G. J. Mackenzie

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In pelagic carbonate sediments, the degree to which the dC values of inorganic and organic fractions co-vary has been used to interpret rates of production, burial and decomposition of organic carbon. This relationship is relatively consistent through time, permitting estimates of organic carbon production and preservation. However, as the majority of(More)
In order to better understand the feeding ecology and timing of egg formation and regional geographic range of wading birds from South Florida, the δ13C and δ18O values of eggshells and the δ13C and δ15N values of the organic matrix, were measured in ~400 samples, representing nine species of waterbirds. Results reveal major differences between the(More)
THE recognition of the importance of the sympathetic nervous system in the control of the systemic arterial blood pressure has stimulated the search for therapeutically useful sympathoadrenergic blocking agents that may be of use in the diagnosis and treatment of hypertensive vascular disease. Numerous agents of diverse chemical structure have been(More)
The development of a mild metabolic acidosis during general anaesthesia has been reported by many workers (Bunker, Brewster, Smith, and Beecher, 1952; Pontius, Watkins, Manheim, Allen, Sauvage, and Gross, 1958; Robertson and Frazer, 1958). Likewise the early onset of a slight but definite metabolic acidosis has been observed in dogs during cyclopropane(More)