WorldWideScience

Sample records for highly synchronized cell

  1. High-order synchronization of hair cell bundles

    Science.gov (United States)

    Levy, Michael; Molzon, Adrian; Lee, Jae-Hyun; Kim, Ji-Wook; Cheon, Jinwoo; Bozovic, Dolores

    2016-12-01

    Auditory and vestibular hair cell bundles exhibit active mechanical oscillations at natural frequencies that are typically lower than the detection range of the corresponding end organs. We explore how these noisy nonlinear oscillators mode-lock to frequencies higher than their internal clocks. A nanomagnetic technique is used to stimulate the bundles without an imposed mechanical load. The evoked response shows regimes of high-order mode-locking. Exploring a broad range of stimulus frequencies and intensities, we observe regions of high-order synchronization, analogous to Arnold Tongues in dynamical systems literature. Significant areas of overlap occur between synchronization regimes, with the bundle intermittently flickering between different winding numbers. We demonstrate how an ensemble of these noisy spontaneous oscillators could be entrained to efficiently detect signals significantly above the characteristic frequencies of the individual cells.

  2. Acoustophoretic Synchronization of Mammalian Cells in Microchannels

    DEFF Research Database (Denmark)

    Thévoz, P.; Adams, J.D.; Shea, H.

    2010-01-01

    We report the first use of ultrasonic standing waves to achieve cell cycle phase synchronization in mammalian cells in a high-throughput and reagent-free manner. The acoustophoretic cell synchronization (ACS) device utilizes volume-dependent acoustic radiation force within a microchannel...... to selectively purify target cells of desired phase from an asynchronous mixture based on cell cycle-dependent fluctuations in size. We show that ultrasonic separation allows for gentle, scalable, and label-free synchronization with high G1 phase synchrony (84%) and throughput (3 × 106 cells/h per microchannel)....

  3. Acoustophoretic Synchronization of Mammalian Cells in Microchannels

    DEFF Research Database (Denmark)

    Thévoz, P.; Adams, J.D.; Shea, H.

    2010-01-01

    We report the first use of ultrasonic standing waves to achieve cell cycle phase synchronization in mammalian cells in a high-throughput and reagent-free manner. The acoustophoretic cell synchronization (ACS) device utilizes volume-dependent acoustic radiation force within a microchannel...... to selectively purify target cells of desired phase from an asynchronous mixture based on cell cycle-dependent fluctuations in size. We show that ultrasonic separation allows for gentle, scalable, and label-free synchronization with high G1 phase synchrony (84%) and throughput (3 × 106 cells/h per microchannel)....

  4. Highly Synchronized Expression of Lineage-Specific Genes during In Vitro Hepatic Differentiation of Human Pluripotent Stem Cell Lines

    Directory of Open Access Journals (Sweden)

    Nidal Ghosheh

    2016-01-01

    Full Text Available Human pluripotent stem cells- (hPSCs- derived hepatocytes have the potential to replace many hepatic models in drug discovery and provide a cell source for regenerative medicine applications. However, the generation of fully functional hPSC-derived hepatocytes is still a challenge. Towards gaining better understanding of the differentiation and maturation process, we employed a standardized protocol to differentiate six hPSC lines into hepatocytes and investigated the synchronicity of the hPSC lines by applying RT-qPCR to assess the expression of lineage-specific genes (OCT4, NANOG, T, SOX17, CXCR4, CER1, HHEX, TBX3, PROX1, HNF6, AFP, HNF4a, KRT18, ALB, AAT, and CYP3A4 which serve as markers for different stages during liver development. The data was evaluated using correlation and clustering analysis, demonstrating that the expression of these markers is highly synchronized and correlated well across all cell lines. The analysis also revealed a distribution of the markers in groups reflecting the developmental stages of hepatocytes. Functional analysis of the differentiated cells further confirmed their hepatic phenotype. Taken together, these results demonstrate, on the molecular level, the highly synchronized differentiation pattern across multiple hPSC lines. Moreover, this study provides additional understanding for future efforts to improve the functionality of hPSC-derived hepatocytes and thereby increase the value of related models.

  5. Fission Yeast Cell Cycle Synchronization Methods.

    Science.gov (United States)

    Tormos-Pérez, Marta; Pérez-Hidalgo, Livia; Moreno, Sergio

    2016-01-01

    Fission yeast cells can be synchronized by cell cycle arrest and release or by size selection. Cell cycle arrest synchronization is based on the block and release of temperature-sensitive cell cycle mutants or treatment with drugs. The most widely used approaches are cdc10-129 for G1; hydroxyurea (HU) for early S-phase; cdc25-22 for G2, and nda3-KM311 for mitosis. Cells can also be synchronized by size selection using centrifugal elutriation or a lactose gradient. Here we describe the methods most commonly used to synchronize fission yeast cells.

  6. Bilateral synchronous high-grade serous carcinoma and clear cell carcinoma in right and left ovaries with immunohistochemical confirmation: An exceptional finding

    Directory of Open Access Journals (Sweden)

    Agarwal Preeti

    2014-01-01

    Full Text Available Synchronous epithelial or mixed epithelial and germ cells tumors in the same ovary is a recognized event, however, having two different surface epithelial tumors in contra lateral ovaries is a rare occurrence; prognosis and pathogenesis of which is still not clear. We came across similar finding in a 60-year-old female with different types of surface epithelial neoplasm in right and left ovaries at the same time; both of which were malignant. Clinicoradiologically only the left ovary revealed tumor, right ovary was atrophic. To our surprise, left ovary revealed high grade serous carcinoma and the right ovary displayed clear cell carcinoma. We performed immunohistochemistry to rule out the possibility of clear cell variant of serous papillary carcinoma. On literature search, we found; only single case with synchronous presentation of two different surface epithelial ovarian tumors in the same patient, both of which were benign.

  7. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1996-01-01

    The purpose of Phase 1 of the study is to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. The systems we consider are high data rate space communication systems. Also......, the systems use some form of QPSK modulation and transmit data in frames separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system...... components. Node synchronization performed within a Viterbi decoder is discussed, and algorithms for frame synchronization are described and analyzed. We present a list of system configurations that we find potentially useful. Further, the high level architecture of units that contain frame synchronization...

  8. Bioreactor and methods for producing synchronous cells

    Science.gov (United States)

    Helmstetter, Charles E. (Inventor); Thornton, Maureen (Inventor); Gonda, Steve (Inventor)

    2005-01-01

    Apparatus and methods are directed to a perfusion culture system in which a rotating bioreactor is used to grow cells in a liquid culture medium, while these cells are attached to an adhesive-treated porous surface. As a result of this arrangement and its rotation, the attached cells divide, with one cell remaining attached to the substrate, while the other cell, a newborn cell is released. These newborn cells are of approximately the same age, that are collected upon leaving the bioreactor. The populations of newborn cells collected are of synchronous and are minimally, if at all, disturbed metabolically.

  9. High Speed Frame Synchronization and Viterbi Decoding

    DEFF Research Database (Denmark)

    Paaske, Erik; Justesen, Jørn; Larsen, Knud J.

    1998-01-01

    The study has been divided into two phases. The purpose of Phase 1 of the study was to describe the system structure and algorithms in sufficient detail to allow drawing the high level architecture of units containing frame synchronization and Viterbi decoding. After selection of which specific...... separated by a sync marker and protected by error-correcting codes. We first give a survey of trends within the area of space modulation systems. We then discuss and define the interfaces and operating modes of the relevant system components. We present a list of system configurations that we find...... potentially useful.Algorithms for frame synchronization are described and analyzed. Further, the high level architecture of units that contain frame synchronization and various other functions needed in a complete system is presented. Two such units are described, one for placement before the Viterbi decoder...

  10. Cell-body rocking is a dominant mechanism for flagellar synchronization in a swimming alga.

    Science.gov (United States)

    Geyer, Veikko F; Jülicher, Frank; Howard, Jonathon; Friedrich, Benjamin M

    2013-11-05

    The unicellular green alga Chlamydomonas swims with two flagella that can synchronize their beat. Synchronized beating is required to swim both fast and straight. A long-standing hypothesis proposes that synchronization of flagella results from hydrodynamic coupling, but the details are not understood. Here, we present realistic hydrodynamic computations and high-speed tracking experiments of swimming cells that show how a perturbation from the synchronized state causes rotational motion of the cell body. This rotation feeds back on the flagellar dynamics via hydrodynamic friction forces and rapidly restores the synchronized state in our theory. We calculate that this "cell-body rocking" provides the dominant contribution to synchronization in swimming cells, whereas direct hydrodynamic interactions between the flagella contribute negligibly. We experimentally confirmed the two-way coupling between flagellar beating and cell-body rocking predicted by our theory.

  11. Mechanical communication in cardiac cell synchronized beating

    Science.gov (United States)

    Nitsan, Ido; Drori, Stavit; Lewis, Yair E.; Cohen, Shlomi; Tzlil, Shelly

    2016-05-01

    Cell-cell communication, which enables cells to coordinate their activity and is essential for growth, development and function, is usually ascribed a chemical or electrical origin. However, cells can exert forces and respond to environment elasticity and to mechanical deformations created by their neighbours. The extent to which this mechanosensing ability facilitates intercellular communication remains unclear. Here we demonstrate mechanical communication between cells directly for the first time, providing evidence for a long-range interaction that induces long-lasting alterations in interacting cells. We show that an isolated cardiac cell can be trained to beat at a given frequency by mechanically stimulating the underlying substrate. Deformations are induced using an oscillatory mechanical probe that mimics the deformations generated by a beating neighbouring cardiac cell. Unlike electrical field stimulation, the probe-induced beating rate is maintained by the cell for an hour after the stimulation stops, implying that long-term modifications occur within the cell. These long-term alterations provide a mechanism for cells that communicate mechanically to be less variable in their electromechanical delay. Mechanical coupling between cells therefore ensures that the final outcome of action potential pacing is synchronized beating. We further show that the contractile machinery is essential for mechanical communication.

  12. Synchronization dynamics of chemically coupled cells with activator–inhibitor pathways

    Energy Technology Data Exchange (ETDEWEB)

    Guemkam Ghomsi, P. [Complex Systems and Theoretical Biology Group, Laboratory of Research on Advanced Materials and Nonlinear Science (LaRAMaNS), Department of Physics, Faculty of Science, University of Buea, P.O. Box 63, Buea (Cameroon); Laboratoire de Mécanique, Department of Physics, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé (Cameroon); Moukam Kakmeni, F.M., E-mail: moukam.kakmeni@ubuea.cm [Complex Systems and Theoretical Biology Group, Laboratory of Research on Advanced Materials and Nonlinear Science (LaRAMaNS), Department of Physics, Faculty of Science, University of Buea, P.O. Box 63, Buea (Cameroon); Kofane, T.C.; Tchawoua, C. [Laboratoire de Mécanique, Department of Physics, Faculty of Science, University of Yaoundé I, P.O. Box 812, Yaoundé (Cameroon)

    2014-08-01

    Systems of interacting cells containing an activator–inhibitor pathway, regulating naturally in their inner parts their end-product concentrations through a sequence of biochemical reactions with feedback-loops: an end-product inhibition of the first substrate, and an autocatalytic activation of the end-product through an allosteric enzyme-mediated reaction are investigated. The individual cells are considered to be identical and are described by nonlinear differential equations recently proposed following the concerted transition model. The chemical and electrical coupling types, realized by exchange of metabolites across concentration of the cells are used in order to analyze the onset of phase and complete synchronization in the biochemical system. It is found that depending on the coupling nature and the range of coupling strength, cells enter into different synchronization regimes going from low-quality to high-quality synchronization. The synchronization manifold's stability is analyzed. The results are supported by numerical simulations using indicators such as the conditional Lyapunov exponents and the rate of change of the Lyapunov function. The results indicate that the system cannot completely synchronize under the single action of the chemical coupling. The combined effect of both chemical and electrical couplings is found to be of capital importance in the onset of complete synchronization and high quality synchronization. - Highlights: • We investigate the dynamics and synchronization of cells with activator–inhibitor pathways. • A complete study of fixed points' stability and bifurcations of the system is done. • It is found that chemically coupled cells only display phase synchronization. • Electrical coupling is important for complete synchronization in the coupled cells. • High quality synchronization is observed in the coupled cells.

  13. Combined myeloid cell synchronization and chromosome G-banding by bromodeoxyuridine.

    Science.gov (United States)

    Lemieux, N; Richer, C L; Jean, P

    1987-10-01

    A combined high-resolution G-banding technique and cell synchronization of bone marrow cultures by BrdU is presented and compared with direct technique, standard 24-hour culture, and synchronization both with low temperature and methotrexate. Mitotic count and quality of spreading are improved in comparison with unsynchronized techniques. Precision of banding is increased significantly compared with the four other techniques used. Our procedure, which presents the advantage of combined synchronization and banding, is simple, time-saving, and provides more information about the chromosomes. Our results suggest that the GB-FPG technique should be a method of choice for the synchronization of bone marrow cells.

  14. Synchronization of Green Algae by Light and Dark Regimes for Cell Cycle and Cell Division Studies.

    Science.gov (United States)

    Hlavová, Monika; Vítová, Milada; Bišová, Kateřina

    2016-01-01

    A synchronous population of cells is one of the prerequisites for studying cell cycle processes such as DNA replication, nuclear and cellular division. Green algae dividing by multiple fission represent a unique single cell system enabling the preparation of highly synchronous cultures by application of a light-dark regime similar to what they experience in nature. This chapter provides detailed protocols for synchronization of different algal species by alternating light-dark cycles; all critical points are discussed extensively. Moreover, detailed information on basic analysis of cell cycle progression in such cultures is presented, including analyses of nuclear, cellular, and chloroplast divisions. Modifications of basic protocols that enable changes in cell cycle progression are also suggested so that nuclear or chloroplast divisions can be followed separately.

  15. High Efficiency Synchronous Rectification in Spacecraft

    Science.gov (United States)

    Krauhamer, S.; Das, R.; Vorperian, V.; White, J.; Bennett, J.; Rogers, D.

    1993-01-01

    This paper examines the implementaion of MOSFETs as synchronous rectifiers which results in a substantial improvement in power processing efficency and therefore may result in significant reduction of spacecraft mass and volum for the same payload.

  16. High Efficiency Synchronous Rectification in Spacecraft

    Science.gov (United States)

    Krauhamer, S.; Das, R.; Vorperian, V.; White, J.; Bennett, J.; Rogers, D.

    1993-01-01

    This paper examines the implementaion of MOSFETs as synchronous rectifiers which results in a substantial improvement in power processing efficency and therefore may result in significant reduction of spacecraft mass and volum for the same payload.

  17. Synchronous sigmoid and caecal cancers together with a primary renal cell carcinoma.

    LENUS (Irish Health Repository)

    Bhargava, A

    2012-06-01

    Multiple primary neoplasms, a common clinical entity, can be classified as synchronous or metachronous. Renal cell carcinoma, in particular, is associated with a high rate of multiple primary neoplasms.

  18. Distributed Initial Synchronization for 5G small cells

    DEFF Research Database (Denmark)

    Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão; Tirkkonen, Olav

    2014-01-01

    Time synchronization in a large network of small cells enables efficient interference management as well as advanced transmission techniques which can boost the network throughput. In this paper, we focus on the distributed initial synchronization problem and propose different solutions aiming at...

  19. Collective cell movement promotes synchronization of coupled genetic oscillators.

    Science.gov (United States)

    Uriu, Koichiro; Morelli, Luis G

    2014-07-15

    Collective cell movement is a crucial component of embryonic development. Intercellular interactions regulate collective cell movement by allowing cells to transfer information. A key question is how collective cell movement itself influences information flow produced in tissues by intercellular interactions. Here, we study the effect of collective cell movement on the synchronization of locally coupled genetic oscillators. This study is motivated by the segmentation clock in zebrafish somitogenesis, where short-range correlated movement of cells has been observed. We describe the segmentation clock tissue by a Voronoi diagram, cell movement by the force balance of self-propelled and repulsive forces between cells, the dynamics of the direction of self-propelled motion, and the synchronization of genetic oscillators by locally coupled phase oscillators. We find that movement with a correlation length of about 2 ∼ 3 cell diameters is optimal for the synchronization of coupled oscillators. Quantification of cell mixing reveals that this short-range correlation of cell movement allows cells to exchange neighbors most efficiently. Moreover, short-range correlated movement strongly destabilizes nonuniform spatial phase patterns, further promoting global synchronization. Our theoretical results suggest that collective cell movement may enhance the synchronization of the segmentation clock in zebrafish somitogenesis. More generally, collective cell movement may promote information flow in tissues by enhancing cell mixing and destabilizing spurious patterns.

  20. A SYNCHRONIZATION ALGORITHM FOR HF (HIGH FREQUENCY) BROADBAND OFDM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Yang Lei; Zhang You'ai

    2008-01-01

    In this letter, a kind of associated synchronization algorithm which is suitable for HF (High Frequency) broadband OFDM (Orthogonal Frequency Division Multiplexing) system is presented based on describing and constructing the GMW (Gorden, Mills and Welch) sequence. The algorithm is based on the Schmidl and Minn's symbol timing principle, the constructed GMW sequence is transmitted and disposed, and the synchronization is adjudicated using the correlation of GMW sequence. The simulation result indicates that this algorithm has high performance synchronization ability under the low SNR (Signal to Noise Ratio) at two different kinds of channel models.

  1. Availability Analysis for High Voltage Synchronous Motor

    Institute of Scientific and Technical Information of China (English)

    DING Jin-hua; Erland Olsson; ZHOU Rong

    2004-01-01

    The operating experience data for 34 motors running for approximately 15 years in paper plants are collected. According to the data set, the reliability and availability characteristics of a highvoltage synchronous motor are analyzed based on the Markov Model. The unit or subsystem main rotor with windings in the motor system is more important for the motor system's availability, though its failure rate is lower compared to other units. Preventive maintenance is first introduced as a state in the markov Model for the motor system.

  2. Collective Cell Movement Promotes Synchronization of Coupled Genetic Oscillators

    OpenAIRE

    Uriu, Koichiro; Morelli, Luis G.

    2014-01-01

    Collective cell movement is a crucial component of embryonic development. Intercellular interactions regulate collective cell movement by allowing cells to transfer information. A key question is how collective cell movement itself influences information flow produced in tissues by intercellular interactions. Here, we study the effect of collective cell movement on the synchronization of locally coupled genetic oscillators. This study is motivated by the segmentation clock in zebrafish somito...

  3. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall.

    Science.gov (United States)

    Jacobsen, Jens Christian Brings; Aalkjaer, Christian; Matchkov, Vladimir V; Nilsson, Holger; Freiberg, Jacob J; Holstein-Rathlou, Niels-Henrik

    2008-10-13

    Vascular smooth muscle cells (SMCs) exhibit different types of calcium dynamics. Static vascular tone is associated with unsynchronized calcium waves and the developed force depends on the number of recruited cells. Global calcium transients synchronized among a large number of cells cause rhythmic development of force known as vasomotion. We present experimental data showing a considerable heterogeneity in cellular calcium dynamics in the vascular wall. In stimulated vessels, some SMCs remain quiescent, whereas others display waves of variable frequency. At the onset of vasomotion, all SMCs are enrolled into synchronized oscillation. Simulations of coupled SMCs show that the experimentally observed cellular recruitment, the presence of quiescent cells and the variation in oscillation frequency may arise if the cell population is phenotypically heterogeneous. In this case, quiescent cells can be entrained at the onset of vasomotion by the collective driving force from the synchronized oscillations in the membrane potential of the surrounding cells. Partial synchronization arises with an increase in the concentration of cyclic guanosine monophosphate, but in a heterogeneous cell population complete synchronization also requires a high-conductance pathway that provides strong coupling between the cells.

  4. An integrated system for synchronous culture of animal cells under controlled conditions.

    Science.gov (United States)

    Mendoza-Pérez, Elena; Hernández, Vanessa; Palomares, Laura A; Serrato, José A

    2016-01-01

    The cell cycle has fundamental effects on cell cultures and their products. Tools to synchronize cultured cells allow the study of cellular physiology and metabolism at particular cell cycle phases. However, cells are most often arrested by methods that alter their homeostasis and are then cultivated in poorly controlled environments. Cell behavior could then be affected by the synchronization method and culture conditions used, and not just by the particular cell cycle phase under study. Moreover, only a few viable cells are recovered. Here, we designed an integrated system where a large number of cells from a controlled bioreactor culture is separated by centrifugal elutriation at high viabilities. In contrast to current elutriation methods, cells are injected directly from a bioreactor into an injection loop, allowing the introduction of a large number of cells into the separation chamber without stressful centrifugation. A low pulsation peristaltic pump increases the stability of the elutriation chamber. Using this approach, a large number of healthy cells at each cell cycle phase were obtained, allowing their direct inoculation into fully instrumented bioreactors. Hybridoma cells synchronized and cultured in this system behaved as expected for a synchronous culture.

  5. Synchronization of Caulobacter crescentus for investigation of the bacterial cell cycle.

    Science.gov (United States)

    Schrader, Jared M; Shapiro, Lucy

    2015-04-08

    The cell cycle is important for growth, genome replication, and development in all cells. In bacteria, studies of the cell cycle have focused largely on unsynchronized cells making it difficult to order the temporal events required for cell cycle progression, genome replication, and division. Caulobacter crescentus provides an excellent model system for the bacterial cell cycle whereby cells can be rapidly synchronized in a G0 state by density centrifugation. Cell cycle synchronization experiments have been used to establish the molecular events governing chromosome replication and segregation, to map a genetic regulatory network controlling cell cycle progression, and to identify the establishment of polar signaling complexes required for asymmetric cell division. Here we provide a detailed protocol for the rapid synchronization of Caulobacter NA1000 cells. Synchronization can be performed in a large-scale format for gene expression profiling and western blot assays, as well as a small-scale format for microscopy or FACS assays. The rapid synchronizability and high cell yields of Caulobacter make this organism a powerful model system for studies of the bacterial cell cycle.

  6. Synchronization of the Noisy Electrosensitive Cells in the Paddlefish

    Energy Technology Data Exchange (ETDEWEB)

    Neiman, A.; Pei, X.; Russell, D.; Wojtenek, W.; Wilkens, L.; Moss, F. [Center for Neurodynamics, University of Missouri at St. Louis, St. Louis, Missouri 63121 (United States); Braun, H.A.; Voigt, K. [Institute of Physiology, University of Marburg, Marburg 35037 (Germany); Huber, M.T. [Institute of Psychiatry, University of Marburg, Marburg 35037 (Germany)

    1999-01-01

    Synchronization of electrosensitive cells of the paddlefish is studied by means of electrophysiological experiments. Different types of noisy phase locked regimes are observed. The experimental data are compared with computer simulations of a noise-mediated modified Hodgkin-Huxley neuron model and of a stochastic circle map. {copyright} {ital 1999} {ital The American Physical Society }

  7. Synchronization of glycolytic oscillations in a yeast cell population

    DEFF Research Database (Denmark)

    Dano, S.; Hynne, F.; De Monte, Silvia

    2001-01-01

    The mechanism of active phase synchronization in a suspension of oscillatory yeast cells has remained a puzzle for almost half a century. The difficulty of the problem stems from the fact that the synchronization phenomenon involves the entire metabolic network of glycolysis and fermentation......, and consequently it cannot be addressed at the level of a single enzyme or a single chemical species. In this paper it is shown how this system in a CSTR (continuous flow stirred tank reactor) can be modelled quantitatively as a population of Stuart-Landau oscillators interacting by exchange of metabolites through...

  8. Bursting Ca2+ Oscillations and Synchronization in Coupled Cells

    Institute of Scientific and Technical Information of China (English)

    JI Quan-Bao; LU Qi-Shao; Yang Zhuo-Qin; Duan Li-Xia

    2008-01-01

    A mathematical model proposed by Grubelnk et al. [Biophys. Chem. 94 (2001) 59] is employed to study the physiological role of mitochondria and the cytosolic proteins in generating complex Ca2+ oscillations. Intracellular bursting calcium oscillations of point-point, point cycle and two-folded limit cycle types are observed and explanations are given based on the fast/slow dynamical analysis, especially for point-cycle and two-folded limit cycle types, which have not been reported before. Furthermore, synchronization of coupled bursters of Ca2+oscillations via gap junctions and the effect of bursting types on synchronization of coupled cells are studied. It is argued that bursting oscillations of point-point type may be superior to achieve synchronization than that of point-cycle type.

  9. Experiences of Advanced High School Students in Synchronous Online Recitations

    Science.gov (United States)

    Mayer, Greg; Lingle, Jeremy; Usselman, Marion

    2017-01-01

    The question of how to best design an online course that promotes student-centred learning is an area of ongoing research. This mixed-methods study focused on a section of advanced high school students, in college-level mathematics courses, that used a synchronous online environment mediated over web-conferencing software, and whether the…

  10. Synchronous thyroid carcinoma and squamous cell carcinoma. A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Seo [Chonnam National Univ. School of Dentistry, Kwangju (Korea, Republic of)

    2006-12-15

    Thyroid carcinoma occurring as a second primary associated with head and neck squamous cell carcinoma (SCC) is unusual. This report presents a synchronous thyroid carcinoma and squamous cell carcinoma in the anterior palate region of a 41-year-old man. The clinical, radiologic, and histologic features are described. At 10-month follow-up after operation, no evidence of recurrence ana metastasis was present.

  11. A New Approach to Implement Synchronous Demultiplexers inHigh-Speed ISDN Switching Network

    Institute of Scientific and Technical Information of China (English)

    叶航军; 刘斌

    2001-01-01

    This paper proves that a synchronous demultiplexer has the samelogic function as a synchronous multiplexer. A new approach is proposed to implement synchronous demultiplexers in high-speed ISDN switching networks. A synchronous demultiplexer is designed utilizing the same structure as a synchronous shuffle multiplexer. Both the theoretical analysis and experimental results show that for the same capacity, the new method is more tolerant of signal delay variation, so a very high-speed synchronous demultiplexer can be designed with the larger capacity required in large capacity synchronous switching networks.

  12. Synchronization of glycolytic oscillations in a yeast cell population

    DEFF Research Database (Denmark)

    Dano, S.; Hynne, F.; De Monte, Silvia

    2001-01-01

    the extracellular medium, thus reducing the complexity of the problem without sacrificing the biochemical realism. The parameters of the model can be derived by a systematic expansion from any full-scale model of the yeast cell kinetics with a supercritical Hopf bifurcation. Some parameter values can also......The mechanism of active phase synchronization in a suspension of oscillatory yeast cells has remained a puzzle for almost half a century. The difficulty of the problem stems from the fact that the synchronization phenomenon involves the entire metabolic network of glycolysis and fermentation...... be obtained directly from analysis of perturbation experiments. In the mean-field limit, equations for the study of populations having a distribution of frequencies are used to simulate the effect of the inherent variations between cells....

  13. Synchronous Occurrence of Chronic Myeloid Leukemia and Mantle Cell Lymphoma

    Directory of Open Access Journals (Sweden)

    Prajwol Pathak

    2017-01-01

    Full Text Available Chronic myeloid leukemia (CML and mantle cell lymphoma (MCL are hematologic malignancies that originate from different oligopotent progenitor stem cells, namely, common myeloid and lymphoid progenitor cells, respectively. Although blastic transformation of CML can occur in the lymphoid lineage and CML has been related to non-Hodgkin lymphoma on transformation, to our knowledge, de novo and synchronous occurrence of CML and MCL has not been reported. Herein, we report the first case of synchronous CML and MCL in an otherwise healthy 38-year-old man. Potential etiologies and pathological relationships between the two malignancies are explored, including the possibility that the downstream effects of BCR-ABL may link it to an overexpression of cyclin D1, which is inherent to the etiology of MCL.

  14. Multicentric Giant Cell Tumor of Bone: Synchronous and Metachronous Presentation

    Directory of Open Access Journals (Sweden)

    Reiner Wirbel

    2013-01-01

    Full Text Available A 27-year-old man treated 2.5 years ago for synchronous multicentric giant cell tumor of bone located at the right proximal humerus and the right 5th finger presented now with complaints of pain in his right hip and wrist of two-month duration. Radiology and magnetic resonance revealed multicentric giant cell tumor lesions of the right proximal femur, the left ileum, the right distal radius, and the left distal tibia. The patient has an eighteen-year history of a healed osteosarcoma of the right tibia that was treated with chemotherapy, resection, and allograft reconstruction. A literature review establishes this as the first reported case of a patient with synchronous and metachronous multicentric giant cell tumor who also has a history of osteosarcoma.

  15. Live-cell monitoring of periodic gene expression in synchronous human cells identifies Forkhead genes involved in cell cycle control.

    Science.gov (United States)

    Grant, Gavin D; Gamsby, Joshua; Martyanov, Viktor; Brooks, Lionel; George, Lacy K; Mahoney, J Matthew; Loros, Jennifer J; Dunlap, Jay C; Whitfield, Michael L

    2012-08-01

    We developed a system to monitor periodic luciferase activity from cell cycle-regulated promoters in synchronous cells. Reporters were driven by a minimal human E2F1 promoter with peak expression in G1/S or a basal promoter with six Forkhead DNA-binding sites with peak expression at G2/M. After cell cycle synchronization, luciferase activity was measured in live cells at 10-min intervals across three to four synchronous cell cycles, allowing unprecedented resolution of cell cycle-regulated gene expression. We used this assay to screen Forkhead transcription factors for control of periodic gene expression. We confirmed a role for FOXM1 and identified two novel cell cycle regulators, FOXJ3 and FOXK1. Knockdown of FOXJ3 and FOXK1 eliminated cell cycle-dependent oscillations and resulted in decreased cell proliferation rates. Analysis of genes regulated by FOXJ3 and FOXK1 showed that FOXJ3 may regulate a network of zinc finger proteins and that FOXK1 binds to the promoter and regulates DHFR, TYMS, GSDMD, and the E2F binding partner TFDP1. Chromatin immunoprecipitation followed by high-throughput sequencing analysis identified 4329 genomic loci bound by FOXK1, 83% of which contained a FOXK1-binding motif. We verified that a subset of these loci are activated by wild-type FOXK1 but not by a FOXK1 (H355A) DNA-binding mutant.

  16. SynUTC - high precision time synchronization over ethernet networks

    CERN Document Server

    Höller, R; Horauer, M; Kerö, N; Schmid, U; Schossmaier, K

    2002-01-01

    This article describes our SynUTC (Synchronized Universal Time Coordinated) technology, which enables high-accuracy distribution of GPS time and time synchronization of network nodes connected via standard Ethernet LANs. By means of exchanging data packets in conjunction with moderate hardware support at nodes and switches, an overall worst-case accuracy in the range of some 100 ns can be achieved, with negligible communication overhead. Our technology thus improves the 1 ms-range accuracy achievable by conventional, software-based approaches like NTP by 4 orders of magnitude. Applications can use the high-accuracy global time provided by SynUTC for event timestamping and event generation both at hardware and software level. SynUTC is based upon inserting highly accurate time information into dedicated data packets at the media-independent interface (MII) between the physical layer transceiver and the network controller upon packet transmission and reception, respectively. As a consequence, every node has acc...

  17. Synchronous Bilateral Adrenal Metastases from Papillary Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Kaan Gokcen

    2014-12-01

    Full Text Available We report a case of synchronous bilateral adrenal metastasis of renal cell carcinoma. The contralateral metastatic adrenal mass was treated by the laparoscopic transperitoneal approach. The renal mass and its huge ipsilateral metastatic adrenal gland were removed en bloc with open procedure. A 54-year-old man presented to our clinic with left-sid renal cell carcinoma synchronously bilateral adrenal metastases. The primary tumor was localized in the upper-mid pole of the kidney. The diagnosis was established preoperatively by computed tomography. The size of the contralateral adrenal mass was 65 x 45 mm, but the ipsilateral metastatic adrenal mass was huge (140 x 65 mm. After all analysis and other scannings for any metastasis, a contralateral lapararoscopic transperitoneal adrenalectomy and a left open nephroadrenalectomy were performed simultaneously. Synchronous bilateral adrenal metastases from primary renal cell carcinoma without another metastasis is very rare. The optimal surgical procedure should be selected according to the metastatic adrenal masses size and the patient%u2019s status.

  18. High-Q cavity-induced synchronization in oscillator arrays

    DEFF Research Database (Denmark)

    Filatrella, Giovanni; Pedersen, Niels Falsig; Wiesenfeld, Kurt

    2000-01-01

    A model for a large number of Josephson junctions coupled to a cavity is presented. The system displays synchronization behavior very similar to that reported in recent experiments [P. Barbara ct al., Phys. Rev. Lett. 82, 1963 (1999)]. The essential dynamical mechanism responsible for coherence...... should be generic in nonlinear oscillator systems where the interactions are mediated by a highly resonant cavity, in analogy with gas lasers....

  19. Robust synchronization of coupled circadian and cell cycle oscillators in single mammalian cells.

    Science.gov (United States)

    Bieler, Jonathan; Cannavo, Rosamaria; Gustafson, Kyle; Gobet, Cedric; Gatfield, David; Naef, Felix

    2014-07-15

    Circadian cycles and cell cycles are two fundamental periodic processes with a period in the range of 1 day. Consequently, coupling between such cycles can lead to synchronization. Here, we estimated the mutual interactions between the two oscillators by time-lapse imaging of single mammalian NIH3T3 fibroblasts during several days. The analysis of thousands of circadian cycles in dividing cells clearly indicated that both oscillators tick in a 1:1 mode-locked state, with cell divisions occurring tightly 5 h before the peak in circadian Rev-Erbα-YFP reporter expression. In principle, such synchrony may be caused by either unidirectional or bidirectional coupling. While gating of cell division by the circadian cycle has been most studied, our data combined with stochastic modeling unambiguously show that the reverse coupling is predominant in NIH3T3 cells. Moreover, temperature, genetic, and pharmacological perturbations showed that the two interacting cellular oscillators adopt a synchronized state that is highly robust over a wide range of parameters. These findings have implications for circadian function in proliferative tissues, including epidermis, immune cells, and cancer.

  20. Stochastic synchronization analysis of cultured human glial cells

    Science.gov (United States)

    Balazsi, Gabor; Cornell-Bell, Ann; Simonotto, Enrico; Neiman, Alexander; Moss, Frank

    2000-03-01

    The production of calcium waves is a property of a healthy astrocyte culture when exposed to the neurotransmitter kainate [Jung et al, J. Neurophys, 79, 1098 (1998)]. Healthy and epileptic tissues differ to a great extent in their dynamics: while a healthy cell culture shows much pattern formation, and wave propagation, the epileptic tissue shows spatially irregular flickering activity or global oscillation. Developing statistical tools to describe healthy versus epileptic tissue dynamics could be very important in order to study the effects of specific drugs, or to identify oscillation centers in the epileptic brain. We perform a statistical analysis in terms of phase synchronization. We show that hyper active epileptic astrocyte cultures are characterized by synchronization between different regions of the network taken from the uncus part of the brain.

  1. Cell cycle synchronization of canine ear fibroblasts for somatic cell nuclear transfer.

    Science.gov (United States)

    Koo, Ok Jae; Hossein, Mohammad Shamim; Hong, So Gun; Martinez-Conejero, Jose A; Lee, Byeong Chun

    2009-02-01

    Cycle synchronization of donor cells in the G0/G1 stage is a crucial step for successful somatic cell nuclear transfer. In the present report, we evaluated the effects of contact inhibition, serum starvation and the reagents - dimethyl sulphoxide (DMSO), roscovitine and cycloheximide (CHX) - on synchronization of canine fibroblasts at the G0/G1 stage. Ear fibroblast cells were collected from a beagle dog, placed into culture and used for analysis at passages three to eight. The population doubling time was 36.5 h. The proportion of G0/G1 cells was significantly increased by contact inhibition (77.1%) as compared with cycling cells (70.1%); however, extending the duration of culture did not induce further synchronization. After 24 h of serum starvation, cells were effectively synchronized at G0/G1 (77.1%). Although synchronization was further increased gradually after 24 h and even showed significant difference after 72 h (82.8%) of starvation, the proportion of dead cells also significantly increased after 24 h. The percentage of cells at the G0/G1 phase was increased (as compared with controls) after 72 h treatment with DMSO (76.1%) and after 48 h treatment with CHX (73.0%) or roscovitine (72.5%). However, the rate of cell death was increased after 24 and 72 h of treatment with DMSO and CHX, respectively. Thus, we recommend the use of roscovitine for cell cycle synchronization of canine ear fibroblasts as a preparatory step for SCNT.

  2. Cycle life characteristics of sealed silver-zinc cell with inorganic separator. [for synchronous orbit applications

    Science.gov (United States)

    Lear, J. W.; Imamura, M. S.

    1977-01-01

    Two batteries containing 18 cells have been cycling in a simulated synchronous (24-hour) orbit for over a year at 40% depth of discharge at 22 C. One battery is under individual cell monitoring and control and the other battery is controlled at the battery level. The battery with individual cell monitoring and protection has performed over 350 cycles with no sign of failure. The battery without individual cell protection failed at 270 cycles from failure to remain above the specified minimum discharge voltage. A significant conclusion is that the sealed Ag-Zn cells manufactured with the inorganic separator material have demonstrated their capability to cycle at a fairly high depth of discharge and are worthy of consideration in short life synchronous orbit applications.

  3. Synchronous Pulmonary Squamous Cell Carcinoma and Mantle Cell Lymphoma of the Lymph Node

    Directory of Open Access Journals (Sweden)

    Yu Sun

    2011-01-01

    Full Text Available Synchronous occurrence of pulmonary squamous cell carcinoma and malignant lymphoma of the lymph node is not reported in the literature. We report a case of pulmonary squamous cell carcinoma coexisting with a mantle cell lymphoma involving cervical and mediastinal lymph node. It is important to recognize this synchronous occurrence histopathologically and to be aware of the existence of “in situ” MCL.

  4. Ipsilateral synchronous renal pelvic transitional cell carcinoma, squamous cell carcinoma and adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    韩平; 魏强; 石明; 杨宇如

    2004-01-01

    @@ Reports of multiple synchronous primary renal neoplasms in the literature are rare. Although primary renal tumors of 2 distinctively dissimilar origins have been sporadically described,1-6 to our knowledge there have been no reported cases of triple primary renal neoplasms in the same kidney. Here we report a very rare case of ipsilateral synchronous renal pelvic transitional cell carcinoma, squamous cell carcinoma and adenocarcinoma with marked hydronephrosis and multiple stones in the same kidney.

  5. Synchronization of High-order Discrete-time Linear Complex Networks with Time-varying Delays

    Institute of Scientific and Technical Information of China (English)

    HaiLong Li; JianXiang Xi; YaoQing Cao; DuoSheng Wu

    2014-01-01

    Synchronization of high-order discrete-time complex networks with undirected topologies is studied and the impacts of time delays are investigated. Firstly, by the state decomposition, synchronization problems are transformed into asymptotic stability ones of multiple lower dimensional time-delayed subsystems. Then, linear matrix inequality ( LMI) criteria for synchronization are given, which can guarantee the scalability of complex networks since they only include three LMI constraints independent of the number of agents. Moreover, an explicit expression of the synchronization function is presented, which can describe the synchronization behavior of all agents in complex networks. Finally, a numerical example is given to demonstrate the theoretical results, where it is shown that if the gain matrices of synchronization protocols satisfy LMI criteria for synchronization, synchronization can be achieved.

  6. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Aalkjær, Christian; Matchkov, Vladimir V

    2008-01-01

    be entrained at the onset of vasomotion by the collective driving force from the synchronized oscillations in the membrane potential of the surrounding cells. Partial synchronization arises with an increase in the concentration of cyclic guanosine monophosphate, but in a heterogeneous cell population complete...

  7. Gastric cancer patients at high-risk of having synchronous cancer

    Institute of Scientific and Technical Information of China (English)

    Jun Ho Lee; Jae-Gahb Park; Jae-Moon Bae; Ja Seong Bae; Keun Won Ryu; Jong Seok Lee; Sook Ryun Park; Chan Gyoo Kim; Myoung Cheorl Kook; Il Ju Choi; Young Woo Kim

    2006-01-01

    AIM: To identify patients with a high-risk of having a synchronous cancer among gastric cancer patients.METHODS: We retrospectively analyzed the prospective gastric cancer database at the National Cancer Center,Korea from December 2000 to December 2004. The clinicopathological characteristics of patients with synchronous cancers and those of patients without synchronous cancers were compared. Multivariate analysis was performed to identify the risk factors for the presence of a synchronous cancer in gastric cancer patients.RESULTS: 111 of 3291 gastric cancer patients (3.4%)registered in the database had a synchronous cancer.Among these 111 patients, 109 had a single synchronous cancer and 2 patients had two synchronous cancers. The most common form of synchronous cancer was colorectal cancer (42 patients, 37.2%) followed by lung cancer (21 patients, 18.6%). Multivariate analyses revealed that elderly patients with differentiated early gastric cancer have a higher probability of a synchronous cancer.CONCLUSION: Synchronous cancers in gastric cancer patients are not infrequent. The physicians should try to find synchronous cancers in gastric cancer patients,especially in the elderly with a differentiated early gastric cancer.

  8. Design of High Performance Permanent-Magnet Synchronous Wind Generators

    Directory of Open Access Journals (Sweden)

    Chun-Yu Hsiao

    2014-11-01

    Full Text Available This paper is devoted to the analysis and design of high performance permanent-magnet synchronous wind generators (PSWGs. A systematic and sequential methodology for the design of PMSGs is proposed with a high performance wind generator as a design model. Aiming at high induced voltage, low harmonic distortion as well as high generator efficiency, optimal generator parameters such as pole-arc to pole-pitch ratio and stator-slot-shoes dimension, etc. are determined with the proposed technique using Maxwell 2-D, Matlab software and the Taguchi method. The proposed double three-phase and six-phase winding configurations, which consist of six windings in the stator, can provide evenly distributed current for versatile applications regarding the voltage and current demands for practical consideration. Specifically, windings are connected in series to increase the output voltage at low wind speed, and in parallel during high wind speed to generate electricity even when either one winding fails, thereby enhancing the reliability as well. A PMSG is designed and implemented based on the proposed method. When the simulation is performed with a 6 Ω load, the output power for the double three-phase winding and six-phase winding are correspondingly 10.64 and 11.13 kW. In addition, 24 Ω load experiments show that the efficiencies of double three-phase winding and six-phase winding are 96.56% and 98.54%, respectively, verifying the proposed high performance operation.

  9. Cell cycle synchronization reveals greater G2/M-phase accumulation of lung epithelial cells exposed to titanium dioxide nanoparticles.

    Science.gov (United States)

    Medina-Reyes, Estefany I; Bucio-López, Laura; Freyre-Fonseca, Verónica; Sánchez-Pérez, Yesennia; García-Cuéllar, Claudia M; Morales-Bárcenas, Rocío; Pedraza-Chaverri, José; Chirino, Yolanda I

    2015-03-01

    Titanium dioxide has been classified in the 2B group as a possible human carcinogen by the International Agency for Research on Cancer, and amid concerns of its exposure, cell cycle alterations are an important one. However, several studies show inconclusive effects, mainly because it is difficult to compare cell cycle effects caused by TiO2 nanoparticle (NP) exposure between different shapes and sizes of NP, cell culture types, and time of exposure. In addition, cell cycle is frequently analyzed without cell cycle synchronization, which may also mask some effects. We hypothesized that synchronization after TiO2 NP exposure could reveal dissimilar cell cycle progression when compared with unsynchronized cell population. To test our hypothesis, we exposed lung epithelial cells to 1 and 10 μg/cm(2) TiO2 NPs for 7 days and one population was synchronized by serum starvation and inhibition of ribonucleotide reductase using hydroxyurea. Another cell population was exposed to TiO2 NPs under the same experimental conditions, but after treatments, cell cycle was analyzed without synchronization. Our results showed that TiO2 NP-exposed cells without synchronization had no changes in cell cycle distribution; however, cell population synchronized after 1 and 10 μg/cm(2) TiO2 NP treatment showed a 1.5-fold and 1.66-fold increase, respectively, in proliferation. Synchronized cells also reveal a faster capability of TiO2 NP-exposed cells to increase cell population in the G2/M phase in the following 9 h after synchronization. We conclude that synchronization discloses a greater percentage of cells in the G2/M phase and higher proliferation than TiO2 NP-synchronized cells.

  10. Measure Synchronization of High-Cycle Islets in Coupled Hamiltonian Systems

    Institute of Scientific and Technical Information of China (English)

    CHEN Shao-Ying; WANG Guang-Rui; CHEN Shi-Gang

    2004-01-01

    @@ Measure synchronization is a new phenomenon found in coupled Hamiltonian systems recently and it is interesting to understand its properties comprehensively. We discuss the measure synchronization of a coupled pair of standard maps in high period quasi-period orbits, and the measure synchronization transition is associated with the transition of coupled systems from quasi-periodicity to chaos. This behaviour is very different from that found by Hampton and Zanette [Phys. Rev. Lett. 83 (1999) 2179].

  11. Serum starvation and thymidine double blocking achieved efficient cell cycle synchronization and altered the expression of p27, p53, bcl-2 in canine breast cancer cells.

    Science.gov (United States)

    Tong, Jinjin; Sun, Dongdong; Yang, Chao; Wang, Yingxue; Sun, Sichao; Li, Qing; Bao, Jun; Liu, Yun

    2016-04-01

    Cell synchronization is an approach to obtain cell populations of the same stage, which is a prerequisite to studying the regulation of cell cycle progression in vivo. Serum starvation and thymidine double blocking (TdR) are two important practices in studying cell cycle synchronization. However, their effects on canine cancer cells as well as the regulatory mechanisms by these two methods are poorly understood. In this study, we determined the optimum conditions of serum starvation and TdR and their effects on cell cycle synchronization. We further explored the involvement of PI3K/Akt signaling pathway in the cell cycle synchronization by investigating the expression of three key genes (p27, p53 and bcl-2). Serum starvation resulted in a reversible cell cycle arrest and synchronously progress through G0/G1. The highest percentage of CHMm cells (87.47%) in G0/G1 stage was obtained after 42 h incubation with 0.5% fetal bovine serum (FBS). TdR double blocking could arrest 98.9% of CHMm cells in G1/S phase (0 h of release), and could arrest 93.74% of CHMm cells in S phase after 4h of release. We also found that the p27, p53, bcl-2 genes were most highly expressed in G0/G1 phase. Our current work revealed that serum starvation and TdR methods could achieve sufficient synchronization of CHMm cells. Moreover, the expression of p27, p53 and bcl-2 genes was related to cyclical movements and apoptosis. Our results will provide a new insight into cell cycle regulation and reprogramming of canine cancer cells induced by serum starvation and TdR blocking.

  12. Quality of Experience for Large Ultra-High-Resolution Tiled Displays with Synchronization Mismatch

    Directory of Open Access Journals (Sweden)

    Deshpande Sachin

    2011-01-01

    Full Text Available This paper relates to quality of experience when viewing images, video, or other content on large ultra-high-resolution displays made from individual display tiles. We define experiments to measure vernier acuity caused by synchronization mismatch for moving images. The experiments are used to obtain synchronization mismatch acuity threshold as a function of object velocity and as a function of occlusion or gap width. Our main motivation for measuring the synchronization mismatch vernier acuity is its relevance in the application of tiled display systems, which create a single contiguous image using individual discrete panels arranged in a matrix with each panel utilizing a distributed synchronization algorithm to display parts of the overall image. We also propose a subjective assessment method for perception evaluation of synchronization mismatch for large ultra-high-resolution tiled displays. For this, we design a synchronization mismatch measurement test video set for various tile configurations for various interpanel synchronization mismatch values. The proposed method for synchronization mismatch perception can evaluate tiled displays with or without tile bezels. The results from this work can help during design of low-cost tiled display systems, which utilize distributed synchronization mechanisms for a contiguous or bezeled image display.

  13. Laparoscopic Nephrectomy with Adrenalectomy for Synchronous Adrenal Myelolipoma and Renal Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Kallappan Senthil

    2015-01-01

    Full Text Available Introduction. Adrenal myelolipomas are uncommon nonfunctioning tumors of the adrenal. Synchronous renal cell carcinomas with adrenal myelolipomas are very rare. We present the case report of adrenal myelolipoma with synchronous RCC managed laparoscopically. Case Report. A 60-year-old old gentleman presented with incidental right upper polar mass with right adrenal mass. Metastatic work-up was negative. Laparoscopic radical nephrectomy with adrenalectomy was done under general anesthesia. The biopsy report was right kidney clear cell adenocarcinoma (T1b with right adrenal myelolipoma. Conclusion. This is the first case report of laparoscopic adrenalectomy with nephrectomy for ipsilateral synchronous renal cell carcinoma with adrenal myelolipoma.

  14. Synchronous multifocal osteosarcoma with small cell histological variant: A double rarity

    Directory of Open Access Journals (Sweden)

    Sonia Gon

    2016-01-01

    Full Text Available Multifocal osteosarcoma (MFOS, osteosarcoma involving multiple sites, is a rare variant of osteosarcoma. When the lesions appear within 6 months of initial presentation of the tumor, it is known as synchronous MFOS. Synchronous MFOS has an incidence of 1%–3% only. Moreover, the histological variant of small cell osteosarcoma is even rarer. A case of 14-year-old male with synchronous MFOS of small cell type involving frontal and mandibular bone simultaneously is being reported here. It poses a dilemma to both the clinician and the pathologist to diagnose whether it represents multiple primary tumor or metastatic disease.

  15. Non-polypoidal, synchronous mantle- cell lymphoma of small intestine: a rare case

    Directory of Open Access Journals (Sweden)

    Sikalias Nikolaos

    2010-08-01

    Full Text Available Abstract Herein is reported the case of a mantle cell lymphoma (MCL with synchronous double intestinal location. A 74 - year old male presented with mild abdominal pain. CT scan imaging indicated invasion of lateral intestinal cavity by large mass formation. Exploratory laparotomy was performed and two solid extra-mural masses were isolated and excised. Histology revealed non- polypoid double synchronous lymphoma of mantle cell origin, an unusual presentation of the disease.

  16. Heterogeneity and weak coupling may explain the synchronization characteristics of cells in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Aalkjær, Christian; Matchkov, Vladimir

    2008-01-01

    Vascular smooth muscle cells (SMCs) exhibit different types of calcium dynamics. Static vascular tone is associated with unsynchronized calcium waves and the developed force depends on the number of recruited cells. Global calcium transients synchronized among a large number of cells cause rhythmic...... are enrolled into synchronized oscillation.Simulations of coupled SMCs show that the experimentally observed cellular recruitment, the presence of quiescent cells and the variation in oscillation frequency may arise if the cell population is phenotypically heterogeneous. In this case, quiescent cells can...

  17. Synchronization of cells with activator-inhibitor pathways through adaptive environment-mediated coupling.

    Science.gov (United States)

    Ghomsi, P Guemkam; Kakmeni, F M Moukam; Tchawoua, C; Kofane, T C

    2015-01-01

    In this paper, we report the synchronized dynamics of cells with activator-inhibitor pathways via an adaptive environment-mediated coupling scheme with feedbacks and control mechanisms. The adaptive character of the extracellular medium is modeled via its damping parameter as a physiological response aiming at annihilating the cellular differentiation existing between the chaotic biochemical pathways of the cells, in order to preserve homeostasis. We perform an investigation on the existence and stability of the synchronization manifold of the coupled system under the proposed coupling pattern. Both mathematical and computational tools suggest the accessibility of conducive prerequisites (conditions) for the emergence of a robust synchronous regime. The relevance of a phase-synchronized dynamics is appraised and several numerical indicators advocate for the prevalence of this fascinating phenomenon among the interacting cells in the phase space.

  18. Synchronization of cells with activator-inhibitor pathways through adaptive environment-mediated coupling

    Science.gov (United States)

    Ghomsi, P. Guemkam; Moukam Kakmeni, F. M.; Tchawoua, C.; Kofane, T. C.

    2015-11-01

    In this paper, we report the synchronized dynamics of cells with activator-inhibitor pathways via an adaptive environment-mediated coupling scheme with feedbacks and control mechanisms. The adaptive character of the extracellular medium is modeled via its damping parameter as a physiological response aiming at annihilating the cellular differentiation existing between the chaotic biochemical pathways of the cells, in order to preserve homeostasis. We perform an investigation on the existence and stability of the synchronization manifold of the coupled system under the proposed coupling pattern. Both mathematical and computational tools suggest the accessibility of conducive prerequisites (conditions) for the emergence of a robust synchronous regime. The relevance of a phase-synchronized dynamics is appraised and several numerical indicators advocate for the prevalence of this fascinating phenomenon among the interacting cells in the phase space.

  19. 12.5 Gbps 1:16 DEMUX IC with high speed synchronizing circuits

    Institute of Scientific and Technical Information of China (English)

    Zhou Lei; Wu Danyu; Chen Jianwu; Jin Zhi; Liu Xinyu

    2011-01-01

    A 12.5 Gbps 1∶16 demultiplexer(DEMUX)integrated circuit is presented for multi-channel high-speed data transmission.A novel high-speed synchronizing technique is proposed and integrated in this DEMUX chip.Compared with conventional synchronizing techniques,the proposed method largely simplifies the system configuration.The experimental result demonstrates that the proposed circuit is effective in two-channel synchronization under a clock frequency of 12.5 GHz.The circuit is realized using 1 μm GaAs heterojunction bipolar transistor technology with die area of 2.3 × 2.3 mm2.

  20. Mimosine As Well As Serum Starvation Can Be Used for Cell Cycle Synchronization of Sheep Granulosa Cells

    OpenAIRE

    2014-01-01

    This study was evaluated the effect of different synchronization protocols such as serum starvation for 1–3 days, confluency and chemical inhibitors on synchronization accuracy at G0/G1, apoptosis, and DNA synthesis in sheep granulosa cells. The cells were obtained from ovarian antral follicles of slaughtered sheep and used at first and fifth passages. Flow cytometry analysis showed that confluent cells, serum starvation for 24, 48, and 72 hours, and mimosine treatment significantly increase...

  1. High performance frame synchronization for continuous variable quantum key distribution systems.

    Science.gov (United States)

    Lin, Dakai; Huang, Peng; Huang, Duan; Wang, Chao; Peng, Jinye; Zeng, Guihua

    2015-08-24

    Considering a practical continuous variable quantum key distribution(CVQKD) system, synchronization is of significant importance as it is hardly possible to extract secret keys from unsynchronized strings. In this paper, we proposed a high performance frame synchronization method for CVQKD systems which is capable to operate under low signal-to-noise(SNR) ratios and is compatible with random phase shift induced by quantum channel. A practical implementation of this method with low complexity is presented and its performance is analysed. By adjusting the length of synchronization frame, this method can work well with large range of SNR values which paves the way for longer distance CVQKD.

  2. Synchronization of a coupled Hodgkin-Huxley neurons via high order sliding-mode feedback

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Lopez, R. [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana, Av. San Pablo No. 180, Reynosa-Tamaulipas, 02200 Azcapotzalco, Mexico, D.F. (Mexico)], E-mail: raguilar@correo.azc.uam.mx; Martinez-Guerra, R. [Departamento de Control Automatico, CINVESTAV-IPN, Apartado Postal 14-740, Mexico, D.F. C.P. 07360 (Mexico)], E-mail: rguerra@ctrl.cinvestav.mx

    2008-07-15

    This work deals with the synchronizations of two both coupled Hodgkin-Huxley (H-H) neurons, where the master neuron posses inner noise and the slave neuron is considered in a resting state, (without inner noise) and an exciting state (with inner noise). The synchronization procedure is done via a feedback control, considering a class of high order sliding-mode controller which provides chattering reduction and finite time synchronization convergence, with a satisfactory performance. Theoretical analysis is done in order to show the closed-loop stability of the proposed controller and the calculated finite time for convergence. The main results are illustrated via numerical experiments.

  3. Synchronization enhancement via an oscillatory bath in a network of self-excited cells

    Indian Academy of Sciences (India)

    B R Nana Nbendjo; H G Enjieu Kadji; Hilda A Cerdeira

    2015-02-01

    The possibility of using a dynamic environment to achieve and optimize phase synchronization in a network of self-excited cells with free-end boundary conditions is addressed in this paper. The dynamic environment is an oscillatory bath coupled linearly to a network of four cells. The boundaries of the stable solutions of the dynamical states as well as the ranges of coupling parameters leading to stability and instability of synchronization are determined. Numerical simulations are used to check the accuracy and to complement the result obtained from analytical treatment. The robustness of synchronization strategy is tested using a local and global injection of Gaussian white noise in the network. The control gain parameter of the bath coupling can modulate the occurrence of synchronization in the network without prior requirement of direct coupling among all the cells. The process of synchronization obtained through local injection is independent of the node at which noise is injected into the system. As compared to local injection, the global injection scheme increases the range of noise amplitude for which synchronization occurs in the network.

  4. Detection of silent cells, synchronization and modulatory activity in developing cellular networks.

    Science.gov (United States)

    Hjorth, Johannes J J; Dawitz, Julia; Kroon, Tim; Pires, Johny; Dassen, Valerie J; Berkhout, Janna A; Emperador Melero, Javier; Nadadhur, Aish G; Alevra, Mihai; Toonen, Ruud F; Heine, Vivi M; Mansvelder, Huibert D; Meredith, Rhiannon M

    2016-04-01

    Developing networks in the immature nervous system and in cellular cultures are characterized by waves of synchronous activity in restricted clusters of cells. Synchronized activity in immature networks is proposed to regulate many different developmental processes, from neuron growth and cell migration, to the refinement of synapses, topographic maps, and the mature composition of ion channels. These emergent activity patterns are not present in all cells simultaneously within the network and more immature "silent" cells, potentially correlated with the presence of silent synapses, are prominent in different networks during early developmental periods. Many current network analyses for detection of synchronous cellular activity utilize activity-based pixel correlations to identify cellular-based regions of interest (ROIs) and coincident cell activity. However, using activity-based correlations, these methods first underestimate or ignore the inactive silent cells within the developing network and second, are difficult to apply within cell-dense regions commonly found in developing brain networks. In addition, previous methods may ignore ROIs within a network that shows transient activity patterns comprising both inactive and active periods. We developed analysis software to semi-automatically detect cells within developing neuronal networks that were imaged using calcium-sensitive reporter dyes. Using an iterative threshold, modulation of activity was tracked within individual cells across the network. The distribution pattern of both inactive and active, including synchronous cells, could be determined based on distance measures to neighboring cells and according to different anatomical layers.

  5. A fixpoint semantics for "memory cells" in synchronous dataflows

    Directory of Open Access Journals (Sweden)

    Catalin Dima

    2008-01-01

    Full Text Available We study an iteration operation modeling the repeated behavior of syn-chronous dataflows in which all partial results are issued and also memorized for the next computation step. The definition is by means of a fixpoint equation. We prove some equational properties of iteration, comparing them to the ones of the Elgot iteration. We also prove a normal form theorem for dataflows and show that equality is decidable for canonical dataflows associated to freely generated algebraic theories.

  6. Nuclear transfer of synchronized African wild cat somatic cells into enucleated domestic cat oocytes

    Science.gov (United States)

    Gomez, M.C.; Jenkins, J.A.; Giraldo, A.; Harris, R.F.; King, A.; Dresser, B.L.; Pope, C.E.

    2003-01-01

    The African wild cat is one of the smallest wild cats and its future is threatened by hybridization with domestic cats. Nuclear transfer, a valuable tool for retaining genetic variability, offers the possibility of species continuation rather than extinction. The aim of this study was to investigate the ability of somatic cell nuclei of the African wild cat (AWC) to dedifferentiate within domestic cat (DSH) cytoplasts and to support early development after nuclear transplantation. In experiment 1, distributions of AWC and DSH fibroblasts in each cell-cycle phase were assessed by flow cytometry using cells cultured to confluency and disaggregated with pronase, trypsin, or mechanical separation. Trypsin (89.0%) and pronase (93.0%) yielded higher proportions of AWC nuclei in the G0/G1 phase than mechanical separation (82.0%). In contrast, mechanical separation yielded higher percentages of DSH nuclei in the G0/G1 phase (86.6%) than pronase (79.7%) or trypsin (74.2%) treatments. In both species, pronase induced less DNA damage than trypsin. In experiment 2, the effects of serum starvation, culture to confluency, and exposure to roscovitine on the distribution of AWC and DSH fibroblasts in various phases of the cell cycle were determined. Flow cytometry analyses revealed that the dynamics of the cell cycle varied as culture conditions were modified. Specifically, a higher percentage of AWC and DSH nuclei were in the G0/G1 phase after cells were serum starved (83% vs. 96%) than were present in cycling cells (50% vs. 64%), after contact inhibition (61% vs. 88%), or after roscovitine (56% vs. 84%) treatment, respectively. In experiment 3, we evaluated the effects of cell synchronization and oocyte maturation (in vivo vs. in vitro) on the reconstruction and development of AWC-DSH- and DSH-DSH-cloned embryos. The method of cell synchronization did not affect the fusion and cleavage rate because only a slightly higher percentage of fused couplets cleaved when donor nuclei

  7. Completion of cell division is associated with maximum telomerase activity in naturally synchronized cultures of the green alga Desmodesmus quadricauda.

