Science.gov

Sample records for active power factor

  1. Single-Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Chinthavali, Madhu Sudhan; Onar, Omer C; Miller, John M; Tang, Lixin

    2013-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance. To understand the power flow through the system this paper presents a novel approach to the system model and the impact of different control parameters on the load power. The implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation is also discussed.

  2. SiC MOSFET Based Single Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    SciTech Connect

    Onar, Omer C; Tang, Lixin; Chinthavali, Madhu Sudhan; Campbell, Steven L; Miller , John M.

    2014-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges the utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance due to variable parameters such as battery state-of-charge, coupling factor, and coil misalignment. This paper presents the implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation. The proposed SiC MOSFET based single phase active front end rectifier with PFC resulted in >97% efficiency at 137mm air-gap and >95% efficiency at 160mm air-gap.

  3. Industrial Power Factor Analysis Guidebook.

    SciTech Connect

    Electrotek Concepts.

    1995-03-01

    Power factor is a way of measuring the percentage of reactive power in an electrical system. Reactive power represents wasted energy--electricity that does no useful work because the electrical current is out of phase with the voltage. Reactive power is used by inductive loads (such as, motors, transformers, fluorescent lights, arc welders and induction furnaces) to sustain their magnetic fields. Electric systems with many motors exhibit low power factors, increased conductor and transformer losses, and lower voltages. Utilities must supply both active and reactive power and compensate for these losses. Power factor can be improved by the addition of shunt capacitors. Capacitors act in opposition to inductive loads, thereby minimizing the reactive power required to serve them. In raising the power factor, shunt capacitors release energy to the system, reduce system losses, and ultimately decrease power costs. Improving system power factor can reduce reactive and active power losses for both industry and utilities through the addition of shunt capacitors. This Guide Book gives electric utility technical staff, industrial end-users, consultants and BPA employees a step-by-step method for evaluating the cost effectiveness of installing power factor correction capacitors in an industrial plant.

  4. Control of Dual-Opposed Stirling Convertors with Active Power Factor Correction Controllers

    NASA Technical Reports Server (NTRS)

    Regan, Timothy F.; Lewandowski, Edward J.; Schreiber, Jeffrey G.

    2006-01-01

    When using recently-developed active power factor correction (APFC) controllers in power systems comprised of dual-opposed free-piston Stirling convertors, a variety of configurations of the convertors and controller(s) can be considered, with configuration ultimately selected based on benefits of efficiency, reliability, and robust operation. The configuration must not only achieve stable control of the two convertors, but also synchronize and regulate motion of the pistons to minimize net dynamic forces. The NASA Glenn Research Center (GRC) System Dynamic Model (SDM) was used to study ten configurations of dual-opposed convertor systems. These configurations considered one controller with the alternators connected in series or in parallel, and two controllers with the alternators not connected (isolated). For the configurations where the alternators were not connected, several different approaches were evaluated to synchronize the two convertors. In addition, two thermodynamic configurations were considered: two convertors with isolated working spaces and convertors with a shared expansion space. Of the ten configurations studied, stable operating modes were found for four. Three of those four had a common expansion space. One stable configuration was found for the dual-opposed convertors with separate working spaces. That configuration required isochronous control of both convertors, and two APFC controllers were used to accomplish this. A frequency/phase control loop was necessary to allow each APFC controller to synchronize its associated convertor with a common frequency.

  5. Control of Dual-Opposed Stirling Convertors with Active Power Factor Correction Controllers

    NASA Technical Reports Server (NTRS)

    Regan, Timothy F.; Lewandowski, Edward J.; Schreiber, Jeffrey G.

    2007-01-01

    When using recently-developed active power factor correction (APFC) controllers in power systems comprised of dual-opposed free-piston Stirling convertors, a variety of configurations of the convertors and controller(s) can be considered, with configuration ultimately selected based on benefits of efficiency, reliability, and robust operation. The configuration must not only achieve stable control of the two convertors, but also synchronize and regulate motion of the pistons to minimize net dynamic forces. The NASA Glenn Research Center (GRC) System Dynamic Model (SDM) was used to study ten configurations of dual-opposed convertor systems. These configurations considered one controller with the alternators connected in series or in parallel, and two controllers with the alternators not connected (isolated). For the configurations where the alternators were not connected, several different approaches were evaluated to synchronize the two convertors. In addition, two thermodynamic configurations were considered: two convertors with isolated working spaces and convertors with a shared expansion space. Of the ten configurations studied, stable operating modes were found for four. Three of those four had a common expansion space. One stable configuration was found for the dual-opposed convertors with separate working spaces. That configuration required isochronous control of both convertors, and two APFC controllers were used to accomplish this. A frequency/phase control loop was necessary to allow each APFC controller to synchronize its associated convertor with a common frequency.

  6. Fatigue in repeated-sprint exercise is related to muscle power factors and reduced neuromuscular activity.

    PubMed

    Mendez-Villanueva, Alberto; Hamer, Peter; Bishop, David

    2008-07-01

    The purpose of this study was (1) to determine the relationship between each individual's anaerobic power reserve (APR) [i.e., the difference between the maximum anaerobic (Pana) and aerobic power (Paer)] and fatigability during repeated-sprint exercise and (2) to examine the acute effects of repeated sprints on neuromuscular activity, as evidenced by changes in the surface electromyogram (EMG) signals. Eight healthy males carried out tests to determine Pana (defined as the highest power output attained during a 6-s cycling sprint), Paer (defined as the highest power output achieved during a progressive, discontinuous cycling test to failure) and a repeated cycling sprint test (10 x 6-s max sprints with 30 s rest). Peak power output (PPO) and mean power output (MPO) were calculated for each maximal 6-s cycling bout. Root mean square (RMS) was utilized to quantify EMG activity from the vastus lateralis (VL) muscle of the right leg. Over the ten sprints, PPO and MPO decreased by 24.6 and 28.3% from the maximal value (i.e., sprint 1), respectively. Fatigue index during repeated sprints was significantly correlated with APR (R = 0.87; P < 0.05). RMS values decreased over the ten sprints by 14.6% (+/-6.3%). There was a strong linear relationship (R2 = 0.97; P < 0.05) between the changes in MPO and EMG RMS from the vastus lateralis muscle during the ten sprints. The individual advantage in fatigue-resistance when performing a repeated sprint task was related with a lower anaerobic power reserve. Additionally, a suboptimal net motor unit activity might also impair the ability to repeatedly generate maximum power outputs.

  7. Unity power factor converter

    NASA Technical Reports Server (NTRS)

    Wester, Gene W. (Inventor)

    1980-01-01

    A unity power factor converter capable of effecting either inversion (dc-to-dc) or rectification (ac-to-dc), and capable of providing bilateral power control from a DC source (or load) through an AC transmission line to a DC load (or source) for power flow in either direction, is comprised of comparators for comparing the AC current i with an AC signal i.sub.ref (or its phase inversion) derived from the AC ports to generate control signals to operate a switch control circuit for high speed switching to shape the AC current waveform to a sine waveform, and synchronize it in phase and frequency with the AC voltage at the AC ports, by selectively switching the connections to a series inductor as required to increase or decrease the current i.

  8. Unity power factor switching regulator

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor)

    1983-01-01

    A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

  9. Commercialization of the power factor controller

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The purpose of the Motor Power Controller, also known as the Power Factor Controller, is to improve power factor and reduce power dissipation in induction motors operating below full load. These purposes were studied and tested in detail. The Motor Power Controller is capable of raising power factors from 0.2 to 0.8 and results in energy savings. It was found that many motors, in their present operating applications, are classified as unstable. The electronic nature of the controller vs. the electrical nature of the motor, compound this problem due to the differences in response time of the two devices. Many tests were successfully completed, the most indicating greater savings than anticipated. Also, there was an effect on efficiency which was not included in the calculations.

  10. Activation of human factor IX (Christmas factor).

    PubMed

    Di Scipio, R G; Kurachi, K; Davie, E W

    1978-06-01

    Human Factor IX (Christmas factor) is a single-chain plasma glycoprotein (mol wt 57,000) that participates in the middle phase of the intrinsic pathway of blood coagulation. It is present in plasma as a zymogen and is converted to a serine protease, Factor IXabeta, by Factor XIa (activated plasma thromboplastin antecedent) in the presence of calcium ions. In the activation reaction, two internal peptide bonds are hydrolyzed in Factor IX. These cleavages occur at a specific arginyl-alanine peptide bond and a specific arginyl-valine peptide bond. This results in the release of an activation peptide (mol wt approximately equal to 11,000) from the internal region of the precursor molecule and the generation of Factor IXabeta (mol wt approximately equal to 46,000). Factor IXabeta is composed of a light chain (mol wt approximately equal to 18,000) and a heavy chain (mol wt approximately equal to 28,000), and these chains are held together by a disulfide bond(s). The light chain originates from the amino terminal portion of the precursor molecule and has an amino terminal sequence of Tyr-Asn-Ser-Gly-Lys. The heavy chain originates from the carboxyl terminal region of the precursor molecule and contains an amino terminal sequence of Val-Val-Gly-Gly-Glu. The heavy chain of Factor IXabeta also contains the active site sequence of Phe-Cys-Ala-Gly-Phe-His-Glu-Gly-Arg-Asp-Ser-Cys-Gln-Gly-Asp-SER-Gly-Gly-Pro. The active site serine residue is shown in capital letters. Factor IX is also converted to Factor IXaalpha by a protease from Russell's viper venom. This activation reaction, however, occurs in a single step and involves only the cleavage of the internal arginyl-valine peptide bond. Human Factor IXabeta was inhibited by human antithrombin III by the formation of a one-to-one complex of enzyme and inhibitor. In this reaction, the inhibitor was tightly bound to the heavy chain of the enzyme. These data indicate that the mechanism of activation of human Factor IX and its

  11. Active Power Control from Wind Power (Presentation)

    SciTech Connect

    Ela, E.; Brooks, D.

    2011-04-01

    In order to keep the electricity grid stable and the lights on, the power system relies on certain responses from its generating fleet. This presentation evaluates the potential for wind turbines and wind power plants to provide these services and assist the grid during critical times.

  12. Power-Factor Controllers: How Safe?

    NASA Technical Reports Server (NTRS)

    Long, K.; Christian, W.; Kovacik, J.; Grazyk, T.

    1985-01-01

    Potential safety problems with power-factor controllers (PFC's) evaluated. Based on study of PFCs in use with appliances, report recommends measures to prevent consumers from misapplying these energy saving devices. Device used on such appliances as refrigerators, sewing machines, pumps, hair dryers, and food processors. When misused, they fail to save energy and may cause damage.

  13. Power factor corrector on insulated metal substrate

    SciTech Connect

    Aime, G.; Barbaroux, J.; Ferrieux, J.P. |

    1995-12-31

    This paper describes a high density Power Factor Correction converter for AC-DC applications with sinusoidal input current. After analysis of the thermal behavior of several types of Insulated-Metal Substrates, study and design have been implemented on IMS with Surface Mount components. Experimental results are discussed for a 1 kW prototype operating at 100 kHz.

  14. Economic comparison of power factor correction by capacitors and high power factor/high-efficiency motors

    SciTech Connect

    Slack, K.D.; Capehart, B.L.

    1998-12-01

    The traditional approach to power factor correction in a facility is to add capacitors to individual loads such as motors and fluorescent lighting circuits, to add a capacitor bank with switching to a major distribution panel, or to add a capacitor bank with switching to the power input panel from the utility lines. Recently it has been shown that careful selection of high-efficiency motors for a facility can result in new motors with a significantly higher power factor than the motors they replaced. This article compares and discusses the cost-effectiveness of installing capacitors on individual motors with the cost-effectiveness of installing high-efficiency, high power factor motors.

  15. Nanoparticles with an Enhanced Power Factor

    NASA Astrophysics Data System (ADS)

    Yang, Heng Quan; Miao, Lei; Zhang, Ming; Ohno, Kaoru; Zhou, Jian Hua; Gu, Hui; Shen, Yang; Lin, Hong

    2014-06-01

    Nanostructured thermoelectric (TE) materials, for example Sb2Te3, PbTe, and SiGe-based semiconductors, have excellent thermoelectric transport properties and are promising candidates for next-generation TE commercial application. However, it is a challenge to synthesize the corresponding pure nanocrystals with controlled size by low-temperature wet-chemical reaction. Herein, we report an alternative versatile solution-based method for synthesis of plate-like Sb2Te3 nanoparticles in a flask using SbCl3 and Te powders as raw materials, EDTA-Na2 as complexing agent, and NaBH4 as reducing agent in the solvent (distilled water). To investigate their thermoelectric transport properties, the obtained powders were cold compacted into cuboid prisms then annealed under a protective N2 atmosphere. The results showed that both the electrical conductivity ( σ) and the power factor ( S 2 σ) can be enhanced by improving the purity of the products and by increasing the annealing temperature. The highest power factor was 2.04 μW cm-1 K-2 at 140°C and electrical conductivity remained in the range 5-10 × 103 S m-1. This work provides a simple and economic approach to preparation of large quantities of nanostructured Sb2Te3 with excellent TE performance, making it a fascinating candidate for commercialization of cooling devices.

  16. Control circuit maintains unity power factor of reactive load

    NASA Technical Reports Server (NTRS)

    Kramer, M.; Martinage, L. H.

    1966-01-01

    Circuit including feedback control elements automatically corrects the power factor of a reactive load. It maintains power supply efficiency where negative load reactance changes and varies by providing corrective error signals to the control windings of a power supply transformer.

  17. Power factor control system for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1981-01-01

    A power control circuit for an induction motor is disclosed in which a servo loop is used to control power input by controlling the power factor of motor operation. The power factor is measured by summing the voltage and current derived square wave signals.

  18. Active Power Controls from Wind Power: Bridging the Gaps

    SciTech Connect

    Ela, E.; Gevorgian, V.; Fleming, P.; Zhang, Y. C.; Singh, M.; Muljadi, E.; Scholbrook, A.; Aho, J.; Buckspan, A.; Pao, L.; Singhvi, V.; Tuohy, A.; Pourbeik, P.; Brooks, D.; Bhatt, N.

    2014-01-01

    This paper details a comprehensive study undertaken by the National Renewable Energy Laboratory, Electric Power Research Institute, and the University of Colorado to understand how the contribution of wind power providing active power control (APC) can benefit the total power system economics, increase revenue streams, improve the reliability and security of the power system, and provide superior and efficient response while reducing any structural and loading impacts that may reduce the life of the wind turbine or its components. The study includes power system simulations, control simulations, and actual field tests using turbines at NREL's National Wind Technology Center (NWTC). The study focuses on synthetic inertial control, primary frequency control, and automatic generation control, and analyzes timeframes ranging from milliseconds to minutes to the lifetime of wind turbines, locational scope ranging from components of turbines to large wind plants to entire synchronous interconnections, and additional topics ranging from economics to power system engineering to control design.

  19. Organizational factors and nuclear power plant safety

    SciTech Connect

    Haber, S.B.

    1995-12-31

    There are many organizations in our society that depend on human performance to avoid incidents involving significant adverse consequences. As our culture and technology have become more sophisticated, the management of risk on a broad basis has become more and more critical. The safe operation of military facilities, chemical plants, airlines, and mass transit, to name a few, are substantially dependent on the performance of the organizations that operate those facilities. The nuclear power industry has, within the past 15 years, increased the attention given to the influence of human performance in the safe operation of nuclear power plants (NPP). While NPPs have been designed through engineering disciplines to intercept and mitigate events that could cause adverse consequences, it has been clear from various safety-related incidents that human performance also plays a dominant role in preventing accidents. Initial efforts following the 1979 Three Mile Island incident focused primarily on ergonomic factors (e.g., the best design of control rooms for maximum performance). Greater attention was subsequently directed towards cognitive processes involved in the use of NPP decision support systems and decision making in general, personnel functions such as selection systems, and the influence of work scheduling and planning on employees` performance. Although each of these approaches has contributed to increasing the safety of NPPS, during the last few years, there has been a growing awareness that particular attention must be paid to how organizational processes affect NPP personnel performance, and thus, plant safety. The direct importance of organizational factors on safety performance in the NPP has been well-documented in the reports on the Three Mile Island and Chernobyl accidents as well as numerous other events, especially as evaluated by the U.S. Nuclear Regulatory Commission (NRC).

  20. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, William B.; Graham, Robert A.; Morosin, Bruno

    1988-01-01

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolytes rendering the electrolyte electrochemically active.

  1. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, W.B.; Graham, R.A.; Morosin, B.

    1987-04-20

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolyte rendering the electrolyte electrochemically active. 2 figs.

  2. Shock-activated electrochemical power supplies

    DOEpatents

    Benedick, W.B.; Graham, R.A.; Morosin, B.

    1988-11-08

    A shock-activated electrochemical power supply is provided which is initiated extremely rapidly and which has a long shelf life. Electrochemical power supplies of this invention are initiated much faster than conventional thermal batteries. Power supplies of this invention comprise an inactive electrolyte and means for generating a high-pressure shock wave such that the shock wave is propagated through the electrolytes rendering the electrolyte electrochemically active. 2 figs.

  3. Power to Production: Activity Guide.

    ERIC Educational Resources Information Center

    Massachusetts Univ., Lowell. Tsongas Industrial History Center.

    This field trip program consists of a 90-minute interpretive tour and a 90-minute hands-on workshop. The tour and workshop explore the role of water power in the Industrial Revolution. On the tour, students discover firsthand the unique resources of Lowell, Massachusetts, and the Park, while the workshop brings these historic resources to life as…

  4. Simulation of a Wireless Power Transfer System for Electric Vehicles with Power Factor Correction

    SciTech Connect

    Pickelsimer, Michael C; Tolbert, Leon M; Ozpineci, Burak; Miller, John M

    2012-01-01

    Wireless power transfer has been a popular topic of recent research. Most research has been done to address the limitations of coil-to-coil efficiency. However, little has been done to address the problem associated with the low input power factor with which the systems operate. This paper details the steps taken to analyze a wireless power transfer system from the view of the power grid under a variety of loading conditions with and without power factor correction.

  5. Factor Analysis of Various Anaerobic Power Tests.

    ERIC Educational Resources Information Center

    Manning, James M.; And Others

    A study investigated the relationship between selected anthropometric variables and of numerous anaerobic power tests with measures obtained on an isokinetic dynamometer. Thirty-one male college students performed several anaerobic power tests, including: the vertical jump using the Lewis formula; the Margaria-Kalamen stair climb test; the Wingate…

  6. A Student Activity on Visual Resolving Power

    ERIC Educational Resources Information Center

    Warren, T. H.; Henriksen, P. N.; Ramsier, R. D.

    2003-01-01

    We present a simple activity in which students measure the resolving power of their eyes. The approach can be used at various levels of sophistication with students having a wide variety of skills and scientific training. We discuss our experiences using this activity with a class of non-science majors as well as with a group of pre-engineering…

  7. Public opinion factors regarding nuclear power

    SciTech Connect

    Benson, B.

    1991-12-31

    This paper is an effort to identify, as comprehensively as possible, public concerns about nuclear power, and to assess, where possible, the relative importance of these concerns as they relate to government regulation of and policy towards nuclear power. It is based on some two dozen in-depth interviews with key communicators representing the nuclear power industry, the environmental community, and government, as well as on the parallel efforts in our research project: (1) review of federal court case law, (2) a selective examination of the Nuclear Regulatory Commission (NRC) administrative process, and (3) the preceding George Mason University research project in this series. The paper synthesizes our findings about public attitudes towards nuclear power as expressed through federal court case law, NRC administrative law, public opinion surveys, and direct personal interviews. In so doing, we describe the public opinion environment in which the nuclear regulatory process must operate. Our premise is that public opinion ultimately underlies the approaches government agencies take towards regulating nuclear power, and that, to the degree that the nuclear power industry`s practices are aligned with public opinion, a more favorable regulatory climate is possible.

  8. Public opinion factors regarding nuclear power

    SciTech Connect

    Benson, B.

    1991-01-01

    This paper is an effort to identify, as comprehensively as possible, public concerns about nuclear power, and to assess, where possible, the relative importance of these concerns as they relate to government regulation of and policy towards nuclear power. It is based on some two dozen in-depth interviews with key communicators representing the nuclear power industry, the environmental community, and government, as well as on the parallel efforts in our research project: (1) review of federal court case law, (2) a selective examination of the Nuclear Regulatory Commission (NRC) administrative process, and (3) the preceding George Mason University research project in this series. The paper synthesizes our findings about public attitudes towards nuclear power as expressed through federal court case law, NRC administrative law, public opinion surveys, and direct personal interviews. In so doing, we describe the public opinion environment in which the nuclear regulatory process must operate. Our premise is that public opinion ultimately underlies the approaches government agencies take towards regulating nuclear power, and that, to the degree that the nuclear power industry's practices are aligned with public opinion, a more favorable regulatory climate is possible.

  9. Power factor control system for AC induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1977-01-01

    A power factor control system for use with ac induction motors was designed which samples lines voltage and current through the motor and decreases power input to the motor proportional to the detected phase displacement between current and voltage. This system provides, less power to the motor, as it is less loaded.

  10. Piezoelectric Power Requirements for Active Vibration Control

    NASA Technical Reports Server (NTRS)

    Brennan, Matthew C.; McGowan, Anna-Maria Rivas

    1997-01-01

    This paper presents a method for predicting the power consumption of piezoelectric actuators utilized for active vibration control. Analytical developments and experimental tests show that the maximum power required to control a structure using surface-bonded piezoelectric actuators is independent of the dynamics between the piezoelectric actuator and the host structure. The results demonstrate that for a perfectly-controlled system, the power consumption is a function of the quantity and type of piezoelectric actuators and the voltage and frequency of the control law output signal. Furthermore, as control effectiveness decreases, the power consumption of the piezoelectric actuators decreases. In addition, experimental results revealed a non-linear behavior in the material properties of piezoelectric actuators. The material non- linearity displayed a significant increase in capacitance with an increase in excitation voltage. Tests show that if the non-linearity of the capacitance was accounted for, a conservative estimate of the power can easily be determined.

  11. Powerful anti-tumor and anti-angiogenic activity of a new anti-vascular endothelial growth factor receptor 1 peptide in colorectal cancer models.

    PubMed

    Cicatiello, Valeria; Apicella, Ivana; Tudisco, Laura; Tarallo, Valeria; Formisano, Luigi; Sandomenico, Annamaria; Kim, Younghee; Bastos-Carvalho, Ana; Orlandi, Augusto; Ambati, Jayakrishna; Ruvo, Menotti; Bianco, Roberto; De Falco, Sandro

    2015-04-30

    To assess the therapeutic outcome of selective block of VEGFR1, we have evaluated the activity of a new specific antagonist of VEGFR1, named iVR1 (inhibitor of VEGFR1), in syngenic and xenograft colorectal cancer models, in an artificial model of metastatization, and in laser-induced choroid neovascularization. iVR1 inhibited tumor growth and neoangiogenesis in both models of colorectal cancer, with an extent similar to that of bevacizumab, a monoclonal antibody anti-VEGF-A. It potently inhibited VEGFR1 phosphorylation in vivo, determining a strong inhibition of the recruitment of monocyte-macrophages and of mural cells as confirmed, in vitro, by the ability to inhibit macrophages migration. iVR1 was able to synergize with irinotecan determining a shrinkage of tumors that became undetectable after three weeks of combined treatment. Such treatment induced a significant prolongation of survival similar to that observed with bevacizumab and irinotecan combination. iVR1 also fully prevented lung invasion by HCT-116 cells injected in mouse tail vein. Also, iVR1 impressively inhibited choroid neovascularization after a single intravitreal injection. Collectively, data showed the strong potential of iVR1 peptide as a new anti-tumor and anti-metastatic agent and demonstrate the high flexibility of VEGFR1 antagonists as therapeutic anti-angiogenic agents in different pathological contexts. PMID:25868854

  12. Active micromachines: Microfluidics powered by mesoscale turbulence.

    PubMed

    Thampi, Sumesh P; Doostmohammadi, Amin; Shendruk, Tyler N; Golestanian, Ramin; Yeomans, Julia M

    2016-07-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterized by mesoscale turbulence, which is the emergence of chaotic flow structures. By immersing an ordered array of symmetric rotors in an active fluid, we introduce a microfluidic system that exploits spontaneous symmetry breaking in mesoscale turbulence to generate work. The lattice of rotors self-organizes into a spin state where neighboring discs continuously rotate in permanent alternating directions due to combined hydrodynamic and elastic effects. Our virtual prototype demonstrates a new research direction for the design of micromachines powered by the nematohydrodynamic properties of active turbulence.

  13. Active micromachines: Microfluidics powered by mesoscale turbulence

    PubMed Central

    Thampi, Sumesh P.; Doostmohammadi, Amin; Shendruk, Tyler N.; Golestanian, Ramin; Yeomans, Julia M.

    2016-01-01

    Dense active matter, from bacterial suspensions and microtubule bundles driven by motor proteins to cellular monolayers and synthetic Janus particles, is characterized by mesoscale turbulence, which is the emergence of chaotic flow structures. By immersing an ordered array of symmetric rotors in an active fluid, we introduce a microfluidic system that exploits spontaneous symmetry breaking in mesoscale turbulence to generate work. The lattice of rotors self-organizes into a spin state where neighboring discs continuously rotate in permanent alternating directions due to combined hydrodynamic and elastic effects. Our virtual prototype demonstrates a new research direction for the design of micromachines powered by the nematohydrodynamic properties of active turbulence. PMID:27419229

  14. New hybrid active power filter for harmonic current suppression and reactive power compensation

    NASA Astrophysics Data System (ADS)

    Biricik, Samet; Cemal Ozerdem, Ozgur; Redif, Soydan; Sezai Dincer, Mustafa

    2016-08-01

    In the case of undistorted and balanced grid voltages, low ratio shunt active power filters (APFs) can give unity power factors and achieve current harmonic cancellation. However, this is not possible when source voltages are distorted and unbalanced. In this study, the cost-effective hybrid active power filter (HAPF) topology for satisfying the requirements of harmonic current suppression and non-active power compensation for industry is presented. An effective strategy is developed to observe the effect of the placement of power capacitors and LC filters with the shunt APF. A new method for alleviating the negative effects of a nonideal grid voltage is proposed that uses a self-tuning filter algorithm with instantaneous reactive power theory. The real-time control of the studied system was achieved with a field-programmable gate array (FPGA) architecture, which was developed using the OPAL-RT system. The performance result of the proposed HAPF system is tested and presented under nonideal supply voltage conditions.

  15. Monitoring Biological Activity at Geothermal Power Plants

    SciTech Connect

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  16. Statistical Performances of Resistive Active Power Splitter

    NASA Astrophysics Data System (ADS)

    Lalléchère, Sébastien; Ravelo, Blaise; Thakur, Atul

    2016-03-01

    In this paper, the synthesis and sensitivity analysis of an active power splitter (PWS) is proposed. It is based on the active cell composed of a Field Effect Transistor in cascade with shunted resistor at the input and the output (resistive amplifier topology). The PWS uncertainty versus resistance tolerances is suggested by using stochastic method. Furthermore, with the proposed topology, we can control easily the device gain while varying a resistance. This provides useful tool to analyse the statistical sensitivity of the system in uncertain environment.

  17. Tissue factor activity under flow.

    PubMed

    Diamond, Scott L

    2010-04-01

    Coagulation processes under flow conditions are fundamentally different when compared to whole blood clotting in a tube. Due to red blood cell migration toward the center of the vessel, platelet concentrations are elevated several-fold in the plasma layer near the wall or thrombus. Evaluation of platelet function, coagulation proteases, and pharmacological agents can utilize closed systems of constant volume that lack flow (eg. intracellular calcium measurement, automated calibrated thrombography) or include flow (eg. aggregometry or cone-and-plate viscometry). However, these laboratory approaches fail to recreate the fact that intravascular thrombosis is an open system where blood is continually flowing over a thrombotic site. In open systems, the rapid accumulation of platelets at a surface leads to platelet concentrations greatly exceeding those found in whole blood and the delivery/removal of species by convection may impact the efficacy of pharmacological agents. During a clotting event under flow, platelets can accumulate via adhesion receptors to concentrations that are 10 to 50-fold higher than that of platelet-rich plasma. Using controlled in vitro perfusions of whole blood, it is possible to determine the critical level of surface tissue factor needed to trigger full scale coagulation on collagen. Such in vitro perfusion systems also allow a determination of the potency of anti-platelet agents as a function of wall shear rate.

  18. Activation of factor X by rat hepatocytes

    SciTech Connect

    Willingham, A.K.; Matschiner, J.T.

    1986-05-01

    Synthesis and secretion of blood coagulation factor X was studied in hepatocytes prepared by perfusion of rat livers with collagenase. Hepatocytes were incubated in the presence of vitamin K and /sup 3/H-leucine for up to 4h at 37/sup 0/C. Factor X was isolated from the incubation medium by immunochemical techniques and analyzed by SDS-PAGE. The recovered /sup 3/H-labeled proteins migrated, after reduction of disulfides, as two polypeptide chains with apparent molecular weights (M/sub r/) of approximately 42,000 and 22,000 representing the heavy and light chains of factor X respectively. The apparent M/sub r/ of the heavy chain was about 10,000 daltons lighter than seen with the heavy chain of factor X isolated from rat plasma and was more characteristic of the heavy chain of factor Xa. When the levels of factor X secreted by hepatocytes were determined by clotting assays, activity was present as factor Xa. Also, when purified plasma factor X was added to incubations of hepatocytes (>95% parenchymal cells) the added factor X was rapidly converted to factor Xa. Plasma membranes prepared from isolated hepatocytes or from liver homogenates contained an enzyme that converted factor X to factor Xa in a calcium dependent reaction. The physiological significance of a factor X activating enzyme on hepatocyte plasma membranes is not clear.

  19. Ratchet transport powered by chiral active particles

    PubMed Central

    Ai, Bao-quan

    2016-01-01

    We numerically investigate the ratchet transport of mixtures of active and passive particles in a transversal asymmetric channel. A big passive particle is immersed in a ‘sea’ of active particles. Due to the chirality of active particles, the longitudinal directed transport is induced by the transversal asymmetry. For the active particles, the chirality completely determines the direction of the ratchet transport, the counterclockwise and clockwise particles move to the opposite directions and can be separated. However, for the passive particle, the transport behavior becomes complicated, the direction is determined by competitions among the chirality, the self-propulsion speed, and the packing fraction. Interestingly, within certain parameters, the passive particle moves to the left, while active particles move to the right. In addition, there exist optimal parameters (the chirality, the height of the barrier, the self-propulsion speed and the packing fraction) at which the rectified efficiency takes its maximal value. Our findings could be used for the experimental pursuit of the ratchet transport powered by chiral active particles. PMID:26795952

  20. Ratchet transport powered by chiral active particles.

    PubMed

    Ai, Bao-quan

    2016-01-01

    We numerically investigate the ratchet transport of mixtures of active and passive particles in a transversal asymmetric channel. A big passive particle is immersed in a 'sea' of active particles. Due to the chirality of active particles, the longitudinal directed transport is induced by the transversal asymmetry. For the active particles, the chirality completely determines the direction of the ratchet transport, the counterclockwise and clockwise particles move to the opposite directions and can be separated. However, for the passive particle, the transport behavior becomes complicated, the direction is determined by competitions among the chirality, the self-propulsion speed, and the packing fraction. Interestingly, within certain parameters, the passive particle moves to the left, while active particles move to the right. In addition, there exist optimal parameters (the chirality, the height of the barrier, the self-propulsion speed and the packing fraction) at which the rectified efficiency takes its maximal value. Our findings could be used for the experimental pursuit of the ratchet transport powered by chiral active particles.

  1. Energy and power limits for microbial activity

    NASA Astrophysics Data System (ADS)

    LaRowe, D.; Amend, J.

    2014-12-01

    The goal of this presentation is to describe a quantitative framework for determining how energy limits microbial activity, biomass and, ultimately, biogeochemical processes. Although this model can be applied to any environment, its utility is demonstrated in marine sediments, which are an attractive test habitat because they encompass a broad spectrum of energy levels, varying amounts of biomass and are ubiquitous. The potential number of active microbial cells in Arkonas Basin (Baltic Sea) sediments are estimated as a function of depth by quantifying the amount of energy that is available to them and the rate at which it is supplied: power. The amount of power supplied per cubic centimeter of sediment is determined by calculating the Gibbs energy of fermentation and sulfate reduction in combination with the rate of particulate organic carbon, POC, degradation. The Reactive Continuum Model (Boudreau and Ruddick, 1991), RCM, is used to determine the rate at which POC is made available for microbial consumption. The RCM represents POC as containing a range of different types of organic compounds whose ability to be consumed by microorganisms varies as a function of the age of the sediment and on the distribution of compound types that were initially deposited. The sediment age model and RCM parameters determined by (Mogollon et al., 2012) are used. The power available for fermentation and sulfate reduction coupled to H2 and acetate oxidation varies from 10-8 W cm-3 at the sediment water interface to between 10-11 - 10-12 W cm-3 at 3.5 meters below the seafloor, mbsf. Using values of maintenance powers for each of these catabolic activities taken from the literature, the total number of active cells in these sediments similarly decreases from just less than 108 cell cm-3 at the SWI to 4.6 x 104 cells cm-3 at 3.5 mbsf. The number of moles of POC decreases from 2.6 x 10-5 to 9.5 x 10-6, also becoming more recalcitrant with depth. Boudreau, B. P. and Ruddick, B. R

  2. Active microring based tunable optical power splitters

    NASA Astrophysics Data System (ADS)

    Peter, Eldhose; Thomas, Arun; Dhawan, Anuj; Sarangi, Smruti R.

    2016-01-01

    In this paper we propose a set of novel tunable optical power splitters based on active microring resonators. They work by operating ring resonators in the transient zone between full resonance and off-resonance states for a specific wavelength. We can achieve different split ratios by either varying the bias voltage, or by selectively enabling a given resonator with a specific split ratio among an array of ring resonators. We take 500 ps to tune the resonator, which is at least 10× better that competing designs. Its split ratio varies from 0.4 to 1.8 for an applied voltage range of 0-5 V.

  3. [AHH activity and life environmental factors].

    PubMed

    Nagayama, J

    1987-04-01

    To investigate life environmental factors which affect aryl hydrocarbon hydroxylase (AHH) activity, basal and 3-methylcholanthrene(3-MC)-induced AHH activities were determined by the formation of 3-hydroxybenzo(a)pyrene in cultured lymphocytes obtained from 111 healthy male subjects who lived in Fukuoka Prefecture, Japan. Fold induction (3-MC-induced/basal) was calculated. Relationship between the absolute activities and the fold induction of AHH and life environmental factors was statistically examined. Study of simple correlation indicated the following: Basal AHH activity was positively correlated with age and habitual intake of drugs. Induced AHH activity was positively correlated with coffee intake, smoking and habitual intake of drugs. Fold induction was positively correlated with coffee intake and smoking, and negatively with age. Using multiple regression analysis, habitual intake of drugs showed positive relation to both basal and induced enzyme activity, and age showed positive relation to the basal activity and negative relation to the fold induction.

  4. Factors that affect the fatigue strength of power transmission shafting

    NASA Technical Reports Server (NTRS)

    Loewenthal, S. H.

    1984-01-01

    A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

  5. Gated Si nanowires for large thermoelectric power factors

    SciTech Connect

    Neophytou, Neophytos; Kosina, Hans

    2014-08-18

    We investigate the effect of electrostatic gating on the thermoelectric power factor of p-type Si nanowires (NWs) of up to 20 nm in diameter in the [100], [110], and [111] crystallographic transport orientations. We use atomistic tight-binding simulations for the calculation of the NW electronic structure, coupled to linearized Boltzmann transport equation for the calculation of the thermoelectric coefficients. We show that gated NW structures can provide ∼5× larger thermoelectric power factor compared to doped channels, attributed to their high hole phonon-limited mobility, as well as gating induced bandstructure modifications which further improve mobility. Despite the fact that gating shifts the charge carriers near the NW surface, surface roughness scattering is not strong enough to degrade the transport properties of the accumulated hole layer. The highest power factor is achieved for the [111] NW, followed by the [110], and finally by the [100] NW. As the NW diameter increases, the advantage of the gated channel is reduced. We show, however, that even at 20 nm diameters (the largest ones that we were able to simulate), a ∼3× higher power factor for gated channels is observed. Our simulations suggest that the advantage of gating could still be present in NWs with diameters of up to ∼40 nm.

  6. Thermopower and thermoelectric power factor of Zk parafermion quantum dots

    NASA Astrophysics Data System (ADS)

    Georgiev, Lachezar S.

    2015-10-01

    Using the conformal field theory approach to the thermoelectric characteristics of fractional quantum Hall states, previously developed in Georgiev (2015) [10], we show that the thermoelectric power factor of Coulomb-blockaded islands, realized by point contacts in Fabry-Pérot interferometers in the Zk parafermion Hall states, could give reliable signatures for distinguishing the topological orders of different quantum Hall states having identical electric properties. For example, while the conductance peak patterns in the Coulomb blockade regime for such states are practically indistinguishable for vn ≪vc even at finite temperature, where vn and vc are the Fermi velocities of the neutral and charged modes respectively, the power factors PT of the corresponding states are much more sensitive to the neutral modes. In particular, the smaller r =vn /vc the bigger the asymmetries in the power factor which combined with the thermal broadening of the conductance peaks due to the neutral modes' multiplicities could give us the ultimate tool to figure out which of the competing quantum Hall universality classes are indeed realized in the experiments. We give a complete description of the power factor profiles in the Z3 and Z4 parafermion states with arbitrary number of quasiparticles localized in the bulk which could be useful for comparison with the experiments.

  7. Single-stage electronic ballast with high-power factor

    NASA Astrophysics Data System (ADS)

    Park, Chun-Yoon; Kwon, Jung-Min; Kwon, Bong-Hwan

    2014-03-01

    This article proposes a single-stage electronic ballast circuit with high-power factor. The proposed circuit was derived by sharing the switches of the power factor correction (PFC) and the half-bridge LCC resonant inverter. This integration of switches forms the proposed single-stage electronic ballast, which provides an almost unity power factor and a ripple-free input current by using a coupled inductor without increasing the voltage stress. In addition, it realises zero-voltage-switching (ZVS) by employing the self-oscillation technique. The saturable transformer constituting the self-oscillating drive limits the lamp current and dominates the switching frequency of the ballast. Therefore, the proposed single-stage ballast has the advantage of high-power factor, high efficiency, low cost and high reliability. Steady-state analysis of the PFC and the half-bridge LCC resonant inverter are described. The results of experiments performed using a 30 W fluorescent lamp are also presented to confirm the performance of the proposed ballast.

  8. Potential Role of Activating Transcription Factor 5 during Osteogenesis.

    PubMed

    Vicari, Luisa; Calabrese, Giovanna; Forte, Stefano; Giuffrida, Raffaella; Colarossi, Cristina; Parrinello, Nunziatina Laura; Memeo, Lorenzo

    2016-01-01

    Human adipose-derived stem cells are an abundant population of stem cells readily isolated from human adipose tissue that can differentiate into connective tissue lineages including bone, cartilage, fat, and muscle. Activating transcription factor 5 is a transcription factor of the ATF/cAMP response element-binding protein (CREB) family. It is transcribed in two types of mRNAs (activating transcription factor 5 isoform 1 and activating transcription factor 5 isoform 2), encoding the same single 30-kDa protein. Although it is well demonstrated that it regulates the proliferation, differentiation, and apoptosis, little is known about its potential role in osteogenic differentiation. The aim of this study was to evaluate the expression levels of the two isoforms and protein during osteogenic differentiation of human adipose-derived stem cells. Our data indicate that activating transcription factor 5 is differentially expressed reaching a peak of expression at the stage of bone mineralization. These findings suggest that activating transcription factor 5 could play an interesting regulatory role during osteogenesis, which would provide a powerful tool to study bone physiology. PMID:26770207

  9. Wind Powering America FY07 Activities Summary

    SciTech Connect

    Not Available

    2008-02-01

    The Wind Powering America FY07 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 30 state wind working groups (welcoming Georgia and Wisconsin in 2007) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 140 members of national and state public and private sector organizations from 39 U.S. states and Canada attended the 6th Annual WPA All-States Summit in Los Angeles in June. WPA's emphasis remains on the rural agricultural sector, which stands to reap the significant economic development benefits of wind energy development. Additionally, WPA continues its program of outreach, education, and technical assistance to Native American communities, public power entities, and regulatory and legislative bodies.

  10. A Power Factor Corrected SMPS with Improved Power Quality for Welding Applications

    NASA Astrophysics Data System (ADS)

    Narula, Swati; Singh, Bhim; Bhuvaneswari, G.; Pandey, Rahul

    2015-04-01

    This paper presents the analysis, design and implementation of a power factor corrected Arc Welding Power Supply (AWPS) with a boost converter at the front end and three full-bridge (FB) converters connected in parallel at the load end. The modular arrangement of the FB converters offers several meritorious features like usage of power devices with comparatively lower voltage and current ratings, ease of power expandability, easy maintenance, etc. The boost converter operates in continuous conduction mode minimizing the input current ripple and leading to the lowest RMS current thereby improving the input power quality. Individual control loops are designed for each power stage. A dual loop control scheme is employed to incorporate over-current limit on the proposed AWPS which ensures excellent weld bead quality. The proposed AWPS is implemented to validate its performance over a wide range of line/load variations. Test results confirm its fast parametrical response to load and source voltage variations and over-current protection leading to improved welding performance and weld bead quality. The system is found to perform extremely well with very low input current THD and unity power factor, adhering to international power quality norms.

  11. Wind Powering America FY06 Activities Summary

    SciTech Connect

    Not Available

    2007-02-01

    The Wind Powering America FY06 Activities Summary reflects the accomplishments of our state wind working groups, our programs at the National Renewable Energy Laboratory, and our partner organizations. The national WPA team remains a leading force for moving wind energy forward in the United States. WPA continues to work with its national, regional, and state partners to communicate the opportunities and benefits of wind energy to a diverse set of stakeholders. WPA now has 29 state wind working groups (welcoming New Jersey, Indiana, Illinois, and Missouri in 2006) that form strategic alliances to communicate wind's benefits to the state stakeholders. More than 120 members of national and state public and private sector organizations from 34 states attended the 5th Annual WPA All-States Summit in Pittsburgh in June.

  12. Optically powered active sensing system for Internet Of Things

    NASA Astrophysics Data System (ADS)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  13. Economic Conditions and Factors Affecting New Nuclear Power Deployment

    SciTech Connect

    Harrison, Thomas J.

    2014-10-01

    This report documents work performed in support of the US Department of Energy Office of Nuclear Energy’s Advanced Small Modular Reactor (AdvSMR) program. The report presents information and results from economic analyses to describe current electricity market conditions and those key factors that may impact the deployment of AdvSMRs or any other new nuclear power plants. Thus, this report serves as a reference document for DOE as it moves forward with its plans to develop advanced reactors, including AdvSMRs. For the purpose of this analysis, information on electricity markets and nuclear power plant operating costs will be combined to examine the current state of the nuclear industry and the process required to successfully move forward with new nuclear power in general and AdvSMRs in particular. The current electricity market is generally unfavorable to new nuclear construction, especially in deregulated markets with heavy competition from natural gas and subsidized renewables. The successful and profitable operation of a nuclear power plant (or any power plant) requires the rate at which the electricity is sold to be sufficiently greater than the cost to operate. The wholesale rates in most US markets have settled into values that provide profits for most operating nuclear power plants but are too low to support the added cost of capital recovery for new nuclear construction. There is a strong geographic dependence on the wholesale rate, with some markets currently able to support new nuclear construction. However, there is also a strong geographic dependence on pronuclear public opinion; the areas where power prices are high tend to have unfavorable views on the construction of new nuclear power plants. The use of government-backed incentives, such as subsidies, can help provide a margin to help justify construction projects that otherwise may not seem viable. Similarly, low interest rates for the project will also add a positive margin to the economic

  14. Three-phase power factor controller with induced EMF sensing

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  15. Factors Associated with Evaluating Public Relations Activities.

    ERIC Educational Resources Information Center

    McElreath, Mark P.

    More than 150 public relations practitioners responded to a survey designed to identify and clarify factors associated with evaluative research in public relations. Responses indicated that (1) no more than half the practitioners formally evaluate their public relations activities on a regular basis; (2) the majority of evaluation is done…

  16. Personality Factors and Nuclear Power Plant Operators: Initial License Success

    NASA Astrophysics Data System (ADS)

    DeVita-Cochrane, Cynthia

    Commercial nuclear power utilities are under pressure to effectively recruit and retain licensed reactor operators in light of poor candidate training completion rates and recent candidate failures on the Nuclear Regulatory Commission (NRC) license exam. One candidate failure can cost a utility over $400,000, making the successful licensing of new operators a critical path to operational excellence. This study was designed to discover if the NEO-PI-3, a 5-factor measure of personality, could improve selection in nuclear utilities by identifying personality factors that predict license candidate success. Two large U.S. commercial nuclear power corporations provided potential participant contact information and candidate results on the 2014 NRC exam from their nuclear power units nation-wide. License candidates who participated (n = 75) completed the NEO-PI-3 personality test and results were compared to 3 outcomes on the NRC exam: written exam, simulated operating exam, and overall exam result. Significant correlations were found between several personality factors and both written and operating exam outcomes on the NRC exam. Further, a regression analysis indicated that personality factors, particularly Conscientiousness, predicted simulated operating exam scores. The results of this study may be used to support the use of the NEO-PI-3 to improve operator selection as an addition to the current selection protocol. Positive social change implications from this study include support for the use of a personality measure by utilities to improve their return-on-investment in candidates and by individual candidates to avoid career failures. The results of this study may also positively impact the public by supporting the safe and reliable operation of commercial nuclear power utilities in the United States.

  17. Spatial factors affecting statistical power in testing marine fauna displacement.

    PubMed

    Pérez Lapeña, B; Wijnberg, K M; Stein, A; Hulscher, S J M H

    2011-10-01

    Impacts of offshore wind farms on marine fauna are largely unknown. Therefore, one commonly adheres to the precautionary principle, which states that one shall take action to avoid potentially damaging impacts on marine ecosystems, even when full scientific certainty is lacking. We implement this principle by means of a statistical power analysis including spatial factors. Implementation is based on geostatistical simulations, accommodating for zero-inflation in species data. We investigate scenarios in which an impact assessment still has to be carried out. Our results show that the environmental conditions at the time of the survey is the most influential factor on power. This is followed by survey effort and species abundance in the reference situation. Spatial dependence in species numbers at local scales affects power, but its effect is smaller for the scenarios investigated. Our findings can be used to improve effectiveness of the economical investment for monitoring surveys. In addition, unnecessary extra survey effort, and related costs, can be avoided when spatial dependence in species abundance is present and no improvement on power is achieved.

  18. Activated human platelets induce factor XIIa-mediated contact activation.

    PubMed

    Bäck, Jennie; Sanchez, Javier; Elgue, Graciela; Ekdahl, Kristina Nilsson; Nilsson, Bo

    2010-01-01

    Earlier studies have shown that isolated platelets in buffer systems can promote activation of FXII or amplify contact activation, in the presence of a negatively charge substance or material. Still proof is lacking that FXII is activated by platelets in a more physiological environment. In this study we investigate if activated platelets can induce FXII-mediated contact activation and whether this activation affects clot formation in human blood. Human platelets were activated with a thrombin receptor-activating peptide, SFLLRN-amide, in platelet-rich plasma or in whole blood. FXIIa and FXIa in complex with preferentially antithrombin (AT) and to some extent C1-inhibitor (C1INH) were generated in response to TRAP stimulation. This contact activation was independent of surface-mediated contact activation, tissue factor pathway or thrombin. In clotting whole blood FXIIa-AT and FXIa-AT complexes were specifically formed, demonstrating that AT is a potent inhibitor of FXIIa and FXIa generated by platelet activation. Contact activation proteins were analyzed by flow cytometry and FXII, FXI, high-molecular weight kininogen, and prekallikrein were detected on activated platelets. Using chromogenic assays, enzymatic activity of platelet-associated FXIIa, FXIa, and kallikrein were demonstrated. Inhibition of FXIIa in non-anticoagulated blood also prolonged the clotting time. We conclude that platelet activation triggers FXII-mediated contact activation on the surface and in the vicinity of activated platelets. This leads specifically to generation of FXIIa-AT and FXIa-AT complexes, and contributes to clot formation. Activated platelets may thereby constitute an intravascular locus for contact activation, which may explain the recently reported importance of FXII in thrombus formation. PMID:19878657

  19. Direct charge radioisotope activation and power generation

    DOEpatents

    Lal, Amit; Li, Hui; Blanchard, James P.; Henderson, Douglass L.

    2002-01-01

    An activator has a base on which is mounted an elastically deformable micromechanical element that has a section that is free to be displaced toward the base. An absorber of radioactively emitted particles is formed on the base or the displaceable section of the deformable element and a source is formed on the other of the displaceable section or the base facing the absorber across a small gap. The radioactive source emits charged particles such as electrons, resulting in a buildup of charge on the absorber, drawing the absorber and source together and storing mechanical energy as the deformable element is bent. When the force between the absorber and the source is sufficient to bring the absorber into effective electrical contact with the source, discharge of the charge between the source and absorber allows the deformable element to spring back, releasing the mechanical energy stored in the element. An electrical generator such as a piezoelectric transducer may be secured to the deformable element to convert the released mechanical energy to electrical energy that can be used to provide power to electronic circuits.

  20. Agent-based power sharing scheme for active hybrid power sources

    NASA Astrophysics Data System (ADS)

    Jiang, Zhenhua

    The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

  1. Factor validation of an instrument measuring group power.

    PubMed

    Sieloff, Christina Leibold; Dunn, Karen

    2008-01-01

    Few publications have reported empirical findings regarding the measurement of nursing group power. This article reports the confirmatory factor analyses of the Sieloff-King Assessment of Group Power Within Organizations (SKAGPO) for instrument and middle-range theory development. Secondary analyses were conducted using cross-sectional data collected in 1999. The target population of the initial research was the chief nurse executives (CNEs) of all hospitals within the United States (including Alaska and Hawaii). A sample of 600 hospitals from across the United States was selected through a stratified random sampling process. A total of 350 executives comprised the final sample. Second-order confirmatory 8-factor analysis revealed factor loadings ranging from .43 to .89. The overall fit of the proposed model was: X2 = 1,360, df = 586, p < .00, GFI = .82, CFI = .86, and RMSEA = .06, indicating an acceptable fit with the data. Statistical support was found for the proposed model with the subsequent development of an alternate model that better fit the data. The study results indicated that the SKAGPO has acceptable psychometric properties.

  2. Factors driving wind power development in the United States

    SciTech Connect

    Bird, Lori A.; Parsons, Brian; Gagliano, Troy; Brown, Matthew H.; Wiser, Ryan H.; Bolinger, Mark

    2003-05-15

    In the United States, there has been substantial recent growth in wind energy generating capacity, with growth averaging 24 percent annually during the past five years. About 1,700 MW of wind energy capacity was installed in 2001, while another 410 MW became operational in 2002. This year (2003) shows promise of significant growth with more than 1,500 MW planned. With this growth, an increasing number of states are experiencing investment in wind energy projects. Wind installations currently exist in about half of all U.S. states. This paper explores the key factors at play in the states that have achieved a substantial amount of wind energy investment. Some of the factors that are examined include policy drivers, such as renewable portfolio standards (RPS), federal and state financial incentives, and integrated resource planning; as well as market drivers, such as consumer demand for green power, natural gas price volatility, and wholesale market rules.

  3. Reliable and Affordable Control Systems Active Combustor Pattern Factor Control

    NASA Technical Reports Server (NTRS)

    McCarty, Bob; Tomondi, Chris; McGinley, Ray

    2004-01-01

    Active, closed-loop control of combustor pattern factor is a cooperative effort between Honeywell (formerly AlliedSignal) Engines and Systems and the NASA Glenn Research Center to reduce emissions and turbine-stator vane temperature variations, thereby enhancing engine performance and life, and reducing direct operating costs. Total fuel flow supplied to the engine is established by the speed/power control, but the distribution to individual atomizers will be controlled by the Active Combustor Pattern Factor Control (ACPFC). This system consist of three major components: multiple, thin-film sensors located on the turbine-stator vanes; fuel-flow modulators for individual atomizers; and control logic and algorithms within the electronic control.

  4. Platelet activating factor activity in the phospholipids of bovine spermatozoa

    SciTech Connect

    Parks, J.E.; Hough, S.; Elrod, C. )

    1990-11-01

    Platelet activating factor (PAF) has been detected in sperm from several mammalian species and can affect sperm motility and fertilization. Because bovine sperm contain a high percentage of ether-linked phospholipid precursors required for PAF synthesis, a study was undertaken to determine the PAF activity of bovine sperm phospholipids. Total lipids of washed, ejaculated bull sperm were extracted, and phospholipids were fractionated by thin-layer chromatography. Individual phospholipid fractions were assayed for PAF activity on the basis of (3H)serotonin release from equine platelets. PAF activity was detected in the PAF fraction (1.84 pmol/mumol total phospholipid) and in serine/inositol (PS/PI), choline (CP), and ethanolamine phosphoglyceride (EP) and cardiolipin (CA) fractions. Activity was highest in the CP fraction (8.05 pmol/mumol total phospholipid). Incomplete resolution of PAF and neutral lipids may have contributed to the activity in the PS/PI and CA fractions, respectively. Phospholipids from nonsperm sources did not stimulate serotonin release. Platelet activation by purified PAF and by sperm phospholipid fractions was inhibited by the receptor antagonist SRI 63-675. These results indicate that bovine sperm contain PAF and that other sperm phospholipids, especially CP and EP, which are high in glycerylether components, are capable of receptor-mediated platelet activation.

  5. Particle emission factors during cooking activities

    NASA Astrophysics Data System (ADS)

    Buonanno, G.; Morawska, L.; Stabile, L.

    Exposure to particles emitted by cooking activities may be responsible for a variety of respiratory health effects. However, the relationship between these exposures and their subsequent effects on health cannot be evaluated without understanding the properties of the emitted aerosol or the main parameters that influence particle emissions during cooking. Whilst traffic-related emissions, stack emissions and concentrations of ultrafine particles (UFPs, diameter < 100 nm) in urban ambient air have been widely investigated for many years, indoor exposure to UFPs is a relatively new field and in order to evaluate indoor UFP emissions accurately, it is vital to improve scientific understanding of the main parameters that influence particle number, surface area and mass emissions. The main purpose of this study was to characterise the particle emissions produced during grilling and frying as a function of the food, source, cooking temperature and type of oil. Emission factors, along with particle number concentrations and size distributions were determined in the size range 0.006-20 μm using a Scanning Mobility Particle Sizer (SMPS) and an Aerodynamic Particle Sizer (APS). An infrared camera was used to measure the temperature field. Overall, increased emission factors were observed to be a function of increased cooking temperatures. Cooking fatty foods also produced higher particle emission factors than vegetables, mainly in terms of mass concentration, and particle emission factors also varied significantly according to the type of oil used.

  6. Mechanisms of Specificity for Hox Factor Activity

    PubMed Central

    Zandvakili, Arya; Gebelein, Brian

    2016-01-01

    Metazoans encode clusters of paralogous Hox genes that are critical for proper development of the body plan. However, there are a number of unresolved issues regarding how paralogous Hox factors achieve specificity to control distinct cell fates. First, how do Hox paralogs, which have very similar DNA binding preferences in vitro, drive different transcriptional programs in vivo? Second, the number of potential Hox binding sites within the genome is vast compared to the number of sites bound. Hence, what determines where in the genome Hox factors bind? Third, what determines whether a Hox factor will activate or repress a specific target gene? Here, we review the current evidence that is beginning to shed light onto these questions. In particular, we highlight how cooperative interactions with other transcription factors (especially PBC and HMP proteins) and the sequences of cis-regulatory modules provide a basis for the mechanisms of Hox specificity. We conclude by integrating a number of the concepts described throughout the review in a case study of a highly interrogated Drosophila cis-regulatory module named “The Distal-less Conserved Regulatory Element” (DCRE). PMID:27583210

  7. Human factors of powered flight: the Wright brothers' contributions.

    PubMed

    Mohler, Stanley R

    2004-02-01

    Orville and Wilbur Wright of Dayton, OH, not only were the first to fly a powered aircraft, but also pioneered many human factors considerations. While others tried to develop aircraft with a high degree of aerodynamic stability, the Wrights intentionally designed unstable aircraft with "cerebralized" control modeled on bird flight. During 1901-03, the brothers worked with large gliders at Kill Devil Hills, near Kitty Hawk, NC, to develop the first practical human-interactive controls for aircraft pitch, roll, and yaw. On December 17, 1903, they made four controlled, powered flights over the dunes at Kitty Hawk with their Wright Flyer. During the next 2 yr, the Wrights made numerous flights in the Wright Flyers II and III at Huffman Prairie near Dayton. They later developed practical in-flight control of engine power, plus an angle-of-attack sensor and stick-pusher that reduced pilot workload. The brothers' flight demonstrations in the U.S. and Europe during 1908-09 awakened the world to the new age of controlled flight. Orville was the first aviator to use a seat belt. He also introduced a rudder boost/trim control that gave the pilot greater control authority. The Wrights' flight training school in Dayton included a flight simulator of their own design. The Wrights patented their practical airplane and flight control concepts, many of which are still in use today.

  8. Single Phase Passive Rectification Versus Active Rectification Applied to High Power Stirling Engines

    NASA Technical Reports Server (NTRS)

    Santiago, Walter; Birchenough, Arthur G.

    2006-01-01

    Stirling engine converters are being considered as potential candidates for high power energy conversion systems required by future NASA explorations missions. These types of engines typically contain two major moving parts, the displacer and the piston, in which a linear alternator is attached to the piston to produce a single phase sinusoidal waveform at a specific electric frequency. Since all Stirling engines perform at low electrical frequencies (less or equal to 100 Hz), space explorations missions that will employ these engines will be required to use DC power management and distribution (PMAD) system instead of an AC PMAD system to save on space and weight. Therefore, to supply such DC power an AC to DC converter is connected to the Stirling engine. There are two types of AC to DC converters that can be employed, a passive full bridge diode rectifier and an active switching full bridge rectifier. Due to the inherent line inductance of the Stirling Engine-Linear Alternator (SE-LA), their sinusoidal voltage and current will be phase shifted producing a power factor below 1. In order to keep power the factor close to unity, both AC to DC converters topologies will implement power factor correction. This paper discusses these power factor correction methods as well as their impact on overall mass for exploration applications. Simulation results on both AC to DC converters topologies with power factor correction as a function of output power and SE-LA line inductance impedance are presented and compared.

  9. Eliminating a Confounding Factor in Power Law Parameter Interpretation

    NASA Astrophysics Data System (ADS)

    Karst, N.; Dralle, D.; Thompson, S. E.

    2015-12-01

    Power law models of the form y = -axb are used to represent a wide range of phenomena in the physical, biological and social sciences. Power laws are well known to display a "scale-free property", meaning that the value of the exponent b is independent of the unit of measurement (the "scale") of the state variable x. While this makes estimation of the exponent robust, it raises significant estimation challenges for the linear multiplier a. Specifically, if both the multiplier a and exponent b are allowed to vary when undertaking an empirical fitting procedure, then physical units used to measure x induce a formal (i.e., entirely nonphysical) dependence between a and b, because the fitted value of a will contain a (potentially large) multiplicative factor that varies depending on the scale of x. This is problematic for two reasons: (i) if a is to be empirically estimated, but admits a physical interpretation, then the scale-dependent factor can confound the physically meaningful value (ii) the formal relationship between a and b due to the scaling of the relationship obscures any true relationship between the parameters and could motivate a spurious interpretation of their co-variation. To correct this issue, we present a technique to remove the formal correlation between a and b, and demonstrate an application of the technique in the context of streamflow recession analysis, where the falling limb of the hydrograph is modeled using a simple power law relationship, dq/dt = -aqb. Following the decorrelation of (a, b) recession parameter pairs, physically intuitive seasonal patterns, greatly obscured in the original data, are clearly found.

  10. Recombinant human factor VIIa (rFVIIa) can activate factor FIX on activated platelets.

    PubMed

    Gabriel, D A; Li, X; Monroe, D M; Roberts, H R

    2004-10-01

    The studies reported here show that factor (F)VIIa can activate factor (F)IX on activated platelets in the absence of tissue factor. Both FIX and FIXa bind to the activated platelet surface with a K(d) of 8 nM and 2 nM, respectively. With factor (F)VIIIa, FIXa binds more tightly to platelets (K(d) 0.6 nM). At rFVIIa concentrations < 100 nm, no direct binding to the activated platelet surface can be detected with electrophoretic light scattering. However, in the presence of FIX, rFVIIa binding to platelets at concentrations as low as 10 nm rFVIIa can be detected. This is reflected by a decrease in the FIX K(d) from 8 to 1.6 nM. When rFVIIa is added to activated platelets in the presence of both FIX and FVIIIa, the K(d) for FIX decreases to 0.6, suggesting that rFVIIa activates FIX on the surface of activated platelets in the absence of tissue factor. The activation of FIX by FVIIa on activated platelets can also be demonstrated by a functional assay for FIXa. These data show that pharmacological doses of rFVIIa result in the direct activation of FIX by rFVIIa to form additional tenase complexes ultimately resulting in improved thrombin generation. These results may explain, at least in part, the mechanism of action of rFVIIa in hemorrhagic conditions seen in otherwise normal patients who develop an acquired coagulopathy due to trauma, surgery or a variety of other events in which rFVIIa has been found to be effective.

  11. Active Learning: A PowerPoint Tutorial

    ERIC Educational Resources Information Center

    Gareis, Elisabeth

    2007-01-01

    Individual or group presentations are common assignments in business communication courses, and many students use PowerPoint slides as audiovisual support. Frequently, curriculum constraints don't allow instructors much time to teach effective design and delivery of presentation graphics in their courses; guidelines in the form of minilectures or…

  12. Social power and approach-related neural activity.

    PubMed

    Boksem, Maarten A S; Smolders, Ruud; De Cremer, David

    2012-06-01

    It has been argued that power activates a general tendency to approach whereas powerlessness activates a tendency to inhibit. The assumption is that elevated power involves reward-rich environments, freedom and, as a consequence, triggers an approach-related motivational orientation and attention to rewards. In contrast, reduced power is associated with increased threat, punishment and social constraint and thereby activates inhibition-related motivation. Moreover, approach motivation has been found to be associated with increased relative left-sided frontal brain activity, while withdrawal motivation has been associated with increased right sided activations. We measured EEG activity while subjects engaged in a task priming either high or low social power. Results show that high social power is indeed associated with greater left-frontal brain activity compared to low social power, providing the first neural evidence for the theory that high power is associated with approach-related motivation. We propose a framework accounting for differences in both approach motivation and goal-directed behaviour associated with different levels of power.

  13. Active Faults and Nuclear Power Plants

    NASA Astrophysics Data System (ADS)

    Chapman, Neil; Berryman, Kelvin; Villamor, Pilar; Epstein, Woody; Cluff, Lloyd; Kawamura, Hideki

    2014-01-01

    The destruction of the Fukushima Daiichi Nuclear Power Plant (NPP) following the March 2011 Tohoku earthquake and tsunami brought into sharp focus the susceptibility of NPPs to natural hazards. This is not a new issue—seismic hazard has affected the development of plants in the United States, and volcanic hazard was among the reasons for not commissioning the Bataan NPP in the Philippines [Connor et al., 2009].

  14. Phase detector for three-phase power factor controller

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.

  15. Human Factors Considerations in New Nuclear Power Plants: Detailed Analysis.

    SciTech Connect

    OHara,J.; Higgins, J.; Brown, W.; Fink, R.

    2008-02-14

    This Nuclear Regulatory Commission (NRC) sponsored study has identified human-performance issues in new and advanced nuclear power plants. To identify the issues, current industry developments and trends were evaluated in the areas of reactor technology, instrumentation and control technology, human-system integration technology, and human factors engineering (HFE) methods and tools. The issues were organized into seven high-level HFE topic areas: Role of Personnel and Automation, Staffing and Training, Normal Operations Management, Disturbance and Emergency Management, Maintenance and Change Management, Plant Design and Construction, and HFE Methods and Tools. The issues where then prioritized into four categories using a 'Phenomena Identification and Ranking Table' methodology based on evaluations provided by 14 independent subject matter experts. The subject matter experts were knowledgeable in a variety of disciplines. Vendors, utilities, research organizations and regulators all participated. Twenty issues were categorized into the top priority category. This Brookhaven National Laboratory (BNL) technical report provides the detailed methodology, issue analysis, and results. A summary of the results of this study can be found in NUREG/CR-6947. The research performed for this project has identified a large number of human-performance issues for new control stations and new nuclear power plant designs. The information gathered in this project can serve as input to the development of a long-term strategy and plan for addressing human performance in these areas through regulatory research. Addressing human-performance issues will provide the technical basis from which regulatory review guidance can be developed to meet these challenges. The availability of this review guidance will help set clear expectations for how the NRC staff will evaluate new designs, reduce regulatory uncertainty, and provide a well-defined path to new nuclear power plant licensing.

  16. Sustainable Buildings. Using Active Solar Power

    SciTech Connect

    Sharp, M. Keith; Barnett, Russell

    2015-04-20

    The objective of this project is to promote awareness and knowledge of active solar energy technologies by installing and monitoring the following demonstration systems in Kentucky: 1) Pool heating system, Churchill Park School, 2) Water heating and daylighting systems, Middletown and Aiken Road Elementary Schools, 3) Photovoltaic street light comparison, Louisville Metro, 4) up to 25 domestic water heating systems across Kentucky. These tasks will be supported by outreach activities, including a solar energy installer training workshop and a Kentucky Solar Energy Conference.

  17. A high efficiency and power factor, segmented linear constant current LED driver

    NASA Astrophysics Data System (ADS)

    Yongyuan, Li; Wei, Guo; Zhangming, Zhu

    2015-04-01

    A high efficiency, high power factor, and linear constant current LED driver based on adaptive segmented linear architecture is presented. When the input voltage varied, the proposed LED driver automatically switched over LED strings according to the segmented LED voltage drop, which increased the LED lighting time. The efficiency and power factor are improved, while the system design is simplified by this control scheme. Without the usage of electrolytic capacitor and magnetic components, the proposed driver possesses advantages of smaller size, longer lifetime and lower cost over others. The proposed driver is implemented in 0.8 μm 5 V/40 V HVCMOS process, which occupies an active area of 820 × 920 μm2. The measured results show that the average value of the internal reference voltage is 500 ± 7 mV, with a standard deviation of only 4.629 mV, thus LED current can be set accurately. Under 220 V root mean square 50 Hz utility voltage and the number ratio of the three LED strings being 47 : 17 : 16, the system can realize a high power factor of 0.974 and power conversion efficiency of 93.4%. Project supported by the National Natural Science Foundation of China (Nos. 61234002, 61322405, 61306044, 61376033).

  18. The central power source in active galaxies

    NASA Astrophysics Data System (ADS)

    Ptak, Roger; Stoner, Ronald

    Potential sources for the central power in AGN are examined. The continuum, emission line profiles, and time variability and broad emission line region for AGN are analyzed. The supermassive black hole hypothesis, the supermassive magnetized core model of Kundt (1978), and the model of Stoner and Ptak (1984) in which the supermassive stars maintain a kind of long-term quasi-stability, but accretion is balanced by mass loss and spherical bursts rather than in jets are considered. It is argued that the hypothesis that the supermassive blackholes are the central engines for AGN is based on theoretical principles; however, AGN emission line profiles and variability suggest a spherical geometry for the observed components of these engines. Also the supermassive black hole models do not account for all the AGN observations.

