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51.
There are multiple lines of compelling evidence, mostly from population-based studies, supporting that green tea consumption is associated with reduced risk of several human malignancies. Epigallocatechin gallate (EGCG) is a major antioxidant present in green tea. Chemopreventive effects of EGCG have been extensively investigated and well documented. These include inhibition of metabolic activation of carcinogens and/or stimulation of their detoxification, scavenging of reactive oxygen species, induction of apoptosis or differentiation of malignant or transformed cells, suppression of tumor promotion, inhibition of angiogenesis or metastasis, etc. EGCG targets many intracellular signaling molecules and events responsible for malignant transformation or abnormal cell proliferation, and NF-κB and AP-1 appear to be two of most potential targets of EGCG in its exerting chemopreventive activities.  相似文献   
52.
Carbon dioxide emissions have accelerated since the signing of the Kyoto Protocol. This discouraging development may partly be blamed on accelerating world growth and on lags in policy instruments. However, it also raises serious question concerning whether policies to reduce CO2 emissions are as effective as generally assumed. In recent years, a considerable number of studies have identified various feedback mechanisms of climate policies that often erode, and occasionally reinforce, their effectiveness. These studies generally focus on a few feedback mechanisms at a time, without capturing the entire effect. Partial accounting of policy feedbacks is common in many climate scenarios. The IPCC, for example, only accounts for direct leakage and rebound effects. This article attempts to map the aggregate effects of different types of climate policy feedback mechanisms in a cohesive framework. Controlling feedback effects is essential if the policy measures are to make any difference on a global level. A general conclusion is that aggregate policy feedback mechanisms tend to make current climate policies much less effective than is generally assumed. In fact, various policy measures involve a definite risk of ‘backfiring’ and actually increasing CO2 emissions. This risk is particularly pronounced once effects of climate policies on the pace of innovation in climate technology are considered. To stand any chance of controlling carbon emissions, it is imperative that feedback mechanisms are integrated into emission scenarios, targets for emission reduction and implementation of climate policy. In many cases, this will reduce the scope for subsidies to renewable energy sources, but increase the scope for other measures such as schemes to return carbon dioxide to the ground and to mitigate emissions of greenhouse gases from wetlands and oceans. A framework that incorporates policy feedback effects necessitates rethinking the design of the national and regional emission targets. This leads us to a new way of formulating emission targets that include feedback effects, the global impact target. Once the full climate policy feedback mechanisms are accounted for, there are probably only three main routes in climate policy that stand a chance of mitigating global warming: (a) returning carbon to the ground, (b) technological leaps in zero-emission energy technology that make it profitable to leave much carbon in the ground even in Annex II countries and (c) international agreements that make it more profitable to leave carbon in the ground or in forests.  相似文献   
53.
We used Life Cycle Assessment to scenario model the potential reductions in cumulative energy demand (both fossil and renewable) and global warming, acidifying, and ozone-depleting emissions associated with a hypothetical national transition from conventional to organic production of four major field crops [canola (Brassica rapa), corn (Zea mays), soy (Glycine max), and wheat (Triticum aestivum)] in Canada. Models of these systems were constructed using a combination of census data, published values, and the requirements for organic production described in the Canadian National Organic Standards in order to be broadly representative of the similarities and differences that characterize these disparate production technologies. Our results indicate that organic crop production would consume, on average, 39% as much energy and generate 77% of the global warming emissions, 17% of the ozone-depleting emissions, and 96% of the acidifying emissions associated with current national production of these crops. These differences were almost exclusively due to the differences in fertilizers used in conventional and organic farming and were most strongly influenced by the higher cumulative energy demand and emissions associated with producing conventional nitrogen fertilizers compared to the green manure production used for biological nitrogen fixation in organic agriculture. Overall, we estimate that a total transition to organic production of these crops in Canada would reduce national energy consumption by 0.8%, global warming emissions by 0.6%, and acidifying emissions by 1.0% but have a negligible influence on reducing ozone-depleting emissions.  相似文献   
54.