    Science.gov (United States)

    Ševčíková, Tereza; Bišová, Kateřina; Fojtová, Miloslava; Lukešová, Alena; Hrčková, Kristýna; Sýkorová, Eva

    2013-03-18

    Telomerase maintains the ends of eukaryotic chromosomes, and its activity is an important parameter correlating with the proliferative capacity of cells. We have investigated cell cycle-specific changes in telomerase activity using cultures of Desmodesmus quadricauda, a model alga naturally synchronized by light/dark entrainment. A quantitative telomerase assay revealed high activity in algal cultures, with slight changes during the light period. Significantly increased telomerase activity was observed at the end of the dark phase, when cell division was complete. In contrast to other models, a natural separation between nuclear and cellular division typical for the cell cycle in D. quadricauda made this observation possible.

  8. The Paralleling of High Power High Frequency Amplifier Based on Synchronous and Asynchronous Control

    Institute of Scientific and Technical Information of China (English)

    程荣仓; 刘正之

    2004-01-01

    The vertical position of plasma in the HT-7U Tokamak is inherently unstable. In order to realize active stabilization, the response rate of the high-power high-frequency amplifier feeding the active control coils must be fast enough. This paper analyzes the paralleling scheme of the power amplifier through two kinds of control mode. One is the synchronous control; the other is the asynchronous control. Via the comparison of the two kinds of control mode, both of their characteristics are given in the text. At last, the analyzed result is verified by a small power experiment.

  9. Synchronization of grid-connected renewable energy sources under highly distorted voltages and unbalanced grid faults

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Blaabjerg, Frede

    2013-01-01

    renewable energy systems. Therefore, the performance of the new PLL can increase the quality of the injected power under abnormal conditions and in addition enable the renewable energy systems to provide the appropriate support to the grid under balanced and unbalanced grid faults.......Renewable energy sources require accurate and appropriate performance not only under normal grid operation but also under abnormal and faulty grid conditions according to the modern grid codes. This paper proposes a novel phase-locked loop algorithm (MSHDC-PLL), which can enable the fast...... and dynamic synchronization of the interconnected renewable energy system under unbalanced grid faults and under highly harmonic distorted voltage. The outstanding performance of the suggested PLL is achieved by implementing an innovative multi-sequence/harmonic decoupling cell in order to dynamically cancel...

  10. Cell-cycle research with synchronous cultures: an evaluation

    Science.gov (United States)

    Helmstetter, C. E.; Thornton, M.; Grover, N. B.

    2001-01-01

    The baby-machine system, which produces new-born Escherichia coli cells from cultures immobilized on a membrane, was developed many years ago in an attempt to attain optimal synchrony with minimal disturbance of steady-state growth. In the present article, we put forward a model to describe the behaviour of cells produced by this method, and provide quantitative evaluation of the parameters involved, at each of four different growth rates. Considering the high level of selection achievable with this technique and the natural dispersion in interdivision times, we believe that the output of the baby machine is probably close to optimal in terms of both quality and persistence of synchrony. We show that considerable information on events in the cell cycle can be obtained from populations with age distributions very much broader than those achieved with the baby machine and differing only modestly from steady state. The data presented here, together with the long and fruitful history of findings employing the baby-machine technique, suggest that minimisation of stress on cells is the single most important factor for successful cell-cycle analysis.

  11. Synchronous advanced gastric adenocarcinoma and advanced esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Fernando Augusto Mardiros Herbella

    2002-01-01

    Full Text Available CONTEXT: Synchronous associations of esophageal and gastric cancers are not a common finding, especially with differing histological types and both tumors in advanced forms. A case with such an association is presented, in which an unusual therapy was proposed: palliative gastrectomy and esophageal intubation. CASE REPORT: A 75-year-old white man was referred to our service complaining of malaise and weight loss for one year and dysphagia and vomiting for 2 months. The patient had sought out medical consultation as a result of the latter two complaints.

  12. Synchronization of S phase in Schizosaccharomyces pombe cells by transient exposure to M-factor pheromone

    DEFF Research Database (Denmark)

    Nielsen, Olaf

    2016-01-01

    A well-characterized S phase, a unicellular lifestyle, and a plethora of mutations in key components of DNA metabolism make fission yeast a particularly attractive system in which to study DNA replication. However, synchronization of passage through a normal S phase has proved challenging. This p....... This protocol describes how combining nitrogen starvation with M-factor mating pheromone treatment presents a highly effective method for synchronizing passage through an ostensibly normal S phase....

  13. System and method to allow a synchronous motor to successfully synchronize with loads that have high inertia and/or high torque

    Energy Technology Data Exchange (ETDEWEB)

    Melfi, Michael J.

    2015-10-20

    A mechanical soft-start type coupling is used as an interface between a line start, synchronous motor and a heavy load to enable the synchronous motor to bring the heavy load up to or near synchronous speed. The soft-start coupling effectively isolates the synchronous motor from the load for enough time to enable the synchronous motor to come up to full speed. The soft-start coupling then brings the load up to or near synchronous speed.

  14. Employment of synchronized cells and flow microfluorometry in investigations on the JB-1 ascites tumour chalones.

    Science.gov (United States)

    Bichel, P; Barfod, N M; Jakobsen, A

    1975-11-01

    In most experimental ascites tumours the growth rate decreases with increasing age and cell number. This decrease is caused by a prolongation of the cell cycle and an increasing accumulation of non-cycling cells in resting (or quiescent) G1 and G2 compartments. In cell-free ascitic fluid from the JB-1 ascites tumour in the plateau phase of growth lowmolecular-weight substances have been found which reversibly and specifically arrest JB-1 cells in G1 and G2. The present paper describes an in-vitro model for testing the effect of the humoral growth inhibitors contained in the ascitic fluid. The test system is based on synchronized JB-1 cells analysed by flow-through cytofluorometry. Addition to the synchronous cells of a ultrafiltrate (less than 50000 Daltons) of the JB-1 ascitic fluid was found to induce a complete, but temporary arrest of the cells at the G1-S border.

  15. Sub-synchronous resonance damping using high penetration PV plant

    Science.gov (United States)

    Khayyatzadeh, M.; Kazemzadeh, R.

    2017-02-01

    The growing need to the clean and renewable energy has led to the fast development of transmission voltage-level photovoltaic (PV) plants all over the world. These large scale PV plants are going to be connected to power systems and one of the important subjects that should be investigated is the impact of these plants on the power system stability. Can large scale PV plants help to damp sub-synchronous resonance (SSR) and how? In this paper, this capability of a large scale PV plant is investigated. The IEEE Second Benchmark Model aggregated with a PV plant is utilized as the case study. A Wide Area Measurement System (WAMS) based conventional damping controller is designed and added to the main control loop of PV plant in order to damp the SSR and also investigation of the destructive effect of time delay in remote feedback signal. A new optimization algorithm called teaching-learning-based-optimization (TLBO) algorithm has been used for managing the optimization problems. Fast Furrier Transformer (FFT) analysis and also transient simulations of detailed nonlinear system are considered to investigate the performance of the controller. Robustness of the proposed system has been analyzed by facing the system with disturbances leading to significant changes in generator and power system operating point, fault duration time and PV plant generated power. All the simulations are carried out in MATLAB/SIMULINK environment.

  16. Determination of the High Frequency Inductance Profile of Surface Mounted Permanent Magnet Synchronous Motors

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

    2008-01-01

    Accurate knowledge of the high frequency inductance profile plays an important role in many designs of sensorless controllers for Surface inductance. A special algorithm is used to decouple the cross-coupling effects between the d-axis and the q-axis, which allows Mounted Permanent Magnet (SMPM......) synchronous motors. This paper presents an AC+DC measurement method for determination of the d-axis and q-axis high frequency inductance profiles of SMPM synchronous motors. This method uses DC currents to set a desired magnetic working point on the motor laminations, and then superimpose balanced small AC...

  17. Effective Suppression of Pathological Synchronization in Cortical Networks by Highly Heterogeneous Distribution of Inhibitory Connections

    Science.gov (United States)

    Kada, Hisashi; Teramae, Jun-Nosuke; Tokuda, Isao T.

    2016-01-01

    Even without external random input, cortical networks in vivo sustain asynchronous irregular firing with low firing rate. In addition to detailed balance between excitatory and inhibitory activities, recent theoretical studies have revealed that another feature commonly observed in cortical networks, i.e., long-tailed distribution of excitatory synapses implying coexistence of many weak and a few extremely strong excitatory synapses, plays an essential role in realizing the self-sustained activity in recurrent networks of biologically plausible spiking neurons. The previous studies, however, have not considered highly non-random features of the synaptic connectivity, namely, bidirectional connections between cortical neurons are more common than expected by chance and strengths of synapses are positively correlated between pre- and postsynaptic neurons. The positive correlation of synaptic connections may destabilize asynchronous activity of networks with the long-tailed synaptic distribution and induce pathological synchronized firing among neurons. It remains unclear how the cortical network avoids such pathological synchronization. Here, we demonstrate that introduction of the correlated connections indeed gives rise to synchronized firings in a cortical network model with the long-tailed distribution. By using a simplified feed-forward network model of spiking neurons, we clarify the underlying mechanism of the synchronization. We then show that the synchronization can be efficiently suppressed by highly heterogeneous distribution, typically a lognormal distribution, of inhibitory-to-excitatory connection strengths in a recurrent network model of cortical neurons. PMID:27803659

  18. Pterins in human hair follicle cells and in the synchronized murine hair cycle.

    Science.gov (United States)

    Schallreuter, K U; Beazley, W D; Hibberts, N A; Tobin, D J; Paus, R; Wood, J M

    1998-10-01

    Human dermal papilla cells (HDPC) express mRNA for the key enzymes for de novo synthesis/recycling and regulation of the pterin (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (6BH4). HDPC had significantly higher enzyme activities and 6BH4 levels in a comparative study with dermal fibroblasts, epidermal melanocytes, and keratinocytes under in vitro conditions. In addition, a significantly more rapid uptake of 14C-L-phenylalanine was demonstrated in HDPC compared with fibroblasts, whereas the differences in turnover to L-tyrosine were insignificant, suggesting a pooling of L-phenylalanine in HDPC. These results suggested that HDPC driven 6BH4 synthesis could be of major functional importance in the hair cycle. In order to follow this hypothesis in vivo, expression of enzyme activities and levels of the produced cofactor during the synchronized hair cycle were determined employing the murine model C57BL/6. These data revealed a significantly increased de novo synthesis for 6BH4 via GTP-cyclohydrolase I concomitant with high levels of 6BH4, and the induction of phenylalanine hydroxylase activities during the telogen/early anagen stage (days 0-1). Pterin levels and enzyme activities fall on day 3 and plateau during the rest of the entire cycle. In addition, thioredoxin reductase and glutathione reductase activities were measured, where the latter enzyme remained constant but thioredoxin reductase activities showed a biphasic behavior. The first peak coincided with the induction of 6BH4 de novo synthesis at the beginning of the hair cycle. The second peak was observed at mid-anagen, when melanogenesis takes place. Taken together, our results show the presence of autocrine pterin synthesis/recycling in human hair follicle cells under in vitro conditions, and a possible role for 6BH4 in the synchronized murine hair cycle.

  19. Discrete Coupling and Synchronization in the Insulin Release in the Mathematical Model of the β Cells

    Directory of Open Access Journals (Sweden)

    L. J. Ontañón-García

    2013-01-01

    Full Text Available The synchronization phenomenon that occurs in the Langerhans islets among pancreatic β cells is an interesting topic because these cells are responsible for the release of insulin in the blood stream. The aim of this work is to generate in-phase bursting electrical activity (BEA in β cells with different behaviors such as active, inactive, and continuous spiking cells based on mathematical models using a discrete time coupling. The approach considers two steps, the former is a mechanism on how to force β cells to switch from silent phase to active, the latter is based on how to deal with in phase synchronization between active β cells. The coupling signal is triggered in discrete events caused by the crossing of a threshold of an active β cell which is given or defined by a Poincaré plane. The coupling on the inactive cells is applied to the state in which are the concentrations of agents which regulate the BEA. Based on numerical simulations, synchronization in the insulin release is obtained from β cells with different behaviors.

  20. Cell type-specific synaptic dynamics of synchronized bursting in the juvenile CA3 rat hippocampus.

    Science.gov (United States)

    Aradi, Ildiko; Maccaferri, Gianmaria

    2004-10-27

    Spontaneous synchronous bursting of the CA3 hippocampus in vitro is a widely studied model of physiological and pathological network synchronization. The role of inhibitory conductances during network bursting is not understood in detail, despite the fact that several antiepileptic drugs target GABA(A) receptors. Here, we show that the first manifestation of a burst event is a cell type-specific flurry of GABA(A) receptor-mediated inhibitory input to pyramidal cells, but not to stratum oriens horizontal interneurons. Moreover, GABA(A) receptor-mediated synaptic input is proportionally smaller in these interneurons compared with pyramidal cells. Computational models and dynamic-clamp studies using experimentally derived conductance waveforms indicate that both these factors modulate spike timing during synchronized activity. In particular, the different kinetics and the larger strength of GABAergic input to pyramidal cells defer action potential initiation and contribute to the observed delay of firing, so that the interneuronal activity leads the burst cycle. In contrast, excitatory inputs to both neuronal populations during a burst are kinetically similar, as required to maintain synchronicity. We also show that the natural pattern of activation of inhibitory and excitatory conductances during a synchronized burst cycle is different within the same neuronal population. In particular, GABA(A) receptor-mediated currents activate earlier and outlast the excitatory components driving the bursts. Thus, cell type-specific balance and timing of GABA(A) receptor-mediated input are critical to set the appropriate spike timing in pyramidal cells and interneurons and coordinate additional neurotransmitter release modulating burst strength and network frequency.

  1. High-frequency stimulation-induced peptide release synchronizes arcuate kisspeptin neurons and excites GnRH neurons

    Science.gov (United States)

    Qiu, Jian; Nestor, Casey C; Zhang, Chunguang; Padilla, Stephanie L; Palmiter, Richard D

    2016-01-01

    Kisspeptin (Kiss1) and neurokinin B (NKB) neurocircuits are essential for pubertal development and fertility. Kisspeptin neurons in the hypothalamic arcuate nucleus (Kiss1ARH) co-express Kiss1, NKB, dynorphin and glutamate and are postulated to provide an episodic, excitatory drive to gonadotropin-releasing hormone 1 (GnRH) neurons, the synaptic mechanisms of which are unknown. We characterized the cellular basis for synchronized Kiss1ARH neuronal activity using optogenetics, whole-cell electrophysiology, molecular pharmacology and single cell RT-PCR in mice. High-frequency photostimulation of Kiss1ARH neurons evoked local release of excitatory (NKB) and inhibitory (dynorphin) neuropeptides, which were found to synchronize the Kiss1ARH neuronal firing. The light-evoked synchronous activity caused robust excitation of GnRH neurons by a synaptic mechanism that also involved glutamatergic input to preoptic Kiss1 neurons from Kiss1ARH neurons. We propose that Kiss1ARH neurons play a dual role of driving episodic secretion of GnRH through the differential release of peptide and amino acid neurotransmitters to coordinate reproductive function. DOI: http://dx.doi.org/10.7554/eLife.16246.001 PMID:27549338

  2. Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices.

    Science.gov (United States)

    Hamidi, S; Lévesque, M; Avoli, M

    2014-12-05

    We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.

  3. Topology Optimization of a High-Temperature Superconducting Field Winding of a Synchronous Machine

    DEFF Research Database (Denmark)

    Pozzi, Matias; Mijatovic, Nenad; Jensen, Bogi Bech

    2013-01-01

    genetic algorithm with local optimization search based on on/off sensitivity analysis. The results show an optimal HTS coil distribution, achieving compact designs with a maximum of approximately 22% of the available space for the field winding occupied with HTS tape. In addition, this paper describes......This paper presents topology optimization (TO) of the high-temperature superconductor (HTS) field winding of an HTS synchronous machine. The TO problem is defined in order to find the minimum HTS material usage for a given HTS synchronous machine design. Optimization is performed using a modified...

  4. Synchronous motor with soft start element formed between the motor rotor and motor output shaft to successfully synchronize loads that have high inertia and/or high torque

    Energy Technology Data Exchange (ETDEWEB)

    Umans, Stephen D; Nisley, Donald L; Melfi, Michael J

    2014-10-28

    A line-start synchronous motor has a housing, a rotor shaft, and an output shaft. A soft-start coupling portion is operatively coupled to the output shaft and the rotor shaft. The soft-start coupling portion is configurable to enable the synchronous motor to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling. The synchronous motor is sufficiently rated to obtain synchronous operation and to drive, at least near synchronous speed during normal steady state operation of the motor, a load having characteristics sufficient to prevent obtaining normal synchronous operation of the motor when the motor is operatively connected to the load in the absence of the soft-start coupling.

  5. Synchronized Firings in Retinal Ganglion Cells in Response to Natural Stimulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ying-Ying; XIAO Lei; LIU Wen-Zhong; GONG Hai-Qing; LIANG Pei-Ji

    2011-01-01

    The response of synchronously firing groups of population retinal ganglion cells (RGCs) to natural movies (NMs)and pseudo-random white-noise checker-board flickering (CB, as control) are investigated using an informationtheoretic algorithm.The main results are: (1) the population RGCs tend to fire in synchrony far more frequently than expected by chance during both NM and CB stimulation; (2) more synchronous groups could be formed and each group contains more neurons under NM than CB stimulation; (3) the individual neurons also participate in more groups and have more distinct partners in NM than CB stimulation.All these results suggest that the synchronized firings in RGCs are more extensive and diverse, which may account for more effective information processing in representing the natural visual environment.%@@ The response of synchronously firing groups of population retinal ganglion cells (RGCs) to natural movies (NMs) and pseudo-random white-noise checker-board flickering (CB, as control) are investigated using an information-theoretic algorithm.The main results are: (1) the population RGCs tend to fire in synchrony far more frequently than expected by chance during both NM and CB stimulation; (2) more synchronous groups could be formed and each group contains more neurons under NM than CB stimulation; (3) the individual neurons also participate in more groups and have more distinct partners in NM than CB stimulation.All these results suggest that the synchronized firings in RGCs are more extensive and diverse, which may account for more effective information processing in representing the natural visual environment.

  6. Replication of the resident Marek's Disease virus genome in synchronized nonproducer MKT-1 cells.

    Science.gov (United States)

    Lau, R Y; Nonoyama, M

    1980-02-01

    MKT-1, a virus nonproducer lymphoblastoid cell line established from a Marek's disease tumor, was synchronized by double thymidine block to determine the sequence of events in the synthesis of cellular and latent marek's disease virus DNA. Cellular DNA synthesis was measured by incorporation of [3H]thymidine, whereas viral DNA synthesis was determined by DNA-DNA reassociation kinetics. The results of these studies indicate that the resident Marek's disease viral DNA in MKT-1 cells replicates during the early S phase of the cell cycle, before the onset of active cellular DNA synthesis. This observation is similar to that seen in the replication of resident Epstein-Barr virus DNA in synchronized Raji cells.

  7. Design and Modeling of High Performance Permanent Magnet Synchronous Machines

    NARCIS (Netherlands)

    Van der Geest, M.

    2015-01-01

    The electrification of transportation, and especially aerospace transportation, increases the demand for high performance electrical machines. Those machines often need to be fault-tolerant, cheap, highly efficient, light and small, and interface well with the inverter. In addition, the development

  8. Synchronous, primary, diffuse, large B-cell lymphomas involving the ethmoid sinus and epiglottis: a rare clinical entity.

    Science.gov (United States)

    Yoon, Young-Ho; Park, Won-Young; Choi, Young-Jin; Cho, Kyu-Sup

    2013-03-01

    Non-Hodgkin's lymphoma (NHL) affecting the ethmoid sinus and epiglottis is uncommon. Furthermore, synchronous NHLs involving the ethmoid sinus and epiglottis are extremely rare and have not been reported previously. This article reports synchronous, primary, diffuse, large B-cell lymphoma (DLBCL) arising in the ethmoid sinus and epiglottis, which was successfully treated by immunochemotherapy. A careful examination of the head and neck is necessary to determine the existence of multiple synchronous primary tumors, because primary synchronous occurrence of DLBCL in the head and neck is unusual and can impact the prognosis adversely.

  9. Noise-induced synchronous stochastic oscillations in small scale cultured heart-cell networks

    Institute of Scientific and Technical Information of China (English)

    Yuan Lan; Liu Zhi-Qiang; Zhang Hui-Min; Ding Xue-Li; Yang Ming-Hao; Gu Hua-Guang; Ren Wei

    2011-01-01

    This paper reports that the synchronous integer multiple oscillations of heart-cell networks or clusters are observed in the biology experiment. The behaviour of the integer multiple rhythm is a transition between super- and sub-threshold oscillations, the stochastic mechanism of the transition is identified. The similar synchronized oscillations are theoretically reproduced in the stochastic network composed of heterogeneous cells whose behaviours are chosen as excitable or oscillatory states near a Hopf bifurcation point. The parameter regions of coupling strength and noise density that the complex oscillatory rhythms can be simulated are identified. The results show that the rhythm results from a simple stochastic alternating process between super- and sub-threshold oscillations. Studies on single heart cells forming these clusters reveal excitable or oscillatory state nearby a Hopf bifurcation point underpinning the stochastic alternation. In discussion, the results are related to some abnormal heartbeat rhythms such as the sinus arrest.

  10. Doc2b synchronizes secretion from chromaffin cells by stimulating fast and inhibiting sustained release

    DEFF Research Database (Denmark)

    da Silva Pinheiro, Paulo César; de Wit, Heidi; Walter, Alexander M;

    2013-01-01

    is still high. We conclude that Doc2b acts to inhibit vesicle priming during prolonged calcium elevations, thus protecting unprimed vesicles from fusing prematurely, and redirecting them to refill the readily releasable pool after relaxation of the calcium signal. In sum, Doc2b favors fast, synchronized...

  11. New Power Estimation Methods for Highly Overloaded Synchronous CDMA Systems

    CERN Document Server

    Nashtaali, Damoun; Pad, Pedram; Moghadasi, Seyed Reza; Marvasti, Farokh

    2011-01-01

    In CDMA systems, the received user powers vary due to moving distance of users. Thus, the CDMA receivers consist of two stages. The first stage is the power estimator and the second one is a Multi-User Detector (MUD). Conventional methods for estimating the user powers are suitable for underor fully-loaded cases (when the number of users is less than or equal to the spreading gain). These methods fail to work for overloaded CDMA systems because of high interference among the users. Since the bandwidth is becoming more and more valuable, it is worth considering overloaded CDMA systems. In this paper, an optimum user power estimation for over-loaded CDMA systems with Gaussian inputs is proposed. We also introduce a suboptimum method with lower complexity whose performance is very close to the optimum one. We shall show that the proposed methods work for highly over-loaded systems (up to m(m + 1) =2 users for a system with only m chips). The performance of the proposed methods is demonstrated by simulations. In ...

  12. Multi-application inter-tile synchronization on ultra-high-resolution display walls

    KAUST Repository

    Nam, Sungwon

    2010-01-01

    Ultra-high-resolution tiled-display walls are typically driven by a cluster of computers. Each computer may drive one or more displays. Synchronization between the computers is necessary to ensure that animated imagery displayed on the wall appears seamless. Most tiled-display middleware systems are designed around the assumption that only a single application instance is running in the tiled display at a time. Therefore synchronization can be achieved with a simple solution such as a networked barrier. When a tiled display has to support multiple applications at the same time, however, the simple networked barrier approach does not scale. In this paper we propose and experimentally validate two synchronization algorithms to achieve low-latency, intertile synchronization for multiple applications with independently varying frame rates. The two-phase algorithm is more generally applicable to various highresolution tiled display systems. The one-phase algorithm provides superior results but requires support for the Network Time Protocol and is more CPU-intensive. Copyright 2010 ACM.

  13. Morphological and functional features of synchronous swimming sportswomen of high qualification

    Directory of Open Access Journals (Sweden)

    Rovnaya O.A.

    2014-03-01

    Full Text Available Purpose : the studying of morphological and functional features of synchronous swimming sportswomen of high qualification, establishing of the interrelation between anthropometrical characteristics and functional characteristics of the external respiration system. Material: the research involved 12 sportswomen aged 17-18 years. Results : it is shown exceeding physiometric indicators (vital capacity of lungs by 64%, carpal dynamometry 21-22% in synchronous swimming sportswomen have been compared to the standards of physical development. External breathing parameters illustrated adaptation of the organism to the specific loads: an increase in tidal volume by 40%, elongation of the duration of the expiration by 62.5%. A correlation between vital capacity of lungs and inspiratory duration (r = 0,47, with the frequency of breathing and duration of the inspiration (r = -0,83 and duration of the expiration (r = -0,93, is showing an increase in the functional reserves. Conclusions : have been found that morphological indicators of synchronous swimming sportswomen did not differ from the standards and indicators for physiometric and functional indices of the external respiratory system considerably exceed the same-age girls' indicators characterized the range of functional reserves and the resulting correlations reflected the direction of the adaptation process in specific environments of synchronous swimming.

  14. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Science.gov (United States)

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN. PMID:25663835

  15. Traffic Signal Synchronization in the Saturated High-Density Grid Road Network

    Directory of Open Access Journals (Sweden)

    Xiaojian Hu

    2015-01-01

    Full Text Available Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN. Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

  16. Traffic signal synchronization in the saturated high-density grid road network.

    Science.gov (United States)

    Hu, Xiaojian; Lu, Jian; Wang, Wei; Zhirui, Ye

    2015-01-01

    Most existing traffic signal synchronization strategies do not perform well in the saturated high-density grid road network (HGRN). Traffic congestion often occurs in the saturated HGRN, and the mobility of the network is difficult to restore. In order to alleviate traffic congestion and to improve traffic efficiency in the network, the study proposes a regional traffic signal synchronization strategy, named the long green and long red (LGLR) traffic signal synchronization strategy. The essence of the strategy is to control the formation and dissipation of queues and to maximize the efficiency of traffic flows at signalized intersections in the saturated HGRN. With this strategy, the same signal control timing plan is used at all signalized intersections in the HGRN, and the straight phase of the control timing plan has a long green time and a long red time. Therefore, continuous traffic flows can be maintained when vehicles travel, and traffic congestion can be alleviated when vehicles stop. Using the strategy, the LGLR traffic signal synchronization model is developed, with the objective of minimizing the number of stops. Finally, the simulation is executed to analyze the performance of the model by comparing it to other models, and the superiority of the LGLR model is evident in terms of delay, number of stops, queue length, and overall performance in the saturated HGRN.

  17. Surgical Treatment for Non-small Cell Lung Cancer Patients with Synchronous Solitary Brain Metastasis

    Directory of Open Access Journals (Sweden)

    Hao BAI

    2013-12-01

    Full Text Available Background and objective Brain metastases are common in non-small cell lung cancer. Usual treatments include radiotherapy and chemotherapy. However, these methods result in poor patient prognosis. The aim of this study is to assess the effectiveness of surgical resection in the multimodality management of non-small cell lung cancer patients with synchronous solitary brain metastasis. Methods The clinical data of 46 non-small cell lung cancer patients with synchronous solitary brain metastasis were retrospectively reviewed. All patients underwent surgical resection of primary lung tumor, followed by whole brain radiotherapy and chemotherapy. In addition, 13 out of the 46 patients underwent resection of brain metastasis, whereas the remaining 33 patients received stereotactic radiosurgery. Results The median survival time of the enrolled patients was 16.8 months. The 1-, 2-, and 3-year survival rates were 76.1%, 20.9%, and 4.7%, respectively. The median survival times of the patients with brain metastasis resection or stereotactic radiosurgery were 18.3 and 15.8 months, respectively (P=0.091,2. Conclusion Surgical resection of primary lung tumor and brain metastasis may improve prognosis of non-small cell lung cancer patients with synchronous solitary brain metastasis. However, the survival benefit of surgical resection over brain metastasis resection or stereotactic radiosurgery is uncertain.

  18. Membrane potential hyperpolarization in Mammalian cardiac cells by synchronization modulation of Na/K pumps.

    Science.gov (United States)

    Chen, Wei; Dando, Robin

    2008-02-01

    In previously reported work, we developed a new technique, synchronization modulation, to electrically activate Na/K pump molecules. The fundamental mechanism involved in this technique is a dynamic entrainment procedure of the pump molecules, carried out in a stepwise pattern. The entrainment procedure consists of two steps: synchronization and modulation. We theoretically predicted that the pump functions can be activated exponentially as a function of the membrane potential. We have experimentally demonstrated synchronization of the Na/K pump molecules and acceleration of their pumping rates by many fold through use of voltage-clamp techniques, directly monitoring the pump currents. We further applied this technique to intact skeletal muscle fibers from amphibians and found significant effects on the membrane resting potential. Here, we extend our study to intact mammalian cardiomyocytes. We employed a noninvasive confocal microscopic fluorescent imaging technique to monitor electric field-induced changes in ionic concentration gradient and membrane resting potential. Our results further confirm that the well-designed synchronization modulation electric field can effectively accelerate the Na/K pumping rate, increasing the ionic concentration gradient across the cell membrane and hyperpolarizing the membrane resting potential.

  19. On-chip constructive cell-Network study (I: Contribution of cardiac fibroblasts to cardiomyocyte beating synchronization and community effect

    Directory of Open Access Journals (Sweden)

    Yasuda Kenji

    2011-05-01

    Full Text Available Abstract Backgrounds To clarify the role of cardiac fibroblasts in beating synchronization, we have made simple lined-up cardiomyocyte-fibroblast network model in an on-chip single-cell-based cultivation system. Results The synchronization phenomenon of two cardiomyocyte networks connected by fibroblasts showed (1 propagation velocity of electrophysiological signals decreased a magnitude depending on the increasing number of fibroblasts, not the lengths of fibroblasts; (2 fluctuation of interbeat intervals of the synchronized two cardiomyocyte network connected by fibroblasts did not always decreased, and was opposite from homogeneous cardiomyocyte networks; and (3 the synchronized cardiomyocytes connected by fibroblasts sometimes loses their synchronized condition and recovered to synchronized condition, in which the length of asynchronized period was shorter less than 30 beats and was independent to their cultivation time, whereas the length of synchronized period increased according to cultivation time. Conclusions The results indicated that fibroblasts can connect cardiomyocytes electrically but do not significantly enhance and contribute to beating interval stability and synchronization. This might also mean that an increase in the number of fibroblasts in heart tissue reduces the cardiomyocyte 'community effect', which enhances synchronization and stability of their beating rhythms.

  20. High-resolution microwave-photonic applications via precise synchronization between RF and mode-locked laser pulses (Conference Presentation)

    Science.gov (United States)

    Shi, Kebin; Lu, Xing; Lv, Zhiqiang

    2016-10-01

    Precise synchronization between radio frequency and mode-locked laser pulses provides a high resolution capability for detecting either time jitter in laser pulse train or phase noise in radio frequency. In this talk, we will present our recent progresses on radio frequency dissemination and fiber optical sensing based on sub-femtosecond level synchronization between radio frequency and mode-locked pulse train.

  1. Impact of Loss Synchronization on Reliable High Speed Networks: A Model Based Simulation

    Directory of Open Access Journals (Sweden)

    Suman Kumar

    2014-01-01

    Full Text Available Contemporary nature of network evolution demands for simulation models which are flexible, scalable, and easily implementable. In this paper, we propose a fluid based model for performance analysis of reliable high speed networks. In particular, this paper aims to study the dynamic relationship between congestion control algorithms and queue management schemes, in order to develop a better understanding of the causal linkages between the two. We propose a loss synchronization module which is user configurable. We validate our model through simulations under controlled settings. Also, we present a performance analysis to provide insights into two important issues concerning 10 Gbps high speed networks: (i impact of bottleneck buffer size on the performance of 10 Gbps high speed network and (ii impact of level of loss synchronization on link utilization-fairness tradeoffs. The practical impact of the proposed work is to provide design guidelines along with a powerful simulation tool to protocol designers and network developers.

  2. Synchronicity from Synchronized Chaos

    Directory of Open Access Journals (Sweden)

    Gregory S. Duane

    2015-03-01

    Full Text Available The synchronization of loosely-coupled chaotic oscillators, a phenomenon investigated intensively for the last two decades, may realize the philosophical concept of “synchronicity”—the commonplace notion that related eventsmysteriously occur at the same time. When extended to continuous media and/or large discrete arrays, and when general (non-identical correspondences are considered between states, intermittent synchronous relationships indeed become ubiquitous. Meaningful synchronicity follows naturally if meaningful events are identified with coherent structures, defined by internal synchronization between remote degrees of freedom; a condition that has been posited as necessary for synchronizability with an external system. The important case of synchronization between mind and matter is realized if mind is analogized to a computer model, synchronizing with a sporadically observed system, as in meteorological data assimilation. Evidence for the ubiquity of synchronization is reviewed along with recent proposals that: (1 synchronization of different models of the same objective process may be an expeditious route to improved computational modeling and may also describe the functioning of conscious brains; and (2 the nonlocality in quantum phenomena implied by Bell’s theorem may be explained in a variety of deterministic (hidden variable interpretations if the quantum world resides on a generalized synchronization “manifold”.

  3. Spontaneous emergence of large-scale cell cycle synchronization in amoeba colonies

    Science.gov (United States)

    Segota, Igor; Boulet, Laurent; Franck, David; Franck, Carl

    2014-06-01

    Unicellular eukaryotic amoebae Dictyostelium discoideum are generally believed to grow in their vegetative state as single cells until starvation, when their collective aspect emerges and they differentiate to form a multicellular slime mold. While major efforts continue to be aimed at their starvation-induced social aspect, our understanding of population dynamics and cell cycle in the vegetative growth phase has remained incomplete. Here we show that cell populations grown on a substrate spontaneously synchronize their cell cycles within several hours. These collective population-wide cell cycle oscillations span millimeter length scales and can be completely suppressed by washing away putative cell-secreted signals, implying signaling by means of a diffusible growth factor or mitogen. These observations give strong evidence for collective proliferation behavior in the vegetative state.

  4. Relationship between photosynthetic metabolism and cell cycle in a synchronized culture of the marine alga Cylindrotheca fusiformis (Bacillariophyceae)

    NARCIS (Netherlands)

    Claquin, P.; Kromkamp, J.C.; Martin-Jezequel, V.

    2004-01-01

    The aim of this study was to characterize the variation and regulation of photosynthetic carbon metabolism in Cylindrotheca fusiformis during the cell cycle. The cells were synchronized using two cell cycle inhibitors: one for cells grown under light:dark cycles and one for growth in continuous

  5. Relationship between photosynthetic metabolism and cell cycle in a synchronized culture of the marine alga Cylindrotheca fusiformis (Bacillariophyceae)

    NARCIS (Netherlands)

    Claquin, P.; Kromkamp, J.C.; Martin-Jezequel, V.

    2004-01-01

    The aim of this study was to characterize the variation and regulation of photosynthetic carbon metabolism in Cylindrotheca fusiformis during the cell cycle. The cells were synchronized using two cell cycle inhibitors: one for cells grown under light:dark cycles and one for growth in continuous ligh

  6. Development of a synchronous enzyme-reaction system for a highly sensitive enzyme immunoassay.

    Science.gov (United States)

    Inouye, Kuniyo; Ueno, Iori; Yokoyama, Shin-ichi; Sakaki, Toshiyuki

    2002-01-01

    A synchronous enzyme-reaction system using water-soluble formazan and a non-enzymatic electron mediator was developed and applied to an enzyme immunoassay (EIA). The reaction system consists of four steps: (I) dephosphorylation of NADP(+) to produce NAD(+) by alkaline phosphatase (ALP), (II) reduction of NAD(+) to produce NADH with oxidation of ethanol to yield acetaldehyde by alcohol dehydrogenase (ADH), (III) reduction of water-soluble tetrazolium salt (WST-1) to produce formazan by NADH via 1-methoxy-5-methyl-phenazinium methyl sulfate (PMS), and (IV) re-reduction of NAD(+) to produce NADH by ADH. During each cycle, one molecule of tetrazolium is converted to one molecule of formazan. The concentration of formazan during the reaction was given by second-order polynomials of the reaction time. Kinetic studies strongly suggested that the synchronous enzyme-reaction system had the potential to detect an analyte at the attomole level in EIA. On the basis of the kinetic studies, optimal conditions for EIA incorporating the synchronous system were examined. NADP(+) was purified thoroughly to remove minor traces of NAD(+) in the preparation, and an ADH preparation contaminated with the lowest level of ALP activity was used. When the synchronous system was applied to a sandwich-type EIA for human C-reactive protein, the protein was detected with a sensitivity of 50 attomole per well of a micro-titer plate (0.1 ml) in a 1-h reaction. In addition, EIA with water-soluble formazan showed a more quantitative and sensitive result than that with insoluble formazan. These findings indicated that the (WST-1)-PMS system introduced in this study has a great potential for highly sensitive enzyme immunoassay.

  7. Waves of Cdk1 Activity in S Phase Synchronize the Cell Cycle in Drosophila Embryos.

    Science.gov (United States)

    Deneke, Victoria E; Melbinger, Anna; Vergassola, Massimo; Di Talia, Stefano

    2016-08-22

    Embryos of most metazoans undergo rapid and synchronous cell cycles following fertilization. While diffusion is too slow for synchronization of mitosis across large spatial scales, waves of Cdk1 activity represent a possible process of synchronization. However, the mechanisms regulating Cdk1 waves during embryonic development remain poorly understood. Using biosensors of Cdk1 and Chk1 activities, we dissect the regulation of Cdk1 waves in the Drosophila syncytial blastoderm. We show that Cdk1 waves are not controlled by the mitotic switch but by a double-negative feedback between Cdk1 and Chk1. Using mathematical modeling and surgical ligations, we demonstrate a fundamental distinction between S phase Cdk1 waves, which propagate as active trigger waves in an excitable medium, and mitotic Cdk1 waves, which propagate as passive phase waves. Our findings show that in Drosophila embryos, Cdk1 positive feedback serves primarily to ensure the rapid onset of mitosis, while wave propagation is regulated by S phase events. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Phase and Antiphase Synchronization between 3-Cell CNN and Volta Fractional-Order Chaotic Systems via Active Control

    Directory of Open Access Journals (Sweden)

    Zahra Yaghoubi

    2012-01-01

    Full Text Available Synchronization of fractional-order chaotic dynamical systems is receiving increasing attention owing to its interesting applications in secure communications of analog and digital signals and cryptographic systems. In this paper, a drive-response synchronization method is studied for “phase and antiphase synchronization” of a class of fractional-order chaotic systems via active control method, using the 3-cell and Volta systems as an example. These examples are used to illustrate the effectiveness of the synchronization method.

  9. Head and neck squamous cell carcinoma (HNSCC) - detection of synchronous primaries with {sup 18}F-FDG-PET/CT

    Energy Technology Data Exchange (ETDEWEB)

    Strobel, Klaus; Schrank, Madeleine; Soyka, Jan D.; Veit-Haibach, Patrick; Hany, Thomas F. [University Hospital Zurich, Division of Nuclear Medicine, Department of Medical Radiology, Zurich (Switzerland); Haerle, Stephan K.; Stoeckli, Sandro J. [University Hospital Zurich, Department of Otorhinolaryngology, Head and Neck Surgery, Zurich (Switzerland)

    2009-06-15

    The aim of the study was to evaluate {sup 18}F-FDG-PET/CT for the detection of synchronous primaries at initial staging of patients with head and neck squamous cell carcinoma (HNSCC). FDG-PET/CT images acquired between March 2001 and October 2007 in 589 consecutive patients (147 women, 442 men; mean age 61.5 years, age range 32-97 years) with proven HNSCC were reviewed for the presence of synchronous primaries. Cytology, histology and/or clinical and imaging follow-up served as reference standard. FDG-PET/CT showed 69 suspected synchronous primaries in 62 patients of which 56 were finally confirmed in 44 patients. Of the 56 second cancers, 46 (82%) were found in the aerodigestive tract in the following locations: lung (26, 46%), head and neck (15, 17%), oesophagus (5, 9%). Ten second cancers (18%) were located outside the aerodigestive tract (colon, five; stomach, lymphoma, breast, thymus and kidney, one each). Six patients had three synchronous primaries and three patients had four synchronous cancers. Nine synchronous cancers were not detected by PET/CT (four head and neck, two lung, two oesophageal, one gastric). False-positive PET/CT findings were mainly related to benign FDG uptake in the intestine due to benign or precancerous polyps or physiological FDG uptake in other head and neck regions. Overall the prevalence of synchronous second primaries according to the reference standard was 9.5%, of which 84% were detected with FDG-PET/CT. In 80% of the patients, therapy was changed because of the detection of a synchronous primary. FDG-PET/CT detects a considerable number of synchronous primaries (8.0% prevalence) at initial staging of patients with HNSCC. Synchronous cancers were predominantly located in the aerodigestive tract, primarily in the lung, head and neck and oesophagus. Detection of second primaries has an important impact on therapy. PET/CT should be performed before panendoscopy. (orig.)

  10. Roscovitine treatment improves synchronization of donor cell cycle in G0/G1 stage and in vitro development of handmade cloned buffalo (Bubalus bubalis) embryos.

    Science.gov (United States)

    Selokar, Naresh L; Saini, Monika; Muzaffer, Mushariffa; Krishnakanth, G; Saha, Ambika P; Chauhan, Manmohan S; Manik, Radheysham; Palta, Prabhat; Madan, Pavneesh; Singla, Suresh K

    2012-04-01

    This study investigated the effects of serum-starvation, total confluence, and roscovitine treatment on cell-cycle synchronization of buffalo ear skin fibroblasts to the G0/G1 stage and on the developmental competence of cloned embryos. Serum starvation of total confluence cultures for 24 h had a higher (proscovitine treatment than that with 10 μM (94.4, 96.4, and 86.6%, respectively), which was similar to that for total confluence (86.0%). MTT assay showed that cell viability decreased as dose of roscovitine increased. The blastocyst rate was significantly higher (proscovitine-treated (20 and 30 μM) groups (48.8, 48.9, 57.9, and 62.9%, respectively) compared to nontreated cyclic cells (20.2%). However, the cleavage rate and total cell number of cloned embryos were similar for all the groups. The number of ICM cells was improved by 30 μM roscovitine treatment (45.25 ± 2.34). The cryosurvival rate of blastocysts derived from cells synchronized with 20 or 30 μM roscovitine was higher compared to that for total confluence group (33.6, 37.8 vs. 23.8%). In conclusion, treatment with 30 μM roscovitine is optimal for harvesting G0/G1 stage cells for producing high quality cloned buffalo embryos, and that it is better than serum-starvation or total confluence for cell synchronization.

  11. Phase and Antiphase Synchronization between 3-Cell CNN and Volta Fractional-Order Chaotic Systems via Active Control

    OpenAIRE

    Zahra Yaghoubi; Hassan Zarabadipour

    2012-01-01

    Synchronization of fractional-order chaotic dynamical systems is receiving increasing attention owing to its interesting applications in secure communications of analog and digital signals and cryptographic systems. In this paper, a drive-response synchronization method is studied for “phase and antiphase synchronization” of a class of fractional-order chaotic systems via active control method, using the 3-cell and Volta systems as an example. These examples are used to illustrate the effecti...

  12. A systemized approach to investigate Ca2+ synchronization in clusters of human induced pluripotent stem-cell derived cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Aled R Jones

    2016-01-01

    Full Text Available Induced pluripotent stem cell-derived cardiomyocytes (IPS-CM are considered by many to be the cornerstone of future approaches to repair the diseased heart. However, current methods for producing IPS-CM typically yield highly variable populations with low batch-to-batch reproducibility. The underlying reasons for this are not fully understood. Here we report on a systematized approach to investigate the effect of maturation in embryoid bodies (EB versus ‘on plate’ culture on spontaneous activity and regional Ca2+ synchronization in IPS-CM clusters. A detailed analysis of the temporal and spatial organization of Ca2+ spikes in IPS-CM clusters revealed that the disaggregation of EBs between 0.5 and 2 weeks produced IPS-CM characterized by spontaneous beating and high levels of regional Ca2+ synchronization. These phenomena were typically absent in IPS-CM obtained from older EBs (> 2 weeks. The maintenance of all spontaneously active IPS-CM clusters under ‘on plate’ culture conditions promoted the progressive reduction in regional Ca2+ synchronization and the loss of spontaneous Ca2+ spiking. Raising the extracellular [Ca2+] surrounding these quiescent IPS-CM clusters from approximately 0.4 to 1.8 mM unmasked discrete behaviours typified by either a long-lasting Ca2+ elevation that returned to baseline or b persistent, large-amplitude Ca2+ oscillations around an increased cytoplasmic [Ca2+]. The different responses of IPS-CM to elevated extracellular [Ca2+] could be traced back to their routes of derivation. The data point to the possibility of predictably influencing IPS-CM phenotype and response to external activation via defined interventions at early stages in their maturation.

  13. Mimosine As Well As Serum Starvation Can Be Used for Cell Cycle Synchronization of Sheep Granulosa Cells

    Directory of Open Access Journals (Sweden)

    Fatemeh Sadeghian-Nodoushan

    2014-01-01

    Full Text Available This study was evaluated the effect of different synchronization protocols such as serum starvation for 1–3 days, confluency and chemical inhibitors on synchronization accuracy at G0/G1, apoptosis, and DNA synthesis in sheep granulosa cells. The cells were obtained from ovarian antral follicles of slaughtered sheep and used at first and fifth passages. Flow cytometry analysis showed that confluent cells, serum starvation for 24, 48, and 72 hours, and mimosine treatment significantly increased G0/G1 phase cells when compared to normally growing cells (P<0.05. Nocodazole treatment increased the cell population in the G0/G1 stage when compared with the control group but did not change the G2/M stage population. Treatment of cells with mimosine, nocodazole, and serum starvation in three groups resulted in proliferation arrest (P<0.05. Serum starvation for 72 hours significantly promoted apoptosis in granulosa cells (P<0.05. The results of the primary culture and 5th passage were the same. The use of 48-hour serum starvation and mimosine treatments has been recommended because cell death in these groups was very similar to the control group.

  14. Synchronous unilateral basal cell adenoma of the parotid gland: A case report.

    Science.gov (United States)

    Kuang, Jin; Rao, Qian; Zhang, Hao; Cheng, Zhigang

    2014-10-01

    The current study reports the case of a 68-year-old male who presented with a 4-month history of a painless slow-growing mass in the left parotid region. Magnetic resonance imaging revealed two independent, round lesions in the superficial and deep lobes of the parotid gland on the left side, respectively. A total parotidectomy was performed and basal cell adenomas (BCAs) were identified by histopathological examination. At the 6-month follow-up examination, no sign of recurrence was found. This study describes the clinical features of a rare case of synchronous unilateral BCA in the parotid gland and also provides a review of the literature.

  15. Receiver Jitter Tracking Characteristics in High-Speed Source Synchronous Links

    Directory of Open Access Journals (Sweden)

    Ahmed Ragab

    2011-01-01

    Full Text Available High-speed links which employ source synchronous clocking architectures have the ability to track correlated jitter between clock and data channels up to high frequencies. However, system timing margins are degraded by channel skew between clock and data signals and high-frequency loss. This paper describes how these key channel effects impact the jitter performance and influence the clocking architecture of high-speed source synchronous links. Tradeoffs in complexity and jitter tracking performance of common per-channel de-skew circuits are discussed, along with how band-pass filtering can be leveraged to provide additional jitter filtering at the receiver. Jitter tolerance analysis for a 10 Gb/s system shows that a near all-pass delay-locked loop (DLL and phase-interpolator- (PI- based de-skew performs best under low skew conditions, while, at high skew, architectures which leverage band-pass clock filtering or a phase-locked loop (PLL for increased jitter filtering are more suitable. De-skew based on injection-locked oscillators (ILOs offer a reduced complexity design and competitive jitter tolerance over a wide skew range.

  16. Multi-antenna synchronized global navigation satellite system receiver and its advantages in high-precision positioning applications

    Science.gov (United States)

    Dong, Danan; Chen, Wen; Cai, Miaomiao; Zhou, Feng; Wang, Minghua; Yu, Chao; Zheng, Zhengqi; Wang, Yuanfei

    2016-12-01

    The multi-antenna synchronized global navigation satellite system receiver is a high precision, low cost, and widely used emerging receiver. Using this type of receiver, the satellite and receiver clock errors can be eliminated simultaneously by forming between antenna single-differences, which is equivalent to the conventional double-difference model. However, current multi-antenna synchronized global navigation satellite system receiver products have not fully realized their potential to achieve better accuracy, efficiency, and broader applications. This paper introduces the conceptual design and derivable products of multi-antenna synchronized global navigation satellite system receivers involving the aspects of attitude determination, multipath effect mitigation, phase center variation correction, and ground-based carrier phase windup calibration. Through case studies, the advantages of multi-antenna synchronized global navigation satellite system receivers in high-precision positioning applications are demonstrated.

  17. Synchronous Malignant Otitis Externa and Squamous Cell Carcinoma of the External Auditory Canal

    Directory of Open Access Journals (Sweden)

    R. Y. Chin

    2013-01-01

    Full Text Available Objectives. To discuss the management of a squamous cell carcinoma in the presence of malignant otitis externa. Study Design. We present only the third reported case in the literature of a synchronous tumour with malignant otitis externa in the literature. Methods. A case report and review of malignant otitis externa and squamous cell carcinomas of the external auditory canal are discussed. Results. A 66-year-old female is presented here with a 2-month history of a painful, discharging left ear refractory to standard antibiotic therapy. Computerised tomography, magnetic resonance imaging, technetium 99 m, and gallium citrate Ga67 scans were consistent with malignant otitis externa. Biopsy in the operating theatre revealed a synchronous squamous cell carcinoma of the external auditory canal. Primary resection of the tumour and surrounding tissues was performed with concomitant treatment with intravenous antibiotics. Conclusions. This is only the third case to be reported in the literature and highlights several important diagnostic and management issues of these two rare conditions. Both conditions may present in a similar manner on clinical assessment and radiological investigations. Aggressive management with surgical resection and treatment with appropriate intravenous antibiotics is necessary to give the best chance for cure.

  18. A phase synchronization clustering algorithm for identifying interesting groups of genes from cell cycle expression data

    Directory of Open Access Journals (Sweden)

    Tcha Hong

    2008-01-01

    Full Text Available Abstract Background The previous studies of genome-wide expression patterns show that a certain percentage of genes are cell cycle regulated. The expression data has been analyzed in a number of different ways to identify cell cycle dependent genes. In this study, we pose the hypothesis that cell cycle dependent genes are considered as oscillating systems with a rhythm, i.e. systems producing response signals with period and frequency. Therefore, we are motivated to apply the theory of multivariate phase synchronization for clustering cell cycle specific genome-wide expression data. Results We propose the strategy to find groups of genes according to the specific biological process by analyzing cell cycle specific gene expression data. To evaluate the propose method, we use the modified Kuramoto model, which is a phase governing equation that provides the long-term dynamics of globally coupled oscillators. With this equation, we simulate two groups of expression signals, and the simulated signals from each group shares their own common rhythm. Then, the simulated expression data are mixed with randomly generated expression data to be used as input data set to the algorithm. Using these simulated expression data, it is shown that the algorithm is able to identify expression signals that are involved in the same oscillating process. We also evaluate the method with yeast cell cycle expression data. It is shown that the output clusters by the proposed algorithm include genes, which are closely associated with each other by sharing significant Gene Ontology terms of biological process and/or having relatively many known biological interactions. Therefore, the evaluation analysis indicates that the method is able to identify expression signals according to the specific biological process. Our evaluation analysis also indicates that some portion of output by the proposed algorithm is not obtainable by the traditional clustering algorithm with

  19. High Stability Multi-Wavelength Source by Using Synchronized Etalon Filter in Superfluorescent Fiber Source

    Institute of Scientific and Technical Information of China (English)

    Wencai Huang; Jianping Xie; Hai Ming

    2003-01-01

    We demonstrate a new technique to generate a high stability multi-wavelength fiber source by inserting a synchronized etalon filter in superfluorescent fiber source. Multi-wavelength source can easily be obtained over the EDF gain region with the proposed schedule. By partially feedback diffracted spontaneous emission into erbium doped fiber medium, greater output power, extinction ration and narrower linewidth for each channel than that simply using the spectrum slicing technique is easy obtained. Stable output of multi-wavelength fiber source enables it to replace the DFB laser array with wavelength locker in DWDM application.

  20. Cell-type and state-dependent synchronization among rodent areas S1BF, V1, perirhinal cortex and hippocampus CA1

    Directory of Open Access Journals (Sweden)

    Martin eVinck

    2016-01-01

    Full Text Available Beta and gamma rhythms have been hypothesized to be involved in global and local coordination of neuronal activity, respectively. Here, we investigated how cells in rodent area S1BF are entrained by rhythmic fluctuations at various frequencies within the local area and in connected areas, and how this depends on behavioral state and cell type. We performed simultaneous extracellular field and unit recordings in four connected areas of the freely moving rat (S1BF, V1M, perirhinal cortex, CA1. S1BF spiking activity was strongly entrained by both beta and gamma S1BF oscillations, which were associated with deactivations and activations, respectively. We identified multiple classes of fast spiking and excitatory cells in S1BF, which showed prominent differences in rhythmic entrainment and in the extent to which phase locking was modulated by behavioral state. Using an additional dataset acquired by whole-cell recordings in head-fixed mice, these cell classes could be compared with identified phenotypes showing gamma rhythmicity in their membrane potential. We next examined how S1BF cells were entrained by rhythmic fluctuations in connected brain areas. Gamma-synchronization was detected in all four areas, however we did not detect significant gamma coherence among these areas. Instead, we only found long-range coherence in the theta-beta range among these areas. In contrast to local S1BF synchronization, we found long-range S1BF-spike to CA1-LFP synchronization to be homogeneous across inhibitory and excitatory cell types. These findings suggest distinct, cell-type contributions of low and high-frequency synchronization to intra- and inter-areal neuronal interactions.

  1. Synchronous clear cell renal cell carcinoma and multilocular cystic renal cell neoplasia of low malignant potential: A clinico-pathologic and molecular study.

    Science.gov (United States)

    Raspollini, Maria Rosaria; Castiglione, Francesca; Cheng, Liang; Montironi, Rodolfo; Lopez-Beltran, Antonio

    2016-05-01

    We report a rare case of synchronous clear cell renal cell carcinoma and multilocular cystic renal cell neoplasia of low malignant potential in the same kidney. The tumors were seen incidentally in a 45-year-old man. Pathologic study revealed that the former tumor was nucleolar grade 2, and the multilocular cystic renal cell neoplasia of low malignant potential was nucleolar grade 1. At immunohistochemistry, the clear cells in both tumors were positive for CD10 and CA IX. Interestingly, these uncommon synchronous tumors showed a different KRAS/NRAS mutation analysis that was characterized by KRAS mutation at codon p.G12C in the clear cell renal cell carcinoma, while this mutation was not present in the case of multilocular cystic renal cell neoplasia of low malignant potential. NRAS mutation was not seen in any of the tumors.

  2. Double primary non-small cell lung cancer with synchronous small cell lung cancer N2 nodes: a case report

    OpenAIRE

    Gogakos, Apostolos S; Paliouras, Dimitrios; Rallis, Thomas; Chatzinikolaou, Fotios; Xirou, Persefoni; Tsirgogianni, Katerina; Tsavlis,Drosos; Sachpekidis,Nikos; Tsakiridis, Kosmas; Mpakas, Andreas; Zarogoulidis, Konstantinos; Zissimopoulos, Athanasios; Zarogoulidis, Paul; Barbetakis, Nikolaos

    2015-01-01

    Synchronous multiple primary lung cancer (SMPLC) is rare and very hard to distinguish from metastatic disease. Recent studies indicate the presence of this entity in the lung, with no mention to the involvement of the mediastinum. An extremely rare case of a 68-year-old male with double primary non-small cell lung cancer (NSCLC) in the left upper lobe and N2 positive nodes for small cell lung cancer (SCLC) is presented. Modern diagnostic criteria as well as aggressive curative strategies are ...

  3. Double primary non-small cell lung cancer with synchronous small cell lung cancer N2 nodes: a case report.

    Science.gov (United States)

    Gogakos, Apostolos S; Paliouras, Dimitrios; Rallis, Thomas; Chatzinikolaou, Fotios; Xirou, Persefoni; Tsirgogianni, Katerina; Tsavlis, Drosos; Sachpekidis, Nikos; Tsakiridis, Kosmas; Mpakas, Andreas; Zarogoulidis, Konstantinos; Zissimopoulos, Athanasios; Zarogoulidis, Paul; Barbetakis, Nikolaos

    2015-07-01

    Synchronous multiple primary lung cancer (SMPLC) is rare and very hard to distinguish from metastatic disease. Recent studies indicate the presence of this entity in the lung, with no mention to the involvement of the mediastinum. An extremely rare case of a 68-year-old male with double primary non-small cell lung cancer (NSCLC) in the left upper lobe and N2 positive nodes for small cell lung cancer (SCLC) is presented. Modern diagnostic criteria as well as aggressive curative strategies are encouraged, in order to achieve better survival rates for such patients.

  4. Synchronized Current Oscillations of Formic Acid Electro-oxidation in a Microchip-based Dual-Electrode Flow Cell

    Science.gov (United States)

    Kiss, István Z.; Munjal, Neil; Martin, R. Scott

    2009-01-01

    We investigate the oscillatory electro-oxidation of formic acid on platinum in a microchip-based dual-electrode cell with microfluidic flow control. The main dynamical features of current oscillations on single Pt electrode that had been observed in macro-cells are reproduced in the microfabricated electrochemical cell. In dual-electrode configuration nearly in-phase synchronized current oscillations occur when the reference/counter electrodes are placed far away from the microelectrodes. The synchronization disappears with close reference/counter electrode placements. We show that the cause for synchronization is weak albeit important, bidirectional electrical coupling between the electrodes; therefore the unidirectional mass transfer interactions are negligible. The experimental design enables the investigation of the dynamical behavior in micro-electrode arrays with well-defined control of flow of the electrolyte in a manner where the size and spacing of the electrodes can be easily varied. PMID:20160883

  5. Synchronized Current Oscillations of Formic Acid Electro-oxidation in a Microchip-based Dual-Electrode Flow Cell.

    Science.gov (United States)

    Kiss, István Z; Munjal, Neil; Martin, R Scott

    2009-12-30

    We investigate the oscillatory electro-oxidation of formic acid on platinum in a microchip-based dual-electrode cell with microfluidic flow control. The main dynamical features of current oscillations on single Pt electrode that had been observed in macro-cells are reproduced in the microfabricated electrochemical cell. In dual-electrode configuration nearly in-phase synchronized current oscillations occur when the reference/counter electrodes are placed far away from the microelectrodes. The synchronization disappears with close reference/counter electrode placements. We show that the cause for synchronization is weak albeit important, bidirectional electrical coupling between the electrodes; therefore the unidirectional mass transfer interactions are negligible. The experimental design enables the investigation of the dynamical behavior in micro-electrode arrays with well-defined control of flow of the electrolyte in a manner where the size and spacing of the electrodes can be easily varied.

  6. A surgical robot with a heart-surface-motion synchronization mechanism for myoblast cell sheet transplantation.

    Science.gov (United States)

    Xu, Kangyi; Nakamura, Ryoichi

    2013-01-01

    Myoblast cell sheets are employed in the clinical treatment of heart disorders. We propose a surgical robot system with two endoscopic cameras, characterized by a double remote center of motion (RCM) mechanism, to realize heart-surface-motion synchronization movement for myoblast cell sheet transplantation on a beating heart surface. A robot system with the double RCM mechanism was developed for which the linear and rotation motions are totally isolated, and an experiment was conducted to evaluate the tracking accuracy of the robot system when tracking a randomly moving target. The tracking data were updated with a Polaris system at 30 Hz. The experiment results showed linear and rotation tracking errors of 4.93 ± 5.92 mm and 2.54 ± 5.44°, respectively.

  7. Optimized design of a high-power-density PM-assisted synchronous reluctance machine with ferrite magnets for electric vehicles

    Directory of Open Access Journals (Sweden)

    Liu Xiping

    2017-06-01

    Full Text Available This paper proposes a permanent magnet (PM-assisted synchronous reluctance machine (PMASynRM using ferrite magnets with the same power density as rareearth PM synchronous motors employed in Toyota Prius 2010. A suitable rotor structure for high torque density and high power density is discussed with respect to the demagnetization of ferrite magnets, mechanical strength and torque ripple. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2-D finite element analysis (FEA. The analysis results show that a high power density and high efficiency of PMASynRM are obtained by using ferrite magnets.

