MPEG-1/2-based non-linear editing systems appear to have a tendency to replace the M-JPEG systems, but in so doing it is difficult to realize the video, audio and the synchronization editing algorithms. Such editing a...MPEG-1/2-based non-linear editing systems appear to have a tendency to replace the M-JPEG systems, but in so doing it is difficult to realize the video, audio and the synchronization editing algorithms. Such editing algorithms are presented. Based on an analysis of the structure of the MPEG-1/2 stream, and using parameters of the video, audio and the synchronization information, the video, audio and synchronization editing algorithms are provided. The characters of the algorithms are efficient, the quality loss of frames is low because it only decodes and codes part of the data; the editing algorithm is fast through use of some index files; synchronization editing is realized using the synchronization information, such as PTS, ESCR and other parameters.展开更多
Numerical experiments on non-linear equations of the 1st-and 3rd-order derivatives have been carried out through structural analyses in the phase space according to the numerical instability of ill-posed systems,with ...Numerical experiments on non-linear equations of the 1st-and 3rd-order derivatives have been carried out through structural analyses in the phase space according to the numerical instability of ill-posed systems,with changes of initial values and parameters,etc..The results show that the quantitative instability in an ill-posed system may reveal reversed transformation in system evolution by structural representation,and confirm A·Dauglas' theorem that "a non-linear equation does not satisfy the existence of the initial value in a linear well-posed system".展开更多
Cyber-Physical Systems are very vulnerable to sparse sensor attacks.But current protection mechanisms employ linear and deterministic models which cannot detect attacks precisely.Therefore,in this paper,we propose a n...Cyber-Physical Systems are very vulnerable to sparse sensor attacks.But current protection mechanisms employ linear and deterministic models which cannot detect attacks precisely.Therefore,in this paper,we propose a new non-linear generalized model to describe Cyber-Physical Systems.This model includes unknown multivariable discrete and continuous-time functions and different multiplicative noises to represent the evolution of physical processes and randomeffects in the physical and computationalworlds.Besides,the digitalization stage in hardware devices is represented too.Attackers and most critical sparse sensor attacks are described through a stochastic process.The reconstruction and protectionmechanisms are based on aweighted stochasticmodel.Error probability in data samples is estimated through different indicators commonly employed in non-linear dynamics(such as the Fourier transform,first-return maps,or the probability density function).A decision algorithm calculates the final reconstructed value considering the previous error probability.An experimental validation based on simulation tools and real deployments is also carried out.Both,the new technology performance and scalability are studied.Results prove that the proposed solution protects Cyber-Physical Systems against up to 92%of attacks and perturbations,with a computational delay below 2.5 s.The proposed model shows a linear complexity,as recursive or iterative structures are not employed,just algebraic and probabilistic functions.In conclusion,the new model and reconstructionmechanism can protect successfully Cyber-Physical Systems against sparse sensor attacks,even in dense or pervasive deployments and scenarios.展开更多
The discovery and utilization of RNA-guided surveillance complexes,such as CRISPR-Cas9,for sequencespecific DNA or RNA cleavage,has revolutionised the process of gene modification or knockdown.To optimise the use of t...The discovery and utilization of RNA-guided surveillance complexes,such as CRISPR-Cas9,for sequencespecific DNA or RNA cleavage,has revolutionised the process of gene modification or knockdown.To optimise the use of this technology,an exploratory race has ensued to discover or develop new RNA-guided endonucleases with the most flexible sequence targeting requirements,coupled with high cleavage efficacy and specificity.Here we review the constraints of existing gene editing and assess the merits of exploiting the diversity of CRISPR-Cas effectors as a methodology for surmounting these limitations.展开更多
Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly...Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly interspaced short palindromic repeats/Cas9 （CRISPR/ Cas9） system, which utilizes engineered endonucleases to generate a double-stranded DNA break （DSB） in the target DNA region and subsequently stimulates site-specific mutagenesis through DNA repair machineries, is emerging as a powerful genome editing tool for elucidating mecha- nisms of protection from plant viruses, plant disease resistance, and gene functions in basic and applied research. In this review, we provide an overview of recent advances in the CRISPR system associated genome editing in plants by focusing on application of this technology in model plants, crop plants, fruit plants, woody plants and grasses and discuss how genome editing associated with the CRISPR system can provide insights into genome modifications and functional genomics in plants.展开更多
Stationarity of a class of stochastically interconnecteil discrete-timesystems is analyzed by utilizins results from ergodic theory of general stateMarkov chains, incorporated with the so called large-scale system app...Stationarity of a class of stochastically interconnecteil discrete-timesystems is analyzed by utilizins results from ergodic theory of general stateMarkov chains, incorporated with the so called large-scale system approach.展开更多
In this paper, astochastic predator-prey systems with nonlinear harvesting and impulsive effect are investigated. Firstly, we show the existence and uniqueness of the global positive solution of the system. Secondly, ...In this paper, astochastic predator-prey systems with nonlinear harvesting and impulsive effect are investigated. Firstly, we show the existence and uniqueness of the global positive solution of the system. Secondly, by constructing appropriate Lyapunov function and using comparison theorem with an impulsive differential equation, we study that a positive periodic solution exists. Thirdly, we prove that system is globally attractive. Finally, numerical simulations are presented to show the feasibility of the obtained results.展开更多
