Numerical modelling of single-layer folding: clarification of an issue regarding the possible effect of computer codes and the influence of initial irregularities

The influence of initial perturbation geometry and material propel-ties on final fold geometry has been investigated using finite-difference (FLAC) and finite-element (MARC) numerical models. Previous studies using these two different codes reported very different folding behaviour although the material properties, boundary conditions and initial perturbation geometries were similar. The current results establish that the discrepancy was not due to the different computer codes but due to the different strain rates employed in the two previous studies (i.e. 10(-6) s(-1) in the FLAC models and 10(-14) s(-1) in the MARC models). As a result, different parts of the elasto-viscous rheological field were bring investigated. For the same material properties, strain rate and boundary conditions, the present results using the two different codes are consistent. A transition in Folding behaviour, from a situation where the geometry of initial perturbation determines final fold shape to a situation where material properties control the final geometry, is produced using both models. This transition takes place with increasing strain rate, decreasing elastic moduli or increasing viscosity (reflecting in each case the increasing influence of the elastic component in the Maxwell elastoviscous rheology). The transition described here is mechanically feasible but is associated with very high stresses in the competent layer (on the order of GPa), which is improbable under natural conditions. (C) 2000 Elsevier Science Ltd. All rights reserved.

A sociocultural analysis of language learning: New forms of literacy practices in a language and culture awareness programme

This paper reports on a sociocultural study conducted in a Catholic primary school in the Australian outback and provides insights into how policy related to Languages Other Than English (LOTE) programmes is implemented in a specific location and interwoven within the literacy practices of children, parents and teachers. A case study that tracked a Year Four student's learning and development during a Language and Culture Awareness Programme is discussed within a discourse of cultural and linguistic practices. Significant aspects of the student's learning related to a phenomenon called multi-tiered scaffolding temporarily disrupted the established literacy practices in the school community. Implications of the research for second-language teaching and learning in Australian primary schools are elaborated.

Speaking for others: The pros and cons of group advocates using collective language

We examined how rhetorical style affects evaluations of group advocates, and how these evaluations are moderated by group identification. University students were given a letter to the editor defending student welfare. The argument was either constructed using personal language ('I believe') or collective language ('we believe'). Furthermore, the letter was either attributed to an official advocate (president of the student union) or an unofficial advocate (a rank-and-file member of the student body). Consistent with the social identity perspective, participants who showed strong identification as a university student thought that the group would feel better represented by official advocates using collective rather than personal language. Low identifiers, however, did not rate the rhetorical styles differently on representativeness. Furthermore, low identifiers (but not high identifiers) rated official advocates as more likable and more effective when they used personal rather than collective language. The discussion focuses on the conflict low identifiers might feel between (a) needing to homogenize with other group members in order to maximize the influence and political effectiveness of their message at the collective level, and (b) protecting themselves against categorization threat.

Spelling in adults: The combined influences of language skills and reading experience

One hundred and twelve university students completed 7 tests assessing word-reading accuracy, print exposure, phonological sensitivity, phonological coding and knowledge of English morphology as predictors of spelling accuracy. Together the tests accounted for 71% of the variance in spelling, with phonological skills and morphological knowledge emerging as strong predictors of spelling accuracy for words with both regular and irregular sound-spelling correspondences. The pattern of relationships was consistent with a model in which, as a function of the learning opportunities that are provided by reading experience, phonological skills promote the learning of individual word orthographies and structural relationships among words.