David S. Packard

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Congenital vertical talus (CVT), also known as "rocker-bottom foot" deformity, is a dislocation of the talonavicular joint, with rigid dorsal dislocation of the navicular over the neck of the talus. This condition is usually associated with multiple other congenital deformities and only rarely is an isolated deformity. The reported familial cases are(More)
Preoperative angiography in 30 uncorrected clubfeet demonstrated abnormal vascular patterns in all but two limbs with hypoplasia or premature termination of the anterior tibial and medial plantar arteries in the remainder. Postoperative Doppler studies in nine of the limbs with abnormal vessels indicated that these arteries were present. We suggest that the(More)
Partial outlet obstruction of the rabbit bladder induces a rapid and significant increase in bladder mass. This increase in mass is associated with a variety of specific contractile dysfunctions, characterized by a marked decrease in the response to field stimulation (acting through the release of neurogenic transmitters). There is histological evidence(More)
This prospective study used pulsed color-flow Doppler sonography to determine differences in the presence and direction of flow through the dorsalis pedis, posterior tibial, and peroneal arteries in a group of children with clubfoot and a comparison group of controls. There was a statistically significant difference in the prevalence of deficient (absent or(More)
Three patients who had shortening or absence of the fibula were evaluated angiographically. An abnormal arterial pattern was found in all of the dysplastic limbs. This abnormality was characterized by persistence of an embryonic vascular pattern, absence of one of the normal arteries, and failure of formation of the plantar arch. In each patient there was a(More)
Recent studies of the heads of vertebrates have shown a primitive pattern of segmentation in the mesoderm and neural plate not previously recognized. The role of this pattern in the subsequent distribution of cranial crest and the development of branchial arches and cranial nerves, may resolve century-old arguments about the evolution of vertebrate(More)
We obtain the (Shannon) optimal power and rate allocation strategies for the uplink on single cell systems. For an N user system, we show that successive decoding which is independent of channel state is optimal in the Shannon sense. Using this result, we frame a simple N dimensional convex optimization problem, which is solved to obtain optimum power and(More)