774 research outputs found

    Surface structure in simple liquid metals. An orbital free first principles study

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    Molecular dynamics simulations of the liquid-vapour interfaces in simple sp-bonded liquid metals have been performed using first principles methods. Results are presented for liquid Li, Na, K, Rb, Cs, Mg, Ba, Al, Tl, and Si at thermodynamic conditions near their respective triple points, for samples of 2000 particles in a slab geometry. The longitudinal ionic density profiles exhibit a pronounced stratification extending several atomic diameters into the bulk, which is a feature already experimentally observed in liquid K, Ga, In, Sn and Hg. The wavelength of the ionic oscillations shows a good scaling with the radii of the associated Wigner-Seitz spheres. The structural rearrangements at the interface are analyzed in terms of the transverse pair correlation function, the coordination number and the bond-angle distribution between nearest neighbors. The valence electronic density profile also shows (weaker) oscillations whose phase, with respect to those of the ionic profile, changes from opposite phase in the alkalis to almost in-phase for Si.Comment: 16 pages, 18 figures, 5 tables. Submitted to Phys. Rev.

    A global framework for action to improve the primary care response to chronic non-communicable diseases: a solution to a neglected problem.

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    BACKGROUND: Although in developing countries the burden of morbidity and mortality due to infectious diseases has often overshadowed that due to chronic non-communicable diseases (NCDs), there is evidence now of a shift of attention to NCDs. DISCUSSION: Decreasing the chronic NCD burden requires a two-pronged approach: implementation of the multisectoral policies aimed at decreasing population-level risks for NCDs, and effective and affordable delivery of primary care interventions for patients with chronic NCDs. The primary care response to common NCDs is often unstructured and inadequate. We therefore propose a programmatic, standardized approach to the delivery of primary care interventions for patients with NCDs, with a focus on hypertension, diabetes mellitus, chronic airflow obstruction, and obesity. The benefits of this approach will extend to patients with related conditions, e.g. those with chronic kidney disease caused by hypertension or diabetes. This framework for a "public health approach" is informed by experience of scaling up interventions for chronic infectious diseases (tuberculosis and HIV). The lessons learned from progress in rolling out these interventions include the importance of gaining political commitment, developing a robust strategy, delivering standardised interventions, and ensuring rigorous monitoring and evaluation of progress towards defined targets. The goal of the framework is to reduce the burden of morbidity, disability and premature mortality related to NCDs through a primary care strategy which has three elements: 1) identify and address modifiable risk factors, 2) screen for common NCDs and 3) and diagnose, treat and follow-up patients with common NCDs using standard protocols. The proposed framework for NCDs borrows the same elements as those developed for tuberculosis control, comprising a goal, strategy and targets for NCD control, a package of interventions for quality care, key operations for national implementation of these interventions (political commitment, case-finding among people attending primary care services, standardised diagnostic and treatment protocols, regular drug supply, and systematic monitoring and evaluation), and indicators to measure progress towards increasing the impact of primary care interventions on chronic NCDs. The framework needs evaluation, then adaptation in different settings. SUMMARY: A framework for a programmatic "public health approach" has the potential to improve on the current unstructured approach to primary care of people with chronic NCDs. Research to establish the cost, value and feasibility of implementing the framework will pave the way for international support to extend the benefit of this approach to the millions of people worldwide with chronic NCDs

    Effectiveness and reach of a directed-population approach to improving dental health and reducing inequalities: a cross sectional study

