Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has...Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.展开更多
Earthquake is a violent and irregular ground motion that can severely damage structures. In this paper we subject a single-degree-of-freedom system, consisting of spring and damper, to an earthquake excitation, and me...Earthquake is a violent and irregular ground motion that can severely damage structures. In this paper we subject a single-degree-of-freedom system, consisting of spring and damper, to an earthquake excitation, and meanwhile investigate the response behavior from a novel theory about the dynamical system, by viewing the time-varying signum function of It can reflect the characteristic property of each earthquake through and the second component of f, where is a time-sampling record of the acceleration of a ground motion. The barcode is formed by plotting with respect to time. We analyze the complex jumping behavior in a barcode and an essential property of a high percentage occupation of the first set of dis-connectivity in the barcode from four strong earthquake records: 1940 El Centro earthquake, 1989 Loma earthquake, and two records of 1999 Chi-Chi earthquake. Through the comparisons of four earthquakes, we can observe that strong earthquake leads to large percentage of the first set of dis-connectivity.展开更多
A dual-bias differential method is presented for increasing the detection range of a ternary barcode detection system. The system is provided with a second differential delay circuit with bias control to process optim...A dual-bias differential method is presented for increasing the detection range of a ternary barcode detection system. The system is provided with a second differential delay circuit with bias control to process optimally gray signals by lowering their averaged level using a clamping circuit. This is added to the primary conventional differential delay circuit without bias control and a comparator to process optimally black signals based on the envelope-differential fixed-period delay (EDFPD) detection technique. This method enables the system to detect over a longer range at high speeds while being capable of handling a large amount of information. The estimate results of gray and white code widths against the clamp bias made through the dynamic operation simulation of a differential circuit using SPICE were nearly consistent with the experimental results. Thereby we can conclude that the dynamic simulation is effective for estimation of an optimum clamp bias voltage. It was confirmed that the detection range of the system with a clamp bias voltage of ?0.4 V for a minimum bar width W = 0.25 mm was 1.4 times that of the conventional EDFPD detection technique. In addition, the system operated at a maximum scanning speed of 7.7 times that of conventional CCD cameras under the practical detection range. The system with clamp bias control is expected to enable the real-time identification of goods on production lines and in automated warehouses.展开更多
Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam distr...Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one year.Deoxyribonucleic acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic analysis.Results:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus Neophlebotomus.Mitochondrial COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different species.Conclusions:The Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on sandflies.The current study tried to fill the void and also report a new sandfly species.展开更多
The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were c...The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.展开更多
Members of the Goliathus group in the order Coleoptera, family Scarabaeidae and the sub-family Cetoniidae is one among essential ecological insects worldwide with scanty documentation in Tanzania. The country was amon...Members of the Goliathus group in the order Coleoptera, family Scarabaeidae and the sub-family Cetoniidae is one among essential ecological insects worldwide with scanty documentation in Tanzania. The country was among the first point of collection of the specimen by Moser (1909) but subsequent attempts to locate and collect the specimen were unsuccessful possibly due to changed habitat and behaviour of Goliathus. Much of published work about the insect are based on the morphological characteristics of collected specimen which led to designation of six major species namely;Goliathus goliatus, G. cacicus, G. regius, G. albosignatus, G. orientalis and G. usambarensis, the last two being considered to exist in Tanzania. The current study reports on successful identification of habitats using biological cues and subsequently collected several Goliathus specimen that had been difficult to trace for more than a century. New insights into correct identity of the species by using a combination of morphological and molecular techniques have been set. The study has resolved that only one species, Goliathus orientalis with five sub-species exist in Tanzania.展开更多
