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41.
The article presents household vulnerability, local community adaptive capacity, and government’s response to tidal flood hazard in the Semarang coastal area, Central Java Province, Indonesia. Using data gathered from a survey of households, the study revealed a number of important factors about the interaction between people and flood. The coastal community has been experiencing problems related to tidal floods. They have adapted to tidal flooding with structural measures, such as increasing the floor level, making small dams in front of houses, increasing yard and street levels in the neighborhood area, and creating dykes around residential areas. Tidal flood mitigation in the Semarang coastal area should incorporate governmental action and local community capacities for proper protection of the population.  相似文献   
42.
Humic substances, in aqueous bodies primarily fulvic acids, may demonstrate an inhibitory as well as an activating influence on organisms. We present evidence with bacteria-containing algal cultures and with cultures of the nematodeCaenorhabditis elegans. Structural elements of the fulvic acids which may be responsible for such effects are not yet known. Furthermore, the presence of fulvic acids may lead to increases in bioconcentration of xenobiotics. Increase in the toxicity of xenobiotics in the presence of humic substances have also been described. We present studies applying lethal as well as sublethal toxicity endpoints.  相似文献   
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甲苯二异氰酸酯(TDI)致癌性的综合评估   总被引:1,自引:0,他引:1  
甲苯二异氰酸酯(TDI)被数家机构分类为可能的人类致癌物,其主要依据为动物实验发现对啮齿动物经灌胃暴露TDI后肿瘤发生率升高。基于研究结果的可靠性以及一致性,综合评估了现有研究数据是否支持这一分类。结果显示现有的流行病学数据不足以有力证明TDI为人类致癌物。动物实验研究表明,吸入接触TDI并不导致肿瘤发生。经灌胃暴露后观察到的肿瘤很可能是由于TDI转化为已知的啮齿动物致癌物甲苯二胺(TDA)所致。在TDI吸入暴露的体内实验中,当由TDI转化生成的TDA不能达到具有显著生物学效应的浓度时,TDI对啮齿动物或人类都没有遗传毒性。由于哺乳动物在生理性接触条件下TDI不能转变成TDA,所以对人类而言,TDI接触与致癌效应之间无直接的显著因果关系。因此虽然在如灌胃等非生理暴露的条件下,TDI可能的人类致癌物的分类是正确的,但本文对其致癌研究数据的合理评估和正确理解有助于将产品监管力度集中于与职业暴露更相关的有害健康效应上。  相似文献   
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Condensed tannins can be found in various parts of many plants. Unlike lignin there has been little study of their fate as they enter the soil organic matter pool and their influence on nutrient cycling, especially through their protein-binding properties. We extracted and characterized tannin-rich fractions from humus collected in 1998 from a black spruce [Picea mariana (Mill.) Britton et al.] forest in Canada where a previous study (1995) showed high levels (3.8% by weight) of condensed tannins. A reference tannin purified from black spruce needles was characterized by solution 13C nuclear magnetic resonance (NMR) as a pure procyanidin with mainly cis stereochemistry and an average chain length of four to five units. The colorimetric proanthocyanidin (PA) assay, standardized against the black spruce tannin, showed that both extracted humus fractions had higher tannin contents than the original humus (2.84% and 11.17% vs. 0.08%), and accounted for 32% of humus tannin content. Consistent with the results from the chemical assay, the aqueous fraction showed higher tannin signals in the 13C cross-polarization and magic-angle spinning (CPMAS) NMR spectrum than the emulsified one. As both tannin-rich humus fractions were depleted in N and high in structures derived from lignin and cutin, they did not have properties consistent with recaldtrant tannin-protein complexes proposed as a mechanism for N sequestration in humus. Further studies are needed to establish if tannin-protein structures in humus can be detected or isolated, or if tannins contribute to forest management problems observed in these ecosystems by binding to and slowing down the activity of soil enzymes.  相似文献   
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Planning for adaptation to climate change is often regarded to be a local imperative and considered to be more effective if grounded on a solid evidence base and recognisant of relevant climate projections. Research has already documented some of the challenges of making climate information usable in decision-making but has not yet sufficiently reflected on the role of the wider institutional and regulatory context. This article examines the impact of the external institutional context on the use and usability of climate projections in local government through an analysis of 44 planning and climate change (adaptation) documents and 54 semi-structured interviews with planners in England and Germany conducted between July 2013 and May 2014. We show that there is little demand for climate projections in local adaptation planning in either country due to existing policy, legal and regulatory frameworks. Local government in England has not only experienced a decline in use of climate projections, but also the waning of the climate change adaptation agenda more widely, amidst changes in the planning and regulatory framework and severe budget cuts. In Germany, spatial planning makes substantial use of past and present climate data, but the strictly regulated nature of planning prevents the use of climate projections, due to their inherent uncertainties. Findings from the two countries highlight that if we are to better understand the usability of climate projections, we need to be more aware of the institutional context within which planning decisions are made. Otherwise we run the risk of continuing to provide tools and information that are of limited use within their intended context.  相似文献   
49.
Semarang coastal area has geomorphologically complex processes, such as erosion-sedimentation, land subsidence, and tidal inundation hazard. Multi-years shoreline mapping is considered a valuable task for coastal monitoring and assessment. This paper presents maps illustrating the shoreline dynamic in a coastal area of Semarang-Indonesia using multi-sources spatial data. The segment data has been obtained by visual delineation of the topographic maps Year 1908, 1937, 1992 and Ikonos image Year 2003 as well as digital number (DN) value analysis and masking operation of Landsat MSS Year 1972 and Landsat ETM Year 2001. For the long period of almost 100 year, the shoreline dynamic in Semarang coastal area is dominated by sedimentation process. Shoreline extended to the sea as a result of man-made infrastructure and natural processes. The research's result was satisfactory and the method has proven to be effective considering lack of homogeneous data-series. However, some further improvement regarding geo-processing can be made and the accuracy can be tested in future version.  相似文献   
50.
Wetlands provide many important goods and services to human societies, and generate nonuse values as well. Wetlands are also very sensitive ecosystems that are subject to much stress from human activities. Reducing the stress on wetlands requires a spatial matching between physical planning, hydrological and ecological processes, and economic activities. Spatially integrated modelling and evaluation can support this. The present study has developed a triple layer model that integrates information and concepts from social and natural sciences to address the analysis and evaluation of land-use scenarios for a wetlands area in the Netherlands, the Vecht area. This is the floodplain of river Vecht, located in the centre of the Netherlands. The study has resulted in a set of linked spatial hydrological, ecological and economic models, formulated at the level of grids and polders. The main activities incorporated in the system of models are housing, infrastructure, agriculture, recreation and nature conservation. The formulation of alternative development scenarios is dominated by land use and land cover options that are consistent with the stimulation of agriculture, nature or recreation. Two aggregate performance indicators have been constructed from model output, namely net present value of changes and environmental quality. The spatial characteristics of these indicators are retained in a spatial evaluation that ranks scenarios.  相似文献   
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