16 results on '"YANG Jian"'
Search Results
2. A juvenile skull from the early Palaeocene of China extends the appearance of crocodyloids in Asia back by 15–20 million years.
- Author
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Boerman, Sophie A, Perrichon, Gwendal, Yang, Jian, Li, Cheng-Sen, Martin, Jeremy E, Speijer, Robert P, and Smith, Thierry
- Subjects
MANDIBLE ,SKULL ,CROCODILIANS ,EOCENE Epoch ,FOSSILS ,PALEOGENE - Abstract
The earliest Crocodylia from Asia have been represented so far only by alligatoroids and planocraniids. Although definitive crocodyloids are not known until the late Eocene, it has been hypothesized that Asiatosuchus -like basal crocodyloids originated in Asia before the late Palaeocene. In this paper, we describe a new fossil crocodyloid from the lower Palaeocene of Qianshan Basin, Anhui Province, China. The skull and lower jaw fragment exhibit several characteristics typical of juvenile crocodylians. They also display a combination of features not seen in any other taxon, warranting the erection of a new species and genus, Qianshanosuchus youngi gen. & sp. nov. Its affinities are tested in phylogenetic analyses based on two recent character matrices of Eusuchia. To assess the effect of juvenile characteristics on the outcome of the phylogenetic analyses, juvenile specimens of extant crocodylian taxa are analysed in the same way, showing that the effect of their ontogenetic stage on their placement in the tree is minimal. Our analyses point to a basal crocodyloid position for Q. youngi. With these findings, the presence of Crocodyloidea in Asia is extended to the early Palaeocene, 15–20 Myr earlier than formerly thought. Furthermore, our results corroborate previous hypotheses of a Palaeocene dispersal route of Asiatosuchus -like crocodyloids from Asia into Europe. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Organic acid metabolites involved in local adaptation to altitudinal gradient in Agriophyllum squarrosum, a desert medicinal plant.
- Author
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Zhou, Shanshan, Yang, Jian, Qian, Chaoju, Yin, Xiaoyue, Yan, Xia, Fan, Xingke, Fang, Tingzhou, Gao, Yuan, Chang, Yuxiao, and Ma, Xiao-Fei
- Subjects
- *
ORGANIC acids , *DESERT plants , *GERMPLASM , *MEDICINAL plants , *CLIMATE change , *SALICYLIC acid , *CITRIC acid - Abstract
Agriophyllum squarrosum (L.) Moq., a pioneer plant endemic to the temperate deserts of Asia, could be domesticated into an ideal crop with outstanding ecological and medicinal characteristics. A previous study showed differential organic acid accumulation between two in situ altitudinal ecotypes. To verify whether this accumulation was determined by environmental or genetic factors, we conducted organic acid targeted metabolic profiling among 14 populations of A. squarrosum collected from regions with different altitudes based on a common garden experiment. Results showed that the most abundant organic acid in A. squarrosum was citric acid (96.03%, 2322.90 μg g–1). Association analysis with in situ environmental variables showed that salicylic acid content was positively correlated with altitudinal gradient. Considering the enrichment of salicylic acid and protocatechualdehyde in high-altitude populations based on the common garden experiment, and the high expression of their biosynthesis relative genes (i.e., PAL and C4H) in the in situ high-altitude ecotype, we propose that organic acid accumulation could be involved in local adaptation to high altitudes. This study not only addresses the molecular basis of local adaptation involving the accumulation of organic acids in the desert plant A. squarrosum but also provides a method to screen wild germplasms to mitigate the impact of global climate change. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
