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231.
This study aimed at the ecological-economic valuation of the Potengi estuary mangrove wetlands, based on the integration of spatial data (mangrove forest coverage map, Nautical Chart, Environmental Sensitivity Chart) with data from literature on the biogeochemistry of nitrogen (N), phosphorus (P), and heavy metals in the mangrove estuary wetland Potengi) and field verification data (topographic profile of mangrove forest, GPS routes obtained in the field in the touristy sightseeing areas and plots of mariculture). The ecological and economic valuation of the services performed by the Potengi estuary mangrove wetlands, mainly as biogeochemical barrier for the transport of P, N and heavy metals in tropical coastal areas, were obtained just as if the retention of those elements was necessary by Wastewater Treatment Plants (WTP) with Stabilization Ponds, typical in the estuary, and Zeolitic plant, respectively. Closer to real scenarios were observed for obtaining the values of these ecological services, such as the release of the P, N and heavy metals in domestic and industrial sewage in the estuary, the capability of dilution and the influence of the tides in the estuary. The tourism potential of the Potengi estuary mangrove wetlands were assessed according to the current forms of use, and potential of aquaculture through the main types of farming in mangrove areas. For these ecological services, considerable values were obtained of about USS15,500/ha, such as costs of implementation and construction of sewage treatment plants, as well as costs of sewage treatment plants. Nearly US$ 12.500 / ha amount each year from tourism and aquaculture income, demonstrating the economic viability of the Potengi estuary mangrove wetlands conservation.  相似文献   
232.
Industry is responsible for high water consumption and it has become one of the main sources of water resource deterioration. However, industries are seeking alternatives that minimize the impact of using these natural resources. Some of the alternatives for reducing water consumption involve the reuse and/or recycling of wastewater. This study aims to seek alternatives to optimize water networks, minimize freshwater consumption and/or reduce costs. A non-linear program (NLP) model targeting the minimization of freshwater consumption and/or operating costs was developed. The model is based on the conservation equations of chemical species (contaminants) and mass (water). Options to reduce the cost and consumption of networks with and without regeneration processes are presented. The solutions are identified using a two-step procedure in which cost is optimized while the previously obtained minimum freshwater consumption remains fixed. The results showed excellent agreement with results reported by other authors.  相似文献   
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Under the auspices of the World Meteorological Organization, there are a number of international initiatives to promote the development and use of so-called ensemble prediction systems (EPS) for flood forecasting. The campaign to apply these meteorological techniques to flood forecasting raises important questions about how the probabilistic information these systems provide can be used for what in operational terms is typically a binary decision of whether or not to issue a flood warning. To explore these issues, we report on the results of a series of focus group discussions conducted with operational flood forecasters from across Europe on behalf of the European Flood Alert System. Working in small groups to simulate operational conditions, forecasters engaged in a series of carefully designed forecasting exercises using various different combinations of actual data from real events. Focus group data was supplemented by a follow-up questionnaire survey exploring how flood forecasters understand risk, uncertainty, and error. Results suggest that flood forecasters may not instinctively use ensemble predictions in the way that promoters of EPS perhaps think they should. The paper concludes by exploring the implications of these divergent ‘epistemic cultures’ for efforts to apply ensemble prediction techniques developed in the context of weather forecasting to the rather different one of flood forecasting.  相似文献   
236.
ABSTRACT

Knowledge about phytoplankton communities is important for aquaculture due to their influence on environmental variables. The goal of the study was to evaluate the ecological effect of seaweed Gracilaria birdiae at three different densities: 2.5 (LG2.5); 5.0 (LG5.0) and 7.5?kg m?3 (LG7.5), on water quality variables and the phytoplankton communities in integrated aquaculture systems (shrimp and seaweed) with a control (without seaweed) (LB) using biofloc technology. Settleable and total suspended solids were significantly correlated with the phytoplankton groups. In addition, orthophosphate was the main variable controlling phytoplankton growth and gross primary production. No significant differences were identified among the treatments in terms of the phytoplankton assemblages (p?>?0.05) but differences were found between the communities (ANOSIM, R global?=?0.873) in relation to the days of the experiment. However, the LG2.5 treatment had higher diversity and lower species dominance, as well as higher productivity and final shrimp weight. The results indicate that seaweed inhibit phytoplankton growth, mainly of toxic species. They suggest that phytoplankton composition in integrated aquaculture systems in the presence of seaweed at a density of 2.5?kg m?3 is more diversified and provides better water quality and shrimp performance by inhibiting the abundance of harmful species.  相似文献   
237.
