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91.
Conservation practice has demonstrated an increasing desire for accountability of actions, particularly with respect to effectiveness, efficiency, and impact to clearly identified objectives. This has been accompanied by increased attention to achieving adaptive management. In 2002, practitioners representing several prominent conservation nongovernmental organizations (NGOs) launched a community of practice called the Conservation Measures Partnership (CMP). The partnership CMP has worked to establish standards of conservation practice to improve accountability of conservation actions through adaptive management. The focal organizing framework for CMP has been the Open Standards for the Practice of Conservation (OS). We evaluated, through an online survey and personal interviews, the first decade of CMP and the OS. The CMP has garnered a positive reputation among agencies, NGOs, and funders and has succeeded in developing a large user base of the OS. However, CMP has not fully achieved its goal of making the OS standard operating procedure for the largest NGOs (e.g., The Nature Conservancy, World Wildlife Fund), despite it being widely used within these organizations. This lack of institutionalization is attributable to multiple causes, including an increase in the number of partially overlapping decision‐support frameworks and challenges achieving full‐cycle adaptive management. Users strongly believed the OS fosters better conservation practice and highly valued the OS for improving their practice. A primary objective of the OS is to assist practitioners to achieve full‐cycle adaptive management to better integrate learning into improving the effectiveness and efficiency of actions. However, most practitioners had not yet achieved cycle completion for their projects. To improve the effectiveness of CMP, OS, and conservation practice in general, we recommend collaborative efforts among the proponents of multiple decision‐support frameworks to foster strong institutional adoption of a common set of adaptive‐management standards for conservation accountability.  相似文献   
92.
This paper uses unique data on daily air pollution concentrations over the period 2001–2010 to test for manipulation in self-reported data by Chinese cities. First, we employ a discontinuity test to detect evidence consistent with data manipulation. Then, we propose a panel matching approach to identify the conditions under which irregularities may occur. We find that about 50% of cities reported dubious PM10 pollution levels that led to a discontinuity at the cut-off. Suspicious data reporting tends to occur on days when the anomaly is least detectable. Our findings indicate that the official daily air pollution data are not well behaved, which provides suggestive evidence of manipulation.  相似文献   
93.
Economists are increasingly interested in causally interpretable estimates of environmental health externalities, particularly on infant health. This paper focuses on a specific case by investigating microcystin, a toxin produced by freshwater blue-green algal blooms. We exploit a natural experiment caused by a zebra mussel die-off in a large lake located in the state of Michigan, USA to identify changes in microcystin-related infant outcomes surrounding the lake. Using both the synthetic control method and a difference-in-differences strategy, we find that instances of low birth weight around the lake fell by 1.4 percentage points after lake water quality improved. Along the intensive margin, birth weight and length of gestation increased by 17.1 g and 0.47 weeks, respectively. Improvements to low birth weight result in $768,500 in average annual hospitalization cost savings. Many robustness and falsification tests are performed including using both annual and monthly data and accounting for possible weather confounders and seasonality. Results suggest that microcystin can affect infant health at levels below current water advisory guidelines.  相似文献   
94.
Cd胁迫下超富集植物圆锥南芥抗氧化机理   总被引:12,自引:2,他引:10  
采用土培的方法研究了不同Cd2+添加量(0、10、20、40、80、160、240mg.kg-1)对多金属超富集植物圆锥南芥(Arabis paniculata Franch)抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶POD、抗坏血酸过氧化物酶CAT、过氧化物酶APX)活性、非酶物质(巯基SH、谷胱甘肽GSH、植物络合素PCs)含量以及生物量、叶绿素、丙二醛(MDA)、半胱氨酸(Cysteine)、脯氨酸(Proline)含量的影响.结果表明,随着Cd添加量的增加,圆锥南芥的生物量、Cd含量、富集系数、转运系数呈增加趋势,SOD活性、叶绿素含量呈下降趋势.POD、CAT、APX活性以及MDA含量均呈先升高后降低的变化趋势.圆锥南芥叶片中SH、GSH、PCs含量随Cd添加量的增加而增加,当Cd添加量为240mg.kg-1时,SH、GSH、PCs含量分别比对照提高了92.7%、70.2%、143.4%,表明SH、GSH、PCs在解毒Cd毒害中起着重要作用.  相似文献   
95.
The solid acid catalyst, N–F codoped TiO2/SiO2 composite oxide was prepared by a sol–gel method using NH4F as nitrogen and fluorine source. The prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV–Visible diffuse reflectance spectroscopy (UV–Vis), ammonia adsorption and temperature-programmed desorption (NH3-TPD), in situ Fourier transform infrared spectroscopy (FT-IR) and N2 physical adsorption isotherm. The photocatalytic activity of the catalyst for acrylonitrile degradation was investigated under simulant solar irradiation. The results showed that strong Lewis and Brønsted acid sites appear on the surface of the sample after N–F doping. Systematic investigation showed that the highest photocatalytic activity for acrylonitrile degradation was obtained for samples calcined at 450°C with molar ratio (NH4F to Ti) of 0.8. The degradation ratio of 71.5% was achieved with the prepared catalyst after 6-min irradiation, demonstrating the effectiveness of photocatalytic degradation of acrylonitrile with N–F codoped TiO2/SiO2 composite oxide. The photocatalyst is promising for application under solar light irradiation. Moreover, the intermediates generated after irradiation were verified by gas chromatography–mass spectrometry (GC–MS) analysis and UV–Vis spectroscopy to be simple organic acids with lower toxicity, and the degradation pathway was also proposed for acrylonitrile degradation with the prepared catalyst.  相似文献   
96.
