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Divergences in Perceptions as for Oral Activity in Morocco
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作者 Sana SAKALE 《Sino-US English Teaching》 2018年第1期8-13,共6页
This article tries to find out the few discrepancies between the teachers and their scholars as to oral activity, which shows that scholars' expectations and needs are not quite responded to. The versions chosen as a... This article tries to find out the few discrepancies between the teachers and their scholars as to oral activity, which shows that scholars' expectations and needs are not quite responded to. The versions chosen as a sample for this study come from different schools in the academy of Rabat Sal~ Zemmour Zaer area and belong to three different educational levels including common core, first year, and second year in addition to a total number of 40 teachers who have contributed to this research throughout the whole process. This research has relied on different instruments to collect the data including questionnaires, interviews, and class observation grids. Results showed that scholars' perceptions highly favour thematic variety. Findings also reported match findings of previous research in highlighting the importance of using tech facilities and multimedia to improve oral activity. 展开更多
关键词 different educational levels divergences in dealing with oral activity expectations PERCEPTIONS
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Allele-specific expression analyses reveal immune divergences between ibex and goat species
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作者 Zhi-Rui Yang Jia-Xin Li +12 位作者 Zhu-Qing Zheng Chen Zhao Yu Wang Ming Li Hojjat Asadollahpour Nanaei Xue-Lei Dai Yun-Jia Li Ran Li Chun-Na Cao Mao Li Yu Jiang Wen-Xin Zheng Xi-Hong Wang 《Zoological Research》 SCIE CAS CSCD 2022年第4期671-674,共4页
DEAR EDITOR,Understanding the different immune responses of wild and domestic caprid species is critical for addressing certain zoonotic diseases.In this study,we generated blood transcriptomes of 13 Siberian ibex and... DEAR EDITOR,Understanding the different immune responses of wild and domestic caprid species is critical for addressing certain zoonotic diseases.In this study,we generated blood transcriptomes of 13 Siberian ibex and domestic goat hybrids and performed allele-specific expression and splicing analyses.Results showed that genes exhibiting significant imbalance between the ibex and goat were highly related to the Toll-like receptor(TLR),antigen recognition,and immune activation pathways.Comparative genomic analysis of the species revealed that immune function-related genes were under strong selection pressure in the domestic goat. 展开更多
关键词 IMMUNE ALLELE divergence
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Genetically-and environmentally-dependent processes drive interspecific and intraspecific divergence in the Chinese relict endemic genus Dipteronia
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作者 Tao Zhou Xiaodan Chen +6 位作者 Jordi López-Pujol Guoqing Bai Sonia Herrando-Moraira Neus Nualart Xiao Zhang Yuemei Zhao Guifang Zhao 《Plant Diversity》 SCIE CAS CSCD 2024年第5期585-599,共15页
China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of ce... China is a hotspot of relict plant species that were once widespread throughout the Northern Hemisphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of central and south-western China allowed their persistence through the late Neogene climate fluctuations.One of these relict lineages is Dipteronia,an oligotypic tree genus with a fossil record extending to the Paleocene.Here,we investigated the genetic variability,demographic dynamics and diversification patterns of the two currently recognized Dipteronia species(Dipteronia sinensis and D.dyeriana).Molecular data were obtained from 45 populations of Dipteronia by genotyping three cpDNA regions,two single copy nuclear genes and 15 simple sequence repeat loci.The genetic study was combined with niche comparison analyses on the environmental space,ecological niche modeling,and landscape connectivity analysis.We found that the two Dipteronia species have highly diverged both in genetic and ecological terms.Despite the incipient speciation processes that can be observed in D.sinensis,the occurrence of long-term stable refugia and,particularly,a dispersal corridor along Daba Shan-west Qinling,likely ensured its genetic and ecological integrity to date.Our study will not only help us to understand how populations of Dipteronia species responded to the tectonic and climatic changes of the Cenozoic,but also provide insight into how Arcto-Tertiary relict plants in East Asia survived,evolved,and diversified. 展开更多
