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Sample records for cascades controlling metabolism

  1. Recent insights into the role of hypothalamic AMPK signaling cascade upon metabolic control

    Directory of Open Access Journals (Sweden)

    Marc eClaret

    2012-12-01

    Full Text Available In 2004, two seminal papers focused on the role of AMP-activated protein kinase (AMPK in the hypothalamus opened new avenues of research in the field of the central regulation of energy homeostasis. Over the following 8 years, hundreds of studies have firmly established hypothalamic AMPK as a key sensor and integrator of hormonal and nutritional signals with neurochemical and neurophysiological responses to regulate whole-body energy balance. In this review article we aim to discuss the most recent findings in this particular area of research, highlighting the function of hypothalamic AMPK in appetite, thermogenesis and peripheral glucose metabolism. The diversity of mechanisms by which hypothalamic AMPK regulates energy homeostasis illustrates the importance of this evolutionary-conserved energy signaling cascade in the control of this complex and fundamental biological process.

  2. Control of Cascaded Multilevel Inverters

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    Abstract-A new type of multilevel inverter is introduced which is created by cascading two three-phase three-level inverters using the load connection, but requires only one DC voltage source. This new inverter can operateas a seven-level inverter and naturally splits the power conversion into a higher-voltage lower-frequency inverter and a lower-voltage higher-fre-quency inverter. This type of system presents particular advantages to Naval ship propulsion systems which rely on high power quality, survivable drives. New control methods are described involving both joint and separate control of the individual three-level inverters. Simulation resuits demonstrate the effectiveness of both controls. A laboratory set-up at the Naval Surface Warfare Center power electronics laboratory was used to validate the proposed joint-inverter control. Due to the effect of compounding levels in the cascaded inverter, a high number of levels are available resulting in a voltage THD of 9% (without filtering). Index Terms-Cascaded inverter, multilevel inverter, three-level inverter.

  3. Controllability of nonlinear degenerate parabolic cascade systems

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    Mamadou Birba

    2016-08-01

    Full Text Available This article studies of null controllability property of nonlinear coupled one dimensional degenerate parabolic equations. These equations form a cascade system, that is, the solution of the first equation acts as a control in the second equation and the control function acts only directly on the first equation. We prove positive null controllability results when the control and a coupling set have nonempty intersection.

  4. Signalling cascades integrating light-enhanced nitrate metabolism.

    Science.gov (United States)

    Lillo, Cathrine

    2008-10-01

    In higher plants, light is crucial for regulation of nitrate uptake, translocation and assimilation into organic compounds. Part of this metabolism is tightly coupled to photosynthesis because the enzymes involved, nitrite reductase and glutamate synthase, are localized to the chloroplasts and receive reducing power from photosynthetic electron transport. However, important enzymes in nitrate acquisition and reduction are localized to cellular compartments other than chloroplasts and are also up-regulated by light, i.e. transporters in cell and organellar membranes and nitrate reductase in the cytosol. This review describes the different light-dependent signalling cascades regulating nitrate metabolism at the transcriptional as well as post-transcriptional level, and how reactions in different compartments of the cell are co-ordinated. Essential players in this network are phytochrome and HY5 (long hypocotyls 5)/HYH (HY5 homologue)-dependent signalling pathways, the energy-related AMPK (AMP-activated protein kinase) protein kinase homologue SNRK1 (sucrose non-fermenting kinase 1-related kinase), chloroplastic thioredoxins and the prokaryotically originated PII protein. A complex light-dependent network of regulation emerges, which appears to be necessary for optimal nitrogen assimilation and for avoiding the accumulation of toxic intermediates and side products, such as nitrite and reactive oxygen compounds.

  5. Fuzzy cascade control based on control's history for superheated temperature

    Institute of Scientific and Technical Information of China (English)

    WANG Guangjun; LI Gang; SHEN Shuguang

    2007-01-01

    To address the characteristics of the large delay and uncertainty of superheated temperature,a new cascade control system is presented based on control's history.Based on the analysis of the control objects' dynamic characteristics,historical control information (substituting for the deviation change rate) is used as the basis for decision-making of the fuzzy control.Therefore,the changing trend of the controlled variable can be accurately reflected.Furthermore,a proportional component is introduced,the advantages of PID and fuzzy controllers are integrated,and the structure weaknesses of conventional fuzzy controllers are overcome.Simulation shows that this control method can effectively reduce the adverse impact of the delay on control effects and,therefore,exhibit strong adaptability by comparing the superheated temperature control system by this controller with PID and conventional fuzzy controllers.

  6. Impedance Coordinative Control for Cascaded Converter in Bidirectional Application

    DEFF Research Database (Denmark)

    Tian, Yanjun; Deng, Fujin; Chen, Zhe;

    2015-01-01

    difference between forward and reversed power flow. This paper addresses the analysis with the topology of cascaded dual-active-bridge converter (DAB) with inverter, and the proposed control method can also be implemented in unidirectional applications and other general cascaded converter system...

  7. Cascade Control of Magnetic Levitation with Sliding Modes

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    Eroğlu Yakup

    2016-01-01

    Full Text Available The effectiveness and applicability of magnetic levitation systems need precise feedback control designs. A cascade control approach consisting of sliding mode control plus sliding mode control (SMC plus SMC is designed to solve position control problem and to provide a high control performance and robustness to the magnetic levitation plant. It is shown that the SMC plus SMC cascade controller is able to eliminate the effects of the inductance related uncertainties of the electromagnetic coil of the plant and achieve a robust and precise position control. Experimental and numerical results are provided to validate the effectiveness and feasibility of the method.

  8. Cascade adaptive control of uncertain unified chaotic systems

    Institute of Scientific and Technical Information of China (English)

    Wei Wei; Li Dong-Hai; Wang Jing

    2011-01-01

    The chaos control of uncertain unified chaotic systems is considered. Cascade adaptive control approach with only one control input is presented to stabilize states of the uncertain unified chaotic system at the zero equilibrium point.Since an adaptive controller based on dynamic compensation mechanism is employed, the exact model of the unified chaotic system is not necessarily required.By choosing appropriate controller parameters, chaotic phenomenon can be suppressed and the response speed is tunable. Sufficient condition for the asymptotic stability of the approach is derived. Numerical simulation results confirm that the cascade adaptive control approach with only one control signal is valid in chaos control of uncertain unified chaotic systems.

  9. PULSE MODULATION POWER AMPLIFIER WITH ENHANCED CASCADE CONTROL METHOD

    DEFF Research Database (Denmark)

    1998-01-01

    A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by havi...... and feedback path A to determine stable self-oscillating conditions. An implemented 250W example MECC digital power amplifier has proven superior performance in terms of audio performance (0.005 % distortion, 115 dB dynamic range) and efficiency (92 %).......A digital switching power amplifier with Multivariable Enhanced Cascade Controlled (MECC) includes a modulator, a switching power stage and a low pass filter. In the first preferred embodiment an enhanced cascade control structure local to the switching power stage is added, characterised by having...

  10. Improving performance using cascade control and a Smith predictor.

    Science.gov (United States)

    Kaya, I

    2001-01-01

    Many investigations have been done on tuning proportional-integral-derivative (PID) controllers in single-input single-output (SISO) systems. However, only a few investigations have been carried out on tuning PID controllers in cascade control systems. In this paper, a new approach, namely the use of a Smith predictor in the outer loop of a cascade control system, is investigated. The method can be used in temperature control problems where the secondary part of the process (the inner loop) may have a negligible delay while the primary loop (the outer loop) has a time-delay. Two different approaches, including an autotuning method, to find the controller parameters are proposed. It is shown by some examples that the proposed structure as expected can provide better performance than conventional cascade control, a Smith predictor scheme or single feedback control system.

  11. Tracking Control for Switched Cascade Nonlinear Systems

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    Xiaoxiao Dong

    2015-01-01

    Full Text Available The issue of H∞ output tracking for switched cascade nonlinear systems is discussed in this paper, where not all the linear parts of subsystems are stabilizable. The conditions of the solvability for the issue are given by virtue of the structural characteristics of the systems and the average dwell time method, in which the total activation time for stabilizable subsystems is longer than that for the unstabilizable subsystems. At last, a simulation example is used to demonstrate the validity and advantages of the proposed approach.

  12. Performance validation of a cascade control system through

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    A. Lakshmi Sangeetha

    2016-11-01

    Full Text Available The work analyzes the performance characteristics of a cascade control system when interconnected with various network architectures, such as Internet, mobile and wireless networks. The cascade control system consists of level and flow as primary and secondary variables, respectively. The web-enabled monitoring and control are realized using three techniques namely remote client–server, ActiveX-data socket and web publishing tool. Mobile network is established by interfacing the control system with a GSM modem which enables the monitoring of process parameters through mobile phones. The cascade control system is also monitored wirelessly from remote locations with advent of an indigenous wireless sensor node. The performance analysis proved that wireless monitoring may be considered as an effective alternate technique to the Internet-based communication especially for shorter distances.

  13. Optimization Control of Bidirectional Cascaded DC-AC Converter Systems

    DEFF Research Database (Denmark)

    Tian, Yanjun

    in different power flow directions, a bidirectional impedance control method is also proposed to unify and improve the system stability. Control system type number is also analyzed in this thesis, then a symmetric proportional control method for the two stage cascaded converter is proposed to reduce the dc...

  14. Bearing-Only Formation Control for Cascade Multirobots

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    Qing Han

    2016-01-01

    Full Text Available A new formation control method is proposed, which is used to queue multirobots in a single-direction cascade structure. In the cascade formation, each robot is a follower for the previous robot and a leader for the next robot, and the robots in the middle act as both leader and follower. The follower robot can only observe the bearing information of the leader robot. The observability of the cascade leader-follower formation is studied, which shows that the bearing-only observation meets the observability conditions required for the nonlinear system. Based on the bearing-only observations, the unscented Kalman filter (UKF is employed for the state estimation of the leader and the follower robots at all levels, which enables the real-time movement control of the follower robots via the input-output feedback control. Simulation results demonstrate that the proposed approach can efficiently control the formation of multirobots as desired.

  15. Null controllability of a cascade system of Schrodinger equations

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    Marcos Lopez-Garcia

    2016-03-01

    Full Text Available This article presents a control problem for a cascade system of two linear N-dimensional Schrodinger equations. We address the problem of null controllability by means of a control supported in a region not satisfying the classical geometrical control condition. The proof is based on the application of a Carleman estimate with degenerate weights to each one of the equations and a careful analysis of the system in order to prove null controllability with only one control force.

  16. Laser-Pulse-Shape Control of Seeded QED Cascades

    CERN Document Server

    Tamburini, Matteo; Keitel, Christoph H

    2015-01-01

    The emergence of electron-positron cascades via ultrastrong electromagnetic fields constitutes a prominent manifestation of the complex interplay between strong-field QED processes and multiparticle dynamics. Here the onset and development of electron-positron cascades are investigated in the head-on collision of two realistic tightly focused ultraintense optical laser pulses in a tenuous gas. As a consequence of the large ponderomotive forces expelling all electrons of the gas from the focal volume, we demonstrate that the onset of QED cascades may be prevented even at intensities around $10^{26}\\;\\text{W/cm$^2$}$ by focusing the laser energy almost down to the diffraction limit. Alternatively, a well controlled development of a QED cascade may be facilitated at laser intensities below $10^{24}\\;\\text{W/cm$^2$}$ per beam by enlarged focal areas and a rapid rise of the pulse or at total powers near $20\\;\\text{PW}$ by employing suitable high-$Z$ gases.

  17. Neuroendocrine control of metabolism.

    Science.gov (United States)

    Kuliczkowska-Plaksej, J; Milewicz, A; Jakubowska, J

    2012-03-01

    Metabolism is controlled through homeostatic system consisting of central centers, gut hormones, hormones from adipose tissue and the other hormonal axes. This cooperation is based on cross-talk between central and peripheral signals. Among them the hypothalamus plays a crucial role, with interconnected nuclei forming neuronal circuits. Other regions in the brain, such as the brain stem, the endocannabinoid system, the vagal afferents, are also involved in energy balance. The second component is peripheral source of signals--the gastrointestinal tract hormones. Additionally, adipokines from adipose tissue, thyrotropic, gonadotropic and somatotropic axes play a role in energy homeostasis. Knowledge about all components of this neuroendocrine circuit will be helpful in developing novel therapeutic approaches against the metabolic syndrome and its components.

  18. Cascaded process model based control: packed absorption column application.

    Science.gov (United States)

    Govindarajan, Anand; Jayaraman, Suresh Kumar; Sethuraman, Vijayalakshmi; Raul, Pramod R; Rhinehart, R Russell

    2014-03-01

    Nonlinear, adaptive, process-model based control is demonstrated in a cascaded single-input-single-output mode for pressure drop control in a pilot-scale packed absorption column. The process is shown to be nonlinear. Control is demonstrated in both servo and regulatory modes, for no wind-up in a constrained situation, and for bumpless transfer. Model adaptation is demonstrated and shown to provide process insight. The application procedure is revealed as a design guide to aid others in implementing process-model based control.

  19. Analysis and control design of two cascaded boost converter

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    Moutabir A.

    2014-01-01

    Full Text Available This work aims to study a cascade of two BOOST converters. First, a non- linear model of the whole controlled system is developed. Then, a robust non-linear controller of currents is synthesized using a backstepping design technique. A formal analysis based on Lyapunov stability and average theory is developed to describe the control currents loops performances. A classical PI controller is used for the voltages loops. The study of the stability of the system will also be discussed. Simulated results are displayed to validate the feasibility and the effectiveness of the proposed strategy.

  20. Synchronization analysis on cascaded multilevel converters with distributed control

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Cascaded multilevel converters built with integrated modules have many advantages such as increased power density,flexible distributed control, multi-functionality, increased reliability and short design cycles. However, the system performance will be affected due to the synchronization errors among each integrated modules. This paper analyzes the impact of the three kinds of synchronization errors on the whole system performance, as well as detailed synchronization implementation. Some valuable conclusions are derived from the theoretical analysis, simulations and experimental results.

  1. Study on Control Strategies for the Multilevel Cascaded Converters

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    Lin Xu

    2013-11-01

    Full Text Available The multilevel cascaded converters are extensively applied for high-voltage and high-power applications, which are considered as the most favorable topologies for the high power ac-drives and the high-voltage DC transmission (HVDC systems using the voltage source converters (VSCs. This paper presents the dc capacitor balancing and effective current regulation methodologies for the multilevel cascaded converters. The dc-link voltage balancing and capacitor energy evolving mechanism of the MMCC is analyzed, and an effective control scheme is devised by utilizing two dc capacitor voltage control loops, including the total capacitor voltage controller (TCVC, the capacitor voltage balancing controller (CVBC. The predictive current controller is proposed to enhance the tracking accuracy of current control loop. The proportional-resonant controller (PRC is used as circulating current damping controller of the modular multilevel converter, which is found to be highly effective to minimize the circulating current. The Electromagnetic Transient Program (EMTP is utilized for digital simulation of the single-phase five-level modular multilevel converter. The effectiveness of the control scheme is validated by the simulation results.

  2. Cascade Control Solution for Traction Motor for Hybrid Electric Vehicles

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    Zsuzsa Preitl

    2007-10-01

    Full Text Available In this paper a hybrid electric vehicle is considered, which contains both aninternal combustion engine and an electric motor (EM. Without focusing on the othercomponents of the vehicle, the EM is treated in detail, both regarding modelling aspectsand control solutions.After a brief modelling of the plant, two cascade speed control solutions are presented: firsta classical PI+PI cascade control solution is presented. The control systems related totraction electric motors (used in vehicle traction must be able to cope with differentrequests, such as variation of the reference signal, load disturbances which depend on thetransport conditions and parametric disturbances regarding changes in the total mass ofthe vehicle. For this purpose, in the design of the speed controller (external loop a specificmethodology based on extension of the symmetrical optimum method is presented. Thecontrollers are developed using the Modulus–Optimum method for the inner loop, and theExtended Symmetrical Optimum Method, corrected based on the 2p-SO-method, for theouter loop (for a more efficient disturbance rejection.In order to force the behaviour of the system regarding the reference input, a correctionterm is introduced as a non-homogenous structured PI controller solution.Simulations were performed using numerical values taken from a real applicationconsisting in a hybrid vehicle prototype, showing satisfactory behaviour.

  3. Velocity and Motion Control of a Self-balancing Vehicle based on a Cascade Control Strategy

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    Miguel Velazquez

    2016-06-01

    Full Text Available This paper presents balancing, velocity and motion control of a self-balancing vehicle. A cascade controller is implemented for both balancing control and angular velocity control. This controller is tested in simulations using a proposed mathematical model of the system. Motion control is achieved based on the kinematics of the robot. Control hardware is designed and integrated to implement the proposed controllers. Pitch is kept under 1° from the equilibrium position with no external disturbances. The linear cascade control is able to handle slight changes in the system dynamics, such as in the centre of mass and the slope on an inclined surface.

  4. Velocity and Motion Control of a Self-Balancing Vehicle Based on a Cascade Control Strategy

    Directory of Open Access Journals (Sweden)

    Miguel Velazquez

    2016-06-01

    Full Text Available This paper presents balancing, velocity and motion control of a self-balancing vehicle. A cascade controller is implemented for both balancing control and angular velocity control. This controller is tested in simulations using a proposed mathematical model of the system. Motion control is achieved based on the kinematics of the robot. Control hardware is designed and integrated to implement the proposed controllers. Pitch is kept under 1° from the equilibrium position with no external disturbances. The linear cascade control is able to handle slight changes in the system dynamics, such as in the centre of mass and the slope on an inclined surface.

  5. Control Strategy for Cascaded Medium - High Voltage STATCOM

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    Libing Chen

    2013-12-01

    Full Text Available Control strategy is researched for cascaded medium high static synchronous compensator to provide synthetic compensation ability of reactive power, harmonics and asymmetric currents. Basing on selective harmonic compensation strategy, a reference current detection method utilizing the combination of synchronous reference frame transformation and discrete Fourier transformation is proposed. The tracking control of instruction current is implemented by multi-carrier pulse width modulation (PWM. In allusion to the multi-carrier PWM, the capacitor voltage balancing control at the dc side is realized by a type of software based on the energy balance principle of the inverter bridge. The proposed control strategy is convenient for engineering implementation given its low calculation burden and simplicity. The effectiveness of the proposed control strategy is proven by both simulation and experimental results.

  6. Cascaded adaptive control of ocean vehicles with significant actuator dynamics

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1994-04-01

    Full Text Available This paper presents a cascade adaptive control scheme for marine vehicles where the non-linear equations of motion include a model of the actuator dynamics. The adaptive controller does not require the parameters of the vehicle dynamics and the actuator time constants to be known a priori. Both the velocity and position tracking errors are shown to converge to zero by applying Barbalat's lemma. Global asymptotic stability is proven for the velocity scheme while the position/attitude controller is only proven to be convergent. Furthermore, all parameter estimates are shown to be bounded. Computer simulations of an ROV speed control system and an autopilot for automatic ship steering are used to illustrate the design methodology.

  7. Oxidative bioelectrocatalysis: From natural metabolic pathways to synthetic metabolons and minimal enzyme cascades.

    Science.gov (United States)

    Minteer, Shelley D

    2016-05-01

    Anodic bioelectrodes for biofuel cells are more complex than cathodic bioelectrodes for biofuel cells, because laccase and bilirubin oxidase can individually catalyze four electron reduction of oxygen to water, whereas most anodic enzymes only do a single two electron oxidation of a complex fuel (i.e. glucose oxidase oxidizing glucose to gluconolactone while generating 2 electrons of the total 24 electrons), so enzyme cascades are typically needed for complete oxidation of the fuel. This review article will discuss the lessons learned from natural metabolic pathways about multi-step oxidation and how those lessons have been applied to minimal or artificial enzyme cascades. This article is part of a Special Issue entitled Biodesign for Bioenergetics--the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

  8. Structural control of metabolic flux.

    Directory of Open Access Journals (Sweden)

    Max Sajitz-Hermstein

    Full Text Available Organisms have to continuously adapt to changing environmental conditions or undergo developmental transitions. To meet the accompanying change in metabolic demands, the molecular mechanisms of adaptation involve concerted interactions which ultimately induce a modification of the metabolic state, which is characterized by reaction fluxes and metabolite concentrations. These state transitions are the effect of simultaneously manipulating fluxes through several reactions. While metabolic control analysis has provided a powerful framework for elucidating the principles governing this orchestrated action to understand metabolic control, its applications are restricted by the limited availability of kinetic information. Here, we introduce structural metabolic control as a framework to examine individual reactions' potential to control metabolic functions, such as biomass production, based on structural modeling. The capability to carry out a metabolic function is determined using flux balance analysis (FBA. We examine structural metabolic control on the example of the central carbon metabolism of Escherichia coli by the recently introduced framework of functional centrality (FC. This framework is based on the Shapley value from cooperative game theory and FBA, and we demonstrate its superior ability to assign "share of control" to individual reactions with respect to metabolic functions and environmental conditions. A comparative analysis of various scenarios illustrates the usefulness of FC and its relations to other structural approaches pertaining to metabolic control. We propose a Monte Carlo algorithm to estimate FCs for large networks, based on the enumeration of elementary flux modes. We further give detailed biological interpretation of FCs for production of lactate and ATP under various respiratory conditions.

  9. Assessment on tracking error performance of Cascade P/PI, NPID and N-Cascade controller for precise positioning of xy table ballscrew drive system

    Science.gov (United States)

    Abdullah, L.; Jamaludin, Z.; Rafan, N. A.; Jamaludin, J.; Chiew, T. H.

    2013-12-01

    At present, positioning plants in machine tools are looking for high degree of accuracy and robustness attributes for the purpose of compensating various disturbance forces. The objective of this paper is to assess the tracking performance of Cascade P/PI, Nonlinear PID (NPID) and Nonlinear cascade (N-Cascade) controller with the existence of disturbance forces in the form of cutting forces. Cutting force characteristics at different cutting parameters; such as spindle speed rotations is analysed using Fast Fourier Transform. The tracking performance of a Nonlinear cascade controller in presence of these cutting forces is compared with NPID controller and Cascade P/PI controller. Robustness of these controllers in compensating different cutting characteristics is compared based on reduction in the amplitudes of cutting force harmonics using Fast Fourier Transform. It is found that the N-cascade controller performs better than both NPID controller and Cascade P/PI controller. The average percentage error reduction between N-cascade controller and Cascade P/PI controller is about 65% whereas the average percentage error reduction between cascade controller and NPID controller is about 82% at spindle speed of 3000 rpm spindle speed rotation. The finalized design of N-cascade controller could be utilized further for machining application such as milling process. The implementation of N-cascade in machine tools applications will increase the quality of the end product and the productivity in industry by saving the machining time. It is suggested that the range of the spindle speed could be made wider to accommodate the needs for high speed machining.

  10. METHODICAL TUNING OF PROPORTIONAL PLUS INTEGRAL CONTROLLERS FOR CASCADE CONTROL OF SEPARATELY EXCITED DC MOTORS

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    Ibrahim Al-Abbas

    2012-01-01

    Full Text Available The cascade control of DC motors by PI controllers was extensively used in industry. Approximation rules based on plotting the output of the system or on computer simulation were used to determine the parameters of these controllers. This study was done to develop mathematical expressions to calculate the parameters of these controllers. Output time functions of the system and there derivatives were used to obtain mathematical relationships relating directly the motor parameters and the controller parameters. These relationships were used in tuning process of the cascade system. The dynamic performances of the system were examined in single loop form and in closed loop form for a step change in control variable (the input voltage as well as for step change in disturbance (mechanical load. The performances of current closed loop system and the speed closed loop were acceptable. The steady state error was zero and the maximum overshoot was less than 20%. The developed relationships can be used in design and analysis of cascade DC drive systems and cascade AC drive systems.

  11. Out of control: Fluctuation of cascading dynamics in networks

    Science.gov (United States)

    Wang, Jianwei; Cai, Lin; Xu, Bo; Li, Peng; Sun, Enhui; Zhu, Zhiguo

    2016-11-01

    Applying two preferential selection mechanisms of flow destination, we develop two new methods to quantify the initial load of a node, where the flow is transported along the shortest path between two nodes. We propose a simple cascading model and study cascading dynamics induced by attacking the node with the highest load in some synthetic and actual networks. Surprisingly, we observe the abnormal fluctuation of cascading dynamics, i.e., more damage can be triggered if we spend significantly higher cost to protect a network. In particular, this phenomenon is independent of the initial flow distribution and the preferential selection mechanisms of flow destination. However, it remains unclear which specific structural patterns may affect the fluctuation of cascading dynamics. In this paper, we examine the local evolution of the cascading propagation by constructing some special networks. We show that revivals of some nodes in the double ring structure facilitate the transportation of the flow between two unconnected sub-networks, cause more damage and subsequently lead to the abnormal fluctuation of cascading dynamics. Compared with the traditional definition of the betweenness, we adopt two new proposed methods to further evaluate the resilience of several actual networks. We find that some real world networks reach the strongest resilience level against cascading failures in our preferential selection mechanisms of flow destination. Moreover, we explore how to use the minimum cost to maximize the resilience of the studied networks.

  12. Metabolic control of renin secretion.

    Science.gov (United States)

    Peti-Peterdi, János; Gevorgyan, Haykanush; Lam, Lisa; Riquier-Brison, Anne

    2013-01-01

    One emerging topic in renin-angiotensin system (RAS) research is the direct local control of renin synthesis and release by endogenous metabolic intermediates. During the past few years, our laboratory has characterized the localization and signaling of the novel metabolic receptor GPR91 in the normal and diabetic kidney and established GPR91 as a new, direct link between high glucose and RAS activation in diabetes. GPR91 (also called SUCNR1) binds tricarboxylic acid (TCA) cycle intermediate succinate which can rapidly accumulate in the local tissue environment when energy supply and demand are out of balance. In a variety of physiological and pathological conditions associated with metabolic stress, succinate signaling via GPR91 appears to be an important mediator or modulator of renin secretion. This review summarizes our current knowledge on the control of renin release by molecules of endogenous metabolic pathways with the main focus on succinate/GPR91.

  13. Adaptive control of systems in cascade with saturation

    Science.gov (United States)

    Kannan, Suresh K.

    This thesis extends the use of neural-network-based model reference adaptive control to systems that occur as cascades. In general, these systems are not feedback linearizable. The approach taken is that of approximate feedback linearization of upper subsystems whilst treating the lower-subsystem states as virtual actuators. Similarly, lower-subsystems are also feedback linearized. Typically, approximate inverses are used for linearization purposes. Model error arising from the use of an approximate inverse is minimized using a neural-network as an adaptive element. Incorrect adaptation due to (virtual) actuator saturation and dynamics is avoided using the Pseudocontrol Hedging method. Using linear approximate inverses and linear reference models generally result in large desired pseudocontrol for large external commands. Even if the provided external command is feasible (null-controllable), there is no guarantee that the reference model trajectory is feasible. In order to mitigate this, nonlinear reference models based on nested-saturation methods are used to constrain the evolution of the reference model and thus the plant states. The method presented in this thesis lends itself to the inner-outer loop control of air vehicles, where the inner-loop controls attitude dynamics and the outer-loop controls the translational dynamics of the vehicle. The outer-loop treats the closed loop attitude dynamics as an actuator. Adaptation to uncertainty in the attitude, as well as the translational dynamics, is introduced, thus minimizing the effects of model error in all six degrees of freedom and leading to more accurate position tracking. A pole-placement approach is used to choose compensator gains for the tracking error dynamics. This alleviates timescale separation requirements, allowing the outer loop bandwidth to be closer to that of the inner loop, thus increasing position tracking performance. A poor model of the attitude dynamics and a basic kinematics model is

  14. DISOPE distributed model predictive control of cascade systems with network communication

    Institute of Scientific and Technical Information of China (English)

    Yan ZHANG; Shaoyuan LI

    2005-01-01

    A novel distributed model predictive control scheme based on dynamic integrated system optimization and parameter estimation (DISOPE) was proposed for nonlinear cascade systems under network environment.Under the distributed control structure,online optimization of the cascade system was composed of several cascaded agents that can cooperate and exchange information via network communication.By iterating on modified distributed linear optimal control problems on the basis of estimating parameters at every iteration the correct optimal control action of the nonlinear model predictive control problem of the cascade system could be obtained,assuming that the algorithm was convergent.This approach avoids solving the complex nonlinear optimization problem and significantly reduces the computational burden.The simulation results of the fossil fuel power unit are illustrated to verify the effectiveness and practicability of the proposed algorithm.

  15. Control of Corner Separation with Plasma Actuation in a High-Speed Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Haideng Zhang

    2017-04-01

    Full Text Available The performances of modern highly loaded compressors are limited by the corner separations. Plasma actuation is a typical active flow control methodology, which has been proven to be capable of controlling the corner separations in low-speed compressor cascades. The main purpose of this paper is to uncover the flow control law and the mechanism of high-speed compressor cascade corner separation control with plasma actuations. The control effects of the suction surface as well as the endwall plasma actuations in suppressing the high-speed compressor cascade flow separations are investigated with numerical methods. The main flow structures within the high-speed compressor cascade corner separation and the development of the corresponding flow loss are investigated firstly. Next, the performances of plasma actuations in suppressing the high-speed compressor cascade corner separation are studied. At last, the mechanisms behind the control effects of the suction surface and the endwall plasma actuations are discussed. Both the suction surface and the endwall plasma actuations can improve the high-speed compressor cascade static pressure rise coefficient, while reducing the corresponding total pressure loss and blockage coefficients. The suction surface plasma actuation can suppress not only the high-speed compressor cascade corner separation vortex but also the airfoil separation, so, compared to the endwall plasma actuation, the suction surface plasma actuation is more efficient in reducing the total pressure loss of the high-speed compressor cascade. However, through suppressing the development of the passage vortex, the endwall plasma actuation is more efficient in reducing the flow blockage and improving the static pressure rise of the high-speed compressor cascade.

  16. Digital redesign of anti-wind-up controller for cascaded analog system.

    Science.gov (United States)

    Chen, Y S; Tsai, J S H; Shieh, L S; Moussighi, M M

    2003-01-01

    The cascaded conventional anti-wind-up (CAW) design method for integral controller is discussed. Then, the prediction-based digital redesign methodology is utilized to find the new pulse amplitude modulated (PAM) digital controller for effective digital control of the analog plant with input saturation constraint. The desired digital controller is determined from existing or pre-designed CAW analog controller. The proposed method provides a novel methodology for indirect digital design of a continuous-time unity output-feedback system with a cascaded analog controller as in the case of PID controllers for industrial control processes with the presence of actuator saturations. It enables us to implement an existing or pre-designed cascaded CAW analog controller via a digital controller effectively.

  17. A Comparative Modelling Study of PWM Control Techniques for Multilevel Cascaded Inverter

    Directory of Open Access Journals (Sweden)

    A. TAHRI

    2005-01-01

    Full Text Available The emergence of multilevel converters has been in increase since the last decade. These new types of converters are suitable for high voltage and high power application due to their ability to synthesize waveforms with better harmonic spectrum. Numerous topologies have been introduced and widely studied for utility and drive applications. Amongst these topologies, the multilevel cascaded inverter was introduced in Static Var compensation and drive systems. This paper investigates several control techniques applied to the Multilevel Cascaded Inverter in order to ensure an efficient voltage utilization and better harmonic spectrum. A modelling and control strategy of a single phase Multilevel Cascaded Inverter is also investigated. Computer simulation results using Matlab program are reported and discussed together with a comparative study of the different control techniques of multilevel cascaded inverter.Moreover, experimental results are carried out on a scaled down prototype to prove the effectiveness of the proposed analysis.

  18. A phosphorylation cascade controls the degradation of active SREBP1.

    Science.gov (United States)

    Bengoechea-Alonso, Maria T; Ericsson, Johan

    2009-02-27

    Sterol regulatory element-binding proteins (SREBPs) are a family of transcription factors that regulates cholesterol and lipid metabolism. The active forms of these transcription factors are targeted by a number of post-translational modifications, including phosphorylation. Phosphorylation of Thr-426 and Ser-430 in SREBP1a creates a docking site for the ubiquitin ligase Fbw7, resulting in the degradation of the transcription factor. Here, we identify a novel phosphorylation site in SREBP1a, Ser-434, which regulates the Fbw7-dependent degradation of SREBP1. We demonstrate that both SREBP1a and SREBP1c are phosphorylated on this residue (Ser-410 in SREBP1c). Importantly, we demonstrate that the mature form of endogenous SREBP1 is phosphorylated on Ser-434. Glycogen synthase kinase-3 phosphorylates Ser-434, and the phosphorylation of this residue is attenuated in response to insulin signaling. Interestingly, phosphorylation of Ser-434 promotes the glycogen synthase kinase-3-dependent phosphorylation of Thr-426 and Ser-430 and destabilizes SREBP1. Consequently, mutation of Ser-434 blocks the interaction between SREBP1 and Fbw7 and attenuates Fbw7-dependent degradation of SREBP1. Importantly, insulin fails to enhance the levels of mature SREBP1 in cells lacking Fbw7. Thus, the degradation of mature SREBP1 is controlled by cross-talk between multiple phosphorylated residues in its C-terminal domain and the phosphorylation of Ser-434 could function as a molecular switch to control these processes.

  19. Experimental Studies on The Mechanism and COntrol of Secondary Flow Losses in Turbine Cascades

    Institute of Scientific and Technical Information of China (English)

    WangZhongqi; HanWanjin; 等

    1992-01-01

    This paper summarizes the results of the authors' 4 year experimental studies on the secondary flow losses in turbine cascades.cascade wind tunnel experiments were carried out concerning the influence of aspect rations,incidence,turning angles and outer endwall divergent angles in order to unveil the evolution mechanism of secondary flow losses in turbine cascades without end clearance.Some methods for controlling the secondary flows are investigated including the blade leaning,blade cambering,endwall convergence and leading edge extension at two ends of the blade.

  20. Novel regulatory cascades controlling expression of nitrogen-fixation genes in Geobacter sulfurreducens.

    Science.gov (United States)

    Ueki, Toshiyuki; Lovley, Derek R

    2010-11-01

    Geobacter species often play an important role in bioremediation of environments contaminated with metals or organics and show promise for harvesting electricity from waste organic matter in microbial fuel cells. The ability of Geobacter species to fix atmospheric nitrogen is an important metabolic feature for these applications. We identified novel regulatory cascades controlling nitrogen-fixation gene expression in Geobacter sulfurreducens. Unlike the regulatory mechanisms known in other nitrogen-fixing microorganisms, nitrogen-fixation gene regulation in G. sulfurreducens is controlled by two two-component His-Asp phosphorelay systems. One of these systems appears to be the master regulatory system that activates transcription of the majority of nitrogen-fixation genes and represses a gene encoding glutamate dehydrogenase during nitrogen fixation. The other system whose expression is directly activated by the master regulatory system appears to control by antitermination the expression of a subset of the nitrogen-fixation genes whose transcription is activated by the master regulatory system and whose promoter contains transcription termination signals. This study provides a new paradigm for nitrogen-fixation gene regulation.

  1. DC-link Voltage Coordinative-Proportional Control in Cascaded Converter Systems

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin

    2015-01-01

    PI controllers are frequently implemented in cascaded converter system to control the DC-link voltage, because they can achieve zero steady state error. However the PI controller adds a pole at the origin point and a zero on the left half plane, and it increases the control system type number, an...

  2. Laser-Doppler velocimeter measurements in a cascade of controlled diffusion compressor blades at stall

    OpenAIRE

    Ganaim Rickel, Humberto Javier

    1994-01-01

    Approved for public release, distribution unlimited An incipient compressor blade stall has been generated and examined in the Low Speed Cascade Wind Tunnel at the Turbopropulsion Laboratory. The test blades were a controlled-diffusion design with solidity 1.67, and stalling occurred at 10 degrees of incidence above the design inlet air angle. Tufting and laser-sheet flow-visualization techniques showed that the stalling process was unsteady, and occurred over the whole cascade of 20 blade...

  3. Optical mode control of surface-plasmon quantum cascade lasers

    Science.gov (United States)

    Moreau, V.; Bahriz, M.; Palomo, J.; Wilson, L. R.; Krysa, A. B.; Sirtori, C.; Austin, D. A.; Cockburn, J. W.; Roberts, J. S.; Colombelli, R.

    2007-04-01

    Surface-plasmon waveguides based on metallic strips can provide a two dimensional optical confinement. This concept has been successfully applied to quantum cascade lasers, processed as ridge waveguides, to demonstrate that the lateral extension of the optical mode can be influenced solely by the width of the device top contact. For devices operating at a wavelength of λ ≈7.5 μm, the room-temperature threshold current density was reduced from 6.3 kA/cm2 to 4.4 kA/cm2 with respect to larger devices with full top metallization.

  4. A novel anti-windup framework for cascade control systems: an application to underactuated mechanical systems.

    Science.gov (United States)

    Mehdi, Niaz; Rehan, Muhammad; Malik, Fahad Mumtaz; Bhatti, Aamer Iqbal; Tufail, Muhammad

    2014-05-01

    This paper describes the anti-windup compensator (AWC) design methodologies for stable and unstable cascade plants with cascade controllers facing actuator saturation. Two novel full-order decoupling AWC architectures, based on equivalence of the overall closed-loop system, are developed to deal with windup effects. The decoupled architectures have been developed, to formulate the AWC synthesis problem, by assuring equivalence of the coupled and the decoupled architectures, instead of using an analogy, for cascade control systems. A comparison of both AWC architectures from application point of view is provided to consolidate their utilities. Mainly, one of the architecture is better in terms of computational complexity for implementation, while the other is suitable for unstable cascade systems. On the basis of the architectures for cascade systems facing stability and performance degradation problems in the event of actuator saturation, the global AWC design methodologies utilizing linear matrix inequalities (LMIs) are developed. These LMIs are synthesized by application of the Lyapunov theory, the global sector condition and the ℒ2 gain reduction of the uncertain decoupled nonlinear component of the decoupled architecture. Further, an LMI-based local AWC design methodology is derived by utilizing a local sector condition by means of a quadratic Lyapunov function to resolve the windup problem for unstable cascade plants under saturation. To demonstrate effectiveness of the proposed AWC schemes, an underactuated mechanical system, the ball-and-beam system, is considered, and details of the simulation and practical implementation results are described.

  5. NEURAL CASCADED WITH FUZZY SCHEME FOR CONTROL OF A HYDROELECTRIC POWER PLANT

    Directory of Open Access Journals (Sweden)

    A. Selwin Mich Priyadharson

    2014-01-01

    Full Text Available A novel design for flow and level control in a hydroelectric power plant using Programmable Logic Controller (PLC-Human Machine Interface (HMI and neural cascaded with fuzzy scheme is proposed. This project will focus on design and development of flow and level controller for small scale hydro generating units by implementing gate control based on PLC-HMI with the proposed scheme. The existing control schemes have so many difficulties to manage intrinsic time delay, nonlinearity due to uncertainty of the process and frequent load changes. This study presents the design of neuro controllers to regulate level, cascaded with fuzzy controller to control flow in gate valve to the turbine. A prototype model is fabricated in the laboratory as experimental setup for flow and level control and real time simulation studies were carried out using PID and neural cascaded with fuzzy scheme. The designed prototype model is fabricated with 5 levels in the upper tank and 2 levels in the lower tank. Based on the outputs of the level sensors from the upper and lower tanks, the ladder logic is actuated. This project work uses PLC of Bernecker and Rainer (B and R Industrial Automation inbuilt with 20 digital inputs and provides 12 potential free outputs to control the miniaturized process depicted in this work. Finally, the performance of the proposed neural cascaded with fuzzy scheme is evaluated by simulation results by comparing with conventional controllers output using real time data obtained from the hydro power plant. The advantages of the proposed neural cascaded with fuzzy scheme over the existing controllers are highlighted.

  6. Hydrological controls on cascade reservoirs regulating phosphorus retention and downriver fluxes.

    Science.gov (United States)

    Lu, Ting; Chen, Nengwang; Duan, Shuiwang; Chen, Zhuhong; Huang, Bangqin

    2016-12-01

    Many coastal rivers have a system of cascade reservoirs, but the role of these reservoirs in regulating nutrient transport from watershed to coast is still unknown. In this study, phosphorus (P) in surface water and top sediment was investigated along the North Jiulong River (southeast China) under three hydrological conditions (high flow, medium flow and low flow) in 2012-2013, and P dynamics in a cascade reservoir (Xipi Reservoir) were studied on a monthly scale. Results showed that the concentrations of dissolved reactive phosphorus (DRP) consistently decreased longitudinally in the upper river with the lowest values observed in the section of cascade reservoirs, likely due to tributary inputs and in situ uptakes. The decrease was most rapid during base flow when DRP was highest in the free-flowing river section and lowest in cascade reservoirs. Results from monthly monitoring on the Xipi Reservoir showed general downriver decreases in DRP, total particulate phosphorus (TPP) and total phosphorus (TP) in the riverine zone and transition zone. Mass balance results on an annual basis suggest that the Xipi Reservoir (lacustrine zone) was an overall sink for TPP (6 % retention) but somewhat a source of DRP (-0.3 %) with TP retention (1 %). Even scaled up to the whole cascade reservoir system, P retention was low compared with worldwide reservoirs, which we ascribe to the high P loading and short hydraulic residence time. Nevertheless, major processes controlling P retention in coastal rivers with cascade reservoirs varied from sedimentation in the dry-cold season to biotic transformation in the wet-warm season, thereby affecting loading and composition of P from watershed to the coast. This study highlights the hydrological controls on the role of cascade reservoirs in regulating P retention and downriver fluxes in different seasons.

  7. A Predictive Neural Network-Based Cascade Control for pH Reactors

    Directory of Open Access Journals (Sweden)

    Mujahed AlDhaifallah

    2016-01-01

    Full Text Available This paper is concerned with the development of predictive neural network-based cascade control for pH reactors. The cascade structure consists of a master control loop (fuzzy proportional-integral and a slave one (predictive neural network. The master loop is chosen to be more accurate but slower than the slave one. The strong features found in cascade structure have been added to the inherent features in model predictive neural network. The neural network is used to alleviate modeling difficulties found with pH reactor and to predict its behavior. The parameters of predictive algorithm are determined using an optimization algorithm. The effectiveness and feasibility of the proposed design have been demonstrated using MatLab.

  8. Control valves and cascades for the first stages of turbines with ultrasupercritical steam parameters

    Science.gov (United States)

    Zaryankin, A. E.; Rogalev, N. D.; Rogalev, A. N.; Garanin, I. V.; Osipov, S. K.; Grigoriev, E. Yu.

    2016-06-01

    This paper considers the problems that will unavoidably be encountered in the creation of new-generation turbines operated at ultrasupercritical initial steam parameters, namely, the development of new control and shutoff valves, the reduction of end energy losses in blade cascades and steam leaks in high-pressure cylinders (HPCs), the elimination of effect produced by regenerative steam bleedoffs on the afterextraction stage, the cooling of a blade cascade, etc. Some possible solutions are given for the two first of the listed problems. The conclusion about the need for the transition to new-generation control valves in the development of new advanced steam turbines with ultrasupercritical initial steam parameters has been made. From the viewpoint of their design, the considered new-generation valves differ from the known contemporary constructions by a shaped axially symmetric confusor channel and perforated zones on the streamlined spool surface and the inlet diffuser saddle part. The analysis of the vibration behavior of new-generation valves has demonstrated a decrease in the dynamic loads acting on their stems. To reduce the end energy losses in nozzle or blade cascades with small aspect ratios, it is proposed to use finned shrouds in the interblade channels. The cross section of fins has a triangular profile, and their height must be comparable with the thickness of the boundary layer in the outlet cross section of a cascade and, provisionally, be smaller than 8% of the cascade chord.

  9. A respiratory chain controlled signal transduction cascade in the mitochondrial intermembrane space mediates hydrogen peroxide signaling.

    Science.gov (United States)

    Patterson, Heide Christine; Gerbeth, Carolin; Thiru, Prathapan; Vögtle, Nora F; Knoll, Marko; Shahsafaei, Aliakbar; Samocha, Kaitlin E; Huang, Cher X; Harden, Mark Michael; Song, Rui; Chen, Cynthia; Kao, Jennifer; Shi, Jiahai; Salmon, Wendy; Shaul, Yoav D; Stokes, Matthew P; Silva, Jeffrey C; Bell, George W; MacArthur, Daniel G; Ruland, Jürgen; Meisinger, Chris; Lodish, Harvey F

    2015-10-20

    Reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) govern cellular homeostasis by inducing signaling. H2O2 modulates the activity of phosphatases and many other signaling molecules through oxidation of critical cysteine residues, which led to the notion that initiation of ROS signaling is broad and nonspecific, and thus fundamentally distinct from other signaling pathways. Here, we report that H2O2 signaling bears hallmarks of a regular signal transduction cascade. It is controlled by hierarchical signaling events resulting in a focused response as the results place the mitochondrial respiratory chain upstream of tyrosine-protein kinase Lyn, Lyn upstream of tyrosine-protein kinase SYK (Syk), and Syk upstream of numerous targets involved in signaling, transcription, translation, metabolism, and cell cycle regulation. The active mediators of H2O2 signaling colocalize as H2O2 induces mitochondria-associated Lyn and Syk phosphorylation, and a pool of Lyn and Syk reside in the mitochondrial intermembrane space. Finally, the same intermediaries control the signaling response in tissues and species responsive to H2O2 as the respiratory chain, Lyn, and Syk were similarly required for H2O2 signaling in mouse B cells, fibroblasts, and chicken DT40 B cells. Consistent with a broad role, the Syk pathway is coexpressed across tissues, is of early metazoan origin, and displays evidence of evolutionary constraint in the human. These results suggest that H2O2 signaling is under control of a signal transduction pathway that links the respiratory chain to the mitochondrial intermembrane space-localized, ubiquitous, and ancient Syk pathway in hematopoietic and nonhematopoietic cells.

  10. Detection of vulnerable relays and sensitive controllers under cascading events based on performance indices

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Hu, Yanting

    2014-01-01

    The unexpected relay operations have been regarded as one of main reasons to propagate and induce the cascaded blackouts. It is significant to timely detect vulnerable relays to be blocked, and locate sensitive controllers to regulate the emergency states. In this paper, a multi agent system (MAS...

  11. Cascade Controller Including Back-stepping for Hydraulic-Mechanical Systems

    DEFF Research Database (Denmark)

    Choux, Martin; Hovland, Geir; Blanke, Mogens

    2012-01-01

    Development of a cascade controller structure including adaptive backstepping for a nonlinear hydraulic-mechanical system is considered in this paper where a dynamic friction (LuGre) model is included to obtain the necessary accuracy. The paper compares the performance of two variants of an adapt...

  12. Null controllability for linear parabolic cascade systems with interior degeneracy

    Directory of Open Access Journals (Sweden)

    Idriss Boutaayamou

    2016-11-01

    Full Text Available We study the null controllability problem for linear degenerate parabolic systems with one control force through Carleman estimates for the associated adjoint problem. The novelty of this article is that for the first time it is considered a problem with an interior degeneracy and a control set that only requires to contain an interval lying on one side of the degeneracy points. The obtained result improves and complements a number of earlier works. As a consequence, observability inequalities are established.

  13. Shareholding Cascades : The Separation of Ownership and Control in Belgium

    NARCIS (Netherlands)

    Becht, M.C.; Chapelle, A.; Renneboog, L.D.R.

    1999-01-01

    This paper analyses the control of Belgian listed companies. The analysis reveals that control of listed companies in Belgium is highly concentrated. Business groups, holding companies, and voting pacts, play an important role in bringing about this concentration. The main characteristics of the Bel

  14. Nonlinear Cascade Strategy for Longitudinal Control of Electric Vehicle.

    Science.gov (United States)

    El Majdoub, K; Giri, F; Ouadi, H; Chaoui, F Z

    2014-01-01

    The problem of controlling the longitudinal motion of front-wheels electric vehicle (EV) is considered making the focus on the case where a single dc motor is used for both front wheels. Chassis dynamics are modelled applying relevant fundamental laws taking into account the aerodynamic effects and the road slope variation. The longitudinal slip, resulting from tire deformation, is captured through Kiencke's model. Despite its highly nonlinear nature the complete model proves to be utilizable in longitudinal control design. The control objective is to achieve a satisfactory vehicle speed regulation in acceleration/deceleration stages, despite wind speed and other parameters uncertainty. An adaptive controller is developed using the backstepping design technique. The obtained adaptive controller is shown to meet its objectives in presence of the changing aerodynamics efforts and road slope.

  15. Double closed-loop cascade control for lower limb exoskeleton with elastic actuation.

    Science.gov (United States)

    Zhu, Yanhe; Zheng, Tianjiao; Jin, Hongzhe; Yang, Jixing; Zhao, Jie

    2015-01-01

    Unlike traditional rigid actuators, the significant features of Series Elastic Actuator (SEA) are stable torque control, lower output impedance, impact resistance and energy storage. Recently, SEA has been applied in many exoskeletons. In such applications, a key issue is how to realize the human-exoskeleton movement coordination. In this paper, double closed-loop cascade control for lower limb exoskeleton with SEA is proposed. This control method consists of inner SEA torque loop and outer contact force loop. Utilizing the SEA torque control with a motor velocity loop, actuation performances of SEA are analyzed. An integrated exoskeleton control system is designed, in which joint angles are calculated by internal encoders and resolvers and contact forces are gathered by external pressure sensors. The double closed-loop cascade control model is established based on the feedback signals of internal and external sensor. Movement experiments are accomplished in our prototype of lower limb exoskeleton. Preliminary results indicate the exoskeleton movements with pilot can be realized stably by utilizing this double closed-loop cascade control method. Feasibility of the SEA in our exoskeleton robot and effectiveness of the control method are verified.

  16. Optimized cascade reservoir operation considering ice flood control and power generation

    Science.gov (United States)

    Chang, Jianxia; Meng, Xuejiao; Wang, ZongZhi; Wang, Xuebin; Huang, Qiang

    2014-11-01

    Ice flood control is an important objective for reservoir operation in cold regions. Maintaining the reservoir outflow in a certain range is considered an effective way to remediate ice flood damage. However, this strategy may decrease the socio-economic benefit of reservoirs, for example, reduction of hydropower production. These conflicting objectives cause a dilemma for water managers when defining reservoir operation policy. This study considers seven cascade reservoirs in the upstream Yellow River, and ice flood control storage is introduced to balance the hydropower generation and ice flood control. The relation between the ice flood control storage volume of the Liujiaxia reservoir and cascade power output is analyzed. An optimization model to explore the trade-offs between hydropower generation and ice flood control requirements is developed. The model takes into account ice flood control requirements. The optimization model compared to simulation model based on the reservoir operation rule curves. The results show that the optimal operation rules are far more efficient in balancing the benefits within the power generation and ice flood control. The cascade reservoirs operation strategies proposed in this study can be effectively and suitably used in reservoir operation systems with similar conditions.

  17. Flow separation control by using bowed blade in highly loaded turbine cascades

    Institute of Scientific and Technical Information of China (English)

    YAMAMOTO; Atsumasa

    2009-01-01

    Due to the serious flow separations and centralized vortices,there are high secondary losses in highly loaded turbines.It is imperative to find measures to control the flow separation and vortices hence improve the turbine performance.This paper reports our recent progress on flow separation and vor-tices control in highly loaded turbine cascades by using bowed blades.Two sets of highly loaded tur-bine cascades with the turning angles of 113° and 160°,and each with 7 bowed blade angles 0°(straight),±10°,±20° and ±30° were experimentally investigated.Both internal flow field measurement and flow visualization on the blade surfaces were conducted,and the effects of blade bowing on the flow topology,distribution of vorticity and the flow energy loss were discussed.The results show that,for the cascade with the turning angle of 113°,the appropriately positive bow angle could reduce the flow energy loss;whereas for the cascade with the turning angle of 160°,the well selected negative bow angle can give the better aerodynamic performance.

  18. Flow separation control by using bowed blade in highly loaded turbine cascades

    Institute of Scientific and Technical Information of China (English)

    TAN ChunQing; ZHANG HuaLiang; CHEN HaiSheng; DONG XueZhi; ZHAO HongLei; YAMAMOTO Atsumasa

    2009-01-01

    Due to the serious flow separations and centralized vortices, there are high secondary losses in highly loaded turbines. It is imperative to find measures to control the flow separation and vortices hence improve the turbine performance. This paper reports our recent progress on flow separation and vor-tices control in highly loaded turbine cascades by using bowed blades. Two sets of highly loaded tur-bine cascades with the turning angles of 113°and 160°, and each with 7 bowed blade angles 0°(straight),±10°, ±20° and ±30° were experimentally investigated. Both internal flow field measurement and flow visualization on the blade surfaces were conducted, and the effects of blade bowing on the flow topology, distribution of vorticity and the flow energy loss were discussed. The results show that, for the cascade with the turning angle of 113°, the appropriately positive bow angle could reduce the flow energy loss; whereas for the cascade with the turning angle of 160°, the well selected negative bow angle can give the better aerodynamic performance.

  19. Decentralized closed-loop identification and controller design for a kind of cascade processes

    Institute of Scientific and Technical Information of China (English)

    Chen Qing; Li Shaoyuan; Xi Yugeng

    2005-01-01

    A new decentralized closed-loop identification and predictive controller design method for a kind of cascade processes composed of several sub-processes is studied. This kind of cascade processes has the characteristics of one-way connection. The process is divided into several two-input-two-output (TITO) sub-systems. The parameters of the first-order plus dead-time models for the transfer function matrices can be obtained using least squares method. Hence a distributed model predictive controller is designed based on the coupling models of each sub-process. Simulation results on the temperature control of a reheating furnace are given to show the efficiency of the algorithm.

  20. Insulin receptor substrate signaling controls cardiac energy metabolism and heart failure.

    Science.gov (United States)

    Guo, Cathy A; Guo, Shaodong

    2017-06-01

    The heart is an insulin-dependent and energy-consuming organ in which insulin and nutritional signaling integrates to the regulation of cardiac metabolism, growth and survival. Heart failure is highly associated with insulin resistance, and heart failure patients suffer from the cardiac energy deficiency and structural and functional dysfunction. Chronic pathological conditions, such as obesity and type 2 diabetes mellitus, involve various mechanisms in promoting heart failure by remodeling metabolic pathways, modulating cardiac energetics and impairing cardiac contractility. Recent studies demonstrated that insulin receptor substrates 1 and 2 (IRS-1,-2) are major mediators of both insulin and insulin-like growth factor-1 (IGF-1) signaling responsible for myocardial energetics, structure, function and organismal survival. Importantly, the insulin receptor substrates (IRS) play an important role in the activation of the phosphatidylinositide-3-dependent kinase (PI-3K) that controls Akt and Foxo1 signaling cascade, regulating the mitochondrial function, cardiac energy metabolism and the renin-angiotensin system. Dysregulation of this branch in signaling cascades by insulin resistance in the heart through the endocrine system promotes heart failure, providing a novel mechanism for diabetic cardiomyopathy. Therefore, targeting this branch of IRS→PI-3K→Foxo1 signaling cascade and associated pathways may provide a fundamental strategy for the therapeutic and nutritional development in control of metabolic and cardiovascular diseases. In this review, we focus on insulin signaling and resistance in the heart and the role energetics play in cardiac metabolism, structure and function. © 2017 Society for Endocrinology.

  1. Control of endwall secondary flow in a compressor cascade with dielectric barrier discharge plasma actuation

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Three dielectric barrier discharge plasma actuators were mounted at the positions of 20%,40%and 60%of chord length on the endwall in a compressor cascade.The downstream flow field of the cascade has been measured with a mini five-hole pressure probe with and without the plasma actuation.The measured results show that the plasma actuation most effectively reduces total pressure loss and flow blockage when the actuators are operated simultaneously.As each of the actuators is operated independently,the actuator at the position of 20%of chord length most effectively reduces flow blockage, and the actuator at the position of 60%of chord length fairly reduces total pressure loss.However, negative pressure loss reduction occurs with the plasma actuator at the position of 40%of chord length.In brief,the plasma actuation placed on the endwall in the cascade apparently influences the endwall secondary flow,and the optimal locations and strength of actuation are critical for the control of endwall secondary flow in a compressor cascade with the plasma actuators.

  2. Prediction and Control of Network Cascade: Example of Power Grid or Networking Adaptability from WMD Disruption and Cascading Failures

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory

    2012-07-24

    The goal of the DTRA project is to develop a mathematical framework that will provide the fundamental understanding of network survivability, algorithms for detecting/inferring pre-cursors of abnormal network behaviors, and methods for network adaptability and self-healing from cascading failures.

  3. Prediction and Control of Network Cascade: Example of Power Grid or Networking Adaptability from WMD Disruption and Cascading Failures

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory

    2012-07-24

    The goal of the DTRA project is to develop a mathematical framework that will provide the fundamental understanding of network survivability, algorithms for detecting/inferring pre-cursors of abnormal network behaviors, and methods for network adaptability and self-healing from cascading failures.

  4. Particle image velocimetry of active flow control on a compressor cascade

    Energy Technology Data Exchange (ETDEWEB)

    Hecklau, M.; Rennings, R. van; Zander, V.; Nitsche, W. [Technische Universitaet Berlin, Department of Aeronautics and Astronautics, Berlin (Germany); Huppertz, A.; Swoboda, M. [Rolls-Royce Deutschland Ltd. and Co. KG, Dahlewitz (Germany)

    2011-04-15

    AFC (Active Flow Control) experiments have been performed by means of steady and pulsed blowing out of the sidewalls as well as out of the blade's suction surface in a highly loaded compressor cascade. PIV (Particle Image Velocimetry) was used to evaluate the fully three-dimensional internal flow field and the impact of AFC methods. The aim was to observe the secondary flow structures and flow instabilities by PIV, to tune the AFC device operation parameters. This paper summarizes the different PIV measurements performed at the stator cascade to give an overview of the dominant flow features in the passage flow field and to obtain a detailed view of control mechanisms. In addition, a new vortex detection method is presented, based on a 2D-wavelet which is applicable in two-dimensional velocity data fields. (orig.)

  5. CONTROL OF POLLUTANT EMISSIONS IN NATURAL GAS DIFFUSION FLAMES BY USING CASCADE BURNERS

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Ala Qubbaj

    2001-12-30

    The goal of this exploratory research project is to control the pollutant emissions of diffusion flames by modifying the air infusion rate into the flame. The modification was achieved by installing a cascade of venturis around the burning gas jet. The basic idea behind this technique is controlling the stoichiometry of the flame through changing the flow dynamics and rates of mixing in the combustion zone with a set of venturis surrounding the flame. A natural gas jet diffusion flame at burner-exit Reynolds number of 5100 was examined with a set of venturis of specific sizes and spacing arrangement. The thermal and composition fields of the baseline and venturi-cascaded flames were numerically simulated using CFD-ACE+, an advanced computational environment software package. The instantaneous chemistry model was used as the reaction model. The concentration of NO was determined through CFD-POST, a post processing utility program for CFD-ACE+. The numerical results showed that, in the near-burner, midflame and far-burner regions, the venturi-cascaded flame had lower temperature by an average of 13%, 19% and 17%, respectively, and lower CO{sub 2} concentration by 35%, 37% and 32%, respectively, than the baseline flame. An opposite trend was noticed for O{sub 2} concentration; the cascaded flame has higher O{sub 2} concentration by 7%, 26% and 44%, in average values, in the near-burner, mid-flame and far-burner regions, respectively, than in the baseline case. The results also showed that, in the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame has lower NO concentrations by 89%, 70% and 70%, in average values, respectively, compared to the baseline case. The numerical results substantiate that venturi-cascading is a feasible method for controlling the pollutant emissions of a burning gas jet. In addition, the numerical results were useful to understand the thermo-chemical processes involved. The results showed that the prompt-NO mechanism

  6. H∞ Networked Cascade Control System Design for Turboshaft Engines with Random Packet Dropouts

    Directory of Open Access Journals (Sweden)

    Xiaofeng Liu

    2017-01-01

    Full Text Available The distributed control architecture becomes more and more important in future gas turbine engine control systems, in which the sensors and actuators will be connected to the controllers via a network. Therefore, the control problem of network-enabled high-performance distributed engine control (DEC has come to play an important role in modern gas turbine control systems, while, due to the properties of the network, the packet dropouts must be considered. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS. Typical turboshaft engine distributed controllers are designed based on the NCCS framework with H∞ state feedback under random packet dropouts. The sufficient robust stable conditions are derived via the Lyapunov stability theory and linear matrix inequality approach. Simulations illustrate the effectiveness of the presented method.

  7. Tracking multiple sediment cascades at the river network scale identifies controls and emerging patterns of sediment connectivity

    Science.gov (United States)

    Schmitt, Rafael J. P.; Bizzi, Simone; Castelletti, Andrea

    2016-05-01

    Sediment connectivity in fluvial networks results from the transfer of sediment between multiple sources and sinks. Connectivity scales differently between all sources and sinks as a function of distance, source grain size and sediment supply, network topology and topography, and hydrologic forcing. In this paper, we address the challenge of quantifying sediment connectivity and its controls at the network scale. We expand the concept of a single, catchment-scale sediment cascade toward representing sediment transport from each source as a suite of individual cascading processes. We implement this approach in the herein presented CAtchment Sediment Connectivity And DElivery (CASCADE) modeling framework. In CASCADE, each sediment cascade establishes connectivity between a specific source and its multiple sinks. From a source perspective, the fate of sediment is controlled by its detachment and downstream transport capacity, resulting in a specific trajectory of transfer and deposition. From a sink perspective, the assemblage of incoming cascades defines provenance, sorting, and magnitude of sediment deliveries. At the network scale, this information reveals emerging patterns of connectivity and the location of bottlenecks, where disconnectivity occurs. In this paper, we apply CASCADE to quantitatively analyze the sediment connectivity of a major river system in SE Asia. The approach provides a screening model that can support analyses of large, poorly monitored river systems. We test the sensitivity of CASCADE to various parameters and identify the distribution of energy between the multiple, simultaneously active sediment cascades as key control behind network sediment connectivity. To conclude, CASCADE enables a quantitative, spatially explicit analysis of network sediment connectivity with potential applications in both river science and management.

  8. Separation control using synthetic vortex generator jets in axial compressor cascade

    Institute of Scientific and Technical Information of China (English)

    Xinqian Zheng; Sheng Zhou; Anping Hou; Zhengli Jiang; Daijun Ling

    2006-01-01

    An experimental investigation conducted in a high-speed plane cascade wind tunnel demonstrates that unsteady flow control by using synthetic(zero mass flux)vortex generator jets can effectively improve the aerodynamic performances and reduce(or eliminate) flow separation in axial compressor cascade.The Mach number of the incoming flow is up to 0.7 and most tested cases are at Ma=0.3.The incidence is 10° at which the boundary layer is separated from 70% of the chord length.The roles of excitation frequency,amplitude,location and pitch angle are investigated.Preliminary results show that the excitation amplitude plays a very important role.The optimal excitation location is just upstream of the separation point,and the optimal pitch angle is 35°.The maximum relative reduction of loss coefficient is 22.8%.

  9. A cascade of morphogenic signaling initiated by the meninges controls corpus callosum formation.

    Science.gov (United States)

    Choe, Youngshik; Siegenthaler, Julie A; Pleasure, Samuel J

    2012-02-23

    The corpus callosum is the most prominent commissural connection between the cortical hemispheres, and numerous neurodevelopmental disorders are associated with callosal agenesis. By using mice either with meningeal overgrowth or selective loss of meninges, we have identified a cascade of morphogenic signals initiated by the meninges that regulates corpus callosum development. The meninges produce BMP7, an inhibitor of callosal axon outgrowth. This activity is overcome by the induction of expression of Wnt3 by the callosal pathfinding neurons, which antagonize the inhibitory effects of BMP7. Wnt3 expression in the cingulate callosal pathfinding axons is developmentally regulated by another BMP family member, GDF5, which is produced by the adjacent Cajal-Retzius neurons and turns on before outgrowth of the callosal axons. The effects of GDF5 are in turn under the control of a soluble GDF5 inhibitor, Dan, made by the meninges. Thus, the meninges and medial neocortex use a cascade of signals to regulate corpus callosum development.

  10. Robust cascade control for the horizontal motion of a vehicle with single-wheel actuators

    Science.gov (United States)

    Moseberg, Jan-Erik; Roppenecker, Günter

    2015-12-01

    The article presents a cascade control for the horizontal motion of a vehicle with single-wheel actuators. The outer control loop for the longitudinal and lateral accelerations and the yaw rate ensures a desired vehicle motion. By a combination of state feedback control and observer-based disturbance feedforward the inner control loop robustly stabilises the rotating and steering motions of the wheels in spite of unknown frictions between tyres and ground. Since the three degrees of freedom of the horizontal motion are affected by eight tyre forces, the vehicle considered is an over-actuated system. Thus additional control objectives can be realised besides the desired motion trajectory as, for example, a maximum in driving safety. The corresponding analytical tyre force allocation also guarantees real-time capability because of its relatively low computational effort. Provided suitable fault detection and isolation are available, the proposed cascade control has the potential of fault-tolerance, because the force allocation is adaptable. Another benefit results from the modular control structure, because it allows a stepwise implementation. Besides, it only requires a small number of measurements for control purposes. These measurements are the rotational speeds and steering angles of the wheels, the longitudinal and lateral acceleration and the yaw rate of the vehicle.

  11. Satellite cascade attitude control via fuzzy PD controller with active force control under momentum dumping

    Science.gov (United States)

    Ismail, Z.; Varatharajoo, R.

    2016-10-01

    In this paper, fuzzy proportional-derivative (PD) controller with active force control (AFC) scheme is studied and employed in the satellite attitude control system equipped with reaction wheels. The momentum dumping is enabled via proportional integral (PI) controller as the system is impractical without momentum dumping control. The attitude controllers are developed together with their governing equations and evaluated through numerical treatment with respect to a reference satellite mission. From the results, it is evident that the three axis attitudes accuracies can be improved up to ±0.001 degree through the fuzzy PD controller with AFC scheme for the attitude control. In addition, the three-axis wheel angular momentums are well maintained during the attitude control tasks.

  12. Multi Agent System Based Process Control in Wide Area Protection against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun;

    2013-01-01

    In order to prevent long term voltage instability induced cascading events; a multi agent system (MAS) based wide area protection strategy is proposed in this paper. Due to some unexpected failures of control strategy execution or the consequent unexpected disturbance, the power system will face...... emergent states, but also those unusual control process variations when unexpected situation is experienced. A hybrid simulation platform based on MATLAB/LabVIEW and real time digital simulator (RTDS) is set up to simulate a voltage collapse case in the power system of Eastern Denmark and demonstrate...

  13. Modelling and Extremum Seeking Control of a Cascade of Two Anaerobic Bioreactors

    Directory of Open Access Journals (Sweden)

    Ivan Simeonov

    2011-05-01

    Full Text Available The principle of extremum seeking control has been applied on a cascade of two anaerobic bioreactors using the dilution rate as control action and the biogas flow rates as measured outputs to be maximized. In all cases maximum biogas flow rate with sensible decrease of the general output depollution parameter (compared to the case of one single bioreactor has been obtained, starting from different initial conditions. With the same algorithm, good performances have been obtained in the presence of variations of the inlet organics. Its implication for biotechnology may result in substantial economic benefits.

  14. Multiagent System-Based Wide-Area Protection and Control Scheme against Cascading Events

    DEFF Research Database (Denmark)

    Liu, Zhou; Chen, Zhe; Sun, Haishun

    2015-01-01

    In this paper, a multi agent system (MAS) based wide area protection and control scheme is proposed to deal with the long term voltage instability induced cascading trips. Based on sensitivity analysis between the relay operation margin and power system state variables, an optimal emergency control...... strategy. A hybrid simulation platform based on LabVIEW and real time digital simulator (RTDS) is set up to simulate a blackout case in the power system of Eastern Denmark and to demonstrate the effectiveness of the proposed MAS based protection strategy....

