Classifying Higher Rank Toeplitz Operators.

To a higher rank directed graph (Λ, d), in the sense of Kumjian and Pask, 2000, one can associate natural noncommutative analytic Toeplitz algebras, both weakly closed and norm closed. We introduce methods for the classification of these algebras in the case of single vertex graphs

Dignity in and at work : why it matters

Throughout the history of social science, dignity is a word that is continually used to express concern about various aspects of work. Within these concerns we see a set of implicit understandings of what dignity is, and what it does, and profoundly, dignity as an essential need of the human spirit. Beginning with some of the earliest insights that inform contemporary analyses of work we can see that, in different ways and relating their concerns to different eras, writers on work and organisation each conceptualise increasing industrialisation as entailing a possible denial of dignity. Most recently the dignity at work debate been colonised by the focus on bullying and harassment. The high profile campaign for 'dignity at work' (cf: Amicus and The Andrea Adams Trust) draws attention to the everyday bullying behaviours that occur in the workplace serving to intimidate and oppress employees, coming both from the workplace hierarchy, and, whether through cultural consensus or individual malintent, from peers. This reflects a feeling that some fundamental rights are coming under pressure. The proposed UK 'dignity at work act' advises that 'every employee shall have the right to dignity at work'

What good are markets in punishment?

There are two chronically unexamined assumptions about privatisation in punishment. First is the idea that it is a relatively new development. In fact, penal activity has always been (at least partly) private. Second, it is assumed that the state can create a market when and where it wants. This article aims to unpack such intuitions in order to expose neglected aspects of privatisation in punishment. I argue that the experiment with the kinds of privatisation that sceptics worry most about, private companies owning and running whole prisons, has amounted to a ripple rather than a tidal wave in the sea of penal activity. Attempts to increase the private sector's role have largely failed to produce efficient markets. These activities have been transformative, however, by instilling a market ethos among public servants and a professional identity as business managers rather than as agents of social control. A case study of an American jurisdiction that attempted to privatise all of its youth justice institutions provides the data for this analysis

Language acquisition in developmental disorders

In this chapter, I review recent research into language acquisition in developmental disorders, and the light that these findings shed on the nature of language acquisition in typically developing children. Disorders considered include Specific Language Impairment, autism, Down syndrome, and Williams syndrome. I argue that disorders of language should be construed in terms of differences in the constraints that shape the learning process, rather than in terms of the normal system with components missing or malfunctioning. I outline the integrative nature of this learning process and how properties such as redundancy and compensation may be key characteristics of learning systems with atypical constraints. These ideas, as well as the new methodologies now being used to study variations in pathways of language acquisition, are illustrated with case studies from Williams syndrome and Specific Language Impairment

Bilingualism and the single route/dual route debate

The debate between single and dual route accounts of cognitive processes has been generated predominantly by the application of connectionist modeling techniques to two areas of psycholinguistics. This paper draws an analogy between this debate and bilingual language processing. A prominent question within bilingual word recognition is whether the bilingual has functionally separate lexicons for each language, or a single system able to recognize the words in both languages. Empirical evidence has been taken to support a model which includes two separate lexicons working in parallel (Smith, 1991; Gerard and Scarborough, 1989). However, a range of interference effects has been found between the bilingual’s two sets of lexical knowledge (Thomas, 1997a). Connectionist models have been put forward which suggest that a single representational resource may deal with these data, so long as words are coded according to language membership (Thomas, 1997a, 1997b, Dijkstra and van Heuven, 1998). This paper discusses the criteria which might be used to differentiate single route and dual route models. An empirical study is introduced to address one of these criteria, parallel access, with regard to bilingual word recognition. The study fails to find support for the dual route model

Theories that develop

The target article represents a significant advance in the level of sophistication applied to models of bilingual word recognition, and Dijkstra and van Heuven are to be congratulated on this endeavour. Bearing in mind the success of the (computational) BIA model in capturing detailed patterns of experimental data, I look forward to future simulation results from the BIA+ when the proposals of this new framework are implemented. It is an essential step to draw a distinction between recognition systems and the decision mechanisms that drive responses, and the authors have provided a novel way of apportioning empirical evidence of context effects in bilingual word recognition across this divide. Given the explanatory weight now being placed on decision mechanisms rather than the word recognition system itself, perhaps indeed it is now time to make some simplifying assumptions about the recognition system and start building detailed computational models of the decision component of the system. Implementation will provide the clarity of theorisation and evaluation of theory viability that have been the hallmark of the BIA model thus far

Ageing, plasticity, and cognitive reserve in connectionist networks

Neurocomputational modeling has suggested that a range of mechanisms can lead to reductions in functional plasticity across development (Thomas & Johnson, 2006). In this paper, we consider whether ageing might also produce a reduction in plasticity. Marchman’s (1993) model of damage and recovery in past tense formation was extended to incorporate the two main proposals for implementing effects of ageing: altered neuromodulation and connection loss. Simulations showed that ageing did reduce plasticity (as assessed by the system’s ability to recover from damage) but that effects were modulated by (a) the mechanism used to implement ageing, (b) problem type, and (c) pre-existing levels of cognitive reserve