Cabbage(Brassica oleracea var.capitata)is a biennial plant with strong self-incompatibility and an obligate requirement for prolonged vernalization by exposure to low temperatures to induce flowering.These characteris...Cabbage(Brassica oleracea var.capitata)is a biennial plant with strong self-incompatibility and an obligate requirement for prolonged vernalization by exposure to low temperatures to induce flowering.These characteristics significantly increase the difficulty of exploiting novel germplasm induced by physical or chemical mutagens.In this study,we report a CRISPR/Cas9 gene-editing system based on endogenous tRNA processing to induce high efficiency and inheritable mutagenesis in cabbage.Using the phytoene desaturase gene BoPDS,the S-receptor kinase gene BoSRK,and the male-sterility-associated gene BoMS1 as the target genes,multisite and multiple gene mutations were achieved using a construct with tandemly arrayed tRNA-sgRNA architecture to express multiple sgRNAs.The BoSRK3 gene mutation suppressed self-incompatibility completely,converting the self-incompatible line into a self-compatible line.In addition,the BoMS1 gene mutation produced a completely male-sterile mutant,which was highly cross compatible with its nonmutant isoline at the flowering stage as a result of a simultaneous BoSRK3 gene mutation,enabling the economic propagation of the male-sterile line through bee-mediated cross-pollination.Interestingly,higher site mutation efficiency was detected when a guide sequence was inserted into a location in the tandemly arrayed tRNA-sgRNA architecture that was distal from the upstream Pol III promoter.In addition,mutation sites were also detected in the paralogous genes of the BoPDS and BoSRK genes that had fully consistent sequences or base mismatches but beyond the“seed”region in the spacer sequence compared with the target sgRNAs.Collectively,our results demonstrate that the CRISPR/Cas9 system,coupled with an endogenous tRNA-processing system,is an efficient tool to improve cabbage traits.展开更多
With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard method...With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard methods based on the combination of the so-called“jet impingement”and“micro-channel”approaches seem extremely promising for possible improvement and future applications in electronics as well as the aerospace and biomedical fields.In this paper,a hybrid heat sink based on these two technologies is analysed in the frame of an integrated model.Dedicated CFD simulation of the coupled flow/temperature fields and orthogonal tests are performed in order to optimize the overall design.The influence of different sets of structural parameters on the cooling performance is examined.It is shown that an optimal scheme exists for which favourable performance can be obtained in terms of hot spot temperature decrease and thermal uniformity improvement.展开更多
Human action recognition has gained popularity because of its worldwide applications such as video surveillance, video retrieval and human– computer interaction. This paper provides a comprehensive overview of notabl...Human action recognition has gained popularity because of its worldwide applications such as video surveillance, video retrieval and human– computer interaction. This paper provides a comprehensive overview of notable advances made by deep neural networks in this field. Firstly, the basic conception of action recognition and its common applications were introduced. Secondly, action recognition was categorized as action classification and action detection according to its respective research goals. And various deep learning frameworks for recognition tasks were discussed in detail and the most challenging datasets and taxonomies were briefly reviewed. Finally, the limitations of the state-of-the-art and promising directions of the research were briefly outlined.展开更多
This paper presents a one-way data transmission method in order to ensure the safety of data transmission from mobile storage to secure PC.First,an optocoupler is used to achieve the one-way transmission of physical c...This paper presents a one-way data transmission method in order to ensure the safety of data transmission from mobile storage to secure PC.First,an optocoupler is used to achieve the one-way transmission of physical channel,so that data can only be transmitted from mobile storage to secure PC,while the opposite direction is no physical channel.Then,a safe and reliable software system is designed which contains one-way communication protocol,fast CRC check method and packet retransmission algorithm together to ensure the safety of data transmission.After that,to obtain the maximum transmission rate,the frequency of data bus(slwr)and the packet size(num)which effect on transmission rate are detailed analyzed.Experimental results show the proposed method is high-efficiency and safe.展开更多
