PDFS: Practical Data Feed Service for Smart Contracts

Smart contracts are a new paradigm that emerged with the rise of the blockchain technology. They allow untrusting parties to arrange agreements. These agreements are encoded as a programming language code and deployed on a blockchain platform, where all participants execute them and maintain their state. Smart contracts are promising since they are automated and decentralized, thus limiting the involvement of third trusted parties, and can contain monetary transfers. Due to these features, many people believe that smart contracts will revolutionize the way we think of distributed applications, information sharing, financial services, and infrastructures. To release the potential of smart contracts, it is necessary to connect the contracts with the outside world, such that they can understand and use information from other infrastructures. For instance, smart contracts would greatly benefit when they have access to web content. However, there are many challenges associated with realizing such a system, and despite the existence of many proposals, no solution is secure, provides easily-parsable data, introduces small overheads, and is easy to deploy. In this paper we propose PDFS, a practical system for data feeds that combines the advantages of the previous schemes and introduces new functionalities. PDFS extends content providers by including new features for data transparency and consistency validations. This combination provides multiple benefits like content which is easy to parse and efficient authenticity verification without breaking natural trust chains. PDFS keeps content providers auditable, mitigates their malicious activities (like data modification or censorship), and allows them to create a new business model. We show how PDFS is integrated with existing web services, report on a PDFS implementation and present results from conducted case studies and experiments.Comment: Blockchain; Smart Contracts; Data Authentication; Ethereu

Carotid artery intima-media thickness and hypertensive heart disease: a short review

Sustained by its relative ease of assessment, carotid artery intima-media thickness (cIMT) has emerged as an important surrogate marker of target organ damage in hypertensive heart disease over the last three decades. However, the prognostic utility of cIMT in hypertensive heart disease differs depending on its application. This review outlines cIMT and its prognostic utility among patients with hypertensive heart disease. It provides an overview of limitations of cIMT and areas for future research.</p

Utility of Three Adiposity Indices for Identifying Left Ventricular Hypertrophy and Geometric Remodeling in Chinese Children

Background: Previous studies have shown that waist-to-height ratio (WHtR) performed similarly well when compared to body mass index (BMI) and waist circumference (WC) for identifying cardiovascular risk factors. However, to our knowledge, the performance of these three adiposity indices for identifying left ventricular hypertrophy (LVH) and left ventricular geometric (LVG) remodeling in youth has not been assessed. We aimed to determine the utility of BMI, WC and WHtR for identifying LVH and LVG in Chinese children.Methods: This study included 1,492 Chinese children aged 6-11 years. Adiposity indices assessed were BMI, WC and WHtR. LVH and high relative wall thickness (RWT) were defined using sex- and age-specific 90th percentile values of left ventricular mass index and RWT, respectively, based on the current population. LVG remodeling included concentric remodeling (CR), eccentric hypertrophy (EH) and concentric hypertrophy (CH), which was defined based on the combination of LVH and high RWT.Results: The magnitude of association of central obesity defined by WHtR with LVH [odds ratio (OR) =10.09, 95% confidence interval (CI) =6.66-15.29] was similar with general obesity defined by BMI (OR=10.49, 95% CI=6.97-15.80), and both were higher than central obesity defined by WC (OR=6.87, 95% CI=4.57-10.33). Compared with BMI, WHtR had better or similar predictive utility for identifying LVH, EH, and CH [the area under the curve (AUC): 0.84 vs. 0.79; 0.84 vs. 0.77; 0.87 vs. 0.88, respectively]; WC had worse or similar discriminatory utility with AUCs of 0.73, 0.70, 0.83, respectively.Conclusion: WHtR performed similarly or better than BMI or WC for identifying LVH and LVG remodeling among Chinese children. WHtR provides a simple and convenient measure of central obesity that might improve the discrimination of children with cardiac structural damage.</p

Tracking of secretory phospholipase A2 enzyme activity levels from childhood to adulthood: a 21-year cohort.

