Advancing video research methodology to capture the processes of social interaction and multimodality

In this reflective methodological paper we focus on affordances and challenges of video data. We compare and analyze two research settings that use the latest video technology to capture classroom interactions in mathematics education, namely, The Social Unit of Learning (SUL) project of the University of Melbourne and the MathTrack project of the University of Helsinki. While using these two settings as examples, we have structured our reflections around themes pertinent to video research in general, namely, research methods, data management, and research ethics. SUL and MathTrack share an understanding of mathematics learning as social multimodal practice, and provide possibilities for zooming into the situational micro interactions that construct collaborative problem-solving learning. Both settings provide rich data for in-depth analyses of peer interactions and learning processes. The settings share special needs for technical support and data management, as well as attention to ethical aspects from the perspective of the participants' security and discretion. SUL data are especially suitable for investigating interactions on a broad scope, addressing how multiple interactional processes intertwine. MathTrack, on the other hand, enables exploration of participants' visual attention in detail and its role in learning. Both settings could provide tools for teachers' professional development by showing them aspects of classroom interactions that would otherwise remain hidden.Peer reviewe

Phases of collaborative mathematical problem solving and joint attention : a case study utilizing mobile gaze tracking

Given the recent development of mobile gaze-tracking devices it has become possible to view and interpret what the student sees and unravel the associated problem-solving processes further. It has also become possible to pinpoint joint attention occurrences that are fundamental for learning. In this study, we examined joint attention in collaborative mathematical problem solving. We studied the thought processes of four 15-16-year-old students in their regular classroom, using mobile gaze tracking, video and audio recordings, and smartpens. The four students worked as a group to find the shortest path to connect the vertices of a square. Combining information on the student gaze targets with a qualitative interpretation of the context, we identified the occurrences of joint attention, out of which 49 were joint visual attention occurrences and 28 were attention to different representations of the same mathematical idea. We call this joint representational attention. We discovered that 'verifying' (43%) and 'watching and listening' (35%) were the most common phases during joint attention. The most frequently occurring problem solving phases right after joint attention were also 'verifying' (47%) and 'watching and listening' (34%). We detected phase cycles commonly found in individual problem-solving processes ('planning and exploring', 'implementing', and 'verifying') outside of joint attention. We also detected phase shifts between 'verifying', 'watching and listening', and 'understanding' a problem, often occurring during joint attention. Therefore, these phases can be seen as a signal of successful interaction and the promotion of collaboration.Peer reviewe

Effects of xylitol on xylitol-sensitive versus xylitol-resistant streptococcus mutans strains in a three-species in vitro biofilm

We studied the effects of xylitol on biofilms containing xylitol-resistant (Xr) and xylitol-sensitive (Xs) Streptococcus mutans, Actinomyces naeslundii and S. sanguinis. The biofilms were grown for 8 and 24 h on hydroxyapatite discs. The viable microorganisms were determined by plate culturing techniques and fluorescence in situ hybridization (FISH) was performed using a S. mutans-specific probe. Extracellular cell-bound polysaccharides (EPS) were determined by spectrofluorometry from single-species S. mutans biofilms. In the presence of 5 % xylitol, the counts of the Xs S. mutans decreased tenfold in the young (8 h) biofilm (p\0.05) but no effect was seen in the mature (24 h) biofilm. No decrease was observed for the Xr strains, and FISH confirmed these results. No differences were detected in the EPS production of the Xs S. mutans grown with or without xylitol, nor between Xr and Xs S. mutans strains. Thus, it seems that xylitol did not affect the EPS synthesis of the S. mutans strains. Since the Xr S. mutans strains, not inhibited by xylitol, showed no xylitol-induced decrease in the biofilms, we conclude that growth inhibition could be responsible for the decrease of the counts of the Xs S. mutans strains in the clinically relevant young biofilms. © 2012 Springer Science+Business Media, LLC.The work done at IPLA-CSIC (Spain) was funded by the project AGL2009-09445 (Spanish Ministry of Science and Innovation).Peer Reviewe

SHARPIN regulates collagen architecture and ductal outgrowth in the developing mouse mammary gland.

SHARPIN is a widely expressed multifunctional protein implicated in cancer, inflammation, linear ubiquitination and integrin activity inhibition; however, its contribution to epithelial homeostasis remains poorly understood. Here, we examined the role of SHARPIN in mammary gland development, a process strongly regulated by epithelial-stromal interactions. Mice lacking SHARPIN expression in all cells (Sharpin(cpdm)), and mice with a stromal (S100a4-Cre) deletion of Sharpin, have reduced mammary ductal outgrowth during puberty. In contrast, Sharpin(cpdm) mammary epithelial cells transplanted in vivo into wild-type stroma, fully repopulate the mammary gland fat pad, undergo unperturbed ductal outgrowth and terminal differentiation. Thus, SHARPIN is required in mammary gland stroma during development. Accordingly, stroma adjacent to invading mammary ducts of Sharpin(cpdm) mice displayed reduced collagen arrangement and extracellular matrix (ECM) stiffness. Moreover, Sharpin(cpdm) mammary gland stromal fibroblasts demonstrated defects in collagen fibre assembly, collagen contraction and degradation in vitro Together, these data imply that SHARPIN regulates the normal invasive mammary gland branching morphogenesis in an epithelial cell extrinsic manner by controlling the organisation of the stromal ECM. EMBO J 2017 Jan 17; 36(2):165-182