Christopher A. D. Charles

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Large, abrupt shifts in the (l8)O/(16)O ratio found in Greenland ice must reflect real features of the climate system variability. These isotopic shifts can be viewed as a result of air temperature fluctuations, but determination of the cause of the changes-the most crucial issue for future climate concerns-requires a detailed understanding of the controls(More)
A record of oxygen isotopes in biogenic silica from a deep-sea sediment core from the Southern Ocean reveals that marine diatoms retain their primary isotopic composition after burial. As a result, the marine diatom record can be combined with data on coexisting planktonic foraminifera to monitor past surface temperature and isotopic composition of(More)
Records of carbon and nitrogen isotopes in biogenic silica and carbon isotopes in planktonic foraminifera from deep-sea sediment cores from the Southern Ocean reveal that the primary production during the last glacial maximum was lower than Holocene productivity. These observations conflict with the hypothesis that the low atmospheric carbon dioxide(More)
Decades-long records of the stable isotopic composition of coral skeletal cores were analyzed from four sites on the Mesoamerican Reef. Two of the sites exhibited baseline shifts in oxygen isotopic composition after known coral bleaching events. Changes in pH at the calcification site caused by a change in the associated symbiont community are invoked to(More)
[1] We have explored surface water mixing in the Lombok Strait through a bimonthly resolved surface water D 14 C time series reconstructed from a coral in the Lombok Strait that spans 1937 through 1990. The prebomb surface water D 14 C average is À60.5%, and individual samples range from À72% to 134%. The annual average postbomb maximum occurs in 1973 at(More)
BACKGROUND HIV/AIDS is a problem in developing countries including Jamaica. There are several studies dealing with HIV/AIDS in Jamaica but given the increasing rate of the infection, ongoing studies are necessary. AIMS This study examines the sexual behavior and attitude of non-HIV testers in Jamaica in order to provide research evidence that will direct(More)
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