Prediction and sensitivity analysis of CNTs-modified asphalt’s adhesion force using a radial basis neural network model

The expected longer service life of modified asphalt can be jeopardized by different environmental factors, such as moisture, oxidation, etc. which affect the desired properties by altering the adhesive property. An insight into knowledge of the adhesive property of the asphalt can help in providing more durable asphalt pavement. The study attempted to develop different models of adhesive properties of polymers and carbon nanotubes (CNTs) modified asphalt binders. The polymer-CNT modified asphalt is processed to prepare different types of samples, by simulating the damage due to moisture and oxidization, following the corresponding standard method. An Atomic Force Microscopy (AFM) was employed to assess the nanoscale adhesion force of the tested samples following the existing functional group in asphalt. Finally, the study has developed Radial Basis Function Neural Network (RBFNN) as a function of different parameters including; asphalt chemistry (i.e. AFM tip type and constant), type and percentages of polymers and CNTs and different environmental exposures (oxidation, moisture, etc.) to predict the nano adhesion force of asphalt. It is observed that the adhesive property of the Styrene–Butadiene modified asphalt is more consistent compared to the Styrene–Butadiene–Styrene modified asphalt, while the presence of Single-Wall Nanotubes (SWNT) is observed to affect the adhesive properties of asphalt significantly as compared to Multi-Wall Nanotubes (MWNT). The higher accuracy level of RBFNN model also indicates that the functional group (tip-type) adding with the percentages and types of polymers and CNTs significantly affect the adhesive properties of asphalt

Global variation in the prevalence of suicidal ideation, anxiety and their correlates among adolescents: A population based study of 82 countries

Background: Suicidal ideation and anxiety are common among adolescents although their prevalence has predominantly been studied in high income countries. This study estimated the population prevalence of suicidal ideation and anxiety and their correlates with peer support, parent-adolescent relationship, peer victimization, conflict, isolation and loneliness across a range of low-income, lower-middle-income, upper-middle-income countries and high-income countries (LMIC–HICs). Methods: Data were drawn from the Global School-based Student Health Survey (GSHS) of adolescents aged 12–17 years between 2003 and 2015 in 82 LM-HICs from the six World Health Organization (WHO) regions. For those countries with repeated time point data in this study, we used data from the most recent survey. We estimated weighted prevalence of suicidal ideation and anxiety by country, region and at a global level with the following questions:-“Did you ever seriously consider attempting suicide during the past 12 months?” and “During the past 12 months, how often have you been so worried about something that you could not sleep at night?”. We used multiple binary logistic regression to estimate the adjusted association between adolescent age, sex, socioeconomic status, peer support, parent-adolescent relationship, peer victimization, conflict, isolation and loneliness with suicidal ideation and anxiety. Findings: The sample comprised of 275,057 adolescents aged 12–17 years (mean age was 14.6 (SD 1.18) years of whom 51.8% were females). The overall 12 months pooled prevalence of suicidal ideation and anxiety were 14.0% (95% CI 10.0–17.0%) and 9.0% (7.0–12.0%) respectively. The highest pooled prevalence of suicidal ideation was observed in the Africa Region (21.0%; 20.0–21.0%) and the lowest was in the Asia region (8.0%, 8.0–9.0%). For anxiety, the highest pooled prevalence was observed in Eastern Mediterranean Region (17.0%, 16.0–17.0%) the lowest was in the European Region (4.0%, 4.0–5.0%). Being female, older age, having a lower socioeconomic status and having no close friends were associated with a greater risk of suicidal ideation and anxiety. A higher levels of parental control was positively associated with a greater likelihood of experiencing suicidal ideation (OR: 1.65, 1.45–1.87) and anxiety (1.53, 1.30–1.80). Parental understanding and monitoring were negatively associated with mental health problems. Similarly, the odds of experiencing suicidal ideation and anxiety were higher among adolescents who had been experiencing peer conflict (1.36, 1.24–1.50; 1.54, 1.40–1.70), peer victimization (1.26, 1.15–1.38; 1.13, 1.02–1.26), peer isolation (1.69, 1.53–1.86; 1.76, 1.61–1.92) and reported loneliness (2.56, 2.33–2.82; 5.63, 5.21–6.08). Interpretations: Suicidal ideation and anxiety are prevalent among adolescents although there is significant global variation. Parental and peer supports are protective factors against suicidal ideation and anxiety. Peer based interventions to enhance social connectedness and parent skills training to improve parent-child relationships may reduce suicidal ideation and anxiety. Research to inform the factors that influence country and regional level differences in adolescent mental health problems may inform preventative strategies. Funding: Non

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000-17: analysis for the Global Burden of Disease Study 2017

Background: Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods: We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings: The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation: By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health. Funding: Bill & Melinda Gates Foundation

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000-17: analysis for the Global Burden of Disease Study 2017

Background: Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods: We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings: The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation: By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health. Funding: Bill & Melinda Gates Foundation