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1.
The relation between fatty acid accumulation, activity of acetyl-CoA carboxylase (ACC), and consequently lipid accumulation was studied in the microalgae Chlorella vulgaris co-immobilized with the plant growth-promoting bacterium Azospirillum brasilense under dark heterotrophic conditions with Na acetate as a carbon source. In C. vulgaris immobilized alone, cultivation experiments for 6 days showed that ACC activity is directly related to fatty acid accumulation, especially in the last 3 days. In co-immobilization experiments, A. brasilense exerted a significant positive effect over ACC activity, increased the quantity in all nine main fatty acids, increased total lipid accumulation in C. vulgaris, and mitigated negative effects of nonoptimal temperature for growth. No correlation between ACC activity and lipid accumulation in the cells was established for three different temperatures. This study demonstrated that the interaction between A. brasilense and C. vulgaris has a significant effect on fatty acid and lipid accumulation in the microalgae.  相似文献   

2.
We have observed the evaporation of acoustically levitated water drops at 0 and 32% relative humidity in a moving gas stream which is nearly saturated with methyl salicylate vapor. The initial evaporation rate is characteristic of a pure water drop and gradually slows until the evaporation rate becomes that of pure methyl salicylate. The quantity of condensed methyl salicylate exceeds its Henry's law solubility in water by factors of more than 30–50. This apparent violation of Henry's law agrees with the concentration enhancements in the liquid phase found by glotfelty et al. (1987, Nature235, 602–605) during their field measurements of organophorus pesticides in fog water. Under our conditions, visual evidence demonstrates the presence of two liquid phases, thus invalidating the use of Henry's law. A continuum evaporation-condensation model for an immiscible two-component system which accounts for evaporative self-cooling of the drop correctly predicts the amount of methyl salicylate condensed onto the water drops.  相似文献   

3.
The EU Commission has proposed a way forward towards a Thematic Strategy for Soil Protection based on the distinction of seven soil functions and eight threats. A Technical Working Group on Research defined some 200 general priority research areas in the context of the dynamic DPSIR approach considering drivers, pressures, states, impacts and responses. Though quite valuable as a source document, this may be too generic and academic to be a starting point for new, effective soil research in different regions of the EU. A six-step storyline procedure is therefore proposed aimed at deriving effective operational procedures for a water management unit in a given region, using available soil expertise and defining new research only where needed. The procedure, that was illustrated for a Dutch case study, consists of defining: (i) water management units (wmu's) in a landscape context; (ii) land-use, area hydrology and soil functions (iii) soil threats and relevant soil qualities; (iv) drivers of land-use change and their future impact; (v) improvement of relevant soil qualities; (vi) possibilities to institutionalize soil quality improvement as part of the EU soil protection strategy. A focus on regional wmu's is likely to result in a strong commitment of local stakeholders and governmental officials, allowing a more specific DPSIR approach. But this will only work if local officials also receive legal powers to develop and enforce codified ‘good practices’, to be developed in the context of communities of practice. Innovative research topics can be derived from a combined analysis of experiences within different communities of practice in different wmu's and should not be left to researchers to define.  相似文献   

4.
The resources sector has come to accept that the global quest for sustainable development is one of the key shapers of its future development and business success. While much uncertainty remains regarding the full ramifications of sustainable development, it is uncontested that preventive environmental and resource productivity strategies, or eco-efficiency (EE), are conditional for the minerals industry's ability to progress in sustainable development. A customised framework for EE in minerals processing is proposed. It connects five prevention practices (process design; input substitution; plant improvement; good housekeeping; and reuse, recycling and recovery) with five resource productivity themes (resource efficiency; energy use and greenhouse gas emissions; water use and impacts; control of minor elements and toxics; and by-product creation). These are illustrated with practical examples from gold, base metals, alumina, aluminium and pigment operations in Australia. This illustrates that EE is possible from technical and operational perspectives, with implementation ultimately depending on the ability of project teams to build a convincing business case. Moreover, from a technology perspective, EE can be fostered at three distinct and mutually reinforcing innovation platforms: operations; plant design; and process technology.  相似文献   

