Science.gov

Sample records for active power loss

  1. Dielectric loss against piezoelectric power harvesting

    NASA Astrophysics Data System (ADS)

    Liang, Junrui; Shu-Hung Chung, Henry; Liao, Wei-Hsin

    2014-09-01

    Piezoelectricity is one of the most popular electromechanical transduction mechanisms for constructing kinetic energy harvesting systems. When a standard energy harvesting (SEH) interface circuit, i.e., bridge rectifier plus filter capacitor, is utilized for collecting piezoelectric power, the previous literature showed that the power conversion can be well predicted without much consideration for the effect of dielectric loss. Yet, as the conversion power gets higher by adopting power-boosting interface circuits, such as synchronized switch harvesting on inductor (SSHI), the neglect of dielectric loss might give rise to deviation in harvested power estimation. Given the continuous progress on power-boosting interface circuits, the role of dielectric loss in practical piezoelectric energy harvesting (PEH) systems should receive attention with better evaluation. Based on the integrated equivalent impedance network model, this fast track communication provides a comprehensive study on the susceptibility of harvested power in PEH systems under different conditions. It shows that, dielectric loss always counteracts piezoelectric power harvesting by causing charge leakage across piezoelectric capacitance. In particular, taking corresponding ideal lossless cases as references, the counteractive effect might be aggravated under one of the five conditions: larger dielectric loss tangent, lower vibration frequency, further away from resonance, weaker electromechanical coupling, or using power-boosting interface circuit. These relationships are valuable for the study of PEH systems, as they not only help explain the role of dielectric loss in piezoelectric power harvesting, but also add complementary insights for material, structure, excitation, and circuit considerations towards holistic evaluation and design for practical PEH systems.

  2. power loss in SSPX

    NASA Astrophysics Data System (ADS)

    Stewart, T. L.; Romero-Talamas, C. A.; McLean, H. S.; Correll, D. L.

    2007-11-01

    An absolute calibration has been performed on each of the seven chords of the Hα diagnostic [Z. Wang, G.A. Wurden, C.W Barnes, et al., Rev. Sci. Instrum. 72, 1059 (2001)] at SSPX. Simple models are used to estimate the total power lost to Hα radiation throughout experimental shots. Using these models, high energy shots (Te > 500 eV) are compared to low energy shots.

  3. Minimum loss power flow in hydro thermal electric power systems based on Kron's loss formula

    SciTech Connect

    Ravindranath, K.M.; El-Hawary, M.E.

    1989-01-01

    The authors discuss the formulation of the optimal minimum loss hydro-thermal power flow problem in electric power systems on the basis of Kron's loss formula as the objective function. Results of computational experience with a Newton's iterative implementation using two standard test systems. The conclusion is that it is extremely important to have an accurate loss model representation due to the potential errors as well as slow and difficult convergence behavior of the process.

  4. Loss of 115 kV Power

    SciTech Connect

    Smith, J.A.

    2001-08-22

    This report discusses the postulated loss of 115 kV power. Continuous electrical power to Savannah River Plant reactors is necessary to maintain water flow for heat removal and essential monitoring and control. Should power supplied to the plant 115 kV system from offsite be lost, on-site generation is sufficient to maintain all reactors in a safe shutdown mode for an indefinite period. Should on-site generators for the 115 kV grid also be lost, diesel-electric generators within each reactor building are also sufficient to maintain safe shutdown for a finite period. In all cases DC power for necessary monitoring and control would be available from battery systems with AC converter backup.

  5. Linguistic Model for Engine Power Loss

    DTIC Science & Technology

    2011-11-27

    model, engine power loss, intelligent diagnostics 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Public Release 18. NUMBER OF PAGES...module via a wireless interface that is compliant with the IEEE 802.15 protocol. The wireless personal area network is implemented using the ZigBee ... secure short range wireless communications link, or via a wired Ethernet port to a mobile device (e.g., another laptop computer authorized for CBM

  6. Exercise and activity for weight loss

    MedlinePlus

    Weight loss - activity; Weight loss - exercise; Obesity - activity ... Calories used in exercise > calories eaten = weight loss. This means that to lose weight, the number of calories you burn by exercising needs ...

  7. The Unseen Power Loss: Stemming the Flow.

    ERIC Educational Resources Information Center

    Gillett, Raphael

    2002-01-01

    Outlined an estimate-substitution strategy for a test comparing two means and developed an expected-power formula for the test. Demonstrated that for empirically representative distributions of effect size in psychology, the expected power deficit is large. (SLD)

  8. Convective contributions to local power loss in a Bumpy Torus

    SciTech Connect

    Hiroe, S.; Haste, G.R. Jr.; Tolliver, J.S.; Quon, B.H.; Goyer, J.R.; Solensten, L.; Conner, K.A.

    1986-12-01

    Power flow in the ELMO Bumpy Torus (Plasma Physics and Controlled Nuclear Fusion Research (Tokyo, 1974) (IAEA, Vienna, 1975) Vol. 2, p. 141; Plasma Phys. 25, 597 (1983)) was investigated by measuring the power received by a limiter. Selective removal of heating power from various cavities, including the cavity with the limiter, has demonstrated that the majority of the power is lost locally. Observations of the potential structure demonstrate that asymmetric potential contours are present which can lead to enhanced plasma loss.

  9. Energy loss analysis of an integrated space power distribution system

    NASA Technical Reports Server (NTRS)

    Kankam, M. D.; Ribeiro, P. F.

    1992-01-01

    The results of studies related to conceptual topologies of an integrated utility-like space power system are described. The system topologies are comparatively analyzed by considering their transmission energy losses as functions of mainly distribution voltage level and load composition. The analysis is expedited by use of a Distribution System Analysis and Simulation (DSAS) software. This recently developed computer program by the Electric Power Research Institute (EPRI) uses improved load models to solve the power flow within the system. However, present shortcomings of the software with regard to space applications, and incompletely defined characteristics of a space power system make the results applicable to only the fundamental trends of energy losses of the topologies studied. Accountability, such as included, for the effects of the various parameters on the system performance can constitute part of a planning tool for a space power distribution system.

  10. Forecasting photovoltaic array power production subject to mismatch losses

    SciTech Connect

    Picault, D.; Raison, B.; Bacha, S.; de la Casa, J.; Aguilera, J.

    2010-07-15

    The development of photovoltaic (PV) energy throughout the world this last decade has brought to light the presence of module mismatch losses in most PV applications. Such power losses, mainly occasioned by partial shading of arrays and differences in PV modules, can be reduced by changing module interconnections of a solar array. This paper presents a novel method to forecast existing PV array production in diverse environmental conditions. In this approach, field measurement data is used to identify module parameters once and for all. The proposed method simulates PV arrays with adaptable module interconnection schemes in order to reduce mismatch losses. The model has been validated by experimental results taken on a 2.2 kW{sub p} plant, with three different interconnection schemes, which show reliable power production forecast precision in both partially shaded and normal operating conditions. Field measurements show interest in using alternative plant configurations in PV systems for decreasing module mismatch losses. (author)

  11. Passive magnetic bearing element with minimal power losses

    DOEpatents

    Post, Richard F.

    1998-01-01

    Systems employing passive magnetic bearing elements having minimal power losses are provided. Improved stabilizing elements are shown, employing periodic magnet arrays and inductively loaded circuits, but with improved characteristics compared to the elements disclosed in U.S. Patent No. 5,495,221 entitled "Dynamically Stable Magnetic Suspension/Bearing System." The improvements relate to increasing the magnitude of the force derivative, while at the same time reducing the power dissipated during the normal operation of the bearing system, to provide a passive bearing system that has virtually no losses under equilibrium conditions, that is, when the supported system is not subject to any accelerations except those of gravity.

  12. Passive magnetic bearing element with minimal power losses

    DOEpatents

    Post, R.F.

    1998-12-08

    Systems employing passive magnetic bearing elements having minimal power losses are provided. Improved stabilizing elements are shown, employing periodic magnet arrays and inductively loaded circuits, but with improved characteristics compared to the elements disclosed in US Patent No. 5,495,221 entitled ``Dynamically Stable Magnetic Suspension/Bearing System.`` The improvements relate to increasing the magnitude of the force derivative, while at the same time reducing the power dissipated during the normal operation of the bearing system, to provide a passive bearing system that has virtually no losses under equilibrium conditions, that is, when the supported system is not subject to any accelerations except those of gravity. 8 figs.

  13. Power loss in electrical steel under elliptically rotating flux conditions

    SciTech Connect

    Salz, W.; Hempel, K.A.

    1996-03-01

    The power loss of electrical steel sheet given in the data sheets of the steel manufacturers is related to linearly alternating flux conditions, measured with an Epstein frame or a single sheet tester, respectively. In the application of the material in electrical machines, the authors find large areas with rotational flux conditions, i.e., in the T-joint region of three-phase power transformers or above the stator teeth of three-phase motors and generators. The most general description of the magnetization process in this case is an elliptically rotating flux. The paper outlines the magnetic behavior of steel sheet under these flux conditions, and finally defines a simple method to predict the total power loss under elliptically rotating flux from data measured under linearly alternating and circularly rotating flux conditions only.

  14. Power losses in PWM-VSI inverter using NPT or PT IGBT devices

    SciTech Connect

    Blaabjerg, F.; Munk-Nielsen, S.; Pedersen, J.K.; Jaeger, U.

    1995-05-01

    This paper investigates the power losses for two different IGBT technologies (Non Punch Through and Punch Through) for use in PWM-VSI inverters in order to choose the right device technology for a given application. A loss model of the inverter is developed based on experimental determination of the power losses. The loss model is used on two different modulation strategies which are a sine wave with a third harmonic added and a 60{degree}-PWM modulation where only two inverterlegs are active at the same time. The two IGBT technologies are characterized on an advanced measurement system which is described. The total power losses in the inverter are estimated simulation at different conditions and it is concluded that the Non Punch Through technology is most useful for higher switching frequencies, while the Punch Through technology is special useful at lower switching frequencies and high load currents. It is also concluded the 60{degree}-PWM modulation has the lowest power losses and the power losses are almost independent of phase angle cos({phi}) for normal motor operation.

  15. Minimization of the Ohmic Loss of Grooved Polarizer Mirrors in High-Power ECRH Systems

    NASA Astrophysics Data System (ADS)

    Wagner, D.; Leuterer, F.; Kasparek, W.; Stober, J.

    2017-02-01

    A set of two corrugated polarizer mirrors is typically used in high-power electron cyclotron resonance heating (ECRH) systems to provide the required polarization of the ECRH output beam. The ohmic losses of these mirrors can significantly exceed the losses of plane mirrors depending on the polarization of the incident beam with respect to the orientation of the grooves. Since polarizer mirrors incorporated into miter bends of a corrugated waveguide line are limited in size, active water cooling can become critical in high-power cw systems like the one for ITER. The ohmic loss of polarizer mirrors has been investigated experimentally at high power. A strategy to minimize the losses for given mirror geometries has been found.

  16. Helicopter optimal descent and landing after power loss

    NASA Technical Reports Server (NTRS)

    Johnson, W.

    1977-01-01

    An optimal control solution is obtained for the descent and landing of a helicopter after the loss of power in level flight. The model considers the helicopter vertical velocity, horizontal velocity, and rotor speed; and it includes representations of ground effect, rotor inflow time lag, pilot reaction time, rotor stall, and the induced velocity curve in the vortex ring state. The control (rotor thrust magnitude and direction) required to minimize the vertical and horizontal velocity at contact with the ground is obtained using nonlinear optimal control theory. It is found that the optimal descent after power loss in hover is a purely vertical flight path. Good correlation, even quantitatively, is found between the calculations and (non-optimal) flight test results.

  17. Flux-transfer losses in helically wound superconducting power cables

    SciTech Connect

    Clem, John R; Malozemoff, A P

    2013-06-25

    Minimization of ac losses is essential for economic operation of high-temperature superconductor (HTS) ac power cables. A favorable configuration for the phase conductor of such cables has two counter-wound layers of HTS tape-shaped wires lying next to each other and helically wound around a flexible cylindrical former. However, if magnetic materials such as magnetic substrates of the tapes lie between the two layers, or if the winding pitch angles are not opposite and essentially equal in magnitude to each other, current distributes unequally between the two layers. Then, if at some point in the ac cycle the current of either of the two layers exceeds its critical current, a large ac loss arises from the transfer of flux between the two layers. A detailed review of the formalism, and its application to the case of paramagnetic substrates including the calculation of this flux-transfer loss, is presented.

  18. Aromatase Activity and Bone Loss in Men

    PubMed Central

    Merlotti, Daniela; Gennari, Luigi; Stolakis, Konstantinos; Nuti, Ranuccio

    2011-01-01

    Aromatase is a specific component of the cytochrome P450 enzyme system responsible for the transformation of androgen precursors into estrogens. This enzyme is encoded by the CYP19A1 gene located at chromosome 15q21.2, that is, expressed in ovary and testis, but also in many extraglandular sites such as the placenta, brain, adipose tissue, and bone. The activity of aromatase regulates the concentrations of estrogens with endocrine, paracrine, and autocrine effects on target issues including bone. Importantly, extraglandular aromatization of circulating androgen precursors is the major source of estrogen in men. Clinical and experimental evidences clearly indicate that aromatase activity and estrogen production are necessary for longitudinal bone growth, the attainment of peak bone mass, pubertal growth spurt, epiphyseal closure, and normal bone remodeling in young individuals. Moreover, with aging, individual differences in aromatase activity may significantly affect bone loss and fracture risk in men. PMID:21772971

  19. Ice Accretion Prediction on Wind Turbines and Consequent Power Losses

    NASA Astrophysics Data System (ADS)

    Yirtici, Ozcan; Tuncer, Ismail H.; Ozgen, Serkan

    2016-09-01

    Ice accretion on wind turbine blades modifies the sectional profiles and causes alteration in the aerodynamic characteristic of the blades. The objective of this study is to determine performance losses on wind turbines due to the formation of ice in cold climate regions and mountainous areas where wind energy resources are found. In this study, the Blade Element Momentum method is employed together with an ice accretion prediction tool in order to estimate the ice build-up on wind turbine blades and the energy production for iced and clean blades. The predicted ice shapes of the various airfoil profiles are validated with the experimental data and it is shown that the tool developed is promising to be used in the prediction of power production losses of wind turbines.

  20. Sleep Loss Activates Cellular Inflammatory Signaling

    PubMed Central

    Irwin, Michael R.; Wang, Minge; Ribeiro, Denise; Cho, Hyong Jin; Olmstead, Richard; Breen, Elizabeth Crabb; Martinez-Maza, Otoniel; Cole, Steve

    2008-01-01

    Background Accumulating evidence suggests that sleep disturbance is associated with inflammation and related disorders including cardiovascular disease, arthritis, and diabetes mellitus. This study was undertaken to test the effects of sleep loss on activation of nuclear factor (NF) -κB, a transcription factor that serves a critical role in the inflammatory signaling cascade. Methods In 14 healthy adults (7 females; 7 males), peripheral blood mononuclear cell NF-κB was repeatedly assessed, along with enumeration of lymphocyte subpopulations, in the morning after baseline sleep, partial sleep deprivation (awake from 23:00 h to 03:00 h), and recovery sleep. Results In the morning after a night of sleep loss, mononuclear cell NF-κB activation was significantly greater compared with morning levels following uninterrupted baseline or recovery sleep, in which the response was found in females but not in males. Conclusions These results identify NF-κB activation as a molecular pathway by which sleep disturbance may influence leukocyte inflammatory gene expression and the risk of inflammation-related disease. PMID:18561896

  1. Evaluation of Loss of Offsite Power Events at Nuclear Power Plants: 1980 - 1996

    SciTech Connect

    C. L. Atwood; D. A. Prawdzik; D. L. Kelly; F. M. Marshall; J. W. Stetkar

    1999-08-01

    It is recognized that the availability of AC power to commercial nuclear power plants is essential for safe operations and accident recovery. A loss of offsite power (LOSP) event, therefore, is considered an important contributor to total risk at nuclear power plants. In 1988, the U. S. Nuclear Regulatory Commission published NUREG-1032 to report on an evaluation of the risk from actual LOSP events that had occurred at nuclear power plants within the United States up through 1985. This paper summarizes a similar study, whose primary objective was to update the LOSP model parameters, frequency and recovery time, using power plant event data from 1980-1996, published as NUREG/CR-5496 in 1998. An additional objective of the study is to re-examine the engineering insights concerning LOSP events.

  2. Power loss measurement of implantable wireless power transfer components using a Peltier device balance calorimeter

    NASA Astrophysics Data System (ADS)

    Leung, Ho Yan; Budgett, David M.; Taberner, Andrew; Hu, Patrick

    2014-09-01

    Determining heat losses in power transfer components operating at high frequencies for implantable inductive power transfer systems is important for assessing whether the heat dissipated by the component is acceptable for implantation and medical use. However, this is a challenge at high frequencies and voltages due to limitations in electronic instrumentation. Calorimetric methods of power measurement are immune to the effects of high frequencies and voltages; hence, the measurement is independent of the electrical characteristics of the system. Calorimeters have been widely used to measure the losses of high power electrical components (>50 W), however it is more difficult to perform on low power components. This paper presents a novel power measurement method for components dissipating anywhere between 0.2 W and 1 W of power based on a heat balance calorimeter that uses a Peltier device as a balance sensor. The proposed balance calorimeter has a single test accuracy of ±0.042 W. The experimental results revealed that there was up to 35% difference between the power measurements obtained with electrical methods and the proposed calorimeter.

  3. Lower hybrid wave edge power loss quantification on the Alcator C-Mod tokamak

    NASA Astrophysics Data System (ADS)

    Faust, I. C.; Brunner, D.; LaBombard, B.; Parker, R. R.; Terry, J. L.; Whyte, D. G.; Baek, S. G.; Edlund, E.; Hubbard, A. E.; Hughes, J. W.; Kuang, A. Q.; Reinke, M. L.; Shiraiwa, S.; Wallace, G. M.; Walk, J. R.

    2016-05-01

    For the first time, the power deposition of lower hybrid RF waves into the edge plasma of a diverted tokamak has been systematically quantified. Edge deposition represents a parasitic loss of power that can greatly impact the use and efficiency of Lower Hybrid Current Drive (LHCD) at reactor-relevant densities. Through the use of a unique set of fast time resolution edge diagnostics, including innovative fast-thermocouples, an extensive set of Langmuir probes, and a Lyα ionization camera, the toroidal, poloidal, and radial structure of the power deposition has been simultaneously determined. Power modulation was used to directly isolate the RF effects due to the prompt ( t < τ E ) response of the scrape-off-layer (SOL) plasma to Lower Hybrid Radiofrequency (LHRF) power. LHRF power was found to absorb more strongly in the edge at higher densities. It is found that a majority of this edge-deposited power is promptly conducted to the divertor. This correlates with the loss of current drive efficiency at high density previously observed on Alcator C-Mod, and displaying characteristics that contrast with the local RF edge absorption seen on other tokamaks. Measurements of ionization in the active divertor show dramatic changes due to LHRF power, implying that divertor region can be a key for the LHRF edge power deposition physics. These observations support the existence of a loss mechanism near the edge for LHRF at high density ( n e > 1.0 × 10 20 (m-3)). Results will be shown addressing the distribution of power within the SOL, including the toroidal symmetry and radial distribution. These characteristics are important for deducing the cause of the reduced LHCD efficiency at high density and motivate the tailoring of wave propagation to minimize SOL interaction, for example, through the use of high-field-side launch.

  4. LH Power Losses In Front of the JET Launcher

    SciTech Connect

    Jacquet, P.; Arnoux, G.; Kirov, K.; Mailloux, J.; Mayoral, M.-L.; Ongena, J.

    2009-11-26

    In recent JET experiments, Lower Hybrid (LH) power losses in the Scrape-Off Layer (SOL) were characterized using infra-red (IR) thermography. Hot spots were observed on objects intercepting the field lines passing in front of the LH launcher, i.e. on poloidal limiters and on dumplates located at the top of the tokamak; their locations being in good agreement with magnetic field line tracing using the EFIT equilibrium code. The dumplate temperature was monitored while scanning the launcher position so that the radial distance between field lines intercepting the hot spots and the launcher was increased up to 3.5 cm. The dissipation layer in front of the launcher was estimated to be at least 3.5 cm wide, in agreement with recent measurements on Tore-Supra, but not with simple models that predict a dissipation layer in the mm range.

  5. LH Power Losses In Front of the JET Launcher

    NASA Astrophysics Data System (ADS)

    Jacquet, P.; Arnoux, G.; Colas, L.; Delpech, L.; Ekedahl, A.; Frigione, D.; Goniche, M.; Kirov, K.; Leguen, F.; Mailloux, J.; Mayoral, M.-L.; Ongena, J.; Petrzilka, V.; Portafaix, C.; Rimini, F.

    2009-11-01

    In recent JET experiments, Lower Hybrid (LH) power losses in the Scrape-Off Layer (SOL) were characterized using infra-red (IR) thermography. Hot spots were observed on objects intercepting the field lines passing in front of the LH launcher, i.e. on poloidal limiters and on dumplates located at the top of the tokamak; their locations being in good agreement with magnetic field line tracing using the EFIT equilibrium code. The dumplate temperature was monitored while scanning the launcher position so that the radial distance between field lines intercepting the hot spots and the launcher was increased up to 3.5 cm. The dissipation layer in front of the launcher was estimated to be at least 3.5 cm wide, in agreement with recent measurements on Tore-Supra, but not with simple models that predict a dissipation layer in the mm range.

  6. Cleaning ability and induced dentin loss of a magnetostrictive ultrasonic instrument at different power settings.

    PubMed

    Lampe Bless, Kathrin; Sener, Beatrice; Dual, Jürg; Attin, Thomas; Schmidlin, Patrick R

    2011-04-01

    Some laboratory studies have evaluated the oscillation mode of ultrasonic scalers. None of them recorded its influence on calculus removal and quantified dental hard tissue loss. This study aimed to compare the performance of a magnetostrictive ultrasonic instrument at different power settings in vitro in relation to the tip oscillation activity. The oscillation activity of the straight Slimline® insert in the Cavitron® ultrasonic scaling device was analyzed at five different power settings with the help of two laser vibrometers. The performance of this instrument was tested on 60 roots of human single-rooted teeth. Twelve roots each were randomly assigned to be instrumented at a given power setting. Every root was instrumented for 120 s at a standardized instrumentation force of 0.1 ± 0.05 N. In addition, another 30 periodontally involved roots with subgingival calculus were instrumented accordingly to assess the calculus removal potential. The surface characteristics after instrumentation were analyzed under scanning electron microscope. The instrumentation at minimum power setting resulted in an mean increase of the root surface roughness of 0.18 ± 0.28 compared to 0.51 ± 0.48 at maximum power setting (P = 0.0327). The loss of dental hard tissue amounted to 11.37 ± 3.64 at minimum compared to 23.37 ± 15.76 at maximum power (P = 0.0010). The higher the power setting, the more calculus was removed. The values of the latter ranged between 4.04 ± 1.87 and 11.26 ± 4.66 mm² of cleaned dentin surface area (P = 0.0065). At lower power settings, a more favorable relation between cleaning ability, loss of dentine, and surface roughness was found.

  7. Analysis of Power Converter Losses in Vector Control System of a Self-Excited Induction Generator

    NASA Astrophysics Data System (ADS)

    Bašić, Mateo; Vukadinović, Dinko; Polić, Miljenko

    2014-03-01

    This paper provides analysis of losses in the hysteresis-driven three-phase power converter with IGBTs and free-wheeling diodes. The converter under consideration is part of the self-excited induction generator (SEIG) vector control system. For the analysis, the SEIG vector control system is used in which the induction generator iron losses are taken into account. The power converter losses are determined by using a suitable loss estimation algorithm reported in literature. The chosen algorithm allows the power converter losses to be determined both by type (switching/conduction losses) and by converter component (IGBT/diode losses). The overall power converter losses are determined over wide ranges of rotor speed, dc-link voltage and load resistance, and subsequently used for offline correction of the overall control system's losses (efficiency) obtained through control system simulations with an ideal power converter. The control system's efficiency values obtained after the correction are compared with the measured values.

  8. Continued Investigation of Leakage and Power Loss Test Results for Competing Turbine Engine Seals

    NASA Technical Reports Server (NTRS)

    Delgado, Irebert R.; Proctor, Margaret P.

    2007-01-01

    Seal leakage decreases with increasing surface speed due to reduced clearances from disk centrifugal growth. Annular and labyrinth seal leakage are 2-3 times greater than brush and finger seal leakage. Seal leakage rates increase with increasing temperature because of seal clearance growth due to different coefficients of thermal expansion between the seal and test disk. Seal power loss is not strongly affected by inlet temperature. Seal power loss increases with increasing surface speed, seal pressure differential, mass flow rate or flow factor, and radial clearance. The brush and finger seals had nearly the same power loss. Annular and labyrinth seal power loss were higher than finger or brush seal power loss. The brush seal power loss was the lowest and 15-30% lower than annular and labyrinth seal power loss.

  9. Specific loss power in superparamagnetic hyperthermia: nanofluid versus composite

    NASA Astrophysics Data System (ADS)

    Osaci, M.; Cacciola, M.

    2017-01-01

    Currently, the magnetic hyperthermia induced by nanoparticles is of great interest in biomedical applications. In the literature, we can find a lot of models for magnetic hyperthermia, but many of them do not give importance to a significant detail, such as the geometry of nanoparticle positions in the system. Usually, a nanofluid is treated by considering random positions of the nanoparticles, geometry that is actually characteristic to the composite nanoparticles. To assess the error which is frequently made, in this paper we propose a comparative analysis between the specific loss power (SLP) in case of a nanofluid and the SLP in case of a composite with magnetic nanoparticles. We are going to use a superparamagnetic hyperthermia model based on the improved model for calculating the Néel relaxation time in a magnetic field oblique to the nanoparticle magnetic anisotropy axes, and on the improved theoretical model LRT (linear response theory) for SLP. To generate the nanoparticle geometry in the system, we are going to apply a Monte Carlo method to a nanofluid, by minimising the interaction potentials in liquid medium and, for a composite environment, a method for generating random positions of the nanoparticles in a given volume.

  10. Efficiency and power loss in d. c. chopper circuits. [Theoretical calculation

    SciTech Connect

    Beck, M.O.

    1981-01-01

    The object of this paper was to investigate the efficiency and source of power losses of various classes of dc chopper circuits. The study involved a theoretical calculation of the power losses, supported by a considerable amount of practical work on full power-rated traction motor test bed. 3 refs.

  11. Analysis of Loss-of-Offsite-Power Events 1998–2013

    SciTech Connect

    Schroeder, John Alton

    2015-02-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses suggest that loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience during calendar years 1997 through 2013. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The emergency diesel generator failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. No statistically significant trends in LOOP frequencies over the 1997–2013 period are identified. There is a possibility that a significant trend in grid-related LOOP frequency exists that is not easily detected by a simple analysis. Statistically significant increases in recovery times after grid- and switchyard-related LOOPs are identified.

  12. Analysis of Loss-of-Offsite-Power Events 1998–2012

    SciTech Connect

    T. E. Wierman

    2013-10-01

    Loss of offsite power (LOOP) can have a major negative impact on a power plant’s ability to achieve and maintain safe shutdown conditions. Risk analyses performed loss of all alternating current power contributes over 70% of the overall risk at some U.S. nuclear plants. LOOP event and subsequent restoration of offsite power are important inputs to plant probabilistic risk assessments. This report presents a statistical and engineering analysis of LOOP frequencies and durations at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience from fiscal year 1998 through 2012. Frequencies and durations were determined for four event categories: plant-centered, switchyard-centered, grid-related, and weather-related. The EDG failure modes considered are failure to start, failure to load and run, and failure to run more than 1 hour. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. A statistically significant increase in industry performance was identified for plant-centered and switchyard-centered LOOP frequencies. There is no statistically significant trend in LOOP durations.

  13. Shortening-induced torque depression in old men: implications for age-related power loss.

    PubMed

    Power, Geoffrey A; Makrakos, Demetri P; Stevens, Daniel E; Herzog, Walter; Rice, Charles L; Vandervoort, Anthony A

    2014-09-01

    Following active muscle shortening, the steady-state isometric torque at the final muscle length is lower than the steady-state torque obtained for a purely isometric contraction at that same final muscle length. This well-documented property of skeletal muscle is termed shortening-induced torque depression (TD). Despite many investigations into the mechanisms of weakness and power loss in old age, the influence of muscle shortening on the history dependence of isometric torque production remains to be elucidated. Thus, it is unclear whether older adults are disadvantaged for torque and power production following a dynamic shortening contraction. The purpose of this study was to evaluate shortening-induced TD in older adults, and to determine whether shortening-induced TD is related to power loss. Maximal voluntary isometric dorsiflexion contractions (MVC; 10s) in 8 young (25.5±3.7years) and 9 old (76.1±5.4years) men were performed on a HUMAC NORM dynamometer as a reference, and then again following an active shortening of 40° joint excursion (40°PF-0°PF) at angular velocities of 15°/s and 120°/s. Work and instantaneous power were derived during shortening. Shortening-induced TD was calculated and expressed as a percentage by determining the mean torque value over 1s during the isometric steady state of the MVC following shortening, divided by the mean torque value for the same 1s time period during the isometric reference MVC. To assess muscle activation, electromyography (root mean square; EMGRMS) of the tibialis anterior (TA) and soleus (SOL) was calculated at identical time points used in assessing shortening-induced TD, and voluntary activation (VA) was assessed using the interpolated twitch technique. Old were 18% weaker than young for MVC, and ~40% less powerful for 15°/s and 120°/s of shortening. Old produced 37% and 21% less work for 15°/s and 120°/s than young, respectively. Furthermore, old experienced 60% and 70% greater shortening-induced TD

  14. Characterization and Mitigation of Resistive Losses in a Large Area Laser Power Converter

    DTIC Science & Technology

    2014-03-27

    CHARACTERIZATION AND MITIGATION OF RESISTIVE LOSSES IN A LARGE AREA LASER POWER CONVERTER THESIS Eli A. Garduño, Second Lieutenant, USAF AFIT-ENP-14...LOSSES IN A LARGE AREA LASER POWER CONVERTER THESIS Presented to the Faculty Department of Engineering Physics Graduate School of Engineering and...DISTRIBUTION UNLIMITED. AFIT-ENP-14-M-09 CHARACTERIZATION AND MITIGATION OF RESISTIVE LOSSES IN A LARGE AREA LASER POWER CONVERTER Eli A. Garduño, BS

  15. Power loss in open cavity diodes and a modified Child-Langmuir law

    SciTech Connect

    Biswas, Debabrata; Kumar, Raghwendra; Puri, R.R.

    2005-09-15

    Diodes used in most high power devices are inherently open. It is shown that under such circumstances, there is a loss of electromagnetic radiation leading to a lower critical current as compared to closed diodes. The power loss can be incorporated in the standard Child-Langmuir framework by introducing an effective potential. The modified Child-Langmuir law can be used to predict the maximum power loss for a given plate separation and potential difference as well as the maximum transmitted current for this power loss. The effectiveness of the theory is tested numerically.

  16. Lower Hybrid wave edge power loss quantification on the Alcator C-Mod tokamak

    NASA Astrophysics Data System (ADS)

    Faust, I. C.

    2015-11-01

    For the first time, the power deposition of Lower Hybrid RF waves into the edge plasma of a diverted tokamak has been systematically quantified. Edge deposition represents a parasitic loss of power that can greatly impact the use and efficiency of Lower Hybrid Current Drive (LHCD) at reactor-relevant densities. Through the use of a unique set of fast time resolution edge diagnostics, including innovative fast-thermocouples, an extensive set of Langmuir probes, and a Lyα ionization camera, the toroidal, poloidal and radial structure of the power deposition has been simultaneously determined. Power modulation was used to directly isolate the RF effects due to the prompt (t <τE) response of the scrape-off-layer (SOL) plasma to LHRF power. LHRF power was found to absorb more strongly in the edge at higher densities. It is found that a majority of this edge-deposited power is promptly conducted to the divertor. This correlates with the loss of current drive efficiency at high density previously observed on Alcator C-Mod, and displaying characteristics that contrast with the local RF edge absorption seen on other tokamaks. Measurements of ionization in the active divertor show dramatic changes due to LHRF power, implying that divertor region can be key for the LHRF edge power deposition physics. These observations support the existence a loss mechanism near the edge for LHRF at high density (ne > 1 . 0 .1020 [m-3]). Results will be shown addressing the distribution of power within the SOL, including the toroidal symmetry and radial distribution. These characteristics are important for deducing the cause of the reduced LHCD efficiency at high density and motivates the tailoring of wave propagation to minimize SOL interaction, for example, through the use of high-field-side launch. This work was performed on the Alcator C-Mod tokamak, a DoE Office of Science user facility, and is supported by USDoE award DE-FC02-99ER54512.

  17. Novel binary PSO algorithm based optimization of transmission expansion planning considering power losses

    NASA Astrophysics Data System (ADS)

    Astuty; Haryono, T.

    2016-04-01

    Transmission expansion planning (TEP) is one of the issue that have to be faced caused by addition of large scale power generation into the existing power system. Optimization need to be conducted to get optimal solution technically and economically. Several mathematic methods have been applied to provide optimal allocation of new transmission line such us genetic algorithm, particle swarm optimization and tabu search. This paper proposed novel binary particle swarm optimization (NBPSO) to determine which transmission line should be added to the existing power system. There are two scenerios in this simulation. First, considering transmission power losses and the second is regardless transmission power losses. NBPSO method successfully obtain optimal solution in short computation time. Compare to the first scenario, the number of new line in second scenario which regardless power losses is less but produces high power losses that cause the cost becoming extremely expensive.

  18. Effect of geometry and operating conditions on spur gear system power loss

    NASA Technical Reports Server (NTRS)

    Anderson, N. E.; Loewenthal, S. H.

    1980-01-01

    The results of an analysis of the effects of spur gear size, pitch, width, and ratio on total mesh power loss for a wide range of speeds, torques, and oil viscosities are presented. The analysis uses simple algebraic expressions to determine gear sliding, rolling, and windage losses and also incorporates an approximate ball bearing power loss expression. The analysis shows good agreement with published data. Large diameter and fine pitched gears had higher peak efficiencies but low part load efficiency. Gear efficiencies were generally greater than 98 percent except at very low torque levels. Tare (no-load) losses are generally a significant percentage of the full load loss except at low speeds.

  19. Loss of Load Probability Calculation for West Java Power System with Nuclear Power Plant Scenario

    NASA Astrophysics Data System (ADS)

    Azizah, I. D.; Abdullah, A. G.; Purnama, W.; Nandiyanto, A. B. D.; Shafii, M. A.

    2017-03-01

    Loss of Load Probability (LOLP) index showing the quality and performance of an electrical system. LOLP value is affected by load growth, the load duration curve, forced outage rate of the plant, number and capacity of generating units. This reliability index calculation begins with load forecasting to 2018 using multiple regression method. Scenario 1 with compositions of conventional plants produce the largest LOLP in 2017 amounted to 71.609 days / year. While the best reliability index generated in scenario 2 with the NPP amounted to 6.941 days / year in 2015. Improved reliability of systems using nuclear power more efficiently when compared to conventional plants because it also has advantages such as emission-free, inexpensive fuel costs, as well as high level of plant availability.

  20. Continued Investigation of Leakage and Power Loss Test Results for Competing Turbine Engine Seals

    NASA Technical Reports Server (NTRS)

    Delgado, Irebert R.; Proctor, Margaret P.

    2006-01-01

    Secondary seal leakage in jet engine applications results in power losses to the engine cycle. Likewise, seal power loss in jet engines not only result in efficiency loss but also increase the heat input into the engine resulting in reduced component lives. Experimental work on labyrinth and annular seals was performed at NASA Glenn Research Center to quantify seal leakage and power loss at various temperatures, seal pressure differentials, and surface speeds. Data from annular and labyrinth seals are compared with previous brush and finger seal test results. Data are also compared to literature. Annular and labyrinth seal leakage rates are 2 to 3 times greater than brush and finger seal rates. Seal leakage decreases with increasing speed but increases with increasing test temperature due to thermal expansion mismatch. Also seal power loss increases with surface speed, seal pressure differential, mass flow rate, and radial clearance. Annular and labyrinth seal power losses were higher than those of brush or finger seal data. The brush seal power loss was 15 to 30 percent lower than annular and labyrinth seal power loss.

  1. Minimizing Losses in a Space Laser Power Beaming System

    DTIC Science & Technology

    2010-03-01

    focused sunlight onto enemy ships to set them ablaze (Perram, 2009). In more recent history the inventor Nikola Tesla proposed a wireless power...in which to power modern conveniences than running wires through walls or along ceilings and floors. This Tesla Effect can be easily demonstrated...using a Tesla Coil to ionize air particles and create a current in a modern fluorescent tube. Once the device has been turned on simply holding the

  2. Analysis of Apex Seal Friction Power Loss in Rotary Engines

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F.; Owen, A. Karl

    2010-01-01

    An analysis of the frictional losses from the apex seals in a rotary engine was developed. The modeling was initiated with a kinematic analysis of the rotary engine. Next a modern internal combustion engine analysis code was altered for use in a rotary engine to allow the calculation of the internal combustion pressure as a function of rotor rotation. Finally the forces from the spring, inertial, and combustion pressure on the seal were combined to provide the frictional horsepower assessment.

  3. 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.

  4. Optimization of magnetic neurostimulation waveforms for minimum power loss.

    PubMed

    Goetz, S M; Truong, N C; Gerhofer, M G; Peterchev, A V; Herzog, H-G; Weyh, T

    2012-01-01

    Magnetic stimulation is a key tool in experimental brain research and several clinical applications. Whereas coil designs and the spatial field properties have been intensively studied in the literature, the temporal dynamics of the field has received little attention. The available pulse shapes are typically determined by the relatively limited capabilities of commercial stimulation devices instead of efficiency or optimality. Furthermore, magnetic stimulation is relatively inefficient with respect to the required energy compared to other neurostimulation techniques. We therefore analyze and optimize the waveform dynamics with a nonlinear model of a mammalian motor axon for the first time, without any pre-definition of waveform candidates. We implemented an unbiased and stable numerical algorithm using variational calculus in combination with a global optimization method. This approach yields very stable results with comprehensible characteristic properties, such as a first phase which reduces ohmic losses in the subsequent pulse phase. We compare the energy loss of these optimal waveforms with the waveforms generated by existing magnetic stimulation devices.

  5. Does caval aplanarity influence power losses across in vitro cavopulmonary connections?

    PubMed

    Gerdes, A; Hanke, T; Ahrens, V; Pfister, G; Sievers, H-H

    2002-01-01

    Optimally designed cavopulmonary connections are desirable to reduce transanastomotic power loss. Since aplanarity of the total cavopulmonary connections results from the natural anterior-posterior position of the superior vena cava and the right pulmonary artery, the aim of this study was to investigate the influence of aplanarity of caval offset on transanastomotic power losses. Two types of cavopulmonary connections, a planar cross-like connection and a nonplanar V-shaped anastomosis, were studied in a mock circulation, comparing for each type native porcine vessels and Perspex glass models. Total flow varied between 1200 and 6000 ml/min at superior to inferior caval flow ratios of SVC/IVC = 50/50% and 33/67%, respectively. Pressures and flows were measured and power losses calculated. No significant differences in power losses were found between the planar and aplanar connections for native vessels or for Perspex glass models. Power losses across the native preparations in each configuration were significantly higher than those in the corresponding Perspex glass model. The simulation of the natural aplanar V-shaped caval offset in total cavopulmonary connections used to bypass the right ventricle seems to have no relevant additional effect on in vitro power losses compared to planar connections.

  6. 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.

  7. 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.

  8. 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.

  9. 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…

  10. Activity loss and depression in age-related macular degeneration.

    PubMed

    Rovner, Barry W; Casten, Robin J

    2002-01-01

    Age-related macular degeneration (AMD) is the most frequent cause of severe vision loss in older persons and is associated with high rates of disability and depression. The authors evaluated 51 patients with bilateral AMD to investigate the interrelationships of disease severity, disability, and depression and focused on loss of valued activities as an emblematic disabling consequence of AMD. They characterized depression by the Center for Epidemiologic Studies-Depression (CES-D) score, a syndromal state based on the CES-D, and as a level of distress (Index of Affective Suffering; IAS). Thirty subjects (58.8%) had loss of a valued, discretionary activity. They had worse visual acuity and more depressive symptoms and were represented in higher IAS levels than other subjects. Visual acuity was significantly correlated with IAS levels, but not with CES-D scores or syndromal depression. A regression model demonstrated that activity loss mediated the relationship between visual acuity and IAS level. Affective distress occurs in AMD, largely to the extent that valued activities are relinquished because of vision loss. IAS levels best illuminated this relationship, suggesting the value of this dimension of affective functioning in studies of the consequences of chronic disease.

  11. Effect of geometry and operating conditions on spur gear system power loss

    NASA Technical Reports Server (NTRS)

    Anderson, N. E.; Loewenthal, S. H.

    1980-01-01

    The results of an analysis of the effects of spur gear size, pitch, width and ratio on total mesh power loss for a wide range of speeds, torques and oil viscosities are presented. The analysis uses simple algebraic expressions to determine gear sliding, rolling and windage losses and also incorporates an approximate ball bearing power loss expression. The analysis shows good agreement with published data. Large diameter and fine-pitched gears had higher peak efficiencies but lower part-load efficiency. Gear efficiencies were generally greater than 98 percent except at very low torque levels. Tare (no-load) losses are generally a significant percentage of the full-load loss except at low speeds.

  12. Nonlinear electromagnetic effects on magnetic bearing performance and power loss

    NASA Astrophysics Data System (ADS)

    Kenny, Andrew

    Magnetic bearings are now being used in many applications. One of their features is their ability to apply force without contact. Thus they do not wear out from friction and are quiet. Magnetic bearings have very low levels of parasitic drag torque and force, especially at lower speeds. Active magnetic bearings can utilize microprocessors and feedback to control or excite vibrations in a manner that is unique from all other types of bearings. This dissertation presents methods to design magnetic bearings and makes some advances to them. The circuit model equations for a homopolar bearing are presented and a solution is found including the effects of magnetic flux saturation and laminate stacking. Circuit model equations for thrust bearings are presented. Linearized frequency dependent reluctance elements are incorporated into these equations. The equations are arranged to predict the frequency dependence of thrust bearings and the predictions agree with measurements. Finite element models are used extensively to back up the circuit model results. The drag torque caused by high rotation speed is calculated by the finite element method. The accuracy of these calculations is confirmed by comparison to measurements available in previously published experiments. Predictions of the drag torque in homopolar bearing rotor spacers are presented. The finite element method is also used to confirm the performance equations derived for a novel thrust bearing and a novel radial bearing, and it is also used to confirm the advanced circuit equations which are demonstrated on homopolar bearings.

  13. Computer model for electrochemical cell performance loss over time in terms of capacity, power, and conductance (CPC)

    SciTech Connect

    Gering, Kevin L.

    2015-09-01

    Available capacity, power, and cell conductance figure centrally into performance characterization of electrochemical cells (such as Li-ion cells) over their service life. For example, capacity loss in Li-ion cells is due to a combination of mechanisms, including loss of free available lithium, loss of active host sites, shifts in the potential-capacity curve, etc. Further distinctions can be made regarding irreversible and reversible capacity loss mechanisms. There are tandem needs for accurate interpretation of capacity at characterization conditions (cycling rate, temperature, etc.) and for robust self-consistent modeling techniques that can be used for diagnostic analysis of cell data as well as forecasting of future performance. Analogous issues exist for aging effects on cell conductance and available power. To address these needs, a modeling capability was developed that provides a systematic analysis of the contributing factors to battery performance loss over aging and to act as a regression/prediction platform for cell performance. The modeling basis is a summation of self-consistent chemical kinetics rate expressions, which as individual expressions each covers a distinct mechanism (e.g., loss of active host sites, lithium loss), but collectively account for the net loss of premier metrics (e.g., capacity) over time for a particular characterization condition. Specifically, sigmoid-based rate expressions are utilized to describe each contribution to performance loss. Through additional mathematical development another tier of expressions is derived and used to perform differential analyses and segregate irreversible versus reversible contributions, as well as to determine concentration profiles over cell aging for affected Li+ ion inventory and fraction of active sites that remain at each time step. Reversible fade components are surmised by comparing fade rates at fast versus slow cycling conditions. The model is easily utilized for predictive

  14. Power Loss Analysis and Comparison of Segmented and Unsegmented Energy Coupling Coils for Wireless Energy Transfer

    PubMed Central

    Tang, Sai Chun; McDannold, Nathan J.

    2015-01-01

    This paper investigated the power losses of unsegmented and segmented energy coupling coils for wireless energy transfer. Four 30-cm energy coupling coils with different winding separations, conductor cross-sectional areas, and number of turns were developed. The four coils were tested in both unsegmented and segmented configurations. The winding conduction and intrawinding dielectric losses of the coils were evaluated individually based on a well-established lumped circuit model. We found that the intrawinding dielectric loss can be as much as seven times higher than the winding conduction loss at 6.78 MHz when the unsegmented coil is tightly wound. The dielectric loss of an unsegmented coil can be reduced by increasing the winding separation or reducing the number of turns, but the power transfer capability is reduced because of the reduced magnetomotive force. Coil segmentation using resonant capacitors has recently been proposed to significantly reduce the operating voltage of a coil to a safe level in wireless energy transfer for medical implants. Here, we found that it can naturally eliminate the dielectric loss. The coil segmentation method and the power loss analysis used in this paper could be applied to the transmitting, receiving, and resonant coils in two- and four-coil energy transfer systems. PMID:26640745

  15. Power Loss Analysis and Comparison of Segmented and Unsegmented Energy Coupling Coils for Wireless Energy Transfer.

    PubMed

    Tang, Sai Chun; McDannold, Nathan J

    2015-03-01

    This paper investigated the power losses of unsegmented and segmented energy coupling coils for wireless energy transfer. Four 30-cm energy coupling coils with different winding separations, conductor cross-sectional areas, and number of turns were developed. The four coils were tested in both unsegmented and segmented configurations. The winding conduction and intrawinding dielectric losses of the coils were evaluated individually based on a well-established lumped circuit model. We found that the intrawinding dielectric loss can be as much as seven times higher than the winding conduction loss at 6.78 MHz when the unsegmented coil is tightly wound. The dielectric loss of an unsegmented coil can be reduced by increasing the winding separation or reducing the number of turns, but the power transfer capability is reduced because of the reduced magnetomotive force. Coil segmentation using resonant capacitors has recently been proposed to significantly reduce the operating voltage of a coil to a safe level in wireless energy transfer for medical implants. Here, we found that it can naturally eliminate the dielectric loss. The coil segmentation method and the power loss analysis used in this paper could be applied to the transmitting, receiving, and resonant coils in two- and four-coil energy transfer systems.

  16. Active control of transmission loss with smart foams.

    PubMed

    Kundu, Abhishek; Berry, Alain

    2011-02-01

    Smart foams combine the complimentary advantages of passive foam material and spatially distributed piezoelectric actuator embedded in it for active noise control applications. In this paper, the problem of improving the transmission loss of smart foams using active control strategies has been investigated both numerically and experimentally inside a waveguide under the condition of plane wave propagation. The finite element simulation of a coupled noise control system has been undertaken with three different smart foam designs and their effectiveness in cancelling the transmitted wave downstream of the smart foam have been studied. The simulation results provide insight into the physical phenomenon of active noise cancellation and explain the impact of the smart foam designs on the optimal active control results. Experimental studies aimed at implementing the real-time control for transmission loss optimization have been performed using the classical single input/single output filtered-reference least mean squares algorithm. The active control results with broadband and single frequency primary source inputs demonstrate a good improvement in the transmission loss of the smart foams. The study gives a comparative description of the transmission and absorption control problems in light of the modification of the vibration response of the piezoelectric actuator under active control.

  17. Leakage and Power Loss Test Results for Competing Turbine Engine Seals

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Delgado, Irebert R.

    2004-01-01

    Advanced brush and finger seal technologies offer reduced leakage rates over conventional labyrinth seals used in gas turbine engines. To address engine manufacturers concerns about the heat generation and power loss from these contacting seals, brush, finger, and labyrinth seals were tested in the NASA High Speed, High Temperature Turbine Seal Test Rig. Leakage and power loss test results are compared for these competing seals for operating conditions up to 922 K (1200 F) inlet air temperature, 517 KPa (75 psid) across the seal, and surface velocities up to 366 m/s (1200 ft/s).

  18. Eddy current power loss in structural steel due to cables carrying current in a perpendicular direction

    SciTech Connect

    Namjoshi, K.V.; Lavers, J.D.; Biringer, P.P. . Dept. of Electrical and Computer Engineering)

    1994-01-01

    This paper deals with eddy current power loss in structural steel, in the vicinity of cables carrying current in a perpendicular direction. The configuration is approximated by a long cylinder perpendicular to a filament current. An analytical method is used. Expressions are provided which describe the frequency dependence of the power loss. The influence of the permeability and the physical dimensions is considered. Formulae are given for the impedance of the cylinder in different frequency regions. Numerical results are presented to show the behavior.

  19. Emergency preparedness for power outages and wi-fi loss: tips for students and educators of online courses.

    PubMed

    Heithaus, Teresa

    2015-01-01

    Severe weather can impact online education due to a loss of power and Internet access that can last hours or weeks. Planning for such losses is essential to enable participation in the online classroom. This article discusses measures that can be used to maintain an online presence in the event of a power outage or loss of Wi-Fi.

  20. Using Reanalysis Data for the Prediction of Seasonal Wind Turbine Power Losses Due to Icing

    NASA Astrophysics Data System (ADS)

    Burtch, D.; Mullendore, G. L.; Delene, D. J.; Storm, B.

    2013-12-01

    The Northern Plains region of the United States is home to a significant amount of potential wind energy. However, in winter months capturing this potential power is severely impacted by the meteorological conditions, in the form of icing. Predicting the expected loss in power production due to icing is a valuable parameter that can be used in wind turbine operations, determination of wind turbine site locations and long-term energy estimates which are used for financing purposes. Currently, losses due to icing must be estimated when developing predictions for turbine feasibility and financing studies, while icing maps, a tool commonly used in Europe, are lacking in the United States. This study uses the Modern-Era Retrospective Analysis for Research and Applications (MERRA) dataset in conjunction with turbine production data to investigate various methods of predicting seasonal losses (October-March) due to icing at two wind turbine sites located 121 km apart in North Dakota. The prediction of icing losses is based on temperature and relative humidity thresholds and is accomplished using three methods. For each of the three methods, the required atmospheric variables are determined in one of two ways: using industry-specific software to correlate anemometer data in conjunction with the MERRA dataset and using only the MERRA dataset for all variables. For each season, a percentage of the total expected generated power lost due to icing is determined and compared to observed losses from the production data. An optimization is performed in order to determine the relative humidity threshold that minimizes the difference between the predicted and observed values. Eight seasons of data are used to determine an optimal relative humidity threshold, and a further three seasons of data are used to test this threshold. Preliminary results have shown that the optimized relative humidity threshold for the northern turbine is higher than the southern turbine for all methods

  1. 26 CFR 1.469-2 - Passive activity loss.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... meaning of § 1.469-2T) from the interests. (E) Coordination with § 1.469-2T(c)(2)(ii). If § 1.469-2T(c)(2... from a passive activity after the application of § 1.469-2T(c)(2)(ii). (F) Coordination with section...); (vi) Gross income attributable to the reimbursement of a loss from fire, storm, shipwreck, or...

  2. 26 CFR 1.469-2 - Passive activity loss.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... meaning of § 1.469-2T) from the interests. (E) Coordination with § 1.469-2T(c)(2)(ii). If § 1.469-2T(c)(2... from a passive activity after the application of § 1.469-2T(c)(2)(ii). (F) Coordination with section...); (vi) Gross income attributable to the reimbursement of a loss from fire, storm, shipwreck, or...

  3. Charged fusion product loss measurements using nuclear activation

    SciTech Connect

    Bonheure, G.; Hult, M.; Gonzalez de Orduna, R.; Wieslander, E.; Arnold, D.; Dombrowski, H.; Laubenstein, M.; Murari, A.; Collaboration: JET-EFDA Contributors

    2010-10-15

    In ITER, {alpha} particle loss measurements will be required in order to understand the alpha particle physics. Techniques capable of operating in a fusion reactor environment need further development. Recent experimental studies on JET demonstrated the potential of nuclear activation to measure the flux of escaping MeV ions. New results from MeV ion induced activation of metallic, ceramic, and crystal samples placed near the plasma edge are reported. Activation products were measured as function of orientation with respect to the magnetic field as well as function of the distance to the plasma. Sample activity was measured using ultralow-level gamma-ray spectrometry. Distribution of 14.68 MeV fusion proton induced activation products is strongly anisotropic in agreement with simulations and falls off sharply with increasing distance to the plasma. Prospects for using the technique in ITER are discussed.

  4. Loss of Consciousness Is Associated with Stabilization of Cortical Activity

    PubMed Central

    Solovey, Guillermo; Alonso, Leandro M.; Yanagawa, Toru; Fujii, Naotaka; Magnasco, Marcelo O.; Cecchi, Guillermo A.

    2015-01-01

    What aspects of neuronal activity distinguish the conscious from the unconscious brain? This has been a subject of intense interest and debate since the early days of neurophysiology. However, as any practicing anesthesiologist can attest, it is currently not possible to reliably distinguish a conscious state from an unconscious one on the basis of brain activity. Here we approach this problem from the perspective of dynamical systems theory. We argue that the brain, as a dynamical system, is self-regulated at the boundary between stable and unstable regimes, allowing it in particular to maintain high susceptibility to stimuli. To test this hypothesis, we performed stability analysis of high-density electrocorticography recordings covering an entire cerebral hemisphere in monkeys during reversible loss of consciousness. We show that, during loss of consciousness, the number of eigenmodes at the edge of instability decreases smoothly, independently of the type of anesthetic and specific features of brain activity. The eigenmodes drift back toward the unstable line during recovery of consciousness. Furthermore, we show that stability is an emergent phenomenon dependent on the correlations among activity in different cortical regions rather than signals taken in isolation. These findings support the conclusion that dynamics at the edge of instability are essential for maintaining consciousness and provide a novel and principled measure that distinguishes between the conscious and the unconscious brain. SIGNIFICANCE STATEMENT What distinguishes brain activity during consciousness from that observed during unconsciousness? Answering this question has proven difficult because neither consciousness nor lack thereof have universal signatures in terms of most specific features of brain activity. For instance, different anesthetics induce different patterns of brain activity. We demonstrate that loss of consciousness is universally and reliably associated with stabilization

  5. 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.

  6. Emissivity-corrected power loss calibration for lock-in thermography measurements on silicon solar cells

    SciTech Connect

    Kasemann, Martin; Walter, Benjamin; Meinhardt, Christoph; Ebser, Jan; Kwapil, Wolfram; Warta, Wilhelm

    2008-06-01

    This paper describes power loss calibration procedures with implemented emissivity correction. The determination of our emissivity correction matrix does neither rely on blackbody reference measurements nor on the knowledge of any sample temperatures. To describe the emissivity-corrected power calibration procedures in detail, we review the theory behind lock-in thermography and show experimentally that the lock-in signal is proportional to the power dissipation in the solar cell. Experiments show the successful application of our emissivity correction procedure, which significantly improves the informative value of lock-in thermography images and the reliability of the conclusions drawn from these images.

  7. About Losses in Pumping Generators of High-Power Electrodischarge Excimer Lasers

    NASA Astrophysics Data System (ADS)

    Ivanov, N. G.; Losev, V. F.

    2015-04-01

    Energy losses in pumping systems of discharge high-power lasers are investigated. To estimate the losses, the discharge circuit operation was modeled, and its calculation was performed using the program PSpice. Results of measurements and calculations demonstrate that the resistance of a rail gap with electric field distortion exceeds several times the resistance of a single-channel gap without field distortion. A difference in the resistances is explained by different mechanisms of discharge burning: in the first case diffusion mechanism and in the second case the spark mechanism. The low efficiency of the high-power excimer lasers (~1%) is explained by high energy losses in the rail gap that reach more than 50% of the initially stored energy.

  8. Analysis on heat loss characteristics of a 10 kV HTS power substation

    NASA Astrophysics Data System (ADS)

    Teng, Yuping; Dai, Shaotao; Song, Naihao; Zhang, Jingye; Gao, Zhiyuan; Zhu, Zhiqin; Zhou, Weiwei; Wei, Zhourong; Lin, Liangzhen; Xiao, Liye

    2014-09-01

    A 10 kV High Temperature Superconducting power substation (10 kV HTS substation), supported by Chinese State 863 projects, was developed and has been running to supply power for several factories for more than two years at an industrial park of Baiyin, Gansu province in Northwest China. The system of the 10 kV HTS substation compositions, including a HTS cable, a HTS transformer, a SFCL, and a SMES, are introduced. The SMES works at liquid helium temperature and the other three apparatus operates under liquid nitrogen condition. There are mainly four types of heat losses existing in each HTS apparatus of the 10 kV HTS substation, including AC loss, Joule heat loss, conductive heat, and leak-in heat from cryostat. A small quantity of AC loss still exists due to the harmonic component of the current when it carries DC for HTS apparatus. The principle and basis for analysis of the heat losses are introduced and the total heat loss of each apparatus are calculated or estimated, which agree well with the test result. The analysis and result presented are of importance for the design of the refrigeration system.

  9. An estimation method of the fault wind turbine power generation loss based on correlation analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Zhu, Shourang; Wang, Wei

    2017-01-01

    A method for estimating the power generation loss of a fault wind turbine is proposed in this paper. In this method, the wind speed is estimated and the estimated value of the loss of power generation is given by combining the actual output power characteristic curve of the wind turbine. In the wind speed estimation, the correlation analysis is used, and the normal operation of the wind speed of the fault wind turbine is selected, and the regression analysis method is used to obtain the estimated value of the wind speed. Based on the estimation method, this paper presents an implementation of the method in the monitoring system of the wind turbine, and verifies the effectiveness of the proposed method.

  10. Synthesis of a low loss Mn-Zn ferrite for power applications

    NASA Astrophysics Data System (ADS)

    Tsakaloudi, Vasiliki; Zaspalis, Vassilios

    2016-02-01

    Current market trends of the switching power supplies industry require even lower energy losses in power conversion systems with maintenance of satisfactory initial permeability levels. Typical operation conditions refer to a frequency of 100 kHz, an induction level of 200 mT and a steady state temperature of 100° C. In this work the development of a polycrystalline Mn-Zn ferrite material that exhibits initial relative magnetic permeability above 2500 and very low power losses at 100 kHz, 200 mmT and 100° C is presented. The Mn-Zn ferrite samples were prepared by the conventional solid state reaction method. Sintering was performed under controlled atmosphere conditions. The combinatorial role of TiO2 and CoO together with Zn content, as well as the effects of the process parameters on the magnetic performance of the Mn-Zn ferrite was evaluated. It is shown that the development of the adequate polycrystalline microstructure that is characterized by (a) high sintered density, (b) homogenous grain size that is free of morphological or chemical pinning defects and (c) high resistivity grain boundary structure, can be achieved by means of appropriate compositional and dopant adjustment, anisotropy control and specific resistivity optimization. The newly developed Mn-Zn ferrite is characterized by high sintered density of 4.91 g/cm3, initial magnetic permeability of 2512 (at 10 kHz, 0.1 mT, 25 °C), high saturation magnetic flux density of 560 mT (at 10 kHz, 1200 A/m, 25 °C) and very low power losses (Pv) of 224 mW/cm3 (at 100 kHz, 200 mT, 100 °C) combined with very low power losses of 470 mW/cm3 even at room temperature, establishing it as ideal for power applications.

  11. Sleep loss activates cellular markers of inflammation: sex differences.

    PubMed

    Irwin, Michael R; Carrillo, Carmen; Olmstead, Richard

    2010-01-01

    Sleep disturbance is associated with inflammation and related disorders including cardiovascular disease, arthritis, and diabetes mellitus. Given sex differences in the prevalence of inflammatory disorders with stronger associations in females, this study was undertaken to test the effects of sleep loss on cellular mechanisms that contribute to proinflammatory cytokine activity. In 26 healthy adults (11 females; 15 males), monocyte intracellular proinflammatory cytokine production was repeatedly assessed at 08:00, 12:00, 16:00, 20:00, and 23:00h during a baseline period and after partial sleep deprivation (awake from 23:00 to 3.00h). In the morning after a night of sleep loss, monocyte production of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) differentially changed between the two sexes. Whereas both females and males showed a marked increase in the lipopolysaccharide (LPS) - stimulated production of IL-6 and TNF-alpha in the morning immediately after PSD, production of these cytokines during the early- and late evening was increased in the females as compared to decreases in the males. Sleep loss induces a functional alteration of monocyte proinflammatory cytokine responses with females showing greater cellular immune activation as compared to changes in males. These results have implications for understanding the role of sleep disturbance in the differential risk profile for inflammatory disorders between the sexes.

  12. Sleep Loss Activates Cellular Markers of Inflammation: Sex Differences

    PubMed Central

    Irwin, Michael R.; Carrillo, Carmen; Olmstead, Richard

    2009-01-01

    Sleep disturbance is associated with inflammation and related disorders including cardiovascular disease, arthritis, and diabetes mellitus. Given sex differences in the prevalence of inflammatory disorders with stronger associations in females, this study was undertaken to test the effects of sleep loss on cellular mechanisms that contribute to proinflammatory cytokine activity. In 26 healthy adults (11 females; 15 males), monocyte intracellular proinflammatory cytokine production was repeatedly assessed at 08:00, 12:00, 16:00, 20:00, and 23:00 h during a baseline period and after partial sleep deprivation (awake from 11 PM to 3 AM). In the morning after a night of sleep loss, monocyte production of interleukin 6 and tumor necrosis factor- α differentially changed between the two sexes. Whereas both females and males showed a marked increase in the lipopolysaccharide (LPS) - stimulated production of IL-6 and TNF-α in the morning immediately after PSD, production of these cytokines during the early- and late evening was increased in the females as compared to decreases in the males. Sleep loss induces a functional alteration of monocyte proinflammatory cytokine responses with females showing greater cellular immune activation as compared to changes in males. These results have implications for understanding the role of sleep disturbance in the differential risk profile for inflammatory disorders between the sexes. PMID:19520155

  13. Power loss characteristics of a sensing element based on a polymer optical fiber under cyclic tensile elongation.

    PubMed

    Chen, Yung-Chuan; Chen, Li-Wen; Lu, Wei-Hua

    2011-01-01

    In this study, power losses in polymer optical fiber (POF) subjected to cyclic tensile loadings are studied experimentally. The parameters discussed are the cyclic load level and the number of cycles. The results indicate that the power loss in POF specimens increases with increasing load level or number of cycles. The power loss can reach as high as 18.3% after 100 cyclic loadings. Based on the experimental results, a linear equation is proposed to estimate the relationship between the power loss and the number of cycles. The difference between the estimated results and the experimental results is found to be less than 3%.

