As a companion paper to Zhou RX et al.(2020),this study describes application of the automatic detection and analysis module to identify all the tweek atmospherics detectible in the WHU ELF/VLF receiver data collected...As a companion paper to Zhou RX et al.(2020),this study describes application of the automatic detection and analysis module to identify all the tweek atmospherics detectible in the WHU ELF/VLF receiver data collected at Suizhou station during the period of 3 February through 29 February 2016.Detailed analysis of the identified low-latitude tweek events reveals that the occurrence rate varies considerably—from 800 to 6000 tweeks per day,and exhibits a strong diurnal and local time dependence,the peak occurring before local midnight.The diurnal variation of identified tweeks was similar to that of the lightning data obtained by the World-Wide Lightning Location Network(WWLLN)..Estimates of the propagation distance and ionospheric reflection height of tweek atmospherics suggest that the majority(~92%)of the low latitude tweeks originate from the lightning activity within a radius of 4000 km and that they are very likely to reflect from the lower ionospheric D-region at the height range of 75–85 km.At these lower ionospheric reflection altitudes,~74%of the corresponding electron densities from the tweek spectral measurements are within 24.5–27.5 cm^-3.The daily variation of estimated D-region electron densities in the considered period(February 2016)also exhibits a small overall increasing trend from early to later in the month.展开更多
As a dispersive wave mode produced by lightning strokes, tweek atmospherics provide important hints of lower ionospheric(i.e., D-region) electron density. Based on data accumulation from the WHU ELF/VLF receiver syste...As a dispersive wave mode produced by lightning strokes, tweek atmospherics provide important hints of lower ionospheric(i.e., D-region) electron density. Based on data accumulation from the WHU ELF/VLF receiver system, we develop an automatic detection module in terms of the maximum-entropy-spectral-estimation(MESE) method to identify unambiguous instances of low latitude tweeks.We justify the feasibility of our procedure through a detailed analysis of the data observed at the Suizhou Station(31.57°N, 113.32°E) on17 February 2016. A total of 3961 tweeks were registered by visual inspection;the automatic detection method captured 4342 tweeks, of which 3361 were correct ones, producing a correctness percentage of 77.4%(= 3361/4342) and a false alarm rate of 22.6%(= 981/4342).A Short-Time Fourier Transformation(STFT) was also applied to trace the power spectral profiles of identified tweeks and to evaluate the tweek propagation distance. It is found that the fitting accuracy of the frequency–time curve and the relative difference of propagation distance between the two methods through the slope and through the intercept can be used to further improve the accuracy of automatic tweek identification. We suggest that our automatic tweek detection and analysis method therefore supplies a valuable means to investigate features of low latitude tweek atmospherics and associated ionospheric parameters comprehensively.展开更多
A set of closed-loop normative standards of PDCA(planning-implementing-checking-improvement) of the quality management system is applied to promote the standardization, normalization and institutionalization of grass-...A set of closed-loop normative standards of PDCA(planning-implementing-checking-improvement) of the quality management system is applied to promote the standardization, normalization and institutionalization of grass-roots meteorological observations, further improve the service availability and timely rate of data, and improve the quality and efficiency of meteorological observations.展开更多
An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, an...An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, and the information current is only microamp, so the withstand voltage to lightning electromagnetic pulse is extremely low. In this paper, the negative impact of lightning and static electricity on the computer room of an electronic information system was analyzed firstly, and then the design for the lightning protection of the computer room was discussed.展开更多
Comprehensive identification of conditionally essential genes requires efficient tools for generating high-density transposon libraries that, ideally, can be analysed using next-generation sequencing methods such as T...Comprehensive identification of conditionally essential genes requires efficient tools for generating high-density transposon libraries that, ideally, can be analysed using next-generation sequencing methods such as Transposon Directed Insertion-site Sequencing (TraDIS). The Himar1 (mariner) transposon is ideal for generating near-saturating mutant libraries, especially in AT-rich chromosomes, as the requirement for integration is a TA dinucleotide, and this transposon has been used for mutagenesis of a wide variety of bacteria. However, plasmids for mariner delivery do not necessarily work well in all bacteria. In particular, there are limited tools for functional genomic analysis of Pasteurellaceae species of major veterinary importance, such as swine and cattle pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida, respectively. Here, we developed plasmids, pTsodCPC9 and pTlacPC9 (differing only in the promoter driving expression of the transposase gene), that allow delivery of mariner into both these pathogens, but which should also be applicable to a wider range of bacteria. Using the pTlacPC9 vector, we have generated, for the first time, saturating mariner mutant libraries in both A. pleuropneumoniae and P. multocida that showed a near random distribution of insertions around the respective chromosomes as detected by TraDIS. A preliminary screen of 5000 mutants each identified 8 and 14 genes, respectively, that are required for growth under anaerobic conditions. Future high-throughput screening of the generated libraries will facilitate identification of mutants required for growth under different conditions, including in vivo, highlighting key virulence factors and pathways that can be exploited for development of novel therapeutics and vaccines.展开更多
基金supported by the National Natural Science Foundation of China (Grants Nos. 41674163, 41474141, 41204120,41304127, 41304130, and 41574160)the Projects funded by China Postdoctoral Science Foundation (Grants Nos. 2013M542051, 2014T70732)+2 种基金the Hubei Province Natural Science Excellent Youth Foundation (2016CFA044)The project Supported by the Specialized Research Fund for State Key Laboratoriesthe 985 funded project of School of Electronic information, Wuhan University。
文摘As a companion paper to Zhou RX et al.(2020),this study describes application of the automatic detection and analysis module to identify all the tweek atmospherics detectible in the WHU ELF/VLF receiver data collected at Suizhou station during the period of 3 February through 29 February 2016.Detailed analysis of the identified low-latitude tweek events reveals that the occurrence rate varies considerably—from 800 to 6000 tweeks per day,and exhibits a strong diurnal and local time dependence,the peak occurring before local midnight.The diurnal variation of identified tweeks was similar to that of the lightning data obtained by the World-Wide Lightning Location Network(WWLLN)..Estimates of the propagation distance and ionospheric reflection height of tweek atmospherics suggest that the majority(~92%)of the low latitude tweeks originate from the lightning activity within a radius of 4000 km and that they are very likely to reflect from the lower ionospheric D-region at the height range of 75–85 km.At these lower ionospheric reflection altitudes,~74%of the corresponding electron densities from the tweek spectral measurements are within 24.5–27.5 cm^-3.The daily variation of estimated D-region electron densities in the considered period(February 2016)also exhibits a small overall increasing trend from early to later in the month.
