Synchronization of coupled reaction-diffusion neural networks: Delay-dependent pinning impulsive control

The final publication is available at Elsevier via https://doi.org/10.1016/j.cnsns.2019.104905. © 2019. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper studies the synchronization problem of coupled reaction-diffusion neural networks with time-varying delays. A novel pinning impulsive controller is proposed, where distributed delays and discrete delays are taken into account, respectively. By using the Lyapunov–Krasovskii method, the relations among impulsive gains, pinned node numbers, impulsive intervals, impulsive instants and time delays are derived. Exponential synchronization criteria are established for the delayed coupled reaction-diffusion neural networks. Our results show that synchronization of the neural networks can be achieved by controlling a small portion of nodes in the networks via delayed impulses. Numerical examples are provided to demonstrate the effectiveness of the theoretical results.This work was supported in part by the China Scholarship Council, the Australian Research Council under Grant DP160102819, the NSERC Canada, and the National Natural Science Foundation of China under Grant No.51625601

Models to Assess the Effects of Nonsmooth Control and Stochastic Perturbation on Pest Control: A Pest-Natural-Enemy Ecosystem

This paper investigates the impact of the threshold control strategy and environmental randomness on pest control. Firstly, a fixed-time impulsive stochastic ecosystem with IPM strategy is proposed, where the local and global existence of positive solution and the boundedness of expectation are discussed in detail. Moreover a sufficient condition for the extinction of the pest population with probability-1 is given. Then, a state-dependent stochastic ecosystem with IPM strategy is proposed. By employing the numerical simulations, the effects of ambient noise intensity on pest-outbreak are discussed. The result shows that there is a close relationship among the frequency of pest-outbreak, ET, the environmental perturbation intensity, and control measures. This study helps us to understand the impact of random factors on pest-outbreak frequency by theoretical derivations and numerical simulations; the results have directive significance in the design of an optimal control strategy for the department of ecological agriculture

Study on Effect of Particle Size Distribution on Water-Retention Capacity of Coral Sand from Macro and Micro Perspective

The reclamation coral sand (CS) layer is the survival environment for island reef vegetation in the South China Sea. The root system within the CS bed draws water necessary for vegetation growth, implying that the water-retention capacity of CS plays a pivotal role in determining vegetation viability. Particle size distribution (PSD) significantly influences the water-retention capacity of geomaterials. This study examines the impact of PSD on the water-retention capacity of CS from both macro (soil–water characteristic curve, SWCC) and micro (pore water distribution) perspectives using the pressure plate test and nuclear magnetic resonance technique, and an F&X model was used to analyze the SWCC of CS. The findings indicated that the F&X model aptly describes the SWCC of CS with different PSDs. Both the air entry value and residual water content rise with an increased content of fine grains (d d = 0.075–0.25 mm predominantly impacts the water-retention capacity of CS. The PSD primarily influences the water-retention capacity by affecting the pore size distribution of CS. The volume of small pores swells with the surge of fine-grain content, while the maximum pore size contracts with increasing fine-grain content. Limited pore connectivity in CS means macropores can retain water even under high suction, bolstering the water-retention capacity of CS. These findings offer theoretical guidance for selecting gradation parameters for the planting layer on island reefs

Improve unsupervised Learning-based landslides detection by band ratio processing of RGB optical images: a case study on rainfall-induced landslide clusters

Automatic detection of the heavy rainfall-induced landslide clusters based on optical remote sensing images had low accuracy due to the interference of many features. This work proposes a method to improve the accuracy of landslide identification based on change detection of pre- and post-disaster satellite images. Firstly, by band ratio preprocessing, the interference features on landslide detection are eliminated. Then, by further optimizing the relevant parameters, the threshold-based Image Difference and Principal Component Analysis-based K-means unsupervised learning classification methods are used to perform change detection and landslide cluster identification. Finally, the causes of missing and errors in landslide detection by using the two methods are analyzed and discussed. The results show that band preprocessing of remote sensing images can significantly weaken the interference features of human activities on landslide detection. The verification metrics of the two methods for detecting landslides, except for a slight decrease in precision, recall, F1-score and Kappa values have all increased significantly. After band ratio preprocessing and parameters optimization, both change detection methods have significantly improved the performance of the rainfall-induced landslide clusters detection, with effects close to those of deep learning methods. These findings can provide a reference for landslide detection using optical remote-sensing images

