Soybean is a global principal source of edible plant oil. As more soybean oil-related quantitative trait loci(QTLs) have been located in the collective genome, it is urgent to establish a classification system for the...Soybean is a global principal source of edible plant oil. As more soybean oil-related quantitative trait loci(QTLs) have been located in the collective genome, it is urgent to establish a classification system for these distributed QTLs. A collinear platform may be useful to characterize and identify relationships among QTLs as well as aid in novel gene discovery. In this study, the collinearity MCScan X algorithm and collective soybean genomic information were used to construct collinearity blocks, to which soybean oil-related QTLs were mapped. The results demonstrated that 666 collinearity blocks were detected in the soybean genome across 20 chromosomes, and 521 collinearity relationships existed in 231 of the 242 effective soybean oil-related QTLs. This included 214 inclusion relationships and 307 intersecting relationships. Among them, the collinearity among QTLs that are related to soybean oil content was shown on a maximum of seven chromosomes and minimum of one chromosome, with the majority of QTLs having collinearity on two chromosomes. Using overlapping hotspot regions in the soybean oil QTLs with collinearity, we mined for novel oil content-related genes. Overall, we identified 23 putatively functional genes associated with oil content in soybean and annotated them using a number of annotation databases. Our findings provide a valuable framework for elucidating evolutionary relationships between soybean oil-related QTLs and lay a foundation for functional marker-assisted breeding relating to soybean oil content.展开更多
In time series literature, many authors have found out that multicollinearity and autocorrelation usually afflict time series data. In this paper, we compare the performances of classical VAR and Sims-Zha Bayesian VAR...In time series literature, many authors have found out that multicollinearity and autocorrelation usually afflict time series data. In this paper, we compare the performances of classical VAR and Sims-Zha Bayesian VAR models with quadratic decay on bivariate time series data jointly influenced by collinearity and autocorrelation. We simulate bivariate time series data for different collinearity levels (﹣0.99, ﹣0.95, ﹣0.9, ﹣0.85, ﹣0.8, 0.8, 0.85, 0.9, 0.95, 0.99) and autocorrelation levels (﹣0.99, ﹣0.95, ﹣0.9, ﹣0.85, ﹣0.8, 0.8, 0.85, 0.9, 0.95, 0.99) for time series length of 8, 16, 32, 64, 128, 256 respectively. The results from 10,000 simulations reveal that the models performance varies with the collinearity and autocorrelation levels, and with the time series lengths. In addition, the results reveal that the BVAR4 model is a viable model for forecasting. Therefore, we recommend that the levels of collinearity and autocorrelation, and the time series length should be considered in using an appropriate model for forecasting.展开更多
Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies...Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies of endmember fractions. Use of linear spectral mixture analysis (LSMA) can effectively reduce the degree of collinearity in the NSMA. However, the inadequate modeling of mixed spectra in the LSMA will also yield retrieval errors, especially for the cases where the multiple scattering is not ignorable. In this study, a generalized spectral unmixing scheme based on a spectral shape measure, i.e. spectral information divergence (SID), was applied to overcome the limitations of the conventional NSMA and LSMA. Two simulation experiments were undertaken to test the performances of the SID, LSMA and NSMA in the mixture cases of treesoil, tree-concrete and tree-grass. Results demonstrated that the SID yielded higher accuracies than the LSMA for almost all the mixture cases in this study. On the other hand, performances of the SID method were comparable with the NSMA for the tree-soil and tree-grass mixture cases, but significantly better than the NSMA for the tree-concrete mixture case. All the results indicate that the SID method is fairly effective to circumvent collinearity effect within the NSMA, and compensate the inadequate modeling of mixed spectra within the LSMA.展开更多
Plant genome sequencing has dramatically increased,and some species even have multiple high-quality reference versions.Demands for clade-specific homology inference and analysis have increased in the pangenomic era.He...Plant genome sequencing has dramatically increased,and some species even have multiple high-quality reference versions.Demands for clade-specific homology inference and analysis have increased in the pangenomic era.Here we present a novel method,GeneTribe(https://chenym1.github.io/genetribe/),for homology inference among genetically similar genomes that incorporates gene collinearity and shows bet-ter performance than traditional sequence-similarity-based methods in terms of accuracy and scalability.The Triticeae tribe is a typical allopolyploid-rich clade with complex species relationships that includes many important crops,such as wheat,barley,and rye.We built Triticeae-GeneTribe(http://wheat.cau.edu.cn/TGT/),a homology database,by integrating 12 Triticeae genomes and 3 outgroup model genomes and implemented versatile analysis and visualization functions.With macrocollinearity analysis,we were able to construct a refined model illustrating the structural rearrangements of the 4A-5A-7B chromosomes in wheat as two major translocation events.With collinearity analysis at both the macro-and microscale,we illustrated the complex evolutionary history of homologs of the wheat vernalization gene Vm2,which evolved as a combined result of genome translocation,duplication,and polyploidization and gene loss events.Our work provides a useful practice for connecting emerging genome assemblies,with awareness of the extensive polyploidy in plants,and will help researchers efficiently exploit genome sequence re-sources.展开更多
Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than t...Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient nanomanufacturing.However,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily submerged.Therefore,the formation mechanism of HSFL is complex and has always been a research hotspot in this field.In this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond laser.The ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging method.In general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is submerged.The results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL.展开更多