The introduction of invasive insect pests across national borders has become a major concern in crop production. Accordingly, national plant protection organizations are challenge to reinforce their monitoring strateg...The introduction of invasive insect pests across national borders has become a major concern in crop production. Accordingly, national plant protection organizations are challenge to reinforce their monitoring strategies, which are hampered by the weight and size of inspection equipment, as well as the taxonomic extensiveness of interrupted species. Moreover, some insect pests that impede farmer productivity and profitability are difficult for researchers to address on time due to a lack of appropriate plant protection measures. Farmers’ reliance on synthetic pesticides and biocontrol agents has resulted in major economic and environmental ramifications. DNA barcoding is a novel technology that has the potential to improve Integrated Pest Management decision-making, which is dependent on the ability to correctly identify pest and beneficial organisms. This is due to some natural traits such as phenology or pesticide susceptibility browbeaten by IPM strategies to avert pest establishment. Specifically, Deoxyribonucleic acid (DNA) sequence information was applied effectively for the identification of some micro-organisms. This technology, DNA barcoding, allows for the identification of insect species by using short, standardized gene sequences. DNA barcoding is basically based on repeatable and accessible technique that allows for the mechanisation or automation of species discrimination. This technique bridges the taxonomic bio-security gap and meets the International Plant Protection Convention diagnostic standards for insect identification. This review therefore discusses DNA barcoding as a technique for insect pests’ identification and its potential application for crop protection.展开更多
Background:Spermacoce pusilla Wallich(S.pusilla)is widely used in Guangdong province of China.It has valuable medicinal value in treating trauma,fractures,carbuncle,swelling,and poisonous snake bites.Method:The presen...Background:Spermacoce pusilla Wallich(S.pusilla)is widely used in Guangdong province of China.It has valuable medicinal value in treating trauma,fractures,carbuncle,swelling,and poisonous snake bites.Method:The present study was carried out to provide a scientific basis for the identification and authenticity of S.pusilla with the help of pharmacognostical parameters,which has not been done before.In this study,a series of related identification information such as source,character,microscopic observation,physical and chemical reaction,and molecular markers were employed to establish accurate,comprehensive pharmacognostic identification information of S.pusilla.Results:The study provided some basic data regarding the genuine crude drug.The identification efficiency of ITS sequences obtained in this study is high,the psbA-trnH sequence was obtained from S.pusilla and sequenced for the first time in this study.Conclusion:In this study,traditional pharmacognosy identification and molecular marker identification of S.pusilla in the Guangdong region were carried out,and a systematic and comprehensive pharmacognosy identification information system was established.展开更多
The genus Pyrrosia belongs to the family Polypodiaceae and are medium-sized epiphytic ferns,where the dried leaves of Pyrrosia lingua,Pyrrosia sheareri,Pyrrosia lanceolata,and Pyrrosia calvata are commonly used in med...The genus Pyrrosia belongs to the family Polypodiaceae and are medium-sized epiphytic ferns,where the dried leaves of Pyrrosia lingua,Pyrrosia sheareri,Pyrrosia lanceolata,and Pyrrosia calvata are commonly used in medicinal practice.In this study,the authenticity of the collected medicinal plant samples of Shiwei was identified with the help of DNA barcoding technology using the internal transcribed spacer 2(ITS2)as the identifying sequence.The experimental samples were analyzed using the basic local alignment search tool(BLAST)and the authenticity of the samples was further verified with the results of similarity comparison.The results proved that the sequences of the experimentally collected samples of Pyrrosia lingua,Pyrrosia sheareri,Pyrrosia lanceolata,and Pyrrosia calvata had a similarity of more than 97%when compared with the corresponding sequences that were uploaded on the Internet.展开更多
Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the perfo...Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China. Methods Seventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes (motK, rbcL, and ITS) were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment (PWG) distance, and Tree-Building were tested for discrimination power. Results The primer universality of all the three markers was high. Except in the case of ITS for Hemerocollis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method.展开更多
This letter presents a method for digital image watermarking for copyright protection. This technique produces a watermarked image that closely retains the quality of the original host image while concurrently survivi...This letter presents a method for digital image watermarking for copyright protection. This technique produces a watermarked image that closely retains the quality of the original host image while concurrently surviving various image processing operations such as lowpass/highpass filtering, lossy JPEG compression, and cropping. This image watermarking algorithm takes full advantage of permutation and 2-D barcode (PDF417). The actual watermark embedding in spatial domain is followed using permutated image for improving the resistance to image cropping. Much higher watermark robustness is obtainable via a simple forward error correction technique, which is the main feature of PDF417 codes. Additional features of this technique include the easy determination of the existence of the watermark and that the watermark verification procedure does not need the original host image. The experimental results demonstrate its effectiveness.展开更多
