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441.
Ana Rita Ribeiro Carlos Magalhães Afonso Paula M. L. Castro Maria Elizabeth Tiritan 《Environmental Chemistry Letters》2013,11(1):83-90
The accurate quantification of enantiomers is crucial for assessing the biodegradation of chiral pharmaceuticals in the environment. Methods to quantify enantiomers in environmental matrices are scarce. Here, we used an enantioselective method, high-performance liquid chromatography with fluorescence detection (HPLC-FD), to analyze two beta-blockers, metoprolol and atenolol, and the antidepressant fluoxetine in an activated sludge consortium from a wastewater treatment plant. The vancomycin-based chiral stationary phase was used under polar ionic mode to achieve the enantioseparation of target chiral pharmaceuticals in a single chromatographic run. The method was successfully validated over a concentration range of 20–800 ng/mL for each enantiomer of both beta-blockers and of 50–800 ng/mL for fluoxetine enantiomers. The limits of detection were between 5 and 20 ng/mL and the limits of quantification were between 20 and 50 ng/mL, for all enantiomers. The intra- and inter-batch precision was lower than 5.66 and 8.37 %, respectively. Accuracy values were between 103.03 and 117.92 %, and recovery rates were in the range of 88.48–116.62 %. Furthermore, the enantioselective biodegradation of atenolol, metoprolol and fluoxetine was followed during 15 days. The (S)-enantiomeric form of metoprolol was degraded at higher extents, whereas the degradation of atenolol and fluoxetine did not show enantioselectivity under the applied conditions. 相似文献
442.
Tomás B. Ramos Inês Alves Rui Subtil João Joanaz de Melo 《Journal of Cleaner Production》2009,17(1):36-52
The environmental performance evaluation (EPE) of organizations is becoming an autonomous management tool. The main goal of this research was to assess the state of EPE practice in the Portuguese defence sector, as a particular part of public services. A questionnaire survey was conducted involving all Portuguese military units that have a person in charge of environmental issues. The questionnaire was designed to assess: (i) the importance and drivers of EPE; (ii) the ISO 14031 knowledge and implementation; (iii) the knowledge and use of environmental indicators; (iv) the optimal format for indicators; and (v) the advantages and drawbacks of using environmental indicators. Despite various initiatives driving environmental practices in public organizations, most of that experience is only centred on an environmental management system, and EPE is quite a new issue. Nevertheless, general environmental performance evaluation is a growing reality and one in which Portuguese military units are taking an increasing interest. Overall respondents agree on the importance of measuring and communicating environmental performance related to their main missions and activities. The main drivers for EPE in military units are the prevention of health risks and compliance with regulations. However, to date, ISO 14031 and environmental performance indicators are almost unknown in the respondent military units. Among the three military branches, the Navy revealed the worst environmental performance evaluation knowledge, awareness and practice. 相似文献
443.
444.
Renata Durães Bette A. Loiselle John G. Blake 《Behavioral ecology and sociobiology》2008,62(12):1947-1957
Leks, display grounds where males congregate and females visit to copulate, are typically traditional in location, despite
often high turnover of individual males. How leks can persist in face of male turnover is not well understood, in part due
to a lack of detailed field data allowing for a clear understanding of lek dynamics. We followed the fate of individual males
at 11 to 15 leks of the blue-crowned manakin Lepidothrix coronata across four breeding seasons to gain insights on how leks are formed and changed in space and time. Between years, leks were
traditional in location despite changes in territory ownership due to male disappearance and recruitment. New males were equally
likely to recruit by taking over existing territories or by establishing new territories. Recruitment was influenced by age,
as recruits were more likely to be adults than subadults. Lek size did not affect the probabilities of a male recruiting or
persisting at a territory, and vocalization rate, a correlate of mating success in this population, did not affect male persistence.
We used our field data to model changes in lek size and composition over longer periods of time (100 years) to understand
how lek traditionality can be reconciled with high male turnover. Our simulations showed that leks in our population rapidly
stabilize in size despite changes in territory ownership and that rates of male recruitment and disappearance compensate each
other, such that leks have the potential to persist for several decades after the original males have disappeared from them. 相似文献
445.