  14. Signal losses with real-time three-dimensional power Doppler imaging.

    PubMed

    Garcia, Damien; Fenech, Marianne; Qin, Zhao; Soulez, Gilles; Cloutier, Guy

    2007-10-01

    Power Doppler imaging (PDI) has been shown to be influenced by the wall filter when assessing arterial stenoses. Real-time 3-D Doppler imaging may likely become a widespread practice in the near future, but how the wall filter could affect PDI during the cardiac cycle has not been investigated. The objective of the study was to demonstrate that the wall filter may produce unexpected major signal losses in real-time 3-D PDI. To test our hypothesis, we first validated binary images obtained from analytical simulations with in vitro PDI acquisitions performed in a tube under pulsatile flow conditions. We then simulated PDI images in the presence of a severe stenosis, considering physiological conditions by finite element modeling. Power Doppler imaging simulations revealed important signal losses within the lumen area at different instants of the flow cycle, and there was a very good concordance between measured and predicted PDI binary images in the tube. Our results show that the wall filter may induce severe PDI signal losses that could negatively influence the assessment of vascular stenosis. Clinicians should therefore be aware of this cause of signal loss to properly interpret power Doppler angiographic images.

  15. Determining Yankee Nuclear Power Station neutron activation

    SciTech Connect

    Heider, K.J.; Morrissey, K.J. )

    1993-01-01

    The Yankee nuclear power station located in Rowe, Massachusetts, permanently ceased power operations on February 26, 1992, after 31 yr of operation. Yankee has since initiated decommissioning planning activities. A significant component of these activities is a determination of the extent of radiological contamination of the Yankee site. Included in this effort was determination of the extent of neutron activation of plant components. This paper describes the determination of the neutron activation of the Yankee reactor vessel, associated internals, and surrounding structures. The Yankee reactor vessel is a 600-MW(thermal) stainless steel-lined, carbon steel vessel with stainless steel internal components designed by Westinghouse. The reactor vessel is surrounded and supported by a carbon steel neutron shield tank that was filled with chromated water during plant operation. A 5-ft-thick concrete biological shield wall surrounds the neutron shield tank. A project is under way to remove the reactor vessel internals from the reactor vessel.

  16. Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX

    SciTech Connect

    Perkins, R. J.; Ahn, Joonwook; Bell, R. E.; Bertelli, Nicola; Diallo, A.; Gerhardt, S.; Gray, T. K.; Green, David L; Jaeger, E. F.; Hosea, J.; Jaworski, M. A.; LeBlanc, B; Kramer, G.; McLean, Adam G; Maingi, Rajesh; Phillips, C. K.; Podesta, M.; Ryan, Philip Michael; Sabbagh, S. A.; Scotti, F.; Taylor, G.; Wilson, J. R.

    2013-01-01

    Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict

  17. Towards identifying the mechanisms underlying field-aligned edge-loss of HHFW power on NSTX

    SciTech Connect

    Perkins, R. J.; Bell, R. E.; Bertelli, N.; Diallo, A.; Gerhardt, S.; Hosea, J. C.; Jaworski, M. A.; LeBlanc, B. P.; Kramer, G. J.; Maingi, R.; Phillips, C. K.; Podestà, M.; Roquemore, L.; Scotti, F.; Taylor, G.; Wilson, J. R.; Ahn, J-W.; Gray, T. K.; Green, D. L.; McLean, A.; and others

    2014-02-12

    Fast-wave heating will be a major heating scheme on ITER, as it can heat ions directly and is relatively unaffected by the large machine size unlike neutral beams. However, fast-wave interactions with the plasma edge can lead to deleterious effects such as, in the case of the high-harmonic fast-wave (HHFW) system on NSTX, large losses of fast-wave power in the scrape off layer (SOL) under certain conditions. In such scenarios, a large fraction of the lost HHFW power is deposited on the upper and lower divertors in bright spiral shapes. The responsible mechanism(s) has not yet been identified but may include fast-wave propagation in the scrape off layer, parametric decay instability, and RF currents driven by the antenna reactive fields. Understanding and mitigating these losses is important not only for improving the heating and current-drive on NSTX-Upgrade but also for understanding fast-wave propagation across the SOL in any fast-wave system. This talk summarizes experimental results demonstrating that the flow of lost HHFW power to the divertor regions largely follows the open SOL magnetic field lines. This lost power flux is relatively large close to both the antenna and the last closed flux surface with a reduced level in between, so the loss mechanism cannot be localized to the antenna. At the same time, significant losses also occur along field lines connected to the inboard edge of the bottom antenna plate. The power lost within the spirals is roughly estimated, showing that these field-aligned losses to the divertor are significant but may not account for the total HHFW loss. To elucidate the role of the onset layer for perpendicular fast-wave propagation with regards to fast-wave propagation in the SOL, a cylindrical cold-plasma model is being developed. This model, in addition to advanced RF codes such as TORIC and AORSA, is aimed at identifying the underlying mechanism(s) behind these SOL losses, to minimize their effects in NSTX-U, and to predict

  18. Reflectance loss of prospective solar concentrator mirrors in erosive environments. The Crosbyton Solar Power Project

    SciTech Connect

    Bethea, R.M.; Barringer, M.T.; Chin, S.; Collier, E.G.; Cooper, A.M.; Reichert, J.D. Jr.; Williams, P.F.

    1986-01-01

    The problem addressed in this phase of the Crosbyton Solar Power Project was that of the effect of weathering of solar concentrator mirrors proposed for use in the fixed-mirror, distributed-focus (solar bowl) system with particular emphasis on erosion due to exposure during dust storms. The specific objectives of this research were to evaluate the mirrors with respect to initial reflectance, loss of reflectance due to dust storms and other outdoor exposure phenomena, and dimensional stability; and to develop a rapid technique for the simulation of dust storms so that a model for such reflectance loss as a function of exposure could be developed.

  19. Using reanalysis data for the prediction of seasonal wind turbine power losses due to icing

    NASA Astrophysics Data System (ADS)

    Burtch, Daniel G.

    The Northern Plains region of the United States is home to a significant amount of potential wind energy. However, in winter months capturing this potential power is severely impacted by the meteorological conditions, in the form of icing. Predicting the expected loss in power production due to icing is a valuable parameter that can be used in wind turbine operations, determination of wind turbine site locations and long-term energy estimates which are used for financing purposes. Currently, losses due to icing must be estimated when developing predictions for turbine feasibility and financing studies, while icing maps, a tool commonly used in Europe, are lacking in the United States. This study uses the Modern-Era Retrospective Analysis for Research and Applications (MERRA) dataset in conjunction with turbine production data and in-situ wind measurements to investigate six methods of predicting seasonal losses (October-March) due to icing at two sites located in Petersburg, ND and Valley City, ND. The prediction of icing losses is based on temperature and relative humidity thresholds and is accomplished using six methods. Three methods use a Measure-Correlate-Predict (MCP) and flow model (WAsP) analysis for the determination of wind speeds and MERRA for temperature and relative humidity, while three methods use MERRA for all three variables. For each season from 2002 to 2010, the predicted losses due to icing are determined for a range of relative humidity thresholds and compared with observed icing losses. An optimal relative humidity is then determined and tested on all seasons from 2002 to 2013. The prediction methods are then compared to a common practice used in the wind energy industry of assuming a constant percentage loss for icing over the same time period. The three methods using MERRA data alone show severe deficiencies in the accurate determination of wind speeds which leads to a large underprediction in accurate power output. Of the three MCP

  20. Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss

    PubMed Central

    Wang, Yanli; Steele, Charles R.; Puria, Sunil

    2016-01-01

    Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar membrane motion with one free parameter for the OHCs. The calculations predict that the total power output from the three rows of OHCs can be over three orders of magnitude greater than the acoustic input power at 10 dB sound pressure level (SPL). While previous work shows that the power gain, or the negative damping, diminishes with intensity, we show explicitly based on our model that OHC power output increases and saturates with SPL. The total OHC power output is about 2 pW at 80 dB SPL, with a maximum of about 10 fW per OHC. PMID:26792556

  1. Cochlear Outer-Hair-Cell Power Generation and Viscous Fluid Loss

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Steele, Charles R.; Puria, Sunil

    2016-01-01

    Since the discovery of otoacoustic emissions and outer hair cell (OHC) motility, the fundamental question of whether the cochlea produces mechanical power remains controversial. In the present work, direct calculations are performed on power loss due to fluid viscosity and power generated by the OHCs. A three-dimensional box model of the mouse cochlea is used with a feed-forward/feed-backward approximation representing the organ of Corti cytoarchitecture. The model is fit to in vivo basilar membrane motion with one free parameter for the OHCs. The calculations predict that the total power output from the three rows of OHCs can be over three orders of magnitude greater than the acoustic input power at 10 dB sound pressure level (SPL). While previous work shows that the power gain, or the negative damping, diminishes with intensity, we show explicitly based on our model that OHC power output increases and saturates with SPL. The total OHC power output is about 2 pW at 80 dB SPL, with a maximum of about 10 fW per OHC.

  2. Experimental study on guide friction contribution in global power loss of a tooth chain transmission

    NASA Astrophysics Data System (ADS)

    Velicu, R.; Papuc, R.; Gavrila, C. C.; Popa, S.

    2017-02-01

    The subject of the paper is the friction between a tooth chain and the guide. An experimental study is developed with the aim of determining the contribution of chain-guide friction on the global friction of a basic tooth chain transmission. The measurements have been made on a chain friction rig, testing a basic tooth chain transmission with transmission ratio equal to 1, with a controlled tensioning device. The following parameters can be adjusted and measured: rotational speed, tensioning force in the chain, position of the guide, temperature and pressure of the oil used for lubrication. Friction torque at the input shaft is a sum of friction torques coming from bearings, chain and guide. The paper presents the contribution of the guide in the power loss by friction, as percent of the power loss from friction in chain and guide together. Influences of speed, tensioning force and oil temperature are presented.

  3. Polarizing Field and Particle Concentration Dependence of the Magnetic Loss Power in Ferrofluids

    NASA Astrophysics Data System (ADS)

    Fannin, Paul C.; Malaescu, Iosif; Stefu, Nicoleta; Marin, Catalin N.

    2009-05-01

    The frequency (f) and polarizing field (H) dependence of the complex magnetic permeability μ(f,H) = μ'(f,H)-iμ″(f,H), of different magnetic fluid samples, over the range 100 MHz to 6 GHz and 0 to 102.4 kA/m, respectively, were analyzed. Starting from an initial magnetic fluid sample (sample A) with magnetite particles dispersed in kerosene and stabilized with oleic acid, having particle concentration n = 19.16ṡ1022 m-3, three samples were obtained by successive dilution with kerosene (with a dilution ratio 2:3) (samples A1, A2, and A3). Based on the complex magnetic permeability measurements of each sample, and for each field value, values of the specific magnetic loss power were obtained. We have also studied the dependence on particle concentration of the magnetic loss power, both in zero polarizing field and in the presence of the polarizing field.

  4. AC losses in superconductors with a power-law constitutive relation

    NASA Astrophysics Data System (ADS)

    Agassi, Y. D.

    2015-10-01

    The observed constitutive relation between the electrical field and current density in cuprates high temperature superconductors is a power-law of the current. This functional dependence is presumably related to the giant flux-creep domain. It is shown that this constitutive relation reflects the statistical spread of the pinning potential associated with creep motion of vortex bundles. The AC losses emanating from a power-law constitutive relation are calculated in an approach focused on the superconductor's electric field. For a slab geometry in the presence of a parallel AC magnetic field or transport current, the calculated AC-loss scaling laws are consistent with BSCCO data and the critical state model. Extensions of the approach are briefly discussed.

  5. Compact, low-loss and low-power 8×8 broadband silicon optical switch.

    PubMed

    Chen, Long; Chen, Young-kai

    2012-08-13

    We demonstrated a 8×8 broadband optical switch on silicon for transverse-electrical polarization using a switch-and-selector architecture. The switch has a footprint of only 8 mm × 8 mm, minimum on-chip loss of about 4 dB, and a port-to-port insertion loss variation of only 0.8 dB near some spectral regions. The port-to-port isolation is above 30 dB over the entire 80-nm-wide spectral range or above 45 dB near the central 30 nm. We also demonstrated a switching power of less than 1.5 mW per element and a speed of 2 kHz, and estimated the upper bound of total power consumption to be less than 70 mW even without optimization of the default state of the individual switch elements.

  6. Assessment of technologies for predicting insertion loss and directivity of power plant exhaust systems

    NASA Astrophysics Data System (ADS)

    Cummins, Jim R.; Loewenstein, Marshall

    2005-09-01

    Much technology exists for predicting the insertion loss, directivity and radiation of various components in a power plant. For example, the ASHRAE noise guide gives the IL and/or directivity for many duct configurations. Unfortunately, there are also many components or geometries for which there is currently no practical prediction methodology. The state of the technology for predicting insertion loss, directivity and sound radiation by power plant components, especially ducted sources, such as intake and exhaust, is reviewed with emphasis on modeling techniques and verification. Several cases where the normal prediction methods are both adequate and inadequate are presented. Suggestions are given as to methods and/or future development that could provide more accurate, reliable, or useable results.

  7. 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

  8. Solar power generation by use of Stirling engine and heat loss analysis of its cavity receiver

    NASA Astrophysics Data System (ADS)

    Hussain, Tassawar

    Since concentrated power generation by Stirling engine has the highest efficiency therefore efficient power generation by concentrated systems using a Stirling engine was a primary motive of this research. A 1 kW Stirling engine was used to generate solar power using a Fresnel lens as a concentrator. Before operating On-Sun test, engine's performance test was conducted by combustion test. Propane gas with air was used to provide input heat to the Stirling Engine and 350W power was generated with 14% efficiency of the engine. Two kinds of receivers were used for On-Sun test, first type was the Inconel tubes with trapped helium gas and the second one was the heat pipe. Heat pipe with sodium as a working fluid is considered the best approach to transfer the uniform heat from the receiver to the helium gas in the heater head of the engine. A Number of On-Sun experiments were performed to generate the power. A minimum 1kW input power was required to generate power from the Stirling engine but it was concluded that the available Fresnel lens was not enough to provide sufficient input to the Stirling engine and hence engine was lagged to generate the solar power. Later on, for a high energy input a Beam Down system was also used to concentrate the solar light on the heater head of the Stirling engine. Beam down solar system in Masdar City UAE, constructed in 2009 is a variation of central receiver plant with cassegrainian optics. Around 1.5kW heat input was achieved from the Beam Down System and it was predicted that the engine receiver at beam down has the significant heat losses of about 900W. These high heat losses were the major hurdles to get the operating temperature (973K) of the heat pipes; hence power could not be generated even during the Beam Down test. Experiments were also performed to find the most suitable Cavity Receiver configuration for maximum solar radiation utilizations by engine receiver. Dimensionless parameter aperture ration (AR=d/D) and aperture

  9. Refinements and practical implementation of a power based loss of grid detection algorithm for embedded generators

    NASA Astrophysics Data System (ADS)

    Barrett, James

    The incorporation of small, privately owned generation operating in parallel with, and supplying power to, the distribution network is becoming more widespread. This method of operation does however have problems associated with it. In particular, a loss of the connection to the main utility supply which leaves a portion of the utility load connected to the embedded generator will result in a power island. This situation presents possible dangers to utility personnel and the public, complications for smooth system operation and probable plant damage should the two systems be reconnected out-of-synchronism. Loss of Grid (or Islanding), as this situation is known, is the subject of this thesis. The work begins by detailing the requirements for operation of generation embedded in the utility supply with particular attention drawn to the requirements for a loss of grid protection scheme. The mathematical basis for a new loss of grid protection algorithm is developed and the inclusion of the algorithm in an integrated generator protection scheme described. A detailed description is given on the implementation of the new algorithm in a microprocessor based relay hardware to allow practical tests on small embedded generation facilities, including an in-house multiple generator test facility. The results obtained from the practical tests are compared with those obtained from simulation studies carried out in previous work and the differences are discussed. The performance of the algorithm is enhanced from the theoretical algorithm developed using the simulation results with simple filtering together with pattern recognition techniques. This provides stability during severe load fluctuations under parallel operation and system fault conditions and improved performance under normal operating conditions and for loss of grid detection. In addition to operating for a loss of grid connection, the algorithm will respond to load fluctuations which occur within a power island

  10. Parthanatos Mediates AIMP2 Activated Age Dependent Dopaminergic Neuronal Loss

    PubMed Central

    Lee, Yunjong; Karuppagounder, Senthilkumar S.; Shin, Joo-Ho; Lee, Yun-Il; Ko, Han Seok; Swing, Debbie; Jiang, Haisong; Kang, Sung-Ung; Lee, Byoung Dae; Kang, Ho Chul; Kim, Donghoon; Tessarollo, Lino; Dawson, Valina L.; Dawson, Ted M.

    2013-01-01

    The defining pathogenic feature of Parkinson’s disease is the age dependent loss of dopaminergic neurons. Mutations and inactivation of parkin, an ubiquitin E3 ligase, cause Parkinson’s disease through accumulation of pathogenic substrates. Here we show that transgenic overexpression of the parkin substrate, aminoacyl-tRNA synthetase complex interacting multifunctional protein-2 (AIMP2) leads to a selective, age-dependent progressive loss of dopaminergic neurons via activation of poly(ADP-ribose) polymerase-1 (PARP1). AIMP2 accumulation in vitro and in vivo results in PARP1 overactivation and dopaminergic cell toxicity via direct association of these proteins in the nucleus providing a new path to PARP1 activation other than DNA damage. Inhibition of PARP1 through gene deletion or drug inhibition reverses behavioral deficits and protects in vivo against dopamine neuron death in AIMP2 transgenic mice. These data indicate that brain permeable PARP inhibitors could be effective in delaying or preventing disease progression in Parkinson’s disease. PMID:23974709

  11. Fast wave heating and edge power losses in NSTX and NSTX-U

    NASA Astrophysics Data System (ADS)

    Bertelli, Nicola

    2013-10-01

    Experimental studies of high harmonic fast wave (HHFW) heating on the National Spherical Torus Experiment (NSTX) have demonstrated that substantial HHFW power loss can occur along the open field lines in the scrape-off layer (SOL), but the mechanism behind the loss is not yet understood. Extended ray tracing and full wave codes are being applied to specific NSTX discharges in order to predict the causes of this power loss. Previous full wave simulations predict that cavity-like modes may form outside of the LCFS. We find that inserting a collisional loss in the SOL of AORSA to represent a damping process indicates an effective collisional term of ν / ω ~ [ 0 . 05 - 0 . 1 ] which is considerably larger than the ν / ω ~ 0 . 005 obtained with Spitzer resistivity, suggesting the damping scale of the loss mechanism. The magnitude of the edge collisional losses are being used to evaluate possible potential damping mechanisms in the SOL. Initial numerical analyses show that the presence of the SOL has a significant impact on the launched antenna spectrum. The upgrade of NSTX, NSTX-U, will operate with toroidal magnetic fields (BT) up to 1 T, nearly twice the values used on NSTX. The doubling of BT while retaining the 30 MHz RF frequency moves the heating regime for NSTX-U to the mid harmonic fast wave (MHFW) regime, which will be analyzed and contrasted with the HHFW regime on NSTX. These studies indicate that direct ion damping might be more significant in NSTX-U under TRANSP predicted full performance conditions. Modifications of fast ion distributions due to the interaction of fast waves with NBI will be presented in both MHFW and HHFW regimes. Work supported by the SciDAC Center for Wave-Plasma Interactions under DE-FC02-01ER54648 and the US DOE under DE-AC02-CH0911466.

  12. 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.

  13. Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

    ERIC Educational Resources Information Center

    Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

    2011-01-01

    This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

  14. The central power source in active galaxies

    NASA Technical Reports Server (NTRS)

    Ptak, Roger; Stoner, Ronald

    1987-01-01

    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.

  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. Improved designs for p-i-n OLEDs towards the minimal power loss of devices

    NASA Astrophysics Data System (ADS)

    Qin, Dashan

    2014-05-01

    Currently, the low yield, high power loss, and poor stability of organic light emitting diodes (OLEDs) panels are remaining as the obstacles to the fast growth of the OLED industry, especially for the lighting application. The p-i-n OLEDs have been widely recognized as the promising method to circumvent these bottleneck factors, due to the unique merit of the electrical doping to enable low power loss. In p-i-n OLEDs, the frequently used n-doped electron transport layers (n-ETL1) such as n-BCP, n-Alq3 possess markedly lower conductivities but better capabilities of injecting electrons into ETL such as BCP, Alq3, as compared to another class of n-doped ETLs (n-ETL2), e.g., n-NTCDA, n-PTCDA, n-C60. Thus, in order to minimize the electron loss, we provide the structure of uniting two n-doped layers, cathode/ n-ETL2/ n-ETL1/ ETL. In p-i-n OLEDs, the hole current injected from the single p-doped hole transport layer (p-HTL) into the neat HTL must be limited, because the higher conductivity p-HTL has the higher lying highest occupied molecular orbital (HOMO) level, leading to a larger hole transport energy barrier (φB) at the interface with the neat HTL. Therefore, in order to minimize the hole loss, we suggest the structure of uniting two p-HTLs, anode/ p-HTL2/ p-HTL1/ HTL. The p-HTL2 possesses high-lying HOMO level and thereby high conductivity, decreasing the ohmic loss in the hole conduction; the p-HTL1 features a low-lying HOMO level, reducing the φB.

  17. Winter respiratory C losses provide explanatory power for net ecosystem productivity

    NASA Astrophysics Data System (ADS)

    Haeni, M.; Zweifel, R.; Eugster, W.; Gessler, A.; Zielis, S.; Bernhofer, C.; Carrara, A.; Grünwald, T.; Havránková, K.; Heinesch, B.; Herbst, M.; Ibrom, A.; Knohl, A.; Lagergren, F.; Law, B. E.; Marek, M.; Matteucci, G.; McCaughey, J. H.; Minerbi, S.; Montagnani, L.; Moors, E.; Olejnik, J.; Pavelka, M.; Pilegaard, K.; Pita, G.; Rodrigues, A.; Sanz Sánchez, M. J.; Schelhaas, M.-J.; Urbaniak, M.; Valentini, R.; Varlagin, A.; Vesala, T.; Vincke, C.; Wu, J.; Buchmann, N.

    2017-01-01

    Accurate predictions of net ecosystem productivity (NEPc) of forest ecosystems are essential for climate change decisions and requirements in the context of national forest growth and greenhouse gas inventories. However, drivers and underlying mechanisms determining NEPc (e.g., climate and nutrients) are not entirely understood yet, particularly when considering the influence of past periods. Here we explored the explanatory power of the compensation day (cDOY)—defined as the day of year when winter net carbon losses are compensated by spring assimilation—for NEPc in 26 forests in Europe, North America, and Australia, using different NEPc integration methods. We found cDOY to be a particularly powerful predictor for NEPc of temperate evergreen needleleaf forests (R2 = 0.58) and deciduous broadleaf forests (R2 = 0.68). In general, the latest cDOY correlated with the lowest NEPc. The explanatory power of cDOY depended on the integration method for NEPc, forest type, and whether the site had a distinct winter net respiratory carbon loss or not. The integration methods starting in autumn led to better predictions of NEPc from cDOY then the classical calendar method starting 1 January. Limited explanatory power of cDOY for NEPc was found for warmer sites with no distinct winter respiratory loss period. Our findings highlight the importance of the influence of winter processes and the delayed responses of previous seasons' climatic conditions on current year's NEPc. Such carry-over effects may contain information from climatic conditions, carbon storage levels, and hydraulic traits of several years back in time.

  18. Use of Transition Modeling to Enable the Computation of Losses for Variable-Speed Power Turbine

    NASA Technical Reports Server (NTRS)

    Ameri, Ali A.

    2012-01-01

    To investigate the penalties associated with using a variable speed power turbine (VSPT) in a rotorcraft capable of vertical takeoff and landing, various analysis tools are required. Such analysis tools must be able to model the flow accurately within the operating envelope of VSPT. For power turbines low Reynolds numbers and a wide range of the incidence angles, positive and negative, due to the variation in the shaft speed at relatively fixed corrected flows, characterize this envelope. The flow in the turbine passage is expected to be transitional and separated at high incidence. The turbulence model of Walters and Leylek was implemented in the NASA Glenn-HT code to enable a more accurate analysis of such flows. Two-dimensional heat transfer predictions of flat plate flow and two-dimensional and three-dimensional heat transfer predictions on a turbine blade were performed and reported herein. Heat transfer computations were performed because it is a good marker for transition. The final goal is to be able to compute the aerodynamic losses. Armed with the new transition model, total pressure losses for three-dimensional flow of an Energy Efficient Engine (E3) tip section cascade for a range of incidence angles were computed in anticipation of the experimental data. The results obtained form a loss bucket for the chosen blade.

  19. Power-law ansatz in complex systems: Excessive loss of information

    NASA Astrophysics Data System (ADS)

    Tsai, Sun-Ting; Chang, Chin-De; Chang, Ching-Hao; Tsai, Meng-Xue; Hsu, Nan-Jung; Hong, Tzay-Ming

    2015-12-01

    The ubiquity of power-law relations in empirical data displays physicists' love of simple laws and uncovering common causes among seemingly unrelated phenomena. However, many reported power laws lack statistical support and mechanistic backings, not to mention discrepancies with real data are often explained away as corrections due to finite size or other variables. We propose a simple experiment and rigorous statistical procedures to look into these issues. Making use of the fact that the occurrence rate and pulse intensity of crumple sound obey a power law with an exponent that varies with material, we simulate a complex system with two driving mechanisms by crumpling two different sheets together. The probability function of the crumple sound is found to transit from two power-law terms to a bona fide power law as compaction increases. In addition to showing the vicinity of these two distributions in the phase space, this observation nicely demonstrates the effect of interactions to bring about a subtle change in macroscopic behavior and more information may be retrieved if the data are subject to sorting. Our analyses are based on the Akaike information criterion that is a direct measurement of information loss and emphasizes the need to strike a balance between model simplicity and goodness of fit. As a show of force, the Akaike information criterion also found the Gutenberg-Richter law for earthquakes and the scale-free model for a brain functional network, a two-dimensional sandpile, and solar flare intensity to suffer an excessive loss of information. They resemble more the crumpled-together ball at low compactions in that there appear to be two driving mechanisms that take turns occurring.

  20. Power-law ansatz in complex systems: Excessive loss of information.

    PubMed

    Tsai, Sun-Ting; Chang, Chin-De; Chang, Ching-Hao; Tsai, Meng-Xue; Hsu, Nan-Jung; Hong, Tzay-Ming

    2015-12-01

    The ubiquity of power-law relations in empirical data displays physicists' love of simple laws and uncovering common causes among seemingly unrelated phenomena. However, many reported power laws lack statistical support and mechanistic backings, not to mention discrepancies with real data are often explained away as corrections due to finite size or other variables. We propose a simple experiment and rigorous statistical procedures to look into these issues. Making use of the fact that the occurrence rate and pulse intensity of crumple sound obey a power law with an exponent that varies with material, we simulate a complex system with two driving mechanisms by crumpling two different sheets together. The probability function of the crumple sound is found to transit from two power-law terms to a bona fide power law as compaction increases. In addition to showing the vicinity of these two distributions in the phase space, this observation nicely demonstrates the effect of interactions to bring about a subtle change in macroscopic behavior and more information may be retrieved if the data are subject to sorting. Our analyses are based on the Akaike information criterion that is a direct measurement of information loss and emphasizes the need to strike a balance between model simplicity and goodness of fit. As a show of force, the Akaike information criterion also found the Gutenberg-Richter law for earthquakes and the scale-free model for a brain functional network, a two-dimensional sandpile, and solar flare intensity to suffer an excessive loss of information. They resemble more the crumpled-together ball at low compactions in that there appear to be two driving mechanisms that take turns occurring.

  1. Development of a current collection loss management system for SDI homopolar power supplies

    SciTech Connect

    Brown, D.W.

    1989-01-01

    High speed, high power density current collection systems have been identified as an enabling technology required to construct homopolar power supplies to meet SDI missions. This work is part of a three-year effort directed towards the analysis, experimental verification, and prototype construction of a current collection system designed to operate continuously at 2 kA/cm{sup 2}, at a rubbing speed of 200 m/s, and with acceptable losses in a space environment. To data, no system has achieved these conditions simultaneously. This is the annual report covering the second year period of performance on DOE contract DE-AC03-86SF16518. Major areas covered include design, construction and operation of a cryogenically cooled brush test rig, design and construction of a high speed brush test rig, optimization study for homopolar machines, loss analysis of the current collection system, and an application study which defines the air-core homopolar construction necessary to achieve the goal of 80--90 kW/kg generator power density. 17 figs., 2 tabs.

  2. Impact of high power and angle of incidence on prism corrections for visual field loss

    NASA Astrophysics Data System (ADS)

    Jung, Jae-Hyun; Peli, Eli

    2014-06-01

    Prism distortions and spurious reflections are not usually considered when prescribing prisms to compensate for visual field loss due to homonymous hemianopia. Distortions and reflections in the high-power Fresnel prisms used in peripheral prism placement can be considerable, and the simplifying assumption that prism deflection power is independent of angle of incidence into the prisms results in substantial errors. We analyze the effects of high prism power and incidence angle on the field expansion, size of the apical scotomas, and image compression/expansion. We analyze and illustrate the effects of reflections within the Fresnel prisms, primarily due to reflections at the bases, and secondarily due to surface reflections. The strength and location of these effects differs materially depending on whether the serrated prismatic surface is placed toward or away from the eye, and this affects the contribution of the reflections to visual confusion, diplopia, false alarms, and loss of contrast. We conclude with suggestions for controlling and mitigating these effects in clinical practice.

  3. Development of a current collection loss management system for SDI homopolar power supplies

    NASA Astrophysics Data System (ADS)

    Brown, D. W.

    1991-04-01

    High speed, high power density current collection systems have been identified as an enabling technology required to construct homopolar power supplies to meet SDI missions. This work is part of a three-year effort directed towards the analysis, experimental verification, and prototype construction of a current collection system designed to operate continuously at 2 kA/sq cm, at a rubbing speed of 200 m/s, and with acceptable losses in a space environment. To date, no system has achieved these conditions simultaneously. This is the final report covering the three year period of performance on DOE contract AC03-86SF-16518. Major areas covered include design, construction and operation of a cryogenically cooled brush test rig, design and construction of a high speed brush test rig, optimization study for homopolar machines, loss analysis of the current collection system, and an application study which defines the air-core homopolar construction necessary to achieve the goal of 80 kW/kg generator power density.

  4. Development of a current collection loss management system for SDI homopolar power supplies

    SciTech Connect

    Hannan, W.F. III.

    1987-01-01

    High speed, high power density current collection systems have been identified as an enabling technology required to construct homopolar power supplies to meet SDI missions. This work is part of a three-year effort directed towards the analysis, experimental verification, and prototype construction of a current collection system designed to operated continuously at 2 kA/cm{sup 2}, at a rubbing speed of 200 m/s, and with acceptable losses in a space environment. To data, no system has achieved these conditions simultaneously. This is the annual report covering the first year period of performance on DOE contract DE-AC03-86SF16518. Major areas covered include design and construction of a cryogenically-cooled brush test rig, design of a high speed brush test rig, loss analysis of the current collection system, and an application study which defines the air core homopolar construction necessary to achieve the goal of 80--90 kW/kg generator power density. 15 figs.

  5. Convection heat loss from cavity receiver in parabolic dish solar thermal power system: A review

    SciTech Connect

    Wu, Shuang-Ying; Xiao, Lan; Li, You-Rong; Cao, Yiding

    2010-08-15

    The convection heat loss from cavity receiver in parabolic dish solar thermal power system can significantly reduce the efficiency and consequently the cost effectiveness of the system. It is important to assess this heat loss and subsequently improve the thermal performance of the receiver. This paper aims to present a comprehensive review and systematic summarization of the state of the art in the research and progress in this area. The efforts include the convection heat loss mechanism, experimental and numerical investigations on the cavity receivers with varied shapes that have been considered up to date, and the Nusselt number correlations developed for convection heat loss prediction as well as the wind effect. One of the most important features of this paper is that it has covered numerous cavity literatures encountered in various other engineering systems, such as those in electronic cooling devices and buildings. The studies related to those applications may provide valuable information for the solar receiver design, which may otherwise be ignored by a solar system designer. Finally, future development directions and the issues that need to be further investigated are also suggested. It is believed that this comprehensive review will be beneficial to the design, simulation, performance assessment and applications of the solar parabolic dish cavity receivers. (author)

  6. 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

  7. 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

  8. Loss Analysis of High Power Stirling-Type Pulse Tube Cryocooler

    NASA Astrophysics Data System (ADS)

    Nakano, K.; Hiratsuka, Y.

    2015-12-01

    For the purpose of cooling high-temperature superconductor (HTS) devices, such as superconductor motors, superconducting magnetic energy storage (SMES) and current fault limiters, cryocoolers should be compact in size, light-weight, and have high efficiency and reliability. In order to meet the demand of HTS devices world-wide, the cryocooler needs to have COP efficiency >0.1. We have developed a high power Stirling-type pulse tube cryocooler (SPTC) with an in-line expander. The experimental results were reported in June 2012[1]. The cooling capacity was 210 W at 77 K and the minimum temperature was 37 K when the compressor input power was 3.8 kW. Accordingly, the COP was about 0.055. To further improve the efficiency, the energy losses in the cryocooler were analyzed. The experimental results and the numerical calculation results are reported in this paper.

  9. Measurements of the Ech Power and of the Transmission Line Losses on Diii-D

    NASA Astrophysics Data System (ADS)

    Cengher, M.; Lohr, J.; Gorelov, I. A.; Grosnickle, W. H.; Ponce, D.; Johnson, P.

    2009-04-01

    The measurement of the power injected by the electron cyclotron heating (ECH) system in the DIII-D tokamak is a critical requirement for analysis of experiments, for tuning the gyrotrons for maximum power and efficiency, for tracking long-term operational trends and for providing a warning of problems with the system. The ECH system at General Atomics consists of six 110 GHz, 1 MW class gyrotrons. The rf power generated by each gyrotron is determined from calorimetry, using the relevant temperature and flow measurements from the cooling circuits of cavity, matching optics unit and dummy loads. The rf pulse length and time dependence are measured using an rf monitor at the first miter bend in the transmission line. The direct measurement of the efficiencies of four of the transmission lines was performed using a high power, small dummy load (SDL) placed alternately in 2 positions of each DIII-D waveguide line, at accessible points close the beginning and the end of each line. Total losses in the transmission lines range from 21.2% to 30.7%. Experimental results are compared to theoretical predictions of the performance of the components and waveguide lines.

  10. A flexible active and reactive power control strategy for a variable speed constant frequency generating system

    SciTech Connect

    Tang, Y.; Xu, L.

    1995-07-01

    Variable-speed constant-frequency generating systems are used in wind power, hydro power, aerospace, and naval power generations to enhance efficiency and reduce friction. In these applications, an attractive candidate is the slip power recovery system comprising of doubly excited induction machine or doubly excited brushless reluctance machine and PWM converters with a dc link. In this paper, a flexible active and reactive power control strategy is developed, such that the optimal torque-speed profile of the turbine can be followed and overall reactive power can be controlled, while the machine copper losses have been minimized. At the same time, harmonics injected into the power network has also been minimized. In this manner, the system can function as both a high-efficient power generator and a flexible reactive power compensator.

  11. In-Situ Measurement of Power Loss for Crystalline Silicon Modules Undergoing Thermal Cycling and Mechanical Loading Stress Testing: Preprint

    SciTech Connect

    Spataru, Sergiu; Hacke, Pater; Sera, Dezso

    2015-09-15

    We analyze the degradation of multi-crystalline silicon photovoltaic modules undergoing simultaneous thermal, mechanical, and humidity stress testing to develop a dark environmental chamber in-situ measurement procedure for determining module power loss. From the analysis we determine three main categories of failure modes associated with the module degradation consisting of: shunting, recombination losses, increased series resistance losses, and current mismatch losses associated with a decrease in photo-current generation by removal of some cell areas due to cell fractures. Based on the analysis, we propose an in-situ module power loss monitoring procedure that relies on dark current-voltage measurements taken during the stress test, and initial and final module flash testing, to determine the power degradation characteristic of the module.

  12. Mass Loss from the Nuclei of Active Galaxies

    NASA Technical Reports Server (NTRS)

    Crenshaw, Michael; Kraemer, Steven B.; George, Ian M.

    2003-01-01

    Blueshifted absorption lines in the UV and X-ray spectra of active galaxies reveal the presence of massive outflows of ionized gas from their nuclei. The intrinsic UV and X-ray absorbers show large global covering factors of the central continuum source, and the inferred mass loss rates are comparable to the mass accretion rates. Many absorbers show variable ionic column densities which are attributed to a combination of variable ionizing flux and motion of gas into and out of the line of sight . Detailed studies of the intrinsic absorbers. with the assistance of monitoring observations and photoionization models. provide constraints on their kinematics] physical conditions. and locations relative to the central continuum source. which range from the inner nucleus (approx.0.01 pc) to the galactic disk or halo (approx.10 kpc) . Dynamical models that make use of thermal winds. radiation pressure. and/or hydromagnetic flows have reached a level of sophistication that permits comparisons with the observational constraints .

  13. Complex additive systems for Mn-Zn ferrites with low power loss

    SciTech Connect

    Töpfer, J. Angermann, A.

    2015-05-07

    Mn-Zn ferrites were prepared via an oxalate-based wet-chemical synthesis process. Nanocrystalline ferrite powders with particle size of 50 nm were sintered at 1150 °C with 500 ppm CaO and 100 ppm SiO{sub 2} as standard additives. A fine-grained, dense microstructure with grain size of 4–5 μm was obtained. Simultaneous addition of Nb{sub 2}O{sub 5}, ZrO{sub 2}, V{sub 2}O{sub 5}, and SnO{sub 2} results low power losses, e.g., 65 mW/cm{sup 3} (500 kHz, 50 mT, 80 °C) and 55 mW/cm{sup 3} (1 MHz, 25 mT, 80 °C). Loss analysis shows that eddy current and residual losses were minimized through formation of insulating grain boundary phases, which is confirmed by transmission electron microscopy. Addition of SnO{sub 2} increases the ferrous ion concentration and affects anisotropy as reflected in permeability measurements μ(T)

  14. Poynting flux in the neighbourhood of a point charge in arbitrary motion and radiative power losses

    NASA Astrophysics Data System (ADS)

    Singal, Ashok K.

    2016-07-01

    We examine the electromagnetic fields in the neighbourhood of a ‘point charge’ in arbitrary motion and thereby determine the Poynting flux across a spherical surface of vanishingly small radius surrounding the charge. We show that the radiative power losses from a point charge turn out to be proportional to the scalar product of the instantaneous velocity and the first time-derivative of the acceleration of the charge. This may seem to be discordant with the familiar Larmor formula where the instantaneous power radiated from a charge is proportional to the square of acceleration. However, it seems that the root cause of the discrepancy actually lies in Larmor’s formula, which is derived using the acceleration fields but without due consideration for the Poynting flux associated with the velocity-dependent self-fields ‘co-moving’ with the charge. Further, while deriving Larmor’s formula, one equates the Poynting flux through a surface at some later time to the radiation loss by the enclosed charge at the retarded time. Poynting’s theorem, on the other hand, relates the outgoing radiation flux from a closed surface to the rate of energy decrease within the enclosed volume, all calculated for the same given instant only. Here we explicitly show the absence of any Poynting flux in the neighbourhood of an instantly stationary point charge, implying no radiative losses from such a charge, which is in complete conformity with energy conservation. We further show how Larmor’s formula is still able to serve our purpose in the vast majority of cases. It is further shown that Larmor’s formula in general violates momentum conservation and, in the case of synchrotron radiation, leads to a potentially incorrect conclusion about the pitch angle changes of the radiating charges, and that only the radiation reaction formula yields a correct result, consistent with special relativity.

  15. Practical Considerations For Optical Power Loss Measurements During Outside Plant Installations

    NASA Astrophysics Data System (ADS)

    Grebe, Robert K.; Caron, Bernard G.

    1984-08-01

    The techniques for predicting total transmission system losses in a fiber optic cable installation involving multiple splices are relatively well known, and significant work has been done in the field of laboratory measurement techniques for quantifying cable (fiber) characteristics and performance characteristics of splices and connectors. The shift of this technology from the laboratory to the actual environment of a field installation, however, poses some significantly different problems to the user of fiber optic cables and splices. The basic instrument available for field use in testing optical links is the Optical-Time-Domain-Reflectometer (OTDR). An OTDR can be used to check the loss profile (dB/km) of a fiber within a cable prior to the cable installation, and to locate installation induced faults in the cable. The capability of the OTDR above to characterize splice losses in an actual installation can be significantly degraded depending on the location of the splice with respect to cable faults, the length of the cable (fiber) run, the characteristics of the individual fibers being spliced, and the ability of the OTDR operator to interpret the-data the instrument is presenting. By following some specific procedures regarding the sequence of installation and testing, and through better understanding of the performance of optical fibers and splices where actually installed in the outside plant environment, installation crews can significantly reduce installation time and time lost because of faults in an individual link that must be reworked. Addi-tional testing with instruments specifically intended for optical power measurement can provide a realistic basis for evaluation of the overall performance of a completely installed link and will give the transmission engineer a solid reference base for use in system set-up in addition to evaluation of system deterioration. Records made through OTDR measurements and optical power instrument readings can be used to

  16. Self-Directed Weight Loss Strategies: Energy Expenditure Due to Physical Activity Is Not Increased to Achieve Intended Weight Loss

    PubMed Central

    Elbelt, Ulf; Schuetz, Tatjana; Knoll, Nina; Burkert, Silke

    2015-01-01

    Reduced physical activity and almost unlimited availability of food are major contributors to the development of obesity. With the decline of strenuous work, energy expenditure due to spontaneous physical activity has attracted increasing attention. Our aim was to assess changes in energy expenditure, physical activity patterns and nutritional habits in obese subjects aiming at self-directed weight loss. Methods: Energy expenditure and physical activity patterns were measured with a portable armband device. Nutritional habits were assessed with a food frequency questionnaire. Results: Data on weight development, energy expenditure, physical activity patterns and nutritional habits were obtained for 105 patients over a six-month period from an initial cohort of 160 outpatients aiming at weight loss. Mean weight loss was −1.5 ± 7.0 kg (p = 0.028). Patients with weight maintenance (n = 75), with substantial weight loss (>5% body weight, n = 20) and with substantial weight gain (>5% body weight, n = 10) did not differ in regard to changes of body weight adjusted energy expenditure components (total energy expenditure: −0.2 kcal/kg/day; non-exercise activity thermogenesis: −0.3 kcal/kg/day; exercise-related activity thermogenesis (EAT): −0.2 kcal/kg/day) or patterns of physical activity (duration of EAT: −2 min/day; steps/day: −156; metabolic equivalent unchanged) measured objectively with a portable armband device. Self-reported consumption frequency of unfavorable food decreased significantly (p = 0.019) over the six-month period. Conclusions: An increase in energy expenditure or changes of physical activity patterns (objectively assessed with a portable armband device) are not employed by obese subjects to achieve self-directed weight loss. However, modified nutritional habits could be detected with the use of a food frequency questionnaire. PMID:26193310

  17. Relationship of Physical Activity to Eating Behaviors and Weight Loss in Women.

    ERIC Educational Resources Information Center

    Jakicic, John M.; Wing, Rena R.; Winters-Hart, Carena

    2002-01-01

    Examined whether change in physical activity would relate to compliance with changes in dietary intake and eating behaviors in an 18-month behavioral weight loss program, also noting the contribution of exercise to weight loss. Data on 104 women indicated that physical activity related to long-term weight loss and was part of a constellation of…

  18. Control designs for low-loss active magnetic bearings: Theory and implementation

    NASA Astrophysics Data System (ADS)

    Wilson, Brian Christopher David

    Active Magnetic Bearings (AMB) have been proposed for use in Electromechanical Flywheel Batteries. In these devices, kinetic energy is stored in a magnetically levitated flywheel which spins in a vacuum. The AMB eliminates all mechanical losses, however, electrical loss, which is proportional to the square of the magnetic flux, is still significant. For efficient operation, the flux bias, which is typically introduced into the electromagnets to improve the AMB stiffness, must be reduced, preferably to zero. This zero-bias (ZB) mode of operation cripples the classical control techniques which are customarily used and nonlinear control is required. As a compromise between AMB stiffness and efficiency, a new flux bias scheme is proposed called the generalized complementary flux condition (gcfc). A flux-bias dependent trade-off exists between AMB stiffness, power consumption, and power loss. This work theoretically develops and experimentally verifies new low-loss AMB control designs which employ the gcfc condition. Particular attention is paid to the removal of the singularity present in the standard nonlinear control techniques when operating in ZB. Experimental verification is conduced on a 6-DOF AMB reaction wheel. Practical aspects of the gcfc implementation such as flux measurement and flux-bias implementation with voltage mode amplifiers using IR compensation are investigated. Comparisons are made between the gcfc bias technique and the standard constant-flux-sum (cfs) bias method. Under typical operating circumstances, theoretical analysis and experimental data show that the new gcfc bias scheme is more efficient in producing the control flux required for rotor stabilization than the ordinary cfs bias strategy.

  19. Minimalist coupled evolution model for stellar X-ray activity, rotation, mass loss, and magnetic field

    NASA Astrophysics Data System (ADS)

    Blackman, Eric G.; Owen, James E.

    2016-05-01

    Late-type main-sequence stars exhibit an X-ray to bolometric flux ratio that depends on {tilde{R}o}, the ratio of rotation period to convective turnover time, as {tilde{R}o}^{-ζ } with 2 ≤ ζ ≤ 3 for {tilde{R}o} > 0.13, but saturates with |ζ| < 0.2 for {tilde{R}o} < 0.13. Saturated stars are younger than unsaturated stars and show a broader spread of rotation rates and X-ray activity. The unsaturated stars have magnetic fields and rotation speeds that scale roughly with the square root of their age, though possibly flattening for stars older than the Sun. The connection between faster rotators, stronger fields, and higher activity has been established observationally, but a theory for the unified time-evolution of X-ray luminosity, rotation, magnetic field and mass loss that captures the above trends has been lacking. Here we derive a minimalist holistic framework for the time evolution of these quantities built from combining a Parker wind with new ingredients: (1) explicit sourcing of both the thermal energy launching the wind and the X-ray luminosity via dynamo produced magnetic fields; (2) explicit coupling of X-ray activity and mass-loss saturation to dynamo saturation (via magnetic helicity build-up and convection eddy shredding); (3) use of coronal equilibrium to determine how magnetic energy is divided into wind and X-ray contributions. For solar-type stars younger than the Sun, we infer conduction to be a subdominant power loss compared to X-rays and wind. For older stars, conduction is more important, possibly quenching the wind and reducing angular momentum loss. We focus on the time evolution for stars younger than the Sun, highlighting what is possible for further generalizations. Overall, the approach shows promise towards a unified explanation of all of the aforementioned observational trends.

  20. 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.

  1. 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.

  2. Reducing start-up time and minimizing energy losses of Microbial Fuel Cells using Maximum Power Point Tracking strategy

    NASA Astrophysics Data System (ADS)

    Molognoni, Daniele; Puig, Sebastià; Balaguer, M. Dolors; Liberale, Alessandro; Capodaglio, Andrea G.; Callegari, Arianna; Colprim, Jesús

    2014-12-01

    Microbial Fuel Cells (MFCs) are considered to be an environmental friendly energy conversion technology. The main limitations that delay their industrialization include low current and power densities achievable and long start-up times. Maximum Power Point Tracking (MPPT) has been proposed as a method to enhance MFCs electrical performances. However, the specialized literature is still lacking of experimental works on scaled-up reactors and/or real wastewater utilization. This study evaluates the impact of a MPPT system applied to MFCs treating swine wastewater in terms of start-up time and long-term performance. For this purpose, two replicate cells were compared, one with applied MPPT control and one working with fixed resistance. Both MFCs were continuously fed with swine wastewater to validate the control system under real and dynamic conditions. The study demonstrated that the automatic resistance control was able to reduce the start-up time of about one month. Moreover, MPPT system increased of 40% the Coulombic efficiency at steady-state conditions, reduced energy losses associated with anode and cathode reactions and limited methanogenic activity in the anode chamber. A power density of 5.0 ± 0.2 W m-3 NAC was achieved feeding the system at an organic loading rate of 10 kg COD m-3 d-1.

  3. RHF RELAP5 model and preliminary loss-of-offsite-power simulation results for LEU conversion

    SciTech Connect

    Licht, J. R.; Bergeron, A.; Dionne, B.; Thomas, F.

    2014-08-01

    The purpose of this document is to describe the current state of the RELAP5 model for the Institut Laue-Langevin High Flux Reactor (RHF) located in Grenoble, France, and provide an update to the key information required to complete, for example, simulations for a loss of offsite power (LOOP) accident. A previous status report identified a list of 22 items to be resolved in order to complete the RELAP5 model. Most of these items have been resolved by ANL and the RHF team. Enough information was available to perform preliminary safety analyses and define the key items that are still required. Section 2 of this document describes the RELAP5 model of RHF. The final part of this section briefly summarizes previous model issues and resolutions. Section 3 of this document describes preliminary LOOP simulations for both HEU and LEU fuel at beginning of cycle conditions.

  4. An experimental study of energy loss mechanisms and efficiency considerations in the low power dc arcjet

    NASA Technical Reports Server (NTRS)

    Curran, F. M.

    1985-01-01

    The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30 percent of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage.

  5. An experimental study of energy loss mechanisms and efficiency consideration in the low power dc arcjet

    NASA Technical Reports Server (NTRS)

    Curran, F. M.

    1985-01-01

    The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30% of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage.

  6. Determination analaysis of the power losses of transformers with continuously transpored conductors (CTC) based fuzzy logic

    NASA Astrophysics Data System (ADS)

    Kaloko, Bambang Sri; Atsari, Erinna Dyah

    2017-03-01

    Electric motive force which flows into the iron core continuously on a plate - plate iron isolated may cause heat posed by current eddy (eddy current). No water loss occurs due to detainees on the circuit at the the flow of current load because this loss happened on the entanglement of the transformer is made of copper. Continuously Transposed Conductors (CTC) consist of a number of enameled rectangular wires (5-84 strands) made into an assembly. Each strand is transposed in turn to each position in the cable and is then covered with layers of insulation paper. Continuously Transposed Conductors are used in winding wires for medium and ultra high power transformers. CTC is manufactured by OFHC copper and indeed, is able to supply polyester roped. CTC which has been designed to reduce production cost, oil pocket and improve cooling efficiency. Hardened type CTC (CPR1, CPR2, and CPR3: BS1432) and Self-bonding CTC which can be used to improve mechanical and electrical strength are also available. This analysis is performed using the methods of fuzzy logic in taking account of the resources.

  7. Power requirement of the geodynamo from ohmic losses in numerical and laboratory dynamos.

    PubMed

    Christensen, Ulrich R; Tilgner, Andreas

    2004-05-13

    In the Earth's fluid outer core, a dynamo process converts thermal and gravitational energy into magnetic energy. The power needed to sustain the geomagnetic field is set by the ohmic losses (dissipation due to electrical resistance). Recent estimates of ohmic losses cover a wide range, from 0.1 to 3.5 TW, or roughly 0.3-10% of the Earth's surface heat flow. The energy requirement of the dynamo puts constraints on the thermal budget and evolution of the core through Earth's history. Here we use a set of numerical dynamo models to derive scaling relations between the core's characteristic dissipation time and the core's magnetic and hydrodynamic Reynolds numbers--dimensionless numbers that measure the ratio of advective transport to magnetic and viscous diffusion, respectively. The ohmic dissipation of the Karlsruhe dynamo experiment supports a simple dependence on the magnetic Reynolds number alone, indicating that flow turbulence in the experiment and in the Earth's core has little influence on its characteristic dissipation time. We use these results to predict moderate ohmic dissipation in the range of 0.2-0.5 TW, which removes the need for strong radioactive heating in the core and allows the age of the solid inner core to exceed 2.5 billion years.

  8. Impact of Uncertainty on Calculations for Recovery from Loss of Offsite Power

    SciTech Connect

    Dana L. Kelly

    2010-06-01

    Uncertainty, both aleatory and epistemic, can have a significant impact on estimated probabilities of recovering from loss of offsite power within a specified time window, and such probabilities are an input to risk-informed decisions as to the significance of inspection findings in the U.S. Nuclear Regulatory Commission’s Reactor Oversight Process. In particular, the choice of aleatory model for offsite power recovery time can have a significant impact on the estimated nonrecovery probability, especially if epistemic uncertainty regarding parameters in the aleatory model is accounted for properly. In past and current analyses, such uncertainty has largely been ignored. This paper examines the impact of both aleatory and epistemic uncertainty on the results, using modern open-source Bayesian inference software, which implements Markov chain Monte Carlo sampling. It includes examples of time-dependent convolution calculations to show the impact that uncertainty can have on this increasingly frequent type of calculation, also. The results show that the “point estimate” result, which is an input to risk-informed decisions, can easily be uncertain by a factor of 10 if both aleatory and epistemic uncertainties are considered. The paper also illustrates the use of Bayesian model selection criteria to aid in the choice of aleatory model.

  9. Computer Simulations of Contributions of Néel and Brown Relaxation to Specific Loss Power of Magnetic Fluids in Hyperthermia

    NASA Astrophysics Data System (ADS)

    Phong, Pham Thanh; Nguyen, Luu Huu; Manh, Do Hung; Lee, In-Ja; Phuc, Nguyen Xuan

    2017-04-01

    In this study, the degree of the contribution of particular relaxation losses to the specific loss power are calculated for a number of magnetic fluids, including Fe3O4, CoFe2O4, MnFe2O4, FeCo, FePt and La0.7Sr0.3MnO3 nanoparticles in various viscosities. We found that the specific loss of every fluid studied increases linearly with particle saturation magnetization. The competition between Néel and Brownian relaxation contributions gives rise to a peak at a critical diameter in the plot of specific loss power versus diameter. The critical diameter does not change with saturation magnetization but monotonically decreases with increasing magnetic anisotropy. If particle diameter is smaller than 6-11 nm, the maximum loss power tends to diminish and the heating effect to switch off. According to how the materials respond to viscosity change, the hyperthermia materials can be classified into two groups. One is hard nanoparticles with high anisotropy of which the critical diameter decreases with viscosity and the specific loss power versus saturation magnetization rate decreases strongly. The other is soft nanoparticles with low anisotropy of which the properties are insensitive to the viscosity of the fluid. We discuss our simulated results in relation to recent experimental findings.

  10. 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.

  11. The role of exercise and physical activity in weight loss and maintenance.

    PubMed

    Swift, Damon L; Johannsen, Neil M; Lavie, Carl J; Earnest, Conrad P; Church, Timothy S

    2014-01-01

    This review explores the role of physical activity (PA) and exercise training (ET) in the prevention of weight gain, initial weight loss, weight maintenance, and the obesity paradox. In particular, we will focus the discussion on the expected initial weight loss from different ET programs, and explore intensity/volume relationships. Based on the present literature, unless the overall volume of aerobic ET is very high, clinically significant weight loss is unlikely to occur. Also, ET also has an important role in weight regain after initial weight loss. Overall, aerobic ET programs consistent with public health recommendations may promote up to modest weight loss (~2 kg), however the weight loss on an individual level is highly heterogeneous. Clinicians should educate their patients on reasonable expectations of weight loss based on their physical activity program and emphasize that numerous health benefits occur from PA programs in the absence of weight loss.

  12. Three dimensional numerical prediction of icing related power and energy losses on a wind turbine

    NASA Astrophysics Data System (ADS)

    Sagol, Ece

    Regions of Canada experience harsh winter conditions that may persist for several months. Consequently, wind turbines located in these regions are exposed to ice accretion and its adverse effects, from loss of power to ceasing to function altogether. Since the weather-related annual energy production loss of a turbine may be as high as 16% of the nominal production for Canada, estimating these losses before the construction of a wind farm is essential for investors. A literature survey shows that most icing prediction methods and codes are developed for aircraft, and, as this information is mostly considered corporate intellectual property, it is not accessible to researchers in other domains. Moreover, aircraft icing is quite different from wind turbine icing. Wind turbines are exposed to icing conditions for much longer periods than aircraft, perhaps for several days in a harsh climate, whereas the maximum length of exposure of an aircraft is about 3-4 hours. In addition, wind turbine blades operate at subsonic speeds, at lower Reynolds numbers than aircraft, and their physical characteristics are different. A few icing codes have been developed for wind turbine icing nevertheless. However, they are either in 2D, which does not consider the 3D characteristics of the flow field, or they focus on simulating each rotation in a time-dependent manner, which is not practical for computing long hours of ice accretion. Our objective in this thesis is to develop a 3D numerical methodology to predict rime ice shape and the power loss of a wind turbine as a function of wind farm icing conditions. In addition, we compute the Annual Energy Production of a sample turbine under both clean and icing conditions. The sample turbine we have selected is the NREL Phase VI experimental wind turbine installed on a wind farm in Sweden, the icing events at which have been recorded and published. The proposed method is based on computing and validating the clean performance of the turbine

  13. Heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter

    NASA Astrophysics Data System (ADS)

    Sung, Hae-Jin; Go, Byeong-Soo; Jiang, Zhenan; Park, Minwon; Yu, In-Keun

    2016-11-01

    The development of an effective high-temperature superconducting (HTS) generator is currently a research focus; however, the reduction of heat loss of a large-scale HTS generator is a challenge. This study deals with a heat loss analysis-based design of a 12 MW wind power generator module having an HTS flux pump exciter. The generator module consists of an HTS rotor of the generator and an HTS flux pump exciter. The specifications of the module were described, and the detailed configuration of the module was illustrated. For the heat loss analysis of the module, the excitation loss of the flux pump exciter, eddy current loss of all of the structures in the module, radiation loss, and conduction loss of an HTS coil supporter were assessed using a 3D finite elements method program. In the case of the conduction loss, different types of the supporters were compared to find out the supporter of the lowest conduction loss in the module. The heat loss analysis results of the module were reflected in the design of the generator module and discussed in detail. The results will be applied to the design of large-scale superconducting generators for wind turbines including a cooling system.

  14. 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.

  15. IMPLICATIONS OF MASS AND ENERGY LOSS DUE TO CORONAL MASS EJECTIONS ON MAGNETICALLY ACTIVE STARS

    SciTech Connect

    Drake, Jeremy J.; Cohen, Ofer; Yashiro, Seiji; Gopalswamy, Nat

    2013-02-20

    Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 A flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE {sup -{alpha}}. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of {alpha} and are very large: M-dot {approx}5 Multiplication-Sign 10{sup -10} M{sub sun} yr{sup -1} and E-dot {approx}0.1 L{sub sun}. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence {approx}> 10{sup 31} erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10{sup -3} L {sub bol} X-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of L {sub bol}, the CME mass loss rate is about 5 Multiplication-Sign 10{sup -11} M {sub Sun} yr{sup -1}.

  16. Computer Calculations of Eddy-Current Power Loss in Rotating Titanium Wheels and Rims in Localized Axial Magnetic Fields

    SciTech Connect

    Mayhall, D J; Stein, W; Gronberg, J B

    2006-05-15

    We have performed preliminary computer-based, transient, magnetostatic calculations of the eddy-current power loss in rotating titanium-alloy and aluminum wheels and wheel rims in the predominantly axially-directed, steady magnetic fields of two small, solenoidal coils. These calculations have been undertaken to assess the eddy-current power loss in various possible International Linear Collider (ILC) positron target wheels. They have also been done to validate the simulation code module against known results published in the literature. The commercially available software package used in these calculations is the Maxwell 3D, Version 10, Transient Module from the Ansoft Corporation.

  17. Assessment of hindlimb gait as a powerful indicator of axonal loss in a murine model of progressive CNS demyelination

    PubMed Central

    McGavern, Dorian B.; Zoecklein, Laurie; Sathornsumetee, Sith; Rodriguez, Moses

    2017-01-01

    Identifying the role of axonal injury in the development of permanent, irreversible neurologic disability is important to the study of central nervous system (CNS) demyelinating diseases. Our understanding of neurologic dysfunction in demyelinating diseases and the ability to assess therapeutic interventions depends on the development of objective functional assays that can non-invasively measure axonal loss. In this study, we demonstrate in a murine model of progressive CNS demyelination that assessment of the hindlimb width of stride provides a powerful indicator of axonal loss and can dissociate between deficits induced by demyelination versus axonal loss. PMID:10986359

  18. Design of low-loss 1-3 piezoelectric composites for high-power transducer applications.

    PubMed

    Lee, Hyeong Jae; Zhang, Shujun

    2012-09-01

    Lead zirconate titanate (PZT)/polymer 1-3 composites have improved electromechanical properties compared with monolithic counterparts, but possess a low mechanical quality factor, limiting their use in high-power transducer applications. The goal of this work was to improve the mechanical quality factor of 1-3 PZT/polymer composites by optimizing the polymer materials. Theoretical analysis and modeling were performed for optimum composite design and various polymers were prepared and characterized. 1-3 piezocomposites were constructed and their electromechanical properties were experimentally determined. The results demonstrated that the composites with high-thermal-conductivity polymers generally have degraded electromechanical properties with significantly decreased mechanical quality factors, whereas the composites filled with low-loss and low-moduli polymers were found to have higher mechanical quality factors with higher electromechanical coupling factors: Q(m) ~ 200 and k(t) ~ 0.68 for PZT4 composites; Q(m) ~ 400 and k(t) ~ 0.6 for PZT8 composites. The improved mechanical quality factor of 1-3 piezocomposites may offer improved performance and thermal stability of transducers under high-drive operation.

