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1.
Human activities have significantly intensified natural phosphorus cycles, which has resulted in some serious environmental problems that modern societies face today. This article attempts to quantify the global phosphorus flows associated with present day mining, farming, animal feeding, and household consumption. Various physical characteristics of the related phosphorus fluxes as well as their environmental impacts in different economies, including the United States, European countries, and China, are examined. Particular attention is given to the global phosphorus budget in cropland and the movement and transformation of phosphorus in soil, because these phosphorus flows, in association with the farming sector, constitute major fluxes that dominate the anthropogenic phosphorus cycle. The results show that the global input of phosphorus to cropland, in both inorganic and organic forms from various sources, cannot compensate for the removal in harvests and in the losses by erosion and runoff. A net loss of phosphorus from the world's cropland is estimated at about 10.5 million metric tons (MMT) phosphorus each year, nearly one half of the phosphorus extracted yearly.  相似文献   

2.
Phosphorus (P) is central to food production. Current understanding about the global phosphorus system is dominated by studies in wealthier nations where soil fertility, fertilizer supply chains, and agronomic tracking have long been established. In contrast, developing nations are experiencing major agricultural transitions and the associated phosphorus flows remain a significant knowledge gap. We compiled and analyzed several years of recent agricultural datasets for Bangladesh, currently the eighth most populous nation, using substance flow analysis for phosphorus. From 2000 to 2016, rice production increased by >50% and remained the dominant crop with remarkably higher phosphorus flow (49.96 kt in 2016) than all other crops. Phosphorus content of livestock products in 2016 exceeded 6.00 kt, more than double in the year 2000, driven primarily by phosphorus in milk and secondarily in meat/eggs. These agricultural changes coincided with a doubling of national phosphorus fertilizer consumption since 2000, a fourfold increase since the global food crisis (2009), and a pronounced rise in the phosphorus import dependency ratio, which was the highest among all countries compared. In turn, during 2010s fertilizer phosphorus use exceeded phosphorus as food + feed production leading to soil phosphorus accumulation, and loss as burned manure became one of the largest phosphorus flows in the entire system, equivalent to half of fertilizer use. This dramatic reconfiguration of the Bangladesh phosphorus system illustrates an important case of agricultural expansion and intensification that is still playing out, with similar situations occurring in developing nations where population growth rates are high, and access to commercial fertilizers has risen.  相似文献   

3.
Phosphorus (P) is a major agricultural nutrient and, in its mineable form, a potentially scarce resource. Countries with limited physical access to P should hence develop an effective national P governance. This requires analyses of trends and variations in P flows and stocks over time. Here, we present a long‐term P flow analysis for the Indian agri‐food sector from 1988 to 2011. Major P flows are imports of mineral P, fertilizer application, and uptake of animal fodder. The mineral P import dependency ratio is constant at around 93%. On average, 20% of P inputs to soils are lost through erosion. Key drivers of changes in P flows include population growth, dietary change, and agricultural intensification. To reduce its P fertilizer import dependence, India could, for example, substitute up to 19% of the presently applied mineral P if manure used as a household fuel were recycled, and up to 21% if P was fully recovered from wastewater and household waste. Comparing selected indicators for P use in agriculture with China and the European Union (EU) reveals that there are structural similarities, such as increasing fertilizer application rates and P accumulation in soils, with the first but large differences compared to the latter. The analyses highlight that in contrast to static indicators, the time‐continuous tracking of P flows provides substantial advantages, such as the identification of long‐term trends, drivers, and intervention options for sustainable P management, given that it allows for the interpretation of present indicators in the context of past trends and legacies.  相似文献   

4.
Modern human activities greatly disturb substance flows in nature and senselessly discard massive amounts of precious resources to natural waste reservoirs; phosphorus (P) is a good example of this. In this article, substance flow analysis is employed to quantify and explore the temporal evolution of China's P consumption in main metabolic nodes from 1984 to 2008, and then the environmental implications for P flows into both surface waters and natural soil are investigated. Results show that the metabolic nodes of human life and animal husbandry have demanded increasingly more P inputs, while disseminating more and more P wastes, with the waste recycling ratios of these processes dropping, respectively, from 65.9% and 66.1% in 1984 to 50.7% and 40.6% by 2008. These change traits were closely related to national polices including the Household Contract Responsibility System and the Shopping Basket Program, as well as the policy vacuum existing between China's agricultural and environmental administration departments. To achieve high crop yield, increasingly more inorganic P fertilizers have been utilized in China, but their use efficiency has decreased by 46.3%. From 2003 to 2008, the total P load into surface waters was stabilized at about 900.0 kilotons (kt), while the total P load into natural soil increased by more than 3.8 times to 3,131.3 kt P in 2008. City life and the intensive breeding of crops are identified as the main targets for further pollution control and nutrient recycling in China. Some suggestions for achieving environmentally sound practices and resource sustainability in China are proposed at the end of this article.  相似文献   

