Ian Crowlesmith

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This thesaurus-based search system uses automatic indexing, RDF-based querying, and concept-based visualization of results to support exploration of large online document repositories. Innovative research institutes rely on the availability of complete and accurate information about new research and development. Information providers such as Elsevier make(More)
The exploration of large information spaces is a difficult task, especially if the user is not familiar with the terminology used to describe information. Conceptual models of a domain in terms of thesauri or ontologies can leverage this problem to some extend. In order to be useful, there is a need for interactive tools for exploring large information sets(More)
Thin-section electron micrographs of plasmolyzed Salmonella typhimurium infected with bacteriophage P22 demonstrated that phage adsorbed to cells over sites of inner- and outer-membrane contact. Efforts were made to isolate such adsorption sites by infection of cells with 35S- and 32P-labeled phage and by separation of the membranes on sucrose gradients. At(More)
Thirty-eight mutants of R1, an R plasmid specifying the type IIIa (TEM) beta-lactamase, were isolated; these mutants are partially or totally unable to synthesize the type IIIa beta-lactamase. The loss of beta-lactamase activity was associated with a reduction in the level of penicillin resistance conferred by the mutants upon their host strain. At least(More)
The OmpA and OmpF proteins are major outer membrane proteins of Escherichia coli K12. Their precursors, the pro-OmpA and pro-OmpF proteins, have been detected in vivo in pulse-labelling experiments carried out with [35S]methionine at 25 degrees C. Wehn the pulse was at 37 degrees C, however, no precursors were detected. The pulse-labelled precursors were(More)
The rate of synthesis of the OmpA and OmpF proteins, two of the major outer membrane proteins of Escherichia coli K12, was determined. At 25 degrees C both proteins were translated at 6.5 amino acids/s, and the OmpF protein was translated at 15 amino acids/s at 37 degrees C. The former rate corresponded to a synthesis time of just over 50 s for both(More)
We describe here the isolation of a mutant derivative of the drug resistance factor R1 (Meynell and Datta, 1966) that carries a nonsense mutation in a gene determining resistance to penicillins. We have used this mutant R1 to isolate derivatives of Escherichia coli and Klebsiella pneumoniae that contain nonsense suppressors (Sup- strains) by screening(More)
A mutant of the R plasmid R1 which synthesizes a beta-lactamase with altered kinetic characteristics was isolated. The level of penicillin resistance specified by this plasmid was correctly predicted from the properties of the wild-type R1 according to a simple theoretical model published by Zimmermann and Rosselet (Antimicrob. Agents Chemother.(More)
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