Harmonic nonlinear ultrasound can offer high sensitivity for residual stress measurements;however,it cannot be used for local stress measurements at a point in space and exhibits nonlinear distortions in the experimen...Harmonic nonlinear ultrasound can offer high sensitivity for residual stress measurements;however,it cannot be used for local stress measurements at a point in space and exhibits nonlinear distortions in the experimental system.This paper presents a feasibility study on the measurement of residual stress in a metal plate using a nonlinear Lamb wave-mixing technique.The resonant conditions for two Lamb waves to generate a mixing frequency wave are obtained via theoretical analysis.Finite element simulations are performed to investigate the nonlinear interactions between the two Lamb waves.Results show that two incident A0 waves interact in regions of material nonlinearity and generate a rightward S0 wave at the sum frequency.Residual stress measurement experiments are conducted on steel plate specimens using the collinear Lamb wave-mixing technique.By setting different delays for two transmitters,the generated sum-frequency component at different spatial locations is measured.Experimental results show that the spatial distribution of the amplitude of the sum-frequency component agrees well with the spatial distribution of the residual stress measured using X-rays.The proposed collinear Lamb wave-mixing method is effective for measuring the distribution of residual stress in metal plates.展开更多
A control and data acquisition system was implemented for the recently developed collinear laser spectroscopy setup.This system is dedicated to data recording,storage,processing,monitoring of the beam intensity and en...A control and data acquisition system was implemented for the recently developed collinear laser spectroscopy setup.This system is dedicated to data recording,storage,processing,monitoring of the beam intensity and energy,and visualization of various spectra.In comparison to the conventional resonance nuclear reaction system,the key technique is the precise synchronization of the detected counts with the actual scanning voltage(or probing laser frequency).The functions of the system were tested by measuring the hyperfine structure spectra of stable calcium(e.g.,^(40)Ca^(+))and radioactive potassium(e.g.,^(38)K)in the bunched and continuous modes,respectively.This system will be routinely applied and further improved in subsequent laser spectroscopy experiments on unstable isotopes at the Beijing Radioactive Ion-beam Facility(BRIF).展开更多
Cucumber is one of the most widely consumed vegetables worldwide,and the fruit spine is an important fruit quality trait.Expansins play critical roles in fruit development;however,the regulation of expansins in cucumb...Cucumber is one of the most widely consumed vegetables worldwide,and the fruit spine is an important fruit quality trait.Expansins play critical roles in fruit development;however,the regulation of expansins in cucumber fruit spine development has not been reported.In this study,33 expansin genes were identified in the cucumber genome V3;additionally,expansin genes in Citrullus lanatus,Cucumis melo,Cucurbita maxima,Lagenaria siceraria,and Benincasa hispida were also identified.Phylogenetic analysis of expansin proteins in Cucurbitaceae and Arabidopsis showed that they evolved separately in each plant species.Phylogenetic analysis showed that C.maxima was derived earlier than the other five Cucurbitaceae species.The expression of CsEXPA2,CsEXPA14,and CsEXLA3 varied in cucumber lines with different fruit spine densities.A yeast two-hybrid assay showed that a putative auxin transporter encoded by numerous spine gene(ns)interacts with CsEXLA2,which may be involved in the development of the numerous spines in cucumber.These results provide novel insights into the expansins related to plant development and fruit spine development in cucumber.展开更多
The solid template CCD camera calibration method of bundle adjustments basedon collinearity equation is presented considering the characteristics of space large-dimensionon-line measurement. In the method, a more comp...The solid template CCD camera calibration method of bundle adjustments basedon collinearity equation is presented considering the characteristics of space large-dimensionon-line measurement. In the method, a more comprehensive camera model is adopted which is based onthe pinhole model extended with distortions corrections. In the process of calibration, calibrationprecision is improved by imaging at different locations in the whole measurement space,multi-imaging at the same location and bundle adjustments optimization. The calibration experimentproves that the calibration method is able to fulfill calibration requirement of CCD camera appliedto vision measurement.展开更多
Camera calibration is a critical process in photogrammetry and a necessary step to acquire 3D information from a 2D image. In this paper, a flexible approach for CCD camera calibration using 2D direct linear transform...Camera calibration is a critical process in photogrammetry and a necessary step to acquire 3D information from a 2D image. In this paper, a flexible approach for CCD camera calibration using 2D direct linear transformation (DLT) and bundle adjustment is proposed. The proposed approach assumes that the camera interior orientation elements are known, and addresses a new closed form solution in planar object space based on homogenous coordinate representation and matrix factorization. Homogeneous coordinate representation offers a direct matrix correspondence between the parameters of the 2D DLT and the collinearity equation. The matrix factorization starts by recovering the elements of the rotation matrix and then solving for the camera position with the collinearity equation. Camera calibration with high precision is addressed by bundle adjustment using the initial values of the camera orientation elements. The results show that the calibration precision of principal point and focal length is about 0.2 and 0.3 pixels respectivelv, which can meet the requirements of close-range photogrammetry with high accuracy.展开更多
Background:INDETERMINATE DOMAIN(IDD)transcription factors form one of the largest and most conserved gene families in plant kingdom and play important roles in various processes of plant growth and development,such as...Background:INDETERMINATE DOMAIN(IDD)transcription factors form one of the largest and most conserved gene families in plant kingdom and play important roles in various processes of plant growth and development,such as flower induction in term of flowering control.Till date,systematic and functional analysis of IDD genes remained infancy in cotton.Results:In this study,we identified total of 162 IDD genes from eight different plant species including 65 IDD genes in Gossypium hirsutum.Phylogenetic analysis divided IDDs genes into seven well distinct groups.The gene structures and conserved motifs of GhIDD genes depicted highly conserved exon-intron and protein motif distribution patterns.Gene duplication analysis revealed that among 142 orthologous gene pairs,54 pairs have been derived by segmental duplication events and four pairs by tandem duplication events.Further,Ka/Ks values of most of orthologous/paralogous gene pairs were less than one suggested the purifying selection pressure during evolution.Spatiotemporal expression pattern by qRT-PCR revealed that most of the investigated GhIDD genes showed higher transcript levels in ovule of seven days post anthesis,and upregulated response under the treatments of multiple abiotic stresses.Conclusions:Evolutionary analysis revealed that IDD gene family was highly conserved in plant during the rapid phase of evolution.Whole genome duplication,segmental as well as tandem duplication significantly contributed to the expansion of IDD gene family in upland cotton.Some distinct genes evolved into special subfamily and indicated potential role in the allotetraploidy Gossypium hisutum evolution and development High transcript levels of GhIDD genes in ovules illustrated their potential roles in seed and fiber development Further,upregulated responses of GhIDD genes under the treatments of various abiotic stresses suggested them as important genetic regulators to improve stress resistance in cotton breeding.展开更多