  19. Design of Low-Loss 1–3 Piezoelectric Composites for High-Power Transducer Applications

    PubMed Central

    Lee, Hyeong Jae; Zhang, Shujun

    2013-01-01

    Lead zirconate titanate (PZT)/polymer 1–3 composites have improved electromechanical properties compared with monolithic counterparts, but possess a low mechanical quality factor, limiting their use in high-power transducer applications. The goal of this work was to improve the mechanical quality factor of 1–3 PZT/polymer composites by optimizing the polymer materials. Theoretical analysis and modeling were performed for optimum composite design and various polymers were prepared and characterized. 1–3 piezocomposites were constructed and their electromechanical properties were experimentally determined. The results demonstrated that the composites with high-thermal-conductivity polymers generally have degraded electromechanical properties with significantly decreased mechanical quality factors, whereas the composites filled with low-loss and low-moduli polymers were found to have higher mechanical quality factors with higher electrome-chanical coupling factors: Qm ~ 200 and kt ~ 0.68 for PZT4 composites; Qm ~ 400 and kt ~ 0.6 for PZT8 composites. The improved mechanical quality factor of 1–3 piezocomposites may offer improved performance and thermal stability of transducers under high-drive operation. PMID:23007769

  20. Novel platform for minimizing cell loss on separation process: Droplet-based magnetically activated cell separator

    NASA Astrophysics Data System (ADS)

    Kim, Youngho; Hong, Su; Lee, Sang Ho; Lee, Kangsun; Yun, Seok; Kang, Yuri; Paek, Kyeong-Kap; Ju, Byeong-Kwon; Kim, Byungkyu

    2007-07-01

    To reduce the problem of cell loss due to adhesion, one of the basic phenomena in microchannel, we proposed the droplet-based magnetically activated cell separator (DMACS). Based on the platform of the DMACS—which consists of permanent magnets, a coverslip with a circle-shaped boundary, and an injection tube—we could collect magnetically (CD45)-labeled (positive) cells with high purity and minimize cell loss due to adhesion. To compare separation efficiency between the MACS and the DMACS, the total number of cells before and after separation with both the separators was counted by flow cytometry. We could find that the number (3241/59940) of cells lost in the DMACS is much less than that (22360/59940) in the MACS while the efficiency of cell separation in the DMACS (96.07%) is almost the same as that in the MACS (96.72%). Practically, with fluorescent images, it was visually confirmed that the statistical data are reliable. From the viability test by using Hoechst 33 342, it was also demonstrated that there was no cell damage on a gas-liquid interface. Conclusively, DMACS will be a powerful tool to separate rare cells and applicable as a separator, key component of lab-on-a-chip.

  1. Antioxidative activity of barley hordein and its loss by deamidation.

    PubMed

    Chiue, H; Kusano, T; Iwami, K

    1997-02-01

    Barley hordein was comparable to maize zein in antioxidation under a powder model system. Various deamidated "hordein" preparations were obtained and examined for their molecular-size distribution (by Sephacryl S-100 gel filtration), hydrophobicity (by fluorescence measurement using fluorescent probes) and antioxidative activity (by the ferric thiocyanate method). Deamidation caused fragmentation of the hordein molecule and simultaneously lowered its fatty acid-binding capacity rather than its surface hydrophobicity. Then, the antioxidative activity diminished with increasing deamidation. When the fatty acid-binding capacity was plotted against the antioxidative activity, a high correlation (r2 = 0.92) was observed between these two events.

  2. Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators.

    PubMed

    Bernardi, Michael P; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

    2015-06-26

    The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses.

  3. Impacts of propagating, frustrated and surface modes on radiative, electrical and thermal losses in nanoscale-gap thermophotovoltaic power generators

    PubMed Central

    Bernardi, Michael P.; Dupré, Olivier; Blandre, Etienne; Chapuis, Pierre-Olivier; Vaillon, Rodolphe; Francoeur, Mathieu

    2015-01-01

    The impacts of radiative, electrical and thermal losses on the performances of nanoscale-gap thermophotovoltaic (nano-TPV) power generators consisting of a gallium antimonide cell paired with a broadband tungsten and a radiatively-optimized Drude radiator are analyzed. Results reveal that surface mode mediated nano-TPV power generation with the Drude radiator outperforms the tungsten radiator, dominated by frustrated modes, only for a vacuum gap thickness of 10 nm and if both electrical and thermal losses are neglected. The key limiting factors for the Drude- and tungsten-based devices are respectively the recombination of electron-hole pairs at the cell surface and thermalization of radiation with energy larger than the cell absorption bandgap. A design guideline is also proposed where a high energy cutoff above which radiation has a net negative effect on nano-TPV power output due to thermal losses is determined. It is shown that the power output of a tungsten-based device increases by 6.5% while the cell temperature decreases by 30 K when applying a high energy cutoff at 1.45 eV. This work demonstrates that design and optimization of nano-TPV devices must account for radiative, electrical and thermal losses. PMID:26112658

  4. Sustained mitogen-activated protein kinase activation with Aggregatibacter actinomycetemcomitans causes inflammatory bone loss.

    PubMed

    Dunmyer, J; Herbert, B; Li, Q; Zinna, R; Martin, K; Yu, H; Kirkwood, K L

    2012-10-01

    Aggregatibacter actinomycetemcomitans is a gram-negative facultative capnophile involved in pathogenesis of aggressive forms of periodontal disease. In the present study, we interrogated the ability of A. actinomycetemcomitans to stimulate innate immune signaling and cytokine production and established that A. actinomycetemcomitans causes bone loss in a novel rat calvarial model. In vitro studies indicated that A. actinomycetemcomitans stimulated considerable production of soluble cytokines, tumor necrosis factor-α, interleukin-6 and interleukin-10 in both primary bone marrow-derived macrophages and NR8383 macrophages. Immunoblot analysis indicated that A. actinomycetemcomitans exhibits sustained activation of all major mitogen-activated protein kinase (MAPK) pathways, as well as the negative regulator of MAPK signaling, MAPK phosphatase-1 (MKP-1), for at least 8 h. In a rat calvarial model of inflammatory bone loss, high and low doses of formalin-fixed A. actinomycetemcomitans were microinjected into the supraperiosteal calvarial space for 1-2 weeks. Histological staining and micro-computed tomography of rat calvariae revealed a significant increase of inflammatory and fibroblast infiltrate and increased bone resorption as measured by total lacunar pit formation. From these data, we provide new evidence that fixed whole cell A. actinomycetemcomitans stimulation elicits a pro-inflammatory host response through sustained MAPK signaling, leading to enhanced bone resorption within the rat calvarial bone.

  5. Physical Activity, Body Size, Intentional Weight Loss and Breast Cancer Risk: Fellowship

    DTIC Science & Technology

    1999-10-01

    exercised frequently. More pronounced were results obtained from the model examining the joint effects of early-life physical activity and net lifetime...Number: DAMD17-97-1-7235 TITLE:. Physical Activity , Body Size, Intentional Weight Loss and Breast Cancer Risk: Fellowship PRINCIPAL INVESTIGATOR: Suzanne...SUBTITLE 5. FUNDING NUMBERS Physical Activity , Body Size, Intentional Weight Loss and Breast Cancer: DAMD 17-97-1-7235 Risk: Fellowship 6. AUTHORIS

  6. 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…

  7. A novel fault diagnosis method of PV based-on power loss and I-V characteristics

    NASA Astrophysics Data System (ADS)

    Chen, Y. H.; Liang, R.; Tian, Y.; Wang, F.

    2016-08-01

    The power loss and the changes of internal I-V output characteristics of photovoltaic (PV) module in the typical fault condition were analyzed. We proposed an on-line real time fault diagnosis method for PV module, which takes into account the power loss and the internal I-V characteristics. Taking into account the changes of temperature and irradiation, the running status of the PV module were simulated in real time. Firstly, by comparing the simulated power with the measured power, it could determine whether the abnormal power loss has occurred. Then based on the change of output voltage, it could decide if short-circuit fault has occurred and estimate the number of short circuited cells roughly. Further, the value of fill factor (FF) can be utilized to determine whether aging fault has occurred and to acquire the remaining service life of the module. The results of simulation and experiment show that this method can effectively detect the partial shadow short-circuit fault and aging fault. It proves the feasibility and accuracy of the fault diagnosis method.

  8. Transformer failure and common-mode loss of instrument power at Nine Mile Point Unit 2 on August 13, 1991

    SciTech Connect

    Not Available

    1991-10-01

    On August 13, 1991, at Nine Mile Point Unit 2 nuclear power plant, located near Scriba, New York, on Lake Ontario, the main transformer experienced an internal failure that resulted in degraded voltage which caused the simultaneous loss of five uninterruptible power supplies, which in turn caused the loss of several nonsafety systems, including reactor control rod position indication, some reactor power and water indication, control room annunciators, the plant communications system, the plant process computer, and lighting at some locations. The reactor was subsequently brought to a safe shutdown. Following this event, the US Nuclear Regulatory Commission dispatched an Incident Investigation Team to the site to determine what happened, to identify the probable causes, and to make appropriate findings and conclusions. This report describes the incident, the methodology used by the team in its investigation, and presents and the team's findings and conclusions. 59 figs., 14 tabs.

  9. 26 CFR 1.469-2 - Passive activity loss.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... marketing of the property) is treated for purposes of § 1.469-2T(c)(2) as the use of the interest in a nondealing activity if the marketing of the property is incidental to the nondealing use. Under paragraph (c... section provides rules for determining whether the marketing of the property is incidental to the use...

  10. 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.

  11. Leukotoxic activity of Aggregatibacter actinomycetemcomitans and periodontal attachment loss.

    PubMed

    Höglund Åberg, Carola; Haubek, Dorte; Kwamin, Francis; Johansson, Anders; Claesson, Rolf

    2014-01-01

    Aggregatibacter actinomycetemcomitans is a Gram-negative periodontitis-associated bacterium that expresses a toxin that selectively affects leukocytes. This leukotoxin is encoded by an operon belonging to the core genome of this bacterial species. Variations in the expression of the leukotoxin have been reported, and a well-characterized specific clonal type (JP2) of this bacterium with enhanced leukotoxin expression has been isolated. In particular, the presence of the JP2 genotype significantly increases the risk for the progression of periodontal attachment loss (AL). Based on these findings we hypothesized that variations in the leukotoxicity are linked to disease progression in infected individuals. In the present study, the leukotoxicity of 239 clinical isolates of A. actinomycetemcomitans was analysed with different bioassays, and the genetic peculiarities of the isolates were related to their leukotoxicity based on examination with molecular techniques. The periodontal status of the individuals sampled for the presence of A. actinomycetemcomitans was examined longitudinally, and the importance of the observed variations in leukotoxicity was evaluated in relation to disease progression. Our data show that high leukotoxicity correlates with an enhanced risk for the progression of AL. The JP2 genotype isolates were all highly leukotoxic, while the isolates with an intact leukotoxin promoter (non-JP2 genotypes) showed substantial variation in leukotoxicity. Genetic characterization of the non-JP2 genotype isolates indicated the presence of highly leukotoxic genotypes of serotype b with similarities to the JP2 genotype. Based on these results, we conclude that A. actinomycetemcomitans harbours other highly virulent genotypes besides the previously described JP2 genotype. In addition, the results from the present study further highlight the importance of the leukotoxin as a key virulence factor in aggressive forms of periodontitis.

  12. Antiplasmid activity: loss of bacterial resistance to antibiotics.

    PubMed

    Molnár, J; Földeák, S; Nakamura, M J; Rausch, H; Domonkos, K; Szabó, M

    1992-01-01

    The antiplasmid activity of tricyclic compounds, e.g. phenothiazines, dibenzoazepines, dibenzocykloheptene derivatives and some stereoisomers, was shown on E. coli in vitro. Some ring-substituted phenothiazine and cannabis derivatives had only an antibacterial effect. Promethazine, a selected phenothiazine, cured antibiotic resistance and lactose fermentation of E.coli, tumour inducing ability of Agrobacterium tumefaciens and nodule formation of Rhizobium meliloti. Plasmids of different E.coli strains were eliminated with varying frequency. The antiplasmid activity of the compounds can be due to the increased membrane permeability. Inhibition of DNA gyrase and complex formation with the supercoiled form of plasmid DNA can lead to the cessation of plasmid replication in the bacterial cells. In addition, in vivo plasmid curing was demonstrated at a low frequency.

  13. Optimizing Estimated Loss Reduction for Active Sampling in Rank Learning

    DTIC Science & Technology

    2008-01-01

    ranging from the income level to age and her preference order over a set of products (e.g. movies in Netflix ). The ranking task is to learn a map- ping...learners in RankBoost. However, in both cases, the proposed strategy selects the samples which are estimated to produce a faster convergence from the...steps in Section 5. 2. Related Work A number of strategies have been proposed for active learning in the classification framework. Some of those center

  14. [Plasminogen activator inhibitor type 1 activity in women with unexplained very early recurrent pregnancy loss].

    PubMed

    Ivanov, P; Komsa-Penkova, R; Ivanov, I; Konova, E; Kovacheva, K; Simeonova, M; Tanchev, S

    2010-01-01

    The aim of the study was to assess the independent role of polymorphism 4G/5G (PL 4G/5G)--genotype 4G/4G in plasminogen activator inhibitor type 1 (PAI-1) in the development of very early recurrent pregnancy loss (RPL)--before 10 weeks of gestation of pregnancy. The polymorphism 4G/5G as well as Factor V Leiden (FVL), prothrombin (FII) gene mutation 20210 G > A and polymorphism 677 C > T in methylentetrahydrofolat reductase (MTHFR) gene was investigated in 110 women with recurrent pregnancy loss before 10 weeks of gestation and in 97 healthy women with at least one uncomplicated full-term pregnancy. A significant prevalence of PL 4G/5G in women with RPL was found in comparison to prevalence of the polymorphism in controls (41.8% versus 26.8% respectively in patients and controls, OR: 1.96, 95% CI: 1.05 3.69, p = 0.034). The difference in prevalence of the polymorphism remains still significant after exclusion of patients and control carriers of FVL, FII 202010 G > A and 677 C > T in MTHFR (the prevalence of PL 4G/5G alone was 44.1% and 24% respectively in patients and controls, OR: 2,5, 95% CI: 1,15 5, 45, p = 0.018). The found association of PL 4G/5G in PAI-1 with early recurrent pregnancy loss encourage an extension of the list of inherited thrombophilic factors with this one. This result also could have had an implication for adjustment of further prophylactic low-molecular weight heparin implication in further pregnancy to prevent a poor foetal outcome.

  15. A Multi-Objective Optimization for Performance Improvement of the Z-Source Active Power Filter

    NASA Astrophysics Data System (ADS)

    Hosseini, Seyed Mohsen; Beromi, Yousef Alinejad

    2016-09-01

    The high power dissipation is one of the most important problems of the z-source inverter (ZSI). By using an appropriate optimization scheme, the losses can be significantly reduced without any negative impact on the other characteristics of the inverter. In this paper, a multi-objective optimization is implemented in order to reduce the ZSI total losses as well as to improve the z-source active power filter (APF) performance. The optimization is focused on the four important objectives including power losses of the Z-source APF, the initial cost of the system components, the voltage and current ripples, and the boost factor of the z-source network. For these purposes, the multi-objective genetic algorithm (MOGA) is employed. The numerical and simulation results are presented to evaluate the optimization performance. The results show that a good balance can be achieved between the switching power losses, the voltage-current ripple levels, the component costs and the boost factor using the optimized parameters.

  16. Daily energy expenditure, physical activity, and weight loss in Parkinson's disease patients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patients with Parkinson's disease (PD) commonly exhibit weight loss (WL) which investigators attribute to various factors, including elevated energy expenditure. We tested the hypothesis that daily energy expenditure (DEE) and its components, resting energy expenditure (REE) and physical activity (P...

  17. Geldanamycin Prevents Hemorrhage-Induced ATP Loss by Overexpressing Inducible HSP70 and Activating Pyruvate Dehydrogenase

    DTIC Science & Technology

    2006-03-24

    levels were determined using the ATP Bioluminescence Assay Kit HS II (Roche; Mannheim, Germany). Luminescence was measured with a TD-20/20...Geldanamycin prevents hemorrhage-induced ATP loss by overexpressing inducible HSP70 and activating pyruvate dehydrogenase Juliann G. Kiang,1,2,3...Geldanamycin prevents hemorrhage-induced ATP loss by overexpressing inducible HSP70 and activating pyruvate dehy- drogenase. Am J Physiol Gastrointest

  18. 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.

  19. Analysis and control of unified active power filter

    NASA Astrophysics Data System (ADS)

    Muthu, Subramanian

    1999-11-01

    The combined series and shunt active filters have been proposed to alleviate the power quality problems at the demand-side power systems. However, the conventional approach for the control of the combined active filter systems have resulted in large operating capacity of the shunt active filter because reactive power compensation involves only the shunt active filter. Furthermore, the harmonic mitigation problems are handled mainly by indirect harmonic compensation schemes rather than direct harmonic isolation schemes. This thesis presents the analysis and control of Unified Active Power Filter (UAPF) and proposes a novel concept of load reactive power compensation involving both the series active filter and the shunt active filter. The thesis also applies discrete-time sliding-mode control technique to enhance the performance of the combined active filter system in terms of fast dynamic response and effective solution to harmonic mitigation problems. The thesis also presents simulation and experimental results to provide verification of the proposed UAPF concept. The involvement of series active filter for reactive power compensation is achieved by controlling the phase difference between the load voltage and the utility voltage. The complete steady-state operating characteristics of UAPF are analyzed with the identification of the different operating modes of UAPF and the analysis of active and reactive power handled by the active filter components. The performance of UAPF to meet the stringent power quality standards are realized by applying discrete-time sliding-mode control schemes for the load voltage regulation and the active power factor correction. The control algorithms are developed to track a given load voltage and line current reference signals respectively. The effect of computational delay in DSP implementation is studied extensively and the control law is designed with the consideration for the computational delay. The systematic approach for the

  20. Synergy of inelastic and elastic energy loss. Temperature effects and electronic stopping power dependence

    DOE PAGES

    Zarkadoula, Eva; Xue, Haizhou; Zhang, Yanwen; ...

    2015-06-16

    A combination of an inelastic thermal spike model suitable for insulators and molecular dynamics simulations is used to study the effects of temperature and electronic energy loss on ion track formation, size and morphology in SrTiO3 systems with pre-existing disorder. We find temperature dependence of the ion track size. In addition, we find a threshold in the electronic energy loss for a given pre-existing defect concentration, which indicates a threshold in the synergy between the inelastic and elastic energy loss.

  1. Synergy of inelastic and elastic energy loss. Temperature effects and electronic stopping power dependence

    SciTech Connect

    Zarkadoula, Eva; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-06-16

    A combination of an inelastic thermal spike model suitable for insulators and molecular dynamics simulations is used to study the effects of temperature and electronic energy loss on ion track formation, size and morphology in SrTiO3 systems with pre-existing disorder. We find temperature dependence of the ion track size. In addition, we find a threshold in the electronic energy loss for a given pre-existing defect concentration, which indicates a threshold in the synergy between the inelastic and elastic energy loss.

  2. A new field-sensing method to measure the power loss of electrical steel sheet under two-dimensional measuring conditions

    SciTech Connect

    Birkfeld, M.; Hempel, K.A.

    1996-09-01

    A sensor system is proposed that allows a fast and integral measurement of the power loss in the sample volume independent of the geometry and positioning of the sample in the setup. The power loss is determined under various two-dimensional measuring conditions. The obtained values are compared to those investigated with standard methods.

  3. Essential roles of mitochondrial depolarization in neuron loss through microglial activation and attraction toward neurons.

    PubMed

    Nam, Min-Kyung; Shin, Hyun-Ah; Han, Ji-Hye; Park, Dae-Wook; Rhim, Hyangshuk

    2013-04-10

    As life spans increased, neurodegenerative disorders that affect aging populations have also increased. Progressive neuronal loss in specific brain regions is the most common cause of neurodegenerative disease; however, key determinants mediating neuron loss are not fully understood. Using a model of mitochondrial membrane potential (ΔΨm) loss, we found only 25% cell loss in SH-SY5Y (SH) neuronal mono-cultures, but interestingly, 85% neuronal loss occurred when neurons were co-cultured with BV2 microglia. SH neurons overexpressing uncoupling protein 2 exhibited an increase in neuron-microglia interactions, which represent an early step in microglial phagocytosis of neurons. This result indicates that ΔΨm loss in SH neurons is an important contributor to recruitment of BV2 microglia. Notably, we show that ΔΨm loss in BV2 microglia plays a crucial role in microglial activation and phagocytosis of damaged SH neurons. Thus, our study demonstrates that ΔΨm loss in both neurons and microglia is a critical determinant of neuron loss. These findings also offer new insights into neuroimmunological and bioenergetical aspects of neurodegenerative disease.

  4. Fhit loss in lung preneoplasia: relation to DNA damage response checkpoint activation

    PubMed Central

    Cirombella, Roberto; Montrone, Giuseppe; Stoppacciaro, Antonella; Giglio, Simona; Volinia, Stefano; Graziano, Paolo; Huebner, Kay; Vecchione, Andrea

    2009-01-01

    Loss of heterozygosity at the FHIT locus is coincident with activation of DNA damage response checkpoint proteins; thus damage at fragile loci may trigger checkpoint activation. We examined preneoplastic lesions adjacent to non-small cell lung carcinomas for alterations to expression of Fhit and activated checkpoint proteins. Expression scores were analyzed for pair-wise associations and correlations among proteins and type of lesion. Hyperplastic and dysplastic lesions were positive for nuclear H2AX expression; 12/20 dysplastic lesions were negative for Fhit expression. Fhit positive lesions showed expression of most checkpoint proteins examined, while Fhit negative lesions showed absence of expression of Chk1 and phosphoChk1. The results show that loss of expression of Fhit is significantly directly correlated with absence of activated Chk1 in dysplasia, and suggest a connection between loss of Fhit and modulation of checkpoint activity. PMID:19931269

  5. Minimization of the energy loss of nuclear power plants in case of partial in-core monitoring system failure

    NASA Astrophysics Data System (ADS)

    Zagrebaev, A. M.; Ramazanov, R. N.; Lunegova, E. A.

    2017-01-01

    In this paper we consider the optimization problem minimize of the energy loss of nuclear power plants in case of partial in-core monitoring system failure. It is possible to continuation of reactor operation at reduced power or total replacement of the channel neutron measurements, requiring shutdown of the reactor and the stock of detectors. This article examines the reconstruction of the energy release in the core of a nuclear reactor on the basis of the indications of height sensors. The missing measurement information can be reconstructed by mathematical methods, and replacement of the failed sensors can be avoided. It is suggested that a set of ‘natural’ functions determined by means of statistical estimates obtained from archival data be constructed. The procedure proposed makes it possible to reconstruct the field even with a significant loss of measurement information. Improving the accuracy of the restoration of the neutron flux density in partial loss of measurement information to minimize the stock of necessary components and the associated losses.

  6. 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.

  7. A new combined method in active filter design for power quality improvement in power systems.

    PubMed

    Hooshmand, Rahmat Allah; Torabian Esfahani, Mahdi

    2011-04-01

    The voltage & current harmonics produced by nonlinear loads in power systems cause a reduction in power quality. In order to improve the power quality, active power filters (APFs) can be used. In this paper, a new control system for designing active filters despite nonlinear loads of electric arc furnaces (EAFs) is presented. The system is composed of three main parts: computation of reference currents, regulation of DC capacitor voltage, and production of firing pulses. In the first part, the active filter control system is presented based on the combination of the synchronous detection method and instantaneous power theory. In the second part, the DC capacitor voltage regulator is applied, producing a reference current and a proper voltage regulator is developed. For the third part of the control system, we use a PI controller to provide some conditions that follow the reference current in a complete cycle, and generate firing pulses by the hysteresis method. The proposed control system not only reduces the voltage and current harmonics in power systems but can also improve the power quality indices. The above design was implemented in the EAF system of the Mobarakeh steel complex (Isfahan, Iran). The simulation results show the effectiveness of the APFs in improving the power quality indices.

  8. 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.

  9. Dielectric spectroscopy measurements on very low loss cross-linked polyethylene power cables

    NASA Astrophysics Data System (ADS)

    Liu, Tong; Fothergill, John; Dodd, Steve; Nilsson, Ulf

    2009-08-01

    The principles of dielectric spectroscopy are reviewed and the techniques in both time and frequency domains are explored in search of appropriate methods for measurement on low loss XLPE cables. By combining the techniques of frequency response analyzer, transformer ratio bridge and discharging current measurements, some preliminary tests results on homopolymer XLPE model cables have been presented and analyzed, in a wide frequency range of 10-4Hz~2×104Hz. Dielectric loss mechanisms of XLPE cables are discussed based on the measurement results.

  10. 1.38 MW peak power dual-loss modulated sub-nanosecond green laser with EO and graphene

    NASA Astrophysics Data System (ADS)

    Tang, Wenjing; Zhao, Jia; Yang, Kejian; Zhao, Shengzhi; Li, Guiqiu; Li, Dechun; Li, Tao; Qiao, Wenchao

    2016-12-01

    By simultaneously employing electro-optic (EO) modulator and Graphene saturable absorber (SA) in a dual-loss-modulated Q-switched and mode-locking (QML) Nd:Lu0.15Y0.85VO4/KTP green laser, the sub-nanosecond single mode-locking green laser is demonstrated with high peak power, low repetition rate and high stability. The monolayer and 3-layer graphene sheets grown by chemical vapor deposition (CVD) method were used as SAs in the experiment. When the pump power reached 10.72 W, the maximum peak power obtained from the doubly QML laser with EO and monolayer graphene-SA was 1.38 MW, corresponding to a pulse duration of 480 ps. The shortest pulse width of 340 ps was obtained with a 3-layer graphene-SA.

  11. A study using a Monte Carlo method of the optimal configuration of a distribution network in terms of power loss sensing.

    PubMed

    Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

    2011-01-01

    Recently there have been many studies of power systems with a focus on "New and Renewable Energy" as part of "New Growth Engine Industry" promoted by the Korean government. "New And Renewable Energy"-especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels-is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI's IntelliGrid research program. The European Union (EU), which represents Europe's Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal design, which considers

  12. Fenfluramine treatment in female rats accelerates the weight loss associated with activity-based anorexia.

    PubMed

    Atchley, Deann P D; Eckel, Lisa A

    2005-02-01

    Serotonin plays an important role in controlling food intake and regulating body weight. Thus, altered serotonergic function may be involved in the etiology of anorexia nervosa. To investigate this hypothesis, we examined whether activation of the serotonin system increases the severity of activity-based anorexia, an animal model of anorexia nervosa in which food-restricted rats are housed with access to running wheels. This paradigm promotes symptoms of anorexia nervosa, including hypophagia, hyperactivity, and weight loss. Food-restricted rats received injections of a serotonin agonist, fenfluramine, or saline 1.5 h prior to their daily 2-h period of food access. A third saline-injected group was pair-fed to the fenfluramine group. Drug treatment and food restriction were terminated following a 25% weight loss. During food restriction, each group developed symptoms of activity-based anorexia. Although similar reductions in food intake were observed in fenfluramine-treated and pair-fed rats, only fenfluramine-treated rats displayed an accelerated rate of weight loss, relative to saline-treated rats. Thus, some other nonanorexic aspect of fenfluramine, perhaps its influence on metabolism, must underlie the accelerated rate of weight loss in this group. Our results suggest that increased activation of the serotonin system exacerbates the weight loss associated with activity-based anorexia.

  13. Enhanced magnetic domain relaxation frequency and low power losses in Zn2+ substituted manganese ferrites potential for high frequency applications

    NASA Astrophysics Data System (ADS)

    Praveena, K.; Chen, Hsiao-Wen; Liu, Hsiang-Lin; Sadhana, K.; Murthy, S. R.

    2016-12-01

    Nowadays electronic industries prerequisites magnetic materials, i.e., iron rich materials and their magnetic alloys. However, with the advent of high frequency applications, the standard techniques of reducing eddy current losses, using iron cores, were no longer efficient or cost effective. Current market trends of the switched mode power supplies industries required even low energy losses in power conversion with maintenance of adequate initial permeability. From the above point of view, in the present study we aimed at the production of Manganese-Zinc ferrites prepared via solution combustion method using mixture of fuels and achieved low loss, high saturation magnetization, high permeability, and high magnetic domain relaxation frequency. The as-synthesized Zn2+ substituted MnFe2O4 were characterized by X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The fractions of Mn2+, Zn2+ and Fe2+ cations occupying tetrahedral sites along with Fe occupying octahedral sites within the unit cell of all ferrite samples were estimated by Raman scattering spectroscopy. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (fr) was increased with the increase in grain size. The real and imaginary part of permeability (μ‧ and μ″) increased with frequency and showed a maximum above 100 MHz. This can be explained on the basis of spin rotation and domain wall motion. The saturation magnetization (Ms), remnant magnetization (Mr) and magneton number (μB) decreased gradually with increasing Zn2+ concentration. The decrease in the saturation magnetization was discussed with Yafet-Kittel (Y-K) model. The Zn2+ concentration increases the relative number of ferric ions on the A sites, reduces the A-B interactions. The frequency dependent total power losses decreased as the zinc concentration increased. At 1 MHz, the total power loss (Pt) changed from 358 mW/cm3 for x=0-165 mW/cm3

  14. Modeling turbine wakes and power losses within the Horns Rev offshore wind farm using large-eddy simulation

    NASA Astrophysics Data System (ADS)

    Wu, Yu-Ting; Porte-Agel, Fernando

    2013-04-01

    A recently-developed large-eddy simulations (LES) framework is implemented to predict multiple wake flows and the associated power losses within the Horns Rev offshore wind farm under near-neutral stability conditions. A tuning-free Lagrangian scale-dependent dynamic subgrid-scale (SGS) model is used for the parametrization of the SGS stresses. The turbine-generated power outputs and the turbine-induced forces (e.g., thrust, lift, drag) are parameterized using two models: (a) the traditional actuator-disk model without rotation (ADM-NR), which uses the 1D momentum theory to relate the power output and the thrust force with a representative velocity over the rotor (e.g., the disk-averaged velocity); and (b) the actuator-disk model with rotation (ADM-R), which adopts blade element theory to calculate the lift and drag forces (that produce thrust, rotor shaft torque, and power) based on the local blade and flow characteristics. In general, the predicted power outputs obtained using the ADM-R are in good agreement with observed power data from the Horns Rev wind farm. The ADM-NR tends to underestimate the power output. A similar under-prediction is obtained using industry-standard wind-farm models such as the Wind Atlas Analysis and Application Program (WAsP). Simulations using different inflow conditions show that the mean wind direction has a strong effect on the spatial distributions of the time-averaged velocity and the turbulence intensity within the farm. These, in turn, affect the power output and the fatigue loads on the turbines. When the prevailing wind direction is parallel to the turbine rows (i.e., a full wake condition), the velocity deficit and the power losses are largest, and the turbulence intensity levels are highest and have a symmetric pattern (dual-peak at hub height) on both sides of the turbine wakes. A detailed analysis of the turbulence kinetic energy budget in the full wake condition shows an important effect of the increased turbulence level

  15. [The active middle ear implant for the rehabilitation of sensorineural, mixed and conductive hearing losses].

    PubMed

    Sprinzl, G M; Wolf-Magele, A; Schnabl, J; Koci, V

    2011-09-01

    Active middle ear implants, such as the Vibrant Soundbridge, are used as an important part in the rehabilitation of sensorineural, conductive hearing, or mixed hearing loss. The attachment of the Vibrant Soundbridge at the round window and the usage of the Vibroplasty couplers strongly expanded the application of the Vibrant Soundbridge.The Vibrant Soundbridge is developed for patients who have an intolerance to hearing aids and a moderate to profound sensorineural hearing loss. The VSB also provides an optimal solution for patients with failed middle ear reconstructions or patients with atresia. To capture the improvement with the VSB Implant with different hearing losses a literature analysis was conducted. The functional gain was analyzed for 107 patients with conductive hearing loss and for 214 patients with sensorineural hearing loss out of 14 studies.Patients with conductive and mixed hearing loss resulted in a functional gain from 30 to 58 dB with the VSB. Patients with a pure sensorineural hearing loss showed a functional gain of 23-30 dB. The VSB bone conduction threshold shift was analyzed for all studies conducted in the years between 2000 and 2009. In 11 of the 16 studies there was no significant (p=0.05) change found. In 5 studies, the pre- to post-surgical bone conduction threshold shift was less than 10 dB. None of these studies measured a threshold shift of more than 10 dB.The flexible attachment at either the long process of the incus with sensorineural hearing loss, with an conductive hearing loss at the round window or the use of Vibroplasty couplers at the oval window, head of the stapes or round window makes the VSB an extremely versatile instrument. If patients can't wear conventional hearing aids, had failed middle ear reconstructions or atresia the VSB presents, due to the significant hearing improvement in any type of hearing loss, an ideal solution.

  16. Loss of Frataxin activates the iron/sphingolipid/PDK1/Mef2 pathway in mammals.

    PubMed

    Chen, Kuchuan; Ho, Tammy Szu-Yu; Lin, Guang; Tan, Kai Li; Rasband, Matthew N; Bellen, Hugo J

    2016-11-30

    Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by mutations in Frataxin (FXN). Loss of FXN causes impaired mitochondrial function and iron homeostasis. An elevated production of reactive oxygen species (ROS) was previously proposed to contribute to the pathogenesis of FRDA. We recently showed that loss of frataxin homolog (fh), a Drosophila homolog of FXN, causes a ROS independent neurodegeneration in flies (Chen et al., 2016). In fh mutants, iron accumulation in the nervous system enhances the synthesis of sphingolipids, which in turn activates 3-phosphoinositide dependent protein kinase-1 (Pdk1) and myocyte enhancer factor-2 (Mef2) to trigger neurodegeneration of adult photoreceptors. Here, we show that loss of Fxn in the nervous system in mice also activates an iron/sphingolipid/PDK1/Mef2 pathway, indicating that the mechanism is evolutionarily conserved. Furthermore, sphingolipid levels and PDK1 activity are also increased in hearts of FRDA patients, suggesting that a similar pathway is affected in FRDA.

  17. Physical Activity, Body Size, Intentional Weight Loss and Breast Cancer Risk: Fellowship

    DTIC Science & Technology

    1998-10-01

    GRANT NUMBER DAMD17-97-1-7235 TITLE: Physical Activity , Body Size, Intentional Weight Loss and Breast Cancer Risk: Fellowship PRINCIPAL INVESTIGATOR...2. REPORT DATE 3. REPORT TYPE AND DATES COVERED October 1998 Annual (1 Oct 97 - 30 Sep 98) 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Physical Activity ... physical activity and breast cancer risk was evaluated using extant data from a case-control study of breast cancer. Cases (n=6888) were identified

  18. Power Subsystem for Extravehicular Activities for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Manzo, Michelle

    2005-01-01

    The NASA Glenn Research Center has the responsibility to develop the next generation space suit power subsystem to support the Vision for Space Exploration. Various technology challenges exist in achieving extended duration missions as envisioned for future lunar and Mars mission scenarios. This paper presents an overview of ongoing development efforts undertaken at the Glenn Research Center in support of power subsystem development for future extravehicular activity systems.

  19. 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.

  20. Analysis of the working process and mechanical losses in a Stirling engine for a solar power unit

    SciTech Connect

    Makhkamov, K.K.; Ingham, D.B.

    1999-05-01

    In this paper a second level mathematical model for the computational simulation of the working process of a 1-kW Stirling engine has been used and the results obtained are presented. The internal circuit of the engine in the calculation scheme was divided into five chambers, namely, the expansion space, heater, regenerator, cooler and the compression space, and the governing system of ordinary differential equations for the energy and mass conservation were solved in each chamber by Euler`s method. In addition, mechanical losses in the construction of the engine have been determined and the computational results show that the mechanical losses for this particular design of the Stirling engine may be up to 50% of the indicated power of the engine.

  1. Recovery of inter-row shading losses using differential power-processing submodule DC–DC converters

    DOE PAGES

    Doubleday, Kate; Choi, Beomseok; Maksimovic, Dragan; ...

    2016-06-17

    Large commercial photovoltaic (PV) systems can experience regular and predictable energy loss due to both inter-row shading and reduced diffuse irradiance in tightly spaced arrays. This article investigates the advantages of replacing bypass diodes with submodule-integrated DC-DC converters (subMICs) to mitigate these losses. Yearly simulations of commercial-scale PV systems were conducted considering a range of row-to-row pitches. In the limit case of array spacing (unity ground coverage), subMICs can confer a 7% increase in annual energy output and peak energy density (kW h/m2). Simulation results are based on efficiency assumptions experimentally confirmed by prototype submodule differential power-processing converters.

  2. A compact and low-loss 1×8 optical power splitter using silica-based PLC on quartz substrate

    NASA Astrophysics Data System (ADS)

    Wang, Liangliang; An, Junming; Wu, Yuanda; Zhang, Jiashun; Wang, Yue; Li, Jianguang; Wang, Hongjie; Zhang, Xiaoguang; Pan, Pan; Zhang, Liyao; Dai, Hongqing; Liu, Ruidan; Zhong, Fei; Zha, Qiang; Hu, Xiongwei; Zhao, Degang

    2014-02-01

    In this paper, a compact, low-loss and good-uniformity 1×8 optical power splitter with new Y-branch structure is demonstrated using silica-based PLC technology on quartz substrate. Broadening waveguide and transition waveguide of the new Y-branch are optimized by using 3D BPM. The measurement results show that the insertion loss (IL) and the uniformity (UNIF) of the splitters are less than 9.5 dB and 0.35 dB, respectively, in the wavelength range from 1.26 μm to 1.65 μm, and the total product ratio of premium grade in a whole 6 in. wafer is more than 95%. The results mean that our technology completely satisfies the need of mass manufacture.

  3. Recovery of inter-row shading losses using differential power-processing submodule DC–DC converters

    SciTech Connect

    Doubleday, Kate; Choi, Beomseok; Maksimovic, Dragan; Deline, Chris; Olalla, Carlos

    2016-06-17

    Large commercial photovoltaic (PV) systems can experience regular and predictable energy loss due to both inter-row shading and reduced diffuse irradiance in tightly spaced arrays. This article investigates the advantages of replacing bypass diodes with submodule-integrated DC-DC converters (subMICs) to mitigate these losses. Yearly simulations of commercial-scale PV systems were conducted considering a range of row-to-row pitches. In the limit case of array spacing (unity ground coverage), subMICs can confer a 7% increase in annual energy output and peak energy density (kW h/m2). Simulation results are based on efficiency assumptions experimentally confirmed by prototype submodule differential power-processing converters.

  4. Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss

    NASA Astrophysics Data System (ADS)

    Zhang, Xiangming; Wang, Ping; Wang, Ya

    2015-11-01

    Bone density loss in astronauts on long-term space missions is a chief medical concern. Microgravity in space is the major cause of bone density loss (osteopenia), and it is believed that high linear energy transfer (LET) radiation in space exacerbates microgravity-induced bone density loss; however, the mechanism remains unclear. It is known that acidic serine- and aspartate-rich motif (ASARM) as a small peptide released by matrix extracellular phosphoglycoprotein (MEPE) promotes osteopenia. We previously discovered that MEPE interacted with checkpoint kinase 1 (CHK1) to protect CHK1 from ionizing radiation promoted degradation. In this study, we addressed whether the CHK1-MEPE pathway activated by radiation contributes to the effects of microgravity on bone density loss. We examined the CHK1, MEPE and secreted MEPE/ASARM levels in irradiated (1 Gy of X-ray) and rotated cultured human osteoblast cells. The results showed that radiation activated CHK1, decreased the levels of CHK1 and MEPE in human osteoblast cells and increased the release of MEPE/ASARM. These results suggest that the radiation-activated CHK1/MEPE pathway exacerbates the effects of microgravity on bone density loss, which may provide a novel targeting factor/pathway for a future countermeasure design that could contribute to reducing osteopenia in astronauts.

  5. Radiation activated CHK1/MEPE pathway may contribute to microgravity-induced bone density loss

    PubMed Central

    Zhang, Xiangming; Wang, Ping; Wang, Ya

    2016-01-01

    Bone density loss in astronauts on long-term space missions is a chief medical concern. Microgravity in space is the major cause of bone density loss (osteopenia), and it is believed that high linear energy transfer (LET) radiation in space exacerbates microgravity-induced bone density loss; however, the mechanism remains unclear. It is known that acidic serine- and aspartate-rich motif (ASARM) as a small peptide released by matrix extracellular phosphoglycoprotein (MEPE) promotes osteopenia. We previously discovered that MEPE interacted with checkpoint kinase 1 (CHK1) to protect CHK1 from ionizing radiation promoted degradation. In this study, we addressed whether the CHK1-MEPE pathway activated by radiation contributes to the effects of microgravity on bone density loss. We examined the CHK1, MEPE and secreted MEPE/ASARM levels in irradiated (1 Gy of X-ray) and rotated cultured human osteoblast cells. The results showed that radiation activated CHK1, decreased the levels of CHK1 and MEPE in human osteoblast cells and increased the release of MEPE/ASARM. These results suggest that the radiation-activated CHK1/MEPE pathway exacerbates the effects of microgravity on bone density loss, which may provide a novel targeting factor/pathway for a future countermeasure design that could contribute to reducing osteopenia in astronauts. PMID:26553637

  6. The role of physical activity in producing and maintaining weight loss

    PubMed Central

    Catenacci, Victoria A; Wyatt, Holly R

    2015-01-01

    Summary The majority of randomized, controlled trials (RCTs) show only modest weight loss with exercise intervention alone, and slight increases in weight loss when exercise intervention is added to dietary restriction. In most RCTs, the energy deficit produced by the prescribed exercise is far smaller than that usually produced by dietary restriction. In prospective studies that prescribed high levels of exercise, enrolled individuals achieved substantially greater weight loss—comparable to that obtained after similar energy deficits were produced by caloric restriction. High levels of exercise might, however, be difficult for overweight or obese adults to achieve and sustain. RCTs examining exercise and its effect on weight-loss maintenance demonstrated mixed results; however, weight maintenance interventions were usually of limited duration and long-term adherence to exercise was problematic. Epidemiologic, cross-sectional, and prospective correlation studies suggest an essential role for physical activity in weight-loss maintenance, and post hoc analysis of prospective trials shows a clear dose–response relationship between physical activity and weight maintenance. This article reviews the role of physical activity in producing and maintaining weight loss. We focus on prospective, RCTs lasting at least 4 months; however, other prospective trials, meta-analyses and large systematic reviews are included. Limitations in the current body of literature are discussed. PMID:17581621

  7. Loss of factor VIII activity during storage in PVC containers due to adsorption.

    PubMed

    McLeod, A G; Walker, I R; Zheng, S; Hayward, C P

    2000-03-01

    Recombinant factor VIII concentrates are stable when administered in a reconstituted form according to the manufacturer's specifications, and undiluted via infusion with syringe mini-pumps. However many Haemophilia centres administer recombinant factor VIII further diluted in intravenous fluids for greater ease of administration. To investigate the stability of recombinant factor VIII during administration as a diluted infusion, reconstituted factor VIII was stored in polyvinylchloride (PVC) mini-bags undiluted (146 IU mL-1) and at factor VIII concentrations of 10 IU mL-1 and 2 IU mL-1. After 48 h of storage at room temperature in PVC mini-bags, the recoveries of factor VIII activity were 41.9% of the initial activity for the undiluted (146 IU mL-1) product and 43.7% of the initial activity for factor VIII diluted to 10 IU mL-1. For factor VIII diluted to 2 IU mL-1, the amount of factor VIII activity remaining at 48 h was only 1.8% of the initial activity. In contrast, 100% of factor VIII activity was recovered after 48 h when undiluted reconstituted product (146 IU mL-1) was stored in a syringe. To investigate the mechanism of factor VIII activity loss during storage, factor VIII samples collected after 0, 3 and 48 h of storage were analysed by immunoblotting with factor VIII antibodies. No evidence of factor VIII proteolytic degradation during storage was found, however, large amounts of factor VIII antigen were recovered from the empty PVC mini-bags following elution with denaturing detergent. We conclude that clinically significant losses of factor VIII activity occur during storage in PVC mini-bags and that the loss of activity is most likely due to protein adsorption onto the plastic surface. This loss of factor VIII activity during storage in PVC containers may substantially affect the safety and potential cost savings of administering recombinant factor VIII by continuous infusion.

  8. Associations among Endocrine, Inflammatory, and Bone Markers, Body Composition and Physical Activity to Weight Loss Induced Bone Loss

    PubMed Central

    Labouesse, Marie A.; Gertz, Erik R.; Piccolo, Brian D.; Souza, Elaine C.; Schuster, Gertrud U.; Witbracht, Megan G.; Woodhouse, Leslie R.; Adams, Sean H.; Keim, Nancy L.; Van Loan, Marta D.

    2015-01-01

    INTRODUCTION Weight loss reduces co-morbidities of obesity, but decreases bone mass. PURPOSE Our aims were to 1) determine if adequate dairy intake attenuates weight loss-induced bone loss; 2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; 3) model the contribution of these variables to post weight-loss BMD and BMC METHODS Overweight/obese women (BMI: 28–37 kg/m2) were enrolled in an energy reduced (−500 kcal/d; −2092 kJ/d) diet with adequate dairy (AD: 3–4 servings/d; n=25, 32.2 ± 8.8y) or low dairy (LD: ≤ 1 serving/d; n=26, 31.7 ± 8.4 y). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. RESULTS Following weight loss, AD intake resulted in significantly greater (p= 0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post- body fat were negatively associated with hip and lumbar spine BMC (r= −0.28, p=0.04 to −0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = −0.29 (p=0.04) to r = −0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss Factors. Pre-weight loss Factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss Factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the Factors contributed to the variance in lumbar spine BMD. CONCLUSION AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD

  9. Giant third-order nonlinearity from low-loss electrochemical graphene oxide film with a high power stability

    NASA Astrophysics Data System (ADS)

    Ren, Jun; Zheng, Xiaorui; Tian, Zhiming; Li, Dan; Wang, Pu; Jia, Baohua

    2016-11-01

    Giant third-order nonlinear absorption and refraction of electrochemical graphene oxide (EGO) film were investigated in the femtosecond regime using the single beam Z-scan technique. The excellent chemical stability of the EGO film under high-power illumination up to 400 mJ/cm2 is demonstrated, which can be attributed to the low oxidation degree revealed by the optical and Raman spectroscopies. High and broadband linear transmission over 70% has been observed from the visible to the infrared range. The low-loss EGO film with giant third-order nonlinearity, excellent chemical stability, large-scale preparation and flexible integration has a great potential for high-power nonlinear optical applications.

  10. "Kicking Up Some Dust": An Experimental Investigation Relating Lunar Dust Erosive Wear to Solar Power Loss

    NASA Technical Reports Server (NTRS)

    Mpagazehe, Jeremiah N.; Street, Kenneth W., Jr.; Delgado, Irebert R.; Higgs, C. Fred, III

    2013-01-01

    The exhaust from retrograde rockets fired by spacecraft landing on the Moon can accelerate lunar dust particles to high velocities. Information obtained from NASA's Apollo 12 mission confirmed that these high-speed dust particles can erode nearby structures. This erosive wear damage can affect the performance of optical components such as solar concentrators. Solar concentrators are objects which collect sunlight over large areas and focus the light into smaller areas for purposes such as heating and energy production. In this work, laboratory-scale solar concentrators were constructed and subjected to erosive wear by the JSC-1AF lunar dust simulant. The concentrators were focused on a photovoltaic cell and the degradation in electrical power due to the erosive wear was measured. It was observed that even moderate exposure to erosive wear from lunar dust simulant resulted in a 40 percent reduction in power production from the solar concentrators.

  11. Making Physical Activity Accessible to Older Adults with Memory Loss: A Feasibility Study

    ERIC Educational Resources Information Center

    Logsdon, Rebecca G.; McCurry, Susan M.; Pike, Kenneth C.; Teri, Linda

    2009-01-01

    Purpose: For individuals with mild cognitive impairment (MCI), memory loss may prevent successful engagement in exercise, a key factor in preventing additional disability. The Resources and Activities for Life Long Independence (RALLI) program uses behavioral principles to make exercise more accessible for these individuals. Exercises are broken…

  12. 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.

  13. Measurement of higher-order mode losses in SPEAR II by shift in synchrotron phase and increase in net cavity power

    SciTech Connect

    Not Available

    1988-01-01

    It has been estimated that the loss to higher-order cavity modes in SPEAR II will be 135 keV per cavity at 100 mA for a 10-cm bunch (sigma/sub z/ = 5 cm). This corresponds to a loss of 10 MeV for a 50-m PEP structure. The power lost to higher modes in each SPEAR II cavity at 100 mA would be 13.5 kW. A loss of this order can be measured by calorimetry. This loss is also large enough to cause a significant increase in the net rf power input into the cavities over the power input with no higher-mode excitation. In addition, the higher-mode loss can also produce a measurable shift in the synchronous phase angle. Numbers for these effects are computed in this paper.

  14. Introduction of a current waveform, waveshaping technique to limit conduction loss in high-frequency dc-dc converters suitable for space power

    NASA Astrophysics Data System (ADS)

    Miller, Douglas P.

    1990-06-01

    Space power supply manufacturers have tried to increase power density and construct smaller, highly efficient power supplies by increasing switching frequency. Incorporation of a power MOSFET as a switching element alleviates switching loss. However, values of R sub DS(on) (drain-to-source resistance in the on-state) for MOSFET's are of such magnitude to produce greater on-state losses than an equivalent BJT operated in saturation. This research serves to introduce a design concept, pertinent to low-voltage relatively-high-current applications, that minimizes the peak current through the switching element in order to reduce average power loss. Basic waveforms produced by different PWM and resonant mode topologies were examined. Theoretical analysis reveals that a ramp-sine current waveform could cut conduction power loss by at least 18 percent over a conventional Buck switching converter. A 14V, 14W combination quasi-resonant Buck/ZCS, Quasi-Resonant Buck dc-dc converter with an unregulated input voltage of 28 V was built for simplicity to demonstrate one particular waveshaping technique. This converter represents a useful example of an actual circuit which is capable of producing the desired ramp-sine switch-current waveform. Final results confirm improvement in conduction loss enhancing existing power MOSFET technology for use in dc-dc power conversion.

  15. Design of power-plant installations pressure-loss characteristics of duct components

    NASA Technical Reports Server (NTRS)

    Henry, John R

    1944-01-01

    A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging bends; vaned bends; diffusers; branch ducts; internal inlets; and an angular placement of heat exchangers. Examples are included to illustrate methods of applying these data in analyzing duct systems. (author)

  16. Induced magnetization and power loss for a periodically driven system of ferromagnetic nanoparticles with randomly oriented easy axes

    NASA Astrophysics Data System (ADS)

    Denisov, S. I.; Lyutyy, T. V.; Pedchenko, B. O.; Hryshko, O. M.

    2016-07-01

    We study the effect of an elliptically polarized magnetic field on a system of noninteracting, single-domain ferromagnetic nanoparticles characterized by a uniform distribution of easy axis directions. Our main goal is to determine the average magnetization of this system and the power loss in it. In order to calculate these quantities analytically, we develop a general perturbation theory for the Landau-Lifshitz-Gilbert (LLG) equation and find its steady-state solution for small magnetic field amplitudes. On this basis, we derive the second-order expressions for the average magnetization and power loss, investigate their dependence on the magnetic field frequency, and analyze the role of subharmonic resonances resulting from the nonlinear nature of the LLG equation. For arbitrary amplitudes, the frequency dependence of these quantities is obtained from the numerical solution of this equation. The impact of transitions between different regimes of regular and chaotic dynamics of magnetization, which can be induced in nanoparticles by changing the magnetic field frequency, is examined in detail.

  17. A computerized on-line power loss testing system for the steel industry, based on the RCP compensation technique

    SciTech Connect

    Khanlou, A.; Moses, A.J.; Meydan, T.; Beckley, P.

    1995-11-01

    The design and development of a novel, non-enwrapping power loss testing system which can be used to grade electrical steels directly on the production line has been described. The developed system incorporates the use of Rogowski Chattock Potentiometer (RCP) coils. These coils function as a zero field potential indicator between two defined points along the measuring region of a single specimen of electrical steel, hence making the surface magnetic field proportional to the magnetizing current. This enables the field component necessary for power loss measurement to be obtained from the magnetizing current which is more convenient in an on-line situation. The developed system has been fully computerized and it is shown that under static laboratory conditions the system correlates well with a deviation of only 2.5% from values obtained using the current standard, the Epstein Frame. The effect of strip motion on the measurements has also been investigated and discussed to understand how the system will perform on the actual production line.

  18. Evaluation of Pulsed Power Architectures for Active Detection

    DTIC Science & Technology

    2013-06-01

    strongest responses of the fissile material, prompt and delayed neutrons and delayed gammas . Based on a notional detection scenario, the...EVALUATION OF PULSED POWER ARCHITECTURES FOR ACTIVE DETECTION* I.D. Smith, P.A. Corcoran, R. Altes, D. Morton, R. Stevens and B. Whitney L-3...Abstract: Intense pulsed active detection (IPAD, [1]; also see presentations at this conference by B.V. Weber, et al., D.P Murphy et al

  19. 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.

  20. L-H power threshold scaling with magnetic geometry on NSTX and the role of ion orbit loss

    NASA Astrophysics Data System (ADS)

    Battaglia, D. J.; Chang, C.-S.; Kaye, S. M.; Ku, S.; Maingi, R.; NSTX Team

    2011-10-01

    The L-H power threshold (PLH) on the National Spherical Torus Experiment varies with X-point radius (RX) , plasma current (Ip) , the direction of the ion grad-B drift and the amount of lithium evaporated on the divertor surfaces. The edge Te and Ti (where Te ~ Ti) just prior to the time of the L-H transition vary with the magnetic geometry, but are fairly independent of the neutral fueling rate and lithium conditioning. These observations are consistent with the X-transport theory, which describes the mean edge radial electric field (Er) profile required to prevent non-ambipolar ion loss in a diverted plasma. A guiding-center orbit calculation in the absence of electric fields, collisions and flows provides insight into the dependence of the ion loss, and thus Er, on the magnetic geometry and edge Ti. For example, the number of ion loss orbits remains constant as RX is reduced from 0.64m to 0.47m only if the edge Ti increases by 60%. This is in agreement with self-consistent calculations of Er using the neoclassical XGC0 code and experiments that measured edge Te and Ti to be 40 - 60% larger. Similar agreement is also observed between guiding-center calculations, XGC0 results and the measured PLH versus Ip and ion grad-B direction. Supported by US DOE contracts DE-AC02-09CH11466 and DE-AC05-00OR22725.

  1. Simulation of the ohmic loss in photovoltaic laser-power converters for wavelengths of 809 and 1064 nm

    SciTech Connect

    Emelyanov, V. M. Mintairov, S. A.; Sorokina, S. V.; Khvostikov, V. P.; Shvarts, M. Z.

    2016-01-15

    The method of mathematical simulation is used to examine the influence exerted by the characteristics of the epitaxial structure and contact grid of photovoltaic laser-power converters on their ohmic loss. The maximum attainable photoconverter efficiency at a Gaussian distribution of the laser-beam intensity on the surface of a photovoltaic converter and at dark-current densities of p–n junctions typical of structures grown by the metal-organic vapor-phase epitaxy (MOVPE) technique are determined. An approach to finding the optimal parameters of GaAs and In{sub 0.24}Ga{sub 0.76}As/GaAs photovoltaic converters in relation to the optical power being converted is suggested, and the structural parameters for incident-power values of 5, 20, and 50 W at wavelengths of 809 and 1064 nm are determined. It is found that, at laser-light intensities of up to 5 W, >60% efficiency can be achieved in laser-light conversion at a wavelength of 809 nm and >55% efficiency, at a wavelength of 1064 nm.

  2. RSS-Based Method for Sensor Localization with Unknown Transmit Power and Uncertainty in Path Loss Exponent.

    PubMed

    Huang, Jiyan; Liu, Peng; Lin, Wei; Gui, Guan

    2016-09-08

    The localization of a sensor in wireless sensor networks (WSNs) has now gained considerable attention. Since the transmit power and path loss exponent (PLE) are two critical parameters in the received signal strength (RSS) localization technique, many RSS-based location methods, considering the case that both the transmit power and PLE are unknown, have been proposed in the literature. However, these methods require a search process, and cannot give a closed-form solution to sensor localization. In this paper, a novel RSS localization method with a closed-form solution based on a two-step weighted least squares estimator is proposed for the case with the unknown transmit power and uncertainty in PLE. Furthermore, the complete performance analysis of the proposed method is given in the paper. Both the theoretical variance and Cramer-Rao lower bound (CRLB) are derived. The relationships between the deterministic CRLB and the proposed stochastic CRLB are presented. The paper also proves that the proposed method can reach the stochastic CRLB.

  3. RSS-Based Method for Sensor Localization with Unknown Transmit Power and Uncertainty in Path Loss Exponent

    PubMed Central

    Huang, Jiyan; Liu, Peng; Lin, Wei; Gui, Guan

    2016-01-01

    The localization of a sensor in wireless sensor networks (WSNs) has now gained considerable attention. Since the transmit power and path loss exponent (PLE) are two critical parameters in the received signal strength (RSS) localization technique, many RSS-based location methods, considering the case that both the transmit power and PLE are unknown, have been proposed in the literature. However, these methods require a search process, and cannot give a closed-form solution to sensor localization. In this paper, a novel RSS localization method with a closed-form solution based on a two-step weighted least squares estimator is proposed for the case with the unknown transmit power and uncertainty in PLE. Furthermore, the complete performance analysis of the proposed method is given in the paper. Both the theoretical variance and Cramer-Rao lower bound (CRLB) are derived. The relationships between the deterministic CRLB and the proposed stochastic CRLB are presented. The paper also proves that the proposed method can reach the stochastic CRLB. PMID:27618055

  4. p53 Activity Dominates that of p73 upon Mdm4 Loss in Development and Tumorigenesis

    PubMed Central

    Tashakori, Mehrnoosh; Zhang, Yun; Xiong, Shunbin; You, M. James; Lozano, Guillermina

    2015-01-01

    Mdm4 negatively regulates the p53 tumor suppressor. Mdm4 loss in mice leads to an embryonic lethal phenotype that is p53-dependent. Biochemical studies indicate that Mdm4 also binds p73, a member of the p53 family, with higher affinity than p53. In this study, the significance of the Mdm4 and p73 interaction in vivo during embryogenesis and tumorigenesis was examined. The data revealed that p73 loss does not rescue either the early Mdm4-deficient embryonic lethality or the runted phenotype of Mdm4Δ2/Δ2 p53+/− embryos. Furthermore, studies in the developing central nervous system (CNS) wherein both genes have prominent roles indicated that loss of p73 also did not rescue the Mdm4-null brain phenotype as does p53 loss. This p53 dependency occurred despite evidence for p73-specific transcriptional activity. In tumor studies, the combination of Mdm4 overexpression and p73 loss did not alter survival of mice or the tumor spectrum as compared to Mdm4 overexpression alone. In summary, these data demonstrate that the Mdm4-p73 axis cannot override the dominant role of p53 in development and tumorigenesis. Implications Genetic characterization of the Mdm4 and p73 interaction during development and tumorigenesis suggests new insight into the role of p53 family members, which may influence treatment options for patients. PMID:26527653

  5. Theory of direct and indirect effect of two-photon absorption on nonlinear optical losses in high power semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Avrutin, E. A.; Ryvkin, B. S.

    2017-01-01

    The effect of the transverse laser structure on two-photon absorption (TPA) related effects in high-power diode lasers is analysed theoretically. The direct effect of TPA is found to depend significantly on the transverse waveguide structure, and predicted to be weaker in broad and asymmetric waveguide designs. The indirect effect of TPA, via carrier generation in the waveguide and free-carrier absorption, is analysed for the case of a symmetric laser waveguide and shown to be strongly dependent on the active layer position. With the active layer near the mode peak, the indirect effect is weaker than the direct effect due to the population of TPA-created carriers being efficiently depleted by their diffusion and capture into the active layer, whereas for the active layer position strongly shifted towards the p-cladding, the indirect effect can become the dominant power limitation at very high currents. It is shown that for optimizing a laser design for pulsed high power operation, both TPA related effects and the inhomogeneous carrier accumulation in the waveguide caused by diffusive current need to be taken into account.

  6. Actively coupled cavity ringdown spectroscopy with low-power broadband sources.

    PubMed

    Petermann, Christian; Fischer, Peer

    2011-05-23

    We demonstrate a coupling scheme for cavity enhanced absorption spectroscopy that makes use of an intracavity acousto-optical modulator to actively switch light into (and out of) a resonator. This allows cavity ringdown spectroscopy (CRDS) to be implemented with broadband nonlaser light sources with spectral power densities of less than 30μW/nm. Although the acousto-optical element reduces the ultimate detection limit by introducing additional losses, it permits absorptivities to be measured with a high dynamic range, especially in lossy environments. Absorption measurements for the forbidden transition of gaseous oxygen in air at ∼760nm are presented using a low-coherence cw-superluminescent diode. The same setup was electronically configured to cover absorption losses from 1.8×10-8cm-1 to 7.5% per roundtrip. This could be of interest in process analytical applications.

  7. Ovarian insufficiency and early pregnancy loss induced by activation of the innate immune system

    PubMed Central

    Erlebacher, Adrian; Zhang, Dorothy; Parlow, Albert F.; Glimcher, Laurie H.

    2004-01-01

    We describe a murine model of early pregnancy failure induced by systemic activation of the CD40 immune costimulatory pathway. Although fetal loss involved an NK cell intermediate, it was not due to lymphocyte-mediated destruction of the fetus and placenta. Rather, pregnancy failure resulted from impaired progesterone synthesis by the corpus luteum of the ovary, an endocrine defect in turn associated with ovarian resistance to the gonadotropic effects of prolactin. Pregnancy failure also required the proinflammatory cytokine TNF-α and correlated with the luteal induction of the prolactin receptor signaling inhibitors suppressor of cytokine signaling 1 (Socs1) and Socs3. Such links between immune activation and reproductive endocrine dysfunction may be relevant to pregnancy loss and other clinical disorders of reproduction. PMID:15232610

  8. Loss of Drosophila Vps16A enhances autophagosome formation through reduced Tor activity

    PubMed Central

    Takáts, Szabolcs; Varga, Ágnes; Pircs, Karolina; Juhász, Gábor

    2015-01-01

    The HOPS tethering complex facilitates autophagosome-lysosome fusion by binding to Syx17 (Syntaxin 17), the autophagosomal SNARE. Here we show that loss of the core HOPS complex subunit Vps16A enhances autophagosome formation and slows down Drosophila development. Mechanistically, Tor kinase is less active in Vps16A mutants likely due to impaired endocytic and biosynthetic transport to the lysosome, a site of its activation. Tor reactivation by overexpression of Rheb suppresses autophagosome formation and restores growth and developmental timing in these animals. Thus, Vps16A reduces autophagosome numbers both by indirectly restricting their formation rate and by directly promoting their clearance. In contrast, the loss of Syx17 blocks autophagic flux without affecting the induction step in Drosophila. PMID:26061715

  9. High dielectric constant, low loss and high photocatalytic activity in Gd doped ZnO systems

    NASA Astrophysics Data System (ADS)

    Divya, N. K.; Pradyumnan, P. P.

