Helena Campbell

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High rate algal ponds (HRAPs) are shallow, paddlewheel-mixed open raceway ponds that are an efficient and cost-effective upgrade for the conventional wastewater treatment ponds used by communities and farms the world over. HRAPs provide improved natural disinfection and nutrient removal and can be further enhanced by carbon dioxide (CO2) addition to promote(More)
[1] This paper reviews developments in our understanding of the state of the Antarctic and Southern Ocean climate and its relation to the global climate system over the last few millennia. Climate over this and earlier periods has not been stable, as evidenced by the occurrence of abrupt changes in atmospheric circulation and temperature recorded in(More)
OBJECTIVES To examine whether, from a National Health Service (NHS) and local authority social services' viewpoint, a hospital-at-home service was cost saving compared with conventional inpatient care. METHODS The subjects of this part-retrospective and part-prospective cost analysis were 51 elderly medical and orthopaedic surgical patients assessed at(More)
New U-Pb dating of detrital zircon and geochemical features of Permian-Mesozoic arcderived volcanic rocks and volcaniclastic turbidites (greywackes), when compared to the volcanic rocks associated with unconformable Late Cretaceous shallow-water sediments, reveal that subduction in New Caledonia, once thought to be extinct in the Late Jurassic (ca. 150 Ma),(More)
Natural family planning (NFP) tends to be considered as a matter of chance resulting in unplanned pregnancies and large families. A World Health Organization (WHO) multicenter trial of the ovulation method of NFP was undertaken during 1975-79 with the primary objective of determining what proportion of women of many different cultures could be taught to(More)