Worldwide, the design life of bridges can be extended by delivering repair and strengthening projects while meeting the challenge of keeping the bridge in service. Although this is a common ...characteristic of such international projects, there are significant differences between countries with regard to types of bridges and maintenance approaches. VSL International is active in the field of bridge repairs and strengthening in a worldwide capacity and adopts a variety of solutions to accommodate these to local conditions. This article will describe lessons learnt from a variety of projects which deal with the repair and strengthening of steel bridges, particularly cable-supported structures. Several international examples are described, in Mexico, Canada, the USA and France, where innovative solutions have been applied. These innovations focus on the unique combination of specialised temporary works, method of construction and cable technology.
Basic research in pattern formation is concerned with the generation of phenotypes and tissues. It can therefore lead to new tools for medical research. These include phenotypic screening assays, ...applications in tissue engineering, as well as general advances in biomedical knowledge. Our aim here is to discuss this emerging field with special reference to tools based on zebrafish developmental biology. We describe phenotypic screening assays being developed in our own and other labs. Our assays involve: (i) systemic or local administration of a test compound or drug to zebrafish in vivo; (ii) the subsequent detection or "readout" of a defined phenotypic change. A positive readout may result from binding of the test compound to a molecular target involved in a developmental pathway. We present preliminary data on assays for compounds that modulate skeletal patterning, bone turnover, immune responses, inflammation and early-life stress. The assays use live zebrafish embryos and larvae as well as adult fish undergoing caudal fin regeneration. We describe proof-of-concept studies on the localised targeting of compounds into regeneration blastemas using microcarriers. Zebrafish are cheaper to maintain than rodents, produce large numbers of transparent eggs, and some zebrafish assays could be scaled-up into medium and high throughput screens. However, advances in automation and imaging are required. Zebrafish cannot replace mammalian models in the drug development pipeline. Nevertheless, they can provide a cost-effective bridge between cell-based assays and mammalian whole-organism models.
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