64 research outputs found

    Weak-Field Gravity of Circular Cosmic Strings

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    A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string externally supported against collapse. The solution exhibits a conical singularity, and the corresponding deficit angle is the same as for a straight string of the same linear energy density. This confirms the deficit-angle assumption made in the Frolov-Israel-Unruh derivation of the metric describing a string loop at a moment of time symmetry.Comment: 15 page

    Submanifolds in five-dimensional pseudo-Euclidean spaces and four-dimensional FRW universes

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    Equations for submanifolds, which correspond to embeddings of the four-dimensional FRW universes in five-dimensional pseudo-Euclidean spaces, are presented in convenient form in general case. Several specific examples are considered.Comment: 7 pages, LaTeX, the mathematical part of this paper is based on the withdrawn preprint arXiv:1012.0320 [gr-qc

    Weak-Field Gravity of Revolving Circular Cosmic Strings

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    A weak-field solution of Einstein's equations is constructed. It is generated by a circular cosmic string revolving in its plane about the centre of the circle. (The revolution is introduced to prevent the string from collapsing.) This solution exhibits a conical singularity, and the corresponding deficit angle is the same as for a straight string of the same linear energy density, irrespective of the angular velocity of the string.Comment: 13 pages, LaTe

    Associations of sedentary behaviour, physical activity, blood pressure and anthropometric measures with cardiorespiratory fitness in children with cerebral palsy

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    Background - Children with cerebral palsy (CP) have poor cardiorespiratory fitness in comparison to their peers with typical development, which may be due to low levels of physical activity. Poor cardiorespiratory fitness may contribute to increased cardiometabolic risk. Purpose - The aim of this study was to determine the association between sedentary behaviour, physical activity and cardiorespiratory fitness in children with CP. An objective was to determine the association between cardiorespiratory fitness, anthropometric measures and blood pressure in children with CP. Methods- This study included 55 ambulatory children with CP [mean (SD) age 11.3 (0.2) yr, range 6-17 yr; Gross Motor Function Classification System (GMFCS) levels I and II]. Anthropometric measures (BMI, waist circumference and waist-height ratio) and blood pressure were taken. Cardiorespiratory fitness was measured using a 10 m shuttle run test. Children were classified as low, middle and high fitness according to level achieved on the test using reference curves. Physical activity was measured by accelerometry over 7 days. In addition to total activity, time in sedentary behaviour and light, moderate, vigorous, and sustained moderate-to-vigorous activity (≥10 min bouts) were calculated. Results - Multiple regression analyses revealed that vigorous activity (β = 0.339, p<0.01), sustained moderate-to-vigorous activity (β = 0.250, p<0.05) and total activity (β = 0.238, p<0.05) were associated with level achieved on the shuttle run test after adjustment for age, sex and GMFCS level. Children with high fitness spent more time in vigorous activity than children with middle fitness (p<0.05). Shuttle run test level was negatively associated with BMI (r2 = -0.451, p<0.01), waist circumference (r2 = -0.560, p<0.001), waist-height ratio (r2 = -0.560, p<0.001) and systolic blood pressure (r2 = -0.306, p<0.05) after adjustment for age, sex and GMFCS level. Conclusions - Participation in physical activity, particularly at a vigorous intensity, is associated with high cardiorespiratory fitness in children with CP. Low cardiorespiratory fitness is associated with increased cardiometabolic risk

    The functional, social and economic impact of acute encephalitis syndrome in Nepal--a longitudinal follow-up study.

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    notes: PMCID: PMC3772013Open Access JournalOver 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families.Wellcome TrustUniversity of Liverpool Clinical Fellowshi

    An inter-country comparison of unofficial payments: results of a health sector social audit in the Baltic States

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    <p>Abstract</p> <p>Background</p> <p>Cross-country comparisons of unofficial payments in the health sector are sparse. In 2002 we conducted a social audit of the health sector of the three Baltic States.</p> <p>Methods</p> <p>Some 10,320 household interviews from a stratified, last-stage-random, sample of 30 clusters per country, together with institutional reviews, produced preliminary results. Separate focus groups of service users, nurses and doctors interpreted these findings. Stakeholder workshops in each country discussed the survey and focus group results.</p> <p>Results</p> <p>Nearly one half of the respondents did not consider unofficial payments to health workers to be corruption, yet one half (Estonia 43%, Latvia 45%, Lithuania 64%) thought the level of corruption in government health services was high. Very few (Estonia 1%, Latvia 3%, Lithuania 8%) admitted to making unofficial payments in their last contact with the services. Around 14% of household members across the three countries gave gifts in their last contact with government services.</p> <p>Conclusion</p> <p>This social audit allowed comparison of perceptions, attitudes and experience regarding unofficial payments in the health services of the three Baltic States. Estonia showed least corruption. Latvia was in the middle. Lithuania evidenced the most unofficial payments, the greatest mistrust towards the system. These findings can serve as a baseline for interventions, and to compare each country's approach to health service reform in relation to unofficial payments.</p

    Atrial fibrillation and heart failure: Factors influencing the choice of oral anticoagulant.

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    Atrial fibrillation (AF) and heart failure (HF) frequently coexist. AF is identified in approximately one third of patients with HF and is linked to increased morbidity and mortality than from either condition alone. AF is relatively more common in HF with preserved ejection fraction (HFpEF) than with reduced ejection fraction (HFrEF). Nevertheless, the risk of stroke and systemic embolism (SSE) is significantly increased with both HF types and the absolute risk is heavily influenced by the presence and severity of associated additional stroke risk factors. The European Society of Cardiology has very recently introduced a third HF subtype entitled HF with mid-range ejection fraction (HFmrEF). At present oral anticoagulation is recommended for all patients with AF and HF, independent of HF type. In addition to warfarin there are currently four non-vitamin K oral anticoagulants (NOACs, previously called novel oral anticoagulants) that have been approved for the prevention of SSE. They consist of one direct thrombin inhibitor, dabigatran and three factor Xa inhibitors: rivaroxaban, apixaban and, most recently, edoxaban. In this review article we present an overview of the evidence to support the use of NOACs for the prevention of SSE in patients with AF and HF and review the influence of HF subtype and co-morbidities on the potential choice of oral anticoagulant

    A review of the psychological and familial perspectives of childhood obesity

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