  8. Design of High-Performance Asynchronous Pipeline Using Synchronizing Logic Gates

    Science.gov (United States)

    Xia, Zhengfan; Ishihara, Shota; Hariyama, Masanori; Kameyama, Michitaka

    This paper introduces a novel design method of an asynchronous pipeline based on dual-rail dynamic logic. The overhead of handshake control logic is greatly reduced by constructing a reliable critical datapath, which offers the pipeline high throughput as well as low power consumption. Synchronizing Logic Gates (SLGs), which have no data dependency problem, are used in the design to construct the reliable critical datapath. The design targets latch-free and extremely fine-grain or gate-level pipeline, where the depth of every pipeline stage is only one dual-rail dynamic logic. HSPICE simulation results, in a 65nm design technology, indicate that the proposed design increases the throughput by 120% and decreases the power consumption by 54% compared with PS0, a classic dual-rail asynchronous pipeline implementation style, in 4-bit wide FIFOs. Moreover, this method is applied to design an array style multiplier. It shows that the proposed design reduces power by 37.9% compared to classic synchronous design when the workloads are 55%. A chip has been fabricated with a 4×4 multiplier function, which works well at 2.16G data-set/s (Post-layout simulation).

  9. Development of Digital Control for High Power Permanent-Magnet Synchronous Motor Drives

    Directory of Open Access Journals (Sweden)

    Ming-Hung Chen

    2014-01-01

    Full Text Available This paper is concerned with the development of digital control system for high power permanent-magnet synchronous motor (PMSM to yield good speed regulation, low current harmonic, and stable output speed. The design of controller is conducted by digitizing the mathematical model of PMSM using impulse invariance technique. The predicted current estimator, which is insensitive to motor feedback currents, is proposed to function under stationary frame for harmonic current suppression. In the AC/DC power converter, mathematical model and dc-link voltage limit of the three-phase switch-mode rectifier are derived. In addition, a current controller under synchronous frame is introduced to reduce the current harmonics and increase the power factor on the input side. A digital control system for 75 kW PMSM is realized with digital signal processor (R5F5630EDDFP. Experimental results indicate that the total harmonic distortion of current is reduced from 4.1% to 2.8% for 50 kW output power by the proposed predicted current estimator technique.

  10. A RARE CASE REPORT OF SYNCHRONOUS MALIGNANCY – SQUAMOUS CELL CARCINOMA OF BASE OF TONGUE AND ADENO CARCINOMA OF STOMACH

    Directory of Open Access Journals (Sweden)

    Prakash

    2014-11-01

    Full Text Available The synchronous occurrence of primary squamous cell carcinoma of base of tongue with gastric adenocarcinoma is very rare. We report a case of 50 year old male patient presented to ENT OPD with complaints of throat pain, painful swallowing since 1month. Indirect laryngoscopy showed ulceroproliferative growth in Base of tongue, vallecula and epiglottis. Upper GI endoscopy showed ulceroproloferative lesion involving base of tongue, left epiglottis and vallecula. Endoscopic Biopsy from the growth revealed squamous cell carcinoma of the base of the tongue and adeno carcinoma of the stomach. We report this case to highlight a rare occurrence of synchronous malignancy of posterior tongue and stomach

  11. BENZO[a]PYRENE DIOL EPOXIDE PERTURBATION OF CELL CYCLE KINETICS OF SYNCHRONIZED MOUSE LIVER EPITHELIAL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Pearlman, A.L.; Navsky, B.N.; Bartholomew, J.C

    1980-07-01

    A cell cycle synchronization system is described for the analysis of the perturbation of cell cycle kinetics and the cycle-phase specificity of chemicals and other agents. We used the system to study the effects of ({+-})r-7, t-8-dihydroxy-t-9, 10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BaP diol epoxide) upon the cell cycle of mouse liver epithelial cells(NMuLi). BaP diol epoxide(0.6 uM) was added to replated cultures of NMuLi cells that had been synchronized in various stages of the cell cycle by centrifugal elutriation. DNA histograms were obtained by flow cytometry as a function of time after replating. The data were analyzed by a computer modeling routine and reduced to a few graphs illustrating the 'net effects' of the BaP diol epoxide relative to controls. BaP diol epoxide slowed S-phase traversal in all samples relative to their respective control. Traversal through G{sub 2}M was also slowed by at least 50%. BaP diol epoxide had no apparent effect upon G{sub 1} traversal by cycling cells, but delayed the recruitment of quiescent G{sub 0} cells by about 2 hrs. The methods described constitute a powerful new approach for probing the cell cycle effects of a wide variety of agents. The present system appears to be extremely sensitive and capable of characterizing the action of agents on each phase of the cell cycle. The methods are automatable and would allow for the assay and possible differential characterization of mutagens and carcinogens.

  12. ROSA: a high cadence, synchronized multi-camera solar imaging system

    CERN Document Server

    Jess, D B; Christian, D J; Keenan, F P; Ryans, R S I; Crockett, P J

    2009-01-01

    Rapid Oscillations in the Solar Atmosphere (ROSA) is a synchronized, six camera high cadence solar imaging instrument developed by Queen's University Belfast. The system is available on the Dunn Solar Telescope at the National Solar Observatory in Sunspot, New Mexico, USA as a common-user instrument. Consisting of six 1k x 1k Peltier-cooled frame-transfer CCD cameras with very low noise (0.02-15 e/s/pixel), each ROSA camera is capable of full-chip readout speeds in excess of 30 Hz, or 200 Hz when the CCD is windowed. Combining multiple cameras and fast readout rates, ROSA will accumulate approximately 12 TB of data per 8 hours observing. Following successful commissioning during August 2008, ROSA will allow multi-wavelength studies of the solar atmosphere at high temporal resolution.

  13. Synchronizing Progression of Schizosaccharomyces pombe Cells from G2 through Repeated Rounds of Mitosis and S Phase with cdc25-22 Arrest Release.

    Science.gov (United States)

    Hagan, Iain M; Grallert, Agnes; Simanis, Viesturs

    2016-08-01

    Transient inactivation of the cdc25(+) gene product by manipulation of the culture temperature for cdc25-22 cells is the most commonly exploited approach to mitotic synchronization in fission yeast. Because Cdc25 removes the inhibitory phosphate placed on Cdk1 by Wee1, inactivation of Cdc25 arrests cells at the G2/M boundary. Incubation at the restrictive temperature of 36°C for just over one generation time forces all cells in the culture to accumulate at the G2/M boundary. Restoration of Cdc25 function via a return to the permissive temperature or chemical inhibition of Wee1 activity at 36°C can then promote a highly synchronous wave of cell division throughout the culture. These approaches can be performed on any scale and thus support simultaneous assessment of numerous events within a single culture. After describing this simple and widely applicable procedure, we discuss frequently overlooked issues that can have a considerable impact on the interpretation of data from cdc25-22 induction-synchronized cultures.

  14. Hetero-cellular prototyping by synchronized multi-material bioprinting for rotary cell culture system.

    Science.gov (United States)

    Snyder, Jessica; Son, Ae Rin; Hamid, Qudus; Wu, Honglu; Sun, Wei

    2016-01-13

    Bottom-up tissue engineering requires methodological progress of biofabrication to capture key design facets of anatomical arrangements across micro, meso and macro-scales. The diffusive mass transfer properties necessary to elicit stability and functionality require hetero-typic contact, cell-to-cell signaling and uniform nutrient diffusion. Bioprinting techniques successfully build mathematically defined porous architecture to diminish resistance to mass transfer. Current limitations of bioprinted cell assemblies include poor micro-scale formability of cell-laden soft gels and asymmetrical macro-scale diffusion through 3D volumes. The objective of this work is to engineer a synchronized multi-material bioprinter (SMMB) system which improves the resolution and expands the capability of existing bioprinting systems by packaging multiple cell types in heterotypic arrays prior to deposition. This unit cell approach to arranging multiple cell-laden solutions is integrated with a motion system to print heterogeneous filaments as tissue engineered scaffolds and nanoliter droplets. The set of SMMB process parameters control the geometric arrangement of the combined flow's internal features and constituent material's volume fractions. SMMB printed hepatocyte-endothelial laden 200 nl droplets are cultured in a rotary cell culture system (RCCS) to study the effect of microgravity on an in vitro model of the human hepatic lobule. RCCS conditioning for 48 h increased hepatocyte cytoplasm diameter 2 μm, increased metabolic rate, and decreased drug half-life. SMMB hetero-cellular models present a 10-fold increase in metabolic rate, compared to SMMB mono-culture models. Improved bioprinting resolution due to process control of cell-laden matrix packaging as well as nanoliter droplet printing capability identify SMMB as a viable technique to improve in vitro model efficacy.

  15. Determination of High-Frequency d- and q-axis Inductances for Surface-Mounted Permanent-Magnet Synchronous Machines

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Vetuschi, M.; Rasmussen, Peter Omand;

    2010-01-01

    This paper presents a reliable method for the experimental determination of high-frequency d- and q -axis inductances for surface-mounted permanent-magnet synchronous machines (SMPMSMs). Knowledge of the high-frequency d- and q-axis inductances plays an important role in the efficient design...

  16. High-resolution time series of Pseudomonas aeruginosa gene expression and rhamnolipid secretion through growth curve synchronization

    Directory of Open Access Journals (Sweden)

    Xavier João B

    2011-06-01

    Full Text Available Abstract Background Online spectrophotometric measurements allow monitoring dynamic biological processes with high-time resolution. Contrastingly, numerous other methods require laborious treatment of samples and can only be carried out offline. Integrating both types of measurement would allow analyzing biological processes more comprehensively. A typical example of this problem is acquiring quantitative data on rhamnolipid secretion by the opportunistic pathogen Pseudomonas aeruginosa. P. aeruginosa cell growth can be measured by optical density (OD600 and gene expression can be measured using reporter fusions with a fluorescent protein, allowing high time resolution monitoring. However, measuring the secreted rhamnolipid biosurfactants requires laborious sample processing, which makes this an offline measurement. Results Here, we propose a method to integrate growth curve data with endpoint measurements of secreted metabolites that is inspired by a model of exponential cell growth. If serial diluting an inoculum gives reproducible time series shifted in time, then time series of endpoint measurements can be reconstructed using calculated time shifts between dilutions. We illustrate the method using measured rhamnolipid secretion by P. aeruginosa as endpoint measurements and we integrate these measurements with high-resolution growth curves measured by OD600 and expression of rhamnolipid synthesis genes monitored using a reporter fusion. Two-fold serial dilution allowed integrating rhamnolipid measurements at a ~0.4 h-1 frequency with high-time resolved data measured at a 6 h-1 frequency. We show how this simple method can be used in combination with mutants lacking specific genes in the rhamnolipid synthesis or quorum sensing regulation to acquire rich dynamic data on P. aeruginosa virulence regulation. Additionally, the linear relation between the ratio of inocula and the time-shift between curves produces high-precision measurements of

  17. Complete en bloc urinary exenteration for synchronous multicentric transitional cell carcinoma with sarcomatoid features in a hemodialysis patient

    Directory of Open Access Journals (Sweden)

    Tiberio M. Siqueira Jr

    2006-10-01

    Full Text Available The incidence of transitional cell carcinoma (TCC in patients submitted to hemodialysis is low. The presence of TCC with sarcomatoid features in this cohort is even scarcer. Herein, we describe a very rare case of synchronous multicentric muscle invasive bladder carcinoma with prostate invasion in a hemodialysis patient, submitted to complete en bloc urinary exenteration.

  18. [Effect of inhibitors serine/threonine protein kinases and protein phosphatases on mitosis progression of synchronized tobacco by-2 cells].

    Science.gov (United States)

    Sheremet, Ia A; Emets, A I; Azmi, A; Vissenberg, K; Verbelen, J-P; Blium, Ia B

    2012-01-01

    In order to investigate the role of various serine/ threonine protein kinases and protein phosphatases in the regulation of mitosis progression in plant cells the influence of cyclin-dependent (olomoucine) and Ca2+ -calmodulin-dependent (W7) protein kinases inhibitors, as well as protein kinase C inhibitors (H7 and staurosporine) and protein phosphatases inhibitor (okadaic acid) on mitosis progression in synchronized tobacco BY-2 cells has been studied. It was found that BY-2 culture treatment with inhibitors of cyclin dependent protein kinases and protein kinase C causes prophase delay, reduces the mitotic index and displaces of mitotic peak as compare with control cells. Inhibition of Ca2+ -calmodulin dependent protein kinases enhances the cell entry into prophase and delays their exit from mitosis. Meanwhile inhibition of serine/threonine protein phosphatases insignificantly enhances of synchronized BY-2 cells entering into all phases of mitosis.

  19. Static synchronous compensator with superconducting magnetic energy storage for high power utility applications

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Marcelo G.; Mercado, Pedro E. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan (Argentina); Watanabe, Edson H. [COPPE, Grupo de Eletronica de Potencia, Universidade Federal do Rio de Janeiro (Brazil)

    2007-08-15

    Power systems security in the case of contingencies is ensured by maintaining adequate 'short-term generation reserve'. This reserve must be appropriately activated by means of the primary frequency control (PFC). Because the generation is an electro-mechanical process, the primary control reserve controllability is not as fast as required, especially by modern power systems. Since the new improvements achieved on the conventional control methods have not been enough to satisfy the high requirements established, the necessity of enhancing the performance of the PFC has arisen. At present, the new energy storage systems (ESS) are a feasible alternative to store excess energy for substituting for the primary control reserve. In this way, it is possible to combine this new ESS with power converter based flexible ac transmission systems (FACTS). This allows an effective exchange of active power with the electric grid and, thus, enhances the PFC. This paper presents an improved PFC scheme incorporating a static synchronous compensator (STATCOM) coupled with a superconducting magnetic energy storage (SMES) device. A detailed full model and a control algorithm based on a decoupled current control strategy of the enhanced compensator are proposed. The integrated STATCOM/SMES controller topology includes three level, multi-pulse, voltage source inverters (VSI) with phase control and incorporates a two quadrant, three level, dc-dc chopper as the interface between the STATCOM and the SMES coil. A novel three level control scheme is proposed by using concepts of instantaneous power in the synchronous rotating d-q reference frame. The dynamic performance of the presented control algorithms is evaluated through digital simulation performed by using SimPowerSystems of SIMULINK/MATLAB {sup trademark}, and technical analysis is performed to obtain conclusions about the benefits of using SMES devices in the PFC of the electric system. Presently, a laboratory scale

  20. Surgery Versus Stereotactic Radiosurgery for Single Synchronous Brain Metastasis from Non-Small Cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    Hui LI; Sheng-cai HOU; Bin HU; Tong LI; Yang Wang; Jin-bai Miao; Bin You; Yi-li Fu

    2009-01-01

    Objective: The aim of this study is to compare the effectiveness of surgery with stereotactic radiosurgery (SRS) for patients with a single synchronous brain metastasis from successfully treated non-small cell lung cancer.Methods: Between 1995 and 2002, 53 patients underwent resection of both primary non-small cell lung cancer and the associated single brain metastasis. There were 33 men and 20 women with a mean age of 57 years (range, 32(85 years). At the time of diagnosis, 42 patients experienced lung cancer related symptoms, whereas 11 patients experienced brain metastases-related symptoms. 42 patients had received thoracic surgery first, and 11 patients had undergone neurosurgery or radiosurgery first. Pneumonectomy was performed in 9 out of 42 patients (21.4%), lobectomies in 30 (71.4%), and wedge resection in 3 (7.2%). 48 patients (90.5%) underwent complete lymphadenectomy. 35 patients underwent brain metastasectomy. 18 underwent SRS.Results: There was no postoperative mortality and severe complications after either lung or brain surgery. Histology showed 34 adenocarcinomas, 16 squamous cell carcinomas, and 3 large cell lung cancers. 15 patients (28.3%) had no evidence of lymph node metastases (N0), 20 patients (37.7%) had hilar metastases (N1), and 18 patients (34%) had mediastinal metastases (N2). The 1-, 2-, 3- and 5-year overall survival rates were 49%, 19%, 10%, and 5%, respectively. The corresponding data for neurosurgery group were 55%, 17%, 11%, and 6%, respectively. The median survival time was 13 months. For SRS group the corresponding data were 44.8%, 20.9% 10.5%, and 2%, respectively. The median survival time was 14 months. The differences between the two groups were not significant (P>0.05). In lymph node negative patients (N0), the overall 5-year survival rate was 10%, as compared with a 1% survival rate in patients with lymph node metastases (N1(2). The difference was significant (P0.05).Conclusion: Although the overall survival rate for

  1. Synchronous multicentric small hepatocellular carcinomas: Defining the capsule on high-frequency intraoperative ultrasonography with pathologic correction

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Jae Hong; Eom, Dae Woon; Ryu, Dae Shick; Park, Man Soo; Jung, Seung Mun; Choi, Kun Moo; Cheon, Gab Jin; Choi, Soo Jung; Jang, Hyuk Jai [Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

    2016-08-15

    The aim of this study was to define the capsules of synchronous multicentric small hepatocellular carcinomas (HCCs) with use of high-frequency intraoperative ultrasonography (IOUS). Among the 131 consecutive patients undergoing hepatic resection and high-frequency IOUS for HCC, 16 synchronous multicentric small HCCs in 13 patients were histologically diagnosed in the resected specimens. High-frequency IOUS and pathologic findings of these lesions were compared, with particular focus on the presence and appearance of the capsule in or around each lesion. Synchronous multicentric small HCCs were pathologically classified into distinctly nodular (n=12) or vaguely nodular (n=4) types. All 12 distinctly nodular HCCs including six subcentimeter lesions showed detectable capsules on high-frequency IOUS and pathology. The capsules appeared as a hypoechoic rim containing hyperechoic foci (n=6), hypoechoic rim (n=5), or hyperechoic rim (n=1) with varying degrees of coverage around each lesion. Histologically, the capsules were composed of a combination of one to four layers consisting of a fibrous capsule, peritumoral fibrosis, prominent small vessels, and entrapped hepatic parenchyma. Synchronous multicentric small HCCs with distinctly nodular type, even at subcentimeter size, can show capsules with varying coverage and diverse echogenicity on high-frequency IOUS.

  2. Numerical Analysis of the Dynamic Behavior of a High Power Salient Pole Synchronous Machine by using a Corrected Model

    Directory of Open Access Journals (Sweden)

    CAMPEANU, A.

    2012-02-01

    Full Text Available In the paper is shown that, by using the circuit theory which operates with lumped parameters, it is possible to derive mathematical models of a high power salient pole synchronous machine (SPSM, that can take into account the basic processes of the machine. It offers results regarding the electromagnetic and mechanical stresses for a given practical application. The quantitative determinations were performed on an 8000 kW synchronous motor. The results of quantitative determinations are of essential interest in the designing stage, for dynamic characteristics and parameters derivation and for constructive solutions to be chosen.

  3. A rare tumoral combination, synchronous lung adenocarcinoma and mantle cell lymphoma of the pleura

    Directory of Open Access Journals (Sweden)

    Foroulis Christophoros N

    2008-12-01

    Full Text Available Abstract Background Coexistence of adenocarcinoma and mantle cell lymphoma in the same or different anatomical sites is extremely rare. We present a case of incidental discovery of primary lung adenocarcinoma and mantle cell lymphoma involving the pleura, during an axillary thoracotomy performed for a benign condition. Case presentation A 73-year old male underwent bullectomy and apical pleurectomy for persistent pneumothorax. A bulla of the lung apex was resected en bloc with a scar-like lesion of the lung, which was located in proximity with the bulla origin, by a wide wedge resection. Histologic examination of the stripped-off parietal pleura and of the bullectomy specimen revealed the synchronous occurrence of two distinct neoplasms, a lymphoma infiltrating the pleura and a primary, early lung adenocarcinoma. Immunohistochemical and fluorescence in situ hybridization assays were performed. The morphologic, immunophenotypic and genetic findings supported the diagnosis of primary lung adenocarcinoma (papillary subtype coexisting with a non-Hodgkin, B-cell lineage, mantle cell lymphoma involving both, visceral and parietal pleura and without mediastinal lymph node involvement. The neoplastic lymphoid cells showed the characteristic immunophenotype of mantle cell lymphoma and the translocation t(11;14. The patient received 6 cycles of chemotherapy, while pulmonary function tests precluded further pulmonary parenchyma resection (lobectomy for his adenocarcinoma. The patient is alive and without clinical and radiological findings of local recurrence or distant relapse from both tumors 14 months later. Conclusion This is the first reported case of a rare tumoral combination involving simultaneously lung and pleura, emphasizing at the incidental discovery of the two coexisting neoplasms during a procedure performed for a benign condition. Any tissue specimen resected during operations performed for non-tumoral conditions should be routinely sent for

  4. All-digital duty-cycle corrector with synchronous and high accuracy output for double date rate synchronous dynamic random-access memory application

    Science.gov (United States)

    Tsai, Chih-Wei; Lo, Yu-Lung; Chang, Chia-Chen; Liu, Han-Ying; Yang, Wei-Bin; Cheng, Kuo-Hsing

    2017-04-01

    A synchronous and highly accurate all-digital duty-cycle corrector (ADDCC), which uses simplified dual-loop architecture, is presented in this paper. To explain the operational principle, a detailed circuit description and formula derivation are provided. To verify the proposed design, a chip was fabricated through the 0.18-µm standard complementary metal oxide semiconductor process with a core area of 0.091 mm2. The measurement results indicate that the proposed ADDCC can operate between 300 and 600 MHz with an input duty-cycle range of 40–60%, and that the output duty-cycle error is less than 1% with a root-mean-square jitter of 3.86 ps.

  5. 基于DDS的高速定时同步方法%High-speed timing synchronization method based on DDS

    Institute of Scientific and Technical Information of China (English)

    项春萍

    2012-01-01

    定时同步是高速数据传输的关键技术也是难点问题.在对锁相环数字化设计、DDS原理结构和参数设计进行研究的基础上,提出了一种基于DDS的高速定时同步方法,对该定时同步方法的原理结构框图进行了详细的论述,对具体参数进行了设计.采用这种定时同步方法的高速解调器进行了原理实验测试,取得了满意的结果,所提出的定时同步方法对高速数据传输方案设计提供了参考.%Timing synchronization is a key technology in high rate transmission. The phase locked loop digital design, the principle of DDS structure and parameter design are also analyzed. A high speed timing synchronization method based on DDS is put forward. The principle block diagram is discussed in detail. The specific parameters are designed. A high speed demodulator applied to this timing synchronization method has been tested. The result is satisfied. The timing synchronization method is a design reference for high-speed data transmission.

  6. A synchronous Gigabit Ethernet protocol stack for high-throughput UDP/IP applications

    CERN Document Server

    Födisch, P; Sandmann, J; Büchner, A; Enghardt, W; Kaever, P

    2015-01-01

    State of the art detector readout electronics require high-throughput data acquisition (DAQ) systems. In many applications, e. g. for medical imaging, the front-end electronics are set up as separate modules in a distributed DAQ. A standardized interface between the modules and a central data unit is essential. The requirements on such an interface are varied, but demand almost always a high throughput of data. Beyond this challenge, a Gigabit Ethernet interface is predestined for the broad requirements of Systems-on-a-Chip (SoC) up to large-scale DAQ systems. We have implemented an embedded protocol stack for a Field Programmable Gate Array (FPGA) capable of high-throughput data transmission and clock synchronization. A versatile stack architecture for the User Datagram Protocol (UDP) and Internet Control Message Protocol (ICMP) over Internet Protocol (IP) such as Address Resolution Protocol (ARP) as well as Precision Time Protocol (PTP) is presented. With a point-to-point connection to a host in a MicroTCA ...

  7. In silico synchronization reveals regulators of nuclear ruptures in lamin A/C deficient model cells

    Science.gov (United States)

    Robijns, J.; Molenberghs, F.; Sieprath, T.; Corne, T. D. J.; Verschuuren, M.; de Vos, W. H.

    2016-07-01

    The nuclear lamina is a critical regulator of nuclear structure and function. Nuclei from laminopathy patient cells experience repetitive disruptions of the nuclear envelope, causing transient intermingling of nuclear and cytoplasmic components. The exact causes and consequences of these events are not fully understood, but their stochastic occurrence complicates in-depth analyses. To resolve this, we have established a method that enables quantitative investigation of spontaneous nuclear ruptures, based on co-expression of a firmly bound nuclear reference marker and a fluorescent protein that shuttles between the nucleus and cytoplasm during ruptures. Minimally invasive imaging of both reporters, combined with automated tracking and in silico synchronization of individual rupture events, allowed extracting information on rupture frequency and recovery kinetics. Using this approach, we found that rupture frequency correlates inversely with lamin A/C levels, and can be reduced in genome-edited LMNA knockout cells by blocking actomyosin contractility or inhibiting the acetyl-transferase protein NAT10. Nuclear signal recovery followed a kinetic that is co-determined by the severity of the rupture event, and could be prolonged by knockdown of the ESCRT-III complex component CHMP4B. In conclusion, our approach reveals regulators of nuclear rupture induction and repair, which may have critical roles in disease development.

  8. High-Order Sliding Mode-Based Synchronous Control of a Novel Stair-Climbing Wheelchair Robot

    Directory of Open Access Journals (Sweden)

    Juanxiu Liu

    2015-01-01

    Full Text Available For the attitude control of a novel stair-climbing wheelchair with inertial uncertainties and external disturbance torques, a new synchronous control method is proposed via combing high-order sliding mode control techniques with cross-coupling techniques. For this purpose, a proper controller is designed, which can improve the performance of the system under conditions of uncertainties and torque perturbations and also can guarantee the synchronization of the system. Firstly, a robust high-order sliding mode control law is designed to track the desired position trajectories effectively. Secondly, considering the coordination of the multiple joints, a high-order sliding mode synchronization controller is designed to reduce the synchronization errors and tracking errors based on the controller designed previously. Stability of the closed-loop system is proved by Lyapunov theory. The simulation is performed by MATLAB to verify the effectiveness of the proposed controller. By comparing the simulation results of two controllers, it is obvious that the proposed scheme has better performance and stronger robustness.

  9. Synchronized High-Resolution Lacustrine Records in Iceland show Non-Linear Response to Holocene Insolation

    Science.gov (United States)

    Geirsdottir, A.; Miller, G. H.; Larsen, D. J.; Thordarson, T.; Ólafsdóttir, S.; Stoner, J. S.

    2010-12-01

    Icelandic lakes commonly have sedimentation rates in excess of 1 m ka-1 through the Holocene, offering the potential for records of environmental change at decadal or better resolution. Icelandic lake sediment contains numerous volcanic tephra layers of known age, which together with high-resolution sediment paleomagnetic secular variations (PSV) allow synchronization of sediment cores from both lacustrine and marine archives. We present synchronized high-resolution paleoclimatic records from two Icelandic lakes with very different catchment characteristics. By combining PSV records and key tephra tie points we are able to synchronize the lacustrine records with each other and with a well-dated marine core from the shelf north of Iceland. The large PSV signal that characterizes the Icelandic Holocene records allows 40 to 60 secure tie points over the past 10 ka of sediment records. The high frequency of tie points allows the reconstruction of sediment accumulation rate changes in the lacustrine records that were not apparent from the tephrochonological controls. The first order trends in the lacustine climate proxies (BSi and TOC) are similar. BSi climbs to a maximum value shortly after 8 ka, then declines toward present, reflecting a relatively late Holocene thermal maximum, lagging the Greenland ice core record by ca. 2 ka. The peak of the HTM in Iceland was warm enough to melt glaciers completely with temperatures estimated to have been 3.5°C higher relative to 1960-1990 averages. Decreasing summer insolation is reflected not by gradual cooling after the HTM, but by incremental changes in state. TOC and BSi track each other during warm times, but diverge, and sedimentation rates increase, during perturbations and cold times at 8.4 ka, 5.5 ka, 4.3 to 4 ka, 3.1 ka to 2.8 ka. Following these departures, BSi usually exhibits a step-function change, re-equilibrating at a lower BSi value. Some of the departures may be related to Icelandic volcanism influencing

  10. Detection of Changes in the Medicago sativa Retinoblastoma-Related Protein (MsRBR1) Phosphorylation During Cell Cycle Progression in Synchronized Cell Suspension Culture.

    Science.gov (United States)

    Ayaydin, Ferhan; Kotogány, Edit; Ábrahám, Edit; Horváth, Gábor V

    2017-01-01

    Deepening our knowledge on the regulation of the plant cell division cycle depends on techniques that allow for the enrichment of cell populations in defined cell cycle phases. Synchronization of cell division can be achieved using different plant tissues; however, well-established cell suspension cultures provide large amount of biological sample for further analyses. Here, we describe the methodology of the establishment, propagation, and analysis of a Medicago sativa suspension culture that can be used for efficient synchronization of the cell division. A novel 5-ethynyl-2'-deoxyuridine (EdU)-based method is used for the estimation of cell fraction that enters DNA synthesis phase of the cell cycle and we also demonstrate the changes in the phosphorylation level of Medicago sativa retinoblastoma-related protein (MsRBR1) during cell cycle progression.

  11. Study on a high thrust force bi-double-sided permanent magnet linear synchronous motor

    Directory of Open Access Journals (Sweden)

    Liang Tong

    2016-03-01

    Full Text Available A high thrust force bi-double-sided permanent magnet linear synchronous motor used in gantry-type five-axis machining center is designed and its performance was tested in this article. This motor is the subproject of Chinese National Science and Technology Major Project named as “development of domestic large thrust linear motor used in high-speed gantry-type five-axis machining center project” jointly participated by enterprises and universities. According to the requirement of the application environment and motor performance parameters, the linear motor’s basic dimensions, form of windings, and magnet arrangement are preliminarily specified through theoretical analysis and calculation. To verify the correctness of the result of the calculation, the finite element model of the motor is established. The static and dynamic characteristics of the motor are studied and analyzed through the finite element method, and the initial scheme is revised. The prototype of the motor is manufactured based on the final revised structure parameters, and the performance of the motor is fully tested using the evaluation platform for direct-drive motor component. Experimental test results meet the design requirements and show the effectiveness of design method and process.

  12. Effects of tyrosine kinase and phosphatase inhibitors on mitosis progression in synchronized tobacco BY-2 cells.

    Science.gov (United States)

    Sheremet, Ya A; Yemets, A I; Azmi, A; Vissenberg, K; Verbelen, J P; Blume, Ya B

    2012-01-01

    To test whether reversible tubulin phosphorylation plays any role in the process of plant mitosis the effects of inhibitors of tyrosine kinases, herbimycin A, genistein and tyrphostin AG 18, and of an inhibitor of tyrosine phosphatases, sodium orthovanadate, on microtubule organization and mitosis progression in a synchronized BY-2 culture has been investigated. It was found that treatment with inhibitors of tyrosine kinases of BY-2 cells at the G2/M transition did not lead to visible disturbances of mitotic microtubule structures, while it did reduce the frequency of their appearance. We assume that a decreased tyrosine phosphorylation level could alter the microtubule dynamic instability parameters during interphase/prophase transition. All types of tyrosine kinase inhibitors used caused a prophase delay: herbimycin A and genistein for 2 h, and tyrphostin AG18 for 1 h. Thereafter the peak of mitosis was displaced for 1 h by herbimycin A or genistein exposure, but after tyrphostin AG18 treatment the timing of the mitosis-peak was comparable to that in control cells. Enhancement of tyrosine phosphorylation induced by the tyrosine phosphatase inhibitor resulted in the opposite effect on BY-2 mitosis transition. Culture treatment with sodium orthovanadate during 1 h resulted in an accelerated start of the prophase and did not lead to the alteration in time of the mitotic index peak formation, as compared to control cells. We suppose that the reversible tyrosine phosphorylation can be involved in the regulation of interphase to M phase transition possibly through regulation of microtubule dynamics in plant cells.

  13. Bladder extramedullary plasmacytoma and synchronous bladder urothelial transitional cell carcinoma: A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Karan Wadhwa

    2011-02-01

    Full Text Available Karan Wadhwa, Raj Singh, Lemke Z SolomonDepartment of Urology, Queen Alexandra Hospital, Portsmouth, UKAbstract: A 69-year-old man presented with sudden onset of macroscopic hematuria. While an ultrasound of the bladder revealed a posterior bladder mass, subsequent flexible cystoscopy demonstrated only an area of irregular urothelium. Initial general anesthetic cytoscopy and biopsy revealed conventional G2/3 T1 TCC. Histology of a further formal resection of this irregular area revealed carcinoma-in-situ and population of atypical cells with enlarged nuclei, prominent nucleoli, and varying quantities of cytoplasm showing plasma cell features. The immunohistochemistry was consistent with a plasmacytoma. There must be a high index of suspicion when ultrasound demonstrates a mass not detected by flexible cystoscopy, and biopsies/resection are advised to exclude extramedullary plasmacytoma (EMP as the cause. EMP of the urinary bladder is a rare entity with only 21 cases reported in the literature. In this report we describe a further case of EMP of the bladder associated with synchronous transitional cell carcinoma (TCC of the urothelium. We also highlight the important histopathological findings and review the current literature to report the outcomes of existing approaches to management of this rare form of bladder cancer. We believe this to be the first case reported in which a patient presented concurrently with bladder EMP and urothelial TCC. EMPs are highly radiosensitive tumors and in the case of head/neck disease, survival at 10 years is in the order of 65% following radical radiotherapy. Given the paucity of reported cases of primary bladder EMP, the optimal treatment regime remains unclear. In keeping with other anatomical sites current treatment is based to the assumed benefit of radical radiotherapy and prognosis appears to be better in those with no evidence of systemic disease.Keywords: bladder cancer, extramedullary plasmacytoma

  14. Chromoendoscopy to detect early synchronous second primary esophageal carcinoma in patients with squamous cell carcinomas of the head and neck?

    Science.gov (United States)

    Komínek, Pavel; Vítek, Petr; Urban, Ondřej; Zeleník, Karol; Halamka, Magdaléna; Feltl, David; Cvek, Jakub; Matoušek, Petr

    2013-01-01

    Objective. To evaluate the use of flexible esophagoscopy and chromoendoscopy with Lugol's solution in the detection of early esophageal carcinomas (second primary carcinomas) in patients with squamous cell carcinoma of the head and neck (HNSCC). Methods. All patients with newly diagnosed HNSCC underwent office-based Lugol's chromoendoscopy. After flexible esophagoscopy with white light, 3.0% Lugol's iodine solution was sprayed over the entire esophageal mucosa. Areas with less-intense staining (LVLs) were evaluated and biopsies taken. Results. 132 patients with HNSCC were enrolled in this study. The most frequent primary tumors were oropharyngeal (49/132), tumors of the oral cavity (36/132), and larynx (35/132). The majority of subjects (107/132 patients, 81.1%) had advanced HNSCC carcinomas (stages III and IV). Multiple LVLs were discovered in 24 subjects (18.2%) and no LVLs in 108 (81.8%) subjects. Fifty-five LVL biopsy specimens were obtained and assessed. Squamous cell carcinomas were detected in two patients, peptic esophagitis in 11 patients, gastric heterotopic mucosa in two patients, hyperplasia in two patients, and low- and high-grade dysplasia in three patients. Conclusion. Although only two patients with synchronous primary carcinomas were found among the patients, esophagoscopy should be recommended after detection of HNSCC to exclude secondary esophageal carcinoma or dysplasia.

  15. Chromoendoscopy to Detect Early Synchronous Second Primary Esophageal Carcinoma in Patients with Squamous Cell Carcinomas of the Head and Neck?

    Directory of Open Access Journals (Sweden)

    Pavel Komínek

    2013-01-01

    Full Text Available Objective. To evaluate the use of flexible esophagoscopy and chromoendoscopy with Lugol’s solution in the detection of early esophageal carcinomas (second primary carcinomas in patients with squamous cell carcinoma of the head and neck (HNSCC. Methods. All patients with newly diagnosed HNSCC underwent office-based Lugol's chromoendoscopy. After flexible esophagoscopy with white light, 3.0% Lugol's iodine solution was sprayed over the entire esophageal mucosa. Areas with less-intense staining (LVLs were evaluated and biopsies taken. Results. 132 patients with HNSCC were enrolled in this study. The most frequent primary tumors were oropharyngeal (49/132, tumors of the oral cavity (36/132, and larynx (35/132. The majority of subjects (107/132 patients, 81.1% had advanced HNSCC carcinomas (stages III and IV. Multiple LVLs were discovered in 24 subjects (18.2% and no LVLs in 108 (81.8% subjects. Fifty-five LVL biopsy specimens were obtained and assessed. Squamous cell carcinomas were detected in two patients, peptic esophagitis in 11 patients, gastric heterotopic mucosa in two patients, hyperplasia in two patients, and low- and high-grade dysplasia in three patients. Conclusion. Although only two patients with synchronous primary carcinomas were found among the patients, esophagoscopy should be recommended after detection of HNSCC to exclude secondary esophageal carcinoma or dysplasia.

  16. Synchronous fire activity in the tropical high Andes: an indication of regional climate forcing.

    Science.gov (United States)

    Román-Cuesta, R M; Carmona-Moreno, C; Lizcano, G; New, M; Silman, M; Knoke, T; Malhi, Y; Oliveras, I; Asbjornsen, H; Vuille, M

    2014-06-01

    Global climate models suggest enhanced warming of the tropical mid and upper troposphere, with larger temperature rise rates at higher elevations. Changes in fire activity are amongst the most significant ecological consequences of rising temperatures and changing hydrological properties in mountainous ecosystems, and there is a global evidence of increased fire activity with elevation. Whilst fire research has become popular in the tropical lowlands, much less is known of the tropical high Andean region (>2000 masl, from Colombia to Bolivia). This study examines fire trends in the high Andes for three ecosystems, the Puna, the Paramo and the Yungas, for the period 1982-2006. We pose three questions: (i) is there an increased fire response with elevation? (ii) does the El Niño- Southern Oscillation control fire activity in this region? (iii) are the observed fire trends human driven (e.g., human practices and their effects on fuel build-up) or climate driven? We did not find evidence of increased fire activity with elevation but, instead, a quasicyclic and synchronous fire response in Ecuador, Peru and Bolivia, suggesting the influence of high-frequency climate forcing on fire responses on a subcontinental scale, in the high Andes. ENSO variability did not show a significant relation to fire activity for these three countries, partly because ENSO variability did not significantly relate to precipitation extremes, although it strongly did to temperature extremes. Whilst ENSO did not individually lead the observed regional fire trends, our results suggest a climate influence on fire activity, mainly through a sawtooth pattern of precipitation (increased rainfall before fire-peak seasons (t-1) followed by drought spells and unusual low temperatures (t0), which is particularly common where fire is carried by low fuel loads (e.g., grasslands and fine fuel). This climatic sawtooth appeared as the main driver of fire trends, above local human influences and fuel build

  17. Synchronous sporadic medullary carcinoma of the thyroid and small-cell carcinoma of lung: A rare entity

    Directory of Open Access Journals (Sweden)

    Manigreeva Krishnatreya

    2013-01-01

    Full Text Available Synchronous medullary carcinoma of the thyroid and small-cell carcinoma of the lung is a rare phenomenon and both these tumors are characterized by poor treatment outcome and prognosis. A 45-year-old woman presented with a progressive swelling in front and side of the neck of 3-month duration without any pulmonary symptoms. The tumor of the lung was an incidental finding on routine chest radiological examination. The diagnosis of synchronous primary cancers of the thyroid and the lung were made after cytopathological examination of both the lesions. We report here a case of loco-regional sporadic medullary carcinoma of the thyroid associated with limited stage small-cell carcinoma of the lung and its therapeutic challenges.

  18. Endolaparoscopic left hemicolectomy and synchronous laparoscopic radical nephrectomy for obstructive carcinoma of the descending colon and renal cell carcinoma.

    Science.gov (United States)

    Ng, Simon S M; Yiu, Raymond Y C; Li, Jimmy C M; Chan, Chi Kwok; Ng, Chi Fai; Lau, James Y W

    2006-06-01

    Colorectal self-expandable metal stents (SEMS) have been used successfully as preoperative bridges to surgery for obstructive left-sided colorectal carcinoma. Endoscopic relief of the obstruction allows for full bowel preparation and accurate preoperative staging. A laparoscopic approach, considered by many to be contraindicated in the presence of obstruction, becomes feasible after endoscopic decompression. We present a case of obstructive carcinoma of the descending colon successfully treated with endoscopic decompression with colorectal SEMS. Subsequent staging with computed tomography revealed a renal cell carcinoma in the left kidney. Synchronous laparoscopic resection of the two carcinomas was performed, with no morbidity. To the best of our knowledge, this is the first report of endolaparoscopic left hemicolectomy and synchronous laparoscopic radical nephrectomy for obstructive carcinoma of the descending colon and renal cell carcinoma. The advantages of colorectal SEMS and the endolaparoscopic approach in managing obstructive colorectal carcinoma are discussed.

  19. Assessment of cell cycle phase-specific effects of zerumbone on mitotically synchronous surface cultures of Physarum polycephalum.

    Science.gov (United States)

    Rajan, Iyyappan; Rabindran, Remitha; Nithya, N; Lakshmipriya, T; Jayasree, P R; Kumar, P R M

    2014-07-01

    Zerumbone, a natural cyclic sesquiterpene, has been the focus of recent research as it has been found to exhibit selective toxicity towards cancer cells compared to normal cells. Studies on the cell cycle phase-specific effects of this interesting compound, however, remain sparse. Hence, concentration and time-dependent effects of zerumbone were evaluated employing a suitable model system, the naturally synchronous surface cultures of Physarum polycephalum. Zerumbone treatment in S, early, and late G2 phases resulted in G2 arrest. Early G2 phase exhibited the highest sensitivity (P polycephalum.

  20. Effect of synchronization of donor cells in early G1-phase using shake-off method on developmental potential of somatic cell nuclear transfer embryos in cattle.

    Science.gov (United States)

    Goto, Yuji; Hirayama, Muneyuki; Takeda, Kazuya; Tukamoto, Nobuyuki; Sakata, Osamu; Kaeriyama, Hiroshi; Geshi, Masaya

    2013-08-01

    In this study, we compared the developmental ability of somatic cell nuclear transfer (SCNT) embryos reconstructed with three bovine somatic cells that had been synchronized in G0-phase (G0-SCNT group) or early G1-phase (eG1-SCNT group). Furthermore, we investigated the production efficiency of cloned offspring for NT embryos derived from these donor cells. The G0-phase and eG1-phase cells were synchronized, respectively, using serum starvation and antimitotic reagent treatment combined with shaking of the plate containing the cells (shake-off method). The fusion rate in the G0-SCNT groups (64.2 ± 1.8%) was significantly higher than that of eG1-SCNT groups (39.2 ± 1.9%) (P cells in eG1-phase using the shake-off method improved the overall production efficiency of the clone offspring per transferred embryo.

  1. Development of High-Thrust and Double-Sided Linear Synchronous Motor Module For Liquid Crystal Display Equipment

    Institute of Scientific and Technical Information of China (English)

    Myung-jin; CHUNG; Sang-yeon; HWANG

    2010-01-01

    <正>Recently,there is an increasing requirement for controlling linear motion up to a few hundred of millimeter strokes in the area of the liquid crystal display(LCD) production equipment.The requirements of the motion system for LCD production equipment are high acceleration and high velocity with positioning accuracy.To satisfy these requirements,it has to be designed with the high-thrust force and low velocity ripple.In this work, high-thrust and double-sided linear synchronous motor (LSM)module is proposed and the developed high-thrust and double-sided LSM module is verified by performance test.

  2. Cryptic diversity, high host specificity and reproductive synchronization in army ant-associated Vatesus beetles.

    Science.gov (United States)

    von Beeren, Christoph; Maruyama, Munetoshi; Kronauer, Daniel J C

    2016-02-01

    Army ants and their arthropod symbionts represent one of the most species-rich animal associations on Earth, and constitute a fascinating example of diverse host-symbiont interaction networks. However, despite decades of research, our knowledge of army ant symbionts remains fragmentary due to taxonomic ambiguity and the inability to study army ants in the laboratory. Here, we present an integrative approach that allows us to reliably determine species boundaries, assess biodiversity, match different developmental stages and sexes, and to study the life cycles of army ant symbionts. This approach is based on a combination of community sampling, DNA barcoding, morphology and physiology. As a test case, we applied this approach to the staphylinid beetle genus Vatesus and its different Eciton army ant host species at La Selva Biological Station, Costa Rica. DNA barcoding led to the discovery of cryptic biodiversity and, in combination with extensive community sampling, revealed strict host partitioning with no overlap in host range. Using DNA barcoding, we were also able to match the larval stages of all focal Vatesus species. In combination with studies of female reproductive physiology, this allowed us to reconstruct almost the complete life cycles of the different beetle species. We show that Vatesus beetles are highly adapted to the symbiosis with army ants, in that their reproduction and larval development are synchronized with the stereotypical reproductive and behavioural cycles of their host colonies. Our approach can now be used to study army ant-symbiont communities more broadly, and to obtain novel insights into co-evolutionary and ecological dynamics in species-rich host-symbiont systems.

  3. Considering High School Students’ Experience in Asynchronous and Synchronous Distance Learning Environments: QoE Prediction Model

    Directory of Open Access Journals (Sweden)

    Toni Malinovski

    2014-09-01

    Full Text Available Early identification of relevant factors that influence students’ experiences is vitally important to the educational process since they play an important role in learning outcomes. The purpose of this study is to determine underlying constructs that predict high school students’ subjective experience and quality expectations during asynchronous and synchronous distance education activities, in a form of quality of experience (QoE. One hundred and fifty-eight students from different high schools participated in several asynchronous and synchronous learning sessions and provided relevant feedback with comparable opinions regarding different conditions. Structural equation modeling was used as an analytical procedure during data analysis which led to a QoE prediction model that identified relevant factors influencing students’ subjective QoE. The results demonstrated no significant difference related to students’ behavior and expectations during both distance education methods. Additionally, this study revealed that students’ QoE in any situation was mainly determined by motivational factors (intrinsic and extrinsic and moderately influenced by ease of use during synchronous or quality of content during asynchronous activities. We also found moderate support between technical performance and students’ QoE in both learning environments. However, opposed to existing technology acceptance models that stress the importance of attitude towards use, high school students’ attitude failed to predict their QoE.

  4. Neocortical synchronization

    Science.gov (United States)

    Timofeev, Igor; Bazhenov, Maksim; Seigneur, Joseé; Sejnowski, Terrence

    2011-01-01

    Summary Neuronal synchronization occurs when two or more neuronal events are coordinated across time. Local synchronization produces field potentials. Long-range synchronization between distant brain sites contributes to the electroencephalogram. Neuronal synchronization depends on synaptic (chemical/electrical), ephaptic, and extracellular interactions. For an expanded treatment of this topic see Jasper’s Basic Mechanisms of the Epilepsies, Fourth Edition (Noebels JL, Avoli M, Rogawski MA, Olsen RW, Delgado-Escueta AV, eds) published by Oxford University Press (available on the National Library of Medicine Bookshelf [NCBI] at www.ncbi.nlm.nih.gov/books). PMID:24850952

  5. A Synchronous Pancreatic Metastasis from Renal Clear Cell Carcinoma, with Unusual CT Characteristics, Completely Regressed after Therapy with Sunitinib

    Directory of Open Access Journals (Sweden)

    Salvatore Lauro

    2014-01-01

    Full Text Available We present a case report of a 75-years-old woman affected by renal clear cell carcinoma with a synchronous pancreatic metastasis and a metachronous lung metastasis. This case has two peculiarities. First the pancreatic metastasis was treated just with medical therapy, that is, Sunitinib, instead of the surgical therapy that is mostly considered. Secondly, the pancreatic lesion showed different characteristics on the computed tomography scan compared to the usual pancreatic metastases from renal clear cell carcinoma. The pancreatic metastasis totally regressed after medical treatment and nowadays, four years after the diagnosis, the patient is disease-free.

  6. High-Yield Superovulation in Adult Mice by Anti-Inhibin Serum Treatment Combined with Estrous Cycle Synchronization.

    Science.gov (United States)

    Hasegawa, Ayumi; Mochida, Keiji; Inoue, Hiroki; Noda, Yoshihiro; Endo, Tamao; Watanabe, Gen; Ogura, Atsuo

    2016-01-01

    Producing many mature oocytes is of great importance for assisted reproductive technologies. In mice, superovulation by consecutive injections of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) has been the gold standard for oocyte collection. However, the yield of mature oocytes by this regimen can fluctuate according to the stage of the estrous cycle, strain, and age. Therefore, our objective was to develop a high-yield superovulation protocol to collect higher numbers of oocytes from adult female mice of different strains and ages. First, we aimed to synchronize the estrous cycle using C57BL/6 (B6) female mice. Most (93%) were synchronized to metestrus after two daily injections of progesterone. Second, we found that with the injection of anti-inhibin serum (AIS) instead of eCG, the mean number of ovulated oocytes almost doubled (21 vs. 41 per mouse). Third, by combining estrous cycle synchronization with two AIS injections, we obtained 62 oocytes per mouse, about three times that with the eCG-hCG protocol. Importantly, this approach increased the proportion of mice that ovulated >25 oocytes from about 40% (eCG-hCG) to 90%. The same protocol was also effective in other inbred (BALB/cA), outbred (ICR), and hybrid (B6D2F1) strains. In addition, B6 female mice aged over 1 yr ovulated 1.8-fold more oocytes by this protocol. Thus, estrous cycle synchronization followed by AIS-hCG yielded a broadly applicable, highly efficient superovulation. This protocol should promote the effective use of invaluable female mouse strains and decrease the numbers of animals euthanized. © 2016 by the Society for the Study of Reproduction, Inc.

  7. Renal Cell Carcinoma of the Kidney with Synchronous Ipsilateral Transitional Cell Carcinoma of the Renal Pelvis

    Directory of Open Access Journals (Sweden)

    Dogan Atilgan

    2013-01-01

    Full Text Available A 73-year-old man was admitted to our clinic with flank pain and gross macroscopic hematuria. Radiologic examination revealed a solid mass in the left kidney and additionally another mass in the ureteropelvic junction of the same kidney with severe hydronephrosis. Left nephroureterectomy with bladder cuff removel was performed, and histopathological evolution showed a Fuhrman grade 3 clear cell type RCC with low-grade TCC of the pelvis.

  8. New synchronization method for Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Mwangi Jonathan M

    2010-06-01

    Full Text Available Abstract Background Plasmodium falciparum is usually asynchronous during in vitro culture. Although various synchronization methods are available, they are not able to narrow the range of ages of parasites. A newly developed method is described that allows synchronization of parasites to produce cultures with an age range as low as 30 minutes. Methods Trophozoites and schizonts are enriched using Plasmion. The enriched late stage parasites are immobilized as a monolayer onto plastic Petri dishes using concanavalin A. Uninfected erythrocytes are placed onto the monolayer for a limited time period, during which time schizonts on the monolayer rupture and the released merozoites invade the fresh erythrocytes. The overlay is then taken off into a culture flask, resulting in a highly synchronized population of parasites. Results Plasmion treatment results in a 10- to 13-fold enrichment of late stage parasites. The monolayer method results in highly synchronized cultures of parasites where invasion has occurred within a very limited time window, which can be as low as 30 minutes. The method is simple, requiring no specialized equipment and relatively cheap reagents. Conclusions The new method for parasite synchronization results in highly synchronized populations of parasites, which will be useful for studies of the parasite asexual cell cycle.

  9. Transcriptome and proteome dynamics of a light-dark synchronized bacterial cell cycle.

    Directory of Open Access Journals (Sweden)

    Jacob R Waldbauer

    Full Text Available BACKGROUND: Growth of the ocean's most abundant primary producer, the cyanobacterium Prochlorococcus, is tightly synchronized to the natural 24-hour light-dark cycle. We sought to quantify the relationship between transcriptome and proteome dynamics that underlie this obligate photoautotroph's highly choreographed response to the daily oscillation in energy supply. METHODOLOGY/PRINCIPAL FINDINGS: Using RNA-sequencing transcriptomics and mass spectrometry-based quantitative proteomics, we measured timecourses of paired mRNA-protein abundances for 312 genes every 2 hours over a light-dark cycle. These temporal expression patterns reveal strong oscillations in transcript abundance that are broadly damped at the protein level, with mRNA levels varying on average 2.3 times more than the corresponding protein. The single strongest observed protein-level oscillation is in a ribonucleotide reductase, which may reflect a defense strategy against phage infection. The peak in abundance of most proteins also lags that of their transcript by 2-8 hours, and the two are completely antiphase for some genes. While abundant antisense RNA was detected, it apparently does not account for the observed divergences between expression levels. The redirection of flux through central carbon metabolism from daytime carbon fixation to nighttime respiration is associated with quite small changes in relative enzyme abundances. CONCLUSIONS/SIGNIFICANCE: Our results indicate that expression responses to periodic stimuli that are common in natural ecosystems (such as the diel cycle can diverge significantly between the mRNA and protein levels. Protein expression patterns that are distinct from those of cognate mRNA have implications for the interpretation of transcriptome and metatranscriptome data in terms of cellular metabolism and its biogeochemical impact.

  10. Practical experience with IEEE 1588 high precision time synchronization in electrical substation based on IEC 61850 process bus

    Energy Technology Data Exchange (ETDEWEB)

    Moore, R.; Goraj, M.J.; McGhee, J. [RuggedCom Inc., Concord, ON (Canada)

    2010-07-01

    This paper discussed a time synchronization and dynamic multicast filtering procedure conducted on an IEC 61850 process bus. The Institute of Electrical and Electronic (IEEE) 1588 time synchronization and dynamic multicast filtering procedure was conducted at a substation equipped with non-conventional instrument transformers (NCIT) and intelligent circuit breakers. The process bus interconnected IEDs within a bay that included a real time sampled value (SV) measurement system. The system was designed to reduce the use of copper wiring and to eliminate high energy signal processes. Digitized sampled measured values were sent from the electronic instrument transformers to protect and control relays. A merging unit was used to enable the transmission of the digitized current and voltage measurements across an ethernet network. Two sampling rates were supplied for power system monitoring and protection applications. The merging units continuously sent sampling values of current and voltages acquired from primary equipment. Precision time protocol systems were discussed, and issues related to time synchronization were reviewed. A network topology was provided. 4 refs., 4 figs.

  11. Synchronous pumping of picosecond dye laser using high efficiency second harmonic generation from optical fibres

    Science.gov (United States)

    Lawandy, N. M.; Bernardin, J. P.; Macdonald, R. L.; Demouchy, G.

    1991-01-01

    The stable operation of a mode-locked dye laser synchronously pumped by the second harmonic of an Nd:YAG laser produced in an Nd codoped germanosilicate optical fiber is reported. The optical fiber preparation technique, which results in a second harmonic conversion efficiency of 2 percent, is described. This optical fiber SHG conversion efficiency is the highest reported to date using a continuous-wave mode-locked laser.

  12. Time-resolved studies at PETRA III with a highly repetitive synchronized laser system

    Energy Technology Data Exchange (ETDEWEB)

    Schlie, Mortiz

    2013-09-15

    Atomic and molecular processes can nowadays be directly followed in the time domain. This is a core technique for a better understanding of the involved fundamental physics, thus auguring new applications in the future as well. Usually the so-called pump-probe technique making use of two synchronized ultrashort light pulses is utilized to obtain this time-resolved data. In this work, the development and characterization of a synchronization system enabling such pump-probe studies at the storage ring PETRA III in combination with an external, then synchronized fs-laser system is described. The synchronization is based on an extended PLL approach with three interconnected feedback loops allowing to monitor short-time losses of the lock and thus prevent them. This way, the jitter between the laser PHAROS and the PETRA III reference signal is reduced to {sigma} <5 ps. Thus the system allows to conduct experiments at a repetition rate of 130 kHz with a temporal resolution limited only by the X-ray pulse length. A major emphasis in the fundamental introductory chapters is an intuitive explanation of the basic principles of phase locked loops and the different aspects of phase noise to allow a deeper understanding of the synchronization. Furthermore, first pump-probe experiments conducted at different beamlines at PETRA III are presented, demonstrating the usability of the laser system in a scientific environment as well. In first characterizing experiments the pulse duration of PETRA III X-ray pulses has been measured to be 90 ps FWHM. In particular, there have been time resolved X-ray absorption spectroscopy experiments on Gaq3 and Znq2 conducted at beamline P11. First results show dynamics of the electronic excitation on the timescale of a few hundred pico seconds up to a few nano seconds and provide a basic understanding for further research on those molecules. For Gaq3 this data is analyzed in detail and compared with visible fluorescence measurements suggesting at

  13. Synchronizing atomic force microscopy force mode and fluorescence microscopy in real time for immune cell stimulation and activation studies

    Energy Technology Data Exchange (ETDEWEB)

    Cazaux, Séverine; Sadoun, Anaïs; Biarnes-Pelicot, Martine; Martinez, Manuel; Obeid, Sameh [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Bongrand, Pierre [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); APHM, Hôpital de la Conception, Laboratoire d’Immunologie, Marseille F-13385 (France); Limozin, Laurent [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Puech, Pierre-Henri, E-mail: pierre-henri.puech@inserm.fr [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France)

    2016-01-15

    A method is presented for combining atomic force microscopy (AFM) force mode and fluorescence microscopy in order to (a) mechanically stimulate immune cells while recording the subsequent activation under the form of calcium pulses, and (b) observe the mechanical response of a cell upon photoactivation of a small G protein, namely Rac. Using commercial set-ups and a robust signal coupling the fluorescence excitation light and the cantilever bending, the applied force and activation signals were very easily synchronized. This approach allows to control the entire mechanical history of a single cell up to its activation and response down to a few hundreds of milliseconds, and can be extended with very minimal adaptations to other cellular systems where mechanotransduction is studied, using either purely mechanical stimuli or via a surface bound specific ligand. - Highlights: • A signal coupling AFM and fluorescence microscopy was characterized for soft cantilevers. • It can be used as an intrinsic timer to synchronize images and forces. • Mechanical stimulation of single immune cells while recording calcium fluxes was detailed. • Light-induced mechanical modifications of lymphocytes using a PA-Rac protein were demonstrated. • The precautions and limitations of use of this effect were presented.

  14. Synchronizing Progression of Schizosaccharomyces pombe Cells from Prophase through Mitosis and into S Phase with nda3-KM311 Arrest Release.

    Science.gov (United States)

    Hagan, Iain M; Grallert, Agnes; Simanis, Viesturs

    2016-08-01

    Here, we describe how the rapid reversibility of the nda3-KM311 cold-sensitive β-tubulin mutation was optimized by Mitsuhiro Yanagida's laboratory to synchronize mitotic progression in an entire cell population. The inability to form microtubules following the loss of β-tubulin function at 20°C triggers the spindle assembly checkpoint, which arrests mitotic progression. Restoration of β-tubulin function by rewarming to 30°C (or higher) releases the arrest, generating a highly synchronous progression through mitosis. The viability of nda3-KM311 strains at 30°C makes it feasible to generate double mutants between nda3-KM311 and any temperature-sensitive mutant that can also grow at 30°C. These double mutants can be used in reciprocal shift analyses, in which cold-induced early mitotic arrest is relieved by a shift to 36°C, which then inactivates the product of the second mutant gene. The addition of microtubule depolymerizing drugs before the return to 36°C will maintain checkpoint signaling at 36°C transiently, permitting analysis of the impact of temperature-sensitive mutations on checkpoint function. Silencing the checkpoint of nda3-KM311-arrested cells at 20°C through chemical inhibition of aurora kinase is a powerful way to study checkpoint recovery pathways and mitotic exit without anaphase.

  15. Synchronous luminescence spectroscopic characterization of blood elements of normal and patients with cervical cancer

    Science.gov (United States)

    Muthuvelu, K.; Shanmugam, Sivabalan; Koteeswaran, Dornadula; Srinivasan, S.; Venkatesan, P.; Aruna, Prakasarao; Ganesan, Singaravelu

    2011-03-01

    In this study the diagnostic potential of synchronous luminescence spectroscopy (SLS) technique for the characterization of normal and different pathological condition of cervix viz., moderately differentiated squamous cell carcinoma (MDSCC), poorly differentiated squamous cell carcinoma (PDSCC) and well differentiated squamous cell carcinoma (WDSSC). Synchronous fluorescence spectra were measured for 70 abnormal cases and 30 normal subjects. Characteristic, highly resolved peaks and significant spectral differences between normal and MDSCC, PDSCC and WDSCC cervical blood formed elements were obtained. The synchronous luminescence spectra of formed elements of normal and abnormal cervical cancer patients were subjected to statistical analysis. Synchronous luminescence spectroscopy provides 90% sensitivity and 92.6% specificity.

