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1.
大小兴安岭生态资产变化格局   总被引:5,自引:3,他引:2  
马立新  覃雪波  孙楠  杨国亭 《生态学报》2013,33(24):7838-7845
利用遥感定量测量,采用Landsat 25卫星数据及其他辅助数据,结合生态学方法,对大小兴安岭的18个县市2004年和2011年两个年度的生态资产进行评估,分析其分布格局及其变化。结果表明生态资产空间格局呈现中部较高,南北部较低的特征;从2004到2011年,生态资产总量由2379.26 亿元减少到2308.53 亿元,减少了2.97%,减少幅度较小,说明总量相对稳定;然而,各县市生态资产变化趋势不同,变化幅度从-29.54%到26.38%之间,即从中度退化到中度增长;随着经济发展,国内生产总值在生态资产中的比重增高。研究表明,经济发展水平不同的区域应该采取不同的资源利用方式,提高生态资产,促进当地可持续发展。  相似文献   

2.
Agricultural sustainability: concepts, principles and evidence   总被引:1,自引:0,他引:1  
Concerns about sustainability in agricultural systems centre on the need to develop technologies and practices that do not have adverse effects on environmental goods and services, are accessible to and effective for farmers, and lead to improvements in food productivity. Despite great progress in agricultural productivity in the past half-century, with crop and livestock productivity strongly driven by increased use of fertilizers, irrigation water, agricultural machinery, pesticides and land, it would be over-optimistic to assume that these relationships will remain linear in the future. New approaches are needed that will integrate biological and ecological processes into food production, minimize the use of those non-renewable inputs that cause harm to the environment or to the health of farmers and consumers, make productive use of the knowledge and skills of farmers, so substituting human capital for costly external inputs, and make productive use of people's collective capacities to work together to solve common agricultural and natural resource problems, such as for pest, watershed, irrigation, forest and credit management. These principles help to build important capital assets for agricultural systems: natural; social; human; physical; and financial capital. Improving natural capital is a central aim, and dividends can come from making the best use of the genotypes of crops and animals and the ecological conditions under which they are grown or raised. Agricultural sustainability suggests a focus on both genotype improvements through the full range of modern biological approaches and improved understanding of the benefits of ecological and agronomic management, manipulation and redesign. The ecological management of agroecosystems that addresses energy flows, nutrient cycling, population-regulating mechanisms and system resilience can lead to the redesign of agriculture at a landscape scale. Sustainable agriculture outcomes can be positive for food productivity, reduced pesticide use and carbon balances. Significant challenges, however, remain to develop national and international policies to support the wider emergence of more sustainable forms of agricultural production across both industrialized and developing countries.  相似文献   

3.
In this article, I seek to identify a limitation in the analysis James Scott offers in Seeing Like a State (1998) by asking to what extent his account of the follies of schemes for planned improvement by states provides critical leverage on the present world of neoliberal global capitalism. Scott has claimed that a dynamic of standardization, homogenization, and grid making applies not only to developmentalist states but also equally to the contemporary world of downsized states and unconstrained global corporations. I contest that claim by tracing how recent capital investment in Africa has been territorialized, and some of the new forms of order and disorder that have accompanied that selectively territorialized investment. Because such investment has been overwhelmingly in mineral resource extraction—particularly in oil—a contrast will become visible between the homogenizing, standardizing state optic Scott analyzed and a rather different way of seeing, proper to the contemporary global oil company.  相似文献   

4.
Driving a car enables many people to engage in meaningful activities that, in turn, help develop and maintain personal social capital. Social capital, a combination of community participation and social cohesion, is important in maintaining well-being. This paper argues that social capital can provide a framework for investigating the general role of transportation and driving a car specifically to access activities that contribute to connectedness and well-being among older people. This paper proposes theoretically plausible and empirically testable hypotheses about the relationship between driver status, social capital, and well-being. A longitudinal study may provide a new way of understanding, and thus of addressing, the well-being challenges that occur when older people experience restrictions to, or loss of, their driver’s license.  相似文献   

