WorldWideScience

Sample records for active core fluctuations

  1. Fluctuating gravity of Earth’s core

    OpenAIRE

    Stevenson, David J.

    2012-01-01

    For centuries, we have known that Earth’s magnetic field varies with time. Edmond Halley (better known for his eponymous recurring comet) first recognized this time variation of magnetic compass needle direction and even offered a remarkable theory that required an intervening fluid between Earth’s solid outer shell and a hypothesized innermost solid core (1). For decades, consensus has emerged for an explanation of this time variation that depends on the dynamics of Earth’s liquid metallic o...

  2. Current fluctuations of interacting active Brownian particles

    OpenAIRE

    Pre, Trevor Grand; Limmer, David T.

    2018-01-01

    We derive the distribution function for particle currents for a system of interacting active Brownian particles in the long time limit using large deviation theory and a weighted many body expansion. We find the distribution is non-Gaussian, except in the limit of passive particles. The non-Gaussian fluctuations can be understood from the effective potential the particles experience when conditioned on a given current. This potential suppresses fluctuations of the particle's orientation, and ...

  3. The simultaneous measurements of core and outer core density fluctuations in L-H transition using CO2 laser collective scattering diagnostic in the EAST superconducting tokamak

    International Nuclear Information System (INIS)

    Cao, G.M.; Li, Y.D.; Zhang, X.D.; Sun, P.J.; Hu, L.Q.; Li, J.G.; Wu, G.J.

    2013-01-01

    The H-mode is the projected basic operation scenario for the ITER tokamak. The turbulence de-correlation by the synergistic effect of zonal flow and equilibrium ExB flow shear is believed to be the reason for L-H transition, however, the detailed physical mechanism has not been identified so far. Tangential multi-channel CO 2 laser collective scattering diagnostic system (mainly k r measurement) was first installed to investigate electron density fluctuations on EAST tokamak. The measurements in a spontaneous dithering L-H transition show that in core plasma (0 < r/a < 0.5) the low-frequency fluctuations strengthen greatly before L-H transition; meanwhile in outer core plasma (0.2 < r/a < 1) the low-frequency fluctuations strengthen slightly. Bispectral analysis reveals that the coupling strength between low- and high-frequency fluctuations in both core and outer core plasma strengthens greatly before the transition, but the latter is greater than the former. The results indicate that the low-frequency fluctuations of the core and outer core plasma play active, but different, roles in the spontaneous L-H transition. (author)

  4. Measurement of core velocity fluctuations and the dynamo in a reversed-field pinch

    International Nuclear Information System (INIS)

    Den Hartog, D.J.; Craig, D.; Fiksel, G.; Fontana, P.W.; Prager, S.C.; Sarff, J.S.; Chapman, J.T.

    1998-01-01

    Plasma flow velocity fluctuations have been directly measured in the high temperature magnetically confined plasma in the Madison Symmetric Torus (MST) Reversed-Field Pinch (RFP). These measurements show that the flow velocity fluctuations are correlated with magnetic field fluctuations. This initial measurement is subject to limitations of spatial localization and other uncertainties, but is evidence for sustainment of the RFP magnetic field configuration by the magnetohydrodynamic (MHD) dynamo. Both the flow velocity and magnetic field fluctuations are the result of global resistive MHD modes of helicity m = 1, n = 5--10 in the core of MST. Chord-averaged flow velocity fluctuations are measured in the core of MST by recording the Doppler shift of impurity line emission with a specialized high resolution and throughput grating spectrometer. Magnetic field fluctuations are recorded with a large array of small edge pickup coils, which allows spectral decomposition into discrete modes and subsequent correlation with the velocity fluctuation data

  5. Effective tension and fluctuations in active membranes.

    Science.gov (United States)

    Loubet, Bastien; Seifert, Udo; Lomholt, Michael Andersen

    2012-03-01

    We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular, we take constraints on the membrane area and the volume of fluid that it encapsulates into account when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the nonthermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane, a curvature force, which models a fluctuating spontaneous curvature, and a permeation force coming from an active transport of fluid through the membrane. For the direct force and curvature force cases, we compare our results to existing experiments on active membranes.

  6. Active Brownian particles with velocity-alignment and active fluctuations

    International Nuclear Information System (INIS)

    Großmann, R; Schimansky-Geier, L; Romanczuk, P

    2012-01-01

    We consider a model of active Brownian particles (ABPs) with velocity alignment in two spatial dimensions with passive and active fluctuations. Here, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed to be independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account, for example, for thermal fluctuations. We derive a macroscopic description of the ABP gas with velocity-alignment interaction. Here, we start from the individual-based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse-grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here on the different impact of active and passive fluctuations on onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuations lead to an earlier breakdown of collective motion and to the emergence of a new bistable regime in the mean-field case. (paper)

  7. Numerical analysis of temperature fluctuation in core outlet region of China experimental fast reactor

    International Nuclear Information System (INIS)

    Zhu Huanjun; Xu Yijun

    2014-01-01

    The temperature fluctuation in core outlet region of China Experimental Fast Reactor (CEFR) was numerically simulated by the CFD software Star CCM+. With the core outlet temperatures, flows etc. under rated conditions given as boundary conditions, a 1/4 region model of the reactor core outlet region was established and calculated using LES method for this problem. The analysis results show that while CEFR operates under rated conditions, the temperature fluctuation in lower part of core outlet region is mainly concentrated in area over the edge components (steel components, control rod assembly), and one in upper part is remarkable in area above all the components. The largest fluctuation amplitude is 19 K and the remarkable frequency is below 5 Hz, and it belongs to typically low frequency fluctuation. The conclusion is useful for further experimental work. (authors)

  8. Core fluctuations and current profile dynamics in the MST reversed-field pinch

    International Nuclear Information System (INIS)

    Brower, D.L.; Ding, W.X.; Lei, J.

    2003-01-01

    First measurements of the current density profile, magnetic field fluctuations and electrostatic (e.s.) particle flux in the core of a high-temperature reversed-field pinch (RFP) are presented. We report three new results: (1) The current density peaks during the slow ramp phase of the sawtooth cycle and flattens promptly at the crash. Profile flattening can be linked to magnetic relaxation and the dynamo which is predicted to drive anti-parallel current in the core. Measured core magnetic fluctuations are observed to increases four-fold at the crash. Between sawtooth crashes, measurements indicate the particle flux driven by e.s. fluctuations is too small to account for the total radial particle flux. (2) Core magnetic fluctuations are observed to decrease at least twofold in plasmas where energy confinement time improves ten-fold. In this case, the radial particle flux is also reduced, suggesting core e.s. fluctuation-induced transport may play role in confinement. (3) The parallel current density increases in the outer region of the plasma during high confinement, as expected, due to the applied edge parallel electric field. However, the core current density also increases due to dynamo reduction and the emergence of runaway electrons. (author)

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

    OpenAIRE

    J. Azuara; N. Combourieu-Nebout; V. Lebreton; F. Mazier; S. D. Müller; L. Dezileau

    2015-01-01

    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 ove...