  16. Anandamide drives cell cycle progression through CB1 receptors in a rat model of synchronized liver regeneration.

    Science.gov (United States)

    Pisanti, Simona; Picardi, Paola; Pallottini, Valentina; Martini, Chiara; Petrosino, Stefania; Proto, Maria Chiara; Vitale, Mario; Laezza, Chiara; Gazzerro, Patrizia; Di Marzo, Vincenzo; Bifulco, Maurizio

    2015-12-01

    The endocannabinoid system, through cannabinoid receptor signaling by endocannabinoids, is involved in a wide range of functions and physiopathological conditions. To date, very little is known concerning the role of the endocannabinoids in the control and regulation of cell proliferation. An anti-proliferative action of CB1 signaling blockade in neurogenesis and angiogenesis argues in favor of proliferation-promoting functions of endocannabinoids through CB1 receptors when pro-growth signals are present. Furthermore, liver regeneration, a useful in vivo model of synchronized cell proliferation, is characterized by a peak of anandamide that elicits through CB1 receptor, the expression of critical mitosis genes. The aim of this study was to focus on the timing of endocannabinoid signaling changes during the different phases of the cell cycle, exploiting the rat liver regeneration model following partial hepatectomy, the most useful to study synchronized cell cycle in vivo. Hepatic regeneration led to increased levels of anandamide and endocannabinoid-like molecules oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the G1 phase of the cell cycle, with a concomitant increase in CB1 mRNA levels, whose protein expression peaked later during the S phase. Blocking of CB1 receptor with a low dose of the selective antagonist/inverse agonist SR141716 (0.7 mg/kg/dose) affected cell cycle progression reducing the expression of PCNA, and through the inhibition of pERK and pSTAT3 pathways. These results support the notion that the signaling mediated by anandamide through CB1 receptor may be important for the entry and progression of cells into the cell cycle and hence for their proliferation under mitogenic signals.

  17. Renal cell carcinoma and synchronous thyroid metastasis with neoplastic thrombosis of the internal jugular vein: report of a case.

    Science.gov (United States)

    Matei, Deliu-Victor; Brescia, Antonio; Nordio, Andrea; Spinelli, Matteo Giulio; Melegari, Sara; Cozzi, Gabriele; Andrioli, Massimiliano; Salvatori, Pietro

    2011-12-01

    A case of thyroid metastasis of a renal clear cell carcinoma is presented. The fine-needle aspiration cytology pointed out the primary tumor origin. The patient underwent robot-assisted radical nephrectomy and contextual thyroidectomy. During the operative procedure, a neoplastic thrombus extending from the thyroid metastasis and protruding into the internal jugular vein was found. As a result, thrombectomy and ligation of the internal jugular vein were required. In cases of single synchronous thyroid metastases form RCC, radical surgery should be advisable. Robotic approach allows to associate major surgery procedures, as nephrectomy, with radical metastasectomy.

  18. High Red Blood Cell Count

    Science.gov (United States)

    Symptoms High red blood cell count By Mayo Clinic Staff A high red blood cell count is an increase in oxygen-carrying cells in your bloodstream. Red blood cells transport oxygen from your lungs to tissues throughout ...

  19. Development of A Super High Speed Permanent Magnet Synchronous Motor (PMSM Controller and Analysis of The Experimental Results

    Directory of Open Access Journals (Sweden)

    Limei Zhao

    2005-02-01

    Full Text Available This paper presents the design and implementation of a DSP-based controller for a super high-speed (>80,000 rpm permanent magnet synchronous motor (PMSM. The PMSM is a key component of the centrifugal compressor drive of a reverse Brayton cryocooler that is currently under development for NASA and Florida Solar Energy Center. The design of the PMSM open-loop control is presented. Experimental results with open-loop control schemes are presented. System optimization and analysis are also illustrated. They verify the effectiveness of the controller design and the optimization scheme.

  20. High fidelity simulation of non-synchronous vibration for aircraft engine fan/compressor

    Science.gov (United States)

    Im, Hong-Sik

    The objectives of this research are to develop a high fidelity simulation methodology for turbomachinery aeromechanical problems and to investigate the mechanism of non-synchronous vibration (NSV) of an aircraft engine axial compressor. A fully conservative rotor/stator sliding technique is developed to accurately capture the unsteadiness and interaction between adjacent blade rows. Phase lag boundary conditions (BC) based on the time shift (direct store) method and the Fourier series phase lag BC are implemented to take into account the effect of phase difference for a sector of annulus simulation. To resolve the nonlinear interaction between flow and vibrating blade structure, a fully coupled fluid-structure interaction (FSI) procedure that solves the structural modal equations and time accurate Navier-Stokes equations simultaneously is adopted. An advanced mesh deformation method that generates the blade tip block mesh moving with the blade displacement is developed to ensure the mesh quality. An efficient and low diffusion E-CUSP (LDE) scheme as a Riemann solver designed to minimize numerical dissipation is used with an improved hybrid RANS/LES turbulence strategy, delayed detached eddy simulation (DDES). High order accuracy (3rd and 5th order) weighted essentially non-oscillatory (WENO) schemes for inviscid flux and a conservative 2nd and 4th order viscous flux differencing are employed. Extensive validations are conducted to demonstrate high accuracy and robustness of the high fidelity FSI simulation methodology. The validated cases include: (1) DDES of NACA 0012 airfoil at high angle of attack with massive separation. The DDES accurately predicts the drag whereas the URANS model significantly over predicts the drag. (2) The AGARD Wing 445.6 flutter boundary is accurately predicted including the point at supersonic incoming flow. (3) NASA Rotor 67 validation for steady state speed line and radial profiles at peak efficiency point and near stall point. The

  1. Performance Analysis of Trench Power MOSFETs in High-Frequency Synchronous Buck Converter Applications

    Directory of Open Access Journals (Sweden)

    Yali Xiong

    2008-01-01

    Full Text Available This paper investigates the performance perspectives and theoretical limitations of trench power MOSFETs in synchronous rectifier buck converters operating in the MHz frequency range. Several trench MOSFET technologies are studied using a mixed-mode device/circuit modeling approach. Individual power loss contributions from the control and synchronous MOSFETs, and their dependence on switching frequency between 500 kHz and 5 MHz are discussed in detail. It is observed that the conduction loss contribution decreases from 40% to 4% while the switching loss contribution increases from 60% to 96% as the switching frequency increases from 500 KHz to 5 MHz. Beyond 1 MHz frequency there is no obvious benefit to increase the die size of either SyncFET or CtrlFET. The RDS(ON×QG figure of merit (FOM still correlates well to the overall converter efficiency in the MHz frequency range. The efficiency of the hard switching buck topology is limited to 80% at 2 MHz and 65% at 5 MHz even with the most advanced trench MOSFET technologies.

  2. Gastric marginal zone lymphoma of mucosa-associated lymphoid tissue and signet ring cell carcinoma, synchronous collision tumour of the stomach: a case report.

    Science.gov (United States)

    George, Smiley Annie; Junaid, T A

    2014-01-01

    To report a rare case of synchronous marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) signet ring cell carcinoma occurring as a collision tumour in the stomach. A 53-year-old man was diagnosed initially with signet ring cell carcinoma of the stomach. The microscopy of the subsequent total gastrectomy revealed a collision tumour of MALT lymphoma and signet ring cell carcinoma associated with Helicobacter pylori gastritis. This case highlighted the importance of a careful evaluation of the accompanying lymphoid population in the biopsy samples of gastric adenocarcinoma and underlined the need for multiple endoscopic biopsies to detect these rare synchronous tumours. © 2013 S. Karger AG, Basel.

  3. Optimized High Frequency Signal Injection Based Permanent Magnet Synchronous Motor Rotor Position Estimation Applied to Washing Machines

    Directory of Open Access Journals (Sweden)

    Olfa B.H.B. Kechiche

    2011-01-01

    Full Text Available Problem statement: This study investigates a novel optimized scheme of a High Frequency Signal Injection (HFSI based sensorless technique in order to carry out a precise and robust rotor position error estimation of a Permanent Magnet Synchronous Motor (PMSM drive designed for washing machines. The study is carried out for standstill condition, where precise position information is required for this application. Approach: In order to get rotor position error information, a PMSM high frequency model is considered in the estimated rotor reference frame (d,q. Then, the impact of the HFSI technique parameters choice on the PMSM rotor position estimation performance is studied and experimentally tested, under various injection conditions. Results: The experimental results show that the amplitude of the high frequency current, resulting from injection, is not significant to carry out high performance rotor position estimation. In order to improve rotor position estimation performance and robustness, a modified demodulation of the high frequency current resulting from injection is proposed by using a high pass filter amplifier applied to PMSM measured currents. The novel proposed rotor position error extraction scheme is implemented on a dsPIC30F6010A and is experimentally validated on a 1kW washing salient pole PMSM. Conclusion: This study presents an improved high frequency voltage injection based sensorless control for Permanent Magnet Synchronous Motor (PMSM designed for washing machines. The optimal parameters choice of the HFSI technique and the use of a high pass filter amplifier have allowed to take the most of the high frequency injected signal for extracting the rotor position error at standstill, compared to a conventional scheme.

  4. Circadian and Ultradian Rhythms of Free Glucocorticoid Hormone Are Highly Synchronized between the Blood, the Subcutaneous Tissue, and the Brain

    Science.gov (United States)

    Qian, Xiaoxiao; Droste, Susanne K.; Lightman, Stafford L.; Reul, Johannes M. H. M.

    2012-01-01

    Total glucocorticoid hormone levels in plasma of various species, including humans, follow a circadian rhythm that is made up from an underlying series of hormone pulses. In blood most of the glucocorticoid is bound to corticosteroid-binding globulin and albumin, resulting in low levels of free hormone. Although only the free fraction is biologically active, surprisingly little is known about the rhythms of free glucocorticoid hormones. We used single-probe microdialysis to measure directly the free corticosterone levels in the blood of freely behaving rats. Free corticosterone in the blood shows a distinct circadian and ultradian rhythm with a pulse frequency of approximately one pulse per hour together with an increase in hormone levels and pulse height toward the active phase of the light/dark cycle. Similar rhythms were also evident in the subcutaneous tissue, demonstrating that free corticosterone rhythms are transferred from the blood into peripheral target tissues. Furthermore, in a dual-probe microdialysis study, we demonstrated that the circadian and ultradian rhythms of free corticosterone in the blood and the subcutaneous tissue were highly synchronized. Moreover, free corticosterone rhythms were also synchronous between the blood and the hippocampus. These data demonstrate for the first time an ultradian rhythm of free corticosterone in the blood that translates into synchronized rhythms of free glucocorticoid hormone in peripheral and central tissues. The maintenance of ultradian rhythms across tissue barriers in both the periphery and the brain has important implications for research into aberrant biological rhythms in disease and for the development of improved protocols for glucocorticoid therapy. PMID:22822164

  5. The effect of estrus synchronization treatments on somatic cell count of transitional-anestrus Awassi ewes' milk.

    Science.gov (United States)

    Talafha, A Q; Lafi, S Q; Ababneh, M M

    2009-02-01

    Fifty-three transitional-anestrus Awassi ewes, randomly assigned to three groups: fluorogestone acetate (FGA, n = 18), FGA-Prostaglandin (FGA-PGF, n = 18) and control (n = 17), were used to examine the effect of estrus synchronization protocols and steroid hormones concentrations on milk somatic cell count (SCC). Intravaginal FGA sponge was inserted for 13 days and 600 IU equine chorionic gonadotropin was administered for ewes of FGA and FGA-PGF groups at the time of sponge removal (day 0). In addition, 10 mg was administered to ewes of FGA-PGF group on day 0. Blood and milk samples were collected from all ewes on days -13, -6, 0, 1, 2, 7 and 14. Estradiol had significant positive correlation with the SCC during the periods of sponge insertion (P = 0.015, r = 0.235) and within two days (P = 0.063 r = 0.23) after sponge removal with no correlation with SCC of both udder halves during the luteal phase. Progesterone concentrations, on the other hand, had a significant positive correlation (P synchronization values. In conclusion, sheep milk SCC is affected significantly with induction of estrus and steroid hormones concentrations. However, peak SCC recorded during estrus was far below the upper limit of the current standard for normal milk. With the current standards for SCC of 1,000,000/ml as legal limit for abnormal milk control programs in sheep, estrus synchronization programs and the estrus status should not be considered when bulk-tank milk SCC is being investigated, but should be considered during the process of setting new standards.

  6. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy

    Science.gov (United States)

    Muir, Ryan D.; Sullivan, Shane Z.; Oglesbee, Robert A.; Simpson, Garth J.

    2014-01-01

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content. PMID:24689588

  7. Synchronous digitization for high dynamic range lock-in amplification in beam-scanning microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Muir, Ryan D.; Sullivan, Shane Z.; Oglesbee, Robert A.; Simpson, Garth J., E-mail: gsimpson@purdue.edu [Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907 (United States)

    2014-03-15

    Digital lock-in amplification (LIA) with synchronous digitization (SD) is shown to provide significant signal to noise (S/N) and linear dynamic range advantages in beam-scanning microscopy measurements using pulsed laser sources. Direct comparisons between SD-LIA and conventional LIA in homodyne second harmonic generation measurements resulted in S/N enhancements consistent with theoretical models. SD-LIA provided notably larger S/N enhancements in the limit of low light intensities, through the smooth transition between photon counting and signal averaging developed in previous work. Rapid beam scanning instrumentation with up to video rate acquisition speeds minimized photo-induced sample damage. The corresponding increased allowance for higher laser power without sample damage is advantageous for increasing the observed signal content.

  8. Decoding Network Structure in On-Chip Integrated Flow Cells with Synchronization of Electrochemical Oscillators

    Science.gov (United States)

    Jia, Yanxin; Kiss, István Z.

    2017-04-01

    The analysis of network interactions among dynamical units and the impact of the coupling on self-organized structures is a challenging task with implications in many biological and engineered systems. We explore the coupling topology that arises through the potential drops in a flow channel in a lab-on-chip device that accommodates chemical reactions on electrode arrays. The networks are revealed by analysis of the synchronization patterns with the use of an oscillatory chemical reaction (nickel electrodissolution) and are further confirmed by direct decoding using phase model analysis. In dual electrode configuration, a variety coupling schemes, (uni- or bidirectional positive or negative) were identified depending on the relative placement of the reference and counter electrodes (e.g., placed at the same or the opposite ends of the flow channel). With three electrodes, the network consists of a superposition of a localized (upstream) and global (all-to-all) coupling. With six electrodes, the unique, position dependent coupling topology resulted spatially organized partial synchronization such that there was a synchrony gradient along the quasi-one-dimensional spatial coordinate. The networked, electrode potential (current) spike generating electrochemical reactions hold potential for construction of an in-situ information processing unit to be used in electrochemical devices in sensors and batteries.

  9. Decoding Network Structure in On-Chip Integrated Flow Cells with Synchronization of Electrochemical Oscillators

    Science.gov (United States)

    Jia, Yanxin; Kiss, István Z.

    2017-01-01

    The analysis of network interactions among dynamical units and the impact of the coupling on self-organized structures is a challenging task with implications in many biological and engineered systems. We explore the coupling topology that arises through the potential drops in a flow channel in a lab-on-chip device that accommodates chemical reactions on electrode arrays. The networks are revealed by analysis of the synchronization patterns with the use of an oscillatory chemical reaction (nickel electrodissolution) and are further confirmed by direct decoding using phase model analysis. In dual electrode configuration, a variety coupling schemes, (uni- or bidirectional positive or negative) were identified depending on the relative placement of the reference and counter electrodes (e.g., placed at the same or the opposite ends of the flow channel). With three electrodes, the network consists of a superposition of a localized (upstream) and global (all-to-all) coupling. With six electrodes, the unique, position dependent coupling topology resulted spatially organized partial synchronization such that there was a synchrony gradient along the quasi-one-dimensional spatial coordinate. The networked, electrode potential (current) spike generating electrochemical reactions hold potential for construction of an in-situ information processing unit to be used in electrochemical devices in sensors and batteries. PMID:28387237

  10. Double-layer rotor magnetic shield performance analysis in high temperature superconducting synchronous generators under short circuit fault conditions

    Science.gov (United States)

    Hekmati, Arsalan; Aliahmadi, Mehdi

    2016-12-01

    High temperature superconducting, HTS, synchronous machines benefit from a rotor magnetic shield in order to protect superconducting coils against asynchronous magnetic fields. This magnetic shield, however, suffers from exerted Lorentz forces generated in light of induced eddy currents during transient conditions, e.g. stator windings short-circuit fault. In addition, to the exerted electromagnetic forces, eddy current losses and the associated effects on the cryogenic system are the other consequences of shielding HTS coils. This study aims at investigating the Rotor Magnetic Shield, RMS, performance in HTS synchronous generators under stator winding short-circuit fault conditions. The induced eddy currents in different circumferential positions of the rotor magnetic shield along with associated Joule heating losses would be studied using 2-D time-stepping Finite Element Analysis, FEA. The investigation of Lorentz forces exerted on the magnetic shield during transient conditions has also been performed in this paper. The obtained results show that double line-to-ground fault is of the most importance among different types of short-circuit faults. It was revealed that when it comes to the design of the rotor magnetic shields, in addition to the eddy current distribution and the associated ohmic losses, two phase-to-ground fault should be taken into account since the produced electromagnetic forces in the time of fault conditions are more severe during double line-to-ground fault.

  11. Impact of synchronous metastasis distribution on cancer specific survival in renal cell carcinoma after radical nephrectomy with tumor thrombectomy.

    Science.gov (United States)

    Tilki, Derya; Hu, Brian; Nguyen, Hao G; Dall'Era, Marc A; Bertini, Roberto; Carballido, Joaquín A; Chandrasekar, Thenappan; Chromecki, Thomas; Ciancio, Gaetano; Daneshmand, Siamak; Gontero, Paolo; Gonzalez, Javier; Haferkamp, Axel; Hohenfellner, Markus; Huang, William C; Koppie, Theresa M; Linares, Estefania; Lorentz, C Adam; Mandel, Philipp; Martinez-Salamanca, Juan I; Master, Viraj A; Matloob, Rayan; McKiernan, James M; Mlynarczyk, Carrie M; Montorsi, Francesco; Novara, Giacomo; Pahernik, Sascha; Palou, Juan; Pruthi, Raj S; Ramaswamy, Krishna; Rodriguez Faba, Oscar; Russo, Paul; Shariat, Shahrokh F; Spahn, Martin; Terrone, Carlo; Thieu, William; Vergho, Daniel; Wallen, Eric M; Xylinas, Evanguelos; Zigeuner, Richard; Libertino, John A; Evans, Christopher P

    2015-02-01

    Metastatic renal cell carcinoma can be clinically diverse in terms of the pattern of metastatic disease and response to treatment. We studied the impact of metastasis and location on cancer specific survival. The records of 2,017 patients with renal cell cancer and tumor thrombus who underwent radical nephrectomy and tumor thrombectomy from 1971 to 2012 at 22 centers in the United States and Europe were analyzed. Number and location of synchronous metastases were compared with respect to patient cancer specific survival. Multivariable Cox regression models were used to quantify the impact of covariates. Lymph node metastasis (155) or distant metastasis (725) was present in 880 (44%) patients. Of the patients with distant disease 385 (53%) had an isolated metastasis. The 5-year cancer specific survival was 51.3% (95% CI 48.6-53.9) for the entire group. On univariable analysis patients with isolated lymph node metastasis had a significantly worse cancer specific survival than those with a solitary distant metastasis. The location of distant metastasis did not have any significant effect on cancer specific survival. On multivariable analysis the presence of lymph node metastasis, isolated distant metastasis and multiple distant metastases were independently associated with cancer specific survival. Moreover higher tumor thrombus level, papillary histology and the use of postoperative systemic therapy were independently associated with worse cancer specific survival. In our multi-institutional series of patients with renal cell cancer who underwent radical nephrectomy and tumor thrombectomy, almost half of the patients had synchronous lymph node or distant organ metastasis. Survival was superior in patients with solitary distant metastasis compared to isolated lymph node disease. Copyright © 2015 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  12. The NOvA Data Acquistion System: A highly distributed, synchronized, continuous readout system for a long baseline neutrino experiment

    CERN Document Server

    CERN. Geneva

    2012-01-01

    The NOvA experiment at Fermi National Accelerator Lab, has been designed and optimized to perform a suite of measurements critical to our understanding of the neutrino’s properties, their oscillations and their interactions. NOvA presents a unique set of data acquisition and computing challenges due to the immense size of the detectors, the data volumes that are generated through the continuous digitization of the frontend systems, and the need to buffer the full data stream to allow for highly asynchronous triggering and extraction of physics events. These challenges are compounded by the stringent timing and synchronization requirements that are placed on the acquisition systems by the need to precisely correlate information between the accelerator complex and the remote detector locations. The NOvA Data Acquisition system has been designed and built to meets these challenges. The system utilizes a highly modular, novel acquisition and event building scheme, which has been deployed on a large hierarch...

  13. 120 MB/S and 240 MB/S bit synchronizer-signal conditioners for NASA high data rate applications

    Science.gov (United States)

    Gray, J. S.

    1976-01-01

    Two bit synchronizer-signal conditioners (BSSC) developed for NASA high data rate applications such as earth resources monitoring are described. One BSSC is centered at 120 MB/s and the other at 240 Mb/s. These subsystems are featured out of the total hardware developed because the BSSC is such a key subsystem in determining overall system statistical performance. These units represent an evolution of high data rate BSSC's available at low data rates. Numerous inputs/outputs, control functions, indicators, plus the ability to minimize the effects of various signal perturbations are provided. Examples of allowed perturbations are input level variations, bit rate variance static and dynamic, baseline, transition density, bandlimiting, etc., as well as noise. Emphasis in the past has been primarily concerned only with noise.

  14. Synchronous generators

    CERN Document Server

    Boldea, Ion

    2005-01-01

    This work begins with an introduction to energy resources and the main electric energy conversion solutions, along with efficiency and environmental merits and demerits. The classification and principles of various electric generator topologies are covered alongside their power ratings and main applications including constant-speed synchronous gene

  15. Simple Design Approach for Low Torque Ripple and High Output Torque Synchronous Reluctance Motors

    Directory of Open Access Journals (Sweden)

    Mohamed Nabil Fathy Ibrahim

    2016-11-01

    Full Text Available The rotor design of Synchronous Reluctance Motors (SynRMs has a large effect on their efficiency, torque density and torque ripple. In order to achieve a good compromise between these three goals, an optimized rotor geometry is necessary. A finite element method (FEM is a good tool for the optimization. However, the computation time is an obstacle as there are many geometrical parameters to be optimized. The flux-barrier widths and angles are the two most crucial parameters for the SynRM output torque and torque ripple. This paper proposes an easy-to-use set of parametrized equations to select appropriate values for these two rotor parameters. With these equations, the reader can design a SynRM of distributed windings with a low torque ripple and with a better average torque. The methodology is valid for a wide range of SynRMs. To check the validity of the proposed equations, the sensitivity analysis for the variation of these two parameters on the SynRM torque and torque ripple is carried out. In addition, the analysis in this paper gives insight into the behavior of the machine as a function of these two parameters. Furthermore, the torque and torque ripple of SynRMs having a rotor with three, four and five flux-barriers are compared with three literature approaches. The comparison shows that the proposed equations are effective in choosing the flux-barrier angles and widths for low torque ripple and better average torque. Experimental results have been obtained to confirm the FEM results and to validate the methodology for choosing the rotor parameters.

  16. Recurrent Renal Cell Carcinoma with Synchronous Tumor Growth in Azygoesophageal Recess and Duodenum: A Rare Cause of Anemia and Upper Gastrointestinal Bleeding

    Directory of Open Access Journals (Sweden)

    Vamshidhar R. Vootla

    2015-01-01

    Full Text Available Renal cell carcinoma (RCC has potential to present with distant metastasis several years after complete resection. The common sites of metastases include the lungs, bones, liver, renal fossa, and brain. RCCs metastasize rarely to the duodenum, and duodenal metastasis presenting with acute gastrointestinal bleed is infrequently reported in literature. We present a case of synchronous presentation of duodenal and azygoesophageal metastasis manifesting as acute upper gastrointestinal bleeding, four years after undergoing nephrectomy for RCC. The patient underwent further workup and was treated with radiation. The synchronous presentation is rare and stresses the importance of searching for recurrence of RCC in patients presenting with acute gastrointestinal bleeding.

  17. A model of smooth muscle cell synchronization in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; Aalkjær, Christian; Nilsson, Holger

    2007-01-01

    Vasomotion is a rhythmic variation in microvascular diameter. Although known for more than 150 years, the cellular processes underlying the initiation of vasomotion are not fully understood. In the present study a model of a single cell is extended by coupling a number of cells into a tube...... depolarization, and influx of extracellular calcium. Low [cGMP] is associated only with unsynchronized waves. At intermediate concentrations, cells display either waves or whole cell oscillations, but these remain unsynchronized between cells. Whole cell oscillations are associated with rhythmic variation...

  18. Endothelial adhesion of synchronized gastric tumor cells changes during cell cycle transit and correlates with the expression level of CD44 splice variants

    Institute of Scientific and Technical Information of China (English)

    Anton Oertl; Jens Castein; Tobias Engl; Wolf-Dietrich Beecken; Dietger Jonas; Richard Melamed; Roman A. Blaheta

    2005-01-01

    AIM: To study adhesion capacity and CD44 expression of human gastric adenocarcinoma MKN45 cells at different stages of a first cell cycle.METHODS: MKN45 cells were synchronized by aphidicolin and assayed for adhesion to an endothelial cell (HUVEC)monolayer. Surface expression of CD44 and CD44 splice variants on MKN45 cells was evaluated by flow cytometry.Functional relevance of CD44 adhesion receptors was investigated by blocking studies using anti CD44 monoclonal antibodies or by hyaluronan digestion.RESULTS: Adhesion of MKN45 to HUVEC was increased during G2/M transit, after which adhesion returned to baseline levels with cell cycle completion. In parallel, CD44splice variants CD44v4, CD44v5, and CD44v7 were all upregulated on MKN45 during cell cycle progression with a maximum effect in G2/M. The function of CD44 surface receptors was assessed with specific receptor blocking monodonal antibodies or removal of hyaluronan by digestion with hyaluronidase. Both strategies inhibited tumor cell adhesion to HUVEC by nearly 50%, which indicates that MKN45-HUVEC-interaction is CD44 dependent.CONCLUSION: CD44 expression level is linked to the cell cycle in gastrointestinal tumor cells, which in turn leads to cell cyde dependent alterations of their adhesion behaviour to endothelium.

  19. Comparison of the duration of the cell cycle in successive generation of synchronously dividing antheridial filaments of Chara vulgaris L. as measured with 3H thymidine

    Directory of Open Access Journals (Sweden)

    M. Godlewska

    2015-01-01

    Full Text Available Duration of the cell cycle in synchronously dividing cells of successive generation of antheridial filaments in Chara vulgaris L. was estimated on-the basis of labeling with 3H thymidine. Duration of the cell cycle is proportional to the volume of cells and with their decreasing in the consequence1 of consecutive divisions, the cell cycle becomes shorter. In the 2-, 4-, 8-, and 16-cell generations the length of the S period remains constant, so the duration of the G2 period is gradually reduced.

  20. Power quality improvement of single-phase photovoltaic systems through a robust synchronization method

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Yang, Yongheng;

    2014-01-01

    An increasing amount of single-phase photovoltaic (PV) systems on the distribution network requires more advanced synchronization methods in order to meet the grid codes with respect to power quality and fault ride through capability. The response of the synchronization technique selected...... is crucial for the performance of PV inverters. In this paper, a new synchronization method with good dynamics and accurate response under highly distorted voltage is proposed. This method uses a Multi-Harmonic Decoupling Cell (MHDC), which cancels out the oscillations on the synchronization signals due...

  1. Potassium-chloride cotransporter 3 interacts with Vav2 to synchronize the cell volume decrease response with cell protrusion dynamics.

    Directory of Open Access Journals (Sweden)

    Adèle Salin-Cantegrel

    Full Text Available Loss-of-function of the potassium-chloride cotransporter 3 (KCC3 causes hereditary motor and sensory neuropathy with agenesis of the corpus callosum (HMSN/ACC, a severe neurodegenerative disease associated with defective midline crossing of commissural axons in the brain. Conversely, KCC3 over-expression in breast, ovarian and cervical cancer is associated with enhanced tumor cell malignancy and invasiveness. We identified a highly conserved proline-rich sequence within the C-terminus of the cotransporter which when mutated leads to loss of the KCC3-dependent regulatory volume decrease (RVD response in Xenopus Laevis oocytes. Using SH3 domain arrays, we found that this poly-proline motif is a binding site for SH3-domain containing proteins in vitro. This approach identified the guanine nucleotide exchange factor (GEF Vav2 as a candidate partner for KCC3. KCC3/Vav2 physical interaction was confirmed using GST-pull down assays and immuno-based experiments. In cultured cervical cancer cells, KCC3 co-localized with the active form of Vav2 in swelling-induced actin-rich protruding sites and within lamellipodia of spreading and migrating cells. These data provide evidence of a molecular and functional link between the potassium-chloride co-transporters and the Rho GTPase-dependent actin remodeling machinery in RVD, cell spreading and cell protrusion dynamics, thus providing new insights into KCC3's involvement in cancer cell malignancy and in corpus callosum agenesis in HMSN/ACC.

  2. The Synchronization of Replication and Division Cycles in Individual E. coli Cells.

    Science.gov (United States)

    Wallden, Mats; Fange, David; Lundius, Ebba Gregorsson; Baltekin, Özden; Elf, Johan

    2016-07-28

    Isogenic E. coli cells growing in a constant environment display significant variability in growth rates, division sizes, and generation times. The guiding principle appears to be that each cell, during one generation, adds a size increment that is uncorrelated to its birth size. Here, we investigate the mechanisms underlying this "adder" behavior by mapping the chromosome replication cycle to the division cycle of individual cells using fluorescence microscopy. We have found that initiation of chromosome replication is triggered at a fixed volume per chromosome independent of a cell's birth volume and growth rate. Each initiation event is coupled to a division event after a growth-rate-dependent time. We formalize our findings in a model showing that cell-to-cell variation in division timing and cell size is mainly driven by variations in growth rate. The model also explains why fast-growing cells display adder behavior and correctly predict deviations from the adder behavior at slow growth. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A model of smooth muscle cell synchronization in the arterial wall

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian; Aalkjær, Christian; Nilsson, Holger

    2007-01-01

    Vasomotion is a rhythmic variation in microvascular diameter. Although known for more than 150 years, the cellular processes underlying initiation of vasomotion are not fully understood. In the present study a model of a single cell is extended by coupling a number of cells into a tube. The simul...

  4. A case of treatment in a patient with synchronous bilateral renal cell carcinoma and simultaneous metastatic involvement of both adrenal glands: Clinical observation

    Directory of Open Access Journals (Sweden)

    V. R. Latypov

    2014-01-01

    Full Text Available Synchronous bilateral renal cell carcinoma occurs in 1.4 % of cases. The probability of bilateral adrenal metastases from renal cell carcinoma is less than 0.5 %. The clinical observation presents a case of synchronous bilateral renal cell carcinoma and simultaneous metastatic involvement of both adrenal glands. A 55‑year-old male patient was adm tted with the signs of hematuria and anemia to the Unit of Urology, Clinic of General Surgery, Siberian State Medical University. He was found to have synchronous bilateral renal cell carcinoma and simultaneous bilateral adrenal involvement. Sequential surgical treatment – radical nephrectomy (with adrenal gland removal on the right side and, after 3 months, adrenalectomy and kidney resection on the left side were performed. All the organs removed displayed tumors that proved to be renal cell carcinomas (a clear cell variant. There were lymph node metastases in the right-sided renal portal. Postoperatively, the investigators performed hormone replacement therapy for adrenal insufficiency, an immunotherapy cycle, three cycles of targeted therapy withsorafenib and sunitinib (at an interval of 0.5–2 years, and insulin therapy for new-onset diabetes mellitus. The duration of a follow-up was 6.2 years. When describing the case, the patient was alive and showed a generalized tumorous process with extensive tumor involvement of the solitary kidney. Sunitinib therapy was used.

  5. Synchronization of stochastic Ca²(+) release units creates a rhythmic Ca²(+) clock in cardiac pacemaker cells.

    Science.gov (United States)

    Maltsev, Anna V; Maltsev, Victor A; Mikheev, Maxim; Maltseva, Larissa A; Sirenko, Syevda G; Lakatta, Edward G; Stern, Michael D

    2011-01-19

    In sinoatrial node cells of the heart, beating rate is controlled, in part, by local Ca²(+) releases (LCRs) from the sarcoplasmic reticulum, which couple to the action potential via electrogenic Na(+)/Ca²(+) exchange. We observed persisting, roughly periodic LCRs in depolarized rabbit sinoatrial node cells (SANCs). The features of these LCRs were reproduced by a numerical model consisting of a two-dimensional array of stochastic, diffusively coupled Ca²(+) release units (CRUs) with fixed refractory period. Because previous experimental studies showed that β-adrenergic receptor stimulation increases the rate of Ca²(+) release through each CRU (dubbed I(spark)), we explored the link between LCRs and I(spark) in our model. Increasing the CRU release current I(spark) facilitated Ca²(+)-induced-Ca²(+) release and local recruitment of neighboring CRUs to fire more synchronously. This resulted in a progression in simulated LCR size (from sparks to wavelets to global waves), LCR rhythmicity, and decrease of LCR period that parallels the changes observed experimentally with β-adrenergic receptor stimulation. The transition in LCR characteristics was steeply nonlinear over a narrow range of I(spark), resembling a phase transition. We conclude that the (partial) periodicity and rate regulation of the "Calcium clock" in SANCs are emergent properties of the diffusive coupling of an ensemble of interacting stochastic CRUs. The variation in LCR period and size with I(spark) is sufficient to account for β-adrenergic regulation of SANC beating rate.

  6. Role of synchronous activation of cerebellar purkinje cell ensembles in multi-joint movement control

    NARCIS (Netherlands)

    T.M. Hoogland (Tycho); J.R. de Gruijl (Jornt); L. Witter (Laurens); M.I. Canto (Marcia Irene); C.I. de Zeeuw (Chris)

    2015-01-01

    textabstractIt is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated

  7. Role of Synchronous Activation of Cerebellar Purkinje Cell Ensembles in Multi-joint Movement Control

    NARCIS (Netherlands)

    Hoogland, Tycho M; De Gruijl, Jornt R; Witter, Laurens; Canto, Cathrin B; De Zeeuw, Chris I

    2015-01-01

    It is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated to what

  8. Role of synchronous activation of cerebellar purkinje cell ensembles in multi-joint movement control

    NARCIS (Netherlands)

    T.M. Hoogland (Tycho); J.R. de Gruijl (Jornt); L. Witter (Laurens); M.I. Canto (Marcia Irene); C.I. de Zeeuw (Chris)

    2015-01-01

    textabstractIt is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated

  9. Role of Synchronous Activation of Cerebellar Purkinje Cell Ensembles in Multi-joint Movement Control

    NARCIS (Netherlands)

    Hoogland, Tycho M; De Gruijl, Jornt R; Witter, Laurens; Canto, Cathrin B; De Zeeuw, Chris I

    2015-01-01

    It is a longstanding question in neuroscience how elaborate multi-joint movements are coordinated coherently. Microzones of cerebellar Purkinje cells (PCs) are thought to mediate this coordination by controlling the timing of particular motor domains. However, it remains to be elucidated to what ext

  10. Cell cycle implication on nitrogen acquisition and synchronization in Thalassiosira weissflogii (Bacillariophyceae).

    Science.gov (United States)

    Mocquet, Christophe; Sciandra, Antoine; Talec, Amélie; Bernard, Olivier

    2013-04-01

    The Michaelis-Menten model of nitrogen (N) acquisition, originally used to represent the effect of nutrient concentration on the phytoplankton uptake rate, is inadequate when other factors show temporal variations. Literature generally links diurnal oscillations of N acquisition to a response of the physiological status of microalgae to photon flux density (PFD) and substrate availability. This work describes how the cell cycle also constitutes a significant determinant of N acquisition and, when appropriate, assesses the impact of this property at the macroscopic level. For this purpose, we carried out continuous culture experiments with the diatom Thalassiosira weissflogii (Grunow) G. Fryxell & Hasle exposed to various conditions of light and N supply. The results revealed that a decrease in N acquisition occurred when a significant proportion of the population was in mitosis. This observation suggests that N acquisition is incompatible with mitosis and therefore that its acquisition rate is not constant during the cell cycle. In addition, environmental conditions, such as light and nutrient supply disrupt the cell cycle at the level of the individual cell, which impacts synchrony of the population.

  11. High-accuracy diagnostic tool for electron cloud observation in the LHC based on synchronous phase measurements

    Science.gov (United States)

    Esteban Müller, J. F.; Baudrenghien, P.; Mastoridis, T.; Shaposhnikova, E.; Valuch, D.

    2015-11-01

    Electron cloud effects, which include heat load in the cryogenic system, pressure rise, and beam instabilities, are among the main intensity limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was proposed and developed to monitor the e-cloud activity and it has already been used successfully during the LHC run 1 (2010-2012) and it is being intensively used in operation during the start of the LHC run 2 (2015-2018). It is based on the fact that the power loss of each bunch due to e-cloud can be estimated using bunch-by-bunch measurement of the synchronous phase. The measurements were done using the existing beam phase module of the low-level rf control system. In order to achieve the very high accuracy required, corrections for reflection in the cables and for systematic errors need to be applied followed by a post-processing of the measurements. Results clearly show the e-cloud buildup along the bunch trains and its time evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield. The total beam power loss can be computed as a sum of the contributions from all bunches and compared with the heat load deposited in the cryogenic system.

  12. 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) Digital Coincidence System Based on Synchronous High-Speed Multichannel Data Acquisition

    CERN Document Server

    Chen, Jifeng; Liang, Juncheng; Liu, Jiacheng

    2015-01-01

    A dedicated 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe)digital coincidence system has been developed in this work, which includes five acquisition channels. Three analog-to-digital converter (ADC) acquisition channels with an acquisition resolution of 8 bits and acquisition rate of 1GSPS (sample per second) are utilized to collect the signals from three Photo multiplier tubes (PMTs) which are adopted to detect {\\beta} decay, and two acquisition channels with an acquisition resolution of 16 bits and acquisition rate of 50MSPS are utilized to collect the signals from high-purity germanium (HPGe) which are adopted to detect {\\gamma} decay. In order to increase the accuracy of the coincidence system, all the five acquisition channels are synchronous within 500ps. The data collected by the five acquisition channels will be transmitted to the host PC through PCI bus and saved as a file. Off-line software is applied for the 4{\\pi}{\\beta} (LS)-{\\gamma} (HPGe) coincidence and data analysis as needed in practical application. W...

  13. Fuzzy Adaptive Repetitive Control for Periodic Disturbance with Its Application to High Performance Permanent Magnet Synchronous Motor Speed Servo Systems

    Directory of Open Access Journals (Sweden)

    Junxiao Wang

    2016-09-01

    Full Text Available For reducing the steady state speed ripple, especially in high performance speed servo system applications, the steady state precision is more and more important for real servo systems. This paper investigates the steady state speed ripple periodic disturbance problem for a permanent magnet synchronous motor (PMSM servo system; a fuzzy adaptive repetitive controller is designed in the speed loop based on repetitive control and fuzzy information theory for reducing periodic disturbance. Firstly, the various sources of the PMSM speed ripple problem are described and analyzed. Then, the mathematical model of PMSM is given. Subsequently, a fuzzy adaptive repetitive controller based on repetitive control and fuzzy logic control is designed for the PMSM speed servo system. In addition, the system stability analysis is also deduced. Finally, the simulation and experiment implementation are respectively based on the MATLAB/Simulink and TMS320F2808 of Texas instrument company, DSP (digital signal processor hardware platform. Comparing to the proportional integral (PI controller, simulation and experimental results show that the proposed fuzzy adaptive repetitive controller has better periodic disturbance rejection ability and higher steady state precision.

  14. Analysis of Factors Controlling Cell Cycle that Can Be Synchronized Nondestructively During Root Cap Development

    Energy Technology Data Exchange (ETDEWEB)

    Martha Hawes

    2011-02-04

    Publications and presentations during the final funding period, including progress in defining the substrate specificity, the primary goal of the project, are listed below. Both short-term and long-term responses mediated by PsUGT1 have been characterized in transgenic or mutant pea, alfalfa, and Arabidopsis with altered expression of PsUGT1. Additional progress includes evaluation of the relationship between control of the cell cycle by PsUGT1 and other glycosyltransferase and glycosidase enzymes that are co-regulated in the legume root cap during the onset of mitosis and differentiation. Transcriptional profiling and multidimensional protein identification technology ('MudPIT') have been used to establish the broader molecular context for the mechanism by which PsUGT1 controls cell cycle in response to environmental signals. A collaborative study with the Norwegian Forest Research Institute (who provided $10,000.00 in supplies and travel funds for collaborator Dr. Toril Eldhuset to travel to Arizona and Dr. H. H. Woo to travel to Norway) made it possible to establish that the inducible root cap system for studying carbohydrate synthesis and solubilization is expressed in gymnosperm as well as angiosperm species. This discovery provides an important tool to amplify the potential applications of the research in defining conserved cell cycle machinery across a very broad range of plant species and habitats. The final work, published during 2009, revealed an additional surprising parallel with mammalian immune responses: The cells whose production is controlled by PsUGT1 appear to function in a manner which is analogous to that of white blood cells, by trapping and killing in an extracellular manner. This may explain why mutation within the coding region of PsUGT1 and its homolog in humans (UGT1) is lethal to plants and animals. The work has been the subject of invited reviews. A postdoctoral fellow, eight undergraduate students, four M.S. students and

  15. Aggressive Trimodality Therapy for T1N2M1 Nonsmall Cell Lung Cancer with Synchronous Solitary Brain Metastasis: Case Report and Rationale

    Directory of Open Access Journals (Sweden)

    Timothy N. Showalter

    2009-01-01

    Full Text Available Aggressive treatment, including resection of both metastasis and primary tumor, has been studied for non-small cell lung cancer patients with synchronous solitary brain metastasis. Involvement of mediastinal lymph nodes is considered a poor prognostic factor and a contraindication to surgical resection of the primary lung tumor after treatment for brain metastasis. Here we present the case of a patient who presented with a Stage IV T1N2M1 non-small cell lung cancer with synchronous solitary brain metastasis. He is alive and without evidence of disease two years after aggressive, multimodality treatment that included craniotomy, whole-brain radiation therapy, thoracic surgery, chemotherapy, and mediastinal radiation therapy.

  16. In vitro developmental competence of pig nuclear transferred embryos: effects of GFP transfection, refrigeration, cell cycle synchronization and shapes of donor cells.

    Science.gov (United States)

    Zhang, Yun-Hai; Pan, Deng-Ke; Sun, Xiu-Zhu; Sun, Guo-Jie; Liu, Xiao-Hui; Wang, Xiao-Bo; Tian, Xing-Hua; Li, Yan; Dai, Yun-Ping; Li, Ning

    2006-08-01

    The present study was designed to evaluate the feasibility of producing pig transgenic blastocysts expressing enhanced green fluorescent protein (GFP) and to examine the effects of shape and preparation methods of donor cells on in vitro developmental ability of pig nuclear transferred embryos (NTEs). In experiment 1, the effect of GFP transfection on development of pig NTEs was evaluated. The cleavage and blastocyst rates showed no significant difference between NTEs derived from transfected and non-transfected donors. In experiment 2, the effect of different nuclear donor preparation methods on in vitro development of NTEs was examined. The cleavage rate showed no statistically significant differences among three preparation methods. The blastocyst rates of donor cells treated once at -4 degrees C and those of freshly digested cells were similar to each other (26.3% vs 17.9%). The lowest blastocyst rates (5.88%) were observed when cells cryopreserved at -196 degrees C were used as donors. In experiment 3, the effect of different cell cycle synchronization methods on the in vitro development potential of pig NTEs was evaluated. The cleavage rate of NTEs derived from cycling cells was much better than that of NTEs derived from serum-starved cells (64.4% vs 50.5%, p refrigerated pig GFP-transfected cells could be used as donors in nuclear transfer and these NTEs could be effectively developed to blastocyst stage; (ii) serum starvation of GFP-transfected cells is not required for preimplantation development of pig NTEs; and (iii) a rough surface of GFP-transfected donor cells affects fusion rate negatively but has no influence on the cleavage rate or blastocyst rate of pig NTEs.

  17. Synchronous Multicentric Giant Cell Tumour of Distal Radius and Sacrum with Pulmonary Metastases

    Directory of Open Access Journals (Sweden)

    Varun Sharma Tandra

    2015-01-01

    Full Text Available Giant cell tumour (GCT is an uncommon primary bone tumour, and its multicentric presentation is exceedingly rare. We report a case of a 45-year-old female who presented to us with GCT of left distal radius. On the skeletal survey, osteolytic lesion was noted in her right sacral ala. Biopsy confirmed both lesions as GCT. Pulmonary metastasis was also present. Resection-reconstruction arthroplasty for distal radius and thorough curettage and bone grafting of the sacral lesion were done. Multicentric GCT involving distal radius and sacrum with primary sacral involvement is not reported so far to our knowledge.

  18. Synchronous starphotometry and lidar measurements at Eureka in High Canadian Arctic

    Directory of Open Access Journals (Sweden)

    K. Baibakov

    2015-02-01

    Full Text Available We present recent progress related to the night-time retrievals of aerosol and cloud optical depth using starphotometry over the PEARL (Polar Environmental Atmospheric Research Laboratory station at Eureka (Nunavut, Canada in the High Arctic (80° N, 86° W. In the spring of 2011 and 2012, the SPSTAR starphotometer was employed to acquire aerosol optical depth (AOD measurements while vertical aerosol and cloud backscatter coefficient profiles were acquired using the CANDAC Raman Lidar (CRL. Several events were detected and characterized using starphotometry-lidar synergy: aerosols (short term aerosol events on 9 and 10 March 2011; a potential multi-night aerosol event across three polar nights (13–15 March 2012, a thin cloud event (21 February 2011 and a very low altitude ice crystals (10 March 2011. Using a simple backscatter coefficient threshold criterion we calculated fine and coarse (sub and super-micron mode AODs from the vertically integrated CRL profiles. These were compared with their starphotometry analogues produced from a spectral deconvolution algorithm. The process-level analysis showed, in general, good agreement in terms of the physical coherence between high frequency starphotometry and lidar data. We argue that R2 (coefficient of determination is the most robust means of comparing lidar and starphotometer data since it is sensitive to significant optico-physical variations associated with these two independent data sources while being minimally dependent on retrieval and calibration artifacts. Differences between the fine and course mode components of the starphotometry and lidar data is clearly also useful but is more dependent on such artifacts. Studying climatological seasonal aerosol trends necessitates effective cloud-screening procedures: temporal and spectral cloud screening of starphotometry data was found to agree moderately well with temporal cloud screening results except in the presence of thin homogeneous cloud

  19. [A Case of Synchronous Multiple Esophageal Cancers Composed of Squamous Cell Carcinoma and Barrett's Adenocarcinoma].

    Science.gov (United States)

    Kobayashi, Toshiyuki; Shiozaki, Atsushi; Fujiwara, Hitoshi; Konishi, Hirotaka; Arita, Tomohiro; Kosuga, Toshiyuki; Morimura, Ryo; Murayama, Yasutoshi; Komatsu, Shuhei; Kuriu, Yoshiaki; Ikoma, Hisashi; Nakanishi, Masayoshi; Ichikawa, Daisuke; Okamoto, Kazuma; Otsuji, Eigo

    2015-11-01

    A 67-year-old man was admitted to our hospital for treatment for multiple superficial esophageal cancers. Screening upper gastrointestinal endoscopy examination revealed a superficial squamous cell carcinoma (SCC) at the middle thoracic esophagus and Barrett's epithelium and a superficial adenocarcinoma at the abdominal esophagus. We performed a subtotal esophagectomy with gastric tube reconstruction via the retrosternal route. Pathological examination revealed a Barrett's adenocarcinoma at the abdominal esophagus. Esophageal cancer is thought to be a multicentric disease, and we sometimes find multiple esophageal cancers. In Japan, most cases of multiple esophageal cancers are composed of SCCs, and the occurrence of multiple esophageal cancers composed of SCC and Barrett's adenocarcinoma is rare. In contrast, the number of the patients with Barrett's esophagus is increasing, and the number of the patients with Barrett's adenocarcinoma also seems to be on the rise. Therefore, it is important be aware of the possibility of multiple esophageal cancers composed of SCC and Barrett's adenocarcinoma while making diagnoses.

  20. Sporadic bilateral synchronous multicentric papillary renal cell carcinoma masquerading as bilateral multifocal pyelonephritis.

    Science.gov (United States)

    Karthikeyan, V S; Dorairajan, L N; Kumar, S; Vijayakumar, A R; Ramesh, A; Ganesh Rajesh, N; Halanaik, D; Gupta, S

    2014-07-01

    Pyelonephritis is defined as an inflammation of the kidney and renal pelvis. The diagnosis is usually clinical. Acute multifocal bacterial nephritis is a rare form of pyelonephritis that is more severe and sepsis is more common. We report a patient who presented with fever and right-sided abdominal pain associated with right flank tenderness, suggesting right acute pyelonephritis. Bilateral multifocal pyelonephritis was diagnosed on ultrasonography, radionuclide renal scintigraphy and computed tomography. However, owing to non-resolution of symptoms, a biopsy was performed, which showed bilateral papillary renal cell carcinoma (PRCC). PRCC is known to exhibit multicentricity. To our knowledge, a case of bilateral multicentric PRCC masquerading as bilateral multifocal pyelonephritis has not been reported in the English literature. This case highlights the need to be vigilant while treating patients with focal lesions of the kidney as an inflammatory condition lest a malignancy should be missed.

  1. Electrical synchronization of spin-torque oscillators driven by self-emitted high frequency current (Conference Presentation)

    Science.gov (United States)

    Tsunegi, Sumito; Lebrun, Romain; Grimaldi, Eva; Jenkins, Alex S.; Kubota, Hitoshi; Yakushiji, Kay; Bortolotti, Paolo; Grollier, Julie; Fukushima, Akio; Yuasa, Shinji; Cros, Vincent

    2016-10-01

    The rich physics of spin transfer nano-oscillators (STNO) has provoked a huge interest to create a new generation of multi-functional microwave spintronic devices [1]. It has been often emphasized that their nonlinear behavior gives a unique opportunity to tune their radiofrequency (rf) properties but at the cost of large phase noise, not compatible with practical applications. To tackle this issue as well as to open the opportunities to new developments for non-boolean computations [1], one strategy is to use electrical synchronization of STOs through the rf current. Thereby, it is crucial to understand how the synchronization forces transmitted through the electric current. In this talk, we will first present the results of an experimental study showing the self-synchronization of STNO by re-injecting its rf current after a certain delay time [2]. In the second part, we demonstrate that the synchronization of two vortex-STNOs connected in parallel can be tuned either by an artificial delay or by the spin transfer torques [3]. The synchronization of spin-torque oscillators, combined with the drastic improvement of the rf-features (linewidth decreases by a factor of 2 and power increases by a factor of 4) in the synchronized state, marks an important milestone towards a new generation of rf-devices based on STNO. The authors acknowledge the financial support from ANR agency (SPINNOVA: ANR-11-NANO-0016) and EU grant (MOSAIC: ICT-FP7-317950). [1] N. Locatelli, V. Cros, and J. Grollier, Nat Mater 13, 11 (2014). [2] S. Tsunegi et al., arXiv:1509.05583 (2015) [3] R. Lebrun et al., arXiv:1601.01247 (2016)

  2. Multivariate statistical process control (MSPC) using Raman spectroscopy for in-line culture cell monitoring considering time-varying batches synchronized with correlation optimized warping (COW).

    Science.gov (United States)

    Liu, Ya-Juan; André, Silvère; Saint Cristau, Lydia; Lagresle, Sylvain; Hannas, Zahia; Calvosa, Éric; Devos, Olivier; Duponchel, Ludovic

    2017-02-01

    Multivariate statistical process control (MSPC) is increasingly popular as the challenge provided by large multivariate datasets from analytical instruments such as Raman spectroscopy for the monitoring of complex cell cultures in the biopharmaceutical industry. However, Raman spectroscopy for in-line monitoring often produces unsynchronized data sets, resulting in time-varying batches. Moreover, unsynchronized data sets are common for cell culture monitoring because spectroscopic measurements are generally recorded in an alternate way, with more than one optical probe parallelly connecting to the same spectrometer. Synchronized batches are prerequisite for the application of multivariate analysis such as multi-way principal component analysis (MPCA) for the MSPC monitoring. Correlation optimized warping (COW) is a popular method for data alignment with satisfactory performance; however, it has never been applied to synchronize acquisition time of spectroscopic datasets in MSPC application before. In this paper we propose, for the first time, to use the method of COW to synchronize batches with varying durations analyzed with Raman spectroscopy. In a second step, we developed MPCA models at different time intervals based on the normal operation condition (NOC) batches synchronized by COW. New batches are finally projected considering the corresponding MPCA model. We monitored the evolution of the batches using two multivariate control charts based on Hotelling's T(2) and Q. As illustrated with results, the MSPC model was able to identify abnormal operation condition including contaminated batches which is of prime importance in cell culture monitoring We proved that Raman-based MSPC monitoring can be used to diagnose batches deviating from the normal condition, with higher efficacy than traditional diagnosis, which would save time and money in the biopharmaceutical industry. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Cytoskeletal actin networks in motile cells are critically self-organized systems synchronized by mechanical interactions.

    Science.gov (United States)

    Cardamone, Luca; Laio, Alessandro; Torre, Vincent; Shahapure, Rajesh; DeSimone, Antonio

    2011-08-23

    Growing networks of actin fibers are able to organize into compact, stiff two-dimensional structures inside lamellipodia of crawling cells. We put forward the hypothesis that the growing actin network is a critically self-organized system, in which long-range mechanical stresses arising from the interaction with the plasma membrane provide the selective pressure leading to organization. We show that a simple model based only on this principle reproduces the stochastic nature of lamellipodia protrusion (growth periods alternating with fast retractions) and several of the features observed in experiments: a growth velocity initially insensitive to the external force; the capability of the network to organize its orientation; a load-history-dependent growth velocity. Our model predicts that the spectrum of the time series of the height of a growing lamellipodium decays with the inverse of the frequency. This behavior is a well-known signature of self-organized criticality and is confirmed by unique optical tweezer measurements performed in vivo on neuronal growth cones.

  4. Nutritional recommendations for synchronized swimming.

    Science.gov (United States)

    Robertson, Sherry; Benardot, Dan; Mountjoy, Margo

    2014-08-01

    The sport of synchronized swimming is unique, because it combines speed, power, and endurance with precise synchronized movements and high-risk acrobatic maneuvers. Athletes must train and compete while spending a great amount of time underwater, upside down, and without the luxury of easily available oxygen. This review assesses the scientific evidence with respect to the physiological demands, energy expenditure, and body composition in these athletes. The role of appropriate energy requirements and guidelines for carbohydrate, protein, fat, and micronutrients for elite synchronized swimmers are reviewed. Because of the aesthetic nature of the sport, which prioritizes leanness, the risks of energy and macronutrient deficiencies are of significant concern. Relative Energy Deficiency in Sport and disordered eating/eating disorders are also of concern for these female athletes. An approach to the healthy management of body composition in synchronized swimming is outlined. Synchronized swimmers should be encouraged to consume a well-balanced diet with sufficient energy to meet demands and to time the intake of carbohydrate, protein, and fat to optimize performance and body composition. Micronutrients of concern for this female athlete population include iron, calcium, and vitamin D. This article reviews the physiological demands of synchronized swimming and makes nutritional recommendations for recovery, training, and competition to help optimize athletic performance and to reduce risks for weight-related medical issues that are of particular concern for elite synchronized swimmers.

  5. One-Stage and Two-Stage Schemes of High Performance Synchronous PWM with Smooth Pulses-Ratio Changing

    DEFF Research Database (Denmark)

    Oleschuk, V.; Blaabjerg, Frede

    2002-01-01

    modulation with synchronization of the voltage waveform of the inverter and with smooth pulse-ratio changing. Voltage spectra do not contain even harmonic and sub-harmonics (combined harmonics) during the whole control range including the zone of overmodulation. Examples of determination of the basic control...

  6. Self-organized synchronous oscillations in a network of excitable cells coupled by gap junctions.

    Science.gov (United States)

    Lewis, T J; Rinzel, J

    2000-11-01

    Recent evidence suggests that electrical coupling plays a role in generating oscillatory behaviour in networks of neurons; however, the underlying mechanisms have not been identified. Using a cellular automata model proposed by Traub et al (Traub R D, Schmitz D, Jefferys J G and Draguhn A 1999 High-frequency population oscillations are predicted to occur in hippocampal pyramidal neural networks interconnected by axo-axonal gap junctions Neuroscience 92 407-26), we describe a novel mechanism for self-organized oscillations in networks that have strong, sparse random electrical coupling via gap junctions. The network activity is generated by random spontaneous activity that is moulded into regular population oscillations by the propagation of activity through the network. We explain how this activity gives rise to particular dependences of mean oscillation frequency on network connectivity parameters and on the rate of spontaneous activity, and we derive analytical expressions to approximate the mean frequency and variance of the oscillations. In doing so, we provide insight into possible mechanisms for frequency control and modulation in networks of neurons.

  7. A Synchronization Method for Single-Phase Grid-Tied Inverters

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Yang, Yongheng;

    2016-01-01

    The controllers of single-phase grid-tied inverters require improvements to enable distribution generation systems to meet the grid codes/standards with respect to power quality and the fault ride through capability. In that case, the response of the selected synchronization technique is crucial...... for the performance of the entire grid-tied inverter. In this paper, a new synchronization method with good dynamics and high accuracy under a highly distorted voltage is proposed. This method uses a Multi-Harmonic Decoupling Cell (MHDC), which thus can cancel out the oscillations on the synchronization signals due...

  8. Design and performance characteristics of an electromagnetic interference shielded enclosure for high voltage Pockels cell switching system

    Indian Academy of Sciences (India)

    A K Sharma; K K Mishra; M Raghuramaiah; P A Naik; P D Gupta

    2007-06-01

    An electro-magnetic interference noise shielding enclosure for Pockels cells for high speed synchronized switching has been set-up and tested. The shielding effectiveness of the aluminum enclosures housing the Pockels cells and the electronic circuitry has been measured using a high impedance probe and is found to be $\\sim 50 dB$. This ensures a noise-free and synchronized electro-optic switching in an Nd:glass re-generative amplifier of chirped pulse amplification based table top terawatt laser system.

  9. How to suppress undesired synchronization

    CERN Document Server

    Louzada, V H P; Andrade, J S; Herrmann, H J

    2012-01-01

    It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected ele...

  10. Synchronous Upgrading Iron and Phosphorus Removal from High Phosphorus Oolitic Hematite Ore by High Temperature Flash Reduction

    Directory of Open Access Journals (Sweden)

    Deqing Zhu

    2016-05-01

    Full Text Available In this paper, an effective method was developed to remove phosphorus and upgrade iron from high phosphorus oolitic hematite ore by high temperature flash reduction—a wet magnetic separation process. A thermodynamic analysis of iron and phosphorus mineral reactions and experiments with Fe-P separation process were performed, and the mechanism of phosphorus removal and beneficiation of iron is discussed as well. The results show that under the proper conditions, a final metallic iron powder assaying over 91% Fe and 0.25% P was obtained with iron recovery of 90% and phosphorus removal rate of 91.79% using the new process, indicating that the high temperature flash reduction process is a feasible and efficient way to process this kind of complex and refractory iron ore. Moreover, sodium sulfate is found to be capable of improving the removal of phosphorus and the upgrading of iron, as well as enhancing the growth of metallic iron grains significantly for higher recovery of iron.

  11. Metastases of Renal Cell Carcinoma to the Thyroid Gland with Synchronous Benign and Malignant Follicular Cell-Derived Neoplasms

    Directory of Open Access Journals (Sweden)

    Carlos Zamarrón

    2013-01-01

    Full Text Available Clear cell renal cell carcinoma (CCRCC is the most common origin for metastasis in the thyroid. A 51-year-old woman was referred to our hospital for a subcarinal lesion. Ten years before, the patient had undergone a nephrectomy for CCRCC. Whole-body fluorodeoxyglucose positron emission tomography revealed elevated values in the thyroid gland, while the mediastinum was normal. An endoscopic ultrasonography-guided fine-needle aspiration biopsy of the mediastinal mass was consistent with CCRCC, and this was confirmed after resection. The thyroidectomy specimen also revealed lymphocytic thyroiditis, nodular hyperplasia, one follicular adenoma, two papillary microcarcinomas, and six foci of metastatic CCRCC involving both thyroid lobes. Curiously two of the six metastatic foci were located inside two adenomatoid nodules (tumor-in-tumor. The metastatic cells were positive for cytokeratins, CD10, epidermal growth factor receptor, and vascular endothelial growth factor receptor 2. No BRAF gene mutations were found in any of the primary and metastatic lesions. The patient was treated with sunitinib and finally died due to CCRCC distant metastases 6 years after the thyroidectomy. In CCRCC patients, a particularly prolonged survival rate may be achieved with the appropriate therapy, in contrast to the ominous prognosis typically found in patients with thyroid metastases from other origins.

