Mixing enhancement in microfluidic channel with a constriction under periodic electro-osmotic flow

We present a new approach to enhance mixing in T-type micromixers by introducing a constriction in the microchannel under periodic electro-osmotic flow. Two sinusoidal ac electric fields with 180° phase difference and similar dc bias are applied at the two inlets. The out of phase ac electric field induces oscillation of fluid interface at the junction of the two inlet channels and the constriction. Due to the constriction introduced at the junction, fluids from these two inlets form alternative plugs at the constricted channel. These plugs of fluids radiate downstream from the constriction into the large channel and form alternate thin crescent-shaped layers of fluids. These crescent-shaped layers of fluids increase tremendously the contact surface area between the two streams of fluid and thus enhance significantly the mixing efficiency. Experimental results and mixing mechanism analysis show that amplitude and frequency of the ac electric field and the length of the constriction govern the mixing efficiency.     

Educating the Young Mathematician: The Twentieth Century and Beyond

Educational programs for young children emerged reasonably early in the history of the United States of America. The movements of Child-Centered Education, the Nursery School, the Project Method, Curriculum Reform, and contemporary research have all influenced mathematics in early childhood education. The Froebelian kindergarten and the Montessori Casa die Bambini (Children’s House) included approaches to teaching mathematics. This article reviews the history of mathematics education in relation to the history of early childhood education from the turn of the twentieth century. It also discusses how research in mathematics education attempted to gain its own identity. Throughout history, researchers have identified mathematics issues and addressed them, defining the field, and generating a cadre of mathematics researchers.     

Teacher management and educational reforms: Paradigm shifts

In the past 15 years, numerous reforms and initiatives in many countries in the Asia-Pacific region have aimed to change education and promote new learning to prepare the new generation for the future. Unfortunately, despite good intentions and huge investments of resources, many of these reforms have been found to be ineffective and unsustainable—if they succeed at all. Reflecting on the trends and waves of educational reform in the Asia-Pacific region, this paper introduces an international lesson on the emerging syndrome of educational reform across the region and illustrates its negative impacts on teacher ecology and teacher management. Then, the paper outlines the implications of this lesson and of a study of the world’s best-performing educational systems, using them to develop a holistic approach to managing teachers and planning for their sustainable professional development. Finally, it highlights the paradigm shifts in teacher management, reviewing the three waves of educational reform in the last two decades, and draws further implications for formulating teacher management policies in ongoing and future educational reforms to support students’ new learning and sustainable development.     

Public service reform in education: why is progress so slow?

This case study examines why public‐sector reform in education often fails to deliver expected performance gains. Longitudinal evidence from a secondary comprehensive located in a former coalfield is used to identify constraints that frustrate government policies. Although the head and senior staff at Norcross School adopted transformational, distributed modes of leadership and implemented a rigorous target‐setting regime, the expected increase in effectiveness has not materialised. This disappointment is explained in relation to the flawed assumptions of the result‐driven effectiveness agenda, the resistance arising from continuing structural inequalities in society, and the hyperactive complexity of New Labour’s approach to managing public services. The study concludes that as the assessment regime in England provides an unreliable picture of student progress, there is no stable basis for judging the success of reform, particularly when perceived improvements in student experience are qualitative in nature.     

Parental concerns regarding a centre-based early intervention programme for Down syndrome in Malaysia: a case study

This qualitative study provides information on the concerns faced by parents having children with Down syndrome in a centre-based Early Intervention Programme in Malaysia and how they coped with these concerns. Semi-structured interviews were conducted with a total of five parents and two special educators. The interview and observation findings indicate that there are numerous concerns faced by parents, such as the child’s uncertain future, teacher training, family involvement, expansion of services, support services, lack of information and resources, inconsistency of language used, increase in fees, and changes in lifestyle. The study has also revealed unmet needs of special children, for example, time duration, music therapy and the facilities provided. Recommendations have also been suggested for further needed improvement in the Early Intervention Programme.     

