Dynamics of gravity driven three-dimensional thin films on hydrophilic-hydrophobic patterned substrates

We investigate numerically the dynamics of unstable gravity driven three-dimensional thin liquid films on hydrophilic-hydrophobic patterned substrates of longitudinal stripes and checkerboard arrangements. The thin film can be guided preferentially on hydrophilic longitudinal stripes, while fingers develop on adjacent hydrophobic stripes if their width is large enough. On checkerboard patterns, the film fingering occurs on hydrophobic domains, while lateral spreading is favoured on hydrophilic domains, providing a mechanism to tune the growth rate of the film. By means of kinematical arguments, we quantitatively predict the growth rate of the contact line on checkerboard arrangements, providing a first step towards potential techniques that control thin film growth in experimental setups.Comment: 30 pages, 12 figure

Complementary therapy use by patients and parents of children with asthma and the implications for NHS care: a qualitative study

BACKGROUND: Patients are increasingly using complementary therapies, often for chronic conditions. Asthma is the most common chronic condition in the UK. Previous research indicates that some asthma patients experience gaps in their NHS care. However, little attention has been given to how and why patients and parents of children with asthma use complementary therapies and the implications for NHS care. METHODS: Qualitative study, comprising 50 semi-structured interviews with a purposeful sample of 22 adults and 28 children with asthma (plus a parent), recruited from a range of NHS and non-NHS settings in Bristol, England. Data analysis was thematic, drawing on the principles of constant comparison. RESULTS: A range of complementary therapies were being used for asthma, most commonly Buteyko breathing and homeopathy. Most use took place outside of the NHS, comprising either self-treatment or consultation with private complementary therapists. Complementary therapies were usually used alongside not instead of conventional asthma treatment. A spectrum of complementary therapy users emerged, including "committed", "pragmatic" and "last resort" users. Motivating factors for complementary therapy use included concerns about conventional NHS care ("push factors") and attractive aspects of complementary therapies ("pull factors"). While participants were often uncertain whether therapies had directly helped their asthma, breathing techniques such as the Buteyko Method were most notably reported to enhance symptom control and enable reduction in medication. Across the range of therapies, the process of seeking and using complementary therapies seemed to help patients in two broad ways: it empowered them to take greater personal control over their condition rather than feel dependant on medication, and enabled exploration of a broader range of possible causes of their asthma than commonly discussed within NHS settings. CONCLUSION: Complementary therapy use reflects patients' and parents' underlying desire for greater self-care and need of opportunities to address some of their concerns regarding NHS asthma care. Self-management of chronic conditions is increasingly promoted within the NHS but with little attention to complementary therapy use as one strategy being used by patients and parents. With their desire for self-help, complementary therapy users are in many ways adopting the healthcare personas that current policies aim to encourage

Health effects of ambient air pollution – recent research development and contemporary methodological challenges

Exposure to high levels of air pollution can cause a variety of adverse health outcomes. Air quality in developed countries has been generally improved over the last three decades. However, many recent epidemiological studies have consistently shown positive associations between low-level exposure to air pollution and health outcomes. Thus, adverse health effects of air pollution, even at relatively low levels, remain a public concern. This paper aims to provide an overview of recent research development and contemporary methodological challenges in this field and to identify future research directions for air pollution epidemiological studies

Natural outdoor environments and mental health: Stress as a possible mechanism.

INTRODUCTION Better mental health has been associated with exposure to natural outdoor environments (NOE). However, comprehensive studies including several indicators of exposure and outcomes, potential effect modifiers and mediators are scarce. OBJECTIVES We used novel, objective measures to explore the relationships between exposure to NOE (i.e. residential availability and contact) and different indicators of mental health, and possible modifiers and mediators. METHODS A nested cross-sectional study was conducted in: Barcelona, Spain; Stoke-on-Trent, United Kingdom; Doetinchem, Netherlands; Kaunas, Lithuania. Participants' exposure to NOE (including both surrounding greenness and green and/or blue spaces) was measured in terms of (a) amount in their residential environment (using Geographical Information Systems) and (b) their contact with NOE (using smartphone data collected over seven days). Self-reported information was collected for mental health (psychological wellbeing, sleep quality, vitality, and somatisation), and potential effect modifiers (gender, age, education level, and city) and mediators (perceived stress and social contacts), with additional objective NOE physical activity (potential mediator) derived from smartphone accelerometers. RESULTS Analysis of data from 406 participants showed no statistically significant associations linking mental health and residential NOE exposure. However, NOE contact, especially surrounding greenness, was statistically significantly tied to better mental health. There were indications that these relationships were stronger for males, younger people, low-medium educated, and Doetinchem residents. Perceived stress was a mediator of most associations, and physical activity and social contacts were not. CONCLUSIONS Our findings indicate that contact with NOE benefits mental health. Our results also suggest that having contact with NOE that can facilitate stress reduction could be particularly beneficial

The association between greenness and traffic-related air pollution at schools

Greenness has been reported to improve mental and physical health. Reduction in exposure to air pollution has been suggested to underlie the health benefits of greenness; however, the available evidence on the mitigating effect of greenness on air pollution remains limited and inconsistent. We investigated the association between greenness within and surrounding school boundaries and monitored indoor and outdoor levels of traffic-related air pollutants (TRAPs) including NO2, ultrafine particles, black carbon, and traffic-related PM2.5 at 39 schools across Barcelona, Spain, in 2012. TRAP levels at schools were measured twice during two one-week campaigns separated by 6 months. Greenness within and surrounding school boundaries was measured as the average of satellite-derived normalized difference vegetation index (NDVI) within boundaries of school and a 50 m buffer around the school, respectively. Mixed effects models were used to quantify the associations between school greenness and TRAP levels, adjusted for relevant covariates. Higher greenness within and surrounding school boundaries was consistently associated with lower indoor and outdoor TRAP levels. Reduction in indoor TRAP levels was partly mediated by the reduction in outdoor TRAP levels. We also observed some suggestions for stronger associations between school surrounding greenness and outdoor TRAP levels for schools with higher number of trees around them. Our observed reduction of TRAP levels at schools associated with school greenness can be of public importance, considering the burden of health effects of exposure to TRAPs in schoolchildren