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Sample records for active core fluctuations

  1. Fluctuation BES measurements with the ITER core CXRS prototype spectrometer

    Pokol, G.I., E-mail: pokol@reak.bme.hu [Institute of Nuclear Techniques, Budapest University of Technology and Economics, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Zoletnik, S.; Dunai, D. [WIGNER RCP, RMKI, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Marchuk, O. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Jülich (Germany); Baross, T. [WIGNER RCP, RMKI, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Erdei, G. [Department of Atomic Physics, Budapest University of Technology and Economics, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Grunda, G.; Kiss, I.G. [WIGNER RCP, RMKI, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Kovacsik, A. [Institute of Nuclear Techniques, Budapest University of Technology and Economics, EURATOM Association, PO Box 91, H-1521, Budapest (Hungary); Hellermann, M. von; Lischtschenko, O. [Dutch-Institute for Fundamental Energy Research, Association EURATOM-FOM, Partner in the Trilateral Euregio Cluster and ITER-NL, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Biel, W. [Institut für Energieforschung – Plasmaphysik, Forschungszentrum Jülich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Jülich (Germany); Jaspers, R.J.E. [Science and Technology of Nuclear Fusion, Eindhoven University of Technology (Netherlands); Durkut, M. [TNO Science and Industry, Partner in ITER-NL, PO Box 155, 2600 AD Delft (Netherlands)

    2013-10-15

    Highlights: • We integrated a fluctuation beam emission measurement into the ITER CXRS prototype spectrometer. • The fluctuation BES measurement provided data at TEXTOR that agree well with the simulation based on the Simulation Of Spectra package. • The same simulation method has been used to evaluate the feasibility of a fluctuation BES measurement on the ITER DNB using the CXRS periscopes. -- Abstract: The ITER core CXRS diagnostic system collects the light emitted from the interaction of the diagnostic neutral beam with the core plasma and guides it via a mirror labyrinth through the upper port plug no. 3 towards a fiber bundle, which then transmits the light into a set of spectrometers for spectral analysis. In order to test the accessibility of the special parameter range required for the ITER measurement, a prototype spectrometer was built and operated successfully at the TEXTOR tokamak. In addition to the He/Be, C/Ne and H/D/T regular spectral channels, a fluctuation beam emission spectroscopy (BES) system has been integrated to measure core MHD activity, and validate corresponding ITER simulation results. The fluctuation system can be operated as an alternative to the spectral BES measurement, and has 8 spatial channels sampled at 2 MHz. In this paper, we present details of the fluctuation BES system and its interface to the ITER prototype spectrometer along with simulation and measurement results at TEXTOR. We show that the measurement fully confirms the simulation results on achievable photon current at the detector and on the signal to noise ratio.

  2. Nonthermal Fluctuations and Mechanics of the Active Cell Nucleus

    Smith, K; Byrd, H; MacKintosh, F C; Kilfoil, M L

    2013-01-01

    We present direct measurements of fluctuations in the nucleus of yeast cells. While prior work has shown these fluctuations to be active and non-thermal in character, their origin and time dependence are not understood. We show that nuclear fluctuations can be quantitatively understood by uncorrelated, active force fluctuations driving a nuclear medium that is dominated by an uncondensed DNA solution, for which we perform rheological measurements on an in vitro model system under similar conditions to what is expected in the nucleus. We conclude that the eukaryotic nucleus of living cells is a nonequilibrium soft material whose fluctuations are actively driven, and are far from thermal in their time dependence.

  3. Motion of Euglena gracilis: Active fluctuations and velocity distribution

    Romanczuk, P.; Romensky, M.; Scholz, D.; Lobaskin, V.; Schimansky-Geier, L.

    2015-07-01

    We study the velocity distribution of unicellular swimming algae Euglena gracilis using optical microscopy and active Brownian particle theory. To characterize a peculiar feature of the experimentally observed distribution at small velocities we use the concept of active fluctuations, which was recently proposed for the description of stochastically self-propelled particles [Romanczuk, P. and Schimansky-Geier, L., Phys. Rev. Lett. 106, 230601 (2011)]. In this concept, the fluctuating forces arise due to internal random performance of the propulsive motor. The fluctuating forces are directed in parallel to the heading direction, in which the propulsion acts. In the theory, we introduce the active motion via the depot model [Schweitzer, et al., Phys. Rev. Lett. 80(23), 5044 (1998)]. We demonstrate that the theoretical predictions based on the depot model with active fluctuations are consistent with the experimentally observed velocity distributions. In addition to the model with additive active noise, we obtain theoretical results for a constant propulsion with multiplicative noise.

  4. Motion of Euglena Gracilis: Active Fluctuations and Velocity Distribution

    Romanczuk, Pawel; Scholz, Dimitri; Lobaskin, Vladimir; Schimansky-Geier, Lutz

    2015-01-01

    We study the velocity distribution of unicellular swimming algae Euglena gracilis using optical microscopy and theory. To characterize a peculiar feature of the experimentally observed distribution at small velocities we use the concept of active fluctuations, which was recently proposed for the description of stochastically self-propelled particles [Romanczuk, P. and Schimansky-Geier, L., Phys. Rev. Lett. 106, 230601 (2011)]. In this concept, the fluctuating forces arise due to internal random performance of the propulsive motor. The fluctuating forces are directed in parallel to the heading direction, in which the propulsion acts. In the theory, we introduce the active motion via the depot model [Schweitzer et al., Phys. Rev. Lett. 80, 23, 5044 (1998)]. We demonstrate that the theoretical predictions based on the depot model with active fluctuations are consistent with the experimentally observed velocity distributions. In addition to the model with additive active noise, we obtain theoretical results for a...

  5. Density Fluctuation Effects on Collective Neutrino Oscillations in O-Ne-Mg Core-Collapse Supernovae

    Cherry, John F; Carlson, Joe; Duan, Huaiyu; Fuller, George M; Qian, Yong-Zhong

    2011-01-01

    We investigate the effect of matter density fluctuations on supernova collective neutrino flavor oscillations. In particular, we use full multi-angle, 3-flavor, self-consistent simulations of the evolution of the neutrino flavor field in the envelope of an O-Ne-Mg core collapse supernova at shock break-out (neutrino neutronization burst) to study the effect of the matter density "bump" left by the He-burning shell. We find a seemingly counterintuitive increase in the overall electron neutrino survival probability created by this matter density feature. We discuss this behavior in terms of the interplay between the matter density profile and neutrino collective effects. While our results give new insights into this interplay, they also suggest an immediate consequence for supernova neutrino burst detection: it will be difficult to use a burst signal to extract information on fossil burning shells or other fluctuations of this scale in the matter density profile. Consistent with previous studies, our results al...

  6. Exploration of the spontaneous fluctuating activity of single enzyme molecules

    Schwabe, A.; Maarleveld, T.R.; Bruggeman, F.J.

    2013-01-01

    Single enzyme molecules display inevitable, stochastic fluctuations in their catalytic activity. In metabolism, for instance, the stochastic activity of individual enzymes is averaged out due to their high copy numbers per single cell. However, many processes inside cells rely on single enzyme activ

  7. Optical fiber sensor having an active core

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1993-01-01

    An optical fiber is provided. The fiber is comprised of an active fiber core which produces waves of light upon excitation. A factor ka is identified and increased until a desired improvement in power efficiency is obtained. The variable a is the radius of the active fiber core and k is defined as 2 pi/lambda wherein lambda is the wavelength of the light produced by the active fiber core. In one embodiment, the factor ka is increased until the power efficiency stabilizes. In addition to a bare fiber core embodiment, a two-stage fluorescent fiber is provided wherein an active cladding surrounds a portion of the active fiber core having an improved ka factor. The power efficiency of the embodiment is further improved by increasing a difference between the respective indices of refraction of the active cladding and the active fiber core.

  8. Identifying the core components of emotional intelligence: evidence from amplitude of low-frequency fluctuations during resting state.

    Weigang Pan

    Full Text Available Emotional intelligence (EI is a multi-faceted construct consisting of our ability to perceive, monitor, regulate and use emotions. Despite much attention being paid to the neural substrates of EI, little is known of the spontaneous brain activity associated with EI during resting state. We used resting-state fMRI to investigate the association between the amplitude of low-frequency fluctuations (ALFFs and EI in a large sample of young, healthy adults. We found that EI was significantly associated with ALFFs in key nodes of two networks: the social emotional processing network (the fusiform gyrus, right superior orbital frontal gyrus, left inferior frontal gyrus and left inferior parietal lobule and the cognitive control network (the bilateral pre-SMA, cerebellum and right precuneus. These findings suggest that the neural correlates of EI involve several brain regions in two crucial networks, which reflect the core components of EI: emotion perception and emotional control.

  9. Non-Gaussian limit fluctuations in active swimmer suspensions

    Kurihara, Takashi; Aridome, Msato; Ayade, Heev; Zaid, Irwin; Mizuno, Daisuke

    2017-03-01

    We investigate the hydrodynamic fluctuations in suspensions of swimming microorganisms (Chlamydomonas) by observing the probe particles dispersed in the media. Short-term fluctuations of probe particles were superdiffusive and displayed heavily tailed non-Gaussian distributions. The analytical theory that explains the observed distribution was derived by summing the power-law-decaying hydrodynamic interactions from spatially distributed field sources (here, swimming microorganisms). The summing procedure, which we refer to as the physical limit operation, is applicable to a variety of physical fluctuations to which the classical central limiting theory does not apply. Extending the analytical formula to compare to experiments in active swimmer suspensions, we show that the non-Gaussian shape of the observed distribution obeys the analytic theory concomitantly with independently determined parameters such as the strength of force generations and the concentration of Chlamydomonas. Time evolution of the distributions collapsed to a single master curve, except for their extreme tails, for which our theory presents a qualitative explanation. Investigations thereof and the complete agreement with theoretical predictions revealed broad applicability of the formula to dispersions of active sources of fluctuations.

  10. Multifractal detrended fluctuation analysis of optogenetic modulation of neural activity

    Kumar, S.; Gu, L.; Ghosh, N.; Mohanty, S. K.

    2013-02-01

    Here, we introduce a computational procedure to examine whether optogenetically activated neuronal firing recordings could be characterized as multifractal series. Optogenetics is emerging as a valuable experimental tool and a promising approach for studying a variety of neurological disorders in animal models. The spiking patterns from cortical region of the brain of optogenetically-stimulated transgenic mice were analyzed using a sophisticated fluctuation analysis method known as multifractal detrended fluctuation analysis (MFDFA). We observed that the optogenetically-stimulated neural firings are consistent with a multifractal process. Further, we used MFDFA to monitor the effect of chemically induced pain (formalin injection) and optogenetic treatment used to relieve the pain. In this case, dramatic changes in parameters characterizing a multifractal series were observed. Both the generalized Hurst exponent and width of singularity spectrum effectively differentiates the neural activities during control and pain induction phases. The quantitative nature of the analysis equips us with better measures to quantify pain. Further, it provided a measure for effectiveness of the optogenetic stimulation in inhibiting pain. MFDFA-analysis of spiking data from other deep regions of the brain also turned out to be multifractal in nature, with subtle differences in the parameters during pain-induction by formalin injection and inhibition by optogenetic stimulation. Characterization of neuronal firing patterns using MFDFA will lead to better understanding of neuronal response to optogenetic activation and overall circuitry involved in the process.

  11. Activation of Selected Core Muscles during Pressing

    Thomas W. Nesser

    2015-10-01

    Full Text Available Introduction: Unstable surface training is often used to activate core musculature during resistance training. Unfortunately, unstable surface training is risky and leads to detraining. Purpose: The purpose of this study was to determine core muscle activation during stable surface ground-based lifts. Methods: Fourteen recreational trained and former NCAA DI athletes (weight 84.2 ± 13.3 kg; height 176.0 ± 9.5 cm; age 20.9 ± 2.0 years volunteered for participation. Subjects completed two ground-based lifts: overhead press and push-press. Surface EMG was recorded from 4 muscles on the right side of the body (Rectus Abdominus (RA, External Oblique (EO, Transverse Abdominus (TA, and Erector Spinae (ES. Results: Paired sample T-tests identified significant muscle activation differences between the overhead press and the push-press included ES and EO. Average and peak EMG for ES was significantly greater in push-press (P<0.01. Anterior displacement of COP was significantly greater in push-press compared to overhead press during the eccentric phase. Conclusion: The push-press was identified as superior in core muscle activation when compared to the overhead pressing exercise. Keywords: torso, stability, weight lifting, resistance training

  12. Progress Toward a Technique for Measuring Electric Field Fluctuations in Tokamak Core Plasmas

    Thompson, D. S.; Bakken, M. R.; Burke, M. G.; Couto, H. P.; Fonck, R. J.; Lewicki, B. T.; Winz, G. R.

    2014-10-01

    Measurements of electric field fluctuations in magnetic confinement experiments are desired for validating turbulence and transport models. A new diagnostic to measure Ez (r , t) fluctuations is in development on the Pegasus Toroidal Experiment. The approach is based on neutral beam emission spectroscopy using a high-throughput, high-resolution spectrometer to resolve fluctuations in wavelength separation between components of the motional Stark effect spectrum. Fluctuations at mid-minor-radius, normalized to an estimated MSE field, are estimated to be δE /EMSE ~ 10-3. In order to resolve fluctuations at turbulent time scales (fNy ~ 500 kHz), beam and spectrometer designs minimize broadening and maximize signal-to-noise ratio. The diagnostic employs a Fabry-Pérot spectrometer with étendue-matched collection optics and low noise detectors. The interferometer spacing is varied across the face of the etalon to mitigate geometric Doppler broadening. An 80 keV H0 beam from PBX-M with a divergence Ω deployment on larger fusion facilities. Work supported by US DOE Grant DE-FG02-89ER53296.

  13. Lithology and chronology of ice-sheet fluctuations (magnetic susceptibility of cores from the western Ross Sea)

    Jennings, Anne E.

    1993-01-01

    The goals of the marine geology part of WAIS include reconstructing the chronology and areal extent of ice-sheet fluctuations and understanding the climatic and oceanographic influences on ice-sheet history. As an initial step toward attaining these goals, down-core volume magnetic susceptibility (MS) logs of piston cores from three N-S transects in the western Ross Sea are compared. The core transects are within separate petrographic provinces based on analyses of till composition. The provinces are thought to reflect the previous locations of ice streams on the shelf during the last glaciation. Magnetic susceptibility is a function of magnetic mineral composition, sediment texture, and sediment density. It is applied in the western Ross Sea for two purposes: (1) to determine whether MS data differentiates the three transects (i.e., flow lines), and thus can be used to make paleodrainage reconstructions of the late Wisconsinan ice sheet; and (2) to determine whether the MS data can aid in distinguishing basal till diamictons from diamictons of glacial-marine origin and thus, aid paleoenvironmental interpretations. A comparison of the combined data of cores in each transect is presented.

  14. Superfluid phase transition with activated velocity fluctuations: Renormalization group approach.

    Dančo, Michal; Hnatič, Michal; Komarova, Marina V; Lučivjanský, Tomáš; Nalimov, Mikhail Yu

    2016-01-01

    A quantum field model that incorporates Bose-condensed systems near their phase transition into a superfluid phase and velocity fluctuations is proposed. The stochastic Navier-Stokes equation is used for a generation of the velocity fluctuations. As such this model generalizes model F of critical dynamics. The field-theoretic action is derived using the Martin-Siggia-Rose formalism and path integral approach. The regime of equilibrium fluctuations is analyzed within the perturbative renormalization group method. The double (ε,δ)-expansion scheme is employed, where ε is a deviation from space dimension 4 and δ describes scaling of velocity fluctuations. The renormalization procedure is performed to the leading order. The main corollary gained from the analysis of the thermal equilibrium regime suggests that one-loop calculations of the presented models are not sufficient to make a definite conclusion about the stability of fixed points. We also show that critical exponents are drastically changed as a result of the turbulent background and critical fluctuations are in fact destroyed by the developed turbulence fluctuations. The scaling exponent of effective viscosity is calculated and agrees with expected value 4/3.

  15. Prediction of the Bandgap of a Core-Shell Microsphere via Light Intensity Fluctuations

    Moon Kyu Choi

    2011-01-01

    Full Text Available It has been experimentally observed that in the case of microspheres irradiated by light, the absorption wavelength shift occurs, known as the blueshift, with changing shell materials (i.e., by decreasing the refractive index of the shell. In the present investigation, we want to demonstrate it numerically by using the boundary element method. The material used for the simulation is a core-shell (SiO2 and another material of a larger refractive index microsphere and it is irradiated by unpolarized monochromatic light wave. This paper intends to demonstrate that it is possible to predict the bandgap of a core-shell microsphere resulting from two different bandgap materials and that the numerical simulation employed produces the blueshift.

  16. Late Holocene vegetation changes in relation with climate fluctuations and human activities in Languedoc (Southern France

    J. Azuara

    2015-09-01

    Full Text Available Holocene climate fluctuations and human activities since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to reconstruct Mediterranean paleoenvironments over the last millennia remains a challenging issue. High resolution pollen analyses were undertaken on two cores from the Palavasian lagoon system (Hérault, southern France. These records allow reconstruction of vegetation dynamics over the last 4500 years. Results are compared with climatic, historical and archeological archives. A long-term aridification trend is highlighted during the Late Holocene and three superimposed arid events are recorded at 4600–4300, 2800–2400 and 1300–1100 cal BP. These periods of climatic instability coincide in time with the rapid climatic events depicted in the Atlantic Ocean (Bond et al., 2001. From the Bronze Age (4000 cal BP to the end of the Iron Age (around 2000 cal BP, the spread of evergreen taxa and loss of forest cover result from anthropogenic impact. The Antiquity is characterized by a major reforestation event related to the concentration of rural activities and populations in coastal plains leading to forest recovery in the mountains. A major regional deforestation occurred at the beginning of the High Middle Ages. Around 1000 cal BP, forest cover is minimal while cover of olive, chestnut and walnut expands in relation to increasing human influence. The present day vegetation dominated by Mediterranean shrubland and pines has been in existence since the beginning of the 20th century.

  17. Marshall N. Rosenbluth Outstanding Doctoral Thesis Award Talk: Simultaneous Measurement of Electron Temperature and Density Fluctuations in the Core of DIII-D Plasmas

    White, A. E.

    2009-11-01

    Multi-field fluctuation measurements provide opportunities for rigorous comparison between experiment and nonlinear gyrokinetic turbulence simulations. A unique set of diagnostics on DIII-D allows for simultaneous study of local, long-wavelength (0 < kθρs< 0.5) electron temperature and density fluctuations in the core plasma (0.4 < ρ< 0.8). Previous experiments in L-mode indicate that normalized electron temperature fluctuation levels (40 < f < 400,kHz) increase with radius from ˜0.4% at ρ= 0.5 to ˜2% at ρ=0.8, similar to simultaneously measured density fluctuations. Electron cyclotron heating (ECH) is used to increase Te, which increases electron temperature fluctuation levels and electron heat transport in the experiments. In contrast, long wavelength density fluctuation levels change very little. The different responses are consistent with increased TEM drive relative to ITG-mode drive. A new capability at DIII-D is the measurement of phase angle between electron temperature and density fluctuations using coupled correlation electron cyclotron emission radiometer and reflectometer diagnostics. Linear and nonlinear GYRO runs have been used to design validation experiments that focus on measurements of the phase angle. GYRO shows that if Te and ∇Te increase 50% in a beam-heated L-mode plasma (ρ=0.5), then the phase angle between electron temperature and density fluctuations decreases 30%-50% and electron temperature fluctuation levels increase a factor of two more than density fluctuations. Comparisons between these predictions and experimental results will be presented.

  18. Systematic review of core muscle activity during physical fitness exercises.

    Martuscello, Jason M; Nuzzo, James L; Ashley, Candi D; Campbell, Bill I; Orriola, John J; Mayer, John M

    2013-06-01

    A consensus has not been reached among strength and conditioning specialists regarding what physical fitness exercises are most effective to stimulate activity of the core muscles. Thus, the purpose of this article was to systematically review the literature on the electromyographic (EMG) activity of 3 core muscles (lumbar multifidus, transverse abdominis, quadratus lumborum) during physical fitness exercises in healthy adults. CINAHL, Cochrane Central Register of Controlled Trials, EMBASE, PubMed, SPORTdiscus, and Web of Science databases were searched for relevant articles using a search strategy designed by the investigators. Seventeen studies enrolling 252 participants met the review's inclusion/exclusion criteria. Physical fitness exercises were partitioned into 5 major types: traditional core, core stability, ball/device, free weight, and noncore free weight. Strength of evidence was assessed and summarized for comparisons among exercise types. The major findings of this review with moderate levels of evidence indicate that lumbar multifidus EMG activity is greater during free weight exercises compared with ball/device exercises and is similar during core stability and ball/device exercises. Transverse abdominis EMG activity is similar during core stability and ball/device exercises. No studies were uncovered for quadratus lumborum EMG activity during physical fitness exercises. The available evidence suggests that strength and conditioning specialists should focus on implementing multijoint free weight exercises, rather than core-specific exercises, to adequately train the core muscles in their athletes and clients.

  19. Mitigation of Wind Power Fluctuation by Active Current Control of Variable Speed Wind Turbines

    Zhang, Yunqian; Chen, Zhe; Hu, Weihao;

    2013-01-01

    Wind shear and tower shadow are the sources of power fluctuation of grid connected wind turbines during continuous operation. This paper presents a simulation model of a MW-level doubly fed induction generator (DFIG) based variable speed wind turbine with a partial-scale back-to-back power...... converter in Simulink. A simple and effective method of wind power fluctuations mitigation by active current control of DFIG is proposed. It smoothes the generator output active power oscillations by adjusting the active current of the DFIG, such that the power oscillation is stored as the kinetic energy...

  20. Opposing Effects of Intrinsic Conductance and Correlated Synaptic Input on V-Fluctuations during Network Activity

    Kolind, Jens; Hounsgaard, Jørn Dybkjær; Berg, Rune W

    2012-01-01

    Neurons often receive massive concurrent bombardment of synaptic inhibition and excitation during functional network activity. This increases membrane conductance and causes fluctuations in membrane potential (V(m)) and spike timing. The conductance increase is commonly attributed to synaptic......(m) -fluctuations and conductance observed experimentally during functional network activity leave little room for intrinsic conductance to contribute. Even without intrinsic conductances the variance in V(m) -fluctuations can only be explained by a high degree of correlated firing among presynaptic neurons....... conductance, but also includes the intrinsic conductances recruited during network activity. These two sources of conductance have contrasting dynamic properties at sub-threshold membrane potentials. Synaptic transmitter gated conductance changes abruptly and briefly with each presynaptic action potential...

  1. Modulation of muscle activity and force fluctuations in the plantarflexors after bedrest depends on knee position.

    Yoshitake, Yasuhide; Kouzaki, Motoki; Fukuoka, Hideoki; Fukunaga, Tetsuo; Shinohara, Minoru

    2007-06-01

    Force fluctuations in leg muscles increase after bedrest, perhaps due to modulation of the neural strategy that is specific to a muscle or common to agonist muscles. The purpose of this study was to examine the modulation of muscle activity and force fluctuations during steady contractions with variable involvement of plantarflexor muscles after bedrest at knee-flexed (FLX) and extended (EXT) positions. Before and after 20-day bedrest, plantarflexion force and surface electromyogram (EMG) in the medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles were measured during steady isometric contractions in five young men. In EXT, power EMG of MG increased significantly after bedrest. This low-frequency modulation of muscle activity in MG accompanied a 29% increase in the standard deviation of force. There was no change in EMG in other muscles. In FLX, there was no adjustment in EMG or force fluctuations. These results suggest that low-frequency modulation of MG plays a role in increasing force fluctuations during steady plantarflexion in EXT after bedrest. The findings indicate task/muscle specificity in the modulation of neural strategy during steady contractions after bedrest and underscore the importance of designing a specific training regimen targeted to particular tasks/muscles with regard to force fluctuations in multiple-agonist systems.

  2. What kind of noise is brain noise? Anomalous scaling behavior of the resting brain activity fluctuations.

    Daniel eFraiman

    2012-07-01

    Full Text Available The study of spontaneous fluctuations of brain activity, often referred as brain noise, is getting increasing attention in functional magnetic resonance imaging (fMRI studies. Despite important efforts, much of the statistical properties of such fluctuations remain largely unknown. This work scrutinize these fluctuations looking at specific statistical properties which are relevant to clarify its dynamical origins. Here, three statistical features which clearly differentiate brain data from naive expectations for random processes are uncovered: First, the variance of the fMRI mean signal as a function of the number of averaged voxels remains constant across a wide range of observed clusters sizes. Second, the anomalous behavior of the variance is originated by bursts of synchronized activity across regions, regardless of their widely different sizes. Finally, the correlation length (i.e., the length at which the correlation strength between two regions vanishes as well as mutual information diverges with the cluster's size considered, such that arbitrarily large clusters exhibit the same collective dynamics than smaller ones. These three properties are known to be exclusive of complex systems exhibiting critical dynamics, where the spatio-temporal dynamics show these peculiar type of fluctuations. Thus, these findings are fully consistent with previous reports of brain critical dynamics, and are relevant for the interpretation of the role of fluctuations and variability in brain function in health and disease.

  3. Integration core exercises elicit greater muscle activation than isolation exercises.

    Gottschall, Jinger S; Mills, Jackie; Hastings, Bryce

    2013-03-01

    The American College of Sports Medicine and the United States Department of Health and Human Services advocate core training as a means to improve stability, reduce injury, and maintain mobility. There are countless exercises that target the primary core trunk muscles (abdominal and lumbar) with the aim of providing these benefits. However, it is unknown as to which exercises elicit the greatest activation thereby maximizing functional gains and peak performance. Thus, our purpose was to determine whether integration core exercises that require activation of the distal trunk muscles (deltoid and gluteal) elicit greater activation of primary trunk muscles in comparison with isolation core exercises that only require activation of the proximal trunk muscles. Twenty participants, 10 men and 10 women, completed 16 randomly assigned exercises (e.g., crunch, upper body extension, and hover variations). We measured muscle activity with surface electromyography of the anterior deltoid, rectus abdominus, external abdominal oblique, lumbar erector spinae, thoracic erector spinae, and gluteus maximus. Our results indicate that the activation of the abdominal and lumbar muscles was the greatest during the exercises that required deltoid and gluteal recruitment. In conclusion, when completing the core strength guidelines, an integrated routine that incorporates the activation of distal trunk musculature would be optimal in terms of maximizing strength, improving endurance, enhancing stability, reducing injury, and maintaining mobility.

  4. Molecular kinetics. Ras activation by SOS: allosteric regulation by altered fluctuation dynamics.

    Iversen, Lars; Tu, Hsiung-Lin; Lin, Wan-Chen; Christensen, Sune M; Abel, Steven M; Iwig, Jeff; Wu, Hung-Jen; Gureasko, Jodi; Rhodes, Christopher; Petit, Rebecca S; Hansen, Scott D; Thill, Peter; Yu, Cheng-Han; Stamou, Dimitrios; Chakraborty, Arup K; Kuriyan, John; Groves, Jay T

    2014-07-01

    Activation of the small guanosine triphosphatase H-Ras by the exchange factor Son of Sevenless (SOS) is an important hub for signal transduction. Multiple layers of regulation, through protein and membrane interactions, govern activity of SOS. We characterized the specific activity of individual SOS molecules catalyzing nucleotide exchange in H-Ras. Single-molecule kinetic traces revealed that SOS samples a broad distribution of turnover rates through stochastic fluctuations between distinct, long-lived (more than 100 seconds), functional states. The expected allosteric activation of SOS by Ras-guanosine triphosphate (GTP) was conspicuously absent in the mean rate. However, fluctuations into highly active states were modulated by Ras-GTP. This reveals a mechanism in which functional output may be determined by the dynamical spectrum of rates sampled by a small number of enzymes, rather than the ensemble average.

  5. Core muscle activation during dynamic upper limb exercises in women.

    Tarnanen, Sami P; Siekkinen, Kirsti M; Häkkinen, Arja H; Mälkiä, Esko A; Kautiainen, Hannu J; Ylinen, Jari J

    2012-12-01

    Although several everyday functions and sporting activities demand controlled use of the abdominal and back muscles while working with the upper limbs, the activity of core muscles during dynamic upper limb exercises in the standing position has not been studied extensively. The purpose of this cross-sectional study was to examine abdominal and back muscle activity during dynamic upper limb exercises while standing and to evaluate whether dynamic exercises are appropriate for strengthening muscles. The activation of the rectus abdominis, obliquus externus abdominis, longissimus, and multifidus muscles during dynamic bilateral or unilateral shoulder exercises with or without fixation of the pelvis was measured in 20 healthy women using surface electromyography. Trunk muscle activation during isometric maximum contraction was used as a comparative reference. With bilateral shoulder extension and unilateral shoulder horizontal adduction, abdominal muscle activity was >60% of activity during reference exercises. With unilateral shoulder horizontal abduction and shoulder extension exercises, back muscle activity was >60% of the activity level reference exercise. Muscle activation levels were 35-64% lower during shoulder horizontal adduction and abduction without fixation compared with exercises with fixation. The results indicate that upper limb exercises performed in the standing position are effective for activating core muscles. Bilateral and unilateral shoulder extension and unilateral shoulder horizontal abduction and adduction with the pelvis fixed elicited the greatest activity of the core muscles.

  6. Hydrophobic Core Flexibility Modulates Enzyme Activity in HIV-1 Protease

    Mittal, Seema; Cai, Yufeng; Nalam, Madhavi N.L.; Bolon, Daniel N.A.; Schiffer, Celia A. (UMASS, MED)

    2012-09-11

    Human immunodeficiency virus Type-1 (HIV-1) protease is crucial for viral maturation and infectivity. Studies of protease dynamics suggest that the rearrangement of the hydrophobic core is essential for enzyme activity. Many mutations in the hydrophobic core are also associated with drug resistance and may modulate the core flexibility. To test the role of flexibility in protease activity, pairs of cysteines were introduced at the interfaces of flexible regions remote from the active site. Disulfide bond formation was confirmed by crystal structures and by alkylation of free cysteines and mass spectrometry. Oxidized and reduced crystal structures of these variants show the overall structure of the protease is retained. However, cross-linking the cysteines led to drastic loss in enzyme activity, which was regained upon reducing the disulfide cross-links. Molecular dynamics simulations showed that altered dynamics propagated throughout the enzyme from the engineered disulfide. Thus, altered flexibility within the hydrophobic core can modulate HIV-1 protease activity, supporting the hypothesis that drug resistant mutations distal from the active site can alter the balance between substrate turnover and inhibitor binding by modulating enzyme activity.

  7. Core Muscle Activity, Exercise Preference, and Perceived Exertion during Core Exercise with Elastic Resistance versus Machine

    Jonas Vinstrup

    2015-01-01

    Full Text Available Objectives. To investigate core muscle activity, exercise preferences, and perceived exertion during two selected core exercises performed with elastic resistance versus a conventional training machine. Methods. 17 untrained men aged 26–67 years participated in surface electromyography (EMG measurements of five core muscles during torso-twists performed from left to right with elastic resistance and in the machine, respectively. The order of the exercises was randomized and each exercise consisted of 3 repetitions performed at a 10 RM load. EMG amplitude was normalized (nEMG to maximum voluntary isometric contraction (MVC. Results. A higher right erector spinae activity in the elastic exercise compared with the machine exercise (50% [95% CI 36–64] versus 32% [95% CI 18–46] nEMG was found. By contrast, the machine exercise, compared with the elastic exercise, showed higher left external oblique activity (77% [95% CI 64–90] versus 54% [95% CI 40–67] nEMG. For the rectus abdominis, right external oblique, and left erector spinae muscles there were no significant differences. Furthermore, 76% preferred the torso-twist with elastic resistance over the machine exercise. Perceived exertion (Borg CR10 was not significantly different between machine (5.8 [95% CI 4.88–6.72] and elastic exercise (5.7 [95% CI 4.81–6.59]. Conclusion. Torso-twists using elastic resistance showed higher activity of the erector spinae, whereas torso-twist in the machine resulted in higher activity of the external oblique. For the remaining core muscles the two training modalities induced similar muscular activation. In spite of similar perceived exertion the majority of the participants preferred the exercise using elastic resistance.

  8. The Activity Reaction Core and Plasticity of Metabolic Networks.

    2005-12-01

    Full Text Available Understanding the system-level adaptive changes taking place in an organism in response to variations in the environment is a key issue of contemporary biology. Current modeling approaches, such as constraint-based flux-balance analysis, have proved highly successful in analyzing the capabilities of cellular metabolism, including its capacity to predict deletion phenotypes, the ability to calculate the relative flux values of metabolic reactions, and the capability to identify properties of optimal growth states. Here, we use flux-balance analysis to thoroughly assess the activity of Escherichia coli, Helicobacter pylori, and Saccharomyces cerevisiae metabolism in 30,000 diverse simulated environments. We identify a set of metabolic reactions forming a connected metabolic core that carry non-zero fluxes under all growth conditions, and whose flux variations are highly correlated. Furthermore, we find that the enzymes catalyzing the core reactions display a considerably higher fraction of phenotypic essentiality and evolutionary conservation than those catalyzing noncore reactions. Cellular metabolism is characterized by a large number of species-specific conditionally active reactions organized around an evolutionary conserved, but always active, metabolic core. Finally, we find that most current antibiotics interfering with bacterial metabolism target the core enzymes, indicating that our findings may have important implications for antimicrobial drug-target discovery.

  9. Bubble mass center and fluid feedback force fluctuations activated by constant lateral impulse with variable thrust

    Hung, R. J.; Long, Y. T.

    1995-01-01

    Sloshing dynamics within a partially filled rotating dewar of superfluid helium 2 are investigated in response to constant lateral impulse with variable thrust. The study, including how the rotating bubble of superfluid helium 2 reacts to the constant impulse with variable time period of thrust action in microgravity, how amplitudes of bubble mass center fluctuates with growth and decay of disturbances, and how fluid feedback forces fluctuates in activating on the rotating dewar through the dynamics of sloshing waves are investigated. The numerical computation of sloshing dynamics is based on the non-inertial frame spacecraft bound coordinate with lateral impulses actuating on the rotating dewar in both inertial and non-inertial frames of thrust. Results of the simulations are illustrated.

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

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

    2016-09-16

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

  11. Reduction of aerodynamic load fluctuation on wind turbine blades through active flow control

    Velarde, John-Michael; Coleman, Thomas; Magstadt, Andrew; Aggarwal, Somil; Glauser, Mark

    2015-11-01

    The current set of experiments deals with implementing active flow control on a Bergey Excel 1, 1kW turbine. The previous work in our group demonstrated successfully that implementation of a simple closed-loop controller could reduce unsteady aerodynamic load fluctuation by 18% on a vertically mounted wing. Here we describe a similar flow control method adapted to work in the rotating frame of a 2.5m diameter wind turbine. Strain gages at the base of each blade measure the unsteady fluctuation in the blades and pressure taps distributed along the span of the blades feed information to the closed-loop control scheme. A realistic, unsteady flow field has been generated by placing a cylinder upstream of the turbine to induce shedding vortices at frequencies in the bandwidth of the first structural bending mode of the turbine blades. The goal of these experiments is to demonstrate closed-loop flow control as a means to reduce the unsteady fluctuation in the blades and increase the overall lifespan of the wind turbine.

  12. Robustness of nuclear core activity reconstruction by data assimilation

    Bouriquet, Bertrand, E-mail: bertrand.bouriquet@cerfacs.f [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No. 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Argaud, Jean-Philippe [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No. 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Erhard, Patrick [Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Massart, Sebastien [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No. 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Poncot, Angelique [Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Ricci, Sophie [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No. 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Thual, Olivier [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No. 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Universite de Toulouse, INPT, UPS, IMFT, Allee Camille Soula, F-31400 Toulouse (France)

    2011-02-11

    We apply a data assimilation technique, inspired from meteorological applications, to perform an optimal reconstruction of the neutronic activity field in a nuclear core. Both measurements and information coming from a numerical model are used. We first study the robustness of the method when the amount of measured information decreases. We then study the influence of the nature of the instruments and their spatial repartition on the efficiency of the field reconstruction.

  13. CORE

    Krigslund, Jeppe; Hansen, Jonas; Hundebøll, Martin

    2013-01-01

    different flows. Instead of maintaining these approaches separate, we propose a protocol (CORE) that brings together these coding mechanisms. Our protocol uses random linear network coding (RLNC) for intra- session coding but allows nodes in the network to setup inter- session coding regions where flows...... intersect. Routes for unicast sessions are agnostic to other sessions and setup beforehand, CORE will then discover and exploit intersecting routes. Our approach allows the inter-session regions to leverage RLNC to compensate for losses or failures in the overhearing or transmitting process. Thus, we...... increase the benefits of XORing by exploiting the underlying RLNC structure of individual flows. This goes beyond providing additional reliability to each individual session and beyond exploiting coding opportunistically. Our numerical results show that CORE outperforms both forwarding and COPE...

  14. Thermal ignition revisited with molecular dynamics: role of fluctuations in activated collisions

    Sirmas, Nick

    2016-01-01

    The problem of thermal ignition in a homogeneous gas is revisited from a molecular dynamics perspective. The simple model assumes reactive particles of type A and B in a fixed domain that react to form type C products if an activation threshold for impact is surpassed. Such a reaction liberates kinetic energy to the product particles, representative of the heat release. The results are compared with those obtained from the continuum description with the reaction rate evaluated from kinetic theory assuming local thermodynamic equilibrium and Maxwell-Boltzmann statistics, in order to assess the role played by molecular fluctuations. Results show that at low activation energies, the ignition time obtained from the molecular dynamics is independent of domain size, with values exceeding what is expected from the continuum model for all values of heat release. The ignition time was found dependent on domain size for larger activation energies. Small domains of $N=100$ particles yielded longer ignition delays than p...

  15. Physical activity, sleep duration and metabolic health in children fluctuate with the lunar cycle

    Sjödin, Anders Mikael; Hjorth, Mads Fiil; Damsgaard, Camilla Trab

    2015-01-01

    glucose regulation and physical activity to improve glucose regulation, one could speculate that cardiometabolic risk factors might also be affected by the lunar phase. We retrospectively examined 795 Danish children, aged 8-11 years, with more than 13 000 24-h accelerometer recordings of activity...... and sleep as well as 2000 measurements of different cardiometabolic risk factors, including insulin sensitivity, appetite hormones and blood pressure, during nine lunar phases. During the period around full moon, children were 5.0 and 3.2 min per day less active, slept 2.4 and 4.1 min per night longer, had...... behaviour and the lunar cycle or confounders that may explain this, apparently leading to fluctuation in a number of cardiometabolic risk markers conjointly with lunar phases....

  16. Variability of single trial brain activation predicts fluctuations in reaction time.

    Bender, Stephan; Banaschewski, Tobias; Roessner, Veit; Klein, Christoph; Rietschel, Marcella; Feige, Bernd; Brandeis, Daniel; Laucht, Manfred

    2015-03-01

    Brain activation stability is crucial to understanding attention lapses. EEG methods could provide excellent markers to assess neuronal response variability with respect to temporal (intertrial coherence) and spatial variability (topographic consistency) as well as variations in activation intensity (low frequency variability of single trial global field power). We calculated intertrial coherence, topographic consistency and low frequency amplitude variability during target P300 in a continuous performance test in 263 15-year-olds from a cohort with psychosocial and biological risk factors. Topographic consistency and low frequency amplitude variability predicted reaction time fluctuations (RTSD) in a linear model. Higher RTSD was only associated with higher psychosocial adversity in the presence of the homozygous 6R-10R dopamine transporter haplotype. We propose that topographic variability of single trial P300 reflects noise as well as variability in evoked cortical activation patterns. Dopaminergic neuromodulation interacted with environmental and biological risk factors to predict behavioural reaction time variability.

  17. The role of statistical fluctuations on the stability of shockwaves through gases with activated inelastic collisions

    Sirmas, Nick; Radulescu, Matei

    2016-11-01

    The present study addresses the stability of piston driven shock waves through a system of hard particles subject to activated inelastic collisions. Molecular Dynamics (MD) simulations have previously revealed an unstable structure for such a system in the form of high density non-uniformities and convective rolls within the shock structure. The work has now been extended to the continuum level by considering the Euler and Navier-Stokes equations for granular gases with a modified cooling rate to include an impact threshold necessary for inelastic collisions. We find that the pattern formations produced in MD can be reproduced at the continuum level by continually perturbing the incoming density field. By varying the perturbation amplitude and wavelength, we find that fluctuations consistent with the statistical fluctuations seen in MD yield similar instabilities to those previously observed. While the inviscid model predicts a highly chaotic structure from these perturbations, the inclusion of viscosity and heat conductivity yields equivalent wavelengths of pattern formations to those seen in MD, which is equal to the relaxation length scale of the dissipative shock structure. The authors acknowledged funding through the Alexander Graham Bell Canada Graduate Scholarship (NSERC) and Ontario Graduate Scholarship.

  18. Fluctuations in Activity Demands Across Game Quarters in Professional and Semiprofessional Male Basketball.

    Scanlan, Aaron T; Tucker, Patrick S; Dascombe, Ben J; Berkelmans, Daniel M; Hiskens, Matthew I; Dalbo, Vincent J

    2015-11-01

    Examination of activity demands and stoppage durations across game periods provides useful insight concerning fatigue, tactical strategies, and playing pace in team sports such as basketball. Therefore, the aims of this study were to quantify and compare game activity fluctuations across quarters in professional and semiprofessional basketball players. Video-based time-motion analyses were conducted across multiple games. Frequencies, total durations (in seconds), total distances (in meters), and mean velocities (in meters per second) were calculated for low-intensity movement (≤3 m·s), high-intensity movement (>3 m·s), shuffling, and dribbling activity. Frequencies were determined for jumping and upper-body activity; stoppage durations were also calculated. Separate repeated-measures analysis of variance and Cohen's d were used to identify significant differences and quantify the effect sizes between game quarters for all outcome measures, respectively. Pearson correlation analyses were performed to determine the relationship between stoppage duration and all activity measures. The results showed significantly (p ≤ 0.05) reduced dribbling (3.09 ± 0.03 m·s vs. 2.81 ± 0.01 m·s) and total (2.22 ± 0.04 m·s vs. 2.09 ± 0.03 m·s) activity velocities during the third compared with the first quarter in professional players. Furthermore, effect size analyses showed greater decreases in high-intensity (professional: d = 1.7-5.4; semiprofessional: d = 0.3-1.7), shuffling (professional: d = 2.3-3.2; semiprofessional: d = 1.4-2.1), and total (professional: d = 1.0-4.9; semiprofessional: d = 0.3-0.8) activity and increases in dribbling (professional: d = 1.4-4.7; semiprofessional: d = 2.5-2.8) with game progression in professional players. In semiprofessional players, stoppage duration was significantly (p ≤ 0.05) related to various low-intensity (R = 0.64-0.72), high-intensity (R = 0.65-0.72), and total (R = 0.63-0.73) activity measures. Although not directly

  19. Coupling between spontaneous pupillary fluctuations and brain activity relates to inattentiveness.

    Breeden, A L; Siegle, G J; Norr, M E; Gordon, E M; Vaidya, C J

    2017-01-01

    Autonomic activity in neurological and psychiatric disorders is often dysregulated, particularly in the context of attentional behaviors. This suggests that interplay between the autonomic nervous system and aspects of the central nervous system subserving attention may be disrupted in these conditions. Better understanding these interactions and their relationship with individual variation in attentional behaviors could facilitate development of mechanistic biomarkers. We identified brain regions defined by trait-sensitive central-autonomic coupling as a first step in this process. As spontaneous neural activity measured during the resting state is sensitive to phenotypic variability, unconfounded by task performance, we examined whether spontaneous fluctuations in brain activity and an autonomic measure, pupil diameter, were coupled during the resting state, and whether that coupling predicted individual differences in attentional behavior. By employing concurrent pupillometry and fMRI during the resting state, we observed positive coupling in regions comprising cingulo-opercular, default mode, and fronto-parietal networks, as well as negative coupling with visual and sensorimotor regions. Individuals less prone to distractibility in everyday behavior demonstrated stronger positive coupling in cingulo-opercular regions often associated with sympathetic activity. Overall, our results suggest that individuals less prone to distractibility have tighter intrinsic coordination between specific brain areas and autonomic systems, which may enable adaptive autonomic shifts in response to salient environmental cues. These results suggest that incorporating autonomic indices in resting-state studies should be useful in the search for biomarkers for neurological and psychiatric disorders.

  20. The effect of active fluctuations on the dynamics of particles, motors and hairpins

    Vandebroek, Hans

    2016-01-01

    Inspired by recent experiments on the dynamics of particles and polymers in artificial cytoskeletons and in cells, we introduce a modified Langevin equation for a particle in an environment that is a viscoelastic medium and that is brought out of equilibrium by the action of active fluctuations caused by molecular motors. We show that within such a model, the motion of a free particle crosses over from superdiffusive to subdiffusive as observed for tracer particles in an {\\it in vitro} cytoskeleton or in a cell. We investigate the dynamics of a particle confined by a harmonic potential as a simple model for the motion of the tethered head of kinesin-1. We find that the probability that the head is close to its binding site on the microtubule can be enhanced by a factor of two due to active forces. Finally, we study the dynamics of a particle in a double well potential as a model for the dynamics of DNA-hairpins. We show that the active forces effectively lower the potential barrier between the two minima and ...

  1. Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE

    Warren, Harry P.; Winebarger, Amy R.; Brooks, David H.

    2010-03-01

    The timescale for energy release is an important parameter for constraining the coronal heating mechanism. Observations of "warm" coronal loops (~1 MK) have indicated that the heating is impulsive and that coronal plasma is far from equilibrium. In contrast, observations at higher temperatures (~3 MK) have generally been consistent with steady heating models. Previous observations, however, have not been able to exclude the possibility that the high temperature loops are actually composed of many small-scale threads that are in various stages of heating and cooling and only appear to be in equilibrium. With new observations from the EUV Imaging Spectrometer and X-ray Telescope (XRT) on Hinode we have the ability to investigate the properties of high temperature coronal plasma in extraordinary detail. We examine the emission in the core of an active region and find three independent lines of evidence for steady heating. We find that the emission observed in XRT is generally steady for hours, with a fluctuation level of approximately 15% in an individual pixel. Short-lived impulsive heating events are observed, but they appear to be unrelated to the steady emission that dominates the active region. Furthermore, we find no evidence for warm emission that is spatially correlated with the hot emission, as would be expected if the high temperature loops are the result of impulsive heating. Finally, we also find that intensities in the "moss," the footpoints of high temperature loops, are consistent with steady heating models provided that we account for the local expansion of the loop from the base of the transition region to the corona. In combination, these results provide strong evidence that the heating in the core of an active region is effectively steady, that is, the time between heating events is short relative to the relevant radiative and conductive cooling times.

  2. Active Heave-Compensated Coring On The New Jersey Shelf

    Nielson, D. L.; Pardey, M.; Austin, J. A.; Goff, J. A.; Alexander, C.; Christensen, B. A.; Gulick, S. P.; Fulthorpe, C. S.; Nordfjord, S.; Sommerfield, C.; Venherm, C.

    2003-12-01

    The continental shelves are of obvious scientific and strategic importance. However, the ability to cost-effectively collect core samples of continental shelf sediments has been limited by technical difficulties. Many sites of scientific interest are too shallow to be drilled by large drill ships, and they are too deep to be drilled economically from jack-up platforms. DOSECC has developed an Active Heave Compensated (AHC800) drilling system under sponsorship of the Office of Naval Research to overcome these obstacles by building a small active heave compensated drilling rig that can be used to collect high-quality core from selected vessels of opportunity. The AHC800 drilling rig is designed to collect continuous core to a total drill string length of 800 m. Water depths of 200 m and less are optimal; however, with some modification operation in deeper water is possible. The AHC800 senses vessel heave using a constantly tensioned low-stretch taut line attached to a seafloor weight. A linear position transducer is attached to this taut line and through the data acquisition system, the ship's distance from the bottom is communicated to the heave compensation computer running Labview RT operating system and object-based software language. This real-time control system is used to achieve a 10-ms control loop for both data gathering and output functions. The Labview RT system continuously controls two hydraulic cylinders that keep the heave carriage and the drill string at the same reference distance from the bottom. The AHC800 system was used on the R/V Knorr on the New Jersey continental shelf in water depths from 74 to 130 m from 25 Sep to 15 Oct 2002. The AHC800 system performed up to and beyond its design specifications. The rig was designed to compensate for 2.44 m of heave with an 8 s period. However, the Knorr's response was a 6 s period resulting in a significant increase in the required acceleration as well as a faster response time for the system as a whole

  3. Accumulation in Dasuopu ice core in Qinghai-Tibet Plateau and solar activity

    2000-01-01

    The time series of accumulation in recent 300 years correlated well with solar activity in Dasuopu ice core. Results of spectrum analysis on the accumulation time series of the Dasuopu ice core shows that there are some periods that coincide with the periods of solar activity. By comparing the long-time change trend of the accumulation in the Dasuopu ice core with various kinds of indexes of solar activity intensity, a negative correlation is found between the trend and solar activity.

  4. Activation of thermal denudation under recent climatic fluctuations, Central Yamal, Russia

    Khomutov, Artem; Dvornikov, Yury; Gubarkov, Anatoly; Mullanurov, Damir

    2016-04-01

    Climatic fluctuations over the past few years significantly affected the increase of cryogenic processes activity in the tundra zone of the Yamal Peninsula. On Central Yamal a large-scale cryogenic landsliding was observed in 1989, while cryogenic earth flows were actively developing since 2012 through tabular ground ice thawing. As a result, thermocirques form on lakeshores. Key area (research station "Vaskiny Dachi" on the Se-Yakha and the Mordy-Yakha interfluve) during the period from 1989 to 2012 was characterized by a local occurrence of thermal denudation. By 2010, remote sensing data showed that this process in the study area was usually inactive and thermocirques looked stabilized, overgrown by vegetation. Extremely warm summer of 2012 resulted in formation of new thermal denudation features, such as cryogenic translational landslides, cryogenic earth flows and furthermore, thermocirques, complex landforms resulting from ice wedges and tabular ground ice thaw. The 2012 warm season was characterized by a deeper active layer: at the end of the warm period deeper by 15% than the average for the 1993-2011. Observed were indications of a high pore pressure in the active layer: effuse of liquefied clay in the tension cracks on many slopes. By 2013, according to the field and remote sensing data, there were more than 90 active thermal denudation landforms from 66 to 25000 sq.m in size on the territory of 345 sq.km. Thus, at the present in the tundra of the Yamal Peninsula the predominance of the processes associated with tabular ground ice thawing (cryogenic earth flows) over the processes associated with the ice formation at the bottom of the active layer (cryogenic translational landslides) is observed. It is caused by both a periodic deepening of the active layer, and consecutive increase of ground temperature. Activation of thermal denudation observed on the Yamal Peninsula last years is associated with extremely warm spring and summer of 2012. By the end of

  5. Who Can You Turn to? Tie Activation within Core Business Discussion Networks

    Renzulli, Linda A.; Aldrich, Howard

    2005-01-01

    We examine the connection between personal network characteristics and the activation of ties for access to resources during routine times. We focus on factors affecting business owners' use of their core network ties to obtain legal, loan, financial and expert advice. Owners rely more on core business ties when their core networks contain a high…

  6. OCT intensity and phase fluctuations correlated with activity-dependent neuronal calcium dynamics in the Drosophila CNS [Invited

    Tong, Minh Q.; Hasan, Md. Monirul; Lee, Sang Soo; Haque, Md. Rezuanul; Kim, Do-Hyoung; Islam, Md. Shahidul; Adams, Michael E.; Park, B. Hyle

    2017-01-01

    Phase-resolved OCT and fluorescence microscopy were used simultaneously to examine stereotypic patterns of neural activity in the isolated Drosophila central nervous system. Both imaging modalities were focused on individually identified bursicon neurons known to be involved in a fixed action pattern initiated by ecdysis-triggering hormone. We observed clear correspondence of OCT intensity, phase fluctuations, and activity-dependent calcium-induced fluorescence.

  7. Microbial growth fluctuating in response to solar-terrestrial activity variations.

    Voychuk, S I; Gromozova, E N

    2012-01-01

    Populations of microorganisms display fluctuations in the variable physiological and biochemical properties during cultivation under constant laboratory conditions. A series of explanations were proposed for this phenomenon, and different factors were studied as possible regulators. It was found that such fluctuations possess cosmic rhythms, but no factor(s) were proposed that could sufficiently explain and predict the magnitude of changes that happened on a daily basis in the long-term experiments. In this study we investigated specific growth rate fluctuations of Saccharomyces cerevisiae yeasts that were marked daily during cultivation under constant conditions. The effects of different solar and terrestrial factors were then analysed. The significant correlation indices were found for growth rate fluctuations against solar wind speed and the number of flares M on the Sun. These two factors determined the cyclic nature of the growth rate fluctuations, and thus its general course of increase or decrease. The effects of several other factors (Flares C number, planetary A index variation, and changes in the atmospheric factors such as temperature and humidity) and their two-way interactions were significant in producing an equation to describe the magnitude of changes of the yeast's growth parameters. The R2 of the equation achieved 91% and adjusted R2 was 78%. It is obvious that temperature and humidity are the factors that cannot directly influence the yeast populations under laboratory conditions and thus we suppose that they only reflect modifications of the really important factor(s) that take place in the Earth's atmosphere. We have concluded that different solar and terrestrial factors are responsible for the fluctuations in the daily kinetic parameters of the yeast growth.

  8. Massive molecular cloud cores and activities of star formation

    Zhou Wu-Fei; Wu Yue-Fang; Wei Yue; Ju Bing-Gang

    2005-01-01

    We have mapped 23 sources in the J=1-0 lines of 12CO, 13CO and C18O with the 13.7-m telescope at Qinghai station of Purple Mountain Observatory. The samples were chosen from the massive star formation regions whose single point lines have the broad-wing profile. The mapping shows that 12 clouds have cores and 5 outflows were identified with the 12CO J=1-0 lines. Among the 12 cores, systematic velocity shifts were found in 2 cores, and blue asymmetric double-peak profile of 12CO line was found in IRAS 19529+2704, indicating that it may be an infall candidate. Physical parameters of the cores and outflows were derived from the local thermodynamic equilibrium assumption. The masses range from ~ 9.4 × 102M⊙ to ~ 2.2 × 105M⊙. The hydrogen molecule densities range from ~ 3.4 × 102cm-3 to~ 1.2 × 104cm-3. The molecular outflows have masses larger than 3.5M⊙, and kinetic energies greater than 0.9× 1038J.The outflows have significantly greater masses and kinetic energies than those from low-mass young stellar objects(YSOs). For the cores, 2MASS data are available, dozens of 2MASS sources with different colour indices and brightness are often found around IRAS source, among which the reddest 2MASS source is always within the IRAS error ellipse thus probably corresponds to the IRAS source.

  9. New evidence for possible impact of solar activity on long-term fluctuation of the earth rotation

    2001-01-01

    The long-term fluctuation of the Schwabe period (LSP) of sunspots number (SSN) has been found to have high correlation with the variation of the length-of-day (LOD) in low frequency by using the data of smoothed monthly mean SSN during 1818-1999 and the method of wavelet transform. Analyses indicate that the maximum correlation coefficient between the series of LSP and LOD during 1892-1997 is about 0.9, with a time lag of about 5 years for the LOD related to the LSP. Though the maximum correlation coefficients between the LSP and the other two LOD series (1818-1997) reduce to about 0.4, they remain over the thresholds of 95% confidence level. This suggests new evidence for possible impact of solar activity on the long-term fluctuation of the earth rotation.

  10. Glacier Ice Mass Fluctuations and Fault Instability in Tectonically Active Southern Alaska

    SauberRosenberg, Jeanne M.; Molnia, Bruce F.

    2003-01-01

    Across southern Alaska the northwest directed subduction of the Pacific plate is accompanied by accretion of the Yakutat terrane to continental Alaska. This has led to high tectonic strain rates and dramatic topographic relief of more than 5000 meters within 15 km of the Gulf of Alaska coast. The glaciers of this area are extensive and include large glaciers undergoing wastage (glacier retreat and thinning) and surges. The large glacier ice mass changes perturb the tectonic rate of deformation at a variety of temporal and spatial scales. We estimated surface displacements and stresses associated with ice mass fluctuations and tectonic loading by examining GPS geodetic observations and numerical model predictions. Although the glacial fluctuations perturb the tectonic stress field, especially at shallow depths, the largest contribution to ongoing crustal deformation is horizontal tectonic strain due to plate convergence. Tectonic forces are thus the primary force responsible for major earthquakes. However, for geodetic sites located Glacier s most recent surge cycle are large enough to cause discernible surface displacements. Additionally, ice mass fluctuations associated with the surge cycle can modify the short-term seismicity rates in a local region. For the thrust faulting environment of the study region a large decrease in ice load may cause an increase in seismic rate in a region close to failure whereas ice loading may inhibit thrust faulting.

  11. Modulation of mitogen-activated protein kinase-activated protein kinase 3 by hepatitis C virus core protein

    Ngo, HT; Pham, Long; Kim, JW;

    2013-01-01

    Hepatitis C virus (HCV) is highly dependent on cellular proteins for its own propagation. In order to identify the cellular factors involved in HCV propagation, we performed protein microarray assays using the HCV core protein as a probe. Of ~9,000 host proteins immobilized in a microarray......, approximately 100 cellular proteins were identified as HCV core-interacting partners. Of these candidates, mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) was selected for further characterization. MAPKAPK3 is a serine/threonine protein kinase that is activated by stress and growth...... inducers. Binding of HCV core to MAPKAPK3 was confirmed by in vitro pulldown assay and further verified by coimmunoprecipitation assay. HCV core protein interacted with MAPKAPK3 through amino acid residues 41 to 75 of core and the N-terminal half of kinase domain of MAPKAPK3. In addition, both RNA...

  12. Hepatic inflammation mediated by hepatitis C virus core protein is ameliorated by blocking complement activation

    Hsu Chen-Ming

    2009-08-01

    Full Text Available Abstract Background The pathogenesis of inflammation and fibrosis in chronic hepatitis C virus (HCV infection remains unclear. Transgenic mice with constitutive HCV core over-expression display steatosis only. While the reasons for this are unclear, it may be important that core protein production in these models begins during gestation, in contrast to human hepatitis C virus infection, which occurs post-natally and typically in adults. AIMS: To more realistically model the effect of core protein production in the adult liver, we developed a mouse with conditional expression of HCV core and examined the effect of core protein production in the adult liver. Methods Liver biopsy samples from transgenic mice with tetracycline(tet-regulated conditional core protein expression were evaluated immunohistologically. Microarray analysis of HCV core transgenic mice with steatohepatitis pointed to a role of the complement pathway. This was further explored by blocking complement activation by in vivo administration of CD55 (decay accelerating factor for complement, which inhibits activation of C3. Results Transgenic mice exhibited low, intermediate, or high HCV core protein expression when fed a permissive diet of standard chow. Aside from hepatic steatosis, hepatic inflammation and fibrosis were seen in mice with intermediate levels of core protein. Microarray analyses of inflamed liver demonstrated activation of both the complement (C3 up-regulation and coagulation pathways (fibrinogen B up-regulation. Administration of CD55 reduced hepatic inflammation. Conclusion Transgenic mice that conditionally express intermediate HCV core protein develop inflammation, steatosis, and fibrosis. These effects mediated by HCV core are reduced by administration of CD55, a regulator of the complement pathway. The model may be valuable in investigating the pathogenesis of liver inflammation in chronic hepatitis C.

  13. Dynamical core polarization of two-active-electron systems in strong laser fields

    Zhao, Zengxiu

    2013-01-01

    The ionization of two-active-electron systems by intense laser fields is investigated theoretically. In comparison with time-dependent Hartree-Fock and exact two electron simulation, we show that the ionization rate is overestimated in SAE approximation. A modified single-active-electron model is formulated by taking into account of the dynamical core polarization. Applying the new approach to Ca atoms, it is found that the polarization of the core can be considered instantaneous and the large polarizability of the cation suppresses the ionization by 50% while the photoelectron cut-off energy increases slightly. The existed tunneling ionization formulation can be corrected analytically by considering core polarization.

  14. Differential influence of instruments in nuclear core activity evaluation by data assimilation

    Bouriquet, Bertrand, E-mail: bertrand.bouriquet@cerfacs.f [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Argaud, Jean-Philippe [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Erhard, Patrick [Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Massart, Sebastien [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Poncot, Angelique [Electricite de France, 1 avenue du General de Gaulle, F-92141 Clamart Cedex (France); Ricci, Sophie [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Thual, Olivier [Sciences de l' Univers au CERFACS, URA CERFACS/CNRS No 1875, 42 avenue Gaspard Coriolis, F-31057 Toulouse Cedex 01 (France); Universite de Toulouse, INPT, UPS, IMFT, Allee Camille Soula, F-31400 Toulouse (France)

    2011-01-21

    The global neutronic activity fields of a nuclear core can be reconstructed using data assimilation. Indeed, data assimilation allows to combine both measurements from instruments and information from a model, to evaluate the best possible neutronic activity within the core. We present and apply a specific procedure which evaluates the influence of measures by adding or removing instruments in a given measurement network (possibly empty). The study of various network configurations for the instruments in the nuclear core establishes that the influence of the instruments depends both on the independent instrumentation location and on the chosen network.

  15. Thermal analysis of HTS air-core transformer used in voltage compensation type active SFCL

    Song, M.; Tang, Y.; Li, J.; Zhou, Y.; Chen, L.; Ren, L.

    2010-11-01

    The three-phase voltage compensation type active superconducting fault current limiter (SFCL) is composed of three HTS air-core transformers and a three-phase four-wire Pulse Width Modulation (PWM) converter. The primary winding of the each phase HTS air-core transformer is in series with the main system, and the second winding is connected with the PWM converter. The single-phase conduction-cooled HTS air-core transformer is consisting of four double-pancakes wound by the Bi2223/Ag tape. In this paper, according to the electromagnetic analysis on the single-phase HTS air-core transformer, its AC loss corresponding to different operation modes is calculated. Furthermore, the thermal behaviors are studied by the time-stepping numerical simulations. On the basis of the simulation results, the related problems with the HTS air-core transformer's thermal stability are discussed.

  16. Ecophysiology of novel core phylotypes in activated sludge wastewater treatment plants with nutrient removal

    McIlroy, Simon Jon; Awata, Takanori; Nierychlo, Marta

    An in depth understanding of the ecology of activated sludge nutrient removal wastewater treatment systems requires detailed knowledge of the community composition and metabolic activities of individual members. Recent 16S rRNA gene amplicon surveys of activated sludge wastewater treatment plants...... with nutrient removal in Denmark indicate a core set of bacterial genera. These core genera are suggested to be responsible for the bulk of nutrient transformations underpinning the functions of these plants. While we know the basic in situ activities of some of these genera, there is little to no information...

  17. Core-shell Au@Pd nanoparticles with enhanced catalytic activity for oxygen reduction reaction via core-shell Au@Ag/Pd constructions.

    Chen, Dong; Li, Chengyin; Liu, Hui; Ye, Feng; Yang, Jun

    2015-07-06

    Core-shell nanoparticles often exhibit improved catalytic properties due to the lattice strain created in these core-shell particles. Herein, we demonstrate the synthesis of core-shell Au@Pd nanoparticles from their core-shell Au@Ag/Pd parents. This strategy begins with the preparation of core-shell Au@Ag nanoparticles in an organic solvent. Then, the pure Ag shells are converted into the shells made of Ag/Pd alloy by galvanic replacement reaction between the Ag shells and Pd(2+) precursors. Subsequently, the Ag component is removed from the alloy shell using saturated NaCl solution to form core-shell Au@Pd nanoparticles with an Au core and a Pd shell. In comparison with the core-shell Au@Pd nanoparticles upon directly depositing Pd shell on the Au seeds and commercial Pd/C catalysts, the core-shell Au@Pd nanoparticles via their core-shell Au@Ag/Pd templates display superior activity and durability in catalyzing oxygen reduction reaction, mainly due to the larger lattice tensile effect in Pd shell induced by the Au core and Ag removal.

  18. Microfluidic synthesis of Ag@Cu2O core-shell nanoparticles with enhanced photocatalytic activity.

    Tao, Sha; Yang, Mei; Chen, Huihui; Ren, Mingyue; Chen, Guangwen

    2017-01-15

    A microfluidic-based method for the continuous synthesis of Ag@Cu2O core-shell nanoparticles (NPs) has been developed. It only took 32s to obtain Ag@Cu2O core-shell NPs, indicating a high efficiency of this microfluidic-based method. Triangular Ag nanoprisms were employed as the cores for the overgrowth of Cu2O through the reduction of Cu(OH)4(2-) with ascorbic acid. The as-synthesized samples were characterized by XRD, TEM, SEM, HAADF-STEM, EDX, HRTEM, UV-vis spectra and N2 adsorption-desorption. The characterization results revealed that the as-synthesized Ag@Cu2O core-shell NPs exhibited a well-defined core-shell nanostructure with a polycrystalline shell, which was composed of numbers of Cu2O domains epitaxially growing on the triangular Ag nanoprism. It was concluded that the synthesis parameters such as the molar ratio of trisodium citrate to AgNO3, H2O2 to AgNO3, NaOH to CuSO4, ascorbic acid to CuSO4 and AgNO3 to CuSO4 had significant effect on the synthesis of Ag@Cu2O core-shell NPs. Moreover, Ag@Cu2O core-shell NPs exhibited superior catalytic activity in comparison with pristine Cu2O NPs towards the visible light-driven degradation of methyl orange. This enhanced photocatalytic activity of Ag@Cu2O core-shell NPs was attributed to the larger BET surface area and improved charge separation efficiency. The trapping experiment indicated that holes and superoxide anion radicals were the major reactive species in the photodegradation of methyl orange over Ag@Cu2O core-shell NPs. In addition, Ag@Cu2O core-shell NPs showed no obvious deactivation in the cyclic test.

  19. Density Fluctuation Measurements Using FIR Interferometer on HL-2A Tokamak

    ZHOU Yan; PENG Bei-Bin; YANG Qing-wei; DUAN Xu-Ru; DING Xuan-Tong; LI Lian-Cai; LI Yong-Gao; JIAO Yi-Ming; DENG Zhong-Chao; YI Jiang; LIU Yi; ZHAO Kai-Jun; JI Xiao-Quan

    2008-01-01

    Denity fluctuations were first measured in the core region of HL-2A tokamak plasma using a newly developed multi-channel FIR interferometer system. In divertor ohmic discharges, we measured the radial density fluctuation levels of 5%, which increase to 10-20% during the appearance of MHD activity. Most of the power density in the density fluctuation spectrum is directly associated with m=2 tearing modes. The fluctuation levels reduce to 1/3 and plasma confinement is improved during off-axis electron-cyclotron-resonance heating (ECRH).Supported by the National Natural Science Foundation of China under Grant Nos 10575030 and 10675043.

  20. Thermosensitive Cu2O-PNIPAM core-shell nanoreactors with tunable photocatalytic activity

    Jia, He; Angioletti-Uberti, Stefano; Henzler, Katja; Ott, Andreas; Lin, Xianzhong; Möser, Jannik; Kochovski, Zdravko; Schnegg, Alexander; Dzubiella, Joachim; Ballauff, Matthias; Lu, Yan

    2016-01-01

    We report a facile and novel method for the fabrication of Cu2O@PNIPAM core-shell nanoreactors using Cu2O nanocubes as the core. The PNIPAM shell not only effectively protects the Cu2O nanocubes from oxidation, but also improves the colloidal stability of the system. The Cu2O@PNIPAM core-shell microgels can work efficiently as photocatalyst for the decomposition of methyl orange under visible light. A significant enhancement in the catalytic activity has been observed for the core-shell microgels compared with the pure Cu2O nanocubes. Most importantly, the photocatalytic activity of the Cu2O nanocubes can be further tuned by the thermosensitive PNIPAM shell, as rationalized by our recent theory.

