While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms...While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms to produce diversity,including class switch recombination(CSR),subclass differentiation,and alternative expression of the same gene.Many species of birds,reptiles,and amphibians express a truncated isoform of immunoglobulin Y(IgY),termed IgY(ΔFc),which lacks theυCH3 andυCH4 domains.In Anseriformes,IgY(ΔFc)arises from alternative transcriptional termination sites within the sameυgene,whereas in some turtles,intact IgY and IgY(ΔFc)are encoded by distinct genes.Different from the previously reported IgY(ΔFc)variants,this study identified a truncated IgY in the snake Elaphe taeniura,characterized by the loss of only a portion of the CH4 domain.Western blotting and liquid chromatographytandem mass spectrometry confirmed that this truncated IgY is generated by post-translational cleavage at N338 within the IgY heavy chain constant(CH)region.Furthermore,both human and snake asparaginyl endopeptidase were shown to cleave snake IgY in vitro.These findings reveal a novel mechanism for the production of shortened IgY forms,demonstrating that the immunoglobulin CH region undergoes diversification through distinct strategies across vertebrates.展开更多
Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking ...Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking C-terminal truncating mutations in patients.492stop/Y mice exhibit altered dendritic spine morphology and spontaneous seizure-like behaviors,alongside other behavioral deficits.After creating cell lines with various Cdkl5 truncating mutations,we found that these mutations are regulated by the nonsense-mediated RNA decay pathway.Most truncating mutations result in CDKL5 protein loss,leading to multiple disease phenotypes,and offering new insights into the pathogenesis of CDKL5 disorder.展开更多
传统的三维重建技术在面对移动物体干扰时难以有效完成场景重建任务。针对该问题,本文提出一种基于SLAM(Simultaneous Localization and Mapping)、TSDF(Truncated Signed Distance Function)和SCNet(Sample Consistency Networks)实例...传统的三维重建技术在面对移动物体干扰时难以有效完成场景重建任务。针对该问题,本文提出一种基于SLAM(Simultaneous Localization and Mapping)、TSDF(Truncated Signed Distance Function)和SCNet(Sample Consistency Networks)实例分割网络的三维重建方法ORBTSDF-SCNet。该方法采用深度相机或双目相机获取重建物体及场景的深度图与RGB图,且基于ORB_SLAM2实时获取位姿信息;采用基于结构化点云数据的表面重建算法TSDF与深度图相结合,实现在线三维模型重建;为了消除场景中移动物体对场景三维重建的干扰,提出采用SCNet实例分割网络检测和分割移动物体,并结合优化策略减小检测和实例分割误差以及深度图和RGB图对准误差。通过抠除移动物体,保证了重建场景的完整性。在ICL-NUIM、TUM数据集上的实验表明了本文所提方法的有效性。展开更多
In this paper, first we calculate finite-difference coefficients of implicit finite- difference methods （IFDM） for the first and second-order derivatives on normal grids and first- order derivatives on staggered gri...In this paper, first we calculate finite-difference coefficients of implicit finite- difference methods （IFDM） for the first and second-order derivatives on normal grids and first- order derivatives on staggered grids and find that small coefficients of high-order IFDMs exist. Dispersion analysis demonstrates that omitting these small coefficients can retain approximately the same order accuracy but greatly reduce computational costs. Then, we introduce a mirrorimage symmetric boundary condition to improve IFDMs accuracy and stability and adopt the hybrid absorbing boundary condition （ABC） to reduce unwanted reflections from the model boundary. Last, we give elastic wave modeling examples for homogeneous and heterogeneous models to demonstrate the advantages of the proposed scheme.展开更多
A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-...A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-length CrylAh toxin. In this study, plant expression vector pMhGM harboring truncated crylAh gene was transformed into maize （Zea mays L.） immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions （madMARs） were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efficiency of 5% around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer （Ostriniafurnacalis）. These two events were further confirmed by molecular analysis. Southern blot suggested that a single copy of the crylAh gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene crylAh was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T l-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.展开更多
由于原始TSDF(Truncated Signed Distance Function,TSDF)模型仅考虑相邻时间上的关联,误差将不可避免的累积到下一时刻,无法构建全局一致的地图。为了实时精确的建立大场景稠密3D地图,对TSDF模型进行了改进。首先,构筑相机位姿模型和...由于原始TSDF(Truncated Signed Distance Function,TSDF)模型仅考虑相邻时间上的关联,误差将不可避免的累积到下一时刻,无法构建全局一致的地图。为了实时精确的建立大场景稠密3D地图,对TSDF模型进行了改进。首先,构筑相机位姿模型和加权融合3D点截断信息的TSDF模型,用于准确表示创建物体的表面。其次,提出一种改进的回环检测方法,并将其与随机蕨类彩色图像编码化相结合,进而优化TSDF模型,即混合优化位姿模型。最后,使用g2o图优化库解算约束函数,建立数据集间的优化边。实验结果表明:混合优化位姿模型能识别曾到达区域,特别在较大场景下使用可以得到更加准确的相机轨迹和地图。采用TUM数据集中的fr1/xyz、fr1/room、fr1/desk对所提算法进行检验,结果表明该方法能够使相机轨迹的均方根误差分别下降0.59cm,3.14cm,0.94cm。在室内环境和公开数据集上的实验结果证明了所提算法的有效性和准确性。展开更多