  15. Postural Control During Cascade Ball Juggling: Effects of Expertise and Base of Support.

    Science.gov (United States)

    Rodrigues, Sérgio T; Polastri, Paula F; Gotardi, Gisele C; Aguiar, Stefane A; Mesaros, Marcelo R; Pestana, Mayara B; Barbieri, Fabio A

    2016-08-01

    Cascade ball juggling is a complex perceptual motor skill which requires efficient postural stabilization. The aim of this study was to investigate effects of experience (expert and intermediate groups) and foot distance (wide and narrow stances) on body sway of jugglers during three ball cascade juggling. A total of 10 expert jugglers and 11 intermediate jugglers participated in this study. Participants stood barefoot on the force plate (some participants wore a gaze tracking system), with feet maintained in wide and narrow conditions and performed three 40-seconds trials of the three-ball juggling task. Dependent variables were sway mean velocity, amplitude, mean frequency, number of ball cycles, fixation number, mean duration and its variability, and area of gaze displacement. Two-way analyses of variance with factors for group and condition were conducted. Experts' body sway was characterized by lower velocity and smaller amplitude as compared to intermediate group. Interestingly, the more challenging (narrow) basis of support caused significant attenuation in body sway only for the intermediate group. These data suggest that expertise in cascade juggling was associated with refined postural control.

  16. Coupled-disturbance-observer-based position tracking control for a cascade electro-hydraulic system.

    Science.gov (United States)

    Guo, Qing; Yin, Jing-Min; Yu, Tian; Jiang, Dan

    2017-05-01

    The disturbance suppression is one of the most common control problems in electro-hydraulic systems. especially largely an unknown disturbance often obviously degrades the dynamic performance by biasing the desired actuator outputs (e.g., load forces or torques). In order to reject the dynamic disturbances in some multi-degree-of-freedom manipulators driven by electro-hydraulic actuators, this paper proposes a state feedback control of the cascade electro-hydraulic system based on a coupled disturbance observer with backstepping. The coupled disturbance observer is designed to estimate both the independent element and the coupled element of the external loads on each electro-hydraulic actuator. The cascade controller has the ability to compensate for the disturbance estimating, as well as guarantees the system state error convergence to a prescribed steady state level. The effectiveness of the proposed controller for the suppression of largely unknown disturbances has been demonstrated by comparative study, which implies the proposed approach can achieve better dynamic performance on the motion control of Two-Degree-of-Freedom robotic arm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Infinite Queue Management via Cascade Control for Industrial Routers in Smart Grid IP Networks

    Directory of Open Access Journals (Sweden)

    Ku-Hwan Kim

    2016-01-01

    Full Text Available Smart grid applications experience an extremely wide range of communication delay. Data flows of those applications are normally aggregated at industrial network routers in substations, form infinite (long queues termed bufferbloat issue, and might damage the operation of transmission control protocol. The default queue management scheme, DropTail, in such routers just drops packets if queue is full while the others in literature are mostly based on one-loop feedback control where an optimal point of performance between queue length and drop rate is limited. In this paper, we study the problem of managing a long queue of industrial router at substation under heterogeneous smart grid networks. Specifically, we propose an enqueue-dequeue dropping cascade control using a two-loop design method to control both window size and queue length. Moreover, our proposal can be easily implemented into router firmware with provided discrete expressions. Finally, our simulation results are presented to validate the possible benefits that can be gained from cascade control and compare the existing queue management methods as well.

  18. [Metabolic control of seed germination].

    Science.gov (United States)

    Catusse, Julie; Strub, Jean-Marc; Job, Claudette; Van Dorsselaer, Alain; Job, Dominique

    2008-01-01

    We have used proteomics to better characterize germination and early seedling vigor in sugarbeet. Our strategy includes (1) construction of proteome reference maps for dry and germinating seeds of a high-vigor reference seed lot; (2) investigation of the specific tissue accumulation of proteins (root, cotyledon, perisperm); (3) investigation of changes in protein expression profiles detected in the reference seed lot subjected to different vigor-modifying treatments, e.g. aging and/or priming. More than 1 000 sugarbeet seed proteins have been identified by LC/MS-MS mass spectrometry (albumins, globulins and glutelins have been analyzed separately). Due to the conservation of protein sequences and the quality of MS sequencing (more than 10 000 peptide sequences have been obtained), the success rate of protein identification was on the average of 80%. This is to our knowledge the best detailed proteome analysis ever carried out in seeds. The data allowed us to build a detailed metabolic chart of the sugarbeet seed, generating new insights into the molecular mechanisms determining the development of a new seedling. Also, the proteome of a seed-storage tissue as the perisperm is described for the first time.

  19. Global robust output regulation control for cascaded nonlinear systems using the internal model principle

    Science.gov (United States)

    Yu, Jiang-Bo; Zhao, Yan; Wu, Yu-Qiang

    2014-04-01

    This article considers the global robust output regulation problem via output feedback for a class of cascaded nonlinear systems with input-to-state stable inverse dynamics. The system uncertainties depend not only on the measured output but also all the unmeasurable states. By introducing an internal model, the output regulation problem is converted into a stabilisation problem for an appropriately augmented system. The designed dynamic controller could achieve the global asymptotic tracking control for a class of time-varying reference signals for the system output while keeping all other closed-loop signals bounded. It is of interest to note that the developed control approach can be applied to the speed tracking control of the fan speed control system. The simulation results demonstrate its effectiveness.

  20. Cell biology. Metabolic control of cell death.

    Science.gov (United States)

    Green, Douglas R; Galluzzi, Lorenzo; Kroemer, Guido

    2014-09-19

    Beyond their contribution to basic metabolism, the major cellular organelles, in particular mitochondria, can determine whether cells respond to stress in an adaptive or suicidal manner. Thus, mitochondria can continuously adapt their shape to changing bioenergetic demands as they are subjected to quality control by autophagy, or they can undergo a lethal permeabilization process that initiates apoptosis. Along similar lines, multiple proteins involved in metabolic circuitries, including oxidative phosphorylation and transport of metabolites across membranes, may participate in the regulated or catastrophic dismantling of organelles. Many factors that were initially characterized as cell death regulators are now known to physically or functionally interact with metabolic enzymes. Thus, several metabolic cues regulate the propensity of cells to activate self-destructive programs, in part by acting on nutrient sensors. This suggests the existence of "metabolic checkpoints" that dictate cell fate in response to metabolic fluctuations. Here, we discuss recent insights into the intersection between metabolism and cell death regulation that have major implications for the comprehension and manipulation of unwarranted cell loss.

  1. Experimental and numerical investigation of second-generation, controlled-diffusion, compressor blades in cascade.

    OpenAIRE

    Grove, Darren V.

    1997-01-01

    Approved for public release; distribution is unlimited This thesis contains a detailed experimental and numerical investigation of second-generation, controlled-diffusion, compressor-stator blades at an off-design inlet-flow angle of 39%5c Investigation of the blades took place in a low-speed cascade wind tunnel using various experimental procedures. The objective of the wind tunnel study was to characterize the flow field in and around the blades at the off-design angle, and to investigat...

  2. Stabilization of ODE-Schrodinger cascaded systems subject to boundary control matched disturbance

    Directory of Open Access Journals (Sweden)

    Ya-Ping Guo

    2015-09-01

    Full Text Available In this article, we consider the state feedback stabilization of ODE-Schrodinger cascaded systems with the external disturbance. We use the backstepping transformation to handle the unstable part of the ODE, then design a feedback control which is used to cope with the disturbance and stabilize the Schrodinger part. By active disturbance rejection control (ADRC approach, the disturbance is estimated by a constant high gain estimator, then the feedback control law can be designed. Next, we show that the resulting closed-loop system is practical stable, where the peaking value appears in the initial stage and the stabilized result requires that the derivative of disturbance be uniformly bounded. To avoid the peak phenomenon and to relax the restriction on the disturbance, a time varying high gain estimator is presented and asymptotical stabilization of the corresponding closed-loop system is proved. Finally, the effectiveness of the proposed control is verified by numerical simulations.

  3. Observer-Based Robust Tracking Control for a Class of Switched Nonlinear Cascade Systems

    Directory of Open Access Journals (Sweden)

    Ben Niu

    2013-01-01

    Full Text Available This paper is devoted to robust output feedback tracking control design for a class of switched nonlinear cascade systems. The main goal is to ensure the global input-to-state stable (ISS property of the tracking error nonlinear dynamics with respect to the unknown structural system uncertainties and external disturbances. First, a nonlinear observer is constructed through state transformation to reconstruct the unavailable states, where only one parameter should be determined. Then, by virtue of the nonlinear sliding mode control (SMC, a discontinuous nonlinear output feedback controller is designed using a backstepping like design procedure to ensure the ISS property. Finally, an example is provided to show the effectiveness of the proposed approach.

  4. H-infinity control for cascade minimum-phase switched nonlinear systems

    Institute of Scientific and Technical Information of China (English)

    Shengzhi ZHAO; Jun ZHAO

    2005-01-01

    This paper is concerned with the H-infinity control problem for a class of cascade switched nonlinear systems.Each switched system in this class is composed of a zero-input asymptotically stable nonlinear part,which is also a switched system,and a linearizable part which is controllable.Conditions under which the H-infinity control problem is solvable under arbitrary switching law and under some designed switching law are derived respectively.The nonlinear state feedback and switching law are designed.We exploit the structural characteristics of the switched nonlinear systems to construct common Lyapunov functions for arbitrary switching and to find a single Lyapunov function for designed switching law.The proposed methods do not rely on the solutions of Hamilton-Jacobi inequalities.

  5. Asymptotic regulation of cascade systems with unknown control directions and nonlinear parameterization

    Institute of Scientific and Technical Information of China (English)

    Qiangde WANG; Chunling WEI; Yuqiang WU

    2009-01-01

    A robust partial-state feedback asymptotic regulating control scheme is developed for a class of cascade systems with both nonlinear uncertainties and unknown control directions.A parameter separation technique is introduced to separate the time-varying uncertainty and the unmeasurable state from nonlinear functions.Then,the Nussbaum-type gain method together with the idea of changing supply functions is adopted in the design of a smooth partial-state regulator that can ensure all the signals of the closed-loop system are globally uniformly bounded.Especially,the system state asymptotically converges to zero.The design procedure is illustrated through an example and the simulation results show that the controller is feasible and effective.

  6. Metabolic gene polymorphism frequencies in control populations

    DEFF Research Database (Denmark)

    Garte, Seymour; Gaspari, Laura; Alexandrie, Anna-Karin

    2001-01-01

    Using the International Project on Genetic Susceptibility to Environmental Carcinogens (GSEC) database containing information on over 15,000 control (noncancer) subjects, the allele and genotype frequencies for many of the more commonly studied metabolic genes (CYP1A1, CYP2E1, CYP2D6, GSTM1, GSTT...

  7. Numerical Investigation of Flow Separation Control on a Highly Loaded Compressor Cascade by Plasma Aerodynamic Actuation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xiaohu; LI Yinghong; WU Yun; ZHU Tao; LI Yiwen

    2012-01-01

    To discover the characteristic of separated flows and mechanism of plasma flow control on a highly loaded compressor cascade,numerical investigation is conducted.The simulation method is validated by oil flow visualization and pressure distribution.The loss coefficients,streamline patterns,and topology structure as well as vortex structure are analyzed.Results show thai the numbers of singular points increase and three pairs of additional singular points of topology structure on solid surface generate with the increase of angle of attack,and the total pressure loss increases greatly.There are several principal vortices inside the cascade passage.The pressure side leg of horse-shoe vortex coexists within a specific region together with passage vortex,but finally merges into the latter.Comer vortex exists independently and does not evolve from the suction side leg of horse-shoe vortex.One pair of radial coupling-vortex exists near blade trailing edge and becomes the main part of backflow on the suction surface.Passage vortex interacts with the concentrated shedding vortex and they evolve into a large-scale vortex rotating in the direction opposite to passage vortex.The singular points and separation lines represent the basic separation feature of cascade passage.Plasma actuation has better effect at low freestream velocity,and the relative reductions of pitch-averaged total pressure loss coefficient with different actuation layouts of five and two pairs of electrodes are up to 30.8% and 26.7% while the angle of attack is 2°.Plasma actuation changes the local topology structure,but does not change the number relation of singular points.One pair of additional singular point of topology structure generates with plasma actuation and one more reattachment line appears,both of which break the separation line on the suction surface.

  8. Cascade Probability Control to Mitigate Bufferbloat under Multiple Real-World TCP Stacks

    Directory of Open Access Journals (Sweden)

    Hoang-Linh To

    2015-01-01

    Full Text Available Persistently full buffer problem, commonly known as bufferbloat, causes unnecessary additional latency and throughput degradation whenever congestion happens in Internet. Several proposed queue management schemes, with the debloat mission, are almost based on the modification of one-loop feedback control where the instability and bad transient behavior are still big challenges. In this paper, we present a cascade probability control scheme using margin optimal method to address such challenges under different kinds of real-world TCP stacks. Simulation results guarantee the measured round trip time tracking to a low value of delay (e.g., ≈180 ms under TCP Reno, and ≈130 ms under TCP Cubic and ≈50% delay reduction in comparison to current deployed queue management schemes in network devices.

  9. Short pulse generation and mode control of broadband terahertz quantum cascade lasers

    CERN Document Server

    Bachmann, Dominic; Süess, Martin J; Beck, Mattias; Unterrainer, Karl; Darmo, Juraj; Faist, Jérôme; Scalari, Giacomo

    2016-01-01

    We report on a waveguide engineering technique that enables the generation of a bandwidth up to 1 THz and record ultra-short pulse length of 2.5 ps in injection seeded terahertz quantum cascade lasers. The reported technique is able to control and fully suppress higher order lateral modes in broadband terahertz quantum cascade lasers by introducing side-absorbers to metal-metal waveguides. The side-absorbers consist of a top metalization set-back with respect to the laser ridge and an additional lossy metal layer. In continuous wave operation the side-absorbers lead to octave spanning laser emission, ranging from 1.63 to 3.37 THz, exhibiting a 725 GHz wide at top within a 10 dB intensity range as well as frequency comb operation with a bandwidth of 442 GHz. Numerical and experimental studies have been performed to optimize the impact of the side-absorbers on the emission properties and to determine the required increase of waveguide losses. Furthermore, these studies have led to a better understanding of the ...

  10. Experimental study on cascaded attitude angle control of a multi-rotor unmanned aerial vehicle with the simple internal model control method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jun Beom [Dept. of Aviation Maintenance, Dongwon Institute of Science and Technology, Yangsan (Korea, Republic of); Byun, Young Seop; Jeong, Jin Seok; Kim, Jeong; Kang, Beom Soo [Dept. of Aerospace Engineering, Pusan National University, Busan (Korea, Republic of)

    2016-11-15

    This paper proposes a cascaded control structure and a method of practical application for attitude control of a multi-rotor Unmanned aerial vehicle (UAV). The cascade control, which has tighter control capability than a single-loop control, is rarely used in attitude control of a multi-rotor UAV due to the input-output relation, which is no longer simply a set-point to Euler angle response transfer function of a single-loop PID control, but there are multiply measured signals and interactive control loops that increase the complexity of evaluation in conventional way of design. However, it is proposed in this research a method that can optimize a cascade control with a primary and secondary loops and a PID controller for each loop. An investigation of currently available PID-tuning methods lead to selection of the Simple internal model control (SIMC) method, which is based on the Internal model control (IMC) and direct-synthesis method. Through the analysis and experiments, this research proposes a systematic procedure to implement a cascaded attitude controller, which includes the flight test, system identification and SIMC-based PID-tuning. The proposed method was validated successfully from multiple applications where the application to roll axis lead to a PID-PID cascade control, but the application to yaw axis lead to that of PID-PI.

  11. Modelling and control of broadband traffic using multiplicative multifractal cascades

    Indian Academy of Sciences (India)

    P Murali Krishna; Vikram M Gadre; Uday B Desai

    2002-12-01

    We present the results on the modelling and synthesis of broadband traffic processes namely ethernet inter-arrival times using the VVGM (variable variance gaussian multiplier) multiplicative multifractal model. This model is shown to be more appropriate for modelling network traffic which possess time varying scaling/self-similarity and burstiness. The model gives a simple and efficient technique to synthesise Ethernet inter-arrival times. The results of the detailed statistical and multifractal analysis performed on the original and the synthesised traces are presented and the performance is compared with other models in the literature, such as the Poisson process, and the Multifractal Wavelet Model (MWM) process. It is also shown empirically that a single server queue preserves the multifractal character of the process by analysing its inter-departure process when fed with the multifractal traces. The result of the existence of a global-scaling exponent for multifractal cascades and its application in queueing theory are discussed. We propose tracking and control algorithms for controlling network congestion with bursty traffic modelled by multifractal cascade processes, characterised by the Holder exponents, the value of which at an interval indicates the burstiness in the traffic at that point. This value has to be estimated and used for the estimation of the congestion and predictive control of the traffic in broadband networks. The estimation can be done by employing wavelet transforms and a Kalman filter based predictor for predicting the burstiness of the traffic.

  12. Structurally Controlled Geothermal Systems in the Central Cascades Arc-Backarc Regime, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    Wannamaker, Philip E. [Univ. of Utah, Salt Lake City, UT (United States). Energy and Geoscience Inst. (EGI)

    2016-07-31

    The goal of this project has been to analyze available magnetotelluric (MT) geophysical surveys, structural geology based on mapping and LiDAR, and fluid geochemical data, to identify high-temperature fluid upwellings, critically stressed rock volumes, and other evidence of structurally-controlled geothermal resources. Data were to be integrated to create conceptual models of volcanic-hosted geothermal resources along the Central Cascades arc segment, especially in the vicinity of Mt. Jefferson to Three Sisters. LiDAR data sets available at Oregon State University (OSU) allowed detailed structural geology modeling through forest canopy. Copious spring and well fluid chemistries, including isotopes, were modeled using Geo-T and TOUGHREACT software.

  13. Energy Storage System Based on Cascaded Multilevel Inverter with Decoupled Energy Balancing Control

    Directory of Open Access Journals (Sweden)

    Cao Yuanzhi

    2015-01-01

    Full Text Available This paper presents a three phase cascaded multilevel inverter based supercapacitor (SC energy storage system with novel structure and control strategy to maintain the energy balance of between phases. Every two phases are coupled with a series LC filter. With the filter, SC cells in different phases could exchange energy with an auxiliary power flow at high frequency. The auxiliary power flow is orthogonal to the primary power flow. The phase difference between high frequency voltage and current components of each phase determines whether the energy is absorbed into or released from its SC cells. Unlike traditional energy balancing strategies, the proposed method is independent to the fundamental real power drawn by the energy storage system. Simulation results confirmed the effects of proposed theories.

  14. Controllable nonlocal behaviour by cascaded second-harmonic generation of fs pulses

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw

    2008-01-01

    Second-harmonic generation (SHG) of ultra-short pulses can act as a prototypical nonlocal nonlinear model, since the strength and nature of the temporal nonlocality can be controlled through the phase-mismatch parameter. The presence of a group-velocity mismatch namely implies that when the phase...... compression to few-cycle pulses in the cascaded quadratic soliton compressor, the spectral content of the full coupled SHG model is predicted by the nonlocal model even when few-cycle pulses are interacting....... mismatch is small the nonlocal response function becomes oscillatory, while for large phase mismatch it becomes localized. In the transition between the two regimes the strength of the nonlocality diverges, and the system goes from a weakly nonlocal to a strongly nonlocal state. When simulating soliton...

  15. Role of metabolic control on diabetic nephropathy

    Directory of Open Access Journals (Sweden)

    Macedo Célia Sperandéo

    2002-01-01

    Full Text Available OBJECTIVE: The aim of this investigation was studying the influence of glucose metabolic control on diabetic nephropathy. The authors observed the effect of acarbose, insulin, and both drugs on the metabolic control and development of mesangial enlargement of kidney glomeruli in alloxan-diabetic rats. METHODS: Five groups of Wistar rats were used: normal rats (N, non-treated alloxan-diabetic rats (D, alloxan-diabetic rats treated with acarbose (AD, alloxan-diabetic rats treated with insulin (ID, and alloxan-diabetic rats treated with insulin plus acarbose (IAD. The following parameters were evaluated: body weight; water and food intake; diuresis; blood and urine glucose levels; and the kidney lesions: mesangial enlargement and tubule cell vacuolization. Renal lesions were analysed using a semi-quantitative score 1, 3, 6, 9, and 12 months after diabetes induction. RESULTS: Diabetic rats showed a marked increase of glycemia, urinary glucose levels, diuresis, water and food intake, and weight loss, while the treated diabetic rats showed significant decreased levels of these parameters. The most satisfactory metabolic control was that of diabetic rats treated with acarbose + insulin. There was a significant mesangial enlargement in diabetic rats compared to normal rats from the third up to the 12th month after diabetes induction, with a significant difference between the animals treated with acarbose + insulin and non-treated diabetic rats. A difference between the animals treated with acarbose or insulin alone and non-treated diabetics rats was not seen. CONCLUSIONS: The authors discuss the results stressing the role of diabetic metabolic control in the prevention of diabetic nephropathy.

  16. Passive rGE or Developmental Gene-Environment Cascade? An Investigation of the Role of Xenobiotic Metabolism Genes in the Association Between Smoke Exposure During Pregnancy and Child Birth Weight.

    Science.gov (United States)

    Marceau, Kristine; Palmer, Rohan H C; Neiderhiser, Jenae M; Smith, Taylor F; McGeary, John E; Knopik, Valerie S

    2016-05-01

    There is considerable evidence that smoke exposure during pregnancy (SDP) environmentally influences birth weight after controlling for genetic influences and maternal characteristics. However, maternal smoking during pregnancy-the behavior that leads to smoke exposure during pregnancy-is also genetically-influenced, indicating the potential role of passive gene-environment correlation. An alternative to passive gene-SDP correlation is a cascading effect whereby maternal and child genetic influences are causally linked to prenatal exposures, which then have an 'environmental' effect on the development of the child's biology and behavior. We describe and demonstrate a conceptual framework for disentangling passive rGE from this cascading GE effect using a systems-based polygenic scoring approach comprised of genes shown to be important in the xenobiotic (substances foreign to the body) metabolism pathway. Data were drawn from 5044 families from the Avon Longitudinal Study of Parents and Children with information on maternal SDP, birth weight, and genetic polymorphisms in the xenobiotic pathway. Within a k-fold cross-validation approach (k = 5), we created weighted maternal and child polygenic scores using 18 polymorphisms from 10 genes that have been implicated in the xenobiotic metabolism pathway. Mothers and children shared variation in xenobiotic metabolism genes. Amongst mothers who smoked during pregnancy, neither maternal nor child xenobiotic metabolism polygenic scores were associated with a higher likelihood of smoke exposure during pregnancy, or the severity of smoke exposure during pregnancy (and therefore, neither proposed mechanism was supported), or with child birth weight. SDP was consistently associated with lower child birth weight controlling for the polygenic scores, maternal educational attainment, social class, psychiatric problems, and age. Limitations of the study design and the potential of the framework using other designs are discussed.

  17. A new cascaded control strategy for paralleled line-interactive UPS with LCL filter

    Science.gov (United States)

    Zhang, X. Y.; Zhang, X. H.; Li, L.; Luo, F.; Zhang, Y. S.

    2016-08-01

    Traditional uninterrupted power supply (UPS) is difficult to meet the output voltage quality and grid-side power quality requirements at the same time, and usually has some disadvantage, such as multi-stage conversion, complex structure, or harmonic current pollution to the utility grid and so on. A three-phase three-level paralleled line-interactive UPS with LCL filter is presented in this paper. It can achieve the output voltage quality and grid-side power quality control simultaneously with only single-conversion power stage, but the multi-objective control strategy design is difficult. Based on the detailed analysis of the circuit structure and operation mechanism, a new cascaded control strategy for the power, voltage, and current is proposed. An outer current control loop based on the resonant control theory is designed to ensure the grid-side power quality. An inner voltage control loop based on the capacitance voltage and capacitance current feedback is designed to ensure the output voltage quality and avoid the resonance peak of the LCL filter. Improved repetitive controller is added to reduce the distortion of the output voltage. The setting of the controller parameters is detailed discussed. A 100kVA UPS prototype is built and experiments under the unbalanced resistive load and nonlinear load are carried out. Theoretical analysis and experimental results show the effectiveness of the control strategy. The paralleled line-interactive UPS can not only remain constant three-phase balanced output voltage, but also has the comprehensive power quality management functions with three-phase balanced grid active power input, low THD of output voltage and grid current, and reactive power compensation. The UPS is a green friendly load to the utility.

  18. Lethal control of an apex predator has unintended cascading effects on forest mammal assemblages.

    Science.gov (United States)

    Colman, N J; Gordon, C E; Crowther, M S; Letnic, M

    2014-05-07

    Disruption to species-interaction networks caused by irruptions of herbivores and mesopredators following extirpation of apex predators is a global driver of ecosystem reorganization and biodiversity loss. Most studies of apex predators' ecological roles focus on effects arising from their interactions with herbivores or mesopredators in isolation, but rarely consider how the effects of herbivores and mesopredators interact. Here, we provide evidence that multiple cascade pathways induced by lethal control of an apex predator, the dingo, drive unintended shifts in forest ecosystem structure. We compared mammal assemblages and understorey structure at seven sites in southern Australia. Each site comprised an area where dingoes were poisoned and an area without control. The effects of dingo control on mammals scaled with body size. Activity of herbivorous macropods, arboreal mammals and a mesopredator, the red fox, were greater, but understorey vegetation sparser and abundances of small mammals lower, where dingoes were controlled. Structural equation modelling suggested that both predation by foxes and depletion of understorey vegetation by macropods were related to small mammal decline at poisoned sites. Our study suggests that apex predators' suppressive effects on herbivores and mesopredators occur simultaneously and should be considered in tandem in order to appreciate the extent of apex predators' indirect effects.

  19. An investigation of controls on chemical weathering in the Cascade Mountains of Oregon

    Science.gov (United States)

    Pett-Ridge, J. C.; Kleber, M.

    2011-12-01

    The steep volcanic terrain on the wet western side of the Cascade Range is likely to support relatively fast chemical weathering rates. In this study we present preliminary data from an investigation of weathering in the H. J. Andrews Experimental Forest, located in the central western Oregon Cascades. The H. J. Andrews Experimental Forest has long been the focus of watershed biogeochemistry and ecosystem studies. Within the forest, 7 small watersheds are gauged, with discharge, stream chemistry, and sediment flux records extending from 1968 to the present. Prior work at this site has focused on understanding the system response to timber harvest, fire, and road-building disturbance. The 6400 hectare landscape of the Andrews forest has been well-characterized for multiple variables, such as climate, aboveground net primary productivity, hydrologic flowpaths and disturbance regimes. Together with the long-term monitoring of stream fluxes, this provides context for our investigation of the controls on weathering processes and rates. We conducted a paired soil sampling regime in order to examine differences in weathering products based on bedrock type (basalt flow, andesite flow, and propylitically altered tuff and breccia), slope aspect, and elevation, in each case holding other soil forming state factors relatively constant. Soils were sampled by horizon down to bedrock or to ~1.5 m depth, and fully characterized including pH, bulk density, and particle size analysis. Fe, Al, Si, and Mn were analyzed on selective wet chemical extraction procedures to examine differences between soils in content of amorphous and crystalline Fe-oxides, allophane, and organo-mineral complexes. XRD analyses of phyllosilicate clay fractions from the deepest 2 horizons of each profile were also performed. Finally, we present bulk chemistry from total soil digestions, in order to assess the overall degree of chemical denudation from the soil profiles, as a function of elevation, slope

  20. Tight interconnection and multi-level control of Arabidopsis MYB44 in MAPK cascade signalling.

    Science.gov (United States)

    Persak, Helene; Pitzschke, Andrea

    2013-01-01

    Abiotic stress poses a huge, ever-increasing problem to plants and agriculture. The dissection of signalling pathways mediating stress tolerance is a prerequisite to develop more resistant plant species. Mitogen-activated protein kinase (MAPK) cascades are universal signalling modules. In Arabidopsis, the MAPK MPK3 and its upstream regulator MAPK kinase MKK4 initiate the adaptation response to numerous abiotic and biotic stresses. Yet, molecular steps directly linked with MKK4-MPK3 activation are largely unknown. Starting with a yeast-two-hybrid screen for interacting partners of MKK4, we identified a transcription factor, MYB44. MYB44 is controlled at multiple levels by and strongly inter-connected with MAPK signalling. As we had shown earlier, stress-induced expression of the MYB44 gene is regulated by a MPK3-targeted bZIP transcription factor VIP1. At the protein level, MYB44 interacts with MPK3 in vivo. MYB44 is phosphorylated by MPK3 in vitro at a single residue, Ser145. Although replacement of Ser145 by a non-phosphorylatable (S145A) or phosphomimetic (S145D) residue did not alter MYB44 subcellular localisation, dimerization behaviour nor DNA-binding characteristics, abiotic stress tolerance tests in stable transgenic Arabidopsis plants clearly related S145 phosphorylation to MYB44 function: Compared to Arabidopsis wild type plants, MYB44 overexpressing lines exhibit an enhanced tolerance to osmotic stress and are slightly more sensitive to abscisic acid. Interestingly, overexpression of the S145A variant revealed that impaired phosphorylation does not render the MYB44 protein non-functional. Instead, S145A lines are highly sensitive to abiotic stress, and thereby remarkably similar to mpk3-deficient plants. Its in vivo interaction with the nuclear sub-pools of both MPK3 and MKK4 renders MYB44 the first plant transcription factor to have a second function as putative MAPK cascade scaffolding protein.

  1. Active Power and DC-link Voltage Coordinative Control for Cascaded DC-AC Converter with Bidirectional Power Application

    DEFF Research Database (Denmark)

    Tian, Yanjun; Chen, Zhe; Deng, Fujin;

    2015-01-01

    Two stage cascaded converters are widely used in DC/AC hybrid systems to achieve the bidirectional power transmission. The topology of dual active bridge cascaded with inverter (DABCI) is commonly used in this application. This paper proposes a coordinative control method for DABCI and it’s able...... to reduce the DC-link voltage fluctuation between the DAB and inverter, then reduce the stress on the switching devices, as well as improve the system dynamic performance. In the proposed control method, the DAB and inverter are coordinated to control the DC-link voltage and the power......, and this responsibility sharing control can effectively suppress the impact of the power variation on the DC-link voltage, without sacrificing stability. The proposed control method is also effective for DABCI in unidirectional power transmission. The effectiveness of the propose control has been validated by both...

  2. Dual-Electrical-Port Control of Cascaded Doubly-Fed Induction Machine for EV/HEV Applications

    DEFF Research Database (Denmark)

    Han, Peng; Cheng, Ming; Chen, Zhe

    2017-01-01

    This paper presents a dual-electrical-port control scheme for four-quadrant operation of cascaded doubly-fed induction machine (CDFIM), which has conventionally been used as a variable-speed drive or variable-speed constant-frequency generator for limited-speed-range applications. The proposed...

  3. Single-Electrical-Port Control of Cascaded Doubly-Fed Induction Machine for EV/HEV Applications

    DEFF Research Database (Denmark)

    Han, Peng; Cheng, Ming; Chen, Zhe

    2017-01-01

    A single-electrical-port control scheme, for four-quadrant operation of cascaded doubly-fed induction machine (CDFIM), which has long been conceived as a motor or generator only suitable for limited two-quadrant operation, is proposed and theoretically demonstrated. The drive system is configured...

  4. Dual-Electrical-Port Control of Cascaded Brushless Doubly-Fed Induction Drive for EV/HEV Applications

    DEFF Research Database (Denmark)

    Han, Peng; Cheng, Ming; Chen, Zhe

    2016-01-01

    This paper presents a dual-electrical-port control scheme of cascaded brushless doubly-fed induction machine (CBDFIM) for EV/HEV applications aiming at achieving doubled constant torque and constant power regions compared to its singly-fed counterpart with the same equivalent pole pair number...

  5. A study of temperature sensor location based on fractal analysis for cascade control schemes in tubular reactors

    DEFF Research Database (Denmark)

    Eduardo Ramirez-Castelan, Carlos; Moguel-Castañeda, Jazael; Puebla, Hector

    2016-01-01

    Temperature sensor location for cascade control schemes in tubular reactors is still an open research problem. Several studies have pointed out that most temperature sensitive zones along the length of the reactor are suitable to this end. In this work, we have studied the problem of sensor locat...

  6. Transformer less based modified cascaded seven levels H- bridge inverter control of DSTATCOM

    Directory of Open Access Journals (Sweden)

    Ganesh Prasad Reddy,

    2010-11-01

    Full Text Available This paper studies an investigation of Transformer less Based Modified Cascaded Seven-Level (TBMCSL H – bridge Inverter is used in a Distribution Static Compensator (DSTATCOM in Power System (PS, making use of TBMCSL advantages of low harmonics distortion, reduced number of switches and suppressed switching losses. In order to improve the power factor, compensate the reactive power and eliminatethe Total Harmonics Distortion (THD drawn from a Non-Liner Diode Rectifier Load (NLDRL of DSTATCOM, we propose a Sub-Harmonics Pulse Width Modulation (SHPWM technique is used as control for the switches of TBHSL H – bridge Inverter. The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM and Proportional and Integral (PI control is used for capacitors dc voltage regulation for DSTATCOM. A TBMCSL H – bridge Inverter is considered for shunt compensation of a 9 kV distribution system. The results are verified through MatLab/Simulink software package.

  7. Topological analysis of plasma flow control on corner separation in a highly loaded compressor cascade

    Institute of Scientific and Technical Information of China (English)

    Xiao-Hu Zhao; Yun Wu; Ying-Hong Li; Xue-De Wang; Qin Zhao

    2012-01-01

    In this paper,flow behavior and topology structure in a highly loaded compressor cascade with and without plasma aerodynamic actuation (PAA) are investigated.Streamline pattern,total pressure loss coefficient,outlet flow angle and topological analysis are considered to study the effect and mechanism of the plasma flow control on corner separation.Results presented include the boundary layer flow behavior,effects of three types of PAA on separated flows and performance parameters,topology structures and sequences of singular points with and without PAA.Two separation lines,reversed flow and backflow exist on the suction surface.The cross flow on the endwall is an important element for the corner separation.PAA can reduce the undertuming and overturning as well as the total pressure loss,leading to an overall increase of flow turning and enhancement of aerodynamic performance.PAA can change the topology structure,sequences of singular points and their corresponding separation lines.Types Ⅱ and Ⅲ PAA are much more efficient in controlling corner separation and enhancing aerodynamic performances than type Ⅰ.

  8. Bilateral Diabetic Papillopathy and Metabolic Control

    DEFF Research Database (Denmark)

    Ostri, Christoffer; Lund-Andersen, Henrik; Sander, Birgit;

    2010-01-01

    OBJECTIVE: The pathogenesis of diabetic papillopathy largely is unknown, but case reports suggest that it may follow rapidly improved metabolic control. The present study was designed to investigate this hypothesis. DESIGN: Retrospective case-control study. PARTICIPANTS: Two thousand sixty......-six patients with type 1 diabetes. METHODS: Review of clinical, photographic, and clinical chemistry records from a large diabetology and ophthalmology unit between 2001 and 2008. MAIN OUTCOME MEASURES: Simultaneous, bilateral diabetic papillopathy. RESULTS: The mean follow-up was 4.9 years. During 10 020...... patient-years of observation, bilateral diabetic papillopathy developed in 5 patients. During the year preceding this incident, all 5 patients had experienced a decrease in glycosylated hemoglobin A(1c) (HbA(1C)) at a maximum rate of -2.5 (mean) percentage points per quarter year, which was significantly...

  9. Translational control by the DEAD Box RNA helicase belle regulates ecdysone-triggered transcriptional cascades.

    Directory of Open Access Journals (Sweden)

    Robert J Ihry

    Full Text Available Steroid hormones act, through their respective nuclear receptors, to regulate target gene expression. Despite their critical role in development, physiology, and disease, however, it is still unclear how these systemic cues are refined into tissue-specific responses. We identified a mutation in the evolutionarily conserved DEAD box RNA helicase belle/DDX3 that disrupts a subset of responses to the steroid hormone ecdysone during Drosophila melanogaster metamorphosis. We demonstrate that belle directly regulates translation of E74A, an ets transcription factor and critical component of the ecdysone-induced transcriptional cascade. Although E74A mRNA accumulates to abnormally high levels in belle mutant tissues, no E74A protein is detectable, resulting in misregulation of E74A-dependent ecdysone response genes. The accumulation of E74A mRNA in belle mutant salivary glands is a result of auto-regulation, fulfilling a prediction made by Ashburner nearly 40 years ago. In this model, Ashburner postulates that, in addition to regulating secondary response genes, protein products of primary response genes like E74A also inhibit their own ecdysone-induced transcription. Moreover, although ecdysone-triggered transcription of E74A appears to be ubiquitous during metamorphosis, belle-dependent translation of E74A mRNA is spatially restricted. These results demonstrate that translational control plays a critical, and previously unknown, role in refining transcriptional responses to the steroid hormone ecdysone.

  10. CONTROL TECHNIQUES FOR VARIOUS BIPOLAR PWM STRATEGIES OF THREE PHASE FIVE LEVEL CASCADED INVERTER

    Directory of Open Access Journals (Sweden)

    C. R. BALAMURUGAN

    2015-07-01

    Full Text Available This paper presents different types of bipolar Pulse Width Modulation (PWM strategies for the chosen Cascaded MultiLevel Inverter (CMLI. The main purpose of MLI is to use power semiconductor devices of lower voltage ratings to realize high voltage levels at inverter output. Due to their ability to obtain refined output voltage waveforms, reduced Total Harmonic Distortion (THD and reduced EMI problems by reducing the switching dv/dt. In this paper, a three phase CMLI is controlled with Sinusoidal PWM strategy with Phase Disposition PWM (PDPWM, Phase Opposition and Disposition PWM (PODPWM, Alternative Phase Opposition and Disposition PWM (APODPWM, Phase Shift PWM (PSPWM and hybrid modulation strategy and the variation of THD in their outputs are observed by varying the modulation index. Simulations are performed using MATLAB-SIMULINK. It is observed that APODPWM and PSPWM provide output with relatively low distortion. It is also seen that PS, APOD and hybrid PWM are found to perform better since they provide relatively higher fundamental RMS output voltage. From hardware results it is seen that POD PWM provides output with relatively low distortion. It is also observed that PSPWM is found to perform better since it provide relatively higher fundamental RMS output voltage.

  11. Translational control by the DEAD Box RNA helicase belle regulates ecdysone-triggered transcriptional cascades.

    Directory of Open Access Journals (Sweden)

    Robert J Ihry

    Full Text Available Steroid hormones act, through their respective nuclear receptors, to regulate target gene expression. Despite their critical role in development, physiology, and disease, however, it is still unclear how these systemic cues are refined into tissue-specific responses. We identified a mutation in the evolutionarily conserved DEAD box RNA helicase belle/DDX3 that disrupts a subset of responses to the steroid hormone ecdysone during Drosophila melanogaster metamorphosis. We demonstrate that belle directly regulates translation of E74A, an ets transcription factor and critical component of the ecdysone-induced transcriptional cascade. Although E74A mRNA accumulates to abnormally high levels in belle mutant tissues, no E74A protein is detectable, resulting in misregulation of E74A-dependent ecdysone response genes. The accumulation of E74A mRNA in belle mutant salivary glands is a result of auto-regulation, fulfilling a prediction made by Ashburner nearly 40 years ago. In this model, Ashburner postulates that, in addition to regulating secondary response genes, protein products of primary response genes like E74A also inhibit their own ecdysone-induced transcription. Moreover, although ecdysone-triggered transcription of E74A appears to be ubiquitous during metamorphosis, belle-dependent translation of E74A mRNA is spatially restricted. These results demonstrate that translational control plays a critical, and previously unknown, role in refining transcriptional responses to the steroid hormone ecdysone.

  12. Corner Separation Control by Boundary Layer Suction Applied to a Highly Loaded Axial Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Yangwei Liu

    2014-11-01

    Full Text Available Control of corner separation has attracted much interest due to its improvement of performance and energy utilization in turbomachinery. Numerical studies have been performed under both design and off-design flow conditions to investigate the effects of boundary layer suction (BLS on corner separation in a highly loaded compressor cascade. Two new BLS slot configurations are proposed and a total of five suction slot configurations were studied and compared. Averaged static pressure rise, exit loss coefficient, passage blockage and flow turning angle have been given and compared systematically over a range of operation incidence angles. Distributions of significant loss removal, blade loading, exit deviation and total pressure loss at 3 degree and 7 degree incidence have also been studied. Under the same suction mass flows of 0.7% of the inlet mass flows, the pitchwise suction slot on the endwall shows a better optimal performance over the whole operation incidence among single suction slots. By using of the new proposed compound slot configuration with one spanwise slot on the blade suction side and one pitchwise slot on the endwall, the maximum reduction of total pressure loss at 7 degree incidence can be 39.4%.

  13. Multi-Agent System Based Special Protection and Emergency Control Scheme against Cascading Events in Power System

    DEFF Research Database (Denmark)

    Liu, Zhou

    for real time implementation. On the other hand, with the aim of executing the control methods timely and implementing the whole protection strategy suitably, multi-agent system (MAS) with hierarchical structure is designed here. The distributed relays and controllers, which work as device agents......This thesis concerns the development of wide area special protection and emergency control scheme that can provide effective countermeasures against long term voltage instability induced cascading events and blackouts in power system. Most past cascaded blackouts are caused by unexpected backup...... relay operations due to low voltage or overload state in the post stage of N-1 (or N-k) contingency. If such state could be sensed and adjusted appropriately before those relay actions, the system stability might be sustained. So it is of great significance to develop a suitable protection scheme...

  14. Metabolic Control Analysis: Separable Matrices and Interdependence of Control Coefficients.

    Science.gov (United States)

    Elsner; Giersch

    1998-08-21

    A central quantity for the analysis of the interdependence of control coefficients is the Jacobian H of the pathway. For a simple metabolic chain, H is known to be tridiagonal. Its inverse H-1, which is required to calculate control coefficients, is semi-separable. A semi-separable nxn matrix (aij) has the characteristic property that it is decomposable into two triangles for each of which there are vectors r=(r1, . . . ,rn) and t=(t1, . . . ,tn) with aij=ritj. The exact definitions of semi-separability and the related separability of matrices are given in Appendix B. Owing to the semi-separability of H-1, the determinants of all 2x2 sub-matrices of elements located within one of the triangles are zero. Therefore, these triangles are regions of vanishing two-minors. The flux control coefficient matrix CJ is hown to be separable and the concentration control coefficient matrix Cs to be semi separable. Cs has, in addition, the peculiarity that the row vector is the same for both its upper and lower triangle. A feedback loop gives rise to a new sub-region of vanishing two-minors, thereby disturbing the semi-separability of the upper triangle of Cs. A recipe is given to graphically construct the regions of vanishing two-minors of concentration control coefficients. The notion of (semi-)separability allows assessment of all dependences of control coefficients for metabolic pathways.Copyright 1998 Academic Press

  15. Integrated Broadband Quantum Cascade Laser

    Science.gov (United States)

    Mansour, Kamjou (Inventor); Soibel, Alexander (Inventor)

    2016-01-01

    A broadband, integrated quantum cascade laser is disclosed, comprising ridge waveguide quantum cascade lasers formed by applying standard semiconductor process techniques to a monolithic structure of alternating layers of claddings and active region layers. The resulting ridge waveguide quantum cascade lasers may be individually controlled by independent voltage potentials, resulting in control of the overall spectrum of the integrated quantum cascade laser source. Other embodiments are described and claimed.

  16. Action Video Gaming and Cognitive Control: Playing First Person Shooter Games Is Associated with Improved Action Cascading but Not Inhibition.

    Science.gov (United States)

    Steenbergen, Laura; Sellaro, Roberta; Stock, Ann-Kathrin; Beste, Christian; Colzato, Lorenza S

    2015-01-01

    There is a constantly growing interest in developing efficient methods to enhance cognitive functioning and/or to ameliorate cognitive deficits. One particular line of research focuses on the possibly cognitive enhancing effects that action video game (AVG) playing may have on game players. Interestingly, AVGs, especially first person shooter games, require gamers to develop different action control strategies to rapidly react to fast moving visual and auditory stimuli, and to flexibly adapt their behaviour to the ever-changing context. This study investigated whether and to what extent experience with such videogames is associated with enhanced performance on cognitive control tasks that require similar abilities. Experienced action videogame-players (AVGPs) and individuals with little to no videogame experience (NVGPs) performed a stop-change paradigm that provides a relatively well-established diagnostic measure of action cascading and response inhibition. Replicating previous findings, AVGPs showed higher efficiency in response execution, but not improved response inhibition (i.e. inhibitory control), as compared to NVGPs. More importantly, compared to NVGPs, AVGPs showed enhanced action cascading processes when an interruption (stop) and a change towards an alternative response were required simultaneously, as well as when such a change had to occur after the completion of the stop process. Our findings suggest that playing AVGs is associated with enhanced action cascading and multi-component behaviour without affecting inhibitory control.

  17. Action Video Gaming and Cognitive Control: Playing First Person Shooter Games Is Associated with Improved Action Cascading but Not Inhibition.

    Directory of Open Access Journals (Sweden)

    Laura Steenbergen

    Full Text Available There is a constantly growing interest in developing efficient methods to enhance cognitive functioning and/or to ameliorate cognitive deficits. One particular line of research focuses on the possibly cognitive enhancing effects that action video game (AVG playing may have on game players. Interestingly, AVGs, especially first person shooter games, require gamers to develop different action control strategies to rapidly react to fast moving visual and auditory stimuli, and to flexibly adapt their behaviour to the ever-changing context. This study investigated whether and to what extent experience with such videogames is associated with enhanced performance on cognitive control tasks that require similar abilities. Experienced action videogame-players (AVGPs and individuals with little to no videogame experience (NVGPs performed a stop-change paradigm that provides a relatively well-established diagnostic measure of action cascading and response inhibition. Replicating previous findings, AVGPs showed higher efficiency in response execution, but not improved response inhibition (i.e. inhibitory control, as compared to NVGPs. More importantly, compared to NVGPs, AVGPs showed enhanced action cascading processes when an interruption (stop and a change towards an alternative response were required simultaneously, as well as when such a change had to occur after the completion of the stop process. Our findings suggest that playing AVGs is associated with enhanced action cascading and multi-component behaviour without affecting inhibitory control.

  18. Exercising for metabolic control: is timing important?

    Science.gov (United States)

    Haxhi, Jonida; Scotto di Palumbo, Alessandro; Sacchetti, Massimo

    2013-01-01

    Atherosclerosis-related cardiovascular disease and diabetes mellitus are leading causes of mortality in the world and both disorders are closely related to the postprandial phenomena. Regular exercise is being strongly advocated as a precious tool in easing the global burden of chronic disease. Although exercise intensity, duration and frequency are well established in current guidelines for healthy and diabetic individuals, there is still no consensus on the optimal timing of exercise in relation to the last meal. The present paper reviews the existing literature on the 'when?' of aerobic exercise for metabolic control in healthy and diabetic individuals. Effective control of postprandial phenomena might prove to be a useful tool in the prevention of chronic disease. Exercise appears to influence glycemic and triglyceridemic responses differently depending on the meal composition and time lapse from meals. In healthy individuals, fasted-state exercise favors postprandial triglyceridemic control and the insulin sensitivity related to it. However, there is a lack of data on this matter in diabetic patients. On the other hand, when postprandial glycemia is of concern, aerobic exercise works better when performed after a meal, both in healthy and in diabetic patients.

  19. A non-iterative cascaded predictive control approach for control of irrigation canals

    NARCIS (Netherlands)

    Negenborn, R.R.; Sahin, A.; Lukszo, Z.; De Schutter, B.; Morari, M.

    2009-01-01

    Irrigation canals transport water from water sources (such as large rivers and lakes) to water users (such as farmers). Irrigation canals are typically very large in nature, covering vast geographical areas, and involving a significant number of control actuators, such as pumps, gates, and locks. Th

  20. It must be my metabolism: Metabolic control of mind

    Directory of Open Access Journals (Sweden)

    Dana M Small

    2014-07-01

    relationship between the reinforcing potency of sugared solutions and the metabolic effects that follow their consumption (16, also see the abstract of I. de Araujo. We therefore hypothesized that metabolic response provides the critical signal necessary to condition preference. To test this prediction in humans we designed a flavor nutrient conditioning study in which participants first rated their liking for novel flavored beverages and then, over a three week-long conditioning protocol, alternately ingested one of the flavored beverages with 112.5 kcal from maltodextrin, a tasteless and odorless polysaccharide that breaks down into glucose, and another flavored beverage with no calories added. Plasma glucose was measured before and after each of the drinks’ consumption as a proxy measure of metabolic response, assuming that glucose oxidation depends upon the level of circulating glucose. For each participant flavor-calorie pairings were held constant but the identity of the conditioned flavors were counterbalanced across participants. Following the exposure phase, participants’ liking of, and brain responses to, non-caloric versions of the flavors were assessed. We predicted that change in plasma glucose produced by beverage consumption during the exposure sessions would be associated with neural responses in dopamine source and target regions to the calorie predictive flavor. As predicted, response in the ventral striatum and hypothalamus to the calorie-predictive flavor (CS+ vs. non the noncaloric-predictive flavor (CS- was strongly associated with the changes in plasma glucose levels produced by ingestion of these same beverages when consumed previously either with (CS+ or without (CS- calories (17. Specifically, the greater the increase in circulating glucose occurring post ingestion of the beverage containing 112.5 kcal from maltodextrin versus the noncaloric drink, the stronger was the brain response to the CS+ compared to the CS- flavor. Importantly, because each

  1. The real time cascade generalized predictive control and application to a boiler circuit system

    Institute of Scientific and Technical Information of China (English)

    Xu Min; Li Shaoyuan

    2005-01-01

    Boiler-circuit system in a circulating fluidized bed combustion boiler is a complex and typical industrial process with a large lag and time-delay. Conventional PID algorithm can not obtain satisfied performance, especially in the presence of disturbance. A cascade generalized predictivecontrol (CGPC) strategy, is which the inner loop can restrain the disturbance while the outer loop can eliminate the offset, is proposed in this paper. We develop cascade GPC algorithm instead of conventional PID algorithm in the boiler-circuit system. Simulation on experimental boiler-circuit models of circulating fluidized bed combustion boiler shows strong robustness.

  2. Ultra-bright GeV photon source via controlled electromagnetic cascades in laser-dipole waves

    CERN Document Server

    Gonoskov, A; Bastrakov, S; Efimenko, E; Ilderton, A; Kim, A; Marklund, M; Meyerov, I; Muraviev, A; Sergeev, A

    2016-01-01

    One aim of upcoming high-intensity laser facilities is to provide new high-flux gamma-ray sources. Electromagnetic cascades may serve for this, but are known to limit both field strengths and particle energies, restricting efficient production of photons to sub-GeV energies. Here we show how to create a directed GeV photon source, enabled by a controlled interplay between the cascade and anomalous radiative trapping. Using advanced 3D QED particle-in-cell (PIC) simulations and analytic estimates, we show that the concept is feasible for planned peak powers of 10 PW level. A higher peak power of 40 PW can provide $10^9$ photons with GeV energies in a well-collimated 3 fs beam, achieving peak brilliance ${9 \\times 10^{24}}$ ph s$^{-1}$mrad$^{-2}$mm$^{-2}$/0.1${\\%}$BW. Such a source would be a powerful tool for studying fundamental electromagnetic and nuclear processes.

  3. Central nervous system control of triglyceride metabolism

    NARCIS (Netherlands)

    Geerling, Johanna Janetta (Janine)

    2013-01-01

    This thesis describes the role of the brain in the regulation of peripheral triglyceride metabolism, in the context of the metabolic syndrome. Based on various pharmacological studies we described the role of two hormones, insulin and glucagon-like peptide-1, in the production and clearance of

  4. Central nervous system control of triglyceride metabolism

    NARCIS (Netherlands)

    Geerling, Johanna Janetta (Janine)

    2013-01-01

    This thesis describes the role of the brain in the regulation of peripheral triglyceride metabolism, in the context of the metabolic syndrome. Based on various pharmacological studies we described the role of two hormones, insulin and glucagon-like peptide-1, in the production and clearance of trigl

  5. Controlled sumoylation of the mevalonate pathway enzyme HMGS-1 regulates metabolism during aging

    NARCIS (Netherlands)

    Sapir, Amir; Tsur, Assaf; Koorman, Thijs; Ching, Kaitlin; Mishra, Prashant; Bardenheier, Annabelle; Podolsky, Lisa; Bening-Abu-Shach, Ulrike; Boxem, Mike; Chou, Tsui-Fen; Broday, Limor; Sternberg, Paul W

    2014-01-01

    Many metabolic pathways are critically regulated during development and aging but little is known about the molecular mechanisms underlying this regulation. One key metabolic cascade in eukaryotes is the mevalonate pathway. It catalyzes the synthesis of sterol and nonsterol isoprenoids, such as chol

  6. Genetic Algorithm and Particle Swarm Optimization Based Cascade Interval Type 2 Fuzzy PD Controller for Rotary Inverted Pendulum System

    Directory of Open Access Journals (Sweden)

    Mukhtar Fatihu Hamza

    2015-01-01

    function. The performance characteristics considered for the controller are steady state error, settling time, rise time, maximum overshoot, and control energy. Experimental and simulation results indicated that the effectiveness and robustness of the proposed GA- and PSO-based controllers on the RIP with respect to load disturbances, parameter variation, and noise effects have been improved over state-of-the-art method. However, the comparative results for simulation and experiment based on cascade IT2F-PDC indicate that GA-based IT2F-PDC has lower steady state error while PSO-based IT2F-PDC has lower overshoot, settling time, and control energy, but both have almost the same rise time. The proposed control strategy can be regarded as a promising strategy for controlling different unstable and nonlinear systems.

  7. Central nervous system control of triglyceride metabolism

    OpenAIRE

    Geerling, Johanna Janetta (Janine)

    2013-01-01

    This thesis describes the role of the brain in the regulation of peripheral triglyceride metabolism, in the context of the metabolic syndrome. Based on various pharmacological studies we described the role of two hormones, insulin and glucagon-like peptide-1, in the production and clearance of triglycerides. We showed that insulin stimulates the uptake of (triglyceride-derived) fatty acids and that the brain plays an essential role in this process. Additionally, we showed that the glucagon-li...

  8. Knowledge, attitudes and metabolic control of diabetic and cardiac patients

    Directory of Open Access Journals (Sweden)

    Bruna Emy Ono

    2016-01-01

    Full Text Available Objective: to verify the relationship between knowledge, attitudes and metabolic control in diabetic and cardiac patients. Methods: descriptive, exploratory and cross-sectional study exploring the knowledge, attitudes and diabetes metabolic control in 46 participants with heart disease. Results: participants were predominantly male with incomplete secondary education who demonstrated poor knowledge and unfavorable attitudes towards the disease. There was no difference between participants with and without knowledge on variables of metabolic and clinical control of diabetes, neither with respect to attitudes towards the disease. Conclusion: knowledge about diabetes was unsatisfactory in patients with heart disease and unrelated to favorable actions and better disease control.

  9. Accurate torque-sensorless control approach for interior permanent-magnet synchronous machine based on cascaded sliding mode observer

    Directory of Open Access Journals (Sweden)

    Kai-Hui Zhao

    2017-06-01

    Full Text Available To improve the accuracy of torque control for vector control of interior permanent-magnet synchronous machine (IPMSM, this study proposes a torque-sensorless control method based on cascaded sliding mode observer (SMO. First, the active flux model is discussed, which converts the model of IPMSM into the equivalent model of surface-mounted permanent-magnet synchronous machine. Second, to reduce chattering caused by system parameters variations and external disturbances, the cascaded observer is designed, which is composed of a variable gain adaptive SMO and an active flux SMO. The variable gain adaptive SMO is designed to estimate the speed, rotor position and stator resistance in the d–q reference frame. The active flux SMO is designed to estimate the active flux and torque in the α–β reference frame. Global asymptotic stability of the observers is guaranteed by the Lyapunov stability analysis. Finally, simulations and experiments are carried out to verify the effectiveness of the proposed control scheme.

  10. A hybrid cascade control scheme for the VFA and COD regulation in two-stage anaerobic digestion processes.

    Science.gov (United States)

    Méndez-Acosta, H O; Campos-Rodríguez, A; González-Álvarez, V; García-Sandoval, J P; Snell-Castro, R; Latrille, E

    2016-10-01

    A hybrid (continuous-discrete) cascade control is proposed to regulate both, volatile fatty acids (VFA) and chemical oxygen demand (COD) concentrations in two-stage (acidogenic-methanogenic) anaerobic digestion (TSAD) processes. The outer loop is a discrete controller that regulates the COD concentration of the methanogenic bioreactor by using a daily off-line measurement and that modifies the set-point tracked by inner loop, which manipulates the dilution rate to regulate the VFA concentration of the acidogenic bioreactor, estimated by continuous on-line conductivity measurements, avoiding acidification. The experimental validation was conducted in a TSAD process for the treatment of tequila vinasses during 110days. Results showed that the proposed cascade control scheme was able to achieve the VFA and COD regulation by using conventional measurements under different set-point values in spite of adverse common scenarios in full-scale anaerobic digestion processes. Microbial composition analysis showed that the controller also favors the abundance and diversity toward methane production.

  11. Pengaturan Kecepatan Motor DC pada Mobil Listrik Menggunakan Bidirectional Buck-Boost Cascade Converter berbasis Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Muhammad Taufiq Ramadhan

    2015-03-01

    Full Text Available Penggunaan mobil listrik secara umum terkendala pada beban, kecepatan aktual, serta efisiensi energi. Pemanfaatan Fuzzy Logic Controller untuk pengaturan kecepatan motor DC pada mobil listrik diperlukan untuk meraih kecepatan aktual yang lebih presisi  sehingga diperoleh efisiensi energi. Selain itu perlu juga  menggunakan Bidirectional Buck-Boost Cascade Converter untuk pengaturan motor DC secara bidirectional, yakni pengaturan saat motoring dan saat pengereman regeneratif (regenerative braking. Hal ini berdasar pada energi yang terbuang percuma, baik itu rugi elektris maupun rugi mekanis saat pengereman.

  12. Metabolic syndrome in migraine headache: A case-control study

    Directory of Open Access Journals (Sweden)

    Mehrzad Salmasi

    2014-01-01

    Full Text Available Background: The correlation of metabolic syndrome and migraine headache was evaluated in some previous studies. However there is no study that compared the prevalence of metabolic syndrome in the patients with and without migraine. Control of coincidental factors such as metabolic syndrome reduces therapeutic resistance in migrainous patients. The aim of this study was to compare prevalence of metabolic syndrome in patients with and without migraine headache. Materials and Methods: 200 migrainous patients diagnosed according to International Headache Society and 200 healthy controls without migraine enrolled in this study. Metabolic syndrome was diagnosed according to ATP III criteria in these two groups and compared with each other. Results: In this study, 17% (34 of migrainous patients and 15% (30 of healthy control without migraine had metabolic syndrome. (P = 0.585. Of the metabolic syndrome components, body mass index (P = 0.05 and waist circumference in migrainous (P = 0.03 were significantly more frequent. Conclusion: Our results demonstrate that metabolic syndrome and migraine headache had not significant correlation; however, higher body mass index and waist circumference as metabolic syndrome components had correlated with migraine headache.

  13. Path-Controlled Time Reordering of Paired Photons in a Dressed Three-Level Cascade

    Science.gov (United States)

    Bounouar, Samir; Strauß, Max; Carmele, Alexander; Schnauber, Peter; Thoma, Alexander; Gschrey, Manuel; Schulze, Jan-Hindrik; Strittmatter, André; Rodt, Sven; Knorr, Andreas; Reitzenstein, Stephan

    2017-06-01

    The two-photon dressing of a "three-level ladder" system, here the ground state, the exciton, and the biexciton of a semiconductor quantum dot, leads to new eigenstates and allows one to manipulate the time ordering of the paired photons without unitary postprocessing. We show that, after spectral postselection of the single dressed states, the time ordering of the cascaded photons can be removed or conserved. Our joint experimental and theoretical study demonstrates the high potential of a "ladder" system to be a versatile source of orthogonally polarized, bunched or antibunched pairs of photons.

  14. Substrate geometry controls the cyclization cascade in multiproduct terpene synthases from Zea mays.

    Science.gov (United States)

    Vattekkatte, Abith; Gatto, Nathalie; Köllner, Tobias G; Degenhardt, Jörg; Gershenzon, Jonathan; Boland, Wilhelm

    2015-06-07

    Multiproduct terpene synthases TPS4-B73 and TPS5-Delprim from maize (Zea mays) catalyze the conversion of farnesyl diphosphate (FDP) and geranyl diphosphate (GDP) into a complex mixture of sesquiterpenes and monoterpenes, respectively. Various isotopic and geometric isomers of natural substrates like (2Z)-[2-(2)H]- and [2,4,4,9,9,9-(2)H6]-(GDP) and (2Z,6E)-[2-(2)H]- and [2,4,4,13,13,13-(2)H6]-(FDP) were synthesized analogous to presumptive reaction intermediates. On incubation with labeled (2Z) substrates, TPS4 and TPS5 showed much lower kinetic isotope effects than the labeled (2E) substrates. Interestingly, the products arising from the deuterated (2Z)-precursors revealed a distinct preference for cyclic products and exhibited an enhanced turnover on comparison with natural (2E)-substrates. This increase in the efficiency due to (2Z) configuration emphasizes the rate limiting effect of the initial (2E) → (2Z) isomerization step in the reaction cascade of the multiproduct terpene synthases. Apart from turnover advantages, these results suggest that substrate geometry can be used as a tool to optimize the biosynthetic reaction cascade towards valuable cyclic terpenoids.

  15. Metabolic Derangements in Lichen Planus - A Case Control Study

    Science.gov (United States)

    Kar, Bikash Ranjan; Panda, Maitreyee

    2016-01-01

    Introduction An association between psoriasis and metabolic syndrome has been established in previous studies. Lichen Planus (LP) is also a chronic inflammatory disease morphologically related to psoriasis and few studies have shown association of metabolic derangements in LP. Aim To study the association of metabolic derangements in LP. Materials and Methods A prospective case control study was undertaken for a period of one year. Age and sex matched patients of LP and other non-inflammatory diseases were taken as cases and controls respectively. Data on height, weight, lipid profile and fasting blood glucose levels were collected for all the patients. Body Mass Index (BMI) was calculated. Results A total of 80 patients were recruited, 40 cases and 40 controls. The mean values for all the lipid and glucose parameters were high in cases as compared to controls with significant p-values. Conclusion In the present study metabolic derangements were seen in patients with LP. PMID:28050485

  16. Cellular metabolic and autophagic pathways: traffic control by redox signaling.

    Science.gov (United States)

    Dodson, Matthew; Darley-Usmar, Victor; Zhang, Jianhua

    2013-10-01

    It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function.

  17. Recurrent-neural-network-based identification of a cascade hydraulic actuator for closed-loop automotive power transmission control

    Energy Technology Data Exchange (ETDEWEB)

    You, Seung Han [Hyundai Motor Company, Seoul (Korea, Republic of); Hahn, Jin Oh [University of Alberta, Edmonton (Canada)

    2012-05-15

    By virtue of its ease of operation compared with its conventional manual counterpart, automatic transmissions are commonly used as automotive power transmission control system in today's passenger cars. In accordance with this trend, research efforts on closed-loop automatic transmission controls have been extensively carried out to improve ride quality and fuel economy. State-of-the-art power transmission control algorithms may have limitations in performance because they rely on the steady-state characteristics of the hydraulic actuator rather than fully exploit its dynamic characteristics. Since the ultimate viability of closed-loop power transmission control is dominated by precise pressure control at the level of hydraulic actuator, closed-loop control can potentially attain superior efficacy in case the hydraulic actuator can be easily incorporated into model-based observer/controller design. In this paper, we propose to use a recurrent neural network (RNN) to establish a nonlinear empirical model of a cascade hydraulic actuator in a passenger car automatic transmission, which has potential to be easily incorporated in designing observers and controllers. Experimental analysis is performed to grasp key system characteristics, based on which a nonlinear system identification procedure is carried out. Extensive experimental validation of the established model suggests that it has superb one-step-ahead prediction capability over appropriate frequency range, making it an attractive approach for model-based observer/controller design applications in automotive systems.

  18. Control of cascaded induction-generator systems. Final technical report, 1 September 1983-30 August 1984

    Energy Technology Data Exchange (ETDEWEB)

    Ortmeyer, T.H.

    1984-12-13

    This report documents an investigation of the stability and control of cascaded doubly fed machines (CDFM). These machines are brushless variable-speed constant-frequency electric power generators with potential for application in aircraft. A previous analytical study indicated the CDFM system would be controllable in the subsynchronous operating mode with a passive RL load. The present study contains two steps. First is an investigation of the machine operation in the supersynchronous mode. The second step is an investigation of machine operation with output capacitors providing excitation VARs for the machine and load. Step 1 results show that the machines exhibit stability characteristics in the supersynchronous mode similar to those observed in the subsynchronous mode. Step 2 results show that output capacitors degrade the system performance, particularly at light loads. The results show that output current feedback can be employed to improve the system performance.

  19. Structure of 15-Level Sub-Module Cascaded H-Bridge Inverter for Speed Control of AC Drive Applications

    Directory of Open Access Journals (Sweden)

    R. Uthirasamy

    2015-02-01

    Full Text Available This paper deals with the implementation of a single phase 15-level Sub-Multilevel Cascaded H-Bridge Inverter (SMCHBI for variable speed industrial drive applications. It consists of sub-multilevel modules and H-bridge inverter configuration. Sub-multilevel switches synthesize stepped DC link voltage and current from the DC sources. H-bridge inverter switches renovate stepped DC link voltage and current into sinusoidal waveform. Compared with conventional Cascaded Multilevel Inverter (CMLI, the proposed system employs the reduced number of power switches, DC sources and gate driver requirements. The proposed system not only reduces the overall system cost but also reduces the voltage stress across the inverter switches. The proposed system does not required additional resonant soft switching circuits for Zero Voltage Switching (ZVS of inverter. In the proposed method, variable frequency method is adopted for the speed control of industrial induction motor drives. A prototype model of 15-level SMCHB is developed and the performance of the systems is validated experimentally.

  20. Fine tuning of cascaded d-q axis controller for AC-DC-AC converter without DC link capacitor using artificial neural network

    Directory of Open Access Journals (Sweden)

    Padmanaban Sanjeevikumar

    2008-01-01

    Full Text Available This paper presents an artificial neural network (ANN based approach to tune the parameters of the cascaded d-q axis controller for an AC-DC-AC converter without dc link capacitor. The proposed converter uses the cascaded d-q axis controller on the rectifier side and space vector pulse width modulation on the inverter side. The feed-forward ANN with the error back-propagation training is employed to tune the parameters of the cascaded d-q axis controller. The converter topology provides simple commutation procedure with reduced number of switches and has additional advantages such as good voltage transfer ratio, four quadrant operation, unity power factor, no DC link capacitor and less THD in both the line and load sides. Simulation results closely match with theoretical analysis.

  1. The ACE-2/Ang1-7/Mas cascade enhances bone structure and metabolism following angiotensin-II type 1 receptor blockade.

