Cross-Entropy Methods in Complex Biological Systems. The Cross-Entropy method provides a powerful new way to find superior solutions to complicated optimisation problems in biology, ranging from better design and implementation of medical treatments to an increased understanding of complex ecosystems.
Emergence of robust, stable structures via computation within natural networks. An ever-increasing challenge for modern society is the sheer complexity of vast infrastructures. Unexpected, and sometimes catastrophic, behaviour often emerges from interactions between elements of large systems. As a result, highly complex systems such as the Internet, international finance markets, and power grids are highly susceptible to costly problems such as cascading failures, inefficiency, and critical sens ....Emergence of robust, stable structures via computation within natural networks. An ever-increasing challenge for modern society is the sheer complexity of vast infrastructures. Unexpected, and sometimes catastrophic, behaviour often emerges from interactions between elements of large systems. As a result, highly complex systems such as the Internet, international finance markets, and power grids are highly susceptible to costly problems such as cascading failures, inefficiency, and critical sensitivity. High-tech industries, such as biotechnology and information networking, also face problems in coordinating swarms of interacting agents. This project will contribute to solving such problems by identifying and adapting solutions from nature.Read moreRead less
Dual phase evolution in networks. A grand challenge for modern society is the sheer complexity of vast networks arising from organizations and infrastructures. Unexpected, sometimes catastrophic, behaviour often emerges from interactions within such systems. As a result, the Internet, financial markets, power grids and other vital infrastructures are susceptible to costly problems such as cascading failures, inefficiency, and unpredictability. High-tech industries, such as biotechnology and info ....Dual phase evolution in networks. A grand challenge for modern society is the sheer complexity of vast networks arising from organizations and infrastructures. Unexpected, sometimes catastrophic, behaviour often emerges from interactions within such systems. As a result, the Internet, financial markets, power grids and other vital infrastructures are susceptible to costly problems such as cascading failures, inefficiency, and unpredictability. High-tech industries, such as biotechnology and information networking, face problems in coordinating networks of interacting agents. This project will expand the horizon of complex systems by deriving the design principles underpinning stable and resilient network structures and validate these principles on real world networks.Read moreRead less
Assembly of neural circuits during development. This program aims to understand how nerve cells wire up accurately during development. Specifically, the program will determine how neuronal connections are established in the retina to produce a sensory structure essential for vision. The program will also generate innovative tools for watching in live animals, the making and breaking of connections during normal and abnormal development. Discoveries will not only significantly increase our knowle ....Assembly of neural circuits during development. This program aims to understand how nerve cells wire up accurately during development. Specifically, the program will determine how neuronal connections are established in the retina to produce a sensory structure essential for vision. The program will also generate innovative tools for watching in live animals, the making and breaking of connections during normal and abnormal development. Discoveries will not only significantly increase our knowledge base of how the nervous system develops or degenerates, but the results will provide crucial information for future studies based on genetic approaches, drug therapies and bioengineering technology to repair the injured nervous system.Read moreRead less
Structure and function of heterodimeric amino acid transporters. Recently a new family of amino acid transporters has been identified, the members of which are involved in the delivery of amino acids between cells and tissues. All members display a rather unusual structure in that they require two subunits to be functional. The main aim of this study is to investigate the interaction between large and small subunits. The study will give insight how membrane proteins form complexes in the membran ....Structure and function of heterodimeric amino acid transporters. Recently a new family of amino acid transporters has been identified, the members of which are involved in the delivery of amino acids between cells and tissues. All members display a rather unusual structure in that they require two subunits to be functional. The main aim of this study is to investigate the interaction between large and small subunits. The study will give insight how membrane proteins form complexes in the membrane and how these interactions affect the function of a complex membrane protein.Read moreRead less