OBJECTIVE: Secretory phospholipase A2 (sPLA2) enzyme activity is a potential inflammatory biomarker for cardiovascular disease. We examined the tracking, or persistence, of sPLA2 enzyme activity levels from childhood to adulthood, and identify potentially modifiable factors affecting tracking. METHOD: Prospective cohort of 1735 children (45% females) who had serum sPLA2 enzyme activity levels and other cardiovascular disease risk factors measured in 1980 that were followed-up in 2001. RESULTS: sPLA2 activity tracked from childhood to adulthood for males (r=0.39) and females (r=0.45). Those who decreased body mass index relative to their peers were more likely to resolve elevated childhood sPLA2 levels than have persistent elevated sPLA2 levels in childhood and adulthood. Those who consumed less fruit, and gained more body mass index relative to their peers, began smoking or were a persistent smoker between childhood and adulthood were more likely to develop incident elevated sPLA2 levels than those with persistent not elevated sPLA2 levels. CONCLUSIONS: Childhood sPLA2 enzyme activity levels associate with adult sPLA2 levels 21 years later. Healthful changes in modifiable risk factors that occur between childhood and adulthood might prevent children from developing elevated sPLA2 levels in adulthood

Recommended physical activity and all cause and cause specific mortality in US adults: prospective cohort study

OBJECTIVE: To determine the association between recommended physical activity according to the 2018 physical activity guidelines for Americans and all cause and cause specific mortality using a nationally representative sample of US adults.DESIGN: Population based cohort study.SETTING: National Health Interview Survey (1997-2014) with linkage to the National Death Index records to 31 December 2015.PARTICIPANTS: 479 856 adults aged 18 years or older.EXPOSURES: Participant self-reports of the amount of leisure time spent in aerobic physical activity and muscle strengthening activity each week were combined and categorised into four groups: insufficient activity, aerobic activity only, muscle strengthening only, and both aerobic and muscle strengthening activities according to the physical activity guidelines.MAIN OUTCOME MEASURES: All cause mortality and cause specific mortality (cardiovascular disease, cancer, chronic lower respiratory tract diseases, accidents and injuries, Alzheimer's disease, diabetes mellitus, influenza and pneumonia, and nephritis, nephrotic syndrome, or nephrosis) obtained from the National Death Index records.RESULTS: During a median follow-up of 8.75 years, 59 819 adults died from all causes, 13 509 from cardiovascular disease, 14 375 from cancer, 3188 from chronic lower respiratory tract diseases, 2477 from accidents and injuries, 1470 from Alzheimer's disease, 1803 from diabetes mellitus, 1135 from influenza and pneumonia, and 1129 from nephritis, nephrotic syndrome, or nephrosis. Compared with those who did not meet the physical activity guidelines (n=268 193), those who engaged in recommended muscle strengthening activity (n=21 428; hazard ratio 0.89, 95% confidence interval 0.85 to 0.94) or aerobic activity (n=113 851; 0.71, 0.69 to 0.72) were found to be at reduced risk of all cause mortality; and even larger survival benefits were found in those engaged in both activities (n=76 384; 0.60, 0.57 to 0.62). In addition, similar patterns were reported for cause specific mortality from cardiovascular disease, cancer, and chronic lower respiratory tract diseases.CONCLUSIONS: Adults who engage in leisure time aerobic and muscle strengthening activities at levels recommended by the 2018 physical activity guidelines for Americans show greatly reduced risk of all cause and cause specific mortality. These data suggest that the physical activity levels recommended in the guidelines are associated with important survival benefits.</div

Two-Year Change in Blood Pressure Status and Left Ventricular Mass Index in Chinese Children

