Magnetic microbead transport during resistive pulse sensing

Tunable resistive pulse sensing (TRPS) experiments have been used to quantitatively study the motion of 1 μm superparamagnetic beads in a variable magnetic field. Closed-form theory has been developed to interpret the experiments, incorporating six particle transport mechanisms which depend on particle position in and near a conical pore. For our experiments, calculations indicate that pressure-driven flow dominates electrophoresis and magnetism by a factor of ∼100 in the narrowest part of the pore, but that magnetic force should dominate further than ∼1 mm from the membrane. As expected, the observed resistive pulse rate falls as the magnet is moved closer to the pore, while the increase in pulse duration suggests that trajectories in the half space adjacent to the pore opening are important. Aggregation was not observed, consistent with the high hydrodynamic shear near the pore constriction and the high magnetization of aggregates. The theoretical approach is also used to calculate the relative importance of transport mechanisms over a range of geometries and experimental conditions extending well beyond our own experiments. TRPS is emerging as a versatile form of resistive pulse sensing, while magnetic beads are widely used in biotechnology and sensing applications.     

The Trouble With Stereotypes: A Reply To Morris

This article presents a critique of two arguments made by S.P. Morris in his recent piece ‘The Trouble with Mascots’. The first argument is that the wrong of mascots is rooted in the falsity of the stereotyping generalizations that they create and perpetuate. The second is that when the group provides the name to itself (as with the Fighting Irish of Notre Dame), it is, in light of that fact, no less morally objectionable. These two arguments are related, for the second would be correct if falsity were in fact the issue. As I argue, however, if we take a different view of the problem that generalizations present, the moral relevance of who does the naming becomes clear.     

The association between mathematics pedagogy and learners’ dispositions for university study

We address the current concerns about teaching‐to‐the‐test and its association with declining dispositions towards further study of mathematics and the consequences for choice of STEM subjects at university. In particular, through a mixed study including a large survey sample of over 1000 students and their teachers, and focussed qualitative case studies, we explored the impact of ‘transmissionist’ pedagogic practices on learning outcomes. We report on the construction and validation of a scale to measure teachers’ self‐reported pedagogy. We then use this measure in combination with the students’ survey data and through regression modelling we illustrate significant associations between the pedagogic measure and students’ mathematics dispositions. Finally, we discuss the potential implications of these results for mathematics education and the STEM agenda.     

UNIVERSITY STUDENTS’ VIEWS OF THE ROLE OF MATHEMATICS IN THEIR FUTURE

We report on an international study about mathematics students’ ideas of how they will use mathematics in their future study and careers. This builds on our previous research into students’ conceptions of mathematics. In this paper, we use data from two groups of students studying mathematics: those who participated in an in-depth interview and those who completed an open-ended questionnaire. We found that their responses could be grouped into four categories: don’t know; procedural skills; conceptual skills; and professional skills. Although some students held clear ideas about the role of mathematics, many were not able to articulate how it would be used in their future. This has implications for their approach to learning and our approach to teaching.     

Effects of the Shift to English-Only Instruction on College Outcomes: Evidence from Central Asia

Abstract

English-only college education in non-English speaking countries is a rapidly growing phenomenon that has been dubbed as the most important trend in higher education internationalization. Despite worldwide popularity, there is little empirical evidence about how the transition to English-only instruction affects students’ academic outcomes. Using a natural experiment at a selective university in Central Asia and a difference-in-differences strategy, we estimate the causal effect of switching to English-only instruction on students’ college outcomes. We find that the introduction of English-only instruction led to a decrease of GPAs and probability of graduation and an increase in the number of failed course credits. Although negative, the effects were short-lived. The difference-in-differences estimates and the examination of potential mechanisms suggest that at least in selective universities in non-English speaking countries, the switch to English-only instruction may affect college outcomes negatively at the time of transition but may not necessarily imply longer-run negative effects.     

Assessment

Introduction TERMINOLOGY AND KEY CONCEPTS The term assessment refers to a variety of ways of collecting information on a learner‘ s language ability or achievement. Although testing and assessment are often used interchangeably, the latter is an umbrella term encompassing measurement instruments administered on a ‘one-off‘ basis such as tests, as well as qualitative methods of monitoring and recording student learning such as observation, simulations of project work. Assessment is also distinguished from...     

Undergraduate non-completion rates: a comment

Our comment is a response to a recent paper in this Journal on non-completion rates in UK universities (Johnes and Taylor 1989). The causal inferences which that paper draws are ill-founded because they are based on data aggregated to university level. Individual-level data are essential, and data on other levels may also be necessary. We make other criticisms, and also comment on implications for performance indicators.     

Science discipline knowledge in primary teacher education: Responses to the discipline review of teacher education in mathematics and science

This paper describes a study of primary teacher educators reaction to those aspects of theDiscipline Review of Teacher Education in Mathematics and Science dealing with early childhood and primary pre-service teacher education. Interviews with two of the authors of the Review are also reported.     

Extended households and the life course of young mothers: understanding the associations using a sample of mothers with premature, low birth weight babies

This paper examined whether the greater average schooling and employment, and lower parenting competence, of young mothers who reside with adult relatives reflect preexisting differences versus potential causal mechanisms. The sample included 554 young mothers (ages 13 to 25; nearly two thirds African American) from the Infant Health and Development Program (IHDP) a random-assignment intervention study of premature, low birth weight babies followed 8 times from birth to age 3. Ordinary least squares, fixed-effects, and random-effects models indicated that young mothers of low birth weight babies sorted into extended households based on preexisting characteristics that were correlated with their lower parenting skills and knowledge. In contrast, coresidence predicted greater schooling or employment across models, with some variations for different subgroups.