5.
We argue that the dead donor rule, which states that multiple vital organs should only be taken from dead patients, is justified neither in principle nor in practice. We use a thought experiment and a guiding assumption in the literature about the justification of moral principles to undermine the theoretical justification for the rule. We then offer two real world analogues to this thought experiment, voluntary active euthanasia and capital punishment, and argue that the moral permissibility of terminating any patient through the removal of vital organs cannot turn on whether or not the practice violates the dead donor rule. Next, we consider practical justifications for the dead donor rule. Specifically, we consider whether there are compelling reasons to promulgate the rule even though its corresponding moral principle is not theoretically justified. We argue that there are no such reasons. In fact, we argue that promulgating the rule may actually decrease public trust in organ procurement procedures and medical institutions generally – even in states that do not permit capital punishment or voluntary active euthanasia. Finally, we examine our case against the dead donor rule in the light of common arguments for it. We find that these arguments are often misplaced – they do not support the dead donor rule. Instead, they support the quite different rule that patients should not be killed for their vital organs.  相似文献   

6.
A consensus has been forged in the last decade that recent periods of sustained growth in total factor productivity and reduced poverty are closely associated with improvements in a population's child nutrition, adult health, and schooling, particularly in low-income countries. Estimates of the productive returns from these three forms of human capital investment are nonetheless qualified by a number of limitations in our data and analytical methods. This paper reviews the problems that occupy researchers in this field and summarizes accumulating evidence of empirical regularities. Social experiments must be designed to assess how randomized policy interventions motivate families and individuals to invest in human capital, and then measure the changed wage opportunities of those who have been induced to make these investments. Statistical estimation of wage functions that seek to represent the relationship between wage rates and a variety of human capital stocks may yield biased estimates of private rates of return from these investments for a variety of reasons. The paper summarizes several of these problems and illustrates how data and statistical methods can be used to deal with some of them. The measures of labor productivity and the proxies specified for schooling and adult health are first discussed, and then the functional relationships between human capital and wages are described. Three types of estimation problem are discussed: (1) bias due to omitted variables, such as ability or frailty; (2) bias due to the measurement of an aggregation of multiple sources of human capital, e.g. genetic and socially reproducible variation, which may contribute to different gains in worker productivity; and (3) errors in measurement of the human capital stocks. Empirical examples and illustrative estimates are surveyed.  相似文献   

7.
This article examines how ethnic capital operates in ethnic affinity migration and external citizenship. Criticizing the “methodological nationalism”, inadequate theorization of the state, and “groupist” understanding of ethnicity that characterize existing scholarship on ethnic capital, I develop an alternative account drawing on Bourdieu. I highlight the importance of state power that consecrates ethnicity as a legitimate element in classifying non-citizens and determines the key criteria for coethnicity. The conversion of ethnicity into a migration-facilitating resource, however, is not monopolized by the state. I pay attention to how aspiring migrants, assisted by various intermediaries, challenge the state’s definition of ethnic group boundaries or deliberately cultivate specific ethnic markers, with varying implications for their ethnic self-understanding. Instead of treating ethnicity as what migrants are, I analyse what states, migrants, and intermediaries do with ethnicity – how they shape the valorization, conversion, and legitimization of ethnic capital in macro-political, meso-institutional, and micro-interactional contexts, with different agendas and asymmetrical power.  相似文献   

8.
Teacher professional development (PD) is often extended as a driver of good teaching and effective schools. In recent years, teacher PD has increasingly focused on developing teacher social capital by placing teachers within professional communities to collectively solve instructional problems. Using Bourdieu's and Coleman's conceptions of social capital as a theoretical and practical lens, this article explores how a social capital frame could generate more effective PD policy in music education. Areas examined also include the specific ways in which social capital becomes a lever for teacher growth and school improvement and the social dimensions of music teacher PD. The article concludes with principles of social capital-advancing PD policy, examples of principle-aligned PD policies, implications for research and advocacy, and an accounting of challenges and opportunities for the future. The author argues that centralizing social capital development as an aim of PD represents a new frontier in music teacher learning.  相似文献   