It is well established that trees help to reduce air pollution, and there is a growing impetus for green belt expansion in urban areas. Identification of suitable plant species for green belts is very important. In the present study, the Air Pollution Tolerance Index (APTI) of many plant species has been evaluated by analyzing important biochemical parameters. The Anticipated Performance Index (API) of these plant species was also calculated by considering their APTI values together with other socio-economic and biological parameters. Based on these two indices, the most suitable plant species for green belt development in urban areas were identified and recommended for long-term air pollution management.  相似文献   
55.
Previous research addressing the unequal distribution of locally desirable land (LDL) has mainly ignored their associated environments (i.e., rural or urban). However, this study proposed a new framework that treats rural and urban regions separately. In rural areas, the LDLs included all public lands. In urbanized areas, the LDLs were defined as green open spaces. Potential inequities in the distribution of LDL were assessed with respect to socioeconomic characteristics of residents in the State of Georgia. Using US Census Bureau Data (2000), Census Block Groups (CBGs) adjacent to LDLs were compared to CBGs outside of LDLs on four socioeconomic variables (per capita income, occupation, education, and race) in urban, suburban and rural environments. Results showed that CBGs adjacent to LDLs were composed of statistically significant upper-class communities containing fewer blue-collar workers, more whites, and higher income and higher educated people in rural, suburban and urban areas.  相似文献   
56.
The provision of green space is increasingly being perceived as an important factor for quality of life. However, green spaces often face high developmental pressure. The main objective of this study is to investigate a prospective approach to green space planning by combining three-dimensional (3D) visualization of green space scenarios and survey techniques to facilitate improved participation of the public. Aside from the ‘Status quo’, scenarios ‘Agriculture’, ‘Recreation’, ‘Nature conservation’ and ‘Wind turbines’ are visualized in three dimensions. In order to test responses, a survey was conducted both in print format and on the Internet. Overall, 49 different visualizations that belong to one of the scenarios were available in the survey and were rated according to the perceived esthetic, recreational and ecological values.The highest rated scenes include vegetation elements such as meadows with orchards, single trees, shrubs or forest. The least attractive scenes are those where buildings are highly dominant or where there are no vegetation elements.Based on the ratings for the individual images and on the corresponding scenarios, our study shows that there is high potential for improving the existing landscape. All suggested changes are either rated about equal to or considerably higher than the status quo, with the scenario ‘Nature conservation’ receiving the highest scores.  相似文献   
57.
传统的GDP核算模式建立在资源耗减、环境破坏和公众健康不断透支的基础之上,不能体现经济活动对自然资源的消耗和对生态环境造成的破坏。为了将环境污染损失纳入GDP核算体系,以2010年重庆市绿色GDP核算为例,运用虚拟治理成本法进行环境价值量核算。结果表明,基于环境污染损失调整后的重庆市绿色GDP为7920.28亿元,污染扣减指数为0.4%。  相似文献   
58.
可生物降解材料聚羟基脂肪酸酯(PHA)的合成与应用概述   总被引:3,自引:0,他引:3  
聚羟基脂肪酸酯(polyhydroxyalkanoates,PHA)是很多微生物合成的一种细胞内聚酯,是一种天然的高分子生物材料。PHA具有良好的生物相容性能、生物可降解性和塑料的热加工等性能。文章主要综述了PHA的合成途径与有关应用方面的研究。  相似文献   
59.
通过对工业污染防治面临的主要问题以及未来工业绿色发展态势和国家环境保护严峻形势进行深入分析,指出"十三五"是中国工业面临转型升级的重要战略机遇期,并重点从推动生产方式绿色化、发展节能环保产业、推进清洁生产和循环经济、强化污染防治力度等方面提出了工业行业在推进污染防治工作中的总体思路和发展战略。  相似文献   
60.
我国绿色金融体系构建及推进机制研究   总被引:1,自引:0,他引:1  
重点围绕绿色金融机构和绿色金融产品,研究构建基于绿色银行、绿色信贷、绿色债券、绿色股票、绿色信托、绿色保险、绿色基金、绿色租赁的我国绿色金融体系。从监督管理、财税激励、社会责任、信息传导等方面入手,分析识别我国绿色金融体系推进机制,并从近期和远期两个时间维度提出绿色金融体系完善建议。  相似文献   
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