5.
傅银银  袁增伟  武慧君  张玲 《生态学报》2012,32(5):1578-1586
氮、磷等营养物质过量输入是造成我国湖泊富营养化问题日益严重的根源,磷作为水体富营养化过程关键限制元素,主要来自流域社会经济系统中的人类活动排放,因此,定量刻画社会经济系统内的磷流动路径是追踪水体外源磷来源和进行有效控制磷排放量的前提。以巢湖流域的安徽省含山县为例,构建社会经济系统磷流分析框架,建立磷流核算模型,并在实地调查和数据统计分析的基础上定量刻画了含山县2008年度社会经济系统磷流路径。结果表明,2008年含山县社会经济系统向水体排放的磷总量为1592t,其中农业种植子系统的排放所占比例最大(77%),该子系统的磷利用效率也较低(45%)。因此,含山县富营养化治理的重点是优化农业种植系统的磷流路径,主要措施包括合理施肥、科学排灌等。  相似文献   

6.
Despite major improvements in recycling over the last decades, the pulp and paper sector is a significant contributor to global greenhouse gas emissions and other environmental pressures. Further reduction of virgin material requirements and environmental impacts requires a detailed understanding of the global material flows in paper production and consumption. This study constructs a Sankey diagram of global material flows in the paper life cycle, from primary inputs to end‐of‐life waste treatment, based on a review of publicly available data. It then analyzes potential improvements in material flows and discusses recycling and material efficiency metrics. The article argues that the use of the collection rate as a recycling metric does not directly stimulate avoidance of virgin inputs and associated impacts. An alternative metric compares paper for recycling (recovered paper) with total fibrous inputs and indicates that the current rate is at just over half of the technical potential. Material efficiency metrics are found to be more useful if they relate to the reuse potential of wastes. The material balance developed in this research provides a solid basis for further study of global sustainable production and consumption of paper. The conclusions on recycling and efficiency should be considered for improving environmental assessment and stimulating a shift toward resource efficiency and the circular economy.  相似文献   

7.
Changes in food consumption and related processes have a significant impact on the flow of nitrogen in the environment. This study identifies both flows within the system and emissions to the hydrosphere and atmosphere. A case study of an average inhabitant of the city of Linköping, Sweden, covers the years 1870, 1900, 1950, and 2000 and includes changes in food consumption and processing, agricultural production, and organic waste handling practices. Emissions to the hydrosphere from organic waste handling increased from 0.57 kilograms of nitrogen per capita per year (kg N/cap per year) to 3.1 kg N/cap per year, whereas the total flow of nitrogen to waste deposits grew from a negligible amount to 1.7 kg N/cap per year. The largest flow of nitrogen during the entire period came from fodder. The input of chemical fertilizer rose gradually to a high level of 15 kg N/cap per year in the year 2000. The total load per capita disposed of to the environment decreased during these 130 years by about 30%.  相似文献   

