| 1. |
- Bi, Cheng, et al.
(författare)
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Experimental grazer exclusion increases pollination reliability and influences pollinator-mediated plant-plant interactions in tibetan alpine meadows
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Ingår i: Alpine Botany. - 1664-2201.
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Tidskriftsartikel (refereegranskat)abstract
- 1. Co-flowering plant species often interact through shared pollinators, with effects ranging from positive (facilitation) to negative (competition). It remains unclear how this variation relates to variation in floral density, floral trait distinctiveness, and local environmental conditions. We studied the effect of grazer exclusion, a proposed local management strategy, on pollinator-mediated plant-plant interactions in heavily degraded alpine meadows of the Qinghai-Tibet Plateau. 2. We studied the effect of experimental grazer exclusion on plant reproduction and pollinator-mediated reproductive interactions quantified through pollen transfer networks. We also explored potential mechanisms of pollinator-mediated interspecific pollen transfer and its effect on plant reproductive fitness, including local floral abundance and floral trait distinctiveness among co-flowering species. 3. Grazer exclusion led to greater pollen deposition onto stigmas. The overall quantitative effects of pollinator-mediated interspecific interactions on the receptor species were mainly positive (facilitative) or neutral (with no detectable effect). The frequency of positive relative to negative quantitative effects for pairwise donor-receptor pairs tended to increase after grazer exclusion. Plants with floral traits similar to those of local ‘hub species’ appeared to benefit from pollinator-mediated interactions. 4. Our results suggest an overall positive effect of excluding grazers during the plant growing season on plant reproduction. Facilitative species interactions predominate in harsh environments such as the alpine, and the benefits of pollinator-mediated interactions among plants seemed to exceed the cost of conspecific pollen loss associated with pollinator sharing. This suggest that species invasions into alpine plant communities, an expected consequence of climate change, may not necessarily have negative effects on the reproduction of resident plant species.
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| 2. |
- Dai, Qile, et al.
(författare)
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OTTERS: a powerful TWAS framework leveraging summary-level reference data
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Most existing TWAS tools require individual-level eQTL reference data and thus are not applicable to summary-level reference eQTL datasets. The development of TWAS methods that can harness summary-level reference data is valuable to enable TWAS in broader settings and enhance power due to increased reference sample size. Thus, we develop a TWAS framework called OTTERS (Omnibus Transcriptome Test using Expression Reference Summary data) that adapts multiple polygenic risk score (PRS) methods to estimate eQTL weights from summary-level eQTL reference data and conducts an omnibus TWAS. We show that OTTERS is a practical and powerful TWAS tool by both simulations and application studies.
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| 3. |
- Jin, Rong, et al.
(författare)
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Congener-specific determination of ultratrace levels of chlorinated and brominated polycyclic aromatic hydrocarbons in atmosphere and industrial stack gas by isotopic dilution gas chromatography/high resolution mass spectrometry method
- 2017
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1509, s. 114-122
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Tidskriftsartikel (refereegranskat)abstract
- Isotopic dilution gas chromatography combined with high resolution mass spectrometry (GC/HRMS) has overwhelming advantages with respect to the accuracy of congener-specific ultratrace analysis of complex persistent organic pollutants (POPs) in environmental matrices. However, an isotopic dilution GC/HRMS method for analysis of chlorinated and brominated polycyclic aromatic hydrocarbons (Cl-PAHs and Br-PAHs) using 13C-labelled congeners as internal standards has not been established. In this study, a method for identification and quantification of 38 congeners of Cl-PAHs and Br-PAHs in atmosphere and stack gas samples from waste incinerators was developed using the isotopic dilution GC/HRMS technique. The instrumental detection limits of the GC/HRMS method ranged from 0.2pg to 1.8pg for Cl-PAH congeners, and 0.7pg to 2.7pg for Br-PAH congeners, which were about three orders of magnitude lower than those of the GC/quadrupole MS method. This new method developed was also the first to enable determination of Cl-PAH and Br-PAH homologs comprising congeners with the same molecular skeleton and chlorine or bromine substitution numbers. Among the detected congeners, seven Cl-PAH congeners and thirteen Br-PAH congeners that were abundant in the atmosphere and stack gases released from waste incinerators were firstly detected in real samples and reported using the established isotopic dilution GC/HRMS method. The developed isotopic dilution GC/HRMS is significant and needed for better studying the environmental behavior and health risk of Cl-PAHs and Br-PAHs.
