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排序方式: 共有127条查询结果,搜索用时 15 毫秒
71.
72.
James E. M. Watson Emily S. Darling Oscar Venter Martine Maron Joe Walston Hugh P. Possingham Nigel Dudley Marc Hockings Megan Barnes Thomas M. Brooks 《Conservation biology》2016,30(2):243-248
Recognizing that protected areas (PAs) are essential for effective biodiversity conservation action, the Convention on Biological Diversity established ambitious PA targets as part of the 2020 Strategic Plan for Biodiversity. Under the strategic goal to “improve the status of biodiversity by safeguarding ecosystems, species, and genetic diversity,” Target 11 aims to put 17% of terrestrial and 10% of marine regions under PA status by 2020. Additionally and crucially, these areas are required to be of particular importance for biodiversity and ecosystem services, effectively and equitably managed, ecologically representative, and well‐connected and to include “other effective area‐based conservation measures” (OECMs). Whereas the area‐based targets are explicit and measurable, the lack of guidance for what constitutes important and representative; effective; and OECMs is affecting how nations are implementing the target. There is a real risk that Target 11 may be achieved in terms of area while failing the overall strategic goal for which it is established because the areas are poorly located, inadequately managed, or based on unjustifiable inclusion of OECMs. We argue that the conservation science community can help establish ecologically sensible PA targets to help prioritize important biodiversity areas and achieve ecological representation; identify clear, comparable performance metrics of ecological effectiveness so progress toward these targets can be assessed; and identify metrics and report on the contribution OECMs make toward the target. By providing ecologically sensible targets and new performance metrics for measuring the effectiveness of both PAs and OECMs, the science community can actively ensure that the achievement of the required area in Target 11 is not simply an end in itself but generates genuine benefits for biodiversity. 相似文献
73.
Myunghun Lee 《Resources Policy》2011,36(3):249-254
For industries in which where market prices of certain inputs are not available, measuring the degree of market power by using the markup over the marginal market cost may be inappropriate. With regard to the Korean iron and steel manufacturing industry, which is subject to environmental regulations, the calculation of the price of abatement capital is hindered by a lack of relevant data. To increase the reliability of market power markups, this paper estimates the restricted cost function in which abatement capital is assumed to be quasi-fixed at an optimal level and the supply relation. The degree of market power for the industry, measured as the ratio of the estimated market power markup to the supply price, was estimated to be 0.54 on average between 1982 and 2001. The results indicate that ignoring environmental regulations can overstate the degree of market power by approximately 12%. 相似文献
74.
提出一种全新的聚氨酯泡沫塑料中CFC-11总含量的测量方法.在密闭箱中将PUR硬泡破碎成粒径小于0.5 mm的细颗粒,使用GC/MS测量密闭箱中CFC-11浓度,得出破碎时释放出的CFC-11质量;将破碎的细颗粒用管式炉高温加热,使吸附于细颗粒中的CFC-11释放并用气样袋收集,使用GC/MS测量气样中CFC-11浓度,得出吸附于PUR硬泡固体中的CFC-11质量,最后将两者相加得出总含量. 相似文献
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Large, landscape-scale national monuments have long been controversial. It has been claimed that large monuments harm local economies by restricting growth of the grazing, timber, mining, and energy industries. Others have asserted that large monuments aid economic growth by reducing reliance on volatile commodity markets and fostering tourism growth. In this study, we use a synthetic control approach to measure the average causal effect of nine national monument designations on county-level per capita income. We find no evidence that monument designation affected per capita income in any of 20 counties hosting nine large (>50,000 acres) national monuments established under the Antiquities Act (six monuments) or by legislative action (three monuments). The broad economic claims of both advocates and critics of large national monuments have little empirical support. The absence of a designation effect for large national monuments is likely due to the attributes of federal land and the legal constraints under which it is managed. 相似文献
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79.
Dispersal propensity, reflecting one of the most decisive mammalian life history traits, has been suggested to vary heritably
and to locally adapt to prevailing dispersal conditions in wild house mouse populations. Because individual dispersal propensity
highly significantly covaries with the developmental timing of the onset of agonistic interactions between littermate brothers,
we used agonistic onset as an endophenotype to explore the potential genetic basis of dispersal-related behavioral variation
in male house mice. We found significant covariation of microsatellite marker compositions with the probability of fraternal
pairs to exhibit agonistic relationships before the age of 2 months. In particular, the presence of two alleles associated
with a serotonin transporter protein gene (Slc6a4) and a testosterone dehydrogenase gene (Cyp3a11), respectively, strongly
covaried with the probability of early agonistic onset. These results are congruent with recent findings of microsatellite
length polymorphisms marking regulatory variation of gene expression that is relevant for social behavior, including dispersal
propensity development, in other mammals. Genetic variability for ontogenetic timing of agonistic onset would be in agreement
with genotypic differentiation of the dispersive behavioral syndrome in natural populations that could lead to local adaptation. 相似文献
80.
Substance use and functional impairment among adolescents directly exposed to the 2001 World Trade Center attacks 总被引:1,自引:0,他引:1
Claude M. Chemtob Yoko Nomura Louis Josephson Richard E. Adams Lloyd Sederer 《Disasters》2009,33(3):337-352
The relationship between exposure to the World Trade Center (WTC) attacks, increased substance use, functional impairment and mental health service use, controlling for depression and post-traumatic stress disorder, was assessed through an in-school survey of directly exposed students (N = 1040) attending the five middle and five high schools nearest the WTC. The survey was conducted 18 months after the attacks. Students with one WTC exposure risk factor had a five-fold increase in substance use, while those with three or more exposure risks had a nearly 19-fold increase. Increased substance use was associated with impaired school work, school behaviour and grades. Students reporting increased substance use were nearly twice as likely to want help but were no more likely than asymptomatic students to receive services. Adolescents reporting increased substance use, without co-morbidity, were less likely to receive psychological services than others. Attention to the needs of substance-using adolescents exposed to disaster is needed. 相似文献