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Rapid earthquake focal mechanism inversion using high-rate GPS velometers in sparse network

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Science China Earth Sciences 2015年第11期58卷 1970-1981,1页

作者： GUO AiZhi NI SiDao chen weiwen Jeffrey T.FREYMUELLER SHEN ZhiChao State Key Laboratory of Geodesy and Earth's Dynamics Institute of Geodesy and Geophysics Chinese Academy of Sciences School of Earth and Space Sciences University of Science and Technology of China Geophysical Institute University of Alaska Fairbanks

In this study, we demonstrate an approach for inverting earthquake source parameters based on high-rate global positioning system （GPS） velocity seismograms. The velocity records obtained from single-station GPS velocity solutions with broadcast ephemeris are used directly for earthquake source parameter inversion using the Cut and Paste method, without requiring conversion of the velocity records into displacement records. Taking the E1 Mayor-Cucapah earthquake as an example, GPS velocity records from 10 stations with reasonable azimuthal coverage provide earthquake source parameters very close to those from the Global centroid moment tensor （Global CMT） solution. In sparse network tests, robust source parameters with acceptable bias can be achieved with as few as three stations. When the number of stations is reduced to two, the bias in rake angle becomes appreciable, but the magnitude and strike estimations are still robust. The results of this study demonstrate that rapid and reliable estimation of earthquake source parameters can be obtained from GPS velocity data. These parameters could be used for early earthquake warning and shake map construction, because such GPS velocity records can be obtained in real time.

关键词： high-rate GPS velometer GPS velocity determination CAP method earthquake source parameters sparse network

Influences of AMY1 gene copy number and protein expression on salivary alpha-amylase activity before and after citric acid stimulation in splenic asthenia children

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Journal of Traditional Chinese Medicine 2015年第3期35卷 266-272页

作者： Yang Zemin Lin Jing chen Longhui Zhang Min Yang Xiaorong chen weiwen Department of Biochemistry and Molecular Biology School of Basic CoursesGuangdong Pharmaceutical University Pi-Wei Institute Guangzhou University of Chinese Medicine Pediatrics of Traditional Chinese Medicine Haizhu Maternal and Child health Hospital Clinical Laboratory the First Affiliated Hospital of Guangdong Pharmaceutical University

OBjECTIVE:To compare the correlations between salivary alpha-amylase(sAA) activity and amylase,alpha 1(salivary) gene(AMY1) copy number or its gene expression between splenic asthenia and healthy children,and investigate the reasons of attenuated sAA activity ratio before and after citric acid stimulation in splenic asthenia ***:Saliva samples from 20 splenic asthenia children and 29 healthy children were collected before and after citric acid ***1 copy number,sAA activity,and total sAA and glycosylated sAA contents were determined,and their correlations were ***:Although splenic asthenia and healthy children had no differences in AMY1 copy number,splenic asthenia children had positive correlations between AMY1 copy number and sAA activity before or after citric acid *** asthenia children had a higher sAA glycosylated proportion ratio and glycosylated sAA content ratio,while their total sAA content ratio and sAA activity ratio were lower compared with healthy *** glycosylated sAA content ratio was higher than the total sAA content ratio in both *** asthenia and healthy children had positive correlations between total sAA or glycosylated sAA content and sAA ***,the role played by glycosylated sAA content in sAA activity in healthy children increased after citric acid stimulation,while it decreased in splenic asthenia ***:Genetic factors like AMY1 copy number variations,and more importantly,sAA glycosylation abnormalities leading to attenuated sAA activity after citric acid stimulation,which were the main reasons of the attenuated sAA activity ratio in splenic asthenia children compared with healthy children.

