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581.
Many water-related problems are shared by most of the developing countries and the industrialized nations could be in position of offering aid in such problems. Water scarcity and access to safe water, water pollution, severe storms and floods, droughts, waterborne diseases and landslides and mud floods are the most commonly shared problems among developing nations. These problems were discussed in a workshop organized as part of the Fifth International Symposium on Environmental Hydraulics in 2008. The discussion included identification of actors both in the developing and developed nations (vgr. local and national governments, NGOs, universities, foundations and private and public research institutions), aid modalities such as education, technology transfer, technology development and direct investment as well as restrictions and barriers in the form of political and legal issues, economic limitations, cultural differences and geographic distances. Recommendations about how developed nations could help developing countries are issued. 相似文献
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Cleisson Fábio A. Peralta Victor Bunduki José Píndaro P. Plese Eberval Gadelha Figueiredo Javier Miguelez Marcelo Zugaib 《黑龙江环境通报》2003,23(4):311-314
This study presents 30 cases of fetal isolated spina bifida aperta (SBA) to identify prenatal ultrasound findings that could predict the prognosis. Comparisons between surviving patients who had normal (group 1) and abnormal (group 2) post-natal neurological outcomes were made for three different prenatal signs, that is, site of vertebral lesion, presence and degree of ventriculomegaly and presence of talipes. The site of the lesion was the most significant outcome predictor, as high spinal dysraphisms were observed in 2 patients (2/7–28.6%) in group 1 and in 15 patients (15/19–79.0%) in group 2 (p = 0.03). The presence of fetal ventriculomegaly was associated with impaired post-natal neurological development, as it occurred in 4 patients (4/7–57.1%) in group 1 and in 18 patients (18/19–94.7%) in group 2 (p = 0.04). The presence of talipes did not significantly differ between the two groups. Patients with abnormal intellectual outcome (8/26–30.8%) had significantly greater (p = 0.018) lateral ventricle/hemisphere ratios (mean = 0.74, standard deviation = 0.13) than those with normal intellectual development (mean = 0.54, standard deviation = 0.18). Mean post-natal follow-up was at 23 months (standard deviation = 15 months). Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
586.
The toxicity of pesticides has been evaluated by several methods including tests with earthworms in both artificial and natural soils treated with the compounds. The ecological niches of earthworms make them good bioindicators of soil contamination. The bioaccumulation of 14C-simazine (6-chloro-N2-N4-diethyl- 1,3,5-triazine-2,4-diamine) was evaluated in earthworms (Eisenia foetida) maintained during three months in two substrates with different physical-chemical characteristics. The substrates were treated with 3.0 mg and 330 kBq of 14C-simazine kg(-1) substrate. Results indicated that worms did not influence simazine dissipation in both substrates as indicated by similar recoveries and with no statistical differences with and without earthworms. The radiocarbon recoveries were 86.8 and 95.3%, respectively in the substrates with lower and higher organic matter contents with earthworms, and 91.0 and 107.4% in the same substrates without worms. However, in earthworms the recoveries were statistically higher when they were maintained in the substrate with lower amount of organic matter (0.89%) than from the higher one (0.33%). Consequently, 14C-simazine bioconcentration factor (BCF) was also greater in the substrate with lower organic matter (6.89+/-1.55) than in the substrate with higher organic matter content (0.88+/-0.06). The results suggest that the higher soil organic matter content will cause lower probability of contamination of soil organisms with simazine. 相似文献
587.
Velini ED Galo ML Carvalho FT Martins D Cavenaghi AL Trindade ML Bravin LF Negrisoli E Antuniassi UR Simionato JL Santos SC 《Journal of environmental science and health. Part. B》2005,40(1):85-100
The general objective of this work was to develop a monitoring and management model for aquatic plants that could be used in reservoir cascades in Brazil, using the reservoirs of AES-Tietê as a study case. The investigations were carried out at the reservoirs of Barra-Bonita, Bariri, Ibitinga, Promiss?o, and Nova-Avanhandava, located in the Tietê River Basin; Agua Vermelha, located in the Grande River Basin; Caconde, Limoeiro, and Euclides da Cunha, which are part of the Pardo River Basin; and the Mogi-Gua?u reservoir, which belongs to the Mogi-Gua?u River basin. The main products of this work were: development of techniques using satellite-generated images for monitoring and planning aquatic plant control; planning and construction of a boat to move coating plant masses and an airboat equipped with a DGPS navigation and application flow control system. Results allowed to conclude that the occurrence of all types of aquatic plants is directly associated with sedimentation process and, consequently, with nutrient and light availability. Reservoirs placed at the beginning of cascades are more subject to sedimentation and occurrence of marginal, floating and emerged plants, and are the priority when it comes to controlling these plants, since they provide a supply of weeds for the other reservoirs. Reservoirs placed downstream show smaller amounts of water-suspended solids, with greater transmission of light and occurrence of submerged plants. 相似文献
588.
