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11.
António Rua 《Journal of forecasting》2011,30(7):666-678
It has been acknowledged that wavelets can constitute a useful tool for forecasting in economics. Through a wavelet multi‐resolution analysis, a time series can be decomposed into different timescale components and a model can be fitted to each component to improve the forecast accuracy of the series as a whole. Up to now, the literature on forecasting with wavelets has mainly focused on univariate modelling. On the other hand, in a context of growing data availability, a line of research has emerged on forecasting with large datasets. In particular, the use of factor‐augmented models have become quite widespread in the literature and among practitioners. The aim of this paper is to bridge the two strands of the literature. A wavelet approach for factor‐augmented forecasting is proposed and put to test for forecasting GDP growth for the major euro area countries. The results show that the forecasting performance is enhanced when wavelets and factor‐augmented models are used together. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
12.
Morgado M Cairrão E Santos-Silva AJ Verde I 《Cellular and molecular life sciences : CMLS》2012,69(2):247-266
Vascular smooth muscle tone is controlled by a balance between the cellular signaling pathways that mediate the generation
of force (vasoconstriction) and release of force (vasodilation). The initiation of force is associated with increases in intracellular
calcium concentrations, activation of myosin light-chain kinase, increases in the phosphorylation of the regulatory myosin
light chains, and actin-myosin crossbridge cycling. There are, however, several signaling pathways modulating Ca2+ mobilization and Ca2+ sensitivity of the contractile machinery that secondarily regulate the contractile response of vascular smooth muscle to
receptor agonists. Among these regulatory mechanisms involved in the physiological regulation of vascular tone are the cyclic
nucleotides (cAMP and cGMP), which are considered the main messengers that mediate vasodilation under physiological conditions.
At least four distinct mechanisms are currently thought to be involved in the vasodilator effect of cyclic nucleotides and
their dependent protein kinases: (1) the decrease in cytosolic calcium concentration ([Ca2+]c), (2) the hyperpolarization of the smooth muscle cell membrane potential, (3) the reduction in the sensitivity of the contractile
machinery by decreasing the [Ca2+]c sensitivity of myosin light-chain phosphorylation, and (4) the reduction in the sensitivity of the contractile machinery
by uncoupling contraction from myosin light-chain phosphorylation. This review focuses on each of these mechanisms involved
in cyclic nucleotide-dependent relaxation of vascular smooth muscle under physiological conditions. 相似文献