  10. Thermal and active fluctuations of a compressible bilayer vesicle

    Science.gov (United States)

    Sachin Krishnan, T. V.; Yasuda, Kento; Okamoto, Ryuichi; Komura, Shigeyuki

    2018-05-01

    We discuss thermal and active fluctuations of a compressible bilayer vesicle by using the results of hydrodynamic theory for vesicles. Coupled Langevin equations for the membrane deformation and the density fields are employed to calculate the power spectral density matrix of membrane fluctuations. Thermal contribution is obtained by means of the fluctuation dissipation theorem, whereas active contribution is calculated from exponentially decaying time correlation functions of active random forces. We obtain the total power spectral density as a sum of thermal and active contributions. An apparent response function is further calculated in order to compare with the recent microrheology experiment on red blood cells. An enhanced response is predicted in the low-frequency regime for non-thermal active fluctuations.

  11. Effective tension and fluctuations in active membranes

    OpenAIRE

    Loubet, Bastien; Seifert, Udo; Lomholt, Michael Andersen

    2011-01-01

    We calculate the fluctuation spectrum of the shape of a lipid vesicle or cell exposed to a nonthermal source of noise. In particular we take into account constraints on the membrane area and the volume of fluid that it encapsulates when obtaining expressions for the dependency of the membrane tension on the noise. We then investigate three possible origins of the non-thermal noise taken from the literature: A direct force, which models an external medium pushing on the membrane. A curvature f...

  12. Interplay between edge and outer core fluctuations in the tokamak Tore Supra

    International Nuclear Information System (INIS)

    Fenzi, C.; Garbet, X.; Capes, H.; Devynck, P.; Laviron, C.; Truc, A.; Gervais, F.; Hennequin, P.; Quemeneur, A.

    2000-01-01

    In the tokamak Tore Supra, when a poloidally and toroidally localized limiter, called a modular limiter, is introduced into the lower part of the scrape-off layer, density fluctuations located in the vicinity of this limiter present a specific feature with the appearance of a new spectral pattern in the associated frequency spectrum. This leads to a strong up-down asymmetry observed in both the plasma edge and the plasma outer core, with a maximum level of turbulence at the bottom of the plasma. The observed asymmetry characteristics show that magnetic connection lengths play a critical role here and that the limiter configuration has some effect on the outer core turbulence. (author)

  13. Suppression of alloy fluctuations in GaAs-AlGaAs core-shell nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Loitsch, Bernhard; Winnerl, Julia; Parzinger, Eric; Matich, Sonja; Wurstbauer, Ursula; Riedl, Hubert; Abstreiter, Gerhard; Finley, Jonathan J.; Koblmüller, Gregor [Walter Schottky Institut and Physik Department, Technische Universität München, 85748 Garching (Germany); Jeon, Nari; Lauhon, Lincoln J. [Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Döblinger, Markus [Department of Chemistry, Ludwig-Maximilians-Universität Munich, 81377 München (Germany)

    2016-08-29

    Probing localized alloy fluctuations and controlling them by growth kinetics have been relatively limited so far in nanoscale structures such as semiconductor nanowires (NWs). Here, we demonstrate the tuning of alloy fluctuations in molecular beam epitaxially grown GaAs-AlGaAs core-shell NWs by modifications of shell growth temperature, as investigated by correlated micro-photoluminescence, scanning transmission electron microscopy, and atom probe tomography. By reducing the shell growth temperature from T > 600 °C to below 400 °C, we find a strong reduction in alloy fluctuation mediated sharp-line luminescence, concurrent with a decrease in the non-randomness of the alloy distribution in the AlGaAs shell. This trend is further characterized by a change in the alloy compositional structure from unintentional quasi-superlattices of Ga- and Al-rich AlGaAs layers at high T to a nearly homogeneous random alloy distribution at low T.

  14. Density fluctuation effects on collective neutrino oscillations in O-Ne-Mg core-collapse supernovae

    International Nuclear Information System (INIS)

    Cherry, John F.; Fuller, George M.; Wu Mengru; Qian Yongzhong; Carlson, J.; Duan Huaiyu

    2011-01-01

    We investigate the effect of matter density fluctuations on supernova collective neutrino flavor oscillations. In particular, we use full multiangle, three-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 breakout (neutronization neutrino 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 ν e 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 also show that the interplay of neutrino self-coupling and matter fluctuation could cause a significant increase in the ν e survival probability at very low energy.

  15. Intrinsically-generated fluctuating activity in excitatory-inhibitory networks

    Science.gov (United States)

    Mastrogiuseppe, Francesca; Ostojic, Srdjan

    2017-01-01

    Recurrent networks of non-linear units display a variety of dynamical regimes depending on the structure of their synaptic connectivity. A particularly remarkable phenomenon is the appearance of strongly fluctuating, chaotic activity in networks of deterministic, but randomly connected rate units. How this type of intrinsically generated fluctuations appears in more realistic networks of spiking neurons has been a long standing question. To ease the comparison between rate and spiking networks, recent works investigated the dynamical regimes of randomly-connected rate networks with segregated excitatory and inhibitory populations, and firing rates constrained to be positive. These works derived general dynamical mean field (DMF) equations describing the fluctuating dynamics, but solved these equations only in the case of purely inhibitory networks. Using a simplified excitatory-inhibitory architecture in which DMF equations are more easily tractable, here we show that the presence of excitation qualitatively modifies the fluctuating activity compared to purely inhibitory networks. In presence of excitation, intrinsically generated fluctuations induce a strong increase in mean firing rates, a phenomenon that is much weaker in purely inhibitory networks. Excitation moreover induces two different fluctuating regimes: for moderate overall coupling, recurrent inhibition is sufficient to stabilize fluctuations; for strong coupling, firing rates are stabilized solely by the upper bound imposed on activity, even if inhibition is stronger than excitation. These results extend to more general network architectures, and to rate networks receiving noisy inputs mimicking spiking activity. Finally, we show that signatures of the second dynamical regime appear in networks of integrate-and-fire neurons. PMID:28437436

  16. Late Holocene vegetation changes in relation with climate fluctuations and human activity in Languedoc (southern France)

    OpenAIRE

    Azuara , J; Combourieu-Nebout , N; Lebreton , V; Mazier , F; Müller , S D; Dezileau , L ,

    2015-01-01

    International audience; Holocene climate fluctuations and human activity since the Neolithic have shaped present-day Mediter-ranean environments. Separating anthropogenic effects from climatic impacts to better understand Mediterranean pale-oenvironmental changes over the last millennia remains a challenging issue. High-resolution pollen analyses were un-dertaken on two cores from the Palavasian lagoon system (Hérault, southern France). These records allow reconstruction of vegetation dynamic...

  17. Ras activation by SOS: Allosteric regulation by altered fluctuation dynamics

    Science.gov (United States)

    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.

    2014-01-01

    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. PMID:24994643

  18. Entropy Production and Fluctuation Theorems for Active Matter

    Science.gov (United States)

    Mandal, Dibyendu; Klymko, Katherine; DeWeese, Michael R.

    2017-12-01

    Active biological systems reside far from equilibrium, dissipating heat even in their steady state, thus requiring an extension of conventional equilibrium thermodynamics and statistical mechanics. In this Letter, we have extended the emerging framework of stochastic thermodynamics to active matter. In particular, for the active Ornstein-Uhlenbeck model, we have provided consistent definitions of thermodynamic quantities such as work, energy, heat, entropy, and entropy production at the level of single, stochastic trajectories and derived related fluctuation relations. We have developed a generalization of the Clausius inequality, which is valid even in the presence of the non-Hamiltonian dynamics underlying active matter systems. We have illustrated our results with explicit numerical studies.