Effects of arbuscular mycorrhizal fungi on the root uptake and translocation of radiocaesium 总被引:5,自引:0,他引:5
Dupré de Boulois H Delvaux B Declerck S 《Environmental pollution (Barking, Essex : 1987)》2005,134(3):515-524
Because mycorrhizal fungi are intimately associated with plant roots, their importance in radionuclide (RN) recycling and subsequent dispersion into the biosphere has received an increasing interest. Recently, the capacity of arbuscular mycorrhizal fungi to take up and translocate radiocaesium to their host was demonstrated. However, the relative contribution of these processes in comparison to the ones of roots remains unknown. Here, the respective contributions of the hyphae of a Glomus species and the transformed carrot (Daucus carota L.) roots on radiocaesium uptake and translocation were compared and quantified. We observed that radiocaesium uptake by hyphae was significantly lower as compared to that of the roots, while the opposite was noted for radiocaesium translocation/uptake ratio. We also observed that the intraradical fungal structures might induce a local accumulation of radiocaesium and concurrently reduce its translocation within mycorrhizal roots. We believe that intraradical fungal structures might induce the down-regulation of radiocaesium channels involved in the transport processes of radiocaesium towards the xylem. 相似文献
589.
Mineralization of paracetamol in aqueous medium by anodic oxidation with a boron-doped diamond electrode 总被引:6,自引:0,他引:6
Brillas E Sirés I Arias C Cabot PL Centellas F Rodríguez RM Garrido JA 《Chemosphere》2005,58(4):399-406
The degradation of 100ml of solutions with paracetamol (N-(4-hydroxyphenyl)acetamide) up to 1 g l(-1) in the pH range 2.0-12.0 has been studied by anodic oxidation in a cell with a boron-doped diamond (BDD) anode and a graphite cathode, both of 3-cm2 area, by applying a current of 100, 300 and 450 mA between 25 and 45 degrees C. Complete mineralization is always achieved due to the great concentration of hydroxyl radical (*OH) generated at the BDD surface, with release of NH4+ and NO3- ions. The mineralization rate is pH-independent, increases with increasing applied current and temperature, but decreases when drug concentration raises from 315 mg l(-1). Reversed-phase chromatography revealed a similar complex paracetamol decay in acid and alkaline media. Ion-exclusion chromatography allowed the detection of oxalic and oxamic acids as ultimate carboxylic acids. When the same solutions have been comparatively treated with a Pt anode, a quite poor mineralization is found because of the production of much lower *OH concentration. Under these conditions, the degradation rate is enhanced in alkaline medium and polymerization of intermediates is favored in concentrated solutions. Paracetamol can be completely destroyed with Pt and its kinetics follows a pseudo-first-order reaction with a constant rate independent of pH. 相似文献
590.
Nisbet AF Mercer JA Rantavaara A Hanninen R Vandecasteele C Carlé B Hardeman F Ioannides KG Papachristodoulou C Tzialla C Ollagnon H Jullien T Pupin V 《Journal of environmental radioactivity》2005,83(3):263-274
The EC FARMING network (Food and Agriculture Restoration Management Involving Networked Groups) was set up to bring together the many and diverse stakeholders who would be involved in intervention following wide scale radioactive contamination of the food chain, so that acceptable strategies can be developed for maintaining agricultural production and safe food supply. The network comprises stakeholder panels in the UK, Finland, Belgium, France and Greece that have met regularly since 2001 to debate, discuss and exchange opinion on the acceptability, constraints and impact of various countermeasure options and strategies. The objectives of this paper are to consolidate the main achievements of the FARMING project over the period 2000-2004, to highlight the various difficulties that were encountered and to discuss the challenges for engaging stakeholders in off-site emergency management and long-term rehabilitation in the future. 相似文献