Assessment of physical activity among primary school aged children: the Children's Leisure Activities Study (CLASS)

Overweight and obesity rates among children in Australia have increased twofold in the last decade. Physical activity is thought to play an important role in the prevention and treatment of childhood obesity. Children's physical activity data in Australia are incomplete and mainly based on parental proxy reports. One of the reasons for the lack of children's physical activity prevalence data in Australia is the difficulties of measurement. The aim of this study was to develop and examine a reliable, valid and feasible method for assessing physical activity among primary school aged children. A total of 112 grade 5 and 6 children and their parents were recruited from four state primary schools in the eastern and western suburbs of Melbourne. The test-retest reliability of a parental proxy physical activity questionnaire and a children's self report physical activity questionnaire was assessed. The criterion validity of the questionnaires was assessed using accelerometry. Findings suggest that the self report and proxy report questionnaires provided reliable measures of the type, frequency and duration of children's physical activity behaviour. Overall, the criterion validity of the questionnaires was poor. Although accelerometry as an objective measure shows promise, it does not provide the important physical activity behavioural and contextual information that is critical for the development of strategies to promote physical activity among children. We recommend that a combination of self report or proxy and objective measurement (using accelerometry or even pedometry) appears to be the current 'best buy' in the assessment of children's physical activity behaviour.

Troubling identities : teacher education students' constructions of class and ethnicity

This paper reports on a research project that explored how student teachers understand ethnic and classed difference as it relates to themselves and their students. Discourses of schooling can shape students ethnic and classed identities, frequently positioning non-mainstream students as 'other' and marginalizing them. Significant numbers of our teacher education students have limited experience of diverse educational settings, having mainly attended white middle-class schools as students and as student teachers. Working with diverse student populations productively depends on teachers recognising and valuing difference. The ways in which they engage with students whose ethnic and classed identities are different from their own is important in creating learning environments that build on and engage with diversity.

In a preliminary stage of the research we asked eight third-year teacher education students to explore their own ethnic and classed identities. The complexities of identity are foregrounded in both the assumptions we made in selecting particular students for the project and in the ways they did (not) think about themselves as having ethnic or classed identities.

In this paper we draw on these findings to interrogate how categories of identity are fluid, shifting and ongoing processes of negotiation: troubling and complex. We also consider the implications for teacher education.

Surviving suppression : no detectable impacts of Class A foam on soil invertebrates and some Australian native plants

Firefighting foams (Class A foams) are an effective and widespread firefighting tool which are frequently used in environmentally sensitive areas. Firefighting foams are known to be ecologically damaging in aquatic environments, however their impacts at the plant species or ecosystem level are relatively unknown. Reports of shoot damage to plants, suppressed flowering, and changes in plant community composition suggested that the ecological damage caused by their use may be unacceptable. However, applications of foam to seedlings of some Australian plant species from representative and widespread families, showed no detectable impacts on a range of vegetative growth characteristics. Application of 1.0% foam to heathland soils showed no detectable impacts on soil invertebrate Orders sampled over several months. The results are encouraging for the continued use of Class A foam as a fire suppression technique.

Ethnicity, social class, practice and pedagogy : a study of teacher identity

This paper draws on findings from three separate research projects to illustrate how teachers’ and student-teachers’ ethnic and social class identities shape theirrepresentations of professional self, their interactions with their students and the pedagogies they privilege in their classes. The paper raises a number of important implications for teacher education seeking to prepare teachers for culturally diverse contexts such as Australian classrooms. It concludes that a major challenge for teacher educators is to find ways of enabling their students to interrogate often taken-for-granted assumptions about their own ethnic and classed positionings.

"Sins of their fathers" : culturally at risk children and the colonial state in Asia

In contact with their foreign surroundings, European enclaves throughout imperial Asia and Africa formed new cultural communities. Nevertheless, over time as Cooper and Stoler (1997) have argued, such colonial communities became subject to the same bourgeois project as experienced in the metropolitan centres to which they remained connected. If, in terms of that project, metropolitan European society was deemed vulnerable from a brutish and unruly working class, these colonial outposts of Western society were even more vulnerable to what was deemed to be the more insidious dangers of miscegenation and cultural hybridity. Where nineteenth century educators typically suggested that working class children were “at risk” of not being able to benefit from, and simultaneously representing “a risk to”, the emerging opportunities of bourgeois capitalist society, this “risk” was accentuated in the colonies by the additional category of race. Focussing on the question of children of mixed parentage as a category of “children at risk”, this paper examines the way educationists and politicians responded to what was perceived as “civilisational decline” in four such communities - the Dutch East Indies, British India, (British) Australia and French Indo-China - to demonstrate the universality of these concerns in Imperial Asia.

