Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain lar...Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain largely unclear.In this study,we have assembled a chromosome-scale genome of Japanese catnip(Schizonepeta tenuifolia)and discovered a BGC that contains multiple copies of genes involved in four adjacent steps in the biosynthesis of p-menthane monoterpenoids.This BGC has an unprecedented bipartite structure,with mirrored biosynthetic regions separated by 260 kilobases.This bipartite BGC includes identical copies of a gene encoding an old yellow enzyme,a type of flavin-dependent reductase.In vitro assays and virus-induced gene silencing revealed that this gene encodes the missing isopiperitenone reductase.This enzyme evolved from a completely different enzyme family to isopiperitenone reductase from closely related Mentha spp.,indicating convergent evolution of this pathway step.Phylogenomic analysis revealed that this bipartite BGC has emerged uniquely in the S.tenuifolia lineage and through insertion of pathway genes into a region rich in monoterpene synthases.The cluster gained its bipartite structure via an inverted duplication.The discovered bipartite BGC for p-menthane biosynthesis in S.tenuifolia has similarities to the recently described duplicated p-menthane biosynthesis gene pairs in the Mentha longifolia genome,providing an example of the convergent evolution of gene order.This work expands our understanding of plant BGCs with respect to both form and evolution,and highlights the power of BGCs for gene discovery in plant biosynthetic pathways.展开更多
Matrix inversion is a critical part in communication, signal processing and electromagnetic system. A flexible and scalable very long instruction word （VLIW） processor with clustered architecture is proposed for mat...Matrix inversion is a critical part in communication, signal processing and electromagnetic system. A flexible and scalable very long instruction word （VLIW） processor with clustered architecture is proposed for matrix inversion. A global register file （RF） is used to connect al the clusters. Two nearby clusters share a local register file. The instruction sets are also designed for the VLIW processor. Experimental results show that the proposed VLIW architecture takes only 45 latency to invert a 4 × 4 matrix when running at 150 MHz. The proposed design is roughly five times faster than the DSP solution in processing speed.展开更多
Using the focal mechanism solutions of 24 moderately strong earthquakes in the northern Tianshan area,we carried out system cluster and stress field inversion analysis.The result indicates that,the focal mechanism sol...Using the focal mechanism solutions of 24 moderately strong earthquakes in the northern Tianshan area,we carried out system cluster and stress field inversion analysis.The result indicates that,the focal mechanism solutions of moderately strong earthquakes are mainly dip-slip reverse faulting in the northern Tianshan area.The principal rupture planes of earthquakes are NW-oriented.It is basically consistent with the strike of earthquake structure in its adjacent area.The direction of the principal compression stress P axis is nearly NS,and its inclination angle is small;while the inclination angle of the principal extensional stress T axis is large.It shows that the regional stress field is mainly controlled by the near-NS horizontal compressive stress.The direction of the maximum principal stress shows a gradation process of NNE-NS-NW from east to west.展开更多
A genetic algorithm-based joint inversion method is presented for evaluating hydrocarbon-bearing geological formations. Conventional inversion procedures routinely used in the oil industry perform the inversion proces...A genetic algorithm-based joint inversion method is presented for evaluating hydrocarbon-bearing geological formations. Conventional inversion procedures routinely used in the oil industry perform the inversion processing of borehole geophysical data locally. As having barely more types of data than unknowns in a depth, a set of marginally over-determined inverse problems has to be solved along a borehole, which is a rather noise sensitive procedure. For the reduction of noise effect, the amount of overdetermination must be increased. To fulfill this requirement, we suggest the use of our interval inversion method, which inverts simultaneously all data from a greater depth interval to estimate petrophysical parameters of reservoirs to the same interval. A series expansion based discretization scheme ensures much more data against unknowns that significantly reduces the estimation error of model parameters. The knowledge of reservoir boundaries is also required for reserve calculation. Well logs contain information about layer-thicknesses, but they cannot be extracted by the local inversion approach. We showed earlier that the depth coordinates of layerboundaries can be determined within the interval inversion procedure. The weakness of method is that the output of inversion is highly influenced by arbitrary assumptions made for layer-thicknesses when creating a starting model (i.e. number of layers, search domain of thicknesses). In this study, we apply an automated procedure for the determination of rock interfaces. We perform multidimensional hierarchical cluster analysis on well-logging data before inversion that separates the measuring points of different layers on a lithological basis. As a result, the vertical distribution of clusters furnishes the coordinates of layer-boundaries, which are then used as initial model parameters for the interval inversion procedure. The improved inversion method gives a fast, automatic and objective estimation to layer-boundaries and petrophysical parameters, which is demons展开更多
基金supported by the National Natural Science Foundation of China(grant nos.81973435 and 81473313)the National Natural Science Foundation for Young Scientists of China(grant no.81903756)+2 种基金the Open Project of the Natural Science Foundation of Nanjing University of Chinese Medicine(no.NZY81903756)research on ecological planting and quality assurance of Jiangsu Dao-di herbs(2021)and a Jiangsu Government Scholarship for Overseas Studies(JS-2020-044).We also acknowledge support from the BBSRC(BBN006452/1)and UKRI(MR/S01862X/1).