Temperature vegetation dryness index(TVDI)in a triangular or trapezoidal feature space can be calculated from the land surface temperature(LST)and normalized difference vegetation index(NDVI),and has been widely appli...Temperature vegetation dryness index(TVDI)in a triangular or trapezoidal feature space can be calculated from the land surface temperature(LST)and normalized difference vegetation index(NDVI),and has been widely applied to regional drought monitoring.However,thermal infrared sensors cannot penetrate clouds to detect surface information of sub-cloud pixels.In cloudy areas,LST data include a large number of cloudy pixels,seriously degrading the spatial and temporal continuity of drought monitoring.In this paper,the Remotely Sensed Daily Land Surface Temperature Reconstruction model(RSDAST)is combined with the LST reconstructed(RLST)by the RSDAST and applied to drought monitoring in a cloudy area.The drought monitoring capability of the reconstructed temperature vegetation drought index(RTVDI)under cloudy conditions is evaluated by comparing the correlation between land surface observations for soil moisture and the TVDI before and after surface temperature reconstruction.Results show that the effective duration and area of the RTVDI in the study area were larger than those of the original TVDI(OTVDI)in 2011.In addition,RLST/NDVI scatter plots cover a wide range of values,with the fitted dry–wet boundaries more representative of real soil moisture conditions.Under continuously cloudy conditions,the OTVDI inverted from the original LST(OLST)loses its drought monitoring capability,whereas RTVDI can completely and accurately reconstruct surface moisture conditions across the entire study area.The correlation between TVDI and soil moisture is stronger for RTVDI(R=-0.45)than that for OTVDI(R=-0.33).In terms of the spatial and temporal distributions,the R value for correlation between RTVDI and soil moisture was higher than that for OTVDI.Hence,in continuously cloudy areas,RTVDI not only expands drought monitoring capability in time and space,but also improves the accuracy of surface soil moisture monitoring and enhances the applicability and reliability of thermal infrared data under extreme conditions.展开更多
OBJECTIVE: To investigate the underlying mechanism of reduced myocardial ischemia-reperfusion (I/R) injury in rats using the traditionalTibetan medicine Sanweitanxiang powder (SWTX). METHODS: Rats were randomly divide...OBJECTIVE: To investigate the underlying mechanism of reduced myocardial ischemia-reperfusion (I/R) injury in rats using the traditionalTibetan medicine Sanweitanxiang powder (SWTX). METHODS: Rats were randomly divided into six groups (n=10) as follows: (a) propranolol dinitrate control group, given propranolol dinitrate 0.02 g/kg for 10 days before I/R, (b) SWTX with a high dose group, given SWTX 1.5 g/kg for 10 days before I/R, (c) SWTX with a medium dose group, given SWTX 1.25 g/kg for 10 days before I/R, (d) sham group (Sham), in which the rat heart was exposed by pericardiotomy but without I/R, (e) SWTX with a low dose group, given SWTX 1.0 g/kg for 10 days before I/R, and (f) I/R injury group. Rats were intragastrically pretreated with propranolol dinitrate orSWTX. After that, the operation to cause ischemia and reperfusion was conducted.The histopathologic changes of rat hearts were observed by hematoxylin and eosin staining and transmission electron microscopy. Ca2+ homeostasis protein expression was determined by western blot. RESULTS: After SWTX pretreatment, the development of ultrastructural pathological changes from IR injury was attenuated. A decrease in the expression of B-cell lymphoma 2 associated X protein, and an increase in the expression of B-cell lymphoma 2 were observed. An increased activation of extracellular signal regulated kinases were found. Compared with the sham group, the expression of sarcoplasmic reticulum calcium-ATPase, phospholamban, and calsequestrin were all up-regulated after pretreatment with SWTX. CONCLUSION: The protective mechanism of SWTX pretreatment on myocardial I/R injury might be related to its effect on maintaining the balance of calcium homeostasis in rat heart.展开更多
Deep convolutional networks have obtained remarkable achievements on various visual tasks due to their strong ability to learn a variety of features.A welltrained deep convolutional network can be compressed to 20%–4...Deep convolutional networks have obtained remarkable achievements on various visual tasks due to their strong ability to learn a variety of features.A welltrained deep convolutional network can be compressed to 20%–40%of its original size by removing filters that make little contribution,as many overlapping features are generated by redundant filters.Model compression can reduce the number of unnecessary filters but does not take advantage of redundant filters since the training phase is not affected.Modern networks with residual,dense connections and inception blocks are considered to be able to mitigate the overlap in convolutional filters,but do not necessarily overcome the issue.To do so,we propose a new training strategy,weight asynchronous update,which helps to significantly increase the diversity of filters and enhance the representation ability of the network.The proposed method can be widely applied to different convolutional networks without changing the network topology.Our experiments show that the stochastic subset of filters updated in different iterations can significantly reduce filter overlap in convolutional networks.Extensive experiments show that our method yields noteworthy improvements in neural network performance.展开更多
基金the National Key Research and Development Program of China(2017YFD0101804)the Science and Technology Innovation Program for the Social Undertakings and the People's Livelihood in Chongqing(cstc2015shms-ztzx80005,cstc2015shms-ztzx80007,cstc2015shms-ztzx80009)for their financial support.