4. Variations in Flavonoid Metabolites Along Altitudinal Gradient in a Desert Medicinal Plant Agriophyllum squarrosum.
- Author
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Zhou, Shanshan, Yan, Xia, Yang, Jian, Qian, Chaoju, Yin, Xiaoyue, Fan, Xingke, Fang, Tingzhou, Gao, Yuan, Chang, Yuxiao, Liu, Weimin, and Ma, Xiao-Fei
- Subjects
DESERT plants ,MEDICINAL plants ,CROPS ,FLAVONOIDS ,ALTITUDES ,ENDEMIC plants ,QUERCETIN - Abstract
Agriophyllum squarrosum (L.) Moq., a pioneer plant endemic to the temperate deserts of Asia, could be domesticated into an ideal crop with outstanding ecological and medicinal characteristics. A previous study showed differential flavonoid accumulation between two in situ altitudinal ecotypes. To verify whether this accumulation was determined by environmental or genetic factors, we conducted flavonoid-targeted metabolic profiling among 14 populations of A. squarrosum collected from regions with different altitudes based on a common garden experiment. Results showed that the most abundant flavonoid in A. squarrosum was isorhamnetin (48.40%, 557.45 μg/g), followed by quercetin (13.04%, 150.15 μg/g), tricin (11.17%, 128.70 μg/g), isoquercitrin (7.59%, 87.42 μg/g), isovitexin (7.20%, 82.94 μg/g), and rutin (7.00%, 80.62 μg/g). However, based on a common garden at middle-altitude environment, almost none of the flavonoids was enriched in the high-altitude populations, and even some flavonoids, such as quercetin, tricin, and rutin, were significantly enriched in low-altitude populations. This phenomenon indicated that the accumulation of flavonoids was not a result of local adaptation to high altitude. Furthermore, association analysis with in situ environmental variables showed that the contents of quercetin, tricin, and rutin were strongly positively correlated with latitude, longitude, and precipitation gradients and negatively correlated with temperature gradients. Thus, we could conclude that the accumulations of flavonoids in A. squarrosum were more likely as a result of local adaption to environmental heterogeneity combined with precipitation and temperature other than high altitude. This study not only provides an example to understand the molecular ecological basis of pharmacognosy, but also supplies methodologies for developing a new industrial crop with ecological and agricultural importance. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
5. Transcriptomic resources for prairie grass (Bromus catharticus): expressed transcripts, tissue-specific genes, and identification and validation of EST-SSR markers.
- Author
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Sun, Ming, Dong, Zhixiao, Yang, Jian, Wu, Wendan, Zhang, Chenglin, Zhang, Jianbo, Zhao, Junming, Xiong, Yi, Jia, Shangang, and Ma, Xiao
- Subjects
GENETIC variation ,BROMEGRASSES ,GENETIC polymorphisms ,PHENOTYPES ,PRAIRIES - Abstract
Background: Prairie grass (Bromus catharticus) is a typical cool-season forage crop with high biomass production and fast growth rate during winter and spring. However, its genetic research and breeding has remained stagnant due to limited available genomic resources. The aim of this study was to generate large-scale genomic data using high-throughput transcriptome sequencing, and perform a preliminary validation of EST-SSR markers of B. catharticus. Results: Eleven tissue samples including seeds, leaves, and stems were collected from a new high-yield strain of prairie grass BCS1103. A total of 257,773 unigenes were obtained, of which 193,082 (74.90%) were annotated. Comparison analysis between tissues identified 1803, 3030, and 1570 genes specifically and highly expressed in seed, leaf, and stem, respectively. A total of 37,288 EST-SSRs were identified from unigene sequences, and more than 80,000 primer pairs were designed. We synthesized 420 primer pairs and selected 52 ones with high polymorphisms to estimate genetic diversity and population structure in 24 B. catharticus accessions worldwide. Despite low diversity indicated by an average genetic distance of 0.364, the accessions from South America and Asia and wild accessions showed higher genetic diversity. Moreover, South American accessions showed a pure ancestry, while Asian accessions demonstrated mixed internal relationships, which indicated a different probability of gene flow. Phylogenetic analysis clustered the studied accessions into four clades, being consistent with phenotypic clustering results. Finally, Mantel analysis suggested the total phenotypic variation was mostly contributed by genetic component. Stem diameter, plant height, leaf width, and biomass yield were significantly correlated with genetic data (r > 0.6, P < 0.001), and might be used in the future selection and breeding. Conclusion: A genomic resource was generated that could benefit genetic and taxonomic studies, as well as molecular breeding for B. catharticus and its relatives in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
6. Biogeographic diversification of Eranthis (Ranunculaceae) reflects the geological history of the three great Asian plateaus.
