A two-stage automatic key frame selection method is proposed to enhance stitching speed and quality for UAV aerial videos. In the first stage, to reduce redundancy, the overlapping rate of the UAV aerial video sequenc...A two-stage automatic key frame selection method is proposed to enhance stitching speed and quality for UAV aerial videos. In the first stage, to reduce redundancy, the overlapping rate of the UAV aerial video sequence within the sampling period is calculated. Lagrange interpolation is used to fit the overlapping rate curve of the sequence. An empirical threshold for the overlapping rate is then applied to filter candidate key frames from the sequence. In the second stage, the principle of minimizing remapping spots is used to dynamically adjust and determine the final key frame close to the candidate key frames. Comparative experiments show that the proposed method significantly improves stitching speed and accuracy by more than 40%.展开更多
Transposable element-based molecular markers can be utilized to investigate genetic diversity and to create genetic linkage maps.In this study,Class I and class II transposons were employed to obtain a comparative acc...Transposable element-based molecular markers can be utilized to investigate genetic diversity and to create genetic linkage maps.In this study,Class I and class II transposons were employed to obtain a comparative account of genetic diversity between wild and cultivated barley genotypes.Three types of PCR-based techniques were used:IMP(Inter MITE Polymorphism),IRAP(Inter-Retrotransposon Amplified Polymorphism)and REMAP(Retrotransposon-Microsatellite Amplified Polymorphism).Specific primer pairs for IMP,IRAP,and REMAP detected a total of 200 bands with an average of 20 bands per marker.The mean polymorphic information content(PIC)and discrimination power(D)values in all 47 genotypes from these three types of transposon-based polymorphisms were 0.910 and0.935,respectively.Unweighted Pair Group Method with Arithmetic mean(UPGMA)-based cluster analysis classified all 47 genotypes,both wild and cultivated,into separate groups consistent with their geographical origins.Sequencing followed by chromosome location of polymorphic bands enables precise gene introgression from wild gene pool to cultivated barley.The highly polymorphic nature of these marker systems makes them suitable for use in varietal identification and MAS-based breeding programs in barley and other cereals.展开更多
Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore...Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore,there is impetus to understand mechanisms underlying the pathophysiology of injury and subsequent reorganization of the motor tract that may lead to recovery.After acute central nervous system injury,there are changes in the microenvironment and structure of the motor tract.For example,ischemic stroke involves decreased local blood flow and tissue death from lack of oxygen and nutrients.Traumatic injury,in contrast,causes stretching and shearing injury to microstructures,including myelinated axons and their surrounding vessels.Both involve blood-brain barrier dysfunction,which is an important initial event.After acute central nervous system injury,motor tract reorganization occurs in the form of cortical remapping in the gray matter and axonal regeneration and rewiring in the white matter.Cortical remapping involves one cortical region taking on the role of another.cAMP-response-element binding protein is a key transcription factor that can enhance plasticity in the peri-infarct cortex.Axonal regeneration and rewiring depend on complex cell-cell interactions between axons,oligodendrocytes,and other cells.The RhoA/Rho-associated coiled-coil containing kinase signaling pathway plays a central role in axon growth/regeneration through interactions with myelin-derived axonal growth inhibitors and regulation of actin cytoskeletal dynamics.Oligodendrocytes and their precursors play a role in myelination,and neurons are involved through their voltage-gated calcium channels.Understanding the pathophysiology of injury and the biology of motor tract reorganization may allow the development of therapies to enhance recovery after acute central nervous system injury.These include targeted rehabilitation,novel pharmacotherapies,such as growth factors and axonal growth inhibitor blockade,and the implementation of neurotechnologies,such as central nervous system stimulators and robotics.The translation of these advances depends on careful alignment of preclinical studies and human clinical trials.As experimental data mount,the future is one of optimism.展开更多
