Assessing time knowledge in children aged 10 to 11 years

The acquisition of time knowledge involves learning how to read clocks, estimate time, read dates and learn about temporal sequences. Evidence suggests that many of these competencies are acquired by 10 years of age although not all children may follow this developmental path. The main purpose of this study was to collect normative data for a screening tool that assesses time knowledge. These data identify the prevalence and pattern of difficulties with time knowledge among a UK sample of Year 6 pupils (aged 10 to 11 years). The Time Screening Assessment tool (Doran, Dutt & Pembery, 2015), designed to assess time knowledge, was administered individually to a sample of 79 children. Findings revealed a median overall score of 32 out of a maximum score of 36. 25% of children performed at or close to ceiling, however seven children scored more than -1.5 standard deviations below the mean. The value of these findings to practitioners working with children in schools is discussed

Rethinking context : Realisation, instantiation and individuation in Systemic Functional Linguistics

In spite of decades of research developing a model of language and context, there is little consensus in systemic functional linguistics (SFL) about how context should be modelled and how language and context are related. In this paper, we review recent work in SFL which focuses on modelling register as a resource – reconceiving field as a resource for construing phenomena, tenor as a resource for negotiating social relations, and mode as a resource for composing texture. This work has a number of implications for SFL’s conception of realisation (as strata of abstraction), instantiation (as a cline of generalisation), and individuation (as a scale of belonging). For realisation it bears critically on the issue of whether or not to adopt a stratified model of context (as register and genre) and the relationship between extrinsic functionality (field, tenor, and mode) and intrinsic functionality (ideational, interpersonal, and textual metafunctions). For instantiation, it bears critically on our modelling of principles for coupling (co-selecting and arranging choices within and across languages and related modalities of communication) – for example mass, presence, and association. And for individuation, it bears critically on the perspectives of allocation (i.e. how access to meanings and their uptake is distributed across communities) and affiliation (i.e. how meanings are used to collaborate and struggle, within and between social groups). Our basic aim in this paper is to suggest a model for improving traction as far as SFL work on language in context is concerned, fully embracing a multimodal perspective on language and related modalities of communication as resources for meaning

New Techniques for Analysing Axisymmetric Gravitational Systems. 1. Vacuum Fields

A new framework for analysing the gravitational fields in a stationary, axisymmetric configuration is introduced. The method is used to construct a complete set of field equations for the vacuum region outside a rotating source. These equations are under-determined. Restricting the Weyl tensor to type D produces a set of equations which can be solved, and a range of new techniques are introduced to simplify the problem. Imposing the further condition that the solution is asymptotically flat yields the Kerr solution uniquely. The implications of this result for the no-hair theorem are discussed. The techniques developed here have many other applications, which are described in the conclusions.Comment: 30 pages, no figure

Quadratic Lagrangians and Topology in Gauge Theory Gravity

We consider topological contributions to the action integral in a gauge theory formulation of gravity. Two topological invariants are found and are shown to arise from the scalar and pseudoscalar parts of a single integral. Neither of these action integrals contribute to the classical field equations. An identity is found for the invariants that is valid for non-symmetric Riemann tensors, generalizing the usual GR expression for the topological invariants. The link with Yang-Mills instantons in Euclidean gravity is also explored. Ten independent quadratic terms are constructed from the Riemann tensor, and the topological invariants reduce these to eight possible independent terms for a quadratic Lagrangian. The resulting field equations for the parity non-violating terms are presented. Our derivations of these results are considerably simpler that those found in the literature