Rural integrated sanitation assessment at community level in Chongqing, China—A cluster analysis

Equitable access to sanitation for all is a goal of sustainable development, notably in rural areas. However, studies including economic, socio-cultural, and other factors that have been conducted to comprehensively assess rural sanitation at the community level in developing countries are limited. This study aimed to investigate the current state of rural environmental sanitation on the community level and to evaluate the characteristics of the diverse sub-clusters. A multidimensional environmental sanitation survey was conducted on 400 communities in Chongqing, China in 2020, and the priority options for improving sub-clusters’ sanitation were explored using cluster analysis. Among all communities, more than 60 % had positive village appearance, 50.50 % had domestic sewage treatment, and the coverage rate of household sanitary toilets was 72.28 %. The average content for lead, cadmium (Cd), and chromium in soil was 26.01, 0.53, and 54.47 mg/kg, respectively. The communities were clustered into 3 groups (I, II, III) based on similar characteristics including basic information, village appearance, water, sanitation, hygiene management, bio-vector control, and soil pollution. The proportion of cluster I, II, and III was 39.25 % (157/400), 31.75 % (127/400), and 29.00 % (116/400), respectively. Each cluster had its sanitation characteristics, and significant differences among the sub-clusters were observed in Cd of soil (p = 0.001), domestic sewage disposal ratio (p < 0.001), and environmental health funding (p = 0.001). To sum up, the environmental sanitation in rural areas of Chongqing was better than that of the national average in China, but the Cd content of farmland soil was higher. Our study provides novel evidence for assessing the characteristics of rural sanitation at the community level, and communities with similar environmental health status were clustered into the same group, while the heterogeneity of different sub-cluster was thoroughly characterized. The hierarchical control strategy should be performed in communities based on different characteristics and deficiencies of the clusters to improve environmental sanitation

Outbreak of Acute Gastroenteritis Caused by Norovirus Genogroup II Attributed to Contaminated Cold Dishes on a Cruise Ship in Chongqing, China, 2017

In April 2017, several travelers with acute gastroenteritis on a cruise ship were reported. We conducted an investigation to identify the pathogen, mode of transmission, and risk factors. We searched and classified case-patient according to structured case definition, and collect date of the onset, clinical manifestations, and demographic information of cases. A case-control study was implemented to compare foods consumption between cases and asymptomatic travelers. Samples such as feces, rectal swab, vomitus, and environment swab were collected for testing. The attack rate was 18.2% (101/555), four cold dishes served on 11th, April were independently associated with an increased risk of disease: cold potherb (odds ratio (OR): 14.4; 95% confidence interval (CI): 2.2&#8315;93.3) and cold garlic sprout (OR: 26.1; 95% CI: 4.9&#8315;138.0) served at lunch, cold broad bean (OR: 5.8; 95% CI: 1.3&#8315;26.2), and cold cucumber (OR: 13.9; 95% CI: 2.3&#8315;84.2) served at dinner. A total of 15 samples were positive for norovirus genogroup II (GII) by using reverse transcription polymerase chain reaction (RT-PCR). This outbreak that occurred on the cruise ship was caused by norovirus GII. The evidence indicated that norovirus was mainly transmitted through consumption of cold dishes on 11th, April, which might be contaminated by asymptomatic cold dish cook

Up-regulated expression and aberrant DNA methylation of LEP and SH3PXD2A in pre-eclampsia.

