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181.
Van Boeckel TP Prosser D Franceschini G Biradar C Wint W Robinson T Gilbert M 《Agriculture, ecosystems & environment》2011,141(3-4):373-380
Domestic ducks are considered to be an important reservoir of highly pathogenic avian influenza (HPAI), as shown by a number of geospatial studies in which they have been identified as a significant risk factor associated with disease presence. Despite their importance in HPAI epidemiology, their large-scale distribution in monsoon Asia is poorly understood. In this study, we created a spatial database of domestic duck census data in Asia and used it to train statistical distribution models for domestic duck distributions at a spatial resolution of 1 km. The method was based on a modelling framework used by the Food and Agriculture Organisation to produce the Gridded Livestock of the World (GLW) database, and relies on stratified regression models between domestic duck densities and a set of agro-ecological explanatory variables. We evaluated different ways of stratifying the analysis and of combining the prediction to optimize the goodness of fit of the predictions. We found that domestic duck density could be predicted with reasonable accuracy (mean RMSE and correlation coefficient between log-transformed observed and predicted densities being 0.58 and 0.80, respectively), using a stratification based on livestock production systems. We tested the use of artificially degraded data on duck distributions in Thailand and Vietnam as training data, and compared the modelled outputs with the original high-resolution data. This showed, for these two countries at least, that these approaches could be used to accurately disaggregate provincial level (administrative level 1) statistical data to provide high resolution model distributions. 相似文献
182.
Effect of water regimes and organic matters on transport of arsenic in summer rice (Oryza sativa L.) 总被引:1,自引:1,他引:0
The arsenic contamination in soil-water-plant systems is a major concern of where, the groundwater is being contaminated with
arsenic (above 0.01 mg/L) in the Indian subcontinent. The study was conducted with organic matter to find out the reducing e ect on
arsenic load to rice (cv. Khitish). It was observed that intermittent ponding reduced arsenic uptake (23.33% in root, 13.84% in shoot and
19.84% in leaf) at panicle initiation stage, instead of continuous ponding. A decreasing trend of arsenic accumulation (root > straw >
husk > whole grain > milled grain) was observed in di erent plant parts at harvest. Combined applications of lathyrus + vermicompost
+ poultry manure reduced arsenic transport in plant parts (root, straw, husk, whole grains and milled grain) which was significantly at
par (p > 0.05) with chopped rice straw (5 tons/ha ) + lathyrus green manuring (5 tons/ha) in comparison to control and corresponding
soils. A significant negative correlation of arsenic with phosphorus (grain P with arsenic in di erent parts R2= 0.627–0.726 at p >
0.01) was observed. Similarly, soil arsenic had a negative correlation with soil available phosphorus (R2 = 0.822 at p > 0.001) followed
by soil nitrogen (R2= 0.762 at p > 0.01) and soil potassium (R2 = 0.626 at p > 0.01). Hence, e ective management of contaminated
irrigation water along with organic matter could reduce the arsenic build up to plants and soil. 相似文献
183.
Ningombam Linthoingambi Devi Shihua Qi Paromita Chakraborty Gan Zhang Ishwar Chandra Yadav 《环境科学学报(英文版)》2011,23(5):808-815
Thirty-six polyurethane foam disk passive air samplers (PUF-PAS) were deployed over a year during January to December, 2009
at three locations, i.e., Imphal (urban site), Thoubal (rural site) and Waithou (alpine site) of Manipur, to assess the seasonal local
atmospheric emission of selected organochlorine pesticides (OCPs). The average concentration of HCHs monitored at mountain site
during hot season (Mar, Apr, and May) and rainy seasons (Jun, Jul, Aug, and Sep) were 403 and 349 pg/m3, respectively. DDTs had a
high concentration with 384 pg/m3 at rural site and 379 pg/m3 at urban site during hot seasons. Endosulfans and chlordane were found
high in concentration during hot seasons (260 pg/m3) and low during retreating monsoon seasons (44 pg/m3) at rural site. Most of the
OCPs concentrations were high during cultivation period. The OCP concentrations of rainy season were highly correlated (p < 0.01)
with OCPs of hot seasons. Further, positive correlation (p < 0.05) was also obtained between cold seasons and retreating monsoon.
Principal component analysis showed a significant correlation among the four seasons and distribution pattern of OCPs in air. Back
trajectory analysis by using HYPSLIT model showed a long range air transport of OCPs to the present study area. Present OCP levels
at Manipur is an outcome of both local emission and also movement of air mass by long range atmospheric transport. 相似文献
184.
