The American or Blood System The American system of grading wool was developed in the early 1800s when the native coarse-wooled sheep were being bred to finewooled Merino rams imported from Spain. It assumes that the offspring of the cross would have fleeces which were intermediate in fineness between the two parents. The wool grade is defined as the percentage of Merino blood carried by the sh...

The purpose was to compare capability of fluorine-18 fluorodeoxyglucose (FDG)-PET and thallium-201 (Tl)-SPECT for grading meningioma. This retrospective study was conducted as a case-control study under approval by the institutional review board. In the hospital information system, 67 patients (22 men and 45 women) who had both FDG-PET and Tl-SPECT preoperative examinations were found with hist...

BACKGROUND To assess the impact of a change in preclerkship grading system from Honors/Pass/Fail (H/P/F) to Pass/Fail (P/F) on University of California, San Diego (UCSD) medical students' academic performance. METHODS Academic performance of students in the classes of 2011 and 2012 (constant-grading classes) were collected and compared with performance of students in the class of 2013 (gradin...