8.
The Multilevel Cycle of Anthropogenic Zinc   总被引:2,自引:0,他引:2  
A comprehensive annual cycle for stocks and flows of zinc, based on data from circa 1994 and incorporating information on extraction, processing, fabrication, use, discard, recycling, and landfilling, was carried out at three discrete governmental unit levels—54 countries and 1 country group (which together comprise essentially all global anthropogenic zinc stocks and flows), nine world regions, and the planet as a whole. All of these cycles are available in an electronic supplement to this article, which thus provides a metadata set on zinc flows for the use of industrial ecology researchers. A "best estimate" global zinc cycle was constructed to resolve aggregation discrepancies. Among the most interesting results are the following: (1) The accumulation ratio, that is, addition to in-use stock as a function of zinc entering use, is positive and large (2/3 of zinc entering use is added to stock) (country, regional, and global levels); (2) secondary input ratios (fractions of input to fabrication that are from recycled zinc) and domestic recycling percentages (fractions of discarded zinc that are recycled) differ among regions by as much as a factor of six (regional level); (3) worldwide, about 40% of the zinc that was discarded in various forms was recovered and reused or recycled (global level); (4) zinc cycles can usefully be characterized by a set of ratios, including, notably, the utilization efficiency (the ratio of manufacturing waste to manufacturing output: 0.090) and the prompt scrap ratio (new scrap as a fraction of manufacturing input: 0.070) (global level). Because capturable discards are a significant fraction of primary zinc inputs, if a larger proportion of discards were recaptured, extraction requirements would decrease significantly (global level). The results provide a framework for complementary studies in resource stocks, industrial resource utilization, energy consumption, waste management, industrial economics, and environmental impacts.  相似文献   

9.
The identification of potential by‐product exchanges is important for fostering industrial symbiosis. To discover these potential exchanges, this article extends the analysis of local industrial symbiosis to a national scale. A waste input‐output table, which is a material flow accounting tool, was compiled and used as a database to examine the existing exchanges of by‐products. The supplies and demands of industrial wastes or by‐products were compared to highlight their potential use for promoting higher exchange flows. The analysis of the linkages indicated that the majority of each of the by‐products were reused by the few industries that had the technology and operational capacity for reuse. This finding is useful for determining which industries are good candidates for promoting further industrial symbiosis (IS). Based on a nation‐wide analysis that considered the industrial characteristics of Taiwan comprehensively, 23 types of major by‐products with greater reuse flows and 216 potential exchange patterns were identified between the industries. In addition, three types of eco‐industrial networks were characterized as follows according to their dominant types: (1) fossil fuel, metal, and mineral‐dominated; (2) agricultural and synthetic material‐dominated; and (3) information and communications technology (ICT) and chemical industry‐dominated eco‐industrial networks. This analysis highlights the resource exchange potentials and provides information to new firms for networking with existing businesses.  相似文献   

10.
The Changing Metabolism of Cities   总被引:7,自引:0,他引:7  
Data from urban metabolism studies from eight metropolitan regions across five continents, conducted in various years since 1965, are assembled in consistent units and compared. Together with studies of water, materials, energy, and nutrient flows from additional cities, the comparison provides insights into the changing metabolism of cities. Most cities studied exhibit increasing per capita metabolism with respect to water, wastewater, energy, and materials, although one city showed increasing efficiency for energy and water over the 1990s. Changes in solid waste streams and air pollutant emissions are mixed.
The review also identifies metabolic processes that threaten the sustainability of cities. These include altered ground water levels, exhaustion of local materials, accumulation of toxic materials, summer heat islands, and irregular accumulation of nutrients. Beyond concerns over the sheer magnitudes of resource flows into cities, an understanding of these accumulation or storage processes in the urban metabolism is critical. Growth , which is inherently part of metabolism, causes changes in water stored in urban aquifers, materials in the building stock, heat stored in the urban canopy layer, and potentially useful nutrients in urban waste dumps.
Practical reasons exist for understanding urban metabolism. The vitality of cities depends on spatial relationships with surrounding hinterlands and global resource webs. Increasing metabolism implies greater loss of farmland, forests, and species diversity; plus more traffic and more pollution. Urban policy makers should consider to what extent their nearest resources are close to exhaustion and, if necessary, appropriate strategies to slow exploitation. It is apparent from this review that metabolism data have been established for only a few cities worldwide, and interpretation issues exist due to lack of common conventions. Further urban metabolism studies are required.  相似文献   