Objective To provide a feasible and cost-effective next-generation sequencing (NGS) method for accurate identification of viral pathogens in clinical specimens, because enormous limitations impede the clinical use o...Objective To provide a feasible and cost-effective next-generation sequencing (NGS) method for accurate identification of viral pathogens in clinical specimens, because enormous limitations impede the clinical use of common NGS, such as high cost, complicated procedures, tremendous data analysis, and high background noise in clinical samples. Methods Viruses from cell culture materials or clinical specimens were identified following an improved NGS procedure: reduction of background noise by sample preprocessing, viral enrichment by barcoded oligonucleotide (random hexamer or non-ribosomal hexanucleotide) primer-based amplification, fragmentation-free library construction and sequencing of one-tube mixtures, as well as rapid data analysis using an in-house pipeline. Results NGS data demonstrated that both barcoded primer sets were useful to simultaneously capture multiple viral pathogens in cell culture materials or clinical specimens and verified that hexanucleotide primers captured as many viral sequences as hexamers did. Moreover, direct testing of clinical specimens using this improved hexanucleotide primer-based NGS approach provided further detailed genotypes of enteroviruses causing hand, foot, and mouth disease (HFMD) and identified other potential viruses or differentiated misdiagnosis events. Conclusion The improved barcoded oligonucleotide primer-based NGS approach is simplified, time saving, cost effective, and appropriate for direct identification of viral pathogens in clinical practice.展开更多
[Objectives]The most common gene fragment used in animal DNA barcode technology is COI,but it is not necessarily suitable for all species.This study was conducted to screen genes suitable for the DNA barcode of sea sn...[Objectives]The most common gene fragment used in animal DNA barcode technology is COI,but it is not necessarily suitable for all species.This study was conducted to screen genes suitable for the DNA barcode of sea snakes.[Methods]All COI and cytb gene sequences on GenBank were searched and downloaded.After the comparison with Mega software,clustering trees of MrBayes system were established.[Results]Interspecies distances were greater than intraspecies distances for the two genes.The topological structures of their molecular hierarchical clustering trees were clear,and the support rates were high.[Conclusions]Therefore,it is concluded that not the DNA barcode of each species must be gene COI.Cytb is more suitable in terms of the mitochondrial gene of sea snakes.展开更多
Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is k...Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is known as DNA barcoding—will choose one or several standard loci which can be sequenced and compared to differentiate between species. In this research, the ITS, matK, and trnH-psbA sequences were evaluated for the molecular identification of seven F. carica genotypes, generating complete sequences for the first two loci, but unable to produce bidirectional sequences by using the trnH-psbA sequence. The ITS sequence presented the highest variation rates, while the phylogeny constructed with the matK sequence obtained the highest percentage of solved monophyletic groups. Through Pearson’s correlation analysis, it was possible to determine the existence of a significant correlation between the ITS region and psbA-trnH, and the matK and psbA-trnH sequences, but not between ITS and matK. The phylogenies constructed with the ITS + matK barcodes and ITS + matK + psbA-trnH presented the highest percentage for resolution. However, considering the cost efficiency and the facilitated recovery by using PCR, the matK + ITS combination is recommended.展开更多
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD35B04)
文摘Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.
文摘Earthquake is a violent and irregular ground motion that can severely damage structures. In this paper we subject a single-degree-of-freedom system, consisting of spring and damper, to an earthquake excitation, and meanwhile investigate the response behavior from a novel theory about the dynamical system, by viewing the time-varying signum function of It can reflect the characteristic property of each earthquake through and the second component of f, where is a time-sampling record of the acceleration of a ground motion. The barcode is formed by plotting with respect to time. We analyze the complex jumping behavior in a barcode and an essential property of a high percentage occupation of the first set of dis-connectivity in the barcode from four strong earthquake records: 1940 El Centro earthquake, 1989 Loma earthquake, and two records of 1999 Chi-Chi earthquake. Through the comparisons of four earthquakes, we can observe that strong earthquake leads to large percentage of the first set of dis-connectivity.
文摘A dual-bias differential method is presented for increasing the detection range of a ternary barcode detection system. The system is provided with a second differential delay circuit with bias control to process optimally gray signals by lowering their averaged level using a clamping circuit. This is added to the primary conventional differential delay circuit without bias control and a comparator to process optimally black signals based on the envelope-differential fixed-period delay (EDFPD) detection technique. This method enables the system to detect over a longer range at high speeds while being capable of handling a large amount of information. The estimate results of gray and white code widths against the clamp bias made through the dynamic operation simulation of a differential circuit using SPICE were nearly consistent with the experimental results. Thereby we can conclude that the dynamic simulation is effective for estimation of an optimum clamp bias voltage. It was confirmed that the detection range of the system with a clamp bias voltage of ?0.4 V for a minimum bar width W = 0.25 mm was 1.4 times that of the conventional EDFPD detection technique. In addition, the system operated at a maximum scanning speed of 7.7 times that of conventional CCD cameras under the practical detection range. The system with clamp bias control is expected to enable the real-time identification of goods on production lines and in automated warehouses.