Finite-difference methods with high-order accuracy have been utilized to improve the precision of numerical solution for partial differential equations. However, the computation cost generally increases linearly with ...Finite-difference methods with high-order accuracy have been utilized to improve the precision of numerical solution for partial differential equations. However, the computation cost generally increases linearly with increased order of accuracy. Upon examination of the finite-difference formulas for the first-order and second-order derivatives, and the staggered finite-difference formulas for the first-order derivative, we examine the variation of finite-difference coefficients with accuracy order and note that there exist some very small coefficients. With the order increasing, the number of these small coefficients increases, however, the values decrease sharply. An error analysis demonstrates that omitting these small coefficients not only maintain approximately the same level of accuracy of finite difference but also reduce computational cost significantly. Moreover, it is easier to truncate for the high-order finite-difference formulas than for the pseudospectral for- mulas. Thus this study proposes a truncated high-order finite-difference method, and then demonstrates the efficiency and applicability of the method with some numerical examples.展开更多
This paper proves some uniqueness theorems for meromorphic mappings in several complex variables into the complex projective space p^N（C） with truncated multiplicities, and our results improve some earlier work.
With the floating structures pushing their activities to the ultra-deep water, model tests have presented a challenge due to the limitation of the existing wave basins. Therefore, the concept of truncated mooring syst...With the floating structures pushing their activities to the ultra-deep water, model tests have presented a challenge due to the limitation of the existing wave basins. Therefore, the concept of truncated mooring system is implemented to replace the full depth mooring system in the model tests, which aims to have the same dynamic responses as the full depth system. The truncated mooring system plays such a significant role that extra attention should be paid to the mooring systems with large truncation factor. Three different types of large truncation factor mooring system are being employed in the simulations, including the homogenously truncated mooring system, non-homogenously truncated mooring system and simplified truncated mooring system. A catenary moored semi-submersible operating at 1000 m water depth is presented. In addition, truncated mooring systems are proposed at the truncated water depth of 200 m. In order to explore the applicability of these truncated mooring systems, numerical simulations of the platform’s surge free decay interacting with three different styles of truncated mooring systems are studied in calm water. Furthermore, the mooring-induced damping of the truncated mooring systems is simulated in the regular wave. Finally, the platform motion responses and mooring line dynamics are simulated in irregular wave. All these simulations are implemented by employing full time domain coupled dynamic analysis, and the results are compared with those of the full depth simulations in the same cases. The results show that the mooring-induced damping plays a significant role in platform motion responses, and all truncated mooring systems are suitable for model tests with appropriate truncated mooring line diameters. However, a large diameter is needed for simplified truncated mooring lines. The suggestions are given to the selection of truncated mooring system for different situations as well as to the truncated mooring design criteria.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,Southwest Minzu University(ZYN2023097)Scientific and Technological Innovation Team for Qinghai-Xizang Plateau Research in Southwest Minzu University(2024CXTD13)。
文摘While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms to produce diversity,including class switch recombination(CSR),subclass differentiation,and alternative expression of the same gene.Many species of birds,reptiles,and amphibians express a truncated isoform of immunoglobulin Y(IgY),termed IgY(ΔFc),which lacks theυCH3 andυCH4 domains.In Anseriformes,IgY(ΔFc)arises from alternative transcriptional termination sites within the sameυgene,whereas in some turtles,intact IgY and IgY(ΔFc)are encoded by distinct genes.Different from the previously reported IgY(ΔFc)variants,this study identified a truncated IgY in the snake Elaphe taeniura,characterized by the loss of only a portion of the CH4 domain.Western blotting and liquid chromatographytandem mass spectrometry confirmed that this truncated IgY is generated by post-translational cleavage at N338 within the IgY heavy chain constant(CH)region.Furthermore,both human and snake asparaginyl endopeptidase were shown to cleave snake IgY in vitro.These findings reveal a novel mechanism for the production of shortened IgY forms,demonstrating that the immunoglobulin CH region undergoes diversification through distinct strategies across vertebrates.
