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Summary Triple cones were found in the retinas of 3 species of fishes indigenous to the Woods Hole area. The function of these triple cones can not be deduced from the behavior patterns of these fishes.We wish to thank Kathleen French for her advice and criticism in the preparation of this paper.  相似文献   
63.
Engineered gene circuits   总被引:23,自引:0,他引:23  
Hasty J  McMillen D  Collins JJ 《Nature》2002,420(6912):224-230
A central focus of postgenomic research will be to understand how cellular phenomena arise from the connectivity of genes and proteins. This connectivity generates molecular network diagrams that resemble complex electrical circuits, and a systematic understanding will require the development of a mathematical framework for describing the circuitry. From an engineering perspective, the natural path towards such a framework is the construction and analysis of the underlying submodules that constitute the network. Recent experimental advances in both sequencing and genetic engineering have made this approach feasible through the design and implementation of synthetic gene networks amenable to mathematical modelling and quantitative analysis. These developments have signalled the emergence of a gene circuit discipline, which provides a framework for predicting and evaluating the dynamics of cellular processes. Synthetic gene networks will also lead to new logical forms of cellular control, which could have important applications in functional genomics, nanotechnology, and gene and cell therapy.  相似文献   
64.
Plasmodium, human and Anopheles genomics and malaria   总被引:6,自引:0,他引:6  
Hoffman SL  Subramanian GM  Collins FH  Venter JC 《Nature》2002,415(6872):702-709
The Plasmodium spp. parasites that cause malaria are transmitted to humans by Anopheles spp. mosquitoes. Scientists have now amassed a great body of knowledge about the parasite, its mosquito vector and human host. Yet this year there will be 300-500 million new malaria infections and 1-3 million deaths caused by the disease. We believe that integrated analyses of genome sequence, DNA polymorphisms, and messenger RNA and protein expression profiles will lead to greater understanding of the molecular basis of vector-human and host-parasite interactions and provide strategies to build upon these insights to develop interventions to mitigate human morbidity and mortality from malaria.  相似文献   
65.
Evolving ideas of brain evolution   总被引:1,自引:0,他引:1  
Kaas JH  Collins CE 《Nature》2001,411(6834):141-142
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66.
Neanderthal DNA. Not just old but old and cold?   总被引:9,自引:0,他引:9  
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67.
Two systemic inquiries, based on soft systems methodology (SSM), into the potential for using community of practice (CoP) theory by an Australian-government created research and development corporation to change its knowledge management (KM) strategy, are reported. Key staff were engaged in the inquiry into how to build a third-order KM strategy based on CoPs; an exploration of key published work on CoPs yielded four SSM activity models—‘being a community practice system’; ‘doing the work of imagination sub-system’; ‘doing the work of alignment sub-system’ and ‘doing the work of engagement sub-system’. These models can be used as heuristics to aid the purposeful design of CoPs in other settings. SSM, enacted as a systemic inquiry, can be understood as a form of systemic action research, which was well equipped to deal with CoP theory and, when enacted participatively, can generate important systemic insights. The inquiry began the process of fostering an appreciation of third order KM but, on the evidence available, did not lead to on-going commitment to a CoPs-based KM strategy. Future research should acknowledge how the framing of research situations influences the research process, the importance of the design of practice change settings and the limited evidence for purposeful interventions leading to successful CoPs.  相似文献   
68.
In Part I of this two part paper we tried to elicit the ‘essence’ of the notion of interactional expertise by looking at its origins. In Part II we will look at the notion of contributory expertise. The exercise has been triggered by recent discussion of these concepts in this journal by Plaisance and Kennedy and by Goddiksen.  相似文献   
69.
Von Hippel-Lindau disease (VHL) is an autosomal dominant disorder with inherited susceptibility to various forms of cancer, including hemangioblastomas of the central nervous system, phaeochromocytomas, pancreatic malignancies, and renal cell carcinomas. Renal cell carcinomas constitute a particularly frequent cause of death in this disorder, occurring as bilateral and multifocal tumours, and presenting at an earlier age than in sporadic, non-familial cases of this tumour type. We report here that the VHL gene is linked to the locus encoding the human homologoue of the RAF1 oncogene, which maps to chromosome 3p25 (ref. 4). Crossovers with the VHL locus suggest that the defect responsible for the VHL phenotype is not a mutation in the RAF1 gene itself. An alternative or prior event to oncogene activation in tumour formation may be the inactivation of a putative 'tumour suppressor' which can be associated with both the inherited and sporadic forms of the cancer. Sporadic renal cell carcinomas have previously been associated with the loss of regions on chromosome 3p (refs 5, 6). Consequently, sporadic and VHL-associated forms of renal cell carcinoma might both result from alterations causing loss of function of the same 'tumour suppressor' gene on this chromosome.  相似文献   
70.
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