- Author
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Xiang, Kun-Li, Erst, Andrey S., Yang, Jian, Peng, Huan-Wen, Ortiz, Rosa del C., Jabbour, Florian, Erst, Tatyana V., and Wang, Wei
- Subjects
RANUNCULACEAE ,SEED dispersal ,MIOCENE Epoch ,EOCENE Epoch ,PLATEAUS - Abstract
The evolutionary history of organisms with poor dispersal abilities usually parallels geological events. Collisions of the Indian and Arabian plates with Eurasia greatly changed Asian topography and affected regional and global climates as well as biotic evolution. However, the geological evolution of Asia related to these two collisions remains debated. Here, we used Eranthis, an angiosperm genus with poor seed dispersal ability and a discontinuous distribution across Eurasia, to shed light on the orogenesis of the Qinghai–Tibetan, Iranian and Mongolian Plateaus. Our phylogenetic analyses show that Eranthis comprises four major geographical clades: east Qinghai–Tibetan Plateau clade (I-1), North Asian clade (I-2), west Qinghai–Tibetan Plateau clade (II-1) and Mediterranean clade (II-2). Our molecular dating and biogeographic analyses indicate that within Eranthis, four vicariance events correlate well with the two early uplifts of the Qinghai–Tibetan Plateau during the Late Eocene and the Oligocene–Miocene boundary and the two uplifts of the Iranian Plateau during the Middle and Late Miocene. The origin and divergence of the Mongolian Plateau taxa are related to the two uplifts of the Mongolian Plateau during the Middle and Late Miocene. Additionally, our results are in agreement with the hypothesis that the central part of Tibet only reached an altitude of less than 2.3 km at approximately 40 Ma. This study highlights that organismal evolution could be related to the formation of the three great Asian plateaus, hence contributing to the knowledge on the timing of the key tectonic events in Asia. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
7. The Eocene climate of China, the early elevation of the Tibetan Plateau and the onset of the Asian Monsoon.
- Author
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Wang, Qing, Spicer, Robert A., Yang, Jian, Wang, Yu‐Fei, and Li, Cheng‐Sen
- Subjects
EOCENE palynology ,EOCENE paleoclimatology ,PALEOCLIMATOLOGY ,METEOROLOGICAL precipitation ,MONSOONS - Abstract
Eocene palynological samples from 37 widely distributed sites across China were analysed using co-existence approach to determine trends in space and time for seven palaeoclimate variables: Mean annual temperature, mean annual precipitation, mean temperature of the warmest month, mean temperature of the coldest month, mean annual range of temperature, mean maximum monthly precipitation and mean minimum monthly precipitation. Present day distributions and observed climates within China of the nearest living relatives of the fossil forms were used to find the range of a given variable in which a maximum number of taxa can coexist. Isotherm and isohyet maps for the early, middle and late Eocene were constructed. These illustrate regional changing patterns in thermal and precipitational gradients that may be interpreted as the beginnings of the modern Asian Monsoon system, and suggest that the uplift of parts of the Tibetan Plateau appear to have taken place by the middle to late Eocene. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