基金supported by the Innovation of Science and Technology 2030-Major Project"Platform of Nonhuman Primate Models"(2021ZD0200900)the Ministry of Science and Technology(2018YFA0801404)+1 种基金the National Natural Science Foundation of China(82021001)the Shanghai Municipal Science and Technology Major Project.
文摘Mutations in the cyclin-dependent kinase-like 5 gene(CDKL5)cause a severe neurodevelopmental disorder,yet the impact of truncating mutations remains unclear.Here,we introduce the Cdkl5^(492stop) mouse model,mimicking C-terminal truncating mutations in patients.492stop/Y mice exhibit altered dendritic spine morphology and spontaneous seizure-like behaviors,alongside other behavioral deficits.After creating cell lines with various Cdkl5 truncating mutations,we found that these mutations are regulated by the nonsense-mediated RNA decay pathway.Most truncating mutations result in CDKL5 protein loss,leading to multiple disease phenotypes,and offering new insights into the pathogenesis of CDKL5 disorder.
文摘传统的三维重建技术在面对移动物体干扰时难以有效完成场景重建任务。针对该问题,本文提出一种基于SLAM(Simultaneous Localization and Mapping)、TSDF(Truncated Signed Distance Function)和SCNet(Sample Consistency Networks)实例分割网络的三维重建方法ORBTSDF-SCNet。该方法采用深度相机或双目相机获取重建物体及场景的深度图与RGB图,且基于ORB_SLAM2实时获取位姿信息;采用基于结构化点云数据的表面重建算法TSDF与深度图相结合,实现在线三维模型重建;为了消除场景中移动物体对场景三维重建的干扰,提出采用SCNet实例分割网络检测和分割移动物体,并结合优化策略减小检测和实例分割误差以及深度图和RGB图对准误差。通过抠除移动物体,保证了重建场景的完整性。在ICL-NUIM、TUM数据集上的实验表明了本文所提方法的有效性。
基金supported by the National Natural Science Foundation of China(NSFC)(Grant No. 41074100)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No. NCET-10-0812)
文摘In this paper, first we calculate finite-difference coefficients of implicit finite- difference methods （IFDM） for the first and second-order derivatives on normal grids and first- order derivatives on staggered grids and find that small coefficients of high-order IFDMs exist. Dispersion analysis demonstrates that omitting these small coefficients can retain approximately the same order accuracy but greatly reduce computational costs. Then, we introduce a mirrorimage symmetric boundary condition to improve IFDMs accuracy and stability and adopt the hybrid absorbing boundary condition （ABC） to reduce unwanted reflections from the model boundary. Last, we give elastic wave modeling examples for homogeneous and heterogeneous models to demonstrate the advantages of the proposed scheme.
基金the financial support of the Genetically Modified Organisms Breeding Major Project, China (2011ZX08003-001)the National Basic Research Program of China (973 Program, 2009CB118902)the National Natural Science Foundation of China (30970231)
文摘A novel insecticidal gene crylAh was cloned from Bacillus thuringiensis isolate BT8 previously for plant genetic engineering improvement. Truncated active CrylAh toxin has a toxicity level similar to that of the full-length CrylAh toxin. In this study, plant expression vector pMhGM harboring truncated crylAh gene was transformed into maize （Zea mays L.） immature embryos by Agrobacterium tumefaciens-mediated transformation at which maize alcohol dehydrogenase matrix attachment regions （madMARs） were incorporated on both sides of the gene expression cassette to improve gene expression. A total of 23 PCR positive events were obtained with a transformation efficiency of 5% around. Bioassay results showed that events 1-4 and 1-5 exhibited enhanced resistance to the Asian corn borer （Ostriniafurnacalis）. These two events were further confirmed by molecular analysis. Southern blot suggested that a single copy of the crylAh gene was successfully integrated into the maize genome. Western blot and ELISA showed that the foreign gene crylAh was expressed stably at high level in maize and could be inherited stably over generations. The results of a bioassay of T l-T4 transgenic maize plants indicated that the transgenic plants were highly toxic to the Asian corn borer and their resistance could be inherited stably from generation to generation. Thus, events 1-4 and 1-5 are good candidates for the breeding of insect-resistant maize.