M Jake Vander Zanden Lucas N Joppa Brant C Allen Sudeep Chandra David Gilroy Zeb Hogan Jeffrey T Maxted Jun Zhu 《Ecological applications》2007,17(8):2281-2289
The ecological impacts of recreational fisheries are of growing concern and pose a number of unique management challenges. Here we report on our efforts to provide guidance for managing a recreational fishery for taimen, the giant Eurasian trout (Hucho taimen) in Mongolia. This species has declined dramatically across its range of Siberia and Central Asia, and is currently listed as endangered in Mongolia. Strong populations persist in remote regions of Mongolia because of limited anthropogenic impacts and harvest, though interest in the fishery is expanding rapidly. Current fishing regulations list the spring "opening date" for taimen fishing as 15 June, although regulations have not been consistently enforced, partially because taimen spawn much earlier than 15 June in much of the country. Through a combination of statistical models, climate data, knowledge of taimen biology, and geographic information systems (GIS), we model taimen spawning dates for potential habitat in Mongolia. A parametric bootstrap procedure was used to simulate variability in spawning date derived from inter-annual climate variability and model error, from which we estimated the date in which taimen spawning is predicted to occur with 90% confidence. We recommend the designation of three fisheries management zones, with corresponding opening dates of 20 May, 1 June, and 15 June. Our fishery opening date recommendations are less restrictive than existing regulations. Provided there is little or no catch-and-release fishing mortality, this approach serves both environmental and human needs by protecting taimen during the reproductive period, while still allowing a post-spawning catch-and-release fishery that benefits local economies and generates revenue (through fishing concession fees) for local conservation efforts. 相似文献
185.
Yar tsa Gumba, the local name for Cordyceps sinensis, is an entomophilus fungus in the order Hypocreales and family Scolecosporaceae, found primarily in alpine and subalpine regions, from 3200 to 4000 m asl. The fungus is parasitic on caterpillars, primarily those in the genus Hepialus. Studies on Cordyceps sinensis indicate that the fungus may improve liver function, reduce cholesterol, adjust protein metabolism, inhibit lung carcinoma and treat aging disorders. In the last five years, since it was found in parts of Garhwal and Kumaun Himalaya, massive exploitation has occurred, leading to a drastic decrease in wild populations. This paper presents results of an exploration carried out on the fungus at several important sites, the mode of trafficking and suggested policy initiative for its sustainable exploitation. 相似文献
186.
Sorption of cadmium and zinc from aqueous solutions by zeolite 4A, zeolite 13X and bentonite 总被引:3,自引:0,他引:3
Purna Chandra Rao G Satyaveni S Ramesh A Seshaiah K Murthy KS Choudary NV 《Journal of environmental management》2006,81(3):265-272
The sorption and desorption of cadmium and zinc on zeolite 4A, zeolite 13X and bentonite has been studied using batch sorption studies. Parameters such as equilibrium time, effect of pH and sorbent dose were studied. The sorbents exhibited good sorption potential for cadmium and zinc with a peak value at pH 6.0 and 6.5, respectively. The sorption followed the Freundlich sorption model. More than 70% sorption occurred within 20 min and equilibrium was attained at around 90 min for the three sorbents. The metals sorption by zeolite 4A was higher than that by zeolite 13X and bentonite. The desorption studies were carried out using NaCl solution and the effect of NaCl concentration on desorption was also studied. Maximum desorption of 76% for cadmium and 80% for zinc occurred with 10% NaCl. 相似文献
187.
Leachate Characterization and Assessment of Groundwater Pollution Near Municipal Solid Waste Landfill Site 总被引:6,自引:0,他引:6
Leachate and groundwater samples were collected from Gazipur landfill-site and its adjacent area to study the possible impact
of leachate percolation on groundwater quality. Concentration of various physico-chemical parameters including heavy metal
(Cd, Cr, Cu, Fe, Ni, Pb and Zn) and microbiological parameters (total coliform (TC) and faecal coliform (FC)) were determined
in groundwater and leachate samples. The moderately high concentrations of Cl−, NO−
3, SO2−
4, NH+
4, Phenol, Fe, Zn and COD in groundwater, likely indicate that groundwater quality is being significantly affected by leachate
percolation. Further they proved to be as tracers for groundwater contamination. The effect of depth and distance of the well
from the pollution source was also investigated. The presence of TC and FC in groundwater warns for the groundwater quality
and thus renders the associated aquifer unreliable for domestic water supply and other uses. Although some remedial measures
are suggested to reduce further groundwater contamination via leachate percolation, the present study demand for the proper
management of waste in Delhi. 相似文献
188.