Background: Elevated blood pressure (BP) is associated with target organ damage, such as left ventricular hypertrophy (LVH), in childhood. However, it is unclear if children who resolve elevated BP have reduced levels of left ventricular mass index (LVMI). This study aimed to examine the association between change in BP status over 2 years and LVMI among Chinese children. Methods: Data were from 1,183 children aged 6-11 years at baseline in 2017 who were followed up in 2019 in the Huantai Childhood Cardiovascular Health Cohort Study. Change in BP status over 2 years from baseline to follow-up was categorized as: persistent normal BP, resolved elevated BP (elevated BP at baseline, normal BP at follow-up), incident elevated BP (normal BP at baseline, elevated BP at follow-up), and persistent elevated BP. Elevated BP status was defined according to national reference standards as systolic or diastolic BP levels >= sex-, age-, and height-specific 95th percentiles. Results: LVMI levels were lowest in children with persistent normal BP (30.13 g/m(2.7)), higher in those with incident elevated BP (31.27 g/m(2.7)), and highest in those with persistent elevated BP (33.26 g/m(2.7)). However, LVMI levels in those who had resolved elevated BP (30.67 g/m(2.7)) were similar to those with persistent normal BP. In the fully adjusted model, compared with children with persistent normal BP, those with persistent elevated BP and incident elevated BP had higher LVMI at follow-up (ss = 3.131, p Conclusion: Developing or maintaining elevated BP over a 2-year period in childhood associated with higher levels of LVMI, but those able to resolve their elevated BP status over the same period had LVMI levels that were similar with those who had normal BP at both time points. Thus, it is important to identify children with elevated BP at early time and to take effective measures to lower their BP levels, thereby reducing high LVMI levels and related cardiovascular diseases in the future.</p

Prevalence and changes of anemia among young children and women in 47 low- and middle-income countries, 2000-2018

BackgroundAnemia remains a major public health issue, particularly for children and women in low- and middle-income countries (LMICs). However, the current prevalence and recent changes of anemia among young children and women of reproductive age, particularly for pregnant women in different trimesters are unclear. We examined the current prevalence of anemia among children aged less than 5 years by age (6-35 months vs. 36-59 months) and women of reproductive age by pregnant status (pregnant vs. non-pregnant) and trimesters (the third vs. the second vs. the first trimester) between 2010 and 2018 and further examined changes in the prevalence from 2000-2009 to 2010-2018.MethodsData were from the cross-sectional Demographic and Health Surveys performed between 2000 and 2018. A total of 47 countries were included to examine the current prevalence of anemia (weighted prevalence and 95% confidence interval [CI]) among young children aged less than 5 years (N = 459,785) and 46 countries among women of reproductive age (N = 1,079,805) between 2010 and 2018. To examine changes in the prevalence of anemia, a total of 29 countries with at least two Demographic and Health Surveys performed between 2000 and 2009 (children: N = 130,772; women: N = 371,845) and 2010-2018 (children: N = 386,202; women: N = 928,889) were included. Modified Poisson regression analyses with robust error variance were used to examine changes in anemia between 2000-2009 and 2010-2018 in participants by child age (6-5 months vs. 36-59 months), women pregnant status (pregnant vs. non-pregnant), trimesters (the second or third trimester vs. the first trimester) with the adjustment for potential covariates.FindingsIn 47 LMICs for children aged less than 5 years between 2010 and 2018, the total prevalence of anemia was 56.5% (95% CI 56.2, 56.8). Younger children aged 6-35 months were more likely to have anemia than older children aged 36-59 months (adjusted odds ratio [OR] 1.38, 95% CI 1.36-1.39, P InterpretationThe prevalence of anemia among children aged less than 5 years and women of reproductive age was still high in LMICs, particularly for younger children and pregnant women. The relative change among women of reproductive age was far away from the WHO goal of reduction of anemia by 50% by 2025 (i.e., prevalence reduction to about 15.2% by 2025 from 30.3% at 2012 baseline). Continued and effective efforts, particularly for high-risk populations, are needed to improve the general health of the population.</p

Global prevalence of WHO infant feeding practices in 57 LMICs in 2010-2018 and time trends since 2000 for 44 LMICs

