Does the Box-Cox transformation help in forecasting macroeconomic time series?

The paper investigates whether transforming a time series leads to an improvement in forecasting accuracy. The class of transformations that is considered is the Box-Cox power transformation, which applies to series measured on a ratio scale. We propose a nonparametric approach for estimating the optimal transformation parameter based on the frequency domain estimation of the prediction error variance, and also conduct an extensive recursive forecast experiment on a large set of seasonal monthly macroeconomic time series related to industrial production and retail turnover. In about one fifth of the series considered the Box-Cox transformation produces forecasts significantly better than the untransformed data at one-step-ahead horizon; in most of the cases the logarithmic transformation is the relevant one. As the forecast horizon increases, the evidence in favour of a transformation becomes less strong. Typically, the naïve predictor that just reverses the transformation leads to a lower mean square error than the optimal predictor at short forecast leads. We also discuss whether the preliminary in-sample frequency domain assessment conducted provides a reliable guidance which series should be transformed for improving significantly the predictive performance

The OhioLINK Digital Media Center Application Profile: A New Tool for Ohio Digital Collections

Contains fulltext : 219863.pdf (Publisher’s version ) (Open Access)OBJECTIVES: Our goal was to report the long-term serial follow-up after transatrial-transpulmonary repair of tetralogy of Fallot (TOF) and to describe the influence of the timing of the repair on outcome. METHODS: We included all patients with TOF who had undergone transatrial-transpulmonary repair between 1970 and 2012. Records were reviewed for patient demographics, operative details and events during the follow-up period (death, pulmonary valve replacement, cardiac reinterventions and hospitalization/intervention for arrhythmias). In patients with elective early primary repair of TOF after 1990, a subanalysis of the optimal timing of TOF repair was performed. RESULTS: A total of 453 patients were included (63% male patients; 65% had transannular patch); 261 patients underwent primary elective repair after 1990. The median age at TOF repair was 0.7 years (25th-75th percentile 0.3-1.3) and decreased from 1.7 to 0.4 years from before 1990 to after 2000, respectively (P < 0.001). The median follow-up duration after TOF repair was 16.8 years (9.6-24.7). Events developed in 182 (40%) patients. In multivariable analysis, early repair of TOF (<6 months) [hazard ratio (HR) 3.06; P < 0.001] and complications after TOF repair (HR 2.18; P = 0.006) were found to be predictive for an event. In a subanalysis of the primary repair of TOF after 1990, the patients (n = 125) with elective early repair (<6 months) experienced significantly worse event-free survival compared to patients who had elective repair later (n = 136). In multivariable analysis, early repair (HR 3.00; P = 0.001) and postoperative complications (HR 2.12; P = 0.010) were associated with events in electively repaired patients with TOF. CONCLUSIONS: Transatrial-transpulmonary repair of TOF before the age of 6 months may be associated with more events during the long-term follow-up period

Resection of a cardiac aneurysm in an infant with anomalous origin of the left coronary artery from the pulmonary trunk.

Contains fulltext : 57512.pdf (publisher's version ) (Closed access)We describe an infant with an anomalous left coronary artery arising from the pulmonary trunk leading to myocardial ischaemia and development of an apical aneurysm of the left ventricle. Clinical presentation in general is based on myocardial hypoperfusion resulting in ischaemia and infarction. When presenting in infancy, however, then the features, as in our patient, may be tachypnea, dyspnea, failure to thrive and irritability, especially during feeding. Then, again as in our patient, it is possible to miss the definitive diagnosis, which is made by echocardiography and cardiac catheterization. Reimplantation of the anomalous left coronary artery into the aorta usually results in improvement of left ventricular function over time. In our patient, the myocardial infarction was complicated by formation of an aneurysm, and reimplantation alone was not sufficient to restore cardiac function. Resection of the aneurysm greatly improved the hemodynamics

Absent pulmonary valve syndrome with intact ventricular septum and patent ductus arteriosus: report of two cases and a short review of the literature.

Item does not contain fulltextWe describe two patients who both presented shortly after birth with congestive heart failure due to an absent pulmonary valve and patent ductus arteriosus. Diagnostic evaluation revealed in both cases an aneurysmatic dilation of the pulmonary vascular tree and an abundant left-to-right shunt over a large patent ductus arteriosus. Ventricular septal defects were not detected. Early surgical closure of the patent ductus arteriosus improved the hemodynamic situation so that implantation of a homograft valve could be delayed

Chronische centrale cyanose bij kinderen; altijd een reden voor nadere diagnostiek

Contains fulltext : 25438___.PDF (publisher's version ) (Open Access

ERP signal analysis with temporal resolution using a time window bank

Contains fulltext : 208217.pdf (publisher's version ) (Open Access)Interspeech 2019. Crossroads of Speech and Language, 15 september 201