8. Stock market integration and financial crises: the case of Asia.
- Author
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Yang, Jian, Kolari, James W., and Min, Insik
- Subjects
STOCK exchanges ,FINANCIAL crises ,COMPARATIVE studies - Abstract
This study examines long-run relationships and short-run dynamic causal linkages among the US, Japanese, and ten Asian emerging stock markets, with the particular attention to the 1997-1998 Asian financial crisis. Extending related empirical studies, comparative analyses of pre-crisis, crisis, and post-crisis periods are conducted to comprehensively evaluate how stock market integration is a1ected by financial crises. In general, the results for the case of Asia show that both long-run cointegration relationships and short-run causal linkages among these markets were strengthened during the crisis and that these markets have generally been more integrated after the crisis than before the crisis. Detailed country-by-country analyses are provided, which yield a variety of new results concerning the roles of individual countries in international stock market integration. An important implication of our findings is that the degree of integration among countries tends to change over time, especially around periods marked by financial crises. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
9. Experimental and numerical investigations on load-carrying capacity of dowel-type bolted bamboo joints.
- Author
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Wang, Feiliang and Yang, Jian
- Subjects
- *
BOLTED joints , *BAMBOO , *STRUCTURAL failures , *INVESTIGATIONS , *FAILURE mode & effects analysis - Abstract
• Experimental studies of the slotted-in dowelled bamboo-to-steel joint with/without infilling grout. • Failure behaviours and load-displacement curves for various specimens were predicted by FEM. • Analytical design models were proposed based on the results from test and FEM for the joints. Bamboo has been widely used for structural and non-structural purpose, for example as scaffolding and cladding for many centuries in South East Asian countries such as China and India, due to its high strength-to-weight ratio, low price and recyclability. In today's trend of sustainable development, there is a renewed interest in the use of bamboo for modern prefabricated structures. In this paper, dowel-type bamboo joints are introduced for prefabricated bamboo structures. An experimental study has been undertaken to investigate the structural behaviour and the failure mechanisms of the dowelled joints with varying configurations. Test results reveal that the ductile failure mode of the bamboo occurred when large end spacing was applied, and the infilling grout can significantly increase the load-carrying capacity of the dowelled joint. Three-dimensional finite element models were established and validated using available experimental data. Extensive parametric studies were carried out based on the simulation approach to investigate the effects of key influencing variables involved, i.e. hole clearance, friction coefficient, bolt strength, bamboo thickness, grout strength and end spacing. Moreover, analytical models for designing the dowelled joints are proposed and compared with the current codified approach. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
10. Early Miocene elevation in northern Tibet estimated by palaeobotanical evidence.
- Author
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Sun, Bin, Wang, Yu-Fei, Li, Cheng-Sen, Yang, Jian, Li, Jin-Feng, Li, Ye-Liang, Deng, Tao, Wang, Shi-Qi, Zhao, Min, Spicer, Robert A., Ferguson, David K., and Mehrotra, Rakesh C.
- Subjects
MIOCENE Epoch ,MONSOONS ,PALEOCLIMATOLOGY ,MIOCENE paleobotany - Abstract
The area and elevation of the Tibetan Plateau over time has directly affected Asia's topography, the characteristics of the Asian monsoon, and modified global climate, but in ways that are poorly understood. Charting the uplift history is crucial for understanding the mechanisms that link elevation and climate irrespective of time and place. While some palaeoelevation data are available for southern and central Tibet, clues to the uplift history of northern Tibet remain sparse and largely circumstantial. Leaf fossils are extremely rare in Tibet but here we report a newly discovered early Miocene barberry (Berberis) from Wudaoliang in the Hoh-Xil Basin in northern Tibet, at a present altitude of 4611 ± 9 m. Considering the fossil and its nearest living species probably occupied a similar or identical environmental niche, the palaeoelevation of the fossil locality, corrected for Miocene global temperature difference, is estimated to have been between 1395 and 2931 m, which means this basin has been uplifted ~2-3 km in the last 17 million years. Our findings contradict hypotheses that suggest northern Tibet had reached or exceeded its present elevation prior to the Miocene. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
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11. Medicinal plants of the genus Gelsemium (Gelsemiaceae, Gentianales)—A review of their phytochemistry, pharmacology, toxicology and traditional use.