Improving the accuracy of phylogenetic reconstruction by improving models of sequence divergence. Phylogenies describe the relationships among species and provide the essential framework for understanding evolutionary processes. They are an essential tool in the identification of functionally important regions in DNA sequences. An important aspect of identifying phylogenies is measuring how DNA sequences change in time. The proposed research will develop sophisticated, practical models of sequen ....Improving the accuracy of phylogenetic reconstruction by improving models of sequence divergence. Phylogenies describe the relationships among species and provide the essential framework for understanding evolutionary processes. They are an essential tool in the identification of functionally important regions in DNA sequences. An important aspect of identifying phylogenies is measuring how DNA sequences change in time. The proposed research will develop sophisticated, practical models of sequence divergence and make them freely available in open source software. The software and models will positively impact on studies seeking to understand Australian biological diversity. The proposed resolution of the eutherian mammal orders will further significantly impact on utilisation of rodents as a model organism for human biology.Read moreRead less
Assessing the physiological roles of ubiquitination in regulating neuronal ion channels, receptors and transporters. Significant alterations in the activity neuronal transporters and receptors occur during tissue injury and regeneration as well as in many neurodegenerative disease states. Modulation of the pathways that control these transporters is an emerging therapeutic target, however, the molecular basis of these control mechanisms remain poorly understood. The outcome of this project will ....Assessing the physiological roles of ubiquitination in regulating neuronal ion channels, receptors and transporters. Significant alterations in the activity neuronal transporters and receptors occur during tissue injury and regeneration as well as in many neurodegenerative disease states. Modulation of the pathways that control these transporters is an emerging therapeutic target, however, the molecular basis of these control mechanisms remain poorly understood. The outcome of this project will be a thorough characterisation of a novel regulatory paradigm in neurons that is likely to be crucial for neuronal development and regeneration, and will potentially provide novel therapeutic targets for various neuronal diseases.Read moreRead less
G-protein coupled receptor-mediated calcium signalling in parasympathetic neurons. External chemical stimuli act on specific cell-surface receptors of neurons resulting in an increase in the intracellular calcium ion concentration which acts as a second messenger to alter neuronal excitability. There are, however, many receptors acting through a number of closely related proteins involving complex intracellular signalling pathways which remain poorly understood. This project uses molecular, elec ....G-protein coupled receptor-mediated calcium signalling in parasympathetic neurons. External chemical stimuli act on specific cell-surface receptors of neurons resulting in an increase in the intracellular calcium ion concentration which acts as a second messenger to alter neuronal excitability. There are, however, many receptors acting through a number of closely related proteins involving complex intracellular signalling pathways which remain poorly understood. This project uses molecular, electrical and fluorescence techniques to elucidate the molecular basis for these interactions by identifying the roles individual proteins play in integrating diverse extracellular stimuli and neuronal excitablility in the peripheral nervous system.Read moreRead less
Functional ubiquitination of neuronal voltage-gated sodium channels. Alterations in the electrical properties of excitable cells occur during tissue injury and regeneration as well as many disease states. Preventing or controlling these changes is a key strategic therapeutic aim. It is, however, only through a comprehensive understanding of the molecular mechanisms that regulate cellular excitability that we can identify these therapeutic targets. The major outcome of this project will be a thor ....Functional ubiquitination of neuronal voltage-gated sodium channels. Alterations in the electrical properties of excitable cells occur during tissue injury and regeneration as well as many disease states. Preventing or controlling these changes is a key strategic therapeutic aim. It is, however, only through a comprehensive understanding of the molecular mechanisms that regulate cellular excitability that we can identify these therapeutic targets. The major outcome of this project will be a thorough characterisation of a novel pathway that is potentially crucial in the development, homeostasis and regeneration of the nervous system. Disruption of normal function of this system may underlie the hyperexcitability observed in mannu neurodegenerative conditions.Read moreRead less
Glycerotoxin, a unique tool to investigate the dynamic interactions between N-type Ca2+ channels and the exo-endocytic machinery. Communication between neurons relies on exocytosis, a process in which synaptic vesicles containing a neurotransmitter release their content in the extracellular synaptic cleft. We have recently discovered a unique neurotoxin called glycerotoxin (GLTx), which selectively activates Ca2+ channels (Cav2.2), linked with the exocytic machinery in the Central Nervous System ....Glycerotoxin, a unique tool to investigate the dynamic interactions between N-type Ca2+ channels and the exo-endocytic machinery. Communication between neurons relies on exocytosis, a process in which synaptic vesicles containing a neurotransmitter release their content in the extracellular synaptic cleft. We have recently discovered a unique neurotoxin called glycerotoxin (GLTx), which selectively activates Ca2+ channels (Cav2.2), linked with the exocytic machinery in the Central Nervous System. GLTx provide a new tool to further dissect the role of Cav2.2 in controlling neurotransmitter release. GLTx also greatly facilitates synaptic vesicle recycling, suggesting an unexpected link between Cav2.2 activation and the compensatory endocytic machinery. Our goal is to investigate functional coupling between Cav2.2 and the exo- and endocytic machineries using GLTx.Read moreRead less