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61.
The role of exogenous spermine (0.25 mM Spm, a type of polyamine (PA) in reducing Cd uptake and alleviating Cd toxicity (containing 1 and 1.5 mM CdCl2 in the growing media) effects was studied in the mung bean (Vigna radiata L. cv. BARI Mung-2) plant. Exogenously applied Spm reduced Cd content, accumulation, and translocation in different plant parts. Increasing phytochelatin content, exogenous Spm reduced Cd accumulation and translocation. Spm application reduced the Cd-induced oxidative damage which was reflected from the reduction of H2O2 content, O2 ?– generation rate, lipoxygenase (LOX) activity, and lipid peroxidation level and also reflected from the reduction of spots of H2O2 and O2 ?– from mung bean leaves (compared to control treatment). Spm pretreatment increased non-enzymatic antioxidant contents (ascorbate, AsA, and glutathione, GSH) and activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and glutathione reductase (GR) which reduced oxidative stress. The cytotoxicity of methylglyoxal (MG) is also reduced by exogenous Spm because it enhanced glyoxalase system enzymes and components. Through osmoregulation, Spm maintained a better water status of Cd-affected mung bean seedlings. Spm prevented the chl damage and increased its content. Exogenous Spm also modulated the endogenous free PAs level which might have the roles in improving physiological processes including antioxidant capacity, osmoregulation, and Cd and MG detoxification capacity. The overall Spm-induced tolerance of mung bean seedlings to Cd toxicity was reflected through improved growth of mung bean seedlings.  相似文献   
62.
There are increasing attempts to define the measures of ‘dangerous anthropogenic inference with the climate system’ in context of Article 2 of the Framework Convention on Climate Change, due to its linkage to goals for stabilizing greenhouse gas concentrations. The criteria for identifying dangerous anthropogenic interference may be characterized in terms of the consequences of climate change. In this study, we use the water stress index (WSI) and agricultural net primary production (NPP) as indictors to assess where and when there might be dangerous effects arising from the projected climate changes for Chinese agricultural production. The results showed that based on HadCM3-based climate change scenarios, the region between the North China Plain and Northeast China Plain (34.25–47.75°N, 110.25–126.25°E) would be vulnerable to the projected climate change. The analyses on inter-annual variability showed that the agricultural water resources conditions would fluctuate through the period of 2001–2080 in the region under IPCC SRES A2 scenario, with the period of 2021–2040 as critical drought period. Agricultural NPP is projected to have a general increasing trend through the period of 2001–2080; however, it could decrease during the period of 2005–2035 in the region under the IPCC SRES A2 scenario, and during the period of 2025–2035 under IPCC SRES B2 scenario. Generally, while projected climate change could bring some potentially improved conditions for Chinese agriculture, it could also bring some critical adverse changes in water resources, which would affect the overall outcome. At this stage, while we have identified certain risks and established the general shape of the damage curve expressed as a function of global mean temperature increase, more works are needed to identify specific changes which could be dangerous for food security in China. Therefore, there is a need for the development of more integrated assessment models, which include social-economic, agricultural production and food trade modules, to help identify thresholds for impacts in further studies.  相似文献   
63.
Exposure to dioxins has raised much public concern recently. We determined the congeners' distribution of polychlorinated-dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in the breast milk samples collected in Tokyo, Japan. Breast milk was taken from 240 mothers, 30 days after delivery in 1999 and 2000 in Tokyo, Japan. The actual concentration and TEQ concentration of PCDDs (14 congeners), PCDFs (15 congeners), and dl-PCBs (12 congeners), and each congener's contribution to the total TEQ level were calculated. Among all the samples, PCDDs accounted for 34.8%, PCDFs accounted for 23.5%, dl-PCBs accounted for 41.7%, which was also similar in the breast milk from the primiparae and secundiparae. The main contributors to the total TEQ with increasing percentages were 2,3,4,7,8-PeCDF, 1,2,3,7,8-PeCDD and 3,3',4,4',5-PCB (#126), and they accounted for more than 65% of the total TEQ. Detailed congener analysis in breast milk samples is effective to understand dioxin sources.  相似文献   
64.
Suzuki Y  Watanabe I  Tanabe S  Kuno K 《Chemosphere》2006,64(8):1296-1310
Formosan squirrels are considered a useful bio-indicator because their habitat exists within that of humans. Therefore, concentrations of 19 trace elements were determined in tissues of this species for assessment of environmental pollution in urban Kamakura and rural Izuohshima. Results of analyses revealed high Cu concentrations in the livers of Formosan squirrels. Moreover, concentrations of some trace elements from automobile exhausts-V, Zn, Cu and As-in the specimens from Kamakura were higher than those from Izuohshima. These results reflect the presence of pollution caused by human activities in Kamakura.  相似文献   
65.