    Science.gov (United States)

    Abuohashish, Hatem M; Ahmed, Mohammed M; Sabry, Dina; Khattab, Mahmoud M; Al-Rejaie, Salim S

    2017-07-15

    The renin angiotensin system (RAS) regulates numerous systemic functions and is expressed locally in skeletal tissues. Angiotensin1-7 (Ang1-7) is a beneficial member of the RAS, and the therapeutic effects of a large number of angiotensin receptors blockers (ARBs) are mediated by an Ang1-7-dependent cascade. This study examines whether the reported osteo-preservative effects of losartan are mediated through the angiotensin converting enzyme2 (ACE-2)/Ang1-7/Mas pathway in ovariectomized (OVX) rats. Sham and OVX animals received losartan (10mg/kg/d p.o.) for 6 weeks. A specific Mas receptor blocker (A-779) was delivered via mini-osmotic pumps during the losartan treatment period. Serum and urine bone metabolism biomarker levels were measured. Bone trabecular and cortical morphometry were quantified in distal femurs, whereas mineral contents were estimated in ashed bones, serum and urine. Finally, the expression of RAS components, the receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) was determined. Losartan significantly improved the elevated bone metabolism marker levels and altered trabecular and cortical structures in OVX animals, and restored normal urinary and skeletal mineral levels. Mas receptor inhibition significantly abolished all osteo-protective effects of losartan and enhanced the deleterious effects of OVX. Losartan enhanced OVX-induced up-regulation of ACE-1, AngII, angiotensin type 1 (AT1) receptor and RANKL expression, and increased ACE-2, Ang1-7, Mas and OPG expression in OVX animals. However, A-779 significantly eradicated the effects of losartan on RAS components and RANKL/OPG expression. Thus, Ang1-7 are involved in the osteo-preservative effects of losartan via Mas receptor, which may add therapeutic value to this well-known antihypertensive agent. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Integrated metabolic modelling reveals cell-type specific epigenetic control points of the macrophage metabolic network.

    Science.gov (United States)

    Pacheco, Maria Pires; John, Elisabeth; Kaoma, Tony; Heinäniemi, Merja; Nicot, Nathalie; Vallar, Laurent; Bueb, Jean-Luc; Sinkkonen, Lasse; Sauter, Thomas

    2015-10-19

    The reconstruction of context-specific metabolic models from easily and reliably measurable features such as transcriptomics data will be increasingly important in research and medicine. Current reconstruction methods suffer from high computational effort and arbitrary threshold setting. Moreover, understanding the underlying epigenetic regulation might allow the identification of putative intervention points within metabolic networks. Genes under high regulatory load from multiple enhancers or super-enhancers are known key genes for disease and cell identity. However, their role in regulation of metabolism and their placement within the metabolic networks has not been studied. Here we present FASTCORMICS, a fast and robust workflow for the creation of high-quality metabolic models from transcriptomics data. FASTCORMICS is devoid of arbitrary parameter settings and due to its low computational demand allows cross-validation assays. Applying FASTCORMICS, we have generated models for 63 primary human cell types from microarray data, revealing significant differences in their metabolic networks. To understand the cell type-specific regulation of the alternative metabolic pathways we built multiple models during differentiation of primary human monocytes to macrophages and performed ChIP-Seq experiments for histone H3 K27 acetylation (H3K27ac) to map the active enhancers in macrophages. Focusing on the metabolic genes under high regulatory load from multiple enhancers or super-enhancers, we found these genes to show the most cell type-restricted and abundant expression profiles within their respective pathways. Importantly, the high regulatory load genes are associated to reactions enriched for transport reactions and other pathway entry points, suggesting that they are critical regulatory control points for cell type-specific metabolism. By integrating metabolic modelling and epigenomic analysis we have identified high regulatory load as a common feature of metabolic

  3. Coodinative Control of Active Power and DC-link Voltage for Cascaded Dual-Active-Bridge and Inverter in Bidirectional Applications

    DEFF Research Database (Denmark)

    Tian, Yanjun; Chen, Zhe; Deng, Fujin;

    2014-01-01

    A bidirectional interface converter is attractive for the flexible operation and control of a system consisting of a DC sub-grid and an AC sub-grid. Cascaded connection of a dual-active-bridge (DAB) with an inverter is an ideal topology for the bidirectional interface. However, due to the bidirec......A bidirectional interface converter is attractive for the flexible operation and control of a system consisting of a DC sub-grid and an AC sub-grid. Cascaded connection of a dual-active-bridge (DAB) with an inverter is an ideal topology for the bidirectional interface. However, due...

  4. Slave nodes and the controllability of metabolic networks

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hee; Motter, Adilson E [Department of Physics and Astronomy and Northwestern Institute on Complex Systems (NICO), Northwestern University, Evanston, IL 60208 (United States)], E-mail: dong.kim@tkk.fi, E-mail: motter@northwestern.edu

    2009-11-15

    Recent work on synthetic rescues has shown that the targeted deletion of specific metabolic genes can often be used to rescue otherwise non-viable mutants. This raises a fundamental biophysical question: to what extent can the whole-cell behavior of a large metabolic network be controlled by constraining the flux of one or more reactions in the network? This touches upon the issue of the number of degrees of freedom contained by one such network. Using the metabolic network of Escherichia coli as a model system, here we address this question theoretically by exploring not only reaction deletions, but also a continuum of all possible reaction expression levels. We show that the behavior of the metabolic network can be largely manipulated by the pinned expression of a single reaction. In particular, a relevant fraction of the metabolic reactions exhibits canalizing interactions, in that the specification of one reaction flux determines cellular growth as well as the fluxes of most other reactions in optimal steady states. The activity of individual reactions can thus be used as surrogates to monitor and possibly control cellular growth and other whole-cell behaviors. In addition to its implications for the study of control processes, our methodology provides a new approach to study how the integrated dynamics of the entire metabolic network emerges from the coordinated behavior of its component parts.

  5. The metabolic control of schistosome egg production

    Science.gov (United States)

    Pearce, Edward J.; Huang, Stanley Ching-Cheng

    2015-01-01

    Schistosomiasis is a Neglected Tropical Disease caused by infection with trematode parasites of the genus Schistosoma. Despite ongoing treatment programs, the prevalence of schistosomiasis has failed to decline and the disease remains a cause of severe morbidity in millions of people. Understanding the biology of egg production by schistosomes is critical since eggs allow transmission of the infection, and when trapped in host tissues induce the immune responses that are responsible for the pathologic changes that underlie disease development. Unusually among trematodes, adult schistosomes exhibit sexual dimorphism and display a fascinating codependency in that the female is dependent on the male to grow and sexually mature. Thus virgin females are developmentally stunted compared to females from mixed-sex infections and are unable to lay eggs. Moreover, fecund female schistosomes rapidly lose the ability to produce eggs when placed in tissue culture. Here we discuss the metabolic regulation of egg production in schistosomes, and in particular the critical role played by fatty acid oxidation in this process. PMID:25850569

  6. [Nitrogen metabolism and its control mechanisms].

    Science.gov (United States)

    Bergner, H

    1989-01-01

    N intake in the form of protein has neither got an upper nor a lower limit for agricultural working animals within a diet and there is no control mechanism for it. A high surplus of certain amino acids results in a reduction of feed intake. N excretion in faeces depends on 1) the excretion of N containing indigestible feedstuffs, 2) bacterial nitrogen synthesis in the large intestine and 3) the excretion of true endogenous N containing substances (digestion enzymes, intestinal epithelium, N containing endogenous secretion). There are no other control mechanisms for N excretion in faeces. N excretion in urine mainly comprises the nitrogen from the degeneration of amino acids and nucleic acids. The interrelations between urea, NH3, allantoin, creatine and creatinine, uric acid and hippuric acid depend on the species (monogastric or ruminants), on the nitrogen and N amount consumed and on the recycling ratio of the amino acids. The absolute amount of N excretion is not subject to any control mechanism, it depends on the intake of protein and NPN substances, the interim stages, however, which lead to the formation of excretory products, are intermediately controlled. The most important interim stage is protein biosynthesis, which is a fixed, intermediately controlled value in maintenance level. Under growth conditions only, the protein synthesis quota can exceed the protein degradation quota of the total organism (positive N balance). The control mechanisms of protein biosynthesis have, according to current knowledge, the following structure: Stimulation: 1) growth hormone (STH) stimulates protein synthesis by means of somatomedins; 2) hormones of the thyroid gland (T4 and T3) are controlled by the hormone stimulating the thyroid gland (TSH); 3) insulin. Inhibition: 1) somatostatin inhibits STH, TSH and insulin; 2) cortisol directly inhibits protein synthesis and stimulates protein degradation. The control mechanisms of protein turnover in addition to genetic coding

  7. Learning Cascading

    CERN Document Server

    Covert, Michael

    2015-01-01

    This book is intended for software developers, system architects and analysts, big data project managers, and data scientists who wish to deploy big data solutions using the Cascading framework. You must have a basic understanding of the big data paradigm and should be familiar with Java development techniques.

  8. A Real-Time and Closed-Loop Control Algorithm for Cascaded Multilevel Inverter Based on Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Libing Wang

    2014-01-01

    Full Text Available In order to control the cascaded H-bridges (CHB converter with staircase modulation strategy in a real-time manner, a real-time and closed-loop control algorithm based on artificial neural network (ANN for three-phase CHB converter is proposed in this paper. It costs little computation time and memory. It has two steps. In the first step, hierarchical particle swarm optimizer with time-varying acceleration coefficient (HPSO-TVAC algorithm is employed to minimize the total harmonic distortion (THD and generate the optimal switching angles offline. In the second step, part of optimal switching angles are used to train an ANN and the well-designed ANN can generate optimal switching angles in a real-time manner. Compared with previous real-time algorithm, the proposed algorithm is suitable for a wider range of modulation index and results in a smaller THD and a lower calculation time. Furthermore, the well-designed ANN is embedded into a closed-loop control algorithm for CHB converter with variable direct voltage (DC sources. Simulation results demonstrate that the proposed closed-loop control algorithm is able to quickly stabilize load voltage and minimize the line current’s THD (<5% when subjecting the DC sources disturbance or load disturbance. In real design stage, a switching angle pulse generation scheme is proposed and experiment results verify its correctness.

  9. Insulin signaling meets mitochondria in metabolism

    OpenAIRE

    Cheng, Zhiyong; Tseng, Yolanda; White, Morris F.

    2010-01-01

    Insulin controls nutrient and metabolic homeostasis via the IRS–PI3K–AKT signaling cascade that targets FOXO1 and mTOR. Mitochondria, as the prime metabolic platform, malfunction during insulin resistance in metabolic diseases. However, the molecular link between insulin resistance and mitochondrial dysfunction remains undefined. Here we review recent studies on insulin action and the mechanistic association with mitochondrial metabolism. These studies suggest that insulin signaling underpins...

  10. [Glucose Metabolism: Stress Hyperglycemia and Glucose Control].

    Science.gov (United States)

    Tanaka, Katsuya; Tsutsumi, Yasuo M

    2016-05-01

    It is important for the anesthesiologists to understand pathophysiology of perioperative stress hyperglycemia, because it offers strategies for treatment of stress hyperglycemia. The effect of glucose tolerance is different in the choice of the anesthetic agent used in daily clinical setting. Specifically, the volatile anesthetics inhibit insulin secretion after glucose load and affects glucose tolerance. During minor surgery by the remifentanil anesthesia, the stress reaction is hard to be induced, suggesting that we should consider low-dose glucose load. Finally it is necessary to perform the glycemic control of the patients who fell into stress hyperglycemia depending on the individual patient. However, there are a lot of questions to be answered in the future. The prognosis of the perioperative patients is more likely to be greatly improved if we can control stress hyperglycemia.

  11. Community cascades in a marine pelagic food web controlled by the non-visual apex predator Mnemiopsis leidyi

    DEFF Research Database (Denmark)

    Tiselius, Peter; Møller, Lene Friis

    2017-01-01

    Trophic cascades are a ubiquitous feature of many terrestrial and fresh-water food webs, but have been difficult to demonstrate in marine systems with multispecies trophic levels. Here we describe significant trophic cascades in an open coastal planktonic ecosystem exposed to an introduced top pr...

  12. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  13. DC-Link Voltage Coordinated-Proportional Control for Cascaded Converter With Zero Steady-State Error and Reduced System Type

    DEFF Research Database (Denmark)

    Tian, Yanjun; Loh, Poh Chiang; Deng, Fujin

    2016-01-01

    Cascaded converter is formed by connecting two subconverters together, sharing a common intermediate dc-link voltage. Regulation of this dc-link voltage is frequently realized with a proportional-integral (PI) controller, whose high gain at dc helps to force a zero steady-state tracking error...... a coordinated control scheme for the cascaded converter, which uses only a proportional dc-link voltage regulator. The resulting converter is thus dynamically faster, and when compared with the conventional PI-controlled converter, it is less affected by impedance interaction between its two subconverters....... Such precise tracking is, however, at the expense of increasing the system type, caused by the extra pole at the origin introduced by the PI controller. The overall system may, hence, be tougher to control. To reduce the system type while preserving precise dc-link voltage tracking, this paper proposes...

  14. Metabolism

    Science.gov (United States)

    ... Surgery? Choosing the Right Sport for You Shyness Metabolism KidsHealth > For Teens > Metabolism Print A A A ... food through a process called metabolism. What Is Metabolism? Metabolism (pronounced: meh-TAB-uh-lih-zem) is ...

  15. Bile acids, farnesoid X receptor, atherosclerosis and metabolic control

    NARCIS (Netherlands)

    Kuipers, Folkert; Stroeve, Johanna H. M.; Caron, Sandrine; Staels, Bart

    2007-01-01

    Purpose of review Bile acids are amphiphilic molecules synthesized from cholesterol exclusively in the liver that are essential for effective absorption of dietary fat. In addition to this classical role', bile acids act as signalling molecules that control their own metabolism by activating the nuc

  16. Metabolic control analysis of Aspergillus niger L-arabinose catabolism

    DEFF Research Database (Denmark)

    de Groot, M.J.L.; Prathumpai, Wai; Visser, J.

    2005-01-01

    -arabinose, a level that resulted in realistic intermediate concentrations in the model, flux control coefficients for L-arabinose reductase, L-arabitol dehydrogenase and L-xylulose reductase were 0.68, 0.17 and 0.14, respectively. The analysis can be used as a guide to identify targets for metabolic engineering......, and their kinetic properties were characterized. For the other enzymes of the pathway the kinetic data were available from the literature. The metabolic model was used to analyze flux and metabolite concentration control of the L-arabinose catabolic pathway. The model demonstrated that flux control does not reside...... at the enzyme following the intermediate with the highest concentration, L-arabitol, but is distributed over the first three steps in the pathway, preceding and following L-arabitol. Flux control appeared to be strongly dependent on the intracellular L-arabinose concentration. At 5 mM intracellular L...

  17. Numerical Investigation of Active Tip-clearance Control through Tip Cooling Injection in an Axial Turbine Cascade

    Institute of Scientific and Technical Information of China (English)

    Maosheng Niu; Shusheng Zang

    2009-01-01

    This paper presents a numerical investigation of an active tip-clearance control method based on cooling injection from the blade tip surface. It aims to study the influences of air injection on controlling tip clearance flow, with emphasis on the effects of the injection location on secondary flow and the potential thermal benefits from the cooling jet. The results show that injection location plays an important role in the redistribution of secondary flow within the cascade passage. Injection located much closer to the pressure-side comer performs better in reducing tip clearance massflow and its associated losses. However, it also intensifies tip passage vortex, due to less re-straint deriving from the reduced tip clearance vortex. Lower plenum total pressure is required to inject equivalent amount of cooling air, but the heat transfer condition on the blade tip surface is a bit worse than that with injection from the reattachment region. Thus the optimum location of air injection should be at the tip separation vortex re-gion.

  18. Rebamipide ameliorates atherosclerosis by controlling lipid metabolism and inflammation.

    Science.gov (United States)

    Jhun, JooYeon; Kwon, Jeong-Eun; Kim, Se-Young; Jeong, Jeong-Hee; Na, Hyun Sik; Kim, Eun-Kyung; Lee, Seung Hoon; Jung, KyungAh; Min, Jun-Ki; Cho, Mi-La

    2017-01-01

    The oral administration of rebamipide decreased plaque formation in atherosclerotic lesions as well as the markers of metabolic disorder in ApoE-deficient mice with atherosclerosis. Pro-inflammatory cytokines were also suppressed by rebamapide. In addition, the population of Th17 was decreased, whereas Treg was increased in the spleen of rebamipide-treated ApoE deficient mice. Rebamipide also ameliorated the severity of obese arthritis and has the capability to reduce the development of atherosclerosis by controlling the balance between Th17 and Treg cells. Thus, rebamipide could be a therapeutic agent to improve the progression of inflammation in metabolic diseases.

  19. An Analytic Approach to Cascade Control Design for Hydraulic Valve-Cylinder Drives

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Hansen, Anders Hedegaard; Andersen, Torben O.

    2016-01-01

    control and possibly linear active damping functionalities. However difficulties often arise due to the inherent and strong nonlinear nature of hydraulic drives, with the more dominant being nonlinear valve flow- and oil stiffness characteristics, and furthermore the volume expansion/retraction when...

  20. Control of mitochondrial volume by mitochondrial metabolic water.

    Science.gov (United States)

    Casteilla, Louis; Devin, Anne; Carriere, Audrey; Salin, Bénédicte; Schaeffer, Jacques; Rigoulet, Michel

    2011-11-01

    It is well-known that mitochondrial volume largely controls mitochondrial functioning. We investigate whether metabolic water produced by oxidative phosphorylation could be involved in mitochondrial volume regulation. We modulated the generation of this water in liver mitochondria and assess their volume by two independent techniques. In liver mitochondria, the mitochondrial volume was specifically decreased when no water was produced independently of energetic parameters and uncoupling activity. In all other conditions associated with water generation, there was no significant change in mitochondrial metabolic volume. Altogether these data demonstrate that mitochondrial volume is regulated, independently of energetic status, by the mitochondrial metabolic water that acts as a signal. Copyright © 2011 Elsevier B.V. and Mitochondria Research Society. All rights reserved. All rights reserved.

  1. A GRID CONNECTED PV SYSTEM INTEGRATED THROUGH MULTILEVEL MODULAR CASCADED H-BRIDGE INVERTER BY USING FUZZY LOGIC CONTROLLER

    OpenAIRE

    2016-01-01

    This paper presents a modular cascaded H-bridge multilevel photovoltaic (PV) inverter for three-phase grid-connected applications. The modular cascaded multilevel topology helps to improve the efficiency and flexibility of PV systems. The main abstruse is the harmonization of the DG to the utility grid. Generally current regulated PWM voltage-source inverters (VSI) are used for synchronizing the utility grid with DG source in order to meet the following objectives: 1) To ensure grid stability...

  2. Controllable all-optical stochastic logic gates and their delay storages based on the cascaded VCSELs with optical-injection

    Science.gov (United States)

    Zhong, Dongzhou; Luo, Wei; Xu, Geliang

    2016-09-01

    Using the dynamical properties of the polarization bistability that depends on the detuning of the injected light, we propose a novel approach to implement reliable all-optical stochastic logic gates in the cascaded vertical cavity surface emitting lasers (VCSELs) with optical-injection. Here, two logic inputs are encoded in the detuning of the injected light from a tunable CW laser. The logic outputs are decoded from the two orthogonal polarization lights emitted from the optically injected VCSELs. For the same logic inputs, under electro-optic modulation, we perform various digital signal processing (NOT, AND, NAND, XOR, XNOR, OR, NOR) in the all-optical domain by controlling the logic operation of the applied electric field. Also we explore their delay storages by using the mechanism of the generalized chaotic synchronization. To quantify the reliabilities of these logic gates, we further demonstrate their success probabilities. Project supported by the National Natural Science Foundation of China (Grant No. 61475120) and the Innovative Projects in Guangdong Colleges and Universities, China (Grant Nos. 2014KTSCX134 and 2015KTSCX146).

  3. Controllable Chemoselectivity in Visible-Light Photoredox Catalysis: Four Diverse Aerobic Radical Cascade Reactions.

    Science.gov (United States)

    Liu, Xinfei; Ye, Xinyi; Bureš, Filip; Liu, Hongjun; Jiang, Zhiyong

    2015-09-21

    Reported is the controllable selectivity syntheses of four distinct products from the same starting materials by visible-light photoredox catalysis. By employing a dicyanopyrazine-derived chromophore (DPZ) as photoredox catalyst, an aerobic radical mechanism has been developed, and allows the reactions of N-tetrahydroisoquinolines (THIQs) with N-itaconimides to through four different pathways, including addition-cyclization, addition-elimination, addition-coupling, and addition-protonation, with satisfactory chemoselectivity. The current strategy provide straightforward access to four different but valuable N-heterocyclic adducts in moderate to excellent yields. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. (Im)Perfect robustness and adaptation of metabolic networks subject to metabolic and gene-expression regulation: marrying control engineering with metabolic control analysis.

    Science.gov (United States)

    He, Fei; Fromion, Vincent; Westerhoff, Hans V

    2013-11-21

    Metabolic control analysis (MCA) and supply-demand theory have led to appreciable understanding of the systems properties of metabolic networks that are subject exclusively to metabolic regulation. Supply-demand theory has not yet considered gene-expression regulation explicitly whilst a variant of MCA, i.e. Hierarchical Control Analysis (HCA), has done so. Existing analyses based on control engineering approaches have not been very explicit about whether metabolic or gene-expression regulation would be involved, but designed different ways in which regulation could be organized, with the potential of causing adaptation to be perfect. This study integrates control engineering and classical MCA augmented with supply-demand theory and HCA. Because gene-expression regulation involves time integration, it is identified as a natural instantiation of the 'integral control' (or near integral control) known in control engineering. This study then focuses on robustness against and adaptation to perturbations of process activities in the network, which could result from environmental perturbations, mutations or slow noise. It is shown however that this type of 'integral control' should rarely be expected to lead to the 'perfect adaptation': although the gene-expression regulation increases the robustness of important metabolite concentrations, it rarely makes them infinitely robust. For perfect adaptation to occur, the protein degradation reactions should be zero order in the concentration of the protein, which may be rare biologically for cells growing steadily. A proposed new framework integrating the methodologies of control engineering and metabolic and hierarchical control analysis, improves the understanding of biological systems that are regulated both metabolically and by gene expression. In particular, the new approach enables one to address the issue whether the intracellular biochemical networks that have been and are being identified by genomics and systems

  5. [Metabolic control in children and adolescents with type 1 diabetes].

    Science.gov (United States)

    Díaz-Cárdenas, Claudia; Wong, Carolina; Vargas Catalán, Nelson A

    2016-01-01

    Type 1 diabetes mellitus (T1D) is an important disease in children and adolescent being a major risk factor for early morbidity and mortality. To know the degree of metabolic control and prevalence of cardiovascular risk factors in T1D patients. Retrospective study including patients under 19 years of age with T1D controlled at a Chilean hospital in 2011. 94 patients were evaluated (average age at diagnosis: 7.3 years; current age: 11,9 years; evolution time: 4.5 years). Seventy-nine percent (79.8%) of patients presented glycated hemoglobin (HbA1c) over the recommended level with an average of 8.9%. The group between 13 and 19 years of age exhibited the worst metabolic control (86% with HbA1c abnormal levels). Overweight or obesity occurred in 26.6% of patients, 20.3% had LDL >100mg/dl and 4.2% had hypertension. Only about twenty percent of patients had adequate metabolic control as measured by HbA1c, although cardiovascular risk profile was acceptable. Therapeutic and educational efforts must be reinforced mainly in adolescents, emphasizing the importance of adequate nutritional management as a primary method to treat this entity. Copyright © 2015 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. A New Control Method for Grid-Connected PV System Based on Quasi-Z-Source Cascaded Multilevel Inverter Using Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Hamid Reza Mohammadi

    2015-03-01

    Full Text Available In this paper, a new control method for quasi-Z-source cascaded multilevel inverter based grid-connected photovoltaic (PV system is proposed. The proposed method is capable of boosting the PV array voltage to a higher level and solves the imbalance problem of DC-link voltage in traditional cascaded H-bridge inverters. The proposed control system adjusts the grid injected current in phase with the grid voltage and achieves independent maximum power point tracking (MPPT for the separate PV arrays. To achieve these goals, the proportional-integral (PI controllers are employed for each module. For achieving the best performance, this paper presents an optimum approach to design the controller parameters using particle swarm optimization (PSO. The primary design goal is to obtain good response by minimizing the integral absolute error. Also, the transient response is guaranteed by minimizing the overshoot, settling time and rise time of the system response. The effectiveness of the new proposed control method has been verified through simulation studies based on a seven level quasi-Z-Source cascaded multilevel inverter.

  7. Cerberus-Nodal-Lefty-Pitx signaling cascade controls left-right asymmetry in amphioxus.

    Science.gov (United States)

    Li, Guang; Liu, Xian; Xing, Chaofan; Zhang, Huayang; Shimeld, Sebastian M; Wang, Yiquan

    2017-04-04

    Many bilaterally symmetrical animals develop genetically programmed left-right asymmetries. In vertebrates, this process is under the control of Nodal signaling, which is restricted to the left side by Nodal antagonists Cerberus and Lefty. Amphioxus, the earliest diverging chordate lineage, has profound left-right asymmetry as a larva. We show that Cerberus, Nodal, Lefty, and their target transcription factor Pitx are sequentially activated in amphioxus embryos. We then address their function by transcription activator-like effector nucleases (TALEN)-based knockout and heat-shock promoter (HSP)-driven overexpression. Knockout of Cerberus leads to ectopic right-sided expression of Nodal, Lefty, and Pitx, whereas overexpression of Cerberus represses their left-sided expression. Overexpression of Nodal in turn represses Cerberus and activates Lefty and Pitx ectopically on the right side. We also show Lefty represses Nodal, whereas Pitx activates Nodal These data combine in a model in which Cerberus determines whether the left-sided gene expression cassette is activated or repressed. These regulatory steps are essential for normal left-right asymmetry to develop, as when they are disrupted embryos may instead form two phenotypic left sides or two phenotypic right sides. Our study shows the regulatory cassette controlling left-right asymmetry was in place in the ancestor of amphioxus and vertebrates. This includes the Nodal inhibitors Cerberus and Lefty, both of which operate in feedback loops with Nodal and combine to establish asymmetric Pitx expression. Cerberus and Lefty are missing from most invertebrate lineages, marking this mechanism as an innovation in the lineage leading to modern chordates.

  8. Cascading Cosmology

    CERN Document Server

    Agarwal, Nishant; Khoury, Justin; Trodden, Mark

    2009-01-01

    We develop a fully covariant, well-posed 5D effective action for the 6D cascading gravity brane-world model, and use this to study cosmological solutions. We obtain this effective action through the 6D decoupling limit, in which an additional scalar degree mode, \\pi, called the brane-bending mode, determines the bulk-brane gravitational interaction. The 5D action obtained this way inherits from the sixth dimension an extra \\pi self-interaction kinetic term. We compute appropriate boundary terms, to supplement the 5D action, and hence derive fully covariant junction conditions and the 5D Einstein field equations. Using these, we derive the cosmological evolution induced on a 3-brane moving in a static bulk. We study the strong- and weak-coupling regimes analytically in this static ansatz, and perform a complete numerical analysis of our solution. Although the cascading model can generate an accelerating solution in which the \\pi field comes to dominate at late times, the presence of a critical singularity prev...

  9. Rigid, Branched Porphyrin Antennas: Control over Cascades of Unidirectional Energy Funneling and Charge Transfer.

    Science.gov (United States)

    Wolf, Maximilian; Herrmann, Astrid; Hirsch, Andreas; Guldi, Dirk M

    2017-08-30

    Porphyrin arrays consisting of three peripheral Zinc porphyrins (ZnPs) and a central free base porphyrin (H2P)-all rigidly linked to each other-serve as light-harvesting antennas as well as electron donors and are flexibly coupled to an electron-accepting C60 to realize the unidirectional flow of (i) excited-state energy from the ZnPs at the periphery to the H2P, (ii) electrons to C60, and (iii) holes to H2P and, subsequently, to ZnP. Dynamics following photoexcitation are elucidated by time-resolved transient absorption measurements on the femto-, pico-, nano-, and microsecond time scales and are examined by multiwavelength as well as target analyses. Hereby, full control over the charge shift between H2P and ZnP to convert the (ZnP)3-H2P(•+)-C60(•-) charge-separated state into (ZnP)3(•+)-H2P-C60(•-) charge-separated state is enabled by the solvent polarity: It is deactivated/switched-off in apolar toluene, while in polar benzonitrile it is activated/switched-on. Activating/switching impacts the recovery of the ground state via charge recombination rates, which differ by up to 2 orders of magnitude. All charge-separated states lead to the repopulation of the ground state with dynamics that are placed in the inverted region of the Marcus parabola.

  10. Pleiotropy in the wild: the dormancy gene DOG1 exerts cascading control on life cycles.

    Science.gov (United States)

    Chiang, George C K; Barua, Deepak; Dittmar, Emily; Kramer, Elena M; de Casas, Rafael Rubio; Donohue, Kathleen

    2013-03-01

    In the wild, organismal life cycles occur within seasonal cycles, so shifts in the timing of developmental transitions can alter the seasonal environment experienced subsequently. Effects of genes that control the timing of prior developmental events can therefore be magnified in the wild because they determine seasonal conditions experienced by subsequent life stages, which can influence subsequent phenotypic expression. We examined such environmentally induced pleiotropy of developmental-timing genes in a field experiment with Arabidopsis thaliana. When studied in the field under natural seasonal variation, an A. thaliana seed-dormancy gene, Delay Of Germination 1 (DOG1), was found to influence not only germination, but also flowering time, overall life history, and fitness. Flowering time of the previous generation, in turn, imposed maternal effects that altered germination, the effects of DOG1 alleles, and the direction of natural selection on these alleles. Thus under natural conditions, germination genes act as flowering genes and potentially vice versa. These results illustrate how seasonal environmental variation can alter pleiotropic effects of developmental-timing genes, such that effects of genes that regulate prior life stages ramify to influence subsequent life stages. In this case, one gene acting at the seed stage impacted the entire life cycle.

  11. An Implementation Mechanisms of SVM Control Strategies Applied to Five Levels Cascaded Multi-Level Inverters

    Directory of Open Access Journals (Sweden)

    Mohammed Yaichi

    2014-03-01

    Full Text Available In the area of the energy control with high voltage and power, the multilevel inverters constitute a relatively recent research orientation. The current applications of this technology are in the domains of the high voltage (over hundred kV, variable speed drives, transport and distribution of a good quality of electrical energy (HVDC, FACTS system, ..... To improve the output voltage for such inverters, many different modulation strategies have been developed. Among these strategies, the SVM (Space Vector Modulation. The technique provide the nearest switching vectors sequence to the reference vector without involving trigonometric functions and provide the additional advantages of superior harmonic quality. In this paper, we analyze different mechanisms of the output voltage synthesis and the problem of even order harmonic production. With the proposed a new trajectory SVM, which can eliminate all the even order harmonics for five levels inverter. Show clearly how to deduce the trajectories from the sequences allowing to have better performances among several possible trajectories. It is dedicated to the application of two particular trajectories.

  12. Integration and control of metabolic systems: Pure and applied aspects

    Energy Technology Data Exchange (ETDEWEB)

    Wong, P.T.H.; Kon, O.L.; Chung, M.C.M.; Hwang, P.L.H.; Leong, S.F.; Loke, K.H.; Thiyagarajah, P.

    1987-01-01

    This volume brings together recent findings in many growing areas of biochemical research including molecular mechanisms of disease, drug design, gene structure and function, chemical signaling, metabolic control mechanisms, neurochemistry, immunology, the molecular biology of plants, marine biochemistry, oncogenes, growth factors, membrane functions, novel enzymes, applied biochemistry, and molecular engineering. It also contains contributions on powerful research techniques such as pulsed field gel electrophoresis, automated DNA sequencing, photoaffinity labeling, recent advances in plant cell culture, and high performance liquid chromatography.

  13. Leptin and the CNS Control of Glucose Metabolism

    Science.gov (United States)

    Morton, Gregory J.; Schwartz, Michael W.

    2012-01-01

    The regulation of body fat stores and blood glucose levels is critical for survival. This review highlights growing evidence that leptin action in the central nervous system (CNS) plays a key role in both processes. Investigation into underlying mechanisms has begun to clarify the physiological role of leptin in the control of glucose metabolism and raises interesting new possibilities for the treatment of diabetes and related disorders. PMID:21527729

  14. Research on Control Method for Intermediate Point Temperature of Supercritical Boiler Based on Active Disturbance Rejection Cascade Control

    Directory of Open Access Journals (Sweden)

    Junjie Gu

    2013-07-01

    Full Text Available As the important signal of once-through boiler's water-fuel ratio control, intermediate point temperature of supercritical boiler plays a key role in the decision of steam and water’s boundary, the match of fuel and water, the control of main steam temperature. The condition of its control directly impacts the once-through boiler’s safety and economy running. For an uncertainty model, a good control quality can not be gained using the general PID controller when the unit load has great changes, so that the main steam temperature fluctuates greatly. According to this problem, a control system about intermediate point temperature of supercritical boiler based on active-disturbances-rejection multiple model was designed. Corresponding active disturbances rejection controller (ADRC about different model in different operation points was designed. It can choose corresponding controller according to the operation condition so as to achieve an adaptive control of a wide range. The simulation results show that the system has a strong robustness and sufficient capability for control.  

  15. State of Charge Balancing Control of a Multi-Functional Battery Energy Storage System Based on a 11-Level Cascaded Multilevel PWM Converter

    DEFF Research Database (Denmark)

    Wang, Songcen; Teodorescu, Remus; Máthé, Lászlo

    2015-01-01

    This paper focuses on modeling and SOC (State of Charge) balancing control of lithium-ion battery energy storage system based on cascaded multilevel converter for both grid integration and electric vehicle propulsion applications. The equivalent electrical circuit model of lithium-ion battery...... is adopted to control active power and reactive power independently, and the zero-sequence voltage injection and a sorting and select algorithm are employed for SOC balancing control. The simulation results have been carried out with PLECS Simulation Software and are presented to validate the SOC control...

  16. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out...... specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of Aspergillus...

  17. [Review on periodontal disease and metabolic control of diabetes mellitus].

    Science.gov (United States)

    Steffens, João Paulo; Glaci Reinke, Stella Maria; Angel Muñoz, Miguel; Santos, Fábio André dos; Luiz Pilatti, Gibson

    2010-09-01

    There may be an interaction between periodontal disease and some systemic diseases such as diabetes mellitus. The objective of this review was to verify, by means of a review of clinical trials, if there is a positive association between periodontal disease and the glycemic control of type 2 diabetes mellitus (DM-2) patients. Eleven articles that fi t the study criteria were revised. It was concluded that periodontal disease may influence the metabolic control of DM-2. Additional studies with larger sample sizes and longer follow up are necessary for a better clarification of this issue.

  18. Role of Autophagy in the Control of Body Metabolism

    Directory of Open Access Journals (Sweden)

    Wenying Quan

    2013-03-01

    Full Text Available Autophagy plays a crucial role in the maintenance of cellular nutrient balance and the function of organelles such as mitochondria or the endoplasmic reticulum, which are important in intracellular metabolism, insulin release, and insulin sensitivity. In the insulin-producing pancreatic β-cells, autophagy is important in the maintenance of β-cell mass, structure, and function. Mice with deficiencies in β-cell-specific autophagy show reduced β-cell mass and defects in insulin secretion that lead to hypoinsulinemia and hyperglycemia but not diabetes. However, these mice developed diabetes when bred with ob/ob mice, suggesting that autophagy-deficient β-cells have defects in dealing with the increased metabolic stress imposed by obesity. These results also imply that autophagy deficiency in β-cells could be a factor in the progression from obesity to diabetes. Another important function of autophagy is in hypothalamic neurons for the central control of energy expenditure, appetite, and body weight. In addition, mice with autophagy deficiencies in the target tissues of insulin have yielded diverse phenotypes. Taken together, these results suggest that autophagy is important in the control of whole body energy and nutrient homeostasis, and its dysregulation could play a role in the development of metabolic disorders and diabetes.

  19. Sense and Nonsense in Metabolic Control of Reproduction

    Directory of Open Access Journals (Sweden)

    Jill eSchneider

    2012-03-01

    Full Text Available An exciting synergistic interaction occurs among researchers working at the interface of reproductive biology and energy homeostasis. Reproductive biologists benefit from the theories, experimental designs, and methodologies used by experts on energy homeostasis, and bring context and meaning to the study of energy homeostasis. There is a growing recognition that identification of candidate genes for obesity is little more than meaningless reductionism unless those genes and their expression are placed in a developmental, environmental, and evolutionary context. Reproductive biology provides this context because 1 metabolic energy is the most important factor that controls reproductive success, 2 gonadal hormones affect energy intake, storage and expenditure, 3 reproductive hormone secretion changes during development, and 4 reproductive success is key to evolutionary adaptation, the process that most likely molded the mechanisms that control energy balance. It is likely that by viewing energy intake, storage, and expenditure in the context of reproductive success, we will gain insight into human obesity, eating disorders, diabetes, and other pathologies related to fuel homeostasis.This review emphasizes the metabolic hypothesis: A sensory system monitors the availability of oxidizable metabolic fuels and orchestrates behavioral motivation to optimize reproductive success in environments where energy availability fluctuates or is unpredictable.

  20. The AngFus3 Mitogen-Activated Protein Kinase Controls Hyphal Differentiation and Secondary Metabolism in Aspergillus niger.

    Science.gov (United States)

    Priegnitz, Bert-Ewald; Brandt, Ulrike; Pahirulzaman, Khomaizon A K; Dickschat, Jeroen S; Fleißner, André

    2015-06-01

    Adaptation to a changing environment is essential for the survival and propagation of sessile organisms, such as plants or fungi. Filamentous fungi commonly respond to a worsening of their growth conditions by differentiation of asexually or sexually produced spores. The formation of these specialized cell types is, however, also triggered as part of the general life cycle by hyphal age or density. Spores typically serve for dispersal and, therefore, translocation but can also act as resting states to endure times of scarcity. Eukaryotic differentiation in response to environmental and self-derived signals is commonly mediated by three-tiered mitogen-activated protein (MAP) kinase signaling cascades. Here, we report that the MAP kinase Fus3 of the black mold Aspergillus niger (AngFus3) and its upstream kinase AngSte7 control vegetative spore formation and secondary metabolism. Mutants lacking these kinases are defective in conidium induction in response to hyphal density but are fully competent in starvation-induced sporulation, indicating that conidiation in A. niger is triggered by various independent signals. In addition, the mutants exhibit an altered profile of volatile metabolites and secrete dark pigments into the growth medium, suggesting a dysregulation of the secondary metabolism. By assigning the AngFus3 MAP kinase pathway to the transduction of a potentially self-derived trigger, this work contributes to the unraveling of the intricate signaling networks controlling fungal differentiation. Moreover, our data further support earlier observations that differentiation and secondary metabolism are tightly linked in filamentous fungi.

  1. Metabolic control analysis of xylose catabolism in Aspergillus

    DEFF Research Database (Denmark)

    Prathumpai, Wai; Gabelgaard, J.B.; Wanchanthuek, P.

    2003-01-01

    A kinetic model for xylose catabolism in Aspergillus is proposed. From a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. Use of the kinetic model allowed metabolic control analysis (MCA) of the xylose catabolic pathway to be carried out......, and flux control was shown to be dependent on the metabolite levels. Due to thermodynamic constraints, flux control may reside at the first step in the pathway, i.e., at the xylose reductase, even when the intracellular xylitol concentration is high. On the basis of the kinetic analysis, the general dogma...... specifying that flux control often resides at the step following an intermediate present at high concentrations was, therefore, shown not to hold. The intracellular xylitol concentration was measured in batch cultivations of two different strains of Aspergillus niger and two different strains of Aspergillus...

  2. A modified GWO technique based cascade PI-PD controller for AGC of power systems in presence of Plug in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Sasmita Padhy

    2017-04-01

    Full Text Available A Modified Grey Wolf Optimization (MGWO based cascade PI-PD controller is suggested in this paper for Automatic Generation Control (AGC of power systems in presence of Plug in Electric Vehicles (PEV. The modification in original Grey Wolf Optimization (GWO algorithm is introduced by strategy which maintains a proper balance between exploration and exploitation stages of the algorithm and gives more importance to the fittest wolves to find the new position of grey wolves during the iterations. Proposed algorithm is first tested using four bench mark test functions and compared with original GWO, Differential Evolution (DE, Gravitational Search Algorithm (GSA, Particle Swarm Optimization (PSO to show its superiority. The proposed technique is then used to tune various conventional controllers in a single area three-unit power system consisting of thermal hydro and gas power plants for AGC. The superiority of proposed MGWO algorithm over some recently proposed approaches has been demonstrated. In the next step, different controllers like PI, PID, and cascaded PI-PD controller are taken and Plug in Electric Vehicles (PEVs are assumed. The proposed approach is also extended to a two-area six-unit power system. Lastly, a five unequal area nonlinear power system with PEVs and dissimilar cascade PI-PD controller in each area is considered and proposed MGWO technique is employed to optimize the controller parameters in presence of nonlinearities like rate constraint of units, dead zone of governor and communication delay. It is observed that PEVs contribute in the AGC to control system frequency.

  3. Control of immune response by amino acid metabolism.

    Science.gov (United States)

    Grohmann, Ursula; Bronte, Vincenzo

    2010-07-01

    The interaction between pathogenic microorganisms and their hosts is regulated by reciprocal survival strategies, including competition for essential nutrients. Though paradoxical, mammalian hosts have learned to take advantage of amino acid catabolism for controlling pathogen invasion and, at the same time, regulating their own immune responses. In this way, ancient catabolic enzymes have acquired novel functions and evolved into new structures with highly specialized functions, which go beyond the struggle for survival. In this review, we analyze the evidence supporting a critical role for the metabolism of various amino acids in regulating different steps of both innate and adaptive immunity.

  4. Metabolic engineering of lactic acid bacteria, the combined approach: kinetic modelling, metabolic control and experimental analysis.

    Science.gov (United States)

    Hoefnagel, Marcel H N; Starrenburg, Marjo J C; Martens, Dirk E; Hugenholtz, Jeroen; Kleerebezem, Michiel; Van Swam, Iris I; Bongers, Roger; Westerhoff, Hans V; Snoep, Jacky L

    2002-04-01

    Everyone who has ever tried to radically change metabolic fluxes knows that it is often harder to determine which enzymes have to be modified than it is to actually implement these changes. In the more traditional genetic engineering approaches 'bottle-necks' are pinpointed using qualitative, intuitive approaches, but the alleviation of suspected 'rate-limiting' steps has not often been successful. Here the authors demonstrate that a model of pyruvate distribution in Lactococcus lactis based on enzyme kinetics in combination with metabolic control analysis clearly indicates the key control points in the flux to acetoin and diacetyl, important flavour compounds. The model presented here (available at http://jjj.biochem.sun.ac.za/wcfs.html) showed that the enzymes with the greatest effect on this flux resided outside the acetolactate synthase branch itself. Experiments confirmed the predictions of the model, i.e. knocking out lactate dehydrogenase and overexpressing NADH oxidase increased the flux through the acetolactate synthase branch from 0 to 75% of measured product formation rates.

  5. Space Station CMIF extended duration metabolic control test

    Science.gov (United States)

    Schunk, Richard G.; Bagdigian, Robert M.; Carrasquillo, Robyn L.; Ogle, Kathryn Y.; Wieland, Paul O.

    1989-01-01

    The Space Station Extended Duration Metabolic Control Test (EMCT) was conducted at the MSFC Core Module Integration Facility. The primary objective of the EMCT was to gather performance data from a partially-closed regenerative Environmental Control and Life Support (ECLS) system functioning under steady-state conditions. Included is a description of the EMCT configuration, a summary of events, a discussion of anomalies that occurred during the test, and detailed results and analysis from individual measurements of water and gas samples taken during the test. A comparison of the physical, chemical, and microbiological methods used in the post test laboratory analyses of the water samples is included. The preprototype ECLS hardware used in the test, providing an overall process description and theory of operation for each hardware item. Analytical results pertaining to a system level mass balance and selected system power estimates are also included.

  6. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  7. Metabolism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    2008255 Serum adiponectin level declines in the elderly with metabolic syndrome.WU Xiaoyan(吴晓琰),et al.Dept Geriatr,Huashan Hosp,Fudan UnivShanghai200040.Chin J Geriatr2008;27(3):164-167.Objective To investigate the correlation between ser-um adiponectin level and metabolic syndrome in the elderly·Methods Sixty-one subjects with metabolic syndrome and140age matched subjects without metabolic

  8. Interplay of phase-sensitive amplification and cascaded four-wave mixing in dispersion-controlled waveguides

    Science.gov (United States)

    Martin, Aude; Combrié, Sylvain; Willinger, Amnon; Eisenstein, Gadi; de Rossi, Alfredo

    2016-08-01

    Phase-sensitive parametric interactions can selectively process the two complex quadratures of the optical field. We implement phase-sensitive amplification in a large band-gap semiconductor photonic crystal waveguide in order to avoid two-photon absorption and free-carrier-related effects. Experimentally, an extinction ratio of 15 dB is achieved in a 1.5-mm-long photonic crystal waveguide, at a peak pump power of about 600 mW. We show that cascaded parametric interaction has a strong impact on squeezing and phase-sensitive extinction ratio and that this depends on the dispersion profile of the waveguide.

  9. Effect of a fermented dietary supplement containing chromium and zinc on metabolic control in patients with type 2 diabetes: a randomized, placebo-controlled, double-blind cross-over study

    Directory of Open Access Journals (Sweden)

    Yu-Mi Lee

    2016-06-01

    Full Text Available Background: For the increasing development of type 2 diabetes dietary habits play an important role. In this regard, dietary supplements are of growing interest to influence the progression of this disease. Objective: The aim of this study was to investigate the effect of a cascade-fermented dietary supplement based on fruits, nuts, and vegetables fortified with chromium and zinc on metabolic control in patients with type 2 diabetes mellitus. Methods: This was a randomized, placebo-controlled, double-blind, intervention study under free-living conditions using a cross-over design. Thirty-six patients with type 2 diabetes mellitus were enrolled and randomized either to receive a cascade-fermented dietary supplement enriched with chromium (100 µg/d and zinc (15 mg/d or a placebo similar in taste but without supplements, over a period of 12 weeks. After a wash-out period of 12 weeks, the patients received the other test product. The main outcome variable was the levels of glycated hemoglobin (HbA1c. Other outcome variables were fasting blood glucose, fructosamine, and lipid parameters. Results: Thirty-one patients completed the study. HbA1c showed no relevant changes during both treatment periods, nor was there a relevant difference between the two treatments (HbA1c: p=0.48. The same results were found for fructosamine and fasting glucose (fructosamine: p=0.9; fasting glucose: p=0.31. In addition, there was no effect on lipid metabolism. Conclusion: This intervention study does not provide evidence that a cascade-fermented plant-based dietary supplement enriched with a combination of chromium and zinc improves glucose metabolism in patients with type 2 diabetes mellitus under free-living conditions.

  10. Local cerebral glucose metabolism during controlled hypoxemia in rats.

    Science.gov (United States)

    Pulsinelli, W A; Duffy, T E

    1979-05-11

    2-Deoxy-[14C]glucose metabolism was examined in brains of hypoxic, normotensive rats by autoradiography, which revealed alternating cortical columns of high and low metabolism. Activity in white matter was increased severalfold over that in adjacent gray matter. The columns were anatomically related to penetrating cortical arteries with areas between arteries demonstrating higher rates of metabolism. The results suggest the presence of interarterial tissue oxygen gradients that influence regional glucose metabolism. The relatively greater sensitivity of white matter metabolism to hypoxia may lead to an understanding of white matter damage in postanoxic leukoencephalopathy.

  11. CASCADE, a platform for controlled gene amplification for high, tunable and selection-free gene expression in yeast

    Science.gov (United States)

    Strucko, Tomas; Buron, Line Due; Jarczynska, Zofia Dorota; Nødvig, Christina Spuur; Mølgaard, Louise; Halkier, Barbara Ann; Mortensen, Uffe Hasbro

    2017-01-01

    Over-expression of a gene by increasing its copy number is often desirable in the model yeast Saccharomyces cerevisiae. It may facilitate elucidation of enzyme functions, and in cell factory design it is used to increase production of proteins and metabolites. Current methods are typically exploiting expression from the multicopy 2 μ-derived plasmid or by targeting genes repeatedly into sequences like Ty or rDNA; in both cases, high gene expression levels are often reached. However, with 2 μ-based plasmid expression, the population of cells is very heterogeneous with respect to protein production; and for integration into repeated sequences it is difficult to determine the genetic setup of the resulting strains and to achieve specific gene doses. For both types of systems, the strains often suffer from genetic instability if proper selection pressure is not applied. Here we present a gene amplification system, CASCADE, which enables construction of strains with defined gene copy numbers. One or more genes can be amplified simultaneously and the resulting strains can be stably propagated on selection-free medium. As proof-of-concept, we have successfully used CASCADE to increase heterologous production of two fluorescent proteins, the enzyme β-galactosidase the fungal polyketide 6-methyl salicylic acid and the plant metabolite vanillin glucoside. PMID:28134264

  12. Feedback Control of the Arachidonate Cascade in Osteoblastic Cells by 15-deoxy-Δ12,14-Prostaglandin J2

    Science.gov (United States)

    Ishino, Hidetaka; Kawahito, Yutaka; Tsubouchi, Yasunori; Kohno, Masataka; Wada, Makoto; Yamamoto, Aihiro; Hamaguchi, Masahide; Kadoya, Masatoshi; Tokunaga, Daisaku; Hojo, Tatsuya; Matsuyama, Masahide; Yoshimura, Rikio; Yoshikawa, Toshikazu

    2008-01-01

    15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) and an anti-diabetic thiazolidinedione, troglitazone (TRO) are peroxisome proliferator-activated receptor (PPAR)-γ ligands, which regulate immuno-inflammatory reactions as well as adipocyte differentiation. We previously reported that 15d-PGJ2 can suppress interleukin (IL)-1β-induced prostaglandin E2 (PGE2) synthesis in synoviocytes of rheumatoid arthritis (RA). IL-1 also stimulates PGE2 synthesis in osteoblasts by regulation of cyclooxygenase (COX)-2 and regulates osteoclastic bone resorption in various diseases such as RA and osteoporosis. In this study, we investigated the feedback mechanism of the arachidonate cascade in mouse osteoblastic cells, MC3T3-E1 cells, which differentiate into mature osteoblasts. Treatment with 15d-PGJ2 led to a significant increase in IL-1α-induced COX-2 expression and PGE2 production in a dose dependent manner. The effect of 15d-PGJ2 was stronger than that of TRO. However, it did not affect the expression of COX-1. In addition, cell viability of MC3T3-E1 cells was not changed in the condition we established. This means that 15d-PGJ2 exerts a positive feedback regulation of the arachidonate cascade of PGE2 in osteoblastic cells. These results may provide important information about the pathogenesis and treatment of bone resorption in a variety of diseases such as RA and osteoporosis. PMID:18231633

  13. Enhancement of pig embryonic implants in factor VIII KO mice: a novel role for the coagulation cascade in organ size control.

    Directory of Open Access Journals (Sweden)

    Anna Aronovich

    Full Text Available Very little is known about the mechanisms that contribute to organ size differences between species. In the present study, we used a mouse model of embryonic pig tissue implantation to define the role of host Factor VIII in controlling the final size attained by the implant. We show here that pig embryonic spleen, pancreas, and liver all grow to an increased size in mice that are deficient in the Factor VIII clotting cascade. Similar results were obtained using the transplantation model after treatment with the low molecular weight heparin derivative Clexane which markedly enhanced transplant size. Likewise, enhanced size was found upon treatment with the direct thrombin inhibitor Dabigatran, suggesting that organ size regulation might be mediated by thrombin, downstream of Factor VIII. Considering that thrombin was shown to mediate various functions unrelated to blood clotting, either directly by cleavage of protease-activated receptors (PARs or indirectly by cleaving osteopontin (OPN on stroma cells, the role of PAR1 and PAR4 antagonists as well as treatment with cleaved form of OPN (tcOPN were tested. While the former was not found to have an impact on overgrowth of embryonic pig spleen implants, marked reduction of size was noted upon treatment with the (tcOPN. Collectively, our surprising set of observations suggests that factors of the coagulation cascade have a novel role in organ size control.

  14. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic

    OpenAIRE

    Powers, William. J.; Videen, Tom O.; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S.

    2011-01-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO2) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO2, CMRglc, and other covariates as predictors of resting ...

  15. The ZONE Diet and Metabolic Control in Type 2 Diabetes.

    Science.gov (United States)

    Stulnig, Thomas M

    2015-01-01

    Obesity is associated with chronic inflammation of the adipose tissue, which contributes to obesity-associated complications such as insulin resistance and type 2 diabetes. The increased inflammatory response seems to be directly related to modern nutrition, particularly aspects of fat quality and macronutrient composition. We have recently published an observational study investigating the practicability and effects of a combined dietary intervention with increased relative protein content and low-glycemic-index carbohydrates, supplemented with omega-3 polyunsaturated fatty acids (PUFAs), on metabolic control and inflammatory parameters in real-life situations in patients with type 2 diabetes. The primary efficacy parameter was the change in HbA1c, and secondary parameters included change in systemic inflammation (measured by ultrasensitive C-reactive protein), body weight, waist circumference, fat mass, and homeostasis model assessment-insulin resistance. Counseling a protein-enriched and low-glycemic-index diet supplemented with long-chain omega-3 PUFAs in a real-life clinical setting improved glycemic control, waist circumference, and silent inflammation in overweight or obese patients with type 2 diabetes.

  16. DISTURBANCE ATTENUATION FOR UNCERTAIN NONLINEAR CASCADED SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    BI Weiping; MU Xiaowu; SUN Yuqiang

    2004-01-01

    In present paper, the disturbance attenuation problem of uncertain nonlinear cascaded systems is studied. Based on the adding one power integrator technique and recursive design, a feedback controller that solves the disturbance attenuation problem is constructed for uncertain nonlinear cascaded systems with internal stability.

  17. Perspectives in metabolic engineering: understanding cellular regulation towards the control of metabolic routes.

    Science.gov (United States)

    Zadran, Sohila; Levine, Raphael D

    2013-01-01

    Metabolic engineering seeks to redirect metabolic pathways through the modification of specific biochemical reactions or the introduction of new ones with the use of recombinant technology. Many of the chemicals synthesized via introduction of product-specific enzymes or the reconstruction of entire metabolic pathways into engineered hosts that can sustain production and can synthesize high yields of the desired product as yields of natural product-derived compounds are frequently low, and chemical processes can be both energy and material expensive; current endeavors have focused on using biologically derived processes as alternatives to chemical synthesis. Such economically favorable manufacturing processes pursue goals related to sustainable development and "green chemistry". Metabolic engineering is a multidisciplinary approach, involving chemical engineering, molecular biology, biochemistry, and analytical chemistry. Recent advances in molecular biology, genome-scale models, theoretical understanding, and kinetic modeling has increased interest in using metabolic engineering to redirect metabolic fluxes for industrial and therapeutic purposes. The use of metabolic engineering has increased the productivity of industrially pertinent small molecules, alcohol-based biofuels, and biodiesel. Here, we highlight developments in the practical and theoretical strategies and technologies available for the metabolic engineering of simple systems and address current limitations.

  18. Metabolic control of muscle blood flow during exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher

    2003-01-01

    During muscle contraction, several mechanisms regulate blood flow to ensure a close coupling between muscle oxygen delivery and metabolic demand. No single factor has been identified to constitute the primary metabolic regulator, yet there are signal transduction pathways between skeletal muscle...

  19. Factors controlling carbon metabolism and humification in different soil agroecosystems.

    Science.gov (United States)

    Doni, S; Macci, C; Peruzzi, E; Ceccanti, B; Masciandaro, G

    2014-01-01

    The aim of this study was to describe the processes that control humic carbon sequestration in soil. Three experimental sites differing in terms of management system and climate were selected: (i) Abanilla-Spain, soil treated with municipal solid wastes in Mediterranean semiarid climate; (ii) Puch-Germany, soil under intensive tillage and conventional agriculture in continental climate; and (iii) Alberese-Italy, soil under organic and conventional agriculture in Mediterranean subarid climate. The chemical-structural and biochemical soil properties at the initial sampling time and one year later were evaluated. The soils under organic (Alberese, soil cultivated with Triticum durum Desf.) and nonintensive management practices (Puch, soil cultivated with Triticum aestivum L. and Avena sativa L.) showed higher enzymatically active humic carbon, total organic carbon, humification index (B/E(3)s), and metabolic potential (dehydrogenase activity/water soluble carbon) if compared with conventional agriculture and plough-based tillage, respectively. In Abanilla, the application of municipal solid wastes stimulated the specific β-glucosidase activity (extracellular β-glucosidase activity/extractable humic carbon) and promoted the increase of humic substances with respect to untreated soil. The evolution of the chemical and biochemical status of the soils along a climatic gradient suggested that the adoption of certain management practices could be very promising in increasing SOC sequestration potential.

  20. Factors Controlling Carbon Metabolism and Humification in Different Soil Agroecosystems

    Directory of Open Access Journals (Sweden)

    S. Doni

    2014-01-01

    Full Text Available The aim of this study was to describe the processes that control humic carbon sequestration in soil. Three experimental sites differing in terms of management system and climate were selected: (i Abanilla-Spain, soil treated with municipal solid wastes in Mediterranean semiarid climate; (ii Puch-Germany, soil under intensive tillage and conventional agriculture in continental climate; and (iii Alberese-Italy, soil under organic and conventional agriculture in Mediterranean subarid climate. The chemical-structural and biochemical soil properties at the initial sampling time and one year later were evaluated. The soils under organic (Alberese, soil cultivated with Triticum durum Desf. and nonintensive management practices (Puch, soil cultivated with Triticum aestivum L. and Avena sativa L. showed higher enzymatically active humic carbon, total organic carbon, humification index (B/E3s, and metabolic potential (dehydrogenase activity/water soluble carbon if compared with conventional agriculture and plough-based tillage, respectively. In Abanilla, the application of municipal solid wastes stimulated the specific β-glucosidase activity (extracellular β-glucosidase activity/extractable humic carbon and promoted the increase of humic substances with respect to untreated soil. The evolution of the chemical and biochemical status of the soils along a climatic gradient suggested that the adoption of certain management practices could be very promising in increasing SOC sequestration potential.

  1. You Are What You Eat: Metabolic Control of Bacterial Division.

    Science.gov (United States)

    Monahan, Leigh G; Harry, Elizabeth J

    2016-03-01

    Fluctuations in nutrient availability are a fact of life for bacterial cells in the 'wild'. To survive and compete, bacteria must rapidly modulate cell-cycle processes to accommodate changing nutritional conditions and concomitant changes in cell growth. Our understanding of how this is achieved has been transformed in recent years, with cellular metabolism emerging as a central player. Several metabolic enzymes, in addition to their normal catalytic functions, have been shown to directly modulate cell-cycle processes in response to changing nutrient levels. Here we focus on cell division, the final event in the bacterial cell cycle, and discuss recent compelling evidence connecting division regulation to nutritional status and metabolic activity.

  2. Contribution of convection and diffusion to the cascade reaction kinetics of β-galactosidase/glucose oxidase confined in a microchannel.

    Science.gov (United States)

    Wu, Zeng-Qiang; Li, Zhong-Qiu; Li, Jin-Yi; Gu, Jing; Xia, Xing-Hua

    2016-05-25

    The spatial positioning of enzymes and mass transport play crucial roles in the functionality and efficiency of enzyme cascade reactions. To fully understand the mass transport regulating kinetics of enzyme cascade reactions, we investigated the contribution of convective and diffusive transports to a cascade reaction of β-galactosidase (β-Gal)/glucose oxidase (GOx) confined in a microchannel. β-Gal and GOx are assembled on two separated gold films patterned in a polydimethylsiloxane (PDMS) microchannel with a controllable distance from 50 to 100 μm. Experimental results demonstrated that the reaction yield increases with decreasing distance between two enzymes and increasing substrate flow rate. Together with the simulation results, we extracted individual reaction kinetics of the enzyme cascade reaction and found that the reaction rate catalyzed by β-Gal occurred much faster than by GOx, and thus, the β-Gal catalytic reaction showed diffusion controll, whereas the GOx catalytic reaction showed kinetic controll. Since the decrease in the enzymes distance shortens the transport length of intermediate glucose to GOx, the amount of glucose reaching GOx will be increased in the unit time, and in turn, the enzyme cascade reaction yield will be increased with decreasing the gap distance. This phenomenon is similar to the intermediates pool of tricarboxylic acid (TCA) cycle in the metabolic system. This study promotes the understanding of the metabolic/signal transduction processes and active transport in biological systems and promises to design high performance biosensors and biofuel cells systems.

  3. Metabolism

    Science.gov (United States)

    ... a particular food provides to the body. A chocolate bar has more calories than an apple, so ... acid phenylalanine, needed for normal growth and protein production). Inborn errors of metabolism can sometimes lead to ...

  4. Neuronal Shp2 tyrosine phosphatase controls energy balance and metabolism

    Science.gov (United States)

    Zhang, Eric E.; Chapeau, Emilie; Hagihara, Kazuki; Feng, Gen-Sheng

    2004-01-01

    Shp2, a Src homology 2-containing tyrosine phosphatase, has been implicated in a variety of growth factor or cytokine signaling pathways. However, it is conceivable that this enzyme acts predominantly in one pathway versus the others in a cell, depending on the cellular context. To determine the putative functions of Shp2 in the adult brain, we selectively deleted Shp2 in postmitotic forebrain neurons by crossing CaMKIIα-Cre transgenic mice with a conditional Shp2 mutant (Shp2flox) strain. Surprisingly, a prominent phenotype of the mutant (CaMKIIα-Cre:Shp2flox/flox or CaSKO) mice was the development of early-onset obesity, with increased serum levels of leptin, insulin, glucose, and triglycerides. The mutant mice were not hyperphagic but developed enlarged and steatotic liver. Consistent with previous in vitro data, we found that Shp2 down-regulates Jak2/Stat3 (signal transducer and activator of transcription 3) activation by leptin in the hypothalamus. However, Jak2/Stat3 down-regulation is offset by a dominant Shp2 promotion of the leptin-stimulated Erk pathway, leading to induction rather than suppression of leptin resistance upon Shp2 deletion in the brain. Collectively, these results suggest that a primary function of Shp2 in postmitotic forebrain neurons is to control energy balance and metabolism, and that this phosphatase is a critical signaling component of leptin receptor ObRb in the hypothalamus. Shp2 shows potential as a neuronal target for pharmaceutical sensitization of obese patients to leptin action. PMID:15520383

  5. Cascades with coupled map lattices in preferential attachment community networks

    Institute of Scientific and Technical Information of China (English)

    Cui Di; Gao Zi-You; Zhao Xiao-Mei

    2008-01-01

    In this paper,cascading failure is studied by coupled map lattice (CML) methods in preferential attachment community networks.It is found that external perturbation R is increasing with modularity Q growing by simulation.In particular,the large modularity Q can hold off the cascading failure dynamic process in community networks.Furthermore,different attack strategies also greatly affect the cascading failure dynamic process. It is particularly significant to control cascading failure process in real community networks.

  6. Socio-economic characteristics and quality of life in diabetes mellitus--relation to metabolic control.

    Science.gov (United States)

    Larsson, D; Lager, I; Nilsson, P M

    1999-06-01

    Diabetes mellitus is a chronic metabolic disease with wide implications for well-being and social life. The aim of this cross-sectional, observational study was to describe possible differences in clinical characteristics, socio-economic factors and quality of life between diabetes patients in poor and good/acceptable metabolic control, as defined by levels of glycated haemoglobin A1c. From a population-based register of diabetes patients at a clinical chemistry department, we selected 96 subjects in poor metabolic control (HbA1c > 10%), and 96 subjects in good/acceptable (HbA1c 6.5-7.5%) metabolic control, matched for sex, age and duration of diabetes. Each participant was sent a self-administered questionnaire regarding medical history, family situation and socio-economic background, as well as self-rated health based on a validated instrument (SF-36). The diabetes patients in poor metabolic control reported more retinopathy, vascular complications and nervous problems than did the patients in acceptable metabolic control. Furthermore, the group in poor metabolic control was also characterized by a lower educational level, a higher number of sick leave days or disability pension and a lower degree of physical activity. Both of the diabetic groups reported lower scorings for physical functioning, general health, vitality and mental health, than did a comparable non-diabetic group from another study. In summary, diabetic patients in poor metabolic control have a lower educational level and report more complications, nervous problems, sick leave days and disability pensions than patients in good/acceptable metabolic control. The lower degree of physical activity adds to the problems of the first group and should be the target for intervention to achieve better metabolic control.

  7. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    LENUS (Irish Health Repository)

    Burleigh, Susan C

    2011-10-18

    Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO) were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG) was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  8. Synergizing metabolic flux analysis and nucleotide sugar metabolism to understand the control of glycosylation of recombinant protein in CHO cells

    Directory of Open Access Journals (Sweden)

    Rudd Pauline M

    2011-10-01

    Full Text Available Abstract Background The glycosylation of recombinant proteins can be altered by a range of parameters including cellular metabolism, metabolic flux and the efficiency of the glycosylation process. We present an experimental set-up that allows determination of these key processes associated with the control of N-linked glycosylation of recombinant proteins. Results Chinese hamster ovary cells (CHO were cultivated in shake flasks at 0 mM glutamine and displayed a reduced growth rate, glucose metabolism and a slower decrease in pH, when compared to other glutamine-supplemented cultures. The N-linked glycosylation of recombinant human chorionic gonadotrophin (HCG was also altered under these conditions; the sialylation, fucosylation and antennarity decreased, while the proportion of neutral structures increased. A continuous culture set-up was subsequently used to understand the control of HCG glycosylation in the presence of varied glutamine concentrations; when glycolytic flux was reduced in the absence of glutamine, the glycosylation changes that were observed in shake flask culture were similarly detected. The intracellular content of UDP-GlcNAc was also reduced, which correlated with a decrease in sialylation and antennarity of the N-linked glycans attached to HCG. Conclusions The use of metabolic flux analysis illustrated a case of steady state multiplicity, where use of the same operating conditions at each steady state resulted in altered flux through glycolysis and the TCA cycle. This study clearly demonstrated that the control of glycoprotein microheterogeneity may be examined by use of a continuous culture system, metabolic flux analysis and assay of intracellular nucleotides. This system advances our knowledge of the relationship between metabolic flux and the glycosylation of biotherapeutics in CHO cells and will be of benefit to the bioprocessing industry.

  9. Estrogen-related receptor α, the molecular clock, and transcriptional control of metabolic outputs.

    Science.gov (United States)

    Giguère, V; Dufour, C R; Eichner, L J; Deblois, G; Cermakian, N

    2011-01-01

    Metabolism and circadian rhythms must be closely integrated to support the energetic needs of the organism linked to the daily timing of physiological and behavioral processes. Although components of the molecular clock can directly target some metabolic genes, the control of metabolic clock output is believed to be mediated mostly through the action of transcription factors whose patterns of expression are rhythmic in metabolic tissues. Our recent work has identified the orphan nuclear receptor estrogen-related receptor α (ERRα), a potent effector of metabolic gene networks, as a direct regulator of the molecular clock. Thus, by acting both upstream of and downstream from the molecular clock, ERRα serves as a key transcription factor linking the clock with metabolic control.

  10. Systems mapping of metabolic genes through control theory.

    Science.gov (United States)

    Liu, Guodong; Kong, Lan; Wang, Zhong; Wang, Chenguang; Wu, Rongling

    2013-06-30

    The formation of any complex phenotype involves a web of metabolic pathways in which one chemical is transformed through the catalysis of enzymes into another. Traditional approaches for mapping quantitative trait loci (QTLs) are based on a direct association analysis between DNA marker genotypes and end-point phenotypes, neglecting the mechanistic processes of how a phenotype is formed biochemically. Here, we propose a new dynamic framework for mapping metabolic QTLs (mQTLs) responsible for phenotypic formation. By treating metabolic pathways as a biological system, robust differential equations have proven to be a powerful means of studying and predicting the dynamic behavior of biochemical reactions that cause a high-order phenotype. The new framework integrates these differential equations into a statistical mixture model for QTL mapping. Since the mathematical parameters that define the emergent properties of the metabolic system can be estimated and tested for different mQTL genotypes, the framework allows the dynamic pattern of genetic effects to be quantified on metabolic capacity and efficacy across a time-space scale. Based on a recent study of glycolysis in Saccharomyces cerevisiae, we design and perform a series of simulation studies to investigate the statistical properties of the framework and validate its usefulness and utilization in practice. This framework can be generalized to mapping QTLs for any other dynamic systems and may stimulate pharmacogenetic research toward personalized drug and treatment intervention.