11.
Trends of increasing agricultural trade, increased concentration of livestock production systems, and increased human consumption of livestock products influence the distribution of nutrients across the global landscape. Phosphorus (P) represents a unique management challenge as we are rapidly depleting mineable reserves of this essential and non-renewable resource. At the same time, its overuse can lead to pollution of aquatic ecosystems. We analyzed the relative contributions of food crop, feed crop, and livestock product trade to P flows through agricultural soils for 12 countries from 1961 to 2007. Due to the intensification of agricultural production, average soil surface P balances more than tripled from 6 to 21 kg P ha−1 between 1961 and 2007 for the 12 study countries. Consequently, countries that are primarily agricultural exporters carried increased risks for water pollution or, for Argentina, reduced soil fertility due to soil P mining to support exports. In 2007, nations imported food and feed from regions with higher apparent P fertilizer use efficiencies than if those crops were produced domestically. However, this was largely because imports were sourced from regions depleting soil P resources to support export crop production. In addition, the pattern of regional specialization and intensification of production systems also reduced the potential to recycle P resources, with greater implications for livestock production than crop production. In a globalizing world, it will be increasingly important to integrate biophysical constraints of our natural resources and environmental impacts of agricultural systems into trade policy and agreements and to develop mechanisms that move us closer to more equitable management of non-renewable resources such as phosphorus.  相似文献   

12.
Mineral phosphorus (P) used to fertilise crops is derived from phosphate rock, which is a finite resource. Preventing and recycling mineral P waste in the food system, therefore, are essential to sustain future food security and long-term availability of mineral P. The aim of our modelling exercise was to assess the potential of preventing and recycling P waste in a food system, in order to reduce the dependency on phosphate rock. To this end, we modelled a hypothetical food system designed to produce sufficient food for a fixed population with a minimum input requirement of mineral P. This model included representative crop and animal production systems, and was parameterised using data from the Netherlands. We assumed no import or export of feed and food. We furthermore assumed small P soil losses and no net P accumulation in soils, which is typical for northwest European conditions. We first assessed the minimum P requirement in a baseline situation, that is 42% of crop waste is recycled, and humans derived 60% of their dietary protein from animals (PA). Results showed that about 60% of the P waste in this food system resulted from wasting P in human excreta. We subsequently evaluated P input for alternative situations to assess the (combined) effect of: (1) preventing waste of crop and animal products, (2) fully recycling waste of crop products, (3) fully recycling waste of animal products and (4) fully recycling human excreta and industrial processing water. Recycling of human excreta showed most potential to reduce P waste from the food system, followed by prevention and finally recycling of agricultural waste. Fully recycling P could reduce mineral P input by 90%. Finally, for each situation, we studied the impact of consumption of PA in the human diet from 0% to 80%. The optimal amount of animal protein in the diet depended on whether P waste from animal products was prevented or fully recycled: if it was, then a small amount of animal protein in the human diet resulted in the most sustainable use of P; but if it was not, then the most sustainable use of P would result from a complete absence of animal protein in the human diet. Our results apply to our hypothetical situation. The principles included in our model however, also hold for food systems with, for example, different climatic and soil conditions, farming practices, representative types of crops and animals and population densities.  相似文献   

13.
This article presents Swedish economy‐wide material flow accounts for the period 1987‐1998. It also shows possibilities for enhancing the international comparability of aggregated data on material use, by distinguishing between materials used for consumption and export purposes. The direct material input (DMI) is used as an aggregate measure to estimate the amounts of natural resources (except water and air) that are taken from nature into the economy within a year, including imports to and production within the region in question. The division of materials used for consumption and export purposes avoids double counting trade flows when DMI is applied to a group of countries. The annual DMI in Sweden for 1997‐1998, including production and imports, amounts to 24 to 27 metric tons per capita (t/c). The fossil fuel input varies only slightly over the period, from 3.2 t/c in 1991 to 3.6 t/c in 1996, a level deemed unsustainable by the Swedish Environmental Protection Agency. The input of renewable raw materials varies between 8 and 9 t/c. Ores and minerals vary between 11 and 15 t/c. The DMI puts Sweden above estimates made for Germany, the United States, and Japan and in the same range as the Netherlands. The differences in these values can mainly be explained by the relative importance of exports as compared to the size of the economy and by the variation in system boundaries for the data on natural resources. The system boundaries and data sources for natural resources need to be further defined to make the measures fully comparable. Around 5 t/c is exported, whereas the rest, around 20 t/c, is national consumption. The aggregate direct material consumption (DMC), which is the DMI minus exports, communicates the magnitude of resource use. Comparisons of the input with solid waste statistics indicate that quantity of waste (excluding mining waste) in Sweden is equal to about 10% relative of the total resource use. Material collected for recycling by the waste management system is equal to about 5% of the amount of virgin resources brought into society each year.  相似文献   