  12. Dynamical system synchronization

    CERN Document Server

    Luo, Albert C J

    2013-01-01

    Dynamical System Synchronization (DSS) meticulously presents for the first time the theory of dynamical systems synchronization based on the local singularity theory of discontinuous dynamical systems. The book details the sufficient and necessary conditions for dynamical systems synchronizations, through extensive mathematical expression. Techniques for engineering implementation of DSS are clearly presented compared with the existing techniques.  This book also:  Presents novel concepts and methods for dynamical system synchronization Extends beyond the Lyapunov theory for dynamical system synchronization Introduces companion and synchronization of discrete dynamical systems Includes local singularity theory for discontinuous dynamical systems Covers the invariant domains of synchronization Features more than 75 illustrations Dynamical System Synchronization is an ideal book for those interested in better understanding new concepts and methodology for dynamical system synchronization, local singularity...

  13. Variety of synchronous regimes in neuronal ensembles

    Science.gov (United States)

    Komarov, M. A.; Osipov, G. V.; Suykens, J. A. K.

    2008-09-01

    We consider a Hodgkin-Huxley-type model of oscillatory activity in neurons of the snail Helix pomatia. This model has a distinctive feature: It demonstrates multistability in oscillatory and silent modes that is typical for the thalamocortical neurons. A single neuron cell can demonstrate a variety of oscillatory activity: Regular and chaotic spiking and bursting behavior. We study collective phenomena in small and large arrays of nonidentical cells coupled by models of electrical and chemical synapses. Two single elements coupled by electrical coupling show different types of synchronous behavior, in particular in-phase and antiphase synchronous regimes. In an ensemble of three inhibitory synaptically coupled elements, the phenomenon of sequential synchronous dynamics is observed. We study the synchronization phenomena in the chain of nonidentical neurons at different oscillatory behavior coupled with electrical and chemical synapses. Various regimes of phase synchronization are observed: (i) Synchronous regular and chaotic spiking; (ii) synchronous regular and chaotic bursting; and (iii) synchronous regular and chaotic bursting with different numbers of spikes inside the bursts. We detect and study the effect of collective synchronous burst generation due to the cluster formation and the oscillatory death.

  14. High Performance Perovskite Solar Cells.

    Science.gov (United States)

    Tong, Xin; Lin, Feng; Wu, Jiang; Wang, Zhiming M

    2016-05-01

    Perovskite solar cells fabricated from organometal halide light harvesters have captured significant attention due to their tremendously low device costs as well as unprecedented rapid progress on power conversion efficiency (PCE). A certified PCE of 20.1% was achieved in late 2014 following the first study of long-term stable all-solid-state perovskite solar cell with a PCE of 9.7% in 2012, showing their promising potential towards future cost-effective and high performance solar cells. Here, notable achievements of primary device configuration involving perovskite layer, hole-transporting materials (HTMs) and electron-transporting materials (ETMs) are reviewed. Numerous strategies for enhancing photovoltaic parameters of perovskite solar cells, including morphology and crystallization control of perovskite layer, HTMs design and ETMs modifications are discussed in detail. In addition, perovskite solar cells outside of HTMs and ETMs are mentioned as well, providing guidelines for further simplification of device processing and hence cost reduction.

  15. HNPCC-associated synchronous early-stage signet-ring cell carcinomas of colonic origin. A comparative morphological and immunohistochemical study of an intramucosal and a submucosal example

    DEFF Research Database (Denmark)

    Klarskov, Louise; Bernstein, Inge; Holck, Susanne

    2008-01-01

    Signet-ring cell carcinoma (SRCC) developing in the colorectum (CR) is infrequently identified at an early stage (no deeper than submucosa). Most such examples involve the submucosa. Merely 13 cases of intramucosal CR SRCC are at hand. We recently had the opportunity to study a specimen with two...... synchronous early-stage SRCC, developed in a 65-year-old hereditary nonpolyposis colorectal cancer male patient with a known disease-causing mutation in MLH1. A right hemicolectomy specimen comprised a 15-mm intramucosal cecal lesion, featuring zones of conventional tubular adenoma and intraepithelial SRCC...

  16. An optical tweezers, epi-fluorescence/spinning disk confocal- and microfluidic-setup for synchronization studies of glycolytic oscillations in living yeast cells

    Science.gov (United States)

    Mojica-Benavides, Martin; Adiels, Caroline B.; Goksör, Mattias

    2016-09-01

    Due to the significant importance of glycolytic oscillations studies and the recent breakthroughs on single cell analysis, a further interest arrives with intracellular and intercellular responses. Understanding cell-cell communication can give insight to oscillatory behaviors in biological systems, such as insulin secretion from pancreatic β-cells. The aim of this work consists on the manipulation of living yeast cells to study propagation and synchronization of induced glycolytic oscillations. A setup, consisting of an optical tweezers system and microfluidic devices coupled with fluorescence imaging was designed to perform a time dependent observation during artificially induced glycolytic oscillations. Multi-channel flow devices and diffusion chambers were fabricated using soft lithography. Automatized pumps controlled specific flow rates of infused glucose and cyanide solutions, used to induce the oscillations. Flow and diffusion in the microfluidic devices were simulated to assure experimentally the desired coverage of the solutions across the yeast cells, a requirement for time dependent measurements. Using near infrared optical tweezers, yeast cells were trapped and positioned in array configurations, ranging from a single cell to clusters of various symmetries, in order to obtain information about cell-cell communications during the metabolic cycles. Confocal illumination of an entire focal plane using a spinning disk, will allow acquirement of NADH periodic fluorescence signals during glycolytic oscillations. This method permits an improvement of the 2D projection images obtained with wide field microscopy to a tomographic description of the subcellular propagation of the oscillations.

  17. S-phase cells are more sensitive to high-linear energy transfer radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Naidu, M.; Liu, S.; Zhang, P.; Zhang, S.; Wang, H.; Wang, Y.

    2009-07-15

    S-phase cells are more resistant to low-linear energy transfer (LET) ionizing radiation (IR) than nonsynchronized and G{sub 1}-phase cells, because both nonhomologous end-joining (NHEJ) and homologous recombination repair can repair DNA double-strand breaks (DSBs) in the S phase. Although it was reported 3 decades ago that S-phase cells did not show more resistance to high-LET IR than cells in other phases, the mechanism remains unclear. We therefore attempted to study the phenotypes and elucidate the mechanism involved. Wild-type and NHEJ-deficient cell lines were synchronized using the double-thymidine approach. A clonogenic assay was used to detect the sensitivity of nonsynchronized, synchronized S-phase, and G{sub 2}-phase cells to high- and low-LET IR. The amounts of Ku bound to DSBs in the high- and low-LET-irradiated cells were also examined. S-phase wild-type cells (but not NHEJ-deficient cells) were more sensitive to high-LET IR than nonsynchronized and G{sub 2}-phase cells. In addition, S-phase wild-type cells showed less efficient Ku protein binding to DSBs than nonsynchronized and G{sub 2}-phase cells in response to high-LET IR, although all cells at all phases showed similarly efficient levels of Ku protein binding to DSBs in response to low-LET IR. S-phase cells are more sensitive to high-LET IR than nonsynchronized and G{sub 2}-phase cells, because of the following mechanism: it is more difficult for Ku protein to bind to high-LET IR-induced DNA DSBs in S-phase cells than in cells at other phases, which results in less efficient NHEJ.

  18. A separately excited synchronous motor as high efficient drive in electric vehicles; Die stromerregte Synchronmaschine als hocheffizienter Traktionsmotor in Elektrofahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Illiano, Enzo [ETH Zuerich, Zurich (Switzerland). Inst. fuer Werkzeugmaschinen und Fertigung; Brusa Elektronik AG, Sennfeld (Switzerland)

    2013-08-15

    The separately excited synchronous motor has several advantages which make this topology a very promising traction drive for electric vehicles. The comparison of the separately excited motor with other common topologies also shows the proper regulation of the current in the rotor will rise the complexity of the entire system. In addition the presence of a rotor current has a negative effect on the continuous power of the motor, as the investigations of ETH Zuerich and Brusa show. An optimised motor regulation and an accurate rotor shape design are indispensible to reduce the power deficit. (orig.)

  19. Neural synchronization via potassium signaling

    DEFF Research Database (Denmark)

    Postnov, Dmitry E; Ryazanova, Ludmila S; Mosekilde, Erik

    2006-01-01

    Using a relatively simple model we examine how variations of the extracellular potassium concentration can give rise to synchronization of two nearby pacemaker cells. With the volume of the extracellular space and the rate of potassium diffusion as control parameters, the dual nature of this reso...

  20. Regulation and controlled synchronization

    NARCIS (Netherlands)

    Huijberts, H.J.C.; Huijberts, H.J.C.; Nijmeijer, Henk; Willems, R.M.A.

    1998-01-01

    We investigate the problem of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous transmitter dynamics and controlled receiver dynamics. The question is to find a (output) feedback controller that achieves matching between transmitter and

  1. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...

  2. Control of synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Synchronous motors are indubitably the most effective device to drive industrial production systems and robots with precision and rapidity. Their control law is thus critical for combining at the same time high productivity to reduced energy consummation. As far as possible, the control algorithms must exploit the properties of these actuators. Therefore, this work draws on well adapted models resulting from the Park's transformation, for both the most traditional machines with sinusoidal field distribution and for machines with non-sinusoidal field distribution which are more and more used in

  3. Multicentric synchronous recurrent aggressive fibromatosis

    Directory of Open Access Journals (Sweden)

    Kavita Kohli

    2012-01-01

    Full Text Available Extra-abdominal desmoid tumors are known as aggressive fibromatosis (AFM. Synchronous and metachronous multicentric aggressive fibromatosis are rare lesions and pose dilemma in diagnosis and management. A rare and interesting case of recurrent multicentric, synchronous AFM is presented which to the best of our knowledge has not been reported earlier. A young male presented with well defined, hard, fixed swelling on the thigh. Resected tumor mass on histopathology was diagnosed as an extra abdominal fibromatosis. He presented again after two months with swelling at the same site; and two more swellings on the foot. Fine needle aspiration cytology (FNAC from all three sites was performed; and was suggestive of benign spindle cell lesion of fibrogenic origin with the possibility of multicentric synchronous recurrent aggressive fibromatosis.

  4. Inverse anticipating chaos synchronization.

    Science.gov (United States)

    Shahverdiev, E M; Sivaprakasam, S; Shore, K A

    2002-07-01

    We derive conditions for achieving inverse anticipating synchronization where a driven time-delay chaotic system synchronizes to the inverse future state of the driver. The significance of inverse anticipating chaos in delineating synchronization regimes in time-delay systems is elucidated. The concept is extended to cascaded time-delay systems.

  5. Cluster Synchronization Algorithms

    NARCIS (Netherlands)

    Xia, Weiguo; Cao, Ming

    2010-01-01

    This paper presents two approaches to achieving cluster synchronization in dynamical multi-agent systems. In contrast to the widely studied synchronization behavior, where all the coupled agents converge to the same value asymptotically, in the cluster synchronization problem studied in this paper,

  6. Sincronización de Células de Tabaco (Nicotiana tabacum NT-1 Synchronization of tobacco cells (Nicotiana tabacum NT-1

    Directory of Open Access Journals (Sweden)

    León F Ruiz

    2010-01-01

    Full Text Available Se ha evaluado la capacidad sincronizante de afidicolina e hidroxiurea en cultivos de células de tabaco (Nicotiana tabacum NT-1. Los cultivos sincronizados son poderosas herramientas en estudios moleculares y bioquímicos relacionados al ciclo celular y comúnmente se utilizan químicos para bloquear el ciclo celular. La línea celular de tabaco (Nicotiana tabacum NT-1 proviene de la línea celular TBY-2, caracterizándose NT-1 por su menor velocidad de crecimiento y tamaño celular heterogéneo. Los resultados mostraron una sincronía del 30 % de NT-1 con afidicolina 5 mg/ml, similar a la obtenida con TBY-2. Se probaron diferentes concentraciones de hidroxiurea, obteniéndose niveles óptimos de sincronización de hasta 31 % con 0.75 mM. Se muestra también que es posible sincronizar cultivos NT-1 en porcentajes similares a cultivos TBY-2 con afidicolina e hidroxiurea. Para este propósito, se recomienda la hidroxiurea por ser químicamente más estable y económica.The synchronizing capacity of aphidicolin and hydroxyurea on NT-1 cultures of tobacco cells (Nicotiana tabacum NT-1. Synchronized cell cultures are a powerful tool in biochemistry and molecular studies related to cell cycle and commonly chemicals are used to block the biochemical cycle. The tobacco cell line NT-1 comes from cell line TBY-2, the former being characterized with a slower growth rate and heterogeneous cell size. Results show 30 % synchrony with 5 mg/ml aphidicolin, similar to that obtained with TBY-2. Different concentrations of hydroxyurea were tested, obtaining an optimal synchrony of 31 % at 0.75 mM of concentration. It is also shown that it is possible to synchronize NT-1 cultures in similar percentages to those obtained with TBY-2, with either aphidicolin or hydroxyurea. For this purpose, hydroxyurea is recommended because of its lower cost and chemical stability.

  7. Phase synchronization of two anharmonic nanomechanical oscillators.

    Science.gov (United States)

    Matheny, Matthew H; Grau, Matt; Villanueva, Luis G; Karabalin, Rassul B; Cross, M C; Roukes, Michael L

    2014-01-10

    We investigate the synchronization of oscillators based on anharmonic nanoelectromechanical resonators. Our experimental implementation allows unprecedented observation and control of parameters governing the dynamics of synchronization. We find close quantitative agreement between experimental data and theory describing reactively coupled Duffing resonators with fully saturated feedback gain. In the synchronized state we demonstrate a significant reduction in the phase noise of the oscillators, which is key for sensor and clock applications. Our work establishes that oscillator networks constructed from nanomechanical resonators form an ideal laboratory to study synchronization--given their high-quality factors, small footprint, and ease of cointegration with modern electronic signal processing technologies.

  8. Diagnostic sensitivity of ¹⁸fluorodeoxyglucose positron emission tomography for detecting synchronous multiple primary cancers in head and neck cancer patients.

    Science.gov (United States)

    Kondo, Norio; Tsukuda, Mamoru; Nishimura, Goshi

    2012-05-01

    We assessed the sensitivity of positron emission tomography (PET) for detecting synchronous multiple primary cancers, particularly synchronous esophageal cancers in head and neck cancer patients. We retrospectively reviewed 230 head and neck cancer patients. All the patients routinely underwent the following examinations: urinalysis, occult blood, tumor marker detection [squamous cell carcinoma (SCC), cytokeratin fragment (CYFRA), and carcinoembryonic antigen (CEA)], esophagogastroduodenoscopy, colonoscopy (when CEA was high or occult blood was positive), abdominal ultrasonography, plain chest computed tomography (CT), and PET. Bronchoscopy was performed when CT revealed lung shadow of central region. Synchronous multiple primary cancers were detected in 42 (18.2%) patients. The diagnostic sensitivity of PET for synchronous primary cancers was as follows: esophagus, 7.6% (1/13); stomach, 25.0% (2/8); lung, 66.7% (4/6); head and neck, 75.0% (3/4); colon, 0% (0/1); kidney, 0% (0/1); and subcutaneous, 100% (1/1). The sensitivity of PET for detecting synchronous esophageal cancers is low because these are early-stage cancers (almost stage 0-I). Therefore, it is necessary to perform esophagogastroduodenoscopy for detecting synchronous esophageal cancers. PET is an important additional tool for detecting synchronous multiple primary cancers because the diagnostic sensitivity of PET in synchronous head and neck cancer and lung cancer is high. But PET has the limitation of sensitivity for synchronous multiple primary cancers because the diagnostic sensitivity of PET in synchronous esophageal cancer is very low.

  9. A 3-D Novel Highly Chaotic System with Four Quadratic Nonlinearities, its Adaptive Control and Anti-Synchronization with Unknown Parameters

    Directory of Open Access Journals (Sweden)

    S. Vaidyanathan

    2014-11-01

    Full Text Available This research work proposes a seven-term 3-D novel dissipative chaotic system with four quadratic nonlinearities. The Lyapunov exponents of the 3-D novel chaotic system are obtained as L1 = 11.36204, L2 = 0 and L3 = –47.80208. Since the sum of the Lyapunov exponents is negative, the 3-D novel chaotic system is dissipative. Also, the Kaplan-Yorke dimension of the 3-D novel chaotic system is obtained as DKY = 2.23769. The maximal Lyapunov exponent (MLE of the novel chaotic system is L1 = 11.36204, which is a large value for a polynomial chaotic system. Thus, the proposed 3-D novel chaotic system is highly chaotic. The phase portraits of the novel chaotic system simulated using MATLAB depict the highly chaotic attractor of the novel system. This research work also discusses other qualitative properties of the system. Next, an adaptive controller is designed to stabilize the 3-D novel chaotic system with unknown parameters. Also, an adaptive synchronizer is designed to achieve anti-synchronization of the identical 3-D novel chaotic systems with unknown parameters. The adaptive results derived in this work are established using Lyapunov stability theory. MATLAB simulations have been shown to illustrate and validate all the main results derived in this work.

  10. Development and testing of a 2.5 kW synchronous generator with a high temperature superconducting stator and permanent magnet rotor

    Science.gov (United States)

    Qu, Timing; Song, Peng; Yu, Xiaoyu; Gu, Chen; Li, Longnian; Li, Xiaohang; Wang, Dewen; Hu, Boping; Chen, Duxing; Zeng, Pan; Han, Zhenghe

    2014-04-01

    High temperature superconducting (HTS) armature windings have the potential for increasing the electric loading of a synchronous generator due to their high current transport capacity, which could increase the power density of an HTS rotating machine. In this work, a novel synchronous generator prototype with an HTS stator and permanent magnet rotor has been developed. It has a basic structure of four poles and six slots. The armature winding was constructed from six double-pancake race-track coils with 44 turns each. It was designed to deliver 2.5 kW at 300 rpm. A concentrated winding configuration was proposed, to prevent interference at the ends of adjacent HTS coils. The HTS stator was pressure mounted into a hollow Dewar cooled with liquid nitrogen. The whole stator could be cooled down to around 82 K by conduction cooling. In the preliminary testing, the machine worked properly and could deliver 1.8 kW power when the armature current was 14.4 A. Ic for the HTS coils was found to be suppressed due to the influence of the temperature and the leakage field.

  11. A single-sided linear synchronous motor with a high temperature superconducting coil as the excitation system

    Energy Technology Data Exchange (ETDEWEB)

    Yen, F; Li, J; Zheng, S J; Liu, L; Ma, G T; Wang, J S; Wang, S Y; Liu Wei, E-mail: fei.h.yen@gmail.co [Applied Superconductivity Laboratory, Southwest Jiaotong University, Chengdu, Sichuan 610031 (China)

    2010-10-15

    Thrust measurements were performed on a coil made of a YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} coated conductor acting as the excitation system of a single-sided linear synchronous motor. The superconducting coil was a single pancake in the shape of a racetrack with 100 turns, the width and effective lengths were 42 mm and 84 mm, respectively. The stator was made of conventional copper wire. At 77 K and a gap of 10 mm, with an operating direct current of I{sub DC} = 30 A for the superconducting coil and alternating current of I{sub AC} = 9 A for the stator coils, a thrust of 24 N was achieved. With addition of an iron core, thrust was increased by 49%. With addition of an iron back-plate, thrust was increased by 70%.

  12. Macronuclear Cytology of Synchronized Tetrahymena pyriformis

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, I. L.; Padilla, G. M.; Miller, Jr., O. L.

    1966-05-01

    Elliott, Kennedy and Bak ('62) and Elliott ('63) followed fine structural changes in macronuclei of Tetrahymena pyriformis which were synchronized by the heat shock method of Scherbaum and Zeuthen ('54). Using Elliott's morphological descriptions as a basis, we designed our investigations with two main objectives: First, to again study the. morphological changes which occur in the macronucleus of Tetrahymena synchronized by the heat shock method. The second objective was to compare these observations with Tetrahymena synchronized by an alternate method recently reported by Padilla and Cameron ('64). Therefore, we were able to compare the results from two different synchronization methods and to contrast these findings with the macronuclear cytology of Tetrahymena taken from a logarithmically growing culture. Comparison of cells treated in these three different ways enables us to evaluate the two different synchronization methods and to gain more information on the structural changes taking place in the macronucleus of Tetrahymena as a function of the cell cycle. Our observations were confined primarily to nucleolar morphology. The results indicate that cells synchronized by the Padilla and Cameron method more closely resemble logarithmically growing Tetrahymena in the macronuclear structure than do cells obtained by the Scherbaum and·Zeuthen synchronization method. .

  13. Synchronization of chaotic systems.

    Science.gov (United States)

    Pecora, Louis M; Carroll, Thomas L

    2015-09-01

    We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.

  14. Synchronization of chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Pecora, Louis M.; Carroll, Thomas L. [U.S. Naval Research Laboratory, Washington, District of Columbia 20375 (United States)

    2015-09-15

    We review some of the history and early work in the area of synchronization in chaotic systems. We start with our own discovery of the phenomenon, but go on to establish the historical timeline of this topic back to the earliest known paper. The topic of synchronization of chaotic systems has always been intriguing, since chaotic systems are known to resist synchronization because of their positive Lyapunov exponents. The convergence of the two systems to identical trajectories is a surprise. We show how people originally thought about this process and how the concept of synchronization changed over the years to a more geometric view using synchronization manifolds. We also show that building synchronizing systems leads naturally to engineering more complex systems whose constituents are chaotic, but which can be tuned to output various chaotic signals. We finally end up at a topic that is still in very active exploration today and that is synchronization of dynamical systems in networks of oscillators.

  15. A New Design of Clock Synchronization Algorithm

    Directory of Open Access Journals (Sweden)

    Jingmeng Liu

    2014-05-01

    Full Text Available The introduction of Ethernet makes the distributed network system more flexible and efficient, but it also makes nodes which are far apart from each other unable to work in the same time basis due to the long distance. This is not allowed for the high performance requirements of the system synchronization, such as high-precision multiaxis machining system. This paper presents a high-precision network clock synchronization algorithm, namely, optimal PI clock servo, which imposes a PI controller in order to compensate for the clock drift of each network node. Then a simulation platform established by the toolbox TrueTime is used to verify the stability of the algorithm and compare it with the clock synchronization algorithm of EtherCAT. The results show that the new synchronization algorithm has higher synchronization precision and faster convergence rate.

  16. Chaotic Synchronization with Filter Based on Wavelet Transformation

    Institute of Scientific and Technical Information of China (English)

    XiaoanZHOU; JunfengLAN; 等

    1999-01-01

    A kind of chaotic synchronization method is presented in the paper,In the transmitter,part signals are transformed by wavelet and the detail information is removed.In the receiver.the component with low frequency is reconstructed and discrete feedback is used,we show that synchronization of two identical structure chaotic systems is attained.The effect of feedback on chaotic synchronization is discussed.Using the synchronous method,the transmitting signal is transported in compressible way system resource is saved,the component with high frequency is filtered and the effect of disturbance on synchronization is reduced.The synchronization method is illustrated by numerical simulation experiment.

  17. How to suppress undesired synchronization.

    Science.gov (United States)

    Louzada, V H P; Araújo, N A M; Andrade, J S; Herrmann, H J

    2012-01-01

    Examples of synchronization can be found in a wide range of phenomena such as neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement is observed when contrarians sit at the highly connected elements. The same qualitative results are obtained for artificially generated networks and two real ones, namely, the Routers of the Internet and a neuronal network.

  18. Study of High-Voltage Inverter Synchronous Switching Function%高压变频器同步投切功能的研究

    Institute of Scientific and Technical Information of China (English)

    徐卫青; 杨志勇; 冯骥

    2014-01-01

    Introduction was made to the basic principle and realizing method of main circuit of high-voltage inverter synchronous switching system. This paper gave the synchronous switching flow chart and its protective logic. On switching, by using software phase-locked loop technique, inverter output voltage was adjusted, as well as the grid voltage phase, amplitude, frequency in unifor-mity, then the switching between inverter and power was accomplished by the PLC and automatic switch. The test has verified the feasibility of the method, with higher site application value.%介绍了高压变频同步投切系统主回路的基本原理及实现方法,给出了同步切换流程及其保护逻辑,切换时利用软件锁相环技术调整变频器输出电压与电网电压的相位、幅值、频率一致,然后通过可编程控制器及自动开关完成变频与工频间的切换,试验验证了该方法的可行性,具有较高的现场应用价值。

  19. KPU-300, a Novel Benzophenone-Diketopiperazine-Type Anti-Microtubule Agent with a 2-Pyridyl Structure, Is a Potent Radiosensitizer That Synchronizes the Cell Cycle in Early M Phase.

    Directory of Open Access Journals (Sweden)

    Kohei Okuyama

    Full Text Available KPU-300 is a novel colchicine-type anti-microtubule agent derived from plinabulin (NPI-2358. We characterized the effects of KPU-300 on cell cycle kinetics and radiosensitization using HeLa cells expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci. Cells treated with 30 nM KPU-300 for 24 h were efficiently synchronized in M phase and contained clearly detectable abnormal Fucci fluorescence. Two-dimensional flow-cytometric analysis revealed a fraction of cells distinct from the normal Fucci fluorescence pattern. Most of these cells were positive for an M phase marker, the phosphorylated form of histone H3. Cells growing in spheroids responded similarly to the drug, and the inner quiescent fraction also responded after recruitment to the growth fraction. When such drug-treated cells were irradiated in monolayer, a remarkable radiosensitization was observed. To determine whether this radiosensitization was truly due to the synchronization in M phase, we compared the radiosensitivity of cells synchronized by KPU-300 treatment and cells in early M phase isolated by a combined method that took advantage of shake-off and the properties of the Fucci system. Following normalization against the surviving fraction of cells treated with KPU-300 alone, the surviving fractions of cells irradiated in early M phase coincided. Taken together with potential vascular disrupting function in vivo, we propose a novel radiosensitizing strategy using KPU-300.

  20. KPU-300, a Novel Benzophenone–Diketopiperazine–Type Anti-Microtubule Agent with a 2-Pyridyl Structure, Is a Potent Radiosensitizer That Synchronizes the Cell Cycle in Early M Phase

    Science.gov (United States)

    Okuyama, Kohei; Kaida, Atsushi; Hayashi, Yoshiki; Hayashi, Yoshio; Harada, Kiyoshi; Miura, Masahiko

    2015-01-01

    KPU-300 is a novel colchicine-type anti-microtubule agent derived from plinabulin (NPI-2358). We characterized the effects of KPU-300 on cell cycle kinetics and radiosensitization using HeLa cells expressing the fluorescent ubiquitination-based cell cycle indicator (Fucci). Cells treated with 30 nM KPU-300 for 24 h were efficiently synchronized in M phase and contained clearly detectable abnormal Fucci fluorescence. Two-dimensional flow-cytometric analysis revealed a fraction of cells distinct from the normal Fucci fluorescence pattern. Most of these cells were positive for an M phase marker, the phosphorylated form of histone H3. Cells growing in spheroids responded similarly to the drug, and the inner quiescent fraction also responded after recruitment to the growth fraction. When such drug-treated cells were irradiated in monolayer, a remarkable radiosensitization was observed. To determine whether this radiosensitization was truly due to the synchronization in M phase, we compared the radiosensitivity of cells synchronized by KPU-300 treatment and cells in early M phase isolated by a combined method that took advantage of shake-off and the properties of the Fucci system. Following normalization against the surviving fraction of cells treated with KPU-300 alone, the surviving fractions of cells irradiated in early M phase coincided. Taken together with potential vascular disrupting function in vivo, we propose a novel radiosensitizing strategy using KPU-300. PMID:26716455

  1. HIGH TEMPERATURE POLYMER FUEL CELLS

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Qingfeng, Li; He, Ronghuan

    2003-01-01

    This paper will report recent results from our group on polymer fuel cells (PEMFC) based on the temperature resistant polymer polybenzimidazole (PBI), which allow working temperatures up to 200°C. The membrane has a water drag number near zero and need no water management at all. The high working...... temperature allows for utilization of the excess heat for fuel processing. Moreover, it provides an excellent CO tolerance of several percent, and the system needs no purification of hydrogen from a reformer. Continuous service for over 6 months at 150°C has been demonstrated....

  2. High-accuracy diagnostic tool for electron cloud observation in the LHC based on synchronous phase measurements

    CERN Document Server

    Esteban Müller, J F; Shaposhnikova, E; Valuch, D; Mastoridis, T

    2014-01-01

    Electron cloud effects such as heat load in the cryogenic system, pressure rise and beam instabilities are among the main limitations for the LHC operation with 25 ns spaced bunches. A new observation tool was developed to monitor the e-cloud activity and has been successfully used in the LHC during Run 1 (2010-2012). The power loss of each bunch due to the e-cloud can be estimated using very precise bunch-by-bunch measurement of the synchronous phase shift. In order to achieve the required accuracy, corrections for reflection in the cables and some systematic errors need to be applied followed by a post-processing of the measurements. Results clearly show the e-cloud build-up along the bunch trains and its evolution during each LHC fill as well as from fill to fill. Measurements during the 2012 LHC scrubbing run reveal a progressive reduction in the e-cloud activity and therefore a decrease in the secondary electron yield (SEY). The total beam power loss can be computed as a sum of the contributions from all...

  3. Three-Dimensional Human Cardiac Tissue Engineered by Centrifugation of Stacked Cell Sheets and Cross-Sectional Observation of Its Synchronous Beatings by Optical Coherence Tomography.

    Science.gov (United States)

    Haraguchi, Yuji; Hasegawa, Akiyuki; Matsuura, Katsuhisa; Kobayashi, Mari; Iwana, Shin-Ichi; Kabetani, Yasuhiro; Shimizu, Tatsuya

    2017-01-01

    Three-dimensional (3D) tissues are engineered by stacking cell sheets, and these tissues have been applied in clinical regenerative therapies. The optimal fabrication technique of 3D human tissues and the real-time observation system for these tissues are important in tissue engineering, regenerative medicine, cardiac physiology, and the safety testing of candidate chemicals. In this study, for aiming the clinical application, 3D human cardiac tissues were rapidly fabricated by human induced pluripotent stem (iPS) cell-derived cardiac cell sheets with centrifugation, and the structures and beatings in the cardiac tissues were observed cross-sectionally and noninvasively by two optical coherence tomography (OCT) systems. The fabrication time was reduced to approximately one-quarter by centrifugation. The cross-sectional observation showed that multilayered cardiac cell sheets adhered tightly just after centrifugation. Additionally, the cross-sectional transmissions of beatings within multilayered human cardiac tissues were clearly detected by OCT. The observation showed the synchronous beatings of the thicker 3D human cardiac tissues, which were fabricated rapidly by cell sheet technology and centrifugation. The rapid tissue-fabrication technique and OCT technology will show a powerful potential in cardiac tissue engineering, regenerative medicine, and drug discovery research.

  4. Cell cycle inhibitory effects of leaf extract from Curcuma vamana M. Sabu & Mangaly on mitotically synchronous cultures of Physarum polycephalum Schw.

    Science.gov (United States)

    Rajan, I; Remitha, R; Jayasree, P R; Kumar, P R Manish

    2013-01-01

    Leaf extracts of C. vamana, endemic to Kerala state in India, were found to inhibit cell cycle progression in synchronous cultures of P. polycephalum in a concentration and phase-specific manner. Crude alkaloid extract (CAE) elicited maximum cell cycle delays in comparison to soxhletted chloroform, acetone and aqueous extracts. Total alkaloid content of CAE was found to be 64.9 mg/g. CAE showed lowest DPPH radical scavenging activity. Other extracts with higher free radical scavenging activity exhibited lesser cell cycle inhibiting potential. Upto 21% decrease in nuclear DNA was observed in CAE treated samples. However, genotoxicity as evidenced by comet assay was not observed. The extracts were also found to be non-toxic to human RBCs at the highest concentration tested (750 microg/mL). CAE treatment completely suppressed a 63 kDa polypeptide with a concomitant, but weak induction of a 60 kDa polypeptide suggesting that these may be cell cycle related. CAE was found to possess potent antiproliferative activity against PBLs. The study clearly demonstrates the cell cycle inhibitory activity of C. vamana leaf extracts, with CAE being the most potent of them.

  5. Synchronization of MIMO OFDM systems by perfect complete generalized complementary orthogonal loosely synchronous code groups

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; YANG Xun; LI Dao-ben

    2009-01-01

    This article proposes a time/frequency synchronization algorithm in the multiple input multiple output (MIMO) systems, in which the perfect complete generalized complementary orthogonal loosely synchronous code groups are used as the synchronization sequence. The synchronization algorithm is divided into four stages: 1) synchronization in time domain by signal autocorrelation; 2) synchronization in frequency domain by fast Fourier transform (FFT); 3) multipath dissociation using coherent detection and fine time synchronization; 4) fine frequency offset estimation by phase rotation. As per the perfect complete generalized complementary orthogonal loosely synchronous code groups, the cross-correlation and out-of-phase auto-correlation for any relative shift between any two codes is always zero. This ideal property makes the time/frequency synchronization algorithm simple and efficient. The simulation results show that even in the multipath fast fading channel with low signal noise ratio (SNR), the MIMO system can get synchronized both in the time domain and frequency domain with high stability and reliability.

  6. Transition to complete synchronization and global intermittent synchronization in an array of time-delay systems

    Science.gov (United States)

    Suresh, R.; Senthilkumar, D. V.; Lakshmanan, M.; Kurths, J.

    2012-07-01

    We report the nature of transitions from the nonsynchronous to a complete synchronization (CS) state in arrays of time-delay systems, where the systems are coupled with instantaneous diffusive coupling. We demonstrate that the transition to CS occurs distinctly for different coupling configurations. In particular, for unidirectional coupling, locally (microscopically) synchronization transition occurs in a very narrow range of coupling strength but for a global one (macroscopically) it occurs sequentially in a broad range of coupling strength preceded by an intermittent synchronization. On the other hand, in the case of mutual coupling, a very large value of coupling strength is required for local synchronization and, consequently, all the local subsystems synchronize immediately for the same value of the coupling strength and, hence, globally, synchronization also occurs in a narrow range of the coupling strength. In the transition regime, we observe a type of synchronization transition where long intervals of high-quality synchronization which are interrupted at irregular times by intermittent chaotic bursts simultaneously in all the systems and which we designate as global intermittent synchronization. We also relate our synchronization transition results to the above specific types using unstable periodic orbit theory. The above studies are carried out in a well-known piecewise linear time-delay system.

  7. Synchronous Control Method and Realization of Automated Pharmacy Elevator

    Science.gov (United States)

    Liu, Xiang-Quan

    Firstly, the control method of elevator's synchronous motion is provided, the synchronous control structure of double servo motor based on PMAC is accomplished. Secondly, synchronous control program of elevator is implemented by using PMAC linear interpolation motion model and position error compensation method. Finally, the PID parameters of servo motor were adjusted. The experiment proves the control method has high stability and reliability.

  8. Preliminary OFDM based acoustic communication for underwater sensor networks synchronization

    OpenAIRE

    Pallarés Valls, Oriol; Sarriá Gandul, David; Viñolo Monzoncillo, Carlos; Río Fernandez, Joaquín del; Manuel Lázaro, Antonio

    2013-01-01

    This work presents a first approach to wireless underwater sensor networks UWSN time synchronization, using OFDM (Orthogonal Frequency Division Multiplexing) acoustic communication and time reference served by a synchronization protocol. This synchronization and type of modulation allows getting a low drift clock on each sensor, on a high efficiency underwater communication network. Peer Reviewed

  9. Current Analysis and Modification Measures of High Voltage Synchronous Motor Shaft%高压同步电机轴电流分析及改装措施

    Institute of Scientific and Technical Information of China (English)

    侯江继

    2014-01-01

    通过现场高压同步电机与焦炉气压缩机轴瓦烧损的故障处理,分析了轴电流产生的原因及电机和焦炉气压缩机滑动轴瓦的危害,并提出防止电机产生轴电流电腐蚀的有效措施。%Through the fault processing of the burned field high voltage synchronous motor and coke oven gas compressor, this paper analyzes the cause of the shaft current and its hazard on motor and coke oven gas compressor sliding bearing, and puts forward some effective measures to prevent the motor shaft current electric corrosion.

  10. Materials for high-temperature fuel cells

    CERN Document Server

    Jiang, San Ping; Lu, Max

    2013-01-01

    There are a large number of books available on fuel cells; however, the majority are on specific types of fuel cells such as solid oxide fuel cells, proton exchange membrane fuel cells, or on specific technical aspects of fuel cells, e.g., the system or stack engineering. Thus, there is a need for a book focused on materials requirements in fuel cells. Key Materials in High-Temperature Fuel Cells is a concise source of the most important and key materials and catalysts in high-temperature fuel cells with emphasis on the most important solid oxide fuel cells. A related book will cover key mater

  11. 基于锁相环的水听器阵列多传感器高精度同步技术%High-precision synchronization acquisition for multiple sensors of hydrophone array based on phase locked loop

    Institute of Scientific and Technical Information of China (English)

    常宗杰; 段发阶; 蒋佳佳; 陈劲; 华香凝; 李彦超

    2013-01-01

    This paper proposed a high-precision synchronous method, which was suitable for the structural characteristics of the hydrophone array and used to handle the acquisition synchronization problems among multiple sensors in the hydrophone array. The method used two-stage synchronization techniques. First, in order to achieve synchronous acquisition among multiple sensors within the same node, it used the phase-locked loop technology. Then, it adopted a transmission delay compensation method which could compensate the synchronous error to attain high-precision synchronous acquisition between the different nodes. It set up an experimental system which consists of one master node and two slave nodes. The test results show that the synchronous acquisition error within the same node is no more than 5 ns and the synchronous acquisition error between the different nodes is no more than 10 ns. Then, the prototype system is further test, and the test results are consistent with the test results from the experimental system. Therefore, the proposed method can achieve high-precision synchronous acquisition among multiple sensors in hydrophone array.%针对水听器阵列中多个传感器采集信号的同步问题,提出了一种适合于水听器阵列结构特点的高精度同步方法.该方法采用两级同步的方式:首先运用锁相环技术,保证同一个节点内多个传感器之间的同步采集;然后采用传输延时补偿的方法来补偿不同节点间的传输延时所引起的同步误差,实现节点之间的高精度同步采集.建立了一个实验系统:它由一个主节点和两个从节点组成.测试结果表明,同一节点内的同步采集误差不大于5 ns,不同节点间的同步采集误差不大于10 ns.对样机系统进行了进一步测试,测试结果与实验系统的测试结果一致.测试结果表明,该方法能实现水听器阵列多传感器间的高精度同步采集.

  12. Synchronous high-grade squamous intraepithelial lesion and adenocarcinoma in situ of cervix in a young woman presenting with hyperchromatic crowded groups in the cervical cytology specimen: report of a case.

    Science.gov (United States)

    Zafar, Nadeem; Balazs, Louisa; Benstein, Barbara D

    2008-11-01

    We report a 29-year-old woman who underwent routine gynecologic evaluation at a community clinic and had a cervical sample drawn for liquid-based cytologic evaluation. At cytology, many hyperchromatic crowded groups (HCG) were present, but a consensus could not be established whether the abnormal cells were primarily glandular or squamous with secondary endocervical glandular involvement. An interpretation of atypical endocervical cells, favor neoplastic, was rendered and biopsy advised if clinically appropriate. At biopsy, the cervix contained synchronous squamous cell carcinoma in situ, secondarily involving endocervical glands, and neighboring adenocarcinoma in situ. Immunohistochemistry for Ki-67 and p16(INK4A) crisply and precisely stained both the lesions, clearly separating them from the adjacent uninvolved mucosa. This case re-emphasizes the challenge associated with accurate evaluation of HCG at cytology, the significance of ancillary testing for surrogate markers of high-risk HPV (HR-HPV) infection, the need for adjunct testing for HPV-DNA in the setting of HCG at cervical cytology, and a recommendation to set up studies to evaluate the role of surrogate markers of HR-HPV infection in cytologic samples with HCG.

  13. Cell cycle synchronization and BrdU incorporation as a tool to study the possible selective elimination of ErbB1 gene in the micronuclei in A549 cells

    Energy Technology Data Exchange (ETDEWEB)

    Lauand, C.; Niero, E.L.; Dias, V.M.; Machado-Santelli, G.M. [Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil)

    2015-03-06

    Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene that encodes epidermal growth factor receptor (EGFR). ErbB1 amplification and mutation are associated with tumor aggressiveness and low response to therapy. The aim of the present study was to design a schedule to synchronize the cell cycle of A549 cell line (a non-small cell lung cancer) and to analyze the possible association between the micronuclei (MNs) and the extrusion of ErbB1 gene extra-copies. After double blocking, by the process of fetal bovine serum deprivation and vincristine treatment, MNs formation was monitored with 5-bromo-2-deoxyuridine (BrdU) incorporation, which is an S-phase marker. Statistical analyses allowed us to infer that MNs may arise both in mitosis as well as in interphase. The MNs were able to replicate their DNA and this process seemed to be non-synchronous with the main cell nuclei. The presence of ErbB1 gene in the MNs was evaluated by fluorescent in situ hybridization (FISH). ErbB1 sequences were detected in the MNs, but a relation between the MNs formation and extrusion of amplified ErbB1could not be established. The present study sought to elucidate the meaning of MNs formation and its association with the elimination of oncogenes or other amplified sequences from the tumor cells.

  14. Cell cycle synchronization and BrdU incorporation as a tool to study the possible selective elimination of ErbB1 gene in the micronuclei in A549 cells

    Directory of Open Access Journals (Sweden)

    C. Lauand

    2015-05-01

    Full Text Available Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene that encodes epidermal growth factor receptor (EGFR. ErbB1 amplification and mutation are associated with tumor aggressiveness and low response to therapy. The aim of the present study was to design a schedule to synchronize the cell cycle of A549 cell line (a non-small cell lung cancer and to analyze the possible association between the micronuclei (MNs and the extrusion of ErbB1 gene extra-copies. After double blocking, by the process of fetal bovine serum deprivation and vincristine treatment, MNs formation was monitored with 5-bromo-2-deoxyuridine (BrdU incorporation, which is an S-phase marker. Statistical analyses allowed us to infer that MNs may arise both in mitosis as well as in interphase. The MNs were able to replicate their DNA and this process seemed to be non-synchronous with the main cell nuclei. The presence of ErbB1 gene in the MNs was evaluated by fluorescent in situ hybridization (FISH. ErbB1 sequences were detected in the MNs, but a relation between the MNs formation and extrusion of amplified ErbB1could not be established. The present study sought to elucidate the meaning of MNs formation and its association with the elimination of oncogenes or other amplified sequences from the tumor cells.

  15. Self-Stabilizing Pulse Synchronization Inspired by Biological Pacemaker Networks

    CERN Document Server

    Daliot, Ariel; Parnas, Hanna

    2008-01-01

    We define the ``Pulse Synchronization'' problem that requires nodes to achieve tight synchronization of regular pulse events, in the settings of distributed computing systems. Pulse-coupled synchronization is a phenomenon displayed by a large variety of biological systems, typically overcoming a high level of noise. Inspired by such biological models, a robust and self-stabilizing Byzantine pulse synchronization algorithm for distributed computer systems is presented. The algorithm attains near optimal synchronization tightness while tolerating up to a third of the nodes exhibiting Byzantine behavior concurrently. Pulse synchronization has been previously shown to be a powerful building block for designing algorithms in this severe fault model. We have previously shown how to stabilize general Byzantine algorithms, using pulse synchronization. To the best of our knowledge there is no other scheme to do this without the use of synchronized pulses.

  16. Is whole-culture synchronization biology's 'perpetual-motion machine'?

    Science.gov (United States)

    Cooper, Stephen

    2004-06-01

    Whole-culture or batch synchronization cannot, in theory, produce a synchronized culture because it violates a fundamental law that proposes that no batch treatment can alter the cell-age order of a culture. In analogy with the history of perpetual-motion machines, it is suggested that the study of these whole-culture 'synchronization' methods might lead to an understanding of general biological principles even though these methods cannot be used to study the normal cell cycle.

  17. Synchronization of networks

    Indian Academy of Sciences (India)

    R E Amritkar

    2008-08-01

    We study the synchronization of coupled dynamical systems on networks. The dynamics is governed by a local nonlinear oscillator for each node of the network and interactions connecting different nodes via the links of the network. We consider existence and stability conditions for both single- and multi-cluster synchronization. For networks with time-varying topology we compare the synchronization properties of these networks with the corresponding time-average network. We find that if the different coupling matrices corresponding to the time-varying networks commute with each other then the stability of the synchronized state for both the time-varying and the time-average topologies are approximately the same. On the other hand, for non-commuting coupling matrices the stability of the synchronized state for the time-varying topology is in general better than the time-average topology.

  18. Elastic interactions synchronize beating in cardiomyocytes.

    Science.gov (United States)

    Cohen, Ohad; Safran, Samuel A

    2016-07-13

    Motivated by recent experimental results, we study theoretically the synchronization of the beating phase and frequency of two nearby cardiomyocyte cells. Each cell is represented as an oscillating force dipole in an infinite, viscoelastic medium and the propagation of the elastic signal within the medium is predicted. We examine the steady-state beating of two nearby cells, and show that elastic interactions result in forces that synchronize the phase and frequency of beating in a manner that depends on their mutual orientation. The theory predicts both in-phase and anti-phase steady-state beating depending on the relative cell orientations, as well as how synchronized beating varies with substrate elasticity and the inter-cell distance. These results suggest how mechanics plays a role in cardiac efficiency, and may be relevant for the design of cardiomyocyte based micro devices and other biomedical applications.

  19. TiC/NiO Core/Shell Nanoarchitecture with Battery-Capacitive Synchronous Lithium Storage for High-Performance Lithium-Ion Battery.

    Science.gov (United States)

    Huang, Hui; Feng, Tong; Gan, Yongping; Fang, Mingyu; Xia, Yang; Liang, Chu; Tao, Xinyong; Zhang, Wenkui

    2015-06-10

    The further development of electrode materials with high capacity and excellent rate capability presents a great challenge for advanced lithium-ion batteries. Herein, we demonstrate a battery-capacitive synchronous lithium storage mechanism based on a scrupulous design of TiC/NiO core/shell nanoarchitecture, in which the TiC nanowire core exhibits a typical double-layer capacitive behavior, and the NiO nanosheet shell acts as active materials for Li(+) storage. The as-constructed TiC/NiO (32 wt % NiO) core/shell nanoarchitecture offers high overall capacity and excellent cycling ability, retaining above 507.5 mAh g(-1) throughout 60 cycles at a current density of 200 mA g(-1) (much higher than theoretical value of the TiC/NiO composite). Most importantly, the high rate capability is far superior to that of NiO or other metal oxide electrode materials, owing to its double-layer capacitive characteristics of TiC nanowire and intrinsic high electrical conductivity for facile electron transport during Li(+) storage process. Our work offers a promising approach via a rational hybridization of two electrochemical energy storage materials for harvesting high capacity and good rate performance.

  20. Transient expression of RAD51 in the late G2-phase is required for cell cycle progression in synchronous Physarum cells.

    Science.gov (United States)

    Le Cigne, Anthony; Menil-Philippot, Vanessa; Fleury, Fabrice; Takahashi, Masayuki; Thiriet, Christophe

    2014-10-01

    The homologous recombination factor RAD51 is highly conserved. This criterion enabled us to identify a RAD51 ortholog in Physarum polycephalum. We found that the Physarum protein presents a high homology to the human protein and cross-reacted with antibodies directed against the human RAD51. Taking advantage of the natural synchrony of millions of nuclei within a single cell of Physarum, we investigated the fluctuation of the amount of the PpRAD51 throughout the cell cycle. Our results showed that in the late G2-phase, RAD51 was transiently expressed in a large quantity. Furthermore, knocking-down RAD51 in the G2-phase abolished this transient expression before mitosis and affected cell cycle progression. These results support the idea that RAD51 plays a role in the progression of the cell cycle in the late G2-phase. © 2014 The Authors Genes to Cells © 2014 by the Molecular Biology Society of Japan and Wiley Publishing Asia Pty Ltd.

  1. Synchronization of Sub-Picosecond Electron and Laser Pulses

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, J.B.; Le Sage G.P.

    2000-08-15

    Sub-picosecond laser-electron synchronization is required to take full advantage of the experimental possibilities arising from the marriage of modern high intensity lasers and high brightness electron beams in the same laboratory. Two particular scenarios stand out in this regard, injection of ultra-short electron pulses in short wavelength laser-driven plasma accelerators, and Compton scattering of laser photons from short electron pulses. Both of these applications demand synchronization, which is subpicosecond, with tens of femtosecond synchronization implied for next-generation experiments. Typically, an RF electron accelerator is synchronized to a short pulse laser system by detecting the repetition signal of a laser oscillator, adjusted to an exact subharmonic of the linac RF frequency, and multiplying or phase locking this signal to produce the master RF clock. Pulse-to-pulse jitter characteristic of self-mode-locked laser oscillators represents a direct contribution to the ultimate timing jitter between a high intensity laser focus and electron beam at the interaction point, or a photocathode drive laser in an RF photoinjector. This timing jitter problem has been addressed most seriously in the context of the RF photoinjector, where the electron beam properties are sensitive functions of relative timing jitter. The timing jitter achieved in synchronized photocathode drive laser systems is near, or slightly below one picosecond. The ultimate time of arrival jitter of the beam at the photoinjector exit is typically a bit smaller than the photocathode drive-laser jitter due to velocity compression effects in the first RF cell of the gun. This tendency of the timing of the electron beam arrival at a given spatial point to lock to the RF lock is strongly reinforced by use of magnetic compression.

  2. Investigating the overload capacity of a direct-driven synchronous permanent magnet wind turbine generator designed using high-voltage cable technology

    Energy Technology Data Exchange (ETDEWEB)

    Solum, A.; Leijon, M. [The Angstrom Laboratory, Uppsala (Sweden). Div. of Electricity and Lightning Research

    2007-09-15

    Utilization of wind energy to maximum permissible limits for generating electrical power has become necessary to meet the global energy demands. Under such circumstances the present day conventional wind turbine generators pose a limitation regarding the overload capability, specifically significant when they need to operate in high-energy wind conditions. It is proposed that by employing a completely different generator winding concept, based on high-voltage cable technology, to a specific generator, it is possible to increase the generator overload capabilities and thereby making it operationally efficient in high wind speed situations. Therefore, the possibility of extracting more energy is predicted to increase. Simulations, based on finite-element methods combined with external circuit models for the generator, have been performed. The results demonstrate that under given thermal and electrical restrictions, a direct-driven permanent magnet synchronous wind turbine generator, based on high-voltage cable windings, is capable of being overloaded more than twice the rated power, thus making it very suitable for strong wind situations. (author)

  3. Analysis of Synchronization for Coupled Hybrid Systems

    DEFF Research Database (Denmark)

    Li, Zheng; Wisniewski, Rafal

    2006-01-01

    In the control systems with coupled multi-subsystem, the subsystems might be synchronized (i.e. all the subsystems have the same operation states), which results in negative influence to the whole system. For example, in the supermarket refrigeration systems, the synchronized switch of each...... subsystem will cause low efficiency, inferior control performance and a high wear on the compressor. This paper takes the supermarket refrigeration systems as an example to analyze the synchronization and its coupling strengths of coupled hybrid systems, which may provide a base for further research...

  4. Experimental Synchronization by Means of Observers

    Directory of Open Access Journals (Sweden)

    R. Martínez-Guerra

    2014-02-01

    Full Text Available In this paper we deal with the experimental synchronization of the Colpitts oscillator in a real-time implementation. Our approach is based on observer design theory in a master-slave configuration thus, a chaos synchronization problem can be posed as an observer design procedure, where the coupling signal is viewed as a measurable output and a slave system is regarded as an observer. A polynomial observer is used for synchronizing the Colpitts oscillator employing linear matrix inequalities. Finally, a comparison with a reduced order observer and a high gain observer is given to assess the performance of the proposed observer.

  5. High-Cycle-Life Lithium Cell

    Science.gov (United States)

    Yen, S. P. S.; Carter, B.; Shen, D.; Somoano, R.

    1985-01-01

    Lithium-anode electrochemical cell offers increased number of charge/ discharge cycles. Cell uses components selected for compatibility with electrolyte solvent: These materials are wettable and chemically stable. Low vapor pressure and high electrochemical stability of solvent improve cell packaging, handling, and safety. Cell operates at modest temperatures - less than 100 degrees C - and is well suited to automotive, communications, and other applications.

  6. Asynchronized synchronous machines

    CERN Document Server

    Botvinnik, M M

    1964-01-01

    Asynchronized Synchronous Machines focuses on the theoretical research on asynchronized synchronous (AS) machines, which are "hybrids” of synchronous and induction machines that can operate with slip. Topics covered in this book include the initial equations; vector diagram of an AS machine; regulation in cases of deviation from the law of full compensation; parameters of the excitation system; and schematic diagram of an excitation regulator. The possible applications of AS machines and its calculations in certain cases are also discussed. This publication is beneficial for students and indiv

  7. Synchronous high-resolution phenotyping of leaf and root growth in Nicotiana tabacum over 24-h periods with GROWMAP-plant

    Directory of Open Access Journals (Sweden)

    Ruts Tom

    2013-01-01

    Full Text Available Abstract Background Root growth is highly responsive to temporal changes in the environment. On the contrary, diel (24 h leaf expansion in dicot plants is governed by endogenous control and therefore its temporal pattern does not strictly follow diel changes in the environment. Nevertheless, root and shoot are connected with each other through resource partitioning and changing environments for one organ could affect growth of the other organ, and hence overall plant growth. Results We developed a new technique, GROWMAP-plant, to monitor growth processes synchronously in leaf and root of the same plant with a high resolution over the diel period. This allowed us to quantify treatment effects on the growth rates of the treated and non-treated organ and the possible interaction between them. We subjected the root system of Nicotiana tabacum seedlings to three different conditions: constant darkness at 22°C (control, constant darkness at 10°C (root cooling, and 12 h/12 h light–dark cycles at 22°C (root illumination. In all treatments the shoot was kept under the same 12 h/12 h light–dark cycles at 22°C. Root growth rates were found to be constant when the root-zone environment was kept constant, although the root cooling treatment significantly reduced root growth. Root velocity was decreased after light-on and light-off events of the root illumination treatment, resulting in diel root growth rhythmicity. Despite these changes in root growth, leaf growth was not affected substantially by the root-zone treatments, persistently showing up to three times higher nocturnal growth than diurnal growth. Conclusion GROWMAP-plant allows detailed synchronous growth phenotyping of leaf and root in the same plant. Root growth was very responsive to the root cooling and root illumination, while these treatments altered neither relative growth rate nor diel growth pattern in the seedling leaf. Our results that were obtained simultaneously in growing

  8. Synchronization of Estrus in Cattle: A Review

    Directory of Open Access Journals (Sweden)

    R. Islam

    2011-06-01

    Full Text Available Numbers of estrus synchronization programmes are available in cattle based on the use of various hormones like progesterone, prostaglandin F2a and their various combinations with other hormones like estrogen and Gonadotrophin Releasing hormone (GnRH. Selection of appropriate estrus synchronization protocol should be made on the basis of management capabilities and expectations of the farmer. Synchronization of oestrus can be accomplished with the injection of prostaglandin F2a alone, but it needs proper detection of the ovarian status of the cows as prostaglandin F2a is active in only functional corpus luteum in between 8 to 17 days of estrous cycle. Progesterone may reduce fertility up to 14 percent, but short time progesterone exposure (less than 14 days is beneficial. Addition of GnRH in the Progesterone or Prostaglandin based synchronization programme is helpful for more synchrony in estrus as GnRH may be helpful to synchronize the oestrous cycle in delayed pubertal heifers and post partum cows (Post partum anoestrum and further a single, timed artificial insemination is possible with this method. New methods of synchronizing estrus in which the GnRH-PG protocol is preceded by progesterone treatment offer effective synchronization of estrus with high fertility. [Vet. World 2011; 4(3.000: 136-141

  9. Research on synchronous gear pump

    Institute of Scientific and Technical Information of China (English)

    LUAN Zhen-hui

    2010-01-01

    Based on a comprehensive analysis of the structure and existing problems of the gear pump, provided a structure principle of a synchronous gear pump. The discussions focused on the working principle, construction features and finite element analysis of the hydraulic gear. The research indicates that the new pump has such advantages as lower noise, better distributed flow and a high work pressure, and it can be widely used in hydraulic systems.

  10. 基于数字技术的高精度守时系统%High Precision Time Synchronization System Based on Digital Technology

    Institute of Scientific and Technical Information of China (English)

    邢燕; 陈永奇; 胡永辉

    2014-01-01

    高精密时间频率系统是现代化战争中实现精确打击的基础,而守时工作是精密时间频率系统的基础和核心内容。随着卫星定位定时系统的不断发展,利用远程传输的标准时间信号在本地获取高精度的时间成为一种相对便宜而方便的方法。对与标准时间服务相关的时间同步方法及守时技术进行了研究和分析,并结合工程实际设计了一种10-9量级高精度时间同步和保持系统。测试结果表明,该系统应用效果良好,可广泛应用于通讯、电力、交通和计算机网络时间同步等领域。%High—precision time and frequency system is used as the basis for modern Warfare to a—chieve precision strike, and the punctuality is considered to be the foundation and core of the high—preci—sion time and frequency system. With the development of satellite positioning and timing system, by using the standard time signal remote transmission in the local acquisition of high precision time is used as a cheaper and convenient method. The time synchronization method and a kind of high precision time syn—chronization and time—keeping system are researched in this paper. The test results shoW that the system has good application effects, and it can be Widely used at the time of communication, electric poWer, traffics , computer netWork synchronization and other fields.

  11. Beam Synchronous Timing Systems

    CERN Document Server

    Peters, A

    2003-01-01

    For many beam diagnostics purposes beam synchronous timing systems are needed in addition to the timing systems supplied by the control systems of the different accelerators. The demands and techniques of different accelerator facilities will be discussed along the following aspects: Bunch and macro pulse synchronous timing systems Solutions for different time scales from ps to ms Coupling to the RF and control systems of the different accelerators Electronics for the beam synchronous timing systems: parameters, techniques, controlling Use of industrial products for bunch synchronous timing systems, e.g. function generators Distribution of the timing signals: electronically via cables, optically via fibres or wireless Coupling to and use of timing standards: IRIG-B, GPS, ? The participants should present and describe solutions from their facilities with some transparencies as a starting point for the discussion.

  12. Synchronization of hyperchaotic oscillators

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Cenys, A.; Mykolaitis, G.

    1997-01-01

    Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...

  13. Advanced synchronous luminescence system

    Science.gov (United States)

    Vo-Dinh, Tuan

    1997-01-01

    A method and apparatus for determining the condition of tissue or otherwise making chemical identifications includes exposing the sample to a light source, and using a synchronous luminescence system to produce a spectrum that can be analyzed for tissue condition.

  14. Synchronization in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Arenas, A.; Diaz-Guilera, A.; Moreno, Y.; Zhou, C.; Kurths, J.

    2007-12-12

    Synchronization processes in populations of locally interacting elements are in the focus of intense research in physical, biological, chemical, technological and social systems. The many efforts devoted to understand synchronization phenomena in natural systems take now advantage of the recent theory of complex networks. In this review, we report the advances in the comprehension of synchronization phenomena when oscillating elements are constrained to interact in a complex network topology. We also overview the new emergent features coming out from the interplay between the structure and the function of the underlying pattern of connections. Extensive numerical work as well as analytical approaches to the problem are presented. Finally, we review several applications of synchronization in complex networks to different disciplines: biological systems and neuroscience, engineering and computer science, and economy and social sciences.

  15. Control and synchronization of spatiotemporal chaos.

    Science.gov (United States)

    Ahlborn, Alexander; Parlitz, Ulrich

    2008-01-01

    Chaos control methods for the Ginzburg-Landau equation are presented using homogeneously, inhomogeneously, and locally applied multiple delayed feedback signals. In particular, it is shown that a small number of control cells is sufficient for stabilizing plane waves or for trapping spiral waves, and that successful control is closely connected to synchronization of the dynamics in regions close to the control cells.

  16. Analysis of FDDI synchronous traffic delays

    Science.gov (United States)

    Johnson, Marjory J.

    1988-01-01

    The Fiber Distributed Data Interface (FDDI) high-speed token-ring protocol provides support for two classes of service: synchronous, to support applications which require deterministic access to the channel, and asynchronous, to support applications which do not have such stringent response-time requirements. The purpose of this paper is to determine how to set ring parameters to support synchronous traffic most efficiently. Both theoretical results and results obtained from a simulation study are presented.

