Joseph A MacGregor

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Although establishing that a patient is suffering from dementia of the Alzheimer type initially reflects a clinician's opinion, neuropathological study is for the present the most definitive examination to confirm the clinical diagnosis of Alzheimer disease. We review several comprehensive publications attempting on a quantitative basis to differentiate the(More)
Several decades of ice-penetrating radar surveys of the Greenland and Antarctic ice sheets have observed numerous widespread internal reflections. Analysis of this radiostratigraphy has produced valuable insights into ice sheet dynamics and motivates additional mapping of these reflections. Here we present a comprehensive deep radiostratigraphy of the(More)
Recent peripheral thinning of the Greenland Ice Sheet is partly offset by interior thickening and is overprinted on its poorly constrained Holocene evolution. On the basis of the ice sheet's radiostratigraphy, ice flow in its interior is slower now than the average speed over the past nine millennia. Generally higher Holocene accumulation rates relative to(More)
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