Effects of increased participation on veteran running performance

Contrary to elite performance that is approaching an asymptote, recent analyses suggested a trend for improvement in veterans. This might be attributable to a disproportionate increase in older age-group participation. We extracted 26 years (1987–2012) of men’s results of a running event in Switzerland, “La Course de l’Escalade” (7.25 km). We investigated trends in performance by five-year age-groups, taking the 10, 20, 30, and 50 fastest in each group, and then the 1^st, 5^th, and 10^th percentiles. Taking the 10, 20, 30 or 50 fastest runners there was a trend for improvement ranging from 0.07 to 0.22 min·year^?1 (p < .0001; 95% CI ?0.083 to ?0.049 and p < .0001; 95% CI ?0.250 to ?0.196 respectively) in the elder age-groups. Taking the 1^st, 5^th, and 10^th percentiles there were no trends for improvement, and actual deteriorations up to 0.13 (p < .0001; 95% CI +0.119 to +0.138) min·year^?1. Mixed-effect models with repeated measures for runners, confirmed a global deteriorating trend with an estimate of +0.11 min·year^?1 (p < .0001; 95% CI +0.107 to +0.116). The results suggest that increases in performance in older runners arise from modifications of sampling from a growing population.     

Words On Play

In his article, ‘Recovering Humanity: Movement, Sport, and Nature’, Doug Anderson addresses the place of endurance sport, or more generally sport at large, as a potential catalyst for the good life. Anderson contrasts transcendental themes of Henry David Thoreau and Ralph Waldo Emerson with the pragmatic claims of William James and John Dewey, who focus on human possibility and growth. Our aim is to pursue the pragmatic line of thought championed by James and Dewey as a contrasting but not mutually exclusive motive to Anderson’s analysis. We contend that movement can provide humanizing possibilities even more pronounced for those subscribing to pragmatic themes (i.e., growth and the strenuous mood). We will use running and cycling to demonstrate how the strenuous mood enhances the possibility for this humanizing condition. Specifically, we argue that moving in a committed fashion allows us to deepen our relationship with the respective practice and thus opens the possibilities for ‘recovering our humanity’.     

Attentional focus effects on sprint start performance as a function of skill level

Abstract

Several researchers have demonstrated that an external focus of attention (about movement’s effects) during movement execution allowed better performances and learning of various motor tasks than an internal focus of attention (about movement itself). However, attentional focus effects have not been studied in tasks requiring explosive actions preceded by fast reaction time to a signal, such as a sprint start. We hypothesised that the beneficial effect of external focus of attention would be observed in the different stages of the sprint start (i.e. reaction time, block clearance and running) for both expert and novice sprinters. Novice and expert sprinters performed sprint starts followed by a 10 m sprint under three conditions: external focus instructions; internal focus instructions; and neutral instructions. The reaction time and the running time were significantly shorter in the external focus condition than in the internal focus condition, for both expert and novice participants. These results confirm the beneficial effect of an external focus of attention on the speed of movement execution. Moreover, they revealed that attentional focus influences movement preparation. Several hypotheses are proposed to account for these results, with reference to the processes that could be responsible for the observed effects.     

Impressions of ICOTS II

The following short contributions are from people who attended the Second International Conference on Teaching Statistics held in Victoria, August 1986     

A General Framework for the Validation of Embedded Formative Assessment

In educational practice, test results are used for several purposes. However, validity research is especially focused on the validity of summative assessment. This article aimed to provide a general framework for validating formative assessment. The authors applied the argument‐based approach to validation to the context of formative assessment. This resulted in a proposed interpretation and use argument consisting of a score interpretation and a score use. The former involves inferences linking specific task performance to an interpretation of a student's general performance. The latter involves inferences regarding decisions about actions and educational consequences. The validity argument should focus on critical claims regarding score interpretation and score use, since both are critical to the effectiveness of formative assessment. The proposed framework is illustrated by an operational example including a presentation of evidence that can be collected on the basis of the framework.