94 resultados para possible hydrothermal vents


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Raman microscopy is used to investigate the spectral features of selected compounds known to be involved in the development of the eye disease age-related macular degeneration (AMD). Diagnostic features were identified in synthetic samples of these compounds and in a biological matrix. The study demonstrates the potential of Raman microscopy for the development of diagnostic markers of the onset of AMD. Copyright (C) 2008 John Wiley & Sons, Ltd.

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The first step of the mineralisation of fosfomycin by R. huakuii PMY1 is hydrolytic ring opening with the formation of (1R, 2R)-1,2-dihydroxypropylphosphonic acid. This phosphonic acid and its three stereoisomers were synthesised by chemical means and tested as their ammonium salts for mineralisation as evidenced by release of P-i. Only the (1R, 2R)-isomer was degraded. A number of salts of phosphonic acids such as (+/-)-1,2-epoxybutyl-, (+/-)-1,2-dihydroxyethyl-, 2-oxopropyl-, (+/-)-2-hydroxypropyl-, (+/-)-1-hydroxypropyl- and (+/-)-1-hydroxy-2-oxopropylphosphonic acid were synthesised chemically, but none supported growth. In vitro C-P bond cleavage activity was however detected with the last phosphonic acid. A mechanism involving phosphite had to be discarded as it could not be used as a phosphorus source. R. huakuii PMY1 grew well on (R)- and ( S)- lactic acid and hydroxyacetone, but less well on propionic acid and not on acetone or (R)- and (+/-)-1,2-propanediol. The Pi released from (1R, 2R)-1,2-dihydroxypropylphosphonic acid labelled with one oxygen-18 in the PO3H2 group did not stay long enough in the cells to allow complete exchange of O-18 for O-16 by enzymic turnover.

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There has been considerable interest in recent years in comparing the operation of social work services to children and families internationally, particularly between Australia, the United Kingdom and the United States. Reviewing the respective policy environments and drawing on recent research experience in these three nations the author speculates as to how such services may be placed to respond to a converging agenda to tackle the high social and economic costs of social exclusion. It is argued that a conspiracy of circumstances have led child and family social work away from its more general child welfare objectives of the past and created consolidation of functions in relation to child protection work. This has left services ill prepared to play a central role within a new and resurgent child welfare agenda.

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In the development of family policy under New Labour there has been a growing tendency to identify groups who are likely to be high in lifetime costs to the state. Investment in such groups is seen as crucial. Whilst the economic case for current investment is compelling, idenitiying one of these groups, ‘families with multiple problems’ raises complex research problems and ethical issues. Reseach indicates that families with multiple problems may be identified on the caseloads of child and family social worker and there are claims that key events such as the registration of a child on the child protection register may indicate such multiple problems. This offers new opportunities for child and family social work to embrace less incident based ways of working in favour of longer term provision of services to address longer term risks.