  1. Electrosprayed core-shell polymer-lipid nanoparticles for active component delivery

    Eltayeb, Megdi; Stride, Eleanor; Edirisinghe, Mohan

    2013-11-01

    A key challenge in the production of multicomponent nanoparticles for healthcare applications is obtaining reproducible monodisperse nanoparticles with the minimum number of preparation steps. This paper focus on the use of electrohydrodynamic (EHD) techniques to produce core-shell polymer-lipid structures with a narrow size distribution in a single step process. These nanoparticles are composed of a hydrophilic core for active component encapsulation and a lipid shell. It was found that core-shell nanoparticles with a tunable size range between 30 and 90 nm and a narrow size distribution could be reproducibly manufactured. The results indicate that the lipid component (stearic acid) stabilizes the nanoparticles against collapse and aggregation and improves entrapment of active components, in this case vanillin, ethylmaltol and maltol. The overall structure of the nanoparticles produced was examined by multiple methods, including transmission electron microscopy and differential scanning calorimetry, to confirm that they were of core-shell form.

  2. Enhanced antibacterial activity of bimetallic gold-silver core-shell nanoparticles at low silver concentration

    Banerjee, Madhuchanda; Sharma, Shilpa; Chattopadhyay, Arun; Ghosh, Siddhartha Sankar

    2011-12-01

    Herein we report the development of bimetallic Au@Ag core-shell nanoparticles (NPs) where gold nanoparticles (Au NPs) served as the seeds for continuous deposition of silver atoms on its surface. The core-shell structure and morphology were examined by UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). The core-shell NPs showed antibacterial activity against both Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis and Pediococcus acidilactici) bacteria at low concentration of silver present in the shell, with more efficacy against Gram negative bacteria. TEM and flow cytometric studies showed that the core-shell NPs attached to the bacterial surface and caused membrane damage leading to cell death. The enhanced antibacterial properties of Au@Ag core-shell NPs was possibly due to the more active silver atoms in the shell surrounding gold core due to high surface free energy of the surface Ag atoms owing to shell thinness in the bimetallic NP structure.Herein we report the development of bimetallic Au@Ag core-shell nanoparticles (NPs) where gold nanoparticles (Au NPs) served as the seeds for continuous deposition of silver atoms on its surface. The core-shell structure and morphology were examined by UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD). The core-shell NPs showed antibacterial activity against both Gram negative (Escherichia coli and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis and Pediococcus acidilactici) bacteria at low concentration of silver present in the shell, with more efficacy against Gram negative bacteria. TEM and flow cytometric studies showed that the core-shell NPs attached to the bacterial surface and caused membrane damage leading to cell death. The enhanced antibacterial properties of Au@Ag core-shell NPs was

  3. Thermally-Activated Post-Glitch Response of the Neutron Star Inner Crust and Core

    Link, Bennett

    2013-01-01

    Pinning of superfluid vortices is predicted to prevail throughout much of a neutron star. Here I develop a description of the coupling through thermally-activated vortex slippage}, and calculate the post-glitch response of a neutron star to a spin glitch. The theory has three robust conclusions: 1) If vortex pinning occurs in the core, typical large glitches decouple the core superfluid from the charged components over observable timescales. Core response to a glitch has a distinct observational signature that could be identified through analyses of existing and future timing data. 2) Post-glitch response over short timescales (days) in pulsars with large glitches (fractional spin jumps of $\\Delta\

  4. Fluctuation of microbial activities after influent load variations in a full-scale SBR. Recovery of the biomass after starvation

    Cabezas, Angela; Draper, Patricia; Etchebehere, Claudia [Universidad de la Republica, Montevideo (Uruguay). Catedra de Microbiologia, Facultad de Quimica y Facultad de Ciencias

    2009-10-15

    Due to variations in the production levels, a full-scale sequencing batch reactor (SBR) for post-treatment of tannery wastewater was exposed to low and high ammonia load periods. In order to study how these changes affected the N-removal capacity, the microbiology of the reactor was studied by a diverse set of techniques including molecular tools, activity tests, and microbial counts in samples taken along 3 years. The recover capacity of the biomass was also studied in a lab-scale reactor operated with intermittent aeration without feeding for 36 days. The results showed that changes in the feeding negatively affected the nitrifying community, but the nitrogen removal efficiencies could be restored after the concentration stress. Species substitution was observed within the nitrifying bacteria, Nitrosomonas europaea and Nitrobacter predominated initially, and after an ammonia overload period, Nitrosomonas nitrosa and Nitrospira became dominant. Some denitrifiers, with nirS related to Alicycliphilus, Azospirillum, and Marinobacter nirS, persisted during long-term reactor operation, but the community fluctuated both in composition and in abundance. This fluctuating community may better resist the continuous changes in the feeding regime. Our results showed that a nitrifying-denitrifying SBR could be operated with low loads or even without feeding during production shut down periods. (orig.)

  5. Active control on high-order coherence and statistic characterization on random phase fluctuation of two classical point sources.

    Hong, Peilong; Li, Liming; Liu, Jianji; Zhang, Guoquan

    2016-03-29

    Young's double-slit or two-beam interference is of fundamental importance to understand various interference effects, in which the stationary phase difference between two beams plays the key role in the first-order coherence. Different from the case of first-order coherence, in the high-order optical coherence the statistic behavior of the optical phase will play the key role. In this article, by employing a fundamental interfering configuration with two classical point sources, we showed that the high- order optical coherence between two classical point sources can be actively designed by controlling the statistic behavior of the relative phase difference between two point sources. Synchronous position Nth-order subwavelength interference with an effective wavelength of λ/M was demonstrated, in which λ is the wavelength of point sources and M is an integer not larger than N. Interestingly, we found that the synchronous position Nth-order interference fringe fingerprints the statistic trace of random phase fluctuation of two classical point sources, therefore, it provides an effective way to characterize the statistic properties of phase fluctuation for incoherent light sources.

  6. Human activity under high pressure: A case study on fluctuation scaling of air traffic controller's communication behaviors

    Wang, Yanjun; Zhang, Qiqian; Zhu, Chenping; Hu, Minghua; Duong, Vu

    2016-01-01

    Recent human dynamics research has unmasked astonishing statistical characteristics such as scaling behaviors in human daily activities. However, less is known about the general mechanism that governs the task-specific activities. In particular, whether scaling law exists in human activities under high pressure remains an open question. In air traffic management system, safety is the most important factor to be concerned by air traffic controllers who always work under high pressure, which provides a unique platform to study human activity. Here we extend fluctuation scaling method to study air traffic controller's communication activity by investigating two empirical communication datasets. Taken the number of controlled flights as the size-like parameter, we show that the relationships between the average communication activity and its standard deviation in both datasets can be well described by Taylor's power law, with scaling exponent α ≈ 0.77 ± 0.01 for the real operational data and α ≈ 0.54 ± 0.01 for the real-time training data. The difference between the exponents suggests that human dynamics under pressure is more likely dominated by the exogenous force. Our findings may lead to further understanding of human behavior.

  7. Palynological record of tropical rain forest vegetation and sea level fluctuations since 140 ka from sediment core, south-eastern Arabian sea.

    Farooqui, A.; Pattan, J.N.; Parthiban, G.; Srivastava, J.; Ranjana

    to the present day flora in Kerala except Ongokea gore which is now present in South Africa and therefore, the provenance of pollen recorded in the studied core is Western Ghats of India. High percentage of planktic foraminifera and dinoflagellate cysts...

  8. Following fluctuating signs: Anomalous active superdiffusion of swimmers in anisotropic media

    Toner, John; Löwen, Hartmut; Wensink, Henricus H.

    2016-06-01

    Active (i.e., self-propelled or swimming) particles moving through an isotropic fluid exhibit conventional diffusive behavior. We report anomalous diffusion of an active particle moving in an anisotropic nematic background. While the translational motion parallel to the nematic director shows ballistic behavior, the long-time transverse motion is superdiffusive, with an anomalous scaling proportional to t lnt of the mean-square displacement with time t . This behavior is predicted by an analytical theory that we present here and is corroborated by numerical simulation of active particle diffusion in a simple lattice model for a nematic liquid crystal. It is universal for any collection of self-propelled elements (e.g., bacteria or active rods) moving in a nematic background, provided only that the swimmers are sufficiently dilute that their interactions with each other can be neglected and that they do not perform hairpin turns.

  9. Mesoscale infraslow spontaneous membrane potential fluctuations recapitulate high-frequency activity cortical motifs.

    Chan, Allen W; Mohajerani, Majid H; LeDue, Jeffrey M; Wang, Yu Tian; Murphy, Timothy H

    2015-07-20

    Neuroimaging of spontaneous, resting-state infraslow (regional connectivity that are analogous to cortical motifs observed from higher-frequency spontaneous activity and reflect the underlying framework of intracortical axonal projections.

  10. Associations of Sleep Quality and Awake Physical Activity with Fluctuations in Nocturnal Blood Pressure in Patients with Cardiovascular Risk Factors.

    Manabu Kadoya

    Full Text Available Sleep quality and awake physical activity are important behavioral factors involved in the occurrence of cardiovascular diseases, potentially through nocturnal blood pressure (BP changes. However, the impacts of quantitatively measured sleep quality and awake physical activity on BP fluctuation, and their relationships with several candidate causal factors for nocturnal hypertension are not well elucidated.This cross-sectional study included 303 patients registered in the HSCAA study. Measurements included quantitatively determined sleep quality parameters and awake physical activity obtained by actigraph, nocturnal systolic BP (SBP fall [100 × (1- sleep SBP/awake SBP ratio], apnea hypopnea index, urinary sodium and cortisol secretion, plasma aldosterone concentration and renin activity, insulin resistance index, parameters of heart rate variability (HRV, and plasma brain-derived neurotrophic factor (BDNF.Simple regression analysis showed that time awake after sleep onset (r = -0.150, a parameter of sleep quality, and awake physical activity (r = 0.164 were significantly correlated with nocturnal SBP fall. Among those, time awake after sleep onset (β = -0.179 and awake physical activity (β = 0.190 were significantly and independently associated with nocturnal SBP fall in multiple regression analysis. In a subgroup of patients without taking anti-hypertensive medications, both time awake after sleep onset (β = -0.336 and awake physical activity (β = 0.489 were more strongly and independently associated with nocturnal SBP falls.Sleep quality and awake physical activity were found to be significantly associated with nocturnal SBP fall, and that relationship was not necessarily confounded by candidate causal factors for nocturnal hypertension.

  11. Circadian fluctuations in circulating plasminogen activator inhibitor-1 are independent of feeding cycles in mice.

    Oishi, Katsutaka; Ohkura, Naoki; Yasumoto, Yuki; Yamamoto, Saori

    2017-01-01

    To evaluate the involvement of the day-night feeding cycle in the circadian regulation of circulating plasminogen activator inhibitor-1 (PAI-1) concentrations, mice were fed with a diet for eight hours during either daytime (DF) or nighttime (NF) for one week. The reversed feeding cycle did not affect the circadian phases of plasma PAI-1 levels as well as the nocturnal wheel-running activity, although the phase of Pai-1 mRNA expression was significantly advanced for 8.6 hours in the livers of DF, compared with NF mice. The day-night feeding cycle is not a critical Zeitgeber for circadian rhythm of circulating PAI-1.

  12. Hepatitis C virus core protein induces neuroimmune activation and potentiates Human Immunodeficiency Virus-1 neurotoxicity.

    Pornpun Vivithanaporn

    Full Text Available BACKGROUND: Hepatitis C virus (HCV genomes and proteins are present in human brain tissues although the impact of HIV/HCV co-infection on neuropathogenesis remains unclear. Herein, we investigate HCV infectivity and effects on neuronal survival and neuroinflammation in conjunction with HIV infection. METHODOLOGY: Human microglia, astrocyte and neuron cultures were infected with cell culture-derived HCV or exposed to HCV core protein with or without HIV-1 infection or HIV-1 Viral Protein R (Vpr exposure. Host immune gene expression and cell viability were measured. Patch-clamp studies of human neurons were performed in the presence or absence of HCV core protein. Neurobehavioral performance and neuropathology were examined in HIV-1 Vpr-transgenic mice in which stereotaxic intrastriatal implants of HCV core protein were performed. PRINCIPAL FINDINGS: HCV-encoded RNA as well as HCV core and non-structural 3 (NS3 proteins were detectable in human microglia and astrocytes infected with HCV. HCV core protein exposure induced expression of pro-inflammatory cytokines including interleukin-1β, interleukin-6 and tumor necrosis factor-α in microglia (p<0.05 but not in astrocytes while increased chemokine (e.g. CXCL10 and interleukin-8 expression was observed in both microglia and astrocytes (p<0.05. HCV core protein modulated neuronal membrane currents and reduced both β-III-tubulin and lipidated LC3-II expression (p<0.05. Neurons exposed to supernatants from HCV core-activated microglia exhibited reduced β-III-tubulin expression (p<0.05. HCV core protein neurotoxicity and interleukin-6 induction were potentiated by HIV-1 Vpr protein (p<0.05. HIV-1 Vpr transgenic mice implanted with HCV core protein showed gliosis, reduced neuronal counts together with diminished LC3 immunoreactivity. HCV core-implanted animals displayed neurobehavioral deficits at days 7 and 14 post-implantation (p<0.05. CONCLUSIONS: HCV core protein exposure caused neuronal injury

  13. Spontaneous Slow Fluctuation of EEG Alpha Rhythm Reflects Activity in Deep-Brain Structures: A Simultaneous EEG-fMRI Study.

    Kei Omata

    Full Text Available The emergence of the occipital alpha rhythm on brain electroencephalogram (EEG is associated with brain activity in the cerebral neocortex and deep brain structures. To further understand the mechanisms of alpha rhythm power fluctuation, we performed simultaneous EEGs and functional magnetic resonance imaging recordings in human subjects during a resting state and explored the dynamic relationship between alpha power fluctuation and blood oxygenation level-dependent (BOLD signals of the brain. Based on the frequency characteristics of the alpha power time series (APTS during 20-minute EEG recordings, we divided the APTS into two components: fast fluctuation (0.04-0.167 Hz and slow fluctuation (0-0.04 Hz. Analysis of the correlation between the MRI signal and each component revealed that the slow fluctuation component of alpha power was positively correlated with BOLD signal changes in the brain stem and the medial part of the thalamus and anterior cingulate cortex, while the fast fluctuation component was correlated with the lateral part of the thalamus and the anterior cingulate cortex, but not the brain stem. In summary, these data suggest that different subcortical structures contribute to slow and fast modulations of alpha spectra on brain EEG.

  14. Proteasome Activity Is Affected by Fluctuations in Insulin-Degrading Enzyme Distribution.

    Sbardella, Diego; Tundo, Grazia Raffaella; Sciandra, Francesca; Bozzi, Manuela; Gioia, Magda; Ciaccio, Chiara; Tarantino, Umberto; Brancaccio, Andrea; Coletta, Massimo; Marini, Stefano

    2015-01-01

    Insulin-Degrading-Enzyme (IDE) is a Zn2+-dependent peptidase highly conserved throughout evolution and ubiquitously distributed in mammalian tissues wherein it displays a prevalent cytosolic localization. We have recently demonstrated a novel Heat Shock Protein-like behaviour of IDE and its association with the 26S proteasome. In the present study, we examine the mechanistic and molecular features of IDE-26S proteasome interaction in a cell experimental model, extending the investigation also to the effect of IDE on the enzymatic activities of the 26S proteasome. Further, kinetic investigations indicate that the 26S proteasome activity undergoes a functional modulation by IDE through an extra-catalytic mechanism. The IDE-26S proteasome interaction was analyzed during the Heat Shock Response and we report novel findings on IDE intracellular distribution that might be of critical relevance for cell metabolism.

  15. Proteasome Activity Is Affected by Fluctuations in Insulin-Degrading Enzyme Distribution.

    Diego Sbardella

    Full Text Available Insulin-Degrading-Enzyme (IDE is a Zn2+-dependent peptidase highly conserved throughout evolution and ubiquitously distributed in mammalian tissues wherein it displays a prevalent cytosolic localization. We have recently demonstrated a novel Heat Shock Protein-like behaviour of IDE and its association with the 26S proteasome. In the present study, we examine the mechanistic and molecular features of IDE-26S proteasome interaction in a cell experimental model, extending the investigation also to the effect of IDE on the enzymatic activities of the 26S proteasome. Further, kinetic investigations indicate that the 26S proteasome activity undergoes a functional modulation by IDE through an extra-catalytic mechanism. The IDE-26S proteasome interaction was analyzed during the Heat Shock Response and we report novel findings on IDE intracellular distribution that might be of critical relevance for cell metabolism.

  16. Multichannel Detrended Fluctuation Analysis Reveals Synchronized Patterns of Spontaneous Spinal Activity in Anesthetized Cats

    Erika E Rodríguez; Enrique Hernández-Lemus; Itzá-Ortiz, Benjamín A.; Ismael Jiménez; Pablo Rudomín

    2011-01-01

    The analysis of the interaction and synchronization of relatively large ensembles of neurons is fundamental for the understanding of complex functions of the nervous system. It is known that the temporal synchronization of neural ensembles is involved in the generation of specific motor, sensory or cognitive processes. Also, the intersegmental coherence of spinal spontaneous activity may indicate the existence of synaptic neural pathways between different pairs of lumbar segments. In this stu...

  17. Systematic mining of analog series with related core structures in multi-target activity space.

    Gupta-Ostermann, Disha; Hu, Ye; Bajorath, Jürgen

    2013-08-01

    We have aimed to systematically extract analog series with related core structures from multi-target activity space to explore target promiscuity of closely related analogous. Therefore, a previously introduced SAR matrix structure was adapted and further extended for large-scale data mining. These matrices organize analog series with related yet distinct core structures in a consistent manner. High-confidence compound activity data yielded more than 2,300 non-redundant matrices capturing 5,821 analog series that included 4,288 series with multi-target and 735 series with multi-family activities. Many matrices captured more than three analog series with activity against more than five targets. The matrices revealed a variety of promiscuity patterns. Compound series matrices also contain virtual compounds, which provide suggestions for compound design focusing on desired activity profiles.

  18. In vivo determination of fluctuating forces during endosome trafficking using a combination of active and passive microrheology.

    Damien Robert

    Full Text Available BACKGROUND: Regulation of intracellular trafficking is a central issue in cell biology. The forces acting on intracellular vesicles (endosomes can be assessed in living cells by using a combination of active and passive microrheology. METHODOLOGY/PRINCIPAL FINDINGS: This dual approach is based on endosome labeling with magnetic nanoparticles. The resulting magnetic endosomes act both as probes that can be manipulated with external magnetic fields to infer the viscoelastic modulus of their surrounding microenvironment, and as biological vehicles that are trafficked along the microtubule network by means of forces generated by molecular motors. The intracellular viscoelastic modulus exhibits power law dependence with frequency, which is microtubule and actin-dependent. The mean square displacements of endosomes do not follow the predictions of the fluctuation-dissipation theorem, which offers evidence for active force generation. Microtubule disruption brings the intracellular medium closer to thermal equilibrium: active forces acting on the endosomes depend on microtubule-associated motors. The power spectra of these active forces, deduced through the use of a generalized Langevin equation, show a power law decrease with frequency and reveal an actin-dependent persistence of the force with time. Experimental spectra have been reproduced by a simple model consisting in a series of force steps power-law distributed in time. This model enlightens the role of the cytoskeleton dependent force exerted on endosomes to perform intracellular trafficking. CONCLUSIONS/SIGNIFICANCE: In this work, the influence of cytoskeleton components and molecular motors on intracellular viscoelasticity and transport is addressed. The use of an original probe, the magnetic endosome, allows retrieving the power spectrum of active forces on these organelles thanks to interrelated active and passive measures. Finally a computational model gives estimates of the force itself

  19. Core-shell column Tanaka characterization and additional tests using active pharmaceutical ingredients.

    Ludvigsson, Jufang Wu; Karlsson, Anders; Kjellberg, Viktor

    2016-12-01

    In the last decade, core-shell particles have gained more and more attention in fast liquid chromatography separations due to their comparable performance with fully porous sub-2 μm particles and their significantly lower back pressure. Core-shell particles are made of a solid core surrounded by a shell of classic fully porous material. To embrace the developed core-shell column market and use these columns in pharmaceutical analytical applications, 17 core-shell C18 columns purchased from various vendors with various dimensions (50 mm × 2.1 mm to 100 mm × 3 mm) and particle sizes (1.6-2.7 μm) were characterized using Tanaka test protocols. Furthermore, four selected active pharmaceutical ingredients were chosen as test probes to investigate the batch to batch reproducibility for core-shell columns of particle size 2.6-2.7 μm, with dimension of 100 × 3 mm and columns of particle size 1.6 μm, with dimension 100 × 2.1 mm under isocratic elution. Columns of particle size 2.6-2.7 μm were also tested under gradient elution conditions. To confirm the claimed comparable efficiency of 2.6 μm core-shell particles as sub-2 μm fully porous particles, column performances of the selected core-shell columns were compared with BEH C18 , 1.7 μm, a fully porous column material as well.

  20. Non-equilibrium fluctuations of a semi-flexible filament driven by active cross-linkers

    Weber, Ines; Schehr, Grégory; Santen, Ludger

    2016-01-01

    The cytoskeleton is an inhomogeneous network of semi-flexible filaments, which are involved in a wide variety of active biological processes. Although the cytoskeletal filaments can be very stiff and embedded in a dense and cross-linked network, it has been shown that, in cells, they typically exhibit significant bending on all length scales. In this work we propose a model of a semi-flexible filament deformed by different types of cross-linkers for which one can compute and investigate the bending spectrum. Our model allows to couple the evolution of the deformation of the semi-flexible polymer with the stochastic dynamics of linkers which exert transversal forces onto the filament. We observe a $q^{-2}$ dependence of the bending spectrum for some biologically relevant parameters and in a certain range of wavenumbers $q$. However, generically, the spatially localized forcing and the non-thermal dynamics both introduce deviations from the thermal-like $q^{-2}$ spectrum.

  1. Dye-Sensitized Core/Active Shell Upconversion Nanoparticles for Optogenetics and Bioimaging Applications

    Wu, Xiang; Zhang, Yuanwei; Takle, Kendra; Bilsel, Osman; Li, Zhanjun; Lee, Hyungseok; Zhang, Zijiao; Li, Dongsheng; Fan, Wei; Duan, Chunying; Chan, Emory M.; Lois, Carlos; Xiang, Yang; Han, Gang

    2016-01-26

    Near Infrared (NIR) dye-sensitized upconversion nanoparticles (UCNPs) have recently been proposed in order to broaden the absorption range and to boost upconversion efficiency. However, implementing this strategy has been limited only to bare core UCNP structures that are faintly luminescent. Herein, we report on an approach to achieve significantly enhanced upconversion luminescence in dye-sensitized core-active shell UCNPs with a broadened absorption range via the doping of ytterbium ions in the UCNP shell in order to bridge the energy transfer from the dye to the UCNP core. As a result, we have been able to synergize the two most practical upconversion booster effectors (dye-sensitizing and core/shell enhancement). The absolute quantum yield of our dye-sensitized core/active shell UCNPs at 800 nm was determined to be ~6% at 2 W/cm2, about 33 times larger than the highest value reported to date for existing 800 nm excitable UCNPs. Moreover, for the first time, by using dye-sensitized core/active shell UCNP embedded poly(methyl methacrylate) polymer implantable systems, we successfully shifted the optogenetic neuron excitation window to a wavelength that is compatible with deep tissue penetrable near the infrared wavelength at 800 nm. Finally, amphiphilic triblock copolymer, Pluronic F127 coatings permit the transfer of hydrophobic UCNPs into water, resulting in water-soluble nanoparticles with well-preserved optical property in aqueous solution. We believe that this research offers a new solution to enhance upconversion efficiency for photonic and biophotonic purposes and opens up new opportunities to use UCNPs as a NIR relay for optogenetic applications.

  2. Study of the spatial dependence of neutronic flow oscillations caused by fluctuations thermohydraulics at the entrance of the core of a reactor PWR; Estudio de la dependencia espacial de las oscilaciones de flujo neutronico causadas por flucturaciones termohidraulicas a la entrada del nucleo de un reactor PWR

    Bermejo, J. A.; Lopez, A.; Ortego, A.

    2014-07-01

    It presents a theoretical study on spatial dependence of flow oscillations neutronic caused by thermal hydraulics fluctuations at the entrance of the core of a PWR reactor. To simulate, with SIMULATE code - 3K different fluctuations thermohydraulics at the entrance to the core and the spatial dependence of the oscillations and is analyzed neutronic flow obtained at locations of neutron detectors. the work It is part of the r and d program initiated in CNAT to investigate the phenomenon of the noise neutronic. (Author)

  3. The response of short-scale density fluctuations to the activity of beta-induced Alfvén eigenmodes during strong tearing modes on EAST tokamak

    Cao, G. M.; Li, Y. D.; Li, Q.; Sun, P. J.; Wu, G. J.; Hu, L. Q.; the EAST Team

    2015-08-01

    Beta-induced Alfvén eigenmodes (BAEs) during strong tearing modes (TMs) have been frequently observed in fast-electron plasmas of EAST tokamak. The dynamics of the short-scale ({k}\\perp {ρ }s~{1.5-4.3}) density fluctuations during the activity of BAEs with strong TMs has been preliminarily investigated by a tangential CO2 laser collective scattering system. The results suggest the active, but different, response of short-scale density fluctuations to the TMs and BAEs. In the low-frequency (0-10 kHz) part of density fluctuations, there are harmonic oscillations totally corresponding to those of TMs. In the medium-high frequency (10-250 kHz) part of density fluctuations, with the appearance of the BAEs, the medium-high frequency density fluctuations begin to be dominated by several quasi-coherent (QC) modes, and the frequencies of the QC modes seem to be related to the changes of both TMs and BAEs. These results would shed some light on the understanding of the multi-scale interaction physics.

  4. Beat-induced fluctuations in auditory cortical beta-band activity: Using EEG to measure age-related changes

    Laura K Cirelli

    2014-07-01

    Full Text Available People readily extract regularity in rhythmic auditory patterns, enabling prediction of the onset of the next beat. Recent magnetoencephalography (MEG research suggests that such prediction is reflected by the entrainment of oscillatory networks in the brain to the tempo of the sequence. In particular, induced beta-band oscillatory activity from auditory cortex decreases after each beat onset and rebounds prior to the onset of the next beat across tempi in a predictive manner. The objective of the present study was to examine the development of such oscillatory activity by comparing electroencephalography (EEG measures of beta-band fluctuations in 7-year-old children to adults. EEG was recorded while participants listened passively to isochronous tone sequences at three tempi (390, 585, and 780ms for onset-to-onset interval. In adults, induced power in the high beta-band (20-25 Hz decreased after each tone onset and rebounded prior to the onset of the next tone across tempo conditions, consistent with MEG findings. In children, a similar pattern was measured in the two slower tempo conditions, but was weaker in the fastest condition. The results indicate that the beta-band timing network works similarly in children, although there are age-related changes in consistency and the tempo range over which it operates.

  5. Concurrent sympathetic activation and vagal withdrawal in hyperthyroidism: Evidence from detrended fluctuation analysis of heart rate variability

    Chen, Jin-Long; Shiau, Yuo-Hsien; Tseng, Yin-Jiun; Chiu, Hung-Wen; Hsiao, Tzu-Chien; Wessel, Niels; Kurths, Jürgen; Chu, Woei-Chyn

    2010-05-01

    Despite many previous studies on the association between hyperthyroidism and the hyperadrenergic state, controversies still exist. Detrended fluctuation analysis (DFA) is a well recognized method in the nonlinear analysis of heart rate variability (HRV), and it has physiological significance related to the autonomic nervous system. In particular, an increased short-term scaling exponent α1 calculated from DFA is associated with both increased sympathetic activity and decreased vagal activity. No study has investigated the DFA of HRV in hyperthyroidism. This study was designed to assess the sympathovagal balance in hyperthyroidism. We performed the DFA along with the linear analysis of HRV in 36 hyperthyroid Graves’ disease patients (32 females and 4 males; age 30 ± 1 years, means ± SE) and 36 normal controls matched by sex, age and body mass index. Compared with the normal controls, the hyperthyroid patients revealed a significant increase ( Phyperthyroid 1.28±0.04 versus control 0.91±0.02), long-term scaling exponent α2 (1.05±0.02 versus 0.90±0.01), overall scaling exponent α (1.11±0.02 versus 0.89±0.01), low frequency power in normalized units (LF%) and the ratio of low frequency power to high frequency power (LF/HF); and a significant decrease ( Phyperthyroidism is characterized by concurrent sympathetic activation and vagal withdrawal. This sympathovagal imbalance state in hyperthyroidism helps to explain the higher prevalence of atrial fibrillation and exercise intolerance among hyperthyroid patients.

  6. Spontaneous pre-stimulus fluctuations in the activity of right fronto-parietal areas influence inhibitory control performance

    Camille F. Chavan

    2013-06-01

    Full Text Available Inhibitory control refers to the ability to suppress planned or ongoing cognitive or motor processes. Electrophysiological indices of inhibitory control failure have been found to manifest even before the presentation of the stimuli triggering the inhibition, suggesting that pre-stimulus brain-states modulate inhibition performance. However, previous electrophysiological investigations on the state-dependency of inhibitory control were based on averaged event-related potentials, a method eliminating the variability in the ongoing brain activity not time-locked to the event of interest. These studies thus left unresolved whether spontaneous variations in the brain-state immediately preceding unpredictable inhibition-triggering stimuli also influence inhibitory control performance.To address this question, we applied single-trial EEG topographic analyses on the time interval immediately preceding NoGo stimuli in conditions where the responses to NoGo trials were correctly inhibited (correct rejection vs. committed (false alarms during an auditory spatial Go/NoGo task.We found a specific configuration of the EEG voltage field manifesting more frequently before correctly inhibited responses to NoGo stimuli than before false alarms. There was no evidence for an EEG topography occurring more frequently before false alarms than before correct rejections. The visualization of distributed electrical source estimations of the EEG topography preceding successful response inhibition suggested that it resulted from the activity of a right fronto-parietal brain network.Our results suggest that the fluctuations in the ongoing brain activity immediately preceding stimulus presentation contribute to the behavioral outcomes during an inhibitory control task. Our results further suggest that the state-dependency of sensory-cognitive processing might not only concern perceptual processes, but also high-order, top-down inhibitory control mechanisms.

  7. Fine-Scale Fluctuations in the Corona Observed with Hi-C

    Winebarger, Amy; Schuler, Timothy

    2013-01-01

    The High Resolution Coronal Imager(HiC) flew aboard a NASA sounding rocket on 2012 July11 and captured roughly 345 s of high spatial and temporal resolution images of the solar corona in a narrowband 193 Angstrom channel. We have analyzed the fluctuations in intensity of Active Region11520.We selected events based on a lifetime greater than 11s (twoHiC frames)and intensities greater than a threshold determined from the average background intensity in a pixel and the photon and electronic noise. We find fluctuations occurring down to the smallest timescale(11s).Typical intensity fluctuations are 20% background intensity, while some events peaka t100%the background intensity.Generally the fluctuations are clustered in solar structures, particularly the moss.We interpret the fluctuations in the moss as indicative of heating events. We use the observed events to model the active region core.

  8. 75 FR 8239 - Federal Home Loan Bank Housing Associates, Core Mission Activities and Standby Letters of Credit

    2010-02-24

    ... 2590-AA33 Federal Home Loan Bank Housing Associates, Core Mission Activities and Standby Letters of... Home Loan Bank (Bank) housing associates, the Banks' core mission activities, and Bank issuance of... collection contained in the current Federal Home Loan Bank Housing Associates regulation, has been...

  9. Core muscle activity in a series of balance exercises with different stability conditions.

    Calatayud, Joaquin; Borreani, Sebastien; Martin, Julio; Martin, Fernando; Flandez, Jorge; Colado, Juan C

    2015-07-01

    Literature that provides progression models based on core muscle activity and postural manipulations is scarce. The purpose of this study was to investigate the core muscle activity in a series of balance exercises with different stability levels and additional elastic resistance. A descriptive study of electromyography (EMG) was performed with forty-four healthy subjects that completed 12 exercises in a random order. Exercises were performed unipedally or bipedally with or without elastic tubing as resistance on various unstable (uncontrolled multiaxial and uniaxial movement) and stable surfaces. Surface EMG on the lumbar multífidus spinae (LM), thoracic multífidus spinae (TM), lumbar erector spinae (LE), thoracic erector spinae (TE) and gluteus maximus (GM), on the dominant side of the body were collected to quantify the amount of muscle activity and were expressed as a % of the maximum voluntary isometric contraction (MVIC). Significant differences (pcore muscle activity. An adequate exercise progression based on global core EMG could start with seated positions, progressing to bipedal standing stance (i.e., from either multiaxial or stable surface to uniaxial surface). Following this, unipedal standing positions may be performed (i.e., from either multiaxial or stable surface to uniaxial surface) and finally, elastic resistance must be added in order to increase EMG levels (i.e., from stable surface progressing to any of the used unstable surfaces).

  10. Biodegradable core-shell carriers for simultaneous encapsulation of synergistic actives.

    Windbergs, Maike; Zhao, Yuanjin; Heyman, John; Weitz, David A

    2013-05-29

    Simultaneous encapsulation of multiple active substances in a single carrier is essential for therapeutic applications of synergistic combinations of drugs. However, traditional carrier systems often lack efficient encapsulation and release of incorporated substances, particularly when combinations of drugs must be released in concentrations of a prescribed ratio. We present a novel biodegradable core-shell carrier system fabricated in a one-step, solvent-free process on a microfluidic chip; a hydrophilic active (doxorubicin hydrochloride) is encapsulated in the aqueous core, while a hydrophobic active (paclitaxel) is encapsulated in the solid shell. Particle size and composition can be precisely controlled, and core and shell can be individually loaded with very high efficiency. Drug-loaded particles can be dried and stored as a powder. We demonstrate the efficacy of this system through the simultaneous encapsulation and controlled release of two synergistic anticancer drugs using two cancer-derived cell lines. This solvent-free platform technology is also of high potential value for encapsulation of other active ingredients and chemical reagents.

  11. Surface-engineered core-shell nano-size ferrites and their antimicrobial activity

    Baraliya, Jagdish D., E-mail: jdbaraliya@yahoo.co.in; Joshi, Hiren H., E-mail: jdbaraliya@yahoo.co.in [Department of Physics, Saurashtra University, Rajkot - 360 005, Gujarat (India)

    2014-04-24

    We report the results of biological study on core-shell structured MFe{sub 2}O{sub 4} (where M = Co, Mn, Ni) nanoparticles and influence of silica- DEG dual coating on their antimicrobial activity. Spherical MFe{sub 2}O{sub 4} nanoparticles were prepared via a Co-precipitation method. The microstructures and morphologies of these nanoparticles were studied by x-ray diffraction and FTIR. The antimicrobial activity study carried out in nutrient agar medium with addition of antimicrobial synthesis compound which is tested for its activity against different types of bacteria.

  12. Ice cores

    Svensson, Anders

    2014-01-01

    Ice cores from Antarctica, from Greenland, and from a number of smaller glaciers around the world yield a wealth of information on past climates and environments. Ice cores offer unique records on past temperatures, atmospheric composition (including greenhouse gases), volcanism, solar activity......, dustiness, and biomass burning, among others. In Antarctica, ice cores extend back more than 800,000 years before present (Jouzel et al. 2007), whereas. Greenland ice cores cover the last 130,000 years...

  13. Preparation, characterization and photocatalytic activity of TiO2/polyaniline core-shell nanocomposite

    Ali Olad; Sepideh Behboudi; Ali Akbar Entezami

    2012-10-01

    Polyaniline (PANI) as a promising conducting polymer has been used to prepare polyaniline/TiO2 (PANI/TiO2) nanocomposite with core-shell structure as photocatalyst. Titanium dioxide (TiO2) nanoparticles with an average crystal size of 21 nm were encapsulated by PANI via the in situ polymerization of aniline on the surface of TiO2 nanoparticles. FT–IR, UV-Vis-NIR, XRD, SEM and TEM techniques were used to characterize the PANI/TiO2 core-shell nanocomposite. Photocatalytic activity of PANI/TiO2 nanocomposite was investigated under both UV and visible light irradiations and compared with unmodified TiO2 nanoparticles. Results indicated deposition of PANI on the surface of TiO2 nanoparticles which improved the photocatalytic activity of pristine TiO2 nanoparticles.

  14. 9,400 years of cosmic radiation and solar activity from ice cores and tree rings.

    Steinhilber, Friedhelm; Abreu, Jose A; Beer, Jürg; Brunner, Irene; Christl, Marcus; Fischer, Hubertus; Heikkilä, Ulla; Kubik, Peter W; Mann, Mathias; McCracken, Ken G; Miller, Heinrich; Miyahara, Hiroko; Oerter, Hans; Wilhelms, Frank

    2012-04-17

    Understanding the temporal variation of cosmic radiation and solar activity during the Holocene is essential for studies of the solar-terrestrial relationship. Cosmic-ray produced radionuclides, such as (10)Be and (14)C which are stored in polar ice cores and tree rings, offer the unique opportunity to reconstruct the history of cosmic radiation and solar activity over many millennia. Although records from different archives basically agree, they also show some deviations during certain periods. So far most reconstructions were based on only one single radionuclide record, which makes detection and correction of these deviations impossible. Here we combine different (10)Be ice core records from Greenland and Antarctica with the global (14)C tree ring record using principal component analysis. This approach is only possible due to a new high-resolution (10)Be record from Dronning Maud Land obtained within the European Project for Ice Coring in Antarctica in Antarctica. The new cosmic radiation record enables us to derive total solar irradiance, which is then used as a proxy of solar activity to identify the solar imprint in an Asian climate record. Though generally the agreement between solar forcing and Asian climate is good, there are also periods without any coherence, pointing to other forcings like volcanoes and greenhouse gases and their corresponding feedbacks. The newly derived records have the potential to improve our understanding of the solar dynamics and to quantify the solar influence on climate.

  15. (129)I record of nuclear activities in marine sediment core from Jiaozhou Bay in China.

    Fan, Yukun; Hou, Xiaolin; Zhou, Weijian; Liu, Guangshan

    2016-04-01

    Iodine-129 has been used as a powerful tool for environmental tracing of human nuclear activities. In this work, a sediment core collected from Jiaozhou Bay, the east coast of China, in 2002 was analyzed for (129)I to investigate the influence of human nuclear activities in this region. Significantly enhanced (129)I level was observed in upper 70 cm of the sediment core, with peak values in the layer corresponding to 1957, 1964, 1974, 1986, and after 1990. The sources of (129)I and corresponding transport processes in this region are discussed, including nuclear weapons testing at the Pacific Proving Grounds, global fallout from a large numbers of nuclear weapon tests in 1963, the climax of Chinese nuclear weapons testing in the early 1970s, the Chernobyl accident in 1986, and long-distance dispersion of European reprocessing derived (129)I. The very well (129)I records of different human nuclear activities in the sediment core illustrate the potential application of (129)I in constraining ages and sedimentation rates of the recent sediment. The releases of (129)I from the European nuclear fuel reprocessing plants at La Hague (France) and Sellafield (UK) were found to dominate the inventory of (129)I in the Chinese sediments after 1990, not only the directly atmospheric releases of these reprocessing plants, but also re-emission of marine discharged (129)I of these reprocessing plants in the highly contaminated European seas.

  16. Porous TiO2-coated Magnetic Core-Shell Nanocomposites: Preparation and Enhanced Photocatalytic Activity

    LIU Hongfei; JI Shengfu; ZHENG Yuanyuan; LI Ming; YANG Hao

    2013-01-01

    The core-shell structured TiO2/SiO2@Fe3O4 photocatalysts were prepared using Fe3O4 as magnetic core,tetraethoxysilane (TEOS) as silica source and tetrabutyl titanate (TBOT) as titanium sources.The as-obtained structure was composed of a SiO2@Fe3O4 core and a porous TiO2 shell.The diameter of SiO2@Fe3O4 core was about 205 nm with thickness of porous TiO2 of about 5-6 nm.The 9%TiO2/6% SiO2@Fe3O4 microspheres possess the highest BET surface area and the BJH pore volume,which are 373.5 m2·g-1 and 0.28 cm3·g-1,respectively.The 9%TiO2/6%SiO2@Fe3O4 photocatalyst exhibited an excellent performance for the degradation of methyl orange and methylene blue dyes.Two different dyes were completely decolorized in 60 rain under UV irradiation.The photocatalytic activity and the amount of catalyst were almost not decrease after recycling for 6 times by using external magnetic field.

  17. Magnetite/poly(alkylcyanoacrylate) (core/shell) nanoparticles as 5-Fluorouracil delivery systems for active targeting.

    Arias, José L; Gallardo, Visitación; Ruiz, M A Adolfina; Delgado, Angel V

    2008-05-01

    In this article, a reproducible emulsion polymerization process is described to prepare core/shell colloidal nanospheres, loaded with 5-Fluorouracil, and consisting of a magnetic core (magnetite) and a biodegradable polymeric shell [poly(ethyl-2-cyanoacrylate), poly(butylcyanoacrylate), poly(hexylcyanoacrylate), or poly(octylcyanoacrylate)]. The heterogeneous structure of these carriers can confer them both the possibility of being used as drug delivery systems and the responsiveness to external magnetic fields, allowing an active drug targeting without a concurrent systemic distribution. Zeta potential determinations as a function of ionic strength showed that the surface behaviour of the core/shell particles is similar to that of pure cyanoacrylate particles. The first magnetization curve of both magnetite and magnetite/polymer particles demonstrated that the polymer shell reduces the magnetic responsiveness of the particles, but keeps unchanged their ferrimagnetic character. Two drug loading mechanisms were studied: absorption or entrapment in the polymeric network, and surface adsorption. We found that the acidity of the medium had significant effects on the drug absorption per unit mass of polymer, and needs to be controlled to avoid formation of macroaggregates and to reach significant 5-Fluorouracil absorption. The type of polymer and the drug concentration are also main factors determining the drug incorporation to the core/shell particles. 5-Fluorouracil release evaluations showed a biphasic profile affected by the type of polymeric shell, the type of drug incorporation and the amount of drug loaded.

  18. Human and climate impacts on Holocene fire activity recorded in polar and mountain ice cores

    Kehrwald, Natalie; Zennaro, Piero; Kirchgeorg, Torben; Li, Quanlian; Wang, Ninglian; Power, Mitchell; Zangrando, Roberta; Gabrielli, Paolo; Thompson, Lonnie; Gambaro, Andrea; Barbante, Carlo

    2014-05-01

    Fire is one of the major influences of biogeochemical change on local to hemispheric scales through emitting greenhouse gases, altering atmospheric chemistry, and changing primary productivity. Levoglucosan (1,6-anhydro-β-D-glucopyranose) is a specific molecular that can only be produced by cellulose burning at temperatures > 300°C, comprises a major component of smoke plumes, and can be transported across > 1000 km distances. Levoglucosan is deposited on and archived in glaciers over glacial interglacial cycles resulting in pyrochemical evidence for exploring interactions between fire, climate and human activity. Ice core records provide records of past biomass burning from regions of the world with limited paleofire data including polar and low-latitude, high-altitude regions. Here, we present Holocene fire activity records from the NEEM, Greenland (77° 27'N; 51° 3'W; 2454 masl), EPICA Dome C, Antarctica (75° 06'S; 123° 21'E; 3233 masl), Kilimanjaro, Tanzania (3° 05'S, 21.2° E, 5893 masl) and the Muztagh, China (87.17° E; 36.35° N; 5780 masl ice cores. The NEEM ice core reflects boreal fire activity from both North American and Eurasian sources. Temperature is the dominant control of NEEM levoglucosan flux over decadal to millennial time scales, while droughts influence fire activity over sub-decadal timescales. Our results demonstrate the prominence of Siberian fire sources during intense multiannual droughts. Unlike the NEEM core, which incorporates the largest land masses in the world as potential fire sources, EPICA Dome C is located far from any possible fire source. However, EPICA Dome C levoglucosan concentrations are consistently above detection limits and demonstrate a substantial 1000-fold increase in fire activity beginning approximately 800 years ago. This significant and sustained increase coincides with Maori arrival and dispersal in New Zealand augmented by later European arrival in Australia. The EPICA Dome C levoglucosan profile is

  19. Cereblon inhibits proteasome activity by binding to the 20S core proteasome subunit beta type 4.

    Lee, Kwang Min; Lee, Jongwon; Park, Chul-Seung

    2012-10-26

    In humans, mutations in the gene encoding cereblon (CRBN) are associated with mental retardation. Although CRBN has been investigated in several cellular contexts, its function remains unclear. Here, we demonstrate that CRBN plays a role in regulating the ubiquitin-proteasome system (UPS). Heterologous expression of CRBN inhibited proteasome activity in a human neuroblastoma cell line. Furthermore, proteasome subunit beta type 4 (PSMB4), the β7 subunit of the 20S core complex, was identified as a direct binding partner of CRBN. These findings suggest that CRBN may modulate proteasome activity by directly interacting with the β7 subunit.

  20. Sustained antioxidant activity of quercetin-loaded lipid-core nanocapsules.

    Weiss-Angeli, Valéria; Poletto, Fernanda S; de Marco, Samuel L; Salvador, Miriam; da Silveira, Nádya P; Guterres, Sílvia S; Pohlmann, Adriana R

    2012-03-01

    Lipid-core nanocapsules (LNC) are vesicular nanocarriers prepared by solvent displacement. LNC have been previously prepared using medium-chain triglyceride and sorbitan monostearate as liquid and solid lipophilic components dispersed in the core, surrounded by poly(epsilon-caprolactone) (PCL). Our objective was to investigate the antioxidant activity of LNC containing quercetin (QUE), a radical scavenger, prepared with octyl methoxycinnamate and sorbitan monostearate as lipophilic core components and PCL as the polymer wall. We selected Saccharomyces cerevisae cells as the proposed biological model. QUE-LNC presented z-average diameter of 212 nm, pH of 5.51 and zeta potential of -11 mV. Multiple light scattering analysis (TurbiscanLab) showed a photon path length of 172 microm. Furthermore, a validated turbidimetric study determined that the density of particles in suspension was 1.66 x 10(13). DSC analysis showed that the melting temperature of PCL shifted to lower values when in contact with octyl methoxycinnamate indicating a molecular interaction. After 1 h (7 h), the QUE-LNC formulation and QUE solution incubated with H2O2 showed cell survival of 84.4% (87.7%) and 65.6% (7.3%), respectively. After 35 h of incubation, cell survival was 31.7% and 0.9%, respectively. The QUE-LNC showed sustained antioxidant activity and potential as a nanostructured material to formulate final products.

  1. The status of HEU to LEU core conversion activities at the Jamaica SLOWPOKE

    Preston, J.; Grant, C., E-mail: john.preston@uwimona.edu.jm [Univ. of the West Indies, Mona Campus, International Centre for Environmental and Nuclear Sciences, Mona (Jamaica)

    2012-12-15

    The SLOWPOKE reactor in Jamaica has been operated by the International Centre for Environmental and Nuclear Sciences, University of the West Indies since 1984, mainly for the purpose of Neutron Activation Analysis. The HEU core with current utilization has another 14 years of operation, before the addition of a large beryllium annulus would be required to further extend the life-time by 15 years. However, in keeping with the spirit of the Reduced Enrichment for Research and Test Reactors (RERTR) program, the decision was taken in 2003 to convert the core from HEU to LEU, in line with those at the Ecole Polytechnic and RMC SLOWPOKE facilities. This paper reports on the current status of the conversion activities, including key fuel manufacture and regulatory issues, which have seen substantial progress during the last year. A timetable for the complete process is given, and provided that the fuel fabrication can be completed in the estimated 18 months, the core conversion should be accomplished by the end of 2014. (author)

  2. The status of HEU and LEU core conversion activities at the Jamaica SLOWPOKE

    Preston, J.; Grant, C., E-mail: john.preston@uwimona.edu.jm [Univ. of the West Indies, Mona Campus, International Centre for Environmental and Nuclear Sciences, Kingston (Jamaica)

    2013-07-01

    The SLOWPOKE reactor in Jamaica has been operated by the International Centre for Environmental and Nuclear Sciences, University of the West Indies since 1984, mainly for the purpose of Neutron Activation Analysis. The HEU core with current utilization has another 14 years of operation, before the addition of a large beryllium annulus would be required to further extend the life-time by 15 years. However, in keeping with the spirit of the Reduced Enrichment for Research and Test Reactors (RERTR) program, the decision was taken in 2003 to convert the core from HEU to LEU, inline with those at the Ecole Polytechnic and RMC SLOWPOKE facilities. This paper reports on the current status of the conversion activities, including key fuel manufacture and regulatory issues, which have seen substantial progress during the last year. A timetable for the complete process is given, and provided that the fuel fabrication can be completed in the estimated 18 months, the core conversion should be accomplished by the end of 2014. (author)

  3. Enhanced photocatalytic activity of C@ZnO core-shell nanostructures and its photoluminescence property

    Chen, Tao; Yu, Shanwen; Fang, Xiaoxin; Huang, Honghong; Li, Lun; Wang, Xiuyuan; Wang, Huihu

    2016-12-01

    An ultrathin layer of amorphous carbon coated C@ZnO core-shell nanostructures were synthesized via a facile hydrothermal carbonization process using glucose as precursor in this work. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and diffuse reflectance UV-vis spectroscopy (DRS) were used for the characterization of as-prepared samples. Photoluminescence (PL) properties of C@ZnO samples were investigated using PL spectroscopy. The microstructure analysis results show that the glucose content has a great influence on the size, morphology, crystallinity and surface chemical states of C@ZnO nanostructures. Moreover, the as-prepared C@ZnO core-shell nanostructures exhibit the enhanced photocatalytic activity and good photostability for methyl orange dye degradation due to its high adsorption ability and its improved optical characteristics.

  4. Lattice-strain control of the activity in dealloyed core-shell fuel cell catalysts.

    Strasser, Peter; Koh, Shirlaine; Anniyev, Toyli; Greeley, Jeff; More, Karren; Yu, Chengfei; Liu, Zengcai; Kaya, Sarp; Nordlund, Dennis; Ogasawara, Hirohito; Toney, Michael F; Nilsson, Anders

    2010-06-01

    Electrocatalysis will play a key role in future energy conversion and storage technologies, such as water electrolysers, fuel cells and metal-air batteries. Molecular interactions between chemical reactants and the catalytic surface control the activity and efficiency, and hence need to be optimized; however, generalized experimental strategies to do so are scarce. Here we show how lattice strain can be used experimentally to tune the catalytic activity of dealloyed bimetallic nanoparticles for the oxygen-reduction reaction, a key barrier to the application of fuel cells and metal-air batteries. We demonstrate the core-shell structure of the catalyst and clarify the mechanistic origin of its activity. The platinum-rich shell exhibits compressive strain, which results in a shift of the electronic band structure of platinum and weakening chemisorption of oxygenated species. We combine synthesis, measurements and an understanding of strain from theory to generate a reactivity-strain relationship that provides guidelines for tuning electrocatalytic activity.

  5. Polymer-inorganic core-shell nanofibers by electrospinning and atomic layer deposition: flexible nylon-ZnO core-shell nanofiber mats and their photocatalytic activity.

    Kayaci, Fatma; Ozgit-Akgun, Cagla; Donmez, Inci; Biyikli, Necmi; Uyar, Tamer

    2012-11-01

    Polymer-inorganic core-shell nanofibers were produced by two-step approach; electrospinning and atomic layer deposition (ALD). First, nylon 6,6 (polymeric core) nanofibers were obtained by electrospinning, and then zinc oxide (ZnO) (inorganic shell) with precise thickness control was deposited onto electrospun nylon 6,6 nanofibers using ALD technique. The bead-free and uniform nylon 6,6 nanofibers having different average fiber diameters (∼80, ∼240 and ∼650 nm) were achieved by using two different solvent systems and polymer concentrations. ZnO layer about 90 nm, having uniform thickness around the fiber structure, was successfully deposited onto the nylon 6,6 nanofibers. Because of the low deposition temperature utilized (200 °C), ALD process did not deform the polymeric fiber structure, and highly conformal ZnO layer with precise thickness and composition over a large scale were accomplished regardless of the differences in fiber diameters. ZnO shell layer was found to have a polycrystalline nature with hexagonal wurtzite structure. The core-shell nylon 6,6-ZnO nanofiber mats were flexible because of the polymeric core component. Photocatalytic activity of the core-shell nylon 6,6-ZnO nanofiber mats were tested by following the photocatalytic decomposition of rhodamine-B dye. The nylon 6,6-ZnO nanofiber mat, having thinner fiber diameter, has shown better photocatalytic efficiency due to higher surface area of this sample. These nylon 6,6-ZnO nanofiber mats have also shown structural stability and kept their photocatalytic activity for the second cycle test. Our findings suggest that core-shell nylon 6,6-ZnO nanofiber mat can be a very good candidate as a filter material for water purification and organic waste treatment because of their photocatalytic properties along with structural flexibility and stability.

  6. Rapid core field variations during the satellite era: Investigations using stochastic process based field models

    Finlay, Chris; Olsen, Nils; Gillet, Nicolas

    . We report spherical harmonic spectra, comparisons to observatory monthly means, and maps of the radial field at the core-mantle boundary, from the resulting ensemble of core field models. We find that inter-annual fluctuations in the external field (for example related to high solar-driven activity...

  7. The stability and catalytic activity of W13@Pt42 core-shell structure.

    Huo, Jin-Rong; Wang, Xiao-Xu; Li, Lu; Cheng, Hai-Xia; Su, Yan-Jing; Qian, Ping

    2016-10-19

    This paper reports a study of the electronic properties, structural stability and catalytic activity of the W13@Pt42 core-shell structure using the First-principles calculations. The degree of corrosion of W13@Pt42 core-shell structure is simulated in acid solutions and through molecular absorption. The absorption energy of OH for this structure is lower than that for Pt55, which inhibits the poison effect of O containing intermediate. Furthermore we present the optimal path of oxygen reduction reaction catalyzed by W13@Pt42. Corresponding to the process of O molecular decomposition, the rate-limiting step of oxygen reduction reaction catalyzed by W13@Pt42 is 0.386 eV, which is lower than that for Pt55 of 0.5 eV. In addition by alloying with W, the core-shell structure reduces the consumption of Pt and enhances the catalytic efficiency, so W13@Pt42 has a promising perspective of industrial application.

  8. The stability and catalytic activity of W13@Pt42 core-shell structure

    Huo, Jin-Rong; Wang, Xiao-Xu; Li, Lu; Cheng, Hai-Xia; Su, Yan-Jing; Qian, Ping

    2016-01-01

    This paper reports a study of the electronic properties, structural stability and catalytic activity of the W13@Pt42 core-shell structure using the First-principles calculations. The degree of corrosion of W13@Pt42 core-shell structure is simulated in acid solutions and through molecular absorption. The absorption energy of OH for this structure is lower than that for Pt55, which inhibits the poison effect of O containing intermediate. Furthermore we present the optimal path of oxygen reduction reaction catalyzed by W13@Pt42. Corresponding to the process of O molecular decomposition, the rate-limiting step of oxygen reduction reaction catalyzed by W13@Pt42 is 0.386 eV, which is lower than that for Pt55 of 0.5 eV. In addition by alloying with W, the core-shell structure reduces the consumption of Pt and enhances the catalytic efficiency, so W13@Pt42 has a promising perspective of industrial application. PMID:27759038

  9. The stability and catalytic activity of W13@Pt42 core-shell structure

    Huo, Jin-Rong; Wang, Xiao-Xu; Li, Lu; Cheng, Hai-Xia; Su, Yan-Jing; Qian, Ping

    2016-10-01

    This paper reports a study of the electronic properties, structural stability and catalytic activity of the W13@Pt42 core-shell structure using the First-principles calculations. The degree of corrosion of W13@Pt42 core-shell structure is simulated in acid solutions and through molecular absorption. The absorption energy of OH for this structure is lower than that for Pt55, which inhibits the poison effect of O containing intermediate. Furthermore we present the optimal path of oxygen reduction reaction catalyzed by W13@Pt42. Corresponding to the process of O molecular decomposition, the rate-limiting step of oxygen reduction reaction catalyzed by W13@Pt42 is 0.386 eV, which is lower than that for Pt55 of 0.5 eV. In addition by alloying with W, the core-shell structure reduces the consumption of Pt and enhances the catalytic efficiency, so W13@Pt42 has a promising perspective of industrial application.

  10. Terrestrial Gravity Fluctuations

    Jan Harms

    2015-12-01

    Full Text Available Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10^–23 Hz^–1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our

  11. Terrestrial Gravity Fluctuations.

    Harms, Jan

    2015-01-01

    Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10(-23) Hz(-1/2) above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of

  12. Comparison of denitrification activity measurements in groundwater using cores and natural-gradient tracer tests

    Smith, R.L.; Garabedian, S.P.; Brooks, M.H.

    1996-01-01

    The transport of many solutes in groundwater is dependent upon the relative rates of physical flow and microbial metabolism. Quantifying rates of microbial processes under subsurface conditions is difficult and is most commonly approximated using laboratory studies with aquifer materials. In this study, we measured in situ rates of denitrification in a nitrate- contaminated aquifer using small-scale, natural-gradient tracer tests and compared the results with rates obtained from laboratory incubations with aquifer core material. Activity was measured using the acetylene block technique. For the tracer tests, co-injection of acetylene and bromide into the aquifer produced a 30 ??M increase in nitrous oxide after 10 m of transport (23-30 days). An advection-dispersion transport model was modified to include an acetylene-dependent nitrous oxide production term and used to simulate the tracer breakthrough curves. The model required a 4-day lag period and a relatively low sensitivity to acetylene to match the narrow nitrous oxide breakthrough curves. Estimates of in situ denitrification rates were 0.60 and 1.51 nmol of N2O produced cm-3 aquifer day-1 for two successive tests. Aquifer core material collected from the tracer test site and incubated as mixed slurries in flasks and as intact cores yielded rates that were 1.2-26 times higher than the tracer test rate estimates. Results with the coring-dependent techniques were variable and subject to the small- scale heterogeneity within the aquifer, while the tracer tests integrated the heterogeneity along a flow path, giving a rate estimate that is more applicable to transport at the scale of the aquifer.

  13. Effect of Ni Core Structure on the Electrocatalytic Activity of Pt-Ni/C in Methanol Oxidation

    Vladimir Linkov

    2013-07-01

    Full Text Available Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C, were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM, X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS, and methanol oxidation activity compared using CV and chronoamperometry (CA. While both the amorphous Ni core and crystalline Ni core structures were covered by similar Pt shell thickness and structure, the Pt-Ni(amorphous/C catalyst had higher methanol oxidation activity. The amorphous Ni core thus offers improved Pt usage efficiency in direct methanol fuel cells.

  14. Link of volcanic activity and climate change in Altai studied in the ice core from Belukha Mountain

    N. S. Malygina; T. V. Barlyaeva; T. S. Papina

    2013-01-01

    In the present research we discuss a role of volcanic activity in Altai thermal regime. Here we analyses the sulfate and temperature data reconstructed from the natural paleoarchive – ice core from the Belukha Mountain saddle. Sulfate ice-core reconstructions can serve as volcanic markers. The both – sulfate and temperature reconstructions – are for the last 750 years. As the characteristic of volcanic activity we consider Volcanic Explosivity Index (VEI), Dust Veil Index (DVI) and Ice core v...

  15. Terrestrial Gravity Fluctuations

    Harms, Jan

    2015-01-01

    The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of terrestrial gravity fluctuations will have great impact on the future development of GW detectors and high-precision gravimetry in general, and many open questions need to be answered still as emphasized in this article.

  16. The effect of active core exercise on fitness and foot pressure in Taekwondo club students.

    Yoon, Seong-Deok; Sung, Dong-Hun; Park, Gi Duck

    2015-02-01

    [Purpose] The effects of core training using slings and Togus on the improvement of posture control in Taekwondo club students, that is, balance ability, were investigated. To that end, changes in the Taekwondo players' balance ability resulting from active core training for eight weeks were examined through fitness and foot pressure. [Subjects] The present study was conducted with 13 male Taekwondo players of K University in Deagu, South Korea. Once the experiment process was explained, consent was obtained from those who participated voluntarily. [Methods] Air cushions (Germany), Jumpers (Germany), and Aero-Steps (Germany) were used as lumbar stabilization exercise tools. As a method of training proprioceptive senses by stimulating somatesthesia in standing postures, the subjects performed balance squats, supine pelvic lifts, and push-up plus exercise using slings while standing on an Aero-Step and performed hip extension parallel squats (Wall Gym Ball), and standing press-ups on a Togu using their own weight. The subjects performed four sets of these isometric exercises while maintaining an exercise time per set at 30 seconds in each session and repeated this session three times per week. [Result] Left grip strength significantly increased and number of sit-ups, which indicates muscle endurance, also significantly increased after the eight weeks exercise compared with before the exercise. The values measured during the sit and reach test, which indicate flexibility, also significantly increase after the eight weeks of exercise compared with before the exercise but only in the left foot. [Conclusion] The result of present study suggest that active core exercise using Slings and Togus can be applied as a very effective exercise program for enhancing balance, which is an important physical factor for Taekwondo club students.

  17. The Evolution of the EM Distribution in the Core of an Active Region

    Del Zanna, Giulio; Mason, Helen; Subramanian, Srividya; O'Dwyer, Brendan

    2014-01-01

    We study the spatial distribution and evolution of the slope of the Emission Measure between 1 and 3~MK in the core active region NOAA~11193, first when it appeared near the central meridian and then again when it re-appeared after a solar rotation. We use observations recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode, with a new radiometric calibration. We also use observations from the Atmospheric Imaging Assembly (AIA) aboard Solar Dynamics Observatory (SDO). We present the first spatially resolved maps of the EM slope in the 1--3~MK range within the core of the AR using several methods, both approximate and from the Differential Emission Measure (DEM). A significant variation of the slope is found at different spatial locations within the active region. We selected two regions that were not affected too much by any line-of-sight lower temperature emission. We found that the EM had a power law of the form EM~$\\propto T^{b}$, with b = 4.4$\\pm0.4$, and 4.6$\\pm0.4$, during the first...

  18. Pt monolayer shell on hollow Pd core electrocatalysts: Scale up synthesis, structure, and activity for the oxygen reduction reaction

    Vukmirovic Miomir B.

    2013-01-01

    Full Text Available We report on synthesis, characterization and the oxygen reduction reaction (ORR kinetics of Pt monolayer shell on Pd(hollow, or Pd-Au(hollow core electrocatalysts. Comparison between the ORR catalytic activity of the electrocatalysts with hollow cores and those of Pt solid and Pt hollow nanoparticles has been obtained using the rotating disk electrode technique. Hollow nanoparticles were made using Ni or Cu nanoparticles as sacrificial templates. The Pt ORR specific and mass activities of the electrocatalysts with hollow cores were found considerably higher than those of the electrocatalysts with the solid cores. We attribute this enhanced Pt activity to the smooth surface morphology and hollow-induced lattice contraction, in addition to the mass-saving geometry of hollow particles.

  19. The Effect of Performing Bi- and Unilateral Row Exercises on Core Muscle Activation.

    Saeterbakken, A; Andersen, V; Brudeseth, A; Lund, H; Fimland, M S

    2015-11-01

    The purpose of the study was to compare core muscle activation in 3 different row exercises (free-weight bent-over row, seated cable row and machine row) performed unilaterally and bilaterally, at matched effort levels. 15 resistance-trained men (26.0±4.4 years, 81.0±9.5 kg, 1.81±0.07 m) performed the exercises in randomized order. For erector spinae and multifidus, EMG activities in unilateral machine- and cable row were 60-63% and 74-78% of the bilateral performance (P≤0.036). For external oblique, the EMG activities recorded during bilateral exercises were 37-41% of the unilateral performance (P≤0.010). In unilateral cable- and machine rows, the EMG activities in external oblique and multifidus were 50-57% and 70-73% of the free-weight row (P≤0.002). In bilateral free-weight row, EMG activity in erector spinae was greater than bilateral machine- (+34%, P=0.004) and unilateral free-weight rows (+12%, P=0.016). For rectus abdominis there were no significant differences between conditions. In conclusion, 1) free-weight row provided greater EMG activity in erector spinae (bilaterally and unilaterally) and multifidus (unilaterally) than machine row; 2) unilateral performance of exercises activated the external oblique more than bilateral performance, regardless of exercise; and 3) generally bilateral performance of exercises provided higher erector spinae and multifidus EMG activity compared to unilateral performance.

  20. Changes of Nitric Oxide Synthase Activity in Penumbral and Core Area during Focal Cerebral Ischemia and Reperfusion in Rats

    GUZhen; ZHOUJian-ping; WUWen-zhong; ZHANGYong-jie; HANQun-ying; WANGHe-ming

    2004-01-01

    Objecivee: To study the changes of nitric oxide synthase (NOS) activity in penumbral and core area during focal cerebral ischemia and reperfusion, and to explore the therapeutic window of focal cerebral ischemia. Methods:The middle cerebral artery of rats was occluded for 15, 30,60,90 and 120 min by an inraluminal filament respectively,and recirculation was instituted for 24 h. The changes of NOS activity in ischemic core area(parietal cortex and caudoputamen) and penumbral area ( frontal cortex)were examined after focal cerebral ischemla and reperfusion using NADPH-d histochemistry, technique. Results. The NOS activity of the ischemic penumbral area peaked at 60 min while the ischemic core area peaked at 30 min then declined at 90-120 rain sharply. Conclusion: NOS takes part in cerebral ischemic damage during focal cerebral ischemia and reperfusion. The NOS activity of the ischemic penmnbral area is different from the ischemic core area. The peak time of the penumbral area is delayed comparing with the core area. The data suggest that the best time to apply NOS inhibitor is within 30 min in ischemic core area, and 60 rain in penumbral area.

  1. Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

    Dongmei Zhang; Lizhi Zhou; Yunwei Song

    2015-01-01

    Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in

  2. Core microbial functional activities in ocean environments revealed by global metagenomic profiling analyses.

    Ari J S Ferreira

    Full Text Available Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world's oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light.

  3. Core microbial functional activities in ocean environments revealed by global metagenomic profiling analyses.

    Ferreira, Ari J S

    2014-06-12

    Metagenomics-based functional profiling analysis is an effective means of gaining deeper insight into the composition of marine microbial populations and developing a better understanding of the interplay between the functional genome content of microbial communities and abiotic factors. Here we present a comprehensive analysis of 24 datasets covering surface and depth-related environments at 11 sites around the world\\'s oceans. The complete datasets comprises approximately 12 million sequences, totaling 5,358 Mb. Based on profiling patterns of Clusters of Orthologous Groups (COGs) of proteins, a core set of reference photic and aphotic depth-related COGs, and a collection of COGs that are associated with extreme oxygen limitation were defined. Their inferred functions were utilized as indicators to characterize the distribution of light- and oxygen-related biological activities in marine environments. The results reveal that, while light level in the water column is a major determinant of phenotypic adaptation in marine microorganisms, oxygen concentration in the aphotic zone has a significant impact only in extremely hypoxic waters. Phylogenetic profiling of the reference photic/aphotic gene sets revealed a greater variety of source organisms in the aphotic zone, although the majority of individual photic and aphotic depth-related COGs are assigned to the same taxa across the different sites. This increase in phylogenetic and functional diversity of the core aphotic related COGs most probably reflects selection for the utilization of a broad range of alternate energy sources in the absence of light.

