to the inherent complexity of the term and varying expectations of what it means for learning outcomes. To date the teacher voice has been noticeably absent from this debate even though the very nature of teacher expertise lies at the heart of the processes which shape students' scientific literacy. The research reported in this paper taps into the expertise of (participating) primary teachers by analyzing the insights and thinking that emerged as they attempted to unravel some of the pedagogical complexities associated with constructing an understanding of scientific literacy in their own classrooms. The research examines the processes and structures within one primary school that were created to provide conditions to allow teachers to explore and build on the range of ideas that presently inform the scientific literacy debate. The research reports these teachers' views and practices that shaped their actions in teaching for scientific literacy.     

Kinematic,kinetic and EMG analysis of four front crawl flip turn techniques

This study aimed to analyse the kinematic, kinetic and electromyographic characteristics of four front crawl flip turn technique variants. The variants distinguished from each other by differences in body position (i.e. dorsal, lateral, ventral) during rolling, wall support, pushing and gliding phases. Seventeen highly trained swimmers (17.9 ± 3.2 years old) participated in interventional sessions and performed three trials of each variant, being monitored with a 3-D video system, a force platform and an electromyography (EMG) system. Studied variables: rolling time and distance, wall support time, push-off time, peak force and horizontal impulse at wall support and push-off, centre of mass horizontal velocity at the end of the push-off, gliding time, centre of mass depth, distance, average and final velocity during gliding, total turn time and electrical activity of Gastrocnemius Medialis, Tibialis Anterior, Biceps Femoris and Vastus Lateralis muscles. Depending on the variant, total turn time ranged from 2.37 ± 0.32 to 2.43 ± 0.33 s, push-off force from 1.86 ± 0.33 to 1.92 ± 0.26 BW and centre of mass velocity during gliding from 1.78 ± 0.21 to 1.94 ± 0.22 m · s^?1. The variants were not distinguishable in terms of kinematical, kinetic and EMG parameters during the rolling, wall support, pushing and gliding phases.