The response of pre-service teachers to a compulsory research project

This paper draws on 159 survey responses of fourth year Education students as they embark on a research project based in their internship school. The project explores predisposition to research and the level of preparedness to undertake a research project. The students who met most frequently with their supervisor and showed higher research self-efficacy were also most likely to want to undertake postgraduate study and reacted positively to good personal support and a feeling of belonging to a research “community”. Many felt they were “unconnected” to a learning community, and specifically to their supervisor. They were generally positive about their ability to do the tasks, such as finding and writing up literature, even though they were concerned about managing the overall commitment. Despite this they were optimistic about completion. Only 5% were sure they would undertake postgraduate study in the future, and 65% were sure they would not do so. In an environment where there is commitment to promoting research skills consistent with the needs of a knowledge society and drawing on evidence to inform practice, the findings not only raise the question of how best to support and give meaning to early research endeavours of preservice teachers, but also highlights the challenge of achieving this against a high level of disinterest in further tertiary study.     

Spatially variant red blood cell crenation in alternating current non-uniform fields

Alternating-current (AC) electrokinetics involve the movement and behaviors of particles or cells. Many applications, including dielectrophoretic manipulations, are dependent upon charge interactions between the cell or particle and the surrounding medium. Medium concentrations are traditionally treated as spatially uniform in both theoretical models and experiments. Human red blood cells (RBCs) are observed to crenate, or shrink due to changing osmotic pressure, over 10 min experiments in non-uniform AC electric fields. Cell crenation magnitude is examined as functions of frequency from 250 kHz to 1 MHz and potential from 10 V_pp to 17.5 V_pp over a 100 μm perpendicular electrode gap. Experimental results show higher peak to peak potential and lower frequency lead to greater cell volume crenation up to a maximum volume loss of 20%. A series of experiments are conducted to elucidate the physical mechanisms behind the red blood cell crenation. Non-uniform and uniform electrode systems as well as high and low ion concentration experiments are compared and illustrate that AC electroporation, system temperature, rapid temperature changes, medium pH, electrode reactions, and convection do not account for the crenation behaviors observed. AC electroosmotic was found to be negligible at these conditions and AC electrothermal fluid flows were found to reduce RBC crenation behaviors. These cell deformations were attributed to medium hypertonicity induced by ion concentration gradients in the spatially nonuniform AC electric fields.     

Graphic organizers or graphic overviews? Presentation order effects with computer-based text

It has long been assumed that graphic organizers (GOs) should be presented to students following text as an organizer, rather than preceding text as an overview. Robinson et al. (Educational Technology Research & Development, 51(4), 25?C41, 2003) challenged this assumption by finding support for GOs as an overview. The present study further examined this issue by having 111 undergraduates view three GOs before (overview) or after (organizer) reading or listening to a narration of a 3,400-word text, followed by measures of retention and transfer. Students who received GOs as organizers transferred knowledge better than those who received GOs as overviews. Whether GOs should also be used as overviews, as prescribed by Robinson et al., is unclear and in need of further investigation.