关键词 Dipteronia Interspecific/intraspecific divergence Genetic structure Climatic niche divergence Dispersal corridor
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A new species of Discostella guiyangensis sp.nov.(Bacillariophyta,Stephanodiscales)from Guiyang,China:morphology and phylogeny
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作者 Yandan XIANG Fangru NAN +3 位作者 Xudong LIU Shulian XIE John Patrick KOCIOLEK Qi LIU 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第4期1312-1324,共13页
We describe a new species of Discostella from Guiyang based on light and scanning electron microscopic observations,as well as molecular analysis.This species is morphologically distinguished from other species by a r... We describe a new species of Discostella from Guiyang based on light and scanning electron microscopic observations,as well as molecular analysis.This species is morphologically distinguished from other species by a relatively smooth and slightly recessed central area with marginal striae of unequal lengths forked near the margin.Marginal fultoportulae and a single rimoportula are situated between every two costae or on the costae.Both morphological characters and the concatenated data of rbc L and SSU rDNA indicate that Discostella guiyangensis is a unique and new species.According to divergence time estimation analysis,Discostella guiyangensis is the oldest species among the Discostella species sequenced currently.In addition,we complement molecular data of Discostella asterocostata and Discostella stelligera. 展开更多
关键词 Discostella MORPHOLOGY molecular analysis divergence time estimation new species
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Influence of Transportation Accessibility on Urban-rural Income Disparity and Its Spatial Heterogeneity
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作者 HUANG Xiaoyan KANG Chenchen +1 位作者 YIN Chun TANG Junqing 《Chinese Geographical Science》 SCIE CSCD 2024年第3期453-467,共15页
Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility ... Transportation accessibility has been treated as an important means of reducing the urban-rural income disparity.However,only a few studies have examined the effects of different types of transportation accessibility on urban-rural income disparity and their spatial heterogeneity.Based on data from 285 prefecture-level(and above)Chinese cities in 2000,2005,2010,2015,and 2020,this study uses spatial econometric models to examine how highway accessibility and railway accessibility influence the urban-rural income disparity and to identify their spatial heterogeneity.The result reveals that highway accessibility and railway accessibility have‘coreperiphery’ring-like circle structures.The urban-rural income disparity exhibits strong spatial clustering effects.Both highway accessibility and railway accessibility are negatively associated with urban-rural income disparity,and the former having a greater effect size.Moreover,there is a substitution effect between highway accessibility and railway accessibility in the whole sample.Furthermore,these associations differ in geographic regions.In the central region,highway accessibility is more important in reducing the urban-rural income disparity,but its effect is weakened with the increase of railway accessibility.In the western region,railway accessibility has a larger effect on narrowing the urban-rural income disparity,and this effect is strengthened by the increase of highway accessibility.We conclude that improving transportation accessibility is conducive to reducing the urban-rural income disparity but its effect is spatial heterogenetic.Highways and railways should be developed in a coordinated manner to promote an integrated transport network system. 展开更多
关键词 transport accessibility income gap regional divergence spatial heterogeneity urban and rural areas China
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ELLIPTIC EQUATIONS IN DIVERGENCE FORM WITH DISCONTINUOUS COEFFICIENTS IN DOMAINS WITH CORNERS
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作者 Jun CHEN Xuemei DENG 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1903-1915,共13页
We study equations in divergence form with piecewise Cαcoefficients.The domains contain corners and the discontinuity surfaces are attached to the edges of the corners.We obtain piecewise C^(1,α) estimates across th... We study equations in divergence form with piecewise Cαcoefficients.The domains contain corners and the discontinuity surfaces are attached to the edges of the corners.We obtain piecewise C^(1,α) estimates across the discontinuity surfaces and provide an example to illustrate the issue regarding the regularity at the corners. 展开更多
关键词 elliptic equations divergence form discontinuous coefficients corner regularity
