Temperature distribution in a stellar atmosphere diagnostic basis

A stellar chromosphere is considered a region where the temperature increases outward and where the temperature structure of the gas controls the shape of the spectral lines. It is shown that lines which have collision-dominated source sink terms, like the Ca(+) and Mg(+) H and K lines, can be used to obtain the distribution of temperature with height from observed line profiles. Intrinsic emission lines and geometrical emission lines are found in spectral regions where the continuum is depressed. In visual regions, where the continuum is not depressed, emission core in absorption lines are attributed to reflections of intrinsic emission lines

Pattern formation in Hamiltonian systems with continuous spectra; a normal-form single-wave model

Pattern formation in biological, chemical and physical problems has received considerable attention, with much attention paid to dissipative systems. For example, the Ginzburg--Landau equation is a normal form that describes pattern formation due to the appearance of a single mode of instability in a wide variety of dissipative problems. In a similar vein, a certain "single-wave model" arises in many physical contexts that share common pattern forming behavior. These systems have Hamiltonian structure, and the single-wave model is a kind of Hamiltonian mean-field theory describing the patterns that form in phase space. The single-wave model was originally derived in the context of nonlinear plasma theory, where it describes the behavior near threshold and subsequent nonlinear evolution of unstable plasma waves. However, the single-wave model also arises in fluid mechanics, specifically shear-flow and vortex dynamics, galactic dynamics, the XY and Potts models of condensed matter physics, and other Hamiltonian theories characterized by mean field interaction. We demonstrate, by a suitable asymptotic analysis, how the single-wave model emerges from a large class of nonlinear advection-transport theories. An essential ingredient for the reduction is that the Hamiltonian system has a continuous spectrum in the linear stability problem, arising not from an infinite spatial domain but from singular resonances along curves in phase space whereat wavespeeds match material speeds (wave-particle resonances in the plasma problem, or critical levels in fluid problems). The dynamics of the continuous spectrum is manifest as the phenomenon of Landau damping when the system is ... Such dynamical phenomena have been rediscovered in different contexts, which is unsurprising in view of the normal-form character of the single-wave model

The Hamiltonian description of incompressible fluid ellipsoids

We construct the noncanonical Poisson bracket associated with the phase space of first order moments of the velocity field and quadratic moments of the density of a fluid with a free- boundary, constrained by the condition of incompressibility. Two methods are used to obtain the bracket, both based on Dirac's procedure for incorporating constraints. First, the Poisson bracket of moments of the unconstrained Euler equations is used to construct a Dirac bracket, with Casimir invariants corresponding to volume preservation and incompressibility. Second, the Dirac procedure is applied directly to the continuum, noncanonical Poisson bracket that describes the compressible Euler equations, and the moment reduction is applied to this bracket. When the Hamiltonian can be expressed exactly in terms of these moments, a closure is achieved and the resulting finite-dimensional Hamiltonian system provides exact solutions of Euler's equations. This is shown to be the case for the classical, incompressible Riemann ellipsoids, which have velocities that vary linearly with position and have constant density within an ellipsoidal boundary. The incompressible, noncanonical Poisson bracket differs from its counterpart for the compressible case in that it is not of Lie-Poisson form

Interventions targeted at primary care practitioners to improve the identification and referral of patients with co-morbid obesity: a realist review protocol

<b>Background </b>Obesity is one of the most significant public health challenges in the developed world. Recent policy has suggested that more can be done in primary care to support adults with obesity. In particular, general practitioners (GPs) and practice nurses (PNs) could improve the identification and referral of adults with obesity to appropriate weight management services. Previous interventions targeted at primary care practitioners in this area have had mixed results, suggesting a more complex interplay between patients, practitioners, and systems. The objectives of this review are (i) to identify the underlying ‘programme theory’ of interventions targeted at primary care practitioners to improve the identification and referral of adults with obesity and (ii) to explore how and why GPs and PNs identify and refer individuals with obesity, particularly in the context of weight-related co-morbidity. This protocol will explain the rationale for using a realist review approach and outline the key steps in this process. <p></p> <b>Methods</b> Realist review is a theory-led approach to knowledge synthesis that provides an explanatory analysis aimed at discerning what works, for whom, in what circumstances, how, and why. In this review, scoping interviews with key stakeholders involved in the planning and delivery of adult weight management services in Scotland helped to inform the identification of formal theories - from psychology, sociology, and implementation science - that will be tested as the review progresses. A comprehensive search strategy is described, including scope for iterative searching. Data analysis is outlined in three stages (describing context-mechanism-outcome configurations, exploring patterns in these configurations, and developing and testing middle-range theories, informed by the formal theories previously identified), culminating in the production of explanatory programme theory that considers individual, interpersonal, and institutional/systems-level components. <p></p> <b>Discussion </b>This is the first realist review that we are aware of looking at interventions targeted at primary care practitioners to improve the weight management of adults with obesity. Engagement with stakeholders at an early stage is a unique feature of realist review. This shapes the scope of the review, identification of candidate theories and dissemination strategies. The findings of this review will inform policy and future interventions. Systematic review registration PROSPERO CRD4201400939