关键词： Spleen deficiency Salivary alpha-amylase AMY1A protein,human Glycosylation Citric acid stimulation

Comparison of ground truth location of earthquake from InSAR and from ambient seismic noise: A case study of the 1998 Zhangbei earthquake

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Earthquake Science 2011年第2期24卷 239-247页

作者： Jun Xie Xiangfang Zeng weiwen chen Zhongwen Zhan CAS Key Laboratory of Geodynamical Laboratory Institute of Geodesy and Geophysics Wuhan 430077 China Mengcheng National Geophysical Observatory School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Seismological Laboratory California Institute of Technology Pasadena CA 91125 USA

Because ambient seismic noise provides estimated Green’s function （EGF） between two sites with high accuracy, Rayleigh wave propagation along the path connecting the two sites is well resolved. Therefore, earthquakes which are close to one seismic station can be well located with calibration extracting from EGF. We test two algorithms in locating the 1998 Zhangbei earthquake, one algorithm is waveform-based, and the other is traveltime-based. We first compute EGF between station ZHB （a station about 40 km away from the epicenter） and five IC/IRIS stations. With the waveform-based approach, we calculate 1D synthetic single-force Green’s functions between ZHB and other four stations, and obtain traveltime corrections by correlating synthetic Green’s functions with EGFs in period band of 10–30 s. Then we locate the earthquake by minimizing the differential travel times between observed earthquake waveform and the 1D synthetic earthquake waveforms computed with focal mechanism provided by Global CMT after traveltime correction from EGFs. This waveform-based approach yields a location which error is about 13 km away from the location observed with InSAR. With the traveltime-based approach, we begin with measuring group velocity from EGFs as well as group arrival time on observed earthquake waveforms, and then locate the earthquake by minimizing the difference between observed group arrival time and arrival time measured on EGFs. This traveltime-based approach yields accuracy of 3 km, Therefore it is feasible to achieve GT5 （ground truth location with accuracy 5 km） with ambient seismic noises. The less accuracy of the waveform-based approach was mainly caused by uncertainty of focal mechanism.

关键词： ambient seismic noise estimated Green’s function ground truth location Rayleigh wave

Preliminary study on aftershock decay rate of the 2013 Ms 7.0 Lushan earthquake

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Earthquake Science 2013年第3期26卷 185-190页

作者： Zhe Jia weiwen chen Risheng Chu Mengcheng National Geophysical Observatory School of Earth and Space SciencesUniversity of Science and Technology of China State Key Laboratory of Geodesy and Earth’s Dynamics Institute of Geodesy and GeophysicsCAS

We obtained a catalog of early aftershocks of the 2013 Lushan earthquake by examining waveform from a nearby station MDS which is 30.2 km far away from the epicenter, and then we analyzed the relation between aftershock rate and time. We used time-window ratio method to identify aftershocks from continuous waveform data and compare the result with the catalog provided by China Earthquake Networks Center （CENC）. As expected, a significant amount of earthquakes is missing in CENC catalog in the 24 h after the main shock. Moreover, we observed a steady seismicity rate of aftershocks nearly in the first 10,000 s before an obvious power-law decay of aftershock activity. We consider this distinct early stage which does not fit the Omori law with a constant p （p - 1） value as early aftershock deficiency （EAD）, as proposed by previous studies. Our study suggests that the main shock rupture process is different from aftershocks＇ processes, and EAD can vary in different cases as compared to earthquakes of strike-slip mechanism in California.

关键词： Aftershock rate Early aftershock deficiencyOmori law Earthquake rupture

A study on the uncertainties of the centroid depth of the 2013 Lushan earthquake from teleseimic body wave data

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Earthquake Science 2013年第3期26卷 161-168页

作者： weiwen chen Decai Wang Shengji Wei Mengcheng National Geophysical Observatory School of Earth and Space SciencesUniversity of Science and Technology of China Seismological Laboratory California Institute of TechnologyPasadenaCA 91125USA

