‘Even though it might take me a while, in the end, I understand it’: a longitudinal case study of interactions between a conceptual change strategy and student motivation, interest and confidence

Although there have been many investigations of the social, motivational, and emotional aspects of conceptual change, there have been few studies investigating the intersection of these factors with cognitive aspects in the regular classroom. Using a conceptual change approach, this case study reports experiences of a student of low to average prior attainment who achieved high levels of conceptual gains in five science topics over a two-year period. Her experience in the cognitive, social and affective domains was probed through analysis of interviews, student artefacts, video recordings of classroom learning, pre/post-tests and questionnaire results. For this student, peripheral or incidental persuasion of belonging to a supportive small group initially led to greater engagement with the construction of understanding through production of multiple student-generated representations, resulting in improved self-confidence and high levels of conceptual change. Evidence of transfer from performance to mastery approach goals, adoption of positive activating emotions and increased interest in science were observed. This study highlights that adoption of a multidimensional conceptual change approach with judicious organisation of small groups to support construction of verbal, pictorial and written representations of understanding may bring about changes in motivational stance, self-confidence and emotions to maximise conceptual change

Imaging of Ventricular Fibrillation and Defibrillation: The Virtual Electrode Hypothesis

Ventricular fibrillation is the major underlying cause of sudden cardiac death. Understanding the complex activation patterns that give rise to ventricular fibrillation requires high resolution mapping of localized activation. The use of multi-electrode mapping unraveled re-entrant activation patterns that underlie ventricular fibrillation. However, optical mapping contributed critically to understanding the mechanism of defibrillation, where multi-electrode recordings could not measure activation patterns during and immediately after a shock. In addition, optical mapping visualizes the virtual electrodes that are generated during stimulation and defibrillation pulses, which contributed to the formulation of the virtual electrode hypothesis. The generation of virtual electrode induced phase singularities during defibrillation is arrhythmogenic and may lead to the induction of fibrillation subsequent to defibrillation. Defibrillating with low energy may circumvent this problem. Therefore, the current challenge is to use the knowledge provided by optical mapping to develop a low energy approach of defibrillation, which may lead to more successful defibrillation

Interventional and surgical occlusion of the left atrial appendage

With a steadily increasing prevalence, atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide and an independent risk factor for stroke caused by thromboembolic events. The left atrial appendage (LAA) is the primary source of thromboemboli in patients with nonvalvular AF who have a stroke. Novel strategies (such as mechanical and nonpharmacological intervention) targeting the LAA in patients with AF for stroke prevention have become a major focus during the past decade. Some devices for percutaneous LAA occlusion are supported by robust clinical data obtained from randomized trials or large registries, and are a valid alternative to pharmacological stroke prevention. However, the incidence of periprocedural complications and the presence of device-related thrombi or residual LAA leaks, whose long-term clinical implications are still unknown, are limiting factors in wider acceptability of these techniques. In this Review, we discuss the available techniques for LAA occlusion in patients with nonvalvular AF at high risk of stroke. We describe the pharmacological and mechanical approaches to LAA occlusion, and provide the current clinical evidence for various strategies. We particularly focus on the current management of the LAA, and discuss the challenges and future implications of the available approaches to LAA occlusion