ZAT(Zinc Finger of Arabidopsis thaliana)proteins are composed of a plant-specific transcription factor family,which play an important role in plant growth,development,and stress resista nee.To study the potential func...ZAT(Zinc Finger of Arabidopsis thaliana)proteins are composed of a plant-specific transcription factor family,which play an important role in plant growth,development,and stress resista nee.To study the potential function of ZAT family in cotton,the whole genome identification,expression,and structure analysis of ZAT gene family were carried out.In this study,our analysis revealed the presenee of 115Z 56,59,and 115 ZAT genes in Gossypium hirsutum,G raimondii,G.arboreum and G barbadense,respectively.According to the number of domains and phylogenetic characteristics,we divided ZAT genes of four Gossypium species into 4 different clades,and further divided them into 11 subfamilies.The results of collinearity an alysis showed that segmental duplicati on was the main method to amplify the cotton ZAT genes family.Analysis of c/s-elements of promoters indicated that most GhZAT genes contained c/5-elements related to plant hormones and abiotic stress.According to heatmap analysis,the expression patterns of GhZAT genes under different stresses indicated that GhZAT genes were significantly involved in the response to cold,heat,salt,and PEG stress,possibly through different mechanisms.Among the highly expressed genes,we cloned a G hirsutum gene GhZAT67.Through virus-induced gene silencing(VIGS),we found that its expression level decreased significantly after being sileneed.Under alkaline treatment,the wilting degree of silenced plants was even greater than the wild type,which proved that GhZAT67 gene was involved in the response to alkaline stress.展开更多
Demand for precise vehicle positioning(VP)increases as autonomous vehicles have recently been drawing attention.This paper proposes a scheme for positioning vehicles on the move based on optical camera communication(O...Demand for precise vehicle positioning(VP)increases as autonomous vehicles have recently been drawing attention.This paper proposes a scheme for positioning vehicles on the move based on optical camera communication(OCC)technology in the vehicle-to-infrastructure(V2I)environment.Light-emitting diode(LED)streetlights and vehicle cameras are used as transmitters and receivers respectively.Regions of streetlights are detected and traced by examining images that are obtained from cameras of vehicles.Then,a scheme for analyzing visible light data extracted from the images is proposed.The proposed vehicle positioning scheme uses information on angles between vectors that are formed under the collinearity conditions between the absolute coordinates of at least three received streetlights,and the coordinates of an image sensor.The experiments are performed under stationary state and moving state at a speed of 5 and 20 km/h.To verify the reliability of the proposed scheme,a comparison is made between the actual and estimated location of the camera in the stationary state.In addition,the path of a moving vehicle and the estimated path of the vehicle are compared to check the performance of the scheme.The performance of the proposed technique is analyzed and experimental demonstration confirms that the proposed OCC-based VP scheme achieves positioning accuracy of under 1 m.展开更多
Background:Under abiotic stress conditions,cotton growth is inhibited and yield losses are severe.Identification of calnexin family members and function analysis under abiotic stress laid the foundation for the screen...Background:Under abiotic stress conditions,cotton growth is inhibited and yield losses are severe.Identification of calnexin family members and function analysis under abiotic stress laid the foundation for the screening of stressrelated candidate genes.Results:A total of 60 CNX family members have been identified in Gossypium hirsutum,G.barbadense,G.arboreum,and G.raimondii,and they were divided into two categories:CNX and CRT genes.Through the construction of a phylogenetic tree,they were subdivided into three classes.Further analysis of chromosome localization,conserved promoters,gene structure and selection under pressure showed that the family members were highly conserved in the evolution process.Analysis of cis-acting elements in the promoter regions showed that CNX family genes contain regulatory elements for growth and development,anaerobic,drought,defense and stress response,and plant hormones.Using RNA-seq data to study the expression pattern of GhCNX genes under cold,hot,salt stress and Polyethylene glycol,it was observed that the gene expression levels changed by different degrees under different stress conditions,indicating that GhCNX members were involved in the regulation of multiple biological stresses.Conclusion:This study provides an insight into the members of cotton CNX genes.The results of this study suggested that CNX family members play a role in defense against adversity and provide a foundation for the discovery of stress-related genes.展开更多
Forecasts can either be short term, medium term or long term. In this work we considered short term forecast because of the problem of limited data or time series data that is often encounter in time series analysis. ...Forecasts can either be short term, medium term or long term. In this work we considered short term forecast because of the problem of limited data or time series data that is often encounter in time series analysis. This simulation study considered the performances of the classical VAR and Sims-Zha Bayesian VAR for short term series at different levels of collinearity and correlated error terms. The results from 10,000 iteration revealed that the BVAR models are excellent for time series length of T=8 for all levels of collinearity while the classical VAR is effective for time series length of T=16 for all collinearity levels except when ρ = -0.9 and ρ = -0.95. We therefore recommended that for effective short term forecasting, the time series length, forecasting horizon and the collinearity level should be considered.展开更多
Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the gen...Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the genome quality rapidly and efficiently.Methods:We performed Hi-C sequencing of G.raimondii and reassembled its genome based on a set of new Hi-C data and previously published scaffolds.We also compared the reassembled genome sequenee with the previously published G raimondii genomes for gene and genome sequence collinearity.Result:A total of 9842%of scaffold sequences were clustered successfully,among which 99.72%of the clustered sequences were ordered and 99.92%of the ordered sequences were oriented with high-quality.Further evaluation of results by heat-map and collinearity analysis revealed that the current reassembled genome is significantly improved than the previous one(Nat Genet 44:98-1103,2012).Conclusion:This improvement in G raimondii genome not only provides a better reference to increase study efficiency but also offers a new way to assemble cotton genomes.Furthermore,Hi-C data of G.raimondii may be used for 3D structure research or regulating analysis.展开更多
Spatial variations in temperature may be ascribed to many variables. Among these, variables pertaining to topography are prominent. Thus various topographic variables were calculated from 50 m-resolution digital terra...Spatial variations in temperature may be ascribed to many variables. Among these, variables pertaining to topography are prominent. Thus various topographic variables were calculated from 50 m-resolution digital terrain models (DTMs) for three study areas in France and for Slovenia. The “classic” geomatic variables (altitude, aspect, gradient, etc.) are supplemented by the description of landforms (amplitude of humps and hollows). Special care is taken in managing collinearity among variables and building windows with different dimensions. Statistical processing involves linear regressions of daily temperatures taken as the response variables and six topographic variables (explanatory variables). Altitude accounts significantly for the spatial variation in temperatures in 90% of cases, except in the Gironde, a lowlying area (50%). The scale of landforms also appears to be highly correlated to the measured temperature. Variations in the frequency with which topographic descriptors account for temperatures are examined from several standpoints. Altitude is less frequently taken as an explanatory variable for spatial variation of temperatures in winter (75%) than in spring (80%) and late summer (85%). Minimum temperatures are influenced on average much more by the amplitude of humps and hollows (56%) than maximum temperatures (38%) are. The frequency with which these two landforms account for the spatial variation of temperature is reversed between the minima and maxima.展开更多
Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solv...Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solved, and the exact analytic solutions of the stress intensity factors (SIFs) for mode Ⅲ problem are obtained. Under the limiting conditions, the present results reduce to the Griffith crack and many new results obtained as well, such as the circular hole with asymmetric collinear cracks, the elliptic hole with a straight crack, the mode T crack, the cross crack and so on. As far as the phonon field is concerned, these results, which play an important role in many practical and theoretical applications, are shown to be in good agreement with the classical results.展开更多
Collinear laser spectroscopy is a powerful tool for studying the nuclear spins,electromagnetic moments,and charge radii of exotic nuclei.To study the nuclear properties of unstable nuclei at the Beijing Radioactive Io...Collinear laser spectroscopy is a powerful tool for studying the nuclear spins,electromagnetic moments,and charge radii of exotic nuclei.To study the nuclear properties of unstable nuclei at the Beijing Radioactive Ion-beam Facility(BRIF)and the future High Intensity Heavy-ion Accelerator Facility(HIAF),we developed a collinear laser spectroscopy apparatus integrated with an offline laser ablation ion source and a laser system.The overall performance of this state-of-the-art technique was evaluated,and the system was commissioned using a bunched stable ion beam.The high-resolution optical spectra for the 4s ^(2)S_(1/2)→4p^(2)P_(3/2)(D2)ionic transition of ^(40;42;44;48)Ca isotopes were successfully measured.The extracted isotope shifts relative to ^(40)Ca showed excellent agreement with the literature values.This system is now ready for use at radioactive ion beam facilities such as the BRIF and paves the way for the further development of higher-sensitivity collinear resonance ionization spectroscopy techniques.展开更多
The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets ...The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.展开更多
基金financially supported by the National Key R&D Program of China (2016YFD0100500, 2016YFD0100300, 2016YFD0100201-21)the National Natural Science Foundation of China (31701449, 31471516, 31401465, 31400074, 31501332)+7 种基金the Natural Science Foundation of Heilongjiang Province, China (QC2017013)the Young Innovative Talent Training Plan of Undergraduate Colleges and Universities in Heilongjiang Province, China (UNPYSCT-2016144)the Special Financial Aid to Postdoctor Research Fellow in Heilongjiang, China (To Qi Zhaoming)the Heilongjiang Funds for Distinguished Young Scientists, China (JC2016004)the Outstanding Academic Leaders Projects of Harbin, China (2015RQXXJ018)the China Post Doctoral Project (2015M581419)the Dongnongxuezhe Project, China (to Chen Qingshan)the Young Talent Project of Northeast Agricultural University, China (to Qi Zhaoming, 518062)
文摘Soybean is a global principal source of edible plant oil. As more soybean oil-related quantitative trait loci(QTLs) have been located in the collective genome, it is urgent to establish a classification system for these distributed QTLs. A collinear platform may be useful to characterize and identify relationships among QTLs as well as aid in novel gene discovery. In this study, the collinearity MCScan X algorithm and collective soybean genomic information were used to construct collinearity blocks, to which soybean oil-related QTLs were mapped. The results demonstrated that 666 collinearity blocks were detected in the soybean genome across 20 chromosomes, and 521 collinearity relationships existed in 231 of the 242 effective soybean oil-related QTLs. This included 214 inclusion relationships and 307 intersecting relationships. Among them, the collinearity among QTLs that are related to soybean oil content was shown on a maximum of seven chromosomes and minimum of one chromosome, with the majority of QTLs having collinearity on two chromosomes. Using overlapping hotspot regions in the soybean oil QTLs with collinearity, we mined for novel oil content-related genes. Overall, we identified 23 putatively functional genes associated with oil content in soybean and annotated them using a number of annotation databases. Our findings provide a valuable framework for elucidating evolutionary relationships between soybean oil-related QTLs and lay a foundation for functional marker-assisted breeding relating to soybean oil content.