5.
Environmental indicators allow a firm to make measurements related to its environmental performance. In practical terms, they can be used to form a measuring, benchmarking and monitoring tool to track environmental performance for small and medium enterprises (SMEs).Within an Environmental Management System (EMS), environmental indicators can be used to check if a firm has met the targets it is required to set for itself. It can also be used in firms that have not yet implemented an EMS. The use of an Environmental Indicators System (EIS) is thus recommended for SMEs, many of which do not have an EMS, in order to enhance their environmental performance. As noted in A Guide to Corporate Environmental Indicators published by the Federal Environment Ministry (Bonn) and the Federal Environmental Agency (Berlin), three categories of environmental indicators can be developed, depending on whether they describe: (1) a company's environmental impact (environmental performance); (2) the management's environmental activities; or (3) the external condition of the company's environment.The objective of this paper is to present how environmental indicators were established and implemented for Philippine SMEs and to show that the indicators significantly correlate with the environmental performance of the SMEs. In order to test this hypothesis, a survey-questionnaire was designed and administered among SMEs covering six industrial sectors in the Philippines. Based on the survey responses, a Gap analysis between the environmental performances of SMEs and state-of-the-art companies was performed. The Gap analysis showed that environmental indicators were indeed able to capture the features of actual environmental performance.Further, a structural equation model was proposed and validated. It yielded a significant linkage between the environmental indicators and environmental performance.  相似文献   

6.
In this study, the distribution, transfer and fate of both polychlorinated biphenyls (PCBs) and cyanotoxins via phytoplankton routes were systematically investigated in two Chinese lakes. Results indicated that PCB adsorption/bioaccumulation dynamics has significantly positive correlations with the biomass of green alga and diatoms. Total lipid content of phytoplankton is the major factor that influences PCB adsorption/bioaccumulation. Cyanobacterial blooms with relatively lower lipid content could also absorb high amount of PCBs due to their high cell density in the water columns, and this process was proposed as major route for the transfer of PCBs in Chinese eutrophic freshwater. According to these findings, a novel route on fates of PCBs via phytoplankton and a green bioadsorption concept were proposed and confirmed. In the practice of mechanical collections of bloom biomass from Lake Taihu, cyanotoxin/cyanobacteria and PCBs were found to be removed simultaneously very efficiently followed this theory.  相似文献   

7.
The amount of rainfall in Mazandaran province of Northern Iran is high. Mazandaran has man-made water reservoirs called Ab-bandan, to collect rainfall for irrigating rice farms during the growing seasons. However, rice farms face water scarcity because only a small amount of rainfall is being stored in Ab-bandans, while either the remaining water runs off into the sea, or causes water-logging or flooding. This research addresses Ab-bandans governance gaps in the Mazandaran province, using the ‘Multi-level Governance Framework’ introduced by the Organization for Economic Co-operation and Development (OECD). A modified Delphi technique with face-to-face interviews and a ranking round is used to identify Ab-bandans governance gaps. The identified gaps are classified into seven categories by applying the OECD's framework. In each of the categories there is one most important gap: the lack of a specific law for Ab-bandans, lack of long-term and strategic planning, low recognition of Ab-bandans at the national level, insufficient budget, lack of water user associations, lack of research in practice, and lack of using technology. The findings show that lack of a specific law for Ab-bandans in the country's water law is the most acute gap of all. In addition, the analysis highlights the fact that the policy category is the most critical one. The identified gaps are interlinked and exacerbate each other, therefore, a holistic perspective is needed to understand and resolve them. This study recommends a reform in the country’s water law, improved linkage between levels of government, co-operation among organizations involved in Ab-bandans management, and participation of local stakeholders in planning.  相似文献   