  19. Impact of climate fluctuations on deposition of DDT and hexachlorocyclohexane in mountain glaciers: Evidence from ice core records

    International Nuclear Information System (INIS)

    Wang Xiaoping; Gong Ping; Zhang, Qianggong; Yao Tandong

    2010-01-01

    How do climate fluctuations affect DDT and hexachlorocyclohexane (HCH) distribution in the global scale? In this study, the interactions between climate variations and depositions of DDT and HCH in ice cores from Mt. Everest (the Tibetan Plateau), Mt. Muztagata (the eastern Pamirs) and the Rocky Mountains were investigated. All data regarding DDT/HCH deposition were obtained from the published results. Concentrations of DDT and HCH in an ice core from Mt. Everest were associated with the El Nino-Southern Oscillation. Concentrations of DDT in an ice core from Mt. Muztagata were significantly correlated with the Siberia High pattern. Concentrations of HCH in an ice core from Snow Dome of the Rocky Mountains responded to the North Atlantic Oscillation. These associations suggested that there are some linkages between climate variations and the global distribution of persistent organic pollutants. - Our study approves the potential contribution of ice core records of POPs to transport mechanisms of POPs.

  20. Contralateral Delay Activity Tracks Fluctuations in Working Memory Performance.

    Science.gov (United States)

    Adam, Kirsten C S; Robison, Matthew K; Vogel, Edward K

    2018-01-08

    Neural measures of working memory storage, such as the contralateral delay activity (CDA), are powerful tools in working memory research. CDA amplitude is sensitive to working memory load, reaches an asymptote at known behavioral limits, and predicts individual differences in capacity. An open question, however, is whether neural measures of load also track trial-by-trial fluctuations in performance. Here, we used a whole-report working memory task to test the relationship between CDA amplitude and working memory performance. If working memory failures are due to decision-based errors and retrieval failures, CDA amplitude would not differentiate good and poor performance trials when load is held constant. If failures arise during storage, then CDA amplitude should track both working memory load and trial-by-trial performance. As expected, CDA amplitude tracked load (Experiment 1), reaching an asymptote at three items. In Experiment 2, we tracked fluctuations in trial-by-trial performance. CDA amplitude was larger (more negative) for high-performance trials compared with low-performance trials, suggesting that fluctuations in performance were related to the successful storage of items. During working memory failures, participants oriented their attention to the correct side of the screen (lateralized P1) and maintained covert attention to the correct side during the delay period (lateralized alpha power suppression). Despite the preservation of attentional orienting, we found impairments consistent with an executive attention theory of individual differences in working memory capacity; fluctuations in executive control (indexed by pretrial frontal theta power) may be to blame for storage failures.

  1. Core density fluctuations in reverse magnetic shear plasmas with internal transport barrier on JT-60U

    International Nuclear Information System (INIS)

    Nazikian, R.; Shinohara, K.; Yoshino, R.; Fujita, T.; Shirai, H.; Kramer, G.T.

    1999-01-01

    First measurements of the radial correlation length of density fluctuations in JT-60U plasmas with internal transport barrier (ITB) is reported. The measurements are obtained using a newly installed correlation reflectometer operating in the upper X-mode. Before transport barrier formation in the low beam power current ramp-up phase of the discharge, reflectometer measurements indicate density fluctuation levels n-tilde/n∼0.1-0.2% and radial correlation lengths 2-3 cm (k r p i ≤0.5) in the central plasma region (r/a r p i ∼3. However, fluctuation levels are considerably higher than measured near the magnetic axis. Reflectometer measurements obtained at the foot of the ITB also indicate high fluctuation levels compared to measurements in the central region of the discharge. (author)

  2. Activation of Selected Core Muscles during Pressing

    OpenAIRE

    Thomas W. Nesser; Neil Fleming; Matthew J. Gage

    2015-01-01

    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 grou...

  3. Core Muscle Activation in Suspension Training Exercises.

    Science.gov (United States)

    Cugliari, Giovanni; Boccia, Gennaro

    2017-02-01

    A quantitative observational laboratory study was conducted to characterize and classify core training exercises executed in a suspension modality on the base of muscle activation. In a prospective single-group repeated measures design, seventeen active male participants performed four suspension exercises typically associated with core training (roll-out, bodysaw, pike and knee-tuck). Surface electromyographic signals were recorded from lower and upper parts of rectus abdominis, external oblique, internal oblique, lower and upper parts of erector spinae muscles using concentric bipolar electrodes. The average rectified values of electromyographic signals were normalized with respect to individual maximum voluntary isometric contraction of each muscle. Roll-out exercise showed the highest activation of rectus abdominis and oblique muscles compared to the other exercises. The rectus abdominis and external oblique reached an activation higher than 60% of the maximal voluntary contraction (or very close to that threshold, 55%) in roll-out and bodysaw exercises. Findings from this study allow the selection of suspension core training exercises on the basis of quantitative information about the activation of muscles of interest. Roll-out and bodysaw exercises can be considered as suitable for strength training of rectus abdominis and external oblique muscles.

  4. Changes in core electron temperature fluctuations across the ohmic energy confinement transition in Alcator C-Mod plasmas

    International Nuclear Information System (INIS)

    Sung, C.; White, A.E.; Howard, N.T.; Oi, C.Y.; Rice, J.E.; Gao, C.; Ennever, P.; Porkolab, M.; Parra, F.; Ernst, D.; Walk, J.; Hughes, J.W.; Irby, J.; Kasten, C.; Hubbard, A.E.; Greenwald, M.J.; Mikkelsen, D.

    2013-01-01

    The first measurements of long wavelength (k y ρ s < 0.3) electron temperature fluctuations in Alcator C-Mod made with a new correlation electron cyclotron emission diagnostic support a long-standing hypothesis regarding the confinement transition from linear ohmic confinement (LOC) to saturated ohmic confinement (SOC). Electron temperature fluctuations decrease significantly (∼40%) crossing from LOC to SOC, consistent with a change from trapped electron mode (TEM) turbulence domination to ion temperature gradient (ITG) turbulence as the density is increased. Linear stability analysis performed with the GYRO code (Candy and Waltz 2003 J. Comput. Phys. 186 545) shows that TEMs are dominant for long wavelength turbulence in the LOC regime and ITG modes are dominant in the SOC regime at the radial location (ρ ∼ 0.8) where the changes in electron temperature fluctuations are measured. In contrast, deeper in the core (ρ < 0.8), linear stability analysis indicates that ITG modes remain dominant across the LOC/SOC transition. This radial variation suggests that the robust global changes in confinement of energy and momentum occurring across the LOC/SOC transition are correlated to local changes in the dominant turbulent mode near the edge. (paper)

  5. Activation of Selected Core Muscles during Pressing

    Directory of Open Access Journals (Sweden)

    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

  6. Mood Fluctuation and Psychobiological Instability: The Same Core Functions Are Disrupted by Novel Psychoactive Substances and Established Recreational Drugs

    Directory of Open Access Journals (Sweden)

    Andrew C. Parrott

    2018-03-01

    Full Text Available Many novel psychoactive substances (NPS have entered the recreational drug scene in recent years, yet the problems they cause are similar to those found with established drugs. This article will debate the psychobiological effects of these newer and more traditional substances. It will show how they disrupt the same core psychobiological functions, so damaging well-being in similar ways. Every psychoactive drug causes mood states to fluctuate. Users feel better on-drug, then feel worse off-drug. The strength of these mood fluctuations is closely related to their addiction potential. Cyclical changes can occur with many other core psychobiological functions, such as information processing and psychomotor speed. Hence the list of drug-related impairments can include: homeostatic imbalance, HPA axis disruption, increased stress, altered sleep patterns, neurohormonal changes, modified brain rhythms, neurocognitive impairments, and greater psychiatric vulnerability. Similar patterns of deficit are found with older drugs such as cocaine, nicotine and cannabis, and newer substances such as 3,4-methylenedioxymethamphetamine (MDMA, mephedrone and spice. All psychoactive drugs damage human well-being through similar basic neuropsychobiological mechanisms.