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Four-to Six-Year Periodic Variation of Arctic Sea-Ice Extent and Its Three Main Driving Factors
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作者 Ping CHEN Jinping ZHAO Xiaoyu WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第10期1999-2010,共12页
Besides the rapid retreating trend of Arctic sea-ice extent(SIE),this study found the most outstanding low-frequency variation of SIE to be a 4-6-year periodic variation.Using a clustering analysis algorithm,the SIE i... Besides the rapid retreating trend of Arctic sea-ice extent(SIE),this study found the most outstanding low-frequency variation of SIE to be a 4-6-year periodic variation.Using a clustering analysis algorithm,the SIE in most ice-covered regions was clustered into two special regions:Region-1 around the Barents Sea and Region-2 around the Canadian Basin,which were located on either side of the Arctic Transpolar Drift.Clear 4-6-year periodic variation in these two regions was identified using a novel method called“running linear fitting algorithm”.The rate of temporal variation of the Arctic SIE was related to three driving factors:the regional air temperature,the sea-ice areal flux across the Arctic Transpolar Drift,and the divergence of sea-ice drift.The 4-6-year periodic variation was found to have always been present since 1979,but the SIE responded to different factors under heavy and light ice conditions divided by the year 2005.The joint contribution of the three factors to SIE variation exceeded 83%and 59%in the two regions,respectively,remarkably reflecting their dynamic mechanism.It is proven that the process of El Niño-Southern Oscillation(ENSO)is closely associated with the three factors,being the fundamental source of the 4-6-year periodic variations of Arctic SIE. 展开更多
关键词 sea-ice extent periodic variation air temperature sea-ice areal flux Arctic Transpolar Drift ice-drift divergence ENSO
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Geographical Variation in the Advertisement Calls of Leptobrachella ventripunctata(Anura:Megophryidae)in Southwestern China
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作者 Chaobo FENG Tuo SHEN +4 位作者 Lang MU Jing LIU Shize LI Yixin DIAO Haijun SU 《Asian Herpetological Research》 SCIE CSCD 2024年第3期140-151,共12页
In anurans,advertisement calls(ACs)are an essential form of intraspecific communication.This study evaluates geographical variation in the ACs of Leptobrachella ventripunctata in the Guizhou Plateau,southwestern China... In anurans,advertisement calls(ACs)are an essential form of intraspecific communication.This study evaluates geographical variation in the ACs of Leptobrachella ventripunctata in the Guizhou Plateau,southwestern China,and explores correlations between call characteristics,body size,and environmental factors.ACs are simple calls of L.ventripunctata,and apparent differences were observed in the ACs among different geographical populations of L.ventripunctata.The Call duration(CD)revealed a significant positive correlation with altitude and a significant negative correlation with temperature and humidity.Moreover,the Dominant frequency(DF)exhibited a significant negative correlation with altitude and the habitat closure degree and a significant positive correlation with temperature.These variations in ACs between different geographical populations of L.ventripunctata may critically impact the adaptive evolution of species,and the calls may also be relevant for environmental selection. 展开更多
关键词 ANURAN BIOACOUSTICS environmental factors geographical divergence
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Optimization of magnetic field design for Hall thrusters based on a genetic algorithm
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作者 谭睿 杭观荣 王平阳 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期82-92,共11页
Magnetic field design is essential for the operation of Hall thrusters.This study focuses on utilizing a genetic algorithm to optimize the magnetic field configuration of SPT70.A 2D hybrid PIC-DSMC and channel-wall er... Magnetic field design is essential for the operation of Hall thrusters.This study focuses on utilizing a genetic algorithm to optimize the magnetic field configuration of SPT70.A 2D hybrid PIC-DSMC and channel-wall erosion model are employed to analyze the plume divergence angle and wall erosion rate,while a Farady probe measurement and laser profilometry system are set up to verify the simulation results.The results demonstrate that the genetic algorithm contributes to reducing the divergence angle of the thruster plumes and alleviating the impact of high-energy particles on the discharge channel wall,reducing the erosion by 5.5%and 2.7%,respectively.Further analysis indicates that the change from a divergent magnetic field to a convergent magnetic field,combined with the upstream shift of the ionization region,contributes to the improving the operation of the Hall thruster. 展开更多
