A Nonlinear System Identification Method Based on Adaptive Neural Network

Nonlinear system identification (NSI) is of great significance to modern scientific engineering and control engineering. Despite their identification ability, the existing analysis methods for nonlinear systems have several limitations. The neural network (NN) can overcome some of these limitations in NSI, but fail to achieve desirable accuracy or training speed. This paper puts forward an NSI method based on adaptive NN, with the aim to further improve the convergence speed and accuracy of NN-based NSI. Specifically, a generic model-based nonlinear system identifier was constructed, which integrates the error feedback and correction of predictive control with the generic model theory. Next, the radial basis function (RBF) NN was optimized by adaptive particle swarm optimization (PSO), and used to build an NSI model. The effectiveness and speed of our model were verified through experiments. The research results provide a reference for applying the adaptive PSO-optimized RBFNN in other fields

Gene-Expression Changes in Cerium Chloride-Induced Injury of Mouse Hippocampus

<div><p>Cerium is widely used in many aspects of modern society, including agriculture, industry and medicine. It has been demonstrated to enter the ecological environment, is then transferred to humans through food chains, and causes toxic actions in several organs including the brain of animals. However, the neurotoxic molecular mechanisms are not clearly understood. In this study, mice were exposed to 0.5, 1, and 2 mg/kg BW cerium chloride (CeCl₃) for 90 consecutive days, and their learning and memory ability as well as hippocampal gene expression profile were investigated. Our findings suggested that exposure to CeCl₃ led to hippocampal lesions, apoptosis, oxidative stress and impairment of spatial recognition memory. Furthermore, microarray data showed marked alterations in the expression of 154 genes involved in learning and memory, immunity and inflammation, signal transduction, apoptosis and response to stress in the 2 mg/kg CeCl₃ exposed hippocampi. Specifically, the significant up-regulation of Axud1, Cdc37, and Ube2v1 caused severe apoptosis, and great suppression of Adcy8, Fos, and Slc5a7 expression led to impairment of mouse cognitive ability. Therefore, Axud1, Cdc37, Ube2v1, Adcy8, Fos, and Slc5a7 may be potential biomarkers of hippocampal toxicity caused by CeCl₃ exposure.</p> </div

Ultrastructure of hippocampal cells in mice caused by intragastric administration of CeCl₃ for 90 consecutive days (N = 5).

<p>(a) Control group indicates nucleus with homogeneous chromatin; (b) 0.5 mg/kg CeCl₃ group indicates irregularity of nuclear membrane, shrinkage of nucleus, chromatin marginalization, and mitochondrial swelling; (c) 1 mg/kg CeCl₃ group indicates irregularity of nuclear membrane, severe shrinkage of nucleus, chromatin marginalization, and mitochondrial swelling; (c) 2 mg/kg CeCl₃ group indicates significant irregularity of nuclear membrane, severe shrinkage of nucleus, chromatin marginalization, mitochondrial swelling, and ectatic endoplasmic reticulum.</p

Effect of CeCl₃ on the levels of protein expression in mouse

<p><b>hippocampus following intragastric administration of CeCl₃ for 90 consecutive days.</b> Different letters indicate significant differences between groups (p<0.05). Values represent means ± SEM (N = 5).</p

Real time PCR primer pairs. PCR primers used in the gene expression analysis.

<p>Real time PCR primer pairs. PCR primers used in the gene expression analysis.</p

Effect of CeCl₃ on spatial recognition memory in mice in the Y-maze test following intragastric administration of CeCl₃ for 90 consecutive days.

<p>Different letters indicate significant differences between groups (p<0.05). Values represent means ± SEM (N = 20).</p