  4. The effects of core stability strength exercise on muscle activity and trunk impairment scale in stroke patients

    Yu, Seong-Hun; Park, Seong-Doo

    2013-01-01

    The purpose of this study was to examine the effects of core stability-enhancing exercises on the lower trunk and muscle activity of stroke patients. The control group (n = 10) underwent standard exercise therapy, while the experiment group (n =10) underwent both the core stability-enhancing exercise and standard exercise therapy simultaneously. The standard exercise therapy applied to the two groups included weight bearing and weight shifts and joint movements to improve flexibility and the ...

  5. Activities for Challenging Gifted Learners by Increasing Complexity in the Common Core

    McKeone, Alyssa; Caruso, Lenora; Bettle, Kailyn; Chase, Ashley; Bryson, Bridget; Schneider, Jean S.; Rule, Audrey C.

    2015-01-01

    Gifted learners need opportunities for critical and creative thinking to stretch their minds and imaginations. Strategies for increasing complexity in the four core areas of language arts, mathematics, science, and social studies were addressed using the Common Core and Iowa Core Standards through several methods. Descriptive adjective object…

  6. Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE

    Warren, Harry P; Brooks, David H

    2009-01-01

    The timescale for energy release is an important parameter for constraining the coronal heating mechanism. Observations of "warm" coronal loops (~1 MK) have indicated that the heating is impulsive and that coronal plasma is far from equilibrium. In contrast, observations at higher temperatures (~3 MK) have generally been consistent with steady heating models. Previous observations, however, have not been able to exclude the possibility that the high temperature loops are actually composed of many small scale threads that are in various stages of heating and cooling and only appear to be in equilibrium. With new observations from the EUV Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode we have the ability to investigate the properties of high temperature coronal plasma in extraordinary detail. We examine the emission in the core of an active region and find three independent lines of evidence for steady heating. We find that the emission observed in XRT is generally steady for hours, with a fluct...

  7. Core activities and career pathways of independent trainers-consultants in France

    Laurence Bonnafous

    2015-10-01

    Full Text Available This paper presents some of the key findings from a 2013 survey achieved with a representative sample of 101 independent trainers-consultants, members of a French trade union. These results highlight more particularly their socio-demographic characteristics, their core activities and four main career pathways identified. This survey was part of a two years action research, conducted in a partnership between this professional trade union and university laboratories in the field of adult education. The aim was to improve the understanding of this specific professional group, of its ongoing professionalization process and its visibility as one of the actors of the continuing education and vocational training (CVET system in France.

  8. Fuzzy Decision Support for Tools Selection in the Core Front End Activities of New Product Development

    Achiche, S.; Appio, F.P.; McAloone, Tim C.

    2013-01-01

    The innovation process may be divided into three main parts: the front end (FE), the new product development (NPD) process, and the commercialization. Every NPD process has a FE in which products and projects are defined. However, companies tend to begin the stages of FE without a clear definition......, an economic evaluation of the cost of tool usage is critical, and there is furthermore a need to characterize them in terms of their influence on the FE. This paper focuses on decision support for managers/ designers in their process of assessing the cost of choosing/using tools in the core front end (CFE......) activities identified by Koen, namely Opportunity Identification and Opportunity Analysis. This is achieved by first analyzing the influencing factors (firm context, industry context, macroenvironment) along with data collection from managers followed by the automatic construction of fuzzy decision support...

  9. Binding stability of peptides derived from 1ALA residue and 7GLY residues to sites near active center of fluctuating papain

    Nishiyama, Katsuhiko

    2012-05-01

    We investigated the binding stability of peptides derived from 1ALA residue and 7GLY residues to sites near active center of fluctuating papain via molecular dynamics and docking simulations. Replacing GLY residue in 8GLY with ALA residue had a positive effect on binding stability to the sites in some cases although the replacing had a negative effect on it in other cases. Furthermore the replacing had a negative effect on the chance of binding to the sites. Residue in peptide should be replaced on the basis of systematic exploration of its position.

  10. Phosphate glass core/silica clad fibres with a high concentration of active rare-earth ions

    Egorova, O. N.; Galagan, B. I.; Denker, B. I.; Sverchkov, S. E.; Semjonov, S. L.

    2016-12-01

    We report a study of silica-clad composite optical fibres having a phosphate glass core doped with active rare-earth elements. The phosphate glass core allows a high concentration of active rare-earth ions to be obtained, and the silica cladding ensures high mechanical strength and facilitates fusion splicing of such fibres to silica fibres. Owing to the high concentration of active rare-earth ions, this type of fibre is potentially attractive for applications where a small cavity length and high lasing efficiency are needed.

  11. The effects of core stability strength exercise on muscle activity and trunk impairment scale in stroke patients.

    Yu, Seong-Hun; Park, Seong-Doo

    2013-01-01

    The purpose of this study was to examine the effects of core stability-enhancing exercises on the lower trunk and muscle activity of stroke patients. The control group (n = 10) underwent standard exercise therapy, while the experiment group (n =10) underwent both the core stability-enhancing exercise and standard exercise therapy simultaneously. The standard exercise therapy applied to the two groups included weight bearing and weight shifts and joint movements to improve flexibility and the range of motion. The core stability-enhancing exercise was performed 5 times a week for 30 min over a period of 4 weeks in the room where the patients were treated. For all 20 subject, the items measured before the exercise were measured after the therapeutic intervention, and changes in muscle activity of the lower trunk were evaluated. The activity and stability of the core muscles were measured using surface electromyography and the trunk impairment scale (TIS). The mean TIS score and muscle activity of the lower trunk increased in the experiment group significantly after performing the core stability-enhancing exercise (Pcore stability-enhancing exercise is effective in improving muscle activity of the lower trunk, which is affected by hemiplegia.

  12. Negative core affect and employee silence: How differences in activation, cognitive rumination, and problem-solving demands matter.

    Madrid, Hector P; Patterson, Malcolm G; Leiva, Pedro I

    2015-11-01

    Employees can help to improve organizational performance by sharing ideas, suggestions, or concerns about practices, but sometimes they keep silent because of the experience of negative affect. Drawing and expanding on this stream of research, this article builds a theoretical rationale based on core affect and cognitive appraisal theories to describe how differences in affect activation and boundary conditions associated with cognitive rumination and cognitive problem-solving demands can explain employee silence. Results of a diary study conducted with professionals from diverse organizations indicated that within-person low-activated negative core affect increased employee silence when, as an invariant factor, cognitive rumination was high. Furthermore, within-person high-activated negative core affect decreased employee silence when, as an invariant factor, cognitive problem-solving demand was high. Thus, organizations should manage conditions to reduce experiences of low-activated negative core affect because these feelings increase silence in individuals high in rumination. In turn, effective management of experiences of high-activated negative core affect can reduce silence for individuals working under high problem-solving demand situations.

  13. Inhibition of reverse transcriptase activity increases stability of the HIV-1 core.

    Yang, Yang; Fricke, Thomas; Diaz-Griffero, Felipe

    2013-01-01

    Previous studies showed that HIV-1 reverse transcription occurs during or before uncoating, linking mechanistically reverse transcription with uncoating. Here we show that inhibition of reverse transcriptase (RT) during HIV-1 infection by pharmacologic or genetic means increased the stability of the HIV-1 core during infection. Interestingly, HIV-1 particles with increased core stability were resistant to the core-destabilizing effects of rhesus TRIM5α (TRIM5α(rh)). Collectively, this work implies that the surface of the HIV-1 core is dynamic and changes upon the ongoing processes within the core.

  14. Effects of the CORE Exercise Program on Pain and Active Range of Motion in Patients with Chronic Low Back Pain.

    Cho, Hwi-Young; Kim, Eun-Hye; Kim, Junesun

    2014-08-01

    [Purpose] This study aimed to identify the effects of the CORE exercise program on pain and active range of motion (AROM) in patients with chronic low back pain. [Subjects and Methods] Thirty subjects with chronic low back pain were randomly allocated to two groups: the CORE group (n = 15) and the control group (n = 15). The CORE group performed the CORE exercise program for 30 minutes a day, 3 times a week, for 4 weeks, while the control group did not perform any exercise. The visual analog scale (VAS) and an algometer were used to measure pain, and pain-free AROM in the trunk was measured before and after the intervention. [Results] The CORE group showed significantly decreased VAS scores at rest and during movement and had a significantly increased pressure pain threshold in the quadratus lumborum and AROM in the trunk compared with those in the control group. [Conclusion] This study demonstrated that the CORE exercise program is effective in decreasing pain and increasing AROM in patients with chronic low back pain. Thus, the CORE exercise program can be used to manage pain and AROM in patients with chronic low back pain.

  15. Nonlocally of plasma fluctuations and transport in magnetically confined plasmas theoretical background of nonlocality in fluctuations

    Itoh, Kimitaka [National Inst. for Fusion Science, Toki, Gifu (Japan); Itoh, Sanae-I.; Yagi, Masatoshi [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    2002-09-01

    Nonlocal properties of fluctuations in confined plasmas are briefly surveyed. Contributions to understanding the bifurcation phenomena, improved confinement, and transient transport problem are explained. The theoretical progress in this aspect is addressed: Namely, the fluctuations are not excited by linear instabilities but are dressed with other turbulent fluctuations or fluctuations of meso-scale. Nonlinear interactions of fluctuations with different scale lengths are essential in dictating the dynamics of turbulence and turbulent transport. There are activators and suppressers in global inhomogeneities for evolution of turbulence. Turbulent fluctuations, on the other hand, induce or destroy these global inhomogeneities. Finally, statistical nature of turbulence is addressed. (author)

  16. A Conserved Hydrophobic Core in Gαi1 Regulates G Protein Activation and Release from Activated Receptor.

    Kaya, Ali I; Lokits, Alyssa D; Gilbert, James A; Iverson, T M; Meiler, Jens; Hamm, Heidi E

    2016-09-09

    G protein-coupled receptor-mediated heterotrimeric G protein activation is a major mode of signal transduction in the cell. Previously, we and other groups reported that the α5 helix of Gαi1, especially the hydrophobic interactions in this region, plays a key role during nucleotide release and G protein activation. To further investigate the effect of this hydrophobic core, we disrupted it in Gαi1 by inserting 4 alanine amino acids into the α5 helix between residues Gln(333) and Phe(334) (Ins4A). This extends the length of the α5 helix without disturbing the β6-α5 loop interactions. This mutant has high basal nucleotide exchange activity yet no receptor-mediated activation of nucleotide exchange. By using structural approaches, we show that this mutant loses critical hydrophobic interactions, leading to significant rearrangements of side chain residues His(57), Phe(189), Phe(191), and Phe(336); it also disturbs the rotation of the α5 helix and the π-π interaction between His(57) and Phe(189) In addition, the insertion mutant abolishes G protein release from the activated receptor after nucleotide binding. Our biochemical and computational data indicate that the interactions between α5, α1, and β2-β3 are not only vital for GDP release during G protein activation, but they are also necessary for proper GTP binding (or GDP rebinding). Thus, our studies suggest that this hydrophobic interface is critical for accurate rearrangement of the α5 helix for G protein release from the receptor after GTP binding.

  17. Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model

    Winebarger, Amy R.; Schmelz, Joan T.; Warren, Harry P.; Saar, Steve H.; Kashyap, Vinay L.

    2011-10-01

    The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this paper, we couple observations of active region (AR) 10955 made with the X-Ray Telescope and the EUV Imaging Spectrometer on board Hinode to test a simple steady heating model. First we calculate the differential emission measure (DEM) of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3 MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. We find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.

  18. Reasons and Predictions of The Caspian Sea Water Level Fluctuations: Impact of Climate Factors and Man's Activities.

    Erlich, M.; Shiklomanov, I.; Yezhov, A.; Georgievsky, V.; Shalygin, A.

    The Caspian Sea - the largest lake in the world - has no connection with the Ocean and is lower than its surface. Fluctuations of the Sea level are very significant: during the period of instrumental observations (since 1830) the level amplitude was 3.78 m with maximum of -25.22 m in 1882 and minimum of -29.00 m in 1978. These fluctuations lead to a great damage for the economy of five countries sharing its coast (Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan). Deep knowledge of hydrological and hydrodynamic Sea regime and scientifically justified forecasts of possible changes in its level, taking into account variability in climate and future climate change, are re- quired for undertaking urgent measures for protection of coastal territories. The inter- national research project CASSEAS, carried out in 1997-2000 within the framework of the INCO-COPERNICUS programme by the scientists of 5 countries: France, Rus- sia, Germany, Turkmenistan and UK, was devoted to these problems. Research made within the Project made it possible to get new precise data on all water balance com- ponents of the Caspian Sea for 1880-1996; moreover, all water balance components for 1940-1996 were computed independently. It was shown that the Sea level fluctua- tions depended on the water balance almost completely. Assessment of possible future runoff changes in the Caspian Sea basin was made using the mathematical model of runoff formation developed at the SHI. Several scenarios from a range of GCMs and on the basis of paleoclimatic reconstructions were used as the models of the future climate for the nearest 3 decades. Besides changes in climate characteristics, three variants were accepted for the future water use in the basins of rivers discharging to the Caspian Sea. All scenarios gave similar results for changes in annual river inflow to the Caspian Sea: its increase would be from 5% to 10% by 2030. The same scenarios, used to estimate changes in precipitation onto the Sea

  19. Core-shell nanocarriers with high paclitaxel loading for passive and active targeting

    Jin, Zhu; Lv, Yaqi; Cao, Hui; Yao, Jing; Zhou, Jianping; He, Wei; Yin, Lifang

    2016-06-01

    Rapid blood clearance and premature burst release are inherent drawbacks of conventional nanoparticles, resulting in poor tumor selectivity. iRGD peptide is widely recognized as an efficient cell membrane penetration peptide homing to αVβ3 integrins. Herein, core-shell nanocapsules (NCs) and iRGD-modified NCs (iRGD-NCs) with high drug payload for paclitaxel (PTX) were prepared to enhance the antitumor activities of chemotherapy agents with poor water solubility. Improved in vitro and in vivo tumor targeting and penetration were observed with NCs and iRGD-NCs; the latter exhibited better antitumor activity because iRGD enhanced the accumulation and penetration of NCs in tumors. The NCs were cytocompatible, histocompatible, and non-toxic to other healthy tissues. The endocytosis of NCs was mediated by lipid rafts in an energy-dependent manner, leading to better cytotoxicity of PTX against cancer cells. In contrast with commercial product, PTX-loaded NCs (PTX-NCs) increased area under concentration-time curve (AUC) by about 4-fold, prolonged mean resident time (MRT) by more than 8-fold and reduced the elimination rate constant by greater than 68-fold. In conclusion, the present nanocarriers with high drug-loading capacity represent an efficient tumor-targeting drug delivery system with promising potential for cancer therapy.

  20. Discussion on sea level fluctuations along the Adriatic coasts coupling to climate indices forced by solar activity: Insights into the future of Venice

    Zanchettin, Davide; Traverso, Pietro; Tomasino, Mario

    2006-04-01

    The North Atlantic Oscillation (NAO), which is a dominant circulation pattern in Northern Hemisphere winter, is known to affect sea-level variability in the Mediterranean Sea mainly through the hydrostatic response of water masses to pressure anomalies and changes in evaporation/precipitation budgets. In this study the influence of the NAO on sea levels along the Adriatic coasts is re-assessed in the attempt to uncover the potential causes of the observed high sensitivity of the northern basin to NAO fluctuations. The investigation is focused on the role of the NAO as forcing factor of the winds blowing in the area and of the freshwaters input from the Po River, both of which influence the hydrodynamics of the Northern Adriatic. In addition, some insights into the future of Venice are discussed on the basis of the hypothesis that NAO phases are modulated by the varying solar activity through the intensity of the Earth's geomagnetic activity.

  1. Synthesis of N-halamine-functionalized silica-polymer core-shell nanoparticles and their enhanced antibacterial activity

    Dong, Alideertu; Huang, Jinfeng; Lan, Shi; Wang, Tao; Xiao, Linghan; Wang, Weiwei; Zhao, Tianyi; Zheng, Xin; Liu, Fengqi; Gao, Ge; Chen, Yuxin

    2011-07-01

    N-halamine-functionalized silica-polymer core-shell nanoparticles with enhanced antibacterial activity were synthesized through the encapsulation of silica nanoparticles as support with polymeric N-halamine. The as-synthesized nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive x-ray spectrometry (EDX), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR). These N-halamine-functionalized silica-polymer core-shell nanoparticles displayed powerful antibacterial performance against both Gram-positive bacteria and Gram-negative bacteria, and their antibacterial activities have been greatly improved compared with their bulk counterparts. Therefore, these N-halamine-functionalized silica-polymer core-shell nanoparticles have the potential for various significant applications such as in medical devices, healthcare products, water purification systems, hospitals, dental office equipment, food packaging, food storage, household sanitation, etc.

  2. Synthesis of N-halamine-functionalized silica-polymer core-shell nanoparticles and their enhanced antibacterial activity

    Dong, Alideertu; Wang Tao; Xiao Linghan; Wang Weiwei; Zhao Tianyi; Zheng Xin; Liu Fengqi; Gao Ge [College of Chemistry, Jilin University and MacDiarmid Laboratory, Changchun 130021 (China); Huang Jinfeng; Chen Yuxin [Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, Jilin University, Changchun 130012 (China); Lan Shi, E-mail: gaoge@jlu.edu.cn [College of Chemistry and Chemical Engineering, Inner Mongolia University for the Nationalities, Tongliao 028000 (China)

    2011-07-22

    N-halamine-functionalized silica-polymer core-shell nanoparticles with enhanced antibacterial activity were synthesized through the encapsulation of silica nanoparticles as support with polymeric N-halamine. The as-synthesized nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive x-ray spectrometry (EDX), dynamic light scattering (DLS), thermogravimetric analysis (TGA), and Fourier transform infrared (FTIR). These N-halamine-functionalized silica-polymer core-shell nanoparticles displayed powerful antibacterial performance against both Gram-positive bacteria and Gram-negative bacteria, and their antibacterial activities have been greatly improved compared with their bulk counterparts. Therefore, these N-halamine-functionalized silica-polymer core-shell nanoparticles have the potential for various significant applications such as in medical devices, healthcare products, water purification systems, hospitals, dental office equipment, food packaging, food storage, household sanitation, etc.

  3. DNA intercalation studies and antimicrobial activity of Ag@ZrO2 core-shell nanoparticles in vitro.

    Dhanalekshmi, K I; Meena, K S

    2016-02-01

    Ag@ZrO2 core-shell nanoparticles were prepared by one pot simultaneous reduction of AgNO3 and hydrolysis of zirconium (IV) isopropoxide. The formation of core-shell nanoparticles was confirmed by absorption, XRD, and HR-TEM techniques. The antibacterial activity of Ag@ZrO2 core-shell nanoparticles against Escherichia coli and Staphylococcus aureus and the antifungal properties against Candida albicans, Candida glabrata, Aspergillus niger and Aspergillus flavus were examined by the agar diffusion method. DNA intercalation studies were carried out in CT-DNA. As a result ZrO2 supported on the surface of AgNPs not only prevented aggregation, but also proved to have enhanced antimicrobial activity and DNA intercalation than the Ag nanoparticles.

  4. Masking of the circadian rhythms of heart rate and core temperature by the rest-activity cycle in man

    Gander, Philippa H.; Connell, Linda J.; Graeber, R. Curtis

    1986-01-01

    Experiments were conducted to estimate the magnitude of the masking effect produced in humans by alternate periods of physical activity and rest or sleep on the circadian rhythms of heart rate and core temperature. The heart rate, rectal temperature, and nondominant wrist activity were monitored in 12 male subjects during 6 days of normal routine at home and during 6 days of controlled bed-rest regimen. The comparisons of averaged waveforms for the activity, heart rate, and temperature indicated that about 45 percent of the range of the circadian heart rate rhythm during normal routine and about 14 percent of the range of the circadian temperature rhythm were attributable to the effects of activity. The smaller effect of activity on the temperature rhythm may be partially attributable to the fact that core temperature is being more rigorously conserved than heart rate, at least during moderate exercise.

  5. Enhance the Er(3+) Upconversion Luminescence by Constructing NaGdF4:Er(3+)@NaGdF4:Er(3+) Active-Core/Active-Shell Nanocrystals.

    Du, Xiaoyu; Wang, Xiangfu; Meng, Lan; Bu, Yanyan; Yan, Xiaohong

    2017-12-01

    NaGdF4:12%Er(3+)@NaGdF4:x%Er(3+) (x = 0, 6, 8, 10, and 12) active-core/active-shell nanoparticles (NPs) were peculiarly synthesized via a delayed nucleation pathway with procedures. The phase, shape, and size of the resulting core-shell NPs are confirmed by transmission electron microscopy and X-ray diffraction. Coated with a NaGdF4:10%Er(3+) active shell around the NaGdF4:12%Er(3+) core NPs, a maximum luminescent enhancement of about 336 times higher than the NaGdF4:12%Er(3+) core-only NPs was observed under the 1540 nm excitation. The intensity ratio of green to red was adjusted through the construction of the core-shell structure and the change of Er(3+) concentration in the shell. By analyzing the lifetimes of emission bands and exploring the energy transition mechanism, the giant luminescence enhancement is mainly attributed to the significant increase in the near-infrared absorption at 1540 nm and efficient energy migration from the shell to core.

  6. Unified nuclear core activity map reconstruction using heterogeneous instruments with data assimilation

    Bouriquet, Bertrand; Erhard, Patrick; Ponçot, Angélique

    2011-01-01

    Evaluating the neutronic state of the whole nuclear core is a very important topic that have strong implication for nuclear core management and for security monitoring. The core state is evaluated using measurements. Usually, part of the measurements are used, and only one kind of instruments are taken into account. However, the core state evaluation should be more accurate when more measurements are collected in the core. But using information from heterogeneous sources is at glance a difficult task. This difficulty can be overcome by Data Assimilation techniques. Such a method allows to combine in a coherent framework the information coming from model and the one coming from various type of observations. Beyond the inner advantage to use heterogeneous instruments, this leads to obtain a significant increasing of the quality of neutronic global state reconstruction with respect to individual use of measures. In order to present this approach, we will introduce here the basic principles of data assimilation f...

  7. Core Muscle Activation During Unstable Bicep Curl Using a Water-Filled Instability Training Tube.

    Glass, Stephen C; Blanchette, Taylor W; Karwan, Lauren A; Pearson, Spencer S; OʼNeil, Allison P; Karlik, Dustin A

    2016-11-01

    Glass, SC, Blanchette, TW, Karwan, LA, Pearson, SS, O'Neil, AP, and Karlik, DA. Core muscle activation during unstable bicep curl using a water-filled instability training tube. J Strength Cond Res 30(11): 3212-3219, 2016-The purpose of this study was to assess compensatory muscle activation created during a bicep curl using a water-filled, unstable lifting tube. Ten men (age = 21 ± 1.6 years, height = 180.0 ± 3.3 cm, mass = 87.4 ± 15.0 kg) and 10 women (age = 19.6 ± 1.3 years, height = 161.4 ± 12.0 cm, mass = 61.2 ± 7.4 kg) completed bicep curls using an 11.4-kg tube partially filled with water during a 50% open-valve, 100% open, and control setting. Subjects completed 8 repetitions within each condition with integrated electromyographic signal (converted to percent maximal voluntary contraction) of the bicep, deltoid, rectus abdominus, and paraspinal muscles measured. Compensatory activation was determined using the natural log of coefficient of variation across concentric (CON) and eccentric (ECC) contractions. There were no differences between gender for any condition. Significant variability was seen across treatments for paraspinal muscles for CON and ECC at 50% (CON LnCV = 3.13 ± 0.56%, ECC LnCV = 3.34 ± 0.58%) and 100% (CON = 3.24 ± 0.34%, ECC = 3.46 ± 0.35%) compared with control (CON = 2.59 ± 0.47%, ECC = 2.80 ± 0.61%). Deltoid variability was greater at the 100% open setting (CON = 3.51 ± 0.53%, ECC = 3.56 ± 0.36%) compared with control (CON = 2.98 ± 0.35%, ECC = 2.97 ± 0.45%). The abdominal CON 100% showed variability (3.02 ± 0.47%) compared with control (2.65 ± 0.43%). Bicep activation remained unvaried. Compensatory activation of postural muscles contribute to postural stability. This device may be a useful tool for neuromuscular training leading to improved stability and control.

  8. A new gravitational-wave signature of SASI activities in non-rotating supernova cores

    Kuroda, Takami; Takiwaki, Tomoya

    2016-01-01

    We present results from fully relativistic three-dimensional core-collapse supernova (CCSN) simulations of a non-rotating 15 M_sun star using three different nuclear equations of state (EoSs). From our simulations covering up to ~350 ms after bounce, we show that the development of the standing accretion shock instability (SASI) differs significantly depending on the stiffness of nuclear EoS. Generally, the SASI activity occurs more vigorously in models with softer EoS. By evaluating the gravitational-wave (GW) emission, we find a new GW signature on top of the previously identified one, in which the typical GW frequency increases with time due to an accumulating accretion to the proto-neutron star (PNS). The newly observed quasi-periodic signal appears in the frequency range from ~100 to 200 Hz and persists for ~150 ms before neutrino-driven convection dominates over the SASI. By analyzing the cycle frequency of the SASI sloshing and spiral modes as well as the mass accretion rate to the emission region, we ...

  9. SASI Activity in Three-Dimensional Neutrino-Hydrodynamics Simulations of Supernova Cores

    Hanke, F; Wongwathanarat, A; Marek, A; Janka, H -Th

    2013-01-01

    The relevance of the standing accretion shock instability (SASI) compared to neutrino-driven convection in three-dimensional (3D) supernova-core environments is still highly controversial. Studying a 27 Msun progenitor, we demonstrate, for the first time, that violent SASI activity can develop in 3D simulations with detailed neutrino transport despite the presence of convection. This result was obtained with the Prometheus-Vertex code with the same sophisticated neutrino treatment so far used only in 1D and 2D models. While buoyant plumes initially determine the nonradial mass motions in the postshock layer, bipolar shock sloshing with growing amplitude sets in during a phase of shock retraction and turns into a violent spiral mode whose growth is only quenched when the infall of the Si/SiO interface leads to strong shock expansion in response to a dramatic decrease of the mass accretion rate. In the phase of large-amplitude SASI sloshing and spiral motions, the postshock layer exhibits nonradial deformation ...

  10. Lattice-Strain Control of Exceptional Activity in Dealloyed Core-Shell Fuel Cell Catalysts

    Strasser, Peter

    2011-08-19

    We present a combined experimental and theoretical approach to demonstrate how lattice strain can be used to continuously tune the catalytic activity of the oxygen reduction reaction (ORR) on bimetallic nanoparticles that have been dealloyed. The sluggish kinetics of the ORR is a key barrier to the adaptation of fuel cells and currently limits their widespread use. Dealloyed Pt-Cu bimetallic nanoparticles, however, have been shown to exhibit uniquely high reactivity for this reaction. We first present evidence for the formation of a core-shell structure during dealloying, which involves removal of Cu from the surface and subsurface of the precursor nanoparticles. We then show that the resulting Pt-rich surface shell exhibits compressive strain that depends on the composition of the precursor alloy. We next demonstrate the existence of a downward shift of the Pt d-band, resulting in weakening of the bond strength of intermediate oxygenated species due to strain. Finally, we combine synthesis, strain, and catalytic reactivity in an experimental/theoretical reactivity-strain relationship which provides guidelines for the rational design of strained oxygen reduction electrocatalysts. The stoichiometry of the precursor, together with the dealloying conditions, provides experimental control over the resulting surface strain and thereby allows continuous tuning of the surface electrocatalytic reactivity - a concept that can be generalized to other catalytic reactions.

  11. Synthesis, Optical Properties, and Photocatalytic Activity of One-Dimensional CdS@ZnS Core-Shell Nanocomposites

    Wang Le

    2009-01-01

    Full Text Available Abstract One-dimensional (1D CdS@ZnS core-shell nanocomposites were successfully synthesized via a two-step solvothermal method. Preformed CdS nanowires with a diameter of ca. 45 nm and a length up to several tens of micrometers were coated with a layer of ZnS shell by the reaction of zinc acetate and thiourea at 180 °C for 10 h. It was found that uniform ZnS shell was composed of ZnS nanoparticles with a diameter of ca. 4 nm, which anchored on the nanowires without any surface pretreatment. The 1D CdS@ZnS core-shell nanocomposites were confirmed by XRD, SEM, TEM, HR-TEM, ED, and EDS techniques. The optical properties and photocatalytic activities of the 1D CdS@ZnS core-shell nanocomposites towards methylene blue (MB and 4-chlorophenol (4CP under visible light (λ > 420 nm were separately investigated. The results show that the ZnS shell can effectively passivate the surface electronic states of the CdS cores, which accounts for the enhanced photocatalytic activities of the 1D CdS@ZnS core-shell nanocomposites compared to that of the uncoated CdS nanowires.

  12. Fabrication of Fe3O4@CuO core-shell from MOF based materials and its antibacterial activity

    Rajabi, S. K.; Sohrabnezhad, Sh.; Ghafourian, S.

    2016-12-01

    Magnetic Fe3O4@CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe3O4@HKUST-1 in air atmosphere. The morphology, structure, magnetic and porous properties of the as-synthesized nano composites were characterized by using scanning electron microscope (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD), and vibration sample magnetometer (VSM). The results showed that the nanocomposite material included a Fe3O4 core and a CuO shell. The Fe3O4@CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe3O4-CuO core-shell was investigated against gram-positive and gram-negative bacteria. A new mechanism was proposed for inactivation of bacteria over the prepared sample. It was demonstrated that the core-shell exhibit recyclable antibacterial activity, acting as an ideal long-acting antibacterial agent.

  13. Teaching Core Content Embedded in a Functional Activity to Students with Moderate Intellectual Disability Using a Simultaneous Prompting Procedure

    Karl, Jennifer; Collins, Belva C.; Hager, Karen D.; Ault, Melinda Jones

    2013-01-01

    The purpose of this study was to investigate the effects of a simultaneous prompting procedure in teaching four secondary students with moderate intellectual disability to acquire and generalize core content embedded in a functional activity. Data gathered within the context of a multiple probe design revealed that all participants learned the…

  14. An objective fluctuation score for Parkinson's disease.

    Malcolm K Horne

    Full Text Available Establishing the presence and severity of fluctuations is important in managing Parkinson's Disease yet there is no reliable, objective means of doing this. In this study we have evaluated a Fluctuation Score derived from variations in dyskinesia and bradykinesia scores produced by an accelerometry based system.The Fluctuation Score was produced by summing the interquartile range of bradykinesia scores and dyskinesia scores produced every 2 minutes between 0900-1800 for at least 6 days by the accelerometry based system and expressing it as an algorithm.This Score could distinguish between fluctuating and non-fluctuating patients with high sensitivity and selectivity and was significant lower following activation of deep brain stimulators. The scores following deep brain stimulation lay in a band just above the score separating fluctuators from non-fluctuators, suggesting a range representing adequate motor control. When compared with control subjects the score of newly diagnosed patients show a loss of fluctuation with onset of PD. The score was calculated in subjects whose duration of disease was known and this showed that newly diagnosed patients soon develop higher scores which either fall under or within the range representing adequate motor control or instead go on to develop more severe fluctuations.The Fluctuation Score described here promises to be a useful tool for identifying patients whose fluctuations are progressing and may require therapeutic changes. It also shows promise as a useful research tool. Further studies are required to more accurately identify therapeutic targets and ranges.

  15. The arginine residue within the C-terminal active core of Bombyx mori pheromone biosynthesis-activating neuropeptide (PBAN is essential for receptor binding and activation

    Takeshi eKawai

    2012-03-01

    Full Text Available In most lepidopteran insects, the biosynthesis of sex pheromones is regulated by pheromone biosynthesis activating neuropeptide (PBAN. Bombyx mori PBAN (BomPBAN consists of 33 amino acid residues and contains a C-terminus FSPRLamide motif as the active core. Among neuropeptides containing the FXPRLamide motif, the arginine (Arg, R residue two positions from the C-terminus is highly conserved across several neuropeptides, which can be designated as RXamide peptides. The purpose of this study was to reveal the role of the Arg residue in the BomPBAN active core. We synthesized a ten-residue peptide corresponding to the C-terminal part of BomPBAN with a series of point mutants at the 2nd position (ie, Arg from the C-terminus, termed the C2 position, and measured their efficacy in stimulating Ca2+ influx in insect cells concomitantly expressing a fluorescent PBAN receptor chimera (PBANR-EGFP and loaded with the fluorescent Ca2+ indicator, Fura Red-AM. PBAN analogs with the C2 position replaced with alanine (Ala, A, aspartic acid (Asp, D, serine (Ser, S or L-2-aminooctanoic acid (Aoc decreased PBAN-like activity. RC2A (SKTRYFSPALamide and RC2D (SKTRYFSPDLamide had the lowest activity and could not inhibit the activity of PBAN C10 (SKTRYFSPRLamide. We also prepared Rhodamine Red-labeled PBAN analogs of the mutants and examined their ability to bind PBANR. In contrast to 100 nM Rhodamine Red-PBAN C10, none of the mutants at the same concentration exhibited PBANR binding. Taken together, our results demonstrate that the C2 Arg residue in BomPBAN is essential for PBANR binding and activation.

  16. Synchronization, non-linear dynamics and low-frequency fluctuations: analogy between spontaneous brain activity and networked single-transistor chaotic oscillators.

    Minati, Ludovico; Chiesa, Pietro; Tabarelli, Davide; D'Incerti, Ludovico; Jovicich, Jorge

    2015-03-01

    In this paper, the topographical relationship between functional connectivity (intended as inter-regional synchronization), spectral and non-linear dynamical properties across cortical areas of the healthy human brain is considered. Based upon functional MRI acquisitions of spontaneous activity during wakeful idleness, node degree maps are determined by thresholding the temporal correlation coefficient among all voxel pairs. In addition, for individual voxel time-series, the relative amplitude of low-frequency fluctuations and the correlation dimension (D2), determined with respect to Fourier amplitude and value distribution matched surrogate data, are measured. Across cortical areas, high node degree is associated with a shift towards lower frequency activity and, compared to surrogate data, clearer saturation to a lower correlation dimension, suggesting presence of non-linear structure. An attempt to recapitulate this relationship in a network of single-transistor oscillators is made, based on a diffusive ring (n = 90) with added long-distance links defining four extended hub regions. Similarly to the brain data, it is found that oscillators in the hub regions generate signals with larger low-frequency cycle amplitude fluctuations and clearer saturation to a lower correlation dimension compared to surrogates. The effect emerges more markedly close to criticality. The homology observed between the two systems despite profound differences in scale, coupling mechanism and dynamics appears noteworthy. These experimental results motivate further investigation into the heterogeneity of cortical non-linear dynamics in relation to connectivity and underline the ability for small networks of single-transistor oscillators to recreate collective phenomena arising in much more complex biological systems, potentially representing a future platform for modelling disease-related changes.

  17. Development of a core collection of Triticum and Aegilops species for improvement of wheat for activity against chronic diseases

    Santra Meenakshi

    2013-02-01

    Full Text Available Abstract Background The objective of this study was to develop a core collection of Triticum and Aegilops species as a resource for the identification and characterization of wheat lines with preventive activity against chronic diseases. Given that cancer is the leading cause of mortality in the world and shares risk factors with obesity, type-2 diabetes, and cardiovascular disease, and given that wheat has been reported to protect against these diseases, the core collection was developed based on cancer prevalence. Methods The Germplasm Resources Information Network (GRIN database was used to identify Triticum and Aegilops species grown in regions of the world that vary in cancer prevalence based on the International Agency for Cancer Research GLOBOCAN world map of cancer statistics (2008. Cancer incidence data drove variety selection with secondary consideration of ploidy, center of origin, and climate. Results Analysis indicated that the geographic regions from which wheat is considered to have originated have a lower incidence of cancer than other geographic regions (P Conclusions A diverse core collection of wheat germplasm has been established from a range of regions worldwide. This core collection will be used to identify wheat lines with activity against chronic diseases using anticancer activity as a screening tool.

  18. Effect of Silicon on Activity Coefficients of Platinum in Liquid Fe-Si, With Application to Core Formation

    Righter, K.; Pando, K.; Danielson, L. R.; Humayun, M.

    2017-01-01

    Earth's core contains approximately 10% of a light element that is likely a combination of S, C, Si, and O, with Si possibly being the most abundant light element. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE) in Fe liquids, and thus the partitioning behavior of those elements between core and mantle. The effect of Si can be small such as for Ni and Co, or large such as for Mo, Ge, Sb, As. The effect of Si on many siderophile elements is unknown yet could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of Pt (with Re and Ru in progress or planned) between metal and silicate melt. The results will be applied to Earth, for which we have excellent constraints on the mantle Pt concentrations.

  19. Controllable synthesis of ZnxCd1-xS@ZnO core-shell nanorods with enhanced photocatalytic activity.

    Xie, Shilei; Lu, Xihong; Zhai, Teng; Gan, Jiayong; Li, Wei; Xu, Ming; Yu, Minghao; Zhang, Yuan-Ming; Tong, Yexiang

    2012-07-17

    We report the synthesis of Zn(x)Cd(1-x)S@ZnO nanorod arrays via a facile two-step process and the implementation of these core-shell nanorods as an environmental friendly and recyclable photocatalyst for methyl orange degradation. The band gap of Zn(x)Cd(1-x)S@ZnO core-shell nanorods can be readily tunable by adjusting the ratio of Zn/Cd during the synthesis. These Zn(x)Cd(1-x)S@ZnO core-shell nanorods exhibit a high photocatalytic activity and good stability in the degradation of the methyl orange. Moreover, these films grown on FTO substrates make the collection and recycle of the photocatalyst easier. These findings may open new opportunities for the design of effective, stable, and easy-recyclable photocatalytic materials.

  20. The effect of trunk stabilization exercises with a swiss ball on core muscle activation in the elderly.

    Kim, Seong Gil; Yong, Min Sik; Na, Sang Su

    2014-09-01

    [Purpose] The purpose of this study was to investigate the effects of trunk stabilization exercise on the muscle EMG activations related to core stability. [Subjects and Methods] Fifteen elderly people in a geriatric hospital performed trunk stabilization exercises with a Swiss ball for 20 minutes five times per week for 8 weeks. Trunk muscle activations were measured using electromyography before and after the intervention. [Results] After the intervention, the muscle activations of the rectus abdominis, erector spinae, lateral low-back (quadratus lumborum and external oblique), and gluteus medius muscles increased significantly. [Conclusion] The trunk stabilization exercise with a Swiss ball significantly increased the muscle activities of the elderly.

  1. Overview on R and D and design activities for the ITER core charge exchange spectroscopy diagnostic system

    Biel, W., E-mail: w.biel@fz-juelich.de [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Baross, T. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Bourauel, P. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Dunai, D. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Durkut, M. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Erdei, G. [BME, EURATOM Association, PO Box 91, H-1521 Budapest (Hungary); Hawkes, N. [Association EURATOM/CCFE, OX14 3DB Abingdon (United Kingdom); Hellermann, M. von [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Hogenbirk, A. [Nuclear Research and Consultancy Group V.o.F., Petten (Netherlands); Jaspers, R. [Department of Applied Physics, Eindhoven University of Technology (Netherlands); Kiss, G. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Klinkhamer, F. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Koning, J.F. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Kotov, V.; Krasikov, Y.; Krimmer, A. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany)

    2011-10-15

    The ITER core charge exchange recombination spectroscopy (core CXRS) diagnostic system is designed to provide experimental access to various measurement quantities in the ITER core plasma such as ion densities, temperatures and velocities. The implementation of the approved CXRS diagnostic principle on ITER faces significant challenges: First, a comparatively low CXRS signal intensity is expected, together with a high noise level due to bremsstrahlung, while the requested measurement accuracy and stability for the core CXRS system go far beyond the level commonly achieved in present-day fusion experiments. Second, the lifetime of the first mirror surface is limited due to either erosion by fast particle bombardment or deposition of impurities. Finally, the hostile technical environment on ITER imposes challenging boundary conditions for the diagnostic integration and operation, including high neutron loads, electro-magnetic loads, seismic events and a limited access for maintenance. A brief overview on the R and D and design activities for the core CXRS system is presented here, while the details are described in parallel papers.

  2. Improved microbial growth inhibition activity of bio-surfactant induced Ag–TiO{sub 2} core shell nanoparticles

    Nithyadevi, D. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Kumar, P. Suresh [Thin Film and Nanomaterials Laboratory, Department of Physics, Bharathiar University, Coimbatore 641 046 (India); Mangalaraj, D., E-mail: dmraj800@yahoo.com [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Ponpandian, N.; Viswanathan, C. [Department of Nanoscience and Technology, Bharathiar University, Coimbatore 641 046 (India); Meena, P. [Department of Physics, PSGR Krishnammal college for women, Coimbatore 641 004 (India)

    2015-02-01

    Graphical abstract: - Highlights: • TiO{sub 2} nanoparticles were synthesized by hydrolysis process and Ag nanoparticles were prepared by using hydrazine reduction method. • Ag–TiO{sub 2} core shell nanoparticles were synthesized by reverse micelle method. • Coatings of TiO{sub 2} shell leads to decrease the usage of silver particles and also it reduces the release of silver ions from the matrix. • Optimum ratio of TiO{sub 2} particles: Ag atoms are needed for better antibacterial activity. • Sodium alginate (Bio-copolymer) induced core shell nanoparticles results 100% cell growth inhibition toward Staphylococcus aureus. - Abstract: Surfactant induced silver–titanium dioxide core shell nanoparticles within the size range of 10–50 nm were applied in the antibacterial agent to inhibit the growth of bacterial cells. The single crystalline silver was located in the core part of the composite powder and the titanium dioxide components were uniformly distributed in the shell part. HRTEM and XRD results indicated that silver was completely covered by titanium dioxide and its crystal structure was not affected after being coated by titanium dioxide. The effect of silver–titanium dioxide nanoparticles in the inhibition of bacterial cell growth was studied by means of disk diffusion method. The inhibition zone results reveal that sodium alginate induced silver–titanium dioxide nanoparticles exhibit 100% more antibacterial activity than that with cetyltrimethylbromide or without surfactant. UV–vis spectroscopic analysis showed a large concentration of silver was rapidly released into phosphate buffer solution (PBS) within a period of 1 day, with a much smaller concentration being released after this 1-day period. It was concluded that sodium alginate induced silver–titanium dioxide core shell nanoparticles could enhance long term cell growth inhibition in comparison with cetyltrimethylbromide or without surfactant. The surfactant mediated core shell

  3. Faulting processes in active faults - Evidences from TCDP and SAFOD drill core samples

    Janssen, C.; Wirth, R.; Wenk, H. -R.; Morales, L.; Naumann, R.; Kienast, M.; Song, S. -R.; Dresen, G. [UCB; (GFZ); (NTU)

    2014-08-20

    The microstructures, mineralogy and chemistry of representative samples collected from the cores of the San Andreas Fault drill hole (SAFOD) and the Taiwan Chelungpu-Fault Drilling project (TCDP) have been studied using optical microscopy, TEM, SEM, XRD and XRF analyses. SAFOD samples provide a transect across undeformed host rock, the fault damage zone and currently active deforming zones of the San Andreas Fault. TCDP samples are retrieved from the principal slip zone (PSZ) and from the surrounding damage zone of the Chelungpu Fault. Substantial differences exist in the clay mineralogy of SAFOD and TCDP fault gouge samples. Amorphous material has been observed in SAFOD as well as TCDP samples. In line with previous publications, we propose that melt, observed in TCDP black gouge samples, was produced by seismic slip (melt origin) whereas amorphous material in SAFOD samples was formed by comminution of grains (crush origin) rather than by melting. Dauphiné twins in quartz grains of SAFOD and TCDP samples may indicate high seismic stress. The differences in the crystallographic preferred orientation of calcite between SAFOD and TCDP samples are significant. Microstructures resulting from dissolution–precipitation processes were observed in both faults but are more frequently found in SAFOD samples than in TCDP fault rocks. As already described for many other fault zones clay-gouge fabrics are quite weak in SAFOD and TCDP samples. Clay-clast aggregates (CCAs), proposed to indicate frictional heating and thermal pressurization, occur in material taken from the PSZ of the Chelungpu Fault, as well as within and outside of the SAFOD deforming zones, indicating that these microstructures were formed over a wide range of slip rates.

  4. SASI ACTIVITY IN THREE-DIMENSIONAL NEUTRINO-HYDRODYNAMICS SIMULATIONS OF SUPERNOVA CORES

    Hanke, Florian; Mueller, Bernhard; Wongwathanarat, Annop; Marek, Andreas; Janka, Hans-Thomas, E-mail: fhanke@mpa-garching.mpg.de, E-mail: bjmuellr@mpa-garching.mpg.de, E-mail: annop@mpa-garching.mpg.de, E-mail: amarek@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2013-06-10

    The relevance of the standing accretion shock instability (SASI) compared to neutrino-driven convection in three-dimensional (3D) supernova-core environments is still highly controversial. Studying a 27 M{sub Sun} progenitor, we demonstrate, for the first time, that violent SASI activity can develop in 3D simulations with detailed neutrino transport despite the presence of convection. This result was obtained with the PROMETHEUS-VERTEX code with the same sophisticated neutrino treatment so far used only in one-dimensional and two-dimensional (2D) models. While buoyant plumes initially determine the nonradial mass motions in the postshock layer, bipolar shock sloshing with growing amplitude sets in during a phase of shock retraction and turns into a violent spiral mode whose growth is only quenched when the infall of the Si/SiO interface leads to strong shock expansion in response to a dramatic decrease of the mass accretion rate. In the phase of large-amplitude SASI sloshing and spiral motions, the postshock layer exhibits nonradial deformation dominated by the lowest-order spherical harmonics (l = 1, m = 0, {+-}1) in distinct contrast to the higher multipole structures associated with neutrino-driven convection. We find that the SASI amplitudes, shock asymmetry, and nonradial kinetic energy in three dimensions can exceed those of the corresponding 2D case during extended periods of the evolution. We also perform parameterized 3D simulations of a 25 M{sub Sun} progenitor, using a simplified, gray neutrino transport scheme, an axis-free Yin-Yang grid, and different amplitudes of random seed perturbations. They confirm the importance of the SASI for another progenitor, its independence of the choice of spherical grid, and its preferred growth for fast accretion flows connected to small shock radii and compact proto-neutron stars as previously found in 2D setups.

  5. The Enzyme-mimic Activity of Ferric Nano-Core Residing in Ferritin and Its Biosensing Applications

    Tang, Zhiwen; Wu, Hong J.; Zhang, Youyu; Li, Zhaohui; Lin, Yuehe

    2011-11-15

    Ferritins are nano-scale globular protein cages encapsulating a ferric core. They widely exist in animals, plants, and microbes, playing indispensable roles in iron homeostasis. Interestingly, our study clearly demonstrates that ferritin has an enzyme-mimic activity derived from its ferric nano-core, but not the protein cage. Further study revealed that the mimic-enzyme activity of ferritin is more thermally stable and pH-tolerant compared with horseradish peroxidase. Considering the abundance of ferritin in numerous organisms, this finding may indicate a new role of ferritin in antioxidant and detoxification metabolisms. In addition, as a natural protein-caged nanoparticle with an enzyme-mimic activity, ferritin is readily conjugated with biomolecules to construct nano-biosensors, thus holds promising potential for facile and biocompatible labeling for sensitive and robust bioassays in biomedical applications.

  6. Development of the W-band density profile and fluctuation reflectometer on EAST

    Wang, Y.M.; Gao, X., E-mail: xgao@ipp.ac.cn; Ling, B.L.; Zhang, S.B.; Zhang, T.; Han, X.; Liu, S.C.; Liu, Z.X.; Liu, Y.; Ti, A.

    2013-11-15

    Highlights: • A X-mode W-band reflectometer is designed and installed on Experimental Advanced Superconducting Tokamak (EAST) for the first time. • Both density profile and fluctuations can be measured by the newly developed reflectometer. • The core density profile has been measured in high magnetic field condition together with V-band reflectometer. • Sawtooth precursor has been measured by fluctuation reflectometer in the low magnetic field condition. -- Abstract: A X-mode polarized W-band reflectometer for plasma density profile and fluctuation measurement is designed and installed on EAST. In measuring the density profile, a voltage controlled oscillator (VCO) is used as the source, allowing a high temporal resolution measurement. The density profile in a plasma with high magnetic field (3.0 T) has been measured by combination of V- and W-band reflectometers. For fluctuation measurements, a frequency synthesizer is used instead of the VCO as a microwave source. The core density fluctuations during sawtooth activity are measured and analyzed.

  7. Using a Differential Emission Measure and Density Measurements in an Active Region Core to Test a Steady Heating Model

    Winebarger, Amy; Warren, Harry; Saar, Steve; Kashyap, Vinay

    2011-01-01

    The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high temperature active region loops close to equilibrium. In this paper, we couple observations of Active Region 10955 made with XRT and EIS on \\textit{Hinode} to test a simple steady heating model. First we calculate the differential emission measure of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3\\,MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6...

  8. Link of volcanic activity and climate change in Altai studied in the ice core from Belukha Mountain

    N. S. Malygina

    2013-01-01

    Full Text Available In the present research we discuss a role of volcanic activity in Altai thermal regime. Here we analyses the sulfate and temperature data reconstructed from the natural paleoarchive – ice core from the Belukha Mountain saddle. Sulfate ice-core reconstructions can serve as volcanic markers. The both – sulfate and temperature reconstructions – are for the last 750 years. As the characteristic of volcanic activity we consider Volcanic Explosivity Index (VEI, Dust Veil Index (DVI and Ice core volcanic index (IVI. The analysis was done using wavelet analysis and analysis of wavelet cross coherence and phase. As the result, we conclude that observed increases in the values of the indexes VEI, DVI, IVI basically correspond to decreases of temperature and increases of sulfate concentrations. This confirms the dependence of changes in the thermal regime of the Altai from volcanic activity. But in the 1750–1850 years period there is a delay of the changes in temperature with respect to the changes in volcanic activity. We suggest that it can be due to the superposition of the influence of solar and volcanic activity on changes in the thermal regime of Altai.

  9. Change of Muscle Activity as Well as Kinematic and Kinetic Parameters during Headers after Core Muscle Fatigue

    Stephan Becker

    2017-01-01

    Full Text Available In soccer, headers are a tactical measure and influenced by numerous factors. The goal of this study was to identify whether changes in kinematics and muscular activity, especially of the head-stabilizing muscles, occur during headers when the core musculature is fatigued. In two subgroups, muscular activity (12 amateur players, age 23.6 ± 4.2 years and kinematics and dynamics (29 amateur players, age 23.7 ± 2.8 years were examined during straight headers on a pendulum header. Data were collected before and after the core muscles were fatigued by an exercise program. Telemetric surface EMG, 3D acceleration sensor, force plate, and video recordings were used. Under fatigue, the activity of M. erector spinae and M. rectus abdominis was significantly reduced in the preparation phase of the header. The activity of M. sternocleidomastoideus was significantly increased during the jump phase, and the hip extension angle during maximum arched body tension was significantly reduced under fatigue. Jumping height, acceleration force impulse, and linear head acceleration were also significantly reduced. We conclude that fatigue of the core muscles affects the motion technique of the header and the activity of the muscle groups stabilizing the head. Therefore, the necessity of specific training in soccer should be emphasized from a medical-preventive point of view.

  10. Altered baseline brain activity in experts measured by amplitude of low frequency fluctuations (ALFF: a resting state fMRI study using expertise model of acupuncturists

    Minghao eDong

    2015-03-01

    Full Text Available It is well established that expertise modulates evoked brain activity in response to specific stimuli. Recently, researchers have begun to investigate how expertise influences the resting brain. Among these studies, most focused on the connectivity features within/across regions, i.e. connectivity patterns/strength. However, little concern has been given to a more fundamental issue whether or not expertise modulates baseline brain activity. We investigated this question using amplitude of low-frequency (<0.08Hz fluctuation (ALFF as the metric of brain activity and a novel expertise model, i.e. acupuncturists, due to their robust proficiency in tactile perception and emotion regulation. After the psychophysical and behavioral expertise screening procedure, 23 acupuncturists and 23 matched non-acupuncturists (NA were enrolled. Our results explicated higher ALFF for acupuncturists in the left ventral medial prefrontal cortex (VMPFC and the contralateral hand representation of the primary somatosensory area (SI (corrected for multiple comparisons. Additionally, ALFF of VMPFC was negatively correlated with the outcomes of the emotion regulation task (corrected for multiple comparisons. We suggest that our study may reveal a novel connection between the neuroplasticity mechanism and resting state activity, which would upgrade our understanding of the central mechanism of learning. Furthermore, by showing that expertise can affect the baseline brain activity as indicated by ALFF, our findings may have profound implication for functional neuroimaging studies especially those involving expert models, in that difference in baseline brain activity may either smear the spatial pattern of activations for task data or introduce biased results into connectivity-based analysis for resting data.

  11. Preparation, characterization and photocatalytic activities of ZrWMoO{sub 8}/Ag composites with core-shell structure

    Liu Qinqin, E-mail: liu_qin_qin@126.com [School of Materials Science and Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013 (China); Sun Shuai; Li Haohua; Yang Xiaofei; Shen Hao; Cheng Xiaonong; Dong Shubin [School of Materials Science and Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013 (China)

    2012-11-15

    ZrWMoO{sub 8} rods with negative thermal expansion and ZrWMoO{sub 8}/Ag composites with core-shell structure were first proved to exhibit photocatalytic activity under UV-irradiation. Highlights: Black-Right-Pointing-Pointer ZrWMoO{sub 8} rods with negative thermal expansion property were first studied for its photocatalytic activity. Black-Right-Pointing-Pointer ZrWMoO{sub 8}/Ag composites with core-shell structure were prepared using a simple reduction method. Black-Right-Pointing-Pointer Improved photocatalytic activity was found in the ZrWMoO{sub 8}/Ag heterostructures. Black-Right-Pointing-Pointer The ZrWMoO{sub 8}/Ag heterostructure promotes the separation of electron-hole pairs and enhances the photocatalytic activity. - Abstract: A novel photocatalytic ZrWMoO{sub 8}/Ag composite with core-shell structure was prepared. The composites were composed of ZrWMoO{sub 8} rods with negative thermal expansion (NTE) property as cores and Ag nanoparticles as shell. The resulting products were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV-visible spectrophotometer (UV-vis DRS). The results showed that ZrWMoO{sub 8} rods displayed not only negative thermal expansion but also photocatalytic efficiency toward Rhodamine B (RB) degradation under UV-irradiation. The as-prepared ZrWMoO{sub 8}/Ag composites exhibited a higher photocatalytic activity than that of pure ZrWMoO{sub 8}, thereby implying that the ZrWMoO{sub 8}/Ag interfaces promote the separation of photogenerated electron-hole pairs and enhance the photocatalytic activity.

  12. Fluctuation Analysis of Human Electroencephalogram

    Hwa, R C; Hwa, Rudolph C.; Ferree, Thomas C.

    2001-01-01

    The scaling behaviors of the human electroencephalogram (EEG) time series are studied using detrended fluctuation analysis. Two scaling regions are found in nearly every channel for all subjects examined. The scatter plot of the scaling exponents for all channels (up to 129) reveals the complicated structure of a subject's brain activity. Moment analyses are performed to extract the gross features of all the scaling exponents, and another universal scaling behavior is identified. A one-parameter description is found to characterize the fluctuation properties of the nonlinear behaviors of the brain dynamics.

  13. Monodisperse Ag@SiO2 core-shell nanoparticles as active inhibitors for marine anticorrosion applications.

    Zhang, Xin-Sheng; Wang, Jie-Xin; Xu, Ke; Le, Yuan; Chen, Jian-Feng

    2011-04-01

    Monodisperse Ag@SiO2 core-shell structured nanoparticles were firstly utilized as a novel corrosion inhibitor for marine anticorrosion applications. The related marine anticorrosion properties were evaluated with an electrochemical noise (ECN) analysis during 2 weeks of accelerated immersion tests in natural seawater with the addition of various inorganic salts and nutriments. The experimental results indicate that the corrosion activity is markedly reduced by nearly 1-3 orders of magnitude owing to the introduction of Ag@SiO2 core-shell nanoparticles into coating. The inhibition efficiency of corrosion can reach as high as about 99%. More importantly, such a coating exhibits an excellent long-term sustained marine anticorrosion effect. So it could be reasonably inferred that silver cores as active inhibitors effectively prevent the corrosion damage from microorganisms, while silica shells act as a good protection for silver nanoparticles, delay the release of silver ions, and also function as the corrosion inhibiting action for inorganic salts. Therefore, this would make monodisperse Ag@SiO2 core-shell nanoparticles a potential and promising corrosion inhibitor for developing future advanced multifunctional coatings.

  14. Coincident activation of NMDA and dopamine D1 receptors within the nucleus accumbens core is required for appetitive instrumental learning.

    Smith-Roe, S L; Kelley, A E

    2000-10-15

    The nucleus accumbens, a brain structure ideally situated to act as an interface between corticolimbic information-processing regions and motor output systems, is well known to subserve behaviors governed by natural reinforcers. In the accumbens core, glutamatergic input from its corticolimbic afferents and dopaminergic input from the ventral tegmental area converge onto common dendrites of the medium spiny neurons that populate the accumbens. We have previously found that blockade of NMDA receptors in the core with the antagonist 2-amino-5-phosphonopentanoic acid (AP-5; 5 nmol) abolishes acquisition but not performance of an appetitive instrumental learning task (Kelley et al., 1997). Because it is currently hypothesized that concurrent dopamine D(1) and glutamate receptor activation is required for long-term changes associated with plasticity, we wished to examine whether the dopamine system in the accumbens core modulates learning via NMDA receptors. Co-infusion of low doses of the D(1) receptor antagonist SCH-23390 (0.3 nmol) and AP-5 (0.5 nmol) into the accumbens core strongly impaired acquisition of instrumental learning (lever pressing for food), whereas when infused separately, these low doses had no effect. Infusion of the combined low doses had no effect on indices of feeding and motor activity, suggesting a specific effect on learning. We hypothesize that co-activation of NMDA and D(1) receptors in the nucleus accumbens core is a key process for acquisition of appetitive instrumental learning. Such an interaction is likely to promote intracellular events and gene regulation necessary for synaptic plasticity and is supported by a number of cellular models.

  15. Highly active dealloyed Cu@Pt core-shell electrocatalyst towards 2-propanol electrooxidation in acidic solution

    Poochai, Chatwarin

    2017-02-01

    Dealloyed Cu@Pt core-shell electrocatalyst was fabricated by cyclic co-electrodeposition and selective Cu dealloying (CCEd-sCuD) on carbon paper (CP), namely Cu@Pt/CP. The Cu@Pt/CP exhibited a core-shell structure comprising with a Cu-rich core and a Pt-rich shell. The crystalline phases of Pt/CP and Cu@Pt/CP were a face-centered cubic (fcc). The compressive lattice strain approximately 0.85% was found in the Cu@Pt/CP owing to a lattice mismatch between a core and a shell region. In the core-region, Cu was formed Pt-Cu alloy as major and copper oxide and also metallic copper as minor. The morphology and grain size of the Cu@Pt/CP displayed a porous spherical shape with 100 nm in diameter, while those of Pt/CP seemed to be a cubic shape with smaller diameter of 40 nm. In electrochemical and catalytic activity, the surface of Cu@Pt/CP had a larger electrochemical active surface area (ECSA) than that of Pt/CP due to a porous formation caused by Cu dealloying. It is not surprising that the Cu@Pt/CP showed higher catalytic activity and greater stability towards 0.5 M 2-propanol electrooxidation in 0.5 M H2SO4 in terms of peak current density (jp), peak potential (Ep), onset potential (Eonset), diffusion coefficient (D), and charge transfer resistance (Rct) which were caused by electronic structure modification, higher compressive lattice strain, and larger ECSA, compared with Pt/CP.

  16. Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

    Adamson, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator, so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents. The LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures, have limited solubility in the glass waste form, and represent a materials corrosion concern, such as halides and sulfate. Because this stream will recycle within WTP, these components will accumulate in the Melter Condensate

  17. High adenylyl cyclase activity and in vivo cAMP fluctuations in corals suggest central physiological role.

    Barott, K L; Helman, Y; Haramaty, L; Barron, M E; Hess, K C; Buck, J; Levin, L R; Tresguerres, M

    2013-01-01

    Corals are an ecologically and evolutionarily significant group, providing the framework for coral reef biodiversity while representing one of the most basal of metazoan phyla. However, little is known about fundamental signaling pathways in corals. Here we investigate the dynamics of cAMP, a conserved signaling molecule that can regulate virtually every physiological process. Bioinformatics revealed corals have both transmembrane and soluble adenylyl cyclases (AC). Endogenous cAMP levels in live corals followed a potential diel cycle, as they were higher during the day compared to the middle of the night. Coral homogenates exhibited some of the highest cAMP production rates ever to be recorded in any organism; this activity was inhibited by calcium ions and stimulated by bicarbonate. In contrast, zooxanthellae or mucus had >1000-fold lower AC activity. These results suggest that cAMP is an important regulator of coral physiology, especially in response to light, acid/base disturbances and inorganic carbon levels.

  18. Post-translational generation of constitutively active cores from larger phosphatases in the malaria parasite, Plasmodium falciparum: implications for proteomics

    Adams Brian

    2004-07-01

    Full Text Available Abstract Background Although the complete genome sequences of a large number of organisms have been determined, the exact proteomes need to be characterized. More specifically, the extent to which post-translational processes such as proteolysis affect the synthesized proteins has remained unappreciated. We examined this issue in selected protein phosphatases of the protease-rich malaria parasite, Plasmodium falciparum. Results P. falciparum encodes a number of Ser/Thr protein phosphatases (PP whose catalytic subunits are composed of a catalytic core and accessory domains essential for regulation of the catalytic activity. Two examples of such regulatory domains are found in the Ca+2-regulated phosphatases, PP7 and PP2B (calcineurin. The EF-hand domains of PP7 and the calmodulin-binding domain of PP2B are essential for stimulation of the phosphatase activity by Ca+2. We present biochemical evidence that P. falciparum generates these full-length phosphatases as well as their catalytic cores, most likely as intermediates of a proteolytic degradation pathway. While the full-length phosphatases are activated by Ca+2, the processed cores are constitutively active and either less responsive or unresponsive to Ca+2. The processing is extremely rapid, specific, and occurs in vivo. Conclusions Post-translational cleavage efficiently degrades complex full-length phosphatases in P. falciparum. In the course of such degradation, enzymatically active catalytic cores are produced as relatively stable intermediates. The universality of such proteolysis in other phosphatases or other multi-domain proteins and its potential impact on the overall proteome of a cell merits further investigation.

  19. Vertical profiles of dioxin-like and estrogenic activities associated with a sediment core from Tokyo Bay, Japan

    Kannan, K.; Villeneuve, D.L.; Yamashita, N.; Imagawa, T.; Hashimoto, S.; Miyazaki, A.; Giesy, J.P. [Michigan State University, East Lansing, MI (USA). Dept. of Zoology

    2000-09-01

    In vitro bioassays were used to measure dioxin-like and estrogenic activities associated with florisil fractions of extracts from a sediment core collected from Tokyo Bay, Japan. Florisil fractions 2(F2) and 3(F3) elicited significant dioxin-like responses in vitro. Dioxin-like activity of F2 samples were correlated with the vertical profile of PAH concentrations (R{sup 2} = 0.85). Contribution of PAHs to Ah receptor-mediated activities in sediments was greater than those by PCDDs/DFs, PCBs, and PCNs. The dioxin-like activity of F3 samples suggests the presence of relatively polar, Ah receptor-active compounds in the Tokyo Bay sediment core. Significant estrogenic activities, which may be related to the presence of certain estrogenic PAHs, were observed for F2 samples. Estrogen equivalents (E2-EQs) calculated from the concentrations and relative potencies of known estrogenic compounds in F2 were greater than bioassay-derived E2-EQs. This suggests that complex interactions between estrogenic and antiestrogenic compounds (PAHs, PCDD/DFs, and PCNs) may have modulated the activity. F3 samples were toxic to MVLN cells; therefore, their estrogenic activities could not be estimated. 27 refs., 4 figs., 3 tabs.

  20. Math starters 5- to 10-minute activities aligned with the common core math standards, grades 6-12

    Muschla, Judith A; Muschla, Erin

    2013-01-01

    A revised edition of the bestselling activities guide for math teachers Now updated with new math activities for computers and mobile devices-and now organized by the Common Core State Standards-this book includes more than 650 ready-to-use math starter activities that get kids quickly focused and working as soon as they enter the classroom. Ideally suited for any math curriculum, these high-interest problems spark involvement in the day's lesson, help students build skills, and allow teachers to handle daily management tasks without wasting valuable instructional time. A newly updated edit

  1. A Common Definition of the System Operators' Core Activities[Electric Power Transmission System Operator

    NONE

    2006-02-15

    In this report a common definition of the system operator's core activities in the Nordic countries is identified and also a list of non-core activities is introduced. As a starting point the common tasks for system responsibility as identified by Nordel has been used for the work. The term TSO (Transmission System Operator) is employed as a common denominator in the report. It is found out that the TSOs carry out common core activities in the roles as a transmission operator, a system operator and a balance settlement responsible. The core activities for the TSO as a transmission network operator are: Maintain the adequate transmission system in the long run and network development plan on the national as well as on the Nordic level using sophisticated analysis and planning methods and tools. Plan the transmission network on the national as well as on the Nordic level utilising new investments, renewal and maintenance of existing network components so that the network is secure to operate and adequate transmission capacity is guaranteed. Aim at timely network expansions using enhanced information exchange between the Nordic TSOs, and on the national level between the TSO and distribution and regional network operators, large consumers and large producers. Secure the technical compatibility with networks across the border and within a country by establishing connection requirements on the national level and ensuring that the national requirements are compatible across the Nordic power system. The core activities for the TSO as a system operator are: Define common technical requirements for the secure system operation using common planning, operation, connection and data exchange procedures. Secure the system operation with the operational planning for the following year by using information exchange between TSOs enabling the TSOs to make the best possible forecast of the global grid situation in order to assess the flows in their network and the available

  2. Core/shell Fe3O4/BiOI nanoparticles with high photocatalytic activity and stability

    Zheng, Liyun; Wang, Shuling; Zhao, Lixin; Zhao, Shuguo

    2016-11-01

    Core/shell Fe3O4/BiOI nanoparticles with BiOI sheath have been synthesized by a solvothermal reaction method and were characterized by transmission electron microscopy (TEM) with an energy dispersive spectrum (EDS), high-resolution TEM and X-ray diffraction (XRD). Their photocatalytic activities were evaluated by methylene blue (MB) under the simulated solar light. The results indicate that the spherical Fe3O4 particles were coated with BiOI sheath when the sample were synthesized at 160 °C with ethylene glycol and deionized water, forming a core/shell structure. The degradation rate of MB assisted with the core/shell Fe3O4/BiOI catalysts reached 98 % after 40-min irradiation. The catalytic performance enhancement of the core/shell Fe3O4/BiOI catalysts mainly attributes to the band structure that can improve the generation efficiency, separation and transfer process of the photo-induced electron-hole pairs and decrease their recombination. The magnetic Fe3O4 core not only contributes to the efficient separation of electron and holes, but also helps catalysts be collected conveniently using a magnet for reuse. After five repeated trials, the degradation rate of MB still maintains over 90 % and the saturated magnetization of the catalysts remains 51.5 emu/g, which indicate that the core/shell Fe3O4/BiOI nanoparticles have excellent photocatalytic stability and are recyclable for decomposing organic pollutants under visible light irradiation.

