Video-mediated interviews to reveal multiple voices in peer collaboration for mathematics learning in groups

Peer collaboration in schools can be a locus for negotiation of power and cultural norms. Set in the context of ethnically and linguistically diverse urban schools, this study discusses the possibilities and limitations of utilizing video-mediated interviews to reveal multiple voices. Our research method is based on video-recorded peer-to-peer interactions wherein a small group of students engaged in mathematics tasks, as well as video-mediated interviews with individual students while watching the video of themselves engaging in group work. Using the theoretical framework of ideological and sociohistorical nature of voice and figured worlds, our analysis revealed the ideologies and sociohistorical norms that influenced the ways in which the students collaborate with their peers. Based on our analyses of the video-mediated interviews, we raise awareness of potential conflicts that could affect the generation and development of ideas through collaboration. We also discuss ways to use video-mediated interviews as a methodology to interrogate the norms underlying collaboration among students in school settings.     

Lexical processes in the recognition of Japanese horizontal and vertical compounds

This lexical decision eye-tracking study investigated whether horizontal and vertical readings elicit comparable behavioral patterns and whether reading directions modulate lexical processes. Response times and eye movements were recorded during a lexical decision task with Japanese bimorphemic compound words presented vertically. The data were then analyzed together with those obtained in a horizontal lexical decision experiment of Miwa, Libben, Dijkstra, and Baayen (2014). Linear mixed-effects analyses of response times and eye movements revealed that, although response times and first fixation durations were notably shorter in horizontal reading than vertical reading, the vertical reading elicited fewer fixations. Furthermore, while compounds were recognized largely in comparable ways regardless of reading direction, several lexical processes were found to be reading-direction-dependent. Particularly, processing of the first morpheme was modulated by reading direction in a late time frame, such that a horizontal reading advantage was observed for words with a high frequency first morpheme. All in all, the two reading directions do not only differ quantitatively in processing speed, but also qualitatively in terms of underlying processing mechanisms.     

Characterization of low viscosity polymer solutions for microchip electrophoresis of non-denatured proteins on plastic chips

In this paper, we study characteristics of polymers (methylcellulose, hypromellose ((hydroxypropyl)methyl cellulose), poly(vinylpyrrolidone), and poly(vinyl alcohol)) with different chemical structures for microchip electrophoresis of non-denatured protein samples in a plastic microchip made of poly(methyl methacrylate) (PMMA). Coating efficiency of these polymers for controlling protein adsorption onto the channel surface of the plastic microchip, wettability of the PMMA surface, and electroosmotic flow in the PMMA microchannels in the presence of these polymers were compared. Also relative electrophoretic mobility of protein samples in solutions of these polymers was studied. We showed that when using low polymer concentrations (lower than the polymer entanglement point) where the sieving effect is substantially negligible, the interaction of the samples with the polymer affected the electrophoretic mobility of the samples. This effect can be used for achieving better resolution in microchip electrophoresis of protein samples.