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

    Science.gov (United States)

    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.

  8. [Core muscle chains activation during core exercises determined by EMG-a systematic review].

    Science.gov (United States)

    Rogan, Slavko; Riesen, Jan; Taeymans, Jan

    2014-10-15

    Good core muscles strength is essential for daily life and sports activities. However, the mechanism how core muscles may be effectively triggered by exercises is not yet precisely described in the literature. The aim of this systematic review was to evaluate the rate of activation as measured by electromyography of the ventral, lateral and dorsal core muscle chains during core (trunk) muscle exercises. A total of 16 studies were included. Exercises with a vertical starting position, such as the deadlift or squat activated significantly more core muscles than exercises in the horizontal initial position.

  9. STAR FORMATION ACTIVITY OF CORES WITHIN INFRARED DARK CLOUDS

    International Nuclear Information System (INIS)

    Chambers, E. T.; Jackson, J. M.; Rathborne, J. M.; Simon, R.

    2009-01-01

    Infrared Dark Clouds (IRDCs) contain compact cores which probably host the early stages of high-mass star formation. Many of these cores contain regions of extended, enhanced 4.5 μm emission, the so-called 'green fuzzies', which indicate shocked gas. Many cores also contain 24 μm emission, presumably from heated dust which indicates embedded protostars. Because 'green fuzzies' and 24 μm point sources both indicate star formation, we have developed an algorithm to identify star-forming cores within IRDCs by searching for the simultaneous presence of these two distinct indicators. We employ this algorithm on a sample of 190 cores found toward IRDCs, and classify the cores as 'active' if they contain a green fuzzy coincident with an embedded 24 μm source, and as 'quiescent' if they contain neither IR signature. We hypothesize that the 'quiescent' cores represent the earliest 'preprotostellar' (starless) core phase, before the development of a warm protostar, and that the 'active' cores represent a later phase, after the development of a protostar. We test this idea by comparing the sizes, densities, and maser activity of the 'active' and 'quiescent' cores. We find that, on average, 'active' cores have smaller sizes, higher densities, and more pronounced water and methanol maser activity than the 'quiescent' cores. This is expected if the 'quiescent' cores are in an earlier evolutionary state than the 'active' cores. The masses of 'active' cores suggest that they may be forming high-mass stars. The highest mass 'quiescent' cores are excellent candidates for the elusive high-mass starless cores.

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

    Science.gov (United States)

    Azuara, J.; Combourieu-Nebout, N.; Lebreton, V.; Mazier, F.; Müller, S. D.; Dezileau, L.

    2015-09-01

    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.

  11. Late Holocene vegetation changes in relation with climate fluctuations and human activity in Languedoc (southern France)

    Science.gov (United States)

    Azuara, J.; Combourieu-Nebout, N.; Lebreton, V.; Mazier, F.; Müller, S. D.; Dezileau, L.

    2015-12-01

    Holocene climate fluctuations and human activity since the Neolithic have shaped present-day Mediterranean environments. Separating anthropogenic effects from climatic impacts to better understand Mediterranean paleoenvironmental changes 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 high-frequency climate variability coincide in time with the rapid climatic events observed 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 sclerophyllous taxa and loss of forest cover result from anthropogenic impact. Classical Antiquity is characterized by a major reforestation event related to the concentration of rural activity 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 the 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.

  12. Solar wind fluctuations at large scale: A comparison between low and high solar activity conditions

    International Nuclear Information System (INIS)

    Bavassano, B.; Bruno, R.

    1991-01-01

    The influence of the Sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU, Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. On the whole, the Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. At scales from 0.5 to 3 days the most important feature is the growth, as the solar wind expansion develops, of strong positive correlations between magnetic and thermal pressures. These structures are progressively built up by the interaction between different wind flows. This effect is more pronounced at low than at high activity. Our findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations

  13. Solar wind fluctuations at large scale - A comparison between low and high solar activity conditions

    Science.gov (United States)

    Bavassano, B.; Bruno, R.

    1991-02-01

    The influence of the sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role-exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. The Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. These findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations.

  14. Fluctuations and symmetries in two-dimensional active gels.

    Science.gov (United States)

    Sarkar, N; Basu, A

    2011-04-01

    Motivated by the unique physical properties of biological active matter, e.g., cytoskeletal dynamics in eukaryotic cells, we set up effective two-dimensional (2d) coarse-grained hydrodynamic equations for the dynamics of thin active gels with polar or nematic symmetries. We use the well-known three-dimensional (3d) descriptions (K. Kruse et al., Eur. Phys. J. E 16, 5 (2005); A. Basu et al., Eur. Phys. J. E 27, 149 (2008)) for thin active-gel samples confined between parallel plates with appropriate boundary conditions to derive the effective 2d constitutive relations between appropriate thermodynamic fluxes and generalised forces for small deviations from equilibrium. We consider three distinct cases, characterised by spatial symmetries and boundary conditions, and show how such considerations dictate the structure of the constitutive relations. We use these to study the linear instabilities, calculate the correlation functions and the diffusion constant of a small tagged particle, and elucidate their dependences on the activity or nonequilibrium drive.

  15. Soft inclusion in a confined fluctuating active gel

    Science.gov (United States)

    Singh Vishen, Amit; Rupprecht, J.-F.; Shivashankar, G. V.; Prost, J.; Rao, Madan

    2018-03-01

    We study stochastic dynamics of a point and extended inclusion within a one-dimensional confined active viscoelastic gel. We show that the dynamics of a point inclusion can be described by a Langevin equation with a confining potential and multiplicative noise. Using a systematic adiabatic elimination over the fast variables, we arrive at an overdamped equation with a proper definition of the multiplicative noise. To highlight various features and to appeal to different biological contexts, we treat the inclusion in turn as a rigid extended element, an elastic element, and a viscoelastic (Kelvin-Voigt) element. The dynamics for the shape and position of the extended inclusion can be described by coupled Langevin equations. Deriving exact expressions for the corresponding steady-state probability distributions, we find that the active noise induces an attraction to the edges of the confining domain. In the presence of a competing centering force, we find that the shape of the probability distribution exhibits a sharp transition upon varying the amplitude of the active noise. Our results could help understanding the positioning and deformability of biological inclusions, e.g., organelles in cells, or nucleus and cells within tissues.

  16. Core Activities Program. TMI-2 Core Receipt and Storage Project Plan

    International Nuclear Information System (INIS)

    Ayers, A.L. Jr.

