171 research outputs found

    Population genetic structure of Sedum polytrichoides (Crassulaceae): Insights into barriers to gene flow

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    10 p., tablas, gráf.An area comprising Juwangsan National Park and its adjacent mountains (southeastern Korean Pen- insula) is a good model system for testing the effects of physical barriers to gene flows in plant populations. We predicted that plant species consisting of isolated populations are genetically more differentiated than those that are rather continuously distributed. Most populations of Sedum polytrichoides occur in four isolated valleys, and we assessed the genetic variability and structures using twelve allozyme loci in ten populations. We also com- pared the present results to earlier findings pertaining to the two co-occurring herbs Hylotelephium ussuriense (≡ Sedum ussuriense) (growing only in the four isolated valleys) and S. kamtschaticum (rather continuously dis- tributed). We found moderate levels of within-population genetic variation in S. polytrichoides (H = 0.112). Estimates of among-population divergence in S. polytrichoides were also moderate (F = 0.250) and, as expected, very similar to that of H. ussuriense (0.261) but considerably higher than the variation in S. kamtschat- icum (0.165). An analysis of molecular variance (AMOVA) revealed that S. polytrichoides and H. ussuriense had higher percentages of among-valley variation (19% each) than S. kamtschaticum (4%). Most of this vari- ation, as also indicated by the STRUCTURE program, was due to differences in genetic profiles between the two central valleys. We concluded that the genetic differences observed between species (S. kamtschaticum vs. S. polytrichoides and H. ussuriense) are mainly due to differences in their distribution within the study area.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2063524 and NRF-2013R1A1A3010892 to M.G.C. and M.Y.C., respectivelyPeer reviewe

    Notes on genetic variation in Sedum sarmentosum (Crassulaceae): Implications for the origin of southern Korean populations

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    7 p., 1 mapa, tablasThe succulent herbaceous perennial Sedum sarmentosum commonly grows in the southern part of the Korean Peninsula. It is a species native to China, most likely introduced into Korea due to its edible and medicinal uses. If plants were introduced from a single source, we would expect no or low levels of genetic variation in Korean populations. Alternatively, if plants were introduced from multiple sources, we would expect, in contrast, high levels of genetic diversity. To test which is more likely, we surveyed the degree of allozyme variation in ten populations of this species from southern Korea. We found that S. sarmentosum was monomorphic at all fifteen allozyme loci. How- ever, two congeners (S. polytrichoides and S. kamtschaticum) and two related species (Hylotelephium ussuriense and H. verticillatum) maintain moderate to high levels of genetic diversity (H = 0.144, 0.203, 0.201, and 0.204, respec- tively). We suggest that southern Korean populations of S. sarmentosum likely descended from a single introduction of a few plants and then became naturalized exclusively via vegetative spreading (as plants in Korea, but also as occurs in other parts of its native and naturalized range, are sterile).This research was supported by the National Institute of Biological Resources, Republic of Korea to M.G. C. and the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF-2013R1A1A2063524 and NRF-2013R1A1A 3010892 to M.G.C. and M.Y.C., respectively). This research was also supported by the grant no. 201630I024 (“Proyecto Intramural Especial, PIE” from the CSIC, Spain) to J.L.-P.Peer reviewe

    Is the Baekdudaegan “the Southern Appalachians of the East”? A comparison between these mountain systems, focusing on their role as glacial refugia

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    11 p., mapas, tablasBased on genetic studies and palaeoecological surveys, the main Korean mountain range, the so- called “Baekdudaegan” (BDDG), has been recently suggested to be a major glacial refugium at the Last Glacial Maximum (LGM) for the boreal and temperate flora of northeastern Asia. On the basis of its shared role as a glacial refugium, and on a series of striking similarities in floristic richness and orographic features, the BDDG would constitute a sort of “eastern counterpart” of the Southern Appalachians. Given its floristic, biogeo- graphic, and cultural value, the BDDG merits high priority for conservation.This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF- 2013R1A1A2063524 and NRF-2013R1A1A3010892 to M.G.C. and M.Y.C., respectivelyPeer reviewe

    Genetic Evidence of a Progenitor-Derivative Species Pair in East Asian "Lilium"