    2017-01-01

    Enhanced photocatalytic activity and high dielectric constant values are achieved by gadolinium (Gd) doping in ZnO. The changes that happened to the wurtzite structure of ZnO on doping are depicted in detail by using x-ray diffraction spectroscopy. The chemical composition is confirmed using energy dispersive x-ray spectroscopy (EDAX). The influence of Gd incorporation in the emission spectra of ZnO is analysed from photoluminescence studies. The photocatalytic activity enhancement occurred in ZnO system on Gd doping was explored by kinetic rate analysis. The optimum incorporation of Gd has enhanced the dielectric constant value and decreased the loss of pristine. The high dielectric constant value and low loss make the system suitable for large scale of applications in microelectronics. The work also proposes large scale synthesis of highly efficient fluorescent Gd doped ZnO photocatalysts.

  10. A Study Using a Monte Carlo Method of the Optimal Configuration of a Distribution Network in Terms of Power Loss Sensing

    PubMed Central

    Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

    2011-01-01

    Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels—is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI’s IntelliGrid research program. The European Union (EU), which represents Europe’s Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal

  11. A compact dual-wavelength Nd:LuVO4 laser with adjustable power-ratio between 1064 nm and 1342 nm lines by controlling polarization dependent loss

    NASA Astrophysics Data System (ADS)

    Qi, Yaoyao; Yu, Haijuan; Zhang, Jingyuan; Zhang, Ling; He, Chaojian; Lin, Xuechun

    2017-01-01

    We demonstrate a compact dual-wavelength operation of Nd:LuVO4 laser with a power-ratio adjustable between 1064 nm and 1342 nm lines in a compound cavity configuration. The output power at two wavelengths of the laser indicates that it depends not only on pumping-power and but also on the controllable polarization loss in the cavity. Also, the power-ratio, defined as ratio between the output power at 1064 nm and that at 1342 nm, can be adjusted from 0 to 8 or higher accurately by rotating a quarter-wave plate (QWP) in the cavity.

  12. Dose to man from a hypothetical loss-of-coolant accident at the Rancho Seco Nuclear Power Plant

    SciTech Connect

    Peterson, K.R.; Greenly, G.D.

    1981-02-01

    At the request of the Sacramento Municipal Utilities District, we used our computer codes, MATHEW and ADPIC, to assess the environmental impact of a loss-of-coolant accident at the Rancho Seco Nuclear Power Plant, about 40 kilometres southeast of Sacramento, California. Meteorological input was selected so that the effluent released by the accident would be transported over the Sacramento metropolitan area. With the release rates provided by the Sacramento Municipal Utilities District, we calculated the largest total dose for a 24-hour release as 70 rem about one kilometre northwest of the reactor. The largest total dose in the Sacramento metropolitan area is 780 millirem. Both doses are from iodine-131, via the forage-cow-milk pathway to an infant's thyroid. The largest dose near the nuclear plant can be minimized by replacing contaminated milk and by giving the cows dry feed. To our knowledge, there are no milk cows within the Sacramento metropolitan area.

  13. TrkB Activators for the Treatment of Traumatic Vision Loss

    DTIC Science & Technology

    2015-10-01

    receptor for brain -derived neurotrophic factor (BDNF). BDNF has been shown to have neuroprotective effects in a number of degeneration models ...4 HIOC has also demonstrated protective activity in an animal model for light-induced retinal degeneration, and can pass the blood- brain and blood...14. ABSTRACT Pressure waves due to explosions can damage the neurons of the eye and visual centers in the brain , leading to functional loss of

  14. Fast oscillatory activity in the anterior cingulate cortex: dopaminergic modulation and effect of perineuronal net loss

    PubMed Central

    Steullet, Pascal; Cabungcal, Jan-Harry; Cuénod, Michel; Do, Kim Q.

    2014-01-01

    Dopamine release in the prefrontal cortex plays a critical role in cognitive function such as working memory, attention and planning. Dopamine exerts complex modulation on excitability of pyramidal neurons and interneurons, and regulates excitatory and inhibitory synaptic transmission. Because of the complexity of this modulation, it is difficult to fully comprehend the effect of dopamine on neuronal network activity. In this study, we investigated the effect of dopamine on local high-frequency oscillatory neuronal activity (in β band) in slices of the mouse anterior cingulate cortex (ACC). We found that dopamine enhanced the power of these oscillations induced by kainate and carbachol, but did not affect their peak frequency. Activation of D2R and in a lesser degree D1R increased the oscillation power, while activation of D4R had no effect. These high-frequency oscillations in the ACC relied on both phasic inhibitory and excitatory transmission and functional gap junctions. Thus, dopamine released in the ACC promotes high-frequency synchronized local cortical activity which is known to favor information transfer, fast selection and binding of distributed neuronal responses. Finally, the power of these oscillations was significantly enhanced after degradation of the perineuronal nets (PNNs) enwrapping most parvalbumin interneurons. This study provides new insights for a better understanding of the abnormal prefrontal gamma activity in schizophrenia (SZ) patients who display prefrontal anomalies of both the dopaminergic system and the PNNs. PMID:25191228

  15. Loss of Frataxin activates the iron/sphingolipid/PDK1/Mef2 pathway in mammals

    PubMed Central

    Chen, Kuchuan; Ho, Tammy Szu-Yu; Lin, Guang; Tan, Kai Li; Rasband, Matthew N; Bellen, Hugo J

    2016-01-01

    Friedreich’s ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by mutations in Frataxin (FXN). Loss of FXN causes impaired mitochondrial function and iron homeostasis. An elevated production of reactive oxygen species (ROS) was previously proposed to contribute to the pathogenesis of FRDA. We recently showed that loss of frataxin homolog (fh), a Drosophila homolog of FXN, causes a ROS independent neurodegeneration in flies (Chen et al., 2016). In fh mutants, iron accumulation in the nervous system enhances the synthesis of sphingolipids, which in turn activates 3-phosphoinositide dependent protein kinase-1 (Pdk1) and myocyte enhancer factor-2 (Mef2) to trigger neurodegeneration of adult photoreceptors. Here, we show that loss of Fxn in the nervous system in mice also activates an iron/sphingolipid/PDK1/Mef2 pathway, indicating that the mechanism is evolutionarily conserved. Furthermore, sphingolipid levels and PDK1 activity are also increased in hearts of FRDA patients, suggesting that a similar pathway is affected in FRDA. DOI: http://dx.doi.org/10.7554/eLife.20732.001 PMID:27901468

  16. Measurement of magnetic losses by thermal method applied to power ferrites at high level of induction and frequency

    NASA Astrophysics Data System (ADS)

    Loyau, V.; Lo Bue, M.; Mazaleyrat, F.

    2009-02-01

    Classically, low frequency losses in soft magnetic materials and ferrites in particular are measured by flux metric method under sinusoidal waveform excitation voltage. However, in typical application of modern power electronics, the frequency currently exceeds 100 kHz. This feature is at the origin of a difficulty: the phase shift between current and voltage can be disturbed by current probe delay. Thus, the results can be affected by large errors. As a consequence, it becomes more and more important to develop alternative methods to measure losses in magnetic materials. It is proposed to use calorimetric method which is by principle free of the above mentioned problems. The experimental device is described in details and the results are reported for experiments conducted on a commercial Mn-Zn ferrite under sinusoidal waveform regime for frequencies varying from 10 to 200 kHz. Comparisons with flux metric measurement show that significant differences appear typically for Bf products above 5000 V/m2 (50 kHz×100 mT).

  17. Senescence-induced loss in photosynthesis enhances cell wall beta-glucosidase activity.

    PubMed

    Mohapatra, Pranab Kishor; Patro, Lichita; Raval, Mukesh Kumar; Ramaswamy, Nemmara Krishnan; Biswal, Udaya Chand; Biswal, Basanti

    2010-03-01

    A link between senescence-induced decline in photosynthesis and activity of beta-glucosidase is examined in the leaves of Arabidopsis. The enzyme is purified and characterized. The molecular weight of the enzyme is 58 kDa. It shows maximum activity at pH 5.5 and at temperature of 50 degrees C. Photosynthetic measurements and activity of the enzyme are conducted at different developmental stages including senescence of leaves. Senescence causes a significant loss in total chlorophyll, stomatal conductance, rate of evaporation and in the ability of the leaves for carbon dioxide fixation. The process also brings about a decline in oxygen evolution, quantum yield of photosystem II (PS II) and quantum efficiency of PS II photochemistry of thylakoid membrane. The loss in photosynthesis is accompanied by a significant increase in the activity of the cell wall-bound beta-glucosidase that breaks down polysaccharides to soluble sugars. The loss in photosynthesis as a signal for the enhancement in the activity of the enzyme is confirmed from the observation that incubation of excised mature leaves in continuous dark or in light with a photosynthesis inhibitor 3-(3,4-dichlorophenyl)-1, 1-dimethylurea (DCMU) that leads to sugar starvation enhances the activity of the enzyme. The work suggests that in the background of photosynthetic decline, the polysaccharides bound to cell wall that remains intact even during late phase of senescence may be the last target of senescing leaves for a possible source of sugar for remobilization and completion of the energy-dependent senescence program.

  18. Quench Protection System based on Active Power Method

    NASA Astrophysics Data System (ADS)

    Nanato, Nozomu

    In superconducting coils, local and excessive joule heating may give damage to the superconducting windings when a quench occurs and therefore it is essential that the quench is detected quickly and precisely so that the coils can be safely discharged. We have presented a quench protection system based on the active power method which detects a quench by measuring the instantaneous active power generated in a superconducting coil. The protection system based on this method is strong against the inductive voltage and noise which may cause insufficient quench recognition. However, the proposed system is useful for a single coil but it is vulnerable to the magnetically coupled multi-coil such as high field superconducting coils. Because the proposed system can not avoid insufficient quench recognition by the mutual inductive voltage from the other coils. This paper presents a method to improve the characteristics of the active power method by cancelling the mutual inductive voltage. The experimental results of the quench protection for small Bi2223 coils show that the proposed system is useful for the magnetically coupled coils.

  19. Bodybuilding, Energy, and Weight-Loss Supplements are Associated with Deployment and Physical Activity in U.S. Military Personnel

    DTIC Science & Technology

    2012-05-01

    the herbal weight-loss supplement hydroxycut. Ann Intern Med. 2005;142:477–478. 22. Baum M, Weiss M. The influence of a taurine containing drink on...Naval Health Research Center Bodybuilding, Energy, and Weight-Loss Supplements Are Associated With Deployment and Physical Activity in U.S...Weight-Loss Supplements Are Associated With Deployment and Physical Activity in U.S. Military Personnel ISABEL G. JACOBSON, MPH, JAIME L. HORTON, BS

  20. [Occupational radiation exposures during maintenance activities at nuclear power plants].

    PubMed

    Imahori, A

    1987-11-01

    Occupational exposures at nuclear power plants occur mostly during maintenance activities rather than during routine reactor operation. In this paper, statistical summaries of occupational exposures during routine maintenance activities for the years 1982-84 at nuclear power plants in Japan are presented, including comparison of the exposure levels by reactor type and by plant age. Average annual collective doses per reactor for BWRs and PWRs are 7.30 man-Sv and 2.84 man-Sv, respectively, and 78% and 89% of annual doses are incurred during maintenance activities. Average annual outage days of BWRs and PWRs for routine maintenance are 102 d and 97 d. Annual collective doses per reactor, most of which occur during maintenance activities, usually increase with plant age. Higher collective doses are observed for routine maintenance performed on older reactors as compared to newer reactors, especially in BWRs. Collective doses accrued during respective routine maintenance activities have a significant correlation with duration of maintenance and number of workers involved in maintenance.

  1. Bipedality and hair loss in human evolution revisited: The impact of altitude and activity scheduling.

    PubMed

    Dávid-Barrett, Tamás; Dunbar, Robin I M

    2016-05-01

    Bipedality evolved early in hominin evolution, and at some point was associated with hair loss over most of the body. One classic explanation (Wheeler 1984: J. Hum. Evol. 13, 91-98) was that these traits evolved to reduce heat overload when australopiths were foraging in more open tropical habitats where they were exposed to the direct effects of sunlight at midday. A recent critique of this model (Ruxton & Wilkinson 2011a: Proc. Natl. Acad. Sci. USA 108, 20965-20969) argued that it ignored the endogenous costs of heat generated by locomotion, and concluded that only hair loss provided a significant reduction in heat load. We add two crucial corrections to this model (the altitude at which australopiths actually lived and activity scheduling) and show that when these are included there are substantial reductions in heat load for bipedal locomotion even for furred animals. In addition, we add one further consideration to the model: we extend the analysis across the full 24 h day, and show that fur loss could not have evolved until much later because of the thermoregulatory costs this would have incurred at the altitudes where australopiths actually lived. Fur loss is most likely associated with the exploitation of open habitats at much lower altitudes at a much later date by the genus Homo.

  2. CONNECTING FLARES AND TRANSIENT MASS-LOSS EVENTS IN MAGNETICALLY ACTIVE STARS

    SciTech Connect

    Osten, Rachel A.; Wolk, Scott J.

    2015-08-10

    We explore the ramification of associating the energetics of extreme magnetic reconnection events with transient mass-loss in a stellar analogy with solar eruptive events. We establish energy partitions relative to the total bolometric radiated flare energy for different observed components of stellar flares and show that there is rough agreement for these values with solar flares. We apply an equipartition between the bolometric radiated flare energy and kinetic energy in an accompanying mass ejection, seen in solar eruptive events and expected from reconnection. This allows an integrated flare rate in a particular waveband to be used to estimate the amount of associated transient mass-loss. This approach is supported by a good correspondence between observational flare signatures on high flaring rate stars and the Sun, which suggests a common physical origin. If the frequent and extreme flares that young solar-like stars and low-mass stars experience are accompanied by transient mass-loss in the form of coronal mass ejections, then the cumulative effect of this mass-loss could be large. We find that for young solar-like stars and active M dwarfs, the total mass lost due to transient magnetic eruptions could have significant impacts on disk evolution, and thus planet formation, and also exoplanet habitability.

  3. Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

    SciTech Connect

    Ghan, L.S.; Ortiz, M.G.

    1991-01-01

    A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission's (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.

  4. Modeling operator actions during a small break loss-of-coolant accident in a Babcock and Wilcox nuclear power plant

    SciTech Connect

    Ghan, L.S.; Ortiz, M.G.

    1991-12-31

    A small break loss-of-accident (SBLOCA) in a typical Babcock and Wilcox (B&W) nuclear power plant was modeled using RELAP5/MOD3. This work was performed as part of the United States Regulatory Commission`s (USNRC) Code, Scaling, Applicability and Uncertainty (CSAU) study. The break was initiated by severing one high pressure injection (HPI) line at the cold leg. Thus, the small break was further aggravated by reduced HPI flow. Comparisons between scoping runs with minimal operator action, and full operator action, clearly showed that the operator plays a key role in recovering the plant. Operator actions were modeled based on the emergency operating procedures (EOPs) and the Technical Bases Document for the EOPs. The sequence of operator actions modeled here is only one of several possibilities. Different sequences of operator actions are possible for a given accident because of the subjective decisions the operator must make when determining the status of the plant, hence, which branch of the EOP to follow. To assess the credibility of the modeled operator actions, these actions and results of the simulated accident scenario were presented to operator examiners who are familiar with B&W nuclear power plants. They agreed that, in general, the modeled operator actions conform to the requirements set forth in the EOPs and are therefore plausible. This paper presents the method for modeling the operator actions and discusses the simulated accident scenario from the viewpoint of operator actions.

  5. Physical activity for weight loss in children: is there any compensatory mechanism?

    PubMed

    Thivel, David; Duché, Pascale

    2014-05-01

    Although physical activity is primarily considered for its effects on energy expenditure for prevention and treatment of both overweight and obesity, its role in the regulation and control of energy balance seems more complex. Not only does physical activity affect energy expenditure, it also leads to modifications in energy intake and appetite that have been identified in children and that should be considered for weight loss. It also appears that it may not systematically favor increased energy expenditure due to individual differences in compensatory responses. This brief paper summarizes the pediatric evidence regarding those potential compensatory responses to physical activity and suggests that these compensatory responses of increasing physical activity levels may depend on children's adiposity status.

  6. Developments in Power efficient dissociation of CO2 using non-equilibrium plasma activation

    NASA Astrophysics Data System (ADS)

    van de Sanden, Richard

    2013-09-01

    Sustainable energy generation by means of, either photovoltaic conversion, concentrated solar power or wind, will certainly form a significant part of the energy mix in 2025. The intermittency as well as the temporal variation and the regional spread of this energy source, however, requires a means to store and transport energy on a large scale. In this presentation the means of storage will be addressed of sustainable energy transformed into fuels and the prominent role plasma science and technology can play in this great challenge. The storage of sustainable energy in these so called solar fuels, e.g. hydrocarbons and alcohols, by means of artificial photosynthesis from the feedstock CO2 and H2O, will enable a CO2 neutral power generation infrastructure, which is close to the present infrastructure based on fossil fuels. The challenge will be to achieve power efficient dissociation of CO2 or H2O or both, after which traditional chemical conversion (Fisher-Tropsch, Sabatier, etc.) towards fuels can take place. A promising route is the dissociation or activation of CO2 by means of plasma, possible combined with catalysis. Taking advantage of non-equilibrium plasma conditions to reach optimal energy efficiency we have started a solar fuels program at the beginning of 2012 focusing on CO2 plasma dissociation into CO and O2. The plasma is generated in a low loss microwave cavity with microwave powers up to 10 kW using a supersonic expansion to quench the plasma and prevent vibrational-translational relaxation losses. New ideas on the design of the facility and results on power efficient conversion (more then 50%) of large CO2 flows (up to 75 standard liter per minute with 11% conversion) at low gas temperatures will be presented.

  7. Chromatin structure and gene expression changes associated with loss of MOP1 activity in Zea mays.

    PubMed

    Madzima, Thelma F; Huang, Ji; McGinnis, Karen M

    2014-07-01

    Though the mechanisms governing nuclear organization are not well understood, it is apparent that epigenetic modifications coordinately modulate chromatin organization as well as transcription. In maize, MEDIATOR OF PARAMUTATION1 (MOP1) is required for 24 nt siRNA-mediated epigenetic regulation and transcriptional gene silencing via a putative Pol IV- RdDM pathway. To elucidate the mechanisms of nuclear chromatin organization, we investigated the relationship between chromatin structure and transcription in response to loss of MOP1 function. We used a microarray based micrococcal nuclease sensitivity assay to identify genome-wide changes in chromatin structure in mop1-1 immature ears and observed an increase in chromatin accessibility at chromosome arms associated with loss of MOP1 function. Within the many genes misregulated in mop1 mutants, we identified one subset likely to be direct targets of epigenetic transcriptional silencing via Pol-IV RdDM. We found that target specificity for MOP1-mediated RdDM activity is governed by multiple signals that include accumulation of 24 nt siRNAs and the presence of specific classes of gene-proximal transposons, but neither of these attributes alone is sufficient to predict transcriptional misregulation in mop1-1 homozygous mutants. Our results suggest a role for MOP1 in regulation of higher-order chromatin organization where loss of MOP1 activity at a subset of loci triggers a broader cascade of transcriptional consequences and genome-wide changes in chromatin structure.

  8. Determining the Nature and Origin of Mass Loss from Active Asteroid P/2013 P5

    NASA Astrophysics Data System (ADS)

    Jewitt, David

    2014-10-01

    We propose a program of WFC3 images of active asteroid P/2013 P5 in order to determine the nature and origin of mass loss from this object. P5 ejects dust episodically, creating a multi-tailed appearance unlike that of any other known asteroid or comet. The ejection is thought to result from surface rotational instabilities (a process called "mass-shedding" by modelers). We will test the role of rotation by measuring the lightcurve of the nucleus and we will study the evolution of continued mass loss through Cycle 22. Rotational breakup and rotational mass-shedding are suspected to be the main mechanisms of destruction for sub-kilometer asteroids. Neither has been observed before but, between P/2013 P5 and P/2013 R3 (subject of another proposal) we have the first, potentially ground-breaking opportunities to observe both.

  9. MHD activity and energy loss during beta saturation and collapse at high beta poloidal in PBX

    SciTech Connect

    Kugel, H.W.; Sesnic, S.; Bol, K.; Chance, M.; Fishman, H.; Fonck, R.; Gammel, G.; Kaita, R.; Kaye, S.; LeBlanc, B.

    1987-10-01

    High-..beta.. experiments, in medium to high-q tokamak plasmas, exhibit a temporal ..beta.. saturation and collapse. This behavior has been attributed to ballooning, ideal kink, or tearing modes. In PBX, a unique diagnostic capability allowed studies of the relation between MHD and energy loss for neutral-beam-heated (<6 MW), mildly indented (10 to 15%), nearly steady I/sub p/ discharges that approached the Troyon-Gruber limit. Under these conditions, correlations between MHD activity and energy losses have shown that the latter can be almost fully accounted for by various long wavelength MHD instabilities and that there is no need to invoke high-n ballooning modes in PBX. 6 refs., 4 figs.

  10. Loss of succinate dehydrogenase activity results in dependency on pyruvate carboxylation for cellular anabolism.

    PubMed

    Lussey-Lepoutre, Charlotte; Hollinshead, Kate E R; Ludwig, Christian; Menara, Mélanie; Morin, Aurélie; Castro-Vega, Luis-Jaime; Parker, Seth J; Janin, Maxime; Martinelli, Cosimo; Ottolenghi, Chris; Metallo, Christian; Gimenez-Roqueplo, Anne-Paule; Favier, Judith; Tennant, Daniel A

    2015-11-02

    The tricarboxylic acid (TCA) cycle is a central metabolic pathway responsible for supplying reducing potential for oxidative phosphorylation and anabolic substrates for cell growth, repair and proliferation. As such it thought to be essential for cell proliferation and tissue homeostasis. However, since the initial report of an inactivating mutation in the TCA cycle enzyme complex, succinate dehydrogenase (SDH) in paraganglioma (PGL), it has become clear that some cells and tissues are not only able to survive with a truncated TCA cycle, but that they are also able of supporting proliferative phenotype observed in tumours. Here, we show that loss of SDH activity leads to changes in the metabolism of non-essential amino acids. In particular, we demonstrate that pyruvate carboxylase is essential to re-supply the depleted pool of aspartate in SDH-deficient cells. Our results demonstrate that the loss of SDH reduces the metabolic plasticity of cells, suggesting vulnerabilities that can be targeted therapeutically.

  11. Dual Sensory Loss and Depressive Symptoms: The Importance of Hearing, Daily Functioning, and Activity Engagement

    PubMed Central

    Kiely, Kim M.; Anstey, Kaarin J.; Luszcz, Mary A.

    2013-01-01

    Background: The association between dual sensory loss (DSL) and mental health has been well established. However, most studies have relied on self-report data and lacked measures that would enable researchers to examine causal pathways between DSL and depression. This study seeks to extend this research by examining the effects of DSL on mental health, and identify factors that explain the longitudinal associations between sensory loss and depressive symptoms. Methods: Piecewise linear-mixed models were used to analyze 16-years of longitudinal data collected on up to five occasions from 1611 adults (51% men) aged between 65 and 103 years. Depressive symptoms were assessed by the Centre for Epidemiological Studies Depression (CES-D). Vision loss (VL) was defined by corrected visual acuity >0.3 logMAR in the better eye, blindness, or glaucoma. Hearing loss (HL) was defined by pure-tone average (PTA) >25 dB in the better hearing ear. Analyses were adjusted for socio-demographics, medical conditions, lifestyle behaviors, activities of daily living (ADLs), cognitive function, and social engagement. Results: Unadjusted models indicated that higher levels of depressive symptoms were associated with HL (B = 1.16, SE = 0.33) and DSL (B = 2.15, SE = 0.39) but not VL. Greater rates of change in depressive symptoms were also evident after the onset of HL (B = 0.16, SE = 0.06, p < 0.01) and DSL (B = 0.30, SE = 0.09, p < 0.01). The associations between depressive symptoms and sensory loss were explained by difficulties with ADLs, and social engagement. Conclusion: Vision and HL are highly prevalent among older adults and their co-occurrence may compound their respective impacts on health, functioning, and activity engagement, thereby exerting strong effects on the mental health and wellbeing of those affected. There is therefore a need for rehabilitation programs to be sensitive to the combined effects of sensory loss on individuals

  12. Sleep Loss Activates Cellular Inflammation and Signal Transducer and Activator of Transcription (STAT) Family Proteins in Humans

    PubMed Central

    Irwin, Michael R.; Witarama, Tuff; Caudill, Marissa; Olmstead, Richard; Breen, Elizabeth Crabb

    2014-01-01

    Sleep disturbance and short sleep duration are associated with inflammation and related disorders including cardiovascular disease, arthritis, diabetes mellitus, and certain cancers. This study was undertaken to test the effects of experimental sleep loss on spontaneous cellular inflammation and activation of signal transducer and activator of transcription (STAT) family proteins, which together promote an inflammatory microenvironment. In 24 healthy adults (16 females; 8 males), spontaneous production of IL-6 and TNF in monocytes and spontaneous intranuclear expression of activated STAT1, STAT3, and STAT5 in peripheral blood mononuclear cells (PBMC), monocyte-, and lymphocyte populations were measured in the morning after uninterrupted baseline sleep, partial sleep deprivation (PSD, sleep period from 3 a.m. to 7 a.m.), and recovery sleep. Relative to baseline, spontaneous monocytic expression of IL-6 and TNF-α was significantly greater after PSD (P<0.02) and after recovery sleep (P<0.01). Relative to baseline, spontaneous monocytic expression of activated STAT 1 and STAT 5 was significantly greater after recovery sleep (P<0.007P<0.02, respectively) but not STAT 3 (P=0.09). No changes in STAT1, STAT3, or STAT5 were found in lymphocyte populations. Sleep loss induces activation of spontaneous cellular innate immunity and of STAT family proteins, which together map the dynamics of sleep loss on the molecular signaling pathways that regulate inflammatory and other immune responses. Treatments that target short sleep duration have the potential to constrain inflammation and reduce the risk for inflammatory disorders and some cancers in humans. PMID:25451613

  13. Experimental study of loss mechanisms of AgAu/PbBi-2223 tapes with twisted filaments under perpendicular AC magnetic fields at power frequencies

    NASA Astrophysics Data System (ADS)

    Martínez, E.; Yang, Y.; Beduz, C.; Huang, Y. B.

    2000-05-01

    AC losses under perpendicular AC fields have been measured at 77 K and power frequencies for multifilamentary AgAu (10 wt.%)/Bi-2223 tapes with filaments twisted at different pitches. Using simultaneous measurements of the first and higher harmonics of the voltage induced in the pick-up coil, the main loss contributions (superconductor and coupling current losses) have been obtained separately. At power frequencies, twisting produces the desired uncoupling of the filaments at fields lower than the coupling field, which has also been determined experimentally. In the uncoupled-filament regime, the superconductor losses are reduced strongly with respect to the untwisted tapes. The reduction of the total loss with twisting is also observed. However, due to the important contribution of the coupling current losses for this field orientation, a very small pitch (<5 mm) is necessary for a considerably lower loss than that of untwisted tapes. The dependence of the coupling field and coupling current losses on the twist pitch has been analysed and compared with the theoretical predictions.

  14. A novel modular approach to active power-line harmonic filtering in distribution systems

    NASA Astrophysics Data System (ADS)

    El Shatshat, Ramadan A.

    The objective of this research is to develop an efficient and reliable modular active harmonic filter system to realize a cost-effective solution to the harmonic problem. The proposed filter system consists of a number CSC modules, each dedicated to filter a specific harmonic of choice (Frequency-Splitting Approach). The power rating of the modules will decrease and their switching frequency will increase as the order of the harmonic to be filtered is increased. The overall switching losses are minimized due to the selected harmonic elimination and balanced a "power rating"-"switching frequency" product. Two ADALINEs are proposed as a part of the filter controller for processing the signals obtained from the power-line. One ADALINE (the Current ADALINE) extracts the fundamental and harmonic components of the distorted current. The other ADALINE (the Voltage ADALINE) estimates the line voltage. The outputs of both ADALINEs are used to construct the modulating signals of the filter modules. The proposed controller decides which CSC filter module(s) is connected to the electric grid. The automated connection of the corresponding filter module(s) is based on decision-making rules in such a way that the IEEE 519-1992 limits are not violated. The information available on the magnitude of each harmonic component allows us to select the active filter bandwidth (i.e., the highest harmonic to be suppressed). This will result in more efficiency and higher performance. The proposed controller adjusts the I dc in each CSC module according to the present magnitude of the corresponding harmonic current. This results in optimum dc-side current value and minimal converter losses. The comparison of the proposed modular active filter scheme and the conventional one converter scheme on practical use in industry is presented. This comparison shows that the proposed solution is more economical, reliable and flexible compared to conventional one. High speed and accuracy of ADALINE, self

  15. Behavioral Weight Loss and Physical Activity Intervention in Obese Adults with Asthma. A Randomized Trial

    PubMed Central

    Strub, Peg; Xiao, Lan; Lavori, Philip W.; Camargo, Carlos A.; Wilson, Sandra R.; Gardner, Christopher D.; Buist, A. Sonia; Haskell, William L.; Lv, Nan

    2015-01-01

    Rationale: The effect of weight loss on asthma in obese adults warrants rigorous investigation. Objectives: To examine an evidence-based, practical, and comprehensive lifestyle intervention targeting modest weight loss and increased physical activity for asthma control. Methods: The trial randomized 330 obese adults with uncontrolled asthma to receive usual care enhanced with a pedometer, a weight scale, information about existing weight management services at the participating clinics, and an asthma education DVD, or with these tools plus the 12-month intervention. Measurements and Main Results: The primary outcome was change in Asthma Control Questionnaire (ACQ) scores from baseline to 12 months. Participants (mean [SD] age, 47.6 [12.4] yr) were 70.6% women, 20.0% non-Hispanic black, 20.3% Hispanic/Latino, and 8.2% Asian/Pacific Islander. At baseline, they were obese (mean [SD] body mass index, 37.5 [5.9] kg/m2) and had uncontrolled asthma (Asthma Control Test score, 15.1 [3.8]). Compared with control subjects, intervention participants achieved significantly greater mean weight loss (±SE) (intervention, −4.0 ± 0.8 kg vs. control, −2.1 ± 0.8 kg; P = 0.01) and increased leisure-time activity (intervention, 418.2 ± 110.6 metabolic equivalent task–min/wk vs. control, 178.8 ± 109.1 metabolic equivalent task–min/wk; P = 0.05) at 12 months. But between-treatment mean (±SE) differences were not significant for ACQ changes (intervention, –0.3 ± 0.1 vs. control, –0.2 ± 0.1; P = 0.92) from baseline (mean [SD], 1.4 [0.8]), nor for any other clinical asthma outcomes (e.g., spirometric results and asthma exacerbations). Among all participants regardless of treatment assignment, weight loss of 10% or greater was associated with a Cohen d effect of 0.76 and with 3.78 (95% confidence interval, 1.72–8.31) times the odds of achieving clinically significant reductions (i.e., ≥0.5) on ACQ as stable weight (<3% loss or gain from

  16. Allocation of extracellular enzymatic activity in relation to litter composition, N deposition, and mass loss

    USGS Publications Warehouse

    Sinsabaugh, R. L.; Carreiro, M.M.; Repert, D.A.

    2002-01-01

    Decomposition of plant material is a complex process that requires interaction among a diversity of microorganisms whose presence and activity is subject to regulation by a wide range of environmental factors. Analysis of extracellular enzyme activity (EEA) provides a way to relate the functional organization of microdecomposer communities to environmental variables. In this study, we examined EEA in relation to litter composition and nitrogen deposition. Mesh bags containing senescent leaves of Quercus borealis (red oak), Acer rubrum (red maple) and Cornus florida (flowering dogwood) were placed on forest floor plots in southeastern New York. One-third of the plots were sprayed monthly with distilled water. The other plots were sprayed monthly with NH4NO3 solution at dose rates equivalent to 2 or 8 g N m-2 y-1. Mass loss, litter composition, fungal mass, and the activities of eight enzymes were measured on 13 dates for each litter type. Dogwood was followed for one year, maple for two, oak for three, For each litter type and treatment, enzymatic turnover activities were calculated from regressions of LN (%mass remaining) vs. cumulative activity. The decomposition of dogwood litter was more efficient than that of maple and oak. Maple litter had the lowest fungal mass and required the most enzymatic work to decompose, even though its mass loss rate was twice that of oak. Across litter types, N amendment reduced apparent enzymatic efficiencies and shifted EEA away from N acquisition and toward P acquisition, and away from polyphenol oxidation and toward polysaccharide hydrolysis. The effect of these shifts on decomposition rate varied with litter composition: dogwood was stimulated, oak was inhibited and maple showed mixed effects. The results show that relatively small shifts in the activity of one or two critical enzymes can significantly alter decomposition rates.

  17. Medial frontal cortex activity and loss-related responses to errors.

    PubMed

    Taylor, Stephan F; Martis, Brian; Fitzgerald, Kate D; Welsh, Robert C; Abelson, James L; Liberzon, Israel; Himle, Joseph A; Gehring, William J

    2006-04-12

    Making an error elicits activity from brain regions that monitor performance, especially the medial frontal cortex (MFC). However, uncertainty exists about whether the posterior or anterior/rostral MFC processes errors and to what degree affective responses to errors are mediated in the MFC, specifically the rostral anterior cingulate cortex (rACC). To test the hypothesis that rACC mediates a type of affective response, we conceptualized affect in response to an error as a reaction to loss and amplified this response with a monetary penalty. While subjects performed a cognitive interference task during functional magnetic resonance imaging, hemodynamic activity in the rACC was significantly greater when subjects lost money as a result of an error compared with errors that did not lead to monetary loss. A significant interaction between the incentive conditions and error events demonstrated that the effect was not merely attributable to working harder to win (or not lose) money, although an effect of motivation was noted in the mid-MFC. Activation foci also occurred in similar regions of the posterior MFC for error and interference processing, which were not modulated by the incentive conditions. However, at the level of the individual subject, substantial functional variability occurred along the MFC during error processing, including foci in the rostral/anterior extent of the MFC not appearing in the group analysis. The findings support the hypothesis that the rostral extent of the MFC (rACC) processes loss-related responses to errors, and individual differences may account for some of the reported variation of error-related foci in the MFC.

  18. 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.

  19. 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.

  20. Influence of power on the surface loss reaction of F radicals in a low pressure CF4:O2 ICP discharge

    NASA Astrophysics Data System (ADS)

    Setareh, Mahsa; Farnia, Morteza; Maghari, Ali; University of Tehran Team

    2014-10-01

    A zero dimensional modeling code Global_kin, developed by Kushner is applied to model the CF4/O2 radio frequency inductively coupled plasma at applied powers of 80-300 W, pressure of 25 mTorr and temperature of 400 K. The calculated results indicated that the Fluorine (F) is the dominant radical produced in CF4:O2 discharge which is lost mostly at the walls rather than in formation of F2 molecules. We calculated the time integrated rate of F loss at the wall together with the relative contribution of wall reactions on the total loss of F corresponding to the sticking probabilities. The model predicts that although the absolute time integrated loss rates at the walls increase with power, but the relative contribution of the wall loss process decreases slightly upon higher powers. Furthermore, at lower O2 contents (or high CF4 contents), the relative contribution of the wall loss process is much lower because F radicals can also get lost in reactions with other plasma species such as CF3 to form again CF4. At equal contents of O2 and CF4, 35-45% of the F radicals are lost at the walls, depending on the power. The numerical modeling results for CF4 decomposition into new products are validated based on experimental data from literature.

  1. Losses, gain, and lasing in organic and perovskite active materials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pourdavoud, Neda; Riedl, Thomas J.

    2016-09-01

    Organic solid state lasers (OSLs) based on semiconducting polymers or small molecules have seen some significant progress over the past decade. Highly efficient organic gain materials combined with high-Q resonator geometries (distributed feedback (DFB), VCSEL, etc.) have enabled OSLs, optically pumped by simple inorganic laser diodes or even LEDs. However, some fundamental goals remain to be reached, like continuous wave (cw) operation and injection lasing. I will address various loss mechanisms related to accumulated triplet excitons or long-lived polarons that in combination with the particular photo-physics of organic gain media state the dominant road-blocks on the way to reach these goals. I will discuss the recent progress in fundamental understanding of these loss processes, which now provides a solid basis for modelling, e.g. of laser dynamics. Avenues to mitigate these fundamental loss mechanisms, e.g. by alternative materials will be presented. In this regard, a class of gain materials based on organo-lead halide perovskites re-entered the scene as light emitters, recently. Enjoying a tremendous lot of attention as active material for solution processed solar cells with a 20+% efficiency, they have recently unveiled their exciting photo-physics for lasing applications. Optically pumped lasing in these materials has been achieved. I will discuss some of the unique properties that render this class of materials a promising candidate to overcome some of the limitations of "classical" organic gain media.

  2. Measuring Outcomes in Adult Weight Loss Studies That Include Diet and Physical Activity: A Systematic Review

    PubMed Central

    Millstein, Rachel A.

    2014-01-01

    Background. Measuring success of obesity interventions is critical. Several methods measure weight loss outcomes but there is no consensus on best practices. This systematic review evaluates relevant outcomes (weight loss, BMI, % body fat, and fat mass) to determine which might be the best indicator(s) of success. Methods. Eligible articles described adult weight loss interventions that included diet and physical activity and a measure of weight or BMI change and body composition change. Results. 28 full-text articles met inclusion criteria. Subjects, settings, intervention lengths, and intensities varied. All studies measured body weight (−2.9 to −17.3 kg), 9 studies measured BMI (−1.1 to −5.1 kg/m2), 20 studies measured % body fat (−0.7 to −10.2%), and 22 studies measured fat mass (−0.9 to −14.9 kg). All studies found agreement between weight or BMI and body fat mass or body fat % decreases, though there were discrepancies in degree of significance between measures. Conclusions. Nearly all weight or BMI and body composition measures agreed. Since body fat is the most metabolically harmful tissue type, it may be a more meaningful measure of health change. Future studies should consider primarily measuring % body fat, rather than or in addition to weight or BMI. PMID:25525513

  3. Paralleling power MOSFETs in their active region: Extended range of passively forced current sharing

    NASA Technical Reports Server (NTRS)

    Niedra, Janis M.

    1989-01-01

    A simple passive circuit that improves current balance in parallelled power MOSFETs that are not precisely matched and that are operated in their active region from a common gate drive are exhibited. A nonlinear circuit consisting of diodes and resistors generates the differential gate potential required to correct for unbalance while maintaining low losses over a range of current. Also application of a thin tape wound magnetic core to effect dynamic current balance is reviewed, and a simple theory is presented showing that for operation in the active region the branch currents tend to revert to their normal unbalanced values even if the core is not driven into saturation. Results of several comparative experiments are given.

  4. Active pharmaceutical ingredients detected in herbal food supplements for weight loss sampled on the Dutch market.

    PubMed

    Reeuwijk, Noortje M; Venhuis, Bastiaan J; de Kaste, Dries; Hoogenboom, Ron L A P; Rietjens, Ivonne M C M; Martena, Martijn J

    2014-01-01

    Herbal food supplements claiming to reduce weight may contain active pharmacological ingredients (APIs) that can be used for the treatment of overweight and obesity. The aim of this study was to determine whether herbal food supplements for weight loss on the Dutch market contain APIs with weight loss properties. Herbal food supplements intended for weight loss (n = 50) were sampled from August 2004 to May 2013. An HPLC-DAD-MS/MS method was used to screen for the presence of the APIs in herbal supplements. In 24 samples the APIs sibutramine, desmethylsibutramine (DMS), didesmethylsibutramine (DDMS), rimonabant, sildenafil and/or the laxative phenolphthalein were identified 41 times. The presence of these APIs was, however, not stated on the label. The potential pharmacological effects of the detected APIs were estimated using data from reported effective doses of approved drugs. Use of 20 of the 24 herbal food supplements may result in potential pharmacological effects. Furthermore, risk assessment of phenolphthalein, a suspected carcinogen and found to be present in 10 supplements, based on the margin of exposure (MOE) approach, resulted in MOE values of 96-30,000. MOE values lower than 10,000 (96-220) were calculated for the daily intake levels of four out of these 10 supplements in which phenolphthalein was found. However, taking into account that weight loss preparations may be used for only a few weeks or months rather than during a lifetime, MOE values may be two to three orders of magnitude higher. The current study shows that the use of food supplements with sibutramine, DMS, DDMS and/or phenolphthalein could result in pharmacological effects.

  5. Acute canine distemper encephalitis is associated with rapid neuronal loss and local immune activation.

    PubMed

    Rudd, Penny A; Bastien-Hamel, Louis-Etienne; von Messling, Veronika

    2010-04-01

    For most virus infections of the central nervous system (CNS), immune-mediated damage, the route of inoculation and death of infected cells all contribute to the pathology observed. To investigate the role of these factors in early canine distemper neuropathogenesis, we infected ferrets either intranasally or intraperitoneally with the neurovirulent canine distemper virus strain Snyder Hill. Regardless of the route of inoculation, the virus primarily targeted the olfactory bulb, brainstem, hippocampus and cerebellum, whereas only occasional foci were detected in the cortex. The infection led to widespread neuronal loss, which correlated with the clinical signs observed. Increased numbers of activated microglia, reactive gliosis and different pro-inflammatory cytokines were detected in the infected areas, suggesting that the presence and ultimate death of infected cells at early times after infection trigger strong local immune activation, despite the observed systemic immunosuppression.

  6. Estimation of steady-state and transcient power distributions for the RELAP analyses of the 1963 loss-of-flow and loss-of-pressure tests at BR2.

    SciTech Connect

    Dionne, B.; Tzanos, C. P.

    2011-05-23

    To support the safety analyses required for the conversion of the Belgian Reactor 2 (BR2) from highly-enriched uranium (HEU) to low-enriched uranium (LEU) fuel, the simulation of a number of loss-of-flow tests, with or without loss of pressure, has been undertaken. These tests were performed at BR2 in 1963 and used instrumented fuel assemblies (FAs) with thermocouples (TC) imbedded in the cladding as well as probes to measure the FAs power on the basis of their coolant temperature rise. The availability of experimental data for these tests offers an opportunity to better establish the credibility of the RELAP5-3D model and methodology used in the conversion analysis. In order to support the HEU to LEU conversion safety analyses of the BR2 reactor, RELAP simulations of a number of loss-of-flow/loss-of-pressure tests have been undertaken. Preliminary analyses showed that the conservative power distributions used historically in the BR2 RELAP model resulted in a significant overestimation of the peak cladding temperature during the transient. Therefore, it was concluded that better estimates of the steady-state and decay power distributions were needed to accurately predict the cladding temperatures measured during the tests and establish the credibility of the RELAP model and methodology. The new approach ('best estimate' methodology) uses the MCNP5, ORIGEN-2 and BERYL codes to obtain steady-state and decay power distributions for the BR2 core during the tests A/400/1, C/600/3 and F/400/1. This methodology can be easily extended to simulate any BR2 core configuration. Comparisons with measured peak cladding temperatures showed a much better agreement when power distributions obtained with the new methodology are used.

  7. Loss of putzig Activity Results in Apoptosis during Wing Imaginal Development in Drosophila

    PubMed Central

    Zimmermann, Mirjam; Kugler, Sabrina J.; Schulz, Adriana; Nagel, Anja C.

    2015-01-01

    The Drosophila gene putzig (pzg) encodes a nuclear protein that is an integral component of the Trf2/Dref complex involved in the transcription of proliferation-related genes. Moreover, Pzg is found in a complex together with the nucleosome remodeling factor NURF, where it promotes Notch target gene activation. Here we show that downregulation of pzg activity in the developing wing imaginal discs induces an apoptotic response, accompanied by the induction of the pro-apoptotic gene reaper, repression of Drosophila inhibitor of apoptosis protein accumulation and the activation of the caspases Drice, Caspase3 and Dcp1. As a further consequence ‘Apoptosis induced Proliferation’ (AiP) and ‘Apoptosis induced Apoptosis’ (AiA) are triggered. As expected, the activity of the stress kinase Jun N-terminal kinase (JNK), proposed to mediate both processes, is ectopically induced in response to pzg loss. In addition, the expression of the mitogen wingless (wg) but not of decapentaplegic (dpp) is observed. We present evidence that downregulation of Notch activates Dcp1 caspase and JNK signaling, however, neither induces ectopic wg nor dpp expression. In contrast, the consequences of Dref-RNAi were largely indistinguishable from pzg-RNAi with regard to apoptosis induction. Moreover, overexpression of Dref ameliorated the downregulation of pzg compatible with the notion that the two are required together to maintain cell and tissue homeostasis in Drosophila. PMID:25894556

  8. Tachyphylaxis to PACAP-27 after inhibition of NO synthesis: a loss of adenylate cyclase activation

    NASA Technical Reports Server (NTRS)

    Whalen, E. J.; Johnson, A. K.; Lewis, S. J.

    1999-01-01

    The vasodilator effects of pituitary adenylate cyclase activating polypeptide (PACAP-27) are subject to tachyphylaxis in rats treated with the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). This study examined whether this tachyphylaxis is due to the loss of vasodilator potency of cAMP generated by activation of the G(s) protein-coupled PACAP receptors. Five successive treatments with PACAP-27 (2 nmol/kg iv) produced pronounced vasodilator responses in saline-treated rats that were not subject to tachyphylaxis. The first injection of PACAP-27 (2 nmol/kg iv) in L-NAME (50 micromol/kg iv)-treated rats produced vasodilator responses of similar magnitude to those in saline-treated rats, whereas four subsequent injections produced progressively and markedly smaller responses. The hemodynamic effects of the membrane-permeable cAMP analog 8-(4-chlorophenylthiol)-cAMP (8-CPT-cAMP; 5-15 micromol/kg iv) were similar in L-NAME-treated rats and in L-NAME-treated rats that had received the five injections of PACAP-27. In addition, five injections of 8-CPT-cAMP (10 micromol/kg iv) produced pronounced vasodilator responses in saline- and L-NAME-treated rats that were not subject to the development of tachyphylaxis. These results suggest that a loss of biological potency of cAMP is not responsible for tachyphylaxis to PACAP-27 in L-NAME-treated rats. This tachyphylaxis may be due to the inability of the G(s) protein-coupled PACAP receptor to activate adenylate cyclase.

  9. Noise-Induced Loss of Hair Cells and Cochlear Synaptopathy Are Mediated by the Activation of AMPK

    PubMed Central

    Hill, Kayla; Yuan, Hu; Wang, Xianren

    2016-01-01

    Noise-induced hearing loss (NIHL) is a major unresolved public health problem. Here, we investigate pathomechanisms of sensory hair cell death and suggest a novel target for protective intervention. Cellular survival depends upon maintenance of energy homeostasis, largely by AMP-activated protein kinase (AMPK). In response to a noise exposure in CBA/J mice, the levels of phosphorylated AMPKα increased in hair cells in a noise intensity-dependent manner. Inhibition of AMPK via siRNA or the pharmacological inhibitor compound C attenuated noise-induced loss of outer hair cells (OHCs) and synaptic ribbons, and preserved auditory function. Additionally, noise exposure increased the activity of the upstream AMPK kinase liver kinase B1 (LKB1) in cochlear tissues. The inhibition of LKB1 by siRNA attenuated the noise-increased phosphorylation of AMPKα in OHCs, reduced the loss of inner hair cell synaptic ribbons and OHCs, and protected against NIHL. These results indicate that noise exposure induces hair cell death and synaptopathy by activating AMPK via LKB1-mediated pathways. Targeting these pathways may provide a novel route to prevent NIHL. SIGNIFICANCE STATEMENT Our results demonstrate for the first time that the activation of AMP-activated protein kinase (AMPK) α in sensory hair cells is noise intensity dependent and contributes to noise-induced hearing loss by mediating the loss of inner hair cell synaptic ribbons and outer hair cells. Noise induces the phosphorylation of AMPKα1 by liver kinase B1 (LKB1), triggered by changes in intracellular ATP levels. The inhibition of AMPK activation by silencing AMPK or LKB1, or with the pharmacological inhibitor compound C, reduced outer hair cell and synaptic ribbon loss as well as noise-induced hearing loss. This study provides new insights into mechanisms of noise-induced hearing loss and suggests novel interventions for the prevention of the loss of sensory hair cells and cochlear synaptopathy. PMID:27413159

  10. Resonance in fast-wave amplitude in the periphery of cylindrical plasmas and application to edge losses of wave heating power in tokamaks

    SciTech Connect

    Perkins, R. J.; Hosea, J. C.; Bertelli, N.; Taylor, G.; Wilson, J. R.

    2016-07-01

    Heating magnetically confined plasmas using waves in the ion-cyclotron range of frequencies typically requires coupling these waves over a steep density gradient. Furthermore, this process has produced an unexpected and deleterious phenomenon on the National Spherical Torus eXperiment (NSTX): a prompt loss of wave power along magnetic field lines in front of the antenna to the divertor. Understanding this loss may be key to achieving effective heating and expanding the operational space of NSTX-Upgrade. Here, we propose that a new type of mode, which conducts a significant fraction of the total wave power in the low-density peripheral plasma, is driving these losses. We demonstrate the existence of such modes, which are distinct from surface modes and coaxial modes, in a cylindrical cold-plasma model when a half wavelength structure fits into the region outside the core plasma. The latter condition generalizes the previous hypothesis regarding the occurence of the edge losses and may explain why full-wave simulations predict these losses in some cases but not others. If valid, this condition implies that outer gap control is a potential strategy for mitigating the losses in NSTX-Upgrade in addition to raising the magnetic field or influencing the edge density.

  11. Resonance in fast-wave amplitude in the periphery of cylindrical plasmas and application to edge losses of wave heating power in tokamaks

    DOE PAGES

    Perkins, R. J.; Hosea, J. C.; Bertelli, N.; ...

    2016-07-01

    Heating magnetically confined plasmas using waves in the ion-cyclotron range of frequencies typically requires coupling these waves over a steep density gradient. Furthermore, this process has produced an unexpected and deleterious phenomenon on the National Spherical Torus eXperiment (NSTX): a prompt loss of wave power along magnetic field lines in front of the antenna to the divertor. Understanding this loss may be key to achieving effective heating and expanding the operational space of NSTX-Upgrade. Here, we propose that a new type of mode, which conducts a significant fraction of the total wave power in the low-density peripheral plasma, is drivingmore » these losses. We demonstrate the existence of such modes, which are distinct from surface modes and coaxial modes, in a cylindrical cold-plasma model when a half wavelength structure fits into the region outside the core plasma. The latter condition generalizes the previous hypothesis regarding the occurence of the edge losses and may explain why full-wave simulations predict these losses in some cases but not others. If valid, this condition implies that outer gap control is a potential strategy for mitigating the losses in NSTX-Upgrade in addition to raising the magnetic field or influencing the edge density.« less

  12. Daily energy expenditure, physical activity, and weight loss in Parkinson's disease patients.

    PubMed

    Delikanaki-Skaribas, Evangelia; Trail, Marilyn; Wong, William Wai-Lun; Lai, Eugene C

    2009-04-15

    Patients with Parkinson's disease (PD) commonly exhibit weight loss (WL) which investigators attribute to various factors, including elevated energy expenditure. We tested the hypothesis that daily energy expenditure (DEE) and its components, resting energy expenditure (REE) and physical activity (PA) energy expenditure (PAEE), are elevated in WL compared with weight stable (WS) PD patients. We measured DEE in 10 PD WL patients and 10 PD WS patients using doubly labeled water (DLW). PAEE was estimated with DLW, activity monitors, and activity questionnaires. REE was measured with indirect calorimetry. We evaluated energy intake (EI) with a patient's 3-day food diary. Data was assessed employing SPSS, Spearman correlation coefficients, and Bland and Altman plots. There was no difference in DEE between the WL and WS groups measured with DLW. There were no differences in REE and EI between groups. DEE (r = 0.548, P < 0.05) and PAEE (r = 0.563, P < 0.01) are related with caloric intake. The WL group had higher PA than the WS group (P < 0.042) only when measured with wrist activity monitors. Results suggest that WL in PD patients cannot be fully explained by an increase in DEE. Large longitudinal studies to examine multiple relationships between variables might provide us with a better understanding of WL among PD patients.

  13. Notch1 Activation or Loss Promotes HPV-Induced Oral Tumorigenesis.

    PubMed

    Zhong, Rong; Bao, Riyue; Faber, Pieter W; Bindokas, Vytautas P; Bechill, John; Lingen, Mark W; Spiotto, Michael T

    2015-09-15

    Viral oncogene expression is insufficient for neoplastic transformation of human cells, so human papillomavirus (HPV)-associated cancers will also rely upon mutations in cellular oncogenes and tumor suppressors. However, it has been difficult so far to distinguish incidental mutations without phenotypic impact from causal mutations that drive the development of HPV-associated cancers. In this study, we addressed this issue by conducting a functional screen for genes that facilitate the formation of HPV E6/E7-induced squamous cell cancers in mice using a transposon-mediated insertional mutagenesis protocol. Overall, we identified 39 candidate driver genes, including Notch1, which unexpectedly was scored by gain- or loss-of-function mutations that were capable of promoting squamous cell carcinogenesis. Autochthonous HPV-positive oral tumors possessing an activated Notch1 allele exhibited high rates of cell proliferation and tumor growth. Conversely, Notch1 loss could accelerate the growth of invasive tumors in a manner associated with increased expression of matrix metalloproteinases and other proinvasive genes. HPV oncogenes clearly cooperated with loss of Notch1, insofar as its haploinsufficiency accelerated tumor growth only in HPV-positive tumors. In clinical specimens of various human cancers, there was a consistent pattern of NOTCH1 expression that correlated with invasive character, in support of our observations in mice. Although Notch1 acts as a tumor suppressor in mouse skin, we found that oncogenes enabling any perturbation in Notch1 expression promoted tumor growth, albeit via distinct pathways. Our findings suggest caution in interpreting the meaning of putative driver gene mutations in cancer, and therefore therapeutic efforts to target them, given the significant contextual differences in which such mutations may arise, including in virus-associated tumors.

  14. Temperature and water loss affect ADH activity and gene expression in grape berry during postharvest dehydration.

    PubMed

    Cirilli, Marco; Bellincontro, Andrea; De Santis, Diana; Botondi, Rinaldo; Colao, Maria Chiara; Muleo, Rosario; Mencarelli, Fabio

    2012-05-01

    Clusters of Aleatico wine grape were picked at 18°Brix and placed at 10, 20, or 30°C, 45% relative humidity (RH) and 1.5m/s of air flow to dehydrate the berries up to 40% of loss of initial fresh weight. Sampling was done at 0%, 10%, 20%, 30%, and 40% weight loss (wl). ADH (alcohol dehydrogenase) gene expression, enzyme activity, and related metabolites were analysed. At 10°C, acetaldehyde increased rapidly and then declined, while ethanol continued to rise. At 20°C, acetaldehyde and ethanol increased significantly with the same pattern and declined at 40%wl. At 30°C, acetaldehyde did not increase but ethanol increased rapidly already at 10%wl. At the latter temperature, a significant increase in acetic acid and ethyl acetate occurred, while at 10°C their values were low. At 30°C, the ADH activity (ethanol to acetaldehyde direction), increased rapidly but acetaldehyde did not rise because of its oxidation to acetic acid, which increased together with ethyl acetate. At 10°C, the ADH activity increased at 20%wl and continued to rise even at 40%wl, meaning that ethanol oxidation was delayed. At 20°C, the behaviour was intermediate to the other temperatures. The relative expression of the VvAdh2 gene was the highest at 10°C already at 10%wl in a synchrony with the ADH activity, indicating a rapid response likely due to low temperature. The expression subsequently declined. At 20 and 30°C, the expression was lower and increased slightly during dehydration in combination with the ADH activity. This imbalance between gene expression and ADH activity at 10°C, as well as the unexpected expression of the carotenoid cleavage dioxygenase 1 (CCD1) gene, opens the discussion on the stress sensitivity and transcription event during postharvest dehydration, and the importance of carefully monitoring temperature during dehydration.

  15. 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.

  16. 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.

  17. Adaptive Current Control Method for Hybrid Active Power Filter

    NASA Astrophysics Data System (ADS)

    Chau, Minh Thuyen

    2016-09-01

    This paper proposes an adaptive current control method for Hybrid Active Power Filter (HAPF). It consists of a fuzzy-neural controller, identification and prediction model and cost function. The fuzzy-neural controller parameters are adjusted according to the cost function minimum criteria. For this reason, the proposed control method has a capability on-line control clings to variation of the load harmonic currents. Compared to the single fuzzy logic control method, the proposed control method shows the advantages of better dynamic response, compensation error in steady-state is smaller, able to online control is better and harmonics cancelling is more effective. Simulation and experimental results have demonstrated the effectiveness of the proposed control method.

  18. Retinal Structures and Visual Cortex Activity are Impaired Prior to Clinical Vision Loss in Glaucoma

    PubMed Central

    Murphy, Matthew C.; Conner, Ian P.; Teng, Cindy Y.; Lawrence, Jesse D.; Safiullah, Zaid; Wang, Bo; Bilonick, Richard A.; Kim, Seong-Gi; Wollstein, Gadi; Schuman, Joel S.; Chan, Kevin C.

    2016-01-01

    Glaucoma is the second leading cause of blindness worldwide and its pathogenesis remains unclear. In this study, we measured the structure, metabolism and function of the visual system by optical coherence tomography and multi-modal magnetic resonance imaging in healthy subjects and glaucoma patients with different degrees of vision loss. We found that inner retinal layer thinning, optic nerve cupping and reduced visual cortex activity occurred before patients showed visual field impairment. The primary visual cortex also exhibited more severe functional deficits than higher-order visual brain areas in glaucoma. Within the visual cortex, choline metabolism was perturbed along with increasing disease severity in the eye, optic radiation and visual field. In summary, this study showed evidence that glaucoma deterioration is already present in the eye and the brain before substantial vision loss can be detected clinically using current testing methods. In addition, cortical cholinergic abnormalities are involved during trans-neuronal degeneration and can be detected non-invasively in glaucoma. The current results can be of impact for identifying early glaucoma mechanisms, detecting and monitoring pathophysiological events and eye-brain-behavior relationships, and guiding vision preservation strategies in the visual system, which may help reduce the burden of this irreversible but preventable neurodegenerative disease. PMID:27510406

  19. Neutron activation analysis of aerosols in conjunction with a loss-free counter

    SciTech Connect

    Biegalski, S.R.; Heydorn, K.; Landsberger, S.

    1994-12-31

    As part of an ongoing Arctic environmental research program, aerosol samples were collected on cellulose acetate filters at Station Nord in Greenland by the National Environmental Research Institute of Denmark. These samples were then given to the Riso National Laboratory in Denmark for evaluation by neutron activation analysis (NAA). Even though loss-free counters have been available for some with good results, little information has appeared in the literature in its use for actual samples. At Riso National Laboratory the samples were irradiated in the DR3 reactor and then counted on a GAMMA-X high-purity germanium (HPGe) counter with a Nuclear Data ND 599 loss-free counting (LFC) module. The aerosol filters were quite varied in their elemental depositions, and LFC was especially utilized to accommodate for the wide range of dead times encountered with the counting of short-lived isotopes. In some cases the fast decay of isotopes over the count along with pulse pileup problems would have made the use of other dead-time correction methods unreliable.

  20. Loss of diversity in wood-inhabiting fungal communities affects decomposition activity in Norway spruce wood

    PubMed Central

    Valentín, Lara; Rajala, Tiina; Peltoniemi, Mikko; Heinonsalo, Jussi; Pennanen, Taina; Mäkipää, Raisa

    2014-01-01

    Hundreds of wood-inhabiting fungal species are now threatened, principally due to a lack of dead wood in intensively managed forests, but the consequences of reduced fungal diversity on ecosystem functioning are not known. Several experiments have shown that primary productivity is negatively affected by a loss of species, but the effects of microbial diversity on decomposition are less studied. We studied the relationship between fungal diversity and the in vitro decomposition rate of slightly, moderately and heavily decayed Picea abies wood with indigenous fungal communities that were diluted to examine the influence of diversity. Respiration rate, wood-degrading hydrolytic enzymes and fungal community structure were assessed during a 16-week incubation. The number of observed OTUs in DGGE was used as a measure of fungal diversity. Respiration rate increased between early- and late-decay stages. Reduced fungal diversity was associated with lower respiration rates during intermediate stages of decay, but no effects were detected at later stages. The activity of hydrolytic enzymes varied among decay stages and fungal dilutions. Our results suggest that functioning of highly diverse communities of the late-decay stage were more resistant to the loss of diversity than less diverse communities of early decomposers. This indicates the accumulation of functional redundancy during the succession of the fungal community in decomposing substrates. PMID:24904544

  1. Activated Immune Response in an Inherited Leukodystrophy Disease Caused by the Loss of Oligodendrocyte Gap Junctions

    PubMed Central

    Wasseff, Sameh K.; Scherer, Steven S.

