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The metanephros of the birdClayton, Blanche-P. January 1949 (has links)
Certain investigations were undertaken on the kidneys of various birds using that of the domestic fowl, as a type; and, where possible, comparing the results with those reported for other classes of animals.
The vascular system was considered, to establish the statement of Spanner (1924), that the bird kidney possesses a renal portal system. Embryological, histological, and anatomical evidence, were brought forward in favour of this venous arrangement.
The histology was examined with different techniques. In this connection, a comparative examination of fixation fluids was undertaken, as difficulty was experienced in the histological examination of bird kidney tissue.
The histological results indicated some degree of glomerular degeneration and an Increase in proximal tubule development as compared to that of the mammal.
Cytological studies were carried out on mitochondria and the Golgi apparatus.
The mitochondria of the domestic fowl, and the pigeon, showed great concentration in the cells of the proximal tubule.
The Golgi apparatus was investigated in the fowl; and showed a development in the cells of the proximal segment of the nephron, in excess of that in the mammal.
The conclusion deduced from both these cytological studies, indicated an increase in activity of the proximal segment in the bird, over that of the mammal.
A histochemical test using alkaline phosphatase, was performed, to decide whether the reported glomerular degeneration in the bird is such that glucose elimination is reduced or absent. Alkaline phosphatase is an enzyme stated to assist in the reabsorption of glucose eliminated by glomerular filtration. The results were compared with those of the classes possessing good glomerular development. It was noted that the avian kidney shows considerable evidence of alkaline phosphatase activity.
Two conclusions are reached:
(1) That the bird kidney shows definite evidence of tubular activity.
(2) That in spite of apparent signs of degeneration, the glomerulus in the avian kidney functions comparably to that of the mammal. / Science, Faculty of / Zoology, Department of / Graduate
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Development of the pulmonary surfactant system in non-mammalian amniotesJohnston, Sonya D. (Sonya Denise) January 2001 (has links) (PDF)
"March 2001". Bibliography: leaves 193-238. Relates changes in the development of the pulmonary surfactant system in response to birth strategy, lung morphology and phylogeny in order to determine the extent of conservation in this process, by quantifying the total of phsospholipid, disaturated phospholipid and cholesterol in the lung washings of embryonic and hatchling chickens, oviparous bearded dragons and viviparous sleepy lizards, snapping turtles and green sea turtles throughout the final stages of incubation and gestation. Finds that the pattern of development of pulmonary surfactant lipids is consistent with that of mammals.
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Development of the pulmonary surfactant system in non-mammalian amniotes / Sonya D. Johnston.Johnston, Sonya D. (Sonya Denise) January 2001 (has links)
"March 2001". / Bibliography: leaves 193-238. / vii, 238 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Relates changes in the development of the pulmonary surfactant system in response to birth strategy, lung morphology and phylogeny in order to determine the extent of conservation in this process, by quantifying the total of phsospholipid, disaturated phospholipid and cholesterol in the lung washings of embryonic and hatchling chickens, oviparous bearded dragons and viviparous sleepy lizards, snapping turtles and green sea turtles throughout the final stages of incubation and gestation. Finds that the pattern of development of pulmonary surfactant lipids is consistent with that of mammals. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 2001
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Development of the pulmonary surfactant system in non-mammalian amniotes / Sonya D. Johnston.Johnston, Sonya D. (Sonya Denise) January 2001 (has links)
"March 2001". / Bibliography: leaves 193-238. / vii, 238 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Relates changes in the development of the pulmonary surfactant system in response to birth strategy, lung morphology and phylogeny in order to determine the extent of conservation in this process, by quantifying the total of phsospholipid, disaturated phospholipid and cholesterol in the lung washings of embryonic and hatchling chickens, oviparous bearded dragons and viviparous sleepy lizards, snapping turtles and green sea turtles throughout the final stages of incubation and gestation. Finds that the pattern of development of pulmonary surfactant lipids is consistent with that of mammals. / Thesis (Ph.D.)--University of Adelaide, Dept. of Physiology, 2001
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The evolution of avian hindlimb conformation and locomotor functionAllen, Vivian Richard January 2011 (has links)
No description available.
