5,478 research outputs found

    Lively children trapped in an island of disadvantage: Verbal play of Cantonese working-class schoolboys in Hong Kong

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    In this paper I describe the mocking and playful verbal practices of some Cantonese working-class secondary schoolboys in an English language lesson in Hong Kong. I show how these Cantonese-speaking adolescents seek to assert their indigenous identity and their ingenious Cantonese competence in an educational system that places Cantonese at the bottom of the hierarchy of languages. These self-asserting verbal practices of working- class schoolboys, while in themselves artful and playful, do not contribute to the breaking through of the reproduction and perpetuation of these schoolboys' subordinated and insulated Cantonese sociocultural world, where there is little access to the socioeconomically dominant symbolic resource of English. Without access to English, they can hardly access the middle-class bilingual identity and the socioeconomic success and social status that come with it. Paradoxically, by acting out resistance to an alienating English curriculum, they contribute to the perpetuation of their own insularity and subordination and are trapped in a cycle of disadvantage. The paper concludes with a discussion of the possible impact of the transition of Hong Kong from a British colony to a Special Administrative Region (SAR) of China on language, identity, and social class in post-1997 Hong Kong. © Walter de Gruyter.postprin

    Improving self-organising information maps as navigational tools: A semantic approach

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    Purpose - The goal of the research is to explore whether the use of higher-level semantic features can help us to build better self-organising map (SOM) representation as measured from a human-centred perspective. The authors also explore an automatic evaluation method that utilises human expert knowledge encapsulated in the structure of traditional textbooks to determine map representation quality. Design/methodology/approach - Two types of document representations involving semantic features have been explored - i.e. using only one individual semantic feature, and mixing a semantic feature with keywords. Experiments were conducted to investigate the impact of semantic representation quality on the map. The experiments were performed on data collections from a single book corpus and a multiple book corpus. Findings - Combining keywords with certain semantic features achieves significant improvement of representation quality over the keywords-only approach in a relatively homogeneous single book corpus. Changing the ratios in combining different features also affects the performance. While semantic mixtures can work well in a single book corpus, they lose their advantages over keywords in the multiple book corpus. This raises a concern about whether the semantic representations in the multiple book corpus are homogeneous and coherent enough for applying semantic features. The terminology issue among textbooks affects the ability of the SOM to generate a high quality map for heterogeneous collections. Originality/value - The authors explored the use of higher-level document representation features for the development of better quality SOM. In addition the authors have piloted a specific method for evaluating the SOM quality based on the organisation of information content in the map. © 2011 Emerald Group Publishing Limited

    Towards open corpus adaptive hypermedia: A study of novelty detection approaches

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    Classic adaptive hypermedia systems are able to track a user's knowledge of the subject and use it to evaluate the novelty and difficulty of content encountered by the user. Our goal is to implement this functionality in an open corpus context where a domain model is not available nor is the content indexed with domain concepts. We examine methods for novelty measurement based on automatic text analysis. To compare these methods, we use an evaluation approach based on knowledge encapsulated in the structure of a textbook. Our study shows that a knowledge accumulation method adopted from the domain of intelligent tutoring systems offers a more meaningful novelty measurement than methods adapted from the area of personalized information retrieval. © 2011 Springer-Verlag

    Evaluating tag-based information access in image collections

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    The availability of social tags has greatly enhanced access to information. Tag clouds have emerged as a new "social" way to find and visualize information, providing both one-click access to information and a snapshot of the "aboutness" of a tagged collection. A range of research projects explored and compared different tag artifacts for information access ranging from regular tag clouds to tag hierarchies. At the same time, there is a lack of user studies that compare the effectiveness of different types of tag-based browsing interfaces from the users point of view. This paper contributes to the research on tag-based information access by presenting a controlled user study that compared three types of tag-based interfaces on two recognized types of search tasks - lookup and exploratory search. Our results demonstrate that tag-based browsing interfaces significantly outperform traditional search interfaces in both performance and user satisfaction. At the same time, the differences between the two types of tag-based browsing interfaces explored in our study are not as clear. Copyright 2012 ACM

    Influence of interleukin-2 on Ca2+ handling in rat ventricular myocytes

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    In the present study, we examined the effect of interleukin-2 (IL-2) on cardiomyocyte Ca2+ handling. The effects of steady-state and transient changes in stimulation frequency on the intracellular Ca2+ transient were investigated in isolated ventricular myocytes by spectrofluorometry. In the steady state (0.2 Hz) IL-2 (200 U/ml) decreased the amplitude of Ca2+ transients induced by electrical stimulation and caffeine. At 1.25 mM extracellular Ca2+ concentration ([Ca 2+]o), when the stimulation frequency increased from 0.2 to 1.0 Hz, diastolic Ca2+ level and peak intracellular Ca 2+ concentration ([Ca2+]i), as well as the amplitude of the transient, increased. The positive frequency relationships of the peak and amplitude of [Ca2+]i transients were blunted in the IL-2-treated myocytes. The effect of IL-2 on the electrically induced [Ca2+]i transient was not normalized by increasing [Ca2+]o to 2.5 mM. IL-2 inhibited the frequency relationship of caffeine-induced Ca2+ release. Blockade of sarcoplasmic reticulum (SR) Ca2+-ATPase with thapsigargin resulted in a significant reduction of the amplitude-frequency relationship of the transient similar to that induced by IL-2. The restitutions were not different between control and IL-2 groups at 1.25 mM [Ca2+]o, which was slowed in IL-2-treated myocytes when [Ca2+]o was increased to 2.5 mM. There was no difference in the recirculation fraction (RF) between control and IL-2-treated myocytes at both 1.25 and 2.5 mM [Ca 2+]o. The effects of IL-2 on frequency relationship, restitution, and RF may be due to depressed SR functions and an increased Na+-Ca2+ exchange activity, but not to any change in L-type Ca2+ channels. © 2003 Elsevier Ltd. All rights reserved.postprin

    Inferring Influenza Infection Attack Rate from Seroprevalence Data

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    Genome maps across 26 human populations reveal population-specific patterns of structural variation.

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    Large structural variants (SVs) in the human genome are difficult to detect and study by conventional sequencing technologies. With long-range genome analysis platforms, such as optical mapping, one can identify large SVs (>2 kb) across the genome in one experiment. Analyzing optical genome maps of 154 individuals from the 26 populations sequenced in the 1000 Genomes Project, we find that phylogenetic population patterns of large SVs are similar to those of single nucleotide variations in 86% of the human genome, while ~2% of the genome has high structural complexity. We are able to characterize SVs in many intractable regions of the genome, including segmental duplications and subtelomeric, pericentromeric, and acrocentric areas. In addition, we discover ~60 Mb of non-redundant genome content missing in the reference genome sequence assembly. Our results highlight the need for a comprehensive set of alternate haplotypes from different populations to represent SV patterns in the genome
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