    2015-01-01

    Oligodendrocyte:oligodendrocyte (O:O) gap junction (GJ) coupling is a widespread and essential feature of the CNS, and is mediated by connexin47 (Cx47) and Cx32. Loss of function mutations affecting Cx47 results in a severe leukodystrophy, Pelizeus-Merzbacher-like disease (also known as Hypomyelinating Leukodystrophy 2), which can be reproduced in mice lacking both Cx47 and Cx32. Here we report the gene expression profile of the cerebellum – an affected brain region – in mice lacking both Cx47 and Cx32. Of the 43,174 mRNA probes examined, we find decreased expression of 23 probes (corresponding to 23 genes) and increased expression of 545 probes (corresponding to 348 genes). Many of the genes with reduced expression map to oligodendrocytes, and two of them (Fa2h and Ugt8a) are involved in the synthesis of myelin lipids. Many of the genes with increased expression map to microglia and lymphocytes, and to leukotriene/prostaglandin synthesis and chemokine/cytokine pathways. In accord, immunostaining showed activated microglia and astrocytes, as well as T- and B-cells in the cerebella of mutant mice. Thus, in addition to the loss of GJ coupling, there is a prominent immune response in mice lacking both Cx47 and Cx32. PMID:26051537

  2. Irreversible loss of a subpopulation of cortical interneurons in the absence of glutamatergic network activity.

    PubMed

    de Lima, Ana Dolabela; Opitz, Thoralf; Voigt, Thomas

    2004-06-01

    In the cerebral cortex of mammals, gamma-aminobutyric acid (GABA)ergic neurons represent 15-25% of all neurons, depending on the species and area being examined. Because converging evidence suggests that activity may play an important role in the neuritic maturation and synaptic function of GABAergic neurons, it is feasible that activity plays a role in the regulation of the proportion of GABAergic neurons. Here we provide direct evidence that early in cortical development activity blockade may deplete the network of a subpopulation of GABA immunoreactive neurons characterized by their small size and late generation in vitro. In a period of time coinciding with the emergence of synchronous network activity, the survival and morphological differentiation of GABAergic neurons was influenced by long-term blockade of synaptic activity. While GABA(A) receptor antagonists had a minor promoting effect on interneuronal survival during the second week in vitro, antagonists of ionotropic glutamate receptors strongly impaired survival and differentiation of immature GABAergic interneurons. Interneuronal loss was more severe when N-methyl-D-aspartate receptors were blocked than after blockade of alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid (AMPA)/kainate receptors. The decrease in the density of GABAergic neurons was irreversible, but could be prevented by the simultaneous addition of brain-derived neurotrophic factor (BDNF). These results suggest that there is a narrow time window during neocortical development when glutamatergic activity, and specially NMDA receptor stimulation, is crucial to assure survival and maturation of a subpopulation of late developing GABAergic interneurons.

  3. Determining the Nature and Origin of Mass Loss from Active Asteroid P/2013 R3

    NASA Astrophysics Data System (ADS)

    Jewitt, David

    2014-10-01

    We propose a program of WFC3 images of the active asteroid P/2013 R3 in order to determine the nature and origin of mass loss from this object. R3 has a unique, multiple nucleus structure in which the components are measured to separate at sub-meter per second velocities. It is best explained as a rotational breakup (presumably resulting from the YORP torque). We will obtain images over a wide time base in Cycle 22 in order to determine the orbits of the fragments and we will obtain time-series, high resolution photometry in order to measure their rotations. Rotational breakup and rotational mass-shedding are suspected to be the main mechanisms of destruction for sub-kilometer asteroids. Neither has been observed before but, between P/2013 R3 and P/2013 P5 (subject of another proposal) we have the first, potentially ground-breaking opportunities to observe both.

  4. Nonreciprocal nonlinear wave scattering by loss-compensated active hyperbolic structures

    PubMed Central

    Shramkova, O. V.; Tsironis, G. P.

    2017-01-01

    The combinatorial frequency generation (CFG) in active periodic semiconductor-dielectric structures has been explored through illumination by a pair of pump waves with dissimilar frequencies and incidence angles. We study the influence of gain on linear refraction properties of the stack and on the efficiency of the mixing processes by the system with the resistive character of nonlinearity. We demonstrate that the introduction of gain dielectric material inside the stack not only compensates for losses caused by the collisions of the electrons in semiconductor media but also improves the efficiency of the CFG. We show that in systems with weak asymmetry of linear response we can get significant nonreciprocity of nonlinear interaction. PMID:28225004

  5. Complement activation and choriocapillaris loss in early AMD: Implications for pathophysiology and therapy

    PubMed Central

    Whitmore, S.Scott; Sohn, Elliott H.; Chirco, Kathleen R.; Drack, Arlene V.; Stone, Edwin M.; Tucker, Budd A.; Mullins, Robert F.

    2015-01-01

    Age-related macular degeneration (AMD) is a common and devastating disease that can result in severe visual dysfunction. Over the last decade, great progress has been made in identifying genetic variants that contribute to AMD, many of which lie in genes involved in the complement cascade. In this review we discuss the significance of complement activation in AMD, particularly with respect to the formation of the membrane attack complex in the aging choriocapillaris. We review the clinical, histological and biochemical data that indicate that vascular loss in the choroid occurs very early in the pathogenesis of AMD, and discuss the potential impact of vascular dropout on the retinal pigment epithelium, Bruch's membrane and the photoreceptor cells. Finally, we present a hypothesis for the pathogenesis of early AMD and consider the implications of this model on the development of new therapies. PMID:25486088

  6. Transient Control of Synchronous Machine Active and Reactive Power in Micro-grid Power Systems

    NASA Astrophysics Data System (ADS)

    Weber, Luke G.

    There are two main topics associated with this dissertation. The first is to investigate phase-to-neutral fault current magnitude occurring in generators with multiple zero-sequence current sources. The second is to design, model, and tune a linear control system for operating a micro-grid in the event of a separation from the electric power system. In the former case, detailed generator, AC8B excitation system, and four-wire electric power system models are constructed. Where available, manufacturers data is used to validate the generator and exciter models. A gain-delay with frequency droop control is used to model an internal combustion engine and governor. The four wire system is connected through a transformer impedance to an infinite bus. Phase-to-neutral faults are imposed on the system, and fault magnitudes analyzed against three-phase faults to gauge their severity. In the latter case, a balanced three-phase system is assumed. The model structure from the former case - but using data for a different generator - is incorporated with a model for an energy storage device and a net load model to form a micro-grid. The primary control model for the energy storage device has a high level of detail, as does the energy storage device plant model in describing the LC filter and transformer. A gain-delay battery and inverter model is used at the front end. The net load model is intended to be the difference between renewable energy sources and load within a micro-grid system that has separated from the grid. Given the variability of both renewable generation and load, frequency and voltage stability are not guaranteed. This work is an attempt to model components of a proposed micro-grid system at the University of Wisconsin Milwaukee, and design, model, and tune a linear control system for operation in the event of a separation from the electric power system. The control module is responsible for management of frequency and active power, and voltage and reactive

  7. Rhabdomyolysis-Associated Mutations in Human LPIN1 Lead to Loss of Phosphatidic Acid Phosphohydrolase Activity.

    PubMed

    Schweitzer, George G; Collier, Sara L; Chen, Zhouji; Eaton, James M; Connolly, Anne M; Bucelli, Robert C; Pestronk, Alan; Harris, Thurl E; Finck, Brian N

    2015-01-01

    Rhabdomyolysis is an acute syndrome due to extensive injury of skeletal muscle. Recurrent rhabdomyolysis is often caused by inborn errors in intermediary metabolism, and recent work has suggested that mutations in the human gene encoding lipin 1 (LPIN1) may be a common cause of recurrent rhabdomyolysis in children. Lipin 1 dephosphorylates phosphatidic acid to form diacylglycerol (phosphatidic acid phosphohydrolase; PAP) and acts as a transcriptional regulatory protein to control metabolic gene expression. Herein, a 3-year-old boy with severe recurrent rhabdomyolysis was determined to be a compound heterozygote for a novel c.1904T>C (p.Leu635Pro) substitution and a previously reported genomic deletion of exons 18-19 (E766-S838_del) in LPIN1. Western blotting with patient muscle biopsy lysates demonstrated a marked reduction in lipin 1 protein, while immunohistochemical staining for lipin 1 showed abnormal subcellular localization. We cloned cDNAs to express recombinant lipin 1 proteins harboring pathogenic mutations and showed that the E766-S838_del allele was not expressed at the RNA or protein level. Lipin 1 p.Leu635Pro was expressed, but the protein was less stable, was aggregated in the cytosol, and was targeted for proteosomal degradation. Another pathogenic single amino acid substitution, lipin 1 p.Arg725His, was well expressed and retained its transcriptional regulatory function. However, both p.Leu635Pro and p.Arg725His proteins were found to be deficient in PAP activity. Kinetic analyses demonstrated a loss of catalysis rather than diminished substrate binding. These data suggest that loss of lipin 1-mediated PAP activity may be involved in the pathogenesis of rhabdomyolysis in lipin 1 deficiency.

  8. Enhanced ozone loss by active inorganic bromine chemistry in the tropical troposphere

    NASA Astrophysics Data System (ADS)

    Le Breton, Michael; Bannan, Thomas J.; Shallcross, Dudley E.; Khan, M. Anwar; Evans, Mathew J.; Lee, James; Lidster, Richard; Andrews, Stephen; Carpenter, Lucy J.; Schmidt, Johan; Jacob, Daniel; Harris, Neil R. P.; Bauguitte, Stephane; Gallagher, Martin; Bacak, Asan; Leather, Kimberley E.; Percival, Carl J.

    2017-04-01

    Bromine chemistry, particularly in the tropics, has been suggested to play an important role in tropospheric ozone loss although a lack of measurements of active bromine species impedes a quantitative understanding of its impacts. Recent modelling and measurements of bromine monoxide (BrO) by Wang et al. (2015) have shown current models under predict BrO concentrations over the Pacific Ocean and allude to a missing source of BrO. Here, we present the first simultaneous aircraft measurements of atmospheric bromine monoxide, BrO (a radical that along with atomic Br catalytically destroys ozone) and the inorganic Br precursor compounds HOBr, BrCl and Br2 over the Western Pacific Ocean from 0.5 to 7 km. The presence of 0.17-1.64 pptv BrO and 3.6-8 pptv total inorganic Br from these four species throughout the troposphere causes 10-20% of total ozone loss, and confirms the importance of bromine chemistry in the tropical troposphere; contributing to a 6 ppb decrease in ozone levels due to halogen chemistry. Observations are compared with a global chemical transport model and find that the observed high levels of BrO, BrCl and HOBr can be reconciled by active multiphase oxidation of halide (Br- and Cl-) by HOBr and ozone in cloud droplets and aerosols. Measurements indicate that 99% of the instantaneous free Br in the troposphere up to 8 km originates from inorganic halogen photolysis rather than from photolysis of organobromine species.

  9. Smart conjugated polymer nanocarrier for healthy weight loss by negative feedback regulation of lipase activity

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Lei; Zhu, Sha; Zhang, Lei; Feng, Pei-Jian; Yao, Xi-Kuang; Qian, Cheng-Gen; Zhang, Can; Jiang, Xi-Qun; Shen, Qun-Dong

    2016-02-01

    Healthy weight loss represents a real challenge when obesity is increasing in prevalence. Herein, we report a conjugated polymer nanocarrier for smart deactivation of lipase and thus balancing calorie intake. After oral administration, the nanocarrier is sensitive to lipase in the digestive tract and releases orlistat, which deactivates the enzyme and inhibits fat digestion. It also creates negative feedback to control the release of itself. The nanocarrier smartly regulates activity of the lipase cyclically varied between high and low levels. In spite of high fat diet intervention, obese mice receiving a single dose of the nanocarrier lose weight over eight days, whereas a control group continues the tendency to gain weight. Daily intragastric administration of the nanocarrier leads to lower weight of livers or fat pads, smaller adipocyte size, and lower total cholesterol level than that of the control group. Near-infrared fluorescence of the nanocarrier reveals its biodistribution.Healthy weight loss represents a real challenge when obesity is increasing in prevalence. Herein, we report a conjugated polymer nanocarrier for smart deactivation of lipase and thus balancing calorie intake. After oral administration, the nanocarrier is sensitive to lipase in the digestive tract and releases orlistat, which deactivates the enzyme and inhibits fat digestion. It also creates negative feedback to control the release of itself. The nanocarrier smartly regulates activity of the lipase cyclically varied between high and low levels. In spite of high fat diet intervention, obese mice receiving a single dose of the nanocarrier lose weight over eight days, whereas a control group continues the tendency to gain weight. Daily intragastric administration of the nanocarrier leads to lower weight of livers or fat pads, smaller adipocyte size, and lower total cholesterol level than that of the control group. Near-infrared fluorescence of the nanocarrier reveals its biodistribution

  10. Loss of endothelial programmed cell death 10 activates glioblastoma cells and promotes tumor growth

    PubMed Central

    Zhu, Yuan; Zhao, Kai; Prinz, Anja; Keyvani, Kathy; Lambertz, Nicole; Kreitschmann-Andermahr, Ilonka; Lei, Ting; Sure, Ulrich

    2016-01-01

    Background Neo-angiogenesis is a hallmark of glioblastoma (GBM) and is sustained by autocrine and paracrine interactions between neoplastic and nonneoplastic cells. Programmed cell death 10 (PDCD10) is ubiquitously expressed in nearly all tissues and plays crucial roles in regulating angiogenesis and apoptosis. We recently discovered the absence of PDCD10 expression in the tumor vessels of GBM patients. This raised the hypothesis that loss of endothelial PDCD10 affected GBM cell phenotyping and tumor progression. Methods Endothelial PDCD10 was silenced by siRNA and lentiviral shRNA. The tumor cell phenotype was studied in direct and indirect co-culture of endothelial cells (ECs) with U87 or LN229. Angiogenic protein array was performed in the media of PDCD10-silenced ECs. Tumor angiogenesis and tumor growth were investigated in a human GBM xenograft mouse model. Results Endothelial silence of PDCD10 significantly stimulated tumor cell proliferation, migration, adhesion, and invasion and inhibited apoptosis in co-cultures. Stable knockdown of endothelial PDCD10 increased microvessel density and the formation of a functional vascular network, leading to a 4-fold larger tumor mass in mice. Intriguingly, endothelial deletion of PDCD10 increased (≥2-fold) the release of 20 of 55 tested proangiogenic factors including VEGF, which in turn activated Erk1/2 and Akt in GBM cells. Conclusions For the first time, we provide evidence that loss of endothelial PDCD10 activates GBM cells and promotes tumor growth, most likely via a paracrine mechanism. PDCD10 shows a tumor-suppressor-like function in the cross talk between ECs and tumor cells and is potentially implicated in GBM progression. PMID:26254477

  11. Loss of the cylindromatosis tumour suppressor inhibits apoptosis by activating NF-kappaB.

    PubMed

    Brummelkamp, Thijn R; Nijman, Sebastian M B; Dirac, Annette M G; Bernards, René

    2003-08-14

    Protein modification by the conjugation of ubiquitin moieties--ubiquitination--plays a major part in many biological processes, including cell cycle and apoptosis. The enzymes that mediate ubiquitin-conjugation have been well-studied, but much less is known about the ubiquitin-specific proteases that mediate de-ubiquitination of cellular substrates. To study this gene family, we designed a collection of RNA interference vectors to suppress 50 human de-ubiquitinating enzymes, and used these vectors to identify de-ubiquitinating enzymes in cancer-relevant pathways. We report here that inhibition of one of these enzymes, the familial cylindromatosis tumour suppressor gene (CYLD), having no known function, enhances activation of the transcription factor NF-kappaB. We show that CYLD binds to the NEMO (also known as IKKgamma) component of the IkappaB kinase (IKK) complex, and appears to regulate its activity through de-ubiquitination of TRAF2, as TRAF2 ubiquitination can be modulated by CYLD. Inhibition of CYLD increases resistance to apoptosis, suggesting a mechanism through which loss of CYLD contributes to oncogenesis. We show that this effect can be relieved by aspirin derivatives that inhibit NF-kappaB activity, which suggests a therapeutic intervention strategy to restore growth control in patients suffering from familial cylindromatosis.

  12. Swimming Activity Prevents the Unloading Induced Loss of Bone Mass, Architecture, and Strength in Rats

    PubMed Central

    Falcai, Maurício J.; Leoni, Graziela Bianchi; de Sousa Neto, Manoel Damião; Volpon, Jose B.

    2015-01-01

    We investigated whether swimming activity associated with a three-week period of hypoactivity could prevent the deleterious effects of disuse on the tibias of tail-suspended rats. Forty Wistar rats were divided into five groups: (HS) permanently hindlimb suspension rats; (HS + Swim) rats submitted to unloading interrupted by swimming exercise; (HS + WB) hindlimb suspension rats with interruption for regular weight bearing for the same length of time as the HS+Swim rats; (Control) control rats that were allowed regular cage activities; and (Control + Swim) control rats that underwent swimming exercise. At the end of the experiment, bone mineral density, bone strength, and trabecular quantification were analyzed. The hindlimb-suspended rats exhibited bone quality loss (significant decrease in BMD, bone strength, and deterioration of trabecular and cortical bone architecture; decrease in BV/TV, TbN, TbTh, ConnD, CtV, and CtTh; and increase in TbSp) when compared to control rats. In contrast, trained rats showed a significant increase of 43% in bone mass, 29% in bone strength, 58% in trabecular thickness, 85% in bone volume, 27% in trabeculae number, and 30% in cortical volume, when compared to the hindlimb-suspended rats. We conclude that swimming activity not only ameliorates but also fully prevents the deleterious effects on bone quality in osteopenic rats. PMID:26090414

  13. Energetic ion losses caused by magnetohydrodynamic activity resonant and non-resonant with energetic ions in Large Helical Device

    NASA Astrophysics Data System (ADS)

    Ogawa, Kunihiro; Isobe, Mitsutaka; Toi, Kazuo; Shimizu, Akihiro; Spong, Donald A.; Osakabe, Masaki; Yamamoto, Satoshi; the LHD Experiment Group

    2014-09-01

    Experiments to reveal energetic ion dynamics associated with magnetohydrodynamic activity are ongoing in the Large Helical Device (LHD). Interactions between beam-driven toroidal Alfvén eigenmodes (TAEs) and energetic ions have been investigated. Energetic ion losses induced by beam-driven burst TAEs have been observed using a scintillator-based lost fast-ion probe (SLIP) in neutral beam-heated high β plasmas. The loss flux of co-going beam ions increases as the TAE amplitude increases. In addition to this, the expulsion of beam ions associated with edge-localized modes (ELMs) has been also recognized in LHD. The SLIP has indicated that beam ions having co-going and barely co-going orbits are affected by ELMs. The relation between ELM amplitude and ELM-induced loss has a dispersed structure. To understand the energetic ion loss process, a numerical simulation based on an orbit-following model, DELTA5D, that incorporates magnetic fluctuations is performed. The calculation result shows that energetic ions confined in the interior region are lost due to TAE instability, with a diffusive process characterizing their loss. For the ELM, energetic ions existing near the confinement/loss boundary are lost through a convective process. We found that the ELM-induced loss flux measured by SLIP changes with the ELM phase. This relation between the ELM amplitude and measured ELM-induced loss results in a more dispersed loss structure.

  14. High peak power, 28 ns Q-switched Tm:LuAG laser at a 2 μm wavelength by dual-loss-modulation

    NASA Astrophysics Data System (ADS)

    Luan, Chao; Yang, Kejian; Zhao, Jia; Zhao, Shengzhi; Qiao, Wenchao; Li, Tao; Liu, Cheng; Chu, Hongwei; Qiao, Junpeng; Zheng, Lihe; Xu, Xiaodong; Xu, Jun

    2016-02-01

    By employing output couplers (OCs) with different transmissions T and GaAs saturable absorbers (SAs) with different modulation depth ΔR in a passively Q-switched Tm:LuAG laser at 2 μm, the optimal parameters of OCs and SAs for obtaining short pulse width and high peak power were investigated. By inserting an electro-optical modulator (EOM) into the optimized passively Q-switched Tm:LuAG laser (T  =  2%/ΔR  =  19%), a dual-loss-modulated Q-switched Tm:LuAG laser with an EOM and GaAs was realized. The experimental results show that the dual-loss-modulated Q-switched laser can generate a shorter pulse width and higher peak power than the single-loss-modulated case. At an incident pump power of 8.4 W, the shortest pulse width achieved was 28 ns and the highest peak power reached 74 kW.

  15. 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

  16. Food stress prompts dispersal behavior in apterous pea aphids: do activated aphids incur energy loss?

    PubMed

    Tabadkani, Seyed Mohammad; Ahsaei, Seyed Mohammad; Hosseininaveh, Vahid; Nozari, Jamasb

    2013-02-17

    The pea aphid, Acyrthosiphon pisum (Hem: Aphididae), has been repeatedly used as a model species in a wide range of biological studies including genetics, ecology, physiology, and behavior. When red pea aphids feed on low quality plants in crowded conditions, some individuals lose their color shade and become pale yellowish, while other individuals on the same host plants remain changeless. The pale aphids have been shown to walk significantly faster and migrate more frequently to neighboring plants compared to the original red ones. We hypothesized that the color change and higher activity of pale aphids are directly associated with their suboptimal nutritional status. We showed that the pale aphids have significantly lower wet and dry weights than red ones. Analyses of energy reserves in individual aphids revealed that the pale aphids suffer a significant loss in their lipid and soluble carbohydrate contents. Our results provide a strong link between host quality, body color, dispersal rate, and energy reserves of pea aphids. Apparently, utilization of energy reserves resulted from an imbalance in food sources received by the aphids stimulates them to walk more actively to find new hosts and restore their lost energy. This reversible shift enables aphids to quickly respond to deprived host plants much earlier than the appearance of winged morph and restore their original status when they find appropriate host.

  17. Plasminogen Activator Inhibitor-1 Is Involved in Streptozotocin-Induced Bone Loss in Female Mice

    PubMed Central

    Tamura, Yukinori; Kawao, Naoyuki; Okada, Kiyotaka; Yano, Masato; Okumoto, Katsumi; Matsuo, Osamu; Kaji, Hiroshi

    2013-01-01

    In diabetic patients, the risk of fracture is high because of impaired bone formation. However, the details of the mechanisms in the development of diabetic osteoporosis remain unclear. In the current study, we investigated the role of plasminogen activator inhibitor (PAI)-1 in the pathogenesis of type 1 diabetic osteoporosis by using PAI-1–deficient mice. Quantitative computed tomography analysis showed that PAI-1 deficiency protected against streptozotocin-induced bone loss in female mice but not in male mice. PAI-1 deficiency blunted the changes in the levels of Runx2, osterix, and alkaline phosphatase in tibia as well as serum osteocalcin levels suppressed by the diabetic state in female mice only. Furthermore, the osteoclast levels in tibia, suppressed in diabetes, were also blunted by PAI-1 deficiency in female mice. Streptozotocin markedly elevated the levels of PAI-1 mRNA in liver in female mice only. In vitro study demonstrated that treatment with active PAI-1 suppressed the levels of osteogenic genes and mineralization in primary osteoblasts from female mouse calvaria. In conclusion, the current study indicates that PAI-1 is involved in the pathogenesis of type 1 diabetic osteoporosis in females. The expression of PAI-1 in the liver and the sensitivity of bone cells to PAI-1 may be an underlying mechanism. PMID:23715621

  18. Evolutionary Loss of Activity in De-Ubiquitylating Enzymes of the OTU Family

    PubMed Central

    Louis, Marcell; Hofmann, Kay; Broemer, Meike

    2015-01-01

    Understanding function and specificity of de-ubiquitylating enzymes (DUBs) is a major goal of current research, since DUBs are key regulators of ubiquitylation events and have been shown to be mutated in human diseases. Most DUBs are cysteine proteases, relying on a catalytic triad of cysteine, histidine and aspartate to cleave the isopeptide bond between two ubiquitin units in a poly-ubiquitin chain. We have discovered that the two Drosophila melanogaster homologues of human OTUD4, CG3251 and Otu, contain a serine instead of a cysteine in the catalytic OTU (ovarian tumor) domain. DUBs that are serine proteases instead of cysteine- or metallo-proteases have not been described. In line with this, neither CG3251 nor Otu protein were active to cleave ubiquitin chains. Re-introduction of a cysteine in the catalytic center did not render the enzymes active, indicating that further critical features for ubiquitin binding or cleavage have been lost in these proteins. Sequence analysis of OTUD4 homologues from various other species showed that within this OTU subfamily, loss of the catalytic cysteine has occurred frequently in presumably independent events, as well as gene duplications or triplications, suggesting DUB-independent functions of OTUD4 proteins. Using an in vivo RNAi approach, we show that CG3251 might function in the regulation of Inhibitor of Apoptosis (IAP)-antagonist-induced apoptosis, presumably in a DUB-independent manner. PMID:26588485

  19. FUV Spectra of Evolved Late-K and M Stars: Mass Loss Revisited and Stellar Activity

    NASA Technical Reports Server (NTRS)

    Harper, Graham M.

    2002-01-01

    This is the final report for the FUSE Cycle 1 program A100: FUV Spectra of Evolved Late-K and M Stars: Mass Loss revisited and Stellar Activity. Targets alpha TrA (K3 II) and gamma Cru (M3 III) were originally assigned 25 ksec each, to be observed in the medium aperture. Once the in-flight performance and telescope alignment problems were known, the observations were reprogrammed to optimized the scientific return of the program. Alpha TrA was scheduled for 25 ksec observations in both the medium and large apertures. The principle aim of this program was to measure the stellar FUV line and continuum emission, in order to estimate the photoionization radiation field and to determine the level of stellar activity through the fluxes in the collisionally excited high temperature diagnostics: C III 977Angstroms and O VI 1032,1038Angstrom doublet. The medium aperture observations were obtained successfully while the large aperture observations were thought by Johns Hopkins University (JHU)to be lost to satellite problems. There was insufficient signal-to- noise in the medium aperture short wavelength Sic channels to do quantitative science.

  20. Loss of rostral brainstem cholinergic activity results in decreased ultrasonic vocalization behavior and altered sensorimotor gating.

    PubMed

    Machold, Robert P

    2013-11-01

    The parabigeminal (PBG), pedunculopontine (PPTg), and laterodorsal tegmental (LDTg) nuclei located in the rostral brainstem are the primary sources of the neurotransmitter acetylcholine (ACh) for the midbrain and thalamus, and as part of the ascending reticular activating system, these cholinergic signaling pathways regulate mouse behavioral responses to sensory stimuli. Here, I report that mice harboring a conditional deletion of ACh synthesis specifically within these nuclei (ChAT(En1 KO)) exhibit decreased ultrasonic vocalizations both as pups and adults, consistent with their previously reported hypoactivity when exploring the novel environment of the open field arena. Furthermore, in prepulse inhibition (PPI) tests, ChAT(En1 KO) animals exhibited increased sensorimotor gating in comparison to control littermates. These data suggest that ACh signaling arising from the rostral brainstem modulates animal behavior in part by tuning the levels of sensorimotor gating. Thus, the net effect of this cholinergic activity is to increase sensitivity to environmental stimuli, and loss of this pathway contributes to the hypoactivity in these mutants by raising the sensory threshold for eliciting exploratory behaviors.

  1. XUV-driven mass loss from extrasolar giant planets orbiting active stars

    NASA Astrophysics Data System (ADS)

    Chadney, J. M.; Galand, M.; Unruh, Y. C.; Koskinen, T. T.; Sanz-Forcada, J.

    2015-04-01

    Upper atmospheres of Hot Jupiters are subject to extreme radiation conditions that can result in rapid atmospheric escape. The composition and structure of the upper atmospheres of these planets are affected by the high-energy spectrum of the host star. This emission depends on stellar type and age, which are thus important factors in understanding the behaviour of exoplanetary atmospheres. In this study, we focus on Extrasolar Giant Planets (EPGs) orbiting K and M dwarf stars. XUV spectra for three different stars - ɛ Eridani, AD Leonis and AU Microscopii - are constructed using a coronal model. Neutral density and temperature profiles in the upper atmosphere of hypothetical EGPs orbiting these stars are then obtained from a fluid model, incorporating atmospheric chemistry and taking atmospheric escape into account. We find that a simple scaling based solely on the host star's X-ray emission gives large errors in mass loss rates from planetary atmospheres and so we have derived a new method to scale the EUV regions of the solar spectrum based upon stellar X-ray emission. This new method produces an outcome in terms of the planet's neutral upper atmosphere very similar to that obtained using a detailed coronal model of the host star. Our results indicate that in planets subjected to radiation from active stars, the transition from Jeans escape to a regime of hydrodynamic escape at the top of the atmosphere occurs at larger orbital distances than for planets around low activity stars (such as the Sun).

  2. Foraging Activity Pattern Is Shaped by Water Loss Rates in a Diurnal Desert Rodent.

    PubMed

    Levy, Ofir; Dayan, Tamar; Porter, Warren P; Kronfeld-Schor, Noga

    2016-08-01

    Although animals fine-tune their activity to avoid excess heat, we still lack a mechanistic understanding of such behaviors. As the global climate changes, such understanding is particularly important for projecting shifts in the activity patterns of populations and communities. We studied how foraging decisions vary with biotic and abiotic pressures. By tracking the foraging behavior of diurnal desert spiny mice in their natural habitat and estimating the energy and water costs and benefits of foraging, we asked how risk management and thermoregulatory requirements affect foraging decisions. We found that water requirements had the strongest effect on the observed foraging decisions. In their arid environment, mice often lose water while foraging for seeds and cease foraging even at high energetic returns when water loss is high. Mice also foraged more often when energy expenditure was high and for longer times under high seed densities and low predation risks. Gaining insight into both energy and water balance will be crucial to understanding the forces exerted by changing climatic conditions on animal energetics, behavior, and ecology.

  3. Model predictive direct power control for active power decoupled single-phase quasi-Z -source inverter

    SciTech Connect

    Liu, Yushan; Ge, Baoming; Abu-Rub, Haitham; Sun, Hexu; Peng, Fang Zheng; Xue, Yaosuo

    2016-06-14

    In this study, the active power filter (APF) that consists of a half-bridge leg and an ac capacitor is integrated in the single-phase quasi-Z-source inverter (qZSI) in this paper to avoid the second harmonic power flowing into the dc side. The capacitor of APF buffers the second harmonic power of the load, and the ac capacitor allows highly pulsating ac voltage, so that the capacitances of both dc and ac sides can be small. A model predictive direct power control (DPC) is further proposed to achieve the purpose of this newtopology through predicting the capacitor voltage of APF at each sampling period and ensuring the APF power to track the second harmonic power of single-phase qZSI. Simulation and experimental results verify the model predictive DPC for the APF-integrated single-phase qZSI.

  4. Model predictive direct power control for active power decoupled single-phase quasi-Z -source inverter

    DOE PAGES

    Liu, Yushan; Ge, Baoming; Abu-Rub, Haitham; ...

    2016-06-14

    In this study, the active power filter (APF) that consists of a half-bridge leg and an ac capacitor is integrated in the single-phase quasi-Z-source inverter (qZSI) in this paper to avoid the second harmonic power flowing into the dc side. The capacitor of APF buffers the second harmonic power of the load, and the ac capacitor allows highly pulsating ac voltage, so that the capacitances of both dc and ac sides can be small. A model predictive direct power control (DPC) is further proposed to achieve the purpose of this newtopology through predicting the capacitor voltage of APF at eachmore » sampling period and ensuring the APF power to track the second harmonic power of single-phase qZSI. Simulation and experimental results verify the model predictive DPC for the APF-integrated single-phase qZSI.« less

  5. Rainfall and human activity impacts on soil losses and rill erosion in vineyards (Ruwer Valley, Germany)

    NASA Astrophysics Data System (ADS)

    Rodrigo Comino, J.; Brings, C.; Lassu, T.; Iserloh, T.; Senciales, J. M.; Martínez Murillo, J. F.; Ruiz Sinoga, J. D.; Seeger, M.; Ries, J. B.

    2015-07-01

    Vineyards are one of the eco-geomorphological systems most conditioned by human activity in Germany. The vineyards of the Ruwer Valley (Germany) are characterized by high soil erosion rates and rill problems on steep slopes (between 23 and 26°) caused by the increasingly frequent heavy rainfall events as well as deterioration due to incorrect land use managements. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in one vineyard in Germany during different seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Climatic (rainfall depth distributions and return periods), pedological (soil analysis and classification), geomorphological (sediment movements and rills evolution) and biological (botanic marks on the vines) variables were used on the two experimental plots in the village of Waldrach (Trier, region of Rhineland-Palatinate). The results showed high infiltration rates (near 100 %) and subsurface flow which were detected by rainfall simulations performed at different times of the year (between September and December). The highest variations of the monitored rills (lateral and frontal movements) were noted before and during vintage, when footsteps occurred concentrated during a short period of time (between September and October). Finally, two maps of soil loss were generated, indicated by botanic marks on the graft union of the vines. 62.5 t ha-1 yr-1 soil loss was registered in the experimental plots of the new vineyards (2 years), while 3.4 t ha-1 yr-1 was recorded in the old one (35 years).

  6. Rainfall and human activity impacts on soil losses and rill erosion in vineyards (Ruwer Valley, Germany)

    NASA Astrophysics Data System (ADS)

    Rodrigo Comino, J.; Brings, C.; Lassu, T.; Iserloh, T.; Senciales, J. M.; Martínez Murillo, J. F.; Ruiz Sinoga, J. D.; Seeger, M.; Ries, J. B.

    2015-01-01

    Vineyards are one of the most German conditioned eco-geomorphological systems by human activity. Precisely, the vineyards of the Ruwer Valley (Germany) is characterized by high soil erosion rates and rill problems on steep slopes (between 23-26°) caused by the increasingly frequent heavy rainfall events, what is sometimes enhanced by incorrect land use managements. Soil tillage before and after vintage, application of vine training systems and anthropic rills generated by wheel tracks and footsteps are observed along these cultivated area. The objective of this paper is to determine and to quantify the hydrological and erosive phenomena in two chosen vineyards, during diverse seasons and under different management conditions (before, during and after vintage). For this purpose, a combined methodology was applied. Investigating climatic, pedological, geomorphological and botanic-marks variables was suggested on the two experimental plot in the village of Waldrach (Trier, region of Rhineland-Palatinate). First, high infiltration rates (near 100%) and subsurface flow was detected by rainfall simulations performed at different times of the year. The second method to investigate the geomorphological response of slope inclination, two 10 m and one 30 m long rills were measured using geometrical channel cross-section index, depth and width. The highest variations (lateral and frontal movements) were noted before and during vintage, when footsteps occurred in a concentrated short time. Finally, two maps were generated of soil loss, indicated by the botanic marks on the graft union of the vines. As results 62.5 t-1 ha-1 yr-1 soil loss rate was registered (one year) on the experimental plots of the new vineyards, while 4.3 t-1 ha-1 yr-1 on the old one.

  7. [Active electronic hearing implants for middle and inner ear hearing loss--a new era in ear surgery. III: prospects for inner ear hearing loss].

    PubMed

    Zenner, H P; Leysieffer, H

    1997-10-01

    The perspectives for active hearing implants lie in the treatment of patients with sensorineural hearing loss (SNHL). The majority of patients with SNHL suffer from a cochlea amplifier (CA) failure which is discernible by a positive recruitment and loss of otoacoustic emissions (OAE). Therefore, the electronic implant is expected to partially replace functions of the CA. Thus, the implant is thought to function as a CAI (cochlea amplifier implant). An approved implant for routine use is not yet available. Clinical studies have thus far only used the high energy consuming (HEC), narrow-band, electromagnetic floating-mass transducer, as well as the Maniglia-HEC implant. The high energie consuming, yet broadband Canadian Fredrickson implant is soon to be used in humans. Of the piezoelectrical implants, a German CAI (Tübingen implant) at present consisting of a piezoelectrical transducer and a microphone has thus far been acutely implanted in first patient. It is a low energy consuming (LEC), broad-band implantable system for patients with sensorineural hearing loss. Routine surgical treatment of patients with sensorineural hearing loss with a CAI will only be achieved if complete implants (with transducer, microphones, batteries, and control unit) are made available. They combine distinct acoustic superiority with invisibility (end of stigmatization), an open ear canal, and hopefully, the end of feedback whistling. Among the implants mentioned, the German CAI is the only LEC implant. Its energy requirements are so low that with today's technologie implantable batteries (e.g., in pacemakers), the additional implantation of an energy carrier seems feasible. Since the implantable microphone is already available in the German system, the only essential part missing for a totally implantable CAI is the implantable control unit.

  8. Rapid loss of factor XII and XI activity in ellagic acid-activated normal plasma: role of plasma inhibitors and implications for automated activated partial thromboplastin time recording.

    PubMed

    Joist, J H; Cowan, J F; Khan, M

    1977-12-01

    Rapid prolongation of the aPTT of normal plasma upon incubation with ellagic acid containing aPTT reagents was observed. The aPTT prolongation was not due to time-dependent changes in pH in the incubation mixture or loss of activity of the labile coagulation factors VIII and V but occurred as a result of rapid progressive inactivation of ellagic acid-activated factors XII and XI. Prolongation of the aPTT and loss of contact factor activities was not observed in plasma incubated with particulate activator reagents. This finding seemed to indicate that adsorption of factors XII and XI to larger particles during the activation process might protect these factors from inactivation by naturally occurring plasma inhibitors. Evidence is presented which supports previous findings that C1-INH, alpha1-AT, and antithrombin (in the presence of heparin) contribute to factor XIIa and XI a inactivation in ellagic acid-activated plasma and that plasma albumin may compete with factor XII for ellagic acid binding. The data indicate that ellagic acid-containing aPTT reagents have unfavorable properties which seriously limit their usefulness in the clinical laboratory, particularly in respect to recording of the aPTT with certain fully automated clot timers.

  9. Polycythemia is associated with bone loss and reduced osteoblast activity in mice

    PubMed Central

    Casu, C.; Yang, Z.; Crielaard, B.; Shim, J. H.; Rivella, S.; Vogiatzi, M. G.

    2017-01-01

    Summary Increased fragility has been described in humans with polycythemia vera (PV). Herein, we describe an osteoporotic phenotype associated with decreased osteoblast activity in a mouse model of PV and another mouse of polycythemia and elevated circulating erythropoietin (EPO). Our results are important for patients with PV or those treated with recombinant EPO (rEPO). Introduction PV and other myeloproliferative syndromes have been recently associated with an increased risk for fractures. However, the presence of osteoporosis in these patients has not been well documented. EPO, a hormone primarily known to stimulate erythropoiesis, has been shown recently to regulate bone homeostasis in mice. The aim of this study was to examine the bone phenotype of a mouse model of PV and compare it to that of animals with polycythemia caused by elevated circulating EPO. Methods Bone mass and remodeling were evaluated by micro-computed tomography and histomorphometry. The JAK2V617F knock-in mouse, a model of human PV, manifests polycythemia and low circulating EPO levels. Results from this mouse were compared to wild type (wt) controls and the tg6 transgenic mouse that shows polycythemia caused by increased constitutive expression of EPO. Results Compared to wt, both JAK2V617F and tg6 mice had a decrease in trabecular bone mass. Tg6 mice showed an additional modest decrease in cortical thickness and cortical bone volume per tissue volume (P<0.01) suggesting a more severe bone phenotype than JAK2V617F. Decreased osteoblast numbers and bone formation along with normal osteoclast numbers and activity were found in both mice. Conclusions This study indicates that PV is associated with low bone mass and decreased osteoblast activity in mice. Our results support future studies of osteoporosis in affected humans. Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated. PMID:26650379

  10. Estrogenic activity and nutrient losses in surface runoff after winter manure application to small watersheds.

    PubMed

    Shappell, N W; Billey, L O; Shipitalo, M J

    2016-02-01

    Confined Animal Feeding Operations generate large amounts of wastes that are land-applied to provide nutrients for crop production and return organic matter to the soil. Production practices and storage limitations often necessitate that wastes be applied to frozen and snow-covered soil. Use of application setbacks have reduced concerns related to nutrient losses in surface runoff from manure, but the estrogenic activity of runoff under these conditions has not been evaluated. Therefore, we measured and sampled surface runoff when manure was applied in the winter at a rate to meet crop N needs and measured estradiol equivalents (E2Eqs) using E-Screen. In year one, six small watersheds used to produce corn were evaluated, treatments: 2 no-manure controls, 2 liquid swine manure with 30-m setbacks, and 2 turkey litter with 30-m setbacks. In addition, beef manure was applied to six frozen plots of forage. For years 2 and 3, applications were repeated on the swine manure watersheds and one control watershed. E2Eqs and nutrient concentrations generally peaked in the first runoff event after application. The highest measured E2Eq (5.6 ng L(-1)) was in the first event after swine manure application and was less than the 8.9 ng L(-1) Lowest Observable Effect Concentration (LOEC) for aquatic species and well below the concentrations measured in other studies using ELISAs to measure hormone concentrations. No runoff occurred from plots planted with forage, indicating low risk for environmental impact, and therefore plots were discontinued from study. In years 2 and 3, estrogenic activity never exceeded the Predicted No Effect Concentrations for E2 of 2 ng L(-1). When post-application runoff contained high estrogenic activity, strong correlations (R(2) 0.86 to 0.96) of E2Eq to Ca(2+), Mg(2+), and K(+) concentrations were observed, indicating under some condition these cations might be useful surrogates for E2Eq measurements.

  11. High-power, photofission-inducing bremsstrahlung source for intense pulsed active detection of fissile material

    NASA Astrophysics Data System (ADS)

    Zier, J. C.; Mosher, D.; Allen, R. J.; Commisso, R. J.; Cooperstein, G.; Hinshelwood, D. D.; Jackson, S. L.; Murphy, D. P.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Swanekamp, S. B.; Weber, B. V.

    2014-06-01

    Intense pulsed active detection (IPAD) is a promising technique for detecting fissile material to prevent the proliferation of special nuclear materials. With IPAD, fissions are induced in a brief, intense radiation burst and the resulting gamma ray or neutron signals are acquired during a short period of elevated signal-to-noise ratio. The 8 MV, 200 kA Mercury pulsed-power generator at the Naval Research Laboratory coupled to a high-power vacuum diode produces an intense 30 ns bremsstrahlung beam to study this approach. The work presented here reports on Mercury experiments designed to maximize the photofission yield in a depleted-uranium (DU) object in the bremsstrahlung far field by varying the anode-cathode (AK) diode gap spacing and by adding an inner-diameter-reducing insert in the outer conductor wall. An extensive suite of diagnostics was fielded to measure the bremsstrahlung beam and DU fission yield as functions of diode geometry. Delayed fission neutrons from the DU proved to be a valuable diagnostic for measuring bremsstrahlung photons above 5 MeV. The measurements are in broad agreement with particle-in-cell and Monte Carlo simulations of electron dynamics and radiation transport. These show that with increasing AK gap, electron losses to the insert and outer conductor wall increase and that the electron angles impacting the bremsstrahlung converter approach normal incidence. The diode conditions for maximum fission yield occur when the gap is large enough to produce electron angles close to normal, yet small enough to limit electron losses.

  12. 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.

  13. Physical activity as intervention for age-related loss of muscle mass and function: protocol for a randomised controlled trial (the LISA study)

    PubMed Central

    Eriksen, Christian Skou; Garde, Ellen; Reislev, Nina Linde; Wimmelmann, Cathrine Lawaetz; Bieler, Theresa; Ziegler, Andreas Kraag; Gylling, Anne Theil; Dideriksen, Kasper Juel; Siebner, Hartwig Roman; Mortensen, Erik Lykke; Kjaer, Michael

    2016-01-01

    Introduction Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative. The primary aim of this randomised controlled trial is to compare the efficacy of two different 1 year strength training regimens on immediate and long-lasting improvements in muscle power in retirement-age individuals. Secondary aims are to evaluate the effect on muscle strength, muscle mass, physical and cognitive function, mental well-being, health-related quality of life and brain morphology. Methods and analysis The study includes 450 home-dwelling men and women (62–70 years). Participants are randomly allocated to (1) 1 year of supervised, centre-based heavy resistance training, (2) home-based moderate intensity resistance training or (3) habitual physical activity (control). Changes in primary (leg extensor power) and secondary outcomes are analysed according to the intention to treat principle and per protocol at 1, 2, 4, 7 and 10 years. Ethics and dissemination The study is expected to generate new insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer-reviewed journals, in PhD theses and at public meetings. The study is approved by the Regional Ethical Committee (Capital Region, Copenhagen, Denmark, number H-3

  14. 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.

  15. Possible phase coherence of annulus resonant modes in a cylindrical cold plasma: A perspective on SOL losses of fast-wave power on NSTX

    NASA Astrophysics Data System (ADS)

    Perkins, Rory; Hosea, Joel; Bertelli, Nicola; Taylor, Gary; Wilson, James

    2016-10-01

    Efficient high-harmonic fast-wave (HHFW) heating on the National Spherical Torus eXperiment (NSTX) would enable new experiments in turbulence, energetic particles, and impurity transport. However, scrape-off layer (SOL) losses of HHFW power can severely limit the heating efficiency down to 40%. The power is lost along scrape-off layer field lines, creating bright spirals of heat deposition on the divertor. A cylindrical cold-plasma model finds modes, named ``annulus resonances,'' that conduct a large fraction of the wave power in the outer low-density region, making such modes a potential candidate to explain the SOL losses on NSTX. Here, we present result for full three-dimensional reconstructions of the wave fields. There is typically one such mode for each azimuthal mode number and a near linear relationship between azimuthal and axial wavenumbers, suggesting the existence of helices of constant phase. The potential role of these helices in relation to the field-aligned SOL losses will be discussed. This work was supported in part by DOE Contract No. DE-AC02-09CH11466.

  16. Ganser-like Syndrome After Loss of Psychic Self-activation Syndrome: Psychogenic or Organic?

    PubMed Central

    Kaphan, Elsa; Barbeau, Emmanuel; Royère, Marie L.; Guedj, Eric; Pelletier, Jean; Ali Chérif, André

    2014-01-01

    Very few data are available on the long-term changes in the cognitive abilities of patients with loss of psychic self-activation syndrome (LPSAS). Here, we present a 25-year follow-up study on a case of LPSAS resulting from bilateral pallidal lesions caused by carbon monoxide intoxication. Typical signs of LPSAS were observed, showing no changes in severity, but Ganser syndrome (GS) gradually developed and worsened during the follow-up period. GS is generally assumed to be a psychogenic syndrome, but an organic etiology has been suspected by the authors of several case reports. Here, atypical features of GS plead against the independence of GS and LPSAS. DaTSCAN and brain 18FDG-PET were performed. Since left hippocampal hypometabolism has been previously described in patients with functional amnesia, it is possible that long periods of mental inactivity may have psychological consequences, but the atypical features of GS also suggest that an organic mechanism may be involved. PMID:25280796

  17. Intermittent dust mass loss from activated asteroid P/2013 P5 (PANSTARRS)

    SciTech Connect

    Moreno, F.; Pozuelos, F.

    2014-02-01

    We present observations and models of the dust environment of activated asteroid P/2013 P5 (PANSTARRS). The object displayed a complex morphology during the observations, with the presence of multiple tails. We combined our own observations, all made with instrumentation attached to the 10.4 m Gran Telescopio Canarias on La Palma, with previously published Hubble Space Telescope images to build a model aimed at fitting all the observations. Altogether, the data cover a full three month period of observations which can be explained by intermittent dust loss. The most plausible scenario is that of an asteroid rotating with the spinning axis oriented perpendicular to the orbit plane and losing mass from the equatorial region, consistent with rotational break-up. Assuming that the ejection velocity of the particles (v ∼ 0.02-0.05 m s{sup –1}) corresponds to the escape velocity, the object diameter is constrained to ∼30-130 m for bulk densities 3000-1000 kg m{sup –3}.

  18. Active loss of DNA methylation in two-cell stage goat embryos.

    PubMed

    Park, Jung S; Lee, Doosoo; Cho, Sunwha; Shin, Sang-Tae; Kang, Yong-Kook

    2010-01-01

    Early mammalian embryos are thought to gain nuclear totipotency through DNA methylation reprogramming (DMR). By this process, DNA methylation patterns acquired during gametogenesis that are unnecessary for zygotic development are erased. The DMR patterns of various mammalian species have been studied; however, they do not seem to have a conserved pattern. We examined early goat embryos to find conforming rules underlying mammalian DMR patterns. Immunocytochemical results showed that the overall level of DNA methylation was not greatly changed during the pronucleus stage. At the two-cell stage, active demethylation occurred and simultaneously affected both parental DNAs, resulting in a global loss of 5-methylcytosine. The level of DNA methylation was lowest in the four-cell stage, with increased de novo methylation during the eight-cell stage. Histone H3-lysine 9 was gradually trimethylated in the sperm-derived chromatin, continuing from the pronucleus stage through the two-cell stage. This goat DMR pattern is novel and distinct from the DMRs of other mammalian species. The more mammalian species we included for DMR analysis, the more multifarious patterns we obtained, adding an extra diversity each time to the known mammalian DMR patterns. Nevertheless, the evolutionary significance and developmental consequence of such diverse DMR patterns are currently unknown.

  19. Activated protein C rescues the cochlea from noise-induced hearing loss.

    PubMed

    Kurioka, Takaomi; Matsunobu, Takeshi; Niwa, Katsuki; Tamura, Atsushi; Satoh, Yasushi; Shiotani, Akihiro

    2014-10-02

    Activated protein C (APC) is a serine/threonine protease and a physiological anticoagulant that exerts anti-inflammatory and anti-apoptotic effects. Although recent studies have revealed that APC has the potential to protect endothelial cells from apoptosis, the mechanisms of its cytoprotective effect are not fully understood. We examined the potential of APC to protect against noise-induced hearing loss (NIHL) and investigated phosphorylation of serine-threonine kinase (Akt) and inhibition of apoptosis as possible cytoprotective mechanisms. We administered intraperitoneal injections of APC (150, 300 U/kg) or normal saline to rats 30 min before exposure to a sound pressure level (SPL) of 126 dB and 4-kHz octave band noise for 5h. The auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) were measured before and after exposure. ABR and DPOAE measurements revealed greater improvement in the APC group than in the control group 28 days after exposure. Our examination of outer hair cells (OHCs) at 28 days after noise exposure revealed a significantly higher OHC survival rate in the APC group than in the control group. Immunohistochemical analyses for cleaved-caspase 3, phospho-p38 (p-p38), TUNEL, and phospho-Akt (p-Akt) revealed strong immunoreactivities against cleaved-caspase 3, p-p38, and TUNEL in the inner ear tissues of the control group; however, these signals were decreased in the APC group. Moreover, APC significantly induced activation of p-Akt in the cochlea. These findings suggest that APC has a novel protective effect on the cochlea against NIHL that is mediated by p-Akt and the anti-apoptotic signaling pathway.

  20. The loss of activating transcription factor 4 (ATF4) reduces bone toughness and fracture toughness.

    PubMed

    Makowski, Alexander J; Uppuganti, Sasidhar; Wadeer, Sandra A; Whitehead, Jack M; Rowland, Barbara J; Granke, Mathilde; Mahadevan-Jansen, Anita; Yang, Xiangli; Nyman, Jeffry S

    2014-05-01

    Even though age-related changes to bone tissue affecting fracture risk are well characterized, only a few matrix-related factors have been identified as important to maintaining fracture resistance. As a gene critical to osteoblast differentiation, activating transcription factor 4 (ATF4) is possibly one of these important factors. To test the hypothesis that the loss of ATF4 affects the fracture resistance of bone beyond bone mass and structure, we harvested bones from Atf4+/+ and Atf4-/- littermates at 8 and 20 weeks of age (n≥9 per group) for bone assessment across several length scales. From whole bone mechanical tests in bending, femurs from Atf4-/- mice were found to be brittle with reduced toughness and fracture toughness compared to femurs from Atf4+/+ mice. However, there were no differences in material strength and in tissue hardness, as determined by nanoindentation, between the genotypes, irrespective of age. Tissue mineral density of the cortex at the point of loading as determined by micro-computed tomography was also not significantly different. However, by analyzing local composition by Raman Spectroscopy (RS), bone tissue of Atf4-/- mice was found to have higher mineral to collagen ratio compared to wild-type tissue, primarily at 20 weeks of age. From RS analysis of intact femurs at 2 orthogonal orientations relative to the polarization axis of the laser, we also found that the organizational-sensitive peak ratio, ν1Phosphate per Amide I, changed to a greater extent upon bone rotation for Atf4-deficient tissue, implying bone matrix organization may contribute to the brittleness phenotype. Target genes of ATF4 activity are not only important to osteoblast differentiation but also in maintaining bone toughness and fracture toughness.

  1. The Loss of Activating Transcription Factor 4 (ATF4) Reduces Bone Toughness and Fracture Toughness

    PubMed Central

    Makowski, Alexander J.; Uppuganti, Sasidhar; Waader, Sandra A.; Whitehead, Jack M.; Rowland, Barbara J.; Granke, Mathilde; Mahadevan-Jansen, Anita; Yang, Xiangli; Nyman, Jeffry S.

    2014-01-01

    Even though age-related changes to bone tissue affecting fracture risk are well characterized, only a few matrix-related factors have been identified as important to maintaining fracture resistance. As a gene critical to osteoblast differentiation, activating transcription factor 4 (ATF4) is possibly one of the seimportant factors. To test the hypothesis that the loss of ATF4 affects the fracture resistance of bone beyond bone mass and structure, we harvested bones from Atf4+/+ and Atf4−/− littermates at 8 and 20 weeks of age (n≥9 per group) for bone assessment across several length scales. From whole bone mechanical tests in bending, femurs from Atf4−/− mice were found to be brittle with reduced toughness and fracture toughness compared to femurs from Atf4+/+ mice. However, there were no differences in material strength and in tissue hardness, as determined by nanoindentation, between the genotypes, irrespective age. Tissue mineral density of the cortex at the point of loading as determined by micro-computed tomography was also not significantly different. However, by analyzing local composition by Raman Spectroscopy (RS), bone tissue of Atf4−/− mice was found to have higher mineral to collagen ratio compared to wild-type tissue, primarily at 20 weeks of age. From RS analysis of intact femurs at 2 orthogonal orientations relative to the polarization axis of the laser, we also found that the organizational-sensitive peak ratio, ν1 Phosphate per Amide I, changed to a greater extent upon bone rotation for Atf4-deficient tissue, implying bone matrix organization may contribute to the brittleness phenotype. Target genes of ATF4 activity are not only important to osteoblast differentiation but also maintaining bone toughness and fracture toughness. PMID:24509412

  2. Erbin loss promotes cancer cell proliferation through feedback activation of Akt-Skp2-p27 signaling

    SciTech Connect

    Huang, Hao; Song, Yuhua; Wu, Yan; Guo, Ning; Ma, Yuanfang; Qian, Lu

    2015-07-31

    Erbin localizes at the basolateral membrane to regulate cell junctions and polarity in epithelial cells. Dysregulation of Erbin has been implicated in tumorigenesis, and yet it is still unclear if and how disrupted Erbin regulates the biological behavior of cancer cells. We report here that depletion of Erbin leads to cancer cell excessive proliferation in vitro and in vivo. Erbin deficiency accelerates S-phase entry by down-regulating CDK inhibitors p21 and p27 via two independent mechanisms. Mechanistically, Erbin loss promotes p27 degradation by enhancing E3 ligase Skp2 activity though augmenting Akt signaling. Interestingly, we also show that Erbin is an unstable protein when the Akt-Skp2 signaling is aberrantly activated, which can be specifically destructed by SCF-Skp2 ligase. Erbin loss facilitates cell proliferation and migration in Skp2-dependent manner. Thus, our finding illustrates a novel negative feedback loop between Erbin and Akt-Skp2 signaling. It suggests disrupted Erbin links polarity loss, hyperproliferation and tumorigenesis. - Highlights: • Erbin loss leads to cancer cell excessive proliferation in vitro and in vivo. • Erbin loss accelerates cell cycle though down-regulating p21 and p27 expression. • Erbin is a novel negative modulator of Akt1-Skp2-p27 signaling pathway. • Our study suggests that Erbin loss contributes to Skp2 oncogenic function.

  3. 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.

  4. Loss of plant biodiversity eliminates stimulatory effect of elevated CO2 on earthworm activity in grasslands.

    PubMed

    Arnone, John A; Zaller, Johann G; Hofer, Gabriela; Schmid, Bernhard; Körner, Christian

    2013-03-01

    Earthworms are among the world's most important ecosystem engineers because of their effects on soil fertility and plant productivity. Their dependence on plants for carbon, however, means that any changes in plant community structure or function caused by rising atmospheric CO2 or loss of plant species diversity could affect earthworm activity, which may feed back on plant communities. Production of surface casts measured during three consecutive years in field experimental plots (n = 24, 1.2 m(2)) planted with local calcareous grassland species that varied in plant species richness (diversity levels: high, 31 species; medium, 12; low, 5) and were exposed to ambient (356 μl CO2 l(-1)) or elevated (600 μl CO2 l(-1)) CO2 was only consistently stimulated in high diversity plots exposed to elevated CO2 (+120 %, 31 spp: 603 ± 52 under ambient CO2 vs. 1,325 ± 204 g cast dwt. m(-2) year(-1) under elevated CO2 in 1996; +77 %, 940 ± 44 vs. 1,663 ± 204 g cast dwt. m(-2) year(-1) in 1998). Reductions in plant diversity had little effect on cast production in ecosystems maintained at ambient CO2, but the stimulatory effect of elevated CO2 on cast production disappeared when plant species diversity was decreased to 12 and 5 species. High diversity plots were also the only communities that included plant species that an earlier field study showed to be among the most responsive to elevated CO2 and to be most preferred by earthworms to deposit casts near. Further, the +87 % CO2-induced increase in cast production measured over the 3 years corresponded to a parallel increase in cumulative total nitrogen of 5.7 g N m(-2) and would help explain the large stimulation of aboveground plant biomass production observed in high-diversity communities under elevated CO2. The results of this study demonstrate how the loss of plant species from communities can alter responses of major soil heterotrophs and consequently ecosystem biogeochemistry.

  5. The effect of nano-SiO 2 on the magnetic properties of the low power loss manganese-zinc ferrites

    NASA Astrophysics Data System (ADS)

    Nie, Jianhu; Li, Haihua; Feng, Zekun; He, Huahui

    2003-09-01

    The effect of the addition of nano-SiO 2 on the power losses in the manganese-zinc ferrites has been investigated by measuring the magnetic properties and observing the grain boundary structures. The powders of Mn 0.72Zn 0.21Fe 2.07O 4 composition were prepared by using a conventional ceramic powder processing technique. Toroidal cores were sintered at 1340°C for 4 h using a tube furnace with atmosphere controlled by using the equation for equilibrium oxygen partial pressure. The microstructure of grain boundary was observed by AES and SEM. It has been found that the grain boundaries resistivity and magnetic loss are greatly dependent upon the content of nano-SiO 2. There is an optimum content of nano-SiO 2 to produce uniform grain structure and low magnetic loss. The eddy current losses were reduced by the addition of nano-SiO 2. These losses are thought to originate from the additive effect of Si atoms, which are enriched in grain boundaries to form a high resistivity layer and prevent Ca and Nb atoms being incorporated with the spinel lattice.

  6. 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.

  7. Active cooling solutions for high power laser diodes stacks

    NASA Astrophysics Data System (ADS)

    Karni, Yoram; Klumel, Genady; Levy, Moshe; Berk, Yuri; Openhaim, Yaki; Gridish, Yaakov; Elgali, Asher; Avisar, Meir; Blonder, Moshe; Sagy, Hila; Gertsenshtein, Alex

    2008-02-01

    High power water cooled diode lasers find increasing demand in biomedical, cosmetic and industrial applications, where very high brightness and power are required. The high brightness is achieved either by increasing the power of each bar or by reducing the emitting area of the stacks. Two new products will be presented: Horizontal CW stacks with output power as high as 1kW using 80 W bars with emitting area width as low as 50 μm Vertical QCW stacks with output power as high as 1.2kW using 120 W bars. Heat removal from high power laser stacks often requires microchannel coolers operated with finely filtered deionized (DI) water. However, for certain industrial applications the reliability of this cooling method is widely considered insufficient due to leakage failures caused the highly corrosive DI water. Two solutions to the above problem will be discussed. A microchannel cooler-based package, which vastly reduces the corrosion problem, and a novel high-power laser diode stack that completely eliminates it. The latter solution is especially effective for pulsed applications in high duty cycle range.

  8. Loss of power output and laser fibre degradation during 120 watt lithium-triborate HPS laser vaporisation of the prostate

    NASA Astrophysics Data System (ADS)

    Hermanns, Thomas; Sulser, Tullio; Hefermehl, Lukas J.; Strebel, Daniel; Michel, Maurice-Stephan; Müntener, Michael; Meier, Alexander H.; Seifert, Hans-Helge

    2009-02-01

    It has recently been shown that laser fibre deterioration leads to a significant decrease of power output during 80 W potassium titanyl phosphate (KTP) laser vaporisation (LV) of the prostate. This decrease results in inefficient vaporisation especially towards the end of the procedure. For the new 120 W lithium-triborate (LBO) High Performance System (HPS) laser not only higher power but also changes in beam characteristics and improved fibre quality have been advertised. However, high laser power has been identified as a risk factor for laser fibre degradation. Between July and September 2008 25 laser fibres were investigated during routine 120 W LBO-LV in 20 consecutive patients. Laser beam power was measured at baseline and after the application of every 25 kJ during the LV procedure. Postoperatively, the surgeon subjectively rated the performance of the respective fibre on a scale from 1 to 4 (1 indicating perfect and 4 insufficient performance). Additionally, microscopic examination of the fibre tip was performed. Median energy applied was 212 kJ. Changes of power output were similar for all fibres. Typically, a steep decrease of power output within the first 50 kJ was followed by a continuous mild decrease until the end of the procedure. After the application of 50 kJ the median power output was 63% (58-73% interquartile range) of the baseline value. The median power output at the end of the 275 kJ-lifespan of the fibres was 42% (40-47%). The median surgeons' rating of the overall performance of the laser fibres was 2 and the median estimated final decrease of power output 60%. Some degree of degradation at the emission window was microscopically detectable in all cases after the procedure. However, even after the application of 275 kJ, these structural changes were only moderate. Minor degradation of the laser fibre was associated with a significant decrease of power output during 120 W LBO-LV. However, following an early, steep decrease, power output

  9. Windage Power Loss in Gas Foil Bearings and the Rotor-Stator Clearance of High Speed Generators Operating in High Pressure Environments

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2009-01-01

    Closed Brayton Cycle (CBC) and Closed Supercritical Cycle (CSC) engines are prime candidates to convert heat from a reactor into electric power for robotic space exploration and habitation. These engine concepts incorporate a permanent magnet starter/generator mounted on the engine shaft along with the requisite turbomachinery. Successful completion of the long-duration missions currently anticipated for these engines will require designs that adequately address all losses within the machine. The preliminary thermal management concept for these engine types is to use the cycle working fluid to provide the required cooling. In addition to providing cooling, the working fluid will also serve as the bearing lubricant. Additional requirements, due to the unique application of these microturbines, are zero contamination of the working fluid and entirely maintenance-free operation for many years. Losses in the gas foil bearings and within the rotor-stator gap of the generator become increasingly important as both rotational speed and mean operating pressure are increased. This paper presents the results of an experimental study, which obtained direct torque measurements on gas foil bearings and generator rotor-stator gaps. Test conditions for these measurements included rotational speeds up to 42,000 revolutions per minute, pressures up to 45 atmospheres, and test gases of nitrogen, helium, and carbon dioxide. These conditions provided a maximum test Taylor number of nearly one million. The results show an exponential rise in power loss as mean operating density is increased for both the gas foil bearing and generator windage. These typical "secondary" losses can become larger than the total system output power if conventional design paradigms are followed. A nondimensional analysis is presented to extend the experimental results into the CSC range for the generator windage.

