Pre-quake frequency characteristics of Ms ≥7.0 earthquakes in mainland China

In this study, natural orthogonal expansion was performed on earthquake frequencies to compute the pre-quake frequency fields of 9 Ms ≥7.0 earthquakes in mainland China from 1980 to 2020. The temporal and spatial pre-quake anomalies of these earthquakes were extracted from their frequency fields. We found that the majority of pre-quake temporal anomalies (i.e., variations exceeding two-times the absolute mean square error) of a strong earthquake are condensed within the first four frequency fields, and typically comprise multiple components. The temporal factor of the first frequency field usually accounts for the largest proportion of these anomalies (40%–60% of the entire field). Most Ms ≥7.0 earthquakes exhibited long-term anomalies 5–8 years before their occurrence; some presented medium-term anomalies 1–2 years prior to the quake, and only a few presented short-term and imminent anomalies (≤3 months before the quake). Anomalous seismic hazard zones have high-gradient turning points in regional frequency-field contour maps, and the epicenters of strong earthquakes are often located in areas containing active faults that have contour values. Through the comparison of seismic frequency field and the traditional method of regional seismic activity frequency (3 months), it is shown that the frequency-field time factor has the advantages of diversified and rich abnormal information. The slope comparison between the frequency field and the cumulative frequency curve shows that the frequency anomaly time of the two is consistent, and the conclusion is reliable. Therefore, the seismic frequency method can predict the occurrence time and location of strong earthquakes, which is closer to the predictable seismic model

Discrete Bat Algorithm for Optimal Problem of Permutation Flow Shop Scheduling

A discrete bat algorithm (DBA) is proposed for optimal permutation flow shop scheduling problem (PFSP). Firstly, the discrete bat algorithm is constructed based on the idea of basic bat algorithm, which divide whole scheduling problem into many subscheduling problems and then NEH heuristic be introduced to solve subscheduling problem. Secondly, some subsequences are operated with certain probability in the pulse emission and loudness phases. An intensive virtual population neighborhood search is integrated into the discrete bat algorithm to further improve the performance. Finally, the experimental results show the suitability and efficiency of the present discrete bat algorithm for optimal permutation flow shop scheduling problem

An Improved Animal Migration Optimization Algorithm for Clustering Analysis

Animal migration optimization (AMO) is one of the most recently introduced algorithms based on the behavior of animal swarm migration. This paper presents an improved AMO algorithm (IAMO), which significantly improves the original AMO in solving complex optimization problems. Clustering is a popular data analysis and data mining technique and it is used in many fields. The well-known method in solving clustering problems is k-means clustering algorithm; however, it highly depends on the initial solution and is easy to fall into local optimum. To improve the defects of the k-means method, this paper used IAMO for the clustering problem and experiment on synthetic and real life data sets. The simulation results show that the algorithm has a better performance than that of the k-means, PSO, CPSO, ABC, CABC, and AMO algorithm for solving the clustering problem

Network development of low-cost carriers in China's domestic market

This paper examines China's LCC market and assesses the network development patterns from a geographical perspective. Overall, a nationwide LCC network has been formed with each individual LCC focusing on their own markets with limited overlap to avoid cut-throat competition. Spring Airlines has developed an advanced network supported by its core bases including Shanghai in East China, Shijiazhuang in North China, Shenyang in Northeast China and Shenzhen in South China. China United has developed a network radiating from Beijing. West Air and Lucky Air seem to be developing a hub-and-spoke network that contributes to the tourism industry in West China. The LCC network is affected by seasonal variations, especially for the routes to tourism destinations such as Haikou, Sanya and Xiamen. Hub cities, however, experience less seasonal impact. This research also finds that routes between 600 and 1800 km account for a large proportion of the LCC markets. Aviation policy, local government's subsidization and the expansion of the high-speed rail network have helped shape the landscape of China's LCC sector

Effect Assessment of Airflow Resistance by Local Airway Stenosis with 3D Printing Airway Model

Clinically noticing airway constriction can randomly cause small airway quickly closed and the surrouding airway occlusion happens subsequently. A phenomenon may happened called "avalanche phenomenon" inside airway [1]. But few study on how local airway stenosis affects the respiratory flow. Because the real local airway stenosis and its flow are still unable to be directly observed and measured. In this paper, narrow numerical model of the main and branched airway are established based on CT data of normal human airways. Then the trachea and bronchial branched airway constriction models are printed out on the 3D printer by PLA material. Finally, to measure airflow impedance of different airway models and analyze the impact of structural changes in the airway (shrink and narrow) airway impedance, we adopt independent research and development Forced Oscillation Technique(FOT). The test results preliminary show that the trachea stenosis has big effect on the airway viscous resistance (Rrs) and the elastic resistance (Xrs). The bronchial stenosis obviously increases the airway elastic resistance. This article provides a new method for the study on how local constriction affects the airflow inside airway in the future