  3. Fluctuations in phenolic content, ascorbic acid and total carotenoids and antioxidant activity of fruit beverages during storage

    C. Castro-López

    2016-09-01

    Full Text Available Stability of the total phenolic content, ascorbic acid, total carotenoids and antioxidant activity in eight fruit beverages was analyzed. The influence of storage temperature (4, 8 and 11 °C during the product shelf-life (20 days was evaluated. Pomegranate Juice presented the highest values for antioxidant activity by DPPH·− assay (552.93 ± 6.00 GAE μg mL−1, total carotenoids (3.18 ± 0.11 βCE μg mL−1, and total phenolic content (3967.07 ± 2.47 GAE μg mL−1; while Splash Blend recorded the highest levels of ascorbic acid (607.39 ± 2.13 AAE μg mL−1. The antioxidant capacity was stable at 4 and 8 °C for the first 8 days of storage; while carotenoids and ascorbic acid were slightly degraded through the storage time, possibly due to oxidation and/or reactions with other compounds. The results suggest that the observed variation during testing could be related to storage conditions of the final product.

  4. Disturbed spontaneous brain activity pattern in patients with primary angle-closure glaucoma using amplitude of low-frequency fluctuation: a fMRI study

    Huang X

    2015-07-01

    Full Text Available Xin Huang,1,* Yu-Lin Zhong,1,* Xian-Jun Zeng,2 Fuqing Zhou,2 Xin-Hua Liu,1 Pei-Hong Hu,1 Chong-Gang Pei,1 Yi Shao,1 Xi-Jian Dai21Department of Ophthalmology, 2Department of Radiology, The First Affiliated Hospital of Nanchang University, Nangchang, Jiangxi, People’s Republic of China*These authors contributed equally to this workObjective: The aim of this study is to use amplitude of low-frequency fluctuation (ALFF as a method to explore the local features of spontaneous brain activity in patients with primary angle -closure glaucoma (PACG and ALFFs relationship with the behavioral performances.Methods: A total of twenty one patients with PACG (eight males and 13 females, and twenty one healthy subjects (nine males and twelve females closely matched in age, sex, and education, each underwent a resting-state functional magnetic resonance imaging scan. The ALFF method was used to assess the local features of spontaneous brain activity. The correlation analysis was used to explore the relationships between the observed mean ALFF signal values of the different areas in PACG patients and the thickness of the retinal nerve fiber layer (RNFL. Results: Compared with the healthy subjects, patients with PACG had significant lower ALFF areas in the left precentral gyrus, bilateral middle frontal gyrus, bilateral superior frontal gyrus, right precuneus, and right angular gyrus, and higher areas in the right precentral gyrus. In the PACG group, there were significant negative correlations between the mean ALFF signal value of the right middle frontal gyrus and the left mean RNFL thickness (r=-0.487, P=0.033, and between the mean ALFF signal value of the left middle frontal gyrus and the right mean RNFL thickness (r=-0.504, P=0.020. Conclusion: PACG mainly involved in the dysfunction in the frontal lobe, which may reflect the underlying pathologic mechanism of PACG.Keywords: angle-closure glaucoma, amplitude of low-frequency fluctuation, functional

  5. Preparation of AgBr@SiO{sub 2} core@shell hybrid nanoparticles and their bactericidal activity

    Li, Yuanyuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Yang, Lisu [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Henna Sports School, Zhengzhou 450045 (China); Zhao, Yanbao, E-mail: yanbaozhao@126.com [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie; Sun, Lei; Luo, Huajuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2013-04-01

    AgBr@SiO{sub 2} core@shell hybrid nanoparticles (NPs) were successfully prepared by sol-gel method. Their morphology and structure were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The hybrid NPs are predominantly spherical in shape, with an average diameter of 180–200 nm, and each NP contains one inorganic core. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the hybrid NPs were examined against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), respectively. Results indicated that the AgBr@SiO{sub 2} NPs had excellent antibacterial activity. - Highlights: ► Presents a novel antibacterial agent “AgBr@ SiO{sub 2} NPs”. ► AgBr@SiO{sub 2} hybrid NPs could provide long-term antimicrobial effect. ► AgBr@SiO{sub 2} hybrid NPs have excellent antibacterial activity.

  6. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    ) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity......Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD...... within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared...

  7. Abnormal intrinsic brain activity in amnestic mild cognitive impairment revealed by amplitude of low-frequency fluctuation: a resting-state functional magnetic resonance imaging study

    XI Qian; ZHAO Xiao-hu; WANG Pei-jun; GUO Qi-hao; HE Yong

    2013-01-01

    Background Previous studies have shown that brain functional activity in the resting state is impaired in Alzheimer's disease (AD) patients.However,alterations in intrinsic brain activity patterns in mild cognitive impairment (MCI) patients are poorly understood.This study aimed to explore the differences in regional intrinsic activities throughout the whole brain between aMCI patients and controls.Methods In the present study,resting-state functional magnetic resonance imaging (fMRI) was performed on 18 amnestic MCI (aMCI) patients,18 mild AD patients and 20 healthy elderly subjects.And amplitude of low-frequency fluctuation (ALFF) method was used.Results Compared with healthy elderly subjects,aMCI patients showed decreased ALFF in the right hippocampus and parahippocampal cortex,left lateral temporal cortex,and right ventral medial prefrontal cortex (vMPFC) and increased ALFF in the left temporal-parietal junction (TPJ) and inferior parietal Iobule (IPL).Mild AD patients showed decreased ALFF in the left TPJ,posterior IPL (plPL),and dorsolateral prefrontal cortex compared with aMCI patients.Mild AD patients also had decreased ALFF in the right posterior cingulate cortex,right vMPFC and bilateral dorsal MPFC (dMPFC) compared with healthy elderly subjects.Conclusions Decreased intrinsic activities in brain regions closely related to episodic memory were found in aMCI and AD patients.Increased TPJ and IPL activity may indicate compensatory mechanisms for loss of memory function in aMCI patients.These findings suggest that the fMRI based on ALFF analysis may provide a useful tool in the study of aMCI patients.

  8. Identification of a Small Molecular Anti - HIV - 1 Compound that Interferes with Formation of the Fusion - active gp41 Core

    2001-01-01

    The human immunodeficiency virus type 1 (HIV - 1 ) envelope glycoprotein gp41 plays a critical role in the fusion of viral and target cell membranes. The gp41 extracellular domain, which contains fusion peptide (FP), N - and C - terminal hydrophobic heptad repeats (NHR and CHR, respectively). Peptides derived from NHR and CHR regions,designated N- and C- peptides, respectively, can interact with each other to form a six - stranded coiled - coil domain, representing the fusion-active gp41 core. Our previous studies demonstrated that the C- peptides have potent inhibitory activity against HIV- 1 infection.These peptides inhibit HIV- 1 -mediated membrane fusion by binding to NHR regions for preventing the formation of fusion- active gp41 core. One of the C - peptides, T - 20, which is in the phase Ⅲ clinical trails, is expected to become the first peptide HIV fusion inhibitory drug in the near future. However, this peptide HIV fusion inhibitor lacks oral availability and is sensitive to the proteolytic digestion.Therefore, it is essential to develop small molecular non -peptide HIV fusion inhibitors having similar mechanism of action as the C- peptides. We have established an ELISA- based screening assay using a unique monoclonal antibody, NC- 1, which can specifically bind to a conformational epitope on the gp41 core domain. Using this screening assay, we have identified a small molecular anti- HIV- 1 compound,named ADS-Jl, which inhibits HIV- 1- mediated membrane fusion by blocking the interaction between the NHR and CHR regions to form the fusion - active gp41 core. This compound will be used as a lead to design and develop novel HIV fusion inhibitors as new drugs for the treatment of HIV infection and/or AIDS.

  9. Core Practices and Pedagogies of Teacher Education: A Call for a Common Language and Collective Activity

    McDonald, Morva; Kazemi, Elham; Kavanagh, Sarah Schneider

    2013-01-01

    Currently, the field of teacher education is undergoing a major shift--a turn away from a predominant focus on specifying the necessary knowledge for teaching toward specifying teaching practices that entail knowledge and doing. In this article, the authors suggest that current work on K-12 core teaching practices has the potential to shift…

  10. Examining English Language Arts Common Core State Standards Instruction through Cultural Historical Activity Theory

    Barrett-Tatum, Jennifer

    2015-01-01

    The English Language Arts Common Core State Standards and corresponding assessments brought about many changes for educators, their literacy instruction, and the literacy learning of their students. This study examined the day-to-day literacy instruction of two primary grade teachers during their first year of full CCSS implementation. Engestr?m's…

  11. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice.

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-03-01

    Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4-6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.

  12. Quantifying economic fluctuations

    Stanley, H. Eugene; Nunes Amaral, Luis A.; Gabaix, Xavier; Gopikrishnan, Parameswaran; Plerou, Vasiliki

    2001-12-01

    This manuscript is a brief summary of a talk designed to address the question of whether two of the pillars of the field of phase transitions and critical phenomena-scale invariance and universality-can be useful in guiding research on interpreting empirical data on economic fluctuations. Using this conceptual framework as a guide, we empirically quantify the relation between trading activity-measured by the number of transactions N-and the price change G( t) for a given stock, over a time interval [ t, t+Δ t]. We relate the time-dependent standard deviation of price changes-volatility-to two microscopic quantities: the number of transactions N( t) in Δ t and the variance W2( t) of the price changes for all transactions in Δ t. We find that the long-ranged volatility correlations are largely due to those of N. We then argue that the tail-exponent of the distribution of N is insufficient to account for the tail-exponent of P{ G> x}. Since N and W display only weak inter-dependency, our results show that the fat tails of the distribution P{ G> x} arises from W. Finally, we review recent work on quantifying collective behavior among stocks by applying the conceptual framework of random matrix theory (RMT). RMT makes predictions for “universal” properties that do not depend on the interactions between the elements comprising the system, and deviations from RMT provide clues regarding system-specific properties. We compare the statistics of the cross-correlation matrix C-whose elements Cij are the correlation coefficients of price fluctuations of stock i and j-against a random matrix having the same symmetry properties. It is found that RMT methods can distinguish random and non-random parts of C. The non-random part of C which deviates from RMT results, provides information regarding genuine collective behavior among stocks. We also discuss results that are reminiscent of phase transitions in spin systems, where the divergent behavior of the response function at

  13. Thermal-mechanical analysis of actively cooled folded core sandwich panels%主动冷却皱褶芯材夹层板的热力分析

    周晨; 王志瑾; 支骄杨

    2014-01-01

    A multifunctional sandwich panel with folded cellular cores was proposed for actively cooled load-bearing components in aerospace thermal protection systems. Thermal-mechanical responses of V-type and M-type folded core sandwich panels subjected to forced convection using kerosene as a coolant were studied numerically. First, a 3D fluid-solid coupling model was established and the temperature fields of fluid and structure were computed using the conjugate heat transfer model. Subsequently, the thermal stress and deformation of structure were obtained via sequential coupling method. The results show that the heat transfer perform-ances of folded core sandwich panels are evidently improved through active cooling. The temperature increases along the flow direc-tion and presents a periodic fluctuation. Heat convection is reinforced due to the folds which also cause serious stress concentrations. Cell topology and geometric dimensions have certain influences on the heat transfer characteristics and thermal structural behavior of the active cooled panels. A M-type folded core sandwich panel is superior to a V-type one for a much less severe stress concentra-tion.%提出了一种将皱褶芯材夹层板与主动冷却相结合的承载-热防护一体化结构形式。以煤油为冷却液,在强迫对流条件下,采用数值仿真方法对V-型和M-型皱褶芯材夹层板的热力响应进行了研究。首先,建立了主动冷却皱褶芯材夹层板的三维流固耦合模型,应用共轭传热数值计算方法,求解获得了冷却液和结构的温度场;采用顺序耦合求解,得到了相应的结构应力场和变形场。结果表明,实施主动冷却后皱褶结构的换热性能明显提高;沿流向温度上升,并呈现周期性波动;结构的皱褶在加强对流换热的同时,也导致了应力集中。芯材胞元拓扑构型及几何尺寸对结构的换热性能和应力应变具有一定程度的影响。与V-型相比

  14. Fluctuation relations for spintronics.

    López, Rosa; Lim, Jong Soo; Sánchez, David

    2012-06-15

    Fluctuation relations are derived in systems where the spin degree of freedom and magnetic interactions play a crucial role. The form of the nonequilibrium fluctuation theorems relies on the assumption of a local balance condition. We demonstrate that in some cases the presence of magnetic interactions violates this condition. Nevertheless, fluctuation relations can be obtained from the microreversibility principle sustained only at equilibrium as a symmetry of the cumulant generating function for spin currents. We illustrate the spintronic fluctuation relations for a quantum dot coupled to partially polarized helical edge states.

  15. Comparison of antibacterial activities of Ag@TiO2 and Ag@SiO2 core-shell nanoparticles

    Dhanalekshmi, K. I.; Meena, K. S.

    2014-07-01

    Core-shell type Ag@TiO2 nanoparticles were prepared by one pot simultaneous reduction of AgNO3 and hydrolysis of Ti (IV) isopropoxide and Ag@SiO2 core-shell nanoparticles were prepared by Stober's method. They were characterized by absorption, XRD, and HR-TEM techniques. XRD patterns show the presence of anatase form of TiO2 and amorphous form of SiO2 and the noble metal (Ag). High resolution transmission electron microscopy measurements revealed that their size is below 50 nm. The antibacterial properties of Ag@TiO2 and Ag@SiO2 core-shell nanoparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were examined by the agar diffusion method. As a result E. coli and S. aureus were shown to be substantially inhibited by Ag@TiO2 and Ag@SiO2 core-shell nanoparticles. These results demonstrated that TiO2 and SiO2 supported on the surface of Ag NPs without aggregation was proved to have enhanced antibacterial activity.

  16. Comparison of antibacterial activities of Ag@TiO2 and Ag@SiO2 core-shell nanoparticles.

    Dhanalekshmi, K I; Meena, K S

    2014-07-15

    Core-shell type Ag@TiO2 nanoparticles were prepared by one pot simultaneous reduction of AgNO3 and hydrolysis of Ti (IV) isopropoxide and Ag@SiO2 core-shell nanoparticles were prepared by Stober's method. They were characterized by absorption, XRD, and HR-TEM techniques. XRD patterns show the presence of anatase form of TiO2 and amorphous form of SiO2 and the noble metal (Ag). High resolution transmission electron microscopy measurements revealed that their size is below 50 nm. The antibacterial properties of Ag@TiO2 and Ag@SiO2 core-shell nanoparticles against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were examined by the agar diffusion method. As a result E. coli and S. aureus were shown to be substantially inhibited by Ag@TiO2 and Ag@SiO2 core-shell nanoparticles. These results demonstrated that TiO2 and SiO2 supported on the surface of Ag NPs without aggregation was proved to have enhanced antibacterial activity.

  17. One-pot synthesis of Pd-Pt@Pd core-shell nanocrystals with enhanced electrocatalytic activity for formic acid oxidation

    Yuan, Qiang

    2014-01-01

    Well-defined Pd-Pt@Pd core-shell nanocrystals with a Pd-Pt alloy core and a conformal Pd shell of ~2-3 nm were directly synthesized through a one-pot, aqueous solution approach without any preformed Pd or Pt seeds. These Pd-Pt@Pd core-shell nanocrystals show an enhanced electrocatalytic activity for formic acid oxidation compared with commercial Pd black. This journal is © 2014 The Royal Society of Chemistry.

  18. Miktoarm core-crosslinked star copolymers with biologically active moieties on peripheries

    Javakhishvili, Irakli; Hvilsted, Søren

    2010-01-01

    Miktoarm core-crosslinked star (CCS) copolymers featuring hydrophobic inner compartment based on poly(epsilon-caprolactone) (PCL), and hydrophilic multivalent exterior consisting of L-lysine dendritic wedges and estradiol or ferrocene moieties have been synthesized. Ring-opening polymerization (R...... dimethacrylate (BDMA) results in miktoarm CCS copolymers. Elucidation of the structure and composition of the intermediate and final products demonstrates effectiveness, versatility, and high degree of control displayed by the proposed synthetic sequence....

  19. Mineral Physics Research on Earth's Core and UTeach Outreach Activities at UT Austin

    Lin, J.; Wheat, A. J.

    2011-12-01

    Comprehension of the alloying effects of major candidate light elements on the phase diagram and elasticity of iron addresses pressing issues on the composition, thermal structures, and seismic features of the Earth's core. Integrating this mineral physics research with the educational objectives of the CAREER award was facilitated by collaboration with the University of Texas at Austin's premier teaching program, UTeach. The UTeach summer outreach program hosts three one-week summer camps every year exposing K-12th graders to university level academia, emphasizing math and science initiatives and research. Each week of the camp either focuses on math, chemistry, or geology. Many of the students were underrepresented minorities and some required simultaneous translation; this is an effect of the demographics of the region, and caused some language barrier challenges. The students' opportunity to see first-hand what it is like to be on a university campus, as well as being in a research environment, such as the mineral physics lab, helps them to visualize themselves in academia in the future. A collection of displayable materials with information about deep-Earth research were made available to participating students and teachers to disseminate accurate scientific knowledge and enthusiasm. These items included a diamond anvil cell and diagrams of the diamond crystal structure, the layers of the Earth, and the phases of carbon to show that one element can have very different physical properties purely based on differences in structure. The students learned how advanced X-ray and optical laser spectroscopies are used to study properties of planetary materials in the diamond anvil cell. Stress was greatly placed on the basic mathematical relationship between force, area, and pressure, the fundamental principle involved with diamond anvil cell research. Undergraduate researchers from the lab participated in the presentations and hands-on experiments, and answered any

  20. [Effects of Citric Acid on Activation and Methylation of Mercury in the Soils of Water-Level-Fluctuating Zone of the Three Gorges.Reservoir].

    Qin, Cai-qing; Liang, Li; You, Rui; Deng, Han; Wang, Ding-yong

    2015-12-01

    To investigate effects of the main component of vegetation root exudates-citric acid on activation and methylation of mercury in the soil of water-level-fluctuating zone (WLFZ) of the Three Gorges Reservoir area, simulation experiments were conducted by extracting and cultivating soil with different concentrations of citric acid. The results showed that after adding citric acid, the total mercury content in leaching solution before reaching peak were higher than that of the control, and increased with the increase of citric acid concentrations. The maximum amount of mercury complexes increased initially and then reached plateaus with the percentage against the total mercury in soil of 1.03%, 1.67%, 1.99%, 2.47%, 2.68%, 2.73% and 2.73% for different citric acid concentrations (0, 1, 2, 4, 5, 6 and 8 mmol · L⁻¹). In addition, concentrations of methylmercury ( MeHg) in soil remained stable in the first 3 hours, and then increased accompanying with the increasing rate rising with the concentration of citric acid ( besides the control group) . This result indicated that citric acid probably could promote the transformation process from inorganic mercury to MeHg in soil. which increased with the concentration of citric acid.

  1. Correlation and spectral measurements of fluctuating pressures and velocities in annular turbulent flow. [PWR; BWR

    Wilson, R.J.; Jones, B.G.; Roy, R.P.

    1980-02-01

    An experimental study of the fluctuating velocity field, the fluctuating static wall pressure and the in-stream fluctuating static pressure in an annular turbulent air flow system with a radius ratio of 4.314 has been conducted. The study included direct measurements of the mean velocity profile, turbulent velocity field; fluctuating static wall pressure and in-stream fluctuating static pressure from which the statistical values of the turbulent intensity levels, power spectral densities of the turbulent quantities, the cross-correlation between the fluctuating static wall pressure and the fluctuating static pressure in the core region of the flow and the cross-correlation between the fluctuating static wall pressure and the fluctuating velocity field in the core region of the flow were obtained.

  2. HDAC Activity Is Required for Efficient Core Promoter Function at the Mouse Mammary Tumor Virus Promoter

    Sang C. Lee

    2011-01-01

    Full Text Available Histone deacetylases (HDACs have been shown to be required for basal or inducible transcription at a variety of genes by poorly understood mechanisms. We demonstrated previously that HDAC inhibition rapidly repressed transcription from the mouse mammary tumor virus (MMTV promoter by a mechanism that does not require the binding of upstream transcription factors. In the current study, we find that HDACs work through the core promoter sequences of MMTV as well as those of several cellular genes to facilitate transcriptional initiation through deacetylation of nonhistone proteins.

  3. Magnetic Fluctuation Measurement in Sino United Spherical Tokamak Plasma

    LIU Fei; WANG Wen-Hao; HE Ye-Xi; LIU Jun; TAN Yi; XIE Li-Feng; ZENG Long

    2007-01-01

    To investigate the magnetic fluctuations and for further transport study, the poloidal and radial magnetic field measurement is conducted on the Sino United Spherical Tokamak (SUNIST). Auto-power spectral density indicates that the magnetic fluctuation energy mainly concentrates in the frequency region lower than 10kHz. The magnetic field oscillations, which are characterized by harmonic frequencies of 40 kHz, are observed in the scrapeoff layer; by contrast, in the plasma core, the magnetic fluctuations are of Gaussian type. The time-frequency profiles show that the poloidal magnetic fluctuations are temporally intermittent. The autocorrelation calculation indicates that the fluctuations in decorrelation time vary between the core and the edge.

  4. ANTI-TUMOR ACTIVITY AND IMMUNE RESPONSES INDUCED BY HUMAN CANCER-ASSOCIATED MUCIN CORE PEPTIDE

    Ma Yunguo; Yuan Mei; Fei Lihua; Li Li

    1998-01-01

    Objective: To investigate the immune responses induced by apomucin which is a mixture of mucin core peptide, in mice for elucidating the role of mucin core peptide in the modulation of cancers. Methods:Apomucin was isolated from human pancreatic cancer cell line SW1990. The mice were immunized with this apomucin (10μg/time×6) plus DETOX. Results: When immunized, all mice developed delayed-type hypersensitivity (DTH) after challenged with apomucin or synthetic peptide MUC-2 or MUC-3, while the mice immunized with apomucin alone did not develop DTH.No antibodies were detected by ELISA after immunization. When the spleen cells of vaccinated mice were cocultured with this apomucin (10-50μg/ml) and rhIL-2(50U/ml) in vitro, the proliferated lymphocytes showed cytotoxicity against human cancer cells, including colon cancer, gastric cancer, pancreatic cancer and leukemia as measured by Cr-51 release assay. Antibodies against MUC-2 and MUC-3 could block the cytotoxicity. Conclusion: It was identified that a vaccine combined of apomucin and immune adjuvant DETOX can induce cellular immune response and anti-tumor cytotoxicity in mice.

  5. Au@Co0.4S core-shell nanoparticles: synthesis, characterization and evaluation of photocatalytic activity

    Warjri, Wandibahun; Negi, Devendra P. S.

    2016-09-01

    In the present work, Au@Co0.4S core-shell nanoparticles were synthesized and characterized by energy-dispersive x-ray spectroscopy, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy. The photocatalytic activity of the as-prepared core-shell nanoparticles was evaluated by studying the degradation of methyl orange (MO) spectrophotometerically under visible light irradiation. Under optimum experimental conditions, 68.9% of the dye was degraded during 50 min of irradiation. Control experiments showed negligible degradation of MO in the absence of the photocatalyst under visible light irradiation. A good correlation was obtained between the concentration of the dye adsorbed on the surface of the Au@Co0.4S core-shell nanoparticles and its degradation efficiency. The as-prepared nanoparticles showed good recyclability for the degradation of MO. The mechanistic studies suggested that the valence band holes of the Co0.4S nanoparticles were scavenged by the MO molecules resulting in the degradation of the dye.

  6. Continuous information flow fluctuations

    Rosinberg, Martin Luc; Horowitz, Jordan M.

    2016-10-01

    Information plays a pivotal role in the thermodynamics of nonequilibrium processes with feedback. However, much remains to be learned about the nature of information fluctuations in small-scale devices and their relation with fluctuations in other thermodynamics quantities, like heat and work. Here we derive a series of fluctuation theorems for information flow and partial entropy production in a Brownian particle model of feedback cooling and extend them to arbitrary driven diffusion processes. We then analyze the long-time behavior of the feedback-cooling model in detail. Our results provide insights into the structure and origin of large deviations of information and thermodynamic quantities in autonomous Maxwell's demons.

  7. Hadronic Correlations and Fluctuations

    Koch, Volker

    2008-10-09

    We will provide a review of some of the physics which can be addressed by studying fluctuations and correlations in heavy ion collisions. We will discuss Lattice QCD results on fluctuations and correlations and will put them into context with observables which have been measured in heavy-ion collisions. Special attention will be given to the QCD critical point and the first order co-existence region, and we will discuss how the measurement of fluctuations and correlations can help in an experimental search for non-trivial structures in the QCD phase diagram.

  8. Spatial fluctuation theorem

    Pérez-Espigares, Carlos; Redig, Frank; Giardinà, Cristian

    2015-08-01

    For non-equilibrium systems of interacting particles and for interacting diffusions in d-dimensions, a novel fluctuation relation is derived. The theorem establishes a quantitative relation between the probabilities of observing two current values in different spatial directions. The result is a consequence of spatial symmetries of the microscopic dynamics, generalizing in this way the Gallavotti-Cohen fluctuation theorem related to the time-reversal symmetry. This new perspective opens up the possibility of direct experimental measurements of fluctuation relations of vectorial observables.

  9. Spontaneous brain activity in chronic smokers revealed by fractional amplitude of low frequency fluctuation analysis: a resting state functional magnetic resonance imaging study

    Chu Shuilian; Xiao Dan; Wang Shuangkun; Peng Peng; Xie Teng; He Yong; Wang Chen

    2014-01-01

    Background Nicotine is primarily rsponsible for the highly addictive properties of cigarettes.Similar to other substances,nicotine dependence is related to many important brain regions,particular in mesolimbic reward circuit.This study was to further reveal the alteration of brain function activity during resting state in chronic smokers by fractional amplitude of low frequency fluctuation (fALFF) based on functional magnetic resonance imaging (fMRI),in order to provide the evidence of neurobiological mechanism of smoking.Methods This case control study involved twenty healthy smokers and nineteen healthy nonsmokers recruited by advertisement.Sociodemographic,smoking related characteristics and fMRI images were collected and the data analyzed.Results Compared with nonsmokers,smokers showed fALFF increased significantly in the left middle occipital gyrus,left limbic lobe and left cerebellum posterior lobe but decreases in the right middle frontal gyrus,right superior temporal gyrus,right extra nuclear,left postcentral gyrus and left cerebellum anterior lobe (cluster size >100 voxels).Compared with light smokers (pack years ≤20),heavy smokers (pack years >20) showed fALFF increased significantly in the right superior temporal gyrus,right precentral gyrus,and right occipital lobe/cuneus but decreased in the right/left limbic lobe/cingulate gyrus,right/left frontal lobe/sub gyral,right/left cerebellum posterior lobe (cluster size >50 voxels).Compared with nonsevere nicotine dependent smokers (Fagerstr(o)m test for nicotine dependence,score ≤6),severe nicotine dependent smokers (score >6) showed fALFF increased significantly in the right/left middle frontal gyrus,right superior frontal gyrus and left inferior parietal lobule but decreased in the left limbic lobe/cingulate gyrus (duster size >25 voxels).Conclusions In smokers during rest,the activity of addiction related regions were increased and the activity of smoking feeling,memory,related regions were

  10. Status of the R&D activities to the design of an ITER core CXRS diagnostic system

    Mertens, Philippe, E-mail: ph.mertens@fz-juelich.de [Institute of Energy and Climate Research IEK-4 (Plasma Physics), Forschungszentrum Jülich (FZJ), Trilateral Euregio Cluster, D-52425 Jülich (Germany); Castaño Bardawil, David A. [Institute of Energy and Climate Research IEK-4 (Plasma Physics), Forschungszentrum Jülich (FZJ), Trilateral Euregio Cluster, D-52425 Jülich (Germany); Baross, Tétény [Wigner Research Centre for Physics (Wigner RCP), HU-1121 Budapest (Hungary); Biel, Wolfgang; Friese, Sebastian [Institute of Energy and Climate Research IEK-4 (Plasma Physics), Forschungszentrum Jülich (FZJ), Trilateral Euregio Cluster, D-52425 Jülich (Germany); Hawkes, Nick [Culham Centre for Fusion Energy (CCFE), Culham OX14 3DB (United Kingdom); Jaspers, Roger J.E. [Eindhoven University of Technology (TU/e), PO Box 513, NL-5600 MB Eindhoven (Netherlands); Kotov, Vladislav; Krasikov, Yury; Krimmer, Andreas; Litnovsky, Andrey; Marchuk, Oleksander; Neubauer, Olaf [Institute of Energy and Climate Research IEK-4 (Plasma Physics), Forschungszentrum Jülich (FZJ), Trilateral Euregio Cluster, D-52425 Jülich (Germany); Offermanns, Guido [Zentralinstitut für Engineering, Elektronik und Analytik ZEA-1 (Engineering and Technology), FZJ, Trilateral Euregio Cluster, D-52425 Jülich (Germany); Panin, Anatoly [Institute of Energy and Climate Research IEK-4 (Plasma Physics), Forschungszentrum Jülich (FZJ), Trilateral Euregio Cluster, D-52425 Jülich (Germany); and others

    2015-10-15

    Highlights: • The CXRS diagnostic for the core plasma of ITER will provide observation of the dedicated diagnostic beam (DNB) over a wide radial range, roughly r/a = 0.7 to 0. • A high performance (étendue × transmission, dynamic range) is expected for the port plug system since the beam attenuation is large and the background light omnipresent. • The design is particularly challenging in view of the ITER environment, especially with respect to the first mirror which faces the plasma. • The current status of development is presented by detailing several sub-systems before a four years design phase under an FPA between F4E and the ITER core CXRS Consortium (IC3). - Abstract: The CXRS (Charge-eXchange Recombination Spectroscopy) diagnostic for the core plasma of ITER will be designed to provide observation of the dedicated diagnostic beam (DNB) over a wide radial range, roughly from a normalised radius r/a = 0.7 to close to the plasma axis. The collected light will be transported through the Upper Port Plug #3 (UPP3) to a bundle of fibres and ultimately to a set of remote spectrometers. The design is particularly challenging in view of the ITER environment of particle, heat and neutron fluxes, temperature cycles, electromagnetic loads, vibrations, expected material degradation and fatigue, constraints against tritium penetration, integration in the plug and limited opportunities for maintenance. Moreover, a high performance (étendue × transmission, dynamic range) is expected for the port plug system since the beam attenuation is large and the background light omnipresent, especially in terms of bremsstrahlung, line radiation and reflections. The present contribution will give an overview of the current status and activities which deal with the core CXRS system, summarising the investigations which have taken place before entering the actual development and design phase.

  11. Allosteric regulation of helicase core activities of the DEAD-box helicase YxiN by RNA binding to its RNA recognition motif.

    Samatanga, Brighton; Andreou, Alexandra Z; Klostermeier, Dagmar

    2017-01-23

    DEAD-box proteins share a structurally similar core of two RecA-like domains (RecA_N and RecA_C) that contain the conserved motifs for ATP-dependent RNA unwinding. In many DEAD-box proteins the helicase core is flanked by ancillary domains. To understand the regulation of the DEAD-box helicase YxiN by its C-terminal RNA recognition motif (RRM), we investigated the effect of RNA binding to the RRM on its position relative to the core, and on core activities. RRM/RNA complex formation substantially shifts the RRM from a position close to the RecA_C to the proximity of RecA_N, independent of RNA contacts with the core. RNA binding to the RRM is communicated to the core, and stimulates ATP hydrolysis and RNA unwinding. The conformational space of the core depends on the identity of the RRM-bound RNA. Allosteric regulation of core activities by RNA-induced movement of ancillary domains may constitute a general regulatory mechanism of DEAD-box protein activity.

  12. Measuring shape fluctuations in biological membranes

    Monzel, C.; Sengupta, K.

    2016-06-01

    Shape fluctuations of lipid membranes have intrigued cell biologists and physicists alike. In the cellular context, their origin—thermal or active—and their physiological significance are open questions. These small incessant displacements, also called membrane undulations, have mostly been studied in model membranes and membranes of simple cells like erythrocytes. Thermal fluctuations of such membranes have been very well described both theoretically and experimentally; active fluctuations are a topic of current interest. Experimentally, membrane fluctuations are not easy to measure, the main challenge being to develop techniques which are capable of measuring very small displacements at very high speed, and preferably over a large area and long time. Scattering techniques have given access to fluctuations in membrane stacks and a variety of optical microscopy based techniques have been devised to study membrane fluctuations of unilamellar vesicles, erythrocytes and other cells. Among them are flicker spectroscopy, dynamic light scattering, diffraction phase microscopy and reflection interference contrast microscopy. Each of these techniques has its advantages and limitations. Here we review the basic principles of the major experimental techniques used to measure bending or shape fluctuations of biomembranes. We report seminal results obtained with each technique and highlight how these studies furthered our understanding of physical properties of membranes and their interactions. We also discuss suggested role of membrane fluctuations in different biological processes.

  13. Fluctuations of fragment observables

    Gulminelli, F

    2006-01-01

    This contribution presents a review of our present theoretical as well as experimental knowledge of different fluctuation observables relevant to nuclear multifragmentation. The possible connection between the presence of a fluctuation peak and the occurrence of a phase transition or a critical phenomenon is critically analyzed. Many different phenomena can lead both to the creation and to the suppression of a fluctuation peak. In particular, the role of constraints due to conservation laws and to data sorting is shown to be essential. From the experimental point of view, a comparison of the available fragmentation data reveals that there is a good agreement between different data sets of basic fluctuation observables, if the fragmenting source is of comparable size. This compatibility suggests that the fragmentation process is largely independent of the reaction mechanism (central versus peripheral collisions, symmetric versus asymmetric systems, light ions versus heavy ion induced reactions). Configurationa...

  14. Altered spontaneous brain activity pattern in patients with high myopia using amplitude of low-frequency fluctuation: a resting-state fMRI study

    Huang X

    2016-11-01

    Full Text Available Xin Huang,1,2,* Fu-Qing Zhou,3,* Yu-Xiang Hu,1 Xiao-Xuan Xu,1 Xiong Zhou,4 Yu-Lin Zhong,1 Jun Wang,4 Xiao-Rong Wu1 1Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang, 2Department of Ophthalmology, The First People’s Hospital of Jiujiang City, Jiujiang, 3Department of Radiology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Medical Imaging Research Institute, 4Second Department of Respiratory Disease, Jiangxi Provincial People’s Hospital, Nanchang, Jiangxi, People’s Republic of China *These authors contributed equally to this work Objective: Many previous reports have demonstrated significant neural anatomy changes in the brain of high myopic (HM patients, whereas the spontaneous brain activity changes in the HM patients at rest are not well studied. Our objective was to use amplitude of low-frequency fluctuation (ALFF method to investigate the changes in spontaneous brain activity in HM patients and their relationships with clinical features. Methods: A total of 38 patients with HM (17 males and 21 females and 38 healthy controls (HCs (17 males and 21 females closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was used to assess local features of spontaneous brain activity. The relationship between the mean ALFF signal values in many brain regions and the clinical features in HM patients was calculated by correlation analysis. Results: Compared with HCs, the HM patients had significantly lower ALFF in the right inferior and middle temporal gyrus, left middle temporal gyrus, left inferior frontal gyrus/putamen, right inferior frontal gyrus/putamen/insula, right middle frontal gyrus, and right inferior parietal lobule and higher ALFF values in the bilateral midcingulate cortex, left postcentral gyrus, and left precuneus/inferior parietal lobule. However, no relationship was found between the mean ALFF

  15. The Combined Strength of Thermodynamics and Comparative Planetology: Application of Activity Models to Core Formation in Terrestrial Bodies

    Righter, K.; Pando, K. M.; Danielson, L. R.

    2015-01-01

    how large the effect of Si can be, these epsilon values correspond to activity coefficients (gamma) for As of 0.01 when XSi = 0, and up to gamma = 23 when XSi = 0.2. Combining these new results with previous determinations [5,6] of epsilon parameters for S and C for these elements allows us calculate activity of Ge, In, As, and Sb in Fe-Ni-Si-S-C-O metallic liquids. We apply this new model to sever-al terrestrial bodies such as Earth (Si-rich core), Mars (S-rich core), Moon (S-, C-, and Si-poor core), and Vesta, and examine the resulting core and mantle concentrations of these elements. Mantle concentrations of these four elements are well explained for Earth and Mars in models that call for mid-mantle equilibration between Si-bearing and S-bearing FeNi cores, respectively. Modeling results for the Moon and Vesta will also be presented.

  16. Microbial activity and phylogeny in ice cores retrieved from Lake Paula, a newly detected freshwater lake in Antarctica

    Sattler, Birgit I.; Waldhuber, Sebastian; Fischer, Helgard; Semmler, Hans; Sipiera, Paul P.; Psenner, Roland

    2004-11-01

    A permanent ice covered water body, called Lake Paula, was detected in Patriot Hills in the West Antarctic and sampled for the first time ever for microbial life. The ice sheet measured approximately 2,5m thickness and the water body has a depth of about 10m. The lake is situated near a moraine which partly ablates from snow and provides meltwater from the slopes to the lake during austral summer. These running waters which are kept liquid by the heating up of the dark soil are penetrating the lower ice cover and thus softening up the lakeside part if the ice core. It is inoculated by nutrients, active microbes and diatoms of terrestrial origin. A distinct gradient concerning bacterial numbers, biomass and production which is 10 fold at the ice-water interface compared to the exposed part is observable. Temperature sensitivity of the embedded microbes reflect the gradient as well: Bacteria isolated from the upper part showed growth optima at 10°C, the lower part at 25°C, phylogenetic properties done by 16s rDNA reveal distinct communities depending on their vertical position, some clones are similar to those retrieved in Lake Vostok ice cores. These results offer the conclusion that even in this harsh environment like the Antarctic continent a dynamic system like microbial ice aggregates can be sustained as long as the supply of liquid water which is essential for an active bacterial metabolism is provided at least for a small time frame.

  17. Film Growth Rates and Activation Energies for Core-Shell Nanoparticles Derived from a CVD Based Aerosol Process

    Frederik Weis

    2015-03-01

    Full Text Available Silica core-shell nanoparticles of about 60–120 nm with a closed outer layer of bismuth or molybdenum oxide of 1–10 nm were synthesized by an integrated chemical vapor synthesis/chemical vapor deposition process at atmospheric pressure. Film growth rates and activation energies were derived from transmission electron microscopy (TEM images for a deposition process based on molybdenum hexacarbonyl and triphenyl bismuth as respective coating precursors. Respective activation energies of 123 ± 10 and 155 ± 10 kJ/mol are in good agreement with the literature and support a deposition mechanism based on surface-induced removal of the precursor ligands. Clean substrate surfaces are thus prerequisite for conformal coatings. Integrated aerosol processes are solvent-free and intrinsically clean. In contrast, commercial silica substrate particles were found to suffer from organic residues which hinder shell formation, and require an additional calcination step to clean the surface prior to coating. Dual layer core-shell structures with molybdenum oxide on bismuth oxide were synthesized with two coating reactors in series and showed similar film growth rates.

  18. Using Indices of Fidelity to Intervention Core Components to Identify Program Active Ingredients

    Abry, Tashia; Hulleman, Chris S.; Rimm-Kaufman, Sara E.

    2015-01-01

    Identifying the active ingredients of an intervention--intervention-specific components serving as key levers of change--is crucial for unpacking the intervention black box. Measures of intervention fidelity can be used to identify specific active ingredients, yet such applications are rare. We illustrate how fidelity measures can be used to…

  19. Hollow Ag@Pd core-shell nanotubes as highly active catalysts for the electro-oxidation of formic acid

    Jiang, Yuanyuan; Lu, Yizhong; Han, Dongxue

    2012-01-01

    by detailed characterizations. The Ag@Pd can significantly improve the electrocatalytic activity towards the electro-oxidation of formic acid and enhance the stability of the Pd component. It is proposed that the enhanced electrochemically active surface area and modulated electron structure of Pd by Ag......Ag nanowires are prepared as templates by a polyol reduction process. Then Ag nanotubes coated with a thin layer of Pd are synthesized through sequential reduction accompanied with the galvanic displacement reaction. The products show a hollow core-shell nanotubular structure, as demonstrated......-shell structure with a hollow interior, which can be applied as high-performance catalysts for the electro-oxidation of formic acid....

  20. Calculations of ADS with deep subcritical uranium active cores - comparison with experiments and predictions

    Zhivkov, P.; Furman, W.; Stoyanov, Ch

    2014-09-01

    The main characteristics of the neutron field formed within the massive (512 kg) natural uranium target assembly (TA) QUINTA irradiated by deuteron beam of JINR Nuclotron with energies 1,2,4, and 8 GeV as well as the spatial distributions and the integral numbers of (n,f), (n,γ) and (n,xn)- reactions were calculated and compared with experimental data [1] . The MCNPX 27e code with ISABEL/ABLA/FLUKA and INCL4/ABLA models of intra-nuclear cascade (INC) and experimental cross-sections of the corresponding reactions were used. Special attention was paid to the elucidation of the role of charged particles (protons and pions) in the fission of natural uranium of TA QUINTA. Extensive calculations have been done for quasi-infinite (with very small neutron leakage) depleted uranium TA BURAN having mass about 20 t which are intended to be used in experiments at Nuclotron in 2014-2016. As in the case of TA QUINTA which really models the central zone of TA BURAN the total numbers of fissions, produced 239Pu nuclei and total neutron multiplicities are predicted to be proportional to proton or deuteron energy up to 12 GeV. But obtained values of beam power gain are practically constant in studied incident energy range and are approximately four. These values are in contradiction with the experimental result [2] obtained for the depleted uranium core weighting three tons at incident proton energy 0.66 GeV.

  1. Lipid-Core Nanocapsules Improved Antiedematogenic Activity of Tacrolimus in Adjuvant-Induced Arthritis Model.

    Friedrich, Rossana B; Coradini, Karine; Fonseca, Francisco N; Guterres, Silvia S; Beck, Ruy C R; Pohlmann, Adriana R

    2016-02-01

    Despite significant technological advances, rheumatoid arthritis remains an incurable disease with great impact on the life quality of patients. We studied the encapsulation of tacrolimus in lipidcore nanocapsules (TAC-LNC) as a strategy to enhance its systemic anti-arthritic properties. TAC-LNC presented unimodal distribution of particles with z-average diameter of 212 +/- 11, drug content close to the theoretical value (0.80 mg mL(-1)), and 99.43% of encapsulation efficiency. An in vitro sustained release was determined for TAC-LNC with anomalous transport mechanism (n = 0.61). In vivo studies using an arthritis model induced by Complete Freund's Adjuvant demonstrated that the animals treated with TAC-LNC presented a significantly greater inhibition of paw oedema after intraperitoneal administration. Furthermore, the encapsulation of TAC in lipid-core nanocapsules was potentially able to prevent hyperglycemia in the animals. In conclusion, TAC-LNC was prepared with 100% yield of nanoscopic particles having satisfactory characteristics for systemic use. This formulation represents a promising strategy to the treatment of rheumatoid arthritis in the near future.

  2. Highly active and durable core-corona structured bifunctional catalyst for rechargeable metal-air battery application.

    Chen, Zhu; Yu, Aiping; Higgins, Drew; Li, Hui; Wang, Haijiang; Chen, Zhongwei

    2012-04-11

    A new class of core-corona structured bifunctional catalyst (CCBC) consisting of lanthanum nickelate centers supporting nitrogen-doped carbon nanotubes (NCNT) has been developed for rechargeable metal-air battery application. The nanostructured design of the catalyst allows the core and corona to catalyze the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), respectively. These materials displayed exemplary OER and ORR activity through half-cell testing, comparable to state of the art commercial lanthanum nickelate (LaNiO(3)) and carbon-supported platinum (Pt/C), with added bifunctional capabilities allowing metal-air battery rechargeability. LaNiO(3) and Pt/C are currently the most accepted benchmark electrocatalyst materials for the OER and ORR, respectively; thus with comparable activity toward both of these reactions, CCBC are presented as a novel, inexpensive catalyst component for the cathode of rechargeable metal-air batteries. Moreover, after full-range degradation testing (FDT) CCBC retained excellent activity, retaining 3 and 13 times greater ORR and OER current upon comparison to state of the art Pt/C. Zinc-air battery performances of CCBC is in good agreement with the half-cell experiments with this bifunctional electrocatalyst displaying high activity and stability during battery discharge, charge, and cycling processes. Owing to its outstanding performance toward both the OER and ORR, comparable with the highest performing commercial catalysts to date for each of the respective reaction, coupled with high stability and rechargeability, CCBC is presented as a novel class of bifunctional catalyst material that is very applicable to future generation rechargeable metal-air batteries.

  3. Traveling planetary wave ionospheric disturbances and their role in the generation of equatorial spread-F and GPS phase fluctuations during the last extreme low solar activity and comparison with high solar activity

    de Abreu, A. J.; Fagundes, P. R.; Bolzan, M. J. A.; Gende, M.; Brunini, C.; de Jesus, R.; Pillat, V. G.; Abalde, J. R.; Lima, W. L. C.

    2014-09-01

    This investigation studies traveling planetary wave ionospheric disturbance (TPWID) type oscillations on the modulation of the F region virtual height rise during the E×B electric field pre-reversal enhancement (PRE), near sunset hours. We also studied their role in the generation of equatorial spread F (ESF) and GPS phase fluctuations during periods of the last extreme low solar activity (LSA) of January 2009 to April 2010 (F10.7bar=73). A comparison is made with periods of high solar activity (HSA) in 2003 and 2004 near equatorial region. The ionospheric irregularities investigated are medium (bottom-side) and large (plasma bubble) scales. Ionospheric F region oscillations with period of days are due to the TPWIDs, which play an important role in producing favorable or unfavorable conditions for equatorial ionospheric irregularities, changing the electron vertical profile and F region height. In this paper, we present simultaneous ionospheric sounding (ionosonde) and GPS vertical total electron content (vTEC) observations carried out near equatorial region (Palmas 10.2°S, 48.2°W) and low latitude region (São José dos Campos 23.2°S, 45.9°W; located under the southern crest of the equatorial ionospheric anomaly), Brazil. Observations show that the occurrence of fresh ESF during LSA and HSA and fresh GPS phase fluctuations at equatorial region follow the trend of day-to-day variations in the F region virtual height, which are due to electric field PRE modulated by TPWID wave like oscillations. During LSA, the altitude of 250 km acts as a threshold height for the generation of fresh ionospheric irregularities, whereas during HSA, the threshold height is 300 km. The observations also found a strong increase in the generation of fresh ionospheric irregularities from October 2009 to March 2010 during LSA and from September 2003 to March 2004 during the HSA. Furthermore, in LSA, the period of fresh ionospheric irregularities was less than during HSA, though both

  4. Growth rate controlled synthesis of hierarchical Bi2S3/In2S3 core/shell microspheres with enhanced photocatalytic activity

    Zhou, Juan; Tian, Guohui; Chen, Yajie; Shi, Yunhan; Tian, Chungui; Pan, Kai; Fu, Honggang

    2014-02-01

    Core/shell heterostructure composite has great potential applications in photocatalytic field because the introduction of core can remarkably improve charge transport and enhance the electron-hole separation. Herein, hierarchical Bi2S3/In2S3 core/shell structured microspheres were prepared via a simple one-pot hydrothermal process based on different growth rate of the two kinds of sulphides. The results showed that, the as-prepared hierarchical Bi2S3/In2S3 core/shell heterostructure exhibits significant visible light photocatalytic activity for degradation of 2, 4-dichlorophenol. The introduction of Bi2S3 core can not only improve charge transport and enhance the electron-hole separation, but also broaden the visible light response. The hierarchical porous folwer-like shell of In2S3 could increase the specific surface area and remarkably enhanced the chemical stability of Bi2S3 against oxidation.

  5. Proteomics Core

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in a...

  6. Proteomics Core

    Federal Laboratory Consortium — Proteomics Core is the central resource for mass spectrometry based proteomics within the NHLBI. The Core staff help collaborators design proteomics experiments in...

  7. Hydrothermal quartz formation during fluctuations of brittle shear-zone activity and fluid flow: grain growth and deformation structures of the Pfahl shear zone (Germany)

    Yilmaz, T.; Prosser, G.; Liotta, D.; Kruhl, J. H.

    2012-12-01

    , crosscutting the first generations of fine-grained quartz mass and the wall rocks, in connection to intense fracturing and brecciation. The complex geometry of the vein sets points to multiple fluid injections and brecciation, as additionally indicated by coarse quartz with different inclusion and CL intensity. Temporal changes of strain rate are indicated by crystal plastic deformation structures in quartz, which overprint brittle structures. (iv) The fourth quartz generation occurs in mm- to dm-thick quartz veins, partly open as geodes, filling N-S oriented cm- to dm-spaced fractures that crosscut the earlier quartz masses and veins and extend at least several meters into the wall rock. They indicate the last activity of the shear-zone in a constant kinematic framework. Summarizing, the Pfahl shear zone shows brittle-ductile deformation during the long-term activity of a large-scale hydrothermal system. Consequently, it represents an excellent example where different generations of quartz precipitation can be connected to fluctuations of fluid flow and strain rate.

  8. Spin fluctuations and the

    V.M. Loktev

    2008-09-01

    Full Text Available We analyze the spectral properties of a phenomenological model for a weakly doped two-dimensional antiferromagnet, in which the carriers move within one of the two sublattices where they were introduced. Such a constraint results in the free carrier spectra with the maxima at k=(± π/2 , ± π/2 observed in some cuprates. We consider the spectral properties of the model by taking into account fluctuations of the spins in the antiferromagnetic background. We show that such fluctuations lead to a non-pole-like structure of the single-hole Green's function and these fluctuations can be responsible for some anomalous "strange metal" properties of underdoped cuprates in the nonsuperconducting regime.

  9. Scaling and calibration of a core validation site for the soil moisture active passive mission

    The calibration and validation of soil moisture remote sensing products is complicated due to the logistics of installing a long term soil moisture monitoring network in an active landscape. It is more efficient to locate these stations along agricultural field boundaries, but unfortunately this oft...

  10. The fluctuating gap model

    Cao, Xiaobin

    2011-01-15

    The quasi-one-dimensional systems exhibit some unusual phenomenon, such as the Peierls instability, the pseudogap phenomena and the absence of a Fermi-Dirac distribution function line shape in the photoemission spectroscopy. Ever since the discovery of materials with highly anisotropic properties, it has been recognized that fluctuations play an important role above the three-dimensional phase transition. This regime where the precursor fluctuations are presented can be described by the so called fluctuating gap model (FGM) which was derived from the Froehlich Hamiltonian to study the low energy physics of the one-dimensional electron-phonon system. Not only is the FGM of great interest in the context of quasi-one-dimensional materials, liquid metal and spin waves above T{sub c} in ferromagnets, but also in the semiclassical approximation of superconductivity, it is possible to replace the original three-dimensional problem by a directional average over effectively one-dimensional problem which in the weak coupling limit is described by the FGM. In this work, we investigate the FGM in a wide temperature range with different statistics of the order parameter fluctuations. We derive a formally exact solution to this problem and calculate the density of states, the spectral function and the optical conductivity. In our calculation, we show that a Dyson singularity appears in the low energy density of states for Gaussian fluctuations in the commensurate case. In the incommensurate case, there is no such kind of singularity, and the zero frequency density of states varies differently as a function of the correlation lengths for different statistics of the order parameter fluctuations. Using the density of states we calculated with non-Gaussian order parameter fluctuations, we are able to calculate the static spin susceptibility which agrees with the experimental data very well. In the calculation of the spectral functions, we show that as the correlation increases, the

  11. Health physics activities in support of the thermal shield removal/disposal and core support barrel repair at the St. Lucie Nuclear Power Plant.

    Maisler, J J; Buchanan, H F

    1988-02-01

    The health physics activities related to the removal and disposal of a thermal shield at a nuclear power plant and subsequent repairs to the core support barrel required increased planning relative to a normal refueling/maintenance outage. The repair of the core support barrel was a "first" in the nuclear power industry. Pre-job planning was of great concern because of extremely high radiation levels associated with the irradiated stainless steel thermal shield and core support barrel. ALARA techniques used in the preparation of the thermal shield for removal and shipment to the disposal site are discussed.

  12. Hemocompatibility of Polyvinyl Alcohol-Gelatin Core-Shell Electrospun Nanofibers: A Novel Scaffold for Modulating Platelet Deposition and Activation

    Merkle, Valerie M.; Martin, Daniel; Hutchinson, Marcus; Tran, Phat L.; Behrens, Alana; Hossainy, Samir; Bluestein, Danny; Wu, Xiaoyi; Slepian, Marvin J.

    2015-01-01

    In this study, we evaluate coaxial electrospun nanofibers with gelatin in the shell and polyvinyl (PVA) in the core as a potential vascular material by determining fiber surface roughness, as well as human platelet deposition and activation under varying conditions. PVA scaffolds had the highest surface roughness (Ra = 65.5 ± 6.8 nm) but the lowest platelet deposition (34.2 ± 5.8 platelets) in comparison to gelatin nanofibers (Ra = 36.8 ± 3.0 nm & 168.9 ± 29.8 platelets) and coaxial nanofibers (1 Gel: 1 PVA coaxial – Ra = 24.0 ± 1.5 nm & 150.2 ± 17.4 platelets; 3 Gel: 1 PVA coaxial – Ra = 37.1 ± 2.8 nm & 167.8 ± 15.4 platelets). Therefore, the chemical structure of the gelatin nanofibers dominated surface roughness in platelet deposition. Due to their increased stiffness, the coaxial nanofibers had the highest platelet activation rate – rate of thrombin formation, in comparison to gelatin and PVA fibers. Our studies indicate that mechanical stiffness is a dominating factor for platelet deposition and activation, followed by biochemical moieties, and lastly surface roughness. Overall, these coaxial nanofibers are an appealing material for vascular applications by supporting cellular growth while minimizing platelet deposition and activation. PMID:25815434

  13. Event-by-Event Fluctuations

    2003-01-01

    In this review, we systematically examine the principles and the practices of fluctuations such as the momentum and the charge fluctuations as applied to the heavy ion collisions. Main emphases are: (i) Fluctuations as signals of phase transition (ii) Relationship between correlation functions and fluctuations (iii) Qualitative difference between fluctuations in small systems and large systems. Whenever available, theoretical results are compared with data from RHIC and SPS.

  14. Effects of phase transition induced density fluctuations on pulsar dynamics

    Partha Bagchi

    2015-07-01

    Full Text Available We show that density fluctuations during phase transitions in pulsar cores may have non-trivial effects on pulsar timings, and may also possibly account for glitches and anti-glitches. These density fluctuations invariably lead to non-zero off-diagonal components of the moment of inertia, leading to transient wobbling of star. Thus, accurate measurements of pulsar timing and intensity modulations (from wobbling may be used to identify the specific pattern of density fluctuations, hence the particular phase transition, occurring inside the pulsar core. Changes in quadrupole moment from rapidly evolving density fluctuations during the transition, with very short time scales, may provide a new source for gravitational waves.

  15. Scaling Properties of Fluctuations in Human Electroencephalogram

    Hwa, R C; Hwa, Rudolph C.; Ferree, Thomas C.

    2002-01-01

    The fluctuation properties of the human electroencephalogram (EEG) time series are studied using detrended fluctuation analysis. For all 128 channels in each of 18 subjects studied, it is found that the standard deviation of the fluctuations exhibits scaling behaviors in two regions. Topographical plots of the scaling exponents reveal the spatial structure of the nonlinear electrical activities recorded on the scalp. Moment analyses are performed to extract the gross features of all the scaling exponents. The correlation between the two scaling exponents in each channel is also examined. It is found that two indices can characterize the overall properties of the fluctuation behaviors of the brain dynamics for every subject and that they vary widely across the subjects.

  16. Magnetic heating properties and neutron activation of tungsten-oxide coated biocompatible FePt core-shell nanoparticles.

    Seemann, K M; Luysberg, M; Révay, Z; Kudejova, P; Sanz, B; Cassinelli, N; Loidl, A; Ilicic, K; Multhoff, G; Schmid, T E

    2015-01-10

    Magnetic nanoparticles are highly desirable for biomedical research and treatment of cancer especially when combined with hyperthermia. The efficacy of nanoparticle-based therapies could be improved by generating radioactive nanoparticles with a convenient decay time and which simultaneously have the capability to be used for locally confined heating. The core-shell morphology of such novel nanoparticles presented in this work involves a polysilico-tungstate molecule of the polyoxometalate family as a precursor coating material, which transforms into an amorphous tungsten oxide coating upon annealing of the FePt core-shell nanoparticles. The content of tungsten atoms in the nanoparticle shell is neutron activated using cold neutrons at the Heinz Maier-Leibnitz (FRMII) neutron facility and thereby transformed into the radioisotope W-187. The sizeable natural abundance of 28% for the W-186 precursor isotope, a radiopharmaceutically advantageous gamma-beta ratio of γβ≈30% and a range of approximately 1mm in biological tissue for the 1.3MeV β-radiation are promising features of the nanoparticles' potential for cancer therapy. Moreover, a high temperature annealing treatment enhances the magnetic moment of nanoparticles in such a way that a magnetic heating effect of several degrees Celsius in liquid suspension - a prerequisite for hyperthermia treatment of cancer - was observed. A rise in temperature of approximately 3°C in aqueous suspension is shown for a moderate nanoparticle concentration of 0.5mg/ml after 15min in an 831kHz high-frequency alternating magnetic field of 250Gauss field strength (25mT). The biocompatibility based on a low cytotoxicity in the non-neutron-activated state in combination with the hydrophilic nature of the tungsten oxide shell makes the coated magnetic FePt nanoparticles ideal candidates for advanced radiopharmaceutical applications.

  17. Up-regulation effect of hepatitis B virus genome A1846T mutation on viral replication and core promoter activity

    Ling JIANG

    2013-01-01

    Full Text Available Objective  To evaluate the influence of hepatitis B virus (HBV genome nucleotide A1846T mutation on the viral replication capacity and the transcription activity of HBV core promoter (CP in vitro. Methods  A total of 385 patients with hepatitis B admitted to the 302 Hospital of PLA were enrolled in the study, including 116 with moderate chronic hepatitis B (CHB-M, 123 with severe chronic hepatitis B (CHB-S, and 146 with acute-on-chronic liver failure (ACLF. Serum HBV DNA was isolated and full-length HBV genome was amplified. The incidence of A1846T was analyzed. Full-length HBV genomes containing 1846T mutation were cloned into pGEM-T easy vector, and the counterpart wild-type 1846A plasmids were obtained by site-directed mutagenesis. The full-length HBV genome was released from recombinant plasmid by BspQ Ⅰ/Sca Ⅰ digestion, and then transfected into HepG2 cells. Secreted HBsAg level and intracellular HBV core particles were measured 72 hours post-transfection to analyze the replication capacity (a 1.0-fold HBV genome model. 1846 mutant and wild-type full-length HBV genomes were extracted to amplify the fragment of HBV CP region, and the dual luciferase reporter of the pGL3-CP was constructed. The luciferase activity was detected 48 hours post-transfection. Results  The incidence of A1846T mutation gradually increased with the severity of hepatitis B, reaching 31.03%, 42.27%, and 55.48% in CHB-M, CHB-S and ACLF patients respectively (P<0.01. The replication capacity of 1846T mutants, level of secreted HBsAg, and transcriptional activity of CP promoter were increased by 320%, 28% and 85% respectively, compared with 1846A wild-type strains. While the more common double mutation A1762T/G1764A in CP region was increased by 67%, 9% and 72% respectively, compared with its counterpart wild-type strains. A1846T had a greater influence on viral replication capacity in vitro. Conclusions A1846T mutation could significantly increase the

  18. Core shell methyl methacrylate chitosan nanoparticles: In vitro mucoadhesion and complement activation

    F Atyabi

    2011-10-01

    Full Text Available Background and the purpose of the study: Studies show that chitosan nanoparticles increase mucoadhesivity and penetration of large molecules across mucosal surface. The aim of the present study was to investigate the use of thiolated chitosan in the development of polysaccharide-coated nanoparticles in order to confer specific functionality to the system. Methods: Methyl methacrylate nanoparticles were coated with thiolated chitosan using a radical polymerization method. Thiolation was carried out using glutathione (GSH to improve mucoadhesivity and permeation enhancing properties of chitosan. Mucoadhesion studies were carried out by calculating the amount of mucin adsorbed on nanoparticles in a specific period of time. Complement consumption was assessed in human serum (HS by measurement of the hemolytic capacity of the complement system after contact with nanoparticles.   Results:   The FT-IR and 1HNMR spectra both confirmed the synthesis and showed the conjugation of thiolated chitosan to methyl methacrylate (MMA homopolymer. Nanoparticles were spherical having a mean diameter within the range of about 334-650 nm and their positive zeta potential values indicated the presence of the cationic polysaccharide at the nanoparticle surface. Increasing the amount of thiolated chitosan led to mucoadhesivity and complement activation. However there was not dose dependent correlation between these phenomenons and the absence of thiolated chitosan led to particles with larger size, and without ability to activate complement process. Major conclusion: It can be concluded that nanoparticles could be used for the mucosal delivery of peptides and proteins. Results show that the thiolated chitosan had higher mucoadhesion and complement activation than unmodified chitosan.

  19. Diagnostics for fluctuation measurements

    Donne, A. J. H.

    2000-01-01

    Transport of particles and heat in magnetic confinement devices is largely attributed to the presence of microscopic instabilities. To better understand the physical mechanisms underlying plasma transport processes it is necessary to diagnose the fluctuations in the various quantities along with the

  20. Fluctuating Asymmetry and Intelligence

    Bates, Timothy C.

    2007-01-01

    The general factor of mental ability ("g") may reflect general biological fitness. If so, "g"-loaded measures such as Raven's progressive matrices should be related to morphological measures of fitness such as fluctuating asymmetry (FA: left-right asymmetry of a set of typically left-right symmetrical body traits such as finger…

  1. Nonequilibrium mesoscopic conductance fluctuations

    Ludwig, T.; Blanter, Ya. M.; Mirlin, A. D.

    2004-12-01

    We investigate the amplitude of mesoscopic fluctuations of the differential conductance of a metallic wire at arbitrary bias voltage V . For noninteracting electrons, the variance ⟨δg2⟩ increases with V . The asymptotic large- V behavior is ⟨δg2⟩˜V/Vc (where eVc=D/L2 is the Thouless energy), in agreement with the earlier prediction by Larkin and Khmelnitskii. We find, however, that this asymptotics has a very small numerical prefactor and sets in at very large V/Vc only, which strongly complicates its experimental observation. This high-voltage behavior is preceded by a crossover regime, V/Vc≲30 , where the conductance variance increases by a factor ˜3 as compared to its value in the regime of universal conductance fluctuations (i.e., at V→0 ). We further analyze the effect of dephasing due to the electron-electron scattering on ⟨δg2⟩ at high voltages. With the Coulomb interaction taken into account, the amplitude of conductance fluctuations becomes a nonmonotonic function of V . Specifically, ⟨δg2⟩ drops as 1/V for voltages V≫gVc , where g is the dimensionless conductance. In this regime, the conductance fluctuations are dominated by quantum-coherent regions of the wire adjacent to the reservoirs.

  2. A comparison of designer activity using core design situations in the laboratory and practice

    Cash, Philip; Hicks, Ben J.; Culley, Steve J.

    2013-01-01

    In 2011 one quarter of all articles published in Design Studies and the Journal of Engineering Design used experimental studies. However, there is little work exploring the relationship between laboratory and practice. This paper addresses this by detailing an analysis of designer activity in three...... situations commonly studied by design researchers: information seeking, ideation and design review. This comparison is instantiated through three complementary studies: an observational study of practice and two experimental studies. These reveal a range of similarities and differences that are described...

  3. Fluctuational shift of nematic-isotropic phase transition temperature

    Kats, E. I.

    2017-02-01

    In this work we discuss a macroscopic counterpart to the microscopic mechanism of the straightening dimer mesogens conformations, proposed recently by S.M. Saliti, M.G.Tamba, S.N. Sprunt, C.Welch, G.H.Mehl, A. Jakli, J.T. Gleeson (Phys. Rev. Lett. 116, 217801 (2016)) to explain their experimental observation of the unprecedentedly large shift of the nematic-isotropic transition temperature. Our interpretation is based on singular longitudinal fluctuations of the nematic order parameter. Since these fluctuations are governed by the Goldstone director fluctuations they exist only in the nematic state. External magnetic field suppresses the singular longitudinal fluctuations of the order parameter (similarly as it is the case for the transverse director fluctuations, although with a different scaling over the magnetic field). The reduction of the fluctuations changes the equilibrium value of the modulus of the order parameter in the nematic state. Therefore it leads to additional (with respect to the mean field contribution) fluctuational shift of the nematic-isotropic transition temperature. Our mechanism works for any nematic liquid crystals, however the magnitude of the fluctuational shift increases with decrease of the Frank elastic moduli. Since some of these moduli supposed to be anomalously small for so-called bent-core or dimer nematic liquid crystals, just these liquid crystals are promising candidates for the observation of the predicted fluctuational shift of the phase transition temperature.

  4. A Conserved GPG-Motif in the HIV-1 Nef Core Is Required for Principal Nef-Activities.

    Marta Martínez-Bonet

    Full Text Available To find out new determinants required for Nef activity we performed a functional alanine scanning analysis along a discrete but highly conserved region at the core of HIV-1 Nef. We identified the GPG-motif, located at the 121-137 region of HIV-1 NL4.3 Nef, as a novel protein signature strictly required for the p56Lck dependent Nef-induced CD4-downregulation in T-cells. Since the Nef-GPG motif was dispensable for CD4-downregulation in HeLa-CD4 cells, Nef/AP-1 interaction and Nef-dependent effects on Tf-R trafficking, the observed effects on CD4 downregulation cannot be attributed to structure constraints or to alterations on general protein trafficking. Besides, we found that the GPG-motif was also required for Nef-dependent inhibition of ring actin re-organization upon TCR triggering and MHCI downregulation, suggesting that the GPG-motif could actively cooperate with the Nef PxxP motif for these HIV-1 Nef-related effects. Finally, we observed that the Nef-GPG motif was required for optimal infectivity of those viruses produced in T-cells. According to these findings, we propose the conserved GPG-motif in HIV-1 Nef as functional region required for HIV-1 infectivity and therefore with a potential interest for the interference of Nef activity during HIV-1 infection.

  5. "Hot" Non-flaring Plasmas in Active Region Cores Heated by Single Nanoflares

    Barnes, Will Thomas; Cargill, Peter; Bradshaw, Stephen

    2016-05-01

    We use hydrodynamic modeling tools, including a two-fluid development of the EBTEL code, to investigate the properties expected of "hot" (i.e. between 106.7 and 107.2 K) non-flaring plasmas due to nanoflare heating in active regions. Here we focus on single nanoflares and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between 1 MK and 10 MK. Signatures of the actual heating may be detectable in some instances.