  11. Model -free adaptive control for cascade industrial nonlinear system%工业串联非线性系统无模型自适应控制

    Institute of Scientific and Technical Information of China (English)

    胡元胜; 张广林; 刘超; 张永亮

    2011-01-01

    A model - free adaptive control algorithm for cascade industrial nonlinear system is proposed. The controller is designed only by using I/O data of the controlled system, and the model of the controlled system is not necessary. The impact of the unmodelled dynamics of the process model is not exist. Simulation result shows that the proposed method is an effective algorithm with excellent tracking a-bility and strong robustness.%针对实际工业生产过程中存在的大量串联非线性系统,提出了一种基于紧格式线性化的串联非线性系统无模型自适应控制算法.该算法无需建立被控对象数学模型,仅用输入输出数据来设计控制器,有效避免了非建模动态问题.仿真结果表明该算法具有较强的跟踪性能和鲁棒性.

  12. Real-Time Smart Grids Control for Preventing Cascading Failures and Blackout using Neural Networks: Experimental Approach for N-1-1 Contingency

    Science.gov (United States)

    Zarrabian, Sina; Belkacemi, Rabie; Babalola, Adeniyi A.

    2016-12-01

    In this paper, a novel intelligent control is proposed based on Artificial Neural Networks (ANN) to mitigate cascading failure (CF) and prevent blackout in smart grid systems after N-1-1 contingency condition in real-time. The fundamental contribution of this research is to deploy the machine learning concept for preventing blackout at early stages of its occurrence and to make smart grids more resilient, reliable, and robust. The proposed method provides the best action selection strategy for adaptive adjustment of generators' output power through frequency control. This method is able to relieve congestion of transmission lines and prevent consecutive transmission line outage after N-1-1 contingency condition. The proposed ANN-based control approach is tested on an experimental 100 kW test system developed by the authors to test intelligent systems. Additionally, the proposed approach is validated on the large-scale IEEE 118-bus power system by simulation studies. Experimental results show that the ANN approach is very promising and provides accurate and robust control by preventing blackout. The technique is compared to a heuristic multi-agent system (MAS) approach based on communication interchanges. The ANN approach showed more accurate and robust response than the MAS algorithm.

  13. Nucleotide Metabolism and its Control in Lactic Acid Bacteria

    DEFF Research Database (Denmark)

    Kilstrup, Mogens; Hammer, Karin; Jensen, Peter Ruhdal

    2005-01-01

    Most metabolic reactions are connected through either their utilization of nucleotides or their utilization of nucleotides or their regulation by these metabolites. In this review the biosynthetic pathways for pyrimidine and purine metabolism in lactic acid bacteria are described including...... the interconversion pathways, the formation of deoxyribonucleotides and the salvage pathways for use of exogenous precursors. The data for the enzymatic and the genetic regulation of these pathways are reviewed, as well as the gene organizations in different lactic acid bacteria. Mutant phenotypes and methods...... for manipulation of nucleotide pools are also discussed. Our aim is to provide an overview of the physiology and genetics of nucleotide metabolism and its regulation that will facilitate the interpretation of data arising from genetics, metabolomics, proteomics, and transcriptomics in lactic acid bacteria....

  14. Metabolic Engineering of Chemical Defence Pathways in Plant Disease Control

    DEFF Research Database (Denmark)

    Rook, Frederik

    2016-01-01

    Plants produce a wide variety of specialized (or secondary) metabolites that function as chemical defence compounds and provide protection against microbial pathogens or herbivores. This chapter focuses on the metabolic engineering of biosynthetic pathways for plant chemical defence compounds...... with antimicrobial properties for use in crop protection. It presents an overview of the metabolic engineering efforts made in the area of plant chemical defence. For in-depth information on the characteristics of a specific class of chemical defence compounds, the reader is referred to the specialized reviews...

  15. Cerebral vascular control and metabolism in heat stress

    DEFF Research Database (Denmark)

    Bain, Anthony R; Nybo, Lars; Ainslie, Philip N

    2015-01-01

    implications and pathologies known to confound cerebral functioning during hyperthermia. A reduction in cerebral blood flow (CBF), derived primarily from a respiratory-induced alkalosis, underscores the cerebrovascular changes to hyperthermia. Arterial pressures may also become compromised because of reduced...... is in turn the primary mechanism for impaired tolerance to orthostatic challenges. Any reduction in CBF attenuates the brain's convective heat loss, while the hyperthermic-induced increase in metabolic rate increases the cerebral heat gain. This paradoxical uncoupling of CBF to metabolism increases brain...

  16. METABOLISM

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Objective: To determine the allele frequencies of genetic variants 373 Ala→Pro and 451 Arg→Gln of cholesteryl ester transfer protein (CETP) and to explore their potential impacts on serum lipid metabolism. Methods: The genotypes in CETP codon 373 and 451 in 91 German healthy students and 409 an-

  17. Applications of cascade multilevel inverters

    Institute of Scientific and Technical Information of China (English)

    彭方正; 钱照明

    2003-01-01

    Cascade multilevel inverters have been developed for electric utility applications. A cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge's dc voltage is supported by its own dc capacitor. The new inverter can: (1) generate almost sinusoidal waveform voltage while only switching one time per fundamental cycle; (2) dispense with multi-pulse inverters' transformers used in conventional utility interfaces and static var compensators; (3) enables direct parallel or series transformer-less connection to medium- and high-voltage power systems. In short, the cascade inverter is much more efficient and suitable for utility applications than traditional multi-pulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for power supply, (hybrid) electric vehicle (EV) motor drive, reactive power (var) and harmonic compensation. This paper summarizes the features, feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, var compensation, and harmonic filtering in power systems. Analytical, simulated, and experimental results demonstrated the superiority of the new inverters.

  18. Applications of cascade multilevel inverters

    Institute of Scientific and Technical Information of China (English)

    彭方正; 钱照明

    2003-01-01

    Cascade multilevel inverters have been developed for electric utility applications. A cascade M-level inverter consists of (M-1)/2 H-bridges in which each bridge's dc voltage is supported by its own de ca-pacitor. The new inverter can : ( 1 ) generate almost sinusoidal waveform voltage while only switching one timeper fundamental cycle ; (2) dispense with multi-pulse inverters' transformers used in conventional utility in-terfaces and static var compensators; (3) enables direct parallel or series transformer-less connection to medium- and high-voltage power systems. In short, the cascade inverter is much more efficient and suitable for utility applications than traditional multi-pulse and pulse width modulation (PWM) inverters. The authors have experimentally demonstrated the superiority of the new inverter for power supply, (hybrid) electric vehicle (EV) motor drive, reactive power (var) and harmonic compensation. This paper summarizes the features,feasibility, and control schemes of the cascade inverter for utility applications including utility interface of renewable energy, voltage regulation, var compensation, and harmonic filtering in power systems. Analytical,simulated, and experimental results demonstrated the superiority of the new inverters.

  19. Circadian control of metabolism and pathological consequences of clock perturbations.

    Science.gov (United States)

    Mayeuf-Louchart, Alicia; Zecchin, Mathilde; Staels, Bart; Duez, Hélène

    2017-08-02

    Most organisms have developed an autonomous time-keeping system that generates self-sustained daily fluctuations in behavior and physiological processes. These biological clocks are reset every day by light to adjust physiology to the day/night cycle generated by the rotation of the Earth. Clocks present in organs involved in glucose and lipid metabolism such as the liver, muscle, adipose tissue and pancreas are also reset by feeding cues which permits the local integration of systemic and nutritional signals to switch fuel production and utilization according to the feeding/fasting cycle. However, derangements in this finely tuned system can be induced by extended light exposure, 24/7 food availability and altered food intake patterns, repeated jet-lag and shift-working, promoting metabolic imbalances ranging from body weight gain to the development of insulin resistance and liver diseases. Here, we review recent findings on the link between the clock and metabolic fluxes to maintain whole-body homeostasis, and what clock disruption in mice has revealed about the role of the clock in metabolic regulation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  20. PGC-1 coactivators in the control of energy metabolism

    Institute of Scientific and Technical Information of China (English)

    Chang Liu; Jiandie D.Lin

    2011-01-01

    Chronic disruption of energy balance, where energy intake exceeds expenditure, is a major risk factor for the development of metabolic syndrome. The latter is characterized by a constellation of symptoms including obesity, dyslipidemia, insulin resistance, hypertension, and nonalcoholic fatty liver disease. Altered expression of genes involved in glucose and lipid metabolism as well as mitochondrial oxidative phosphorylation has been implicated in the pathogenesis of these disorders. The peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1) family of transcriptional coactivators is emerging as a hub linking nutritional and hormonal signals and energy metabolism. PGC-1а and PGC-1β are highly responsive to environmental cues and coordinate metabolic gene pro- grams through interaction with transcription factors and chromatin-remodeling proteins. PGC-1а has been implicated in the pathogenic conditions including obesity, type 2 diabetes, neurodegeneration, and cardiomyopathy, whereas PGC-1β plays an important role in plasma iipoprotein homeostasis and serves as a hepatic target for niacin, a potent hypotriglyceridemic drug. Here, we review recent advances in the identification of physiological and pathophysiological contexts involving PGC-1 coactivators, and also discuss their implications for therapeutic development.

  1. Undercover: Gene control by metabolites and metabolic enzymes

    NARCIS (Netherlands)

    J.A. van der Knaap (Jan); C.P. Verrijzer (Peter)

    2016-01-01

    textabstractTo make the appropriate developmental decisions or maintain homeostasis, cells and organisms must coordinate the expression of their genome and metabolic state. However, the molecular mechanisms that relay environmental cues such as nutrient availability to the appropriate gene expressio

  2. Metabolic Design and Control for Production in Prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, Swapnil R.; Keasling, J.D.

    2010-11-10

    Prokaryotic life on earth is manifested by its diversity and omnipresence. These microbes serve as natural sources of a large variety of compounds with the potential to serve the ever growing, medicinal, chemical and transportation needs of the human population. However, commercially viable production of these compounds can be realized only through significant improvement of the native production capacity of natural isolates. The most favorable way to achieve this goal is through the genetic manipulation of metabolic pathways that direct the production of these molecules. While random mutagenesis and screening have dominated the industrial production of such compounds in the past our increased understanding of microbial physiology over the last five decades has shifted this trend towards rational approaches for metabolic design. Major drivers of this trend include recombinant DNA technology, high throughput characterization of macromolecular cellular components, quantitative modeling for metabolic engine ring, targeted combinatorial engineering and synthetic biology. In this chapter we track the evolution of microbial engineering technologies from the black box era of random mutagenesis to the science and engineering-driven era of metabolic design.

  3. The LKB1-AMPK pathway: metabolism and growth control in tumor suppression

    Science.gov (United States)

    Shackelford, David B.; Shaw, Reuben J.

    2009-01-01

    In the past decade, studies of the human tumor suppressor LKB1 have uncovered a novel signaling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine/threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues such as liver, muscle, and adipose, a function that has made it a key therapeutic target in patients with diabetes. The connection of AMPK with several tumor suppressors suggests that therapeutic manipulation of this pathway with established diabetes drugs warrants further investigation in patients with cancer. PMID:19629071

  4. The LKB1-AMPK pathway: metabolism and growth control in tumour suppression.

    Science.gov (United States)

    Shackelford, David B; Shaw, Reuben J

    2009-08-01

    In the past decade, studies of the human tumour suppressor LKB1 have uncovered a novel signalling pathway that links cell metabolism to growth control and cell polarity. LKB1 encodes a serine-threonine kinase that directly phosphorylates and activates AMPK, a central metabolic sensor. AMPK regulates lipid, cholesterol and glucose metabolism in specialized metabolic tissues, such as liver, muscle and adipose tissue. This function has made AMPK a key therapeutic target in patients with diabetes. The connection of AMPK with several tumour suppressors suggests that therapeutic manipulation of this pathway using established diabetes drugs warrants further investigation in patients with cancer.

  5. Laser-tissue interaction of a continuous-wave 2-μm, 3-μm cascade oscillation fiber laser: sharp incision with controlled coagulation layer thickness

    Science.gov (United States)

    Arai, Tsunenori; Sumiyoshi, Tetsumi; Naruse, Kyota; Ishihara, Miya; Sato, Shunichi; Kikuchi, Makoto; Kasamatsu, Tadashi; Sekita, Hitoshi; Obara, Minoru

    2000-06-01

    We studied coagulation layer controlled incision with newly developed continuous wave 2 micrometer, 3 micrometer cascade oscillation fiber laser in vitro. Since this laser device simultaneously oscillates 2 micrometer and 3 micrometer radiation, we could change tissue interaction by arranging power ratio of 2 micrometer to 3 micrometer radiation. About one watt of total irradiation power with various power ratios was focused to extracted fresh porcine myocardium or anesthetized rabbit on an automatic moving stage to obtain line incision. Macro photograph and microscopic histology were used to observe tissue interaction phenomenon. The incised specimen showed that precise cutting groove with thin coagulation layer was attained by a 3 micrometer based radiation, meanwhile addition of 2 micrometer radiation to 3 micrometer radiation made coagulation layer thicker. A heat conduction simulator using finite-element method was used to qualitatively explain obtained coagulation layer thickness. This precise incision with controllable side coagulation layer may effective to control bleeding during incision, for instance, for skin, liver, and kidney incisions. Pure continuous wave radiation of 2 micrometer and 3 micrometer may eliminate stress wave induced tissue damage which is frequently found in Ho:YAG and/or Er:YAG tissue interactions. Moreover, sapphire fiber might offer flexible power delivery to this new laser to establish endoscopic application and/or to improved beam handling.

  6. Cascade quantum teleportation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Nan-run; GONG Li-hua; LIU Ye

    2006-01-01

    In this letter a cascade quantum teleportation scheme is proposed. The proposed scheme needs less local quantum operations than those of quantum multi-teleportation. A quantum teleportation scheme based on entanglement swapping is presented and compared with the cascade quantum teleportation scheme. Those two schemes can effectively teleport quantum information and extend the distance of quantum communication.

  7. A new generation of high-power cascade H-bridge rectifier for voltage balancing control%新一代电压平衡控制大功率级联H桥整流器

    Institute of Scientific and Technical Information of China (English)

    尹相卿

    2013-01-01

    The paper discussed control strategy of cascade rectifier which was the first part of new generation of cascade non-frequency transformer.It simplified cascade rectifier model,and established a mathematical model based on single-phase rotating coordinate system.It put forward rapid balancing control strategy for DC side capacitor voltage,which decomposed switch states desired by synthesized waveform to each cascade unit.The simulation results show that the control strategy not only can make DC side capacitor voltage balance control of each cascade unit more precise,but also can control active and reactive power more effectively.%讨论了作为新一代级联式无工频变压器第一部分的级联整流器的控制策略;简化了级联整流器的模型,并且建立了基于单相旋转坐标系的数学模型;提出了一种将合成波形所需的开关状态分解到每个级联单元的直流侧电容电压快速平衡控制策略.仿真结果表明,该控制策略不仅可以使每个级联单元直流侧电容电压平衡控制更精确,而且能更加有效地控制系统有功功率和无功功率.

  8. Reduction of DC-link Capacitor in Case of Cascade Multilevel Converters by means of Reactive Power Control

    DEFF Research Database (Denmark)

    Gohil, Ghanshyamsinh Vijaysinh; Wang, Huai; Liserre, Marco

    2014-01-01

    A method to selectively control the amount of dc link voltage ripple by processing desired reactive power by a DC/DC converter in isolated AC/DC or AC/DC/AC system is proposed. The concept can reduce the dc link capacitors used for balancing the input and output power and thereby limiting...... the voltage ripple. It allows the use of smaller dc link capacitor and hence a longer lifetime and at the same time high power density and low cost can be achieved. The isolated DC/DC converter is controlled to process the desired reactive power in addition to the active power. The control system to achieve...

  9. Metabolic syndrome and atypical antipsychotics: Possibility of prediction and control.

    Science.gov (United States)

    Franch Pato, Clara M; Molina Rodríguez, Vicente; Franch Valverde, Juan I

    Schizophrenia and other psychotic disorders are associated with high morbidity and mortality, due to inherent health factors, genetic factors, and factors related to psychopharmacological treatment. Antipsychotics, like other drugs, have side-effects that can substantially affect the physical health of patients, with substantive differences in the side-effect profile and in the patients in which these side-effects occur. To understand and identify these risk groups could help to prevent the occurrence of the undesired effects. A prospective study, with 24 months follow-up, was conducted in order to analyse the physical health of severe mental patients under maintenance treatment with atypical antipsychotics, as well as to determine any predictive parameters at anthropometric and/or analytical level for good/bad outcome of metabolic syndrome in these patients. There were no significant changes in the physical and biochemical parameters individually analysed throughout the different visits. The baseline abdominal circumference (lambda Wilks P=.013) and baseline HDL-cholesterol levels (lambda Wilks P=.000) were the parameters that seem to be more relevant above the rest of the metabolic syndrome constituents diagnosis criteria as predictors in the long-term. In the search for predictive factors of metabolic syndrome, HDL-cholesterol and abdominal circumference at the time of inclusion were selected, as such that the worst the baseline results were, the higher probability of long-term improvement. Copyright © 2016 SEP y SEPB. Publicado por Elsevier España, S.L.U. All rights reserved.

  10. Hypoglycemia in pregnant women with type 1 diabetes: predictors and role of metabolic control

    DEFF Research Database (Denmark)

    Nielsen, Lene Ringholm; Pedersen-Bjergaard, Ulrik; Thorsteinsson, Birger;

    2008-01-01

    In pregnancy with type 1 diabetes, we evaluated occurrence of mild and severe hypoglycemia and analyzed the influence of strict metabolic control, nausea, vomiting, and other potential predictors of occurrence of severe hypoglycemia.......In pregnancy with type 1 diabetes, we evaluated occurrence of mild and severe hypoglycemia and analyzed the influence of strict metabolic control, nausea, vomiting, and other potential predictors of occurrence of severe hypoglycemia....

  11. Metabolic Control and Academic Achievement over Time among Adolescents with Type 1 Diabetes

    Science.gov (United States)

    Winnick, Joel B.; Berg, Cynthia A.; Wiebe, Deborah J.; Schaefer, Barbara A.; Lei, Pui-Wa; Butner, Jonathan E.

    2017-01-01

    The relation between metabolic control (HbA1c) and achievement (grade point average [GPA]) was examined over a period of 2.5 years (every 6 months) employing a dynamical systems approach that allowed for the examination of whether HbA1c was associated with change in subsequent GPA and vice versa. Metabolic control tends to deteriorate (i.e., with…

  12. Genetic control of a cytochrome P450 metabolism-based herbicide resistance mechanism in Lolium rigidum

    OpenAIRE

    2010-01-01

    The dynamics of herbicide resistance evolution in plants are influenced by many factors, especially the biochemical and genetic basis of resistance. Herbicide resistance can be endowed by enhanced rates of herbicide metabolism because of the activity of cytochrome P450 enzymes, although in weedy plants the genetic control of cytochrome P450-endowed herbicide resistance is poorly understood. In this study we have examined the genetic control of P450 metabolism-based herbicide resistance in a w...

  13. Controls of Walker Lane Belt Pull-aparts on the Plumbing System in the Ancestral Cascades Arc, Central Sierra Nevada, California

    Science.gov (United States)

    Busby, C.; Putirka, K. D.; Renne, P. R.

    2016-12-01

    Extinct volcanic fields exposed by erosion or tectonism provide the opportunity to study structural controls on volcano-tectonic basins, vents, and plumbing systems, on a timescale of millions of years. The Miocene-Pliocene Ancestral Cascades arc in the central Sierra Nevada is spectacularly well-exposed in three dimensions over rugged topography with high structural relief. The Miocene ( 12 to 5 Ma) Sierra Crest-Little Walker volcanic center and the Miocene-Pliocene ( 6 to 4.6 Ma) Ebbetts Pass volcanic center formed in pull-apart basins in the Walker Lane belt (WLB), a NNW zone of dextral strike-slip and oblique normal faults at the western edge of the Basin and Range. The Sierra Crest-Little Walker volcanic field is as large as the active Long Valley volcanic field and the Ebbetts Pass volcanic center is as large as the active Lassen volcanic field (which also lie within the WLB). Petrographic, geochemical and geochronological data are used to understand these volcanic centers, but detailed mapping of volcanic/subvolcanic lithofacies and faults forms the core of these studies. We present a time-slice series of block diagrams that illustrate the structural controls on the Ancestral Cascades arc plumbing system in the early stages of WLB transtension. Extreme transtension in the very large Sierra Crest-Little Walker pull-apart triggered rapid ascent of low-degree partial melts, causing outpouring of high-K2O lava "flood andesites" along fissure vents that resemble flood basalt vents. These fissure vents were plumbed up NNW dextral-oblique normal faults that bound the largest graben; growth faulting relations demonstrate that the focus of subsidence shifted over the field with time synchronous with eruption from the fissure vents. Smaller, point-source vents were plumbed through faults bounding smaller NNW half grabens, as well as a series of NE-SW sinistral-oblique normal faults that define a major transfer zone. The area of maximum transtension ultimately

  14. Adipocyte Metabolic Pathways Regulated by Diet Control the Female Germline Stem Cell Lineage in Drosophila melanogaster.

    Science.gov (United States)

    Matsuoka, Shinya; Armstrong, Alissa R; Sampson, Leesa L; Laws, Kaitlin M; Drummond-Barbosa, Daniela

    2017-06-01

    Nutrients affect adult stem cells through complex mechanisms involving multiple organs. Adipocytes are highly sensitive to diet and have key metabolic roles, and obesity increases the risk for many cancers. How diet-regulated adipocyte metabolic pathways influence normal stem cell lineages, however, remains unclear. Drosophila melanogaster has highly conserved adipocyte metabolism and a well-characterized female germline stem cell (GSC) lineage response to diet. Here, we conducted an isobaric tags for relative and absolute quantification (iTRAQ) proteomic analysis to identify diet-regulated adipocyte metabolic pathways that control the female GSC lineage. On a rich (relative to poor) diet, adipocyte Hexokinase-C and metabolic enzymes involved in pyruvate/acetyl-CoA production are upregulated, promoting a shift of glucose metabolism toward macromolecule biosynthesis. Adipocyte-specific knockdown shows that these enzymes support early GSC progeny survival. Further, enzymes catalyzing fatty acid oxidation and phosphatidylethanolamine synthesis in adipocytes promote GSC maintenance, whereas lipid and iron transport from adipocytes controls vitellogenesis and GSC number, respectively. These results show a functional relationship between specific metabolic pathways in adipocytes and distinct processes in the GSC lineage, suggesting the adipocyte metabolism-stem cell link as an important area of investigation in other stem cell systems. Copyright © 2017 by the Genetics Society of America.

  15. Abscisic acid signaling is controlled by a BRANCHED1/HD-ZIP i cascade in Arabidopsis axillary buds

    NARCIS (Netherlands)

    Gonzalez-Grandio, Eduardo; Pajoro, Alice; Franco-Zorrilla, Jose M.; Tarancon, Carlos; Immink, Richard G.H.; Cubas, Pilar

    2017-01-01

    Shoot-branching patterns determine key aspects of plant life and are important targets for crop breeding. However, we are still largely ignorant of the genetic networks controlling locally themost important decision during branch development: whether the axillary bud, or branch primordium, grows out

  16. Metabolic control of resting hemispheric cerebral blood flow is oxidative, not glycolytic.

    Science.gov (United States)

    Powers, William J; Videen, Tom O; Markham, Joanne; Walter, Vonn; Perlmutter, Joel S

    2011-05-01

    Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO(2)) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO(2), CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO(2) was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO(2): arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO(2) and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.

  17. Controllability in cancer metabolic networks according to drug targets as driver nodes.

    Science.gov (United States)

    Asgari, Yazdan; Salehzadeh-Yazdi, Ali; Schreiber, Falk; Masoudi-Nejad, Ali

    2013-01-01

    Networks are employed to represent many nonlinear complex systems in the real world. The topological aspects and relationships between the structure and function of biological networks have been widely studied in the past few decades. However dynamic and control features of complex networks have not been widely researched, in comparison to topological network features. In this study, we explore the relationship between network controllability, topological parameters, and network medicine (metabolic drug targets). Considering the assumption that targets of approved anticancer metabolic drugs are driver nodes (which control cancer metabolic networks), we have applied topological analysis to genome-scale metabolic models of 15 normal and corresponding cancer cell types. The results show that besides primary network parameters, more complex network metrics such as motifs and clusters may also be appropriate for controlling the systems providing the controllability relationship between topological parameters and drug targets. Consequently, this study reveals the possibilities of following a set of driver nodes in network clusters instead of considering them individually according to their centralities. This outcome suggests considering distributed control systems instead of nodal control for cancer metabolic networks, leading to a new strategy in the field of network medicine.

  18. Control of fluxes towards antibiotics and the role of primary metabolism in production of antibiotics

    DEFF Research Database (Denmark)

    Gunnarsson, Nina; Eliasson Lantz, Anna; Nielsen, Jacob

    2004-01-01

    Yield improvements in antibiotic-producing strains have classically been obtained through random mutagenesis and screening. An attractive alternative to this strategy is the rational design of producer strains via metabolic engineering, an approach that offers the possibility to increase yields...... while avoiding the problems of by-product formation and altered morphological properties, which frequently arise in mutagenized strains. An important aspect in the design of strains with improved yields by metabolic engineering is the identification of rate-controlling enzymatic reactions...... in the metabolic network. Here we describe and discuss available methods for identification of these steps, both in antibiotic biosynthesis pathways and in the primary metabolism, which serves as the supplier of precursors and cofactors for the secondary metabolism. Finally, the importance of precursor...

  19. The EAL domain protein YciR acts as a trigger enzyme in a c-di-GMP signalling cascade in E. coli biofilm control

    Science.gov (United States)

    Lindenberg, Sandra; Klauck, Gisela; Pesavento, Christina; Klauck, Eberhard; Hengge, Regine

    2013-01-01

    C-di-GMP—which is produced by diguanylate cyclases (DGC) and degraded by specific phosphodiesterases (PDEs)—is a ubiquitous second messenger in bacterial biofilm formation. In Escherichia coli, several DGCs (YegE, YdaM) and PDEs (YhjH, YciR) and the MerR-like transcription factor MlrA regulate the transcription of csgD, which encodes a biofilm regulator essential for producing amyloid curli fibres of the biofilm matrix. Here, we demonstrate that this system operates as a signalling cascade, in which c-di-GMP controlled by the DGC/PDE pair YegE/YhjH (module I) regulates the activity of the YdaM/YciR pair (module II). Via multiple direct interactions, the two module II proteins form a signalling complex with MlrA. YciR acts as a connector between modules I and II and functions as a trigger enzyme: its direct inhibition of the DGC YdaM is relieved when it binds and degrades c-di-GMP generated by module I. As a consequence, YdaM then generates c-di-GMP and—by direct and specific interaction—activates MlrA to stimulate csgD transcription. Trigger enzymes may represent a general principle in local c-di-GMP signalling. PMID:23708798

  20. Multiple controls of oxidative metabolism in living tissues as studied by phosphorus magnetic resonance.

    Science.gov (United States)

    Chance, B; Leigh, J S; Kent, J; McCully, K; Nioka, S; Clark, B J; Maris, J M; Graham, T

    1986-12-01

    Three types of metabolic control of oxidative metabolism are observed in the various tissues that have been studied by phosphorous magnetic resonance spectroscopy. The principal control of oxidative metabolism in skeletal muscle is by ADP (or Pi/phosphocreatine). This conclusion is based upon studies of arm muscles of humans during steady-state exercise. A work-cost (Vm vs. Pi/phosphocreatine) relationship follows a Michaelis-Menten rectangular hyperbola, where Km values from 0.5 to 0.6 and Vmax values from 50 to 200 (at nearly constant pH) are found in linearized plots of the equation V/Vmax = 1/(1 + 0.6 phosphocreatine/Pi) where V is work level (which is equal to the velocity of the enzymatic reaction) and Vmax is the maximal work capacity that is a measure of the enzyme activity (E) of oxidative metabolism. Adaptation to exercise enhances the slope of the work-cost relationship and causes large changes in Vmax or E. A second metabolic control may enhance the slope of the work-cost relationship but not Vmax. For example, the initiation of exercise can lead to an improved characteristic that can be explained by 2-fold increased substrate delivery, for example, increased oxygen delivery by microcirculatory control. Cardiac tissue of the adult dog affords an example of optimal endurance performance adaptation and exhibits the steepest work-cost relationship observed and is attributed to a coordinated control of substrate delivery that may involve Ca2+ and inorganic phosphate control of NADH; control of O2 delivery may also be involved. The calculated work-cost relationship is similar to that observed in the beagle heart. The theoretical curve illustrates that the liability of multiple controls is a sharp break point in metabolic control at the end of the multiple control range--a possible cause of instability of cardiac performance at high V/Vmax.

  1. How to determine control of growth rate in a chemostat. Using metabolic control analysis to resolve the paradox

    DEFF Research Database (Denmark)

    Snoep, Jacky L.; Jensen, Peter Ruhdal; Groeneveld, Philip

    1994-01-01

    how, paradoxically, one can determine control of growth rate, of growth yield and of other fluxes in a chemostat. We develop metabolic control analysis for the chemostat. this analysis does not depend on the particular way in which specific growth rate varies with the concentration of the growth...

  2. Weight control and prevention of metabolic syndrome by green tea.

    Science.gov (United States)

    Sae-tan, Sudathip; Grove, Kimberly A; Lambert, Joshua D

    2011-08-01

    Green tea (Camellia sinensis, Theaceace) is the second most popular beverage in the world and has been extensively studied for its putative disease preventive effects. Green tea is characterized by the presence of a high concentrations of polyphenolic compounds known as catechins, with (-)-epigallocatechin-3-gallate (EGCG) being the most abundant and most well-studied. Metabolic syndrome (MetS) is a complex condition that is defined by the presence of elevated waist circumference, dysglycemia, elevated blood pressure, decrease serum high-density lipoprotein-associated cholesterol, and increased serum triglycerides. Studies in both in vitro and laboratory animal models have examined the preventive effects of green tea and EGCG against the symptoms of MetS. Overall, the results of these studies have been promising and demonstrate that green tea and EGCG have preventive effects in both genetic and dietary models of obesity, insulin resistance, hypertension, and hypercholesterolemia. Various mechanisms have been proposed based on these studies and include: modulation of dietary fat absorption and metabolism, increased glucose utilization, decreased de novo lipogenesis, enhanced vascular responsiveness, and antioxidative effects. In the present review, we discuss the current state of the science with regard to laboratory studies on green tea and MetS. We attempt to critically evaluate the available data and point out areas for future research. Although there is a considerable amount of data available, questions remain in terms of the primary mechanism(s) of action, the dose-response relationships involved, and the best way to translate the results to human intervention studies.

  3. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Rob

    2017-01-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = −0.67 and ρ = −0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  4. Carbonate buffering and metabolic controls on carbon dioxide in rivers

    Science.gov (United States)

    Stets, Edward G.; Butman, David; McDonald, Cory P.; Stackpoole, Sarah M.; DeGrandpre, Michael D.; Striegl, Robert G.

    2017-04-01

    Multiple processes support the significant efflux of carbon dioxide (CO2) from rivers and streams. Attribution of CO2 oversaturation will lead to better quantification of the freshwater carbon cycle and provide insights into the net cycling of nutrients and pollutants. CO2 production is closely related to O2 consumption because of the metabolic linkage of these gases. However, this relationship can be weakened due to dissolved inorganic carbon inputs from groundwater, carbonate buffering, calcification, and anaerobic metabolism. CO2 and O2 concentrations and other water quality parameters were analyzed in two data sets: a synoptic field study and nationwide water quality monitoring data. CO2 and O2 concentrations were strongly negatively correlated in both data sets (ρ = -0.67 and ρ = -0.63, respectively), although the correlations were weaker in high-alkalinity environments. In nearly all samples, the molar oversaturation of CO2 was a larger magnitude than molar O2 undersaturation. We used a dynamically coupled O2CO2 model to show that lags in CO2 air-water equilibration are a likely cause of this phenomenon. Lags in CO2 equilibration also impart landscape-scale differences in the behavior of CO2 between high- and low-alkalinity watersheds. Although the concept of carbonate buffering and how it creates lags in CO2 equilibration with the atmosphere is well understood, it has not been sufficiently integrated into our understanding of CO2 dynamics in freshwaters. We argue that the consideration of carbonate equilibria and its effects on CO2 dynamics are primary steps in understanding the sources and magnitude of CO2 oversaturation in rivers and streams.

  5. Evidence for a myotomal Hox/Myf cascade governing nonautonomous control of rib specification within global vertebral domains.

    Science.gov (United States)

    Vinagre, Tânia; Moncaut, Natalia; Carapuço, Marta; Nóvoa, Ana; Bom, Joana; Mallo, Moisés

    2010-04-20

    Hox genes are essential for the patterning of the axial skeleton. Hox group 10 has been shown to specify the lumbar domain by setting a rib-inhibiting program in the presomitic mesoderm (PSM). We have now produced mice with ribs in every vertebra by ectopically expressing Hox group 6 in the PSM, indicating that Hox genes are also able to specify the thoracic domain. We show that the information provided by Hox genes to specify rib-containing and rib-less areas is first interpreted in the myotome through the regional-specific control of Myf5 and Myf6 expression. This information is then transmitted to the sclerotome by a system that includes FGF and PDGF signaling to produce vertebrae with or without ribs at different axial levels. Our findings offer a new perspective of how Hox genes produce global patterns in the axial skeleton and support a redundant nonmyogenic role of Myf5 and Myf6 in rib formation.

  6. Neuroendocrinology: Electromagnetogenetic Control over Feeding and Glucose Metabolism.

    Science.gov (United States)

    Ruud, Johan; Brüning, Jens C

    2016-06-06

    Cutting-edge experiments show a new means to control the activity of specifically genetically targeted neurons in the hypothalamus using electromagnetic force. At the flip of a switch, the system bidirectionally regulates feeding behavior and glucose homeostasis, demonstrating wireless control over deep brain regions and their strong influence over energy balance.

  7. Herbal Medicines for Treating Metabolic Syndrome: A Systematic Review of Randomized Controlled Trials

    OpenAIRE

    Soobin Jang; Bo-Hyoung Jang; Youme Ko; Yui Sasaki; Jeong-Su Park; Eui-Hyoung Hwang; Yun-Kyung Song; Yong-Cheol Shin; Seong-Gyu Ko

    2016-01-01

    Objective. The aim of this systematic review is to evaluate the efficacy and safety of herbal medicines in the management of metabolic syndrome. Materials and Methods. On December 9, 2015, we searched PubMed, EMBASE, Cochrane Library, SCOPUS, AMED, CNKI, KoreaMed, KMBASE, OASIS, and J-STAGE with no restriction on language or published year. We selected randomized controlled trials that involved patients with metabolic syndrome being treated with herbal medicines as intervention. The main keyw...

  8. [Barometer of type 2 diabetes in primary care. Metabolic control, styles of life and morbidity profile].

    Science.gov (United States)

    Pérez-Manchón, David; Rodríguez-Álvarez, María Lorena; Alcívar-Arteaga, Claudia; Redondo-Pico, Mercedes; Ramos-Quirós, Elena

    2016-12-28

    Knowing the profile of cardiovascular morbidity, degree of control and lifestyles in type 2 diabetes. Randomized multicenter cross-sectional study conducted in 2015 in primary care with 129 diabetics. It included sociodemographic variables, microvascular and macrovascular complications, organic damage, comorbidity and lifestyles of smoking, exercise and adherence to Mediterranean diet. Metabolic control was assessed with the latest annual glycosylated haemoglobin. 57% were men and 43% women. Metabolic control was acceptable (HbAc1%, 7.15%) without differences by town. 74.4% had cardiovascular comorbidity and the 99.2% risk factors. 23% were smokers and 41% sedentary with a 56% adherence to Mediterranean diet. The cardiometabolic profile of diabetes includes retinopathy, peripheral arterial disease, comorbidity of hypertension and cardiovascular risk factors. Individual or group health education in self-care and healthy lifestyles can improve metabolic control. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

  9. Targeting Two Coagulation Cascade Proteases with a Bivalent Aptamer Yields a Potent and Antidote-Controllable Anticoagulant.

    Science.gov (United States)

    Soule, Erin E; Bompiani, Kristin M; Woodruff, Rebecca S; Sullenger, Bruce A

    2016-02-01

    Potent and rapid-onset anticoagulation is required for several clinical settings, including cardiopulmonary bypass surgery. In addition, because anticoagulation is associated with increased bleeding following surgery, the ability to rapidly reverse such robust anticoagulation is also important. Previously, we observed that no single aptamer was as potent as heparin for anticoagulating blood. However, we discovered that combinations of two aptamers were as potent as heparin. Herein, we sought to combine two individual anticoagulant aptamers into a single bivalent RNA molecule in an effort to generate a single molecule that retained the potent anticoagulant activity of the combination of individual aptamers. We created four bivalent aptamers that can inhibit Factor X/Xa and prothrombin/thrombin and anticoagulate plasma, as well as the combination of individual aptamers. Detailed characterization of the shortest bivalent aptamer indicates that each aptamer retains full binding and functional activity when presented in the bivalent context. Finally, reversal of this bivalent aptamer with a single antidote was explored, and anticoagulant activity could be rapidly turned off in a dose-dependent manner. These studies demonstrate that bivalent anticoagulant aptamers represent a novel and potent approach to actively and reversibly control coagulation.

  10. Dietary iron controls circadian hepatic glucose metabolism through heme synthesis.

    Science.gov (United States)

    Simcox, Judith A; Mitchell, Thomas Creighton; Gao, Yan; Just, Steven F; Cooksey, Robert; Cox, James; Ajioka, Richard; Jones, Deborah; Lee, Soh-Hyun; King, Daniel; Huang, Jingyu; McClain, Donald A

    2015-04-01

    The circadian rhythm of the liver maintains glucose homeostasis, and disruption of this rhythm is associated with type 2 diabetes. Feeding is one factor that sets the circadian clock in peripheral tissues, but relatively little is known about the role of specific dietary components in that regard. We assessed the effects of dietary iron on circadian gluconeogenesis. Dietary iron affects circadian glucose metabolism through heme-mediated regulation of the interaction of nuclear receptor subfamily 1 group d member 1 (Rev-Erbα) with its cosuppressor nuclear receptor corepressor 1 (NCOR). Loss of regulated heme synthesis was achieved by aminolevulinic acid (ALA) treatment of mice or cultured cells to bypass the rate-limiting enzyme in hepatic heme synthesis, ALA synthase 1 (ALAS1). ALA treatment abolishes differences in hepatic glucose production and in the expression of gluconeogenic enzymes seen with variation of dietary iron. The differences among diets are also lost with inhibition of heme synthesis with isonicotinylhydrazine. Dietary iron modulates levels of peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a transcriptional activator of ALAS1, to affect hepatic heme. Treatment of mice with the antioxidant N-acetylcysteine diminishes PGC-1α variation observed among the iron diets, suggesting that iron is acting through reactive oxygen species signaling.

  11. Metabolic disorders and the risk of nasopharyngeal carcinoma: a case-control study in Italy.

    Science.gov (United States)

    Zucchetto, Antonella; Taborelli, Martina; Bosetti, Cristina; Montella, Maurizio; La Vecchia, Carlo; Franchin, Gianni; Libra, Massimo; Serraino, Diego; Polesel, Jerry

    2016-07-29

    The aim of this study is to evaluate the association between metabolic disorders and the risk of nasopharyngeal carcinoma, considering different histological subtypes. Between 1992 and 2008, we carried out a multicentre case-control study in Italy. One-hundred and ninety-seven White patients with histologically confirmed nasopharyngeal carcinoma were enrolled as cases. The control group included 592 cancer-free patients, frequency matched by study centre, area of residence, sex, age and period of interview. Odds ratios (OR) and corresponding 95% confidence intervals (CI), for nasopharyngeal carcinoma according to obesity and self-reported history of other metabolic disorders, were calculated through logistic regression models adjusted for matching variables and tobacco smoking and drinking habits. Obesity (OR=1.44; 95% CI: 0.88-2.36), diabetes mellitus (OR=0.91; 95% CI: 0.42-1.98), hypertension (OR=0.79; 95% CI: 0.48-1.32), hypercholesterolaemia (OR=1.41; 95% CI: 0.84-2.35) and metabolic syndrome (i.e. at least three among the four previously cited metabolic disorders; OR=1.11; 95% CI: 0.86-1.43) were not significantly associated with the overall risk of nasopharyngeal carcinoma. However, the associations observed for diabetes mellitus, hypercholesterolaemia and metabolic syndrome were stronger among differentiated nasopharyngeal carcinomas than among undifferentiated ones. In particular, 21.7% of differentiated nasopharyngeal carcinoma cases and 7.8% of controls reported a history of metabolic syndrome (OR=3.37; 95% CI: 1.05-10.81). The results of the study indicated no overall association between metabolic disorders and nasopharyngeal carcinoma. Nonetheless, although the small sample size calls for caution in interpretation, metabolic disorders could increase the risk of differentiated nasopharyngeal carcinoma. This finding further supports a different aetiology of the two histological subtypes.

  12. Application of a controllable degron strategy for metabolic engineering

    DEFF Research Database (Denmark)

    Knuf, Christoph; Maury, Jerome; Jacobsen, Simo Abdessamad;

    2014-01-01

    , as the existing enzyme will still be active. We present a strategy for down-regulation that acts on the protein level and which can therefore be controlled in a more precise manner than the hitherto reported strategies. As a case study we show the action of the degron strategy for controlling the pools...... terpenoids, can be produced from intermediates of this pathway. Different strategies have been applied in order to down-regulate the expression of enzymes involved in the mevalonate pathway. All these strategies work on the transcriptional level. This leads to a delay of the actual regulation...

  13. Diabetes in children and adolescents from ethnic minorities: barriers to education, treatment and good metabolic control

    DEFF Research Database (Denmark)

    Povlsen, Lene; Olsen, Birthe; Ladelund, Steen

    2005-01-01

    AIM: This paper reports an investigation to establish whether metabolic control is different in children and adolescents from ethnic minorities with type 1 diabetes compared with young Danish patients, and to learn about factors affecting their opportunities to achieve good metabolic control....... BACKGROUND: The prevalence of diabetes in children and adolescents from ethnic minorities in Denmark is increasing. Having a different ethnic background has frequently been described as a risk factor for poor metabolic control, but whether the risk is represented by the ethnicity and immigration itself...... or in combination with other factors is unclear. METHODS: The study included data (gender, age, diabetes duration HbA(1c), number of incidents of severe hypoglycaemia and ketoacidosis) from a national register including 919 Danish and 58 children and adolescents from ethnic minorities, questionnaires to all 20...

  14. Emergence of event cascades in inhomogeneous networks

    Science.gov (United States)

    Onaga, Tomokatsu; Shinomoto, Shigeru

    2016-09-01

    There is a commonality among contagious diseases, tweets, and neuronal firings that past events facilitate the future occurrence of events. The spread of events has been extensively studied such that the systems exhibit catastrophic chain reactions if the interaction represented by the ratio of reproduction exceeds unity; however, their subthreshold states are not fully understood. Here, we report that these systems are possessed by nonstationary cascades of event-occurrences already in the subthreshold regime. Event cascades can be harmful in some contexts, when the peak-demand causes vaccine shortages, heavy traffic on communication lines, but may be beneficial in other contexts, such that spontaneous activity in neural networks may be used to generate motion or store memory. Thus it is important to comprehend the mechanism by which such cascades appear, and consider controlling a system to tame or facilitate fluctuations in the event-occurrences. The critical interaction for the emergence of cascades depends greatly on the network structure in which individuals are connected. We demonstrate that we can predict whether cascades may emerge, given information about the interactions between individuals. Furthermore, we develop a method of reallocating connections among individuals so that event cascades may be either impeded or impelled in a network.

  15. Emerging roles of the intestine in control of cholesterol metabolism

    NARCIS (Netherlands)

    Kruit, Janine K.; Groen, Albert K.; van Berkel, Theo J.; Kuipers, Folkert

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis, clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor t

  16. Emerging roles of the intestine in control of cholesterol metabolism

    NARCIS (Netherlands)

    Kruit, Janine K.; Groen, Albert K.; van Berkel, Theo J.; Kuipers, Folkert

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis, clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor

  17. Behavioural factors related to metabolic control in patients with phenylketonuria

    NARCIS (Netherlands)

    Crone, MR; van Spronsen, FJ; Oudshoorn, K; Bekhof, J; van Rijn, G; Verkerk, PH

    2005-01-01

    Background. The objective of this study was to determine the importance of parental factors possibly related to dietary control in early and continuously treated patients with phenylketonuria (PKU). Methods. A questionnaire was disseminated among parents of 238 patients with PKU born after the natio

  18. Metabolic Control with Insulin Pump Therapy: Preliminary Experience

    Directory of Open Access Journals (Sweden)

    Shang-Ren Hsu

    2008-07-01

    Conclusion: Our preliminary experience demonstrated the effectiveness of insulin pump therapy for both type 1 and type 2 diabetic patients. The reduction in their HbA1C values was both statistically and clinically significant. This treatment should be considered for patients poorly controlled by subcutaneous insulin injection therapy.

  19. Designing RNA-based genetic control systems for efficient production from engineered metabolic pathways.

    Science.gov (United States)

    Stevens, Jason T; Carothers, James M

    2015-02-20

    Engineered metabolic pathways can be augmented with dynamic regulatory controllers to increase production titers by minimizing toxicity and helping cells maintain homeostasis. We investigated the potential for dynamic RNA-based genetic control systems to increase production through simulation analysis of an engineered p-aminostyrene (p-AS) pathway in E. coli. To map the entire design space, we formulated 729 unique mechanistic models corresponding to all of the possible control topologies and mechanistic implementations in the system under study. Two thousand sampled simulations were performed for each of the 729 system designs to relate the potential effects of dynamic control to increases in p-AS production (total of 3 × 10(6) simulations). Our analysis indicates that dynamic control strategies employing aptazyme-regulated expression devices (aREDs) can yield >10-fold improvements over static control. We uncovered generalizable trends in successful control architectures and found that highly performing RNA-based control systems are experimentally tractable. Analyzing the metabolic control state space to predict optimal genetic control strategies promises to enhance the design of metabolic pathways.

  20. Depression, disturbed eating behavior, and metabolic control in teenage girls with type 1 diabetes.

    Science.gov (United States)

    Colton, Patricia A; Olmsted, Marion P; Daneman, Denis; Rodin, Gary M

    2013-08-01

    Depression and disturbed eating behavior (DEB) are more common in girls with type 1 diabetes (T1D) than in the general population, and may negatively affect metabolic control. To examine the relationship among depression, DEB, and metabolic control in teenage girls with T1D. Metabolic control, body mass index and interview-ascertained symptoms of depression, and DEB were assessed twice in 98 girls with T1D, 9-14 y at baseline and 5 yr later at 14-18 yr. At year 5, 12.2% of girls reported current depressive symptoms, 49.0% reported current DEB, and 13.3% had a full or subthreshold eating disorder (ED). Eating Disorder Examination score was higher in girls with depression (1.4 ± 1.3 vs. 0.5 ± 0.7; p = 0.03), and 75.0% of girls with depression also endorsed DEB vs. 45.3% of girls without depression (p = 0.05). Girls with an ED were at high risk for depressive symptoms; 69.2% reported depressive symptoms vs. 22.0% of girls with no DEB (p = 0.004). Metabolic control was not significantly associated with either depression or DEB in this cohort. A regression model using baseline and year 5 depression and DEB to predict year 5 hemoglobin A1c was not significant overall. Depression and DEB were common and frequently concurrent in this cohort. It was encouraging that poor metabolic control was not yet strongly associated with either depression or DEB. Early detection and treatment may help to prevent the development of entrenched difficulties in this triad of mood, eating behavior, and metabolic control in a vulnerable population. © 2013 John Wiley & Sons A/S.

  1. Metabolic Control and Illness Perceptions in Adolescents with Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Line Wisting

    2016-01-01

    Full Text Available Background. Disturbed eating behavior and psychosocial variables have been found to influence metabolic control, but little is known about how these variables interact or how they influence metabolic control, separately and combined. Objective. To explore associations between metabolic control (measured by HbA1c and eating disorder psychopathology, coping strategies, illness perceptions, and insulin beliefs in adolescents with type 1 diabetes. Methods. A total of 105 patients (41.9% males with type 1 diabetes (12–20 years were interviewed with the Child Eating Disorder Examination. In addition, self-report psychosocial questionnaires were completed. Clinical data, including HbA1c, was obtained from the Norwegian Childhood Diabetes Registry. Results. Significant gender differences were demonstrated. Among females, HbA1c correlated significantly with eating restriction (.29, p < .05, the illness perception dimensions consequences, personal control, coherence, and concern (ranging from .33 to .48, and the coping strategy ventilating negative feelings (−.26, p < .05. Illness perception personal control contributed significantly to HbA1c in a regression model, explaining 23% of the variance among females (β .48, p < .001. None of the variables were significantly associated with HbA1c among males. Conclusions. Illness perceptions appear to be important contributors to metabolic control in females, but not males, with type 1 diabetes.

  2. Synthetic control of a fitness tradeoff in yeast nitrogen metabolism

    OpenAIRE

    Lee Jack J; Beisel Chase L; Hoff Kevin G; Bayer Travis S; Smolke Christina D

    2009-01-01

    Abstract Background Microbial communities are involved in many processes relevant to industrial and medical biotechnology, such as the formation of biofilms, lignocellulosic degradation, and hydrogen production. The manipulation of synthetic and natural microbial communities and their underlying ecological parameters, such as fitness, evolvability, and variation, is an increasingly important area of research for synthetic biology. Results Here, we explored how synthetic control of an endogeno...

  3. Investigating Metabolic Control of Persister Formation in Biofilms

    Science.gov (United States)

    2013-10-01

    consumed substrate) and output (cyto- chrome activity). However, the network between input and out- put in persisters is not delineated with this assay...Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health...sorting. As controls, 1-ml samples were first incubated with car- bonyl cyanide m-chlorophenylhydrazone (CCCP) or potassium cyanide (KCN) at 10 M or 1 mM

  4. Critical Mandelbrot Cascades

    Science.gov (United States)

    Barral, Julien; Kupiainen, Antti; Nikula, Miika; Saksman, Eero; Webb, Christian

    2014-01-01

    We study Mandelbrot's multiplicative cascade measures at the critical temperature. As has been recently shown by Barral et al. (C R Acad Sci Paris Ser I 350:535-538, 2012), an appropriately normalized sequence of cascade measures converges weakly in probability to a nontrivial limit measure. We prove that these limit measures have no atoms and give bounds for the modulus of continuity of the cumulative distribution function of the measure. Using the earlier work of Barral and Seuret (Adv Math 214:437-468, 2007), we compute the multifractal spectrum of the measures. We also extend the result of Benjamini and Schramm (Commun Math Phys 289:653-662, 2009), in which the KPZ formula from quantum gravity is validated for the high temperature cascade measures, to the critical and low temperature cases.

  5. Quadrant Cascaded Multilevel Converter and Rectifier Control%4象限级联型多电平变换器及其整流器控制

    Institute of Scientific and Technical Information of China (English)

    孙炳海; 李永东; 王剑

    2011-01-01

    In the power units of cascaded multilevel converters, replacing the diode rectifier with PWM rectifier can make the converter have the regenerative ability; using the leak inductance as the filter reactor of the PWM rectifier can reduce the volume and cost of the converter; the phase-shift secondary side of the transformer can eliminate the current harmonics caused by the single power unit, restraining the grid side harmonic especially the low order harmonic. In the control scheme PLL is employed to track the grid voltage's phase and frequency. The PIR control strategy of the PWM rectifier is used to maintain the DC-link voltage stable when feeding the single-phase inverter. The mathematic model of the PWM rectifier, its orientation method and the PIR current control strategy were introduced. The experiment results verify that the converter can achieve the regenerative ability when operating in the accelerating and decelerating of electrical machines.%在级联型多电平变换器的功率单元中,用PWM整流器替代二极管整流器,可以实现能量的双向流动;利用隔离变压器的副边漏抗代替整流器的输入电抗器,可以减少变换器的体积和成本;隔离变压器的副边绕组移相消除了由单个功率单元所引起的谐波电流,抑制了网侧谐波尤其是低次谐波的产生.在整流器控制中使用锁相环对电网的相位和频率跟踪,采用PWM整流器的PIR电流控制策略,有利于在整流器接单相逆变负载的情况下维持母线电压的稳定.给出了PWM整流器的数学模型、定向策略及PIR控制策略,通过实验验证了新型整流器及其控制策略在电机加速减速过程中能够实现能量回馈.

  6. Metabolism

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    4.1 Nutrition imbalance 2006024 Effect of multiple micronutrients supplementation on anti - oxidative activity and oxidized DNA damage of lymphocytes in children ZHANG Ming ( 张明), Nutrit Dept, Weifang People Hosp, Weifang 261041. Chin J Epidemiol 2005 ;26(4) :268 -272. Objective:To examine the effect of multiple micronutrients supplementation on anti - oxidative activity and decreasing oxidized DNA damage of lymphocytes in Chinese children. Methods:82 healthy children in rural areas, aged 9-11 years, were selected and randomized into group receiving supplements and control group with 41 in

  7. Role of glycolytic intermediate in regulation: Improving lycopene production in Escherichia coli by engineering metabolic control

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, W.R.; Liao, J.C.

    2001-06-01

    Metabolic engineering in the postgenomic era is expected to benefit from a full understanding of the biosynthetic capability of microorganisms as a result of the progress being made in bioinformatics and functional genomics. The immediate advantage of such information is to allow the rational design of novel pathways and the elimination of native reactions that are detrimental or unnecessary for the desired purpose. However, with the ability to manipulate metabolic pathways becoming more effective, metabolic engineering will need to face a new challenge: the reengineering of the regulatory hierarchy that controls gene expression in those pathways. In addition to constructing the genetic composition of a metabolic pathway, they propose that it will become just as important to consider the dynamics of pathways gene expression. It has been widely observed that high-level induction of a recombinant protein or pathway leads to growth retardation and reduced metabolic activity. These phenotypic characteristics result from the fact that the constant demands of production placed upon the cell interfere with its changing requirements for growth. They believe that this common situation in metabolic engineering can be alleviated by designing a dynamic controller that is able to sense the metabolic state of the cell and regulate the expression of the recombinant pathway accordingly. This approach, which is termed metabolic control engineering, involves redesigning the native regulatory circuits and applying them to the recombinant pathway. The general goal of such an effort will be to control the flux to the recombinant pathway adaptively according to the cell's metabolic state. The dynamically controlled recombinant pathway can potentially lead to enhanced production, minimized growth retardation, and reduced toxic by-product formation. The regulation of gene expression in response to the physiological state is also essential to the success of gene therapy. Here they

  8. Synthetic control of a fitness tradeoff in yeast nitrogen metabolism

    Directory of Open Access Journals (Sweden)

    Lee Jack J

    2009-01-01

    Full Text Available Abstract Background Microbial communities are involved in many processes relevant to industrial and medical biotechnology, such as the formation of biofilms, lignocellulosic degradation, and hydrogen production. The manipulation of synthetic and natural microbial communities and their underlying ecological parameters, such as fitness, evolvability, and variation, is an increasingly important area of research for synthetic biology. Results Here, we explored how synthetic control of an endogenous circuit can be used to regulate a tradeoff between fitness in resource abundant and resource limited environments in a population of Saccharomyces cerevisiae. We found that noise in the expression of a key enzyme in ammonia assimilation, Gdh1p, mediated a tradeoff between growth in low nitrogen environments and stress resistance in high ammonia environments. We implemented synthetic control of an endogenous Gdh1p regulatory network to construct an engineered strain in which the fitness of the population was tunable in response to an exogenously-added small molecule across a range of ammonia environments. Conclusion The ability to tune fitness and biological tradeoffs will be important components of future efforts to engineer microbial communities.

  9. 级联式有源电力滤波器控制策略及实验研究%Experiment studies and control method of high power acitve power filter using cascaded multilevel converter

    Institute of Scientific and Technical Information of China (English)

    陈敏洁; 陈峻岭; 李耀华; 王平

    2014-01-01

    针对由级联式多电平变换器为主电路的有源电力滤波器,其主电路中直流电容相互独立,如果没有有效控制措施,这些独立的电容电压会产生不平衡,严重威胁装置的安全、稳定运行。本论文提出一种有效控制策略,不仅具有良好的补偿效果,而且保证了主电路中各级联单元直流侧电容电压恒定和均衡。为了验证所提控制方法和控制策略,本文搭建了两级级联式有源电力滤波器,实验结果表明,该系统具有良好的滤波性能,同时也保证了各级联单元直流侧电容电压恒定和均衡,进一步表明本文所提方法的有效性和正确性。%High⁃power applications of cascaded multilevel inverter to active power filters ( APF) is hindered by the problem of keeping capacitor voltage balance while retaining good filtering performances. This paper proposes a no⁃vel control method with capacitor voltage balancing control for high power active power filters ( APF) using casca⁃ded multilevel converter. This method not only can balance the capacitor voltages of cascaded multilevel converter using for APF, but also has the better filtering characters. Firstly, the system topology of APF using cascaded mul⁃tilevel converter is described in detail. Secondly, the control method of APF using cascaded multilevel converter is discussed. Thirdly, a laboratory prototype of the APF based on five⁃level cascaded multilevel inverter is built, rated at 100kVA, to verify the capacitors voltage regulation and the harmonic filtering performance. Lastly, the experi⁃mental waveforms show that good filtering characteristics of the APF are achieved and the capacitor voltage is also controlled and balanced by using the proposed control methods.

  10. Tunable All-Optical Wavelength Conversion Based on Cascaded SHG/DFG in a Ti:PPLN Waveguide Using a Single CW Control Laser

    DEFF Research Database (Denmark)

    Hu, Hao; Nouroozi, Rahman; Wang, Wenrui

    2012-01-01

    Tunable all-optical wavelength conversion (AOWC) of a 40-Gb/s RZ-OOK data signal based on cascaded second-harmonic generation (SHG) and difference-frequency generation (DFG) in a Ti:PPLN waveguide is demonstrated. Error-free performances with negligible power penalty are achieved for the waveleng...

  11. [Stages of grief in diabetes and metabolic control].

    Science.gov (United States)

    Rodríguez-Moctezuma, José Raymundo; López-Delgado, María Elisa; Ortiz-Aguirre, Alma Rosa; Jiménez-Luna, Jorge; López-Ocaña, Luis Rafael; Chacón-Sánchez, Jesús

    2015-01-01

    Introducción: el objetivo de este artículo es identificar las etapas del duelo y su asociación con el control metabólico en pacientes diabéticos tipo 2. Métodos: se incluyeron 186 sujetos diabéticos, de ambos sexos, sin pérdida reciente de un ser querido ni enfermedades terminales. Se les aplicó un instrumento validado que exploró las etapas del duelo (negación, ira/incredulidad, negociación, depresión, y aceptación). Se midió: IMC, perímetro de cintura, niveles promedio de glucosa, colesterol y triglicéridos en los últimos 6 meses. Resultados: las asociaciones entre las etapas del duelo y las variables clínicas mostraron que en la negación, el IMC es mayor 33.1 ± 6.2 contra 28.9 ± 4.6 con p = 0.001; en etapa de incredulidad, la glucemia es mayor 190 ± 67 frente a 16 ± 51 con p tiempo de diagnóstico 13.3 ± 8.9 frente a 9.4 ± 7.1 años, con p < 0.05 y con el nivel de glucemia de 198.9 ± 60 frente a 164 ± 51 mg/dL con p = 0.001. Conclusiones: existen asociaciones lógicas entre variables clínicas y etapas del duelo. Se debe identificar el duelo como un elemento adicional en la evaluación de pacientes con diabetes y establecer estrategias que mejoren la adherencia al tratamiento y el control metabólico.

  12. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion.

    Science.gov (United States)

    Weiner, I David; Mitch, William E; Sands, Jeff M

    2015-08-07

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance.

  13. Multifunctional Cascaded Metamaterials: Integrated Transmitarrays

    Science.gov (United States)

    Elsakka, Amr A.; Asadchy, Viktar S.; Faniayeu, Ihar A.; Tcvetkova, Svetlana N.; Tretyakov, Sergei A.

    2016-10-01

    Control of electromagnetic waves using engineered materials is very important in a wide range of applications, therefore there is always a continuous need for new and more efficient solutions. Known natural and artificial materials and surfaces provide a particular functionality in the frequency range they operate but cast a "shadow" and produce reflections at other frequencies. Here, we introduce a concept of multifunctional engineered materials that possess different predetermined functionalities at different frequencies. Such response can be accomplished by cascading metasurfaces (thin composite layers) that are designed to perform a single operation at the desired frequency and are transparent elsewhere. Previously, out-of-band transparent metasurfaces for control over reflection and absorption were proposed. In this paper, to complete the full set of functionalities for wave control, we synthesize transmitarrays that tailor transmission in a desired way, being "invisible" beyond the operational band. The designed transmitarrays for wavefront shaping and anomalous refraction are tested numerically and experimentally. To demonstrate our concept of multifunctional engineered materials, we have designed a cascade of three metasurfaces that performs three different functions for waves at different frequencies. Remarkably, applied to volumetric metamaterials, our concept can enable a single composite possessing desired multifunctional response.

  14. Maternal and embryonic control of uterine sphingolipid-metabolizing enzymes during murine embryo implantation.

    Science.gov (United States)

    Kaneko-Tarui, Tomoko; Zhang, Ling; Austin, Kathleen J; Henkes, Luiz E; Johnson, Joshua; Hansen, Thomas R; Pru, James K

    2007-10-01

    During early gestation in invasively implanting species, the uterine stromal compartment undergoes dramatic remodeling, defined by the differentiation of stromal fibroblast cells into decidual cells. Lipid signaling molecules from a number of pathways are well-established functional components of this decidualization reaction. Because of a correlation in the events that transpire in the uterus during early implantation with known functions of bioactive sphingolipid metabolites established from studies in other organ systems, we hypothesized that uterine sphingolipid metabolism would change during implantation. By a combination of Northern blot, Western blot, and immunohistochemical analyses, we establish that enzymes at each of the major catalytic steps in the sphingolipid cascade become transcriptionally up-regulated in the uterus during decidualization. Each of the enzymes analyzed was up-regulated from Days of Pregnancy (DOP) 4.5-7.5. When comparing embryo-induced decidualization (decidual) with mechanically induced decidualization (deciduomal), sphingomyelin phosphodiesterase 1 (Smpd1) mRNA and sphingosine kinase 1 (SPHK1) protein were shown to be dually regulated in the endometrium by both maternal and embryonic factors. As measured by the diacyl glycerol kinase assay, ceramide levels rose in parallel with Smpd1 gene expression, suggesting that elevated transcription of sphingolipid enzymes results in heightened catalytic activity of the pathway. Altogether, these findings place sphingolipids on a growing list of lipid signaling molecules that become increasingly present at the maternal-embryonic interface.

  15. Emerging roles of the intestine in control of cholesterol metabolism

    Institute of Scientific and Technical Information of China (English)

    Janine K Kruit; Albert K Groen; Theo J van Berkel; Folkert Kuipers

    2006-01-01

    The liver is considered the major "control center" for maintenance of whole body cholesterol homeostasis. This organ is the main site for de novo cholesterol synthesis,clears cholesterol-containing chylomicron remnants and low density lipoprotein particles from plasma and is the major contributor to high density lipoprotein (HDL; good cholesterol) formation. The liver has a central position in the classical definition of the reverse cholesterol transport pathway by taking up peripheryderived cholesterol from lipoprotein particles followed by conversion into bile acids or its direct secretion into bile for eventual removal via the feces. During the past couple of years, however, an additional important role of the intestine in maintenance of cholesterol homeostasis and regulation of plasma cholesterol levels has become apparent. Firstly, molecular mechanisms of cholesterol absorption have been elucidated and novel pharmacological compounds have been identified that interfere with the process and positively impact plasma cholesterol levels. Secondly, it is now evident that the intestine itself contributes to fecal neutral sterol loss as a cholesterol-secreting organ. Finally, very recent work has unequivocally demonstrated that the intestine contributes significantly to plasma HDL cholesterol levels.Thus, the intestine is a potential target for novel antiatherosclerotic treatment strategies that, in addition to interference with cholesterol absorption, modulate direct cholesterol excretion and plasma HDL cholesterol levels.

  16. Control of metabolic homeostasis by stress signaling is mediated by the lipocalin NLaz.

    Directory of Open Access Journals (Sweden)

    Julie Hull-Thompson

    2009-04-01

    Full Text Available Metabolic homeostasis in metazoans is regulated by endocrine control of insulin/IGF signaling (IIS activity. Stress and inflammatory signaling pathways--such as Jun-N-terminal Kinase (JNK signaling--repress IIS, curtailing anabolic processes to promote stress tolerance and extend lifespan. While this interaction constitutes an adaptive response that allows managing energy resources under stress conditions, excessive JNK activity in adipose tissue of vertebrates has been found to cause insulin resistance, promoting type II diabetes. Thus, the interaction between JNK and IIS has to be tightly regulated to ensure proper metabolic adaptation to environmental challenges. Here, we identify a new regulatory mechanism by which JNK influences metabolism systemically. We show that JNK signaling is required for metabolic homeostasis in flies and that this function is mediated by the Drosophila Lipocalin family member Neural Lazarillo (NLaz, a homologue of vertebrate Apolipoprotein D (ApoD and Retinol Binding Protein 4 (RBP4. Lipocalins are emerging as central regulators of peripheral insulin sensitivity and have been implicated in metabolic diseases. NLaz is transcriptionally regulated by JNK signaling and is required for JNK-mediated stress and starvation tolerance. Loss of NLaz function reduces stress resistance and lifespan, while its over-expression represses growth, promotes stress tolerance and extends lifespan--phenotypes that are consistent with reduced IIS activity. Accordingly, we find that NLaz represses IIS activity in larvae and adult flies. Our results show that JNK-NLaz signaling antagonizes IIS and is critical for metabolic adaptation of the organism to environmental challenges. The JNK pathway and Lipocalins are structurally and functionally conserved, suggesting that similar interactions represent an evolutionarily conserved system for the control of metabolic homeostasis.

  17. Control of metabolic homeostasis by stress signaling is mediated by the lipocalin NLaz.

    Science.gov (United States)

    Hull-Thompson, Julie; Muffat, Julien; Sanchez, Diego; Walker, David W; Benzer, Seymour; Ganfornina, Maria D; Jasper, Heinrich

    2009-04-01

    Metabolic homeostasis in metazoans is regulated by endocrine control of insulin/IGF signaling (IIS) activity. Stress and inflammatory signaling pathways--such as Jun-N-terminal Kinase (JNK) signaling--repress IIS, curtailing anabolic processes to promote stress tolerance and extend lifespan. While this interaction constitutes an adaptive response that allows managing energy resources under stress conditions, excessive JNK activity in adipose tissue of vertebrates has been found to cause insulin resistance, promoting type II diabetes. Thus, the interaction between JNK and IIS has to be tightly regulated to ensure proper metabolic adaptation to environmental challenges. Here, we identify a new regulatory mechanism by which JNK influences metabolism systemically. We show that JNK signaling is required for metabolic homeostasis in flies and that this function is mediated by the Drosophila Lipocalin family member Neural Lazarillo (NLaz), a homologue of vertebrate Apolipoprotein D (ApoD) and Retinol Binding Protein 4 (RBP4). Lipocalins are emerging as central regulators of peripheral insulin sensitivity and have been implicated in metabolic diseases. NLaz is transcriptionally regulated by JNK signaling and is required for JNK-mediated stress and starvation tolerance. Loss of NLaz function reduces stress resistance and lifespan, while its over-expression represses growth, promotes stress tolerance and extends lifespan--phenotypes that are consistent with reduced IIS activity. Accordingly, we find that NLaz represses IIS activity in larvae and adult flies. Our results show that JNK-NLaz signaling antagonizes IIS and is critical for metabolic adaptation of the organism to environmental challenges. The JNK pathway and Lipocalins are structurally and functionally conserved, suggesting that similar interactions represent an evolutionarily conserved system for the control of metabolic homeostasis.

