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1.
Brazil hosts the largest expanse of tropical ecosystems within protected areas (PAs), which shelter biodiversity and support traditional human populations. We assessed the vulnerability to climate change of 993 terrestrial and coastal-marine Brazilian PAs by combining indicators of climatic-change hazard with indicators of PA resilience (size, native vegetation cover, and probability of climate-driven vegetation transition). This combination of indicators allows the identification of broad climate-change adaptation pathways. Seventeen PAs (20,611 km2) were highly vulnerable and located mainly in the Atlantic Forest (7 PAs), Cerrado (6), and the Amazon (4). Two hundred fifty-eight PAs (756,569 km2), located primarily in Amazonia, had a medium vulnerability. In the Amazon and western Cerrado, the projected severe climatic change and probability of climate-driven vegetation transition drove vulnerability up, despite the generally good conservation status of PAs. Over 80% of PAs of high or moderate vulnerability are managed by indigenous populations. Hence, besides the potential risks to biodiversity, the traditional knowledge and livelihoods of the people inhabiting these PAs may be threatened. In at least 870 PAs, primarily in the Atlantic Forest and Amazon, adaptation could happen with little or no intervention due to low climate-change hazard, high resilience status, or both. At least 20 PAs in the Atlantic Forest, Cerrado, and Amazonia should be targeted for stronger interventions (e.g., improvement of ecological connectivity), given their low resilience status. Despite being a first attempt to link vulnerability and adaptation in Brazilian PAs, we suggest that some of the PAs identified as highly or moderately vulnerable should be prioritized for testing potential adaptation strategies in the near future.  相似文献   
2.
In an attempt to identify the ionic imbalance, hydrogen carbonate, HCO3 (bicarbonate), was determined together with the commonly determined nine major ions because the imbalance was frequently encountered in the chemical analysis of samples with high pHs. Titration method was applied for the determination of the samples with pH higher than 5.6. These samples amounted to 102 of the 1536 samples collected in Hokkaido, Northern Japan, from April 1998 to December 2002. Of the 102 samples, 74 (Group A) showed an acceptable ion balance without including HCO3. In the other 28 (Group B), however, inclusion of HCO3 successfully improved the ion balance. These results suggested that hydrogen carbonate was a potential candidate for explaining the imbalance. The hydrogen carbonate concentrations showed a strong correlation with the corresponding non-sea salt calcium (nss-Ca2+) concentrations, which implied that hydrogen carbonate was derived from calcium carbonate particles incorporated into falling raindrops or cloud droplets. For Group A, the relationship between hydrogen carbonate and the nss-calcium ion concentration was very similar to that for commonly suspended particles in Hokkaido. On the other hand, Group B exhibited a stronger but significantly different correlation. To the samples of Group B, a back-trajectory analysis was applied to demonstrate that the samples were associated with aerosol travelling from Northern China or Mongolia, which indicated that alkaline aerosol affected the chemistry. In consideration of these findings, the current standard of the ion balance should be critically reviewed for modification in regard to the contribution of hydrogen carbonate not only in source areas but also in receptor areas of alkaline aerosol.  相似文献   
3.
Eight pharmaceuticals were selected on the basis of their domestic consumption in Japan, the excretion ratio of the parent compound and the frequency of detection in the aquatic environment or wastewater treatment plant effluent. Toxicity tests on these pharmaceuticals were conducted using Japanese medaka (Oryzias latipes), daphnia (Daphnia magna), and green algae (Psuedokirchneriella subcapitata). Predicted no effect concentration (PNEC) was calculated using lethal or effect concentration 50 (LC50 or EC50) values and no effect concentration (NOEC) obtained in the toxicity tests for these compounds. Predicted environmental concentration (PEC) was also calculated from annual consumption, the excretion rate of the parent compound, and removal rate in the preliminary batch activated sludge treatment performed in this study. Maximum concentrations found in the aquatic environment or sewage effluent in Japan or foreign countries were also used for another calculation of PEC. Initial risk assessment on the selected pharmaceuticals was performed using the PEC/PNEC ratio. The results of initial risk assessment on the eight selected pharmaceuticals suggest neither urgent nor severe concern for the ecological risk of these compounds, but further study needs to be conducted using chronic toxicity tests, including reproduction inhibition and endocrine disruption assessments.  相似文献   
4.
5.
土壤中多环芳烃化合物的生物降解及监测   总被引:2,自引:3,他引:2  
在实验室模拟条件下,研究芳香化合物菲污染土壤中的生物降解作用。结果表明,转基因工程菌对土壤中菲的生物降解有很好促进效果,在30d内约有50%的菲被降解。同时利用分子生物学技术对污染环境中转基因工程菌进行了追踪监测,发现添加菌的数量随时间的推移逐渐减少。  相似文献   
6.
Steam gasification of dehydrochlorinated poly(vinyl chloride) (PVC) or activated carbon was carried out in the presence of various alkali compounds at 3.0 MPa and 560°C–660°C in a batch reactor or in a semi-batch reactor with a flow of nitrogen and steam. Hydrogen and sodium carbonate were the main products, and methane and carbon dioxide were the minor products. Yields of hydrogen were high in the presence of sodium hydroxide and potassium hydroxide. The acceleration effect of the alkali compounds on the gasification reaction was as follows: KOH > NaOH > Ca(OH)2 > Na2CO3. The rate of gasification increased with increasing partial steam pressure and NaOH/C molar ratio. However, the rate became saturated at a molar ratio of NaOH/C greater than 2.0.  相似文献   
7.
Organic peroxides (POs) have been widely used in chemical industries as initiators of polymerization, hardening or bridge formation agents, and they are known for its self-reactive and also mixing hazard characteristics when mixed with other chemicals such as acids and alkalis. It is the purpose of this investigation to propose a simple but useful evaluation flow of mixing hazards of POs with other chemicals using conventional experimental techniques such as a glass test tube test, Dewar vessel test and DSC is proposed. 7 kinds of POs (DEPD, THP, TBEH, TBTC, MEKPO, DTBP, THHP) were mixed with sulfuric acids with various concentration, sodium hydroxide solutions, -iron(III) oxide and acrylonitrile (AN).