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A comparative study of the energetics of avian reproduction / by James Todd Pearson.Pearson, James Todd January 1994 (has links)
Bibliography: p.222-233. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1995?
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Epigenetic modification of the hypothalamic-pituitary-adrenal axis during early life of the house sparrow (Passer domesticus)Siller, Stefanie January 2022 (has links)
The early environment impacts many aspects of an individual’s developing phenotype. In particular, early environmental conditions are important for shaping the hypothalamic-pituitary-adrenal (HPA) axis, which coordinates an individual’s stress response. These developmental changes are likely mediated by epigenetic modifications, functional changes to the genome that can alter gene expression in response to environmental variation, resulting in significant phenotypic differences (Kundakovic and Champagne 2015; Richards 2006). Determining how early life variation alters epigenetic modifications (such as DNA methylation) of genes throughout the HPA axis, and how these marks change over time, in wild organisms is important for understanding their potential long-term fitness consequences. Here, I examine DNA methylation modifications in the HPA axis in relation to early environmental variation in free-living house sparrows (Passer domesticus).
In Chapter 1, I show a relationship between natural variation in the early environment and DNA methylation marks of numerous genes related to HPA axis function, which in turn predict growth trajectories. In Chapter 2, I show that early life stress in particular impacts DNA methylation in genes critical to HPA axis function, but does so differently depending on the life history stage in which stress is encountered. Finally, in Chapter 3, I find that these early life marks have long-term effects past the developmental period, predicting longevity as well as lifetime reproductive output in a sex-specific manner. Overall, my dissertation adds to a growing understanding of the dynamic role of epigenetic modifications in mediating phenotypic responses to the early life environment in wild birds, and demonstrates the potential long-term fitness outcomes of these changes.
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The Role of Thyroid Hormone across Avian Development Spectrum: Investigations on Systemic Development, Metabolism and Ontogeny of EndothermySirsat, Tushar Saoji 08 1900 (has links)
Achievement of endothernic capacity is vital for independence from ambient temperature changes, sustained activity, optimal biochemical reactions and optimization of parental care. During early avian development, the core tenets of transition from ectothermy to endothermy are development of metabolic capacity (oxygen consumption, mitochondrial bioenergetics), enhanced cardiovascular function (heart rate and cardiac output), pulmonary ventilation and thermogenic capacity. Thyroid hormones, particularly T3, are key metabolic regulators of basal metabolism, thermogenesis, pulmonary ventilation and mitochondrial respiration. Thyroid hormone fluctuation patterns during both precocial and altricial avian endothermic transition suggest a prominent role in maturation of endothermy, cardiovascular, respiratory and skeletal muscle physiology. This body of work explores effects of T3 manipulations in two avian species: the precocial Pekin duck and the altricial Red-winged Blackbird. Increased plasma T3 during late incubation resulted in increased cardiac mass, elevated resting and intrinsic heart rate, intrinsic mean arterial pressure, increased cholinergic tone and blunted alpha-adrenergic tone in the precocial Pekin duck. In both Pekin duck and Red-winged blackbird, plasma T3 levels correlated with changes in the trajectory of endothermic ontogeny, systemic oxygen consumption, thermogenesis, maturation of pulmonary ventilatory function, altered growth and effects on skeletal and cardiac mitochondrial bioenergetics. These observations support the role of thyroid hormones as metabolic and developmental regulators at the time of attainment of endothermy during the perinatal period in precocial and altricial avian species. Insights into the role of thyroid hormone as a metabolic and development regulator at the time of avian endothermic attainment provide a more thorough understanding of metabolic and physical transitions a hatchling bird must undergo to reach the adult endothermic phenotype. Such insights also deepen understanding of the complex role thyroid hormones play in homeostasis and offer implications about the evolutionary history of endothermic capacity.
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