9.
Social capital takes on distinctive meaning in the context of large-scale immigration from poor to rich countries. In this article, characteristics of social capital embedded in transnational networks and norms, conditions conducive to the formation of such networks, and effects such networks have are extrapolated from an analysis of how and why cross-border relations among Cuban-Americans and Cubans in their homeland have changed since the 1959 Castro-led revolution. The transnational social capital generating benefit on which the study focuses is remittances. Remittances are of growing global importance to less developed countries, and in some countries they generate more revenue than foreign aid and foreign investment. The analysis addresses a range of unintended as well as intended consequences remittances may have.  相似文献   

10.
This paper investigates the long-term relationship between early life exposure to malaria and human capital accumulation in Brazil. The identification strategy relies on exogenous variation in the risk of malaria outbreaks in different states and seasons of the year to identify in utero exposure according to the timing and location of birth. I find consistent negative treatment effects of in utero exposure to malaria on educational attainment. The effects are stronger for exposure during the first trimester of pregnancy than during other periods of gestation. Effective anti-malaria policies can, thus, be an important factor contributing to reducing the educational inequality by targeting pregnant women, especially those in their first months of gestation.  相似文献   

11.
Arsenic is one of the most important water pollutants because of its carcinogenicity. The association between arsenical poisoning and the development of internal malignancies and skin cancer is well known. The U.S. Environmental Protection Agency (USEPA) sets maximum contaminant level goals at zero for carcinogens. In this study are presented groundwater arsenic concentrations in the area of naturally rich boron sources of Turkey. Water samples were collected from the Hisarcik, Turkey, area, which has a large boron mine. An inductively coupled plasma/mass spectrometry method was used to analyze arsenic concentrations in water samples. The arsenic levels in water ranged from no detectable amounts to 3.00 mg As/L (mean: 0.46 ± 0.07SD). This mean As level exceeds by a factor of 10 the USEPA's current Maximum Contaminant Level of 0.05 mgAs/L. Some possible health problems associated with consumption of arsenic-contaminated water are discussed and public health interventions proposed.  相似文献   

12.
13.
气候,地形,植被与西部环境重建   总被引:3,自引:1,他引:2  
植被是生态环境的标志,植被类型与气候和地形条件关系密切,重建西部生态环境,依据自然规律,因地制宜,做出长远规划,否则,将会事倍功半。  相似文献   

14.
王璐  陈赛娟 《遗传》2001,23(3):269-275
肿瘤是当前危害人类健康最严重的疾病之一。从某种程度上说,它是一种遗传性疾病,然而在肿瘤发生、发展的多个阶段里,环境因素及其它非遗传性因素也起到了明显的作用。现在认为单纯遗传因素仅能解释大约5%的肿瘤的发病机制,而大部分肿瘤的发病机制归因于外界环境因素与遗传性、获得性肿瘤易感性之间的协同作用。值得注意的是,部分肿瘤易感性来自人类基因组的多样性。因此,环境、人类基因组及肿瘤三者之间有密不可分的关系。综合所有来自流行病学和实验室研究的信息,净化环境、给予高危人群特殊的保护,将会逐渐降低肿瘤的发病率。 Abstract:Cancer is one of the most serious diseases that thre aten human being today.To some degree,it is a genetic disease but environmental and other nongenetic factors clearly play a role in many stages of neoplastic pr ocess.Genetic factors by themselves are thought to explain only about 5% of all cancer.The remainder can be attributed to external,“environment” factors that act in conjunction with both genetic and acquired susceptibility.Of note,part of the susceptibility is owing to the variety of human genome.So,environment,human genome and cancer have much to do with each other.Combining all of the informat ion from epidemiology and from research works in laboratory with policy-making and clinical works,purifying the environment,giving special protection to the po pulation at high risk,the mobility of cancer may decrease gradually in the future.  相似文献   

