12 research outputs found

    PC-SNN: Supervised Learning with Local Hebbian Synaptic Plasticity based on Predictive Coding in Spiking Neural Networks

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    Deemed as the third generation of neural networks, the event-driven Spiking Neural Networks(SNNs) combined with bio-plausible local learning rules make it promising to build low-power, neuromorphic hardware for SNNs. However, because of the non-linearity and discrete property of spiking neural networks, the training of SNN remains difficult and is still under discussion. Originating from gradient descent, backprop has achieved stunning success in multi-layer SNNs. Nevertheless, it is assumed to lack biological plausibility, while consuming relatively high computational resources. In this paper, we propose a novel learning algorithm inspired by predictive coding theory and show that it can perform supervised learning fully autonomously and successfully as the backprop, utilizing only local Hebbian plasticity. Furthermore, this method achieves a favorable performance compared to the state-of-the-art multi-layer SNNs: test accuracy of 99.25% for the Caltech Face/Motorbike dataset, 84.25% for the ETH-80 dataset, 98.1% for the MNIST dataset and 98.5% for the neuromorphic dataset: N-MNIST. Furthermore, our work provides a new perspective on how supervised learning algorithms are directly implemented in spiking neural circuitry, which may give some new insights into neuromorphological calculation in neuroscience.Comment: 15 pages, 11fig

    Cellular network based multistatic integrated sensing and communication systems

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    A novel multistatic integrated sensing and communication (ISAC) system based on cellular network is proposed. It can make use of widespread base stations (BSs) to perform cooperative sensing in wide area. This system is important since the deployment of sensing function can be achieved upon the mobile communication network at low complexity and cost without modifying the architecture of BSs for full duplexing. In this work, the topology of sensing cell is first provided, which can be duplicated to seamlessly cover the cellular network. Each sensing cell consists of a single central BS transmitting signals and multiple neighboring BSs receiving reflected signals from sensing objects. Then an estimating approach is described for obtaining position and velocity of sensing objects that locate in the sensing cell. Joint data processing with an efficient optimization method is also provided. In addition, key issues in the cellular network based multistatic ISAC system are analyzed. Simulation results show that the multistatic ISAC system can reduce interference power by over 10 dBm and significantly improve position and velocity estimation accuracy of objects when compared with the monostatic ISAC system, demonstrating the effectiveness and promise of implementing the proposed system in the mobile network

    Silencing an E3 Ubiquitin Ligase Gene <i>OsJMJ715</i> Enhances the Resistance of Rice to a Piercing-Sucking Herbivore by Activating ABA and JA Signaling Pathways

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    The RING-type E3 ubiquitin ligases play an important role in plant growth, development, and defense responses to abiotic stresses and pathogens. However, their roles in the resistance of plants to herbivorous insects remain largely unknown. In this study, we isolated the rice gene OsJMJ715, which encodes a RING-domain containing protein, and investigated its role in rice resistance to brown planthopper (BPH, Nilaparvata lugens). OsJMJ715 is a nucleus-localized E3 ligase whose mRNA levels were upregulated by the infestation of gravid BPH females, mechanical wounding, and treatment with JA or ABA. Silencing OsJMJ715 enhanced BPH-elicited levels of ABA, JA, and JA-Ile as well as the amount of callose deposition in plants, which in turn increased the resistance of rice to BPH by reducing the feeding of BPH and the hatching rate of BPH eggs. These findings suggest that OsJMJ715 negative regulates the BPH-induced biosynthesis of ABA, JA, and JA-Ile and that BPH benefits by enhancing the expression of OsJMJ715

    Prevalence, Risk Factors, and Causes of Visual Impairment in an Elderly Chinese Uygur Population in Southern Xinjiang

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    Purpose. To investigate the prevalence, risk factors, and major causes of visual impairment (VI) in an elderly Chinese Uygur population in southern Xinjiang. Methods. This was a population-based cross-sectional study. Participants aged 50 years and older from Haohan Country, Xinjiang Uygur Autonomous Region, were enrolled from August 2018 to December 2018 using cluster sampling. Participants underwent examinations including presenting visual acuity (PVA), pinhole vision, slit-lamp, intraocular pressure, and direct ophthalmoscopy. Participants’ education and demographic information was collected by a questionnaire. The prevalence, risk factors, and major causes of vision loss were evaluated. Results. A total of 1465 participants (85.4% response rate) were enrolled. The mean age of the subjects was 59.1 ± 9.7 years. The prevalence of mild VI, moderate VI, severe VI, and blindness in the better eye was 13.3%, 12.8%, 2.9%, and 3.4%, respectively. The prevalence of low vision and blindness in this study was higher than that in Altay & Tacheng and Changji in northern Xinjiang, lower than that in Luxi, and similar to that in Tibet. The multiple logistic regression analysis showed that age, education level, and body mass index (BMI) were significantly associated with low vision and blindness (P≤0.001,<0.05,0.002, respectively). The major causes of low vision were cataract (42.6%), refractive error (19.6%), and glaucoma (12.6%), whereas the primary causes of blindness were cataract (34%), glaucoma (34%), and retinitis pigmentosa (10%). Conclusions. VI is an important public health issue among elderly Uygur individuals in the area, especially for those with low education levels. Cataract is the leading cause of low vision and blindness