The integrated model is composed of two basic parts: one is a reaction rate model of biodegradation in combination with bioenergetics and the other is a thermal engineering model of energy flow and balance in the bioreactor. Integrating these models provides possibility to estimate microbial activity using time course of physicochemical parameters such as bed temperature, bed weight, and/or C02 concentration during decomposition.  相似文献   
66.
气候变暖对黑龙江省水稻生产影响及对策研究   总被引:9,自引:0,他引:9  
利用哈尔滨市和佳木斯市1951—2005年的气象资料,结合当地水稻生产的特点,研究了气候变暖对黑龙江省水稻的低温冷害、春季干旱、高温障碍和病虫草害等的影响。并在分析水稻生产中所存在的问题的基础上,提出了今后应对气候变暖、减轻灾害损失和实现水稻生产稳步发展的实用技术对策。同时分析了目前气候变暖研究中存在的问题,并提出了以消除城市热岛效应对气候观测指标的影响为核心,进一步深入研究气候变暖问题的新思路。  相似文献   
67.
The synthesis of recycled plastics from recovered monomeric materials obtained from the depolymerization reaction of fiber-reinforced plastics (FRP) was examined. The depolymerization reaction of FRP in the presence of N,N-dimethylaminopyridine (DMAP) smoothly yielded the corresponding monomers, which mainly consisted of dimethyl phthalates. The polymerization reaction with this monomer failed to form the corresponding unsaturated polyesters due to contamination by N-methyl-4-pyridone, a decomposition product of DMAP. An efficient purification of the recovered monomer was achieved by washing with water, and the purified monomer successfully yielded the corresponding polymers. A hardness test revealed that the polymers were as hard as the polyester made from virgin materials. The present modification provides a practical method for the preparation of recycled plastics from depolymerized plastics.  相似文献   
68.
Norovirus GII.3, GII.4, and GII.17 were detected using pyrosequencing in sewage and oysters in January and February 2015, in Japan. The strains in sewage and oyster samples were genetically identical or similar, predominant strains belonging to GII.17 Kawasaki 2014 lineage. This is the first report of GII.17 Kawasaki 2014 in oysters.  相似文献   
69.
To evaluate the effect of increasing nitrogen (N) deposition and tropospheric ozone (O3) concentrations on N-saturated forest ecosystems, we investigated the response of Japanese red pine (Pinus densiflora), an N-saturation sensitive tree species, to increasing N load under elevated O3 concentrations. One-year-old seedlings of red pine were treated with three levels of N supply (0, 50 and 100 mg N L-1 fresh soil volume) under two levels of atmospheric O3 concentration (< 5 and 60 ppb) for two growing seasons. Nitrogen treatment did not stimulate dry matter production of the seedlings. Growth inhibition was observed in the highest N treatment under low O3 and in the two higher N treatments under elevated O3. Irrespective of the O3 concentration, increasing N supply negatively affected root growth and mycorrhizal development in fine roots, resulting in a reduction in P and Mg uptake from the soil. Net photosynthetic rate was significantly reduced by both the highest N treatment under low O3 and the two higher N treatments under elevated O3, together with decreased N-availability to Rubisco. Nitrogen assimilated from NO3 - to amino acid in the needles was not affected by the treatments. However, needle protein concentration was reduced by the highest N-treatment under low O3 and by the two higher N-treatments under elevated O3. These results suggest that elevated O3 potentially disturbs the N-availability in the form of protein including Rubisco, and may advance the negative effects of excessive N-deposition on N-sensitive plant species in N-saturated forests.  相似文献   
70.
A numerical simulation model of pesticide runoff through vegetative filer strips (PRVFS) was developed as a tool for investigating the effects of pesticide transport mechanisms on VFS design in dormant-sprayed orchard. The PRVFS model was developed applying existing theories such as kinematic wave theory and mixing zone theory for pesticide transport in the bare soil area. For VFS area, the model performs flow routing by simple mass accounting in sequential segments and the pesticide mass balance by considering pesticide washoff and adsorption processes on the leaf, vegetative litter, root zone and soil. Model sensitivity analysis indicated that pesticide transfer from surface soil to overland flow and pesticide washoff from the VFS were important mechanisms affecting diazinon transport. The VFS cover ratio and rainfall intensity can be important design parameters for controlling diazinon runoff using inter-row VFS in orchard. The PRVFS model was validated using micro-ecosystem simulation of diazinon transport for 0, 50 and 100% VFS cover conditions. The PRVFS model is shown to be a beneficial tool for evaluating and analyzing possible best management practices for controlling offsite runoff of dormant-sprayed diazinon in orchards during the rainy season.  相似文献   
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