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31.
Russian Journal of Ecology - 相似文献
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四种南京地产栽培野菜蛋白质营养价值的评价研究 总被引:13,自引:0,他引:13
4种传统野菜已在南京地区规模栽培利用。采用模糊识别法和氨基酸比值系数法,分别以鸡蛋蛋白质为标准蛋白 ,以WHO/FAO氨基酸参考模式为评价标准 ,对这4种野菜蛋白质营养价值进行了评价 ,并与6种常见蔬菜蛋白进行对照比较。结果表明 ,4种野菜蛋白质含量为2.3 %~5.0 % ,蛋白质中氨基酸种类齐全 ,其含量为77.73 %~89.36 % ,必需氨基酸占总氨基酸量的36.72 %~42.04 % ,第一限制性氨基酸为含硫氨基酸 (Met +Cys)。其蛋白质营养价值分别优于同科的一些常见蔬菜。 相似文献
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对首次发现的一只野化培训大熊猫“祥祥”采食半枯竹的现象及原因进行研究.作者用4只圈养大熊猫为对照进行试验,从行为观察、营养成分及适口因子、环境气候条件等方面进行了研究.研究发现,圈养大熊猫中也存在采食半枯竹的现象,而且在采食的时间段上和祥祥一致;相对于新鲜竹子,半枯竹中葡萄糖含量有所增加,单宁含量明显降低,并且具有特殊的香甜味,使在一定时期内的半枯竹营养增加,适口性得到改善,这是大熊猫在特定时期更愿意采食半枯竹而不采食新鲜竹子的重要原因;7~9月是全年温湿度最高月份,对引起半枯竹成分中适口因子的改变可能有诱发作用.图3表4参9 相似文献
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佛坪三官庙地区大熊猫种群数量的DNA指纹分析 总被引:5,自引:0,他引:5
应用同位素标记大熊猫基因指纹探针F2ZGP96060801,以秦岭南坡中段佛坪国家级大熊猫自然保护区三官庙范围内采集的大熊猫粪便样品作材料,进行了DNA指纹检测.(1)在相同或不同时间、领域采得的粪便样品,显现出相同或不同的DNA指纹图谱,达到个体认定的目的,进一步表明了大熊猫的尽量新鲜的粪便,可以作为DNA指纹分析材料,进行野生种群数量调查.(2)根据检测21个粪便样品的结果,无误地认定了三官庙地区有13只大熊猫个体.其中有3个家系.(3)大熊猫粪便样品的DNA指纹图,通过微机识别的个体数,准确可靠,能获得大熊猫在野外的真实个体数量. 相似文献
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Trace metal levels in freshwater fish, sediment and water 总被引:1,自引:1,他引:1
Sandor Z Csengeri I Oncsik MB Alexis MN Zubcova E 《Environmental science and pollution research international》2001,8(4):265-268
The trace metal concentrations in water, sediment and aquatic organisms, such as fish, could indicate the level and tendency of the pollution. This is important not only for the protection of the environment, but for evaluation of the quality of fish meat either captured from natural waters or cultured in fishponds. The total trace metal concentrations in samples of fish from different regions of Hungary and from different species have been determined by using an X-ray fluorescence technique (EDXRF). Water, sediment and fish samples from fishpond systems with different feeding and stocking has also been analyzed. In the case of zinc contents, differences have been traced between the cultured and wild common carp. In the case of common carp reared under different feeding conditions, differences were also observed in the zinc concentration. The retention of the trace metals in the fish has been studied by measuring the levels in sediment, water and feed. The different retention can be explained by the different availability of zinc in the applied feeds, which can be related to the presence of different metal species in the feeds. 相似文献
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Summary Although present constitutively in large amounts, furanocoumarins in leaves of wild parsnip,Pastinaca sativa, are inducible to even higher concentrations by mechanical and insect damage. We conducted several experiments in order to characterize the nature and extent of xanthotoxin inducibility inP. sativa foliage. In order to determine the extent to which induction is localized, we mechanically damaged a single leaflet of a compound leaf on seven plants. Xanthotoxin concentrations increased significantly only in the damaged leaflet and in the half of the terminal leaflet closest to the damaged leaflet; thus, xanthotoxin induction is localized to the immediate vicinity of damage. To determine whether xanthotoxin induction results fromin situ biosynthesis or translocation from other plant parts, we detached individual leaflets from ten plants, damaged half of these detached leaflets, and compared xanthotoxin concentrations after 6 h in damaged and intact leaflets. We found that xanthotoxin concentrations increased 41% in damaged leaflets compared to detached leaflets that were not damaged. We also determined the rapidity and duration of the induction response. In leaflets that were damaged and then harvested after 0, 3, 24, 72, 120 and 168 h, xanthotoxin concentrations increased rapidly compared to undamaged leaflets on the opposite side of the leaf, reaching maximum levels within 