Bayesian palaeoclimate reconstruction

Summary.  We consider the problem of reconstructing prehistoric climates by using fossil data that have been extracted from lake sediment cores. Such reconstructions promise to provide one of the few ways to validate modern models of climate change. A hierarchical Bayesian modelling approach is presented and its use, inversely, is demonstrated in a relatively small but statistically challenging exercise: the reconstruction of prehistoric climate at Glendalough in Ireland from fossil pollen. This computationally intensive method extends current approaches by explicitly modelling uncertainty and reconstructing entire climate histories. The statistical issues that are raised relate to the use of compositional data (pollen) with covariates (climate) which are available at many modern sites but are missing for the fossil data. The compositional data arise as mixtures and the missing covariates have a temporal structure. Novel aspects of the analysis include a spatial process model for compositional data, local modelling of lattice data, the use, as a prior, of a random walk with long-tailed increments, a two-stage implementation of the Markov chain Monte Carlo approach and a fast approximate procedure for cross-validation in inverse problems. We present some details, contrasting its reconstructions with those which have been generated by a method in use in the palaeoclimatology literature. We suggest that the method provides a basis for resolving important challenging issues in palaeoclimate research. We draw attention to several challenging statistical issues that need to be overcome.     

The Legal Status of Turks in Germany

Turks in Germany constitute the single largest non-national group living in the member states of the European Union. This essay examines the legal dimensions of their entry, residence and integration in Germany during the 1990s up to 2002. The evidence shows that, despite long-term settlement patterns, Turks in Germany have not achieved a high level of formal inclusion. However, recent policy reforms have already gone some way to improving their situation, and the impact of planned reforms should equally ensure that this process continues in the future.     

Bayesian variable selection and regularization for time–frequency surface estimation

Summary.  We describe novel Bayesian models for time–frequency inverse modelling of non-stationary signals. These models are based on the idea of a Gabor regression , in which a time series is represented as a superposition of translated, modulated versions of a window function exhibiting good time–frequency concentration. As a necessary consequence, the resultant set of potential predictors is in general overcomplete—constituting a frame rather than a basis—and hence the resultant models require careful regularization through appropriate choices of variable selection schemes and prior distributions. We introduce prior specifications that are tailored to representative time series, and we develop effective Markov chain Monte Carlo methods for inference. To highlight the potential applications of such methods, we provide examples using two of the most distinctive time–frequency surfaces—speech and music signals—as well as standard test functions from the wavelet regression literature.     

The politics of disability and access: the Sydney 2000 Games experience

The article examines disability and access issues surrounding the Sydney 2000 Olympic and Paralympic Games. Central to this is an examination of the involvement of the Australian community of people with disabilities [1] within the Games. The Sydney Paralympic Games, in particular, was seen as a possible watershed event for developing accessible infrastructure, and raising awareness of disability and access issues. This paper draws on the official documents of the Games, newspaper accounts and disability organisation reports. The article first examines the major bodies charged with organising the Games, and the planning processes used to incorporate disability and access issues. It then examines a range of critical issues and their relationships with the disability community. Finally, the article provides an analysis of any likely legacies that the 2000 Games may have for Sydney's community of people with disabilities.     

Beyond normalization and impairment: theorizing subjectivity in learning difficulties – theory and practice

Normalization and social role valorization continue to play a central role in shaping debates and practice relating to learning difficulties. In the context of recent arguments this paper draws on the work of Foucault to deconstruct these theories. Foucault’s work alerts us to a conceptual confusion at their heart which reproduces a common but problematic individual–society dualism. There is an implicit, and problematic, presence in the theories of a pre‐social individual conceived as having essential impairments and who is passive in the face of negative socialization. We propose that Foucault’s ‘ethical’ domain of inquiry, with its concern for how people actively understand themselves and govern their conduct in relation to specific values and a ‘truth’ that they are obliged to recognize in themselves, provides the basis for returning the individual‐as‐subject to theories in an active, critical manner.     

Evaluating the Efficacy of a Mental Models Approach for Improving Occupational Chemical Risk Protection

Chemical risk protection in the workplace relies partly on informing workers about possible risks using material safety data sheets (MSDS). This article reports on phase 2 of a project (phase 1 reported in Cox et al.), which employed a mental models approach to improve on data sheets as communicative interventions for perchloroethylene in dry cleaning and rosin-based solder flux in the electronics industry within small businesses in the United Kingdom (small enterprises (SEs) < 25 employees in the workplace). It focuses on the efficacy of a multimethod evaluation strategy to assess (1) the capacity of a mental models approach to yield contextually relevant data for intervention design and (2) the effectiveness of the strategy itself in validating the mental models data. The evaluation was conducted using postal questionnaires and semi-structured verbal protocols to provide responses to the alternative intervention content and to prioritize risk messages. User discussion groups were then employed, particularly as a means of establishing whether contextual information could be obtained that would differ qualitatively from the kind elicited through individual (semi) structured methods. We conclude that the mental models approach as part of an iterative process including systematic multimethod evaluation is successful in supporting the design of relevant communications to the users of chemicals. The overall viability of communicative interventions in the context of health and safety in small businesses remains in question. Future research might aim to develop a more holistic approach to interventions in complex occupational contexts.     

Employment, family union and childbearing decisions in Great Britain

Summary.  The paper investigates the life-cycle relationship of work and family life in Britain based on the British Household Panel Survey. Using hazard regression techniques we estimate a five-equation model, which includes birth events, union formation, union dissolution, employment and non-employment events. We find that transitions in and out of employment for men are relatively independent of other transitions. In contrast, there are strong links between employment of females, having children and union formation. By undertaking a detailed microsimulations analysis, we show that different levels of labour force participation by females do not necessarily lead to large changes in fertility events. Changes in union formation and fertility events, in contrast, have larger effects on employment.     

Parents,Perceptions and Belonging: Exploring Flexible Working among UK Fathers and Mothers

This paper advances knowledge regarding how fathers and mothers perceive and experience flexible working opportunities. It does this through applying the theoretical concept ‘belonging’ to ‘Parsonian’ classifications of parenting and work. In so doing it makes transparent the misconceptions and inequities which exist among parents and their organizational environments. Focusing initially on a qualitative study of fathers’ experience of working flexibly, the paper shows how fathers felt marginalized from the possibilities of flexible work due to line managers’ assumptions that men belonged to an ‘instrumental’ economic provider group. The paper contributes a new angle to debate by articulating how fathers perceived employed mothers as belonging to an ‘expressive’ child‐oriented group, with privileged access to flexibility. However, drawing upon a study of maternity and flexible work we query fathers’ assumptions that flexibility was easily available to mothers, suggesting that fathers’ perceptions of maternal privilege were misconceived. While mothers were categorized as belonging within an ‘expressive’ group associated with childcare, they were nevertheless discouraged from accessing flexibility. Inequities between women and men (with regard to flexibility) thus appeared to be less significant than fathers supposed.     

‘Just teach us the skills please,we'll do the rest’: empowering ten‐year‐olds as active researchers

This paper discusses the outcomes of an initiative to empower ten‐year‐olds as active researchers. It debates some of the barriers that are commonly cited with regard to children of this age taking ownership of their own research agendas—power relations, competence, knowledge and skills—and challenges the status quo. It describes a study in which a group of ten‐year‐olds participated in a taught programme aimed at equipping them with the knowledge and skills to design their own research. This empowering process resulted in the children undertaking research projects of their own choosing, designed, carried out and reported entirely from their perspective. Reports from two of those projects are presented as part of this paper.