    Multistatic Integrated Sensing and Communication System Based on Macro–Micro Cooperation

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    A novel multistatic integrated sensing and communication (ISAC) system based on macro–micro cooperation for the sixth-generation (6G) mobile network is proposed. Instead of using macrosites at both the transmitter and receiver sides, microsites are considered as receivers in cooperative sensing. This system is important since microsites can be deployed more flexibly to reduce their distances to the sensing objects, providing better coverage for sensing service. In this work, we first analyze the deployment problem of microsites, which can be deployed along the radius and azimuth angle to cover macrosite cells. The coverage area of each microsite is derived in terms of its position in the cell. Then, we describe an efficient estimating approach for obtaining the position and velocity of sensing objects in the macrosite cell. By choosing multiple microsites around the targeted sensing area, joint data processing with an efficient optimization method is also provided. Simulation results show that the multistatic ISAC system employing macro–micro cooperation can improve the position and velocity estimation accuracy of objects compared to systems employing macrosite cooperation alone, demonstrating the effectiveness and potential for implementing the proposed system in the 6G mobile network

    OsMKK3, a Stress-Responsive Protein Kinase, Positively Regulates Rice Resistance to Nilaparvata lugens via Phytohormone Dynamics

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    Plants undergo several but very precise molecular, physiological, and biochemical modulations in response to biotic stresses. Mitogen-activated protein kinase (MAPK) cascades orchestrate multiple cellular processes including plant growth and development as well as plant responses against abiotic and biotic stresses. However, the role of MAPK kinases (MAPKKs/MKKs/MEKs) in the regulation of plant resistance to herbivores has not been extensively investigated. Here, we cloned a rice MKK gene, OsMKK3, and investigated its function. It was observed that mechanical wounding, infestation of brown planthopper (BPH) Nilaparvata lugens, and treatment with methyl jasmonate (MeJA) or salicylic acid (SA) could induce the expression of OsMKK3. The over-expression of OsMKK3 (oe-MKK3) increased levels of jasmonic acid (JA), jasmonoyl-L-isoleucine (JA-Ile), and abscisic acid (ABA), and decreased SA levels in rice after BPH attack. Additionally, the preference for feeding and oviposition, the hatching rate of BPH eggs, and BPH nymph survival rate were significantly compromised due to over-expression of OsMKK3. Besides, oe-MKK3 also augmented chlorophyll content but impaired plant growth. We confirm that MKK3 plays a pivotal role in the signaling pathway. It is proposed that OsMKK3 mediated positive regulation of rice resistance to BPH by means of herbivory-induced phytohormone dynamics

    Effects of the CYP3A inhibitors, voriconazole, itraconazole, and fluconazole on the pharmacokinetics of osimertinib in rats

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    Background Osimertinib, as third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is the first-line treatment approved to treat advanced T790M mutation-positive tumors. Triazole antifungals are therapeutic drugs for cancer patients to reduce the risk of opportunistic fungal infections. Our objective was to investigate whether three triazole antifungals (voriconazole, itraconazole, and fluconazole) could change the pharmacokinetics of osimertinib in rats. Methods The adult male Sprague-Dawley rats were randomly divided into four groups (n = 6): control (0.3% CMC-Na), and voriconazole (20 mg/kg), itraconazole (20 mg/kg), or fluconazole (20 mg/kg) combined with osimertinib (10 mg/kg) group. Tail vein blood samples were collected into heparin tubes at various time points within 0–48 h after osimertinib administration. Osimrtinib’s plasma concentration was detected using HPLC-MS/MS system equipped with a Waters XBridge C18 column, with the mobile phase consisting of acetonitrile and 0.2% formic acid water at a flow rate of 0.5 mL/min. Results Co-administration with voriconazole or fluconazole increased the Cmax of osimertinib by 58.04% and 53.45%, respectively; the AUC0–t increased by 62.56% and 100.98%, respectively. However, when co-administered with itraconazole, the Cmax and AUC0–t of osimertinib only increased by 13.91% and 34.80%, respectively. Conclusions Our results revealed that the pharmacokinetics of osimertinib were significantly changed by voriconazole and fluconazole in rats, whereas it was slightly affected by itraconazole. This work will contribute to a more comprehensive understanding of the pharmacokinetic properties of osimertinib when co-administered with triazole antifungals
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