275 research outputs found

    Collaborative Research: Matching Levels of Detail in Descriptions and Depictions of Geographic Space

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    This collaborative research project focuses on issues related to wayfinding, and is at the interface of geographic information science and human cognition. The research addresses the questions of the relationship between verbal and pictorial representations of geographic information, and how both representation modes can be successfully integrated in systems relating geographic information to users. To address this question, a theory of content and level of geographic detail is constructed that is independent of specific mode. The research is founded upon computational and cognitive theories of geographic information. The main idea is that theories of information granularity can be imposed on a \u27canonical model\u27 of dual mode information, enabling inter-modal comparisons and transformations to be made between levels of detail and information content. The level of detail that should be presented in each of the verbal and pictorial modes, and relationships between levels of detail in each mode, are important areas of investigation. The theory of information granularity should accord with human cognition, and a major part of the work will be the testing of the theory by a graded set of experiments with human subjects. The research will be evaluated through the construction of a demonstrator mobile \u27wayfinding assistant\u27 that will operate using both verbal and pictorial modes. This project is motivated by the task of wayfinding in an unknown city, using a portable, mobile, digital wayfinding assistant, with two interaction modes, verbal and pictorial, and some locational and directional capabilities. With increasing use of multimedia, this research will help to formulate guidelines for effective presentation of pictoral and verbal spatial information. The research addresses fundamental questions such as: What should be the balance between modes of information supplied to the user? Should the information to be represented in each mode be complementary or supplementary? If it is necessary to \u27switch off\u27 a mode, how can this be done seamlessly, with the same level of detail presented? The ability to change flexibly between modalities may be especially appropriate for individuals with sensory impairments, as well as those whose tasks require both modes operating simultaneously, or those who need to switch seamlessly between modes (e.g. a driver of a vehicle who must switch from a visual display to audio cues because of the need to concentrate full visual attention on a traffic situation)

    Mechanoactivation of Wnt/β-catenin pathways in health and disease

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    Mechanical forces play an important role in regulating tissue development and homeostasis in multiple cell types including bone, joint, epithelial and vascular cells, and are also implicated in the development of diseases, e.g. osteoporosis, cardiovascular disease and osteoarthritis. Defining the mechanisms by which cells sense and respond to mechanical forces therefore has important implications for our understanding of tissue function in health and disease and may lead to the identification of targets for therapeutic intervention. Mechanoactivation of the Wnt signalling pathway was first identified in osteoblasts with a key role for β-catenin demonstrated in loading-induced osteogenesis. Since then, mechanoregulation of the Wnt pathway has also been observed in stem cells, epithelium, chondrocytes and vascular and lymphatic endothelium. Wnt can signal through both canonical and non-canonical pathways, and evidence suggests that both can mediate responses to mechanical strain, stretch and shear stress. This review will discuss our current understanding of the activation of the Wnt pathway in response to mechanical forces

    Monitoring Dynamic Spatial Fields Using Responsive Geosensor Networks

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    Many environmental phenomena (e.g., changes in global levels of atmospheric carbon dioxide) can be modeled as variations of attributes over regions of space and time, called dynamic spatial fields. The goal of this project is to provide efficient ways for sensor networks to monitor such fields, and to report significant changes in them. The focus is on qualitative changes, such as splitting of areas or emergence of holes in a region of study. The approach is to develop qualitative and topological methods to deal with changes. Qualitative properties form a small, discrete space, whereas quantitative values form a large, continuous space, and this enables efficiencies to be gained over traditional quantitative methods. The combinatorial map model of the spatial embedding of the sensor network is rich enough so that for each sensor, its position, and the distances and bearings of neighboring sensors, are easily computed. The sensors are responsive to changes to the spatial field, so that sensors are activated in the vicinity of interesting developments in the field, while sensors are deactivated in quiescent locations. All computation and message passing is local , with no centralized control. Optimization is addressed through use of techniques in qualitative representation and reasoning, and efficient update through a dynamic and responsive underlying spatial framework. Effective deployment of very large arrays of sensors for environmental monitoring has important scientific and societal benefits. The project is integrated with the NSF IGERT program on Sensor Science, Engineering, and Informatics at the University of Maine, which will enhance educational and outreach opportunities. The project Web site (http://www.spatial.maine.edu/~worboys/sensors.html) will be used for broad results dissemination

    System Evolution, Feedback and Compliant Architectures

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    Proceedings, International Workshop on Feedback and Evolution in Software and Business Processes (FEAST 2000), Imperial College, London. Supported by EPSRCPostprintNon peer reviewe

    Instances and connectors : issues for a second generation process language

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    This work is supported by UK EPSRC grants GR/L34433 and GR/L32699Over the past decade a variety of process languages have been defined, used and evaluated. It is now possible to consider second generation languages based on this experience. Rather than develop a second generation wish list this position paper explores two issues: instances and connectors. Instances relate to the relationship between a process model as a description and the, possibly multiple, enacting instances which are created from it. Connectors refers to the issue of concurrency control and achieving a higher level of abstraction in how parts of a model interact. We believe that these issues are key to developing systems which can effectively support business processes, and that they have not received sufficient attention within the process modelling community. Through exploring these issues we also illustrate our approach to designing a second generation process language.Postprin