  6. Size-selective QD@MOF core-shell nanocomposites for the highly sensitive monitoring of oxidase activities.

    Wang, Ke; Li, Nan; Zhang, Jing; Zhang, Zhiqi; Dang, Fuquan

    2017-01-15

    In this work, we proposed a novel and facile method to monitor oxidase activities based on size-selective fluorescent quantum dot (QD)@metal-organic framework (MOF) core-shell nanocomposites (CSNCPs). The CSNCPs were synthesized from ZIF-8 and CdTe QDs in aqueous solution in 40min at room temperature with stirring. The prepared CdTe@ZIF-8 CSNCPs , which have excellent water dispersibility and stability, displays distinct fluorescence responses to hole scavengers of different molecular sizes (e.g., H2O2, substrate, and oxidase) due to the aperture limitation of the ZIF-8 shell. H2O2 can efficiently quench the fluorescence of CdTe@ZIF-8 CSNCPs over a linearity range of 1-100nM with a detection limit of 0.29nM, whereas large molecules such as substrate and oxidase have very little effect on its fluorescence. Therefore, the highly sensitive detection of oxidase activities was achieved by monitoring the fluorescence quenching of CdTe@ZIF-8 CSNCPs by H2O2 produced in the presence of substrate and oxidase, which is proportional to the oxidase activities. The linearity ranges of the uricase and glucose oxidase activity are 0.1-50U/L and 1-100U/L, respectively, and their detection limits are 0.024U/L and 0.26U/L, respectively. Therefore, the current QD@MOF CSNCPs based sensing system is a promising, widely applicable means of monitoring oxidase activities in biochemical research.

  7. Monster Sawtooth Activity in Ohmically Heated HT-7 Plasma

    胡立群; 石跃江; 刘胜侠

    2001-01-01

    Experimental properties of monster sawtooth activities in ohmic HT-7 plasma are presented in this paper. The monster sawtooth activities belong to global fluctuations and are characterized with a series of large core collapses on SXR intensity traces with a long period, a large amplitude fluctuation and a large inversion radius. However, they emerge without apparent deterioration of plasma confinement and without major plasma disruption. During the events,long partial sawtooth collapses and abundant MHD phenomena are also observed.

  8. Evaporation Of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Effluent Management Facility Core Simulant

    Adamson, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Mcclane, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-09-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation, and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator, in the Effluent Management Facility (EMF), and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter, and new evaporator so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would reduce the need for closely integrated operation of the LAW melter and the Pretreatment Facilities. Long-term implementation of this option after WTP start-up would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other operational complexities such a recycle stream presents. In order to accurately plan for the disposition path, it is key to experimentally determine the fate of contaminants. To do this, testing is needed to accurately account for the buffering chemistry of the components, determine the achievable evaporation end point, identify insoluble solids that form, and determine the distribution of key regulatory-impacting constituents.

  9. THE IMPLICATIONS OF MARKETING ACTIVITY IN RISK ANALYSIS, CORE ELEMENT OF LENDING POLICY TO COMMERCIAL BANKS

    Magda Florin-Mihai

    2013-04-01

    Full Text Available In the present financial context first affected by the lack of trust generated by the important bankruptcies in the USA and secondly by the global economic crisis, financial institutions are more than ever focused on applying market research, customer segmentation procedures and based upon them adapted credit strategies. The process is based on the fundaments of the marketing mix, much more carefully than before in order to maximize efficiency and market position or to consolidate, increase market share by taking advantage of opportunities or diminishing the effects of the present unfavorable economic climate. Analysis procedures based on differential risk models can be identified, the starting point being precisely the involvement of marketing by the market segmentation process and the concepts of “customer centricity” and “client relationship management”, specific credit policies being based upon them. The present paper intends to bring forth the client segmentation criteria practiced by top Romanian commercial banks, as the right segmentation process will reflect on the typology of financing over time. Furthermore, client segmentation tends to influence banking management in order to administer the risks arising from the credit activities, as it is in strict connection to the elements and processes involved in determining a correct rating of the applicants for funding.

  10. Magnetic properties changes due to hydrocarbon contaminated groundwater table fluctuations

    Ameen, Nawrass

    2013-04-01

    This study aims to understand the mechanisms and conditions which control the formation and transformation of ferro(i)magnetic minerals caused by hydrocarbon contaminated groundwater, in particular in the zone of fluctuating water levels. The work extends previous studies conducted at the same site. The study area is a former military air base at Hradčany, Czech Republic (50°37'22.71"N, 14°45'2.24"E). The site was heavily contaminated with petroleum hydrocarbons, due to leaks in petroleum storage tanks and jet fuelling stations over years of active use by the Soviet Union, which closed the base in 1991. The site is one of the most important sources of high quality groundwater in the Czech Republic. In a previous study, Rijal et al. (2010) concluded that the contaminants could be flushed into the sediments as the water level rose due to remediation processes leading to new formation of magnetite. In this previous study three different locations were investigated; however, from each location only one core was obtained. In order to recognize significant magnetic signatures versus depth three cores from each of these three locations were drilled in early 2012, penetrating the unsaturated zone, the groundwater fluctuation (GWF) zone and extending to about one meter below the groundwater level (~2.3 m depth at the time of sampling). Magnetic susceptibility (MS) profiles combined with other magnetic properties were analyzed to obtain a significant depth distribution of the ferro(i)magnetic concentration. Sediment properties, hydrocarbon content and bacterial activity were additionally studied. The results show that the highest ferrimagnetic mineral concentrations exist between 1.4-1.9 m depth from the baseline which is interpreted as the top of the GWF zone. Spikes of MS detected in the previous studies turned out to represent small-scale isolated features, but the trend of increasing MS values from the lowermost position of the groundwater table upward was verified

  11. The LVD Core Facility: a study of LVD as muon veto and active shielding for dark matter experiments

    Selvi, Marco

    2008-01-01

    In this study we explore the possibility of using the existing structure of a running experiment, the LVD supernova observatory at the INFN Gran Sasso National Laboratory, as an active shield and veto for the muon-induced background. In our vision LVD could become (without affecting in any way its main purpose of SN neutrino telescope) a host for a relatively compact but massive experiment looking for rare events. The empty volume that can be obtained removing 2 modules from the most internal part of the detector is 2.1m x 6.2m x 2.8m; we will call it LVD Core Facility (LVD-CF). We have evaluated the active vetoing and shielding power of LVD, with a detailed MC simulation (based on Geant4) of the detector and the rock that surrounds it. The results show that the flux of neutrons that are not associated with a visible muon in LVD is very low; it results reduced by a factor 50, equivalent to the one present in a much deeper underground laboratory, i.e. Sudbury. Moreover we present the results of on-going measur...

  12. Fluctuations in quantum devices

    H.Haken

    2004-01-01

    Full Text Available Logical gates can be formalized by Boolean algebra whose elementary operations can be realized by devices that employ the interactions of macroscopic numbers of elementary excitations such as electrons, holes, photons etc. With increasing miniaturization to the nano scale and below, quantum fluctuations become important and can no longer be ignored. Based on Heisenberg equations of motion for the creation and annihilation operators of elementary excitations, I determine the noise sources of composite quantum systems.

  13. Fluctuating Potential Barrier System with Correlated Spatial Noises

    LI Jing-Hui

    2004-01-01

    In this paper, we study a fluctuating potential barrier system with correlated spatial noises. Study shows that for this system, there is the resonant activation over the fluctuating potential barrier, and that the correlation between the different spatial noises can enhance (or weaken) the resonant activation.

  14. Core area and centre of activity of maned wolves, Chrysocyon brachyurus (Illiger (Mammalia, Canidae, submitted to supplemental feeding

    Joaquim de Araújo Silva

    2004-06-01

    Full Text Available Based on the finding of remains (tracks, scats, and hairs, an analysis was made of the core area and centre of activity of maned wolves, Chrysocyon brachyurus (Illiger, 1815, living in a private natural reserve in which ecotourism activities are developed and these animals are daily fed bovine meat. A total of 465 samples of remains were recorded. Using the fixed kernel method, the area encompassing all samples recorded was estimated at 25.7 km², yet 50% of all samples were found in an area of only 1.5 km², representing 5.8% of the total area covered. For estimating the core area of the animals, the frequency of occurrence of the samples was determined by superimposing a 50 x 50 m cell grid over a map of the area encompassing all recorded occurrences. Based on the cells containing more than six occurrences, the animals' core area was 0.99 km², which included the place where the animals are fed. The centre of activity was located only 0.50 km from this place. The high negative correlation (r = -0.93, p A área central e o centro de atividade de lobos-guará, Chrysocyon brachyurus (Illiger, 1815, foram determinados através de seus vestígios (fezes, pegadas e pêlos em uma reserva natural particular, onde esses animais estão sujeitos à alimentação artificial e sofrem influência de atividades turísticas. No total, foram registrados 465 vestígios, sendo que 65,8% corresponderam à estação seca. Através do método Kernel fixo, a área compreendida por todos os vestígios foi de 25,7 km², sendo que 50% encontravam-se em uma área de apenas 1,5 km², o que representou 5,8% do total da área amostrada. A área central de atividade dos animais foi obtida pelo cálculo da freqüência dos registros dos vestígios através da sobreposição de uma quadrícula subdividida em células de 50 x 50 m sobre a área que abrangia todos os registros. Considerando as células com mais de seis registros a área central de atividade atribuída aos

  15. The effect of core and lanthanide ion dopants in sodium fluoride-based nanocrystals on phagocytic activity of human blood leukocytes

    Sojka, Bartlomiej; Liskova, Aurelia; Kuricova, Miroslava; Banski, Mateusz; Misiewicz, Jan; Dusinska, Maria; Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela; Rollerova, Eva; Podhorodecki, Artur; Tulinska, Jana

    2017-02-01

    Sodium fluoride-based β-NaLnF4 nanoparticles (NPs) doped with lanthanide ions are promising materials for application as luminescent markers in bio-imaging. In this work, the effect of NPs doped with yttrium (Y), gadolinium (Gd), europium (Eu), thulium (Tm), ytterbium (Yb) and terbium (Tb) ions on phagocytic activity of monocytes and granulocytes and the respiratory burst was examined. The surface functionalization of <10-nm NPs was performed according to our variation of patent pending ligand exchange method that resulted in meso-2,3-dimercaptosuccinic acid (DMSA) molecules on their surface. Y-core-based NCs were doped with Eu ions, which enabled them to be excited with UV light wavelengths. Cultures of human peripheral blood ( n = 8) were in vitro treated with five different concentrations of eight NPs for 24 h. In summary, neither type of nanoparticles is found toxic with respect to conducted test; however, some cause toxic effects (they have statistically significant deviations compared to reference) in some selected doses tested. Both core types of NPs (Y-core and Gd-core) impaired the phagocytic activity of monocytes the strongest, having minimal or none whatsoever influence on granulocytes and respiratory burst of phagocytic cells. The lowest toxicity was observed in Gd-core, Yb, Tm dopants and near-infrared nanoparticles. Clear dose-dependent effect of NPs on phagocytic activity of leukocytes and respiratory burst of cells was observed for limited number of samples.

  16. Core biological marker candidates of Alzheimer's disease - perspectives for diagnosis, prediction of outcome and reflection of biological activity.

    Hampel, H; Mitchell, A; Blennow, K; Frank, R A; Brettschneider, S; Weller, L; Möller, H-J

    2004-03-01

    Alzheimer's disease (AD) is a complex neurodegenerative dementing illness. Over the past few years, however, remarkable advances have taken place in understanding both the genetic and molecular biology with the intracellular processing of amyloid and tau and the changes leading to the pathologic formation of extracellular amyloid plaques and the intraneuronal aggregation of hyperphosphorylated tau into neurofibrillary tangles. This progress in our understanding of the molecular pathology has set the stage for clinically meaningful advances in the development of biomarkers. Emerging diagnostic methods that are based on biochemical and imaging biomarkers of disease specific pathology hold the potential to provide effective measures of natural history (marker of disease that is predictive of outcome), biological activity (such as magnitude and frequency of response correlating with drug potency) and markers of surrogate endpoints (single or composite marker that accounts for clinical benefit of the therapy). Markers of biological activity should be also evaluated regarding their value to reflect disease progression, heterogeneity of the clinical population, for early decision making and characterization of new treatments. We focussed on the current status of core analytes which provide reasonable evidence for association with key mechanisms of pathogenesis or neurodegeneration in AD. In addition, feasibility was important, such as availability of a validated assay for the biological measure in question, with properties that included high precision and reliability of measurement, reagents and standards well described. On this basis we reviewed the body of literature that has examined CSF total tau (t-tau) and beta-amyloid 1-42 (Abeta(1-42)), phosphorylated tau (p-tau) and beta-amyloid-antibodies as diagnostic tests for AD versus clinically representative comparison groups. Measurement of t-tau and Abeta(1-42) in the CSF seems useful to discriminate early and incipient

  17. Enhancement of Alkaline Protease Activity and Stability via Covalent Immobilization onto Hollow Core-Mesoporous Shell Silica Nanospheres.

    Ibrahim, Abdelnasser Salah Shebl; Al-Salamah, Ali A; El-Toni, Ahmed M; Almaary, Khalid S; El-Tayeb, Mohamed A; Elbadawi, Yahya B; Antranikian, Garabed

    2016-01-29

    The stability and reusability of soluble enzymes are of major concerns, which limit their industrial applications. Herein, alkaline protease from Bacillus sp. NPST-AK15 was immobilized onto hollow core-mesoporous shell silica (HCMSS) nanospheres. Subsequently, the properties of immobilized proteases were evaluated. Non-, ethane- and amino-functionalized HCMSS nanospheres were synthesized and characterized. NPST-AK15 was immobilized onto the synthesized nano-supports by physical and covalent immobilization approaches. However, protease immobilization by covalent attachment onto the activated HCMSS-NH₂ nanospheres showed highest immobilization yield (75.6%) and loading capacity (88.1 μg protein/mg carrier) and was applied in the further studies. In comparison to free enzyme, the covalently immobilized protease exhibited a slight shift in the optimal pH from 10.5 to 11.0, respectively. The optimum temperature for catalytic activity of both free and immobilized enzyme was seen at 60 °C. However, while the free enzyme was completely inactivated when treated at 60 °C for 1 h the immobilized enzyme still retained 63.6% of its initial activity. The immobilized protease showed higher V(max), k(cat) and k(cat)/K(m), than soluble enzyme by 1.6-, 1.6- and 2.4-fold, respectively. In addition, the immobilized protease affinity to the substrate increased by about 1.5-fold. Furthermore, the enzyme stability in various organic solvents was significantly enhanced upon immobilization. Interestingly, the immobilized enzyme exhibited much higher stability in several commercial detergents including OMO, Tide, Ariel, Bonux and Xra by up to 5.2-fold. Finally, the immobilized protease maintained significant catalytic efficiency for twelve consecutive reaction cycles. These results suggest the effectiveness of the developed nanobiocatalyst as a candidate for detergent formulation and peptide synthesis in non-aqueous media.

  18. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores.

    Baccolo, Giovanni; Clemenza, Massimiliano; Delmonte, Barbara; Maffezzoli, Niccolò; Nastasi, Massimiliano; Previtali, Ezio; Prata, Michele; Salvini, Andrea; Maggi, Valter

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10(-13)-10(-6) g, improving previous results of 1-3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%.

  19. A Model for Lightcone Fluctuations due to Stress Tensor Fluctuations

    Bessa, C H G; Ford, L H; Ribeiro, C C H

    2016-01-01

    We study a model for quantum lightcone fluctuations in which vacuum fluctuations of the electric field and of the squared electric field in a nonlinear dielectric material produce variations in the flight times of probe pulses. When this material has a non-zero third order polarizability, the flight time variations arise from squared electric field fluctuations, and are analogous to effects expected when the stress tensor of a quantized field drives passive spacetime geometry fluctuations. We also discuss the dependence of the squared electric field fluctuations upon the geometry of the material, which in turn determines a sampling function for averaging the squared electric field along the path of the pulse. This allows us to estimate the probability of especially large fluctuations, which is a measure of the probability distribution for quantum stress tensor fluctuations.

  20. States and the (Not So) New Standards--Where Are They Now? State Academic Standards: Activity around the Common Core

    Salazar, Tonette; Christie, Kathy

    2014-01-01

    States began adopting the Common Core State Standards (CCSS) in 2010 after they were launched by the Council of Chief State School Officers and the National Governors Association. Five years later, policymakers in numerous states continue to debate the Common Core and related elements, such as how to assess the standards. This brief provides a…

  1. Simulation of nanoscale density fluctuations

    Reiss, Howard; Bowles, Richard K.

    2000-11-01

    Problems associated with the simulation of density fluctuations of limited breadth in a small cell are exposed and studied. The fluctuations are viewed as "physical clusters" of the type that might appear in nucleation processes and related phenomena. One of the most important features of the study stems from the fact that the simulation of a small heterogeneity in a macroscopic system presents problems that do not occur in the simulation of a bulk homogeneous property of the system. For example, once having simulated the probability of appearance of the fluctuation in a small cell, how is that result to be "mapped" onto the macrosystem in order to specify the equilibrium number of such fluctuations in that system? This problem is closely associated with the proper separation of the translational and internal degrees of freedom of the system, and has arisen in a number of fields, including the theory of nucleation. There are other problems associated with exponential dependence of cluster probability on the work of formation of the cluster, and also with rareness of some important clusters. In the latter case, simulative "umbrella sampling" does not always solve the entire problem. The present study is confined to clusters that appear in rarefied gases. Such systems are important in a number of scenarios, including nucleation processes. Several cluster models are considered including those consisting of molecules confined to a "container" of fixed volume and those constructed on the center of mass of the cluster. Connections between them are derived and rigorous solutions to the mapping problem are derived. Quantitative measures for the accuracy of approximate solutions, applied to cases in which the cluster is compact, are provided and exact solutions are provided even for the noncompact case. Some surprising results emerge from the study, among which is the fact that a cluster whose location is determined by one of its molecules, does not always have a

  2. Determinants of performance of supplemental immunization activities for polio eradication in Uttar Pradesh, India: social mobilization activities of the Social mobilization Network (SM Net and Core Group Polio Project (CGPP

    Weiss William M

    2013-01-01

    Full Text Available Abstract Background The primary strategy to interrupt transmission of wild poliovirus in India is to improve supplemental immunization activities (SIAs and routine immunization coverage in priority districts. The CORE Group, part of the Social Mobilization Network (SM Net, has been successful in improving SIA coverage in high-risk areas of Uttar Pradesh (UP. The SM Net works through community level mobilisers (from the CORE Group and UNICEF and covers more than 2 million children under the age of five. In this paper, we examine the reasons the CORE Group had been successful through exploration of which social mobilization activities of the CORE Group predicted better performance of SIAs. Methods We carried out a secondary data analysis of routine monitoring information collected by the CORE Group and the Government of India for SIAs. These data included information about vaccination outcomes of SIAs in CORE Group areas and non-CORE Group areas within the districts where the CORE Group operates, along with information about the number of various social mobilization activities carried out for each SIA. We employed Generalized Linear Latent and Mixed Model (GLLAMM statistical analysis methods to identify which social mobilization activities predicted SIA performance, and to account for the intra-class correlation (ICC between multiple observations within the same geographic areas over time. Results The number of mosque announcements carried out was the most consistent determinant of improved SIA performance across various performance measures. The number of Bullawa Tollies carried out also appeared to be an important determinant of improved SIA performance. The number of times other social mobilization activities were carried out did not appear to determine better SIA performance. Conclusions Social mobilization activities can improve the performance of mass vaccination campaigns. In the CORE Group areas, the number of mosque announcements and

  3. Making an Ice Core.

    Kopaska-Merkel, David C.

    1995-01-01

    Explains an activity in which students construct a simulated ice core. Materials required include only a freezer, food coloring, a bottle, and water. This hands-on exercise demonstrates how a glacier is formed, how ice cores are studied, and the nature of precision and accuracy in measurement. Suitable for grades three through eight. (Author/PVD)

  4. Ice Core Investigations

    Krim, Jessica; Brody, Michael

    2008-01-01

    What can glaciers tell us about volcanoes and atmospheric conditions? How does this information relate to our understanding of climate change? Ice Core Investigations is an original and innovative activity that explores these types of questions. It brings together popular science issues such as research, climate change, ice core drilling, and air…

  5. Antiviral Activity of Gold/Copper Sulfide Core/Shell Nanoparticles against Human Norovirus Virus-Like Particles.

    Jessica Jenkins Broglie

    Full Text Available Human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. Methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (NPs is a more universal and attractive alternative to other physical and chemical approaches. Using norovirus GI.1 (Norwalk virus-like particles (VLPs as a model viral system, this study characterized the antiviral activity of Au/CuS core/shell nanoparticles (NPs against GI.1 VLPs for the rapid inactivation of HuNoV. Inactivation of VLPs (GI.1 by Au/CuS NPs evaluated using an absorbance-based ELISA indicated that treatment with 0.083 μM NPs for 10 min inactivated ~50% VLPs in a 0.37 μg/ml VLP solution and 0.83 μM NPs for 10 min completely inactivated the VLPs. Increasing nanoparticle concentration and/or VLP-NP contact time significantly increased the virucidal efficacy of Au/CuS NPs. Changes to the VLP particle morphology, size, and capsid protein were characterized using dynamic light scattering, transmission electron microscopy, and Western blot analysis. The strategy reported here provides the first reported proof-of-concept Au/CuS NPs-based virucide for rapidly inactivating human norovirus.

  6. Activation of muscarinic and nicotinic acetylcholine receptors in the nucleus accumbens core is necessary for the acquisition of drug reinforcement.

    Crespo, Jose A; Sturm, Katja; Saria, Alois; Zernig, Gerald

    2006-05-31

    Neurotransmitter release in the nucleus accumbens core (NACore) during the acquisition of remifentanil or cocaine reinforcement was determined in an operant runway procedure by simultaneous tandem mass spectrometric analysis of dopamine, acetylcholine, and remifentanil or cocaine itself. Run times for remifentanil or cocaine continually decreased over the five consecutive runs of the experiment. Intra-NACore dopamine, acetylcholine, and drug peaked with each intravenous remifentanil or cocaine self-administration and decreased to pre-run baseline with half-lives of approximately 10 min. As expected, remifentanil or cocaine peaks did not vary between the five runs. Surprisingly, however, drug-contingent dopamine peaks also did not change over the five runs, whereas acetylcholine peaks did. Thus, the acquisition of drug reinforcement was paralleled by a continuous increase in acetylcholine overflow in the NACore, whereas the overflow of dopamine, the expected prime neurotransmitter candidate for conditioning in drug reinforcement, did not increase. Local intra-accumbens administration by reverse microdialysis of either atropine or mecamylamine completely and reversibly blocked the acquisition of remifentanil reinforcement. Our findings suggest that activation of muscarinic and nicotinic acetylcholine receptors in the NACore by acetylcholine volume transmission is necessary during the acquisition phase of drug reinforcement conditioning.

  7. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. II. Nanoflare Trains

    Barnes, W T; Bradshaw, S J

    2016-01-01

    Despite its prediction over two decades ago, the detection of faint, high-temperature ("hot") emission due to nanoflare heating in non-flaring active region cores has proved challenging. Using an efficient two-fluid hydrodynamic model, this paper investigates the properties of the emission expected from repeating nanoflares (a nanoflare train) of varying frequency as well as the separate heating of electrons and ions. If the emission measure distribution ($\\mathrm{EM}(T)$) peaks at $T = T_m$, we find that $\\mathrm{EM}(T_m)$ is independent of details of the nanoflare train, and $\\mathrm{EM}(T)$ above and below $T_m$ reflects different aspects of the heating. Below $T_m$ the main influence is the relationship of the waiting time between successive nanoflares to the nanoflare energy. Above $T_m$ power-law nanoflare distributions lead to an extensive plasma population not present in a monoenergetic train. Furthermore, in some cases characteristic features are present in $\\mathrm{EM}(T)$. Such details may be detec...

  8. A new method based on low background instrumental neutron activation analysis for major, trace and ultra-trace element determination in atmospheric mineral dust from polar ice cores

    Baccolo, Giovanni, E-mail: giovanni.baccolo@mib.infn.it [Graduate School in Polar Sciences, University of Siena, Via Laterina 8, 53100, Siena (Italy); Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Clemenza, Massimiliano [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Delmonte, Barbara [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); Maffezzoli, Niccolò [Centre for Ice and Climate, Niels Bohr Institute, Juliane Maries Vej, 30, 2100, Copenhagen (Denmark); Nastasi, Massimiliano; Previtali, Ezio [INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Department of Physics, University of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy); Prata, Michele; Salvini, Andrea [LENA, University of Pavia, Pavia (Italy); Maggi, Valter [Department of Environmental Sciences, University of Milano-Bicocca, P.zza della Scienza 1, 20126, Milano (Italy); INFN, Section of Milano-Bicocca, P.zza della Scienza 3, 20126, Milano (Italy)

    2016-05-30

    Dust found in polar ice core samples present extremely low concentrations, in addition the availability of such samples is usually strictly limited. For these reasons the chemical and physical analysis of polar ice cores is an analytical challenge. In this work a new method based on low background instrumental neutron activation analysis (LB-INAA) for the multi-elemental characterization of the insoluble fraction of dust from polar ice cores is presented. Thanks to an accurate selection of the most proper materials and procedures it was possible to reach unprecedented analytical performances, suitable for ice core analyses. The method was applied to Antarctic ice core samples. Five samples of atmospheric dust (μg size) from ice sections of the Antarctic Talos Dome ice core were prepared and analyzed. A set of 37 elements was quantified, spanning from all the major elements (Na, Mg, Al, Si, K, Ca, Ti, Mn and Fe) to trace ones, including 10 (La, Ce, Nd, Sm, Eu, Tb, Ho, Tm, Yb and Lu) of the 14 natural occurring lanthanides. The detection limits are in the range of 10{sup −13}–10{sup −6} g, improving previous results of 1–3 orders of magnitude depending on the element; uncertainties lies between 4% and 60%. - Highlights: • A new method based on neutron activation for the multi-elemental characterization of atmospheric dust entrapped in polar ice cores is proposed. • 37 elements were quantified in μg size dust samples with detection limits ranging from 10{sup −13} to 10{sup −6} g. • A low background approach and a clean analytical protocol improved INAA performances to unprecedented levels for multi-elemental analyses.

  9. A preliminary study on the behavior of trace elements in sediment cores from Ilha Grande (Rio de Janeiro State) by neutron activation analysis

    Wasserman, Julio Cesar [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Geoquimica; Figueiredo, Ana Maria G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Figueira, Andre Luiz [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Oceanografia; Kelecom, Alphonse [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. de Biologia Geral

    2002-07-01

    The present work aims to identify atmospheric and marine inputs of 9 metals (Ba, Co, Cr, Cs, Fe, Hf, Rb, Sc, Zn), 8 rare earths (La, Ce, Nd, Sm, Eu, Tb, Yb e Lu), 2 actinides (U, Th) and 3 non-metals (As, Sb, Se) in sediment cores from a remote area, the Biological Reserve of Praia do Sul, Ilha Grande, Rio de Janeiro, Brazil. The sediment cores were sampled in a peat bog (out of the tidal reach) and in a mangrove, downstream of the peat bog. The analytical technique employed was Instrumental Neutron Activation Analysis. The samples were irradiated for 16 hours at a thermal neutron flux of 10{sup 12} n cm{sup -2} s{sup -1} at the IEA-R1 reactor of IPEN. The measurements of the induced gamma-ray activity were carried out by high resolution gamma spectrometry, with an hyperpure Ge detector. A preliminary sediment dating with Po-210 was also carried out by applying radiochemical procedures and measurements were done in an Alfa spectrometer The results indicate that the peat bog core present a slight surface enrichment that can be attributed to atmospheric inputs. Increasing concentrations of metals with age is probably due to history of soil occupation. In the mangrove core, no significant increase in concentration could be detected in the surface sediments (except for Zn) confirming the suitability of the peat bog core as a tracer for atmospheric inputs. (author)

  10. Student Center Activities Aligned to the Common Core State Standards in English Language Arts and Literacy in History/Social Studies, Science, and Technical Subjects K-5

    Verhagen, Connie

    2012-01-01

    This publication helps educators create differentiated reading instruction experiences for their students by showing the relationship between two distinct resources: Student Center Activities (SCAs) and the Common Core State Standards (CCSSs). Reading specialists, reading coaches, and teachers will find this document useful in lesson planning, as…

  11. Dioxygen activation at a mononuclear Cu(I) center embedded in the calix[6]arene-tren core.

    Izzet, Guillaume; Zeitouny, Joceline; Akdas-Killig, Huriye; Frapart, Yves; Ménage, Stéphane; Douziech, Bénédicte; Jabin, Ivan; Le Mest, Yves; Reinaud, Olivia

    2008-07-23

    The reaction of a cuprous center coordinated to a calix[6]arene-based aza-cryptand with dioxygen has been studied. In this system, Cu(I) is bound to a tren unit that caps the calixarene core at the level of the small rim. As a result, although protected from the reaction medium by the macrocycle, the metal center presents a labile site accessible to small guest ligands. Indeed, in the presence of O2, it reacts in a very fast and irreversible redox process, leading, ultimately, to Cu(II) species. In the coordinating solvent MeCN, a one electron exchange occurs, yielding the corresponding [CalixtrenCu-MeCN](2+) complex with concomitant release of superoxide in the reaction medium. In a noncoordinating solvent such as CH2Cl2, the dioxygen reaction leads to oxygen insertions into the ligand itself. Both reactions are proposed to proceed through the formation of a superoxide-Cu(II) intermediate that is unstable in the Calixtren environment due to second sphere effects. The transiently formed superoxide ligand either undergoes fast substitution for a guest ligand (in MeCN) or intramolecular redox evolutions toward oxygenation of Calixtren. Interestingly, the latter process was shown to occur twice on the same ligand, thus demonstrating a possible catalytic activation of O2 at a single cuprous center. Altogether, this study illustrates the oxidizing power of a [CuO2](+) adduct and substantiates a mechanism by which copper mono-oxygenases such as DbetaH and PHM activate O2 at the Cu(M) center to produce such an intermediate capable of C-H breaking before the electron input provided by the noncoupled Cu(H) center.

  12. Probing the segmental mobility and energy of the active zones of a protein chain (aspartic acid protease) by a coarse-grained bond-fluctuation Monte Carlo simulation

    Pandey, Ras; Farmer, Barry

    2008-03-01

    A protein chain such as aspartic acid protease is described by a specific sequence of 99 residues each with its own specific characteristics. In a coarse-grained description, the backbone of a protein chain is described by nodes tethered together by peptide bonds where each node (the amino acid group) is characterized by molecular weight and hydrophobicity. A well-developed and somewhat mature computational modeling tool for the polymer chain such as the bond-fluctuation model is used to study such a specific protein chain with its constitutive amino groups and their sequence. The relative magnitude of hydrophobicity is used to develop appropriate interaction potentials for these amino acid groups in explicit solvent. The Metropolis algorithm is used to move each node and solvent constituent. Local energy and mobility of each amino group are analyzed along with global energy, mobility, and conformation of the protein chain. Effect of the solvent interaction and its concentration on these quantities will be presented.

  13. Core promoter-specific gene regulation: TATA box selectivity and Initiator-dependent bi-directionality of serum response factor-activated transcription.

    Xu, Muyu; Gonzalez-Hurtado, Elsie; Martinez, Ernest

    2016-04-01

    Gene-specific activation by enhancers involves their communication with the basal RNA polymerase II transcription machinery at the core promoter. Core promoters are diverse and may contain a variety of sequence elements such as the TATA box, the Initiator (INR), and the downstream promoter element (DPE) recognized, respectively, by the TATA-binding protein (TBP) and TBP-associated factors of the TFIID complex. Core promoter elements contribute to the gene selectivity of enhancers, and INR/DPE-specific enhancers and activators have been identified. Here, we identify a TATA box-selective activating sequence upstream of the human β-actin (ACTB) gene that mediates serum response factor (SRF)-induced transcription from TATA-dependent but not INR-dependent promoters and requires the TATA-binding/bending activity of TBP, which is otherwise dispensable for transcription from a TATA-less promoter. The SRF-dependent ACTB sequence is stereospecific on TATA promoters but activates in an orientation-independent manner a composite TATA/INR-containing promoter. More generally, we show that SRF-regulated genes of the actin/cytoskeleton/contractile family tend to have a TATA box. These results suggest distinct TATA-dependent and INR-dependent mechanisms of TFIID-mediated transcription in mammalian cells that are compatible with only certain stereospecific combinations of activators, and that a TBP-TATA binding mechanism is important for SRF activation of the actin/cytoskeleton-related gene family.

  14. Differential activation of accumbens shell and core dopamine by sucrose reinforcement with nose poking and with lever pressing.

    Bassareo, V; Cucca, F; Frau, R; Di Chiara, G

    2015-11-01

    In order to investigate the role of modus operandi in the changes of nucleus accumbens (NAc) dopamine (DA) transmission in sucrose reinforcement, extracellular DA was monitored by microdialysis in the NAc shell and core of rats trained on a fixed-ratio 1 schedule to respond for sucrose pellets by nose poking and lever pressing respectively. After training, rats were tested on three different sessions: sucrose reinforcement, extinction and passive sucrose presentation. In rats responding by nose poking dialysate DA increased in the shell but not in the core under reinforced as well as under extinction sessions. In contrast, in rats responding by lever pressing dialysate DA increased both in the accumbens shell and core under reinforced and extinction sessions. Response non-contingent sucrose presentation increased dialysate DA in the shell and core of rats trained to respond for sucrose by nose poking as well as in those trained by lever pressing. In rats trained to respond for sucrose by nose poking on a FR5 schedule dialysate DA also increased selectively in the NAc shell during reinforced responding and in both the shell and core under passive sucrose presentation. These findings, while provide an explanation for the discrepancies existing in the literature over the responsiveness of shell and core DA in rats responding for food, are consistent with the notion that NAc shell and core DA encode different aspects of reinforcement.

  15. Application study of the components Activity and Participation of the ICF Checklist used in people with Multiple Sclerosis and its relation to the Core Sets

    Rosé Colom Toldrá

    2016-10-01

    Full Text Available Introduction: The Core Set is a group of typical and significant functionality categories of the International Classification of Functioning, Disability and Health – ICF used for certain health conditions. Objective: The study reviewed the application of the component categories Activities and Participation based on the ICF Checklist for multiple sclerosis (MS and its relationship with the comprehensive and validated Core Sets by occupational therapists. Method: Descriptive quantitative research from collection and organization of data questionnaire based on the components Activities and Participation of the ICF Checklist - Version 2.1ª. Clinical form for the ICF containing 25 categories belonging to 6 domains and analysis of its relationship with the Core Sets. Participated 115 people with relapsing-remitting MS without disability to moderate disability, treated at the Central Institute of Hospital Clinics of the Faculty of Medicine University of São Paulo. We created database in Excel and made descriptive analysis of frequencies. Results: Most participants were women (85, mean age 32 years and 1 month (± 7.4. Study broadens the evidence of the applicability of the Comprehensive Core Set with 88% (22 and Core Set validated by occupational therapists with 72% (18 compared evaluated categories. More significant difficulties were encountered in the categories d640 Doing housework, d430 Lifting and carrying objects and d850 Remunerative employment, which reflected on the performance of various activities and social participation. Conclusion: Studies on application of the Core Set validated by occupational therapists are recommended to extend the evidence of professional clinical practice and inclusion of categories depending on the context.

  16. Core-shell structured α-Fe2O3@TiO2 nanocomposites with improved photocatalytic activity in the visible light region.

    Xia, Yubing; Yin, Longwei

    2013-11-14

    The core-shell structured Fe2O3@TiO2 nanocomposites prepared via a heteroepitaxial growth route using the Fe2O3 spindle as a hard template display improved photocatalytic degradation activity for Rhodamine B dye under visible light irradiation. The ratio of α-Fe2O3 : TiO2 in the α-Fe2O3@TiO2 core-shell nanocomposites can be tuned by etching the α-Fe2O3 core via controlling the concentration of HCl and etching time. An appropriate concentration of the Fe2O3 core could effectively induce a transition of the optical response from the UV to the visible region and decrease the recombination rate of photogenerated electrons and the holes of the core-shell structured catalyst, greatly contributing to the enhancement of visible light response and visible light photocatalytic activity of the Fe2O3@TiO2 catalysts. It is revealed that the optical response and photocatalytic performance of the core-shell α-Fe2O3@TiO2 nanocomposites can be tuned by adjusting the molar ratio of Fe2O3 : TiO2 of the α-Fe2O3@TiO2 nanocomposites. The α-Fe2O3@TiO2 core-shell nanocomposite with an optimal molar ratio of 7% for Fe2O3 : TiO2 exhibits the best photocatalytic performance under visible light irradiation. It is shown that the Fe2O3/TiO2 heterojunction structure is responsible for the efficient visible-light photocatalytic activity. As the concentration of Fe2O3 is high, Fe(3+) ions will act as recombination centres of the photogenerated electrons and holes. The present core-shell Fe2O3@TiO2 nanoparticles displaying enhanced photodegradation activity could find potential applications as photocatalysts for the abatement of various organic pollutants.

  17. Effect of Silicon on Activity Coefficients of Siderophile Elements (P, Au, Pd, As, Ge, Sb, and In) in Liquid Fe, with Application to Core Formation

    Righter, K.; Pando, K.; Danielson, L. R.; Humayun, M.; Righter, M.; Lapen, T.; Boujibar, A.

    2016-01-01

    Earth's core contains approximately 10 percent light elements that are likely a combination of S, C, Si, and O, with Si possibly being the most abundant. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE) in Fe liquids, and thus the partitioning behavior of those elements between core and mantle. The effect of Si can be small such as for Ni and Co, or large such as for Mo, Ge, Sb, As. The effect of Si on many siderophile elements is unknown yet could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of P, Au, Pd, and many other SE between metal and silicate melt. The results will be applied to Earth, for which we have excellent constraints on the mantle siderophile element concentrations.

  18. Correlation between blood glucose fluctuations and activation of oxidative stress in type 1 diabetic children during the acute metabolic disturbance period

    WU Di; GONG Chun-xiu; MENG Xi; YANG Qiu-lan

    2013-01-01

    Background Studies have shown that complications in type 1 diabetes mellitus (T1DM) in children are mainly due to oxidative stress (OS).Lipid peroxidation is the main marker of OS and iso-prostaglandin is a reliable biomarker of lipid peroxidation in type 2 diabetes mellitus (T2DM).However,there have been few studies on OS in T1DM children with hyperglycemia and glucose fluctuations.Methods We prospectively enrolled 23 newly diagnosed T1DM patients and 23 age and sex matched healthy controls in Beijing Children's Hospital from May 2010 to January 2011.They were treated with continuous subcutaneous insulin injection (CSII) and monitored by continuous glucose monitoring system (CGMS).Twenty-four-hour urine samples were collected to measure the concentration of 8-iso prostaglandin F2α (8-isoPGF2α).Samples taken from diabetic children were collected at days 8 to 10 after insulin treatment.Intraday glucose fluctuations were assessed by mean amplitude of glucose excursions (MAGE),largest amplitude of glycemic excursions (LAGE),standard deviation of blood glucose (SDBG) and number of glycemic excursions (NGE).The correlations between glucose parameters and the index of oxidative stress were analyzed.Results Urine 8-isoPGF2α in the T1DM group was higher than that in the control group ((967.70±412.68) ng vs.(675.23±354.59) ng,P=0.019).There was a correlation between urine 8-isoPGF2α level and MAGE (r=0.321,P=-0.039),a significant correlation between low-density lipoprotein and urine 8-isoPGF2α level (r=0.419,P=0.03).There was no significant correlation between urine 8-isoPGF2α level and blood pressure,glycosylated hemoglobin (HbA1c),fasting C-peptide or other lipid indices.Conclusion A correlation between urine 8-isoPGF2α levels and MAGE and low-density lipoprotein was found in children newly diagnosed with T1DM.

  19. Active layer-incorporated, spectrally tuned Au/SiO2 core/shell nanorod-based light trapping for organic photovoltaics.

    Janković, Vladan; Yang, Yang Michael; You, Jingbi; Dou, Letian; Liu, Yongsheng; Cheung, Puilam; Chang, Jane P; Yang, Yang

    2013-05-28

    We demonstrate that incorporation of octadecyltrimethoxysilane (OTMS)-functionalized, spectrally tuned, gold/silica (Au/SiO2) core/shell nanospheres and nanorods into the active layer of an organic photovoltaic (OPV) device led to an increase in photoconversion efficiency (PCE). A silica shell layer was added onto Au core nanospheres and nanorods in order to provide an electrically insulating surface that does not interfere with carrier generation and transport inside the active layer. Functionalization of the Au/SiO2 core/shell nanoparticles with the OTMS organic ligand was then necessary to transfer the Au/SiO2 core/shell nanoparticles from an ethanol solution into an OPV polymer-compatible solvent, such as dichlorobenzene. The OTMS-functionalized Au/SiO2 core/shell nanorods and nanospheres were then incorporated into the active layers of two OPV polymer systems: a poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCB60M) OPV device and a poly[2,6-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,4-b]dithiophene-alt-5-dibutyloctyl-3,6-bis(5-bromothiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione] (PBDTT-DPP:PC60BM) OPV device. For the P3HT:PC60BM polymer with a band edge of ~700 nm, the addition of the core/shell nanorods with an aspect ratio (AR) of ~2.5 (extinction peak ~670 nm) resulted in a 7.1% improvement in PCE, while for the PBDTT-DPP:PC60BM polymer with a band edge of ~860 nm, the addition of core/shell nanorods with an AR of ~4 (extinction peak ~830 nm) resulted in a 14.4% improvement in PCE. The addition of Au/SiO2 core/shell nanospheres to the P3HT:PC60BM polymer resulted in a 2.7% improvement in PCE, while their addition to a PBDTT-DPP:PC60BM polymer resulted in a 9.1% improvement. The PCE and Jsc enhancements were consistent with external quantum efficiency (EQE) measurements, and the EQE enhancements spectrally matched the extinction spectra of Au/SiO2 nanospheres and nanorods in both OPV polymer systems.

  20. Significance of the hepatitis C virus (HCV core antigen as an alternative plasma marker of active HCV infection

    Daniel HDJ

    2007-01-01

    Full Text Available Purpose: To evaluate the role of core antigen (Ortho trak-C assay as a marker of active HCV infection in comparison to HCV RNA as detected by reverse transcription polymerase chain reaction (RT-PCR. Methods: This evaluation was carried out during January 2000 to December 2003 in HCV infected individuals who were treatment naοve or were on anti-viral therapy. Additionally, sequential plasma samples from patients on clinical follow-up were included in this study. A total of 167 samples from 61 patients were tested by trak-C and RT-PCR. HCV RNA detection was achieved by a RT-PCR. Trak-C assay results were also compared in a limited proportion of these samples with known HCV viral load and genotype. Results: Of 167 samples tested, 56.9% were RNA positive and 43.1% were RNA negative while 50.3% were trak-C positive and 49.7% were trak-C negative, yielding a sensitivity of 85.3% and a specificity of 95.8% for the trak-C assay (Kappa co-efficient = 0.8. The concentration of HCVcAg and HCV RNA showed significant correlation (n=38, r=0.334, P =0.04. The trak-C assay detected the most prevalent HCV genotypes in India without significant difference ( P =0.335. The difference between mean absorbance values of HCV RNA positive samples compared to HCV RNA negative samples in the trak-C assay was highly significant ( P < 0.000. Qualitative results of trak-C assay and RT-PCR were comparable in 93% of follow-up samples. Conclusions: Trak-C assay can be recommended for confirmation of HCV infection and follow-up in laboratories with resource-poor facilities.

  1. Dwelling Quietly in the Rich Club: Brain Network Determinants of Slow Cortical Fluctuations

    Gollo, Leonardo L; Hutchison, R Matthew; Heuvel, Martijn van den; Breakspear, Michael

    2016-01-01

    For more than a century, cerebral cartography has been driven by investigations of structural and morphological properties of the brain across spatial scales and the temporal/functional phenomena that emerge from these underlying features. The next era of brain mapping will be driven by studies that consider both of these components of brain organization simultaneously -- elucidating their interactions and dependencies. Using this guiding principle, we explored the origin of slowly fluctuating patterns of synchronization within the topological core of brain regions known as the rich club, implicated in the regulation of mood and introspection. We find that a constellation of densely interconnected regions that constitute the rich club (including the anterior insula, amygdala, and precuneus) play a central role in promoting a stable, dynamical core of spontaneous activity in the primate cortex. The slow time scales are well matched to the regulation of internal visceral states, corresponding to the somatic cor...

  2. Primordial Fluctuations within Teleparallelism

    Wu, Yi-Peng

    2011-01-01

    To study the primordial fluctuations for gravity within teleparallelism, we perform a 3+1 decomposition of the vierbein field which makes the metric tensor identical to the ADM formulation. The torsion scalar is differ by a total divergence from the Ricci scalar under this representation as a consistent result. Using the unitary gauge of the scalar field, we obtain the same quadratic actions for both scalar and tensor perturbations as the standard ones in the minimal torsion scalar coupling. When the same scenario is applied to the higher-order action, $f(T)$ gravity, we find that the scalar-tensor coupling in the Einstein frame becomes a total divergence. Consequently, the cosmological perturbations are the same for $f(T)$ and $f(R)$ gravity theories in the earlier universe although the behaviors of the late time cosmic acceleration are apparently different.

  3. Fluctuating structure of aqueous organic nanodroplets

    Hrahsheh, Fawaz; Wilemski, Gerald

    2013-05-01

    Supercooled and nano-confined water occurs frequently as nanometer-sized aqueousorganic aerosol droplets that are ubiquitous in the atmosphere and in many industrial processes. Nanodroplet structure is important because it influences droplet growth and evaporation rates, heterogeneous reaction rates, and radiative properties. We used classical molecular dynamic simulations to study the structure of binary water-nonane and ternary water-butanol-nonane nanodroplets for several temperatures and droplet sizes. We found that nonspherical, phase-separated Russian Doll (RD) structures occur for water/nonane nanodroplets at all temperatures studied, 220K-300K. The RD structure consists of a nearly spherical water droplet partially wetted by a convex lens of nonane. We then studied the effects of butanol on the wetting of the water/butanol core-shell droplet by the nonane lens. At low concentrations, butanol acts as a surfactant to significantly enhance the wetability of the water droplet by nonane. At 250 K, with sufficient butanol and nonane, perfect wetting (thin film formation by nonane) occurs. Perfect wetting also occurs at higher temperatures, 270 K to 300 K, but this wetting state is progressively destabilized at higher temperature. All of the nanodroplets studied undergo distinct transitions between partial dewetting and perfect wetting states due to isothermal fluctuations in the local distribution of butanol on the surface of the water core. These fluctuations favor the wetted state at lower temperatures and the dewetted state at higher temperatures.

  4. Transport generated by dichotomous fluctuations

    Kula, J.; Czernik, T.; łuczka, J.

    1996-02-01

    Overdamped motion of Brownian particles in spatially periodic potentials and subjected to fluctuations modeled by asymmetric exponentially correlated two-state noise of zero mean value is considered. The probability current is presented in a closed form and analyzed in asymptotic regimes of very long and very short correlation times of the fluctuations. Explicit results are obtained for a piecewise linear potential. The role of correlations and temporal asymmetry of fluctuations is elucidated.

  5. Synthesis, Characterization, and Investigation of Visible Light Photocatalytic Activity of C Doped TiO2/CdS Core-Shell Nanocomposite

    Atul B. Lavand

    2015-01-01

    Full Text Available Carbon (C doped TiO2/CdS core-shell nanocomposite (C/TiO2/CdS was synthesized using microemulsion method. Synthesized powder was characterized using X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, energy dispersive X-ray spectroscopy (EDX, transmission electron microscopy (TEM, and UV-visible spectrophotometery. TEM images reveal that C/TiO2/CdS core-shell heterostructure is successfully prepared with CdS as a core and C doped TiO2 as a shell. UV-visible absorption spectra show that CdS nanoparticles act as a sensitizer and effectively enhance the photoabsorption capacity of C/TiO2/CdS nanocomposite in visible region. Visible light photocatalytic activity of synthesized nanocomposite was evaluated for the degradation of methylene blue. C/TiO2/CdS core-shell nanocomposite exhibits better photocatalytic activity as compared to bare TiO2, CdS, CdS/TiO2, and C doped TiO2.

  6. Fabrication of SnO2-TiO2 core-shell nanopillar-array films for enhanced photocatalytic activity

    Cheng, Hsyi-En; Lin, Chun-Yuan; Hsu, Ching-Ming

    2017-02-01

    Immobilized or deposited thin film TiO2 photocatalysts are suffering from a low photocatalytic activity due to either a low photon absorption efficiency or a high carrier recombination rate. Here we demonstrate that the photocatalytic activity of TiO2 can be effectively improved by the SnO2-TiO2 core-shell nanopillar-array structure which combines the benefits of SnO2/TiO2 heterojunction and high reaction surface area. The SnO2-TiO2 core-shell nanopillar-array films were fabricated using atomic layer deposition and dry etching techniques via barrier-free porous anodic alumina templates. The photocatalytic activity of the prepared films was evaluated by methylene blue (MB) bleaching under 352 nm UV light irradiation. The results show that the photocatalytic activity of TiO2 film was 45% improved by introducing a SnO2 film between TiO2 and ITO glass substrate and was 300% improved by using the SnO2-TiO2 core-shell nanopillar-array structure. The 45% improvement by the SnO2 interlayer is attributed to the SnO2/TiO2 heterojunction which separates the photogenerated electron-hole pairs in TiO2 for MB degradation, and the high photocatalytic activity of the SnO2-TiO2 core-shell nanopillar-array films is attributed to the three dimensional SnO2/TiO2 heterojunction which owns both the carrier separation ability and the high photocatalytic reaction surface area.

  7. Novel of core-shell AlOOH/Cu nanostructures: Synthesis, characterization, antimicrobial activity and in vitro toxicity in Neuro-2a cells

    Bakina, O. V.; Fomenko, A. N.; Korovin, M. S.; Glazkova, E. A.; Svarovskaya, N. V.

    2016-08-01

    Core-shell micro/nanostructures were fabricated by the reaction of Al/Cu bimetallic nanoparticles with water. Al/Cu nanoparticles have been obtained using the method of simultaneous electrical explosion of a pair of the corresponding metal wires in an argon atmosphere. The nanoparticles are chemically active and interact with water at 60°C to form core-shell micro/nanostructures. The obtained products were characterized by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic light scattering and the nitrogen adsorption method. The antibacterial activity of the synthesized structures was investigated against E. coli and St. aureus. The toxic effect of these nanostructures against the Neuro-2a neuroblastoma cell line was investigated. AlOOH/Cu nanostructures are shown to inhibit cell proliferation. The AlOOH/Cu nanostructures are good candidates for medical applications.

  8. Fluctuation-Driven Neural Dynamics Reproduce Drosophila Locomotor Patterns.

    Andrea Maesani

    2015-11-01

    Full Text Available The neural mechanisms determining the timing of even simple actions, such as when to walk or rest, are largely mysterious. One intriguing, but untested, hypothesis posits a role for ongoing activity fluctuations in neurons of central action selection circuits that drive animal behavior from moment to moment. To examine how fluctuating activity can contribute to action timing, we paired high-resolution measurements of freely walking Drosophila melanogaster with data-driven neural network modeling and dynamical systems analysis. We generated fluctuation-driven network models whose outputs-locomotor bouts-matched those measured from sensory-deprived Drosophila. From these models, we identified those that could also reproduce a second, unrelated dataset: the complex time-course of odor-evoked walking for genetically diverse Drosophila strains. Dynamical models that best reproduced both Drosophila basal and odor-evoked locomotor patterns exhibited specific characteristics. First, ongoing fluctuations were required. In a stochastic resonance-like manner, these fluctuations allowed neural activity to escape stable equilibria and to exceed a threshold for locomotion. Second, odor-induced shifts of equilibria in these models caused a depression in locomotor frequency following olfactory stimulation. Our models predict that activity fluctuations in action selection circuits cause behavioral output to more closely match sensory drive and may therefore enhance navigation in complex sensory environments. Together these data reveal how simple neural dynamics, when coupled with activity fluctuations, can give rise to complex patterns of animal behavior.

  9. PTEN loss and chromosome 8 alterations in Gleason grade 3 prostate cancer cores predicts the presence of un-sampled grade 4 tumor: implications for active surveillance.

    Trock, Bruce J; Fedor, Helen; Gurel, Bora; Jenkins, Robert B; Knudsen, B S; Fine, Samson W; Said, Jonathan W; Carter, H Ballentine; Lotan, Tamara L; De Marzo, Angelo M

    2016-07-01

    Men who enter active surveillance because their biopsy exhibits only Gleason grade 3 (G3) frequently have higher grade tumor missed by biopsy. Thus, biomarkers are needed that, when measured on G3 tissue, can predict the presence of higher grade tumor in the whole prostate. We evaluated whether PTEN loss, chromosome 8q gain (MYC) and/or 8p loss (LPL) measured only on G3 cores is associated with un-sampled G4 tumor. A tissue microarray was constructed of prostatectomy tissue from patients whose prostates exhibited only Gleason score 3+3, only 3+4 or only 4+3 tumor (n=50 per group). Cores sampled only from areas of G3 were evaluated for PTEN loss by immunohistochemistry, and PTEN deletion, LPL/8p loss and MYC/8q gain by fluorescence in situ hybridization. Biomarker results were compared between Gleason score 6 vs 7 tumors using conditional logistic regression. PTEN protein loss, odds ratio=4.99, P=0.033; MYC/8q gain, odds ratio=5.36, P=0.010; and LPL/8p loss, odds ratio=3.96, P=0.003 were significantly more common in G3 cores derived from Gleason 7 vs Gleason 6 tumors. PTEN gene deletion was not statistically significant. Associations were stronger comparing Gleason 4+3 vs 6 than for Gleason 3+4 vs 6. MYC/8q gain, LPL/8p loss and PTEN protein loss measured in G3 tissue microarray cores strongly differentiate whether the core comes from a Gleason 6 or Gleason 7 tumor. If validated to predict upgrading from G3 biopsy to prostatectomy these biomarkers could reduce the likelihood of enrolling high-risk men and facilitate safe patient selection for active surveillance.

  10. Inverse scattering problem in turbulent magnetic fluctuations

    Treumann, Rudolf A.; Baumjohann, Wolfgang; Narita, Yasuhito

    2016-08-01

    We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctuation problem in terms of its electrodynamic turbulent response function, and reduce it to the solution of a special form of the famous Gelfand-Levitan-Marchenko equation of quantum mechanical scattering theory. The last of these applies to transmission and reflection in an active medium. The theory of turbulent magnetic fluctuations does not refer to such quantities. It requires a somewhat different formulation. We reduce the theory to the measurement of the low-frequency electromagnetic fluctuation spectrum, which is not the turbulent spectral energy density. The inverse theory in this form enables obtaining information about the turbulent response function of the medium. The dynamic causes of the electromagnetic fluctuations are implicit to it. Thus, it is of vital interest in low-frequency magnetic turbulence. The theory is developed until presentation of the equations in applicable form to observations of turbulent electromagnetic fluctuations as input from measurements. Solution of the final integral equation should be done by standard numerical methods based on iteration. We point to the possibility of treating power law fluctuation spectra as an example. Formulation of the problem to include observations of spectral power densities in turbulence is not attempted. This leads to severe mathematical problems and requires a reformulation of inverse scattering theory. One particular aspect of the present inverse theory of turbulent fluctuations is that its structure naturally leads to spatial information which is obtained from the temporal information that is inherent to the observation of time series. The Taylor assumption is not needed here. This is a consequence of Maxwell's equations, which couple space and time evolution. The inversion procedure takes advantage of a particular

  11. The Use of Cultural Historical Activity Theory (CHAT) within a Constructivist Learning Environment to Develop Core Competencies in Social Work

    Fire, Nancy; Casstevens, W. J.

    2013-01-01

    Achieving foundation-level practice behaviors to develop social work core competencies involves integrating learning across a curriculum. This article focuses on two phases of foundation-level course redevelopment aimed to support graduate students in accomplishing this outcome. The first phase involved restructuring the course to become a…

  12. Fluctuating Selection in the Moran

    Dean, Antony M.; Lehman, Clarence; Yi, Xiao

    2017-01-01

    Contrary to classical population genetics theory, experiments demonstrate that fluctuating selection can protect a haploid polymorphism in the absence of frequency dependent effects on fitness. Using forward simulations with the Moran model, we confirm our analytical results showing that a fluctuating selection regime, with a mean selection coefficient of zero, promotes polymorphism. We find that increases in heterozygosity over neutral expectations are especially pronounced when fluctuations are rapid, mutation is weak, the population size is large, and the variance in selection is big. Lowering the frequency of fluctuations makes selection more directional, and so heterozygosity declines. We also show that fluctuating selection raises dn/ds ratios for polymorphism, not only by sweeping selected alleles into the population, but also by purging the neutral variants of selected alleles as they undergo repeated bottlenecks. Our analysis shows that randomly fluctuating selection increases the rate of evolution by increasing the probability of fixation. The impact is especially noticeable when the selection is strong and mutation is weak. Simulations show the increase in the rate of evolution declines as the rate of new mutations entering the population increases, an effect attributable to clonal interference. Intriguingly, fluctuating selection increases the dn/ds ratios for divergence more than for polymorphism, a pattern commonly seen in comparative genomics. Our model, which extends the classical neutral model of molecular evolution by incorporating random fluctuations in selection, accommodates a wide variety of observations, both neutral and selected, with economy. PMID:28108586

  13. Fluctuation Relations for Molecular Motors

    Lacoste, David; Mallick, Kirone

    This review is focused on the application of specific fluctuation relations, such as the Gallavotti-Cohen relation, to ratchet models of a molecular motor. A special emphasis is placed on two-state models such as the flashing ratchet model. We derive the Gallavotti-Cohen fluctuation relation for these models and we discuss some of its implications.

  14. Fluctuations as stochastic deformation

    Kazinski, P. O.

    2008-04-01

    A notion of stochastic deformation is introduced and the corresponding algebraic deformation procedure is developed. This procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). This method is demonstrated on diverse relativistic and nonrelativistic models with finite and infinite degrees of freedom. It is shown that under stochastic deformation the model of a nonrelativistic particle interacting with the electromagnetic field on a curved background passes into the stochastic model described by the Fokker-Planck equation with the diffusion tensor being the inverse metric tensor. The first stochastic correction to the Newton equations for this system is found. The Klein-Kramers equation is also derived as the stochastic deformation of a certain classical model. Relativistic generalizations of the Fokker-Planck and Klein-Kramers equations are obtained by applying the procedure of stochastic deformation to appropriate relativistic classical models. The analog of the Fokker-Planck equation associated with the stochastic Lorentz-Dirac equation is derived too. The stochastic deformation of the models of a free scalar field and an electromagnetic field is investigated. It turns out that in the latter case the obtained stochastic model describes a fluctuating electromagnetic field in a transparent medium.

  15. Constructing a MoS₂ QDs/CdS Core/Shell Flowerlike Nanosphere Hierarchical Heterostructure for the Enhanced Stability and Photocatalytic Activity.

    Liang, Shijing; Zhou, Zhouming; Wu, Xiuqin; Zhu, Shuying; Bi, Jinhong; Zhou, Limin; Liu, Minghua; Wu, Ling

    2016-02-15

    MoS₂ quantum dots (QDs)/CdS core/shell nanospheres with a hierarchical heterostructure have been prepared by a simple microwave hydrothermal method. The as-prepared samples are characterized by XRD, TEM, SEM, UV-VIS diffuse reflectance spectra (DRS) and N₂-sorption in detail. The photocatalytic activities of the samples are evaluated by water splitting into hydrogen. Results show that the as-prepared MoS₂ QDs/CdS core/shell nanospheres with a diameter of about 300 nm are composed of the shell of CdS nanorods and the core of MoS₂ QDs. For the photocatalytic reaction, the samples exhibit a high stability of the photocatalytic activity and a much higher hydrogen evolution rate than the pure CdS, the composite prepared by a physical mixture, and the Pt-loaded CdS sample. In addition, the stability of CdS has also been greatly enhanced. The effect of the reaction time on the formations of nanospheres, the photoelectric properties and the photocatalytic activities of the samples has been investigated. Finally, a possible photocatalytic reaction process has also been proposed.

  16. Constructing a MoS2 QDs/CdS Core/Shell Flowerlike Nanosphere Hierarchical Heterostructure for the Enhanced Stability and Photocatalytic Activity

    Shijing Liang

    2016-02-01

    Full Text Available MoS2 quantum dots (QDs/CdS core/shell nanospheres with a hierarchical heterostructure have been prepared by a simple microwave hydrothermal method. The as-prepared samples are characterized by XRD, TEM, SEM, UV-VIS diffuse reflectance spectra (DRS and N2-sorption in detail. The photocatalytic activities of the samples are evaluated by water splitting into hydrogen. Results show that the as-prepared MoS2 QDs/CdS core/shell nanospheres with a diameter of about 300 nm are composed of the shell of CdS nanorods and the core of MoS2 QDs. For the photocatalytic reaction, the samples exhibit a high stability of the photocatalytic activity and a much higher hydrogen evolution rate than the pure CdS, the composite prepared by a physical mixture, and the Pt-loaded CdS sample. In addition, the stability of CdS has also been greatly enhanced. The effect of the reaction time on the formations of nanospheres, the photoelectric properties and the photocatalytic activities of the samples has been investigated. Finally, a possible photocatalytic reaction process has also been proposed.

  17. Fluctuation of the Download Network

    HAN Ding-Ding; LIV Jin-Gao; MA Yu-Gang

    2008-01-01

    The scaling behaviour of fluctuation for a download network we investigated a few years ago based upon Zhang's Econophysics web page is presented.A power law scaling,namely σ~α exists between the dispersion σ and average flux of the download rates.The fluctuation exponent α is neither 1/2 nor 1,which were claimed as two universal fluctuation classes in previous publication,while it varies from 1/2 to 1 with the time window in which the download data are accumulated.The crossover behaviour of fluctuation exponents can be qualitatively understood by the external driving fluctuation model for a small-size system or a network traffic model which suggests congestion as the origin.

  18. Fluctuations in peroxidase and catalase activities of resistant and susceptible black gram (Vigna mungo (L.) Hepper) genotypes elicited by Bemisia tabaci (Gennadius) feeding.

    Taggar, Gaurav Kumar; Gill, Ranjit Singh; Gupta, Anil Kumar; Sandhu, Jeet Singh

    2012-10-01

    Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleryrodidae), is a serious pest of black gram, (Vigna mungo (L.) Hepper), an important legume pulse crop grown in north India. This research investigated the potential role of selected plant oxidative enzymes in resistance/susceptibility to whitefly in nine black gram genotypes. Oxidative enzyme activity was estimated spectrophotometrically from leaf samples collected at 30 and 50 d after sowing (DAS) from whitefly infested and uninfested plants. The enzymes showed different activity levels at different times after the infestation. The results indicated that in general, whitefly infestation increased the activities of peroxidase and decreased the catalase activity. Resistant genotypes NDU 5-7 and KU 99-20 recorded higher peroxidase and catalase activities at 30 and 50 DAS under whitefly-stress conditions as compared with non-stressed plants. The results suggest that the enhanced activities of the enzymes may contribute to bioprotection of black gram plants against B. tabaci infestation. The potential mechanisms to explain the correlation of resistance to whitefly in black gram genotypes with higher activities of oxidative enzymes are also discussed.

  19. Correlation of within-individual fluctuation of depressed mood with prefrontal cortex activity during verbal working memory task: optical topography study

    Sato, Hiroki; Aoki, Ryuta; Katura, Takusige; Matsuda, Ryoichi; Koizumi, Hideaki

    2011-12-01

    Previous studies showed that interindividual variations in mood state are associated with prefrontal cortex (PFC) activity. In this study, we focused on the depressed-mood state under natural circumstances and examined the relationship between within-individual changes over time in this mood state and PFC activity. We used optical topography (OT), a functional imaging technique based on near-infrared spectroscopy, to measure PFC activity for each participant in three experimental sessions repeated at 2-week intervals. In each session, the participants completed a self-report questionnaire of mood state and underwent OT measurement while performing verbal and spatial working memory (WM) tasks. The results showed that changes in the depressed-mood score between successive sessions were negatively correlated with those in the left PFC activation for the verbal WM task (ρ = -0.56, p < 0.05). In contrast, the PFC activation for the spatial WM task did not co-vary with participants' mood changes. We thus demonstrated that PFC activity during a verbal WM task varies depending on the participant's depressed mood state, independent of trait factors. This suggests that using optical topography to measure PFC activity during a verbal WM task can be used as a potential state marker for an individual's depressed mood state.

  20. A 10,300-year-old permafrost core from the active rock glacier Lazaun, southern Ötztal Alps (South Tyrol, northern Italy)

    Krainer, Karl; Bressan, David; Dietre, Benjamin; Haas, Jean Nicolas; Hajdas, Irka; Lang, Kathrin; Mair, Volkmar; Nickus, Ulrike; Reidl, Daniel; Thies, Hansjörg; Tonidandel, David

    2015-03-01

    Two cores were drilled on rock glacier Lazaun in the southern Ötztal Alps (N Italy). The average ice content of core Lazaun I is 43 vol.% and of core Lazaun II is 22 vol.%. Radiocarbon dating of plant macrofossil remains of core Lazaun I yielded ages ranging from 8960 cal yr BP at a depth of ca. 23.5 m to 2240 cal yr BP at a depth of 2.8 m, indicating that the ice near the base is approximately 10,300 yr old. The rock glacier was intact since that time and the ice persisted even during warm periods of the Holocene. An ice-free debris layer between 16.8 and 14.7 m separates the rock glacier into two frozen bodies. Inclinometer measurements indicate that both frozen bodies are active and that deformation occurs within a shear horizon at a depth of 20-25 m at the base of the lower frozen body and to a minor extent at a depth of approximately 14 m at the base of the upper frozen body. The ice-free debris layer in the middle of the Lazaun rock glacier indicates a more than five centennial long drought period, which dates to about 4300-3740 cal yr BP.

  1. Dynamics of Hydrophobic Core Phenylalanine Residues Probed by Solid-State Deuteron NMR

    Vugmeyster, Liliya; Ostrovsky, Dmitry; Villafranca, Toni; Sharp, Janelle; Xu, Wei; Lipton, Andrew S.; Hoatson, Gina; Vold, Robert L.

    2015-11-03

    We conducted a detailed investigation of the dynamics of two phenylalanine side chains in the hydrophobic core of the villin headpiece subdomain protein (HP36) in the hydrated powder state over the 298–80 K temperature range. We utilized static deuteron NMR measurements of longitudinal relaxation and line shapes supplemented with computational modeling. The temperature dependence of the relaxation times reveals the presence of two main mechanisms that can be attributed to the ring-flips, dominating at high temperatures, and small-angle fluctuations, dominating at low temperatures. The relaxation is non- exponential at all temperatures with the extent of non-exponentiality increasing from higher to lower temperatures. This behavior suggests a distribution of conformers with unique values of activation energies. The central values of the activation energies for the ring-flipping motions are among the smallest reported for aromatic residues in peptides and proteins and point to a very mobile hydrophobic core. The analysis of the widths of the distributions, in combination with the earlier results on the dynamics of flanking methyl groups (Vugmeyster et al., J. Phys. Chem. 2013, 117, 6129–6137), suggests that the hydrophobic core undergoes concerted fluctuations. There is a pronounced effect of dehydration on the ring-flipping motions, which shifts the distribution toward more rigid conformers. The cross-over temperature between the regions of dominance of the small-angle fluctuations and ring-flips shifts from 195 K in the hydrated protein to 278 K in the dry one. This result points to the role of solvent in the onset of the concerted fluctuations of the core and highlights aromatic residues as markers of the protein dynamical transitions.

  2. Ice Cores

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature, precipitation, atmospheric trace gases, and other aspects of climate and environment derived from ice cores drilled on glaciers and ice...

