953 resultados para efficiency and sustainability analysis
Resumo:
Increasing scrutiny from the wider community is contributing to a shift towards the delivery and operation of major projects that meets and maintains the sustainability priorities of the community. This is especially significant for large economic projects which have a global track record of social benefit shortfalls, cost overruns, and underestimation of risks. Major industrial and infrastructure projects that cost more than US$1 billion are typically called mega-projects. Globally, investment in mega-projects has exceeded $10 trillion in the last ten years. With so many projects in the pipeline -and many taking place in emerging economies – the effectiveness of the sustainability decision making process is particularly important. The purpose of this paper is to examine how the existing sustainability decision making processes and strategies address the potential challenges facing communities affected by mega-projects. It highlights issues with current operational level approaches to social sustainability assessment at the project level, and argues that to improve accountability and transparency of project outcomes, positive externalities that flow from goods and services provided by the social and cultural systems of the community must be incorporated into decision making.
Resumo:
The catalytic action of putrescine specific amine oxidases acting in tandem with 4-aminobutyraldehyde dehydrogenase is explored as a degradative pathway in Rhodococcus opacus. By limiting the nitrogen source, increased catalytic activity was induced leading to a coordinated response in the oxidative deamination of putrescine to 4-aminobutyraldehyde and subsequent dehydrogenation to 4-aminobutyrate. Isolating the dehydrogenase by ion exchange chromatography and gel filtration revealed that the enzyme acts principally on linear aliphatic aldehydes possessing an amino moiety. Michaelis-Menten kinetic analysis delivered a Michaelis constant (KM=0.014mM) and maximum rate (Vmax=11.2μmol/min/mg) for the conversion of 4-aminobutyraldehyde to 4-aminobutyrate. The dehydrogenase identified by MALDI-TOF mass spectrometric analysis (E value=0.031, 23% coverage) belongs to a functionally related genomic cluster that includes the amine oxidase, suggesting their association in a directed cell response. Key regulatory, stress and transport encoding genes have been identified, along with candidate dehydrogenases and transaminases for the further conversion of 4-aminobutyrate to succinate. Genomic analysis has revealed highly similar metabolic gene clustering among members of Actinobacteria, providing insight into putrescine degradation notably among Micrococcaceae, Rhodococci and Corynebacterium by a pathway that was previously uncharacterised in bacteria.
Resumo:
Two native copper-containing amine oxidases (EC 1.4.3.21) have been isolated from Rhodococcus opacus and reveal phenotypic plasticity and catalytic activity with respect to structurally diverse natural and synthetic amines. Altering the amine growth substrate has enabled tailored and targeted oxidase upreg-ulation, which with subsequent treatment by precipitation, ion exchange and gel filtration, achieved a 90–150 fold purification. MALDI-TOF mass spectrometric and genomic analysis has indicated multiple gene activation with complex biodegradation pathways and regulatory mechanisms. Additional post-purification characterisation has drawn on the use of carbonyl reagent and chelating agent inhibitors. Michaelis–Menten kinetics for common aliphatic and aromatic amine substrates and several structural analogues demonstrated a broad specificity and high affinity with Michaelis constants (K M) ranging from 0.1 to 0.9 mM for C 1 –C 5 aliphatic mono-amines and <0.2 mM for a range of aromatic amines. Potential exploitation of the enzymatic versatility of the two isolated oxidases in biosensing and bioprocessing is discussed.
Resumo:
L-Amino acid oxidases (LAAOs) are useful catalysts for the deracemisation of racemic amino acid sub-strates when combined with abiotic reductants. The gene nadB encoding the L-aspartate amino acid oxidase from Pseudomonas putida (PpLASPO) has been cloned and expressed in E. coli. The purified PpLASPO enzyme displayed a K M for l-aspartic acid of 2.26 mM and a k cat = 10.6 s −1 , with lower activity also displayed towards L-asparagine, for which pronounced substrate inhibition was also observed. The pH optimum of the enzyme was recorded at pH 7.4. The enzyme was stable for 60 min at up to 40 • C, but rapid losses in activity were observed at 50 • C. A mutational analysis of the enzyme, based on its sequence homology with the LASPO from E. coli of known structure, appeared to confirm roles in substrate binding or catalysis for residues His244, His351, Arg386 and Arg290 and also for Thr259 and Gln242. The high activity of the enzyme, and its promiscuous acceptance of both L-asparagine and L-glutamate as substrates, if with low activity, suggests that PpLASPO may provide a good model enzyme for evolution studies towards AAOs of altered or improved properties in the future.
Resumo:
This paper investigates the mutual relations of three current drivers of construction: lean construction, building information modelling and sustainability. These drivers are based on infrequently occurring changes, only incidentally simultaneous, in their respective domains. It is contended that the drivers are mutually supportive and thus synergistic. They are aligned in the sense that all require, promote or enable collaboration. It is argued that these three drivers should be implemented in a unified manner for rapid and robust improvements in construction industry performance and the quality of the constructed facilities and their benefits for stakeholders and wider society.
