944 research outputs found

    A systematic review of mental health and wellbeing outcomes of group singing for adults with a mental health condition

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    Background A growing body of research has found that participating in choir singing can increase positive emotions, reduce anxiety and enhance social bonding. Consequently, group singing has been proposed as a social intervention for people diagnosed with mental health problems. However, it is unclear if group singing is a suitable and effective adjunct to mental health treatment. The current paper systematically reviews the burgeoning empirical research on the efficacy of group singing as a mental health intervention. Methods The literature searched uncovered 709 articles that were screened. Thirteen articles representing data from 667 participants were identified which measured mental health and/or wellbeing outcomes of group singing for people living with a mental health condition in a community setting. Results The findings of seven longitudinal studies, showed that while people with mental health conditions participated in choir singing, their mental health and wellbeing significantly improved with moderate to large effect sizes. Moreover, six qualitative studies had converging themes, indicating that group singing can provide enjoyment, improve emotional states, develop a sense of belonging and enhance self-confidence in participants. Conclusion The current results indicate that group singing could be a promising social intervention for people with mental health conditions. However, these studies had moderate to high risk of bias. Therefore, these findings remain inconclusive and more rigorous research is needed

    The perceived effects of singing on the health and wellbeing of wives and partners of members of the British Armed Forces: a cross-sectional survey

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    Objectives A survey to explore the extent to which a choir programme associated with the British Armed Forces provides benefits of wives and partners and families of military personnel. Study design A cross-sectional survey. Method Online self-completion questionnaires to survey 464 choir members and 173 committee members who were also participants in the choirs. Results Large majorities of participants report personal and social benefits from their engagement in choirs, as well as benefits for their health and wellbeing. Challenges facing choirs were also identified associated with performance demands and inter-personal relationships within choirs. Conclusions Group singing generates a range of personal, social and health benefits for wives and partners of armed services personnel. The study reveals some challenges arising in all female choirs in military settings and suggests potential areas for further research

    Slip-velocity of large neutrally-buoyant particles in turbulent flows

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    We discuss possible definitions for a stochastic slip velocity that describes the relative motion between large particles and a turbulent flow. This definition is necessary because the slip velocity used in the standard drag model fails when particle size falls within the inertial subrange of ambient turbulence. We propose two definitions, selected in part due to their simplicity: they do not require filtration of the fluid phase velocity field, nor do they require the construction of conditional averages on particle locations. A key benefit of this simplicity is that the stochastic slip velocity proposed here can be calculated equally well for laboratory, field, and numerical experiments. The stochastic slip velocity allows the definition of a Reynolds number that should indicate whether large particles in turbulent flow behave (a) as passive tracers; (b) as a linear filter of the velocity field; or (c) as a nonlinear filter to the velocity field. We calculate the value of stochastic slip for ellipsoidal and spherical particles (the size of the Taylor microscale) measured in laboratory homogeneous isotropic turbulence. The resulting Reynolds number is significantly higher than 1 for both particle shapes, and velocity statistics show that particle motion is a complex non-linear function of the fluid velocity. We further investigate the nonlinear relationship by comparing the probability distribution of fluctuating velocities for particle and fluid phases

    Lagrangian filtered density function for LES-based stochastic modelling of turbulent dispersed flows

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    The Eulerian-Lagrangian approach based on Large-Eddy Simulation (LES) is one of the most promising and viable numerical tools to study turbulent dispersed flows when the computational cost of Direct Numerical Simulation (DNS) becomes too expensive. The applicability of this approach is however limited if the effects of the Sub-Grid Scales (SGS) of the flow on particle dynamics are neglected. In this paper, we propose to take these effects into account by means of a Lagrangian stochastic SGS model for the equations of particle motion. The model extends to particle-laden flows the velocity-filtered density function method originally developed for reactive flows. The underlying filtered density function is simulated through a Lagrangian Monte Carlo procedure that solves for a set of Stochastic Differential Equations (SDEs) along individual particle trajectories. The resulting model is tested for the reference case of turbulent channel flow, using a hybrid algorithm in which the fluid velocity field is provided by LES and then used to advance the SDEs in time. The model consistency is assessed in the limit of particles with zero inertia, when "duplicate fields" are available from both the Eulerian LES and the Lagrangian tracking. Tests with inertial particles were performed to examine the capability of the model to capture particle preferential concentration and near-wall segregation. Upon comparison with DNS-based statistics, our results show improved accuracy and considerably reduced errors with respect to the case in which no SGS model is used in the equations of particle motion

    Simultaneous 3D measurement of the translation and rotation of finite size particles and the flow field in a fully developed turbulent water flow