文摘In time series literature, many authors have found out that multicollinearity and autocorrelation usually afflict time series data. In this paper, we compare the performances of classical VAR and Sims-Zha Bayesian VAR models with quadratic decay on bivariate time series data jointly influenced by collinearity and autocorrelation. We simulate bivariate time series data for different collinearity levels (﹣0.99, ﹣0.95, ﹣0.9, ﹣0.85, ﹣0.8, 0.8, 0.85, 0.9, 0.95, 0.99) and autocorrelation levels (﹣0.99, ﹣0.95, ﹣0.9, ﹣0.85, ﹣0.8, 0.8, 0.85, 0.9, 0.95, 0.99) for time series length of 8, 16, 32, 64, 128, 256 respectively. The results from 10,000 simulations reveal that the models performance varies with the collinearity and autocorrelation levels, and with the time series lengths. In addition, the results reveal that the BVAR4 model is a viable model for forecasting. Therefore, we recommend that the levels of collinearity and autocorrelation, and the time series length should be considered in using an appropriate model for forecasting.
文摘Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies of endmember fractions. Use of linear spectral mixture analysis (LSMA) can effectively reduce the degree of collinearity in the NSMA. However, the inadequate modeling of mixed spectra in the LSMA will also yield retrieval errors, especially for the cases where the multiple scattering is not ignorable. In this study, a generalized spectral unmixing scheme based on a spectral shape measure, i.e. spectral information divergence (SID), was applied to overcome the limitations of the conventional NSMA and LSMA. Two simulation experiments were undertaken to test the performances of the SID, LSMA and NSMA in the mixture cases of treesoil, tree-concrete and tree-grass. Results demonstrated that the SID yielded higher accuracies than the LSMA for almost all the mixture cases in this study. On the other hand, performances of the SID method were comparable with the NSMA for the tree-soil and tree-grass mixture cases, but significantly better than the NSMA for the tree-concrete mixture case. All the results indicate that the SID method is fairly effective to circumvent collinearity effect within the NSMA, and compensate the inadequate modeling of mixed spectra within the LSMA.
基金the Major Program of the National Natural Science Foundation of China(grant no.31991210)to Q.S.and by the National Natural Science Foundation of China(grant no.31701415)to W.G.
文摘Plant genome sequencing has dramatically increased,and some species even have multiple high-quality reference versions.Demands for clade-specific homology inference and analysis have increased in the pangenomic era.Here we present a novel method,GeneTribe(https://chenym1.github.io/genetribe/),for homology inference among genetically similar genomes that incorporates gene collinearity and shows bet-ter performance than traditional sequence-similarity-based methods in terms of accuracy and scalability.The Triticeae tribe is a typical allopolyploid-rich clade with complex species relationships that includes many important crops,such as wheat,barley,and rye.We built Triticeae-GeneTribe(http://wheat.cau.edu.cn/TGT/),a homology database,by integrating 12 Triticeae genomes and 3 outgroup model genomes and implemented versatile analysis and visualization functions.With macrocollinearity analysis,we were able to construct a refined model illustrating the structural rearrangements of the 4A-5A-7B chromosomes in wheat as two major translocation events.With collinearity analysis at both the macro-and microscale,we illustrated the complex evolutionary history of homologs of the wheat vernalization gene Vm2,which evolved as a combined result of genome translocation,duplication,and polyploidization and gene loss events.Our work provides a useful practice for connecting emerging genome assemblies,with awareness of the extensive polyploidy in plants,and will help researchers efficiently exploit genome sequence re-sources.
基金supports from the National Natural Science Foundation of China(12074123,12174108)the Foundation of‘Manufacturing beyond limits’of Shanghai‘Talent Program'of Henan Academy of Sciences.
