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Marine sponges can produce allelopathic compounds with specific roles in the competition for benthic space. Here we demonstrate that extracts from Callyspongia samarensis (Phylum Porifera) accelerate bleaching in Porites cylindrica (Phylum Cnidaria, Order Scleractinia) and exhibit in vitro anticancer activity. A column chromatography fraction and HPLC fraction, purified from the crude methanol extract of C. samarensis, were incorporated into agar gel cubes at natural concentrations and tested on P. cylindrica corals in a laboratory assay. Statistical analysis of percent bleached area and maximum quantum yield showed that a significant difference existed between P. cylindrica nubbins that were exposed to C. samarensis extracts versus the control group. This suggests that C. samarensis contains allelopathic compounds that can cause bleaching in P. cylindrica, possibly leading to tissue necrosis and death. Furthermore, the aforementioned HPLC fraction exhibited significant growth inhibition of the HCT-116 (human colon cancer) cell line. Understanding the strategies by which sponges exert dominance over other organisms is important because it provides information about the ecological roles of sponge allelopathy and can result in the discovery of compounds with biomedical potential.  相似文献   
2.
The trophic dynamics of Bagré reservoir which has been recently impounded in Burkina Faso was based on the data collected during 1997–1998 period using the Ecopath model and software. Total fish biomass is 22.63 t km−2 and mainly represents trophic levels (TLs) 2 and 3. The trophic food chain is relatively long and the overall transfer efficiency is quite low. Grazing foodweb based on primary producers is prominent in the reservoir ecosystem and detritus plays a less significant role. Seasonal and long-term variations in water quality have significant influences on the lower TLs clearly showing a bottom-up functioning of the ecosystem. Environmental degradations, such as siltation occurring in the lake, suggest possible risks in limiting ecosystem productivity.  相似文献   
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As is the case to date with respect to sustainability indicators, there is an enormous quantity of information available about their basic components (social, economic and environmental), but these are generally dealt with in a sectoral and fragmented manner, and the components have been analysed and approached in a more or less independent fashion. On the other hand, it is difficult to find indicators that encompass all the dimensions of sustainability. The topic chosen for this research is sustainability organised in a systematic fashion, which entails taking the combination of issues that affect each subsystem and investigating the states of territorial adjustment that exist between each of them. In short, it is the possibility of establishing a sustainable territorial development pattern, accepting that the economic and social activities that utilise the natural resources influence sustainability, and that they will do so to a greater or lesser extent depending on the effectiveness of the conservation of the stock of resources. The Territorial Adjustment Indicator System (TAIS) is a good tool that enables the management, assessment and monitoring of development processes in PNAs (protected natural areas), facilitating homogeneity and uniformity to aid comparison between protected areas in the centre-south of Spain, principally those areas designated as natural parks (NPs).  相似文献   
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Purpose  

The aim of this work was to investigate the possibility of using several bush and arboreal plant species, usually present as ornamental plants in street and parks, as environmental indicators of pollution. This is a research paper that evaluates the real possibility of using a fast and low-cost procedure to evaluate the pollution degree through data obtained from plant species growing within an urban environment.  相似文献   
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