Assessment of environmental contamination on ecology (plant) at molecular and population levels is important in risk quantification and remediation study. Random amplified polymorphic DNA (RAPD) assay and related other fingerprinting techniques have been employed to detect the genotoxin-induced DNA damage and mutations. This research compared the effects occurring at molecular and population levels in rice seedlings exposed to cadmium (Cd) concentrations of 15-60 mg l(-1) for 8 days with quartz sand culture. Inhibition of root growth and increase of total soluble protein content in root tips of rice seedlings were observed with the increase of Cd concentration. For the RAPD analyses, 12 RAPD primers of 50-70% GC content were found to produce unique polymorphic band patterns and subsequently were used to produce a total of 180 bands of 179-3056 bp in molecular size in the control root tips of rice seedlings. Results produced by these RAPD primers indicate that changes in RAPD profiles of root tips after Cd treatment include modifications in band intensity and gain or loss of bands by comparison with control. The effect of changes was dose-dependent. Genomic template stability compares favourably with the traditional indices such as root growth and soluble protein content. The DNA polymorphisms detected by RAPD analysis can be applied as a suitable biomarker assay for the detection of genotoxic effects of Cd contamination on plants. 相似文献
The performance of six concentration method combinations and two quantitative analysis techniques were evaluated in terms of enterovirus recovery efficiencies by adjusting the pH and salt concentration of water samples. Of the six concentration method combinations, adsorption on nitrocellulose membranes followed by an acid rinse elution consistently gave the highest recovery efficiencies. In theory, an electropositive membrane should be the most appropriate technique for adsorption of electronegative viruses in pure water. However, it displayed the greatest loss in natural waters. For adsorption and elution procedures, both the electronegative membrane, accompanied by an acid rinse step, and the electropositive membrane, accompanied by a glycine rinse step, provided higher recovery efficiencies. MPN-RT-PCR, a statistically quantitative analysis method, performed more efficiently, in economic terms, but had a similar enterovirus recovery trend to real-time RT-PCR, which is the authoritative quantitative analysis method for nucleic acid. 相似文献
Adsorption of sulfapyridine, tetracycline, and tylosin to a commercial microporous activated carbon (AC) and its potassium hydroxide (KOH)-, CO-, and steam-treated counterparts (prepared by heating at 850°C) was studied to explore efficient adsorbents for the removal of selected pharmaceuticals from water. Phenol and nitrobenzene were included as additional adsorbates, and nonporous graphite was included as a model adsorbent. The activation treatments markedly increased the specific surface area and enlarged the pore sizes of the mesopores of AC (with the strongest effects shown on the KOH-treated AC). Adsorption of large-size tetracycline and tylosin was greatly enhanced, especially for the KOH-treated AC (more than one order of magnitude), probably due to the alleviated size-exclusion effect. However, the treatments had little effect on adsorption of low-size phenol and nitrobenzene due to the predominance of micropore-filling effect in adsorption and the nearly unaffected content of small micropores causative to such effect. These hypothesized mechanisms on pore-size dependent adsorption were further tested by comparing surface area-normalized adsorption data and adsorbent pore size distributions with and without the presence of adsorbed antibiotics. The findings indicate that efficient adsorption of bulky pharmaceuticals to AC can be achieved by enlarging the adsorbent pore size through suitable activation treatments. 相似文献
Most members of Taiwan's indigenous communities live in areas that are prone to natural disasters. Yet, due to their marginalised cultural, economic and political status, each time such calamities strike, any assistance they receive is usually provided without considering their actual needs. The areas hardest hit by Typhoon Morakot in August 2009 were the indigenous villages in the southern and eastern parts of the island. After the initial emergency relief efforts had been completed, there remained the highly challenging task of reconstruction and the resettlement of those who lost their homes and livelihoods. This paper examines the cultural conflicts that arose during the reconstruction process, with special emphasis on the participation of Taiwan's indigenous communities and their capacity for resilience. It was found that community participation and identification are key issues in effective disaster governance. 相似文献
The empirical research on the relationship between corporate environmental responsibility and environmental performance remains in the one-way positive impact and lacks the research on nonlinear relationship between them. Based on the stakeholder theory, this paper selects A-share chemical–listed companies in China from 2006 to 2017 as the research samples and uses generalized method of moments (GMM) model to investigate the impact mechanism between corporate environmental responsibility and environmental performance. The results showed that corporate environmental responsibility positively impacted on environmental performance; however, the impact was not significant. The corporate environmental performance positively and significantly impacted on environmental responsibility. Moreover, results reported that industry competition played a positive regulatory role in corporate environmental responsibility affecting environmental performance and has played a positive role in corporate environmental impact on environmental responsibility. A nonlinear relationship (inverted “U” shape) between environmental responsibility and environmental performance was found. The study results stress to establish a fair and perfect market competition mechanism to improve the environmental performance of chemical industries in China.
Environmental Science and Pollution Research - Abstract Human activities, particularly in large cities, can lead to pollution caused by micropollutants such as pesticides in water bodies, which... 相似文献
Loessal soil is one of the main cultivated soils in northwest China. Part of its distribution area was irrigated with industrial wastewater in past three decades. This caused heavy metal contamination in the soil. It had induced toxicity on crops and also threatened local human health for now. Based on a field plot experiment, effects of different Cu concentrations (from 45 to 2000 mg kg?1) in loessal soil on spinach plant growth and uptake of mineral nutrients (Zn, Fe, Mg, K, and Ca) by spinach were investigated. The Cu addition increased available concentrations of mineral nutrients in loessal soil and concentrations of Cu, Zn, Mg, and Ca in roots. The translocation of mineral nutrients from roots to leaves was inhibited under Cu addition, inducing their decrease in leaves. The EC10 and EC50 of soil Cu in relative dry weights of leaves were 240.33 mg kg?1 and 1205.04 mg kg?1, respectively. The PLS-PM analysis showed that available concentrations of nutrients in soil were only affected by Cu in soil positively, nutrients in roots were mainly affected by Cu in soil and Cu in leaves positively, nutrients in leaves were mainly affected by Cu in roots negatively, translocation of nutrients in spinach and plant growth were principally affected by Cu in leaves negatively, and the total effect of Cu in leaves on nutrients in roots and leaves, translocation of nutrients in spinach, and plant growth was the highest. Our results indicated that the phytotoxicity of Cu including spinach growth inhibition and mineral disorder in spinach was mainly affected by the Cu concentrations in leaves.
Environmental Science and Pollution Research - Arsenic trioxide (ATO) and antimony (Sb) are well-known ubiquitous environmental contaminants and cause unpromising male reproductive effects in... 相似文献