Structural and neural determinants of stress and strain in human muscle. This project aims to further our understanding of the biomechanical stress and strains experienced by contracting human muscles. Using innovative imaging techniques such as microendoscopy and supersonic shear imaging, we expect to generate new significant evidence on the structural and neural factors that lead to areas of high stress in human muscles. Outcomes of this project include not only a new understanding of muscle d ....Structural and neural determinants of stress and strain in human muscle. This project aims to further our understanding of the biomechanical stress and strains experienced by contracting human muscles. Using innovative imaging techniques such as microendoscopy and supersonic shear imaging, we expect to generate new significant evidence on the structural and neural factors that lead to areas of high stress in human muscles. Outcomes of this project include not only a new understanding of muscle design on multi-scale level, but also of muscle function and adaptation. This should provide significant benefits in better predicting muscle injury and prescribing safe exercise, knowledge that would benefit biomechanical engineers and sport and exercise professionals.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
Responses of reptiles to fluctuating thermal environments: behaviour or biochemistry? I propose a conceptual shift in the way thermal physiology of reptiles is interpreted, questioning the predominant role of behaviour in reptilian thermoregulation. I will test the hypothesis that changes in cellular biochemistry are an important mechanism by which reptiles respond to environmental fluctuations. I will determine the relationship between metabolic enzyme activity and performance functions, and ....Responses of reptiles to fluctuating thermal environments: behaviour or biochemistry? I propose a conceptual shift in the way thermal physiology of reptiles is interpreted, questioning the predominant role of behaviour in reptilian thermoregulation. I will test the hypothesis that changes in cellular biochemistry are an important mechanism by which reptiles respond to environmental fluctuations. I will determine the relationship between metabolic enzyme activity and performance functions, and the results may call for a re-assessment of current concepts such as the notion that reptiles must achieve "preferred" body temperatures to maintain performance.Read moreRead less
Cell death by self-eating: Autophagy-dependent tissue removal. This project aims to study the mechanisms and regulation of autophagy-dependent cell death. Cell death maintains cell and tissue homeostasis. Although most cell death is mediated by apoptosis, other modes of cell deletion have emerged recently. One form of cell death involves autophagy, the catabolic process of cellular self-digestion through lysosomal enzymes. As autophagy is a default mechanism of cell survival under stress, the id ....Cell death by self-eating: Autophagy-dependent tissue removal. This project aims to study the mechanisms and regulation of autophagy-dependent cell death. Cell death maintains cell and tissue homeostasis. Although most cell death is mediated by apoptosis, other modes of cell deletion have emerged recently. One form of cell death involves autophagy, the catabolic process of cellular self-digestion through lysosomal enzymes. As autophagy is a default mechanism of cell survival under stress, the idea of autophagy-dependent cell death has been controversial. This proposal aims to resolve this question and provide highly topical knowledge of broad biological significance.Read moreRead less
Regulation of salt gland activity in the estuarine crocodile: phenotypic plasticity and control mechanisms. The estuarine crocodile excretes excess sodium and chloride ions through salt glands located on the tongue, enabling the crocodile to live in seawater. This study will investigate the regulation of salt gland secretory capacity and activity, by examining both the phenotypic plasticity of the gland to changes in environmental salinity and diet, and by determining the neural/humoral mech ....Regulation of salt gland activity in the estuarine crocodile: phenotypic plasticity and control mechanisms. The estuarine crocodile excretes excess sodium and chloride ions through salt glands located on the tongue, enabling the crocodile to live in seawater. This study will investigate the regulation of salt gland secretory capacity and activity, by examining both the phenotypic plasticity of the gland to changes in environmental salinity and diet, and by determining the neural/humoral mechanisms controlling secretory rate. In vivo measurements of blood flow and salt gland secretory rate, together with perfused gland preparations will reveal extrinsic and intrinsic factors controlling salt gland activity and the degree of coupling between blood flow and secretory rate.Read moreRead less
Of birds and bees: membrane lipids and the determination of maximum lifespan. The underlying mechanisms that determine why different animals have different maximum lifespans are unknown. Why do queen bees live for years but the genetically-identical workers bees live for only weeks? Similarly, to understand why birds live much longer than similar-sized mammals will give immense insight into the processes that cause ageing. Understanding the aging process in animals will have significant implicat ....Of birds and bees: membrane lipids and the determination of maximum lifespan. The underlying mechanisms that determine why different animals have different maximum lifespans are unknown. Why do queen bees live for years but the genetically-identical workers bees live for only weeks? Similarly, to understand why birds live much longer than similar-sized mammals will give immense insight into the processes that cause ageing. Understanding the aging process in animals will have significant implications for human health as the biggest risk factor for most diseases is age. Such understanding will help to cope with the worldwide problems of an aging population.Read moreRead less
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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Specialized glial cells within the hippocampus of the brain regulate important morphological events in embryonic development. Memories of past experiences, and our ability to learn new information, is processed in a region of the brain called the hippocampus. In order for this to occur, the cells that make up the hippocampus must form correctly during embryonic development. This proposal investigates the cellular and molecular mechanisms regulating hippocampal formation. The national benefit of ....Specialized glial cells within the hippocampus of the brain regulate important morphological events in embryonic development. Memories of past experiences, and our ability to learn new information, is processed in a region of the brain called the hippocampus. In order for this to occur, the cells that make up the hippocampus must form correctly during embryonic development. This proposal investigates the cellular and molecular mechanisms regulating hippocampal formation. The national benefit of this work is to provide basic knowledge about the processes that underlie correct brain formation and function, and to understand what processes are disrupted when the brain fails to function correctly. Such disruptions lead to mental retardation and learning difficulties, and in the aged, an inability to form and store new memories, as occurs in dementia.Read moreRead less
Unified framework of intestinal motility. The project aims to establish how a few fundamental mechanisms determine the large repertoire of intestinal motor patterns responsible for moving nutrients along the digestive tract. The project will combine experimental and theoretical data, with biomechanical and electrophysiological models to create a new understanding of this essential function of the body.
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