    1984-12-01

    The TMI-2 Core Receipt and Storage Project is funded by the US Department of Energy and managed by the Technical Support Branch of EG and G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL). As part of the Core Activities Program, this project will include: (a) preparations for receipt and storage of the Three Mile Island Unit 2 core debris at INEL; and (b) receipt and storage operations. This document outlines procedures; project management; safety, environment, and quality; safeguards and security; deliverables; and cost and schedule for the receipt and storage activities at INEL

  17. Buckling of thermally fluctuating spherical shells: Parameter renormalization and thermally activated barrier crossing

    Science.gov (United States)

    Baumgarten, Lorenz; Kierfeld, Jan

    2018-05-01

    We study the influence of thermal fluctuations on the buckling behavior of thin elastic capsules with spherical rest shape. Above a critical uniform pressure, an elastic capsule becomes mechanically unstable and spontaneously buckles into a shape with an axisymmetric dimple. Thermal fluctuations affect the buckling instability by two mechanisms. On the one hand, thermal fluctuations can renormalize the capsule's elastic properties and its pressure because of anharmonic couplings between normal displacement modes of different wavelengths. This effectively lowers its critical buckling pressure [Košmrlj and Nelson, Phys. Rev. X 7, 011002 (2017), 10.1103/PhysRevX.7.011002]. On the other hand, buckled shapes are energetically favorable already at pressures below the classical buckling pressure. At these pressures, however, buckling requires to overcome an energy barrier, which only vanishes at the critical buckling pressure. In the presence of thermal fluctuations, the capsule can spontaneously overcome an energy barrier of the order of the thermal energy by thermal activation already at pressures below the critical buckling pressure. We revisit parameter renormalization by thermal fluctuations and formulate a buckling criterion based on scale-dependent renormalized parameters to obtain a temperature-dependent critical buckling pressure. Then we quantify the pressure-dependent energy barrier for buckling below the critical buckling pressure using numerical energy minimization and analytical arguments. This allows us to obtain the temperature-dependent critical pressure for buckling by thermal activation over this energy barrier. Remarkably, both parameter renormalization and thermal activation lead to the same parameter dependence of the critical buckling pressure on temperature, capsule radius and thickness, and Young's modulus. Finally, we study the combined effect of parameter renormalization and thermal activation by using renormalized parameters for the energy

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

    Science.gov (United States)

    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

    2014-07-04

    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. Copyright © 2014, American Association for the Advancement of Science.

  19. Decrease in scale invariance of activity fluctuations with aging and in patients with suprasellar tumors

    DEFF Research Database (Denmark)

    Joustra, S. D.; Gu, C.; Rohling, J. H.T.

    2018-01-01

    -matched healthy controls (age range 21.0–70.6 years). Spontaneous wrist locomotor activity was measured for 7 days with actigraphy, and detrended fluctuation analysis was applied to assess correlations over a range of time scales from minutes to 24 h. For all the subjects, complex scale-invariant correlations...... scale invariance. Conversely, activity patterns at time scales between 10 and 24 h were significantly more regular than all other time scales, and this was mostly associated with age. In conclusion, scale invariance is degraded in healthy subjects at the ages of >33 year as characterized by attenuation......Motor activity in healthy young humans displays intrinsic fluctuations that are scale-invariant over a wide range of time scales (from minutes to hours). Human postmortem and animal lesion studies showed that the intact function of the suprachiasmatic nucleus (SCN) is required to maintain...

  20. Magnetohydrodynamic behaviour during core transport barrier experiments with ion Bernstein wave heating in PBX-M: I ELMs fluctuations and crash events

    International Nuclear Information System (INIS)

    Sesnic, S.; Kaita, R.; Batha, S.H.

    1998-01-01

    If the ion Bernstein wave (IBW) heating power in an H mode discharge of the PBX-M experiment exceeds a threshold power of about 200 kW, a core transport barrier is created in the central region of the plasma. At lower neutral beam injection (NBI) powers, the core barrier is accompanied by an edge L mode. The high edge localized mode (ELM) repetition frequency (1 kHz) prevents the creation of a strong barrier, so the edge first has to make an H-to-L transition before a strong core transport barrier can be created. At higher NBI powers, the ELM repetition frequency is lowered to less than 200 Hz, which allows the immediate creation of a strong core barrier. Edge localized mode loss, which propagates radially first on a fast (non-diffusive) and then on a slow (diffusive) time-scale all the way to the plasma core, is strongly reduced in the core barrier region. Correlated with the reduced ELM loss, the fluctuations in the core barrier region are also strongly reduced, both during the ELM and during the quite periods between the ELMs. There is strong evidence that the IBW induced poloidal flow shear is responsible for the stabilization of core turbulence and the creation of the core transport barrier. The large perpendicular E x B flow shear component of the measured toroidal velocity in co-injection neutral beam heated discharges seems to be largely cancelled by the ion diamagnetic drift shear produced by large ion pressure gradients in the core barrier region. The value of IBW induced poloidal flow has not been experimentally determined, but its numerical value is found to be a factor of 4 larger than either the toroidal velocity or the ion diamagnetic drift shear components, leaving only IBW induced flow shear as the most probable cause for the turbulence stabilization. The core turbulence suppression and the creation of the core transport barrier is also consistent with expectations from a comparison between the E x B flow shear rate and a rough estimate of the

  1. In-core fuel management activities in China

    International Nuclear Information System (INIS)

    Ruan Keqiang; Chen Renji; Hu Chuanwen

    1990-01-01

    The development of nuclear power in China has reached such a stage that PWR in-core fuel management becomes an urgent problem. At present the main effort is concentrated on solving the Qinshan nuclear power plant and Daya Bay nuclear power plant fuel management problems. For the Qinshan PWR (300 MWe) two packages of in-core fuel management code were developed, one with simplified nodal diffusion method and the other uses advanced Green's function nodal method. Both were used in the PWR core design. With the help of the two code packages first two cycles of the Qinshan PWR core burn-up were calculated. Besides, several research works are under way in the following areas: improvement of the nodal diffusion method and other coarse mesh method in terms of computing speed and accuracy; backward diffusion technique for fuel management application; optimization technique in the fuel loading pattern searching. As for the Daya Bay PWR plant (twin 900 MWe unit), the problem about using what kind of code package for in-core fuel management is still under discussion. In principle the above mentioned code packages are also applicable to it. Besides PWR, in-core fuel management research works are also under way for research reactors, for example, heavy water research reactor and high flux research reactor in some institutes in China. China also takes active participation in international in-core fuel management activities. (author). 19 refs

  2. An experimental test of the fluctuation relation in an active camphor boat system

    Science.gov (United States)

    Paroor, H. M.; Nambiar, N.; Bandi, M. M.

    The Gallavotti-Cohen fluctuation relation (FR) posits a specific symmetry between positive and negative fluctuations in entropy production, or a related quantity (e.g power) for systems in non-equilibrium stationary state. Successful tests in a variety of systems suggest the FR may be more generally applicable than the conditions under which it was originally derived. Systems where the FR fails are therefore valuable for the insight they provide into the FR's general success. It has recently been suggested that ``active matter'' should not satisfy the fluctuation-dissipation theorem or FR. We experimentally test this possibility in a system of active camphor boats, self-propelled by surface tension gradients at air-water interfaces. The boats interact via short-range capillary attraction which competes with long-range surface tension mediated repulsion. Tuning interaction strength with number density, we test the FR through the statistics of power as one goes from a free non-interacting camphor boat, through a few weakly interacting boats to several, strongly interacting boats. We present preliminary results of our experiments and data analysis.

  3. BWR core response to fluctuations in coolant flow and pressure, with implications on noise diagnosis and stability monitoring

    International Nuclear Information System (INIS)

    Blomstrand, J.H.; Andersson, S.A.

