Discourse in Action: Introducing Mediated Discourse Analysis

From emails relating to adoption over the Internet to discussions in the airline cockpit, the spoken or written texts we produce can have significant social consequences. The area of Mediated Discourse Analysis considers texts in their social and cultural contexts to explore the actions individuals take with texts - and the consequences of those actions. Discourse in Action: brings together leading scholars from around the world in the area of Mediated Discourse Analysis reveals ways in which its theory and methodology can be used in research into contemporary social situations explores real situations and draws on real data in each chapter shows how analysis of texts in their social contexts broadens our understanding of the real world. Taken together, the chapters provide a comprehensive overview to the field and present a range of current studies that address some of the most important questions facing students and researchers in linguistics, education, communication studies and other fields.

Creativity and discourse

This paper will consider the relationship between discourse analysis and creativity and elucidate the ways in which a discourse analytical approach to creativity might be distinguished from the ‘language and creativity’ approaches which currently dominate applied linguistics and sociolinguistics. In the ‘discourse and creativity’ approach I will be describing, creativity is located not in language per se, but in the strategic ways people use language in concrete situations in order to stimulate social change. I will explore how aspects of this approach are reflected in work carried out within the paradigm of world Englishes.

Voice, appropriation and discourse representation in a student writing task

We investigate the practices by which bilingual university students in Hong Kong appropriate texts in producing utterances, particularly written texts. Following Wertsch and his colleagues we ask: • To what extent do our students appropriate texts in constructing their own discourses? • What linguistic means do they use to do this? • What can these processes tell us about what they now can do with discourse representation; and • What do we need to teach them? This research shows that our students' writing displays considerable intertextuality and interdiscursivity. Responses to this writing in tutorial sessions indicate that they are skilled at orchestrating the multiple voices within their own discourses. The commonly stated concern that our students do not know how to do quotation and citation correctly is somewhat misplaced and researchers need to move the focus away from the mechanisms of citation and attribution to the social practices of textual appropriation.

Talking AIDS in Hong Kong: Cultural models in public health discourse

This paper explores issues of cultural models in the discourse of public health in a multicultural, multilingual context through a 'frame analysis' of 20 AIDS awareness campaigns aired in both English and Cantonese in Hong Kong from 1987 to 1994. Using a methodology derived from the work of Goffman (1974), and Gee (1990), it examines how the authors of AIDS awareness messages in Hong Kong project cultural models on several different levels of "framing" and how these models both reflect and validate dominant ideologies within the society.

Suicide candy: tracing the discourse itineraries of food risk

Traditional approaches to the way people react to food risks often focus on ways in which the media distort information about risk, or on the deficiencies in people’s interpretation of this information. In this chapter Jones offers an alternative model which sees decisions regarding food risk as taking place at a complex nexus where different people, texts, objects and practices, each with their own histories, come together. Based on a case study of a food scandal involving a particular brand of Chinese candy, Jones argues that understanding why people respond the way they do to food risk requires tracing the itineraries along which different people, texts, objects and practices have traveled to converge at particular moments, and understanding the kinds of concrete social actions that these convergences make possible.

Doing well by talking good? A topic modelling-assisted discourse study of corporate social responsibility

Using the novel technique of topic modelling, this paper examines thematic patterns and their changes over time in a large corpus of corporate social responsibility (CSR) reports produced in the oil sector. Whereas previous research on corporate communications has been small-scale or interested in selected lexical aspects and thematic categories identified ex ante, our approach allows for thematic patterns to emerge from the data. The analysis reveals a number of major trends and topic shifts pointing to changing practices of CSR. Nowadays ‘people’, ‘communities’ and ‘rights’ seem to be given more prominence, whereas ‘environmental protection’ appears to be less relevant. Using more established corpus-based methods, we subsequently explore two top phrases - ‘human rights’ and ‘climate change’ that were identified as representative of the shifting thematic patterns. Our approach strikes a balance between the purely quantitative and qualitative methodologies and offers applied linguists new ways of exploring discourse in large collections of texts.

