628 research outputs found
Edge momentum transport by neutrals: an interpretive numerical framework
Due to their high cross-field mobility, neutrals can contribute to momentum transport even at
the low relative densities found inside the separatrix and they can generate intrinsic rotation.
We use a charge-exchange dominated solution to the neutral kinetic equation, coupled to
neoclassical ions, to evaluate the momentum transport due to neutrals. Numerical solutions
to the drift-kinetic equation allow us to cover the full range of collisionality, including the
intermediate levels typical of the tokamak edge. In the edge there are several processes likely
to contribute to momentum transport in addition to neutrals. Therefore, we present here an
interpretive framework that can evaluate the momentum transport through neutrals based
on radial plasma profiles. We demonstrate its application by analysing the neutral angular
momentum flux for an L-mode discharge in the ASDEX Upgrade tokamak. The magnitudes of
the angular momentum fluxes we find here due to neutrals of 0.6
–
2
Nm
are comparable to the
net torque on the plasma from neutral beam injection, indicating the importance of neutrals for
rotation in the edge.Vetenskapsrådet and Marie Sklodowska Curie Actions, Cofund, Project INCA 60039
Incidence, remission and mortality of convulsive epilepsy in rural northeast South Africa
Background: Epilepsy is one of the most common neurological conditions globally, estimated to constitute 0.75% of the global burden of disease, with the majority of this burden found in low- and middle- income countries (LMICs). Few studies from LMICs, including much of sub-Saharan Africa, have described the incidence, remission or mortality rates due to epilepsy, which are needed to quantify the burden and inform policy. This study investigates the epidemiological parameters of convulsive epilepsy within a context of high HIV prevalence and an emerging burden of cardiovascular disease.
Methods: A cross-sectional population survey of 82,818 individuals, in the Agincourt Health and Socio-demographic Surveillance Site (HDSS) in rural northeast South Africa was conducted in 2008, from which 296 people were identified with active convulsive epilepsy. A follow-up survey was conducted in 2012. Incidence and mortality rates were estimated, with duration and remission rates calculated using the DISMOD II software package.
Results: The crude incidence for convulsive epilepsy was 17.4/100,000 per year (95%CI: 13.1-23.0). Remission was 4.6% and 3.9% per year for males and females, respectively. The standardized mortality ratio was 2.6 (95%CI: 1.7-3.5), with 33.3% of deaths directly related to epilepsy. Mortality was higher in men than women (adjusted rate ratio (aRR) 2.6 (95%CI: 1.2-5.4)), and was significantly associated with older ages (50+ years versus those 0-5 years old (RR 4.8 (95%CI: 0.6-36.4)).
Conclusions: The crude incidence was lower whilst mortality rates were similar to other African studies; however, this study found higher mortality amongst older males. Efforts aimed at further understanding what causes epilepsy in older people and developing interventions to reduce prolonged seizures are likely to reduce the overall burden of ACE in rural South Africa
Data Management Strategy to Improve Global Use of Ocean Acidification Data and Information
International audienceOcean acidification (OA) refers to the general decrease in pH of the global ocean as a result of absorbing anthropogenic CO2 emitted in the atmosphere since preindustrial times (Sabine et al., 2004). There is, however, considerable variability in ocean acidification, and many careful measurements need to be made and compared in order to obtain scientifically valid information for the assessment of patterns, trends, and impacts over a range of spatial and temporal scales, and to understand the processes involved. A single country or institution cannot undertake measurements of worldwide coastal and open ocean OA changes; therefore, international cooperation is needed to achieve that goal. The OA data that have been, and are being, collected represent a significant public investment. To this end, it is critically important that researchers (and others) around the world are easily able to find and use reliable OA information that range from observing data (from time-series moorings, process studies, and research cruises), to biological response experiments (e.g., mesocosm), data products, and model output. [...