文摘Biosynthetic gene clusters(BGCs)are regions of a genome where genes involved in a biosynthetic pathway are in proximity.The origin and evolution of plant BGCs as well as their role in specialized metabolism remain largely unclear.In this study,we have assembled a chromosome-scale genome of Japanese catnip(Schizonepeta tenuifolia)and discovered a BGC that contains multiple copies of genes involved in four adjacent steps in the biosynthesis of p-menthane monoterpenoids.This BGC has an unprecedented bipartite structure,with mirrored biosynthetic regions separated by 260 kilobases.This bipartite BGC includes identical copies of a gene encoding an old yellow enzyme,a type of flavin-dependent reductase.In vitro assays and virus-induced gene silencing revealed that this gene encodes the missing isopiperitenone reductase.This enzyme evolved from a completely different enzyme family to isopiperitenone reductase from closely related Mentha spp.,indicating convergent evolution of this pathway step.Phylogenomic analysis revealed that this bipartite BGC has emerged uniquely in the S.tenuifolia lineage and through insertion of pathway genes into a region rich in monoterpene synthases.The cluster gained its bipartite structure via an inverted duplication.The discovered bipartite BGC for p-menthane biosynthesis in S.tenuifolia has similarities to the recently described duplicated p-menthane biosynthesis gene pairs in the Mentha longifolia genome,providing an example of the convergent evolution of gene order.This work expands our understanding of plant BGCs with respect to both form and evolution,and highlights the power of BGCs for gene discovery in plant biosynthetic pathways.
基金supported by the National Natural Science Foundation of China(6110015561227004+4 种基金613720716137213161201289)the Fundamental Research Funds of the Central Universities of China(K5051302096JB140207)
文摘Matrix inversion is a critical part in communication, signal processing and electromagnetic system. A flexible and scalable very long instruction word （VLIW） processor with clustered architecture is proposed for matrix inversion. A global register file （RF） is used to connect al the clusters. Two nearby clusters share a local register file. The instruction sets are also designed for the VLIW processor. Experimental results show that the proposed VLIW architecture takes only 45 latency to invert a 4 × 4 matrix when running at 150 MHz. The proposed design is roughly five times faster than the DSP solution in processing speed.
基金sponsored by the Subject of City ActiveFault Exploration Program of Urumqi and Joint Foundation of Earthquake Administration of Xinjiang Uygur Autonomous Region (200704),China
文摘Using the focal mechanism solutions of 24 moderately strong earthquakes in the northern Tianshan area,we carried out system cluster and stress field inversion analysis.The result indicates that,the focal mechanism solutions of moderately strong earthquakes are mainly dip-slip reverse faulting in the northern Tianshan area.The principal rupture planes of earthquakes are NW-oriented.It is basically consistent with the strike of earthquake structure in its adjacent area.The direction of the principal compression stress P axis is nearly NS,and its inclination angle is small;while the inclination angle of the principal extensional stress T axis is large.It shows that the regional stress field is mainly controlled by the near-NS horizontal compressive stress.The direction of the maximum principal stress shows a gradation process of NNE-NS-NW from east to west.
文摘A genetic algorithm-based joint inversion method is presented for evaluating hydrocarbon-bearing geological formations. Conventional inversion procedures routinely used in the oil industry perform the inversion processing of borehole geophysical data locally. As having barely more types of data than unknowns in a depth, a set of marginally over-determined inverse problems has to be solved along a borehole, which is a rather noise sensitive procedure. For the reduction of noise effect, the amount of overdetermination must be increased. To fulfill this requirement, we suggest the use of our interval inversion method, which inverts simultaneously all data from a greater depth interval to estimate petrophysical parameters of reservoirs to the same interval. A series expansion based discretization scheme ensures much more data against unknowns that significantly reduces the estimation error of model parameters. The knowledge of reservoir boundaries is also required for reserve calculation. Well logs contain information about layer-thicknesses, but they cannot be extracted by the local inversion approach. We showed earlier that the depth coordinates of layerboundaries can be determined within the interval inversion procedure. The weakness of method is that the output of inversion is highly influenced by arbitrary assumptions made for layer-thicknesses when creating a starting model (i.e. number of layers, search domain of thicknesses). In this study, we apply an automated procedure for the determination of rock interfaces. We perform multidimensional hierarchical cluster analysis on well-logging data before inversion that separates the measuring points of different layers on a lithological basis. As a result, the vertical distribution of clusters furnishes the coordinates of layer-boundaries, which are then used as initial model parameters for the interval inversion procedure. The improved inversion method gives a fast, automatic and objective estimation to layer-boundaries and petrophysical parameters, which is demons