  18. Cascaded Poisson processes

    Science.gov (United States)

    Matsuo, Kuniaki; Saleh, Bahaa E. A.; Teich, Malvin Carl

    1982-12-01

    We investigate the counting statistics for stationary and nonstationary cascaded Poisson processes. A simple equation is obtained for the variance-to-mean ratio in the limit of long counting times. Explicit expressions for the forward-recurrence and inter-event-time probability density functions are also obtained. The results are expected to be of use in a number of areas of physics.

  19. Cognitive Maturity, Stressful Events and Metabolic Control in Adolescents with Diabetes.

    Science.gov (United States)

    Ingersoll, Gary M.; And Others

    Management of insulin dependent diabetes mellitus (IDDM) is a complex task that requires the adolescent with IDDM recognize the interaction between diet, exercise, stress, emotions, and insulin dosage. With regularity, however, adolescents with IDDM are shown to be in less good metabolic control than younger children or young adults. The study…

  20. Low triglyceride levels are associated with a better metabolic control in patients with type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Alcantara Leticia M

    2011-09-01

    Full Text Available Abstract Background Although it is well known in the literature that high triglyceride serum (TG levels can jeopardize the metabolic control, little is known about the influence of low TG on type 1 diabetes patients (T1D. The aim of this study is to investigate the distribution of TG serum levels in individuals with T1D and its relationship with metabolic control. Findings We reviewed the medical charts of 180 patients with T1D, who were classified in groups according to TG levels: 1 low (below 50 mg/dL; 2 normal (50-150 mg/dL; 3 high (above 150 mg/dL. TG were low in 21.1% (n = 38; group 1, normal in 68.6% (n = 123; group 2 and high in 10.6% (n = 19; group 3. High TG was associated with a poor metabolic control (p Conclusion TG lower than 50 mg/dL was common and might be associated with a better metabolic control in patients with T1D, although it is not clear whether the former is the cause or consequence for the latter.

  1. Herbal Medicines for Treating Metabolic Syndrome: A Systematic Review of Randomized Controlled Trials

    Directory of Open Access Journals (Sweden)

    Soobin Jang

    2016-01-01

    Full Text Available Objective. The aim of this systematic review is to evaluate the efficacy and safety of herbal medicines in the management of metabolic syndrome. Materials and Methods. On December 9, 2015, we searched PubMed, EMBASE, Cochrane Library, SCOPUS, AMED, CNKI, KoreaMed, KMBASE, OASIS, and J-STAGE with no restriction on language or published year. We selected randomized controlled trials that involved patients with metabolic syndrome being treated with herbal medicines as intervention. The main keywords were “Chinese herbal medicines”, “metabolic syndrome”, and “randomized controlled trials”. Herbal substances which were not based on East Asian medical theory, combination therapy with western medicines, and concurrent diseases other than metabolic syndrome were excluded. The risk of bias was assessed by Cochrane’s “Risk of Bias” tool. The protocol or review was registered in PROSPERO (an international prospective register of systematic reviews (CRD42014006842. Results. From 1,098 articles, 12 RCTs were included in this review: five trials studied herbal medicines versus a placebo or no treatment, and seven trials studied herbal medicines versus western medicines. Herbal medicines were effective on decreasing waist circumference, blood glucose, blood lipids, and blood pressure. Conclusion. This study suggests the possibility that herbal medicines can be complementary and alternative medicines for metabolic syndrome.

  2. Herbal Medicines for Treating Metabolic Syndrome: A Systematic Review of Randomized Controlled Trials.

    Science.gov (United States)

    Jang, Soobin; Jang, Bo-Hyoung; Ko, Youme; Sasaki, Yui; Park, Jeong-Su; Hwang, Eui-Hyoung; Song, Yun-Kyung; Shin, Yong-Cheol; Ko, Seong-Gyu

    2016-01-01

    Objective. The aim of this systematic review is to evaluate the efficacy and safety of herbal medicines in the management of metabolic syndrome. Materials and Methods. On December 9, 2015, we searched PubMed, EMBASE, Cochrane Library, SCOPUS, AMED, CNKI, KoreaMed, KMBASE, OASIS, and J-STAGE with no restriction on language or published year. We selected randomized controlled trials that involved patients with metabolic syndrome being treated with herbal medicines as intervention. The main keywords were "Chinese herbal medicines", "metabolic syndrome", and "randomized controlled trials". Herbal substances which were not based on East Asian medical theory, combination therapy with western medicines, and concurrent diseases other than metabolic syndrome were excluded. The risk of bias was assessed by Cochrane's "Risk of Bias" tool. The protocol or review was registered in PROSPERO (an international prospective register of systematic reviews) (CRD42014006842). Results. From 1,098 articles, 12 RCTs were included in this review: five trials studied herbal medicines versus a placebo or no treatment, and seven trials studied herbal medicines versus western medicines. Herbal medicines were effective on decreasing waist circumference, blood glucose, blood lipids, and blood pressure. Conclusion. This study suggests the possibility that herbal medicines can be complementary and alternative medicines for metabolic syndrome.

  3. [Dynamic variance of intracellular metabolic energies under rhythmical control for dissolved oxygen in PHB mixed cultivation].

    Science.gov (United States)

    Qian, Z W; Tohyama, M; Hua, Q; Shimizu, K

    2001-07-01

    The mixed cultivation using cheaper carbon source-wasted food material contained glucose and lactate at the same time was conducted in 5L fermentor, within which glucose was converted to lactate by L. delbrueckii in anaerobic condition and the lactate was converted to PHB by R. eutropha in aerobic condition. Considering dissolved oxygen concentration may affect the level of intracellular ATP and NADPH of the metabolic pathways for R. eutropha in lactate under autotrophy or heterotrophy, rhythmical oscillated control for DO based on chaos control method was consequently presented. This method was employed to satisfy two strains for opposite oxygen preferences, moreover, excite the intracellular metabolic energy simultaneously. The values examined through spectrophotofluorimetry represented that both ATP and NADPH exhibited fluctuations in accordance with the DO rhythm. By means of this control design, the concentration of PHB can be doubled than the usual under stable DO control.

  4. Periodontal disease and its influence on the metabolic control of diabetes

    OpenAIRE

    Marcia Maehler; Tatiana Miranda Deliberador; Geisla Mary Silva Soares; Ricardo Luiz Grein; Gastão Valle Nicolau

    2011-01-01

    Introduction: Currently, it is accepted that the periodontal disease is more prevalent and severe in people with diabetes mellitus compared to non-diabetic people. On the other hand, patients with severe periodontitis may present difficulty in performing glycemic control. Objective: The objective of the present study is to determine, through a literature review, the influence of the periodontal disease on the metabolic control of diabetic patients. Literature review: PubMed database was sear...

  5. Metabolic control of cell division in α-proteobacteria by a NAD-dependent glutamate dehydrogenase.

    Science.gov (United States)

    Beaufay, François; De Bolle, Xavier; Hallez, Régis

    2016-01-01

    Prior to initiate energy-consuming processes, such as DNA replication or cell division, cells need to evaluate their metabolic status. We have recently identified and characterized a new connection between metabolism and cell division in the α-proteobacterium Caulobacter crescentus. We showed that an NAD-dependent glutamate dehydrogenase (GdhZ) coordinates growth with cell division according to its enzymatic activity. Here we report the conserved role of GdhZ in controlling cell division in another α-proteobacterium, the facultative intracellular pathogen Brucella abortus. We also discuss the importance of amino acids as a main carbon source for α-proteobacteria.

  6. Subclinical peripheral neuropathy in type 1 diabetic adolescents and its relationship with metabolic control

    Directory of Open Access Journals (Sweden)

    Sajić Silvija

    2005-01-01

    Full Text Available Professional management of paediatric diabetology, according to consensus guidelines, involves the screening of micro-vascular complications at puberty. The subclinical form of peripheral neural dysfunction in diabetic teenagers is reported with a frequency of 50-88%, by different authors. The purpose of this study was to evaluate the frequency of subclinical distal neuropathy (DSMN in type 1 diabetic pediatric patients during the second decade of life, and its relationship with metabolic control. The Endocrinology Department and the Neurology-Physiology Laboratory of the Pediatric Clinic in Belgrade carried out a longitudinal follow-up study (lasting 18 months, beginning in November 2000 on a selection of patients with poor metabolic control. During routine clinical treatment, patients were evaluated using the electrophysiological diagnostic method on peripheral neural dysfunction, a subclinical form of neuropathy. Metabolic control was manifested through HbA1c levels, measured every 3 months, using ion-exchange chromatography. Finally, here is the data collected from the clinical follow-up investigation of 60 children, aged 13-19 (median 1S.S±2.2, with duration of diabetes from 2-16 years (median b.3±3.b, and on the following therapies: 43 CT-conventional and 17 IIT-intensive, and insulin dose/day, median 1.02 (0.6-2.1 U/kg. Detected DSMN parameters at the beginning and at the end of the study were also noted. DSMN frequency was positive, at 64% for HbA1c of 9.44; DSMN dysfunction was reversed in 5% of the patients, for HbA1c of 10.17; the worst result was the progression of DSMN at 6.7% for HbA1c of 10.52; 6.7% had negative DSMN, with improved metabolic control, for HbA1c of 8.4; 15% of the examinations were unfinished (+/*. ANOVA statistical analysis showed a significant statistical relationship between metabolic control (HbA1c levels and DSMN neuropathy (sig. 0.043, p<0.05. There was no significant relationship between the reversion of

  7. Multifunctional Cascaded Metamaterials: Integrated Transmitarrays

    CERN Document Server

    Elsakka, Amr A; Faniayeu, Ihar A; Tcvetkova, Svetlana N; Tretyakov, Sergei A

    2016-01-01

    Control of electromagnetic waves using engineered materials is very important in a wide range of applications, therefore there is always a continuous need for new and more efficient solutions. Known natural and artificial materials and surfaces provide a particular functionality in the frequency range they operate but cast a "shadow" and produce reflections at other frequencies. Here, we introduce a concept of multifunctional engineered materials that possess different predetermined functionalities at different frequencies. Such response can be accomplished by cascading metasurfaces (thin composite layers) that are designed to perform a single operation at the desired frequency and are transparent elsewhere. Previously, out-of-band transparent metasurfaces for control over reflection and absorption were proposed. In this paper, to complete the full set of functionalities for wave control, we synthesize transmitarrays that tailor transmission in a desired way, being "invisible" beyond the operational band. The...

  8. Cascaded neural networks for sequenced propagation estimation, multiuser detection, and adaptive radio resource control of third-generation wireless networks for multimedia services

    Science.gov (United States)

    Hortos, William S.

    1999-03-01

    interference, control carrier-sense multiple-access (CSMA) protocols, and refine call handoff procedures. In the final stage, the Kohonen SOFM, operating in a hybrid continuous and discrete space, adaptively allocates the resources of antenna-based cell sectorization, activity monitoring, variable-rate coding, power control, handoff and caller admission to meet user demands for various multimedia services at minimum QoS levels. The performance of the NN cascade is evaluated through simulation of a candidate 3G wireless network using W-CDMA parameters in a small-cell environment. The simulated network consists of a representative number of cells. Mobile users with typical movement patterns are assumed. QoS requirements for different classes of multimedia services are considered. The proposed method is shown to provide relatively low probability of new call blocking and handoff dropping, while maintaining efficient use of the network's radio resources.

  9. Influence of blood flow on the coagulation cascade

    DEFF Research Database (Denmark)

    The influence of diffusion and convetive flows on the blood coagulation cascade is investigated for a controlled perfusion experiment. We present a cartoon model and reaction schemes for parts of the coagulation cascade with sunsequent set up of a mathematical model in two space dimensions plus one...

  10. Predicting epistasis: an experimental test of metabolic control theory with bacterial transcription and translation.

    Science.gov (United States)

    MacLean, R C

    2010-03-01

    Epistatic interactions between mutations are thought to play a crucial role in a number of evolutionary processes, including adaptation and sex. Evidence for epistasis is abundant, but tests of general theoretical models that can predict epistasis are lacking. In this study, I test the ability of metabolic control theory to predict epistasis using a novel experimental approach that combines phenotypic and genetic perturbations of enzymes involved in gene expression and protein synthesis in the bacterium Pseudomonas aeruginosa. These experiments provide experimental support for two key predictions of metabolic control theory: (i) epistasis between genes involved in the same pathway is antagonistic; (ii) epistasis becomes increasingly antagonistic as mutational severity increases. Metabolic control theory is a general theory that applies to any set of genes that are involved in the same linear processing chain, not just metabolic pathways, and I argue that this theory is likely to have important implications for predicting epistasis between functionally coupled genes, such as those involved in antibiotic resistance. Finally, this study highlights the fact that phenotypic manipulations of gene activity provide a powerful method for studying epistasis that complements existing genetic methods.

  11. Lifestyle Intervention on Metabolic Syndrome and its Impact on Quality of Life: A Randomized Controlled Trial

    Science.gov (United States)

    Saboya, Patrícia Pozas; Bodanese, Luiz Carlos; Zimmermann, Paulo Roberto; Gustavo, Andreia da Silva; Macagnan, Fabricio Edler; Feoli, Ana Pandolfo; Oliveira, Margareth da Silva

    2017-01-01

    Background Lifestyle intervention programs can reduce the prevalence of metabolic syndrome (MetS) and, therefore, reduce the risk for cardiac disease, one of the main public health problems nowadays. Objective The aim of this study was to compare the effects of three types of approach for lifestyle change programs in the reduction of metabolic parameters, and to identify its impact on the quality of life (QOL) of individuals with MetS. Methods A randomized controlled trial included 72 individuals with MetS aged 30-59 years. Individuals were randomized into three groups of multidisciplinary intervention [Standard Intervention (SI) - control group; Group Intervention (GI); and Individual Intervention (II)] during 12 weeks. The primary outcome was change in the metabolic parameters, and secondarily, the improvement in QOL measures at three moments: baseline, 3 and 9 months. Results Group and individual interventions resulted in a significant reduction in body mass index, waist circumference, systolic blood pressure at 3 months and the improvement of QOL, although it was significantly associated with the physical functioning domain. However, these changes did not remain 6 months after the end of intervention. Depression and anxiety were significantly associated with worse QOL, although they showed no effect on the response to intervention. Conclusion Multidisciplinary intervention, especially in a group, might be an effective and economically feasible strategy in the control of metabolic parameters of MetS and improvement of QOL compared to SI, even in a dose-effect relationship. PMID:27982160

  12. AMPKα1-LDH pathway regulates muscle stem cell self-renewal by controlling metabolic homeostasis.

    Science.gov (United States)

    Theret, Marine; Gsaier, Linda; Schaffer, Bethany; Juban, Gaëtan; Ben Larbi, Sabrina; Weiss-Gayet, Michèle; Bultot, Laurent; Collodet, Caterina; Foretz, Marc; Desplanches, Dominique; Sanz, Pascual; Zang, Zizhao; Yang, Lin; Vial, Guillaume; Viollet, Benoit; Sakamoto, Kei; Brunet, Anne; Chazaud, Bénédicte; Mounier, Rémi

    2017-07-03

    Control of stem cell fate to either enter terminal differentiation versus returning to quiescence (self-renewal) is crucial for tissue repair. Here, we showed that AMP-activated protein kinase (AMPK), the master metabolic regulator of the cell, controls muscle stem cell (MuSC) self-renewal. AMPKα1(-/-) MuSCs displayed a high self-renewal rate, which impairs muscle regeneration. AMPKα1(-/-) MuSCs showed a Warburg-like switch of their metabolism to higher glycolysis. We identified lactate dehydrogenase (LDH) as a new functional target of AMPKα1. LDH, which is a non-limiting enzyme of glycolysis in differentiated cells, was tightly regulated in stem cells. In functional experiments, LDH overexpression phenocopied AMPKα1(-/-) phenotype, that is shifted MuSC metabolism toward glycolysis triggering their return to quiescence, while inhibition of LDH activity rescued AMPKα1(-/-) MuSC self-renewal. Finally, providing specific nutrients (galactose/glucose) to MuSCs directly controlled their fate through the AMPKα1/LDH pathway, emphasizing the importance of metabolism in stem cell fate. © 2017 The Authors.

  13. A new cascadic multigrid

    Institute of Scientific and Technical Information of China (English)

    SHI; Zhongci

    2001-01-01

    [1]Bornemann, F., Deuflhard, P., The cascadic multigrid method for elliptic problems, Numer. Math., 996, 75: 35.[2]Bornemann, F., Deuflhard, P., The cascadic multigrid method, The Eighth International Conference on Domain Decomposition Methods for Partial Differential Equations (eds. Glowinski, R., Periaux, J., Shi, Z. et al.), New York: John Wiley and Sons, 997.[3]Bornemann, F., Krause, R., Classical and cascadic multigrid-methodogical comparison, Proceedings of the 9th International Conference on Domain Decomposition (eds. Bjorstad, P., Espedal, M., Keyes, D.), New York: John Wiley and Sons, 998.[4]Shaidurov, V., Some estimates of the rate of convergence for the cascadic conjugate gradient method, Comp. Math. Applic., 996, 3: 6.[5]Shi, Z., Xu, X., Cascadic multigrid method for the second order elliptic problem, East-West J. Numer. Math., 998, 6: 309.[6]Shi, Z., Xu, X., Cascadic multigrid for elliptic problems, East-West J. Numer. Math., 999, 7: 99.[7]Shi, Z., Xu, X., Cascadic multigrid method for the plate bending problem, East-West J. Numer. Math., 998, 6: 37.[8]Braess, D., Dahmen, W., A cascade multigrid algorithm for the Stokes equations, Number. Math., 999, 82: 79.[9]Shi, Z., Xu, X., Cascadic multigrid for parabolic problems, J. Comput. Math., 2000, 8: 450.[10]Ciarlet, P.,The Finite Element Method for Elliptic Problems, Amsterdam: North-Holland, 978.[11]Zienkiewicz, O. C., The Finite Element Method, 3rd. ed., London: McGraw-Hill, 977.[12]Powell, M. J. D., Sabin, M. A., Piecewise quadratic approximations on triangles, ACM Trans. Mat. Software, 977, 3: 36.[13]Xu, J., The auxiliary space method and optimal multigrid precondition techniques for unstructured grids, Computing, 996, 56: 25.[14]Bank, R., Dupont, T., An optimal order process for solving finite element equations, Math. Comput., 980, 36: 35.[15]Brenner, S., Convergence of nonconforming multigrid methods without full elliptic regularity, Math

  14. Understanding the control of acyl flux through the lipid metabolic network of plant oil biosynthesis.

    Science.gov (United States)

    Bates, Philip D

    2016-09-01

    Plant oil biosynthesis involves a complex metabolic network with multiple subcellular compartments, parallel pathways, cycles, and pathways that have a dual function to produce essential membrane lipids and triacylglycerol. Modern molecular biology techniques provide tools to alter plant oil compositions through bioengineering, however with few exceptions the final composition of triacylglycerol cannot be predicted. One reason for limited success in oilseed bioengineering is the inadequate understanding of how to control the flux of fatty acids through various fatty acid modification, and triacylglycerol assembly pathways of the lipid metabolic network. This review focuses on the mechanisms of acyl flux through the lipid metabolic network, and highlights where uncertainty resides in our understanding of seed oil biosynthesis. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.

  15. [Biological activities of exogenous polysaccharides via controlling endogenous proteoglycan metabolism in vascular endothelial cells].

    Science.gov (United States)

    Sato, Tomoko; Yamamoto, Chika; Fujiwara, Yasuyuki; Kaji, Toshiyuki

    2008-05-01

    Proteoglycan contains glycosmainoglycans, which are endogenous sulfated polysaccharides, in the molecule. The metabolism of proteoglycans regulates cell behavior and cellular events. It is possible that exogenous polysaccharide-related molecules exhibit their biological activities by two mechanisms. One is the interaction with cells and the other is the interaction with growth factors/cytokines that regulate proteoglycans. In this review, we describe sodium spirulan, a sulfated polysaccharide obtained from a hot-water extract of the blue-green alga Spirulina platensis, as an exogenous polysaccharide that stimulates the release of proteoglycans from vascular endothelial cells. Factors that regulate endothelial proteoglycan metabolism are also being described as possible target molecules of exogenous polysaccharides. Further research is required to obtain exogenous polysaccharide-related molecules that exhibit useful biological activities through controlling endothelial proteoglycan metabolism for protection against vascular lesions such as atheroslcerosis.

  16. Successful control of dyslipidemia in patients with metabolic syndrome: focus on lifestyle changes.

    Science.gov (United States)

    Stone, Neil J

    2006-01-01

    Approaches to controlling dyslipidemia in patients with metabolic syndrome must take into consideration a patient's individual characteristics and underlying lipid disorder. Some patients will require pharmacologic therapy, whereas others can be controlled with lifestyle changes alone. The National Cholesterol Education Program (NCEP) Adult Treatment Panel III (ATP III) guidelines recommend that patients with at least 3 of the following clinical variables be designated as having metabolic syndrome: abdominal obesity as reflected in increased waist circumference; a low high-density lipoprotein cholesterol (HDL-C) level; an elevated triglyceride level; elevated blood pressure or treatment with antihypertensive medications; and/or elevated fasting plasma glucose or treatment with antidiabetic medications. Unless patients with metabolic syndrome change their lifestyle, existing cardiovascular and metabolic risk factors will worsen or new risk factors will develop. This helps explain why these patients are at increased risk for developing type 2 diabetes mellitus (DM) and coronary heart disease (CHD). The lifestyle changes recommended by NCEP ATP III for controlling dyslipidemia (i.e., elevated levels of triglycerides and decreased levels of HDL-C) in patients with metabolic syndrome or type 2 DM include (1) reduced intake of saturated fats and dietary cholesterol, (2) intake of dietary options to enhance lowering of low-density lipoprotein cholesterol, (3) weight control, and (4) increased physical activity. If lifestyle changes are not successful for individuals at high risk of developing CHD, or for those who currently have CHD, a CHD risk equivalent, or persistent atherogenic dyslipidemia, then pharmacotherapy may be necessary as defined by NCEP ATP III guidelines.

  17. Impact of hypothalamic reactive oxygen species in the control of energy metabolism and food intake

    Directory of Open Access Journals (Sweden)

    Anne eDrougard

    2015-02-01

    Full Text Available Hypothalamus is a key area involved in the control of metabolism and food intake via the integrations of numerous signals (hormones, neurotransmitters, metabolites from various origins. These factors modify hypothalamic neurons activity and generate adequate molecular and behavioral responses to control energy balance. In this complex integrative system, a new concept has been developed in recent years, that includes reactive oxygen species (ROS as a critical player in energy balance. ROS are known to act in many signaling pathways in different peripheral organs, but also in hypothalamus where they regulate food intake and metabolism by acting on different types of neurons, including proopiomelanocortin (POMC and agouti-related protein (AgRP/neuropeptide Y (NPY neurons. Hypothalamic ROS release is under the influence of different factors such as pancreatic and gut hormones, adipokines (leptin, apelin,..., neurotransmitters and nutrients (glucose, lipids,.... The sources of ROS production are multiple including NADPH oxidase, but also the mitochondria which is considered as the main ROS producer in the brain. ROS are considered as signaling molecules, but conversely impairment of this neuronal signaling ROS pathway contributes to alterations of autonomic nervous system and neuroendocrine function, leading to metabolic diseases such as obesity and type 2 diabetes.In this review we focus our attention on factors that are able to modulate hypothalamic ROS release in order to control food intake and energy metabolism, and whose deregulations could participate to the development of pathological conditions. This novel insight reveals an original mechanism in the hypothalamus that controls energy balance and identify hypothalamic ROS signaling as a potential therapeutic strategy to treat metabolic disorders.

  18. Monitoring and robust adaptive control of fed-batch cultures of microorganisms exhibiting overflow metabolism [abstract

    Directory of Open Access Journals (Sweden)

    Vande Wouwer, A.

    2010-01-01

    Full Text Available Overflow metabolism characterizes cells strains that are likely to produce inhibiting by-products resulting from an excess of substrate feeding and a saturated respiratory capacity. The critical substrate level separating the two different metabolic pathways is generally not well defined. Monitoring of this kind of cultures, going from model identification to state estimation, is first discussed. Then, a review of control techniques which all aim at maximizing the cell productivity of fed-batch fermentations is presented. Two main adaptive control strategies, one using an estimation of the critical substrate level as set-point and another regulating the by-product concentration, are proposed. Finally, experimental investigations of an adaptive RST control scheme using the observer polynomial for the regulation of the ethanol concentration in Saccharomyces cerevisiae fed-batch cultures ranging from laboratory to industrial scales, are also presented.

  19. [Quality of carbohydrates in the diet and their effect on metabolic control of type 2 diabetes].

    Science.gov (United States)

    Pincheira, Daniela; Morgado, Romina; Alviña, Marcela; Vega, Claudia

    2014-12-01

    The objective of this study was to determine the relationship between the parameters of metabolic control and quality of carbohydrates (CHO) of the diet in individuals with type 2 diabetes, controlled with diet and/or Metformin. In 108 men and women aged between 18 and 60 years, glycosylated hemoglobin A (HbA1c) between 6% and 10%, without sulfonylureas or insulin theraphy; were examined through two separate surveys of 24-hour recall. The CHO intake, GI, GL of diet was analyzed. Values of HbA1c were collected from medical records. Data was tabulated in SPSS version 17 software. The Pearson correlation test was used to analyze the degree of association between variables, considering significant at p diet and HbA1c levels in the individuals. In conclusion the study showed that the quality of CHO, mainly GI, are strongly associated with metabolic control of DM 2.

  20. Metabolic Control of Dendritic Cell Activation and Function: Recent Advances and Clinical Implications

    Directory of Open Access Journals (Sweden)

    Bart eEverts

    2014-05-01

    Full Text Available Dendritic cells (DCs are key regulators of both immunity and tolerance by controlling activation and polarization of effector T helper cell and regulatory T cell responses. Therefore, there is a major focus on developing approaches to manipulate DC function for immunotherapy. It is well known that changes in cellular activation are coupled to profound changes in cellular metabolism. Over the past decade there is a growing appreciation that these metabolic changes also underlie the capacity of immune cells to perform particular functions. This has led to the concept that the manipulation of cellular metabolism can be used to shape innate and adaptive immune responses. While most of our understanding in this area has been gained from studies with T cells and macrophages, evidence is emerging that the activation and function of DCs are also dictated by the type of metabolism these cells commit to. We here discuss these new insights and explore whether targeting of metabolic pathways in DCs could hold promise as a novel approach to manipulate the functional properties of DCs for clinical purposes.

  1. The peroxisome proliferator-activated receptors under epigenetic control in placental metabolism and fetal development.

    Science.gov (United States)

    Lendvai, Ágnes; Deutsch, Manuel J; Plösch, Torsten; Ensenauer, Regina

    2016-05-15

    The placental metabolism can adapt to the environment throughout pregnancy to both the demands of the fetus and the signals from the mother. Such adaption processes include epigenetic mechanisms, which alter gene expression and may influence the offspring's health. These mechanisms are linked to the diversity of prenatal environmental exposures, including maternal under- or overnutrition or gestational diabetes. The peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that contribute to the developmental plasticity of the placenta by regulating lipid and glucose metabolism pathways, including lipogenesis, steroidogenesis, glucose transporters, and placental signaling pathways, thus representing a link between energy metabolism and reproduction. Among the PPAR isoforms, PPARγ appears to be the main modulator of mammalian placentation. Certain fatty acids and lipid-derived moieties are the natural activating PPAR ligands. By controlling the amounts of maternal nutrients that go across to the fetus, the PPARs play an important regulatory role in placenta metabolism, thereby adapting to the maternal nutritional status. As demonstrated in animal studies, maternal nutrition during gestation can exert long-term influences on the PPAR methylation pattern in offspring organs. This review underlines the current state of knowledge on the relationship between environmental factors and the epigenetic regulation of the PPARs in placenta metabolism and offspring development. Copyright © 2016 the American Physiological Society.

  2. 基于神经网络逆系统方法的链式STATCOM线性化解耦控制%Linearization decoupling control of cascaded STATCOM based on the method of artificial neural networks inverse system

    Institute of Scientific and Technical Information of China (English)

    刘庆锋; 粟时平; 刘桂英; 吕超

    2016-01-01

    Aiming at the control problem of cascaded STATCOM to compensate the load reactive current and stabilize the grid voltage, this paper establishes dynamic mathematics model of cascaded STATCOM, and obtains the relation-ship of the two variablesδ、M and current, then proposes a control method based on artificial neural networks inverse system.The linearization decoupling control of active and reactive current of cascaded STATCOM is realized through the verification of reversibility, construction of artificial neural networks as well as the design of control system for the system of cascaded STATCOM.Finally, the simulation results show that the control strategy acquires good dynamic effect and static effect when switching inductive load into capacitive load or in turn, which makes the device possess better performance to resist parameters change and load disturbance, thereby, it illustrates the effectiveness and the feasibility of the control strategy.%针对链式STATCOM补偿负载无功电流以及稳定电网电压的控制问题,建立了链式STATCOM动态数学模型,得出了双变量δ、M(移相角与调制比)和电流的关系式,提出了一种基于神经网络逆系统控制方法,通过对该链式STATCOM系统可逆的验证、神经网络的构建以及控制系统的设计,实现了链式STATCOM输出的有功-无功电流的线性化解耦控制。仿真结果表明,在感性负载与容性负载进行切换以时,该控制策略取得了良好的动态效果以及稳态效果,使得装置具有较好的抗参数变化、抗负载扰动性能,从而验证了该控制策略的有效性及可行性。

  3. 电厂过热汽温串级系统的约束预测控制%Cascade Constrained Model Predictive Control for Power Plant Superheated Steam Temperature System

    Institute of Scientific and Technical Information of China (English)

    冯建苗; 李少远

    2011-01-01

    Power plant superheated steam temperature system is characterized by large inertia and large lag.Usually spray system is applied to form a cascade control system and cascade PID scheme is usually employed to control superheated steam temperature.The spray valve is subject to physical constraints so that actuator saturation happens because of the set point computed by the outer loop controller.The method of cascade model predictive control was applied.Constrained model predictive control(CMPC) was used to handle constraints and obtain optimal solution with system satisfying the corresponding constraints.In addition,simulation of superheated steam system was realized.%针对实际电厂过热汽温系统中减温水阀门受到物理约束限制,外环控制器计算的设定值造成执行机构饱和从而影响系统性能的问题,提出了串级预测控制算法,并采用约束预测控制算法进行求解,在系统约束范围内求得系统性能的优化解,对电厂过热汽温控制系统进行了仿真论证.仿真结果表明,过热汽温系统控制量能被有效控制在约束范围内,并且系统保持了良好的运行结果.

  4. Adolescents with type 1 diabetes: parental perceptions of child health and family functioning and their relationship to adolescent metabolic control

    National Research Council Canada - National Science Library

    Moore, Susan M; Hackworth, Naomi J; Hamilton, Victoria E; Northam, Elisabeth P; Cameron, Fergus J

    2013-01-01

    Adolescents with Type 1 diabetes (T1D) show less effective metabolic control than other age groups, partly because of biological changes beyond their control and partly because in this period of developmental transition, psychosocial...

  5. The role of AVDR in linear cascade testing

    Institute of Scientific and Technical Information of China (English)

    Bo Song; Wing F.Ng

    2007-01-01

    Linear cascade testing plays an important role in the research and development of turbomachinery and is widelv used over the world.The ideal cascade model of a turbomachinery blade row is two-dimensional.In actual linear cascade tesring,the flow through the test section converges due to the development of the boundary layer and secondary flow along the sidewall surfaces of the test section.Axial velocity density ratio(AVDR)is adopted to account for the deviation of the tested cascade flow from the ideal 2D model.Among numerous published cascade works,the influence of AVDR on cascade performance is seen to be complicated with many affecting factors,such as those related to cascade/blade geometry and flow conditions.Also,controlling AVDR is limited by the facility capability.Furthermore'real blade-to-blade flow in turborrlachines is usually associated with AVDR greater than unity due to limited span of blades between the hub and shroud such that cascade testing without reducing AVDR could be favored sometimes.All these facets add complexity and diversification to the matter.The current paper reviews previous studies and results on AVDR.ConsoIidated understanding on the role of AVDR and recommendations on how to deal with it in linear cascade testing are provided.

  6. Cascade enzymatic reactions for efficient carbon sequestration.

    Science.gov (United States)

    Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

    2015-04-01

    Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA.

  7. RECONFIGURING POWER SYSTEMS TO MINIMIZE CASCADING FAILURES: MODELS AND ALGORITHMS

    Energy Technology Data Exchange (ETDEWEB)

    Bienstock, Daniel

    2014-04-11

    the main goal of this project was to develop new scientific tools, based on optimization techniques, with the purpose of controlling and modeling cascading failures of electrical power transmission systems. We have developed a high-quality tool for simulating cascading failures. The problem of how to control a cascade was addressed, with the aim of stopping the cascade with a minimum of load lost. Yet another aspect of cascade is the investigation of which events would trigger a cascade, or more appropriately the computation of the most harmful initiating event given some constraint on the severity of the event. One common feature of the cascade models described (indeed, of several of the cascade models found in the literature) is that we study thermally-induced line tripping. We have produced a study that accounts for exogenous randomness (e.g. wind and ambient temperature) that could affect the thermal behavior of a line, with a focus on controlling the power flow of the line while maintaining safe probability of line overload. This was done by means of a rigorous analysis of a stochastic version of the heat equation. we incorporated a model of randomness in the behavior of wind power output; again modeling an OPF-like problem that uses chance-constraints to maintain low probability of line overloads; this work has been continued so as to account for generator dynamics as well.

  8. Metabolic control analysis of L-lactate synthesis pathway in Rhizopus oryzae As 3.2686.

    Science.gov (United States)

    Ke, Wei; Chang, Shu; Chen, Xiaoju; Luo, Shuizhong; Jiang, Shaotong; Yang, Peizhou; Wu, Xuefeng; Zheng, Zhi

    2015-11-01

    The relationship between the metabolic flux and the activities of the pyruvate branching enzymes of Rhizopus oryzae As 3.2686 during L-lactate fermentation was investigated using the perturbation method of aeration. The control coefficients for five enzymes, pyruvate dehydrogenase (PDH), pyruvate carboxylase (PC), pyruvate decarboxylase (PDC), lactate dehydrogenase (LDH), and alcohol dehydrogenase (ADH), were calculated. Our results indicated significant correlations between PDH and PC, PDC and LDH, PDC and ADH, LDH and ADH, and PDC and PC. It also appeared that PDH, PC, and LDH strongly controlled the L-lactate flux; PDH and ADH strongly controlled the ethanol flux; while PDH and PC strongly controlled the acetyl coenzyme A flux and the oxaloacetate flux. Further, the flux control coefficient curves indicated that the control of the system gradually transferred from PDC to PC during the steady state. Therefore, PC was the key rate-limiting enzyme that controls the flux distribution.

  9. Information cascade on networks

    Science.gov (United States)

    Hisakado, Masato; Mori, Shintaro

    2016-05-01

    In this paper, we discuss a voting model by considering three different kinds of networks: a random graph, the Barabási-Albert (BA) model, and a fitness model. A voting model represents the way in which public perceptions are conveyed to voters. Our voting model is constructed by using two types of voters-herders and independents-and two candidates. Independents conduct voting based on their fundamental values; on the other hand, herders base their voting on the number of previous votes. Hence, herders vote for the majority candidates and obtain information relating to previous votes from their networks. We discuss the difference between the phases on which the networks depend. Two kinds of phase transitions, an information cascade transition and a super-normal transition, were identified. The first of these is a transition between a state in which most voters make the correct choices and a state in which most of them are wrong. The second is a transition of convergence speed. The information cascade transition prevails when herder effects are stronger than the super-normal transition. In the BA and fitness models, the critical point of the information cascade transition is the same as that of the random network model. However, the critical point of the super-normal transition disappears when these two models are used. In conclusion, the influence of networks is shown to only affect the convergence speed and not the information cascade transition. We are therefore able to conclude that the influence of hubs on voters' perceptions is limited.

  10. Identification of regulatory network hubs that control lipid metabolism in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Gargouri, Mahmoud; Park, Jeong-Jin; Holguin, F Omar; Kim, Min-Jeong; Wang, Hongxia; Deshpande, Rahul R; Shachar-Hill, Yair; Hicks, Leslie M; Gang, David R

    2015-08-01

    Microalgae-based biofuels are promising sources of alternative energy, but improvements throughout the production process are required to establish them as economically feasible. One of the most influential improvements would be a significant increase in lipid yields, which could be achieved by altering the regulation of lipid biosynthesis and accumulation. Chlamydomonas reinhardtii accumulates oil (triacylglycerols, TAG) in response to nitrogen (N) deprivation. Although a few important regulatory genes have been identified that are involved in controlling this process, a global understanding of the larger regulatory network has not been developed. In order to uncover this network in this species, a combined omics (transcriptomic, proteomic and metabolomic) analysis was applied to cells grown in a time course experiment after a shift from N-replete to N-depleted conditions. Changes in transcript and protein levels of 414 predicted transcription factors (TFs) and transcriptional regulators (TRs) were monitored relative to other genes. The TF and TR genes were thus classified by two separate measures: up-regulated versus down-regulated and early response versus late response relative to two phases of polar lipid synthesis (before and after TAG biosynthesis initiation). Lipidomic and primary metabolite profiling generated compound accumulation levels that were integrated with the transcript dataset and TF profiling to produce a transcriptional regulatory network. Evaluation of this proposed regulatory network led to the identification of several regulatory hubs that control many aspects of cellular metabolism, from N assimilation and metabolism, to central metabolism, photosynthesis and lipid metabolism.

  11. The Role of Monoaminergic Neurotransmission for Metabolic Control in the Fruit Fly Drosophila Melanogaster

    Directory of Open Access Journals (Sweden)

    Yong Li

    2017-08-01

    Full Text Available Hormones control various metabolic traits comprising fat deposition or starvation resistance. Here we show that two invertebrate neurohormones, octopamine (OA and tyramine (TA as well as their associated receptors, had a major impact on these metabolic traits. Animals devoid of the monoamine OA develop a severe obesity phenotype. Using flies defective in the expression of receptors for OA and TA, we aimed to decipher the contributions of single receptors for these metabolic phenotypes. Whereas those animals impaired in octß1r, octß2r and tar1 share the obesity phenotype of OA-deficient (tβh-deficient animals, the octß1r, octß2r deficient flies showed reduced insulin release, which is opposed to the situation found in tβh-deficient animals. On the other hand, OAMB deficient flies were leaner than controls, implying that the regulation of this phenotype is more complex than anticipated. Other phenotypes seen in tβh-deficient animals, such as the reduced ability to perform complex movements tasks can mainly be attributed to the octß2r. Tissue-specific RNAi experiments revealed a very complex interorgan communication leading to the different metabolic phenotypes observed in OA or OA and TA-deficient flies.

  12. Adaptive stabilization for cascade nonlinear systems

    Institute of Scientific and Technical Information of China (English)

    陈岚萍; 王洪元; 吴波

    2004-01-01

    An adaptive controller of full state feedback for certain cascade nonlinear systems achieving input-to-state stability with respect to unknown bounded disturbance is designed using backstepping and control Lyapunov function (CLF)techniques. We show that unknown bounded disturbance can be estimated by update laws, which requires less information on unknown disturbance, as a part of stabilizing control. The design method achieves the desired property: global robust stability. Our contribution is illustrated with the example of a disturbed pendulum.

  13. The effect of 12 weeks Anethum graveolens (dill on metabolic markers in patients with metabolic syndrome; a randomized double blind controlled trial

    Directory of Open Access Journals (Sweden)

    Mansouri Masoume

    2012-10-01

    Full Text Available Abstract Background The clustering of metabolic abnormalities defined as metabolic syndrome is now both a public health and a clinical problem .While interest in herbal medicine has greatly increased, lack of human evidence to support efficacies shown in animals does exist. This clinical trial study designed to investigate whether herbal medicine, Anethum graveolens (dill extract, could improve metabolic components in patients with metabolic syndrome. Methods A double-blind, randomized, placebo-controlled trial using a parallel design was conducted. 24 subjects who had metabolic syndrome diagnostic criteria (update of ATP III were randomly assigned to either dill extract (n = 12 or placebo (n = 12 for 3 months. Results Across lipid component of metabolic syndrome, no significant differences in triglyceride (TG concentration and high density lipoprotein cholesterol were seen between the two groups. However TG improved significantly from baseline (257.0 vs. 201.5p = 0.01 with dill treatment but such a significant effect was not observed in placebo group. Moreover, no significant differences in waist circumference, blood pressure and fasting blood sugar were seen between two groups after 3 months follow up period. Conclusion In this small clinical trial in patients with metabolic syndrome, 12 weeks of dill extract treatment had a beneficial effect in terms of reducing TG from baseline. However dill treatment was not associated with a significant improvement in metabolic syndrome related markers compared to control group. Larger studies might be required to prove the efficacy and safety of long-term administration of dill to resolve metabolic syndrome components.

  14. The effect of 12 weeks Anethum graveolens (dill on metabolic markers in patients with metabolic syndrome; a randomized double blind controlled trial

    Directory of Open Access Journals (Sweden)

    Bagher Larijani

    2012-10-01

    Full Text Available The clustering of metabolic abnormalities defined as metabolic syndrome is now both a public health and a clinical problem .While interest in herbal medicine has greatly increased, lack of human evidence to support efficacies shown in animals does exist. This clinical trial study designed to investigate whether herbal medicine, Anethum graveolens (dill extract, could improve metabolic components in patients with metabolic syndrome.MethodsA double-blind, randomized, placebo-controlled trial using a parallel design was conducted. 24 subjects who had metabolic syndrome diagnostic criteria (update of ATP III were randomly assigned to either dill extract (n = 12 or placebo (n = 12 for 3 months.ResultsAcross lipid component of metabolic syndrome, no significant differences in triglyceride (TG concentration and high density lipoprotein cholesterol were seen between the two groups. However TG improved significantly from baseline (257.0 vs. 201.5p = 0.01 with dill treatment but such a significant effect was not observed in placebo group. Moreover, no significant differences in waist circumference, blood pressure and fasting blood sugar were seen between two groups after 3 months follow up period.ConclusionIn this small clinical trial in patients with metabolic syndrome, 12 weeks of dill extract treatment had a beneficial effect in terms of reducing TG from baseline. However dill treatment was not associated with a significant improvement in metabolic syndrome related markers compared to control group. Larger studies might be required to prove the efficacy and safety of long-term administration of dill to resolve metabolic syndrome components.

  15. Effect of an intensive metabolic control lifestyle intervention in type-2 diabetes patients.

    Science.gov (United States)

    Gamiochipi, Mireya; Cruz, Miguel; Kumate, Jesús; Wacher, Niels H

    2016-07-01

    To evaluate the effectiveness of an intensive lifestyle intervention on metabolic control in patients with type 2 diabetes. 199 patients recently diagnosed with type 2 diabetes, with lack of metabolic control and overweight/obesity, were randomly assigned to intensive lifestyle intervention or collaborative educational program alone, with 6 months of follow-up. Intervention included 150min of physical activity a week to reduce body weight by 7%. Both groups received 16 sessions on behavior modification over the course of the 6 months. Measurements were taken at baseline, 3 and 6 months. Results were analyzed and compared. Significant weight loss was achieved by both groups, with greater loss in the intervention group. Those with lower baseline A1c appeared to benefit more from the educational program than intensive intervention over time. Both interventions produced positive if modest changes in metabolic control. These results suggest that, for weight loss and control of A1c, an intensive intervention may be more effective. The current study demonstrates the value of a systematic application of behavior modification and self-care techniques in the treatment of type 2 diabetes. It demonstrates the importance of intensive, all-inclusive treatment, and of attention to individual concerns. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Metabolic transistor strategy for controlling electron transfer chain activity in Escherichia coli.

    Science.gov (United States)

    Wu, Hui; Tuli, Leepika; Bennett, George N; San, Ka-Yiu

    2015-03-01

    A novel strategy to finely control a large metabolic flux by using a "metabolic transistor" approach was established. In this approach a small change in the level or availability of an essential component for the process is controlled by adding a competitive reaction that affects a precursor or an intermediate in its biosynthetic pathway. The change of the basal level of the essential component, considered as a base current in a transistor, has a large effect on the flux through the major pathway. In this way, the fine-tuning of a large flux can be accomplished. The "metabolic transistor" strategy was applied to control electron transfer chain function by manipulation of the quinone synthesis pathway in Escherichia coli. The achievement of a theoretical yield of lactate production under aerobic conditions via this strategy upon manipulation of the biosynthetic pathway of the key participant, ubiquinone-8 (Q8), in an E. coli strain provides an in vivo, genetically tunable means to control the activity of the electron transfer chain and manipulate the production of reduced products while limiting consumption of oxygen to a defined amount.

  17. Role of parenting style in achieving metabolic control in adolescents with type 1 diabetes.

    Science.gov (United States)

    Shorer, Maayan; David, Ravit; Schoenberg-Taz, Michal; Levavi-Lavi, Ifat; Phillip, Moshe; Meyerovitch, Joseph

    2011-08-01

    To examine the role of parenting style in achieving metabolic control and treatment adherence in adolescents with type 1 diabetes. Parents of 100 adolescents with type 1 diabetes completed assessments of their parenting style and sense of helplessness. Parents and patients rated patient adherence to the treatment regimen. Glycemic control was evaluated by HbA(1c) values. An authoritative paternal parenting style predicted better glycemic control and adherence in the child; a permissive maternal parenting style predicted poor adherence. A higher sense of helplessness in both parents predicted worse glycemic control and lesser adherence to treatment. Parental sense of helplessness was a significant predictor of diabetes control after correcting for other confounders (patient age, sex, and treatment method). An authoritative nonhelpless parenting style is associated with better diabetes control in adolescents. Paternal involvement is important in adolescent diabetes management. These results have implications for psychological interventions.

  18. Arginase 1 is an innate lymphoid cell-intrinsic metabolic checkpoint controlling type 2 inflammation

    Science.gov (United States)

    Monticelli, Laurel A; Buck, Michael D; Flamar, Anne-Laure; Saenz, Steven A; Wojno, Elia D Tait; Yudanin, Naomi A; Osborne, Lisa C; Hepworth, Matthew R; Tran, Sara V; Rodewald, Hans-Reimer; Shah, Hardik; Cross, Justin R; Diamond, Joshua M; Cantu, Edward; Christie, Jason D; Pearce, Erika L; Artis, David

    2016-01-01

    Group 2 innate lymphoid cells (ILC2s) regulate tissue inflammation and repair following activation by cell-extrinsic factors including host-derived cytokines. However, the cell-intrinsic metabolic pathways that control ILC2 function are undefined. Here we demonstrate that expression of the enzyme Arginase 1 (Arg1) is a conserved trait of murine and human ILC2s during acute or chronic lung inflammation. Deletion of murine ILC-intrinsic Arg1 abrogated type 2 lung inflammation by restraining ILC2 proliferation and dampening cytokine production. Mechanistically, inhibition of Arg1 enzymatic activity disrupted multiple components of ILC2 metabolic programming by altering arginine catabolism, impairing polyamine biosynthesis and reducing aerobic glycolysis. These data identify Arg1 as a key regulator of ILC2 bioenergetics, controlling proliferative capacity and pro-inflammatory functions that promote type 2 inflammation. PMID:27043409

  19. Gastrointestinal function and metabolic control after construction of an orthotopic ileal neobladder in bladder cancer

    DEFF Research Database (Denmark)

    Thorstenson, Andreas; Jacobsson, Hans; Onelöv, Erik

    2007-01-01

    OBJECTIVE: To investigate the effects of ileum resection in orthotopic neobladder construction on gastrointestinal function and metabolic control. MATERIAL AND METHODS: We included 28 patients who underwent radical cystectomy and construction of an orthotopic neobladder or continent ileal reservoir...... were unchanged. CONCLUSIONS: Using the distal ileum for orthotopic neobladder construction causes bowel disorders in a quarter of cystectomy patients. Diarrhoea and faecal urgency are probably caused by decreased reabsorption of bile and are not due to changes in gastrointestinal hormones. A sizeable...

  20. Metabolic flux and nodes control analysis of brewer's yeasts under different fermentation temperature during beer brewing.

    Science.gov (United States)

    Yu, Zhimin; Zhao, Haifeng; Zhao, Mouming; Lei, Hongjie; Li, Huiping

    2012-12-01

    The aim of this work was to further investigate the glycolysis performance of lager and ale brewer's yeasts under different fermentation temperature using a combined analysis of metabolic flux, glycolytic enzyme activities, and flux control. The results indicated that the fluxes through glycolytic pathway decreased with the change of the fermentation temperature from 15 °C to 10 °C, which resulted in the prolonged fermentation times. The maximum activities (V (max)) of hexokinase (HK), phosphofructokinase (PFK), and pyruvate kinase (PK) at key nodes of glycolytic pathway decreased with decreasing fermentation temperature, which was estimated to have different control extent (22-84 %) on the glycolytic fluxes in exponential or flocculent phase. Moreover, the decrease of V (max) of PFK or PK displayed the crucial role in down-regulation of flux in flocculent phase. In addition, the metabolic state of ale strain was more sensitive to the variation of temperature than that of lager strain. The results of the metabolic flux and nodes control analysis in brewer's yeasts under different fermentation temperature may provide an alternative approach to regulate glycolytic flux by changing V (max) and improve the production efficiency and beer quality.

  1. Hepatic mTORC1 controls locomotor activity, body temperature, and lipid metabolism through FGF21

    Science.gov (United States)

    Cornu, Marion; Oppliger, Wolfgang; Albert, Verena; Robitaille, Aaron M.; Trapani, Francesca; Quagliata, Luca; Fuhrer, Tobias; Sauer, Uwe; Terracciano, Luigi; Hall, Michael N.

    2014-01-01

    The liver is a key metabolic organ that controls whole-body physiology in response to nutrient availability. Mammalian target of rapamycin (mTOR) is a nutrient-activated kinase and central controller of growth and metabolism that is negatively regulated by the tumor suppressor tuberous sclerosis complex 1 (TSC1). To investigate the role of hepatic mTOR complex 1 (mTORC1) in whole-body physiology, we generated liver-specific Tsc1 (L-Tsc1 KO) knockout mice. L-Tsc1 KO mice displayed reduced locomotor activity, body temperature, and hepatic triglyceride content in a rapamycin-sensitive manner. Ectopic activation of mTORC1 also caused depletion of hepatic and plasma glutamine, leading to peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α)–dependent fibroblast growth factor 21 (FGF21) expression in the liver. Injection of glutamine or knockdown of PGC-1α or FGF21 in the liver suppressed the behavioral and metabolic defects due to mTORC1 activation. Thus, mTORC1 in the liver controls whole-body physiology through PGC-1α and FGF21. Finally, mTORC1 signaling correlated with FGF21 expression in human liver tumors, suggesting that treatment of glutamine-addicted cancers with mTOR inhibitors might have beneficial effects at both the tumor and whole-body level. PMID:25082895

  2. Synthetic biology and regulatory networks: where metabolic systems biology meets control engineering.

    Science.gov (United States)

    He, Fei; Murabito, Ettore; Westerhoff, Hans V

    2016-04-01

    Metabolic pathways can be engineered to maximize the synthesis of various products of interest. With the advent of computational systems biology, this endeavour is usually carried out through in silico theoretical studies with the aim to guide and complement further in vitro and in vivo experimental efforts. Clearly, what counts is the result in vivo, not only in terms of maximal productivity but also robustness against environmental perturbations. Engineering an organism towards an increased production flux, however, often compromises that robustness. In this contribution, we review and investigate how various analytical approaches used in metabolic engineering and synthetic biology are related to concepts developed by systems and control engineering. While trade-offs between production optimality and cellular robustness have already been studied diagnostically and statically, the dynamics also matter. Integration of the dynamic design aspects of control engineering with the more diagnostic aspects of metabolic, hierarchical control and regulation analysis is leading to the new, conceptual and operational framework required for the design of robust and productive dynamic pathways.

  3. Risk of metabolic syndrome among children living in metropolitan Kuala Lumpur: a case control study.

    Science.gov (United States)

    Wee, Bee S; Poh, Bee K; Bulgiba, Awang; Ismail, Mohd N; Ruzita, Abdul T; Hills, Andrew P

    2011-05-18

    With the increasing prevalence of childhood obesity, the metabolic syndrome has been studied among children in many countries but not in Malaysia. Hence, this study aimed to compare metabolic risk factors between overweight/obese and normal weight children and to determine the influence of gender and ethnicity on the metabolic syndrome among school children aged 9-12 years in Kuala Lumpur and its metropolitan suburbs. A case control study was conducted among 402 children, comprising 193 normal-weight and 209 overweight/obese. Weight, height, waist circumference (WC) and body composition were measured, and WHO (2007) growth reference was used to categorise children into the two weight groups. Blood pressure (BP) was taken, and blood was drawn after an overnight fast to determine fasting blood glucose (FBG) and full lipid profile, including triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC). International Diabetes Federation (2007) criteria for children were used to identify metabolic syndrome. Participants comprised 60.9% (n = 245) Malay, 30.9% (n = 124) Chinese and 8.2% (n = 33) Indian. Overweight/obese children showed significantly poorer biochemical profile, higher body fat percentage and anthropometric characteristics compared to the normal-weight group. Among the metabolic risk factors, WC ≥90th percentile was found to have the highest odds (OR = 189.0; 95%CI 70.8, 504.8), followed by HDL-C≤1.03 mmol/L (OR = 5.0; 95%CI 2.4, 11.1) and high BP (OR = 4.2; 95%CI 1.3, 18.7). Metabolic syndrome was found in 5.3% of the overweight/obese children but none of the normal-weight children (p family history of communicable diseases with the metabolic syndrome. However, for ethnicity, Indians were found to have higher odds (OR = 5.5; 95%CI 1.5, 20.5) compared to Malays, with Chinese children (OR = 0.3; 95%CI 0.0, 2.7) having the lowest odds. We conclude that being overweight or obese

  4. 基于模糊神经网络PID的液位串级控制的研究%The Study of Level Cascade Control System Based on FNN PID

    Institute of Scientific and Technical Information of China (English)

    王雪梅

    2013-01-01

    利用PID算法对液位串级系统进行控制虽然是一种有效的控制方法,但由于它的精确数学模型难以确定,使得参数整定困难、控制效果不理想.该文将PID算法、模糊控制算法以及神经网络算法相结合,形成了一种智能控制算法——模糊神经网络PID算法.将该算法运用到液位串级控制系统中,实现了PID参数的自整定,并且提高了控制质量.实验结果表明,模糊神经网络PID算法与PID算法的控制效果相比,在鲁棒性和响应时间等方面有了较大的提高,具有一定的应用前景.%Use PID algorithm level cascade control system is an effective although control method, since it's difficult to determine precise mathematical model, making parameter tuning difficulties, control effect is not ideal. This paper addresses this issue, PID algorithm, fuzzy control algorithms and neural network algorithms to form an intelligent control algorithm-FNN PID algorithm. The algorithm applied to the liquid level cascade control system, the PID parameters to achieve the self-tuning and improved quality control. The experimental results show that FNN PID algorithm and PID algorithm compared to the control results in robustness and response time and so on has been enhanced, with a certain application.

  5. Insulin signaling meets mitochondria in metabolism.

    Science.gov (United States)

    Cheng, Zhiyong; Tseng, Yolanda; White, Morris F

    2010-10-01

    Insulin controls nutrient and metabolic homeostasis via the IRS-PI3K-AKT signaling cascade that targets FOXO1 and mTOR. Mitochondria, as the prime metabolic platform, malfunction during insulin resistance in metabolic diseases. However, the molecular link between insulin resistance and mitochondrial dysfunction remains undefined. Here we review recent studies on insulin action and the mechanistic association with mitochondrial metabolism. These studies suggest that insulin signaling underpins mitochondrial electron transport chain integrity and activity by suppressing FOXO1/HMOX1 and maintaining the NAD(+)/NADH ratio, the mediator of the SIRT1/PGC1α pathway for mitochondrial biogenesis and function. Mitochondria generate moderately reactive oxygen species (ROS) and enhance insulin sensitivity upon redox regulation of protein tyrosine phosphatase and insulin receptor. However, chronic exposure to high ROS levels could alter mitochondrial function and thereby cause insulin resistance.

  6. Cholesterol Metabolism and Weight Reduction in Subjects with Mild Obstructive Sleep Apnoea: A Randomised, Controlled Study

    Directory of Open Access Journals (Sweden)

    Maarit Hallikainen

    2013-01-01

    Full Text Available To evaluate whether parameters of obstructive sleep apnoea (OSA associate with cholesterol metabolism before and after weight reduction, 42 middle-aged overweight subjects with mild OSA were randomised to intensive lifestyle intervention (N=23 or to control group (N=18 with routine lifestyle counselling only. Cholesterol metabolism was evaluated with serum noncholesterol sterol ratios to cholesterol, surrogate markers of cholesterol absorption (cholestanol and plant sterols and synthesis (cholestenol, desmosterol, and lathosterol at baseline and after 1-year intervention. At baseline, arterial oxygen saturation (SaO2 was associated with serum campesterol (P<0.05 and inversely with desmosterol ratios (P<0.001 independently of gender, BMI, and homeostasis model assessment index of insulin resistance (HOMA-IR. Apnoea-hypopnoea index (AHI was not associated with cholesterol metabolism. Weight reduction significantly increased SaO2and serum cholestanol and decreased AHI and serum cholestenol ratios. In the groups combined, the changes in AHI were inversely associated with changes of cholestanol and positively with cholestenol ratios independent of gender and the changes of BMI and HOMA-IR (P<0.05. In conclusion, mild OSA seemed to be associated with cholesterol metabolism independent of BMI and HOMA-IR. Weight reduction increased the markers of cholesterol absorption and decreased those of cholesterol synthesis in the overweight subjects with mild OSA.

  7. Geniposide regulates glucose-stimulated insulin secretion possibly through controlling glucose metabolism in INS-1 cells.

    Directory of Open Access Journals (Sweden)

    Jianhui Liu

    Full Text Available Glucose-stimulated insulin secretion (GSIS is essential to the control of metabolic fuel homeostasis. The impairment of GSIS is a key element of β-cell failure and one of causes of type 2 diabetes mellitus (T2DM. Although the KATP channel-dependent mechanism of GSIS has been broadly accepted for several decades, it does not fully describe the effects of glucose on insulin secretion. Emerging evidence has suggested that other mechanisms are involved. The present study demonstrated that geniposide enhanced GSIS in response to the stimulation of low or moderately high concentrations of glucose, and promoted glucose uptake and intracellular ATP levels in INS-1 cells. However, in the presence of a high concentration of glucose, geniposide exerted a contrary role on both GSIS and glucose uptake and metabolism. Furthermore, geniposide improved the impairment of GSIS in INS-1 cells challenged with a high concentration of glucose. Further experiments showed that geniposide modulated pyruvate carboxylase expression and the production of intermediates of glucose metabolism. The data collectively suggest that geniposide has potential to prevent or improve the impairment of insulin secretion in β-cells challenged with high concentrations of glucose, likely through pyruvate carboxylase mediated glucose metabolism in β-cells.

  8. Effects of hyperlipidaemia on glucocorticoid metabolism: results of a randomized controlled trial in healthy young women.

    Science.gov (United States)

    Mai, K; Reinecke, F; Andres, J; Bobbert, T; Kraatz, J; Wudy, S A; Hartmann, M F; Maser-Gluth, C; Pfeiffer, A F H; Spranger, J

    2011-05-01

    It is well established that the hypothalamic-pituitary-adrenal (HPA) axis is altered in obese individuals. Hyperlipidaemia with elevated levels of free fatty acids (FFAs) is also frequently seen in obesity and in the metabolic syndrome. We hypothesized, therefore, that hyperlipidaemia may alter the activity of the HPA axis. The effects of hyperlipidaemia, including increased circulating FFAs, on ACTH secretion and cortisol metabolism were analysed in 13 healthy young women during the early follicular phase of two subsequent cycles. We administered a 20% lipid/heparin (LHI) or a saline/heparin infusion (SHI) using a crossover design in random order for 330 min. A detailed characterization of glucocorticoid metabolism was performed by measurement of plasma ACTH, cortisol and urinary excretion rates of adrenal glucocorticoids and the glucocorticoid metabolites. We observed that LHI-induced hyperlipidaemia elevated serum cortisol levels compared to SHI. No changes in plasma ACTH levels, daily urinary excretion rates of adrenal glucocorticoids, glucocorticoid precursors/metabolites and the calculated activities of the 5α-reductase, 3β-hydroxysteroid dehydrogenase (HSD), 11-, 17-, 21-hydroxylase and 11β-HSD 1 or 2 were found. Our randomized controlled trial suggests that the adrenal sensitivity to ACTH may be enhanced by LHI-induced hyperlipidaemia in normal-weight healthy young women. This effect might contribute to the disturbances of the HPA axis described in women with abdominal obesity and impaired lipid metabolism. © 2011 Blackwell Publishing Ltd.

  9. Visceral adiposity influences glucose and glycogen metabolism in control and hyperlipidic-fed animals

    Directory of Open Access Journals (Sweden)

    Danielle Kaiser de Souza

    2013-04-01

    Full Text Available Introduction: Evidences suggest that fat intake, visceral obesity and intracellular lipids are related to insulin impairment. Objective: The objective of the present paper was correlate visceral obesity and metabolic alterations in control (CTR and hyperlipidic cafeteria diet (CFT fed animals. Methods: After 6 months of diet treatment, liver and muscle of the male rats were utilized to determined glucose uptake and glycogen metabolism after administration of 0.4I U/kg insulin in vivo, and correlate the visceral adiposity to these two parameters. Results: Ample range of physiologic answers to body composition in metabolic profile of the both diets was found. No differences were found in glycemia and triacylglycerol after insulin action in both groups, however CFT group accumulated higher adiposity, mostly visceral fat, and showed lower glycogen content in the liver. We also found an inverse correlation between visceral adiposity and glucose uptake and a decrease of the glycogen synthase active form in the liver. CTR animals demonstrated an inverse correlation between glucose uptake and visceral adiposity in the muscle. Discussion and conclusion: It was observed a variability of metabolic alterations in animals which can be related to degree of accumulation of abdominal adiposity and ingestion of diet fats. Further studies will be required to clarify the reasons for the observed liver alterations in CFT and muscle alterations in CTR animals.

  10. Metabolic responses of upper-body accelerometer-controlled video games in adults.

    Science.gov (United States)

    Stroud, Leah C; Amonette, William E; Dupler, Terry L

    2010-10-01

    Historically, video games required little physical exertion, but new systems utilize handheld accelerometers that require upper-body movement. It is not fully understood if the metabolic workload while playing these games is sufficient to replace routine physical activity. The purpose of this study was to quantify metabolic workloads and estimate caloric expenditure while playing upper-body accelerometer-controlled and classic seated video games. Nineteen adults completed a peak oxygen consumption treadmill test followed by an experimental session where exercising metabolism and ventilation were measured while playing 3 video games: control (CON), low activity (LOW) and high activity (HI). Resting metabolic measures (REST) were also acquired. Caloric expenditure was estimated using the Weir equation. Mean oxygen consumption normalized to body weight for HI condition was greater than LOW, CON, and REST. Mean oxygen consumption normalized to body weight for LOW condition was also greater than CON and REST. Mean exercise intensities of oxygen consumption reserve for HI, LOW, and CON were 25.8% ± 5.1%, 6.4% ± 4.8%, and 0.8% ± 2.4%, respectively. Estimated caloric expenditure during the HI was significantly related to aerobic fitness, but not during other conditions. An active video game significantly elevated oxygen consumption and heart rate, but the increase was dependent on the type of game. The mean oxygen consumption reserve during the HI video game was below recommended international standards for moderate and vigorous activity. Although upper-body accelerometer-controlled video games provided a greater exercising stimulus than classic seated video games, these data suggest they should not replace routine moderate or vigorous exercise.

  11. T-cell Metabolism as a Target to Control Autoreactive T Cells in β-Cell Autoimmunity.

    Science.gov (United States)

    Bordignon, Carlotta; Canu, Adriana; Dyczko, Aleksandra; Leone, Serena; Monti, Paolo

    2017-05-01

    An increasing body of evidence indicates that bio-energetic metabolism of activated T cells is a potential target to control the autoimmune response in type 1 diabetes (T1D). T-cell activation and proliferation is linked to the cell capacity to provide sufficient energy and biosynthesis molecules to support T-cell growth and division. This makes T cells susceptible to metabolic inhibition for the control of the T-cell response. There is a wide therapeutic arsenal of metabolic inhibitors, including novel classes of drugs that have become recently available. With the current knowledge and availability of metabolic inhibitors, we are now in the position to design a metabolic inhibition strategy to determine whether targeting of autoreactive T cells is an effective strategy to control the process of β-cell destruction in T1D.

  12. Network reconstruction from infection cascades

    CERN Document Server

    Braunstein, Alfredo

    2016-01-01

    Reconstructing propagation networks from observations is a fundamental inverse problem, and it's crucial to understand and control dynamics in complex systems. Here we show that it is possible to reconstruct the whole structure of an interaction network and to simultaneously infer the complete time course of activation spreading, relying just on single snapshots of a small number of activity cascades. The method, that we called Inverse Dynamics Network Reconstruction (IDNR), is shown to work successfully on several synthetic and real networks, inferring the networks and the sources of infection based on sparse observations, including single snapshots. IDNR is built on a Belief Propagation approximation, that has an impressive performance in a wide variety of topological structures. The method can be applied in absence of complete time-series data by providing a detailed modeling of the posterior distribution of trajectories conditioned to the observations. Furthermore, we show by experiments that the informat...

  13. Tolerance of edge cascades with coupled map lattices methods

    Institute of Scientific and Technical Information of China (English)

    Cui Di; Gao Zi-You; Zheng Jian-Feng

    2009-01-01

    This paper studies the cascading failure on random networks and scale-free networks by introducing the tolerance parameter of edge based on the coupled map lattices methods. The whole work focuses on investigating some indices including the number of failed edges, dynamic edge tolerance capacity and the perturbation of edge. In general, it assumes that the perturbation is attributed to the normal distribution in adopted simulations. By investigating the effectiveness of edge tolerance in scale-free and random networks, it finds that the larger tolerance parameter 位 can more efficiently delay the cascading failure process for scale-free networks than random networks. These results indicate that the cascading failure process can be effectively controlled by increasing the tolerance parameter A. Moreover, the simulations also show that, larger variance of perturbation can easily trigger the cascading failures than the smaller one. This study may be useful for evaluating efficiency of whole traffic systems, and for alleviating cascading failure in such systems.

  14. Period-doubling cascades galore

    OpenAIRE

    Sander, Evelyn; Yorke, James A.

    2009-01-01

    The appearance of numerous period-doubling cascades is among the most prominent features of {\\bf parametrized maps}, that is, smooth one-parameter families of maps $F:R \\times {\\mathfrak M} \\to {\\mathfrak M}$, where ${\\mathfrak M}$ is a smooth locally compact manifold without boundary, typically $R^N$. Each cascade has infinitely many period-doubling bifurcations, and it is typical to observe -- such as in all the examples we investigate here -- that whenever there are any cascades, there are...

  15. Design of the improved cascade ADRC and its application in photoelectric tracking system

    Science.gov (United States)

    Zuo, Dan; Tang, Tao; Huang, Yongmei; Cai, Huaxiang

    2015-10-01

    According to the larger error when reversing in photoelectric tracking control system, the improved cascade Active Disturbance Rejection Controller (ADRC) is put forward to improve the system position tracking performance and tracking precision. First of all, this essay analyses the controlled object model and system control strategy; Then, it gives design method of the improved cascade ADRC; Finally, in order to analyses the improved cascade's better control performance, in the condition of the same input signal ,the improved cascade ADRC, conventional ADRC-ADRC and traditional PI-PI controller are used in photoelectric tracking control system to do comparative experiment. The experiment results show that the improved cascade ADRC's performance is better than other two algorithms, the tracking error and the steady state mean square error are significantly reduced, tracking accuracy is significantly improved. The improved cascade ADRC is an appealing solution in dealing with industrial control system problems where uncertainties and interference abound.

