Joel P L Johnson

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Chromosome 22q11.2 deletion syndrome (22q11.2DS) is a result of a hemizygotic microdeletion that results in a variety of impairments in children including greater risk for psychiatric ailments in adulthood. We used high-resolution magnetic resonance imaging to accurately quantify the length and, for the first time, volume, of the cavum septum pellucidum(More)
[1] Amphitheater-headed valleys on Earth and Mars are often assumed to result from erosion by emerging spring water (i.e., seepage erosion or groundwater sapping) rather than by surface runoff. The origin of such valleys has implications for landscape evolution on Earth and the hydrologic cycle and associated potential for life on other planets. In this(More)
OBJECTIVE This pilot study provides firsthand feedback from medical students and residents in training regarding their perceptions of technology in medicine. METHOD The authors distributed an e-mail invitation to an anonymous Web-based survey to medical students and residents in two different U.S. training institutions. RESULTS Respondents unanimously(More)
The authors present the case of a 60-year-old woman with elaborate paranoid delusions and cognitive impairment found during a workup for atypical chest pain. Clinical evaluation revealed mild dementia, and radiography showed basal ganglia calcification consistent with Fahr's disease. She was treated with risperidone and transferred to a psychiatric(More)
Feedbacks between climate, erosion and tectonics influence the rates of chemical weathering reactions, which can consume atmospheric CO2 and modulate global climate. However, quantitative predictions for the coupling of these feedbacks are limited because the specific mechanisms by which climate controls erosion are poorly understood. Here we show that(More)
archaeological records indicate that awake craniot-omies in the form of trephination were successfully practiced long before the advent of general anesthesia. Skulls unearthed in Peru show complete healing in 55% of 214 patients. The possibility has been advanced that coca leaves may have allowed for trephination after cocaine-induced local anesthesia. In(More)
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