361 research outputs found
Surrogate-based optimization of tidal turbine arrays: a case study for the Faro-Olhão inlet
This paper presents a study for estimating the size of a tidal turbine array for the Faro-Olhão Inlet (Potugal) using a surrogate optimization approach. The method compromises problem formulation, hydro-morphodynamic modelling, surrogate construction and validation, and constraint optimization. A total of 26 surrogates were built using linear RBFs as a function of two design variables: number of rows in the array and Tidal Energy Converters (TECs) per row. Surrogates describe array performance and environmental effects associated with hydrodynamic and morphological aspects of the multi inlet lagoon. After validation, surrogate models were used to formulate a constraint optimization model. Results evidence that the largest array size that satisfies performance and environmental constraints is made of 3 rows and 10 TECs per row.Eduardo González-Gorbeña has received funding for the OpTiCA project (http://msca-optica.eu/) from the Marie Skłodowska-Curie Actions of the European Union's H2020-MSCA-IF-EF-RI-2016 / GA#: 748747. The paper is a contribution to the SCORE pro-ject, funded by the Portuguese Foundation for Science and Technology (FCT–PTDC/AAG-TEC/1710/2014). André Pacheco was supported by the Portuguese Foun-dation for Science and Technology under the Portuguese Researchers’ Programme 2014 entitled “Exploring new concepts for extracting energy from tides” (IF/00286/2014/CP1234).info:eu-repo/semantics/publishedVersio
Gastrointestinal helminthiasis presenting with acute diarrhoea and constipation: report of two cases with a second pathology.
Gastrointestinal helminthiasis in developing countries contributes to malnutrition and anemia. Diagnosis and treatment of helminthiasis, especially with low worm load is an unmet public health need in such settings. The infection may sometimes become manifest when a second pathology leads to purgation of the gastrointestinal tract. Two cases of helminthiasis are presented in which the infections only became amenable to diagnosis due to acute diarrhoea caused by giardiasis and lactulose administration. In the first case, acute giardiasis revealed Ascaris lumbricoides infestation, and in the second case primary helminthiasis (strongyloidiasis) was revealed by lactulose, and also led to Vibrio cholera bacteremia. These cases highlight the need to diagnose helminth infestations especially with low worm burdens by means of public health surveillance programmes. These cases highlight the need to diagnose helminth infestations especially with low worm burdens by means of public health surveillance programmes
The Impact of Heatwaves on Community Morbidity and Healthcare Usage: A Retrospective Observational Study Using Real-Time Syndromic Surveillance.
We investigated the impact of a moderate heatwave on a range of presenting morbidities in England. Asthma, difficulty breathing, cerebrovascular accident, and cardiovascular symptoms were analysed using general practitioner in hours (GPIH), out of hours (GPOOH) and emergency department (ED) syndromic surveillance systems. Data were stratified by age group and compared between a heatwave year (2013) and non-heatwave years (2012, 2014). Incidence rate ratios were calculated to estimate the differential impact of heatwave compared to non-heatwave summers: there were no apparent differences for the morbidities tested between the 2013 heatwave and non-heatwave years. A subset of GPIH data were used to study individuals at higher risk from heatwaves based on their pre-existing disease. Higher risk patients were not more likely to present at GPs or ED than other individuals. Comparing GPIH consultations and ED attendances for myocardial infarction/ischaemia (MI), there was evidence of a fall in the presentation of MI during the heatwave, which was particularly noted in the 65-74 years age group (and over 75 years in ED attendances). These results indicate the difficulty in identifying individuals at risk from non-fatal health effects of heatwaves and hot weather
The effect of two grading systems on the performance of medical students during oral examinations
Diagnostic methods to determine microbiology of postpartum endometritis in South Asia: laboratory methods protocol used in the Postpartum Sepsis Study: A prospective cohort study
Background: The South Asian region has the second highest risk of maternal death in the world. To prevent maternal deaths due to sepsis and to decrease the maternal mortality ratio as per the World Health Organization Millenium Development Goals, a better understanding of the etiology of endometritis and related sepsis is required. We describe microbiological laboratory methods used in the maternal Postpartum Sepsis Study, which was conducted in Bangladesh and Pakistan, two populous countries in South Asia.Methods/Design: Postpartum maternal fever in the community was evaluated by a physician and blood and urine were collected for routine analysis and culture. If endometritis was suspected, an endometrial brush sample was collected in the hospital for aerobic and anaerobic culture and molecular detection of bacterial etiologic agents (previously identified and/or plausible).Discussion: The results emanating from this study will provide microbiologic evidence of the etiology and susceptibility pattern of agents recovered from patients with postpartum fever in South Asia, data critical for the development of evidence-based algorithms for management of postpartum fever in the region
Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city.
Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen 'alert' levels, 'very high' days (vs. 'low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with 'high' versus 'low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures
State-of-the-art of design and operation of power systems with large amounts of wind power, summary of IEA Wind collaboration
An international forum for exchange of knowledge of power system impacts of wind power has been formed under the IEA Implementing Agreement on Wind Energy. The task “Design and Operation of Power Systems with Large Amounts of Wind Power” is analysing existing case studies from different power systems.There are a multitude of studies made and ongoing related to cost of wind integration. However, the results are not easy to compare. This paper summarises the results from 15 case studies
Heat protection behaviour in the UK: Results of an online survey after the 2013 heatwave
Background: The Heatwave Plan for England provides guidance for personal and home protection measures during heatwaves. Although studies in the USA, Australia and Europe have surveyed heat-related behaviours during heatwaves, few have been conducted in the UK. This study assesses personal and housing (at-home) behaviour and housing characteristics of the UK population during the 2013 heatwave. Methods: This paper analyses data from 1497 respondents of an online survey on heat protection measures and behaviour. Participants were asked questions about their behaviour during the 2013 heatwave, the characteristics of their current housing as well as about any negative health outcomes experienced due to the hot weather. We used multinomial logit regression to analyse personal and home heat protection behaviour and logistic regression to analyse characteristics of participants' current home (installed air conditioner, curtains etc.). We stratified the outcomes by age, sex, ethnicity, income, education and regional location. Results: In 2013, for all heat-related illness (except tiredness), a higher proportion of those in the younger age groups reported symptoms compared with those in the older age groups. Women, higher income groups and those with higher education levels were found to be more likely to report always/often taking personal heat protective measures. The elderly were less likely to take some personal and home protective measures but were more likely to live in insulated homes and open windows at night to keep their home cool. Conclusion: Our study has found a high level of awareness of the actions to take during heatwaves in the UK, and has identified important demographic indicators of sections of the UK population that might benefit from additional or more targeted information. The health agencies should attempt to provide better information about heatwaves to those vulnerable (elderly, those at risk living in London, low income earners) or identify any barriers that might be preventing them from undertaking protective behaviour
Readiness for antimicrobial resistance (AMR) surveillance in Pakistan; a model for laboratory strengthening
Background: Limited capacity of laboratories for antimicrobial susceptibility testing (AST) presents a critical diagnostic bottleneck in resource limited countries. This paper aims to identify such gaps and to explore whether laboratory networks could contribute towards improving AST in low resource settings. Methods: A self-assessment tool to assess antimicrobial susceptibility testing capacity was administered as a pre-workshop activity to participants from 30 microbiology laboratories in 3 cities in Pakistan. Data from public and private laboratories was analyzed and capacity of each scored in percentage terms. Laboratories from Karachi were invited to join a support network. A cohort of five laboratories that consented were provided additional training and updates sessions over a period of 15 months. Impact of training activities in these laboratories was evaluated using a point scoring (0-11) tool. Results: Results of self-assessment component identified a number of areas that required strengthening (scores of ≤60%). These included; readiness for AMR surveillance; 38 and 46%, quality assurance; 49 and 55%, and detection of specific organisms; 56 and 60% for public and private laboratories respectively. No significant difference was detected in AST capacity between public and private laboratories [ANOVA; p \u3e 0.05]. Scoring tool used to assess impact of training within the longitudinal cohort showed an increase from a baseline of 1-5.5 (August 2015) to improved post training scores of 7-11 (October 2016) for the 5 laboratories included. Moreover, statistical analysis using paired t-Test Analysis, assuming unequal variance, indicated that the increase in scored noted represents a statistically significant improvement in the components evaluated [p \u3c 0.05]. Conclusion: Strengthening of laboratory capacity for AMR surveillance is important. Our data shows that close mentoring and support can help enhance capacity for antimicrobial sensitivity testing in resource limited settings. Our study further presents a model wherein laboratory networks can be successfully established and used towards improving diagnostic capacity in such setting
Global distribution of invasive serotype 35D streptococcus pneumoniae isolates following introduction of 13-valent pneumococcal conjugate vaccine
A newly recognized pneumococcal serotype 35D, which differs from the 35B polysaccharide in structure and serology by not binding to factor serum 35a, was recently reported. The genetic basis for this distinctive serology is due to the presence of an inactivating mutation in wciG, which encodes an O-acetyltransferase responsible for O-acetylation of a galactofuranose. Here, we assessed the genomic data of a worldwide pneumococcal collection to identify serotype 35D isolates and understand their geographical distribution, genetic background and invasiveness potential. Of 21,980 pneumococcal isolates, 444 were originally typed as serotype 35B by PneumoCaT. Analysis of wciGrevealed 23 isolates from carriage (n=4) and disease (n=19) with partial or complete loss-of-funtion mutations, including mutations resulting in pre-mature stop codons (n=22) and an in-frame mutation (n=1). These were selected for further analysis. The putative 35D isolates were geographically widespread and 65.2% (15/23) of them was recovered after PCV13 introduction. Compared with serotype 35B, putative serotype 35D isolates have higher invasive disease potentials based on odds ratio (OR) (11.58; 95% CI, 1.42-94.19 vs 0.61; 95% CI, 0.40-0.92) and a higher prevalence of macrolide resistance mediated by mefA (26.1% vs 7.6%, p=0.009). Using Quellung, 50% (10/20) of viable isolates were serotype 35D, 25% (5/20) serotype 35B, and 25% (5/20) a mixture of 35B/35D. The discrepancy between phenotype and genotype requires further investigation. These findings illustrated a global distribution of an invasive serotype 35D among young children post-PCV13 introduction and underlined the invasive potential conferred by the loss of O-acetylation in the pneumococcal capsule
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