  16. The Neurometabolic Cascade of Concussion

    National Research Council Canada - National Science Library

    Giza, Christopher C; Hovda, David A

    2001-01-01

    Data Synthesis: The primary elements of the pathophysiologic cascade following concussive brain injury include abrupt neuronal depolarization, release of excitatory neurotransmitters, ionic shifts, changes...

  17. Inferring Network Structure from Cascades

    CERN Document Server

    Ghonge, Sushrut

    2016-01-01

    Many physical, biological and social phenomena can be described by cascades taking place on a network. Often, the activity can be empirically observed, but not the underlying network of interactions. In this paper we solve the dynamics of general cascade processes. We then offer three topological inversion methods to infer the structure of any directed network given a set of cascade arrival times. Our forward and inverse formulas hold for a very general class of models where the activation probability of a node is a generic function of its degree and the number of its active neighbors. We report high success rates for synthetic and real networks, for 5 different cascade models.

  18. A Soft Sensor for Bioprocess Control Based on Sequential Filtering of Metabolic Heat Signals

    Directory of Open Access Journals (Sweden)

    Dan Paulsson

    2014-09-01

    Full Text Available Soft sensors are the combination of robust on-line sensor signals with mathematical models for deriving additional process information. Here, we apply this principle to a microbial recombinant protein production process in a bioreactor by exploiting bio-calorimetric methodology. Temperature sensor signals from the cooling system of the bioreactor were used for estimating the metabolic heat of the microbial culture and from that the specific growth rate and active biomass concentration were derived. By applying sequential digital signal filtering, the soft sensor was made more robust for industrial practice with cultures generating low metabolic heat in environments with high noise level. The estimated specific growth rate signal obtained from the three stage sequential filter allowed controlled feeding of substrate during the fed-batch phase of the production process. The biomass and growth rate estimates from the soft sensor were also compared with an alternative sensor probe and a capacitance on-line sensor, for the same variables. The comparison showed similar or better sensitivity and lower variability for the metabolic heat soft sensor suggesting that using permanent temperature sensors of a bioreactor is a realistic and inexpensive alternative for monitoring and control. However, both alternatives are easy to implement in a soft sensor, alone or in parallel.

  19. [Evaluation of metabolic control in a summer camp for diabetic children (Villarcayo 1991)].

    Science.gov (United States)

    Fuertes Alija, J J; Ruiz Pérez, E; Galindo Jimeno, M; Ergueta Martín, P; González Sarmiento, E

    1993-04-01

    The relevance of the diabetological education in the treatment of diabetis mellitus must be a prioritary goal in order to reach a proper metabolic control and to avoid as much as possible both acute metabolic complications and long-term vascular and neurological complications, achieving thus a total integration of the diabetic patient in the society. We have monitored during 15 days a group of diabetic children with IDDM in a summer camp, assessing in all of them several clinical and biochemical parameters. The results have been statistically analyzed using the Student's test. After the stay in the summer camp, we observed a significant reduction in the total dose of insulin (p < 0.001) and in the number of hypoglycemias (p < 0.001) and an increase in the average levels of capillary glycemia at the end of the study period when compared with the beginning, with p < 0.001 (breakfast preprandial), p < 0.05 (lunch preprandial) and p < 0.01 (dinner and night preprandial). We did not observe any significant differences in the other parameters studied. In inclusion, the stay in the summer camp of this group had a positive effect, achieving a better metabolic control with lower doses of insulin.

  20. Should antioxidant vitamin supplementation be applied in patients with metabolic syndrome? A case-control study

    Directory of Open Access Journals (Sweden)

    Małgorzata Godala

    2016-03-01

    Full Text Available Introduction : All cells in the human body are exposed to reactive oxygen species (ROS, which disturb the metabolic reactions in the organism. The antioxidant system in the human body consists of enzymatic and non-enzymatic mechanisms, among which vitamins A, C, and E play a major role. The aim of the study was to evaluate the supply of vitamins A, C, and E from daily food rations (DFR in postmenopausal women with metabolic syndrome (MS in relation to current nutrition standards. Material and methods: The study involved 184 women with MS, aged 45-68 years (mean 57.38 ±8.17 years. The control group comprised 90 women, aged 41-65 years (mean 57.48 ±5.79 years without MS. The food intake was assessed using 24-hour dietary recalls. Results: The evaluation of intake of vitamins measured with daily food rations (DFR demonstrated that the optimal level of 90-110% according to standards was achieved only in 3.62% of women with metabolic syndrome for vitamin A, in 8.88% for vitamin C, and in 11.41% for vitamin E, which was significantly less often found than in the control group (p < 0.001. Conclusions : Women with MS are characterised by diversified intake of vitamins A, C and E, and a subgroup of this patients present low level of antioxidant vitamins intake. Supplementation with antioxidant vitamins should be prescribed individually to postmenopausal women with MS.

  1. Structured, intensive education maximising engagement, motivation and long-term change for children and young people with diabetes: a cluster randomised controlled trial with integral process and economic evaluation - the CASCADE study.

    Science.gov (United States)

    Christie, Deborah; Thompson, Rebecca; Sawtell, Mary; Allen, Elizabeth; Cairns, John; Smith, Felicity; Jamieson, Elizabeth; Hargreaves, Katrina; Ingold, Anne; Brooks, Lucy; Wiggins, Meg; Oliver, Sandy; Jones, Rebecca; Elbourne, Diana; Santos, Andreia; Wong, Ian C K; O'Neill, Simon; Strange, Vicki; Hindmarsh, Peter; Annan, Francesca; Viner, Russell

    2014-03-01

    organising groups, and work and school commitments. Young people with higher HbA1c levels were less likely to attend. Parents and young people who attended groups described improved family relationships, improved knowledge and understanding, greater confidence and increased motivation to manage diabetes. Twenty-four months after the intervention, nearly half of the young people reported that the groups had made them want to try harder and that they had carried on trying. A high-quality, complex, pragmatic trial of structured education can be delivered alongside standard care in NHS diabetes clinics. Health-care providers benefited from behaviour change skill training and can deliver pragmatic aspects of a National Institute for Health and Care Excellence (NICE)-compliant structured education programme after relatively brief training. The process evaluation provides insight into aspects of the model, and highlights strengths and aspects that may have contributed to the failure to influence primary and secondary outcomes. Current NHS practice dominates CASCADE (Child and Adolescent Structured Competencies Approach to Diabetes Education) in that it achieves the same number of QALYs at a lower cost. The mean cost of providing the intervention was £5098 per site or £683 per child. Members of paediatric diabetes services trained to deliver the CASCADE structured education package using behaviour change techniques did not improve glycaemic control in patients compared with control subjects 1 and 2 years after the intervention. The training workshops for practitioners were well evaluated; however, more intensive training was needed. The intervention cost £683 per patient but was not cost-effective because it did not improve metabolic control. A high-quality, complex, pragmatic trial of structured education can be successfully conducted alongside standard care in NHS diabetes clinics. Pragmatic components of a NICE-compliant structured education programme can be successfully

  2. Risk of metabolic syndrome among children living in metropolitan Kuala Lumpur: A case control study

    Directory of Open Access Journals (Sweden)

    Ismail Mohd N

    2011-05-01

    Full Text Available Abstract Background With the increasing prevalence of childhood obesity, the metabolic syndrome has been studied among children in many countries but not in Malaysia. Hence, this study aimed to compare metabolic risk factors between overweight/obese and normal weight children and to determine the influence of gender and ethnicity on the metabolic syndrome among school children aged 9-12 years in Kuala Lumpur and its metropolitan suburbs. Methods A case control study was conducted among 402 children, comprising 193 normal-weight and 209 overweight/obese. Weight, height, waist circumference (WC and body composition were measured, and WHO (2007 growth reference was used to categorise children into the two weight groups. Blood pressure (BP was taken, and blood was drawn after an overnight fast to determine fasting blood glucose (FBG and full lipid profile, including triglycerides (TG, high-density lipoprotein cholesterol (HDL-C, low-density lipoprotein cholesterol (LDL-C and total cholesterol (TC. International Diabetes Federation (2007 criteria for children were used to identify metabolic syndrome. Results Participants comprised 60.9% (n = 245 Malay, 30.9% (n = 124 Chinese and 8.2% (n = 33 Indian. Overweight/obese children showed significantly poorer biochemical profile, higher body fat percentage and anthropometric characteristics compared to the normal-weight group. Among the metabolic risk factors, WC ≥90th percentile was found to have the highest odds (OR = 189.0; 95%CI 70.8, 504.8, followed by HDL-C≤1.03 mmol/L (OR = 5.0; 95%CI 2.4, 11.1 and high BP (OR = 4.2; 95%CI 1.3, 18.7. Metabolic syndrome was found in 5.3% of the overweight/obese children but none of the normal-weight children (p Conclusions We conclude that being overweight or obese poses a greater risk of developing the metabolic syndrome among children. Indian ethnicity is at higher risk compared to their counterparts of the same age. Hence, primary intervention strategies are

  3. Energy Cascades in MHD

    Science.gov (United States)

    Alexakis, A.

    2009-04-01

    Most astrophysical and planetary systems e.g., solar convection and stellar winds, are in a turbulent state and coupled to magnetic fields. Understanding and quantifying the statistical properties of magneto-hydro-dynamic (MHD) turbulence is crucial to explain the involved physical processes. Although the phenomenological theory of hydro-dynamic (HD) turbulence has been verified up to small corrections, a similar statement cannot be made for MHD turbulence. Since the phenomenological description of Hydrodynamic turbulence by Kolmogorov in 1941 there have been many attempts to derive a similar description for turbulence in conducting fluids (i.e Magneto-Hydrodynamic turbulence). However such a description is going to be based inevitably on strong assumptions (typically borrowed from hydrodynamics) that do not however necessarily apply to the MHD case. In this talk I will discuss some of the properties and differences of the energy and helicity cascades in turbulent MHD and HD flows. The investigation is going to be based on the analysis of direct numerical simulations. The cascades in MHD turbulence appear to be a more non-local process (in scale space) than in Hydrodynamics. Some implications of these results to turbulent modeling will be discussed

  4. Information cascade on networks

    CERN Document Server

    Hisakado, Masato

    2015-01-01

    In this paper, we discuss a voting model by considering three different kinds of networks: a random graph, the Barab\\'{a}si-Albert(BA) model, and a fitness model. A voting model represents the way in which public perceptions are conveyed to voters. Our voting model is constructed by using two types of voters--herders and independents--and two candidates. Independents conduct voting based on their fundamental values; on the other hand, herders base their voting on the number of previous votes. Hence, herders vote for the majority candidates and obtain information relating to previous votes from their networks. We discussed the difference between the phases on which the networks depend. Two kinds of phase transitions, an information cascade transition and a super-normal transition, were identified. The first of these is a transition between a state in which most voters make the correct choices and a state in which most of them are wrong. The second is a transition of convergence speed. The information cascade t...

  5. Spatial control of the energy metabolism of yeast cells through electrolytic generation of oxygen.

    Science.gov (United States)

    Warnke, Christian; Mair, Thomas; Witte, Hartmut; Reiher, Antje; Hauser, Marcus J B; Krost, Alois

    2009-11-03

    The metabolic dynamics of yeast cells is controlled by electric pulses delivered through a spatially extended yeast cell/Au electrode interface. Concomitant with voltage pulses, oxygen is generated electrolytically at the electrode surface and delivered to the cells. The generation of oxygen was investigated in dependence of the applied voltage, width of the voltage pulses and temperature of the electrolytic solution. The local oxygen pulses at the electrodes lead to a transient activation of the aerobic energy metabolism of the yeast cells causing a perturbation in their energy balance. The effect of these local perturbations on the temporal dynamics of glycolysis in yeast cells is quantified in dependence of the energy state of cells.

  6. Selenium, zinc and copper in plasma of patients with type 1 diabetes mellitus in different metabolic control states

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, C.; Alegria, A.; Barbera, R.; Farre, R.; Lagarda, M.J. [Valencia Univ. (Spain). Lab. of Nutrition and Food Chemistry

    1998-07-01

    The Studies of selenium (Se), zinc (Zn) and copper (Cu) levels in diabetic patients have led to contradictory findings as to the possible relationship between the degree of diabetic control and the changes in mineral contents. In the present study the plasma Cu, Se and Zn contents of diabetic patients and healthy people were measured and the relationship between these contents and diabetic metabolic control, as determined by glycosylated hemoglobin (HbA{sub 1c}), was studied. The mean plasma Se content in diabetic patients was significantly lower than in controls (p<0.01) and a negative correlation between the plasma contents of Se and HbA{sub 1c} was found. No statistically significant differences in plasma Zn contents, either between patients with type 1 diabetes mellitus and controls, or between patients with type 1 diabetes mellitus but different degrees of metabolic control, were found. A statistically significant sex difference in plasma Cu contents was observed in the control population. In females, statistically significant differences were found in plasma Cu contents between the control subjects and the diabetic patients with medium or poor metabolic control, as well as between diabetic patients with good and poor metabolic control. In males, the only statistically significant differences were between the control subjects and diabetic patients with poor metabolic control. The correlation between plasma contents of Cu and HbA{sub 1c} is not significant. (orig.)

  7. Drosophila adiponectin receptor in insulin producing cells regulates glucose and lipid metabolism by controlling insulin secretion.

    Directory of Open Access Journals (Sweden)

    Su-Jin Kwak

    Full Text Available Adipokines secreted from adipose tissue are key regulators of metabolism in animals. Adiponectin, one of the adipokines, modulates pancreatic beta cell function to maintain energy homeostasis. Recently, significant conservation between Drosophila melanogaster and mammalian metabolism has been discovered. Drosophila insulin like peptides (Dilps regulate energy metabolism similarly to mammalian insulin. However, in Drosophila, the regulatory mechanism of insulin producing cells (IPCs by adipokine signaling is largely unknown. Here, we describe the discovery of the Drosophila adiponectin receptor and its function in IPCs. Drosophila adiponectin receptor (dAdipoR has high homology with the human adiponectin receptor 1. The dAdipoR antibody staining revealed that dAdipoR was expressed in IPCs of larval and adult brains. IPC- specific dAdipoR inhibition (Dilp2>dAdipoR-Ri showed the increased sugar level in the hemolymph and the elevated triglyceride level in whole body. Dilps mRNA levels in the Dilp2>dAdipoR-Ri flies were similar with those of controls. However, in the Dilp2>dAdipoR-Ri flies, Dilp2 protein was accumulated in IPCs, the level of circulating Dilp2 was decreased, and insulin signaling was reduced in the fat body. In ex vivo fly brain culture with the human adiponectin, Dilp2 was secreted from IPCs. These results indicate that adiponectin receptor in insulin producing cells regulates insulin secretion and controls glucose and lipid metabolism in Drosophila melanogaster. This study demonstrates a new adipokine signaling in Drosophila and provides insights for the mammalian adiponectin receptor function in pancreatic beta cells, which could be useful for therapeutic application.

  8. Drosophila adiponectin receptor in insulin producing cells regulates glucose and lipid metabolism by controlling insulin secretion.

    Science.gov (United States)

    Kwak, Su-Jin; Hong, Seung-Hyun; Bajracharya, Rijan; Yang, Se-Yeol; Lee, Kyu-Sun; Yu, Kweon

    2013-01-01

    Adipokines secreted from adipose tissue are key regulators of metabolism in animals. Adiponectin, one of the adipokines, modulates pancreatic beta cell function to maintain energy homeostasis. Recently, significant conservation between Drosophila melanogaster and mammalian metabolism has been discovered. Drosophila insulin like peptides (Dilps) regulate energy metabolism similarly to mammalian insulin. However, in Drosophila, the regulatory mechanism of insulin producing cells (IPCs) by adipokine signaling is largely unknown. Here, we describe the discovery of the Drosophila adiponectin receptor and its function in IPCs. Drosophila adiponectin receptor (dAdipoR) has high homology with the human adiponectin receptor 1. The dAdipoR antibody staining revealed that dAdipoR was expressed in IPCs of larval and adult brains. IPC- specific dAdipoR inhibition (Dilp2>dAdipoR-Ri) showed the increased sugar level in the hemolymph and the elevated triglyceride level in whole body. Dilps mRNA levels in the Dilp2>dAdipoR-Ri flies were similar with those of controls. However, in the Dilp2>dAdipoR-Ri flies, Dilp2 protein was accumulated in IPCs, the level of circulating Dilp2 was decreased, and insulin signaling was reduced in the fat body. In ex vivo fly brain culture with the human adiponectin, Dilp2 was secreted from IPCs. These results indicate that adiponectin receptor in insulin producing cells regulates insulin secretion and controls glucose and lipid metabolism in Drosophila melanogaster. This study demonstrates a new adipokine signaling in Drosophila and provides insights for the mammalian adiponectin receptor function in pancreatic beta cells, which could be useful for therapeutic application.

  9. Control of methionine metabolism by the SahR transcriptional regulator in Proteobacteria.

    Science.gov (United States)

    Novichkov, Pavel S; Li, Xiaoqing; Kuehl, Jennifer V; Deutschbauer, Adam M; Arkin, Adam P; Price, Morgan N; Rodionov, Dmitry A

    2014-01-01

    Sulphur is an essential element in the metabolism. The sulphur-containing amino acid methionine is a metabolic precursor for S-adenosylmethionine (SAM), which serves as a coenzyme for ubiquitous methyltrtansferases. Recycling of organic sulphur compounds, e.g. via the SAM cycle, is an important metabolic process that needs to be tightly regulated. Knowledge about transcriptional regulation of these processes is still limited for many free-living bacteria. We identified a novel transcription factor SahR from the ArsR family that controls the SAM cycle genes in diverse microorganisms from soil and aquatic ecosystems. By using comparative genomics, we predicted SahR-binding DNA motifs and reconstructed SahR regulons in the genomes of 62 Proteobacteria. The conserved core of SahR regulons includes all enzymes required for the SAM cycle: the SAH hydrolase AhcY, the methionine biosynthesis enzymes MetE/MetH and MetF, and the SAM synthetase MetK. By using a combination of experimental techniques, we validated the SahR regulon in the sulphate-reducing Deltaproteobacterium Desulfovibrio alaskensis. SahR functions as a negative regulator that responds to the S-adenosylhomocysteine (SAH). The elevated SAH level in the cell dissociates SahR from its DNA operators and induces the expression of SAM cycle genes. The effector-sensing domain in SahR is related to SAM-dependent methylases that are able to tightly bind SAH. SahR represents a novel type of transcriptional regulators for the control of sulphur amino acid metabolism.

  10. Social Competence and Parental Support as Mediators of the Link between Stress and Metabolic Control in Adolescents with Insulin-Dependent Diabetes Mellitus.

    Science.gov (United States)

    Hanson, Cindy L.; And Others

    1987-01-01

    Measured metabolic control, adherence, life stress, social competence, and parental support in adolescents (N=104) with insulin-dependent diabetes mellitus. Found that stress was directly associated with metabolic control, independent of the link between adherence and metabolic control. Social competence buffered negative association between…

  11. Exploring lysine riboswitch for metabolic flux control and improvement of L-lysine synthesis in Corynebacterium glutamicum.

    Science.gov (United States)

    Zhou, Li-Bang; Zeng, An-Ping

    2015-06-19

    Riboswitch, a regulatory part of an mRNA molecule that can specifically bind a metabolite and regulate gene expression, is attractive for engineering biological systems, especially for the control of metabolic fluxes in industrial microorganisms. Here, we demonstrate the use of lysine riboswitch and intracellular l-lysine as a signal to control the competing but essential metabolic by-pathways of lysine biosynthesis. To this end, we first examined the natural lysine riboswitches of Eschericia coli (ECRS) and Bacillus subtilis (BSRS) to control the expression of citrate synthase (gltA) and thus the metabolic flux in the tricarboxylic acid (TCA) cycle in E. coli. ECRS and BSRS were then successfully used to control the gltA gene and TCA cycle activity in a lysine producing strain Corynebacterium glutamicum LP917, respectively. Compared with the strain LP917, the growth of both lysine riboswitch-gltA mutants was slower, suggesting a reduced TCA cycle activity. The lysine production was 63% higher in the mutant ECRS-gltA and 38% higher in the mutant BSRS-gltA, indicating a higher metabolic flux into the lysine synthesis pathway. This is the first report on using an amino acid riboswitch for improvement of lysine biosynthesis. The lysine riboswitches can be easily adapted to dynamically control other essential but competing metabolic pathways or even be engineered as an "on-switch" to enhance the metabolic fluxes of desired metabolic pathways.

  12. [Plasma fructosamine to evaluate metabolic control among women with gestational diabetes].

    Science.gov (United States)

    Delgado M, Raúl; Novik A, Victoria; Cardemil M, Felipe; Santander A, Diego

    2011-11-01

    Metabolic control of diabetic pregnant women is assessed using glycated hemoglobin (HbAlc) levels and fasting blood sugar. Another glycated protein, namely fructosamine, can be an indicator of average glucose levels during the last three weeks. To evaluate plasma fructosamine as an indicator of glycemic control in women with gestational diabetes. Prospective cohort study of 41 pregnant women aged 30 to 37 years, with gestational and pre-gestational diabetes. Blood glucose, HbAlc, fructosamine were measured. Newborn weight, and other prenatal and postnatal variables, were used to evaluate the correlation between metabolic control and the presence or absence of macrosomia. The correlation observed between fructosamine and fasting blood glucose (r = 0.627, p < 0.001) was superior to that of HbA1c and blood glucose (r = 0.516, p < 0.001). No association was observed between macrosomia and levels of fructosamine, nor between the other studied variables. Fructosamine levels were not associated with macrosomia, but it could be better for the evaluation of glycemic control in patients with gestational diabetes since it allows short-term monitoring.

  13. A CONTROLLED METABOLIC DIET REDUCES CALCIUM OXALATE SUPERSATURATION BUT NOT OXALATE EXCRETION AFTER BARIATRIC SURGERY

    Science.gov (United States)

    Pang, Ran; Linnes, Michael; O’Connor, Helen M.; Li, Xujian; Bergstralh, Eric; Lieske, John C.

    2012-01-01

    Objective To identify the effect of controlled metabolic diet on reducing urinary calcium oxalate supersaturation in subjects with hyperoxaluric nephrolithiasis after potentially malabsorptive forms of bariatric surgery. Materials and Methods Subjects with a history of CaOx kidney stones and mild hyperoxaluria after bariatric surgery (n=9) collected baseline 24-hour urine samples while on a free choice diet. They were then placed on a controlled diet low in oxalate (70 – 80 mg/day), normal in calcium (1000 mg/day), and moderate in protein prior to 2 final 24-hour urine collections. Results Overall urinary CaOx supersaturation fell from 1.97 ± 0.49 delta Gibbs (DG) on the free choice diet to 1.13 ± 0.75 DG on the controlled diet (P0.05), contributing to the significant CaOx supersaturation change. Conclusions A controlled metabolic diet normal in calcium, moderate in protein and reduced in oxalate can positively impact urinary CaOx supersaturation after bariatric surgery. However, this diet did not appear to decrease urinary oxalate excretion. Therefore, restriction of dietary oxalate alone may not be enough to reduce urinary oxalate excretion to normal levels in this group of known enteric hyperoxaluric patients. Additional strategies may be necessary, such as use of oral calcium supplements as oxalate binders and a lower fat diet. PMID:22554593

  14. Controlled metabolic diet reduces calcium oxalate supersaturation but not oxalate excretion after bariatric surgery.

    Science.gov (United States)

    Pang, Ran; Linnes, Michael P; O'Connor, Helen M; Li, Xujian; Bergstralh, Eric; Lieske, John C

    2012-08-01

    To identify the effect of a controlled metabolic diet on reducing urinary calcium oxalate (CaOx) supersaturation in subjects with hyperoxaluric nephrolithiasis after potentially malabsorptive forms of bariatric surgery. Subjects with a history of CaOx kidney stones and mild hyperoxaluria after bariatric surgery (n = 9) collected baseline 24-hour urine samples while consuming a free choice diet. They were then instructed to consume a controlled diet low in oxalate (70-80 mg/d), normal in calcium (1000 mg/d), and moderate in protein before 2 final 24-hour urine collections. Overall, the urinary CaOx supersaturation decreased from 1.97 ± 0.49 delta Gibbs (DG) with the free choice diet to 1.13 ± 0.75 DG with the controlled diet (P .05), contributing to the significant CaOx supersaturation change. A controlled metabolic diet normal in calcium, moderate in protein, and reduced in oxalate can positively affect urinary CaOx supersaturation after bariatric surgery. However, this diet did not appear to decrease urinary oxalate excretion. Therefore, restriction of dietary oxalate alone might not be enough to reduce urinary oxalate excretion to normal levels in this group of patients with known enteric hyperoxaluria. Additional strategies could be necessary, such as the use of oral calcium supplements as oxalate binders and a lower fat diet. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Thyroid peroxidase antibodies in pregnant women with type 1 diabetes: impact on thyroid function, metabolic control and pregnancy outcome

    DEFF Research Database (Denmark)

    Vestgaard, Marianne; Nielsen, Lene Ringholm; Rasmussen, Åse Krogh;

    2008-01-01

    In pregnant women with type 1 diabetes, we evaluated whether the presence of thyroid peroxidase autoantibodies (anti-TPO) was associated with changes in thyroid function, metabolic control and pregnancy outcome....

  16. Thyroid peroxidase antibodies in pregnant women with type 1 diabetes: impact on thyroid function, metabolic control and pregnancy outcome

    DEFF Research Database (Denmark)

    Vestgaard, Marianne; Nielsen, Lene Ringholm; Rasmussen, Åse Krogh

    2008-01-01

    In pregnant women with type 1 diabetes, we evaluated whether the presence of thyroid peroxidase autoantibodies (anti-TPO) was associated with changes in thyroid function, metabolic control and pregnancy outcome....

  17. Lessons from September 8, 2011 Southwest America Blackout for Prevention and Control of Cascading Outages%美国“9·8”大停电对连锁故障防控技术的启示

    Institute of Scientific and Technical Information of China (English)

    方勇杰

    2012-01-01

    Based on the 2011 Southwest America blackout inquiry report, this paper presents a description of the event evolution and an analysis of technical causes leading to the cascade development from the point of view of prevention and control of cascading outages, including ineffectiveness of security analysis and preventive control, inadequacy of real-time situational awareness, unreasonabilitp of protection relay settings, inappropriateness of control system design and lack of coordination between protection and control. It concludes that several fundamental measures need to be strengthened, including a complete, thorough and timely understanding of system dynamic characteristics, coordination of protection and control actions, and improvement of simulation analysis.%叙述了2011年9月8日在美国西南地区电网发生的大停电事故演化过程,从连锁故障防控的视角分析了事故发展的技术原因,包括安全分析和预防控制技术欠缺、实时状态觉知能力不足、保护定值整定不合理、控制方案设置不当和保护与控制动作不协调。凝练了连锁故障防控技术需要加强的基础性工作,指出必须全面、深入、及时地掌握系统动态特性,协调保护控制动作,提高仿真分析精度。

  18. Contribution of family social support to the metabolic control of people with diabetes mellitus: A randomized controlled clinical trial.

    Science.gov (United States)

    Gomes, Lilian Cristiane; Coelho, Anna Claudia Martins; Gomides, Danielle Dos Santos; Foss-Freitas, Maria Cristina; Foss, Milton César; Pace, Ana Emilia

    2017-08-01

    This randomized controlled clinical trial aimed to evaluate the contribution of family social support to the clinical/metabolic control of people with type 2 diabetes mellitus. Diabetes mellitus is a chronic disease that requires continuous care in order for individuals to reach glycemic control, the primordial goal of treatment. Family social support is essential to the development of care skills and their maintenance. However, there are few studies that investigate the contribution of family social support to diabetes control. The study was developed between June 2011 and May 2013, and included 164 people who were randomized using simple randomization. The intervention group differed from the control group in that it included a family caregiver, who was recognized by the patient as a source of social support. The educational interventions received by people with diabetes mellitus were used as the basis of the education provided through telephone calls to patients' family members and caregivers, and their purpose was to encourage dialogue between the patients and their relatives about the topics related to diabetes. Regarding the clinical impact, the results showed that there was a greater reduction in blood pressure and glycated hemoglobin in the intervention group than in the control group, showing a positive effect on the control of the disease. Families should be incorporated into the care of people with diabetes mellitus and especially in health care programs, in particular those that can promote different forms of social support to strengthen the bond between family members. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Locomotor Adaptation Improves Balance Control, Multitasking Ability and Reduces the Metabolic Cost of Postural Instability

    Science.gov (United States)

    Bloomberg, J. J.; Peters, B. T.; Mulavara, A. P.; Brady, R. A.; Batson, C. D.; Miller, C. A.; Ploutz-Snyder, R. J.; Guined, J. R.; Buxton, R. E.; Cohen, H. S.

    2011-01-01

    During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The overall goal of our current project is to develop a sensorimotor adaptability training program to facilitate rapid adaptation to these environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene. It provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. Greater metabolic cost incurred during balance instability means more physical work is required during adaptation to new environments possibly affecting crewmembers? ability to perform mission critical tasks during early surface operations on planetary expeditions. The goal of this study was to characterize adaptation to a discordant sensory challenge across a number of performance modalities including locomotor stability, multi-tasking ability and metabolic cost. METHODS: Subjects (n=15) walked (4.0 km/h) on a treadmill for an 8 -minute baseline walking period followed by 20-minutes of walking (4.0 km/h) with support surface motion (0.3 Hz, sinusoidal lateral motion, peak amplitude 25.4 cm) provided by the treadmill/motion-base system. Stride frequency and auditory reaction time were collected as measures of locomotor stability and multi-tasking ability, respectively. Metabolic data (VO2) were collected via a portable metabolic gas analysis system. RESULTS: At the onset of lateral support surface motion, subj ects walking on our treadmill showed an increase in stride frequency and auditory reaction time indicating initial balance and multi-tasking disturbances. During the 20-minute adaptation period, balance control and multi-tasking performance improved. Similarly, throughout the 20-minute adaptation period, VO2 gradually

  20. Effect of fruit and vegetable concentrates on endothelial function in metabolic syndrome: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Ma Yingying

    2011-06-01

    Full Text Available Abstract Background and Objective Dehydrated fruit and vegetable concentrates provide an accessible form of phytonutrient supplementation that may offer cardioprotective effects. This study assessed the effects of two blends of encapsulated juice powder concentrates (with and without added berry powders on endothelial function in persons with metabolic syndrome, a risk factor for type 2 diabetes and cardiovascular disease. Methods Randomized, double blind, placebo controlled crossover clinical trial with three treatment arms. 64 adults with metabolic syndrome were enrolled and received 8-week sequences of each blend of the concentrates and placebo. The primary outcome measure was change in endothelial function (assessed as flow-mediated dilatation of the brachial artery 2 hr after consuming a 75 g glucose load, after 8-weeks of daily consumption (sustained or 2 hr after consumption of a single dose (acute. Secondary outcome measures included plasma glucose, serum insulin, serum lipids, and body weight. Results No significant between-group differences in endothelial function with daily treatment for 8 weeks were seen. No other significant treatment effects were discerned in glucose, insulin, lipids, and weight. Conclusion Encapsulated fruit and vegetable juice powder concentrates did not alter insulin or glucose measures in this sample of adults with metabolic syndrome. Trial Registration clinicaltrials.gov NCT01224743

  1. α/β-Hydrolase Domain 6 in the Ventromedial Hypothalamus Controls Energy Metabolism Flexibility

    Directory of Open Access Journals (Sweden)

    Alexandre Fisette

    2016-10-01

    Full Text Available α/β-Hydrolase domain 6 (ABHD6 is a monoacylglycerol hydrolase that degrades the endocannabinoid 2-arachidonoylglycerol (2-AG. Although complete or peripheral ABHD6 loss of function is protective against diet-induced obesity and insulin resistance, the role of ABHD6 in the central control of energy balance is unknown. Using a viral-mediated knockout approach, targeted endocannabinoid measures, and pharmacology, we discovered that mice lacking ABHD6 from neurons of the ventromedial hypothalamus (VMHKO have higher VMH 2-AG levels in conditions of endocannabinoid recruitment and fail to physiologically adapt to key metabolic challenges. VMHKO mice exhibited blunted fasting-induced feeding and reduced food intake, energy expenditure, and adaptive thermogenesis in response to cold exposure, high-fat feeding, and dieting (transition to a low-fat diet. Our findings identify ABHD6 as a regulator of the counter-regulatory responses to major metabolic shifts, including fasting, nutrient excess, cold, and dieting, thereby highlighting the importance of ABHD6 in the VMH in mediating energy metabolism flexibility.

  2. Environmental control of biological rhythms: effects on development, fertility and metabolism.

    Science.gov (United States)

    Amaral, F G; Castrucci, A M; Cipolla-Neto, J; Poletini, M O; Mendez, N; Richter, H G; Sellix, M T

    2014-09-01

    Internal temporal organisation properly synchronised to the environment is crucial for health maintenance. This organisation is provided at the cellular level by the molecular clock, a macromolecular transcription-based oscillator formed by the clock and the clock-controlled genes that is present in both central and peripheral tissues. In mammals, melanopsin in light-sensitive retinal ganglion cells plays a considerable role in the synchronisation of the circadian timing system to the daily light/dark cycle. Melatonin, a hormone synthesised in the pineal gland exclusively at night and an output of the central clock, has a fundamental role in regulating/timing several physiological functions, including glucose homeostasis, insulin secretion and energy metabolism. As such, metabolism is severely impaired after a reduction in melatonin production. Furthermore, light pollution during the night and shift work schedules can abrogate melatonin synthesis and impair homeostasis. Chronodisruption during pregnancy has deleterious effects on the health of progeny, including metabolic, cardiovascular and cognitive dysfunction. Developmental programming by steroids or steroid-mimetic compounds also produces internal circadian disorganisation that may be a significant factor in the aetiology of fertility disorders such as polycystic ovary syndrome. Thus, both early and late in life, pernicious alterations of the endogenous temporal order by environmental factors can disrupt the homeostatic function of the circadian timing system, leading to pathophysiology and/or disease. © 2014 British Society for Neuroendocrinology.

  3. Muscle insulin sensitivity and glucose metabolism are controlled by the intrinsic muscle clock★

    Science.gov (United States)

    Dyar, Kenneth A.; Ciciliot, Stefano; Wright, Lauren E.; Biensø, Rasmus S.; Tagliazucchi, Guidantonio M.; Patel, Vishal R.; Forcato, Mattia; Paz, Marcia I.P.; Gudiksen, Anders; Solagna, Francesca; Albiero, Mattia; Moretti, Irene; Eckel-Mahan, Kristin L.; Baldi, Pierre; Sassone-Corsi, Paolo; Rizzuto, Rosario; Bicciato, Silvio; Pilegaard, Henriette; Blaauw, Bert; Schiaffino, Stefano

    2013-01-01

    Circadian rhythms control metabolism and energy homeostasis, but the role of the skeletal muscle clock has never been explored. We generated conditional and inducible mouse lines with muscle-specific ablation of the core clock gene Bmal1. Skeletal muscles from these mice showed impaired insulin-stimulated glucose uptake with reduced protein levels of GLUT4, the insulin-dependent glucose transporter, and TBC1D1, a Rab-GTPase involved in GLUT4 translocation. Pyruvate dehydrogenase (PDH) activity was also reduced due to altered expression of circadian genes Pdk4 and Pdp1, coding for PDH kinase and phosphatase, respectively. PDH inhibition leads to reduced glucose oxidation and diversion of glycolytic intermediates to alternative metabolic pathways, as revealed by metabolome analysis. The impaired glucose metabolism induced by muscle-specific Bmal1 knockout suggests that a major physiological role of the muscle clock is to prepare for the transition from the rest/fasting phase to the active/feeding phase, when glucose becomes the predominant fuel for skeletal muscle. PMID:24567902

  4. The DC voltages balance control of the cascaded SVG based on controlled rectifiers%基于可控整流的级联SVG直流侧电压平衡控制

    Institute of Scientific and Technical Information of China (English)

    胡鑫; 陈劲操; 朱湘婧

    2015-01-01

    The voltage of capacitor could be unbalanced and unstable at the DC link in the cascaded multilevel static synchronous compensator ( STATCOM) .A strategy that the rectifiers control the voltage of capacitor is presented.The modeling establishment of the system and the design process of the controllers are listed.Also the model of system is built on the simulation software SIMPLORER platform.The result of the simulation shows that the rectifiers could effi-ciently compensate the power loss difference in the H bridges, which keeps the voltage of capacitors in benign balance and stability.The result also gives the comparison when the different control effect under the direct and the indirect current control, in which the advantages and the disadvantages are discussed.The strategy suggested is practical and feasible.%针对级联多电平静止无功补偿器( STATCOM)的直流侧电容电压存在平衡性和稳定性的问题,提出采用可控整流技术对电容电压进行控制. 给出了该系统数学模型的建立过程,研究了控制器的设计方法,并在SIMPLORER软件平台上完成了系统模型的搭建,仿真结果表明,整流器可以有效地补偿各个H桥中的损耗差异,使电容电压保持较好的平衡性和稳定性. 在仿真结果中,还给出了逆变侧在直接电流控制和间接电流控制下不同的控制效果,比较了它们的优缺点. 具有一定的实用性和可行性.

  5. 级联型多电平变换器单元电路控制策略仿真%Simulation of control strategy of cascade multilevel inverter cell circuit

    Institute of Scientific and Technical Information of China (English)

    郭殿林; 王欢; 陈国民

    2012-01-01

    针对级联型多电平变换器需要四象限运行的工况,提出以双H桥的电压胞拓扑作为多电平变换器单元电路的方案。其前H桥为整流器,采用滞环电流控制策略实现直流电压稳定和近似单位功率因数的双向能量流动;后H桥为逆变器,采用载波相移SPWM技术。通过建立整流器的滞环电流控制模型和三单元级联多电平逆变器相移技术控制模型,对变换器进行双向能量传输运行的过渡过程分析和逆变器输出级联电压波形分析。仿真结果表明该拓扑及控制策略满足四象限运行要求。%In response to the requirement of four quadrant operation conditions by cascade type multilever converter,this paper proposes the double H bridge cell voltage topology used as multilever converter unit circuit.It consists of front H bridge which works as rectifier,capable of realizing dc voltage stability and approximate unit of power factor two-way energy flow using hysteresis current control strategy,and rear H bridge which function as inverter adopting carrier phase shift SPWM technology.The paper introduces an analysis of transition process of two-way energy transmission operation of the converter and analysis of the voltage waveform of inverter output cascade by developing the rectifier hysteresis current control model and three unit cascade multilevel inverter phase shift technology control model.The simulation results show that the topology and the control strategy meet the requirements of the four quadrant operation.

  6. Hypoxic regulation of hand1 controls the fetal-neonatal switch in cardiac metabolism.

    Directory of Open Access Journals (Sweden)

    Ross A Breckenridge

    2013-09-01

    Full Text Available Cardiomyocytes are vulnerable to hypoxia in the adult, but adapted to hypoxia in utero. Current understanding of endogenous cardiac oxygen sensing pathways is limited. Myocardial oxygen consumption is determined by regulation of energy metabolism, which shifts from glycolysis to lipid oxidation soon after birth, and is reversed in failing adult hearts, accompanying re-expression of several "fetal" genes whose role in disease phenotypes remains unknown. Here we show that hypoxia-controlled expression of the transcription factor Hand1 determines oxygen consumption by inhibition of lipid metabolism in the fetal and adult cardiomyocyte, leading to downregulation of mitochondrial energy generation. Hand1 is under direct transcriptional control by HIF1α. Transgenic mice prolonging cardiac Hand1 expression die immediately following birth, failing to activate the neonatal lipid metabolising gene expression programme. Deletion of Hand1 in embryonic cardiomyocytes results in premature expression of these genes. Using metabolic flux analysis, we show that Hand1 expression controls cardiomyocyte oxygen consumption by direct transcriptional repression of lipid metabolising genes. This leads, in turn, to increased production of lactate from glucose, decreased lipid oxidation, reduced inner mitochondrial membrane potential, and mitochondrial ATP generation. We found that this pathway is active in adult cardiomyocytes. Up-regulation of Hand1 is protective in a mouse model of myocardial ischaemia. We propose that Hand1 is part of a novel regulatory pathway linking cardiac oxygen levels with oxygen consumption. Understanding hypoxia adaptation in the fetal heart may allow development of strategies to protect cardiomyocytes vulnerable to ischaemia, for example during cardiac ischaemia or surgery.

  7. Metabolic control analysis of biochemical pathways based on a thermokinetic description of reaction rates

    DEFF Research Database (Denmark)

    Nielsen, Jens Bredal

    1997-01-01

    Metabolic control analysis is a powerful technique for the evaluation of flux control within biochemical pathways. Its foundation is the elasticity coefficients and the flux control coefficients (FCCs). On the basis of a thermokinetic description of reaction rates it is here shown...... affinity. This parameter can often be determined from experiments in vitro. The methodology is applicable only to the analysis of simple two-step pathways, but in many cases larger pathways can be lumped into two overall conversions. In cases where this cannot be done it is necessary to apply an extension...... be much more widely applied, although it was originally based on linearized kinetics. The methodology of determining elasticity coefficients directly from pool levels is illustrated with an analysis of the first two steps of the biosynthetic pathway of penicillin. The results compare well with previous...

  8. Disease and the family: differences in metabolic control of diabetes mellitus between men and women.

    Science.gov (United States)

    Mercado, F J; Vargas, P N

    1989-01-01

    This study shows differences between males and females in metabolic control of diabetes mellitus. The 30 subjects studied (15 men and 15 women) were type II diabetics, peasants, ages 40-62, all residents of Cihuatlan, Jalisco, Mexico. Fifty percent (50%) of the diabetics were found to have poor control (as defined by elevated fasting blood sugar levels). The percentage varied greatly according to sex: 86.6% of the females have poor control compared to 13.3% of the males. Compliance or non-compliance to a prescribed diet was found to be related to whether or not members of the family participate in the preparation of diet and support the diabetic subject in following the therapeutic plan. One hundred percent of the males have their food prepared specially for them by a family member while only 13% of the females receive this type of support.

  9. Cascade Distillation System Development

    Science.gov (United States)

    Callahan, Michael R.; Sargushingh, Miriam; Shull, Sarah

    2014-01-01

    NASA's Advanced Exploration Systems (AES) Life Support System (LSS) Project is chartered with de-veloping advanced life support systems that will ena-ble NASA human exploration beyond low Earth orbit (LEO). The goal of AES is to increase the affordabil-ity of long-duration life support missions, and to re-duce the risk associated with integrating and infusing new enabling technologies required to ensure mission success. Because of the robust nature of distillation systems, the AES LSS Project is pursuing develop-ment of the Cascade Distillation Subsystem (CDS) as part of its technology portfolio. Currently, the system is being developed into a flight forward Generation 2.0 design.

  10. Effect of growth regulators on 'Brookfield' apple gas diffusion and metabolism under controlled atmosphere storage

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2014-05-01

    Full Text Available The objective of this work was to evaluate the effect of growth regulators on gas diffusion and on metabolism of 'Brookfield' apple, and to determine their correlation with quality characteristics of fruit stored in controlled atmosphere. A completely randomized design was used with four replicates. After eight months of storage, the effects of water (control, aminoethoxyvinylglycine (AVG, AVG + ethephon, AVG + naphthaleneacetic acid (NAA, ethephon + NAA, sole NAA, 1-MCP, ethylene absorption by potassium permanganate (ABS, AVG + ABS, and of AVG + 1-MCP - applied at different rates and periods - were evaluated on: gas diffusion rate, ethylene production, respiratory rate, internal ethylene concentration, internal CO2 content, mealiness, and intercellular space. Fruit from the control and sole NAA treatments had the highest mealiness occurrence. Growth regulators significantly changed the gaseous diffusion through the pulp of 'Brookfield' apple, mainly in the treatment AVG + ABS, which kept the highest gas diffusion rate. NAA spraying in the field, with or without another growth regulator, increased ripening metabolism by rising ethylene production and respiration rate, and reduced gas diffusion during shelf life. AVG spraying cannot avoid the ethephon effect during the ripening process, and reduces both the internal space and mealiness incidence, but it is not able to induce ethylene production or to increase respiration rates.

  11. Mitochondrial metabolism and the control of vascular smooth muscle cell proliferation

    Directory of Open Access Journals (Sweden)

    Mario eChiong

    2014-12-01

    Full Text Available Differentiation and dedifferentiation of vascular smooth muscle cells (VSMCs are essential processes of vascular development. VSMCs have biosynthetic, proliferative and contractile roles in the vessel wall. Alterations in the differentiated state of the VSMCs play a critical role in the pathogenesis of a variety of cardiovascular diseases, including atherosclerosis, hypertension and vascular stenosis. This review provides an overview of the current state of knowledge of molecular mechanisms involved in the control of VSMC proliferation, with particular focus on mitochondrial metabolism. Mitochondrial activity can be controlled by regulating mitochondrial dynamics, i.e. mitochondrial fusion and fission, and by regulating mitochondrial calcium handling through the interaction with the endoplasmic reticulum (ER. Alterations in both VSMC proliferation and mitochondrial function can be triggered by dysregulation of mitofusin-2, a small GTPase associated with mitochondrial fusion and mitochondrial-ER interaction. Several lines of evidence highlight the relevance of mitochondrial metabolism in the control of VSMC proliferation, indicating a new area to be explored in the treatment of vascular diseases.

  12. Metabolic control and bone health in adolescents with type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Mohan Subburaman

    2011-10-01

    Full Text Available Abstract Background Adults with type 1 diabetes (T1D have decreased bone mineral density (BMD and increased fracture risk, yet the etiologies remain elusive. Early detection of derangements in bone biomarkers during adolescence could lead to timely recognition. In adolescents with T1D, we evaluated the relationships between metabolic control, BMD, and bone anabolic and turnover markers. Methods Cross-sectional study of 57 adolescent subjects with T1D who had HbA1c consistently ≥ 9% (Poor Control, PC n = 27 or Results There were no differences between HbA1c groups in BMD, components of the IGF system, or 25-hydroxyvitamin D status. The prevalence of 25-hydroxyvitamin D abnormalities was similar to that seen in the general adolescent population. Few patients met the recommended dietary allowance (RDA for vitamin D or calcium. Conclusions These data provide no evidence of association between degree of metabolic control and BMD in adolescents with T1D. Adolescents with T1D have a high prevalence of serum 25-hydroxyvitamin D abnormalities. Longitudinal studies are needed to evaluate the predictive value of vitamin D abnormalities on fracture risk.

  13. Interband cascade lasers

    Science.gov (United States)

    Vurgaftman, I.; Weih, R.; Kamp, M.; Meyer, J. R.; Canedy, C. L.; Kim, C. S.; Kim, M.; Bewley, W. W.; Merritt, C. D.; Abell, J.; Höfling, S.

    2015-04-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron-hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3-6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm-2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT.

  14. Unsteady turbulence cascades

    Science.gov (United States)

    Goto, Susumu; Vassilicos, J. C.

    2016-11-01

    We have run a total of 311 direct numerical simulations (DNSs) of decaying three-dimensional Navier-Stokes turbulence in a periodic box with values of the Taylor length-based Reynolds number up to about 300 and an energy spectrum with a wide wave-number range of close to -5 /3 power-law dependence at the higher Reynolds numbers. On the basis of these runs, we have found a critical time when (i) the rate of change of the square of the integral length scale turns from increasing to decreasing, (ii) the ratio of interscale energy flux to high-pass filtered turbulence dissipation changes from decreasing to very slowly increasing in the inertial range, (iii) the signature of large-scale coherent structures disappears in the energy spectrum, and (iv) the scaling of the turbulence dissipation changes from the one recently discovered in DNSs of forced unsteady turbulence and in wind tunnel experiments of turbulent wakes and grid-generated turbulence to the classical scaling proposed by G. I. Taylor [Proc. R. Soc. London, Ser. A 151, 421 (1935), 10.1098/rspa.1935.0158] and A. N. Kolmogorov [Dokl. Akad. Nauk SSSR 31, 538 (1941)]. Even though the customary theoretical basis for this Taylor-Kolmogorov scaling is a statistically stationary cascade where large-scale energy flux balances dissipation, this is not the case throughout the entire time range of integration in all our DNS runs. The recently discovered dissipation scaling can be reformulated physically as a situation in which the dissipation rates of the small and large scales evolve together. We advance two hypotheses that may form the basis of a theoretical approach to unsteady turbulence cascades in the presence of large-scale coherent structures.

  15. Endothelial dysfunction and metabolic control in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Rodríguez-Mañas, L; Angulo, J; Peiró, C; Llergo, J L; Sánchez-Ferrer, A; López-Dóriga, P; Sánchez-Ferrer, C F

    1998-04-01

    1. The aim of this work was to study the influence of the metabolic control, estimated by the levels of glycosylated haemoglobin in total blood samples (HbA1c), in developing vascular endothelial dysfunction in streptozotocin-induced diabetic rats. Four groups of animals with different levels of insulin treatment were established, by determining HbA1c values in 5.5 to 7.4%, 7.5 to 9.4%, 9.5 to 12% and > 12%, respectively. 2. The parameters analysed were: (1) the endothelium-dependent relaxations to acetylcholine (ACh) in isolated aorta and mesenteric microvessels; (2) the vasodilator responses to exogenous nitric oxide (NO) in aorta: and (3) the existence of oxidative stress by studying the influence of the free radical scavenger superoxide dismutase (SOD) on the vasodilator responses to both ACh and NO. 3. In both isolated aortic segments and mesenteric microvessels, the endothelium-mediated concentration-dependent relaxant responses elicited by ACh were significantly decreased when the vessels were obtained from diabetic animals but only with HbA1c values higher than 7.5%. There was a high correlation between HbA1c levels and the impairment of ACh-induced relaxations, measured by pD2 values. 4. The concentration-dependent vasorelaxant responses to NO in endothelium-denuded aortic segments were significantly reduced only in vessels from diabetic animals with HbA1c values higher than 7.5%. Again, a very high correlation was found between the HbA1c values and pD2 for NO-evoked responses. 5. In the presence of SOD, the responses to ACh or NO were only increased in the segments from diabetic rats with HbA1c levels higher than 7.5%, but not in those from non-diabetic or diabetic rats with a good metabolic control (HbA1c levels metabolic control of diabetes, estimated by the levels of HbA1c; and (2) an increased production of superoxide anions in the vascular wall of the diabetic rats, which is also related to the metabolic control of the disease.

  16. [Risk factors for metabolic syndrome in a case control study in Temuco, Chile].

    Science.gov (United States)

    Philco L, Patricia; Serón S, Pamela; Muñoz N, Sergio; Navia B, Pilar; Lanas Z, Fernando

    2012-03-01

    Metabolic syndrome is becoming an important public health problem in affluent societies. To identify factors associated to metabolic syndrome in a Southern Chilean city. Using a case control design, 200 participants, aged 35 to 70 years with at least three criteria for metabolic syndrome according to the National Cholesterol Education Program (NCEP_ATPIII) and 200 subjects with less than three criteria, were studied. Both groups were compared in terms of ethnic background, educational level, family history of diabetes and coronary artery disease, menopausal status, smoking, stress and depression, physical activity, changes in body mass index in the last five years and diet. Among subjects aged more than 54 years, among males and among overweight individuals, having a Mapuche origin was a risk factor with odds ratios (OR) of 7.2; 88 and 3.9 respectively. Among subjects aged more than 54 years, among women and among overweight individuals, a family history of diabetes was a risk factor with OR of 17.7; 3.2 and 3.9 respectively. Among subjects aged more than 54 years and among women a change in body mass index of more than three points was a risk factor with OR of 12.5 and 7.4, respectively. Depression also was a risk factor among subjects aged more than 54 years (OR 3.3). Regular consumption of wine was a protective factor among participants of more than 54 years, with an OR of 0.17. The risk factors for metabolic syndrome detected in this group of participants, were having a Mapuche origin, a family history of diabetes mellitus and depression. Wine consumption was associated with a lower risk.

  17. Thermodynamic and Probabilistic Metabolic Control Analysis of Riboflavin (Vitamin B₂) Biosynthesis in Bacteria.

    Science.gov (United States)

    Birkenmeier, Markus; Mack, Matthias; Röder, Thorsten

    2015-10-01

    In this study, we applied a coupled in silico thermodynamic and probabilistic metabolic control analysis methodology to investigate the control mechanisms of the commercially relevant riboflavin biosynthetic pathway in bacteria. Under the investigated steady-state conditions, we found that several enzyme reactions of the pathway operate far from thermodynamic equilibrium (transformed Gibbs energies of reaction below about -17 kJ mol(-1)). Using the obtained thermodynamic information and applying enzyme elasticity sampling, we calculated the distributions of the scaled concentration control coefficients (CCCs) and scaled flux control coefficients (FCCs). From the statistical analysis of the calculated distributions, we inferred that the control over the riboflavin producing flux is shared among several enzyme activities and mostly resides in the initial reactions of the pathway. More precisely, the guanosine triphosphate (GTP) cyclohydrolase II activity, and therefore the bifunctional RibA protein of Bacillus subtilis because it catalyzes this activity, appears to mainly control the riboflavin producing flux (mean FCCs = 0.45 and 0.55, respectively). The GTP cyclohydrolase II activity and RibA also exert a high positive control over the riboflavin concentration (mean CCCs = 2.43 and 2.91, respectively). This prediction is consistent with previous findings for microbial riboflavin overproducing strains.

  18. Large-capacity cascaded bipolar BESS and its control strategy%级联双极型大容量电池储能系统及其控制策略

    Institute of Scientific and Technical Information of China (English)

    徐云飞; 肖湘宁; 孙雅旻; 龙云波; 徐永海

    2016-01-01

    针对多储能单元级联的高电压、大容量应用场合,提出一种级联双级型电池储能系统.该系统由AC/DC与DC/DC两级变换器构成,且均采用模块化多电平级联结构,具有结构紧凑、可靠性高、能量控制简单等优点.建立该系统的数学模型并分析其工作原理及约束条件,设计了多电池组荷电状态(SOC)均衡策略,有效解决了电池过充或过放的问题;针对储能系统在不对称运行条件下直流电流波动过大的问题,提出一种直流波动抑制的前馈控制策略.最后,基于RTDS对该系统及控制策略进行数字-物理闭环仿真,验证了系统结构和控制策略的有效性.%A cascaded bipolar BESS(Battery Energy Storage System) is proposed for the high-voltage and large-capacity applications of multiple cascaded energy storage units,which is composed of an AC/DC converter and a DC/DC converter.Both converters adopt the multilevel modular cascading structure,which is compact,highly reliable and simple for energy control.A mathematical model is built for the system,its working principle and constraints are analyzed,and the SOC(State Of Charge) balancing strategy is designed for multiple battery packs to avoid the over-charging and over-discharging.Aiming at the large DC current fluctuation of BESS during its operation in asymmetric conditions,a feedward control strategy is proposed to smooth the DC current fluctuation.The digital-physical closed-loop simulation based on RTDS verifies the effectiveness of the proposed system structure and control strategies.

  19. Transonic Cascade Measurements to Support Analytical Modeling

    Science.gov (United States)

    2007-11-02

    RECEIVED JUL 0 12005 FINAL REPORT FOR: AFOSR GRANT F49260-02-1-0284 TRANSONIC CASCADE MEASUREMENTS TO SUPPORT ANALYTICAL MODELING Paul A. Durbin ...PAD); 650-723-1971 (JKE) durbin @vk.stanford.edu; eaton@vk.stanford.edu submitted to: Attn: Dr. John Schmisseur Air Force Office of Scientific Research...both spline and control points for subsequent wall shape definitions. An algebraic grid generator was used to generate the grid for the blade-wall

  20. Engineering a Lysine-ON Riboswitch for Metabolic Control of Lysine Production in Corynebacterium glutamicum.

    Science.gov (United States)

    Zhou, Li-Bang; Zeng, An-Ping

    2015-12-18

    Riboswitches are natural RNA elements that regulate gene expression by binding a ligand. Here, we demonstrate the possibility of altering a natural lysine-OFF riboswitch from Eschericia coli (ECRS) to a synthetic lysine-ON riboswitch and using it for metabolic control. To this end, a lysine-ON riboswitch library was constructed using tetA-based dual genetic selection. After screening the library, the functionality of the selected lysine-ON riboswitches was examined using a report gene, lacZ. Selected lysine-ON riboswitches were introduced into the lysE gene (encoding a lysine transport protein) of Corynebacterium glutamicum and used to achieve dynamic control of lysine transport in a recombinant lysine-producing strain, C. glutamicum LPECRS, which bears a deregulated aspartokinase and a lysine-OFF riboswitch for dynamic control of the enzyme citrate synthase. Batch fermentation results of the strains showed that the C. glutamicum LPECRS strain with an additional lysine-ON riboswitch for the control of lysE achieved a 21% increase in the yield of lysine compared to that of the C. glutamicum LPECRS strain and even a 89% increase in yield compared to that of the strain with deregulated aspartokinase. This work provides a useful approach to generate lysine-ON riboswitches for C. glutamicum metabolic engineering and demonstrates for the first time a synergetic effect of lysine-ON and -OFF riboswitches for improving lysine production in this industrially important microorganism. The approach can be used to dynamically control other genes and can be applied to other microorganisms.

  1. SVPWM Control Algorithm of Cascaded Multilevel Inverter%级联型多电平逆变器SVPWM控制研究

    Institute of Scientific and Technical Information of China (English)

    霍海龙; 韩如成; 苑伟华

    2015-01-01

    Based on the topology structure of H-bridge cascaded multi-level inverter,the decomposition of primary structure indicated that the essence of output voltage of inverter is the difference value between the output voltage of two-level inverter group formed by left bridge arms of all H-bridge and right bridge arms of all H-bridge. A suitable modulation of phase-shifted space vector pulse width modulation( SVPWM)was introduced for H-bridge cascaded multi-level inverter by combining phased-shifted principle and space vector pulse width modulation( SVM ). The output characteristics of line voltage and phase voltage were analyzed by using frequency domain transform of Doub-le Fourier transform method. A simulation model was built on Matlab/Simulink platform according to phase shift SVPWM method,the simulation results verified the correctness of the method,and the impact on output levels of SVPWM ,amplitude of fundamental and total harmonic of voltage was analyzed when phase-shifting modulation ratio M changed.%由H桥级联型逆变器主电路结构,分析出了逆变器电压输出实质可看作其各H桥单元左、右桥臂矢量形成的三相两电平逆变器组输出电压之差。把相移原理和空间矢量脉宽调制技术( SVM)结合推导出了适合于H桥单元串联叠加逆变器的相移空间电压矢量调制技术。利用双重傅里叶变换( DFT)的频域变换方法分析了相、线电压的输出特性。在Matlab/Simulink仿真平台上搭建相移SVPWM方法的仿真模型,验证了该方法的有效性和正确性,并分析了载波调制比M变化对相移SVPWM的电压输出电平数、基波幅值和电压总谐波畸变的影响。

  2. Primary metabolism and its control in streptomycetes: a most unusual group of bacteria.

    Science.gov (United States)

    Hodgson, D A

    2000-01-01

    Streptomycetes are Gram-positive bacteria with a unique capacity for the production of a multitude of varied and complex secondary metabolites. They also have a complex life cycle including differentiation into at least three distinct cell types. Whilst much attention has been paid to the pathways and regulation of secondary metabolism, less has been paid to the pathways and the regulation of primary metabolism, which supplies the precursors. With the imminent completion of the total genome sequence of Streptomyces coelicolor A3(2), we need to understand the pathways of primary metabolism if we are to understand the role of newly discovered genes. This review is written as a contribution to supplying these wants. Streptomycetes inhabit soil, which, because of the high numbers of microbial competitors, is an oligotrophic environment. Soil nutrient levels reflect the fact that plant-derived material is the main nutrient input; i.e. it is carbon-rich and nitrogen- and phosphate-poor. Control of streptomycete primary metabolism reflects the nutrient availability. The variety and multiplicity of carbohydrate catabolic pathways reflects the variety and multiplicity of carbohydrates in the soil. This multiplicity of pathways has led to investment by streptomycetes in pathway-specific and global regulatory networks such as glucose repression. The mechanism of glucose repression is clearly different from that in other bacteria. Streptomycetes feed by secreting complexes of extracellular enzymes that break down plant cell walls to release nutrients. The induction of these enzyme complexes is often coordinated by inducers that bear no structural relation to the substrate or product of any particular enzyme in the complex; e.g. a product of xylan breakdown may induce cellulase production. Control of amino acid catabolism reflects the relative absence of nitrogen catabolites in soil. The cognate amino acid induces about half of the catabolic pathways and half are constitutive

  3. Comparative genomic reconstruction of transcriptional networks controlling central metabolism in the Shewanella genus

    Directory of Open Access Journals (Sweden)

    Kovaleva Galina

    2011-06-01

    Full Text Available Abstract Background Genome-scale prediction of gene regulation and reconstruction of transcriptional regulatory networks in bacteria is one of the critical tasks of modern genomics. The Shewanella genus is comprised of metabolically versatile gamma-proteobacteria, whose lifestyles and natural environments are substantially different from Escherichia coli and other model bacterial species. The comparative genomics approaches and computational identification of regulatory sites are useful for the in silico reconstruction of transcriptional regulatory networks in bacteria. Results To explore conservation and variations in the Shewanella transcriptional networks we analyzed the repertoire of transcription factors and performed genomics-based reconstruction and comparative analysis of regulons in 16 Shewanella genomes. The inferred regulatory network includes 82 transcription factors and their DNA binding sites, 8 riboswitches and 6 translational attenuators. Forty five regulons were newly inferred from the genome context analysis, whereas others were propagated from previously characterized regulons in the Enterobacteria and Pseudomonas spp.. Multiple variations in regulatory strategies between the Shewanella spp. and E. coli include regulon contraction and expansion (as in the case of PdhR, HexR, FadR, numerous cases of recruiting non-orthologous regulators to control equivalent pathways (e.g. PsrA for fatty acid degradation and, conversely, orthologous regulators to control distinct pathways (e.g. TyrR, ArgR, Crp. Conclusions We tentatively defined the first reference collection of ~100 transcriptional regulons in 16 Shewanella genomes. The resulting regulatory network contains ~600 regulated genes per genome that are mostly involved in metabolism of carbohydrates, amino acids, fatty acids, vitamins, metals, and stress responses. Several reconstructed regulons including NagR for N-acetylglucosamine catabolism were experimentally validated in S

  4. Statistical analysis of cascading failures in power grids

    Energy Technology Data Exchange (ETDEWEB)

    Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

    2010-12-01

    We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

  5. In vivo identification of the steps that control energy metabolism and survival of Entamoeba histolytica.

    Science.gov (United States)

    Pineda, Erika; Encalada, Rusely; Vázquez, Citlali; Néquiz, Mario; Olivos-García, Alfonso; Moreno-Sánchez, Rafael; Saavedra, Emma

    2015-01-01

    The steps that control the Entamoeba histolytica glycolytic flux were here identified by elasticity analysis, an experimental approach of metabolic control analysis. The concentrations of glycolytic metabolites were gradually varied in live trophozoites by (a) feeding with different glucose concentrations and (b) inhibiting the final pathway steps; in parallel, the changes in the pathway flux were determined. From the metabolite concentration-flux relationship, the elasticity coefficients of individual or groups of pathway reactions were determined and used to calculate their respective degrees of control on the glycolytic flux (flux control coefficients). The results indicated that the pathway flux was mainly controlled (72-86%) by the glucose transport/hexokinase/glycogen degradation group of reactions and by bifunctional aldehyde-alcohol dehydrogenase (ADHE; 18%). Further, inhibition of the first pathway reactions with 2-deoxyglucose (2DOG) decreased the glycolytic flux and ATP content by 75% and 50%, respectively. Cell viability was also decreased by 2DOG (25%) and more potently (50%) by 2DOG plus the ADHE inhibitor tetraethylthiuram disulfide (disulfiram). Biosate as an alternative carbon (amino acid) source was unable to replace glucose for ATP supply, which indicated that glucose was the main nutrient for amoebal ATP synthesis and survival. These results indicated that glycolysis in the parasite is mainly controlled by the initial pathway reactions and that their inhibition can decrease the parasite energy load and survival.

  6. Temporal and fluoride control of secondary metabolism regulates cellular organofluorine biosynthesis.

    Science.gov (United States)

    Walker, Mark C; Wen, Miao; Weeks, Amy M; Chang, Michelle C Y

    2012-09-21

    Elucidating mechanisms of natural organofluorine biosynthesis is essential for a basic understanding of fluorine biochemistry in living systems as well as for expanding biological methods for fluorine incorporation into small molecules of interest. To meet this goal we have combined massively parallel sequencing technologies, genetic knockout, and in vitro biochemical approaches to investigate the fluoride response of the only known genetic host of an organofluorine-producing pathway, Streptomyces cattleya. Interestingly, we have discovered that the major mode of S. cattleya's resistance to the fluorinated toxin it produces, fluoroacetate, may be due to temporal control of production rather than the ability of the host's metabolic machinery to discriminate between fluorinated and non-fluorinated molecules. Indeed, neither the acetate kinase/phosphotransacetylase acetate assimilation pathway nor the TCA cycle enzymes (citrate synthase and aconitase) exclude fluorinated substrates based on in vitro biochemical characterization. Furthermore, disruption of the fluoroacetate resistance gene encoding a fluoroacetyl-CoA thioesterase (FlK) does not appear to lead to an observable growth defect related to organofluorine production. By showing that a switch in central metabolism can mediate and control molecular fluorine incorporation, our findings reveal a new potential strategy toward diversifying simple fluorinated building blocks into more complex products.

  7. Genetic control of a cytochrome P450 metabolism-based herbicide resistance mechanism in Lolium rigidum.

    Science.gov (United States)

    Busi, R; Vila-Aiub, M M; Powles, S B

    2011-05-01

    The dynamics of herbicide resistance evolution in plants are influenced by many factors, especially the biochemical and genetic basis of resistance. Herbicide resistance can be endowed by enhanced rates of herbicide metabolism because of the activity of cytochrome P450 enzymes, although in weedy plants the genetic control of cytochrome P450-endowed herbicide resistance is poorly understood. In this study we have examined the genetic control of P450 metabolism-based herbicide resistance in a well-characterized Lolium rigidum biotype. The phenotypic resistance segregation in herbicide resistant and susceptible parents, F1, F2 and backcross (BC) families was analyzed as plant survival following treatment with the chemically unrelated herbicides diclofop-methyl or chlorsulfuron. Dominance and nuclear gene inheritance was observed in F1 families when treated at the recommended field doses of both herbicides. The segregation values of P450 herbicide resistance phenotypic traits observed in F2 and BC families was consistent with resistance endowed by two additive genes in most cases. In obligate out-crossing species such as L. rigidum, herbicide selection can easily result in accumulation of resistance genes within individuals.

  8. Zinc Status Biomarkers and Cardiometabolic Risk Factors in Metabolic Syndrome: A Case Control Study

    Directory of Open Access Journals (Sweden)

    Erika P. S. Freitas

    2017-02-01

    Full Text Available Metabolic syndrome (MS involves pathophysiological alterations that might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic factors in patients with MS. Our case control study included 88 patients with MS and 37 controls. We performed clinical and anthropometric assessments and obtained lipid, glycemic, and inflammatory profiles. We also evaluated zinc intake, plasma zinc, erythrocyte zinc, and 24-h urinary zinc excretion. The average zinc intake was significantly lower in the MS group (p < 0.001. Regression models indicated no significant differences in plasma zinc concentration (all p > 0.05 between the two groups. We found significantly higher erythrocyte zinc concentration in the MS group (p < 0.001 independent from co-variable adjustments. Twenty-four hour urinary zinc excretion was significantly higher in the MS group (p = 0.008, and adjustments for age and sex explained 21% of the difference (R2 = 0.21, p < 0.001. There were significant associations between zincuria and fasting blood glucose concentration (r = 0.479, waist circumference (r = 0.253, triglyceride concentration (r = 0.360, glycated hemoglobin concentration (r = 0.250, homeostatic model assessment—insulin resistance (r = 0.223, and high-sensitivity C-reactive protein concentration (r = 0.427 (all p < 0.05 in the MS group. Patients with MS had alterations in zinc metabolism mainly characterized by an increase in erythrocyte zinc and higher zincuria.

