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901.
This paper considers the principal elements that underpin policy frameworks for supporting food security in protracted crisis contexts. It argues that maintaining the food entitlements of crisis-affected populations must extend beyond interventions to ensure immediate human survival. A 'policy gap' exists in that capacities for formulating policy responses to tackle the different dimensions of food insecurity in complex, fluid crisis situations tend to be weak. As a result, standardised, short-term intervention designs are created that fall short of meeting the priority needs of affected populations in the short and long term and only partially exploit the range of policy options available. The paper discusses key attributes of agency frameworks that could support more effective policy processes to address longer term as well as immediate food security needs. Additionally, it points to some main challenges likely to be encountered in developing such frameworks and, with the participation of beneficiaries, translating them into effective action. 相似文献
902.
The dugong is classified as vulnerable to extinction by the World Conservation Union on the basis of declines in area or extent
of occupancy, habitat quality, and actual or potential levels of exploitation. In Thailand, the largest groups of dugongs
are found near islands off the Andaman coast. The authors conducted a 2-year project that included dugong population and habitat
assessment as well as interviews with local fishers. The results indicate declining populations of dugongs. The largest threat
to dugongs is incidental catch in fishing nets. The numbers of deaths reported place the dugong population along the Andaman
Sea in danger of extirpation. Other threats include seagrass destruction both from fishing and coastal development and the
use of dugong parts for medicinal purposes. Villagers still show strong ties with dugongs, and the majority favor establishing
more large protected areas for the species. These should arise from an integrated national dugong and seagrass conservation
strategy formulated by concerned stakeholders from government, nongovernmental organizations, scientists, and local communities.
The strategy needs to be both top down and bottom up in its formation to balance existing and potential uses as well as conflicts
between artisanal and commercial fishers. The strategy should include the development of educational materials and enforceable
regulations, as well as the designation of community-protected seagrass beds and a system of dugong sanctuaries along the
Andaman coast. An integrated management plan is needed urgently, with the continued input of concerned scientists, to monitor
and increase knowledge of dugong behavior and distribution. 相似文献
903.
Impact of land use on soluble organic nitrogen in soil 总被引:1,自引:0,他引:1
Victoria B. Willett James J. Green Andrew J. MacDonald John A. Baddeley Georg Cadisch Steven M. J. Francis Keith W. T. Goulding Gary Saunders Elizabeth A. Stockdale Christine A. Watson David L. Jones 《Water, Air, & Soil Pollution: Focus》2005,4(6):53-60
Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO? 3, NH+ 4) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention. 相似文献
904.
Lucie Laurian Michael Backhurst Philip Berke Neil Ericksen Jan Crawford 《Journal of Environmental Planning and Management》2004,47(4):555-577
This article investigates the determinants of plan implementation by applying a recently‐developed Plan Implementation Evaluation methodology. The lack of methodology to assess the implementation of plans has so far precluded any systematic analysis of the determinants of the implementation of local environmental plans. The article focuses on the implementation of plans in New Zealand. The key factors of implementation are: the quality of the plan; the capacity and commitment of land developers to implement plans; the capacity and commitment of the staff and leadership of planning agencies to implement plans; and the interactions between developers and the agency. The analysis is based on 353 permits implementing six local environmental plans in New Zealand, and on surveys of the developers who obtained the permits and of the planning agencies that granted the permits. The analysis finds that plan implementation is mainly driven by the resources of the planning agencies and by the quality of the plans, rather than by the characteristics of developers. Investments in plan writing and agency and staff capacity building thus improve the implementation of plans in the long‐run. 相似文献
905.
906.
The link between livestock production, manure management, and human health has received much public attention in recent years. Composting is often promoted as a means of sanitizing manure to ensure that pathogenic bacteria are not spread to a wider environment during land application. In a two-year study (1998 and 1999) in southern Alberta, we examined the fate of coliform bacteria during windrow composting of cattle (Bos taurus) manure from feedlot pens bedded with cereal straw or wood chips. Numbers of total coliforms (TC) and Escherichia coli declined as the composting period progressed. In 1998, TC levels (mean of both bedding types) were log10 7.86 cells g(-1) dry wt. for raw manure on Day 0, log10 3.38 cells g(-1) by Day 7, and log10 1.69 cells g(-1) by Day 14. More than 99.9% of TC and E. coli was eliminated in the first 7 d when average windrow temperatures ranged from 33.5 to 41.5 degrees C. The type of bedding did not influence the numbers of TC or E. coli. Dessication probably played a minor role in coliform elimination, since water loss was low (< 0.07 kg kg(-1)) in the first 7 d of composting. However, total aerobic heterotroph populations remained high (> 7.0 log10 CFU g(-1) dry wt., where CFU is colony forming units) throughout the composting period, possibly causing an antagonistic effect. Land application of compost, with its nondetectable levels of E. coli compared with raw manure, should minimize environmental risk in areas of intensive livestock production. 相似文献
907.