  19. Cleavage and activation of human factor IX by serine proteases

    SciTech Connect

    Enfield, D.L.; Thompson, A.R.

    1984-10-01

    Human factor IX circulates as a single-chain glycoprotein. Upon activation in vitro, it is cleaved into disulfide-linked light and heavy chains and an activation peptide. After reduction of activated /sup 125/I-factor IX, the heavy and light chains are readily identified by gel electrophoresis. A direct, immunoradiometric assay for factor IXa was developed to assess activation of factor IX for proteases that cleaved it. The assay utilized radiolabeled antithrombin III with heparin to identify the active site and antibodies to distinguish factor IX. After cleavage of factor IX by factor XIa, factor VIIa-tissue thromboplastin complex, or the factor X-activating enzyme from Russell's viper venom, antithrombin III bound readily to factor IXa. Cleavage of /sup 125/I-factor IX by trypsin, chymotrypsin, and granulocyte elastase in the presence of calcium yielded major polypeptide fragments of the sizes of the factor XIa-generated light and heavy chains. When the immunoradiometric assay was used to assess trypsin-cleaved factor IX, the product bound antithrombin III, but not maximally. After digesting with insolubilized trypsin, clotting activity confirmed activation. In evaluating activation of factor IX, physical evidence of activation cleavages does not necessarily correlate with generation of an active site.

  20. 12 CFR 721.2 - What is an incidental powers activity?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false What is an incidental powers activity? 721.2... INCIDENTAL POWERS § 721.2 What is an incidental powers activity? An incidental powers activity is one that is... activity meets the definition of an incidental power activity if the activity: (a) Is convenient or...

  1. Space Power Amplification with Active Linearly Tapered Slot Antenna Array

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1993-01-01

    A space power amplifier composed of active linearly tapered slot antennas (LTSA's) has been demonstrated and shown to have a gain of 30 dB at 20 GHz. In each of the antenna elements, a GaAs monolithic microwave integrated circuit (MMIC) three-stage power amplifier is integrated with two LTSA's. The LTSA and the MMIC power amplifier has a gain of 11 dB and power added efficiency of 14 percent respectively. The design is suitable for constructing a large array using monolithic integration techniques.

  2. Active lithium chloride cell for spacecraft power

    NASA Technical Reports Server (NTRS)

    Fleischmann, C. W.; Horning, R. J.

    1988-01-01

    An active thionyl chloride high rate battery is under development for spacecraft operations. It is a 540kC (150 Ah) battery capable of pulses up to 75A. This paper describes the design and initial test data on a 'state-of-the-art' cell that has been selected to be the baseline for the prototype cell for that battery. Initial data indicate that the specification can be met with fresh cells. Data for stored cells and additional environmental test data are in the process of being developed.

  3. Factors Related to Perceived Power Usage in Schools

    ERIC Educational Resources Information Center

    Schwarzwald, Joseph; Koslowsky, Meni; Brody-Shamir, Shlomit

    2006-01-01

    Based on Raven's (1992) power interaction model, situational and personal variables were examined as determinants of power choice in educational settings. The impact of educational sector (secular, religious), class level, gender and content of conflict on perceived power usage in teacher-pupil conflicts was analysed. A total of 370 elementary and…

  4. Characterization of the clotting activities of structurally different forms of activated factor IX. Enzymatic properties of normal human factor IXa alpha, factor IXa beta, and activated factor IX Chapel Hill.

    PubMed Central

    Griffith, M J; Breitkreutz, L; Trapp, H; Briet, E; Noyes, C M; Lundblad, R L; Roberts, H R

    1985-01-01

    Two structurally different forms of activated human Factor IX (Factor IXa alpha and IXa beta) have been previously reported to have essentially identical clotting activity in vitro. Although it has been shown that activated Factor IX Chapel Hill, an abnormal Factor IX isolated from the plasma of a patient with mild hemophilia B, and normal Factor IXa alpha are structurally very similar, the clotting activity of activated Factor IX Chapel Hill is much lower (approximately fivefold) than that of normal Factor IXa beta. In the present study we have prepared activated Factor IX by incubating human Factor IX with calcium and Russell's viper venom covalently bound to agarose. Fractionation of the activated Factor IX by high-performance liquid chromatography demonstrated the presence of both Factors IXa alpha and IXa beta. On the basis of active site concentration, determined by titration with antithrombin III, the clotting activities of activated Factor IX Chapel Hill and IXa alpha were similar, but both activities were less than 20% of the clotting activity of Factor IXa beta. Activated Factor IX activity was also measured in the absence of calcium, phospholipid, and Factor VIII, by determination of the rate of Factor X activation in the presence of polylysine. In the presence of polylysine, the rates of Factor X activation by activated Factor IX Chapel Hill, Factor IXa alpha, and Factor IXa beta were essentially identical. We conclude that the clotting activity of activated Factor IX Chapel Hill is reduced when compared with that of Factor IXa beta but essentially normal when compared with that of Factor IXa alpha. PMID:3871202

  5. A feedforward compensation design in critical conduction mode boost power factor correction for low-power low totalharmonic distortion

    NASA Astrophysics Data System (ADS)

    Yani, Li; Yintang, Yang; Zhangming, Zhu; Wei, Qiang

    2012-03-01

    For low-power low total harmonic distortion (THD), based on the CSMC 0.5 μm BCD process, a novel boost power factor correction (PFC) converter in critical conduction mode is discussed and analyzed. Feedforward compensation design is introduced in order to increase the PWM duty cycle and supply more conversion energy near the input voltage zero-crossing points, thus regulating the inductor current of the PFC converter and compensating the system loop gain change with ac line voltage. Both theoretical and practical results reveal that the proposed PFC converter with feedforward compensation cell has better power factor and THD performance, and is suitable for low-power low THD design applications. The experimental THD of the boost PFC converter is 4.5%, the start-up current is 54 μA, the stable operating current is 3.85 mA, the power factor is 0.998 and the efficiency is 95.2%.

  6. Factor V activation and inactivation by venom proteases.

    PubMed

    Rosing, J; Govers-Riemslag, J W; Yukelson, L; Tans, G

    2001-01-01

    Blood coagulation factor V is a single-chain glycoprotein with M(r) = 330,000 which plays an important role in the procoagulant and anticoagulant pathways. Thrombin activates factor V into factor Va, a two-chain molecule which is composed of a heavy (M(r) = 105,000) and a light chain (M(r) = 71,000/74,000). Factor Va accelerates factor Xa-catalysed prothrombin activation more than 1,000-fold and under physiological conditions the cofactor activity of factor Va in prothrombin activation is down-regulated by activated protein C. Factor V can also be activated by a wide variety of snake venoms (e.g. from Vipera species, Naja naja oxiana, Bothrops atrox) and by proteases present in the bristles of a South American caterpillar (Lonomia achelous). Some venoms, notably of Vipera lebetina turanica and Lonomia achelous, contain proteases that are able to inactivate factor V or factor Va. Venom factor V activators are excellent tools in studying the structure-function relationship of factor V(a) and they are also used in diagnostic tests for quantification of plasma factor V levels and for the screening of defects in the protein C pathway. In this review, the structural and functional properties of animal venom factor V activators and inactivators is described. PMID:11910191

  7. Flame-powered trigger device for activating explosion suppression barrier

    SciTech Connect

    Cortese, R.A.; Sapko, M.J.

    1991-01-01

    This paper reports that the U.S. Bureau of Mines has developed a flame-radiation-powered trigger device to explosively activate suppression barriers to quench gas and coal dust explosions. The major component of the device is a silicon solar panel, which concerts radiation from the developing explosion into electrical energy to initiate an electric detonator, which releases an extinguishing agent into the advancing flame front. Solar panels that are rated to produce 20 W of electrical power when exposed to the sunlight are producing about 200 W when exposed to a full-scale dust explosion. The solar panel is electrically isolated from the detonator by a pressure-sensitive switch until the arrival of the precursor pressure pulse, which always precedes a deflagration. This combination of pressure arming and flame-powered photogenerator prevents false barrier activation and requires no external power supply.

  8. Gamma power is phase-locked to posterior alpha activity.

    PubMed

    Osipova, Daria; Hermes, Dora; Jensen, Ole

    2008-01-01

    Neuronal oscillations in various frequency bands have been reported in numerous studies in both humans and animals. While it is obvious that these oscillations play an important role in cognitive processing, it remains unclear how oscillations in various frequency bands interact. In this study we have investigated phase to power locking in MEG activity of healthy human subjects at rest with their eyes closed. To examine cross-frequency coupling, we have computed coherence between the time course of the power in a given frequency band and the signal itself within every channel. The time-course of the power was calculated using a sliding tapered time window followed by a Fourier transform. Our findings show that high-frequency gamma power (30-70 Hz) is phase-locked to alpha oscillations (8-13 Hz) in the ongoing MEG signals. The topography of the coupling was similar to the topography of the alpha power and was strongest over occipital areas. Interestingly, gamma activity per se was not evident in the power spectra and only became detectable when studied in relation to the alpha phase. Intracranial data from an epileptic subject confirmed these findings albeit there was slowing in both the alpha and gamma band. A tentative explanation for this phenomenon is that the visual system is inhibited during most of the alpha cycle whereas a burst of gamma activity at a specific alpha phase (e.g. at troughs) reflects a window of excitability. PMID:19098986

  9. Introducing Power Factor for Inter-Nation Comparisons.

    ERIC Educational Resources Information Center

    Thomas, Paul F.

    This document, which primarily contains statistical tables of data, is designed to help teach secondary school students how to compare the power levels of 186 countries. The three indicators or measures of economic strength include a country's total population, total area, and per capita income, and they are used to determine power levels. A…

  10. Factors Influencing Cypriot Children's Physical Activity Levels

    ERIC Educational Resources Information Center

    Loucaides, Constantinos A.; Chedzoy, Sue M.

    2005-01-01

    The purpose of this paper is to present selected findings from a larger study, which set out to examine the physical activity levels of Cypriot primary school children and determinants of their activity. Twenty parents of children who obtained high and low activity scores based on pedometer counts and self-reports scores were interviewed. By…

  11. Establishing a value chain for human factors in nuclear power plantcontrol room modernization

    SciTech Connect

    Joe, Jeffrey Clark; Thomas, Kenneth David; Boring, Ronald Laurids

    2015-07-01

    Commercial nuclear power plants in the United States (U.S.) have operated reliably and efficiently for decades. With the life extensions of plants now being planned for operation beyond their original operating licenses, there are opportunities to achieve even greater efficiencies, while maintaining high operational reliabilities, with strategic, risk- and economically-informed, upgrades to plant systems and infrastructure. The U.S. Department of Energy’s Light Water Reactor Sustainability (LWRS) program supports the commercial nuclear industry’s modernization efforts through research and development (R&D) activities across many areas to help establish the technical and economic bases for modernization activities. The Advanced Instrumentation, Information, and Control Systems Technologies pathway is one R&D focus area for the LWRS program, and has researchers at Idaho National Laboratory working with select utility partners to use human factors and instrumentation and controls R&D to help modernize the plant’s main control room. However, some in the nuclear industry have not been as enthusiastic about using human factors R&D to inform life extension decision making. Part of the reason for this may stem from uncertainty decision-makers have regarding how human factors fits into the value chain for nuclear power plant control room modernization. This paper reviews past work that has attempted to demonstrate the value of human factors, and then describes the value chain concept, how it applies to control room modernization, and then makes a case for how and why human factors is an essential link in the modernization value chain.

  12. A new method for both harmonic voltage and harmonic current suppression and power factor correction in industrial power systems

    SciTech Connect

    Cheng, H.; Sasaki, Hiroshi; Yorino, Naoto

    1995-12-31

    This paper proposes a new method for designing a group of single tuned filters for both harmonic current injection suppression and harmonic voltage distortion reduction and power factor correction. The proposed method is based on three purposes: (1) reduction of harmonic voltage distortion in the source terminals to an acceptable level, (2) suppression of harmonic current injection in the source terminals to an acceptable level, (3) improvement of power factor at the source terminals. To determine the size of the capacitor in a group of single tuned filters, three new NLP mathematical formulations will be introduced. The first is to suppress harmonic current injection within an acceptable level. The second is to minimize the fundamental reactive power output while reducing harmonic voltage distortion to an acceptable level. The third is to determine an optimal assignment of reactive power output based on the results of harmonic voltage reduction and power factor correction. This new method has been demonstrated for designing a group of single tuned filters and its validity has been successfully confirmed through numerical simulation in a 35 KV industrial power system. The proposed method can efficiently provide an optimal coordination in a group of single tuned filters relating to suppressing harmonic current injection, reducing harmonic voltage distortion and improving power factor.

  13. The influence of stopping power on the ionisation quench factor.

    PubMed

    García, G; Grau, Malonda A

    2002-01-01

    Stopping power values for high energies have been computed applying the first Born approximation and the Bethe formula. However, this approximation tends to overestimate these cross sections at low energies, reaching discrepancies on the order of 50% at energies below 1 keV for most of the molecular targets of interest. In this paper we propose a method to obtain accurate low energy stopping powers of electrons by combining total cross section measurements with a theoretical treatment of the elastic process. We determine the optimum value of the kB parameter of ionisation quenching for the stopping power obtained in this paper.

  14. Assessment of economic factors affecting the satellite power system. Volume 1: System cost factors

    NASA Technical Reports Server (NTRS)

    Hazelrigg, G. A., Jr.

    1978-01-01

    The factors relevant to SPS costing and selection of preferred SPS satellite configurations were studied. The issues discussed are: (1) consideration of economic factors in the SPS system that relate to selection of SPS satellite configuration; (2) analysis of the proper rate of interest for use in SPS system definition studies; and (3) the impacts of differential inflation on SPS system definition costing procedures. A cost-risk comparison of the SPS satellite configurations showed a significant difference in the levelized cost of power from them. It is concluded, that this difference is the result more of differences in the procedures for assessing costs rather than in the satellite technologies required or of any advantages of one satellite configuration over the other. Analysis of the proper rate of interest for use in SPS system is 4 percent. The major item of differential inflation to be expected over this period of time is the real cost of labor. This cost is likely to double between today and the period of SPS construction.

  15. Co-factor activated recombinant adenovirus proteinases

    SciTech Connect

    Anderson, C.W.; Mangel, W.F.

    1996-08-06

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying the peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described. 29 figs.

  16. Co-factor activated recombinant adenovirus proteinases

    DOEpatents

    Anderson, Carl W.; Mangel, Walter F.

    1996-08-06

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

  17. Design of a multilevel Active Power Filter for More Electrical Airplane variable frequency systems

    NASA Astrophysics Data System (ADS)

    Guerreiro, Joel Filipe; Pomilio, Jose Antenor; Busarello, Tiago Davi Curi

    This paper presents the design and simulation of an Aeronautical Active Power Filter (AAPF) for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The purposes of the AAPF are to mitigate current harmonics, to improve the source power factor and to mitigate the effects of unbalanced loads. Regarding the fact that the Aircraft Electrical Power System (AEPS) frequency may vary between 360 Hz and 900 Hz, and the load dynamics is often modified, an enhanced filtering technique is required. The designed AAPF topology is an asymmetrical multilevel inverter (AMI), which control strategy is based on the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). The above configuration renders the AAPF very robust and effective to its purpose. Accurate simulation results on Matlab/Simulink platform verify the feasibility of the proposed AAPF and the high performance of the control strategy during steady-state and dynamic operations.

  18. High Quality Factor Resonators for Inductive Power Transfer Systems

    NASA Astrophysics Data System (ADS)

    Etemadrezaei, Mohammad

    In this dissertation, the Inductive Power Transfer (IPT) systems for multi-MHz frequency of operation are investigated, and new ideas for magnetic link inductive coils are presented. (Abstract shortened by ProQuest.).

  19. Virulence Factor-activity Relationships: Workshop Summary

    EPA Science Inventory

    The concept or notion of virulence factor–activity relationships (VFAR) is an approach for identifying an analogous process to the use of qualitative structure–activity relationships (QSAR) for identifying new microbial contaminants. In QSAR, it is hypothesized that, for new chem...

  20. Kinetics of the Factor XIa catalyzed activation of human blood coagulation Factor IX

    SciTech Connect

    Walsh, P.N.; Bradford, H.; Sinha, D.; Piperno, J.R.; Tuszynski, G.P.

    1984-05-01

    The kinetics of activation of human Factor IX by human Factor XIa was studied by measuring the release of a trichloroacetic acid-soluble tritium-labeled activation peptide from Factor IX. Initial rates of trichloroacetic acid-soluble /sup 3/H-release were linear over 10-30 min of incubation of Factor IX (88 nM) with CaCl/sub 2/ (5 mM) and with pure (greater than 98%) Factor XIa (0.06-1.3 nM), which was prepared by incubating human Factor XI with bovine Factor XIIa. Release of /sup 3/H preceded the appearance of Factor IXa activity, and the percentage of /sup 3/H released remained constant when the mole fraction of /sup 3/H-labeled and unlabeled Factor IX was varied and the total Factor IX concentration remained constant. A linear correlation (r greater than 0.98, P less than 0.001) was observed between initial rates of /sup 3/H-release and the concentration of Factor XIa, measured by chromogenic assay and by radioimmunoassay and added at a Factor IX:Factor XIa molar ratio of 70-5,600. Kinetic parameters, determined by Lineweaver-Burk analysis, include K/sub m/ (0.49 microM) of about five- to sixfold higher than the plasma Factor IX concentration, which could therefore regulate the reaction. The catalytic constant (k/sub cat/) (7.7/s) is approximately 20-50 times higher than that reported by Zur and Nemerson for Factor IX activation by Factor VIIa plus tissue factor. Therefore, depending on the relative amounts of Factor XIa and Factor VIIa generated in vivo and other factors which may influence reaction rates, these kinetic parameters provide part of the information required for assessing the relative contributions of the intrinsic and extrinsic pathways to Factor IX activation, and suggest that the Factor XIa catalyzed reaction is physiologically significant.

  1. Plasma Switch for High-Power Active Pulse Compressor

    SciTech Connect

    Hirshfield, Jay L.

    2013-11-04

    Results are presented from experiments carried out at the Naval Research Laboratory X-band magnicon facility on a two-channel X-band active RF pulse compressor that employed plasma switches. Experimental evidence is shown to validate the basic goals of the project, which include: simultaneous firing of plasma switches in both channels of the RF circuit, operation of quasi-optical 3-dB hybrid directional coupler coherent superposition of RF compressed pulses from both channels, and operation of the X-band magnicon directly in the RF pulse compressor. For incident 1.2 ?s pulses in the range 0.63 ? 1.35 MW, compressed pulses of peak powers 5.7 ? 11.3 MW were obtained, corresponding to peak power gain ratios of 8.3 ? 9.3. Insufficient bakeout and conditioning of the high-power RF circuit prevented experiments from being conducted at higher RF input power levels.

  2. Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors

    NASA Astrophysics Data System (ADS)

    Hung, Nguyen T.; Hasdeo, Eddwi H.; Nugraha, Ahmad R. T.; Dresselhaus, Mildred S.; Saito, Riichiro

    2016-07-01

    We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one- and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ , bulk semiconductors may give a higher power factor compared to the lower dimensional ones.

  3. Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors.

    PubMed

    Hung, Nguyen T; Hasdeo, Eddwi H; Nugraha, Ahmad R T; Dresselhaus, Mildred S; Saito, Riichiro

    2016-07-15

    We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one- and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ, bulk semiconductors may give a higher power factor compared to the lower dimensional ones. PMID:27472126

  4. Quantum Effects in the Thermoelectric Power Factor of Low-Dimensional Semiconductors.

    PubMed

    Hung, Nguyen T; Hasdeo, Eddwi H; Nugraha, Ahmad R T; Dresselhaus, Mildred S; Saito, Riichiro

    2016-07-15

    We theoretically investigate the interplay between the confinement length L and the thermal de Broglie wavelength Λ to optimize the thermoelectric power factor of semiconducting materials. An analytical formula for the power factor is derived based on the one-band model assuming nondegenerate semiconductors to describe quantum effects on the power factor of the low-dimensional semiconductors. The power factor is enhanced for one- and two-dimensional semiconductors when L is smaller than Λ of the semiconductors. In this case, the low-dimensional semiconductors having L smaller than their Λ will give a better thermoelectric performance compared to their bulk counterpart. On the other hand, when L is larger than Λ, bulk semiconductors may give a higher power factor compared to the lower dimensional ones.

  5. Factors affecting speed in human-powered vehicles.

    PubMed

    White, A P

    1994-10-01

    It is shown how to derive the appropriate cubic equation relating power and the effects of friction, gradient and wind resistance on the speed of a human-powered vehicle (HPV). The effects of gradient and wind resistance are explored for parameters representing a typical racing cyclist. The principal conclusion may be summarized as follows: for optimum performance in a time trial, there should be no wind and the course should be level. Any deviation from these conditions will produce a decrement in performance.

  6. Cooperative Control of Active Power Filters in Power Systems without Mutual Communication

    DOE PAGES

    Tlustý, Josef; Škramlík, Jiří; Švec, Jan; Valouch, Viktor

    2010-01-01

    The procedure for calculating controller parameters of the APFs implemented into a multibus industrial power system for harmonic voltage mitigation is presented. The node-voltage-detection control strategy is applied and the basic controller parameters are found under the condition that the demanded THD factors at the buses where the APFs are placed will be obtained. A cooperative control of several APFs without mutual communication is proposed, simulated, and experimentally verified. By tuning the controller gains without considering the power circuit parameters, all APFs used tend to share harmonic load currents approximately equally regardless of the operation modes of the nonlinear loadsmore » in different parts of the power system.« less

  7. The Molecular Mechanism of Eukaryotic Elongation Factor 2 Kinase Activation*

    PubMed Central

    Tavares, Clint D. J.; Ferguson, Scarlett B.; Giles, David H.; Wang, Qiantao; Wellmann, Rebecca M.; O'Brien, John P.; Warthaka, Mangalika; Brodbelt, Jennifer S.; Ren, Pengyu; Dalby, Kevin N.

    2014-01-01

    Calmodulin (CaM)-dependent eukaryotic elongation factor 2 kinase (eEF-2K) impedes protein synthesis through phosphorylation of eukaryotic elongation factor 2 (eEF-2). It is subject to complex regulation by multiple upstream signaling pathways, through poorly described mechanisms. Precise integration of these signals is critical for eEF-2K to appropriately regulate protein translation rates. Here, an allosteric mechanism comprising two sequential conformations is described for eEF-2K activation. First, Ca2+/CaM binds eEF-2K with high affinity (Kd(CaM)app = 24 ± 5 nm) to enhance its ability to autophosphorylate Thr-348 in the regulatory loop (R-loop) by > 104-fold (kauto = 2.6 ± 0.3 s−1). Subsequent binding of phospho-Thr-348 to a conserved basic pocket in the kinase domain potentially drives a conformational transition of the R-loop, which is essential for efficient substrate phosphorylation. Ca2+/CaM binding activates autophosphorylated eEF-2K by allosterically enhancing kcatapp for peptide substrate phosphorylation by 103-fold. Thr-348 autophosphorylation results in a 25-fold increase in the specificity constant (kcatapp/Km(Pep-S)app), with equal contributions from kcatapp and Km(Pep-S)app, suggesting that peptide substrate binding is partly impeded in the unphosphorylated enzyme. In cells, Thr-348 autophosphorylation appears to control the catalytic output of active eEF-2K, contributing more than 5-fold to its ability to promote eEF-2 phosphorylation. Fundamentally, eEF-2K activation appears to be analogous to an amplifier, where output volume may be controlled by either toggling the power switch (switching on the kinase) or altering the volume control (modulating stability of the active R-loop conformation). Because upstream signaling events have the potential to modulate either allosteric step, this mechanism allows for exquisite control of eEF-2K output. PMID:25012662

  8. Influencing Factors of Thermogenic Adipose Tissue Activity

    PubMed Central

    Zhang, Guoqing; Sun, Qinghua; Liu, Cuiqing

    2016-01-01

    Obesity is an escalating public health challenge and contributes tremendously to the disease burden globally. New therapeutic strategies are required to alleviate the health impact of obesity-related metabolic dysfunction. Brown adipose tissue (BAT) is specialized for dissipating chemical energy for thermogenesis as a defense against cold environment. Intriguingly, the brown-fat like adipocytes that dispersed throughout white adipose tissue (WAT) in rodents and humans, called “brite” or “beige” adipocytes, share similar thermogenic characteristics to brown adipocytes. Recently, researchers have focused on cognition of these thermogenic adipose tissues. Some factors have been identified to regulate the development and function of thermogenic adipose tissues. Cold exposure, pharmacological conditions, and lifestyle can enhance non-shivering thermogenesis and metabolism via some mechanisms. However, environmental pollutants, such as ambient fine particulates and ozone, may impair the function of these thermogenic adipose tissues and thereby induce metabolic dysfunction. In this review, the origin, function and influencing factors of thermogenic adipose tissues were summarized and it will provide insights into identifying new therapeutic strategies for the treatment of obesity and obesity-related diseases. PMID:26903879

  9. Influencing Factors of Thermogenic Adipose Tissue Activity.

    PubMed

    Zhang, Guoqing; Sun, Qinghua; Liu, Cuiqing

    2016-01-01

    Obesity is an escalating public health challenge and contributes tremendously to the disease burden globally. New therapeutic strategies are required to alleviate the health impact of obesity-related metabolic dysfunction. Brown adipose tissue (BAT) is specialized for dissipating chemical energy for thermogenesis as a defense against cold environment. Intriguingly, the brown-fat like adipocytes that dispersed throughout white adipose tissue (WAT) in rodents and humans, called "brite" or "beige" adipocytes, share similar thermogenic characteristics to brown adipocytes. Recently, researchers have focused on cognition of these thermogenic adipose tissues. Some factors have been identified to regulate the development and function of thermogenic adipose tissues. Cold exposure, pharmacological conditions, and lifestyle can enhance non-shivering thermogenesis and metabolism via some mechanisms. However, environmental pollutants, such as ambient fine particulates and ozone, may impair the function of these thermogenic adipose tissues and thereby induce metabolic dysfunction. In this review, the origin, function and influencing factors of thermogenic adipose tissues were summarized and it will provide insights into identifying new therapeutic strategies for the treatment of obesity and obesity-related diseases. PMID:26903879

  10. Incidents at nuclear power plants caused by the human factor

    SciTech Connect

    Mashin, V. A.

    2012-09-15

    Psychological analysis of the causes of incorrect actions by personnel is discussed as presented in the report 'Methodological guidelines for analyzing the causes of incidents in the operation of nuclear power plants.' The types of incorrect actions and classification of the root causes of errors by personnel are analyzed. Recommendations are made for improvements in the psychological analysis of causes of incorrect actions by personnel.

  11. Active and Passive RF Components for High-Power Systems

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami G.; Nantista, Christopher D.

    2002-08-01

    In recent years, R&D for pulse compression and power distribution systems for the Next Linear Collider has led to the invention of many novel rf components, some of which must handle up to 600 MW of pulsed power at X-band. These include passive waveguide components, active switch designs, and non-reciprocal devices. Among the former is a class of multi-moded, highly efficient rf components based on planar geometries with overmoded rectangular ports. Multi-moding allows us, by means of input phasing, to direct power to different locations through the same waveguide. Planar symmetry allows the height to be increased to improve power handling capacity. Features that invite breakdown, such as coupling slots, irises and H-plane septa, are avoided. This class includes hybrids, directional couplers, an eight-port superhybrid/dual-mode launcher, a mode-selective extractor, mode-preserving bends, a rectangular mode converter, and mode-mixers. We are able to utilize such rectangular waveguide components in systems incorporating low-loss, circular waveguide delay lines by means of specially designed tapers that efficiently transform multiple rectangular waveguide modes into their corresponding circular waveguide modes, specifically TE10 and TE20 into circular TE11 and TE01. These extremely compact tapers can replace well-known mode converters such as the Marie type. Another component, a reflective TE01-TE02 mode converter in circular waveguide, allows us to double the delay in reflective or resonant delay lines. Ideas for multi-megawatt active components, such as switches, have also been pursued. Power-handling capacity for these is increased by making them also highly overmoded. We present a design methodology for active rf magnetic components which are suitable for pulse compression systems of future X-band linear colliders. We also present an active switch based on a PIN diode array. This component comprises an array of active elements arranged so that the electric fields

  12. Active dehydration impairs upper and lower body anaerobic muscular power.

    PubMed

    Jones, Leon C; Cleary, Michelle A; Lopez, Rebecca M; Zuri, Ron E; Lopez, Richard

    2008-03-01

    We examined the effects of active dehydration by exercise in a hot, humid environment on anaerobic muscular power using a test-retest (euhydrated and dehydrated) design. Seven subjects (age, 27.1 +/- 4.6 years; mass, 86.4 +/- 9.5 kg) performed upper and lower body Wingate anaerobic tests prior to and after a 1.5-hour recovery from a heat stress trial of treadmill exercise in a hot, humid environment (33.1 +/- 3.1C = 55.1 +/- 8.9% relative humidity) until a 3.1 +/- 0.3% body mass loss was achieved. Dehydration was confirmed by a significant body mass loss (P < 0.001), urine color increase (P = 0.004), and urine specific gravity increase (P = 0.041). Motivation ratings were not significantly different (P = 0.059), and fatigue severity was significantly (P = 0.009) increased 70% in the dehydrated compared to the euhydrated condition. Compared to the euhydrated condition, the dehydrated condition mean power was significantly (P = 0.014) decreased 7.17% in the upper body and 19.20% in the lower body. Compared to the euhydrated condition, the dehydrated condition peak power was significantly (P = 0.013) decreased 14.48% in the upper body and 18.36% in the lower body. No significant differences between the euhydrated and dehydrated conditions were found for decrease in power output (P = 0.219, power = 0.213). Our findings suggest that dehydration of 2.9% body mass decreases the ability to generate upper and lower body anaerobic power. Coaches and athletes must understand that sports performance requiring anaerobic strength and power can be impaired by inadequate hydration and may contribute to increased susceptibility to musculoskeletal injury.

  13. Human Factors Evaluation of Advanced Electric Power Grid Visualization Tools

    SciTech Connect

    Greitzer, Frank L.; Dauenhauer, Peter M.; Wierks, Tamara G.; Podmore, Robin

    2009-04-01

    This report describes initial human factors evaluation of four visualization tools (Graphical Contingency Analysis, Force Directed Graphs, Phasor State Estimator and Mode Meter/ Mode Shapes) developed by PNNL, and proposed test plans that may be implemented to evaluate their utility in scenario-based experiments.

  14. Factor XIa induced activation of the intrinsic cascade in vivo.

    PubMed

    ten Cate, H; Biemond, B J; Levi, M; Wuillemin, W A; Bauer, K A; Barzegar, S; Buller, H R; Hack, C E; ten Cate, J W; Rosenberg, R D

    1996-03-01

    Coagulation factor XI is a glycoprotein of the contact factor system. Its deficiency is associated with a highly variable bleeding tendency, thus a role in relation to hemostasis appears to exist. However, the importance of factor XI for stimulating intrinsic coagulation in vivo has not yet been determined. To study the procoagulant effects of human factor XIa in vivo, we infused the purified enzyme into normal chimpanzees (100 micrograms) in the absence or presence of the thrombin inhibitor rec-hirudin (1.0 mg/kg loading dose plus 0.3 mg/kg body wt continuous infusion). Factor XIa elicited an immediate activation of factors IX, X, and prothrombin, as measured by their respective activation fragments. However, whereas the activation of factors IX and X was immediate and shortlasting, (peak increments of 6- and 1.4-fold of baseline at 5 minutes after injection), the conversion of prothrombin gradually increased, reaching a summit of 6-fold baseline values after 60 min, and remaining elevated during the course of the experiments. Thrombin-antithrombin complexes also remained elevated during the study period. In the presence of hirudin, the initial activation of factors IX, X, and prothrombin was unchanged, however the further increment in prothrombin fragment F1 + 2 was markedly inhibited. These results demonstrate that factor XIa is a potential agonist of the intrinsic cascade in vivo, which activity is enhanced in the presence of thrombin.

  15. Factor XI and Contact Activation as Targets for Antithrombotic Therapy

    PubMed Central

    Gailani, David; Bane, Charles E.; Gruber, Andras

    2015-01-01

    Summary The most commonly used anticoagulants produce therapeutic antithrombotic effects either by inhibiting thrombin or factor Xa, or by lowering the plasma levels of the precursors of these key enzymes, prothrombin and factor X. These drugs do not distinguish between thrombin generation contributing to thrombosis from thrombin generation required for hemostasis. Thus, anticoagulants increase bleeding risk, and many patients who would benefit from therapy go untreated because of comorbidities that place them at unacceptable risk for hemorrhage. Studies in animals demonstrate that components of the plasma contact activation system contribute to experimentally-induced thrombosis, despite playing little or no role in hemostasis. Attention has focused on factor XII, the zymogen of a protease (factor XIIa) that initiates contact activation when blood is exposed to foreign surfaces; and factor XI, the zymogen of the protease factor XIa, which links contact activation to the thrombin generation mechanism. In the case of factor XI, epidemiologic data indicate this protein contributes to stroke and venous thromboembolism, and perhaps myocardial infarction, in humans. A phase 2 trial showing that reduction of factor XI may be more effective than low-molecular-weight heparin at preventing venous thrombosis during knee replacement surgery provides proof of concept for the premise that an antithrombotic effect can be uncoupled from an anticoagulant effect in humans by targeting components of contact activation. Here we review data on the role of factor XI and factor XII in thrombosis, and results of pre-clinical and human trials for therapies targeting these proteins. PMID:25976012

  16. Socioeconomic Factors Influence Physical Activity and Sport in Quebec Schools

    ERIC Educational Resources Information Center

    Morin, Pascale; Lebel, Alexandre; Robitaille, Éric; Bisset, Sherri

    2016-01-01

    Background: School environments providing a wide selection of physical activities and sufficient facilities are both essential and formative to ensure young people adopt active lifestyles. We describe the association between school opportunities for physical activity and socioeconomic factors measured by low-income cutoff index, school size…

  17. The Secondary Structure of Human Hageman Factor (Factor XII) and its Alteration by Activating Agents

    PubMed Central

    McMillin, Carl R.; Saito, Hidehiko; Ratnoff, Oscar D.; Walton, Alan G.

    1974-01-01

    Hageman factor (factor XII) is activated by exposure to surfaces such as glass or by solutions of certain compounds, notably ellagic acid. Changes in the structure of Hageman factor accompanying activation have been examined in this study by circular dichroism spectroscopy. The spectrum of unactivated Hageman factor in aqueous solutions suggests that its conformation is mainly aperiodic. Various perturbants altered the conformation of Hageman factor in differing ways, demonstrating the sensitivity of Hageman factor to its environment. After activation of Hageman factor with solutions of ellagic acid, a negative trough appeared in the region of the circular dichroism spectrum commonly assigned to tyrosine residues, along with other minor changes in the peptide spectral region. Some of these changes are similar to changes that occurred upon partial neutralization of the basic residues at alkali pH. Activation of Hageman factor by adsorption to quartz surfaces (in an aqueous environment) also produced changes similar to those in the ellagic acid-activated Hageman factor, including the negative ellipticity in the tyrosine region. These observations suggest that the activation process may be related to a change in status of some of the basic amino acid residues, coupled with a specific change in the environment of some tyrosine residues. The importance of these changes during the activation process remains to be determined. The sensitivity of Hageman factor to its environment is consistent with the view that the initiation of clotting by exposure of plasma to appropriate agents is brought about by alterations in the conformation of Hageman factor that occur in the apparent absence of Fletcher factor or other recognized clotting factors. Images PMID:4373492

  18. Protective actions as a factor in power reactor siting

    SciTech Connect

    Gant, K.S.; Schweitzer, M.

    1984-06-01

    This report examines the relationship between a power reactor site and the ease of implementing protective actions (emergency measures a serious accident). Limiting populating density around a reactor lowers the number of people at risk but cannot assure that all protective actions are possible for those who reside near the reactor. While some protective measures can always be taken (i.e., expedient respiratory protection, sheltering) the ability to evacuate the area or find adequate shelter may depend on the characteristics of the area near the reactor site. Generic siting restrictions designed to identify and eliminate these site-specific constraints would be difficult to formulate. The authors suggest identifying possible impediments to protective actions at a proposed reactor site and addressing these problems in the emergency plans. 66 references, 6 figures, 8 tables.

  19. Fuzzy based power factor improvement strategy for a multiple connected AC-DC converter fed drive

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, N.; Muthiah, Ramaswamy

    2012-01-01

    The main focus of this paper is to design a Fuzzy based control algorithm to realize an improvement in the input power factor of a multiple connected AC-DC converter fed drive system. It incorporates the role of fuzzy inference principles to generate appropriate PWM pulses for the power switches at the second stage of the power module. The philosophy is developed, with a view to reshape the input current phasor and enables it to align with the supply voltage wave in the perspective of improving the input power factor. The closed loop scheme evaluated using MATLAB based simulation exhibits an enhancement in supply power factor over a range of operating loads in addition to illustrating the speed regulating capability of the drive.

  20. SV-IV Peptide1–16 reduces coagulant power in normal Factor V and Factor V Leiden

    PubMed Central

    Di Micco, Biagio; Lepretti, Marilena; Rota, Lidia; Quaglia, Ilaria; Ferrazzi, Paola; Di Micco, Gianluca; Di Micco, Pierpaolo

    2007-01-01

    Native Factor V is an anticoagulant, but when activated by thrombin, Factor X or platelet proteases, it becomes a procoagulant. Due to these double properties, Factor V plays a crucial role in the regulation of coagulation/anticoagulation balance. Factor V Leiden (FVL) disorder may lead to thrombophilia. Whether a reduction in the activation of Factor V or Factor V Leiden may correct the disposition to thrombophilia is unknown. Therefore we tested SV-IV Peptide 1–16 (i.e. a peptide derived by seminal protein vescicle number IV, SV-IV) to assess its capacity to inhibit the procoagulant activity of normal clotting factor V or Factor V Leiden (FVL). We found that SV-IV protein has potent anti-inflammatory and immunomodulatory properties and also exerts procoagulant activity. In the present work we show that the SV-IV Peptide 1–16, incubated with plasma containing normal Factor V or FVL plasma for 5 minutes reduces the procoagulant capacity of both substances. This is an anticoagulant effect whereas SV-IV protein is a procoagulant. This activity is effective both in terms of the coagulation tests, where coagulation times are increased, and in terms of biochemical tests conducted with purified molecules, where Factor X activation is reduced. Peptide 1–16 was, in the pure molecule system, first incubated for 5 minutes with purified Factor V then it was added to the mix of phosphatidylserine, Ca2+, Factor X and its chromogenic molecule Chromozym X. We observed a more than 50% reduction in lysis of chromogenic molecule Chromozym X by Factor Xa, compared to the sample without Peptide 1–16. Such reduction in Chromozym X lysis, is explained with the reduced activation of Factor X by partial inactivation of Factor V by Peptide 1–16. Thus our study demonstrates that Peptide 1–16 reduces the coagulation capacity of Factor V and Factor V Leiden in vitro, and, in turn, causes factor X reduced activation. PMID:18154667

  1. Large theoretical thermoelectric power factor of suspended single-layer MoS{sub 2}

    SciTech Connect

    Babaei, Hasan E-mail: babaei@auburn.edu; Khodadadi, J. M.; Sinha, Sanjiv

    2014-11-10

    We have calculated the semi-classical thermoelectric power factor of suspended single-layer (SL)- MoS{sub 2} utilizing electron relaxation times derived from ab initio calculations. Measurements of the thermoelectric power factor of SL-MoS{sub 2} on substrates reveal poor power factors. In contrast, we find the thermoelectric power factor of suspended SL-MoS{sub 2} to peak at ∼2.8 × 10{sup 4} μW/m K{sup 2} at 300 K, at an electron concentration of 10{sup 12} cm{sup −2}. This figure is higher than that in bulk Bi{sub 2}Te{sub 3}, for example. Given its relatively high thermal conductivity, suspended SL-MoS{sub 2} may hold promise for in-plane thin-film Peltier coolers, provided reasonable mobilities can be realized.

  2. An AC motor drive with power factor control for low cost applications

    NASA Astrophysics Data System (ADS)

    Bellar, Maria Dias

    2000-10-01

    The front-end rectifier followed by a pulse-width modulated voltage source inverter (PWM-VSI) has been a well-established power converter configuration for many industrial drives. The increasing costs on the utility usage, due to power quality regulations, and the need to improve the VA capacity of systems, e.g. off-shore drilling rigs, have increased the interest in the development of power electronic equipment with power factor control capability. Electrical motors consume a large amount of the available electrical energy, and this energy tends to increase due to the massive emerging applications of electrical motor drives in appliances and in industrial processes. Therefore, the improvement of the power factor of these low power drive systems, usually in the range from fractional horse-power (hp) to 1 hp, is of particular interest. For these power ratings, the system configuration usually comprises a single-phase to three-phase type of converter with additional circuitry for power factor control (PFC). However, this approach has an impact on the system cost and packaging. In this work, a new concept of integrating motor and power factor controls by using a single-phase to three-phase DSP based six-switch converter topology is presented. Unlike other configurations using extra switch(es) and/or extra boost inductor, in this circuit the boost action, for input current shaping, is done by the motor leakage inductances. The power factor control and inverter operation are performed by applying two modulating signals to the SPWM control logic of the converter. In this dissertation, the converter operation and a proposed control strategy will be explained. Simulation and experimental results for a DSP based induction motor drive will be provided as proof of concept. The feasibility and potential of this configuration for ac motor drive applications will be established. The impact of this scheme on the machine operation will also be discussed.

  3. Factors affecting frequency and orbit utilization by high power transmission satellite systems

    NASA Technical Reports Server (NTRS)

    Kuhns, P. W.; Miller, E. F.; Malley, T. A.

    1972-01-01

    The factors affecting the sharing of the geostationary orbit by high power (primarily television) satellite systems having the same or adjacent coverage areas and by satellites occupying the same orbit segment are examined and examples using the results of computer computations are given. The factors considered include: required protection ratio, receiver antenna patterns, relative transmitter power, transmitter antenna patterns, satellite grouping, and coverage pattern overlap. The results presented indicated the limits of system characteristics and orbit deployment which can result from mixing systems.

  4. Gate-Optimized Thermoelectric Power Factor in Ultrathin WSe2 Single Crystals.

    PubMed

    Yoshida, Masaro; Iizuka, Takahiko; Saito, Yu; Onga, Masaru; Suzuki, Ryuji; Zhang, Yijin; Iwasa, Yoshihiro; Shimizu, Sunao

    2016-03-01

    We report an electric field tuning of the thermopower in ultrathin WSe2 single crystals over a wide range of carrier concentration by using electric double-layer (EDL) technique. We succeeded in the optimization of power factor not only in the hole but also in the electron side, which has never been chemically accessed. The maximized values of power factor are one-order larger than that obtained by changing chemical composition, reflecting the clean nature of electrostatic doping.

  5. Kinetics of Factor X activation by the membrane-bound complex of Factor IXa and Factor VIIIa.

    PubMed

    Panteleev, Mikhail A; Saenko, Evgueni L; Ananyeva, Natalya M; Ataullakhanov, Fazoil I

    2004-08-01

    Intrinsic tenase consists of activated Factors IX (IXa) and VIII (VIIIa) assembled on a negatively charged phospholipid surface. In vivo, this surface is mainly provided by activated platelets. In vitro, phosphatidylcholine/phosphatidylserine vesicles are often used to mimic natural pro-coagulant membranes. In the present study, we developed a quantitative mathematical model of Factor X activation by intrinsic tenase. We considered two situations, when complex assembly occurs on either the membrane of phospholipid vesicles or the surface of activated platelets. On the basis of existing experimental evidence, the following mechanism for the complex assembly on activated platelets was suggested: (i) Factors IXa, VIIIa and X bind to their specific platelet receptors; (ii) bound factors form complexes on the membrane: platelet-bound Factor VIIIa provides a high-affinity site for Factor X and platelet-bound Factor IXa provides a high-affinity site for Factor VIIIa; (iii) the enzyme-cofactor-substrate complex is assembled. This mechanism allowed the explanation of co-operative effects in the binding of Factors IXa, VIIIa and X to platelets. The model was reduced to obtain a single equation for the Factor X activation rate as a function of concentrations of Factors IXa, VIIIa, X and phospholipids (or platelets). The equation had a Michaelis-Menten form, where apparent V(max) and K(m) were functions of the factors' concentrations and the internal kinetic constants of the system. The equation obtained can be used in both experimental studies of intrinsic tenase and mathematical modelling of the coagulation cascade. The approach of the present study can be applied to research of other membrane-dependent enzymic reactions.

  6. Power Factors that Define Gender Inequity within the Missouri Public School Superintendency

    ERIC Educational Resources Information Center

    Alexander, Kristina; Grispino, Frank D.; Messner, Phillip E.

    2004-01-01

    Although women have access to the superintendency power position, evidence has shown that women have not been able to consistently break the glass ceiling. A review of related literature failed to identify specific and practical employment factors that must be resolved or overcome if women are to reach power parity in Missouri. This study was…

  7. Hybrid PV/diesel solar power system design using multi-level factor analysis optimization

    NASA Astrophysics Data System (ADS)

    Drake, Joshua P.

    Solar power systems represent a large area of interest across a spectrum of organizations at a global level. It was determined that a clear understanding of current state of the art software and design methods, as well as optimization methods, could be used to improve the design methodology. Solar power design literature was researched for an in depth understanding of solar power system design methods and algorithms. Multiple software packages for the design and optimization of solar power systems were analyzed for a critical understanding of their design workflow. In addition, several methods of optimization were studied, including brute force, Pareto analysis, Monte Carlo, linear and nonlinear programming, and multi-way factor analysis. Factor analysis was selected as the most efficient optimization method for engineering design as it applied to solar power system design. The solar power design algorithms, software work flow analysis, and factor analysis optimization were combined to develop a solar power system design optimization software package called FireDrake. This software was used for the design of multiple solar power systems in conjunction with an energy audit case study performed in seven Tibetan refugee camps located in Mainpat, India. A report of solar system designs for the camps, as well as a proposed schedule for future installations was generated. It was determined that there were several improvements that could be made to the state of the art in modern solar power system design, though the complexity of current applications is significant.

  8. The influence of non-idealities on the thermoelectric power factor of nanostructured superlattices

    SciTech Connect

    Thesberg, Mischa; Pourfath, Mahdi; Kosina, Hans

    2015-12-14

    Cross-plane superlattices composed of nanoscale layers of alternating potential wells and barriers have attracted great attention for their potential to provide thermoelectric power factor improvements and higher ZT figure of merit. Previous theoretical works have shown that the presence of optimized potential barriers could provide improvements to the Seebeck coefficient through carrier energy filtering, which improves the power factor by up to 40%. However, experimental corroboration of this prediction has been extremely scant. In this work, we employ quantum mechanical electronic transport simulations to outline the detrimental effects of random variation, imperfections, and non-optimal barrier shapes in a superlattice geometry on these predicted power factor improvements. Thus, we aim to assess either the robustness or the fragility of these theoretical gains in the face of the types of variation one would find in real material systems. We show that these power factor improvements are relatively robust against: overly thick barriers, diffusion of barriers into the body of the wells, and random fluctuations in barrier spacing and width. However, notably, we discover that extremely thin barriers and random fluctuation in barrier heights by as little as 10% is sufficient to entirely destroy any power factor benefits of the optimized geometry. Our results could provide performance optimization routes for nanostructured thermoelectrics and elucidate the reasons why significant power factor improvements are not commonly realized in superlattices, despite theoretical predictions.

  9. The influence of non-idealities on the thermoelectric power factor of nanostructured superlattices

    NASA Astrophysics Data System (ADS)

    Thesberg, Mischa; Pourfath, Mahdi; Kosina, Hans; Neophytou, Neophytos

    2015-12-01

    Cross-plane superlattices composed of nanoscale layers of alternating potential wells and barriers have attracted great attention for their potential to provide thermoelectric power factor improvements and higher ZT figure of merit. Previous theoretical works have shown that the presence of optimized potential barriers could provide improvements to the Seebeck coefficient through carrier energy filtering, which improves the power factor by up to 40%. However, experimental corroboration of this prediction has been extremely scant. In this work, we employ quantum mechanical electronic transport simulations to outline the detrimental effects of random variation, imperfections, and non-optimal barrier shapes in a superlattice geometry on these predicted power factor improvements. Thus, we aim to assess either the robustness or the fragility of these theoretical gains in the face of the types of variation one would find in real material systems. We show that these power factor improvements are relatively robust against: overly thick barriers, diffusion of barriers into the body of the wells, and random fluctuations in barrier spacing and width. However, notably, we discover that extremely thin barriers and random fluctuation in barrier heights by as little as 10% is sufficient to entirely destroy any power factor benefits of the optimized geometry. Our results could provide performance optimization routes for nanostructured thermoelectrics and elucidate the reasons why significant power factor improvements are not commonly realized in superlattices, despite theoretical predictions.

  10. Factors associated with physical activity among young adults with a disability.

    PubMed

    Saebu, M; Sørensen, M

    2011-10-01

    The purpose of this study was to examine: (1) total physical activity and (2) the relative importance of functioning and disability, environmental and personal factors for total physical activity among young adults with a disability. The International Classification of Functioning, Disability and Health developed by the World Health Organization was used as a structural framework for a cross-sectional survey, based on a questionnaire. The population studied was 327 young adults (age 18-30) with a disability who were members of interest organizations for persons with disabilities. Using an adapted version of the self-administered short form of International Physical Activity Questionnaire (IPAQ), the sample reported some differences in physical activity related to the type and the onset of disability. Linear regression analyses revealed that personal factors demonstrated more power in explaining the variance in physical activity than both the environmental factors and factors related to functioning and disability. As for the able-bodied, intrinsic motivation and identity as an active person were the factors most strongly associated with physical activity behavior. This should have important consequences for how professionals try to motivate people with disabilities for physical activity, and how they plan and implement rehabilitation.

  11. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    PubMed

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  12. Photo-induced enhancement of the power factor of Cu2S thermoelectric films

    NASA Astrophysics Data System (ADS)

    Lv, Yanhong; Chen, Jikun; Zheng, Ren-Kui; Song, Junqiang; Zhang, Tiansong; Li, Xiaomin; Shi, Xun; Chen, Lidong

    2015-11-01

    Element doping is commonly used to adjust the carrier concentrations in semiconductors such as thermoelectric materials. However, the doping process unavoidably brings in defects or distortions in crystal lattices, which further strongly affects the physical properties of the materials. In this work, high energy photons have been used to activate the carriers in Cu2S thermoelectric films. As a result, the carrier concentrations, and the respective electrical conductivity as well as Seebeck coefficient are further changed. The photon-induced electrical transport properties are further analyzed utilizing a Parallel circuit model. Due to the realization of optimized carrier concentrations by photon activation, the power factor of Cu2S film is improved more than 900 times as compared with the dark data. As compared to the traditional doping process, the approach using photon activation can realize the tuning of carrier concentrations without affecting crystal lattice. This method provides an opportunity to investigate the intrinsic physical properties of semiconductor materials without involving traditional element doping process that usually brings in additional lattice defects or distortions.

  13. Photo-induced enhancement of the power factor of Cu2S thermoelectric films

    PubMed Central

    Lv, Yanhong; Chen, Jikun; Zheng, Ren-Kui; Song, Junqiang; Zhang, Tiansong; Li, Xiaomin; Shi, Xun; Chen, Lidong

    2015-01-01

    Element doping is commonly used to adjust the carrier concentrations in semiconductors such as thermoelectric materials. However, the doping process unavoidably brings in defects or distortions in crystal lattices, which further strongly affects the physical properties of the materials. In this work, high energy photons have been used to activate the carriers in Cu2S thermoelectric films. As a result, the carrier concentrations, and the respective electrical conductivity as well as Seebeck coefficient are further changed. The photon-induced electrical transport properties are further analyzed utilizing a Parallel circuit model. Due to the realization of optimized carrier concentrations by photon activation, the power factor of Cu2S film is improved more than 900 times as compared with the dark data. As compared to the traditional doping process, the approach using photon activation can realize the tuning of carrier concentrations without affecting crystal lattice. This method provides an opportunity to investigate the intrinsic physical properties of semiconductor materials without involving traditional element doping process that usually brings in additional lattice defects or distortions. PMID:26573407

  14. Photo-induced enhancement of the power factor of Cu2S thermoelectric films.

    PubMed

    Lv, Yanhong; Chen, Jikun; Zheng, Ren-Kui; Song, Junqiang; Zhang, Tiansong; Li, Xiaomin; Shi, Xun; Chen, Lidong

    2015-01-01

    Element doping is commonly used to adjust the carrier concentrations in semiconductors such as thermoelectric materials. However, the doping process unavoidably brings in defects or distortions in crystal lattices, which further strongly affects the physical properties of the materials. In this work, high energy photons have been used to activate the carriers in Cu2S thermoelectric films. As a result, the carrier concentrations, and the respective electrical conductivity as well as Seebeck coefficient are further changed. The photon-induced electrical transport properties are further analyzed utilizing a Parallel circuit model. Due to the realization of optimized carrier concentrations by photon activation, the power factor of Cu2S film is improved more than 900 times as compared with the dark data. As compared to the traditional doping process, the approach using photon activation can realize the tuning of carrier concentrations without affecting crystal lattice. This method provides an opportunity to investigate the intrinsic physical properties of semiconductor materials without involving traditional element doping process that usually brings in additional lattice defects or distortions. PMID:26573407

  15. Active CPW-fed slot antennas for power combining applications

    NASA Technical Reports Server (NTRS)

    Kormanyos, Brian K.; Rebeiz, Gabriel M.

    1992-01-01

    We have combined integrated circuit antenna technology with microwave oscillator design to build an active slot-oscillator. The design is planar, does not require via holes and is compatible with monolithic transistor technology. The CPW-fed antenna impedance is calculated using a full-wave analysis technique. Slot-oscillators were built at 7, 13, and 22 GHz, and the predicted oscillation frequencies agree well with experiments. The design is easily scaled to millimeter-wave frequencies and can be extended to power combining arrays.

  16. Experimental results using active control of traveling wave power flow

    NASA Technical Reports Server (NTRS)

    Miller, David W.; Hall, Steven R.

    1991-01-01

    Active structural control experiments conducted on a 24-ft pinned-free beam derived feedback compensators on the basis of a traveling-wave approach. A compensator is thus obtained which eliminates resonant behavior by absorbing all impinging power. A causal solution is derived for this noncausal compensator which mimics its behavior in a given frequency range, using the Wiener-Hopf. This optimal Wiener-Hopf compensator's structure-damping performance is found to exceed any obtainable by means of rate feedback. Performance limitations encompassed the discovery of frequencies above which the sensor and actuator were no longer dual and an inadvertent coupling of the control hardware to unmodeled structure torsion modes.

  17. A Wolf Pack Algorithm for Active and Reactive Power Coordinated Optimization in Active Distribution Network

    NASA Astrophysics Data System (ADS)

    Zhuang, H. M.; Jiang, X. J.

    2016-08-01

    This paper presents an active and reactive power dynamic optimization model for active distribution network (ADN), whose control variables include the output of distributed generations (DGs), charge or discharge power of energy storage system (ESS) and reactive power from capacitor banks. To solve the high-dimension nonlinear optimization model, a new heuristic swarm intelligent method, namely wolf pack algorithm (WPA) with better global convergence and computational robustness, is adapted so that the network loss minimization can be achieved. In this paper, the IEEE33-bus system is used to show the effectiveness of WPA technique compared with other techniques. Numerical tests on the modified IEEE 33-bus system show that WPA for active and reactive multi-period optimization of ADN is exact and effective.

  18. Carp thrombocyte phagocytosis requires activation factors secreted from other leukocytes.

    PubMed

    Nagasawa, Takahiro; Somamoto, Tomonori; Nakao, Miki

    2015-10-01

    Thrombocytes are nucleated blood cells in non-mammalian vertebrates, which were recently focused on not only as hemostatic cells but also as immune cells with potent phagocytic activities. We have analyzed the phagocytic activation mechanisms in common carp (Cyprinus carpio) thrombocytes. MACS-sorted mAb(+) thrombocytes showed no phagocytic activity even in the presence of several stimulants. However, remixing these thrombocytes with other anti-thrombocyte mAb(-) leukocyte populations restored their phagocytic activities, indicating that carp thrombocyte phagocytosis requires an appropriate exogenous stimulation. Culture supernatant from anti-thrombocyte mAb(-) leukocytes harvested after PMA or LPS stimulation, but not culture supernatant from unstimulated leukocytes, could activate thrombocyte phagocytosis. This proposed mechanism of thrombocyte phagocytosis activation involving soluble factors produced by activated leukocytes suggests that thrombocyte activation is restricted to areas proximal to injured tissues, ensuring suppression of excessive thrombocyte activation and a balance between inflammation and tissue repair.

  19. Active energy harvesting from microbial fuel cells at the maximum power point without using resistors.

    PubMed

    Wang, Heming; Park, Jae-Do; Ren, Zhiyong

    2012-05-01

    Microbial fuel cell (MFC) technology offers a sustainable approach to harvest electricity from biodegradable materials. Energy production from MFCs has been demonstrated using external resistors or charge pumps, but such methods can only dissipate energy through heat or receive electrons passively from the MFC without any controllability. This study developed a new approach and system that can actively extract energy from MFC reactors at any operating point without using any resistors, especially at the peak power point to maximize energy production. Results show that power harvesting from a recirculating-flow MFC can be well maintained by the maximum power point circuit (MPPC) at its peak power point, while a charge pump was not able to change operating point due to current limitation. Within 18-h test, the energy gained from the MPPC was 76.8 J, 76 times higher than the charge pump (1.0 J) that was commonly used in MFC studies. Both conditions resulted in similar organic removal, but the Coulombic efficiency obtained from the MPPC was 21 times higher than that of the charge pump. Different numbers of capacitors could be used in the MPPC for various energy storage requirements and power supply, and the energy conversion efficiency of the MPPC was further characterized to identify key factors for system improvement. This active energy harvesting approach provides a new perspective for energy harvesting that can maximize MFC energy generation and system controllability.

  20. Metal clad active fibres for power scaling and thermal management at kW power levels.

    PubMed

    Daniel, Jae M O; Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John

    2016-08-01

    We present a new approach to high power fibre laser design, consisting of a polymer-free all-glass optical fibre waveguide directly overclad with a high thermal conductivity metal coating. This metal clad active fibre allows a significant reduction in thermal resistance between the active fibre and the laser heat-sink as well as a significant increase in the operating temperature range. In this paper we show the results of a detailed thermal analysis of both polymer and metal coated active fibres under thermal loads typical of kW fibre laser systems. Through several different experiments we present the first demonstration of a cladding pumped aluminium-coated fibre laser and the first demonstration of efficient operation of a cladding-pumped fibre laser at temperatures of greater than 400 °C. Finally, we highlight the versatility of this approach through operation of a passively (radiatively) cooled ytterbium fibre laser head at an output power of 405 W in a compact and ultralight package weighing less than 100 g. PMID:27505822

  1. Comprehensive review of high power factor ac-dc boost converters for PFC applications

    NASA Astrophysics Data System (ADS)

    De Castro Pereira, Dênis; Da Silva, Márcio Renato; Mateus Silva, Elder; Lessa Tofoli, Fernando

    2015-08-01

    High power factor rectifiers have been consolidated as an effective solution to improve power quality indices in terms of input power factor correction, reduction in the total harmonic distortion of the input current and also regulated dc voltages. Within this context, this subject has motivated the introduction of numerous converter topologies based on classic dc-dc structures associated with novel control techniques, thus leading to the manufacturing of dedicated integrated circuits that allow high input power factor by adding a front-end stage to switch-mode converters. In particular, boost converters in continuous current mode (CCM) are widely employed since they allow obtaining minimised electromagnetic interference levels. This work is concerned with a literature review involving relevant ac-dc single-phase boost-based topologies with high input power factor. The evolution of aspects regarding the conventional boost converter is shown in terms of improved characteristics inherent to other ac-dc boost converters. Additionally, the work intends to be a fast and concise reference to single-phase ac-dc boost converters operating in CCM for engineers, researchers and experts in the field of power electronics by properly analysing and comparing the aforementioned rectifiers.

  2. Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

    SciTech Connect

    Sakai, T.; Kisiel, W. )

    1990-11-01

    Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which {sup 125}I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity.

  3. Low-power laser irradiation (LPLI) attenuates microglial cytotoxicity through the activation of Src pathway

    NASA Astrophysics Data System (ADS)

    Song, Sheng; Zhou, Feifan; Chen, Wei R.

    2014-02-01

    It has been known for a long time that microglial activation plays an important role in the pathology of neurodegenerative diseases. Once activated, they have macrophage-like capabilities, which can be detrimental by producing proinflammatory and neurotoxic factors including cytokines, reactive oxygen species (ROS) and nitric oxide that directly or indirectly cause neurodegeneration. Therefore, the regulation of microglial-induced neuroinflammation is considered a useful strategy in searching for neuroprotective treatments. In this study, our results showed that low power laser irradiation (LPLI) (20 J/cm2) could suppress microglial-induced neuroinflammation in LPS-activated microglia. We found that LPLI-mediated neuroprotection was achieved by activating tyrosine kinases Src, which led to MyD88 tyrosine phosphorylation, thus impairing MyD88-dependent proinflammatory signaling cascade. Our research may provide a feasible therapeutic approach to control the progression of neurodegenerative diseases.

  4. Changes in CVD risk factors in the activity counseling trial

    PubMed Central

    Baruth, Meghan; Wilcox, Sara; Sallis, James F; King, Abby C; Marcus, Bess H; Blair, Steven N

    2011-01-01

    Primary care facilities may be a natural setting for delivering interventions that focus on behaviors that improve cardiovascular disease (CVD) risk factors. The purpose of this study was to examine the 24-month effects of the Activity Counseling Trial (ACT) on CVD risk factors, to examine whether changes in CVD risk factors differed according to baseline risk factor status, and to examine whether changes in fitness were associated with changes in CVD risk factors. ACT was a 24-month multicenter randomized controlled trial to increase physical activity. Participants were 874 inactive men and women aged 35–74 years. Participants were randomly assigned to one of three arms that varied by level of counseling, intensity, and resource requirements. Because there were no significant differences in change over time between arms on any of the CVD risk factors examined, all arms were combined, and the effects of time, independent of arm, were examined separately for men and women. Time × Baseline risk factor status interactions examined whether changes in CVD risk factors differed according to baseline risk factor status. Significant improvements in total cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol, the ratio of total cholesterol to HDL-C, and triglycerides were seen in both men and women who had high (or low for HDL-C) baseline levels of risk factors, whereas significant improvements in diastolic blood pressure were seen only in those men with high baseline levels. There were no improvements in any risk factors among participants with normal baseline levels. Changes in fitness were associated with changes in a number of CVD risk factors. However, most relationships disappeared after controlling for changes in body weight. Improvements in lipids from the ACT interventions could reduce the risk of coronary heart disease in people with already high levels of lipids by 16%–26% in men and 11%–16% in women

  5. Totem-Pole Power-Factor-Correction Converter under Critical-Conduction-Mode Interleaved Operation

    NASA Astrophysics Data System (ADS)

    Firmansyah, Eka; Tomioka, Satoshi; Abe, Seiya; Shoyama, Masahito; Ninomiya, Tamotsu

    This paper proposes a new power-factor-correction (PFC) topology, and explains its operation principle, its control mechanism, related application problems followed by experimental results. In this proposed topology, critical-conduction-mode (CRM) interleaved technique is applied to a bridgeless PFC in order to achieve high efficiency by combining benefits of each topology. This application is targeted toward low to middle power applications that normally employs continuous-conduction-mode boost converter.

  6. The suppression of star formation by powerful active galactic nuclei.

    PubMed

    Page, M J; Symeonidis, M; Vieira, J D; Altieri, B; Amblard, A; Arumugam, V; Aussel, H; Babbedge, T; Blain, A; Bock, J; Boselli, A; Buat, V; Castro-Rodríguez, N; Cava, A; Chanial, P; Clements, D L; Conley, A; Conversi, L; Cooray, A; Dowell, C D; Dubois, E N; Dunlop, J S; Dwek, E; Dye, S; Eales, S; Elbaz, D; Farrah, D; Fox, M; Franceschini, A; Gear, W; Glenn, J; Griffin, M; Halpern, M; Hatziminaoglou, E; Ibar, E; Isaak, K; Ivison, R J; Lagache, G; Levenson, L; Lu, N; Madden, S; Maffei, B; Mainetti, G; Marchetti, L; Nguyen, H T; O'Halloran, B; Oliver, S J; Omont, A; Panuzzo, P; Papageorgiou, A; Pearson, C P; Pérez-Fournon, I; Pohlen, M; Rawlings, J I; Rigopoulou, D; Riguccini, L; Rizzo, D; Rodighiero, G; Roseboom, I G; Rowan-Robinson, M; Sánchez Portal, M; Schulz, B; Scott, D; Seymour, N; Shupe, D L; Smith, A J; Stevens, J A; Trichas, M; Tugwell, K E; Vaccari, M; Valtchanov, I; Viero, M; Vigroux, L; Wang, L; Ward, R; Wright, G; Xu, C K; Zemcov, M

    2012-05-09

    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlation between the mass of the black hole and the mass of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming galaxies are usually dust-obscured and are brightest at infrared and submillimetre wavelengths. Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10(44) ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow, expelling the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

  7. Hydrogen as an activating fuel for a tidal power plant

    NASA Astrophysics Data System (ADS)

    Gorlov, A. M.

    Tidal projects, offering a clean, inexhaustible, and fairly predictable energy source, require a system for accumulating energy for off-peak periods. Hydrogen produced by electrolysis during off-peak power plant operation can be used as an activating fuel to furnish the plant during peak load demands. Tidal energy is converted into compressed air energy by special chambers on the ocean bed. This compressed air can be heated by combustion of the stored hydrogen and expanded through high speed gas turbine generators. For off-peak periods, the energy of non-heated compressed air is used for the production of hydrogen fuel. The amount of fuel produced at this time is enough for power plant operation during two peak hours, with three times greater plant capacity. The hydrogen fuel storage method does have energy losses and requires extra capital investment for electrolysis and hydrogen storage equipment. It does not, however, require a gas turbine oil fuel, as does the air compressed storage method, nor a low-speed heavy hydro-turbine, as does the hydro-pumped method. Moreover, the gas turbine can be used for both production and consumption of hydrogen fuel.

  8. The Suppression of Star Formation by Powerful Active Galactic Nuclei

    NASA Technical Reports Server (NTRS)

    Dwek, E.

    2012-01-01

    The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight corre1ation between the mass of the black hole and the mas. of the stellar bulge results from the AGN quenching the surrounding star formation as it approaches its peak luminosity. X-rays trace emission from AGN unambiguously, whereas powerful star-forming ga1axies are usually dust-obscured and are brightest at infrared and submillimeter wavelengths. Here we report submillimetre and X-ray observations that show that rapid star formation was common in the host galaxies of AGN when the Universe was 2-6 billion years old, but that the most vigorous star formation is not observed around black holes above an X-ray luminosity of 10(exp 44) ergs per second. This suppression of star formation in the host galaxy of a powerful AGN is a key prediction of models in which the AGN drives an outflow, expe11ing the interstellar medium of its host and transforming the galaxy's properties in a brief period of cosmic time.

