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Результаты 1841-1850 из 2,459
The GMOS cyber(e)-infrastructure: advanced services for supporting science and policy
2014
Cinnirella, S. | D’Amore, F. | Bencardino, M. | Sprovieri, F. | Pirrone, N.
The need for coordinated, systematized and catalogued databases on mercury in the environment is of paramount importance as improved information can help the assessment of the effectiveness of measures established to phase out and ban mercury. Long-term monitoring sites have been established in a number of regions and countries for the measurement of mercury in ambient air and wet deposition. Long term measurements of mercury concentration in biota also produced a huge amount of information, but such initiatives are far from being within a global, systematic and interoperable approach. To address these weaknesses the on-going Global Mercury Observation System (GMOS) project ( www.gmos.eu ) established a coordinated global observation system for mercury as well it retrieved historical data ( www.gmos.eu/sdi ). To manage such large amount of information a technological infrastructure was planned. This high-performance back-end resource associated with sophisticated client applications enables data storage, computing services, telecommunications networks and all services necessary to support the activity. This paper reports the architecture definition of the GMOS Cyber(e)-Infrastructure and the services developed to support science and policy, including the United Nation Environmental Program. It finally describes new possibilities in data analysis and data management through client applications.
Показать больше [+] Меньше [-]Mercury (Hg) in fish consumed by the local population of the Jaguaribe River lower basin, Northeast Brazil
2014
Costa, B. G. B. | Lacerda, L. D.
The knowledge of Hg concentrations in fish is of considerable interest since these organisms are a major source of protein to coastal human populations and fishing communities. The main source of human exposure to Hg contamination occurs through the consumption of fish. In this paper, we compare Hg concentration in 13 fish species from Jaguaribe River lower basin and an adjacent coastal region in the northeastern coast of Brazil. We sampled fish from three stretches of the river: fluvial, estuarine, and marine regions. We tested the hypothesis that Hg concentration in muscle tissue vary according to species, location, and trophic level. Significant differences were observed among species and trophic level, but these could not be observed among the regions studied. As expected, the highest concentrations were observed in carnivorous fish (5.6–107.5; 26.9 ± 18.8 ng g⁻¹). Hg concentrations observed in this study are similar to those observed in regions of low environmental contamination. We estimated Hg intake to vary between 0.02 and 0.22 ng Hg kg body weight⁻¹ week⁻¹, for the average body weight of 56.7 kg, which was considered as low exposure and therefore, a low risk to consumers of fish from the regions studied.
Показать больше [+] Меньше [-]Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation
2014
Lin, Tao | Wu, Shouke | Chen, Wei
The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br⁻). Br⁻ions may be converted to bromate (BrO₃⁻) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O₃) dosage, contact time, pH, and Br⁻and ammonia (NH₃-N) concentrations on the formation of BrO₃⁻and Br-DBPs have been investigated. The results show that decreasing the initial Br⁻concentration is an effective means of controlling the formation of BrO₃⁻. When the concentration of Br⁻was lower than 100 μg/L, by keeping the ratio of O₃dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO₃⁻production was effectively suppressed. The concentration of BrO₃⁻steadily increased with increasing O₃dosage at high Br⁻concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO₃⁻and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO₃⁻and Br-DBPs.
Показать больше [+] Меньше [-]Effect of lead treatment on medicarpin accumulation and on the gene expression of key enzymes involved in medicarpin biosynthesis in Medicago sativa L
2014
Ghelich, Sima | Zarinkamar, Fatemeh | Mohammad Soltani, Bahram | Niknam, Vahid
Lead (Pb) is the most common heavy metal contaminant in the environment. The present study was undertaken to determine the effect of Pb treatment on medicarpin production and accumulation in Medicago sativa L. To this aim, 7- and 30-day-old plants were treated with 0, 120, 240, 500, and 1,000 μM Pb during 10 days. The content of medicarpin was determined by HPLC, and the extent of medicarpin production was deduced from the result of semiquantitative RT-PCR performed on PAL, CHS, and VR genes. HPLC results indicated that medicarpin concentration has been reduced in the roots, while its exudation to the culture medium has been increased. RT-PCR results indicated that the transcript levels of PAL, CHS, and VR genes have not been affected following Pb stress in seedlings. At the vegetative stage, transcript levels of PAL and CHS genes have been reduced in the roots. However, the transcript level of VR gene increased at 120 and 240 μM Pb, while it decreased at higher concentrations. In the shoot, the transcript levels of PAL, CHS, and VR genes were increased following increased concentration of lead in the medium. Overall, q-PCR results suggest that medicarpin biosynthesis has been induced in the shoots and reduced in the roots of the plants treated with a toxic concentration of Pb.
