From multiple perspectives to shared understanding

The aim of this study was to explore how learners operating in a small group reach shared understanding as they work out joint research questions and build a theoretical framework and to identify the resources and tools they used in the process. The learners’ own interpretations of their group activities and learning were also taken into account. The data, consisting of group discussions and the documents produced by the group, were subjected to a qualitative content analysis. The group members employed a variety of resources and tools to exchange their individual perspectives and achieve shared understanding. Summaries of relevant literature laid a foundation for the group’s theoretical discussions. Reflective comparisons between their book knowledge and their personal experiences of online interaction and collaboration were frequent, suggesting that such juxtapositions may have enhanced their learning by intertwining the content to be mastered and the activities entailed by this particular content

Interdisciplinary research: putting the methods under the microscope

BACKGROUND: While the desirability of interdisciplinary inquiry has been widely acknowledged, indeed has become 'the mantra of science policy', the methods of interdisciplinary collaboration are opaque to outsiders and generally remain undescribed. DISCUSSION: Many have analysed interdisciplinarity, especially in relation to the creation of new disciplines and institutions. These analyses are briefly outlined. Still, there currently persists a silence about the methods of interdisciplinary collaboration itself, and the core of this paper proposes a template for such methods. SUMMARY: Breaking this silence – by making the methods of interdisciplinary projects transparent – could further invigorate interdisciplinary research

Designing electronic collaborative learning environments

Electronic collaborative learning environments for learning and working are in vogue. Designers design them according to their own constructivist interpretations of what collaborative learning is and what it should achieve. Educators employ them with different educational approaches and in diverse situations to achieve different ends. Students use them, sometimes very enthusiastically, but often in a perfunctory way. Finally, researchers study them and—as is usually the case when apples and oranges are compared—find no conclusive evidence as to whether or not they work, where they do or do not work, when they do or do not work and, most importantly, why, they do or do not work. This contribution presents an affordance framework for such collaborative learning environments; an interaction design procedure for designing, developing, and implementing them; and an educational affordance approach to the use of tasks in those environments. It also presents the results of three projects dealing with these three issues

Analyzing Problem Solving Using Math in Physics: Epistemological Framing via Warrants

Developing expertise in physics entails learning to use mathematics effectively and efficiently as applied to the context of physical situations. Doing so involves coordinating a variety of concepts and skills including mathematical processing, computation, blending ancillary information with the math, and reading out physical implications from the math and vice versa. From videotaped observations of intermediate level students solving problems in groups, we note that students often "get stuck" using a limited group of skills or reasoning and fail to notice that a different set of tools (which they possess and know how to use effectively) could quickly and easily solve their problem. We refer to a student's perception/judgment of the kind of knowledge that is appropriate to bring to bear in a particular situation as epistemological framing. Although epistemological framing is often unstated (and even unconscious), in group problem solving situations students sometimes get into disagreements about how to progress. During these disagreements, they bring forth explicit reasons or warrants in support of their point of view. For the context of mathematics use in physics problem solving, we present a system for classifying physics students' warrants. This warrant analysis offers tangible evidence of their epistemological framing.Comment: 23 page

Identification of candidate tumour suppressor genes frequently methylated in renal cell carcinoma

Promoter region hyermethylation and transcriptional silencing is a frequent cause of tumour suppressor gene (TSG) inactivation in many types of human cancers. Functional epigenetic studies, in which gene expression is induced by treatment with demethylating agents, may identify novel genes with tumour-specific methylation. We used high-density gene expression microarrays in a functional epigenetic study of 11 renal cell carcinoma (RCC) cell lines. Twenty-eight genes were then selected for analysis of promoter methylation status in cell lines and primary RCC. Eight genes (BNC1, PDLIM4, RPRM, CST6, SFRP1, GREM1, COL14A1 and COL15A1) showed frequent (30% of RCC tested) tumour-specific promoter region methylation. Hypermethylation was associated with transcriptional silencing. Re-expression of BNC1, CST6, RPRM and SFRP1 suppressed the growth of RCC cell lines and RNA interference knock-down of BNC1, SFRP1 and COL14A1 increased the growth of RCC cell lines. Methylation of BNC1 or COL14A1 was associated with a poorer prognosis independent of tumour size, stage or grade. The identification of these epigenetically inactivated candidate RCC TSGs can provide insights into renal tumourigenesis and a basis for developing novel therapies and biomarkers for prognosis and detection. © 2010 Macmillan Publishers Limited.Published versio

Structural basis for the recognition and cleavage of histone H3 by cathepsin L

Proteolysis of eukaryotic histone tails has emerged as an important factor in the modulation of cell-cycle progression and cellular differentiation. The recruitment of lysosomal cathepsin L to the nucleus where it mediates proteolysis of the mouse histone H3 tail has been described recently. Here, we report the three-dimensional crystal structures of a mature, inactive mutant of human cathepsin L alone and in complex with a peptide derived from histone H3. Canonical substrate–cathepsin L interactions are observed in the complex between the protease and the histone H3 peptide. Systematic analysis of the impact of posttranslational modifications at histone H3 on substrate selectivity suggests cathepsin L to be highly accommodating of all modified peptides. This is the first report of cathepsin L–histone H3 interaction and the first structural description of cathepsin L in complex with a substrate