Bitter Taste Receptor Agonist (Quinine) Induces Traction Force Reduction and Calcium Flux Increase in Airway Smooth Muscle Cells from Ovalbumin-Sensitized and Challenged Rats

Recently, bitter taste receptors (TAS2Rs) have been found in the lung, which can be stimulated with TAS2R agonist such as quinine to relax airway smooth muscle cells (ASMCs) via intracellular Ca2+ signaling generated from restricted phospholipase C activation. This provides a promising new therapy for asthma because enhanced contractility and impaired ability of relaxation of the ASMCs within the bronchial wall of asthmatic patients are thought to be ultimately responsible for airway constriction in asthma. However, further study is required for characterization of the effect of TAS2R agonist on the mechanical behaviors of ASMCs, in particular the traction force generation and associated mechanism in asthma model. Here, we sensitized Sprague Dawley rats with ovalbumin (OVA) for up to 12 weeks to simulate chronic asthma symptoms. Subsequently, we isolated ASMCs from these rats, and studied the traction force and intracellular Ca2+ signaling of the cells with/out treatment of quinine hydrochloride, a well-known TAS2R agonist. The results demonstrated that quinine hydrochloride relaxed the ASMC in a dose dependent manner. It also evoked dose-dependent increase of intracellular calcium ([Ca2+]i) in the ASMCs. Perhaps more importantly, the quinine-induced traction force reduction and Ca2+ flux increase were correlated. Taken together, our findings indicate that TAS2R agonists (e.g. quinine hydrochloride) could reduce the ability of ASMCs to generate traction force via activation of the intracellular calcium signaling, which may contribute as one of the mechanisms for TAS2R agonist-induced ASMC relaxation. This provides additional evidence to support TAS2R agonists as a new class of compounds with potential in treatment of chronic asthma

Stiffness of Substrate Influences the Distribution but not the Synthesis of Autophagosomes in Human Liver (LO2) Cells

Extracellular matrix (ECM) often becomes stiffer during tumor development, which not only gives the tumor's hardness feel but also actively contributes to the tumor formation. A good example is hepatocellular carcinoma (HCC) that usually develops within chronically stiffened liver tissues due to fibrosis and cirrhosis. On the other hand, HCC cells exhibit reduced autophagy in a malignancy dependent manner, suggesting autophagy is suppressed during tumor development. However, it is not known whether ECM stiffness would influence autophagy during tumor development. To investigate this issue, We cultured the human liver (LO2) cells that stably expressed autophagosome indicator LC3 on polydimethylsiloxane (PDMS) gels with stiffness varying from 11 to 1220 kPa. and on plastic cell culture dish as controls for up to 48h. We found that the total protein level of LC3-II in LO2 cells was not affected by the substrate stiffness. However the autophagosomes in LO2 cells cultured on the soft substrate (11 kPa PDMS gel) were localized and accumulated around the nucleus, while those on the stiff substrate (1220 kPa PDMS gel or plastic dish surface) were dispersed throughout the cytoplasmic space. Therefore, our data suggest that ECM stiffness may not directly synthesize nascent autophagosomes, but instead influence the location/translocation and ultimately distribution of autophagosomes in the cells

The DNA Methylome of Human Peripheral Blood Mononuclear Cells

Analysis across the genome of patterns of DNA methylation reveals a rich landscape of allele-specific epigenetic modification and consequent effects on allele-specific gene expression

A Systematic Analysis on DNA Methylation and the Expression of Both mRNA and microRNA in Bladder Cancer

Background: DNA methylation aberration and microRNA (miRNA) deregulation have been observed in many types of cancers. A systematic study of methylome and transcriptome in bladder urothelial carcinoma has never been reported. Methodology/Principal Findings: The DNA methylation was profiled by modified methylation-specific digital karyotyping (MMSDK) and the expression of mRNAs and miRNAs was analyzed by digital gene expression (DGE) sequencing in tumors and matched normal adjacent tissues obtained from 9 bladder urothelial carcinoma patients. We found that a set of significantly enriched pathways disrupted in bladder urothelial carcinoma primarily related to "neurogenesis" and "cell differentiation" by integrated analysis of -omics data. Furthermore, we identified an intriguing collection of cancer-related genes that were deregulated at the levels of DNA methylation and mRNA expression, and we validated several of these genes (HIC1, SLIT2, RASAL1, and KRT17) by Bisulfite Sequencing PCR and Reverse Transcription qPCR in a panel of 33 bladder cancer samples. Conclusions/Significance: We characterized the profiles between methylome and transcriptome in bladder urothelial carcinoma, identified a set of significantly enriched key pathways, and screened four aberrantly methylated and expressed genes. Conclusively, our findings shed light on a new avenue for basic bladder cancer research