Centroid depth of earthquakes is essential for seismic hazard mitigation. But, various studies provided different solutions for the centroid depth of the damaging 2013 Lushan earthquake, thus hindering further studies of the earthquake processes. To resolve its centroid depth and assess the uncertainties, we apply the teleseismic cut and paste method to invert for centroid depth with teleseismic body waves in the epicentral distance of 300-90~. We performed the inversion for P waves only as well the case of both P and SH waves and found that both cases lead to depth solutions with difference less than 0.5 km. We also investigated the effects on depth inversion from azimuth gap of seismic stations, source duration, and comer fre- quency of filter. These various tests show that even azi- muthal distribution of seismic stations is helpful for accurate depth inversion. It is also found that estimate of centroid depth is sensitive to source duration. Moreover, the depth is biased to larger values when corner frequency of low-pass filter is very low. The uncertainty in the velocity model can also generate some error in the depth estimation （- 1.0 km）.With all the above factors consid- ered, the centroid depth of Lushan earthquake is proposed to be around 12 km, with uncertainty about 2 km.

关键词： Lushan earthquake Centroid depth Teleseismic body wave Cut and paste

FoxO directly regulates the expression of TOR/S6K and vitellogenin to modulate the fecundity of the brown planthopper

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Science China(Life Sciences) 2021年第1期64卷 133-143页

作者： Yi Dong weiwen chen Kui Kang Rui Pang Yipei Dong Kai Liu Wenqing Zhang State Key Laboratory of Biocontrol School of Life SciencesSun Yat-Sen UniversityGuangzhou510275China

As a conserved transcription factor,FoxO plays a crucial role in multiple physiological processes in vivo,including stress resistance,longevity,growth and *** studies on FoxO have focused on human,mouse,Drosophila melanogaster and Caenorhabditis elegans,while there are few reports on agricultural pests and little is known about how FoxO modulates insect *** Asia,the brown planthopper(BPH)Nilaparvata lugens(St?l)is one of the most serious pests in rice production and high fecundity is the basis of the outbreak of ***,using the genome-wide ChIP-seq of NlFoxO in BPH,we found that NlFoxO binds to the promoters of ribosomal protein S6 kinase(NlS6K)and serine/threonine-protein kinase mTOR(NlTOR)and increases their expression *** also found that NlFoxO directly binds to the exon of vitellogenin(NlVg)and has a specific inhibitory effect on its *** addition,the number of eggs laid and their hatching rate decreased significantly after injection of NlFoxO double-stranded RNA into BPH *** findings provide direct evidence that FoxO modulates insect fecundity through binding to the promoters of NlS6K,NlTOR and the exon of NlVg and affecting their gene expression in the Vg network.

关键词： FoxO ChIP-seq Nilaparvata lugens fecundity vitellogenin(Vg) bind

Effects of sedimentary layer on earthquake source modeling from geodetic inversion

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Earthquake Science 2011年第2期24卷 221-227页

作者： weiwen chen Sidao Ni Shengji Wei Zhenjie Wang Jun Xie Mengcheng National Geophysical Observatory University of Science and Technology of China Hefei 230026 China CAS Key Laboratory of Geodynamical Geodesy Institute of Geodesy and Geophysics Wuhan 430077 China Seismological Laboratory California Institute of Technology Pasadena CA 91125 USA

Ground deformation as observed with GPS or InSAR has been broadly inverted in constraining source parameter of earthquakes. However, for earthquakes occurring beneath sedimentary basins, the very slow sub-surface shear velocity （v S , down to 200 m/s） may cause substantial bias to earthquake source inversion if simple crustal models are used. For Bohai basin, Sichuan basin and rock-sites, we test effects of sub-surface shear velocity structure on ground deformation, and find that up to a factor of 2 overestimate of seismic moment could be generated by the basin structures. Therefore, the very slow sub-surface velocity has to be taken into account before accurate source inversion can be applied.