Показать больше [+] Меньше [-]The purple Codex Rossanensis: spectroscopic characterisation and first evidence of the use of the elderberry lake in a sixth century manuscript
2014
Bicchieri, M. (Marina)
This paper presents the results obtained during the measurements campaign started in June 2012 and ended in November 2013 on the invaluable purple Codex Rossanensis, sixth century, one of the oldest surviving illuminated manuscripts of the New Testament. The tasks of the chemistry laboratory were to answer a variety of questions posed both by historians and restorers, concerning the materials used in a previous restoration, the composition of the pictorial palette and the different inks and to determine which colouring material had been applied to dye the parchment support. It was also requested to determine the state of preservation of the manuscript, as a result of its interactions with the environment in which the manuscript had been stored and the vicissitudes experienced during its life (fire, previous restoration, exhibition). The spectroscopic analyses performed by micro-Raman, micro-Fourier transform infrared and X-ray fluorescence allowed to fill a gap in the knowledge of the pictorial materials used in the Early Middle Ages. The pictorial palette, the inks, the dye applied to obtain the purple parchments, the support and the materials used in the previous restoration treatment executed in 1917–19 were fully characterised. Moreover, to the author’s knowledge, the article shows the first experimental evidence of the use of the elderberry lake in a sixth century-illuminated manuscript. The lake was characterised by Raman spectroscopy.
Показать больше [+] Меньше [-]Alternation of antioxidative enzyme gene expression in rice seedlings exposed to methylene blue
2014
Yu, Xiao-Zhang | Zhang, Xue-Hong | Yue, Dong-Ming
Hydroponic experiments were conducted with rice seedlings (Oryza sativa L. cv. ND1) exposed to methylene blue (MB) to investigate the accumulation of hydrogen peroxide (H₂O₂) and activities and gene expression of antioxidant enzymes. Results showed that a linear decrease in relative growth rate and water use efficiency was observed with rice seedlings with increasing MB concentrations. MB-induced accumulation of H₂O₂was evident in both roots and shoots. The activities of antioxidative enzymes were analyzed and found to be different at different MB treatment concentrations. The activities of enzymes related to the ascorbate-glutathione cycle were more sensitive to MB treatments than other antioxidative enzymes. Transcript level, by real-time quantitative PCR, of antioxidative enzymes showed that the analyzed genes were differently expressed during different MB concentrations in both roots and shoots. The isoform analysis of superoxide dismutase (SOD) gene showed that the expressions of Cu/ZnSOD and MnSOD were relatively constant, where significant upregulation of FeSOD was observed with rice seedlings exposed to high MB concentrations. Furthermore, the expression of CAT, POD, and MDHAR genes responded biphasically to MB treatments by showing negligible changes at 1.56–15.63 μM MB and significant induction at 31.36–62.52 μM MB. The expression of GR, APX, and DHAR genes showed a remarkable induction to MB. Our results suggest that on transcription level, and in accordance with enzymatic responses, enzymes of GR, APX, and DHAR play central role in the H₂O₂detoxification in rice seedlings under MB exposure.
Показать больше [+] Меньше [-]Field application of electrokinetic remediation for multi-metal contaminated paddy soil using two-dimensional electrode configuration
2014
Kim, Woo-Seung | Jeon, Eun-Ki | Jung, Ji-Min | Jung, Hong-Bae | Ko, Sung-Hwan | Seo, Chang-Il | Baek, Kitae
In this study, we evaluated the feasibility of in situ electrokinetic remediation for arsenic (As)-, copper (Cu)-, and lead (Pb)-contaminated soil, in a pilot-scale field application with two-dimensional electrode configurations. Square and hexagonal configurations with different electrode spacing, 1 m and 2 m, were investigated under a constant 100 V. A square configuration with electrode spacing of 2 m removed 61.5 % of As, 11.4 % of Cu, and 0.9 % of Pb, respectively, and a hexagonal configuration with the same spacing showed a higher removal efficiency in top (59 % of As, 0–0.5 m) and middle (53 % of As, 0.5–1.0 m) layers, but much lower removal efficiency in the bottom layer (1–1.5 m), which was thought to be due to groundwater flow through periodic rise and fall of tides. Fractionation analysis showed that As bound to Fe–Mn oxyhydroxide was the main form of As removed by the electrokinetic process. The two-dimensional configuration wasted less electrical energy by Joule heating, and required fewer electrode installations, compared to the one-dimensional electrode configuration.
