Towards DNS of the Ultimate Regime of Rayleigh--B\'enard Convection

In this contribution we have briefly introduced the problem of turbulent thermal convection with a particular look at its transition to the ultimate regime and the resolution requirements needed for the direct numerical simulation of this flow.Comment: 10 pages, 6 figure

Wall roughness induces asymptotic ultimate turbulence

Turbulence is omnipresent in Nature and technology, governing the transport of heat, mass, and momentum on multiple scales. For real-world applications of wall-bounded turbulence, the underlying surfaces are virtually always rough; yet characterizing and understanding the effects of wall roughness for turbulence remains a challenge, especially for rotating and thermally driven turbulence. By combining extensive experiments and numerical simulations, here, taking as example the paradigmatic Taylor-Couette system (the closed flow between two independently rotating coaxial cylinders), we show how wall roughness greatly enhances the overall transport properties and the corresponding scaling exponents. If only one of the walls is rough, we reveal that the bulk velocity is slaved to the rough side, due to the much stronger coupling to that wall by the detaching flow structures. If both walls are rough, the viscosity dependence is thoroughly eliminated in the boundary layers and we thus achieve asymptotic ultimate turbulence, i.e. the upper limit of transport, whose existence had been predicted by Robert Kraichnan in 1962 (Phys. Fluids {\bf 5}, 1374 (1962)) and in which the scalings laws can be extrapolated to arbitrarily large Reynolds numbers

Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation

Evaluation of Lay Support in Pregnant women with Social risk (ELSIPS): a randomised controlled trial

<p>Abstract</p> <p>Background</p> <p>Maternal, neonatal and child health outcomes are worse in families from black and ethnic minority groups and disadvantaged backgrounds. There is little evidence on whether lay support improves maternal and infant outcomes among women with complex social needs within a disadvantaged multi-ethnic population in the United Kingdom (UK).</p> <p>Method/Design</p> <p>The aim of this study is to evaluate a lay Pregnancy Outreach Worker (POW) service for nulliparous women identified as having social risk within a maternity service that is systematically assessing social risks alongside the usual obstetric and medical risks. The study design is a randomised controlled trial (RCT) in nulliparous women assessed as having social risk comparing standard maternity care with the addition of referral to the POW support service.</p> <p>The POWs work alongside community midwifery teams and offer individualised support to women to encourage engagement with services (health and social care) from randomisation (before 28 weeks gestation) until 6 weeks after birth.</p> <p>The primary outcomes have been chosen on the basis that they are linked to maternal and infant health. The two primary outcomes are engagement with antenatal care, assessed by the number of antenatal visits; and maternal depression, assessed using the Edinburgh Postnatal Depression Scale at 8-12 weeks after birth. Secondary outcomes include maternal and neonatal morbidity and mortality, routine child health assessments, including immunisation uptake and breastfeeding at 6 weeks. Other psychological outcomes (self efficacy) and mother-to-infant bonding will also be collected using validated tools.</p> <p>A sample size of 1316 will provide 90% power (at the 5% significance level) to detect increased engagement with antenatal services of 1.5 visits and a reduction of 1.5 in the average EPDS score for women with two or more social risk factors, with power in excess of this for women with any social risk factor. Analysis will be by intention to treat.</p> <p>Qualitative research will explore the POWs' daily work in context. This will complement the findings of the RCT through a triangulation of quantitative and qualitative data on the process of the intervention, and identify other contextual factors that affect the implementation of the intervention.</p> <p>Discussion</p> <p>The trial will provide high quality evidence as to whether or not lay support (POW) offered to women identified with social risk factors improves engagement with maternity services and reduces numbers of women with depression.</p> <p>MREC number</p> <p>10/H1207/23</p> <p>Trial registration number</p> <p>ISRCTN: <a href="http://www.controlled-trials.com/ISRCTN35027323">ISRCTN35027323</a></p

Air pollution and the microvasculature: A cross-sectional assessment of in vivo retinal images in the population-based multi-ethnic study of atherosclerosis (MESA)

