Brain temperature regulation in mammals: mechanisms and consequences. Mammals detect increases in body temperature predominantly in the brain. Counterintuitively many mammals selectively cool the brain during heat stress, which appears to defeat the mechanism for inducing cooling responses. We intend to investigate this apparent anomaly which we believe is concerned with optimizing water use in hot conditions. We will further investigate the source of water for evaporative cooling by panting and ....Brain temperature regulation in mammals: mechanisms and consequences. Mammals detect increases in body temperature predominantly in the brain. Counterintuitively many mammals selectively cool the brain during heat stress, which appears to defeat the mechanism for inducing cooling responses. We intend to investigate this apparent anomaly which we believe is concerned with optimizing water use in hot conditions. We will further investigate the source of water for evaporative cooling by panting and discover if there has been convergent evolution in thermoregulatory strategies in the eutherian and marsupial lineages. The data we collect will be used to support a new model for thermoregulation in mammals.
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The comparative physiology of oxygen delivery to the kidney. The kidney is in danger of hyperoxia because the kidney receives so much blood relative to its mass. It is proposed that shunting oxygen between arteries and veins substantially mitigates the risk of hyperoxia, but under certain circumstances shunting substantially increases the risk of kidney hypoxia. Using a combination of synchrotron and histological imaging, This project will carefully define the three-dimensional vasculature of th ....The comparative physiology of oxygen delivery to the kidney. The kidney is in danger of hyperoxia because the kidney receives so much blood relative to its mass. It is proposed that shunting oxygen between arteries and veins substantially mitigates the risk of hyperoxia, but under certain circumstances shunting substantially increases the risk of kidney hypoxia. Using a combination of synchrotron and histological imaging, This project will carefully define the three-dimensional vasculature of the renal cortex in several different species and interpret its functional significance using computational modeling. The outcome of this project will be a new understanding in the comparative physiology of oxygen transport and shunting in the kidney.Read moreRead less
Calls and constraints: do male frogs signal direct benefits? There is international concern over recent declines and disappearances of many species of amphibians. Australia is a hotspot for declines, but causes of declines remain enigmatic. Approximately one quarter of Australia's 230 amphibian species breed in terrestrial situations, but processes such as salinity, wetland and urban developments and climate change are altering the hydrology of our landscape, and preventing the flood events nece ....Calls and constraints: do male frogs signal direct benefits? There is international concern over recent declines and disappearances of many species of amphibians. Australia is a hotspot for declines, but causes of declines remain enigmatic. Approximately one quarter of Australia's 230 amphibian species breed in terrestrial situations, but processes such as salinity, wetland and urban developments and climate change are altering the hydrology of our landscape, and preventing the flood events necessary for the completion of the lifecycle of many species. This research has important conservation implications because it examines the effects of variable moisture regimes on the physiology and reproductive behaviours of terrestrial breeding frogs.Read moreRead less
Scaling of structure, function and energetics of the vertebrate cardiovascular system. The hearts of mammals, reptiles and fish do different amounts of work, depending on the animal’s metabolic rate and body size. This project attempts to understand why hearts are the size and thickness that they are, and whether this results in minimising the work necessary to satisfy the requirements of the animal.
The entrainment of circadian rhythms in marsupial mammals: behavioural and sub-cellular investigation of non-rod, non-cone ocular photoreceptors. Our investigation will provide a contribution to understanding the role that photoreceptors play in the mechanisms that control circadian rhythms and will ultimately lead to a better understanding of the basic physiology of sleep and circadian cycles, their contribution to learning and memory and their impact on waking performance. Targeted drug develo ....The entrainment of circadian rhythms in marsupial mammals: behavioural and sub-cellular investigation of non-rod, non-cone ocular photoreceptors. Our investigation will provide a contribution to understanding the role that photoreceptors play in the mechanisms that control circadian rhythms and will ultimately lead to a better understanding of the basic physiology of sleep and circadian cycles, their contribution to learning and memory and their impact on waking performance. Targeted drug development and the design of lighting systems effective in regulating circadian rhythms will improve the quality of life and competitiveness of the many citizens who endure abnormal sleep/wakefulness schedules.Read moreRead less
Sugar and water handling by honeyeaters and sunbirds. Honeyeaters are the major vertebrate pollinators in Australia, playing a vital role in maintenance of healthy ecosystems. These birds are faced with extreme physiological challenges due to their diet, ingesting 2-5 times their body mass in nectar to obtain their daily sugar requirement. Nectarivores are, consequently, masters at processing and assimilating sugars and water; comparative physiology of these charismatic birds will provide deep u ....Sugar and water handling by honeyeaters and sunbirds. Honeyeaters are the major vertebrate pollinators in Australia, playing a vital role in maintenance of healthy ecosystems. These birds are faced with extreme physiological challenges due to their diet, ingesting 2-5 times their body mass in nectar to obtain their daily sugar requirement. Nectarivores are, consequently, masters at processing and assimilating sugars and water; comparative physiology of these charismatic birds will provide deep understanding of sugar and water handling mechanisms. Understanding gut and renal physiology and morphology contributes to the broad base of knowledge required to address pathological and clinical conditions in man, and will enhance our ability to predict effects of environmental change on these birds.Read moreRead less
Significance and mechanisms of evaporative water loss control by endotherms. This project plans to examine the novel hypothesis that mammals and birds can control and minimise their evaporative water loss in dry environments. Water balance is fundamental for the survival of mammals and birds. As a large component of total water loss, evaporative water loss is particularly critical for species in arid habitats and areas undergoing desertification and other habitat modifications. Control of water ....Significance and mechanisms of evaporative water loss control by endotherms. This project plans to examine the novel hypothesis that mammals and birds can control and minimise their evaporative water loss in dry environments. Water balance is fundamental for the survival of mammals and birds. As a large component of total water loss, evaporative water loss is particularly critical for species in arid habitats and areas undergoing desertification and other habitat modifications. Control of water loss is a previously unappreciated ability in mammals and birds. Determining the mechanistic basis for evaporative homeostasis would fundamentally change our knowledge of animal function, and may help us to predict and understand the effects of environmental change on survival and distribution limits for Australian fauna.Read moreRead less