Stochastic macromodeling for hierarchical uncertainty quantification of nonlinear electronic systems

A hierarchical stochastic macromodeling approach is proposed for the efficient variability analysis of complex nonlinear electronic systems. A combination of the Transfer Function Trajectory and Polynomial Chaos methods is used to generate stochastic macromodels. In order to reduce the computational complexity of the model generation when the number of stochastic variables increases, a hierarchical system decomposition is used. Pertinent numerical results validate the proposed methodology

Globally Guided Trajectory Planning in Dynamic Environments

Navigating mobile robots through environments shared with humans is challenging. From the perspective of the robot, humans are dynamic obstacles that must be avoided. These obstacles make the collision-free space nonconvex, which leads to two distinct passing behaviors per obstacle (passing left or right). For local planners, such as receding-horizon trajectory optimization, each behavior presents a local optimum in which the planner can get stuck. This may result in slow or unsafe motion even when a better plan exists. In this work, we identify trajectories for multiple locally optimal driving behaviors, by considering their topology. This identification is made consistent over successive iterations by propagating the topology information. The most suitable high-level trajectory guides a local optimization-based planner, resulting in fast and safe motion plans. We validate the proposed planner on a mobile robot in simulation and real-world experiments.Comment: 7 pages, 6 figures, accepted to IEEE International Conference on Robotics and Automation (ICRA) 202

Premature subclinical atherosclerosis in children and young adults with juvenile idiopathic arthritis.:A review considering preventive measures

Many studies show that Juvenile Idiopathic Arthritis (JIA) is associated with early subclinical signs of atherosclerosis. Chronic inflammation per se may be an important driver but other known risk factors, such as dyslipidemia, hypertension, insulin insensitivity, a physically inactive lifestyle, obesity, and tobacco smoking may also contribute substantially. We performed a systematic review of studies through the last 20 years on early signs of subclinical atherosclerosis in children and adolescents with JIA with the purpose of investigating whether possible risk factors, other than inflammation, were considered. We found 13 descriptive cross sectional studies with healthy controls, one intervention study and two studies on adults diagnosed with JIA. Only one study addressed obesity, and physical activity (PA) has only been assessed in one study on adults with JIA and only by self-reporting. This is important as studies on PA in children with JIA have shown that most patients are less physically active than their healthy peers, and as physical inactivity in several large studies of normal schoolchildren is found to be associated with increased clustering of risk factors for cardiovascular disease. It is thus possible that an inactive lifestyle in patients with JIA is an important contributor to development of the subclinical signs of atherosclerosis seen in children with JIA, and that promotion of an active lifestyle in childhood and adolescence may diminish the risk for premature atherosclerotic events in adulthood

Treatment Intensification in Patients With Kawasaki Disease and Coronary Aneurysm at Diagnosis.

BackgroundCoronary artery aneurysms (CAA) are a serious complication of Kawasaki disease. Treatment with intravenous immunoglobulin (IVIg) within 10 days of fever onset reduces the risk of CAA from 25% to <5%. Corticosteroids and infliximab are often used in high-risk patients or those with CAA at diagnosis, but there are no data on their longer-term impact on CAA.MethodsRetrospective multicenter study including children who had CAA with a z score ≥2.5 and <10 at time of diagnosis and who received primary therapy with IVIg alone or in combination with either corticosteroids or infliximab within 10 days of onset of fever.ResultsOf 121 children, with a median age of 2.8 (range 0.1-15.5) years, 30 (25%) received primary therapy with corticosteroids and IVIg, 58 (48%) received primary therapy with infliximab and IVIg, and 33 (27%) received primary therapy with IVIg only. Median coronary z scores at the time of diagnosis did not differ among treatment groups (P = .39). Primary treatment intensification with either corticosteroids or infliximab were independent protective factors against progression of coronary size on follow-up (coefficient: -1.31 [95% confidence interval: -2.33 to -0.29]; coefficient: -1.07 [95% confidence interval: -1.95 to -0.19], respectively).ConclusionsAmong a high-risk group of patients with Kawasaki disease with CAA on baseline echocardiography, those treated with corticosteroids or infliximab in addition to IVIg had less progression in CAA size compared with those treated with IVIg alone. Prospective randomized trials are needed to determine the best adjunctive treatment of patients who present with CAA

Temporal Trends in Pulse Pressure and Mean Arterial Pressure During the Rise of Pediatric Obesity in US Children