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    Background Childsmile School adopts a directed-population approach to target fluoride varnish applications to 20% of the primary one (P1) population in priority schools selected on the basis of the proportion of enrolled children considered to be at increased-risk of developing dental caries. The study sought to compare the effectiveness of four different methods for identifying individuals most in need when a directed-population approach is taken. <p></p> Methods The 2008 Basic National Dental Inspection Programme (BNDIP) cross-sectional P1 Scottish epidemiological survey dataset was used to model four methods and test three definitions of increased-risk. Effectiveness was determined by the positive predictive value (PPV) and explored in relation to 1-sensitivity and 1-specificity. <p></p> Results Complete data was available on 43470 children (87% of the survey). At the Scotland level, at least half (50%) of the children targeted were at increased-risk irrespective of the method used to target or the definition of increased-risk. There was no one method across all definitions of <i>increased-risk</i> that maximised PPV. Instead, PPV was highest when the targeting method complimented the definition of <i>increased-risk</i>. There was a higher percentage of children at <i>increased-risk</i> who were not targeted (1-sensitivity) when caries experience (rather than deprivation) was used to define <i>increased-risk</i>, irrespective of the method used for targeting. Over all three definitions of <i>increased-risk</i>, there was no one method that minimised (1-sensitivity) although this was lowest when the method and definition of <i>increased-risk</i> were complimentary. The false positive rate (1-specificity) for all methods and all definitions of <i>increased-risk</i> was consistently low (<20%), again being lowest when the method and definition of <i>increased-risk</i> were complimentary. <p></p> Conclusion Developing a method to reach all (or even the vast majority) of individuals at <i>increased-risk</i> defined by either caries experience or deprivation is difficult using a directed-population approach at a group level. There is a need for a wider debate between politicians and public health experts to decide how best to reach those most at need of intervention to improve health and reduce inequalities. <p></p&gt

    Phase separation transition in liquids and polymers induced by electric field gradients

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    Spatially uniform electric fields have been used to induce instabilities in liquids and polymers, and to orient and deform ordered phases of block-copolymers. Here we discuss the demixing phase transition occurring in liquid mixtures when they are subject to spatially nonuniform fields. Above the critical value of potential, a phase-separation transition occurs, and two coexisting phases appear separated by a sharp interface. Analytical and numerical composition profiles are given, and the interface location as a function of charge or voltage is found. The possible influence of demixing on the stability of suspensions and on inter-colloid interaction is discussed.Comment: 7 pages, 3 figures. Special issue of the J. Phys. Soc. Ja

    Adsorption Isotherms of Hydrogen: The Role of Thermal Fluctuations

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    It is shown that experimentally obtained isotherms of adsorption on solid substrates may be completely reconciled with Lifshitz theory when thermal fluctuations are taken into account. This is achieved within the framework of a solid-on-solid model which is solved numerically. Analysis of the fluctuation contributions observed for hydrogen adsorption onto gold substrates allows to determine the surface tension of the free hydrogen film as a function of film thickness. It is found to decrease sharply for film thicknesses below seven atomic layers.Comment: RevTeX manuscript (3 pages output), 3 figure

    Research on health transition in Africa: time for action

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    With rapidly increasing globalization, trends towards unhealthy diets, obesity, sedentary lifestyles and unhealthy habits are resulting in an increased worldwide burden of chronic non-communicable diseases (NCDs). In Africa this means that health systems face the challenge of an increasing burden of NCDs and of continuing high morbidity and mortality from communicable diseases. This health transition represents an enormous challenge to Africa as the region with the least resources for an effective response. Whereas previous epidemics, including HIV, have caught Africa unprepared, the opportunity now arises to take the advancing wave of health transition in Africa seriously. Health research has a key role to play in meeting health and development goals, and must be responsive to changing disease patterns, such as health transition. There is an urgent need for research on health transition in Africa to enable countries to respond effectively to rapidly changing health needs

    Distribution of hyperglycaemia and related cardiovascular disease risk factors in low-income countries: a cross-sectional population-based survey in rural Uganda

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    Background Data on non-communicable disease (NCD) burden are often limited in developing countries in Africa but crucial for planning and implementation of prevention and control strategies. We assessed the prevalence of related cardiovascular disease risk factors (hyperglycaemia, high blood pressure and obesity) in a longstanding population cohort in rural Uganda

    Regional contributions of six preventable risk factors to achieving the 25 × 25 non-communicable disease mortality reduction target: a modelling study