  17. Synchronizing Strategies under Partial Observability

    DEFF Research Database (Denmark)

    Larsen, Kim Guldstrand; Laursen, Simon; Srba, Jiri

    2014-01-01

    been intensively studied for systems that do not provide any information about their configurations. In order to capture more general scenarios, we extend the existing theory of synchronizing words to synchronizing strategies, and study the synchronization, short-synchronization and subset...

  18. Analysis of mechanical characteristics of superconducting field coil for 17 MW class high temperature superconducting synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. H.; Park, S. I.; Im, S. H.; Kim, H. M. [Jeju National University, Jeju (Korea, Republic of)

    2013-09-15

    Superconducting field coils using a high-temperature superconducting (HTS) wires with high current density generate high magnetic field of 2 to 5 [T] and electromagnetic force (Lorentz force) acting on the superconducting field coils also become a very strong from the point of view of a mechanical characteristics. Because mechanical stress caused by these powerful electromagnetic force is one of the factors which worsens the critical current performance and structural characteristics of HTS wire, the mechanical stress analysis should be performed when designing the superconducting field coils. In this paper, as part of structural design of superconducting field coils for 17 MW class superconducting ship propulsion motor, mechanical stress acting on the superconducting field coils was analyzed and structural safety was also determined by the coupling analysis system that is consists of commercial electromagnetic field analysis program and structural analysis program.

  19. Synchronous clock stopper for microprocessor

    Science.gov (United States)

    Kitchin, David A. (Inventor)

    1985-01-01

    A synchronous clock stopper circuit for inhibiting clock pulses to a microprocessor in response to a stop request signal, and for reinstating the clock pulses in response to a start request signal thereby to conserve power consumption of the microprocessor when used in an environment of limited power. The stopping and starting of the microprocessor is synchronized, by a phase tracker, with the occurrences of a predetermined phase in the instruction cycle of the microprocessor in which the I/O data and address lines of the microprocessor are of high impedance so that a shared memory connected to the I/O lines may be accessed by other peripheral devices. The starting and stopping occur when the microprocessor initiates and completes, respectively, an instruction, as well as before and after transferring data with a memory. Also, the phase tracker transmits phase information signals over a bus to other peripheral devices which signals identify the current operational phase of the microprocessor.

  20. Modulation of Olfactory Bulb Network Activity by Serotonin: Synchronous Inhibition of Mitral Cells Mediated by Spatially Localized GABAergic Microcircuits

    Science.gov (United States)

    Schmidt, Loren J.; Strowbridge, Ben W.

    2014-01-01

    Although inhibition has often been proposed as a central mechanism for coordinating activity in the olfactory system, relatively little is known about how activation of different inhibitory local circuit pathways can generate coincident inhibition of principal cells. We used serotonin (5-HT) as a pharmacological tool to induce spiking in ensembles…

  1. Cell-Type and State-Dependent Synchronization among Rodent Somatosensory, Visual, Perirhinal Cortex, and Hippocampus CA1

    NARCIS (Netherlands)

    Vinck, M.; Bos, J.J.; van Mourik-Donga, L.A; Oplaat, K.T.; Klein, G.A.; Jackson, J.C.; Gentet, L.J.; Pennartz, C.M.A.

    2015-01-01

    Beta and gamma rhythms have been hypothesized to be involved in global and local coordination of neuronal activity, respectively. Here, we investigated how cells in rodent area S1BF are entrained by rhythmic fluctuations at various frequencies within the local area and in connected areas, and how

  2. Implementation of a sliding-mode-based position sensorless drive for high-speed micro permanent-magnet synchronous motors.

    Science.gov (United States)

    Chi, Wen-Chun; Cheng, Ming-Yang

    2014-03-01

    Due to issues such as limited space, it is difficult if it is not impossible to employ a position sensor in the drive control of high-speed micro PMSMs. In order to alleviate this problem, this paper analyzes and implements a simple and robust position sensorless field-oriented control method of high-speed micro PMSMs based on the sliding-mode observer. In particular, the angular position and velocity of the rotor of the high-speed micro PMSM are estimated using the sliding-mode observer. This observer is able to accurately estimate rotor position in the low speed region and guarantee fast convergence of the observer in the high speed region. The proposed position sensorless control method is suitable for electric dental handpiece motor drives where a wide speed range operation is essential. The proposed sensorless FOC method is implemented using a cost-effective 16-bit microcontroller and tested in a prototype electric dental handpiece motor. Several experiments are performed to verify the effectiveness of the proposed method.

  3. High-pitch dual-source CT angiography of the aortic valve-aortic root complex without ECG-synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Karlo, Christoph; Leschka, Sebastian; Goetti, Robert Paul; Feuchtner, Gudrun; Desbiolles, Lotus; Stolzmann, Paul; Marincek, Borut; Baumueller, Stephan [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Plass, Andre; Falk, Volkmar [University Hospital Zurich, Clinic for Cardiovascular Surgery, Zurich (Switzerland); Alkadhi, Hatem [University Hospital Zurich, Institute of Diagnostic and Interventional Radiology, Zurich (Switzerland); Massachusetts General Hospital, Harvard Medical School, Cardiac MR PET CT Group, Boston, MA (United States)

    2011-01-15

    To compare image quality and radiation dose of high-pitch computed tomography angiography(CTA) of the aortic valve-aortic root complex with and without prospective ECG-gating compared to a retrospectively ECG-gated standard-pitch acquisition. 120 patients(mean age 68 {+-} 13 years) were examined using a 128-slice dual-source CT system using prospectively ECG-gated high-pitch(group A; n = 40), non-ECG-gated high-pitch(group B; n = 40) or retrospectively ECG-gated standard-pitch(C; n = 40) acquisition techniques. Image quality of the aortic root, valve and ascending aorta including the coronary ostia was assessed by two independent readers. Image noise was measured, radiation dose estimates were calculated. Interobserver agreement was good({kappa} = 0.64-0.78). Image quality was diagnostic in 38/40 patients(group A), 37/40(B) and 38/40(C) with no significant difference in number of patients with diagnostic image quality among all groups (p = 0.56). Significantly more patients showed excellent image quality in group A compared to groups B and C(each, p < 0.01). Average image noise was significantly different between all groups(p < 0.05). Mean radiation dose estimates in groups A and B(each; 2.4 {+-} 0.3 mSv) were significantly lower compared to group C(17.5 {+-} 4.4 mSv; p < 0.01). High-pitch dual-source CTA provides diagnostic image quality of the aortic valve-aortic root complex even without ECG-gating at 86% less radiation dose when compared to a standard-pitch ECG-gated acquisition. (orig.)

  4. Experimental Performance Evaluation of a High Speed Permanent Magnet Synchronous Motor and Drive for a Flywheel Application at Different Frequencies

    Science.gov (United States)

    Nagorny, Aleksandr S.; Jansen, Ralph H.; Kankam, M. David

    2007-01-01

    This paper presents the results of an experimental performance characterization study of a high speed, permanent magnet motor/generator (M/G) and drive applied to a flywheel module. Unlike the conventional electric machine the flywheel M/G is not a separated unit; its stator and rotor are integrated into a flywheel assembly. The M/G rotor is mounted on a flywheel rotor, which is magnetically levitated and sealed within a vacuum chamber during the operation. Thus, it is not possible to test the M/G using direct load measurements with a dynamometer and torque transducer. Accordingly, a new in-situ testing method had to be developed. The paper describes a new flywheel M/G and drive performance evaluation technique, which allows the estimation of the losses, efficiency and power quality of the flywheel high speed permanent magnet M/G, while working in vacuum, over wide frequency and torque ranges. This method does not require any hardware modification nor any special addition to the test rig. This new measurement technique is useful for high-speed applications, when applying an external load is technically difficult.

  5. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation.

  6. Synchronization of the CMS Cathode Strip Chambers

    CERN Document Server

    Raknessa, G; Wang, D

    2007-01-01

    The synchronization of the trigger and data acquisition systems for the Cathode Strip Chambers (CSCs) in the Compact Muon Solenoid (CMS) detector at CERN is described. The CSC trigger system is designed to trigger CMS on muons with high efficiency (~99% per chamber) and is able to accurately identify its 25ns proton bunch crossing. To date, asynchronous cosmic ray data have been used to define the protocol and to refine timing algorithms, allowing synchronization to be realized within and between chambers to within ±10 ns. Final synchronization of the CSCs requires timing parameters to be accurate to 2 ns. This goal will be readily achieved from the cosmic ray baseline using data taken with the synchronous beam structure of the Large Hadron Collider.

  7. Implementation of low-swing differential interface circuits for high-speed on-chip synchronous interconnection

    Institute of Scientific and Technical Information of China (English)

    QIAO Fei; YANG HuaZhong; HUANG Gang; WANG Hui

    2008-01-01

    A novel low-swing interface circuit for high-speed on-chip asynchronous inter-connection is proposed in this paper.It takes a differential level-triggered latch to recover digital signal with ultra low-swing voltage less than 50 mV,and the driver part of the interface circuit is optimized for low power using the driver-array method.With a capacity to work up to 500 MHz,the proposed circuit,which is simulated and fabricated using SMIC 0.18-um 1.8-V digital CMOS technology,consumes less power than previously reported designs.

  8. High Efficiency Polymer Solar Cells Technologies

    Institute of Scientific and Technical Information of China (English)

    Abdrhman M G; LI Hang-quan; ZHANG Li-ye; ZHOU Bing

    2006-01-01

    The conjugated polymer-based solar cell is one of the most promising devices in search of sustainable, renewable energy sources in last decade. It is the youngest field in organic solar cell research and also is certainly the fastest growing one at the moment. In addition, the key factor for polymer-based solar cells with high-efficiency is to invent new materials. Organic solar cell has attracted significant researches and commercial interest due to its low cost in fabrication and flexibility in applications. However, they suffer from relatively low conversion efficiency. The summarization of the significance and concept of high efficiency polymer solar cell technologies are presented.

  9. Stabilization of a high-order harmonic generation seeded extreme ultraviolet free electron laser by time-synchronization control with electro-optic sampling

    Institute of Scientific and Technical Information of China (English)

    H.Tomizawa; T.Sato; K.Ogawa; K.Togawa; T.Tanaka; T.Hara; M.Yabashi; H.Tanaka; T.Ishikawa; T.Togashi; S.Matsubara; Y.Okayasu; T.Watanabe; E.J.Takahashi; K.Midorikawa; M.Aoyama; K.Yamakawa; S.Owada; A.Iwasaki; K.Yamanouchi

    2015-01-01

    A fully coherent free electron laser(FEL) seeded with a higher-order harmonic(HH) pulse from high-order harmonic generation(HHG) is successfully operated for a sufficiently prolonged time in pilot user experiments by using a timing drift feedback. For HHG-seeded FELs, the seeding laser pulses have to be synchronized with electron bunches. Despite seeded FELs being non-chaotic light sources in principle, external laser-seeded FELs are often unstable in practice because of a timing jitter and a drift between the seeding laser pulses and the accelerated electron bunches. Accordingly,we constructed a relative arrival-timing monitor based on non-invasive electro-optic sampling(EOS). The EOS monitor made uninterrupted shot-to-shot monitoring possible even during the seeded FEL operation. The EOS system was then used for arrival-timing feedback with an adjustability of 100 fs for continual operation of the HHG-seeded FEL. Using the EOS-based beam drift controlling system, the HHG-seeded FEL was operated over half a day with an effective hit rate of 20%–30%. The output pulse energy was 20 μJ at the 61.2 nm wavelength. Towards seeded FELs in the water window region, we investigated our upgrade plan to seed high-power FELs with HH photon energy of 30–100 e V and lase at shorter wavelengths of up to 2 nm through high-gain harmonic generation(HGHG) at the energy-upgraded SPring-8Compact SASE Source(SCSS) accelerator. We studied a benefit as well as the feasibility of the next HHG-seeded FEL machine with single-stage HGHG with tunability of a lasing wavelength.

  10. Microarray and synchronization of neuronal differentiation with pathway changes in the Kyoto Encyclopedia of Genes and Genomes (KEGG) databank in nerve growth factor-treated PC12 cells.

    Science.gov (United States)

    Lin, Chih-Ming; Feng, Wayne

    2012-08-01

    The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database creates networks from interrelations between molecular biology and underlying chemical elements. This allows for analysis of biologic networks, genomic information, and higher-order functional information at a systems level. We performed microarray experiments and used the KEGG database, systems biology analysis, and annotation of pathway function to study nerve growth factor (NGF)-induced differentiation of PC12 cells. Cells were cultured to 70%-80% confluence, treated with NGF for 1 or 3 hours (h), and RNA was extracted. Stage 1 data analysis involved analysis of variance (ANOVA), and stage 2 involved cluster analysis and heat map generation. We identified 2020 NGF-induced PC12 genes (1038 at 1 h and 1554 at 3 h). Results showed changes in gene expression over time. We compared these genes with 6035 genes from the KEGG database. Cross-matching resulted in 830 genes. Among these, we identified 395 altered genes (155 at 1 h and 301 at 3 h; 2-fold increase from 1 h to 3 h). We identified 191 biologic pathways in the KEGG database; the top 15 showed correlations with neuronal differentiation (mitogen-activated protein kinase [MAPK] pathway: 35 genes at 1 h, 54 genes at 3 h; genes associated with axonal guidance: 12 at 1 h, 26 at 3 h; Wnt pathway: 16 at 1 h, 25 at 3 h; neurotrophin pathway: 4 at 1 h, 14 at 3 h). Thus, we identified changes in neuronal differentiation pathways with the KEGG database, which were synchronized with NGF-induced differentiation.

  11. High rate, high reliability Li/SO2 cells

    Science.gov (United States)

    Chireau, R.

    1982-03-01

    The use of the lithium/sulfur dioxide system for aerospace applications is discussed. The high rate density in the system is compared to some primary systems: mercury zinc, silver zinc, and magnesium oxide. Estimates are provided of the storage life and shelf life of typical lithium sulfur batteries. The design of lithium cells is presented and criteria are given for improving the output of cells in order to achieve high rate and high reliability.

  12. Electrotonic vascular signal conduction and nephron synchronization.

    Science.gov (United States)

    Marsh, Donald J; Toma, Ildiko; Sosnovtseva, Olga V; Peti-Peterdi, Janos; Holstein-Rathlou, Niels-Henrik

    2009-04-01

    Tubuloglomerular feedback (TGF) and the myogenic mechanism control afferent arteriolar diameter in each nephron and regulate blood flow. Both mechanisms generate self-sustained oscillations, the oscillations interact, TGF modulates the frequency and amplitude of the myogenic oscillation, and the oscillations synchronize; a 5:1 frequency ratio is the most frequent. TGF oscillations synchronize in nephron pairs supplied from a common cortical radial artery, as do myogenic oscillations. We propose that electrotonic vascular signal propagation from one juxtaglomerular apparatus interacts with similar signals from other nephrons to produce synchronization. We tested this idea in tubular-vascular preparations from mice. Vascular smooth muscle cells were loaded with a fluorescent voltage-sensitive dye; fluorescence intensity was measured with confocal microscopy. Perfusion of the thick ascending limb activated TGF and depolarized afferent arteriolar smooth muscle cells. The depolarization spread to the cortical radial artery and other afferent arterioles and declined with distance from the perfused juxtaglomerular apparatus, consistent with electrotonic vascular signal propagation. With a mathematical model of two coupled nephrons, we estimated the conductance of nephron coupling by fitting simulated vessel diameters to experimental data. With this value, we simulated nephron pairs to test for synchronization. In single-nephron simulations, the frequency of the TGF oscillation varied with nephron length. Coupling nephrons of different lengths forced TGF frequencies of both pair members to converge to a common value. The myogenic oscillations also synchronized, and the synchronization between the TGF and the myogenic oscillations showed an increased stability against parameter perturbations. Electronic vascular signal propagation is a plausible mechanism for nephron synchronization. Coupling increased the stability of the various oscillations.

  13. Nonlinear frequency-dependent synchronization in the developing hippocampus.

    Science.gov (United States)

    Prida, L M; Sanchez-Andres, J V

    1999-07-01

    Synchronous population activity is present both in normal and pathological conditions such as epilepsy. In the immature hippocampus, synchronous bursting is an electrophysiological conspicuous event. These bursts, known as giant depolarizing potentials (GDPs), are generated by the synchronized activation of interneurons and pyramidal cells via GABAA, N-methyl-D-aspartate, and AMPA receptors. Nevertheless the mechanism leading to this synchronization is still controversial. We have investigated the conditions under which synchronization arises in developing hippocampal networks. By means of simultaneous intracellular recordings, we show that GDPs result from local cooperation of active cells within an integration period prior to their onset. During this time interval, an increase in the number of excitatory postsynaptic potentials (EPSPs) takes place building up full synchronization between cells. These EPSPs are correlated with individual action potentials simultaneously occurring in neighboring cells. We have used EPSP frequency as an indicator of the neuronal activity underlying GDP generation. By comparing EPSP frequency with the occurrence of synchronized GDPs between CA3 and the fascia dentata (FD), we found that GDPs are fired in an all-or-none manner, which is characterized by a specific threshold of EPSP frequency from which synchronous GDPs emerge. In FD, the EPSP frequency-threshold for GDP onset is 17 Hz. GDPs are triggered similarly in CA3 by appropriate periodic stimulation of mossy fibers. The frequency threshold for CA3 GDP onset is 12 Hz. These findings clarify the local mechanism of synchronization underlying bursting in the developing hippocampus, indicating that GDPs are fired when background levels of EPSPs or action potentials have built up full synchronization by firing at specific frequencies (>12 Hz). Our results also demonstrate that spontaneous EPSPs and action potentials are important for the initiation of synchronous bursts in the

  14. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    The large scale integration of renewable energy sources requires suitable energy storage systems to balance energy production and demand in the electrical grid. Bidirectional fuel cells are an attractive technology for energy storage systems due to the high energy density of fuel. Compared...... entitled "High Efficiency Reversible Fuel Cell Power Converter" and it presents the design of a high efficiency dc-dc converter developed and optimized for bidirectional fuel cell applications. First, a brief overview of fuel cell and energy storage technologies is presented. Different system topologies...... to traditional unidirectional fuel cell, bidirectional fuel cells have increased operating voltage and current ranges. These characteristics increase the stresses on dc-dc and dc-ac converters in the electrical system, which require proper design and advanced optimization. This work is part of the PhD project...

  15. Measure Synchronization on Symplectic Map

    Institute of Scientific and Technical Information of China (English)

    CHEN Shao-Ying; XU Hai-Bo; WANG Guang-Rui; CHEN Shi-Gang

    2004-01-01

    Measure synchronization in coupled Hamiltonian systems is a novel synchronization phenomenon. The measure synchronization on symplectic map is observed numerically, for identical coupled systems with different parameters. We have found the properties of the characteristic frequency and the amplitude of phase locking in regular motion when the measure synchronization of coupled systems is obtained. The relations between the change of the largest Lyapunov exponent and the course of phase desynchronization are also discussed in coupled systems, some useful results are obtained. A new approach is proposed for describing the measure synchronization of coupled systems numerically,which is advantage in judging the measure synchronization, especially for the coupled systems in nonregular region.

  16. Synchronization and Inertial Frames

    CERN Document Server

    Viazminsky, C P

    1999-01-01

    In classical mechanics, a procedure for simultaneous synchronization in all inertial frames is consistent with the Galilean transformation. However, if one attempts to achieve such a synchronization utilizing light signals, he will be facing in the first place the break down of simultaneity, and secondly, a self-contradictory transformation that has the Lorentz transformation, or its confinement to the velocity of light, as the only possible ways that resolve the contradiction. The current work constitutes a smooth transition from traditional to relativistic vision of mechanics, and therefore is quite appealing from pedagogical point of view.

  17. Analysis of synchronous machines

    CERN Document Server

    Lipo, TA

    2012-01-01

    Analysis of Synchronous Machines, Second Edition is a thoroughly modern treatment of an old subject. Courses generally teach about synchronous machines by introducing the steady-state per phase equivalent circuit without a clear, thorough presentation of the source of this circuit representation, which is a crucial aspect. Taking a different approach, this book provides a deeper understanding of complex electromechanical drives. Focusing on the terminal rather than on the internal characteristics of machines, the book begins with the general concept of winding functions, describing the placeme

  18. BEACON SYNCHRONIZATION TECHNOLOGY FOR “BEIDOU” TERRESTRIAL IMPROVEMENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WEIJin-chen; TANGJi-qiang; SHENFeng

    2005-01-01

    Synchronization is an essential technology in the radio navigation system. The technique for improving the “Beidou” positioning ability is presented through constituting the terrestrial improvement system, and the beacon synchronization of the improvement system with the “Beidou” one-way time transfer model is realized.The direct digital synthesis (DDS) is adopted to generate the pseudo-random code clock having high precision and stability. Meanwhile, the CPLD device is used to design the synchronization pulse picking-up module, the spread spectrum PN code generator and the spread spectrum modulator. Measurement results indicate that the beacon synchronization has the high precision and the stability.

  19. Effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation

    Institute of Scientific and Technical Information of China (English)

    Jing Liu; Yi Gao; Shuan Wang; Er-Wei Sun; Yu Wang; Zhi Zhang; Yi-Qiang Shan; Shi-Zheng Zhong

    2005-01-01

    AIM: To study effect of operation-synchronizing transfusion of apoptotic spleen cells from donor rats on acute rejection of recipient rats after liver transplantation.METHODS: Two of Wistar rats were chosen randomly for normal liver pathology control and ten of SD rats chosen randomly for liver function control as blank group (no operation). The rest of Wistar and SD rats were divided into four groups: control group (only liver transplantation),Dex group (donors receiving intraperitoneal injection of dexamethasone), SpC group (recipients receiving infusion of spleen cells of donors), Dex-SpC group (recipients receiving infusion of apoptotic spleen cells of donors),with each group except blank group, containing 10 SD rats and 10 Wistar rats, respectively. Wistar rats received liver transplantation from SD rats, in the meantime they received infusion of spleen cells of donors, which were induced by an intraperitoneal injection of dexamethasone The serum alanine transaminase (ALT), total bilirubin (T bili), liver pathological changes and survival time were analysed. Statistical analysis was carried out using SPSS 10.0 for Windows. Differences of the parametric data of ALT in means were examined by one-way ANOVA.Differences of ALT between two groups were examined by LSD. Differences of the nonparametric data of T bili in means and scores of pathology classification for acute rejection were examined by Kruskal-Willis H test. The correlations between ALT and T bili were analysed by Bivariate. Kaplan-Meier curves were used to demonstrate survival distribution. The log-rank test was used to compare the survival data.RESULTS: There were significant differences in ALT of the five groups (F= 23.164 P= 0.000), and ALT in DexSpC group was significantly higher than that in blank control, control, Dex, and SpC groups (P = 0.000), and ALT in SpC group was significantly higher than that in blank control (P = 0.000), control (P = 0.004), and Dex groups (P = 0.02). Results of

  20. A novel high reliability CMOS SRAM cell

    Institute of Scientific and Technical Information of China (English)

    Xie Chengmin; Wang Zhongfang; Wu Longsheng; Liu Youbao

    2011-01-01

    A novel 8T single-event-upset (SEU) hardened and high static noise margin (SNM) SRAM cell is proposed.By adding one transistor paralleled with each access transistor,the drive capability of pull-up PMOS is greater than that of the conventional cell and the read access transistors are weaker than that of the conventional cell.So the hold,read SNM and critical charge increase greatly.The simulation results show that the critical charge is almost three times larger than that of the conventional 6T cell by appropriately sizing the pull-up transistors.The hold and read SNM of the new cell increase by 72% and 141.7%,respectively,compared to the 6T design,but it has a 54% area overhead and read performance penalty.According to these features,this novel cell suits high reliability applications,such as aerospace and military.

  1. Synchronized turbo apoptosis induced by cold-shock

    Science.gov (United States)

    Fransen, J. H.; Dieker, J. W.; Hilbrands, L. B.; Berden, J. H.

    2010-01-01

    In our research on the role of apoptosis in the pathogenesis of the autoimmune disease systemic lupus erythematosus (SLE), we aim to evaluate the effects of early and late apoptotic cells and blebs on antigen presenting cells. This requires the in vitro generation of sufficiently large and homogeneous populations of early and late apoptotic cells. Here, we present a quick method encountered by serendipity that results in highly reproducible synchronized homogeneous apoptotic cell populations. In brief, granulocytic 32Dcl3 cells are incubated on ice for 2 h and subsequently rewarmed at 37°C. After 30–90 min at 37°C more than 80–90% of the cells become early apoptotic (Annexin V positive/propidium iodide negative). After 24 h of rewarming at 37°C 98% of the cells were late apoptotic (secondary necrotic; Annexin V positive/propidium iodide positive). Cells already formed apoptotic blebs at their cell surface after approximately 20 min at 37°C. Inter-nucleosomal chromatin cleavage and caspase activation were other characteristics of this cold-shock-induced process of apoptosis. Consequently, apoptosis could be inhibited by a caspase inhibitor. Finally, SLE-derived anti-chromatin autoantibodies showed a high affinity for apoptotic blebs generated by cold-shock. Overall, cold-shock induced apoptosis is achieved without the addition of toxic compounds or antibodies, and quickly leads to synchronized homogeneous apoptotic cell populations, which can be applied for various research questions addressing apoptosis. PMID:20972831

  2. Synchronizing Hyperchaotic Circuits

    DEFF Research Database (Denmark)

    Tamasevicius, Arunas; Cenys, Antanas; Namajunas, Audrius

    1997-01-01

    Regarding possible applications to secure communications the technique of synchronizing hyperchaotic circuits with a single dynamical variable is discussed. Several specific examples including the fourth-order circuits with two positive Lyapunov exponents as well as the oscillator with a delay line...... characterized by multiple positive Lyapunov exponents are reviewd....

  3. Synchronization of respiration

    NARCIS (Netherlands)

    Garssen, B.

    In order to study synchronization of respiration, three different videofragments were presented to 21 normal subjects. Each fragment showed a ‘therapeutic interview’ specially performed for this purpose, with a ‘patient’ breathing in a particular way. The respiration of model 1 was deep, slow and

  4. Optimized high gradient magnetic separation for isolation of Plasmodium-infected red blood cells

    Directory of Open Access Journals (Sweden)

    Chimma Pattamawan

    2010-02-01

    Full Text Available Abstract Background Highly purified infected red blood cells (irbc, or highly synchronized parasite cultures, are regularly required in malaria research. Conventional isolation and synchronization rely on density and osmotic fragility of irbc, respectively. High gradient magnetic separation (HGMS offers an alternative based on intrinsic magnetic properties of irbc, avoiding exposure to chemicals and osmotic stress. Successful HGMS concentration in malaria research was previously reported using polymer coated columns, while HGMS depletion has not been described yet. This study presents a new approach to both HGMS concentration and depletion in malaria research, rendering polymer coating unnecessary. Methods A dipole magnet generating a strong homogenous field was custom assembled. Polypropylene syringes were fitted with one-way stopcocks and filled with stainless steel wool. Rbc from Plasmodium falciparum cultures were resuspended in density and viscosity optimized HGMS buffers and HGMS processed. Purification and depletion results were analysed by flow cytometer and light microscopy. Viability was evaluated by calculating the infection rate after re-culturing of isolates. Results In HGMS concentration, purity of irbc isolates from asynchronous cultures consistently ranged from 94.8% to 98.4% (mean 95.7%. With further optimization, over 90% of isolated irbc contained segmented schizonts. Processing time was less than 45 min. Reinfection rates ranged from 21.0% to 56.4%. In HGMS depletion, results were comparable to treatment with sorbitol, as demonstrated by essentially identical development of cultures. Conclusion The novel HGMS concentration procedure achieves high purities of segmented stage irbc from standard asynchronous cultures, and is the first HGMS depletion alternative to sorbitol lysis. It represents a simple and highly efficient alternative to conventional irbc concentration and synchronization methods.

  5. Optimized high gradient magnetic separation for isolation of Plasmodium-infected red blood cells.

    Science.gov (United States)

    Bhakdi, Sebastian C; Ottinger, Annette; Somsri, Sangdao; Sratongno, Panudda; Pannadaporn, Peeranad; Chimma, Pattamawan; Malasit, Prida; Pattanapanyasat, Kovit; Neumann, Hartmut P H

    2010-02-02

    Highly purified infected red blood cells (irbc), or highly synchronized parasite cultures, are regularly required in malaria research. Conventional isolation and synchronization rely on density and osmotic fragility of irbc, respectively. High gradient magnetic separation (HGMS) offers an alternative based on intrinsic magnetic properties of irbc, avoiding exposure to chemicals and osmotic stress. Successful HGMS concentration in malaria research was previously reported using polymer coated columns, while HGMS depletion has not been described yet. This study presents a new approach to both HGMS concentration and depletion in malaria research, rendering polymer coating unnecessary. A dipole magnet generating a strong homogenous field was custom assembled. Polypropylene syringes were fitted with one-way stopcocks and filled with stainless steel wool. Rbc from Plasmodium falciparum cultures were resuspended in density and viscosity optimized HGMS buffers and HGMS processed. Purification and depletion results were analysed by flow cytometer and light microscopy. Viability was evaluated by calculating the infection rate after re-culturing of isolates. In HGMS concentration, purity of irbc isolates from asynchronous cultures consistently ranged from 94.8% to 98.4% (mean 95.7%). With further optimization, over 90% of isolated irbc contained segmented schizonts. Processing time was less than 45 min. Reinfection rates ranged from 21.0% to 56.4%. In HGMS depletion, results were comparable to treatment with sorbitol, as demonstrated by essentially identical development of cultures. The novel HGMS concentration procedure achieves high purities of segmented stage irbc from standard asynchronous cultures, and is the first HGMS depletion alternative to sorbitol lysis. It represents a simple and highly efficient alternative to conventional irbc concentration and synchronization methods.

  6. 双电弧共熔池埋弧焊数字化协同控制系统%Digital Synchronic Control System for Twin-arc Co-pool High Speed Submerged Arc Weld(SAW)

    Institute of Scientific and Technical Information of China (English)

    何宽芳; 黄石生; 李学军; 肖冬明

    2011-01-01

    A digital synchronic control system for twin-arc high-speed SAM was presented by IPC(industrial personal computer) and PLC. By adopting the way of software programming, the functions of parameters optimization settings, digital control for the timing of twin arc-starting and arc-ending were achieved, which was to achieve precise control of arc energy parameters and to guarantee stability of synchronic control among the arcs. The design of hardware and software of the digital synchronic control system was also discussed. The results of weld experiments demonstrate that the developed digital synchronic control system meets the design requirements. The process of the twin-arc high speed SAW are stable, perfect forming of weld seam, which achieves technology of twin- arc high- speed SAW.%应用工控机和PLC建立了双电弧共熔池埋弧焊数字化协同控制系统.采用软件的方式实现了双电弧埋弧焊工艺参数的优化设置、两电弧起弧和收弧的时序数字化控制,从而实现了电弧能量参数的精密控制,保证了双电弧之间的协同稳定工作.阐述了数字化协同控制系统的软硬件设计.双电弧高速埋弧焊试验结果表明,所设计的数字化协同控制系统满足设计要求,焊接过程稳定、焊缝成形美观,能实现良好的双电弧高速埋弧焊工艺.

  7. Achieving High Performance Perovskite Solar Cells

    Science.gov (United States)

    Yang, Yang

    2015-03-01

    Recently, metal halide perovskite based solar cell with the characteristics of rather low raw materials cost, great potential for simple process and scalable production, and extreme high power conversion efficiency (PCE), have been highlighted as one of the most competitive technologies for next generation thin film photovoltaic (PV). In UCLA, we have realized an efficient pathway to achieve high performance pervoskite solar cells, where the findings are beneficial to this unique materials/devices system. Our recent progress lies in perovskite film formation, defect passivation, transport materials design, interface engineering with respect to high performance solar cell, as well as the exploration of its applications beyond photovoltaics. These achievements include: 1) development of vapor assisted solution process (VASP) and moisture assisted solution process, which produces perovskite film with improved conformity, high crystallinity, reduced recombination rate, and the resulting high performance; 2) examination of the defects property of perovskite materials, and demonstration of a self-induced passivation approach to reduce carrier recombination; 3) interface engineering based on design of the carrier transport materials and the electrodes, in combination with high quality perovskite film, which delivers 15 ~ 20% PCEs; 4) a novel integration of bulk heterojunction to perovskite solar cell to achieve better light harvest; 5) fabrication of inverted solar cell device with high efficiency and flexibility and 6) exploration the application of perovskite materials to photodetector. Further development in film, device architecture, and interfaces will lead to continuous improved perovskite solar cells and other organic-inorganic hybrid optoelectronics.

  8. Planar multijunction high voltage solar cells

    Science.gov (United States)

    Evans, J. C., Jr.; Chai, A. T.; Goradia, C.

    1980-01-01

    Technical considerations, preliminary results, and fabrication details are discussed for a family of high-voltage planar multi-junction (PMJ) solar cells which combine the attractive features of planar cells with conventional or interdigitated back contacts and the vertical multijunction (VMJ) solar cell. The PMJ solar cell is internally divided into many voltage-generating regions, called unit cells, which are internally connected in series. The key to obtaining reasonable performance from this device was the separation of top surface field regions over each active unit cell. Using existing solar cell fabricating methods, output voltages in excess of 20 volts per linear centimeter are possible. Analysis of the new device is complex, and numerous geometries are being studied which should provide substantial benefits in both normal sunlight usage as well as with concentrators.

  9. Different Responses of Two Highly Permissive Cell Lines Upon HCV Infection

    Institute of Scientific and Technical Information of China (English)

    Honghe Chen; Rongjuan Pei; Xinwen Chen

    2013-01-01

    The construction of the first infectious clone JFH-1 speeds up the research on hepatitis C virus (HCV).However,Huh7 cell line was the only highly permissive cell line for HCV infection and only a few clones were fully permissive.In this study,two different fully permissive clones of Huh7 cells,Huh7.5.1 and Huh7-Lunet-CD81 (Lunet-CD81) cells were compared for their responses upon HCV infection.The virus replication level was found slightly higher in Huh7.5.1 cells than that in Lunet-CD81 cells.Viability of Huh7.5.1 cells but not of Lunet-CD81 cells was reduced significantly after HCV infection.Further analysis showed that the cell cycle of infected Huh7.5.1 cells was arrested at G1 phase.The G1/S transition was blocked by HCV infection in Huh7.5.1 cells as shown by the cell cycle synchronization analysis.Genes related to cell cycle regulation was modified by HCV infection and gene interaction analysis in GeneSpring GX in Direct Interactions mode highlighted 31 genes.In conclusion,the responses of those two cell lines were different upon HCV infection.HCV infection blocked G1/S transition and cell cycle progress,thus reduced the cell viability in Huh7.5.1 cells but not in Lunet-CD81 cells.Lunet-CD81 cells might be suitable for long term infection studies of HCV.

  10. Very High Efficiency Solar Cell Modules

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, A.; Kirkpatrick, D.; Honsberg, C.; Moore, D.; Wanlass, M.; Emery, K.; Schwartz, R.; Carlson, D.; Bowden, S.; Aiken, D.; Gray, A.; Kurtz, S.; Kazmerski, L., et al

    2009-01-01

    The Very High Efficiency Solar Cell (VHESC) program is developing integrated optical system - PV modules for portable applications that operate at greater than 50% efficiency. We are integrating the optical design with the solar cell design, and have entered previously unoccupied design space. Our approach is driven by proven quantitative models for the solar cell design, the optical design, and the integration of these designs. Optical systems efficiency with an optical efficiency of 93% and solar cell device results under ideal dichroic splitting optics summing to 42.7 {+-} 2.5% are described.

  11. Synchronized fission yeast meiosis using an ATP analog-sensitive Pat1 protein kinase.

    Science.gov (United States)

    Cipak, Lubos; Polakova, Silvia; Hyppa, Randy W; Smith, Gerald R; Gregan, Juraj

    2014-01-01

    Synchronous cultures are often indispensable for studying meiosis. Here we present an optimized protocol for induction of synchronous meiosis in the fission yeast Schizosaccharomyces pombe. Chemical inactivation of an ATP analog-sensitive form of the Pat1 kinase (pat1-as2) by adding the ATP analog 1-NM-PP1 in G1-arrested cells allows the induction of synchronous meiosis at optimal temperature (25°C). Importantly, this protocol eliminates detrimental effects of elevated temperature (34°C), which is required to inactivate the commonly used temperature-sensitive Pat1 kinase mutant (pat1-114). The addition of the mat-Pc gene to a mat1-M strain further improves chromosome segregation and spore viability. Thus, our protocol offers highly synchronous meiosis at optimal temperature, with most characteristics similar to those of wild-type meiosis. The synchronization protocol can be completed in 5 d (not including strain production, which may take as long as 2 or 3 months).

  12. Hydrodynamic Cell Trapping for High Throughput Single-Cell Applications

    Directory of Open Access Journals (Sweden)

    Amin Abbaszadeh Banaeiyan

    2013-12-01

    Full Text Available The possibility to conduct complete cell assays under a precisely controlled environment while consuming minor amounts of chemicals and precious drugs have made microfluidics an interesting candidate for quantitative single-cell studies. Here, we present an application-specific microfluidic device, cellcomb, capable of conducting high-throughput single-cell experiments. The system employs pure hydrodynamic forces for easy cell trapping and is readily fabricated in polydimethylsiloxane (PDMS using soft lithography techniques. The cell-trapping array consists of V-shaped pockets designed to accommodate up to six Saccharomyces cerevisiae (yeast cells with the average diameter of 4 μm. We used this platform to monitor the impact of flow rate modulation on the arsenite (As(III uptake in yeast. Redistribution of a green fluorescent protein (GFP-tagged version of the heat shock protein Hsp104 was followed over time as read out. Results showed a clear reverse correlation between the arsenite uptake and three different adjusted low = 25 nL min−1, moderate = 50 nL min−1, and high = 100 nL min−1 flow rates. We consider the presented device as the first building block of a future integrated application-specific cell-trapping array that can be used to conduct complete single cell experiments on different cell types.

  13. High Radiation Resistance IMM Solar Cell

    Science.gov (United States)

    Pan, Noren

    2015-01-01

    Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.

  14. Stability of synchronization clusters and seizurability in temporal lobe epilepsy.

    Directory of Open Access Journals (Sweden)

    Agostina Palmigiano

    Full Text Available PURPOSE: Identification of critical areas in presurgical evaluations of patients with temporal lobe epilepsy is the most important step prior to resection. According to the "epileptic focus model", localization of seizure onset zones is the main task to be accomplished. Nevertheless, a significant minority of epileptic patients continue to experience seizures after surgery (even when the focus is correctly located, an observation that is difficult to explain under this approach. However, if attention is shifted from a specific cortical location toward the network properties themselves, then the epileptic network model does allow us to explain unsuccessful surgical outcomes. METHODS: The intraoperative electrocorticography records of 20 patients with temporal lobe epilepsy were analyzed in search of interictal synchronization clusters. Synchronization was analyzed, and the stability of highly synchronized areas was quantified. Surrogate data were constructed and used to statistically validate the results. Our results show the existence of highly localized and stable synchronization areas in both the lateral and the mesial areas of the temporal lobe ipsilateral to the clinical seizures. Synchronization areas seem to play a central role in the capacity of the epileptic network to generate clinical seizures. Resection of stable synchronization areas is associated with elimination of seizures; nonresection of synchronization clusters is associated with the persistence of seizures after surgery. DISCUSSION: We suggest that synchronization clusters and their stability play a central role in the epileptic network, favoring seizure onset and propagation. We further speculate that the stability distribution of these synchronization areas would differentiate normal from pathologic cases.

  15. Synchronization in networks with multiple interaction layers

    CERN Document Server

    del Genio, Charo I; Bonamassa, Ivan; Boccaletti, Stefano

    2016-01-01

    The structure of many real-world systems is best captured by networks consisting of several interaction layers. Understanding how a multi-layered structure of connections affects the synchronization properties of dynamical systems evolving on top of it is a highly relevant endeavour in mathematics and physics, and has potential applications to several societally relevant topics, such as power grids engineering and neural dynamics. We propose a general framework to assess stability of the synchronized state in networks with multiple interaction layers, deriving a necessary condition that generalizes the Master Stability Function approach. We validate our method applying it to a network of R\\"ossler oscillators with a double layer of interactions, and show that highly rich phenomenology emerges. This includes cases where the stability of synchronization can be induced even if both layers would have individually induced unstable synchrony, an effect genuinely due to the true multi-layer structure of the interact...

  16. Synchronous Characterization of Semiconductor Microcavity Laser Beam

    CERN Document Server

    Wang, Tao

    2015-01-01

    We report on a high-resolution double-channel imaging method used to synchronously map the intensity- and optical-frequency-distribution of a laser beam in the plane orthogonal to the propagation direction. The synchronous measurement allows us to show that the laser frequency is an inhomogeneous distribution below threshold, but that it becomes homogeneous across the fundamental Gaussian mode above threshold. The beam's tails deviations from the Gaussian shape, however, are accompanied by sizeable fluctuations in the laser wavelength, possibly deriving from manufacturing details and from the influence of spontaneous emission in the very low intensity wings. In addition to the synchronous spatial characterization, a temporal analysis at any given point in the beam cross-section is carried out. Using this method, the beam homogeneity and spatial shape, energy density, energy center and the defects-related spectrum can also be extracted from these high-resolution pictures.

  17. The lack of synchronization between iron uptake and cell growth leads to iron overload in Saccharomyces cerevisiae during post-exponential growth modes.

    Science.gov (United States)

    Park, Jinkyu; McCormick, Sean P; Chakrabarti, Mrinmoy; Lindahl, Paul A

    2013-12-31

    Fermenting cells growing exponentially on rich (YPAD) medium underwent a transition to a slow-growing state as glucose levels declined and their metabolism shifted to respiration. During exponential growth, Fe import and cell-growth rates were matched, affording an approximately invariant cellular Fe concentration. During the transition period, the high-affinity Fe import rate declined slower than the cell-growth rate declined, causing Fe to accumulate, initially as Fe(III) oxyhydroxide nanoparticles but eventually as mitochondrial and vacuolar Fe. Once the cells had reached slow-growth mode, Fe import and cell-growth rates were again matched, and the cellular Fe concentration was again approximately invariant. Fermenting cells grown on minimal medium (MM) grew more slowly during the exponential phase and underwent a transition to a true stationary state as glucose levels declined. The Fe concentration of MM cells that just entered the stationary state was similar to that of YPAD cells, but MM cells continued to accumulate Fe in the stationary state. Fe initially accumulated as nanoparticles and high-spin Fe(II) species, but vacuolar Fe(III) also eventually accumulated. Surprisingly, Fe-packed 5-day-old MM cells suffered no more reactive oxygen species (ROS) damage than younger cells, suggesting that the Fe concentration alone does not accurately predict the extent of ROS damage. The mode and rate of growth at the time of harvesting dramatically affected cellular Fe content. A mathematical model of Fe metabolism in a growing cell was developed. The model included the import of Fe via a regulated high-affinity pathway and an unregulated low-affinity pathway. The import of Fe from the cytosol to vacuoles and mitochondria and nanoparticle formation were also included. The model captured essential trafficking behavior, demonstrating that cells regulate Fe import in accordance with their overall growth rate and that they misregulate Fe import when nanoparticles

  18. Synchronously deployable truss structure

    Science.gov (United States)

    Bush, H. G. (Inventor); Mikulas, M., Jr. (Inventor); Wallsom, E. (Inventor)

    1986-01-01

    A collapsible-expandable truss structure, including first and second spaced surface truss layers having an attached core layer is described. The surface truss layers are composed of a plurality of linear struts arranged in multiple triangular configurations. Each linear strut is hinged at the center and hinge connected at each end to a nodular joint. A passive spring serves as the expansion force to move the folded struts from a stowed collapsed position to a deployed operative final truss configuration. A damper controls the rate of spring expansion for the synchronized deployment of the truss as the folded configuration is released for deployment by the restrain belts. The truss is synchronously extended under the control of motor driven spools.

  19. LHC synchronization test successful

    CERN Multimedia

    The synchronization of the LHC's clockwise beam transfer system and the rest of CERN's accelerator chain was successfully achieved last weekend. Tests began on Friday 8 August when a single bunch of a few particles was taken down the transfer line from the SPS accelerator to the LHC. After a period of optimization, one bunch was kicked up from the transfer line into the LHC beam pipe and steered about 3 kilometres around the LHC itself on the first attempt. On Saturday, the test was repeated several times to optimize the transfer before the operations group handed the machine back for hardware commissioning to resume on Sunday. The anti-clockwise synchronization systems will be tested over the weekend of 22 August.Picture:http://lhc-injection-test.web.cern.ch/lhc-injection-test/

  20. Synchronization of micromasers

    Science.gov (United States)

    Davis-Tilley, C.; Armour, A. D.

    2016-12-01

    We investigate synchronization effects in quantum self-sustained oscillators theoretically using the micromaser as a model system. We use the probability distribution for the relative phase as a tool for quantifying the emergence of preferred phases when two micromasers are coupled together. Using perturbation theory, we show that the behavior of the phase distribution is strongly dependent on exactly how the oscillators are coupled. In the quantum regime where photon occupation numbers are low we find that, although synchronization effects are rather weak, they are nevertheless significantly stronger than expected from a semiclassical description of the phase dynamics. We also compare the behavior of the phase distribution with the mutual information of the two oscillators and show that they can behave in rather different ways.

  1. Heat transparent high intensity high efficiency solar cell

    Science.gov (United States)

    Evans, J. C., Jr. (Inventor)

    1982-01-01

    An improved solar cell design is described. A surface of each solar cell has a plurality of grooves. Each groove has a vertical face and a slanted face that is covered by a reflecting metal. Light rays are reflected from the slanted face through the vertical face where they traverse a photovoltaic junction. As the light rays travel to the slanted face of an adjacent groove, they again traverse the junction. The underside of the reflecting coating directs the light rays toward the opposite surface of solar cell as they traverse the junction again. When the light rays travel through the solar cell and reach the saw toothed grooves on the under side, the process of reflection and repeatedly traversing the junction again takes place. The light rays ultimately emerge from the solar cell. These solar cells are particularly useful at very high levels of insolation because the infrared or heat radiation passes through the cells without being appreciably absorbed to heat the cell.

  2. Adaptive Control Algorithm of the Synchronous Generator

    Directory of Open Access Journals (Sweden)

    Shevchenko Victor

    2017-01-01

    Full Text Available The article discusses the the problem of controlling a synchronous generator, namely, maintaining the stability of the control object in the conditions of occurrence of noise and disturbances in the regulatory process. The model of a synchronous generator is represented by a system of differential equations of Park-Gorev, where state variables are computed relative to synchronously rotating d, q-axis. Management of synchronous generator is proposed to organize on the basis of the position-path control using algorithms to adapt with the reference model. Basic control law directed on the stabilizing indicators the frequency generated by the current and the required power level, which is achieved by controlling the mechanical torque on the shaft of the turbine and the value of the excitation voltage of the synchronous generator. Modification of the classic adaptation algorithm using the reference model, allowing to minimize the error of the reference regulation and the model under investigation within the prescribed limits, produced by means of the introduction of additional variables controller adaptation in the model. Сarried out the mathematical modeling of control provided influence on the studied model of continuous nonlinear and unmeasured the disturbance. Simulation results confirm the high level accuracy of tracking and adaptation investigated model with respect to the reference, and the present value of the loop error depends on parameters performance of regulator.

  3. Interaction between different cells in an olfactory bulb and synchronous kinematic analysis%嗅球中神经元间的相互作用及同步运动分析

    Institute of Scientific and Technical Information of China (English)

    徐爱蕾; 杜莹; 王如彬

    2013-01-01

    Olfactory bulb plays an important part in signal encoding of an olfactory system. The interaction between excitatory mitral cells and inhibitory granule cells is particularly crucial. Here, the current situation of synchronous oscillation in the network of an olfactory system was firstly introduced. Then, the dynamic models of a mitral cell and a granular cell in the olfactory bulb were built. The simulation figures showed the firing patterns of a single mitral cell, a single granular cell, and these two kinds of cells having a coupling relationship. The results indicated that mitral cells have an excitatory effect on granular cells, and granular cells have an inhibitory effect on mitral cells; the firing pattern varies with different synaptic strength. In addition, simple olfactory network models were built, the influence of ring-like and grid-like neuronal network of granular cells on the synchronization of two mitral cells was analyzed. Different types of firing synchronization were diagnosed by means of ISI-distance method. The numerical analysis indicated that grid-like neuronal network of granular cells can make mitral cells synchronize better.%嗅球对嗅觉信息的处理是嗅觉系统信号编码的一个重要环节,其中兴奋性的僧帽细胞(Mitral Cell,MC)与抑制性的颗粒细胞(Granular Cell,GC)的相互作用尤为关键.本文首先介绍了嗅觉系统网络中关于同步振荡的研究现状,然后建立嗅球中僧帽细胞及颗粒细胞的动力学模型,仿真得到了单个僧帽细胞、颗粒细胞以及僧帽细胞与颗粒细胞在耦合条件下神经元的发放模式.结果表明,僧帽细胞对颗粒细胞有兴奋性作用,而颗粒细胞对僧帽细胞有抑制性作用,细胞放电序列随着突触连接强度的改变而改变.此外,建立简单的嗅觉网络模型,分析了当颗粒细胞分别构成环形和网格状两种拓扑结构时,不同网络对两个僧帽细胞同步性的影响,用同步性指标ISI

  4. Synchronization in multicell systems exhibiting dynamic plasticity

    Indian Academy of Sciences (India)

    C Suguna; Somdatta Sinha

    2008-08-01

    Collective behaviour in multicell systems arises from exchange of chemicals/signals between cells and may be different from their intrinsic behaviour. These chemicals are products of regulated networks of biochemical pathways that underlie cellular functions, and can exhibit a variety of dynamics arising from the non-linearity of the reaction processes. We have addressed the emergent synchronization properties of a ring of cells, diffusively coupled by the end product of an intracellular model biochemical pathway exhibiting non-robust birhythmic behaviour. The aim is to examine the role of intercellular interaction in stabilizing the non-robust dynamics in the emergent collective behaviour in the ring of cells. We show that, irrespective of the inherent frequencies of individual cells, depending on the coupling strength, the collective behaviour does synchronize to only one type of oscillations above a threshold number of cells. Using two perturbation analyses, we also show that this emergent synchronized dynamical state is fairly robust under external perturbations. Thus, the inherent plasticity in the oscillatory phenotypes in these model cells may get suppressed to exhibit collective dynamics of a single type in a multicell system, but environmental influences can sometimes expose this underlying plasticity in its collective dynamics.

  5. IPTV inter-destination synchronization: A network-based approach

    NARCIS (Netherlands)

    Stokking, H.M.; Deventer, M.O. van; Niamut, O.A.; Walraven, F.A.; Mekuria, R.N.

    2010-01-01

    This paper introduces a novel network-based approach to inter-destination media synchronization. The approach meets the need for synchronization in advanced TV concepts like social TV and offers high scalability, unlike conventional end-point based approaches. The solution for interdestination media

  6. A High-Performance Operational Amplifier for High-Speed High-Accuracy Switch-Capacitor Cells

    Institute of Scientific and Technical Information of China (English)

    Qi Fan; Ning Ning; Qi Yu; Da Chen

    2007-01-01

    A highspeed highaccuracy fully differenttial operational amplifier (opamp) is realized based on noMillercapacitor feedforward (NMCF) compensation scheme. In order to achieve a good phase margin, the NMCF compensation scheme uses the positive phase shift of lefthalfplane (LHP) zero caused by the feedforward path to counteract the negative phase shift of the nondominant pole. Compared to traditional Miller compensation method, the opamp obtains high gain and wide band synchronously without the polesplitting effect while saves significant chip area due to the absence of the Miller capacitor. Simulated by the 0.35 μm CMOS RF technology, the result shows that the openloop gain of the opamp is 118 dB with the unity gainbandwidth (UGBW)of 1 GHz, and the phase margin is 61°while the settling time is 5.8 ns when achieving 0.01% accuracy. The opamp is especially suitable for the frontend sample/hold (S/H)cell and the multiplying D/A converter(MDAC) module of the highspeed highresolution pipelined A/D converters(ADCs).

  7. Methodologies for high efficiency perovskite solar cells.

    Science.gov (United States)

    Park, Nam-Gyu

    2016-01-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  8. Methodologies for high efficiency perovskite solar cells

    Science.gov (United States)

    Park, Nam-Gyu

    2016-06-01

    Since the report on long-term durable solid-state perovskite solar cell in 2012, perovskite solar cells based on lead halide perovskites having organic cations such as methylammonium CH3NH3PbI3 or formamidinium HC(NH2)2PbI3 have received great attention because of superb photovoltaic performance with power conversion efficiency exceeding 22 %. In this review, emergence of perovskite solar cell is briefly introduced. Since understanding fundamentals of light absorbers is directly related to their photovoltaic performance, opto-electronic properties of organo lead halide perovskites are investigated in order to provide insight into design of higher efficiency perovskite solar cells. Since the conversion efficiency of perovskite solar cell is found to depend significantly on perovskite film quality, methodologies for fabricating high quality perovskite films are particularly emphasized, including various solution-processes and vacuum deposition method.

  9. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... (RDE) and (ii) a gas diffusion electrode (GDE) setup designed for experiments in conc. H3PO4. The pressurized cell is demonstrated by tests on polycrystalline platinum electrodes up to 150 ºC. Functionality of the RDE system is proved studying the oxygen reduction reaction (ORR) at temperatures up...... to 140 ºC and oxygen pressures up to ~100 bar at room temperature. The GDE cell is successfully tested at 130 ºC by means of direct oxidation of methanol and ethanol, respectively. In the second part of the thesis, the emphasis is put on the ORR in H3PO4 with particular focus on the mass transport...

  10. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  11. 基于GPS和高精度实时时钟的时间同步方法%Time Synchronization Based on GPS and High-Accuracy Real-Time Clock

    Institute of Scientific and Technical Information of China (English)

    王向军; 张亚元; 张龙祥

    2016-01-01

    Time synchronization plays a significant role in aerospace measurement and control, satellite remote-sensing, military range, vision measuring, electric power transmission and many other areas.Ai-ming at the problem of low resolution of computer timing system, this paper proposes a method of comput-er time synchronization.It utilizes the pulses per second and time messages from a GPS receiver as the high-resolution time source.The high-accuracy time module acquires time messages from time source and transforms them to the computer through RS232 serial port.Time delay can be computed by imitating the process of precision time protocol synchronization.The computer completes time synchronization by com-pensating time delay to the precision time.The method of integral second pulse comparison can be used to test the synchronization precision.Results show that precision can be better than 500 μs.%时间同步在航天测控、卫星遥感、军事靶场、视觉测量、电力运输等领域有重要意义.针对计算机时间系统分辨率低的问题,提出使用全球定位系统( GPS)接收机的整秒脉冲信号和串口时间信息,作为高精度的时间源,具有高频率稳定性的时间模块与该时间源同步;计算机通过RS232串口从时间模块获取时间信息,利用模拟精密时间协议时间同步方法的过程,测量串口通信过程中的延时并补偿,完成计算机高精度时间同步.通过整秒脉冲比对的方法测试时间同步的精度.实验表明,时间同步方法的同步精度优于500 μs.

  12. Synchronization trigger control system for flow visualization

    Science.gov (United States)

    Chun, K. S.

    1987-01-01

    The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

  13. Modulated Field Synchronous Generator for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Petru Chioncel

    2013-01-01

    Full Text Available This paper presents a modern electromechanical conversion systemsolution as the modulated field synchronous generator, offering on theone hand, an output voltage with constant frequency in terms of speedvariation of the wind turbine and on the other hand an advantagepower / weight ratio due to the high frequency for which the magneticcircuit of the electric machine is sized. The mathematical model of the modulated field synchronous generator is implemented in MatLABmodeling language, highlighting the command structure on thetransistors bases of the inverter transistors, through which thefunctioning of the electric machine can be studied, especially in terms of the frequency of the delivered voltage.

  14. Cycle slipping in phase synchronization systems

    Science.gov (United States)

    Yang, Ying; Huang, Lin

    2007-02-01

    Cycle slipping is a characteristically nonlinear phenomenon in phase synchronization systems, which is highly dependent of the initial state of the system. Slipping a cycle means that the phase error is increased to such an extent that the generator to be synchronized slips one complete cycle with respect to the input phase. In this Letter, a linear matrix inequality (LMI) based approach is proposed and the estimation of the number of cycles which slips a solution of the system is obtained by solving a quasi-convex optimization problem of LMI. Applications to phase locked loops demonstrate the validity of the proposed approach.

  15. Synchronous generator wind energy conversion control system

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, A.L.R. [Wind Energy Group, Recife (Brazil); Lima, A.M.N.; Jacobina, C.B.; Simoes, F.J. [DEE, Campina Grande (Brazil)

    1996-12-31

    This paper presents the performance evaluation and the design of the control system of a WECS (Wind Energy Conversion System) that employs a synchronous generator based on its digital simulation. The WECS discussed in this paper is connected to the utility grid through two Pulse Width Modulated (PWM) power converters. The structure of the proposed WECS enables us to achieve high performance energy conversion by: (i) maximizing the wind energy capture and (ii) minimizing the reactive power flowing between the grid and the synchronous generator. 8 refs., 19 figs.

  16. Synchronization criteria based on a general complex dynamical network model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-lin; WANG Chang-jian; XU Cong-fu

    2008-01-01

    Many complex dynamical networks display synchronization phenomena. We introduce a general complex dynamical network model. The model is equivalent to a simple vector model of adopting the Kronecker product. Some synchronization criteria, including time-variant networks and time-varying networks, are deduced based on Lyapunov's stability theory, and they are proven on the condition of obtaining a certain synchronous solution of an isolated cell. In particular, the inner-coupling matrix directly determines the synchronization of the time-invariant network; while for a time-varying periodic dynamical network, the asymptotic stability of a synchronous solution is determined by a constant matrix which is related to the fundamental solution matrices of the linearization system. Finally, illustrative examples are given to validate the results.

  17. Synchronous laparoscopic resection of colorectal and renal/adrenal neoplasms.

    Science.gov (United States)

    Ng, Simon S M; Lee, Janet F Y; Yiu, Raymond Y C; Li, Jimmy C M; Leung, Ka Lau

    2007-08-01

    Synchronous laparoscopic resections of coexisting abdominal diseases are shown to be feasible without additional postoperative morbidity. We report our experience with synchronous laparoscopic resection of colorectal carcinoma and renal/adrenal neoplasms with an emphasis on surgical and oncologic outcomes. Five patients diagnosed to have synchronous colorectal carcinoma and renal/adrenal neoplasms (renal cell carcinoma in 2 patients, adrenal cortical adenoma in 2 patients, and adrenal metastasis in 1 patient) underwent synchronous laparoscopic resection. The median operative time was 420 minutes and the median operative blood loss was 1000 mL. Three patients developed minor complications, including wound infection in 2 patients and retention of urine in 1 patient. There was no operative mortality. The median duration of hospital stay was 11 days. At a median follow-up of 17.6 months, no patient developed recurrence of disease. Synchronous laparoscopic resection of colorectal and renal/adrenal neoplasms is technically feasible and safe.

  18. Definitive Chemoradiation Therapy Following Surgical Resection or Radiosurgery Plus Whole-Brain Radiation Therapy in Non-Small Cell Lung Cancer Patients With Synchronous Solitary Brain Metastasis: A Curative Approach

    Energy Technology Data Exchange (ETDEWEB)

    Parlak, Cem, E-mail: cemparlak@gmail.com [Department of Radiation Oncology, Baskent University, Adana Medical Faculty, Adana (Turkey); Mertsoylu, Hüseyin [Department of Medical Oncology, Baskent University, Adana Medical Faculty, Adana (Turkey); Güler, Ozan Cem; Onal, Cem; Topkan, Erkan [Department of Radiation Oncology, Baskent University, Adana Medical Faculty, Adana (Turkey)

    2014-03-15

    Purpose/Objectives: The aim of this study was to evaluate the impact of definitive thoracic chemoradiation therapy following surgery or stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT) on the outcomes of patients with non-small cell lung cancer (NSCLC) with synchronous solitary brain metastasis (SSBM). Methods and Materials: A total of 63 NSCLC patients with SSBM were retrospectively evaluated. Patients were staged using positron emission tomography-computed tomography in addition to conventional staging tools. Thoracic radiation therapy (TRT) with a total dose of 66 Gy in 2 Gy fractions was delivered along with 2 cycles of cisplatin-based chemotherapy following either surgery plus 30 Gy of WBRT (n=33) or SRS plus 30 Gy of WBRT (n=30) for BM. Results: Overall, the treatment was well tolerated. All patients received planned TRT, and 57 patients (90.5%) were also able to receive 2 cycles of chemotherapy. At a median follow-up of 25.3 months (7.1-52.1 months), the median months of overall, locoregional progression-free, neurological progression-free, and progression-free survival were 28.6, 17.7, 26.4, and 14.6, respectively. Both univariate and multivariate analyses revealed that patients with a T1-T2 thoracic disease burden (P=.001), a nodal stage of N0-N1 (P=.003), and no weight loss (P=.008) exhibited superior survival. Conclusions: In the present series, surgical and radiosurgical treatments directed toward SSBM in NSCLC patients were equally effective. The similarities between the present survival outcomes and those reported in other studies for locally advanced NSCLC patients indicate the potentially curative role of definitive chemoradiation therapy for highly selected patients with SSBM.