A new flux-based hybrid subcell-remapping algorithm for staggered multimaterial arbitrary Lagrangian-Eulerian (MMALE) methods is presented. This new method is an effective generalization of the original subcell-remapp...A new flux-based hybrid subcell-remapping algorithm for staggered multimaterial arbitrary Lagrangian-Eulerian (MMALE) methods is presented. This new method is an effective generalization of the original subcell-remapping method to the multi-material regime (LOUBERE, R. and SHASHKOV,M. A subcell remapping method on staggered polygonal grids for arbitrary-Lagrangian-Eulerian methods. Journal of Computational Physics, 209, 105–138 (2005)). A complete remapping procedure of all fluid quantities is described detailedly in this paper. In the pure material regions, remapping of mass and internal energy is performed by using the original subcell-remapping method. In the regions near the material interfaces, remapping of mass and internal energy is performed with the intersection-based fluxes where intersections are performed between the swept regions and pure material polygons in the Lagrangian mesh, and an approximate approach is then introduced for constructing the subcell mass fluxes. In remapping of the subcell momentum, the mass fluxes are used to construct the momentum fluxes by multiplying a reconstructed velocity in the swept region. The nodal velocity is then conservatively recovered. Some numerical examples simulated in the full MMALE regime and several purely cyclic remapping examples are presented to prove the properties of the remapping method.展开更多
The ERA-Interim reanalysis wind based on the distance-weighted average remapping for studying the wind circulation in Nigeria is presented. The wind flow using this atmospheric model simulation is studied for identifi...The ERA-Interim reanalysis wind based on the distance-weighted average remapping for studying the wind circulation in Nigeria is presented. The wind flow using this atmospheric model simulation is studied for identification of grid-tie electrification opportunities in different wind locations. A 10-year reanalysis wind speed components at a surface level of the planetary layer at 0.25° × 0.25° spatial resolution is obtained and remapped into a new horizontal wind field at a grid resolution of 0.125° × 0.125° covering longitudinal and latitudinal directions of 3.0 - 15.0°E and 15.0 - 3.0°N, respectively. Using the distance-weighted average technique, the remapped wind field at a new grid resolution of 0.125° × 0.125° is compared at different terrain elevations and approximated close to the actual wind field of the same resolution. To determine the suitability of the prevailing wind for small-scale energy conversion, the magnitude of wind flow across the remapped wind field is studied for a 10-year period. Analysis shows that northern regions of Nigeria have a fair wind potential for a stand-alone application based on the wind flow originated at Gulf of Guinea as well as Chad and Niger. Furthermore, hourly surface wind speed observations from 18 synoptic stations in Nigeria are obtained and compared with the bilinear interpolated wind stations. The reanalysis wind reflects the surface wind observations and proves that the prevailing wind in Nigeria is higher than the reanalysis wind projection obtained from gridded data at resolution of 0.125° × 0.125°. The sectorwise wind directions at each synoptic stations for a period of 10 years are presented.展开更多
文摘A two-stage automatic key frame selection method is proposed to enhance stitching speed and quality for UAV aerial videos. In the first stage, to reduce redundancy, the overlapping rate of the UAV aerial video sequence within the sampling period is calculated. Lagrange interpolation is used to fit the overlapping rate curve of the sequence. An empirical threshold for the overlapping rate is then applied to filter candidate key frames from the sequence. In the second stage, the principle of minimizing remapping spots is used to dynamically adjust and determine the final key frame close to the candidate key frames. Comparative experiments show that the proposed method significantly improves stitching speed and accuracy by more than 40%.
基金support of the Natural Sciences and Engineering Research Council (NSERC-Discovery) of Canada (RGPIN-2015-06652)
文摘Transposable element-based molecular markers can be utilized to investigate genetic diversity and to create genetic linkage maps.In this study,Class I and class II transposons were employed to obtain a comparative account of genetic diversity between wild and cultivated barley genotypes.Three types of PCR-based techniques were used:IMP(Inter MITE Polymorphism),IRAP(Inter-Retrotransposon Amplified Polymorphism)and REMAP(Retrotransposon-Microsatellite Amplified Polymorphism).Specific primer pairs for IMP,IRAP,and REMAP detected a total of 200 bands with an average of 20 bands per marker.The mean polymorphic information content(PIC)and discrimination power(D)values in all 47 genotypes from these three types of transposon-based polymorphisms were 0.910 and0.935,respectively.Unweighted Pair Group Method with Arithmetic mean(UPGMA)-based cluster analysis classified all 47 genotypes,both wild and cultivated,into separate groups consistent with their geographical origins.Sequencing followed by chromosome location of polymorphic bands enables precise gene introgression from wild gene pool to cultivated barley.The highly polymorphic nature of these marker systems makes them suitable for use in varietal identification and MAS-based breeding programs in barley and other cereals.
基金supported in part by JSPS“KAKENHI”Grant-in-Aid for Early-Career Scientists,Grant No.18K16566(to HT)Research Abroad from the Japan Brain Foundation(to HT)+2 种基金Mochida Memorial Foundation for Medical and Pharmaceutical Research of Japan(to HT)the Rotary Foundation Global Scholarship Grants,Grant Nos.GG1759314,GG1876795)(to HT)the National Institute of Neurological Disorders and Stroke of USA,No.R25 NS065743(to RWR).