CRISPR-Cas tools for mammalian genome editing typically rely on single Cas9 or Cas12a proteins.While type I CRISPR systems in Class I may offer greater specificity and versatility,they are not well-developed for genom...CRISPR-Cas tools for mammalian genome editing typically rely on single Cas9 or Cas12a proteins.While type I CRISPR systems in Class I may offer greater specificity and versatility,they are not well-developed for genome editing.Here,we present an alternative type I-C CRISPR system from Desulfovibrio vulgaris(Dvu)for efficient and precise genome editing in mammalian cells and animals.We optimized the Dvu type I-C editing complex to generate precise deletions at multiple loci in various cell lines and pig primary fibroblast cells using a paired PAM-in crRNA strategy.These edited pig cells can serve as donors for generating transgenic cloned piglets.The Dvu type I-C editor also enabled precise large fragment replacements with homology-directed repair.Additionally,we adapted the Dvu-Cascade effector for cytosine and adenine base editing,developing Dvu-CBE and Dvu-ABE systems.These systems efficiently induced C-to-T and A-to-G substitutions in human genes without double-strand breaks.Off-target analysis confirmed the high specificity of the Dvu type I-C editor.Our findings demonstrate the Dvu type I-C editor′s potential for diverse mammalian genome editing applications,including deletions,fragment replacement,and base editing,with high efficiency and specificity for biomedicine and agriculture.展开更多
The class 2 clustered regularly interspaced short palindromic repeat （CRISPR） systems have been widely used for simultaneous modification of multiple loci in plants. Traditionally, the type II CRISPR-Cas9 or type V ...The class 2 clustered regularly interspaced short palindromic repeat （CRISPR） systems have been widely used for simultaneous modification of multiple loci in plants. Traditionally, the type II CRISPR-Cas9 or type V CRISPR-Cpfl （also known as Cas12a） system is a two-component transcriptional unit （TCTU） in which the Cas9 or Cpf1 protein is expressed from an RNA polymerase （pol） II promoter, whereas the single guide RNA （sgRNA） is typically expressed from a Pol III promoter, such as U6 or U3 promoter.展开更多
The Taylor series expansion method is used to derive an approximation for theaverage total power of a non-linear system subjected to wide-band random excitation with zeromean value. The average dissipating power for n...The Taylor series expansion method is used to derive an approximation for theaverage total power of a non-linear system subjected to wide-band random excitation with zeromean value. The average dissipating power for non-linear systems subjected to randomexcitation is also discussed. The results of the derivation show that the average total power andthe average dissipating Power of a Systems are independent, of the dissipating force of the systemwhen excited by white noise. On the other hand, the average total energy is show,l to be inverselyproportional to damping,. The total power is dependent on both, the input and dissipating powerof the system.展开更多
文摘MPEG-1/2-based non-linear editing systems appear to have a tendency to replace the M-JPEG systems, but in so doing it is difficult to realize the video, audio and the synchronization editing algorithms. Such editing algorithms are presented. Based on an analysis of the structure of the MPEG-1/2 stream, and using parameters of the video, audio and the synchronization information, the video, audio and synchronization editing algorithms are provided. The characters of the algorithms are efficient, the quality loss of frames is low because it only decodes and codes part of the data; the editing algorithm is fast through use of some index files; synchronization editing is realized using the synchronization information, such as PTS, ESCR and other parameters.
文摘Numerical experiments on non-linear equations of the 1st-and 3rd-order derivatives have been carried out through structural analyses in the phase space according to the numerical instability of ill-posed systems,with changes of initial values and parameters,etc..The results show that the quantitative instability in an ill-posed system may reveal reversed transformation in system evolution by structural representation,and confirm A·Dauglas' theorem that "a non-linear equation does not satisfy the existence of the initial value in a linear well-posed system".
基金supported by Comunidad de Madrid within the framework of the Multiannual Agreement with Universidad Politécnica de Madrid to encourage research by young doctors(PRINCE).
文摘Cyber-Physical Systems are very vulnerable to sparse sensor attacks.But current protection mechanisms employ linear and deterministic models which cannot detect attacks precisely.Therefore,in this paper,we propose a new non-linear generalized model to describe Cyber-Physical Systems.This model includes unknown multivariable discrete and continuous-time functions and different multiplicative noises to represent the evolution of physical processes and randomeffects in the physical and computationalworlds.Besides,the digitalization stage in hardware devices is represented too.Attackers and most critical sparse sensor attacks are described through a stochastic process.The reconstruction and protectionmechanisms are based on aweighted stochasticmodel.Error probability in data samples is estimated through different indicators commonly employed in non-linear dynamics(such as the Fourier transform,first-return maps,or the probability density function).A decision algorithm calculates the final reconstructed value considering the previous error probability.An experimental validation based on simulation tools and real deployments is also carried out.Both,the new technology performance and scalability are studied.Results prove that the proposed solution protects Cyber-Physical Systems against up to 92%of attacks and perturbations,with a computational delay below 2.5 s.The proposed model shows a linear complexity,as recursive or iterative structures are not employed,just algebraic and probabilistic functions.In conclusion,the new model and reconstructionmechanism can protect successfully Cyber-Physical Systems against sparse sensor attacks,even in dense or pervasive deployments and scenarios.
