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971.
Eric Allemano 《Natural resources forum》2008,32(2):142-151
The article seeks to sensitize the development community, particularly outside the education sector, about the issues surrounding education as a vehicle for promoting sustainable development in an AIDS environment in Africa. By illustrating how the epidemic impacts education sector staff as well as parents and students at all levels, the article intends to suggest how national authorities, NGOs and donor agencies can work out strategies to enhance the role of education in promoting sustainable development in Africa. Analysis will demonstrate how the AIDS epidemic weakens the education sector, particularly in countries with a generalized epidemic (defined as more than 3% of the adult population being HIV‐positive), undermining the sector's ability to contribute to general literacy and sustainable development. The article will demonstrate that HIV and AIDS is still not fully accepted as an educational issue, which has hampered efforts to deal with its ravages in the educational sector. The need for holistic policy frameworks for supporting teachers and administrators living with HIV and AIDS will be discussed as well as how changes in curriculum and better relations with the community are important in addressing the needs of students. The article will highlight options for developing innovative responses to HIV and AIDS in African education, showing how different forms of education can serve as vehicles for responding to the challenges of the epidemic. The examples emphasize the importance of learner‐centered instruction and partnerships with the health sector and other resources needed in an AIDS‐affected environment. Key messages of the article are that the HIV and AIDS epidemic is a multi‐sectoral problem and that responding to it effectively in the education sector requires coherent responses that address the needs of learners and instructors, including those who are personally affected or infected by HIV and AIDS. Adapting the Education for Sustainable Development initiative to address the challenges posed by the epidemic must be supported by policy development, leadership and advocacy. Diverse partnerships are essential, as the education sector alone cannot deal with the challenge of HIV and AIDS to sustainable development. 相似文献
972.
973.
Integrated landscape planning and remuneration of agri-environmental services. Results of a case study in the Fuhrberg region of Germany 总被引:1,自引:0,他引:1
Until now, existing remuneration of environmental services has not sufficiently supported the goals of spending money more effectively on the environment and of motivating farmers. Only a small share of the budgets for agriculture in the EU, as well as in US and other countries, is available for buying environmental goods and services beyond the level of good farming practice (GFP). This combined with the insufficient targeting of compensation payments to areas where special measures are needed leads to an unsatisfactorily low impact of agri-environment measures compared to other driving forces that stimulate the intensification of farming. The goal of this paper is to propose a management concept that enhances the ecological and cost efficiency of agri-environment measures. Components of the concept are a comprehensive environmental information base with prioritised goals and targets (available in Germany from landscape planning) and new remuneration models, which complement conventional compensation payments that are based upon predetermined measures and cost. Comprehensive landscape planning locates and prioritises areas which require environmental action. It contains the information that authorities need to prioritise funding for environmental services and direct measures to sites which need environmental services beyond the level of GFP.Also appropriate remuneration models, which can enhance the cost efficiency of public spending and the motivation of the farmers, can be applied on the base of landscape planning.Testing of the planning methodology and of one of the remuneration models (success-oriented remuneration) in a case study area (“Fuhrberger Feld” north of Hanover, Germany) demonstrated the usability of the concept and led to proposals for future development of the methodology and its application in combination with other approaches. 相似文献
974.
975.
Background, Aim and Scope
Metal ions generally share the ability/tendency of interacting with biological material by forming complexes, except possibly for the heavy alkali metals K, Rb and Cs. This is unrelated to the metals being either essential for sustaining life and its reproduction, apparently insignificant for biology, although perhaps undergoing bioconcentration or even being outright toxic, even at low admission levels. Yet, those different kinds of metal-biomass interactions should in some way depend on properties describing coordination chemistries of these very metals. Nevertheless, both ubiquitously essential metals and others sometimes used in biology should share these properties in numeric terms, since it can be anticipated that they will be distinguished from nonessential and/or toxic ones. These features noted above include bioconcentration, the involvement of metal ions such as Zn, Mg, Cu, Fe, etc. in biocatalysis as crucial components of metalloenzymes and the introduction of a certain set of essential metals common to (almost) all living beings (K, Mg, Mo, Mn, Fe, Cu and Zn), which occurred probably very early in biological evolution by ‘natural selection of the chemical elements’ (more exactly speaking, of the metallomes).Materials and Methods