8.
Fairness is a relative concept with multiple, subjective and competing notions of what it is, how to achieve it, and for which beneficiaries. Fairtrade International's collaborative efforts to develop a standard to certify Fairtrade Carbon Credits (FCCs) brought together multiple stakeholders in a deliberative context. This paper uses Q methodology to empirically assess the notions of fairness this wider consultation group held. Three distinct ‘factors’ (or perspectives) are identified, and discussed in relation to a multi-dimensional framework for exploring fairness. The first factor prioritises development delivered through organisations, participation in decision-making and use of minimum prices to adjust trade imbalances. The second factor conceptualises a non-exclusive approach maximising generation and sales of FCCs, involving a commodity chain where everyone performs their optimum function with financial transparency and information-sharing to facilitate negotiations. The third factor involves minimising intervention, allowing carbon commodity chains and project set-ups to function efficiently, and make their own adjustments to enhance benefits access and quality received by beneficiaries. The three factors reflect debates within carbon and fair trade spheres about who should be playing which roles, who should be accessing which benefits, and how people should be supported to interact on an uneven playing field. Communicating findings to standards organisations enables a more open and inclusive policy process. Our research provides a critical reflection on these plural notions of fairness, identifying areas of (dis)agreement within the FCC dialogue, and provides a wider, yet manageable, set of inputs for supporting the FCC process during its inception and subsequent implementation. Clearer definitions of “fairness” are also useful for standards organisations in reviewing ex post whether “fairness” goals have been met.  相似文献   

9.
直流电对硝化细菌活性的影响   总被引:3,自引:1,他引:3       下载免费PDF全文
研究外加直流电分别对悬浮和固定膜二种存在状态的硝化细菌代谢活性和硝化效率的影响 .小于 2 5A·m-2 的直流电对游离细菌硝化氨氮没有影响 ,5A·m-2 以上的电流开始抑制细菌的硝化作用 .生物膜具有较强的抗电能力 ,15A·m-2 的直流电仅使氨氮的硝化速率降低 2 0 % .另外 ,电流对生物膜的持菌量影响差异较大 .当电流密度为 15A·m-2 时 ,负极的持菌量减少 90 %以上 ,正极减少 5 8% ,而电极中间填料的持菌量仅减少 8% .测量生物膜中磷脂含量发现 ,正极表面生物膜中活细菌比重最小 ,正极其次 ,填料表面生物膜中活细菌含量最高  相似文献   

10.
11.
Structural changes in the global commodity markets have particularly serious implications to the food security of import-dependent countries. Adapting importation policy to that global change is essential given that many commodities are imported to fulfill domestic demand. Using Singapore as a case study, this paper examines rice (Oryza) import allocation for seeking adaptive measures, which have broad implications to import-dependent countries. Its quarterly trade data (between 1999 and 2008) have been analyzed using an almost ideal demand system (AIDS) model. Our findings in respect to expenditure elasticity reveal that Singapore will continue its importation from its current range of suppliers, and add new import sources, fulfilling its national diversification strategy. New sources that located in different regions will also strengthen Singapore’s regional diversification strategy. Both national and regional diversification strategies enable any country to tap into associative import sources when unfavorable events deplete supply from a normally preferred supplier. In addition, the results in respect to own-price elasticity suggest that Thailand is Singapore’s primary preferred source while other exporters are secondary suppliers. Supported by the outputs of cross-price elasticity, secondary sources are substitutable. Within a diversified import portfolio, their competitive relationship gives an import-dependent country a strategic position to hedge against price manipulation and escalation, and to substitute expensive suppliers with cheaper alternatives. For these reasons, an import diversification policy is recommended both as an adaptive measure in response to the global change in commodity markets and, at the same time, as a mean for sustaining food security in import-dependent countries.  相似文献   

