[Construction of ecological corridors in Changli County based on ecological sensitivity and ecosystem service values.] / 基于生态敏感性和生态系统服务价值的昌黎县生态廊道构建.

Ecological corridors provide essential routes for biological migration, which would promote species exchange among different habitats. The construction of corridors is beneficial to alle-viate the damages caused by the fragmentation of landscapes due to the acceleration of urbanization, with significance to biodiversity conservation. In this study, we located the ecological sources with the results of ecological sensitivity evaluation and ecosystem service value analysis in Changli County based on its land use status in 2015. Then, we produced the potential corridors with the minimal cumulative resistance model (MCR) and the minimum cost path method, and identified the key corridors with the gravity model. We put forward the ecological corridor system including four important corridors and two general corridors to underpin the scientific knowledge for the ecological corridor construction project and biodiversity conservation. The results showed that the ecological sensitivity of this area was relatively moderate and ecosystem services value was relatively low. Both the ecological sensitivity and ecosystem services were lower in the middle area but higher in around areas. The ecological sources were mainly distributed in the northern Jieshi Mountain Scenic Area, the eastern coastal state-owned forest farm and the western water source conservation area, which were highly coincident with the nature reserves determined by Ecological Environment Construction and Protection Planning (2011-2030) in the study area. The total length of the corridors was 112.66 km, within which the length of important ones was 47.61 km and that of general ones was 65.05 km. The best width of the corridors was around 30 to 60 m. The ecological corridors and ecological sources constituted an annular closed area, which would effectively promote species migration and the exchange of material and energy.

Matrix Metalloproteinase-3 -1171 5A/6A Polymorphism (rs35068180) is Associated with Risk of Periodontitis.

Matrix metalloproteinase-3 (MMP3) plays a key role in tissue degradation in periodontitis. The relationship between the MMP3 -1171 5A/6A polymorphism (rs35068180) and periodontitis has been widely studied. However, existing studies have yielded contradictory results. We therefore conducted a meta-analysis to comprehensively investigate these inconclusive findings. Several electronic databases were searched for eligible articles. Seven case-control studies from 6 articles were searched without any language restrictions. Pooled estimates indicated that MMP3 -1171 5A/6A polymorphism is associated with a decreased risk of periodontitis (allelic genetic model: OR = 0.70, 95% CI: 0.62-0.80, P(heterogeneity) = 0.315; heterozygous model: OR = 0.50, 95% CI: 0.39-0.65, P(heterogeneity) = 0.221; homozygous model: OR = 0.42, 95% CI: 0.25-0.69, P(heterogeneity) = 0.265; dominant model: OR = 0.49, 95% CI: 0.38-0.62, P(heterogeneity) = 0.238, respectively). Similar results were also found in chronic periodontitis (CP), Asian, Asian&CP, and non-smokers subgroups. Moreover, MMP3 rs35068180 polymorphism might be associated with a lower risk of aggressive periodontitis (AgP) in Asians (allelic genetic model: OR = 0.66, 95% CI: 0.48-0.91, P(heterogeneity) = 0.945), and CP in Caucasians and Brazilians. In conclusion, this meta-analysis demonstrates that MMP3 -1171 5A/6A polymorphism may be associated with decreased risk of both CP and AgP in Asians. Large independent studies to replicate these results are necessary to validate these associations in other populations.