文摘由于原始TSDF(Truncated Signed Distance Function,TSDF)模型仅考虑相邻时间上的关联,误差将不可避免的累积到下一时刻,无法构建全局一致的地图。为了实时精确的建立大场景稠密3D地图,对TSDF模型进行了改进。首先,构筑相机位姿模型和加权融合3D点截断信息的TSDF模型,用于准确表示创建物体的表面。其次,提出一种改进的回环检测方法,并将其与随机蕨类彩色图像编码化相结合,进而优化TSDF模型,即混合优化位姿模型。最后,使用g2o图优化库解算约束函数,建立数据集间的优化边。实验结果表明:混合优化位姿模型能识别曾到达区域,特别在较大场景下使用可以得到更加准确的相机轨迹和地图。采用TUM数据集中的fr1/xyz、fr1/room、fr1/desk对所提算法进行检验,结果表明该方法能够使相机轨迹的均方根误差分别下降0.59cm,3.14cm,0.94cm。在室内环境和公开数据集上的实验结果证明了所提算法的有效性和准确性。
基金supported by China Scholarship Council and partially by the National "863" Program of China under contract No. 2007AA06Z218.
文摘Finite-difference methods with high-order accuracy have been utilized to improve the precision of numerical solution for partial differential equations. However, the computation cost generally increases linearly with increased order of accuracy. Upon examination of the finite-difference formulas for the first-order and second-order derivatives, and the staggered finite-difference formulas for the first-order derivative, we examine the variation of finite-difference coefficients with accuracy order and note that there exist some very small coefficients. With the order increasing, the number of these small coefficients increases, however, the values decrease sharply. An error analysis demonstrates that omitting these small coefficients not only maintain approximately the same level of accuracy of finite difference but also reduce computational cost significantly. Moreover, it is easier to truncate for the high-order finite-difference formulas than for the pseudospectral for- mulas. Thus this study proposes a truncated high-order finite-difference method, and then demonstrates the efficiency and applicability of the method with some numerical examples.
基金supported in part by the National Natural Science Foundation of China(10971156,11271291)
文摘This paper proves some uniqueness theorems for meromorphic mappings in several complex variables into the complex projective space p^N（C） with truncated multiplicities, and our results improve some earlier work.
基金financially supported by the National Natural Science Foundation of China(Grant No.51379095)
文摘With the floating structures pushing their activities to the ultra-deep water, model tests have presented a challenge due to the limitation of the existing wave basins. Therefore, the concept of truncated mooring system is implemented to replace the full depth mooring system in the model tests, which aims to have the same dynamic responses as the full depth system. The truncated mooring system plays such a significant role that extra attention should be paid to the mooring systems with large truncation factor. Three different types of large truncation factor mooring system are being employed in the simulations, including the homogenously truncated mooring system, non-homogenously truncated mooring system and simplified truncated mooring system. A catenary moored semi-submersible operating at 1000 m water depth is presented. In addition, truncated mooring systems are proposed at the truncated water depth of 200 m. In order to explore the applicability of these truncated mooring systems, numerical simulations of the platform’s surge free decay interacting with three different styles of truncated mooring systems are studied in calm water. Furthermore, the mooring-induced damping of the truncated mooring systems is simulated in the regular wave. Finally, the platform motion responses and mooring line dynamics are simulated in irregular wave. All these simulations are implemented by employing full time domain coupled dynamic analysis, and the results are compared with those of the full depth simulations in the same cases. The results show that the mooring-induced damping plays a significant role in platform motion responses, and all truncated mooring systems are suitable for model tests with appropriate truncated mooring line diameters. However, a large diameter is needed for simplified truncated mooring lines. The suggestions are given to the selection of truncated mooring system for different situations as well as to the truncated mooring design criteria.
