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Biomedical subjects

D Charlesworth

Publications and source records attributed to D Charlesworth.

5 recordsLinked to original sources
PubMed1979

The evolutionary genetics of sexual systems in flowering plants.

Population genetic studies of the evolution of breeding systems in flowering plants are reviewed. The selective advantage of a gene's increasing the selfing rate is stressed. In the evolution of outbreeding mechanisms, some strong disadvantage to selfing must therefore be acting; it is suggested that this disadvantage is inbreeding depression. Populations with no absolute barrier to selfing, and with intermediate levels of self-fertilization, appear to be the most likely starting state for the evolution of outbreeding mechanisms. There is some evidence for inbreeding depression in such populations. The evolution of distyly and dioecy are considered in some detail. An explanation for the existence of supergenes controlling these systems is proposed. The breakdown of distyly and tristyly are also considered. The evolution of recombination rates in selfing and outcrossing species is examined briefly.

Biological Evolution↗
PubMed1979

A study of arterial prostheses by scanning electron microscopy.

Scanning electron micrographs were taken of ten different vascular prostheses. The micrographs showed that some prostheses were damaged and some had traces of chemicals on their surface. The application of standard vascular clamps damaged most grafts and some showed remarkable changes on resterilization.

Arteries↗
PubMed1979

The early results of reconstruction of the femoral artery with a Gore-Tex prosthesis.

An analysis is presented of the results of forty-one reconstructions of the superficial femoral artery using a Gore-Tex prosthesis. There were four complications and the results, when the boundary conditions were good, were comparable to those obtained from reconstruction with autogenous vein. Most failures occurred in patients in whom the branches of the popliteal artery were obliterated. We concluded that a Gore-Tex prosthesis is a reasonable alternative when autogenous vein is unavailable, but it is overly optimistic to expect any prosthesis to work in circumstances where a vein is unlikely to work.

Aged↗
PubMed1979

Changes in the coagulation of blood during resection of the abdominal aorta.

In 33 patients, a significant fall in the fibrinogen level occurred during an operation to replace the abdominal aorta by a bifurcated prosthesis. There was a similar, but less marked, fall in the fibrinogen level of ten patients having a femoropopliteal vein bypass. A concomitant drop in the plasma plasminogen value was also found. Results of specific laboratory tests for intravascular clotting and activation of fibrinolysis were negative. This suggests that fibrinogen may be removed by physical means. The fall in fibrinogen was so low in some patients that the routine administration of a conventional dosage of heparin could be dangerous.

Adult↗