Experienced teachers' perspectives on cultural and social class diversity : which differences matter?

This article reports on a pilot study that investigated the beliefs, values, and pedagogies of experienced high school teachers who worked with student populations of non-English speaking and economically disadvantaged immigrants or refugees in Australia. Qualitative research methods, including focus groups and in-depth individual interviews with teachers, produced data that were examined using Critical Discourse Analysis. Close reading of the teachers' comments suggests that there are a number of key discourses that teachers use to make sense of differences among culturally diverse and economically disadvantaged groups of students. Specifically, teachers distinguish between cultural groups on the basis of students' life experiences prior to arrival in Australia; students' collective and individual educational experiences; and the different social class positioning of students within the same ethnic group. In their comments, teachers at times categorised students in generalised and stereotypical ways but also were able to critique and reflect on their personal assumptions. An analysis of the teachers' reflections provides insights into how they made sense of “diversity” and how, as teachers, they try to work productively with ethnically diverse and economically disadvantaged students.

The Australian class structure and Australian politics 1931 - 40

This paper presents the results of an analysis of the class structure of interwar Australia based largely on the 1933 Commonwealth census. It reviews previous analyses by academics but although contemporary journalists and political strategists. It develops an estimate of the class composition of the electorate as distinct from the general population and attempts to define the class position of voters outside of the paid workforce. It considers the question of to what extent Labor needed non-working-class votes to secure an electoral majority and how the differing social composition of the Australian states impacted on electoral outcomes and Labor strategies. It employs the method of bounds to develop some preliminary conclusions about the electoral behaviour of different social groups and concludes with some observations on the divided nature of the Australian working class and the competing strategies that parties developed in their search for an electoral majority.

Book review : Class act : Melbourne Workers Theatre 1987 - 2007

The article reviews the book "Class Act: Melbourne Workers Theatre 1987-2007," edited by Glenn D'Cruz.

A class of modified variable step-size NLMS algorithms for system identification

This paper proposes a class of modified variable step-size normalized least mean square (VS NLMS) algorithms. The class of schemes are obtained from estimating the optimum step-size of NLMS that minimizes the mean square deviation (MSD). During the estimation, we consider the properties of the additive noise and the input excitation together. The developed class of VS NLMS algorithms have simple forms and give improved tradeoff of fast convergence rate and low misadjustment in system identification.

Education and the colonial construction of whiteness

European imperialism spawned settlements of invasive white communities throughout Asia and Africa. Stoler and Cooper (1997: 27) argue these evolving colonial societies became subject to what amounts to an extended bourgeois project such that "we can not understand the construction of whiteness without exploring its class dimensions". If in terms of that project, nineteenth-century metropolitan society was deemed vulnerable to the ravages of a brutish and unruly working class, these white colonial outposts, whether constituted as settler colonies or colonies of exploitation, were even more vulnerable to the more insidious danger of miscegenation. Racial intermingling became simultaneously an issue of class and race. Imperialism therefore added a further dimension to the on-going detinition of "bourgeois-ness": the discourse of whiteness transforming a national discourse into a discourse on civilisation.

In focusing on education as the colonial authorities' response to what they perceived of as the danger of mixed parentage, this article develops a comparative framework that links coloniai settlements in Asia and Australia. It examines the discourse surrounding miscegenation, education and the "rising generation" in the late nineteenth and early twentieth centuries in the Dutch East Indies British India, French Indo China and (British) Australia. In so doing, I demonstrate the universality of a linked discourse of whiteness and class across Imperial Asia.

Adaptive fast finite time control of a class of uncertain nonlinear systems

This paper concerns the adaptive fast finite time control of a class of nonlinear uncertain systems of which the upper bounds of the system uncertainties are unknown. By using the fast non-smooth control Lyapunov function and the method of so-called adding a power integrator merging with adaptive technique, a recursive design procedure is provided, which guarantees the fast finite time stability of the closed-loop system. It is proved that the control input is bounded, and a simulation example is given to illustrate the effectiveness of the theoretical results.