    1982-01-01

    Reactor dynamic tests, utilizing sinuosidal oscillations in pressure and recirculation flow, have been conducted in operating BWRs in Sweden and Finland. Test data recorded, as well as recordings of process noise, have been analyzed in terms of dynamic core properties. The results obtained show good qualitative agreement with model predictions of BWR core dynamics. Model studies can often support interpretation of dynamic information obtained from operating plants. Comparisons between model studies, dynamic tests and process noise may also provide improved understanding of test results and noise patterns; in this way it can be demonstrated that some neutron flux noise is caused by noise in coolant flow and steam flow. From reactor test data nd noise recordings, core stability parameters have been evaluated by a number of methods. These have been found to provide essentially the same results. The cores investigated were found to be very stable under normal operating conditions. In special operating points, outside the normal operating range, higher decay ratios may occur. The experience indicates that for BWR cores, operated at decay ratios above quarter damping, the stability parameters may be identified from the oscillatory behavior of the autocorrelation in the time domain of the neutron flux noise

  4. Fluctuation in glacial and interglacial sediment discharge of the River Indus as seen in the core from the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Guptha, M.V.S.; Hashimi, N.H.

    Sediment core from the upper continental slope off Saurashtra Coast has been analysed for CaCO sub(3) and coarse fraction contents in addition to planktonic foraminifera and clay mineralogy. Based on CaCO sub(3) and planktonic foraminiferal data a...

  5. Fluctuating monsoonal precipitation as revealed by foraminiferal variations in a core from shelf regime off Karwar (India)

    Digital Repository Service at National Institute of Oceanography (India)

    Nigam, R.

    in this area. The percentage abundance of C. annectens in the total benthic foraminifera obtained for each sample and plotted against depth in core varied from 0 to 4.88%. In coastal areas, abundance of this species is inversely proportional to freshwater...

  6. Mechano-genetic DNA hydrogels as a simple, reconstituted model to probe the effect of active fluctuations on gene transcription

    Science.gov (United States)

    Nguyen, Dan; Saleh, Omar

    Active fluctuations - non-directed fluctuations attributable, not to thermal energy, but to non-equilibrium processes - are thought to influence biology by increasing the diffusive motion of biomolecules. Dense DNA regions within cells (i.e. chromatin) are expected to exhibit such phenomena, as they are cross-linked networks that continually experience propagating forces arising from dynamic cellular activity. Additional agitation within these gene-encoding DNA networks could have potential genetic consequences. By changing the local mobility of transcriptional machinery and regulatory proteins towards/from their binding sites, and thereby influencing transcription rates, active fluctuations could prove to be a physical means of modulating gene expression. To begin probing this effect, we construct genetic DNA hydrogels, as a simple, reconstituted model of chromatin, and quantify transcriptional output from these hydrogels in the presence/absence of active fluctuations.

  7. [Fluctuations in biophysical measurements as a result of variations in solar activity].

    Science.gov (United States)

    Peterson, T F

    1995-01-01

    A theory is proposed to explain variations in the net electrical charge of biological substances at the Earth's surface. These are shown to occur in association with changes in the solar wind and geomagnetic field. It is suggested that a liquid dielectric's net volume charge will imitate pH effects, influence chemical reaction rates, and alter ion transfer mechanisms in biophysical systems. An experiment is described which measures dielectric volume charge, or non-neutrality, to allow correlation of this property with daily, 28-day, and 11-year fluctuation patterns in geophysical and satellite data associated with solar activity and the interplanetary magnetic field.

  8. Some activities at CEA related to behaviour of core internals

    International Nuclear Information System (INIS)

    Petrequin, P.

    1998-01-01

    Eighteen transparencies where presented, elaborating some activities at CEA related to behaviour of core internals. After some introduction, ten of the transparencies are essentially a copy of the table of contents of the AMES report no. 11 (report no: EUR 17694 EN). The remaining 6 foils concerned themselves with irradiation experiments in test reactors, namely the IDAHO, CASIMIR and ALEXANDRA experiments

  9. Ongoing activity in temporally coherent networks predicts intra-subject fluctuation of response time to sporadic executive control demands.

    Science.gov (United States)

    Nozawa, Takayuki; Sugiura, Motoaki; Yokoyama, Ryoichi; Ihara, Mizuki; Kotozaki, Yuka; Miyauchi, Carlos Makoto; Kanno, Akitake; Kawashima, Ryuta

    2014-01-01

    Can ongoing fMRI BOLD signals predict fluctuations in swiftness of a person's response to sporadic cognitive demands? This is an important issue because it clarifies whether intrinsic brain dynamics, for which spatio-temporal patterns are expressed as temporally coherent networks (TCNs), have effects not only on sensory or motor processes, but also on cognitive processes. Predictivity has been affirmed, although to a limited extent. Expecting a predictive effect on executive performance for a wider range of TCNs constituting the cingulo-opercular, fronto-parietal, and default mode networks, we conducted an fMRI study using a version of the color-word Stroop task that was specifically designed to put a higher load on executive control, with the aim of making its fluctuations more detectable. We explored the relationships between the fluctuations in ongoing pre-trial activity in TCNs and the task response time (RT). The results revealed the existence of TCNs in which fluctuations in activity several seconds before the onset of the trial predicted RT fluctuations for the subsequent trial. These TCNs were distributed in the cingulo-opercular and fronto-parietal networks, as well as in perceptual and motor networks. Our results suggest that intrinsic brain dynamics in these networks constitute "cognitive readiness," which plays an active role especially in situations where information for anticipatory attention control is unavailable. Fluctuations in these networks lead to fluctuations in executive control performance.

  10. Harvesting thermal fluctuations: Activation process induced by a nonlinear chain in thermal equilibrium

    International Nuclear Information System (INIS)

    Reigada, Ramon; Sarmiento, Antonio; Romero, Aldo H.; Sancho, J. M.; Lindenberg, Katja

    2000-01-01

    We present a model in which the immediate environment of a bistable system is a molecular chain which in turn is connected to a thermal environment of the Langevin form. The molecular chain consists of masses connected by harmonic or by anharmonic springs. The distribution, intensity, and mobility of thermal fluctuations in these chains is strongly dependent on the nature of the springs and leads to different transition dynamics for the activated process. Thus, all else (temperature, damping, coupling parameters between the chain and the bistable system) being the same, the hard chain may provide an environment described as diffusion-limited and more effective in the activation process, while the soft chain may provide an environment described as energy-limited and less effective. The importance of a detailed understanding of the thermal environment toward the understanding of the activation process itself is thus highlighted. (c) 2000 American Institute of Physics

  11. Nonequilibrium phase transitions, fluctuations and correlations in an active contractile polar fluid.

    Science.gov (United States)

    Gowrishankar, Kripa; Rao, Madan

    2016-02-21

    We study the patterning, fluctuations and correlations of an active polar fluid consisting of contractile polar filaments on a two-dimensional substrate, using a hydrodynamic description. The steady states generically consist of arrays of inward pointing asters and show a continuous transition from a moving lamellar phase, a moving aster street, to a stationary aster lattice with no net polar order. We next study the effect of spatio-temporal athermal noise, parametrized by an active temperature TA, on the stability of the ordered phases. In contrast to its equilibrium counterpart, we find that the active crystal shows true long range order at low TA. On increasing TA, the asters dynamically remodel, concomitantly we find novel phase transitions characterized by bond-orientational and polar order upon "heating".