关键词 magnetic field design genetic algorithm divergence angle erosion of discharge channel convergent magnetic field
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Research on aiming methods for small sample size shooting tests of two-dimensional trajectory correction fuse
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作者 Chen Liang Qiang Shen +4 位作者 Zilong Deng Hongyun Li Wenyang Pu Lingyun Tian Ziyang Lin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期506-517,共12页
The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction ... The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future. 展开更多
关键词 Two-dimensional trajectory correction fuse Small sample size test Compatibility test KL divergence Fusion bayesian estimation
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Multiple-model GLMB filter based on track-before-detect for tracking multiple maneuvering targets
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作者 CAO Chenghu ZHAO Yongbo 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第5期1109-1121,共13页
A generalized labeled multi-Bernoulli(GLMB)filter with motion mode label based on the track-before-detect(TBD)strategy for maneuvering targets in sea clutter with heavy tail,in which the transitions of the mode of tar... A generalized labeled multi-Bernoulli(GLMB)filter with motion mode label based on the track-before-detect(TBD)strategy for maneuvering targets in sea clutter with heavy tail,in which the transitions of the mode of target motions are modeled by using jump Markovian system(JMS),is presented in this paper.The close-form solution is derived for sequential Monte Carlo implementation of the GLMB filter based on the TBD model.In update,we derive a tractable GLMB density,which preserves the cardinality distribution and first-order moment of the labeled multi-target distribution of interest as well as minimizes the Kullback-Leibler divergence(KLD),to enable the next recursive cycle.The relevant simulation results prove that the proposed multiple-model GLMB-TBD(MM-GLMB-TBD)algorithm based on K-distributed clutter model can improve the detecting and tracking performance in both estimation error and robustness compared with state-of-the-art algorithms for sea clutter background.Additionally,the simulations show that the proposed MM-GLMB-TBD algorithm can accurately output the multitarget trajectories with considerably less computational complexity compared with the adapted dynamic programming based TBD(DP-TBD)algorithm.Meanwhile,the simulation results also indicate that the proposed MM-GLMB-TBD filter slightly outperforms the JMS particle filter based TBD(JMSMeMBer-TBD)filter in estimation error with the basically same computational cost.Finally,the impact of the mismatches on the clutter model and clutter parameter is investigated for the performance of the MM-GLMB-TBD filter. 展开更多
关键词 generalized labeled multi-Bernoulli(GLMB) trackbefore-detect(TBD) jump Markovian system(JMS) K-DISTRIBUTION Kullback-Leibler divergence(KLD)
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Kullback-Leibler Divergence Based ISAC Constellation and Beamforming Design in the Presence of Clutter
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作者 TANG Shuntian WANG Xinyi +1 位作者 XIA Fanghao FEI Zesong 《ZTE Communications》 2024年第3期4-12,共9页
Integrated sensing and communication(ISAC)is regarded as a pivotal technology for 6G communication.In this paper,we employ Kullback-Leibler divergence(KLD)as the unified performance metric for ISAC systems and investi... Integrated sensing and communication(ISAC)is regarded as a pivotal technology for 6G communication.In this paper,we employ Kullback-Leibler divergence(KLD)as the unified performance metric for ISAC systems and investigate constellation and beamforming design in the presence of clutters.In particular,the constellation design problem is solved via the successive convex approximation(SCA)technique,and the optimal beamforming in terms of sensing KLD is proven to be equivalent to maximizing the signal-to-interference-plus-noise ratio(SINR)of echo signals.Numerical results demonstrate the tradeoff between sensing and communication performance under different parameter setups.Additionally,the beampattern generated by the proposed algorithm achieves significant clutter suppression and higher SINR of echo signals compared with the conventional scheme. 展开更多
关键词 constellation design clutter suppression integrated sensing and communications Kullback-Leibler divergence