  3. Core BPEL

    Hallwyl, Tim; Højsgaard, Espen

    extensions. Combined with the fact that the language definition does not provide a formal semantics, it is an arduous task to work formally with the language (e.g. to give an implementation). In this paper we identify a core subset of the language, called Core BPEL, which has fewer and simpler constructs......, does not allow omissions, and does not contain ignorable elements. We do so by identifying syntactic sugar, including default values, and ignorable elements in WS-BPEL. The analysis results in a translation from the full language to the core subset. Thus, we reduce the effort needed for working...... formally with WS-BPEL, as one, without loss of generality, need only consider the much simpler Core BPEL. This report may also be viewed as an addendum to the WS-BPEL standard specification, which clarifies the WS-BPEL syntax and presents the essential elements of the language in a more concise way...

  4. Altered baseline brain activity in experts measured by amplitude of low frequency fluctuations (ALFF): a resting state fMRI study using expertise model of acupuncturists.

    Dong, Minghao; Li, Jun; Shi, Xinfa; Gao, Shudan; Fu, Shijun; Liu, Zongquan; Liang, Fanrong; Gong, Qiyong; Shi, Guangming; Tian, Jie

    2015-01-01

    It is well established that expertise modulates evoked brain activity in response to specific stimuli. Recently, researchers have begun to investigate how expertise influences the resting brain. Among these studies, most focused on the connectivity features within/across regions, i.e., connectivity patterns/strength. However, little concern has been given to a more fundamental issue whether or not expertise modulates baseline brain activity. We investigated this question using amplitude of low-frequency (expertise model, i.e., acupuncturists, due to their robust proficiency in tactile perception and emotion regulation. After the psychophysical and behavioral expertise screening procedure, 23 acupuncturists and 23 matched non-acupuncturists (NA) were enrolled. Our results explicated higher ALFF for acupuncturists in the left ventral medial prefrontal cortex (VMPFC) and the contralateral hand representation of the primary somatosensory area (SI) (corrected for multiple comparisons). Additionally, ALFF of VMPFC was negatively correlated with the outcomes of the emotion regulation task (corrected for multiple comparisons). We suggest that our study may reveal a novel connection between the neuroplasticity mechanism and resting state activity, which would upgrade our understanding of the central mechanism of learning. Furthermore, by showing that expertise can affect the baseline brain activity as indicated by ALFF, our findings may have profound implication for functional neuroimaging studies especially those involving expert models, in that difference in baseline brain activity may either smear the spatial pattern of activations for task data or introduce biased results into connectivity-based analysis for resting data.

  5. Correlation of within-individual fluctuation of depressed mood with prefrontal cortex activity during verbal working memory task: optical topography study.

    Sato, Hiroki; Aoki, Ryuta; Katura, Takusige; Matsuda, Ryoichi; Koizumi, Hideaki

    2011-12-01

    Previous studies showed that interindividual variations in mood state are associated with prefrontal cortex (PFC) activity. In this study, we focused on the depressed-mood state under natural circumstances and examined the relationship between within-individual changes over time in this mood state and PFC activity. We used optical topography (OT), a functional imaging technique based on near-infrared spectroscopy, to measure PFC activity for each participant in three experimental sessions repeated at 2-week intervals. In each session, the participants completed a self-report questionnaire of mood state and underwent OT measurement while performing verbal and spatial working memory (WM) tasks. The results showed that changes in the depressed-mood score between successive sessions were negatively correlated with those in the left PFC activation for the verbal WM task (ρ = -0.56, p mood changes. We thus demonstrated that PFC activity during a verbal WM task varies depending on the participant's depressed mood state, independent of trait factors. This suggests that using optical topography to measure PFC activity during a verbal WM task can be used as a potential state marker for an individual's depressed mood state.

  6. Molybdenum-Doped PdPt@Pt Core-Shell Octahedra Supported by Ionic Block Copolymer-Functionalized Graphene as a Highly Active and Durable Oxygen Reduction Electrocatalyst.

    Cho, Kie Yong; Yeom, Yong Sik; Seo, Heun Young; Kumar, Pradip; Lee, Albert S; Baek, Kyung-Youl; Yoon, Ho Gyu

    2017-01-18

    Development of highly active and durable electrocatalysts that can effectively electrocatalyze oxygen reduction reactions (ORR) still remains one important challenge for high-performance electrochemical conversion and storage applications such as fuel cells and metal-air batteries. Herein, we propose the combination of molybdenum-doped PdPt@Pt core-shell octahedra and the pyrene-functionalized poly(dimethylaminoethyl methacrylate)-b-poly[(ethylene glycol) methyl ether methacrylate] ionic block copolymer-functionalized reduced graphene oxide (Mo-PdPt@Pt/IG) to effectively augment the interfacial cohesion of both components using a tunable ex situ mixing strategy. The rationally designed Mo-PdPt@Pt core-shell octahedra have unique compositional benefits, including segregation of Mo atoms on the vertexes and edges of the octahedron and 2-3 shell layers of Pt atoms on a PdPt alloy core, which can provide highly active sites to the catalyst for ORR along with enhanced electrochemical stability. In addition, the ionic block copolymer functionalized graphene can facilitate intermolecular charge transfer and good stability of metal NPs, which arises from the ionic block copolymer interfacial layer. When the beneficial features of the Mo-PdPt@Pt and IG are combined, the Mo-PdPt@Pt/IG exhibits substantially enhanced activity and durability for ORR relative to those of commercial Pt/C. Notably, the Mo-PdPt@Pt/IG shows mass activity 31-fold higher than that of Pt/C and substantially maintains high activities after 10 000 cycles of intensive durability testing. The current study highlights the crucial strategies in designing the highly active and durable Pt-based octahedra and effective combination with functional graphene supports toward the synergetic effects on ORR.

  7. Velocity fluctuations in polar solar wind: a comparison between different solar cycles

    B. Bavassano

    2009-02-01

    Full Text Available The polar solar wind is a fast, tenuous and steady flow that, with the exception of a relatively short phase around the Sun's activity maximum, fills the high-latitude heliosphere. The polar wind properties have been extensively investigated by Ulysses, the first spacecraft able to perform in-situ measurements in the high-latitude heliosphere. The out-of-ecliptic phases of Ulysses cover about seventeen years. This makes possible to study heliospheric properties at high latitudes in different solar cycles. In the present investigation we focus on hourly- to daily-scale fluctuations of the polar wind velocity. Though the polar wind is a quite uniform flow, fluctuations in its velocity do not appear negligible. A simple way to characterize wind velocity variations is that of performing a multi-scale statistical analysis of the wind velocity differences. Our analysis is based on the computation of velocity differences at different time lags and the evaluation of statistical quantities (mean, standard deviation, skewness, and kurtosis for the different ensembles. The results clearly show that, though differences exist in the three-dimensional structure of the heliosphere between the investigated solar cycles, the velocity fluctuations in the core of polar coronal holes exhibit essentially unchanged statistical properties.

  8. Concentration fluctuations in gas releases by industrial accidents. Final report

    Nielsen, M.; Chatwin, P.C.; Joergensen, H.E.; Mole, N.; Munro, R.J.; Ott, S.

    2002-05-01

    The COFIN project studied existing remote-sensing Lidar data on concentration fluctuations in atmospheric dispersion from continuous sources at ground level. Fluctuations are described by stochastic models developed by a combination of statistical analyses and surface-layer scaling. The statistical moments and probability density distribution of the fluctuations are most accurately determined in a frame of reference following the instantaneous plume centreline. The spatial distribution of these moments is universal with a gaussian core and exponential tails. The instantaneous plume width is fluctuating with a log-normal distribution. The position of the instantaneous plume centre-line is modelled by a normal distribution and a Langevin equation, by which the meander effect on the time-averaged plume width is predicted. Fixed-frame statistics are modelled by convolution of moving-frame statistics and the probability distribution for the plume centreline. The distance-neighbour function generalized for higher-order statistics has a universal exponential shape. Simulation tools for concentration fluctuations have been developed for either multiple correlated time series or multi-dimensional fields. These tools are based on Karhunen-Loeve expansion and Fourier transformations using iterative or correlation-distortion techniques. The input to the simulation is the probability distribution of the individual processes, assumed stationary, and the cross-correlations of all signal combinations. The use in practical risk assessment is illustrated by implementation of a typical heavy-gas dispersion model, enhanced for prediction and simulation of concentration fluctuations. (au)

  9. Deep Chandra study of the truncated cool core of the Ophiuchus cluster

    Werner, N.; Zhuravleva, I.; Canning, R. E. A.; Allen, S. W.; King, A. L.; Sanders, J. S.; Simionescu, A.; Taylor, G. B.; Morris, R. G.; Fabian, A. C.

    2016-08-01

    We present the results of a deep Chandra observation of the Ophiuchus cluster, the second brightest galaxy cluster in the X-ray sky. The cluster hosts a truncated cool core, with a temperature increasing from kT ˜ 1 keV in the core to kT ˜ 9 keV at r ˜ 30 kpc. Beyond r ˜ 30 kpc, the intracluster medium (ICM) appears remarkably isothermal. The core is dynamically disturbed with multiple sloshing-induced cold fronts, with indications for both Rayleigh-Taylor and Kelvin-Helmholtz instabilities. The residual image reveals a likely subcluster south of the core at the projected distance of r ˜ 280 kpc. The cluster also harbours a likely radio phoenix, a source revived by adiabatic compression by gas motions in the ICM. Even though the Ophiuchus cluster is strongly dynamically active, the amplitude of density fluctuations outside of the cooling core is low, indicating velocities smaller than ˜100 km s-1. The density fluctuations might be damped by thermal conduction in the hot and remarkably isothermal ICM, resulting in our underestimate of gas velocities. We find a surprising, sharp surface brightness discontinuity, that is curved away from the core, at r ˜ 120 kpc to the south-east of the cluster centre. We conclude that this feature is most likely due to gas dynamics associated with a merger. The cooling core lacks any observable X-ray cavities and the active galactic nucleus (AGN) only displays weak, point-like radio emission, lacking lobes or jets. The lack of strong AGN activity may be due to the bulk of the cooling taking place offset from the central supermassive black hole.

  10. Recovery Efficiency Test Project: Phase 1, Activity report. Volume 1: Site selection, drill plan preparation, drilling, logging, and coring operations

    Overbey, W.K. Jr.; Carden, R.S.; Kirr, J.N.

    1987-04-01

    The recovery Efficiency Test well project addressed a number of technical issues. The primary objective was to determine the increased efficiency gas recovery of a long horizontal wellbore over that of a vertical wellbore and, more specifically, what improvements can be expected from inducing multiple hydraulic fractures from such a wellbore. BDM corporation located, planned, and drilled a long radius turn horizontal well in the Devonian shale Lower Huron section in Wayne County, West Virginia, demonstrating that state-of-the-art technology is capable of drilling such wells. BDM successfully tested drilling, coring, and logging in a horizontal well using air as the circulating medium; conducted reservoir modeling studies to protect flow rates and reserves in advance of drilling operations; observed two phase flow conditions in the wellbore not observed previously; cored a fracture zone which produced gas; observed that fractures in the core and the wellbore were not systematically spaced (varied from 5 to 68 feet in different parts of the wellbore); observed that highest gas show rates reported by the mud logger corresponded to zone with lowest fracture spacing (five feet) or high fracture frequency. Four and one-half inch casting was successfully installed in the borehole and was equipped to isolate the horizontal section into eight (8) zones for future testing and stimulation operations. 6 refs., 48 figs., 10 tabs.

  11. Magnetic field activated drug delivery using thermodegradable azo-functionalised PEG-coated core-shell mesoporous silica nanoparticles

    Saint-Cricq, P.; Deshayes, S.; Zink, J. I.; Kasko, A. M.

    2015-07-01

    Core-shell Fe3O4@SiO2 mesoporous silica nanoparticles coated with a new thermodegradable polymer allowed the release of a model drug through heating caused by a high frequency oscillating magnetic field. The thermodegradable polymer was made of poly(ethylene glycol) (PEG) functionalised with azo bonds that break with an elevation of temperature.Core-shell Fe3O4@SiO2 mesoporous silica nanoparticles coated with a new thermodegradable polymer allowed the release of a model drug through heating caused by a high frequency oscillating magnetic field. The thermodegradable polymer was made of poly(ethylene glycol) (PEG) functionalised with azo bonds that break with an elevation of temperature. Electronic supplementary information (ESI) available: Detailed synthesis of the polymers, core-shell nanoparticles and their functionalisation; 1H-NMR spectrum of Azo-PEG GPC, MALDI-TOF, DSC, TGA of the polymers; real time release profile; cell viability assay; release experiment set-up. See DOI: 10.1039/c5nr03777h

  12. Core Muscle Activity during TRX Suspension Exercises with and without Kinesiology Taping in Adults with Chronic Low Back Pain: Implications for Rehabilitation

    Shirley S. M. Fong

    2015-01-01

    Full Text Available This study aimed to examine the effects of kinesiology taping (KT and different TRX suspension workouts on the amplitude of electromyographic (EMG activity in the core muscles among people with chronic low back pain (LBP. Each participant (total n=21 was exposed to two KT conditions: no taping and taping, while performing four TRX suspension exercises: (1 hamstring curl, (2 hip abduction in plank, (3 chest press, and (4 45-degree row. Right transversus abdominis/internal oblique (TrAIO, rectus abdominis (RA, external oblique (EO, and superficial lumbar multifidus (LMF activity was recorded with surface EMG and expressed as a percentage of the EMG amplitude recorded during a maximal voluntary isometric contraction of the respective muscles. Hip abduction in plank increased TrAIO, RA, and LMF EMG amplitude compared with other TRX positions (P0.05. Hip abduction in plank most effectively activated abdominal muscles, whereas the hamstring curl most effectively activated the paraspinal muscles. Applying KT conferred no immediate benefits in improving the core muscle activation during TRX training in adults with chronic LBP.

  13. Understanding experimentally-observed fluctuations

    Kitazawa, Masakiyo

    2016-01-01

    We discuss two topics on the experimental measurements of fluctuation observables in relativistic heavy-ion collisions. First, we discuss the effects of the thermal blurring, i.e. the blurring effect arising from the experimental measurement of fluctuations in momentum space as a proxy of the thermal fluctuations defined in coordinate space, on higher order cumulants. Second, we discuss the effect of imperfect efficiency of detectors on the measurement of higher order cumulants. We derive effective formulas which can carry out the correction of this effect for higher order cumulants based on the binomial model.

  14. Mesoscopic Fluctuations in Stochastic Spacetime

    Shiokawa, K

    2000-01-01

    Mesoscopic effects associated with wave propagation in spacetime with metric stochasticity are studied. We show that the scalar and spinor waves in a stochastic spacetime behave similarly to the electrons in a disordered system. Viewing this as the quantum transport problem, mesoscopic fluctuations in such a spacetime are discussed. The conductance and its fluctuations are expressed in terms of a nonlinear sigma model in the closed time path formalism. We show that the conductance fluctuations are universal, independent of the volume of the stochastic region and the amount of stochasticity.

  15. Enhanced Photocatalytic Activity of CdS-Decorated TiO2/Carbon Core-Shell Microspheres Derived from Microcrystalline Cellulose

    Xin Liu

    2016-03-01

    Full Text Available The fabrication of reusable and biodegradation materials from renewable resources such as cellulose is essential for a sustainable world. The core-shell structured CdS-decorated TiO2/Carbon microspheres (CdS/TiO2/Carbon MS photocatalyst was synthesized with controlled hydrolysis and a novel sonochemical method. It was prepared by using crosslinked microcrystalline cellulose as the core, tetrabutyl titanate as the titania source and CdS as the photosensitizer. The morphology, chemical structure and properties of the obtained material were characterized by many means. Additionally, the photocatalytic activity of the CdS/TiO2/Carbon MS was evaluated by the photodegradation efficiency of Rhodamine B solution, which reached 95.24% under visible light irradiation. This study demonstrated the excellent photocatalytic performance of CdS/TiO2/Carbon MS, which might have promising applications in environmental treatments.

  16. Statistical physics approaches to understanding physiological fluctuations

    Hu, Kun

    This dissertation investigates the influences of the circadian pacemaker on the temporal structures of fluctuations in the human heartbeat and other related physiological signals. The scale-invariant properties of these physiological fluctuations are demonstrated to possess significant circadian rhythms. These findings are relevant in understanding the daily patterns of adverse cardiac events reported by epidemiological studies. Part I of this dissertation introduces the daily pattern in the onset of adverse cardiac events, the circadian pacemaker, and experimental methods of assessing the circadian influences. This part also reviews scale-invariant properties of physiological fluctuations, and scaling analyses that are used to access long-range correlations (an important scale-invariant property). Part II focuses on the effects of trends and nonstationarities---the mean value, standard deviation, and correlation function of signals are not invariant over time. In the case that trends and nonstationarities are unrelated to the underlying mechanism of a signal, simulations and analytic derivations are conducted to explore how to quantify accurately the correlations embedded in the noisy signals that have trends and nonstationarities. Part III investigates dynamics of human motor activity---a physiological function highly correlated with cardiac dynamics. Results demonstrate that apparently random forearm motion possesses previously unrecognized dynamic patterns. These are characterized by similar distribution forms, long-range correlations, and nonlinear Fourier phase interactions across separate individuals and measurements. Part IV reports circadian influences on the dynamic properties of heartbeat fluctuations and activity signals. Correlation properties of heartbeat fluctuations are found to exhibit a significant circadian rhythm that is independent of behavior-related factors including sleep/wake cycles, and random or scheduled events. This circadian rhythm is

  17. Decoherence induced by fluctuating boundaries

    De Lorenci, V A

    2012-01-01

    The effects of fluctuating boundaries on a superposition state of a quantum particle in a box is studied. We consider a model in one space dimension in which the initial state is a coherent superposition of two energy eigenstates. The locations of the walls of the box are assumed to undergo small fluctuation with a Gaussian probability distribution. The spatial probability density of the particle contains an interference term, which is found to decay in time due to the boundary fluctuations. At late times, this term vanishes and the quantum coherence is lost. The system is now described by a density matrix rather than a pure quantum state.This model gives a simple illustration of how environment-induced decoherence can take place in quantum systems. It can also serve as an analog model for the effects of spacetime geometry fluctuations on quantum systems.

  18. Gaussian fluctuations in chaotic eigenstates

    Srednicki, M A; Srednicki, Mark; Stiernelof, Frank

    1996-01-01

    We study the fluctuations that are predicted in the autocorrelation function of an energy eigenstate of a chaotic, two-dimensional billiard by the conjecture (due to Berry) that the eigenfunction is a gaussian random variable. We find an explicit formula for the root-mean-square amplitude of the expected fluctuations in the autocorrelation function. These fluctuations turn out to be O(\\hbar^{1/2}) in the small \\hbar (high energy) limit. For comparison, any corrections due to scars from isolated periodic orbits would also be O(\\hbar^{1/2}). The fluctuations take on a particularly simple form if the autocorrelation function is averaged over the direction of the separation vector. We compare our various predictions with recent numerical computations of Li and Robnik for the Robnik billiard, and find good agreement. We indicate how our results generalize to higher dimensions.

  19. How to observe fluctuating temperature?

    Utyuzh, O V; Wlodarczyk, Z

    2001-01-01

    We provide arguments that event-by-event (EBE) analysis of multiparticle production data are ideal place to search for the possible fluctuation of temperature characterizing hadronizing source in thermodynamical approach.

  20. Fluctuations and Instability in Sedimentation

    Guazzelli, Élisabeth

    2011-01-21

    This review concentrates on the fluctuations of the velocities of sedimenting spheres, and on the structural instability of a suspension of settling fibers. For many years, theoretical estimates and numerical simulations predicted the fluctuations of the velocities of spheres to increase with the size of the container, whereas experiments found no such variation. Two ideas have increased our understanding. First, the correlation length of the velocity fluctuations was found experimentally to be 20 interparticle separations. Second, in dilute suspensions, a vertical variation in the concentration due to the spreading of the front with the clear fluid can inhibit the velocity fluctuations. In a very dilute regime, a homogeneous suspension of fibers suffers a spontaneous instability in which fast descending fiber-rich columns are separated by rising fiber-sparse columns. In a semidilute regime, the settling is hindered, more so than for spheres. © 2011 by Annual Reviews. All rights reserved.

  1. Posttranslational modification of E-cadherin by core fucosylation regulates Src activation and induces epithelial-mesenchymal transition-like process in lung cancer cells.

    Shao, Kang; Chen, Zhong Yi; Gautam, Suraj; Deng, Nian Hui; Zhou, You; Wu, Xing Zhong

    2016-02-01

    E-cadherin is often dysregulated in aggressive lung cancer, the mechanism of which cannot always be explained at the level of transcription. In 66 patients with lung cancer, immunohistochemical staining demonstrated that co-localization of E-cadherin and core fucose by Lens culinaris agglutinin was significantly less extensive in tumor than in nontumor tissue. Through gain and loss of fucosylation experiments in the giant lung carcinoma cell lines 95C and 95D, our results revealed that E-cadherin core fucosylation in 95C cells overexpressing α-1, 6-fucosyltransferase (Fut8) inhibited Fut8-95C cell migration, whereas knockdown of Fut8 in 95D cells enhanced migration of short-interfering RNA-targeting Fut8 (siFut8)-95D cells. The level of active Src (phosphorylated Src [Y416]) was significantly reduced in Fut8-95C cells, but elevated in siFut8-95D cells. In protein complexes immunoprecipitated from Fut8-95C cell lysates with anti-E-cadherin, less phosphorylated Src (Y416) and more β-catenin were observed, but immunoprecipitates from siFut8-95D cells, containing less core fucosylated E-cadherin, contained an elevated level of phospho-Src Y416. In Fut8-95C cells, phosphorylation of Akt (Y315, Y326) and GSK-3β (S9) was significantly reduced, but β-catenin (S37) phosphorylation was enhanced. Expression of N-cadherin and Snail1 was also reduced in Fut8-95C cells, but significantly increased in siFut8-95D cells. Intriguingly, when Src kinase activity was inhibited by treatment of cells with PP2 and SU6656, regulation of N-cadherin, Snail1 and cell migration by E-cadherin core fucosylation was abrogated in both Fut8-95C and siFut8-95D cells. Therefore, posttranslational modification of E-cadherin by less core fucosylation recruited and activated Src, and induced an epithelial-mesenchymal transition-like process in lung cancer cells.

  2. Principle of minimal work fluctuations.

    Xiao, Gaoyang; Gong, Jiangbin

    2015-08-01

    Understanding and manipulating work fluctuations in microscale and nanoscale systems are of both fundamental and practical interest. For example, in considering the Jarzynski equality 〈e-βW〉=e-βΔF, a change in the fluctuations of e-βW may impact how rapidly the statistical average of e-βW converges towards the theoretical value e-βΔF, where W is the work, β is the inverse temperature, and ΔF is the free energy difference between two equilibrium states. Motivated by our previous study aiming at the suppression of work fluctuations, here we obtain a principle of minimal work fluctuations. In brief, adiabatic processes as treated in quantum and classical adiabatic theorems yield the minimal fluctuations in e-βW. In the quantum domain, if a system initially prepared at thermal equilibrium is subjected to a work protocol but isolated from a bath during the time evolution, then a quantum adiabatic process without energy level crossing (or an assisted adiabatic process reaching the same final states as in a conventional adiabatic process) yields the minimal fluctuations in e-βW, where W is the quantum work defined by two energy measurements at the beginning and at the end of the process. In the classical domain where the classical work protocol is realizable by an adiabatic process, then the classical adiabatic process also yields the minimal fluctuations in e-βW. Numerical experiments based on a Landau-Zener process confirm our theory in the quantum domain, and our theory in the classical domain explains our previous numerical findings regarding the suppression of classical work fluctuations [G. Y. Xiao and J. B. Gong, Phys. Rev. E 90, 052132 (2014)].

  3. Atmospheric Methane in Ice Cores

    2005-01-01

    The reconstruction of air trapped in ice cores provides us the most direct information about atmospheric CH4 variations in the past history. Ice core records from the "Three Poles (Antarctica, Greenland and Tibetan Plateau)" reveal the detailed fluctuations of atmospheric CH4 concentration with time and are allowed to quantify the CH4 differences among latitudes. These data are indispensably in the farther study of the relationship between greenhouse gases and climatic change, and of the past changes in terrestrial CH4 emissions. Ice cores reconstruction indicates that atmospheric CH4 concentration has increased quickly since industrialization, and the present day's level of atmospheric CH4 (1800 ppbv) is unprecedented during the past Glacial-Interglacial climate cycles.

  4. Fluctuations in classical sum rules.

    Elton, John R; Lakshminarayan, Arul; Tomsovic, Steven

    2010-10-01

    Classical sum rules arise in a wide variety of physical contexts. Asymptotic expressions have been derived for many of these sum rules in the limit of long orbital period (or large action). Although sum-rule convergence may well be exponentially rapid for chaotic systems in a global phase-space sense with time, individual contributions to the sums may fluctuate with a width which diverges in time. Our interest is in the global convergence of sum rules as well as their local fluctuations. It turns out that a simple version of a lazy baker map gives an ideal system in which classical sum rules, their corrections, and their fluctuations can be worked out analytically. This is worked out in detail for the Hannay-Ozorio sum rule. In this particular case the rate of convergence of the sum rule is found to be governed by the Pollicott-Ruelle resonances, and both local and global boundaries for which the sum rule may converge are given. In addition, the width of the fluctuations is considered and worked out analytically, and it is shown to have an interesting dependence on the location of the region over which the sum rule is applied. It is also found that as the region of application is decreased in size the fluctuations grow. This suggests a way of controlling the length scale of the fluctuations by considering a time dependent phase-space volume, which for the lazy baker map decreases exponentially rapidly with time.

  5. Palladium nanoparticles encapsulated in core-shell silica: A structured hydrogenation catalyst with enhanced activity for reduction of oxyanion water pollutants

    Wang, Yin

    2014-10-03

    Noble metal nanoparticles have been applied to mediate catalytic removal of toxic oxyanions and halogenated hydrocarbons in contaminated water using H2 as a clean and sustainable reductant. However, activity loss by nanoparticle aggregation and difficulty of nanoparticle recovery are two major challenges to widespread technology adoption. Herein, we report the synthesis of a core-shell-structured catalyst with encapsulated Pd nanoparticles and its enhanced catalytic activity in reduction of bromate (BrO3-), a regulated carcinogenic oxyanion produced during drinking water disinfection process, using 1 atm H2 at room temperature. The catalyst material consists of a nonporous silica core decorated with preformed octahedral Pd nanoparticles that were further encapsulated within an ordered mesoporous silica shell (i.e., SiO2@Pd@mSiO2). Well-defined mesopores (2.3 nm) provide a physical barrier to prevent Pd nanoparticle (6 nm) movement, aggregation, and detachment from the support into water. Compared to freely suspended Pd nanoparticles and SiO2@Pd, encapsulation in the mesoporous silica shell significantly enhanced Pd catalytic activity (by a factor of 10) under circumneutral pH conditions that are most relevant to water purification applications. Mechanistic investigation of material surface properties combined with Langmuir-Hinshelwood modeling of kinetic data suggest that mesoporous silica shell enhances activity by promoting BrO3- adsorption near the Pd active sites. The dual function of the mesoporous shell, enhancing Pd catalyst activity and preventing aggregation of active nanoparticles, suggests a promising general strategy of using metal nanoparticle catalysts for water purification and related aqueous-phase applications.

  6. The vasomotor component of the orienting response in man related to spontaneous fluctuation of vasomotor activity in the acral skin zone.

    Kellerová, E; Ruttkay-Nedecký, I

    1978-10-01

    A plethymographic study of the effect of a weak indifferent light or sound stimulus and of a physically identical light stimulus with signal meaning on vasomotor activity in the acral skin zone of man has shown that during stimulus presentation there was a significant rise in the percent of occurrence of vasmotor waves corresponding to the criteria for the vasomotor orienting response (VOR). VOR is elicited significantly more often by stimuli with signal meaning than by physically identical indifferent stimuli. After the acute extinction or VOR disinhibition followed in all cases, and after 40--60 repeated stimuli the occurrence of VOR was still significant. Repeated stimuli had a significant effect on the course of the plethysmographic curve, especially on the component of waves of third order, changing the frequency spectrum and time contingency of waves.

  7. Energetic activity in a star-forming molecular cloud core - A disk constrained bipolar outflow in NGC 2071

    Bally, J.

    1982-10-01

    The discovery of an extended, high-velocity molecular outflow associated with the IR sources in NGC 2071 is reported. High-velocity CO emission from this star-forming molecular cloud core can be traced over a region 4 arcmin in diameter and detected over a velocity range of 70 km/sec. The flow is bipolar; the blueshifted CO emission is displaced to the northeast, while the redshifted emission is displaced to the southwest. Observations in the 98 GHz transition of CS reveal a ridge of dense gas oriented orthogonal to the high-velocity flow axis. A systematic velocity gradient seen in the CS line core suggests that the ridge is a dense, rotating disk centered on the IR source. The disk may be responsible for collimating a spherically symmetric wind originating near the IR source into the bipolar flow observed in the high-velocity CO line wings. The high-velocity CO line wings are modeled as beam diluted emission from clumps or filaments with C-12O optical depths close to unity and a small filling factor. The clumps may be either objects ejected from the vicinity of the central infrared source or shocked gas at the front where a higher velocity but invisible flow encounters ambient cloud material.

  8. Multicomponent (Ce, Cu, Ni) oxides with cage and core-shell structures: tunable fabrication and enhanced CO oxidation activity

    Liu, Wei; Tang, Ke; Lin, Ming; June, Lay Ting Ong; Bai, Shi-Qiang; Young, David James; Li, Xu; Yang, Yan-Zhao; Hor, T. S. Andy

    2016-05-01

    Solvothermal synthesis of Cu2O cubes from Cu(OAc)2 in ethanol provided templates for tunable formation of novel multicomponent composites: hollow CeO2-Cu2O (1), core-shell NiO@Cu2O (2) and hollow CeO2-NiO-Cu2O (3). Composites 1-3 catalyze the oxidation of CO at a lower temperature than the parent Cu2O cubes.Solvothermal synthesis of Cu2O cubes from Cu(OAc)2 in ethanol provided templates for tunable formation of novel multicomponent composites: hollow CeO2-Cu2O (1), core-shell NiO@Cu2O (2) and hollow CeO2-NiO-Cu2O (3). Composites 1-3 catalyze the oxidation of CO at a lower temperature than the parent Cu2O cubes. Electronic supplementary information (ESI) available: Experimental section: materials and characterization; synthesis of materials; catalytic test. Tables S1-S3 and Fig. S1-S8. See DOI: 10.1039/c6nr02383e

  9. Recurrent mutations, including NPM1c, activate a BRD4-dependent core transcriptional program in acute myeloid leukemia.

    Dawson, M A; Gudgin, E J; Horton, S J; Giotopoulos, G; Meduri, E; Robson, S; Cannizzaro, E; Osaki, H; Wiese, M; Putwain, S; Fong, C Y; Grove, C; Craig, J; Dittmann, A; Lugo, D; Jeffrey, P; Drewes, G; Lee, K; Bullinger, L; Prinjha, R K; Kouzarides, T; Vassiliou, G S; Huntly, B J P

    2014-02-01

    Recent evidence suggests that inhibition of bromodomain and extra-terminal (BET) epigenetic readers may have clinical utility against acute myeloid leukemia (AML). Here we validate this hypothesis, demonstrating the efficacy of the BET inhibitor I-BET151 across a variety of AML subtypes driven by disparate mutations. We demonstrate that a common 'core' transcriptional program, which is HOX gene independent, is downregulated in AML and underlies sensitivity to I-BET treatment. This program is enriched for genes that contain 'super-enhancers', recently described regulatory elements postulated to control key oncogenic driver genes. Moreover, our program can independently classify AML patients into distinct cytogenetic and molecular subgroups, suggesting that it contains biomarkers of sensitivity and response. We focus AML with mutations of the Nucleophosmin gene (NPM1) and show evidence to suggest that wild-type NPM1 has an inhibitory influence on BRD4 that is relieved upon NPM1c mutation and cytosplasmic dislocation. This leads to the upregulation of the core transcriptional program facilitating leukemia development. This program is abrogated by I-BET therapy and by nuclear restoration of NPM1. Finally, we demonstrate the efficacy of I-BET151 in a unique murine model and in primary patient samples of NPM1c AML. Taken together, our data support the use of BET inhibitors in clinical trials in AML.

  10. High Photocatalytic Activity of Fe3O4-SiO2-TiO2 Functional Particles with Core-Shell Structure

    Chenyang Xue

    2013-01-01

    Full Text Available This paper describes a novel method of synthesizing Fe3O4-SiO2-TiO2 functional nanoparticles with the core-shell structure. The Fe3O4 cores which were mainly superparamagnetic were synthesized through a novel carbon reduction method. The Fe3O4 cores were then modified with SiO2 and finally encapsulated with TiO2 by the sol-gel method. The results of characterizations showed that the encapsulated 700 nm Fe3O4-SiO2-TiO2 particles have a relatively uniform size distribution, an anatase TiO2 shell, and suitable magnetic properties for allowing collection in a magnetic field. These magnetic properties, large area, relative high saturation intensity, and low retentive magnetism make the particles have high dispersibility in suspension and yet enable them to be recovered well using magnetic fields. The functionality of these particles was tested by measuring the photocatalytic activity of the decolouring of methyl orange (MO and methylene blue (MB under ultraviolet light and sunlight. The results showed that the introduction of the Fe3O4-SiO2-TiO2 functional nanoparticles significantly increased the decoloration rate so that an MO solution at a concentration of 10 mg/L could be decoloured completely within 180 minutes. The particles were recovered after utilization, washing, and drying and the primary recovery ratio was 87.5%.

  11. Fluctuation effects in bidirectional cargo transport

    Klein, Sarah; Santen, Ludger

    2014-01-01

    We discuss a theoretical model for bidirectional cargo transport in biological cells, which is driven by teams of molecular motors and subject to thermal fluctuations. The model describes explicitly the directed motion of the molecular motors on the filament. The motor-cargo coupling is implemented via linear springs. By means of extensive Monte Carlo simulations we show that the model describes the experimentally observed regimes of anomalous diffusion, i.e. subdiffusive behavior at short times followed by superdiffusion at intermediate times. The model results indicate that subdiffuse regime is induced by thermal fluctuations while the superdiffusive motion is generated by correlations of the motors' activity. We also tested the efficiency of bidirectional cargo transport in crowded areas by measuring its ability to pass barriers with increased viscosity. Our results show a remarkable gain of efficiency for high viscosities.

  12. Core-Shell Structural CdS@SnO₂ Nanorods with Excellent Visible-Light Photocatalytic Activity for the Selective Oxidation of Benzyl Alcohol to Benzaldehyde.

    Liu, Ya; Zhang, Ping; Tian, Baozhu; Zhang, Jinlong

    2015-07-01

    Core-shell structural CdS@SnO2 nanorods (NRs) were fabricated by synthesizing SnO2 nanoparticles with a solvent-assisted interfacial reaction and further anchoring them on the surface of CdS NRs under ultrasonic stirring. The morphology, composition, and microstructures of the obtained samples were characterized by field-emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and nitrogen adsorption-desorption. It was found that SnO2 nanoparticles can be tightly anchored on the surface of CdS NRs, and the thickness of SnO2 shells can be conveniently adjusted by simply changing the addition amount of SnO2 quantum dots. UV-vis diffuse reflectance spectrum indicated that SnO2 shell layer also can enhance the visible light absorption of CdS NRs to a certain extent. The results of transient photocurrents and photoluminescence spectra revealed that the core-shell structure can effectively promote the separation rate of electron-hole pairs and prolong the lifetime of electrons. Compared with the single CdS NRs, the core-shell structural CdS@SnO2 exhibited a remarkably enhanced photocatalytic activity for selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) under visible light irradiation, attributed to the more efficient separation of electrons and holes, improved surface area, and enhanced visible light absorption of core-shell structure. The radical scavenging experiments proved that in acetonitrile solution, ·O2- and holes are the main reactive species responsible for BA to BAD transformation, and the lack of ·OH radicals is favorable to obtaining high reaction selectivity.

  13. Outcomes of polio eradication activities in Uttar Pradesh, India: the Social Mobilization Network (SM Net and Core Group Polio Project (CGPP

    Singh Vibha

    2011-05-01

    Full Text Available Abstract Background The primary strategy to interrupt transmission of wild poliovirus in India is to improve supplemental immunization activities and routine immunization coverage in priority districts with a focus on 107 high-risk blocks of western Uttar Pradesh and central Bihar. Villages or urban areas with a history of wild poliovirus transmission, or hard-to-reach or resistant populations are categorized as high-risk areas within blocks. The Social Mobilization Network (SM Net was formed in Uttar Pradesh in 2003 to support polio eradication efforts through improved planning, implementation and monitoring of social mobilization activities in those high-risk areas. In this paper, we examine the vaccination outcomes in districts of SM Net where the CORE Group works. Methods We carried out a secondary data analysis of routine monitoring information collected by the SM Net and the Government of India. These data include information about vaccination outcomes in SM Net areas and non-SM Net areas within the districts where the CORE Group operates. Statistical analysis was used to compare, between SM Net and non-SM Net areas, vaccination outcomes considered sensitive to social mobilization efforts of the SM Net. We employed Generalized Estimating Equations (GEE statistical method to account for Intra-cluster Correlation (ICC, and used 'Quasi-likelihood under the independence model criterion (QIC' as the model selection method. Results Vaccination outcomes in SM Net areas were as high as or higher than in non-SM Net areas. There was considerable variation in vaccination outcomes between districts. Conclusions While not conclusive, the results suggest that the social mobilization efforts of the SM Net and the CORE Group are helping to increase vaccination levels in high-risk areas of Uttar Pradesh. Vaccination outcomes in CORE Group areas were equal or higher than in non-CORE, non-SM Net areas. This occurred even though SM Net areas are those with

  14. Linking Nitrogen-Cycling Microbial Communities to Environmental Fluctuations and Biogeochemical Activity in a Large, Urban Estuary: the San Francisco Bay-Delta

    Francis, C.

    2015-12-01

    Nitrogen (N) availability is an important factor controlling productivity and thus carbon cycling in estuaries. The fate of N in estuaries depends on the activities of the microbes that carry out the N-cycle, which in turn depend on factors such as organic matter availability, dissolved inorganic N, salinity, oxygen, and temperature. Key microbial N transformations include nitrification (the aerobic oxidation of ammonia to nitrite and nitrate) and denitrification (the anaerobic reduction of nitrate to dinitrogen gas). While denitrification leads to N loss, nitrification is the only link between reduced N (produced by decomposition) and oxidized N (substrates for N loss processes), and both processes are known to produce nitrous oxide (N2O), a potent greenhouse gas. Understanding controls of N-cycling in the San Francisco Bay-Delta (SFBD)—the largest estuary on the west coast of North America—is particularly important, as this urban estuary is massively polluted with N, even compared to classic "eutrophic" systems. Interestingly, the SFBD has been spared the detrimental consequences of nutrient enrichment, largely due to high suspended sediment concentrations (and thus low light penetration) throughout the water column, combined with high grazing pressure. However, the recent "clearing" of SFBD waters due to a sharp decrease in suspended sediments may significantly alter the ecology of the estuary, by increasing phytoplankton growth. Thus, the SFBD may be losing its historical resilience to eutrophication, and may soon be "high-nutrient, low-chlorophyll" no more. Elucidating the environmental factors affecting the community structure, activity, and functioning of N-cycling microbes in SFBD is crucial for determining how changes in turbidity and productivity will be propagated throughout the ecosystem. While substantial ecological research in the SFBD has focused on phytoplankton and food webs, bacterial and archaeal communities have received far less attention

  15. Facile Synthesis of Core/Shell-like NiCo2O4-Decorated MWCNTs and its Excellent Electrocatalytic Activity for Methanol Oxidation

    Ko, Tae-Hoon; Devarayan, Kesavan; Seo, Min-Kang; Kim, Hak-Yong; Kim, Byoung-Suhk

    2016-02-01

    The design and development of an economic and highly active non-precious electrocatalyst for methanol electrooxidation is challenging due to expensiveness of the precursors as well as processes and non-ecofriendliness. In this study, a facile preparation of core-shell-like NiCo2O4 decorated MWCNTs based on a dry synthesis technique was proposed. The synthesized NiCo2O4/MWCNTs were characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and selected area energy dispersive spectrum. The bimetal oxide nanoparticles with an average size of 6 ± 2 nm were homogeneously distributed onto the surface of the MWCNTs to form a core-shell-like nanostructure. The NiCo2O4/MWCNTs exhibited excellent electrocatalytic activity for the oxidation of methanol in an alkaline solution. The NiCo2O4/MWCNTs exhibited remarkably higher current density of 327 mA/cm2 and a lower onset potential of 0.128 V in 1.0 M KOH with as high as 5.0 M methanol. The impressive electrocatalytic activity of the NiCo2O4/MWCNTs is promising for development of direct methanol fuel cell based on non-Pt catalysts.

  16. Synthesis, antioxidant and antimicrobial activity of novel vanillin derived piperidin-4-one oxime esters: preponderant role of the phenyl ester substituents on the piperidin-4-one oxime core.

    Harini, Salakatte Thammaiah; Kumar, Honnaiah Vijay; Rangaswamy, Javarappa; Naik, Nagaraja

    2012-12-15

    The study has been achieved the efficient synthesis of vanillin derived piperidin-4-one oxime esters (5a-m) via four step reaction involved Mannich reaction of vanillin, acetone and ammonium acetate to obtain 2,6-bis(4-hydroxy-3-methoxyphenyl)-piperidin-4-one 2 followed by N-methylation and oximation. Further, to enhance the biological activity of vanillin derived piperidin-4-one oxime core, esterification of 4 with substituted benzoyl chlorides in the presence of strong organic base t-BuOK accomplished a series of vanillin derived piperidin-4-one oxime esters (5a-m). The synthesized analogues are screened for their antioxidant and antimicrobial studies and the preponderant effect of the phenyl ester substituents on the biological activity of piperidin-4-one oxime core was demonstrated. Among the tested compounds, 5i and 5j are emerged as outperformed antioxidants than standard Butylated hydroxy anisole (BHA) whereas, compounds 5b and 5d manifested potent antibacterial and antifungal activity than standard streptomycin and fluconazole respectively.

  17. Facile Synthesis of Core/Shell-like NiCo2O4-Decorated MWCNTs and its Excellent Electrocatalytic Activity for Methanol Oxidation

    Tae-Hoon Ko; Kesavan Devarayan; Min-Kang Seo; Hak-Yong Kim; Byoung-Suhk Kim

    2016-01-01

    The design and development of an economic and highly active non-precious electrocatalyst for methanol electrooxidation is challenging due to expensiveness of the precursors as well as processes and non-ecofriendliness. In this study, a facile preparation of core-shell-like NiCo2O4 decorated MWCNTs based on a dry synthesis technique was proposed. The synthesized NiCo2O4/MWCNTs were characterized by infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray dif...

  18. The commitment of Indra with the innovation as core of its activities; El compromiso de INDRA con la innovacion como clave de actividad de la empresa

    Martin de castro, G.; Lopez Saez, P.; Murcia Rivera, C.

    2007-07-01

    This paper shows the commitment of Indra, a Spanish firm which holds a position of outstanding leader in information technologies, with the innovation, that becomes the core of its activities, and which leads it into the collaboration with the University in R and D transfer processes. Indra is the biggest Spanish in the information technologies arena. It has 19.500 employees and a clear leadership in its market. In order to illustrate how it takes part in the R and D transfer processes, two specific cases of collaboration with Universidad Autonoma de Madrid (UAM) and Universidad Politecnica de Madrid (UPM) are provided. (Author) 6 refs.

  19. Activity of Maly Aktru Glacier (Сentral Altai and changes tree line fluctuations in its basin for a historical period

    A. N. Nazarov

    2016-01-01

    Full Text Available Major problems of dating of the glaciers activity from the wood residues found in moraines are discussed by the example of Maly Aktru Glacier. First of all, these are the underestimation of the glacier development features, the age of the sample itself and its content as well as losses of some outer rings. The study proves that disagreements between dendrochronological and radiocarbon ages of the samples are caused by manifestation of the Suess effect and contents of the wood cells. The reconstruction of June–July temperatures in the Aktru valley for two thousand years was used to reconstruct the altitudinal variability of the tree line thermal potential. Existence of a climatic optimum (I–IV A.D. had been revealed that brought to the higher position of the tree line in mid ages than its thermal potential could enable. On the basis of variability of growth indices for Siberian larch, it is shown that the medieval optimum stands out against a background of solely strong temperature depressions separating it from ancient and modern times, and the climate’s natural history is evidence that the current climate warming is an ordinary phenomenon.

  20. Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

    Hannibal, Jens; Hsiung, Hansen M; Fahrenkrug, Jan

    2011-01-01

    to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral...

  1. Oxygen-evolving Activity in Photosystem Ⅱ Core Complex of Photosynthetic Membrane in the Presence of Native Lipid

    YANG,Zhen-Le(阳振乐); WANG,Ze-Neng(王则能); LI,Liang-Bi(李良璧); KUANG,Ting-Yun(匡廷云)

    2002-01-01

    The techniques of oxygen electrode polarography and Fourier transform infrared (FT-IR) spectroscopy were employed to explore the involvement of digalactosyl diacylglycerol (DGDG) in functional and structural roles in the photosysten Ⅱ core com-plex (PSⅡCC). It was shown that DGDG exhibited the ability to stimulate the oxygen evolution in PSⅡCC, which was accompanied by the changes in the strucctures of PSⅡCC proteins.Tne results revealed that there existed hydrogen-bonding interactions between DGDG molecules and PSⅡCC proteins. It is most likely that the sites of PSⅡCC interaction with DGDG are in the extrinsic protein of 33 kDa.

  2. Historical Associations of Molecular Measurements of Escherichia coli and Enterococci to Anthropogenic Activities and Climate Variables in Freshwater Sediment Cores.

    Brooks, Yolanda M; Baustian, Melissa M; Baskaran, Mark; Ostrom, Nathaniel E; Rose, Joan B

    2016-07-05

    This study investigated the long-term associations of anthropogenic (sedimentary P, C, and N concentrations, and human population in the watershed), and climatic variables (air temperature, and river discharge) with Escherichia coli uidA and enterococci 23S rRNA concentrations in sediment cores from Anchor Bay (AB) in Lake St. Clair, and near the mouth of the Clinton River (CR), Michigan. Calendar year was estimated from vertical abundances of (137)Cs. The AB and CR cores spanned c.1760-2012 and c.1895-2012, respectively. There were steady state concentrations of enterococci in AB during c.1760-c.1860 and c.1910-c.2003 at ∼0.1 × 10(5) and ∼2.0 × 10(5) cell equivalents (CE) per g-dry wt, respectively. Enterococci concentrations in CR increased toward present day, and ranged from ∼0.03 × 10(5) to 9.9 × 10(5) CE/g-dry wt. The E. coli concentrations in CR and AB increased toward present day, and ranged from 0.14 × 10(7) to 1.7 × 10(7) CE/g-dry wt, and 1.8 × 10(6) to 8.5 × 10(6) CE/g-dry wt, respectively. Enterococci was associated with population and river discharge, while E. coli was associated with population, air temperature, and N and C concentrations (p < 0.05). Sediments retain records of the abundance of fecal indicator bacteria, and offer a way to evaluate responses to increased population, nutrient loading, and environmental policies.

  3. From cusps to cores: a stochastic model

    El-Zant, Amr; Combes, Francoise

    2016-01-01

    The cold dark matter model of structure formation faces apparent problems on galactic scales. Several threads point to excessive halo concentration, including central densities that rise too steeply with decreasing radius. Yet, random fluctuations in the gaseous component can 'heat' the centres of haloes, decreasing their densities. We present a theoretical model deriving this effect from first principles: stochastic variations in the gas density are converted into potential fluctuations that act on the dark matter; the associated force correlation function is calculated and the corresponding stochastic equation solved. Assuming a power law spectrum of fluctuations with maximal and minimal cutoff scales, we derive the velocity dispersion imparted to the halo particles and the relevant relaxation time. We further perform numerical simulations, with fluctuations realised as a Gaussian random field, which confirm the formation of a core within a timescale comparable to that derived analytically. Non-radial colle...

  4. Interaction of the transcription start site core region and transcription factor YY1 determine ascorbate transporter SVCT2 exon 1a promoter activity.

    Huan Qiao

    Full Text Available Transcription of the ascorbate transporter, SVCT2, is driven by two distinct promoters in exon 1 of the transporter sequence. The exon 1a promoter lacks a classical transcription start site and little is known about regulation of promoter activity in the transcription start site core (TSSC region. Here we present evidence that the TSSC binds the multifunctional initiator-binding protein YY1. Electrophoresis shift assays using YY1 antibody showed that YY1 is present as one of two major complexes that specifically bind to the TSSC. The other complex contains the transcription factor NF-Y. Mutations in the TSSC that decreased YY1 binding also impaired the exon 1a promoter activity despite the presence of an upstream activating NF-Y/USF complex, suggesting that YY1 is involved in the regulation of the exon 1a transcription. Furthermore, YY1 interaction with NF-Y and/or USF synergistically enhanced the exon 1a promoter activity in transient transfections and co-activator p300 enhanced their synergistic activation. We propose that the TSSC plays a vital role in the exon 1a transcription and that this function is partially carried out by the transcription factor YY1. Moreover, co-activator p300 might be able to synergistically enhance the TSSC function via a "bridge" mechanism with upstream sequences.

  5. Sectoral Shifts and Cyclical Fluctuations Sectoral Shifts and Cyclical Fluctuations

    Richard Rogerson

    1991-03-01

    Full Text Available Sectoral Shifts and Cyclical Fluctuations This paper studies a two sector real business cycle model in which the sectors experience different trend rates of growth and labor mobility is costly. Predictions are derived concerning the correlation between sectoral reallocation of workers and the cycle. This correlation may be positive or negative depending upon whether the growing sector displays larger or smaller fluctuations than the shrinking sector. The post- World War II period has witnessed two major patterns of sectoral change in industrialized countries: movement out of agriculture and movement out of the industrial sector. The model's basic prediction is shown to be consistent with the observed pattern of reallocation.

  6. How supernova feedback turns dark matter cusps into cores

    Pontzen, Andrew; Governato, Fabio

    2012-04-01

    We propose and successfully test against new cosmological simulations a novel analytical description of the physical processes associated with the origin of cored dark matter density profiles. In the simulations, the potential in the central kiloparsec changes on sub-dynamical time-scales over the redshift interval 4 > z > 2, as repeated, energetic feedback generates large underdense bubbles of expanding gas from centrally concentrated bursts of star formation. The model demonstrates how fluctuations in the central potential irreversibly transfer energy into collisionless particles, thus generating a dark matter core. A supply of gas undergoing collapse and rapid expansion is therefore the essential ingredient. The framework, based on a novel impulsive approximation, breaks with the reliance on adiabatic approximations which are inappropriate in the rapidly changing limit. It shows that both outflows and galactic fountains can give rise to cusp flattening, even when only a few per cent of the baryons form stars. Dwarf galaxies maintain their core to the present time. The model suggests that constant density dark matter cores will be generated in systems of a wide mass range if central starbursts or active galactic nucleus phases are sufficiently frequent and energetic.

  7. Fluctuations in complex networks with variable dimensionality and heterogeneity

    Yoo, H.-H.; Lee, D.-S.

    2016-03-01

    Synchronizing individual activities is essential for the stable functioning of diverse complex systems. Understanding the relation between dynamic fluctuations and the connection topology of substrates is therefore important, but it remains restricted to regular lattices. Here we investigate the fluctuation of loads, assigned to the locally least-loaded nodes, in the largest-connected components of heterogeneous networks while varying their link density and degree exponents. The load fluctuation becomes finite when the link density exceeds a finite threshold in weakly heterogeneous substrates, which coincides with the spectral dimension becoming larger than 2 as in the linear diffusion model. The fluctuation, however, diverges also in strongly heterogeneous networks with the spectral dimension larger than 2. This anomalous divergence is shown to be driven by large local fluctuations at hubs and their neighbors, scaling linearly with degree, which can give rise to diverging fluctuations at small-degree nodes. Our analysis framework can be useful for understanding and controlling fluctuations in real-world systems.

  8. An accelerating high-latitude jet in Earth’s core

    W. Livermore, Philip; Hollerbach, Rainer; Finlay, Chris

    2016-01-01

    Observations of the change in Earth’s magnetic field—the secular variation—provide information about the motion of liquid metal within the core that is responsible for the magnetic field’s generation. High-resolution observations from the European Space Agency’s Swarm satellite mission show intense...... field change at high latitude, localized in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we show that this feature can be explained by a localized, non-axisymmetric, westward jet of 420 km width on the tangent cylinder, the cylinder of fluid within the core...... phase may be part of a longer-term fluctuation of the jet causing both eastward and westward movement of magnetic features over historical periods, and may contribute to recent changes in torsional-wave activity and the rotation direction of the inner core....

  9. Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

    Xin Yang

    2014-01-01

    Full Text Available Through a natural tree grain template and sol-gel technology, the heterogeneous catalytic materials based on polyoxometalate compounds H3[PM12O40] encapsulating SiO2: SiO2@H3[PM12O40] (SiO2@PM12, M = W, Mo with core-shell structure had been prepared. The structure and morphology of the core-shell microspheres were characterized by the XRD, IR spectroscopy, UV-Vis absorbance, and SEM. These microsphere materials can be used as heterogeneous catalysts with high activity and stability for catalytic wet air oxidation of pollutant dyes safranine T (ST at room condition. The results show that the catalysts have excellent catalytic activity in treatment of wastewater containing 10 mg/L ST, and 94% of color can be removed within 60 min. Under different cycling runs, it is shown that the catalysts are stable under such operating conditions and the leaching tests show negligible leaching effect owing to the lesser dissolution.

  10. Hydrophobic-core PEGylated graft copolymer-stabilized nanoparticles composed of insoluble non-nucleoside reverse transcriptase inhibitors exhibit strong anti-HIV activity.

    Leporati, Anita; Novikov, Mikhail S; Valuev-Elliston, Vladimir T; Korolev, Sergey P; Khandazhinskaya, Anastasia L; Kochetkov, Sergey N; Gupta, Suresh; Goding, Julian; Bolotin, Elijah; Gottikh, Marina B; Bogdanov, Alexei A

    2016-11-01

    Benzophenone-uracil (BPU) scaffold-derived candidate compounds are efficient non-nucleoside reverse transcriptase inhibitors (NNRTI) with extremely low solubility in water. We proposed to use hydrophobic core (methoxypolyethylene glycol-polylysine) graft copolymer (HC-PGC) technology for stabilizing nanoparticle-based formulations of BPU NNRTI in water. Co-lyophilization of NNRTI/HC-PGC mixtures resulted in dry powders that could be easily reconstituted with the formation of 150-250 nm stable nanoparticles (NP). The NP and HC-PGC were non-toxic in experiments with TZM-bl reporter cells. Nanoparticles containing selected efficient candidate Z107 NNRTI preserved the ability to inhibit HIV-1 reverse transcriptase polymerase activities with no appreciable change of EC50. The formulation with HC-PGC bearing residues of oleic acid resulted in nanoparticles that were nearly identical in anti-HIV-1 potency when compared to Z107 solutions in DMSO (EC50=7.5±3.8 vs. 8.2±5.1 nM). Therefore, hydrophobic core macromolecular stabilizers form nanoparticles with insoluble NNRTI while preserving the antiviral activity of the drug cargo.

  11. Kerr black hole thermodynamical fluctuations

    Pavon, D.; Rubi, J. M.

    1985-04-01

    The near-equilibrium thermodynamical (TD) fluctuations of a massive rotating uncharged Kerr black hole immersed in a uniformly corotating radiation bath at its temperature are investigated theoretically, generalizing Schwarzschild-black-hole analysis of Pavon and Rubi(1983), based on Einstein fluctuation theory. The correlations for the energy and angular moment fluctuations and the second moments of the other TD parameters are obtained, and the generalized second law of black-hole TD and the Bekenstein (1975) interpretation of black-hole entropy are seen as functioning well in this case. A local-stability criterion and relation for TD equilibrium between the Kerr hole and its own radiation in the flat-space-time limit are derived, and a restriction between C and Lambda is deduced.

  12. Spectrum of Wind Power Fluctuations

    Bandi, M. M.

    2017-01-01

    Wind power fluctuations for an individual turbine and plant have been widely reported to follow the Kolmogorov spectrum of atmospheric turbulence; both vary with a fluctuation time scale τ as τ2 /3. Yet, this scaling has not been explained through turbulence theory. Using turbines as probes of turbulence, we show the τ2 /3 scaling results from a large scale influence of atmospheric turbulence. Owing to this long-range influence spanning 100s of kilometers, when power from geographically distributed wind plants is summed into aggregate power at the grid, fluctuations average (geographic smoothing) and their scaling steepens from τ2 /3→τ4 /3, beyond which further smoothing is not possible. Our analysis demonstrates grids have already reached this τ4 /3 spectral limit to geographic smoothing.

  13. Fluctuation scaling in point processes

    Koyama, Shinsuke

    2014-01-01

    Fluctuation scaling has universally been observed in a wide variety of phenomena. For time series describing sequences of events, it can be expressed as power function relationship between the variance and the mean of either the inter-event interval or counting statistics, depending on the measurement variables. In this article, fluctuation scaling for series of events is formulated for the first time, in which the scaling exponents in the inter-event interval and counting statistics are related. It is also shown that a simple mechanism consisting of first-passage time to a threshold for Ornstein-Uhlenbeck processes explains fluctuation scaling with various exponents depending on the subthreshold dynamics. A possible implication of the results is discussed in terms of characterizing `intrinsic' variability of neuronal discharges.

  14. Fluctuation theorems for quantum processes

    Albash, Tameem; Marvian, Milad; Zanardi, Paolo

    2013-01-01

    We present fluctuation theorems and moment generating function equalities for generalized thermodynamic observables and quantum dynamics described by completely positive trace preserving (CPTP) maps, with and without feedback control. Our results include the quantum Jarzynski equality and Crooks fluctuation theorem, and clarify the special role played by the thermodynamic work and thermal equilibrium states in previous studies. We show that unitality replaces micro-reversibility as the condition for the physicality of the reverse process in our fluctuation theorems. We present an experimental application of our theory to the problem of extracting the system-bath coupling magnitude, which we do for a system of pairs of coupled superconducting flux qubits undergoing quantum annealing.

  15. Thermodynamic constraints on fluctuation phenomena

    Maroney, O. J. E.

    2009-12-01

    The relationships among reversible Carnot cycles, the absence of perpetual motion machines, and the existence of a nondecreasing globally unique entropy function form the starting point of many textbook presentations of the foundations of thermodynamics. However, the thermal fluctuation phenomena associated with statistical mechanics has been argued to restrict the domain of validity of this basis of the second law of thermodynamics. Here we demonstrate that fluctuation phenomena can be incorporated into the traditional presentation, extending rather than restricting the domain of validity of the phenomenologically motivated second law. Consistency conditions lead to constraints upon the possible spectrum of thermal fluctuations. In a special case this uniquely selects the Gibbs canonical distribution and more generally incorporates the Tsallis distributions. No particular model of microscopic dynamics need be assumed.

  16. Fluctuations in Relativistic Causal Hydrodynamics

    Kumar, Avdhesh; Mishra, Ananta P

    2013-01-01

    The formalism to calculate the hydrodynamics fluctuation using the quasi-stationary fluctuation theory of Onsager to the relativistic Navier-Stokes hydrodynamics is already known. In this work we calculate hydrodynamic fluctuations in relativistic causal theory of Muller, Israel and Stewart and other related causal hydrodynamic theories. We show that expressions for the Onsager coefficients and the correlation functions have form similar to the ones obtained by using Navier-Stokes equation. However, temporal evolution of the correlation functions obtained using MIS and the other causal theories can be significantly different than the correlation functions obtained using the Navier-Stokes equation. Finally, as an illustrative example, we explicitly plot the correlation functions obtained using the causal-hydrodynamics theories and compare them with correlation functions obtained by earlier authors using the expanding boost-invariant (Bjorken) flows.

  17. Modeling fluctuations in scattered waves

    Jakeman, E

    2006-01-01

    Fluctuations in scattered waves limit the performance of imaging and remote sensing systems that operate on all wavelengths of the electromagnetic spectrum. To better understand these fluctuations, Modeling Fluctuations in Scattered Waves provides a practical guide to the phenomenology, mathematics, and simulation of non-Gaussian noise models and discusses how they can be used to characterize the statistics of scattered waves.Through their discussion of mathematical models, the authors demonstrate the development of new sensing techniques as well as offer intelligent choices that can be made for system analysis. Using experimental results and numerical simulation, the book illustrates the properties and applications of these models. The first two chapters introduce statistical tools and the properties of Gaussian noise, including results on phase statistics. The following chapters describe Gaussian processes and the random walk model, address multiple scattering effects and propagation through an extended med...

  18. The nature of the solar activity during the Maunder Minimum revealed by the Guliya ice core record

    2000-01-01

    Whether the solar activity was very low, and especially whether the solar cycle existed, during the Maunder Minimum (1645-1715 AD), have been disputed for a long time. In this paper we use the Guliya NO3- data, which can reflect the solar activity, to analyze the characteristics of the solar activity during the Maunder Minimum. The results show that the solar activity was indeed low, and solar cycle displayed normal as present, i.e. about 11a, in that period. Moreover, it was found that the solar activity contains a 36-year periodic component probably, which might be related to the variations in the length of the sunspot cycle. This finding is of importance for the study of the relationship between the sun variability and the Earth climate change.

  19. Activation of PKCzeta and PKMzeta in the nucleus accumbens core is necessary for the retrieval, consolidation and reconsolidation of drug memory.

    Jose A Crespo

    Full Text Available One of the greatest challenges in the treatment of substance dependence is to reverse the control that drug-associated stimuli have gained over the addict's behavior, as these drug-associated memories increase the risk of relapse even after long periods of abstinence. We report here that inhibition of the atypical protein kinase C isoform PKCzeta and its constitutively active isoform PKMzeta with the pseudosubstrate inhibitor ZIP administered locally into the nucleus accumbens core reversibly inhibited the retrieval of drug-associated memory and drug (remifentanil seeking, whereas a scrambled ZIP peptide or staurosporine, an effective inhibitor of c/nPKC-, CaMKII-, and PKA kinases that does not affect PKCzeta/PKMzeta activity, was without effect on these memory processes. Acquisition or extinction of drug-associated memory remained unaffected by PKCzeta- and PKMzeta inhibition.

  20. Merits and qualms of work fluctuations in classical fluctuation theorems

    Deng, Jiawen; Tan, Alvis Mazon; Hänggi, Peter; Gong, Jiangbin

    2017-01-01

    Work is one of the most basic notions in statistical mechanics, with work fluctuation theorems being one central topic in nanoscale thermodynamics. With Hamiltonian chaos commonly thought to provide a foundation for classical statistical mechanics, here we present general salient results regarding how (classical) Hamiltonian chaos generically impacts on nonequilibrium work fluctuations. For isolated chaotic systems prepared with a microcanonical distribution, work fluctuations are minimized and vanish altogether in adiabatic work protocols. For isolated chaotic systems prepared at an initial canonical distribution at inverse temperature β , work fluctuations depicted by the variance of e-β W are also minimized by adiabatic work protocols. This general result indicates that, if the variance of e-β W diverges for an adiabatic work protocol, it diverges for all nonadiabatic work protocols sharing the same initial and final Hamiltonians. Such divergence is hence not an isolated event and thus greatly impacts on the efficiency of using Jarzynski's equality to simulate free-energy differences. Theoretical results are illustrated in a Sinai model. Our general insights shall boost studies in nanoscale thermodynamics and are of fundamental importance in designing useful work protocols.

  1. Consistency of detrended fluctuation analysis

    Løvsletten, Ola

    2016-01-01

    The scaling function $F(s)$ in detrended fluctuation analysis (DFA) scales as $F(s)\\sim s^{H}$ for stochastic processes with Hurst exponents $H$. We prove this scaling law for both stationary stochastic processes with $01$. As a final application of the new theory, we present an estimator $\\hat F(s)$ that can handle missing data in regularly sampled time series without the need for interpolation schemes. Under mild regularity conditions, $\\hat F(s)$ is equal in expectation to the fluctuation function $F(s)$ in the gap-free case.

  2. Turbulent fluctuations around Bjorken flow

    Floerchinger, Stefan

    2011-01-01

    We study the evolution of local event-by-event deviations from smooth average fluid dynamic fields, as they can arise in heavy ion collisions from the propagation of fluctuating initial conditions. Local fluctuations around Bjorken flow are found to be governed by non-linear equations whose solutions can be characterized qualitatively in terms of Reynolds numbers. Perturbations at different rapidities decouple quickly, and satisfy (after suitable coordinate transformations) an effectively two-dimensional Navier-Stokes equation of non-relativistic form. We discuss the conditions under which non-linearities in these equations cannot be neglected and turbulent behavior is expected to set in.

  3. The G1613A mutation in the HBV genome affects HBeAg expression and viral replication through altered core promoter activity.

    Man-Shan Li

    Full Text Available Infection of hepatitis B virus (HBV causes acute and chronic hepatitis and is closely associated with the development of cirrhosis and hepatocellular carcinoma (HCC. Previously, we demonstrated that the G1613A mutation in the HBV negative regulatory element (NRE is a hotspot mutation in HCC patients. In this study, we further investigated the functional consequences of this mutation in the context of the full length HBV genome and its replication. We showed that the G1613A mutation significantly suppresses the secretion of e antigen (HBeAg and enhances the synthesis of viral DNA, which is in consistence to our clinical result that the G1613A mutation associates with high viral load in chronic HBV carriers. To further investigate the molecular mechanism of the mutation, we performed the electrophoretic mobility shift assay with the recombinant RFX1 protein, a trans-activator that was shown to interact with the NRE of HBV. Intriguingly, RFX1 binds to the G1613A mutant with higher affinity than the wild-type sequence, indicating that the mutation possesses the trans-activating effect to the core promoter via NRE. The trans-activating effect was further validated by the enhancement of the core promoter activity after overexpression of RFX1 in liver cell line. In summary, our results suggest the functional consequences of the hotspot G1613A mutation found in HBV. We also provide a possible molecular mechanism of this hotspot mutation to the increased viral load of HBV carriers, which increases the risk to HCC.

  4. Development of core design and analysis technology for integral reactor; development of coolant activity and dose evaluation program

    Kang, Chang Sun; Kim, Byeong Soo; Go, Hyun Seok; Lee, Young Wook; Jang, Mee [Seoul National University, Seoul (Korea)

    2002-03-01

    SMART, small- medium-sized integral reactor, is different from the customary electricity-generation PWR in design concepts and structures. The conventional coolant activity evaluation codes used in customary PWRs cannot be applied to SMART. In this study, SAEP(Specific Activity Evaluation Program) is developed that can be applied to both customary PWR and advanced reactor such as SMART. SAEP uses three methods(SAEP Ver.02, Ver.05, Ver.06) to evaluate coolant activity. They solve inhomogeneous linearly-coupled differential equations generated by considering nuclear system as N sub-components. Coolant activities of customary PWR are evaluated by use of SAEP. The results show good agreement with FSAR data. SAEP is used to evaluate coolant activities for SMART and the results are proposed in this study. These results show that SAEP is able to perform coolant activity evaluation for both customary PWR and advanced reactor such as SMART. In addition, with respect to radiation shielding optimization, conventional optimization methods and their characteristics related to radiation shielding are reviewed and analyzed. Strategies for proper usage of conventional methods are proposed to agree with the shielding design cases. 30 refs., 25 figs., 6 tabs. (Author)

  5. An analysis of reverberation fluctuation by mean square derivation

    2010-01-01

    A method for evaluating the fluctuation of the reverberation envelope is proposed and examined through simulation and real data in this paper.This method is different from the coefficient of variation which is only a function of the first and second order moment of the reverberation statistical model.By using the standard variance of the mean square derivate(MSD) of the reverberation envelope,the paper shows that the reverberation fluctuation is a function of the bandwidth of the emitted signal,and that a large value of the square variance means little fluctuation of the reverberation envelope.Theoretical studies show that the standard variance is proportional to the bandwidth of the emitted signal,so we conclude that less time width or larger bandwidth of the transmitted signal produces less fluctuation.Simulation and real active sonar data processing are used to verify this conclusion.

