Fault tolerance of cooperative interception using multiple flight vehicles

Cooperative interception of a moving target by multiple vehicles is studied. The main contributions of research work presented in this paper include: (1) cooperative interception is achieved for multiple vehicles to reach the target simultaneously at a finite time, by proposing and solving for a novel finite-time consensus problem and (2) in addition, the cooperative interception is investigated with tolerance of actuator or network failures, where novel fault tolerant consensus protocols are proposed to address actuator failures (or loss of effectiveness) and network failures, respectively. The maximum fault tolerance against network failures can be estimated. Simulations of a three-against-one interception case are presented to demonstrate the effectiveness of the proposed design approaches.     

Highly selective biomechanical separation of cancer cells from leukocytes using microfluidic ratchets and hydrodynamic concentrator

The separation of cells based on their biomechanical properties, such as size and deformability, is important in applications such as the identification of circulating tumor cells, where morphological differences can be used to distinguish target cancer cells from contaminant leukocytes. Existing filtration-based separation processes are limited in their selectivity and their ability to extract the separated cells because of clogging in the filter microstructures. We present a cell separation device consisting of a hydrodynamic concentrator and a microfluidic ratchet mechanism operating in tandem. The hydrodynamic concentrator removes the majority of the fluid and a fraction of leukocytes based on size, while the microfluidic ratchet mechanism separates cancer cells from leukocytes based on a combination of size and deformability. The irreversible ratcheting process enables highly selective separation and robust extraction of separated cells. Using cancer cells spiked into leukocyte suspensions, the complete system demonstrated a yield of 97%, while enriching the concentration of target cancer cells 3000 fold relative to the concentration of leukocytes.     

Fair Pairs and Three Part Praise – developing the sustained use of differential reinforcement of alternative behaviour

A training course of two after-school sessions was run for teaching assistants (TAs) in a UK inner city primary school. The subject of the training was classroom use of a version of differential reinforcement of alternative behaviours (DRAs) known as Fair Pairs. The training introduced the concept of “Three Part Praise” within Fair Pairs. The method of introduction involved training sessions, with the TAs explaining the process to their class teacher colleagues following each session. The TAs and class teachers were then asked to try the methodology in their classrooms. A follow-up session was held after six months for the TAs to feedback on their experiences. Results showed that most of the TA/class teacher “teams” were still using the approach after six months. Of those who responded most reported improvement in behaviour in the class. The implications of the methodology for training and the effectiveness of the approach being taught are discussed with suggestions for future research.     

Language learning and antiracism: some pedagogical challenges

It is often argued that the study of a foreign language can influence the attitudes and behaviour of learners. One of the goals of language teaching is to challenge stereotypes and encourage learners to engage with the cultural forms that can be accessed through a new language. Through learning a language it is hoped that learners will draw on their experiences to reflect critically on their own cultures and identities. We set out to examine these claims with respect to an advanced Open University French course for adult speakers of English. This article reports on a documentary analysis of the course materials for a particular unit and of a very small opportunity sample of student work and tutor comments. The unit sets out to provide a positive view of France as a multicultural society. The analysis focuses on the extent to which the materials and the tasks help learners engage with issues of racism, xenophobia, antiracism and human rights. We found that issues of race and racism are not presented in their complexity and that the materials and learning tasks unwittingly tend to reinforce stereotyped views. We suggest that attention should be given to helping students develop skills of intercultural evaluation. This requires an understanding of human rights on the one hand and of the various forms and manifestations of racism and xenophobia on the other. We conclude by proposing some guidelines for course writers and teachers that invite them to include a range of perspectives, including those of minorities. This attention to materials and pedagogy should enable students to engage critically with issues of race, identity and culture as they learn a foreign language.     

Wanted: A speech salesman for the United States government

This essay argues that the alleged demise of a unified and coherent public in contemporary twentieth‐century American political discourse is more a symptom of how we have visually objectified “the people” than it is a newly discovered fragmentation of the “thing” itself. This claim is developed by examining the emergence of social documentary photojournalism in the 1930s and its ideological implications for American liberal‐democratic rhetorical practices. James Agee and Walker Evans's Let Us Now Praise Famous Men is treated as a representative anecdote that illustrates the problems and possibilities of the tensions between individualism and collectivism that rest at the heart of liberal democracy.     

Cognitive neuroscience and education: unravelling the confusion

This paper critically examines the application of research into cognitive neuroscience to educational contexts. It first considers recent warnings from within the neuroscientific community itself about the limitations of current neuroscientific knowledge and the urgent need to dispel popular ‘neuromyths’ which have become accepted in many classrooms. It also criticises the use of over‐simplified neuroscience to add scientific credibility to curricular reform, as has been the case in the rationale behind the recent implementation of the Northern Ireland Revised Curriculum. The paper then draws on the philosophy of Wittgenstein to highlight a further conceptual confusion which often surrounds the application of neuroscience to education.