Daniel B. Murphy

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Microtubules can adjust their length by the mechanism of dynamic instability, that is by switching between phases of growth and shrinkage. Thus far this phenomenon has been studied with microtubules that contain several components, that is, a mixture of tubulin isoforms, with or without a mixture of microtubule-associated proteins (MAPs), which can act as(More)
A study of the IncJ plasmid R391 confirmed a low frequency of transfer between recombination proficient (recA+) Escherichia coli (10(-5) donor -1). Reanalysis of its transfer to recombination deficient (recA) E. coli revealed an equivalent transfer frequency to and from all mutants tested. Extrachromosomal DNA could not be detected in either recA+ or recA(More)
The incompatibility between the chromosomally integrating, conjugative transposon-like, IncJ elements R997 (ampicillin resistant) and R391 (kanamycin resistant) was examined by constructing strains harbouring both elements. Unusually, recA(+) strains harbouring the resistance determinants of both elements could be isolated but all strains lacked detectable(More)
The integration site(s) of the IncJ element, R391, was localised to a specific region of the Escherichia coli chromosome, between the uxuA and serB loci (98.0-99.5 min), using classical Hfr mapping techniques. F-prime plasmid hosts, diploid for regions spanning the E. coli chromosome, were used as recipients in R391 and R997 conjugal transfer assays.(More)
Use of commercially available urea differentiation disks is a rapid and convenient means of determining the urease activity of mycobacteria. In the study performed, paper disks containing Ewing's Urea R Broth were compared with two other methods of testing for urease production. Over 1,500 tests were performed with recent patient isolates from which at(More)
The complexity of vehicle-pedestrian collisions necessitates extensive validation of pedestrian computational models. While body components can be individually simulated, overall validation of human pedestrian models requires full-scale testing with post mortem human surrogates (PMHS). This paper presents the development of a full-scale pedestrian impact(More)
Patterned illumination using a digital micromirror device (DMD) is a powerful tool for optogenetics. Compared to a scanning laser, DMDs are inexpensive and can easily create complex illumination patterns. Combining these complex spatiotemporal illumination patterns with optogenetics allows DMD-equipped microscopes to probe neural circuits by selectively(More)
Vertebrate cells contain biochemical and genetic isotypes of tubulin which are expressed in unique combinations in different tissues and cell types. To determine if mixtures of tubulin isotypes assemblein vitro to form different classes of microtubules, we analyzed the composition of microtubule copolymers assembled from mixtures of chicken brain and(More)
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