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Born to be wide? Exploring correlations in mother and adolescent body mass index using data from the British household panel survey

The channels contributing to the intergenerational correlation in body mass are not well understood. Decomposition analysis is used to estimate the contribution of maternal characteristics, household income, and adolescent behaviours related to eating and physical activity on the intergenerational correlation in BMI. The analysis uses data on mothers and their adolescent children aged 11 to 15 from the British Household Panel Survey (2004 and 2006). The overall intergenerational correlation in BMI is 0.25. Maternal educational attainment and adolescent participation in some form of physical activity on a daily basis are the largest contributing factors to the intergenerational correlation in BMI. Maternal employment and more than four hours a day of television viewing by the adolescent are also important contributing factors. Overall, observable characteristics explain 11.2% of the intergenerational correlation in BMI

Going the same 'weigh': spousal correlations in obesity in the UK

The obesity epidemic has received widespread media and research attention. However, the social phenomenon of obesity is still not well understood. Data from the 2004 and 2006 waves of the British Household Panel Survey (BHPS) show positive and significant correlations in spousal body mass index (BMI). This paper explores three mechanisms of shared individual characteristics, social influence and shared environment to explain this correlation. A number of econometric specifications are used to investigate the role of observed individual characteristics, own health, spouse health, social influence, contextual effects and unobserved individual effects on the influence of these three hypotheses on the correlation in spousal BMI. Results indicate that social influence and shared individual characteristics, which may arise through assortative matching, both contribute to correlation in spousal BMI

Strategic Behaviour of Firms in a Duopoly and the Impact of Extending the Patenting Period

This paper deals with strategic behaviour of firms in a duopoly, subsequent to the claim by one firm that it has reduced the unit cost of production. A variety of possible strategic equilibria are discussed in the context of a duopoly game between a multinational and a local firm. In the context of an extended uniform period of patenting, as finally agreed in the Uruguay round (1994), firms have increased incentive to take patents. In the presence of cost differences, the act of taking process-patents has implications for the equilibrium output strategies of the duopoly firms and sometimes may have a negative overall welfare effect for the local producer and consumers

Analysing correlated noise on the surface code using adaptive decoding algorithms

Laboratory hardware is rapidly progressing towards a state where quantum error-correcting codes can be realised. As such, we must learn how to deal with the complex nature of the noise that may occur in real physical systems. Single qubit Pauli errors are commonly used to study the behaviour of error-correcting codes, but in general we might expect the environment to introduce correlated errors to a system. Given some knowledge of structures that errors commonly take, it may be possible to adapt the error-correction procedure to compensate for this noise, but performing full state tomography on a physical system to analyse this structure quickly becomes impossible as the size increases beyond a few qubits. Here we develop and test new methods to analyse blue a particular class of spatially correlated errors by making use of parametrised families of decoding algorithms. We demonstrate our method numerically using a diffusive noise model. We show that information can be learnt about the parameters of the noise model, and additionally that the logical error rates can be improved. We conclude by discussing how our method could be utilised in a practical setting blue and propose extensions of our work to study more general error models.Comment: 19 pages, 8 figures, comments welcome; v2 - minor typos corrected some references added; v3 - accepted to Quantu

Molecular weight effects on chain pull-out fracture of reinforced polymeric interfaces

Using Brownian dynamics, we simulate the fracture of polymer interfaces reinforced by diblock connector chains. We find that for short chains the interface fracture toughness depends linearly on the degree of polymerization $N$ of the connector chains, while for longer chains the dependence becomes $N^{3/2}$. Based on the geometry of initial chain configuration, we propose a scaling argument that accounts for both short and long chain limits and crossover between them.Comment: 5 pages, 3 figure