ChebNet: Efficient and Stable Constructions of Deep Neural Networks with Rectified Power Units using Chebyshev Approximations

In a recent paper [B. Li, S. Tang and H. Yu, arXiv:1903.05858], it was shown that deep neural networks built with rectified power units (RePU) can give better approximation for sufficient smooth functions than those with rectified linear units, by converting polynomial approximation given in power series into deep neural networks with optimal complexity and no approximation error. However, in practice, power series are not easy to compute. In this paper, we propose a new and more stable way to construct deep RePU neural networks based on Chebyshev polynomial approximations. By using a hierarchical structure of Chebyshev polynomial approximation in frequency domain, we build efficient and stable deep neural network constructions. In theory, ChebNets and the deep RePU nets based on Power series have the same upper error bounds for general function approximations. But numerically, ChebNets are much more stable. Numerical results show that the constructed ChebNets can be further trained and obtain much better results than those obtained by training deep RePU nets constructed basing on power series.Comment: 18 pages, 6 figures, 2 table

MicroRNA expression profiling in human acute organophosphorus poisoning and functional analysis of dysregulated miRNAs

Objective: Acute organophosphorus(OP) pesticide poisoning is associated with dysfunctions in multiple organs, especially skeletal muscles, the nervous system and the heart. However, little is known about the specific microRNA (miRNA) changes that control the pathophysiological processes of acute OP poisoning damage. We aimed to explore miRNA expression profiles and gain insight into molecular mechanisms of OP toxic effects.Methods: MicroRNA expression was analyzed by TaqMan Human MicroRNA Array analysis and subsequent validated with quantitive PCR. The targets of the significantly different miRNAs were predicted with miRNA prediction databases, and pathway analysis of the predicted target genes was performed using bioinformatics resources.Results: 37 miRNAs were significantly different in the sera of poisoned patients compared to the healthy controls, including 29 miRNAs that were up-regulated and 8 miRNAs that were down-regulated. Functional analysis indicated that many pathways potentially regulated by these miRNAs are involved in skeletal muscle, nervous system and heart disorders.Conclusion: This study mapped changes in the serum miRNA expression profiles of poisoning patients and predicted functional links between miRNAs and their target genes in the regulation of acute OP poisoning. Our findings are an important resource for further understanding the role of these miRNAs in the regulation of OP-induced injury.Keywords: MicroRNA, expression profiles, human, acute organophosphorus pesticide poisoning, signaling pathways

Storm-induced changes in pCO2 at the sea surface over the northern South China Sea during Typhoon Wutip

In situ oceanographic measurements were made before and after the passage of Typhoon Wutip in September 2013 over the northern South China Sea. The surface geostrophic circulation over this region inferred from satellite altimetry data features a large‐size anticyclonic eddy, a small‐size cyclonic eddy, and smaller‐size eddies during this period. Significant typhoon‐induced changes occurred in the partial pressure of CO2 at the sea surface (pCO2sea) during Wutip. Before the passage of Wutip, pCO2sea was about 392.92 ± 1.83, 390.31 ± 0.50, and 393.04 ± 4.31 μatm over the cyclonic eddy water, the anticyclonic eddy water, and areas outside two eddies, respectively. The entire study region showed a carbon source (1.31 ± 0.46 mmol CO2 m?2 d?1) before Wutip. In the cyclonic eddy water after Wutip, high sea surface salinity (SSS), low sea surface temperature (SST), and high pCO2sea (413.05 ± 7.56 μatm) made this area to be a carbon source (3.30 ± 0.75 mmol CO2 m?2 d?1). In the anticyclonic eddy water after Wutip, both the SSS and SST were lower, pCO2sea was also lower (383.03 ± 3.72 μatm), and this area became a carbon sink (-0.11 ± 0.55 mmol CO2 m?2 d?1), in comparison with the pretyphoon conditions. The typhoon‐induced air‐sea CO2 flux reached about 0.03 mmol CO2 m?2 d?1. Noticeable spatial variations in pCO2sea were affected mainly by the typhoon‐induced mixing/upwelling and vertical stratifications. This study suggests that the local air‐sea CO2 flux in the study region was affected significantly by oceanographic conditions during the typhoon

Controllable distant interactions at bound state in the continuum

Distant interactions at arbitrary locations and their dynamic control are fundamentally important for realizing large-scale photonic and quantum circuits. Conventional approaches suffer from short coupling distance, poor controllability, fixed locations and low wavelength uniformity, significantly restricting the scalability of photonic and quantum networks. Here, we exploit the intrinsic advantages of optical bound state in the continuum (BIC) and demonstrate an all-in-one solution for dynamically controllable long-range interactions. BIC metasurface can support a series of finite-sized quasi-BIC microlasers at arbitrary locations. The quasi-BICs microlasers have the same wavelength and are inherently connected through BIC waveguide. Consequently, the coupling distances in experiment increase significantly from subwavelength to tens of micrometers. Such long-range interaction in BIC metasurface enables scaling to two-dimensional architectures and ultrafast control of internal laser actions, e.g., non-Hermitian zero-mode lasing and enhanced optical gain. This research shall facilitate the advancement of scalable and reconfigurable photonic networks.Comment: 12 pages, 4 figure