6 resultados para Volk, Richard R. (Rick)
em University of Queensland eSpace - Australia
Resumo:
This paper examines trends in the practice of Operations Management and in teaching the field in major Business Schools. Operations Management has been defined as the design and management of transformation processes that create value for society. The operations function is the one function directly involved in that transformation, and hence is directly responsible for the activities that justify the existence of the firm, both economically and as a value-creating organization in society. The top rated schools in Operations Management are the top-rated research-intensive Business Schools in the world. Operations Management is an area that has been undergoing rapid change in response to changes in business practices worldwide. It is at the heart of changes of which the AACSB report Management Education at Risk, August 2002 (p 20), comments of Business Schools in general: ‘With regard to global relevance (of Business Schools), the complex opportunities and challenges that emanate from the world scope of operations, outsourcing, supply chains, partnerships, and financial and consumer markets – all linked in real time through the Internet – are not reflected adequately in curricula and learning approaches.’ Products, and even services, depend increasingly on advanced technology. This is true globally and especially so for countries in South East and East Asia, from which Australian Universities draw a significant number of students. Services operations management has become much more important, while there are both educational and industrial needs in management science or operations research.
Resumo:
Failure to express soluble proteins in bacteria is mainly attributed to the properties of the target protein itself, as well as the choice of the vector, the purification tag and the linker between the tag and protein, and codon usage. The expression of proteins with fusion tags to facilitate subsequent purification steps is a widely used procedure in the production of recombinant proteins. However, the additional residues can affect the properties of the protein; therefore, it is often desirable to remove the tag after purification. This is usually done by engineering a cleavage site between the tag and the encoded protein that is recognised by a site-specific protease, such as the one from tobacco etch virus (TEV). In this study, we investigated the effect of four different tags on the bacterial expression and solubility of nine mouse proteins. Two of the four engineered constructs contained hexahistidine tags with either a long or short linker. The other two constructs contained a TEV cleavage site engineered into the linker region. Our data show that inclusion of the TEV recognition site directly downstream of the recombination site of the Invitrogen Gateway vector resulted, in a loss of solubility of the nine mouse proteins. Our work suggests that one needs to be very careful when making modifications to expression vectors and combining different affinity and fusion tags and cleavage sites: (c) 2006 Elsevier Inc. All rights reserved.
Resumo:
The chytrid fungus Batrachochytrium dendrobatidis has been implicated in the decline and extinction of numerous frog species worldwide. In Queensland, Australia, it has been proposed as the cause of the decline or apparent extinction of at least 14 high-elevation rainforest frog species. One of these, Taudactylus eungellensis, disappeared from rainforest streams in Eungella National Park in 1985-1986, but a few remnant populations were subsequently discovered. Here, we report the analysis of B. dendrobatidis infections in toe tips of T. eungellensis and sympatric species collected in a mark-recapture study between 1994 and 1998. This longitudinal study of the fungus in individually marked frogs sheds new light on the effect of this threatening infectious process in field, as distinct from laboratory, conditions. We found a seasonal peak of infection in the cooler months, with no evidence of interannual variation. The overall prevalence of infection was 18% in T. eungellensis and 28% in Litoria wilcoxii/jungguy, a sympatric frog that appeared not to decline in 1985-1986. No infection was found in any of the other sympatric species. Most importantly, we found no consistent evidence of lower survival in T. eungellensis that were infected at the time of first capture, compared with uninfected individuals. These results refute the hypothesis that remnant populations of T. eungellensis recovered after a B. dendrobatidis epidemic because the pathogen had disappeared. They show that populations of T. eungellensis now persist with stable, endemic infections of B. dendrobatidis.