  6. Stronger enhancer II/core promoter activities of hepatitis B virus isolates of B2 subgenotype than those of C2 subgenotype.

    Qin, Yanli; Zhou, Xueshi; Jia, Haodi; Chen, Chaoyang; Zhao, Weifeng; Zhang, Jiming; Tong, Shuping

    2016-07-27

    Hepatitis B virus (HBV) genotype C causes prolonged chronic infection and increased risk for liver cancer than genotype B. Our previous work revealed lower replication capacity of wild-type genotype C2 than B2 isolates. HBV DNA replication is driven by pregenomic RNA, which is controlled by core promoter (CP) and further augmented by enhancer I (ENI) and enhancer II (ENII). DNA fragments covering these regulatory elements were amplified from B2 and C2 isolates to generate luciferase reporter constructs. As ENII is fully embedded in CP, we inserted HBV DNA fragments in the sense orientation to determine their combined activities, and in the antisense orientation to measure enhancer activities alone. Genotype B2 isolates displayed higher ENI+ENII+CP, ENII+CP, and ENII activities, but not ENI or ENI+ENII activity, than C2 isolates. The higher ENII+CP activity was partly attributable to 4 positions displaying genotype-specific variability. Exchanging CP region was sufficient to revert the replication phenotypes of several B2 and C2 clones tested. These results suggest that a weaker ENII and/or CP at least partly accounts for the lower replication capacities of wild-type C2 isolates, which could drive the subsequent acquisition of CP mutations. Such mutations increase genome replication and are implicated in liver cancer development.

  7. Common Core: Victory Is Yours!

    Fink, Jennifer L. W.

    2012-01-01

    In this article, the author discusses how to implement the Common Core State Standards in the classroom. She presents examples and activities that will leave teachers feeling "rosy" about tackling the new standards. She breaks down important benchmarks and shows how other teachers are doing the Core--and loving it!

  8. Firm default and aggregate fluctuations

    Jacobson, Tor; Linde, Jesper; Roszbach, Kasper

    2013-01-01

    This paper studies the relationship between macroeconomic fluctuations and corporate defaults while conditioning on industry affiliation and an extensive set of firm-specific factors. By using a panel data set for virtually all incorporated Swedish businesses over 1990-2009, a period which includes

  9. Fluctuations in Overlapping Generations Economies

    Tvede, Mich

    . The approach to existence of endogenous fluctuations is basic in the sense that the prime ingredients are the implicit function theorem and linear algebra. Moreover the approach is applied to show that for an open and dense set of utility functions there exist endowment vectors such that sunspot equilibria...

  10. Chaotic dynamics, fluctuations, nonequilibrium ensembles.

    Gallavotti, Giovanni

    1998-06-01

    The ideas and the conceptual steps leading from the ergodic hypothesis for equilibrium statistical mechanics to the chaotic hypothesis for equilibrium and nonequilibrium statistical mechanics are illustrated. The fluctuation theorem linear law and universal slope prediction for reversible systems is briefly derived. Applications to fluids are briefly alluded to. (c) 1998 American Institute of Physics.

  11. Voltage fluctuations in neurons: signal or noise?

    Yarom, Yosef; Hounsgaard, Jorn

    2011-01-01

    , we discuss noise-free neuronal signaling and detrimental and beneficial forms of noise in large-scale functional neural networks. Evidence that noise and variability in some cases go hand in hand with behavioral variability and increase behavioral choice, richness, and adaptability opens new avenues...... that allows and facilitates complex adaptive behavior in an unpredictable world. Here we review the growing experimental evidence that functional network activity is associated with intense fluctuations in membrane potential and spike timing. We trace origins and consequences of noise and variability. Finally...

  12. Multi-voxel pattern analysis (MVPA reveals abnormal fMRI activity in both the core and extended face network in congenital prosopagnosia

    Davide eRivolta

    2014-11-01

    Full Text Available The ability to identify faces is mediated by a network of cortical and subcortical brain regions in humans. It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP, a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population. Here, we used functional Magnetic Resonance Imaging (fMRI to measure neural responses to faces, objects, bodies and body-parts in a group of seven CPs and ten healthy control participants. Using multi-voxel pattern analysis (MVPA of the fMRI data we demonstrate that neural activity within the core (i.e., occipital face area and fusiform face area and extended (i.e., anterior temporal cortex face regions in CPs showed reduced discriminability between faces and objects. Reduced differentiation between faces and objects in CP was also seen in the right parahippocampal cortex. In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs. In addition to MVPA analysis, we also ran traditional mass-univariate analysis, which failed to show any group differences in face and object discriminability. In sum, these findings demonstrate (i face-object representations impairments in CP which encompass both the core and extended face regions, and (ii superior power of MVPA in detecting group differences.

  13. Multi-voxel pattern analysis (MVPA) reveals abnormal fMRI activity in both the "core" and "extended" face network in congenital prosopagnosia.

    Rivolta, Davide; Woolgar, Alexandra; Palermo, Romina; Butko, Marina; Schmalzl, Laura; Williams, Mark A

    2014-01-01

    The ability to identify faces is mediated by a network of cortical and subcortical brain regions in humans. It is still a matter of debate which regions represent the functional substrate of congenital prosopagnosia (CP), a condition characterized by a lifelong impairment in face recognition, and affecting around 2.5% of the general population. Here, we used functional Magnetic Resonance Imaging (fMRI) to measure neural responses to faces, objects, bodies, and body-parts in a group of seven CPs and ten healthy control participants. Using multi-voxel pattern analysis (MVPA) of the fMRI data we demonstrate that neural activity within the "core" (i.e., occipital face area and fusiform face area) and "extended" (i.e., anterior temporal cortex) face regions in CPs showed reduced discriminability between faces and objects. Reduced differentiation between faces and objects in CP was also seen in the right parahippocampal cortex. In contrast, discriminability between faces and bodies/body-parts and objects and bodies/body-parts across the ventral visual system was typical in CPs. In addition to MVPA analysis, we also ran traditional mass-univariate analysis, which failed to show any group differences in face and object discriminability. In sum, these findings demonstrate (i) face-object representations impairments in CP which encompass both the "core" and "extended" face regions, and (ii) superior power of MVPA in detecting group differences.

  14. Remote long-term registrations of sleep-wake rhythms, core body temperature and activity in marmoset monkeys

    Hoffmann, Kerstin; Coolen, Alex; Schlumbohm, Christina; Meerlo, Peter; Fuchs, Eberhard

    2012-01-01

    Initial studies in the day active marmoset monkey (Callithrix jacchus) indicate that the sleep-wake cycle of these non-human primates resembles that of humans and therefore conceivably represent an appropriate model for human sleep. The methods currently employed for sleep studies in marmosets are l

  15. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Guo, Longhai; Ren, Shanshan; Qiu, Teng, E-mail: qiuteng@mail.buct.edu.cn; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu, E-mail: lixy@mail.buct.edu.cn [Ministry of Education, Beijing University of Chemical Technology, Key Laboratory of Carbon Fiber and Functional Polymer (China)

    2015-01-15

    We reported the synthesis of polystyrene@(silver–polypyrrole) (PS@(Ag–PPy)) nanocomposite microspheres with the well-defined core/shell structure, in which the functionalized PS microspheres by the sulfonic acid groups were employed as template. The diameter of the synthesized PS microsphere template and AgNP was 1.26 μm and 50 nm, respectively. In order to well control the redox reaction between Ag{sup +} and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA){sub 2}]{sup +}) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO{sub 3} and Py, the introduction of [Ag(TEA){sub 2}]{sup +} ions resulted in the improved coverage and distribution of AgNPs around the surface of PS microspheres. Meanwhile, the loading amount of Ag–PPy nanocomposites on the final microspheres was adjustable. The increasing concentrations of Py monomer and [Ag(TEA){sub 2}]{sup +} ions resulted in the increase of Ag–PPy nanocomposite loading. The results of antibacterial experiment suggested that the synthesized PS@(Ag–PPy) composite microspheres showed the prominent antibacterial properties against both the Gram-negative bacteria of Escherichia coli and the Gram-positive bacteria of Staphylococcus aureus. For the bacteria with concentration at 1 × 10{sup 5} – 9×10{sup 5} cfu/mL, the microspheres can kill the bacteria above 3-log reduction with the concentration of PS@(Ag–PPy) composite microspheres at 50 μg/mL, in which the weight fraction of Py in the composite microspheres was above 10 wt%. When the weight fraction of Py in the composite microspheres was at 5 wt%, the 2-log reduction of in bacterial viability could also be obtained.Graphical Abstract.

  16. Green synthesis of core-shell gold-palladium@palladium nanocrystals dispersed on graphene with enhanced catalytic activity toward oxygen reduction and methanol oxidation in alkaline media

    Zheng, Jie-Ning; Li, Shan-Shan; Ma, Xiaohong; Chen, Fang-Yi; Wang, Ai-Jun; Chen, Jian-Rong; Feng, Jiu-Ju

    2014-09-01

    Well-defined core-shell gold-palladium@palladium nanocrystals (AuPd@Pd) are facilely prepared by a simple and green wet-chemical method at 25 °C. A Good's buffer, 2-[4-(2-hydroxyethyl)-1-piperazinyl] ethanesulfonic acid (HEPES), is used as a reducing agent and a shape-directing agent, while there is no template, seed, organic solvent, or surfactant involved. The AuPd@Pd nanocrystals are uniformly dispersed on graphene nanosheets by ultrasonication, resulting in the formation of graphene supported AuPd@Pd (G-AuPd@Pd). The as-prepared nanocomposites exhibit the improved catalytic activity, good tolerance, and better stability for oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR) in alkaline media, compared with the G-Pd and commercial Pd black catalysts. The as-developed method may provide a promising pathway for large-scale fabrication of AuPd-based catalysts.

  17. Influence Of Tools Input/Output Requirements On Managers Core Front End Activities In New Product Development

    Appio, Francesco P.; Achiche, Sofiane; Minin, Alberto Di

    2011-01-01

    The object of analysis of this explorative research is the Fuzzy Front End of Innovation in Product Development, described by those activities going from the opportunity identification to the concept definition. Business scholars have shown that confusion in terms of goals and different ideas about...... opportunities; make this early phase of the innovation process uncertain and extremely risky. Literature suggests that the understanding, selection and use of appropriate tools/techniques to support decision making are instrumental for a less fuzzy front end of innovation. This paper considers the adoption...

  18. Geomorphic response of an active metamorphic core-complex in a collisional orogen: Example from the Lunggar Shan, Southern Tibet

    Taylor, M H; Stockli, D F [Department of Geology, University of Kansas, 1475 Jayhawk Blvd., Lawrence, KS 66044 (United States); Kapp, P A [Department of Geosciences, University of Arizona, Tucson, AZ (United States)], E-mail: mht@ku.edu

    2008-07-01

    We present structural and neotectonic mapping from the Lunggar Shan rift in southern Tibet. The Lunggar Shan is a N-trending mountain range {approx}70 km long N-S and up to 40 km wide E-W. The Lunggar Shan is bounded on its east side by a low-angle (<40{sup 0}) east-dipping detachment fault that juxtaposes mylonitic gneiss and variably deformed granites in its footwall against alluvial fans and Neogene gravels in its hangingwall. Foliations in the mylonitic footwall dip < 40 deg. east and stretching lineations are east plunging. The range front detachment is presently inactive as indicated by undisturbed moraines and Quaternary sediments that overlie it. However, we consider the Lunggar Shan detachment to be an active structure, as inferred by range parallel fault scarps cutting Quaternary alluvium located 4-5 km into the hangingwall basin, with >40 m of throw on individual scarps. An intriguing observation is that an intrabasinal topographic high is actively developing near areas of inferred maximum extension, with lacustrine sediments being uplifted and eroded. This observation indicates that the rift basin initially developed as a typical half-graben system that underwent a transition from deposition, to uplift and erosion perhaps as a result of isostatic rebound of the footwall at depth, warping the overlying hangingwall basin. If correct, the Lunggar Shan may represent a modern analogue to the supradetachment basin model.

  19. Algorithm refinement for fluctuating hydrodynamics

    Williams, Sarah A.; Bell, John B.; Garcia, Alejandro L.

    2007-07-03

    This paper introduces an adaptive mesh and algorithmrefinement method for fluctuating hydrodynamics. This particle-continuumhybrid simulates the dynamics of a compressible fluid with thermalfluctuations. The particle algorithm is direct simulation Monte Carlo(DSMC), a molecular-level scheme based on the Boltzmann equation. Thecontinuum algorithm is based on the Landau-Lifshitz Navier-Stokes (LLNS)equations, which incorporate thermal fluctuations into macroscopichydrodynamics by using stochastic fluxes. It uses a recently-developedsolver for LLNS, based on third-order Runge-Kutta. We present numericaltests of systems in and out of equilibrium, including time-dependentsystems, and demonstrate dynamic adaptive refinement by the computationof a moving shock wave. Mean system behavior and second moment statisticsof our simulations match theoretical values and benchmarks well. We findthat particular attention should be paid to the spectrum of the flux atthe interface between the particle and continuum methods, specificallyfor the non-hydrodynamic (kinetic) time scales.

  20. Thermal fluctuations in loop cosmology

    Magueijo, J; Magueijo, Joao; Singh, Parampreet

    2007-01-01

    Quantum gravitational effects in loop quantum cosmology lead to a resolution of the initial singularity and have the potential to solve the horizon problem and generate a quasi scale-invariant spectrum of density fluctuations. We consider loop modifications to the behavior of the inverse scale factor below a critical scale in closed models and assume a purely thermal origin for the fluctuations. We show that the no-go results for scale invariance in classical thermal models can be evaded even if we just consider modifications to the background (zeroth order) gravitational dynamics. Since a complete and systematic treatment of the perturbed Einstein equations in loop cosmology is still lacking, we simply parameterize their expected modifications. These change quantitatively, but not qualitatively, our conclusions. We thus urge the community to more fully work out this complex aspect of loop cosmology, since the full picture would not only fix the free parameters of the theory, but also provide a model for a no...

  1. Dissipative Dynamics of Quantum Fluctuations

    Benatti, F; Floreanini, R

    2015-01-01

    One way to look for complex behaviours in many-body quantum systems is to let the number $N$ of degrees of freedom become large and focus upon collective observables. Mean-field quantities scaling as $1/N$ tend to commute, whence complexity at the quantum level can only be inherited from complexity at the classical level. Instead, fluctuations of microscopic observables scale as $1/\\sqrt{N}$ and exhibit collective Bosonic features, typical of a mesoscopic regime half-way between the quantum one at the microscopic level and the classical one at the level of macroscopic averages. Here, we consider the mesoscopic behaviour emerging from an infinite quantum spin chain undergoing a microscopic dissipative, irreversible dynamics and from global states without long-range correlations and invariant under lattice translations and dynamics. We show that, from the fluctuations of one site spin observables whose linear span is mapped into itself by the dynamics, there emerge bosonic operators obeying a mesoscopic dissipa...

  2. Phosphoproteomic analysis of protein kinase C signaling in Saccharomyces cerevisiae reveals Slt2 mitogen-activated protein kinase (MAPK)-dependent phosphorylation of eisosome core components.

    Mascaraque, Victoria; Hernáez, María Luisa; Jiménez-Sánchez, María; Hansen, Rasmus; Gil, Concha; Martín, Humberto; Cid, Víctor J; Molina, María

    2013-03-01

    The cell wall integrity (CWI) pathway of the model organism Saccharomyces cerevisiae has been thoroughly studied as a paradigm of the mitogen-activated protein kinase (MAPK) pathway. It consists of a classic MAPK module comprising the Bck1 MAPK kinase kinase, two redundant MAPK kinases (Mkk1 and Mkk2), and the Slt2 MAPK. This module is activated under a variety of stimuli related to cell wall homeostasis by Pkc1, the only member of the protein kinase C family in budding yeast. Quantitative phosphoproteomics based on stable isotope labeling of amino acids in cell culture is a powerful tool for globally studying protein phosphorylation. Here we report an analysis of the yeast phosphoproteome upon overexpression of a PKC1 hyperactive allele that specifically activates CWI MAPK signaling in the absence of external stimuli. We found 82 phosphopeptides originating from 43 proteins that showed enhanced phosphorylation in these conditions. The MAPK S/T-P target motif was significantly overrepresented in these phosphopeptides. Hyperphosphorylated proteins provide putative novel targets of the Pkc1-cell wall integrity pathway involved in diverse functions such as the control of gene expression, protein synthesis, cytoskeleton maintenance, DNA repair, and metabolism. Remarkably, five components of the plasma-membrane-associated protein complex known as eisosomes were found among the up-regulated proteins. We show here that Pkc1-induced phosphorylation of the eisosome core components Pil1 and Lsp1 was not exerted directly by Pkc1, but involved signaling through the Slt2 MAPK module.

  3. Molecular fluctuation in living cells

    唐孝威

    1997-01-01

    The concept of molecular fluctuation in living cells is introduced. Many apparently different experi-mental facts in living cells, including the velocity non-uniformity of organelle movement, the saltatory movement of transport vesicles in axoplasmic transport, the chromosome oscillation during metaphase in mitosis and the pauses in the chromosome movement during anaphase are explained using a unified viewpoint. A method of determination of average number of the attached motor protein molecules from the experimental data is also proposed.

  4. Random numbers from vacuum fluctuations

    Shi, Yicheng; Chng, Brenda; Kurtsiefer, Christian

    2016-07-01

    We implement a quantum random number generator based on a balanced homodyne measurement of vacuum fluctuations of the electromagnetic field. The digitized signal is directly processed with a fast randomness extraction scheme based on a linear feedback shift register. The random bit stream is continuously read in a computer at a rate of about 480 Mbit/s and passes an extended test suite for random numbers.

  5. Chemical Measurement and Fluctuation Scaling.

    Hanley, Quentin S

    2016-12-20

    Fluctuation scaling reports on all processes producing a data set. Some fluctuation scaling relationships, such as the Horwitz curve, follow exponential dispersion models which have useful properties. The mean-variance method applied to Poisson distributed data is a special case of these properties allowing the gain of a system to be measured. Here, a general method is described for investigating gain (G), dispersion (β), and process (α) in any system whose fluctuation scaling follows a simple exponential dispersion model, a segmented exponential dispersion model, or complex scaling following such a model locally. When gain and dispersion cannot be obtained directly, relative parameters, GR and βR, may be used. The method was demonstrated on data sets conforming to simple, segmented, and complex scaling. These included mass, fluorescence intensity, and absorbance measurements and specifications for classes of calibration weights. Changes in gain, dispersion, and process were observed in the scaling of these data sets in response to instrument parameters, photon fluxes, mathematical processing, and calibration weight class. The process parameter which limits the type of statistical process that can be invoked to explain a data set typically exhibited 0 4 possible. With two exceptions, calibration weight class definitions only affected β. Adjusting photomultiplier voltage while measuring fluorescence intensity changed all three parameters (0 < α < 0.8; 0 < βR < 3; 0 < GR < 4.1). The method provides a framework for calibrating and interpreting uncertainty in chemical measurement allowing robust comparison of specific instruments, conditions, and methods.

  6. Fluctuating hydrodynamics for ionic liquids

    Lazaridis, Konstantinos; Wickham, Logan; Voulgarakis, Nikolaos

    2017-04-01

    We present a mean-field fluctuating hydrodynamics (FHD) method for studying the structural and transport properties of ionic liquids in bulk and near electrified surfaces. The free energy of the system consists of two competing terms: (1) a Landau-Lifshitz functional that models the spontaneous separation of the ionic groups, and (2) the standard mean-field electrostatic interaction between the ions in the liquid. The numerical approach used to solve the resulting FHD-Poisson equations is very efficient and models thermal fluctuations with remarkable accuracy. Such density fluctuations are sufficiently strong to excite the experimentally observed spontaneous formation of liquid nano-domains. Statistical analysis of our simulations provides quantitative information about the properties of ionic liquids, such as the mixing quality, stability, and the size of the nano-domains. Our model, thus, can be adequately parameterized by directly comparing our prediction with experimental measurements and all-atom simulations. Conclusively, this work can serve as a practical mathematical tool for testing various theories and designing more efficient mixtures of ionic liquids.

  7. Ghrelin receptor inverse agonists: identification of an active peptide core and its interaction epitopes on the receptor

    Holst, Birgitte; Lang, Manja; Brandt, Erik

    2006-01-01

    (TM)-III, TM-VI and TM-VII]. In contrast, the inverse agonist peptides bind in a pocket that extends all the way from the extracellular end of TM-II (AspII:20) across between TM-III and TM-VI/VII to TM-V and TM-IV. The potency of the main inverse agonist could be improved up to 20-fold by a number...... of space-generating mutants located relatively deep in the binding pocket at key positions in TM-III, TM-IV and TM-V. It is proposed that the inverse agonists prevent the spontaneous receptor activation by inserting relatively deeply across the main ligand-binding pocket and sterically blocking...

  8. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores I. Single Nanoflares

    Barnes, W T; Bradshaw, S J

    2016-01-01

    The properties expected of "hot" non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the EBTEL code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK that is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium and, for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the "smoking gun" of nanoflare heating, lies between $10^{6.6}$ and $10^7$ K. Signatures of the actual heating may be detectable in some instances.

  9. Inference of Heating Properties from "Hot" Non-flaring Plasmas in Active Region Cores. I. Single Nanoflares

    Barnes, W. T.; Cargill, P. J.; Bradshaw, S. J.

    2016-09-01

    The properties that are expected of “hot” non-flaring plasmas due to nanoflare heating in active regions are investigated using hydrodynamic modeling tools, including a two-fluid development of the Enthalpy Based Thermal Evolution of Loops code. Here we study a single nanoflare and show that while simple models predict an emission measure distribution extending well above 10 MK, which is consistent with cooling by thermal conduction, many other effects are likely to limit the existence and detectability of such plasmas. These include: differential heating between electrons and ions, ionization non-equilibrium, and for short nanoflares, the time taken for the coronal density to increase. The most useful temperature range to look for this plasma, often called the “smoking gun” of nanoflare heating, lies between 106.6 and 107 K. Signatures of the actual heating may be detectable in some instances.

  10. Correlated interaction fluctuations in photosynthetic complexes

    Vlaming, Sebastiaan M

    2011-01-01

    The functioning and efficiency of natural photosynthetic complexes is strongly influenced by their embedding in a noisy protein environment, which can even serve to enhance the transport efficiency. Interactions with the environment induce fluctuations of the transition energies of and interactions between the chlorophyll molecules, and due to the fact that different fluctuations will partially be caused by the same environmental factors, correlations between the various fluctuations will occur. We argue that fluctuations of the interactions should in general not be neglected, as these have a considerable impact on population transfer rates, decoherence rates and the efficiency of photosynthetic complexes. Furthermore, while correlations between transition energy fluctuations have been studied, we provide the first quantitative study of the effect of correlations between interaction fluctuations and transition energy fluctuations, and of correlations between the various interaction fluctuations. It is shown t...

  11. Classical enhancement of quantum vacuum fluctuations

    De Lorenci, V A

    2016-01-01

    We propose a mechanism for the enhancement of vacuum fluctuations by means of a classical field. The basic idea is that if an observable quantity depends quadratically upon a quantum field, such as the electric field, then the application of a classical field produces a cross term between the classical and quantum fields. This cross term may be significantly larger than the purely quantum part, but also undergoes fluctuations driven by the quantum field. We illustrate this effect in a model for lightcone fluctuations involving pulses in a nonlinear dielectric. Vacuum electric field fluctuations produce fluctuations in the speed of a probe pulse, and form an analog model for quantum gravity effects. If the material has a nonzero third-order susceptibility, then the fractional light speed fluctuations are proportional to the square of the fluctuating electric field. Hence the application of a classical electric field can enhance the speed fluctuations. We give an example where this enhancement can be an increas...

  12. Predicting growth fluctuation in network economy

    Maeno, Yoshiharu

    2011-01-01

    This study presents a method to predict the growth fluctuation of firms interdependent in a network economy. The risk of downward growth fluctuation of firms is calculated from the statistics on Japanese industry.

  13. Glucagon-like peptide 1 (GLP-1) can reverse AMP-activated protein kinase (AMPK) and S6 kinase (P70S6K) activities induced by fluctuations in glucose levels in hypothalamic areas involved in feeding behaviour.

    Hurtado-Carneiro, Verónica; Sanz, Carmen; Roncero, Isabel; Vazquez, Patricia; Blazquez, Enrique; Alvarez, Elvira

    2012-04-01

    The anorexigenic peptide, glucagon-like peptide-1 (GLP-1), reduces glucose metabolism in the human hypothalamus and brain stem. The brain activity of metabolic sensors such as AMP-activated protein kinase (AMPK) responds to changes in glucose levels. The mammalian target of rapamycin (mTOR) and its downstream target, p70S6 kinase (p70S6K), integrate nutrient and hormonal signals. The hypothalamic mTOR/p70S6K pathway has been implicated in the control of feeding and the regulation of energy balances. Therefore, we investigated the coordinated effects of glucose and GLP-1 on the expression and activity of AMPK and p70S6K in the areas involved in the control of feeding. The effect of GLP-1 on the expression and activities of AMPK and p70S6K was studied in hypothalamic slice explants exposed to low- and high-glucose concentrations by quantitative real-time RT-PCR and by the quantification of active-phosphorylated protein levels by immunoblot. In vivo, the effects of exendin-4 on hypothalamic AMPK and p70S6K activation were analysed in male obese Zucker and lean controls 1 h after exendin-4 injection to rats fasted for 48 h or after re-feeding for 2-4 h. High-glucose levels decreased the expression of Ampk in the lateral hypothalamus and treatment with GLP-1 reversed this effect. GLP-1 treatment inhibited the activities of AMPK and p70S6K when the activation of these protein kinases was maximum in both the ventromedial and lateral hypothalamic areas. Furthermore, in vivo s.c. administration of exendin-4 modulated AMPK and p70S6K activities in those areas, in both fasted and re-fed obese Zucker and lean control rats.

  14. Fluctuation and dissipation in liquid crystal electroconvection

    Goldburg, Walter I.; Goldschmidt, Yadin Y.; Kellay, Hamid

    2002-11-01

    The power dissipation P( t) was measured in a liquid crystal (MBBA) driven by an ac voltage into the chaotic electroconvective state. In that state, the power fluctuates about its mean value . The quantity measured, and compared with the fluctuation theorem of Gallavotti and Cohen, is the dimensionless standard deviation of the fluctuations, σP/.

  15. A tale of two eras: Pliocene-Pleistocene unroofing of Cenozoic and late Archean zircons from active metamorphic core complexes, Solomon Sea, Papua New Guinea

    Baldwin, Suzanne L.; Ireland, Trevor R.

    1995-11-01

    U/Pb ion microprobe analyses of zircons from gneisses and granodiorites exposed in the D'Entrecasteaux Islands, and from conglomerate sections of the Goodenough No. 1 well in the adjacent Trobriand Basin, provide constraints on the age of magmatism, peak metamorphism, and nature of rocks unroofed during initial stages of metamorphic core complex formation in the Solomon Sea. The youngest populations of zircons from felsic gneisses and granodiorites indicate late Pliocene 206Pb*/238U ages. No inherited zircons were identified in the granodiorites, and the 206Pb*/238U ages (1.65 ± 0.18 Ma; 1.98 ± 0.08 Ma [2σ]) are interpreted as crystallization ages. These synkinematically emplaced granodiorites, intruded into actively extending continental crust, are some of the youngest known granitoids currently exposed at the Earth' surface. Zircon ages from felsic gneisses (2.63 ± 0.16 Ma; 2.72 ± 0.28 Ma [2σ]) are interpreted to date zircon growth subsequent to eclogite facies metamorphism. Felsic gneiss samples also contained zircon xenocrysts from Cretaceous-Miocene protoliths. In striking contrast, zircons from igneous and metamorphic clasts from the Goodenough No. 1 well indicate a single population with a 207Pb*/206/Pb* age of 2781 ± 9 Ma (2σ). We speculate that they are derived from basement rocks unroofed during initial stages of development of the D&Entrecasteaux metamorphic core complexes. These results provide the first direct evidence for the existence of Archean protoliths in the basement rocks of southeastern Papua New Guinea.

  16. Production and purification of immunologically active core protein p24 from HIV-1 fused to ricin toxin B subunit in E. coli

    Gómez-Lim Miguel A

    2009-02-01

    Full Text Available Abstract Background Gag protein from HIV-1 is a polyprotein of 55 kDa, which, during viral maturation, is cleaved to release matrix p17, core p24 and nucleocapsid proteins. The p24 antigen contains epitopes that prime helper CD4 T-cells, which have been demonstrated to be protective and it can elicit lymphocyte proliferation. Thus, p24 is likely to be an integral part of any multicomponent HIV vaccine. The availability of an optimal adjuvant and carrier to enhance antiviral responses may accelerate the development of a vaccine candidate against HIV. The aim of this study was to investigate the adjuvant-carrier properties of the B ricin subunit (RTB when fused to p24. Results A fusion between ricin toxin B subunit and p24 HIV (RTB/p24 was expressed in E. coli. Affinity chromatography was used for purification of p24 alone and RTB/p24 from cytosolic fractions. Biological activity of RTB/p24 was determined by ELISA and affinity chromatography using the artificial receptor glycoprotein asialofetuin. Both assays have demonstrated that RTB/p24 is able to interact with complex sugars, suggesting that the chimeric protein retains lectin activity. Also, RTB/p24 was demonstrated to be immunologically active in mice. Two weeks after intraperitoneal inoculation with RTB/p24 without an adjuvant, a strong anti-p24 immune response was detected. The levels of the antibodies were comparable to those found in mice immunized with p24 alone in the presence of Freund adjuvant. RTB/p24 inoculated intranasally in mice, also elicited significant immune responses to p24, although the response was not as strong as that obtained in mice immunized with p24 in the presence of the mucosal adjuvant cholera toxin. Conclusion In this work, we report the expression in E. coli of HIV-1 p24 fused to the subunit B of ricin toxin. The high levels of antibodies obtained after intranasal and intraperitoneal immunization of mice demonstrate the adjuvant-carrier properties of RTB when

  17. Formulation and preparation of Hanford Waste Treatment Plant direct feed low activity waste Effluent Management Facility core simulant

    McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL; Adamson, Duane J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL

    2016-05-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator in the Effluent Management Facility (EMF) and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would enable less integrated operation of the LAW melter and the Pretreatment Facilities. Alternate disposition would also eliminate this stream from recycling within WTP when it begins operations and would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other problems such a recycle stream present. This LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures and are problematic for the glass waste form, such as halides and sulfate. Because this stream will recycle within WTP, these components accumulate in the Melter Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Diverting the stream reduces the halides and sulfate in the recycled Condensate and is a key outcome of this work. This overall program examines the potential treatment and immobilization of this stream to enable alternative disposal. The objective of this task was to formulate and prepare a simulant of the LAW Melter

  18. Formulation and preparation on Hanford Waste Treatment Plan direct feed low activity waste effluent management facility core simulant

    McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL; Adamson, Duane J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL

    2016-05-01

    The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate, LMOGC) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator in the Effluent Management Facility (EMF) and then return it to the LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of the LMOGC stream would eliminate recycling of problematic components, and would enable less integrated operation of the LAW melter and the Pretreatment Facilities. Alternate disposition would also eliminate this stream from recycling within WTP when it begins operations and would decrease the LAW vitrification mission duration and quantity of glass waste, amongst the other problems such a recycle stream present. This LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures and are problematic for the glass waste form, such as halides and sulfate. Because this stream will recycle within WTP, these components accumulate in the Melter Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Diverting the stream reduces the halides and sulfate in the recycled Condensate and is a key outcome of this work. This overall program examines the potential treatment and immobilization of this stream to enable alternative disposal. The objective of this task was to formulate and prepare a simulant of the LAW Melter

  19. Hetero-metallic trigonal cage-shaped dimeric Ni3K core complex of L-proline ligand: Synthesis, structural, electrochemical and DNA binding and cleavage activities

    S Nagasubramanian; A Jayamani; V Thamilarasan; G Aravindan; V Ganesan; N Sengottuvelan

    2014-05-01

    Hetero-metallic trigonal cage-shaped dimeric Ni3K core complex of L-proline ligand has been synthesized and characterized. Single crystal X-ray diffraction analysis showed that the hetero-metallic Ni(II)-K(I) complex has a dimeric structure with nine coordinated potassium atoms and six coordinated nickel atoms. The cyclic voltammograms of the complex exhibited two successive quasireversible reduction waves at ($E^{1}_{pc} = −1.02$ V and $E^{2}_{pc} = −1.33$ V) and two successive irreversible oxidation waves ($E^{1}_{pa} = 0.95$ V and $E^{2}_{pa} = 1.45$ V) versus Ag/AgCl in DMF solution. Interaction of the complex with calf-thymus DNA (CT DNA) has been studied using spectroscopic techniques. The complex is an avid DNA binder with a binding constant of 3.6 × 108 M-1. The complex showed efficient oxidative cleavage of supercoiled pBR322 DNA in the presence of the reducing agent hydrogen peroxide involving hydroxyl radical (°OH) species. As evidenced from the control experiment, DNA cleavage in the presence of °OH radical was inhibited by quenchers, viz. DMSO and KI. The complex showed in vitro antimicrobial activity against four bacteria and two fungi and the activity is greater than that of the free ligand.

  20. Core-shell N-doped active carbon fiber@graphene composites for aqueous symmetric supercapacitors with high-energy and high-power density

    Xie, Qinxing; Bao, Rongrong; Xie, Chao; Zheng, Anran; Wu, Shihua; Zhang, Yufeng; Zhang, Renwei; Zhao, Peng

    2016-06-01

    Graphene wrapped nitrogen-doped active carbon fibers (ACF@GR) of a core-shell structure were successfully prepared by a simple dip-coating method using natural silk as template. Compared to pure silk active carbon, the as-prepared ACF@GR composites exhibit high specific surface area in a range of 1628-2035 m2 g-1, as well as superior energy storage capability, an extremely high single-electrode capacitance of 552.8 F g-1 was achieved at a current density of 0.1 A g-1 in 6 M KOH aqueous electrolyte. The assembled aqueous symmetric supercapacitors are capable of deliver both high energy density and high power density, for instance, 17.1 Wh kg-1 at a power density of 50.0 W kg-1, and 12.2 Wh kg-1 at 4.7 kW kg-1 with a retention rate of 71.3% for ACF@GR1-based supercapacitor.

  1. The core domain of Aquifex aeolicus tRNA (m7G46) methyltransferase has the methyl-transfer activity to tRNA.

    Tomikawa, Chie; Hori, Hiroyuki

    2006-01-01

    Transfer RNA (m(7)G46) methyltransferase [TrmB] catalyses the transfer of methyl groups from S-adenosyl-L-methionine to the N(7)-atom of guanine at position 46 in tRNA. TrmB proteins from thermophilic bacteria such as Aquifex aeolicus have a long C-terminal region as compared to those from mesophilic bacteria. Further, N-terminal region observed in TrmB proteins from mesophiles is missing in A. aeolicus TrmB. Therefore, we considered that this distinct C-terminal region in A. aeolicus TrmB might compensate the N-terminal region in mesophile TrmB and function as a part of tRNA binding site. To confirm this idea, we deleted the C-terminal region by introduction of the stop codon at position 202. To our surprise, methyl-transfer assay using yeast tRNA(Phe) transcript clearly showed that the resultant mutant protein (Glu202Stop) had an enzymatic activity. Thus, the core domain of the A. aeolicus TrmB has a methyl-transfer activity.

  2. From cusps to cores: a stochastic model

    El-Zant, Amr A.; Freundlich, Jonathan; Combes, Françoise

    2016-09-01

    The cold dark matter model of structure formation faces apparent problems on galactic scales. Several threads point to excessive halo concentration, including central densities that rise too steeply with decreasing radius. Yet, random fluctuations in the gaseous component can `heat' the centres of haloes, decreasing their densities. We present a theoretical model deriving this effect from first principles: stochastic variations in the gas density are converted into potential fluctuations that act on the dark matter; the associated force correlation function is calculated and the corresponding stochastic equation solved. Assuming a power-law spectrum of fluctuations with maximal and minimal cutoff scales, we derive the velocity dispersion imparted to the halo particles and the relevant relaxation time. We further perform numerical simulations, with fluctuations realized as a Gaussian random field, which confirm the formation of a core within a time-scale comparable to that derived analytically. Non-radial collective modes enhance the energy transport process that erases the cusp, though the parametrizations of the analytical model persist. In our model, the dominant contribution to the dynamical coupling driving the cusp-core transformation comes from the largest scale fluctuations. Yet, the efficiency of the transformation is independent of the value of the largest scale and depends weakly (linearly) on the power-law exponent; it effectively depends on two parameters: the gas mass fraction and the normalization of the power spectrum. This suggests that cusp-core transformations observed in hydrodynamic simulations of galaxy formation may be understood and parametrized in simple terms, the physical and numerical complexities of the various implementations notwithstanding.

  3. 5th International Conference on Valence Fluctuations

    Malik, S

    1987-01-01

    During the Koln meeting (August 28-31, 1984), Irdia was chosen as the venue for the next International Conference on Valence Fluctuations. lhis was in recognition ard appreciation of the work done, both experimental ard theoretical, by the Irdian scientists in this area during the last decade. We decided to hold this Conference in the month of January, 1987 at Bangalore. lhe subject of Valence Fluctuations has kept itself alive ard active as it has provided many shocks ard suprises particularly among the Ce- ard U-based intermetallies. lhe richness of many interesting physical phenomena occurring in mixed valent materials, the flexibility of modifying their physical properties (by alloying, for example) ard the possibility of synthesizing a wide variety of new such materials seem to be the key factors in this regard. Barely six months before this Conference, an International Conference on Anomalous Rare Earths and Actinides (ICAREA) had been held at Grenoble (July, 1986) which also focussed on mixed valence a...

  4. Direct measurement of antiferromagnetic domain fluctuations.

    Shpyrko, O. G.; Isaacs, E. D.; Logan, J. M.; Feng, Y.; Aeppli, G.; Jaramillo, R.; Kim, H. C.; Rosenbaum, T. F.; Zschack, P.; Sprung, M.; Narayanan, S.; Sandy, A.; Univ. of Chicago; Univ. College London

    2007-05-03

    Measurements of magnetic noise emanating from ferromagnets owing to domain motion were first carried out nearly 100 years ago1, and have underpinned much science and technology2, 3. Antiferromagnets, which carry no net external magnetic dipole moment, yet have a periodic arrangement of the electron spins extending over macroscopic distances, should also display magnetic noise. However, this must be sampled at spatial wavelengths of the order of several interatomic spacings, rather than the macroscopic scales characteristic of ferromagnets. Here we present a direct measurement of the fluctuations in the nanometer-scale superstructure of spin- and charge-density waves associated with antiferromagnetism in elemental chromium. The technique used is X-ray photon correlation spectroscopy, where coherent X-ray diffraction produces a speckle pattern that serves as a 'fingerprint' of a particular magnetic domain configuration. The temporal evolution of the patterns corresponds to domain walls advancing and retreating over micrometer distances. This work demonstrates a useful measurement tool for antiferromagnetic domain wall engineering, but also reveals a fundamental finding about spin dynamics in the simplest antiferromagnet: although the domain wall motion is thermally activated at temperatures above 100 K, it is not so at lower temperatures, and indeed has a rate that saturates at a finite value--consistent with quantum fluctuations--on cooling below 40 K.

  5. Variable diffusion in stock market fluctuations

    Hua, Jia-Chen; Chen, Lijian; Falcon, Liberty; McCauley, Joseph L.; Gunaratne, Gemunu H.

    2015-02-01

    We analyze intraday fluctuations in several stock indices to investigate the underlying stochastic processes using techniques appropriate for processes with nonstationary increments. The five most actively traded stocks each contains two time intervals during the day where the variance of increments can be fit by power law scaling in time. The fluctuations in return within these intervals follow asymptotic bi-exponential distributions. The autocorrelation function for increments vanishes rapidly, but decays slowly for absolute and squared increments. Based on these results, we propose an intraday stochastic model with linear variable diffusion coefficient as a lowest order approximation to the real dynamics of financial markets, and to test the effects of time averaging techniques typically used for financial time series analysis. We find that our model replicates major stylized facts associated with empirical financial time series. We also find that ensemble averaging techniques can be used to identify the underlying dynamics correctly, whereas time averages fail in this task. Our work indicates that ensemble average approaches will yield new insight into the study of financial markets' dynamics. Our proposed model also provides new insight into the modeling of financial markets dynamics in microscopic time scales.

  6. Effect of Fluctuating Temperatures on Forest Soil Nitrogen Minerealization

    LIAOLIPING; P.INESON

    1997-01-01

    Nitrogen mineralization in forest soil wa studied in laboratory by incubating undisturbed soil cores enclosed within PVC columns at different temperatures to compare the effect of flucttuating temperature with that of constant temperaature,and to find out whether soil nitrification shows linearity over time .The results showed that there was no significant difference between soil nitrification at fluctuating temperature and that at constant temperature,and suggested that it must be careful to make the conclusion that soil nitrification has linearity over time.

  7. A suggested emergency medicine boot camp curriculum for medical students based on the mapping of Core Entrustable Professional Activities to Emergency Medicine Level 1 milestones

    Lamba S

    2016-03-01

    Full Text Available Sangeeta Lamba, Bryan Wilson, Brenda Natal, Roxanne Nagurka, Michael Anana, Harsh Sule Department of Emergency Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA Background: An increasing number of students rank Emergency Medicine (EM as a top specialty choice, requiring medical schools to provide adequate exposure to EM. The Core Entrustable Professional Activities (EPAs for Entering Residency by the Association of American Medical Colleges combined with the Milestone Project for EM residency training has attempted to standardize the undergraduate and graduate medical education goals. However, it remains unclear as to how the EPAs correlate to the milestones, and who owns the process of ensuring that an entering EM resident has competency at a certain minimum level. Recent trends establishing specialty-specific boot camps prepare students for residency and address the variability of skills of students coming from different medical schools. Objective: Our project’s goal was therefore to perform a needs assessment to inform the design of an EM boot camp curriculum. Toward this goal, we 1 mapped the core EPAs for graduating medical students to the EM residency Level 1 milestones in order to identify the possible gaps/needs and 2 conducted a pilot procedure workshop that was designed to address some of the identified gaps/needs in procedural skills. Methods: In order to inform the curriculum of an EM boot camp, we used a systematic approach to 1 identify gaps between the EPAs and EM milestones (Level 1 and 2 determine what essential and supplemental competencies/skills an incoming EM resident should ideally possess. We then piloted a 1-day, three-station advanced ABCs procedure workshop based on the identified needs. A pre-workshop test and survey assessed knowledge, preparedness, confidence, and perceived competence. A post-workshop survey evaluated the program, and a posttest combined with psychomotor skills test using three

  8. Fluctuations in some climate parameters

    Erlykin, A D; Wolfendale, A W; 10.1016/j.jastp.2011.01.021

    2011-01-01

    There is argument as to the extent to which there has been an increase over the past few decades in the frequency of the extremes of climatic parameters, such as temperature, storminess, precipitation, etc, an obvious point being that Global Warming might be responsible. Here we report results on those parameters of which we have had experience during the last few years: Global surface temperature, Cloud Cover and the MODIS Liquid Cloud Fraction. In no case we have found indications that fluctuations of these parameters have increased with time.

  9. Fluctuations of the unruh temperature

    Demers, J G

    1994-01-01

    Using the influence functional formalism, the problem of an accelerating detector in the presence of a scalar field in its ground state is considered in Minkowski space. As is known since the work of Unruh, to a quantum mechanical detector following a definite, classical acceleration, the field appears to be thermally excited. We relax the requirement of perfect classicality for the trajectory and substitute it with one of {\\it derived} classicality through the criteria of decoherence. The ensuing fluctuations in temperature are then related with the time and the amplitude of excitation in the detector's internal degree of freedom.

  10. Fluctuation modes of nanoconfined DNA.

    Karpusenko, Alena; Carpenter, Joshua H; Zhou, Chunda; Lim, Shuang Fang; Pan, Junhan; Riehn, Robert

    2012-01-15

    We report an experimental investigation of the magnitude of length and density fluctuations in DNA that has been stretched in nanofluidic channels. We find that the experimental data can be described using a one-dimensional overdamped oscillator chain with nonzero equilibrium spring length and that a chain of discrete oscillators yields a better description than a continuous chain. We speculate that the scale of these discrete oscillators coincides with the scale at which the finite extensibility of the polymer manifests itself. We discuss how the measurement process influences the apparent measured dynamic properties, and outline requirements for the recovery of true physical quantities.

  11. Quantum Fluctuations Of The Stress Tensor

    Wu, C

    2002-01-01

    Quantum fluctuations of the stress tensor are important in many branches of physics, including the study of the validity of semiclassical gravity and the backreaction problem in stochastic semiclassical gravity. The geometry fluctuations induced by stress tensor fluctuations are important to understand quantum gravity and the problem of lightcone fluctuations. Stress tensor fluctuations also hold the key to understand fundamental physical effects like quantum fluctuations of radiation pressure, and that is crucial to the sensitivity of interferometers and the limitations on the detection of gravitational waves. Even the wave-particle duality of light can be better understood by the study of quantum fluctuations of thermal radiation. It is well known in quantum field theory that the expectation value of the energy density, which contains quadratic field operators (e.g. E2 and B2 in the electromagnatic field case), is divergent and can be renormalized simply by normal ordering, which is subtracting out the vac...

  12. Implantation of radiotelemetry transmitters yielding data on ECG, heart rate, core body temperature and activity in free-moving laboratory mice.

    Cesarovic, Nikola; Jirkof, Paulin; Rettich, Andreas; Arras, Margarete

    2011-11-21

    The laboratory mouse is the animal species of choice for most biomedical research, in both the academic sphere and the pharmaceutical industry. Mice are a manageable size and relatively easy to house. These factors, together with the availability of a wealth of spontaneous and experimentally induced mutants, make laboratory mice ideally suited to a wide variety of research areas. In cardiovascular, pharmacological and toxicological research, accurate measurement of parameters relating to the circulatory system of laboratory animals is often required. Determination of heart rate, heart rate variability, and duration of PQ and QT intervals are based on electrocardiogram (ECG) recordings. However, obtaining reliable ECG curves as well as physiological data such as core body temperature in mice can be difficult using conventional measurement techniques, which require connecting sensors and lead wires to a restrained, tethered, or even anaesthetized animal. Data obtained in this fashion must be interpreted with caution, as it is well known that restraining and anesthesia can have a major artifactual influence on physiological parameters. Radiotelemetry enables data to be collected from conscious and untethered animals. Measurements can be conducted even in freely moving animals, and without requiring the investigator to be in the proximity of the animal. Thus, known sources of artifacts are avoided, and accurate and reliable measurements are assured. This methodology also reduces interanimal variability, thus reducing the number of animals used, rendering this technology the most humane method of monitoring physiological parameters in laboratory animals. Constant advancements in data acquisition technology and implant miniaturization mean that it is now possible to record physiological parameters and locomotor activity continuously and in realtime over longer periods such as hours, days or even weeks. Here, we describe a surgical technique for implantation of a

  13. Study of Molecular Conformation and Activity-Related Properties of Lipase Immobilized onto Core-Shell Structured Polyacrylic Acid-Coated Magnetic Silica Nanocomposite Particles.

    Esmaeilnejad-Ahranjani, Parvaneh; Kazemeini, Mohammad; Singh, Gurvinder; Arpanaei, Ayyoob

    2016-04-01

    A facile approach for the preparation of core-shell structured poly(acrylic acid) (PAA)-coated Fe3O4 cluster@SiO2 nanocomposite particles as the support materials for the lipase immobilization is reported. Low- or high-molecular-weight (1800 and 100,000, respectively) PAA molecules were covalently attached onto the surface of amine-functionalized magnetic silica nanoacomposite particles. The successful preparation of particles were verified by scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), zeta potential measurement, and Fourier-transform infrared (FTIR) techniques. Once lipase is covalently immobilized onto the particles with an average diameter of 210 ± 50 nm, resulting from high binding sites concentrations on the low- and high-molecular-weight PAA-coated particles, high lipase immobilization efficiencies (86.2% and 89.9%, respectively), and loading capacities (786 and 816 mg g(-1), respectively) are obtained. Results from circular dichroism (CD) analysis and catalytic activity tests reveal an increase in the β-sheet content of lipase molecules upon immobilization, along with an enhancement in their activities and stabilities. The lipases immobilized onto the low- and high-molecular-weight PAA-coated particles show maximum activities at 55 and 50 °C, respectively, which are ∼28% and ∼15% higher than that of the free lipase at its own optimum temperature (40 °C), respectively. The immobilized lipases exhibit excellent performance at broader temperature and pH ranges and high thermal and storage stabilities, as well as superior reusability. These prepared magnetic nanocomposite particles can be offered as suitable support materials for efficient immobilization of enzymes and improvement of the immobilized enzymes properties.

  14. Dual-core antiresonant hollow core fibers.

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  15. Structural Evolution of Co-Based Metal Organic Frameworks in Pyrolysis for Synthesis of Core-Shells on Nanosheets: Co@CoOx@Carbon-rGO Composites for Enhanced Hydrogen Generation Activity.

    Xing, Congcong; Liu, Yanyan; Su, Yongheng; Chen, Yinghao; Hao, Shuo; Wu, Xianli; Wang, Xiangyu; Cao, Huaqiang; Li, Baojun

    2016-06-22

    In this article, Co-based metal organic frameworks (MOFs) with two shapes were used as pyrolysis precursor to synthesize multilayer core-shells composites loaded on reduced graphene oxide (rGO) sheets. The core-shell structures were obtained by the formation of cores from metal ions and carbon shells from carbonization of ligands. Controllable oxidation of Co cores to CoOx shells generated multilayer core-shell structures anchored onto the surface of rGO sheets. The N-doped composites were obtained by adding poly vinylpyrrolidone. The multilayer core-shells composites exhibited superior catalytic activity toward hydrogen generation compared to their single layer counterparts. By using the N-doped multilayer composites, high hydrogen generation specific rate of 5560 mL min(-1) gCo(-1) was achieved at room temperature. The rGO sheets in composites improved their structure stability. These catalysts exhibited high stability after used five cycling. This synergistic strategy proposes simple, efficient, and versatile blue-prints for the fabrication of rGO composites from MOFs-based precursors.

  16. Currency speculation and dollar fluctuations

    S. SCHULMEISTER

    2013-12-01

    Full Text Available In this study the reasons behind the wide fluctuations of the dollar exchange rate following the breakdown of the Bretton Woods system, for the most part unexplained by the prevailing exchange rate theories, are explored. The author investigates the exchange rate between the two most traded currencies, the dollar and the deutschemark, from 1973 to 1988. In the first part, the pattern of the daily exchange rate movements is examined to show that a sequence of upward and downward trends interrupted by non-directional movements is typical of exchange rate dynamics in the short run. This pattern is systemically exploited through currency speculation, particularly through the use of “technical analysis”. In the second part, the author focuses on the medium-term, arguing that fluctuations can be explained as the result of interacting disequilibria in the goods and asset markets. Although currency speculation has been systemically profitable for most currencies, it should be considered to be destabilising since the sequence of price runs caused large and persistent deviations of exchange rates from their equilibrium values (purchasing power parity.  

  17. Currency speculation and dollar fluctuations

    Stephan Schulmeister

    1988-12-01

    Full Text Available In this study the reasons behind the wide fluctuations of the dollar exchange rate following the breakdown of the Bretton Woods system, for the most part unexplained by the prevailing exchange rate theories, are explored. To do so, the author investigates the exchange rate between the two most traded currencies, the dollar and the deutschemark, from 1973 to 1988. In the first part, the pattern of the daily exchange rate movements is examined to show that a sequence of upward and downward trends interrupted by non-directional movements is typical of exchange rate dynamics in the short run. Moreover, this pattern is systemically exploited through currency speculation, particularly through the use of “technical analysis”. In the second part, the author focuses on the medium-term, arguing that fluctuations can be explained as the result of interacting disequilibria in the goods and asset markets. Although currency speculation has been systemically profitable for most currencies, it should be considered to be destabilizing since the sequence of price runs caused large and persistent deviations of exchange rates from their equilibrium values (purchasing power parity.

  18. Water Density Fluctuations Relevant to Hydrophobic Hydration are Unaltered by Attractions

    Remsing, Richard C

    2014-01-01

    An understanding of density fluctuations in bulk water has made significant contributions to our understanding of the hydration and interactions of idealized, purely repulsive hydrophobic solutes. To similarly inform the hydration of realistic hydrophobic solutes that have dispersive interactions with water, here we characterize water density fluctuations in the presence of attractive fields that correspond to solute-water attractions. We find that when the attractive field acts only in the solute hydration shell, but not in the solute core, it does not significantly alter water density fluctuations in the solute core region. We further find that for a wide range of solute sizes and attraction strengths, the free energetics of turning on the attractive fields in bulk water are accurately captured by linear response theory. Our results also suggest strategies for more efficiently estimating hydration free energies of realistic solutes in bulk water and at interfaces.

  19. Multifractal Solar EUV Intensity Fluctuations and their Implications for Coronal Heating Models

    Cadavid, A. C.; Rivera, Y. J.; Lawrence, J. K.; Christian, D. J.; Jennings, P. J.; Rappazzo, A. F.

    2016-11-01

    We investigate the scaling properties of the long-range temporal evolution and intermittency of Atmospheric Imaging Assembly/Solar Dynamics Observatory intensity observations in four solar environments: an active region core, a weak emission region, and two core loops. We use two approaches: the probability distribution function (PDF) of time series increments and multifractal detrended fluctuation analysis (MF-DFA). Noise taints the results, so we focus on the 171 Å waveband, which has the highest signal-to-noise ratio. The lags between pairs of wavebands distinguish between coronal versus transition region (TR) emission. In all physical regions studied, scaling in the range of 15-45 minutes is multifractal, and the time series are anti-persistent on average. The degree of anti-correlation in the TR time series is greater than that for coronal emission. The multifractality stems from long-term correlations in the data rather than the wide distribution of intensities. Observations in the 335 Å waveband can be described in terms of a multifractal with added noise. The multiscaling of the extreme-ultraviolet data agrees qualitatively with the radiance from a phenomenological model of impulsive bursts plus noise, and also from ohmic dissipation in a reduced magnetohydrodynamic model for coronal loop heating. The parameter space must be further explored to seek quantitative agreement. Thus, the observational “signatures” obtained by the combined tests of the PDF of increments and the MF-DFA offer strong constraints that can systematically discriminate among models for coronal heating.

  20. Multifractal Solar EUV Intensity Fluctuations and their Implications for Coronal Heating Models

    Cadavid, Ana Cristina Cadavid; Lawrence, John K; Christian, Damian J; Jennings, Peter J; Rappazzo, A Franco

    2016-01-01

    We investigate the scaling properties of the long-range temporal evolution and intermittency of SDO/AIA intensity observations in four solar environments: active region core, a weak emission region, and two core loops. We use two approaches: the probability distribution function (PDF) of time series increments, and multifractal detrended fluctuation analysis (MF-DFA). Noise taints the results, so we focus on the 171 Angstrom waveband , which has the highest signal-to-noise ratio. The lags between pairs of wavebands distinguish between coronal versus transition region (TR) emission. In all physical regions studied, scaling in the range 15-45 min is multifractal, and the time series are anti-persistent on the average. The degree of anti-correlation in the TR time series is greater than for coronal emission. The multifractality stems from long term correlations in the data rather than the wide distribution of intensities. Observations in the 335 Angstrom waveband can be described in terms of a multifractal with ...

  1. An accelerating high-latitude jet in Earth’s core

    Livermore, Philip W.; Hollerbach, Rainer; Finlay, Christopher C.

    2017-01-01

    Observations of the change in Earth’s magnetic field--the secular variation--provide information about the motion of liquid metal within the core that is responsible for the magnetic field’s generation. High-resolution observations from the European Space Agency’s Swarm satellite mission show intense field change at high latitude, localized in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we show that this feature can be explained by a localized, non-axisymmetric, westward jet of 420 km width on the tangent cylinder, the cylinder of fluid within the core that is aligned with the rotation axis and tangent to the solid inner core. We find that the jet has increased in magnitude by a factor of three over the period 2000-2016 to about 40 km yr-1, and is now much stronger than typical large-scale flows inferred for the core. We suggest that the current accelerating phase may be part of a longer-term fluctuation of the jet causing both eastward and westward movement of magnetic features over historical periods, and may contribute to recent changes in torsional-wave activity and the rotation direction of the inner core.

  2. Deep Chandra study of the truncated cool core of the Ophiuchus cluster

    Werner, N; Canning, R E A; Allen, S W; King, A L; Sanders, J S; Simionescu, A; Taylor, G B; Morris, R G; Fabian, A C

    2016-01-01

    We present the results of a deep (280 ks) Chandra observation of the Ophiuchus cluster, the second-brightest galaxy cluster in the X-ray sky. The cluster hosts a truncated cool core, with a temperature increasing from kT~1 keV in the core to kT~9 keV at r~30 kpc. Beyond r~30 kpc the intra-cluster medium (ICM) appears remarkably isothermal. The core is dynamically disturbed with multiple sloshing induced cold fronts, with indications for both Rayleigh-Taylor and Kelvin-Helmholtz instabilities. The sloshing is the result of the strongly perturbed gravitational potential in the cluster core, with the central brightest cluster galaxy (BCG) being displaced southward from the global center of mass. The residual image reveals a likely subcluster south of the core at the projected distance of r~280 kpc. The cluster also harbors a likely radio phoenix, a source revived by adiabatic compression by gas motions in the ICM. Even though the Ophiuchus cluster is strongly dynamically active, the amplitude of density fluctuat...

  3. Inverse cubic law of index fluctuation distribution in Indian markets

    Pan, R K; Pan, Raj Kumar; Sinha, Sitabhra

    2006-01-01

    One of the principal statistical features characterizing the activity in financial markets is the distribution of fluctuations in market indicators such as the index. While the developed stock markets such as the New York Stock Exchange (NYSE) have been found to show heavy-tailed fluctuation distribution, there have been claims that emerging markets behave differently. Here we investigate the distribution of several indices from the Indian financial market, one of the largest emerging markets in the world. We have used both tick-by-tick data from the National Stock Exchange (NSE) and daily closing data from both NSE and Bombay Stock Exchange (BSE). We find that the cumulative distribution of index fluctuations has long tails consistent with a power law having exponent $\\alpha \\approx 3$, independent of the time-scale of observation or the market index used for the analysis. This ``inverse cubic law'' is quantitatively similar to what has been observed in developed markets, thereby providing strong evidence th...

  4. Fluctuating lake levels in humid climates: a suitable proxy of past precipitation?

    Theuerkauf, Martin; Küster, Mathias; Kaiser, Knut

    2016-04-01

    Precipitation is a fundamental climate parameter essentially in arid and semi-arid climates, but changes in precipitation may have influenced Holocene vegetation development and human occupation in humid climates as well. However, past precipitation is notoriously difficult to reconstruct because the proxies available are widely imprecise. For example, peatland proxies such as testate amoebae are suited to reconstruct wet and dry periods of the local environment but they are poorly suited to quantify precipitation. In contrast, lake levels potentially provide a closer link to the past precipitation. In our case study, isolated lakes in the Schorfheide area (NE-Germany), fed by groundwater and rain, show at present prominent water level fluctuations that are closely correlated to annual to decadal changes in precipitation. But are these lakes indeed suitable archives to reconstruct past precipitation? To answer this question we have cored two small lakes in that area (Warnitzsee, Briesensee) with water level fluctuations well above 3 m over the past 40 years. We took seven cores along two transects from the lake shore towards the centre in Lake Warnitzsee and one core near the shore in Lake Briesensee. Core lengths range from 2.5 m to 10 m. Analysis of the cores includes geochemical parameters and pollen analysis. Two cores were dated by radiocarbon ages. All cores show recurrent marked shifts in sediment composition with up to seven peat-gyttia alternations. These sediment shifts indicate that both lakes have strongly fluctuated over the Holocene, partly with a larger magnitude than today. However, whereas the modern fluctuation periods (low and high stands) occurred over years to a few decades, we so far could only detect past fluctuation periods that lasted centuries to millennia. Furthermore, the water level in Lake Warnitzsee possibly followed a long-term trend of high water levels in the early Holocene (10.500-9000 cal. BP), low water levels between 8000 and

  5. Synthesis, molecular docking and evaluation of antifungal activity of Ni(II), Co(II) and Cu(II) complexes of porphyrin core macromolecular ligand.

    Singh, Urvashi; Malla, Ali Mohammad; Bhat, Imtiyaz Ahmad; Ahmad, Ajaz; Bukhari, Mohd Nadeem; Bhat, Sneha; Anayutullah, Syed; Hashmi, Athar Adil

    2016-04-01

    Porphyrin core dendrimeric ligand (L) was synthesized by Rothemund synthetic route in which p-hydroxy benzaldehyde and pyrrole were fused together. The prepared ligand was complexed with Ni(II), Cu(II) and Co(II) ions, separately. Both the ligand and its complexes were characterized by elemental analysis and spectroscopic studies (FT-IR, UV-Vis, (1)HNMR). Square planar geometries were proposed for Cu(II), Ni(II) and Co(II) ions in cobalt, Nickel and copper complexes, respectively on the basis of UV-Vis spectroscopic data. The ligand and its complex were screened on Candida albicans (ATCC 10231), Aspergillus fumigatus (ATCC 1022), Trichophyton mentagrophytes (ATCC 9533) and Pencillium marneffei by determining MICs and inhibition zones. The activity of the ligand and its complexes was found to be in the order: CuL ˃ CoL ≈ NiL ˃ L. Detection of DNA damage at the level of the individual eukaryotic cell was observed by commet assay. Molecular docking technique was used to understand the ligand-DNA interactions. From docking experiment, we conclude that copper complex interacts more strongly than rest two.

  6. Active galactic nuclei cores in infrared-faint radio sources: Very long baseline interferometry observations using the Very Long Baseline Array

    Herzog, Andreas; Norris, Ray P; Spitler, Lee R; Deller, Adam T; Collier, Jordan D; Parker, Quentin A

    2015-01-01

    Infrared-faint radio sources (IFRS) form a new class of galaxies characterised by radio flux densities between tenths and tens of mJy and faint or absent infrared counterparts. It has been suggested that these objects are radio-loud active galactic nuclei (AGNs) at significant redshifts (z >~ 2). Whereas the high redshifts of IFRS have been recently confirmed based on spectroscopic data, the evidence for the presence of AGNs in IFRS is mainly indirect. So far, only two AGNs have been unquestionably confirmed in IFRS based on very long baseline interferometry (VLBI) observations. In this work, we test the hypothesis that IFRS contain AGNs in a large sample of sources using VLBI. We observed 57 IFRS with the Very Long Baseline Array (VLBA) down to a detection sensitivity in the sub-mJy regime and detected compact cores in 35 sources. Our VLBA detections increase the number of VLBI-detected IFRS from 2 to 37 and provide strong evidence that most - if not all - IFRS contain AGNs. We find that IFRS have a marginal...

  7. Symmetries in fluctuations far from equilibrium.

    Hurtado, Pablo I; Pérez-Espigares, Carlos; del Pozo, Jesús J; Garrido, Pedro L

    2011-05-10

    Fluctuations arise universally in nature as a reflection of the discrete microscopic world at the macroscopic level. Despite their apparent noisy origin, fluctuations encode fundamental aspects of the physics of the system at hand, crucial to understand irreversibility and nonequilibrium behavior. To sustain a given fluctuation, a system traverses a precise optimal path in phase space. Here we show that by demanding invariance of optimal paths under symmetry transformations, new and general fluctuation relations valid arbitrarily far from equilibrium are unveiled. This opens an unexplored route toward a deeper understanding of nonequilibrium physics by bringing symmetry principles to the realm of fluctuations. We illustrate this concept studying symmetries of the current distribution out of equilibrium. In particular we derive an isometric fluctuation relation that links in a strikingly simple manner the probabilities of any pair of isometric current fluctuations. This relation, which results from the time-reversibility of the dynamics, includes as a particular instance the Gallavotti-Cohen fluctuation theorem in this context but adds a completely new perspective on the high level of symmetry imposed by time-reversibility on the statistics of nonequilibrium fluctuations. The new symmetry implies remarkable hierarchies of equations for the current cumulants and the nonlinear response coefficients, going far beyond Onsager's reciprocity relations and Green-Kubo formulas. We confirm the validity of the new symmetry relation in extensive numerical simulations, and suggest that the idea of symmetry in fluctuations as invariance of optimal paths has far-reaching consequences in diverse fields.

  8. Investigation of zonal flows by using the collective scattering measurement of density fluctuations

    Shen, H. G.; Yu, Y.; Lan, T.; Li, Y. D.; Liu, A. D.; Xie, J. L.; Liu, W. D.; Yu, C. X.; Zhang, W. Y.; Ti, A.; Li, J. G.

    2015-09-01

    The poloidal {{E}r}× {{B}\\text{T}} rotation velocities in the core plasma region are studied using the instantaneous frequency method (IFM) with the density fluctuations measured by the CO2 laser collective scattering diagnostics on the HT-7 tokamak. A coherent mode is observed in the fluctuations of poloidal velocities with the mode frequency from 10 to 20 kHz. It is identified as geodesic acoustic mode (GAM) zonal flow with poloidal symmetry (m = 0) and its mode frequency coinciding with the theoretical expected GAM frequency. The nonlinear interactions are investigated by applying the envelope analysis on the density fluctuations. The results confirm that the envelope modulation in the high frequency density fluctuations only comes from the shearing by GAM. The comparison between IFM and envelope analysis is also discussed.

  9. Potato lectin activates basophils and mast cells of atopic subjects by its interaction with core chitobiose of cell-bound non-specific immunoglobulin E.

    Pramod, S N; Venkatesh, Y P; Mahesh, P A

    2007-06-01

    A major factor in non-allergic food hypersensitivity could be the interaction of dietary lectins with mast cells and basophils. Because immunoglobulin E (IgE) contains 10-12% carbohydrates, lectins can activate and degranulate these cells by cross-linking the glycans of cell-bound IgE. The present objective focuses on the effect of potato lectin (Solanum tuberosum agglutinin; STA) for its ability to release histamine from basophils in vitro and mast cells in vivo from non-atopic and atopic subjects. In this study, subjects were selected randomly based on case history and skin prick test responses with food, pollen and house dust mite extracts. Skin prick test (SPT) was performed with STA at 100 microg/ml concentration. Histamine release was performed using leucocytes from non-atopic and atopic subjects and rat peritoneal exudate cells. SPT on 110 atopic subjects using STA showed 39 subjects positive (35%); however, none showed STA-specific IgE; among 20 non-atopic subjects, none were positive by SPT. Maximal histamine release was found to be 65% in atopic subjects (n = 7) compared to 28% in non-atopic subjects (n = 5); the release was inhibited specifically by oligomers of N-acetylglucosamine and correlates well with serum total IgE levels (R(2) = 0.923). Binding of STA to N-linked glycoproteins (horseradish peroxidase, avidin and IgG) was positive by dot blot and binding assay. As potato lectin activates and degranulates both mast cells and basophils by interacting with the chitobiose core of IgE glycans, higher intake of potato may increase the clinical symptoms as a result of non-allergic food hypersensitivity in atopic subjects.