Miller JJ Beasley BW Yanke LJ Larney FJ McAllister TA Olson BM Selinger LB Chanasyk DS Hasselback P 《Journal of environmental quality》2003,32(5):1887-1894
Nutrients, soluble salts, and pathogenic bacteria in feedlot-pen manure have the potential to cause pollution of the environment. A three-year study (1998-2000) was conducted at a beef cattle (Bos taurus) feedlot in southern Alberta, Canada to determine the effect of bedding material [barley (Hordeum vulgare L.) straw versus wood chips] and season on the chemical and bacterial properties of pen-floor manure. Manure was sampled for chemical content (N, P, soluble salts, electrical conductivity, and pH) and populations of four groups of bacteria (Escherichia coli, total coliforms, and total aerobic heterotrophs at 27 and 39 degrees C). More chemical parameters of manure were significantly (P < or = 0.05) affected by season (SO4, Na, Mg, K, Ca, sodium adsorption ratio [SAR], total C, NO3-N, NH4-N, total P, and available P) than by bedding (K, pH, total C, C to N ratio, NH4-N, and available P). Bedding had no significant (P > 0.05) effect on the four bacterial groups whereas season affected all four groups. Numbers of E. coli and total coliforms (TC) were significantly higher by 1.72 to 2.02 log10 units in the summer than the other three seasons, which was consistent with a strong positive correlation of E. coli and TC with air temperature. The low ratio of bedding to manure in the pens was probably the major cause of the lack of significant bedding effects. Bedding material and seasonal timing of cleaning feedlot pens and land application of manure may be a potential tool to manage nutrients, soluble salts, and pathogens in manure. 相似文献
908.
T. Taylor Eighmy Bradley S. Crannell James E. Krzanowski Leslie G. Butler Frank K. Cartledge Earl F. Emery J. Dykstra Eusden Jr Elisabeth L. Shaw Carl A. Francis 《Waste management (New York, N.Y.)》1998,18(6-8)
The use of soluble PO43− as a heavy metal chemical stabilization agent was evaluated for a dust generated from melting or vitrification of municipal solid waste combustion residues. Vitrification dusts contain high concentrations of volatile elements such as Cl, Na, K, S, Pb, and Zn. These elements are present in the dusts largely as simple salts (e.g. PbCl2, ZnSO4) which are highly leachable. At an experimental dose of 0.4 moles of soluble PO43− per kg of residue, the pH-dependent leaching (pH 5,7,9) showed that the treatment was able to reduce equilibrium concentrations by factors of 3 to 100 for many metals; particularly Cd, Cu, Pb and Zn. Bulk and surface spectroscopies showed that the insoluble reaction products are tertiary metal phosphate [e.g. Zn3(PO4)2] and apatite [e.g. Pb5(PO4)3Cl] family minerals. Geochemical thermodynamic equilibrium modeling showed that apatite family and tertiary metal phosphate phases act as controlling solids for the equilibrium concentrations of Ca2+, Zn2+, Pb2+, Cu2+, and Cd2+ in the leachates during pH-dependent leaching. Both end members and ideal solid solutions were seen to be controlling solids. Soluble phosphate effectively converted soluble metal salts into insoluble metal phosphate phases despite the relatively low doses and dry mixing conditions that were used. Soluble phosphate is an effective stabilization agent for divalent heavy metals in melting dusts where leachable metals are present in high concentrations. 相似文献
909.
910.
Karin Sundberg MD Steen Smidt-Jensen Claes Lundsteen Kirsten Agerbæk John Philip 《黑龙江环境通报》1993,13(12):1101-1110
Due to the low cell concentration, cultures from early amniotic fluid specimens usually require 2–3 weeks in culture prior to karyotyping. The purpose of this study was to evaluate the culture quality of amniotic fluid cells from early pregnancy, obtained by a new filter technique. The hypothetical advantage of the technique was that the increased cell yield might reduce the culture time before karyotyping. Culture quality was assessed by the number of colonies, the percentage of colonies containing mitoses in filter and control cultures, and the culture time. The setting was a consecutive clinical trial. One hundred samples were obtained from ongoing pregnancies at 11–14 weeks of gestation (mean 12·8 weeks). By circulating a mean of 26 ml of amniotic fluid through a cell filter system leading the cell-free fluid back to the amniotic cavity, the cell yield was increased in the sample of 7 ml corresponding to the dead space of the filter system. The culture results were compared with control cultures from 5 ml samples drawn from the same pregnancies prior to recirculation. The cultures from the first flushing of the filter system yielded 2·6 times more colonies and in total 4·2 times more colonies were found in the three cultures grown from each filter sample when compared with the control cultures. Moreover, the filter cultures showed significantly more colonies with mitoses. The mean culture time was 8·0 days for the filter cultures, from which the karyotypes were analysed. The controls would have needed more time in culture to fulfil the diagnostic criteria for karyotyping. One case of 47,XY, + 21 was found; the rest had normal karyotypes. We conclude that the filter technique improves the culture quality of early amniotic fluid samples and allows early arrest of the cultures. 相似文献