基金This study is supported by the Indian Council of Medical Research-Vector Control Research Centre intramural funding(project grant no.:IM-1905).
文摘Objective:To report a new species of sandfly,Sergentomyia(Neophlebotomus)ashwanii sp.nov.(Diptera:Psychodidae)from Western Ghats,India.Methods:A systematic sandfly survey was conducted in the Thrissur and Kollam districts of Kerala,India using mechanical aspirators,light and sticky traps,both indoor and outdoor habitats,for a period of one year.Deoxyribonucleic acid barcoding of samples was performed targeting mitochondrial cytochrome oxidase I(COI)gene and sequence generated was subjected to phylogenetic analysis.Results:Sergentomyia(Neophlebotomus)ashwanii,a new sandfly species is recorded and described in this communication.A single row of 10-12 pointed teeth in the cibarium with 4-6 small denticles or fore-teeth are the key characteristics that is distinctive from other members of the subgenus Neophlebotomus.Mitochondrial COI barcode followed by phylogenetic analysis of the nucleotide sequence confirms that specimens of the species belong to the same taxonomic group while the genetic distance(14.2%)with the congeners established it to be a different species.Conclusions:The Western Ghats'being an important biodiversity hotspot and has dearth of systematic entomological surveys on sandflies.The current study tried to fill the void and also report a new sandfly species.
基金Supported by the National Key R&D Program of China (No.2018YFD0900803)the China Agriculture Research System of MOF and MARA (No.CARS-47)the Central Public-Interest Scientific Institution Basal Research Fund (Nos.2021JC01,20603022022024)
文摘The first record of abnormal body coloration in Sebastes koreanus Kim and Lee,1994,from the Yellow Sea of China,was documented based on morphological characteristics and DNA barcoding.The two rockfish specimens were collected from the coastal waters of Qingdao,China,and the whole body and all fins of them were red.Of the two red-colored rockfish,there were tiny deep red spots on each fin,2 red radial stripes behind and below the eyes and 1 large deep red blotch on the opercula,while the similar stripe and spot patterns are also present in the S.koreanus specimens with normal body coloration.The countable characteristics of the two specimens are in the range of the morphometry of S.koreanus.To further clarify the species identity and taxonomic status of the two specimens,DNA barcode analysis was carried out.The genetic distance between the red-colored rockfish and S.koreanus was 0,and the minimum net genetic distances between the red-colored rockfish and other Sebastes species except for S.koreanus were 3.0%,which exceeds the threshold of species delimitation.The phylogenetic analysis showed that the DNA barcoding sequences of the two red-colored rockfish clustered with the S.koreanus sequences.The above results of DNA barcode analysis also support that the two red-colored rockfish could be identified as the species of S.koreanus.The mechanism of color variation in S.koreanus is desirable for further research and the species could be an ideal model to study the color-driven speciation of the rockfishes.
文摘Members of the Goliathus group in the order Coleoptera, family Scarabaeidae and the sub-family Cetoniidae is one among essential ecological insects worldwide with scanty documentation in Tanzania. The country was among the first point of collection of the specimen by Moser (1909) but subsequent attempts to locate and collect the specimen were unsuccessful possibly due to changed habitat and behaviour of Goliathus. Much of published work about the insect are based on the morphological characteristics of collected specimen which led to designation of six major species namely;Goliathus goliatus, G. cacicus, G. regius, G. albosignatus, G. orientalis and G. usambarensis, the last two being considered to exist in Tanzania. The current study reports on successful identification of habitats using biological cues and subsequently collected several Goliathus specimen that had been difficult to trace for more than a century. New insights into correct identity of the species by using a combination of morphological and molecular techniques have been set. The study has resolved that only one species, Goliathus orientalis with five sub-species exist in Tanzania.