Показать больше [+] Меньше [-]PAH metabolites, GST and EROD in European eel (Anguilla anguilla) as possible indicators for eel habitat quality in German rivers
2014
Kammann, Ulrike | Brinkmann, Markus | Freese, Marko | Pohlmann, Jan-Dag | Stoffels, Sandra | Hollert, Henner | Hanel, Reinhold
The stock of the European eel (Anguilla anguilla L.) continues to decline and has reached a new minimum in 2011. Poor health status of the spawners due to organic contaminants is one of the possible causes for this dramatic situation. Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants, which are rapidly metabolized in vertebrates. EROD (ethoxyresorufin-O-deethylase) and GST (glutathione-S-transferase) are two enzymes involved in PAH detoxification in fish. In this study, PAH metabolites as well as EROD and GST activity in a large, comprising dataset of more than 260 migratory and pre-migratory eels from five large German river basin districts were used to describe PAH exposure and its metabolism as possible indicators for the habitat quality for eels. Eel from the river Elbe appear to be moderately contaminated with PAH. Highest mean values of PAH metabolites were analysed in fish from the river Rhine. However, the results suggest that contaminants such as PAH are metabolized in the fish and may have contributed to EROD activity in eels caught from the Elbe estuary to 600 km upstream. Since the eel’s onset of cessation of feeding is closely linked to maturation and migration, we propose bile pigments as new indicators contributing to identify the proportion of migratory eel, which is crucial information for eel management plans. We showed that PAH metabolites normalized to bile pigments as well as EROD could be used to describe the habitat quality and might be suitable parameters in search for suitable stocking habitats.
Показать больше [+] Меньше [-]Hazardous substances in indoor dust emitted from waste TV recycling facility
2014
Deng, Jingjing | Guo, Jie | Zhou, Xiaoyu | Zhou, Peng | Fu, Xiaoxu | Zhang, Wei | Lin, Kuangfei
Various hazardous substances contained in waste TV sets might be released into environment via dust during recycling activities. Two brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs), and tetrabromobisphenol A (TBBPA), and five kinds of heavy metals (Cu, Pb, Cd, Cr, and Ni) were detected in indoor dust collected from two workshops (TV dismantling workshop and subsequent recycling workshop). PBDEs concentrations in dust from waste wires recycling line (722,000 ng/g) were the highest among the studied sites, followed by those in manual dismantling–sorting line (117,000 ng/g), whereas TBBPA concentrations were the highest in manual dismantling–sorting line (557 ng/g) and printed circuit board (PCB) recycling line (428 ng/g). For heavy metals, Cu and Pb were the most enriched metals in all dust samples. The highest concentration of Pb (22,900 mg/kg) was found in TV dismantling workshop-floor dust. Meanwhile, Cu was the predominant metal in dust from the PCB recycling line, especially in dust collected from electrostatic separation area (42,700 mg/kg). Occupational exposure assessment results showed that workers were the most exposed to BDE-209 among the four PBDE congeners (BDE-47, BDE-99, BDE-153, and BDE-209) in both workshops. The hazard quotient (HQ) indicated that noncancerous effects were unlikely for both BFRs and heavy metals (HQ < 1), and carcinogenic risks for Cd, Cr, and Ni (risk < 10⁻⁶) on workers in two workshops were relatively low.
Показать больше [+] Меньше [-]Ballast water treatment systems: design, regulations, and selection under the choice varying priorities
2014
Satir, Tanzer
This paper investigates the role of ballast water treatment systems (BWTSs) and proposes a selection procedure for conventional merchant ships based on the financial, legal, and operational circumstances. Through the metallurgical revolution of the nineteenth century, commercial ships are converted to steel hull from wooden structures. By this innovative shift, use of ballast water became an essential part of ships for improving propulsion and stability while reducing stress on hull (instead of rocks). However, the content of ballast water is emerged since it relocates marine species from an ecological composition (usually cargo discharging port) to another one (loading port). Uncontrolled relocation of marine species may cause severe damage to existing ecological basis on ballast discharging area. BWTSs are developed for ships to eliminate marine species (i.e., aquatic invasive species) content by using a filtering device. It ensures an eco-friendly ballasting and de-ballasting process. The selection of proper BWTS is another debate since the BWTSs are designed with cost-quality and cost (eco)-performance variations. The proposed approach denoted that both tonnage and the age of ship are indicative factors on selection. The cost of installation varies based on installation space and active vs. project vessel cases.
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