Georgina McLeod

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A novel compound, for which the trivial name tunichrome is proposed, was isolated from the vanadium-rich blood cells of the tunicate Ascidia niga. Preliminary structural studies suggest a molecular weight of about 390, the presence of conjugated vinyl groups, and an acidic group, possibly carboxyl, with an apparent pKa of 3.0. Elements C, H, N and O(More)
Action spectra for delayed light production by several algae were determined from 250 to 750 mmicro incident light. In the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. Blue-green algae had a maximum at 620 mmicro, red algae at 550 mmicro, whereas green and brown algae(More)
The y-2 mutant of Chlamydomonas reinhardi differs from the wild type in being unable to synthesize chlorophyll in the dark and in a requirement for catalytic amounts of light for organotrophic growth. Light-grown y-2 cells given acetate are capable of the equivalent of 9 to 10 divisions when placed in darkness. Cultures adapt gradually to dim white or(More)
In humans and animals, ossifying fibroma is a benign neoplasm that most frequently affects the mandible, often resulting in cosmetic deformities and malocclusion. It is considered rare in animals and most frequently affects young horses. A surgical biopsy of a solitary mass located beneath the gingiva in the right maxillary region, which had overgrown teeth(More)
The Emerson effect was observed as an enhancement of photosynthesis in long-wavelength red light when beams of shorter wavelength were added. Two light beams of wavelengths 650 and 694 mmicro, respectively, when presented together, gave a photosynthetic rate higher than the sum of the rates obtained separately. The amount of enhancement of photosynthesis(More)
Brewing fermentations have traditionally been undertaken without the use of mechanical agitation, with mixing being provided only by the fluid motion induced by the CO(2) evolved during the batch process. This approach has largely been maintained because of the belief in industry that rotating agitators would damage the yeast. Recent studies have questioned(More)
The intracellular pH of intact blood cells of the tunicate Ascidia nigra was measured by transmembrane equilibration of [14C] methylamine. The pH of unfractionated blood cells is 7.39 +/- 1.10. The pH of vanadocytes, determined in a fractionation study, is 7.2. Previously used methods, in which pH values less than 3.0 are inferred from cell lysis or vital(More)