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51.
The efficiency of sample-based indices proposed to quantify the spatial distribution of trees is influenced by the structure of tree stands, environmental heterogeneity and degree of aggregation. We evaluated 10 commonly used distance-based and 10 density-based indices using two structurally different stands of wild pistachio trees in the Zagros woodlands, Iran, to assess the reliability of each in revealing stand structure in woodlands. All trees were completely stem-mapped in a nearly pure (40 ha) and a mixed (45 ha) stand. First, the inhomogeneous pair correlation function [g(r)] and the Clark–Evans index (CEI) were used as references to reveal the true spatial arrangement of all trees in these stands. The sampled data were then evaluated using the 20 indices. Sampling was undertaken in a grid based on a square lattice using square plots (30 m × 30 m) and nearest neighbor distances at the sample points. The g(r) and CEI statistics showed that the wild pistachio trees were aggregated in both stands, although the degree of aggregation was markedly higher in the pure stand. Three distance- and six density-based indices statistically verified that the wild pistachio trees were aggregated in both stands. The distance-based Hines and Hines statistic (h t ) and the density-based standardised Morisita (I p ), patchiness (IP) and Cassie (C A ) indices revealed aggregation of the trees in the two structurally different stands in the Zagros woodlands and the higher clumping in the pure stand, whereas the other indices were not sensitive enough. 相似文献
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HAN Li-hui SUN Wen-sheng JIA Xiao-qing LIU Su-xia WANG Xiao-yan GAO Li-fen CAO Ying-lin Yousef Abu-kwaik 《园艺学报》2005,21(9):1665-1668
AIM: To explore the relationship between caspase activation and the evasion of Legionella from macrophage elimination through a Legionella-infected macrophage model. METHODS: After infected by Legionella, the activity of caspase 3 in macrophages was analyzed by confocal microscopy as well as fluorescence reader. Growth and replication of Legionella in macrophage was assayed. Replication of Legionella was analyzed again to see the effect of caspase 3 inhibition on the growth of Legionella after use of caspase 3 inhibitor. RESULTS: Both confocal microscopy and caspase 3 fluorescent substrate analysis showed that Legionella virulent strain had powerful capability of activating caspase 3 while the mutant non-virulent strain did not have this capability. The virulent strain highly replicated in macrophages and the replication was significantly inhibited by caspase 3 inhibitor. CONCLUSION: Our results indicate that the intracellular caspase 3 is activated shortly after infection by Legionella virulent strain. The evasion of Legionella from the elimination of macrophages may be mediated by caspase 3 activation to a great degree. 相似文献
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Brassica oleracea vegetables, such as broccoli (B. oleracea L. var. italica) and cauliflower (B. oleracea L. var. botrytis), are known to contain bioactive compounds associated with health, including three classes of photosynthetic lipid-soluble compounds: carotenoids, chlorophylls, and tocopherols. Carotenoids and chlorophylls are photosynthetic pigments. Tocopherols have vitamin E activity. Due to genetic and environmental variables, the amounts present in vegetables are not constant. To aid breeders in the development of Brassica cultivars with higher provitamin A and vitamin E contents and antioxidant activity, a more efficient method was developed to quantitate carotenoids, chlorophylls, and tocopherols in the edible portions of broccoli and cauliflower. The novel UPLC method separated five carotenoids, two chlorophylls, and two tocopherols in a single 30 min run, reducing the run time by half compared to previously published protocols. The objective of the study was to develop a faster, more effective extraction and quantitation methodology to screen large populations of Brassica germplasm, thus aiding breeders in producing superior vegetables with enhanced phytonutrient profiles. 相似文献
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Reppert A Yousef GG Rogers RB Lila MA 《Journal of agricultural and food chemistry》2008,56(17):7860-7865
Isoflavones have potential for preventing and treating several chronic health conditions, such as osteoporosis, cardiovascular disease, and cancer. In this study, radiolabeled isoflavones were recovered from kudzu (Pueraria lobata) root cultures after incubation with uniformly labeled (14)C-sucrose in the culture medium for 21 days. Approximately 19% of administered label was recovered in the isoflavone-rich dried extracts of kudzu root cultures (90.2 microCi/g or 3.3 MBq/g extract). HPLC-PDA analysis revealed the predominant isoflavones isolated from kudzu root cultures to be puerarin, daidzin, and malonyl-daidzin. The average concentration of the major isoflavone puerarin in kudzu root cultures was 33.6 mg/g extract, with a specific activity of 63.5 microCi/g (2.3 MBq/g). The isolated isoflavones were sufficiently (14)C-labeled to permit utilization for subsequent in vivo metabolic tracking studies. 相似文献
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What are the drivers of the occurrence of illegal fishing and conservation barriers of sturgeons in the Caspian Sea?
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Seyed Mostafa Aghilinejhad Saeid Gorgin Daan van Uhm Ramtin Joolaie Rasoul Ghorbani Seyed Yousef Paighambari Jahangir Mohammadi Ali Jalali 《水产资源保护:海洋与淡水生态系统》2018,28(3):690-701
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To evaluate the effects of different level of Na salinity (0, 3, 6 and 9 dS m(-1)) on growth, yield and yield component of Kabuli (Hashem and Jam) and Desi (Kaka and Pirooz) chickpea cultivars a factorial experiment based on randomized complete block design with four replications was carried out in Research Greenhouse of Mokrian Agricultural Extension Center near Mahabad, Iran at 2006. Seeds of four chickpea cultivars were grown under 0, 3, 6 and 9 dS m(-1) levels of salinity until maturity. Salinity reduced the plant growth, flower, pod and seed number and seed weight. As increase in salinity, the undesirable effect of Na+ was more pronounced and reached the highest value at 9 dS m(-1) in all cultivars. Four chickpea cultivar have different responses to salinity and the Kabuli cultivars seemed to have a greater capacity for salt tolerance compared to Desi cultivars. Hahshem cultivar has the highest salinity tolerance among all cultivars. 相似文献