Increasing interest in biofuels trade between developed and developing countries has spurred worldwide discussions on issues such as subsidies and the ‘food for fuel’ crisis. One issue missing in recent discourse is the pressure exerted on developing countries to adopt large-scale mechanized farming practices to increase economic efficiencies. Such approaches often exclude small-scale farmers from participating in the emerging biofuels market, thus exacerbating poverty and social exclusion. Drawing on both qualitative and technical data, we discuss such pressures using Brazilian ethanol and biodiesel production. Pressure from international markets to become more economically efficient may contribute towards the erosion of recent schemes to encourage social benefits for small farmers in biodiesel production. We conclude with trade and policy implications. 相似文献
446.
447.
Lino Tralhão João Coutinho-Rodrigues Luís Alçada-Almeida 《Waste management (New York, N.Y.)》2010,30(12):2418-2429
The location of multi-compartment sorted waste containers for recycling purposes in cities is an important problem in the context of urban waste management. The costs associated with those facilities and the impacts placed on populations are important concerns. This paper introduces a mixed-integer, multiobjective programming approach to identify the locations and capacities of such facilities. The approach incorporates an optimization model in a Geographical Information System (GIS)-based interactive decision support system that includes four objectives. The first objective minimizes the total investment cost; the second one minimizes the average distance from dwellings to the respective multi-compartment container; the last two objectives address the “pull” and “push” characteristics of the decision problem, one by minimizing the number of individuals too close to any container, and the other by minimizing the number of dwellings too far from the respective multi-compartment container. The model determines the number of facilities to be opened, the respective container capacities, their locations, their respective shares of the total waste of each type to be collected, and the dwellings assigned to each facility. The approach proposed was tested with a case study for the historical center of Coimbra city, Portugal, where a large urban renovation project, addressing about 800 buildings, is being undertaken. This paper demonstrates that the models and techniques incorporated in the interactive decision support system (IDSS) can be used to assist a decision maker (DM) in analyzing this complex problem in a realistically sized urban application. Ten solutions consisting of different combinations of underground containers for the disposal of four types of sorted waste in 12 candidate sites, were generated. These solutions and tradeoffs among the objectives are presented to the DM via tables, graphs, color-coded maps and other graphics. The DM can then use this information to “guide” the IDSS in identifying additional solutions of potential interest. Nevertheless, this research showed that a particular solution with a better objective balance can be identified. The actual sequence of additional solutions generated will depend upon the objectives and preferences of the DM in a specific application. 相似文献
448.
Percilia Cardoso Giaquinto Claudia Militão da Silva Berbert Helton Carlos Delicio 《Behavioral ecology and sociobiology》2010,64(6):1029-1035
Selection favors females that attend to reliable information about male genetic quality and fitness. Male nutritional condition
can be a significant sign of mate quality since poor nutrition can be related to reduced sperm quality, low sperm quantity,
sexually transmitted diseases, and parasites. We tested whether female Nile tilapia, Oreochromis niloticus, preferred the chemical cues of males that were well fed with high-protein diet over those fed with low-protein diet. Females
do not only discriminate between males but also show a preference for well-fed males, discriminating between the odors with
respect to nutritional state, suggesting that they were responding to a food-specific chemical cue. It is therefore likely
that nutritional condition is related to the production of pheromones in males. Our results suggest that information about
male nutritional state can be conveyed in chemical cues and that females attend to these cues during mate choice. 相似文献
449.
Teresa Carvalho Fernando Durão Célia Ferreira 《Waste management (New York, N.Y.)》2010,30(11):2209-2215
The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit. 相似文献
450.
Bernardo Guimarães Pedro Simões Rui Cunha Marques 《Journal of environmental management》2010,91(12):2632-2638
The urban waste market has evolved significantly in the past decades, which among other changes, has led to the creation of new utilities and new business models. However, very few things have changed for the users. Urban waste collection remains mainly under the responsibility of local authorities and the charges paid by the users in most countries are very low compared to the provision costs. This situation forces the injection of public money into the system, encouraging the ‘quiet-life’ within the utilities and, therefore, inefficiency. The present study intends to analyze the potential for the application of the Balanced Scorecard (BSc) methodology into the waste utilities. After a comprehensive revision of the urban waste sector in Portugal, the methodology of BSc and its application in local public services is described and discussed. Focusing on implementation rather than on strategy, a set of performance indicators is proposed to be utilized in the different management models of waste utilities in Portugal: the municipalities, semi-autonomous utilities, municipal companies and mixed companies. This implementation is then exemplified through four case studies, one for each type of utility. This paper provides a flexible framework proposal to be applied to waste utilities operating both in Portugal and abroad. 相似文献