Resumo:
Asthma severity and control can be measured both subjectively and objectively. Traditionally asthma treatments have been individualised using symptoms and spirometry/peak flow. Increasingly treatment tailored in accordance with inflammatory markers (sputum eosinophil counts or fractional exhaled nitric oxide (FeNO) data) is advocated as an alternative strategy. The objective of this review was to evaluate the efficacy of tailoring asthma interventions based on inflammatory markers (sputum analysis and FeNO) in comparison with clinical symptoms (with or without spirometry/peak flow) for asthma-related outcomes in children and adults. Cochrane Airways Group Specialised Register of Trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and reference lists of articles were searched. The last searches were in February 2009. All randomised controlled comparisons of adjustment of asthma treatment based on sputum analysis or FeNO compared with traditional methods (primarily clinical symptoms and spirometry/peak flow) were selected. Results of searches were reviewed against predetermined criteria for inclusion. Relevant studies were selected, assessed and data extracted independently by at least two people. The trial authors were contacted for further information. Data were analysed as 'intervention received' and sensitivity analyses performed. Six (2 adults and 4 children/adolescent) studies utilising FeNO and three adult studies utilising sputum eosinophils were included. These studies had a degree of clinical heterogeneity including definition of asthma exacerbations, duration of study and variations in cut-off levels for percentage of sputum eosinophils and FeNO to alter management in each study. Adults who had treatment adjusted according to sputum eosinophils had a reduced number of exacerbations compared with the control group (52 vs. 77 patients with >=1 exacerbation in the study period; p=0.0006). There was no significant difference in exacerbations between groups for FeNO compared with controls. The daily dose of inhaled corticosteroids at the end of the study was decreased in adults whose treatment was based on FeNO in comparison with the control group (mean difference -450.03 mug, 95% CI -676.73 to -223.34; p<0.0001). However, children who had treatment adjusted according to FeNO had an increase in their mean daily dose of inhaled corticosteroids (mean difference 140.18 mug, 95% CI 28.94 to 251.42; p=0.014). It was concluded that tailoring of asthma treatment based on sputum eosinophils is effective in decreasing asthma exacerbations. However, tailoring of asthma treatment based on FeNO levels has not been shown to be effective in improving asthma outcomes in children and adults. At present, there is insufficient justification to advocate the routine use of either sputum analysis (due to technical expertise required) or FeNO in everyday clinical practice.
Resumo:
In vitro analyses of basement membrane invasiveness employing Matrigel (a murine tumor extract rich in basement membrane components) have been performed on human breast cancer model systems. Constitutive invasiveness of different human breast cancer (HBC) cell lines has been examined as well as regulation by steroid hormones, growth factors, and oncogenes. Carcinoma cells exhibiting a mesenchymal-like phenotype (vimentin expression, lack of cell border associated uvomorulin) show dramatically increased motility, invasiveness, and metastatic potential in nude mice. These findings support the hypothesis that epithelial to mesenchymal transition (EMT)-like events may be instrumental in the metastatic progression of human breast cancer. The MCF-7 subline MCF-7ADR appears to have undergone such a transition. The importance of such a transition may be reflected in the emergence of vimentin expression as an indicator of poor prognosis in HBC. Matrix degradation and laminin recognition are highlighted as potential targets for antimetastatic therapy, and analyses of laminin attachment and the matrix metalloproteinase (MMP) family in HBC cell lines are summarized. Matrigel-based assays have proved useful in the study of the molecular mechanisms of basement membrane invasiveness, their regulation in HBC cells, and their potential as targets for antimetastatic therapy.
Resumo:
How does globalization influence transitions toward more sustainable socio-technical regimes in the developing world? This paper argues that transformations of regimes, the networks and institutions governing technological and environmental practices in an industry, can be positively influenced by globalization but it depends on how global forces interact with local socio-political landscapes-the political-economic institutions, values, and regulations broadly guiding an economy and its relationship to the environment. We evaluate these relationships through a comparison of two kinds of socio-political landscapes-the neo-liberal export-led development model commonly found in the developing world and the uniquely Asian capitalist developmental state. We first show how the neo-liberal model overemphasizes the power of market forces to facilitate upgrading and more sustainable industrialization. We then argue that capitalist developmental states in East and Southeast Asia have been better able to harness global economic forces for technological and sustainability transitions through an openness to trade and investment and effective public-private institutions able to link cleaner technologies and environmental standards to production activities in firms. We buttress this argument with firm-level evidence showing the evolution of socio-technical regimes in two industries-cement and electronics. The case studies demonstrate how interactions with OECD firms can contribute to environmental technique effects provided the socio-political landscape is amenable to changes in an industry's regime. Ultimately, we find the process of transition to be complex and contingent; a hard slog not a leap frog toward a potentially more sustainable future. We close by considering the limitations on the capitalist developmental state model and with comments about what else needs to be learned about globalization's role in sustainability transitions.
Resumo:
Poor mine water management can lead to corporate, environmental and social risks. These risks become more pronounced as mining operations move into areas of water scarcity and/or increase climatic variability while also managing increased demand, lower ore grades and increased strip ratios. Therefore, it is vital that mine sites better understand these risks in order to implement management practices to address them. Systems models provide an effective approach to understand complex networks, particularly across multiple scales. Previous work has represented mine water interactions using systems model on a mine site scale. Here, we expand on that work by present an integrated tool that uses a systems modeling approach to represent mine water interactions on a site and regional scale and then analyses the risks associated with events stemming from those interactions. A case study is presented to represent three indicative corporate, environmental and social risks associated with a mine site that exists in a water scarce region. The tool is generic and flexible, and can be used in many scenarios to provide significant potential utility to the mining industry.