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Phenotypic divergences induced by different residence time in invasive common ragweeds 被引量:1
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作者 Annamaria Fenesi Zoltan Botta-Dukat 《Journal of Plant Ecology》 SCIE 2012年第2期174-181,共8页
Aims Possible shifts in the phenotypic performance along invasive plants’spreading route are rarely examined due to the discontinuous and incomplete records of exotic species.As the invasion history of common ragweed... Aims Possible shifts in the phenotypic performance along invasive plants’spreading route are rarely examined due to the discontinuous and incomplete records of exotic species.As the invasion history of common ragweed(Ambrosia artemisiifolia L.)is well documented in Hungary,its residence time is known for each location.By sampling a sequence of older to more recently established populations,we aimed to determine(i)whether there are phenotypic divergences along the historical spreading route of A.artemisiifolia;(ii)which traits are under selection during the invasion process and(iii)the extent of maternal effects on the individual’s performance.Methods We used a hierarchical sampling design to collect seeds from 64 individuals belonging to eight sites in four residence time categories(seven populations along the historical spreading route of ragweed in Hungary and one recently invaded site in Romania).We selected four large and four small individual plants in each population to control for maternal effects.The offspring were reared in a common garden located in Romania.Five vegetative phenotypic traits were measured at the end of the experiments and used in the subsequent analysis(plant height,basal diameter,number of secondary axes,length of the longest secondary axis and biomass).To summarize the variation of these highly correlated traits,principal component analysis was performed first and then the important components were used in linear mixed effect models.Important Findings The residence time categories were significantly distinguished by the first component,which compresses the variation of all five measured traits.The measures gradually decrease from populations with the longest residence time(introduced more than 65 years ago)towards the most recently established populations(established less than 30 years ago).These differences might reflect the invasion history of the populations:the longer the residence time the higher the chance to develop relevant traits beneficial in invasion process.The size of the mother plant significantly influenced not only the seed mass(inversely)but also the adult performance of its offspring(directly). 展开更多
关键词 Ambrosia artemisiifolia maternal effect phenotypic divergence plant invasion residence time
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Gapless genome assembly of azalea and multi-omics investigation into divergence between two species with distinct f lower color 被引量:4
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作者 Shuai Nie Shi-Wei Zhao +15 位作者 Tian-Le Shi Wei Zhao Ren-Gang Zhang Xue-Chan Tian Jing-Fang Guo Xue-Mei Yan Yu-Tao Bao Zhi-Chao Li Lei Kong Hai-Yao Ma Zhao-Yang Chen Hui Liu Yousry AEl-Kassaby Ilga Porth Fu-Sheng Yang Jian-Feng Mao 《Horticulture Research》 SCIE CSCD 2023年第1期193-206,共14页
The genus Rhododendron(Ericaceae),with more than 1000 species highly diverse in f lower color,is providing distinct ornamental values and a model system for f lower color studies.Here,we investigated the divergence be... The genus Rhododendron(Ericaceae),with more than 1000 species highly diverse in f lower color,is providing distinct ornamental values and a model system for f lower color studies.Here,we investigated the divergence between two parental species with different f lower color widely used for azalea breeding.Gapless genome assembly was generated for the yellow-f lowered azalea,Rhododendron molle.Comparative genomics found recent proliferation of long terminal repeat retrotransposons(LTR-RTs),especially Gypsy,has resulted in a 125 Mb(19%)genome size increase in species-specific regions,and a significant amount of dispersed gene duplicates(13402)and pseudogenes(17437).Metabolomic assessment revealed that yellow f lower coloration is attributed to the dynamic changes of carotenoids/f lavonols biosynthesis and chlorophyll degradation.Time-ordered gene co-expression networks(TO-GCNs)and the comparison confirmed the metabolome and uncovered the specific gene regulatory changes underpinning the distinct f lower pigmentation.B3 and ERF TFs were found dominating the gene regulation of carotenoids/f lavonols characterized pigmentation in R.molle,while WRKY,ERF,WD40,C2H2,and NAC TFs collectively regulated the anthocyanins characterized pigmentation in the red-f lowered R simsii.This study employed a multi-omics strategy in disentangling the complex divergence between two important azaleas and provided references for further functional genetics and molecular breeding. 展开更多
