Presence Of Cycling Research Articles

Effect of morphine on cerebral activity of extremely premature infants

BackgroundMorphine is widely used for sedation in premature infants and may have long-term effects on neurodevelopmental outcome. AimsTo assess its effect on cerebral activity of extremely preterm infants. MethodsRetrospective study in infants less than 28 weeks of gestational age (GA), treated with morphine and monitored with amplitude integrated EEG (aEEG), that were assessed at baseline and 6 consecutive 2 h periods. At each period, the background activity score and presence of cycling were determined. ResultsA total of 140 infants were included. Background aEEG activity score worsened in 40% of the infants by 6 h after morphine initiation and cycling, initially present in 70% of the infants, could be detected in only 10% after 10 h. On multivariable analysis, adjusted for baseline aEEG score and GA, the background activity decreased by 0.85 (95% confidence interval (CI): 0.74–0.97) immediately after morphine initiation, 0.72 (CI: 0.63–0.83) at 2 h later and on average by 0.64 (CI: 0.57–0.71) at each subsequent 2 h periods. The relative risk of cycling loss at 2 h and 4 h after morphine administration was 1.58 (CI: 1.15–2.16) and 3.37 (CI: 2.23–5.08), respectively. ConclusionsContinuous infusion of morphine in extremely preterm infants significantly depresses their cerebral activity soon after its commencement.

The Problems of Financial Cycle Modeling in the Globalization of Financial Markets

Abstract Economic globalization and the rapid development of financial markets has led to increased instability in global financial and credit sphere. Crises of the early 2000s raised the question of the need for in-depth study of the structure and dynamics of financial markets. In this paper the methodology of modeling financial market as a nonlinear dynamical system is studied. Based on the analysis of stochastic differential equations concluded that the probable presence of cycling in the capital market. Estimated synergetic role of derivatives in causing the crisis shocks.

Exit cycling for the Van der Pol oscillator and quasipotential calculations

We discuss the phenomenon of cycling for noise induced escape to a unstable periodic orbit. The presence of cycling is shown to follow from qualitative properties of two quasipotential functions. A method of numerically evaluating these quasipotential functions is described, and applied to the Van der Pol oscillator as an example. Figures resulting from these calculations reveal that nonconvergent cycling of exit measures does occur for the Van der Pol example.