10.1371/journal.pmed.1000372PLoS Medicine711

EBM in primary care: a qualitative multicenter study in Spain

<p>Abstract</p> <p>Background</p> <p>Evidence based medicine (EBM) has made a substantial impact on primary care in Spain over the last few years. However, little research has been done into family physicians (FPs)' attitudes related to EBM. The present study investigates FPs' perceptions of EBM in the primary care context.</p> <p>Methods</p> <p>This study used qualitative methodology. Information was obtained from 8 focus groups composed of 67 FPs from 47 health centers in 4 autonomous regions in Spain. Intentional sampling considered participants' previous education in EBM, and their experience as tutors in family medicine or working groups' members of the Spanish Society of Family Practice. Sociological discourse analysis was used with the support of the MAXqda software. Results were validated by means of triangulation among researchers and contrast with participants.</p> <p>Results</p> <p>Findings were grouped into three main areas: 1) The tug-of-war between the "science" of EBM and "experience" in the search for good clinical practice in primary care; 2) The development of EBM sensemaking as a reaction to contextual factors and interests; 3) The paradox of doubt and trust in the new EBM experts.</p> <p>The meaning of EBM was dynamically constructed within the primary care context. FPs did not consider good clinical practice was limited to the vision of science that EBM represents. Its use appeared to be conditioned by several factors that transcended the common concept of barriers. Along with concerns about its objectivity, participants showed a tendency to see EBM as the use of simplified guidelines developed by EBM experts.</p> <p>Conclusions</p> <p>The identification of science with EBM and its recognition as a useful but insufficient tool for the good clinical practice requires rethinking new meanings of evidence within the primary care reality. Beyond the barriers related to accessing and putting into practice the EBM, its reactive use can determine FPs' questions and EBM development in a direction not always centred on patients' needs. The questioning of experts' authority as a pillar of EBM could be challenged by the emergence of new kinds of EBM texts and experts to believe in.</p

Trigger finger: etiology, evaluation, and treatment

Trigger finger is a common finger aliment, thought to be caused by inflammation and subsequent narrowing of the A1 pulley, which causes pain, clicking, catching, and loss of motion of the affected finger. Although it can occur in anyone, it is seen more frequently in the diabetic population and in women, typically in the fifth to sixth decade of life. The diagnosis is usually fairly straightforward, as most patients complain of clicking or locking of the finger, but other pathological processes such as fracture, tumor, or other traumatic soft tissue injuries must be excluded. Treatment modalities, including splinting, corticosteroid injection, or surgical release, are very effective and are tailored to the severity and duration of symptoms

Socio-demographic and clinical characteristics of re-presentation to an Australian inner-city emergency department: implications for service delivery

BACKGROUND: People who have complex health care needs frequently access emergency departments for treatment of acute illness and injury. In particular, evidence suggests that those who are homeless, or suffer mental illness, or have a history of substance misuse, are often repeat users of emergency departments. The aim of this study was to describe the socio-demographic and clinical characteristics of emergency department re-presentations. Re-presentation was defined as a return visit to the same emergency department within 28 days of discharge from hospital. METHODS: A retrospective cohort study was conducted of emergency department presentations occurring over a 24-month period to an Australian inner-city hospital. Characteristics were examined for their influence on the binary outcome of re-presentation within 28 days of discharge using logistic regression with the variable patient fitted as a random effect. RESULTS: From 64,147 presentations to the emergency department the re-presentation rate was 18.0% (n = 11,559) of visits and 14.4% (5,894/40,942) of all patients. Median time to re-presentation was 6 days, with more than half occurring within one week of discharge (60.8%; n = 6,873), and more than three-quarters within two weeks (80.9%; n = 9,151). The odds of re-presentation increased three-fold for people who were homeless compared to those living in stable accommodation (adjusted OR 3.09; 95% CI, 2.83 to 3.36). Similarly, the odds of re-presentation were significantly higher for patients receiving a government pension compared to those who did not (adjusted OR 1.73; 95% CI, 1.63 to 1.84), patients who left part-way through treatment compared to those who completed treatment and were discharged home (adjusted OR 1.64; 95% CI, 1.36 to 1.99), and those discharged to a residential-care facility compared to those who were discharged home (adjusted OR 1.46: 95% CI, 1.03 to 2.06). CONCLUSION: Emergency department re-presentation rates cluster around one week after discharge and rapidly decrease thereafter. Housing status and being a recipient of a government pension are the most significant risk factors. Early identification and appropriate referrals for those patients who are at risk of emergency department re-presentation will assist in the development of targeted strategies to improve health service delivery to this vulnerable group