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1.
The future of human health and that of all other species depends on the viability and sustainability of a host of environments and ecosystems. Human behaviours have profound effects (both positive and negative) on such ecosystems. Despite the obviousness of these statements, there remains a lack of clarity around the mechanisms for altering specific behaviours related to sustainability and their impact on environments. This paper offers a conceptual framework for identifying relations between human behaviour and ecosystem health and sustainability. We also discuss strategies for changing target behaviours in the context of a programme or policy planning. Finally, we draw on research that applies this adaptation to a small island community near Vancouver, Canada.  相似文献   
2.
Tillage erosion and its effect on soil properties and crop yield in Denmark   总被引:1,自引:0,他引:1  
Tillage erosion had been identified as a major process of soil redistribution on sloping arable land. The objectives of our study were to investigate the extent of tillage erosion and its effect on soil quality and productivity under Danish conditions. Soil samples were collected to a 0.45-m depth on a regular grid from a 1.9-ha site and analyzed for 137Cs inventories, as a measure of soil redistribution, soil texture, soil organic carbon (SOC) contents, and phosphorus (P) contents. Grain yield was determined at the same sampling points. Substantial soil redistribution had occurred during the past decades, mainly due to tillage. Average tillage erosion rates of 2.7 kg m(-2) yr(-1) occurred on the shoulderslopes, while deposition amounted to 1.2 kg m(-2) yr(-1) on foot- and toeslopes. The pattern of soil redistribution could not be explained by water erosion. Soil organic carbon and P contents in soil profiles increased from the shoulder- toward the toeslopes. Tillage translocation rates were strongly correlated with SOC contents, A-horizon depth, and P contents. Thus, tillage erosion had led to truncated soils on shoulderslopes and deep, colluvial soils on the foot- and toeslopes, substantially affecting within-field variability of soil properties. We concluded that tillage erosion has important implications for SOC dynamics on hummocky land and increases the risk for nutrient losses by overland flow and leaching. Despite the occurrence of deep soils across the study area, evidence suggested that crop productivity was affected by tillage-induced soil redistribution. However, tillage erosion effects on crop yield were confounded by topography-yield relationships.  相似文献   
3.
Investigators have long been interested in the natural phenomenon of fetal and placental cell trafficking into the maternal circulation. The scarcity of these circulating cells makes their detection and isolation technically challenging. However, as a DNA source of fetal origin not mixed with maternal DNA, they have the potential of considerable benefit over circulating cell-free DNA-based noninvasive prenatal genetic testing (NIPT). Endocervical trophoblasts, which are less rare but more challenging to recover are also being investigated as an approach for cell-based NIPT. We review published studies from around the world describing both forms of cell-based NIPT and highlight the different approaches’ advantages and drawbacks. We also offer guidance for developing a sound cell-based NIPT protocol.  相似文献   
4.
5.
Abstract: Illegal exploitation threatens the survival of many species, and anti-poaching legislation ("protection on paper") does not protect species. State enforcement is needed to support and supplement the formal status of endangered species, but state enforcement can be a source of instability leading to the demise of species if ad hoc rules are followed blindly. We demonstrate this with a model of poaching, wildlife, and government wildlife enforcement, but our findings apply more generally. Crucial assumptions of the dynamic model are that both poaching and enforcement effort increase or decrease whenever poaching effort and enforcement are relatively profitable or unprofitable activities, respectively. We found that multiple steady states may characterize the system's equilibrium. Depending on initial populations, the initial extent of state involvement, and random events, animal populations may be severely depleted or unexpectedly built up during transition phases. Our findings highlight the importance of history and luck in protecting endangered species.  相似文献   
6.
Since 1994 UNIDO and UNEP cooperate in a Programme to establish National Cleaner Production Centres (NCPCs) as a mechanism for delivery of Cleaner Production (CP) services to businesses, governments and other organisations. In 2007, 38 NCPCs were operational in 37 developing and transition countries. While initially set up in near-identical ways in each country, over time NCPCs evolved in response to both programme-internal and country-level factors. The resulting diversity among NCPCs is described and analysed here. Differentiation and specialisation had occurred in service areas or topics both within and between NCPCs, however without a clear strategy for integration and synergy. NCPCs were becoming part of expanding networks of business services providers nationally forcing some to focus on audit and training services (tier 1), and others on specialist services in CP technology and/or policy (tier 2) and/or networking services (tier 3). All NCPCs were on a trajectory from a project management organisation to a nationally-owned entity. The different management requirements were not proactively managed and technical aspects of CP service delivery overshadowed institutional and governance aspects of establishing and operating the NCPC institution. Differences in service delivery methods between NCPCs are most evident in three service areas: CP assessments; policy advice; and transfer of Environmentally Sound Technologies. It is argued here that understanding root causes and benefits of this presently-observed differentiation, could lay the foundation for capturing and advancing best practice CP concepts, methods and policies. This in turn would enable strategic planning for customised interventions and support at the national level.  相似文献   
7.
A landfill operated in Ste. Sophie, Québec, Canada was instrumented to better understand the waste stabilization process in northern climates. Instrument bundles were placed within the waste to monitor temperature, settlement, oxygen, moisture content, total load, mounding of leachate and electrical conductivity. A finite element model was developed to simulate the heat budget for the first waste lift placed in the winter months and was calibrated using the first 10.5 months of collected temperature data. The calibrated model was then used to complete a sensitivity analysis for the various parameters that impact the heat budget. The results of the analysis indicated that the heat required for phase change to thaw the liquid fraction within frozen waste had a significant impact on the heat budget causing sections of waste to remain frozen throughout the simulation period. This was supported by the data collected to date at Ste. Sophie and by other researchers indicating that frozen waste placed during the winter months can remain frozen for periods in access of 1.5 years.  相似文献   
8.
Firewood is the basic fuel source in rural Bolivia. A study was conducted in an Andean village of subsistence farmers to investigate human impact on wild firewood species. A total of 114 different fuel species was inventoried during fieldtrips and transect sampling. Specific data on abundance and growth height of wild firewood species were collected in thirty-six transects of 50 ×2 m2. Information on fuel uses of plants was obtained from 13 local Quechua key participants. To appraise the impact of fuel harvest, the extraction impact value (EIV) index was developed. This index takes into account local participants?? appreciation of (1) decreasing plant abundance; (2) regeneration capacity of plants; (3) impact of root harvesting; and (4) quality of firewood. Results suggest that several (sub-)woody plant species are negatively affected by firewood harvesting. We found that anthropogenic pressure, expressed as EIV, covaried with density of firewood species, which could entail higher human pressure on more abundant and/or more accessible species. The apparent negative impact of anthropogenic pressure on populations of wild fuel species is corroborated by our finding that, in addition to altitude, several anthropogenic variables (i.e. site accessibility, cultivation of exotics and burning practices) explain part of the variation in height of firewood species in the surroundings of Apillapampa.  相似文献   
9.
创刊于1972年12月的《文教资料简报》是由南京师范学院(1984年易名为南京师范大学)内部编印的资料性月刊,主要目的是为文科教研服务。本文回顾该刊从创办至拥有"统一刊号"、从非正式出版物至成为正式出版物的历史沿革,具体观照该刊的编辑理念,总结该刊的内容特色、文献价值及经验启示。  相似文献   
10.
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