关键词 DIVERGENCE YELLOW COLLECTIVE
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Selective footprints and genes relevant to cold adaptation and other phenotypic traits are unscrambled in the genomes of divergently selected chicken breeds 被引量:2
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作者 Michael N.Romanov Alexandra S.Abdelmanova +11 位作者 Vladimir I.Fisinin Elena A.Gladyr Natalia A.Volkova Olga A.Koshkina Andrey N.Rodionov Anastasia N.Vetokh Igor V.Gusev Dmitry V.Anshakov Olga I.Stanishevskaya Arsen V.Dotsev Darren K.Griffin Natalia A.Zinovieva 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第3期887-907,共21页
Background The genomes of worldwide poultry breeds divergently selected for performance and other phenotypic traits may also be affected by,and formed due to,past and current admixture events.Adaptation to diverse env... Background The genomes of worldwide poultry breeds divergently selected for performance and other phenotypic traits may also be affected by,and formed due to,past and current admixture events.Adaptation to diverse environments,including acclimation to harsh climatic conditions,has also left selection footprints in breed genomes.Results Using the Chicken 50K_CobbCons SNP chip,we genotyped four divergently selected breeds:two aboriginal,cold tolerant Ushanka and Orloff Mille Fleur,one egg-type Russian White subjected to artificial selection for cold tolerance,and one meat-type White Cornish.Signals of selective sweeps were determined in the studied breeds using three methods:(1)assessment of runs of homozygosity islands,(2)F_(ST) based population differential analysis,and(3)haplotype differentiation analysis.Genomic regions of true selection signatures were identified by two or more methods or in two or more breeds.In these regions,we detected 540 prioritized candidate genes supplemented them with those that occurred in one breed using one statistic and were suggested in other studies.Amongst them,SOX5,ME3,ZNF536,WWP1,RIPK2,OSGIN2,DECR1,TPO,PPARGC1A,BDNF,MSTN,and beta-keratin genes can be especially mentioned as candidates for cold adaptation.Epigenetic factors may be involved in regulating some of these important genes(e.g.,TPO and BDNF).Conclusion Based on a genome-wide scan,our findings can help dissect the genetic architecture underlying various phenotypic traits in chicken breeds.These include genes representing the sine qua non for adaptation to harsh environments.Cold tolerance in acclimated chicken breeds may be developed following one of few specific gene expression mechanisms or more than one overlapping response known in cold-exposed individuals,and this warrants further investigation. 展开更多
关键词 ACCLIMATION Adaptation Chicken breeds Cold tolerance Divergent selection Genetic diversity Genomewide scan Phenotypic traits Selective sweeps
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Insights into cryptic speciation of quillworts in China 被引量:1
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作者 Yu-Feng Gu Jiang-Ping Shu +7 位作者 Yi-Jun Lu Hui Shen Wen Shao Yan Zhou Qi-Meng Sun Jian-Bing Chen Bao-Dong Liu Yue-Hong Yan 《Plant Diversity》 SCIE CAS CSCD 2023年第3期284-301,共18页
Cryptic species are commonly misidentified because of high morphological similarities to other species.One group of plants that may harbor large numbers of cryptic species is the quillworts(Isoetes spp.),an ancient aq... Cryptic species are commonly misidentified because of high morphological similarities to other species.One group of plants that may harbor large numbers of cryptic species is the quillworts(Isoetes spp.),an ancient aquatic plant lineage.Although over 350 species of Isoetes have been reported globally,only ten species have been recorded in China.The aim of this study is to better understand Isoetes species diversity in China.For this purpose,we systematically explored the phylogeny and evolution of Isoetes using complete chloroplast genome(plastome)data,spore morphology,chromosome number,genetic structure,and haplotypes of almost all Chinese Isoetes populations.We identified three ploidy levels of Isoetes in Chinaddiploid(2n=22),tetraploid(2n=44),and hexaploid(2n=66).We also found four megaspore and microspore ornamentation types in diploids,six in tetraploids,and three in hexaploids.Phylogenetic analyses confirmed that I.hypsophila as the ancestral group of the genus and revealed that Isoetes diploids,tetraploids,and hexaploids do not form monophyletic clades.Most individual species possess a single genetic structure;however,several samples have conflicting positions on the phylogenetic tree based on SNPs and the tree based on plastome data.All 36 samples shared 22 haplotypes.Divergence time analysis showed that I.hypsophila diverged in the early Eocene(~48.05 Ma),and most other Isoetes species diverged 3-20 Ma.Additionally,different species of Isoetes were found to inhabit different water systems and environments along the Yangtze River.These findings provide new insights into the relationships among Isoetes species in China,where highly similar morphologic populations may harbor many cryptic species. 展开更多