  9. Factors limiting microbial activity in volcanic tuff at Yucca Mountain

    SciTech Connect

    Kieft, T.L.; Kovacik, W.P.; Taylor, J.

    1996-09-01

    Samples of tuff aseptically collected from 10 locations in the Exploratory Shaft Facility at the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada Test Site were analyzed for microbiological populations, activities, and factors limiting microbial activity. Radiotracer assays ({sup 14}C-labeled organic substrate mineralization), direct microscopic counts, and plate counts were used. Radiolabeled substrates were glucose, acetate, and glutamate. Radiotracer experiments were carried out with and without moisture and inorganic nutrient amendments to determine factors limiting to microbial activities. Nearly all samples showed the presence of microorganisms with the potential to mineralize organic substrates. Addition of inorganic nutrients stimulated activities in a small number of samples. The presence of viable microbial communities within the tuff has implications for transport of contaminants.

  10. Factor H-related proteins determine complement-activating surfaces.

    PubMed

    Józsi, Mihály; Tortajada, Agustin; Uzonyi, Barbara; Goicoechea de Jorge, Elena; Rodríguez de Córdoba, Santiago

    2015-06-01

    Complement factor H-related proteins (FHRs) are strongly associated with different diseases involving complement dysregulation, which suggests a major role for these proteins regulating complement activation. Because FHRs are evolutionarily and structurally related to complement inhibitor factor H (FH), the initial assumption was that the FHRs are also negative complement regulators. Whereas weak complement inhibiting activities were originally reported for these molecules, recent developments indicate that FHRs may enhance complement activation, with important implications for the role of these proteins in health and disease. We review these findings here, and propose that FHRs represent a complex set of surface recognition molecules that, by competing with FH, provide improved discrimination of self and non-self surfaces and play a central role in determining appropriate activation of the complement pathway.

  11. Performance Prediction of Active Piezo Fiber Rackets in Terms of Tennis Power

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Takeda, Yukihiro; Nakagawa, Masamichi

    Several former top players sent a letter to the International Tennis Federation (ITF) encouraging the governing body to revisit the question of rackets. In the letter, the players wrote that racket technology has led to major changes in how the game is played at the top level. This paper investigated the physical properties of a new type of racket with active piezoelectric fibers appeared recently in the market, and predicted the various factors associated with the frontal impact, such as impact force, contact time, deformation of ball and strings, and also estimated the racket performance such as the coefficient of restitution, the rebound power coefficient, the post-impact ball velocity and the sweet areas relevant to the power in tennis. It is based on the experimental identification of the dynamics of the ball-racket-arm system and the approximate nonlinear impact analysis with a simple swing model. The predicted results with forehand stroke model can explain the difference in mechanism of performance between the new type racket with active piezoelectric fibers and the conventional passive representative rackets. It showed that this new type racket provides higher coefficient of restitution on the whole area of string face and also gives larger rebound power coefficients particularly at the topside and bigger powers on the whole area of string face but the difference was not so large. It seems that the racket-related improvements in play are relatively small and the players themselves continue to improve, accordingly there is a gap between a perception and reality.

  12. The site of activation of factor X by cancer procoagulant.

    PubMed

    Gordon, S G; Mourad, A M

    1991-12-01

    Cancer procoagulant (CP) is a cysteine proteinase found in a variety of malignant cells and tissues and in human amnion-chorion tissue. It initiates coagulation by activating factor X. However, the amino acid sequence of the substrate protein that determines the cleavage site of cysteine proteinases is different from that of the serine proteinases that normally activate factor X, such as factor IXa, VIIa and Russell's Viper Venom (RVV). Therefore, it was of interest to determine the site of cleavage of human factor X by CP. Purified CP was incubated with purified factor X and the reaction mixture was electrophoresed on a 10% Tris-tricine SDS-PAGE gel. The proteins were electroeluted on to a polyvinylidene difluoride (PVDF) membrane, and stained with Coomassie blue. The heavy chain of activated factor X was cut out of the PVDF membrane and sequenced with an Applied Biosystems 477A with on-line HPLC. The primary cleavage sequence was Asp-Ala-Ala-Asp-Leu-Asp-Pro-; two other secondary sequences Ser-Ile-Thr-Trp-Lys-Pro- and Glu-Asn-Pro-Phe-Asp-Leu were found. The penultimate amino acid on the carbonyl side of the hydrolysed amide bond plays a critical role for the recognition of the cleavage site of cysteine proteinases. These data indicate that the penultimate amino acid for the primary cleavage site of factor X by CP is proline-20 and for the secondary sites, proline-13 and proline-28. This is in contrast to arginine-52 that determines the specificity of the cleavage by normal serine proteinase activation.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Factors Associated with Early Platelet Activation in Obese Children

    PubMed Central

    García, Anel Gómez; Núñez, Guillermina García; Sandoval, Martha Eva Viveros; Castellanos, Sergio Gutierrez; Aguilar, Cleto Alvarez

    2014-01-01

    Objective To investigate the factors associated with platelet activation in obese children. Design Cross-sectional study. Setting Department of Pediatrics of Regional Hospital N∘ 1 of Mexican Institute of Social Security in Morelia, Michoacán, Mexico. Participants 79 obese and 64 non-obese children between the ages of 5 and 10 years. Main Outcomes Measures Obese children (body mass index [BMI] >85 in growth curves for Centers for Disease Control/National Center for Health Statistics), and the control group of 64 non-obese children (percentile <85), % body fat, platelet activation was assessed by sP-selectin. Other measures were leptin, uric acid (UA), von Willebrand Factor (vWF), plasminogen activator inhibitor (PAI-1), lipid profile, and glucose. Results Obese children displayed higher plasma sP-selectin, leptin, PAI-1, and vWF than non-obese children. In the univariate logistic regression analysis, leptin, vWF, UA, and high density lipoprotein (HDL), but not with PAI-1, were factors associated with platelet activation. By stepwise linear regression analysis adjusted by sex and age, the best predictor variables for platelet activation were leptin (β:0.381; t:4.665; P=0.0001), vWF (β:0.211; t:2.926; P=0.004), UA (β:0.166; t:2.146; P=0.034), and HDL (β:−0.215; t:−2.819; P=0.006). Conclusions Obese children have a higher risk of developing early platelet activation. Factors associated with platelet activation were Leptin, vWF, UA, and HDL. Further studies involving larger numbers of patients over a longer duration are needed to understand the possible molecular mechanism underlying the association between leptin, vWF, and UA and endothelial activation and/or endothelial damage/dysfunction in obese children and its influence in cardiovascular disease in adults. PMID:24415745

  14. Evaluation of induction motor performance using an electronic power factor controller

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The concept of reducing the losses in an induction motor by electronically controlling the time interval between the zero crossing of the applied voltage and the zero crossing of the armature current was evaluated. The effect on power losses and power factor of reducing the applied sinusoidal voltages below the rated value was investigated experimentally. The reduction in power losses was measured using an electronic controller designed and built at MSFC. Modifications to the MSFC controller are described as well as a manually controlled electronic device which does not require that the motor be wye connected and the neutral available. Possible energy savings are examined.

  15. Reliability of IGBT in a STATCOM for Harmonic Compensation and Power Factor Correction

    SciTech Connect

    Gopi Reddy, Lakshmi Reddy; Tolbert, Leon M; Ozpineci, Burak; Xu, Yan; Rizy, D Tom

    2012-01-01

    With smart grid integration, there is a need to characterize reliability of a power system by including reliability of power semiconductors in grid related applications. In this paper, the reliability of IGBTs in a STATCOM application is presented for two different applications, power factor correction and harmonic elimination. The STATCOM model is developed in EMTP, and analytical equations for average conduction losses in an IGBT and a diode are derived and compared with experimental data. A commonly used reliability model is used to predict reliability of IGBT.

  16. Physical Activity in Adolescents following Treatment for Cancer: Influencing Factors.

    PubMed

    Wright, Marilyn; Bryans, Angie; Gray, Kaylin; Skinner, Leah; Verhoeve, Amanda

    2013-01-01

    The purpose of this study was to examine physical activity levels and influencing individual and environmental factors in a group of adolescent survivors of cancer and a comparison group. Methods. The study was conducted using a "mixed methods" design. Quantitative data was collected from 48 adolescent survivors of cancer and 48 comparison adolescents using the Godin Leisure-Time Exercise Questionnaire, the Fatigue Scale-Adolescents, and the Amherst Health and Activity Study-Student Survey. Qualitative data was collected in individual semistructured interviews. Results. Reported leisure-time physical activity total scores were not significantly different between groups. Physical activity levels were positively correlated with adult social support factors in the group of adolescent survivors of cancer, but not in the comparison group. Time was the primary barrier to physical activity in both groups. Fatigue scores were higher for the comparison but were not associated with physical activity levels in either group. The qualitative data further supported these findings. Conclusions. Barriers to physical activity were common between adolescent survivors of cancer and a comparative group. Increased knowledge of the motivators and barriers to physical activity may help health care providers and families provide more effective health promotion strategies to adolescent survivors of pediatric cancer.

  17. Variation in Rubisco content and activity under variable climatic factors.

    PubMed

    Galmés, Jeroni; Aranjuelo, Iker; Medrano, Hipólito; Flexas, Jaume

    2013-11-01

    The main objective of the present review is to provide a compilation of published data of the effects of several climatic conditions on Rubisco, particularly its activity, state of activation, and concentration, and its influence on leaf gas exchange and photosynthesis. The environmental conditions analyzed include drought, salinity, heavy metals, growth temperature, and elevated [O3], [CO2], and ultraviolet-B irradiance. The results show conclusive evidence for a major negative effect on activity of Rubisco with increasing intensity of a range of abiotic stress factors. This decrease in the activity of Rubisco is associated with down-regulation of the activation state of the enzyme (e.g., by de-carbamylation and/or binding of inhibitory sugar phosphates) in response to drought or high temperature. On the contrary, the negative effects of low temperature, heavy metal stress (cadmium), ozone, and UV-B stress on Rubisco activity are associated with changes in the concentration of Rubisco. Notably, in response to all environmental factors, the regulation of in vivo CO2 assimilation rate was related to Rubisco in vitro parameters, either concentration and/or carboxylation, depending on the particular stress. The importance of the loss of Rubisco activity and its repercussion on plant photosynthesis are discussed in the context of climate change. It is suggested that decreased Rubisco activity will be a major effect induced by climate change, which will need to be considered in any prediction model on plant productivity in the near future.

  18. The Relevant Factors in Promoting Reading Activities in Elementary Schools

    ERIC Educational Resources Information Center

    Huang, Han-Chen; Tsai, Yao-Hsu; Huang, Shih-Hsiang

    2015-01-01

    In order to help students absorb knowledge, schools often conduct reading activities. Thorough planning and strategies, however, are needed to insure the effect of reading promotions, and make them a deeply-rooted part of life. This study adopted the analytic hierarchy process (AHP) to discuss the relevant factors in promoting reading activities…

  19. Factors Influencing Teachers' Engagement in Informal Learning Activities

    ERIC Educational Resources Information Center

    Lohman, Margaret C.

    2006-01-01

    Purpose: The purpose of this study is to examine factors influencing the engagement of public school teachers in informal learning activities. Design/methodology/approach: This study used a survey research design. Findings: Analysis of the data found that teachers rely to a greater degree on interactive than on independent informal learning…

  20. Total Chemical Synthesis of Biologically Active Vascular Endothelial Growth Factor

    SciTech Connect

    Mandal, Kalyaneswar; Kent, Stephen B.H.

    2011-09-15

    The 204-residue covalent-dimer vascular endothelial growth factor (VEGF, see picture) with full mitogenic activity was prepared from three unprotected peptide segments by one-pot native chemical ligations. The covalent structure of the synthetic VEGF was confirmed by precise mass measurement, and the three-dimensional structure of the synthetic protein was determined by high-resolution X-ray crystallography.

  1. Improved Power Conversion Efficiency of Inverted Organic Solar Cells by Incorporating Au Nanorods into Active Layer.

    PubMed

    He, Yeyuan; Liu, Chunyu; Li, Jinfeng; Zhang, Xinyuan; Li, Zhiqi; Shen, Liang; Guo, Wenbin; Ruan, Shengping

    2015-07-29

    This Research Article describes a cooperative plasmonic effect on improving the performance of organic solar cells. When Au nanorods(NRs) are incorporated into the active layers, the designed project shows superior enhanced light absorption behavior comparing with control devices, which leads to the realization of organic solar cell with power conversion efficiency of 6.83%, accounting for 18.9% improvement. Further investigations unravel the influence of plasmonic nanostructures on light trapping, exciton generation, dissociation, and charge recombination and transport inside the thin films devices. Moreover, the introduction of high-conductivity Au NRs improves electrical conductivity of the whole device, which contributes to the enhanced fill factor.

  2. Active tissue factor and activated factor XI in circulating blood of patients with systolic heart failure due to ischemic cardiomyopathy

    PubMed Central

    Zabczyk, Michał; Butenas, Saulius; Palka, Ilona; Nessler, Jadwiga; Undas, Anetta

    2011-01-01

    INTRODUCTION Elevated clotting factors and thrombin generation have been reported to occur in patients with heart failure (HF). Circulating activated factor XI (FXIa) and active tissue factor (TF) can be detected in acute coronary syndromes and stable angina. OBJECTIVES We investigated circulating FXIa and active TF and their associations in patients with systolic HF due to ischemic cardiomyopathy. PATIENTS AND METHODS In an observational study, we assessed 53 consecutive patients, aged below 75 years, with stable HF associated with documented coronary artery disease (CAD). Atrial fibrillation (LA), recent thromboembolic events, and current anticoagulant therapy were the exclusion criteria. Plasma TF and FXIa activity was determined in clotting assays by measuring the response to inhibitory monoclonal antibodies. RESULTS Coagulant TF activity was detected in 20 patients (37.7%), and FXIa in 22 patients (41.5%). Patients with detectable TF activity and/or FXIa were younger, had a history of myocardial infarction more frequently, significantly higher F1+2 prothrombin fragments, larger LA and right ventricular diastolic diameter, and higher right ventricular systolic pressure than the remaining subjects (P ≤0.01 for all). Circulating FXIa was positively correlated with F1+2 levels (r = 0.69; P <0.001). CONCLUSIONS Circulating active TF and FXIa occurred in about 40% of patients with systolic HF due to ischemic cardiomyopathy. The presence of these factors was associated with enhanced thrombin formation. Associations between both factors and LA diameter and right ventricular parameters might suggest that TF and FXIa predispose to thromboembolic complications of HF. PMID:20864906

  3. Factors that affect the fatigue strength of power transmission shafting and their impact on design

    NASA Technical Reports Server (NTRS)

    Leowenthal, S. H.

    1986-01-01

    A long standing objective in the design of power transmission shafting is to eliminate excess shaft material without compromising operational reliability. A shaft design method is presented which accounts for variable amplitude loading histories and their influence on limited life designs. The effects of combined bending and torsional loading are considered along with a number of application factors known to influence the fatigue strength of shafting materials. Among the factors examined are surface condition, size, stress concentration, residual stress and corrosion fatigue.

  4. Psychosocial Factors and Theory in Physical Activity Studies in Minorities

    PubMed Central

    Mama, Scherezade K.; McNeill, Lorna H.; McCurdy, Sheryl A.; Evans, Alexandra E.; Diamond, Pamela M.; Adamus-Leach, Heather J.; Lee, Rebecca E.

    2015-01-01

    Objectives To summarize the effectiveness of interventions targeting psychosocial factors to increase physical activity (PA) among ethnic minority adults and explore theory use in PA interventions. Methods Studies (N = 11) were identified through a systematic review and targeted African American/Hispanic adults, specific psychosocial factors, and PA. Data were extracted using a standard code sheet and the Theory Coding Scheme. Results Social support was the most common psychosocial factor reported, followed by motivational readiness, and self-efficacy, as being associated with increased PA. Only 7 studies explicitly reported using a theoretical framework. Conclusions Future efforts should explore theory use in PA interventions and how integration of theoretical constructs, including psychosocial factors, increases PA. PMID:25290599

  5. Analysis and design of modular three-phase power factor correction schemes for utility interface

    NASA Astrophysics Data System (ADS)

    Hahn, Jae-Hong

    The extensive use of non-linear and electronically switched loads in power system has lead to higher incidences of harmonic distortion of the voltage and current waveforms. Harmonic currents degrade power quality and are considered the main source of many system malfunctions. Technical guidelines and standards regarding suppressions of system harmonic contents have been enacted. This dissertation proposes several new three-phase power factor correction (PFC) schemes using single-phase PFC modules. An integrated single-switch approach is first proposed. This is essentially an add-on solution to standard ASD's. This approach is based on circulating third harmonic current between neutral and DC mid-point by utilizing a lossless resistor. Single-phase PFC emulates this resistor to control the amplitude of the current, which is implemented by the dynamic breaking chopper available in standard adjustable speed drives (ASD's). This approach is also capable of reducing harmonic distortion in multiple drives. Analysis, design and simulations are conducted to determine the performance of the proposed scheme with different line impedances and with and without dc-link inductance in the ASD. Experimental results are presented using commercial ASD retrofitted with the proposed approach. Second scheme proposes a three-phase PFC using two standard single-phase PFC modules. In this approach, three-phase input is transformed into two-phase by means of 0.14 pu autotransformer. Two standard single-phase PFC modules are employed to process two-phase power to do output. Split inductors and diodes are employed to limit the interaction between the two phases. A method to eliminate the interaction between phases is also described. Due to cascade operation of two PFC stages, low frequency (120Hz) ripple in dc-link is cancelled. An active interphase transformer (IPT) scheme is proposed to draw sinusoidal input line currents, in the third study. This scheme utilizes a unique combination of a

  6. Experimental design of a fuzzy controller for improving power factor of boost rectifier

    NASA Astrophysics Data System (ADS)

    Kessal, Abdelhalim; Rahmani, Lazhar; Gaubert, Jean-Paul; Mostefai, Mohammed

    2012-12-01

    This article presents the design and the implementation of dSPACE DS1104 controller board-based PI and fuzzy logic peak current-mode controllers in the voltage loop and two controllers in the current loop based first on a standard fixed hysteresis band control, followed by a variable hysteresis band control to achieve constant switching frequency for a single-phase active power factor corrector in the continuous conduction mode. All these controllers have been verified via simulation in Simulink and a real-time implementation is performed on an experimental test bench utilising a rapid prototyping tool. The controllers are experimentally compared for steady-state performance and transient response. It is shown that the PI and fuzzy logic controllers give a superior steady-state performance, whereas the fuzzy logic inference based controller can achieve better dynamic response than its PI counterpart under large load disturbance and plant uncertainties. Furthermore, the variable hysteresis band control in the current loop gives a low total harmonic distortion of the input current compared to a standard fixed hysteresis band control.

  7. Factors influencing efficiency of laser wireless power transmission system for micro unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoguang; Hua, Wenshen; Liu, Xun

    2014-12-01

    Micro unmanned aerial vehicle, mostly powered by electricity, plays an important role in many military and civil applications, e.g. military detection, communication relay et al. But restricted endurance ability severely limits its applications. To solve the problem, laser wireless power transmission system is proposed. However, overall efficiency of the system is quite low. This paper describes basic structure of laser wireless power transmission system and its working process. The system consists of two major modules: a high power laser source transmitting energy and a photovoltaic receiver converting optical energy into electricity. Then factors influencing efficiency of the system are analyzed. It suggests that electro-optical efficiency of laser, atmospheric impact on laser beam and photo-electric efficiency of photovoltaic receiver play significant role in overall efficiency of the system. Atmospheric impact on laser beam mostly derived from refraction, absorption, scattering and turbulence effects, leads to drop in energy and quality of laser beam. Efficiency of photovoltaic receiver is affected by photovoltaic materials. In addition, matching degree between intensity distribution of laser beam and layout of photovoltaic receiver also obviously influence efficiency of photovoltaic receiver. Experiment results suggest that under non-uniform laser beam illumination, efficiency of photovoltaic receiver mostly depends on layout of photovoltaic receiver. Through optimizing the layout of photovoltaic receiver based on intensity distribution of laser beam, output power is significantly improved. The analysis may help to take corresponding measures to alleviate negative effects of these factors and improve performance of laser wireless power transmission system.

  8. Ultrahigh-Power-Factor Carbon Nanotubes and an Ingenious Strategy for Thermoelectric Performance Evaluation.

    PubMed

    Zhou, Wenbin; Fan, Qingxia; Zhang, Qiang; Li, Kewei; Cai, Le; Gu, Xiaogang; Yang, Feng; Zhang, Nan; Xiao, Zhuojian; Chen, Huiliang; Xiao, Shiqi; Wang, Yanchun; Liu, Huaping; Zhou, Weiya; Xie, Sishen

    2016-07-01

    An ingenious strategy is put forward to evaluate accurately the thermoelectric performance of carbon nanotube (CNT) thin films, including thermal conductivity, electrical conductivity, and Seebeck coefficient in the same direction. The results reveal that the as-prepared CNT interconnected films and CNT fibers possess enormous potential of thermoelectric applications because of their ultrahigh power factors. PMID:27199099

  9. An accelerated ordered subsets reconstruction algorithm using an accelerating power factor for emission tomography

    NASA Astrophysics Data System (ADS)

    Hsiao, Ing-Tsung; Huang, Hsuan-Ming

    2010-02-01

    We proposed a speed-enhanced tomographic reconstruction algorithm, ACOSEM (accelerated complete-data ordered-subset expectation-maximization), to accelerate a convergent OS-type algorithm (COSEM). The ACOSEM algorithm was based on modification of the COSEM update by applying an accelerating power factor or a bigger step size. Unlike the limited enhancement of the other speed-enhanced algorithm (E-COSEM), the proposed ACOSEM with an appropriate power factor can lead to a much faster reconstruction speed than COSEM and ECOSEM. Similar to COSEM, there is no free user-entered relaxation parameter needed for ACOSEM to ensure the convergent performance as required in the other type of fast convergent algorithms such as RAMLA. We derived the ACOSEM algorithm, and compared its performance to those of other fast convergent algorithms including COSEM, ECOSEM and RAMLA with optimized relaxation parameters. Though not convergent, OSEM is the current state-of-the-art reconstruction method used in the clinics, and thus included in the noise performance comparison. The results showed that ACOSEM reached the same image quality as in COSEM but two times faster when a power factor of 2.0 was used. An upper limit of 5 for the power factor with monotonically increasing log-likelihood in ACOSEM was observed under various conditions. Although the convergence proof is not available now, the results of log-likelihood values and noise studies showed that ACOSEM performed consistently with COSEM but with an accelerating reconstruction speed.

  10. LPS-inducible factor(s) from activated macrophages mediates cytolysis of Naegleria fowleri amoebae

    SciTech Connect

    Cleary, S.F.; Marciano-Cabral, F.

    1986-03-01

    Soluble cytolytic factors of macrophage origin have previously been described with respect to their tumoricidal activity. The purpose of this study was to investigate the mechanism and possible factor(s) responsible for cytolysis of the amoeba Naegleria fowleri by activated peritoneal macrophages from B6C3F1 mice. Macrophages or conditioned medium (CM) from macrophage cultures were incubated with /sup 3/H-Uridine labeled amoebae. Percent specific release of label served as an index of cytolysis. Bacille Calmette-Guerin (BCG) and Corynebacterium parvum macrophages demonstrated significant cytolysis of amoebae at 24 h with an effector to target ratio of 10:1. Treatment of macrophages with inhibitors of RNA or protein synthesis blocked amoebicidal activity. Interposition of a 1 ..mu..m pore membrane between macrophages and amoebae inhibited killing. Inhibition in the presence of the membrane was overcome by stimulating the macrophages with LPS. CM from SPS-stimulated, but not unstimulated, cultures of activated macrophages was cytotoxic for amoebae. The activity was heat sensitive and was recovered from ammonium sulfate precipitation of the CM. Results indicate that amoebicidal activity is mediated by a protein(s) of macrophage origin induced by target cell contact or stimulation with LPS.

  11. HUBBLE CAPTURES AN EXTRAORDINARY AND POWERFUL ACTIVE GALAXY

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Resembling a swirling witch's cauldron of glowing vapors, the black hole-powered core of a nearby active galaxy appears in this colorful NASA Hubble Space Telescope image. The galaxy lies 13 million light-years away in the southern constellation Circinus. This galaxy is designated a type 2 Seyfert, a class of mostly spiral galaxies that have compact centers and are believed to contain massive black holes. Seyfert galaxies are themselves part of a larger class of objects called Active Galactic Nuclei or AGN. AGN have the ability to remove gas from the centers of their galaxies by blowing it out into space at phenomenal speeds. Astronomers studying the Circinus galaxy are seeing evidence of a powerful AGN at the center of this galaxy as well. Much of the gas in the disk of the Circinus spiral is concentrated in two specific rings -- a larger one of diameter 1,300 light-years, which has already been observed by ground-based telescopes, and a previously unseen ring of diameter 260 light-years. In the Hubble image, the smaller inner ring is located on the inside of the green disk. The larger outer ring extends off the image and is in the plane of the galaxy's disk. Both rings are home to large amounts of gas and dust as well as areas of major 'starburst' activity, where new stars are rapidly forming on timescales of 40 - 150 million years, much shorter than the age of the entire galaxy. At the center of the starburst rings is the Seyfert nucleus, the believed signature of a supermassive black hole that is accreting surrounding gas and dust. The black hole and its accretion disk are expelling gas out of the galaxy's disk and into its halo (the region above and below the disk). The detailed structure of this gas is seen as magenta-colored streamers extending towards the top of the image. In the center of the galaxy and within the inner starburst ring is a V-shaped structure of gas. The structure appears whitish-pink in this composite image, made up of four filters. Two

  12. Factorized Power Expansion for High-pT Heavy Quarkonium Production

    NASA Astrophysics Data System (ADS)

    Ma, Yan-Qing; Qiu, Jian-Wei; Sterman, George; Zhang, Hong

    2014-10-01

    We show that when the factorized cross section for heavy quarkonium production includes next-to-leading power contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high pT results calculated in nonrelativistic QCD (NRQCD) factorization. This extended formalism requires fragmentation functions for heavy quark pairs, as well as for light partons. When these fragmentation functions are themselves calculated using NRQCD, we find that two of the four leading NRQCD production channels, S31[1] and S10[8], are dominated by the next-to-leading power contributions for a very wide pT range. The large next-to-leading order corrections of NRQCD are absorbed into the leading order of the first power correction. The impact of this finding on heavy quarkonium production and its polarization is discussed.

  13. Factorized power expansion for high-pT heavy quarkonium production

    DOE PAGES

    Ma, Yan -Qing; Qiu, Jian -Wei; Sterman, George; Zhang, Hong

    2014-10-02

    In this study, we show that when the factorized cross section for heavy quarkonium production includes next-to-leading power contributions associated with the production of the heavy quark pair at short distances, it naturally reproduces all high pT results calculated in nonrelativistic QCD (NRQCD) factorization. This extended formalism requires fragmentation functions for heavy quark pairs, as well as for light partons. When these fragmentation functions are themselves calculated using NRQCD, we find that two of the four leading NRQCD production channels, ³S[1]1 and ¹S[8]0, are dominated by the next-to-leading power contributions for a very wide pT range. The large next-to-leading ordermore » corrections of NRQCD are absorbed into the leading order of the first power correction. The impact of this finding on heavy quarkonium production and its polarization is discussed.« less

  14. Hepatocyte tissue factor activates the coagulation cascade in mice

    PubMed Central

    Sullivan, Bradley P.; Kopec, Anna K.; Joshi, Nikita; Cline, Holly; Brown, Juliette A.; Bishop, Stephanie C.; Kassel, Karen M.; Rockwell, Cheryl; Mackman, Nigel

    2013-01-01

    In this study, we characterized tissue factor (TF) expression in mouse hepatocytes (HPCs) and evaluated its role in mouse models of HPC transplantation and acetaminophen (APAP) overdose. TF expression was significantly reduced in isolated HPCs and liver homogenates from TFflox/flox/albumin-Cre mice (HPCΔTF mice) compared with TFflox/flox mice (control mice). Isolated mouse HPCs expressed low levels of TF that clotted factor VII-deficient human plasma. In addition, HPC TF initiated factor Xa generation without exogenous factor VIIa, and TF activity was increased dramatically after cell lysis. Treatment of HPCs with an inhibitory TF antibody or a cell-impermeable lysine-conjugating reagent prior to lysis substantially reduced TF activity, suggesting that TF was mainly present on the cell surface. Thrombin generation was dramatically reduced in APAP-treated HPCΔTF mice compared with APAP-treated control mice. In addition, thrombin generation was dependent on donor HPC TF expression in a model of HPC transplantation. These results suggest that mouse HPCs constitutively express cell surface TF that mediates activation of coagulation during hepatocellular injury. PMID:23305736

  15. Factors Predicting Physical Activity Among Children With Special Needs

    PubMed Central

    Yee, Chu Tang; Chung, Paul J.

    2013-01-01

    Introduction Obesity is especially prevalent among children with special needs. Both lack of physical activity and unhealthful eating are major contributing factors. The objective of our study was to investigate barriers to physical activity among these children. Methods We surveyed parents of the 171 children attending Vista Del Mar School in Los Angeles, a nonprofit school serving a socioeconomically diverse group of children with special needs from kindergarten through 12th grade. Parents were asked about their child’s and their own physical activity habits, barriers to their child’s exercise, and demographics. The response rate was 67%. Multivariate logistic regression was used to examine predictors of children being physically active at least 3 hours per week. Results Parents reported that 45% of the children were diagnosed with attention deficit hyperactivity disorder, 38% with autism, and 34% with learning disabilities; 47% of children and 56% of parents were physically active less than 3 hours per week. The top barriers to physical activity were reported as child’s lack of interest (43%), lack of developmentally appropriate programs (33%), too many behavioral problems (32%), and parents’ lack of time (29%). However, child’s lack of interest was the only parent-reported barrier independently associated with children’s physical activity. Meanwhile, children whose parents were physically active at least 3 hours per week were 4.2 times as likely to be physically active as children whose parents were less physically active (P = .01). Conclusion In this group of students with special needs, children’s physical activity was strongly associated with parental physical activity; parent-reported barriers may have had less direct effect. Further studies should examine the importance of parental physical activity among children with special needs. PMID:23866163

  16. Factors affecting daily activities of patients with cerebral infarction

    PubMed Central

    Liu, Peng; Zhou, Cheng-ye; Zhang, Ying; Wang, Yun-feng; Zou, Chang-lin

    2010-01-01

    BACKGROUND: Stroke is the leading cause of death and long-term disability. This study was undertaken to investigate the factors influencing daily activities of patients with cerebral infarction so as to take interventional measures earlier to improve their daily activities. METHODS: A total of 149 patients with first-episode cerebral infarction were recruited into this prospective study. They were admitted to the Encephalopathy Center, Department of Neurology, the First Affiliated Hospital of Wenzhou Medical College in Zhejiang Province from August 2008 to December 2008. The baseline characteristics of the patients and cerebral infarction risk factors on the first day of admission were recorded. White blood cell (WBC) count, plasma glucose (PG), and many others of laboratory targets were collected in the next morning. Barthel index (BI) was calculated at 2 weeks and 3 months respectively after onset of the disease at the outpatient clinic or by telephone call. Lung infection, urinary tract infection and atrial fibrillation if any were recorded on admission. The National Institute of Health Stroke Scale (NIHSS) scores and the GCS scores were recorded within 24 hours on and after admission, at the second week, and at the third month after the onset of cerebral infarction respectively. RESULTS: The factors of BI at 2 weeks and 3 months after onset were the initial PG level, WBC count and initial NIHSS scores. Besides, urinary tract infection on admission was also the factor for BI at 3 months. CONCLUSION: Active measures should be taken to control these factors to improve the daily activities of patients with cerebral infarction. PMID:25214953

  17. The neurohormone orexin stimulates hypoxia-inducible factor-1 activity.

    PubMed

    Sikder, Devanjan; Kodadek, Thomas

    2007-11-15

    Orexin A and Orexin B (also known as hypocretins) are neuropeptides that bind two related G-coupled protein receptors (OXR1 and OXR2) and thus induce wakefulness, food consumption, and locomotion. Conversely, deletion of the orexin gene in mice produces a condition similar to canine and human narcolepsy. Despite the central importance of the orexin system in regulating wakefulness and feeding behavior, little is known about the downstream signaling mechanisms that achieve these effects. In this study, genomics techniques are used to probe this question and reveal that orexin activates the hypoxia-inducible factor 1 (HIF-1), a heterodimeric transcription factor whose pathogenic role in stimulating angiogenesis in hypoxic tumors has been the focus of intense investigation. Orexin-stimulated HIF-1 activity is due to both increased HIF-1alpha gene transcription and a down-regulation of von Hippel-Lindau (VHL), the E3 ubiquitin ligase that mediates the turnover of HIF-1 via the ubiquitin-proteasome pathway. Orexin-mediated activation of HIF-1 results in increased glucose uptake and higher glycolytic activity, as expected from studies of hypoxic cells. However, orexin receptor-expressing cells somehow override the HIF-1-mediated preference for funneling pyruvate into anaerobic glycolysis and instead favor ATP production through the tricarboxylic acid cycle and oxidative phosphorylation. These findings implicate HIF-1 as an important transcription factor in the hormone-mediated regulation of hunger and wakefulness.

  18. Thyroid-specific transcription factors control Hex promoter activity

    PubMed Central

    Puppin, Cinzia; D'Elia, Angela V.; Pellizzari, Lucia; Russo, Diego; Arturi, Franco; Presta, Ivan; Filetti, Sebastiano; Bogue, Clifford W.; Denson, Lee A.; Damante, Giuseppe

    2003-01-01

    The homeobox-containing gene Hex is expressed in several cell types, including thyroid follicular cells, in which it regulates the transcription of tissue- specific genes. In this study the regulation of Hex promoter activity was investigated. Using co- transfection experiments, we demonstrated that the transcriptional activity of the Hex gene promoter in rat thyroid FRTL-5 cells is ∼10-fold greater than that observed in HeLa and NIH 3T3 cell lines (which do not normally express the Hex gene). To identify the molecular mechanisms underlying these differences, we evaluated the effect of the thyroid- specific transcription factor TTF-1 on the Hex promoter activity. TTF-1 produced 3–4-fold increases in the Hex promoter activity. Gel- retardation assays and mutagenesis experiments revealed the presence of functionally relevant TTF-1 binding sites in the Hex promoter region. These in vitro data may also have functional relevance in vivo, since a positive correlation between TTF-1 and Hex mRNAs was demonstrated in human thyroid tissues by means of RT–PCR analysis. The TTF-1 effect, however, is not sufficient to explain the difference in Hex promoter activity between FRTL-5 and cells that do not express the Hex gene. For this reason, we tested whether Hex protein is able to activate the Hex promoter. Indeed, co-transfection experiments indicate that Hex protein is able to increase the activity of its own promoter in HeLa cells ∼4-fold. TTF-1 and Hex effects are additive: when transfected together in HeLa cells, the Hex promoter activity is increased 6–7-fold. Thus, the contemporary presence of both TTF-1 and Hex could be sufficient to explain the higher transcriptional activity of the Hex promoter in thyroid cells with respect to cell lines that do not express the Hex gene. These findings demonstrate the existence of direct cross-regulation between thyroid-specific transcription factors. PMID:12655000

  19. Spin-orbital coupling effect on the power factor in semiconducting transition-metal dichalcogenide monolayers

    NASA Astrophysics Data System (ADS)

    Guo, San-Dong; Wang, Jian-Li

    2016-09-01

    The electronic structures and thermoelectric properties of semiconducting transition-metal dichalcogenide monolayers {{MX}}2 (M = Zr, Hf, Mo, W and Pt; X = S, Se and Te) are investigated by combining first-principles and Boltzmann transport theory, including spin-orbital coupling (SOC). It is found that the gap decrease increases from S to Te in each cation group when the SOC is opened. The spin-orbital splitting has the same trend with the gap reducing. The calculated results show that SOC has a noteworthy detrimental effect on the p-type power factor, while it has a negligible influence in n-type doping except for the W cation group, which can be understood by considering the effects of SOC on the valence and conduction bands. For {{WX}}2 (X = S, Se and Te), SOC leads to an observable enhanced power factor in n-type doping, which can be explained by SOC-induced band degeneracy, namely the bands converge. Among all of the cation groups, the Pt cation group shows the highest Seebeck coefficient, which leads to the best power factor, if we assume that the scattering time is fixed. The calculated results show that {{MS}}2 (M = Zr, Hf, Mo, W and Pt) have the best p-type power factor of all the cation groups, and that {{MSe}}2 (M = Zr and Hf), {{WS}}2 and {{MTe}}2 (M = Mo and Pt) have a more excellent n-type power factor in their respective cation group. Therefore, these results may be useful for further theoretical prediction or experimental research of excellent thermoelectric materials from semiconducting transition-metal dichalcogenide monolayers.

  20. Spin–orbital coupling effect on the power factor in semiconducting transition-metal dichalcogenide monolayers

    NASA Astrophysics Data System (ADS)

    Guo, San-Dong; Wang, Jian-Li

    2016-09-01

    The electronic structures and thermoelectric properties of semiconducting transition-metal dichalcogenide monolayers {{MX}}2 (M = Zr, Hf, Mo, W and Pt; X = S, Se and Te) are investigated by combining first-principles and Boltzmann transport theory, including spin–orbital coupling (SOC). It is found that the gap decrease increases from S to Te in each cation group when the SOC is opened. The spin–orbital splitting has the same trend with the gap reducing. The calculated results show that SOC has a noteworthy detrimental effect on the p-type power factor, while it has a negligible influence in n-type doping except for the W cation group, which can be understood by considering the effects of SOC on the valence and conduction bands. For {{WX}}2 (X = S, Se and Te), SOC leads to an observable enhanced power factor in n-type doping, which can be explained by SOC-induced band degeneracy, namely the bands converge. Among all of the cation groups, the Pt cation group shows the highest Seebeck coefficient, which leads to the best power factor, if we assume that the scattering time is fixed. The calculated results show that {{MS}}2 (M = Zr, Hf, Mo, W and Pt) have the best p-type power factor of all the cation groups, and that {{MSe}}2 (M = Zr and Hf), {{WS}}2 and {{MTe}}2 (M = Mo and Pt) have a more excellent n-type power factor in their respective cation group. Therefore, these results may be useful for further theoretical prediction or experimental research of excellent thermoelectric materials from semiconducting transition-metal dichalcogenide monolayers.

  1. Losac, the First Hemolin that Exhibits Procogulant Activity through Selective Factor X Proteolytic Activation*

    PubMed Central

    Alvarez-Flores, Miryam Paola; Furlin, Daniel; Ramos, Oscar H. P.; Balan, Andrea; Konno, Katsuhiro; Chudzinski-Tavassi, Ana Marisa

    2011-01-01

    Envenoming by the contact of human skin with Lonomia obliqua caterpillars promotes a hemorrhagic syndrome characterized by a consumptive coagulopathy. Losac (Lonomia obliqua Stuart factor activator) is a component of the bristle of L. obliqua that is probably partially responsible for the observed syndrome because it activates factor X and is recognized by an effective antilonomic serum. Here we unveil the proteolytic activity of Losac and demonstrate the feasibility of its recombinant production. On the other hand, Losac has no homology to known proteases, but it can be inhibited by PMSF, a serine protease inhibitor. Instead, it shows closer homology to members of the hemolin family of proteins, a group of cell adhesion molecules. The recombinant protein (rLosac) shortened the coagulation time of normal and deficient plasmas, whereas it was ineffective in factor X-deficient plasma unless reconstituted with this protein. rLosac was able to activate factor X in a dose- and time-dependent manner but not γ-carboxyglutamic acid domainless factor X. Moreover, phospholipids and calcium ions increased rLosac activity. Also, rLosac had no effect on fibrin or fibrinogen, indicating its specificity for blood coagulation activation. Linear double reciprocal plots indicate that rLosac follows a Michaelis-Menten kinetics. Cleavage of factor X by rLosac resulted in fragments that are compatible with those generated by RVV-X (a well known factor X activator). Together, our results validate Losac as the first protein from the hemolin family exhibiting procoagulant activity through selective proteolysis on coagulation factor X. PMID:21177860

  2. High-power optical millimeter-wave signal generation with tunable frequency multiplication factor

    NASA Astrophysics Data System (ADS)

    Han, Yi-shi; Zheng, Zhenyu; Luo, Zhixiao; Min, Zhixuan; Xu, Ou; Liu, Jie

    2015-01-01

    This work demonstrates a simple and novel scheme for millimeter-wave (MMW) signal generation using optical multi-sidebands (OMSB) modulation. In the proposed methods, several pairs of optical sidebands can be generated by employing parallel phase modulators driven by a low frequency radio frequency (RF) signal. The optical sidebands will beat at a photodetector (PD) to generate high frequency MMW signal with tunable frequency multiplication factor, such as frequency octupling, 12-tupling, 16-tupling and 18-tupling. Since no optical filters or DC bias are used, the MMW signal has the evident character of high-power output. A generalized analytic expression and simulation verification for generating the frequency multi-tupling MMW signal are developed. The influences caused by non-ideal factors are discussed in detail, and undesired power ratios versus non-ideal factors are plotted and analyzed.

  3. Expression of active human factor IX in transfected cells.

    PubMed

    Busby, S; Kumar, A; Joseph, M; Halfpap, L; Insley, M; Berkner, K; Kurachi, K; Woodbury, R

    Factor IX is the precursor of a serine protease that functions in the intrinsic blood clotting pathway. Deficiencies in this plasma glycoprotein result in haemophilia B (or Christmas disease) and occur in about 1 in 30,000 males. Patients are currently treated with fresh frozen plasma or prothrombin complex concentrates prepared from pooled plasma from normal individuals. There are several problems with this method of treatment, including the probable exposure of the patients to contaminants such as the viral agents responsible for hepatitis and AIDS (acquired immune deficiency syndrome). As a first step towards an alternative source of pure human factor IX, we report here on the use of recombinant DNA techniques to produce biologically active factor IX in cultured mammalian cells. Stable cell lines were produced by cotransfecting a baby hamster kidney (BHK) cell line with a plasmid containing a gene for factor IX and a plasmid containing a selectable marker. Protein secreted by these cell lines reduces the clotting time of plasma from factor IX-deficient patients. We present additional evidence that this protein is authentic human factor IX.

  4. Biosynthesis of nitric oxide activates iron regulatory factor in macrophages.

    PubMed

    Drapier, J C; Hirling, H; Wietzerbin, J; Kaldy, P; Kühn, L C

    1993-09-01

    Biosynthesis of nitric oxide (NO) from L-arginine modulates activity of iron-dependent enzymes, including mitochondrial acontiase, an [Fe-S] protein. We examined the effect of NO on the activity of iron regulatory factor (IRF), a cytoplasmic protein which modulates both ferritin mRNA translation and transferrin receptor mRNA stability by binding to specific mRNA sequences called iron responsive elements (IREs). Murine macrophages were activated with interferon-gamma and lipopolysaccharide to induce NO synthase activity and cultured in the presence or absence of NG-substituted analogues of L-arginine which served as selective inhibitors of NO synthesis. Measurement of the nitrite concentration in the culture medium was taken as an index of NO production. Mitochondria-free cytosols were then prepared and aconitase activity as well as IRE binding activity and induction of IRE binding activity were correlated and depended on NO synthesis after IFN-gamma and/or LPS stimulation. Authentic NO gas as well as the NO-generating compound 3-morpholinosydnonimine (SIN-1) also conversely modulated aconitase and IRE binding activities of purified recombinant IRF. These results provide evidence that endogenously produced NO may modulate the post-transcriptional regulation of genes involved in iron homeostasis and support the hypothesis that the [Fe-S] cluster of IRF mediates iron-dependent regulation. PMID:7504626

  5. Factors related to physical activity: a study of adolescents.

    PubMed

    Vilhjalmsson, R; Thorlindsson, T

    1998-09-01

    Although the consequences of physical activity have been carefully documented, less is known about its correlates, particularly among children and youth. Based on a representative national survey of 1131 Icelandic adolescents, the study examined various physical, psychological, social and demographic factors related to physical activity. Male sex, significant others' involvement in physical activity (father, friend and older brother), sociability, perceived importance of sport and of health improvement and satisfaction with mandatory gym classes in school, were all related to more involvement, whereas hours of paid work and TV-viewing were related to less. Furthermore, the data suggested that the influence of friend's participation in physical activity depends on his or her emotional significance. Influential others appeared to affect males and females in the same way. The meaning of the results and their implications for future research are discussed.

  6. Regulation of APC Activity by Phosphorylation and Regulatory Factors

    PubMed Central

    Kotani, Shuji; Tanaka, Hirofumi; Yasuda, Hideyo; Todokoro, Kazuo

    1999-01-01

    Ubiquitin-dependent proteolysis of Cut2/Pds1 and Cyclin B is required for sister chromatid separation and exit from mitosis, respectively. Anaphase-promoting complex/cyclosome (APC) specifically ubiquitinates Cut2/Pds1 at metaphase–anaphase transition, and ubiquitinates Cyclin B in late mitosis and G1 phase. However, the exact regulatory mechanism of substrate-specific activation of mammalian APC with the right timing remains to be elucidated. We found that not only the binding of the activators Cdc20 and Cdh1 and the inhibitor Mad2 to APC, but also the phosphorylation of Cdc20 and Cdh1 by Cdc2-Cyclin B and that of APC by Polo-like kinase and cAMP-dependent protein kinase, regulate APC activity. The cooperation of the phosphorylation/dephosphorylation and the regulatory factors in regulation of APC activity may thus control the precise progression of mitosis. PMID:10459014

  7. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

    SciTech Connect

    Hirshfield, Jay L.

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  8. The dust covering factor in active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Stalevski, Marko; Ricci, Claudio; Ueda, Yoshihiro; Lira, Paulina; Fritz, Jacopo; Baes, Maarten

    2016-05-01

    The primary source of emission of active galactic nuclei (AGNs), the accretion disc, is surrounded by an optically and geometrically thick dusty structure (`the so-called dusty torus'). The infrared radiation emitted by the dust is nothing but a reprocessed fraction of the accretion disc emission, so the ratio of the torus to the AGN luminosity (Ltorus/LAGN) should corresponds to the fraction of the sky obscured by dust, i.e. the covering factor. We undertook a critical investigation of the Ltorus/LAGN as the dust covering factor proxy. Using state-of-the-art 3D Monte Carlo radiative transfer code, we calculated a grid of spectral energy distributions (SEDs) emitted by the clumpy two-phase dusty structure. With this grid of SEDs, we studied the relation between Ltorus/LAGN and the dust covering factor for different parameters of the torus. We found that in the case of type 1 AGNs the torus anisotropy makes Ltorus/LAGN underestimate low covering factors and overestimate high covering factors. In type 2 AGNs Ltorus/LAGN always underestimates covering factors. Our results provide a novel easy-to-use method to account for anisotropy and obtain correct covering factors. Using two samples from the literature, we demonstrated the importance of our result for inferring the obscured AGN fraction. We found that after the anisotropy is properly accounted for, the dust covering factors show very weak dependence on LAGN, with values in the range of ≈0.6-0.7. Our results also suggest a higher fraction of obscured AGNs at high luminosities than those found by X-ray surveys, in part owing to the presence of a Compton-thick AGN population predicted by population synthesis models.

  9. Prioritization of factors impacting on performance of power looms using AHP

    NASA Astrophysics Data System (ADS)

    Dulange, S. R.; Pundir, A. K.; Ganapathy, L.

    2014-08-01

    The purpose of this paper is to identify the critical success factors influencing the performance of power loom textiles, to evaluate their impact on the organizational performance and to find out the effect of these factors on the organizational performance of small and medium-sized enterprises (SMEs) in the Solapur (Maharashtra) industrial sector using AHP. In the methodology adopted, factors are identified through the literature survey and finalization of these factors is done by taking the opinion of experts in the Indian context. By cognitive map, the relation between these factors (direct and indirect effect) is determined and cause and effect diagram is prepared. Then these factors are arranged hierarchically and tree diagram is prepared. A questionnaire was designed and distributed among the experts; data is collected. Using expert choice software data is filled to quantify by pair-wise comparison of these factors and are prioritized. The weights demonstrate several key findings: local and global priority reveals that there is a substantial effect of the human resource, product style, and volume on the organizational performance. The skills and technology upgradation impact on organizational performance. Maintenance plays an important role in improving the organizational performances of the SMEs. Overall, the results showed the central role of the operational factors are important. The research is subject to the normal limitations of AHP. The study is using perceptual data provided by Experts which may not provide clear measures of impact factors. However, this can be overcome using more experts to collect data in future studies. Interestingly, the findings here may be generalisable outside Solapur like Ichalkarnji, Malegaon, and Bhiwadi (Maharashtra). Solapur power loom SMEs should consider AHP as an innovative tool for quantification of factors impacting on performance and improving operational and organizational performance in today's dynamic

  10. Selective Activation of Transcription by a Novel CCAAT Binding Factor

    NASA Astrophysics Data System (ADS)

    Maity, Sankar N.; Golumbek, Paul T.; Karsenty, Gerard; de Crombrugghe, Benoit

    1988-07-01

    A novel CCAAT binding factor (CBF) composed of two different subunits has been extensively purified from rat liver. Both subunits are needed for specific binding to DNA. Addition of this purified protein to nuclear extracts of NIH 3T3 fibroblasts stimulates transcription from several promoters including the α 2(I) collagen, the α 1(I) collagen, the Rous sarcoma virus long terminal repeat (RSV-LTR), and the adenovirus major late promoter. Point mutations in the CCAAT motif that show either no binding or a decreased binding of CBF likewise abolish or reduce activation of transcription by CBF. Activation of transcription requires, therefore, the specific binding of CBF to its recognition sites.

  11. TALE factors poise promoters for activation by Hox proteins.

    PubMed

    Choe, Seong-Kyu; Ladam, Franck; Sagerström, Charles G

    2014-01-27

    Hox proteins form complexes with TALE cofactors from the Pbx and Prep/Meis families to control transcription, but it remains unclear how Hox:TALE complexes function. Examining a Hoxb1b:TALE complex that regulates zebrafish hoxb1a transcription, we find maternally deposited TALE proteins at the hoxb1a promoter already during blastula stages. These TALE factors recruit histone-modifying enzymes to promote an active chromatin profile at the hoxb1a promoter and also recruit RNA polymerase II (RNAPII) and P-TEFb. However, in the presence of TALE factors, RNAPII remains phosphorylated on serine 5 and hoxb1a transcription is inefficient. By gastrula stages, Hoxb1b binds together with TALE factors to the hoxb1a promoter. This triggers P-TEFb-mediated transitioning of RNAPII to the serine 2-phosphorylated form and efficient hoxb1a transcription. We conclude that TALE factors access promoters during early embryogenesis to poise them for activation but that Hox proteins are required to trigger efficient transcription.

  12. Quantifying baseline emission factors of air pollutants in China's regional power grids.

    PubMed

    Cai, Wenjia; Wang, Can; Jin, Zhugang; Chen, Jining

    2013-04-16

    Drawing lessons from the clean development mechanism (CDM), this paper developed a combined margin methodology to quantify baseline emission factors of air pollutants in China's regional power grids. The simple average of baseline emission factors of SO2, NOX, and PM2.5 in China's six power grids in 2010 were respectively 1.91 kg/MWh, 1.83 kg/MWh and 0.32 kg/MWh. Several low-efficient mitigation technologies, such as low nitrogen oxide burner (LNB), were suggested to be replaced or used together with other technologies in order to virtually decrease the grid's emission factor. The synergies between GHG and air pollution mitigation in China's power sector was also notable. It is estimated that in 2010, that every 1% CO2 reduction in China's power generation sector resulted in the respective coreduction of 1.1%, 0.5%, and 0.8% of SO2, NOX, and PM2.5. Wind is the best technology to achieve the largest amount of coabatement in most parts of China. This methodology is recommended to be used in making comprehensive air pollution control strategies and in cobenefits analysis in future CDM approval processes.

  13. Activating Transcription Factor 3 and the Nervous System

    PubMed Central

    Hunt, David; Raivich, Gennadij; Anderson, Patrick Norval

    2012-01-01

    Activating transcription factor 3 (ATF3) belongs to the ATF/cyclic AMP responsive element binding family of transcription factors and is often described as an adaptive response gene whose activity is usually regulated by stressful stimuli. Although expressed in a number of splice variants and generally recognized as a transcriptional repressor, ATF3 has the ability to interact with a number of other transcription factors including c-Jun to form complexes which not only repress, but can also activate various genes. ATF3 expression is modulated mainly at the transcriptional level and has markedly different effects in different types of cell. The levels of ATF3 mRNA and protein are normally very low in neurons and glia but their expression is rapidly upregulated in response to injury. ATF3 expression in neurons is closely linked to their survival and the regeneration of their axons following axotomy, and that in peripheral nerves correlates with the generation of a Schwann cell phenotype that is conducive to axonal regeneration. ATF3 is also induced by Toll-like receptor (TLR) ligands but acts as a negative regulator of TLR signaling, suppressing the innate immune response which is involved in immuno-surveillance and can enhance or reduce the survival of injured neurons and promote the regeneration of their axons. PMID:22347845

  14. Stellar Activity and CMEs: Important Factors of Planetary Evolution

    NASA Astrophysics Data System (ADS)

    Khodachenko, Maxim L.

    CME activity of the Sun is known to be an important impacting factor for the magnetospheres, atmospheres, and surfaces of solar system planets. Following an idea of a solar-stellar analogy, CME phenomena are expected on other stars as well. The main planetary impact factors of the stellar CMEs include the associated interplanetary shocks, plasma density and velocity disturbances, energetic particles accelerated in the shock regions, as well as distortions of the magnetic field direction and modulus. All these factors should be properly taken into account during the study of evolutionary processes on exoplanets and their atmospheric and plasma environments. The planetary impact of the stellar CME activity may vary depending on stellar age, stellar spectral type and the orbital distance of a planet. Because of the relatively short range of propagation of the majority of CMEs, they affect most strongly the magnetospheres and atmospheres of close-orbit ( < 0.1 AU) exoplanets. In this chapter we discuss an issue of the stellar CME activity in the context of several actual problems of modern exoplanetology, including planetary atmosphere mass loss, planet survival at close orbits, and definition of a criterion for habitability.

  15. Compilation of Trade Studies for the Constellation Program Extravehicular Activity Spacesuit Power System

    NASA Technical Reports Server (NTRS)

    Fincannon, James

    2009-01-01

    This compilation of trade studies performed from 2005 to 2006 addressed a number of power system design issues for the Constellation Program Extravehicular Activity Spacesuit. Spacesuits were required for spacewalks and in-space activities as well as lunar and Mars surface operations. The trades documented here considered whether solar power was feasible for spacesuits, whether spacesuit power generation should be a distributed or a centralized function, whether self-powered in-space spacesuits were better than umbilically powered ones, and whether the suit power system should be recharged in place or replaced.

  16. An efficient algorithm to identify coordinately activated transcription factors.

    PubMed

    Hu, Haiyan

    2010-03-01

    Identification of transcription factor (TF) activities associated with a certain physiological/experimental condition is one of the preliminary steps to reconstruct transcriptional regulatory networks and to identify signal transduction pathways. TF activities are often indicated by the activities of its target genes. Existing studies on identifying TF activities through target genes usually assume the equivalence between co-regulation and co-expression. However, genes with correlated expression profiles may not be co-regulated. In the mean time, although multiple TFs can be activated coordinately, there is a lack of efficient methods to identify coordinately activated TFs. In this paper, we propose an efficient algorithm embedding a dynamic programming procedure to identify a subset of TFs that are potentially coordinately activated under a given condition by utilizing ranked lists of differentially expressed target genes. Applying our algorithm to microarray expression data sets for a number of diseases, our approach found subsets of TFs that are highly likely associated with the given disease processes. PMID:20060041

  17. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease.

    PubMed

    Naranjo, José R; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C; Arrabal, María D; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-02-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD.

  18. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease.

    PubMed

    Naranjo, José R; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C; Arrabal, María D; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-02-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD. PMID:26752648

  19. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease

    PubMed Central

    Naranjo, José R.; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M.; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C.; Arrabal, María D.; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-01-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD. PMID:26752648

  20. Overexpression and activation of epidermal growth factor receptor in hemangioblastomas

    PubMed Central

    Chen, Gregory J.; Karajannis, Matthias A.; Newcomb, Elizabeth W.

    2010-01-01

    Hemangioblastomas frequently develop in patients with von Hippel-Lindau (VHL) disease, an autosomal dominant genetic disorder. The tumors are characterized by a dense network of blood capillaries, often in association with cysts. Although activation of receptor tyrosine kinase (RTK) signaling, including epidermal growth factor receptor (EGFR) has been implicated in the development of malignant brain tumors such as high-grade gliomas, little is known about the role of RTK signaling in hemangioblastomas. To address this issue, we examined hemangioblastoma tumor specimens using receptor tyrosine kinase (RTK) activation profiling and immunohistochemistry. Six human hemangioblastomas were analyzed with a phospho-RTK antibody array, revealing EGFR phosphorylation in all tumors. EGFR expression was confirmed by immunohistochemistry in all tumors analyzed and downstream effector pathway activation was demonstrated by positive staining for phospho-AKT. Our findings suggest that, in primary hemangioblastomas, RTK upregulation and signaling predominantly involves EGFR, providing an attractive molecular target for therapeutic intervention. PMID:20730556

  1. Modulation of topoisomerase activities by tumor necrosis factor.

    PubMed

    Baloch, Z; Cohen, S; Fresa, K; Coffman, F D

    1995-01-01

    A number of chemotherapeutic agents which inhibit the DNA topoisomerases markedly potentiate cell death mediated by tumor necrosis factor, suggesting a role for these enzymes in the TNF cytotoxic mechanism. To investigate this possibility, topoisomerase I and II activities were assayed following TNF addition to murine L929 cells. Topoisomerase I and II activities increased within 15 min of TNF addition and returned to baseline levels within 1 and 2 hr, respectively. The increases in both topoisomerase activities were blocked by H-7 (but not H-8) and similar increases were seen following PMA addition. However, concentrations of H-7 which blocked the increased topoisomerase activities had no effect on TNF cytotoxicity nor on the enhancement of TNF cytotoxicity by topoisomerase inhibitors. Thus, in these cells topoisomerase activities are directly modified by TNF during the initial phases of a cytotoxic response. However, neither TNF cytotoxicity nor the enhancement of TNF cytotoxicity by topoisomerase inhibitors appears to require the TNF-mediated increases in topoisomerase activities. PMID:7842491

  2. Measurement of mechanical quality factors of polymers in flexural vibration for high-power ultrasonic application.

    PubMed

    Wu, Jiang; Mizuno, Yosuke; Tabaru, Marie; Nakamura, Kentaro

    2016-07-01

    A method for measuring the mechanical quality factor (Q factor) of materials in large-amplitude flexural vibrations was devised on the basis of the original definition of the Q factor. The Q factor, the ratio of the reactive energy to the dissipated energy, was calculated from the vibration velocity distribution. The bar thickness was selected considering the effect of the thickness on the estimation error. In the experimental setup, a 1-mm-thick polymer-based bar was used as a sample and fixed on the top of a longitudinal transducer. Using transducers of different lengths, flexural waves in the frequency range of 20-90kHz were generated on the bar. The vibration strain in the experiment reached 0.06%. According to the Bernoulli-Euler model, the reactive energy and dissipated energy were estimated from the vertical velocity distribution on the bar, and the Q factors were measured as the driving frequency and strain were varied. The experimental results showed that the Q factors decrease as the driving frequencies and strains increase. At a frequency of 28.30kHz, the Q factor of poly(phenylene sulfide) (PPS) reached approximately 460 when the strain was smaller than 0.005%. PPS exhibited a much higher Q factor than the other tested polymers, which implies that it is a potentially applicable material as the elastomer for high-power ultrasonic devices. PMID:27065470

  3. Time-activity relationships to VOC personal exposure factors

    NASA Astrophysics Data System (ADS)

    Edwards, Rufus D.; Schweizer, Christian; Llacqua, Vito; Lai, Hak Kan; Jantunen, Matti; Bayer-Oglesby, Lucy; Künzli, Nino

    Social and demographic factors have been found to play a significant role in differences between time-activity patterns of population subgroups. Since time-activity patterns largely influence personal exposure to compounds as individuals move across microenvironments, exposure subgroups within the population may be defined by factors that influence daily activity patterns. Socio-demographic and environmental factors that define time-activity subgroups also define quantifiable differences in VOC personal exposures to different sources and individual compounds in the Expolis study. Significant differences in exposures to traffic-related compounds ethylbenzene, m- and p-xylene and o-xylene were observed in relation to gender, number of children and living alone. Categorization of exposures further indicated time exposed to traffic at work and time in a car as important determinants. Increased exposures to decane, nonane and undecane were observed for males, housewives and self-employed. Categorization of exposures indicated exposure subgroups related to workshop use and living downtown. Higher exposures to 3-carene and α-pinene commonly found in household cleaning products and fragrances were associated with more children, while exposures to traffic compounds ethylbenzene, m- and p-xylene and o-xylene were reduced with more children. Considerable unexplained variation remained in categorization of exposures associated with home product use and fragrances, due to individual behavior and product choice. More targeted data collection methods in VOC exposure studies for these sources should be used. Living alone was associated with decreased exposures to 2-methyl-1-propanol and 1-butanol, and traffic-related compounds. Identification of these subgroups may help to reduce the large amount of unexplained variation in VOC exposure studies. Further they may help in assessing impacts of urban planning that result in changes in behavior of individuals, resulting in shifts in

  4. Comparison of AB2588 multipathway risk factors for California fossil-fuel power stations

    SciTech Connect

    Gratt, L.B.; Levin, L.

    1997-12-31

    Substances released from power plants may travel through various exposure pathways resulting in human health and environmental risks. The stack air emission`s primary pathway is inhalation from the ambient air. Multipathway factors (adjustment factors to the inhalation risk) are used to evaluate the importance of non-inhalation pathways (such as ingestion and dermal contact). The multipathway factor for a specific substance is the health risk by all pathways divided by the inhalation health risk for that substance. These factors are compared for fossil fuel power stations that submitted regulatory risk assessments in compliance with California Toxic Hot Spots Act (AB2588). Substances representing the largest contributions to the cancer risk are of primary concern: arsenic, beryllium, cadmium, chromium (+6), formaldehyde, nickel, lead, selenium, and PAHs. Comparisons of the chemical-specific multipathway factors show the impacts of regulatory policy decisions on the estimated health risk for trace substances. As an example, point estimates of the soil mixing depth, varying from 1 cm to 15 cm, relate to the relative importance of the pathway. For the deeper mixing depths, the root-zone uptake by homegrown tomato plants (for assumed consumption rate of 15% for San Diego) may result in high multipathway factors for several trace metals. For shallower mixing depths, soil ingestion may become the dominant non-inhalation pathway. These differences may lead to significantly different risk estimates for similar facilities located at different California locations such as to be under local regulatory authorities. The overall multipathway factor for the total cancer risk is about 2, much smaller than some of the chemical-specific factors. Science-based multipathway analysis should reduce much of the concern that may be due to policy-based decisions on pathway selection and high-value point-estimates of the parameters.

  5. Ultrahigh power factor and thermoelectric performance in hole-doped single-crystal SnSe.

    PubMed

    Zhao, Li-Dong; Tan, Gangjian; Hao, Shiqiang; He, Jiaqing; Pei, Yanling; Chi, Hang; Wang, Heng; Gong, Shengkai; Xu, Huibin; Dravid, Vinayak P; Uher, Ctirad; Snyder, G Jeffrey; Wolverton, Chris; Kanatzidis, Mercouri G

    2016-01-01

    Thermoelectric technology, harvesting electric power directly from heat, is a promising environmentally friendly means of energy savings and power generation. The thermoelectric efficiency is determined by the device dimensionless figure of merit ZT(dev), and optimizing this efficiency requires maximizing ZT values over a broad temperature range. Here, we report a record high ZT(dev) ∼1.34, with ZT ranging from 0.7 to 2.0 at 300 to 773 kelvin, realized in hole-doped tin selenide (SnSe) crystals. The exceptional performance arises from the ultrahigh power factor, which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient enabled by the contribution of multiple electronic valence bands present in SnSe. SnSe is a robust thermoelectric candidate for energy conversion applications in the low and moderate temperature range.

  6. Unity power factor converter based on a fuzzy controller and predictive input current.

    PubMed

    Bouafassa, Amar; Rahmani, Lazhar; Kessal, Abdelhalim; Babes, Badreddine

    2014-11-01

    This paper proposes analysis and control of a single-phase power factor corrector (PFC). The proposed control is capable of achieving a unity power factor for each DC link voltage or load fluctuation. The method under study is composed of two intelligent approaches, a fuzzy logic controller to ensure an output voltage at a suitable value and predictive current control. The fuzzy controller is used with minimum rules to attain a low cost. The method is verified and discussed through simulation on the MATLAB/Simulink platform. It presents high dynamic performance under various parameter changes. Moreover, in order to examine and evaluate the method in real-time, a test bench is built using dSPACE 1104. The implantation of the proposed method is very easy and flexible and allows for operation under parameter variations. Additionally, the obtained results are very significant.

  7. One-dimensional behavior and high thermoelectric power factor in thin indium arsenide nanowires

    SciTech Connect

    Mensch, P.; Karg, S. Schmidt, V.; Gotsmann, B.; Schmid, H.; Riel, H.

    2015-03-02

    Electrical conductivity and Seebeck coefficient of quasi-one-dimensional indium arsenide (InAs) nanowires with 20 nm diameter are investigated. The carrier concentration of the passivated nanowires was modulated by a gate electrode. A thermoelectric power factor of 1.7 × 10{sup −3} W/m K{sup 2} was measured at room temperature. This value is at least as high as in bulk-InAs and exceeds by far typical values of thicker InAs nanowires with three-dimensional properties. The interpretation of the experimental results in terms of power-factor enhancement by one-dimensionality is supported by model calculations using the Boltzmann transport formalism.

  8. Active high-power RF switch and pulse compression system

    DOEpatents

    Tantawi, Sami G.; Ruth, Ronald D.; Zolotorev, Max

    1998-01-01

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  9. Transcription-dependent epidermal growth factor receptor activation by hepatocyte growth factor.

    PubMed

    Reznik, Thomas E; Sang, Yingying; Ma, Yongxian; Abounader, Roger; Rosen, Eliot M; Xia, Shuli; Laterra, John

    2008-01-01

    The mechanisms and biological implications of coordinated receptor tyrosine kinase coactivation remain poorly appreciated. Epidermal growth factor receptor (EGFR) and c-Met are frequently coexpressed in cancers, including those associated with hepatocyte growth factor (HGF) overexpression, such as malignant astrocytoma. In a previous analysis of the HGF-induced transcriptome, we found that two EGFR agonists, transforming growth factor-alpha and heparin-binding epidermal growth factor-like growth factor (HB-EGF), are prominently up-regulated by HGF in human glioma cells. We now report that stimulating human glioblastoma cells with recombinant HGF induces biologically relevant EGFR activation. EGFR phosphorylation at Tyr(845) and Tyr(1068) increased 6 to 24 h after cell stimulation with HGF and temporally coincided with the induction of transforming growth factor-alpha (~5-fold) and HB-EGF (~23-fold) expression. Tyr(845) and Tyr(1068) phosphorylation, in response to HGF, was inhibited by cycloheximide and actinomycin D, consistent with a requirement for DNA transcription and RNA translation. Specifically, blocking HB-EGF binding to EGFR with the antagonist CRM197 inhibited HGF-induced EGFR phosphorylation by 60% to 80% and inhibited HGF-induced S-G(2)-M transition. CRM197 also inhibited HGF-induced anchorage-dependent cell proliferation but had no effect on HGF-mediated cytoprotection. These findings establish that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression. This transcription-dependent cross-talk between the HGF receptor c-Met and EGFR expands our understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics.