12.
We have started a multicentre trial to study the possibilities of first-trimester maternal serum screening for fetal chromosomal abnormalities. Maternal blood samples were obtained before 13 weeks of gestation. We present the preliminary results of the first 950 patients on alpha-fetoprotein (AFP). Results on cancer antigen 125 (CA 125) in Down's syndrome and normal pregnancies are also presented. We conclude that the results on AFP are promising and that CA 125 might be predictive for fetal Down's syndrome.  相似文献   

13.
《Journal of Cleaner Production》2007,15(13-14):1359-1372
This paper mostly deals with the role of energy, matter and information flows within both environmental and human-dominated systems. Sustainable growth and development of both kinds of systems require optimum use of available resources for maximum power output, as suggested by Lotka's Maximum Power Principle [Lotka AJ. Contribution to the energetics of evolution. In: Proceedings of the national academy of sciences of the United States of America, vol. 8. 1922, p. 147–50; Lotka AJ. Natural selection as a physical principle. In: Proceedings of the national academy of sciences of the United States of America, vol. 8. 1922, p. 151–5.], recently restated by Odum [Odum HT. Maximum power and efficiency: a rebuttal. Ecol Model 1983;20:71–82; Odum HT. Environmental accounting. Emergy and environmental decision making. N.Y.: John Wiley & Sons; 1996.] as Maximum Em-Power Principle within the framework of his Emergy Synthesis approach. In times of declining resources, this principle translates into increased efficiency and optimum use of any kind of waste and co-products. Ecosystems and any self-organizing systems always apply this strategy and their selection–evolution mechanisms are based on their ability of growing on any untapped resource available. In order to do so, they increase the number of components and patterns for resource degradation in order to optimize the resource throughput and power output. Such a strategy also applies to human-dominated, economic systems, where the ability of dealing with co-products and wastes by means of appropriate designs as well as reuse and recycling processes may lead to “zero-emission” patterns (increased complexity, optimal resource throughput, minimization of emissions, resource exchange among system's components) and be the key for successful and sustainable development. In this paper Life Cycle Assessment and Emergy Synthesis approaches are suggested as joint tools for qualitative and quantitative evaluation of progresses towards industrial symbiosis and more sustainable production and consumption patterns within a zero emission framework.  相似文献   

14.
The Pollution Prevention 1997: A National Progress Report identifies pollution prevention initiatives as potentially the most effective for reducing risks to human health and the environment, as well as the most cost-effective method of environmental protection. So it is no surprise that much of the implementation of pollution prevention by local governments has been driven due to the cost savings it provides. Pollution prevention initiatives have been proven to reduce costs, improve efficiency, reduce risk, reduce liability, and provide a safer work environment. However, as many local governments have experienced budget and resource reductions, their pollution prevention programs have been impacted. Local governments, working to continue pollution prevention initiatives in spite of declining budgets, have had to change their approaches, be creative, and innovate. Montgomery County, Maryland has implemented a number of pollution prevention strategies for its own County operations. The linkages established between cost savings they achieve and environmental benefits provided have been used to continue to expand the County's pollution prevention efforts. This paper provides an overview of the pollution prevention measures and approaches that have been implemented in Montgomery County for its internal operations.  相似文献   

15.
16.
Lemurs are the most olfactory-oriented of primates, yet there is still only a basic level of understanding of what their scent marks communicate. We analyzed scent secretions from Milne-Edwards' sifakas (Propithecus edwardsi) collected in their natural habitat of Ranomafana National Park, Madagascar. We sought to test whether the scent mark could signal genetic relatedness in addition to species, sex, season, and individuality. We not only found correlations (r 2?=?0.38, P?=?0.017) between the total olfactory fingerprint and genetic relatedness but also between relatedness and specific components of the odor, despite the complex environmental signals from differences in diet and behavior in a natural setting. To the best of our knowledge, this is the first demonstration of an association between genetic relatedness and chemical communication in a wild primate population. Furthermore, we found a variety of compounds that were specific to each sex and each sampling period. This research shows that scent marks could act as a remote signal to avoid inbreeding, optimize mating opportunities, and potentially aid kin selection.  相似文献   