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    We report a novel experimental technique that measures simultaneously in three dimensions the trajectories, the translation, and the rotation of finite size inertial particles together with the turbulent flow. The flow field is analyzed by tracking the temporal evolution of small fluorescent tracer particles. The inertial particles consist of a super-absorbent polymer that renders them index and density matched with water and thus invisible. The particles are marked by inserting at various locations tracer particles into the polymer. Translation and rotation, as well as the flow field around the particle are recovered dynamically from the analysis of the marker and tracer particle trajectories. We apply this technique to study the dynamics of inertial particles much larger in size (Rp/{\eta} \approx 100) than the Kolmogorov length scale {\eta} in a von K\'arm\'an swirling water flow (R{\lambda} \approx 400). We show, using the mixed (particle/fluid) Eulerian second order velocity structure function, that the interaction zone between the particle and the flow develops in a spherical shell of width 2Rp around the particle of radius Rp. This we interpret as an indication of a wake induced by the particle. This measurement technique has many additional advantages that will make it useful to address other problems such as particle collisions, dynamics of non-spherical solid objects, or even of wet granular matter.Comment: 18 pages, 7 figures, submitted to "Measurement Science and Technology" special issue on "Advances in 3D velocimetry

    Holocene evolution in weathering and erosion patterns in the Pearl River delta

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    Author Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 14 (2013); 2349–2368, doi:10.1002/ggge.20166.Sediments in the Pearl River delta have the potential to record the weathering response of this river basin to climate change since 9.5 ka, most notably weakening of the Asian monsoon since the Early Holocene (∼8 ka). Cores from the Pearl River delta show a clear temporal evolution of weathering intensity, as measured by K/Al, K/Rb, and clay mineralogy, that shows deposition of less weathered sediment at a time of weakening monsoon rainfall in the Early-Mid Holocene (6.0–2.5 ka). This may reflect an immediate response to a less humid climate, or more likely reduced reworking of older deposits from river terraces as the monsoon weakened. Human settlement of the Pearl River basin may have had a major impact on landscape and erosion as a result of the establishment of widespread agriculture. After around 2.5 ka weathering intensity sharply increased, despite limited change in the monsoon, but at a time when anthropogenic pollutants (e.g., Cu, Zn, and Pb) increased and when the flora of the basin changed. 87Sr/86Sr covaries with these other proxies but is also partly influenced by the presence of carbonate. The sediments in the modern Pearl River are even more weathered than the youngest material from the delta cores. We infer that the spread of farming into the Pearl River basin around 2.7 ka was followed by a widespread reworking of old, weathered soils after 2.5 ka, and large-scale disruption of the river system that was advanced by 2.0 ka.We acknowledge financial support from the Swire Educational Trust and South China Sea Institute of Oceanology PhD Funding (Grant No. MSGL09-06).2014-01-2

    Risk assessment of released cellulose nanocrystals – mimicking inhalatory exposure

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    Cellulose nanocrystals (CNCs) exhibit advantageous chemical and mechanical properties that render them attractive for a wide range of applications. During the life-cycle of CNC containing materials the nanocrystals could be released and become airborne, posing a potential inhalatory exposure risk towards humans. Absent reliable and dose-controlled models that mimic this exposure in situ is a central issue in gaining an insight into the CNC-lung interaction. Here, an Air Liquid Interface Cell Exposure system (ALICE), previously designed for studies of spherical nanoparticles, was used for the first time to establish a realistic physiological exposure test method for inhaled fiber shaped nano-objects; in this case, CNCs isolated from cotton. Applying a microscopy based approach the spatially homogenous deposition of CNCs was demonstrated as a prerequisite of the functioning of the ALICE. Furthermore, reliability and controllability of the system to nebulise high aspect ratio nanomaterials (HARN, e.g. CNCs) was shown. This opens the potential to thoroughly investigate the inhalatory risk of CNCs in vitro using a realistic exposure system

    Maternal mental health:a key area for future research among women with congenital heart disease

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    In this viewpoint, we respond to the recently published national priorities for research in congenital heart disease (CHD) among adults, established through the James Lind Alliance Priority Setting Partnership, with specific attention to priority 3 (mental health) and priority 5 (maternal health). Our recent policy impact project explored how maternal mental health is currently addressed in adult congenital heart disease (ACHD) services in the National Health Service, identified gaps and discussed possible ways forward. Our multidisciplinary discussion groups, which included women with lived experience of CHD and pregnancy, cardiology and obstetrics clinicians and medical anthropologists, found that while pregnancy and the postnatal period increase the mental health challenges faced by women with CHD, current services are not yet equipped to address them. Based on this work, we welcome the prioritisation of both mental health and maternal health in ACHD, and suggest that future research should focus on the overlaps between these two priority areas
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