  10. Absence of in vitro Procoagulant Activity in Immunoglobulin Preparations due to Activated Coagulation Factors

    PubMed Central

    Oviedo, Adriana E.; Bernardi, María E.; Guglielmone, Hugo A.; Vitali, María S.

    2015-01-01

    Summary Background Immunoglobulin (IG) products, including intravenous (IVIG) or subcutaneous (SCIG) immunoglobulins are considered safe and effective for medical therapy; however, a sudden and unexpected increase in thromboembolic events (TE) after administration of certain batches of IVIG products has been attributed to the presence of activated coagulation factors, mainly factor XIa. Our aims were to examine the presence of enduring procoagulant activity during the manufacturing process of IGs, with special focus on monitoring factor XIa, and to evaluate the presence of in vitro procoagulant activity attributed to coagulation factors in different lots of IVIG and SCIG. Methods Samples of different steps of IG purification, 19 lots of IVIG and 9 of SCIG were analyzed and compared with 1 commercial preparation of IVIG and 2 of SCIG, respectively. Factors II, VII, IX, XI and XIa and non-activated partial thromboplastin time (NAPTT) were assayed. Results The levels of factors II, VII, IX, X and XI were non-quantifiable once fraction II had been re-dissolved and in all analyzed lots of IVIG and SCIG. The level of factor XIa at that point was under the detection limits of the assay, and NAPTT yielded values greater than the control during the purification process. In SCIG, we detected higher concentrations of factor XIa in the commercial products, which reached values up to 5 times higher than the average amounts found in the 9 batches produced by UNC-Hemoderivados. Factor XIa in commercial IVIG reached levels slightly higher than those of the 19 batches produced by UNC-Hemoderivados. Conclusion IVIG and SCIG manufactured by UNC-Hemoderivados showed a lack of thrombogenic potential, as demonstrated not only by the laboratory data obtained in this study but also by the absence of any reports of TE registered by the post marketing pharmacovigilance department. PMID:26733772

  11. Testing Active Power Control from Wind Power at the National Wind Technology Center (NWTC) (Presentation)

    SciTech Connect

    Ela, E.

    2011-05-01

    In order to keep the electricity grid stable and the lights on, the power system relies on certain responses from its generating fleet. This presentation evaluates the potential for wind turbines and wind power plants to provide these services and assist the grid during critical times.

  12. Transcription Factor Arabidopsis Activating Factor1 Integrates Carbon Starvation Responses with Trehalose Metabolism.

    PubMed

    Garapati, Prashanth; Feil, Regina; Lunn, John Edward; Van Dijck, Patrick; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-09-01

    Plants respond to low carbon supply by massive reprogramming of the transcriptome and metabolome. We show here that the carbon starvation-induced NAC (for NO APICAL MERISTEM/ARABIDOPSIS TRANSCRIPTION ACTIVATION FACTOR/CUP-SHAPED COTYLEDON) transcription factor Arabidopsis (Arabidopsis thaliana) Transcription Activation Factor1 (ATAF1) plays an important role in this physiological process. We identified TREHALASE1, the only trehalase-encoding gene in Arabidopsis, as a direct downstream target of ATAF1. Overexpression of ATAF1 activates TREHALASE1 expression and leads to reduced trehalose-6-phosphate levels and a sugar starvation metabolome. In accordance with changes in expression of starch biosynthesis- and breakdown-related genes, starch levels are generally reduced in ATAF1 overexpressors but elevated in ataf1 knockout plants. At the global transcriptome level, genes affected by ATAF1 are broadly associated with energy and carbon starvation responses. Furthermore, transcriptional responses triggered by ATAF1 largely overlap with expression patterns observed in plants starved for carbon or energy supply. Collectively, our data highlight the existence of a positively acting feedforward loop between ATAF1 expression, which is induced by carbon starvation, and the depletion of cellular carbon/energy pools that is triggered by the transcriptional regulation of downstream gene regulatory networks by ATAF1.

  13. Nuclear Factor of Activated T Cells Transcription Factor Nfatp Controls Superantigen-Induced Lethal Shock

    PubMed Central

    Tsytsykova, Alla V.; Goldfeld, Anne E.

    2000-01-01

    Tumor necrosis factor α (TNF-α) is the key mediator of superantigen-induced T cell lethal shock. Here, we show that nuclear factor of activated T cells transcription factor, NFATp, controls susceptibility to superantigen-induced lethal shock in mice through its activation of TNF-α gene transcription. In NFATp-deficient mice, T cell stimulation leads to delayed induction and attenuation of TNF-α mRNA levels, decreased TNF-α serum levels, and resistance to superantigen-induced lethal shock. By contrast, after lipopolysaccharide (LPS) challenge, serum levels of TNF-α and susceptibility to shock are unaffected. These results demonstrate that NFATp is an essential activator of immediate early TNF-α gene expression in T cells and they present in vivo evidence of the inducer- and cell type–specific regulation of TNF-α gene expression. Furthermore, they suggest NFATp as a potential selective target in the treatment of superantigen-induced lethal shock. PMID:10952728

  14. Transcription Factor Arabidopsis Activating Factor1 Integrates Carbon Starvation Responses with Trehalose Metabolism1[OPEN

    PubMed Central

    Garapati, Prashanth; Feil, Regina; Lunn, John Edward; Van Dijck, Patrick; Balazadeh, Salma; Mueller-Roeber, Bernd

    2015-01-01

    Plants respond to low carbon supply by massive reprogramming of the transcriptome and metabolome. We show here that the carbon starvation-induced NAC (for NO APICAL MERISTEM/ARABIDOPSIS TRANSCRIPTION ACTIVATION FACTOR/CUP-SHAPED COTYLEDON) transcription factor Arabidopsis (Arabidopsis thaliana) Transcription Activation Factor1 (ATAF1) plays an important role in this physiological process. We identified TREHALASE1, the only trehalase-encoding gene in Arabidopsis, as a direct downstream target of ATAF1. Overexpression of ATAF1 activates TREHALASE1 expression and leads to reduced trehalose-6-phosphate levels and a sugar starvation metabolome. In accordance with changes in expression of starch biosynthesis- and breakdown-related genes, starch levels are generally reduced in ATAF1 overexpressors but elevated in ataf1 knockout plants. At the global transcriptome level, genes affected by ATAF1 are broadly associated with energy and carbon starvation responses. Furthermore, transcriptional responses triggered by ATAF1 largely overlap with expression patterns observed in plants starved for carbon or energy supply. Collectively, our data highlight the existence of a positively acting feedforward loop between ATAF1 expression, which is induced by carbon starvation, and the depletion of cellular carbon/energy pools that is triggered by the transcriptional regulation of downstream gene regulatory networks by ATAF1. PMID:26149570

  15. Female migrant sex workers in Moscow: gender and power factors and HIV risk.

    PubMed

    Weine, Stevan; Golobof, Alexandra; Bahromov, Mahbat; Kashuba, Adrianna; Kalandarov, Tohir; Jonbekov, Jonbek; Loue, Sana

    2013-01-01

    This study aimed to build formative knowledge regarding HIV risks in female migrant sex workers in Moscow, focusing on gender and power. This was a collaborative ethnographic study, informed by the theory of gender and power, in which researchers conducted minimally structured interviews with 24 female sex workers who were migrants to Moscow and who provided sexual services to male migrant laborers. Overall, the female migrant sex workers engaged in HIV risk behaviors and practiced inadequate HIV protection with their clients. These behaviors were shaped by gender and power factors in the realms of labor, behavior, and cathexis. In the labor realm, because some female migrants were unable to earn enough money to support their families, they were pushed or pulled into sex work providing service to male migrants. In the behavior realm, many female migrant sex workers were intimidated by their male clients, feared violence, and lacked access to women's health care and prevention. In the cathexis realm, many had a sense of shame, social isolation, emotional distress, and lacked basic HIV knowledge and prevention skills. To prevent HIV transmission requires addressing the gender and power factors that shape HIV/AIDS risks among female migrant sex workers through multilevel intervention strategies.

  16. Factors associated with active commuting to work among women.

    PubMed

    Bopp, Melissa; Child, Stephanie; Campbell, Matthew

    2014-01-01

    Active commuting (AC), the act of walking or biking to work, has notable health benefits though rates of AC remain low among women. This study used a social-ecological framework to examine the factors associated with AC among women. A convenience sample of employed, working women (n = 709) completed an online survey about their mode of travel to work. Individual, interpersonal, institutional, community, and environmental influences were assessed. Basic descriptive statistics and frequencies described the sample. Simple logistic regression models examined associations with the independent variables with AC participation and multiple logistic regression analysis determined the relative influence of social ecological factors on AC participation. The sample was primarily middle-aged (44.09±11.38 years) and non-Hispanic White (92%). Univariate analyses revealed several individual, interpersonal, institutional, community and environmental factors significantly associated with AC. The multivariable logistic regression analysis results indicated that significant factors associated with AC included number of children, income, perceived behavioral control, coworker AC, coworker AC normative beliefs, employer and community supports for AC, and traffic. The results of this study contribute to the limited body of knowledge on AC participation for women and may help to inform gender-tailored interventions to enhance AC behavior and improve health.

  17. Factors associated with active commuting to work among women.

    PubMed

    Bopp, Melissa; Child, Stephanie; Campbell, Matthew

    2014-01-01

    Active commuting (AC), the act of walking or biking to work, has notable health benefits though rates of AC remain low among women. This study used a social-ecological framework to examine the factors associated with AC among women. A convenience sample of employed, working women (n = 709) completed an online survey about their mode of travel to work. Individual, interpersonal, institutional, community, and environmental influences were assessed. Basic descriptive statistics and frequencies described the sample. Simple logistic regression models examined associations with the independent variables with AC participation and multiple logistic regression analysis determined the relative influence of social ecological factors on AC participation. The sample was primarily middle-aged (44.09±11.38 years) and non-Hispanic White (92%). Univariate analyses revealed several individual, interpersonal, institutional, community and environmental factors significantly associated with AC. The multivariable logistic regression analysis results indicated that significant factors associated with AC included number of children, income, perceived behavioral control, coworker AC, coworker AC normative beliefs, employer and community supports for AC, and traffic. The results of this study contribute to the limited body of knowledge on AC participation for women and may help to inform gender-tailored interventions to enhance AC behavior and improve health. PMID:24512572

  18. Interesting pressure dependence of power factor in BiTeI

    NASA Astrophysics Data System (ADS)

    Guo, San-Dong; Wang, Jian-Li

    2016-06-01

    We investigate pressure dependence of electronic structures and thermoelectric properties in BiTeI by using a modified Becke and Johnson exchange potential. Spin–orbit coupling (SOC) effects are also included due to giant Rashba splitting. Thermoelectric properties are illuminated through solving Boltzmann transport equations within the constant scattering time approximation. The calculated energy band gap of 0.36 eV agrees well with the experimental value of 0.38 eV. As the pressure increases, the energy band gap first decreases, and then increases. The Rashba energy has the opposite trend with the energy band gap. SOC has obvious detrimental influence on the power factor in both n-type and p-type doping. For low doping concentration, the power factor has the same trend with the energy band gap with increasing pressure, but shows a monotonic changing trend in high doping. It is found that the pressure can induce a significantly enhanced power factor in high n-type doping, which can be understood as pressure leading to two-dimensional-like density of states in the conduction bands. These results suggest that BiTeI may be a potential candidate for efficient thermoelectricity in n-type doping by pressure, turning an ordinary insulator into a topological insulator.

  19. Tissue factor activation: is disulfide bond switching a regulatory mechanism?

    PubMed Central

    Ghosh, Samit; Mandal, Samir K.

    2007-01-01

    A majority of tissue factor (TF) on cell surfaces exists in a cryptic form (ie, coagulation function inactive) but retains its functionality in cell signaling. Recent studies have suggested that cryptic TF contains unpaired cysteine thiols and that activation involves the formation of the disulfide bond Cys186-Cys 209 and that protein disulfide isomerase (PDI) regulates TF coagulant and signaling activities by targeting this disulfide bond. This study was carried out to investigate the validity of this novel concept. Although treatment of MDA 231 tumor cells, fibroblasts, and stimulated endothelial cells with the oxidizing agent HgCl2 markedly increased the cell-surface TF coagulant activity, the increase is associated with increased anionic phospholipids at the cell surface. Annexin V, which binds to anionic phospholipids, attenuated the increased TF coagulant activity. It is noteworthy that treatment of cells with reducing agents also increased the cell surface TF activity. No evidence was found for either detectable expression of PDI at the cell surface or association of TF with PDI. Furthermore, reduction of PDI with the gene silencing had no effect on either TF coagulant or cell signaling functions. Overall, the present data undermine the recently proposed hypothesis that PDI-mediated disulfide exchange plays a role in regulating TF procoagulant and cell signaling functions. PMID:17726162

  20. On the self-shielding factors in neutron activation analysis

    NASA Astrophysics Data System (ADS)

    Trkov, A.; Žerovnik, G.; Snoj, L.; Ravnik, M.

    2009-11-01

    Whenever the sample size in neutron activation analysis cannot be made small enough, self-shielding effects need to be taken into account. When several resonance absorbers are present in the sample, resonance interference must also be considered. Estimation of the self-shielding factors by the Monte Carlo technique is too cumbersome for routine application. Various simplified approaches were compared to rigorous Monte Carlo calculations, pointing out their potential limitations. Good results are obtained using self-shielding factors calculated from evaluated nuclear data libraries and tabulated as a function of the dilution cross-section. The dilution cross-section depends on the material composition and the sample dimensions through the equivalence principle, which is well known in reactor physics. Resonance interference is calculated by solving the neutron spectrum slowing-down equation from cross-sections in 640-group representation. The MATSSF code was written for the purpose and is available on request.

  1. 75 FR 62634 - Proposed Information Collection (Obligation to Report Factors Affecting Entitlement) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... AFFAIRS Proposed Information Collection (Obligation to Report Factors Affecting Entitlement) Activity... techniques or the use of other forms of information technology. Title: Obligation to Report Factors Affecting... entitlement factors. Individual factors such as income, marital status, and the beneficiary's number...

  2. 78 FR 46418 - Proposed Information Collection (Obligation To Report Factors Affecting Entitlement) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... AFFAIRS Proposed Information Collection (Obligation To Report Factors Affecting Entitlement) Activity... techniques or the use of other forms of information technology. Title: Obligation to Report Factors Affecting... entitlement factors. Individual factors such as income, marital status, and the beneficiary's number...

  3. Low-power sensor module for long-term activity monitoring.

    PubMed

    Leuenberger, Kaspar; Gassert, Roger

    2011-01-01

    Wearable sensor modules are a promising approach to collecting data on functional motor activities, both for repeated and long-term assessments, as well as to investigate the transfer of therapy to activities of daily living at home, but have so far either had limited sensing capabilities, or were not laid out for long-term monitoring. This paper presents ReSense, a miniature sensor unit optimized for long-term monitoring of functional activity. Inertial MEMS sensors capture accelerations along six degrees of freedom and a barometric pressure sensor serves as a precise altimeter. Data is written to an integrated memory card. The realized module measures Ø25 × 10 mm, weighs 10 g and can record continuously for 27 h at 25 Hz and over 22 h at 100 Hz. The integrated power-management system detects inactivity and extends the operating time by about a factor of two, as shown by initial 24 h recordings on five energetic healthy adults. The integrated barometric pressure sensor allowed to identify activities incorporating a change in altitude, such as going up/down stairs or riding an elevator. By taking into account data from the inertial sensors during the altitude changes, it becomes possible to distinguish between these two activities. PMID:22254785

  4. Power considerations for λ inflation factor in meta-analyses of genome-wide association studies.

    PubMed

    Georgiopoulos, Georgios; Evangelou, Evangelos

    2016-01-01

    The genomic control (GC) approach is extensively used to effectively control false positive signals due to population stratification in genome-wide association studies (GWAS). However, GC affects the statistical power of GWAS. The loss of power depends on the magnitude of the inflation factor (λ) that is used for GC. We simulated meta-analyses of different GWAS. Minor allele frequency (MAF) ranged from 0·001 to 0·5 and λ was sampled from two scenarios: (i) random scenario (empirically-derived distribution of real λ values) and (ii) selected scenario from simulation parameter modification. Adjustment for λ was considered under single correction (within study corrected standard errors) and double correction (additional λ corrected summary estimate). MAF was a pivotal determinant of observed power. In random λ scenario, double correction induced a symmetric power reduction in comparison to single correction. For MAF 1·2 and MAF >5%. Our results provide a quick but detailed index for power considerations of future meta-analyses of GWAS that enables a more flexible design from early steps based on the number of studies accumulated in different groups and the λ values observed in the single studies. PMID:27193946

  5. Secretion of platelet-activating factor by periovulatory ovine follicles

    SciTech Connect

    Alexander, B.M.; Van Kirk, E.A.; Murdoch, W.J. )

    1990-01-01

    Secretion of platelet-activating factor (PAF) in vitro by ovine follicles and ovarian interstitium obtained at various times before, during and after the endogenous preovulatory surge of luteinizing hormone (LH) and ovulation was quantified by radioimmunoassay. Release of PAF by the preovulatory follicle increased within 2 h after initiation of the surge of LH. Capacity for secretion of PAF was greatest at the time of ovulation, then declined thereafter. Production of PAF by ovarian interstitium throughout the periovulatory period was relatively low and did not change with time. It appears that PAF could act as an intrafollicular mediator in the mechanisms of ovulation and(or) luteinization.

  6. Hydrolysis of polyphosphoinositides in astrocytes by platelet-activating factor.

    PubMed

    Murphy, S; Welk, G

    1990-06-12

    In primary astrocyte cultures, picomolar concentrations of platelet-activating factor (1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine, PAF) evoked the formation of inositol phosphates (InsP), including inositol trisphosphate. This effect was not observed with the biologically inert lyso-PAF, nor in cells pretreated with phorbol myristate acetate to downregulate receptors. PAF at concentrations greater than or equal to 10(-9) M did not elevate InsP, suggesting some form of uncoupling of the receptor from phospholipase C. The responsiveness of astrocytes to PAF is further evidence for the role of these cells in the central nervous system response to trauma. PMID:2164941

  7. Rural children active trachoma risk factors and their interactions

    PubMed Central

    Muluneh, Essey Kebede; Zewotir, Temesgen; Bekele, Zerihun

    2016-01-01

    Introduction Trachoma is a serious public health problem in rural Ethiopia. The aim of this investigation was to provide in-depth statistical analysis of the risk factors associated with active trachoma among children of age 1-9 years of Kedida Gamela district, in Ethiopia. Methods A community based cross-sectional survey of trachoma was conducted in six selected rural kebeles of Kedida Gamela district, in Ethiopia from June 10-25, 2014. A total of 377 children (ages 1-9 years) were included in the study using two stage cluster sampling. All children were examined for trachoma by nurse data collectors supervised by ophthalmic supervisors using the WHO simplified clinical grading system. Ordinal survey logistic regression model was used to identify risk factors. Data analysis was done using SAS version 9.3. Results The best fit proportional odds model was identified to be the main effects and two-way and three-way interactios. Keeping cattle in the house was found to have a protective effect (OR=0.138, p-value=0.0003). The household wealth will have a more protective effect if the child attends school. Washing face with soap and water once a day has equivalent protective effect as washing face three-or-more times a day with water only. Conclusion The 2-way and 3-way significant interactions effects unfolded some of the controversies derived from similar studies on trachoma risk factors. The findings would suggest integrated effort to address two or three factors simultaneously is more fruitful than any novel intervention targeted to address a single risk factor. PMID:27642466

  8. Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude- and velocity-dependent characteristics of activa...

  9. Activation of coagulation factor XI, without detectable contact activation in dengue haemorrhagic fever.

    PubMed

    van Gorp, E C; Minnema, M C; Suharti, C; Mairuhu, A T; Brandjes, D P; ten Cate, H; Hack, C E; Meijers, J C

    2001-04-01

    A prospective cohort study was performed in 50 patients with dengue haemorrhagic fever (DHF) to determine the potential role of the contact activation system and factor XI activation (intrinsic pathway) in the coagulation disorders in DHF. To establish whether TAFI (thrombin-activatable fibrinolysis inhibitor) was involved in the severity of the coagulation disorders, the TAFI antigen and activity levels were also determined. Markers of contact activation (kallikrein--C1-inhibitor complexes), the intrinsic pathway of coagulation (factor XIa--C1-inhibitor complexes) and TAFI were measured and correlated to thrombin generation markers (thrombin--anti-thrombin complexes (TAT), prothrombin fragment 1+2 (F1+2)) and a marker for fibrinolysis [plasmin--alpha 2--anti-plasmin complexes (PAP)]. Activation of the intrinsic pathway of coagulation was clearly demonstrated by elevated levels of factor XIa--C1-inhibitor complexes, without evidence of contact activation, reflected by undetectable kallikrein--C1-inhibitor complexes. Both TAFI antigen and activity levels were decreased in all patients, which may contribute to the severity of bleeding complications in DHF because of the impaired capacity of the coagulation system to protect the fibrin clot from fibrinolysis. These findings in a human viral infection model are in accordance with earlier findings in bacterial sepsis.

  10. Nuclear factor Y regulates ancient budgerigar hepadnavirus core promoter activity.

    PubMed

    Shen, Zhongliang; Liu, Yanfeng; Luo, Mengjun; Wang, Wei; Liu, Jing; Liu, Wei; Pan, Shaokun; Xie, Youhua

    2016-09-16

    Endogenous viral elements (EVE) in animal genomes are the fossil records of ancient viruses and provide invaluable information on the origin and evolution of extant viruses. Extant hepadnaviruses include avihepadnaviruses of birds and orthohepadnaviruses of mammals. The core promoter (Cp) of hepadnaviruses is vital for viral gene expression and replication. We previously identified in the budgerigar genome two EVEs that contain the full-length genome of an ancient budgerigar hepadnavirus (eBHBV1 and eBHBV2). Here, we found eBHBV1 Cp and eBHBV2 Cp were active in several human and chicken cell lines. A region from nt -85 to -11 in eBHBV1 Cp was critical for the promoter activity. Bioinformatic analysis revealed a putative binding site of nuclear factor Y (NF-Y), a ubiquitous transcription factor, at nt -64 to -50 in eBHBV1 Cp. The NF-Y core binding site (ATTGG, nt -58 to -54) was essential for eBHBV1 Cp activity. The same results were obtained with eBHBV2 Cp and duck hepatitis B virus Cp. The subunit A of NF-Y (NF-YA) was recruited via the NF-Y core binding site to eBHBV1 Cp and upregulated the promoter activity. Finally, the NF-Y core binding site is conserved in the Cps of all the extant avihepadnaviruses but not of orthohepadnaviruses. Interestingly, a putative and functionally important NF-Y core binding site is located at nt -21 to -17 in the Cp of human hepatitis B virus. In conclusion, our findings have pinpointed an evolutionary conserved and functionally critical NF-Y binding element in the Cps of avihepadnaviruses.

  11. Nuclear factor Y regulates ancient budgerigar hepadnavirus core promoter activity.

    PubMed

    Shen, Zhongliang; Liu, Yanfeng; Luo, Mengjun; Wang, Wei; Liu, Jing; Liu, Wei; Pan, Shaokun; Xie, Youhua

    2016-09-16

    Endogenous viral elements (EVE) in animal genomes are the fossil records of ancient viruses and provide invaluable information on the origin and evolution of extant viruses. Extant hepadnaviruses include avihepadnaviruses of birds and orthohepadnaviruses of mammals. The core promoter (Cp) of hepadnaviruses is vital for viral gene expression and replication. We previously identified in the budgerigar genome two EVEs that contain the full-length genome of an ancient budgerigar hepadnavirus (eBHBV1 and eBHBV2). Here, we found eBHBV1 Cp and eBHBV2 Cp were active in several human and chicken cell lines. A region from nt -85 to -11 in eBHBV1 Cp was critical for the promoter activity. Bioinformatic analysis revealed a putative binding site of nuclear factor Y (NF-Y), a ubiquitous transcription factor, at nt -64 to -50 in eBHBV1 Cp. The NF-Y core binding site (ATTGG, nt -58 to -54) was essential for eBHBV1 Cp activity. The same results were obtained with eBHBV2 Cp and duck hepatitis B virus Cp. The subunit A of NF-Y (NF-YA) was recruited via the NF-Y core binding site to eBHBV1 Cp and upregulated the promoter activity. Finally, the NF-Y core binding site is conserved in the Cps of all the extant avihepadnaviruses but not of orthohepadnaviruses. Interestingly, a putative and functionally important NF-Y core binding site is located at nt -21 to -17 in the Cp of human hepatitis B virus. In conclusion, our findings have pinpointed an evolutionary conserved and functionally critical NF-Y binding element in the Cps of avihepadnaviruses. PMID:27501758

  12. Activation of clotting factor XI without detectable contact activation in experimental human endotoxemia.

    PubMed

    Minnema, M C; Pajkrt, D; Wuillemin, W A; Roem, D; Bleeker, W K; Levi, M; van Deventer, S J; Hack, C E; ten Cate, H

    1998-11-01

    Evidence of factor XI (FXI) activation in vivo is scarce. In addition, it remains uncertain whether thrombin, factor XIIa (FXIIa), or perhaps another protease is responsible for FXI conversion. We investigated the activation of FXI in eight healthy volunteers after infusion of a low dose of endotoxin (4 ng/kg of body weight). Activation of prekallikrein FXII, FXI, and prothrombin was measured with sensitive enzyme-linked immunosorbent assays (ELISAs), and FXI activation was measured with a novel enzyme capture assay that detects noncomplexed FXIa. Activation of FXI was apparent with a significant plasma peak level of noncomplexed FXIa of 10 to 11 pmol/L at 1 and 2 hours after endotoxin infusion, followed by a gradual increase in FXIa-FXIa inhibitor complexes, measured in the ELISAs, with a summit of 11 to 15 pmol/L at 6 and 24 hours, respectively. In accordance with previous studies, thrombin generation was detected 1 hour after endotoxin infusion to become maximal after 3 to 4 hours. In contrast, we did not find any evidence of contact activation, because markers of activation of prekallikrein and FXII remained undetectable. From the FXIa data a theoretical model was constructed which suggested that inhibition of FXIa does not take place in the plasma compartment, but is localized on a surface. These data provide the first evidence for FXI activation in low-grade endotoxemia and suggest that FXI is activated independently of FXII.

  13. A basophil-activating factor from human T lymphocytes.

    PubMed Central

    Goetzl, E J; Foster, D W; Payan, D G

    1984-01-01

    Human T lymphocytes stimulated with phytohaemagglutinin (PHA) or streptokinase-streptodornase (SK-SD) generate an activity which elicits non-cytotoxic histamine release from human basophils. Filtration of the T lymphocyte-derived activity on columns of Sephadex G-100 and Fractogel 55F sequentially revealed one predominant basophil-activating factor of mol. wt. 70,000-90,000, that was designated BAF-T. BAF-T was composed of two acidic proteins of approximate pI 4.4 and 5.2-5.5, as assessed by isoelectric focusing. The distinction of BAF-T from IgE was confirmed by the failure of BAF-T to bind to an anti-IgE affinity column and the capacity of BAF-T to release histamine maximally from basophils desensitized to IgE-dependent stimuli. The inability of BAF-T to release histamine from human lung mast cells and dog cutaneous mastocytoma cells suggests target cell specificity. The source and activity of BAF-T are consistent with a specific contribution of this mediator to human cellular immune and hypersensitivity responses involving T lymphocytes and basophils. PMID:6208144

  14. Arhgap36-dependent activation of Gli transcription factors

    PubMed Central

    Rack, Paul G.; Ni, Jun; Payumo, Alexander Y.; Nguyen, Vien; Crapster, J. Aaron; Hovestadt, Volker; Kool, Marcel; Jones, David T. W.; Mich, John K.; Firestone, Ari J.; Pfister, Stefan M.; Cho, Yoon-Jae; Chen, James K.

    2014-01-01

    Hedgehog (Hh) pathway activation and Gli-dependent transcription play critical roles in embryonic patterning, tissue homeostasis, and tumorigenesis. By conducting a genome-scale cDNA overexpression screen, we have identified the Rho GAP family member Arhgap36 as a positive regulator of the Hh pathway in vitro and in vivo. Arhgap36 acts in a Smoothened (Smo)-independent manner to inhibit Gli repressor formation and to promote the activation of full-length Gli proteins. Arhgap36 concurrently induces the accumulation of Gli proteins in the primary cilium, and its ability to induce Gli-dependent transcription requires kinesin family member 3a and intraflagellar transport protein 88, proteins that are essential for ciliogenesis. Arhgap36 also functionally and biochemically interacts with Suppressor of Fused. Transcriptional profiling further reveals that Arhgap36 is overexpressed in murine medulloblastomas that acquire resistance to chemical Smo inhibitors and that ARHGAP36 isoforms capable of Gli activation are up-regulated in a subset of human medulloblastomas. Our findings reveal a new mechanism of Gli transcription factor activation and implicate ARHGAP36 dysregulation in the onset and/or progression of GLI-dependent cancers. PMID:25024229

  15. ERC product improvement activities for direct fuel cell power plants

    SciTech Connect

    Bentley, C.; Carlson, G.; Doyon, J.

    1995-08-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  16. ERC product improvement activities for direct fuel cell power plants

    SciTech Connect

    Maru, H.C.; Farooque, M.; Bentley, C.

    1995-12-01

    This program is designed to advance the carbonate fuel cell technology from the current power plant demonstration status to the commercial design in an approximately five-year period. The specific objectives which will allow attainment of the overall program goal are: (1) Define market-responsive power plant requirements and specifications, (2) Establish the design for a multifuel, low-cost, modular, market-responsive power plant, (3) Resolve power plant manufacturing issues and define the design for the commercial manufacturing facility, (4) Define the stack and BOP equipment packaging arrangement and define module designs, (5) Acquire capability to support developmental testing of stacks and BOP equipment as required to prepare for commercial design, and (6) Resolve stack and BOP equipment technology issues and design, build, and field test a modular commercial prototype power plant to demonstrate readiness for commercial entry. A seven-task program, dedicated to attaining objective(s) in the areas noted above, was initiated in December 1994. Accomplishments of the first six months are discussed in this paper.

  17. Immersion factors affecting perception and behaviour in a virtual reality power wheelchair simulator.

    PubMed

    Alshaer, Abdulaziz; Regenbrecht, Holger; O'Hare, David

    2017-01-01

    Virtual Reality based driving simulators are increasingly used to train and assess users' abilities to operate vehicles in a controlled and safe way. For the development of those simulators it is important to identify and evaluate design factors affecting perception, behaviour, and driving performance. In an exemplary power wheelchair simulator setting we identified the three immersion factors display type (head-mounted display v monitor), ability to freely change the field of view (FOV), and the visualisation of the user's avatar as potentially affecting perception and behaviour. In a study with 72 participants we found all three factors affected the participants' sense of presence in the virtual environment. In particular the display type significantly affected both perceptual and behavioural measures whereas FOV only affected behavioural measures. Our findings could guide future Virtual Reality simulator designers to evoke targeted user behaviours and perceptions. PMID:27633192

  18. Immersion factors affecting perception and behaviour in a virtual reality power wheelchair simulator.

    PubMed

    Alshaer, Abdulaziz; Regenbrecht, Holger; O'Hare, David

    2017-01-01

    Virtual Reality based driving simulators are increasingly used to train and assess users' abilities to operate vehicles in a controlled and safe way. For the development of those simulators it is important to identify and evaluate design factors affecting perception, behaviour, and driving performance. In an exemplary power wheelchair simulator setting we identified the three immersion factors display type (head-mounted display v monitor), ability to freely change the field of view (FOV), and the visualisation of the user's avatar as potentially affecting perception and behaviour. In a study with 72 participants we found all three factors affected the participants' sense of presence in the virtual environment. In particular the display type significantly affected both perceptual and behavioural measures whereas FOV only affected behavioural measures. Our findings could guide future Virtual Reality simulator designers to evoke targeted user behaviours and perceptions.

  19. Epidermal Platelet-activating Factor Receptor Activation and Ultraviolet B Radiation Result in Synergistic Tumor Necrosis Factor-alpha Production

    PubMed Central

    Wolverton, Jay E.; Al-Hassani, Mohammed; Yao, Yongxue; Zhang, Qiwei; Travers, Jeffrey B.

    2010-01-01

    Ultraviolet B radiation (UVB) is a potent stimulator of epidermal cytokine production which has been implicated in photoaggravated dermatoses. In addition to cytokines such as tumor necrosis factor-α (TNF-α), UVB generates bioactive lipids including platelet-activating factor (PAF). Our previous studies have demonstrated that UVB-mediated production of keratinocyte TNF-α is in part due to PAF. The current studies use a human PAF-receptor (PAF-R) negative epithelial cell line transduced with PAF-Rs and PAF–R-deficient mice to demonstrate that activation of the epidermal PAF-R along with UVB irradiation results in a synergistic production of TNF-α. It should be noted that PAF-R effects are mimicked by the protein kinase C (PKC) agonist phorbol myristic acetate, and are inhibited by pharmacological antagonists of the PKC gamma isoenzyme. These studies suggest that concomitant PAF-R activation and UVB irradiation results in a synergistic production of the cytokine TNF-α which is mediated in part via PKC. These studies provide a novel potential mechanism for photosensitivity responses. PMID:19769579

  20. Arabidopsis sigma factor binding proteins are activators of the WRKY33 transcription factor in plant defense.

    PubMed

    Lai, Zhibing; Li, Ying; Wang, Fei; Cheng, Yuan; Fan, Baofang; Yu, Jing-Quan; Chen, Zhixiang

    2011-10-01

    Necrotrophic pathogens are important plant pathogens that cause many devastating plant diseases. Despite their impact, our understanding of the plant defense response to necrotrophic pathogens is limited. The WRKY33 transcription factor is important for plant resistance to necrotrophic pathogens; therefore, elucidation of its functions will enhance our understanding of plant immunity to necrotrophic pathogens. Here, we report the identification of two WRKY33-interacting proteins, nuclear-encoded SIGMA FACTOR BINDING PROTEIN1 (SIB1) and SIB2, which also interact with plastid-encoded plastid RNA polymerase SIGMA FACTOR1. Both SIB1 and SIB2 contain an N-terminal chloroplast targeting signal and a putative nuclear localization signal, suggesting that they are dual targeted. Bimolecular fluorescence complementation indicates that WRKY33 interacts with SIBs in the nucleus of plant cells. Both SIB1 and SIB2 contain a short VQ motif that is important for interaction with WRKY33. The two VQ motif-containing proteins recognize the C-terminal WRKY domain and stimulate the DNA binding activity of WRKY33. Like WRKY33, both SIB1 and SIB2 are rapidly and strongly induced by the necrotrophic pathogen Botrytis cinerea. Resistance to B. cinerea is compromised in the sib1 and sib2 mutants but enhanced in SIB1-overexpressing transgenic plants. These results suggest that dual-targeted SIB1 and SIB2 function as activators of WRKY33 in plant defense against necrotrophic pathogens.

  1. Thyroid Transcription Factor 1 Reprograms Angiogenic Activities of Secretome

    PubMed Central

    Wood, Lauren W.; Cox, Nicole I.; Phelps, Cody A.; Lai, Shao-Chiang; Poddar, Arjun; Talbot, Conover; Mu, David

    2016-01-01

    Through both gain- and loss-of-TTF-1 expression strategies, we show that TTF-1 positively regulates vascular endothelial growth factor (VEGF) and that the VEGF promoter element contains multiple TTF-1-responsive sequences. The major signaling receptor for VEGF, i.e VEGFR2, also appears to be under a direct and positive regulation of TTF-1. The TTF-1-dependent upregulation of VEGF was moderately sensitive to rapamycin, implicating a partial involvement of mammalian target of rapamycin (mTOR). However, hypoxia did not further increase the secreted VEGF level of the TTF-1+ lung cancer cells. The TTF-1-induced VEGF upregulation occurs in both compartments (exosomes and exosome-depleted media (EDM)) of the conditioned media. Surprisingly, the EDM of TTF-1+ lung cancer cells (designated EDM-TTF-1+) displayed an anti-angiogenic activity in the endothelial cell tube formation assay. Mechanistic studies suggest that the increased granulocyte-macrophage colony-stimulating factor (GM-CSF) level in the EDM-TTF-1+ conferred the antiangiogenic activities. In human lung cancer, the expression of TTF-1 and GM-CSF exhibits a statistically significant and positive correlation. In summary, this study provides evidence that TTF-1 may reprogram lung cancer secreted proteome into an antiangiogenic state, offering a novel basis to account for the long-standing observation of favorable prognosis associated with TTF-1+ lung adenocarcinomas. PMID:26912193

  2. Thyroid Transcription Factor 1 Reprograms Angiogenic Activities of Secretome.

    PubMed

    Wood, Lauren W; Cox, Nicole I; Phelps, Cody A; Lai, Shao-Chiang; Poddar, Arjun; Talbot, Conover; Mu, David

    2016-02-25

    Through both gain- and loss-of-TTF-1 expression strategies, we show that TTF-1 positively regulates vascular endothelial growth factor (VEGF) and that the VEGF promoter element contains multiple TTF-1-responsive sequences. The major signaling receptor for VEGF, i.e VEGFR2, also appears to be under a direct and positive regulation of TTF-1. The TTF-1-dependent upregulation of VEGF was moderately sensitive to rapamycin, implicating a partial involvement of mammalian target of rapamycin (mTOR). However, hypoxia did not further increase the secreted VEGF level of the TTF-1(+) lung cancer cells. The TTF-1-induced VEGF upregulation occurs in both compartments (exosomes and exosome-depleted media (EDM)) of the conditioned media. Surprisingly, the EDM of TTF-1(+) lung cancer cells (designated EDM-TTF-1(+)) displayed an anti-angiogenic activity in the endothelial cell tube formation assay. Mechanistic studies suggest that the increased granulocyte-macrophage colony-stimulating factor (GM-CSF) level in the EDM-TTF-1(+) conferred the antiangiogenic activities. In human lung cancer, the expression of TTF-1 and GM-CSF exhibits a statistically significant and positive correlation. In summary, this study provides evidence that TTF-1 may reprogram lung cancer secreted proteome into an antiangiogenic state, offering a novel basis to account for the long-standing observation of favorable prognosis associated with TTF-1(+) lung adenocarcinomas.

  3. Influence of abiotic factors on the antimicrobial activity of chitosan.

    PubMed

    Tavaria, Freni K; Costa, Eduardo M; Gens, Eduardo J; Malcata, Francisco Xavier; Pintado, Manuela E

    2013-12-01

    In an effort to bypass the adverse secondary effects attributed to the traditional therapeutic approaches used to treat skin disorders (such as atopic dermatitis), alternative antimicrobials have recently been suggested. One such antimicrobial is chitosan, owing to the already proved biological properties associated with its use. However, the influence of abiotic factors on such activities warrants evaluation. This research effort assessed the antimicrobial activity of chitosan upon skin microorganisms (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) in vitro when subject to a combination of different abiotic factors such as pH, ionic strength, organic acids and free fatty acids. Free fatty acids, ionic strength and pH significantly affected chitosan's capability of reducing the viable numbers of S. aureus. This antimicrobial action was potentiated in the presence of palmitic acid and a lower ionic strength (0.2% NaCl), while a higher ionic strength (0.4% NaCl) favored chitosan's action upon the reduction of viable numbers of S. epidermidis and E. coli. Although further studies are needed, these preliminary results advocate that chitosan can in the future be potentially considered as an antimicrobial of choice when handling symptoms associated with atopic dermatitis.

  4. Influence of abiotic factors on the antimicrobial activity of chitosan.

    PubMed

    Tavaria, Freni K; Costa, Eduardo M; Gens, Eduardo J; Malcata, Francisco Xavier; Pintado, Manuela E

    2013-12-01

    In an effort to bypass the adverse secondary effects attributed to the traditional therapeutic approaches used to treat skin disorders (such as atopic dermatitis), alternative antimicrobials have recently been suggested. One such antimicrobial is chitosan, owing to the already proved biological properties associated with its use. However, the influence of abiotic factors on such activities warrants evaluation. This research effort assessed the antimicrobial activity of chitosan upon skin microorganisms (Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli) in vitro when subject to a combination of different abiotic factors such as pH, ionic strength, organic acids and free fatty acids. Free fatty acids, ionic strength and pH significantly affected chitosan's capability of reducing the viable numbers of S. aureus. This antimicrobial action was potentiated in the presence of palmitic acid and a lower ionic strength (0.2% NaCl), while a higher ionic strength (0.4% NaCl) favored chitosan's action upon the reduction of viable numbers of S. epidermidis and E. coli. Although further studies are needed, these preliminary results advocate that chitosan can in the future be potentially considered as an antimicrobial of choice when handling symptoms associated with atopic dermatitis. PMID:24330167

  5. Activation of factor IX bound to cultured bovine aortic endothelial cells.

    PubMed Central

    Stern, D M; Drillings, M; Kisiel, W; Nawroth, P; Nossel, H L; LaGamma, K S

    1984-01-01

    Previous studies have shown that factor IX and its activated form, factor IXa, bind to cultured vascular endothelial cells and that cell-bound factor IXa retains its procoagulant activity. The present studies provide evidence that factor IX bound to cultured bovine aortic endothelial cells can be activated. Factor IX activation was assessed by finding cleavage of the factor IX molecule on NaDodSO4/polyacrylamide gel electrophoresis and by the generation of procoagulant activity as assessed by thrombin-treated factor VIII-dependent generation of factor Xa activity. Cell-bound factor IX (0.8 micrograms per 4 X 10(8) cells per ml) could be activated by factor XIa (5 micrograms/ml) or by factor VIIa (0.1 micrograms/ml) without exogenous tissue factor when endothelial cells were treated with phorbol ester and acquired tissue factor-like procoagulant activity. Regardless of how factor IX was activated, the cell-bound factor IXa required thrombin-treated factor VIII and calcium, but not exogenous phospholipid, to activate factor X. In further experiments, factor X bound to endothelial cells specifically and reversibly with a dependence on calcium and with a lower affinity (half-maximal at 480 nM) than factor IX. At saturation, 9.1 X 10(6) factor X molecules were bound per cell. After activation of factor X by factor IXa, approximately 50% of the factor Xa formed could be eluted from the cells by 10 mM EDTA, suggesting that the factor Xa was cell associated. These observations indicate that endothelial cells can bind and promote the activation of factors IX and X in the absence of platelets or exogenous phospholipid. PMID:6608105

  6. Extremal harmonic active control of power for a monocylinder hybrid powertrain

    NASA Astrophysics Data System (ADS)

    Gauthier, Jean-Philippe; Micheau, Philippe; Cauet, Sébastien; Coirault, Patrick; Martin, Pascal

    2011-11-01

    This article presents a real-life application for the extremal harmonic active control of power [1] applied on a hybrid engine setup. The active control was adapted for a hybrid powertrain constituted of a one-cylinder diesel engine coupled with a permanent magnet synchronous machine. The problem was formulated in the harmonic domain and the control objective was to extremalize energetic criterions. Three criterions were considered: minimizing the speed ripple of the engine, maximizing the mechanical reactive power (mechanical impedance adaptation) and maximizing the active electric power for energy harvesting. The results show that, for the first and second orders of the ripple, speed oscillations can be completely cancelled and reactive power and active power can be optimized on-line. The implicit extremal controller converged rapidly, remaining stable even when the mean engine speed changed abruptly. These results confirm the robustness and the applicability of the extremal harmonic active control for industrial applications.

  7. A factorization approach to next-to-leading-power threshold logarithms

    NASA Astrophysics Data System (ADS)

    Bonocore, D.; Laenen, E.; Magnea, L.; Melville, S.; Vernazza, L.; White, C. D.

    2015-06-01

    Threshold logarithms become dominant in partonic cross sections when the selected final state forces gluon radiation to be soft or collinear. Such radiation factorizes at the level of scattering amplitudes, and this leads to the resummation of threshold logarithms which appear at leading power in the threshold variable. In this paper, we consider the extension of this factorization to include effects suppressed by a single power of the threshold variable. Building upon the Low-Burnett-Kroll-Del Duca (LBKD) theorem, we propose a decomposition of radiative amplitudes into universal building blocks, which contain all effects ultimately responsible for next-to-leading-power (NLP) threshold logarithms in hadronic cross sections for electroweak annihilation processes. In particular, we provide a NLO evaluation of the radiative jet function, responsible for the interference of next-to-soft and collinear effects in these cross sections. As a test, using our expression for the amplitude, we reproduce all abelian-like NLP threshold logarithms in the NNLO Drell-Yan cross section, including the interplay of real and virtual emissions. Our results are a significant step towards developing a generally applicable resummation formalism for NLP threshold effects, and illustrate the breakdown of next-to-soft theorems for gauge theory amplitudes at loop level.

  8. Thermoelectric power factor performance of Bi85Sb15/graphene composite

    NASA Astrophysics Data System (ADS)

    El-Asfoury, Mohamed S.; Nasr, Mohamed N. A.; Nakamura, Koichi; Abdel-Moneim, Ahmed

    2016-04-01

    Composite materials based on Bi85Sb15 with commercial graphene (Gr) nanoparticles have been synthesized by mechanical alloying and hot isostatic pressing. The effect of different amount of Gr nanoparticles (x = 0.02, 0.04, 0.06, and 0.08 wt %) on the thermoelectric properties of (Bi85Sb15)1- x Gr x composite was investigated. X-ray diffraction and scanning electron microscopy were carried out for the structure characterization of the composites. Transport properties, including electrical resistivity, Seebeck coefficient, and calculated power factor, were investigated and their variations were discussed with regard to microstructures in the temperature range of 173-373 K. Resistivity significantly declines in the sample with x = 0.04 wt % Gr, and the enhancement was 7% at 230 K and reached about 7.6% at room temperature. With 0.08 wt % Gr, a high absolute value of the Seebeck coefficient was observed. The power factor reaches its maximum of 3.7 × 10-3 W·m-1·K-2 with x = 0.08 wt % at 173 K. The results reflect that this synthesis process can be a powerful method of obtaining homogeneous Bi-Sb thermoelectric composite materials rapidly and at low cost. In addition, the demand for uniform coherent composites was significant because of their high-performance transport properties.

  9. Coagulation factor V mediates inhibition of tissue factor signaling by activated protein C in mice.

    PubMed

    Liang, Hai Po H; Kerschen, Edward J; Basu, Sreemanti; Hernandez, Irene; Zogg, Mark; Jia, Shuang; Hessner, Martin J; Toso, Raffaella; Rezaie, Alireza R; Fernández, José A; Camire, Rodney M; Ruf, Wolfram; Griffin, John H; Weiler, Hartmut

    2015-11-19

    The key effector molecule of the natural protein C pathway, activated protein C (aPC), exerts pleiotropic effects on coagulation, fibrinolysis, and inflammation. Coagulation-independent cell signaling by aPC appears to be the predominant mechanism underlying its highly reproducible therapeutic efficacy in most animal models of injury and infection. In this study, using a mouse model of Staphylococcus aureus sepsis, we demonstrate marked disease stage-specific effects of the anticoagulant and cell signaling functions of aPC. aPC resistance of factor (f)V due to the R506Q Leiden mutation protected against detrimental anticoagulant effects of aPC therapy but also abrogated the anti-inflammatory and mortality-reducing effects of the signaling-selective 5A-aPC variant that has minimal anticoagulant function. We found that procofactor V (cleaved by aPC at R506) and protein S were necessary cofactors for the aPC-mediated inhibition of inflammatory tissue-factor signaling. The anti-inflammatory cofactor function of fV involved the same structural features that govern its cofactor function for the anticoagulant effects of aPC, yet its anti-inflammatory activities did not involve proteolysis of activated coagulation factors Va and VIIIa. These findings reveal a novel biological function and mechanism of the protein C pathway in which protein S and the aPC-cleaved form of fV are cofactors for anti-inflammatory cell signaling by aPC in the context of endotoxemia and infection.

  10. On the nature of ULF wave power during nightside auroral activations and substorms: 2. Temporal evolution

    NASA Astrophysics Data System (ADS)

    Rae, I. J.; Murphy, K. R.; Watt, C. E. J.; Mann, I. R.

    2011-01-01

    We present a statistical analysis of the time evolution of ground magnetic fluctuations in three (12-48 s, 24-96 s and 48-192 s) period bands during nightside auroral activations. We use an independently derived auroral activation list composed of both substorms and pseudo-breakups to provide an estimate of the activation times of nightside aurora during periods with comprehensive ground magnetometer coverage. One hundred eighty-one events in total are studied to demonstrate the statistical nature of the time evolution of magnetic wave power during the ˜30 min surrounding auroral activations. We find that the magnetic wave power is approximately constant before an auroral activation, starts to grow up to 90 s prior to the optical onset time, maximizes a few minutes after the auroral activation, then decays slightly to a new, and higher, constant level. Importantly, magnetic ULF wave power always remains elevated after an auroral activation, whether it is a substorm or a pseudo-breakup. We subsequently divide the auroral activation list into events that formed part of ongoing auroral activity and events that had little preceding geomagnetic activity. We find that the evolution of wave power in the ˜10-200 s period band essentially behaves in the same manner through auroral onset, regardless of event type. The absolute power across ULF wave bands, however, displays a power law-like dependency throughout a 30 min period centered on auroral onset time. We also find evidence of a secondary maximum in wave power at high latitudes ˜10 min following isolated substorm activations. Most significantly, we demonstrate that magnetic wave power levels persist after auroral activations for ˜10 min, which is consistent with recent findings of wave-driven auroral precipitation during substorms. This suggests that magnetic wave power and auroral particle precipitation are intimately linked and key components of the substorm onset process.

  11. Purification of human plasma platelet-activating factor acetylhydrolase

    SciTech Connect

    Stafforini, D.M.; Prescott, S.M.; McIntyre, T.M.

    1986-05-01

    Platelet-activating factor (PAF;1-0-alkyl-2-acetyl-sn-glycero-3-phosphocholine is synthesized by a variety of cells. It induces hypotension, and activates platelets, neutrophils, and macrophages at nanomolar concentrations. Removal of the acetate abolishes biological activity, and is catalyzed by a specific PAF acetylhydrolase present in plasma and tissues. The authors developed a rapid assay, based on separation of (/sup 3/H)acetate from (/sup 3/H-acetyl)PAF by reversed-phase chromatography. In human plasma the enzyme exhibits an apparent Km of 5.7..mu..M, with a Vmax of 0.027..mu..mol/h/mg. Ultracentrifugation in density gradients showed that 30% of the activity is associated with high density lipoproteins (HDL) and 70% with low density lipoproteins (LDL). The enzyme was purified from LDL by precipitation with Na phosphotungstate and MgCl/sub 2/, solubilization with Tween 20, column chromatography and electrophoresis. This procedure resulted in a preparation that was 21,000-fold purified from plasma (spec. act. 575..mu..mol/h/mg) with a recovery of 10%. The purified enzyme has a molecular weight of about 43,000, a broad pH optimum (peak 7.5-8.0), and a pl of 4.6. It has greater activity when PAF is in a micellar, as compared to monomeric, and exhibits surface dilution kinetics, which may be important in vivo. The purification and characterization of this enzyme will allow detailed studies of its role in PAF metabolism.

  12. Crystal Structure of Human Plasma Platelet-Activating Factor Acetylhydrolase

    SciTech Connect

    Samanta, U.; Bahnson, B

    2008-01-01

    Human plasma platelet-activating factor (PAF) acetylhydrolase functions by reducing PAF levels as a general anti-inflammatory scavenger and is linked to anaphylactic shock, asthma, and allergic reactions. The enzyme has also been implicated in hydrolytic activities of other pro-inflammatory agents, such as sn-2 oxidatively fragmented phospholipids. This plasma enzyme is tightly bound to low and high density lipoprotein particles and is also referred to as lipoprotein-associated phospholipase A{sub 2}. The crystal structure of this enzyme has been solved from x-ray diffraction data collected to a resolution of 1.5{angstrom}. It has a classic lipase {alpha}/{beta}-hydrolase fold, and it contains a catalytic triad of Ser{sup 273}, His{sup 351}, and Asp{sup 296}. Two clusters of hydrophobic residues define the probable interface-binding region, and a prediction is given of how the enzyme is bound to lipoproteins. Additionally, an acidic patch of 10 carboxylate residues and a neighboring basic patch of three residues are suggested to play a role in high density lipoprotein/low density lipoprotein partitioning. A crystal structure is also presented of PAF acetylhydrolase reacted with the organophosphate compound paraoxon via its active site Ser{sup 273}. The resulting diethyl phosphoryl complex was used to model the tetrahedral intermediate of the substrate PAF to the active site. The model of interface binding begins to explain the known specificity of lipoprotein-bound substrates and how the active site can be both close to the hydrophobic-hydrophilic interface and at the same time be accessible to the aqueous phase.

  13. Associations between Socio-Motivational Factors, Physical Education Activity Levels and Physical Activity Behavior among Youth

    ERIC Educational Resources Information Center

    Ning, Weihong; Gao, Zan; Lodewyk, Ken

    2012-01-01

    This study examined the relationships between established socio-motivational factors and children's physical activity levels daily and during physical education classes. A total of 307 middle school students (149 boys, 158 girls) from a suburban public school in the Southern United States participated in this study. Participants completed…

  14. Cooperative Voltage Control Method by Power Factor Control of PV Systems and LRT

    NASA Astrophysics Data System (ADS)

    Kawasaki, Shoji; Kanemoto, Noriaki; Taoka, Hisao; Matsuki, Junya; Hayashi, Yasuhiro

    Recently, the number of system interconnection of the renewable energy sources (RES) such as the photovoltaic generation (PV) and wind power generation is increasing drastically, and there is in danger of changing the voltages in a distribution system by the precipitous output variation of RESs. In this study, the authors propose one voltage control method of the distribution system by the power factor control of plural PV systems in consideration of cooperation with the load ratio control transformer (LRT) of laggard control response installed beforehand in the distribution system. In the proposed method, the slow voltage variation is controlled by LRT, and the steep voltage variation uncontrollable by LRT is controlled by plural PV systems, as a result, all the node voltages are controllable within the proper limits. In order to verify the validity of the proposed method, the numerical calculations are carried out by using an analytical model of distribution system which interconnected PV systems.

  15. Band structure engineering through orbital interaction for enhanced thermoelectric power factor

    SciTech Connect

    Zhu, Hong; Sun, Wenhao; Ceder, Gerbrand; Armiento, Rickard; Lazic, Predrag

    2014-02-24

    Band structure engineering for specific electronic or optical properties is essential for the further development of many important technologies including thermoelectrics, optoelectronics, and microelectronics. In this work, we report orbital interaction as a powerful tool to finetune the band structure and the transport properties of charge carriers in bulk crystalline semiconductors. The proposed mechanism of orbital interaction on band structure is demonstrated for IV-VI thermoelectric semiconductors. For IV-VI materials, we find that the convergence of multiple carrier pockets not only displays a strong correlation with the s-p and spin-orbit coupling but also coincides with the enhancement of power factor. Our results suggest a useful path to engineer the band structure and an enticing solid-solution design principle to enhance thermoelectric performance.

  16. Analysis and design of sliding mode controller gains for boost power factor corrector.

    PubMed

    Kessal, Abdelhalim; Rahmani, Lazhar

    2013-09-01

    This paper presents a systematic procedure to compute the gains of sliding mode controller based on an optimization scheme. This controller is oriented to drive an AC-DC converter operating in continuous mode with power factor near unity, and in order to improve static and dynamic performances with large variations of reference voltage and load. This study shows the great influence of the controller gains on the global performances of the system. Hence, a methodology for choosing the gains is detailed. The sliding surface used in this study contains two state variables, input current and output voltage; the advantage of this surface is getting reactions against various disturbances-at the power source, the reference of the output, or the value of the load. The controller is experimentally confirmed for steady-state performance and transient response. PMID:23735439

  17. Analysis and design of sliding mode controller gains for boost power factor corrector.

    PubMed

    Kessal, Abdelhalim; Rahmani, Lazhar

    2013-09-01

    This paper presents a systematic procedure to compute the gains of sliding mode controller based on an optimization scheme. This controller is oriented to drive an AC-DC converter operating in continuous mode with power factor near unity, and in order to improve static and dynamic performances with large variations of reference voltage and load. This study shows the great influence of the controller gains on the global performances of the system. Hence, a methodology for choosing the gains is detailed. The sliding surface used in this study contains two state variables, input current and output voltage; the advantage of this surface is getting reactions against various disturbances-at the power source, the reference of the output, or the value of the load. The controller is experimentally confirmed for steady-state performance and transient response.

  18. Intra-alveolar tissue factor pathway inhibitor is not sufficient to block tissue factor procoagulant activity.

    PubMed

    Bastarache, Julie A; Wang, Ling; Wang, Zhengming; Albertine, Kurt H; Matthay, Michael A; Ware, Lorraine B

    2008-05-01

    The alveolar compartment in acute lung injury contains high levels of tissue factor (TF) procoagulant activity favoring fibrin deposition. We previously reported that the alveolar epithelium can release TF procoagulant activity in response to a proinflammatory stimulus. To test the hypothesis that the alveolar epithelium further modulates intra-alveolar fibrin deposition through secretion of an endogenous inhibitor to TF, tissue factor pathway inhibitor (TFPI), we measured TFPI levels in edema fluid (EF) from patients with acute respiratory distress syndrome. To determine whether the alveolar epithelium can release TFPI, both full-length TFPI and truncated TFPI were measured (ELISA) in pulmonary edema fluid from patients with acute respiratory distress syndrome (ARDS) and a control group of patients with hydrostatic pulmonary edema (HYDRO). TFPI protein was also measured in conditioned media (CM) and cell lysates (CL) from human alveolar epithelial cells (A549) after exposure to cytomix (TNF-alpha, IL-1 beta, IFN-gamma). TFPI protein levels were higher in pulmonary edema fluid from patients with ARDS vs. HYDRO. TFPI protein was increased in CM and did not change in CL after cytomix treatment; TFPI mRNA levels (RT-PCR) did not change. Despite the high levels of TFPI, both the EF and CM retained significant TF procoagulant activity as measured by plasma recalcification time. The majority of intra-alveolar TFPI was in a truncated, inactive form, whereas the majority of TFPI released from cells was full length, suggesting different mechanisms of inactivation. In summary, the alveolar epithelium releases TFPI in response to an inflammatory stimulus but does not increase TFPI gene transcription or protein production. Levels of intra-alveolar TFPI in ARDS are not sufficient to block intra-alveolar TF procoagulant activity due to truncation and inactivation of intra-alveolar TFPI. PMID:18310227

  19. Factors Affecting the Accuracy of Intraocular Lens Power Calculation with Lenstar

    PubMed Central

    Lee, Tae Hee; Sung, Mi Sun; Cui, Lian; Li, Ying

    2015-01-01

    This retrospective study was performed to compare refractive outcomes measured by conventional methods and by use of the Lenstar biometer and to investigate the factors affecting intraocular lens (IOL) power calculation with Lenstar with and without IOL-constant optimization. The study included 100 eyes of 86 patients who underwent cataract surgery. Corneal curvature was measured with a manual keratometer (MK), automated keratometer (AK), and the Lenstar biometer, and axial length (AL) was measured by A-scan and Lenstar. Mean numerical error (MNE) and mean absolute error (MAE) were compared between AK and MK with A-scan, and Lenstar with and without optimization. Factors affecting the accuracy of the IOL power calculation by use of Lenstar with and without optimization were analyzed. No significant differences were observed in the MNE or MAE among the devices. The proportion of MAE within 0.5 D was higher for Lenstar with optimization (62.7%) than without optimization (46.2%). The proportion of MAE within 0.5 D was 62% and 58% for MK and AK with A-scan, respectively. Without optimization, the MAE was smaller in eyes with ALs between 23 mm and 25 mm (p=0.03), whereas it was smaller at higher corneal powers when the IOL constant was optimized (>44 D, p=0.03). The IOL power calculations showed no significant differences among the devices, but the results of MAE within 0.5 D by use of Lenstar without optimization were worse than those of conventional methods. The AL influenced the accuracy of refractive outcomes determined by using Lenstar without optimization, and corneal curvature was shown to affect the accuracy of refractive measurements using Lenstar with optimization. PMID:26306304

  20. Accident-precipitating factors for crashes in turbine-powered general aviation aircraft.

    PubMed

    Boyd, Douglas D; Stolzer, Alan

    2016-01-01

    General aviation (14CFR Part 91) accounts for 83% of civil aviation fatalities. While much research has focused on accident causes/pilot demographics in this aviation sector, studies to identify factors leading up to the crash (accident-precipitating factors) are few. Such information could inform on pre-emptive remedial action. With this in mind and considering the paucity of research on turbine-powered aircraft accidents the study objectives were to identify accident-precipitating factors and determine if the accident rate has changed over time for such aircraft operating under 14CFR Part 91. The NTSB Access database was queried for accidents in airplanes (<12,501lb) powered by 1-2 turbine engines and occurring between 1989 and 2013. We developed and utilized an accident-precipitating factor taxonomy. Statistical analyses employed logistic regression, contingency tables and a generalized linear model with Poisson distribution. The "Checklist/Flight Manual Not Followed" was the most frequent accident-precipitating factor category and carried an excess risk (OR 2.34) for an accident with a fatal and/or serious occupant injury. This elevated risk reflected an over-representation of accidents with fatal and/or serious injury outcomes (p<0.001) in the "non-adherence to V Speeds" sub-category. For accidents grouped in the "Inadequate Pre-Flight Planning/Inspection/Procedure" the "inadequate weather planning" sub-category accounted (p=0.036) for the elevated risk (OR 2.22) of an accident involving fatal and/or serious injuries. The "Violation FARs/AIM Deviation" category was also associated with a greater risk for fatal and/or serious injury (OR 2.59) with "Descent below the MDA/failure to execute the missed approach" representing the largest sub-category. Accidents in multi-engine aircraft are more frequent than their single engine counterparts and the decline (50%) in the turbine aircraft accident rate over the study period was likely due, in part, to a 6-fold

  1. Accident-precipitating factors for crashes in turbine-powered general aviation aircraft.

    PubMed

    Boyd, Douglas D; Stolzer, Alan

    2016-01-01

    General aviation (14CFR Part 91) accounts for 83% of civil aviation fatalities. While much research has focused on accident causes/pilot demographics in this aviation sector, studies to identify factors leading up to the crash (accident-precipitating factors) are few. Such information could inform on pre-emptive remedial action. With this in mind and considering the paucity of research on turbine-powered aircraft accidents the study objectives were to identify accident-precipitating factors and determine if the accident rate has changed over time for such aircraft operating under 14CFR Part 91. The NTSB Access database was queried for accidents in airplanes (<12,501lb) powered by 1-2 turbine engines and occurring between 1989 and 2013. We developed and utilized an accident-precipitating factor taxonomy. Statistical analyses employed logistic regression, contingency tables and a generalized linear model with Poisson distribution. The "Checklist/Flight Manual Not Followed" was the most frequent accident-precipitating factor category and carried an excess risk (OR 2.34) for an accident with a fatal and/or serious occupant injury. This elevated risk reflected an over-representation of accidents with fatal and/or serious injury outcomes (p<0.001) in the "non-adherence to V Speeds" sub-category. For accidents grouped in the "Inadequate Pre-Flight Planning/Inspection/Procedure" the "inadequate weather planning" sub-category accounted (p=0.036) for the elevated risk (OR 2.22) of an accident involving fatal and/or serious injuries. The "Violation FARs/AIM Deviation" category was also associated with a greater risk for fatal and/or serious injury (OR 2.59) with "Descent below the MDA/failure to execute the missed approach" representing the largest sub-category. Accidents in multi-engine aircraft are more frequent than their single engine counterparts and the decline (50%) in the turbine aircraft accident rate over the study period was likely due, in part, to a 6-fold

  2. Improvement of force factor of magnetostrictive vibration power generator for high efficiency

    SciTech Connect

    Kita, Shota Ueno, Toshiyuki; Yamada, Sotoshi

    2015-05-07

    We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy of 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.

  3. Improvement of force factor of magnetostrictive vibration power generator for high efficiency

    NASA Astrophysics Data System (ADS)

    Kita, Shota; Ueno, Toshiyuki; Yamada, Sotoshi

    2015-05-01

    We develop high power magnetostrictive vibration power generator for battery-free wireless electronics. The generator is based on a cantilever of parallel beam structure consisting of coil-wound Galfenol and stainless plates with permanent magnet for bias. Oscillating force exerted on the tip bends the cantilever in vibration yields stress variation of Galfenol plate, which causes flux variation and generates voltage on coil due to the law of induction. This generator has advantages over conventional, such as piezoelectric or moving magnet types, in the point of high efficiency, highly robust, and low electrical impedance. Our concern is the improvement of energy conversion efficiency dependent on the dimension. Especially, force factor, the conversion ratio of the electromotive force (voltage) on the tip velocity in vibration, has an important role in energy conversion process. First, the theoretical value of the force factor is formulated and then the validity was verified by experiments, where we compare four types of prototype with parameters of the dimension using 7.0 × 1.5 × 50 mm beams of Galfenol with 1606-turn wound coil. In addition, the energy conversion efficiency of the prototypes depending on load resistance was measured. The most efficient prototype exhibits the maximum instantaneous power of 0.73 W and energy of 4.7 mJ at a free vibration of frequency of 202 Hz in the case of applied force is 25 N. Further, it was found that energy conversion efficiency depends not only on the force factor but also on the damping (mechanical loss) of the vibration.

  4. On the quasi-steady aerodynamics of normal hovering flight part I: the induced power factor

    PubMed Central

    Nabawy, Mostafa R. A.; Crowther, William J.