  19. Synchronous transfer circuits for redundant systems

    Science.gov (United States)

    Nagano, S.

    1978-01-01

    Circuit arrangements for flip-flops, counters, and clock drivers in redundant systems ensure that control is synchronously transferred to surviving components when failure occurs. In addition to original application to spacecraft systems, redundant circuits have terrestrial uses in power generators, solar-energy converters, computers, vehicle controllers, and other systems demanding high reliability.

  20. The transient ladder synchronization of chaotic systems

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.-K. [Department of Industrial Engineering and Management, Hsiuping Institute of Technology, No. 11, Gungye Rd., Dali City, Taichung, Taiwan (China)]. E-mail: kanechen@giga.net.tw; Sheu, L.-J. [Department of Mechanical Engineering, Chung Hua University, Hsinchu, Taiwan (China)]. E-mail: ljsheu@chu.edu.tw

    2006-07-03

    A new type for chaotically synchronizing systems, transient ladder chaos synchronization, is proposed in this Letter. For some physical systems, chaotic synchronization is possible in only some of the variables. It is shown that, for the non-synchronizing variable, synchronization up to a constant difference for t{sub 1}=synchronization and anti-synchronization are illustrated by using two identical chaotic Froude pendulums. Numerical simulations are shown for demonstration.

  1. Fictitious Reference Iterative Tuning-Based Two-Degrees-of-Freedom Method for Permanent Magnet Synchronous Motor Speed Control Using FPGA for a High-Frequency SiC MOSFET InverterMOSFET Inverter

    Directory of Open Access Journals (Sweden)

    Charles Ronald Harahap

    2016-11-01

    Full Text Available This paper proposes proportional-integral/proportional gain controller parameter tuning in a two-degrees-of-freedom (2DOF control system using the fictitious reference iterative tuning (FRIT method for permanent magnet synchronous motor (PMSM speed control using a field-programmable gate array (FPGA for a high-frequency SiC MOSFET (metal oxide semiconductor field-effect transistor inverter. The PI-P (proportional-integral/proportional controller parameters can be tuned using the FRIT method from one-shot experimental data without using a mathematical model of the plant. Particle swarm optimization is used for FRIT optimization. An inverter that uses a SiC MOSFET is presented to achieve high-frequency operation at up to100 kHz using a switching pulse-width modulation (PWM technique. As a result, a high-responsivity and high-stability PMSM (permanent magnet synchronous motor control system is achieved, where the speed response follows the ideal response characteristic for both the step response and the disturbance response. High-responsivity and optimal disturbance rejection can be achieved using the 2DOF control system. FPGA-based digital hardware control is used to maximize the switching frequency of the SiC MOSFET inverter. Finally, an experimental system is set up, and experimental results are presented to prove the viability of the proposed method.

  2. Research on Synchronous Control Method of Honeycomb Paper Core in High Speed Paper Feed and Linear Cutting%蜂窝纸芯高速送纸和直线剪纸的同步控制方法研究

    Institute of Scientific and Technical Information of China (English)

    杜建铭; 刘庆国; 罗世洲; 钟仲洪

    2013-01-01

    在新型蜂窝纸芯水平高速剪切生产线研发中,剪切速度成为制约生产效率的关键问题,采用直线电机取代普通变频调速电机-曲柄滑块机构,驱动1600 mm长的动刀,在25 mm的行程上,做600~800刀/min的往复直线剪切运动;采用高响应步进电机或力矩电机驱动凸轮间歇送纸机构取代原有自由落体式送纸,以满足高速剪纸的需要,此时剪纸与送纸的同步控制成为控制的难点之一。研究了高速间歇送纸的触发条件,同时对剪纸与送纸同步过程中的时序进行了计算和分析,提出了一种同步控制方法。实验结果表明,该方法能有效实现高速剪切下间歇送纸的同步控制。%In the R&D of new honeycomb paper core horizontal high-speed shear production line,cutting speed has become key problem which restricted production efficiency. By replacing the general frequency variable motor slider-crank mechanism with linear stepping motor to drive the cutter with 1 600 mm in length,reciprocating linear exercise of 600~800 times of cutting per minute in the distance of 25 mm was done. The freely falling paper transmission mechanism was replaced by the cam intermittent paper feed driven with high response stepping motor or torque motor,so as to meet needs in high-speed cutting of paper,here the synchronous control be-tween the paper cutting and the paper transmission became one of the difficulties in control. The trigger conditions of high-speed inter-mittent paper transmission were researched,at the same time,the timing of the synchronization process of paper cutting and paper transmission was calculated and analyzed,and a way of synchronous control was presented. The experimental results show that this method can effectively achieve the synchronous control of the intermittent feed of the high shear.

  3. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... of dissolved oxygen. A potential step method (hydrodynamic chronocoulometry) is evaluated for simultaneous measurement of diffusivity and solubility of oxygen by means of RDE. Finally, the ORR tests are extended to conc. H3PO4 at more relevant working temperatures and under increased oxygen pressure. Direct...... of platinumphosphoric acid. At room temperature, a relative slow ORR hindering process is active, which requires using a fast method (cyclic voltammetry with high scan rate / hydrodynamic chronocoulometry) to accurately measure the diffusion limited currents, and thus, oxygen diffusivity and solubility. In conc. H3PO4...

  4. [Conception rate and embryo development in guinea pigs with synchronized estrus induced by progesterone implant].

    Science.gov (United States)

    Ueda, H; Kosaka, T; Takahashi, K W

    1994-01-01

    Observations were made on the timing of mating and the pre-implantation development of fertilized eggs in guinea pigs synchronized by long-term progesterone treatment. Females received a subcutaneous implant of progesterone-filled silastic tubing for 14 days. Copulation was observed from the evening of day 4 to the morning of day 6 in 53 of 54 females (98%). Most of them (47/53, 89%) copulated on day 5 after removal of the tubing. Designating the day of copulation (day 5 after removal of the tubing) as day 0 of gestation, embryos collected from the genital tract were at the 4-cell, 8-cell, morula, and blastocyst stages on days 1, 3, 4 and 5 of gestation, respectively. Eggs were recovered at high incidence (85-100%) from days 1 to 5 of gestation. On day 6 gestation, no eggs were recovered from the genital tract, suggesting that implantation had occurred. The mean litter size (+/- S. D.) was 4.0 +/- 0.8 pups, which were born normally after a mean gestation period of 67 +/- 1 days in 7 synchronized females. Since the female guinea pigs synchronized by the long-term progesterone treatment had normal reproductive ability similar to that of cyclic females, this technique would make it possible to obtain animals at a scheduled time even in smaller-sized colonies. In addition, observations on the pre-implantation development of embryos in females with synchronized estrus might be a useful aid in the field of reproductive research.

  5. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  6. Systematic Characterization of Cell Cycle Phase-dependent Protein Dynamics and Pathway Activities by High-content Microscopy-assisted Cell Cycle Phenotyping

    Institute of Scientific and Technical Information of China (English)

    Christopher Bruhn; Torsten Kroll; Zhao-Qi Wang

    2014-01-01

    Cell cycle progression is coordinated with metabolism, signaling and other complex cel-lular functions. The investigation of cellular processes in a cell cycle stage-dependent manner is often the subject of modern molecular and cell biological research. Cell cycle synchronization and immunostaining of cell cycle markers facilitate such analysis, but are limited in use due to unphysiological experimental stress, cell type dependence and often low flexibility. Here, we describe high-content microscopy-assisted cell cycle phenotyping (hiMAC), which integrates high-resolution cell cycle profiling of asynchronous cell populations with immunofluorescence microscopy. hiMAC is compatible with cell types from any species and allows for statistically pow-erful, unbiased, simultaneous analysis of protein interactions, modifications and subcellular locali-zation at all cell cycle stages within a single sample. For illustration, we provide a hiMAC analysis pipeline tailored to study DNA damage response and genomic instability using a 3–4-day protocol, which can be adjusted to any other cell cycle stage-dependent analysis.

  7. Synchronized Expansion Design of Small Diameter Triple Eccentric Butterfly Valve under High Temperature%高温工况下小口径三偏心蝶阀膨胀补偿设计

    Institute of Scientific and Technical Information of China (English)

    谢军

    2012-01-01

    By analyzing the fact that small diameter of triple eccentric butterfly valve effected by hot deformation on seal performance in high temperature working condition, the valve seat synchronous heat expansion compensation design was put forward. The valve having adopted such structure obtained good sealing performance in practical application.%分析了高温工况下小口径三偏心蝶阀产生热变形对密封性能的影响,提出了阀座圈同步膨胀补偿设计方案,在实际应用中效果较好.

  8. Remote Synchronization in Complex Networks

    CERN Document Server

    Gambuzza, Lucia Valentina; Fiasconaro, Alessandro; Fortuna, Luigi; Gómez-Gardeñes, Jesús; Frasca, Mattia

    2013-01-01

    We show the existence of a novel dynamical state called remote synchronization in general networks of coupled oscillators. This state is characterized by the synchronization of pairs of nodes that are not directly connected via a physical link or any sequence of synchronized nodes. This phenomenon cannot be observed in networks of phase oscillators as its underlying mechanism is the modulation of the amplitude of those intermediary nodes between the remotely synchronized units. Our findings thus show the ubiquity and robustness of these states and bridge the gap from their recent observation in simple toy graphs to complex networks.

  9. PARTIAL SYNCHRONIZATION BETWEEN DIFFERENT SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun; LIU Zeng-rong

    2005-01-01

    A new method for partial synchronization between different systems was obtained. The definition of partial synchronization under which the problem works is given. The stability of the method is analyzed by the Liapunov function method and the condition of choosing the control term is derived. The reliability of this method is proved by some numerical examples, in which the dynamical behaviors of the synchronized systems are observed and it is found that whatever state the response system is partial synchronization can be always achieved by adding some proper control term.

  10. High temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters...... of the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept...... of and motivated extensive research activity in the field. The last 11 chapters summarize the state-of-the-art of technological development of high temperature-PEMFCs based on acid doped PBI membranes including catalysts, electrodes, MEAs, bipolar plates, modelling, stacking, diagnostics and applications....

  11. High performance internal reforming unit for high temperature fuel cells

    Science.gov (United States)

    Ma, Zhiwen; Venkataraman, Ramakrishnan; Novacco, Lawrence J.

    2008-10-07

    A fuel reformer having an enclosure with first and second opposing surfaces, a sidewall connecting the first and second opposing surfaces and an inlet port and an outlet port in the sidewall. A plate assembly supporting a catalyst and baffles are also disposed in the enclosure. A main baffle extends into the enclosure from a point of the sidewall between the inlet and outlet ports. The main baffle cooperates with the enclosure and the plate assembly to establish a path for the flow of fuel gas through the reformer from the inlet port to the outlet port. At least a first directing baffle extends in the enclosure from one of the sidewall and the main baffle and cooperates with the plate assembly and the enclosure to alter the gas flow path. Desired graded catalyst loading pattern has been defined for optimized thermal management for the internal reforming high temperature fuel cells so as to achieve high cell performance.

  12. Low-loss optical packet synchronization architecture

    Science.gov (United States)

    Franzen, Andre; Hunter, David K.; Andonovic, Ivan

    1998-10-01

    A novel synchronization architecture is presented for packet based optical networks, exhibiting low insertion loss and reduced crosstalk, taking advantage of the characteristics of AWG (arrayed waveguide grating) filters. Thus far, only logarithmic delay lines have been investigated rigorously, the generic structures either based on 2 X 2 switches or on a 1-to-m splitter combined with semiconductor optical amplifier gates. The first scheme introduces not only high loss but also crosstalk, producing a high amount of interferometric noise. The latter has a lot of splitting loss to accommodate but overall, fewer stages are necessary to achieve the same delay as more than two paths per stage can be set up. In this paper, AWGs in combination with wavelength converters replace the splitter/SOA-gate geometry minimizing the optical loss, ensuring that higher levels of optical power remain to traverse the adjacent switching matrix. This novel set-up ensures that only low levels of amplification are needed minimizing concomitant noise accumulation. An incoming cell or data stream will be converted to a distinct wavelength determined by an evaluation circuit in the electronic domain. The chosen wavelength maps the input to a length of fiber which in turn represents the necessary delay, effectively executing path length (and hence time alignment) equalization of different incoming packets. Once the wavelength conversion is executed the cell is fed into an AWG, governed by a `hardwired' translation-table (input/output), ensuring cells propagate to the correct output. Finer delays are realized by cascading the principle stage.

  13. Role of Network Topology in the Synchronization of Power Systems

    CERN Document Server

    Lozano, Sergi; Díaz-Guilera, Albert; 10.1140/epjb/e2012-30209-9

    2012-01-01

    We study synchronization dynamics in networks of coupled oscillators with bimodal distribution of natural frequencies. This setup can be interpreted as a simple model of frequency synchronization dynamics among generators and loads working in a power network. We derive the minimum coupling strength required to ensure global frequency synchronization. This threshold value can be efficiently found by solving a binary optimization problem, even for large networks. In order to validate our procedure, we compare its results with numerical simulations on a realistic network describing the European interconnected high-voltage electricity system, finding a very good agreement. Our synchronization threshold can be used to test the stability of frequency synchronization to link removals. As the threshold value changes only in very few cases when aplied to the European realistic network, we conclude that network is resilient in this regard. Since the threshold calculation depends on the local connectivity, it can also b...

  14. Stroboscope Based Synchronization of Full Frame CCD Sensors

    Directory of Open Access Journals (Sweden)

    Liang Shen

    2017-04-01

    Full Text Available The key obstacle to the use of consumer cameras in computer vision and computer graphics applications is the lack of synchronization hardware. We present a stroboscope based synchronization approach for the charge-coupled device (CCD consumer cameras. The synchronization is realized by first aligning the frames from different video sequences based on the smear dots of the stroboscope, and then matching the sequences using a hidden Markov model. Compared with current synchronized capture equipment, the proposed approach greatly reduces the cost by using inexpensive CCD cameras and one stroboscope. The results show that our method could reach a high accuracy much better than the frame-level synchronization of traditional software methods.

  15. Method and system to synchronize acoustic therapy with ultrasound imaging

    Science.gov (United States)

    Owen, Neil (Inventor); Bailey, Michael R. (Inventor); Hossack, James (Inventor)

    2009-01-01

    Interference in ultrasound imaging when used in connection with high intensity focused ultrasound (HIFU) is avoided by employing a synchronization signal to control the HIFU signal. Unless the timing of the HIFU transducer is controlled, its output will substantially overwhelm the signal produced by ultrasound imaging system and obscure the image it produces. The synchronization signal employed to control the HIFU transducer is obtained without requiring modification of the ultrasound imaging system. Signals corresponding to scattered ultrasound imaging waves are collected using either the HIFU transducer or a dedicated receiver. A synchronization processor manipulates the scattered ultrasound imaging signals to achieve the synchronization signal, which is then used to control the HIFU bursts so as to substantially reduce or eliminate HIFU interference in the ultrasound image. The synchronization processor can alternatively be implemented using a computing device or an application-specific circuit.

  16. FPGA based fast synchronous serial multi-wire links synchronization

    Science.gov (United States)

    Pozniak, Krzysztof T.

    2013-10-01

    The paper debates synchronization method of multi-wire, serial link of constant latency, by means of pseudo-random numbers generators. The solution was designed for various families of FPGA circuits. There were debated synchronization algorithm and functional structure of parameterized transmitter and receiver modules. The modules were realized in VHDL language in a behavioral form.

  17. The emergence of synchronization behavior in Physarum polycephalum and its particle approximation.

    Science.gov (United States)

    Tsuda, Soichiro; Jones, Jeff

    2011-03-01

    The regeneration process of contractile oscillation in the plasmodium of Physarum polycephalum is investigated experimentally and modelled computationally. When placed in a well, the Physarum cell restructures the body (fusion of small granule-like cells) and shows various complex oscillation patterns. After it completed the restructuring and regained synchronized oscillation within the body, the cell shows bilateral oscillation or rotating wave pattern. This regeneration process did not depend on the well size and all the cases tested here showed similar time course. Phase synchronization analysis based on Hilbert Transform also suggested that the cell can develop a fully synchronized oscillation within a fixed time no matter what the cell size is. A particle-based computational model was developed in order to model the emergence of oscillation patterns. Particles employing very simple and identical sensory and motor behaviors interacted with each other via the sensing and deposition of chemoattractants in a diffusive environment. From a random and almost homogeneous distribution, emergent domains of oscillatory activity emerged. By increasing the sensory radius the model simulated the regeneration process of the real plasmodium. In addition, the model replicated the rotating wave and bilateral oscillation pattern when the sensory radius was increased. The results suggest that complex emergent oscillatory behaviors (and thus the high-level systems which may utilize them, such as pumping and transport mechanisms) may be developed from simple materials inspired by Physarum slime mold. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  18. Variance based OFDM frame synchronization

    Directory of Open Access Journals (Sweden)

    Z. Fedra

    2012-04-01

    Full Text Available The paper deals with a new frame synchronization scheme for OFDM systems and calculates the complexity of this scheme. The scheme is based on the computing of the detection window variance. The variance is computed in two delayed times, so a modified Early-Late loop is used for the frame position detection. The proposed algorithm deals with different variants of OFDM parameters including guard interval, cyclic prefix, and has good properties regarding the choice of the algorithm's parameters since the parameters may be chosen within a wide range without having a high influence on system performance. The verification of the proposed algorithm functionality has been performed on a development environment using universal software radio peripheral (USRP hardware.

  19. An update on estrus synchronization in goats: a minor species.

    Science.gov (United States)

    Whitley, N C; Jackson, D J

    2004-01-01

    Estrus synchronization allows for parturition at suitable times to take advantage of niche markets, feed supplies, labor, and rising price trends. In the past, synchronization of estrus in goats has focused primarily on dairy goats to allow for optimal timing of milk production. However, recent interest in meat goat production has resulted in attempts to use dairy goat, sheep, and cattle synchronization regimens in meat goat management systems. Methods of synchronization have included techniques as simple as alteration of light patterns or manipulation of social inputs (i.e., the buck effect) and as complex as varying timed hormonal treatments combined with light alteration and the buck effect. The synchronization of estrus using timed hormonal treatments seems to be more convenient in many meat goat production situations. Examples of hormones used include melatonin, progestogens (administered orally, as an injection, or by using intravaginal releasing devices), gonadotropins/GnRH (or agonists), and PG alone or in combination. As is seen with sheep and cattle, breed and/or breed type, stage of production, and environmental effects can influence synchronization success in goats. The introduction of breeds developed in other countries for rapid growth, such as the Boer goat, and increased consumer and producer interest have added to the impetus for developing cost-efficient and highly effective estrus synchronization regimens. New research is being conducted and various synchronization methods are being attempted in goats, a minor species, and the objective of this paper is to review these efforts.

  20. HIGH SPEED KERR CELL FRAMING CAMERA

    Science.gov (United States)

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  1. Synchronization of an uncertain chaotic system via recurrent neural networks

    Institute of Scientific and Technical Information of China (English)

    谭文; 王耀南

    2005-01-01

    Incorporating distributed recurrent networks with high-order connections between neurons, the identification and synchronization problem of an unknown chaotic system in the presence of unmodelled dynamics is investigated. Based on the Lyapunov stability theory, the weights learning algorithm for the recurrent high-order neural network model is presented. Also, analytical results concerning the stability properties of the scheme are obtained. Then adaptive control law for eliminating synchronization error of uncertain chaotic plant is developed via Lyapunov methodology.The proposed scheme is applied to model and synchronize an unknown Rossler system.

  2. Global Exponential Projective Synchronization and Lag Synchronization of Hyperchaotic Lü System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qun-Jiao; LU Jun-An; JIA Zhen

    2009-01-01

    This paper investigates the projective synchronization and lag synchronization of a new hyperchaotic system[Physica A 364 (2006) 103]. On the basis of Lyapunov stability theory, two novel nonlinear controllers are respectively designed to guarantee the global exponential projective synchronization (including complete synchronization and anti-synchronization) and lag synchronization. Finally, numerical simulations are given to show the effectiveness of the main results.

  3. Emergence of dynamical order synchronization phenomena in complex systems

    CERN Document Server

    Manrubia, Susanna C; Zanette, Damián H

    2004-01-01

    Synchronization processes bring about dynamical order and lead tospontaneous development of structural organization in complex systemsof various origins, from chemical oscillators and biological cells tohuman societies and the brain. This book provides a review and adetailed theoretical analysis of synchronization phenomena in complexsystems with different architectures, composed of elements withperiodic or chaotic individual dynamics. Special attention is paid tostatistical concepts, such as nonequilibrium phase transitions, orderparameters and dynamical glasses.

  4. Development of the Synchronous Transmission System of High Speed Relief Curved Lid Printer%高速凸版曲面印盖机同步传动系统的开发

    Institute of Scientific and Technical Information of China (English)

    王贤洵; 王贤淮; 王昌佑; 许中明

    2013-01-01

    A multi-station synchronous transmission system of high speed relief curved lid printer, which is capable of synchronizing printing with UV ink and printing and caring with light ink, was developed by researching the key technology for the equipment's transmission system. The system consists of two major components, namely, step dividing plate of multi-station and step dividing device of multi-station synchronous transmission. The system successfully simplifies the printing process executed by similar printing machinery in China, which usually involves primary printing with UV ink followed by secondary printing with light oil and caring with specialized machinery. By streamlining the production process and reducing the operators needed, this technology improves automation and efficiency of printing equipment.%  对高速圆柱形凸版曲面印盖机传动系统关键技术进行研究,开发出一种具有UV油墨及光油二次印刷、二次固化的多工位同步传动系统,该系统由多工位步进分度转盘和多工位同步传动步进分度器两大部件组成。该系统的应用,改变了国内同类设备UV彩印后再配套上光机、固化机进行再次印刷及固化的繁琐工艺,在提高设备自动化程度和效率的同时,缩短了生产流程,也减少了所需操作人员的数量。

  5. Digital synchronization and communication techniques

    Science.gov (United States)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  6. Order release in synchronous manufacturing

    NARCIS (Netherlands)

    Riezebos, J.

    2010-01-01

    Synchronous manufacturing aims at achieving the benefits of intermittent production lines in production situations that operate without lines. Benefits such as short and constant throughput times and predictable capacity loading can be acquired through an appropriate design of the synchronous manufa

  7. Biologically Inspired Intercellular Slot Synchronization

    Directory of Open Access Journals (Sweden)

    Alexander Tyrrell

    2009-01-01

    Full Text Available The present article develops a decentralized interbase station slot synchronization algorithm suitable for cellular mobile communication systems. The proposed cellular firefly synchronization (CelFSync algorithm is derived from the theory of pulse-coupled oscillators, common to describe synchronization phenomena in biological systems, such as the spontaneous synchronization of fireflies. In order to maintain synchronization among base stations (BSs, even when there is no direct link between adjacent BSs, some selected user terminals (UTs participate in the network synchronization process. Synchronization emerges by exchanging two distinct synchronization words, one transmitted by BSs and the other by active UTs, without any a priori assumption on the initial timing misalignments of BSs and UTs. In large-scale networks with inter-BS site distances up to a few kilometers, propagation delays severely affect the attainable timing accuracy of CelFSync. We show that by an appropriate combination of CelFSync with the timing advance procedure, which aligns uplink transmission of UTs to arrive simultaneously at the BS, a timing accuracy within a fraction of the inter-BS propagation delay is retained.

  8. Exploiting Schemas in Data Synchronization

    DEFF Research Database (Denmark)

    Foster, J. Nathan; Greenwald, Michael B.; Kirkegaard, Christian

    2005-01-01

    Increased reliance on optimistic data replication has led to burgeoning interest in tools and frameworks for disconnected updates to replicated data.We have implemented a generic synchronization framework, called HARMONY, that can be used to build state-based synchronizers for a wide variety of t...

  9. Benefits of Synchronous Online Courses

    Science.gov (United States)

    Moser, Scott; Smith, Phil

    2015-01-01

    Most online courses are offered as "asynchronous" courses and have no real-time contact with students. The Synchronous online alternative provides normal scheduled class time and allows students to login to a virtual online classroom with the instructor. We provide an overview of two different platforms for hosting synchronous classes…

  10. Network algebra for synchronous dataflow

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.; Ștefánescu, G.

    2013-01-01

    We develop an algebraic theory of synchronous dataflow networks. First, a basic algebraic theory of networks, called BNA (Basic Network Algebra), is introduced. This theory captures the basic algebraic properties of networks. For synchronous dataflow networks, it is subsequently extended with

  11. Order release in synchronous manufacturing

    NARCIS (Netherlands)

    Riezebos, J.

    2010-01-01

    Synchronous manufacturing aims at achieving the benefits of intermittent production lines in production situations that operate without lines. Benefits such as short and constant throughput times and predictable capacity loading can be acquired through an appropriate design of the synchronous manufa

  12. Synchronization dynamics of two different dynamical systems

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Albert C.J., E-mail: aluo@siue.edu [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States); Min Fuhong [Department of Mechanical and Industrial Engineering, Southern Illinois University Edwardsville, Edwardsville, IL 62026-1805 (United States)

    2011-06-15

    Highlights: > Synchronization dynamics of two distinct dynamical systems. > Synchronization, de-synchronization and instantaneous synchronization. > A controlled pendulum synchronizing with the Duffing oscillator. > Synchronization invariant set. > Synchronization parameter map. - Abstract: In this paper, synchronization dynamics of two different dynamical systems is investigated through the theory of discontinuous dynamical systems. The necessary and sufficient conditions for the synchronization, de-synchronization and instantaneous synchronization (penetration or grazing) are presented. Using such a synchronization theory, the synchronization of a controlled pendulum with the Duffing oscillator is systematically discussed as a sampled problem, and the corresponding analytical conditions for the synchronization are presented. The synchronization parameter study is carried out for a better understanding of synchronization characteristics of the controlled pendulum and the Duffing oscillator. Finally, the partial and full synchronizations of the controlled pendulum with periodic and chaotic motions are presented to illustrate the analytical conditions. The synchronization of the Duffing oscillator and pendulum are investigated in order to show the usefulness and efficiency of the methodology in this paper. The synchronization invariant domain is obtained. The technique presented in this paper should have a wide spectrum of applications in engineering. For example, this technique can be applied to the maneuvering target tracking, and the others.

  13. High Aspect Ratio Semiconductor Heterojunction Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Redwing, Joan [Pennsylvania State Univ., University Park, PA (United States). Dept. of Material Science and Engineering; Mallouk, Tom [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemistry; Mayer, Theresa [Pennsylvania State Univ., University Park, PA (United States). Dept. of Electrical Engineering; Dickey, Elizabeth [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering; Wronski, Chris [Pennsylvania State Univ., University Park, PA (United States). Dept. of Electrical Engineering

    2013-05-17

    The project focused on the development of high aspect ratio silicon heterojunction (HARSH) solar cells. The solar cells developed in this study consisted of high density vertical arrays of radial junction silicon microwires/pillars formed on Si substrates. Prior studies have demonstrated that vertical Si wire/pillar arrays enable reduced reflectivity and improved light trapping characteristics compared to planar solar cells. In addition, the radial junction structure offers the possibility of increased carrier collection in solar cells fabricated using material with short carrier diffusion lengths. However, the high junction and surface area of radial junction Si wire/pillar array devices can be problematic and lead to increased diode leakage and enhanced surface recombination. This study investigated the use of amorphous hydrogenated Si in the form of a heterojunction-intrinsic-thin layer (HIT) structure as a junction formation method for these devices. The HIT layer structure has widely been employed to reduce surface recombination in planar crystalline Si solar cells. Consequently, it was anticipated that it would also provide significant benefits to the performance of radial junction Si wire/pillar array devices. The overall goals of the project were to demonstrate a HARSH cell with a HIT-type structure in the radial junction Si wire/pillar array configuration and to develop potentially low cost pathways to fabricate these devices. Our studies demonstrated that the HIT structure lead to significant improvements in the open circuit voltage (Voc>0.5) of radial junction Si pillar array devices compared to devices fabricated using junctions formed by thermal diffusion or low pressure chemical vapor deposition (LPCVD). In addition, our work experimentally demonstrated that the radial junction structure lead to improvements in efficiency compared to comparable planar devices for devices fabricated using heavily doped Si that had reduced carrier diffusion

  14. Noise and determinism in synchronized sheep dynamics

    Science.gov (United States)

    Grenfell, B. T.; Wilson, K.; Finkenstädt, B. F.; Coulson, T. N.; Murray, S.; Albon, S. D.; Pemberton, J. M.; Clutton-Brock, T. H.; Crawley, M. J.

    1998-08-01

    A major debate in ecology concerns the relative importance of intrinsic factors and extrinsic environmental variations in determining population size fluctuations. Spatial correlation of fluctuations in different populations caused by synchronous environmental shocks,, is a powerful tool for quantifying the impact of environmental variations on population dynamics,. However, interpretation of synchrony is often complicated by migration between populations,. Here we address this issue by using time series from sheep populations on two islands in the St Kilda archipelago. Fluctuations in the sizes of the two populations are remarkably synchronized over a 40-year period. A nonlinear time-series model shows that a high and frequent degree of environmental correlation is required to achieve this level of synchrony. The model indicates that if there were less environmental correlation, population dynamics would be much less synchronous than is observed. This is because of a threshold effect that is dependent on population size; the threshold magnifies random differences between populations. A refined model showsthat part of the required environmental synchronicity can be accounted for by large-scale weather variations. These results underline the importance of understanding the interaction between intrinsic and extrinsic influences on population dynamics.

  15. Chua's Circuit: Control and Synchronization

    Science.gov (United States)

    Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe

    Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.

  16. Synchronous anorectal melanoma

    Institute of Scientific and Technical Information of China (English)

    Drinko Balicevic; Karla Tomic; Miroslav Bekavac-Beslin; Igor Kovacevic; August Mijic; Mladen Belicza; Bozo Kruslin

    2006-01-01

    Anorectal melanoma is a very rare tumor with poor prognosis. Rectal bleeding is the most frequent symptom and surgical treatment ranges from local excision to radical abdominoperineal resection. We report a case of a 75-years-old male patient who presented with a history of recurrent rectal bleeding, and whose histopathological diagnosis was melanoma. Macroscopically, we found two distinct tumors in anorectal region, 0.5 cm and 1.5 cm from dentate line. The first one was pedunculated, on a thin stalk, measuring 1 cm in greatest diameter, and the second one was sessile and nodular measuring up to 2.8 cm in largest diameter. Microscopic examination and immunohistochemical analysis of both tumors confirmed the diagnosis of melanoma. This case represents multiple synchronous primary melanoma of the anorectal region, with a possibility that one of the lesions is primary melanoma and the second one is a satellite lesion.

  17. The Synchronic Fallacy

    DEFF Research Database (Denmark)

    Hansen, Erik W.

    , to exist, in order to underline the cognitive basis of man's (comprehension of) existence. A theory of history (existence) is set up on the basis of the traditional dualistic sign function, and the traditional sound-law concept and sound development are reinterpreted in terms of the theory's system...... of definitions. Historical linguistics ('change') is not dependent on an arbitrary synchronic theory. The two language universals polysemy and synonymy are reinterpreted and defined in accordance with the advanced definitions. Louis Hjelmslev's glossematic theory is the general horizon of the argument...... and is criticized for being based on a dated metaphysics. Two epistemological principles are introduced, The Phenomenal Error and The Critico-Philological Method. Conclusion: Historical linguistics is an autonomous scientific discipline.  ...

  18. Synchronization properties of heterogeneous neuronal networks with mixed excitability type.

    Science.gov (United States)

    Leone, Michael J; Schurter, Brandon N; Letson, Benjamin; Booth, Victoria; Zochowski, Michal; Fink, Christian G

    2015-03-01

    We study the synchronization of neuronal networks with dynamical heterogeneity, showing that network structures with the same propensity for synchronization (as quantified by master stability function analysis) may develop dramatically different synchronization properties when heterogeneity is introduced with respect to neuronal excitability type. Specifically, we investigate networks composed of neurons with different types of phase response curves (PRCs), which characterize how oscillating neurons respond to excitatory perturbations. Neurons exhibiting type 1 PRC respond exclusively with phase advances, while neurons exhibiting type 2 PRC respond with either phase delays or phase advances, depending on when the perturbation occurs. We find that Watts-Strogatz small world networks transition to synchronization gradually as the proportion of type 2 neurons increases, whereas scale-free networks may transition gradually or rapidly, depending upon local correlations between node degree and excitability type. Random placement of type 2 neurons results in gradual transition to synchronization, whereas placement of type 2 neurons as hubs leads to a much more rapid transition, showing that type 2 hub cells easily "hijack" neuronal networks to synchronization. These results underscore the fact that the degree of synchronization observed in neuronal networks is determined by a complex interplay between network structure and the dynamical properties of individual neurons, indicating that efforts to recover structural connectivity from dynamical correlations must in general take both factors into account.

  19. Dual-scale multimedia dynamic synchronization model

    Institute of Scientific and Technical Information of China (English)

    李乃祥

    2009-01-01

    Multimedia synchronization is the key technology in application of distributed multimedia.Solution of synchronization conflicts insides and among streams as well as that of user interaction,synchronization granularity refinement and synchronization precision improvement remain great challenges although great efforts have been invested by the academic circle.The construction method of a dual-scale dynamic synchronous model of multimedia presented in this article realizes multimedia synchronization on two sca...

  20. Synchronous imaging of coherent plasma fluctuations

    Science.gov (United States)

    Haskey, S. R.; Thapar, N.; Blackwell, B. D.; Howard, J.

    2014-03-01

    A new method for imaging high frequency plasma fluctuations is described. A phase locked loop and field programmable gate array are used to generate gating triggers for an intensified CCD camera. A reference signal from another diagnostic such as a magnetic probe ensures that the triggers are synchronous with the fluctuation being imaged. The synchronous imaging technique allows effective frame rates exceeding millions per second, good signal to noise through the accumulation of multiple exposures per frame, and produces high resolution images without generating excessive quantities of data. The technique can be used to image modes in the MHz range opening up the possibility of spectrally filtered high resolution imaging of MHD instabilities that produce sufficient light fluctuations. Some examples of projection images of plasma fluctuations on the H-1NF heliac obtained using this approach are presented here.

  1. High Energy Density aluminum/oxygen cell

    Science.gov (United States)

    Rudd, E. J.; Gibbons, D. W.

    An alternative to a secondary battery as the power source for vehicle propulsion is a fuel cell, an example of which is the metal/air cell using metals such as aluminum, zinc, or iron. Aluminum is a particularly attractive candidate, with high energy and power densities, environmentally acceptable and having a large, established industrial base for production and distribution. An aluminum/oxygen system is currently under development for a prototype unmanned, undersea vehicle (UUV) for the US navy and recent work has focussed upon low corrosion aluminum alloys, and an electrolyte management system for processing the by-products of the energy-producing reactions. This paper summarizes the progress made in both areas. Anode materials capable of providing high utilization factors over current densities ranging from 5 to 150 mA/cm 2 have been identified, such materials being essential to realize mission life for the UUV. With respect to the electrolyte management system, a filter/precipitator unit has been successfully operated for over 250 h in a large scale, half-cell system.

  2. Efficient synchronization of structurally adaptive coupled Hindmarsh-Rose neurons

    Energy Technology Data Exchange (ETDEWEB)

    Moujahid, A., E-mail: jibmomoa@gmail.com [Department of Physics of Materials, University of the Basque Country, 20018 San Sebastian (Spain); D' Anjou, A.; Torrealdea, F.J. [Department of Physics of Materials, University of the Basque Country, 20018 San Sebastian (Spain); Torrealdea, F. [UCL Institute of Neurology, Queen Square, London WC1N 3BG (United Kingdom)

    2011-11-15

    Highlights: > Neural activity might be constrained by a requirement of energy efficiency. > Signaling in synchrony is a normal way to propagate information between neurons. > Quality of synchrony affects the capacity to exchange information and the energy cost. > Adaptive mechanism leads to high degree of synchronization between nonidentical neurons. - Abstract: The use of spikes to carry information between brain areas implies complete or partial synchronization of the neurons involved. The degree of synchronization reached by two coupled systems and the energy cost of maintaining their synchronized behavior is highly dependent on the nature of the systems. For non-identical systems the maintenance of a synchronized regime is energetically a costly process. In this work, we study conditions under which two non-identical electrically coupled neurons can reach an efficient regime of synchronization at low energy cost. We show that the energy consumption required to keep the synchronized regime can be spontaneously reduced if the receiving neuron has adaptive mechanisms able to bring its biological parameters closer in value to the corresponding ones in the sending neuron.

  3. Generalized reduced-order synchronization of chaotic system based on fast slide mode

    Institute of Scientific and Technical Information of China (English)

    Gao Tie-Gang; Chen Zeng-Qiang; Yuan Zhu-Zhi

    2005-01-01

    A new kind of generalized reduced-order synchronization of different chaotic systems is proposed in this paper.It is shown that dynamical evolution of third-order oscillator can be synchronized with the canonical projection of a fourth-order chaotic system generated through nonsingular states transformation from a cell neural net chaotic system.In this sense, it is said that generalized synchronization is achieved in reduced-order. The synchronization discussed here expands the scope of reduced-order synchronization studied in relevant literatures. In this way, we can achieve generalized reduced-order synchronization between many famous chaotic systems such as the second-order D(u)ffing system and the third-order Lorenz system by designing a fast slide mode controller. Simulation results are provided to verify the operation of the designed synchronization.

  4. Transition to complete synchronization via near-synchronization in two coupled chaotic neurons

    Institute of Scientific and Technical Information of China (English)

    Wang Qing-Yun; Lu Qi-Shao; Wang Hai-Xia

    2005-01-01

    The synchronization transition in two coupled chaotic Morris-Lecar (ML) neurons with gap junction is studied with the coupling strength increasing. The conditional Lyapunov exponents, along with the synchronization errors are calculated to diagnose synchronization of two coupled chaotic ML neurons. As a result, it is shown that the increase in the coupling strength leads to incoherence, then induces a transition process consisting of three different synchronization states in succession, namely, burst synchronization, near-synchronization and embedded burst synchronization, and achieves complete synchronization of two coupled neurons finally. These sequential transitions to synchronization reveal a new transition route from incoherence to complete synchronization in coupled systems with multi-time scales.

  5. Imaging living cells with a combined high-resolution multi-photon-acoustic microscope

    Science.gov (United States)

    Schenkl, Selma; Weiss, Eike; Stark, Martin; Stracke, Frank; Riemann, Iris; Lemor, Robert; König, Karsten

    2007-02-01

    With increasing demand for in-vivo observation of living cells, microscope techniques that do not need staining become more and more important. In this talk we present a combined multi-photon-acoustic microscope with the possibility to measure synchronously properties addressed by ultrasound and two-photon fluorescence. Ultrasound probes the local mechanical properties of a cell, while the high resolution image of the two-photon fluorescence delivers insight in cell morphology and activity. In the acoustic part of the microscope an ultrasound wave, with a frequency of GHz, is focused by an acoustic sapphire lens and detected by a piezo electric transducer assembled to the lens. The achieved lateral resolution is in the range of 1μm. Contrast in the images arises mainly from the local absorption of sound in the cells, related to properties, such as mass density, stiffness and viscose damping. Additionally acoustic microscopy can access the cell shape and the state of the cell membrane as it is a intrinsic volume scanning technique.The optical part bases on the emission of fluorescent biomolecules naturally present in cells (e.g. NAD(P)H, protophorphyrin IX, lipofuscin, melanin). The nonlinear effect of two-photon absorption provides a high lateral and axial resolution without the need of confocal detection. In addition, in the near-IR cell damages are drastically reduced in comparison to direct excitation in the visible or UV. Both methods can be considered as minimal invasive, as they relay on intrinsic contrast mechanisms and dispense with the need of staining. First results on living cells are presented and discussed.

  6. Time synchronization in ad-hoc wireless sensor networks

    Science.gov (United States)

    Sharma, Nishant

    2013-06-01

    Advances in micro-electronics and developments in the various technologies have given birth to this era of wireless sensor networks. A sensor network is the one which provides information about the surrounding environment by sensing it and clock synchronization in wireless sensor networks plays a vital role to maintain the integrity of entire network. In this paper two major low energy consumption clock synchronization algorithms, Reference Broadcast Synchronization (RBS) and Timing-Sync Protocol for Sensor Networks (TPSN) are simulated, which result in high level of accuracy, reliability, handles substantially greater node densities, supports mobility, and hence perform well under all possible conditions.

  7. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle

    Science.gov (United States)

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-01-01

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highly active in nocodazole-induced, double-thymidine synchronization released as well as naturally occurring mitosis in HeLa cells. Multiple autophagy proteins are upregulated in mitosis and the increased Beclin-1 level likely contributes to the active autophagic flux in early mitosis. It is interesting that although the autophagic flux is active throughout the cell cycle, early mitosis and S phase have relatively higher autophagic flux than G1 and late G2 phases, which might be helpful to degrade the damaged organelles and provide energy during S phase and mitosis. PMID:27213594

  8. Synchronization of P Systems with Simplex Channels

    CERN Document Server

    Ipate, Florentin; Niculescu, Ionut-Mihai; Stefan, Cristian

    2011-01-01

    We solve the Firing Squad Synchronization Problem (FSSP), for P systems based on digraphs with simplex channels, where communication is restricted by the direction of structural arcs. Previous work on FSSP for P systems focused exclusively on P systems with duplex channels, where communication between parents and children is bidirectional. Our P solution, the first for simplex channels, requires cell IDs, strongly connected digraphs and some awareness of the local topology (such as each cell's outdegree)---we argue that these requirements are necessary. Compared to the known solutions for cellular automata, our solution is substantially simpler and faster.

  9. The role of local field potential coupling in epileptic synchronization

    Institute of Scientific and Technical Information of China (English)

    Jiongxing Wu; Heng Yang; Yufeng Peng; Liangjuan Fang; Wen Zheng; Zhi Song

    2013-01-01

    This review hopes to clearly explain the following viewpoints: (1) Neuronal synchronization underlies brain functioning, and it seems possible that blocking excessive synchronization in an epileptic neural network could reduce or even control seizures. (2) Local field potential coupling is a very common phenomenon during synchr in networks. Removal of neurons or neuronal networks that are coupled can significantly alter the extracellular field potential. Interventions of coupling mediated by local field potentials could result in desynchronization of epileptic seizures. (3) The synchronized electrical activity generated by neurons is sensitive to changes in the size of the extracellular space, which affects the efficiency of field potential transmission and the threshold of cell excitability. (4) Manipulations of the field potential fluctuations could help block synchronization at seizure onset.

  10. Inducverters: PLL-Less Converters with Auto-Synchronization and Emulated Inertia Capability

    DEFF Research Database (Denmark)

    Ashabani, Mahdi; Freijedo Fernandez, Francisco Daniel; Golestan, Saeed

    2016-01-01

    -locked-loop (PLL). Therefore, it offers a simpler and more reliable control strategy with improved performance, as it provides real auto-start and auto-synchronization with a grid without the need for grid voltage information. A current damping/synchronization unit enables grid auto-synchronization by using local...... impedance. The controller also offers stable and high-performance synchronization and operation under unbalanced and/or distorted grid conditions. The work beside synchronous current converters give a bird’s eye view to research in the new area of PLL-less and virtual inertia-based operation of VSCs...

  11. Chaotic synchronization based on nonlinear state-observer and its application in secure communication

    Institute of Scientific and Technical Information of China (English)

    CHEN Ming-jie; LI Dian-pu; ZHANG Ai-jun

    2004-01-01

    Chaotic synchronization is a branch of chaotic control. Nowadays, the research and application of chaotic synchronization have become a hot topic and one of the development directions is for the research on chaos. In this paper, a universal nonlinear stateobserver is presented for a class of universal chaotic systems to realize the chaotic synchronization, according to the theory of state-observer in the modern control theory. And theoretic analysis and simulation results have illustrated the validity of the approach. Moreover, the approach of synchronization proposed in this paper is very easy, flexible and universal with high synchronization precision.When the approach is applied to secure communication, the results are satisfying.

  12. Simulation of chaotic synchronization communication system based on incoherent optical feedback and injection

    Institute of Scientific and Technical Information of China (English)

    MA Jun-shan; GU Wen-hua

    2006-01-01

    In this paper,we numerically study chaotic synchronization communication system based on incoherent optical feedback and incoherent optical injection.The characteristics of the system,such as synchronization time,synchronization error,chaos shift keying encoding/decoding and modulation rate are analyzed.The results of simulation show that the system has good synchronization quality and good abilities of robust secure.The synchronization time is 1ns and the chaos shift keying encoding can reach a high rate of 1 Gbit/s.The system has a good ability of robust secure.It proves the feasibility of the optical secure communication.

  13. Synchronization in an evolving network

    CERN Document Server

    Singh, R K

    2015-01-01

    In this work we study the dynamics of Kuramoto oscillators on a stochastically evolving network whose evolution is governed by the phases of the individual oscillators and degree distribution. Synchronization is achieved after a threshold connection density is reached. This cumulative effect of topology and dynamics has many real-world implications, where synchronization in a system emerges as a collective property of its components in a self-organizing manner. The synchronous state remains stable as long as the connection density remains above the threshold value, with additional links providing resilience against network fluctuations.

  14. Distributed synchronization for Beyond 4G Indoor Femtocells

    DEFF Research Database (Denmark)

    Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão; Mahmood, Nurul Huda

    2013-01-01

    strict time synchronization between the cells. This paper deals with distributed runtime synchronization for Beyond 4G femtocells. A simple random scheduling solution for the clock distribution messages is proposed, as well as different clock update mechanisms. Simulation results for a dense cell...... scenario with two stripes of apartments show that a ‘multiplicative clock update’ exhibits an initial large time divergence among neighbor cells, but is able to achieve a lower long-term error floor than ‘additive clock update’. Practical implications of the residual time misalignment on the Beyond 4G...

  15. Nonlinear Chemical Dynamics and Synchronization

    Science.gov (United States)

    Li, Ning

    Alan Turing's work on morphogenesis, more than half a century ago, continues to motivate and inspire theoretical and experimental biologists even today. That said, there are very few experimental systems for which Turing's theory is applicable. In this thesis we present an experimental reaction-diffusion system ideally suited for testing Turing's ideas in synthetic "cells" consisting of microfluidically produced surfactant-stabilized emulsions in which droplets containing the Belousov-Zhabotinsky (BZ) oscillatory chemical reactants are dispersed in oil. The BZ reaction has become the prototype of nonlinear dynamics in chemistry and a preferred system for exploring the behavior of coupled nonlinear oscillators. Our system consists of a surfactant stabilized monodisperse emulsion of drops of aqueous BZ solution dispersed in a continuous phase of oil. In contrast to biology, here the chemistry is understood, rate constants are measured and interdrop coupling is purely diffusive. We explore a large set of parameters through control of rate constants, drop size, spacing, and spatial arrangement of the drops in lines and rings in one-dimension (1D) and hexagonal arrays in two-dimensions (2D). The Turing model is regarded as a metaphor for morphogenesis in biology but not for prediction. Here, we develop a quantitative and falsifiable reaction-diffusion model that we experimentally test with synthetic cells. We quantitatively establish the extent to which the Turing model in 1D describes both stationary pattern formation and temporal synchronization of chemical oscillators via reaction-diffusion and in 2D demonstrate that chemical morphogenesis drives physical differentiation in synthetic cells.

  16. Synchronicity in predictive modelling: a new view of data assimilation

    Science.gov (United States)

    Duane, G. S.; Tribbia, J. J.; Weiss, J. B.

    2006-11-01

    The problem of data assimilation can be viewed as one of synchronizing two dynamical systems, one representing "truth" and the other representing "model", with a unidirectional flow of information between the two. Synchronization of truth and model defines a general view of data assimilation, as machine perception, that is reminiscent of the Jung-Pauli notion of synchronicity between matter and mind. The dynamical systems paradigm of the synchronization of a pair of loosely coupled chaotic systems is expected to be useful because quasi-2D geophysical fluid models have been shown to synchronize when only medium-scale modes are coupled. The synchronization approach is equivalent to standard approaches based on least-squares optimization, including Kalman filtering, except in highly non-linear regions of state space where observational noise links regimes with qualitatively different dynamics. The synchronization approach is used to calculate covariance inflation factors from parameters describing the bimodality of a one-dimensional system. The factors agree in overall magnitude with those used in operational practice on an ad hoc basis. The calculation is robust against the introduction of stochastic model error arising from unresolved scales.

  17. Synchronicity in predictive modelling: a new view of data assimilation

    Directory of Open Access Journals (Sweden)

    G. S. Duane

    2006-01-01

    Full Text Available The problem of data assimilation can be viewed as one of synchronizing two dynamical systems, one representing "truth" and the other representing "model", with a unidirectional flow of information between the two. Synchronization of truth and model defines a general view of data assimilation, as machine perception, that is reminiscent of the Jung-Pauli notion of synchronicity between matter and mind. The dynamical systems paradigm of the synchronization of a pair of loosely coupled chaotic systems is expected to be useful because quasi-2D geophysical fluid models have been shown to synchronize when only medium-scale modes are coupled. The synchronization approach is equivalent to standard approaches based on least-squares optimization, including Kalman filtering, except in highly non-linear regions of state space where observational noise links regimes with qualitatively different dynamics. The synchronization approach is used to calculate covariance inflation factors from parameters describing the bimodality of a one-dimensional system. The factors agree in overall magnitude with those used in operational practice on an ad hoc basis. The calculation is robust against the introduction of stochastic model error arising from unresolved scales.

  18. Vacuum MOCVD fabrication of high efficience cells

    Science.gov (United States)

    Partain, L. D.; Fraas, L. M.; Mcleod, P. S.; Cape, J. A.

    1985-01-01

    Vacuum metal-organic-chemical-vapor-deposition (MOCVD) is a new fabrication process with improved safety and easier scalability due to its metal rather than glass construction and its uniform multiport gas injection system. It uses source materials more efficiently than other methods because the vacuum molecular flow conditions allow the high sticking coefficient reactants to reach the substrates as undeflected molecular beams and the hot chamber walls cause the low sticking coefficient reactants to bounce off the walls and interact with the substrates many times. This high source utilization reduces the materials costs power device and substantially decreases the amounts of toxic materials that must be handled as process effluents. The molecular beams allow precise growth control. With improved source purifications, vacuum MOCVD has provided p GaAs layers with 10-micron minority carrier diffusion lengths and GaAs and GaAsSb solar cells with 20% AMO efficiencies at 59X and 99X sunlight concentration ratios. Mechanical stacking has been identified as the quickest, most direct and logical path to stacked multiple-junction solar cells that perform better than the best single-junction devices. The mechanical stack is configured for immediate use in solar arrays and allows interconnections that improve the system end-of-life performance in space.

  19. The position of DNA cleavage by TALENs and cell synchronization influences the frequency of gene editing directed by single-stranded oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Natalia Rivera-Torres

    Full Text Available With recent technological advances that enable DNA cleavage at specific sites in the human genome, it may now be possible to reverse inborn errors, thereby correcting a mutation, at levels that could have an impact in a clinical setting. We have been developing gene editing, using single-stranded DNA oligonucleotides (ssODNs, as a tool to direct site specific single base changes. Successful application of this technique has been demonstrated in many systems ranging from bacteria to human (ES and somatic cells. While the frequency of gene editing can vary widely, it is often at a level that does not enable clinical application. As such, a number of stimulatory factors such as double-stranded breaks are known to elevate the frequency significantly. The majority of these results have been discovered using a validated HCT116 mammalian cell model system where credible genetic and biochemical readouts are available. Here, we couple TAL-Effector Nucleases (TALENs that execute specific ds DNA breaks with ssODNs, designed specifically to repair a missense mutation, in an integrated single copy eGFP gene. We find that proximal cleavage, relative to the mutant base, is key for enabling high frequencies of editing. A directionality of correction is also observed with TALEN activity upstream from the target base being more effective in promoting gene editing than activity downstream. We also find that cells progressing through S phase are more amenable to combinatorial gene editing activity. Thus, we identify novel aspects of gene editing that will help in the design of more effective protocols for genome modification and gene therapy in natural genes.

  20. Incoherence-Mediated Remote Synchronization

    Science.gov (United States)

    Zhang, Liyue; Motter, Adilson E.; Nishikawa, Takashi

    2017-04-01

    In previously identified forms of remote synchronization between two nodes, the intermediate portion of the network connecting the two nodes is not synchronized with them but generally exhibits some coherent dynamics. Here we report on a network phenomenon we call incoherence-mediated remote synchronization (IMRS), in which two noncontiguous parts of the network are identically synchronized while the dynamics of the intermediate part is statistically and information-theoretically incoherent. We identify mirror symmetry in the network structure as a mechanism allowing for such behavior, and show that IMRS is robust against dynamical noise as well as against parameter changes. IMRS may underlie neuronal information processing and potentially lead to network solutions for encryption key distribution and secure communication.

  1. Synchronous identification of friendly targets

    Science.gov (United States)

    Telle, John M.; Roger, Stutz A.

    1998-01-01

    A synchronous communication targeting system for use in battle. The present invention includes a transceiver having a stabilizing oscillator, a synchronous amplifier and an omnidirectional receiver, all in electrical communication with each other. A remotely located beacon is attached to a blackbody radiation source and has an amplitude modulator in electrical communication with a optical source. The beacon's amplitude modulator is set so that the optical source transmits radiation frequency at approximately the same or lower amplitude than that of the blackbody radiation source to which the beacon is attached. The receiver from the transceiver is adapted to receive frequencies approximately at or below blackbody radiation signals and sends such signals to the synchronous amplifier. The synchronous amplifier then rectifies and amplifies those signals which correspond to the predetermined frequency to therefore identify whether the blackbody radiation source is friendly or not.

  2. Principles of synchronous digital hierarchy

    CERN Document Server

    Jain, Rajesh Kumar

    2012-01-01

    The book presents the current standards of digital multiplexing, called synchronous digital hierarchy, including analog multiplexing technologies. It is aimed at telecommunication professionals who want to develop an understanding of digital multiplexing and synchronous digital hierarchy in particular and the functioning of practical telecommunication systems in general. The text includes all relevant fundamentals and provides a handy reference for problem solving or defining operations and maintenance strategies. The author covers digital conversion and TDM principles, line coding and digital

  3. Chaotic synchronization via linear controller

    Institute of Scientific and Technical Information of China (English)

    Chen Feng-Xiang; Zhang Wei-Dong

    2007-01-01

    A technical framework of constructing a linear controller for chaotic synchronization by utilizing the stability theory of cascade-connected system is presented. Based on the method developed in the paper, two simple and linear feedback controllers, as examples, are derived for the synchronization of Liu chaotic system and Duffing oscillator, respectively.This method is quite flexible in constructing a control law. Its effectiveness is also illustrated by the simulation results.

  4. Synchronized Swimming of Two Fish

    Science.gov (United States)

    Koumoutsakos, Petros; Novati, Guido; Abbati, Gabriele; Hejazialhosseini, Babak; van Rees, Wim

    2015-11-01

    We present simulations of two, self-propelled, fish-like swimmers that perform synchronized moves in a two-dimensional, viscous fluid. The swimmers learn to coordinate by receiving a reward for their synchronized actions. We analyze the swimming patterns emerging for different rewards in terms of their hydrodynamic efficiency and artistic impression. European Research Council (ERC) Advanced Investigator Award (No. 2-73985-14).

  5. Photonic Cavity Synchronization of Nanomechanical Oscillators

    OpenAIRE

    Bagheri, Mahmood; Poot, Menno; Fan, Linran; Marquardt, Florian; Tang, Hong X.

    2013-01-01

    Synchronization in oscillatory systems is a frequent natural phenomenon and is becoming an important concept in modern physics. Nanomechanical resonators are ideal systems for studying synchronization due to their controllable oscillation properties and engineerable nonlinearities. Here we demonstrate synchronization of two nanomechanical oscillators via a photonic resonator, enabling optomechanical synchronization between mechanically isolated nanomechanical resonators. Optical backaction gi...

  6. VOLTAGE REGULATORS OF SYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-06-01

    Full Text Available Synchronous generators are the primary source of electrical power autonomous electrosupply systems, including backup systems. They are also used in a structure of rotating electricity converters and are widely used in renewable energy as part of wind power plants of small, mini and micro hydroelectric plants. Increasing the speed and the accuracy of the system of the voltage regulation of synchronous generators is possible due to the development of combined systems containing more stabilizers. The article illustrates the functional schemes of circuit voltage stabilizers and frequency synchronous generators (with electromagnetic excitation and permanent magnet excitation and describes the features of their work, including two and three-aggregate rotating converters of electricity used in uninterruptible power supply systems. To improve the technical characteristics of the system of stabilization we have proposed functional solutions for stabilizers of synchronous generators made on the base of direct frequency converters and using a transformer with a rotating magnetic field. To improve the reliability of and to improve the operational characteristics of the autonomous independent sources of electricity we suggest creating the main functional blocks and the elements of the stabilization system in a modular way. The functional circuit solutions of voltage regulators of synchronous generators and the characteristics of their work considered in the article, are able to improve the efficiency of pre-design work in the development of new technical solutions for stabilizing the voltage and the frequency in synchronous generators of electrosupply autonomous systems

  7. Quantum synchronization and quantum state sharing in an irregular complex network

    Science.gov (United States)

    Li, Wenlin; Li, Chong; Song, Heshan

    2017-02-01

    We investigate the quantum synchronization phenomenon of the complex network constituted by coupled optomechanical systems and prove that the unknown identical quantum states can be shared or distributed in the quantum network even though the topology is varying. Considering a channel constructed by quantum correlation, we show that quantum synchronization can sustain and maintain high levels in Markovian dissipation for a long time. We also analyze the state-sharing process between two typical complex networks, and the results predict that linked nodes can be directly synchronized, but the whole network will be synchronized only if some specific synchronization conditions are satisfied. Furthermore, we give the synchronization conditions analytically through analyzing network dynamics. This proposal paves the way for studying multi-interaction synchronization and achieving effective quantum information processing in a complex network.

  8. Quantum synchronization and quantum state sharing in an irregular complex network.

    Science.gov (United States)

    Li, Wenlin; Li, Chong; Song, Heshan

    2017-02-01

    We investigate the quantum synchronization phenomenon of the complex network constituted by coupled optomechanical systems and prove that the unknown identical quantum states can be shared or distributed in the quantum network even though the topology is varying. Considering a channel constructed by quantum correlation, we show that quantum synchronization can sustain and maintain high levels in Markovian dissipation for a long time. We also analyze the state-sharing process between two typical complex networks, and the results predict that linked nodes can be directly synchronized, but the whole network will be synchronized only if some specific synchronization conditions are satisfied. Furthermore, we give the synchronization conditions analytically through analyzing network dynamics. This proposal paves the way for studying multi-interaction synchronization and achieving effective quantum information processing in a complex network.

  9. Synchronization of Integrated Systems on a Chip

    Directory of Open Access Journals (Sweden)

    González-Díaz O.

    2012-04-01

    Full Text Available In the present paper, the non-conventional interconnected and coupled ring oscillators approach working as clock distribution networks to synchronize electronic systems on a chip (SoC is proposed. Typical CMOS (Complementary Metal-Oxide Semiconductor N-well 0.35 µm Austria Micro Systems process parameters were used for conventional and non-conventional clock distribution nets design and simulation. Experimental results from local and global clock distribution networks fabricated using a CMOS 0.35 µm process show that the use of interconnected rings arrays, as globally asynchronous locally synchronous (GALS clock distribution networks, represent an appropriate approach due to good performance regarding scalability, low clock-skew, high-speed, faults tolerant and robust under process variations, regularity, and modularity.

  10. Space and the Synchronic A-Ram

    CERN Document Server

    Berka, Alex V

    2010-01-01

    Space is a circuit oriented, spatial programming language designed to exploit the massive parallelism available in a novel formal model of computation called the Synchronic A-Ram, and physically related FPGA and reconfigurable architectures. Space expresses variable grained MIMD parallelism, is modular, strictly typed, and deterministic. Barring operations associated with memory allocation and compilation, modules cannot access global variables, and are referentially transparent. At a high level of abstraction, modules exhibit a small, sequential state transition system, aiding verification. Space deals with communication, scheduling, and resource contention issues in parallel computing, by resolving them explicitly in an incremental manner, module by module, whilst ascending the ladder of abstraction. Whilst the Synchronic A-Ram model was inspired by linguistic considerations, it is also put forward as a formal model for reconfigurable digital circuits. A programming environment has been developed, that inco...