文摘Cabbage(Brassica oleracea var.capitata)is a biennial plant with strong self-incompatibility and an obligate requirement for prolonged vernalization by exposure to low temperatures to induce flowering.These characteristics significantly increase the difficulty of exploiting novel germplasm induced by physical or chemical mutagens.In this study,we report a CRISPR/Cas9 gene-editing system based on endogenous tRNA processing to induce high efficiency and inheritable mutagenesis in cabbage.Using the phytoene desaturase gene BoPDS,the S-receptor kinase gene BoSRK,and the male-sterility-associated gene BoMS1 as the target genes,multisite and multiple gene mutations were achieved using a construct with tandemly arrayed tRNA-sgRNA architecture to express multiple sgRNAs.The BoSRK3 gene mutation suppressed self-incompatibility completely,converting the self-incompatible line into a self-compatible line.In addition,the BoMS1 gene mutation produced a completely male-sterile mutant,which was highly cross compatible with its nonmutant isoline at the flowering stage as a result of a simultaneous BoSRK3 gene mutation,enabling the economic propagation of the male-sterile line through bee-mediated cross-pollination.Interestingly,higher site mutation efficiency was detected when a guide sequence was inserted into a location in the tandemly arrayed tRNA-sgRNA architecture that was distal from the upstream Pol III promoter.In addition,mutation sites were also detected in the paralogous genes of the BoPDS and BoSRK genes that had fully consistent sequences or base mismatches but beyond the“seed”region in the spacer sequence compared with the target sgRNAs.Collectively,our results demonstrate that the CRISPR/Cas9 system,coupled with an endogenous tRNA-processing system,is an efficient tool to improve cabbage traits.
基金National Natural Science Foundation of China(No.51676030,Zhou,X.M.,http://www.nsfc.gov.cn/)Sichuan Science and Technology Program(No.2019JDRC0026,Zhou,X.M.,http://scst.tccxfw.com/)。
文摘With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit,new strategies are needed to extract heat from these devices in an efficient way.In this regard methods based on the combination of the so-called“jet impingement”and“micro-channel”approaches seem extremely promising for possible improvement and future applications in electronics as well as the aerospace and biomedical fields.In this paper,a hybrid heat sink based on these two technologies is analysed in the frame of an integrated model.Dedicated CFD simulation of the coupled flow/temperature fields and orthogonal tests are performed in order to optimize the overall design.The influence of different sets of structural parameters on the cooling performance is examined.It is shown that an optimal scheme exists for which favourable performance can be obtained in terms of hot spot temperature decrease and thermal uniformity improvement.
基金the National Science Foundation of China (Grant No. 61702350).
文摘Human action recognition has gained popularity because of its worldwide applications such as video surveillance, video retrieval and human– computer interaction. This paper provides a comprehensive overview of notable advances made by deep neural networks in this field. Firstly, the basic conception of action recognition and its common applications were introduced. Secondly, action recognition was categorized as action classification and action detection according to its respective research goals. And various deep learning frameworks for recognition tasks were discussed in detail and the most challenging datasets and taxonomies were briefly reviewed. Finally, the limitations of the state-of-the-art and promising directions of the research were briefly outlined.
文摘This paper presents a one-way data transmission method in order to ensure the safety of data transmission from mobile storage to secure PC.First,an optocoupler is used to achieve the one-way transmission of physical channel,so that data can only be transmitted from mobile storage to secure PC,while the opposite direction is no physical channel.Then,a safe and reliable software system is designed which contains one-way communication protocol,fast CRC check method and packet retransmission algorithm together to ensure the safety of data transmission.After that,to obtain the maximum transmission rate,the frequency of data bus(slwr)and the packet size(num)which effect on transmission rate are detailed analyzed.Experimental results show the proposed method is high-efficiency and safe.
