Stability and boundary equilibrium bifurcations of modified Chua's circuit with smooth degree of 3

Chua＇s circuit is a well-known nonlinear electronic model, having complicated nonsmooth dynamic behaviors. The stability and boundary equilibrium bifurcations for a modified Chua＇s circuit system with the smooth degree of 3 are studied. The parametric areas of stability are specified in detail. It is found that the bifurcation graphs of the su- percritical and irregular pitchfork bifurcations are similar to those of the piecewise-smooth continuous （PWSC） systems caused by piecewise smoothness. However, the bifurcation graph of the supercritical Hopf bifurcation is similar to those of smooth systems. There- fore, the boundary equilibrium bifurcations of the non-smooth systems with the smooth degree of 3 should receive more attention due to their special features.

Information Transmitting and Cognition with a Spiking Neural Network Model

Information encoding plays a crucial role in neuroscience. One of the fundamental questions in cognitive ncu- roscienee is how the brain encodes external stimuli in the sensory cortex. We use a network model based on the Hodgkin-Huxley type to study the information transmitting including its storage and recall. The model is inspired by psychological and neurobiological evidence on sequential memories. The model contains excitatory and inhibitory neurons with all-to-all connections whose architecture has two layers. A lower layer represents consecutive events during the information encoding process, and the upper layer is used to tag sequences of events represented in the lower layer. The spike-timing-dependent plasticity learning rule is used for sequential storage of excitatory connections between the modules. Computer simulations demonstrate that the synchronization status of multiple neurons is dependent on the network connectivity patterns, and also this model has good performance for different sequences of storage and recall.

Mutant rs189037 in ataxia-telangiectasia mutated gene had a negative association with metabolic syndrome but not cognitive decline in centenarians

Approximately 20%-25%of adults encounter metabolic syndrome(MetS)worldwide,and MetS is a riskfactorfor cognitive decline(CD)development.Patients with MetS have an 11.48-fold increased incidence of CD compared with those without Mets.^(1) Ataxia-telangiectasia mutated(ATM)gene encodes ATM kinase,which belongs to the phosphatidylinositol 3-hydroxy kinase family.