The Demand for Beef in Indonesia: Implications for Australian Agribusiness

Meat consumption and socio-demographic data from the 1990, 1993 and 1996 SUSENAS Household Food Expenditure and Consumption Surveys were employed to estimate the demand for meats in Indonesia. The focus was on the Provinces of DKI Jakarta and West Java where about one-fourth of the Indonesian population reside. Statistical and econometric procedures were used to aggregate the 16 meat types recorded in the SUSENAS into four Meat Groups. They were then used to estimate the Linear Approximation of the Almost Ideal Demand System (LA/AIDS) model, taking into account zero observations and the restrictions on budget shares. The demand for Meat Group 1 (with the dominant meat, beef) is income-inelastic, whereas for Meat Group 2 (with the dominant meat, commercial and native chicken) it is income-elastic. These two groups comprise nearly 95 per cent of all meat purchases. The estimated own-price elasticity of the beef group is -0.92, while that for the chicken group is -1.09. The cross-price elasticities indicate that all the meat groups are substitute goods, as expected. The results suggest that the current focus of the Indonesian government on strengthening the domestic poultry industry is well placed, as the demand for chicken is likely to respond more quickly to income growth than the demand for beef. Further, consumers seem more likely to adapt their chicken consumption patterns to price changes than they do for beef. However, these differences are relatively minor and there is still a major opportunity for Australian agribusiness firms in the cattle and beef sectors to take advantage of the projected rapid growth in Indonesian beef demand.beef demand, almost ideal demand system, commodity aggregation, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Early Dark Energy Cosmologies

We propose a novel parameterization of the dark energy density. It is particularly well suited to describe a non-negligible contribution of dark energy at early times and contains only three parameters, which are all physically meaningful: the fractional dark energy density today, the equation of state today and the fractional dark energy density at early times. As we parameterize Omega_d(a) directly instead of the equation of state, we can give analytic expressions for the Hubble parameter, the conformal horizon today and at last scattering, the sound horizon at last scattering, the acoustic scale as well as the luminosity distance. For an equation of state today w_0 < -1, our model crosses the cosmological constant boundary. We perform numerical studies to constrain the parameters of our model by using Cosmic Microwave Background, Large Scale Structure and Supernovae Ia data. At 95% confidence, we find that the fractional dark energy density at early times Omega_early < 0.06. This bound tightens considerably to Omega_early < 0.04 when the latest Boomerang data is included. We find that both the gold sample of Riess et. al. and the SNLS data by Astier et. al. when combined with CMB and LSS data mildly prefer w_0 < -1, but are well compatible with a cosmological constant.Comment: 6 pages, 3 figures; references added, matches published versio

Effective Symmetries of the Minimal Supermultiplet of N = 8 Extended Worldline Supersymmetry

A minimal representation of the N = 8 extended worldline supersymmetry, known as the `ultra-multiplet', is closely related to a family of supermultiplets with the same, E(8) chromotopology. We catalogue their effective symmetries and find a Spin(4) x Z(2) subgroup common to them all, which explains the particular basis used in the original construction. We specify a constrained superfield representation of the supermultiplets in the ultra-multiplet family, and show that such a superfield representation in fact exists for all adinkraic supermultiplets. We also exhibit the correspondences between these supermultiplets, their Adinkras and the E(8) root lattice bases. Finally, we construct quadratic Lagrangians that provide the standard kinetic terms and afford a mixing of an even number of such supermultiplets controlled by a coupling to an external 2-form of fluxes.Comment: 13 Figure

Specht modules and semisimplicity criteria for Brauer and Birman--Murakami--Wenzl Algebras

A construction of bases for cell modules of the Birman--Murakami--Wenzl (or B--M--W) algebra $B_n(q,r)$ by lifting bases for cell modules of $B_{n-1}(q,r)$ is given. By iterating this procedure, we produce cellular bases for B--M--W algebras on which a large abelian subalgebra, generated by elements which generalise the Jucys--Murphy elements from the representation theory of the Iwahori--Hecke algebra of the symmetric group, acts triangularly. The triangular action of this abelian subalgebra is used to provide explicit criteria, in terms of the defining parameters $q$ and $r$, for B--M--W algebras to be semisimple. The aforementioned constructions provide generalisations, to the algebras under consideration here, of certain results from the Specht module theory of the Iwahori--Hecke algebra of the symmetric group