PROSPECTIVE TEACHERS�� INITIAL CONCEPTIONS ABOUT PUPILS�� DIFFICULTIES IN SCIENCE AND MATHEMATICS: A POTENTIAL RESOURCE IN TEACHER EDUCATION

A crucial issue for prospective teachers (PTs) in their education is to develop pedagogical content knowledge (PCK; i.e. how to make a topic comprehensible to pupils). However, research has shown that PTs may have tacit ideas about teaching that act as filters preventing consideration of unfamiliar and discrepant ideas. These ideas must be elicited and taken into consideration in order to be modified. Therefore, PTs’ explicit conceptions may constitute a valuable resource in teacher education. The aim of this study was to investigate PTs’ ideas about pupils’ difficulties, at a topic-specific level, upon beginning the teacher education programme. The “Lesson Preparation Method” was used in four case studies to elicit the conceptions of 32 PTs regarding pupils’ difficulties in four specific science and mathematics topics: plant growth, gases, equations and heat and temperature. In all four topic groups (n = 5 – 11), there was a variety of initial conceptions about pupils’ difficulties, which were categorised into two to five topic-specific categories. Although, initially, PTs may not have expressed any notions about pupils’ difficulties, conceptions were elicited by using the Lesson Preparation Method. Furthermore, we found that the initial ideas corresponded with earlier research on pupils’ difficulties, which could provide a potential resource when creating a scaffolding context in teacher education programmes where PCK development is stimulated.     

Quick chip assay using locked nucleic acid modified epithelial cell adhesion molecule and nucleolin aptamers for the capture of circulating tumor cells

The role of circulating tumor cells (CTCs) in disease diagnosis, prognosis, monitoring of the therapeutic efficacy, and clinical decision making is immense and has attracted tremendous focus in the last decade. We designed and fabricated simple, flat channel microfluidic devices polydimethylsiloxane (PDMS based) functionalized with locked nucleic acid (LNA) modified aptamers (targeting epithelial cell adhesion molecule (EpCAM) and nucleolin expression) for quick and efficient capture of CTCs and cancer cells. With optimized flow rates (10 μl/min), it was revealed that the aptamer modified devices offered reusability for up to six times while retaining optimal capture efficiency (>90%) and specificity. High capture sensitivity (92%) and specificity (100%) was observed in whole blood samples spiked with Caco-2 cells (10–100 cells/ml). Analysis of blood samples obtained from 25 head and neck cancer patients on the EpCAM LNA aptamer functionalized chip revealed that an average count of 5 ± 3 CTCs/ml of blood were captured from 22/25 samples (88%). EpCAM intracellular domain (EpICD) immunohistochemistry on 9 oral squamous cell carcinomas showed the EpICD positivity in the tumor cells, confirming the EpCAM expression in CTCs from head and neck cancers. These microfluidic devices also maintained viability for in vitro culture and characterization. Use of LNA modified aptamers provided added benefits in terms of cost effectiveness due to increased reusability and sustainability of the devices. Our results present a robust, quick, and efficient CTC capture platform with the use of simple PDMS based devices that are easy to fabricate at low cost and have an immense potential in cancer diagnosis, prognosis, and therapeutic planning.