Synthetic use of the primary kinetic isotope effect in hydrogen atom transfer: generation of α-aminoalkyl radicals.

addresses: School of Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, UKEX4 4QD. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2010 Royal Society of ChemistryThe extent to which deuterium can act as a protecting group to prevent unwanted 1,5-hydrogen atom transfer to aryl and vinyl radical intermediates was examined in the context of the generation of α-aminoalkyl radicals in a pyrrolidine ring. Intra- and intermolecular radical trapping following hydrogen atom transfer provides an illustration of the use of the primary kinetic isotope effect in directing the outcome of synthetic C-C bond-forming processes

Collaborative strategic reading on multi-touch and multi-user digital tabletop displays

This paper is part of a work-in-progress that reports on the design, development, and evaluation of a Digital Collaborative Strategic Reading (DCSR) application with regard to its effectiveness in improving English as a second language (ESL) reading comprehension. The DCSR application allows users to read collaboratively on multi-touch and multi-user digital tabletop displays that support both face-to-face and computer-based interaction. The application is designed to provide systematic instruction on tabletop computers using four main comprehension strategies that form the Collaborative Strategic Reading (CSR) instructional approach. The paper addresses one main research question: ‘How does the use of the tabletop-based reading application (DCSR) affect learners’ reading processes and outcomes?”, and the following sub-questions: (1) What is the impact of the tabletop-based reading system on learners’ reading scores with regard to the reading assessments? (2) How do learners collaboratively construct meaning on the tabletop? To answer these research questions, the subjects used the DCSR application on tabletop computers in groups of four, once a week for 5 weeks. Data were collected and analysed using both qualitative and quantitative methods. Each reading session was preceded by a cloze test and followed by two types of assessment: a written recall test and a cloze test; both tests were designed to reflect the students' comprehension of the reading passages. The paper will report on the design of the software and the administration of the study, but will focus on the analysis of the data from the different sources, and present insights into the nature of collaborative reading using the DCSR application on a tabletop computer

Adversarial Detection by Approximation of Ensemble Boundary

A new method of detecting adversarial attacks is proposed for an ensemble of Deep Neural Networks (DNNs) solving two-class pattern recognition problems. The ensemble is combined using Walsh coefficients which are capable of approximating Boolean functions and thereby controlling the complexity of the ensemble decision boundary. The hypothesis in this paper is that decision boundaries with high curvature allow adversarial perturbations to be found, but change the curvature of the decision boundary, which is then approximated in a different way by Walsh coefficients compared to the clean images. By observing the difference in Walsh coefficient approximation between clean and adversarial images, it is shown experimentally that transferability of attack may be used for detection. Furthermore, approximating the decision boundary may aid in understanding the learning and transferability properties of DNNs. While the experiments here use images, the proposed approach of modelling two-class ensemble decision boundaries could in principle be applied to any application area. Code for approximating Boolean functions using Walsh coefficients: https://doi.org/10.24433/CO.3695905.v1Comment: 17 pages, 5 figures, 5 table

Investigations into the effectiveness of deuterium as a "protecting group" for C-H bonds in radical reactions involving hydrogen atom transfer.

addresses: School of Biosciences (originally Department of Chemistry), University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK. [email protected]: Journal Article; Research Support, Non-U.S. Gov'tCopyright © 2008 Royal Society of ChemistryCompetition experiments have been carried out to determine the extent to which deuterium can be used as a protecting group for carbon-hydrogen bonds in radical-based intramolecular hydrogen atom transfer processes

Fluency issues in L2 academic presentations: Linguistic, cognitive and psychological influences on pausing behaviour

Fluency is usually defined in relation to temporal features such as speed of delivery and pauses, and such features are generally the focus of research on fluency. The reasons why pauses occur, however, have received much less attention. This study first explores the distribution and location of pauses in short academic presentations given by students as part of an English for academic purposes (EAP) course at an Australian university. This data is then used to investigate the reasons for a sample of those pauses, using the researchers’ interpretations, followed by student explanations in stimulated recall interviews (SRIs). The main findings provide confirmation that the location and the reasons for those pauses which are likely to affect the fluency of the presentations are a result not only of linguistic and cognitive issues, but also of psychological factors. The results underline the importance of taking all of these factors into account in EAP programmes by encouraging student awareness of their pausing behaviour, its causes, the effect on their audience, and of strategies for dealing with psycholinguistic, as well as linguistic and cognitive issues. The results confirm the value of SRI as a technique in exploring assumptions about the reasons for pauses, and the limitation of focusing solely on statistical analyses of pausing phenomena

XXIInd International CALL Research Conference

Language and culture, while closely related and best acquired together (Brooks, 1968), are often presented in textbooks in an oversimplified form, focusing on a few salient principles (Stockwell, 2018). However, in multicultural contexts, for migrants and refugees in particular to develop the language and cultural understanding they need, a more sophisticated approach is required. The focus of this study is a set of reusable resources in the form of an online open book for use in English for Academic Purpose (EAP) programmes. A collaborative approach is adopted through the use of authentic, interactive resources by using available technology to encourage active participation and the co-creation of materials. The wider use of Open Educational Resources (OERs) is indicative of the shift from traditional learning resources to more user-generated content fostering deeper individual engagement and personalized learning. By leveraging technological tools, this approach not only enhances accessibility and adaptability but also reflects the broader trend in Computer-Assisted Language Learning (CALL) towards more interactive and student-centred learning environments. The materials are evaluated using a three-stage approach: 1) critical comments from experts working through the materials. Appropriate improvements are then carried out and 2) group feedback is obtained from small groups of users representative of the target audience. Any necessary further changes are made and 3) larger scale use and evaluation of the materials is carried out. This systematic evaluation ensures that the resources are continuously refined to meet the evolving needs of learners, thereby supporting the ongoing transition in CALL towards more open, flexible, and collaborative educational practices

European Association for Computer-Assisted Language Learning 2023 (EuroCALL 2023)

This study examines the potential of VoiceThread (VT) as a learning tool to enhance learners’ performance and confidence while facilitating ongoing independent practice in a 10-week English for Academic Purposes (EAP) programme in an Australian university. Students carried out weekly academic presentations on topics of personal interest using VT for recording and rehearsal. Their recordings were shared for peer review and teacher feedback. The recordings were analysed in relation to a number of features to measure utterance fluency, including speed, repairs and pauses. Questionnaires were used to investigate students’ perceptions of the value of the task, of their performance on the task, and of changes in their performance and confidence over time. Interviews were conducted to investigate the potential of recording and rehearsal for long-term independent practice. In total, 34 students participated in 10-week courses, 22 students using the VT software, and 12 students in a comparison class following the same curriculum, but without the VT software. The findings suggest that regular VT tasks, over time, help students develop their spoken English performance and confidence. Such voice-recording activities hold promise for improving oral performance by encouraging independent practice in oral activities, effectively addressing the time limitations, constraints practice opportunities, and feedback challenges inherent in classroom-based courses

Catalyst: A Programme for Change within British Airways

It is perhaps a truism to state in today\u27s information age that an organization\u27s ability to exploit IT is dependent on the extent to which its managers understand how to apply IT to business advantage. But the biggest challenges are often simple to state and this is one of them. The question is ‘how’ do you get managers to understand? And how do you know when they understand well enough? These were questions within British Airways which needed to be answered in order to develop an IT education programme for senior management in 1987