    2014-01-01

    An analytical treatment to quantify the losses captured in the induced power factor, k, is provided for flapping wings in normal hover, including the effects of non-uniform downwash, tip losses and finite flapping amplitude. The method is based on a novel combination of actuator disc and lifting line blade theories that also takes into account the effect of advance ratio. The model has been evaluated against experimental results from the literature and qualitative agreement obtained for the effect of advance ratio on the lift coefficient of revolving wings. Comparison with quantitative experimental data for the circulation as a function of span for a fruitfly wing shows that the model is able to correctly predict the circulation shape of variation, including both the magnitude of the peak circulation and the rate of decay in circulation towards zero. An evaluation of the contributions to induced power factor in normal hover for eight insects is provided. It is also shown how Reynolds number can be accounted for in the induced power factor, and good agreement is obtained between predicted span efficiency as a function of Reynolds number and numerical results from the literature. Lastly, it is shown that for a flapping wing in hover k owing to the non-uniform downwash effect can be reduced to 1.02 using an arcsech chord distribution. For morphologically realistic wing shapes based on beta distributions, it is shown that a value of 1.07 can be achieved for a radius of first moment of wing area at 40% of wing length. PMID:24522785

  5. On the quasi-steady aerodynamics of normal hovering flight part I: the induced power factor.

    PubMed

    Nabawy, Mostafa R A; Crowther, William J

    2014-04-01

    An analytical treatment to quantify the losses captured in the induced power factor, k, is provided for flapping wings in normal hover, including the effects of non-uniform downwash, tip losses and finite flapping amplitude. The method is based on a novel combination of actuator disc and lifting line blade theories that also takes into account the effect of advance ratio. The model has been evaluated against experimental results from the literature and qualitative agreement obtained for the effect of advance ratio on the lift coefficient of revolving wings. Comparison with quantitative experimental data for the circulation as a function of span for a fruitfly wing shows that the model is able to correctly predict the circulation shape of variation, including both the magnitude of the peak circulation and the rate of decay in circulation towards zero. An evaluation of the contributions to induced power factor in normal hover for eight insects is provided. It is also shown how Reynolds number can be accounted for in the induced power factor, and good agreement is obtained between predicted span efficiency as a function of Reynolds number and numerical results from the literature. Lastly, it is shown that for a flapping wing in hover k owing to the non-uniform downwash effect can be reduced to 1.02 using an arcsech chord distribution. For morphologically realistic wing shapes based on beta distributions, it is shown that a value of 1.07 can be achieved for a radius of first moment of wing area at 40% of wing length. PMID:24522785

  6. On the quasi-steady aerodynamics of normal hovering flight part I: the induced power factor.

    PubMed

    Nabawy, Mostafa R A; Crowther, William J

    2014-04-01

    An analytical treatment to quantify the losses captured in the induced power factor, k, is provided for flapping wings in normal hover, including the effects of non-uniform downwash, tip losses and finite flapping amplitude. The method is based on a novel combination of actuator disc and lifting line blade theories that also takes into account the effect of advance ratio. The model has been evaluated against experimental results from the literature and qualitative agreement obtained for the effect of advance ratio on the lift coefficient of revolving wings. Comparison with quantitative experimental data for the circulation as a function of span for a fruitfly wing shows that the model is able to correctly predict the circulation shape of variation, including both the magnitude of the peak circulation and the rate of decay in circulation towards zero. An evaluation of the contributions to induced power factor in normal hover for eight insects is provided. It is also shown how Reynolds number can be accounted for in the induced power factor, and good agreement is obtained between predicted span efficiency as a function of Reynolds number and numerical results from the literature. Lastly, it is shown that for a flapping wing in hover k owing to the non-uniform downwash effect can be reduced to 1.02 using an arcsech chord distribution. For morphologically realistic wing shapes based on beta distributions, it is shown that a value of 1.07 can be achieved for a radius of first moment of wing area at 40% of wing length.

  7. Cancer procoagulant: a factor X activator, tumor marker and growth factor from malignant tissue.

    PubMed

    Gordon, S G; Mielicki, W P

    1997-03-01

    Hemostatic abnormalities associated with malignant disease led to the search for and discovery of a proteolytic enzyme that activated factor X in the blood coagulation cascade. It was named cancer procoagulant (CP). CP is a cysteine proteinase that is found in malignant and fetal (human amnion-chorion) tissue; it has not been found in normally differentiated tissue. It is a calcium-dependent, Mn2+ stimulated enzyme that has enhanced activity and inhibition in a reduced environment. This review presents a complete compilation and discussion of the known chemical and enzymatic characteristics of CP as well as many purification and assay procedures. Several unique properties of these procedures are described. Some problems and controversies are highlighted in each of the sections. An immunoassay for CP as a tumor marker and some of its potential applications in the diagnosis and monitoring of cancer are reviewed. Some therapeutic implications of CP are noted in light of the observation that antibodies to CP block the metastatic seeding of lung colonies in vivo and diminish the viability of tumor cells in vitro. Finally, comments about the relationship between tissue factor and CP in the malignant cells are provided.

  8. Control of mechanically activated polymersome fusion: Factors affecting fusion

    SciTech Connect

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the size of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.

  9. Control of mechanically activated polymersome fusion: Factors affecting fusion

    DOE PAGES

    Henderson, Ian M.; Paxton, Walter F.

    2014-12-15

    Previously we have studied the mechanically-activated fusion of extruded (200 nm) polymer vesicles into giant polymersomes using agitation in the presence of salt. In this study we have investigated several factors contributing to this phenomenon, including the effects of (i) polymer vesicle concentration, (ii) agitation speed and duration, and iii) variation of the salt and its concentration. It was found that increasing the concentration of the polymer dramatically increases the production of giant vesicles through the increased collisions of polymersomes. Our investigations also found that increasing the frequency of agitation increased the efficiency of fusion, though ultimately limited the sizemore » of vesicle which could be produced due to the high shear involved. Finally it was determined that salt-mediation of the fusion process was not limited to NaCl, but is instead a general effect facilitated by the presence of solvated ionic compounds, albeit with different salts initiating fusion at different concentration.« less

  10. Phylogenomics of caspase-activated DNA fragmentation factor

    SciTech Connect

    Eckhart, Leopold . E-mail: leopold.eckhart@meduniwien.ac.at; Fischer, Heinz; Tschachler, Erwin

    2007-04-27

    The degradation of nuclear DNA by DNA fragmentation factor (DFF) is a key step in apoptosis of mammalian cells. Using comparative genomics, we have here determined the evolutionary history of the genes encoding the two DFF subunits, DFFA (also known as ICAD) and DFFB (CAD). Orthologs of DFFA and DFFB were identified in Nematostella vectensis, a representative of the primitive metazoan clade cnidarians, and in various vertebrates and insects, but not in representatives of urochordates, echinoderms, and nematodes. The domains mediating the interaction of DFFA and DFFB, a caspase cleavage site in DFFA, and the amino acid residues critical for endonuclease activity of DFFB were conserved in Nematostella. These findings suggest that DFF has been a part of the primordial apoptosis system of the eumetazoan common ancestor and that the ancient cell death machinery has degenerated in several evolutionary lineages, including the one leading to the prototypical apoptosis model, Caenorhabditis elegans.

  11. [Antifibrillatory activity of dipeptide antagonist of nerve growth factor].

    PubMed

    Kryzhanovskiĭ, S A; Stoliarchuk, V N; Vititnova, M B; Tsorin, I B; Pekel'dina, E S; Gudasheva, T A

    2012-01-01

    In experiments on anesthetized rats were assessed antifibrillatoty action of dipeptide GK-1. This compound is the fragment of fourth loop of nerve growth factor (NGF) and manifests antagonistic activity in respect to TrkA receptor, that specified for NGF. It is shown that this compound is able to significantly increase the threshold of electrical fibrillation of the heart and its effectiveness is not inferior to the reference antiarrhythmics I and III class on Vaughan Williams classification. However, unlike the latter, antifibrillatory action of dipeptide GK-1 was delayed and realized within 40-60 minutes after its administration. It is discussed possible mechanisms underlying antifibrillatory action of dipeptide GK-1, that, to some extent, may be associated with its ability to change the reactivity of beta-adrenergic structures of the heart.

  12. Human factors in remote control engineering development activities

    SciTech Connect

    Clarke, M.M.; Hamel, W.R.; Draper, J.V.

    1983-01-01

    Human factors engineering, which is an integral part of the advanced remote control development activities at the Oak Ridge National Laboratory, is described. First, work at the Remote Systems Development Facility (RSDF) has shown that operators can perform a wide variety of tasks, some of which were not specifically designed for remote systems, with a dextrous electronic force-reflecting servomanipulator and good television remote viewing capabilities. Second, the data collected during mock-up remote maintenance experiments at the RSDF have been analyzed to provide guidelines for the design of human interfaces with an integrated advanced remote maintenance system currently under development. Guidelines have been provided for task allocation between operators, remote viewing systems, and operator controls. 6 references, 5 figures, 2 tables.

  13. Lorentz factor distribution of blazars from the optical Fundamental Plane of black hole activity

    NASA Astrophysics Data System (ADS)

    Saikia, Payaswini; Körding, Elmar; Falcke, Heino

    2016-09-01

    Blazar radiation is dominated by a relativistic jet which can be modelled at first approximation using just two intrinsic parameters - the Lorentz factor Γ and the viewing angle θ. Blazar jet observations are often beamed due to relativistic effects, complicating the understanding of these intrinsic properties. The most common way to estimate blazar Lorentz factors needs the estimation of apparent jet speeds and Doppler beaming factors. We present a new and independent method of constructing the blazar Lorentz factor distribution, using the optical Fundamental Plane of black hole activity. The optical Fundamental Plane is a plane stretched out by both the supermassive black holes and the X-ray binaries, in the 3D space provided by their [O III] line luminosity, radio luminosity and black hole mass. We use the intrinsic radio luminosity obtained from the optical Fundamental Plane to constrain the boosting parameters of the VLBA Imaging and Polarimetry Survey blazar sample. We find a blazar bulk Lorentz factor distribution in the form of a power law as N(Γ) ∝ Γ-2.1 ± 0.4 for the Γ range of 1-40. We also discuss the viewing angle distribution of the blazars and the dependence of our results on the input parameters.

  14. Wind Power predictability a risk factor in the design, construction and operation of Wind Generation Turbines

    NASA Astrophysics Data System (ADS)

    Thiesen, J.; Gulstad, L.; Ristic, I.; Maric, T.

    2010-09-01

    Summit: The wind power predictability is often a forgotten decision and planning factor for most major wind parks, both onshore and offshore. The results of the predictability are presented after having examined a number of European offshore and offshore parks power predictability by using three(3) mesoscale model IRIE_GFS and IRIE_EC and WRF. Full description: It is well known that the potential wind production is changing with latitude and complexity in terrain, but how big are the changes in the predictability and the economic impacts on a project? The concept of meteorological predictability has hitherto to some degree been neglected as a risk factor in the design, construction and operation of wind power plants. Wind power plants are generally built in places where the wind resources are high, but these are often also sites where the predictability of the wind and other weather parameters is comparatively low. This presentation addresses the question of whether higher predictability can outweigh lower average wind speeds with regard to the overall economy of a wind power project. Low predictability also tends to reduce the value of the energy produced. If it is difficult to forecast the wind on a site, it will also be difficult to predict the power production. This, in turn, leads to increased balance costs and a less reduced carbon emission from the renewable source. By investigating the output from three(3) mesoscale models IRIE and WRF, using ECMWF and GFS as boundary data over a forecasting period of 3 months for 25 offshore and onshore wind parks in Europe, the predictability are mapped. Three operational mesoscale models with two different boundary data have been chosen in order to eliminate the uncertainty with one mesoscale model. All mesoscale models are running in a 10 km horizontal resolution. The model output are converted into "day a head" wind turbine generation forecasts by using a well proven advanced physical wind power model. The power models

  15. Electronic Origins of Large Thermoelectric Power Factor of LaOBiS2-xSex

    NASA Astrophysics Data System (ADS)

    Nishida, Atsuhiro; Nishiate, Hirotaka; Lee, Chul-Ho; Miura, Osuke; Mizuguchi, Yoshikazu

    2016-07-01

    We have examined the electrical transport properties of densified LaOBiS2-xSex, which constitutes a new family of thermoelectric materials. The power factor increases with increasing concentration of Se, i.e., Se substitution leads to an enhanced electrical conductivity, without suppression of the Seebeck coefficient. Hall measurements reveal that the carrier mobility increases with decreasing carrier concentration as Se doping, which is responsible for the low electrical resistivity and large absolute values of the Seebeck coefficient in the system.

  16. Improvement of Input Current Waveform for Soft-Switching Boost DCM Converter with Unity Power Factor

    NASA Astrophysics Data System (ADS)

    Taniguchi, Katsunori; Morizane, Toshimitsu; Kimura, Noriyuki

    In this paper, a soft-switching discontinuous mode (DCM) power factor corrected (PFC) converter is analyzed by applying the double Fourier series expansion. It is found that the fundamental component and higher-order harmonics included in the input current waveform are obtained by the Fourier series expansion of the mean value of the inductor current. From the theoretical analysis, a new method removing the distortion of the input current waveform is proposed. In spite of an open loop system, the proposed method makes a great improvement of the total harmonic distortion even if the ratio of output voltage to input voltage is very low.

  17. Fluid Shear Stress Increases Neutrophil Activation via Platelet-Activating Factor

    PubMed Central

    Mitchell, Michael J.; Lin, Kimberly S.; King, Michael R.

    2014-01-01

    Leukocyte exposure to hemodynamic shear forces is critical for physiological functions including initial adhesion to the endothelium, the formation of pseudopods, and migration into tissues. G-protein coupled receptors on neutrophils, which bind to chemoattractants and play a role in neutrophil chemotaxis, have been implicated as fluid shear stress sensors that control neutrophil activation. Recently, exposure to physiological fluid shear stresses observed in the microvasculature was shown to reduce neutrophil activation in the presence of the chemoattractant formyl-methionyl-leucyl-phenylalanine. Here, however, human neutrophil preexposure to uniform shear stress (0.1–2.75 dyn/cm2) in a cone-and-plate viscometer for 1–120 min was shown to increase, rather than decrease, neutrophil activation in the presence of platelet activating factor (PAF). Fluid shear stress exposure increased PAF-induced neutrophil activation in terms of L-selectin shedding, αMβ2 integrin activation, and morphological changes. Neutrophil activation via PAF was found to correlate with fluid shear stress exposure, as neutrophil activation increased in a shear stress magnitude- and time-dependent manner. These results indicate that fluid shear stress exposure increases neutrophil activation by PAF, and, taken together with previous observations, differentially controls how neutrophils respond to chemoattractants. PMID:24853753

  18. Policies and market factors driving wind power development in the United States

    SciTech Connect

    Bird, Lori; Parsons, Brian; Gagliano, Troy; Brown, Matthew; Wiser, Ryan; Bolinger, Mark

    2003-07-30

    In the United States, there has been substantial recent growth in wind energy generating capacity, with growth averaging 24 percent annually during the past five years. About 1,700 MW of wind energy capacity was installed in 2001, while another 410 MW became operational in 2002. This year (2003) shows promise of significant growth with more than 1,100 MW planned. With this growth, an increasing number of states are experiencing investment in wind energy projects. Wind installations currently exist in about half of all U.S. states. This paper explores the key factors at play in the states in which a substantial amount of wind energy capacity has been developed or planned. Some of the factors that are examined include policy drivers, such as renewable portfolio standards (RPS), federal and state financial incentives, and integrated resource planning; as well as market drivers, such as consumer demand for green power, natural gas price volatility, and wholesale market rules.

  19. Essential role of platelet activation via protease activated receptor 4 in tissue factor-initiated inflammation

    PubMed Central

    Busso, Nathalie; Chobaz-Péclat, Veronique; Hamilton, Justin; Spee, Pieter; Wagtmann, Nicolai; So, Alexander

    2008-01-01

    Introduction Tissue factor (TF) activation of the coagulation proteases enhances inflammation in animal models of arthritis and endotoxemia, but the mechanism of this effect is not yet fully understood – in particular, whether this is primarily due to fibrin formation or through activation of protease activated receptors (PARs). Methods We induced extravascular inflammation by injection of recombinant soluble murine TF (sTF1–219) in the hind paw. The effects of thrombin inhibition, fibrinogen and platelet depletion were evaluated, as well as the effects of PAR deficiency using knockout mice deficient for each of the PARs. Results Injection of soluble TF provoked a rapid onset of paw swelling. Inflammation was confirmed histologically and by increased serum IL-6 levels. Inflammation was significantly reduced by depletion of fibrinogen (P < 0.05) or platelets (P = 0.015), and by treatment with hirudin (P = 0.04) or an inhibitor of activated factor VII (P < 0.001) compared with controls. PAR-4-deficient mice exhibited significantly reduced paw swelling (P = 0.003). In contrast, a deficiency in either PAR-1, PAR-2 or PAR-3 did not affect the inflammatory response to soluble TF injection. Conclusion Our results show that soluble TF induces acute inflammation through a thrombin-dependent pathway and both fibrin deposition and platelet activation are essential steps in this process. The activation of PAR-4 on platelets is crucial and the other PARs do not play a major role in soluble TF-induced inflammation. PMID:18412955

  20. Activation loop 3 and the 170 loop interact in the active conformation of coagulation factor VIIa.

    PubMed

    Persson, Egon; Olsen, Ole H

    2009-06-01

    The initiation of blood coagulation involves tissue factor (TF)-induced allosteric activation of factor VIIa (FVIIa), which circulates in a zymogen-like state. In addition, the (most) active conformation of FVIIa presumably relies on a number of intramolecular interactions. We have characterized the role of Gly372(223) in FVIIa, which is the sole residue in activation loop 3 that is capable of forming backbone hydrogen bonds with the unusually long 170 loop and with activation loop 2, by studying the effects of replacement with Ala [G372(223)A]. G372A-FVIIa, both in the free and TF-bound form, exhibited reduced cleavage of factor X (FX) and of peptidyl substrates, and had increased K(m) values compared with wild-type FVIIa. Inhibition of G372A-FVIIa.sTF by p-aminobenzamidine was characterized by a seven-fold higher K(i) than obtained with FVIIa.sTF. Crystallographic and modelling data suggest that the most active conformation of FVIIa depends on the backbone hydrogen bond between Gly372(223) and Arg315(170C) in the 170 loop. Despite the reduced activity and inhibitor susceptibility, native and active site-inhibited G372A-FVIIa bound sTF with the same affinity as the corresponding forms of FVIIa, and burial of the N-terminus of the protease domain increased similarly upon sTF binding to G372A-FVIIa and FVIIa. Thus Gly372(223) in FVIIa appears to play a critical role in maturation of the S1 pocket and adjacent subsites, but does not appear to be of importance for TF binding and the ensuing allostery. PMID:19490111

  1. Power-gated 32 bit microprocessor with a power controller circuit activated by deep-sleep-mode instruction achieving ultra-low power operation

    NASA Astrophysics Data System (ADS)

    Koike, Hiroki; Ohsawa, Takashi; Miura, Sadahiko; Honjo, Hiroaki; Ikeda, Shoji; Hanyu, Takahiro; Ohno, Hideo; Endoh, Tetsuo

    2015-04-01

    A spintronic-based power-gated micro-processing unit (MPU) is proposed. It includes a power control circuit activated by the newly supported power-off instruction for the deep-sleep mode. These means enable the power-off procedure for the MPU to be executed appropriately. A test chip was designed and fabricated using 90 nm CMOS and an additional 100 nm MTJ process; it was successfully operated. The guideline of the energy reduction effects for this MPU was presented, using the estimation based on the measurement results of the test chip. The result shows that a large operation energy reduction of 1/28 can be achieved when the operation duty is 10%, under the condition of a sufficient number of idle clock cycles.

  2. Platelet activating factor produced in vitro by Kaposi's sarcoma cells induces and sustains in vivo angiogenesis.

    PubMed Central

    Bussolino, F; Arese, M; Montrucchio, G; Barra, L; Primo, L; Benelli, R; Sanavio, F; Aglietta, M; Ghigo, D; Rola-Pleszczynski, M R

    1995-01-01

    Imbalance in the network of soluble mediators may play a pivotal role in the pathogenesis of Kaposi's sarcoma (KS). In this study, we demonstrated that KS cells grown in vitro produced and in part released platelet activating factor (PAF), a powerful lipid mediator of inflammation and cell-to-cell communication. IL-1, TNF, and thrombin enhanced the synthesis of PAF. PAF receptor mRNA and specific, high affinity binding site for PAF were present in KS cells. Nanomolar concentration of PAF stimulated the chemotaxis and chemokinesis of KS cells, endothelial cells, and vascular smooth muscle cells. The migration response to PAF was inhibited by WEB 2170, a hetrazepinoic PAF receptor antagonist. Because neoangiogenesis is essential for the growth and progression of KS and since PAF can activate vascular endothelial cells, we examined the potential role of PAF as an instrumental mediator of angiogenesis associated with KS. Conditioned medium (CM) from KS cells (KS-CM) or KS cells themselves induced angiogenesis and macrophage recruitment in a murine model in which Matrigel was injected subcutaneously. These effects were inhibited by treating mice with WEB 2170. Synthetic PAF or natural PAF extracted from plasma of patients with classical KS also induced angiogenesis, which in turn was inhibited by WEB 2170. The action of PAF was amplified by expression of other angiogenic factors and chemokines: these included basic and acidic fibroblast growth factor, placental growth factor, vascular endothelial growth factor and its specific receptor flk-1, hepatocyte growth factor, KC, and macrophage inflammatory protein-2. Treatment with WEB 2170 abolished the expression of the transcripts of these molecules within Matrigel containing KS-CM. These results indicate that PAF may cooperate with other angiogenic molecules and chemokines in inducing vascular development in KS. Images PMID:7543496

  3. Radiation therapy generates platelet-activating factor agonists

    PubMed Central

    Sahu, Ravi P.; Harrison, Kathleen A.; Weyerbacher, Jonathan; Murphy, Robert C.; Konger, Raymond L.; Garrett, Joy Elizabeth; Chin-Sinex, Helen Jan; Johnston, Michael Edward; Dynlacht, Joseph R.; Mendonca, Marc; McMullen, Kevin; Li, Gengxin; Spandau, Dan F.; Travers, Jeffrey B.

    2016-01-01

    Pro-oxidative stressors can suppress host immunity due to their ability to generate oxidized lipid agonists of the platelet-activating factor-receptor (PAF-R). As radiation therapy also induces reactive oxygen species, the present studies were designed to define whether ionizing radiation could generate PAF-R agonists and if these lipids could subvert host immunity. We demonstrate that radiation exposure of multiple tumor cell lines in-vitro, tumors in-vivo, and human subjects undergoing radiation therapy for skin tumors all generate PAF-R agonists. Structural characterization of radiation-induced PAF-R agonistic activity revealed PAF and multiple oxidized glycerophosphocholines that are produced non-enzymatically. In a murine melanoma tumor model, irradiation of one tumor augmented the growth of the other (non-treated) tumor in a PAF-R-dependent process blocked by a cyclooxygenase-2 inhibitor. These results indicate a novel pathway by which PAF-R agonists produced as a byproduct of radiation therapy could result in tumor treatment failure, and offer important insights into potential therapeutic strategies that could improve the overall antitumor effectiveness of radiation therapy regimens. PMID:26959112

  4. Radiation therapy generates platelet-activating factor agonists.

    PubMed

    Sahu, Ravi P; Harrison, Kathleen A; Weyerbacher, Jonathan; Murphy, Robert C; Konger, Raymond L; Garrett, Joy Elizabeth; Chin-Sinex, Helen Jan; Johnston, Michael Edward; Dynlacht, Joseph R; Mendonca, Marc; McMullen, Kevin; Li, Gengxin; Spandau, Dan F; Travers, Jeffrey B

    2016-04-12

    Pro-oxidative stressors can suppress host immunity due to their ability to generate oxidized lipid agonists of the platelet-activating factor-receptor (PAF-R). As radiation therapy also induces reactive oxygen species, the present studies were designed to define whether ionizing radiation could generate PAF-R agonists and if these lipids could subvert host immunity. We demonstrate that radiation exposure of multiple tumor cell lines in-vitro, tumors in-vivo, and human subjects undergoing radiation therapy for skin tumors all generate PAF-R agonists. Structural characterization of radiation-induced PAF-R agonistic activity revealed PAF and multiple oxidized glycerophosphocholines that are produced non-enzymatically. In a murine melanoma tumor model, irradiation of one tumor augmented the growth of the other (non-treated) tumor in a PAF-R-dependent process blocked by a cyclooxygenase-2 inhibitor. These results indicate a novel pathway by which PAF-R agonists produced as a byproduct of radiation therapy could result in tumor treatment failure, and offer important insights into potential therapeutic strategies that could improve the overall antitumor effectiveness of radiation therapy regimens. PMID:26959112

  5. Single-frequency linearly polarized master-oscillator fiber power amplifier system and its application in high fill factor coherent beam combining.

    PubMed

    Qi, Yunfeng; Liu, Chi; Zhou, Jun; Lou, Qihong; Chen, Weibiao; Dong, Jingxing; Wei, Yunrong

    2009-10-10

    In this paper we combine the master-oscillator power fiber amplifier (MOPFA), active phase-compensation, and beam-tilting techniques to demonstrate high fill factor coherent beam combining. First, we optimize a single-frequency, linearly polarized MOPFA system with high scalability and flexibility based on compact, high efficiency Yb-doped fiber amplifier chains. Second, we demonstrate high fill factor coherent beam combining of these MOPFA arrays at a 50 W level in the far field successfully. Last, the interference matrix of eight element arrays under an opened loop condition is investigated. Scaling the system to higher power can be expected by increasing the power per fiber chain and adding the number of laser channels. PMID:19823235

  6. Complement factor B activation in patients with preeclampsia.

    PubMed

    Velickovic, Ivan; Dalloul, Mudar; Wong, Karen A; Bakare, Olufunke; Schweis, Franz; Garala, Maya; Alam, Amit; Medranda, Giorgio; Lekovic, Jovana; Shuaib, Waqas; Tedjasukmana, Andreas; Little, Perry; Hanono, Daniel; Wijetilaka, Ruvini; Weedon, Jeremy; Lin, Jun; Toledano, Roulhac d'Arby; Zhang, Ming

    2015-06-01

    Preeclampsia is a leading cause of maternal and fetal morbidity and mortality. Bb, the active fragment of complement factor B (fB), has been reported to be a predictor of preeclampsia. However, conflicting results have been found by some investigators. We hypothesized that the disagreement in findings may be due to the racial/ethnic differences among various study groups, and that fB activation is significant in women of an ethnic minority with preeclampsia. We investigated the maternal and fetal levels of Bb (the activated fB fragment) in pregnant women of an ethnic minority with or without preeclampsia. We enrolled 291 pregnant women (96% of an ethnic minority, including 78% African-American). Thirteen percent of these were diagnosed with preeclampsia. Maternal venous blood was collected from all participants together with fetal umbilical cord blood samples from 154 deliveries in the 291 women. The results were analyzed using the Mann-Whitney U test and multivariate analyses. Maternal Bb levels were significantly higher in the preeclamptic group than in the nonpreeclamptic group. Levels of Bb in fetal cord blood were similar in both groups. Subgroup analyses of African-American patients' results confirmed the study hypothesis that there would be a significant increase in Bb in the maternal blood of the preeclamptic group and no increase in Bb in the fetal cord blood of this group. These results suggest that a maternal immune response through complement fB might play a role in the development of preeclampsia, particularly in African-American patients.

  7. Operation of the power information center: Performance of secretariat functions and information exchange activities in the advanced power field of the interagency advanced power group

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Highlights of activities conducted during the reporting period to facilitate the exchange of technical information among scientists and engineers both within the federal government and within industry are cited. Interagency Advanced Power Group meetings and special efforts, project briefs, and organization development are considered.

  8. Prediction of Pathway Activation by Xenobiotic-Responsive Transcription Factors in the Mouse Liver

    EPA Science Inventory

    Many drugs and environmentally-relevant chemicals activate xenobioticresponsive transcription factors (TF). Identification of target genes of these factors would be useful in predicting pathway activation in in vitro chemical screening. Starting with a large compendium of Affymet...

  9. Factors Associated With the Use of Standardized Power Mobility Skills Assessments Among Assistive Technology Practitioners.

    PubMed

    Jenkins, Gavin R; Vogtle, Laura K; Yuen, Hon K

    2015-01-01

    This study investigated self-reported prevalence of and factors affecting clinicians' use of standardized assessments when evaluating clients for power mobility devices (PMDs), and explored assessments clinicians typically use when carrying out PMD evaluation. An e-mail survey was sent to assistive technology professionals listed in the Rehabilitation Engineering and Assistive Technology Society of North America directory. Three hundred fifty-four respondents, qualified to conduct formal power mobility skills assessments, completed the online survey. Of those, 122 (34.5%) respondents reported that they were aware of the presence of standardized performance-based power mobility skills assessments, but only 28 (7.9%) used these assessments in their practice. Multivariate analysis revealed that the odds of the respondents who use the standardized assessments were 18 times higher for those who were aware of the presence of these assessments than those who were not (adjusted odds ratio [OR] OR = 17.85, P < 0.0001). The odds of using the standardized assessment for respondents who did not identify themselves as occupational or physical therapists were five times higher than those who were therapists (adjusted OR = 0.20, P < 0.0001). This survey revealed that the assistive technology practitioners who recommend PMDs mainly use non-standardized mobility skills assessments.

  10. Enhanced power factor of higher manganese silicide via melt spin synthesis method

    SciTech Connect

    Shi, Xiaoya; Li, Qiang; Shi, Xun; Chen, Lidong; Li, Yulong; He, Ying

    2014-12-28

    We report on the thermoelectric properties of the higher manganese silicide MnSi{sub 1.75} synthesized by means of a one-step non-equilibrium method. The ultrahigh cooling rate generated from the melt-spin technique is found to be effective in reducing second phases, which are inevitable during the traditional solid state diffusion processes. Aside from being detrimental to thermoelectric properties, second phases skew the revealing of the intrinsic properties of this class of materials, for example, the optimal level of carrier concentration. With this melt-spin sample, we are able to formulate a simple model based on a single parabolic band that can well describe the carrier concentration dependence of the Seebeck coefficient and power factor of the data reported in the literature. An optimal carrier concentration around 5 × 10{sup 20 }cm{sup −3} at 300 K is predicted according to this model. The phase-pure melt-spin sample shows the largest power factor at high temperature, resulting in the highest zT value among the three samples in this paper.

  11. Influence of germanium nano-inclusions on the thermoelectric power factor of bulk bismuth telluride alloy

    SciTech Connect

    Satyala, Nikhil; Zamanipour, Zahra; Norouzzadeh, Payam; Krasinski, Jerzy S.; Vashaee, Daryoosh; Tahmasbi Rad, Armin; Tayebi, Lobat

    2014-05-28

    Nanocomposite thermoelectric compound of bismuth telluride (Bi{sub 2}Te{sub 3}) with 5 at. % germanium nano-inclusions was prepared via mechanically alloying and sintering techniques. The influence of Ge nano-inclusions and long duration annealing on the thermoelectric properties of nanostructured Bi{sub 2}Te{sub 3} were investigated. It was found that annealing has significant effect on the carrier concentration, Seebeck coefficient, and the power factor of the thermoelectric compound. The systematic heat treatment also reduced the density of donor type defects thereby decreasing the electron concentration. While the as-pressed nanocomposite materials showed n-type properties, it was observed that with the increase of annealing time, the nanocomposite gradually transformed to an abundantly hole-dominated (p-type) sample. The long duration annealing (∼500 h) resulted in a significantly enhanced electrical conductivity pertaining to the augmentation in the density and the structural properties of the sample. Therefore, a simultaneous enhancement in both electrical and Seebeck coefficient characteristics resulted in a remarkable increase in the thermoelectric power factor.

  12. Model calculating annual mean atmospheric dispersion factor for coastal site of nuclear power plant.

    PubMed

    Hu, E B; Chen, J Y; Yao, R T; Zhang, M S; Gao, Z R; Wang, S X; Jia, P R; Liao, Q L

    2001-07-01

    This paper describes an atmospheric dispersion field experiment performed on the coastal site of nuclear power plant in the east part of China during 1995 to 1996. The three-dimension joint frequency are obtained by hourly observation of wind and temperature on a 100 m high tower; the frequency of the "event day of land and sea breezes" are given by observation of surface wind and land and sea breezes; the diffusion parameters are got from measurements of turbulent and wind tunnel simulation test. A new model calculating the annual mean atmospheric dispersion factor for coastal site of nuclear power plant is developed and established. This model considers not only the effect from mixing release and mixed layer but also the effect from the internal boundary layer and variation of diffusion parameters due to the distance from coast. The comparison between results obtained by the new model and current model shows that the ratio of annual mean atmospheric dispersion factor gained by the new model and the current one is about 2.0.

  13. Enhanced power factor of higher manganese silicide via melt spin synthesis method

    DOE PAGES

    Shi, Xiaoya; Shi, Xun; Li, Yulong; He, Ying; Chen, Lidong; Li, Qiang

    2014-12-30

    We report on the thermoelectric properties of the Higher Manganese Silicide MnSi₁.₇₅ (HMS) synthesized by means of a one-step non-equilibrium method. The ultrahigh cooling rate generated from the melt-spin technique is found to be effective in reducing second phases, which are inevitable during the traditional solid state diffusion processes. Aside from being detrimental to thermoelectric properties, second phases skew the revealing of the intrinsic properties of this class of materials, for example the optimal level of carrier concentration. With this melt-spin sample, we are able to formulate a simple model based on a single parabolic band that can well describemore » the carrier concentration dependence of the Seebeck coefficient and power factor of the data reported in the literature. An optimal carrier concentration around 5x10²⁰ cm⁻³ at 300 K is predicted according to this model. The phase-pure melt-spin sample shows the largest power factor at high temperature, resulting in the highest zT value among the three samples in this paper; the maximum value is superior to those reported in the literatures.« less

  14. Enhanced power factor of higher manganese silicide via melt spin synthesis method

    SciTech Connect

    Shi, Xiaoya; Shi, Xun; Li, Yulong; He, Ying; Chen, Lidong; Li, Qiang

    2014-12-30

    We report on the thermoelectric properties of the Higher Manganese Silicide MnSi₁.₇₅ (HMS) synthesized by means of a one-step non-equilibrium method. The ultrahigh cooling rate generated from the melt-spin technique is found to be effective in reducing second phases, which are inevitable during the traditional solid state diffusion processes. Aside from being detrimental to thermoelectric properties, second phases skew the revealing of the intrinsic properties of this class of materials, for example the optimal level of carrier concentration. With this melt-spin sample, we are able to formulate a simple model based on a single parabolic band that can well describe the carrier concentration dependence of the Seebeck coefficient and power factor of the data reported in the literature. An optimal carrier concentration around 5x10²⁰ cm⁻³ at 300 K is predicted according to this model. The phase-pure melt-spin sample shows the largest power factor at high temperature, resulting in the highest zT value among the three samples in this paper; the maximum value is superior to those reported in the literatures.

  15. Fibrinogen blocks the autoactivation and thrombin-mediated activation of factor XI on dextran sulfate.

    PubMed Central

    Scott, C F; Colman, R W

    1992-01-01

    The intrinsic pathway of blood coagulation is activated when factor XIa, one of the three contact-system enzymes, is generated and then activates factor IX. Factor XI has been shown to be efficiently activated in vitro by surface-bound factor XIIa after factor XI is transported to the surface by its cofactor, high molecular weight kininogen (HK). However, individuals lacking any of the three contact-system proteins--namely, factor XII, prekallikrein, and HK--do not suffer from bleeding abnormalities. This mystery has led several investigators to search for an "alternate" activation pathway for factor XI. Recently, factor XI has been reported to be autoactivated on the soluble "surface" dextran sulfate, and thrombin was shown to accelerate the autoactivation. However, it was also reported that HK, the cofactor for factor XIIa-mediated activation of factor XI, actually diminishes the thrombin-catalyzed activation rate of factor XI. Nonetheless, it was suggested that thrombin was a more efficient activator than factor XIIa. In this report we investigated the effect of fibrinogen, the major coagulation protein in plasma, on the activation rate of factor XI. Fibrinogen, the preferred substrate for thrombin in plasma, virtually prevented autoactivation of factor XI as well as the thrombin-mediated activation of factor XI, while having no effect on factor XIIa-catalyzed activation. HK dramatically curtailed the autoactivation of factor XI in addition to the thrombin-mediated activation. These data indicate that factor XI would not be autoactivated in a plasma environment, and thrombin would, therefore, be unlikely to potentiate the activation. We believe that the "missing pathway" for factor XI activation remains an enigma that warrants further investigation. PMID:1454798

  16. Design of an integrated thermoelectric generator power converter for ultra-low power and low voltage body energy harvesters aimed at ExG active electrodes

    NASA Astrophysics Data System (ADS)

    Ataei, Milad; Robert, Christian; Boegli, Alexis; Farine, Pierre-André

    2015-10-01

    This paper describes a detailed design procedure for an efficient thermal body energy harvesting integrated power converter. The procedure is based on the examination of power loss and power transfer in a converter for a self-powered medical device. The efficiency limit for the system is derived and the converter is optimized for the worst case scenario. All optimum system parameters are calculated respecting the transducer constraints and the application form factor. Circuit blocks including pulse generators are implemented based on the system specifications and optimized converter working frequency. At this working condition, it has been demonstrated that the wide area capacitor of the voltage doubler, which provides high voltage switch gating, can be eliminated at the expense of wider switches. With this method, measurements show that 54% efficiency is achieved for just a 20 mV transducer output voltage and 30% of the chip area is saved. The entire electronic board can fit in one EEG or ECG electrode, and the electronic system can convert the electrode to an active electrode.

  17. Determination of factor X activator in the venom of the saw-scaled viper (Echis carinatus).

    PubMed

    Stocker, K; Fischer, H; Brogli, M

    1986-01-01

    Factor X activator in Echis carinatus venom was determined by incubating the zymogen 'factor X' with venom, interrupting the activation process by ethylenediaminetetraacetic acid and measuring the generated proteinase 'factor Xa' by means of a synthetic chromogenic substrate. A comparison of factor X- and prothrombin-activating potencies in E. carinatus venoms of five different geographic origins revealed no correlation between these two procoagulant activities. PMID:3715901

  18. Encoding of rat working memory by power of multi-channel local field potentials via sparse non-negative matrix factorization.

    PubMed

    Liu, Xu; Liu, Tiao-Tiao; Bai, Wen-Wen; Yi, Hu; Li, Shuang-Yan; Tian, Xin

    2013-06-01

    Working memory plays an important role in human cognition. This study investigated how working memory was encoded by the power of multi-channel local field potentials (LFPs) based on sparse nonnegative matrix factorization (SNMF). SNMF was used to extract features from LFPs recorded from the prefrontal cortex of four Sprague-Dawley rats during a memory task in a Y maze, with 10 trials for each rat. Then the power-increased LFP components were selected as working memory-related features and the other components were removed. After that, the inverse operation of SNMF was used to study the encoding of working memory in the time-frequency domain. We demonstrated that theta and gamma power increased significantly during the working memory task. The results suggested that postsynaptic activity was simulated well by the sparse activity model. The theta and gamma bands were meaningful for encoding working memory.

  19. Water Activity Limits the Hygroscopic Growth Factor of Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Rodriguez, L. I.; Cabrera, J. A.; Golden, D.; Tabazadeh, A.

    2007-12-01

    In this work we study the hygroscopic behavior of organic aerosols, which has important implications for Earth's climate. The hygroscopic growth factor (HGF) is defined as the ratio of the diameter of a spherical particle when it is exposed to dry conditions to that at humid conditions. We present a new formulation to express the HGF of an aerosol particle as a function of water activity (aw) in the aqueous phase. This new formulation matches reported HGFs for common inorganic salts and water-miscible organic particles that are known to deliquesce into aqueous drops at high relative humidities (RH). Many studies use tandem differential mobility analyzers (TDMA) to determine the HGF of organic aerosols. For example, Brooks et al. used a TDMA to measure a HGF of 1.2 for 2 μm phthalic acid (PA) particles at 90% RH (aw= 0.9). However, water activity limits the growth of a particle that can be attributed to water uptake. We have assembled a vapor pressure apparatus to measure aw of aqueous solutions at room temperature. Measured water activities for PA, used in our growth formulation, yield a HGF of ~ 1.0005 for 2 μm PA particles at 90% RH. Comparing our results against Brooks et al. suggests that TDMA experiments may grossly overestimate the HGF of PA particles since water activity limits this growth to below 1.0005. Alternatively, we suggest that the adsorption of a negligible mass of water by a highly porous PA particle can lead to an apparent growth in particle size by changing its morphology. Other studies also use TDMAs to measure HGFs of secondary organic aerosols (SOAs). HGFs reported for SOAs are very similar to PA, suggesting that the observed growth may be due to morphological changes in particle size rather than water uptake as commonly assumed. We built a smog chamber where an organic precursor, such as d-limonene, reacts with nitrogen oxides under UV radiation to produce SOAs. We compare the HGFs for SOAs obtained with our method to those obtained with

  20. Contact system dependent fibrinolytic activity in vivo: observations in healthy subjects and factor XII deficient patients.

    PubMed

    Levi, M; Hack, C E; de Boer, J P; Brandjes, D P; Büller, H R; ten Cate, J W

    1992-01-01

    The contribution of activation of the contact system to activation of the fibrinolytic system in vivo was investigated in healthy volunteers and in factor XII deficient patients. The plasminogen activating activity in normal plasma was only partially blocked (for 77%) with specific antibodies to tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA). The residual activity could be quenched by a monoclonal antibody that inhibits factor XII activity and was not present in patients with a factor XII deficiency. The formation of plasmin upon the DDAVP stimulus as reflected by circulating plasmin-alpha 2-antiplasmin (PAP) complexes was lower in factor XII deficient patients than in healthy volunteers. These results indicate that in vivo the plasminogen activating activity is partially dependent on activation of the contact system. This fibrinolytic activity is impaired in factor XII deficient patients which may explain the occurrence of thromboembolic complications in these patients.

  1. Tumor necrosis factor alpha-induced angiogenesis depends on in situ platelet-activating factor biosynthesis

    PubMed Central

    1994-01-01

    Tumor necrosis factor (TNF) alpha, a potent inhibitor of endothelial cell growth in vitro, is angiogenic in vivo. Therefore, it was suggested that the angiogenic properties of this agent might be consequent to the production of secondary mediators. Since TNF-alpha stimulates the synthesis of platelet-activating factor (PAF) by monocytes and endothelial cells, we investigated the possible involvement of PAF in the angiogenic effect of TNF-alpha. Angiogenesis was studied in a murine model in which Matrigel was used as a vehicle for the delivery of mediators. In this model the angiogenesis induced by TNF-alpha was shown to be inhibited by WEB 2170, a specific PAF receptor antagonist. Moreover, in mice injected with TNF-alpha, PAF was detected within the Matrigel, 6 and 24 h after TNF-alpha injection. The synthesis of PAF within the Matrigel was concomitant with the early migration of endothelial cells and infiltration of monocytes. No infiltration of lymphocytes or polymorphonuclear leukocytes was observed. Synthetic PAF as well as PAF extracted and purified from mice challenged with TNF-alpha induced a rapid angiogenic response, inhibited by WEB 2170. These results suggest that the angiogenic effect of TNF-alpha is, at least in part, mediated by PAF synthesized from monocytes and/or endothelial cells infiltrating the Matrigel plug. PMID:7516414

  2. Myeloid leukemia factor is a conserved regulator of RUNX transcription factor activity involved in hematopoiesis.

    PubMed

    Bras, Stéphanie; Martin-Lannerée, Séverine; Gobert, Vanessa; Augé, Benoît; Breig, Osman; Sanial, Matthieu; Yamaguchi, Masamitsu; Haenlin, Marc; Plessis, Anne; Waltzer, Lucas

    2012-03-27

    Defining the function of the genes that, like RUNX1, are deregulated in blood cell malignancies represents an important challenge. Myeloid leukemia factors (MLFs) constitute a poorly characterized family of conserved proteins whose founding member, MLF1, has been associated with acute myeloid leukemia in humans. To gain insight into the functions of this family, we investigated the role of the Drosophila MLF homolog during blood cell development. Here we report that mlf controls the homeostasis of the Drosophila hematopoietic system. Notably, mlf participates in a positive feedback loop to fine tune the activity of the RUNX transcription factor Lozenge (LZ) during development of the crystal cells, one of the two main blood cell lineages in Drosophila. At the molecular level, our data in cell cultures and in vivo strongly suggest that MLF controls the number of crystal cells by protecting LZ from degradation. Remarkably, it appears that the human MLF1 protein can substitute for MLF in the crystal cell lineage. In addition, MLF stabilizes the human oncogenic fusion protein RUNX1-ETO and is required for RUNX1-ETO-induced blood cell disorders in a Drosophila model of leukemia. Finally, using the human leukemic blood cell line Kasumi-1, we show that MLF1 depletion impairs RUNX1-ETO accumulation and reduces RUNX1-ETO-dependent proliferation. Thus, we propose that the regulation of RUNX protein levels is a conserved feature of MLF family members that could be critical for normal and pathological blood cell development. PMID:22411814

  3. Pedaling power and speed production vs. technical factors and track difficulty in bicycle motocross cycling.

    PubMed

    Mateo, Manuel; Blasco-Lafarga, Cristina; Zabala, Mikel

    2011-12-01

    Mateo, M, Blasco-Lafarga, C, and Zabala, M. Pedaling power and speed production vs. technical factors and track difficulty in BMX cycling. J Strength Cond Res 25(12): 3248-3256, 2011-This article analyzes whether there is a determined profile in the production of cyclic and acyclic periods in relation to the phases of a bicycle motocross (BMX) race and whether this profile is related to the variables, Difficulty of track and Techniques used. After an initial test for determining maximum pedaling power (Pmax), 9 athletes belonging to the Spanish national team completed 3 series of 3 different types of races: (a) Complete track without pedaling; (b) Track, pedaling only at the gate start; and (c) track with free pedaling. The triple test was carried out over 3 days and on different level tracks: (a) high difficulty (HD), (b) medium difficulty (MD), and (c) low difficulty (LD). Our results show that average peak power applied in the BMX race was 85.21 ± 2.15% Pmax, coming down to 73.02 ± 18.38% at the gate start and to 51.37 ± 15.84% on the first straight. On the other hand, mean power (MP) in the BMX race is 33.79 ± 8.60% MPmax, with statistically significant differences in relation to the difficulty of the track (p < 0.000; 0.009; higher in the easiest). The mean velocity developed is 34.21 ± 1.0 km·h with significant differences (p < 0.000) in relation to the difficulty of the track. Acyclic efforts accounted for 86.3%, and cyclic efforts accounted for the remaining 16.7% of the overall performance in the race, with differences in relation to the difficulty of the track (p ≤ 0.003). Both power profile and performance (measured as velocity) are dependent on the phases and techniques of the race and are significantly affected by the level of difficulty of the track. The greater the technical level of the track, the lesser the possibility of developing cyclic power and vice versa. PMID:21804428

  4. Pedaling power and speed production vs. technical factors and track difficulty in bicycle motocross cycling.

    PubMed

    Mateo, Manuel; Blasco-Lafarga, Cristina; Zabala, Mikel

    2011-12-01

    Mateo, M, Blasco-Lafarga, C, and Zabala, M. Pedaling power and speed production vs. technical factors and track difficulty in BMX cycling. J Strength Cond Res 25(12): 3248-3256, 2011-This article analyzes whether there is a determined profile in the production of cyclic and acyclic periods in relation to the phases of a bicycle motocross (BMX) race and whether this profile is related to the variables, Difficulty of track and Techniques used. After an initial test for determining maximum pedaling power (Pmax), 9 athletes belonging to the Spanish national team completed 3 series of 3 different types of races: (a) Complete track without pedaling; (b) Track, pedaling only at the gate start; and (c) track with free pedaling. The triple test was carried out over 3 days and on different level tracks: (a) high difficulty (HD), (b) medium difficulty (MD), and (c) low difficulty (LD). Our results show that average peak power applied in the BMX race was 85.21 ± 2.15% Pmax, coming down to 73.02 ± 18.38% at the gate start and to 51.37 ± 15.84% on the first straight. On the other hand, mean power (MP) in the BMX race is 33.79 ± 8.60% MPmax, with statistically significant differences in relation to the difficulty of the track (p < 0.000; 0.009; higher in the easiest). The mean velocity developed is 34.21 ± 1.0 km·h with significant differences (p < 0.000) in relation to the difficulty of the track. Acyclic efforts accounted for 86.3%, and cyclic efforts accounted for the remaining 16.7% of the overall performance in the race, with differences in relation to the difficulty of the track (p ≤ 0.003). Both power profile and performance (measured as velocity) are dependent on the phases and techniques of the race and are significantly affected by the level of difficulty of the track. The greater the technical level of the track, the lesser the possibility of developing cyclic power and vice versa.

  5. Activation of p38 Mitogen-Activated Protein Kinase Promotes Epidermal Growth Factor Receptor Internalization

    PubMed Central

    Vergarajauregui, Silvia; Miguel, Anitza San; Puertollano, Rosa

    2006-01-01

    Endocytic trafficking plays an important role in the regulation of the epidermal growth factor receptor (EGFR). To address if cellular kinases regulate EGFR internalization, we used anisomycin, a potent activator of kinase cascades in mammalian cells, especially the stress-activated mitogen-activated protein (MAP) kinase subtypes. Here, we report that activation of p38 MAP kinase by anisomycin is sufficient to induce internalization of EGFR. Anisomycin and EGF employ different mechanisms to promote EGFR endocytosis as anisomycin-induced internalization does not require tyrosine kinase activity or ubiquitination of the receptor. In addition, anisomycin treatment did not result in delivery and degradation of EGFR at lysosomes. Incubation with a specific inhibitor of p38, or depletion of endogenous p38 by small interfering RNAs, abolished anisomycin-induced internalization of EGFR while having no effect on transferrin endocytosis, indicating that the effect of p38 activation on EGFR endocytosis is specific. Interestingly, inhibition of p38 activation also abolished endocytosis of EGFR induced by UV radiation. Our results reveal a novel role for p38 in the regulation of EGFR endocytosis and suggest that stimulation of EGFR internalization by p38 might represent a general mechanism to prevent generation of proliferative or anti-apoptotic signals under stress conditions. PMID:16683917

  6. Smart Moves: Powering up the Brain with Physical Activity

    ERIC Educational Resources Information Center

    Conyers, Marcus; Wilson, Donna

    2015-01-01

    The Common Core State Standards emphasize higher-order thinking, problem solving, and the creation, retention, and application of knowledge. Achieving these standards creates greater cognitive demands on students. Recent research suggests that active play and regular exercise have a positive effect on brain regions associated with executive…

  7. "Power, Regulation and Physically Active Identities": The Experiences of Rural and Regional Living Adolescent Girls

    ERIC Educational Resources Information Center

    Casey, M.; Mooney, A.; Smyth, J.; Payne, W.

    2016-01-01

    Drawing on interpretations of Foucault's techniques of power, we explored the discourses and power relations operative between groups of girls that appeared to influence their participation in Physical Education (PE) and outside of school in sport and physical activity (PA) in rural and regional communities. Interviews and focus groups were…

  8. Molecular imaging of nuclear factor-Y transcriptional activity maps proliferation sites in live animals

    PubMed Central

    Goeman, Frauke; Manni, Isabella; Artuso, Simona; Ramachandran, Balaji; Toietta, Gabriele; Bossi, Gianluca; Rando, Gianpaolo; Cencioni, Chiara; Germoni, Sabrina; Straino, Stefania; Capogrossi, Maurizio C.; Bacchetti, Silvia; Maggi, Adriana; Sacchi, Ada; Ciana, Paolo; Piaggio, Giulia

    2012-01-01

    In vivo imaging involving the use of genetically engineered animals is an innovative powerful tool for the noninvasive assessment of the molecular and cellular events that are often targets of therapy. On the basis of the knowledge that the activity of the nuclear factor-Y (NF-Y) transcription factor is restricted in vitro to proliferating cells, we have generated a transgenic reporter mouse, called MITO-Luc (for mitosis-luciferase), in which an NF-Y–dependent promoter controls luciferase expression. In these mice, bioluminescence imaging of NF-Y activity visualizes areas of physiological cell proliferation and regeneration during response to injury. Using this tool, we highlight for the first time a role of NF-Y activity on hepatocyte proliferation during liver regeneration. MITO-Luc reporter mice should facilitate investigations into the involvement of genes in cell proliferation and provide a useful model for studying aberrant proliferation in disease pathogenesis. They should be also useful in the development of new anti/proproliferative drugs and assessment of their efficacy and side effects on nontarget tissues. PMID:22379106

  9. Molecular imaging of nuclear factor-Y transcriptional activity maps proliferation sites in live animals.

    PubMed

    Goeman, Frauke; Manni, Isabella; Artuso, Simona; Ramachandran, Balaji; Toietta, Gabriele; Bossi, Gianluca; Rando, Gianpaolo; Cencioni, Chiara; Germoni, Sabrina; Straino, Stefania; Capogrossi, Maurizio C; Bacchetti, Silvia; Maggi, Adriana; Sacchi, Ada; Ciana, Paolo; Piaggio, Giulia

    2012-04-01

    In vivo imaging involving the use of genetically engineered animals is an innovative powerful tool for the noninvasive assessment of the molecular and cellular events that are often targets of therapy. On the basis of the knowledge that the activity of the nuclear factor-Y (NF-Y) transcription factor is restricted in vitro to proliferating cells, we have generated a transgenic reporter mouse, called MITO-Luc (for mitosis-luciferase), in which an NF-Y-dependent promoter controls luciferase expression. In these mice, bioluminescence imaging of NF-Y activity visualizes areas of physiological cell proliferation and regeneration during response to injury. Using this tool, we highlight for the first time a role of NF-Y activity on hepatocyte proliferation during liver regeneration. MITO-Luc reporter mice should facilitate investigations into the involvement of genes in cell proliferation and provide a useful model for studying aberrant proliferation in disease pathogenesis. They should be also useful in the development of new anti/proproliferative drugs and assessment of their efficacy and side effects on nontarget tissues. PMID:22379106

  10. Harmonic-resonator-based triboelectric nanogenerator as a sustainable power source and a self-powered active vibration sensor.

    PubMed

    Chen, Jun; Zhu, Guang; Yang, Weiqing; Jing, Qingshen; Bai, Peng; Yang, Ya; Hou, Te-Chien; Wang, Zhong Lin

    2013-11-13

    A harmonic-resonator-based triboelectric nanogenerator (TENG) is presented as a sustainable power source and an active vibration sensor. It can effectively respond to vibration frequencies ranging from 2 to 200 Hz with a considerably wide working bandwidth of 13.4 Hz. This work not only presents a new principle in the field of vibration energy harvesting but also greatly expands the applicability of TENGs.

  11. Is physical activity, practiced as recommended for health benefit, a risk factor for osteoarthritis?

    PubMed

    Lefèvre-Colau, Marie-Martine; Nguyen, Christelle; Haddad, Rebecca; Delamarche, Paul; Paris, Guillaume; Palazzo, Clémence; Poiraudeau, Serge; Rannou, François; Roren, Alexandra

    2016-06-01

    In this critical narrative review, we examine the role of physical activity (PA), recreational and elite sports in the development of knee/hip osteoarthritis (OA), taking into account the role of injury in this relationship. The process of article selection was unsystematic. Articles were selected on the basis of the authors' expertise, self-knowledge, and reflective practice. In the general adult population, self-reported diagnosis of knee/hip OA was not associated with low, moderate or high levels of PA. For studies using radiographic knee/hip OA as a primary outcome, the incidence of asymptomatic radiographic OA was higher for subjects with the highest quartile of usual PA than the least active subjects. The risk of incident radiographic knee/hip OA features was increased for subjects with a history of regular sports participation (for osteophyte formation but not joint space narrowing). This risk depended on the type of sport (team and power sports but not endurance and running), and certain conditions (high level of practice) were closely related to the risk of injury. The prevalence of radiographic OA was significantly higher, especially the presence of osteophytes, in former elite athletes than controls. The risk of OA was higher with participation in mixed sports, especially soccer or power sports, than endurance sport. However, the prevalence of clinical OA between former elite athletes and controls was similar, with less hip/knee disability in former athletes. Moderate daily recreational or sport activities, whatever the type of sport, are not a consistent risk factor for clinical or radiographic knee/hip OA. Risk of injury in different sports may be the key factor to understanding the risk of OA related to sport. PMID:27103057

  12. Observation of power gain in an inductive pulsed power system with an optically activated semiconductor closing and opening switch

    NASA Astrophysics Data System (ADS)

    Kung, Chun C.; Funk, Eric E.; Chauchard, Eve A.; Rhee, M. J.; Lee, Chi H.; Yan, Li

    1991-03-01

    Peak power gain greater than 15 was obtained with a current charged transmission line and an optically activated semiconductor opening switch. The optical pulse used for activating the switch is generated by a Nd:glass laser emitting at 1. 054 pm. It has a slow rise-time (''--''2OO uS) and a fast fall-time (s1O uS). In the experiment a 2 kV output voltage pulse was achieved with a 5 mm cube GaAs p-i-n diode sitch at 500 V charging voltage.

  13. Recombinant activated factor VII in post partum haemorrhage

    PubMed Central

    Magon, Navneet; Babu, K. M.; Kapur, Krishan; Chopra, Sanjiv; Joneja, Gurdarshan Singh

    2013-01-01

    Post-partum haemorrhage (PPH) is a life-threatening obstetric complication and the leading cause of maternal death. Any bleeding that results in or could result in haemodynamic instability, if untreated, must be considered as PPH. There is no controversy about the need for prevention and treatment of PPH. The keystone of management of PPH entails first, non-invasive and nonsurgical methods and then invasive and surgical methods. However, mortality remains high. Therefore, new advancements in the treatment are most crucial. One such advancement has been the use of recombinant activated factor VII (rFVIIa) in PPH. First used 12 years back in PPH, this universal haemostatic agent has been effectively used in controlling PPH. The best available indicator of rFVIIa efficacy is the arrest of haemorrhage, which is judged by visual evidence and haemodynamic stabilization. It also reduces costs of therapy and the use of blood components in massive PPH. In cases of intractable PPH with no other obvious indications for hysterectomy, administration of rFVIIa should be considered before surgery. We share our experience in a series of cases of PPH, successfully managed using rFVIIa. PMID:24403703

  14. Activated Factor X Induces Endothelial Cell Senescence Through IGFBP-5

    PubMed Central

    Sanada, Fumihiro; Taniyama, Yoshiaki; Muratsu, Jun; Otsu, Rei; Iwabayashi, Masaaki; Carracedo, Miguel; Rakugi, Hiromi; Morishita, Ryuichi

    2016-01-01

    Uncontrolled coagulation contributes to the pathophysiology of several chronic inflammatory diseases. In these conditions, senescent cells are often observed and is involved in the generation of inflammation. The coincidence of hyper-coagulation, cell senescence, and inflammation suggests the existence of a common underlying mechanism. Recent evidence indicates that activated coagulation factor X (FXa) plays a role in the processes beyond blood coagulation. This non-hematologic function entails the mediation of inflammation and tissue remodeling. We therefore tested the hypothesis that FXa induces cell senescence resulting in tissue inflammation and impaired tissue regeneration. Human umbilical vein endothelial cells were stimulated with FXa for 14 days. The proliferation of cells treated with FXa was significantly smaller, and the fraction of senescence-associated β-galactosidase-positive cells was increased as compared to the control group. RT-qPCR array revealed that FXa increased the expression of IGFBP-5, EGR-1, p53, and p16INK4a. Inhibition of FXa by a direct FXa inhibitor, rivaroxaban, or IGFBP-5 by siRNA decreased FXa-induced cell senescence, restoring cell proliferation. Moreover, in an ischemic hind limb mouse model, FXa inhibited neovascularization by endothelial progenitor cell. However, rivaroxaban significantly restored FXa-induced impaired angiogenesis. In summary, FXa induced endothelial cell senescence through IGFBP-5, resulting in impaired angiogenesis. PMID:27752126

  15. Platelet-activating factor-induced increases in glucose kinetics

    SciTech Connect

    Lang, C.H.; Dobrescu, C.; Hargrove, D.M.; Bagby, G.J.; Spitzer, J.J. )

    1988-02-01

    Platelet-activating factor (PAF) is a postulated mediator of many of the early hemodynamic effects of endotoxin. The aim of the present study was to determine whether in vivo administration of PAF could produce alterations in whole-body glucose metabolism that would mimic those seen during endotoxemia. Glucose kinetics were assessed in chronically catheterized conscious rats by the constant infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose before and for 4 h after either a bolus injection or a constant infusion of PAF. The bolus injection of PAF elevated the rate of glucose appearance (R{sub a}; 44%) for 1.5 h. The lower PAF infusion rate decreased blood pressure 11% to 104 mmHg, whereas the higher infusion rate decreased pressure 34% to 77 mmHg. Both PAF infusion rates produced elevations in plasma glucose and glucose R{sub a} throughout the 4-h infusion period in a dose-related manner. The PAF infusions also induced dose-related increases in plasma glucagon and catecholamine levels throughout the infusion period. Because the constant infusion of PAF did stimulate many of the hemodynamic and metabolic alterations produced by endotoxin, this study provides additional support for the potential importance of PAF as a mediator of the early hemodynamic and metabolic sequela of endotoxin shock. Furthermore, the PAF-induced changes in glucose metabolism appear to be mediated by the resultant elevation in plasma catecholamines.

  16. Activating Transcription Factor 3 Regulates Immune and Metabolic Homeostasis

    PubMed Central

    Rynes, Jan; Donohoe, Colin D.; Frommolt, Peter; Brodesser, Susanne; Jindra, Marek

    2012-01-01

    Integration of metabolic and immune responses during animal development ensures energy balance, permitting both growth and defense. Disturbed homeostasis causes organ failure, growth retardation, and metabolic disorders. Here, we show that the Drosophila melanogaster activating transcription factor 3 (Atf3) safeguards metabolic and immune system homeostasis. Loss of Atf3 results in chronic inflammation and starvation responses mounted primarily by the larval gut epithelium, while the fat body suffers lipid overload, causing energy imbalance and death. Hyperactive proinflammatory and stress signaling through NF-κB/Relish, Jun N-terminal kinase, and FOXO in atf3 mutants deregulates genes important for immune defense, digestion, and lipid metabolism. Reducing the dose of either FOXO or Relish normalizes both lipid metabolism and gene expression in atf3 mutants. The function of Atf3 is conserved, as human ATF3 averts some of the Drosophila mutant phenotypes, improving their survival. The single Drosophila Atf3 may incorporate the diversified roles of two related mammalian proteins. PMID:22851689

  17. Monte Carlo modeling provides accurate calibration factors for radionuclide activity meters.

    PubMed

    Zagni, F; Cicoria, G; Lucconi, G; Infantino, A; Lodi, F; Marengo, M

    2014-12-01

    Accurate determination of calibration factors for radionuclide activity meters is crucial for quantitative studies and in the optimization step of radiation protection, as these detectors are widespread in radiopharmacy and nuclear medicine facilities. In this work we developed the Monte Carlo model of a widely used activity meter, using the Geant4 simulation toolkit. More precisely the "PENELOPE" EM physics models were employed. The model was validated by means of several certified sources, traceable to primary activity standards, and other sources locally standardized with spectrometry measurements, plus other experimental tests. Great care was taken in order to accurately reproduce the geometrical details of the gas chamber and the activity sources, each of which is different in shape and enclosed in a unique container. Both relative calibration factors and ionization current obtained with simulations were compared against experimental measurements; further tests were carried out, such as the comparison of the relative response of the chamber for a source placed at different positions. The results showed a satisfactory level of accuracy in the energy range of interest, with the discrepancies lower than 4% for all the tested parameters. This shows that an accurate Monte Carlo modeling of this type of detector is feasible using the low-energy physics models embedded in Geant4. The obtained Monte Carlo model establishes a powerful tool for first instance determination of new calibration factors for non-standard radionuclides, for custom containers, when a reference source is not available. Moreover, the model provides an experimental setup for further research and optimization with regards to materials and geometrical details of the measuring setup, such as the ionization chamber itself or the containers configuration.

  18. Influence of Environmental Factors on Feammox Activity in Soil Environments

    NASA Astrophysics Data System (ADS)

    Huang, S.; Jaffe, P. R.

    2015-12-01

    The oxidation of ammonium (NH4+) under iron reducing conditions, referred to as Feammox, has been described in recent years by several investigators. The environmental characteristics in which the Feammox process occurs need to be understood in order to determine its contribution to the nitrogen cycle. In this study, a total of 66 locations were selected covering 4 different types of soils/sediments: wetland soils (W), river sediments (R), forest soils (F), and paddy soils (P) from several locations in central New Jersey, at Tims Branch at Savannah River in South Carolina, both in the Unities States, and at several locations in the Guangdong province in China. Though soil chemical analyses, serial culturing experiments, analysis of microbial communities, and using a canonical correspondence analysis, the occurrence of the Feammox reaction and the presence of Acidimicrobiaceae bacterium A6, which plays a key role in the Feammox process(1), were found in 17 samples. Analyses showed that the soil pH, as well as its Fe(III) and NH4+ content were the most important factors controlling the distribution of these Feammox microorganisms. Based on the results, soils in the subtropical forests and soils that are near agricultural areas could be Feammox hotspot. Under the conditions that favor the presence and activity of Feammox microorganisms and their oxidation of NH4+, denitrification bacteria were also active. However, the presence of nitrous oxide (N2O) reducers was limited under these conditions, implying that at locations where the Feammox process is active, conditions are favoring a higher ratio of N2O: N2 as the nitrogen (N) end products. Incubations of soils where the presence of Acidimicrobiaceae bacterium A6 was detected, were conducted for 120 days under two different DO levels (DO < 0.02 mg/L and DO = 0.8~1.0 mg/L) showing comparable amounts of NH4+ oxidation. In the incubations with DO < 0.02 mg/L, the proportion of Acidimicrobiaceae bacteria increased and

  19. Radio-frequency spectroscopy of the active fiber heating under condition of high-power lasing generation.

    PubMed

    Ryabushkin, O A; Shaidullin, R I; Zaytsev, I A

    2015-05-01

    A novel method for the precise temperature measurement of active fibers in high-power fiber lasers and amplifiers is introduced. This method allows the determination of active fiber longitudinal temperature distribution at different optical pump powers. PMID:25927761

  20. Transforming growth factor-beta requires its target plasminogen activator inhibitor-1 for cytostatic activity.

    PubMed

    Kortlever, Roderik M; Nijwening, Jeroen H; Bernards, René

    2008-09-01

    The cytokine transforming growth factor beta (TGFbeta) has strong antiproliferative activity in most normal cells but contributes to tumor progression in the later stages of oncogenesis. It is not fully understood which TGFbeta target genes are causally involved in mediating its cytostatic activity. We report here that suppression of the TGFbeta target gene encoding plasminogen activator inhibitor-1 (PAI-1) by RNA interference leads to escape from the cytostatic activity of TGFbeta both in human keratinocytes (HaCaTs) and primary mouse embryo fibroblasts. Consistent with this, PAI-1 knock-out mouse embryo fibroblasts are also resistant to TGFbeta growth arrest. Conversely, we show that ectopic expression of PAI-1 in proliferating HaCaT cells induces a growth arrest. PAI-1 knockdown does not interfere with canonical TGFbeta signaling as judged by SMAD phosphorylation and induction of bona fide TGFbeta target genes. Instead, knockdown of PAI-1 results in sustained activation of protein kinase B. Significantly, we find that constitutive protein kinase B activity leads to evasion of the growth-inhibitory action of TGFbeta. Our data are consistent with a model in which induction of PAI-1 by TGFbeta is critical for the induction of proliferation arrest.

