995 resultados para Historical site


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A fluorescent DNA probe containing an anthracene group attached via an anucleosidic linker can identify all four DNA bases at a single site as well as the epigenetic modification C/5-MeC via a hybridisation sensing assay.

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The construction industry is inherently hazardous, with a significant number of accidents and incidents occurring, particularly on confined construction sites. This research identifies, clarifies and tabulates the various managerial health and safety issues encountered on confined construction sites, based on a qualitative approach, to aid in the management of the complex health and safety concerns. The methodology is based on qualitative research incorporating case studies, interviews, causal loop diagrams and mind mapping. The key findings in the managerial issues in the management of health and safety on confined construction sites can be summarised as follows; (1) A lack of space, (2) Increased management of site personnel, (3) Overcrowding of the work place. The implication for the industry is that due to the sustained development of urban centres on a global scale, coupled with the increasing complexity of architectural designs, the majority of on-site project management professionals are faced with the onerous task of completing often intricate designs within a limited spatial environment, under strict health and safety parameters. The value of such research is to aid management professionals successfully identify the various managerial issues highlighted, resulting in the successful management of health and safety on a confined construction site.

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The construction industry is inherently risky, with a significant number of accidents and disasters occurring, particularly on confined construction sites. This research investigates and identifies the various issues affecting successful management of health and safety in confined construction sites. The rationale is that identifying the issues would assist the management of health and safety particularly in inner city centres which are mostly confined sites. Using empiricism epistemology, the methodology was based on qualitative research approach by means of multiple case studies in three different geographical locations of Ireland, UK and USA. Data on each case study were collected through individual interviews and focus group discussion with project participants. The findings suggest that three core issues are the underlying factors affecting management of health and safety on confined construction sites. It include, (i) lack of space, (ii) problem of co-ordination and management of site personnel, and (iii) overcrowding of workplace. The implication of this is that project teams and their organisations should see project processes from a holistic point of view, as a unified single system, where quick intervention in solving a particular issue should be the norm, so as not to adversely affect interrelated sequence of events in project operations. Proactive strategies should be devised to mitigate these issues and may include detail project programming, space management, effective constructability review and efficient co-ordination of personnel, plant and materials among others. The value of this research is to aid management and operation of brownfield sites by identifying issues impacting on health and safety management in project process.

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This paper challenges the recent suggestion that a new financial elite has evolved which is able to capture substantial profit shares for itself. Specifically, it questions the assumption that new groups of financial intermediaries have increased in significance primarily because there is evidence that various types of financial speculators have played a similarly extensive role at several junctures of economic development. The paper then develops the alternative hypothesis that, rather than being a recent development, the rise of these financial intermediaries is a cyclical phenomenon which is linked to specific regimes of capital accumulation. The hypothesis is underpinned by historical data from the US National Income and Product Accounts for the period from 1930 to 2000, which suggest that the activities of `mainstream' financial intermediaries have been accompanied by the frequently countercyclical activities of a `speculative' sector of security and commodity brokers. Based on the combination of this qualitative and quantitative evidence, the paper concludes that the rise of a speculative financial sector is a potentially recurrent phenomenon which is linked to periods of economic restructuring and turmoil.

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Galactokinase catalyses the site-and stereospecific phosphorylation of galactose at the expense of ATP. The specificity of bacterial galactokinase enzymes can be broadened by alteration of a tyrosine residue to a histidine. The effects of altering the equivalent residue in human galactokinase (Tyr379) were investigated by testing all 19 possible variants. All of these alterations, except Y379P, resulted in soluble protein on expression in Escherichia coli and all the soluble variants could catalyse the phosphorylation of galactose, except Y379A and Y379E. The variants Y379C, Y379K, Y379R, Y379S and Y379W were all able to catalyse the phosphorylation of a variety of monosaccharides, including ones that are not acted on by the wild-type enzyme. Novel substrates for these variant galactokinases included D-mannose and D-fructose. The latter monosaccharide is presumed to react in the pyranose configuration. Molecular modelling suggested that the alterations do not cause changes to the overall structure of the enzyme. However, alteration of Tyr379 increases the flexibility of the peptide backbone in regions surrounding the active site. Therefore, it is proposed that alteration of Tyr379 affects the substrate specificity by the propagation of changes in flexibility to the active site, permitting a broader range of compounds to be accommodated.

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Thorstein Veblen was a turn of the 20th century American economist concerned with the implications of financial capitalists directing the means of production. Veblen proposed that the rationality of "material science" as practiced by the "production engineers" is fundamentally different from the rationality of market capitalism. If this claim is valid, our previous contentions regarding accounting, as a facilitating technology, for administrative evil warrant reconsideration. Veblen's position provides a historical perspective on one dimension of administrative evil that is generally unquestionably accepted, especially within accounting. That is, technology, such as accounting and the related information systems, is amoral, and it is only through ideologically instigated applications that any moral value accrues. We discuss administrative evil and the role of instrumental rationality generally, and accounting specifically, in creating it. Veblen's characterization of financial capitalism and production engineers and his arguments for the primacy of economic efficiency versus "pecuniary gain" provide a basis for evaluating the legitimating action. We consider how Veblen's work relates to notions of instrumental rationality and then undertake a critical assessment of the ideas. Some of Veblen's ideas, while utopian, might be seen as an elixir for the detrimental influences of financial capital; however, at best, they provide a placebo for the ills of administrative evil and, as such, do not provide an amoral basis for legitimating the associated accounting systems.

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Galactokinase catalyses the phosphorylation of galactose at the expense of ATP. Like other members of the GHMP family of kinases it is postulated to function through an active site base mechanism in which Asp-186 abstracts a proton from galactose. This asparate residue was altered to alanine and to asparagine by site-directed mutagenesis of the corresponding gene. This resulted in variant enzyme with no detectable galactokinase activity. Alteration of Arg-37, which lies adjacent to Asp-186 and is postulated to assist the catalytic base, to lysine resulted in an active enzyme. However, alteration of this residue to glutamate abolished activity. All the variant enzymes, except the arginine to lysine substitution, were structurally unstable (as judged by native gel electrophoresis in the presence of urea) compared to the wild type. This suggests that the lack of activity results from this structural instability, in addition to any direct effects on the catalytic mechanism. Computational estimations of the pK(a) values of the arginine and aspartate residues, suggest that Arg-37 remains protonated throughout the catalytic cycle whereas Asp-186 has an abnormally high pK(a) value (7.18). Quantum mechanics/molecular mechanics (QM/MM) calculations suggest that Asp-186 moves closer to the galactose molecule during catalysis. The experimental and theoretical studies presented here argue for a mechanism in which the C-1-OH bond in the sugar is weakened by the presence of Asp-186 thus facilitating nucleophilic attack by the oxygen atom on the gamma-phosphorus of ATP.

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Reprinted in Trevor Barnes and Derek Gregory (eds), Reading Human Geography: The Poetics and Politics of Inquiry, (London: Arnold, 1997), pp. 27-48