  9. Fetal hemoglobin levels are related to metabolic control in diabetic subjects

    Directory of Open Access Journals (Sweden)

    Pardini V.C.

    1999-01-01

    Full Text Available We have investigated the relationship between fetal hemoglobin (HbF levels and metabolic control in subjects with insulin-dependent (N = 79 and non-insulin-dependent diabetes mellitus (N = 242. HbF and hemoglobin A1c (HbA1c levels were increased in subjects with type 1 and type 2 diabetes as compared to levels in nondiabetic individuals (P<0.0001, and were significantly higher in type 1 than in type 2 diabetes subjects. Lower levels of HbA1c and HbF were observed in type 2 diabetes subjects treated by diet, intermediate levels in those treated with oral hypoglycemic agents, and higher levels in those treated with insulin. HbF and HbA1c levels were correlated in type 1 diabetes (R2 = 0.57, P<0.0001 and type 2 diabetes (R2 = 0.58, P<0.0001 subjects. Following intense treatment, twelve diabetic patients showed significant improvement both in HbA1c and HbF values. We conclude that increased HbF levels reflect poor metabolic control in subjects with diabetes mellitus.

  10. Embryonic MicroRNA-369 Controls Metabolic Splicing Factors and Urges Cellular Reprograming.

    Directory of Open Access Journals (Sweden)

    Masamitsu Konno

    Full Text Available Noncoding microRNAs inhibit translation and lower the transcript stability of coding mRNA, however miR-369 s, in aberrant silencing genomic regions, stabilizes target proteins under cellular stress. We found that in vitro differentiation of embryonic stem cells led to chromatin methylation of histone H3K4 at the miR-369 region on chromosome 12qF in mice, which is expressed in embryonic cells and is critical for pluripotency. Proteomic analyses revealed that miR-369 stabilized translation of pyruvate kinase (Pkm2 splicing factors such as HNRNPA2B1. Overexpression of miR-369 stimulated Pkm2 splicing and enhanced induction of cellular reprogramming by induced pluripotent stem cell factors, whereas miR-369 knockdown resulted in suppression. Furthermore, immunoprecipitation analysis showed that the Argonaute complex contained the fragile X mental retardation-related protein 1 and HNRNPA2B1 in a miR-369-depedent manner. Our findings demonstrate a unique role of the embryonic miR-369-HNRNPA2B1 axis in controlling metabolic enzyme function, and suggest a novel pathway linking epigenetic, transcriptional, and metabolic control in cell reprogramming.

  11. Hypoglycemia in pregnant women with type 1 diabetes - Predictors and role of metabolic control

    DEFF Research Database (Denmark)

    Nielsen, L.R.; Johansen, M.; Pedersen-Bjergaard, U.;

    2008-01-01

    OBJECTIVE- In pregnancy with type 1 diabetes, we evaluated occurrence of mild and severe hypoglycemia and analyzed the influence of strict metabolic control, nausea, Vomiting, and other potential predictors of occurrence of severe hypoglycemia. RESEARCH DESIGN AND METHODS- A prospective observati......OBJECTIVE- In pregnancy with type 1 diabetes, we evaluated occurrence of mild and severe hypoglycemia and analyzed the influence of strict metabolic control, nausea, Vomiting, and other potential predictors of occurrence of severe hypoglycemia. RESEARCH DESIGN AND METHODS- A prospective...... (managed by the patient) and severe (requiring assistance from others) hypoglycemia. RESULTS- Forty-nine (45%) women experienced 178 severe hypoglycemic events, corresponding to 5.3, 2.4, and 0.5 events/patient-year in the first, second, and third trimesters, respectively. The incidence of mild...... hypoglycemia. A1C, median SMPG, and fluctuations in SMPG decreased during pregnancy, with no differences between women with and without severe hypoglycemia. Logistic regression analysis identified history of severe hypoglycemia the year preceding pregnancy (odds ratio 3.3 [95% CI 1.2-9.2]) and impaired...

  12. Suboptimal metabolic control and decompensation in children and adolescents with diabetes mellitus type 1

    Directory of Open Access Journals (Sweden)

    N. Ya. Filina

    2016-01-01

    Full Text Available Aim of the study is identifying the causes of decompensation of metabolism in children with different levels of HbA1c by studying daily glycemic profiles using a continuous monitoring system (CGMS, Medtronic MiniMed, USA.Materials and methods. Blood glucose of 207 type 1 diabetes children with different compensation level was researched by continuous glucose monitoring system (СGMS. Statistical processing of the results was carried out using XLSTATS 4.0 program.Results. The causes of diabetes suboptimal control were deficit of bolus insulin doses in 53%, «dawn phenomenon» in 23%, hidden night hypoglycemia in 26%. Patients with HbA1c level higher than 9% have deficit short acting and basal insulin that was the cause of bad metabolic control. The compare of selfcontrol results and CGMS data was preformed and pointed the importance of glucose monitoring system for decompensation causes identification.

  13. Zinc Status Biomarkers and Cardiometabolic Risk Factors in Metabolic Syndrome: A Case Control Study

    Science.gov (United States)

    Freitas, Erika P. S.; Cunha, Aline T. O.; Aquino, Sephora L. S.; Pedrosa, Lucia F. C.; Lima, Severina C. V. C.; Lima, Josivan G.; Almeida, Maria G.; Sena-Evangelista, Karine C. M.

    2017-01-01

    Metabolic syndrome (MS) involves pathophysiological alterations that might compromise zinc status. The aim of this study was to evaluate zinc status biomarkers and their associations with cardiometabolic factors in patients with MS. Our case control study included 88 patients with MS and 37 controls. We performed clinical and anthropometric assessments and obtained lipid, glycemic, and inflammatory profiles. We also evaluated zinc intake, plasma zinc, erythrocyte zinc, and 24-h urinary zinc excretion. The average zinc intake was significantly lower in the MS group (p 0.05) between the two groups. We found significantly higher erythrocyte zinc concentration in the MS group (p waist circumference (r = 0.253), triglyceride concentration (r = 0.360), glycated hemoglobin concentration (r = 0.250), homeostatic model assessment—insulin resistance (r = 0.223), and high-sensitivity C-reactive protein concentration (r = 0.427) (all p < 0.05) in the MS group. Patients with MS had alterations in zinc metabolism mainly characterized by an increase in erythrocyte zinc and higher zincuria. PMID:28241426

  14. Flux analysis and control of the central metabolic pathways in Escherichia coli.

    Science.gov (United States)

    Holms, H

    1996-12-01

    The growth of the bacterial cell involves the co-ordination of the fluxes of carbon into a considerable diversity of products that are the components of the cell. Fortunately the monomers from which the cell's polymers are made are themselves synthesised from a relatively small group of precursors that are the products of the central metabolic pathways. This simplification renders cell metabolism accessible to flux analysis, a method for handling experimental data to derive metabolic fluxes. Through such analysis of the growth of Escherichia coli ML308 on 11 single carbon sources in batch, turbidostat or chemostat culture general patterns are discernible. Most significant among these are that growth on different carbon sources is achieved without any obvious enzyme acting as a regulator of metabolic flux, except when acetate is the sole source of carbon. In this case a junction is created at which iso citrate dehydrogenase (ICDH) and isocitrate lyase (ICL) compete for their common substrate and this competition is resolved by partial inactivation of ICDH to match flux through ICL and this balance limits growth rate. In this sense, flux through ICDH and ICL is 'rate-limiting'. Uptake of six of the remaining carbon inputs exceeds the capacity of the central metabolic pathways (CMPs) to sustain flux to the precursors required for growth and the CMPs are balanced by excretion of acetate. Restriction of carbon uptake by chemostat progressively diminishes growth rate and acetate excretion until acetate excretion is prevented. For the four remaining carbon sources, uptake is apparently restricted and the products are biomass, carbon dioxide and water. Carbon sources feeding the phosphorylated parts of the CMPs flux relatively more carbon to precursors (Pre-C) than CO2 when compared with carbon sources which feed into the non-phosphorylated pathways. Pre-C/CO2 ratios for the former are 1.73-3.91 and for the latter are 0.46-0.78. Flux analysis of all 11 carbon sources shows

  15. Postpartum metabolic control in a cohort of women with type 1 diabetes.

    Science.gov (United States)

    Quirós, Carmen; Patrascioiu, Ioana; Perea, Verónica; Bellart, Jordi; Conget, Ignacio; Vinagre, Irene

    2015-03-01

    Pregnancy in women with type 1 diabetes (T1D) involves greater risks as compared to non-diabetic women, but less information is available about blood glucose and weight control after delivery. Our aim was to evaluate the postpartum metabolic profile (blood glucose and weight control) of women with T1D and the factors related to those metabolic outcomes. A retrospective, observational study of 36 women with T1D during pregnancy and for up to one year after delivery. Fifty percent of patients attended a preconceptional planning program (PPP), and 44.4% of women were treated with continuous subcutaneous insulin infusion. Mean preconceptional HbA1c and body mass index (BMI) were 7.2±1.2% and 23.8±5.0 respectively. In the total cohort, blood glucose control significantly worsened one year after delivery (HbA1c: 7.2±1.2 vs 7.6±1.2%, P<0.001). Lower preconceptional HbA1c values were found in patients who attended PPP (6.6±0.5 vs. 7.8±1.4%; P=0.02), and were maintained for one year after delivery. No differences were found in body mass index (BMI) from the pregestational period to one year after delivery in any of two groups (No PPP 22.5±4.6 vs 23.2±4.8, P=0.078; PPP 25.4±3.4 vs 25.5±3.4 kg/m(2), P=0.947). Preconceptional HbA1c was shown to be the most important determinant of metabolic control (β=0.962, p<0.001) and weight one year after delivery (β=0.524, p=0.025) and weight gain during pregnancy (β=0.633, p=0.004). Pregnant women with T1D return to prepregnancy body weight one year after delivery, especially those with lower HbA1c levels and BMI before pregnancy. However, blood glucose control deteriorates after delivery, suggesting the need for changes in clinical practice after delivery. Copyright © 2014 SEEN. Published by Elsevier España, S.L.U. All rights reserved.

  16. Petrogenesis of Mount Rainier andesite: magma flux and geologic controls on the contrasting differentiation styles at stratovolcanoes of the southern Washington Cascades

    Science.gov (United States)

    Sisson, Thomas W.; Salters, V.J.M.; Larson, P.B.

    2013-01-01

    Quaternary Mount Rainier (Washington, USA) of the Cascades magmatic arc consists of porphyritic calc-alkaline andesites and subordinate dacites, with common evidence for mingling and mixing with less evolved magmas encompassing andesites, basaltic andesites, and rarely, basalts. Basaltic andesites and amphibole andesites (spessartites) that erupted from vents at the north foot of the volcano represent some of Mount Rainier's immediate parents and overlap in composition with regional basalts and basaltic andesites. Geochemical (major and trace elements) and isotopic (Sr, Nd, Pb, O) compositions of Mount Rainier andesites and dacites are consistent with modest assimilation (typically ≤20 wt%) of evolved sediment or sediment partial melt. Sandstones and shales of the Eocene Puget Group, derived from the continental interior, are exposed in regional anticlines flanking the volcano, and probably underlie it in the middle to lower crust, accounting for their assimilation. Mesozoic and Cenozoic igneous basement rocks are unsuitable as assimilants due to their high 143Nd/144Nd, diverse206Pb/204Pb, and generally high δ18O.

  17. Metabolic markers or conditions preceding Parkinson's disease: a case-control study.

    Science.gov (United States)

    Savica, Rodolfo; Grossardt, Brandon R; Ahlskog, J Eric; Rocca, Walter A

    2012-07-01

    Several metabolic markers or conditions have been explored as possible risk or protective factors for Parkinson's disease (PD); however, results remain conflicting. We further investigated these associations using a case-control study design. We used the medical records-linkage system of the Rochester Epidemiology Project to identify 196 subjects who developed PD in Olmsted County, Minnesota, from 1976 through 1995. Each incident case was matched by age (±1 year) and sex to a general population control. We reviewed the complete medical records of cases and controls in the medical records-linkage system to abstract information about body mass index (BMI), cholesterol level, hypertension, and diabetes mellitus preceding the onset of PD (or the index year). There were no significant differences between cases and controls for the metabolic markers or conditions investigated. No significant associations were found using 2 cutoffs for BMI level (BMI ≥ 25 or BMI ≥ 30 kg/m(2) ) and 3 cutoffs for cholesterol levels (>200, >250, or >300 mg/dL). Neither a diagnosis of hypertension or the documented use of antihypertensive medications was significantly associated with the subsequent risk of PD (odds ratio [OR], 1.00; 95% confidence interval [CI], 0.65-1.54; P = .99) nor was a diagnosis of diabetes mellitus or the use of glucose-lowering medications (OR, 0.77; 95% CI, 0.37-1.57; P = .47). Our study, based on historical information from a records-linkage system, does not support an association between BMI, cholesterol level, hypertension, or diabetes mellitus with later development of PD.

  18. Filed Oriented Direct Feedback Control of Cascaded Brushless Doubly-fed Machine%级联无刷双馈电机的磁场定向直接反馈控制

    Institute of Scientific and Technical Information of China (English)

    王乐英; 夏超英

    2011-01-01

    By deducing the mathematical model of cascade brushless doubly-fed machine(CBDFM) in rotor coordinate,the model in control machine synchronous coordinate was derived.Based on analysis to this model,it could be concluded that the machine's torque and control machine's flux could be controlled effectively by the cross and direct axis component of the control machine's stator current.According to this conclusion,the CBDFM control method was then designed.With outer-loop as flux and torque loop,inner-loop as current loop,the control of total torque and control machine's flux amplitude was then realized.In the meantime,this control algorithm was simple and avoided solving complex nonlinear equation.At last,simulation results proved the effect of this method.%根据级联无刷双馈电机(cascade brushless doubly-fedmachine,CBDFM)转子坐标系下的数学模型,推导得到了它在控制电机同步坐标系下的数学模型,通过对该模型的分析,得出控制电机定子电流的交、直轴分量分别可以实现对电机转矩和控制电机磁链进行有效控制的结论。根据该结论,设计了CBDFM的控制方法,其外环为磁链和转矩环,内环为电流环,实现对控制电机磁链幅值和电机转矩的控制,回避了求解复杂非线性方程的困难,控制算法简单。仿真实验结果证明了该方法的有效性。

  19. Cascade Mountain Range in Oregon

    Science.gov (United States)

    Sherrod, David R.

    2016-01-01

    The Cascade mountain system extends from northern California to central British Columbia. In Oregon, it comprises the Cascade Range, which is 260 miles long and, at greatest breadth, 90 miles wide (fig. 1). Oregon’s Cascade Range covers roughly 17,000 square miles, or about 17 percent of the state, an area larger than each of the smallest nine of the fifty United States. The range is bounded on the east by U.S. Highways 97 and 197. On the west it reaches nearly to Interstate 5, forming the eastern margin of the Willamette Valley and, farther south, abutting the Coast Ranges. 

  20. Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: a randomized-controlled clinical trial.

    Science.gov (United States)

    Dehghan, Parvin; Gargari, Bahram Pourghassem; Jafar-Abadi, Mohammad Asghari; Aliasgharzadeh, Akbar

    2014-02-01

    There is limited evidence on the effects of prebiotics on inflammation. Therefore, the aim of this study was to evaluate the effects of inulin supplementation on inflammatory indices and metabolic endotoxemia in patients with type 2 diabetes mellitus. The participants included diabetic females (n = 49). They were divided into an intervention group (n = 24) as well as a control group (n = 25) and received 10 g/d inulin or maltodextrin for 8 weeks, respectively. Fasting blood sugar (FBS), HbA1c, insulin, high-sensitive C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10), and plasma lipopolysaccharide (LPS) were measured pre and post intervention. Inulin-supplemented patients exhibited a significant decrease in FBS (8.5%), HbA1c (10.4%), fasting insulin (34.3%), homeostasis model assessment of insulin resistance (HOMA-IR) (39.5%), hs-CRP (35.6%), TNF-α (23.1%), and LPS (27.9%) compared with the maltodextrin group (p inulin compared with the maltodextrin group. It can be concluded that inulin supplementation seems to be able to modulate inflammation and metabolic endotoxemia in women with type 2 diabetes.

  1. Research on Mechanical Characteristics of AC Motor with Cascade DC Chopper Speed Control System%斩波串级调速系统电机机械特性曲线的研究

    Institute of Scientific and Technical Information of China (English)

    王归新; 裴合伟; 晓琼; 鲜万春

    2012-01-01

    In high power application, wound AC motor rotor loop cascade control system has very good speed performance and energy-saving effect. Based on the analysis that the equivalent internal impedance of three-phase rectifier bridge influence rectifier output,rectifier bridge and follow-up circuit equivalent to the mo-tor rotor loop resistance, inferred to the mechanical characteristics in the cascade control system.Came to con-clusion that two influence factors for mechanical characteristics. The rotor loop equivalent impedance is more serious than rotor leakage reactance effect commutation overlap angle to mechanical characteristics influence. The simulation and the experiment verify the theory.%绕线转子式交流电机转子回路串级调速系统具有很好的调速性能和节电效果,在中大功率领域应用较多.基于对三相整流电路电源等效内阻抗对桥路整流输出的影响分析,将整流桥及其后续电路等效为电机转子回路的电阻,推导出在有串级调速系统下电机的机械特性,得出了影响电机机械特性的两方面因素,其中转子回路的等效阻抗对机械特性的影响相对于转子漏抗影响换相重叠角对机械特性的影响尤为严重的结论.仿真结果证实了理论推导的结论,并进行了实验验证.

  2. Simulation Analysis of Control Method in Cascade H-Bridge Static Synchronous Compensator%级联H桥型静止同步补偿器控制方法仿真分析

    Institute of Scientific and Technical Information of China (English)

    姜建国; 滕达; 林川

    2011-01-01

    无功功率的传输对电力系统稳定性与安全性会产生不利的影响,传统的无功补偿技术已经不能满足要求.为提高无功补偿性能,在分析级联H桥型静止同步补偿器(STATCOM)的工作原理和拓扑结构的基础上,采用跟踪型脉宽调制(PWM)控制技术的电流直接控制方法,研究了级联H桥型STATCOM的稳态和动态的无功补偿作用.通过MATLAB仿真软件分析,仿真结果验证了控制方法的有效性和级联H桥型STATCOM的无功补偿性能.%The transmission of reactive power has negative impacts on stability and security of power system, and traditional reactive power compensation technologies are difficult to meet system requirements. In order to improve the performance of reactive power compensation,the principle and topology of H-Bridge STATCOM were studied. The direct current control method of tracking PWM was used to study the steady state and dynamic state reactive power compensation performance of cascade H-bridge STATCOM. MATLAB simulation results prove the validity of the control method and the performance of cascade H-bridge STATCOM for reactive power compensation.

  3. Distinct metabolic network states manifest in the gene expression profiles of pediatric inflammatory bowel disease patients and controls

    Science.gov (United States)

    Knecht, Carolin; Fretter, Christoph; Rosenstiel, Philip; Krawczak, Michael; Hütt, Marc-Thorsten

    2016-09-01

    Information on biological networks can greatly facilitate the function-orientated interpretation of high-throughput molecular data. Genome-wide metabolic network models of human cells, in particular, can be employed to contextualize gene expression profiles of patients with the goal of both, a better understanding of individual etiologies and an educated reclassification of (clinically defined) phenotypes. We analyzed publicly available expression profiles of intestinal tissues from treatment-naive pediatric inflammatory bowel disease (IBD) patients and age-matched control individuals, using a reaction-centric metabolic network derived from the Recon2 model. By way of defining a measure of ‘coherence’, we quantified how well individual patterns of expression changes matched the metabolic network. We observed a bimodal distribution of metabolic network coherence in both patients and controls, albeit at notably different mixture probabilities. Multidimensional scaling analysis revealed a bisectional pattern as well that overlapped widely with the metabolic network-based results. Expression differences driving the observed bimodality were related to cellular transport of thiamine and bile acid metabolism, thereby highlighting the crosstalk between metabolism and other vital pathways. We demonstrated how classical data mining and network analysis can jointly identify biologically meaningful patterns in gene expression data.

  4. Errors associated with metabolic control analysis. Application Of Monte-Carlo simulation of experimental data.

    Science.gov (United States)

    Ainscow, E K; Brand, M D

    1998-09-21

    The errors associated with experimental application of metabolic control analysis are difficult to assess. In this paper, we give examples where Monte-Carlo simulations of published experimental data are used in error analysis. Data was simulated according to the mean and error obtained from experimental measurements and the simulated data was used to calculate control coefficients. Repeating the simulation 500 times allowed an estimate to be made of the error implicit in the calculated control coefficients. In the first example, state 4 respiration of isolated mitochondria, Monte-Carlo simulations based on the system elasticities were performed. The simulations gave error estimates similar to the values reported within the original paper and those derived from a sensitivity analysis of the elasticities. This demonstrated the validity of the method. In the second example, state 3 respiration of isolated mitochondria, Monte-Carlo simulations were based on measurements of intermediates and fluxes. A key feature of this simulation was that the distribution of the simulated control coefficients did not follow a normal distribution, despite simulation of the original data being based on normal distributions. Consequently, the error calculated using simulation was greater and more realistic than the error calculated directly by averaging the original results. The Monte-Carlo simulations are also demonstrated to be useful in experimental design. The individual data points that should be repeated in order to reduce the error in the control coefficients can be highlighted.

  5. Diet quality in obese/overweight individuals with/without metabolic syndrome compared to normal weight controls

    OpenAIRE

    Yosaee, Somaye; Esteghamati, Alireza; Nazari Nasab, Mahdiyeh; Khosravi, Ahmad; Alinavaz, Mina; Hosseini, Banafshe; Djafarian, Kurosh

    2016-01-01

    Background: Metabolic syndrome (MetS) is a serious public health concern worldwide; however, the pathogenesis of this disease has not been yet cleared. This study aimed to compare diet quality in obese/overweight participants with/without metabolic syndrome with normal weight controls. Methods: This was a comparative study on 147 Iranian adults under treatment at the Endocrinology Center of Tehran University of Medical Sciences. They were assigned into three groups (normal weight, obese weigh...

  6. Reduced metabolism in brain "control networks" following cocaine-cues exposure in female cocaine abusers.

    Directory of Open Access Journals (Sweden)

    Nora D Volkow

    Full Text Available OBJECTIVE: Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved. METHOD: To test this we compared brain metabolism (using PET and ¹⁸FDG between female (n = 10 and male (n = 16 active cocaine abusers when they watched a neutral video (nature scenes versus a cocaine-cues video. RESULTS: Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05; females significantly decreased metabolism (-8.6%±10 whereas males tended to increase it (+5.5%±18. SPM analysis (Cocaine-cues vs Neutral in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001 whereas males showed increases in right inferior frontal gyrus (BA 44/45 (only at p<0.005. The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001 in frontal (BA 8, 9, 10, anterior cingulate (BA 24, 32, posterior cingulate (BA 23, 31, inferior parietal (BA 40 and thalamus (dorsomedial nucleus. CONCLUSIONS: Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from "control networks" (prefrontal, cingulate, inferior parietal, thalamus in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition. This highlights the importance of gender tailored interventions for cocaine addiction.

  7. Patterns of top-down control in a seagrass ecosystem: could a roving apex predator induce a behaviour-mediated trophic cascade?

    Science.gov (United States)

    Burkholder, Derek A; Heithaus, Michael R; Fourqurean, James W; Wirsing, Aaron; Dill, Lawrence M

    2013-11-01

    1. The loss of large-bodied herbivores and/or top predators has been associated with large-scale changes in ecosystems around the world, but there remain important questions regarding the contexts in which such changes are most likely and the mechanisms through which they occur, particularly in marine ecosystems. 2. We used long-term exclusion cages to examine the effects of large grazers (sea cows, Dugong dugon; sea turtles Chelonia mydas) on seagrass community structure, biomass and nutrient dynamics. Experiments were conducted in habitats with high risk of predation (interior of shallow banks) and lower risk (edges of banks) to elucidate whether nonconsumptive (risk) effects of tiger sharks (Galeocerdo cuvier), a roving predator, structure herbivore impacts on seagrasses. 3. In lower-risk habitats, excluding large herbivores resulted in increased leaf length for Cymodocea angustata and Halodule uninervis. C. angustata shoot densities nearly tripled when released from herbivory, while H. uninervis nearly disappeared from exclusion cages over the course of the study. 4. We found no support for the hypothesis that grazing increases seagrass nutrient content. Instead, phosphorus content was higher in seagrasses within exclosures. This pattern is consistent with decreased light availability in the denser C. angustata canopies that formed in exclosures, and may indicate that competition for light led to the decrease in H. uninervis. 5. Impacts of large grazers were consistent with a behaviour-mediated trophic cascade (BMTC) initiated by tiger sharks and mediated by risk-sensitive foraging by large grazers. 6, Our results suggest that large-bodied grazers likely played important roles in seagrass ecosystem dynamics historically and that roving predators are capable of initiating a BMTC. Conservation efforts in coastal ecosystems must account for such interactions or risk unintended consequences.

  8. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin.

    Science.gov (United States)

    do Carmo, Jussara M; da Silva, Alexandre A; Romero, Damian G; Hall, John E

    2017-06-01

    Interactions of hypothalamic signaling pathways that control body temperature (BT), blood pressure (BP), and energy balance are poorly understood. We investigated whether the chronic BP and metabolic actions of leptin are differentially modulated by changes in ambient temperature (TA ). Mean arterial pressure (MAP), heart rate (HR), BT, motor activity (MA), and oxygen consumption (Vo2) were measured 24 h/d at normal laboratory TA (23°C), at thermoneutral zone (TNZ, 30°C) for mice or during cold exposure (15°C) in male wild-type mice. After control measurements, leptin (4 μg/kg/min) or saline vehicle was infused for 7 d. At TNZ, leptin reduced food intake (-11.0 ± 0.5 g cumulative deficit) and body weight by 6% but caused no changes in MAP or HR. At 15°C, leptin infusion did not alter food intake but increased MAP and HR (8 ± 1 mmHg and 33 ± 7 bpm), while Vo2 increased by ∼10%. Leptin reduced plasma glucose and insulin levels at 15°C but not at 30°C. These results demonstrate that the chronic anorexic effects of leptin are enhanced at TNZ, while its effects on insulin and glucose levels are attenuated and its effects on BP and HR are abolished. Conversely, cold TA caused resistance to leptin's anorexic effects but amplified its effects to raise BP and reduce insulin and glucose levels. Thus, the brain circuits by which leptin regulates food intake and cardiovascular function are differentially influenced by changes in TA -Do Carmo, J. M., da Silva, A. A., Romero, D. G., Hall, J. E. Changes in ambient temperature elicit divergent control of metabolic and cardiovascular actions by leptin. © FASEB.

  9. Impact of probiotics in women with gestational diabetes mellitus on metabolic health: a randomized controlled trial.

    Science.gov (United States)

    Lindsay, Karen L; Brennan, Lorraine; Kennelly, Maria A; Maguire, Orla C; Smith, Thomas; Curran, Sinead; Coffey, Mary; Foley, Michael E; Hatunic, Mensud; Shanahan, Fergus; McAuliffe, Fionnuala M

    2015-04-01

    Probiotics are live microorganisms that may confer health benefits on the host. Recent trials of probiotic use among healthy pregnant women demonstrate potential for improved glycemic control. The aim of this study was to investigate the effects of a probiotic capsule intervention on maternal metabolic parameters and pregnancy outcome among women with gestational diabetes. This double-blind placebo-controlled randomized trial recruited pregnant women with a new diagnosis of gestational diabetes or impaired glucose tolerance following a 3-hour 100-g glucose tolerance test. Women were randomized to a daily probiotic (Lactobacillus salivarius UCC118) or placebo capsule from diagnosis until delivery. Fasting blood samples were collected at baseline and 4-6 weeks after capsule commencement for analysis of glucose, insulin, c-peptide, and lipids. The primary outcome was difference in fasting glucose postintervention, first analyzed on an intention-to-treat basis and followed by per-protocol analysis that excluded women commenced on pharmacological therapy (insulin or metformin). Secondary outcomes were changes in insulin, c-peptide, homeostasis model assessment and lipids, requirement for pharmacological therapy, and neonatal anthropometry. Of 149 women recruited and randomized, there were no differences between the probiotic and placebo groups in postintervention fasting glucose (4.65 ± 0.49 vs 4.65 ± 0.53 mmol/L; P = 373), requirement for pharmacological therapy (17% vs 14%; P = .643), or birthweight (3.57 ± 0.64 vs 3.60 ± 0.57 kg; P = .845). Among 100 women managed with diet and exercise alone, fasting plasma glucose decreased significantly within both the probiotic (4.76 ± 0.45 to 4.57 ± 0.42 mmol/L; P metabolic parameters or pregnancy outcome. A probiotic capsule intervention among women with abnormal glucose tolerance had no impact on glycemic control. The observed attenuation of the normal pregnancy-induced rise in total and LDL cholesterol following

  10. Are longer cascades more stable?

    OpenAIRE

    2004-01-01

    Yes, they are. We consider data from experimental cascade games that were run in different laboratories, and find uniformly that subjects are more willing to follow the crowd, the bigger the crowd is �although the decision makers who are added to the crowd should in theory simply follow suit and hence reveal no information. This correlation of length and strength of cascades appears consistently across games with different parameters and different choice sets for the subjects. ...

  11. Cascading Gravity is Ghost Free

    CERN Document Server

    de Rham, Claudia; Tolley, Andrew J

    2010-01-01

    We perform a full perturbative stability analysis of the 6D cascading gravity model in the presence of 3-brane tension. We demonstrate that for sufficiently large tension on the (flat) 3-brane, there are no ghosts at the perturbative level, consistent with results that had previously only been obtained in a specific 5D decoupling limit. These results establish the cascading gravity framework as a consistent infrared modification of gravity.

  12. Aeroelasticity in Turbomachine-Cascades.

    Science.gov (United States)

    1982-11-10

    STABLE -180 UNSTABLE -360 ’ - ’ - -180 0. 󈧖O DIAGRAM 3 AERODYNAMIC LIFT (OENT)COEFFICIENTI AND PHASE LEADS IN DEPENDANCE OF FLOM GUANTATIES AND CASCADE...ABL -0.8 0.0 -5 0. -5 DIAGRAM ’. AERODYNAMIC NORK AND DAMPING COEFFICIENTS (FOR A RIGID NOTION) IN DEPENDANCE OF FLOW OURNTATIES AND CASCADE GEOMETRY...coefficients on blades + blade vibration + vizualization in the transonic flow domain (Schlieren) + instability dependance on flow conditions, blade

  13. Low Noise Interband Cascade Photodetectors

    Science.gov (United States)

    2012-02-28

    National Laboratories, Zhaobing Tian, Zhihua Cai, R. T. Hinkey, L. Li, Tetsuya D. Mishima , Michael B. Santos, and Matthew B. Johnson at the...Phys. 107, No. 5, 054514 (2010). 2. R. Q. Yang, Z. Tian, J. F. Klem, T. D. Mishima , M. B. Santos, and M. B. Johnson, “Interband cascade photovoltaic...2012). 4. Z. Tian, Z. Cai, R. Q. Yang, T. D. Mishima , M. B. Santos, M. B. Johnson, and J. F. Klem, “Interband Cascade Infrared Photodetectors

  14. Cascade Product of Permutation Groups

    OpenAIRE

    Egri-Nagy, Attila; Nehaniv, Chrystopher L.

    2013-01-01

    We define the cascade product of permutation groups as an external product, an explicit construction of substructures of the iterated wreath product that are much smaller than the full wreath product. This construction is essential for computational implementations of algebraic hierarchical decompositions of finite automata. We show how direct, semidirect, and wreath products and group extensions can all be expressed as cascade products, and analyse examples of groups that can be constructed ...

  15. Basal metabolic rate in carnivores is associated with diet after controlling for phylogeny.

    Science.gov (United States)

    Munoz-Garcia, Agusti; Williams, Joseph B

    2005-01-01

    Studies of basal metabolic rate (BMR), the minimum metabolic rate of postabsorptive, inactive endotherms while in their rest phase and thermal neutral zone, have contributed significantly to our understanding of animal energetics. Besides body mass, the main determinant of BMR, researchers have invoked diet and phylogenetic history as important factors that influence BMR, although their relative importance has been controversial. For 58 species within the Carnivora, we tested the hypothesis that BMR is correlated with home range size, a proxy for level of activity, and diet, using conventional least squares regression (CLSR) and regression based on phylogenetic independent contrasts (PIC). Results showed that BMR of Carnivora was positively correlated with home range size after controlling for body mass, regardless of the statistical method employed. We also found that diet and mass-adjusted home range size were correlated. When we simultaneously tested the effect of diet and mass-adjusted home range on mass-adjusted BMR, home range size was insignificant because of its colinearity with diet. Then we eliminated home range size from our model, and diet proved to be significant with both CLSR and PIC. We concluded that species that eat meat have larger home ranges and higher BMR than species that eat vegetable matter. To advance our understanding of the potential mechanisms that might explain our results, we propose the "muscle performance hypothesis," which suggests that selection for different muscle fiber types can account for the differences in BMR observed between meat eaters and vegetarian species within the Carnivora.

  16. Proteomics-Based Metabolic Modeling Reveals That Fatty Acid Oxidation (FAO) Controls Endothelial Cell (EC) Permeability*

    Science.gov (United States)

    Patella, Francesca; Schug, Zachary T.; Persi, Erez; Neilson, Lisa J.; Erami, Zahra; Avanzato, Daniele; Maione, Federica; Hernandez-Fernaud, Juan R.; Mackay, Gillian; Zheng, Liang; Reid, Steven; Frezza, Christian; Giraudo, Enrico; Fiorio Pla, Alessandra; Anderson, Kurt; Ruppin, Eytan; Gottlieb, Eyal; Zanivan, Sara

    2015-01-01

    Endothelial cells (ECs) play a key role to maintain the functionality of blood vessels. Altered EC permeability causes severe impairment in vessel stability and is a hallmark of pathologies such as cancer and thrombosis. Integrating label-free quantitative proteomics data into genome-wide metabolic modeling, we built up a model that predicts the metabolic fluxes in ECs when cultured on a tridimensional matrix and organize into a vascular-like network. We discovered how fatty acid oxidation increases when ECs are assembled into a fully formed network that can be disrupted by inhibiting CPT1A, the fatty acid oxidation rate-limiting enzyme. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which are restored by replenishing the tricarboxylic acid cycle. Remarkably, global phosphoproteomic changes measured upon acute CPT1A inhibition pinpointed altered calcium signaling. Indeed, CPT1A inhibition increases intracellular calcium oscillations. Finally, inhibiting CPT1A induces hyperpermeability in vitro and leakage of blood vessel in vivo, which were restored blocking calcium influx or replenishing the tricarboxylic acid cycle. Fatty acid oxidation emerges as central regulator of endothelial functions and blood vessel stability and druggable pathway to control pathological vascular permeability. PMID:25573745

  17. Diet liberalization and metabolic control in type I diabetic outpatients treated by continuous subcutaneous insulin infusion.

    Science.gov (United States)

    Chantelau, E; Sonnenberg, G E; Stanitzek-Schmidt, I; Best, F; Altenähr, H; Berger, M

    1982-01-01

    In 10 type I diabetic outpatients treated by continuous subcutaneous insulin infusion (CSII), dietary habits and metabolic control were investigated. Under conditions of a conventional diabetes diet (including 5-6 meals per day and a strictly planned meal intake) as well as under a "less restricted diabetes diet" (e.g., free choice of number, timing, and amount of carbohydrate intake) near normoglycemia could be achieved. Mean daily blood glucose levels did not change significantly when the patients' nutrition was alternated between both diets. During the "less restricted diabetes diet," the patients opted for a rather high fat intake (51 +/- 5% fat, 34 +/- 5% carbohydrate, and 15 +/- 2% protein). Despite this unintended dietary behavior, serum lipids and body weight remained normal after an observation period of 4-6 mo. It is concluded that during permanent near normoglycemia achieved by CSII a partial liberalization of the diabetes diet does not introduce any short-term or long-term metabolic risk factors for cardiovascular diseases.

  18. Proteomics-based metabolic modeling reveals that fatty acid oxidation (FAO) controls endothelial cell (EC) permeability.

    Science.gov (United States)

    Patella, Francesca; Schug, Zachary T; Persi, Erez; Neilson, Lisa J; Erami, Zahra; Avanzato, Daniele; Maione, Federica; Hernandez-Fernaud, Juan R; Mackay, Gillian; Zheng, Liang; Reid, Steven; Frezza, Christian; Giraudo, Enrico; Fiorio Pla, Alessandra; Anderson, Kurt; Ruppin, Eytan; Gottlieb, Eyal; Zanivan, Sara

    2015-03-01

    Endothelial cells (ECs) play a key role to maintain the functionality of blood vessels. Altered EC permeability causes severe impairment in vessel stability and is a hallmark of pathologies such as cancer and thrombosis. Integrating label-free quantitative proteomics data into genome-wide metabolic modeling, we built up a model that predicts the metabolic fluxes in ECs when cultured on a tridimensional matrix and organize into a vascular-like network. We discovered how fatty acid oxidation increases when ECs are assembled into a fully formed network that can be disrupted by inhibiting CPT1A, the fatty acid oxidation rate-limiting enzyme. Acute CPT1A inhibition reduces cellular ATP levels and oxygen consumption, which are restored by replenishing the tricarboxylic acid cycle. Remarkably, global phosphoproteomic changes measured upon acute CPT1A inhibition pinpointed altered calcium signaling. Indeed, CPT1A inhibition increases intracellular calcium oscillations. Finally, inhibiting CPT1A induces hyperpermeability in vitro and leakage of blood vessel in vivo, which were restored blocking calcium influx or replenishing the tricarboxylic acid cycle. Fatty acid oxidation emerges as central regulator of endothelial functions and blood vessel stability and druggable pathway to control pathological vascular permeability.

  19. Protocol for quality control in metabolic profiling of biological fluids by U(H)PLC-MS.

    Science.gov (United States)

    Gika, Helen G; Zisi, Chrysostomi; Theodoridis, Georgios; Wilson, Ian D

    2016-01-01

    The process of untargeted metabolic profiling/phenotyping of complex biological matrices, i.e., biological fluids such as blood plasma/serum, saliva, bile, and tissue extracts, provides the analyst with a wide range of challenges. Not the least of these challenges is demonstrating that the acquired data are of "good" quality and provide the basis for more detailed multivariate, and other, statistical analysis necessary to detect, and identify, potential biomarkers that might provide insight into the process under study. Here straightforward and pragmatic "quality control (QC)" procedures are described that allow investigators to monitor the analytical processes employed for global, untargeted, metabolic profiling. The use of this methodology is illustrated with an example from the analysis of human urine where an excel spreadsheet of the preprocessed LC-MS output is provided with embedded macros, calculations and visualization plots that can be used to explore the data. Whilst the use of these procedures is exemplified on human urine samples, this protocol is generally applicable to metabonomic/metabolomic profiling of biofluids, tissue and cell extracts from many sources. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Interband Cascade Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui Q. [Univ. of Oklahoma, Norman, OK (United States); Santos, Michael B. [Univ. of Oklahoma, Norman, OK (United States); Johnson, Matthew B. [Univ. of Oklahoma, Norman, OK (United States)

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  1. A Novel DC-Link Voltages Balancing Control Method for Cascaded H-Bridge Rectifier%一种H桥级联型PWM整流器的直流母线电压平衡控制新方法

    Institute of Scientific and Technical Information of China (English)

    陶兴华; 李永东; 孙敏

    2011-01-01

    直流电压平衡是H桥级联型整流器(CHBR)控制的主要问题。针对此本文提出了一种电压平衡控制新方法。文中推导了整流器的调制比增量与输出电压之间的关系式。在此基础上,通过反馈的直流电压重新配置调制比,以调节各路直流电压,使之达到平衡。文中讨论了在算法实现中遇到的问题,并给出了解决措施,得到一种较好的控制算法。对所提的方法进行了仿真与实验研究。结果表明,该方法适用于多级级联的CHBR拓扑,能够实现对输入电流以及各级输出电压平衡的控制。%DC-link voltages balancing is very important for cascaded H-bridge rectifier(CHBR).A new control method for voltages balancing is proposed in this paper.The relationship between the modulation index increment and the output voltage error is deduced.Therefore the modulation indexes of the cells are rearranged according to the measured dc voltages and the DC voltages are regulated to be the same value.The implement method for the proposed strategy is discussed in detail and the final method is derived.Simulations and experiments were carried out with the presented method.All of them approve that the proposed method is effective for such cascaded topology.The good performance is achieved when the CHBR is operating on the different conditions.

  2. [Metabolism-related risk factors of cholelithiasis among Beijing residents: a case-control study].

    Science.gov (United States)

    Gu, Ying-Chao; He, Xiao-Dong; Yu, Jian-Chun; Kang, Wei-Ming; Tao, Lian-Yuan; Wu, Qiao

    2012-02-01

    To explore the metabolism-related risk factors of cholelithiasis among residents in Beijing. The clinical data including previous disease history, findings of physical examination, and results of cholecystosonography of 2270 patients with cholelithiasis identified in the Health Screening Center of Peking Union Medical College Hospital between August 2007 and August 2010 were retrospectively reviewed (the case group). Meanwhile, 4336 healthy individuals during the same period were randomly chosen as the control group. Total cholesterol, triglyceride, low-density lipoprotein cholesterol, fasting blood glucose, body mass index, and systolic blood pressure were positively correlated with the incidence of cholelithiasis (P cholelithiasis (P > 0.05). Cholelithiasis is resulted from multiple factors including elevated blood lipids, blood glucose, and systolic blood pressure among residents in Beijing.

  3. Metabolic control in patients with type 1 diabetes mellitus at the onset of primary adrenal insufficiency

    Directory of Open Access Journals (Sweden)

    A A Larina

    2013-06-01

    Full Text Available Primary adrenal insufficiency is a rare disorder but it is more common in patients with type 1 diabetes mellitus (T1DM or autoimmune thyroid diseases than in the general population. T1DM may precede the development of adrenocortical insufficiency. Addison’s disease can influence the glycemic control in patients with T1DM worsening glucose metabolism. It causes the decrease of gluconeogenesis, reduction in total insulin requirement and rather often «unexplained» recurrent hypoglycemia. Glucocorticoid replacement therapy in patients with primary adrenal insufficiency and T1DM increases the insulin requirement. The article presents the development of primary adrenal insufficiency in a patient with type 1 DM and autoimmune hypothyroidism, accompanied with incidents of recurrent hypoglycemia.

  4. Microbiological changes after periodontal therapy in diabetic patients with inadequate metabolic control

    Directory of Open Access Journals (Sweden)

    Carina Maciel Silva-Boghossian

    2014-05-01

    Full Text Available The present study investigated the effect of non-surgical periodontal treatment (SRP on the composition of the subgingival microbiota of chronic periodontitis (CP in individuals with type 2 diabetes (DM2 with inadequate metabolic control and in systemically healthy (SH individuals. Forty individuals (20 DM2 and 20 SH with CP underwent full-mouth periodontal examination. Subgingival plaque was sampled from 4 deep sites of each individual and tested for mean prevalence and counts of 45 bacterial taxa by the checkerboard method. Clinical and microbiological assessments were performed before and 3 months after SRP. At baseline, those in the DM2 group presented a significantly higher percentage of sites with visible plaque and bleeding on probing compared with those in the SH group (p < 0.01. Those in the DM2 group presented significantly higher levels of C. rectus and P. gingivalis, and lower prevalence of P. micra and S. anginosus, compared with those in the SH group (p ≤ 0.001. At the 3-month visit, both groups showed a significant improvement in all clinical parameters (p < 0.01. Those in the DM2 group showed significantly higher prevalence and/or levels of A. gerencseriae, A. naeslundii I, A. oris, A. odontolyticus, C. sputigena, F. periodonticum, and G. morbillorum compared with those in the SH group (p ≤ 0.001. However, those in the DM2 group showed a significant reduction in the levels of P. intermedia, P. gingivalis, T. forsythia, and T. denticola (p ≤ 0.001 over time. Those in the SRP group showed improved periodontal status and reduced levels of putative periodontal pathogens at 3 months’ evaluation compared with those in the DM2 group with inadequate metabolic control.

  5. [Impact of physical activity on metabolic control and the development of chronic complications in patients with type 1 diabetes mellitus].

    Science.gov (United States)

    Carral San Laureano, Florentino; Gutiérrez Manzanedo, José Vicente; Ayala Ortega, Carmen; García Calzado, Concepción; Silva Rodríguez, Juan José; Aguilar Diosdado, Manuel

    2010-01-01

    Together with a balanced diet, regular physical activity is one of the pillars of diabetes mellitus (DM) management. Physical activity theoretically provides the same advantages in people with DM as in the general population and also has some beneficial effects in controlling metabolic factors, such as improving blood glucose levels and insulin sensitivity. In this article, we analyze the main clinical studies published to date that evaluate the impact of physical activity on metabolic control or the development of chronic complications in patients with type 1 diabetes mellitus. In conclusion, most of the evaluated studies show that regular physical activity favorably affects metabolic control in DM (or at least does not have adverse effects). However, there is insufficient information about the impact of physical activity on the development and progression of chronic complications.

  6. Communication Scheme via Cascade Chaotic Systems

    Institute of Scientific and Technical Information of China (English)

    HUA Chang-Chun; GUAN Xin-Ping

    2004-01-01

    @@ A new chaotic communication scheme is constructed. Different from the existing literature, cascade chaotic systems are employed. Two cascade modes are considered. First, we investigate the input to state cascade mode;cascade systems between different kinds of chaotic systems are considered. Then the parameter cascade case of chaotic system is studied. Under the different cases, the corresponding receivers are designed, which can succeed in recovering the former emitted signal. Simulations are performed to verify the validity of the proposed main results.

  7. Acetylation control of cardiac fatty acid β-oxidation and energy metabolism in obesity, diabetes, and heart failure.

    Science.gov (United States)

    Fukushima, Arata; Lopaschuk, Gary D

    2016-12-01

    Alterations in cardiac energy metabolism are an important contributor to the cardiac pathology associated with obesity, diabetes, and heart failure. High rates of fatty acid β-oxidation with cardiac insulin resistance represent a cardiac metabolic hallmark of diabetes and obesity, while a marginal decrease in fatty acid oxidation and a prominent decrease in insulin-stimulated glucose oxidation are commonly seen in the early stages of heart failure. Alterations in post-translational control of energy metabolic processes have recently been identified as an important contributor to these metabolic changes. In particular, lysine acetylation of non-histone proteins, which controls a diverse family of mitochondrial metabolic pathways, contributes to the cardiac energy derangements seen in obesity, diabetes, and heart failure. Lysine acetylation is controlled both via acetyltransferases and deacetylases (sirtuins), as well as by non-enzymatic lysine acetylation due to increased acetyl CoA pool size or dysregulated nicotinamide adenine dinucleotide (NAD(+)) metabolism (which stimulates sirtuin activity). One of the important mitochondrial acetylation targets are the fatty acid β-oxidation enzymes, which contributes to alterations in cardiac substrate preference during the course of obesity, diabetes, and heart failure, and can ultimately lead to cardiac dysfunction in these disease states. This review will summarize the role of lysine acetylation and its regulatory control in the context of mitochondrial fatty acid β-oxidation. The functional contribution of cardiac protein lysine acetylation to the shift in cardiac energy substrate preference that occurs in obesity, diabetes, and especially in the early stages of heart failure will also be reviewed. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.

  8. Metabolic Syndrome Increases the Risk of Sudden Sensorineural Hearing Loss in Taiwan: A Case-Control Study.

    Science.gov (United States)

    Chien, Chen-Yu; Tai, Shu-Yu; Wang, Ling-Feng; Hsi, Edward; Chang, Ning-Chia; Wu, Ming-Tsang; Ho, Kuen-Yao

    2015-07-01

    Sudden sensorineural hearing loss has been reported to be associated with diabetes mellitus, hypertension, and hyperlipidemia in previous studies. The aim of this study was to examine whether metabolic syndrome increases the risk of sudden sensorineural hearing loss in Taiwan. A case-control study. Tertiary university hospital. We retrospectively investigated 181 cases of sudden sensorineural hearing loss and 181 controls from the Department of Otorhinolaryngology, Kaohsiung Medical University Hospital, in southern Taiwan from 2010 to 2012, comparing their clinical variables. We analyzed the relationship between metabolic syndrome and sudden sensorineural hearing loss. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III with Asian modifications. The demographic and clinical characteristics, audiometry results, and outcome were reviewed. Subjects with metabolic syndrome had a 3.54-fold increased risk (95% confidence interval [CI] = 2.00-6.43, P sudden sensorineural hearing loss compared with those without metabolic syndrome, after adjusting for age, sex, smoking, diabetes mellitus, hypertension, and hyperlipidemia. With increases in the number of metabolic syndrome components, the risk of sudden sensorineural hearing loss increased (P for trend hearing loss pattern may influence the outcome of sudden sensorineural hearing loss (P sudden sensorineural hearing loss in Taiwan. Vertigo and total hearing loss were indicators of a poor outcome in sudden sensorineural hearing loss. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  9. Cascade laser applications: trends and challenges

    Science.gov (United States)

    d'Humières, B.; Margoto, Éric; Fazilleau, Yves

    2016-03-01

    When analyses need rapid measurements, cost effective monitoring and miniaturization, tunable semiconductor lasers can be very good sources. Indeed, applications like on-field environmental gas analysis or in-line industrial process control are becoming available thanks to the advantage of tunable semiconductor lasers. Advances in cascade lasers (CL) are revolutionizing Mid-IR spectroscopy with two alternatives: interband cascade lasers (ICL) in the 3-6μm spectrum and quantum cascade lasers (QCL), with more power from 3 to 300μm. The market is getting mature with strong players for driving applications like industry, environment, life science or transports. CL are not the only Mid-IR laser source. In fact, a strong competition is now taking place with other technologies like: OPO, VCSEL, Solid State lasers, Gas, SC Infrared or fiber lasers. In other words, CL have to conquer a share of the Mid-IR application market. Our study is a market analysis of CL technologies and their applications. It shows that improvements of components performance, along with the progress of infrared laser spectroscopy will drive the CL market growth. We compare CL technologies with other Mid-IR sources and estimate their share in each application market.

  10. Prediction of Cascading Failures in Spatial Networks.

    Science.gov (United States)

    Shunkun, Yang; Jiaquan, Zhang; Dan, Lu

    2016-01-01

    Cascading overload failures are widely found in large-scale parallel systems and remain a major threat to system reliability; therefore, they are of great concern to maintainers and managers of different systems. Accurate cascading failure prediction can provide useful information to help control networks. However, for a large, gradually growing network with increasing complexity, it is often impractical to explore the behavior of a single node from the perspective of failure propagation. Fortunately, overload failures that propagate through a network exhibit certain spatial-temporal correlations, which allows the study of a group of nodes that share common spatial and temporal characteristics. Therefore, in this study, we seek to predict the failure rates of nodes in a given group using machine-learning methods. We simulated overload failure propagations in a weighted lattice network that start with a center attack and predicted the failure percentages of different groups of nodes that are separated by a given distance. The experimental results of a feedforward neural network (FNN), a recurrent neural network (RNN) and support vector regression (SVR) all show that these different models can accurately predict the similar behavior of nodes in a given group during cascading overload propagation.

  11. The Serum Antioxidant Status in Chinese Subjects with Metabolic Syndrome:a Case-Control Study

    Institute of Scientific and Technical Information of China (English)

    Yan-rong LI; Kun XUE; Hong-wei GUO; Min WU; Ming LIU

    2014-01-01

    Objective To investigate serum antioxidant status in subjects with metabolic syndrome (MS) and analyze the association between serum antioxidant status and MS components.MethodsA case-control study was conducted with 221 MS cases and 329 controls aged 18-70 years. Weight, height, body mass index, waist circumference, blood pressure, fasting blood glucose and lipids, as well as serum superoxide dismutase (SOD), glutathione peroxidase(GSH-Px), malondialdehyde (MDA), vitamin E,β-carotene and lycopene were examined.Results Mean serum SOD activity,β-carotene level were significantly lower, and MDA higher (P<0.05) in MS subjects than in controls after adjusting for age and gender. Serum SOD, GSH-Px andβ-carotene level were also decreased significantly (P<0.05) with increased number of MS components.Conclusion Serum antioxidant status was negatively correlated with risks of MS and lower SOD activity andβ-carotene level appeared to be associated with more MS components. Serum oxidative status is useful in assessing the severity of MS.

  12. Methotrexate Increases Skeletal Muscle GLUT4 Expression and Improves Metabolic Control in Experimental Diabetes

    Directory of Open Access Journals (Sweden)

    Giuseppina T. Russo

    2012-01-01

    Full Text Available Long-term administration of 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR mimics the effects of endurance exercise by activating AMP kinase and by increasing skeletal muscle expression of GLUT4 glucose transporter. AICAR is an intermediate in the purine de novo synthesis, and its tissue concentrations can be increased, in vivo, by low doses of methotrexate (MTX through the inhibition of the enzyme AICAR transformylase. We report here the first evidence that, in experimental type 2 diabetes, chronic treatment with low doses of MTX increases skeletal muscle GLUT4 expression and improves metabolic control. MTX (0.5 mg/kg body weight or vehicle was administered intraperitoneally, once a week for 4 weeks, to genetically diabetic female C57BL/KsJ-m+/+Leptdb mice (db+/db+ and their normoglycemic littermates (db+/+m. In the db+/db+ mice, MTX treatment was associated with a ∼2-fold increase in skeletal muscle GLUT4 protein concentration and a >4-fold increase in GLUT4 mRNA expression (P<0.01, all, as compared to vehicle-treated mice; no significant differences were noted in controls. MTX treatment was also associated with a significant reduction of glucose and insulin serum concentrations in diabetic mice (P<0.001, and glucose levels only (P<0.05 in controls. These data indicate a different route to increase skeletal muscle GLUT4 expression, through the potential inhibition of the enzyme AICAR transformylase.

  13. Gut microbiota controls adipose tissue expansion, gut barrier and glucose metabolism: novel insights into molecular targets and interventions using prebiotics.

    Science.gov (United States)

    Geurts, L; Neyrinck, A M; Delzenne, N M; Knauf, C; Cani, P D

    2014-03-01

    Crosstalk between organs is crucial for controlling numerous homeostatic systems (e.g. energy balance, glucose metabolism and immunity). Several pathological conditions, such as obesity and type 2 diabetes, are characterised by a loss of or excessive inter-organ communication that contributes to the development of disease. Recently, we and others have identified several mechanisms linking the gut microbiota with the development of obesity and associated disorders (e.g. insulin resistance, type 2 diabetes, hepatic steatosis). Among these, we described the concept of metabolic endotoxaemia (increase in plasma lipopolysaccharide levels) as one of the triggering factors leading to the development of metabolic inflammation and insulin resistance. Growing evidence suggests that gut microbes contribute to the onset of low-grade inflammation characterising these metabolic disorders via mechanisms associated with gut barrier dysfunctions. We have demonstrated that enteroendocrine cells (producing glucagon-like peptide-1, peptide YY and glucagon-like peptide-2) and the endocannabinoid system control gut permeability and metabolic endotoxaemia. Recently, we hypothesised that specific metabolic dysregulations occurring at the level of numerous organs (e.g. gut, adipose tissue, muscles, liver and brain) rely from gut microbiota modifications. In this review, we discuss the mechanisms linking gut permeability, adipose tissue metabolism, and glucose homeostasis, and recent findings that show interactions between the gut microbiota, the endocannabinoid system and the apelinergic system. These specific systems are discussed in the context of the gut-to-peripheral organ axis (intestine, adipose tissue and brain) and impacts on metabolic regulation. In the present review, we also briefly describe the impact of a variety of non-digestible nutrients (i.e. inulin-type fructans, arabinoxylans, chitin glucans and polyphenols). Their effects on the composition of the gut microbiota and

  14. Correlation between metabolic controls and changes in retina in patients having diabetes

    Directory of Open Access Journals (Sweden)

    Janićijević-Petrović Mirjana A.

    2014-01-01

    Full Text Available Introduction. Diabetes mellitus is as old as the human race. Retinopathy, being one of complications of diabetes mellitus, is the most common cause of blindness. This study was aimed at analyzing the correlation between retinopathy and duration of disease, metabolic control, and obesity. Material and Methods. The study sample consisted of 135 patients divided into the experimental group of 90 patients with retinopathy and the control group of 45 patients without retinopathy. The patients were examined according to standard protocols: anamneses, endocrinology, ophthalmology exams, biochemical analyses, and anthropometric measurements. Results. The average age of patients was 60.13 ± 9.29 in the experimental group, while it was 57.55 ± 4.85 in the control group. The average duration of disease was 11.71 ± 5.8 and 14.40 ± 7.68 in the control group experimental group, respectively. The following statistically essential differences between the control and experimental group were found: in duration of disease (11.71 ± 5.85; 14.40 ± 7.68; r = 0.000, in glycemia (7.02 ± 2.20; 8.34 ± 3.18; p = 0.000, in glycosylated hemoglobin A1C (HbA1C (7.16 ± 1.37; 8.22 ± 2.05; r = 0.000, in triglycerides (1.92 ± 0.72; 2.63 ± 1.60; r = 0.001, and in body mass index (23.94 ± 2.65; 27.66 ± 15.13; r = 0.000. Conclusion. There is a positive correlation between duration of disease, glycosylated hemoglobin A1C, triglycerides, body mass index - obesity and retinopathy. A significant statistical correlation among those parameters has been found in patients with diabetic retinopathy.

  15. Influence of the metabolic control on latency values of visual evoked potentials (VEP) in patients with diabetes mellitus type 1.

    Science.gov (United States)

    Matanovic, Dragana; Popovic, Srdjan; Parapid, Biljana; Petronic, Ivana; Cirovic, Dragana; Nikolic, Dejan

    2012-12-01

    The aim of our study was to investigate the relationship between the metabolic control parameters of diabetes mellitus (glycemia and HbA1c) and visual evoked potentials (VEP) latency values. The study included 61 patients with diabetes mellitus type 1 that were hospitalized at the Clinic for Endocrinology, Diabetes and Metabolic Diseases due to the poor metabolic control. All patients were divided into 3 groups. Group 1 consisted of patients on conventional insulin therapy (CT); Group 2 included patients on CT at the moment of hospitalization, with a change towards intensified insulin therapy (IIT); and Group 3 consisted of patients on IIT. Patients with diabetic retinopathy (DR) were excluded from the study. Metabolic control (glycemia and HbA1c) and VEP parameters were compared at the beginning of the study and six months later. After six months of strict glycoregulation, significant improvement in VEP parameters was followed by significant improvement of evaluated parameters of metabolic control. We found statistically significant reduction in frequency of pathological VEP findings, prolonged P100 latency and low amplitude potentials in Group 2, while in Groups 1 and 3 we found that these parameters did not significantly changed but the frequencies were lower. The VEP testing is a noninvasive diagnostic procedure which may help in early diagnosis of DR, prognosis during the metabolic control and treatment. If changes in the retina could be detected before DR is noticed using this noninvasive diagnostic procedure and include patients in a strict glycoregulation, we could be in the position to prevent serious complications that may cause blindness.

  16. Cascaded-cladding-pumped cascaded Raman fiber amplifier.

    Science.gov (United States)

    Jiang, Huawei; Zhang, Lei; Feng, Yan

    2015-06-01

    The conversion efficiency of double-clad Raman fiber laser is limited by the cladding-to-core area ratio. To get high conversion efficiency, the inner-cladding-to-core area ratio has to be less than about 8, which limits the brightness enhancement. To overcome the problem, a cascaded-cladding-pumped cascaded Raman fiber laser with multiple-clad fiber as the Raman gain medium is proposed. A theoretical model of Raman fiber amplifier with multiple-clad fiber is developed, and numerical simulation proves that the proposed scheme can improve the conversion efficiency and brightness enhancement of cladding pumped Raman fiber laser.

  17. Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding%Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In a recent issue of PNAS, Professor Wu Donghai of Guangzhou Institutes of Biomedicine and Health (GIBH) and his colleagues published a paper titled "Important roles of brain-specific carnitine palmitoyltransferase and ceramide metabolism in leptin hypothalamic control of feeding". Prof. Wu has receivedsustained support from NSFC since 2006.

  18. Antinociceptive effects, metabolism and disposition of ketamine in ponies under target-controlled drug infusion

    Science.gov (United States)

    Knobloch, M.; Portier, C.J.; Levionnois, O.L.; Theurillat, R.; Thormann, W.; Spadavecchia, C.; Mevissen, M.

    2007-01-01

    Ketamine is widely used as an anesthetic in a variety of drug combinations in human and veterinary medicine. Recently, it gained new interest for use in long-term pain therapy administered in sub-anesthetic doses in humans and animals. The purpose of this study was to develop a physiologically based pharmacokinetic (PBPk) model for ketamine in ponies and to investigate the effect of low-dose ketamine infusion on the amplitude and the duration of the nociceptive withdrawal reflex (NWR). A target-controlled infusion (TCI) of ketamine with a target plasma level of 1 μg/ml S-ketamine over 120 min under isoflurane anesthesia was performed in Shetland ponies. A quantitative electromyographic assessment of the NWR was done before, during and after the TCI. Plasma levels of R-/S-ketamine and R-/S-norketamine were determined by enantioselective capillary electrophoresis. These data and two additional data sets from bolus studies were used to build a PBPk model for ketamine in ponies. The peak-to-peak amplitude and the duration of the NWR decreased significantly during TCI and returned slowly toward baseline values after the end of TCI. The PBPk model provides reliable prediction of plasma and tissue levels of R- and S-ketamine and R- and S-norketamine. Furthermore, biotransformation of ketamine takes place in the liver and in the lung via first-pass metabolism. Plasma concentrations of S-norketamine were higher compared to R-norketamine during TCI at all time points. Analysis of the data suggested identical biotransformation rates from the parent compounds to the principle metabolites (R- and S-norketamine) but different downstream metabolism to further metabolites. The PBPk model can provide predictions of R- and S-ketamine and norketamine concentrations in other clinical settings (e.g. horses). PMID:16919695

  19. TFE3 controls lipid metabolism in adipose tissue of male mice by suppressing lipolysis and thermogenesis.

    Science.gov (United States)

    Fujimoto, Yuri; Nakagawa, Yoshimi; Satoh, Aoi; Okuda, Kanako; Shingyouchi, Akiko; Naka, Ayano; Matsuzaka, Takashi; Iwasaki, Hitoshi; Kobayashi, Kazuto; Yahagi, Naoya; Shimada, Masako; Yatoh, Shigeru; Suzuki, Hiroaki; Yogosawa, Satomi; Izumi, Tetsuro; Sone, Hirohito; Urayama, Osamu; Yamada, Nobuhiro; Shimano, Hitoshi

    2013-10-01

    Transcription factor E3 (TFE3) is a transcription factor that binds to E-box motifs and promotes energy metabolism-related genes. We previously reported that TFE3 directly binds to the insulin receptor substrate-2 promoter in the liver, resulting in increased insulin response. However, the role of TFE3 in other tissues remains unclear. In this study, we generated adipose-specific TFE3 transgenic (aP2-TFE3 Tg) mice. These mice had a higher weight of white adipose tissue (WAT) and brown adipose tissue than wild-type (WT) mice under fasting conditions. Lipase activity in the WAT in these mice was lower than that in the WT mice. The mRNA level of adipose triglyceride lipase (ATGL), the rate-limiting enzyme for adipocyte lipolysis, was significantly decreased in aP2-TFE3 Tg mice. The expression of Foxo1, which directly activates ATGL expression, was also suppressed in transgenic mice. Promoter analysis confirmed that TFE3 suppressed promoter activities of the ATGL gene. In contrast, G0S2 and Perilipin1, which attenuate ATGL activity, were higher in transgenic mice than in WT mice. These results indicated that the decrease in lipase activity in adipose tissues was due to a decrease in ATGL expression and suppression of ATGL activity. We also showed that thermogenesis was suppressed in aP2-TFE3 Tg mice. The decrease in lipolysis in WAT of aP2-TFE3 Tg mice inhibited the supply of fatty acids to brown adipose tissue, resulting in the inhibition of the expression of thermogenesis-related genes such as UCP1. Our data provide new evidence that TFE3 regulates lipid metabolism by controlling the gene expression related to lipolysis and thermogenesis in adipose tissue.

  20. Phosphoenolpyruvate carboxykinase and the critical role of cataplerosis in the control of hepatic metabolism

    Directory of Open Access Journals (Sweden)

    Kalhan Satish C

    2005-11-01

    Full Text Available Abstract Background The metabolic function of PEPCK-C is not fully understood; deletion of the gene for the enzyme in mice provides an opportunity to fully assess its function. Methods The gene for the cytosolic form of phosphoenolpyruvate carboxykinase (GTP (EC 4.1.1.32 (PEPCK-C was deleted in mice by homologous recombination (PEPCK-C-/- mice and the metabolic consequences assessed. Results PEPCK-C-/- mice became severely hypoglycemic by day two after birth and then died with profound hypoglycemia (12 mg/dl. The mice had milk in their stomachs at day two after birth and the administration of glucose raised the concentration of blood glucose in the mice but did not result in an increased survival. PEPCK-C-/- mice have two to three times the hepatic triglyceride content as control littermates on the second day after birth. These mice also had an elevation of lactate (2.5 times, β-hydroxybutyrate (3 times and triglyceride (50% in their blood, as compared to control animals. On day two after birth, alanine, glycine, glutamine, glutamate, aspartate and asparagine were elevated in the blood of the PEPCK-C-/- mice and the blood urea nitrogen concentration was increased by 2-fold. The rate of oxidation of [2-14C]-acetate, and [5-14C]-glutamate to 14CO2 by liver slices from PEPCK-C-/- mice at two days of age was greatly reduced, as was the rate of fatty acid synthesis from acetate and glucose. As predicted by the lack of PEPCK-C, the concentration of malate in the livers of the PEPCK-C-/- mice was 10 times that of controls. Conclusion We conclude that PEPCK-C is required not only for gluconeogenesis and glyceroneogenesis but also for cataplerosis (i.e. the removal of citric acid cycle anions and that the failure of this process in the livers of PEPCK-C-/- mice results in a marked reduction in citric acid cycle flux and the shunting of hepatic lipid into triglyceride, resulting in a fatty liver.

  1. Effect of Acarbose on Control of Metabolic Parameters in Patients with Diabetes Type 1

    Directory of Open Access Journals (Sweden)

    A. Ziaee

    2012-07-01

    Full Text Available Introduction & Objective: Acarbose is an intestinal alpha-glucosidase inhibitor that delays absorption of carbohydrates. Findings of some studies show that it has been effective in better control of blood glucose in patients with diabetes type 1. The goal of this study is to investigate the effect of administration of acarbose on glycemic & lipid parameters and daily insulin requirements and tolerability in type 1 diabetic patient.Materials & Methods: This was a clinical trial randomized double blind placebo controlled study. Performed on patients with history of at least 1 year diabetes type 1 and had HbA1c≥7.5%. Patients with Cr≥2, partial GI obstruction or IBD were excluded from the study. 45 patients were randomized to be administered acarbose or placebo for 12 weeks. Initial dose of acarbose was 25 mg T.D.S for 2 weeks, and then it was increased to 50 mg T.D.S for 10 weeks. BMI, FBS, 2hpp, HbA1c, Total cholesterol, HDL, LDL, TG and Insulin dosage were investigated monthly.Results: The values of BMI, FBS, 2hpp, HbA1c, Total cholesterol, and TG & Insulin requirements decreased significantly in the case group compared to the controls (P=0.003, P=0.005, P<0.001, P=0.001, P=0.003, P<0.001, P<0.001, respectively; but no significant changes were observed in HDL &LDL levels. Conclusion: Administration of acarbose together with insulin to type 1 diabetic patient can be valuable in improving metabolic control (BMI, FBS, 2hpp, HbA1c, Total cholesterol and TG.(Sci J Hamadan Univ Med Sci 2012;19(2:5-10

  2. Physical activity, sedentary behaviour and metabolic control following stroke: a cross-sectional and longitudinal study.

