89 research outputs found
Isolation and characterization of the human A-myb promoter : regulation by NF-Y and Sp1
No full textThe A-myb transcription factor shows a restricted tissue distribution and is cell cycle regulated. Furthermore its deregulation has profound effects on the growth and/or differentiation of the cells in which it is normally expressed. We have therefore characterized its promoter. A 12 kb genomic clone was isolated that comprises the first exon, part of the first intron as well as upstream regulatory sequences. Multiple transcription start sites have been identified which operate in both B lymphocytes and epithelial cells and the upsteam region was shown to have promoter, activity. The boundaries of the minimal promoter region (-183-14), of a positive upstream (-538-183) and a negative downstream regulatory region (NRE) (+83+374) have been defined. The NRE is promoter- and orientation-independent but position specific. The A-myb minimal promoter is GC-rich, does not contain any TATA box but has a functional CCAAT box. The CCAAT box and minimal promoter is highly conserved in the corresponding murine sequence. The CCAAT box efficiently binds the NF-Y complex and its mutation decreases basal promoter activity by 50%. Two Sp1 binding sites are present upstream from the CCAAT box which can bind Sp1 and contribute to A-myb promoter activity by 70 and 30%, respectively. The two Sp1 sites and CCAAT box together contribute to over 80% of A-myb basal promoter activity and are therefore the major regulatory elements. Finally, we show that the promoter is cell cycle regulated and that the SP1 and CCAAT elements are required for S phase induction
Turbulence and Uncertainty for Future Renewable Energy Reliability
No full textCurrent climate change concerns accelerate interest in developing reliable renewable energy sources. Two of the most significant, in the wind and sea, are subject to turbulence, where its mathematics are at the forefront and the topic of this Conference.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Wind Energ
2.11 - Wind Turbine Reliability - Maintenance Strategies
No full textWind turbine technologies are evolving rapidly in terms of complexity and size and there is an urgent need for cost-effective Operations and Maintenance (O&M) strategies to increase the profitability of wind power assets.Component reliability as well as maintenance strategies have the greatest effect on O&M planning and costs, especially in offshore applications.This Chapter provides an overview of the state of the art in the field of wind turbine and wind farm reliability and maintenance, discussing the main points, lessons and opportunities learnt from both industry and academic experience.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Wind Energ
Myb-binding protein 1a is a nucleocytoplasmic shuttling protein that utilizes CRM1-dependent and independent nuclear export pathways
No full textCopyright © 2003 Elsevier Science (USA). All rights reserved.Myb-binding protein 1a (Mybbp1a) is a novel nuclear protein localized predominantly, but not exclusively, in nucleoli. Although initially isolated as a c-Myb interacting protein, Mybbp1a is expressed ubiquitously, associates with a number of different transcription factors, and may play a role in both RNA polymerase I- and II-mediated transcriptional regulation. However, its precise function remains unclear. In this study we show that Mybbp1a is a nucleocytoplasmic shuttling protein and investigate the mechanisms responsible for both nuclear import and export. The carboxyl terminus of Mybbp1a, which contains seven short basic amino acid repeat sequences, is responsible for both nuclear and nucleolar localization, and this activity can be transferred to a heterologous protein. Deletion mapping demonstrated that these repeat sequences appear to act incrementally, with successive deletions resulting in a corresponding increase in the proportion of protein localized in the cytoplasm. Glutathione S-transferase pulldown experiments showed that the nuclear receptor importin-/β mediates Mybbp1a nuclear import. Interspecies heterokaryons were used to demonstrate that Mybbp1a was capable of shuttling between the nucleus and the cytoplasm. Deletion analysis and in vivo export studies using a heterologous assay system identified several nuclear export sequences which facilitate Mybbp1a nuclear export of Mybbp1a by CRM1-dependent and -independent pathways.Rebecca A. Keough, Elizabeth M. Macmillan, Jodi K. Lutwyche, Jennifer M. Gardner, Fiona J. Tavner, David A. Jans, Beric R. Henderson and Thomas J. Gondadhttp://www.elsevier.com/wps/find/journaldescription.cws_home/622826/description#descriptio
Is it really about the trees? Exploring the roots of resistance to tree-planting on the Welsh commons
No full textThe research conducted for and presented in this paper was granted ethical approval by the SPAIS Research Ethics Committee, University of Bristol. The empirical data collection and initial write up were undertaken by the first author while at the University of Bristol. Written informed consent for publication was obtained from Stump up for Trees. We are grateful to the owners and graziers of the Welsh commons and to the staff at Stump up for Trees, all of whom generously shared their time, their knowledge, their experience and in some cases their kitchens and cake. We also thank the Scottish Geographical Journal's three anonymous reviewers and Editor in Chief Chris Philo; their supportive and constructive comments guided us in the shaping of this paper.Peer reviewe