Ross Westoby Rachel Clissold Karen E. McNamara Anita Latai-Niusulu Alvin Chandra 《Ambio》2022,51(5):1239
Human society has experienced, and will continue to experience, extensive loss and damage from worsening anthropogenic climate change. Despite our natural tendencies to categorise and organise, it can be unhelpful to delineate clean boundaries and linear understandings for complex and messy concepts such as loss and damage. Drawing on the perspectives of 42 local and regional Pacific Islander stakeholders, an underexplored resource for understanding loss and damage, we explore the complexity and interconnectedness of non-economic loss and damage (NELD). According to participants, Pacific Islander worldviews, knowledge systems and cosmologies often make it difficult to separate and evaluate NELD independently, challenging the nomenclature of NELD categories developed through international mechanisms. Instead, NELD understandings are often centred on the interdependencies between losses, including the cascading flow-on effects that can occur and the nature of some losses as risk multipliers (i.e. one loss creating the risk for further losses). Most notably, losses to biodiversity, ecosystem services and land are critically linked to, and have cascading effects on, livelihoods, knowledge, ways of life, wellbeing, and culture and heritage. We argue that loss and damage is not always absolute, and that there are NELD that are arguably reparable. Concerning, however, is that biodiversity loss, as a risk multiplier, was considered the least reparable by participants. We put forward that NELD understandings must consider interconnectivity, and that biodiversity and ecosystem conservation and restoration must be the focus for interventions to prevent irreparable and cascading losses from climate change in the Pacific Islands. 相似文献
189.
Eco-sanitation and its benefits: an experimental demonstration program to raise awareness in central Nepal 总被引:1,自引:0,他引:1
Surendra K. Pradhan Ram Chandra Piya Helvi Heinonen-Tanski 《Environment, Development and Sustainability》2011,13(3):507-518
This study focuses on awareness and an experimental demonstration about the use of human urine and wood ash as a fertilizer.
This study was conducted in Chanauta, central Nepal, from November 2009 to February 2010. The villagers (N = 27) were asked about their awareness of eco-sanitation and fertilizer value of urine and ash. All the participants agreed
that the use of urine and ash was a good idea. In the experimental study, the fertilizer value of urine+ash was compared with
animal manure and no-fertilizer in the cultivation of radish, potato, broadleaf mustard, cauliflower, and cabbage. Different
plants cultivated plots received 54–81 kgN/ha with urine+ash or manure fertilizer. The urine+ash fertilizer produced significantly
(p < 0.05) higher broadleaf mustard biomass than obtained from animal manure and without fertilization. Urine+ash-fertilized
plots growing radish, potato, cauliflower, and cabbage produced similar or slightly higher yields biomass compared to those
achieved with manure fertilization. This might be because of high P, K as well as greater availability of N in applied urine
compared to manure. It is concluded that urine+ash fertilizer can be used instead of animal manure; in this study, a dose
of 4 L of urine was equal to 1 kg of dry cattle manure and produced a similar or greater yield of vegetable biomass than manure
fertilization. To be able to generalize this conclusion, it is important to conduct these kinds of experiments with different
seasonal crops and in other parts of the world. 相似文献
190.
Endalkachew Sahle-Demessie Catherine B. Almquist Sridara Chandra Sehker 《Water, Air, & Soil Pollution: Focus》2008,8(3-4):297-309
Oxidation of methanol over V2O5 catalysts supported on anatase TiO2 that were prepared using sol-gel formation and impregnation procedures were investigated. The effects of incorporating Mg
in sol-gel to influence the properties of the catalyst were also studied. The process provides an alternative low temperature
reaction pathway for reducing emissions of hazardous air pollutant (HAPs) such as methanol and total reduced sulfur compounds
(TRS) from pulp and paper mills. The bulk and surface composition of the catalysts were determined by XRD and SEM-EDAX, respectively.
The X-ray diffraction patterns of the vanadia–titania catalysts showed mainly the anatase phase of TiO2. Temperature programmed desorption of methanol from the different catalyst showed that the α and β peaks differ significantly
with V content and addition of Mg. The combination of gas phase and surface reactions on the V/TiO2 catalysts reduced the amount of ozone required for high degradation of methanol to mainly CO
x
with small quantities of methyl formate. In the absence of ozone the catalysts showed very low activity. It is hypothesized
that the ozone is directly influencing the V4+ and V5+ redox cycle of the catalyst. Oxidation of methanol is influenced by the operation variables and catalyst properties. The
results of this study revealed that the V content has significant influence on the catalyst activity, and the optimum vanadia
loading of about 6 wt%. Higher turnover frequencies were observed over sol-gel catalysts than with catalysts prepared by the
impregnation method. 相似文献