24 h. This response was of comparatively short duration; concentrations declined to preinduction levels after seven days. To determine whether availability of resources influences the induced response, we performed two experiments, one in which soil nutrients were manipulated and one in which light level was manipulated. The low nutrient treatment was sufficiently extreme to cause cessation of aboveground growth, and the low light treatment caused etiolation. Extremes of resource limitation notwithstanding, leaflets significantly increased xanthotoxin production (2 to 3-fold increase under nutrient limitation and 3-fold increase under light limitation) in response to damage in both experiments. 相似文献
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Aase Kristine Lundberg Tim Richardson Eirin Hongslo 《Journal of Environmental Planning and Management》2019,62(2):266-285
This paper seeks to contribute to debates on the potential for conservation planning to engage actively with conflict. Current research in conservation planning generally approaches conflict by concentrating on the challenges of securing agreement and consensus. Recent planning literature advocates approaches that are more open to conflict. In the analysis of a Norwegian regional planning process for wild reindeer conservation, we examine how planning authorities handled conflict, and in particular how planning documents portrayed conflicts expressed during the planning process. Findings show that the aim of reaching regional consensus limited the scope of planning, and led to the exclusion of difficult issues and opposing views. Instead of engaging actively with conflict, the planning authority framed opposing positions as unplannable, and failed to recognise them as legitimate. This contributed to weakening of the legitimacy of the regional plan when put to the test. 相似文献
40.
Overharvesting is one of the greatest threats to species survival. Farming overharvested species is a conservation strategy that can meet growing market demand and conserve wild populations of the target species. This strategy is compatible with the international community's desire to uphold the right of local communities to use biological resources to support their livelihoods. However, studies investigating whether farming can alleviate poaching pressure have focused almost exclusively on animals. To address the shortfall in plant-focused studies, we compiled information on commercial cultivation of threatened plants to assess its conservation benefits. Because China's rising middle class has rapidly intensified demand for wildlife products, we searched the scientific literature published in Chinese (China National Knowledge Infrastructure and Baidu) and in English. We found 32 reports that contained data on 193 internationally or nationally threatened plant species that were under commercial cultivation. These reports showed that cultivations of 82% of the 193 species were sustained by collecting whole plants from the wild periodically or continuously. Although based on a small sample size, species that were maintained in cultivation only through artificial propagation or seeds collected in the wild were likely associated with a reported reduction in wild harvesting of whole plants. Even so, results of correlation analyses suggested that production system, scale, and when a species began being cultivated had little effect on conservation status of the species, either globally or in China. However, species brought into cultivation relatively recently and on a smaller scale were more likely to have undergone a reduction in collecting pressure. Farming of nonmedicinal plants was most problematic for species conservation because wild plants were laundered (i.e., sold as cultivated plants). For effective conservation, policy to guide cultivation operations based on the target species’ biological characteristics, cultural significance, market demand, and conservation status is needed. 相似文献