  1. Activation of G Proteins by Guanine Nucleotide Exchange Factors Relies on GTPase Activity.

    PubMed

    Stanley, Rob J; Thomas, Geraint M H

    2016-01-01

    G proteins are an important family of signalling molecules controlled by guanine nucleotide exchange and GTPase activity in what is commonly called an 'activation/inactivation cycle'. The molecular mechanism by which guanine nucleotide exchange factors (GEFs) catalyse the activation of monomeric G proteins is well-established, however the complete reversibility of this mechanism is often overlooked. Here, we use a theoretical approach to prove that GEFs are unable to positively control G protein systems at steady-state in the absence of GTPase activity. Instead, positive regulation of G proteins must be seen as a product of the competition between guanine nucleotide exchange and GTPase activity--emphasising a central role for GTPase activity beyond merely signal termination. We conclude that a more accurate description of the regulation of G proteins via these processes is as a 'balance/imbalance' mechanism. This result has implications for the understanding of intracellular signalling processes, and for experimental strategies that rely on modulating G protein systems. PMID:26986850

  2. Comparative Evaluation of Cutting Methods of Activated Concrete from Nuclear Power Plant Decommissioning - 13548

    SciTech Connect

    Kim, HakSoo; Chung, SungHwan; Maeng, SungJun

    2013-07-01

    The amount of radioactive wastes from decommissioning of a nuclear power plant varies greatly depending on factors such as type and size of the plant, operation history, decommissioning options, and waste treatment and volume reduction methods. There are many methods to decrease the amount of decommissioning radioactive wastes including minimization of waste generation, waste reclassification through decontamination and cutting methods to remove the contaminated areas. According to OECD/NEA, it is known that the radioactive waste treatment and disposal cost accounts for about 40 percentage of the total decommissioning cost. In Korea, it is needed to reduce amount of decommissioning radioactive waste due to high disposal cost, about $7,000 (as of 2010) per a 200 liter drum for the low- and intermediate-level radioactive waste (LILW). In this paper, cutting methods to minimize the radioactive waste of activated concrete were investigated and associated decommissioning cost impact was assessed. The cutting methods considered are cylindrical and volume reductive cuttings. The study showed that the volume reductive cutting is more cost-effective than the cylindrical cutting. Therefore, the volume reductive cutting method can be effectively applied to the activated bio-shield concrete. (authors)

  3. Estimating carbon dioxide emission factors for the California electric power sector

    SciTech Connect

    Marnay, Chris; Fisher, Diane; Murtishaw, Scott; Phadke, Amol; Price, Lynn; Sathaye, Jayant

    2002-08-01

    The California Climate Action Registry (''Registry'') was initially established in 2000 under Senate Bill 1771, and clarifying legislation (Senate Bill 527) was passed in September 2001. The Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley Lab) has been asked to provide technical assistance to the California Energy Commission (CEC) in establishing methods for calculating average and marginal electricity emissions factors, both historic and current, as well as statewide and for sub-regions. This study is exploratory in nature. It illustrates the use of three possible approaches and is not a rigorous estimation of actual emissions factors. While the Registry will ultimately cover emissions of all greenhouse gases (GHGs), presently it is focusing on carbon dioxide (CO2). Thus, this study only considers CO2, which is by far the largest GHG emitted in the power sector. Associating CO2 emissions with electricity consumption encounters three major complications. First, electricity can be generated from a number of different primary energy sources, many of which are large sources of CO2 emissions (e.g., coal combustion) while others result in virtually no CO{sub 2} emissions (e.g., hydro). Second, the mix of generation resources used to meet loads may vary at different times of day or in different seasons. Third, electrical energy is transported over long distances by complex transmission and distribution systems, so the generation sources related to electricity usage can be difficult to trace and may occur far from the jurisdiction in which that energy is consumed. In other words, the emissions resulting from electricity consumption vary considerably depending on when and where it is used since this affects the generation sources providing the power. There is no practical way to identify where or how all the electricity used by a certain customer was generated, but by reviewing public sources of data the total emission burden of a customer's electricity

  4. Implementation of FFT Algorithm using DSP TMS320F28335 for Shunt Active Power Filter

    NASA Astrophysics Data System (ADS)

    Patel, Pinkal Jashvantbhai; Patel, Rajesh M.; Patel, Vinod

    2016-07-01

    This work presents simulation, analysis and experimental verification of Fast Fourier Transform (FFT) algorithm for shunt active power filter based on three-level inverter. Different types of filters can be used for elimination of harmonics in the power system. In this work, FFT algorithm for reference current generation is discussed. FFT control algorithm is verified using PSIM simulation results with DLL block and C-code. Simulation results are compared with experimental results for FFT algorithm using DSP TMS320F28335 for shunt active power filter application.

  5. Quasi-optical solid-state power combining for millimeter-wave active seeker applications

    SciTech Connect

    Halladay, R.H.; Terrill, S.D.; Bowling, D.R.; Gagnon, D.R. U.S. Navy, Naval Air Warfare Center, China Lake, CA )

    1992-05-01

    Consideration is given to quasi-optical power combining techniques, state-of-the-art demonstrated performance, and system issues as they apply to endoatmospheric homing seeker insertion. Quasi-optical power combining is based on combining microwave and millimeter-wave solid-state device power in space through the use of antennas and lenses. It is concluded that quasi-optical power combining meets the severe electrical requirements and packaging constraints of active MMW seekers for endoatmospheric hit-to-kill missiles. The approach provides the possibility of wafer-scale integration of major components for low cost production and offers high reliability. Critical issues include thermal loading and system integration, which must be resolved before the quasi-optical power combining technology will be applied to an active MMW seeker. 18 refs.

  6. Simulation of Series Active and Passive Power Filter Combination System to Mitigate Current Source Harmonics

    NASA Astrophysics Data System (ADS)

    Yusof, Yushaizad; Rahim, Nasrudin Abd.

    2009-08-01

    This paper discusses a combination three phase system of series active power filter and passive power filter used to mitigate current source harmonics produced by a three phase diode rectifier with capacitive loads. A control method based on synchronous reference frame (SRF) is implemented to compensate for the current harmonics. Computer simulation and modelling of the combined filter system is carried out using Matlab/Simulink Power System Blockset (PSB) software. The single tuned passive power filters suppress 5th and 7th order current harmonics, while the series active power filter acts as a harmonic isolator between the source and load. Hence, the proposed system performs very well in mitigating source current harmonics to the level that comply the harmonic standard such as IEEE 519-1992.

  7. Applying Human Factors Evaluation and Design Guidance to a Nuclear Power Plant Digital Control System

    SciTech Connect

    Thomas Ulrich; Ronald Boring; William Phoenix; Emily Dehority; Tim Whiting; Jonathan Morrell; Rhett Backstrom

    2012-08-01

    The United States (U.S.) nuclear industry, like similar process control industries, has moved toward upgrading its control rooms. The upgraded control rooms typically feature digital control system (DCS) displays embedded in the panels. These displays gather information from the system and represent that information on a single display surface. In this manner, the DCS combines many previously separate analog indicators and controls into a single digital display, whereby the operators can toggle between multiple windows to monitor and control different aspects of the plant. The design of the DCS depends on the function of the system it monitors, but revolves around presenting the information most germane to an operator at any point in time. DCSs require a carefully designed human system interface. This report centers on redesigning existing DCS displays for an example chemical volume control system (CVCS) at a U.S. nuclear power plant. The crucial nature of the CVCS, which controls coolant levels and boration in the primary system, requires a thorough human factors evaluation of its supporting DCS. The initial digital controls being developed for the DCSs tend to directly mimic the former analog controls. There are, however, unique operator interactions with a digital vs. analog interface, and the differences have not always been carefully factored in the translation of an analog interface to a replacement DCS. To ensure safety, efficiency, and usability of the emerging DCSs, a human factors usability evaluation was conducted on a CVCS DCS currently being used and refined at an existing U.S. nuclear power plant. Subject matter experts from process control engineering, software development, and human factors evaluated the DCS displays to document potential usability issues and propose design recommendations. The evaluation yielded 167 potential usability issues with the DCS. These issues should not be considered operator performance problems but rather opportunities

  8. Calculated transport properties of CdO: Thermal conductivity and thermoelectric power factor

    NASA Astrophysics Data System (ADS)

    Lindsay, L.; Parker, D. S.

    2015-10-01

    We present first-principles calculations of the thermal and electronic transport properties of the oxide semiconductor CdO. In particular, we find from theory that the accepted thermal conductivity κ value of 0.7 W m-1K-1 is approximately one order of magnitude too small; our calculations of κ of CdO are in good agreement with recent measurements. We also find that alloying of MgO with CdO is an effective means to reduce the lattice contribution to κ , despite MgO having a much larger thermal conductivity. We further consider the electronic structure of CdO in relation to thermoelectric performance, finding that large thermoelectric power factors may occur if the material can be heavily doped p type. This work develops insight into the nature of thermal and electronic transport in an important oxide semiconductor.

  9. Enhanced Molecular Packing of a Conjugated Polymer with High Organic Thermoelectric Power Factor.

    PubMed

    Ma, Wei; Shi, Ke; Wu, Yang; Lu, Zuo-Yu; Liu, Han-Yu; Wang, Jie-Yu; Pei, Jian

    2016-09-21

    The detailed relationship between film morphology and the performance of solution processed n-type organic thermoelectric (TE) devices is investigated. It is interesting to find that the better ordered molecular packing of n-type polymer can be achieved by adding a small fraction of dopant molecules, which is not observed before. The better ordered structure will be favorable for the charge carrier mobility. Meanwhile, dopant molecules improve free carrier concentration via doping reaction. As a result, a significantly enhanced electrical conductivity (12 S cm(-1)) and power factor (25.5 μW m(-1) K(-2)) of TE devices are obtained. Furthermore, the phase separation of conjugated polymer/dopants is observed for the first time with resonant soft X-ray scattering. Our results indicate that the miscibility of conjugated polymers and dopants plays an important role on controlling the morphology and doping efficiency of TE devices.

  10. Accelerated Discovery of Thermoelectric Materials: Combinatorial Facility and High-Throughput Measurement of Thermoelectric Power Factor.

    PubMed

    García-Cañadas, Jorge; Adkins, Nicholas J E; McCain, Stephen; Hauptstein, Bastian; Brew, Ashley; Jarvis, David J; Min, Gao

    2016-06-13

    A series of processes have been developed to facilitate the rapid discovery of new promising thermoelectric alloys. A novel combinatorial facility where elements are wire-fed and laser-melted was designed and constructed. Different sample compositions can be achieved by feeding different element wires at specific rates. The composition of all the samples prepared was tested by energy dispersive X-ray spectroscopy (EDS). Then, their thermoelectric properties (power factor) at room temperature were screened in a specially designed new high-throughput setup. After the screening, the thermoelectric properties can be mapped with the possibility of identifying compositional trends. As a proof-of-concept, a promising thermoelectric ternary system, Al-Fe-Ti, has been identified, demonstrating the capability of this accelerated approach.

  11. Design and real time implementation of single phase boost power factor correction converter.

    PubMed

    Bouafassa, Amar; Rahmani, Lazhar; Mekhilef, Saad

    2015-03-01

    This paper presents a real time implementation of the single-phase power factor correction (PFC) AC-DC boost converter. A combination of higher order sliding mode controller based on super twisting algorithm and predictive control techniques are implemented to improve the performance of the boost converter. Due to the chattering effects, the higher order sliding mode control (HOSMC) is designed. Also, the predictive technique is modified taking into account the large computational delays. The robustness of the controller is verified conducting simulation in MATLAB, the results show good performances in both steady and transient states. An experiment is conducted through a test bench based on dSPACE 1104. The experimental results proved that the proposed controller enhanced the performance of the converter under different parameters variations.

  12. Accelerated Discovery of Thermoelectric Materials: Combinatorial Facility and High-Throughput Measurement of Thermoelectric Power Factor.

    PubMed

    García-Cañadas, Jorge; Adkins, Nicholas J E; McCain, Stephen; Hauptstein, Bastian; Brew, Ashley; Jarvis, David J; Min, Gao

    2016-06-13

    A series of processes have been developed to facilitate the rapid discovery of new promising thermoelectric alloys. A novel combinatorial facility where elements are wire-fed and laser-melted was designed and constructed. Different sample compositions can be achieved by feeding different element wires at specific rates. The composition of all the samples prepared was tested by energy dispersive X-ray spectroscopy (EDS). Then, their thermoelectric properties (power factor) at room temperature were screened in a specially designed new high-throughput setup. After the screening, the thermoelectric properties can be mapped with the possibility of identifying compositional trends. As a proof-of-concept, a promising thermoelectric ternary system, Al-Fe-Ti, has been identified, demonstrating the capability of this accelerated approach. PMID:27186664

  13. Anomalously high thermoelectric power factor in epitaxial ScN thin films

    SciTech Connect

    Kerdsongpanya, Sit; Zukauskaite, Agne; Jensen, Jens; Birch, Jens; Lu Jun; Hultman, Lars; Wingqvist, Gunilla; Eklund, Per; Van Nong, Ngo; Pryds, Nini

    2011-12-05

    Thermoelectric properties of ScN thin films grown by reactive magnetron sputtering on Al{sub 2}O{sub 3}(0001) wafers are reported. X-ray diffraction and elastic recoil detection analyses show that the composition of the films is close to stoichiometry with trace amounts ({approx}1 at. % in total) of C, O, and F. We found that the ScN thin-film exhibits a rather low electrical resistivity of {approx}2.94 {mu}{Omega}m, while its Seebeck coefficient is approximately {approx}-86 {mu}V/K at 800 K, yielding a power factor of {approx}2.5 x 10{sup -3} W/mK{sup 2}. This value is anomalously high for common transition-metal nitrides.

  14. Design and real time implementation of single phase boost power factor correction converter.

    PubMed

    Bouafassa, Amar; Rahmani, Lazhar; Mekhilef, Saad

    2015-03-01

    This paper presents a real time implementation of the single-phase power factor correction (PFC) AC-DC boost converter. A combination of higher order sliding mode controller based on super twisting algorithm and predictive control techniques are implemented to improve the performance of the boost converter. Due to the chattering effects, the higher order sliding mode control (HOSMC) is designed. Also, the predictive technique is modified taking into account the large computational delays. The robustness of the controller is verified conducting simulation in MATLAB, the results show good performances in both steady and transient states. An experiment is conducted through a test bench based on dSPACE 1104. The experimental results proved that the proposed controller enhanced the performance of the converter under different parameters variations. PMID:25457043

  15. An important factor powerfully influencing the Al Ni-based alloys' glass-forming ability

    NASA Astrophysics Data System (ADS)

    Bo, Zhang; Xiufang, Bian; Chunxia, Fu; Na, Han; Jiankun, Zhou; Weimin, Wang

    2005-12-01

    In order to get better glass-forming abilities (GFAs), Ni atoms are partially replaced by Cu and Co atoms in Al84Ni12Zr4 alloys. Thermal analysis shows that the reduced crystallization temperature Trx has no direct correlation with the GFA of the alloys. However, it is notable that prepeaks have been found in the total structure factors of the amorphous Al84Ni(12-x)Zr4Cux and Al84Ni(12-x)Zr4Cox alloys. In addition, the results prove that the intensity of the prepeaks influences the GFA powerfully. The amorphous alloys with larger intensity of the prepeak show better GFA. The influence of prepeaks on the GFA can be explained by the atomic configuration difference among the liquid, crystal and glass states.

  16. Calculated transport properties of CdO: thermal conductivity and thermoelectric power factor

    SciTech Connect

    Lindsay, Lucas R.; Parker, David S.

    2015-10-01

    We present first principles calculations of the thermal and electronic transport properties of the oxide semiconductor CdO. In particular, we find from theory that the accepted thermal conductivity κ value of 0.7 Wm-1K-1 is approximately one order of magnitude too small; our calculations of κ of CdO are in good agreement with recent measurements. We also find that alloying of MgO with CdO is an effective means to reduce the lattice contribution to κ, despite MgO having a much larger thermal conductivity. We further consider the electronic structure of CdO in relation to thermoelectric performance, finding that large thermoelectric power factors may occur if the material can be heavily doped p-type. This work develops insight into the nature of thermal and electronic transport in an important oxide semiconductor.

  17. Enhanced Molecular Packing of a Conjugated Polymer with High Organic Thermoelectric Power Factor.

    PubMed

    Ma, Wei; Shi, Ke; Wu, Yang; Lu, Zuo-Yu; Liu, Han-Yu; Wang, Jie-Yu; Pei, Jian

    2016-09-21

    The detailed relationship between film morphology and the performance of solution processed n-type organic thermoelectric (TE) devices is investigated. It is interesting to find that the better ordered molecular packing of n-type polymer can be achieved by adding a small fraction of dopant molecules, which is not observed before. The better ordered structure will be favorable for the charge carrier mobility. Meanwhile, dopant molecules improve free carrier concentration via doping reaction. As a result, a significantly enhanced electrical conductivity (12 S cm(-1)) and power factor (25.5 μW m(-1) K(-2)) of TE devices are obtained. Furthermore, the phase separation of conjugated polymer/dopants is observed for the first time with resonant soft X-ray scattering. Our results indicate that the miscibility of conjugated polymers and dopants plays an important role on controlling the morphology and doping efficiency of TE devices. PMID:27579521

  18. Primer on Durability of Nuclear Power Plant Reinforced Concrete Structures - A Review of Pertinent Factors

    SciTech Connect

    Naus, Dan J

    2007-02-01

    The objective of this study was to provide a primer on the environmental effects that can affect the durability of nuclear power plant concrete structures. As concrete ages, changes in its properties will occur as a result of continuing microstructural changes (i.e., slow hydration, crystallization of amorphous constituents, and reactions between cement paste and aggregates), as well as environmental influences. These changes do not have to be detrimental to the point that concrete will not be able to meet its performance requirements. Concrete, however, can suffer undesirable changes with time because of improper specifications, a violation of specifications, or adverse performance of its cement paste matrix or aggregate constituents under either physical or chemical attack. Contained in this report is a discussion on concrete durability and the relationship between durability and performance, a review of the historical perspective related to concrete and longevity, a description of the basic materials that comprise reinforced concrete, and information on the environmental factors that can affect the performance of nuclear power plant concrete structures. Commentary is provided on the importance of an aging management program.

  19. Benzothienobenzothiophene-Based Molecular Conductors: High Conductivity, Large Thermoelectric Power Factor, and One-Dimensional Instability.

    PubMed

    Kiyota, Yasuhiro; Kadoya, Tomofumi; Yamamoto, Kaoru; Iijima, Kodai; Higashino, Toshiki; Kawamoto, Tadashi; Takimiya, Kazuo; Mori, Takehiko

    2016-03-23

    On the basis of an excellent transistor material, [1]benzothieno[3,2-b][1]benzothiophene (BTBT), a series of highly conductive organic metals with the composition of (BTBT)2XF6 (X = P, As, Sb, and Ta) are prepared and the structural and physical properties are investigated. The room-temperature conductivity amounts to 4100 S cm(-1) in the AsF6 salt, corresponding to the drift mobility of 16 cm(2) V(-1) s(-1). Owing to the high conductivity, this salt shows a thermoelectric power factor of 55-88 μW K(-2) m(-1), which is a large value when this compound is regarded as an organic thermoelectric material. The thermoelectric power and the reflectance spectrum indicate a large bandwidth of 1.4 eV. These salts exhibit an abrupt resistivity jump under 200 K, which turns to an insulating state below 60 K. The paramagnetic spin susceptibility, and the Raman and the IR spectra suggest 4kF charge-density waves as an origin of the low-temperature insulating state.

  20. Unexpected low thermal conductivity and large power factor in Dirac semimetal Cd3As2

    NASA Astrophysics Data System (ADS)

    Cheng, Zhang; Tong, Zhou; Sihang, Liang; Junzhi, Cao; Xiang, Yuan; Yanwen, Liu; Yao, Shen; Qisi, Wang; Jun, Zhao; Zhongqin, Yang; Faxian, Xiu

    2016-01-01

    Thermoelectrics has long been considered as a promising way of power generation for the next decades. So far, extensive efforts have been devoted to the search of ideal thermoelectric materials, which require both high electrical conductivity and low thermal conductivity. Recently, the emerging Dirac semimetal Cd3As2, a three-dimensional analogue of graphene, has been reported to host ultra-high mobility and good electrical conductivity as metals. Here, we report the observation of unexpected low thermal conductivity in Cd3As2, one order of magnitude lower than the conventional metals or semimetals with a similar electrical conductivity, despite the semimetal band structure and high electron mobility. The power factor also reaches a large value of 1.58 mW·m-1·K-2 at room temperature and remains non-saturated up to 400 K. Corroborating with the first-principles calculations, we find that the thermoelectric performance can be well-modulated by the carrier concentration in a wide range. This work demonstrates the Dirac semimetal Cd3As2 as a potential candidate of thermoelectric materials. Project supported by the National Young 1000 Talent Plan China, the Pujiang Talent Plan in Shanghai, China, the National Natural Science Foundation of China (Grant Nos. 61322407 and 11474058), the Fund for Fostering Talents in Basic Science of the National Natural Science Foundation of China (Grant No. J1103204), and the National Basic Research Program of China (Grant No. 2011CB921803).

  1. Wounding activates p38 map kinase and activation transcription factor 3 in leading keratinocytes.

    PubMed

    Harper, Erin G; Alvares, Stacy M; Carter, William G

    2005-08-01

    Quiescent epidermis anchors to laminin 5 in the basement membrane via integrin alpha6beta4. Wounding elevates expression of laminin 5, generating leading keratinocytes (LKs) that migrate via beta1 integrins. Laminin 5 was evaluated as a regulator of cell signaling, and mRNA and protein expression in LKs. An in vitro wound model was developed based on suspension and re-adhesion of quiescent human keratinocytes (HKs). DNA microarrays identified multiple mRNAs elevated 1.5 hours after suspension and re-adhesion including activation transcription factor 3 (ATF3). In vitro and in vivo, levels of ATF3 protein elevate in nuclei of LKs, but not in nuclei of the following cells, 2 hours after suspension or wounding but decline by 12-18 hours post injury. Significantly, null defects in laminin 5 or integrin beta4 that inhibit anchorage chronically elevate ATF3 in vivo. This suggests that adhesion to laminin 5, but not other ligands, suppresses activation. On suspension, ATF3 and other transcripts in the microarrays are elevated by phosphorylated p38 mitogen-activated protein kinase (P-p38), a stress kinase that regulates mRNA and cell motility. Inhibition of P-p38 with SB203580 prevents phosphorylation of ATF2, a transcription factor for ATF3 in LKs. Re-adhesion to laminin 5 via alpha6beta4 dephosphorylates P-p38 and suppresses ATF3 protein relative to cells in suspension. Thus, wounding of quiescent HKs disrupts laminin 5 adhesion to activate p38, generating mRNA transcripts that define LKs. Adhesion to deposits of laminin 5 via alpha6beta4 suppresses P-p38 and activation mRNAs including ATF3. Defects in laminin 5 and alpha6beta4 sustain P-p38 with probable pathological effects on transcription and migration.

  2. Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators

    PubMed Central

    Chen, Ming-Hung

    2015-01-01

    This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters. PMID:26451391

  3. Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators.

    PubMed

    Chen, Ming-Hung

    2015-01-01

    This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters.

  4. Development of Shunt-Type Three-Phase Active Power Filter with Novel Adaptive Control for Wind Generators.

    PubMed

    Chen, Ming-Hung

    2015-01-01

    This paper proposes a new adaptive filter for wind generators that combines instantaneous reactive power compensation technology and current prediction controller, and therefore this system is characterized by low harmonic distortion, high power factor, and small DC-link voltage variations during load disturbances. The performance of the system was first simulated using MATLAB/Simulink, and the possibility of an adaptive digital low-pass filter eliminating current harmonics was confirmed in steady and transient states. Subsequently, a digital signal processor was used to implement an active power filter. The experimental results indicate, that for the rated operation of 2 kVA, the system has a total harmonic distortion of current less than 5.0% and a power factor of 1.0 on the utility side. Thus, the transient performance of the adaptive filter is superior to the traditional digital low-pass filter and is more economical because of its short computation time compared with other types of adaptive filters. PMID:26451391

  5. Platelet activating factor raises intracellular calcium ion concentration in macrophages

    PubMed Central

    1986-01-01

    Peritoneal cells from thioglycollate-stimulated mice were allowed to adhere to coverglasses for 2 h to give a dense monolayer of adherent cells greater than 95% of which were macrophages. After incubation with the tetra-acetoxymethyl ester of quin2, coverglasses were rinsed with Ca2+-free saline, oriented at a 45 degree angle in square cuvettes containing a magnetically driven stir bar, and analyzed for changes in quin2 fluorescence in a spectrofluorimeter. Such fluorescence, taken as an indication of intracellular calcium ion concentration ([Ca2+]i), increased as exogenous calcium ion concentration ([Ca2+]o) was raised to 1 mM. At [Ca2+]o approximately equal to 10 microM, [Ca2+]i = 72 +/- 14 nM (n = 26); at [Ca2+]o = 1 mM, [Ca2+]i = 140-220 nM, levels not increased by N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine, a membrane-permeant chelator of heavy metals than can quench quin2. Addition of mouse alpha + beta fibroblast interferon, lipopolysaccharide, thrombin, collagen, vasopressin, ADP, compound 48/80, or U46619 did not change [Ca2+]i. However, addition of platelet activating factor (PAF) (2-20 ng/ml) raised [Ca2+]i by 480 nM within 1 min if [Ca2+]o = 1 mM. In the presence of 5 mM EGTA, PAF raised [Ca2+]i by 25 nM. This suggests that PAF causes influx of exogenous Ca2+, as well as releasing some Ca2+ from intracellular stores. Consistent with these results, when PAF was added to 1 mM Ca2+ in the presence of 100 microM Cd2+ or Mn2+ to block Ca2+ influx, [Ca2+]i increased by only intermediate amounts; at the times of such dampened peak response, [Ca2+]i could be raised within 1 min to normal PAF-stimulated levels by chelation of the exogenous heavy metals with diethylenetriaminepentaacetic acid. Normal PAF responses were observed in the presence of indomethacin. The lowest dose of PAF observed to raise [Ca2+]i was 0.1 ng/ml. Response of [Ca2+]i to 2-20 ng/ml PAF was transient, and second applications had no effect. The PAF response also was seen in

  6. The Yersinia pseudotuberculosis cytotoxic necrotizing factor (CNFY) selectively activates RhoA.

    PubMed

    Hoffmann, Claudia; Pop, Marius; Leemhuis, Jost; Schirmer, Jörg; Aktories, Klaus; Schmidt, Gudula

    2004-04-16

    The cytotoxic necrotizing factors (CNF)1 and CNF2 from pathogenic Escherichia coli strains activate RhoA, Rac1, and Cdc42 by deamidation of Gln63 (RhoA) or Gln61 (Rac and Cdc42). Recently, a novel cytotoxic necrotizing factor termed CNFY was identified in Yersinia pseudotuberculosis strains (Lockman, H. A., Gillespie, R. A., Baker, B. D., and Shakhnovich, E. (2002) Infect. Immun. 70, 2708-2714). We amplified the cnfy gene from genomic DNA of Y. pseudotuberculosis, cloned and expressed the recombinant protein, and studied its activity. Recombinant GST-CNFY induced morphological changes in HeLa cells and caused an upward shift of RhoA in SDS-PAGE, as is known for GST-CNF1 and GST-CNF2. Mass spectrometric analysis of GST-CNFY-treated RhoA confirmed deamidation at Glu63. Treatment of RhoA, Rac1, and Cdc42 with GST-CNFY decreased their GTPase activities, indicating that all of these Rho proteins could serve as substrates for GST-CNFY in vitro. In contrast, RhoA, but not Rac or Cdc42, was the substrate of GST-CNFY in culture cells. GST-CNFY caused marked stress fiber formation in HeLa cells after 2 h. In contrast to GST-CNF1, formation of filopodia or lamellipodia was not induced with GST-CNFY. Accordingly, effector pull-down experiments with lysates of toxin-treated cells revealed strong activation of RhoA but no activation of Rac1 or Cdc42 after 6 h of GST-CNFY-treatment. Moreover, in rat hippocampal neurons, GST-CNFY results in the retraction of neurites, indicating RhoA activation. In contrast, no activation of Rac or Cdc42 was found. Altogether, our data suggest that CNFY from Y. pseudotuberculosis is a strong, selective activator of RhoA, which can be used as a powerful tool for constitutive RhoA activation without concomitant activation of Rac1 or Cdc42. PMID:14761941

  7. Lethal Factor Active-Site Mutations Affect Catalytic Activity In Vitro

    PubMed Central

    Hammond, S. E.; Hanna, P. C.

    1998-01-01

    The lethal factor (LF) protein of Bacillus anthracis lethal toxin contains the thermolysin-like active-site and zinc-binding consensus motif HEXXH (K. R. Klimpel, N. Arora, and S. H. Leppla, Mol. Microbiol. 13:1093–1100, 1994). LF is hypothesized to act as a Zn2+ metalloprotease in the cytoplasm of macrophages, but no proteolytic activities have been previously shown on any target substrate. Here, synthetic peptides are hydrolyzed by LF in vitro. Mass spectroscopy and peptide sequencing of isolated cleavage products separated by reverse-phase high-pressure liquid chromatography indicate that LF seems to prefer proline-containing substrates. Substitution mutations within the consensus active-site residues completely abolish all in vitro catalytic functions, as does addition of 1,10-phenanthroline, EDTA, and certain amino acid hydroxamates, including the novel zinc metalloprotease inhibitor ZINCOV. In contrast, the protease inhibitors bestatin and lysine CMK, previously shown to block LF activity on macrophages, did not block LF activity in vitro. These data provide the first direct evidence that LF may act as an endopeptidase. PMID:9573135

  8. Regulation of platelet activating factor receptor coupled phosphoinositide-specific phospholipase C activity

    SciTech Connect

    Morrison, W.J.

    1988-01-01

    The major objectives of this study were two-fold. The first was to establish whether binding of platelet activating factor (PAF) to its receptor was integral to the stimulation of polyphosphoinositide-specific phospholipase C (PLC) in rabbit platelets. The second was to determine regulatory features of this receptor-coupled mechanism. ({sup 3}H)PAF binding demonstrated two binding sites, a high affinity site with a inhibitory constant (Ki) of 2.65 nM and a low affinity site with a Ki of 0.80 {mu}M. PAF receptor coupled activation of phosphoinositide-specific PLC was studied in platelets which were made refractory, by short term pretreatments, to either PAF or thrombin. Saponin-permeabilized rabbit platelets continue to regulate the mechanism(s) coupling PAF receptors to PLC stimulation. However, TRP{gamma}S and GDP{beta}S, which affect guanine nucleotide regulatory protein functions, were unable to modulate the PLC activity to any appreciable extent as compared to PAF. The possible involvement of protein kinase C (PKC) activation in regulating PAF-stimulated PLC activity was studied in rabbit platelets pretreated with staurosporine followed by pretreatments with PAF or phorbol 12-myristate 13-acetate (PMA).

  9. Manufacture of magnetically active fiber-reinforced composites for use in power generation

    NASA Astrophysics Data System (ADS)

    Etches, Julie; Bond, Ian; Mellor, Phil

    2004-07-01

    A major issue yet to be resolved for embedding sensors, actuators and microelectromechanical systems (MEMS) in 'smart' structures is that of providing power. Work is ongoing in the field with examples of micro battery technology, use of solar power and micro fuel cells. The work presented here considers a technology to enable the development of integrated power generation and actuation. Magnetic fibre reinforced composite material has been developed which utilises hollow glass fibres filled with active magnetic material. The resulting material maintains structural integrity as well as providing a possible means of electrical power generation from a dynamically loaded structure. The hollow glass fibres were manufactured in-house using a bespoke fibre drawing facility. Hard magnetic powder materials were introduced into the hollow fibre cores to provide an active electromagnetic function. This paper will discuss the manufacture, characterization and optimisation of active magnetic fibre reinforced composite materials.

  10. Mobilization of hepatic calcium pools by platelet activating factor

    SciTech Connect

    Lapointe, D.S.; Hanahan, D.J.; Olson, M.S.

    1987-03-24

    In the perfused rat liver, platelet activating factor, 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (AGEPC), infusion produces an extensive but transient glycogenolytic response which at low AGEPC concentrations is markedly dependent upon the perfusate calcium levels. The role of calcium in the glycogenolytic response of the liver to AGEPC was investigated by assessing the effect of AGEPC on various calcium pools in the intact liver. Livers from fed rats were equilibrated with /sup 45/Ca/sup 2 +/, and the kinetics of /sup 45/Ca/sup 2 +/ efflux were determined in control, AGEPC-stimulated, and phenylephrine-stimulated livers during steady-state washout of /sup 45/Ca/sup 2 +/. AGEPC treatment had only a slight if any effect on the pattern of steady-state calcium efflux from the liver, as opposed to major perturbations in the pattern of calcium efflux effected by the ..cap alpha..-adrenergic agonist phenylephrine. Infusion of short pulses of AGEPC during the washout of /sup 45/Ca/sup 2 +/ from labeled livers caused a transient release of /sup 45/Ca/sup 2 +/ which was not abolished at low calcium concentrations in the perfusate. Infusion of latex beads, which are removed by the reticuloendothelial cells, caused the release of hepatic /sup 45/Ca/sup 2 +/ in a fashion similar to the case with AGEPC. The findings indicate that AGEPC does not perturb a major pool of calcium within the liver as occurs upon ..cap alpha..-adrenergic stimulation; it is likely that AGEPC mobilizes calcium from a smaller yet very important pool, very possibly from nonparenchymal cells in the liver.

  11. Tumor necrosis factor-inducing activities of Cryptococcus neoformans components.

    PubMed Central

    Delfino, D; Cianci, L; Migliardo, M; Mancuso, G; Cusumano, V; Corradini, C; Teti, G

    1996-01-01

    Cryptococcus neoformans-induced tumor necrosis factor alpha (TNF-alpha) production may lead to increased human immunodeficiency virus replication in patients with AIDS. In order to identify cryptococcal components that are predominantly responsible for stimulating TNF production, various concentrations of glucuronoxylomannan (GXM), galactoxylomannan (GalXM), mannoproteins (MP), and alpha(1-3) [corrected] glucan were added to whole-blood cultures. All of the cryptococcal components tested, as well as whole heat-killed cryptococci, were capable of inducing TNF-alpha release in a dose-dependent manner. MP were significantly more potent than any of the other cryptococcal components tested or heat-killed cryptococci in stimulating TNF-alpha production (P < 0.05). GXM, in contrast, was significantly less potent in this activity than either GalXM or MP (P < 0.05). As little as 0.5 microg of MP per ml was sufficient to produce moderate but significant elevations of TNF-alpha release. Maximal MP-induced TNF-alpha levels were similar to those induced by Salmonella enteritidis lipopolysaccharide, our positive control. Further experiments using isolated leukocytes suggested that monocytes were the cell population mainly responsible for TNF-alpha production, although the participation of other cell types could not be excluded. The presence of complement-sufficient plasma was a necessary requirement for TNF-alpha induction by GXM, GalXM, and low doses of MP. High MP concentrations (100 microg/ml) were also capable of stimulating TNF-alpha production in the absence of plasma. These data indicate that soluble products released by C. neoformans are capable of inducing TNF-alpha secretion in human leukocytes. This may be clinically relevant, since high concentrations of such products are frequently found in the body fluids of AIDS patients infected with C. neoformans. PMID:8945566

  12. Hepatocyte growth factor, hepatocyte growth factor activator and arginine in a rat fulminant colitis model

    PubMed Central

    Zwintscher, Nathan P.; Shah, Puja M.; Salgar, Shashikumar K.; Newton, Christopher R.; Maykel, Justin A.; Samy, Ahmed; Jabir, Murad; Steele, Scott R.

    2016-01-01

    Introduction Dextran sodium sulfate (DSS) is commonly used to induce a murine fulminant colitis model. Hepatocyte growth factor (HGF) has been shown to decrease the symptoms of inflammatory bowel disease (IBD) but the effect of its activator, HGFA, is not well characterized. Arginine reduces effects of oxidative stress but its effect on IBD is not well known. The primary aim is to determine whether HGF and HGFA, or arginine will decrease IBD symptoms such as pain and diarrhea in a DSS-induced fulminant colitis murine model. Methods A severe colitis was induced in young, male Fischer 344 rats with 4% (w/v) DSS oral solution for seven days; rats were sacrificed on day 10. Rats were divided into five groups of 8 animals: control, HGF (700 mcg/kg/dose), HGF and HGFA (10 mcg/dose), HGF and arginine, and high dose HGF (2800 mcg/kg/dose). Main clinical outcomes were pain, diarrhea and weight loss. Blinded pathologists scored the terminal ileum and distal colon. Results DSS reliably induced severe active colitis in 90% of animals (n = 36/40). There were no differences in injury scores between control and treatment animals. HGF led to 1.38 fewer days in pain (p = 0.036), while arginine led to 1.88 fewer days of diarrhea (P = 0.017) compared to controls. 88% of HGFA-treated rats started regaining weight (P < 0.001). Discussion/Conclusion Although treatment was unable to reverse fulminant disease, HGF and arginine were associated with decreased days of pain and diarrhea. These clinical interventions may reduce associated symptoms for severe IBD patients, even when urgent surgical intervention remains the only viable option. PMID:27144006

  13. An embryonic myosin converter domain influences Drosophila indirect flight muscle stretch activation, power generation and flight.

    PubMed

    Wang, Qian; Newhard, Christopher S; Ramanath, Seemanti; Sheppard, Debra; Swank, Douglas M

    2014-01-15

    Stretch activation (SA) is critical to the flight ability of insects powered by asynchronous, indirect flight muscles (IFMs). An essential muscle protein component for SA and power generation is myosin. Which structural domains of myosin are significant for setting SA properties and power generation levels is poorly understood. We made use of the transgenic techniques and unique single muscle myosin heavy chain gene of Drosophila to test the influence of the myosin converter domain on IFM SA and power generation. Replacing the endogenous converter with an embryonic version decreased SA tension and the rate of SA tension generation. The alterations in SA properties and myosin kinetics from the converter exchange caused power generation to drop to 10% of control fiber power when the optimal conditions for control fibers - 1% muscle length (ML) amplitude and 150 Hz oscillation frequency - were applied to fibers expressing the embryonic converter (IFI-EC). Optimizing conditions for IFI-EC fiber power production, by doubling ML amplitude and decreasing oscillation frequency by 60%, improved power output to 60% of optimized control fiber power. IFI-EC flies altered their aerodynamic flight characteristics to better match optimal fiber power generation conditions as wing beat frequency decreased and wing stroke amplitude increased. This enabled flight in spite of the drastic changes to fiber mechanical performance.

  14. An embryonic myosin converter domain influences Drosophila indirect flight muscle stretch activation, power generation and flight

    PubMed Central

    Wang, Qian; Newhard, Christopher S.; Ramanath, Seemanti; Sheppard, Debra; Swank, Douglas M.

    2014-01-01

    Stretch activation (SA) is critical to the flight ability of insects powered by asynchronous, indirect flight muscles (IFMs). An essential muscle protein component for SA and power generation is myosin. Which structural domains of myosin are significant for setting SA properties and power generation levels is poorly understood. We made use of the transgenic techniques and unique single muscle myosin heavy chain gene of Drosophila to test the influence of the myosin converter domain on IFM SA and power generation. Replacing the endogenous converter with an embryonic version decreased SA tension and the rate of SA tension generation. The alterations in SA properties and myosin kinetics from the converter exchange caused power generation to drop to 10% of control fiber power when the optimal conditions for control fibers – 1% muscle length (ML) amplitude and 150 Hz oscillation frequency – were applied to fibers expressing the embryonic converter (IFI-EC). Optimizing conditions for IFI-EC fiber power production, by doubling ML amplitude and decreasing oscillation frequency by 60%, improved power output to 60% of optimized control fiber power. IFI-EC flies altered their aerodynamic flight characteristics to better match optimal fiber power generation conditions as wing beat frequency decreased and wing stroke amplitude increased. This enabled flight in spite of the drastic changes to fiber mechanical performance. PMID:24115062

  15. Platelet-activating factor (PAF) receptor-binding antagonist activity of Malaysian medicinal plants.

    PubMed

    Jantan, I; Rafi, I A A; Jalil, J

    2005-01-01

    Forty-nine methanol extracts of 37 species of Malaysian medicinal plants were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets, using 3H-PAF as a ligand. Among them, the extracts of six Zingiberaceae species (Alpinia galanga Swartz., Boesenbergia pandurata Roxb., Curcuma ochorrhiza Val., C. aeruginosa Roxb., Zingiber officinale Rosc. and Z. zerumbet Koenig.), two Cinnamomum species (C. altissimum Kosterm. and C. pubescens Kochummen.), Goniothalamus malayanus Hook. f. Momordica charantia Linn. and Piper aduncum L. are potential sources of new PAF antagonists, as they showed significant inhibitory effects with IC50 values ranging from 1.2 to 18.4 microg ml(-1).

  16. The effectiveness of power-generating complexes constructed on the basis of nuclear power plants combined with additional sources of energy determined taking risk factors into account

    NASA Astrophysics Data System (ADS)

    Aminov, R. Z.; Khrustalev, V. A.; Portyankin, A. V.

    2015-02-01

    The effectiveness of combining nuclear power plants equipped with water-cooled water-moderated power-generating reactors (VVER) with other sources of energy within unified power-generating complexes is analyzed. The use of such power-generating complexes makes it possible to achieve the necessary load pickup capability and flexibility in performing the mandatory selective primary and emergency control of load, as well as participation in passing the night minimums of electric load curves while retaining high values of the capacity utilization factor of the entire power-generating complex at higher levels of the steam-turbine part efficiency. Versions involving combined use of nuclear power plants with hydrogen toppings and gas turbine units for generating electricity are considered. In view of the fact that hydrogen is an unsafe energy carrier, the use of which introduces additional elements of risk, a procedure for evaluating these risks under different conditions of implementing the fuel-and-hydrogen cycle at nuclear power plants is proposed. Risk accounting technique with the use of statistical data is considered, including the characteristics of hydrogen and gas pipelines, and the process pipelines equipment tightness loss occurrence rate. The expected intensities of fires and explosions at nuclear power plants fitted with hydrogen toppings and gas turbine units are calculated. In estimating the damage inflicted by events (fires and explosions) occurred in nuclear power plant turbine buildings, the US statistical data were used. Conservative scenarios of fires and explosions of hydrogen-air mixtures in nuclear power plant turbine buildings are presented. Results from calculations of the introduced annual risk to the attained net annual profit ratio in commensurable versions are given. This ratio can be used in selecting projects characterized by the most technically attainable and socially acceptable safety.

  17. Activation of coagulation after administration of tumor necrosis factor to normal subjects.

    PubMed

    van der Poll, T; Büller, H R; ten Cate, H; Wortel, C H; Bauer, K A; van Deventer, S J; Hack, C E; Sauerwein, H P; Rosenberg, R D; ten Cate, J W

    1990-06-01

    Tumor necrosis factor has been implicated in the activation of blood coagulation in septicemia, a condition commonly associated with intravascular coagulation and disturbances of hemostasis. To evaluate the early dynamics and the route of the in vivo coagulative response to tumor necrosis factor, we performed a controlled study in six healthy men, monitoring the activation of the common and intrinsic pathways of coagulation with highly sensitive and specific radioimmunoassays. Recombinant human tumor necrosis factor, administered as an intravenous bolus injection (50 micrograms per square meter of body-surface area), induced an early and short-lived rise in circulating levels of the activation peptide of factor X, reaching maximal values after 30 to 45 minutes (mean +/- SEM increase after 45 minutes, 34.2 +/- 18.2 percent; tumor necrosis factor vs. saline, P = 0.015). This was followed by a gradual and prolonged increase in the plasma concentration of the prothrombin fragment F1+2, peaking after four to five hours (mean increase after five hours, 348.0 +/- 144.8 percent; tumor necrosis factor vs. saline, P less than 0.0001). These findings signify the formation of factor Xa (activated factor X) and the activation of prothrombin. Activation of the intrinsic pathway could not be detected by a series of measurements of the plasma levels of factor XII, prekallikrein, factor XIIa-C1 inhibitor complexes, kallikrein-C1 inhibitor complexes, and the activation peptide of factor IX. The delay between the maximal activation of factor X and that of prothrombin amounted to several hours, indicating that neutralization of factor Xa activity was slow. We conclude that a single injection of tumor necrosis factor elicits a rapid and sustained activation of the common pathway of coagulation, probably induced through the extrinsic route. Our results suggest that tumor necrosis factor could play an important part in the early activation of the hemostatic mechanism in septicemia.

  18. Thioredoxin and Thioredoxin Reductase Control Tissue Factor Activity by Thiol Redox-dependent Mechanism*

    PubMed Central

    Wang, Pei; Wu, Yunfei; Li, Xiaoming; Ma, Xiaofeng; Zhong, Liangwei

    2013-01-01

    Abnormally enhanced tissue factor (TF) activity is related to increased thrombosis risk in which oxidative stress plays a critical role. Human cytosolic thioredoxin (hTrx1) and thioredoxin reductase (TrxR), also secreted into circulation, have the power to protect against oxidative stress. However, the relationship between hTrx1/TrxR and TF remains unknown. Here we show reversible association of hTrx1 with TF in human serum and plasma samples. The association is dependent on hTrx1-Cys-73 that bridges TF-Cys-209 via a disulfide bond. hTrx1-Cys-73 is absolutely required for hTrx1 to interfere with FVIIa binding to purified and cell-surface TF, consequently suppressing TF-dependent procoagulant activity and proteinase-activated receptor-2 activation. Moreover, hTrx1/TrxR plays an important role in sensing the alterations of NADPH/NADP+ states and transducing this redox-sensitive signal into changes in TF activity. With NADPH, hTrx1/TrxR readily facilitates the reduction of TF, causing a decrease in TF activity, whereas with NADP+, hTrx1/TrxR promotes the oxidation of TF, leading to an increase in TF activity. By comparison, TF is more likely to favor the reduction by hTrx1-TrxR-NADPH. This reversible reduction-oxidation reaction occurs in the TF extracellular domain that contains partially opened Cys-49/-57 and Cys-186/-209 disulfide bonds. The cell-surface TF procoagulant activity is significantly increased after hTrx1-knockdown. The response of cell-surface TF procoagulant activity to H2O2 is efficiently suppressed through elevating cellular TrxR activity via selenium supplementation. Our data provide a novel mechanism for redox regulation of TF activity. By modifying Cys residues or regulating Cys redox states in TF extracellular domain, hTrx1/TrxR function as a safeguard against inappropriate TF activity. PMID:23223577

  19. Rat prostate tumors express cancer procoagulant, an activator of coagulation factor X.

    PubMed

    Kamocka, Malgorzata; Pollard, Morris; Suckow, Mark; Mielicki, Wojciech P; Rosen, Elliot D

    2008-06-01

    Two common procoagulant activities associated with tumors are tissue factor and cancer procoagulant (CP), an activator of coagulation factor X. We have identified a convenient source of CP in transplanted Lobund-Wistar rat PA3 prostate tumors. CP activity was purified from 5 independent transplanted prostate tumors by column chromatography. The protein activated factor X in the absence of TF and factor VII. An antihuman CP antibody recognized rat CP in an ELISA and inactivated CP activity in a chromogenic assay. Lobund-Wistar prostate tumors may provide a convenient animal model useful in determining the role of CP in cancer development.

  20. The nuclear factor SPBP contains different functional domains and stimulates the activity of various transcriptional activators.

    PubMed

    Rekdal, C; Sjøttem, E; Johansen, T

    2000-12-22

    SPBP (stromelysin-1 platelet-derived growth factor-responsive element binding protein) was originally cloned from a cDNA expression library by virtue of its ability to bind to a platelet-derived growth factor-responsive element in the human stromelysin-1 promoter. A 937-amino acid-long protein was deduced from a 3995-nucleotide murine cDNA sequence. By analyses of both human and murine cDNAs, we now show that SPBP is twice as large as originally found. The human SPBP gene contains six exons and is located on chromosome 22q13.1-13.3. Two isoforms differing in their C termini are expressed due to alternative splicing. PCR analyses of multitissue cDNA panels showed that SPBP is expressed in most tissues except for ovary and prostate. Functional mapping revealed that SPBP is a nuclear, multidomain protein containing an N-terminal region with transactivating ability, a novel type of DNA-binding domain containing an AT hook motif, and a bipartite nuclear localization signal as well as a C-terminal zinc finger domain. This type of zinc finger domain is also found in the trithorax family of chromatin-based transcriptional regulator proteins. Using cotransfection experiments, we find that SPBP enhances the transcriptional activity of various transcription factors such as c-Jun, Ets1, Sp1, and Pax6. Hence, SPBP seems to act as a transcriptional coactivator. PMID:10995766

  1. Reanalysis with optimized power of red blood cell acetylcholinesterase activity from a 1-year dietary treatment of dogs to chlorpyrifos.

    PubMed

    Mattsson, J L; Holden, L; Eisenbrandt, D L; Gibson, J E

    2001-03-01

    A no-observed-effect level (NOEL) of 0.1 mg/kg/day was reported for inhibition of red blood cell (RBC) acetylcholinesterase (AChE) in two groups of Beagle dogs fed chlorpyrifos (0, 0.01, 0.03, 0.1, 1 or 3 mg/kg/day) in the diet for 1 or 2 years (McCollister et al., Food Cosmet. Toxicol. 12 (1974) 45-61). The statistical analyses were by t-test that had low statistical power due to small sample sizes. Common time points for blood samples in both phases allowed a reanalysis of the grouped data over a 1-year time period. The reanalysis increased statistical power by increasing the sample size to n=14 from n=3 or 4, and decreasing the variance, by statistical step-by-step aggregation of the data from both phases, both sexes, and four sample periods. Factors retained in the ANOVA were dose, sex, and phase (sex-by-dose was not significant). Contrasts with one-sided t-tests indicated the 1 and 3 mg/kg/day groups had significantly inhibited RBC AChE (P<0.0001). At alpha=0.05, the uncorrected one-sided model had 80% power to detect a 12% decrease, 93% power for a 15% decrease, and 99.5% power for a 20% decrease in AChE activity. Overall, the reanalysis had high power to detect a clinically significant decrease in RBC AChE activity, and substantiated the original NOEL for chronic treatment of dogs to dietary chlorpyrifos at 0.1 mg/kg/day. PMID:11246135

  2. 75 FR 80114 - Agency Information Collection (Obligation To Report Factors Affecting Entitlement) Activity Under...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... AFFAIRS Agency Information Collection (Obligation To Report Factors Affecting Entitlement) Activity Under... INFORMATION: Title: Obligation to Report Factors Affecting Entitlement (38 CFR 3.204(a)(1), 38 CFR 3.256(a... compensation benefits must report changes in their entitlement factors. Individual factors such as...

  3. Tritium activities in Canada supporting CANDU{sup R} nuclear power reactors

    SciTech Connect

    Miller, J. M.

    2008-07-15

    An overview of the various Canadian tritium research and operational activities supporting the development, refurbishment and operation of CANDU{sup R} nuclear power reactors is presented. These activities encompass tritium health and safety, tritium in the environment, tritium interaction with materials, and tritium processing, and relate to both supporting R and D advances as well as operational best practices. The collective results of these activities contribute to our goals of improving worker and public safety, and operational efficiency. (authors)

  4. Flame-powered trigger device for activating explosion-suppression barrier. Rept. of Investigations/1991

    SciTech Connect

    Cortese, R.A.; Sapko, M.J.

    1991-01-01

    The U.S. Bureau of Mines has developed a flame-radiation-powered trigger device to explosively activate suppression barriers to quench gas and coal dust explosions. The major component of the device is a silicon solar panel, which converts radiation from the developing explosion into electrical energy to initiate an electric detonator, which releases an extinguishing agent into the advancing flame front. Solar panels that are rated to produce 20 W of electrical power when exposed to the sunlight are producing about 200 W when exposed to a full-scale dust explosion. The solar panel is electrically isolated from the detonator by a pressure-sensitive switch until the arrival of the precursor pressure pulse, which always precedes a deflagration. The combination of pressure arming and flame-powered photogenerator prevents false barrier activation and requires no external power supply.

  5. Alternative pathways of thromboplastin-dependent activation of human factor X in plasma

    SciTech Connect

    Marlar, R.A.; Griffin, J.H.

    1981-01-01

    To determine the interrelationships of the major coagulation pathways, the activation of 3H-labeled factor X in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin and calcium were added to plasma samples containing 3H-factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin, the rate of factor X activation in plasmas deficient in factor VIII or factor IX was 10% of the activation rate of normal plasma or of factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, reconstituted normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these plasma experiments, it is inferred that the dilute thromboplastin-dependent activation of factor X requires factors VII, IX, and VIII. An alternative extrinsic pathway that involves factors IX and VIII may be the physiologic extrinsic pathway and hence help to explain the consistent clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.

  6. Smart Technique for Induction Motors Diagnosis by Monitoring the Power Factor Using Only the Measured Current

    NASA Astrophysics Data System (ADS)

    Shnibha, R. A.; Albarabar, A. S.

    2012-05-01

    This paper is concerned with accurate, early and reliable induction motor IM fault detection and diagnosis using an enhanced power parameter measurement technique. IM protection devices typically monitor the motor current and/or voltage to provide the motor protection from e.g. current overload, over/under voltage, etc. One of the interesting parameters to monitor is the operating power factor (PF) of the IM which provides better under-load protection compared to the motor current based approaches. The PF of the motor is determined by the level of the current and voltage that are drawn, and offers non-intrusive monitoring. Traditionally, PF estimation would require both voltage and the current measurements to apply the displacement method. This paper will use a method of determining the operating PF of the IM using only the measured current and the manufacturer data that are typically available from the nameplate and/or datasheet for IM monitoring. The novelty of this work lies in detecting very low phase imbalance related faults and misalignment. Much of the previous work has dealt with detecting phase imbalance faults at higher degrees of severity, i.e. voltage drops of 10% or more. The technique was tested by empirical measurements on test rig comprised a 1.1 kW variable speed three phase induction motor with varying output load (No load, 25%, 50%, 75% and 100% load). One common faults was introduced; imbalance in one phase as the electrical fault The experimental results demonstrate that the PF can be successfully applied for IM fault diagnosis and the present study shows that severity fault detection using PF is promising. The proposed method offers a potentially reliable, non-intrusive, and inexpensive CM tool which can be implemented with real-time monitoring systems

  7. Activities in support of continuing the service of nuclear power plant concrete structures

    SciTech Connect

    Naus, Dan J

    2012-01-01

    In general, nuclear power plant concrete structure s performance has been very good; however, aging of concrete structures occurs with the passage of time that can potentially result in degradation if is effects are not controlled. Safety-related nuclear power plant concrete structures are described. In-service inspection and testing requirements in the U.S. are summarized. The interaction of the license renewal process and concrete structures is noted. A summary of operating experience related to aging of nuclear power plant concrete structures is provided. Several candidate areas are identified where additional research would be beneficial for aging management of nuclear power plant concrete structures. Finally, an update on recent activities at Oak Ridge National Laboratory related to aging management of nuclear power plant concrete structures is provided.

  8. An energy harvesting system for passively generating power from human activities

    NASA Astrophysics Data System (ADS)

    Rao, Yuan; Cheng, Shuo; Arnold, David P.

    2013-11-01

    This paper presents a complete, self-contained energy harvesting system composed of a magnetic energy harvester, an input-powered interface circuit and a rechargeable battery. The system converts motion from daily human activities such as walking, jogging, and cycling into usable electrical energy. By using an input-powered interface circuit, the system requires no external power supplies and features zero standby power when the input motion is too small for successful energy reclamation. When attached to a person's ankle during walking, the 100 cm3 system prototype is shown to charge a 3.7 V, 65 mAh lithium-ion polymer battery at an average power of 300 µW. The design and testing of the system under other operating conditions are presented herein.

  9. Possible factors determining the non-linearity in the VO2-power output relationship in humans: theoretical studies.

    PubMed

    Korzeniewski, Bernard; Zoladz, Jerzy A

    2003-08-01

    At low power output exercise (below lactate threshold), the oxygen uptake increases linearly with power output, but at high power output exercise (above lactate threshold) some additional oxygen consumption causes a non-linearity in the overall VO(2) (oxygen uptake rate)-power output relationship. The functional significance of this phenomenon for human exercise tolerance is very important, but the mechanisms underlying it remain unknown. In the present work, a computer model of oxidative phosphorylation in intact skeletal muscle developed previously is used to examine the background of this relationship in different modes of exercise. Our simulations demonstrate that the non-linearity in the VO(2)-power output relationship and the difference in the magnitude of this non-linearity between incremental exercise mode and square-wave exercise mode (constant power output exercise) can be generated by introducing into the model some hypothetical factor F (group of associated factors) that accumulate(s) in time during exercise. The performed computer simulations, based on this assumption, give proper time courses of changes in VO(2) and [PCr] after an onset of work of different intensities, including the slow component in VO(2), well matching the experimental results. Moreover, if it is assumed that the exercise terminates because of fatigue when the amount/intensity of F exceed some threshold value, the model allows the generation of a proper shape of the well-known power-duration curve. This fact suggests that the phenomenon of the non-linearity of the VO(2)-power output relationship and the magnitude of this non-linearity in different modes of exercise is determined by some factor(s) responsible for muscle fatigue.

  10. Solubilization of a functionally active platelet-activating factor receptor from rabbit platelets.

    PubMed Central

    Rogers, J E; Duronio, V; Wong, S I; McNeil, M; Salari, H

    1991-01-01

    Binding of platelet-activating factor (PAF) to a specific high-affinity membrane receptor has been demonstrated in numerous cell types, but very little is known about the molecular nature of this receptor. The receptor from rabbit platelets was solubilized using CHAPS, digitonin, octyl glucoside, Nonidet P-40 or sodium cholate, either with pre-bound [3H]PAF or in the absence of ligand. We have been able to demonstrate for the first time that the receptor solubilized with CHAPS, in the absence of ligand, could retain its binding activity. It migrated as a high molecular mass complex (greater than 350 kDa) on a Bio-Gel A-0.5 m gel filtration column. Binding to solubilized receptor rapidly reached an equilibrium at room temperature, but was much slower at 0 degrees C. Scatchard plots were used to calculate the number (approx. 100 per cell) and the affinity (Kd 2.5 +/- 1.4 nM) of the solubilized receptors. These values were comparable with those obtained from whole-cell binding experiments. Competition by PAF antagonists also verified that the assay was measuring PAF receptor binding activity. The presence of a protein in the receptor complex was demonstrated by heat and trypsin inactivation of binding activity. Trypsin had no effect on binding of PAF to whole cells, but was able to decrease binding activity in solubilized receptor preparations. Attempts to demonstrate the involvement of a glycoprotein by use of various lectin columns proved unsuccessful. The latter results are consistent with findings suggesting that the binding site of the PAF receptor may not be exposed at the cell surface. PMID:1654881

  11. Auditory Power-Law Activation Avalanches Exhibit a Fundamental Computational Ground State

    NASA Astrophysics Data System (ADS)

    Stoop, Ruedi; Gomez, Florian

    2016-07-01

    The cochlea provides a biological information-processing paradigm that we are only beginning to understand in its full complexity. Our work reveals an interacting network of strongly nonlinear dynamical nodes, on which even a simple sound input triggers subnetworks of activated elements that follow power-law size statistics ("avalanches"). From dynamical systems theory, power-law size distributions relate to a fundamental ground state of biological information processing. Learning destroys these power laws. These results strongly modify the models of mammalian sound processing and provide a novel methodological perspective for understanding how the brain processes information.

  12. On the origin of power-law X-ray spectra of active galactic nuclei

    NASA Technical Reports Server (NTRS)

    Schlosman, I.; Shaham, J.; Shaviv, G.

    1984-01-01

    In the present analytical model for a power law X-ray continuum production in active galactic nuclei, the dissipation of turbulent energy flux above the accretion disk forms an optically thin transition layer with an inverted temperature gradient. The emitted thermal radiation has a power law spectrum in the 0.1-100 keV range, with a photon energy spectral index gamma of about 0.4-1.0. Thermal X-ray contribution from the layer is 5-10 percent of the total disk luminosity. The gamma value of 0.75 is suggested as a 'natural' power law index for Seyfert galaxies and QSOs.

  13. Auditory Power-Law Activation Avalanches Exhibit a Fundamental Computational Ground State.

    PubMed

    Stoop, Ruedi; Gomez, Florian

    2016-07-15

    The cochlea provides a biological information-processing paradigm that we are only beginning to understand in its full complexity. Our work reveals an interacting network of strongly nonlinear dynamical nodes, on which even a simple sound input triggers subnetworks of activated elements that follow power-law size statistics ("avalanches"). From dynamical systems theory, power-law size distributions relate to a fundamental ground state of biological information processing. Learning destroys these power laws. These results strongly modify the models of mammalian sound processing and provide a novel methodological perspective for understanding how the brain processes information.

  14. Auditory Power-Law Activation Avalanches Exhibit a Fundamental Computational Ground State.

    PubMed

    Stoop, Ruedi; Gomez, Florian

    2016-07-15

    The cochlea provides a biological information-processing paradigm that we are only beginning to understand in its full complexity. Our work reveals an interacting network of strongly nonlinear dynamical nodes, on which even a simple sound input triggers subnetworks of activated elements that follow power-law size statistics ("avalanches"). From dynamical systems theory, power-law size distributions relate to a fundamental ground state of biological information processing. Learning destroys these power laws. These results strongly modify the models of mammalian sound processing and provide a novel methodological perspective for understanding how the brain processes information. PMID:27472144

  15. Effectiveness of powered hospital bed movers for reducing physiological strain and back muscle activation.

    PubMed

    Daniell, Nathan; Merrett, Simon; Paul, Gunther

    2014-07-01

    Battery powered bed movers are becoming increasingly common within the hospital setting. The use of powered bed movers is believed to result in reduced physical efforts required by health care workers, which may be associated with a decreased risk of occupation related injuries. However, little work has been conducted assessing how powered bed movers impact on levels of physiological strain and muscle activation for the user. The muscular efforts associated with moving hospital beds using three different methods; powered StaminaLift Bed Mover (PBM1), powered Gzunda Bed Mover (PBM2) and manual pushing were measured on six male subjects. Fourteen muscles were assessed moving a weighted hospital bed along a standardized route in an Australian hospital environment. Trunk inclination and upper spine acceleration were also quantified. Powered bed movers exhibited significantly lower muscle activation levels than manual pushing for the majority of muscles. When using the PBM1, users adopted a more upright posture which was maintained while performing different tasks (e.g. turning a corner, entering a lift), while trunk inclination varied considerably for manual pushing and the PBM2. The reduction in lower back muscular activation levels may result in lower incidence of lower back injury.

  16. An Integrated Power-Efficient Active Rectifier With Offset-Controlled High Speed Comparators for Inductively Powered Applications

    PubMed Central

    Lee, Hyung-Min; Ghovanloo, Maysam

    2011-01-01

    We present an active full-wave rectifier with offset-controlled high speed comparators in standard CMOS that provides high power conversion efficiency (PCE) in high frequency (HF) range for inductively powered devices. This rectifier provides much lower dropout voltage and far better PCE compared to the passive on-chip or off-chip rectifiers. The built-in offset-control functions in the comparators compensate for both turn-on and turn-off delays in the main rectifying switches, thus maximizing the forward current delivered to the load and minimizing the back current to improve the PCE. We have fabricated this active rectifier in a 0.5-μm 3M2P standard CMOS process, occupying 0.18 mm2 of chip area. With 3.8 V peak ac input at 13.56 MHz, the rectifier provides 3.12 V dc output to a 500 Ω load, resulting in the PCE of 80.2%, which is the highest measured at this frequency. In addition, overvoltage protection (OVP) as safety measure and built-in back telemetry capabilities have been incorporated in our design using detuning and load shift keying (LSK) techniques, respectively, and tested. PMID:22174666

  17. A Low-Voltage Chopper-Stabilized Amplifier for Fetal ECG Monitoring With a 1.41 Power Efficiency Factor.

    PubMed

    Song, Shuang; Rooijakkers, Michael; Harpe, Pieter; Rabotti, Chiara; Mischi, Massimo; van Roermund, Arthur H M; Cantatore, Eugenio

    2015-04-01

    This paper presents a low-voltage current-reuse chopper-stabilized frontend amplifier for fetal ECG monitoring. The proposed amplifier allows for individual tuning of the noise in each measurement channel, minimizing the total power consumption while satisfying all application requirements. The low-voltage current reuse topology exploits power optimization in both the current and the voltage domain, exploiting multiple supply voltages (0.3, 0.6 and 1.2 V). The power management circuitry providing the different supplies is optimized for high efficiency (peak charge-pump efficiency = 90%).The low-voltage amplifier together with its power management circuitry is implemented in a standard 0.18 μm CMOS process and characterized experimentally. The amplifier core achieves both good noise efficiency factor (NEF=1.74) and power efficiency factor (PEF=1.05). Experiments show that the amplifier core can provide a noise level of 0.34 μVrms in a 0.7 to 182 Hz band, consuming 1.17 μW power. The amplifier together with its power management circuitry consumes 1.56 μW, achieving a PEF of 1.41. The amplifier is also validated with adult ECG and pre-recorded fetal ECG measurements. PMID:25879971

  18. Low-level radioactive waste from nuclear power generating stations: Characterization, classification and assessment of activated metals and waste streams

    SciTech Connect

    Thomas, V.W.; Robertson, D.E.; Thomas, C.W.

    1993-02-01

    Since the enactment of 10 CFR Part 61, additional difficult-to-measure long-lived radionuclides, not specified in Tables 1 2 of Part 61, have been identified (e.g., [sup 108m]Ag, [sup 93]Mo, [sup 36]Cl, [sup 10]Be, [sup 113m]Cd, [sup 121m]Sn, [sup 126]Sn, [sup 93m]Nb) that may be of concern in certain types of waste. These nuclides are primarily associated with activated metal and perhaps other nuclear power low-level waste (LLW) being sent to disposal facilities. The concentration of a radionuclide in waste materials is normally determined by direct measurement or by indirect calculational methods, such as using a scaling factor to relate inferred concentration of a difficult-to-measure radionuclide to another that is easily measured. The total disposal site inventory of certain difficult-to-measure radionuclides (e.g., [sup 14]C, [sup 129]I, and [sup 99]Tc) often control the total quantities of radioactive waste permitted in LLW burial facilities. Overly conservative scaling factors based on lower limits of detection (LLD), often used in the nuclear power industry to estimate these controlling nuclides, could lead to premature closure of a disposal facility. Samples of LLW (Class B and C activated metals [AM] and other waste streams) are being collected from operating nuclear power stations and analyzed for radionuclides covered in 10 CFR Part 61 and the additional difficult-to-measure radionuclides. This analysis will enhance the NRC's understanding of the distribution and projected quantities of radionuclides within AM and LLW streams from commercial nuclear power stations. This research will also provide radiological characterization of AM specimens for others to use in leach-rate and lysimeter experiments to determine nuclide releases and subsequent movement in natural soil environments.

  19. Low-level radioactive waste from nuclear power generating stations: Characterization, classification and assessment of activated metals and waste streams

    SciTech Connect

    Thomas, V.W.; Robertson, D.E.; Thomas, C.W.

    1993-02-01

    Since the enactment of 10 CFR Part 61, additional difficult-to-measure long-lived radionuclides, not specified in Tables 1 2 of Part 61, have been identified (e.g., {sup 108m}Ag, {sup 93}Mo, {sup 36}Cl, {sup 10}Be, {sup 113m}Cd, {sup 121m}Sn, {sup 126}Sn, {sup 93m}Nb) that may be of concern in certain types of waste. These nuclides are primarily associated with activated metal and perhaps other nuclear power low-level waste (LLW) being sent to disposal facilities. The concentration of a radionuclide in waste materials is normally determined by direct measurement or by indirect calculational methods, such as using a scaling factor to relate inferred concentration of a difficult-to-measure radionuclide to another that is easily measured. The total disposal site inventory of certain difficult-to-measure radionuclides (e.g., {sup 14}C, {sup 129}I, and {sup 99}Tc) often control the total quantities of radioactive waste permitted in LLW burial facilities. Overly conservative scaling factors based on lower limits of detection (LLD), often used in the nuclear power industry to estimate these controlling nuclides, could lead to premature closure of a disposal facility. Samples of LLW (Class B and C activated metals [AM] and other waste streams) are being collected from operating nuclear power stations and analyzed for radionuclides covered in 10 CFR Part 61 and the additional difficult-to-measure radionuclides. This analysis will enhance the NRC`s understanding of the distribution and projected quantities of radionuclides within AM and LLW streams from commercial nuclear power stations. This research will also provide radiological characterization of AM specimens for others to use in leach-rate and lysimeter experiments to determine nuclide releases and subsequent movement in natural soil environments.