- Author
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Jin, Gui-Lin, Su, Yan-Ping, Liu, Ming, Xu, Ying, Yang, Jian, Liao, Kai-Jun, and Yu, Chang-Xi
- Subjects
- *
MIGRAINE , *HEADACHE treatment , *NEURALGIA , *SCIATICA treatment , *TUMOR treatment , *MEDICINAL plants , *ALKALOIDS , *ALTERNATIVE medicine , *ANALGESICS , *ANTI-inflammatory agents , *ANTINEOPLASTIC agents , *PHYSICAL & theoretical chemistry , *DRUG toxicity , *IMMUNE system , *MEDLINE , *ONLINE information services , *HEALTH outcome assessment , *TERPENES , *TRANQUILIZING drugs , *SYSTEMATIC reviews , *EVIDENCE-based medicine , *PHYTOCHEMICALS , *PLANT extracts , *PROFESSIONAL practice , *TREATMENT effectiveness , *DESCRIPTIVE statistics , *THERAPEUTICS ,THERAPEUTIC use of plant extracts - Abstract
Abstract: Ethnopharmacological relevance: In the genus Gelsemium, Gelsemium elegans (Gardn. & Champ.) Benth. has been recognized as a toxic plant that is widely distributed in Southeast Asia and has been used as traditional Chinese medicine for the treatment of rheumatoid pain, neuropathic pain, spasticity, skin ulcers and cancers for many years. Gelsemium sempervirens (L.) J.St.-Hil. has been used since the nineteenth century in homeopathy for treating anxiety, neuralgia, migraine and spasmodic disorders, such as asthma and whooping cough in North America. This review aims to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of medicinal plants in the genus Gelsemium. The overall objective is to explore the evidence supporting its ethnopharmacological effectiveness. Materials and methods: A literature survey was performed by searching the scientific databases Pubmed, Google Scholar, SciFinder, Scopus, Web of Science and the Chinese CNKI, in addition to traditional Chinese medicine and homeopathic texts for information on Gelsemium. Results: Plants of the genus Gelsemium have been used in traditional medicine for the treatment of migraines, neuralgia, sciatica, cancer and various types of sores. Studies into the phytochemical composition of this genus have shown that all of the species are rich sources of monoterpene indole alkaloids and that they have attracted the attention of many researchers due to their markedly diverse and complex architecture. To date, a total of 121 alkaloids have been isolated and identified from the genus. The crude extracts, as well as the monomeric compounds, from the genus possess anti-tumor, analgesic, anxiolytic, anti-inflammatory and immunomodulating pharmacological activities. Conclusion: It is evident from the available literature that Gelsemium species possess potential for use as a beneficial therapeutic remedy. However, the analysis of previous pharmacological research suggests that a clear assignment of active molecules and mechanisms of action is remain lacking. Due to their high toxicity, the studies available on toxicity and safety are inadequate for providing information on clinical utilization. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
12. The Phytogeography of the extinct angiosperm Nordenskioeldia (Trochodendraceae) and its response to climate changes
- Author
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Wang, Yan-Hui, Ferguson, David K., Feng, Guang-Ping, Wang, Yu-Fei, Zhilin, Sergey G., Li, Cheng-Sen, Svetlana, Popova-Tselenkova, Yang, Jian, and Ablaev, Albert G.
