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Limitations on Control System Performance

Abstract in Undetermined This paper deals with limitations on control system performance due to load disturbances, measurement noise, actuator saturation and system dynamics. Simple problems which capture the essence of the problem are formulated and solved. The results make it possible to quickly explore a design problem for preliminary assessment before attempting to do massive computations. TheThis paper deals with limitations on control system performance due to load disturbances, measurement noise, actuator saturation and system dynamics. Simple problems which capture the essence of the problem are formulated and solved. The results make it possible to quickly explore a design problem for preliminary assessment before attempting to do massive computations. They are also useful ingredi

"Color, Materiality, Sensory Experience and Late Bronze Age Burials in the Argolid"

One aspect of tombs and burials in the BA Aegean in general that has not received much notice is that of color (hue and shine). Were certain hues more predominant than others? Was this significant? Was the presence (or absence) of shine of importance? Following a discussion of ‘what is color?’, the study and results of the colors of the finds from Late Bronze Age tombs at three sites in the Greek

Linear Quadratic Control under Quadratic Constraints

The linear quadratic optimal control problem under quadratic constraints is an optimization problem over a generally non-convex set. Yakubovich [8] and Megretski [4] have studied this problem, and they show how it may be translated into a two-stage, convex optimization problem. In this paper we study the linear quadratic control problem under quadratic constraints for generalized first-order syste

Vegetation Observation in the Big Data Era : Sentinel-2 data for mapping the seasonality of land vegetation

Using satellite remote sensing data for observing vegetation seasonality is an important approach to estimate phenology and carbon uptake of land vegetation. The successful launch of Sentinel-2B in 2017 initiated full operation of the Sentinel-2 twin satellites, and they now provide 10 - 60 m spatial resolution satellite data at 5 days temporal resolution worldwide, releasing approximately 3.2 TB

Health-Related Quality of Life in Children and Young Adults with Marfan Syndrome

OBJECTIVE: To assess health-related quality of life (HRQOL) in a large multicenter cohort of children and young adults with Marfan syndrome participating in the Pediatric Heart Network Marfan Trial.STUDY DESIGN: The Pediatric Quality of Life Inventory (PedsQL) 4.0 Generic Core Scales were administered to 321 subjects with Marfan syndrome (5-25 years). PedsQL scores were compared with healthy popul

Predictors of Rapid Aortic Root Dilation and Referral for Aortic Surgery in Marfan Syndrome

Few data exist regarding predictors of rapid aortic root dilation and referral for aortic surgery in Marfan syndrome (MFS). To identify independent predictors of the rate of aortic root (AoR) dilation and referral for aortic surgery, we investigated the data from the Pediatric Heart Network randomized trial of atenolol versus losartan in young patients with MFS. Data were analyzed from the echocar

Comparison of valvar and right ventricular function following transcatheter and surgical pulmonary valve replacement

OBJECTIVE: Trans-catheter (TC) pulmonary valve replacement (PVR) has become common practice for patients with right ventricular outflow tract obstruction (RVOTO) and/or pulmonic insufficiency (PI). Our aim was to compare PVR and right ventricular (RV) function of patients who received TC vs surgical PVR.DESIGN: Retrospective review of echocardiograms obtained at three time points: before, immediat

Biochemical Screening for Pulmonary Hypertension in Preterm Infants with Bronchopulmonary Dysplasia

BACKGROUND: Pulmonary hypertension (PH) in infants with bronchopulmonary dysplasia (BPD) is associated with increased morbidity and mortality. Elevated levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and decreased levels of amino acid precursors of nitric oxide (NO) have been associated with PH, but have not been studied in infants with PH secondary to BPD.OBJECTIVE: The aim of thi

Three-Dimensional Evaluation of Aortic Valve Annular Shape in Children With Bicuspid Aortic Valves and/or Aortic Coarctation Compared With Controls

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality, occurring in 1% to 2% of the general population. Adults with degenerative aortic valve (AV) disease have been shown to have an elliptical shaped AV annulus. The goal of this study was to investigate the shape of the aortic annulus in children with BAV, coarctation of the aorta (CoA) with or without BAV, and normal contr

Aortic stiffness and left ventricular diastolic function in children with well-functioning bicuspid aortic valves

AIMS: Aortic stiffness and diastolic function are abnormal in adults with bicuspid aortic valves (BAVs). The goal of this study was to determine the relationship between aortic stiffness and left ventricular (LV) diastolic impairment in children with well-functioning BAV and no associated congenital heart disease.METHODS AND RESULTS: This is a retrospective review of echocardiograms in children wi

Left Ventricular End-Systolic Eccentricity Index for Assessment of Pulmonary Hypertension in Infants

BACKGROUND: Pulmonary hypertension (PH) is a common problem in the neonatal intensive care unit and is associated with significant morbidity and mortality. The aim of this study was to identify a quantitative echocardiographic marker of septal curvature that can be used to accurately identify PH in NICU infants with concern for PH.METHODS: Echocardiograms of infants who were prematurely born and i

Prevalence of post-thrombotic syndrome after cardiac catheterization

BACKGROUND: As the survival of children with cardiac disease increases, chronic complications of deep venous thrombosis from cardiac catheterization, particularly post-thrombotic syndrome, may be important to monitor for and treat, if needed. We aimed to determine the prevalence of this syndrome in children who underwent cardiac catheterization.PROCEDURE: We conducted a cross-sectional study of ch

Atenolol versus losartan in children and young adults with Marfan's syndrome

BACKGROUND: Aortic-root dissection is the leading cause of death in Marfan's syndrome. Studies suggest that with regard to slowing aortic-root enlargement, losartan may be more effective than beta-blockers, the current standard therapy in most centers.METHODS: We conducted a randomized trial comparing losartan with atenolol in children and young adults with Marfan's syndrome. The primary outcome w

Association between right ventricular dysfunction and restrictive lung disease in childhood cancer survivors as measured by quantitative echocardiography

BACKGROUND: Restrictive lung disease is a complication in childhood cancer survivors who received lung-toxic chemotherapy and/or thoracic radiation. Left ventricular dysfunction is documented in these survivors, but less is known about right ventricular (RV) function. Quantitative echocardiography may help detect subclinical RV dysfunction. The aim of this study was to assess RV function quantitat

Normal pediatric data for isovolumic acceleration at the lateral tricuspid valve annulus-a heart rate - dependent measure of right ventricular contractility

BACKGROUND: Quantitative assessment of right ventricular (RV) function is important for the management of patients with congenital heart disease. Tissue Doppler (TDI)-derived myocardial acceleration during isovolumic contraction (IVA) is an echocardiographic measure of contractility that is independent of loading conditions. The aim of this study was to establish normative data for IVA at the late

Letter to the Editor in response to "publication performance of women compared to men in German cardiology" by Boehm et al. (2014)

Based on their review of abstracts submitted to the German Cardiac Society, Boehm et al. (2014) report better success of female vs male cardiologists publishing in journals with an impact factor ≥5. However, only 25% of conference abstracts were submitted by women, perhaps suggesting a paucity of women in academic cardiology. In this 'letter to the editor' we review gender statistics in the medica

Characteristics of children and young adults with Marfan syndrome and aortic root dilation in a randomized trial comparing atenolol and losartan therapy

BACKGROUND: The Pediatric Heart Network designed a clinical trial to compare aortic root growth and other short-term cardiovascular outcomes in children and young adults with Marfan syndrome randomized to receive atenolol or losartan. We report here the characteristics of the screened population and enrolled subjects.METHODS AND RESULTS: Between 2007 and 2011, 21 clinical sites randomized 608 subj