  20. 78 FR 8493 - Foreign-Trade Zone 45-Portland, OR; Notification of Proposed Production Activity; SoloPower Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-06

    ... Activity; SoloPower Inc. (Thin Film Photovoltaic Solar Panels); Portland, OR SoloPower Inc. (SoloPower) has... production of thin film photovoltaic solar panels. Pursuant to 15 CFR 400.14(b), FTZ activity would be... film solar panels (duty-free) for the foreign status inputs noted below. Customs duties also...

  1. Factors Shaping Students' Opportunities to Engage in Argumentative Activity

    ERIC Educational Resources Information Center

    Ayalon, Michal; Even, Ruhama

    2016-01-01

    This study examines how students' opportunities to engage in argumentative activity are shaped by the teacher, the class, and the mathematical topic. It compares the argumentative activity between two classes taught by the same teacher using the same textbook and across two beginning algebra topics--investigating algebraic expressions and…

  2. Physical Activity among Older People and Related Factors

    ERIC Educational Resources Information Center

    Persson, Ann; While, Alison

    2012-01-01

    Objective: To investigate the duration, intensity and type of physical activity undertaken by people aged 60 years and over in relation to their reported levels of participation in social activities and their perceptions of their neighbourhood. Design: A cross-sectional questionnaire survey of older people attending two luncheon and eight social…

  3. Factors That Motivate Faculty to Participate in Professional Development Activities

    ERIC Educational Resources Information Center

    Lian, Xiaoyu

    2014-01-01

    Research has found that effective FPD activities improve faculty's instructional practices and pedagogy, technology skills, and knowledge and that the impact last over time (Rutz, Condon, Iverson, Manduca, & Willett, 2012). FPD activities also reduce job burnout and increase a sense of belonging and morale among faculty (Thomas, 2012).…

  4. Building gene expression signatures indicative of transcription factor activation to predict AOP modulation

    EPA Science Inventory

    Building gene expression signatures indicative of transcription factor activation to predict AOP modulation Adverse outcome pathways (AOPs) are a framework for predicting quantitative relationships between molecular initiatin...

  5. Updating Human Factors Engineering Guidelines for Conducting Safety Reviews of Nuclear Power Plants

    SciTech Connect

    O, J.M.; Higgins, J.; Stephen Fleger - NRC

    2011-09-19

    The U.S. Nuclear Regulatory Commission (NRC) reviews the human factors engineering (HFE) programs of applicants for nuclear power plant construction permits, operating licenses, standard design certifications, and combined operating licenses. The purpose of these safety reviews is to help ensure that personnel performance and reliability are appropriately supported. Detailed design review procedures and guidance for the evaluations is provided in three key documents: the Standard Review Plan (NUREG-0800), the HFE Program Review Model (NUREG-0711), and the Human-System Interface Design Review Guidelines (NUREG-0700). These documents were last revised in 2007, 2004 and 2002, respectively. The NRC is committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool. To this end, the NRC is updating its guidance to stay current with recent research on human performance, advances in HFE methods and tools, and new technology being employed in plant and control room design. This paper describes the role of HFE guidelines in the safety review process and the content of the key HFE guidelines used. Then we will present the methodology used to develop HFE guidance and update these documents, and describe the current status of the update program.

  6. Ultrahigh power factor and enhanced thermoelectric performance of individual Te/TiS2 nanocables

    NASA Astrophysics Data System (ADS)

    Li, Rui; Dui, Jingna; Fu, Yunlong; Xu, Yanling; Zhou, Shaomin

    2016-10-01

    Here, we present the successful fabrication of Te/TiS2 heterostructure nanocables with enhanced thermoelectric (TE) performance by a two-step route (a facile solvothermal approach for Te nanowires and then the Te nanowires are used as templates for the controllable growth of the Te/TiS2 nanocables), which is scalable for practical nanodevice applications. The heterostructure nanocables of different sizes can be prepared by varying the synthetic composition. Measurements of the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ) are carried out on the same nanowires over a temperature range of 2-350 K. The heterostructure nanocables show an ultrahigh power factor (S2 σ) with a maximum value of 0.58 Wm-1 K-2, which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient. The figure of merit (ZT) can reach 1.91 at room temperature from a single nanocable with a diameter of 60 nm, which is thought to contribute to the formation of the hetero-phase core/shell structure. These results are expected to open up new application possibilities in nanoscale TE devices based on individual Te/TiS2 heterostructure nanocables.

  7. Enhanced power factor via the control of structural phase transition in SnSe

    NASA Astrophysics Data System (ADS)

    Yu, Hulei; Dai, Shuai; Chen, Yue

    2016-05-01

    Tin selenide has attracted much research interest due to its unprecedentedly high thermoelectric figure of merit (ZT). For real applications, it is desirable to increase the ZT value in the lower-temperature range, as the peak ZT value currently exists near the melting point. It is shown in this paper that the structural phase transition plays an important role in boosting the ZT value of SnSe in the lower-temperature range, as the Cmcm phase is found to have a much higher power factor than the Pnma phase. Furthermore, hydrostatic pressure is predicted to be extremely effective in tuning the phase transition temperature based on ab-initio molecular dynamic simulations; a remarkable decrease in the phase transition temperature is found when a hydrostatic pressure is applied. Dynamical stabilities are investigated based on phonon calculations, providing deeper insight into the pressure effects. Accurate band structures are obtained using the modified Becke-Johnson correction, allowing reliable prediction of the electrical transport properties. The effects of hydrostatic pressure on the thermal transport properties are also discussed. Hydrostatic pressure is shown to be efficient in manipulating the transport properties via the control of phase transition temperature in SnSe, paving a new path for enhancing its thermoelectric efficiency.

  8. Enhanced power factor via the control of structural phase transition in SnSe.

    PubMed

    Yu, Hulei; Dai, Shuai; Chen, Yue

    2016-01-01

    Tin selenide has attracted much research interest due to its unprecedentedly high thermoelectric figure of merit (ZT). For real applications, it is desirable to increase the ZT value in the lower-temperature range, as the peak ZT value currently exists near the melting point. It is shown in this paper that the structural phase transition plays an important role in boosting the ZT value of SnSe in the lower-temperature range, as the Cmcm phase is found to have a much higher power factor than the Pnma phase. Furthermore, hydrostatic pressure is predicted to be extremely effective in tuning the phase transition temperature based on ab-initio molecular dynamic simulations; a remarkable decrease in the phase transition temperature is found when a hydrostatic pressure is applied. Dynamical stabilities are investigated based on phonon calculations, providing deeper insight into the pressure effects. Accurate band structures are obtained using the modified Becke-Johnson correction, allowing reliable prediction of the electrical transport properties. The effects of hydrostatic pressure on the thermal transport properties are also discussed. Hydrostatic pressure is shown to be efficient in manipulating the transport properties via the control of phase transition temperature in SnSe, paving a new path for enhancing its thermoelectric efficiency. PMID:27193260

  9. Enhanced power factor via the control of structural phase transition in SnSe

    PubMed Central

    Yu, Hulei; Dai, Shuai; Chen, Yue

    2016-01-01

    Tin selenide has attracted much research interest due to its unprecedentedly high thermoelectric figure of merit (ZT). For real applications, it is desirable to increase the ZT value in the lower-temperature range, as the peak ZT value currently exists near the melting point. It is shown in this paper that the structural phase transition plays an important role in boosting the ZT value of SnSe in the lower-temperature range, as the Cmcm phase is found to have a much higher power factor than the Pnma phase. Furthermore, hydrostatic pressure is predicted to be extremely effective in tuning the phase transition temperature based on ab-initio molecular dynamic simulations; a remarkable decrease in the phase transition temperature is found when a hydrostatic pressure is applied. Dynamical stabilities are investigated based on phonon calculations, providing deeper insight into the pressure effects. Accurate band structures are obtained using the modified Becke-Johnson correction, allowing reliable prediction of the electrical transport properties. The effects of hydrostatic pressure on the thermal transport properties are also discussed. Hydrostatic pressure is shown to be efficient in manipulating the transport properties via the control of phase transition temperature in SnSe, paving a new path for enhancing its thermoelectric efficiency. PMID:27193260

  10. Ultrahigh power factor and enhanced thermoelectric performance of individual Te/TiS2 nanocables.

    PubMed

    Li, Rui; Dui, Jingna; Fu, Yunlong; Xu, Yanling; Zhou, Shaomin

    2016-10-14

    Here, we present the successful fabrication of Te/TiS2 heterostructure nanocables with enhanced thermoelectric (TE) performance by a two-step route (a facile solvothermal approach for Te nanowires and then the Te nanowires are used as templates for the controllable growth of the Te/TiS2 nanocables), which is scalable for practical nanodevice applications. The heterostructure nanocables of different sizes can be prepared by varying the synthetic composition. Measurements of the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ) are carried out on the same nanowires over a temperature range of 2-350 K. The heterostructure nanocables show an ultrahigh power factor (S(2) σ) with a maximum value of 0.58 Wm(-1) K(-2), which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient. The figure of merit (ZT) can reach 1.91 at room temperature from a single nanocable with a diameter of 60 nm, which is thought to contribute to the formation of the hetero-phase core/shell structure. These results are expected to open up new application possibilities in nanoscale TE devices based on individual Te/TiS2 heterostructure nanocables. PMID:27595302

  11. Ultrahigh power factor and enhanced thermoelectric performance of individual Te/TiS2 nanocables.

    PubMed

    Li, Rui; Dui, Jingna; Fu, Yunlong; Xu, Yanling; Zhou, Shaomin

    2016-10-14

    Here, we present the successful fabrication of Te/TiS2 heterostructure nanocables with enhanced thermoelectric (TE) performance by a two-step route (a facile solvothermal approach for Te nanowires and then the Te nanowires are used as templates for the controllable growth of the Te/TiS2 nanocables), which is scalable for practical nanodevice applications. The heterostructure nanocables of different sizes can be prepared by varying the synthetic composition. Measurements of the Seebeck coefficient (S), electrical conductivity (σ), and thermal conductivity (κ) are carried out on the same nanowires over a temperature range of 2-350 K. The heterostructure nanocables show an ultrahigh power factor (S(2) σ) with a maximum value of 0.58 Wm(-1) K(-2), which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient. The figure of merit (ZT) can reach 1.91 at room temperature from a single nanocable with a diameter of 60 nm, which is thought to contribute to the formation of the hetero-phase core/shell structure. These results are expected to open up new application possibilities in nanoscale TE devices based on individual Te/TiS2 heterostructure nanocables.

  12. Biochemical characterization of a factor X activator protein purified from Walterinnesia aegyptia venom.

    PubMed

    Khan, Sami U; Al-Saleh, Saad S

    2015-10-01

    Factor X of blood coagulation cascade can be activated by both intrinsic and extrinsic activating complex, trypsin and some kind of snake venom. A factor X activator protein is reported in Elapidae snake venom. The aim of this study was to evaluate biochemical properties of factor X activator protein because of its prospective application in biochemical research and therapeutics. Crude venom was fractionated on a HPLC system Gold 126/1667 using a combination of Protein PAK 125 and Protein PAK 60 Columns. Molecular weight was determined using SDS-PAGE. Walterinnesia aegyptia venom was fractionated into several protein peaks, but procoagulant and factor X activation activity coexisted into peak no.6. It appeared as single band on native PAGE and molecular weight was 60,000 ± 3. Purified up to 37-fold over crude venom. It shortened recalcification time, effect was dose-dependent and strictly Ca(2++)-dependent. Factor X activator seems to be able to activate factor X specifically because it showed no activation activity on human prothrombin, plasminogen, or protein C. It did not hydrolyze factor Xa substrate S-2222, thrombin substrate S-2238, plasmin substrate S-2251 or S-2302 and kalikrein substrate S-2266. It did not hydrolyze synthetic ester benzoyl arginine ethyl ester. Procoagulant activity was completely inhibited by irreversible serine protease inhibitors phenylmethylsulphonyl fluoride and N-p-tosylphenylalanine chloromethyl ketone. This study illustrates that factor X activator from W. aegyptia is though different in many aspects from factor X activators of Viperidae and Crotalidae venoms, but shows several properties identical to factor X activators from Elapidae venoms. PMID:26407136

  13. Impact of nonsynonymous mutations of factor X on the functions of factor X and anticoagulant activity of edoxaban.

    PubMed

    Noguchi, Kengo; Morishima, Yoshiyuki; Takahashi, Shinichi; Ishihara, Hiroaki; Shibano, Toshiro; Murata, Mitsuru

    2015-03-01

    Edoxaban is an oral direct factor Xa (FXa) inhibitor and its efficacy as an oral anticoagulant is less subject to drug-food and drug-drug interaction than existing vitamin K antagonists. Although this profile of edoxaban suggests it is well suited for clinical use, it is not clear whether genetic variations of factor X influence the activity of edoxaban. Our aim was to investigate a possible impact of single-nucleotide polymorphisms (SNPs) in the factor X gene on the functions of factor X and the activity of edoxaban. Two nonsynonymous SNPs within mature factor X, Ala152Thr and Gly192Arg, were selected as possible candidates that might affect the functions of FXa and the activity of edoxaban. We measured catalytic activities of wild type and mutant FXas in a chromogenic assay using S-2222 and coagulation times including prothrombin time (PT) and activated partial thrombin time (aPTT) of plasma-containing recombinant FXs in the presence and absence of edoxaban. Michaelis-Menten kinetic parameters of FXas, Km and Vmax values, PT and aPTT were not influenced by either mutation indicating these mutations do not affect the FXa catalytic and coagulation activities. The Ki values of edoxaban for the FXas and the concentrations of edoxaban required to double PT and aPTT were not different between wild type and mutated FXas indicating that both mutations have little impact on the activity of edoxaban. In conclusion, these data suggest that edoxaban has little interpatient variability stemming from SNPs in the factor X gene. PMID:24911450

  14. FACTORS AFFECTING TIME-ACTIVITY BUDGETS OF BUFFLEHEAD WINTERING IN NARRAGANSETT, BAY, RI

    EPA Science Inventory

    Daily activities of wintering waterfowl can be influenced by the physical environment and by habitat factors such as prey abundance and availability. We examined variability in diurnal activity budgets of Bufflehead (Bucephala albeola) wintering at seven locations within Narragan...

  15. Application considerations and compensation characteristics of shunt active and series active filters in power systems

    SciTech Connect

    Peng, Fang Zheng; Lai, Jih-Sheng

    1996-10-01

    This paper characterizes typical nonlinear loads into two types of harmonic sources -harmonic current source and harmonic voltage source, which produce highly distorted currents and voltages, respectively. The conventional approach of active harmonic compensation has been the parallel type or `shunt active filter.` It is shown in this paper that the shunt active filter is effective only to harmonic current sources but not to harmonic voltage sources. On the other hand, the active filter connected in series with the system or `series active filter` is very effective in suppression of the harmonic voltage sources. General compensation characteristics of shunt active filters and series active filters are given analytically. The features, required operation conditions, and application considerations of both filters are described analytically and demonstrated experimentally.

  16. ANALYSIS OF DISCRIMINATING FACTORS IN HUMAN ACTIVITIES THAT AFFECT EXPOSURE

    EPA Science Inventory

    Accurately modeling exposure to particulate matter (PM) and other pollutants ultimately involves the utilization of human location-activity databases to assist in understanding the potential variability of microenvironmental exposures. This paper critically considers and stati...

  17. The Role of Platelet-Activating Factor in Chronic Inflammation, Immune Activation, and Comorbidities Associated with HIV Infection

    PubMed Central

    Kelesidis, Theodoros; Papakonstantinou, Vasiliki; Detopoulou, Paraskevi; Fragopoulou, Elizabeth; Chini, Maria; Lazanas, Marios C.; Antonopoulou, Smaragdi

    2016-01-01

    With the advent of highly effective antiretroviral therapy, cardiovascular disease has become an important cause of morbidity and mortality among people with treated HIV-1, but the pathogenesis is unclear. Platelet-activating factor is a potent lipid mediator of inflammation that has immunomodulatory effects and a pivotal role in the pathogenesis of inflammatory disorders and cardiovascular disease. Limited scientific evidence suggests that the platelet-activating factor pathway may be a mechanistic link between HIV-1 infection, systemic inflammation, and immune activation that contribute to pathogenesis of chronic HIV-related comorbidities, including cardiovascular disease and HIV-associated neurocognitive disorders. In this review, we examine the mechanisms by which the cross-talk between HIV-1, immune dysregulation, inflammation, and perturbations in the platelet-activating factor pathway may directly affect HIV-1 immunopathogenesis. Understanding the role of platelet-activating factor in HIV-1 infection may pave the way for further studies to explore therapeutic interventions, such as diet, that can modify platelet-activating factor activity and use of platelet-activating factor inhibitors that might improve the prognosis of HIV-1 infected patients. PMID:26616844

  18. Influence of single nucleotide polymorphisms in factor VIII and von Willebrand factor genes on plasma factor VIII activity: the ARIC Study.

    PubMed

    Campos, Marco; Buchanan, Ashley; Yu, Fuli; Barbalic, Maja; Xiao, Yang; Chambless, Lloyd E; Wu, Kenneth K; Folsom, Aaron R; Boerwinkle, Eric; Dong, Jing-fei

    2012-02-23

    Factor VIII (FVIII) functions as a cofactor for factor IXa in the contact coagulation pathway and circulates in a protective complex with von Willebrand factor (VWF). Plasma FVIII activity is strongly influenced by environmental and genetic factors through VWF-dependent and -independent mechanisms. Single nucleotide polymorphisms (SNPs) of the coding and promoter sequence in the FVIII gene have been extensively studied for effects on FVIII synthesis, secretion, and activity, but impacts of non-disease-causing intronic SNPs remain largely unknown. We analyzed FVIII SNPs and FVIII activity in 10,434 healthy Americans of European (EA) or African (AA) descent in the Atherosclerosis Risk in Communities (ARIC) study. Among covariates, age, race, diabetes, and ABO contributed 2.2%, 3.5%, 4%, and 10.7% to FVIII intersubject variation, respectively. Four intronic FVIII SNPs associated with FVIII activity and 8 with FVIII-VWF ratio in a sex- and race-dependent manner. The FVIII haplotypes AT and GCTTTT also associated with FVIII activity. Seven VWF SNPs were associated with FVIII activity in EA subjects, but no FVIII SNPs were associated with VWF Ag. These data demonstrate that intronic SNPs could directly or indirectly influence intersubject variation of FVIII activity. Further investigation may reveal novel mechanisms of regulating FVIII expression and activity. PMID:22219226

  19. ARE RADIO ACTIVE GALACTIC NUCLEI POWERED BY ACCRETION OR BLACK HOLE SPIN?

    SciTech Connect

    McNamara, B. R.; Rohanizadegan, Mina; Nulsen, P. E. J.

    2011-01-20

    We compare accretion and black hole spin as potential energy sources for outbursts from active galactic nuclei (AGNs) in brightest cluster galaxies (BCGs). Based on our adopted spin model, we find that the distribution of AGN power estimated from X-ray cavities is consistent with a broad range of both spin parameters and accretion rates. Sufficient quantities of molecular gas are available in most BCGs to power their AGNs by accretion alone. However, we find no correlation between AGN power and molecular gas mass over the range of jet power considered here. For a given AGN power, the BCG's gas mass and accretion efficiency, defined as the fraction of the available cold molecular gas that is required to power the AGN, both vary by more than two orders of magnitude. Most of the molecular gas in BCGs is apparently consumed by star formation or is driven out of the nucleus by the AGN before it reaches the nuclear black hole. Bondi accretion from hot atmospheres is generally unable to fuel powerful AGNs, unless their black holes are more massive than their bulge luminosities imply. We identify several powerful AGNs that reside in relatively gas-poor galaxies, indicating an unusually efficient mode of accretion, or that their AGNs are powered by another mechanism. If these systems are powered primarily by black hole spin rather than by accretion, spin must also be tapped efficiently in some systems, i.e., P{sub jet}> M-dot c{sup 2}, or their black hole masses must be substantially larger than the values implied by their bulge luminosities. We constrain the (model-dependent) accretion rate at the transition from radiatively inefficient to radiatively efficient accretion flows to be a few percent of the Eddington rate, a value that is consistent with other estimates.

  20. Structure activity relationship of phenolic diterpenes from Salvia officinalis as activators of the nuclear factor E2-related factor 2 pathway.

    PubMed

    Fischedick, Justin T; Standiford, Miranda; Johnson, Delinda A; Johnson, Jeffrey A

    2013-05-01

    Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor known to activate cytoprotective genes which may be useful in the treatment of neurodegenerative disease. In order to better understand the structure activity relationship of phenolic diterpenes from Salvia officinalis L., we isolated carnosic acid, carnosol, epirosmanol, rosmanol, 12-methoxy-carnosic acid, sageone, and carnosaldehyde using polyamide column, centrifugal partition chromatography, and semi-preparative high performance liquid chromatography. Isolated compounds were screened in vitro for their ability to active the Nrf2 and general cellular toxicity using mouse primary cortical cultures. All compounds except 12-methoxy-carnosic acid were able to activate the antioxidant response element. Furthermore both carnosol and carnoasldehyde were able to induce Nrf2-dependent gene expression as well as protect mouse primary cortical neuronal cultures from H(2)O(2) induced cell death.

  1. Factors influencing sexual activity after prostatectomy: a prospective study.

    PubMed

    Zohar, J; Meiraz, D; Maoz, B; Durst, N

    1976-09-01

    Between 16 and 30 per cent of all prostatectomy patients become impotent after an operation for benign prostatic hyperplasia. Since the surgical technique does not seem to be the factor responsible for such a serious problem, more accentuated by the fact that this operation is becoming increasingly frequent with the increase in life expectancy, an assessment of 15 patients before and after prostatectomy is presented. With a statistical analysis of a structured interview (including a mini-Minnesota Multiphasic Personality Inventory test before and after the operation) 3 main differentiating factors emerged between the potent and the impotent group: 1) the level of anxiety exhibited by the patient, 2) whether the patients received an explanation about the surgery and its outcome prior to the operation and 3) the patient's general satisfaction with life. PMID:957502

  2. Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography

    PubMed Central

    Mousavi Hosseini, Kamran; Nasiri, Saleh

    2015-01-01

    Background: Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. Methods: PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Results: Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). Results of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). Conclusion: It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII. PMID:26034723

  3. Dietary Factors in the Modulation of Inflammatory Bowel Disease Activity

    PubMed Central

    Shah, Shinil

    2007-01-01

    Context As patients look to complementary therapies for management of their diseases, it is important that the physician know the effectiveness and/or lack of effectiveness of a variety of dietary approaches/interventions. Although the pathogenesis of the inflammatory bowel diseases (ulcerative colitis and Crohn's disease) is not fully understood, many suspect that diet and various dietary factors may play a modulating role in the disease process. Evidence Acquisition The purpose of this article is to present some of what is known about various dietary/nutritional factors in inflammatory bowel disease, with inclusion of evidence from various studies regarding their putative effect. MedLINE was searched (1965-present) using combinations of the following search terms: diet, inflammatory bowel disease, Crohn's disease, and ulcerative colitis. Additionally, references of the articles obtained were searched to identify further potential sources of information. Evidence Synthesis While much information is available regarding various dietary interventions/supplements in regard to inflammatory bowel disease, the lack of controlled trials limits broad applicability. Probiotics are one of the few interventions with promising results and controlled trials. Conclusion While there are many potential and promising dietary factors that may play a role in the modulation of inflammatory bowel disease, it is prudent to await further controlled studies before broad application/physician recommendation in the noted patient population. PMID:17435660

  4. Insights into the Interferon Regulatory Factor Activation from the Crystal Structure of Dimeric IRF5

    SciTech Connect

    Chen, W.; Lam, S; Srinath, H; Jiang, Z; Correia, J; Schiffer, C; Fitzgerald, K; Lin, K; Royer, Jr., W

    2008-01-01

    The interferon regulatory factors (IRFs) are involved in the innate immune response and are activated by phosphorylation. The structure of a pseudophosphorylated IRF5 activation domain now reveals structural changes in the activated form that would turn an autoinhibitory region into a dimerization interface. In vivo analysis supports the relevance of such a dimer to transcriptional activation.

  5. Fast Power Line Detection and Localization Using Steerable Filter for Active Uav Guidance

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Mejias, L.; Li, Z.

    2012-08-01

    In this paper we present a fast power line detection and localisation algorithm as well as propose a high-level guidance architecture for active vision-based Unmanned Aerial Vehicle (UAV) guidance. The detection stage is based on steerable filters for edge ridge detection, followed by a line fitting algorithm to refine candidate power lines in images. The guidance architecture assumes an UAV with an onboard Gimbal camera. We first control the position of the Gimbal such that the power line is in the field of view of the camera. Then its pose is used to generate the appropriate control commands such that the aircraft moves and flies above the lines. We present initial experimental results for the detection stage which shows that the proposed algorithm outperforms two state-of-the-art line detection algorithms for power line detection from aerial imagery.

  6. A new dynamic voltage restorer with separating active and reactive power circuit design

    NASA Astrophysics Data System (ADS)

    Pai, Fu-Sheng

    2015-05-01

    Conventional dynamic voltage restorers (DVRs) install parallel battery and capacitor sets at the DC bus to supply the required power for voltage sag compensation. However, the reactive power output of a DVR may increase the ripple voltage at the inner DC bus, possibly resulting in a higher operating temperature of the battery and thus decreased battery life. This paper proposes a DVR system that uses a cascade power module to effectively compensate voltage sag. By separating the active and reactive compensation powers, the proposed DVR provides a lower ripple DC link for extending battery life and offers a flexible way to design the capacitor bank. To confirm the effectiveness of the proposed design, theoretical analysis and experimental validation were conducted under various scenarios. Test results confirm the feasibility and practicality of the proposed method.

  7. Surface-mediated enzymatic reactions: simulations of tissue factor activation of factor X on a lipid surface.

    PubMed Central

    Gentry, R; Ye, L; Nemerson, Y

    1995-01-01

    Blood coagulation proceeds via reactions in which zymogen coagulation factors are activated to proteases. An essential step is the activation of factor X by a complex of tissue factor and factor VIIa. This complex usually is studied using phospholipid vesicles into which tissue factor is inserted. Because factor X exists free in solution and bound to the lipid-surface, it is difficult to establish experimentally the kinetic contribution of surfaces. We therefore developed a stochastic model to simulate such reactions and generate initial velocity data from which Michaelis-Menten parameters are estimated. Simulated Km values decrease slightly when substrate binding to lipid is increased and by a factor of four when the rates of surface diffusion are increased to that of fluid phase-diffusion. Simulations with various size planar surfaces established an enzyme capture radius of 32-64 nm. Simulations with different modes of enzyme-substrate complex assembly show that if the true substrate is lipid-bound, under certain conditions, the true Kcat is not measured; rather, the product "leaving rate" from the complex is the rate-limiting step that is measured as substrate is taken to infinity. This model is applicable to any surface-bound enzyme reaction. Images FIGURE 1 FIGURE 2 FIGURE 3 PMID:8527649

  8. Transcription factors of Lotus: regulation of isoflavonoid biosynthesis requires coordinated changes in transcription factor activity.

    PubMed

    Shelton, Dale; Stranne, Maria; Mikkelsen, Lisbeth; Pakseresht, Nima; Welham, Tracey; Hiraka, Hideki; Tabata, Satoshi; Sato, Shusei; Paquette, Suzanne; Wang, Trevor L; Martin, Cathie; Bailey, Paul

    2012-06-01

    Isoflavonoids are a class of phenylpropanoids made by legumes, and consumption of dietary isoflavonoids confers benefits to human health. Our aim is to understand the regulation of isoflavonoid biosynthesis. Many studies have shown the importance of transcription factors in regulating the transcription of one or more genes encoding enzymes in phenylpropanoid metabolism. In this study, we coupled bioinformatics and coexpression analysis to identify candidate genes encoding transcription factors involved in regulating isoflavonoid biosynthesis in Lotus (Lotus japonicus). Genes encoding proteins belonging to 39 of the main transcription factor families were examined by microarray analysis of RNA from leaf tissue that had been elicited with glutathione. Phylogenetic analyses of each transcription factor family were used to identify subgroups of proteins that were specific to L. japonicus or closely related to known regulators of the phenylpropanoid pathway in other species. R2R3MYB subgroup 2 genes showed increased expression after treatment with glutathione. One member of this subgroup, LjMYB14, was constitutively overexpressed in L. japonicus and induced the expression of at least 12 genes that encoded enzymes in the general phenylpropanoid and isoflavonoid pathways. A distinct set of six R2R3MYB subgroup 2-like genes was identified. We suggest that these subgroup 2 sister group proteins and those belonging to the main subgroup 2 have roles in inducing isoflavonoid biosynthesis. The induction of isoflavonoid production in L. japonicus also involves the coordinated down-regulation of competing biosynthetic pathways by changing the expression of other transcription factors. PMID:22529285

  9. Low-power laser irradiation enhance macrophage phagocytic capacity through Src activation

    NASA Astrophysics Data System (ADS)

    Wu, Shengnan; Zhou, Feifan; Xing, Da

    2012-03-01

    Phagocytosis and subsequent degradation of pathogens by macrophages play a pivotal role in host innate immunity in mammals. Laser irradiation has been found to produce photobiological effects with evidence of interference with organic functions. In this study, we focused our attention on the effects of He-Ne laser on the phagocytic activity of macrophages, the regulation mechanism of phagocytosis was also discussed. Our results indicated that Low-power laser irradiation can enhance the phagocytosis of macrophage through activation of Src.

  10. Shunt hybrid active power filter under nonideal voltage based on fuzzy logic controller

    NASA Astrophysics Data System (ADS)

    Dey, Papan; Mekhilef, Saad

    2016-09-01

    In this paper, a synchronous reference frame (SRF) method based on a modified phase lock loop (PLL) circuit is developed for a three-phase four-wire shunt hybrid active power filter (APF). Its performance is analysed under unbalanced grid conditions. The dominant lower order harmonics as well as reactive power can be compensated by the passive elements, whereas the active part mitigates the remaining distortions and improves the power quality. As different control methods show contradictory performance, fuzzy logic controller is considered here for DC-link voltage regulation of the inverter. Extensive simulations of the proposed technique are carried out in a MATLAB-SIMULINK environment. A laboratory prototype has been built on dSPACE1104 platform to verify the feasibility of the suggested SHAPF controller. The simulation and experimental results validate the effectiveness of the proposed technique.

  11. Mapping neural circuits with activity-dependent nuclear import of a transcription factor.

    PubMed

    Masuyama, Kaoru; Zhang, Yi; Rao, Yi; Wang, Jing W

    2012-03-01

    Abstract: Nuclear factor of activated T cells (NFAT) is a calcium-responsive transcription factor. We describe here an NFAT-based neural tracing method-CaLexA (calcium-dependent nuclear import of LexA)-for labeling active neurons in behaving animals. In this system, sustained neural activity induces nuclear import of the chimeric transcription factor LexA-VP16-NFAT, which in turn drives green fluorescent protein (GFP) reporter expression only in active neurons. We tested this system in Drosophila and found that volatile sex pheromones excite specific neurons in the olfactory circuit. Furthermore, complex courtship behavior associated with multi-modal sensory inputs activated neurons in the ventral nerve cord. This method harnessing the mechanism of activity-dependent nuclear import of a transcription factor can be used to identify active neurons in specific neuronal population in behaving animals. PMID:22236090

  12. T & I, Power Mechanics. Kit No. 35. Instructor's Manual [and] Student Learning Activity Guide.

    ERIC Educational Resources Information Center

    Underwood, Earl

    An instructor's manual and student activity guide on power mechanics are provided in this set of prevocational education materials which focuses on the vocational area of trade and industry. (This set of materials is one of ninety-two prevocational education sets arranged around a cluster of seven vocational offerings: agriculture, home economics,…

  13. Power Perceptions and Negotiations in a Cross-National Email Writing Activity

    ERIC Educational Resources Information Center

    Liu, Yichun

    2011-01-01

    The present study investigates EFL students' perceptions of power differentials and their negotiation strategies when communicating with native English-speaking students via emails. The study involved 28 Taiwanese and American undergraduates who participated in a semester-long cross-national email writing activity. Findings show that students in…

  14. Star Power: Providing for the Gifted & Talented. Module 5. Enrichment Activities for the Gifted/Talented.

    ERIC Educational Resources Information Center

    Mallis, Jackie; Gilman, Sharlene

    The document presents Module 5, enrichment activities for the gifted/talented, of the Star Power modules developed for school personnel who have an interest in or a need to explore the area of gifted and talented education. It is explained in an introductory section that the modules can be used for independent study, for small group interaction,…

  15. Power spectral analysis of autonomic nervous activity in spontaneously hypertensive rats.

    PubMed

    Ju, K; Kubo, T

    1997-01-01

    We studied power spectral analysis of heart rate variability (HRV) in control spontaneously hypertensive rats (SHR) and tourmaline hydroxyl negative ion-treated SHR groups. The power spectrum of HRV in SHR groups was composed of two frequency components; low frequency (LF, 0.005 approximately 1.0 Hz) and high frequency (HF, 1.0 approximately 2.0 Hz) components. The low frequency power (LFP) of HRV spectrum, which indicates sympathetic nervous activity, in negative air ion-treated SHR group was significantly (p < 0.01) smaller than in control SHR group. And also we obtained that the high frequency power (HFP) showing parasympathetic nervous activity in negative air ion-treated SHR group was significantly (p < 0.01) higher than in control SHR group. It could be concluded that hydroxyl negative air ions generated by tourmaline ionizer system decreased the elevated blood pressure, and control the sympathetic nervous activity and the parasympathetic nervous activity in SHR having the elevated blood pressure. PMID:9731382

  16. Power spectral analysis of autonomic nervous activity in spontaneously hypertensive rats.

    PubMed

    Ju, K; Kubo, T

    1997-01-01

    We studied power spectral analysis of heart rate variability (HRV) in control spontaneously hypertensive rats (SHR) and tourmaline hydroxyl negative ion-treated SHR groups. The power spectrum of HRV in SHR groups was composed of two frequency components; low frequency (LF, 0.005 approximately 1.0 Hz) and high frequency (HF, 1.0 approximately 2.0 Hz) components. The low frequency power (LFP) of HRV spectrum, which indicates sympathetic nervous activity, in negative air ion-treated SHR group was significantly (p < 0.01) smaller than in control SHR group. And also we obtained that the high frequency power (HFP) showing parasympathetic nervous activity in negative air ion-treated SHR group was significantly (p < 0.01) higher than in control SHR group. It could be concluded that hydroxyl negative air ions generated by tourmaline ionizer system decreased the elevated blood pressure, and control the sympathetic nervous activity and the parasympathetic nervous activity in SHR having the elevated blood pressure.

  17. Factors Associated with Physical Activity Literacy among Foster Parents

    ERIC Educational Resources Information Center

    Dominick, Gregory M.; Friedman, Daniela B.; Saunders, Ruth P.; Hussey, Jim R.; Watkins, Ken W.; W.

    2012-01-01

    Objectives: To explore associations between physical activity (PA) literacy and psychosocial constructs for providing instrumental social support for youth PA. Methods: Ninety-one foster parents completed surveys assessing PA literacy (overall and specific), perceptions of child PA, coordination, PA enjoyment, psychosocial variables:…

  18. Factors Influencing Physical Activity among Postpartum Iranian Women

    ERIC Educational Resources Information Center

    Roozbahani, Nasrin; Ghofranipour, Fazlollah; Eftekhar Ardabili, Hassan; Hajizadeh, Ebrahim

    2014-01-01

    Background: Postpartum women are a population at risk for sedentary living. Physical activity (PA) prior to pregnancy may be effective in predicting similar behaviour in the postpartum period. Objective: To test a composite version of the extended transtheoretical model (TTM) by adding "past behaviour" in order to predict PA behaviour…

  19. Role of Individual and School Factors in Physical Activity Patterns of Secondary-Level Spanish Students

    ERIC Educational Resources Information Center

    Juan, Francisco Ruiz; Bengoechea, Enrique Garcia; Montes, Maria Elena Garcia; Bush, Paula Louise

    2010-01-01

    Background: While the importance of individual and school factors as correlates of overall youth physical activity has been demonstrated by previous research, less is known about the relationship of these factors with specific patterns of physical activity during adolescence. Thus, the purpose of this study was to examine the association of…

  20. Effects of geomagnetic activity and atmospheric power variations on quantitative measures of brain activity: Replication of the Azerbaijani studies

    NASA Astrophysics Data System (ADS)

    Mulligan, Bryce P.; Hunter, Mathew D.; Persinger, Michael A.

    2010-04-01

    This study replicates and extends the observations by Babayev and Allahveriyeva that changes in right hemispheric electroencephalographic activity are correlated with increases in geomagnetic activity. During the geomagnetically quiet interface between solar cycle 23 and 24 quantitative electroencephalographic (QEEG) measurements were completed for normal young adults in three separate experiments involving about 120 samples over 1.5 years. The most consistent, moderate strength correlations occurred for the changes in power within the gamma and theta ranges over the right frontal lobe. Real-time measures of atmospheric power obtained from polar orbiting satellites showed similar effects. The preferential involvement of the right frontal lobe and the regions subject to its inhibition with environmental energetic changes are consistent with the behavioural correlations historically associated with these conditions. They include increased incidence of emotional lability, erroneous reconstruction of experiences, social confrontations, and unusual perceptions.

  1. Symbiotic Activity of Pea (Pisum sativum) after Application of Nod Factors under Field Conditions

    PubMed Central

    Siczek, Anna; Lipiec, Jerzy; Wielbo, Jerzy; Kidaj, Dominika; Szarlip, Paweł

    2014-01-01

    Growth and symbiotic activity of legumes are mediated by Nod factors (LCO, lipo-chitooligosaccharides). To assess the effects of application of Nod factors on symbiotic activity and yield of pea, a two-year field experiment was conducted on a Haplic Luvisol developed from loess. Nod factors were isolated from Rhizobium leguminosarum bv. viciae strain GR09. Pea seeds were treated with the Nod factors (10−11 M) or water (control) before planting. Symbiotic activity was evaluated by measurements of nitrogenase activity (acetylene reduction assay), nodule number and mass, and top growth by shoot mass, leaf area, and seed and protein yield. Nod factors generally improved pea yield and nitrogenase activity in the relatively dry growing season 2012, but not in the wet growing season in 2013 due to different weather conditions. PMID:24786094

  2. Platelet-Derived Short-Chain Polyphosphates Enhance the Inactivation of Tissue Factor Pathway Inhibitor by Activated Coagulation Factor XI

    PubMed Central

    Puy, Cristina; Tucker, Erik I.; Ivanov, Ivan S.; Gailani, David; Smith, Stephanie A.; Morrissey, James H.; Gruber, András; McCarty, Owen J. T.

    2016-01-01

    Introduction Factor (F) XI supports both normal human hemostasis and pathological thrombosis. Activated FXI (FXIa) promotes thrombin generation by enzymatic activation of FXI, FIX, FX, and FV, and inactivation of alpha tissue factor pathway inhibitor (TFPIα), in vitro. Some of these reactions are now known to be enhanced by short-chain polyphosphates (SCP) derived from activated platelets. These SCPs act as a cofactor for the activation of FXI and FV by thrombin and FXIa, respectively. Since SCPs have been shown to inhibit the anticoagulant function of TFPIα, we herein investigated whether SCPs could serve as cofactors for the proteolytic inactivation of TFPIα by FXIa, further promoting the efficiency of the extrinsic pathway of coagulation to generate thrombin. Methods and Results Purified soluble SCP was prepared by size-fractionation of sodium polyphosphate. TFPIα proteolysis was analyzed by western blot. TFPIα activity was measured as inhibition of FX activation and activity in coagulation and chromogenic assays. SCPs significantly accelerated the rate of inactivation of TFPIα by FXIa in both purified systems and in recalcified plasma. Moreover, platelet-derived SCP accelerated the rate of inactivation of platelet-derived TFPIα by FXIa. TFPIα activity was not affected by SCP in recalcified FXI-depleted plasma. Conclusions Our data suggest that SCP is a cofactor for TFPIα inactivation by FXIa, thus, expanding the range of hemostatic FXIa substrates that may be affected by the cofactor functions of platelet-derived SCP. PMID:27764259

  3. Factors affecting the adsorption of xenon on activated carbon

    SciTech Connect

    Underhill, D.W.; DiCello, D.C.; Scaglia, L.A.; Watson, J.A.

    1986-08-01

    The presence of water vapor was found to interfere strongly with the dynamic adsorption of /sup 133/Xe on coconut-base activated charcoal. The percent loss in the xenon adsorption coefficient was similar to values reported earlier for the adsorption of krypton on humidified charcoal. Attempts to increase the adsorption of xenon by (a) using a petroleum-based adsorbent with an extremely high surface area and (b) by impregnation of the adsorbent with iodine were not successful.

  4. The Drosophila Transcription Factors Tinman and Pannier Activate and Collaborate with Myocyte Enhancer Factor-2 to Promote Heart Cell Fate

    PubMed Central

    Lovato, TyAnna L.; Sensibaugh, Cheryl A.; Swingle, Kirstie L.; Martinez, Melody M.; Cripps, Richard M.

    2015-01-01

    Expression of the MADS domain transcription factor Myocyte Enhancer Factor 2 (MEF2) is regulated by numerous and overlapping enhancers which tightly control its transcription in the mesoderm. To understand how Mef2 expression is controlled in the heart, we identified a late stage Mef2 cardiac enhancer that is active in all heart cells beginning at stage 14 of embryonic development. This enhancer is regulated by the NK-homeodomain transcription factor Tinman, and the GATA transcription factor Pannier through both direct and indirect interactions with the enhancer. Since Tinman, Pannier and MEF2 are evolutionarily conserved from Drosophila to vertebrates, and since their vertebrate homologs can convert mouse fibroblast cells to cardiomyocytes in different activator cocktails, we tested whether over-expression of these three factors in vivo could ectopically activate known cardiac marker genes. We found that mesodermal over-expression of Tinman and Pannier resulted in approximately 20% of embryos with ectopic Hand and Sulphonylurea receptor (Sur) expression. By adding MEF2 alongside Tinman and Pannier, a dramatic expansion in the expression of Hand and Sur was observed in almost all embryos analyzed. Two additional cardiac markers were also expanded in their expression. Our results demonstrate the ability to initiate ectopic cardiac fate in vivo by the combination of only three members of the conserved Drosophila cardiac transcription network, and provide an opportunity for this genetic model system to be used to dissect the mechanisms of cardiac specification. PMID:26225919

  5. Stimulation of protein phosphatase activity by insulin and growth factors in 3T3 cells

    SciTech Connect

    Chan, C.P.; McNall, S.J.; Krebs, E.G.; Fischer, E.H. )

    1988-09-01

    Incubation of Swiss mouse 3T3-D1 cells with physiological concentrations of insulin resulted in a rapid and transient activation of protein phosphatase activity as measure by using ({sup 32}P)phosphorylase {alpha} as substrate. Activation reached a maximum level (140% of control value) within 5 min of addition and returned to control levels within 20 min. The effect of insulin was dose-dependent with half-maximal activation occurring at {approx}5 nM insulin. This activity could be completely inhibited by addition of the heat-stable protein inhibitor 2, which suggests the presence of an activated type-1 phosphatase. Similar effects on phosphatase activity were seen when epidermal growth factor and platelet-derived growth factor were tested. These results suggest that some of the intracellular effects caused by insulin and growth factors are mediated through the activation of a protein phosphatase.

  6. Platelet-activating factor induces ovine fetal pulmonary venous smooth muscle cell proliferation: role of epidermal growth factor receptor transactivation.

    PubMed

    Zhou, Weilin; Ibe, Basil O; Raj, J Usha

    2007-06-01

    We have previously reported that platelet-activating factor (PAF) is present in very high levels in the ovine fetal lung and circulation and that PAF serves as an important physiological vasoconstrictor of the pulmonary circulation in utero. However, it is not known whether PAF stimulates pulmonary vascular smooth muscle cell (SMC) proliferation. In this study, we used ovine fetal pulmonary venous SMCs as our model system to study the effects and mechanisms of action of PAF on SMC proliferation. We found that PAF induced SMC proliferation in a dose-dependent manner. PAF also stimulated activation of both ERK and p38 but not c-Jun NH(2) terminal kinase (JNK) mitogen-activated protein (MAP) kinase pathways. PAF (10 nM) induced phosphorylation of epidermal growth factor receptor (EGFR). Specific inhibition of EGFR by AG-1478 and by the expression of a dominant-negative EGFR mutant in SMCs attenuated PAF-stimulated cell proliferation. Inhibition of heparin-binding EGF-like growth factor (HB-EGF) release by CRM-197 and inhibition of matrix metalloproteinases (MMP) by GM-6001 abolished PAF-induced MAP kinase activation and cell proliferation. Increased alkaline phosphatase (AP) activity after PAF treatment in AP-HB-EGF fusion construct-transfected SMCs indicated that PAF induced the release of HB-EGF within 1 min. Gelatin zymography data showed that PAF stimulated MMP-2 activity and MMP-9 activity within 1 min. These results suggest that PAF promotes pulmonary vascular SMC proliferation via transactivation of EGFR through MMP activation and HB-EGF, resulting in p38 and ERK activation and that EGFR transactivation is essential for the mitogenic effect of PAF in pulmonary venous SMC. PMID:17322418

  7. Glioma-secreted soluble factors stimulate microglial activation: The role of interleukin-1β and tumor necrosis factor-α.

    PubMed

    Hwang, Ji-Sun; Jung, Eun-Hye; Kwon, Mi-Youn; Han, Inn-Oc

    2016-09-15

    We aimed to elucidate the effect of soluble factors secreted by glioma on microglial activation. Conditioned medium (CM) from glioma cells, CRT-MG and C6, significantly induced nitric oxide (NO) production and stimulated the mRNA expression of inducible NO synthase (iNOS), interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-α) and cyclooxygenase 2 (COX-2) in BV2 cells. Glioma CM stimulated p38 mitogen-activated protein kinase (MAPK) phosphorylation, and a p38 MAPK inhibitor, SB203580, suppressed CM-induced NO production in BV2 cells. In addition, CM stimulated nuclear factor-kappaB (NF-κB) DNA binding and transcriptional activity, which was repressed by SB203580. Gliomas displayed higher mRNA expression and release of TNF-α and IL-1β than primary astrocyte cells. Neutralization of TNF-α and IL-1β in C6-CM using a neutralizing antibody inhibited NO/iNOS expression in BV-2 cells. These results indicate potential contribution of diffusible tumor-derived factors to regulate microglial activation and subsequent tumor microenvironment. PMID:27609291

  8. Effects of biological and environmental factors on activity rhythms of wild animals.

    PubMed

    Tester, J R; Figala, J

    1990-01-01

    This paper reviews information on the effects of biological and environmental factors on activity rhythms of wild animals monitored by radio telemetry. Variations in radio signals received from free-ranging animals are used to determine the pattern of activity and rest. Telemetry is especially effective for obtaining activity data from wild animals at night and from those living in dense vegetation or underground. Biological factors such as breeding behavior, care of young, time of last eating, and food storage cause changes in daily activity patterns. Similarly, environmental factors such as temperature, snow cover, food supply and disturbance caused by humans in an urban setting also cause changes in daily activity patterns. The observed modifications of activity rhythms show that controlling mechanisms allow wild animals to quickly respond to changing biological and environmental factors.

  9. [Family factors influence active commuting to school in Spanish children].

    PubMed

    Rodríguez-López, Carlos; Villa-González, Emilio; Pérez-López, Isaac J; Delgado-Fernández, Manuel; Ruiz, Jonatan R; Chillón, Palma

    2013-01-01

    Introducción: El desplazamiento activo al colegio contribuye a aumentar los niveles de actividad física en niños. Los factores familiares pueden determinar dicho comportamiento. Objetivo: El objetivo fue analizar la asociación de la actividad laboral y el desplazamiento al trabajo de los padres con el modo de desplazamiento de sus hijos. Método: Participaron 721 familias de 4 colegios de la provincia de Granada. Las familias completaron un cuestionario sobre el modo de desplazamiento de sus hijos, la actividad laboral y el modo de desplazamiento de los padres, y la distancia y tiempo del trayecto al colegio de sus hijos. Las asociaciones entre la actividad laboral de las familias y modo de desplazamiento al trabajo con el desplazamiento activo al colegio de sus hijos se estudiaron con regresión logística binaria ajustando por distancia al colegio y edad de los hijos. Resultados: Los niños cuyos padres y madres no trabajaban eran más propensos a ir de forma activa al colegio que aquellos donde ambos trabajaban (p = 0,023; OR: 2,67; 95% IC: 1,14-6,23). Los niños cuyos padres y madres se desplazaban de forma activa al trabajo eran más propensos a ir de forma activa al colegio que aquellos donde ambos padres se desplazaban de forma pasiva al trabajo (p = 0,014; OR: 6,30; 95% IC: 1,45-27,26). Conclusión: Los factores familiares estaban relacionados con el modo de desplazamiento de los niños al colegio: en familias con desempleo y en familias con empleo donde los padres se desplazan al trabajo de forma activa, los hijos parecen ser más activos.

  10. Heparanase procoagulant activity, factor Xa, and plasminogen activator inhibitor 1 are increased in shift work female nurses.

    PubMed

    Nadir, Yona; Saharov, Gleb; Hoffman, Ron; Keren-Politansky, Anat; Tzoran, Inna; Brenner, Benjamin; Shochat, Tamar

    2015-07-01

    Epidemiologic studies indicate on an increased risk of cardiovascular disease and cancer in shift workers, although the underlying mechanism is obscure. Heparanase directly enhances tissue factor (TF) activity leading to increased factor Xa production and subsequent activation of the coagulation system. In the present study, a comparison of coagulation markers among healthy shift working (SW) vs. healthy daytime working (DW) female nurses was performed. Thirty SW and 30 DW female nurses were enrolled. For each of the 60 participants, blood was drawn between 7:00 and 8:00 a.m. and at least 8 h after the last work shift. Plasma was studied for coagulation marker that included TF/heparanase procoagulant activity, TF activity, heparanase procoagulant activity, heparanase level, factor Xa level, plasminogen activator inhibitor 1 (PAI-1), plasminogen, α2-antiplasmin, fibrinogen, global protein C, von Willebrand factor, and D-dimer by chromogenic assays and enzyme-linked immunosorbent assays (ELISAs). Sleep quality was assessed by self-report according to the Pittsburgh Sleep Quality Index. The heparanase procoagulant activity increased by 2-fold and the TF/heparanase procoagulant activity increased by 1.5-fold in SW nurses compared to DW nurses (P < 0.05). Factor Xa levels and PAI-1 levels were significantly higher among SW nurses compared to the DW group (22 vs. 18 ng/ml, P < 0.05, and 32 vs. 22 ng/ml, P < 0.005, respectively). No significant differences were found in the other tested coagulation markers between the study groups. Heparanase procoagulant activity, factor Xa level, and PAI-1 level were significantly higher in SW nurses compared to the DW group. These alterations of blood coagulation activation may potentially contribute to cardiovascular and cancer morbidity.

  11. High power density aqueous hybrid supercapacitor combining activated carbon and highly conductive spinel cobalt oxide

    NASA Astrophysics Data System (ADS)

    Godillot, G.; Taberna, P.-L.; Daffos, B.; Simon, P.; Delmas, C.; Guerlou-Demourgues, L.

    2016-11-01

    The remarkable electrochemical behavior of complete activated carbon/cobalt oxide cells is reported in the present work. Among the various weight ratios between the positive and negative electrodes evaluated, the best features are obtained with an overcapacitive cobalt oxide electrode. The energy densities obtained by this system (20 Wh kg-1 for a power density of 209 W kg-1) are twice higher than those measured for a activated carbon/activated carbon symmetric cell, in the same operating conditions. With discharge capacities around 62 F g-1, this system is among the best ones reported in the literature for this category.

  12. Activation of the Retroviral Budding Factor ALIX▿†

    PubMed Central

    Zhai, Qianting; Landesman, Michael B.; Chung, Hyo-Young; Dierkers, Adam; Jeffries, Cy M.; Trewhella, Jill; Hill, Christopher P.; Sundquist, Wesley I.

    2011-01-01

    The cellular ALIX protein functions within the ESCRT pathway to facilitate intralumenal endosomal vesicle formation, the abscission stage of cytokinesis, and enveloped virus budding. Here, we report that the C-terminal proline-rich region (PRR) of ALIX folds back against the upstream domains and auto-inhibits V domain binding to viral late domains. Mutations designed to destabilize the closed conformation of the V domain opened the V domain, increased ALIX membrane association, and enhanced virus budding. These observations support a model in which ALIX activation requires dissociation of the autoinhibitory PRR and opening of the V domain arms. PMID:21715492

  13. Building an index of activity of inhabitants from their activity on the residential electrical power line.

    PubMed

    Noury, Norbert; Berenguer, Marc; Teyssier, Henri; Bouzid, Marie-Jeanne; Giordani, Michel

    2011-09-01

    In the framework of context awareness within the home, our team is currently assessing the unobtrusive detection of inhabitants' activity through the monitoring of their use and consumption of electricity. The objective is to develop a system for the remote monitoring of large populations of elderly people living independently at home. To be readily deployable on the field, such a system must be minimally intrusive both for the home environment and for the field professionals (paramedics and social workers) visiting the patients at home. We carried out two successive field experiments to evaluate and to improve our system designed to deliver a single index of daily activity. The first experiment involved 13 elderly persons over a nine-month period (84,240 h data recorded) and the second one 12 elderly over six months (51,840 h). We evaluated both the relevance of the index and the acceptability of the system as a whole. We discovered that electrical activity is a kind of unique "signature" of each person's activity. Moreover, this profile provides unexpected information on the health status of the subject. We confirmed that the system was unobtrusive and well accepted both by the subjects and by the professionals involved. Our unique index of activity, and its trend over time, can provide timely information to the professionals on the patient.

  14. The feasibility of recycling and clearance of active materials from fusion power plants

    NASA Astrophysics Data System (ADS)

    Zucchetti, M.; El-Guebaly, L. A.; Forrest, R. A.; Marshall, T. D.; Taylor, N. P.; Tobita, K.

    2007-08-01

    In order to minimize the quantity of active materials that require long-term storage, arising during operation and after fusion power plant decommissioning, maximum use should be made of both recycling within the nuclear industry and clearance. For the latter, revised limits have been recently issued at the international level and in the US and Europe. In this paper the implications for fusion materials of these new levels are considered. Concerning recycling, power plant studies have employed criteria based solely on radiological parameters. Reviews of remote procedures currently used within the nuclear industry suggest that these criteria have been unduly conservative and should be revised.

  15. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    PubMed

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  16. Gc-protein-derived macrophage activating factor counteracts the neuronal damage induced by oxaliplatin.

    PubMed

    Morucci, Gabriele; Branca, Jacopo J V; Gulisano, Massimo; Ruggiero, Marco; Paternostro, Ferdinando; Pacini, Alessandra; Di Cesare Mannelli, Lorenzo; Pacini, Stefania

    2015-02-01

    Oxaliplatin-based regimens are effective in metastasized advanced cancers. However, a major limitation to their widespread use is represented by neurotoxicity that leads to peripheral neuropathy. In this study we evaluated the roles of a proven immunotherapeutic agent [Gc-protein-derived macrophage activating factor (GcMAF)] in preventing or decreasing oxaliplatin-induced neuronal damage and in modulating microglia activation following oxaliplatin-induced damage. The effects of oxaliplatin and of a commercially available formula of GcMAF [oleic acid-GcMAF (OA-GcMAF)] were studied in human neurons (SH-SY5Y cells) and in human microglial cells (C13NJ). Cell density, morphology and viability, as well as production of cAMP and expression of vascular endothelial growth factor (VEGF), markers of neuron regeneration [neuromodulin or growth associated protein-43 (Gap-43)] and markers of microglia activation [ionized calcium binding adaptor molecule 1 (Iba1) and B7-2], were determined. OA-GcMAF reverted the damage inflicted by oxaliplatin on human neurons and preserved their viability. The neuroprotective effect was accompanied by increased intracellular cAMP production, as well as by increased expression of VEGF and neuromodulin. OA-GcMAF did not revert the effects of oxaliplatin on microglial cell viability. However, it increased microglial activation following oxaliplatin-induced damage, resulting in an increased expression of the markers Iba1 and B7-2 without any concomitant increase in cell number. When neurons and microglial cells were co-cultured, the presence of OA-GcMAF significantly counteracted the toxic effects of oxaliplatin. Our results demonstrate that OA-GcMAF, already used in the immunotherapy of advanced cancers, may significantly contribute to neutralizing the neurotoxicity induced by oxaliplatin, at the same time possibly concurring to an integrated anticancer effect. The association between these two powerful anticancer molecules would probably produce

  17. Active photonic sensor communication cable for field application of optical data and power transmission

    NASA Astrophysics Data System (ADS)

    Suthau, Eike; Rieske, Ralf; Zerna, Thomas

    2014-10-01

    Omitting electrically conducting wires for sensor communication and power supply promises protection for sensor systems and monitored structures against lightning or high voltages, prevention of explosion hazards, and reduction of susceptibility to tampering. The ability to photonically power remote systems opens up the full range of electrical sensors. Power-over-fiber is an attractive option in electromagnetically sensitive environments, particularly for longterm, maintenance-free applications. It can deliver uninterrupted power sufficient for elaborate sensors, data processing or even actuators alongside continuous high speed data communication for remote sensor application. This paper proposes an active photonic sensor communication system, which combines the advantages of optical data links in terms of immunity to electromagnetic interference (EMI), high bandwidth, hardiness against tampering or eavesdropping, and low cable weight with the robustness one has come to expect from industrial or military electrical connectors. An application specific integrated circuit (ASIC) is presented that implements a closed-loop regulation of the sensor power supply to guarantee continuous, reliable data communications while maintaining a highly efficient, adaptive sensor supply scheme. It is demonstrated that the resulting novel photonic sensor communication cable can handle sensors and actuators differing orders of magnitude with respect to power consumption. The miniaturization of the electro-optical converters and driving electronics is as important to the presented development as the energy efficiency of the detached, optically powered sensor node. For this reason, a novel photonic packaging technology based on wafer-level assembly of the laser power converters by means of passive alignment will be disclosed in this paper.

  18. Yeast peptide pheromones, a-factor and alpha-factor, activate a common response mechanism in their target cells.

    PubMed

    Bender, A; Sprague, G F

    1986-12-26

    We show that in yeast the cell type specificity of pheromone response is determined solely by the species of receptor that a cell synthesizes. The two receptor-pheromone interactions are functionally interchangeable and involve the creation of a common intracellular signal. In particular, we find that provision of a-factor receptor or alpha-factor receptor in mat alpha 1 mutants, which normally do not express either receptor or any other a- or alpha-specific products, allows response to the appropriate pheromone. Moreover, provision of a-factor receptor in a cells lacking alpha-factor receptor restores mating competence to those cells. Finally, an aspect of pheromone response that is normally unique to a-factor action on alpha cells--increased transcription from the alpha-specific STE3 gene--can also be observed following alpha-factor treatment of pseudo-a cells (mat alpha 2 ste3 ste13), special mutants that respond to alpha-factor and also have an active STE3 promoter.

  19. Variable Glutamine-Rich Repeats Modulate Transcription Factor Activity

    PubMed Central

    Gemayel, Rita; Chavali, Sreenivas; Pougach, Ksenia; Legendre, Matthieu; Zhu, Bo; Boeynaems, Steven; van der Zande, Elisa; Gevaert, Kris; Rousseau, Frederic; Schymkowitz, Joost; Babu, M. Madan; Verstrepen, Kevin J.

    2015-01-01

    Summary Excessive expansions of glutamine (Q)-rich repeats in various human proteins are known to result in severe neurodegenerative disorders such as Huntington’s disease and several ataxias. However, the physiological role of these repeats and the consequences of more moderate repeat variation remain unknown. Here, we demonstrate that Q-rich domains are highly enriched in eukaryotic transcription factors where they act as functional modulators. Incremental changes in the number of repeats in the yeast transcriptional regulator Ssn6 (Cyc8) result in systematic, repeat-length-dependent variation in expression of target genes that result in direct phenotypic changes. The function of Ssn6 increases with its repeat number until a certain threshold where further expansion leads to aggregation. Quantitative proteomic analysis reveals that the Ssn6 repeats affect its solubility and interactions with Tup1 and other regulators. Thus, Q-rich repeats are dynamic functional domains that modulate a regulator’s innate function, with the inherent risk of pathogenic repeat expansions. PMID:26257283

  20. Confirmatory Factor Analysis of Project Spectrum Activities. A Second-Order "g" Factor or Multiple Intelligences?

    ERIC Educational Resources Information Center

    Castejon, Juan L.; Perez, Antonio M.; Gilar, Raquel

    2010-01-01

    This paper compares different theoretical models of the structure of intelligence, based on the analysis of data obtained in a series of measured abilities corresponding to the Spectrum assessment activities (Gardner, Feldman & Krechevsky, 1998) in a sample of 393 children enrolled in kindergarten and first grade. The data were analyzed using…

  1. The Issue of Power in the Identification of "g" with Lower-Order Factors

    ERIC Educational Resources Information Center

    Matzke, Dora; Dolan, Conor V.; Molenaar, Dylan

    2010-01-01

    In higher order factor models, general intelligence (g) is often found to correlate perfectly with lower-order common factors, suggesting that g and some well-defined cognitive ability, such as working memory, may be identical. However, the results of studies that addressed the equivalence of g and lower-order factors are inconsistent. We suggest…

  2. Evaluation of Potential Clinical Surrogate Markers of a Trauma Induced Alteration of Clotting Factor Activities

    PubMed Central

    Payas, Arzu; Schoeneberg, Carsten; Wegner, Alexander; Kauther, Max Daniel; Lendemans, Sven

    2016-01-01

    Objective. The aim of this study was to identify routinely available clinical surrogate markers for potential clotting factor alterations following multiple trauma. Methods. In 68 patients admitted directly from the scene of the accident, all soluble clotting factors were analyzed and clinical data was collected prospectively. Ten healthy subjects served as control group. Results. Patients showed reduced activities of clotting factors II, V, VII, and X and calcium levels (all P < 0.0001 to 0.01). Levels of hemoglobin and base deficit correlated moderately to highly with the activities of a number of clotting factors. Nonsurvivors and patients who needed preclinical intubation or hemostatic therapy showed significantly reduced factor activities at admission. In contrast, factor VIII activity was markedly elevated after injury in general (P < 0.0001), but reduced in nonsurvivors (P < 0.05). Conclusions. Multiple trauma causes an early reduction of the activities of nearly all soluble clotting factors in general. Initial hemoglobin and, with certain qualifications, base deficit levels demonstrated a potential value in detecting those underlying clotting factor deficiencies. Nevertheless, their role as triggers of a hemostatic therapy as well as the observed response of factor VIII to multiple trauma and also its potential prognostic value needs further evaluation. PMID:27433474

  3. Physicochemical characterization and biological activity of intrinsic factor in cystic fibrosis.

    PubMed

    Monin, B; Guéant, J L; Gérard, A; Michalski, J C; Vidailhet, M; Grignon, G; Nicolas, J P

    1990-01-01

    Absorption of crystalline labeled cobalamin is strongly decreased in cases of cystic fibrosis. In order to determine if this is due to an alteration or a lack of activation of intrinsic factor by proteases, the physicochemical properties and biological activity of intrinsic factor have been studied. Intrinsic factor was purified 800-fold from stimulated gastric juice of cystic fibrosis patients with a yield of 64.2%. Cystic fibrosis intrinsic factor had an estimated Mr of 57,000 in SDS-polyacrylamide gel electrophoresis. Its carbohydrate content resembled that of normal human intrinsic factor, except that the ratio fucose/sialic acid was higher (6.1 and 1.6, respectively) and that the content in N-acetylgalactosamine was decreased. The same alterations in carbohydrate composition were observed for Hc purified from cystic fibrosis saliva. Purified intrinsic factor from cystic fibrosis gastric juice was biologically active in vitro in the presence of ileal solubilized receptor as well as in vivo (Schilling test). The fate of iodinated cystic fibrosis intrinsic factor in guinea pig ileum studied by high-resolution radioautography was similar to that of normal intrinsic factor. In conclusion, despite modifications of the carbohydrate content of the molecule, the biological activity of intrinsic factor is not altered in cases of cystic fibrosis. The malassimilation of crystalline cobalamin observed in cystic fibrosis is due to a mechanism independent from intrinsic factor secretion. PMID:2324885

  4. 77 FR 24950 - Meeting Related to the Transmission Planning Activities of the Southwest Power Pool, Inc.; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... Power Pool, Inc.; Notice of Commission Staff Attendance The Federal Energy Regulatory Commission hereby... transmission planning activities of the Southwest Power Pool, Inc. (SPP): Strategic Planning Committee Task... Plains, LLC. Docket No. ER11-4105-000, Southwest Power Pool, Inc. Docket No. EL11-34-001,...

  5. Hypoxic preconditioning decreases nuclear factor κB activity via Disrupted in Schizophrenia-1.

    PubMed

    Liu, Jia-Ren; Liu, Qian; Khoury, Joseph; Li, Yue-Jin; Han, Xiao-Hui; Li, Jing; Ibla, Juan C

    2016-01-01

    Nuclear factor κB is a key mediator of inflammation during conditions of hypoxia. Here, we used models of hypoxic pre-conditioning as mechanism to decrease nuclear factor κB activity induced by hypoxia. Our initial studies suggested that Disrupted in Schizophrenia-1 may be induced by hypoxic pre-conditioning and possibly involved in the regulation of nuclear factor κB. In this study we used Disrupted in Schizophrenia-1 exogenous over-expression and knock-down to determine its effect on ataxia telangiectasia mutated--nuclear factor κB activation cascade. Our results demonstrated that hypoxic pre-conditioning significantly increased the expression of Disrupted in Schizophrenia-1 at mRNA and protein levels both in vitro and in vivo. Over-expression of Disrupted in Schizophrenia-1 significantly attenuated the hypoxia-mediated ataxia telangiectasia mutated phosphorylation and prevented its cytoplasm translocation where it functions to activate nuclear factor κB. We further determined that Disrupted in Schizophrenia-1 activated the protein phosphatase 2A, preventing the phosphorylation of ataxia telangiectasia mutated serine-1981, the main regulatory site of ataxia telangiectasia mutated activity. Cellular levels of Disrupted in Schizophrenia-1 protein significantly decreased nuclear factor κB activation profiles and pro-inflammatory gene expression. Taken together, these results demonstrate that hypoxic pre-conditioning decreases the activation of nuclear factor κB through the transcriptional induction of Disrupted in Schizophrenia-1.