基金the National Health and Medical Research Council of Australia(Grant No.APP1143008)the Australian Research Council(Grant No.DP180101494)the National Natural Science Foundation of China(Grant No.81772214).
文摘The discovery and utilization of RNA-guided surveillance complexes,such as CRISPR-Cas9,for sequencespecific DNA or RNA cleavage,has revolutionised the process of gene modification or knockdown.To optimise the use of this technology,an exploratory race has ensued to discover or develop new RNA-guided endonucleases with the most flexible sequence targeting requirements,coupled with high cleavage efficacy and specificity.Here we review the constraints of existing gene editing and assess the merits of exploiting the diversity of CRISPR-Cas effectors as a methodology for surmounting these limitations.
文摘Genome editing is a valuable tool to target specific DNA sequences for mutagenesis in the genomes of microbes, plants, and animals. Although different genome editing technologies are available, the clustered regularly interspaced short palindromic repeats/Cas9 （CRISPR/ Cas9） system, which utilizes engineered endonucleases to generate a double-stranded DNA break （DSB） in the target DNA region and subsequently stimulates site-specific mutagenesis through DNA repair machineries, is emerging as a powerful genome editing tool for elucidating mecha- nisms of protection from plant viruses, plant disease resistance, and gene functions in basic and applied research. In this review, we provide an overview of recent advances in the CRISPR system associated genome editing in plants by focusing on application of this technology in model plants, crop plants, fruit plants, woody plants and grasses and discuss how genome editing associated with the CRISPR system can provide insights into genome modifications and functional genomics in plants.
文摘Stationarity of a class of stochastically interconnecteil discrete-timesystems is analyzed by utilizins results from ergodic theory of general stateMarkov chains, incorporated with the so called large-scale system approach.
文摘In this paper, astochastic predator-prey systems with nonlinear harvesting and impulsive effect are investigated. Firstly, we show the existence and uniqueness of the global positive solution of the system. Secondly, by constructing appropriate Lyapunov function and using comparison theorem with an impulsive differential equation, we study that a positive periodic solution exists. Thirdly, we prove that system is globally attractive. Finally, numerical simulations are presented to show the feasibility of the obtained results.
基金funded by the National Key R&D Program of China(2021YFA0805900,2023YFF1000200,2023YFF1000900,and 2023YFC3402004)the China Postdoctoral Science Foundation(2021M703521).
文摘CRISPR-Cas tools for mammalian genome editing typically rely on single Cas9 or Cas12a proteins.While type I CRISPR systems in Class I may offer greater specificity and versatility,they are not well-developed for genome editing.Here,we present an alternative type I-C CRISPR system from Desulfovibrio vulgaris(Dvu)for efficient and precise genome editing in mammalian cells and animals.We optimized the Dvu type I-C editing complex to generate precise deletions at multiple loci in various cell lines and pig primary fibroblast cells using a paired PAM-in crRNA strategy.These edited pig cells can serve as donors for generating transgenic cloned piglets.The Dvu type I-C editor also enabled precise large fragment replacements with homology-directed repair.Additionally,we adapted the Dvu-Cascade effector for cytosine and adenine base editing,developing Dvu-CBE and Dvu-ABE systems.These systems efficiently induced C-to-T and A-to-G substitutions in human genes without double-strand breaks.Off-target analysis confirmed the high specificity of the Dvu type I-C editor.Our findings demonstrate the Dvu type I-C editor′s potential for diverse mammalian genome editing applications,including deletions,fragment replacement,and base editing,with high efficiency and specificity for biomedicine and agriculture.
文摘The class 2 clustered regularly interspaced short palindromic repeat （CRISPR） systems have been widely used for simultaneous modification of multiple loci in plants. Traditionally, the type II CRISPR-Cas9 or type V CRISPR-Cpfl （also known as Cas12a） system is a two-component transcriptional unit （TCTU） in which the Cas9 or Cpf1 protein is expressed from an RNA polymerase （pol） II promoter, whereas the single guide RNA （sgRNA） is typically expressed from a Pol III promoter, such as U6 or U3 promoter.
文摘The Taylor series expansion method is used to derive an approximation for theaverage total power of a non-linear system subjected to wide-band random excitation with zeromean value. The average dissipating power for non-linear systems subjected to randomexcitation is also discussed. The results of the derivation show that the average total power andthe average dissipating Power of a Systems are independent, of the dissipating force of the systemwhen excited by white noise. On the other hand, the average total energy is show,l to be inverselyproportional to damping,. The total power is dependent on both, the input and dissipating powerof the system.