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

    DEFF Research Database (Denmark)

    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....... If the spikes arrive at random times the changes in synaptic conductance are therefore stochastic and rapid during intense network activity. In comparison, sub-threshold intrinsic conductances vary smoothly in time. In the present study this discrepancy is investigated using two conductance-based models: a (1...... 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...

  13. Investigation of the fluctuation range of activity concentrations of natural radionuclides in surface air

    International Nuclear Information System (INIS)

    Winkler, R.; Hoetzl, H.

    1985-01-01

    Daily and seasonal concentration fluctuations of short-lived Rn fission products observed and the seasonal and long-term concentration fluctuations of Pb-210, Po-210, Ra-226, Ra-228, K-40 and Be-7 are discussed; the frequency distributions of the concentration values are illustrated. For a period of several years, the following mean values of activity concentrations were found (μBq/m 3 ): Pb-210: 600 Ra-226: 1.3 K-40: 13, Po-210: 33 Ra-228: 0.5 Be-7: 3700. In accordance with the origin from the soil, there is a significant correlation between the respective activity concentration and air-borne dust concentration for Ra-226, Ra-228, and K-40. The investigation revealed a most significant correlation between the Pb-210 concentration and the stagnancy index, the latter being a measure for the degree of blending of the surface layer of air. The resuspension factors found for Ra-226 and Pb-210 are discussed. (orig./HP) [de

  14. Thermal fluctuations in perpendicular recording media: New methodology for estimation of activation moment

    International Nuclear Information System (INIS)

    Mamiya, H; Oba, Y; Ohnuma, M; Hagiya, H; Oku, T; Suzuki, J; Yokoyama, M; Nishihara, Y; Katayama, T; Awano, H; Koda, T

    2011-01-01

    In nanoparticulate films with perpendicular magnetic anisotropy, a large demagnetizing field almost compensates for the experimentally designed change in the magnetic field applied parallel to the film normal. We propose a new method based on field-cycling to eliminate the uncertainty in the demagnetizing response from the analysis of the activation volume of the reversal or magnetic activation moment in such films. In this method, the applied field induced variation in the magnetic relaxation rate is measured before the effect of the demagnetizing field becomes dominant. We also discuss an analogical thermal-cycling method to clarify the temperature dependence of the barrier height for magnetization reversal in a magnetic field. We apply these methods to a Co 74 Pt 16 Cr 10 -SiO 2 nanoparticulate film as an example. The results demonstrate that these methods are useful for studying thermal fluctuations in perpendicular recording media.

  15. A Common Definition of the System Operators' Core Activities

    International Nuclear Information System (INIS)

    2006-02-01

    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

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

    Science.gov (United States)

    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.

  17. Space potential fluctuations during MHD activities in the Compact Helical System (CHS)

    International Nuclear Information System (INIS)

    Iguchi, H.; Fujisawa, A.; Crowley, T.P.

    1998-02-01

    Local space potential fluctuations have been measured during MHD activities in a low-beta NBI heated plasma in the Compact Helical System (CHS) by the use of a heavy ion beam probe (HIBP). Two types of MHD modes with accompanying potential oscillations are observed. One appears in periodic bursts with relatively low frequency (< 40 kHz) and large amplitude (20-40 volts), and is localized around the q=2 surface (average minor radius ρ ∼ 0.7). The other appears in continuous and coherent oscillation with higher frequency (105-125 kHz) and smaller amplitude (∼5 volts). This oscillation also has spatial structure. Possible interpretation for the space potential oscillations is presented. (author)

  18. Relations between chemical species distribution and the fluctuating activity of Vulcano (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Martini, M.; Legittimo, P.C.

    1984-09-01

    Five years of systematic observation of the fumaroles of Vulcano have permitted the detection of some compositional trends coincident with a fluctuation in temperature. A gradual decrease of CO/sub 2/, H/sub 2/S+SO/sup 2/, HF was observed with the lowering of temperature, while HCl slightly increased. These physical-chemical characteristics of the system are not readily explained as simply produced by different stages in magma degassing, and the previous hypothesis of the insignificant influence of a brackish aquifer on the fumaroles still appears a reliable working model. R-mode factor analysis allowed the differentiated role of chemical species to be distinguished for which different genetic processes can be derived. The ratios HF/HCl and SO/sub 2//H/sub 2/S are taken as indicators of the changing activity of the system, and also the available data for Usu (Japan) and Mount St. Helens (USA) are considered.

  19. Research and application of active hollow core slabs in building systems for utilizing low energy sources

    International Nuclear Information System (INIS)

    Xu, Xinhua; Yu, Jinghua; Wang, Shengwei; Wang, Jinbo

    2014-01-01

    Highlights: • A review on the development and modeling of active hollow core slab is presented. • The applications and performance evaluation of the slab in building are reviewed. • Finite element or finite difference method is often used in multidimensional model. • Performance evaluations of building using active slabs for ventilation are limited. • More works on the active hollow core slab are worthwhile. - Abstract: The society and the building professionals have paid much concern in recent years on building energy efficiency and the development and applications of low energy technologies for buildings/green buildings allowing the elimination, or at least reduction of dependence on electricity or fossil fuel while maintaining acceptable indoor environment. Utilizations of favorable diurnal temperature difference and ground thermal source for air conditioning are among these low energy technologies. Utilization of the hollow cores in the prefabricated slab for ventilation and the mass of the slab for thermal storage is widely used in building systems in Europe by exploiting the low energy source of the ambient air. These hollow core slabs aim at enlarging the heat transfer surface between the slab mass and the air in the core, which permits substantial heat flows even for relatively small temperature differences. This, in turn, allows the use of low energy cooling or heating sources, such as the ground, outside air or recovered process heat. In this paper, we present a comprehensive review of the research and application of active hollow core slabs in building systems for utilizing low energy sources. The principle and development of active hollow core slabs in building systems for leveling the indoor temperature fluctuation by ventilation air passing the cores are described. Calculation models of the active hollow core concrete slab as well as the practical applications and performance evaluation of the slab applied in building systems for air

  20. Release of fission and activation products during LWR core meltdown

    International Nuclear Information System (INIS)

    Albrecht, H.; Matschoss, V.; Wild, H.

    1978-01-01

    Experiments are described by which activity release fractions and aerosol characteristics were investigated for various core melting conditions. Samples of corium and fissium were heated by induction to temperatures of 2800 0 C under air, argon and steam. Release values are presented for Cr, Mn, Fe, Co, Se, Zr, Mo, Cd, Sn, Sb, Te, J, Cs and U. The deposition behaviour of the released products was found to depend strongly on the volatility and on the gas flow rate. Preliminary results of additional measurements indicate that the size distribution of the aerosol particles is trimodal. (author)

  1. Resolution of lead-210 chronologies in lake sediments: problems of mid-core fluctuations in lead-210/radium-226 ratios

    Energy Technology Data Exchange (ETDEWEB)

    Haworth, R. [New England Univ., Armidale, NSW (Australia). Dept. of Geography; Heijnis, H. [Australian Inst. of Nuclear Science and Engineering, Lucas Heights, NSW (Australia)

    1997-12-31

    With a range in excess of 150 years under optimum conditions, lead-210 dating represents a valuable tool for studying recent human impacts on the environment, particularly the effects of European settlement in Australia. It is therefore also useful for establishing the start of the pre-European record in a sediment profile. Despite these advantages, there are some unresolved problems that prevent the full potential of an atmospherically-derived lead-210 profile being extended as far into the past as the activity signal allows. lead 210 has a half-life of 22.26 years, and a capacity to precipitate and be adsorbed by terrestrial material, particularly lake and marine sediments. This out-of-phase (or unsupported) lead-210 thus returns to a specific terrigenous location where it is added to the lead- 210 formed continuously in situ from the local radium-226 (equivalent to supported lead-210). Dating is based on the measurement of the decline of this unsupported lead-210 against the equilibrium ratio of in situ lead-210/radium-226. Paper no. 13; Extended abstract. 2 refs., 1 fig.