The approach is semiempirical and consists of three consecutive steps: 1) derivation of a regression equation which links complex stability data of different complexes containing the same metal ion to electrochemical data pertinent to the (replaced) ligands, thus describing properties of metal ions in complexes, 2) a graphical representation of the properties-two typical numbers c and x for each metal ion-in some map across the c/x-space, which additionally contains information about biological functions of these metal ions, i.e. whether they are essential in general (e.g. Mg, Mn, Zn) or, for a few organisms of various kinds (e.g. Cd, V), not essential (e.g. rare earth element ions) or even generally highly toxic (Hg, U). It is hypothesized that, if coordination properties of metals control their biological ‘feasibility’ in some way, this should show up in the mappings (one each for mono and bidentate-bonding ligands). 3) eventually, the regression equation produced in step 1) is inverted to calculate complex stabilities pertinent to biological systems: 3a) complex stabilities are mapped for ligands delivered to soil (-water) by green plants (e.g. citrate, malate) and fungi and, compared to their unlike selectivities and demands of metal use (photosynthesis taking place or not), 3b) the evolution of the metallome during late chemical evolution is reconstructed.Results
These maps show some ‘window of essentiality’, a small, contrived range/area of c and x parameters in which essential metal ions gather almost exclusively. c and x thus control the possibility of a metal ion becoming essential by their influencing details of metal-substrate or (in cases of catalytic activities) metal-product interactions. Exceptions are not known to be involved in biocatalysis anyhow.Discussion
Effects of ligands secreted, e.g. from tree roots or agaric mycelia to the soil on the respective modes (selectivities) of metal bioconcentration can be calculated by the equation giving complex stability constants, with obvious ramifications for a thorough, systematic interpretation of biomonitoring data. Eventually, alterations of C, N and P-compounds during chemical evolution are investigated — which converted CH4 or CO2, N2 and other non-ligands to amino acids, etc., for example, with the latter behaving as efficient chelating ligands: Did they cause metal ions to accumulate in what was going to become biological matter and was there a selectivity, a positive bias in favour of nowessential metals (see above) in this process? Though there was no complete selectivity of this kind, neither a RNA world in which early ribozymes effected most of biocatalysis, nor a paleoatmosphere containing substantial amounts of CO could have paved the way to the present biochemistry and metallomes.Conclusions
This way of reasoning provides a causal account for abundance distributions described earlier in the Biological System of Elements (BSE; Markert 1994, Fränzle &; Markert 2000, 2002). There is a pronounced change from chemical evolution, where but few transformations depended on metal ion catalysis to biology.Recommendations and Perspectives
The application of this numerical approach can be used for modified, weighted evaluation of biomonitoring analytical data, likewise for the prediction of bioconcentration hazards due to a manifold of metal ions, including organometallic ones. This is relevant in ecotoxicology and biomonitoring. In combining apoproteins or peptides synthesized from scratch for purposes of catalysing certain transformations, the map and numerical approaches might prove useful for the selection of central ions which are even more efficient than the ‘natural’ ones, like for Co2+ in many Zn enzymes.976.
Quevauviller P 《Environmental science and pollution research international》2007,14(5):297-307
Science-policy integration is one of the many complex challenges that scientific and policy-making communities are facing.
It involves knowledge sharing and exchanges among a wide range of disciplines and actors. In many instances, the lack of proper
communication and of a coordination mechanism leads to research outputs not being used or simply known by policy-makers, and
to policy research needs not being communicated to the scientific communities in a timely fashion. This paper discusses the
integration of scientific and technological progress into the policy-making and implementation process, with emphasis on water
policies. It highlights the need and complexity of developing a knowledge-based approach which would enable to lead to an
operational science-policy interface linked to WISE (Water Information System for Europe), including the newly developed WISERTD
webportal ().
The views expressed in this paper are purely those of the author and do not in any circumstances reflect an official position
of the European Commission. 相似文献
977.
Healthy watersheds provide valuable services to society, including the supply and purification of fresh water. Because these natural ecosystem services lie outside the traditional domain of commercial markets, they are undervalued and underprotected. With population and development pressures leading to the rapid modification of watershed lands, valuable hydrological services are being lost, which poses risks to the quality and cost of drinking water and the reliability of water supplies. Increasing the scale and scope of programmes to protect hydrological services requires policies that harmonize land uses in watersheds with the provision of these important natural services. This article summarizes key attributes of hydrological services and their economic benefits; presents a spectrum of institutional mechanisms for safeguarding those services; discusses programmes in Quito (Ecuador), Costa Rica and New York City; and offers some lessons learned and recommendations for achieving higher levels of watershed protection. 相似文献
978.
Michael A.Levi 《世界环境》2005,(2):13-14
Is the US nuclear arsenal sufficient to address today‘s security challenges? The Pentagon apparently thinks not. A new report from its Defense Science Board (DSB) argues that ““““nuclear weapons are needed that produce much lower collateral damage‘. It lends support to proposals to build new nuclear weapons for attacking underground facilities. To a point, such ‘bunker busters‘ are nothing new-the B-53 bomb, first deployed in the early 1960s, can destroy underground targets, although it creates lethal radioactive fallout that covers hundreds of thousands of square kilometres. 相似文献
979.
生态系统服务功能价值评估方法综述 总被引:31,自引:0,他引:31
本文在回顾生态系统服务功能价值分类和评估方法的基础上,得出目前我国的生态系统服务功能价值评估方法正处于从学习、模仿向渐进成熟阶段过渡,通过对生态系统服务功能的价值评估方法的对比分析,得出生态系统功能价值评估方法选择应根据先直接市场法、再替代市场法、最后模拟市场法的基本原则进行. 相似文献
980.
在地理信息系统(GIS)与遥感(RS)技术的支持下,选择多种定量指数对滇西北高原典型湿地区———碧塔海自然保护区进行了空间格局分析研究。通过分析,揭示了研究区景观空间格局的结构和特征及受扰程度,为研究区的湿地资源利用与保护提供了科学依据和决策支持。 相似文献