  10. Fluctuations in Cytosolic Calcium Regulate the Neuronal Malate-Aspartate NADH Shuttle

    Satrústegui, Jorgina; Bak, Lasse K

    2015-01-01

    that MAS is regulated by fluctuations in cytosolic Ca(2+) levels, and that this regulation is required to maintain a tight coupling between neuronal activity and mitochondrial respiration and oxidative phosphorylation. At cytosolic Ca(2+) fluctuations below the threshold of the mitochondrial calcium...

  11. Animal MRI Core

    Federal Laboratory Consortium — The Animal Magnetic Resonance Imaging (MRI) Core develops and optimizes MRI methods for cardiovascular imaging of mice and rats. The Core provides imaging expertise,...

  12. Late quaternary fluctuations in carbonate and carbonate ion content in the northern Indian ocean

    Naik, S.S.

    CHAPTER II RESULTS 3.1 CaCO 3 fluctuations in the quatorial region of the major world oceans: CaO 3 contet dat of ten cores colectd from the quatorial region ver the world oceans are used to reconstruct bathymetric paterns of CaO3 preservation spanig..., representig the late Wisconsi glacil maxium shows a disolution patern for the three cores whereas in MIS 3, Chapter I Results Naik S (208) PhD Thesi 36 preservation is noticed. The transiton from interglacil to glacil maxium shows a sharp depletion. In Core...

  13. X-Ray surface brightness and gas density fluctuations in the Coma cluster

    Churazov, E; Zhuravleva, I; Schekochihin, A; Parrish, I; Sunyaev, R; Forman, W; Boehringer, H; Randall, S

    2011-01-01

    X-ray surface brightness fluctuations in the core ($650 \\times 650$ kpc) region of the Coma cluster observed with XMM-Newton and Chandra are analyzed using a 2D power spectrum approach. The resulting 2D spectra are converted to 3D power spectra of gas density fluctuations. The characteristic amplitude of the volume filling density fluctuations relative to the smooth underlying density distribution varies from 7-10% on scales of $\\sim$500 kpc down to $\\sim$5% at scales $\\sim$ 30 kpc. On smaller spatial scales, projection effects smear the density fluctuations by a large factor, precluding strong limits on the fluctuations in 3D. On the largest scales probed (hundreds of kpc), the dominant contributions to the observed fluctuations most likely arise from perturbations of the gravitational potential by the two most massive galaxies in Coma, NGC4874 and NGC4889, and the low entropy gas brought to the cluster by an infalling group. Other plausible sources of density fluctuations are discussed, including turbulence...

  14. Template-free synthesis of core-shell TiO2 microspheres covered with high-energy {116}-facet-exposed N-doped nanosheets and enhanced photocatalytic activity under visible light.

    Chen, Qifeng; Ren, Baosheng; Zhao, Yubao; Xu, Xun; Ge, Heyi; Guan, Ruifang; Zhao, Jincai

    2014-12-15

    Core-shell TiO2 microspheres possess a unique structure and interesting properties, and therefore, they have received much attention. The high-energy facets of TiO2 also are being widely studied for the high photocatalytic activities they are associated with. However, the synthesis of the core-shell structure is difficult to achieve and requires multiple-steps and/or is expensive. Hydrofluoric acid (HF), which is highly corrosive, is usually used in the controlling high-energy facet production. Therefore, it is still a significant challenge to develop low-temperature, template-free, shape-controlled, and relative green self-assembly routes for the formation of core-shell-structured TiO2 microspheres with high-energy facets. Here, we report a template- and hydrofluoric acid free solvothermal self-assembly approach to synthesize core-shell TiO2 microspheres covered with high-energy {116}-facet-exposed nanosheets, an approach in which 1,4-butanediamine plays a key role in the formation of nanosheets with exposed {116} facets and the doping of nitrogen in situ. In the structure, nanoparticle aggregates and nanosheets with {116} high-energy facets exposed act as core and shell, respectively. The photocatalytic activity for degradation of 2,4,6-tribromophenol and Rhodamine B under visible irradiation and UV/Vis irradiation has been examined, and improved photocatalytic activity under visible light owing to the hierarchical core-shell structure, {116}-plane-oriented nanosheets, in situ N doping, and large surface areas has been found.

  15. Characterizing flow fluctuations with moments

    Bhalerao, Rajeev S. [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Ollitrault, Jean-Yves, E-mail: jean-yves.ollitrault@cea.fr [CNRS, URA2306, IPhT, Institut de physique théorique de Saclay, F-91191 Gif-sur-Yvette (France); Pal, Subrata [Department of Nuclear and Atomic Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India)

    2015-03-06

    We present a complete set of multiparticle correlation observables for ultrarelativistic heavy-ion collisions. These include moments of the distribution of the anisotropic flow in a single harmonic and also mixed moments, which contain the information on correlations between event planes of different harmonics. We explain how all these moments can be measured using just two symmetric subevents separated by a rapidity gap. This presents a multi-pronged probe of the physics of flow fluctuations. For instance, it allows to test the hypothesis that event-plane correlations are generated by non-linear hydrodynamic response. We illustrate the method with simulations of events in A MultiPhase Transport (AMPT) model.

  16. Characterizing flow fluctuations with moments

    Rajeev S. Bhalerao

    2015-03-01

    Full Text Available We present a complete set of multiparticle correlation observables for ultrarelativistic heavy-ion collisions. These include moments of the distribution of the anisotropic flow in a single harmonic and also mixed moments, which contain the information on correlations between event planes of different harmonics. We explain how all these moments can be measured using just two symmetric subevents separated by a rapidity gap. This presents a multi-pronged probe of the physics of flow fluctuations. For instance, it allows to test the hypothesis that event-plane correlations are generated by non-linear hydrodynamic response. We illustrate the method with simulations of events in A MultiPhase Transport (AMPT model.

  17. Fluctuations and interactions in microemulsions

    Menes, R.; Safran, S.A. [Weizmann Institute, Rehovot (Israel); Strey, R. [Max Planck Institute, Gottingen (Germany)

    1995-12-01

    We review the properties of microemulsions as described by an interfacial model which focuses upon the deformations of the surfactant monolayer separating mesoscopic water and oil domains. In some cases, the interfacial shape is well defined, resulting in a globular phase, while in others, the interface is strongly affected by thermal fluctuations, resulting in a random, sponge-like structure. In the globular phase, interactions between globules can result in phase coexistence comparable to those observed in polymeric systems. Recent experiments indicate that these interactions can result in closed-loop coexistence regions in the isothermal, concentration phase diagram. We propose a mechanism for this reentrant phase separation based on the combined effects of a shape transition and attractive interactions. Long cylindrical globules can phase separate at relatively low interglobular attractions. A transformation from elongated globules to compact spherical drops alters the balance between the entropy and the effective interglobule interactions, leading to the remixing of the globular system.

  18. Scaling Turbo Boost to a 1000 cores

    S, Ananth Narayan; Fedorova, Alexandra

    2010-01-01

    The Intel Core i7 processor code named Nehalem provides a feature named Turbo Boost which opportunistically varies the frequencies of the processor's cores. The frequency of a core is determined by core temperature, the number of active cores, the estimated power consumption, the estimated current consumption, and operating system frequency scaling requests. For a chip multi-processor(CMP) that has a small number of physical cores and a small set of performance states, deciding the Turbo Boost frequency to use on a given core might not be difficult. However, we do not know the complexity of this decision making process in the context of a large number of cores, scaling to the 100s, as predicted by researchers in the field.

  19. Characterizing price index behavior through fluctuation dynamics

    Panigrahi, Prasanta K; Banerjee, Arjun; Bahadur, Jainendra; Manimaran, P

    2012-01-01

    We study the nature of fluctuations in variety of price indices involving companies listed on the New York Stock Exchange. The fluctuations at multiple scales are extracted through the use of wavelets belonging to Daubechies basis. The fact that these basis sets satisfy vanishing moments conditions makes them ideal to extract local polynomial trends, through the low pass or `average coefficients'. Subtracting the trends from the original time series yields the fluctuations, at different scales, depending on the level of low-pass coefficients used for finding the `average behavior'. The fluctuations are then studied using wavelet based multifractal detrended fluctuation analysis to analyze their self-similar and non-statistical properties. Due to the multifractality of such time series, they deviate from Gaussian behavior in different frequency regimes. Their departure from random matrix theory predictions in such regimes is also analyzed. These deviations and non-statistical properties of the fluctuations can...

  20. Vacuum Lightcone Fluctuations in a Dielectric

    Bessa, C H G; Ford, L H; Svaiter, N F

    2014-01-01

    A model for observable effects of electromagnetic vacuum fluctuations is presented. The model involves a probe pulse which traverses a slab of nonlinear optical material with a nonzero second order polarizability. We argue that the pulse interacts with the ambient vacuum fluctuations of other modes of the quantized electric field, and these vacuum fluctuations cause variations in the flight time of the pulse through the material. The geometry of the slab of material defines a sampling function for the quantized electric field, which in turn determines that vacuum modes whose wavelengths are of the order of the thickness of the slab give the dominant contribution. Some numerical estimates are made, which indicate that fractional fluctuations in flight time of the order of $10^{-9}$ are possible in realistic situations. The model presented here is both an illustration of a physical effect of vacuum fluctuations, and an analog model for the lightcone fluctuations predicted by quantum gravity.

  1. Mast cell differentiation and activation is closely linked to expression of genes coding for the serglycin proteoglycan core protein and a distinct set of chondroitin sulfate and heparin sulfotransferases.

    Duelli, Annette; Rönnberg, Elin; Waern, Ida; Ringvall, Maria; Kolset, Svein O; Pejler, Gunnar

    2009-12-01

    Serglycin (SG) proteoglycan consists of a small core protein to which glycosaminoglycans of chondroitin sulfate or heparin type are attached. SG is crucial for maintaining mast cell (MC) granule homeostasis through promoting the storage of various basic granule constituents, where the degree of chondroitin sulfate/heparin sulfation is essential for optimal SG functionality. However, the regulation of the SG core protein expression and of the various chondroitin sulfate/heparin sulfotransferases during MC differentiation and activation are poorly understood. Here we addressed these issues and show that expression of the SG core protein, chondroitin 4-sulfotransferase (C4ST)-1, and GalNAc(4S)-6-O-sulfotransferase (GalNAc4S6ST) are closely linked to MC maturation. In contrast, the expression of chondroitin 6-sulfotransferase correlated negatively with MC maturation. The expression of N-deacetylase/N-sulfotransferase (NDST)-2, a key enzyme in heparin synthesis, also correlated strongly with MC maturation, whereas the expression of the NDST-1 isoform was approximately equal at all stages of maturation. MC activation by either calcium ionophore or IgE ligation caused an up-regulated expression of the SG core protein, C4ST-1, and GalNAc4S6ST, accompanied by increased secretion of chondroitin sulfate as shown by biosynthetic labeling experiments. In contrast, NDST-2 was down-regulated after MC activation, suggesting that MC activation modulates the nature of the glycosaminoglycan chains attached to the SG core protein. Taken together, these data show that MC maturation is associated with the expression of a distinct signature of genes involved in SG proteoglycan synthesis, and that MC activation modulates their expression.

  2. Fluctuating confinement of water in aqueous organic nanodroplets

    Wilemski, Gerald; Hrahsheh, Fawaz

    2013-03-01

    Supercooled and nano-confined water occurs frequently as nanometer-sized aqueous-organic aerosol droplets that are ubiquitous in the atmosphere and in many industrial processes. Nanodroplet structure is important because it influences droplet growth and evaporation rates, heterogeneous reaction rates, and radiative properties. We use classical molecular dynamic simulations to study the structure of ternary water-butanol-nonane nanodroplets for several temperatures and droplet sizes. We study the effects of butanol on the wetting of the water/butanol core-shell droplet by the nonane lens. At low concentrations, butanol acts as a surfactant to significantly enhance the wetability of the water droplet by nonane. At 250 K, with sufficient butanol and nonane, perfect wetting (thin film formation by nonane) occurs. Perfect wetting also occurs at higher temperatures, 270 K to 300 K, but this wetting state is progressively destabilized at higher temperature. All of the nanodroplets studied undergo distinct transitions between partial dewetting and perfect wetting states due to isothermal fluctuations in the local distribution of butanol on the surface of the water core. These fluctuations favor the wetted state at lower temperatures and the dewetted state at higher temperatures. Supported by NSF Grant CBET 1033387

  3. Quantum fluctuations of geometry in hot Universe

    Bialynicki-Birula, Iwo

    2015-01-01

    The fluctuations of spacetime geometries at finite temperature are evaluated within the linearized theory of gravity. These fluctuations are described by the probability distribution of various configurations of the gravitational field. The field configurations are described by the linearized Riemann-Weyl tensor. The probability distribution has a foam-like structure; prevailing configurations are those with the large changes of geometry at nearby points. Striking differences are found between the fluctuations of the electromagnetic field and the gravitational field.

  4. Rapidity fluctuations in the initial state

    Broniowski, Wojciech

    2016-01-01

    We analyze two-particle pseudorapidity correlations in a simple model, where strings of fluctuating length are attached to wounded nucleons.The obtained straightforward formulas allow us to understand the anatomy of the correlations, i.e., to identify the component due to the fluctuation of the number of wounded nucleons and the contribution from the string length fluctuations. Our results reproduce qualitatively and semiquantitatively the basic features of the recent correlation measurements at the LHC.

  5. Amplification and detection of single-molecule conformational fluctuation through a protein interaction network with bimodal distributions.

    Wu, Zhanghan; Elgart, Vlad; Qian, Hong; Xing, Jianhua

    2009-09-10

    A protein undergoes conformational dynamics with multiple time scales, which results in fluctuating enzyme activities. Recent studies in single-molecule enzymology have observe this "age-old" dynamic disorder phenomenon directly. However, the single-molecule technique has its limitation. To be able to observe this molecular effect with real biochemical functions in situ, we propose to couple the fluctuations in enzymatic activity to noise propagations in small protein interaction networks such as a zeroth-order ultrasensitive phosphorylation-dephosphorylation cycle. We show that enzyme fluctuations can indeed be amplified by orders of magnitude into fluctuations in the level of substrate phosphorylation, a quantity of wide interest in cellular biology. Enzyme conformational fluctuations sufficiently slower than the catalytic reaction turnover rate result in a bimodal concentration distribution of the phosphorylated substrate. In return, this network-amplified single-enzyme fluctuation can be used as a novel biochemical "reporter" for measuring single-enzyme conformational fluctuation rates.

  6. Soil microbial activities in the water-level-fluctuating zone of Three Gorges Reservoir area during discharging period%三峡水库泄水期消落带土壤微生物活性

    李飞; 张文丽; 刘菊; 夏会娟; 王建柱

    2013-01-01

    Taking the soils at different altitudes in the water-level-fluctuating zone ( WLFZ) of Xiangxi River of the Three Gorges Reservoir area as the objects, this paper studied their physico-chemical properties and microbial activities during discharging period (May-August) , aimed to reveal the variation trends of the soil quality in the WLFZ of the Three Gorges Reservoir area. With the decrease of altitude and the increase of flooding strength, the soil water content and pH value in the WLFZ increased, soil microbial biomass and microbial quotient decreased, and soil metabolic quotient ( qCO2) increased significantly. The soil qCO2 in the cyclic wetting and drying area at the altitude below 165 m was significantly higher than that the in non-inundated area at the altitude 175-185 m. At the lower altitudes of the WLFZ, soil was subjected to flooding stress, soil pH tended to become alkaline, and soil quality decreased, being not suitable for the growth of microorganisms. No significant differences were observed in the soil organic carbon (SOC) , total N, and C/N ratio at different altitudes of the WLFZ, but the coefficient of variation (CV) of the three soil parameters was relatively smaller in cyclic wetting and drying area. It was suggested that cyclic wetting and drying was the main factor affecting the distributions of soil C and N in the WLFZ. Correlation analysis showed that soil C/N ratio had a significant positive correlation with SOC, which implied that the changes of soil C/N ratio in the WLFZ of Xiangxi River were mainly determined by the SOC.%以三峡库区香溪河消落带土壤为对象,研究泄水期(5-8月)消落带不同海拔土壤理化性质及微生物活性,旨在揭示三峡库区消落带土壤质量变化趋势.结果表明:随着海拔降低、淹水强度增强,消落带土壤含水量增加,pH值上升,土壤微生物生物量和微生物熵逐渐降低,土壤代谢熵显著增加,干湿交替区165 m以下土壤代谢

  7. Glacier fluctuations during the past 2000 years

    Solomina, Olga N.; Bradley, Raymond S.; Jomelli, Vincent; Geirsdottir, Aslaug; Kaufman, Darrell S.; Koch, Johannes; McKay, Nicholas P.; Masiokas, Mariano; Miller, Gifford; Nesje, Atle; Nicolussi, Kurt; Owen, Lewis A.; Putnam, Aaron E.; Wanner, Heinz; Wiles, Gregory; Yang, Bao

    2016-10-01

    A global compilation of glacier advances and retreats for the past two millennia grouped by 17 regions (excluding Antarctica) highlights the nature of glacier fluctuations during the late Holocene. The dataset includes 275 time series of glacier fluctuations based on historical, tree ring, lake sediment, radiocarbon and terrestrial cosmogenic nuclide data. The most detailed and reliable series for individual glaciers and regional compilations are compared with summer temperature and, when available, winter precipitation reconstructions, the most important parameters for glacier mass balance. In many cases major glacier advances correlate with multi-decadal periods of decreased summer temperature. In a few cases, such as in Arctic Alaska and western Canada, some glacier advances occurred during relatively warm wet times. The timing and scale of glacier fluctuations over the past two millennia varies greatly from region to region. However, the number of glacier advances shows a clear pattern for the high, mid and low latitudes and, hence, points to common forcing factors acting at the global scale. Globally, during the first millennium CE glaciers were smaller than between the advances in 13th to early 20th centuries CE. The precise extent of glacier retreat in the first millennium is not well defined; however, the most conservative estimates indicate that during the 1st and 2nd centuries in some regions glaciers were smaller than at the end of 20th/early 21st centuries. Other periods of glacier retreat are identified regionally during the 5th and 8th centuries in the European Alps, in the 3rd-6th and 9th centuries in Norway, during the 10th-13th centuries in southern Alaska, and in the 18th century in Spitsbergen. However, no single period of common global glacier retreat of centennial duration, except for the past century, has yet been identified. In contrast, the view that the Little Ice Age was a period of global glacier expansion beginning in the 13th century

  8. Local Multiplicity Fluctuations in Z decay

    Chekanov, S. V.

    1996-01-01

    Local multiplicity fluctuations of hadrons produced in the decay of $Z^0$ were studied on the basis of L3 data. In addition to the normalized-factorial-moment method, the fluctuations were studied for the first time by the use of bunching parameters. A strong multifractal structure was observed inside jets. JETSET 7.4 PS describes the fluctuations in the azimuthal angle defined with respect to the beam axis reasonably well. For the fluctuations in rapidity, defined with respect to the thrust ...

  9. Synthesis of beta-cyclodextrin-modified water-dispersible Ag-TiO2 core-shell nanoparticles and their photocatalytic activity.

    Shown, Indrajit; Ujihara, Masaki; Imae, Toyoko

    2011-04-01

    The beta-cyclodextrin-modified Ag-TiO2 core-shell nanoparticles were prepared by sodium borohydrate reduction of AgNO3 and the subsequent hydrolysis of the tetraisopropyl orthotitanate in an aqueous medium. Inversely in the preparation of beta-cyclodextrin-modified TiO2-Ag core-shell nanoparticles, first hydrolysis and then following reduction were carried out. The synthesized spherical core-shell nanoparticles were highly water-dispersible and had an average diameter in the range of 9 to 12 nm. A significant shifting of surface plasmon band was observed for the synthesized Ag-TiO2 and TiO2-Ag core-shell nanoparticles. On a model reaction, namely, the photodegradation of phenol by the UV light irradiation, the photocatalytic property of TiO2 nanoparticles was enhanced, when the Ag nanoparticle was embedded in the core of TiO2 nanoparticles but TiO2 nanoparticles coated by Ag shell decreased the photocatalytic property of TiO2 nanoparticles. The mechanism is ascribed to the surface plasmon characteristics of Ag in the core of the TiO2 nanoparticles under the acceleration by host-guest inclusion characteristics.

  10. Active galactic nuclei cores in infrared-faint radio sources. Very long baseline interferometry observations using the Very Long Baseline Array

    Herzog, A.; Middelberg, E.; Norris, R. P.; Spitler, L. R.; Deller, A. T.; Collier, J. D.; Parker, Q. A.

    2015-06-01

    Context. Infrared-faint radio sources (IFRS) form a new class of galaxies characterised by radio flux densities between tenths and tens of mJy and faint or absent infrared counterparts. It has been suggested that these objects are radio-loud active galactic nuclei (AGNs) at significant redshifts (z ≳ 2). Aims: Whereas the high redshifts of IFRS have been recently confirmed based on spectroscopic data, the evidence for the presence of AGNs in IFRS is mainly indirect. So far, only two AGNs have been unquestionably confirmed in IFRS based on very long baseline interferometry (VLBI) observations. In this work, we test the hypothesis that IFRS contain AGNs in a large sample of sources using VLBI. Methods: We observed 57 IFRS with the Very Long Baseline Array (VLBA) down to a detection sensitivity in the sub-mJy regime and detected compact cores in 35 sources. Results: Our VLBA detections increase the number of VLBI-detected IFRS from 2 to 37 and provide strong evidence that most - if not all - IFRS contain AGNs. We find that IFRS have a marginally higher VLBI detection fraction than randomly selected sources with mJy flux densities at arcsec-scales. Moreover, our data provide a positive correlation between compactness - defined as the ratio of milliarcsec- to arcsec-scale flux density - and redshift for IFRS, but suggest a decreasing mean compactness with increasing arcsec-scale radio flux density. Based on these findings, we suggest that IFRS tend to contain young AGNs whose jets have not formed yet or have not expanded, equivalent to very compact objects. We found two IFRS that are resolved into two components. The two components are spatially separated by a few hundred milliarcseconds in both cases. They might be components of one AGN, a binary black hole, or the result of gravitational lensing.

  11. Hydroxyapatite Nanowires@Metal-Organic Framework Core/Shell Nanofibers: Templated Synthesis, Peroxidase-Like Activity, and Derived Flexible Recyclable Test Paper.

    Chen, Fei-Fei; Zhu, Ying-Jie; Xiong, Zhi-Chao; Sun, Tuan-Wei

    2017-03-08

    The templated synthesis of hydroxyapatite (HAP) nanowires@metal-organic framework (MOF) core/shell nanofibers (named HAP@MIL-100(Fe) nanofibers) is demonstrated. The ultralong hydroxyapatite nanowires are adopted as a hard template for the nucleation and growth of MIL-100(Fe) (a typical MOF) through the layer-by-layer method. The Coulombic and chelation interactions between Ca(2+) ions on the surface of the HAP nanowires and the COO(-) organic linkers of MIL-100(Fe) play key roles in the formation process. The as-prepared, water-stable HAP@MIL-100(Fe) nanofibers exhibit peroxidase-like activity toward the oxidation of different peroxidase substrates in the presence of H2 O2 , accompanied by a clear color change of the solution. Furthermore, a flexible, recyclable HAP@MIL-100(Fe) test paper is prepared successfully by using HAP@MIL-100(Fe) nanofibers as building blocks. A simple, low-cost, and sensitive colorimetric method for the detection of H2 O2 and glucose is established based on the as-prepared, flexible, recyclable HAP@MIL-100(Fe) test paper. More importantly, the HAP@MIL-100(Fe) test paper can be recovered easily for reuse by simply dipping in absolute ethanol for just 30 min, thus showing excellent recyclability. With its combination of advantages such as easy transportation, easy storage and use, rapid recyclability, light weight, and high flexibility, this HAP@MIL-100(Fe) test paper is promising for wide applications in various fields.

  12. From motor-induced fluctuations to mesoscopic dynamics in epithelial tissues

    Fodor, É; Comelles, J; Thiagarajan, R; Gov, N S; Visco, P; van Wijland, F; Riveline, D

    2015-01-01

    Molecular motors power spatial fluctuations in epithelial tissues. We evaluate these fluctuations in MDCK monolayers by tracking tricellular junctions, leading us to highlight the non-Gaussian statistics of the junction displacement. Using a mesoscopic framework which separates the thermal fluctuations orig- inating from the heat bath and the athermal ones generated by the motors, we quantify key parameters of the junction activity such as diffusion coefficient, persistence time and persistence length. When inhibiting specific targets in the molecular pathway which regulates the motors, we report subsequent modifications of these parameters: the hierarchy in the molecular pathway is correlated to the active fluctuations driving the junction dynamics. Our study provides a framework for quantifying nonequilibrium fluctuations in living matter with potential relevance for physiological shape transformations in the developing embryos.

  13. Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks

    Kachan, Devin Michael

    Fluctuation-induced interactions are an important organizing principle in a variety of soft matter systems. In this dissertation, I explore the role of both thermal and active fluctuations within cross-linked polymer networks. The systems I study are in large part inspired by the amazing physics found within the cytoskeleton of eukaryotic cells. I first predict and verify the existence of a thermal Casimir force between cross-linkers bound to a semi-flexible polymer. The calculation is complicated by the appearance of second order derivatives in the bending Hamiltonian for such polymers, which requires a careful evaluation of the the path integral formulation of the partition function in order to arrive at the physically correct continuum limit and properly address ultraviolet divergences. I find that cross linkers interact along a filament with an attractive logarithmic potential proportional to thermal energy. The proportionality constant depends on whether and how the cross linkers constrain the relative angle between the two filaments to which they are bound. The interaction has important implications for the synthesis of biopolymer bundles within cells. I model the cross-linkers as existing in two phases: bound to the bundle and free in solution. When the cross-linkers are bound, they behave as a one-dimensional gas of particles interacting with the Casimir force, while the free phase is a simple ideal gas. Demanding equilibrium between the two phases, I find a discontinuous transition between a sparsely and a densely bound bundle. This discontinuous condensation transition induced by the long-ranged nature of the Casimir interaction allows for a similarly abrupt structural transition in semiflexible filament networks between a low cross linker density isotropic phase and a higher cross link density bundle network. This work is supported by the results of finite element Brownian dynamics simulations of semiflexible filaments and transient cross-linkers. I

  14. Altered Daytime Fluctuation Pattern of Plasminogen Activator Inhibitor 1 in Type 2 Diabetes Patients with Coronary Artery Disease: A Strong Association with Persistently Elevated Plasma Insulin, Increased Insulin Resistance, and Abdominal Obesity

    Katarina Lalić

    2015-01-01

    Full Text Available This study was aimed at investigating daily fluctuation of PAI-1 levels in relation to insulin resistance (IR and daily profile of plasma insulin and glucose levels in 26 type 2 diabetic (T2D patients with coronary artery disease (CAD (group A, 10 T2D patients without CAD (group B, 12 nondiabetics with CAD (group C, and 12 healthy controls (group D. The percentage of PAI-1 decrease was lower in group A versus group B (4.4 ± 2.7 versus 35.0 ± 5.4%; P<0.05 and in C versus D (14.0 ± 5.8 versus 44.7 ± 3.1%; P<0.001. HOMA-IR was higher in group A versus group B (P<0.05 and in C versus D (P<0.01. Simultaneously, AUCs of PAI-1 and insulin were higher in group A versus group B (P<0.05 and in C versus D (P<0.01, while AUC of glucose did not differ between groups. In multiple regression analysis waist-to-hip ratio and AUC of insulin were independent determinants of decrease in PAI-1. The altered diurnal fluctuation of PAI-1, especially in T2D with CAD, might be strongly influenced by a prolonged exposure to hyperinsulinemia in the settings of increased IR and abdominal obesity, facilitating altogether an accelerated atherosclerosis.

  15. Inverse scattering problem in turbulent magnetic fluctuations

    Treumann, R A; Narita, Y

    2016-01-01

    We apply a particular form of the inverse scattering theory to turbulent magnetic fluctuations in a plasma. In the present note we develop the theory, formulate the magnetic fluctuation problem in terms of its electrodynamic turbulent response function, and reduce it to the solution of a special form of the famous Gel$'$fand-Levitan-Marchenko equation of quantum mechanical scattering theory.

  16. Wave Beam Propagation Through Density Fluctuations

    Balakin, A. A.; Bertelli, N.; Westerhof, E.

    2011-01-01

    Perturbations induced by edge density fluctuations on electron cyclotron wave beams propagating in fusion plasmas are studied by means of a quasi-optical code. The effects of such fluctuations are illustrated here by showing the beam propagation in the case of single harmonic perturbations to the wa

  17. Computer simulations of phospholipid - membrane thermodynamic fluctuations

    Pedersen, U.R.; Peters, Günther H.j.; Schröder, T.B.;

    2008-01-01

    This paper reports all-atom computer simulations of five phospholipid membranes, DMPC, DPPC, DMPG, DMPS, and DMPSH, with a focus on the thermal equilibrium fluctuations of volume, energy, area, thickness, and order parameter. For the slow fluctuations at constant temperature and pressure (defined...

  18. The Spectrum of Wind Power Fluctuations

    Bandi, Mahesh

    2016-11-01

    Wind is a variable energy source whose fluctuations threaten electrical grid stability and complicate dynamical load balancing. The power generated by a wind turbine fluctuates due to the variable wind speed that blows past the turbine. Indeed, the spectrum of wind power fluctuations is widely believed to reflect the Kolmogorov spectrum; both vary with frequency f as f - 5 / 3. This variability decreases when aggregate power fluctuations from geographically distributed wind farms are averaged at the grid via a mechanism known as geographic smoothing. Neither the f - 5 / 3 wind power fluctuation spectrum nor the mechanism of geographic smoothing are understood. In this work, we explain the wind power fluctuation spectrum from the turbine through grid scales. The f - 5 / 3 wind power fluctuation spectrum results from the largest length scales of atmospheric turbulence of order 200 km influencing the small scales where individual turbines operate. This long-range influence spatially couples geographically distributed wind farms and synchronizes farm outputs over a range of frequencies and decreases with increasing inter-farm distance. Consequently, aggregate grid-scale power fluctuations remain correlated, and are smoothed until they reach a limiting f - 7 / 3 spectrum. This work was funded by the Collective Interactions Unit, OIST Graduate University, Japan.

  19. Charge conservation effects for high order fluctuations

    Begun, Viktor

    2016-01-01

    The exact charge conservation significantly impacts multiplicity fluctuations. The result depends strongly on the part of the system charge carried by the particles of interest. Along with the expected suppression of fluctuations for large systems, charge conservation may lead to negative skewness or kurtosis for small systems.

  20. Fluctuating brane in a dilatonic bulk

    Brax, P; Rodríguez-Martinez, M; Brax, Philippe; Langlois, David; Rodriguez-Martinez, Maria

    2003-01-01

    We consider a cosmological brane moving in a static five-dimensional bulk spacetime endowed with a scalar field whose potential is exponential. After studying various cosmological behaviours for the homogeneous background, we investigate the fluctuations of the brane that leave spacetime unaffected. A single mode embodies these fluctuations and obeys a wave equation which we study for bouncing and ever-expanding branes.

  1. Fluctuations of a fluid inside a pore

    Zvelindovsky, AV; Zatovsky, AV

    1997-01-01

    The correlation theory of the thermal hydrodynamic fluctuations of compressible viscous fluids within a spherical pore has been developed. The fluctuation motions ape described by the linearized Navier-Stokes and heat transfer equations, containing spontaneous viscous stresses and heat fluxes. The e

  2. Hybrid Analysis of Engine Core Noise

    O'Brien, Jeffrey; Kim, Jeonglae; Ihme, Matthias

    2015-11-01

    Core noise, or the noise generated within an aircraft engine, is becoming an increasing concern for the aviation industry as other noise sources are progressively reduced. The prediction of core noise generation and propagation is especially challenging for computationalists since it involves extensive multiphysics including chemical reaction and moving blades in addition to the aerothermochemical effects of heated jets. In this work, a representative engine flow path is constructed using experimentally verified geometries to simulate the physics of core noise. A combustor, single-stage turbine, nozzle and jet are modeled in separate calculations using appropriate high fidelity techniques including LES, actuator disk theory and Ffowcs-Williams Hawkings surfaces. A one way coupling procedure is developed for passing fluctuations downstream through the flowpath. This method effectively isolates the core noise from other acoustic sources, enables straightforward study of the interaction between core noise and jet exhaust, and allows for simple distinction between direct and indirect noise. The impact of core noise on the farfield jet acoustics is studied extensively and the relative efficiency of different disturbance types and shapes is examined in detail.

  3. Homeostatic fluctuations of a tissue surface

    Risler, Thomas; Prost, Jacques

    2015-01-01

    We study the surface fluctuations of a tissue with a dynamics dictated by cell-rearrangement, cell-division and cell-death processes. Surface fluctuations are calculated in the homeostatic state, where cell division and cell death equilibrate on average. The obtained fluctuation spectrum can be mapped onto several other spectra such as those characterizing incompressible fluids, compressible Maxwell elastomers or permeable membranes in appropriate asymptotic regimes. Since cell division and cell death are out-of-equilibrium processes, detailed balance is broken, but a generalized fluctuation-response relation is satisfied in terms of appropriate observables. Our work is a first step toward the description of the out-of-equilibrium fluctuations of the surface of a thick epithelium and its dynamical response to external perturbations.

  4. Fluctuations in lipid bilayers: Are they understood?

    Schmid, Friederike

    2013-01-01

    We review recent computer simulation studies of undulating lipid bilayers. Theoretical interpretations of such fluctuating membranes are most commonly based on generalized Helfrich-type elastic models, with additional contributions of local "protrusions" and/or density fluctuations. Such models provide an excellent basis for describing the fluctuations of tensionless bilayers in the fluid phase at a quantitative level. However, this description is found to fail for membranes in the gel phase and for membranes subject to high tensions. The fluctuations of tilted gel membranes show a signature of the modulated ripple structure, which is a nearby phase observed in the pretransition regime between the fluid and tilted gel state. This complicates a quantitative analysis on mesoscopic length scales. In the case of fluid membranes under tension, the large-wavelength fluctuation modes are found to be significantly softer than predicted by theory. In the latter context, we also address the general problem of the relat...

  5. Net Charge Fluctuation and String Fragmentation

    SABen-Hao; CAIXu; TAIAn; ZHOUDai-Mei

    2004-01-01

    We present the simulation results of the net charge fluctuation in Au+Au collisions at √Snn=130 GeV from a dynamic model, JPCIAE, and its revisions. The simulations are done for the quark-gluon matter, the directly produced pions, the pion matter, and the hadron matter. The simulated net charge fluctuation of the quark-gluon matter is close to the thermal model prediction for the quark-gluon gas. However, the discrepancy exists comparing the simulated net charge fluctuation for directly produced pions and the pion matter with the thermal model prediction for pion gas and the resonance pion gas, respectively. The net charge fluctuation of hadron matter from default JPCIAE simulations is nearly 3.5 times larger than quark-gluon matter. A discussion is given for the net charge fluctuation as an evidence of QGP phase transition.

  6. Correlated fluctuations near the QCD critical point

    Jiang, Lijia; Song, Huichao

    2015-01-01

    In this paper, we introduce a freeze-out scheme for the dynamical models near the QCD critical point through coupling the decoupled classical particles with the order parameter field. With a modified distribution function that satisfies specific static fluctuations, we calculate the correlated fluctuations of net protons on the hydrodynamic freeze-out surface. A comparison with recent STAR data shows that our model calculations could roughly reproduce energy dependent cumulant $C_4$ and $\\kappa \\sigma^2$ of net protons through tuning the related parameters. However, the calculated $C_2$ and $C_3$ with both Poisson and Binomial baselines are always above the experimental data due to the positive contributions from the static critical fluctuations. In order to qualitatively and quantitatively describe the experimental data, the dynamical critical fluctuations and more realistic non-critical fluctuation baselines should be investigated in the near future.

  7. Solar wind thermally induced magnetic fluctuations.

    Navarro, R E; Moya, P S; Muñoz, V; Araneda, J A; F-Viñas, A; Valdivia, J A

    2014-06-20

    A kinetic description of Alfvén-cyclotron magnetic fluctuations for anisotropic electron-proton quasistable plasmas is studied. An analytical treatment, based on the fluctuation-dissipation theorem, consistently shows that spontaneous fluctuations in plasmas with stable distributions significantly contribute to the observed magnetic fluctuations in the solar wind, as seen, for example, in [S. D. Bale et al., Phys. Rev. Lett. 103, 211101 (2009)], even far below from the instability thresholds. Furthermore, these results, which do not require any adjustable parameters or wave excitations, are consistent with the results provided by hybrid simulations. It is expected that this analysis contributes to our understanding of the nature of magnetic fluctuations in the solar wind.

  8. Fluctuation theorem for constrained equilibrium systems

    Gilbert, Thomas; Dorfman, J. Robert

    2006-02-01

    We discuss the fluctuation properties of equilibrium chaotic systems with constraints such as isokinetic and Nosé-Hoover thermostats. Although the dynamics of these systems does not typically preserve phase-space volumes, the average phase-space contraction rate vanishes, so that the stationary states are smooth. Nevertheless, finite-time averages of the phase-space contraction rate have nontrivial fluctuations which we show satisfy a simple version of the Gallavotti-Cohen fluctuation theorem, complementary to the usual fluctuation theorem for nonequilibrium stationary states and appropriate to constrained equilibrium states. Moreover, we show that these fluctuations are distributed according to a Gaussian curve for long enough times. Three different systems are considered here: namely, (i) a fluid composed of particles interacting with Lennard-Jones potentials, (ii) a harmonic oscillator with Nosé-Hoover thermostatting, and (iii) a simple hyperbolic two-dimensional map.

  9. Correlated fluctuations near the QCD critical point

    Jiang, Lijia; Li, Pengfei; Song, Huichao

    2016-08-01

    In this article, we introduce a freeze-out scheme for the dynamical models near the QCD critical point through coupling the decoupled classical particles with the order parameter field. With a modified distribution function that satisfies specific static fluctuations, we calculate the correlated fluctuations of net protons on the hydrodynamic freeze-out surface. A comparison with recent STAR data shows that our model calculations could roughly reproduce energy-dependent cumulant C4 and κ σ2 of net protons through tuning the related parameters. However, the calculated C2 and C3 with both Poisson and binomial baselines are always above the experimental data due to the positive contributions from the static critical fluctuations. To qualitatively and quantitatively describe all the related experimental data, the dynamical critical fluctuations and more realistic noncritical fluctuation baselines should be investigated in the near future.

  10. Coupled Quantum Fluctuations and Quantum Annealing

    Hormozi, Layla; Kerman, Jamie

    We study the relative effectiveness of coupled quantum fluctuations, compared to single spin fluctuations, in the performance of quantum annealing. We focus on problem Hamiltonians resembling the the Sherrington-Kirkpatrick model of Ising spin glass and compare the effectiveness of different types of fluctuations by numerically calculating the relative success probabilities and residual energies in fully-connected spin systems. We find that for a small class of instances coupled fluctuations can provide improvement over single spin fluctuations and analyze the properties of the corresponding class. Disclaimer: This research was funded by ODNI, IARPA via MIT Lincoln Laboratory under Air Force Contract No. FA8721-05-C-0002. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of ODNI, IARPA, or the US Government.

  11. Core-size-dependent catalytic properties of bimetallic Au/Ag core-shell nanoparticles.

    Haldar, Krishna Kanta; Kundu, Simanta; Patra, Amitava

    2014-12-24

    Bimetallic core-shell nanoparticles have recently emerged as a new class of functional materials because of their potential applications in catalysis, surface enhanced Raman scattering (SERS) substrate and photonics etc. Here, we have synthesized Au/Ag bimetallic core-shell nanoparticles with varying the core diameter. The red-shifting of the both plasmonic peaks of Ag and Au confirms the core-shell structure of the nanoparticles. Transmission electron microscopy (TEM) analysis, line scan EDS measurement and UV-vis study confirm the formation of core-shell nanoparticles. We have examined the catalytic activity of these core-shell nanostructures in the reaction between 4-nitrophenol (4-NP) and NaBH4 to form 4-aminophenol (4-AP) and the efficiency of the catalytic reaction is found to be increased with increasing the core size of Au/Ag core-shell nanocrystals. The catalytic efficiency varies from 41.8 to 96.5% with varying core size from 10 to 100 nm of Au/Ag core-shell nanoparticles, and the Au100/Ag bimetallic core-shell nanoparticle is found to be 12-fold more active than that of the pure Au nanoparticles with 100 nm diameter. Thus, the catalytic properties of the metal nanoparticles are significantly enhanced because of the Au/Ag core-shell structure, and the rate is dependent on the size of the core of the nanoparticles.

  12. k-core covers and the core

    Sanchez-Rodriguez, E.; Borm, Peter; Estevez-Fernandez, A.; Fiestras-Janeiro, G.; Mosquera, M.A.

    2015-01-01

    This paper extends the notion of individual minimal rights for a transferable utility game (TU-game) to coalitional minimal rights using minimal balanced families of a specific type, thus defining a corresponding minimal rights game. It is shown that the core of a TU-game coincides with the core of

  13. Academic Rigor: The Core of the Core

    Brunner, Judy

    2013-01-01

    Some educators see the Common Core State Standards as reason for stress, most recognize the positive possibilities associated with them and are willing to make the professional commitment to implementing them so that academic rigor for all students will increase. But business leaders, parents, and the authors of the Common Core are not the only…

  14. Fluctuations in work motivation: tasks do not matter!

    Navarro, Jose; Curioso, Fernando; Gomes, Duarte; Arrieta, Carlos; Cortes, Mauricio

    2013-01-01

    Previous studies have shown that work motivation fluctuates considerably and in a nonlinear way over time. In the present research, we are interested in studying if the task at hand does or does not influence the presence of these fluctuations. We gathered daily registers from 69 workers during 21 consecutive working days (7036 registers) of task developed and levels of motivation, self-efficacy beliefs and instrumentalities perception. These registers were then categorized into a list of labor activities in main tasks and subtasks by means of three judges with a high level of agreement (97.47% for tasks, and 98.64% for subtasks). Taking the MSSD statistic (mean squared successive difference) of the average of motivation, self-efficacy and instrumentality, and using hierarchical regression analysis we have found that tasks (beta = .03; p = .188) and subtasks (beta = .10; p = .268) do not affect the presence of fluctuations in motivation. These results reveal instability in work motivation independently from the tasks and subtasks that the workers do. We proceed to find that fluctuations in work motivation show a fractal structure across the different tasks we do in a working day. Implications of these results to motivational theory will be discussed as well as possible explanations (e.g. the influence of affect in work motivation) and directions for future research are provided.

  15. Fluctuations in airport arrival and departure traffic: A network analysis

    Li Shan-Mei; Xu Xiao-Hao; Meng Ling-Hang

    2012-01-01

    Air traffic is a typical complex system,in which movements of traffic components (pilots,controllers,equipment,and environment),especially airport arrival and departure traffic,form complicated spatial and temporal dynamics.The fluctuations of airport arrival and departure traffic are studied from the point of view of networks as the special correlation between different airports.Our collected flow volume data on the time-dependent activity of US airport arrival and departure traffic indicate that the coupling between the average flux and the fluctuation of an individual airport obeys a certain scaling law with a wide variety of scaling exponents between 1/2 and 1.These scaling phenomena can explain the interaction between the airport internal dynamics (e.g.queuing at airports,a ground delay program and following flying traffic) and a change in the external (network-wide) traffic demand (e.g.an increase in traffic during peak hours every day),allowing us to further understand the mechanisms governing the collective behaviour of the transportation system.We separate internal dynamics from external fluctuations using a scaling law which is helpful for us to systematically determine the origin of fluctuations in airport arrival and departure traffic,uncovering the collective dynamics.Hot spot features are observed in airport traffic data as the dynamical inhomogeneity in the fluxes of individual airports.The intrinsic characteristics of airport arrival and departure traffic under severe weather is discussed as well.

  16. Redistribution of phase fluctuations in a periodically driven cuprate superconductor

    Hoeppner, Robert; Zhu, Beilei; Rexin, Tobias [Zentrum fuer Optische Quantentechnologien und Institut fuer Laserphysik, Hamburg (Germany); Mathey, Ludwig [Zentrum fuer Optische Quantentechnologien und Institut fuer Laserphysik, Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Hamburg (Germany); Cavalleri, Andrea [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); Department of Physics, Oxford University, Clarendon Laboratory, Parks Road, Oxford (United Kingdom)

    2015-07-01

    We study the thermally fluctuating state of a bi-layer cuprate superconductor under the periodic action of a staggered field oscillating at optical frequencies. This analysis distills essential elements of the recently discovered phenomenon of light enhanced coherence in YBCO, which was achieved by periodically driving infrared active apical oxygen distortions. The effect of a staggered periodic perturbation is studied using a Langevin description of driven, coupled Josephson junctions, which represent two neighboring pairs of layers and their two plasmons. We demonstrate that the external driving leads to a suppression of phase fluctuations of the low-energy plasmon, an effect which is amplified via the resonance of the high energy plasmon, with a striking suppression of the low-energy fluctuations, as visible in the power spectrum. We also find that this effect acts onto the in-plane fluctuations, which are reduced on long length scales and we discuss the behavior of vortices in the ab-planes and across the weakly coupled junctions.

  17. Measurement of the internal magnetic fluctuation by the transport of runaways on J-TEXT

    Chen, Z. Y.; Huang, D. W.; Tong, R. H.; Yan, W.; Wei, Y. N.; Ma, T. K.; Jiang, Z. H.; Zhang, X. Q.; Chen, Z. P.; Yang, Z. J.; Zhuang, G.

    2016-11-01

    The measurement of internal magnetic fluctuation is important for the study of transport in tokamak plasmas. The runaway electron transport induced by the sawtooth crash can be used to obtain the internal magnetic fluctuation. Inversed sawtooth-like activities on hard x-ray (HXR) fluxes following sawtooth activities were observed after the application of electrode biasing on J-TEXT tokamak. The runaway diffusion coefficient Dr is deduced to be about 30 m2/s according to the time delay of HXR flux peaks to the sawtooth crashes. The averaged value of normalized magnetic fluctuation in the discharges with electrode biasing was increased to the order of 1 × 10-4.

  18. Dominant length scale of the ``pure'' turbulent fluctuations in the outer region of wall turbulence

    Kwon, Yong Seok; Monty, Jason; Hutchins, Nick

    2014-11-01

    A new method of decomposing the total velocity in boundary layers, which removes the influence of instantaneous boundary layer thickness variations to the fluctuating velocity component, is proposed. The recent proposition of the quiescent core of turbulent channel flow by Kwon et al. (J. Fluid Mech., 751, 228 (2014)) permits us to apply the same decomposition to channel flows where the quiescent core is analogous to the free-stream. Using this decomposition, it is observed that the majority of the large-scale streamwise velocity fluctuation within the intermittent region is attributed to the oscillation of the turbulent/non-turbulent interface or the quiescent core. It suggests that the quiescent core and the free-stream play a similar role and the flow nearer to the wall in both flows is more similar than previously thought while the different characteristics of the free-stream and the quiescent core account for the differences in the outer region of two flows. These findings re-affirm the analogy between the quiescent core and the free-stream, which could potentially lead to the unified conceptual model between internal and external flows. This work is financially supported by the Australian Research Council and the Defence Science and Technology Organisation.

  19. Vegetation changes and timberline fluctuations in the Central Alps as indicators of holocene climatic oscillations

    Wick, L.; Tinner, W. [Univ. of Bern (Switzerland)

    1997-11-01

    Pollen and plant-macrofossil data are presented for two lakes near the timberline in the Italian (Lago Basso, 2250 m) and Swiss Central Alps (Gouille Rion, 2343 m). The reforestation at both sites started at 9700-9500 BP with Pinus cembra, Larix decidua, and Betula. The timberline reached its highest elevation between 8700 and 5000 BP and retreated after 5000 BP, due to a mid-Holocene climatic change and increasing human impact since about 3500 BP (Bronze Age). The expansion of Picea abies at Lago Basso between ca. 7500 and 6200 BP was probably favored by cold phases accompanied by increased oceanicity, whereas in the area of Gouille Rion, where spruce expanded rather late (between 4500 and 3500 BP), human influence equality might have been important. The mass expansion of Alnus viridis between ca. 5000 and 3500 BP probably can be related to both climatic change and human activity at timberline. During the early and middle Holocene a series of timberline fluctuations is recorded as declines in pollen and macrofossil concentrations of the major tree species, and as increases in nonarboreal pollen in the pollen percentage diagram of Gouille Rion. Most of the periods of low timberline can be correlated by radiocarbon dating the climatic changes in the Alps as indicated by glacier advances in combination with palynological records, solifluction, and dendroclimatical data. Lago Basso and Gouille Rion are the only sites in the Alps showing complete palaeobotanical records of cold phases between 10,000 and 2000 BP with very good time control. The altitudinal range of the Holocene treeline fluctuations caused by climate most likely was not more than 100 to 150 m. A possible correlation of a cold period at ca. 7500-6500 BP (Misox oscillation) in the Alps is made with paleoecological data from North American and Scandinavia and a climate signal in the GRIP ice core from central Greenland 8200 yr ago (ca. 7400 yr uncal. BP).

  20. Latest Pleistocene and Holocene glacier fluctuations on Mount Baker, Washington

    Osborn, Gerald; Menounos, Brian; Ryane, Chanone; Riedel, Jon; Clague, John J.; Koch, Johannes; Clark, Douglas; Scott, Kevin; Davis, P. Thompson

    2012-08-01

    Glaciers on stratovolcanoes of the Pacific Northwest of North America offer opportunities for dating late Pleistocene and Holocene glacier advances because tephra and fossil wood are common in lateral moraines and in glacier forefields. We capitalize on this opportunity by examining the Holocene glacial record at Mount Baker, an active stratovolcano in northwest Washington. Earlier workers concluded that glaciers on Mount Baker during the early Holocene were more extensive than during the Little Ice Age and hypothesized that the explanation lay in unusual climatic or hypsometric effects peculiar to large volcanoes. We show that the main argument for an early Holocene glacier advance on Mount Baker, namely the absence of ca 10,000-year-old tephra on part of the south flank of the mountain, is incorrect. Moreover, a lake-sediment core indicates that a small cirque moraine previously thought be of early Holocene age is also likely older than the tephra and consequently of late Pleistocene age. Lateral and end moraines and wood mats ca 2 km downvalley of the present snout of Deming Glacier indicate that an advance during the Younger Dryas interval was little more extensive than the climactic Little Ice Age advance. Tephra and wood between tills in the left lateral moraine of Easton Glacier suggest that ice on Mount Baker was restricted in the early Holocene and that Neoglaciation began ca 6 ka. A series of progressively more extensive Neoglacial advances, dated to about 2.2, 1.6, 0.9, and 0.4 ka, are recorded by stacked tills in the right lateral moraine of Deming Glacier. Intervening retreats were long enough to allow establishment of forests on the moraine. Wood mats in moraines of Coleman and Easton glaciers indicate that Little Ice Age expansion began before 0.7 ka and was followed by retreat and a readvance ca 0.5 ka. Tree-ring and lichen data indicate glaciers on the south side of the mountain reached their maximum extents in the mid-1800s. The similarity between

  1. Prediction of propeller-induced hull-pressure fluctuations

    Van Wijngaarden, H.C.J.

    2011-01-01

    The cavitating propeller often forms the primary source of noise and vibration on board ships. The propeller induces hydroacoustic pressure fluctuations due to the passing blades and, more importantly, the dynamic activity of cavities in the propeller’s immediate vicinity. The accurate prediction of the resulting vibratory hull-excitation forces is indispensible in the ship design process, but is not always warranted. From this follows the main objective of the thesis, which is the developmen...

  2. Ongoing Slow Fluctuations in V1 Impact on Visual Perception.

    Wohlschläger, Afra M; Glim, Sarah; Shao, Junming; Draheim, Johanna; Köhler, Lina; Lourenço, Susana; Riedl, Valentin; Sorg, Christian

    2016-01-01

    The human brain's ongoing activity is characterized by intrinsic networks of coherent fluctuations, measured for example with correlated functional magnetic resonance imaging signals. So far, however, the brain processes underlying this ongoing blood oxygenation level dependent (BOLD) signal orchestration and their direct relevance for human behavior are not sufficiently understood. In this study, we address the question of whether and how ongoing BOLD activity within intrinsic occipital networks impacts on conscious visual perception. To this end, backwardly masked targets were presented in participants' left visual field only, leaving the ipsi-lateral occipital areas entirely free from direct effects of task throughout the experiment. Signal time courses of ipsi-lateral BOLD fluctuations in visual areas V1 and V2 were then used as proxies for the ongoing contra-lateral BOLD activity within the bilateral networks. Magnitude and phase of these fluctuations were compared in trials with and without conscious visual perception, operationalized by means of subjective confidence ratings. Our results show that ipsi-lateral BOLD magnitudes in V1 were significantly higher at times of peak response when the target was perceived consciously. A significant difference between conscious and non-conscious perception with regard to the pre-target phase of an intrinsic-frequency regime suggests that ongoing V1 fluctuations exert a decisive impact on the access to consciousness already before stimulation. Both effects were absent in V2. These results thus support the notion that ongoing slow BOLD activity within intrinsic networks covering V1 represents localized processes that modulate the degree of readiness for the emergence of visual consciousness.

  3. Hexagonal@Cubic CdS Core@Shell Nanorod Photocatalyst for Highly Active Production of H2 with Unprecedented Stability.

    Li, Kui; Han, Min; Chen, Rong; Li, Shun-Li; Xie, Shuai-Lei; Mao, Chengyu; Bu, Xianhui; Cao, Xue-Li; Dong, Long-Zhang; Feng, Pingyun; Lan, Ya-Qian

    2016-10-01

    A highly effective, low-cost strategy for improved photocatalytic efficiency and stability of CdS is described. Based on the integration of hexagonal-cubic core-shell architecture with nanorod morphology, the concentric CdS nanorod phase junctions (NRPJs) obtained demonstrate extremely high H2 production rate and unprecedented photocatalytic stability.

  4. Fluctuations of conserved charges in relativistic heavy ion collisions: An introduction

    Asakawa, Masayuki; Kitazawa, Masakiyo

    2016-09-01

    Bulk fluctuations of conserved charges measured by event-by-event analysis in relativistic heavy ion collisions are observables which are believed to carry significant amount of information on the hot medium created by the collisions. Active studies have been done recently experimentally, theoretically, and on the lattice. In particular, non-Gaussianity of the fluctuations has acquired much attention recently. In this review, we give a pedagogical introduction to these issues, and survey recent developments in this field of research. Starting from the definition of cumulants, basic concepts in fluctuation physics, such as thermal fluctuations in statistical mechanics and time evolution of fluctuations in diffusive systems, are described. Phenomena which are expected to occur in finite temperature and/or density QCD matter and their measurement by event-by-event analyses are also elucidated.

  5. Fluctuations of conserved charges in relativistic heavy ion collisions: An introduction

    Asakawa, Masayuki

    2015-01-01

    Bulk fluctuations of conserved charges measured by event-by-event analysis in relativistic heavy ion collisions are observables which are believed to carry significant information on the primordial thermodynamics of the hot medium created by the collisions. Active studies have been done recently experimentally, theoretically, and on the lattice. In particular, non-Gaussianity of the fluctuations aquires much attention recently. In this review, we give a pedagogical introduction to these physics, and overview recent developments in this field of research. Starting from the definition of cumulants, basic concepts in fluctuation physics, such as thermal fluctuations in statistical mechanics and time evolution of fluctuations in diffusive systems, are described. Physics which are expected to occur in the QCD phase diagram and their measurement by event-by-event analyses are also elucidated.

  6. Drilling history core hole DC-8

    1978-10-01

    Core hole DC-8 was completed in August, 1978 by Boyles Brothers Drilling Company, Spokane, Washington, under subcontract to Fenix and Scission, Inc. The hole was cored for the US Department of Energy and the Rockwell Hanford Operations' Basalt Waste Isolation Program. Fenix and Scisson, Inc. furnished the engineering, daily supervision of the core drilling activities, and geologic core logging for hole DC-8. Core hole DC-8 is located on the Hanford Site near the Wye Barricade and 50 feet northwest of rotary hole DC-7. The Hanford Site vation coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 coordinates for DC-8 are North 14,955.94 feet and West 14,861.92 mean sea level. The purpose of core hole DC-8 was to core drill vertically through the basalt and interbed units for stratigraphic depth determination and core collection, and to provide a borehole for hydrologic testing and cross-hole seismic shear and pressure wave velocity studies with rotary hole DC-7. The total depth of core hole DC-8 was 4100.5 feet. Core recovery exceeded 97 percent of the total footage cored.

  7. Classical and quantum temperature fluctuations via holography

    Balatsky, Alexander [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Institute for Materials Science, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); Gudnason, Sven Bjarke; Kedem, Yaron [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Krikun, Alexander [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Institute of Theoretical and Experimental Physics,B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Thorlacius, Lárus [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); University of Iceland, Science Institute,Dunhaga 3, IS-107 Reykjavik (Iceland); The Oskar Klein Centre for Cosmoparticle Physics, Department of Physics,Stockholm University, AlbaNova University Centre, 10691 Stockholm (Sweden); Zarembo, Konstantin [Nordita, KTH Royal Institute of Technology and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Institute of Theoretical and Experimental Physics,B. Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Department of Physics and Astronomy, Uppsala University,SE-751 08 Uppsala (Sweden)

    2015-01-07

    We study local temperature fluctuations in a 2+1 dimensional CFT on the sphere, dual to a black hole in asymptotically AdS spacetime. The fluctuation spectrum is governed by the lowest-lying hydrodynamic modes of the system whose frequency and damping rate determine whether temperature fluctuations are thermal or quantum. We calculate numerically the corresponding quasinormal frequencies and match the result with the hydrodynamics of the dual CFT at high temperature. As a by-product of our analysis we determine the appropriate boundary conditions for calculating low-lying quasinormal modes for a four-dimensional Reissner-Nordström black hole in global AdS.

  8. Diffusive transport by thermal velocity fluctuations.

    Donev, Aleksandar; Bell, John B; de la Fuente, Anton; Garcia, Alejandro L

    2011-05-20

    We study the contribution of advection by thermal velocity fluctuations to the effective diffusion coefficient in a mixture of two identical fluids. We find good agreement between a simple fluctuating hydrodynamics theory and particle and finite-volume simulations. The enhancement of the diffusive transport depends on the system size L and grows as ln(L/L₀) in quasi-two-dimensional systems, while in three dimensions it scales as L₀⁻¹ - L⁻¹, where L₀ is a reference length. Our results demonstrate that fluctuations play an important role in the hydrodynamics of small-scale systems.

  9. Population Genetics with Fluctuating Population Sizes

    Chotibut, Thiparat

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuations-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  10. Fluctuations of coupled fluid and solid membranes with application to red blood cells

    Auth, Thorsten; Safran, S. A.; Gov, Nir S.

    2007-11-01

    The fluctuation spectra and the intermembrane interaction of two membranes at a fixed average distance are investigated. Each membrane can either be a fluid or a solid membrane, and in isolation, its fluctuations are described by a bare or a wave-vector-dependent bending modulus, respectively. The membranes interact via their excluded-volume interaction; the average distance is maintained by an external, homogeneous pressure. For strong coupling, the fluctuations can be described by a single, effective membrane that combines the elastic properties. For weak coupling, the fluctuations of the individual, noninteracting membranes are recovered. The case of a composite membrane consisting of one fluid and one solid membrane can serve as a microscopic model for the plasma membrane and cytoskeleton of the red blood cell. We find that, despite the complex microstructure of bilayers and cytoskeletons in a real cell, the fluctuations with wavelengths λ≳400nm are well described by the fluctuations of a single, polymerized membrane (provided that there are no inhomogeneities of the microstructure). The model is applied to the fluctuation data of discocytes (“normal” red blood cells), a stomatocyte, and an echinocyte. The elastic parameters of the membrane and an effective temperature that quantifies active, metabolically driven fluctuations are extracted from the experiments.

  11. Core competencies in internal medicine.

    Porcel, José Manuel; Casademont, Jordi; Conthe, Pedro; Pinilla, Blanca; Pujol, Ramón; García-Alegría, Javier

    2012-06-01

    The working group on Competencies of Internal Medicine from the Spanish Society of Internal Medicine (SEMI) proposes a series of core competencies that we consider should be common to all European internal medicine specialists. The competencies include aspects related to patient care, clinical knowledge, technical skills, communication skills, professionalism, cost-awareness in medical care and academic activities. The proposal could be used as a working document for the Internal Medicine core curriculum in the context of the educational framework of medical specialties in Europe.

  12. Evidence for in-situ metabolic activity in ice sheets based on anomalous trace gas records from the Vostok and other ice cores

    Sowers, T.

    2003-04-01

    Measurements of trace gas species in ice cores are the primary means for reconstructing the composition of the atmosphere. The longest such record comes from the Vostok core taken from the central portion of the East Antarctic ice sheet [Petit et al., 1999]. In general, the trace gas records from Vostok are utilized as the reference signal when correlating trace gas measurements from other ice cores. The underlying assumption implicit in such endeavors is that the bubbles recovered from the ice cores record the composition of the atmosphere at the time the bubbles were formed. Another implicit assumption is that the composition of the bubbles has not been compromised by the extremely long storage periods within the ice sheet. While there is ample evidence that certain trace gas records (e.g. CO2 and CH4) have probably not been compromised, anomalous nitrous oxide (N2O) measurements from the penultimate glacial termination at Vostok are consistent with in-situ (N2O) production [Sowers, 2001]. In general, trace gas measurements from high altitude tropical/temperate glaciers are higher than expected based on contemporaneous measurements from polar cores. Measurements spanning the last 25kyr from the Sajama ice core from central Bolivia (18oS, 69oW, 6542masl), for example, were 1X-5X higher than contemporaneous values recorded in polar ice cores [Campen et al., 2003]. While other physical factors (like temperature/melting) may contribute to the elevated trace gas levels at these sites, the most likely explanation involves the accumulation of in-situ metabolic trace gas byproducts. Stable isotope measurements provide independent information for assessing the origin of the elevated trace gas levels in select samples. For the penultimate glacial termination at Vostok, the anomalous (N2O) values carry high δ15Nbulk and low δ18Obulk values that would be predicted if the added (N2O) was associated with in-situ nitrification. At Sajama, low δ13CH4 values observed during

  13. Comodules over semiperfect corings

    Caenepeel, S

    2011-01-01

    We discuss when the Rat functor associated to a coring satisfying the left $\\alpha$-condition is exact. We study the category of comodules over a semiperfect coring. We characterize semiperfect corings over artinian rings and over qF-rings.

  14. Coring Sample Acquisition Tool

    Haddad, Nicolas E.; Murray, Saben D.; Walkemeyer, Phillip E.; Badescu, Mircea; Sherrit, Stewart; Bao, Xiaoqi; Kriechbaum, Kristopher L.; Richardson, Megan; Klein, Kerry J.

    2012-01-01

    A sample acquisition tool (SAT) has been developed that can be used autonomously to sample drill and capture rock cores. The tool is designed to accommodate core transfer using a sample tube to the IMSAH (integrated Mars sample acquisition and handling) SHEC (sample handling, encapsulation, and containerization) without ever touching the pristine core sample in the transfer process.

  15. The variation in the magnetic fluctuation anisotropy across the front boundaries of magnetic clouds and its geomagnetic response

    2002-01-01

    A statistical study of magnetic fluctuations near the front boundaries of magnetic clouds is approached with the method of Minimum Variance Analysis, based on the data of Imp8 and Wind spacecraft. New discoveries are that (1) fluctuation anisotropy tends to increase across the front boundaries of magnetic clouds; (2) there is a good correlation between the fluctuation anisotropy and the geomagnetic activity indices; and (3) in some cases, although there is southward field component immediately after the front boundary, Kp index descends (or Dst index ascends) with a corresponding decrease of the fluctuation anisotropy; in other cases with no distinct southward field component, Kp index ascends (or Dst index descends) with a corresponding increase of the fluctuation anisotropy. Thus we suggest that the fluctuation anisotropy might be a useful indicator in diagnosing the magnetic activities of magnetic clouds.

  16. Generalized fluctuation theorems for classical systems

    Agarwal, G S

    2015-01-01

    Fluctuation theorems have a very special place in the study of non equilibrium dynamics of physical systems. The form in which it is used most extensively is the Gallavoti-Cohen Fluctuation Theorem which is in terms of the distribution of the work $p(W)/p(-W)=\\exp(\\alpha W)$. We derive the general form of the fluctuation theorems for an arbitrary Gaussian Markov process and find conditions when the parameter $\\alpha$ becomes a universal parameter $1/kT$. As an application we consider fluctuation theorems for classical cyclotron motion of an electron in a parabolic potential. The motion of the electron is described by four coupled Langevin equations and thus is non-trivial. The generalized theorems are equally valid for non-equilibrium steady states.

  17. Vacuum Radiation Pressure Fluctuations and Barrier Penetration

    Huang, Haiyan

    2016-01-01

    We apply recent results on the probability distribution for quantum stress tensor fluctuations to the problem of barrier penetration by quantum particles. The probability for large stress tensor fluctuations decreases relatively slowly with increasing magnitude of the fluctuation, especially when the quantum stress tensor operator has been averaged over a finite time interval. This can lead to large vacuum radiation pressure fluctuations on charged or polarizable particles, which can in turn push the particle over a potential barrier. The rate for this effect depends sensitively upon the details of the time averaging of the stress tensor operator, which might be determined by factors such as the shape of the potential. We make some estimates for the rate of barrier penetration by this mechanism and argue that in some cases this rate can exceed the rate for quantum tunneling through the barrier. The possibility of observation of this effect is discussed.

  18. Resonances and fluctuations in the statistical model

    Torrieri Giorgio

    2012-11-01

    Full Text Available We describe how the study of resonances and fluctuations can help constrain the thermal and chemical freezeout properties of the fireball created in heavy ion collisions. This review is based on [1–5

  19. Metric fluctuations and its evolution during inflation

    Anabitarte, M; Anabitarte, Mariano; Bellini, Mauricio

    2003-01-01

    W discuss the evolution of the fluctuations in a symmetric $\\phi_c$-exponential potential which provides a power-law expansion during inflation using both, the gauge invariant field $\\Phi$ and the Sasaki-Mukhanov field.

  20. Fractal fluctuations in gaze speed visual search.

    Stephen, Damian G; Anastas, Jason

    2011-04-01

    Visual search involves a subtle coordination of visual memory and lower-order perceptual mechanisms. Specifically, the fluctuations in gaze may provide support for visual search above and beyond what may be attributed to memory. Prior research indicates that gaze during search exhibits fractal fluctuations, which allow for a wide sampling of the field of view. Fractal fluctuations constitute a case of fast diffusion that may provide an advantage in exploration. We present reanalyses of eye-tracking data collected by Stephen and Mirman (Cognition, 115, 154-165, 2010) for single-feature and conjunction search tasks. Fluctuations in gaze during these search tasks were indeed fractal. Furthermore, the degree of fractality predicted decreases in reaction time on a trial-by-trial basis. We propose that fractality may play a key role in explaining the efficacy of perceptual exploration.