文摘The introduction of invasive insect pests across national borders has become a major concern in crop production. Accordingly, national plant protection organizations are challenge to reinforce their monitoring strategies, which are hampered by the weight and size of inspection equipment, as well as the taxonomic extensiveness of interrupted species. Moreover, some insect pests that impede farmer productivity and profitability are difficult for researchers to address on time due to a lack of appropriate plant protection measures. Farmers’ reliance on synthetic pesticides and biocontrol agents has resulted in major economic and environmental ramifications. DNA barcoding is a novel technology that has the potential to improve Integrated Pest Management decision-making, which is dependent on the ability to correctly identify pest and beneficial organisms. This is due to some natural traits such as phenology or pesticide susceptibility browbeaten by IPM strategies to avert pest establishment. Specifically, Deoxyribonucleic acid (DNA) sequence information was applied effectively for the identification of some micro-organisms. This technology, DNA barcoding, allows for the identification of insect species by using short, standardized gene sequences. DNA barcoding is basically based on repeatable and accessible technique that allows for the mechanisation or automation of species discrimination. This technique bridges the taxonomic bio-security gap and meets the International Plant Protection Convention diagnostic standards for insect identification. This review therefore discusses DNA barcoding as a technique for insect pests’ identification and its potential application for crop protection.
基金Support was also provided by Guangzhou Science and Technology Plan Project(No.2019A141405024)。
文摘Background:Spermacoce pusilla Wallich(S.pusilla)is widely used in Guangdong province of China.It has valuable medicinal value in treating trauma,fractures,carbuncle,swelling,and poisonous snake bites.Method:The present study was carried out to provide a scientific basis for the identification and authenticity of S.pusilla with the help of pharmacognostical parameters,which has not been done before.In this study,a series of related identification information such as source,character,microscopic observation,physical and chemical reaction,and molecular markers were employed to establish accurate,comprehensive pharmacognostic identification information of S.pusilla.Results:The study provided some basic data regarding the genuine crude drug.The identification efficiency of ITS sequences obtained in this study is high,the psbA-trnH sequence was obtained from S.pusilla and sequenced for the first time in this study.Conclusion:In this study,traditional pharmacognosy identification and molecular marker identification of S.pusilla in the Guangdong region were carried out,and a systematic and comprehensive pharmacognosy identification information system was established.
文摘The genus Pyrrosia belongs to the family Polypodiaceae and are medium-sized epiphytic ferns,where the dried leaves of Pyrrosia lingua,Pyrrosia sheareri,Pyrrosia lanceolata,and Pyrrosia calvata are commonly used in medicinal practice.In this study,the authenticity of the collected medicinal plant samples of Shiwei was identified with the help of DNA barcoding technology using the internal transcribed spacer 2(ITS2)as the identifying sequence.The experimental samples were analyzed using the basic local alignment search tool(BLAST)and the authenticity of the samples was further verified with the results of similarity comparison.The results proved that the sequences of the experimentally collected samples of Pyrrosia lingua,Pyrrosia sheareri,Pyrrosia lanceolata,and Pyrrosia calvata had a similarity of more than 97%when compared with the corresponding sequences that were uploaded on the Internet.
基金supported by the Fundamental Research Funds for the Central Universities(grant no.TD2012-04)the Scientific Research Foundation of the State Human Resource Ministry and the Education Ministry for Returned Chinese Scholars(to L.Xie)+2 种基金the State Key Laboratory Program from the State Key Laboratory of Systematic and Evolutionary Botany(grant no.LSEB2011-07)the Main Direction Program of Knowledge Innovation of the Chinese Academy of Sciences(grant no.KSCX2-EW-Z-1)the National Natural Science Foundation of China(grant nos.31170201,81072317,31110103911)
文摘Objective Poisonous plants are a deadly threat to public health in China. The traditional clinical diagnosis of the toxic plants is inefficient, fallible, and dependent upon experts. In this study, we tested the performance of DNA barcodes for identification of the most threatening poisonous plants in China. Methods Seventy-four accessions of 27 toxic plant species in 22 genera and 17 families were sampled and three DNA barcodes (motK, rbcL, and ITS) were amplified, sequenced and tested. Three methods, Blast, pairwise global alignment (PWG) distance, and Tree-Building were tested for discrimination power. Results The primer universality of all the three markers was high. Except in the case of ITS for Hemerocollis minor, the three barcodes were successfully generated from all the selected species. Among the three methods applied, Blast showed the lowest discrimination rate, whereas PWG Distance and Tree-Building methods were equally effective. The ITS barcode showed highest discrimination rates using the PWG Distance and Tree-Building methods. When the barcodes were combined, discrimination rates were increased for the Blast method.