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| 4. |
- Jin, Rong, et al.
(författare)
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Profiles, sources and potential exposures of parent, chlorinated and brominated polycyclic aromatic hydrocarbons in haze associated atmosphere
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 593-594, s. 390-398
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Tidskriftsartikel (refereegranskat)abstract
- Profiles, sources and potential exposures of chlorinated and brominated polycyclic aromatic hydrocarbons (ClPAHs and BrPAHs) in haze associated atmosphere remain unclear. Haze events happened frequently during heating period in Beijing provided a typical urban context to investigate the concentrations, profiles, sources and potential exposures of ClPAHs, BrPAHs and their non-halogenated parent compounds (PAHs) in air samples. Average concentrations of PAHs, ClPAHs and BrPAHs during heating periods (with more frequent haze events) were about 3-9 times higher than during non-heating periods. Concentrations of particulate matter (PM)-associated ClPAHs and BrPAHs were higher in heating period than in non-heating period, while for gas-associated ClPAHs and BrPAHs, this distinction was not significant. Congener patterns and congener profiles indicated that with increasing coal combustion during the heating period, concentrations of PAHs and ClPAHs in air were elevated in comparison to the non-heating period. Inhalation of PM-associated PAHs, ClPAHs and BrPAHs accounted for higher exposure than inhalation of gas phase and dermal contact of both gas phase and particulate phase. In this study we found that the particulate phase is the dominant exposure pathway of atmospheric PAHs, ClPAHs and BrPAHs during haze days, which is different from previous studies.
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| 5. |
- Lee, James J, et al.
(författare)
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Gene discovery and polygenic prediction from a genome-wide association study of educational attainment in 1.1 million individuals.
- 2018
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 50:8, s. 1112-1121
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Tidskriftsartikel (refereegranskat)abstract
- Here we conducted a large-scale genetic association analysis of educational attainment in a sample of approximately 1.1million individuals and identify 1,271independent genome-wide-significant SNPs. For the SNPs taken together, we found evidence of heterogeneous effects across environments. The SNPs implicate genes involved in brain-development processes and neuron-to-neuron communication. In a separate analysis of the X chromosome, we identify 10independent genome-wide-significant SNPs and estimate a SNP heritability of around 0.3% in both men and women, consistent with partial dosage compensation. A joint (multi-phenotype) analysis of educational attainment and three related cognitive phenotypes generates polygenic scores that explain 11-13% of the variance in educational attainment and 7-10% of the variance in cognitive performance. This prediction accuracy substantially increases the utility of polygenic scores as tools in research.
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| 6. |
- Ma, Tao, et al.
(författare)
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Genomic insights into salt adaptation in a desert poplar
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2797-
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Tidskriftsartikel (refereegranskat)abstract
- Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.
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| 7. |
- Smith, Jennifer A, et al.
(författare)
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Genome-wide association study identifies 74 loci associated with educational attainment
- 2016
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Ingår i: Nature (London). - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 533:7604, s. 539-542
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Tidskriftsartikel (refereegranskat)abstract
- Educational attainment is strongly influenced by social and other environmental factors, but genetic factors are estimated to account for at least 20% of the variation across individuals. Here we report the results of a genome-wide association study (GWAS) for educational attainment that extends our earlier discovery sample of 101,069 individuals to 293,723 individuals, and a replication study in an independent sample of 111,349 individuals from the UK Biobank. We identify 74 genome-wide significant loci associated with the number of years of schooling completed. Single-nucleotide polymorphisms associated with educational attainment are disproportionately found in genomic regions regulating gene expression in the fetal brain. Candidate genes are preferentially expressed in neural tissue, especially during the prenatal period, and enriched for biological pathways involved in neural development. Our findings demonstrate that, even for a behavioural phenotype that is mostly environmentally determined, a well-powered GWAS identifies replicable associated genetic variants that suggest biologically relevant pathways. Because educational attainment is measured in large numbers of individuals, it will continue to be useful as a proxy phenotype in efforts to characterize the genetic influences of related phenotypes, including cognition and neuropsychiatric diseases.