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    8 p., tablas, mapasBoreal Lilium distichum and temperate L. tsingtauense are morphologically very similar, thus they have been placed in the section Martagon. Recent molecular phylogenetic analyses revealed that L. distichum and L. tsingtauense are indeed the most closely related species within that section. Lilium distichum has a wider geographic range and a broader niche than L. tsingtauense. We hypothesized that L. distichum— L. tsingtauense might be a classical “progenitor—derivative” (P–D) species pair and examined the levels of allozyme diversity in the two species in South Korea. Whereas the allelic composition of L. tsingtauense represented a subset of L. distichum, the former had significantly lower allozyme variability at both the population and the species levels than the latter. Except for the locus Fe (fluorescent esterase), allele frequencies of L. distichum were very similar to those of L. tsingtauense. Accordingly, pairwise genetic identities between populations of L. distichum and L. tsingtauense were very high, with a mean of 0.919. Our allozyme results support the hypothesis that L. tsingtauense is a derivative species of the progenitor L. distichum.This research was supported by the Basic Science Program through the National Research Foundation of Korea (NRF-2013R1A1A3010892) funded by the Ministry of Education, Science and Technology, the Republic of Korea to M.Y.C.Peer reviewe

    Clonal and genetic structure of Iris odaesanensis and Iris rossii (Iridaceae): insights of the Baekdudaegan Mountains as a glacial refugium for boreal and temperate plants

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    The main Korean mountain range that stretches from north to south (the Baekdudaegan) has been suggested to harbor an important glacial refugium for boreal and temperate plant species. Under this scenario, we expect high levels of within-population genetic variation and low or moderate degree of among-population differentiation within these species. To test this hypothesis, we examined clonal diversity and levels of allozyme diversity in the boreal Iris odaesanensis and in its temperate congener Iris rossii. In addition, we compiled data on boreal and temperate species whose distribution in the Korean Peninsula is mostly centered in the Baekdudaegan to determine if there is a common pattern. We found lower clonal diversity in I. odaesanensis compared to I. rossii. Both studied species maintained high levels of genetic variation as well as a moderate genetic differentiation (%P = 52.5 and 47.5, A = 1.70 and 1.58, H e = 0.158 and 0.150, and F ST = 0.196 and 0.189 for I. odaesanensis and I. rossii, respectively), in line with what occurs for the species distributed on the Baekdudaegan (n = 14, %P = 46.7, A = 1.73, H e = 0.161, and F ST = 0.190). This study strongly suggests that the Baekdudaegan may have acted as a refugium for boreal and temperate species, in a similar way to the southern Appalachians in the eastern United States

    Phylogeography of the endangered orchids Cypripedium japonicum and Cypripedium formosanum in East Asia: Deep divergence at infra- and interspecific levels

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    To date, little is known about the past evolutionary trajectories of rare and endangered orchids native to mainland China, Japan, and Korea (the CJK region). In this study, we focus on two endangered orchids, Cypripedium japonicum (present in the three countries) and C. formosanum (endemic to Taiwan), to understand the divergence/speciation models that would have been operating in this group, including genetic diversity, geographic structure, and colonization pathways across the region. Using a combination of five cpDNA regions, we reconstructed phylogenetic trees and investigated the genetic diversity/structure of 20 populations. Ecological niche modeling was used to gain insight into the paleodistribution and dispersal corridors at the Last Glacial Maximum and to survey climatic niche differences. Populations from mainland China + Korea, Japan, and Taiwan formed three distinct monophyletic lineages and were placed into separate genetic clusters, agreeing with geographic barriers and species boundaries. Populations of C. japonicum in mainland China harbored the highest diversity, suggesting the presence of multiple glacial refugia. The Korean populations would have originated from either western/central or eastern China, probably using a dispersal corridor across the East China Sea shelf. The divergence of C. formosanum is proposed under an allopatric speciation model, also highly influenced by a climate niche shift. In the context of previous studies, a deep divergence in cpDNA sequences between Chinese + Korean and Japanese populations of C. japonicum may be taken as an example of the speciation events of the CJK flora since the late Neogene that have led to its current species richness.This study was supported by the Biodiversity Survey, Observation and Assessment Program of the Ministry of Ecology and Environment of China to HZT and by Basic Science Program through the National Research Foundation of Korea (NRF-2017R1A2B4012215) to MGC, and funded by the Ministry of Science and ICT of the Republic of Korea (NRF-2020R1I1A3074635) to MYC.INTRODUCTION MATERIALS AND METHODS Study species Population sampling DNA extraction cpDNA-PCR optimum primer selection cpDNA sequence alignment and assembly Haplotype distribution, phylogenetic analyses, and genetic diversity Genetic differentiation and structure Mismatch distribution analysis, neutrality detection, and demographic history ENM and population connectivity Niche comparisons in E-space RESULTS Haplotype distribution and phylogeny Genetic diversity Genetic differentiation and structure Mismatch distribution analysis, neutrality detection, and demographic history ENM and population connectivity Niche comparisons in E-space DISCUSSION Deep genetic and climatic divergence of Cypripedium sect. Flabellinervia in the CJK region: taxonomic considerations Haplotype and nucleotide diversity in Cypripedium sect. Flabellinervia: inference of glacial refugia and demographic history Origin of Korean populations of Cypripedium japonicum Origin of Cypripedium formosanum CONCLUSIONS AUTHOR CONTRIBUTIONS ACKNOWLEDGEMENTS Appendix 1: The cpDNA sequence information of Cypripedium sect. Flabellinervia deposited in the GenBank databas

