The radial distributions of a heavy-light meson on a lattice

In an earlier work, the charge (vector) and matter (scalar) radial distributions of heavy-light mesons were measured in the quenched approximation on a 16^3 times 24 lattice with a quark-gluon coupling of 5.7, a lattice spacing of 0.17 fm, and a hopping parameter corresponding to a light quark mass about that of the strange quark. Several improvements are now made: 1) The configurations are generated using dynamical fermions with a quark-gluon coupling of 5.2 (a lattice spacing of 0.14 fm); 2) Many more gauge configurations are included (78 compared with the earlier 20); 3) The distributions at many off-axis, in addition to on-axis, points are measured; 4) The data-analysis is much more complete. In particular, distributions involving excited states are extracted. The exponential decay of the charge and matter distributions can be described by mesons of mass 0.9+-0.1 and 1.5+-0.1 GeV respectively - values that are consistent with those of vector and scalar qqbar-states calculated directly with the same lattice parameters.Comment: 3 pages, 4 figures, Lattice2002(heavyquark

The development of socioeconomic inequalities in anxiety and depression symptoms over the lifecourse

Purpose: Socioeconomic inequalities in anxiety and depression widen with increasing age. This may be due to differences in the incidence or persistence of symptoms. This paper investigates the widening of inequalities in anxiety and depression over the lifecourse. Methods: Data were from the West of Scotland Twenty-07 Study, constituting three cohorts aged approximately 16, 36 and 56 years at baseline and re-visited at 5-yearly intervals for 20 years. Symptoms were measured using the Hospital Anxiety and Depression Scale. Adjusting for age and sex, multilevel models with pairs of interviews (n = 6,878) nested within individuals (n = 3,165) were used for each cohort to estimate associations between current symptoms and education or household social class for both those with and without earlier symptoms, approximating socioeconomic differences in incidence and persistence. Results: Inequalities in current symptom levels were present for both those with and without earlier symptoms. In the youngest cohort, those with less education were more likely to experience persistent depression and to progress from anxiety to depression. At older ages there were educational and social class differences in both the persistence and incidence of symptoms, though there was more evidence of differential persistence than incidence in the middle cohort and more evidence of differential incidence than persistence in the oldest cohort. Conclusions: Differential persistence and symptom progression indicate that intervening to prevent or treat symptoms earlier in life is likely to reduce socioeconomic inequalities later, but attention also needs to be given to late adulthood where differential incidence emerges more strongly than differential persistence

Computational aerothermodynamics

Computational aerothermodynamics (CAT) has in the past contributed to the understanding of real-gas flows encountered by hypervelocity reentry vehicles. With advances in computational fluid dynamics, in the modeling of high temperature phenomena, and in computer capability, CAT is an enabling technology for the design of many future space vehicles. An overview of the current capabilities of CAT is provided by describing available methods and their applications. Technical challenges that need to be met are discussed

Can lattice data for two heavy-light mesons be understood in terms of simply two-quark potentials?

By comparing lattice data for the two heavy-light meson system (Q^2 qbar^2) with a standard many-body approach employing only interquark potentials, it is shown that the use of unmodified two-quark potentials leads to a gross overestimate of the binding energy.Comment: Contribution to LATTICE99 (Heavy Quarks). 3 pages, 2 ps figure

Adaptation vs authenticity: achieving leader effectiveness in intercultural encounters with followers–towards an integrated model

Previous research on leader effectiveness in intercultural encounters has focused on the ‘cultural congruence proposition’ which indicates that leaders from one culture encountering followers from a different culture should modify their behaviour away from their own values towards the collective values of the followers in order to enhance their effectiveness. This proposition appears to contradict the basic tenets of authentic leadership theory which indicate that effective leaders align their behaviour strictly with their own values. This paper proposes a theoretical model which draws upon each perspective and integrates them to reconcile this apparent conflict. The model suggests that effective cross cultural leaders use both self-regulation and their cultural intelligence to engender optimum ratings from their followers

A Study of Degenerate Four-quark states in SU(2) Lattice Monte Carlo

The energies of four-quark states are calculated for geometries in which the quarks are situated on the corners of a series of tetrahedra and also for geometries that correspond to gradually distorting these tetrahedra into a plane. The interest in tetrahedra arises because they are composed of {\bf three } degenerate partitions of the four quarks into two two-quark colour singlets. This is an extension of earlier work showing that geometries with {\bf two} degenerate partitions (e.g.\ squares) experience a large binding energy. It is now found that even larger binding energies do not result, but that for the tetrahedra the ground and first excited states become degenerate in energy. The calculation is carried out using SU(2) for static quarks in the quenched approximation with $\beta=2.4$ on a $16^3\times 32$ lattice. The results are analysed using the correlation matrix between different euclidean times and the implications of these results are discussed for a model based on two-quark potentials.Comment: Original Raw PS file replace by a tarred, compressed and uuencoded PS fil

Timing of poverty in childhood and adolescent health: Evidence from the US and UK

Childhood poverty is associated with poorer adolescent health and health behaviours, but the importance of the timing of poverty remains unclear. There may be critical or sensitive periods in early life or early adolescence, or poverty may have cumulative effects throughout childhood. Understanding when poverty is most important can support efficient timing of interventions to raise family income or buffer against the effects of low income, but answers may vary across social contexts. The US and the UK are a useful comparison with similar liberal approaches to cash transfers, but very different approaches to healthcare provision. Utilising data from large population studies in the US (n = 9408; born 1979–1996) and UK (n = 1204; born 1991–1997), this study employs a structured life course approach to compare competing hypotheses about the importance of the timing or pattern of childhood exposure to poverty in predicting adolescent health limitations, symptoms of psychiatric distress, and smoking at age 16 (age 15/16 in US). Household income histories identified experience of poverty (measured as <60% of the national median equivalised income for a given year) in early life (ages 0–5), mid-childhood (ages 6–10) and early adolescence (ages 11–15). The Bayesian Information Criterion (BIC) compared fit across models with variables representing different life course patterns of exposure to poverty. Adolescent distress was not associated with poverty in either country. In both countries, however, variables representing cumulative or persistent experiences of poverty exhibited optimal fit of all poverty exposure variables in predicting adolescent smoking and health limitations. There was also evidence of an early life sensitive period for smoking in the US. Poverty was more persistent in the US, but associations between poverty and outcomes were consistent across countries. Although poverty can have cumulative effects on health and behaviour, early interventions may offer the best long-term protection