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| 8. |
- Wahl, Simone, et al.
(författare)
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Epigenome-wide association study of body mass index, and the adverse outcomes of adiposity
- 2017
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Ingår i: Nature. - : NATURE PUBLISHING GROUP. - 0028-0836 .- 1476-4687. ; 541:7635, s. 81-
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Tidskriftsartikel (refereegranskat)abstract
- Approximately 1.5 billion people worldwide are overweight or affected by obesity, and are at risk of developing type (2) diabetes, cardiovascular disease and related metabolic and inflammatory disturbances(1,2). Although the mechanisms linking adiposity to associated clinical conditions are poorly understood, recent studies suggest that adiposity may influence DNA methylation(3-6), a key regulator of gene expression and molecular phenotype(7). Here we use epigenome-wide association to show that body mass index (BMI; a key measure of adiposity) is associated with widespread changes in DNA methylation (187 genetic loci with P < 1 x 10(-7), range P = 9.2 x 10(-8) to 6.0 x 10(-46); n = 10,261 samples). Genetic association analyses demonstrate that the alterations in DNA methylation are predominantly the consequence of adiposity, rather than the cause. We find that methylation loci are enriched for functional genomic features in multiple tissues (P < 0.05), and show that sentinel methylation markers identify gene expression signatures at 38 loci (P < 9.0 x 10(-6), range P = 5.5 x 10(-6) to 6.1 x 10(-35), n = 1,785 samples). The methylation loci identify genes involved in lipid and lipoprotein metabolism, substrate transport and inflammatory pathways. Finally, we show that the disturbances in DNA methylation predict future development of type 2 diabetes (relative risk per 1 standard deviation increase in methylation risk score: 2.3 (2.07-2.56); P = 1.1 x 10(-54)). Our results provide new insights into the biologic pathways influenced by adiposity, and may enable development of new strategies for prediction and prevention of type 2 diabetes and other adverse clinical consequences of obesity.
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| 9. |
- Yang, Jinghai, et al.
(författare)
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Investigation on the origin of green light emission in ZnO bulk materials
- 2009
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Ingår i: INTERNATIONAL JOURNAL OF MATERIALS and PRODUCT TECHNOLOGY. - 0268-1900. ; 34:3, s. 360-368
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Tidskriftsartikel (refereegranskat)abstract
- ZnO bulk materials were implanted by O and Zn with different concentration and their photoluminescence (PL) properties were investigated in detail. The results clearly show that O and Zn implantation indeed have great influence on the green light emission. By comparing the PL spectra for the samples with different implantations, O-i, Zn-i and Cu-related defects have been excluded from the possibility of the origin of green light emission step by step. Finally, it can be concluded that V-Zn is responsible to the observed green light emission, which has good agreement with the theoretical results from first principle calculation.
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| 10. |
- Berndt, Sonja I., et al.
(författare)
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Genome-wide meta-analysis identifies 11 new loci for anthropometric traits and provides insights into genetic architecture
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:5, s. 501-U69
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Tidskriftsartikel (refereegranskat)abstract
- Approaches exploiting trait distribution extremes may be used to identify loci associated with common traits, but it is unknown whether these loci are generalizable to the broader population. In a genome-wide search for loci associated with the upper versus the lower 5th percentiles of body mass index, height and waist-to-hip ratio, as well as clinical classes of obesity, including up to 263,407 individuals of European ancestry, we identified 4 new loci (IGFBP4, H6PD, RSRC1 and PPP2R2A) influencing height detected in the distribution tails and 7 new loci (HNF4G, RPTOR, GNAT2, MRPS33P4, ADCY9, HS6ST3 and ZZZ3) for clinical classes of obesity. Further, we find a large overlap in genetic structure and the distribution of variants between traits based on extremes and the general population and little etiological heterogeneity between obesity subgroups.
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