17.
While behavioural plasticity is considered an adaptation to fluctuating social and environmental conditions, many animals also display a high level of individual consistency in their behaviour over time or across contexts (generally termed ‘personality’). However, studies of animal personalities that include sexual behaviour, or functionally distinct but correlated traits, are relatively scarce. In this study, we tested for individual behavioural consistency in courtship and exploratory behaviour in male guppies (Poecilia reticulata) in two light environments (high vs. low light intensity). Based on previous work on guppies, we predicted that males would modify their behaviour from sneak mating tactics to courtship displays under low light conditions, but also that the rank orders of courtship effort would remain unchanged (i.e. highly sexually active individuals would display relatively high levels of courtship under both light regimes). We also tested for correlations between courtship and exploratory behaviour, predicting that males that had high display rates would also be more likely to approach a novel object. Although males showed significant consistency in their exploratory and mating behaviour over time (1 week), we found no evidence that these traits constituted a behavioural syndrome. Furthermore, in contrast to previous work, we found no overall effect of the light environment on any of the behaviours measured, although males responded to the treatment on an individual-level basis, as reflected by a significant individual-by-environment interaction. The future challenge is to investigate how individual consistency across different environmental contexts relates to male reproductive success.  相似文献   

18.
19.
2-Phase anaerobic digestion (AD), where the acidogenic phase was operated at 2 day hydraulic retention time (HRT) and the methanogenic phase at 10 days HRT, had been evaluated to determine if it could provide higher organic reduction and methane production than the conventional single-stage AD (also operated at 12 days HRT). 454 pyrosequencing was performed to determine and compare the microbial communities. The acidogenic reactor of the 2-phase system yielded a unique bacterial community of the lowest richness and diversity, while bacterial profiles of the methanogenic reactor closely followed the single-stage reactor. All reactors were predominated by hydrogenotrophic methanogens, mainly Methanolinea. Unusually, the acidogenic reactor contributed up to 24% of total methane production in the 2-phase system. This could be explained by the presence of Methanosarcina and Methanobrevibacter, and their activities could also help regulate reactor alkalinity during high loading conditions through carbon dioxide production. The enrichment of hydrolytic and acidogenic Porphyromonadaceae, Prevotellaceae, Ruminococcaceae and unclassified Bacteroidetes in the acidogenic reactor would have contributed to the improved sludge volatile solids degradation, and ultimately the overall 2-phase system''s performance. Syntrophic acetogenic microorganisms were absent in the acidogenic reactor but present in the downstream methanogenic reactor, indicating the retention of various metabolic pathways also found in a single-stage system. The determination of key microorganisms further expands our understanding of the complex biological functions in AD process.  相似文献   

20.
The objective of this study was to explore women's attitudes towards prenatal diagnosis of trisomy 21 and to examine some of the factors possibly responsible for these attitudes before implementing in real practice serological screening of pregnant women at risk for trisomy 21. We carried out a telephone survey on a representative sample of women who had recently had a normal livebirth delivery in the Marseille district in 1990. The participation rate was 80 per cent and the average age of the mothers was 28-9 years. Among the 514 women interviewed, 78 per cent stated that they would ask for an amniocentesis for a 1 per cent risk of trisomy 21 at their next pregnancy. When adjusting for confounding factors, the decision to have or not to have an amniocentesis was found to depend not only on the women's attitude towards induced abortion, but also on their understanding of the risk involved and on the social context (knowing a handicapped child, discussion with the father). It also depended on the women's age and on what they knew about amniocentesis from the medical point of view. The risk of miscarriage can influence a woman's choice but this objection was not found to affect the women's decisions significantly in our survey. The data showed the existence of a high potential demand for fetal karyotyping.  相似文献   

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