Atrial fibrillation and thromboprophylaxis in heart failure: the need for patient-centered approaches to address adherence
Premature mortality of epilepsy in low- and middle-income countries: A systematic review from the Mortality Task Force of the International League Against Epilepsy
To determine the magnitude of risk factors and causes of premature mortality associated with epilepsy in low- and middle-income countries (LMICs). We conducted a systematic search of the literature reporting mortality and epilepsy in the World Bank-defined LMICs. We assessed the quality of the studies based on representativeness; ascertainment of cases, diagnosis, and mortality; and extracted data on standardized mortality ratios (SMRs) and mortality rates in people with epilepsy. We examined risk factors and causes of death. The annual mortality rate was estimated at 19.8 (range 9.7â45.1) deaths per 1,000 people with epilepsy with a weighted median SMR of 2.6 (range 1.3â7.2) among higher-quality population-based studies. Clinical cohort studies yielded 7.1 (range 1.6â25.1) deaths per 1,000 people. The weighted median SMRs were 5.0 in male and 4.5 in female patients; relatively higher SMRs within studies were measured in children and adolescents, those with symptomatic epilepsies, and those reporting less adherence to treatment. The main causes of death in people with epilepsy living in LMICs include those directly attributable to epilepsy, which yield a mean proportional mortality ratio (PMR) of 27.3% (range 5â75.5%) derived from population-based studies. These direct causes comprise status epilepticus, with reported PMRs ranging from 5 to 56.6%, and sudden unexpected death in epilepsy (SUDEP), with reported PMRs ranging from 1 to 18.9%. Important causes of mortality indirectly related to epilepsy include drowning, head injury, and burns. Epilepsy in LMICs has a significantly greater premature mortality, as in high-income countries, but in LMICs the excess mortality is more likely to be associated with causes attributable to lack of access to medical facilities such as status epilepticus, and preventable causes such as drowning, head injuries, and burns. This excess premature mortality could be substantially reduced with education about the risk of death and improved access to treatments, including AEDs
Common genetic variation near the phospholamban gene is associated with cardiac repolarisation: meta-analysis of three genome-wide association studies
To identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the TwinsUK and BRIGHT cohorts in the UK and the DCCT/EDIC cohort from North America. Five loci were significantly associated with QT interval at P<1×10<sup>−6</sup>. To validate these findings we performed an in silico comparison with data from two QT consortia: QTSCD (n = 15,842) and QTGEN (n = 13,685). Analysis confirmed the association between common variants near NOS1AP (P = 1.4×10<sup>−83</sup>) and the phospholamban (PLN) gene (P = 1.9×10<sup>−29</sup>). The most associated SNP near NOS1AP (rs12143842) explains 0.82% variance; the SNP near PLN (rs11153730) explains 0.74% variance of QT interval duration. We found no evidence for interaction between these two SNPs (P = 0.99). PLN is a key regulator of cardiac diastolic function and is involved in regulating intracellular calcium cycling, it has only recently been identified as a susceptibility locus for QT interval. These data offer further mechanistic insights into genetic influence on the QT interval which may predispose to life threatening arrhythmias and sudden cardiac death
Past and current asbestos exposure and future mesothelioma risks in Britain: The Inhaled Particles Study (TIPS)
BACKGROUND: Occupational and environmental airborne asbestos concentrations are too low and variable for lifetime exposures to be estimated reliably, and building workers and occupants may suffer higher exposure when asbestos in older buildings is disturbed or removed. Mesothelioma risks from current asbestos exposures are therefore not known. METHODS: We interviewed and measured asbestos levels in lung samples from 257 patients treated for pneumothorax and 262 with resected lung cancer, recruited in England and Wales. Average lung burdens in British birth cohorts from 1940 to 1992 were estimated for asbestos-exposed workers and the general population. RESULTS: Regression analysis of British mesothelioma death rates and average lung burdens in birth cohorts born before 1965 suggests a lifetime mesothelioma risk of approximately 0.01% per fibre/mg of amphiboles in the lung. In those born since 1965, the average lung burden is ∼1 fibre/mg among those with no occupational exposure. CONCLUSIONS: The average lifetime mesothelioma risk caused by recent environmental asbestos exposure in Britain will be about 1 in 10 000. The risk is an order of magnitude higher in a subgroup of exposed workers and probably in occupants in the most contaminated buildings. Further data are needed to discover whether asbestos still present in buildings, particularly schools, is a persistent or decreasing hazard to workers who disturb it and to the general population, and whether environmental exposure occurs predominantly in childhood or after beginning work. Similar studies are needed in other countries to estimate continuing environmental and occupational mesothelioma hazards worldwide, including the contribution from chrysotile
Prospective observational study of incidence and preventable burden of childhood tuberculosis, Kenya
Substantial progress has been made in the fight against tuberculosis (TB); however, new approaches are needed to achieve the current target set by the World Health Organization (WHO) to reduce TB incidence to 90% of 2016 levels by 2035 (1). A key element of WHO’s End TB Strategy is the prioritization of preventive treatment (2). However, the preventable burden of childhood TB has not been quantified in prospective epidemiologic studies, and globally, only an estimated 7% of eligible children received isoniazid chemoprophylaxis in 2015 (1).
Diagnosis of TB is more challenging in children than in adults (3). In low-resource settings, where TB burden is highest, diagnosis often relies on poorly validated clinical algorithms (4). As a result, adequate surveillance data are lacking, and published estimates of the global childhood TB burden vary widely (1,5–11). High-quality prospective data on the TB burden and case detection rate (CDR) in children are recognized priorities (8,11,12), and population-level data showing the preventable burden of childhood TB might reinforce the public health case for chemoprophylaxis in children. We designed the Kilifi Improving Diagnosis and Surveillance of Childhood TB (KIDS TB) Study to estimate the incidence, CDR, risk factors, and preventable burden of childhood TB in Kenya
An overview of ecological status, vulnerability and future perspectives of European large shallow, semi-enclosed coastal systems, lagoons and transitional waters
The paper gives an overview of some of the large, shallow, semi-enclosed coastal systems (SECS) in
Europe, These SECS are important both from the ecological and the economic perspective (socioecological
systems) and provide many valuable ecosystem goods and services.
Although some of the systems are transitional waters under theWater Framework Directive, this is not
the case for all of the systems. The paper adopts a Driver-Pressure-State-Impact-Response approach to
analyse the ecological status, vulnerability and future perspectives of these systems in the context of
global change.This work has been supported by: the EUROMEDLAG federation, http://www.euromedlag.eu/lagoonsfederation/; EC 5FP grant agreement 00084 (DITTY), http://www.ecolag.univ-montp2.
fr/index.php?option¼com_content&task¼view&lang¼en&id¼226; EC 6FP grant agreement 036992 (SPICOSA),www.spicosa.eu/; the LOICZ project, http://www.loicz.org/.info:eu-repo/semantics/publishedVersio
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