14.
Material flow analysis is a tool that is increasingly used as a foundation for resource management and environmental protection. This tool is primarily applied in a static manner to individual years, ignoring the impact of time on the material budgets. In this study, a detailed multiyear model of the Austrian phosphorus budget covering the period 1990–2011 was built to investigate its behavior over time and test the hypothesis that a multiyear approach can also contribute to the improvement of static budgets. Further, a novel method was applied to investigate the quality and characteristics of the data and quantify the uncertainty. The degree of change between the budgets was assessed and showed that approximately half of the flows have changed significantly and, at times, abruptly since 1990, but it is not possible to distinguish unequivocally between constant and moderately changing flows given their uncertainty. The study reveals that the phosphorus transported in waste flows has increased more rapidly than its recovery, which accounted for 55% to 60% of the total waste phosphorus in 1990 and only 40% in 2011. The loss ratio in landfills and cement kilns has oscillated in the range of 40% to 50%. From a methodological point of view, the multiyear approach has broadened the conceptual model of the budget, making it more suitable as a basis for material accounting and monitoring. Moreover, the analysis of the data reconciliation process over a long period of time proved to be a useful tool for identifying systematic errors in the model.  相似文献   

15.
Regional Patterns in Global Resource Extraction   总被引:1,自引:0,他引:1  
This article presents an account of global resource extraction for the year 1999 by material groups, world regions, and development status. The account is based on materials flow analysis methodology and provides benchmark information for political strategies toward sustainable resource management. It shows that currently around 50 thousand megatons of resources are extracted yearly on a global scale, which results in a yearly global average resource use of around 8 tonnes per capita. Assuming further growth in world regions not yet close to the levels of resource use in the industrial cores—such as India or China—numbers could easily double once these parts of the world come to fully incorporate the industrial mode of production and consumption. This article contributes to information on resource use indicators, complementing and enriching information from economic accounting in order to facilitate political measures toward a sustainable use of resources.  相似文献   

16.
磷元素物质流分析研究进展   总被引:6,自引:1,他引:5  
陈敏鹏  郭宝玲  刘昱  夏旭  陈吉宁 《生态学报》2015,35(20):6891-6900
磷是重要的营养元素,也是不可再生的重要非金属矿物资源。为了分析人类活动对磷流动的扰动,国内外开展了大量磷元素的物质流分析和模拟。综述了磷元素物质流分析的最新研究进展,分析了国内外磷元素物质流研究的特点和不足,并展望了未来相关研究的研究热点和发展方向。从研究尺度看,现有磷元素的物质流研究以全球尺度和国家尺度为主,区域和城市尺度以及企业和产品尺度的研究较少。从研究问题看,现阶段研究主要关注农业或者食品生产和消费对磷流动的影响,对林业、钢铁和能源部门略有涉及。从模型特征看,现有研究以分析流量变化的静态模型为主,考虑存量变化的动态模拟较少。从研究的发展方向看,未来磷物质流的相关分析将关注五大问题:(1)考虑不同驱动力和存量变化的动态模拟;(2)不同层次和尺度的磷足迹研究;(3)磷与其他元素相比对社会经济的重要性;(4)全球变化背景下不同部门磷依赖的脆弱性;(5)磷和其他元素的耦合研究。为了适应未来的研究需求,磷的物质流模拟重点在于开发动态模型,并将物质流分析与多种手段结合,以预测全球变化、社会经济发展、技术变化以及其他重要变化对磷流动的扰动及其相应的环境影响。  相似文献   

17.
Despite accounting for almost 50% of global material use, nonmetallic minerals—mostly used for construction of buildings and infrastructure—are the material flow analysis (MFA) category with the highest uncertainty. The main reason for this is incomplete reporting in official national statistics because of ease of availability and the low per‐unit cost of these materials. However, the environmental burden associated with nonmetallic minerals, which include energy use for extraction and transport, land‐use change, and disposal of large amounts of construction demolition waste, call for a thorough understanding of the magnitude of nonmetallic mineral flows. Previous estimates for nonmetallic minerals have used simplistic assumptions. This study aims to increase the precision of nonmetallic mineral accounts at national and global level using consumption of bitumen, bricks, cement, and railways in combination with technical coefficients from the engineering literature to infer the actual yearly consumption of nonmetallic minerals. We estimate the extraction of nonmetallic minerals and provide uncertainty estimates for the new accounts as well as information about consumption by different sectors. Analyzing the evolution of consumption for seven world regions, we find that, in North America and Europe, the consumption of nonmetallic minerals over the past 40 years has followed the growth patterns of population, whereas for all other regions consumption has been closely related to gross domestic product (GDP). A more accurate account of global and country‐by‐country extraction of nonmetallic minerals may provide insights into supply shortages and inform waste management strategies for construction and demolition waste.  相似文献   