文摘Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient nanomanufacturing.However,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily submerged.Therefore,the formation mechanism of HSFL is complex and has always been a research hotspot in this field.In this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond laser.The ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging method.In general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is submerged.The results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL.
基金National Natural Science Foundation of China(Grant Nos.11972053,12274012)。
文摘Harmonic nonlinear ultrasound can offer high sensitivity for residual stress measurements;however,it cannot be used for local stress measurements at a point in space and exhibits nonlinear distortions in the experimental system.This paper presents a feasibility study on the measurement of residual stress in a metal plate using a nonlinear Lamb wave-mixing technique.The resonant conditions for two Lamb waves to generate a mixing frequency wave are obtained via theoretical analysis.Finite element simulations are performed to investigate the nonlinear interactions between the two Lamb waves.Results show that two incident A0 waves interact in regions of material nonlinearity and generate a rightward S0 wave at the sum frequency.Residual stress measurement experiments are conducted on steel plate specimens using the collinear Lamb wave-mixing technique.By setting different delays for two transmitters,the generated sum-frequency component at different spatial locations is measured.Experimental results show that the spatial distribution of the amplitude of the sum-frequency component agrees well with the spatial distribution of the residual stress measured using X-rays.The proposed collinear Lamb wave-mixing method is effective for measuring the distribution of residual stress in metal plates.
基金supported by the National Natural Science Foundation of China (Nos.12027809,U1967201,11875073,11875074 and 11961141003)National Key R&D Program of China (No.2018YFA0404403)the State Key Laboratory of Nuclear Physics and Technology,Peking University (Nos.NPT2019ZZ02,NPT2020KFY17).
文摘A control and data acquisition system was implemented for the recently developed collinear laser spectroscopy setup.This system is dedicated to data recording,storage,processing,monitoring of the beam intensity and energy,and visualization of various spectra.In comparison to the conventional resonance nuclear reaction system,the key technique is the precise synchronization of the detected counts with the actual scanning voltage(or probing laser frequency).The functions of the system were tested by measuring the hyperfine structure spectra of stable calcium(e.g.,^(40)Ca^(+))and radioactive potassium(e.g.,^(38)K)in the bunched and continuous modes,respectively.This system will be routinely applied and further improved in subsequent laser spectroscopy experiments on unstable isotopes at the Beijing Radioactive Ion-beam Facility(BRIF).
基金supported by the earmarked fund for Modern Agro-industry Technology Research System (CARS-23)the National Natural Science Foundation of China (31672172)+1 种基金The Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-IVFCAAS)the Key Laboratory of Biology and Genetic Improvement of Horticultural Crops,Ministry of Agriculture and Rural Affairs,China。
文摘Cucumber is one of the most widely consumed vegetables worldwide,and the fruit spine is an important fruit quality trait.Expansins play critical roles in fruit development;however,the regulation of expansins in cucumber fruit spine development has not been reported.In this study,33 expansin genes were identified in the cucumber genome V3;additionally,expansin genes in Citrullus lanatus,Cucumis melo,Cucurbita maxima,Lagenaria siceraria,and Benincasa hispida were also identified.Phylogenetic analysis of expansin proteins in Cucurbitaceae and Arabidopsis showed that they evolved separately in each plant species.Phylogenetic analysis showed that C.maxima was derived earlier than the other five Cucurbitaceae species.The expression of CsEXPA2,CsEXPA14,and CsEXLA3 varied in cucumber lines with different fruit spine densities.A yeast two-hybrid assay showed that a putative auxin transporter encoded by numerous spine gene(ns)interacts with CsEXLA2,which may be involved in the development of the numerous spines in cucumber.These results provide novel insights into the expansins related to plant development and fruit spine development in cucumber.
文摘The solid template CCD camera calibration method of bundle adjustments basedon collinearity equation is presented considering the characteristics of space large-dimensionon-line measurement. In the method, a more comprehensive camera model is adopted which is based onthe pinhole model extended with distortions corrections. In the process of calibration, calibrationprecision is improved by imaging at different locations in the whole measurement space,multi-imaging at the same location and bundle adjustments optimization. The calibration experimentproves that the calibration method is able to fulfill calibration requirement of CCD camera appliedto vision measurement.
基金Project 2005A030 supported by the Youth Science and Research Foundation from China University of Mining & Technology
文摘Camera calibration is a critical process in photogrammetry and a necessary step to acquire 3D information from a 2D image. In this paper, a flexible approach for CCD camera calibration using 2D direct linear transformation (DLT) and bundle adjustment is proposed. The proposed approach assumes that the camera interior orientation elements are known, and addresses a new closed form solution in planar object space based on homogenous coordinate representation and matrix factorization. Homogeneous coordinate representation offers a direct matrix correspondence between the parameters of the 2D DLT and the collinearity equation. The matrix factorization starts by recovering the elements of the rotation matrix and then solving for the camera position with the collinearity equation. Camera calibration with high precision is addressed by bundle adjustment using the initial values of the camera orientation elements. The results show that the calibration precision of principal point and focal length is about 0.2 and 0.3 pixels respectivelv, which can meet the requirements of close-range photogrammetry with high accuracy.