Based on the proposed evaluation flow the testing results were classified into 4 ranks due to the hazard criteria. Futhermore DEPD/acrylonitrile mixtures were investigated in more detail and the influences of the mixing ratio and the stirring speed were discussed.  相似文献   

8.

The mass food poisoning incident yusho occurred in Japan in 1968. It was caused by the ingestion of rice bran oil contaminated with polychlorinated biphenyls and various dioxins and dioxin-like compounds including polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDFs). Notably, PCDFs were found to contribute to approximately 65% of the total toxicity equivalent in the blood of yusho patients. Lipophilic dioxins are retained in the body for a longer period than previously estimated. Victims suffered from characteristic skin manifestations associated with non-specific systemic symptoms, neurological symptoms, and respiratory symptoms. The severe symptoms seen in the initial phase subsequently faded, but recently, improvements have scarcely been observed. The Yusho Group has been researching treatments for this condition. Several clinical trials with chelating agents or dietary fibers aimed at accelerating the excretion of compounds. While some treatments increased dioxin excretion, none provided satisfactory symptom relief. Concurrently, various phytochemicals and herbal extracts have been found to possess biological activities that suppress dioxin-induced toxicity via aryl hydrocarbon receptor or activate the antioxidant nuclear factor-erythroid 2-related factor-2 (NRF2) signal pathway, making them promising therapeutic candidates. Here, we summarize the current status of yusho and findings of clinical trials for yusho patients and discuss the treatment prospects.

  相似文献   
9.
It is known that aeration reduces rapidly the concentration of organic matter in leachate. However, the oxygen flow rate required to attain a certain reaction rate of organic matter should be carefully estimated. In this study, using the oxygen ratio (the ratio of oxygen flow rate by aeration to oxygen consumption rate of waste layer) as a parameter, the reaction rate of organic matter in leachate from landfilled incineration ash and incombustible waste upon aeration was evaluated. Total organic carbon (TOC) in the leachate was reduced rapidly when the oxygen ratio was high. The decomposition rate exceeded the elution rate of TOC in the leachate from the waste layer for several days when the oxygen ratio was above 102. The results indicate that the oxygen ratio can be used as a parameter for the aeration operation in actual landfill sites, to rapidly stabilize organic matter in leachate.  相似文献   
10.
Loss of zooxanthellae (dinoflagellate Symbiodinium) from corals will sometimes lead to mass mortality of corals. To detect and quantify Symbiodinium released from corals, we developed a zooxanthellae “trap” and a quantitative PCR (qPCR) system with Symbiodinium clades A–F-specific primer sets. The trap was attached to a branch or the surface of several wild stony corals, and the water samples within the traps, including released Symbiodinium, were subjected to qPCR. All tested corals released clade C Symbiodinium at estimates of ~5,900 cells h−1 cm−2 of coral surface. Although all tested Pocillopora eydouxi harboured both clades C and D, some of these colonies released only clade C or released a lesser amount of clade D than that in the tissues. Our Symbiodinium quantification system revealed that wild hermatypic corals constantly release Symbiodinium to the environment. Our result suggests that some corals may discharge certain clades of Symbiodinium alternatively.  相似文献   
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