  10. Skeletal Muscle Loss is Associated with TNF Mediated Insufficient Skeletal Myogenic Activation After Burn

    PubMed Central

    Song, Juquan; Saeman, Melody R; De Libero, Jana; Wolf, Steven E

    2015-01-01

    Muscle loss accompanies severe burn; in this hyper-catabolic state, muscle undergoes atrophy through protein degradation and disuse. Muscle volume is related to the relative rates of cellular degradation and myogenesis. We hypothesize that muscle atrophy after injury is in part due to insufficient myogenesis associated with the hyper-inflammatory response. The aim of the study is to investigate the role of skeletal myogenesis and muscle cell homeostasis in response to severe burn. Twenty-eight male C57BL6 mice received 25% TBSA scald. Gluteus muscle from these animals was analysed at day 1, 3, 7 and 14 after injury. Six additional animals without burn served as controls. We showed muscle wet weight and protein content decreased at day 3 and 7 after burn, with elevated TNF mRNA expression (p< 0.05). Increased cell death was observed through TUNEL staining, and cleaved caspase-3 levels reached a peak in muscle lysate at day 3 (p < 0.05). The cell proliferation marker PCNA significantly increased after burn, associated with increased gene and protein expression of myogenesis markers Pax7 and myogenin. However, desmin mRNA expression and the ratio of desmin to PCNA protein expression significantly decreased at day 7 (p < 0.05). In vitro, the ratio of desmin to PCNA protein expression significantly decreased in C2C12 murine myoblasts after TNF-α stimulation for 24 hours. We showed that severe burn induces both increased cell death and proliferation. However, myogenesis does not counterbalance increased cell death after burn. Data suggest insufficient myogenesis might be associated with pro-inflammatory mediator TNF activity. PMID:26196842

  11. A rapidly occurring compensatory decrease in physical activity counteracts diet-induced weight loss in female monkeys.

    PubMed

    Sullivan, Elinor L; Cameron, Judy L

    2010-04-01

    To study changes in energy balance occurring during the initial phases of dieting, 18 adult ovariectomized female monkeys were placed on a low-fat diet, and available calories were reduced by 30% compared with baseline consumption for 1 mo. Surprisingly, there was not significant weight loss; however, daily activity level (measured by accelerometry) decreased soon after diet initiation and reached statistical significance by the 4th wk of dieting (18 +/- 5.6% decrease, P = 0.02). During a 2nd mo of dieting, available calories were reduced by 60% compared with baseline consumption, leading to 6.4 +/- 1.7% weight loss and further suppression of activity. Metabolic rate decreased by 68 +/- 12 kcal/day, with decreased activity accounting for 41 +/- 9 kcal/day, and the metabolic activity of the weight lost accounting for 21 +/- 5 kcal/day. A second group of three monkeys was trained to run on a treadmill for 1 h/day, 5 days/wk, at 80% maximal capacity, leading to increased calorie expenditure of 69.6 +/- 10.7 kcal/day (equivalent to 49 kcal/day for 7 days). We conclude that a diet-induced decrease in physical activity is the primary mechanism the body uses to defend against diet-induced weight loss, and undertaking a level of exercise that is recommended to counteract weight gain and promote weight loss is able to prevent the compensatory decrease in physical activity-associated energy expenditure that slows diet-induced weight loss.

  12. Daily energy expenditure and physical activity measured in Parkinson's disease patients with and without weight loss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Patients with Parkinson's disease (PD) commonly exhibit weight loss, which investigators attribute to various factors, including elevated resting energy expenditure. We tested the hypothesis that daily energy expenditure (DEE) and its components, resting energy expenditure (REF) and physical activit...

  13. Loss compensation in metamaterials through embedding of active transistor based negative differential resistance circuits.

    PubMed

    Xu, Wangren; Padilla, Willie J; Sonkusale, Sameer

    2012-09-24

    Dielectric and ohmic losses in metamaterials are known to limit their practical use. In this paper, an all-electronic approach for loss compensation in metamaterials is presented. Each unit cell of the meta-material is embedded with a cross-coupled transistor pair based negative differential resistance circuit to cancel these losses. Design, simulation and experimental results for Split Ring Resonator (SRR) metamaterials with and without loss compensation are presented. Results indicate that the quality factor (Q) of the SRR improves by over 400% at 1.6 GHz, showing the effectiveness of the approach. The proposed technique is scalable over a broad frequency range and is limited only by the maximum operating frequency of transistors, which is reaching terahertz in today's semiconductor technologies.

  14. IMPACT OF GENETIC STRAIN ON BODY FAT LOSS, FOOD CONSUMPTION, METABOLISM, VENTILATION, AND MOTOR ACTIVITY IN FREE RUNNING FEMALE RATS

    EPA Pesticide Factsheets

    Physiologic data associated with different strains of common laboratory rat strains.This dataset is associated with the following publication:Gordon , C., P. Phillips , and A. Johnstone. Impact of Genetic Strain on Body Fat Loss, Food Consumption, Metabolism, Ventilation, and Motor Activity in Free Running Female Rats. PHYSIOLOGY AND BEHAVIOR. Elsevier Science Ltd, New York, NY, USA, 153: 56-63, (2016).

  15. Psychological Factors Associated with Weight Loss in Obese and Severely Obese Women in a Behavioral Physical Activity Intervention

    ERIC Educational Resources Information Center

    Annesi, James J.; Whitaker, Ann C.

    2010-01-01

    The behavioral processes of weight reduction are poorly understood, and responses to treatments based primarily on caloric restriction have been unfavorable. A theory-based path derived from proposed relations of physical activity, changes in psychological factors, and weight loss was separately tested with women with Class I and Class II obesity…

  16. TrkB Activators for the Treatment of Traumatic Vision Loss

    DTIC Science & Technology

    2015-10-01

    14. ABSTRACT Pressure waves due to explosions can damage the neurons of the eye and visual centers in the brain, leading to functional loss of...blast overpressure model of ocular trauma. HIOC produced a significant preservation of visual function, which in some experiments was nearly complete...prevented the loss of visual function caused by blast directed at the head. 15. SUBJECT TERMS trauma, neuroprotection, retina, optic nerve, TrkB, BDNF

  17. Cancer and Chemotherapy Contribute to Muscle Loss by Activating Common Signaling Pathways

    PubMed Central

    Barreto, Rafael; Mandili, Giorgia; Witzmann, Frank A.; Novelli, Francesco; Zimmers, Teresa A.; Bonetto, Andrea

    2016-01-01

    and chemotherapy contribute to muscle loss by activating common signaling pathways. These data support the undertaking of combination strategies that aim to both counteract tumor growth and reduce chemotherapy side effects. PMID:27807421

  18. Difficulty swallowing and lack of receipt of highly active antiretroviral therapy predict acute weight loss in human immunodeficiency virus disease.

    PubMed

    Jacobson, Denise L; Bica, Ioana; Knox, Tamsin A; Wanke, Christine; Tchetgen, Eric; Spiegelman, Donna; Silva, Marisela; Gorbach, Sherwood; Wilson, Ira B

    2003-11-15

    In human immunodeficiency virus (HIV) disease, symptoms of underlying illness may promote weight loss through decreased caloric intake, increased metabolic needs, or nutrient malabsorption. We evaluated disease symptoms as predictors of acute weight loss (i.e., loss of > or =5% of weight). HIV-infected men and women (n=415) were telephoned every 5 weeks to obtain information about weight and recent symptoms. Weight change between each pair of consecutive calls (telephone intervals, 2814) was calculated. Acute weight loss occurred across 4.5% of intervals and among 24% of individuals. Patients reported > or =1 symptom before 58% of telephone intervals. The most common symptoms or symptom complexes before intervals were diarrhea (21% of patients), anorexia (17%), upper respiratory symptoms (16%), skin symptoms (12%), and abdominal pain (12%). Trouble swallowing (6%) and oral symptoms (7%) were less common. Risk of acute weight loss was significantly increased when oral symptoms or trouble swallowing were present, and it was decreased when highly active antiretroviral therapy (HAART) was used or when diarrhea was not present. Even when HAART is being administered, clinicians should remain vigilant regarding weight loss, oral symptoms, and trouble swallowing.

  19. 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...

  20. 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.

  1. 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.

  2. Out of control!? How loss of self-control influences prosocial behavior: the role of power and moral values.

    PubMed

    Joosten, Anne; van Dijke, Marius; Van Hiel, Alain; De Cremer, David

    2015-01-01

    Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon people's level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees.

  3. Out of Control!? How Loss of Self-Control Influences Prosocial Behavior: The Role of Power and Moral Values

    PubMed Central

    Joosten, Anne; van Dijke, Marius; Van Hiel, Alain; De Cremer, David

    2015-01-01

    Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon people’s level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees. PMID:26024380

  4. Economic evaluation of losses to electric power utilities caused by ash fouling. Final technical report, November 1, 1979-April 30, 1980

    SciTech Connect

    Burkhardt, F.R.; Persnger, M.M.

    1980-01-01

    Problems with convection ash fouling and wall slagging were considerable during our study. The Dakota lignites posed the greatest problems, particularly with fouling. The subbituminous coals had considerable problems, related mostly with wall slagging. The Texas lignites had few problems, and those were only associated with wall slagging. The generation losses were as follows: The Dakota lignite burning stations averaged an overall availability of 87.13%. Convection fouling outages were responsible for 57.75% of this outage time for a decrease in availability of 7.43%. Fouling was responsible for curtailment losses of 317,649 Mwh or 8.25% of the remaining available generation. Slagging was responsible for losses of 2732 megawatt hours or .07% of the remaining available generation. Total ash related losses amounted to 16.08% of the total available generation. The subbituminous burning stations averaged an overall availability of 78.36%. Total ash related losses amounted to 1.54% of the total available generation. The Texas lignite burning stations averaged an overall availability of 80.63%. No ash related outage losses occurred. Slagging curtailments accounted 0.08% of the total available generation. Costs due to ash fouling and slagging related curtailments are a tremendous sum. Seven power stations were studied for a six month period to assess costs. The total cost directly attributable to ash slagging and fouling condition was $20,638,113. Recommendations for reducing the problems involve soot blowers, control of furnace gas exit temperature, water blowers and more conservative boiler design.

  5. Differential activation of the striatum for decision making and outcomes in a monetary task with gain and loss.

    PubMed

    Ino, Tadashi; Nakai, Ryusuke; Azuma, Takashi; Kimura, Toru; Fukuyama, Hidenao

    2010-01-01

    We examined brain activation for decision making and for different monetary outcomes in a two-alternative choice task with monetary rewards and punishments. Brain hemodynamic changes were monitored by functional MRI (fMRI) when seventeen healthy volunteers performed a task in which they were required to press one of two buttons (button 1 or 2) which increased or decreased their previously endowed money depending upon accord or disaccord with the number (1 or 2) which was displayed later. The amount of money subjects gained or lost was large when they selected 2 and small when they selected 1. They were informed in advance that the order of the appearance of 1 or 2 at outcome phase was predetermined and random, irrespective of their selection, and that the expected value was mathematically zero for both selecting 1 and 2. Results of fMRI showed that bilateral putamen and nucleus accumbens were more activated when selecting large gain or loss option than selecting small gain or loss option, and the right putamen and nucleus accumbens were more activated for gain outcome than for loss outcome. No significantly different activation of the striatum was found between large gain outcome and small gain outcome, suggesting that activity of the striatum at outcome phase was insensitive for reward magnitude when expectation by subject was already performed. We also found that activations of the bilateral putamen were correlated parametrically with stock amount of money.

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

    DOE PAGES

    Tlustý, Josef; Škramlík, Jiří; Švec, Jan; ...

    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. Ferroelectric Polymers with Ultrahigh Energy Density, Low Loss, and Broad Operation Temperature for Navy Pulse Power Capacitors

    DTIC Science & Technology

    2014-02-01

    depending on the crystallinity.[29]This extremely low low-field cunent explains why there is virtually no conduction loss in polypropylene at low voltages...electrical conduction in polypropylene ," Jpn. J. Appl. Phys, vol. 20, no. 3, p. 609, 1981. [30] J. M. Levy-Leblond and J. P. Provost, "Critical...K. Tripathi, and R. G. Mendiratta, " Thermally stimulated discharge current studies in polarized polypropylene ," p^/co status solidi (a), vol. 67

  8. Active Q switching in a GaAs/AlGaAs multiquantum well laser with an intracavity monolithic loss modulator

    NASA Technical Reports Server (NTRS)

    Arakawa, Y.; Larsson, A.; Paslaski, J.; Yariv, A.

    1986-01-01

    Active Q switching in a GaAs/AlGaAs multiquantum well laser with an intracavity electroabsorption monolithic loss modulator is demonstrated. In this device, an efficient loss modulation is achieved through the quantum confined Stark effect in a modulator section and the enhanced carrier induced band shrinkage effect in an optical amplifier section. It is found that a picosecond pulse as narrow as 18.6 ps full width at half-maximum is generated and a high repetition rate of more than 3 GHz is obtained.

  9. Loss-of-function of β-catenin bar-1 slows development and activates the Wnt pathway in Caenorhabditis elegans.

    PubMed

    van der Bent, M Leontien; Sterken, Mark G; Volkers, Rita J M; Riksen, Joost A G; Schmid, Tobias; Hajnal, Alex; Kammenga, Jan E; Snoek, L Basten

    2014-05-13

    C. elegans is extensively used to study the Wnt-pathway and most of the core-signalling components are known. Four β-catenins are important gene expression regulators in Wnt-signalling. One of these, bar-1, is part of the canonical Wnt-pathway. Together with Wnt effector pop-1, bar-1 forms a transcription activation complex which regulates the transcription of downstream genes. The effects of bar-1 loss-of-function mutations on many phenotypes have been studied well. However, the effects on global gene expression are unknown. Here we report the effects of a loss-of-function mutation bar-1(ga80). By analysing the transcriptome and developmental phenotyping we show that bar-1(ga80) impairs developmental timing. This developmental difference confounds the comparison of the gene expression profile between the mutant and the reference strain. When corrected for this difference it was possible to identify genes that were directly affected by the bar-1 mutation. We show that the Wnt-pathway itself is activated, as well as transcription factors elt-3, pqm-1, mdl-1 and pha-4 and their associated genes. The outcomes imply that this response compensates for the loss of functional bar-1. Altogether we show that bar-1 loss-of function leads to delayed development possibly caused by an induction of a stress response, reflected by daf-16 activated genes.

  10. 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.

  11. Favorite Lesson Plans: Powerful Standards-Based Activities.

    ERIC Educational Resources Information Center

    Wilen, William W., Ed.

    This collection of lesson plans helps social studies teachers and teacher educators implement the various national and state standards in their classrooms. The collection illustrates how classroom implementation can be achieved through the application of the powerful teaching and learning principles devised by National Council for the Social…

  12. Unified active and reactive power modulation of HVDC transmission systems

    NASA Astrophysics Data System (ADS)

    Grund, C. E.; Pohl, R. V.

    1981-11-01

    The power modulation of a high voltage direct current (HVDC) system for stabilization of an ac/dc network was investigated. It was found that simultaneous modulation of both dc current and voltage was more effective than just current modulation by itself, since the dc voltage modulation could be used to minimize the reactive power changes resulting from a change of the dc current. This helps stabilize the ac busbar voltages at the converters, which reduces undesirable load flow changes to voltage dependent ac loads, thus improving the effectiveness of the dc power modulation. This unified modulation control concept was evaluated by means of digital computer studies as well as a special purpose HVDC simulator. Several combined ac/dc power transmission systems were synthesized for testing of different modulation controller concepts. An optimum controller design incorporating a linear quadratic control algorithm with full state feedback was first studied. This provided a basis for comparison of suboptimal controller designs utilizing reduced state feedback and a Kalman filter state reconstruction technique.

  13. Loss of Power in Logistic, Ordinal Logistic, and Probit Regression When an Outcome Variable Is Coarsely Categorized

    ERIC Educational Resources Information Center

    Taylor, Aaron B.; West, Stephen G.; Aiken, Leona S.

    2006-01-01

    Variables that have been coarsely categorized into a small number of ordered categories are often modeled as outcome variables in psychological research. The authors employ a Monte Carlo study to investigate the effects of this coarse categorization of dependent variables on power to detect true effects using three classes of regression models:…

  14. Applicability of Loss of Offsite Power (LOSP) Events in NUREG/CR-6890 for Entergy Nuclear South (ENS) Plants LOSP Calculations

    SciTech Connect

    Li, Yunlong; Yilmaz, Fatma; Bedell, Loys

    2006-07-01

    Significant differences have been identified in loss of offsite power (LOSP or LOOP) event description, category, duration, and applicability between the LOSP events used in NUREG/CR-6890 and ENS'LOSP packages, which were based on EPRI LOSP reports with plant-specific applicability analysis. Thus it is appropriate to reconcile the LOSP data listed in the subject NUREG and EPRI reports. A cross comparison showed that 62 LOSP events in NUREG/CR-6890 were not included in the EPRI reports while 4 events in EPRI reports were missing in the NUREG. Among the 62 events missing in EPRI reports, the majority were applicable to shutdown conditions, which could be classified as category IV events in EPRI reports if included. Detailed reviews of LERs concluded that some events did not result in total loss of offsite power. Some LOSP events were caused by subsequent component failures after a turbine/plant trip, which have been modeled specifically in most ENS plant PRA models. Moreover, ENS has modeled (or is going to model) the partial loss of offsite power events with partial LOSP initiating events. While the direct use of NUREG/CR-6890 results in SPAR models may be appropriate, its direct use in ENS' plant PRA models may not be appropriate because of modeling details in ENS' plant-specific PRA models. Therefore, this paper lists all the differences between the data in NUREG/CR-6890 and EPRI reports and evaluates the applicability of the LOSP events to ENS plant-specific PRA models. The refined LOSP data will characterize the LOSP risk in a more realistic fashion. (authors)

  15. Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

    NASA Astrophysics Data System (ADS)

    Yan, Shuai; Sun, Weichao

    2017-09-01

    Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

  16. Loss of HtrA2/Omi activity in non-neuronal tissues of adult mice causes premature aging.

    PubMed

    Kang, S; Louboutin, J-P; Datta, P; Landel, C P; Martinez, D; Zervos, A S; Strayer, D S; Fernandes-Alnemri, T; Alnemri, E S

    2013-02-01

    mnd2 mice die prematurely as a result of neurodegeneration 30-40 days after birth due to loss of the enzymatic activity of the mitochondrial quality control protease HtrA2/Omi. Here, we show that transgenic expression of human HtrA2/Omi in the central nervous system of mnd2 mice rescues them from neurodegeneration and prevents their premature death. Interestingly, adult transgenic mnd2 mice develop accelerated aging phenotypes, such as premature weight loss, hair loss, reduced fertility, curvature of the spine, heart enlargement, increased autophagy, and death by 12-17 months of age. These mice also have elevated levels of clonally expanded mitochondrial DNA (mtDNA) deletions in their tissues. Our results provide direct genetic evidence linking mitochondrial protein quality control to mtDNA deletions and aging in mammals.

  17. Sudden power loss in a HeartMate II left ventricular assist device due to intermittent pin contact with the battery: case report.

    PubMed

    Belway, Dean; Cleland, Mark; Zakutney, Timothy; Grenon, Jackie; Mielniczuk, Lisa M; Hendry, Paul J

    2013-01-01

    Left ventricular assist device technology has improved such that mechanical malfunction, particularly with newer generation continuous flow devices, is a relatively rare event. We present a case of sudden power loss in a HeartMate II caused by intermittent contact of the battery terminals after a clip was dropped with the battery inserted in it. The clip was replaced and the patient made a complete recovery. A new inspection and testing methodology, and amended approach to patient and caregiver training, designed to prevent future occurrences is described.

  18. 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.

  19. Development of the Self-Powered Extravehicular Mobility Unit Extravehicular Activity Data Recorder

    NASA Technical Reports Server (NTRS)

    Bernard, Craig; Hill, Terry R.; Murray, Sean; Wichowski, Robert; Rosenbush, David

    2012-01-01

    The Self-Powered Extravehicular Mobility Unit (EMU) Extravehicular Activity (EVA) Data Recorder (SPEEDR) is a field-programmable gate array (FPGA)-based device designed to collect high-rate EMU Primary Life Support Subsystem (PLSS) data for download at a later time. During EVA, the existing EMU PLSS data downlink capability is one data packet every 2 minutes and is subject to bad packets or loss of signal. Higher-rate PLSS data is generated by the Enhanced Caution and Warning System but is not normally captured or distributed. Access to higher-rate data will increase the capability of EMU anomaly resolution team to pinpoint issues remotely, saving crew time by reducing required call-down Q&A and on-orbit diagnostic activities. With no Space Shuttle flights post Fiscal Year 2011 (FY11), and potentially limited down-mass capability, the ISS crew and ground support personnel will have to be capable of on-orbit operations to maintain, diagnose, repair, and return to service EMU hardware, possibly through 2028. Collecting high-rate EMU PLSS data during both intravehicular activity (IVA) and EVA operations will provide trending analysis for life extension and/or predictive performance. The SPEEDR concept has generated interest as a tool/technology that could be used for other International Space Station subsystems or future exploration-class space suits where hardware reliability/availability is critical and low/variable bandwidth may require store then forward methodology. Preliminary work in FY11 produced a functional prototype consisting of an FPGA evaluation board, custom memory/interface circuit board, and custom software. The SPEEDR concept includes a stand-alone battery that is recharged by a computer Universal Serial Bus (USB) port while data are being downloaded.

  20. Proton exchange membrane fuel cell model for aging predictions: Simulated equivalent active surface area loss and comparisons with durability tests

    NASA Astrophysics Data System (ADS)

    Robin, C.; Gérard, M.; Quinaud, M.; d'Arbigny, J.; Bultel, Y.

    2016-09-01

    The prediction of Proton Exchange Membrane Fuel Cell (PEMFC) lifetime is one of the major challenges to optimize both material properties and dynamic control of the fuel cell system. In this study, by a multiscale modeling approach, a mechanistic catalyst dissolution model is coupled to a dynamic PEMFC cell model to predict the performance loss of the PEMFC. Results are compared to two 2000-h experimental aging tests. More precisely, an original approach is introduced to estimate the loss of an equivalent active surface area during an aging test. Indeed, when the computed Electrochemical Catalyst Surface Area profile is fitted on the experimental measures from Cyclic Voltammetry, the computed performance loss of the PEMFC is underestimated. To be able to predict the performance loss measured by polarization curves during the aging test, an equivalent active surface area is obtained by a model inversion. This methodology enables to successfully find back the experimental cell voltage decay during time. The model parameters are fitted from the polarization curves so that they include the global degradation. Moreover, the model captures the aging heterogeneities along the surface of the cell observed experimentally. Finally, a second 2000-h durability test in dynamic operating conditions validates the approach.

  1. Self-Driven Droplet Powered By Active Nematics

    NASA Astrophysics Data System (ADS)

    Gao, Tong; Li, Zhaorui; Shelley, Michael

    2016-11-01

    Active matter defines a class of emerging bio-inspired materials composed of self-driven micro-particles and far away from equilibrium. Their anormalous physical properties and the means to control them, suggest novel methods in mixing/separation, micro-pumps and motors, self-healing materials etc. The possibility of realizing these applications hinges on a through understanding of the physical mechanisms as well as developing means to manipulate various active systems. By using of a coarse-grained active liquid crystal model, we design and investigate self-driven droplets encapsulating a dense suspension of active particles. We show that a single droplet can be set into motion due to the internal collective motions that are featured by active flows and motile disclination defects. We illustrate that the interplays between the induced directional flows, liquid crystalline structures, and the deformable interface with surface tension can result in tunable mobilities of motile droplets that undergo novel locomotion and rotation.

  2. Experimental investigation on the chemical precipitation generation under the loss of coolant accident of nuclear power plants

    SciTech Connect

    Kim, C. H.; Sung, J. J.; Chung, Y. W.

    2012-07-01

    The PWR containment buildings are designed to facilitate core cooling in the event of a Loss of Coolant Accident (LOCA). The cooling process requires water discharged from the break and containment spray to be collected in a sump for recirculation. The containment sump contains screens to protect the components of the Emergency Core Cooling System (ECCS) and Containment Spray System (CSS) from debris. Since the containment materials may dissolve or corrode when exposed to the reactor coolant and spray solutions, various chemical precipitations can be generated in a post-LOCA environment. These chemical precipitations may become another source of debris loading to be considered in sump screen performance and downstream effects. In this study, new experimental methodology to predict the type and quantity of chemical precipitations has been developed. To generate the plant-specific chemical precipitation in a post-LOCA environment, the plant specific chemical condition of the recirculation sump during post-LOCA is simulated with the experimental reactor for the chemical effect. The plant-specific containment materials are used in the present experiment such as glass fibers, concrete blocks, aluminum specimens, and chemical reagent - boric acid, spray additives or buffering chemicals (sodium hydroxide, Tri-Sodium Phosphate (TSP), or others). The inside temperature of the reactor is controlled to simulate the plant-specific temperature profile of the recirculation sump. The total amount of aluminum released from aluminum specimens is evaluated by ICP-AES analysis to determine the amount of AlOOH and NaAlSi{sub 3}O{sub 8} which induce very adverse effect on the head loss across the sump screens. The amount of these precipitations generated in the present experimental study is compared with the results of WCAP-16530-NP-A. (authors)

  3. Specific Diurnal EMG Activity Pattern Observed in Occlusal Collapse Patients: Relationship between Diurnal Bruxism and Tooth Loss Progression

    PubMed Central

    Kawakami, Shigehisa; Kumazaki, Yohei; Manda, Yosuke; Oki, Kazuhiro; Minagi, Shogo

    2014-01-01

    Aim The role of parafunctional masticatory muscle activity in tooth loss has not been fully clarified. This study aimed to reveal the characteristic activity of masseter muscles in bite collapse patients while awake and asleep. Materials and Methods Six progressive bite collapse patients (PBC group), six age- and gender-matched control subjects (MC group), and six young control subjects (YC group) were enrolled. Electromyograms (EMG) of the masseter muscles were continuously recorded with an ambulatory EMG recorder while patients were awake and asleep. Diurnal and nocturnal parafunctional EMG activity was classified as phasic, tonic, or mixed using an EMG threshold of 20% maximal voluntary clenching. Results Highly extended diurnal phasic activity was observed only in the PBC group. The three groups had significantly different mean diurnal phasic episodes per hour, with 13.29±7.18 per hour in the PBC group, 0.95±0.97 per hour in the MC group, and 0.87±0.98 per hour in the YC group (p<0.01). ROC curve analysis suggested that the number of diurnal phasic episodes might be used to predict bite collapsing tooth loss. Conclusion Extensive bite loss might be related to diurnal masticatory muscle parafunction but not to parafunction during sleep. Clinical Relevance: Scientific rationale for study Although mandibular parafunction has been implicated in stomatognathic system breakdown, a causal relationship has not been established because scientific modalities to evaluate parafunctional activity have been lacking. Principal findings This study used a newly developed EMG recording system that evaluates masseter muscle activity throughout the day. Our results challenge the stereotypical idea of nocturnal bruxism as a strong destructive force. We found that diurnal phasic masticatory muscle activity was most characteristic in patients with progressive bite collapse. Practical implications The incidence of diurnal phasic contractions could be used for the prognostic

  4. SARM1-specific motifs in the TIR domain enable NAD+ loss and regulate injury-induced SARM1 activation.

    PubMed

    Summers, Daniel W; Gibson, Daniel A; DiAntonio, Aaron; Milbrandt, Jeffrey

    2016-10-11

    Axon injury in response to trauma or disease stimulates a self-destruction program that promotes the localized clearance of damaged axon segments. Sterile alpha and Toll/interleukin receptor (TIR) motif-containing protein 1 (SARM1) is an evolutionarily conserved executioner of this degeneration cascade, also known as Wallerian degeneration; however, the mechanism of SARM1-dependent neuronal destruction is still obscure. SARM1 possesses a TIR domain that is necessary for SARM1 activity. In other proteins, dimerized TIR domains serve as scaffolds for innate immune signaling. In contrast, dimerization of the SARM1 TIR domain promotes consumption of the essential metabolite NAD(+) and induces neuronal destruction. This activity is unique to the SARM1 TIR domain, yet the structural elements that enable this activity are unknown. In this study, we identify fundamental properties of the SARM1 TIR domain that promote NAD(+) loss and axon degeneration. Dimerization of the TIR domain from the Caenorhabditis elegans SARM1 ortholog TIR-1 leads to NAD(+) loss and neuronal death, indicating these activities are an evolutionarily conserved feature of SARM1 function. Detailed analysis of sequence homology identifies canonical TIR motifs as well as a SARM1-specific (SS) loop that are required for NAD(+) loss and axon degeneration. Furthermore, we identify a residue in the SARM1 BB loop that is dispensable for TIR activity yet required for injury-induced activation of full-length SARM1, suggesting that SARM1 function requires multidomain interactions. Indeed, we identify a physical interaction between the autoinhibitory N terminus and the TIR domain of SARM1, revealing a previously unrecognized direct connection between these domains that we propose mediates autoinhibition and activation upon injury.

  5. SARM1-specific motifs in the TIR domain enable NAD+ loss and regulate injury-induced SARM1 activation

    PubMed Central

    Summers, Daniel W.; Gibson, Daniel A.; DiAntonio, Aaron; Milbrandt, Jeffrey

    2016-01-01

    Axon injury in response to trauma or disease stimulates a self-destruction program that promotes the localized clearance of damaged axon segments. Sterile alpha and Toll/interleukin receptor (TIR) motif-containing protein 1 (SARM1) is an evolutionarily conserved executioner of this degeneration cascade, also known as Wallerian degeneration; however, the mechanism of SARM1-dependent neuronal destruction is still obscure. SARM1 possesses a TIR domain that is necessary for SARM1 activity. In other proteins, dimerized TIR domains serve as scaffolds for innate immune signaling. In contrast, dimerization of the SARM1 TIR domain promotes consumption of the essential metabolite NAD+ and induces neuronal destruction. This activity is unique to the SARM1 TIR domain, yet the structural elements that enable this activity are unknown. In this study, we identify fundamental properties of the SARM1 TIR domain that promote NAD+ loss and axon degeneration. Dimerization of the TIR domain from the Caenorhabditis elegans SARM1 ortholog TIR-1 leads to NAD+ loss and neuronal death, indicating these activities are an evolutionarily conserved feature of SARM1 function. Detailed analysis of sequence homology identifies canonical TIR motifs as well as a SARM1-specific (SS) loop that are required for NAD+ loss and axon degeneration. Furthermore, we identify a residue in the SARM1 BB loop that is dispensable for TIR activity yet required for injury-induced activation of full-length SARM1, suggesting that SARM1 function requires multidomain interactions. Indeed, we identify a physical interaction between the autoinhibitory N terminus and the TIR domain of SARM1, revealing a previously unrecognized direct connection between these domains that we propose mediates autoinhibition and activation upon injury. PMID:27671644

  6. Extravehicular Activity (EVA) Power, Avionics, and Software (PAS) 101

    NASA Technical Reports Server (NTRS)

    Irimies, David

    2011-01-01

    EVA systems consist of a spacesuit or garment, a PLSS, a PAS system, and spacesuit interface hardware. The PAS system is responsible for providing power for the suit, communication of several types of data between the suit and other mission assets, avionics hardware to perform numerous data display and processing functions, and information systems that provide crewmembers data to perform their tasks with more autonomy and efficiency. Irimies discussed how technology development efforts have advanced the state-of-the-art in these areas and shared technology development challenges.

  7. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    SciTech Connect

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; Phillips, C. K.; Berry, L.; Bonoli, P. T.; Gerhardt, S. P.; Green, D.; LeBlanc, B.; Perkins, R. J.; Qin, C. M.; Pinsker, R. I.; Prater, R.; Ryan, P. M.; Taylor, G.; Valeo, E. J.; Wilson, J. R.; Wright, J. C.; Zhang, X. J.

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSA results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.

  8. Full wave simulations of fast wave efficiency and power losses in the scrape-off layer of tokamak plasmas in mid/high harmonic and minority heating regimes

    DOE PAGES

    Bertelli, N.; Jaeger, E. F.; Hosea, J. C.; ...

    2015-12-17

    Here, several experiments on different machines and in different fast wave (FW) heating regimes, such as hydrogen minority heating and high harmonic fast waves (HHFW), have found strong interaction between radio-frequency (RF) waves and the scrape-off layer (SOL) region. This paper examines the propagation and the power loss in the SOL by using the full wave code AORSA, in which the edge plasma beyond the last closed flux surface (LCFS) is included in the solution domain and a collisional damping parameter is used as a proxy to represent the real, and most likely nonlinear, damping processes. 2D and 3D AORSAmore » results for the National Spherical Torus eXperiment (NSTX) have shown a strong transition to higher SOL power losses (driven by the RF field) when the FW cut-off is removed from in front of the antenna by increasing the edge density. Here, full wave simulations have been extended for 'conventional' tokamaks with higher aspect ratios, such as the DIII-D, Alcator C-Mod, and EAST devices. DIII-D results in HHFW regime show similar behavior found in NSTX and NSTX-U, consistent with previous DIII-D experimental observations. In contrast, a different behavior has been found for C-Mod and EAST, which operate in the minority heating regime.« less

  9. Low replacement doses of thyroxine during food restriction restores type 1 deiodinase activity in rats and promotes body protein loss.

    PubMed

    Araujo, Renata Lopes; de Andrade, Bruno Moulin; de Figueiredo, Alvaro Souto Padron; da Silva, Monique Leandro; Marassi, Michelle Porto; Pereira, Valmara dos Santos; Bouskela, Eliete; Carvalho, Denise P

    2008-07-01

    During food restriction, decreased basal metabolic rate secondary to reduced serum thyroid hormones levels contributes to weight loss resistance. Thyroxine (T(4)) and 3,3',5-tri-iodothyronine (T(3)) administration during caloric restriction produce deleterious side effects; however, the administration of physiological doses of T(4) during food restriction has never been evaluated. The aim of this study was to analyze the effects of low replacement doses of T(4) in Wistar rats subjected to 40% food restriction. Food restriction for 30 days led to significantly reduced liver type 1 deiodinase activity, serum TSH, leptin, T(4), T(3), metabolic rate, and body mass. The significant reduction in hepatic deiodinase activity found during food restriction was normalized in a dose-dependent manner by T(4) replacement, showing that decreased type 1 deiodinase (D1) activity is secondary to decreased serum thyroid hormone levels during caloric restriction. The lowest replacement dose of T(4) did not normalize resting metabolic rate, but was able to potentiate the effects of food restriction on carcass fat loss and did not spare body protein. The highest dose of T(4) produced a normalization of daily oxygen consumption and determined a significant reduction in both carcass fat and protein content. Our results show that serum T(4) normalization during food restriction restores serum T(3) and liver D1 activity, while body protein is not spared. Thus, decreased serum T(4) during caloric restriction corresponds to a protective mechanism to avoid body protein loss, highlighting the importance of other strategies to reduce body mass without lean mass loss.

  10. Increased activity of osteocyte autophagy in ovariectomized rats and its correlation with oxidative stress status and bone loss

    SciTech Connect

    Yang, Yuehua Zheng, Xinfeng Li, Bo Jiang, Shengdan Jiang, Leisheng

    2014-08-15

    Highlights: • Examine autophagy level in the proximal tibia of ovariectomized rats. • Investigate whether autophagy level is associated with bone loss. • Investigate whether autophagy level is associated with oxidative stress status. - Abstract: Objectives: The objectives of the present study were to investigate ovariectomy on autophagy level in the bone and to examine whether autophagy level is associated with bone loss and oxidative stress status. Methods: 36 female Sprague–Dawley rats were randomly divided into sham-operated (Sham), and ovariectomized (OVX) rats treated either with vehicle or 17-β-estradiol. At the end of the six-week treatment, bone mineral density (BMD) and bone micro-architecture in proximal tibias were assessed by micro-CT. Serum 17β-estradiol (E2) level were measured. Total antioxidant capacity (T-AOC), superoxide dismutase (SOD) activity, catalase (CAT) activity in proximal tibia was also determined. The osteocyte autophagy in proximal tibias was detected respectively by Transmission Electron Microscopy (TEM), immunofluorescent histochemistry (IH), realtime-PCR and Western blot. In addition, the spearman correlation between bone mass, oxidative stress status, serum E2 and autophagy were analyzed. Results: Ovariectomy increased Atg5, LC3, and Beclin1 mRNA and proteins expressions while decreased p62 expression. Ovariectomy also declined the activities of T-AOC, CAT, and SOD. Treatment with E2 prevented the reduction in bone mass as well as restored the autophagy level. Furthermore, LC3-II expression was inversely correlated with T-AOC, CAT, and SOD activities. A significant inverse correlation between LC3-II expression and BV/TV, Tb.N, BMD in proximal tibias was found. Conclusions: Ovariectomy induced oxidative stress, autophagy and bone loss. Autophagy of osteocyte was inversely correlated with oxidative stress status and bone loss.

  11. Loss of C9orf72 Enhances Autophagic Activity via Deregulated mTOR and TFEB Signaling

    PubMed Central

    Conchina, Karen; Chu, Justin; Nirujogi, Raja Sekhar; Brady, Nathan R.; Hamacher-Brady, Anne

    2016-01-01

    The most common cause of the neurodegenerative diseases amyotrophic lateral sclerosis and frontotemporal dementia is a hexanucleotide repeat expansion in C9orf72. Here we report a study of the C9orf72 protein by examining the consequences of loss of C9orf72 functions. Deletion of one or both alleles of the C9orf72 gene in mice causes age-dependent lethality phenotypes. We demonstrate that C9orf72 regulates nutrient sensing as the loss of C9orf72 decreases phosphorylation of the mTOR substrate S6K1. The transcription factor EB (TFEB), a master regulator of lysosomal and autophagy genes, which is negatively regulated by mTOR, is substantially up-regulated in C9orf72 loss-of-function animal and cellular models. Consistent with reduced mTOR activity and increased TFEB levels, loss of C9orf72 enhances autophagic flux, suggesting that C9orf72 is a negative regulator of autophagy. We identified a protein complex consisting of C9orf72 and SMCR8, both of which are homologous to DENN-like proteins. The depletion of C9orf72 or SMCR8 leads to significant down-regulation of each other’s protein level. Loss of SMCR8 alters mTOR signaling and autophagy. These results demonstrate that the C9orf72-SMCR8 protein complex functions in the regulation of metabolism and provide evidence that loss of C9orf72 function may contribute to the pathogenesis of relevant diseases. PMID:27875531

  12. Final report on fiscal year 1992 activities for the environmental monitors line-loss study

    SciTech Connect

    Kenoyer, J.L.

    1993-12-09

    The work performed on this Environmental Monitors Line-Loss Study has been performed under Contract Numbers MLW-SVV-073750 and MFH-SVV-207554. Work on the task was initiated mid-December 1991, and this report documents and summarizes the work performed through January 18, 1993. The sections included in this report summarize the work performed on the Environmental Monitors Line-Loss Study. The sections included in this report are arranged to reflect individual sub-tasks and include: descriptions of measurement systems and procedures used to obtain cascade impactor samples and laser spectrometer measurements from multiple stacks and locations; information on data acquisition, analyses, assessment, and software; discussion of the analyses and measurement results from the cascade impactor and laser spectrometer systems and software used; discussion on the development of general test methods and procedures for line-loss determinations; an overall summary and specific conclusions that can be made with regard to efforts performed on this task during FY 1992 and FY 1993. Supporting information for these sections is included in this report as appendices.

  13. Stepping towards prevention of bone loss after stroke: a systematic review of the skeletal effects of physical activity after stroke.

    PubMed

    Borschmann, Karen; Pang, Marco Y C; Bernhardt, Julie; Iuliano-Burns, Sandra

    2012-06-01

    Bone loss after stroke is pronounced, and contributes to increased fracture risk. People who fracture after stroke experience reduced mobility and increased mortality. Physical activity can maintain or improve bone mineral density and structure in healthy older adults, likely reducing fracture risk. The purpose of this systematic review was to investigate the skeletal effects of physical activity in adults affected by stroke. A search of electronic databases was undertaken. Selection criteria of trials were • prospective and controlled • physical activity-based intervention • participants with history of stroke, and • bone-related outcome measures. Effect sizes were calculated for outcomes of paretic and nonparetic limbs. Three of 349 identified records met the inclusion criteria. Small effect sizes were found in favor of physical activity in adults with chronic stroke (n=95, 40% female, average age 63·8 years, more than one-year poststroke). Patients in intervention groups had significantly higher changes in femoral neck bone mineral density, tibial cortical thickness and trabecular bone mineral content of the paretic limb, compared with controls (P<0·05). It is not known whether these benefits reduced fracture risk. There are limited studies investigating the skeletal effect of physical activity for adults poststroke. Given the increased risk of, and poor outcomes following a fracture after stroke, randomized trials are warranted to investigate the benefits of physical activity on bone, after stroke. Interventions are likely to be beneficial if implemented soon after stroke, when bone loss appears to be rapid and pronounced.

  14. A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation.

    PubMed

    Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-Hong; Zhang, Hong; Sun, Mingui

    2015-04-01

    In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle.

  15. A Low Power, Parallel Wearable Multi-Sensor System for Human Activity Evaluation

    PubMed Central

    Li, Yuecheng; Jia, Wenyan; Yu, Tianjian; Luan, Bo; Mao, Zhi-hong; Zhang, Hong; Sun, Mingui

    2015-01-01

    In this paper, the design of a low power heterogeneous wearable multi-sensor system, built with Zynq System-on-Chip (SoC), for human activity evaluation is presented. The powerful data processing capability and flexibility of this SoC represent significant improvements over our previous ARM based system designs. The new system captures and compresses multiple color images and sensor data simultaneously. Several strategies are adopted to minimize power consumption. Our wearable system provides a new tool for the evaluation of human activity, including diet, physical activity and lifestyle. PMID:26185409

  16. Activated region fitting: a robust high-power method for fMRI analysis using parameterized regions of activation.

    PubMed

    Weeda, Wouter D; Waldorp, Lourens J; Christoffels, Ingrid; Huizenga, Hilde M

    2009-08-01

    An important issue in the analysis of fMRI is how to account for the spatial smoothness of activated regions. In this article a method is proposed to accomplish this by modeling activated regions with Gaussian shapes. Hypothesis tests on the location, spatial extent, and amplitude of these regions are performed instead of hypothesis tests of individual voxels. This increases power and eases interpretation. Simulation studies show robust hypothesis tests under misspecification of the shape model, and increased power over standard techniques especially at low signal-to-noise ratios. An application to real single-subject data also indicates that the method has increased power over standard methods.

  17. Treadmill exercise prevents GABAergic neuronal loss with suppression of neuronal activation in the pilocarpine-induced epileptic rats

    PubMed Central

    Lim, Baek-Vin; Shin, Mal-Soon; Lee, Jae-Min; Seo, Jin-Hee

    2015-01-01

    Epilepsy is a common neurological disorder characterized by seizure and loss of neuronal cells by abnormal rhythmic firing of neurons in the brain. In the present study, we investigated the effect of treadmill exercise on gamma-aminobutyric acid (GABA)ergic neuronal loss in relation with neuronal activation using pilocarpine-induced epileptic rats. The rats were divided into four groups: control group, control and treadmill exercise group, pilocarpine-induced epilepsy group, and pilocarpine-induced epilepsy and treadmill exercise group. Epilepsy was induced by intraperitoneal injection of 320 mg/kg pilocarpine hydrochloride. The rats in the exercise groups were forced to run on a motorized treadmill for 30 min once a day for 2 weeks. In the present results, neuronal loss in the hippocampal CA1 region was increased after pilocarpine-induced seizure. Treadmill exercise inhibited hippocampal neuronal loss in the epileptic rats. Glutamic acid decarboxylase (GAD67) expression in the hippocampal CA1 region was reduced by pilocarpine-induced seizure. Treadmill exercise increased GAD67 expression in the epileptic rats. c-Fos expression in the hippocampal CA1 region was increased in response to epileptic seizure. Treadmill exercise inhibited c-Fos expression in the epileptic rats. Epileptic seizure increased brain-derived neurotrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) expressions in the hippocampus. Treadmill exercise suppressed BDNF and TrkB expressions in the epileptic rats. In the present study, treadmill exercise prevented GABAergic neuronal loss and inhibited neuronal activation in the hippocampal CA1 region through the down-regulation of BDNF-TrkB signaling pathway. PMID:25960980

  18. The relative importance of respiratory water loss in scorpions is correlated with species habitat type and activity pattern.

    PubMed

    Gefen, Eran

    2011-01-01

    Scorpions exhibit some of the lowest recorded water loss rates compared with those of other terrestrial arthropods of similar body size. Evaporative water loss (EWL) includes cuticular transpiration and respiratory water loss (RWL) from gas exchange surfaces, that is, book lung lamellae. Estimated fractions of cuticular and respiratory losses currently available from the literature show considerable variation, at least partly as a result of differences in methodology. This study reports RWL rates and their relative importance in scorpions from two families (Buthidae and Scorpionidae), including both xeric and mesic species (or subspecies). Two of the included Buthidae were surface-dwelling species, and another inhabits empty burrows of other terrestrial arthropods. This experimental design enabled correlating RWL importance with scorpion phylogeny, habitat type, and/or homing behavior. Buthidae species exhibited significantly lower EWL rates compared with those of Scorpionidae, whereas effects of habitat type and homing behavior were not significant. Resting RWL rates were not significantly affected by scorpion phylogeny, but rates for the xeric species (totaling ~10% of EWL rates at 30°C) were significantly lower compared with those of mesic species. These lower RWL values were correlated with significantly lower H(2)O/CO(2) emission rates in xeric species. The experimental setup and ~24-h duration of each individual recording allowed estimating the effect of interspecific variation in activity on RWL proportions. The high respiratory losses in active hydrated Scorpio maurus fuscus, totaling 30% of EWL, suggest that behavioral discretion in this species is a more likely mechanism for body water conservation under stressful conditions when compared with the responses of other studied species.

  19. Proposal for Wireless Power Distribution System with Capacitive Coupling Using One-Pulse Switching Active Capacitor

    NASA Astrophysics Data System (ADS)

    Funato, Hirohito; Chiku, Yuki; Harakawa, Ken-Ichi

    Wireless electric power distribution is an attractive means of supplying power to mobile equipment such as mobile phones and electric vehicles. Magnetic field coupling is the most popular method for wireless power distribution. However, this method has certain disadvantages such as power decrease in the case of inexact placement of couplings. Wireless power distribution with capacitive coupling has been proposed to overcome the disadvantages of wireless power distribution with magnetic field coupling. It is, however, difficult to transfer high power owing to the small capacitance of capacitive coupling. The authors propose a new power converter suitable for wireless power distribution with capacitive coupling using a novel one-pulse switching active capacitor (OPSAC) to enhance power transfer. The proposed system improves the power transfer efficiency without LC resonance and is hence robust to parameter change. In this paper, a wireless power distribution system with improved OPSAC (I-OPSAC) is proposed. In the I-OPSAC, the dc voltage source for the inverter is replaced by a capacitor because the OPSAC behaves like a reactive element. The I-OPSAC shows stable operation without any feedback loop including dc capacitor voltage control. In this paper, a control scheme and the detailed operational characteristics are reported, in addition to the simulations and experimental results.

  20. Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae).

    PubMed

    Ruhland, Fanny; Chiara, Violette; Trabalon, Marie

    2016-11-01

    Wolf spiders' (Lycosidae) maternal behaviour includes a specific phase called "egg brooding" which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers' exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos' developmental stage) on vagrant wolf spider Pardosa saltans females' exploration and locomotion. We observed these spiders' maternal behaviour in the laboratory and evaluated their locomotor activity using a digital activity recording device. Our subjects were virgin females (without egg-sac) and first time mothers (with her egg-sac) who were divided into three groups. The first group of mothers were tested on the day the egg-sac was built (day 0), and the females of the other two groups were tested 10 or 15days after they had built their egg-sac. We evaluated the effects of the presence and the loss of egg-sac on mothers' activity. Pardosa saltans females' behaviour depended on mothers' physiological state and/or age of egg-sac (developmental stage of embryos). Virgin females' behaviour was not modified by the presence of an egg-sac in their environment. Mothers' reactions to the presence, the loss and the recovery of their egg-sac varied during the maternal cycle. Maternal behaviour changed with age of egg-sac, but the levels of locomotor activity of mothers with egg-sacs was similar to those of virgin females. Loss of egg-sac modified the maternal behaviour and locomotor activity of all mothers; these modifications were greater on "day 15" when embryos had emerged from eggs. All mothers were able to retrieve their egg-sacs and to re-attach them to their spinnerets.

  1. Activity/participation Limitation and Weight Loss Among Overweight and Obese US Adults: 1999 to 2002 NHANES

    PubMed Central

    Bish, Connie L.; Blanck, Heidi Michels; Maynard, L. Michele; Serdula, Mary K.; Thompson, Nancy J.; Khan, Laura Kettel

    2007-01-01

    Objective To examine the prevalence and association of activity/participation limitation with trying to lose weight and weight loss practices (eating fewer calories, physical activity, or both) among overweight and obese adults in the United States. Research Methods and Procedures Eligible adults were 20 years of age or older with a body mass index (BMI) ≥ 25 kg/m2 (n = 5608) who responded to standard physical functioning questions included in the 1999–2002 National Health and Nutrition Examination Survey, a continuous survey of the civilian non-institutionalized US population. Results Obese (BMI ≥ 30) men with vs. without activity/participation limitations were more likely to try to lose weight (OR = 1.59, 95% CI 1.05–2.41). This was not the case for overweight women and men (BMI 25–29.9), or obese women. Among adults trying to lose weight, reducing calorie consumption was common (63%–73%, men, 67%–76%, women). Overweight women with vs without activity/participation limitations had significantly reduced likelihood of attaining recommended physical activity (OR = 0.56, 95% CI 0.36–0.89). Obese adults were more likely to try to lose weight if they attributed their limitation to body weight (OR = 1.78, 95% CI 1.11–2.88) or diabetes (OR = 1.86, 95% CI 1.01–3.43) compared to other causes. Overweight and obese adults who attributed activity/participation limitations to mental health, musculoskeletal, or cardiovascular problems were equally likely to attempt weight loss when respondents with each condition were compared to respondents without the condition. Discussion These results verify the importance of adequate subjective health assessment when developing individual weight loss plans, and may help guide weight management professionals in the development and delivery of more personalized care. PMID:18092069

  2. Activation Cross Sections Improvements needed for IFE Power Reactors Designs

    SciTech Connect

    Rodriguez, A; Cabellos, O; Sanz, J; FalQuina, R; Latkowski, J; Reyes, S

    2003-10-02

    Uncertainties in the prediction of the neutron induced long-lived activity in the natural elements from H to Bi due to activation cross section uncertainties are estimated assuming as neutron environment those of the HYLIFE-II and Sombrero vessel structures. The latest available activation cross section data are employed. The random variables used in the uncertainty analysis have been the concentration limits (CL's) corresponding to hands-on recycling, remote recycling and shallow land burial, quantities typically considered in ranking elements under waste management considerations. The CL standard value (CL{sub nom}), i.e. without uncertainties, is compared with the 95th percentile CL value (CL95). The results of the analysis are very helpful in assessing the quality of the current activation data for IFE applications, providing a rational basis for programmatic priority assignments for new cross sections measurements or evaluations. The HYLIFE-II results shown that a significant error is estimated in predicting the activation of several elements. The estimated errors in the Sombrero case are much less important.

  3. RELAP5/MOD2. 5 analysis of the HFBR (High Flux Beam Reactor) for a loss of power and coolant accident

    SciTech Connect

    Slovik, G.C.; Rohatgi, U.S.; Jo, Jae.

    1990-05-01

    A set of postulated accidents were evaluated for the High Flux Beam Reactor (HFBR) at Brookhaven National Laboratory. A loss of power accident (LOPA) and a loss of coolant accident (LOCA) were analyzed. This work was performed in response to a DOE review that wanted to update the understanding of the thermal hydraulic behavior of the HFBR during these transients. These calculations were used to determine the margins to fuel damage at the 60 MW power level. The LOPA assumes all the backup power systems fail (although this event is highly unlikely). The reactor scrams, the depressurization valve opens, and the pumps coast down. The HFBR has down flow through the core during normal operation. To avoid fuel damage, the core normally goes through an extended period of forced down flow after a scram before natural circulation is allowed. During a LOPA, the core will go into flow reversal once the buoyancy forces are larger than the friction forces produced during the pump coast down. The flow will stagnate, reverse direction, and establish a buoyancy driven (natural circulation) flow around the core. Fuel damage would probably occur if the critical heat flux (CHF) limit is reached during the flow reversal event. The RELAP5/MOD2.5 code, with an option for heavy water, was used to model the HFBR and perform the LOPA calculation. The code was used to predict the time when the buoyancy forces overcome the friction forces and produce upward directed flow in the core. The Monde CHF correlation and experimental data taken for the HFBR during the design verification phase in 1963 were used to determine the fuel damage margin. 20 refs., 40 figs., 11 tabs.

  4. Selenium status, lipid peroxides concentration, and glutathione peroxidase activity in the blood of power station and rubber factory workers.

    PubMed

    Zachara, B A; Wasowicz, W; Sklodowska, M; Gromadzinska, J

    1987-01-01

    Concentration of selenium in whole blood and plasma, lipid peroxides in plasma, and glutathione peroxidase activities in red blood cell hemolysates and plasma were determined in 49 coal power plant workers and in 50 rubber factory workers. The results were compared with those obtained for 58 nonindustrial controls. Whole blood selenium was significantly lower and plasma lipid peroxides were significantly higher in power plant workers when compared to the nonindustrial group. In the rubber factory workers, whole blood selenium and red blood cells and plasma glutathione peroxidase activities were significantly lower than in the control group. Urinary output of selenium was also significantly decreased in rubber factory workers. Slightly elevated lipid peroxides were also observed in that group. It seems reasonable to conclude that the lower blood selenium and decreased urinary output of this element may result from increased loss of selenium with perspiration. No correlation has been observed between selenium concentration and glutathione peroxidase activity and between enzyme activity and lipid peroxides concentration in the industrial group.

  5. Ataxia and hypogonadism caused by the loss of ubiquitin ligase activity of the U box protein CHIP

    PubMed Central

    Shi, Chang-He; Schisler, Jonathan C.; Rubel, Carrie E.; Tan, Song; Song, Bo; McDonough, Holly; Xu, Lei; Portbury, Andrea L.; Mao, Cheng-Yuan; True, Cadence; Wang, Rui-Hao; Wang, Qing-Zhi; Sun, Shi-Lei; Seminara, Stephanie B.; Patterson, Cam; Xu, Yu-Ming

    2014-01-01

    Gordon Holmes syndrome (GHS) is a rare Mendelian neurodegenerative disorder characterized by ataxia and hypogonadism. Recently, it was suggested that disordered ubiquitination underlies GHS though the discovery of exome mutations in the E3 ligase RNF216 and deubiquitinase OTUD4. We performed exome sequencing in a family with two of three siblings afflicted with ataxia and hypogonadism and identified a homozygous mutation in STUB1 (NM_005861) c.737C→T, p.Thr246Met, a gene that encodes the protein CHIP (C-terminus of HSC70-interacting protein). CHIP plays a central role in regulating protein quality control, in part through its ability to function as an E3 ligase. Loss of CHIP function has long been associated with protein misfolding and aggregation in several genetic mouse models of neurodegenerative disorders; however, a role for CHIP in human neurological disease has yet to be identified. Introduction of the Thr246Met mutation into CHIP results in a loss of ubiquitin ligase activity measured directly using recombinant proteins as well as in cell culture models. Loss of CHIP function in mice resulted in behavioral and reproductive impairments that mimic human ataxia and hypogonadism. We conclude that GHS can be caused by a loss-of-function mutation in CHIP. Our findings further highlight the role of disordered ubiquitination and protein quality control in the pathogenesis of neurodegenerative disease and demonstrate the utility of combining whole-exome sequencing with molecular analyses and animal models to define causal disease polymorphisms. PMID:24113144

  6. Removing Cool Cores and Central Metallicity Peaks in Galaxy Clusters with Powerful Active Galactic Nucleus Outbursts

    NASA Astrophysics Data System (ADS)

    Guo, Fulai; Mathews, William G.

    2010-07-01

    Recent X-ray observations of galaxy clusters suggest that cluster populations are bimodally distributed according to central gas entropy and are separated into two distinct classes: cool core (CC) and non-cool core (NCC) clusters. While it is widely accepted that active galactic nucleus (AGN) feedback plays a key role in offsetting radiative losses and maintaining many clusters in the CC state, the origin of NCC clusters is much less clear. At the same time, a handful of extremely powerful AGN outbursts have recently been detected in clusters, with a total energy ~1061-1062 erg. Using two-dimensional hydrodynamic simulations, we show that if a large fraction of this energy is deposited near the centers of CC clusters, which is likely common due to dense cores, these AGN outbursts can completely remove CCs, transforming them to NCC clusters. Our model also has interesting implications for cluster abundance profiles, which usually show a central peak in CC systems. Our calculations indicate that during the CC to NCC transformation, AGN outbursts efficiently mix metals in cluster central regions and may even remove central abundance peaks if they are not broad enough. For CC clusters with broad central abundance peaks, AGN outbursts decrease peak abundances, but cannot effectively destroy the peaks. Our model may simultaneously explain the contradictory (possibly bimodal) results of abundance profiles in NCC clusters, some of which are nearly flat, while others have strong central peaks similar to those in CC clusters. A statistical analysis of the sizes of central abundance peaks and their redshift evolution may shed interesting insights on the origin of both types of NCC clusters and the evolution history of thermodynamics and AGN activity in clusters.

  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. Loss of Ribosomal Protein L11 Blocks Stress Activation of the Bacillus subtilis Transcription Factor ςB

    PubMed Central

    Zhang, Shuyu; Scott, Janelle M.; Haldenwang, W. G.

    2001-01-01

    ςB, the general stress response sigma factor of Bacillus subtilis, is activated when the cell's energy levels decline or the bacterium is exposed to environmental stress (e.g., heat shock, ethanol). Physical stress activates ςB through a collection of regulatory kinases and phosphatases (the Rsb proteins) which catalyze the release of ςB from an anti-ςB factor inhibitor. The means by which diverse stresses communicate with the Rsb proteins is unknown; however, a role for the ribosome in this process was suggested when several of the upstream members of the ςB stress activation cascade (RsbR, -S, and -T) were found to cofractionate with ribosomes in crude B. subtilis extracts. We now present evidence for the involvement of a ribosome-mediated process in the stress activation of ςB. B. subtilis strains resistant to the antibiotic thiostrepton, due to the loss of ribosomal protein L11 (RplK), were found to be blocked in the stress activation of ςB. Neither the energy-responsive activation of ςB nor stress-dependent chaperone gene induction (a ςB-independent stress response) was inhibited by the loss of L11. The Rsb proteins required for stress activation of ςB are shown to be active in the RplK− strain but fail to be triggered by stress. The data demonstrate that the B. subtilis ribosomes provide an essential input for the stress activation of ςB and suggest that the ribosomes may themselves be the sensors for stress in this system. PMID:11244072

  9. Correlation of Conformational Changes and Protein Degradation with Loss of Lysozyme Activity Due to Chlorine Dioxide Treatment.

    PubMed

    Ooi, Beng Guat; Branning, Sharon Alyssa

    2016-12-13

    Chlorine dioxide (ClO2) is a potent oxidizing agent used for the treatment of drinking water and decontamination of facilities and equipment. The purpose of this research is to elucidate the manner in which ClO2 destroys proteins by studying the effects of ClO2 on lysozyme. The degree of enzyme activity lost can be correlated to the treatment time and levels of the ClO2 used. Lysozyme activity was drastically reduced to 45.3% of original enzyme activity when exposed to 4.3 mM ClO2 in the sample after 3 h. Almost all activities were lost in 3 h after exposure to higher ClO2 concentrations of up to 16.8 and 21.9 mM. Changes in protein conformation and amount as a result of ClO2 treatment were determined using the Raman spectroscopy and gel electrophoresis. Raman shifts and the alteration of spectral features observed in the ClO2-treated lysozyme samples are associated with loss of the α-helix secondary structure, tertiary structure, and disulfide bond. Progressive degradation of the denatured lysozyme by increasing levels of chlorine dioxide was also observed in gel electrophoresis. Hence, ClO2 can effectively cause protein denaturation and degradation resulting in loss of enzyme activity.

  10. Longitudinal decline of lower extremity muscle power in healthy and mobility-limited older adults: influence of muscle mass, strength, composition, neuromuscular activation and single fiber contractile properties

    PubMed Central

    Reid, Kieran F.; Pasha, Evan; Doros, Gheorghe; Clark, David J.; Patten, Carolynn; Phillips, Edward M.; Frontera, Walter R.; Fielding, Roger A.

    2013-01-01

    Purpose This longitudinal study examined the major physiological mechanisms that determine the age-related loss of lower extremity muscle power in two distinct groups of older humans. We hypothesized that after ~ 3 years of follow-up, mobility-limited older adults (mean age: 77.2 ± 4, n = 22, 12 females) would have significantly greater reductions in leg extensor muscle power compared to healthy older adults (74.1 ± 4, n = 26, 12 females). Methods Mid-thigh muscle size and composition were assessed using computed tomography. Neuromuscular activation was quantified using surface electromyography and vastus lateralis single muscle fibers were studied to evaluate intrinsic muscle contractile properties. Results At follow-up, the overall magnitude of muscle power loss was similar between groups: mobility-limited: −8.5% vs. healthy older: −8.8%, P > 0.8. Mobility-limited elders had significant reductions in muscle size (−3.8%, P< 0.01) and strength (−5.9%, P< 0.02), however, these parameters were preserved in healthy older (P ≥ 0.7). Neuromuscular activation declined significantly within healthy older but not in mobility-limited participants. Within both groups, the cross sectional areas of type I and type IIA muscle fibers were preserved while substantial increases in single fiber peak force ( > 30%), peak power (> 200%) and unloaded shortening velocity (>50%) were elicited at follow-up. Conclusion Different physiological mechanisms contribute to the loss of lower extremity muscle power in healthy older and mobility-limited older adults. Neuromuscular changes may be the critical early determinant of muscle power deficits with aging. In response to major whole muscle decrements, major compensatory mechanisms occur within the contractile properties of surviving single muscle fibers in an attempt to restore overall muscle power and function with advancing age. PMID:24122149

  11. 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…

  12. 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.