基金supported by the Major Research Plan of National Natural Science Foundation of China(NO.31690093)Creative Research Groups of China(31621005)the Agricultural Science and Technology Innovation Program Cooperation and Innovation Mission(CAAS-XTCX2016)
文摘Background:INDETERMINATE DOMAIN(IDD)transcription factors form one of the largest and most conserved gene families in plant kingdom and play important roles in various processes of plant growth and development,such as flower induction in term of flowering control.Till date,systematic and functional analysis of IDD genes remained infancy in cotton.Results:In this study,we identified total of 162 IDD genes from eight different plant species including 65 IDD genes in Gossypium hirsutum.Phylogenetic analysis divided IDDs genes into seven well distinct groups.The gene structures and conserved motifs of GhIDD genes depicted highly conserved exon-intron and protein motif distribution patterns.Gene duplication analysis revealed that among 142 orthologous gene pairs,54 pairs have been derived by segmental duplication events and four pairs by tandem duplication events.Further,Ka/Ks values of most of orthologous/paralogous gene pairs were less than one suggested the purifying selection pressure during evolution.Spatiotemporal expression pattern by qRT-PCR revealed that most of the investigated GhIDD genes showed higher transcript levels in ovule of seven days post anthesis,and upregulated response under the treatments of multiple abiotic stresses.Conclusions:Evolutionary analysis revealed that IDD gene family was highly conserved in plant during the rapid phase of evolution.Whole genome duplication,segmental as well as tandem duplication significantly contributed to the expansion of IDD gene family in upland cotton.Some distinct genes evolved into special subfamily and indicated potential role in the allotetraploidy Gossypium hisutum evolution and development High transcript levels of GhIDD genes in ovules illustrated their potential roles in seed and fiber development Further,upregulated responses of GhIDD genes under the treatments of various abiotic stresses suggested them as important genetic regulators to improve stress resistance in cotton breeding.
基金Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences.The funding bodies provided financial support to the research projects but didn't involve in study design,data collection,analysis,or preparation of the manuscript.
文摘ZAT(Zinc Finger of Arabidopsis thaliana)proteins are composed of a plant-specific transcription factor family,which play an important role in plant growth,development,and stress resista nee.To study the potential function of ZAT family in cotton,the whole genome identification,expression,and structure analysis of ZAT gene family were carried out.In this study,our analysis revealed the presenee of 115Z 56,59,and 115 ZAT genes in Gossypium hirsutum,G raimondii,G.arboreum and G barbadense,respectively.According to the number of domains and phylogenetic characteristics,we divided ZAT genes of four Gossypium species into 4 different clades,and further divided them into 11 subfamilies.The results of collinearity an alysis showed that segmental duplicati on was the main method to amplify the cotton ZAT genes family.Analysis of c/s-elements of promoters indicated that most GhZAT genes contained c/5-elements related to plant hormones and abiotic stress.According to heatmap analysis,the expression patterns of GhZAT genes under different stresses indicated that GhZAT genes were significantly involved in the response to cold,heat,salt,and PEG stress,possibly through different mechanisms.Among the highly expressed genes,we cloned a G hirsutum gene GhZAT67.Through virus-induced gene silencing(VIGS),we found that its expression level decreased significantly after being sileneed.Under alkaline treatment,the wilting degree of silenced plants was even greater than the wild type,which proved that GhZAT67 gene was involved in the response to alkaline stress.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(NRF-2018R1A2B6002204).
文摘Demand for precise vehicle positioning(VP)increases as autonomous vehicles have recently been drawing attention.This paper proposes a scheme for positioning vehicles on the move based on optical camera communication(OCC)technology in the vehicle-to-infrastructure(V2I)environment.Light-emitting diode(LED)streetlights and vehicle cameras are used as transmitters and receivers respectively.Regions of streetlights are detected and traced by examining images that are obtained from cameras of vehicles.Then,a scheme for analyzing visible light data extracted from the images is proposed.The proposed vehicle positioning scheme uses information on angles between vectors that are formed under the collinearity conditions between the absolute coordinates of at least three received streetlights,and the coordinates of an image sensor.The experiments are performed under stationary state and moving state at a speed of 5 and 20 km/h.To verify the reliability of the proposed scheme,a comparison is made between the actual and estimated location of the camera in the stationary state.In addition,the path of a moving vehicle and the estimated path of the vehicle are compared to check the performance of the scheme.The performance of the proposed technique is analyzed and experimental demonstration confirms that the proposed OCC-based VP scheme achieves positioning accuracy of under 1 m.
基金supported by the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences,and Supported by China Agriculture Research System of MOF and MARA.
文摘Background:Under abiotic stress conditions,cotton growth is inhibited and yield losses are severe.Identification of calnexin family members and function analysis under abiotic stress laid the foundation for the screening of stressrelated candidate genes.Results:A total of 60 CNX family members have been identified in Gossypium hirsutum,G.barbadense,G.arboreum,and G.raimondii,and they were divided into two categories:CNX and CRT genes.Through the construction of a phylogenetic tree,they were subdivided into three classes.Further analysis of chromosome localization,conserved promoters,gene structure and selection under pressure showed that the family members were highly conserved in the evolution process.Analysis of cis-acting elements in the promoter regions showed that CNX family genes contain regulatory elements for growth and development,anaerobic,drought,defense and stress response,and plant hormones.Using RNA-seq data to study the expression pattern of GhCNX genes under cold,hot,salt stress and Polyethylene glycol,it was observed that the gene expression levels changed by different degrees under different stress conditions,indicating that GhCNX members were involved in the regulation of multiple biological stresses.Conclusion:This study provides an insight into the members of cotton CNX genes.The results of this study suggested that CNX family members play a role in defense against adversity and provide a foundation for the discovery of stress-related genes.