本文对新疆核试验场周围9个地区和3个对照区近23种主要食品中的钚含量进行了分折测定。结果表明,调查区和对照区同类食品中钚含量无显著性差异,由食入钚所致调查区和对照区居民的有效待积剂量当量分别为7.65μSV和7.22μSV,此附加剂量不会对人体健康产生不良影响。在相对应的耕作土壤中钚向植物的转移系数在0.2%~5%之间,转移系数是叶菜类>根茎类>果实类。由积分沉积密度和该地区居民膳食中钚的摄入量估箅出P23值,调查区为0.70Bq/m2,对照区为0.72Bq/m2,这一数值与UNSCEAR 1982年报告书给出的P23值基本相符。   相似文献   
97.
研究了乌鲁木齐市不同功能区表层土壤中水溶性氟(Ws-F)的含量。结果表明:土壤Ws-F平均含量为5.36 mg/kg,变幅为1.55~12.53 mg/kg。其中,工业区(7.13 mg/kg)〉绿化区(5.73 mg/kg)〉商业区(5.71 mg/kg)〉居民区(4.93 mg/kg)〉农业区(3.08 mg/kg)。乌鲁木齐市土壤中Ws-F含量已高于我国地氟病发生区表层土壤Ws-F的平均值(2.50 mg/kg),应引起有关部门的高度重视。  相似文献   
98.
Atmospheric concentrations and deposition fluxes of PCDD/F and PCB have been evaluated over a 1-year period in a Mediterranean coastal lagoon (Etang de Thau, France). Indicative PBDE air concentrations in the hot season are also reported in this work. ∑2,3,7,8-PCDD/Fs and ∑18PCBs (gas + particulate) air concentrations ranged from 67 to 1700 fg m−3 and from 13 to 95 pg m−3, respectively whereas ∑8PBDEs (gas + particulate) summer time levels varied from 158 to 230 pg m−3. The PCDD/F and PCB atmospheric occurrence over Thau lagoon and subsequent inputs to the surface waters are determined by an assemble of factors, being the seasonality of atmospheric concentration, the air mass origin and meteorological conditions important drivers. Total (wet + dry) ∑2,3,7,8-PCDD/Fs and ∑18PCBs deposition fluxes to Thau Lagoon waters are 117 and 715 pg m−2 d−1, respectively.  相似文献   
99.
Denys S  Gombert D  Tack K 《Chemosphere》2012,88(7):806-812
Fires might be the source of persistent organic pollutants (POPs) such as dioxins, furans (PCDD/Fs) and/or polychlorobiphenyls (PCBs) in the environment. In the perspective of defining legal responsibilities a thorough characterization of the impact of such an event should be carried out. However, such characterization is not easy as the environment integrates both local and diffuse sources of such molecules. Thus, a combined approach, which includes gathering field surveys, modeling and laboratory experiments, should be conducted. The objective of this work is to illustrate different approaches to give sufficient insight to determine the actual impact of wood fire on the environment. The work was carried out at the vicinity of a burnt down parcel. The fired material was a mixture of wood and PCB-contaminated soils as the site was a former pyralene-disposal site. Modeling, soil and lichen sampling and experimental combustion were carried out to delineate the contamination for each chemical and to define the area within the fire that was responsible for the environmental contamination. Concentrations of PCDD/F and PCBs were very high on the burnt plot. The combined approach determined that the furans were the predominant compounds in the smoke emitted by the fire. Based on this tracer, it was possible to demonstrate that in terms of environmental contamination of PCDD/F, the impact of the fire was restricted to a 2 km radius from the burnt down plot. For PCBs, no specific tracer was identified. In this case, the delineation of the impact could only be empirical, based on the total concentration of the chemicals.  相似文献   
100.
Holt E  Weber R  Stevenson G  Gaus C 《Chemosphere》2012,88(3):364-370
Chlorinated pesticides can contain impurities of dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and their precursors, as a result of various manufacturing processes and conditions. As precursor formation of PCDD/Fs can also be mediated by ultraviolet light (UV), this study investigated whether PCDD/Fs are formed when currently used pesticides are exposed to natural sunlight. Formulations containing pentachloronitrobenzene (PCNB; n = 2) and 2,4-dichlorophenoxyacetic acid (2,4-D; n = 1) were exposed to sunlight in quartz tubes, and the concentration of 93 PCDD/F congeners were monitored over time. Considerable formation of PCDD/Fs was observed in both PCNB formulations (by up to 5600%, to a maximum concentration of 57 000 μg ∑PCDD/F kg−1) as well as the 2,4-D formulation (by 3000%, to 140 μg ∑PCDD/F kg−1). TEQ also increased by up to 980%, to a maximum concentration of 28 μg kg−1 in PCNB, but did not change in the 2,4-D formulation. Assuming similar yields as observed in the present study as a worst case scenario the use of PCNB in Australia may result in the formation of 155 g TEQ annum−1, contributed primarily by OCDD formation. This warrants detailed evaluations on the contemporary release of PCDD/Fs to the environment after the use of pesticides. Changes in congener profiles (including the ratio of PCDDs to PCDFs (DF ratio)) suggest that pesticide sources of PCDD/Fs after sunlight exposure may not be recognized based on matching source fingerprints established from manufacturing impurities. These changes also provide preliminary insights into the possible formation routes and types of precursors involved.  相似文献   
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