The primary mechanism underlying pre-eclampsia (PE) remains one of the most burning problems in the obstetrics and gynecology. In this study, we performed an expression profiling screen and detected 1312 genes that were differentially expressed (p1.5) in PE placentas, including LEP and SH3PXD2A. After validating the microarray results, we conducted the quantitative methylation analysis of LEP and SH3PXD2A in preeclamptic (n = 16) versus normal placentas (n = 16). Our results showed that many CpG sites close to the transcriptional start site (TSS) of LEP gene were hypomethylated in placentas from pregnancies with PE compared with those of in controls, including the TSS position (p = 0.001), the binding sites of Sp1 (p = 1.57×10(-4)), LP1 (p = 0.023) and CEBPα (p = 0.031). Luciferase reporter analysis confirmed the aberrant methylation of LEP promoter and CEBPα co-transfection had a role in the regulation of gene expression. Our results indicated the aberrant LEP promoter methylation was involved in the development of PE. We did not find a significant methylation differences between groups in the promoter region of SH3PXD2A, however, a CGI region in the gene body (CGI34) presented a higher methylation in preeclamptic placentas (p = 1.57×10(-4)), which might promote the efficiency of gene transcription. We speculated that SH3PXD2A may take part in the pathogenesis of PE through its role in the regulation of trophoblast cell invasion in the period of placenta formation

Polarization Splitting at Visible Wavelengths with the Rutile TiO₂ Ridge Waveguide

On-chip polarization control is in high demand for novel integrated photonic applications such as polarization division multiplexing and quantum communications. However, due to the sensitive scaling of the device dimension with wavelength and the visible-light absorption properties, traditional passive silicon photonic devices with asymmetric waveguide structures cannot achieve polarization control at visible wavelengths. In this paper, a new polarization-splitting mechanism based on energy distributions of the fundamental polarized modes in the r-TiO2 ridge waveguide is investigated. The bending loss for different bending radii and the optical coupling properties of the fundamental modes in different r-TiO2 ridge waveguide configurations are analyzed. In particular, a polarization splitter with a high extinction ratio operating at visible wavelengths based on directional couplers (DCs) in the r-TiO2 ridge waveguide is proposed. Polarization-selective filters based on micro-ring resonators (MRRs) with resonances of only TE or TM polarizations are designed and operated. Our results show that polarization-splitters for visible wavelengths with a high extinction ratio in DC or MRR configurations can be achieved with a simple r-TiO2 ridge waveguide structure

Peptide-anchored neutrophil membrane-coated biomimetic nanodrug for targeted treatment of rheumatoid arthritis

Abstract Macrophage polarization determines the production of cytokines that fuel the initiation and evolution of rheumatoid arthritis (RA). Thus, modulation of macrophage polarization might represent a potential therapeutic strategy for RA. However, coordinated modulation of macrophages in the synovium and synovial fluid has not been achieved thus far. Herein, we develop a biomimetic ApoA-I mimetic peptide-modified neutrophil membrane-wrapped F127 polymer (R4F-NM@F127) for targeted drug delivery during RA treatment. Due to the high expression of adhesion molecules and chemokine receptors on neutrophils, the neutrophil membrane coating can endow the nanocarrier with synovitis-targeting ability, with subsequent recruitment to the synovial fluid under the chemotactic effects of IL-8. Moreover, R4F peptide modification further endows the nanocarrier with the ability to target the SR-B1 receptor, which is highly expressed on macrophages in the synovium and synovial fluid. Long-term in vivo imaging shows that R4F-NM@F127 preferentially accumulates in inflamed joints and is engulfed by macrophages. After loading of the anti-inflammatory drug celastrol (Cel), R4F-NM@F127-Cel shows a significant reduction in hepatotoxicity, and effectively inhibits synovial inflammation and alleviates joint damage by reprogramming macrophage polarization. Thus, our results highlight the potential of the coordinated targeted modulation of macrophages as a promising therapeutic option for the treatment of RA