文摘Acute central nervous system injuries are among the most common causes of disability worldwide,with widespread social and economic implications.Motor tract injury accounts for the majority of this disability;therefore,there is impetus to understand mechanisms underlying the pathophysiology of injury and subsequent reorganization of the motor tract that may lead to recovery.After acute central nervous system injury,there are changes in the microenvironment and structure of the motor tract.For example,ischemic stroke involves decreased local blood flow and tissue death from lack of oxygen and nutrients.Traumatic injury,in contrast,causes stretching and shearing injury to microstructures,including myelinated axons and their surrounding vessels.Both involve blood-brain barrier dysfunction,which is an important initial event.After acute central nervous system injury,motor tract reorganization occurs in the form of cortical remapping in the gray matter and axonal regeneration and rewiring in the white matter.Cortical remapping involves one cortical region taking on the role of another.cAMP-response-element binding protein is a key transcription factor that can enhance plasticity in the peri-infarct cortex.Axonal regeneration and rewiring depend on complex cell-cell interactions between axons,oligodendrocytes,and other cells.The RhoA/Rho-associated coiled-coil containing kinase signaling pathway plays a central role in axon growth/regeneration through interactions with myelin-derived axonal growth inhibitors and regulation of actin cytoskeletal dynamics.Oligodendrocytes and their precursors play a role in myelination,and neurons are involved through their voltage-gated calcium channels.Understanding the pathophysiology of injury and the biology of motor tract reorganization may allow the development of therapies to enhance recovery after acute central nervous system injury.These include targeted rehabilitation,novel pharmacotherapies,such as growth factors and axonal growth inhibitor blockade,and the implementation of neurotechnologies,such as central nervous system stimulators and robotics.The translation of these advances depends on careful alignment of preclinical studies and human clinical trials.As experimental data mount,the future is one of optimism.
基金Project supported by the China Postdoctoral Science Foundation(No.2017M610823)
文摘A new flux-based hybrid subcell-remapping algorithm for staggered multimaterial arbitrary Lagrangian-Eulerian (MMALE) methods is presented. This new method is an effective generalization of the original subcell-remapping method to the multi-material regime (LOUBERE, R. and SHASHKOV,M. A subcell remapping method on staggered polygonal grids for arbitrary-Lagrangian-Eulerian methods. Journal of Computational Physics, 209, 105–138 (2005)). A complete remapping procedure of all fluid quantities is described detailedly in this paper. In the pure material regions, remapping of mass and internal energy is performed by using the original subcell-remapping method. In the regions near the material interfaces, remapping of mass and internal energy is performed with the intersection-based fluxes where intersections are performed between the swept regions and pure material polygons in the Lagrangian mesh, and an approximate approach is then introduced for constructing the subcell mass fluxes. In remapping of the subcell momentum, the mass fluxes are used to construct the momentum fluxes by multiplying a reconstructed velocity in the swept region. The nodal velocity is then conservatively recovered. Some numerical examples simulated in the full MMALE regime and several purely cyclic remapping examples are presented to prove the properties of the remapping method.
文摘The ERA-Interim reanalysis wind based on the distance-weighted average remapping for studying the wind circulation in Nigeria is presented. The wind flow using this atmospheric model simulation is studied for identification of grid-tie electrification opportunities in different wind locations. A 10-year reanalysis wind speed components at a surface level of the planetary layer at 0.25° × 0.25° spatial resolution is obtained and remapped into a new horizontal wind field at a grid resolution of 0.125° × 0.125° covering longitudinal and latitudinal directions of 3.0 - 15.0°E and 15.0 - 3.0°N, respectively. Using the distance-weighted average technique, the remapped wind field at a new grid resolution of 0.125° × 0.125° is compared at different terrain elevations and approximated close to the actual wind field of the same resolution. To determine the suitability of the prevailing wind for small-scale energy conversion, the magnitude of wind flow across the remapped wind field is studied for a 10-year period. Analysis shows that northern regions of Nigeria have a fair wind potential for a stand-alone application based on the wind flow originated at Gulf of Guinea as well as Chad and Niger. Furthermore, hourly surface wind speed observations from 18 synoptic stations in Nigeria are obtained and compared with the bilinear interpolated wind stations. The reanalysis wind reflects the surface wind observations and proves that the prevailing wind in Nigeria is higher than the reanalysis wind projection obtained from gridded data at resolution of 0.125° × 0.125°. The sectorwise wind directions at each synoptic stations for a period of 10 years are presented.
