8 research outputs found

    Modeling complex cell regulation in the zebrafish circadian clock

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    The interdisciplinary "systems biology" approach of combining traditional biological investigations with tools from the mathematical and computer sciences has enabled novel insights into many highly complex and dynamic biological systems. The use of models has, for instance, revealed much about the intricate feedback mechanisms and acute importance of gene regulatory networks, and one such network of special note is our internal time keeper, or circadian clock. The circadian clock plays a pivotal role in modulating critical physiological processes, and has also been implicated, either directly or indirectly, in a whole range of pathological states. This research project investigates how the underlying dynamics of the circadian clock in the zebrafish model organism may be captured by a mathematical model, considering in particular the entrainment effect due to external cues such as light. Simulated data is contrasted with experimental results from different light regime experiments to validate the model and guide its refinement. Furthermore, various statistical methods are implemented to process the raw data and support its analysis. Extending the initial deterministic approach to take into account stochastic effects and additive population level effects emerges as a powerful means of representing the circadian signal decay in prolonged darkness, as well as light initiated re-synchronization as a strong component of entrainment. Consequently, it emerges that stochastic effects may be considered an essential feature of the circadian clock in zebrafish. A further cornerstone of the project is the implementation of an integrated simulation environment, including a Sequential Monte Carlo parameter estimation function, which succeeds in predicting a range of previously determined and also novel suitable parameter values. However, considerable difficulties in obtaining parameter values that satisfy the entire range of important target values simultaneously highlights the inherent complexity of accurately simulating the circadian clock

    Safety and Reliability - Safe Societies in a Changing World

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    The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

    Thrust Area Report, Engineering Research, Development and Technology

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    Iowa State University, Courses and Programs Catalog 2014–2015

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    The Iowa State University Catalog is a one-year publication which lists all academic policies, and procedures. The catalog also includes the following: information for fees; curriculum requirements; first-year courses of study for over 100 undergraduate majors; course descriptions for nearly 5000 undergraduate and graduate courses; and a listing of faculty members at Iowa State University.https://lib.dr.iastate.edu/catalog/1025/thumbnail.jp

    2009 Annual Progress Report: DOE Hydrogen Program

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    This report summarizes the hydrogen and fuel cell R&D activities and accomplishments of the DOE Hydrogen Program for FY2009. It covers the program areas of hydrogen production and delivery; fuel cells; manufacturing; technology validation; safety, codes and standards; education; and systems analysis
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