基金supported by the National Natural Science Foundation of China (Grants Nos. 41674163, 41474141, 41204120, 41304127, 41304130, and 41574160)the Projects funded by China Postdoctoral Science Foundation (Grants Nos. 2013M542051, 2014T70732)+2 种基金the Hubei Province Natural Science Excellent Youth Foundation (2016CFA044)the Project Supported by the Specialized Research Fund for State Key Laboratoriesthe 985 funded project of School of Electronic information, Wuhan University
文摘As a dispersive wave mode produced by lightning strokes, tweek atmospherics provide important hints of lower ionospheric(i.e., D-region) electron density. Based on data accumulation from the WHU ELF/VLF receiver system, we develop an automatic detection module in terms of the maximum-entropy-spectral-estimation(MESE) method to identify unambiguous instances of low latitude tweeks.We justify the feasibility of our procedure through a detailed analysis of the data observed at the Suizhou Station(31.57°N, 113.32°E) on17 February 2016. A total of 3961 tweeks were registered by visual inspection;the automatic detection method captured 4342 tweeks, of which 3361 were correct ones, producing a correctness percentage of 77.4%(= 3361/4342) and a false alarm rate of 22.6%(= 981/4342).A Short-Time Fourier Transformation(STFT) was also applied to trace the power spectral profiles of identified tweeks and to evaluate the tweek propagation distance. It is found that the fitting accuracy of the frequency–time curve and the relative difference of propagation distance between the two methods through the slope and through the intercept can be used to further improve the accuracy of automatic tweek identification. We suggest that our automatic tweek detection and analysis method therefore supplies a valuable means to investigate features of low latitude tweek atmospherics and associated ionospheric parameters comprehensively.
文摘A set of closed-loop normative standards of PDCA(planning-implementing-checking-improvement) of the quality management system is applied to promote the standardization, normalization and institutionalization of grass-roots meteorological observations, further improve the service availability and timely rate of data, and improve the quality and efficiency of meteorological observations.
文摘An electronic information system is composed of multiple groups of components. With the improvement of technology, its accuracy is getting higher and higher. The voltage during normal operation is only a few volts, and the information current is only microamp, so the withstand voltage to lightning electromagnetic pulse is extremely low. In this paper, the negative impact of lightning and static electricity on the computer room of an electronic information system was analyzed firstly, and then the design for the lightning protection of the computer room was discussed.
基金This work was supported by a Longer and Larger(LoLa)grant from the Biotechnology and Biological Sciences Research Council(BBSRC,grant numbers BB/G020744/1,BB/G019177/1,BB/G019274/1 and BB/G018553/1)the UK Department for Environment,Food and Rural Affairs and Zoetis awarded to the Bacterial Respiratory Diseases of Pigs-1 Technology(BRaDP1T)consortium.Funding for LZ was provided by the BBSRC(grant number BB/C508193/1)The funders had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
文摘Comprehensive identification of conditionally essential genes requires efficient tools for generating high-density transposon libraries that, ideally, can be analysed using next-generation sequencing methods such as Transposon Directed Insertion-site Sequencing (TraDIS). The Himar1 (mariner) transposon is ideal for generating near-saturating mutant libraries, especially in AT-rich chromosomes, as the requirement for integration is a TA dinucleotide, and this transposon has been used for mutagenesis of a wide variety of bacteria. However, plasmids for mariner delivery do not necessarily work well in all bacteria. In particular, there are limited tools for functional genomic analysis of Pasteurellaceae species of major veterinary importance, such as swine and cattle pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida, respectively. Here, we developed plasmids, pTsodCPC9 and pTlacPC9 (differing only in the promoter driving expression of the transposase gene), that allow delivery of mariner into both these pathogens, but which should also be applicable to a wider range of bacteria. Using the pTlacPC9 vector, we have generated, for the first time, saturating mariner mutant libraries in both A. pleuropneumoniae and P. multocida that showed a near random distribution of insertions around the respective chromosomes as detected by TraDIS. A preliminary screen of 5000 mutants each identified 8 and 14 genes, respectively, that are required for growth under anaerobic conditions. Future high-throughput screening of the generated libraries will facilitate identification of mutants required for growth under different conditions, including in vivo, highlighting key virulence factors and pathways that can be exploited for development of novel therapeutics and vaccines.