关键词： sedimentary layer ground deformation InSAR GPS

Population density modulates insect progenitive plasticity through the regulation of dopamine biosynthesis

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Insect Science 2022年第6期29卷 1773-1789页

作者： Kai Liu Longyu Yuan Lei Yue weiwen chen Kui Kang Jun Lv Wenqing Zhang Rui Pang State Key Laboratory of Biocontrol School of Life SciencesSun Yat-sen UniversityGuangzhouChina Guangdong Provincial Key Laboratory of Microbial Safety and Health State Key Laboratory of Applied Microbiology Southern ChinaInstitute of MicrobiologyGuangdong Academy of SciencesGuangzhouChina Innovative Institute for Plant Health College of Agriculture and BiologyZhongkai Universityof Agriculture and EngineeringGuangzhouChina

Insect fecundity is a quantitative phenotype strongly affected by genotypes and the ***,interactions between genotypes and environmental factors in modulating insect fecundity remain largely *** study investigated the im-pact of population density on the fecundity of Nilaparvata lugens(brown planthopper;BPH)carrying homozygous high-(HFG)or low-(LFG)fecundity homozygous *** low population densities,the fecundity and population growth rate of both genotypes showed similar increasing trends across generations,while the trends between HFG and LFG under high population densities were *** a combination of temporal analysis and weighted gene co-expression network analyses on RNA-seq data of HFG and LFG under low and high population densities in the lst,3rd,and 5th gener-ations,we identified 2 gene modules that were associated with these density-dependent progenitive *** pathways related to the neural system were simultaneously enriched by the 2 gene ***,Nlpale,which encodes a tyrosine hydroxy-lase,was identified as a key *** RNA interference of this gene and manipulation of its downstream product dopamine significantly affected the basic and density-dependent progenitive phenotypes of *** findings indicated that dopamine biosynthesis is the key regulatory factor that determines fecundity in response to density changes in dif-ferent BPH ***,this study provides insights into the interaction of a typical environmental factor and insect genotype during the process of population regulation.

关键词： dopamine biosynthesis fecundity genotype Nilaparvata lugens popula-tiondensity

Differential expression of immune-related genes between healthy volunteers and type 2 diabetic patients with spleen-deficiency pattern

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Journal of Traditional Chinese Medicine 2015年第6期35卷 646-652页

作者： chen Longhui Yang Zemin chen weiwen Li Ruliu Lin Chuanquan Guan Lihua Zhu Zhangzhi chen Ruifang Li Saimei Zhao Lingbo Zeng Jinhao Wang Jianhua Pi-wei Institute Guangzhou University of Chinese Medicine School of Basic Courses Guangdong Pharmaceutical University the First Affiliated Hospital of Guangzhou University of Chinese Medicine Clinical Medical College of Acupuncture Moxibustion and RehabilitationGuangzhou University of Chinese Medicine

OBJECTIVE: To investigate the clinical differentiation of spleen-deficiency pattern(SDP), a group of symptoms and signs defined in terms of Traditional Chinese Medicine for its clinical ***: Peripheral venous blood(> 3 m L) was collected from each of six type 2 diabetes mellitus(T2DM)-SDP patients and six healthy volunteers. After the isolation of peripheral white blood cells(PWBCs), total RNA was extracted, and quality control was performed on all RNA samples. Microarray experiments were conducted using the Agilent human whole genome gene chip, and genes demonstrating differential expression were screened. Bioinformatics analysis was conducted on these genes using several online ***: We screened a total of 175 differentially expressed genes(DEGs), of which 111(63%) were down-regulated and 64(37%) were up-regulated in T2DM-SDP patients compared with healthy controls. Among the 175 genes, 158 had biological function annotations: 46(29%) were directly related to an individual's immune regulation or response, 25(16%) were associated with substance and energy metabolism of PWBCs which could also indirectly influence immunity, and the remaining87(55%) were involved in a variety of PWBC biological processes that might eventually influence the immune function. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that the DEGs were predominantly enriched in seven immune-related pathways. Hierarchical cluster analysis identified gene expression patterns that were distinguishable between the two study ***: Our results suggest that T2DM-SDP patients experience significant hypoimmunity and/or immune dysfunctions, and possess a specific gene expression profile. These findings offer new insights into SDP and the clinical pattern differentiation of T2DM-SDP.

关键词： Diabetes mellitus, Type 2 Immunity Metabolism Leukocytes Oligonucleotide array se-quence analysis Spleen-deficiency pattern