    Directory of Open Access Journals (Sweden)

    Sarah A Moore

    Full Text Available BACKGROUND: Physical activity and sedentary behaviour are key moderators of cardiovascular disease risk and metabolic control. Despite the importance of a physically active lifestyle, little is known about the effects of stroke on physical activity. We assessed physical activity and sedentary behaviour at three time points following stroke compared to a healthy control group. METHODS: Physical activity and sedentary behaviour were objectively measured using a portable multi-sensor array in 31 stroke participants (73±9 years, National Institute of Health Stroke Scale 2±2, mobile 10 metres with/without aid within seven days and at three and six months. Stroke data were compared with an age, sex and body mass index matched healthy control group (n = 31. RESULTS: Within seven days of stroke, total energy expenditure and physical activity were significantly lower and sedentary time higher in the stroke group compared to controls (total energy expenditure 1840±354 vs. 2220±489 kcal, physical activity 28±32 vs. 79±46 min/day, steps 3111±2290 vs. 7996±2649, sedentary time 1383±42 vs. 1339±44 min/day, p<0.01. At three months physical activity levels had increased (64±58 min/day but plateaued by six months (66±68 min/day. CONCLUSIONS: Physical activity levels are reduced immediately post-stroke and remain below recommended levels for health and wellbeing at the three and six month time points. Clinicians should explore methods to increase physical activity and reduce sedentary behaviour in both the acute and later stages following stroke.

  3. Liver enzymes and metabolic syndrome: a large-scale case-control study.

    Science.gov (United States)

    Zhang, Lu; Ma, Xiangyu; Jiang, Zhi; Zhang, Kejun; Zhang, Mengxuan; Li, Yafei; Zhao, Xiaolan; Xiong, Hongyan

    2015-09-29

    Previous studies suggested that elevated liver enzymes could be used as potential novel biomarkers of Metabolic syndrome (MetS) and its clinical outcomes, although the results were inconsistent and the conclusions were underpowered. A case-control study with 6,268 MetS subjects and 6,330 frequency-matched healthy controls was conducted to systematically evaluated levels of four liver enzymes (ALT, AST, GGT and ALP), both in overall populations and in subjects with normal liver enzymes, with MetS risk using both quartiles and continuous unit of liver enzymes. We found significant associations were detected for all above analyses. Compared with quartile 1 (Q1), other quartiles have significant higher MetS risk, with ORs ranging from 1.15 to 18.15. The highest effected was detected for GGT, for which the OR value for the highest versus lowest quartile was 18.15 (95% CI: 15.7-20.9). Mutual adjustment proved the independence of the relations for all four liver enzymes. Sensitivity analyses didn't materially changed the trend. To the best of our knowledge, this study should be the largest, which aimed at evaluating the association between liver enzymes measures and MetS risk. The results can better support that liver enzyme levels could be used as clinical predictors of MetS.

  4. A regulatory framework for shoot stem cell control integrating metabolic, transcriptional, and phytohormone signals.

    Science.gov (United States)

    Schuster, Christoph; Gaillochet, Christophe; Medzihradszky, Anna; Busch, Wolfgang; Daum, Gabor; Krebs, Melanie; Kehle, Andreas; Lohmann, Jan U

    2014-02-24

    Plants continuously maintain pluripotent stem cells embedded in specialized tissues called meristems, which drive long-term growth and organogenesis. Stem cell fate in the shoot apical meristem (SAM) is controlled by the homeodomain transcription factor WUSCHEL (WUS) expressed in the niche adjacent to the stem cells. Here, we demonstrate that the bHLH transcription factor HECATE1 (HEC1) is a target of WUS and that it contributes to SAM function by promoting stem cell proliferation, while antagonizing niche cell activity. HEC1 represses the stem cell regulators WUS and CLAVATA3 (CLV3) and, like WUS, controls genes with functions in metabolism and hormone signaling. Among the targets shared by HEC1 and WUS are phytohormone response regulators, which we show to act as mobile signals in a universal feedback system. Thus, our work sheds light on the mechanisms guiding meristem function and suggests that the underlying regulatory system is far more complex than previously anticipated. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Purine-Metabolizing Ectoenzymes Control IL-8 Production in Human Colon HT-29 Cells

    Directory of Open Access Journals (Sweden)

    Fariborz Bahrami

    2014-01-01

    Full Text Available Interleukin-8 (IL-8 plays key roles in both chronic inflammatory diseases and tumor modulation. We previously observed that IL-8 secretion and function can be modulated by nucleotide (P2 receptors. Here we investigated whether IL-8 release by intestinal epithelial HT-29 cells, a cancer cell line, is modulated by extracellular nucleotide metabolism. We first identified that HT-29 cells regulated adenosine and adenine nucleotide concentration at their surface by the expression of the ectoenzymes NTPDase2, ecto-5′-nucleotidase, and adenylate kinase. The expression of the ectoenzymes was evaluated by RT-PCR, qPCR, and immunoblotting, and their activity was analyzed by RP-HPLC of the products and by detection of Pi produced from the hydrolysis of ATP, ADP, and AMP. In response to poly (I:C, with or without ATP and/or ADP, HT-29 cells released IL-8 and this secretion was modulated by the presence of NTPDase2 and adenylate kinase. Taken together, these results demonstrate the presence of 3 ectoenzymes at the surface of HT-29 cells that control nucleotide levels and adenosine production (NTPDase2, ecto-5′-nucleotidase and adenylate kinase and that P2 receptor-mediated signaling controls IL-8 release in HT-29 cells which is modulated by the presence of NTPDase2 and adenylate kinase.

  6. PANSYM: a symbolic equation generator for mathematical modelling, analysis and control of metabolic and pharmacokinetic systems.

    Science.gov (United States)

    Thomaseth, K

    1994-02-14

    Software is presented for automatic generation of first-order ordinary differential equations (ODE) that arise from lumped parameter representations of metabolic and pharmacokinetic systems. The definition of system structures is accomplished by fractional transfer rates between state variables, together with input/output equations and initial conditions of state variables. General non-linear mathematical expressions can be assigned to all structure definition items. The software parses and interprets the system definitions and generates symbolically the mathematical expression of the model's set of ODE. In addition, symbolic derivatives of state equations are determined with respect to model parameters, state variables and external inputs. These derivatives represent the constituents of systems of sensitivity-differential and adjoint-differential equations that arise in identification and optimal control problems. Finally, output routines generate source code that, once compiled and linked to simulation programs, allows efficient numerical integration of the system of ODE. This software has been developed in PROLOG on Macintosh computers and has been extensively used with the programming environment MATLAB. Possible applications of this software include model building, sensitivity analysis, identification, optimal experiment design and numerical solution of optimal control problems.

  7. Protein Kinase B Controls Transcriptional Programs that Direct Cytotoxic T Cell Fate but Is Dispensable for T Cell Metabolism

    Science.gov (United States)

    Macintyre, Andrew N.; Finlay, David; Preston, Gavin; Sinclair, Linda V.; Waugh, Caryll M.; Tamas, Peter; Feijoo, Carmen; Okkenhaug, Klaus; Cantrell, Doreen A.

    2011-01-01

    Summary In cytotoxic T cells (CTL), Akt, also known as protein kinase B, is activated by the T cell antigen receptor (TCR) and the cytokine interleukin 2 (IL-2). Akt can control cell metabolism in many cell types but whether this role is important for CTL function has not been determined. Here we have shown that Akt does not mediate IL-2- or TCR-induced cell metabolic responses; rather, this role is assumed by other Akt-related kinases. There is, however, a nonredundant role for sustained and strong activation of Akt in CTL to coordinate the TCR- and IL-2-induced transcriptional programs that control expression of key cytolytic effector molecules, adhesion molecules, and cytokine and chemokine receptors that distinguish effector versus memory and naive T cells. Akt is thus dispensable for metabolism, but the strength and duration of Akt activity dictates the CTL transcriptional program and determines CTL fate. PMID:21295499

  8. Effect of fruits and vegetables on metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Shin, Jin Young; Kim, Ji Young; Kang, Hee Tak; Han, Kyung Hwa; Shim, Jae Yong

    2015-01-01

    Evidence regarding the effect of fruit and vegetable consumption on metabolic syndrome remains inconclusive. Using MEDLINE, EMBASE, and Cochrane, we searched for relevant studies published before 10 December 2013. Of the 383 articles identified, eight randomized controlled trials with 396 participants (205 in intervention groups and 191 in control groups) were included in the final analyses. Fruit and vegetable intake was associated with a reduction in diastolic blood pressure (standardized mean difference: -0.29; 95% confidence interval: -0.57 to -0.02; p = 0.04); however, such intake did not affect waist circumference, systolic blood pressure, fasting glucose, high-density lipoprotein cholesterol, and triglyceride levels in metabolic syndrome patients. In a subgroup analysis, there were no statistically significant differences found according to the intervention period and provision type. Our results suggest an inverse association between fruit and vegetable consumption and diastolic blood pressure in metabolic syndrome patients.

  9. Artificial neural network cascade identifies multi-P450 inhibitors in natural compounds

    OpenAIRE

    Li, Zhangming; Li, Yan; Sun, Lu; Tang, Yun; Liu, Lanru; Zhu, Wenliang

    2015-01-01

    Substantial evidence has shown that most exogenous substances are metabolized by multiple cytochrome P450 (P450) enzymes instead of by merely one P450 isoform. Thus, multi-P450 inhibition leads to greater drug-drug interaction risk than specific P450 inhibition. Herein, we innovatively established an artificial neural network cascade (NNC) model composed of 23 cascaded networks in a ladder-like framework to identify potential multi-P450 inhibitors among natural compounds by integrating 12 mol...

  10. Lifestyle modification and weight reduction among low-income patients with the metabolic syndrome: the CHARMS randomized controlled trial.

    Science.gov (United States)

    Chirinos, Diana A; Goldberg, Ronald B; Llabre, Maria M; Gellman, Marc; Gutt, Miriam; McCalla, Judith; Mendez, Armando; Schneiderman, Neil

    2016-06-01

    Although weight is an important intervention target among patients with metabolic syndrome, few trials have recruited low-income minority populations. The Community Health and Risk-reduction for Metabolic Syndrome randomized controlled trial aimed to examine the effects of a lifestyle intervention on weight and metabolic syndrome components among low-income minority adults. We randomized 120 adults with metabolic syndrome to standard medical care (N = 60) or a lifestyle intervention (N = 60). Using an intent-to-treat approach, we found significant intervention effects on weight [B = -0.452; SE = 0.122; 95 % confidence intervals (CI) -0.653 to -0.251) and glucose levels at 6-months (B = -0.522, SE = 0.234, 95 % CI -0.907 to -0.138). These changes were maintained through the 12-month assessment. No significant effects were observed on insulin resistance or other metabolic syndrome components. Our intervention was successful in achieving modest but significant weight loss and reduction in fasting glucose among low-income minority subjects with metabolic syndrome.

  11. Autoregressive cascades on random networks

    Science.gov (United States)

    Iyer, Srikanth K.; Vaze, Rahul; Narasimha, Dheeraj

    2016-04-01

    A network cascade model that captures many real-life correlated node failures in large networks via load redistribution is studied. The considered model is well suited for networks where physical quantities are transmitted, e.g., studying large scale outages in electrical power grids, gridlocks in road networks, and connectivity breakdown in communication networks, etc. For this model, a phase transition is established, i.e., existence of critical thresholds above or below which a small number of node failures lead to a global cascade of network failures or not. Theoretical bounds are obtained for the phase transition on the critical capacity parameter that determines the threshold above and below which cascade appears or disappears, respectively, that are shown to closely follow numerical simulation results.

  12. Infectious Agents Trigger Trophic Cascades.

    Science.gov (United States)

    Buck, Julia C; Ripple, William J

    2017-09-01

    Most demonstrated trophic cascades originate with predators, but infectious agents can also cause top-down indirect effects in ecosystems. Here we synthesize the literature on trophic cascades initiated by infectious agents including parasitoids, pathogens, parasitic castrators, macroparasites, and trophically transmitted parasites. Like predators, infectious agents can cause density-mediated and trait-mediated indirect effects through their direct consumptive and nonconsumptive effects respectively. Unlike most predators, however, infectious agents are not fully and immediately lethal to their victims, so their consumptive effects can also trigger trait-mediated indirect effects. We find that the frequency of trophic cascades reported for different consumer types scales with consumer lethality. Furthermore, we emphasize the value of uniting predator-prey and parasite-host theory under a general consumer-resource framework. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Design and rationale of a randomized controlled trial of melatonin supplementation in men and women with the metabolic syndrome

    Directory of Open Access Journals (Sweden)

    Terry PD

    2013-03-01

    Full Text Available Paul D Terry,1 Abhinav Goyal,2,3 Lawrence S Phillips,3 Hillary M Superak,4 Michael H Kutner4 1Departments of Public Health and Surgery, University of Tennessee, Knoxville, TN, 2Department of Epidemiology, Emory Rollins School of Public Health, 3Department of Medicine, Emory School of Medicine, 4Department of Biostatistics and Bioinformatics, Emory Rollins School of Public Health, Atlanta, GA, USA Background: The metabolic syndrome is a constellation of interrelated metabolic risk factors that appear to increase the risk of atherosclerotic cardiovascular disease, type 2 diabetes mellitus, and possibly some cancers. Animal studies and observational clinical data in humans suggest that supplemental melatonin may ameliorate a number of components of the metabolic syndrome, including elevated glucose, elevated blood pressure, dyslipidemia, and obesity. The primary objective of this clinical trial was to determine the feasibility, efficacy, and safety of melatonin supplementation in men and women with the metabolic syndrome. Methods: Thirty-nine men and women of mixed race/ethnicity were enrolled into a randomized, double-blind, placebo-controlled clinical trial with two arms: placebo for 10 weeks followed by melatonin for 10 weeks, or vice versa, with an interval 6-week washout period, in a crossover trial design. Outcome measures include metabolic syndrome components (blood pressure, glucose, triglycerides, high-density lipoprotein cholesterol, waist circumference, oxidative stress, and inflammation biomarkers. These biomarkers, along with sleep duration and quality and pretreatment endogenous melatonin levels, were measured to explore possible underlying biologic mechanisms. Discussion: This trial will provide knowledge of the effects of melatonin in metabolic syndrome subjects, and lay the groundwork for future clinical trials of melatonin in metabolic syndrome subjects. Keywords: melatonin, metabolic syndrome, diabetes, blood pressure, sleep

  14. 基于PID算法的炉窑温度串级控制系统设计%Furnace Temperature Cascade Control System Design Based on PID Algorithm

    Institute of Scientific and Technical Information of China (English)

    罗及红

    2012-01-01

    The use of temperature sensors, transmitters, PLC and its A/D conversion device MAD02 and the computer, with the furnace as the object to the furnace outlet temperature, main controlled parameter, in order to furnace temperature for secondary controlled parameters, with resistance wire of the heating furnace voltage as a control parameter, PLC controller, design of furnace temperature series level control system, using PID algorithm for the PLC program design, realization of the furnace temperature setpoint control. After the debugging experiment, comprehensive error of only 0. 926degrees C, fully meet the system error in the range of 2DEG C control requirements.%利用温度传感器、变送器、PLC及其配套的A/D转换器件MAD02和上位计算机,以炉窑为被控对象,以炉窑出口气温为主被控参数,以炉膛内的气温为副被控参数,以加热炉电阻丝电压为控制参数,以PLC为控制器,设计了炉窑温度串级控制系统,运用PID算法进行了PLC程序设计,实现了炉窑气温的定值控制;经调试实验证明,综合误差仅为0.926℃,充分满足了本系统误差范围在2℃以内的控制要求.

  15. Voltage balancing control algorithm for cascaded H-bridge rectifier based on active power feedback%基于功率反馈的H桥级联型整流器电压平衡控制算法

    Institute of Scientific and Technical Information of China (English)

    陶兴华; 李永东; 孙敏

    2011-01-01

    A power-feedback based control algorithm was developed to balance the DC-link voltages in a cascaded H-bridge(CHB) pulse width modulation(PWM) rectifier.The average mathematic model of the CHB rectifier is built.The relationship between the modulation index and the active power of cells is deduced by the mathematic analysis,from which the voltage balancing control method can be derived.Moreover,the feasibility of the proposed method is also discussed.Simulations on a four-cell CHB rectifier and tests on a two-cell prototype indicate that the CHB rectifier can achieve good performance on both DC-link voltage balancing and grid current regulation.%提出了一种基于功率反馈的直流母线电压平衡算法,用于对H桥级联型(cascaded H-bridge,CHB)脉冲宽度调制(PWM)整流器的电压控制。建立了CHB整流器基于平均意义下的数学模型;通过数学分析得到了各级整流器稳态工作时有功功率与调制比之间的关系,依此推出基于功率反馈的电压平衡控制算法,并对该算法的适用条件进行讨论;在MATLAB上进行了4级级联的系统仿真,搭建2级级联的实验样机进行实验研究。仿真与实验结果表明:该算法在满足适用范围的前提条件下,能够实现对多级CHB整流器直流母线电压的平衡控制,

  16. Positional information generated by spatially distributed signaling cascades.

    Directory of Open Access Journals (Sweden)

    Javier Muñoz-García

    2009-03-01

    Full Text Available The temporal and stationary behavior of protein modification cascades has been extensively studied, yet little is known about the spatial aspects of signal propagation. We have previously shown that the spatial separation of opposing enzymes, such as a kinase and a phosphatase, creates signaling activity gradients. Here we show under what conditions signals stall in the space or robustly propagate through spatially distributed signaling cascades. Robust signal propagation results in activity gradients with long plateaus, which abruptly decay at successive spatial locations. We derive an approximate analytical solution that relates the maximal amplitude and propagation length of each activation profile with the cascade level, protein diffusivity, and the ratio of the opposing enzyme activities. The control of the spatial signal propagation appears to be very different from the control of transient temporal responses for spatially homogenous cascades. For spatially distributed cascades where activating and deactivating enzymes operate far from saturation, the ratio of the opposing enzyme activities is shown to be a key parameter controlling signal propagation. The signaling gradients characteristic for robust signal propagation exemplify a pattern formation mechanism that generates precise spatial guidance for multiple cellular processes and conveys information about the cell size to the nucleus.

  17. Teenage girls with type 1 diabetes have poorer metabolic control than boys and face more complications in early adulthood

    DEFF Research Database (Denmark)

    Samuelsson, Ulf; Anderzén, Johan; Gudbjörnsdottir, Soffia

    2016-01-01

    AIMS: To compare metabolic control between males and females with type 1 diabetes during adolescence and as young adults, and relate it to microvascular complications. METHODS: Data concerning 4000 adolescents with type 1 diabetes registered in the Swedish paediatric diabetes quality registry, an...

  18. Interaction between ArgR and AhrC controls regulation of arginine metabolism in Lactococcus lactis

    NARCIS (Netherlands)

    Larsen, R; Kok, J; Kuipers, OP

    2005-01-01

    The expression of arginine metabolism in Lactococcus lactis is controlled by the two homologous transcriptional regulators ArgR and AhrC. Genome sequence analyses have shown that the occurrence of multiple homologues of the ArgR family of transcriptional regulators is a common feature of many low-G

  19. Small RNA-dependent expression of secondary metabolism is controlled by Krebs cycle function in Pseudomonas fluorescens.

    Science.gov (United States)

    Takeuchi, Kasumi; Kiefer, Patrick; Reimmann, Cornelia; Keel, Christoph; Dubuis, Christophe; Rolli, Joëlle; Vorholt, Julia A; Haas, Dieter

    2009-12-11

    Pseudomonas fluorescens CHA0, an antagonist of phytopathogenic fungi in the rhizosphere of crop plants, elaborates and excretes several secondary metabolites with antibiotic properties. Their synthesis depends on three small RNAs (RsmX, RsmY, and RsmZ), whose expression is positively controlled by the GacS-GacA two-component system at high cell population densities. To find regulatory links between primary and secondary metabolism in P. fluorescens and in the related species Pseudomonas aeruginosa, we searched for null mutations that affected central carbon metabolism as well as the expression of rsmY-gfp and rsmZ-gfp reporter constructs but without slowing down the growth rate in rich media. Mutation in the pycAB genes (for pyruvate carboxylase) led to down-regulation of rsmXYZ and secondary metabolism, whereas mutation in fumA (for a fumarase isoenzyme) resulted in up-regulation of the three small RNAs and secondary metabolism in the absence of detectable nutrient limitation. These effects required the GacS sensor kinase but not the accessory sensors RetS and LadS. An analysis of intracellular metabolites in P. fluorescens revealed a strong positive correlation between small RNA expression and the pools of 2-oxoglutarate, succinate, and fumarate. We conclude that Krebs cycle intermediates (already known to control GacA-dependent virulence factors in P. aeruginosa) exert a critical trigger function in secondary metabolism via the expression of GacA-dependent small RNAs.

  20. Comparative genomic reconstruction of transcriptional networks controlling central metabolism in the Shewanella genus

    Energy Technology Data Exchange (ETDEWEB)

    Rodionov, Dmitry A.; Novichkov, Pavel; Stavrovskaya, Elena D.; Rodionova, Irina A.; Li, Xiaoqing; Kazanov, Marat D.; Ravcheev, Dmitry A.; Gerasimova, Anna V.; Kazakov, Alexey E.; Kovaleva, Galina Y.; Permina, Elizabeth A.; Laikova, Olga N.; Overbeek, Ross; Romine, Margaret F.; Fredrickson, Jim K.; Arkin, Adam P.; Dubchak, Inna; Osterman, Andrei L.; Gelfand, Mikhail S.

    2011-06-15

    Genome-scale prediction of gene regulation and reconstruction of transcriptional regulatory networks in bacteria is one of the critical tasks of modern genomics. Despite the growing number of genome-scale gene expression studies, our abilities to convert the results of these studies into accurate regulatory annotations and to project them from model to other organisms are extremely limited. The comparative genomics approaches and computational identification of regulatory sites are useful for the in silico reconstruction of transcriptional regulatory networks in bacteria. The Shewanella genus is comprised of metabolically versatile gamma-proteobacteria, whose lifestyles and natural environments are substantially different from Escherichia coli and other model bacterial species. To explore conservation and variations in the Shewanella transcriptional networks we analyzed the repertoire of transcription factors and performed genomics-based reconstruction and comparative analysis of regulons in 16 Shewanella genomes. The inferred regulatory network includes 82 transcription factors and their DNA binding sites, 8 riboswitches and 6 translational attenuators. Forty five regulons were newly inferred from the genome context analysis, whereas others were propagated from previously characterized regulons in the Enterobacteria and Pseudomonas spp.. However, even orthologous regulators with conserved DNA-binding motifs may control substantially different gene sets, revealing striking differences in regulatory strategies between the Shewanella spp. and E. coli. Multiple examples of regulatory network rewiring include regulon contraction and expansion (as in the case of PdhR, HexR, FadR), and numerous cases of recruiting non-orthologous regulators to control equivalent pathways (e.g. NagR for N-acetylglucosamine catabolism and PsrA for fatty acid degradation) and, conversely, orthologous regulators to control distinct pathways (e.g. TyrR, ArgR, Crp).

  1. Spatial Organization of Enzyme Cascade on a DNA Origami Nanostructure.

    Science.gov (United States)

    Fu, Jinglin; Li, Tianran

    2017-01-01

    Self-assembled DNA nanostructures hold great promise to organize multi-enzyme systems with the precise control of the geometric arrangements. Enzymes modified with single-stranded DNA anchors are assembled onto the DNA origami tiles by hybridizing with the corresponding complementary strands displayed on the surface of the DNA nanostructures. Here, we describe a protocol of assembling a two-enzyme cascade on a discrete, rectangular DNA origami tile, where the distance between enzymes is precisely controlled for investigating the distance-dependent cascade activities.

  2. Effects of Periodontal Therapy on Metabolic Control in Patients With Type 2 Diabetes Mellitus and Periodontal Disease

    OpenAIRE

    Wang, Tze-Fang; Jen, I-An; Chou, Chyuan; Lei, Yen-Ping

    2014-01-01

    Abstract Epidemiologic studies have reported increased incidence, prevalence and acuity of periodontitis in adults with diabetes and some have also suggested that treating periodontal disease may improve glycemic control in diabetic patients. This meta-analysis was conducted to evaluate the effects of different periodontal therapies on metabolic control in patients with type 2 diabetes mellitus (T2DM) and periodontal disease. We searched the Medline, EMBASE and Cochrane Library (Central) data...

  3. The relation between awareness of personal resources and metabolic control in children and adolescents with type 1 diabetes.

    Science.gov (United States)

    Blicke, Maren; Körner, Ulrike; Nixon, Patricia; Salgin, Burak; Meissner, Thomas; Pollok, Bettina

    2015-09-01

    The study aims to elucidate whether awareness of personal resources, such as positive attributions and beliefs or social support, affects metabolic control in children and adolescents with type 1 diabetes. In addition, it will be determined to what extent metabolic control is influenced by concordance between children and parents regarding awareness of resources and the parents' ability to adopt their children's perspective. Also, the children's wishes particularly in relation to their illness will be investigated, as well as the kind of advice they would offer to fellow patients. Seventy-eight children/adolescents with type 1 diabetes completed the Essen Resource Inventory for Children and Adolescents including personal, social, structural, and migration-specific resources. In addition, children/adolescents and their parents completed a systemic-oriented, diabetes-specific resource questionnaire in order to explore the parents' ability to adopt their children's perspective. Resources such as body awareness and open-minded attitude to the disease were associated with metabolic control. Particularly, resources associated to a migration background were found to be inversely correlated with hemoglobin A1c (HbA1c) value. Moreover, it was shown that the parents' ability to adopt their children's perspective was associated with improved metabolic control. Children advising fellow patients to accept the disease showed the best HbA1c value. This data identified specific modifiable factors related to metabolic control that can be addressed during counseling of pediatric patients. Also the parents' ability for adopting their child's perspective was identified as a relevant factor which should be considered during clinical counseling of young type 1 diabetes patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. 三相H桥级联静止同步补偿器的控制策略%Control Scheme of Three-phase H-bridge Cascaded STATCOM

    Institute of Scientific and Technical Information of China (English)

    江道灼; 张振华

    2011-01-01

    Since mathematic model of STATCOM is coupling and nonlinear, it is difficult to decouple active and reac- tive power. Another difficult point is voltage balancing control of dc side capacitors caused by H-bridge cascaded to- pology. Consequently, the exact feedback linearization control law is derived to accomplish the linearization of STATCOM model and to realize dec0upled control of active and reactive power, and the model can be changed into two independent first-order linear system. Sliding mode control method is used to design the controller, which can solve the difficulties in adjusting parameters of traditional PI controller and to improve the robustness of the control- ler. The voltage balance of capacitors is realized based on the analysis of the single H bridge module and nearest level modulation A STATCOM model is established in the Matlab/Simulink. The results of numerical simulation show that the established model and designed controller are effective, The active and reactive power can be adjusted inde- pendently. The voltages of capacitors can be balanced well, and the system has good dynamic response which is bet- ter than the traditional PI controller, and also has robustness.%三相H桥级联静止同步补偿器(STATCOM)可以解决配电网冲击性、不对称负载造成的动态电能质量问题,也具有多电平、易扩展的特点,而静止同步补偿器数学模型是一个强耦合、非线性系统,存在有功无功解耦难的问题,H桥级联的拓扑又使得电容电压平衡控制成为难点。针对有功无功耦合问题,通过引入精确反馈线性化方法实现完全解耦,系统降阶为两个独立的一阶线性系统,并引入指数趋近律设计完成滑模控制器,克服了传统比例积分(PI)控制器参数整定困难、鲁棒性不佳的问题。针对电容电压平衡问题,通过分析单个H桥模块的工作模态,结合最近电

  5. Association of metabolic gene polymorphisms with tobacco consumption in healthy controls.

    NARCIS (Netherlands)

    Smits, K.M.; Benhamou, S.; Garte, S.; Weijenberg, M.P.; Alamanos, Y.; Ambrosone, C.; Autrup, H.; Autrup, J.L.; Baranova, H.; Bathum, L.; Boffetta, P.; Bouchardy, C.; Brockmoller, J.; Butkiewicz, D.; Cascorbi, I.; Clapper, M.L.; Coutelle, C.; Daly, A.; Muzi, G.; Dolzan, V.; Duzhak, T.G.; Farker, K.; Golka, K.; Haugen, A.; Hein, D.W.; Hildesheim, A.; Hirvonen, A.; Hsieh, L.L.; Ingelman-Sundberg, M.; Kalina, I.; Kang, D.; Katoh, T.; Kihara, M.; Ono-Kihara, M.; Kim, H.L.; Kiyohara, C.; Kremers, P.; Lazarus, P.; Marchand, L. le; Lechner, M.C.; London, S.; Manni, J.J.; Maugard, C.M.; Morgan, G.J.; Morita, S.; Nazar-Stewart, V.; Kristensen, V.N.; Oda, Y.; Parl, F.F.; Peters, W.H.M.; Rannug, A.; Rebbeck, T.; Pinto, L.F.; Risch, A.; Romkes, M.; Salagovic, J.; Schoket, B.; Seidegard, J.; Shields, P.G.; Sim, E.; Sinnett, D.; Strange, R.C.; Stucker, I.; Sugimura, H.; To-Figueras, J.; Vineis, P.; Yu, M.C.; Zheng, W.; Pedotti, P.; Taioli, E.

    2004-01-01

    Polymorphisms in genes that encode for metabolic enzymes have been associated with variations in enzyme activity between individuals. Such variations could be associated with differences in individual exposure to carcinogens that are metabolized by these genes. In this study, we examine the associat

  6. Control of insulin secretion by cytochrome C and calcium signaling in islets with impaired metabolism.

    Science.gov (United States)

    Rountree, Austin M; Neal, Adam S; Lisowski, Mark; Rizzo, Norma; Radtke, Jared; White, Sarah; Luciani, Dan S; Kim, Francis; Hampe, Christiane S; Sweet, Ian R

    2014-07-01

    The aim of the study was to assess the relative control of insulin secretion rate (ISR) by calcium influx and signaling from cytochrome c in islets where, as in diabetes, the metabolic pathways are impaired. This was achieved either by culturing isolated islets at low (3 mm) glucose or by fasting rats prior to the isolation of the islets. Culture in low glucose greatly reduced the glucose response of cytochrome c reduction and translocation and ISR, but did not affect the response to the mitochondrial fuel α-ketoisocaproate. Unexpectedly, glucose-stimulated calcium influx was only slightly reduced in low glucose-cultured islets and was not responsible for the impairment in glucose-stimulated ISR. A glucokinase activator acutely restored cytochrome c reduction and translocation and ISR, independent of effects on calcium influx. Islets from fasted rats had reduced ISR and cytochrome c reduction in response to both glucose and α-ketoisocaproate despite normal responses of calcium. Our data are consistent with the scenario where cytochrome c reduction and translocation are essential signals in the stimulation of ISR, the loss of which can result in impaired ISR even when calcium response is normal.

  7. Salvaging diabetic foot through debridement, pressure alleviation, metabolic control, and antibiotics.

    Science.gov (United States)

    Cabeza de Vaca, Francisco G; Macias, Alejandro E; Ramirez, Welsy A; Munoz, Juan M; Alvarez, Jose A; Mosqueda, Juan L; Medina, Humberto; Sifuentes-Osornio, Jose

    2010-01-01

    There is a fatalist perception of diabetic foot because the argument of "small-vessel disease" prevails. This is the report of a cohort study of patients facing a formal recommendation for major foot amputation to assess how many can be saved with a conventional treatment, defined as debridement, pressure alleviation, metabolic control, and antibiotics. The primary efficacy measurement was the salvage of the limb at the follow-up visit between 25 and 35 days after the first consultation. The secondary efficacy measurement was the subsequent epithelization of the ulcerative lesions, following patients for up to 270 days. The cohort consisted of 105 type 2 diabetic patients; 87 (83%) had severe lesions. A total of 71 patients (68%) required hospitalization. By the intention-to-treat analysis, 89 patients (85%) avoided major amputation. A total of 88 patients were evaluated for complete epithelization, reaching median success by day 120. Overall, 51 patients (49%) underwent minor amputations. It was concluded that there is a high rate of unnecessary major foot amputations, because a diabetic foot can be salvaged across the continuum of severity when patients receive care in a multidisciplinary wound clinic. © 2010 by the Wound Healing Society.

  8. Improvement of glucaric acid production in E. coli via dynamic control of metabolic fluxes

    Directory of Open Access Journals (Sweden)

    Irene M. Brockman Reizman

    2015-12-01

    Full Text Available D-glucaric acid can be used as a building block for biopolymers as well as in the formulation of detergents and corrosion inhibitors. A biosynthetic route for production in Escherichia coli has been developed (Moon et al., 2009, but previous work with the glucaric acid pathway has indicated that competition with endogenous metabolism may limit carbon flux into the pathway. Our group has recently developed an E. coli strain where phosphofructokinase (Pfk activity can be dynamically controlled and demonstrated its use for improving yields and titers of the glucaric acid precursor myo-inositol on glucose minimal medium. In this work, we have explored the further applicability of this strain for glucaric acid production in a supplemented medium more relevant for scale-up studies, both under batch conditions and with glucose feeding via in situ enzymatic starch hydrolysis. It was found that glucaric acid titers could be improved by up to 42% with appropriately timed knockdown of Pfk activity during glucose feeding. The glucose feeding protocol could also be used for reduction of acetate production in the wild type and modified E. coli strains.

  9. Pterostilbene on metabolic parameters: a randomized, double-blind, and placebo-controlled trial.

    Science.gov (United States)

    Riche, Daniel M; Riche, Krista D; Blackshear, Chad T; McEwen, Corey L; Sherman, Justin J; Wofford, Marion R; Griswold, Michael E

    2014-01-01

    Introduction. The purpose of this trial was to evaluate the effect of pterostilbene on metabolic parameters. Methods. A prospective, randomized, double-blind, and placebo-controlled study that enrolled 80 patients with a total cholesterol ≥200 mg/dL and/or LDL ≥ 100 mg/dL. Subjects were divided into four groups: (1) pterostilbene 125 mg twice daily; (2) pterostilbene 50 mg twice daily; (3) pterostilbene 50 mg + grape extract (GE) 100 mg twice daily; (4) matching placebo twice daily for 6-8 weeks. Endpoints included lipids, blood pressure, and weight. Linear mixed models were used to examine and compare changes in parameters over time. Models were adjusted for age, gender, and race. Results. LDL increased with pterostilbene monotherapy (17.1 mg/dL; P = 0.001) which was not seen with GE combination (P = 0.47). Presence of a baseline cholesterol medication appeared to attenuate LDL effects. Both systolic (-7.8 mmHg; P < 0.01) and diastolic blood pressure (-7.3 mmHg; P < 0.001) were reduced with high dose pterostilbene. Patients not on cholesterol medication (n = 51) exhibited minor weight loss with pterostilbene (-0.62 kg/m(2); P = 0.012). Conclusion. Pterostilbene increases LDL and reduces blood pressure in adults. This trial is registered with Clinicaltrials.gov NCT01267227.

  10. Pterostilbene on Metabolic Parameters: A Randomized, Double-Blind, and Placebo-Controlled Trial

    Directory of Open Access Journals (Sweden)

    Daniel M. Riche

    2014-01-01

    Full Text Available Introduction. The purpose of this trial was to evaluate the effect of pterostilbene on metabolic parameters. Methods. A prospective, randomized, double-blind, and placebo-controlled study that enrolled 80 patients with a total cholesterol ≥200 mg/dL and/or LDL≥100 mg/dL. Subjects were divided into four groups: (1 pterostilbene 125 mg twice daily; (2 pterostilbene 50 mg twice daily; (3 pterostilbene 50 mg + grape extract (GE 100 mg twice daily; (4 matching placebo twice daily for 6–8 weeks. Endpoints included lipids, blood pressure, and weight. Linear mixed models were used to examine and compare changes in parameters over time. Models were adjusted for age, gender, and race. Results. LDL increased with pterostilbene monotherapy (17.1 mg/dL; P=0.001 which was not seen with GE combination (P=0.47. Presence of a baseline cholesterol medication appeared to attenuate LDL effects. Both systolic (−7.8 mmHg; P<0.01 and diastolic blood pressure (−7.3 mmHg; P<0.001 were reduced with high dose pterostilbene. Patients not on cholesterol medication (n=51 exhibited minor weight loss with pterostilbene (−0.62 kg/m2; P=0.012. Conclusion. Pterostilbene increases LDL and reduces blood pressure in adults. This trial is registered with Clinicaltrials.gov NCT01267227.

  11. Numerical study of improving aerodynamic performance of low solidity LPT cascade through increasing trailing edge thickness

    Science.gov (United States)

    Li, Chao; Yan, Peigang; Wang, Xiangfeng; Han, Wanjin; Wang, Qingchao

    2016-08-01

    This paper presents a new idea to reduce the solidity of low-pressure turbine (LPT) blade cascades, while remain the structural integrity of LPT blade. Aerodynamic performance of a low solidity LPT cascade was improved by increasing blade trailing edge thickness (TET). The solidity of the LPT cascade blade can be reduced by about 12.5% through increasing the TET of the blade without a significant drop in energy efficiency. For the low solidity LPT cascade, increasing the TET can decrease energy loss by 23.30% and increase the flow turning angle by 1.86% for Reynolds number (Re) of 25,000 and freestream turbulence intensities (FSTI) of 2.35%. The flow control mechanism governing behavior around the trailing edge of an LPT cascade is also presented. The results show that appropriate TET is important for the optimal design of high-lift load LPT blade cascades.

  12. Treatment patterns and risk factor control in patients with and without metabolic syndrome in cardiac rehabilitation

    Directory of Open Access Journals (Sweden)

    Gitt A

    2012-04-01

    Full Text Available Anselm Gitt1, Christina Jannowitz2, Marthin Karoff3, Barbara Karmann2, Martin Horack1, Heinz Völler4,51Institut für Herzinfarktforschung an der Universität Heidelberg, Ludwigshafen,2Medical Affairs, MSD Sharp and Dohme GmbH, Haar, 3Klinik Königsfeld der Deutschen Rentenversicherung Westfalen in Ennepetal (NRW, Klinik der Universität Witten-Herdecke, 4Kardiologie, Klinik am See, Rüdersdorf, 5Center of Rehabilitation Research, University Potsdam, GermanyAim: Metabolic syndrome (MetS is a clustering of factors that are associated with increased cardiovascular risk. We aimed to investigate the proportion of patients with MetS in patients undergoing cardiac rehabilitation (CR, and to describe differences between patients with MetS compared to those without MetS with regard to (1 patient characteristics including demographics, risk factors, and comorbidities, (2 risk factor management including drug treatment, and (3 control status of risk factors at entry to CR and discharge from CR.Methods: Post-hoc analysis of data from 27,904 inpatients (Transparency Registry to Objectify Guideline-Oriented Risk Factor Management registry that underwent a CR period of about 3 weeks were analyzed descriptively in total and compared by their MetS status.Results: In the total cohort, mean age was 64.3 years, (71.7% male, with no major differences between groups. Patients had been referred after a ST elevation of myocardial infarction event in 41.1% of cases, non-ST elevation of myocardial infarction in 21.8%, or angina pectoris in 16.7%. They had received a percutaneous coronary intervention in 55.1% and bypass surgery (coronary artery bypass graft in 39.5%. Patients with MetS (n = 15,819 compared to those without MetS (n = 12,085 were less frequently males, and in terms of cardiac interventions, more often received coronary artery bypass surgery. Overall, statin use increased from 79.9% at entry to 95.0% at discharge (MetS: 79.7% to 95.2%. Patients with Met

  13. CASCADE: Introducing AI into CBT.

    Science.gov (United States)

    Hendley, R. J.; Jurascheck, N.

    1992-01-01

    Discusses changes in training requirements of commerce and industry in the United Kingdom and describes a project, CASCADE, that was developed to investigate and implement the introduction of artificial intelligence (AI) techniques into computer-based training (CBT). An overview of pilot projects in higher education settings is provided. (eight…

  14. Unsteady transonic flow in cascades

    Science.gov (United States)

    Surampudi, S. P.; Adamczyk, J. J.

    1984-01-01

    There is a need for methods to predict the unsteady air loads associated with flutter of turbomachinery blading at transonic speeds. The results of such an analysis in which the steady relative flow approaching a cascade of thin airfoils is assumed to be transonic, irrotational, and isentropic is presented. The blades in the cascade are allowed to undergo a small amplitude harmonic oscillation which generates a small unsteady flow superimposed on the existing steady flow. The blades are assumed to oscillate with a prescribed motion of constant amplitude and interblade phase angle. The equations of motion are obtained by linearizing about a uniform flow the inviscid nonheat conducting continuity and momentum equations. The resulting equations are solved by employing the Weiner Hopf technique. The solution yields the unsteady aerodynamic forces acting on the cascade at Mach number equal to 1. Making use of an unsteady transonic similarity law, these results are compared with the results obtained from linear unsteady subsonic and supersonic cascade theories. A parametric study is conducted to find the effects of reduced frequency, solidity, stagger angle, and position of pitching axis on the flutter.

  15. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.;

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene...

  16. Coordinations between gene modules control the operation of plant amino acid metabolic networks

    Directory of Open Access Journals (Sweden)

    Galili Gad

    2009-01-01

    Full Text Available Abstract Background Being sessile organisms, plants should adjust their metabolism to dynamic changes in their environment. Such adjustments need particular coordination in branched metabolic networks in which a given metabolite can be converted into multiple other metabolites via different enzymatic chains. In the present report, we developed a novel "Gene Coordination" bioinformatics approach and use it to elucidate adjustable transcriptional interactions of two branched amino acid metabolic networks in plants in response to environmental stresses, using publicly available microarray results. Results Using our "Gene Coordination" approach, we have identified in Arabidopsis plants two oppositely regulated groups of "highly coordinated" genes within the branched Asp-family network of Arabidopsis plants, which metabolizes the amino acids Lys, Met, Thr, Ile and Gly, as well as a single group of "highly coordinated" genes within the branched aromatic amino acid metabolic network, which metabolizes the amino acids Trp, Phe and Tyr. These genes possess highly coordinated adjustable negative and positive expression responses to various stress cues, which apparently regulate adjustable metabolic shifts between competing branches of these networks. We also provide evidence implying that these highly coordinated genes are central to impose intra- and inter-network interactions between the Asp-family and aromatic amino acid metabolic networks as well as differential system interactions with other growth promoting and stress-associated genome-wide genes. Conclusion Our novel Gene Coordination elucidates that branched amino acid metabolic networks in plants are regulated by specific groups of highly coordinated genes that possess adjustable intra-network, inter-network and genome-wide transcriptional interactions. We also hypothesize that such transcriptional interactions enable regulatory metabolic adjustments needed for adaptation to the stresses.

  17. L-carnitine ameliorated fasting-induced fatigue, hunger, and metabolic abnormalities in patients with metabolic syndrome: a randomized controlled study

    OpenAIRE

    Zhang, Jun-Jie; Wu, Zhi-bing; Cai, You-jin; Ke, Bin; Huang, Ying-juan; Qiu, Chao-ping; Yang, Yu-bing; Shi, Lan-Ying; QIN, JIAN

    2014-01-01

    Background The present study aimed to determine that whether L-carnitine infusion could ameliorate fasting-induced adverse effects and improve outcomes. Method In this 7-day, randomized, single-blind, placebo-controlled, pilot study, 15 metabolic syndrome (MetS) patients (11/4 F/M; age 46.9 ± 9.14 years; body mass index [BMI] 28.2 ± 1.8 kg/m2) were in the L-carnitine group (LC) and 15 (10/5 F/M; age 46.8 ± 10.9 years; BMI 27.1 ± 2.3 kg/m2) were in the control group (CT). All participants unde...

  18. Integration of a complex regulatory cascade involving the SirA/BarA and Csr global regulatory systems that controls expression of the Salmonella SPI-1 and SPI-2 virulence regulons through HilD.

    Science.gov (United States)

    Martínez, Luary C; Yakhnin, Helen; Camacho, Martha I; Georgellis, Dimitris; Babitzke, Paul; Puente, José L; Bustamante, Víctor H

    2011-06-01

    Salmonella pathogenicity islands 1 and 2 (SPI-1 and SPI-2) play key roles in the pathogenesis of Salmonella enterica. Previously, we showed that when Salmonella grows in Luria-Bertani medium, HilD, encoded in SPI-1, first induces the expression of hilA, located in SPI-1, and subsequently of the ssrAB operon, located in SPI-2. These genes code for HilA and the SsrA/B two-component system, the positive regulators of the SPI-1 and SPI-2 regulons respectively. In this study, we demonstrate that CsrA, a global regulatory RNA binding protein, post-transcriptionally regulates hilD expression by directly binding near the Shine-Dalgarno and translation initiation codon sequences of the hilD mRNA, preventing its translation and leading to its accelerated turnover. Negative regulation is counteracted by the global SirA/BarA two-component system, which directly activates the expression of CsrB and CsrC, two non-coding regulatory RNAs that sequester CsrA, thereby preventing it from binding to its target mRNAs. Our results illustrate the integration of global and specific regulators into a multifactorial regulatory cascade controlling the expression of virulence genes acquired by horizontal transfer events.

  19. Autonomous cascaded PV system

    OpenAIRE

    2011-01-01

    This paper proposes multi-level PV system; three PV generators each coupled to a buck cell. Each PV-generator-buckconverter channel is controlled such that maximum power is captured independently under different irradiation and temperature levels. The system operation under normal/abnormal conditions is investigated by thoroughly mathematical and simulation work. Peer Reviewed

  20. Cascade Support Vector Machines with Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Oliver Kramer

    2015-01-01

    Full Text Available Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as preprocessing results in a significant speedup, often without loss of classifier accuracies, while considering the high-dimensional pendants of the low-dimensional support vectors in each new cascade level. We analyze and compare various instantiations of dimensionality reduction preprocessing and cascade SVMs with principal component analysis, locally linear embedding, and isometric mapping. The experimental analysis on various artificial and real-world benchmark problems includes various cascade specific parameters like intermediate training set sizes and dimensionalities.

  1. Cascaded resonant bridge converters

    Science.gov (United States)

    Stuart, Thomas A. (Inventor)

    1989-01-01

    A converter for converting a low voltage direct current power source to a higher voltage, high frequency alternating current output for use in an electrical system where it is desired to use low weight cables and other circuit elements. The converter has a first stage series resonant (Schwarz) converter which converts the direct current power source to an alternating current by means of switching elements that are operated by a variable frequency voltage regulator, a transformer to step up the voltage of the alternating current, and a rectifier bridge to convert the alternating current to a direct current first stage output. The converter further has a second stage series resonant (Schwarz) converter which is connected in series to the first stage converter to receive its direct current output and convert it to a second stage high frequency alternating current output by means of switching elements that are operated by a fixed frequency oscillator. The voltage of the second stage output is controlled at a relatively constant value by controlling the first stage output voltage, which is accomplished by controlling the frequency of the first stage variable frequency voltage controller in response to second stage voltage. Fault tolerance in the event of a load short circuit is provided by making the operation of the first stage variable frequency voltage controller responsive to first and second stage current limiting devices. The second stage output is connected to a rectifier bridge whose output is connected to the input of the second stage to provide good regulation of output voltage wave form at low system loads.

  2. Large-scaled metabolic profiling of human dermal fibroblasts derived from pseudoxanthoma elasticum patients and healthy controls.

    Directory of Open Access Journals (Sweden)

    Patricia Kuzaj

    Full Text Available Mutations in the ABC transporter ABCC6 were recently identified as cause of Pseudoxanthoma elasticum (PXE, a rare genetic disorder characterized by progressive mineralization of elastic fibers. We used an untargeted metabolic approach to identify biochemical differences between human dermal fibroblasts from healthy controls and PXE patients in an attempt to find a link between ABCC6 deficiency, cellular metabolic alterations and disease pathogenesis. 358 compounds were identified by mass spectrometry covering lipids, amino acids, peptides, carbohydrates, nucleotides, vitamins and cofactors, xenobiotics and energy metabolites. We found substantial differences in glycerophospholipid composition, leucine dipeptides, and polypeptides as well as alterations in pantothenate and guanine metabolism to be significantly associated with PXE pathogenesis. These findings can be linked to extracellular matrix remodeling and increased oxidative stress, which reflect characteristic hallmarks of PXE. Our study could facilitate a better understanding of biochemical pathways involved in soft tissue mineralization.

  3. Hypovitaminosis D in type 2 diabetes: relation with features of the metabolic syndrome and glycemic control.

    Science.gov (United States)

    Miñambres, Inka; Sánchez-Quesada, Jose Luis; Vinagre, Irene; Sánchez-Hernández, Joan; Urgell, Eulalia; de Leiva, Alberto; Pérez, Antonio

    2015-01-01

    To assess the association of hypovitaminosis D with clinical and biochemical characteristics of type 2 diabetic patients and to determine the effect of glycemic control optimization on 25-hydroxyvitamin D (25(OH)D) concentrations. Cross-sectional study of 63 patients with type 2 diabetes (mean age 60 ± 9.8 years, 69.8% men). Twenty of the 63 patients were also studied before and after glycemic control optimization. Mean 25(OH)D concentrations were 63.64 ± 25.51 nmol/L and 74.6% of patients had hypovitaminosis D. Compared with patients with vitamin D sufficiency, patients with hypovitaminosis D had higher prevalence of overweight or obesity (72.3% versus 37.5%; p = 0.012) and higher VLDL cholesterol (VLDL-c) (0.71 (0.24-3.59) versus 0.45 (0.13-1.6) mmol/L; p = 0.011) and C-reactive protein (3.28 (0.36-17.69) versus 1.87 (0.18-17.47) mg/L; p = 0.033) concentrations. The composition of HDL particles also differed in both groups, with higher relative content of triglycerides and lower of cholesterol in patients with hypovitaminosis D. After adjustment for age, seasonality and BMI, differences remained significant for VLDL-c and triglyceride content of HDL. No differences were found regarding other diabetes characteristics. Improvement of glycemic control (HbA1c 9.4 (7.6-14.8) versus 7.3 (6.2-8.7)%; p = 0.000) was accompanied by a decrease in 25(OH)D concentrations (72.7 ± 33.3 to 59.0 ± 21.0 nmol/L; p = 0.035). Correlation analysis revealed that changes in 25(OH)D concentrations were negatively associated to changes in HbA1c (r - 0.482; p = 0.032). Hypovitaminosis D is associated with features of the metabolic syndrome in type 2 diabetes and improvement of glycemic control decreases 25(OH)D concentrations.

  4. Robust sliding mode control of PMSM based on cascaded sliding mode observers%级联式滑模观测器的永磁同步电机鲁棒滑模控制

    Institute of Scientific and Technical Information of China (English)

    侯利民; 王怀震; 李勇; 张化光

    2016-01-01

    提出一种基于无速度传感器运行的永磁同步电机非线性控制方法。为了有效地估计转速和位置信息,构造一种新颖的级联式滑模速度观测器,以解决传统滑模观测采用低通滤波器的相位延迟问题。利用前级电流滑模观测器得到反电动势,后级反电动势滑模观测器获取转速和位置信息,利用李亚普诺夫理论进行稳定性分析。针对速度控制,提出利用带扩张状态观测器的滑模速度控制器取代PI调节器的方式提高系统的鲁棒性。仿真结果验证了所提出方法的有效性。%A nonlinear control method for the permanent magnet synchronous motor(PMSM) based on a speed sensorless is proposed. A novel cascaded sliding mode speed observer is proposed to estimate the speed and rotor position, to overcome the time delay caused by the low-pass filter. A front current sliding mode observer can estimate the electromotive force(EMF) of the motor in the axis, a back EMF sliding mode observer can estimate the speed and rotor position, and the Lyapunov theory is used to prove the stability of the algorithm. For the speed control problem, a robust sliding mode control with the extended state observer(ESO) is designed to improve the robust performance of system. The simulation results show the effectiveness of the proposed method.

  5. Does Telephone Follow-Up and Education Affect Self-Care and Metabolic Control in Diabetic Patients?

    Science.gov (United States)

    Aytekin Kanadli, Keriman; Ovayolu, Nimet; Ovayolu, Özlem

    2016-01-01

    The major goal of diabetes control is to assist patients to perform self-care and metabolic control. One possible way to achieve this goal is education and regular monitoring of patients by telephone. Thus, the present study was conducted with the aim of investigating the impact of education and telephone follow-up on self-care and metabolic control in diabetic patients. This experimental study was conducted at a hospital in the Central Anatolia region of Turkey, with 88 diabetic patients including 44 intervention subjects and 44 control subjects. After an initial discussion, patients in the intervention group received education and telephone follow-up for 3 months. Required approvals were obtained before initiation of the study. Data were collected using a questionnaire form and the Diabetes Self-Care Scale. The Diabetes Self-Care Scale scores ranged between 140 and 210, where higher scores indicated increased self-care activities of patients. At the end of the study, the self-care score was found to increase from 61.3 ± 10.9 to 89.9 ± 12.3 in the intervention group (P self-care scores and had a positive impact on metabolic control variables. In light of these findings, we suggest that education and tele-health home monitoring may be provided on a continuous basis to help patients sustain self-care behaviors that they have adopted during the study period.

  6. Generation of large fifth-order nonlinear phase shifts by use of lossless χ(2) cascaded nonlinear processes

    Institute of Scientific and Technical Information of China (English)

    XU Guang; QIAN Liejia; WANG Tao; FAN Dianyuan; LI Fuming

    2004-01-01

    It is shown that the cascaded fifth-order nonlinear phase shifts will increase with energy loss in the cascaded processes. Essentially different from the multi-photon absorption accompanied with inherent material nonlinearities, the loss of fundamental wave in a cascaded process is controllable and suppressible. By introducing difference frequencies generated from the reaction between the fundamental and its second harmonic after the cascaded processes, the fundamental wave can be free of energy loss, while the large cascaded fifth-order nonlinear phase shift is maintained.

  7. Cascaded Bragg scattering in fiber optics.

    Science.gov (United States)

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

    We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

  8. Relationship between chronic periodontitis and metabolic syndrome: a case-control study

    Directory of Open Access Journals (Sweden)

    Manovijay Balagangadharan

    2015-05-01

    Results: The results of the present study showed that the periodontal condition of group one patients were poor compared to group two patients. The periodontal conditioned worsened with an increase in the metabolic components. Conclusion: Based on the results of our study, it can be concluded that that periodontitis and metabolic syndrome were confounding the systemic effects of each other. Dentists should counsel their patients regarding the health hazards of metabolic syndrome and periodontitis and motivate them to maintain good oral hygiene and follow healthy life-style. [Int J Res Med Sci 2015; 3(5.000: 1257-1261

  9. Nutritional Ketosis Affects Metabolism and Behavior in Sprague-Dawley Rats in Both Control and Chronic Stress Environments

    Directory of Open Access Journals (Sweden)

    Milene L. Brownlow

    2017-05-01

    Full Text Available Nutritional ketosis may enhance cerebral energy metabolism and has received increased interest as a way to improve or preserve performance and resilience. Most studies to date have focused on metabolic or neurological disorders while anecdotal evidence suggests that ketosis may enhance performance in the absence of underlying dysfunction. Moreover, decreased availability of glucose in the brain following stressful events is associated with impaired cognition, suggesting the need for more efficient energy sources. We tested the hypotheses that ketosis induced by endogenous or exogenous ketones could: (a augment cognitive outcomes in healthy subjects; and (b prevent stress-induced detriments in cognitive parameters. Adult, male, Sprague Dawley rats were used to investigate metabolic and behavioral outcomes in 3 dietary conditions: ketogenic (KD, ketone supplemented (KS, or NIH-31 control diet in both control or chronic stress conditions. Acute administration of exogenous ketones resulted in reduction in blood glucose and sustained ketosis. Chronic experiments showed that in control conditions, only KD resulted in pronounced metabolic alterations and improved performance in the novel object recognition test. The hypothalamic-pituitary-adrenal (HPA axis response revealed that KD-fed rats maintained peripheral ketosis despite increases in glucose whereas no diet effects were observed in ACTH or CORT levels. Both KD and KS-fed rats decreased escape latencies on the third day of water maze, whereas only KD prevented stress-induced deficits on the last testing day and improved probe test performance. Stress-induced decrease in hippocampal levels of β-hydroxybutyrate was attenuated in KD group while both KD and KS prevented stress effects on BDNF levels. Mitochondrial enzymes associated with ketogenesis were increased in both KD and KS hippocampal samples and both endothelial and neuronal glucose transporters were affected by stress but only in the

  10. Turbulence Amplification with Incidence at the Leading Edge of a Compressor Cascade

    Directory of Open Access Journals (Sweden)

    Garth V. Hobson

    1999-01-01

    Full Text Available Detailed measurements, with a two-component laser-Doppler velocimeter and a thermal anemometer were made near the suction surface leading edge of controlled-diffusion airfoils in cascade. The Reynolds number was near 700,000, Mach number equal to 0.25, and freestream turbulence was at 1.5% ahead of the cascade.

  11. Metabolic syndrome, its components and risk of age-related cataract extraction: a case-control study in Italy.

    Science.gov (United States)

    Galeone, Carlotta; Petracci, Elisabetta; Pelucchi, Claudio; Zucchetto, Antonella; La Vecchia, Carlo; Tavani, Alessandra

    2010-05-01

    We sought to explore the relationship between age-related cataract extraction and the metabolic syndrome or its various components separately and in various combinations in an Italian case-control study. A total of 761 cases and 1,522 controls in hospital for acute, non-neoplastic, non-ophthalmologic, non-metabolic diseases were interviewed between 1991 and 2003. Odds ratios (ORs), and their 95% confidence intervals (CIs), were computed from multiple logistic regression models, conditioned on sex, age, and study center and adjusted for education and smoking. The ORs were 1.41 for a history of central obesity, 1.42 for hypertension, 1.25 for hyperlipidemia, and 1.16 for diabetes. Patients with the metabolic syndrome (defined as the simultaneous presence of central obesity and at least two other factors among hypertension, hyperlipidemia, diabetes) had an increased risk of cataract, with an OR of 2.01 (95% CI: 1.43-2.83). The ORs were 1.75 for the presence of any of two components and 2.50 for three to four components, with a linear trend in risk. This study indicates that the metabolic syndrome, its components, and their combination are associated with an increased risk of cataract extraction in this Italian population. 2010 Elsevier Inc. All rights reserved.

  12. Comparative aspects of the endotoxin- and cytokine-induced endocrine cascade influencing neuroendocrine control of growth and reproduction in farm animals.

    Science.gov (United States)

    Whitlock, B K; Daniel, J A; Wilborn, R R; Elsasser, T H; Carroll, J A; Sartin, J L

    2008-07-01

    Disease in animals is a well-known inhibitor of growth and reproduction. Earlier studies were initiated to determine the effects of endotoxin on pituitary hormone secretion. These studies found that in sheep, growth hormone (GH) concentration was elevated, whereas insulin-like growth factor-I (IGF-I) was inhibited, as was luteinizing hormone (LH). Examination of the site of action of endotoxin in sheep determined that somatotropes expressed the endotoxin receptor (CD14) and that both endotoxin and interleukin-I beta activated GH secretion directly from the pituitary. In the face of elevated GH, there is a reduction of IGF-I in all species examined. As GH cannot activate IGF-I release during disease, there appears to be a downregulation of GH signalling at the liver, perhaps related to altered nitration of Janus kinase (JAK). In contrast to GH downregulation, LH release is inhibited at the level of the hypothalamus. New insights have been gained in determining the mechanisms by which disease perturbs growth and reproduction, particularly with regard to nitration of critical control pathways, with this perhaps serving as a novel mechanism central to lipopolysaccharide suppression of all signalling pathways. This pathway-based analysis is critical to the developing novel strategies to reverse the detrimental effect of disease on animal production.

  13. Control of Nutrient Stress-Induced Metabolic Reprogramming by PKCζ in Tumorigenesis

    Science.gov (United States)

    Ma, Li; Tao, Yongzhen; Duran, Angeles; Llado, Victoria; Galvez, Anita; Barger, Jennifer F.; Castilla, Elias A.; Chen, Jing; Yajima, Tomoko; Porollo, Aleksey; Medvedovic, Mario; Brill, Laurence M.; Plas, David R.; Riedl, Stefan J.; Leitges, Michael; Diaz-Meco, Maria T.; Richardson, Adam D.; Moscat, Jorge

    2013-01-01

    SUMMARY Tumor cells have high-energetic and anabolic needs and are known to adapt their metabolism to be able to survive and keep proliferating under conditions of nutrient stress. We show that PKCζ deficiency promotes the plasticity necessary for cancer cells to reprogram their metabolism to utilize glutamine through the serine biosynthetic pathway in the absence of glucose. PKCζ represses the expression of two key enzymes of the pathway, PHGDH and PSAT1, and phosphorylates PHGDH at key residues to inhibit its enzymatic activity. Interestingly, the loss of PKCζ in mice results in enhanced intestinal tumorigenesis and increased levels of these two metabolic enzymes, whereas patients with low levels of PKCζ have a poor prognosis. Furthermore, PKCζ and caspase-3 activities are correlated with PHGDH levels in human intestinal tumors. Taken together, this demonstrates that PKCζ is a critical metabolic tumor suppressor in mouse and human cancer. PMID:23374352

  14. Metabolic Heat Regenerated Temperature Swing Adsorption for CO2, Thermal and Humidity Control Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is proposed for a Portable Life Support System to remove and reject heat and carbon dioxide...

  15. Continuous monitoring reveals multiple controls on ecosystem metabolism in a suburban stream.

    Science.gov (United States)

    Ecosystem metabolism is an important mechanism for nutrient retention in streams, yet few high studies have investigated temporal patterns in gross primary production (GPP) and ecosystem respiration (ER) using high frequency measurements. This is a potentially important oversig...

  16. Early life origins of metabolic disease: Developmental programming of hypothalamic pathways controlling energy homeostasis.

    Science.gov (United States)

    Dearden, Laura; Ozanne, Susan E

    2015-10-01

    A wealth of animal and human studies demonstrate that perinatal exposure to adverse metabolic conditions - be it maternal obesity, diabetes or under-nutrition - results in predisposition of offspring to develop obesity later in life. This mechanism is a contributing factor to the exponential rise in obesity rates. Increased weight gain in offspring exposed to maternal obesity is usually associated with hyperphagia, implicating altered central regulation of energy homeostasis as an underlying cause. Perinatal development of the hypothalamus (a brain region key to metabolic regulation) is plastic and sensitive to metabolic signals during this critical time window. Recent research in non-human primate and rodent models has demonstrated that exposure to adverse maternal environments impairs the development of hypothalamic structure and consequently function, potentially underpinning metabolic phenotypes in later life. This review summarizes our current knowledge of how adverse perinatal environments program hypothalamic development and explores the mechanisms that could mediate these effects.

  17. Activities of genes controlling sphingolipid metabolism in human fibroblasts treated with flavonoids

    OpenAIRE

    Moskot, Marta; Jakóbkiewicz-Banecka, Joanna; Smolińska, Elwira; Banecki, Bogdan; Węgrzyn, Grzegorz; Gabig-Cimińska, Magdalena

    2015-01-01

    Natural flavonoids such as genistein, kaempferol and daidzein were previously found to be able to reduce efficiency of glycosaminoglycan synthesis in cells of patients suffering from mucopolysaccharidoses, inherited metabolic diseases with often brain disease symptoms. This feature was employed to test these compounds as potential drugs for treatment other neuronopathic lysosomal storage disorders, in which errors in sphingolipid metabolism occur. In this report, on the basis of DNA microarra...

  18. The post-transcriptional regulatory system CSR controls the balance of metabolic pools in upper glycolysis of Escherichia coli.

    Science.gov (United States)

    Morin, Manon; Ropers, Delphine; Letisse, Fabien; Laguerre, Sandrine; Portais, Jean-Charles; Cocaign-Bousquet, Muriel; Enjalbert, Brice

    2016-05-01

    Metabolic control in Escherichia coli is a complex process involving multilevel regulatory systems but the involvement of post-transcriptional regulation is uncertain. The post-transcriptional factor CsrA is stated as being the only regulator essential for the use of glycolytic substrates. A dozen enzymes in the central carbon metabolism (CCM) have been reported as potentially controlled by CsrA, but its impact on the CCM functioning has not been demonstrated. Here, a multiscale analysis was performed in a wild-type strain and its isogenic mutant attenuated for CsrA (including growth parameters, gene expression levels, metabolite pools, abundance of enzymes and fluxes). Data integration and regulation analysis showed a coordinated control of the expression of glycolytic enzymes. This also revealed the imbalance of metabolite pools in the csrA mutant upper glycolysis, before the phosphofructokinase PfkA step. This imbalance is associated with a glucose-phosphate stress. Restoring PfkA activity in the csrA mutant strain suppressed this stress and increased the mutant growth rate on glucose. Thus, the carbon storage regulator system is essential for the effective functioning of the upper glycolysis mainly through its control of PfkA. This work demonstrates the pivotal role of post-transcriptional regulation to shape the carbon metabolism.

  19. Adolescents with type 1 diabetes: parental perceptions of child health and family functioning and their relationship to adolescent metabolic control.

    Science.gov (United States)

    Moore, Susan M; Hackworth, Naomi J; Hamilton, Victoria E; Northam, Elisabeth P; Cameron, Fergus J

    2013-03-22

    Adolescents with Type 1 diabetes (T1D) show less effective metabolic control than other age groups, partly because of biological changes beyond their control and partly because in this period of developmental transition, psychosocial factors can militate against young people upholding their lifestyle and medical regimens. Parents have an important role to play in supporting adolescents to self-manage their disease, but resultant family tensions can be high. In this study, we aimed to assess family functioning and adolescent behaviour/ adjustment and examine the relationships between these parent-reported variables and adolescent metabolic control (HbA1c), self-reported health and diabetes self-care. A sample of 76 parents of Australian adolescents with T1D completed the Child Health Questionnaire -Parent form. Their adolescent child with T1D provided their HbA1c level from their most recent clinic visit, their self-reported general health, and completed a measure of diabetes self-care. Parent-reported family conflict was high, as was disease impact on family dynamics and parental stress. Higher HbA1c (poorer metabolic control) and less adequate adolescent self-care were associated with lower levels of family functioning, more adolescent behavioural difficulties and poorer adolescent mental health. The implication of these findings was discussed in relation to needs for information and support among Australian families with an adolescent with T1D, acknowledging the important dimension of family functioning and relationships in adolescent chronic disease management.

  20. Soft sensor control of metabolic fluxes in a recombinant Escherichia coli fed-batch cultivation producing green fluorescence protein.

    Science.gov (United States)

    Gustavsson, Robert; Mandenius, Carl-Fredrik

    2013-10-01

    A soft sensor approach is described for controlling metabolic overflow from mixed-acid fermentation and glucose overflow metabolism in a fed-batch cultivation for production of recombinant green fluorescence protein (GFP) in Escherichia coli. The hardware part of the sensor consisted of a near-infrared in situ probe that monitored the E. coli biomass and an HPLC analyzer equipped with a filtration unit that measured the overflow metabolites. The computational part of the soft sensor used basic kinetic equations and summations for estimation of specific rates and total metabolite concentrations. Two control strategies for media feeding of the fed-batch cultivation were evaluated: (1) controlling the specific rates of overflow metabolism and mixed-acid fermentation metabolites at a fixed pre-set target values, and (2) controlling the concentration of the sum of these metabolites at a set level. The results indicate that the latter strategy was more efficient for maintaining a high titer and low variability of the produced recombinant GFP protein.