关键词 Plastid genome ISOETACEAE PHYLOGENY EVOLUTIONARY Divergence time
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Phylogenetic diversity of eastern Asia-eastern North America disjunct plants is mainly associated with divergence time 被引量:1
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作者 Han-Yang Lin Miao Sun +6 位作者 Ya-Jun Hao Daijiang Li Matthew A.Gitzendanner Cheng-Xin Fu Douglas E.Soltis Pamela S.Soltis Yun-Peng Zhao 《Plant Diversity》 SCIE CAS CSCD 2023年第1期27-35,共9页
The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution.However,the patterns of phylogenetic diversity(PD) and phylogenetic beta diversity... The underlying causes of biodiversity disparities among geographic regions have long been a fundamental theme in ecology and evolution.However,the patterns of phylogenetic diversity(PD) and phylogenetic beta diversity(PBD) of congeners that are disjunctly distributed between eastern Asia-eastern North America(EA-ENA disjuncts) and their associated factors remain unknown.Here we investigated the standardized effect size of PD(SES-PD),PBD,and potentially associated factors in 11natural mixed forest sites(five in EA and six in ENA) where abundant EA-ENA disjuncts occur.We found that the disjuncts in ENA possessed higher SES-PD than those in EA at the continental scale(1.96vs-1.12),even though the number of disjunct species in ENA is much lower than in EA(128 vs 263).SESPD of the EA-ENA disjuncts tended to decrease with increasing latitude in 11 sites.The latitudinal diversity gradient of SES-PD was stronger in EA sites than in ENA sites.Based on the unweighted unique fraction metric(UniFrac) distance and the phylogenetic community dissimilarity,PBD showed that the two northern sites in EA were more similar to the six-site ENA group than to the remaining southern EA sites.Based on the standardized effect size of mean pairwise distances(SES-MPD),nine of eleven studied sites showed a neutral community structure(-1.96 ≤SES-MPD ≤1.96).Both Pearson’s r and structural equation modeling suggested that SES-PD of the EA-ENA disjuncts was mostly associated with mean divergence time.Moreover,SES-PD of the EA-ENA disjuncts was positively correlated with temperaturerelated climatic factors,although negatively correlated with mean diversification rate and community structure.By applying approaches from phylogenetics and community ecology,our work sheds light on historical patterns of the EA-ENA disjunction and paves the way for further research. 展开更多
关键词 EA-ENA disjuncts Climatic factors Community assembly processes Diversification rate Divergence time Phylogenetic diversity
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Ensemble Bayesian method for parameter distribution inference:application to reactor physics 被引量:1
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作者 Jia‑Qin Zeng Hai‑Xiang Zhang +1 位作者 He‑Lin Gong Ying‑Ting Luo 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第12期216-228,共13页
The estimation of model parameters is an important subject in engineering.In this area of work,the prevailing approach is to estimate or calculate these as deterministic parameters.In this study,we consider the model ... The estimation of model parameters is an important subject in engineering.In this area of work,the prevailing approach is to estimate or calculate these as deterministic parameters.In this study,we consider the model parameters from the perspective of random variables and describe the general form of the parameter distribution inference problem.Under this framework,we propose an ensemble Bayesian method by introducing Bayesian inference and the Markov chain Monte Carlo(MCMC)method.Experiments on a finite cylindrical reactor and a 2D IAEA benchmark problem show that the proposed method converges quickly and can estimate parameters effectively,even for several correlated parameters simultaneously.Our experiments include cases of engineering software calls,demonstrating that the method can be applied to engineering,such as nuclear reactor engineering. 展开更多
关键词 Model parameters Bayesian inference Frequency distribution Ensemble Bayesian method KL divergence