  6. Activation of clotting factors XI and IX in patients with acute myocardial infarction.

    PubMed

    Minnema, M C; Peters, R J; de Winter, R; Lubbers, Y P; Barzegar, S; Bauer, K A; Rosenberg, R D; Hack, C E; ten Cate, H

    2000-11-01

    In acute coronary events, plaque rupture and the subsequent formation of the catalytic tissue factor-factor VIIa complex is considered to initiate coagulation. It is unknown whether clotting factors XI and IX are activated in acute coronary events. Therefore, we prospectively investigated the activation of clotting factors XI and IX as well as activation of the contact system and the common pathway in 50 patients with acute myocardial infarction (AMI), in 50 patients with unstable angina pectoris (UAP), and in 50 patients with stable angina pectoris (SAP). Factor XIa-C1 inhibitor complexes, which reflect acute activation of factor XI, were detected in 24% of the patients with AMI, 8% of the patients with UAP, and 4% of the patients with SAP (P<0.05), whereas factor XIa-alpha(1)-antitrypsin complexes, which reflect chronic activation, were observed equally in all 3 study groups. Factor IX peptide levels were significantly higher in the patients with AMI and UAP compared with the patients with SAP (P<0.01). No differences regarding markers of the common pathway were demonstrated. Fibrinopeptide A levels were elevated in patients with AMI compared with patients with UAP and those with SAP (P<0.01). Factor XIIa- or kallikrein-C1 inhibitor complexes were not increased. In conclusion, this is the first demonstration of the activation of clotting factors XI and IX in patients with acute coronary syndromes. Because these clotting factors are considered to be important for continuous thrombin generation and clot stability, their activation might have clinical and therapeutic consequences.

  7. Exploring Contextual Factors and Patient Activation: Evidence from a Nationally Representative Sample of Patients with Depression

    ERIC Educational Resources Information Center

    Chen, Jie; Mortensen, Karoline; Bloodworth, Robin

    2014-01-01

    Patient activation has been considered as a "blockbuster drug of the century." Patients with mental disorders are less activated compared to patients with other chronic diseases. Low activation due to mental disorders can affect the efficiency of treatment of other comorbidities. Contextual factors are significantly associated with…

  8. Factors Associated with High Levels of Physical Activity among Adults with Intellectual Disability

    ERIC Educational Resources Information Center

    Temple, Viviene A.

    2009-01-01

    The aim was to identify factors associated with physical activity participation among active (i.e. more than or equal to 10 000 steps per day) individuals with intellectual disability. Staff at day program and supported employment organizations were asked to identify individuals they believed were physically active. To verify participants were…

  9. Factors Predicting Behavioral Response to a Physical Activity Intervention among Adolescent Females

    ERIC Educational Resources Information Center

    Dunton, Genevieve Fridlund; Schneider, Margaret; Cooper, Dan M.

    2007-01-01

    Objective: To determine whether individual factors influenced rates of physical activity change in response to a school-based intervention. Methods: Sedentary adolescent females (N = 63) participated in a 9-month physical activity program. Weekly levels of leisure-time physical activity were reported using an interactive website. Results: Change…

  10. Instantaneous quantification of skeletal muscle activation, power production, and fatigue during cycle ergometry.

    PubMed

    Coelho, A C; Cannon, D T; Cao, R; Porszasz, J; Casaburi, R; Knorst, M M; Rossiter, H B

    2015-03-01

    A rapid switch from hyperbolic to isokinetic cycling allows the velocity-specific decline in maximal power to be measured, i.e., fatigue. We reasoned that, should the baseline relationship between isokinetic power (Piso) and electromyography (EMG) be reproducible, then contributions to fatigue may be isolated from 1) the decline in muscle activation (muscle activation fatigue); and 2) the decline in Piso at a given activation (muscle fatigue). We hypothesized that the EMG-Piso relationship is linear, velocity dependent, and reliable for instantaneous fatigue assessment at intolerance during and following whole body exercise. Healthy participants (n = 13) completed short (5 s) variable-effort isokinetic bouts at 50, 70, and 100 rpm to characterize baseline EMG-Piso. Repeated ramp incremental exercise tests were terminated with maximal isokinetic cycling (5 s) at 70 rpm. Individual baseline EMG-Piso relationships were linear (r(2) = 0.95 ± 0.04) and velocity dependent (analysis of covariance). Piso at intolerance (two legs, 335 ± 88 W) was ∼45% less than baseline [630 ± 156 W, confidence interval of the difference (CIDifference) 211, 380 W, P < 0.05]. Following intolerance, Piso recovered rapidly (F = 44.1; P < 0.05; η(2) = 0.79): power was reduced (P < 0.05) vs. baseline only at 0-min (CIDifference 80, 201 W) and 1-min recovery (CIDifference 13, 80 W). Activation fatigue and muscle fatigue (one leg) were 97 ± 55 and 60 ± 50 W, respectively. Mean bias ± limits of agreement for reproducibility were as follows: baseline Piso 1 ± 30 W; Piso at 0-min recovery 3 ± 35 W; and EMG at Piso 3 ± 14%. EMG power is linear, velocity dependent, and reproducible. Deviation from this relationship at the limit of tolerance can quantify the "activation" and "muscle" related components of fatigue during cycling.

  11. Predicting involvement in prison gang activity: street gang membership, social and psychological factors.

    PubMed

    Wood, Jane L; Alleyne, Emma; Mozova, Katarina; James, Mark

    2014-06-01

    The aim of this study was to examine whether street gang membership, psychological factors, and social factors such as preprison experiences could predict young offenders' involvement in prison gang activity. Data were collected via individual interviews with 188 young offenders held in a Young Offenders Institution in the United Kingdom. Results showed that psychological factors such as the value individuals attached to social status, a social dominance orientation, and antiauthority attitudes were important in predicting young offenders' involvement in prison gang activity. Further important predictors included preimprisonment events such as levels of threat, levels of individual delinquency, and levels of involvement in group crime. Longer current sentences also predicted involvement in prison gang activity. However, street gang membership was not an important predictor of involvement in prison gang activity. These findings have implications for identifying prisoners involved in prison gang activity and for considering the role of psychological factors and group processes in gang research.

  12. Neutron activation analysis of thermal power plant ash and surrounding area soils.

    PubMed

    Al-Masri, M S; Haddad, Kh; Alsomel, N; Sarhil, A

    2015-08-01

    Elemental concentrations of As, Cd, Co, Cr, Fe, Hg, Mo, Ni, Se, and Zn have been determined in fly and bottom ash collected from Syrian power plants fired by heavy oil and natural gas using instrumental neutron activation analysis. The results showed that all elements were more concentrated in fly ash than in the fly ash; there was a clear increasing trend of the elemental concentrations in the fly ash along the flue gas pathway. The annual emission of elements was estimated. Elemental concentrations were higher inside the campus area than in surrounding areas, and the lowest values were found in natural-gas-fired power plant. In addition, the levels have decreased as the distance from power plant campus increases. However, the levels in the surrounding villages were within the Syrian standard for agriculture soil.

  13. Neutron activation analysis of thermal power plant ash and surrounding area soils.

    PubMed

    Al-Masri, M S; Haddad, Kh; Alsomel, N; Sarhil, A

    2015-08-01

    Elemental concentrations of As, Cd, Co, Cr, Fe, Hg, Mo, Ni, Se, and Zn have been determined in fly and bottom ash collected from Syrian power plants fired by heavy oil and natural gas using instrumental neutron activation analysis. The results showed that all elements were more concentrated in fly ash than in the fly ash; there was a clear increasing trend of the elemental concentrations in the fly ash along the flue gas pathway. The annual emission of elements was estimated. Elemental concentrations were higher inside the campus area than in surrounding areas, and the lowest values were found in natural-gas-fired power plant. In addition, the levels have decreased as the distance from power plant campus increases. However, the levels in the surrounding villages were within the Syrian standard for agriculture soil. PMID:26220782

  14. PI and fuzzy logic controllers for shunt Active Power Filter--a report.

    PubMed

    P, Karuppanan; Mahapatra, Kamala Kanta

    2012-01-01

    This paper presents a shunt Active Power Filter (APF) for power quality improvements in terms of harmonics and reactive power compensation in the distribution network. The compensation process is based only on source current extraction that reduces the number of sensors as well as its complexity. A Proportional Integral (PI) or Fuzzy Logic Controller (FLC) is used to extract the required reference current from the distorted line-current, and this controls the DC-side capacitor voltage of the inverter. The shunt APF is implemented with PWM-current controlled Voltage Source Inverter (VSI) and the switching patterns are generated through a novel Adaptive-Fuzzy Hysteresis Current Controller (A-F-HCC). The proposed adaptive-fuzzy-HCC is compared with fixed-HCC and adaptive-HCC techniques and the superior features of this novel approach are established. The FLC based shunt APF system is validated through extensive simulation for diode-rectifier/R-L loads.

  15. Inspection of surveillance activities and administrative leave policy at Bonneville Power Administration, Portland, Oregon

    SciTech Connect

    Not Available

    1994-04-01

    The authors conducted an inspection of surveillance activities and administrative leave policy at the Bonneville Power Administration, Portland, Oregon. The purpose of their inspection was to determine if a covert video surveillance operation conducted at Bonneville Power Administration was consistent with Department of Energy policies and procedures and other applicable regulations and procedures, and to determine if administrative leave policies and procedures used at Bonneville Power Administration in a specific instance were consistent with Department of Energy requirements and the Code of Federal Regulations. This inspection focused on a specific incident that occurred in 1989 on the 5th floor of the BPA Headquarters Building located in Portland, Oregon. The incident involved the soiling of an employee`s personal property with what appeared to be urine.

  16. Active gamma-carboxylated human factor IX expressed using recombinant DNA techniques.

    PubMed

    de la Salle, H; Altenburger, W; Elkaim, R; Dott, K; Dieterlé, A; Drillien, R; Cazenave, J P; Tolstoshev, P; Lecocq, J P

    Factor IX (Christmas factor), a vitamin K-dependent plasma protein made in the liver, functions in the middle phase of the intrinsic pathway of blood coagulation. A functional deficiency of factor IX underlies haemophilia B, a chromosome X-linked recessive disease for which the major therapeutic approach is replacement treatment using factor IX concentrates. The cloning and characterization of the gene for human factor IX would mean that human factor IX could be produced in greater yield and purity through using recombinant DNA techniques. We have now used a human factor IX cDNA clone, inserted into a vaccinia virus-derived vector, to infect human hepatoma cells which normally produce no factor IX, and mouse fibroblasts. Fully active factor IX was produced by the hepatoma cells, whereas the fibroblasts produced a protein less active than natural factor IX, even in the presence of high levels of vitamin K. Human factor IX is extensively post-translationally modified, and thus represents probably the most complex protein produced in active form by recombinant DNA techniques to date. Our study also illustrates the potential of vaccinia virus-based vectors for expressing significant amounts of complex, clinically useful proteins in eukaryotic cells, in addition to its already demonstrated usefulness for producing live recombinant vaccines.

  17. Metabolism of platelet activating factor (PAF) by rabbit renal homogenates

    SciTech Connect

    Cagen, L.M.; Yeh, Y.M.; Baer, P.G.

    1986-05-01

    Rabbit renal cortical slices convert added (alkyl-/sup 3/H)-PAF to metabolites that cochromatograph with lyso-PAF and alkyl-acyl glycerophosphocholine (AAGPC) and to a tritiated nonpolar metabolite that is the principal product recovered from the tissues. Rabbit renal cortical homogenates convert mixtures of (alkyl-/sup 3/H)-PAF and (choline-/sup 14/C)-PAF to products that cochromatograph with lyso-PAF and with AAGPC and to a tritiated nonpolar and a /sup 14/C-labeled polar metabolite. Formation of the latter products follow parallel time courses; they are the principal species present after extended incubation (30 min). Enzymatic capacity for formation of these metabolites is concentrated in the microsomal fraction (100,000 x g pellet). Their formation by washed microsomes does not require the addition of cofactors, but their rate of formation is enhanced in the presence of high concentrations of Ca/sup + +/ (1mM) and abolished by EDTA (1.25mM) or EGTA (1.25mM). Formation of the polar metabolite does not appear to be due to phospholipase C or D activity. Its formation is not enhanced by addition of glutathione or 2-amino-6,7-dimethyl-tetrahydropteridine, cofactors that support oxidative dealkylation of alkyl ether phospholipids in other tissues. Conversion of PAF to final products other than AAGPC appears to be a significant pathway for disposition of this substance in rabbit kidney.

  18. A human factors evaluation of Extravehicular Activity gloves

    NASA Technical Reports Server (NTRS)

    O'Hara, John M.; Briganti, Michael; Cleland, John; Winfield, Dan

    1989-01-01

    One of the major problems faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human-hand capabilities. NASA has sponsored a program to develop a standardized set of tests designed to assess EVA-gloved hand capabilities in six performance domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based upon an assessment of general human-hand functioning and EVA task requirements, several tests within each performance domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand, an EVA glove without pressure, an EVA glove at operation pressure. Thus, the differential effect on performance of the glove with and without pressure was tested. Bare hand performance was used to 'calibrate' the effects. Ten subjects participated in the test setup as a repeated-measures experimental design. The paper will report the results of the test program.

  19. Free radical activity of industrial fibers: role of iron in oxidative stress and activation of transcription factors.

    PubMed Central

    Gilmour, P S; Brown, D M; Beswick, P H; MacNee, W; Rahman, I; Donaldson, K

    1997-01-01

    We studied asbestos, vitreous fiber (MMVF10), and refractory ceramic fiber (RCF1) from the Thermal Insulation Manufacturers' Association fiber repository regarding the following: free radical damage to plasmid DNA, iron release, ability to deplete glutathione (GSH), and activate redox-sensitive transcription factors in macrophages. Asbestos had much more free radical activity than any of the man-made vitreous fibers. More Fe3+ was released than Fe2+ and more of both was released at pH 4.5 than at pH 7.2. Release of iron from the different fibers was generally not a good correlate of ability to cause free radical injury to the plasmid DNA. All fiber types caused some degree of oxidative stress, as revealed by depletion of intracellular GSH. Amosite asbestos upregulated nuclear binding of activator protein 1 transcription factor to a greater level than MMVF10 and RCF1; long-fiber amosite was the only fiber to enhance activation of the transcription factor nuclear factor kappa B (NF kappa B). The use of cysteine methyl ester and buthionine sulfoximine to modulate GSH suggested that GSH homeostasis was important in leading to activation of transcription factors. We conclude that the intrinsic free radical activity is the major determinant of transcription factor activation and therefore gene expression in alveolar macrophages. Although this was not related to iron release or ability to deplete macrophage GSH at 4 hr, GSH does play a role in activation of NF kappa B. Images Figure 1. Figure 5. A Figure 5. B Figure 6. A Figure 6. B PMID:9400744

  20. Fibroblast growth factor, but not activin, is a potent activator of mitogen-activated protein kinase in Xenopus explants.

    PubMed Central

    Graves, L M; Northrop, J L; Potts, B C; Krebs, E G; Kimelman, D

    1994-01-01

    Isolated explants from the animal hemisphere of Xenopus embryos were incubated with Xenopus basic fibroblast growth factor (XbFGF) or human activin A. XbFGF incubation resulted in the rapid activation of mitogen-activated protein kinase (MAPK) and ribosomal S6 protein kinase (pp90rsk) in a dose-dependent manner with the highest levels of activation occurring at 50 ng/ml. Maximal activation occurred within 6-10 min after the addition of growth factor, and the activity of both kinases declined to unstimulated levels after 30 min. Activin was unable to activate either MAPK or pp90rsk in the Xenopus explants to a substantial level, although it induced dorsal mesoderm better than XbFGF under the same experimental conditions. The regulatory protein Xwnt-8 did not activate MAPK, nor did it enhance the activation of MAPK by XbFGF. XbFGF was able to activate MAPK through at least the midgastrula stage, suggesting that this family of growth factors may have a role in gastrula-stage events. Images PMID:7510404

  1. Site-dependent factors affecting the economic feasibility of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1977-01-01

    A procedure has been developed which can be used to determine the economic feasibility of solar powered absorption cooling systems. This procedure has been used in a study to investigate the influence of the site-dependent parameters on the economic feasibility of solar absorption cooling. The purpose of this study was to make preliminary site selections for solar powered absorption cooling systems. This paper summarizes the results of that study.

  2. Alpha Power, Alpha Asymmetry and Anterior Cingulate Cortex Activity in Depressed Males and Females

    PubMed Central

    Jaworska, Natalia; Blier, Pierre; Fusee, Wendy; Knott, Verner

    2012-01-01

    Left fronto-cortical hypoactivity, thought to reflect reduced activity in approach-related systems, and right parietal hypoactivity, associated with emotional under-arousal, have been noted in major depressive disorder (MDD). Altered theta activity in the anterior cingulate cortex (ACC) has also been associated with the disorder. We assessed resting frontal and parietal alpha asymmetry and power in non-medicated MDD (N=53; 29 females) and control (N=43; 23 females) individuals. Theta activity was examined using standardized low-resolution electromagnetic tomography (sLORETA) in the ACC [BA24ab and BA32 comprising the rostral ACC and BA25/subgenual (sg) ACC]. The MDD group, and particularly depressed males, displayed increased overall frontal and parietal alpha power and left midfrontal hypoactivity (alpha2-indexed). They also exhibited increased sgACC theta2 activity. MDD females had increased right parietal activity, suggesting increased emotive arousal. Thus, unmedicated depressed adults were characterized by lower activity in regions implicated in approach/positive affective tendencies as well as diffuse cortical hypoarousal, though sex specific modulations emerged. Altered theta in the sgACC may reflect emotion regulation abnormalities in MDD. PMID:22939462

  3. Newly diagnosed congenital factor VII deficiency and utilization of recombinant activated factor VII (NovoSeven®)

    PubMed Central

    Bartosh, Nicole S; Tomlin, Tara; Cable, Christian; Halka, Kathleen

    2013-01-01

    This case report presents a newly diagnosed congenital factor VII deficiency treated with recombinant activated factor VII (rFVIIa). Congenital factor VII deficiency is a rare autosomal-recessive bleeding disorder that occurs in fewer than 1/500,000 persons. Its presentation can vary from epistaxis to hemarthroses and severe central nervous system bleeding, and correlates poorly with factor VII levels. Our patient had not had a significant hemostatic challenge prior to his presentation and therefore never had any symptomatology suggestive of this disease. He was treated with rFVIIa, and was able to undergo repair of his fractures without bleeding. Case report A 19-year-old African-American male presented to the emergency room after an altercation that resulted in significant trauma. He sustained bilateral mandibular angle fractures and orbital floor fractures, requiring urgent surgical correction. On initial evaluation, he was noted to have a prolonged prothrombin time of 40.1 seconds, with an International Normalized Ratio of 4.0, a normal activated partial thromboplastin time of 29.9 seconds, and a platelet count of 241. After receiving vitamin K and fresh frozen plasma, he was taken to the operating room for a temporary rigid maxillomandibular fixation. A 1:1 mixing study with normal plasma corrected the prothrombin time (decreasing from 40.7 to 14.7 seconds) and a factor VII assay revealed 5% of the normal factor VII level. The patient was diagnosed with congenital factor VII deficiency. Due to his coagulopathy and the extensive surgical correction needed, rFVIIa was administered and surgery was accomplished without hemorrhagic sequelae. Conclusion This case report and review describes a rare congenital disease, the history of rFVIIa use, and its mechanism. rFVIIA use in our patient provided a treatment option that allowed the necessary surgical correction, but further prospective studies on dose optimization would ensure adequate dosing with minimal risk of

  4. High-temperature optically activated GaAs power switching for aircraft digital electronic control

    NASA Technical Reports Server (NTRS)

    Berak, J. M.; Grantham, D. H.; Swindal, J. L.; Black, J. F.; Allen, L. B.

    1983-01-01

    Gallium arsenide high-temperature devices were fabricated and assembled into an optically activated pulse-width-modulated power control for a torque motor typical of the kinds used in jet engine actuators. A bipolar heterojunction phototransistor with gallium aluminum arsenide emitter/window, a gallium arsenide junction field-effect power transistor and a gallium arsenide transient protection diode were designed and fabricated. A high-temperature fiber optic/phototransistor coupling scheme was implemented. The devices assembled into the demonstrator were successfully tested at 250 C, proving the feasibility of actuator-located switching of control power using optical signals transmitted by fibers. Assessments of the efficiency and technical merits were made for extension of this high-temperature technology to local conversion of optical power to electrical power and its control at levels useful for driving actuators. Optical power sources included in the comparisons were an infrared light-emitting diode, an injection laser diode, tungsten-halogen lamps and arc lamps. Optical-to-electrical power conversion was limited to photovoltaics located at the actuator. Impedance matching of the photovoltaic array to the load was considered over the full temperature range, -55 C to 260 C. Loss of photovoltaic efficiency at higher temperatures was taken into account. Serious losses in efficiency are: (1) in the optical source and the cooling which they may require in the assumed 125 C ambient, (2) in the decreased conversion efficiency of the gallium arsenide photovoltaic at 260 C, and (3) in impedance matching. Practical systems require improvements in these areas.

  5. Impact of Inertial Training on Strength and Power Performance in Young Active Men.

    PubMed

    Naczk, Mariusz; Naczk, Alicja; Brzenczek-Owczarzak, Wioletta; Arlet, Jarosław; Adach, Zdzisław

    2016-08-01

    Naczk, M, Naczk, A, Brzenczek-Owczarzak, W, Arlet, J, and Adach, Z. Impact of inertial training on strength and power performance in young active men. J Strength Cond Res 30(8): 2107-2113, 2016-This study evaluated how 5 weeks of inertial training using 2 different loads influenced strength and power performance. Fifty-eight male physical education students were randomly divided into training and control groups. The 2 training groups (T0 and T10) performed inertial training 3 times per week for 5 weeks using the new Inertial Training and Measurement System (ITMS). Each training session included 3 exercise sets involving the knee extensors muscles. The T0 group used only the mass of the ITMS flywheel (19.4 kg), whereas the T10 group had an additional 10 kg on the flywheel. Before and after training, we evaluated maximum force and power of knee extensors muscles, countermovement jump (CMJ), squat jump (SJ), maximal power output achieved during ergometer test PVT, electromyography of quadriceps, and muscle mass. In T0 and T10, respectively, ITMS training induced significant increases in muscle force (25.2 and 23.3%), muscle power (33.2 and 27%), CMJ (3.8 and 6.7%), SJ (2.2 and 6.1%), PVT (8 and 7.4%), and muscle mass (9.8 and 15%). The changes did not significantly differ between T0 and T10. A 16% significant increase of electromyography amplitude (quadriceps muscle) was noted only in T0. The novel ITMS training method is effective for improving muscular strength and power. Improvements in PVT, CMJ, and SJ indicate that the increased strength and power elicited by ITMS training can translate to improvements in sport performance. The ITMS training can also be useful for building muscle mass. PMID:27457914

  6. Combining Droop Curve Concepts with Control Systems for Wind Turbine Active Power Control: Preprint

    SciTech Connect

    Buckspan, A.; Aho, J.; Pao, L.; Fleming, P.; Jeong, Y.

    2012-06-01

    Wind energy is becoming a larger portion of the global energy portfolio and wind penetration has increased dramatically in certain regions of the world. This increasing wind penetration has driven the need for wind turbines to provide active power control (APC) services to the local utility grid, as wind turbines do not intrinsically provide frequency regulation services that are common with traditional generators. It is common for large scale wind turbines to be decoupled from the utility grid via power electronics, which allows the turbine to synthesize APC commands via control of the generator torque and blade pitch commands. Consequently, the APC services provided by a wind turbine can be more flexible than those provided by conventional generators. This paper focuses on the development and implementation of both static and dynamic droop curves to measure grid frequency and output delta power reference signals to a novel power set point tracking control system. The combined droop curve and power tracking controller is simulated and comparisons are made between simulations using various droop curve parameters and stochastic wind conditions. The tradeoffs involved with aggressive response to frequency events are analyzed. At the turbine level, simulations are performed to analyze induced structural loads. At the grid level, simulations test a wind plant's response to a dip in grid frequency.

  7. SIMULATIONS OF THE SUNYAEV-ZEL'DOVICH POWER SPECTRUM WITH ACTIVE GALACTIC NUCLEUS FEEDBACK

    SciTech Connect

    Battaglia, N.; Bond, J. R.; Pfrommer, C.; Sievers, J. L.; Sijacki, D.

    2010-12-10

    We explore how radiative cooling, supernova feedback, cosmic rays, and a new model of the energetic feedback from active galactic nuclei (AGNs) affect the thermal and kinetic Sunyaev-Zel'dovich (SZ) power spectra. To do this, we use a suite of hydrodynamical TreePM-SPH simulations of the cosmic web in large periodic boxes and tailored higher resolution simulations of individual galaxy clusters. Our AGN feedback simulations match the recent universal pressure profile and cluster mass scaling relations of the REXCESS X-ray cluster sample better than previous analytical or numerical approaches. For multipoles l {approx}< 2000, our power spectra with and without enhanced feedback are similar, suggesting that theoretical uncertainties over that range are relatively small, although current analytic and semi-analytic approaches overestimate this SZ power. We find the power at high 2000-10, 000 multipoles in which the Atacama Cosmology Telescope (ACT) and South Pole Telescope (SPT) probe is sensitive to the feedback prescription, and hence can constrain the theory of intracluster gas, in particular for the highly uncertain redshifts >0.8. The apparent tension between {sigma}{sub 8} from primary cosmic microwave background power and from analytic SZ spectra inferred using ACT and SPT data is lessened with our AGN feedback spectra.

  8. Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

    NASA Technical Reports Server (NTRS)

    Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

    2014-01-01

    This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

  9. Plasma levels of plasminogen activator inhibitor type 1, factor VIII, prothrombin activation fragment 1+2, anticardiolipin, and antiprothrombin antibodies are risk factors for thrombosis in hemodialysis patients.

    PubMed

    Molino, Daniela; De Santo, Natale G; Marotta, Rosa; Anastasio, Pietro; Mosavat, Mahrokh; De Lucia, Domenico

    2004-09-01

    Patients with end-stage renal disease are prone to hemorrhagic complications and simultaneously are at risk for a variety of thrombotic complications such as thrombosis of dialysis blood access, the subclavian vein, coronary arteries, cerebral vessel, and retinal veins, as well as priapism. The study was devised for the following purposes: (1) to identify the markers of thrombophilia in hemodialyzed patients, (2) to establish a role for antiphospholipid antibodies in thrombosis of the vascular access, (3) to characterize phospholipid antibodies in hemodialysis patients, and (4) to study the effects of dialysis on coagulation cascade. A group of 20 hemodialysis patients with no thrombotic complications (NTC) and 20 hemodialysis patients with thrombotic complications (TC) were studied along with 400 volunteer blood donors. Patients with systemic lupus erythematosus and those with nephrotic syndrome were excluded. All patients underwent a screening prothrombin time, activated partial thromboplastin time, fibrinogen (Fg), coagulation factors of the intrinsic and extrinsic pathways, antithrombin III (AT-III), protein C (PC), protein S (PS), resistance to activated protein C, prothrombin activation fragment 1+2 (F1+2), plasminogen, tissue type plasminogen activator (t-PA), plasminogen tissue activator inhibitor type-1 (PAI-1), anticardiolipin antibodies type M and G (ACA-IgM and ACA-IgG), lupus anticoagulant antibodies, and antiprothrombin antibodies type M and G (aPT-IgM and aPT-IgG). The study showed that PAI-1, F 1+2, factor VIII, ACA-IgM, and aPT-IgM levels were increased significantly over controls both in TC and NTC, however, they could distinguish patients with thrombotic complications from those without, being increased maximally in the former group. The novelty of the study is represented by the significant aPT increase that was observed in non-systemic lupus erythematosus hemodialysis patients, and particularly in those with thrombotic events. In addition

  10. Status of R&D activities on materials for fusion power reactors

    NASA Astrophysics Data System (ADS)

    Baluc, N.; Abe, K.; Boutard, J. L.; Chernov, V. M.; Diegele, E.; Jitsukawa, S.; Kimura, A.; Klueh, R. L.; Kohyama, A.; Kurtz, R. J.; Lässer, R.; Matsui, H.; Möslang, A.; Muroga, T.; Odette, G. R.; Tran, M. Q.; van der Schaaf, B.; Wu, Y.; Yu, J.; Zinkle, S. J.

    2007-10-01

    Current R&D activities on materials for fusion power reactors are mainly focused on plasma facing, structural and tritium breeding materials for plasma facing (first wall, divertor) and breeding blanket components. Most of these activities are being performed in Europe, Japan, the People's Republic of China, Russia and the USA. They relate to the development of new high temperature, radiation resistant materials, the development of coatings that will act as erosion, corrosion, permeation and/or electrical/MHD barriers, characterization of candidate materials in terms of mechanical and physical properties, assessment of irradiation effects, compatibility experiments, development of reliable joints, and development and/or validation of design rules. Priorities defined worldwide in the field of materials for fusion power reactors are summarized, as well as the main achievements obtained during the last few years and the near-term perspectives in the different investigation areas.

  11. DOE FUEL CELL R&D ACTIVITIES: TRANSPORTATION, STATIONARY, AND PORTABLE POWER APPLICATIONS

    SciTech Connect

    Payne, Terry L; Garland, Nancy

    2009-01-01

    Fuel Cell R&D Activities: Transportation, Stationary, and Portable Power Applications Terry Payne, PhD, PE, Technology development Manager; and Nancy Garland, PhD, Acting Fuel Cell Team Leader, Office of Hydrogen, Fuel Cells and Infrastructure Technologies, U.S. Department of Energy* In 2007, the Department of Energy s Hydrogen Program initiated new research and development projects aimed at reducing component cost and increasing stack durability and performance of transportation and stationary fuel cells. Updated progress in the Program including highlights from the new projects includes operation of a membrane electrode assembly over 7300 with voltage cycling. Market transformation activities in the Program such as forklifts for distribution centers and fuel cells for backup power will be discussed.

  12. Stimulation of hormone-responsive adenylate cyclase activity by a factor present in the cell cytosol.

    PubMed Central

    MacNeil, S; Crawford, A; Amirrasooli, H; Johnson, S; Pollock, A; Ollis, C; Tomlinson, S

    1980-01-01

    1. Homogenates of whole tissues were shown to contain both intracellular and extracellular factors that affected particulate adenylate cyclase activity in vitro. Factors present in the extracellular fluids produced an inhibition of basal, hormone- and fluoride-stimulated enzyme activity but factors present in the cell cytosol increased hormone-stimulated activity with relatively little effect on basal or fluoride-stimulated enzyme activity. 2. The existence of this cytosol factor or factors was investigated using freshly isolated human platelets, freshly isolated rat hepatocytes, and cultured cells derived from rat osteogenic sarcoma, rat calvaria, mouse melanoma, pig aortic endothelium, human articular cartilage chondrocytes and human bronchial carcinoma (BEN) cells. 3. The stimulation of the hormone response by the cytosol factor ranged from 60 to 890% depending on the tissue of origin of the adenylate cyclase. 4. In each case the behaviour of the factor was similar to the action of GTP on that particular adenylate cyclase preparation. 5. No evidence of tissue or species specificity was found, as cytosols stimulated adenylate cyclase from their own and unrelated tissues to the same degree. 6. In the human platelet, the inclusion of the cytosol in the assay of adenylate cyclase increased the rate of enzyme activity in response to stimulation by prostaglandin E1 without affecting the amount of prostaglandin E1 required for half-maximal stimulation or the characteristics of enzyme activation by prostaglandin E. PMID:7396869

  13. Immobilisation of homogeneous olefin polymerisation catalysts. Factors influencing activity and stability.

    PubMed

    Severn, John R; Chadwick, John C

    2013-07-01

    The activity and stability of homogeneous olefin polymerisation catalysts, when immobilised on a support, are dependent on both chemical and physical effects. Chemical factors affecting catalyst activity include the ease of formation of the active species, which is strongly dependent on the transition metal. Catalyst productivity is dependent on the balance between activity and stability. Immobilisation can lead to a lower proportion of active species and therefore lower initial polymerisation activity, but nevertheless give higher polymer yields in cases where increased catalyst stability is obtained. Important physical factors are support porosity and the ability of a support to undergo progressive fragmentation during polymerisation, facilitating monomer diffusion through the growing catalyst/polymer particle. This article illustrates the importance of these factors in olefin polymerisation with both early- and late-transition metal catalysts, with particular reference to the use of silica and magnesium chloride supports as well as to effects of immobilisation on polymer structure and properties. PMID:23467461

  14. Models for the activation pathway of epidermal growth factor receptor protein-tyrosine kinase

    SciTech Connect

    Campion, S.R.; Niyogi, S.K. )

    1991-03-15

    Activation of the epidermal growth factor (EGF) receptor's intrinsic protein-tyrosine kinase activity, which occurs upon formation of the receptor-ligand complex, is the critical regulatory event affecting the subsequent EGF-dependent cellular responses leading to DNA synthesis and cell proliferation. The molecular mechanism by which EGF-dependent activation of receptor kinase activity takes place is not clearly understood. In this study, the growth factor-dependent activation of the EGF receptor tyrosine kinase was examined in vitro using detergent-solubilized, partially purified GEF receptors from A5431 human epidermoid carcinoma cells. Evaluation of the cooperativity observed in the EGF-dependent activation of soluble receptor tyrosine kinase would suggest a mechanism requiring the binding of the EGF peptide to both ligand binding sites on a receptor dimer to induce full receptor kinase activity. Equations describing potential cooperative kinase activation pathways have been examined. The theoretical system which best simulates the allosteric regulation observed in the experimental kinase activation data is that describing multiple essential activation. In addition, studies using mutant analogs of the EGF peptide ligand appear to confirm the requirement for an essential conformational change in the receptor-ligand complex to activate the receptor kinase activity. Several mutant growth factor analogues are able to occupy the ligand binding sites on the receptor without inducing the fully active receptor conformation.

  15. The heparin-binding exosite is critical to allosteric activation of factor IXa in the intrinsic tenase complex: the role of arginine 165 and factor X.

    PubMed

    Misenheimer, Tina M; Buyue, Yang; Sheehan, John P

    2007-07-01

    Heparin inhibits the intrinsic tenase complex (factor IXa-factor VIIIa) via interaction with a factor IXa exosite. To define the role of this exosite, human factor IXa with alanine substituted for conserved surface residues (R126, N129, K132, R165, N178) was characterized. Chromogenic substrate hydrolysis by the mutant proteases was reduced 20-30% relative to factor IXa wild type. Coagulant activity was moderately (N129A, K132A, K126A) or dramatically (R165A) reduced relative to factor IXa wild type. Kinetic analysis demonstrated a marked reduction in apparent cofactor affinity (23-fold) for factor IXa R165, and an inability to stabilize cofactor activity. Factor IXa K126A, N129A, and K132A demonstrated modest reductions ( approximately 2-fold) in apparent cofactor affinity, and accelerated decay of intrinsic tenase activity. In the absence of factor VIIIa, factor IXa N178A and R165A demonstrated a defective Vmax(app) for factor X activation. In the presence of factor VIIIa, Vmax(app) varied in proportion to the predicted factor IXa-factor VIIIa concentration. However, factor IXa R165A had a 65% reduction in the kcat for factor X, suggesting an additional effect on catalysis. The ability of factor IXa to compete for physical assembly into the intrinsic tenase complex was enhanced by EGR-chloromethylketone bound to the factor IXa active site or addition of factor X, and reduced by selected mutations in the heparin-binding exosite (N178A, K126A, R165A). These results suggest that the factor IXa heparin-binding exosite participates in both cofactor binding and protease activation, and cofactor affinity is linked to active site conformation and factor X interaction during enzyme assembly.

  16. Annual Review of Editorial Committee Activities in Power and Energy Society, IEE of Japan

    NASA Astrophysics Data System (ADS)

    Editorial Committee Of Power; Energy Society

    The Editorial Committee is working in planning and editing of the publication of Power and Energy Society. In this article, activities of the committee of the last term are reported, and recent trend and future problems are also discussed. The process of planning and editing of the publication, and the challenges to reduce the necessary months for reviewing papers and to increase the number of submitted papers are shown.

  17. Intrapersonal, behavioral, and environmental factors associated with meeting recommended physical activity among rural Latino youth.

    PubMed

    Perry, Cynthia K; Saelens, Brian E; Thompson, Beti

    2011-11-01

    This study aimed to identify intrapersonal, behavioral, and environmental factors associated with engaging in recommended levels of physical activity among rural Latino middle school youth. Data were from an anonymous survey of 773 Latino youth (51% female) about level of and barriers and motivators to physical activity, risk behaviors, and park use. Logistic regression models identified factors correlated with meeting recommended levels of physical activity (5 days or more 3 60 min/day). Thirty-four percent of girls and 41% of boys reported meeting this physical activity recommendation. Participation in an organized after school activity (p < .001) and in physical education (PE) classes 5 days a week (p < .001) were strongly associated with meeting recommended physical activity level. Making PE available 5 days a week and creating opportunities for organized after school physical activity programs may increase the number of rural Latino middle school youth who meet recommended physical activity level.

  18. Phosphoinositide 3-Kinases Upregulate System xc− via Eukaryotic Initiation Factor 2α and Activating Transcription Factor 4 – A Pathway Active in Glioblastomas and Epilepsy

    PubMed Central

    Baxter, Paul; Kassubek, Rebecca; Albrecht, Philipp; Van Liefferinge, Joeri; Westhoff, Mike-Andrew; Halatsch, Marc-Eric; Karpel-Massler, Georg; Meakin, Paul J.; Hayes, John D.; Aronica, Eleonora; Smolders, Ilse; Ludolph, Albert C.; Methner, Axel; Conrad, Marcus; Massie, Ann; Hardingham, Giles E.

    2014-01-01

    Abstract Aims: Phosphoinositide 3-kinases (PI3Ks) relay growth factor signaling and mediate cytoprotection and cell growth. The cystine/glutamate antiporter system xc− imports cystine while exporting glutamate, thereby promoting glutathione synthesis while increasing extracellular cerebral glutamate. The aim of this study was to analyze the pathway through which growth factor and PI3K signaling induce the cystine/glutamate antiporter system xc− and to demonstrate its biological significance for neuroprotection, cell growth, and epilepsy. Results: PI3Ks induce system xc− through glycogen synthase kinase 3β (GSK-3β) inhibition, general control non-derepressible-2-mediated eukaryotic initiation factor 2α phosphorylation, and the subsequent translational up-regulation of activating transcription factor 4. This pathway is essential for PI3Ks to modulate oxidative stress resistance of nerve cells and insulin-induced growth in fibroblasts. Moreover, the pathway is active in human glioblastoma cells. In addition, it is induced in primary cortical neurons in response to robust neuronal activity and in hippocampi from patients with temporal lobe epilepsy. Innovation: Our findings further extend the concepts of how growth factors and PI3Ks induce neuroprotection and cell growth by adding a new branch to the signaling network downstream of GSK-3β, which, ultimately, leads to the induction of the cystine/glutamate antiporter system xc−. Importantly, the induction of this pathway by neuronal activity and in epileptic hippocampi points to a potential role in epilepsy. Conclusion: PI3K-regulated system xc− activity is not only involved in the stress resistance of neuronal cells and in cell growth by increasing the cysteine supply and glutathione synthesis, but also plays a role in the pathophysiology of tumor- and non-tumor-associated epilepsy by up-regulating extracellular cerebral glutamate. Antioxid. Redox Signal. 20: 2907–2922. PMID:24219064

  19. Thermoelectric power factor of ternary single-crystalline Sb2Te3- and Bi2Te3-based nanowires.

    PubMed

    Bäßler, Svenja; Böhnert, Tim; Gooth, Johannes; Schumacher, Christian; Pippel, Eckhard; Nielsch, Kornelius

    2013-12-13

    Nanowires of bismuth antimony telluride and bismuth telluride selenide (Bi15Sb29Te56 and Bi38Te55Se7) were grown by template-based pulsed electrodeposition. The composition and the crystallinity of the nanowires were determined by high-resolution transmission electron microscopy. The thermoelectric properties (Seebeck coefficient and electrical conductivity) of single p- and n-type nanowires, with diameter 80 nm and 200 nm, respectively, were determined as a function of temperature before and during heating in a helium atmosphere up to 300 K along the growth direction of the nanowires. After additional annealing in a tellurium atmosphere at 525 K, significantly enhanced transport properties are observed. Bulk-like power factors are achieved. In Bi38Te55Se7 nanowires, the Seebeck coefficients increase to -115 μV K(-1) and the thermoelectric power factors increase to 2820 μW K(-2) m(-1) at room temperature. In Bi15Sb29Te56 nanowires, Seebeck coefficients of up to S = +156 μV K(-1) and power factors of up to 1750 μW K(-2) m(-1) are obtained at room temperature.

  20. The Role of Power Doppler Ultrasonography as Disease Activity Marker in Rheumatoid Arthritis

    PubMed Central

    Bhasin, Shaloo; Cheung, Peter P.

    2015-01-01

    Structural damage in rheumatoid arthritis (RA) occurs early if inflammation is not treated promptly. Treatment targeted to reduce inflammation, in particular, that of synovial inflammation in the joints (synovitis), has been recommended as standard treat-to-target recommendations by rheumatologists. The goal is to achieve disease remission (i.e., no disease activity). Several accepted remission criteria have not always equated to the complete absence of true inflammation. Over the last decade, musculoskeletal ultrasonography has been demonstrated to detect subclinical synovitis not appreciated by routine clinical or laboratory assessments, with the Power Doppler modality allowing clinicians to more readily appreciate true inflammation. Thus, targeting therapy to Power Doppler activity may provide superior outcomes compared with treating to clinical targets alone, making it an attractive marker of disease activity in RA. However, more validation on its true benefits such as its benefits to patients in regard to patient related outcomes and issues with standardized training in acquisition and interpretation of power Doppler findings are required. PMID:26063952

  1. Passive and Active Protective Clothing against High-Power Laser Radiation

    NASA Astrophysics Data System (ADS)

    Hennigs, C.; Hustedt, M.; Kaierle, S.; Wenzel, D.; Markstein, S.; Hutter, A.

    The main objective of the work described in this paper was the development of passive and active protective clothing for the protection of the human skin against accidental laser irradiation and of active protective curtains. Here, the passive systems consist of functional multi-layer textiles, providing a high level of passive laser resistance. In addition, the active functional multi-layer textiles incorporate sensors that detect laser exposure and are, by means of a safety control, able to deactivate the laser beam automatically.Due to the lack of regulations for testing and qualifying textiles to be used as laser PPE, test methods were defined and validated. Additionally, corresponding testing set-ups were developed.Finally, the gap with respect to standardization was bridged by the definition of a test procedure and the requirements with respect to laser PPE.The developments were demonstrated by a set of tailored functional passive and active laser-protective clothing prototypes (gloves, jackets, aprons, trousers) and active curtains as well as by a prototype testing rig, providing the possibility to perform the specified low-power and high-power textile test procedure.

  2. The Contribution of Home, Neighbourhood and School Environmental Factors in Explaining Physical Activity among Adolescents

    PubMed Central

    Haerens, Leen; Craeynest, Mietje; Deforche, Benedicte; Maes, Lea; Cardon, Greet; De Bourdeaudhuij, Ilse

    2009-01-01

    The present study aimed at investigating the influence of home, neighbourhood and school environmental factors on adolescents' engagement in self-reported extracurricular physical activity and leisure time sports and on MVPA objectively measured by accelerometers. Environmental factors were assessed using questionnaires. Gender specific hierarchical regression analyses were conducted, with demographic variables entered in the first block, and environmental, psychosocial factors and interactions terms entered in the second block. Participation in extracurricular activities at school was positively related to the number of organized activities and the provision of supervision. Perceived accessibility of neighborhood facilities was not related to engagement in leisure time sports, whereas the availability of sedentary and physical activity equipment was. Findings were generally supportive of ecological theories stating that behaviors are influenced by personal and environmental factors that are constantly interacting. PMID:20041023

  3. Building predictive gene signatures through simultaneous assessment of transcription factor activation and gene expression.

    EPA Science Inventory

    Building predictive gene signatures through simultaneous assessment of transcription factor activation and gene expression Exposure to many drugs and environmentally-relevant chemicals can cause adverse outcomes. These adverse outcomes, such as cancer, have been linked to mol...

  4. Risk Factors for Clinically Significant Intimate Partner Violence among Active-Duty Members

    ERIC Educational Resources Information Center

    Smith Slep, Amy M.; Foran, Heather M.; Heyman, Richard E.; Snarr, Jeffery D.

    2011-01-01

    Hypothesized risk factors for men's and women's clinically significant intimate partner violence (CS-IPV) from four ecological levels (i.e., individual, family, workplace, community) were tested in a representative sample of active-duty U.S. Air Force members (N = 42,744). When considered together, we expected only individual and family factors to…

  5. Factors Influencing Entering Teacher Candidates' Preferences for Instructional Activities: A Glimpse into Their Orientations towards Teaching

    ERIC Educational Resources Information Center

    Talanquer, Vicente; Novodvorsky, Ingrid; Tomanek, Debra

    2010-01-01

    The present study was designed to identify and characterize the major factors that influence entering science teacher candidates' preferences for different types of instructional activities, and to analyze what these factors suggest about teacher candidates' orientations towards science teaching. The study involved prospective teachers enrolled in…

  6. Social Cognitive Factors Associated with Physical Activity in Elementary School Girls

    ERIC Educational Resources Information Center

    Bean, Melanie K.; Miller, Sara; Mazzeo, Suzanne E.; Fries, Elizabeth A.

    2012-01-01

    Objective: To examine social cognitive factors associated with physical activity (PA) among preadolescent girls. Method: Social cognitive theory was used to examine PA in girls (N = 90; 71% African American) participating in Girls on the Run. Multiple regressions explored factors associated with PA at posttesting and 3-month follow-up. Results:…

  7. Effects of submaximal activation on the determinants of power of chemically skinned rat soleus fibres.

    PubMed

    Gilliver, S F; Degens, H; Rittweger, J; Jones, D A

    2011-02-01

    Reducing the activating calcium concentration with skinned fibres is known to decrease isometric force and maximal shortening velocity, both of which will reduce the peak power. However, power is also a function of the curvature of the force-velocity relationship, and there is limited information on how changes in activating calcium affect this important property of muscle fibres. Force-velocity relationships of permeabilized single type I fibres from rat soleus muscle were determined using isotonic contractions at 15°C with both maximal (pCa 4.5) and submaximal activation (pCa 5.6). The rate of tension redevelopment (k(tr)), which provides a measure of sum of the apparent rate constants for cross-bridge attachment and detachment (f(app) + g(app)) following a rapid release and restretch, was also measured. Compared with pCa 4.5, specific tension (P(o)) at pCa 5.6 declined by 22 ± 8% (mean ± s.d.) and the maximal velocity of shortening (V(max)) fell by 44 ± 7%, but curvature of the force-velocity relationship (a/P(o)) rose by 47 ± 31%, indicating a less concave relationship. The value of k(tr) declined by 23 ± 7%. The change in a/P(o) reduced the impact of changes in P(o) and V(max) on peak power by approximately 25%. Fitting the data to Huxley's model of cross-bridge action suggests that lower activating calcium decreased both the rate constant for cross-bridge attachment (f) and that for detachment of negatively strained cross-bridges (g(2)). The fact that V(max) (and thus g(2)) changed to a greater extent than k(tr) (f(app) + g(app)) is the reason that reduced activation results in a reduction in curvature of the force-velocity relationship. PMID:20889604

  8. Partial purification of plasma thromboplastin antecedent (factor XI) and its activation by trypsin.

    PubMed

    Saito, H; Ratnoff, O D; Marshall, J S; Pensky, J

    1973-04-01

    A persistent puzzle in our understanding of hemostasis has been the absence of hemorrhagic symptoms in the majority of patients with Hageman trait, the hereditary deficiency of Hageman factor (factor XII). One proposed hypothesis is that alternative mechanisms exist in blood through which plasma thromboplastin antecedent (PTA, factor XI) can become active in the absence of Hageman factor. In order to test this hypothesis, the effect of several proteolytic enzymes, among them thrombin, plasma kallikrein, and trypsin, was tested upon unactivated PTA. PTA was prepared from normal human plasma by Ca(3)(PO(4))(2) adsorption, ammonium sulfate fractionation, and successive chromatography on QAE-Sephadex (twice). Sephadex-G150, and SP-Sephadex. The partially purified PTA was almost all in its native form, with a specific activity of 45-70 U/mg protein; the yield was about 10%. It contained no measurable amounts of other known clotting factors, plasmin, plasminogen, nor IgG. Incubation of PTA with trypsin generated potent clot-promoting activity that corrected the abnormally long clotting time of plasma deficient in Hageman factor or PTA but not in Christmas factor. This clot-promoting agent behaved like activated PTA on gel filtration (apparent molecular weight: 185,000) and was specifically inhibited by an antiserum directed against activated PTA. These data suggested that PTA can be converted into its active form by trypsin. PTA was not activated by thrombin, chymotrypsin, papain, ficin, plasmin, plasma kallikrein, tissue thromboplastin, or C. Trypsin converted PTA to its active form enzymatically. Whether trypsin serves to activate PTA in vivo is not yet clear.

  9. Positive feedback loops for factor V and factor VII activation supply sensitivity to local surface tissue factor density during blood coagulation.

    PubMed

    Balandina, A N; Shibeko, A M; Kireev, D A; Novikova, A A; Shmirev, I I; Panteleev, M A; Ataullakhanov, F I

    2011-10-19

    Blood coagulation is triggered not only by surface tissue factor (TF) density but also by surface TF distribution. We investigated recognition of surface TF distribution patterns during blood coagulation and identified the underlying molecular mechanisms. For these investigations, we employed 1), an in vitro reaction-diffusion experimental model of coagulation; and 2), numerical simulations using a mathematical model of coagulation in a three-dimensional space. When TF was uniformly immobilized over the activating surface, the clotting initiation time in normal plasma increased from 4 min to >120 min, with a decrease in TF density from 100 to 0.7 pmol/m(2). In contrast, surface-immobilized fibroblasts initiated clotting within 3-7 min, independently of fibroblast quantity and despite a change in average surface TF density from 0.5 to 130 pmol/m(2). Experiments using factor V-, VII-, and VIII-deficient plasma and computer simulations demonstrated that different responses to these two TF distributions are caused by two positive feedback loops in the blood coagulation network: activation of the TF-VII complex by factor Xa, and activation of factor V by thrombin. This finding suggests a new role for these reactions: to supply sensitivity to local TF density during blood coagulation.

  10. THE CALCULATION OF BURNABLE POISON CORRECTION FACTORS FOR PWR FRESH FUEL ACTIVE COLLAR MEASUREMENTS

    SciTech Connect

    Croft, Stephen; Favalli, Andrea; Swinhoe, Martyn T.

    2012-06-19

    Verification of commercial low enriched uranium light water reactor fuel takes place at the fuel fabrication facility as part of the overall international nuclear safeguards solution to the civilian use of nuclear technology. The fissile mass per unit length is determined nondestructively by active neutron coincidence counting using a neutron collar. A collar comprises four slabs of high density polyethylene that surround the assembly. Three of the slabs contain {sup 3}He filled proportional counters to detect time correlated fission neutrons induced by an AmLi source placed in the fourth slab. Historically, the response of a particular collar design to a particular fuel assembly type has been established by careful cross-calibration to experimental absolute calibrations. Traceability exists to sources and materials held at Los Alamos National Laboratory for over 35 years. This simple yet powerful approach has ensured consistency of application. Since the 1980's there has been a steady improvement in fuel performance. The trend has been to higher burn up. This requires the use of both higher initial enrichment and greater concentrations of burnable poisons. The original analytical relationships to correct for varying fuel composition are consequently being challenged because the experimental basis for them made use of fuels of lower enrichment and lower poison content than is in use today and is envisioned for use in the near term. Thus a reassessment of the correction factors is needed. Experimental reassessment is expensive and time consuming given the great variation between fuel assemblies in circulation. Fortunately current modeling methods enable relative response functions to be calculated with high accuracy. Hence modeling provides a more convenient and cost effective means to derive correction factors which are fit for purpose with confidence. In this work we use the Monte Carlo code MCNPX with neutron coincidence tallies to calculate the influence of Gd

  11. Regulated shedding of syndecan-1 and -4 ectodomains by thrombin and growth factor receptor activation.

    PubMed

    Subramanian, S V; Fitzgerald, M L; Bernfield, M

    1997-06-01

    The syndecan family of transmembrane heparan sulfate proteoglycans is abundant on the surface of all adherent mammalian cells. Syndecans bind and modify the action of various growth factors/cytokines, proteases/antiproteases, cell adhesion molecules, and extracellular matrix components. Syndecan expression is highly regulated during wound repair, a process orchestrated by many of these effectors. Each syndecan ectodomain is shed constitutively by cultured cells, but the mechanism and significance of this shedding are not understood. Therefore, we examined (i) whether physiological agents active during wound repair influence syndecan shedding, and (ii) whether wound fluids contain shed syndecan ectodomains. Using SVEC4-10 endothelial cells we find that certain proteases and growth factors accelerate shedding of the syndecan-1 and -4 ectodomains. Protease-accelerated shedding is completely inhibited by serum-containing media. Thrombin activity is duplicated by the 14-amino acid thrombin receptor agonist peptide that directly activates the thrombin receptor and is not inhibited by serum. Epidermal growth factor family members accelerate shedding but FGF-2, platelet-derived growth factor-AB, transforming growth factor-beta, tumor necrosis factor-alpha, and vascular endothelial cell growth factor 165 do not. Shed ectodomains are soluble, stable in the conditioned medium, have the same size core proteins regardless whether shed at a basal rate, or accelerated by thrombin or epidermal growth factor-family members and are found in acute human dermal wound fluids. Thus, shedding is accelerated by activation of at least two distinct receptor classes, G protein-coupled (thrombin) and protein tyrosine kinase (epidermal growth factor). Proteases and growth factors active during wound repair can accelerate syndecan shedding from cell surfaces. Regulated shedding of syndecans suggests physiological roles for the soluble proteoglycan ectodomains.

  12. The suppression of fibroblast growth factor 2/fibroblast growth factor 4-dependent tumour angiogenesis and growth by the anti-growth factor activity of dextran derivative (CMDB7).

    PubMed Central

    Bagheri-Yarmand, R.; Kourbali, Y.; Mabilat, C.; Morère, J. F.; Martin, A.; Lu, H.; Soria, C.; Jozefonvicz, J.; Crépin, M.

    1998-01-01

    Our previous studies showed that carboxymethyl benzylamide dextran (CMDB7) blocks basic fibroblast growth factor (FGF-2)-dependent cell proliferation of a human breast epithelial line (HBL100), suggesting its potential role as a potent antiangiogenic substance. The derived cell line (HH9), which was transformed with the hst/FGF4 gene, has been shown to be highly proliferative in vitro and to induce angiogenic tumours in nude mice. We show here that CMDB7 inhibits the mitogenic activities of the conditioned media from HBL 100 and HH9 cells in a dose-dependent manner. When HH9 cells were injected s.c. into nude mice, CMDB7 treatment (300 mg kg(-1) week(-1)) suppressed the tumour take and the tumour growth by about 50% and 80% respectively. Immunohistochemical analysis showed a highly significant decrease, by more than threefold, in the endothelial density of viable tumour regions, together with a significant increase in the necrosis area. This antiangiogenic activity of CMDB7 was further demonstrated by direct inhibition of calf pulmonary artery (CPAE) and human umbilical vein (HUVEC) endothelial cell proliferation and migration in vitro. In addition, we showed that CMDB7 inhibits specifically the mitogenic effects of the growth factors that bind to heparin such as FGF-2, FGF-4, platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGF-beta1), but not those of epidermal growth factor (EGF) and insulin-like growth factor (IGF-1). These results demonstrate that CMDB7 inhibits FGF-2/FGF-4-dependent tumour growth and angiogenesis, most likely by disrupting the autocrine and paracrine effects of growth factors released from the tumour cells. Images Figure 4 PMID:9662260

  13. Human-robot interaction: kinematics and muscle activity inside a powered compliant knee exoskeleton.

    PubMed

    Knaepen, Kristel; Beyl, Pieter; Duerinck, Saartje; Hagman, Friso; Lefeber, Dirk; Meeusen, Romain

    2014-11-01

    Until today it is not entirely clear how humans interact with automated gait rehabilitation devices and how we can, based on that interaction, maximize the effectiveness of these exoskeletons. The goal of this study was to gain knowledge on the human-robot interaction, in terms of kinematics and muscle activity, between a healthy human motor system and a powered knee exoskeleton (i.e., KNEXO). Therefore, temporal and spatial gait parameters, human joint kinematics, exoskeleton kinetics and muscle activity during four different walking trials in 10 healthy male subjects were studied. Healthy subjects can walk with KNEXO in patient-in-charge mode with some slight constraints in kinematics and muscle activity primarily due to inertia of the device. Yet, during robot-in-charge walking the muscular constraints are reversed by adding positive power to the leg swing, compensating in part this inertia. Next to that, KNEXO accurately records and replays the right knee kinematics meaning that subject-specific trajectories can be implemented as a target trajectory during assisted walking. No significant differences in the human response to the interaction with KNEXO in low and high compliant assistance could be pointed out. This is in contradiction with our hypothesis that muscle activity would decrease with increasing assistance. It seems that the differences between the parameter settings of low and high compliant control might not be sufficient to observe clear effects in healthy subjects. Moreover, we should take into account that KNEXO is a unilateral, 1 degree-of-freedom device. PMID:24846650

  14. Human-robot interaction: kinematics and muscle activity inside a powered compliant knee exoskeleton.

    PubMed

    Knaepen, Kristel; Beyl, Pieter; Duerinck, Saartje; Hagman, Friso; Lefeber, Dirk; Meeusen, Romain

    2014-11-01

    Until today it is not entirely clear how humans interact with automated gait rehabilitation devices and how we can, based on that interaction, maximize the effectiveness of these exoskeletons. The goal of this study was to gain knowledge on the human-robot interaction, in terms of kinematics and muscle activity, between a healthy human motor system and a powered knee exoskeleton (i.e., KNEXO). Therefore, temporal and spatial gait parameters, human joint kinematics, exoskeleton kinetics and muscle activity during four different walking trials in 10 healthy male subjects were studied. Healthy subjects can walk with KNEXO in patient-in-charge mode with some slight constraints in kinematics and muscle activity primarily due to inertia of the device. Yet, during robot-in-charge walking the muscular constraints are reversed by adding positive power to the leg swing, compensating in part this inertia. Next to that, KNEXO accurately records and replays the right knee kinematics meaning that subject-specific trajectories can be implemented as a target trajectory during assisted walking. No significant differences in the human response to the interaction with KNEXO in low and high compliant assistance could be pointed out. This is in contradiction with our hypothesis that muscle activity would decrease with increasing assistance. It seems that the differences between the parameter settings of low and high compliant control might not be sufficient to observe clear effects in healthy subjects. Moreover, we should take into account that KNEXO is a unilateral, 1 degree-of-freedom device.

  15. Transparent Stretchable Self-Powered Patchable Sensor Platform with Ultrasensitive Recognition of Human Activities.

    PubMed

    Hwang, Byeong-Ung; Lee, Ju-Hyuck; Trung, Tran Quang; Roh, Eun; Kim, Do-Il; Kim, Sang-Woo; Lee, Nae-Eung

    2015-09-22

    Monitoring of human activities can provide clinically relevant information pertaining to disease diagnostics, preventive medicine, care for patients with chronic diseases, rehabilitation, and prosthetics. The recognition of strains on human skin, induced by subtle movements of muscles in the internal organs, such as the esophagus and trachea, and the motion of joints, was demonstrated using a self-powered patchable strain sensor platform, composed on multifunctional nanocomposites of low-density silver nanowires with a conductive elastomer of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate/polyurethane, with high sensitivity, stretchability, and optical transparency. The ultra-low-power consumption of the sensor, integrated with both a supercapacitor and a triboelectric nanogenerator into a single transparent stretchable platform based on the same nanocomposites, results in a self-powered monitoring system for skin strain. The capability of the sensor to recognize a wide range of strain on skin has the potential for use in new areas of invisible stretchable electronics for human monitoring. A new type of transparent, stretchable, and ultrasensitive strain sensor based on a AgNW/PEDOT:PSS/PU nanocomposite was developed. The concept of a self-powered patchable sensor system integrated with a supercapacitor and a triboelectric nanogenerator that can be used universally as an autonomous invisible sensor system was used to detect the wide range of strain on human skin. PMID:26277994

  16. Occupational exposures during routine activities in coal-fueled power plants

    SciTech Connect

    Mona J. Bird; David L. MacIntosh; Phillip L. Williams

    2004-06-15

    Limited information is available on occupational exposures during routine, nonoutage work activities in coal-fueled power plants. This study evaluated occupational exposures to the principal contaminants in the facilities, including respirable dust (coal dust), arsenic, noise, asbestos, and heat stress. The data were collected over a 3-month period, during the summer of 2001, in 5 representative power plants of a large southeastern power-generating company. From 4 of the 5 facilities, 392 air samples and 302 noise samples were collected with approximately 50 respirable coal dust, 32 arsenic, 15 asbestos, and 70 noise samples from each of the 4 plants. One of the previously surveyed facilities was also evaluated for heat stress, and 1 additional coal-fueled power plant was surveyed for a total of 20 personal heat stress samples. Of the nearly 400 air samples collected, only 1 exceeded the allowable occupational exposure value. For the noise samples, 55 were equal to or greater than the Occupational Safety and Health Administration (OSHA) 8-hour hearing conservation program level of 85 dBA, and 12 were equal to or greater than the OSHA 8-hour permissible exposure level of 90 dBA. The data concluded that some work sites were above the heat stress ceiling values recommended by the National Institute for Occupational Safety and Health (NIOSH). Four of the 20 employees personally monitored exceeded the recommended limits for heart rate or body core temperature.

  17. High-average-power actively-mode-locked Tm3+ fiber lasers

    NASA Astrophysics Data System (ADS)

    Eckerle, Michael; Kieleck, Christelle; Hübner, Philipp; Świderski, Jacek; Jackson, Stuart D.; Mazé, Gwenael; Eichhorn, Marc

    2012-02-01

    Fiber lasers emitting in the 2 μm wavelength range doped with thulium ions can be used as highly efficient pump sources for nonlinear converters to generate mid-infrared radiation. For spectroscopic purposes, illumination and countermeasures, a broad mid-infrared emission spectrum is advantageous. This can be reached by supercontinuum generation in fibers, e.g. fluoride fibers, which up to now has, however, only been presented with either low average power, complex Raman-shifted 1.55 μm pump sources or multi-stage amplifier pump schemes. Here we present recent results of a new actively-mode-locked single-oscillator scheme that can provide the high-repetition rate sub-ns pump pulses needed for pumping supercontinuum generators. A thulium-doped silica fiber laser is presented that provides > 11 W of average power CW-mode-locked pulses at 38 MHz repetition rate at ~ 38 ps pulse width. Upgrading the setup to allow Q-switched mode-locked operation yields mode-locked 40 MHz pulses arranged in 60 kHz bunched Q-switch envelopes and thus increases further the available peak power. In this Q-switched mode-locked regime over 5 W of average power has been achieved.

  18. Discrepancy between tissue factor activity and tissue factor expression in endotoxin-induced monocytes is associated with apoptosis and necrosis.

    PubMed

    Henriksson, Carola E; Klingenberg, Olav; Ovstebø, Reidun; Joø, Gun-Britt; Westvik, Ase-Brit; Kierulf, Peter

    2005-12-01

    Tissue factor (TF), the main initiator of blood coagulation, contributes to the manifestation of disseminated intravascular coagulation following septic shock in meningococcal infection. Since a direct relationship between disease severity and lipopolysaccharide (LPS) concentration in the circulation has been shown, we hypothesized that the procoagulant and cytotoxic effects of endotoxin also in vitro were related to its concentration. In vitro studies, however, have frequently used much higher LPS concentrations than those observed in clinical samples. Using elutriation-purified human monocytes, we observed that LPS up to 1000 ng/ml exerted a concentration-dependent increase in TF activity (tenase activity, fibrin formation in plasma). Although there was a dose-dependent increase in TF activity, there was not a concomitant increase in TF expression at LPS concentrations above 1 ng/ml (flow cytometry, Western blotting, TF mRNA). Flow cytometry revealed that this discrepancy between TF activity and TF expression at endotoxin concentrations above 1 ng/ml, coincided with an LPS dose-dependent increase in cell surface phosphatidylserine (PS), considered to promote coagulation. The increased PS expression was associated with an increased number of 7-AAD-positive cells indicating cell death. We conclude that enhancement of monocyte procoagulant activity in vitro by high concentrations of LPS may result from increased PS exposure due to apoptosis and necrosis. Therefore, the LPS concentrations used to examine monocyte procoagulant activity in vitro, should be carefully chosen.

  19. Cln3-associated kinase activity in Saccharomyces cerevisiae is regulated by the mating factor pathway.

    PubMed

    Jeoung, D I; Oehlen, L J; Cross, F R

    1998-01-01

    The Saccharomyces cerevisiae cell cycle is arrested in G1 phase by the mating factor pathway. Genetic evidence has suggested that the G1 cyclins Cln1, Cln2, and Cln3 are targets of this pathway whose inhibition results in G1 arrest. Inhibition of Cln1- and Cln2-associated kinase activity by the mating factor pathway acting through Far1 has been described. Here we report that Cln3-associated kinase activity is inhibited by mating factor treatment, with dose response and timing consistent with involvement in cell cycle arrest. No regulation of Cln3-associated kinase was observed in a fus3 kss1 strain deficient in mating factor pathway mitogen-activated protein (MAP) kinases. Inhibition occurs mainly at the level of specific activity of Cln3-Cdc28 complexes. Inhibition of the C-terminally truncated Cln3-1-associated kinase is not observed; such truncations were previously identified genetically as causing resistance to mating factor-induced cell cycle arrest. Regulation of Cln3-associated kinase specific activity by mating factor treatment requires Far1. Overexpression of Far1 restores inhibition of C-terminally truncated Cln3-1-associated kinase activity. G2/M-arrested cells are unable to regulate Cln3-associated kinase, possibly because of cell cycle regulation of Far1 abundance. Inhibition of Cln3-associated kinase activity by the mating factor pathway may allow this pathway to block the earliest step in normal cell cycle initiation, since Cln3 functions as the most upstream G1-acting cyclin, activating transcription of the G1 cyclins CLN1 and CLN2 as well as of the S-phase cyclins CLB5 and CLB6. PMID:9418890

  20. Streptococcus pyogenes CAMP factor attenuates phagocytic activity of RAW 264.7 cells.

    PubMed

    Kurosawa, Mie; Oda, Masataka; Domon, Hisanori; Saitoh, Issei; Hayasaki, Haruaki; Terao, Yutaka

    2016-02-01

    Streptococcus pyogenes produces molecules that inhibit the function of human immune system, thus allowing the pathogen to grow and spread in tissues. It is known that S. pyogenes CAMP factor increases erythrocytosis induced by Staphylococcus aureus β-hemolysin. However, the effects of CAMP factor for immune cells are unclear. In this study, we investigated the effects of CAMP factor to macrophages. Western blotting analysis demonstrated that all examined strains expressed CAMP factor protein. In the presence of calcium or magnesium ion, CAMP factor was significantly released in the supernatant. In addition, both culture supernatant from S. pyogenes strain SSI-9 and recombinant CAMP factor dose-dependently induced vacuolation in RAW 264.7 cells, but the culture supernatant from Δcfa isogenic mutant strain did not. CAMP factor formed oligomers in RAW 264.7 cells in a time-dependent manner. CAMP factor suppressed cell proliferation via G2 phase cell cycle arrest without inducing cell death. Furthermore, CAMP factor reduced the uptake of S. pyogenes and phagocytic activity indicator by RAW 264.7 cells. These results suggest that CAMP factor works as a macrophage dysfunction factor. Therefore, we conclude that CAMP factor allows S. pyogenes to escape the host immune system, and contribute to the spread of streptococcal infection.