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Biomedical subjects

H F Landreth

Publications and source records attributed to H F Landreth.

5 recordsLinked to original sources

Blood respiratory properties of Bison bison.

The respiratory properties and basic hematology of blood from seven adult bison and one calf were determined. Average oxygen-carrying capacity was 22.2 ml/100 ml blood from adults and 17.0 in calf blood; hemoglobin averaged 17.1 g/100 ml in adults and 13.6 in the calf. Half saturation of the blood occurred at 32mm Hg Po2 at pH 7.40 and 37 degrees C. The average Bohr effect was -0.40. Erythrocytes numbered 8.6 X 10(6)/mm3 and were 52 micron 3 in mean volume. Adult and calf cells differed in mean cell hemoglobin, adults 19.9 pg/cell vs 15.9 in the calf, and this difference evidently caused differences in Haldane effect, standard bicarbonate, and buffering capacity. Bison are capable of prolonged running. Two features of the blood that promote this capacity are its comparatively great oxygen-carrying capacity and low oxygen affinity.

Age Factors↗

Newts: sun-compass orientation.

Rough-skinned newts, captured from breeding ponds, oriented on courses that would have intersected the familiar shorelines at right angles, when released in a circular arena on land under the sun or moon. Pondward migrants oriented similarly. Reorientation failed under complete cloud cover and after 7 days of darkness in an environmental chamber, but persisted in newts whose eyes were excised and in those displaced more than 27 kilometers in darkness. Both normal and blind animals compensated for displacement in sunshine. Preliminary evidence suggests that alternative light receptors in blinded animals may be associated with the optic tectum. No evidence of olfactory guidance was observed.

Adaptation, Biological↗