The Implementation of a Hierarchical Hybrid Navigation System for a Mobile Robotic Vehicle

One of the challenges of robotics is to develop a robot control system capable of obtaining intelligent, suitable responses to dynamic environments. The basic requirements for accomplishing this is a robot control architecture and a hardware platform that can adapt the software and hardware to the current state of the environment. This has led researchers to design control architectures composed of distributed, independent and asynchronous behaviours. In line with this research, this thesis details the development of a control system which adopts a hierarchical hybrid navigation architecture designed at Victoria University of Wellington. The implementation of the control system is aimed towards one of Victoria University of Wellington’s fleet of mobile robotic platforms called MARVIN. MARVIN is a differential drive robot and the sensory equipment on the device includes infrared sensors and odometry. The control system has been implemented in C# .NET programming language adopting a Service- Oriented Architecture. This software framework provides several services along with a graphical user interface to configure the control system. Several experiments have been carried out to test the control system and the results indicate that the features of the navigation architecture have been accomplishe

The Implementation of a Hierarchical Hybrid Navigation System for a Mobile Robotic Vehicle

One of the challenges of robotics is to develop a robot control system capable of obtaining intelligent, suitable responses to dynamic environments. The basic requirements for accomplishing this is a robot control architecture and a hardware platform that can adapt the software and hardware to the current state of the environment. This has led researchers to design control architectures composed of distributed, independent and asynchronous behaviours. In line with this research, this thesis details the development of a control system which adopts a hierarchical hybrid navigation architecture designed at Victoria University of Wellington. The implementation of the control system is aimed towards one of Victoria University of Wellington’s fleet of mobile robotic platforms called MARVIN. MARVIN is a differential drive robot and the sensory equipment on the device includes infrared sensors and odometry. The control system has been implemented in C# .NET programming language adopting a Service- Oriented Architecture. This software framework provides several services along with a graphical user interface to configure the control system. Several experiments have been carried out to test the control system and the results indicate that the features of the navigation architecture have been accomplishe

The Implementation of a Hierarchical Hybrid Navigation System for a Mobile Robotic Vehicle

One of the challenges of robotics is to develop a robot control system capable of obtaining intelligent, suitable responses to dynamic environments. The basic requirements for accomplishing this is a robot control architecture and a hardware platform that can adapt the software and hardware to the current state of the environment. This has led researchers to design control architectures composed of distributed, independent and asynchronous behaviours. In line with this research, this thesis details the development of a control system which adopts a hierarchical hybrid navigation architecture designed at Victoria University of Wellington. The implementation of the control system is aimed towards one of Victoria University of Wellington’s fleet of mobile robotic platforms called MARVIN. MARVIN is a differential drive robot and the sensory equipment on the device includes infrared sensors and odometry. The control system has been implemented in C# .NET programming language adopting a Service- Oriented Architecture. This software framework provides several services along with a graphical user interface to configure the control system. Several experiments have been carried out to test the control system and the results indicate that the features of the navigation architecture have been accomplishe

The Implementation of a Hierarchical Hybrid Navigation System for a Mobile Robotic Vehicle

One of the challenges of robotics is to develop a robot control system capable of obtaining intelligent, suitable responses to dynamic environments. The basic requirements for accomplishing this is a robot control architecture and a hardware platform that can adapt the software and hardware to the current state of the environment. This has led researchers to design control architectures composed of distributed, independent and asynchronous behaviours. In line with this research, this thesis details the development of a control system which adopts a hierarchical hybrid navigation architecture designed at Victoria University of Wellington. The implementation of the control system is aimed towards one of Victoria University of Wellington’s fleet of mobile robotic platforms called MARVIN. MARVIN is a differential drive robot and the sensory equipment on the device includes infrared sensors and odometry. The control system has been implemented in C# .NET programming language adopting a Service- Oriented Architecture. This software framework provides several services along with a graphical user interface to configure the control system. Several experiments have been carried out to test the control system and the results indicate that the features of the navigation architecture have been accomplished</p

