The signal transduction system of microorganisms helps them adapt to changes in their complex living environment.Two-component system(TCS)is a representative signal transduction system that plays a crucial role in reg...The signal transduction system of microorganisms helps them adapt to changes in their complex living environment.Two-component system(TCS)is a representative signal transduction system that plays a crucial role in regulating cellular communication and secondary metabolism.In Gram-negative bacteria,an unorthodox TCS consist-ing of histidine kinase protein GacS(initially called LemA)and response regulatory protein GacA is widespread.It mainly regulates various physiological activities and behaviors of bacteria,such as quorum sensing,secondary metabolism,biofilm formation and motility,through the Gac/Rsm(Regulator of secondary metabolism)signaling cascade pathway.The global regulatory ability of GacS/GacA in cell physiological activities makes it a potential research entry point for developing natural products and addressing antibiotic resistance.In this review,we summarize the progress of research on GacS/GacA from various perspectives,including the reaction mechanism,related regulatory pathways,main functions and GacS/GacA-mediated applications.Hopefully,this review will facilitate further research on GacS/GacA and promote its application in regulating secondary metabolism and as a therapeutic target.展开更多
Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Grav...Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Gravity Anomaly(BGA)map of WGM2012,the feasibility of replacing in-situ gravity surveying in China is investigated.For leveling application,that is to evaluate the accuracy of WGM2012 in China.Because WGM2012 is organized with a standard rectangle grid,two interpolation methods,bilinear interpolating and Inverse Distance Weighted(IDW)interpolating,are proposed.Four sample areas in China,i.e.,Hanzhong,Chengdu,Linzhi and Shantou,are selected to evaluate the systems bias and precision of WGM2012.Numerical results show the average system bias of WGM2012 BGA in west China is about-100.1 mGal(1 mGal=10^(-5) m/s^(2))and the standard deviation is about 30.7 mGal.Tests in Shantou indicate the system bias in plain areas is about-130.4 mGal and standard deviation is about 6.8 mGal.All these experiments means the accuracy of WGM2012 is limited in high mountain areas of western China,but in plain areas,such as Shantou,WGM2012 BGA map is quite good for most leveling applications after calibrating the system bias.展开更多
以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲...以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲线;进而利用LiDAR深度梯度影像改进模型演化的外力,得到了改进的测地线活动轮廓(improved geodesic active contour,IGAC)模型。仿真试验表明,采用IGAC模型,可抑制弱边界泄漏,并提高建筑物边界提取的完整性和形状精确度。展开更多
基金supported by the National Natural Science Foundation of China(42176108,31870023)the Young Taishan Scholars Program of Shandong Province(tsqn202103029)the Fundamental Research Funds for the Central Universities(201941009).
文摘The signal transduction system of microorganisms helps them adapt to changes in their complex living environment.Two-component system(TCS)is a representative signal transduction system that plays a crucial role in regulating cellular communication and secondary metabolism.In Gram-negative bacteria,an unorthodox TCS consist-ing of histidine kinase protein GacS(initially called LemA)and response regulatory protein GacA is widespread.It mainly regulates various physiological activities and behaviors of bacteria,such as quorum sensing,secondary metabolism,biofilm formation and motility,through the Gac/Rsm(Regulator of secondary metabolism)signaling cascade pathway.The global regulatory ability of GacS/GacA in cell physiological activities makes it a potential research entry point for developing natural products and addressing antibiotic resistance.In this review,we summarize the progress of research on GacS/GacA from various perspectives,including the reaction mechanism,related regulatory pathways,main functions and GacS/GacA-mediated applications.Hopefully,this review will facilitate further research on GacS/GacA and promote its application in regulating secondary metabolism and as a therapeutic target.
基金“Wings of Quality”Program of QICS(No.2020-zlzy-015)。
文摘Gravity Anomaly Correction(GAC)is a very important term in leveling data processing.In most cases,it is troublesome for field surveyors to measure gravity when leveling.In this paper,based on the complete Bouguer Gravity Anomaly(BGA)map of WGM2012,the feasibility of replacing in-situ gravity surveying in China is investigated.For leveling application,that is to evaluate the accuracy of WGM2012 in China.Because WGM2012 is organized with a standard rectangle grid,two interpolation methods,bilinear interpolating and Inverse Distance Weighted(IDW)interpolating,are proposed.Four sample areas in China,i.e.,Hanzhong,Chengdu,Linzhi and Shantou,are selected to evaluate the systems bias and precision of WGM2012.Numerical results show the average system bias of WGM2012 BGA in west China is about-100.1 mGal(1 mGal=10^(-5) m/s^(2))and the standard deviation is about 30.7 mGal.Tests in Shantou indicate the system bias in plain areas is about-130.4 mGal and standard deviation is about 6.8 mGal.All these experiments means the accuracy of WGM2012 is limited in high mountain areas of western China,but in plain areas,such as Shantou,WGM2012 BGA map is quite good for most leveling applications after calibrating the system bias.
文摘以自动生成测地线活动轮廓(geodesic active contour,GAC)模型的初始曲线及改进其外力为出发点,提出一种基于LiDAR点云和随机影像数据,利用改进的GAC模型进行建筑物边界提取的方案。首先利用形态学交替序贯滤波自动获得模型演化的初始曲线;进而利用LiDAR深度梯度影像改进模型演化的外力,得到了改进的测地线活动轮廓(improved geodesic active contour,IGAC)模型。仿真试验表明,采用IGAC模型,可抑制弱边界泄漏,并提高建筑物边界提取的完整性和形状精确度。