  13. 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...Power would be able to choose the duty rate during customs entry procedures that applies to the...

  14. Loss and Gain of Human Acidic Mammalian Chitinase Activity by Nonsynonymous SNPs

    PubMed Central

    Okawa, Kazuaki; Ohno, Misa; Kashimura, Akinori; Kimura, Masahiro; Kobayashi, Yuki; Sakaguchi, Masayoshi; Sugahara, Yasusato; Kamaya, Minori; Kino, Yoshihiro; Bauer, Peter O.; Oyama, Fumitaka

    2016-01-01

    Acidic mammalian chitinase (AMCase) is implicated in asthma, allergic inflammation, and food processing. Little is known about genetic and evolutional regulation of chitinolytic activity of AMCase. Here, we relate human AMCase polymorphisms to the mouse AMCase, and show that the highly active variants encoded by nonsynonymous single-nucleotide polymorphisms (nsSNPs) are consistent with the mouse AMCase sequence. The chitinolytic activity of the recombinant human AMCase was significantly lower than that of the mouse counterpart. By creating mouse-human chimeric AMCase protein we found that the presence of the N-terminal region of human AMCase containing conserved active site residues reduced the enzymatic activity of the molecule. We were able to significantly increase the activity of human AMCase by amino acid substitutions encoded by nsSNPs (N45, D47, and R61) with those conserved in the mouse homologue (D45, N47, and M61). For abolition of the mouse AMCase activity, introduction of M61R mutation was sufficient. M61 is conserved in most of primates other than human and orangutan as well as in other mammals. Orangutan has I61 substitution, which also markedly reduced the activity of the mouse AMCase, indicating that the M61 is a crucial residue for the chitinolytic activity. Altogether, our data suggest that human AMCase has lost its chitinolytic activity by integration of nsSNPs during evolution and that the enzyme can be reactivated by introducing amino acids conserved in the mouse counterpart. PMID:27702777

  15. A liquid phase based C. elegans behavioral analysis system identifies motor activity loss in a nematode Parkinson's disease model.

    PubMed

    Zheng, Maohua; Gorelenkova, Olga; Yang, Jiong; Feng, Zhaoyang

    2012-03-15

    Motor activity of Caenorhabditis elegans is widely used to study the mechanisms ranging from basic neuronal functions to human neurodegenerative diseases. It may also serve as a paradigm to screen for potential therapeutic reagents treating these diseases. Here, we developed an automated, 96-well plate and liquid phase based system that quantifies nematode motor activity in real time. Using this system, we identified an adult-onset, ageing-associated motor activity loss in a transgenic nematode line expressing human pathogenic G2019S mutant LRRK2 (leucine-rich repeat kinase 2), the leading genetic cause of Parkinson's disease characterized by dopaminergic neurodegeneration associated motor deficient mainly in elder citizens. Thus, our system may be used as a platform to screen for potential therapeutic drugs treating Parkinson's disease. It can also be used to monitor motor activity of nematodes in liquid phase at similar scenario.

  16. Aerobic exercise plus weight loss improves insulin sensitivity and increases skeletal muscle glycogen synthase activity in older men.

    PubMed

    Ryan, Alice S; Katzel, Leslie I; Prior, Steven J; McLenithan, John C; Goldberg, Andrew P; Ortmeyer, Heidi K

    2014-07-01

    The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m(2)). Muscle samples of the vastus lateralis were collected before and during a 3-hour 80 mU/m(2)/min hyperinsulinemic-euglycemic clamp. AEX + WL increased VO2max by 11% (p < .05) and decreased body weight (-9%, p < .001). AEX + WL increased basal citrate synthase activity by 46% (p < .01) and insulin activation of independent (2.9-fold) and fractional (2.3-fold) activities (both p < .001) of glycogen synthase. AEX + WL had no effect on phosphorylation of Akt or AS160. Glucose utilization (M) improved 25% (p < .01), and the change tended to be related to the increase in insulin activation of glycogen synthase fractional activity (r = .50, p = .08) following AEX + WL. In summary, AEX + WL has a robust effect on insulin activation of skeletal muscle glycogen synthase activity that likely contributes to improved glucose utilization in older insulin-resistant men.

  17. Aerobic Exercise Plus Weight Loss Improves Insulin Sensitivity and Increases Skeletal Muscle Glycogen Synthase Activity in Older Men

    PubMed Central

    Katzel, Leslie I.; Prior, Steven J.; McLenithan, John C.; Goldberg, Andrew P.; Ortmeyer, Heidi K.

    2014-01-01

    The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m2). Muscle samples of the vastus lateralis were collected before and during a 3-hour 80 mU/m2/min hyperinsulinemic-euglycemic clamp. AEX + WL increased VO2max by 11% (p < .05) and decreased body weight (−9%, p < .001). AEX + WL increased basal citrate synthase activity by 46% (p < .01) and insulin activation of independent (2.9-fold) and fractional (2.3-fold) activities (both p < .001) of glycogen synthase. AEX + WL had no effect on phosphorylation of Akt or AS160. Glucose utilization (M) improved 25% (p < .01), and the change tended to be related to the increase in insulin activation of glycogen synthase fractional activity (r = .50, p = .08) following AEX + WL. In summary, AEX + WL has a robust effect on insulin activation of skeletal muscle glycogen synthase activity that likely contributes to improved glucose utilization in older insulin-resistant men. PMID:24357038

  18. SALT observations of the chromospheric activity of transiting planet hosts: mass-loss and star-planet interactions★

    NASA Astrophysics Data System (ADS)

    Staab, D.; Haswell, C. A.; Smith, Gareth D.; Fossati, L.; Barnes, J. R.; Busuttil, R.; Jenkins, J. S.

    2017-04-01

    We measured the chromospheric activity of the four hot Jupiter hosts WASP-43, WASP-51/HAT-P-30, WASP-72 and WASP-103 to search for anomalous values caused by the close-in companions. The Mount Wilson Ca II H & K S-index was calculated for each star using observations taken with the Robert Stobie Spectrograph at the Southern African Large Telescope. The activity level of WASP-43 is anomalously high relative to its age and falls among the highest values of all known main-sequence stars. We found marginal evidence that the activity of WASP-103 is also higher than expected from the system age. We suggest that for WASP-43 and WASP-103 star-planet interactions (SPI) may enhance the Ca II H & K core emission. The activity levels of WASP-51/HAT-P-30 and WASP-72 are anomalously low, with the latter falling below the basal envelope for both main-sequence and evolved stars. This can be attributed to circumstellar absorption due to planetary mass-loss, though absorption in the interstellar medium may contribute. A quarter of known short-period planet hosts exhibit anomalously low activity levels, including systems with hot Jupiters and low-mass companions. Since SPI can elevate and absorption can suppress the observed chromospheric activity of stars with close-in planets, their Ca II H & K activity levels are an unreliable age indicator. Systems where the activity is depressed by absorption from planetary mass-loss are key targets for examining planet compositions through transmission spectroscopy.

  19. Loss of vascular fibrinolytic activity following irradiation of the liver - an aspect of late radiation damage

    SciTech Connect

    Henderson, B.W.; Bicher, H.I.; Johnson, R.J.

    1983-09-01

    The vascular fibrinolytic activity, known to originate from the endothelium, was studied histochemically by fibrinolysis autography in liver samples from beagles exposed to radiation treatment. Eighteen to thirty months prior to sacrifice, six dogs received x irradiation (4600 rad in 5 weeks) and three dogs received x irradiation plus aspirin (1 g/kg). Two dogs served as untreated controls. Control livers showed extensive fibrinolytic activity related to large and small vascular structures. The vascular fibrinolytic activity had been lost from all vessels except the major portal branches in five irradiated livers and was severaly diminished in three. One irradiated liver appeared to possess normal fibrinolytic activity.

  20. Membrane permeability and the loss of germination factor from Neurospora crassa at low water activities

    NASA Technical Reports Server (NTRS)

    Charlang, G.; Horowitz, N. H.

    1974-01-01

    Neurospora crassa conidia incubating in buffer at low water activities release a germination-essential component as well as 260-nm absorbing and ninhydrin-positive materials, regardless of whether an electrolyte or nonelectrolyte is used to reduce water activity. Chloroform and antibiotics known to increase cell-membrane permeability have a similar effect. This suggests that membrane damage occurs in media of low water activity and that an increase in permeability is responsible for the release of cellular components. The damage caused in media of low water activity is nonlethal in most cases, and the conidia recover when transferred to nutrient medium.

  1. Premature Sperm Activation and Defective Spermatogenesis Caused by Loss of spe-46 Function in Caenorhabditis elegans

    PubMed Central

    Liau, Wei-Siang; Nasri, Ubaydah; Elmatari, Daniel; Rothman, Jason; LaMunyon, Craig W.

    2013-01-01

    Given limited resources for motility, sperm cell activation must be precisely timed to ensure the greatest likelihood of fertilization. Like those of most species, the sperm of C. elegans become active only after encountering an external signaling molecule. Activation coincides with spermiogenesis, the final step in spermatogenesis, when the spherical spermatid undergoes wholesale reorganization to produce a pseudopod. Here, we describe a gene involved in sperm activation, spe-46. This gene was identified in a suppressor screen of spe-27(it132ts), a sperm-expressed gene whose product functions in the transduction of the spermatid activation signal. While spe-27(it132ts) worms are sterile at 25°C, the spe-46(hc197)I; spe-27(it132ts)IV double mutants regain partial fertility. Single nucleotide polymorphism mapping, whole genome sequencing, and transformation rescue were employed to identify the spe-46 coding sequence. It encodes a protein with seven predicted transmembrane domains but with no other predicted functional domains or homology outside of nematodes. Expression is limited to spermatogenic tissue, and a transcriptional GFP fusion shows expression corresponds with the onset of the pachytene stage of meiosis. The spe-46(hc197) mutation bypasses the need for the activation signal; mutant sperm activate prematurely without an activation signal in males, and mutant males are sterile. In an otherwise wild-type genome, the spe-46(hc197) mutation induces a sperm defective phenotype. In addition to premature activation, spe-46(hc197) sperm exhibit numerous defects including aneuploidy, vacuolization, protruding spikes, and precocious fusion of membranous organelles. Hemizygous worms [spe-46(hc197)/mnDf111] are effectively sterile. Thus, spe-46 appears to be involved in the regulation of spermatid activation during spermiogenesis, with the null phenotype being an absence of functional sperm and hypomorphic phenotypes being premature spermatid activation and numerous

  2. Activation of SIRT3 by the NAD⁺ precursor nicotinamide riboside protects from noise-induced hearing loss.

    PubMed

    Brown, Kevin D; Maqsood, Sadia; Huang, Jing-Yi; Pan, Yong; Harkcom, William; Li, Wei; Sauve, Anthony; Verdin, Eric; Jaffrey, Samie R

    2014-12-02

    Intense noise exposure causes hearing loss by inducing degeneration of spiral ganglia neurites that innervate cochlear hair cells. Nicotinamide adenine dinucleotide (NAD(+)) exhibits axon-protective effects in cultured neurons; however, its ability to block degeneration in vivo has been difficult to establish due to its poor cell permeability and serum instability. Here, we describe a strategy to increase cochlear NAD(+) levels in mice by administering nicotinamide riboside (NR), a recently described NAD(+) precursor. We find that administration of NR, even after noise exposure, prevents noise-induced hearing loss (NIHL) and spiral ganglia neurite degeneration. These effects are mediated by the NAD(+)-dependent mitochondrial sirtuin, SIRT3, since SIRT3-overexpressing mice are resistant to NIHL and SIRT3 deletion abrogates the protective effects of NR and expression of NAD(+) biosynthetic enzymes. These findings reveal that administration of NR activates a NAD(+)-SIRT3 pathway that reduces neurite degeneration caused by noise exposure.

  3. Conformational change results in loss of enzymatic activity of jack bean urease on its interaction with silver nanoparticle.

    PubMed

    Ponnuvel, Shobana; Subramanian, Balakumar; Ponnuraj, Karthe

    2015-10-01

    Urease is an enzyme produced by microbes such as bacteria, yeast and fungi. Plants also produce this enzyme. Urease action splits urea into ammonia and carbamate. This action is having important implications in agro-chemical, medicinal and environment. Therefore there is always a constant search for new and novel compounds which could inhibit this enzyme. Here we have studied the interaction of jack bean urease (JBU) with silver nanoparticle to analyze the influence of the resultant protein corona formation on the catalytic property of JBU. Several techniques like UV-Vis, gel shift assay and CD spectroscopy have been used to characterize this interaction. Urease activity assay suggests that the protein corona formation inhibits the enzymatic action of JBU. The loss of enzymatic action could be either due to the nanoparticle blocking the active site of JBU or a conformational change in the protein. The CD spectra of JBU-AgNP complexes clearly revealed significant changes in the secondary structural composition of the JBU and this could be the reason for the loss of enzymatic activity of JBU. This study revealed an interesting observation, where the interaction of AgNP with JBU resulted destabilization of hexameric nature of JBU which is otherwise highly stable. The results of the present study could be useful in the development of nanoparticle based material for inhibiting the ureolytic activity of ureases in different fields.

  4. Mobile Phone Apps to Promote Weight Loss and Increase Physical Activity: A Systematic Review and Meta-Analysis

    PubMed Central

    Ferré-Grau, Carme; Montaña-Carreras, Xavier

    2015-01-01

    Background To our knowledge, no meta-analysis to date has assessed the efficacy of mobile phone apps to promote weight loss and increase physical activity. Objective To perform a systematic review and meta-analysis of studies to compare the efficacy of mobile phone apps compared with other approaches to promote weight loss and increase physical activity. Methods We conducted a systematic review and meta-analysis of relevant studies identified by a search of PubMed, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Scopus from their inception through to August 2015. Two members of the study team (EG-F, GF-M) independently screened studies for inclusion criteria and extracted data. We included all controlled studies that assessed a mobile phone app intervention with weight-related health measures (ie, body weight, body mass index, or waist circumference) or physical activity outcomes. Net change estimates comparing the intervention group with the control group were pooled across studies using random-effects models. Results We included 12 articles in this systematic review and meta-analysis. Compared with the control group, use of a mobile phone app was associated with significant changes in body weight (kg) and body mass index (kg/m2) of -1.04 kg (95% CI -1.75 to -0.34; I2 = 41%) and -0.43 kg/m2 (95% CI -0.74 to -0.13; I2 = 50%), respectively. Moreover, a nonsignificant difference in physical activity was observed between the two groups (standardized mean difference 0.40, 95% CI -0.07 to 0.87; I2 = 93%). These findings were remarkably robust in the sensitivity analysis. No publication bias was shown. Conclusions Evidence from this study shows that mobile phone app-based interventions may be useful tools for weight loss. PMID:26554314

  5. Host density and human activities mediate increased parasite prevalence and richness in primates threatened by habitat loss and fragmentation.

    PubMed

    Mbora, David N M; McPeek, Mark A

    2009-01-01

    1. Habitat loss and fragmentation are the principal causes of the loss of biological diversity. In addition, parasitic diseases are an emerging threat to many animals. Nevertheless, relatively few studies have tested how habitat loss and fragmentation influence the prevalence and richness of parasites in animals. 2. Several studies of nonhuman primates have shown that measures of human activity and forest fragmentation correlate with parasitism in primates. However, these studies have not tested for the ecological mechanism(s) by which human activities or forest fragmentation influence the prevalence and richness of parasites. 3. We tested the hypothesis that increased host density due to forest fragmentation and loss mediates increases in the prevalence and richness of gastrointestinal parasites in two forest primates, the Tana River red colobus (Procolobus rufomitratus, Peters 1879) and mangabey (Cercocebus galeritus galeritus, Peters 1879). We focused on population density because epidemiological theory states that host density is a key determinant of the prevalence and richness of directly transmitted parasites in animals. 4. The Tana River red colobus and mangabey are endemic to a highly fragmented forest ecosystem in eastern Kenya where habitat changes are caused by a growing human population increasingly dependent on forest resources and on clearing forest for cultivation. 5. We found that the prevalence of parasites in the two monkeys was very high compared to primates elsewhere. Density of monkeys was positively associated with forest area and disturbance in forests. In turn, the prevalence and richness of parasites was significantly associated with monkey density, and attributes indicative of human disturbance in forests. 6. We also found significant differences in the patterns of parasitism between the colobus and the mangabey possibly attributable to differences in their behavioural ecology. Colobus are arboreal folivores while mangabeys are terrestrial

  6. 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.

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

    NASA Astrophysics Data System (ADS)

    Halladay, R. H.; Terrill, S. D.; Bowling, D. R.; Gagnon, D. R.

    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.

  8. Depletion of pituitary prolactin by cysteamine is due to loss of immunological activity.

    PubMed

    Scammell, J G; Dannies, P S

    1984-03-01

    The mechanism by which cysteamine reduces the PRL content of pituitary cells was studied in primary cultures of estradiol-induced pituitary tumors in Fischer 344 rats. The PRL content of these cells was effectively decreased by cysteamine, with an IC50 of 0.2 mM. Cells previously labeled with [3H]leucine were exposed to cysteamine (0.25 mM), and the intracellular content of [3H]PRL was measured by immunological or nonimmunological means, that is by immunoprecipitation and electrophoresis or by electrophoresis alone. The intracellular concentration of immunoreactive [3H]PRL was reduced by 53% by cysteamine, whereas [3H]PRL quantified by electrophoresis alone was not significantly affected. Our data indicate that cysteamine reduces the PRL content of pituitary tumor cells by causing the loss of its immunoreactivity.

  9. Depletion of pituitary prolactin by cysteamine is due to loss of immunological activity

    SciTech Connect

    Scammell, J.G.; Dannies, P.S.

    1984-03-01

    The mechanism by which cysteamine reduces the prolactin(PRL) content of pituitary cells was studied in primary cultures of estradiol-induced pituitary tumors in Fischer 344 rats. The PRL content of these cells was effectively decreased by cysteamine, with an IC50 of 0.2 mM. Cells previously labeled with (/sup 3/H)leucine were exposed to cysteamine (0.25 mM), and the intracellular content of (/sup 3/H)PRL was measured by immunological or nonimmunological means, that is by immunoprecipitation and electrophoresis or by electrophoresis alone. The intracellular concentration of immunoreactive (/sup 3/H)PRL was reduced by 53% by cysteamine, whereas (/sup 3/H)PRL quantified by electrophoresis alone was not significantly affected. Our data indicate that cysteamine reduces the PRL content of pituitary tumor cells by causing the loss of its immunoreactivity.

  10. Loss of tumor suppressor Merlin results in aberrant activation of Wnt/β-catenin signaling in cancer

    PubMed Central

    Meng, Erhong; Menezes, Mitchell E.; Bailey, Sarah K.; Metge, Brandon J.; Buchsbaum, Donald J.; Samant, Rajeev S.; Shevde, Lalita A.

    2016-01-01

    The expression of the tumor suppressor Merlin is compromised in nervous system malignancies due to genomic aberrations. We demonstrated for the first time, that in breast cancer, Merlin protein expression is lost due to proteasome-mediated elimination. Immunohistochemical analysis of tumor tissues from patients with metastatic breast cancer revealed characteristically reduced Merlin expression. Importantly, we identified a functional role for Merlin in impeding breast tumor xenograft growth and reducing invasive characteristics. We sought to determine a possible mechanism by which Merlin accomplishes this reduction in malignant activity. We observed that breast and pancreatic cancer cells with loss of Merlin show an aberrant increase in the activity of β-catenin concomitant with nuclear localization of β-catenin. We discovered that Merlin physically interacts with β-catenin, alters the sub-cellular localization of β-catenin, and significantly reduces the protein levels of β-catenin by targeting it for degradation through the upregulation of Axin1. Consequently, restoration of Merlin inhibited β-catenin-mediated transcriptional activity in breast and pancreatic cancer cells. We also present evidence that loss of Merlin sensitizes tumor cells to inhibition by compounds that target β-catenin-mediated activity. Thus, this study provides compelling evidence that Merlin reduces the malignant activity of pancreatic and breast cancer, in part by suppressing the Wnt/β-catenin pathway. Given the potent role of Wnt/β-catenin signaling in breast and pancreatic cancer and the flurry of activity to test β-catenin inhibitors in the clinic, our findings are opportune and provide evidence for Merlin in restraining aberrant activation of Wnt/β-catenin signaling. PMID:26908451

  11. Active cooling of pulse compression diffraction gratings for high energy, high average power ultrafast lasers.

    PubMed

    Alessi, David A; Rosso, Paul A; Nguyen, Hoang T; Aasen, Michael D; Britten, Jerald A; Haefner, Constantin

    2016-12-26

    Laser energy absorption and subsequent heat removal from diffraction gratings in chirped pulse compressors poses a significant challenge in high repetition rate, high peak power laser development. In order to understand the average power limitations, we have modeled the time-resolved thermo-mechanical properties of current and advanced diffraction gratings. We have also developed and demonstrated a technique of actively cooling Petawatt scale, gold compressor gratings to operate at 600W of average power - a 15x increase over the highest average power petawatt laser currently in operation. Combining this technique with low absorption multilayer dielectric gratings developed in our group would enable pulse compressors for petawatt peak power lasers operating at average powers well above 40kW.

  12. A six-junction GaAs laser power converter with different sizes of active aperture

    NASA Astrophysics Data System (ADS)

    Sun, Yu-run; Dong, Jian-rong; He, Yang; Zhao, Yong-ming; Yu, Shu-zhen; Xue, Ji-ping; Xue, Chi; Wang, Jin; Lu, Yun-qing; Ding, Yan-wen

    2017-01-01

    We investigate a novel GaAs-based laser power converters (LPCs) grown by metal-organic chemical vapor deposition (MOCVD), which uses a single monolithic structure with six junctions connected by tunnel junctions to obtain a high output voltage. The LPCs with diameters of active aperture of 2 mm and 4 mm were fabricated and tested. The test results show that under an 808 nm laser, two LPCs both show an open circuit voltage of above 6.5 V. A maximum power conversion efficiency of 50.2% is obtained by 2 mm sample with laser power of 0.256 W, and an output electric power of 1.9 W with laser power of 4.85 W is obtained by 4 mm sample. The performances of the LPCs are deteriorated under illumination of high flux, and the 4 mm sample shows a higher laser power tolerance.

  13. The effect of the magnetic nanoparticle's size dependence of the relaxation time constant on the specific loss power of magnetic nanoparticle hyperthermia

    NASA Astrophysics Data System (ADS)

    Harabech, Mariem; Leliaert, Jonathan; Coene, Annelies; Crevecoeur, Guillaume; Van Roost, Dirk; Dupré, Luc

    2017-03-01

    Magnetic nanoparticle hyperthermia is a cancer treatment in which magnetic nanoparticles (MNPs) are subjected to an alternating magnetic field to induce heat in the tumor. The generated heat of MNPs is characterized by the specific loss power (SLP) due to relaxation phenomena of the MNP. Up to now, several models have been proposed to predict the SLP, one of which is the Linear Response Theory. One parameter in this model is the relaxation time constant. In this contribution, we employ a macrospin model based on the Landau-Lifshitz-Gilbert equation to investigate the relation between the Gilbert damping parameter and the relaxation time constant. This relaxation time has a pre-factor τ0 which is often taken as a fixed value ranging between 10-8 and 10-12 s. However, in reality it has small size dependence. Here, the influence of this size dependence on the calculation of the SLP is demonstrated, consequently improving the accuracy of this estimate.

  14. Permeability of enamel following light-activated power bleaching.

    PubMed

    Turssi, Cecilia P; Schiavoni, Renato J; Serra, Monica C; Froner, Izabel C

    2006-01-01

    This study sought to ascertain whether in-office photocured bleaching techniques would increase permeability to enamel. A 7.1 mm2 circular area located in the middle third of the coronal portion of 90 human canines was isolated by applying an acid-resistant varnish to the remaining surfaces of the tooth. According to a randomized complete block design (n = 15), specimens were treated using a 35% hydrogen peroxide bleaching product activated by an integrated LED/diode laser (LED/laser) source or a quartz tungsten halogen (QTH) light. Bleaching was accomplished by applying the 35% hydrogen peroxide agent to the enamel surface in three 10-minute sessions, conducted at one-week intervals over a period of three weeks. For the photocured bleached groups, a bleaching agent was applied to the specimen and irradiated with the LED/laser device or the QTH light for 30 seconds. Negative control groups were exposed to artificial saliva or irradiated by the LED/laser device or the QTH light. Specimens were subjected to a histochemical coloring method that employed copper sulfate and dithio-oxamide solutions. Three 300-microm thick sections taken from the exposed area were imaged in an optical microscope. Permeability was measured in the digitized images as the percentage of copper ions penetration over the total enamel thickness. Friedman's test (alpha = 0.05) showed significant difference among groups. Least significant difference test revealed that in comparison with the group treated with 35% hydrogen peroxide only, there was no significant increase in enamel permeability when bleaching was activated by either the LED/laser or QTH light devices but all bleached groups showed higher permeability than the unbleached/nonirradiated group.

  15. Analysis of loss-of-coolant accident for a fast-spectrum lithium-cooled nuclear reactor for space-power applications

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Petrik, E. J.; Kieffer, A. W.

    1972-01-01

    A two-dimensional, transient, heat-transfer analysis was made to determine the temperature response in the core of a conceptual space-power nuclear reactor following a total loss of reactor coolant. With loss of coolant from the reactor, the controlling mode of heat transfer is thermal radiation. In one of the schemes considered for removing decay heat from the core, it was assumed that the 4 pi shield which surrounds the core acts as a constant-temperature sink (temperature, 700 K) for absorption of thermal radiation from the core. Results based on this scheme of heat removal show that melting of fuel in the core is possible only when the emissivity of the heat-radiating surfaces in the core is less than about 0.40. In another scheme for removing the afterheat, the core centerline fuel pin was replaced by a redundant, constant temperature, coolant channel. Based on an emissivity of 0.20 for all material surfaces in the core, the calculated maximum fuel temperature for this scheme of heat removal was 2840 K, or about 90 K less than the melting temperature of the UN fuel.

  16. Mitogen-Activated Protein Kinase 2 Signaling Shapes Macrophage Plasticity in Aggregatibacter actinomycetemcomitans-Induced Bone Loss.

    PubMed

    Herbert, Bethany A; Steinkamp, Heidi M; Gaestel, Matthias; Kirkwood, Keith L

    2017-01-01

    Aggregatibacter actinomycetemcomitans is associated with aggressive periodontal disease, which is characterized by inflammation-driven alveolar bone loss. A. actinomycetemcomitans activates the p38 mitogen-activated protein kinase (MAPK) and MAPK-activated protein kinase 2 (MK2) stress pathways in macrophages that are involved in host responses. During the inflammatory process in periodontal disease, chemokines are upregulated to promote recruitment of inflammatory cells. The objective of this study was to determine the role of MK2 signaling in chemokine regulation during A. actinomycetemcomitans pathogenesis. Utilizing a murine calvarial model, Mk2(+/+) and Mk2(-/-) mice were treated with live A. actinomycetemcomitans bacteria at the midsagittal suture. MK2 positively regulated the following macrophage RNA: Emr1 (F4/80), Itgam (CD11b), Csf1r (M-CSF Receptor), Itgal (CD11a), Tnf, and Nos2 Additionally, RNA analysis revealed that MK2 signaling regulated chemokines CCL3 and CCL4 in murine calvarial tissue. Utilizing the chimeric murine air pouch model, MK2 signaling differentially regulated CCL3 and CCL4 in the hematopoietic and nonhematopoietic compartments. Bone resorption pits in calvaria, observed by micro-computed tomography, and osteoclast formation were decreased in Mk2(-/-) mice compared to Mk2(+/+) mice after A. actinomycetemcomitans treatment. In conclusion, these data suggest that MK2 in macrophages contributes to regulation of chemokine signaling during A. actinomycetemcomitans-induced inflammation and bone loss.

  17. Loss of Frataxin induces iron toxicity, sphingolipid synthesis, and Pdk1/Mef2 activation, leading to neurodegeneration

    PubMed Central

    Chen, Kuchuan; Lin, Guang; Haelterman, Nele A; Ho, Tammy Szu-Yu; Li, Tongchao; Li, Zhihong; Duraine, Lita; Graham, Brett H; Jaiswal, Manish; Yamamoto, Shinya; Rasband, Matthew N; Bellen, Hugo J

    2016-01-01

    Mutations in Frataxin (FXN) cause Friedreich’s ataxia (FRDA), a recessive neurodegenerative disorder. Previous studies have proposed that loss of FXN causes mitochondrial dysfunction, which triggers elevated reactive oxygen species (ROS) and leads to the demise of neurons. Here we describe a ROS independent mechanism that contributes to neurodegeneration in fly FXN mutants. We show that loss of frataxin homolog (fh) in Drosophila leads to iron toxicity, which in turn induces sphingolipid synthesis and ectopically activates 3-phosphoinositide dependent protein kinase-1 (Pdk1) and myocyte enhancer factor-2 (Mef2). Dampening iron toxicity, inhibiting sphingolipid synthesis by Myriocin, or reducing Pdk1 or Mef2 levels, all effectively suppress neurodegeneration in fh mutants. Moreover, increasing dihydrosphingosine activates Mef2 activity through PDK1 in mammalian neuronal cell line suggesting that the mechanisms are evolutionarily conserved. Our results indicate that an iron/sphingolipid/Pdk1/Mef2 pathway may play a role in FRDA. DOI: http://dx.doi.org/10.7554/eLife.16043.001 PMID:27343351

  18. Loss of H2 histamine receptor activity in rabbit aorta after maturity

    SciTech Connect

    Holl, J.E.; Mokler, C.M.

    1982-01-01

    The activity of H1 and H2 histaminergic receptors was studied in aortic strips taken from young (6 weeks) and mature (7-8 months) rabbits. H1-mediated contractile activity was similar in both age groups, but H2 receptor relaxant activity was greatly diminished in mature rabbits. H2 receptor activity was evaluated with two experimental approaches: its modifying effect on blockade of H1 receptors by diphenhydramine (DPN), and its capacity to directly relax precontracted strips. Schild plot evaluation of DPN blockade revealed that the slope of the plot was below 1.0 in strips from young rabbits (0.77), but not in strips from mature rabbits (0.94). Propranolol pretreatment did not increase the Schild plot slope (0.66) of young aortic strips, but metiamide pretreatment did (0.92). Metiamide treatment did not further in crease slope of mature strips (0.95). When the slopes of the plots were near 1.0, as in the mature and metiamide-treated mature and young strips, the pA2 of DPN was very close (7.51, 7.70, and 7.65). Lost H2 receptor activity in maturity was confirmed by relaxing norepinephrine-precontracted strips with histamine or dimaprit. Histamine-induced relaxation of precontracted strips was slightly diminished in mature strips, while the relaxing activity of dimaprit was greatly reduced in mature tissue. The same strips relaxed vigorously when exposed to nitroglycerin or NaNO2, demonstrating that the strips were capable of relaxing. Therefore, it appears that H2 receptor activity in rabbit aorta is greatly diminished as the animal matures.

  19. High fat diet-induced changes of mouse hepatic transcription and enhancer activity can be reversed by subsequent weight loss.

    PubMed

    Siersbæk, Majken; Varticovski, Lyuba; Yang, Shutong; Baek, Songjoon; Nielsen, Ronni; Mandrup, Susanne; Hager, Gordon L; Chung, Jay H; Grøntved, Lars

    2017-01-10

    Epigenetic factors have been suggested to play an important role in metabolic memory by trapping and maintaining initial metabolic changes within the transcriptional regulatory machinery. In this study we fed mice a high fat diet (HFD) for seven weeks followed by additional five weeks of chow, to identify HFD-mediated changes to the hepatic transcriptional program that may persist after weight loss. Mice fed a HFD displayed increased fasting insulin levels, hepatosteatosis and major changes in hepatic gene transcription associated with modulation of H3K27Ac at enhancers, but no significant changes in chromatin accessibility, indicating that HFD-regulated gene transcription is primarily controlled by modulating the activity of pre-established enhancers. After return to the same body weight as chow fed control mice, the fasting insulin, glucose, and hepatic triglyceride levels were fully restored to normal levels. Moreover, HFD-regulated H3K27Ac and mRNA levels returned to similar levels as control mice. These data demonstrates that the transcription regulatory landscape in the liver induced by HFD is highly dynamic and can be reversed by weight loss. This provides hope for efficient treatment of early obesity-associated changes to hepatic complications by simple weight loss intervention without persistent reprograming of the liver transcriptome.

  20. High fat diet-induced changes of mouse hepatic transcription and enhancer activity can be reversed by subsequent weight loss

    PubMed Central

    Siersbæk, Majken; Varticovski, Lyuba; Yang, Shutong; Baek, Songjoon; Nielsen, Ronni; Mandrup, Susanne; Hager, Gordon L.; Chung, Jay H.; Grøntved, Lars

    2017-01-01

    Epigenetic factors have been suggested to play an important role in metabolic memory by trapping and maintaining initial metabolic changes within the transcriptional regulatory machinery. In this study we fed mice a high fat diet (HFD) for seven weeks followed by additional five weeks of chow, to identify HFD-mediated changes to the hepatic transcriptional program that may persist after weight loss. Mice fed a HFD displayed increased fasting insulin levels, hepatosteatosis and major changes in hepatic gene transcription associated with modulation of H3K27Ac at enhancers, but no significant changes in chromatin accessibility, indicating that HFD-regulated gene transcription is primarily controlled by modulating the activity of pre-established enhancers. After return to the same body weight as chow fed control mice, the fasting insulin, glucose, and hepatic triglyceride levels were fully restored to normal levels. Moreover, HFD-regulated H3K27Ac and mRNA levels returned to similar levels as control mice. These data demonstrates that the transcription regulatory landscape in the liver induced by HFD is highly dynamic and can be reversed by weight loss. This provides hope for efficient treatment of early obesity-associated changes to hepatic complications by simple weight loss intervention without persistent reprograming of the liver transcriptome. PMID:28071704

  1. Loss of both phospholipid and triglyceride transfer activities of microsomal triglyceride transfer protein in abetalipoproteinemia.

    PubMed

    Khatun, Irani; Walsh, Meghan T; Hussain, M Mahmood

    2013-06-01

    Mutations in microsomal triglyceride transfer protein (MTP) cause abetalipoproteinemia (ABL), characterized by the absence of plasma apoB-containing lipoproteins. In this study, we characterized the effects of various MTP missense mutations found in ABL patients with respect to their expression, subcellular location, and interaction with protein disulfide isomerase (PDI). In addition, we characterized functional properties by analyzing phospholipid and triglyceride transfer activities and studied their ability to support apoB secretion. All the mutants colocalized with calnexin and interacted with PDI. We found that R540H and N780Y, known to be deficient in triglyceride transfer activity, also lacked phospholipid transfer activity. Novel mutants S590I and G746E did not transfer triglycerides and phospholipids and did not assist in apoB secretion. In contrast, D384A displayed both triglyceride and phospholipid transfer activities and supported apoB secretion. These studies point out that ABL is associated with the absence of both triglyceride and phospholipid transfer activities in MTP.

  2. A Curriculum Activities Guide to Electric Power Generation and the Environment.

    ERIC Educational Resources Information Center

    Tully, Randolph R., Jr., Ed.

    This guide was developed by teachers involved in a workshop on "Electric Power Generation and the Environment." Activity topics are: (1) Energy and the Consumer; (2) Energy and Water Pollution; and (3) Energy and Air Pollution. Within these topics, the activities are classified as awareness level, transitional level, or operational…

  3. The effects of bicycle frame geometry on muscle activation and power during a wingate anaerobic test.

    PubMed

    Ricard, Mark D; Hills-Meyer, Patrick; Miller, Michael G; Michael, Timothy J

    2006-01-01

    The purpose of this study was to compare the effects of bicycle seat tube angles (STA) of (72° and 82°) on power production and EMG of the vastus laeralis (VL), vastus medialis (VM), semimembranous (SM), biceps femoris (BF) during a Wingate test (WAT). Twelve experienced cyclists performed a WAT at each STA. Repeated measures ANOVA was used to identify differences in muscular activation by STA. EMG variables were normalized to isometric maximum voluntary contraction (MVC). Paired t-tests were used to test the effects of STA on: peak power, average power, minimum power and percent power drop. Results indicated BF activation was significantly lower at STA 82° (482.9 ± 166.6 %MVC·s) compared to STA 72° (712.6 ± 265.6 %MVC·s). There were no differences in the power variables between STAs. The primary finding was that increasing the STA from 72° to 82° enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle. Key PointsRoad cyclists claim that bicycle seat tube angles between 72° and 76° are most effective for optimal performance in racing.Triathletes typically use seat tube angles greater than 76°. It is thought that a seat tube angle greater than 76° facilitates a smoother bike to run transition in the triathlon.Increasing the seat tube angle from 72 to 82 enabled triathletes' to maintain power production, while significantly reducing the muscular activation of the biceps femoris muscle.Reduced hamstring muscular activation in the triathlon frame (82 seat tube angle) may serve to reduce hamstring tightness following the bike phase of the triathlon, allowing the runner to use a longer stride length.

  4. Evaluating the Workload of On-Call Psychiatry Residents: Which Activities Are Associated with Sleep Loss?

    ERIC Educational Resources Information Center

    Cooke, Brian K.; Cooke, Erinn O.; Sharfstein, Steven S.

    2012-01-01

    Objective: The purpose of this study was to review the workload inventory of on-call psychiatry residents and to evaluate which activities were associated with reductions in on-call sleep. Method: A prospective cohort study was conducted, following 20 psychiatry residents at a 231-bed psychiatry hospital, from July 1, 2008 through June 30, 2009.…

  5. Cerebellar Ataxia and Coenzyme Q Deficiency through Loss of Unorthodox Kinase Activity.

    PubMed

    Stefely, Jonathan A; Licitra, Floriana; Laredj, Leila; Reidenbach, Andrew G; Kemmerer, Zachary A; Grangeray, Anais; Jaeg-Ehret, Tiphaine; Minogue, Catherine E; Ulbrich, Arne; Hutchins, Paul D; Wilkerson, Emily M; Ruan, Zheng; Aydin, Deniz; Hebert, Alexander S; Guo, Xiao; Freiberger, Elyse C; Reutenauer, Laurence; Jochem, Adam; Chergova, Maya; Johnson, Isabel E; Lohman, Danielle C; Rush, Matthew J P; Kwiecien, Nicholas W; Singh, Pankaj K; Schlagowski, Anna I; Floyd, Brendan J; Forsman, Ulrika; Sindelar, Pavel J; Westphall, Michael S; Pierrel, Fabien; Zoll, Joffrey; Dal Peraro, Matteo; Kannan, Natarajan; Bingman, Craig A; Coon, Joshua J; Isope, Philippe; Puccio, Hélène; Pagliarini, David J

    2016-08-18

    The UbiB protein kinase-like (PKL) family is widespread, comprising one-quarter of microbial PKLs and five human homologs, yet its biochemical activities remain obscure. COQ8A (ADCK3) is a mammalian UbiB protein associated with ubiquinone (CoQ) biosynthesis and an ataxia (ARCA2) through unclear means. We show that mice lacking COQ8A develop a slowly progressive cerebellar ataxia linked to Purkinje cell dysfunction and mild exercise intolerance, recapitulating ARCA2. Interspecies biochemical analyses show that COQ8A and yeast Coq8p specifically stabilize a CoQ biosynthesis complex through unorthodox PKL functions. Although COQ8 was predicted to be a protein kinase, we demonstrate that it lacks canonical protein kinase activity in trans. Instead, COQ8 has ATPase activity and interacts with lipid CoQ intermediates, functions that are likely conserved across all domains of life. Collectively, our results lend insight into the molecular activities of the ancient UbiB family and elucidate the biochemical underpinnings of a human disease.

  6. 26 CFR 1.469-2T - Passive activity loss (temporary).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... taxable year exceed the passive activity gross income for the taxable year. (2) Cross references. See... or business of performing such services or selling such property, but only if credit is customarily... such entity. (4) Cross reference. For special rules applicable to certain gross income from a trade...

  7. 26 CFR 1.469-2T - Passive activity loss (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... taxable year exceed the passive activity gross income for the taxable year. (2) Cross references. See... or business of performing such services or selling such property, but only if credit is customarily... such entity. (4) Cross reference. For special rules applicable to certain gross income from a trade...

  8. Recent drilling activities at the earth power resources Tuscarora geothermal power project's hot sulphur springs lease area.

    SciTech Connect

    Goranson, Colin

    2005-03-01

    Earth Power Resources, Inc. recently completed a combined rotary/core hole to a depth of 3,813 feet at it's Hot Sulphur Springs Tuscarora Geothermal Power Project Lease Area located 70-miles north of Elko, Nevada. Previous geothermal exploration data were combined with geologic mapping and newly acquired seismic-reflection data to identify a northerly tending horst-graben structure approximately 2,000 feet wide by at least 6,000 feet long with up to 1,700 feet of vertical offset. The well (HSS-2) was successfully drilled through a shallow thick sequence of altered Tertiary Volcanic where previous exploration wells had severe hole-caving problems. The ''tight-hole'' drilling problems were reduced using drilling fluids consisting of Polymer-based mud mixed with 2% Potassium Chloride (KCl) to reduce Smectite-type clay swelling problems. Core from the 330 F fractured geothermal reservoir system at depths of 2,950 feet indicated 30% Smectite type clays existed in a fault-gouge zone where total loss of circulation occurred during coring. Smectite-type clays are not typically expected at temperatures above 300 F. The fracture zone at 2,950 feet exhibited a skin-damage during injection testing suggesting that the drilling fluids may have caused clay swelling and subsequent geothermal reservoir formation damage. The recent well drilling experiences indicate that drilling problems in the shallow clays at Hot Sulphur Springs can be reduced. In addition, average penetration rates through the caprock system can be on the order of 25 to 35 feet per hour. This information has greatly reduced the original estimated well costs that were based on previous exploration drilling efforts. Successful production formation drilling will depend on finding drilling fluids that will not cause formation damage in the Smectite-rich fractured geothermal reservoir system. Information obtained at Hot Sulphur Springs may apply to other geothermal systems developed in volcanic settings.

  9. 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.

  10. 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.

  11. 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.

  12. Design and real time implementation of fuzzy switched controller for single phase active power filter.

    PubMed

    Afghoul, Hamza; Krim, Fateh; Chikouche, Djamel; Beddar, Antar

    2015-09-01

    This paper proposes a novel fuzzy switched controller (FSC) integrated in direct current control (DCC) algorithm for single phase active power filter (SPAPF). The controller under study consists of conventional PI controller, fractional order PI controller (FO-PI) and fuzzy decision maker (FDM) that switches between them using reduced fuzzy logic control. The proposed controller offers short response time with low damping and deals efficiently with the external disturbances while preserving the robustness properties. To fulfill the requirements of power quality, unity power factor and harmonics limitations in active power filtering an experimental test bench has been built using dSPACE 1104 to demonstrate the feasibility and effectiveness of the proposed controller. The obtained results present high performance in steady and transient states.

  13. Loss of Function of TET2 Cooperates with Constitutively Active KIT in Murine and Human Models of Mastocytosis

    PubMed Central

    De Vita, Serena; Schneider, Rebekka K.; Garcia, Michael; Wood, Jenna; Gavillet, Mathilde; Ebert, Benjamin L.; Gerbaulet, Alexander; Roers, Axel; Levine, Ross L.; Mullally, Ann; Williams, David A.

    2014-01-01

    Systemic Mastocytosis (SM) is a clonal disease characterized by abnormal accumulation of mast cells in multiple organs. Clinical presentations of the disease vary widely from indolent to aggressive forms, and to the exceedingly rare mast cell leukemia. Current treatment of aggressive SM and mast cell leukemia is unsatisfactory. An imatinib-resistant activating mutation of the receptor tyrosine kinase KIT (KIT D816V) is most frequently present in transformed mast cells and is associated with all clinical forms of the disease. Thus the etiology of the variable clinical aggressiveness of abnormal mast cells in SM is unclear. TET2 appears to be mutated in primary human samples in aggressive types of SM, suggesting a possible role in disease modification. In this report, we demonstrate the cooperation between KIT D816V and loss of function of TET2 in mast cell transformation and demonstrate a more aggressive phenotype in a murine model of SM when both mutations are present in progenitor cells. We exploit these findings to validate a combination treatment strategy targeting the epigenetic deregulation caused by loss of TET2 and the constitutively active KIT receptor for the treatment of patients with aggressive SM. PMID:24788138

  14. Loss of the polycomb mark from bivalent promoters leads to activation of cancer-promoting genes in colorectal tumors.

    PubMed

    Hahn, Maria A; Li, Arthur X; Wu, Xiwei; Yang, Richard; Drew, David A; Rosenberg, Daniel W; Pfeifer, Gerd P

    2014-07-01

    In colon tumors, the transcription of many genes becomes deregulated by poorly defined epigenetic mechanisms that have been studied mainly in established cell lines. In this study, we used frozen human colon tissues to analyze patterns of histone modification and DNA cytosine methylation in cancer and matched normal mucosa specimens. DNA methylation is strongly targeted to bivalent H3K4me3- and H3K27me3-associated promoters, which lose both histone marks and acquire DNA methylation. However, we found that loss of the Polycomb mark H3K27me3 from bivalent promoters was accompanied often by activation of genes associated with cancer progression, including numerous stem cell regulators, oncogenes, and proliferation-associated genes. Indeed, we found many of these same genes were also activated in patients with ulcerative colitis where chronic inflammation predisposes them to colon cancer. Based on our findings, we propose that a loss of Polycomb repression at bivalent genes combined with an ensuing selection for tumor-driving events plays a major role in cancer progression.

  15. 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)

  16. Associations between platelet monoamine oxidase-B activity and acquired colour vision loss in a fish-eating population.

    PubMed

    Stamler, Christopher John; Mergler, Donna; Abdelouahab, Nadia; Vanier, Claire; Chan, Hing Man

    2006-01-01

    Platelet monoamine oxidase-B (MAO-B) has been considered a surrogate biochemical marker of neurotoxicity, as it may reflect changes in the monoaminergic system in the brain. Colour vision discrimination, in part a dopamine dependent process, has been used to identify early neurological effects of some environmental and industrial neurotoxicants. The objective of this cross-sectional study was to explore the relationship between platelet MAO-B activity and acquired colour discrimination capacity in fish-consumers from the St. Lawrence River region of Canada. Assessment of acquired dyschromatopsia was determined using the Lanthony D-15 desaturated panel test. Participants classified with dyschromatopsia (n=81) had significantly lower MAO-B activity when compared to those with normal colour vision (n=32) (26.5+/-9.6 versus 31.0+/-9.9 nmol/min/20 microg, P=0.030)). Similarly, Bowman's Colour Confusion Index (CCI) was inversely correlated with MAO-B activity when the vision test was performed with the worst eye only (r=-0.245, P=0.009), the best eye only (r=-0.188, P=0.048) and with both eyes together (r=-0.309, P=0.001). Associations remained significant after adjustment for age and gender when both eyes (P=0.003) and the worst eye (P=0.045) were tested. Adjustment for heavy smoking weakened the association between MAO-B and CCI in the worst eye (P=0.140), but did not alter this association for both eyes (P=0.006). Adjustment for blood-mercury concentrations did not change the association. This study suggests a relationship between reduced MAO-B activity and acquired colour vision loss and both are associated with tobacco smoking. Therefore, results show that platelet MAO-B may be used as a surrogate biochemical marker of acquired colour vision loss.

  17. 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.

  18. 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.

  19. 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.

  20. Chronic AMPK activation via loss of FLCN induces functional beige adipose tissue through PGC-1α/ERRα

    PubMed Central

    Yan, Ming; Audet-Walsh, Étienne; Manteghi, Sanaz; Rosa Dufour, Catherine; Walker, Benjamin; Baba, Masaya; St-Pierre, Julie; Giguère, Vincent; Pause, Arnim

    2016-01-01

    The tumor suppressor folliculin (FLCN) forms a repressor complex with AMP-activated protein kinase (AMPK). Given that AMPK is a master regulator of cellular energy homeostasis, we generated an adipose-specific Flcn (Adipoq-FLCN) knockout mouse model to investigate the role of FLCN in energy metabolism. We show that loss of FLCN results in a complete metabolic reprogramming of adipose tissues, resulting in enhanced oxidative metabolism. Adipoq-FLCN knockout mice exhibit increased energy expenditure and are protected from high-fat diet (HFD)-induced obesity. Importantly, FLCN ablation leads to chronic hyperactivation of AMPK, which in turns induces and activates two key transcriptional regulators of cellular metabolism, proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) and estrogen-related receptor α (ERRα). Together, the AMPK/PGC-1α/ERRα molecular axis positively modulates the expression of metabolic genes to promote mitochondrial biogenesis and activity. In addition, mitochondrial uncoupling proteins as well as other markers of brown fat are up-regulated in both white and brown FLCN-null adipose tissues, underlying the increased resistance of Adipoq-FLCN knockout mice to cold exposure. These findings identify a key role of FLCN as a negative regulator of mitochondrial function and identify a novel molecular pathway involved in the browning of white adipocytes and the activity of brown fat. PMID:27151976

  1. Longitudinal study of striatal activation to reward and loss anticipation from mid-adolescence into late adolescence/early adulthood.

    PubMed

    Lamm, C; Benson, B E; Guyer, A E; Perez-Edgar, K; Fox, N A; Pine, D S; Ernst, M

    2014-08-01

    Adolescent risk-taking behavior has been associated with age-related changes in striatal activation to incentives. Previous cross-sectional studies have shown both increased and decreased striatal activation to incentives for adolescents compared to adults. The monetary incentive delay (MID) task, designed to assess functional brain activation in anticipation of reward, has been used extensively to examine striatal activation in both adult and adolescent populations. The current study used this task with a longitudinal approach across mid-adolescence and late adolescence/early adulthood. Twenty-two participants (13 male) were studied using the MID task at two time-points, once in mid-adolescence (mean age=16.11; SD=1.44) and a second time in late adolescence/early adulthood (mean age=20.14; SD=.67). Results revealed greater striatal activation with increased age in high- compared to low-incentive contexts (incentive magnitude), for gain as well as for loss trials (incentive valence). Results extend cross-sectional findings and show reduced striatal engagement in adolescence compared to adulthood during preparation for action in an incentive context.

  2. Loss of ATP-dependent transport activity in pseudoxanthoma elasticum-associated mutants of human ABCC6 (MRP6).

    PubMed

    Iliás, Attila; Urbán, Zsolt; Seidl, Thomas L; Le Saux, Olivier; Sinkó, Emese; Boyd, Charles D; Sarkadi, Balázs; Váradi, András

    2002-05-10

    Mutations in the ABCC6 (MRP6) gene cause pseudoxanthoma elasticum (PXE), a rare heritable disorder resulting in the calcification of elastic fibers. In the present study a cDNA encoding a full-length normal variant of ABCC6 was amplified from a human kidney cDNA library, and the protein was expressed in Sf9 insect cells. In isolated membranes ATP binding as well as ATP-dependent active transport by ABCC6 was demonstrated. We found that glutathione conjugates, including leukotriene C(4) and N-ethylmaleimide S-glutathione (NEM-GS), were actively transported by human ABCC6. Organic anions (probenecid, benzbromarone, indomethacin), known to interfere with glutathione conjugate transport of human ABCC1 and ABCC2, inhibited the ABCC6-mediated NEM-GS transport in a specific manner, indicating that ABCC6 has a unique substrate specificity. We have also expressed three missense mutant forms of ABCC6, which have recently been shown to cause PXE. MgATP binding was normal in these proteins; ATP-dependent NEM-GS or leukotriene C(4) transport, however, was abolished. Our data indicate that human ABCC6 is a primary active transporter for organic anions. In the three ABCC6 mutant forms examined, the loss of transport activity suggests that these mutations result in a PXE phenotype through a direct influence on the transport activity of this ABC transporter.

  3. Retina-specific activation of a sustained hypoxia-like response leads to severe retinal degeneration and loss of vision.

    PubMed

    Lange, Christina; Caprara, Christian; Tanimoto, Naoyuki; Beck, Susanne; Huber, Gesine; Samardzija, Marijana; Seeliger, Mathias; Grimm, Christian

    2011-01-01

    Loss of vision and blindness in human patients is often caused by the degeneration of neuronal cells in the retina. In mouse models, photoreceptors can be protected from death by hypoxic preconditioning. Preconditioning in low oxygen stabilizes and activates hypoxia inducible transcription factors (HIFs), which play a major role in the hypoxic response of tissues including the retina. We show that a tissue-specific knockdown of von Hippel-Lindau protein (VHL) activated HIF transcription factors in normoxic conditions in the retina. Sustained activation of HIF1 and HIF2 was accompanied by persisting embryonic vasculatures in the posterior eye and the iris. Embryonic vessels persisted into adulthood and led to a severely abnormal mature vessel system with vessels penetrating the photoreceptor layer in adult mice. The sustained hypoxia-like response also activated the leukemia inhibitory factor (LIF)-controlled endogenous molecular cell survival pathway. However, this was not sufficient to protect the retina against massive cell death in all retinal layers of adult mice. Caspases 1, 3 and 8 were upregulated during the degeneration as were several VHL target genes connected to the extracellular matrix. Misregulation of these genes may influence retinal structure and may therefore facilitate growth of vessels into the photoreceptor layer. Thus, an early and sustained activation of a hypoxia-like response in retinal cells leads to abnormal vasculature and severe retinal degeneration in the adult mouse retina.

  4. Loss of CARD9-mediated innate activation attenuates severe influenza pneumonia without compromising host viral immunity

    PubMed Central

    Uematsu, Takayuki; Iizasa, Ei’ichi; Kobayashi, Noritada; Yoshida, Hiroki; Hara, Hiromitsu

    2015-01-01

    Influenza virus (IFV) infection is a common cause of severe viral pneumonia associated with acute respiratory distress syndrome (ARDS), which is difficult to control with general immunosuppressive therapy including corticosteroids due to the unfavorable effect on viral replication. Studies have suggested that the excessive activation of the innate immunity by IFV is responsible for severe pathologies. In this study, we focused on CARD9, a signaling adaptor known to regulate innate immune activation through multiple innate sensor proteins, and investigated its role in anti-IFV defense and lung pathogenesis in a mouse model recapitulating severe influenza pneumonia with ARDS. We found that influenza pneumonia was dramatically attenuated in Card9-deficient mice, which showed improved mortality with reduced inflammatory cytokines and chemokines in the infected lungs. However, viral clearance, type-I interferon production, and the development of anti-viral B and T cell immunity were not compromised by CARD9 deficiency. Syk or CARD9-deficient DCs but not macrophages showed impaired cytokine but not type-I interferon production in response to IFV in vitro, indicating a possible role for the Syk-CARD9 pathway in DCs in excessive inflammation of IFV-infected lungs. Therefore, inhibition of this pathway is an ideal therapeutic target for severe influenza pneumonia without affecting viral clearance. PMID:26627732

  5. Loss of Pancreas upon Activated Wnt Signaling Is Concomitant with Emergence of Gastrointestinal Identity

    PubMed Central

    Herrero-Martin, Griselda; Puri, Sapna; Taketo, Makoto Mark; Rojas, Anabel; Hebrok, Matthias; Cano, David A.

    2016-01-01

    Organ formation is achieved through the complex interplay between signaling pathways and transcriptional cascades. The canonical Wnt signaling pathway plays multiple roles during embryonic development including patterning, proliferation and differentiation in distinct tissues. Previous studies have established the importance of this pathway at multiple stages of pancreas formation as well as in postnatal organ function and homeostasis. In mice, gain-of-function experiments have demonstrated that activation of the canonical Wnt pathway results in pancreatic hypoplasia, a phenomenon whose underlying mechanisms remains to be elucidated. Here, we show that ectopic activation of epithelial canonical Wnt signaling causes aberrant induction of gastric and intestinal markers both in the pancreatic epithelium and mesenchyme, leading to the development of gut-like features. Furthermore, we provide evidence that β -catenin-induced impairment of pancreas formation depends on Hedgehog signaling. Together, our data emphasize the developmental plasticity of pancreatic progenitors and further underscore the key role of precise regulation of signaling pathways to maintain appropriate organ boundaries. PMID:27736991

  6. Loss of Pancreas upon Activated Wnt Signaling Is Concomitant with Emergence of Gastrointestinal Identity.

    PubMed

    Muñoz-Bravo, Jose Luis; Flores-Martínez, Alvaro; Herrero-Martin, Griselda; Puri, Sapna; Taketo, Makoto Mark; Rojas, Anabel; Hebrok, Matthias; Cano, David A

    2016-01-01

    Organ formation is achieved through the complex interplay between signaling pathways and transcriptional cascades. The canonical Wnt signaling pathway plays multiple roles during embryonic development including patterning, proliferation and differentiation in distinct tissues. Previous studies have established the importance of this pathway at multiple stages of pancreas formation as well as in postnatal organ function and homeostasis. In mice, gain-of-function experiments have demonstrated that activation of the canonical Wnt pathway results in pancreatic hypoplasia, a phenomenon whose underlying mechanisms remains to be elucidated. Here, we show that ectopic activation of epithelial canonical Wnt signaling causes aberrant induction of gastric and intestinal markers both in the pancreatic epithelium and mesenchyme, leading to the development of gut-like features. Furthermore, we provide evidence that β -catenin-induced impairment of pancreas formation depends on Hedgehog signaling. Together, our data emphasize the developmental plasticity of pancreatic progenitors and further underscore the key role of precise regulation of signaling pathways to maintain appropriate organ boundaries.

  7. Active power control of solar PV generation for large interconnection frequency regulation and oscillation damping

    DOE PAGES

    Liu, Yong; Zhu, Lin; Zhan, Lingwei; ...

    2015-06-23

    Because of zero greenhouse gas emission and decreased manufacture cost, solar photovoltaic (PV) generation is expected to account for a significant portion of future power grid generation portfolio. Because it is indirectly connected to the power grid via power electronic devices, solar PV generation system is fully decoupled from the power grid, which will influence the interconnected power grid dynamic characteristics as a result. In this study, the impact of solar PV penetration on large interconnected power system frequency response and inter-area oscillation is evaluated, taking the United States Eastern Interconnection (EI) as an example. Furthermore, based on the constructedmore » solar PV electrical control model with additional active power control loops, the potential contributions of solar PV generation to power system frequency regulation and oscillation damping are examined. The advantages of solar PV frequency support over that of wind generator are also discussed. Finally, simulation results demonstrate that solar PV generations can effectively work as ‘actuators’ in alleviating the negative impacts they bring about.« less

  8. Active power control of solar PV generation for large interconnection frequency regulation and oscillation damping

    SciTech Connect

    Liu, Yong; Zhu, Lin; Zhan, Lingwei; Gracia, Jose R.; King, Thomas Jr.; Liu, Yilu

    2015-06-23

    Because of zero greenhouse gas emission and decreased manufacture cost, solar photovoltaic (PV) generation is expected to account for a significant portion of future power grid generation portfolio. Because it is indirectly connected to the power grid via power electronic devices, solar PV generation system is fully decoupled from the power grid, which will influence the interconnected power grid dynamic characteristics as a result. In this study, the impact of solar PV penetration on large interconnected power system frequency response and inter-area oscillation is evaluated, taking the United States Eastern Interconnection (EI) as an example. Furthermore, based on the constructed solar PV electrical control model with additional active power control loops, the potential contributions of solar PV generation to power system frequency regulation and oscillation damping are examined. The advantages of solar PV frequency support over that of wind generator are also discussed. Finally, simulation results demonstrate that solar PV generations can effectively work as ‘actuators’ in alleviating the negative impacts they bring about.

  9. TGFβ loss activates ADAMTS-1-mediated EGF-dependent invasion in a model of esophageal cell invasion

    SciTech Connect

    Le Bras, Grégoire F.; Taylor, Chase; Koumangoye, Rainelli B.; Revetta, Frank; Loomans, Holli A.; Andl, Claudia D.

    2015-01-01

    The TGFβ signaling pathway is essential to epithelial homeostasis and is often inhibited during progression of esophageal squamous cell carcinoma. Recently, an important role for TGFβ signaling has been described in the crosstalk between epithelial and stromal cells regulating squamous tumor cell invasion in mouse models of head-and-neck squamous cell carcinoma (HNSCC). Loss of TGFβ signaling, in either compartment, leads to HNSCC however, the mechanisms involved are not well understood. Using organotypic reconstruct cultures (OTC) to model the interaction between epithelial and stromal cells that occur in dysplastic lesions, we show that loss of TGFβ signaling promotes an invasive phenotype in both fibroblast and epithelial compartments. Employing immortalized esophageal keratinocytes established to reproduce common mutations of esophageal squamous cell carcinoma, we show that treatment of OTC with inhibitors of TGFβ signaling (A83-01 or SB431542) enhances invasion of epithelial cells into a fibroblast-embedded Matrigel/collagen I matrix. Invasion induced by A83-01 is independent of proliferation but relies on protease activity and expression of ADAMTS-1 and can be altered by matrix density. This invasion was associated with increased expression of pro-inflammatory cytokines, IL1 and EGFR ligands HB-EGF and TGFα. Altering EGF signaling prevented or induced epithelial cell invasion in this model. Loss of expression of the TGFβ target gene ROBO1 suggested that chemorepulsion may regulate keratinocyte invasion. Taken together, our data show increased invasion through inhibition of TGFβ signaling altered epithelial-fibroblasts interactions, repressing markers of activated fibroblasts, and altering integrin-fibronectin interactions. These results suggest that inhibition of TGFβ signaling modulates an array of pathways that combined promote multiple aspects of tumor invasion. - Highlights: • Chemical inhibition of TGFβ signaling advances collective invasion

  10. Control of a Shunt Active Power Filter with Neural Networks—Theory and Practical Results

    NASA Astrophysics Data System (ADS)

    Villalva, Marcelo G.; Filho, Ernesto Ruppert

    This paper presents theoretical studies and practical results obtained with a four-wire shunt active power filter fully controlled with neural networks. The paper is focused on a current compensation method based on adaptive linear elements (adalines), which are powerful and easy-to-use neural networks. The reader will find here an introduction about these networks, an explanatory section about the achievement of Fourier series with adalines, and the full description of an adaline-based selective current compensator. The paper also brings a quick discussion about the use of a feedforward neural network in the current controller of the active filter, as well as simulation and experimental results obtained with the prototype of an active power filter.

  11. Loss of circadian rhythmicity in body temperature and locomotor activity following suprachiasmatic lesions in the rat

    NASA Technical Reports Server (NTRS)

    Saleh, M. A.; Haro, P. J.; Winget, C. M.