文摘Forecasts can either be short term, medium term or long term. In this work we considered short term forecast because of the problem of limited data or time series data that is often encounter in time series analysis. This simulation study considered the performances of the classical VAR and Sims-Zha Bayesian VAR for short term series at different levels of collinearity and correlated error terms. The results from 10,000 iteration revealed that the BVAR models are excellent for time series length of T=8 for all levels of collinearity while the classical VAR is effective for time series length of T=16 for all collinearity levels except when ρ = -0.9 and ρ = -0.95. We therefore recommended that for effective short term forecasting, the time series length, forecasting horizon and the collinearity level should be considered.
文摘Introduction:Genome sequence plays an important role in both basic and applied studies.Gossypium raimondii,the putative contributor of the D subgenome of upland cotton(G.hirsutum,highlights the need to improve the genome quality rapidly and efficiently.Methods:We performed Hi-C sequencing of G.raimondii and reassembled its genome based on a set of new Hi-C data and previously published scaffolds.We also compared the reassembled genome sequenee with the previously published G raimondii genomes for gene and genome sequence collinearity.Result:A total of 9842%of scaffold sequences were clustered successfully,among which 99.72%of the clustered sequences were ordered and 99.92%of the ordered sequences were oriented with high-quality.Further evaluation of results by heat-map and collinearity analysis revealed that the current reassembled genome is significantly improved than the previous one(Nat Genet 44:98-1103,2012).Conclusion:This improvement in G raimondii genome not only provides a better reference to increase study efficiency but also offers a new way to assemble cotton genomes.Furthermore,Hi-C data of G.raimondii may be used for 3D structure research or regulating analysis.
文摘Spatial variations in temperature may be ascribed to many variables. Among these, variables pertaining to topography are prominent. Thus various topographic variables were calculated from 50 m-resolution digital terrain models (DTMs) for three study areas in France and for Slovenia. The “classic” geomatic variables (altitude, aspect, gradient, etc.) are supplemented by the description of landforms (amplitude of humps and hollows). Special care is taken in managing collinearity among variables and building windows with different dimensions. Statistical processing involves linear regressions of daily temperatures taken as the response variables and six topographic variables (explanatory variables). Altitude accounts significantly for the spatial variation in temperatures in 90% of cases, except in the Gironde, a lowlying area (50%). The scale of landforms also appears to be highly correlated to the measured temperature. Variations in the frequency with which topographic descriptors account for temperatures are examined from several standpoints. Altitude is less frequently taken as an explanatory variable for spatial variation of temperatures in winter (75%) than in spring (80%) and late summer (85%). Minimum temperatures are influenced on average much more by the amplitude of humps and hollows (56%) than maximum temperatures (38%) are. The frequency with which these two landforms account for the spatial variation of temperature is reversed between the minima and maxima.
基金supported by the National Natural Science Foundation of China (Grant No 10761005)the Inner Mongolia Natural Science Foundation of China (Grant No 200607010104)
文摘Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solved, and the exact analytic solutions of the stress intensity factors (SIFs) for mode Ⅲ problem are obtained. Under the limiting conditions, the present results reduce to the Griffith crack and many new results obtained as well, such as the circular hole with asymmetric collinear cracks, the elliptic hole with a straight crack, the mode T crack, the cross crack and so on. As far as the phonon field is concerned, these results, which play an important role in many practical and theoretical applications, are shown to be in good agreement with the classical results.
基金supported by the National Natural Science Foundation of China(Nos.12027809,U1967201,11875073,11875074 and 11961141003)National Key R&D Program of China(No.2018YFA0404403)+1 种基金China National Nuclear Corporation(No.FA18000201)the State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2019ZZ02).
文摘Collinear laser spectroscopy is a powerful tool for studying the nuclear spins,electromagnetic moments,and charge radii of exotic nuclei.To study the nuclear properties of unstable nuclei at the Beijing Radioactive Ion-beam Facility(BRIF)and the future High Intensity Heavy-ion Accelerator Facility(HIAF),we developed a collinear laser spectroscopy apparatus integrated with an offline laser ablation ion source and a laser system.The overall performance of this state-of-the-art technique was evaluated,and the system was commissioned using a bunched stable ion beam.The high-resolution optical spectra for the 4s ^(2)S_(1/2)→4p^(2)P_(3/2)(D2)ionic transition of ^(40;42;44;48)Ca isotopes were successfully measured.The extracted isotope shifts relative to ^(40)Ca showed excellent agreement with the literature values.This system is now ready for use at radioactive ion beam facilities such as the BRIF and paves the way for the further development of higher-sensitivity collinear resonance ionization spectroscopy techniques.
文摘The principle and accuracy of 3-D coordinates acquisition using one single camera and the Aided Measuring Probe(AMP) are discussed in this paper. Using one single camera and one AMP which has several embedded targets and one tip with known coordinates, the single camera′s orientation and location can be calculated. After orientation, the global coordinate system is obtained. During measurement, the camera is fixed firstly, then the AMP is held and the feature point is touched.The camera is triggered lastly. The position and orientation of the AMP are therefore calculated from the size and position of its image on the sensor. Since the tip point of AMP has known relation with the embedded targets, the feature point can be measured. Tests show that the accuracy of length measurement is 0.2 mm and accuracy for flatness measurement in XSY-plane is 0.1 mm.