Local patterns in human operant behavior and a behaving model to interrelate animal and human performances.

College students pressed buttons for points delivered according to molecular concurrent reinforcement contingencies similar to those used in previous experiments with animal subjects. Relative frequency of reinforcement and the relative and absolute durations of two reinforced patterns of button pressing were experimentally varied. Qualitative effects of all three variables resembled those obtained previously with animals.

Modified Thiersch operation for rectal prolapse. Technique and results.

Rectal prolapse is best treated by intra-abdominal or perineal procedures that either resect the redundant rectosigmoid colon or fix the rectum within the pelvis. We have found the Thiersch procedure to be adequate treatment in patients who are high risk or who have only mild to moderate prolapse of the rectum. Over the past 20 years, we have treated 15 patients with a modified Thiersch procedure, using a knitted Dacron vascular graft to encircle the anus.

The diagnosis of aortoiliac disease. A noninvasive femoral cuff technique.

An inexpensive femoral "cuff" developed in this noninvasive vascular laboratory allows pulse volume recordings and systolic pressure measurements of the femoral arteries. Using the parameters 1) femoral/brachial systolic pressure ratio, 2) wave amplitude, and 3) status of the dicrotic notch for assessment of results, it was found that the cuff correctly identified 59 of 62 limbs with at least 50% aortoiliac stenosis, with only two false-positive results, for an accuracy of 97%. The high, wide thigh cuff identified 57 of the 62 limbs, but had 45 false-positive results (77% accuracy).