We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetabl...We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by highperformance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g),whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers展开更多
We studied variations in tree biomass and carbon sequestration rates of Chir Pine (Pinus roxburghii. Sarg.) forest in three categories of forest disturbance, protected, moderately disturbed, and highly disturbed. In...We studied variations in tree biomass and carbon sequestration rates of Chir Pine (Pinus roxburghii. Sarg.) forest in three categories of forest disturbance, protected, moderately disturbed, and highly disturbed. In the first year, total biomass was 14.7.t.ha-1 in highly disturbed site, 94.46 t.ha-1 in moderately disturbed forest, and 112.0 t.ha-1 in protected forest. The soil organic carbon in the top 20 cm of soil ranged from 0.63 to 1.2%. The total rate of carbon sequestration was 0.60 (t/ha).a-lon the highly disturbed site, 1.03 (t/ha)a-1 on the moderately disturbed site, and 4.3 (t/ha).a-1 on the protectedsite. Keywords: carbon sequestration, soil organic carbon (SOC), disturbed forest, vegetation analysis, allometric equations展开更多
Forest and vegetation of particular ecosystem is generally influenced by external factors especially from development activities. Nepal has been endowed with an immense variety of forest resources with its unique biod...Forest and vegetation of particular ecosystem is generally influenced by external factors especially from development activities. Nepal has been endowed with an immense variety of forest resources with its unique biodiversity. The current study is conducted in the temperate forest of central Nepal to compare the state of vegetation recorded during 1995 with the present condition. To identify floristic composition, species distribution and diversity, same location and same size of quadrates were selected in natural forest and planted or regenerated area as in previous study. Measurement and analytical tools for forest and vegetation reveled a total of 19 species and 341 individuals in 0.14 ha regenerated area and 18 species, 17 genera and 260 individuals in 0.16 ha, natural forest areas. However, in 1995, total 31 individuals of 20 woody species, 18 genera and 15 families were recorded within the sampling plots of 0.16 ha of natural forest. Moreover, Alnus nepalensis is found dominating regenerated area and Caryopteris odorata in natural forests whereas in 1995, Litsea chartacea and Maesa chisia were recorded dominant. The Shannon’s diversity H’ = 2.908, E = 0.970 and Var H’ = -0.00 and Simpsons D = 0.027 recorded in 1995 is found to be with higher values when compared with the analysis of present study. Furthermore, in comparison to 1995 study, this study showed lower basal area and timber volume with declining species diversity. Although, the natural forest is found with higher species composition compared to rehabilitated forest, species of herbs and shrubs were found extensively growing.展开更多
文摘We have examined the carotenoid contents of several dark green vegetables found to be associated with a lower risk of various epithelial cancers in our epidemiological study and animal study. Samples of these vegetables were quantitatively examined by highperformance liquid chromatography (HPLC) on a C-18 reversed-phase column for individual carotenoid content. Pure reference compounds (alpha-carotene, beta-carotent, lycopene, canthaxanthin, and lutein) and internal standard (beta-Apo-8'-carotenal) were employed to quantify xanthophylls and carotenes in these vegetables. The results indicated that fresh, dark-green, leafy vegetables were high in beta-carotene (0.94-9.36 mg/100 g) and oxygenated carotenoids or xanthophylls, primarily lutein (0.94-7.39 mg/100 g),whereas lycopene and alpha-carotene were not prominent and canthaxanthin was non existent in these vegetables. These analyses suggest that consumption of carotenoids such as lutein in addition to beta-carotene may be associated with a lower risk of cancers
文摘We studied variations in tree biomass and carbon sequestration rates of Chir Pine (Pinus roxburghii. Sarg.) forest in three categories of forest disturbance, protected, moderately disturbed, and highly disturbed. In the first year, total biomass was 14.7.t.ha-1 in highly disturbed site, 94.46 t.ha-1 in moderately disturbed forest, and 112.0 t.ha-1 in protected forest. The soil organic carbon in the top 20 cm of soil ranged from 0.63 to 1.2%. The total rate of carbon sequestration was 0.60 (t/ha).a-lon the highly disturbed site, 1.03 (t/ha)a-1 on the moderately disturbed site, and 4.3 (t/ha).a-1 on the protectedsite. Keywords: carbon sequestration, soil organic carbon (SOC), disturbed forest, vegetation analysis, allometric equations
文摘Forest and vegetation of particular ecosystem is generally influenced by external factors especially from development activities. Nepal has been endowed with an immense variety of forest resources with its unique biodiversity. The current study is conducted in the temperate forest of central Nepal to compare the state of vegetation recorded during 1995 with the present condition. To identify floristic composition, species distribution and diversity, same location and same size of quadrates were selected in natural forest and planted or regenerated area as in previous study. Measurement and analytical tools for forest and vegetation reveled a total of 19 species and 341 individuals in 0.14 ha regenerated area and 18 species, 17 genera and 260 individuals in 0.16 ha, natural forest areas. However, in 1995, total 31 individuals of 20 woody species, 18 genera and 15 families were recorded within the sampling plots of 0.16 ha of natural forest. Moreover, Alnus nepalensis is found dominating regenerated area and Caryopteris odorata in natural forests whereas in 1995, Litsea chartacea and Maesa chisia were recorded dominant. The Shannon’s diversity H’ = 2.908, E = 0.970 and Var H’ = -0.00 and Simpsons D = 0.027 recorded in 1995 is found to be with higher values when compared with the analysis of present study. Furthermore, in comparison to 1995 study, this study showed lower basal area and timber volume with declining species diversity. Although, the natural forest is found with higher species composition compared to rehabilitated forest, species of herbs and shrubs were found extensively growing.