89 research outputs found

    Dissipative hydrodynamics of relativistic shock waves in a Quark Gluon Plasma: comparing and benchmarking alternate numerical methods

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    This paper presents numerical cross-comparisons and benchmark results for two different kinetic numerical methods, capable of describing relativistic dissipative fluid dynamics in a wide range of kinematic regimes, typical of relevant physics applications, such as transport phenomena in quark-gluon plasmas. We refer to relativistic lattice Boltzmann versus Montecarlo Test-Particle methods. Lacking any realistic option for accurate validation vis-a-vis experimental data, we check the consistency of our results against established simulation packages available in the literature. We successfully cross-compare the results of the two aforementioned numerical approaches for momentum integrated quantities like the hydrostatic and dynamical pressure profiles, the collective flow and the heat flux. These results corroborate the confidence on the robustness and correctness of these computational methods and on the accurate calibration of their numerical parameters with respect to the physical transport coefficients. Our numerical results are made available as supplemental material, with the aim of establishing a reference benchmark for other numerical approaches

    SI-Lab Annual Research Report 2020

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    The Signal & Images Laboratory (http://si.isti.cnr.it/) is an interdisciplinary research group in computer vision, signal analysis, smart vision systems and multimedia data understanding. It is part of the Institute for Information Science and Technologies of the National Research Council of Italy. This report accounts for the research activities of the Signal and Images Laboratory of the Institute of Information Science and Technologies during the year 2020

    Measurements of daily energy intake and total energy expenditure in people with dementia in care homes: the use of wearable technology.

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    Objectives: To estimate daily total energy expenditure (TEE) using a physical activity monitor, combined with dietary assessment of energy intake to assess the relationship between daily energy expenditure and patterns of activity with energy intake in people with dementia living in care homes. Design and setting: A cross-sectional study in care homes in the UK. Participants: Twenty residents with confirmed dementia diagnosis were recruited from two care homes that specialised in dementia care. Measurements: A physical activity monitor (Sensewear TM Armband , Body Media, Pittsburgh, PA) was employed to objectively determine total energy expenditure, sleep duration and physical activity. The armband was placed around the left upper triceps for up to 7 days. Energy intake was determined by weighing all food and drink items over 4 days (3 weekdays and 1 weekend day) including measurements of food wastage. Results: The mean age was 78.7 (SD ± 11.8) years, Body Mass Index (BMI) 23.0 (SD ± 4.2) kg/m2 ; 50% were women. Energy intake (mean 7.4; SD ± 2.6) MJ/d) was correlated with TEE (mean 7.6; SD ± 1.8 MJ/d; r=0.49, p<0.05). Duration of sleeping ranged from 0.4-12.5 (mean 6.1) hrs/d and time spent lying down was 1.3-16.0 (8.3) hrs/d. On average residents spent 17.9 (6.3-23.4) hrs/d undertaking sedentary activity. TEE was correlated with BMI (r=0.52, p<0.05) and body weight (r=0.81, p<0.001) but inversely related to sleep duration (r=-0.59, p<0.01) and time lying down (r=-0.62, p<0.01). Multiple linear regression analysis revealed that after taking BMI, sleep duration and time spent lying down into account, TEE was no longer correlated with energy intake. Conclusions: The results show the extent to which body mass, variable activity and sleep patterns may be contributing to TEE and together with reduced energy intake, energy requirements were not satisfied. Thus wearable technology has the potential to offer real-time monitoring to provide appropriate nutrition management that is more person-centred to prevent weight loss in dementi

    Social and environmental factors associated with the hospitalization of tuberculosis patients

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    OBJECTIVE: to identify social and environmental factors associated with hospitalization of tuberculosis (TB) patients in Manaus, Amazonas, during 2010. METHODS: this is a quantitative cross-sectional epidemiological study, with primary data collection and analysis of human immunodeficiency virus (HIV), based on seropositive status. RESULTS: Among social factors for TB-HIV co-infection, the association between alcohol use and dependence was significant for employed workers; among non-co-infections, the association between income less than one minimum wage (U.S. $200) and retired people, Bolsa Família Program [Family Allowance]/other social benefits was significant. Regarding environmental factors, the association was significant for TB-HIV co-infection among those not having their own house, having masonry housing and daily garbage collection; and among non-co-infection, owning their own house, no masonry housing and lack of daily garbage collection was significant. CONCLUSION: The findings indicated that not only social factors, but also environmental ones are associated with hospitalization of tuberculosis patients, and such associations differ according to TB-HIV co-infection. Findings revealed that the non-biological factors associated with hospitalization of tuberculosis patients should be considered when caring patients with this disease

    Identification of Financial Factors in Economic Fluctuations

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    We estimate demand, supply, monetary, investment and financial shocks in a VAR identified with a minimum set of sign restrictions on US data. We find that financial shocks are major drivers of fluctuations in output, stock prices and investment but have a limited effect on inflation. In a second step we disentangle shocks originating in the housing sector, shocks originating in credit markets and uncertainty shocks. In the extended set-up financial shocks are even more important and a leading role is played by housing shocks that have large and persistent effects on output.publishedVersio
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