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Biomedical subjects

M Finnegan

Publications and source records attributed to M Finnegan.

24 records · Page 2Linked to original sources

Epiphysiolysis, a possible cause of limb deformities in lambs.

The process of enchondral growth of long bones of four three month old lambs raised in total confinement and showing bowed forelimbs was investigated. The results, based on radiologic, histologic, and fluorescence microscopic examinations were compared to findings made in four age-matched controls. The principle finding was that the transition from cartilage cores to primary trabeculae at the growth plate was deficient. In two instances a slipping of the distal radial epiphysis and in one instance a slipping of the metacarpal epiphysis was found. In the others, evidence of a healed slipping was present. It is postulated that the slip is responsible for the deformity.

Animals↗

Empirical comparison of distance equations using discrete traits.

The use of the Grewal-Smith statistic in measuring biological distance among skeletal population samples has been questioned since it was first applied to human populations. Recently, in an attempt to stabilize the variance of the Grewal-Smith statistic for use with non-metric analysis, Sjøhivold ('73) and Green and Suchey ('76) have introduced corrections and alternative transformations which may enhance the meaning of biological distance among population samples. Their recommendations improve the statistics for specific variable ranges; i.e., small sample size and low trait frequencies. Thirteen equations representing Grewal-Smith, Freeman-Tukey, Anscombe, and Bartlett transformations and/or corrections, were compared using rank order correlation statistics on actual biological distances generated by real population data as presented in existing literature. Results from testing these actual distance models show little variation between equations based on the populational data sets used. Based on these findings, the distance model resulting from the Grewal-Smith statistic is not inferior to the more sophisticated models, although the latter may be superior allowing specific improvements for small sample size and/or low trait frequencies.

Bone and Bones↗

Non-metric variation of the infracranial skeleton.

196 skeletons of known age, sex and rac from the Terry Collection were studied in order to document 30 non-metric infracranial traits. Each trait had the ability to be expressed bilaterally, although significant side dimorphism was not observed. Sex differences were statistically significant for some of the traits within a racial group, but these differences were not as pronounced as the differences generated by non-metric cranial traits in the same populations, and were not effective in all racial groups. In general, these infracranial traits show some age dependency when correlation statistics are used, but this dependency is lost when the more robust chi 2 statistic is used. These data suggest that infracranial non-metric traits may be superior to cranial non-metric traits for population comparisons. Infracranial traits may be more durable than cranial traits having regard to the nature of most archaeological material.

Adult↗

A compact and noise free electrohydraulic total artificial heart.

The ABIOMED total artificial heart (TAH) is designed for long-term tether-free use in patients with end-stage heart disease. Blood pumping is achieved through hydraulic fluid motion across flexing diaphragms. The hydraulic power is derived from a miniature centrifugal pump (50% efficiency). Flow directional change needed for alternate left and right filling and ejection is achieved with a rotary valve. With no mechanical contact with the flexing membrane, the wedge angle between the two pumps sandwiching the energy convertor can be easily optimized for anatomic fit. The blood pumps (80 ml strokes) are fitted with trileaflet polyetherurethane valves (24 mm). The TAH is implanted using twist-lock stepless quick connectors to the inflow cuffs and outflow grafts. Left-right flow balance is achieved with an atrial hydraulic shunt placed between the left cuff and inflow valve. Animal studies show that the TAH fits very well in Long Horn calves weighing 90 to 100 kg and can provide cardiac output in excess of 10 L/min. A cadaver (85 kg) study showed the TAH fits within the pericardial region.

Adult↗