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Vertical patterns of the flora of seed plants in Dawei Mountain in Yunnan Province, Southwest China
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作者 Wang Juan ma qin-yan +1 位作者 Du Fan Yang Yu-ming 《Forestry Studies in China》 CAS 2007年第3期169-176,共8页
Abstract Vertical gradients incorporate multiple resources gradients which vary continuously. Therefore, research on mountain floristic patterns along vertical gradients is important to reveal regular patterns of the ... Abstract Vertical gradients incorporate multiple resources gradients which vary continuously. Therefore, research on mountain floristic patterns along vertical gradients is important to reveal regular patterns of the flora along environmental gradients and to under- stand the changes in biodiversity along these gradients and their biological fitness. This study was designed to explore the character- istics of the floral compositions and ecological significance of floristic patterns along the vertical gradients of the National Nature Reserve of Dawei Mountain, located in the southeast of Yunnan Province. We analyzed the structural characteristics of the flora and the distribution patterns of its floristic components as a function of elevation on the basis of our field investigations along vertical vegetation transects. We carried out a systematic cluster analysis in order to determine the dividing line of floristic changes by eleva- tion along gradients and studied the effects of mountain climate on the vertical variation of floristic composition. The study shows: 1) that the obvious boundary, which differentiates tropical distribution, is located at an elevation of approximately 1,500 m, which separates the tropical rain forests from the evergreen broad-leaved forests; 2) that humid rain forests are found below 700 m elevation, mountain rain forests between 700 and 1,500 m, monsoon evergreen broad-leaved forests between 1,300 and 1,800 m and mountain mossy evergreen broad-leaved forests above 1,800 m. Non-representative mountain mossy dwarf forests (above 2,100 m) in the area are found on the windward sides and barren lands on mountain slopes; 3) that Hopea mollissima is one of the major component species of mountain rain forests, but it should not be considered as the major indicator species in humid rain forests as is generally accepted. 展开更多
关键词 Dawei Mountain geographical elements vertical gradient cluster analysis
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淋巴细胞/单核细胞比值预测老年结肠高危腺瘤的价值
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作者 孙洁 马沁妍 +3 位作者 查秀芳 桑楠 苏菡 赵君宁 《实用老年医学》 CAS 2021年第4期390-392,397,共4页
目的本研究旨在观察老年人群中结肠高危腺瘤病人淋巴细胞/单核细胞比值(LMR)和其他炎症因子的变化,探讨LMR对老年结肠高危腺瘤的预测价值。方法纳入157例行结肠镜检查的老年病人并收集相关临床资料。采用Logistic回归分析高危腺瘤的危... 目的本研究旨在观察老年人群中结肠高危腺瘤病人淋巴细胞/单核细胞比值(LMR)和其他炎症因子的变化,探讨LMR对老年结肠高危腺瘤的预测价值。方法纳入157例行结肠镜检查的老年病人并收集相关临床资料。采用Logistic回归分析高危腺瘤的危险因素,采用ROC曲线评价LMR对结肠高危腺瘤的预测价值。结果单因素分析表明,单核细胞计数、LMR和中性粒细胞/淋巴细胞比值(NLR)是高危腺瘤的影响因素(P<0.05)。Logistic回归分析显示,LMR是高危腺瘤的独立危险因素。ROC曲线分析表明,LMR预测高危腺瘤的灵敏度为65.6%,特异性为70.4%(AUC=0.720,P<0.001),LMR最佳截断值为4.49。结论LMR与老年结肠高危腺瘤有关,可作为预测结肠高危腺瘤新的生物标志物。 展开更多
关键词 结肠腺瘤 淋巴细胞/单核细胞比值 炎症因子 老年人
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