  11. Studying the role of synchronized and chaotic spiking neural ensembles in neural information processing.

    Science.gov (United States)

    Rosselló, Josep L; Canals, Vicens; Oliver, Antoni; Morro, Antoni

    2014-08-01

    The brain is characterized by performing many diverse processing tasks ranging from elaborate processes such as pattern recognition, memory or decision making to more simple functionalities such as linear filtering in image processing. Understanding the mechanisms by which the brain is able to produce such a different range of cortical operations remains a fundamental problem in neuroscience. Here we show a study about which processes are related to chaotic and synchronized states based on the study of in-silico implementation of Stochastic Spiking Neural Networks (SSNN). The measurements obtained reveal that chaotic neural ensembles are excellent transmission and convolution systems since mutual information between signals is minimized. At the same time, synchronized cells (that can be understood as ordered states of the brain) can be associated to more complex nonlinear computations. In this sense, we experimentally show that complex and quick pattern recognition processes arise when both synchronized and chaotic states are mixed. These measurements are in accordance with in vivo observations related to the role of neural synchrony in pattern recognition and to the speed of the real biological process. We also suggest that the high-level adaptive mechanisms of the brain that are the Hebbian and non-Hebbian learning rules can be understood as processes devoted to generate the appropriate clustering of both synchronized and chaotic ensembles. The measurements obtained from the hardware implementation of different types of neural systems suggest that the brain processing can be governed by the superposition of these two complementary states with complementary functionalities (nonlinear processing for synchronized states and information convolution and parallelization for chaotic).

  12. High efficiency low cost GaAs/Ge cell technology

    Science.gov (United States)

    Ho, Frank

    1990-01-01

    Viewgraphs on high efficiency low cost GaAs/Ge cell technology are presented. Topics covered include: high efficiency, low cost GaAs/Ge solar cells; advantages of Ge; comparison of typical production cells for space applications; panel level comparisons; and solar cell technology trends.

  13. Pulse Ejection Presentation System Synchronized with Breathing

    Science.gov (United States)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  14. Phase synchronization of oscillations in cardiovascular and respiratory systems in humans

    Science.gov (United States)

    Tankanag, Arina V.; Grinevich, Andrey A.; Tikhonova, Irina V.; Chaplygina, Alina V.; Chemeris, Nikolay K.

    2017-04-01

    Phase synchronization between blood flow oscillations of left and right forearm skin sites, heart rate variability (HRV) and breath rate were studied from healthy volunteers at rest. The degree of synchronization between the phases of the analyzed signals was estimated from the value of the wavelet phase coherence. High medians of values of phase wavelet coherence function were obtained for the endothelial, neurogenic, myogenic and cardiac intervals. Significant phase synchronization were demonstrated between HRV and skin blood flow oscillations in both left and right forearms in a wide frequency range from 0.04 to 0.4 Hz. Six participants exhibited low phase synchronization (rate and HRV, while nine participants had high phase synchronization (> 0.5). This distribution was not affected by the sex or sympathovagal status of volunteers. Participants with low phase synchronization between breath rate and HRV featured low phase synchronization (rate and blood flow oscillations in both forearms. Contrariwise, in subjects with high phase synchronization between respiratory rhythm and HRV both low and high phase synchronization between breath rate and blood flow oscillations in both forearms was observed. The results obtained allow us to suggest that the organism possesses a mechanism mediating the synchronization of blood flow oscillations in the skin microvasculature with all other periodical processes across the cardiovascular system, in particular, with HRV and breath rate over a wide frequency range.

  15. Treatment of multiple synchronous misdiagnosed renal cell cancers in a young patient affected by a "de novo" Von Hippel-Lindau syndrome.

    Science.gov (United States)

    Allasia, Marco; Battaglia, Antonino; Pasini, Barbara; Gazzera, Carlo; Calandri, Marco; Bosio, Andrea; Gontero, Paolo; Destefanis, Paolo

    2017-02-28

    Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited syndrome occurring in one out of 36,000 live births. Diagnosis could be a challenge in patients with no familial VHL history. Renal cancer (RCC) represents one of the most important manifestations. RCC is usually recurrent and multifocal. Actually treating RCC in VHL patients represent a clinical dilemma: the oncological outcomes must be balanced against renal function preservation. A young man with a negative familial history was referred to our department with seven misdiagnosed renal masses. VHL disease was determined through genetic test. The multiple RCCs were treated by surgery and percutaneous thermal ablation by radiofrequency ablation (RFA) with complete control of RCC and no impairment of renal function. This case history confirms that VHL disease has to be suspected in young patients with evidence of synchronous multiple renal masses and in presence of specific clinical criteria.RFA appears to be safe in terms of oncological radicalism and in renal function preservation.In hereditary RCC, we should purpose, whenever it is possible, minimally invasive treatment in terms of low hospital stay and a minimal loss of renal tissue.

  16. Unidirectional synchronization of Hodgkin-Huxley neurons

    Energy Technology Data Exchange (ETDEWEB)

    Cornejo-Perez, Octavio [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: octavio@ipicyt.edu.mx; Femat, Ricardo [Division de Matematicas Aplicadas y Sistemas, Computacionales, IPICYT, Apdo. Postal 3-74 Tangamanga, 78231 San Luis Potosi (Mexico)]. E-mail: rfemat@ipicyt.edu.mx

    2005-07-01

    Synchronization dynamics of two noiseless Hodgkin-Huxley (HH) neurons under the action of feedback control is studied. The spiking patterns of the action potentials evoked by periodic external modulations attain synchronization states under the feedback action. Numerical simulations for the synchronization dynamics of regular-irregular desynchronized spiking sequences are displayed. The results are discussed in context of generalized synchronization. It is also shown that the HH neurons can be synchronized in face of unmeasured states.

  17. Impulsive Synchronization of Discrete Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    郑永爱; 年漪蓓; 刘曾荣

    2003-01-01

    Impulsive synchronization of two chaotic maps is reformulated as impulsive control of the synchronization error system. We then present a theorem on the asymptotic synchronization of two chaotic maps by using synchronization impulses with varying impulsive intervals. As an example and application of the theorem, we derives some sufficient conditions for the synchronization of two chaotic Lozi maps via impulsive control. The effectiveness of this approach has been demonstrated with chaotic Lozi map.

  18. Impulsive Synchronization of Laser Plasma System

    Institute of Scientific and Technical Information of China (English)

    LI Yang; LIAO Xiao-Feng; LI Chuan-Dong; CHEN Guo

    2007-01-01

    The issue of impulsive synchronization of the coupled chaotic laser plasma system is investigated. A new framework for impulsive synchronization of such chaotic systems is presented, which makes the synchronization error system a linear impulsive control system. We derive some sufficient conditions for the synchronization of a laser plasma system via impulsive control with the varying impulsive intervals, which allows us to derive the impulsive synchronization law easily. To illustrate the effectiveness of the proposed results, two numerical examples are given.

  19. Outer Synchronization of Complex Networks by Impulse

    Institute of Scientific and Technical Information of China (English)

    孙文; 燕子宗; 陈士华; 吕金虎

    2011-01-01

    This paper investigates outer synchronization of complex networks, especially, outer complete synchronization and outer anti-synchronization between the driving network and the response network. Employing the impulsive control method which is uncontinuous, simple, efficient, low-cost and easy to implement in practical applications, we obtain some sufficient conditions of outer complete synchronization and outer anti-synchronization between two complex networks. Numerical simulations demonstrate the effectiveness of the proposed impulsive control scheme.

  20. Hybrid synchronization of hyperchaotic Lu system

    Indian Academy of Sciences (India)

    K Sebastian Sudheer; M Sabir

    2009-10-01

    In this paper, we study the hybrid synchronization between two identical hyperchaotic Lu systems. Hybrid synchronization of hyperchaotic Lu system is achieved through synchronization of two pairs of states and anti-synchronization of the other two pairs of states. Active controls are designed to achieve hybrid synchronization between drive and response systems using the sum and difference of relevant variables of the chaotic systems. Numerical simulations are presented to evaluate the analysis and effectiveness of the controllers.

  1. Synchronization in an array of coupled Boolean networks

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rui, E-mail: rui.li@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Chu, Tianguang, E-mail: chutg@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China)

    2012-10-01

    This Letter presents an analytical study of synchronization in an array of coupled deterministic Boolean networks. A necessary and sufficient criterion for synchronization is established based on algebraic representations of logical dynamics in terms of the semi-tensor product of matrices. Some basic properties of a synchronized array of Boolean networks are then derived for the existence of transient states and the upper bound of the number of fixed points. Particularly, an interesting consequence indicates that a “large” mismatch between two coupled Boolean networks in the array may result in loss of synchrony in the entire system. Examples, including the Boolean model of coupled oscillations in the cell cycle, are given to illustrate the present results. -- Highlights: ► We analytically study synchronization in an array of coupled Boolean networks. ► The study is based on the algebraic representations of logical dynamics. ► A necessary and sufficient algebraic criterion for synchronization is established. ► It reveals some basic properties of a synchronized array of Boolean networks. ► A large mismatch between two coupled networks may result in the loss of synchrony.

  2. 电动汽车用永磁同步电机驱动系统的高性能控制%High Performance Control of Permanent Magnet Synchronous Motor Drive Systems Used in Electric Car

    Institute of Scientific and Technical Information of China (English)

    朱鲁佳

    2015-01-01

    针对电动汽车用永磁同步电机驱动系统的特点,以内置式永磁同步电机为控制对象,设计了以TC1797为主控芯片的硬件驱动系统。软件控制中采用最大转矩电流控制结合电压负反馈闭环的弱磁控制的方式,使得整个驱动系统起动转矩大、调速范围宽、功率密度和效率高。搭建电动汽车用永磁同步电机驱动系统进行测试验证。试验结果表明该驱动系统弱磁扩速倍数可达3.5;系统的峰值效率达到95%,系统效率>85%的区域超过80%,验证了该控制技术的高效性和可行性。%Due to the characteristics of permanent magnet synchronous motor drive system used in electric car, with the interior permanent magnet synchronous motor as the control object, designed the hardware drive system which was used the TC1797 as main control chip, used maximum torque per ampere control and field weakening as soft control strategy, then made the whole driving system have big startup torque, wide speed range, high power density and efficiency. Finally set up the permanent magnet synchronous motor drive system which was used in electric car for test validation. The test results showed that the drive system of field weakening expansion speed ratio could reach 3. 5, system peak efficiency could reached 95% , the area which the system efficiency was more than 85% can reach more than 80% , this proved the efficiency and feasibility of the control technology.

  3. Noise-driven Synchronization in Coupled Map Lattices

    CERN Document Server

    Baroni, L; Torcini, A

    1999-01-01

    Synchronization is shown to occur in spatially extended systems under the effect of additive spatio-temporal noise. In analogy to low dimensional systems, synchronized states are observable only if the maximum Lyapunov exponent $\\Lambda$ is negative. However, a sufficiently high noise level can lead, in map with finite domain of definition, to nonlinear propagation of information, even in non chaotic systems. In this latter case the transition to synchronization is ruled by a new ingredient : the propagation velocity of information $V_F$. As a general statement, we can affirm that if $V_F$ is finite the time needed to achieve a synchronized trajectory grows exponentially with the system size $L$, while it increases logarithmically with $L$ when, for sufficiently large noise amplitude, $V_F = 0$ .

  4. 基于高阶高增益滑模观测器的混沌同步研究%Higher-order High-gain Sliding Mode Observer Based on Chaos Synchronization

    Institute of Scientific and Technical Information of China (English)

    张良; 朱芳来

    2013-01-01

    基于驱动响应结构,针对一类混沌系统,提出了一种高阶高增益响应系统的设计方法.基于增维的思想,所提出的响应系统不仅能估计出系统的状态,还能估计出状态的微分.基于混沌同步,考虑了该类混沌系统的基于混沌同步的保密机制,在发射器和接受器达到同步的前提下,提出了一种新的信号还原的方法.该方法没有用到系统的微分信息,同时对强时变信号可以还原.针对一个SQCF混沌系统进行仿真实验,结果表明了方法的有效性.%Within the drive-response configuration, this paper develops a higher-order high-gain sliding mode observer used as response system for a class of chaotic system. By the technique of augmenting the dimension of original system, the proposed response system is able to estimate not only the drive system' s states themselves but also their derivatives. Based on chaotic synchronization, the chaos-based secure communication mechanism is considered. A new signal recovery method is proposed after the receiver has been synchronized by the transmitter. Our method is able to recover strong-time-varying signals without using any differential information of the drive system. The SQCF chaotic system is considered as an illustrative example to demonstrate the effectiveness of the proposed approaches.

  5. Review of silicon solar cells for high concentrations

    Science.gov (United States)

    Schwartz, R. J.

    1982-06-01

    The factors that limit the performance of high concentration silicon solar cells are reviewed. The design of a conventional high concentration cell is discussed, together with the present state of the art. Unconventional cell designs that have been proposed to overcome the limitations of the conventional design are reviewed and compared. The current status of unconventional cells is reviewed. Among the unconventional cells discussed are the interdigitated back-contact cell, the double-sided cell, the polka dot cell, and the V-groove cell. It is noted that all the designs for unconventional cells require long diffusion lengths for high efficiency operation, even though the demands in this respect are less for those cells with the optical path longer than the diffusion path.

  6. Bodily Synchronization Underlying Joke Telling

    Directory of Open Access Journals (Sweden)

    R. C. Schmidt

    2014-08-01

    Full Text Available Advances in video and time series analysis have greatly enhanced our ability to study the bodily synchronization that occurs in natural interactions. Past research has demonstrated that the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. The present study investigated how the bodily synchronization in a joke telling task is spread across different nested temporal scales. Pairs of participants enacted knock-knock jokes and times series of their bodily activity were recorded. Coherence and relative phase analyses were used to evaluate the synchronization of bodily rhythms for the whole trial as well as at the subsidiary time scales of the whole joke, the setup of the punch line, the two-person exchange and the utterance. The analyses revealed greater than chance entrainment of the joke teller’s and joke responder’s movements at all time scales and that the relative phasing of the teller’s movements led those of the responder at the longer time scales. Moreover, this entrainment was greater when visual information about the partner’s movements was present but was decreased particularly at the shorter time scales when explicit gesturing in telling the joke was performed. In short, the results demonstrate that a complex interpersonal bodily dance occurs during structured conversation interactions and that this dance is constructed from a set of rhythms associated with the nested behavioral structure of the interaction.

  7. Impact of unpredictability on chaos synchronization of vertical-cavity surface-emitting lasers with variable-polarization optical feedback.

    Science.gov (United States)

    Xiang, Shuiying; Pan, Wei; Yan, Lianshan; Luo, Bin; Zou, Xihua; Jiang, Ning; Yang, Lei

    2011-09-01

    The effects of unpredictability degree on the chaos synchronization properties of vertical-cavity surface-emitting lasers with variable-polarization optical feedback are investigated numerically. For variable-polarization optical injection, only low-unpredictability chaos can be well synchronized, while high-unpredictability chaos cannot be synchronized even with large injection strength. On the other hand, for the polarization-preserved optical injection, the synchronization quality is hardly affected by the unpredictability degree, and high-quality synchronization can be achieved for both low- and high-unpredictability chaos due to injection locking.

  8. Circadian rhythms synchronize mitosis in Neurospora crassa.

    Science.gov (United States)

    Hong, Christian I; Zámborszky, Judit; Baek, Mokryun; Labiscsak, Laszlo; Ju, Kyungsu; Lee, Hyeyeong; Larrondo, Luis F; Goity, Alejandra; Chong, Hin Siong; Belden, William J; Csikász-Nagy, Attila

    2014-01-28

    The cell cycle and the circadian clock communicate with each other, resulting in circadian-gated cell division cycles. Alterations in this network may lead to diseases such as cancer. Therefore, it is critical to identify molecular components that connect these two oscillators. However, molecular mechanisms between the clock and the cell cycle remain largely unknown. A model filamentous fungus, Neurospora crassa, is a multinucleate system used to elucidate molecular mechanisms of circadian rhythms, but not used to investigate the molecular coupling between these two oscillators. In this report, we show that a conserved coupling between the circadian clock and the cell cycle exists via serine/threonine protein kinase-29 (STK-29), the Neurospora homolog of mammalian WEE1 kinase. Based on this finding, we established a mathematical model that predicts circadian oscillations of cell cycle components and circadian clock-dependent synchronized nuclear divisions. We experimentally demonstrate that G1 and G2 cyclins, CLN-1 and CLB-1, respectively, oscillate in a circadian manner with bioluminescence reporters. The oscillations of clb-1 and stk-29 gene expression are abolished in a circadian arrhythmic frq(ko) mutant. Additionally, we show the light-induced phase shifts of a core circadian component, frq, as well as the gene expression of the cell cycle components clb-1 and stk-29, which may alter the timing of divisions. We then used a histone hH1-GFP reporter to observe nuclear divisions over time, and show that a large number of nuclear divisions occur in the evening. Our findings demonstrate the circadian clock-dependent molecular dynamics of cell cycle components that result in synchronized nuclear divisions in Neurospora.

  9. Research of Wireless Acquisition and Synchronization of High Density Surface Electromyogram%高密度表面肌电信号无线数据采集同步机制研究

    Institute of Scientific and Technical Information of China (English)

    林上耀; 金文光; 张赛赛

    2016-01-01

    High-spatial resolution,high-quality and high-precision surface Electromyogram(sEMG)is required for High Density surface EMG(HD-sEMG)research. It also raises higher demand of convenience,responsiveness,endur-ance and other aspects of the sEMG acquisition system. Based on consideration of wearability,real-time and high-throughput,a detailed study of system architecture and transport network in the sEMG acquisition system is revealed in this paper. A real-time collection and transmission system is constructed,which is built on modular layered frame, wired USB with wireless WIFI transmission,asynchronous acquisition with synchronous collection,and high-preci-sion synchronization mechanism based on double-buffers and slot switching. To test its function and performance,an evaluation system is developed which has128 sEMG channels with 1 kHz sampling rate and 16 bit data at each chan-nel. As the results show,when 50 ms is used as communication period,the inter-channel synchronization error is less than 320μs,the refresh rate is up to 20 Hz and the average delay at each channel is less than 80 ms.%高密度表面肌电信号研究需要获取高精度、高空间分辨率、高质量的肌电信号,同时也对采集系统的便捷性、响应性、续航能力等方面提出了更高要求.本文在考虑可穿戴性、实时性、高通量等基础上,对sEMG采集系统架构和传输网络设计进行了深入研究,设计了基于模块化分层架构、有线USB结合无线WIFI传输模式、异步采集和同步聚合方法、双缓存和时隙切换的高精度同步机制的实时肌电采集通信系统.为验证系统功能和算法机制,本文还构建了实验平台装置,实现了128通道1 kHz采样率16 bit精度sEMG信号的实时采集、处理和传输.通过测试,在采用通信周期为50 ms下,通道间同步误差小于320μs,刷新率可达20 Hz,系统的平均延时小于80 ms.

  10. Synchronization of endothelial Dll4-Notch dynamics switch blood vessels from branching to expansion

    Science.gov (United States)

    Ubezio, Benedetta; Blanco, Raquel Agudo; Geudens, Ilse; Stanchi, Fabio; Mathivet, Thomas; Jones, Martin L; Ragab, Anan; Bentley, Katie; Gerhardt, Holger

    2016-01-01

    Formation of a regularly branched blood vessel network is crucial in development and physiology. Here we show that the expression of the Notch ligand Dll4 fluctuates in individual endothelial cells within sprouting vessels in the mouse retina in vivo and in correlation with dynamic cell movement in mouse embryonic stem cell-derived sprouting assays. We also find that sprout elongation and branching associates with a highly differential phase pattern of Dll4 between endothelial cells. Stimulation with pathologically high levels of Vegf, or overexpression of Dll4, leads to Notch dependent synchronization of Dll4 fluctuations within clusters, both in vitro and in vivo. Our results demonstrate that the Vegf-Dll4/Notch feedback system normally operates to generate heterogeneity between endothelial cells driving branching, whilst synchronization drives vessel expansion. We propose that this sensitive phase transition in the behaviour of the Vegf-Dll4/Notch feedback loop underlies the morphogen function of Vegfa in vascular patterning. DOI: http://dx.doi.org/10.7554/eLife.12167.001 PMID:27074663

  11. High speed stamping thermal analysis of automotive covering parts and tis application in synchronous engineering%汽车覆盖件高速冲压热分析及其在同步工程中的应用

    Institute of Scientific and Technical Information of China (English)

    刘志氏; 覃开宇; 何述平; 陈立军; 赵凌云

    2012-01-01

    从板料成形时热效应方面出发,推导了板料高速冲压时温升的理论计算公式,研究了高速冲压成形时板料内部的温度分布云图,结合高速冲压生产时出现的产品缺陷与模具失效分析,提出一种基于热分析的同步工程分析方法,为汽车覆盖件高速冲压生产技术研究奠定理论基础。%From the thermal effects when sheet metal forming,deduce calculation of theoretic for temperature raising in high speed stamping,research the temperature distribution cloud for sheet metal interior in high speed stamp modeling,combine the product defects and mold failure analysis appears in high speed stamp production.Put forward synchronous engineering analysis method based on thermal analysis,provide theoritical foundation for production technology research of automotive covering parts high speed stamping.

  12. Active control strategy for synchronization and anti-synchronization of a fractional chaotic financial system

    Science.gov (United States)

    Huang, Chengdai; Cao, Jinde

    2017-05-01

    This paper is concerned with the issues of synchronization and anti-synchronization for fractional chaotic financial system with market confidence by taking advantage of active control approach. Some sufficient conditions are derived to guarantee the synchronization and anti-synchronization for the proposed fractional system. Moreover, the relationship between the order and synchronization(anti-synchronization) is demonstrated numerically. It reveals that synchronization(anti-synchronization) is faster as the order increases. Finally, two illustrative examples are exploited to verify the efficiency of the obtained theoretical results.

  13. Simultaneous Synchronization and Anti-Synchronization of Two Identical New 4D Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    GUO Rong-Wei

    2011-01-01

    We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes, but also anti-synchronizes two identical new 4D chaotic systems. Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.%@@ We investigate the synchronization and anti-synchronization of the new 4D chaotic system and propose a same adaptive controller in the form which not only synchronizes, but also anti-synchronizes two identical new 4D chaotic systems.Numerical simulations verify the correctness and the effectiveness of the proposed theoretical results.

  14. Direct evidence of flagellar synchronization through hydrodynamic interactions

    Science.gov (United States)

    Brumley, Douglas; Polin, Marco; Wan, Kirsty; Goldstein, Raymond

    2013-11-01

    Eukaryotic cilia and flagella exhibit striking coordination, from the synchronous beating of two flagella in Chlamydomonas to the metachronal waves and large-scale flows displayed by carpets of cilia. However, the precise mechanisms responsible for flagellar synchronization remain unclear. We perform a series of experiments involving two individual flagella in a quiescent fluid. Cells are isolated from the colonial alga Volvox carteri, held in place at a fixed distance d, and oriented so that their flagellar beating planes coincide. In this fashion, we are able to explicitly assess the role of hydrodynamics in achieving synchronization. For closely separated cells, the flagella are capable of exhibiting a phase-locked state for thousands of beats at a time, despite significant differences in their intrinsic frequencies. For intermediate values of d, synchronous periods are interrupted by brief phase slips, while for d >> 1 the flagellar phase difference drifts almost linearly with time. The coupling strength extracted through analysis of the synchronization statistics exhibits excellent agreement with hydrodynamic predictions. This study unambiguously reveals that flagella coupled only through hydrodynamics are capable of exhibiting robust synchrony.

  15. Synchronous dual malignancy: Successfully treated cases

    Directory of Open Access Journals (Sweden)

    Agrawal Rashi

    2007-01-01

    Full Text Available The occurrence of a second malignancy in a patient with a known malignant tumour is not uncommon. Synchronous primary malignancies are still unusual We are presenting two cases treated successfully at our centre. Case report 1-A 70 year old female presented to us with lump in right breast for two years and bleeding per vaginum for two years.Histopathology of cervix showed squamous cell carcinoma (large cell non keratinizing and clinical stage was IIIB. HPE mastectomy specimen showed infiltrating duct carcinoma and stage II. Patient was treated with external beam radiotherapy for carcinoma cervix and breast simultaneously and chemotherapy as required. Patient is on regular follow up and clinically no evidence of disease. Case Report 2 -A 40 year old female presented with mild headache off and on for one year, projectile vomiting for three months and right side facial swelling for three months. HPE brain tissue showed astrocytoma grade II and HPE parotid tumour showed low grade muco-epidermoid carcinoma. Patient was treated with surgery first then radiotherapy. Patient is in regular follow up,having no complain,clinically no neurological dysfunction and no evidence of disease at right parotid and neck region. Thus it was concluded that patients responded well to treatment. Treatment strategies in case of synchronous double malignancy depend on treating the malignancy that is more advanced first or sometimes both could be treated simultaneously. In our case we concluded that synchronous double malignancy may be treated successfully. Both sites should be treated fully as if they were occurring separately considering toxicities.

  16. Synchronization in uncertain complex networks

    Science.gov (United States)

    Chen, Maoyin; Zhou, Donghua

    2006-03-01

    We consider the problem of synchronization in uncertain generic complex networks. For generic complex networks with unknown dynamics of nodes and unknown coupling functions including uniform and nonuniform inner couplings, some simple linear feedback controllers with updated strengths are designed using the well-known LaSalle invariance principle. The state of an uncertain generic complex network can synchronize an arbitrary assigned state of an isolated node of the network. The famous Lorenz system is stimulated as the nodes of the complex networks with different topologies. We found that the star coupled and scale-free networks with nonuniform inner couplings can be in the state of synchronization if only a fraction of nodes are controlled.

  17. Cluster synchronization in oscillatory networks

    Science.gov (United States)

    Belykh, Vladimir N.; Osipov, Grigory V.; Petrov, Valentin S.; Suykens, Johan A. K.; Vandewalle, Joos

    2008-09-01

    Synchronous behavior in networks of coupled oscillators is a commonly observed phenomenon attracting a growing interest in physics, biology, communication, and other fields of science and technology. Besides global synchronization, one can also observe splitting of the full network into several clusters of mutually synchronized oscillators. In this paper, we study the conditions for such cluster partitioning into ensembles for the case of identical chaotic systems. We focus mainly on the existence and the stability of unique unconditional clusters whose rise does not depend on the origin of the other clusters. Also, conditional clusters in arrays of globally nonsymmetrically coupled identical chaotic oscillators are investigated. The design problem of organizing clusters into a given configuration is discussed.

  18. Phase Synchronization in Railway Timetables

    CERN Document Server

    Fretter, Christoph; Weihe, Karsten; Müller-Hannemann, Matthias; Hütt, Marc-Thorsten

    2010-01-01

    Timetable construction belongs to the most important optimization problems in public transport. Finding optimal or near-optimal timetables under the subsidiary conditions of minimizing travel times and other criteria is a targeted contribution to the functioning of public transport. In addition to efficiency (given, e.g., by minimal average travel times), a significant feature of a timetable is its robustness against delay propagation. Here we study the balance of efficiency and robustness in long-distance railway timetables (in particular the current long-distance railway timetable in Germany) from the perspective of synchronization, exploiting the fact that a major part of the trains run nearly periodically. We find that synchronization is highest at intermediate-sized stations. We argue that this synchronization perspective opens a new avenue towards an understanding of railway timetables by representing them as spatio-temporal phase patterns. Robustness and efficiency can then be viewed as properties of t...

  19. Extension of Pairwise Broadcast Clock Synchronization for Multicluster Sensor Networks

    Directory of Open Access Journals (Sweden)

    Bruce W. Suter

    2008-01-01

    Full Text Available Time synchronization is crucial for wireless sensor networks (WSNs in performing a number of fundamental operations such as data coordination, power management, security, and localization. The Pairwise Broadcast Synchronization (PBS protocol was recently proposed to minimize the number of timing messages required for global network synchronization, which enables the design of highly energy-efficient WSNs. However, PBS requires all nodes in the network to lie within the communication ranges of two leader nodes, a condition which might not be available in some applications. This paper proposes an extension of PBS to the more general class of sensor networks. Based on the hierarchical structure of the network, an energy-efficient pair selection algorithm is proposed to select the best pairwise synchronization sequence to reduce the overall energy consumption. It is shown that in a multicluster networking environment, PBS requires a far less number of timing messages than other well-known synchronization protocols and incurs no loss in synchronization accuracy. Moreover, the proposed scheme presents significant energy savings for densely deployed WSNs.

  20. Toward Interactive Mobile Synchronous Learning Environment with Context-Awareness Service

    Science.gov (United States)

    Huang, Yueh-Min; Kuo, Yen-Hung; Lin, Yen-Ting; Cheng, Shu-Chen

    2008-01-01

    Mobile synchronous learning is a new challenge in the e-learning domain. While popular mobile communication devices, such as cell phones, cannot directly accommodate traditional synchronous content due to the major limitation of display size, other constraints also restrict convenient interactions while using mobile devices in a synchronous…

  1. Weak synchronization and large-scale collective oscillation in dense bacterial suspensions

    Science.gov (United States)

    Chen, Chong; Liu, Song; Shi, Xia-Qing; Chaté, Hugues; Wu, Yilin

    2017-01-01

    Collective oscillatory behaviour is ubiquitous in nature, having a vital role in many biological processes from embryogenesis and organ development to pace-making in neuron networks. Elucidating the mechanisms that give rise to synchronization is essential to the understanding of biological self-organization. Collective oscillations in biological multicellular systems often arise from long-range coupling mediated by diffusive chemicals, by electrochemical mechanisms, or by biomechanical interaction between cells and their physical environment. In these examples, the phase of some oscillatory intracellular degree of freedom is synchronized. Here, in contrast, we report the discovery of a weak synchronization mechanism that does not require long-range coupling or inherent oscillation of individual cells. We find that millions of motile cells in dense bacterial suspensions can self-organize into highly robust collective oscillatory motion, while individual cells move in an erratic manner, without obvious periodic motion but with frequent, abrupt and random directional changes. So erratic are individual trajectories that uncovering the collective oscillations of our micrometre-sized cells requires individual velocities to be averaged over tens or hundreds of micrometres. On such large scales, the oscillations appear to be in phase and the mean position of cells typically describes a regular elliptic trajectory. We found that the phase of the oscillations is organized into a centimetre-scale travelling wave. We present a model of noisy self-propelled particles with strictly local interactions that accounts faithfully for our observations, suggesting that self-organized collective oscillatory motion results from spontaneous chiral and rotational symmetry breaking. These findings reveal a previously unseen type of long-range order in active matter systems (those in which energy is spent locally to produce non-random motion). This mechanism of collective oscillation may

  2. A review of high-efficiency silicon solar cells

    Science.gov (United States)

    Rohatgi, A.

    1986-01-01

    Various parameters that affect solar cell efficiency were discussed. It is not understood why solar cells produced from less expensive Czochralski (Cz) silicon are less efficient than cells fabricated from more expensive float-zone (Fz) silicon. Performance characteristics were presented for recently produced, high-efficient solar cells fabricated by Westinghouse Electric Corp., Spire Corp., University of New South Wales, and Stanford University.

  3. Control of non-conventional synchronous motors

    CERN Document Server

    Louis, Jean-Paul

    2013-01-01

    Classical synchronous motors are the most effective device to drive industrial production systems and robots with precision and rapidity. However, numerous applications require efficient controls in non-conventional situations. Firstly, this is the case with synchronous motors supplied by thyristor line-commutated inverters, or with synchronous motors with faults on one or several phases. Secondly, many drive systems use non-conventional motors such as polyphase (more than three phases) synchronous motors, synchronous motors with double excitation, permanent magnet linear synchronous motors,

  4. SENSITIVE ERROR ANALYSIS OF CHAOS SYNCHRONIZATION

    Institute of Scientific and Technical Information of China (English)

    HUANG XIAN-GAO; XU JIAN-XUE; HUANG WEI; L(U) ZE-JUN

    2001-01-01

    We study the synchronizing sensitive errors of chaotic systems for adding other signals to the synchronizing signal.Based on the model of the Henon map masking, we examine the cause of the sensitive errors of chaos synchronization.The modulation ratio and the mean square error are defined to measure the synchronizing sensitive errors by quality.Numerical simulation results of the synchronizing sensitive errors are given for masking direct current, sinusoidal and speech signals, separately. Finally, we give the mean square error curves of chaos synchronizing sensitivity and threedimensional phase plots of the drive system and the response system for masking the three kinds of signals.

  5. High-Efficiency Solar Cells on Low-Cost Substrates

    Science.gov (United States)

    Daiello, R. V.; Robinson, P. H.

    1982-01-01

    High-efficiency solar cells made in thin epitaxial films grown on low-cost commercial silicon substrates. Cost of cells is much less than if high-quality single-crystal silicon were used for substrates and performance of cells is almost as good.

  6. Forced synchronization of quasiperiodic oscillations

    Science.gov (United States)

    Stankevich, N. V.; Kurths, J.; Kuznetsov, A. P.

    2015-01-01

    A model of a generator of quasiperiodic oscillations forced by a periodic pulse sequence is studied. We analyze synchronization when the autonomous generator demonstrates periodic, quasiperiodic, respective weakly chaotic oscillations. For the forced quasiperiodic oscillations a picture of synchronization, consisting of small-scale and large-scale structures was uncovered. It even includes the existence of stable the three-frequency tori. For the regime of weak chaos a partial destruction of this features and of the regime of three-frequency tori are found.

  7. Synchronization and information transmission in spatio-temporal networks of deformable units

    Science.gov (United States)

    Moukam Kakmeni, F. M.; Baptista, M. S.

    2008-06-01

    We study the relationship between synchronization and the rate with which information is exchanged between nodes in a spatio-temporal network that describes the dynamics of classical particles under a substrate Remoissenet-Peyrard potential. We also show how phase and complete synchronization can be detected in this network. The difficulty in detecting phase synchronization in such a network appears due to the highly non-coherent character of the particle dynamics which unables a proper definition of the phase dynamics. The difficulty in detecting complete synchronization appears due to the spatio character of the potential which results in an asymptotic state highly dependent on the initial state.

  8. Synchronization and information transmission in spatio-temporal networks of deformable units

    Indian Academy of Sciences (India)

    F M Moukam Kakmeni; M S Baptista

    2008-06-01

    We study the relationship between synchronization and the rate with which information is exchanged between nodes in a spatio-temporal network that describes the dynamics of classical particles under a substrate Remoissenet-Peyrard potential. We also show how phase and complete synchronization can be detected in this network. The difficulty in detecting phase synchronization in such a network appears due to the highly non-coherent character of the particle dynamics which unables a proper definition of the phase dynamics. The di±culty in detecting complete synchronization appears due to the spatio character of the potential which results in an asymptotic state highly dependent on the initial state.

  9. Highly sensitive SERS analysis of the cyclic Arg-Gly-Asp peptide ligands of cells using nanogap antennas.

    Science.gov (United States)

    Portela, Alejandro; Yano, Taka-Aki; Santschi, Christian; Martin, Olivier J F; Tabata, Hitoshi; Hara, Masahiko

    2017-02-01

    The cyclic RGD (cRGD) peptide ligands of cells have become widely used for treating several cancers. We report a highly sensitive analysis of c(RGDfC) using surface enhanced Raman spectroscopy (SERS) using single dimer nanogap antennas in aqueous environment. Good agreement between characteristic peaks of the SERS and the Raman spectra of bulk c(RGDfC) with its peptide's constituents were observed. The exhibited blinking of the SERS spectra and synchronization of intensity fluctuations, suggest that the SERS spectra acquired from single dimer nanogap antennas was dominated by the spectrum of single to a few molecules. SERS spectra of c(RGDfC) could be used to detect at the nanoscale, the cells' transmembrane proteins binding to its ligand. SERS of cyclic RGD on nanogap antenna.

  10. Innovative High Temperature Fuel Cell systems

    NARCIS (Netherlands)

    Au, Siu Fai

    2003-01-01

    The world's energy consumption is growing extremely rapidly. Fuel cell systems are of interest by researchers and industry as the more efficient alternative to conventional thermal systems for power generation. The principle of fuel cell conversion does not involve thermal combustion and hence in th

  11. Innovative High Temperature Fuel Cell systems

    NARCIS (Netherlands)

    Au, Siu Fai

    2003-01-01

    The world's energy consumption is growing extremely rapidly. Fuel cell systems are of interest by researchers and industry as the more efficient alternative to conventional thermal systems for power generation. The principle of fuel cell conversion does not involve thermal combustion and hence in th

  12. Scientometric analysis of synchronous references in the Physics Nobel lectures, 1981-1985 : a pilot study

    OpenAIRE

    Upadhye, Rekha P.; Kalyane, V. L.; Vijai Kumar; Prakasan, E. R.

    2003-01-01

    Scientometric analysis of synchronous references in the nine Physics Nobel lectures by Nicolaas Bloembergen (1981), Arthur L. Schawlow (1981), Kai M. Siegbahn (1981), Kenneth G. Wilson (1982), Subrahmanyan Chandrasekhar (1983), William A. Fowler (1983), Carlo Rubbia (1984), Simon van der Meer (1984), and Klaus von Klitzing (1985) indicated high variations: No. of Synchronous References ranged from 24 (Meer) to 283 (Siegbahn); Synchronous Self-References ranged from 5 (Rubbia) to 88 (Siegbahn)...

  13. Dynamics and Synchronization of Semiconductor Lasers for Chaotic Optical Communications

    Science.gov (United States)

    Liu, Jia-Ming; Chen, How-Foo; Tang, Shuo

    The objective of this chapter is to provide a complete picture of the nonlinear dynamics and chaos synchronization of single-mode semiconductor lasers for chaotic optical communications. Basic concepts and theoretical framework are reviewed. Experimental results are presented to demonstrate the fundamental concepts. Numerical computations are employed for mapping the dynamical states and for illustrating certain detailed characteristics of the chaotic states. Three different semiconductor laser systems, namely, the optical injection system, the optical feedback system, and the optoelectronic feedback system, that are of most interest for high-bit-rate chaotic optical communications are considered. The optical injection system is a nonautonomous system that follows a period-doubling route to chaos. The optical feedback system is a phase-sensitive delayed-feedback autonomous system for which all three known routes, namely, period-doubling, quasiperiodicity, and intermittency, to chaos can be found. The optical feedback system is a phase-insensitive delayed-feedback autonomous system that follows a quasiperiodicity route to chaotic pulsing. Identical synchronization in unidirectionally coupled configurations is the focus of discussions for chaotic communications. For optical injection and optical feedback systems, the frequency, phase, and amplitude of the optical fields of both transmitter and receiver lasers are all locked in synchronism when complete synchronization is accomplished. For the optoelectronic feedback system, chaos synchronization involves neither the locking of the optical frequency nor the synchronization of the optical phase. For both optical feedback and optoelectronic feedback systems, where the transmitter is configured with a delayed feedback loop, anticipated and retarded synchronization can be observed as the difference between the feedback delay time and the propagation time from the transmitter laser to the receiver laser is varied. For a

  14. Cluster synchronization modes in an ensemble of coupled chaotic oscillators

    OpenAIRE

    Belykh, Vladimir N.; Belykh, Igor V.; Mosekilde, Erik

    2001-01-01

    Considering systems of diffusively coupled identical chaotic oscillators, an effective method to determine the possible states of cluster synchronization and ensure their stability is presented. The method, which may find applications in communication engineering and other fields of science and technology, is illustrated through concrete examples of coupled biological cell models.

  15. Synchronization Phenomena in an Array of Population Dynamic Systems

    DEFF Research Database (Denmark)

    Postnov, D.E.; Balanov, A.G.; Mosekilde, Erik

    1998-01-01

    The paper applies continuation methods to examine synchronization phenomena that can arise in a cascaded system of population dynamic models. The individual model describes a bacterial population interacting with a population of viruses that attack the cells. Coupling between the subsystems...

  16. Cluster synchronization modes in an ensemble of coupled chaotic oscillators

    DEFF Research Database (Denmark)

    Belykh, Vladimir N.; Belykh, Igor V.; Mosekilde, Erik

    2001-01-01

    Considering systems of diffusively coupled identical chaotic oscillators, an effective method to determine the possible states of cluster synchronization and ensure their stability is presented. The method, which may find applications in communication engineering and other fields of science and t...... and technology, is illustrated through concrete examples of coupled biological cell models....

  17. A Synchronization Scheme for Single-Phase Grid-Tied Inverters Under Harmonic Distortion and Grid Disturbances

    DEFF Research Database (Denmark)

    Hadjidemetriou, Lenos; Kyriakides, Elias; Yang, Yongheng

    2016-01-01

    Synchronization is a crucial aspect in grid-tied systems, including single-phase photovoltaic inverters, and it can affect the overall performance of the system. Among prior-art synchronization schemes, the Multi Harmonic Decoupling Cell Phase-Locked Loop (MHDC-PLL) presents a fast response under...... grid disturbances and high accuracy under harmonic distortions. However, major drawbacks of the MHDC-PLL include increased complexity and inaccurate response under non-nominal frequencies, which may occur in practical applications. Thus, this paper proposes strategies to address these issues. At first......, a novel re-formulation of an equivalent decoupling cell is proposed for reducing the implementation complexity, and then a frequency adaptive quadrature signal generator for the MHDC-PLL is proposed to enable an accurate response even under non-nominal frequencies. Simulation and experimental results...

  18. Synchronous mucinous adenocarcinoma of the recto sigmoid revealed by and seeding an anal fistula. (A case report and review of the literature).

    Science.gov (United States)

    Spiridakis, Konstadinos G; Sfakianakis, Elefterios E; Flamourakis, Manthos E; Intzepogazoglou, Dimitra S; Tsagataki, Eleni S; Ximeris, Nikolaos E; Rachmanis, Efstathios K; Gionis, Ioannis G; Kostakis, Giorgos E; Christodoulakis, Manousos S

    2017-01-01

    There are few cases of synchronous rectal adenocarcinoma revealed by an anal fistula. The diagnosis of synchronous mucinous adenocarcinoma of the recto sigmoid and anal canal remains difficult. The chronic anal fistula can be mistaken as the common manifestation of a benign perianal abscess or fistula. We present a rare case of a Greek Caucasian 79year old male patient with anal fistula and a recurrent perianal abscess who subsequently was found to have developed synchronous rectosigmoid and perianal mucinous adenocarcinoma on biopsy. The histological exam revealed mucinous adenocarcinoma in two sites, representing two tumors, cells were immunopositive for cytokeratin 20 and negative in cytokeratin 7. The patient underwent "laparoscopic extralevator abdominoperineal excision " with both lesions being resected. There is no recurrence after four years of follow up. This case highlights the importance of high suspicion, further investigation and the need of biopsy in all anal fistulae. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Memory formation by neuronal synchronization.

    NARCIS (Netherlands)

    Axmacher, N.; Mormann, F.; Fernandez, G.; Elger, C.E.; Fell, J.

    2006-01-01

    Cognitive functions not only depend on the localization of neural activity, but also on the precise temporal pattern of activity in neural assemblies. Synchronization of action potential discharges provides a link between large-scale EEG recordings and cellular plasticity mechanisms. Here, we focus

  20. Process algebra for synchronous communication

    NARCIS (Netherlands)

    Bergstra, J.A.; Klop, J.W.

    1984-01-01

    Within the context of an algebraic theory of processes, an equational specification of process cooperation is provided. Four cases are considered: free merge or interleaving, merging with communication, merging with mutual exclusion of tight regions, and synchronous process cooperation. The rewrite

  1. Epidemic Synchronization in Robotic Swarms

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Nielsen, Jens Frederik Dalsgaard; Ngo, Trung Dung

    2009-01-01

    Clock synchronization in swarms of networked mobile robots is studied in a probabilistic, epidemic framework. In this setting communication and synchonization is considered to be a randomized process, taking place at unplanned instants of geographical rendezvous between robots. In combination wit...

  2. Learning through synchronous electronic discussion

    NARCIS (Netherlands)

    Kanselaar, G.; Veerman, A.L.; Andriessen, J.E.B.

    2000-01-01

    This article reports a study examining university student pairs carrying out an electronic discussion task in a synchronous computer mediated communication (CMC) system (NetMeeting). The purpose of the assignment was to raise students' awareness concerning conceptions that characterise effective ped

  3. Synchronizing Web Documents with Style

    NARCIS (Netherlands)

    R.L. Guimarães (Rodrigo); D.C.A. Bulterman (Dick); P.S. Cesar Garcia (Pablo Santiago); A.J. Jansen (Jack)

    2014-01-01

    htmlabstractIn this paper we report on our efforts to define a set of document extensions to Cascading Style Sheets (CSS) that allow for structured timing and synchronization of elements within a Web page. Our work considers the scenario in which the temporal structure can be decoupled from the

  4. Sports Medicine Meets Synchronized Swimming.

    Science.gov (United States)

    Wenz, Betty J.; And Others

    This collection of articles contains information about synchronized swimming. Topics covered include general physiology and cardiovascular conditioning, flexibility exercises, body composition, strength training, nutrition, coach-athlete relationships, coping with competition stress and performance anxiety, and eye care. Chapters are included on…

  5. Fermi Timing and Synchronization System

    Energy Technology Data Exchange (ETDEWEB)

    Wilcox, R.; Staples, J.; Doolittle, L.; Byrd, J.; Ratti, A.; Kaertner, F.X.; Kim, J.; Chen, J.; Ilday, F.O.; Ludwig, F.; Winter, A.; Ferianis, M.; Danailov, M.; D' Auria, G.

    2006-07-19

    The Fermi FEL will depend critically on precise timing of its RF, laser and diagnostic subsystems. The timing subsystem to coordinate these functions will need to reliably maintain sub-100fs synchronicity between distant points up to 300m apart in the Fermi facility. The technology to do this is not commercially available, and has not been experimentally demonstrated in a working facility. Therefore, new technology must be developed to meet these needs. Two approaches have been researched by different groups working with the Fermi staff. At MIT, a pulse transmission scheme has been developed for synchronization of RF and laser devices. And at LBL, a CW transmission scheme has been developed for RF and laser synchronization. These respective schemes have advantages and disadvantages that will become better understood in coming years. This document presents the work done by both teams, and suggests a possible system design which integrates them both. The integrated system design provides an example of how choices can be made between the different approaches without significantly changing the basic infrastructure of the system. Overall system issues common to any synchronization scheme are also discussed.

  6. Synchronization in Triangled Complex Networks

    Institute of Scientific and Technical Information of China (English)

    LU Xin-Biao; LI Xiang; WANG Xiao-Fan

    2006-01-01

    Using a tunable clustering coefficient model withoutchanging the degree distribution, we investigate the effect of clustering coefficient on synchronization of networks with both unweighted and weighted couplings. For several typical categories of complex networks, the more triangles are in the networks, the worse the synchronizability of the networks is.

  7. Synchronizing Web Documents with Style

    NARCIS (Netherlands)

    Guimarães, R.L.; Bulterman, D.C.A.; Cesar Garcia, P.S.; Jansen, A.J.

    2014-01-01

    In this paper we report on our efforts to define a set of document extensions to Cascading Style Sheets (CSS) that allow for structured timing and synchronization of elements within a Web page. Our work considers the scenario in which the temporal structure can be decoupled from the content of the W

  8. Synchronized whistlers recorded at Varanasi

    Indian Academy of Sciences (India)

    Rajesh Singh; Ashok K Singh; R P Singh

    2003-06-01

    Some interesting events of synchronized whistlers recorded at low latitude station Varanasi during magnetic storm period of the year 1977 are presented. The dynamic spectrum analysis shows that the component whistlers are Eckersley whistlers having dispersion 10 s1/2 and 30 s1/2. An attempt has been made to explain the dynamic spectra using lightning discharge generated from magnetospheric sources.

  9. Modeling Distributed Multimedia Synchronization with DSPN

    Institute of Scientific and Technical Information of China (English)

    宋军; 顾冠群

    1998-01-01

    Multimedia synchronization is the essential technology for the integration of multimedia in distributed multimedia systems.The multimedia synchronization model has been recognized by many researchers as a premise of the implementation of multimedia synchronization.In distributed multimedia systems,the characteristic of multimedia synchronization is dynamic,and the key medium has the priority in multimedia synchronization.The previously proposed multimedia synchronization models cannot meet these requirements.So a new multimedia dynamic synchronization model-DSPN,based on the timed Petri-net has been designed in this paper.This model can not only let the distributed multimedia system keep multimedia synchronization in a more precise and effective manner according to the runtime situation of the system,but also allow the user to interact with the presentation of multimedia.

  10. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du

    2015-01-01

    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  11. Clock Synchronization and Navigation in the Vicinity of the Earth

    CERN Document Server

    Bahder, T B

    2004-01-01

    Clock synchronization is the backbone of applications such as high-accuracy satellite navigation, geolocation, space-based interferometry, and cryptographic communication systems. The high accuracy of synchronization needed over satellite-to-ground and satellite-to-satellite distances requires the use of general relativistic concepts. The role of geometrical optics and antenna phase center approximations are discussed in high accuracy work. The clock synchronization problem is explored from a general relativistic point of view, with emphasis on the local measurement process and the use of the tetrad formalism as the correct model of relativistic measurements. The treatment makes use of J. L. Synge's world function of space-time as a basic coordinate independent geometric concept. A metric is used for space-time in the vicinity of the Earth, where coordinate time is proper time on the geoid. The problem of satellite clock syntonization is analyzed by numerically integrating the geodesic equations of motion for...

  12. The role of temporal prediction abilities in interpersonal sensorimotor synchronization.

    Science.gov (United States)

    Pecenka, Nadine; Keller, Peter E

    2011-06-01

    Musical ensemble performance is a form of joint action that requires highly precise yet flexible interpersonal action coordination. To maintain synchrony during expressive passages that contain tempo variations, musicians presumably anticipate the sounds that will be produced by their co-performers. Our previous studies revealed that individuals differ in their ability to predict upcoming event timing when finger tapping in synchrony with tempo-changing pacing signals (i.e., the degree to which inter-tap intervals match vs. lag behind inter-onset intervals in the pacing signal varies between individuals). The current study examines the influence of these individual differences on synchronization performance in a dyadic tapping task. In addition, the stability of individual prediction tendencies across time is tested. Individuals with high or low prediction tendencies were invited to participate in two experimental sessions. In both sessions, participants were asked (1) to tap alone with a tempo-changing pacing signal and (2) to tap synchronously in dyads comprising individuals with similar or different prediction tendencies. Results indicated that individual differences in prediction tendencies were stable over several months and played a significant role in dyadic synchronization. Dyads composed of two high-predicting individuals tapped with higher accuracy and less variability than low-predicting dyads, while mixed dyads were intermediate. Prediction tendencies explained variance in dyadic synchronization performance over and above individual synchronization ability. These findings suggest that individual differences in temporal prediction ability may potentially mediate the interaction of cognitive, motor, and social processes underlying musical joint action.

  13. High frequency induction cladding microstructure and properties of the boiler pipe based on synchronous powder feeding method%基于同步送粉法的锅炉管高频感应熔覆组织性能

    Institute of Scientific and Technical Information of China (English)

    王云山; 胡鹏; 雷剑波; 岑虎; 顾振杰

    2015-01-01

    The NiCrSiB alloy coating was fabricated on the surface of boiler tube with 12Cr MoV structural alloy steel by high frequency induction cladding. The first kind of method is thermal spraying, the second is cold-preseting coating method when water glass was used for binder, the third is a synchronous powder feeding method. The Scanning Electron Microscope and Energy Dispersive Spectrometer were used to analyze microstructure and composition of the cladding layers. The hardness experiment was carried out. The cladding current was set to be 830 A. The power frequency was given at the level of 250 kHz. The results show that the cladding layer and the substrate obtained by the method of thermal spraying has obvious gap. Cladding layers had slag and its surface were roughness by the cold-preseting coating method. The surface of cladding layers were smooth by the way of synchronous powder feeding method. And the result that serrated white bright band between the cladding layer and the substrate shows transitional zone forms metallurgical bonding. The hardness of cladding layer is 310 HV, which is 2 times higher than that of substrate. This technology of high frequency induction cladding by the way of synchronous powder feeding method has more advantages such as environment protection, higher machining efficiency, higher smoothness of cylindrical surface, no slag inclusion, lower processing cost, than that by pre-coating methods.%采用高频感应熔覆技术,在12CrMoV合金结构钢材质的锅炉管表面进行了采用热喷涂、水玻璃作为黏结剂冷预置涂层、高频感应同步送粉器直接将合金粉末送于锅炉管表面3种工艺方法制备NiCrSiB耐磨合金涂层实验研究,用SEM和能谱仪分析了基体与熔覆层界面和熔覆层间的微观组织及成分,开展了硬度测试实验。结果表明:在熔覆电流为830 A、熔覆频率为250 kHz的条件下,热喷涂法得到的熔覆层与基体有明显的间隙;水玻璃

  14. microRNA miR-142-3p Inhibits Breast Cancer Cell Invasiveness by Synchronous Targeting of WASL, Integrin Alpha V, and Additional Cytoskeletal Elements.

    Directory of Open Access Journals (Sweden)

    Alexander Schwickert

    Full Text Available MicroRNAs (miRNAs, micro ribonucleic acids are pivotal post-transcriptional regulators of gene expression. These endogenous small non-coding RNAs play significant roles in tumorigenesis and tumor progression. miR-142-3p expression is dysregulated in several breast cancer subtypes. We aimed at investigating the role of miR-142-3p in breast cancer cell invasiveness. Supported by transcriptomic Affymetrix array analysis and confirmatory investigations at the mRNA and protein level, we demonstrate that overexpression of miR-142-3p in MDA-MB-231, MDA-MB-468 and MCF-7 breast cancer cells leads to downregulation of WASL (Wiskott-Aldrich syndrome-like, protein: N-WASP, Integrin-αV, RAC1, and CFL2, molecules implicated in cytoskeletal regulation and cell motility. ROCK2, IL6ST, KLF4, PGRMC2 and ADCY9 were identified as additional targets in a subset of cell lines. Decreased Matrigel invasiveness was associated with the miR-142-3p-induced expression changes. Confocal immunofluorescence microscopy, nanoscale atomic force microscopy and digital holographic microscopy revealed a change in cell morphology as well as a reduced cell volume and size. A more cortical actin distribution and a loss of membrane protrusions were observed in cells overexpressing miR-142-3p. Luciferase activation assays confirmed direct miR-142-3p-dependent regulation of the 3'-untranslated region of ITGAV and WASL. siRNA-mediated depletion of ITGAV and WASL resulted in a significant reduction of cellular invasiveness, highlighting the contribution of these factors to the miRNA-dependent invasion phenotype. While knockdown of WASL significantly reduced the number of membrane protrusions compared to controls, knockdown of ITGAV resulted in a decreased cell volume, indicating differential contributions of these factors to the miR-142-3p-induced phenotype. Our data identify WASL, ITGAV and several additional cytoskeleton-associated molecules as novel invasion-promoting targets of miR-142

  15. Expansion of Endothelial Progenitor Cells in High Density Dot Culture of Rat Bone Marrow Cells

    Science.gov (United States)

    Wang, Ling; Kretlow, James D.; Zhou, Guangdong; Cao, Yilin; Liu, Wei; Zhang, Wen Jie

    2014-01-01

    In vitro expansion of endothelial progenitor cells (EPCs) remains a challenge in stem cell research and its application. We hypothesize that high density culture is able to expand EPCs from bone marrow by mimicking cell-cell interactions of the bone marrow niche. To test the hypothesis, rat bone marrow cells were either cultured in high density (2×105 cells/cm2) by seeding total 9×105 cells into six high density dots or cultured in regular density (1.6×104 cells/cm2) with the same total number of cells. Flow cytometric analyses of the cells cultured for 15 days showed that high density cells exhibited smaller cell size and higher levels of marker expression related to EPCs when compared to regular density cultured cells. Functionally, these cells exhibited strong angiogenic potentials with better tubal formation in vitro and potent rescue of mouse ischemic limbs in vivo with their integration into neo-capillary structure. Global gene chip and ELISA analyses revealed up-regulated gene expression of adhesion molecules and enhanced protein release of pro-angiogenic growth factors in high density cultured cells. In summary, high density cell culture promotes expansion of bone marrow contained EPCs that are able to enhance tissue angiogenesis via paracrine growth factors and direct differentiation into endothelial cells. PMID:25254487

  16. Robust synchronization of chaotic systems via feedback

    Energy Technology Data Exchange (ETDEWEB)

    Femat, Ricardo [IPICYT, San Luis Potosi (Mexico). Dept. de Matematicas Aplicadas; Solis-Perales, Gualberto [Universidad de Guadalajara, Centro Univ. de Ciencias Exactas e Ingenierias (Mexico). Div. de Electronica y Computacion

    2008-07-01

    This volume includes the results derived during last ten years about both suppression and synchronization of chaotic -continuous time- systems. Along this time, the concept was to study how the intrinsic properties of dynamical systems can be exploited to suppress and to synchronize the chaotic behaviour and what synchronization phenomena can be found under feedback interconnection. A compilation of these findings is described in this book. This book shows a perspective on synchronization of chaotic systems. (orig.)

  17. Synchronization effect for uncertain quantum networks

    Science.gov (United States)

    Li, Wenlin; Gebremariam, Tesfay; Li, Chong; Song, Heshan

    2017-01-01

    We propose a novel technique for investigating the synchronization effect for uncertain networks with quantum chaotic behaviors in this paper. Through designing a special function to construct Lyapunov function of network and the adaptive laws of uncertain parameters, the synchronization between the uncertain network and the synchronization target can be realized, and the uncertain parameters in state equations of the network nodes are perfectly identified. All the theoretical results are verified by numerical simulations to demonstrate the effectiveness of the proposed synchronization technique.

  18. High Efficiency, Deployable Solar Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ultrathin, lightweight, flexible, and easily deployable solar cell (SC) capable of specific power greater than 1kW/kg are at an early stage of development for...

  19. First Case Report of a Sporadic Adrenocortical Carcinoma With Gastric Metastasis and a Synchronous Gastrointestinal Stromal Tumor of the Stomach.

    Science.gov (United States)

    Kovecsi, Attila; Jung, Ioan; Bara, Tivadar; Bara, Tivadar; Azamfirei, Leonard; Kovacs, Zsolt; Gurzu, Simona

    2015-09-01

    Adrenocortical carcinoma is a rare tumor with high aggresivity that can associate systemic metastases. A 71-year-old man was hospitalized for gastric cancer. The abdominal computed tomography also revealed a tumor above the right kidney. Total gastrectomy and right adrenalectomy were performed. The encapsulated tumor of the adrenal gland weighed 560 grams and presented diffuse tumor architecture under microscope, with capsular, sinusoidal, and vascular invasion. The large tumor cells had a polygonal shape, with slight basophilic, eosinophilic, or vacuolated cytoplasm, pleomorphic nuclei, and a high mitotic rate. In the stomach, the protruded tumor was covered by normal mucosa; under microscope, the tumor cells were observed only in the submucosal layer. In primary adrenal tumor and gastric metastasis the tumor cells were marked by vimentin, inhibin, synaptophysin, neuron-specific enolase, and calretinin. Based on these criteria, the diagnosis of adrenocortical carcinoma (ACC) with gastric metastasis and no lymph node metastases was established. A synchronous 10 × 10-mm-sized gastrointestinal stromal tumor (GIST) of the stomach, without mitoses, was also identified. So far, as we know, this is the 15th case of ever reported synchronous/metachronous sporadic ACCs; the ACC-related gastric metastases either synchronous ACC and GIST, has not been reported in the literature previously.

  20. Synchronization in complex clustered networks

    Institute of Scientific and Technical Information of China (English)

    HUANG Liang; LAI Ying-Cheng; Kwangho PARK; WANG Xingang; LAI Choy Heng; Robert A. GATENBY

    2007-01-01

    Synchronization in complex networks has been an active area of research in recent years. While much effort has been devoted to networks with the small-world and scale-free topology, structurally they are often assumed to have a single, densely connected component. Recently it has also become apparent that many networks in social, biological, and tech-nological systems are clustered, as characterized by a number (or a hierarchy) of sparsely linked clusters, each with dense and complex internal connections. Synchronization is funda-mental to the dynamics and functions of complex clustered networks, but this problem has just begun to be addressed. This paper reviews some progress in this direction by focus-ing on the interplay between the clustered topology and net-work synchronizability. In particular, there are two parame-ters characterizing a clustered network: the intra-cluster and the inter-cluster link density. Our goal is to clarify the roles of these parameters in shaping network synchronizability. By using theoretical analysis and direct numerical simulations of oscillator networks, it is demonstrated that clustered net-works with random inter-cluster links are more synchroniz-able, and synchronization can be optimized when inter-cluster and intra-cluster links match. The latter result has one coun-terintuitive implication: more links, if placed improperly, can actually lead to destruction of synchronization, even though such links tend to decrease the average network distance. It is hoped that this review will help attract attention to the fun-damental problem of clustered structures/synchronization in network science.