- Subjects
- *
CLIMATIC factors of phytogeography , *EXTINCT plants , *FOSSIL angiosperms , *TROCHODENDRACEAE , *CLIMATE change , *DISJUNCT plants , *PLANT morphology , *CENOZOIC paleobotany - Abstract
Abstract: Elucidating the spatio-temporal distributions of terrestrial plants is a key for interpreting the origin of distribution patterns and the tempo of intercontinental disjunction. Nordenskioeldia was distributed in eastern Asia and North America from the Late Cretaceous to the Miocene. Its fossil record provides important information on former patterns of disjunction and dispersal in the Northern Hemisphere. New specimens from the Paleocene of China allow us to further extend the history of the group and provide the impetus to review its distribution in space and time. The comparative morphological survey on fossil Nordenskioeldia found in the Paleocene sediments in both eastern Asia and North America confirms that they belonged to the same morpho-species, which indicates a close floristic continuity between both continents due to land connection available during that time. The spatio-temporal distributions of Nordenskioeldia indicate that the taxon probably expanded eastward from eastern Asia into North America by the end of Early/Middle Maastrichtian, subsequently colonized Greenland, northeastern North America and Spitsbergen in the Early Paleocene, and finally became extinct in the Miocene. The fluctuations in its northern limits took place in response to climate changes: warming from the Paleocene to the Eocene, cooling during the Eocene–Oligocene and amelioration during the Late Oligocene–Mid-Miocene. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
13. A multi-gene phylogeny of the Asian kukri snakes (Oligodon Fitzinger, 1826): Sharpening the blade of the second largest serpent radiation (Reptilia: Squamata: Colubridae).
- Author
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Lee JL, Yushchenko PV, Suwannapoom C, Pawangkhanant P, Grismer LL, Nguyen TV, Deepak V, Narayanan S, Das S, Neang T, Lalremsanga HT, Yang JH, Jablonski D, Erkaya M, Vogel G, Bauer AM, and Poyarkov NA
- Subjects
- Animals, Likelihood Functions, Asia, DNA, Mitochondrial genetics, Cell Nucleus genetics, Phylogeography, Sequence Analysis, DNA, Phylogeny, Colubridae genetics, Colubridae classification, Colubridae anatomy & histology, Bayes Theorem
- Abstract
With 90 recognized species, kukri snakes in the genus Oligodon Fitzinger constitute the second largest snake radiation in the world. Oligodon species are collectively distributed across the Asian continent and possess several ecological and morphological attributes that are unique amongst other snakes. Despite their high levels of species richness, evolutionary relationships within Oligodon are poorly understood due to a limited number of samples and genetic markers available in earlier phylogenies. In this study, we assembled the largest molecular dataset of Oligodon to date, which we use to assess the systematics and biogeography of the entire genus. Based on a combination of maximum likelihood and Bayesian phylogenies using fragments of three mitochondrial genes (12 s, 16 s, CytB) and three nuclear genes (Rag1, C-mos, BDNF), we identify eight deeply divergent clades within Oligodon, of which only two correspond with species groupings that were recognized by previous morphological classifications. Four species delimitation methods employed on the mitochondrial portion of the dataset resulted in dramatically divergent estimations of molecular operational taxonomic units (mOTUs). When combined, all four methods support the existence of unrecognized species-level lineages, but also indicate that several other Oligodon species are poorly differentiated genetically and require additional integrative taxonomic research to properly resolve. Based on divergence dating, we demonstrate that Oligodon began to diversify during the early Neogene and hypothesize that the most recent common ancestor of the genus originated in mainland Southeast Asia. We conclude by recognizing eight phylogenetically defined species groups and identify sampling gaps that require further investigation once new data becomes available. This study contributes to a greater understanding of snake evolution on the Asian continent and acts as a baseline for future studies of this speciose genus., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
14. Geographical verification of Pleuropterus multiflorus thunb. by functional compounds, stable isotope ratios, and multielement combined with machine learning methods.
- Author
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Xiong F, Wang S, Kang C, Wang Y, Bai R, Li H, Yang J, and Guo L
- Subjects
- China, Asia, Isotopes
- Abstract
The dry roots of Pleuropterus multiflorus Thunb. (PM) have been traditionally utilized as functional foods and medicines China and various Asian countries. They are extensively cultivated in multiple provinces in China, with variations in prices and qualities. This study aims to investigate the regional characteristics of PM by 4 stable isotope ratios, 40 multielement and 16 functional compounds contents, using a total of 357 samples from 8 different geographical origins. Machine learning methods were developed to authenticating the geographical origins of PM, yielding the accuracy range from 94.44 % to 100 % in the test set. Notably, the protected designation of origin, Deqing PM, exhibited a high accuracy of 100 % in most models, A total of 30 significant prediction variables, encompassing 16 functional compounds, δ
2 H, 12 rare earth elements, and Cu, were identified. Additionally, the study identified altitude, high temperature, and dry or moisture index as the primary influenced environmental factors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
15. Biogeographic diversification of Eranthis (Ranunculaceae) reflects the geological history of the three great Asian plateaus.