文摘This letter presents a method for digital image watermarking for copyright protection. This technique produces a watermarked image that closely retains the quality of the original host image while concurrently surviving various image processing operations such as lowpass/highpass filtering, lossy JPEG compression, and cropping. This image watermarking algorithm takes full advantage of permutation and 2-D barcode (PDF417). The actual watermark embedding in spatial domain is followed using permutated image for improving the resistance to image cropping. Much higher watermark robustness is obtainable via a simple forward error correction technique, which is the main feature of PDF417 codes. Additional features of this technique include the easy determination of the existence of the watermark and that the watermark verification procedure does not need the original host image. The experimental results demonstrate its effectiveness.
基金supported by the China Mega-Project for Infectious Disease(2016ZX10004-101,2016ZX10004-215)Beijing Municipal Science&Technology Commission Project(D151100002115003)Guangzhou Municipal Science&Technology Commission Project(2015B2150820)
文摘Objective To provide a feasible and cost-effective next-generation sequencing (NGS) method for accurate identification of viral pathogens in clinical specimens, because enormous limitations impede the clinical use of common NGS, such as high cost, complicated procedures, tremendous data analysis, and high background noise in clinical samples. Methods Viruses from cell culture materials or clinical specimens were identified following an improved NGS procedure: reduction of background noise by sample preprocessing, viral enrichment by barcoded oligonucleotide (random hexamer or non-ribosomal hexanucleotide) primer-based amplification, fragmentation-free library construction and sequencing of one-tube mixtures, as well as rapid data analysis using an in-house pipeline. Results NGS data demonstrated that both barcoded primer sets were useful to simultaneously capture multiple viral pathogens in cell culture materials or clinical specimens and verified that hexanucleotide primers captured as many viral sequences as hexamers did. Moreover, direct testing of clinical specimens using this improved hexanucleotide primer-based NGS approach provided further detailed genotypes of enteroviruses causing hand, foot, and mouth disease (HFMD) and identified other potential viruses or differentiated misdiagnosis events. Conclusion The improved barcoded oligonucleotide primer-based NGS approach is simplified, time saving, cost effective, and appropriate for direct identification of viral pathogens in clinical practice.
基金Supported by Hainan Provincial Natural Science Foundation of China,High-level Talent Project(321RC587),Classification of sea snakes in the South Sea China based on molecular Systematics,morphology and climate modelSpecial Scientific Research Trial Production Project of Sanya City(2016KS05),Identification of sea snake species and construction of DNA barcoding based on molecular systematics.
文摘[Objectives]The most common gene fragment used in animal DNA barcode technology is COI,but it is not necessarily suitable for all species.This study was conducted to screen genes suitable for the DNA barcode of sea snakes.[Methods]All COI and cytb gene sequences on GenBank were searched and downloaded.After the comparison with Mega software,clustering trees of MrBayes system were established.[Results]Interspecies distances were greater than intraspecies distances for the two genes.The topological structures of their molecular hierarchical clustering trees were clear,and the support rates were high.[Conclusions]Therefore,it is concluded that not the DNA barcode of each species must be gene COI.Cytb is more suitable in terms of the mitochondrial gene of sea snakes.
文摘Molecular markers provide a useful method for genotype characterization and allow a high precision determination of the genetic relationship between cultivars and varieties. A system based on DNA sequences—which is known as DNA barcoding—will choose one or several standard loci which can be sequenced and compared to differentiate between species. In this research, the ITS, matK, and trnH-psbA sequences were evaluated for the molecular identification of seven F. carica genotypes, generating complete sequences for the first two loci, but unable to produce bidirectional sequences by using the trnH-psbA sequence. The ITS sequence presented the highest variation rates, while the phylogeny constructed with the matK sequence obtained the highest percentage of solved monophyletic groups. Through Pearson’s correlation analysis, it was possible to determine the existence of a significant correlation between the ITS region and psbA-trnH, and the matK and psbA-trnH sequences, but not between ITS and matK. The phylogenies constructed with the ITS + matK barcodes and ITS + matK + psbA-trnH presented the highest percentage for resolution. However, considering the cost efficiency and the facilitated recovery by using PCR, the matK + ITS combination is recommended.