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    Background Countries have agreed to reduce premature mortality from the four main non-communicable diseases (NCDs) by 25% from 2010 levels by 2025 (referred to as the 25 × 25 target). Countries also agreed on a set of global voluntary targets for selected NCD risk factors. Previous analyses have shown that achieving the risk factor targets can contribute substantially towards meeting the 25 × 25 mortality target at the global level. We estimated the contribution of achieving six of the globally agreed risk factor targets towards meeting the 25 × 25 mortality target by region. Methods We estimated the eff ect of achieving the targets for six risk factors (tobacco and alcohol use, salt intake, obesity, and raised blood pressure and glucose) on NCD mortality between 2010 and 2025. Our methods accounted for multicausality of NCDs and for the fact that, when risk factor exposure increases or decreases, the harmful or benefi cial eff ects on NCDs accumulate gradually. We used data for risk factor and mortality trends from systematic analyses of available country data. Relative risks for the eff ects of individual and multiple risks, and for change in risk after decreases or increases in exposure, were from reanalyses and meta-analyses of epidemiological studies. Findings The probability of dying between the ages 30 years and 70 years from the four main NCDs in 2010 ranged from 19% in the region of the Americas to 29% in southeast Asia for men, and from 13% in Europe to 21% in southeast Asia for women. If current trends continue, the probability of dying prematurely from the four main NCDs is projected to increase in the African region but decrease in the other fi ve regions. If the risk factor targets are achieved, the 25 × 25 target will be surpassed in Europe in both men and women, and will be achieved in women (and almost achieved in men) in the western Pacifi c; the regions of the Americas, the eastern Mediterranean, and southeast Asia will approach the target; and the rising trend in Africa will be reversed. In most regions, a more ambitious approach to tobacco control (50% reduction relative to 2010 instead of the agreed 30%) will contribute the most to reducing premature NCD mortality among men, followed by addressing raised blood pressure and the agreed tobacco target. For women, the highest contributing risk factor towards the premature NCD mortality target will be raised blood pressure in every region except Europe and the Americas, where the ambitious (but not agreed) tobacco reduction would have the largest benefi t. Interpretation No WHO region will meet the 25 × 25 premature mortality target if current mortality trends continue. Achieving the agreed targets for the six risk factors will allow some regions to meet the 25 × 25 target and others to approach it. Meeting the 25 × 25 target in Africa needs other interventions, including those addressing infectionrelated cancers and cardiovascular disease

    The health of women and girls determines the health and well-being of our modern world: A White Paper From the International Council on Women's Health Issues

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    The International Council on Women's Health Issues (ICOWHI) is an international nonprofit association dedicated to the goal of promoting health, health care, and well-being of women and girls throughout the world through participation, empowerment, advocacy, education, and research. We are a multidisciplinary network of women's health providers, planners, and advocates from all over the globe. We constitute an international professional and lay network of those committed to improving women and girl's health and quality of life. This document provides a description of our organization mission, vision, and commitment to improving the health and well-being of women and girls globally

    A translational framework for public health research

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    <p><b>Background</b></p> <p>The paradigm of translational medicine that underpins frameworks such as the Cooksey report on the funding of health research does not adequately reflect the complex reality of the public health environment. We therefore outline a translational framework for public health research.</p> <p><b>Discussion</b></p> <p>Our framework redefines the objective of translation from that of institutionalising effective interventions to that of improving population health by influencing both individual and collective determinants of health. It incorporates epidemiological perspectives with those of the social sciences, recognising that many types of research may contribute to the shaping of policy, practice and future research. It also identifies a pivotal role for evidence synthesis and the importance of non-linear and intersectoral interfaces with the public realm.</p> <p><b>Summary</b></p> <p>We propose a research agenda to advance the field and argue that resources for 'applied' or 'translational' public health research should be deployed across the framework, not reserved for 'dissemination' or 'implementation'.</p&gt
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