A universal constraint between charge and rotation rate for degenerate black holes surrounded by matter

We consider stationary, axially and equatorially symmetric systems consisting of a central rotating and charged degenerate black hole and surrounding matter. We show that $a^2+Q^2=M^2$ always holds provided that a continuous sequence of spacetimes can be identified, leading from the Kerr-Newman solution in electrovacuum to the solution in question. The quantity $a=J/M$ is the black hole's intrinsic angular momentum per unit mass, $Q$ its electric charge and $M$ the well known black hole mass parameter introduced by Christodoulou and Ruffini.Comment: 19 pages, 2 figures, replaced with published versio

Workshop on Techtonic Evolution of Greenstone Belts

Topics addressed include: greenstone belt externalities; boundaries; rock terranes; synthesis and destiny; tectonic evolution; rock components and structure; sedimentology; stratigraphy; volcanism; metamorphism; and geophysics

Phonons from neutron powder diffraction

The spherically averaged structure function \soq obtained from pulsed neutron powder diffraction contains both elastic and inelastic scattering via an integral over energy. The Fourier transformation of \soq to real space, as is done in the pair density function (PDF) analysis, regularizes the data, i.e. it accentuates the diffuse scattering. We present a technique which enables the extraction of off-center phonon information from powder diffraction experiments by comparing the experimental PDF with theoretical calculations based on standard interatomic potentials and the crystal symmetry. This procedure (dynamics from powder diffraction(DPD)) has been successfully implemented for two systems, a simple metal, fcc Ni, and an ionic crystal, CaF$_{2}$. Although computationally intensive, this data analysis allows for a phonon based modeling of the PDF, and additionally provides off-center phonon information from powder neutron diffraction

Lower cardiorespiratory fitness contributes to increased insulin resistance and fasting glycaemia in middle-aged South Asian compared with European men living in the UK

AIMS/HYPOTHESIS: This study aimed to determine the extent to which increased insulin resistance and fasting glycaemia in South Asian men, compared with white European men, living in the UK, was due to lower cardiorespiratory fitness (maximal oxygen uptake [[Formula: see text]]) and physical activity. METHODS: One hundred South Asian and 100 age- and BMI-matched European men without diagnosed diabetes, aged 40–70 years, had fasted blood taken for measurement of glucose concentration, HOMA-estimated insulin resistance (HOMA(IR)), plus other risk factors, and underwent assessment of physical activity (using accelerometry), [Formula: see text], body size and composition, and demographic and other lifestyle factors. For 13 South Asian and one European man, HbA(1c) levels were >6.5% (>48 mmol/mol), indicating potential undiagnosed diabetes; these men were excluded from the analyses. Linear regression models were used to determine the extent to which body size and composition, fitness and physical activity variables explained differences in HOMA(IR) and fasting glucose between South Asian and European men. RESULTS: HOMA(IR) and fasting glucose were 67% (p < 0.001) and 3% (p < 0.018) higher, respectively, in South Asians than Europeans. Lower [Formula: see text], lower physical activity and greater total adiposity in South Asians individually explained 68% (95% CI 45%, 91%), 29% (11%, 46%) and 52% (30%, 80%), respectively, and together explained 83% (50%, 119%) (all p < 0.001) of the ethnic difference in HOMA(IR). Lower [Formula: see text] and greater total adiposity, respectively, explained 61% (9%, 111%) and 39% (9%, 76%) (combined effect 63% [8%, 115%]; all p < 0.05) of the ethnic difference in fasting glucose. CONCLUSIONS/INTERPRETATION: Lower cardiorespiratory fitness is a key factor associated with the excess insulin resistance and fasting glycaemia in middle-aged South Asian, compared with European, men living in the UK. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00125-013-2969-y) contains peer-reviewed but unedited supplementary material, which is available to authorised users

Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or

ICF-based Functional Components and Contextual Factors as Correlates of Perceived Quality of Life for Youth With Chronic Conditions

Purpose: To explore International Classification of Functioning, Disability and Health (ICF)-based functional components and contextual factors associated with perceived quality of life (QOL) for youth with chronic conditions from the perspective of youth and parents. Method: Baseline data were obtained from a longitudinal study examining predictors of changes in perceived QOL for youth with chronic conditions. 439 youth aged 11–17 (and one of their parents) completed a questionnaire. Standardized tools were used to measure youth functioning, contextual factors and perceived QOL. Multivariate linear regression analyses, controlling for socio-demographic and health information, were conducted to explore correlations among youth functioning/contextual factors and youth and parent perceptions of youth QOL. Results: Significant (p0.05) negative correlates with both youth and parent perceptions of youth QOL included pain/other physical symptoms and emotional symptoms. Significant factors positively correlated with youth and parent perceptions of youth QOL included school productivity and spirituality. Other significant positive correlates of youth perspectives were family social support and school belongingness/safety. Family functioning was positively correlated, and youth social anxiety and environmental barriers were negatively correlated, with parent perceptions of youth QOL. Conclusions: This study provides preliminary evidence of factors upon which services aimed at improving perceived QOL of youth with chronic conditions could be based