9 research outputs found

    Growth Rates Preservation (GRP) temporal benchmarking: Drawbacks and alternative solutions

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    Benchmarking monthly or quarterly series to annual data is a common practice in many National Statistical Institutes. The benchmarking problem arises when time series data for the same target variable are measured at different frequencies and there is a need to remove discrepancies between the sums of the sub-annual values and their annual benchmarks. Several benchmarking methods are available in the literature. The Growth Rates Preservation (GRP) benchmarking procedure is often considered the best method. It is often claimed that this procedure is grounded on an ideal movement preservation principle. However, we show that there are important drawbacks to GRP, relevant for practical applications, that are unknown in the literature. Alternative benchmarking models will be considered that do not suffer from some of GRP\u2019s side effects

    Semi-Oriented Bootstrap Percolation in Three Dimensions

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    this paper we give a partial answer to this question for a three dimensional semi-oriented BP model. The occurrence of such large occupied clusters in the random initial configuration is in general very improbable. The consequence of this is that it may take a very long time for the system to reach a fully occupied state, if it does so at all. This behaviour of BP models and especially the terms used to interpret this behaviour are reminiscent of metastability phenomena in the vicinity of first order phase transitions. Since bootstrap percolation models are relatively simple, the process in which the system leaves its initial metastable state and relaxes to its final state can be followed precisely. BP models are therefore particularly interesting for physicists. Analogies between BP models and physically more realistic models have been pointed out in, among others, Aizenman and Lebowitz (1988) and Dehghanpour and Schonmann (1996a, 1996b). The name bootstrap percolation was apparently first mentioned by Chalup

    Solving Large Data Consistency Problems at Statistics Netherlands Using Macro Integration Techniques

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    Parallel Sessions E: Advances in Integration of Large System Economic Data: Theory and Practic

    Nonlinear mixed effects modeling of the diurnal blood pressure profile in a multiracial population

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    Cardiac and cerebrovascular events in hypertensive patients are related to specific features of the 24-hour diurnal blood pressure (BP) profile (i.e., daytime and nighttime BP, nocturnal dip (ND), and morning surge (MS)). This investigation aimed to characterize 24-hour diurnal systolic BP (SBP) with parameters that correlate directly with daytime and nighttime SBP, ND, and MS using nonlinear mixed effects modeling. Ambulatory 24-hour SBP measurements (ABPM) of 196 nontreated subjects from three ethnic groups were available. A population model was parameterized in NONMEM to estimate and evaluate the parameters baseline SBP (BSL), nadir (minimum SBP during the night), and change (SBP difference between day and night). Associations were tested between these parameters and patient-related factors to explain interindividual variability. The diurnal SBP profile was adequately described as the sum of 2 cosine functions. The following typical values (interindividual variability) were found: BSL = 139 mm Hg (11%); nadir = 122 mm Hg (14%); change = 25 mm Hg (52%), and residual error = 12 mm Hg. The model parameters correlate well with daytime and nighttime SBP, ND, and MS (R (2) = 0.50-0.92). During covariate analysis, ethnicity was found to be associated with change; change was 40% higher in white Dutch subjects and 26.8% higher in South Asians than in blacks. The developed population model allows simultaneous estimation of BSL, nadir, and change for all individuals in the investigated population, regardless of individual number of SBP measurements. Ethnicity was associated with change. The model provides a tool to evaluate and optimize the sampling frequency for 24-hour ABP

    Familial Evaluation in Catecholaminergic Polymorphic Ventricular Tachycardia Disease Penetrance and Expression in Cardiac Ryanodine Receptor Mutation-Carrying Relatives

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    Background-Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome associated with mutations in the cardiac ryanodine receptor gene (RYR2) in the majority of patients. Previous studies of CPVT patients mainly involved probands, so current insight into disease penetrance, expression, genotype-phenotype correlations, and arrhythmic event rates in relatives carrying a RYR2 mutation is limited. Methods and Results-One-hundred sixteen relatives carrying a RYR2 mutation from 15 families who were identified by cascade screening of the RYR2 mutation causing CPVT in the proband were clinically characterized, including 61 relatives from 1 family. Fifty-four of 108 antiarrhythmic drug-free relatives (50%) had a CPVT phenotype at the first cardiological examination, including 27 (25%) with nonsustained ventricular tachycardia. Relatives carrying a RYR2 mutation in the C-terminal channel-forming domain showed an increased odds of nonsustained ventricular tachycardia (odds ratio, 4.1; 95% CI, 1.5-11.5; P=0.007, compared with N-terminal domain). Sinus bradycardia was observed in 19% of relatives, whereas other supraventricular dysrhythmias were present in 16%. Ninety-eight (most actively treated) relatives (84%) were followed up for a median of 4.7 years (range, 0.3-19.0 years). During follow-up, 2 asymptomatic relatives experienced exercise-induced syncope. One relative was not being treated, whereas the other was noncompliant. None of the 116 relatives died of CPVT during a 6.7-year follow-up (range, 1.4-20.9 years). Conclusions-Relatives carrying an RYR2 mutation show a marked phenotypic diversity. The vast majority do not have signs of supraventricular disease manifestations. Mutation location may be associated with severity of the phenotype. The arrhythmic event rate during follow-up was low. (Circ Arrhythm Electrophysiol. 2012;5:748-756.
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