18.
Carbon‐based materials (CBMs) for energetic and material purposes combine biogenic and anthropogenic carbon cycles. In the latter, numerous manufactured products with various in‐use lifespans accumulate as anthropogenic carbon stocks. Understanding the behavior of these stocks is an important requirement to estimate not only future waste amounts, source for secondary raw materials, but also the impacts and effects in carbon emissions and carbon management. Previous models have estimated material stock changes; however, a lack of research in carbon stocks is perceived. Moreover, studies follow in‐use lifespan estimation approaches, such as decay functions, which do not coincide with observed consumption and waste treatment patterns. In the first part of this article, we present a carbon stock‐flow model to analyze inter‐relationships between carbon flows and stocks from raw materials to waste treatment processes considering a consumer perspective, where the dynamics of anthropogenic carbon stocks are completely described. In the second part, we study the pulp and paper industry in Germany under a scenario approach to analyze the behavior, development, and impacts of paper stocks and flows between 2010 and 2040. The model provided coherent results, with industrial data estimating 33.9 million metric tons in 2010 in paper stocks, equivalent to 410 kilograms per person. Consumption per capita and in‐use lifespan of products were identified as the most significant variables in carbon stock building. Model simulations show a sustained growth in stocks for the next 30 years, with increase in waste and carbon emissions. But in combination with recycling and reuse mechanisms and consumption patterns, environmental impacts are reduced.  相似文献   

19.
The international industrial ecology (IE) research community and United Nations (UN) Environment have, for the first time, agreed on an authoritative and comprehensive data set for global material extraction and trade covering 40 years of global economic activity and natural resource use. This new data set is becoming the standard information source for decision making at the UN in the context of the post‐2015 development agenda, which acknowledges the strong links between sustainable natural resource management, economic prosperity, and human well‐being. Only if economic growth and human development can become substantially decoupled from accelerating material use, waste, and emissions can the tensions inherent in the Sustainable Development Goals be resolved and inclusive human development be achieved. In this paper, we summarize the key findings of the assessment study to make the IE research community aware of this new global research resource. The global results show a massive increase in materials extraction from 22 billion tonnes (Bt) in 1970 to 70 Bt in 2010, and an acceleration in material extraction since 2000. This acceleration has occurred at a time when global population growth has slowed and global economic growth has stalled. The global surge in material extraction has been driven by growing wealth and consumption and accelerating trade. A material footprint perspective shows that demand for materials has grown even in the wealthiest parts of the world. Low‐income countries have benefited least from growing global resource availability and have continued to deliver primary materials to high‐income countries while experiencing few improvements in their domestic material living standards. Material efficiency, the amount of primary materials required per unit of economic activity, has declined since around 2000 because of a shift of global production from very material‐efficient economies to less‐efficient ones. This global trend of recoupling economic activity with material use, driven by industrialization and urbanization in the global South, most notably Asia, has negative impacts on a suite of environmental and social issues, including natural resource depletion, climate change, loss of biodiversity, and uneven economic development. This research is a good example of the IE research community providing information for evidence‐based policy making on the global stage and testament to the growing importance of IE research in achieving global sustainable development.  相似文献   

20.
高浓度氯化铵工业废水对农作物的污染与毒理试验   总被引:1,自引:0,他引:1  
为探讨含高浓度氯化铵工业废水对环境与家作物的影响,采用毒理试验方法进行较系统的研究.结果表明,含高浓度氯化铵的工业废水使附近的地面水及土壤受到不同程度的污染,虽然氯化铵是农田肥料的一种,但浓度较高时仍对农作物有致死、致伤及抑制生长的危害,因此,含有高浓度氯化铵的工业废水的处理和对环境造成的影响应予以重视.  相似文献   

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