Improved cost energy comparison of permanent magnet generators for large offshore wind turbines
No full textThis paper investigates geared and direct-drive permanent magnet generators for a typical offshore wind turbine, providing a detailed comparison of various wind turbine drivetrain configurations in order to minimise the Cost of Energy. The permanent magnet generator topologies considered include a direct-drive machine and single stage, two-stage or three-stage gearbox driven generators. The cost of energy calculations are based on initial capital costs, the costs of manufacture, installation, operations and maintenance, with particular focus on improved calculations of the annual energy yield with better availability estimations and gearbox loss modelling
Molecular cloning reveals that the p160 Myb-binding protein is a novel, predominantly necleolar protein which may play a role in transactivation by Myb
Get PDFWe have previously detected two related murine nuclear proteins, p160 and p67, that can bind to the leucine zipper motif within the negative regulatory domain of the Myb transcription factor. We now describe the molecular cloning of cDNA corresponding to murine p160. The P160 gene is located on mouse chromosome 11, and related sequences are found on chromosomes 1 and 12. The predicted p160 protein is novel, and in agreement with previous studies, we find that the corresponding 4.5-kb mRNA is ubiquitously expressed. We showed that p67 is an N-terminal fragment of p160 which is generated by proteolytic cleavage in certain cell types. The protein encoded by the cloned p160 cDNA and an engineered protein (p67*) comprising the amino-terminal region of p160 exhibit binding specificities for the Myb and Jun leucine zipper regions identical to those of endogenous p160 and p67, respectively. This implies that the Myb-binding site of p160 lies within the N-terminal 580 residues and that the Jun-binding site is C-terminal to this position. Moreover, we show that p67* but not p160 can inhibit transactivation by Myb. Unexpectedly, immunofluorescence studies show that p160 is localized predominantly in the nucleolus. The implications of these results for possible functions of p160 are discussed.Fiona J. Tavner, Richard Simpson, Shigeki Tashiro, Diane Favier, Nancy A. Jenkins, Debra J. Gilbert, Neal G. Copeland, Elizabeth M. Macmillan, Jodi Lutwyche, Rebecca A. Keough, Shunsuke Ishii and Thomas J. Gond
Vessel charter rate estimation for offshore wind O&M activities
Get PDFEstimating the cost of vessels is an important factor for the operation & maintenance (O&M) costs of offshore wind farms. Accurate cost estimation is required during operation of the wind farm. This paper presents the development of the O&M charter rate modelling for offshore wind turbine jack-up vessels under different op-erational strategies. The main objectives of this modelling are to explore the differentiation of charter rates as-sociated with the charter periods and with the capabilities of different vessels; as well as to allow offshore wind farm operators to plan their maintenance strategies through considering the share of vessels’ costs in the overall maintenance costs. In this respect, various jack-up vessels in the offshore wind industry are investigat-ed and the most effective charter periods are identified. The seasonal effects on the charter rates are also con-sidered to provide critical insight into the selection of the optimum charter rate scenario
Wind Turbine Generator Condition Monitoring via the Generator Control Loop
Get PDFThis thesis focuses on the development of condition monitoring techniques for application in wind turbines, particularly for offshore wind turbine driven doubly fed
induction generators. The work describes the significant development of a physical condition monitoring Test Rig and its MATLAB Simulink model to represent modern variable speed wind turbine and the innovation and application of the rotor side control signals for the generator fault detection. Work has been carried out to develop a physical condition monitoring Test Rig from open loop control, with a wound rotor induction generator, into closed loop control with a doubly fed induction generator. This included designing and building the rotor side converter, installing the back-to-back converter and other new instrumentation. Moreover, the MATLAB Simulink model of the Test Rig has been developed to represent the closed loop control, with more detailed information on the Rig components and instrumentation and has been validated against the physical system in the time and frequency domains. A fault detection technique has been proposed by the author based on frequency analysis of the rotor-side control signals, namely; d-rotor current error, q-rotor current error and q-rotor current, for wind turbine generator fault detection. This technique has been investigated for rotor electrical asymmetry on the physical Test Rig and its MATLAB Simulink model at different fixed and variable speed conditions. The sensitivity of the each proposed signal has been studied under different operating conditions. Measured and simulated results are presented, a comparison with the results from using stator current and total power has been addressed and the improvement in condition monitoring detection performance has been demonstrated in comparison with previous methods, looking at current, power and vibration analysis
Improving the reliability of wind turbine generation and its impact on overall distribution network reliability
No full text- …
