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21.
We mapped areas of congruence and conflict between the objectives of protecting red pandas ( Ailurus fulgens ) and meeting the claims and needs of people who live in and around Langtang National Park, Nepal. Semi-structured interviews were used to solicit information on land-use practices, and spatial information technology (sketch maps, satellite images, geographical information systems) was used to place these practices in a spatial context and to model the effects of grazing. Spatial information technology was useful for delineating areas where conflicts occur between the objectives of preserving biodiversity and meeting the needs of local residents. Despite the fact that villagers recognize pasture boundaries, rules and regulations govern pasture management, and sanctions are imposed on violators, over 60% of the red panda's habitat is heavily grazed, and all available land within the study site suitable for grazing is already being used. The study suggests that common property management of natural resources to protect biodiversity (i.e., red pandas) and meet the needs of local people at the same time will be difficult.  相似文献   
22.
The specific issue addressed in this paper is urban encroachment on agricultural lands, and the problems it poses for both analysis and the conservation of the land resource. The purpose of our discussion is two-fold: (1) to identify where and why traditional analytical and regulatory approaches fail to resolve land use conflicts, and (2) to explore ways and means of resolving some of the dilemmas which society faces in making land use decisions. This paper's contribution is in the spirit of Getting Incentives Right for the inter-temporal transfer of wealth, as represented in trade-offs between environmental and resource endowments and human and physical capital. Efforts are placed on identifying what the appropriate price, levy, taxes, and grant ratios ought to be in order to encourage individuals in the marketplace to act in society's interest. We have also explored ways of efficiently transmitting those incentives through the market mechanism, without unduly relying on bureaucratic methods or suasion. Emphasis is placed on mechanisms that have little scope for preferential access and are subject to public scrutiny; emphasis on such self-disciplining approaches should result in less effort expended on (unproductive) lobbying activities and bureaucratic administration.Brad Gilmour and Ted Huffman are Policy Analyst and Land Use Specialist respectively with Agriculture and Agri-food Canada. Andy Terauds and Charlie Jefferson are chairman and secretary respectively for the Ontario Institute of Agrologists Ottawa Branch Land Use Committee. This paper is intended to provoke thought and stimulate debate for input into the land use policy process and should not be seen as representing the views and policies of either Agriculture Canada or the Ontario Institute of Agrologists.  相似文献   
23.
Tadpoles show considerable behavioral plasticity. When population densities become high, tadpoles often become cannibalistic, likely in response to intense competition. Conspecific tissues are potentially an ideal diet by composition and should greatly improve growth and development. However, the potential release of alarm cues from the tissues of injured conspecifics may act to deter potential cannibals from feeding. We conducted multiple feeding experiments to test the relative effects that a diet of conspecifics has on tadpole growth and development. Results indicate that while conspecific tissues represent a better alternative to starvation and provide some benefits over low-protein diets, such a diet can have detrimental effects to tadpole growth and/or development relative to diets of similar protein content. Additionally, tadpoles raised individually appear to avoid consuming conspecific tissues and may continue to do so until they suffer from the effects of starvation. However, tadpoles readily fed upon conspecific tissues immediately when raised with competitors. These results suggest that cannibalism may occur as a result of competition rather than the specific quality of available diets, unless such diets lead to starvation.  相似文献   
24.
Environmental Science and Pollution Research - A new one-pot synthesis method optimized by a 23 experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate...  相似文献   
25.
Polybrominated diphenyl ethers (PBDEs) are one of the flame retardants widely used in plastics, textiles, electronic appliances, and electrical household appliances. In this study, PBDEs and organochlorine compounds (OCs) were determined in the archived samples from the Environmental Specimen Bank for Global Monitoring (es-BANK) at Ehime University. The blubber of cetaceans found stranded along the coasts of Japan, Hong Kong, the Philippines and India during the period from 1990 to 2001 were employed for chemical analysis to understand the present status of contamination and the specific accumulation of PBDEs. PBDEs were detected in all the cetacean samples analyzed, and concentrations were one or two orders of magnitude lower than for PCBs and DDTs. Concentrations of PBDEs ranged from a low value of 6.0 ng/g lipid wt. in spinner dolphin (Stenella longirostris) from India to a high value of 6000 ng/g lipid wt. in Indo-Pacific humpback dolphin (Sousa chinensis) from Hong Kong. No difference in PBDE levels between coastal and offshore species from Japan was observed, implying the existence of pollution sources in this region other than Japan. Highest concentrations of PBDEs were found in animals from Hong Kong, followed by Japan, and much lower levels from the Philippines and India, suggesting that developing nations may also have pollution sources of PBDEs. Geographical distribution of PBDEs in Asian waters was different from PCBs but similar to DDTs.  相似文献   
26.