- Author
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Xiang KL, Erst AS, Yang J, Peng HW, Ortiz RDC, Jabbour F, Erst TV, and Wang W
- Subjects
- Asia, Iran, Phylogeny, Phylogeography, Tibet, Ranunculaceae
- Abstract
The evolutionary history of organisms with poor dispersal abilities usually parallels geological events. Collisions of the Indian and Arabian plates with Eurasia greatly changed Asian topography and affected regional and global climates as well as biotic evolution. However, the geological evolution of Asia related to these two collisions remains debated. Here, we used Eranthis , an angiosperm genus with poor seed dispersal ability and a discontinuous distribution across Eurasia, to shed light on the orogenesis of the Qinghai-Tibetan, Iranian and Mongolian Plateaus. Our phylogenetic analyses show that Eranthis comprises four major geographical clades: east Qinghai-Tibetan Plateau clade (I-1), North Asian clade (I-2), west Qinghai-Tibetan Plateau clade (II-1) and Mediterranean clade (II-2). Our molecular dating and biogeographic analyses indicate that within Eranthis , four vicariance events correlate well with the two early uplifts of the Qinghai-Tibetan Plateau during the Late Eocene and the Oligocene-Miocene boundary and the two uplifts of the Iranian Plateau during the Middle and Late Miocene. The origin and divergence of the Mongolian Plateau taxa are related to the two uplifts of the Mongolian Plateau during the Middle and Late Miocene. Additionally, our results are in agreement with the hypothesis that the central part of Tibet only reached an altitude of less than 2.3 km at approximately 40 Ma. This study highlights that organismal evolution could be related to the formation of the three great Asian plateaus, hence contributing to the knowledge on the timing of the key tectonic events in Asia.
- Published
- 2021
- Full Text
- View/download PDF
16. Theoretical and empirical quantification of the accuracy of polygenic scores in ancestry divergent populations.
- Author
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Wang Y, Guo J, Ni G, Yang J, Visscher PM, and Yengo L
- Subjects
- Adult, Africa epidemiology, Aged, Alleles, Asia epidemiology, Asthma diagnosis, Asthma epidemiology, Asthma ethnology, Body Mass Index, Cholesterol blood, Computer Simulation, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 ethnology, Europe epidemiology, Female, Gene Frequency, Genome-Wide Association Study, Humans, Hypertension diagnosis, Hypertension epidemiology, Hypertension ethnology, Linkage Disequilibrium, Male, Middle Aged, Prognosis, Quantitative Trait, Heritable, Risk, Asthma genetics, Diabetes Mellitus, Type 2 genetics, Hypertension genetics, Models, Genetic, Multifactorial Inheritance, Polymorphism, Single Nucleotide
- Abstract
Polygenic scores (PGS) have been widely used to predict disease risk using variants identified from genome-wide association studies (GWAS). To date, most GWAS have been conducted in populations of European ancestry, which limits the use of GWAS-derived PGS in non-European ancestry populations. Here, we derive a theoretical model of the relative accuracy (RA) of PGS across ancestries. We show through extensive simulations that the RA of PGS based on genome-wide significant SNPs can be predicted accurately from modelling linkage disequilibrium (LD), minor allele frequencies (MAF), cross-population correlations of causal SNP effects and heritability. We find that LD and MAF differences between ancestries can explain between 70 and 80% of the loss of RA of European-based PGS in African ancestry for traits like body mass index and type 2 diabetes. Our results suggest that causal variants underlying common genetic variation identified in European ancestry GWAS are mostly shared across continents.
- Published
- 2020
- Full Text
- View/download PDF
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