基金Supported by the National Natural Science Foundation of China(41631180 and 41801315)Science and Technology Department of Chongqing Municipality(cstc2019jcyj-msxm X0649)Innovation Project of Chinese Academy of Agricultural Sciences(960-3)。
文摘Temperature vegetation dryness index(TVDI)in a triangular or trapezoidal feature space can be calculated from the land surface temperature(LST)and normalized difference vegetation index(NDVI),and has been widely applied to regional drought monitoring.However,thermal infrared sensors cannot penetrate clouds to detect surface information of sub-cloud pixels.In cloudy areas,LST data include a large number of cloudy pixels,seriously degrading the spatial and temporal continuity of drought monitoring.In this paper,the Remotely Sensed Daily Land Surface Temperature Reconstruction model(RSDAST)is combined with the LST reconstructed(RLST)by the RSDAST and applied to drought monitoring in a cloudy area.The drought monitoring capability of the reconstructed temperature vegetation drought index(RTVDI)under cloudy conditions is evaluated by comparing the correlation between land surface observations for soil moisture and the TVDI before and after surface temperature reconstruction.Results show that the effective duration and area of the RTVDI in the study area were larger than those of the original TVDI(OTVDI)in 2011.In addition,RLST/NDVI scatter plots cover a wide range of values,with the fitted dry–wet boundaries more representative of real soil moisture conditions.Under continuously cloudy conditions,the OTVDI inverted from the original LST(OLST)loses its drought monitoring capability,whereas RTVDI can completely and accurately reconstruct surface moisture conditions across the entire study area.The correlation between TVDI and soil moisture is stronger for RTVDI(R=-0.45)than that for OTVDI(R=-0.33).In terms of the spatial and temporal distributions,the R value for correlation between RTVDI and soil moisture was higher than that for OTVDI.Hence,in continuously cloudy areas,RTVDI not only expands drought monitoring capability in time and space,but also improves the accuracy of surface soil moisture monitoring and enhances the applicability and reliability of thermal infrared data under extreme conditions.
基金Supported by a Grant from the National Natural Sciences Foundation of China(No.81060368)
文摘OBJECTIVE: To investigate the underlying mechanism of reduced myocardial ischemia-reperfusion (I/R) injury in rats using the traditionalTibetan medicine Sanweitanxiang powder (SWTX). METHODS: Rats were randomly divided into six groups (n=10) as follows: (a) propranolol dinitrate control group, given propranolol dinitrate 0.02 g/kg for 10 days before I/R, (b) SWTX with a high dose group, given SWTX 1.5 g/kg for 10 days before I/R, (c) SWTX with a medium dose group, given SWTX 1.25 g/kg for 10 days before I/R, (d) sham group (Sham), in which the rat heart was exposed by pericardiotomy but without I/R, (e) SWTX with a low dose group, given SWTX 1.0 g/kg for 10 days before I/R, and (f) I/R injury group. Rats were intragastrically pretreated with propranolol dinitrate orSWTX. After that, the operation to cause ischemia and reperfusion was conducted.The histopathologic changes of rat hearts were observed by hematoxylin and eosin staining and transmission electron microscopy. Ca2+ homeostasis protein expression was determined by western blot. RESULTS: After SWTX pretreatment, the development of ultrastructural pathological changes from IR injury was attenuated. A decrease in the expression of B-cell lymphoma 2 associated X protein, and an increase in the expression of B-cell lymphoma 2 were observed. An increased activation of extracellular signal regulated kinases were found. Compared with the sham group, the expression of sarcoplasmic reticulum calcium-ATPase, phospholamban, and calsequestrin were all up-regulated after pretreatment with SWTX. CONCLUSION: The protective mechanism of SWTX pretreatment on myocardial I/R injury might be related to its effect on maintaining the balance of calcium homeostasis in rat heart.
基金the National Natural Science Foundation of China under Grant No.61702350。
文摘Deep convolutional networks have obtained remarkable achievements on various visual tasks due to their strong ability to learn a variety of features.A welltrained deep convolutional network can be compressed to 20%–40%of its original size by removing filters that make little contribution,as many overlapping features are generated by redundant filters.Model compression can reduce the number of unnecessary filters but does not take advantage of redundant filters since the training phase is not affected.Modern networks with residual,dense connections and inception blocks are considered to be able to mitigate the overlap in convolutional filters,but do not necessarily overcome the issue.To do so,we propose a new training strategy,weight asynchronous update,which helps to significantly increase the diversity of filters and enhance the representation ability of the network.The proposed method can be widely applied to different convolutional networks without changing the network topology.Our experiments show that the stochastic subset of filters updated in different iterations can significantly reduce filter overlap in convolutional networks.Extensive experiments show that our method yields noteworthy improvements in neural network performance.