    The Korean Baekdudaegan Mountains: A Glacial Refugium and a Biodiversity Hotspot That Needs to Be Conserved

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    The Baekdudaegan (BDDG; Figure 1) is a mountain range relatively unknown outside Korea. From recent times, however, the BDDG is known outside Korea because it shelters the small county of Pyeongchang, the venue of the 2018 Winter Olympic Games.This research was supported by Korea Research Foundation grants; KRF-2013R1A1A2063524 to MYC and NRF-2011-0017236, NRF-2013R1A1A3010892, and NRF-2017R1A2B4012215 to MGC and was carried out as part of the Infrastructure for the Conservation and Restoration of Rare and Endemic Plants in Korea National Arboretum that supported to MGC from 2015 to 2018.Peer reviewe

    Study protocol of cost-effectiveness and cost-utility of a biopsychosocial multidisciplinary intervention in the evolution of non-specific sub-acute low back pain in the working population: cluster randomised trial.

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain (LBP), with high incidence and prevalence rate, is one of the most common reasons to consult the health system and is responsible for a significant amount of sick leave, leading to high health and social costs. The objective of the study is to assess the cost-effectiveness and cost-utility analysis of a multidisciplinary biopsychosocial educational group intervention (MBEGI) of non-specific sub-acute LBP in comparison with the usual care in the working population recruited in primary healthcare centres. Methods/design: The study design is a cost-effectiveness and cost-utility analysis of a MBEGI in comparison with the usual care of non-specific sub-acute LBP.Measures on effectiveness and costs of both interventions will be obtained from a cluster randomised controlled clinical trial carried out in 38 Catalan primary health care centres, enrolling 932 patients between 18 and 65 years old with a diagnosis of non-specific sub-acute LBP. Effectiveness measures are: pharmaceutical treatments, work sick leave (% and duration in days), Roland Morris disability, McGill pain intensity, Fear Avoidance Beliefs (FAB) and Golberg Questionnaires. Utility measures will be calculated from the SF-12. The analysis will be performed from a social perspective. The temporal horizon is at 3 months (change to chronic LBP) and 12 months (evaluate the outcomes at long term. Assessment of outcomes will be blinded and will follow the intention-to-treat principle. Discussion: We hope to demonstrate the cost-effectiveness and cost-utility of MBEGI, see an improvement in the patients' quality of life, achieve a reduction in the duration of episodes and the chronicity of non-specific low back pain, and be able to report a decrease in the social costs. If the intervention is cost-effectiveness and cost-utility, it could be applied to Primary Health Care Centres. Trial registration: ISRCTN: ISRCTN5871969

    Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

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    The yield of charged particles associated with high-pTp_{\rm T} trigger particles (8<pT<158 < p_{\rm T} < 15 GeV/cc) is measured with the ALICE detector in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV relative to proton-proton collisions at the same energy. The conditional per-trigger yields are extracted from the narrow jet-like correlation peaks in azimuthal di-hadron correlations. In the 5% most central collisions, we observe that the yield of associated charged particles with transverse momenta pT>3p_{\rm T}> 3 GeV/cc on the away-side drops to about 60% of that observed in pp collisions, while on the near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/350

    On the causes of economic growth in Europe: why did agricultural labour productivity not converge between 1950 and 2005?

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    The objective of this study is to make a further contribution to the debate on the causes of economic growth in the European Continent. It explains why agricultural labour productivity differences did not converge between 1950 and 2005 in Europe. We propose an econometric model, one combining both proximate and fundamental causes of economic growth. The results show that the continuous exit of labour power from the sector, coupled with the increased use of productive factors originating in other sectors of the economy, caused the efficiency of agricultural workers to rise. However, we offer a complete explanation of the role played by institutions and geographical factors. Thus, we detect a direct and inverse relation between membership of the EU and the Communist bloc and the productivity of agricultural labour. In addition, strong support for agriculture affected productivity negatively
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