BackgroundThe World Health Assembly set a global target of increasing exclusive breastfeeding for infants under 6 months to at least 50% by year 2025. However, little is known about the current status of breastfeeding practice, as well as the trends in breastfeeding practices during recent years. We examined global prevalence of the World Health Organization (WHO) feeding practices in 57 low- and middle-income countries (LMICs) and time trends since 2000 for 44 selected countries.MethodsWe included 57 eligible LMICs that had completed data on breastfeeding and complementary feeding in 2010–2018 from the Demographic and Health Surveys (DHS) for examining current feeding status. We further selected 44 LMICs that had two standard DHS surveys between 2000 and 2009 and 2010–2018 to examine time trends of feeding status. We calculated global, regional, and national weighted prevalence estimates and 95% confidence intervals (CIs) for five breastfeeding indicators and two complementary feeding indicators.FindingsIn 57 LMICs during 2010–2018, global weighted prevalence was 51.9% for early initiation of breastfeeding, 45.7% for exclusive breastfeeding under 6 months, 32.0% for exclusive breastfeeding at 4–5 months, 83.1% for continued breastfeeding at 1 year, 56.2% for continued breastfeeding at 2 years, 14.9% for introduction of solid, semi-solid or soft foods under 6 months, and 63.1% for introduction of solid, semi-solid or soft foods at 6–8 months. Eastern Mediterranean (34.5%) and European regions (43.7%) (vs. South-East Asia/Western Pacific (55.2%)), and upper middle-income countries (38.4%) (vs. lower middle-income countries (47.4%)) had poorer performance of exclusive breastfeeding under 6 months. South-East Asia/Western Pacific regions (51.0%) (vs. other regions (68.3%-84.1%)) and low-income (66.4%) or lower middle-income countries (58.2%) (vs. upper middle-income countries (81.7%)) had lower prevalence of introduction of solid, semi-solid or soft foods at 6–8 months. In 44 selected LMICs from 2000 to 2009 to 2010–2018, total weighted prevalence presented an increase of 10.1% for exclusive breastfeeding under 6 months, but a 1.7% decrease for continued breastfeeding at 1 year. Over this period, the Eastern Mediterranean region had a 5.3% decrease of exclusive breastfeeding under 6 months, and the European region had a 2.0% increase for introduction of solid, semi-solid or soft foods under 6 months. The prevalence of introduction of solid, semi-solid or soft foods at 6–8 months decreased in South-East Asia/Western Pacific region by 15.2%, and in lower middle-income countries by 24.4%.InterpretationBreastfeeding practices in LMICs have continued to improve in the past decade globally, but practices still lag behind the WHO feeding recommendations. Breastfeeding practices differed greatly across WHO regions, with the Eastern Mediterranean and European regions, and upper middle-income countries facing the greatest challenges in meeting targets. Continued efforts are needed to achieve the 2025 global breastfeeding target.</p

Utility of blood pressure measurements at an initial screening visit to identify Chinese children and adolescents with hypertension

The performance of different BP readings and their combinations at a visit to identify children and adolescents with pediatric hypertension remains controversial. We aimed to assess the utility of different blood pressure (BP) readings and their combinations obtained at the initial screening visit for identifying Chinese children and adolescents with hypertension. Participants were 7831 children and adolescents aged 6-17 years measured as part of a cross-sectional survey conducted in Jinan, China between September 2012 and November 2014. BP was measured three times at up to three visits. Elevated BP at the initial visit was defined as systolic BP and/or diastolic BP >= age- and sex-specific 95th percentiles using the Chinese BP references for children and adolescents based on different BP readings and their combinations. Participants with elevated BP using (BP2+BP3)/2 across three visits were defined as having hypertension. Of the different readings or combinations examined, the mean of the last two readings at the initial visit had the best predictive utility for children and adolescents with hypertension (sensitivity: 100.0%; specificity: 86.9%; positive predictive value: 27.6%; negative predictive value: 100.0%). This was also reflected in the area under the curve being highest for the mean of the last two readings (0.93, 95% confidence interval: 0.93-0.94) compared with any of the other readings or combinations (BP1, BP2, BP3, [BP1+BP2]/2, [BP1+BP3]/2, and [BP1+BP2+BP3]/3; all p < .001). Taking three measurements of BP and using the average of the last two readings at a screening visit may be optimal for the identification of hypertension in youth