Taxonomic Identity in Microbial Eukaryotes: A Practical Approach Using the Testate Amoeba Centropyxis to Resolve Conflicts Between Old and New Taxonomic Descriptions

The present work focuses on 12 taxa of the genus Centropyxis Stein, 1857 to explore the conflict between traditional and contemporary taxonomic practices. We examined the morphology, biometry, and ecology of 2,120 Centropyxis individuals collected from Tiete River, Sao Paulo, Brazil; with these new data we studied the consistency of previously described species, varieties, and forms. We encountered transitional forms of test morphology that undermine specific and varietal distinctions for three species and nine varieties. Biometrical analyses made comparing the organisms at the species level suggest a lack of separation between Centropyxis aculeata and Centropyxis discoides, and a possible distinction for Centropyxis ecornis based on spine characteristics. However, incongruence between recent and previous surveys makes taking any taxonomic-nomenclatural actions inadvisable, as they would only add to the confusion. We suggest an explicit and objective taxonomic practice in order to enhance our taxonomic and species concepts for microbial eukaryotes. This will allow more precise inferences of taxon identity for studies in other areas.

On the influence of imputation in classification: practical issues

The substitution of missing values, also called imputation, is an important data preparation task for many domains. Ideally, the substitution of missing values should not insert biases into the dataset. This aspect has been usually assessed by some measures of the prediction capability of imputation methods. Such measures assume the simulation of missing entries for some attributes whose values are actually known. These artificially missing values are imputed and then compared with the original values. Although this evaluation is useful, it does not allow the influence of imputed values in the ultimate modelling task (e.g. in classification) to be inferred. We argue that imputation cannot be properly evaluated apart from the modelling task. Thus, alternative approaches are needed. This article elaborates on the influence of imputed values in classification. In particular, a practical procedure for estimating the inserted bias is described. As an additional contribution, we have used such a procedure to empirically illustrate the performance of three imputation methods (majority, naive Bayes and Bayesian networks) in three datasets. Three classifiers (decision tree, naive Bayes and nearest neighbours) have been used as modelling tools in our experiments. The achieved results illustrate a variety of situations that can take place in the data preparation practice.

Quality indices for (practical) clustering evaluation

Clustering quality or validation indices allow the evaluation of the quality of clustering in order to support the selection of a specific partition or clustering structure in its natural unsupervised environment, where the real solution is unknown or not available. In this paper, we investigate the use of quality indices mostly based on the concepts of clusters` compactness and separation, for the evaluation of clustering results (partitions in particular). This work intends to offer a general perspective regarding the appropriate use of quality indices for the purpose of clustering evaluation. After presenting some commonly used indices, as well as indices recently proposed in the literature, key issues regarding the practical use of quality indices are addressed. A general methodological approach is presented which considers the identification of appropriate indices thresholds. This general approach is compared with the simple use of quality indices for evaluating a clustering solution.

A note on a practical relationship between filter coefficients and scaling and wavelet functions of Discrete Wavelet Transforms

In this paper, the relationship between the filter coefficients and the scaling and wavelet functions of the Discrete Wavelet Transform is presented and exemplified from a practical point-of-view. The explanations complement the wavelet theory, that is well documented in the literature, being important for researchers who work with this tool for time-frequency analysis. (c) 2011 Elsevier Ltd. All rights reserved.

Practical synthesis of chiral beta-telluro amines by ring-opening reaction of aziridines

A set of chiral beta-tellurium amines and their selenium and sulfur-containing derivatives have been efficiently synthesized in good to excellent yields via the ring-opening reaction of chiral aziridines by chalcogen nucleophilic species. (C) 2008 Elsevier B.V. All rights reserved.

Grafisk profilering med praktisk tillämpning på PZ hair : Graphic profiling with a practical application on PZ hair

Design, Grafiskt program, Symbol, Hair