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Anmol Kumar Jaakko Kopra K?rt Varendi Lauriina L. Porokuokka Anne Panhelainen Satu Kuure Pepin Marshall Nina Karalija Mari-Anne H?rma Carolina Vilenius Kersti Lillev?li Triin Tekko Jelena Mijatovic Nita Pulkkinen Madis Jakobson Maili Jakobson Roxana Ola Erik Palm Maria Lindahl Ingrid Str?mberg Vootele V?ikar T. Petteri Piepponen Mart Saarma Jaan-Olle Andressoo 《PLoS genetics》2016,12(1)
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Dispersal limitation and long-term persistence are known to delay plant species’ responses to habitat fragmentation, but it
is still unclear to what extent landscape history may explain the distribution of dispersal traits in present-day plant communities.
We used quantitative data on long-distance seed dispersal potential by wind and grazing cattle (epi- and endozoochory), and
on persistence (adult plant longevity and seed bank persistence) to quantify the linkages between dispersal and persistence
traits in grassland plant communities and current and past landscape configurations. The long-distance dispersal potential
of present-day communities was positively associated with the amounts of grassland in the historical (1835, 1938) landscape,
and with a long continuity of grazing management—but was not associated with the properties of the current landscape. The
study emphasises the role of history as a determinant of the dispersal potential of present-day grassland plant communities.
The importance of long-distance dispersal processes has declined in the increasingly fragmented modern landscape, and long-term
persistent species are expected to play a more dominant role in grassland communities in the future. However, even within
highly fragmented landscapes, long-distance dispersed species may persist locally—delaying the repayment of the extinction
debt. 相似文献
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Geimanen J Isok-Paas H Pipitch R Salk K Laos T Orav M Reinson T Ustav M Ustav M Ustav E 《Journal of virology》2011,85(7):3315-3329
We found that recircularized high-risk (type 16 and 18) and low-risk mucosal (type 6b and 11) and cutaneous (type 5 and 8) human papillomavirus (HPV) genomes replicate readily when delivered into U2OS cells by electroporation. The replication efficiency is dependent on the amount of input HPV DNA and can be followed for more than 3 weeks in proliferating cell culture without selection. Cotransfection of recircularized HPV genomes with a linear G418 resistance marker plasmid has allowed subcloning of cell lines, which, in a majority of cases, carry multicopy episomal HPV DNA. Analysis of the HPV DNA status in these established cell lines showed that HPV genomes exist in these cells as stable extrachromosomal oligomers. When the cell lines were cultivated as confluent cultures, a 3- to 10-fold amplification of the HPV genomes per cell was induced. Two-dimensional (2D) agarose gel electrophoresis confirmed amplification of mono- and oligomeric HPV genomes in these confluent cell cultures. Amplification occurred as a result of the initiation of semiconservative two-dimensional replication from one active origin in the HPV oligomer. Our data suggest that the system described here might be a valuable, cost-effective, and efficient tool for use in HPV DNA replication studies, as well as for the design of cell-based assays to identify potential inhibitors of all stages of HPV genome replication. 相似文献
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Background
No study has explored the risk of metabolic syndrome (MS) in patients with epilepsy treated with valproate (VPA) at the population level. The aim of this study was to compare the risk of MS in VPA-treated patients in Estonia to the risk in the general population.Methods
This study involved 118 patients with epilepsy (63 men, 55 women) who received VPA monotherapy. MS was diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Data were compared with the results of a population-based study of the prevalence of MS in the same geographic region (N = 493; 213 men, 280 women).Results
In the multiple logistic regression analysis, after adjustment for age and sex, the risk of MS in VPA-treated patients was not increased compared to the control subjects (odds ratio [OR] = 1.00; 95% confidence interval [CI], 0.59–1.68). VPA-treated patients had higher serum insulin concentrations than control subjects, independent of body mass index (BMI). A positive association was found between MS development and BMI (OR = 1.47; 95% CI, 1.25–1.73) in VPA-treated patients, but there were no associations with the VPA dosage or the homeostasis model assessment-estimated insulin resistance (HOMA-IR) index. In control subjects, BMI and HOMA-IR had similar predictive abilities for MS occurrence. In VPA-treated patients, the predictive ability of the HOMA-IR index was significantly lower than that of BMI, with areas under the receiver operating characteristic curves of 0.808 and 0.897 (P = 0.05), respectively.Conclusions
The risk of MS is not increased among VPA-treated patients with epilepsy in Estonia compared to the general population. The HOMA-IR index likely has a lower predictive ability for MS in VPA-treated patients compared to its predictive ability in the general population. 相似文献10.
Triin Triisberg Edgar Karofeld Jaan Liira Mall Orru Rein Ramst Jaanus Paal 《Restoration Ecology》2014,22(1):31-39
The natural recovery of vegetation on abandoned peat extraction areas lasts for decades and the result of restoration succession can be unpredictable. The aim of the study was to specify environmental factors that affect the formation of the pioneer stages of mire communities and, therefore, be helpful in the prediction of the resulting ecosystem properties. We used the national inventory data from 64 milled peatlands in Estonia, distributed over the region of 300 × 200 km. This is the first national‐scale statistical evaluation of abandoned extracted peatlands. During surveys, vascular plants, bryophytes, and residual peat properties were recorded on three microtopographic forms: flats, ditch margins, and ditches. The microtopography was the main factor distinguishing the composition of plant communities on flats and ditches, while ditch margins resembled flats. The extracted indicator species suggested two successional pathways, toward fen or raised bog community. A single indicator trait—the depth of residual peat, which combines the information about peat properties (e.g. pH, ash content, and trophicity status), predicted the plant community succession in microtopographic habitats. We suggest that peatland management plans about the cost‐efficient restoration of abandoned peat mining areas should consider properties of residual peat layer as the baseline indicator: milled peatfields with thin (<2.3 m) and well‐decomposed residual peat should be restored toward fen vegetation types, whereas sites with thick (>2.3 m) and less decomposed residual peat layer should be restored toward transitional mires or raised bogs. Specific methodological suggestions are provided . 相似文献