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Molecular phylogeny and identification of agromyzid leafminers in China,with a focus on the worldwide genus Liriomyza(Diptera:Agromyzidae)
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作者 LIANG Yong-xuan DU Su-jie +5 位作者 ZHONG Yu-jun WANG Qi-jing ZHOU Qiong WAN Fang-hao GUO Jian-yang LIU Wan-xue 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第10期3115-3134,共20页
Leaf-mining flies(Diptera:Agromyzidae)are a diverse family of small-bodied insects that feed on living plant tissues as larvae.Various species in this family are considered globally invasive and have caused great agri... Leaf-mining flies(Diptera:Agromyzidae)are a diverse family of small-bodied insects that feed on living plant tissues as larvae.Various species in this family are considered globally invasive and have caused great agricultural economic losses.In China,economically important vegetable crops have been seriously damaged by these pest insects,especially by species of the genus Liriomyza.However,these species are difficult to differentiate because of their morphological similarities,and the Chinese fauna remains poorly known.To explore the relevant pest species in China and their phylogeny,agromyzid leafminers were collected from 2016 to 2019,and identified based on morphological characteristics and DNA barcodes.In total,27 species from five genera of Agromyzidae were sampled and identified,including 16species of Liriomyza.Both mitochondrial and nuclear genes were used to reconstruct their phylogenetic relationships and estimate the divergence time.Highly congruent and well-supported phylogenetic trees were obtained using the Bayesian inference and maximum-likelihood methods.This analysis revealed two main clades in Liriomyza,and clade 2was inferred to have diverged from clade 1 approximately 27.40 million years ago(95%highest posterior density:23.03–31.52 million years ago)in the Oligocene.Differences were observed in the distribution patterns and host associations between the Liriomyza clades.Clade 2 species are distributed in cool,high-latitude environments,suggesting that they may have evolved into a cool-adapted lineage. 展开更多
关键词 agromyzid leafminer LIRIOMYZA PHYLOGENETICS IDENTIFICATION divergence time distribution pattern
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Phenotypical and gene co-expression network analyses of seed shattering in divergent sorghum(Sorghum spp.)
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作者 Xin Xiao Mengjiao Zhu +6 位作者 Yishan Liu Jingru Zheng Yiping Cui Candong Xiong Jiangjiang Liu Jun Chen Hongwei Cai 《The Crop Journal》 SCIE CSCD 2023年第2期478-489,共12页
Sorghum[Sorghum bicolor(L.)Moench],a multipurpose C4 crop,is also a model species of the Poaceae family for plant research.During the process of domestication,the modification of seed dispersal mode is considered a ke... Sorghum[Sorghum bicolor(L.)Moench],a multipurpose C4 crop,is also a model species of the Poaceae family for plant research.During the process of domestication,the modification of seed dispersal mode is considered a key event,as the loss of seed shattering caused a significant increase in yield.In order to understand the seed shattering process in sorghum,we further studied eight previously identified divergent sorghum germplasm with different shattering degrees.We described their phenotypes in great detail,analyzed the histology of abscission zone,and conducted a gene co-expression analysis.We observed that the abscission layer of the most strong-shattering varieties began to differentiate before the 5-10 cm panicles development stage and was completely formed at flag leaf unfolding.The protective cells on the pedicels were also fully lignified by flowering.Through the weighted gene correlation network analysis(WGCNA),we mined for candidate genes involved in the abscission process at the heading stage.We found that these genes were mainly associated with such biological processes as hormone signal transmission(SORBI_3003G361300,SORBI_3006G216500,SORBI_3009G027800,SORBI_3007G077200),cell wall modification and degradation(SORBI_3002G205500,SORBI_3004G013800,SORBI_3010G022400,SORBI_3003G251800,SORBI_3003G254700,SORBI_3003G410800,SORBI_3009G162700,SORBI_3001G406700,SORBI_3004G042700,SORBI_3004G244600,SORBI_3001G099100),and lignin synthesis(SORBI_3004G220700,SORBI_3004G062500,SORBI_3010G214900,SORBI_3009G181800).Our study has provided candidate genes required for shedding for further study.We believe that function characterization of these genes may provide insight into our understanding of seed shattering process. 展开更多
关键词 Divergent sorghum Seed shattering Abscission zone WGCNA
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