Heraclides brasiliensis (Lepidoptera: Papilionidae) larvae feed preferably on Piperaceae, foraging successfully on leaf tissues even though species of this contain high levels of secondary metabolites such as amides and lignans, associated with diverse biological activities including insecticidal properties. Studies examining the metabolism of chemical constituents in Piperaceae by insects are rare. In this study, we characterized the metabolites of 4-nerolidylcatechol (4-NC), the major constituent of Piper umbellata (Piperaceae), and E-2,3-dihydro-3-(3,4-dihydroxyphenyl)farnesoic acid, compounds from fecal material of H. brasiliensis larvae fed a diet containing only P. umbellata leaves. The biotransformed product was also detected in larval and pupal tissues. Moreover, we observed deactivation of the toxicity of P. umbellata leaves against brine shrimp after their metabolism in H. brasiliensis larvae from a LC50 of 523.3 to 3,460.7 μg/mL. This deactivation is closely associated with the biotransformation of 4-NC to E-2,3-dihydro-3-(3,4-dihydroxyphenyl)farnesoic acid, which showed LC50 of 8.0 and >1,000 μg/mL, respectively.  相似文献   
238.
Steady-state, dynamic, and spatial models were constructed for the benthic system of La Rinconada Marine Reserve off northern Chile (SE Pacific coast). We examined data on biomass, P/B ratios, catches, food spectrum, consumption, and the dynamics of commercial and non-commercial populations using three theoretical frameworks: Ecopath, Ecosim, and Ecospace. The biomass of the scallop Argopecten purpuratus and the clam Tagelus dombeii were the most relevant compartments of the studied ecosystem. Among the carnivores, the functional crab group Cancer spp. was the most relevant. The Rhodophyta was the dominant macroalga compartment of the system. The results obtained using mixed trophic impacts (MTI) showed that the predatory snail Thais chocolata propagated higher magnitudes of direct and indirect effects on the other species or functional groups. The sea star Luidia magallanica and Rhodophyta had the least effects on the remaining compartments. According to the Ecosim estimates (increasing mortality by fishing), the scallop A. purpuratus had the highest impact on the other compartments. The Ecospace model showed similar qualitative and quantitative effects for changes in biomass under three different exploitation scenarios (by subsystems and globally). Nevertheless, the greatest changes were provoked by using the top-down control and the vulnerabilities estimated by Ecosim. System recovery times were highest with increased mortality of the asteroid L. magallanica and the carnivorous snail T. chocolata, suggesting that the sea star could be considered to be a top predator with a top-down control. The FMSY estimated for the scallop A. purpuratus was close to the Fi originally entered in Ecopath, limiting the design and execution of an exploitation plan within ecologically sustainable boundaries. The situation was different (FMSY ? Fi) for the other commercial species, making possible multi-species exploitation programs. The Ecospace trophic-spatially explicit model shows a similar pattern of direct and indirect effects generated when exerting exploitation separately by subsystems. Therefore, habitat rotation of fisheries is not justified.  相似文献   
239.
The curculionid beetle Naupactus bipes (Germar, 1824) (Coleoptera: Curculionidae: Brachycerinae) has shown feeding preference for leaves of Piper gaudichaudianum, demonstrating an unexpected specificity for an insect considered to be a generalist. The leaves of P. gaudichaudianum contain the prenylated chromenes gaudichaudianic acid (4, major compound) and its methyl ester (5) in addition to a chromene (3) lacking one prenyl residue. In addition to 4, roots contain the chromone methyl ester (1) and methyl taboganate (2, major compound). Feeding on roots, larvae of N. bipes sequester exclusively the root-specific compounds 1 and 2. Adult beetles sequester the leaf-specific chromenes 3 and 4, but were found to also contain compounds 1 and 2 that are absent in leaves. Therefore, it is suggested that 1 and 2 are sequestered by larvae and can be found in the body of adult insects after long-term storage. In addition, 3 and 4, the major compounds in leaves were found to be associated with the eggs.  相似文献   
240.
The subject of sustainability reports, especially those related to GRI, has become an interesting topic to academics and practitioners. This paper seeks to propose an easy-to-use sustainability reporting assessment tool that is suitable to the GRI G4 guidelines. Our idea is to provide a tool that can be applied by an organization, based in GRI indicators, in a quick and easy way. The tool, called G-Index, represents the organizational sustainability performance. The index is a sum of four factors, and a questionnaire about the GRI elements raised the data to elaborate a Mudge diagram, which was used to define the weight values. Finally, the method for the evaluation tool was established, and a case study with the automotive sector was performed. The results showed us the G-Index represents a good option to assess the organization’s disclosure practices in sustainability reports based on the GRI framework. The report analysis presented some important facts, it is more common the disclosure of the Management Approach then the application of External Assurance. Furthermore, even the General Standard Disclosures of the GRI guidelines being mandatory, some companies do not fully disclose them, as shown in the GS factor, that makes up, the G-Index.  相似文献   
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