Opposing post-transcriptional control of InR by FMRP and LIN28 adjusts stem cell based tissue growth

Although the intrinsic mechanisms that control whether stem cells divide symmetrically or asymmetrically underlie tissue growth and homeostasis, they remain poorly defined. We report that the RNA-binding protein fragile X mental retardation protein (FMRP) limits the symmetric division, and resulting expansion, of the stem cell population during adaptive intestinal growth in Drosophila. The elevated insulin sensitivity that FMRP-deficient progenitor cells display contributes to their accelerated expansion, which is suppressed by the depletion of insulin-signaling components. This FMRP activity is mediated solely via a second conserved RNA-binding protein, LIN-28, known to boost insulin signaling in stem cells. Via LIN-28, FMRP controls progenitor cell behavior by post-transcriptionally repressing the level of insulin receptor (InR). This study identifies the stem cell-based mechanism by which FMRP controls tissue adaptation, and it raises the possibility that defective adaptive growth underlies the accelerated growth, gastrointestinal, and other symptoms that affect fragile X syndrome patients

Opposing Post-transcriptional Control of InR by FMRP and LIN-28 Adjusts Stem Cell-Based Tissue Growth

Summary: Although the intrinsic mechanisms that control whether stem cells divide symmetrically or asymmetrically underlie tissue growth and homeostasis, they remain poorly defined. We report that the RNA-binding protein fragile X mental retardation protein (FMRP) limits the symmetric division, and resulting expansion, of the stem cell population during adaptive intestinal growth in Drosophila. The elevated insulin sensitivity that FMRP-deficient progenitor cells display contributes to their accelerated expansion, which is suppressed by the depletion of insulin-signaling components. This FMRP activity is mediated solely via a second conserved RNA-binding protein, LIN-28, known to boost insulin signaling in stem cells. Via LIN-28, FMRP controls progenitor cell behavior by post-transcriptionally repressing the level of insulin receptor (InR). This study identifies the stem cell-based mechanism by which FMRP controls tissue adaptation, and it raises the possibility that defective adaptive growth underlies the accelerated growth, gastrointestinal, and other symptoms that affect fragile X syndrome patients. : Luhur et al. report that FMRP acts via LIN-28 in progenitor cells to dampen the adaptive expansion of intestinal tissue in the fruit fly, raising the possibility that defective LIN28-mediated adaptive growth underlies some of the symptoms that affect fragile X syndrome patients. Keywords: FMRP, fmr1, LIN-28, insulin receptor, IIS, adaptive growth, tissue resizing, intestinal stem cell, insulin sensitivit

Lactate dehydrogenase and glycerol-3-phosphate dehydrogenase cooperatively regulate growth and carbohydrate metabolism during Drosophila melanogaster larval development

The dramatic growth that occurs during Drosophila larval development requires rapid conversion of nutrients into biomass. Many larval tissues respond to these biosynthetic demands by increasing carbohydrate metabolism and lactate dehydrogenase (LDH) activity. The resulting metabolic program is ideally suited for synthesis of macromolecules and mimics the manner by which cancer cells rely on aerobic glycolysis. To explore the potential role of Drosophila LDH in promoting biosynthesis, we examined how Ldh mutations influence larval development. Our studies unexpectedly found that Ldh mutants grow at a normal rate, indicating that LDH is dispensable for larval biomass production. However, subsequent metabolomic analyses suggested that Ldh mutants compensate for the inability to produce lactate by generating excess glycerol-3-phosphate (G3P), the production of which also influences larval redox balance. Consistent with this possibility, larvae lacking both LDH and G3P dehydrogenase (GPDH1) exhibit growth defects, synthetic lethality and decreased glycolytic flux. Considering that human cells also generate G3P upon inhibition of lactate dehydrogenase A (LDHA), our findings hint at a conserved mechanism in which the coordinate regulation of lactate and G3P synthesis imparts metabolic robustness to growing animal tissues