15.
This paper explores the role of recreational sport as a means and marker of social integration by analysing the lived experiences of Somali people from refugee backgrounds with sport. Drawing on a three-year multi-sided ethnography, the paper examines the extent to and ways in which participation in sport contributes to Somali Australians' bonding, bridging, and linking social capital. It is shown how social bonds and bridges developed in the sports context assist in the (re)building of community networks that have been eroded by war and displacement. Sport's contribution to social capital should however be neither overstated nor over-generalized. Bridging social capital in sport is relatively weak and few bridges are established between Somalis and the host community. Negative social encounters such as discrimination and aggression can highlight and reinforce group boundaries. Access to and use of linking social capital is also unequally distributed across gender, age, ethnic, and socio-economic lines.  相似文献   

16.
Sleep has been shown to affect economic outcomes, including wages. The mechanisms by which sleep affects wages remain unclear. We examine the relationship between chronotype – morning larks, evening owls – and wages at mid-age. We propose a novel model relating chronotype to wages in consideration of human, social, and health capital constructs. Empirically, we explore the effects of chronotype mediated through life course choices, such as work experience, trust, and health behaviour. The data come from the 46-year-old follow-up study of the Northern Finland Birth Cohort (1966) and from registers of the Finnish Tax Administration. We find evening chronotype to have a significant indirect negative effect on wages, which occurs through accumulating less work experience and through poor health outcomes. The effect is largest for male workers, with a total indirect effect on average wages of − 4%. We also provide evidence that chronotype has a long-term association with wages between 29 and 50 years of age. We conclude that evening-type workers are less suited to typical working hours and accumulate less human, social and health capital which in turn negatively affects their wages. Our findings are of great socio-economic importance because evening chronotypes make up a significant part of the population.  相似文献   

17.
18.
Abstract

Due to the location of manufacturing in north Hangzhou, many residential areas are close to trunk roads and factory areas. This potentially exposes citizens to pollution sources such as industrial emissions and vehicle exhaust. Because pollution by cadmium (Cd) is of great concern, an extensive survey was conducted in north Hangzhou city to study the current condition of Cd contamination and any resulting hazard. Environmental materials including water, bottom mud, urban green-land soil, street dust and moss were collected. Cd concentration and chemical partitioning in the samples were determined. The results indicate that all the media in north Hangzhou have elevated Cd concentrations, the Cd conten trend being: factory area >traffic area > residential area. The chemical partitioning results show that Cc in topsoil and street dust presents are mobile (9–61% Cd are bound in acetic acid extractable phase) which suggests a high ecological hazard potential. Environmental bioindicator moss samples were found to be loaded with Cd revealing high bioavailability of Cd in various media in north Hangzhou This confirms the possibility of Cd being a potential biohazard in this location.  相似文献   

19.
The effects of residential density were examined in the following study through a comparison of experiences of tenants living in 14-story apartment buildings and those in three-story walkups within the same low-income housing project. It was hypothesized that tenants in the high-rise buildings would come into contact with large numbers of others in the public spaces of their buildings. As these contacts exceeded residents' interaction capacity or ability to process relevant incoming social stimuli tenants would experience social overload. This experience would be manifested by tenants' perceptions of crowding in the building, feelings of less control, safety, and privacy in the immediate residential environment, problematic social relationships among tenants and alienation and dissatisfaction with the residential environment generally. These experiences were not expected to occur for tenants in the low-rise walkups. Interview data supported these hypotheses and revealed, in addition, that high-rise apartment residents were less socially active beyond their building and felt a greater sense of powerlessness in effecting management decisions. Correlational analyses provided further evidence of the vast differences between residents' experiences of the two building types.  相似文献   

20.
Building on a range of issues presented initially in The Ecological Indian: Myth and History , and debated subsequently in reviews and various papers, this article ranges widely in time to address traditional environmental knowledge, oral history, conservation and sustainability, and environmentalism in Indian Country. I also offer thoughts on the involvement of Native people in large-scale development, as well as comanagement schemes today and in the future.  相似文献   

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