A regional experiment in co-management is underway in the Lower Amazon that is developing the basic policy and institutional
elements for an ecosystem-based approach to floodplain management. This initiative grew out of the grassroots movement of
floodplain communities who, concerned with excessive commercial fishing pressure on local fisheries, took control of local
lakes and implemented collective agreements regulating fishing activity. This paper describes the main elements of the evolving
regional management system. This process has focused on four main dimensions of floodplain settlement and resource use: development
of sustainable management systems for floodplain resources, policies and institutions for fisheries co-management, collective
agreements for grazing cattle on floodplain grasslands, and a land tenure policy consistent with the objectives of the evolving
co-management system. Over the last year INCRA, the National Institute for Colonization and Agrarian Reform, has begun implementation
of a comprehensive new land tenure policy that could resolve structural deficiencies in the existing co-management system
and provide the basis for the ecosystem-based management of the Lower Amazon floodplain.
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
The capability of Scirpus maritimus and of Juncus maritimus to accumulate metals and the role of each plant on the physico-chemical composition of sediments, from Douro river estuary (NW Portugal), were investigated through a year of plants' life. The contents of Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were determined (by atomic absorption spectrophotometry) in sediment, rhizosediments (those in contact with each plant roots and rhizomes) and different tissues of S. maritimus and of J. maritimus. Both plants influenced the sediment composition (concentrating metals around its roots) and were able to bioaccumulate Cd, in spite of some seasonal variations in the metal levels in the system (both in rhizosediments and plants' roots). Therefore, both plants showed to have potential for Cd phytostabilization. S. maritimus could also concentrate Pb in its roots, probably by sorption on the root surface in (hydr)oxide forms, therefore, denoting capability for Pb phytostabilization. 相似文献
Activated carbons were prepared from flamboyant pods by NaOH activation at three different NaOH:char ratios: 1:1 (AC-1), 2:1 (AC-2), and 3:1 (AC-3). The properties of these carbons, including BET surface area, pore volume, pore size distribution, and pore diameter, were characterized from N2 adsorption isotherms. The activated carbons obtained were essentially microporous and had BET surface area ranging from 303 to 2463 m2 g−1.13C (CP/MAS and MAS) solid-state NMR shows that the lignocellulosic structures were completely transformed into a polycyclic material after activation process, thermogravimetry shows a high thermal resistance, Boehm titration and Fourier-transform infrared spectroscopy allowed characterizing the presence of functional groups on the surface of activated carbons. Scanning electron microscopy images showed a high pore development. The experimental results indicated the potential use of flamboyant pods as a precursor material in the preparation of activated carbon. 相似文献
Analysis of indoor air quality (IAQ) in schools usually reveals higher levels of pollutants than in outdoor environments.
The aims of this study are to measure indoor and outdoor concentrations of NO2, speciated volatile organic compounds (VOCs) and carbonyls at 14 elementary schools in Lisbon, Portugal. The investigation
was carried out in May–June 2009. Three of the schools were selected to also measure comfort parameters, such as temperature
and relative humidity, carbon dioxide (CO2), carbon monoxide (CO), total VOCs, and bacterial and fungal colony-forming units per cubic metre. Indoor concentrations
of CO2 in the three main schools indicated inadequate classroom air exchange rates. The indoor/outdoor (I/O) NO2 ratio ranged between 0.36 and 0.95. At the three main schools, the total bacterial and fungal colony-forming units (CFU)
in both indoor and outdoor air were above the advised maximum value of 500 CFU/m3 defined by Portuguese legislation. The aromatic compounds benzene, toluene, ethylbenzene and xylenes, followed by ethers,
alcohols and terpenes, were usually the most abundant classes of VOCs. In general, the indoor total VOC concentrations were
markedly higher than those observed outdoors. At all locations, indoor aldehyde levels were higher than those observed outdoors,
particularly for formaldehyde. The inadequate ventilation observed likely favours accumulation of pollutants with additional
indoor sources. 相似文献