Coming of age

Copyright at Demos 2011. This work is made available under the terms of the Demos licence.Britain’s ageing population is often described as a demographic time-bomb. As a society we often view ageing as a ‘problem’ which must be ‘managed’ – how to cope with the pressure on national health services of growing numbers of older people, the cost of sustaining them with pensions and social care, and the effect on families and housing needs. But ageing is not a policy problem to be solved. Instead it is a normal part of life, which varies according to personal characteristics, experience and outlook, and for many people growing older can be a very positive experience. Drawing on the Mass Observation project, one of the longest-running longitudinal life-writing projects anywhere in the world, Coming of Age grounds public policy in people’s real, lived experiences of ageing. It finds that the experience of ageing is changing, so that most people who are now reaching retirement do not identify themselves as old. One-size-fits-all policy approaches that treat older people as if they are all alike are alienating and inappropriate. Instead, older people need inclusive policy approaches that enable them to live their lives on their own terms. To ensure that older people are actively engaged, policy makers should stop emphasising the costs posed by an ageing population and start building on the many positive contributions that older people already make to our society.The Research Support and Development Office (RSDO) at Brunel University and the Economic and Social Research Council (ESRC

The role of primary care in adult weight management: qualitative interviews with key stakeholders in weight management services

Background: Primary care has a key role to play in the prevention and management of obesity, but there remain barriers to engagement in weight management by primary care practitioners. The aim of this study was to explore the views of key stakeholders in adult weight management services on the role of primary care in adult weight management. Methods: Qualitative study involving semi-structured interviews with nine senior dietitians involved in NHS weight management from seven Scottish health boards. Transcripts were analysed using an inductive thematic approach. Results: A range of tensions were apparent within three key themes: weight management service issues, the role of primary care, and communication with primary care. For weight management services, these tensions were around funding, the management model of obesity, and how to configure access to services. For primary care, they were around what primary care should be doing, who should be doing it, and where this activity should fit within wider weight management policy. With regard to communication between weight management services and primary care, there were tensions related to the approach taken (locally adapted versus centralised), the message being communicated (weight loss versus wellbeing), and the response from practitioners (engagement versus resistance). Conclusions: Primary care can do more to support adult weight management, but this requires better engagement and communication with weight management services, to overcome the tensions highlighted in this study. This, in turn, requires more secure, sustained funding. The example of smoking cessation in the UK, where there is a network of well-resourced NHS Stop Smoking Services, accessible via different means, could be a model to follow

The Deep SWIRE Field III. WIYN Spectroscopy

We present the results of spectroscopy using HYDRA on the WIYN 3.5m telescope of objects in the deep SWIRE radio field. The goal of the project was to determine spectroscopic redshifts for as many of the brighter objects in the field as possible, especially those detected in the radio and at 24 microns. These redshifts are primarily being used in studies of galaxy evolution and the connection of that evolution to AGN and star-formation. Redshifts measured for 365 individual objects are reported. The redshifts range from 0.03 to 2.5, mostly with z < 0.9. The sources were selected to be within the WIYN HYDRA field of approximately 30' in radius from the center of the SWIRE deep field, 10h46m00s, 59d 01'00" (J2000). Optical sources for spectroscopic observation were selected from a r-band image of the field. A priority list of spectroscopic targets was established in the following order: 20cm detections, 24 micron detections, galaxies with r < 20 and the balance made up of fainter galaxies in the field. We provide a table listing the galaxy positions, measured redshift and error, and note any emission lines that were visible in the spectrum. In practice almost all the galaxies with r < 19 were observed including all of the radio sources and most of the 24 microns sources with r < 20 and a sample of radio sources which had fainter optical counterparts on the r-band image.Comment: 6 pages, 3 tables, 2 figures, full electronic tables at http://www.aoc.nrao.edu/~fowen/papers/SWIRE/WIYNpaper3/, accepted ApJ Suppl Serie