Background: Somatic growth in childhood is accompanied by substantial remodeling of the aorta. Obesity is associated with increased aortic stiffness and flow and may interfere with aortic remodeling during growth. Wide pulse pressure (PP) indicates mismatch between aortic impedance and pulsatile flow and increases risk for future systolic hypertension and cardiovascular disease (CVD). We hypothesized that the rise of pediatric obesity would be associated with a temporal trend to higher PP. Methods and Results: We analyzed demographic, anthropometric, and blood pressure (BP) data for 8‐ to 17‐year‐old children (N=16 457) from the cross‐sectional National Health and Nutrition Examination Surveys (NHANES) for 1976 through 2008. Multivariable adjusted survey regression was used to examine temporal trends in PP and mean arterial pressure (MAP) and the relation to obesity. Across this period, unadjusted PP was higher (0.29 mm Hg/y, 95% CI 0.26 to 0.33 mm Hg/y; P<0.0001), while MAP was lower (−0.24 mm Hg/y, 95% CI −0.27 to −0.20 mm Hg/y; P<0.0001) across examinations. Adjusting for body mass index partially attenuated the temporal trend for PP by 32% (P<0.0001). Obesity amplified the relation between taller height and higher PP (from 0.23 [95% CI 0.19 to 0.28] to 0.27 [95% CI 0.21 to 0.34] mm Hg/cm height in boys and from 0.08 [95% CI 0.04 to 0.13] to 0.22 [95% CI 0.13 to 0.31] mm Hg/cm height in girls; P<0.01 for both). Conclusions: PP has increased during the rise of pediatric obesity. Higher PP may indicate mismatch between aortic diameter, wall stiffness, and flow in obese children during a period of rapid somatic growth when the aorta is already under considerable remodeling stress

Death, dying and informatics: misrepresenting religion on MedLine

BACKGROUND: The globalization of medical science carries for doctors worldwide a correlative duty to deepen their understanding of patients' cultural contexts and religious backgrounds, in order to satisfy each as a unique individual. To become better informed, practitioners may turn to MedLine, but it is unclear whether the information found there is an accurate representation of culture and religion. To test MedLine's representation of this field, we chose the topic of death and dying in the three major monotheistic religions. METHODS: We searched MedLine using PubMed in order to retrieve and thematically analyze full-length scholarly journal papers or case reports dealing with religious traditions and end-of-life care. Our search consisted of a string of words that included the most common denominations of the three religions, the standard heading terms used by the National Reference Center for Bioethics Literature (NRCBL), and the Medical Subject Headings (MeSH) used by the National Library of Medicine. Eligible articles were limited to English-language papers with an abstract. RESULTS: We found that while a bibliographic search in MedLine on this topic produced instant results and some valuable literature, the aggregate reflected a selection bias. American writers were over-represented given the global prevalence of these religious traditions. Denominationally affiliated authors predominated in representing the Christian traditions. The Islamic tradition was under-represented. CONCLUSION: MedLine's capability to identify the most current, reliable and accurate information about purely scientific topics should not be assumed to be the same case when considering the interface of religion, culture and end-of-life care

Associations of Blood Pressure and&nbsp;Cholesterol Levels During Young&nbsp;Adulthood With Later&nbsp;Cardiovascular Events.

BackgroundBlood pressure (BP) and cholesterol are major modifiable risk factors for cardiovascular disease (CVD), but effects of exposures during young adulthood on later life CVD risk have not been well quantified.ObjectiveThe authors sought to evaluate the independent associations between young adult exposures to risk factors and later life CVD risk, accounting for later life exposures.MethodsThe authors pooled data from 6 U.S. cohorts with observations spanning the life course from young adulthood to later life, and imputed risk factor trajectories for low-density lipoprotein (LDL) and high-density lipoprotein cholesterols, systolic and diastolic BP starting from age 18 years for every participant. Time-weighted average exposures to each risk factor during young (age 18 to 39 years) and later adulthood (age ≥40 years) were calculated and linked to subsequent risks of coronary heart disease (CHD), heart failure (HF), or stroke.ResultsA total of 36,030 participants were included. During a median follow-up of 17 years, there were 4,570 CHD, 5,119 HF, and 2,862 stroke events. When young and later adult risk factors were considered jointly in the model, young adult LDL&nbsp;≥100&nbsp;mg/dl (compared with&nbsp;&lt;100&nbsp;mg/dl) was associated with a 64% increased risk for CHD, independent of later adult exposures. Similarly, young adult SBP&nbsp;≥130&nbsp;mm&nbsp;Hg (compared with&nbsp;&lt;120&nbsp;mm&nbsp;Hg) was associated with a 37% increased risk for HF, and young adult DBP&nbsp;≥80&nbsp;mm&nbsp;Hg (compared with&nbsp;&lt;80&nbsp;mm&nbsp;Hg) was associated with a 21% increased risk.ConclusionsCumulative young adult exposures to elevated systolic BP, diastolic BP and LDL were associated with&nbsp;increased CVD risks in later life, independent of later adult exposures