    1977-01-01

    In experiments on male and female ambulatory rats, the effect of bilateral suprachiasmatic lesions on deep body temperature and locomotor activity circadian rhythms was investigated. A L/D:12/12 cycle and 23 C ambient temperature were maintained. One-half of the rats received radiofrequency lesions in the suprachiasmic nucleus (SCN) while the second group were sham operated by lowering the radiofrequency electrode to the SCN without producing electrolytic lesions. Four weeks were allowed for recuperation. Autopsies were conducted to make sure that the lesions were restricted to SCN. The results show the complete disappearance of circadian rhythm in the SCN lesioned rats and only a slight diminution for the sham operated rats.

  12. Active Oxygen Generator by Silent Discharge and Oxidation Power in Formation of Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaaki; Kawagoe, Yasuyuki; Tsukazaki, Hisashi; Yamanishi, Kenichiro

    We have studied the low pressure silent discharge type active oxygen generator in terms of the application to the formation of oxide thin films. In this paper the oxidation power of active oxygen in the oxide thin film formation is compared with that of oxygen and ozone by forming silicon oxide thin films. It was confirmed that the oxidation power is in turn of active oxygen > ozone > oxygen from the experimental result of the number of x in SiOx thin film. Furthermore we applied active oxygen to the formation of the thin film high temperature super conductor and active oxygen was found to be effective to the formation of the thin film with high performance.

  13. An activating Pik3ca mutation coupled with Pten loss is sufficient to initiate ovarian tumorigenesis in mice.

    PubMed

    Kinross, Kathryn M; Montgomery, Karen G; Kleinschmidt, Margarete; Waring, Paul; Ivetac, Ivan; Tikoo, Anjali; Saad, Mirette; Hare, Lauren; Roh, Vincent; Mantamadiotis, Theo; Sheppard, Karen E; Ryland, Georgina L; Campbell, Ian G; Gorringe, Kylie L; Christensen, James G; Cullinane, Carleen; Hicks, Rodney J; Pearson, Richard B; Johnstone, Ricky W; McArthur, Grant A; Phillips, Wayne A

    2012-02-01

    Mutations in the gene encoding the p110α subunit of PI3K (PIK3CA) that result in enhanced PI3K activity are frequently observed in human cancers. To better understand the role of mutant PIK3CA in the initiation or progression of tumorigenesis, we generated mice in which a PIK3CA mutation commonly detected in human cancers (the H1047R mutation) could be conditionally knocked into the endogenous Pik3ca locus. Activation of this mutation in the mouse ovary revealed that alone, Pik3caH1047R induced premalignant hyperplasia of the ovarian surface epithelium but no tumors. Concomitantly, we analyzed several human ovarian cancers and found PIK3CA mutations coexistent with KRAS and/or PTEN mutations, raising the possibility that a secondary defect in a co-regulator of PI3K activity may be required for mutant PIK3CA to promote transformation. Consistent with this notion, we found that Pik3caH1047R mutation plus Pten deletion in the mouse ovary led to the development of ovarian serous adenocarcinomas and granulosa cell tumors. Both mutational events were required for early, robust Akt activation. Pharmacological inhibition of PI3K/mTOR in these mice delayed tumor growth and prolonged survival. These results demonstrate that the Pik3caH1047R mutation with loss of Pten is enough to promote ovarian cell transformation and that we have developed a model system for studying possible therapies.

  14. Nitrogen depletion in the fission yeast Schizosaccharomyces pombe causes nucleosome loss in both promoters and coding regions of activated genes

    PubMed Central

    Kristell, Carolina; Orzechowski Westholm, Jakub; Olsson, Ida; Ronne, Hans; Komorowski, Jan; Bjerling, Pernilla

    2010-01-01

    Gene transcription is associated with local changes in chromatin, both in nucleosome positions and in chemical modifications of the histones. Chromatin dynamics has mostly been studied on a single-gene basis. Those genome-wide studies that have been made primarily investigated steady-state transcription. However, three studies of genome-wide changes in chromatin during the transcriptional response to heat shock in the budding yeast Saccharomyces cerevisiae revealed nucleosome eviction in promoter regions but only minor effects in coding regions. Here, we describe the short-term response to nitrogen starvation in the fission yeast Schizosaccharomyces pombe. Nitrogen depletion leads to a fast induction of a large number of genes in S. pombe and is thus suitable for genome-wide studies of chromatin dynamics during gene regulation. After 20 min of nitrogen removal, 118 transcripts were up-regulated. The distribution of regulated genes throughout the genome was not random; many up-regulated genes were found in clusters, while large parts of the genome were devoid of up-regulated genes. Surprisingly, this up-regulation was associated with nucleosome eviction of equal magnitudes in the promoters and in the coding regions. The nucleosome loss was not limited to induction by nitrogen depletion but also occurred during cadmium treatment. Furthermore, the lower nucleosome density persisted for at least 60 min after induction. Two highly induced genes, urg1+ and urg2+, displayed a substantial nucleosome loss, with only 20% of the nucleosomes being left in the coding region. We conclude that nucleosome loss during transcriptional activation is not necessarily limited to promoter regions. PMID:20086243

  15. Spinal cord injury causes bone loss through peroxisome proliferator-activated receptor-γ and Wnt signalling

    PubMed Central

    Yan, Jun; Li, Bo; Chen, Jiang-Wei; Jiang, Sheng-Dan; Jiang, Lei-Sheng

    2012-01-01

    It has long been recognized that spinal cord injury (SCI) leads to a loss of bone mineral. However, the mechanisms of bone loss after SCI remain poorly understood. The aim of this study was to investigate whether SCI causes a shift in skeletal balance between osteoblastogenesis and adipogenesis. Eighty male Sprague-Dawley rats at 6 weeks of age were randomly divided into two groups: sham-operated (SHAM) group and SCI group. The rats were killed after 3 weeks, 3 months and 6 months, and their femora, tibiae and humeri were collected for mesenchymal stem cells (MSCs) culture, bone mineral density (BMD) measurement, RNA analysis and Western Blot analysis. Osteogenic and adipogenic differentiation potential of MSCs from SCI rats and SHAM rats was evaluated. We found increased marrow adiposity in sublesional tibiae of SCI rats. SCI caused increased peroxisome proliferator-activated receptor-γ (PPARγ) expression and diminished Wnt signalling in sublesional tibiae. Interestingly, in MSCs from SCI rats treated with the PPARγ inhibitor GW9662, the ratios of RANKL to OPG expression were significantly decreased. On the contrary, in MSCs from SCI rats treated with the PPARγ ligand troglitazone, the ratios of RANKL to OPG expression in SCI rats were significantly increased. High expression of PPARγ may lead to increased bone resorption through the RANKL/OPG axis after SCI. In addition, high expression also results in the suppression of osteogenesis and enhancement of adipogenesis in SCI rats. SCI causes a shift in skeletal balance between osteoblastogenesis and adipogenesis, thus leading to bone loss after SCI. PMID:22947224

  16. Energy- and Activity-Dependent Loss Timescales for Inner Magnetospheric keV-Energy Electrons

    NASA Astrophysics Data System (ADS)

    Liemohn, M. W.

    2011-12-01

    The Hot Electron and Ion Drift Integrator (HEIDI) inner magnetospheric drift physics model has recently been modified to include keV-energy electron scattering rates by VLF chorus and hiss waves, thus allowing for the calculation of the electron phase space distribution in the inner magnetosphere and electron precipitation to the upper atmosphere. Comparisons of calculated electron fluxes are made with low-Earth orbit electron precipitation data and dayside electron measurements to validate the scattering implementation procedure. The energy-dependent scattering rate coefficients are adjusted to take into account geomagnetic activity and plasmapause location, providing a scattering rate that best matches the simulations to the observed electron fluxes. In addition, the electron ring current intensities and spatio-temporal evolution are compared against simulation results for the hot ion species. While the electron total energy content is typically 10 times smaller than the ion total energy content in the inner magnetosphere, it can be significantly higher than this during the late main phase of magnetic storms.

  17. Loss of UCP2 Attenuates Mitochondrial Dysfunction without Altering ROS Production and Uncoupling Activity

    PubMed Central

    Kukat, Alexandra; Dogan, Sukru Anil; Edgar, Daniel; Mourier, Arnaud; Jacoby, Christoph; Maiti, Priyanka; Mauer, Jan; Becker, Christina; Senft, Katharina; Wibom, Rolf; Kudin, Alexei P.; Hultenby, Kjell; Flögel, Ulrich; Rosenkranz, Stephan; Ricquier, Daniel; Kunz, Wolfram S.; Trifunovic, Aleksandra

    2014-01-01

    Although mitochondrial dysfunction is often accompanied by excessive reactive oxygen species (ROS) production, we previously showed that an increase in random somatic mtDNA mutations does not result in increased oxidative stress. Normal levels of ROS and oxidative stress could also be a result of an active compensatory mechanism such as a mild increase in proton leak. Uncoupling protein 2 (UCP2) was proposed to play such a role in many physiological situations. However, we show that upregulation of UCP2 in mtDNA mutator mice is not associated with altered proton leak kinetics or ROS production, challenging the current view on the role of UCP2 in energy metabolism. Instead, our results argue that high UCP2 levels allow better utilization of fatty acid oxidation resulting in a beneficial effect on mitochondrial function in heart, postponing systemic lactic acidosis and resulting in longer lifespan in these mice. This study proposes a novel mechanism for an adaptive response to mitochondrial cardiomyopathy that links changes in metabolism to amelioration of respiratory chain deficiency and longer lifespan. PMID:24945157

  18. Photovoltaic array loss mechanisms

    NASA Astrophysics Data System (ADS)

    Gonzalez, Charles

    1986-10-01

    Loss mechanisms which come into play when solar cell modules are mounted in arrays are identified. Losses can occur either from a reduction in the array electrical performance or with nonoptimal extraction of power from the array. Electrical performance degradation is caused by electrical mismatch, transmission losses from cell surface soiling and steep angle of reflectance, and electrical losses from field wiring resistance and the voltage drop across blocking diodes. The second type of loss, concerned with the operating points of the array, can involve nonoptimal load impedance and limiting the operating envelope of the array to specific ranges of voltage and current. Each of the loss mechanisms are discussed and average energy losses expected from soiling, steep reflectance angles and circuit losses are calculated.

  19. A study on actuation power flow produced in an active damping system

    NASA Astrophysics Data System (ADS)

    Horodinca, Mihaita

    2013-08-01

    This paper aims to present some new features of the experimental research in dynamics of a closed-loop actively controlled mechanical system with collocated PZT sensor and actuator and a proportional-derivative regulator. The evolution of active electrical power absorbed by the actuator is mainly used. A fraction of this power is converted into mechanical real power and delivered by the actuator to the mechanical system. This paper highlights the fact that derivative gain in the regulator produces a directly proportional synthetic damping (positive or negative) in the mechanical system, due to the fact that a directly proportional flow of active electrical power (negative or positive) absorbed by the actuator is generated. The paper proves that the active power flow evolution is very useful to describe the behavior of the actuator for some dynamic regimes (more useful than the magnitude of the electrical impedance). The research was done on a setup that consists of an aluminium cantilever beam equipped with two PZT collocated transducers - rectangular laminar design - closely glued by the rigidly fixed end of the beam. The feedback between sensor and actuator is provided by a regulator which produces a tunable phase difference between input and output (equivalent to a proportional-derivative feedback). The electrical current and the voltage generated by the regulator and applied to the actuator are used for finding the values of the active electrical power absorbed by the actuator, the magnitude of the electrical impedance and the values of some dynamic parameters of the cantilever (e.g. damping ratio, damped modal frequency, etc.) due to an external excitation of first bending mode. A computer assisted data acquisition system and some new data processing techniques are used for these purposes.

  20. NOX3 NADPH Oxidase Couples Transient Receptor Potential Vanilloid 1 to Signal Transducer and Activator of Transcription 1-Mediated Inflammation and Hearing Loss

    PubMed Central

    Mukherjea, Debashree; Jajoo, Sarvesh; Sheehan, Kelly; Kaur, Tejbeer; Sheth, Sandeep; Bunch, Jennifer; Perro, Christopher; Rybak, Leonard P.

    2011-01-01

    Abstract Transient receptor potential vanilloid 1 (TRPV1) is implicated in cisplatin ototoxicity. Activation of this channel by cisplatin increases reactive oxygen species generation, which contribute to loss of outer hair cells in the cochlea. Knockdown of TRPV1 by short interfering RNA protected against cisplatin ototoxicity. In this study, we examined the mechanism underlying TRPV1-mediated ototoxicity using cultured organ of Corti transformed cells (UB/OC-1) and rats. Trans-tympanic injections of capsaicin produced transient hearing loss within 24 h, which recovered by 72 h. In UB/OC-1 cells, capsaicin increased NOX3 NADPH oxidase activity and activation of signal transducer and activator of transcription 1 (STAT1). Intratympanic administration of capsaicin transiently increased STAT1 activity and expression of downstream proinflammatory molecules. Capsaicin produced a transient increase in CD14-positive inflammatory cells into the cochlea, which mimicked the temporal course of STAT1 activation but did not alter the expression of apoptotic genes or damage to outer hair cells. In addition, trans-tympanic administration of STAT1 short interfering RNA protected against capsaicin-induced hearing loss. These data suggest that activation of TRPV1 mediates temporary hearing loss by initiating an inflammatory process in the cochlea via activation of NOX3 and STAT1. Thus, these proteins represent reasonable targets for ameliorating hearing loss. Antioxid. Redox Signal. 14, 999–1010. PMID:20712533

  1. NOX3 NADPH oxidase couples transient receptor potential vanilloid 1 to signal transducer and activator of transcription 1-mediated inflammation and hearing loss.

    PubMed

    Mukherjea, Debashree; Jajoo, Sarvesh; Sheehan, Kelly; Kaur, Tejbeer; Sheth, Sandeep; Bunch, Jennifer; Perro, Christopher; Rybak, Leonard P; Ramkumar, Vickram

    2011-03-15

    Transient receptor potential vanilloid 1 (TRPV1) is implicated in cisplatin ototoxicity. Activation of this channel by cisplatin increases reactive oxygen species generation, which contribute to loss of outer hair cells in the cochlea. Knockdown of TRPV1 by short interfering RNA protected against cisplatin ototoxicity. In this study, we examined the mechanism underlying TRPV1-mediated ototoxicity using cultured organ of Corti transformed cells (UB/OC-1) and rats. Trans-tympanic injections of capsaicin produced transient hearing loss within 24 h, which recovered by 72 h. In UB/OC-1 cells, capsaicin increased NOX3 NADPH oxidase activity and activation of signal transducer and activator of transcription 1 (STAT1). Intratympanic administration of capsaicin transiently increased STAT1 activity and expression of downstream proinflammatory molecules. Capsaicin produced a transient increase in CD14-positive inflammatory cells into the cochlea, which mimicked the temporal course of STAT1 activation but did not alter the expression of apoptotic genes or damage to outer hair cells. In addition, trans-tympanic administration of STAT1 short interfering RNA protected against capsaicin-induced hearing loss. These data suggest that activation of TRPV1 mediates temporary hearing loss by initiating an inflammatory process in the cochlea via activation of NOX3 and STAT1. Thus, these proteins represent reasonable targets for ameliorating hearing loss.

  2. Optimization of Passive and Active Non-Linear Vibration Mounting Systems Based on Vibratory Power Transmission

    NASA Astrophysics Data System (ADS)

    Royston, T. J.; Singh, R.

    1996-07-01

    While significant non-linear behavior has been observed in many vibration mounting applications, most design studies are typically based on the concept of linear system theory in terms of force or motion transmissibility. In this paper, an improved analytical strategy is presented for the design optimization of complex, active of passive, non-linear mounting systems. This strategy is built upon the computational Galerkin method of weighted residuals, and incorporates order reduction and numerical continuation in an iterative optimization scheme. The overall dynamic characteristics of the mounting system are considered and vibratory power transmission is minimized via adjustment of mount parameters by using both passive and active means. The method is first applied through a computational example case to the optimization of basic passive and active, non-linear isolation configurations. It is found that either active control or intentionally introduced non-linearity can improve the mount's performance; but a combination of both produces the greatest benefit. Next, a novel experimental, active, non-linear isolation system is studied. The effect of non-linearity on vibratory power transmission and active control are assessed via experimental measurements and the enhanced Galerkin method. Results show how harmonic excitation can result in multiharmonic vibratory power transmission. The proposed optimization strategy offers designers some flexibility in utilizing both passive and active means in combination with linear and non-linear components for improved vibration mounts.

  3. Loss of contractile activity of endothelin-1 induced by electrical field stimulation-generated free radicals.

    PubMed

    Yasuda, N; Kasuya, Y; Yamada, G; Hama, H; Masaki, T; Goto, K

    1994-09-01

    1. Electrical field stimulation (EFS; 10 V, 10 Hz, 2 ms) of porcine coronary artery strips precontracted with 10 nM endothelin-1 (ET-1) for 5 min caused a biphasic response, consisting of a slight contraction during EFS and a marked and irreversible relaxation just after EFS. This irreversible relaxation after EFS has never been investigated. In the present study, we have investigated the mechanism of the relaxation after EFS. 2. The EFS-induced response was not affected by the presence or absence of endothelium and was insensitive to 10 microM tetrodotoxin (TTX). 3. In the presence of free radical scavengers (40 u ml-1 superoxide dismutase (SOD), 1200 u ml-1 catalase or 80 mM D-mannitol), the relaxation after EFS was significantly inhibited. Moreover, relaxation after EFS was not observed in porcine coronary artery strips precontracted with 20 mM KCl. 4. In a cascade experiment, EFS of Krebs-Ringer solution containing 10 nM ET-1 induced marked suppression of the contractile activity of ET-1 in porcine coronary artery strips, which was in accord with the observed decrease in release of immunoreactive ET-1 (ir-ET-1). This effect of EFS was significantly inhibited by each of the free radical scavengers, 3 mM vitamin C, 40 u ml-1 SOD, 1200 u ml-1 catalase and 80 mM D-mannitol. 5. The exchange of 95% O2/5% CO2 gas for 95% N2/5% CO2 gas significantly inhibited the EFS-induced decrease in release of ir-ET-1. 6. Neither superoxide anions generated by xanthine (10 JM) plus xanthine oxidase (0.1 micro ml-1) nor hydrogen peroxide (10 microM) exogenously added to Krebs-Ringer solution containing 10 nM ET-1 affected the level of ir-ET-1.7. Generation of hydroxyl radicals was detected in the EFS-applied Krebs-Ringer solution. The EFS-induced generation of hydroxyl radicals was dependent on the period of stimulation and 02-bubbling, and significant generation of hydroxyl radicals was detectable with stimulation of over 5 min.Moreover, hydroxyl radicals generated in 50 mM Na

  4. 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.

  5. Frontal predominance of a relative increase in sleep delta and theta EEG activity after sleep loss in humans

    NASA Technical Reports Server (NTRS)

    Cajochen, C.; Foy, R.; Dijk, D. J.; Czeisler, C. A. (Principal Investigator)

    1999-01-01

    The effect of sleep deprivation (40 h) on topographic and temporal aspects of electroencephalographic (EEG) activity during sleep was investigated by all night spectral analysis in six young volunteers. The sleep-deprivation-induced increase of EEG power density in the delta and theta frequencies (1-7 Hz) during nonREM sleep, assessed along the antero-posterior axis (midline: Fz, Cz, Pz, Oz), was significantly larger in the more frontal derivations (Fz, Cz) than in the more parietal derivations (Pz, Oz). This frequency-specific frontal predominance was already present in the first 30 min of recovery sleep, and dissipated in the course of the 8-h sleep episode. The data demonstrate that the enhancement of slow wave EEG activity during sleep following extended wakefulness is most pronounced in frontal cortical areas.

  6. Cholesteryl Ester Accumulation Induced by PTEN Loss and PI3K/AKT Activation Underlies Human Prostate Cancer Aggressiveness

    PubMed Central

    Yue, Shuhua; Li, Junjie; Lee, Seung-Young; Lee, Hyeon Jeong; Shao, Tian; Song, Bing; Cheng, Liang; Masterson, Timothy A.; Liu, Xiaoqi; Ratliff, Timothy L.; Cheng, Ji-Xin

    2014-01-01

    Summary Altered lipid metabolism is increasingly recognized as a signature of cancer cells. Enabled by label-free Raman spectromicroscopy, we performed quantitative analysis of lipogenesis at single cell level in human patient cancerous tissues. Our imaging data revealed an unexpected, aberrant accumulation of esterified cholesterol in lipid droplets of high-grade prostate cancer and metastases. Biochemical study showed that such cholesteryl ester accumulation was a consequence of loss of tumor suppressor PTEN and subsequent activation of PI3K/AKT pathway in prostate cancer cells. Furthermore, we found that such accumulation arose from significantly enhanced uptake of exogenous lipoproteins and required cholesterol esterification. Depletion of cholesteryl ester storage significantly reduced cancer proliferation, impaired cancer invasion capability, and suppressed tumor growth in mouse xenograft models with negligible toxicity. These findings open opportunities for diagnosing and treating prostate cancer by targeting the altered cholesterol metabolism. PMID:24606897

  7. Weight loss and physical activity for disease prevention in obese older adults: an important role for lifestyle management.

    PubMed

    Valencia, Willy Marcos; Stoutenberg, Mark; Florez, Hermes

    2014-10-01

    Weight loss in older adults has been a controversial topic for more than a decade. An obesity paradox has been previously described and the issue of weight status on health outcomes remains a highly debated topic. However, there is little doubt that physical activity (PA) has a myriad of benefits in older adults, especially in obese individuals who are inactive and have a poor cardiometabolic profile. In this review, we offer a critical view to clarify misunderstandings regarding the obesity paradox, particularly as it relates to obese older adults. We also review the evidence on PA and lifestyle interventions for the improvement of cardiorespiratory fitness, which can prevent disease and provide benefits to obese older adults, independent of weight changes.

  8. COUPLING THE SOLAR DYNAMO AND THE CORONA: WIND PROPERTIES, MASS, AND MOMENTUM LOSSES DURING AN ACTIVITY CYCLE

    SciTech Connect

    Pinto, Rui F.; Brun, Allan Sacha; Grappin, Roland

    2011-08-20

    We study the connections between the Sun's convection zone and the evolution of the solar wind and corona. We let the magnetic fields generated by a 2.5-dimensional (2.5D) axisymmetric kinematic dynamo code (STELEM) evolve in a 2.5D axisymmetric coronal isothermal magnetohydrodynamic code (DIP). The computations cover an 11 year activity cycle. The solar wind's asymptotic velocity varies in latitude and in time in good agreement with the available observations. The magnetic polarity reversal happens at different paces at different coronal heights. Overall the Sun's mass-loss rate, momentum flux, and magnetic braking torque vary considerably throughout the cycle. This cyclic modulation is determined by the latitudinal distribution of the sources of open flux and solar wind and the geometry of the Alfven surface. Wind sources and braking torque application zones also vary accordingly.

  9. Research on power equalization using a low-loss DC-DC chopper for lithium-ion batteries in electric vehicle

    NASA Astrophysics Data System (ADS)

    Wei, Y. W.; Liu, G. T.; Xiong, S. N.; Cheng, J. Z.; Huang, Y. H.

    2017-01-01

    In the near future, electric vehicle is entirely possible to replace traditional cars due to its zero pollution, small power consumption and low noise. Lithium-ion battery, which owns lots of advantages such as lighter and larger capacity and longer life, has been widely equipped in different electric cars all over the world. One disadvantage of this energy storage device is state of charge (SOC) difference among these cells in each series branch. If equalization circuit is not allocated for series-connected batteries, its safety and lifetime are declined due to over-charge or over-discharge happened, unavoidably. In this paper, a novel modularized equalization circuit, based on DC-DC chopper, is proposed to supply zero loss in theory. The proposed circuit works as an equalizer when Lithium-ion battery pack is charging or discharging or standing idle. Theoretical analysis and control method have been finished, respectively. Simulation and small scale experiments are applied to verify its real effect.

  10. Adenovirus 36 Attenuates Weight Loss from Exercise but Improves Glycemic Control by Increasing Mitochondrial Activity in the Liver

    PubMed Central

    Ye, Michael B.; Park, Sooho; Kim, In-Beom; Nam, Jae-Hwan

    2014-01-01

    Human adenovirus type 36 (Ad36) as an obesity agent induces adiposity by increasing glucose uptake and promoting chronic inflammation in fat tissues; in contrast, exercise reduces total body fat and inflammation. Our objective was to determine the association between Ad36 and the effects of exercise on inflammation and glycemic control. In the human trials (n = 54), Korean children (aged 12–14 years) exercised for 60 min on three occasions each week for 2 months. We compared the body mass index (BMI) Z-scores before and after exercise. C57BL/6 mice were infected with Ad36 and Ad2 as a control, and these mice exercised for 12 weeks postinfection. After the exercise period, we determined the serum parameters and assessed the presence of inflammation and the mitochondrial function in the organs. Ad36-seropositive children who were subjected to a supervised exercise regimen had high BMI Z-scores whereas Ad36-seronegative children had lower scores. Similarly, Ad36-infected mice were resistant to weight loss and exhibited chronic inflammation of their adipose tissues despite frequent exercise. However, Ad36 combined with exercise reduced the levels of serum glucose, nonesterified fatty acids, total cholesterol, and insulin in virus-infected mice. Interestingly, virus infection increased the mitochondrial function in the liver, as demonstrated by the numbers of mitochondria, cytochrome c oxidase activity, and transcription of key mitochondrial genes. Therefore Ad36 counteracts the weight-loss effect of exercise and maintains the chronic inflammatory state, but glycemic control is improved by exercise synergistically because of increased mitochondrial activity in the liver. PMID:25479564

  11. 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.

  12. 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.

  13. T & I--Electricity. Power. Kit No. 52. Instructor's Manual [and] Student Learning Activity Guide.

    ERIC Educational Resources Information Center

    Jones, Phillip

    An instructor's manual and student activity guide on electrical power 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…

  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.

  16. 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…

  17. The Effect of Active Recovery on Power Performance During the Bench Press Exercise

    PubMed Central

    Lopes, Felipe A. S.; Panissa, Valéria L. G.; Julio, Ursula F.; Menegon, Elton M.; Franchini, Emerson

    2014-01-01

    The objective of this study was to verify the effect of active and passive recovery on blood lactate concentration and power performance. Twelve male subjects were submitted to a maximal strength test in the the bench press, a maximal aerobic test in the bench step, and to four sets of bench press exercise performed as fast and as long as possible, using 80% of maximal strength when active or passive recovery was performed. The maximum number of repetitions, mean and peak power in eccentric and concentric phases were computed and blood lactate concentration was measured. Comparisons for the variables were made using a two-way variance analysis (recovery type and set numer) with repeated measures in the second factor. When significant differences were detected (p < 0.05), a Tukey post-hoc test was used. There was a main effect of set number on maximum number of repetitions (p < 0.05) (1 > 2, 3, and 4; 2 > 3 and 4; 3 > 4). Mean and peak power in both eccentric and concentric phases also differed across sets (1 > 2, 3, and 4; 2 > 4). There was also a main effect for the recovery type, with lower values (p < 0.05) observed for the active recovery compared to the passive one. It can be concluded that active recovery resulted in lower lactate concentration, but did not improve power performance in the bench press exercise. PMID:25031684

  18. 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,…

  19. Mecillinam resistance in Escherichia coli is conferred by loss of a second activity of the AroK protein.

    PubMed Central

    Vinella, D; Gagny, B; Joseleau-Petit, D; D'Ari, R; Cashel, M

    1996-01-01

    Mecillinam, a beta-lactam antibiotic specific to penicillin-binding protein 2 (PBP 2) in Escherichia coli, blocks cell wall elongation and, indirectly, cell division, but its lethality can be overcome by increased levels of ppGpp, the nucleotide effector of the stringent response. We have subjected an E. coli K-12 strain to random insertional mutagenesis with a mini-Tn10 element. One insertion, which was found to confer resistance to mecillinam in relA+ and relA strains, was mapped at 75.5 min on the E. coli map and was located between the promoters and the coding sequence of the aroK gene, which codes for shikimate kinase 1, one of two E. coli shikimate kinases, both of which are involved in aromatic amino acid biosynthesis. The mecillinam resistance conferred by the insertion was abolished in a delta relA delta spoT strain completely lacking ppGpp, and it thus depends on the presence of ppGpp. Furthermore, the insertion increased the ppGpp pool approximately twofold in a relA+ strain. However, this increase was not observed in relA strains, although the insertion still conferred mecillinam resistance in these backgrounds, showing that mecillinam resistance is not due to an increased ppGpp pool. The resistance was also abolished in an ftsZ84(Ts) strain under semipermissive conditions, and the aroK::mini-Tn10 allele partially suppressed ftsZ84(Ts); however, it did not increase the concentration of the FtsZ cell division protein. The insertion greatly decreased or abolished the shikimate kinase activity of AroK in vivo and in vitro. The two shikimate kinases of E. coli are not equivalent; the loss of AroK confers mecillinam resistance, whereas the loss of Arol, does not. Furthermore, the ability of the aroK mutation to confer mecillinam resistance is shown to be independent of polar effects on operon expression and of effects on the availability of aromatic amino acids or shikimic acid. Instead, we conclude that the AroK protein has a second activity, possibly

  20. Patterns and loss of sexual activity in the year following hospitalization for acute myocardial infarction (a United States National Multisite Observational Study).

    PubMed

    Lindau, Stacy Tessler; Abramsohn, Emily; Gosch, Kensey; Wroblewski, Kristen; Spatz, Erica S; Chan, Paul S; Spertus, John; Krumholz, Harlan M

    2012-05-15

    A multisite observational study of sexual activity-related outcomes in patients enrolled in the TRIUMPH registry during hospitalization for an acute myocardial infarction (AMI) was conducted to identify patterns and loss of sexual activity 1 year after hospitalization for AMI. Gender-specific multivariable hierarchical models were used to identify correlates of loss of sexual activity including physician counseling. Main outcome measurements included "loss of sexual activity" (less frequent or no sexual activity 1 year after an AMI in those who were sexually active in the year before the AMI) and 1-year mortality. Mean ages were 61.1 years for women (n = 605) and 58.6 years for men (n = 1,274). Many were sexually active in the year before and 1 year after hospitalization (44% and 40% of women, 74% and 68% of men, respectively). One third of women and 47% of men reported receiving hospital discharge instructions about resuming sex. Those who did not receive instructions were more likely to report loss of sexual activity (women, adjusted relative risk 1.44, 95% confidence interval 1.16 to 1.79; men, adjusted relative risk 1.27, 95% confidence interval 1.11 to 1.46). One year mortality after AMI was similar in those who reported sexual activity in the first month after AMI (2.1%) and those who were sexually inactive (4.1%, p = 0.08). In conclusion, although many patients were sexually active before AMI, only a minority received discharge counseling about resuming sexual activity. Lack of counseling was associated with loss of sexual activity 1 year later. Mortality was not significantly increased in patients who were sexually active soon after their AMI.

  1. 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.

  2. An Embryonic Myosin Isoform Enables Stretch Activation and Cyclical Power in Drosophila Jump Muscle

    PubMed Central

    Zhao, Cuiping; Swank, Douglas M.

    2013-01-01

    The mechanism behind stretch activation (SA), a mechanical property that increases muscle force and oscillatory power generation, is not known. We used Drosophila transgenic techniques and our new muscle preparation, the jump muscle, to determine if myosin heavy chain isoforms influence the magnitude and rate of SA force generation. We found that Drosophila jump muscles show very low SA force and cannot produce positive power under oscillatory conditions at pCa 5.0. However, we transformed the jump muscle to be moderately stretch-activatable by replacing its myosin isoform with an embryonic isoform (EMB). Expressing EMB, jump muscle SA force increased by 163% and it generated net positive power. The rate of SA force development decreased by 58% with EMB expression. Power generation is Pi dependent as >4 mM Pi was required for positive power from EMB. Pi increased EMB SA force, but not wild-type SA force. Our data suggest that when muscle expressing EMB is stretched, EMB is more easily driven backward to a weakly bound state than wild-type jump muscle. This increases the number of myosin heads available to rapidly bind to actin and contribute to SA force generation. We conclude that myosin heavy chain isoforms influence both SA kinetics and SA force, which can determine if a muscle is capable of generating oscillatory power at a fixed calcium concentration. PMID:23790374

  3. An activating Pik3ca mutation coupled with Pten loss is sufficient to initiate ovarian tumorigenesis in mice

    PubMed Central

    Kinross, Kathryn M.; Montgomery, Karen G.; Kleinschmidt, Margarete; Waring, Paul; Ivetac, Ivan; Tikoo, Anjali; Saad, Mirette; Hare, Lauren; Roh, Vincent; Mantamadiotis, Theo; Sheppard, Karen E.; Ryland, Georgina L.; Campbell, Ian G.; Gorringe, Kylie L.; Christensen, James G.; Cullinane, Carleen; Hicks, Rodney J.; Pearson, Richard B.; Johnstone, Ricky W.; McArthur, Grant A.; Phillips, Wayne A.

    2012-01-01

    Mutations in the gene encoding the p110α subunit of PI3K (PIK3CA) that result in enhanced PI3K activity are frequently observed in human cancers. To better understand the role of mutant PIK3CA in the initiation or progression of tumorigenesis, we generated mice in which a PIK3CA mutation commonly detected in human cancers (the H1047R mutation) could be conditionally knocked into the endogenous Pik3ca locus. Activation of this mutation in the mouse ovary revealed that alone, Pik3caH1047R induced premalignant hyperplasia of the ovarian surface epithelium but no tumors. Concomitantly, we analyzed several human ovarian cancers and found PIK3CA mutations coexistent with KRAS and/or PTEN mutations, raising the possibility that a secondary defect in a co-regulator of PI3K activity may be required for mutant PIK3CA to promote transformation. Consistent with this notion, we found that Pik3caH1047R mutation plus Pten deletion in the mouse ovary led to the development of ovarian serous adenocarcinomas and granulosa cell tumors. Both mutational events were required for early, robust Akt activation. Pharmacological inhibition of PI3K/mTOR in these mice delayed tumor growth and prolonged survival. These results demonstrate that the Pik3caH1047R mutation with loss of Pten is enough to promote ovarian cell transformation and that we have developed a model system for studying possible therapies. PMID:22214849

  4. Computational Fluid Dynamics Simulation Study of Active Power Control in Wind Plants

    SciTech Connect

    Fleming, Paul; Aho, Jake; Gebraad, Pieter; Pao, Lucy; Zhang, Yingchen

    2016-08-01

    This paper presents an analysis performed on a wind plant's ability to provide active power control services using a high-fidelity computational fluid dynamics-based wind plant simulator. This approach allows examination of the impact on wind turbine wake interactions within a wind plant on performance of the wind plant controller. The paper investigates several control methods for improving performance in waked conditions. One method uses wind plant wake controls, an active field of research in which wind turbine control systems are coordinated to account for their wakes, to improve the overall performance. Results demonstrate the challenge of providing active power control in waked conditions but also the potential methods for improving this performance.

  5. Impact of a novel spray-chilling system on surface microflora, water activity and weight loss during beef carcass chilling.

    PubMed

    Kinsella, K J; Sheridan, J J; Rowe, T A; Butler, F; Delgado, A; Quispe-Ramirez, A; Blair, I S; McDowell, D A

    2006-08-01

    Commercially slaughtered and dressed beef carcass sides (n=30) were followed through a standard commercial chill unit fitted with a new "Jasca" air humidification system adjusted to provide intermittent water spraying of carcass sides (spray cycle 2 min on, 1 min off) for 15 h. Immediately after dressing, and after 24h in the chill unit, the surface water activity, and the weight of each side was measured, and 5 cm2 samples were recovered from four locations, i.e. rump, flank, brisket and neck on the surface of each side. These samples, and similar samples from control sides (n=30) processed in a standard commercial chill unit, were subjected to microbiological examination by direct and resuscitation counts on plate count agar (PCA), MacConkey agar (MAC) and violet red bile glucose agar (VRBGA). No significant differences were observed between bacterial numbers on test and control samples on each of the above agars, at each sample point/occasion. Comparison of direct and resuscitation counts suggested the presence of substantial numbers of injured cells, at both stages (pre- and post-chill), on test and control sides. After 24 h in chill units, test sides exhibited an average weight loss of 1.36% (+/-0.36%), which is significantly less (P<0.001) than the average weight loss (1.55%+/-0.24%) from control sides. These results suggest that the Jasca spray-chilling system can limit carcass shrinkage (on average by 0.19%) without significantly increasing the surface populations of selected bacterial groups.

  6. A Test of Social Cognitive Theory to Explain Men's Physical Activity During a Gender-Tailored Weight Loss Program.

    PubMed

    Young, Myles D; Plotnikoff, Ronald C; Collins, Clare E; Callister, Robin; Morgan, Philip J

    2016-11-01

    Physical inactivity is a leading contributor to the burden of disease in men. Social-cognitive theories may improve physical activity (PA) interventions by identifying which variables to target to maximize intervention impact. This study tested the utility of Bandura's social cognitive theory (SCT) to explain men's PA during a 3-month weight loss program. Participants were 204 overweight/obese men (M [SD] age = 46.6 [11.3] years; body mass index = 33.1 [3.5] kg/m(2)). A longitudinal, latent variable structural equation model tested the associations between SCT constructs (i.e., self-efficacy, outcome expectations, intention, and social support) and self-reported moderate-to-vigorous PA (MVPA) and examined the total PA variance explained by SCT. After controlling for Time 1 cognitions and behavior, the model fit the data well (χ(2) = 73.9, degrees of freedom = 39, p < .001; normed χ(2) = 1.9; comparative fit index = 0.96; standardized root mean residual = 0.059) and explained 65% of the variance in MVPA at Time 2. At Time 2, self-efficacy demonstrated the largest direct and total effects on MVPA (βdirect = .45, p < .001; βtotal = .67, p = .002). A small-to-medium effect was observed from intention to MVPA, but not from outcome expectations or social support. This study provides some evidence supporting the tenets of SCT when examining PA behavior in overweight and obese men. Future PA and weight loss interventions for men may benefit by targeting self-efficacy and intention, but the utility of targeting social support and outcome expectations requires further examination.

  7. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... activities in nuclear power reactors against radiological sabotage. 73.55 Section 73.55 Energy NUCLEAR... power reactors against radiological sabotage. (a) Introduction. (1) By March 31, 2010, each nuclear... this section as applicable to operating nuclear power reactor facilities. (6) Applicants for...

  8. 10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... activities in nuclear power reactors against radiological sabotage. 73.55 Section 73.55 Energy NUCLEAR... power reactors against radiological sabotage. (a) Introduction. (1) By March 31, 2010, each nuclear... this section as applicable to operating nuclear power reactor facilities. (6) Applicants for...

  9. Neural activation during anticipated peer evaluation and laboratory meal intake in overweight girls with and without loss of control eating.

    PubMed

    Jarcho, Johanna M; Tanofsky-Kraff, Marian; Nelson, Eric E; Engel, Scott G; Vannucci, Anna; Field, Sara E; Romer, Adrienne L; Hannallah, Louise; Brady, Sheila M; Demidowich, Andrew P; Shomaker, Lauren B; Courville, Amber B; Pine, Daniel S; Yanovski, Jack A

    2015-03-01

    The interpersonal model of loss of control (LOC) eating proposes that socially distressing situations lead to anxious states that trigger excessive food consumption. Self-reports support these links, but the neurobiological underpinnings of these relationships remain unclear. We therefore examined brain regions associated with anxiety in relation to LOC eating and energy intake in the laboratory. Twenty-two overweight and obese (BMIz: 1.9±0.4) adolescent (15.8±1.6y) girls with LOC eating (LOC+, n=10) and without LOC eating (LOC-, n=12) underwent functional magnetic resonance imaging (fMRI) during a simulated peer interaction chatroom paradigm. Immediately after the fMRI scan, girls consumed lunch ad libitum from a 10,934-kcal laboratory buffet meal with the instruction to "let yourself go and eat as much as you want." Pre-specified hypotheses regarding activation of five regions of interest were tested. Analysis of fMRI data revealed a significant group by peer feedback interaction in the ventromedial prefrontal cortex (vmPFC), such that LOC+ had less activity following peer rejection (vs. acceptance), while LOC- had increased activity (p<.005). Moreover, functional coupling between vmPFC and striatum for peer rejection (vs. acceptance) interacted with LOC status: coupling was positive for LOC+, but negative in LOC- (p<.005). Activity of fusiform face area (FFA) during negative peer feedback from high-value peers also interacted with LOC status (p<.005). A positive association between FFA activation and intake during the meal was observed among only those with LOC eating. In conclusion, overweight and obese girls with LOC eating may be distinguished by a failure to engage regions of prefrontal cortex implicated in emotion regulation in response to social distress. The relationship between FFA activation and food intake supports the notion that heightened sensitivity to incoming interpersonal cues and perturbations in socio-emotional neural circuits may lead to

  10. Loss of a neural AMP-activated kinase mimics the effects of elevated serotonin on fat, movement, and hormonal secretions.

    PubMed

    Cunningham, Katherine A; Bouagnon, Aude D; Barros, Alexandre G; Lin, Lin; Malard, Leandro; Romano-Silva, Marco Aurélio; Ashrafi, Kaveh

    2014-06-01

    AMP-activated protein kinase (AMPK) is an evolutionarily conserved master regulator of metabolism and a therapeutic target in type 2 diabetes. As an energy sensor, AMPK activity is responsive to both metabolic inputs, for instance the ratio of AMP to ATP, and numerous hormonal cues. As in mammals, each of two genes, aak-1 and aak-2, encode for the catalytic subunit of AMPK in C. elegans. Here we show that in C. elegans loss of aak-2 mimics the effects of elevated serotonin signaling on fat reduction, slowed movement, and promoting exit from dauer arrest. Reconstitution of aak-2 in only the nervous system restored wild type fat levels and movement rate to aak-2 mutants and reconstitution in only the ASI neurons was sufficient to significantly restore dauer maintenance to the mutant animals. As in elevated serotonin signaling, inactivation of AAK-2 in the ASI neurons caused enhanced secretion of dense core vesicles from these neurons. The ASI neurons are the site of production of the DAF-7 TGF-β ligand and the DAF-28 insulin, both of which are secreted by dense core vesicles and play critical roles in whether animals stay in dauer or undergo reproductive development. These findings show that elevated levels of serotonin promote enhanced secretions of systemic regulators of pro-growth and differentiation pathways through inactivation of AAK-2. As such, AMPK is not only a recipient of hormonal signals but can also be an upstream regulator. Our data suggest that some of the physiological phenotypes previously attributed to peripheral AAK-2 activity on metabolic targets may instead be due to the role of this kinase in neural serotonin signaling.

  11. Development of Real Time Implementation of 5/5 Rule based Fuzzy Logic Controller Shunt Active Power Filter for Power Quality Improvement

    NASA Astrophysics Data System (ADS)

    Puhan, Pratap Sekhar; Ray, Pravat Kumar; Panda, Gayadhar

    2016-12-01

    This paper presents the effectiveness of 5/5 Fuzzy rule implementation in Fuzzy Logic Controller conjunction with indirect control technique to enhance the power quality in single phase system, An indirect current controller in conjunction with Fuzzy Logic Controller is applied to the proposed shunt active power filter to estimate the peak reference current and capacitor voltage. Current Controller based pulse width modulation (CCPWM) is used to generate the switching signals of voltage source inverter. Various simulation results are presented to verify the good behaviour of the Shunt active Power Filter (SAPF) with proposed two levels Hysteresis Current Controller (HCC). For verification of Shunt Active Power Filter in real time, the proposed control algorithm has been implemented in laboratory developed setup in dSPACE platform.

  12. A Study on the Active Induction Control of Upstream Wind Turbines for total power increases

    NASA Astrophysics Data System (ADS)

    Kim, Hyungyu; Kim, Kwansoo; Paek, Insu; Bottasso, Carlo L.; Campagnolo, Filippo

    2016-09-01

    In this study, the effect of active induction control of upstream wind turbines is investigated. Two scaled wind turbines having a rotor diameter of 1 m with a spacing of four times of the rotor diameter were used to experimentally validate the concept. Also, an in-house c code was used to simulate the same two wind turbines and see if the experimental observations can be obtained. From the experiment, approximately 0.81% increase of total power could be observed. Although the simulation results were not exactly the same as the experimental results but the shape was similar and the maximum power increase of 0.27% was predicted. Also from further simulation using NREL 5MW wind turbines instead of scaled wind turbines with realistic ambient turbulence intensity, it was found that the power increase could become more than 1%.

  13. 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.

  14. 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.

  15. Graphene as conductive additives in binderless activated carbon electrodes for power enhancement of supercapacitor

    NASA Astrophysics Data System (ADS)

    Nor, N. S. M.; Deraman, M.; Suleman, M.; Norizam, M. D. M.; Basri, N. H.; Sazali, N. E. S.; Hamdan, E.; Hanappi, M. F. Y. M.; Tajuddin, N. S. M.; Othman, M. A. R.; Shamsudin, S. A.; Omar, R.

    2016-11-01

    Carbon based supercapacitor electrodes from composite of binderless activated carbon and graphene as a conductive additive were fabricated with various amount of graphene (0, 2, 4, 6, 8 and 10 wt%). Graphene was mixed in self-adhesive carbon grains produced from pre-carbonized powder derived from fibers of oil palm empty fruit bunches and converted into green monoliths (GMs). The GMs were carbonized (N2) and activated (CO2) to produce activated carbon monoliths (ACMs) electrodes. Porosity characterizations by nitrogen adsorption-desorption isotherm method shows that the pore characteristics of the ACMs are influenced by the graphene additive. The results of galvanostatic charge-discharge tests carried out on the supercapacitor cells fabricated using these electrodes shows that the addition of graphene additive (even in small amount) decreases the equivalent series resistance and enhances the specific power of the cells but significantly lowers the specific capacitance. The supercapacitor cell constructed with the electrode containing 4 wt % of graphene offers the maximum power (175 W kg-1) which corresponds to an improvement of 55%. These results demonstrate that the addition of graphene as conductive additive in activated carbon electrodes can enhance the specific power of the supercapacitor.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Power output in vertical jumps: does optimum loading depend on activity profiles?

    PubMed

    Pazin, Nemanja; Berjan, Bobana; Nedeljkovic, Aleksandar; Markovic, Goran; Jaric, Slobodan

    2013-03-01

    The previously proposed maximum dynamic output hypothesis (MDO: i.e. the optimum load for maximizing the power output during jumping is one's own body) was tested on individuals of various activity profiles. Forty males (10 strength-trained athletes, 10 speed-trained athletes, 10 physically active non-athletes, and 10 sedentary individuals) performed different vertical jumps on a force plate while a pulley system was used to either reduce or increase the subject's body weight by 10-30 %. As expected, an increase in external loading resulted in a significant increase (p < 0.001) in force output and a concomitant decrease of peak jumping velocity in all groups of participants. The main finding, however, was that all groups revealed the maximum peak and mean power output at approximately the subjects' own body weight although their weight represented prominently different percentage of their maximum dynamic strength. While a significant (p < 0.05), albeit moderate, 'group × load' interaction in one jump was observed for the peak power output, the individual optimum load for maximizing the power output number did not differ among the groups. Although apparently further research on various types of movements is needed, the present results provide, so far, the strongest support of the MDO hypothesis.

  1. α Power, α asymmetry and anterior cingulate cortex activity in depressed males and females.

    PubMed

    Jaworska, Natalia; Blier, Pierre; Fusee, Wendy; Knott, Verner

    2012-11-01

    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 (alpha(2)-indexed). They also exhibited increased sgACC theta(2) 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.

  2. 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.

  3. Loss of VHL promotes progerin expression, leading to impaired p14/ARF function and suppression of p53 activity

    PubMed Central

    Jung, Youn-Sang; Lee, Su-Jin; Lee, Sun-Hye; Chung, Ji-Yun; Jung, Youn Jin; Hwang, Sang Hyun; Ha, Nam-Chul; Park, Bum-Joon

    2013-01-01

    Renal cell carcinomas (RCCs) are frequently occurring genitourinary malignancies in the aged population. A morphological characteristic of RCCs is an irregular nuclear shape, which is used to index cancer grades. Other features of RCCs include the genetic inactivation of the von Hippel-Lindau gene, VHL, and p53 genetic-independent inactivation. An aberrant nuclear shape or p53 suppression has not yet been demonstrated. We examined the effect of progerin (an altered splicing product of the LMNA gene linked to Hutchinson Gilford progeria syndrome; HGPS) on the nuclear deformation of RCCs in comparison to that of HGPS cells. In this study, we showed that progerin was suppressed by pVHL and was responsible for nuclear irregularities as well as p53 inactivation. Thus, progerin suppression can ameliorate nuclear abnormalities and reactivate p53 in response to genotoxic addition. Furthermore, we found that progerin was a target of pVHL E3 ligase and suppressed p53 activity by p14/ARF inhibition. Our findings indicate that the elevated expression of progerin in RCCs results from the loss of pVHL and leads to p53 inactivation through p14/ARF suppression. Interestingly, we showed that progerin was expressed in human leukemia and primary cell lines, raising the possibility that the expression of this LMNA variant may be a common event in age-related cancer progression. PMID:24067370

  4. Activation of the prostaglandin system in response to sleep loss in healthy humans: Potential mediator of increased spontaneous pain

    PubMed Central

    Haack, Monika; Lee, Erin; Cohen, Daniel; Mullington, Janet M.

    2009-01-01

    Insufficient duration of sleep is a highly prevalent behavioral pattern in society that has been shown to cause an increase in spontaneous pain and sensitivity to noxious stimuli. Prostaglandins (PG), in particular PGE2, are key mediators of inflammation and pain, and we investigated whether PGE2 is a potential mediator in sleep-loss induced changes in nociceptive processing. Twenty-four participants (7 females, age 35. 17.1yrs) stayed for 7 days in the Clinical Research Center. After two baseline days, participants were randomly assigned to either three days of 88 hours of total sleep deprivation (TSD, N=15) or 8 hours of sleep per night (N=9), followed by a night of recovery sleep. Participants rated the intensity of various pain-related symptoms every two hours across waking periods on computerized visual analog scales. PGE2 was measured in 24h-urine collections during baseline and third sleep deprivation day. Spontaneous pain, including headache, muscle pain, stomach pain, generalized body pain, and physical discomfort significantly increased by 5 to 14 units on a 100-unit scale during TSD, compared to the sleep condition. Urinary PGE2 metabolite significantly increased by about 30% in TSD over sleep condition. TSD-induced increase in spontaneous pain, in particular headache and muscle pain, was significantly correlated with increase in PGE2 metabolite. Activation of the PGE2 system appears to be a potential mediator of increased spontaneous pain in response to insufficient sleep. PMID:19560866

  5. Loss of TET2 in hematopoietic cells leads to DNA hypermethylation of active enhancers and induction of leukemogenesis

    PubMed Central

    Rasmussen, Kasper D.; Jia, Guangshuai; Johansen, Jens V.; Pedersen, Marianne T.; Rapin, Nicolas; Bagger, Frederik O.; Porse, Bo T.; Bernard, Olivier A.; Christensen, Jesper

    2015-01-01

    DNA methylation is tightly regulated throughout mammalian development, and altered DNA methylation patterns are a general hallmark of cancer. The methylcytosine dioxygenase TET2 is frequently mutated in hematological disorders, including acute myeloid leukemia (AML), and has been suggested to protect CG dinucleotide (CpG) islands and promoters from aberrant DNA methylation. In this study, we present a novel Tet2-dependent leukemia mouse model that closely recapitulates gene expression profiles and hallmarks of human AML1-ETO-induced AML. Using this model, we show that the primary effect of Tet2 loss in preleukemic hematopoietic cells is progressive and widespread DNA hypermethylation affecting up to 25% of active enhancer elements. In contrast, CpG island and promoter methylation does not change in a Tet2-dependent manner but increases relative to population doublings. We confirmed this specific enhancer hypermethylation phenotype in human AML patients with TET2 mutations. Analysis of immediate gene expression changes reveals rapid deregulation of a large number of genes implicated in tumorigenesis, including many down-regulated tumor suppressor genes. Hence, we propose that TET2 prevents leukemic transformation by protecting enhancers from aberrant DNA methylation and that it is the combined silencing of several tumor suppressor genes in TET2 mutated hematopoietic cells that contributes to increased stem cell proliferation and leukemogenesis. PMID:25886910

  6. Loss of Androgen-Regulated MicroRNA 1 Activates SRC and Promotes Prostate Cancer Bone Metastasis

    PubMed Central

    Barrett, Ben; Sheppard-Tillman, Heather; Li, Dongmei; Casey, Orla M.; Fang, Lei; Hynes, Paul G.; Ameri, Amir H.

    2015-01-01

    Bone metastasis is the hallmark of progressive and castration-resistant prostate cancers. MicroRNA 1 (miR-1) levels are decreased in clinical samples of primary prostate cancer and further reduced in metastases. SRC has been implicated as a critical factor in bone metastasis, and here we show that SRC is a direct target of miR-1. In prostate cancer patient samples, miR-1 levels are inversely correlated with SRC expression and a SRC-dependent gene signature. Ectopic miR-1 expression inhibited extracellular signal-regulated kinase (ERK) signaling and bone metastasis in a xenograft model. In contrast, SRC overexpression was sufficient to reconstitute bone metastasis and ERK signaling in cells expressing high levels of miR-1. Androgen receptor (AR) activity, defined by an AR output signature, is low in a portion of castration-resistant prostate cancer. We show that AR binds to the miR-1-2 regulatory region and regulates miR-1 transcription. Patients with low miR-1 levels displayed correlated low canonical AR gene signatures. Our data support the existence of an AR–miR-1–SRC regulatory network. We propose that loss of miR-1 is one mechanistic link between low canonical AR output and SRC-promoted metastatic phenotypes. PMID:25802280

  7. 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

    ... transmission planning activities of the Southwest Power Pool, Inc. (SPP): Strategic Planning Committee Task... Independent Transmission System Operator, Inc. Docket No. ER11-3967-002, Southwest Power Pool, Inc. Docket No... Energy Regulatory Commission Meeting Related to the Transmission Planning Activities of the...

  8. Isolation and Analysis of Novel Electrochemically Active Bacteria for Enhanced Power Generation in Microbial Fuel Cells

    DTIC Science & Technology

    2009-03-07

    ISOLATION AND ANALYSIS OF NOVEL ELECTROCHEMICALLY ACTIVE BACTERIA FOR ENHANCED POWER GENERATION IN MICROBIAL FUEL CELLS B.E. Logan, J.M. Regan...new exoelectrogenic bacteria during this project. We isolated Rhodopseudomonas palustris DX-1, and demonstrated for the first time that a pure culture... isolated Ochrobactrum anthropi YZ-1, which had the remarkable characteristic that it was unable to respire using hydrous Fe(lll) oxide but produced

  9. PI and fuzzy logic controllers for shunt Active Power Filter--a report.

    PubMed

    Karuppanan, P; Mahapatra, Kamala Kanta

    2012-09-01

    The authors acknowledge certain errors in their recently published paper titled "PI and fuzzy logic controllers for shunt active power filter--A report.The ambiguity in band width calculation of adaptive hysteresis controller and control aspects of dc-link voltage issues are addressed. The shunt APF system is validated through extensive simulation and the results are support features of the proposed technique.

  10. Impact of genetic strain on body fat loss, food consumption, metabolism, ventilation, and motor activity in free running female rats.

    PubMed

    Gordon, C J; Phillips, P M; Johnstone, A F M

    2016-01-01

    Chronic exercise is considered as one of the most effective means of countering symptoms of the metabolic syndrome (MS) such as obesity and hyperglycemia. Rodent models of forced or voluntary exercise are often used to study the mechanisms of MS and type 2 diabetes. However, there is little known on the impact of genetic strain on the metabolic response to exercise. We studied the effects of housing rats with running wheels (RW) for 65 days compared to sedentary (SED) housing in five female rat strains: Sprague-Dawley (SD), Long-Evans (LE), Wistar (WIS), spontaneously hypertensive (SHR), and Wistar-Kyoto (WKY). Key parameters measured were total distance run, body composition, food consumption, motor activity, ventilatory responses by plethysmography, and resting metabolic rate (MR). WKY and SHR ran significantly more than the WIS, LE, and SD strains. Running-induced reduction in body fat was affected by strain but not by distance run. LE's lost 6% fat after 21 d of running whereas WKY's lost 2% fat but ran 40% more than LE's. LE and WIS lost body weight while the SHR and WKY strains gained weight during running. Food intake with RW was markedly increased in SHR, WIS, and WKY while LE and SD showed modest increases. Exploratory motor activity was reduced sharply by RW in all but the SD strain. Ventilatory parameters were primarily altered by RW in the SHR, WKY, and WIS strains. MR was unaffected by RW. In an overall ranking of physiological and behavioral responses to RW, the SD strain was considered the least responsive whereas the WIS was scored as most responsive. In terms of RW-induced fat loss, the LE strain appears to be the most ideal. These results should be useful in the future selection of rat models to study benefits of volitional exercise.

  11. Planning a Preliminary program for Earthquake Loss Estimation and Emergency Operation by Three-dimensional Structural Model of Active Faults

    NASA Astrophysics Data System (ADS)

    Ke, M. C.

    2015-12-01

    Large scale earthquakes often cause serious economic losses and a lot of deaths. Because the seismic magnitude, the occurring time and the occurring location of earthquakes are still unable to predict now. The pre-disaster risk modeling and post-disaster operation are really important works of reducing earthquake damages. In order to understanding disaster risk of earthquakes, people usually use the technology of Earthquake simulation to build the earthquake scenarios. Therefore, Point source, fault line source and fault plane source are the models which often are used as a seismic source of scenarios. The assessment results made from different models used on risk assessment and emergency operation of earthquakes are well, but the accuracy of the assessment results could still be upgrade. This program invites experts and scholars from Taiwan University, National Central University, and National Cheng Kung University, and tries using historical records of earthquakes, geological data and geophysical data to build underground three-dimensional structure planes of active faults. It is a purpose to replace projection fault planes by underground fault planes as similar true. The analysis accuracy of earthquake prevention efforts can be upgraded by this database. Then these three-dimensional data will be applied to different stages of disaster prevention. For pre-disaster, results of earthquake risk analysis obtained by the three-dimensional data of the fault plane are closer to real damage. For disaster, three-dimensional data of the fault plane can be help to speculate that aftershocks distributed and serious damage area. The program has been used 14 geological profiles to build the three dimensional data of Hsinchu fault and HisnCheng faults in 2015. Other active faults will be completed in 2018 and be actually applied on earthquake disaster prevention.

  12. Muscular power, neuromuscular activation, and performance in shot put athletes at preseason and at competition period.

    PubMed

    Kyriazis, Thomas A; Terzis, Gerasimos; Boudolos, Konstantinos; Georgiadis, Georgios

    2009-09-01

    The aim of this study was to investigate changes in shot put performance, muscular power, and neuromuscular activation of the lower extremities, between the preseason and the competition period, in skilled shot put athletes using the rotational technique. Shot put performance was assessed at the start of the pre-season period as well as after 12 weeks, at the competition period, in nine shot putters. Electromyographic (EMG) activity of the right vastus lateralis muscle was recorded during all shot put trials. Maximum squat strength (1RM) and mechanical parameters during the countermovement jump (CMJ) on a force platform were also determined at pre-season and at competition period. Shot put performance increased 4.7% (p < 0.05), while 1RM squat increased 6.5% (p < 0.025). EMG activity during the delivery phase was increased significantly (p < 0.025) after the training period. Shot put performance was significantly related with muscular power and takeoff velocity during the CMJ, at competition period (r = 0.66, p < 0.05 and 0.70, p < 0.05), but not with maximum vertical force. One RM squat was not related significantly with shot put performance. These results suggest that muscular power of the lower extremities is a better predictor of rotational shot put performance than absolute muscular strength in skilled athletes, at least during the competition period.

  13. An Adaptive Reconfigurable Active Voltage Doubler/Rectifier for Extended-Range Inductive Power Transmission

    PubMed Central

    Lee, Hyung-Min; Ghovanloo, Maysam

    2014-01-01

    We present an adaptive reconfigurable active voltage doubler (VD)/rectifier (REC) (VD/REC) in standard CMOS, which can adaptively change its topology to either a VD or a REC by sensing the output voltage, leading to more robust inductive power transmission over an extended range. Both active VD and REC modes provide much lower dropout voltage and far better power conversion efficiency (PCE) compared to their passive counterparts by adopting offset-controlled high-speed comparators that drive the rectifying switches at proper times in the high-frequency band. We have fabricated the active VD/REC in a 0.5-µm 3-metal 2-poly CMOS process, occupying 0.585 mm2 of chip area. In an exemplar setup, VD/REC extended the power transmission range by 33% (from 6 to 8 cm) in relative coil distance and 41.5% (from 53° to 75°) in relative coil orientation compared to using the REC alone. While providing 3.1-V dc output across a 500-Ω load from 2.15- (VD) and 3.7-V (REC) peak ac inputs at 13.56 MHz, VD/REC achieved measured PCEs of 70% and 77%, respectively. PMID:24633369

  14. Loss of Sparc in p53-null Astrocytes Promotes Macrophage Activation and Phagocytosis Resulting in Decreased Tumor Size and Tumor Cell Survival.

    PubMed

    Thomas, Stacey L; Schultz, Chad R; Mouzon, Ezekiell; Golembieski, William A; El Naili, Reima; Radakrishnan, Archanna; Lemke, Nancy; Poisson, Laila M; Gutiérrez, Jorge A; Cottingham, Sandra; Rempel, Sandra A

    2015-07-01

    Both the induction of SPARC expression and the loss of the p53 tumor suppressor gene are changes that occur early in glioma development. Both SPARC and p53 regulate glioma cell survival by inverse effects on apoptotic signaling. Therefore, during glioma formation, the upregulation of SPARC may cooperate with the loss of p53 to enhance cell survival. This study determined whether the loss of Sparc in astrocytes that are null for p53 would result in reduced cell survival and tumor formation and increased tumor immunogenicity in an in vivo xenograft brain tumor model. In vitro, the loss of Sparc in p53-null astrocytes resulted in an increase in cell proliferation, but a loss of tumorigenicity. At 7 days after intracranial implantation, Sparc-null tumors had decreased tumor cell survival, proliferation and reduced tumor size. The loss of Sparc promoted microglia/macrophage activation and phagocytosis of tumor cells. Our results indicate that the loss of p53 by deletion/mutation in the early stages of glioma formation may cooperate with the induction of SPARC to potentiate cancer cell survival and escape from immune surveillance.

  15. Electrostatic power generation using carbon-activated cotton thread on textile

    NASA Astrophysics Data System (ADS)

    Kim, Baek Hyun; Barnhart, Be