ABSTRACT
A novel autonomous 5-D hyperjerk RC circuit with hyperbolic sine function is proposed in this paper. Compared to some existing 5-D systems like the 5-D Sprott B system, the 5-D Lorentz, and the Lorentz-like systems, the new system is the simplest 5-D system with complex dynamics reported to date. Its simplicity mainly relies on its nonlinear part which is synthetized using only two semiconductor diodes. The system displays only one equilibrium point and can exhibit both periodic and chaotic dynamical behavior. The complex dynamics of the system is investigated by means of bifurcation analysis. In particular, the striking phenomenon of multistability is revealed showing up to seven coexisting attractors in phase space depending solely on the system's initial state. To the best of author's knowledge, this rich dynamics has not yet been revealed in any 5-D dynamical system in general or particularly in any hyperjerk system. Pspice circuit simulations are performed to verify theoretical/numerical analysis.
ABSTRACT
Deuterium δD isotopic analysis is increasingly being used to trace wildlife movement, and undoubtedly has much to offer in this respect, but questions still remain as to the feasibility and practicality of the method in ecology. Here we report our attempt to determine the geographic origin of an auxiliary hoverfly, Episyrphus balteatus, in south-western France. We used quantile regression to calculate the minimum separation distance, based on the International Atomic Energy Agency/World Meteorological Organization (IAEA/WMO) data, at which two insects could be said to originate from different latitudes with a given degree of confidence. We collected larvae in spring 2007 and 2009 to obtain the δD signal of indigenous hoverflies and we trapped adults during one complete year (from Dec. 2006 to Nov. 2007). The smallest separation distance calculated was about 1400 km in western Europe. Our results revealed greater variability in δD of adults in autumn than in spring. From this we infer an autumnal migration. Because of the presence of mountains and the Mediterranean Sea, the δD gradient in precipitation in western Europe is less clear than on the American continent, where it has been used successfully to infer geographical origins of animals under certain conditions. Despite the complications encountered in Europe, the minimum separation distance model proved a useful first step to obtain a first range of possible origins of E. balteatus and the application of the model to other arthropod species in Europe warrants investigation.