Natural organic matter (NOM) is one of the main sources of environmental pollution to drinking water supplies in much of the UK and the US. Whilst traditional treatment with trivalent coagulants has proven a successful strategy in the past, operational problems are now being reported during periods of elevated organic levels in the water. Characterisation of the pollutants in terms of polarity, molecular weight and charge, provides a method to understand the impact of the observed temporal and spatial variations in terms of a mechanistic parameter relevant to the treatment processes. Results from this study demonstrate that it is not simply the increased organic concentration, but also the change in NOM composition and character, which influences the impact on the treatment processes. Consequently, monitoring of these parameters provides an insight into how to manage the impact caused by environmental changes to the catchments.  相似文献   
27.
Polybrominated diphenyl ethers (PBDEs) and organochlorine compounds (OCs) were determined in the blubber of male finless porpoises (Neophocaena phocaenoides) collected in 1990 and 2000/01 from the South China Sea. Among the organohalogen compounds analyzed, DDTs and PCBs were the predominant contaminants in the porpoises, ranging from 26,000 to 260,000 and 1400 to 28,000 ng/g lipid wt., respectively. PBDEs ranged from a minimum of 84 ng/g lipid wt., in 1990 to a maximum of 980 ng/g lipid wt., in 2001, showing a significant increase during the time period investigated. Congener profiles in finless porpoises did not shift to higher BDE congeners during these years, implying a continuous discharge of lower BDE commercial mixtures, such as PentaBDE. For OCs, HCHs concentrations decreased significantly, while others did not exhibit any significant temporal variation. Biomagnification factors (BMFs) were found to be highest for CHLs and lowest for HCB. PBDEs and PCBs had comparable BMFs, indicating a similar potential for biomagnification through the food web.  相似文献   
28.
Over the past half century, countries of Mainland Southeast Asia (MSEA) – Cambodia, Laos, Myanmar, Thailand, and Vietnam – have witnessed increases in commercialized agriculture with rapid expansions of boom-crop plantations. We used MODIS EVI and SWIR time-series from 2001–2014 to classify tree-cover changes across MSEA and performed a supervised change detection using an upscaling approach by deriving samples from existing Landsat classifications. We used the random forest classifier and distinguished 24 classes (16 representing boom-crops) with an accuracy of 82.2%. Boom-crops occupy about 18% of the landscape (8% of which is rubber). Since 2003 74,960 km2 of rubber have been planted; 70% of rubber is planted on former forest land, and 30% on low vegetation area (mainly former croplands). Timing, patterns of change, and deforestation rates, however, differ among the MSEA countries and the high spatial and temporal detail of our classification allowed us to quantify dynamics and discuss political and socio-economic drivers of change.  相似文献   
29.
This research has two interrelated objectives. The first is to determine the extent to which a relationship exists between farmer characteristics and farming practices in three villages in northern Thailand. The second is to use standard statistical methods for incorporating spatial variables into the analysis and to assess the effects of these variables on farmer decision making. The data base includes information on the location and size of villages, roads, streams, and fields; a digital elevation model with information on elevation, slope, and aspect; and information keyed to individual fields on crops and cropping methods and the ethnicity, income, and religion of farmers. The map data (517 plots) were entered into a computerized geographic information systems (GIS). Results suggest several hypotheses about the relationships between land use and owner characteristics. More significantly, the study concludes that spatial analysis appears to be most useful when the dependent variable is either continuous or ordinal. The outlook is not quite as optimistic when the dependent variable is a nonordinal categorical variable. Before spatial analysis can be applied regularly to social science data, better computational tools need to be developed.  相似文献   
30.

In this study, we evaluated, in a pioneering way, the influence of wavelengths from the decomposition of white light on the production and physicochemical properties of silver nanoparticles (AgNPs). Bearing in mind a process of green synthesis, an extract of the bracts of Bougainvillea glabra Choisy (BgC) was used, a species native to tropical and subtropical regions and frequently used in ornamentation, possessing in its photochemical composition, biomolecules capable of acting as reducing agents for convert Ag+ to Ag0. We used light-emitting diodes (LED) to obtain the desired wavelengths (violet, blue, green, yellow, orange, and red) in the test called rainbow, and we evaluated the obtaining of AgNPs compared to white LED light, nature, and absence of light. In the rainbow assay, we obtained a gradual increase in the intensity of the plasmonic band resonance from the red wavelength (0.124 ± 0.067 a.u.) to violet (0.680 ± 0.199 a.u.), indicating a higher reaction yield in obtaining AgNPs. Smaller hydrodynamic sizes (approximately 150 nm) at more energetic wavelengths (violet, blue, and green) about less energetic wavelengths (yellow, orange, and red) (approximately 400 nm) were obtained. Analysis by SEM microscopy, FTIR spectroscopy, and X-ray diffraction indicates the presence of silver nanoparticles in all LED colors used together with white LED light and Laboratory light (natural light). Due to the high environmental demand to remove pollutants from water sources, including textile dyes, we applied AgNPs/BgC to remove methylene blue (MB) dye from an aqueous solution. A minimum removal percentage greater than 65%, with emphasis on formulations synthesized by the colors of violet LED (84.27 ± 2.65%) and orange LED (85.91 ± 1.95%), was obtained.

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