Diverse genetic biomarkers have been used to evaluate the effects of pollution by mutagenic agents such as metals and pesticides, as well as a large variety of chemical substances derived from human activities. This work researched the effects that an exposure of 60 days to the insecticide Fipronil (concentrations of 0.05, 0.10 and 0.23 μg/L) can cause in the fish Rhamdia quelen using Comet assay with gills, histopathological analysis of gills and the Piscine Micronucleus test and Nuclear Morphological Alterations. The results for the Comet assay and for gills histopathological injuries showed no difference between the control group and the contaminated groups. In the Piscine Micronucleus test, the smallest concentration of Fipronil (0.05 μg/L) was similar as the control group, while concentrations of 0.10 and 0.23 μg/L caused more damage to the DNA. These results suggested that only the highest concentrations of Fipronil tested cause damage in erythrocytes, but none of these concentrations was sufficient to alter the DNA in the gill cells. R. quelen may be a less sensitive bioindicator than other fish that have been tested. On the other hand, the concentrations used may not have been sufficient to detect alterations in the DNA of R. quelen with the chosen tests. Works like this take on great importance given the enormous quantity of substances that are thrown daily into the environment in an uncontrolled way, without evaluation of the consequences. The application of these tests with other concentrations, tissues and exposure times is suggested for future works. 相似文献
The problem of leakage is complex and requires actions drawn from different aspects of water network management. Inadequate maintenance has serious consequences, both financial and environmental. This paper proposes a group decision-making model based on PROMETHEE V method to aim a leakage management strategy, which takes into account the points of view of four stakeholders, selecting feasible options, and considering the available budget as constraint. Thus, this strategy is the combination of options that will efficiently meet technical, socio-economic and environmental criteria to achieve sustainable development. 相似文献
Food and Environmental Virology - Human noroviruses (hNoV) are the primary cause of foodborne disease in the USA. Most studies on inactivation kinetics of hNoV and its surrogates are performed in... 相似文献
Mercury is an important pollutant, released into aquatic ecosystems both naturally and by anthropogenic action. This element is transferred to aquatic organisms in different ways, causing potential health risks. In addition, mercury can be accumulated by humans, especially through the consumption of contaminated food. This systematic review aims to present mercury pathways, the major routes through which this element reaches the aquatic environment and its transformations until becoming available to living animals, leading to bioaccumulation and biomagnification phenomena. The key biotic and abiotic factors affecting such processes, the impact of mercury on animal and human health and the issue of seafood consumption as a source of chronic mercury contamination are also addressed. A total of 101 articles were retrieved from a standardized search on three databases (PubMed, Emabse, and Web of Science), in addition to 28 other studies not found on these databases but considered fundamental to this review (totaling 129 articles). Both biotic and abiotic factors display fundamental importance in mediating mercurial dynamics, i.e., muscle tropism, and salinity, respectively. Consequently, mercurial contamination in aquatic environments affects animal health, especially the risk of extinction species and also on human health, with methylmercury the main mercury species responsible for acute and chronic symptomatology. 相似文献
The study addresses in vitro degradation potential of airborne Aspergillus and Penicillium/Talarmyces species originating from cultural heritage conservation premises. A series of rapid, cost effective biodegradation assays were performed to assess production of extracellular pigments, acids, and enzymes. Most of the isolates have demonstrated positive growth in at least one of the preformed tests. Strongest overall degradation potential was demonstrated for Penicillium brevicompactum, P. glabrum, and Talaromyces sayulitensis while Aspergillus domesticus, A. penicillioides, A. pseudoglaucus, and A. ruber did not exhibit positive reaction in any of the employed assays. Majority of isolates exhibited proteolytic and cellulolytic activity while carbonate dissolution was observed for only five tested fungi. Highest alteration of pH value in liquid media was documented for T. sayulitensis while A. niger and P. expansum exhibited strongest acid production on CREA. Certain isolates, mostly Penicillium species, displayed production of extracellular pigments. The results imply that many of the tested fungi have significant biodegradation capacity, indicating their potential to inflict structural and esthetic alterations on cultural heritage objects.
Environment, Development and Sustainability - The use of low efficient cookstoves has several severe negative impacts. Burning solid fuels kills about 4 million people every year, a number which is... 相似文献