    An active-architecture approach to COTS integration

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    Commercial off-the-shelf (COTS) software products are increasingly used as standard components within integrated information systems. This creates challenges since both their developers and source code are not usually available, and the ongoing development of COTS cannot be predicted. The ArchWare Framework approach recognises COTS products as part of the ambient environment of an information system and therefore an important part of development is incorporating COTS as effective system components. This integration of COTS components, and the composition of components, is captured by an active architecture model which changes as the system evolves. Indeed the architecture modelling language used enables it to express the monitoring and evolution of a system. This active architecture model is structured using control system principles. By modelling both integration and evolution it can guide the system’s response to both predicted and emergent changes that arise from the use of COTS products.Publisher PDFPeer reviewe

    Role of shear stress in endothelial cell morphology and expression of cyclooxygenase isoforms

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    MEDLINE® is the source for the MeSH terms of this document.Objective-: The goal of this study was to examine the effect of chronic heterogeneous shear stress, applied using an orbital shaker, on endothelial cell morphology and the expression of cyclooxygenases 1 and 2. Methods and results-: Porcine aortic endothelial cells were plated on fibronectin-coated Transwell plates. Cells were cultured for up to 7 days either under static conditions or on an orbital shaker that generated a wave of medium inducing shear stress over the cells. Cells were fixed and stained for the endothelial surface marker CD31 or cyclooxygenases 1 and 2. En face confocal microscopy and scanning ion conductance microscopy were used to show that endothelial cells were randomly oriented at the center of the well, aligned with shear stress nearer the periphery, and expressed cyclooxygenase-1 under all conditions. Lipopolysaccharide induced cyclooxygenase-2 and the production of 6-keto-prostaglandin F1α in all cells. Conclusion-: Cyclooxygenase-1 is expressed in endothelial cells cultured under chronic shear stress of high or low directionality.Peer reviewedSubmitted Versio

    The role of blood flow in determining the sites of atherosclerotic plaques

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    Atherosclerosis is a chronic inflammatory disease characterized by the accumulation of lipids and inflammatory cells along the inner walls of arteries, and is an underlying cause of cardiovascular disease. Atherosclerotic lesions develop predominantly at branches, bends, and bifurcations in the arterial tree because these sites are exposed to low or disturbed blood flow, which exerts low/oscillatory shear stress on the vessel wall. This mechanical environment alters endothelial cell physiology by enhancing inflammatory activation. In contrast, regions of the arterial tree that are exposed to uniform, unidirectional blood flow and experience high shear stress are protected from inflammation and lesion development. Shear stress is sensed by the endothelium via mechanoreceptors and is subsequently transduced into biochemical signals resulting in modulation of proinflammatory signaling pathways. In this article, we address the molecular mechanisms behind the spatial localization of vascular inflammation and atherosclerosis, with particular focus on studies by our own group of two key proinflammatory signaling pathways, the mitogen-activated protein kinase pathway and the nuclear factor-kappa-B pathway

    Electronic Commerce Strategy in the UK Electricty Industry: The Case of Electric Co and Dataflow Software

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    This paper analyses the strategic business and IT response of Electric Co, a large electricity company, to deregulation and increased competition in the UK electricity industry. In common with deregulation in other markets such as North America and Australia, the UK regulator has specified strict regulations on how power generators, distribution and supply companies should interact with each other, and with business and consumer customers. In order to compete effectively Electric Co has implemented a novel dataflow solution that enables it to connect diverse internal systems to the external marketplace. An overview of changes in the market is related to the business and IT strategies of Electric Co. The link between the high-level business strategy and the actual use of IT architecture and systems is the design and management of the business processes that dictate how information is shared throughout the supply chain. The implementation of the regulator’s business process framework has been achieved through a novel use of a business process management solution. The major benefits are shown to be increased business flexibility. An outline of the broader implications of the research is given, in particular how developments in technical standards and business process management are related to communication theory and electronic markets

    IGERT: Sensor Science, Engineering, and Informatics

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    This Sensor Science, Engineering and Informatics (SSEI) IGERT program will provide multidisciplinary doctoral training in the area of sensor systems ranging from the science and engineering of new materials and sensing mechanisms to the interpretation of sensor data. The design and management of effective sensor systems requires a holistic understanding of how information is collected, stored, integrated, evaluated, and communicated within sensing systems and to decision makers in diverse application contexts. The SSEI IGERT weaves together three research focus areas: (1) Sensor Materials and Devices, (2) Sensor Systems and Networks, and (3) Sensor Informatics. The intellectual merit of the project includes education and research activities that are designed to ensure a feedback loop so that SSEI IGERT trainees are able to transform new knowledge from sensor-generated data to further development of sensor systems and networks and advances in sensor materials and devices, and vice versa. Innovative components of the program include (1) development and use of a testbed prototype that will require interdisciplinary interaction across the three research areas; (2) a tight integration of the social, legal, ethical, and economic dimensions of sensing environments in both research and training, (3) expanded relationships with companies and federal laboratories engaged in sensor research, (4) international collaborations, and (5) synergistic integration with sensor science and engineering education at the middle, high school, and undergraduate level. The broader impacts of the SSEI IGERT program are a new breed of scientists and engineers who will be versatile in dealing with the diverse technical components that contribute to sensing systems, knowledgeable in the legal, social, and ethical contexts of heavily sensed environments, and aware of the human values that must be preserved, protected and promoted within such systems. IGERT is an NSF-wide program intended to meet the challenges of educating U.S. Ph.D. scientists and engineers with the interdisciplinary background, deep knowledge in a chosen discipline, and the technical, professional, and personal skills needed for the career demands of the future. The program is intended to catalyze a cultural change in graduate education by establishing innovative new models for graduate education and training in a fertile environment for collaborative research that transcends traditional disciplinary boundaries
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