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71.
Environmental Chemistry Letters - Glyphosate is considered toxicologically harmful and presents potential association with human carcinogenesis and other chronic diseases, including mental and...  相似文献   
72.
The adoption of environmentally sustainable techniques by cooperatives and small companies results in specific difficulties rarely discussed in the literature. This paper describes an action-research carried out by seafood cultivators and university researchers in Guanabara Bay, which resulted in the substitution of the previous technique, based on extraction, by one without negative environmental impacts. The economic results have been satisfactory, so it can be expected that this activity may become more widespread in the region.  相似文献   
73.
74.
The objective of this study was to examine postfire regeneration of tree, shrub, and dwarf shrub species, in relation to levels of damage in four planted pine forests (Pinus pinea, Pinus pinaster) in Andalusia. A prefire vegetation map was used for detailing species composition, vertical structure, and density and another for detailing the extent and intensity of fire damage. Between 3 and 7 years after the fires, an inventory was made of the vegetation in each area, using the step-point method. The information thus obtained was used to determine the amount of cover in the dwarf/shrub and tree layers, the frequency of species in each of the layers, floristic richness, and diversity (Shannon index). The botanical composition of the dwarf and shrub layer was analyzed using TWINSPAN. Variables were poorly correlated with level of fire damage, which suggests that the forests in this study followed the autosuccession model. Because of the artificial origin or seminatural condition, regeneration of the dominant tree species is poor, and it seems unlikely that forests will recover to their prefire state. Therefore action is recommended to restore these ecosystems.  相似文献   
75.
Two sulfonylurea herbicides, chlorsulfuron and metsulfuron-methyl, were studied under laboratory conditions, in order to elucidate the biodegradation pathway operated by Aspergillus niger, a common soil fungus, which is often involved in the degradation of xenobiotics. HPLC-UV was used to study the kinetic of degradation, whereas LC-MS was used to identify the metabolites structure. In order to avoid the chemical degradation induced by a decrease in pH, due to the production of citric acid by the fungus, the experiments were performed in a buffered neutral medium. No significant degradation for both compounds was observed in mineral medium with 0.2% sodium acetate. On the contrary, in a rich medium, after 28 days the degradations, chemical degradation excluded, were about 30% for chlorsulfuron and 33% for metsulfuron-methyl. The main microbial metabolites were obtained via cleavage of the sulfonylurea bridge. In addition the fungus seems to be able to hydroxylate the aromatic ring of chlorsulfuron. In the case of metsulfuron-methyl the only detected metabolite was the triazine derivative, while the aromatic portion was completely degraded. Finally, the demethylation of the methoxy group on the triazine ring, previously observed with a Pseudomonas fluorescens strain, was not observed with A. niger.  相似文献   
76.
This study examines the extent to which human resource (HR) training (content and context) is contingent on business strategy (i.e. classified according to Miles and Snow (1984) typology—‘Designing strategic human resource systems’, Organizational Dynamics, 13 , 36–52) as well as the characteristics of the work process. Sixty‐five Spanish organizations (i.e. 65 senior executives and 65 senior HR officers) participated in the study. Using primarily factorial and cluster analyses, support was found to the assertion that companies adopting a particular type of training strategy/policy have a high degree of internal consistency amongst the training objectives sought. In terms of work processes and training, results indicate that under work processes where the content of work provides for enrichment and for long‐term results, companies tend to adopt training strategies where emphasis is on enhancement of individual specialized skills aimed at improving direct productivity. By contrast, firms who use work processes that are characterized by repetitive and routine tasks, de‐emphasize this type of training content. Results also indicae that limited level of contingencies exist between training policies and business strategy, especially when time dimension is also accounted for. While the theory suggests that organizations that have their HR training fit (contingent) on their business strategy are more effective, the empirical results portrayed in this study shows a more complex picture. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   
77.
The aim of this work was to evaluate the use of solid residues derived from municipal solid waste-derived solid recovered fuel incinerated in a circulating fluidized-bed boiler for concrete production. The concrete mixtures casted by partially replacing the natural aggregates with bottom ash (27 %) and exhausted sand (13 %), according to the European standards for concrete, may be classified in the C16/20 class. The leaching tests performed on monolithic concrete samples showed that the concentrations measured in the leachates were lower than limit values for waste recovery, with the only exception of nickel for the mixture made with the exhausted sand.  相似文献   
78.
The present study investigates the application of a noncommercial peroxidase enzyme, which was extracted from rice bran, to decolorize wastewater that was simulating effluent from a textile manufacturer using a red dye in its coloration process.  相似文献   
79.
Atmospheric fine and coarse particles were collected in Teflon filters in three cities of the region of the Lower Sinos River Basin of Rio Grande do Sul in the year 2010. The filters were Soxhlet extracted, and 14 priority PAHs were analyzed using a gas chromatograph coupled to a mass spectrometer (GC/MS). The principal emission sources of these compounds were assessed by using diagnostic ratios and receptor model: positive matrix factorization (PMF 3.0) of the US Environmental Protection Agency. The results of PAHs concentration for the studied year showed significant levels of high molecular weight (HMW) PAH, Ind, and BghiP, in PM2.5 in the winter season, showing the influence of mobile sources. The application of receptor model PMF 3.0 revealed that the main sources of PAHs were vehicle fleet (both diesel and gasoline), followed by coal combustion, wood combustion, and resuspension of dust. The results of the receptor modeling are in agreement with the data obtained by the ratio diagnostic.  相似文献   
80.
The scientific literature regarding HEMS (Helicopter Emergency Medical Service) planning lacks a method for defining optimal sites for helipads that takes into account risk distribution and hospital location. Such a method could minimise overall rescue time in emergency situations. In this paper a method that supports the decisions taken by disaster planners and managers is developed, focusing on the quantification of necessary air resources for the management of some probable calamities. Given a region characterised by a natural and non-natural disaster risk map, along with a comprehensive transport system (also characterised by a risk map), a set of emergency destinations (hospitals), a set of heliports/helipads dislocated on the territory and a number of available HEMS rotorcraft, the aim of the paper is to assess the adequacy of the VTOL/FATO (Vertical Take-Off and Landing/Final Take-Off and Landing Area) system in order to deal with a set of possible emergencies.  相似文献   
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