Dave McConnell

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On theoretical grounds it is unlikely that the catalytic action of the enzyme carbonic anhydrase would be required for the precipitation of apatite in vitro. The presence of carbonic anhydrase in either active or inactivate form did not initiate precipitation in a metastable calcifying solution. It is unlikely that carbonate (or bicarbonate) ions are(More)
We report here on a sequence of 28 observations of the binary pulsar system PSR B1259−63/SS2883 at four radio frequencies made with the Australia Telescope Compact Array around the time of the 2000 periastron passage. Observations made on 2000 September 1 show that the apparent rotation measure (RM) of the pulsar reached a maximum of −14800 ± 1800 rad m−2,(More)
The mineral component of the marine green algal genus Halimeda is the orthorhombic calcium carbonate (aragonite); its presence appears to be a generic characteristic. Tydemania expeditionis also precipitates aragonite in contradistinction to species of the red alga Corallina wliich precipitate calcium carbonate of the hexagonal form (calcite). The analyses(More)
We present multi-color optical and two-frequency radio observations of the bright SAX event, GRB 990510. Neither the well-sampled optical decay, nor the radio observations are consistent with simple spherical afterglow models. The achromatic steepening in the optical band and the early decay of the radio afterglow, both occuring at t ∼ 1 day, are evidence(More)
In vitro experiments with saliva resulted in precipitation of a mineral substance (dahllite or carbonate hydroxyapatite) which is comparable in composition and crystal structure to oral calculus. Similar mineral substances were produced from synthetic solutions containing sodium phosphate and calcium chloride (in addition to a buffer) in the presence of(More)