  2. Resolution of lead-210 chronologies in lake sediments: problems of mid-core fluctuations in lead-210/radium-226 ratios

    International Nuclear Information System (INIS)

    Haworth, R.

    1997-01-01

    With a range in excess of 150 years under optimum conditions, lead-210 dating represents a valuable tool for studying recent human impacts on the environment, particularly the effects of European settlement in Australia. It is therefore also useful for establishing the start of the pre-European record in a sediment profile. Despite these advantages, there are some unresolved problems that prevent the full potential of an atmospherically-derived lead-210 profile being extended as far into the past as the activity signal allows. lead 210 has a half-life of 22.26 years, and a capacity to precipitate and be adsorbed by terrestrial material, particularly lake and marine sediments. This out-of-phase (or unsupported) lead-210 thus returns to a specific terrigenous location where it is added to the lead- 210 formed continuously in situ from the local radium-226 (equivalent to supported lead-210). Dating is based on the measurement of the decline of this unsupported lead-210 against the equilibrium ratio of in situ lead-210/radium-226

  3. Multichannel detrended fluctuation analysis reveals synchronized patterns of spontaneous spinal activity in anesthetized cats.

    Directory of Open Access Journals (Sweden)

    Erika E Rodríguez

    Full Text Available 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 study we present a multichannel version of the detrended fluctuation analysis method (mDFA to analyze the correlation dynamics of spontaneous spinal activity (SSA from time series analysis. This method together with the classical detrended fluctuation analysis (DFA were used to find out whether the SSA recorded in one or several segments in the spinal cord of the anesthetized cat occurs either in a random or in an organized manner. Our results are consistent with a non-random organization of the sets of neurons involved in the generation of spontaneous cord dorsum potentials (CDPs recorded either from one lumbar segment (DFA-α mean = 1.04[Formula: see text]0.09 or simultaneously from several lumbar segments (mDFA-α mean = 1.01[Formula: see text]0.06, where α = 0.5 indicates randomness while α = 0.5 indicates long-term correlations. To test the sensitivity of the mDFA method we also examined the effects of small spinal lesions aimed to partially interrupt connectivity between neighboring lumbosacral segments. We found that the synchronization and correlation between the CDPs recorded from the L5 and L6 segments in both sides of the spinal cord were reduced when a lesion comprising the left dorsal quadrant was performed between the segments L5 and L6 (mDFA-[Formula: see text] = 0.992 as compared to initial conditions mDFA-α = 1.186. The synchronization and correlation were reduced even further after a similar additional right spinal lesion (mDFA-α = 0

  4. Fluctuation - a common but neglected pattern of physical activity behaviour: An exploratory review of studies in recent 20 years.

    Science.gov (United States)

    Shang, Borui; Duan, Yanping; Huang, Wendy Yajun; Brehm, Walter

    2018-03-01

    Regular physical activity (PA) is beneficial for physical and psychological well-being, yet many people do not achieve these health benefits due to irregular PA participation which is also known as fluctuation. Limited attention has been given to the phenomenon of fluctuation in the PA behaviour literature. The aim of this review was to explore and to map definitions, measurements, behavioural evidence, and factors related to PA fluctuation. Eligible studies were initially identified by a systematic search of articles conducted in four databases: Scopus, PubMed, PsycINFO, and SPORTDiscus between January 1996 and March 2016. Inclusion and exclusion criteria were set to check the eligibility of all articles. Additional articles were included by manual searching and expert recommendation. Fifteen articles were finally included. Definitions of fluctuation are understood from two perspectives, either as a stage in the process of behaviour change, or as a particular PA phenomenon consisting of lapse and readoption. Common features were extracted: behavioural irregularity, high risk of drop-out, intention and readiness for PA, low automaticity, and limited self-regulation. Furthermore, fluctuation identification was summarised in three approaches such as stage algorithm, self-identified PA lapse and readoption, and prospective within-person variation in meeting the PA guidelines. Regarding the empirical evidence, this review found that people in PA fluctuation were significantly distinct from those in preparation and maintenance of PA behavioural performance, as well as distinct in psychosocial features. Notwithstanding the limitations, this review has provided valuable insight into the phenomenon of PA fluctuation.

  5. Human migration activities drive the fluctuation of ARGs : Case study of landfills in Nanjing, eastern China

    OpenAIRE

    Sun, Mingming; Ye, Mao; Schwab, Arthur P; Li, Xu; Wan, Jinzhong; Wei, Zhong; Wu, Jun; Friman, Ville-Petri; Liu, Kuan; Tian, Da; Liu, Manqiang; Li, Huixin; Hu, Feng; Jiang, Xin

    2016-01-01

    Landfills are perfect sites to study the effect of human migration on fluctuation of antibiotic resistance genes (ARGs) as they are the final destination of municipal waste. For example, large-scale human migration during the holidays is often accompanied by changes in waste dumping having potential effects on ARG abundance. Three landfills were selected to examine fluctuation in the abundance of fifteen ARGs and Intl1 genes for 14 months in Nanjing, eastern China. Mass human migration, the a...

  6. Investigation of activity release during light water reactor core meltdown

    International Nuclear Information System (INIS)

    Albrecht, H.; Matschoss, V.; Wild, H.

    1978-01-01

    A test facility was developed for the determination of activity release and of aerosol characteristics under realistic light water reactor core melting conditions. It is composed of a high-frequency induction furnace, a ThO 2 crucible system, and a collection apparatus consisting of membrane and particulate filters. Thirty-gram samples of a representative core material mixture (corium) were melted under air, argon, or steam at 0.8 to 2.2 bar. In air at 2700 0 C, for example, the relative release was 0.4 to 0.7% for iron, chromium, and cobalt and 4 to 11% for tin, antimony, and manganese. Higher release values of 20 to 40% at lower temperatures (2150 0 C, air) were found for selenium, cadmium, tellurium, and cesium. The size distribution of the aerosol particles was trimodal with maxima at diameters of 0.17, 0.30, and 0.73 μm. The result of a qualitative x-ray microanalysis was that the main elements of the melt were contained in each aerosol particle. Further investigations will include larger melt masses and the additional influence of concrete on the release and aerosol behavior

  7. Seven-core active fibre for application in telecommunication satellites

    Science.gov (United States)

    Filipowicz, Marta; Napierała, Marek; Murawski, Michał; Ostrowski, Łukasz; Szostkiewicz, Łukasz; Szymański, Michał; Tenderenda, Tadeusz; Anders, Krzysztof; Piramidowicz, Ryszard; Wójcik, Grzegorz; Makara, Mariusz; Poturaj, Krzysztof; Mergo, Paweł; Nasiłowski, Tomasz

    2015-12-01

    The use of optical elements and other photonic components makes it possible to overcome telecommunication satellite's bottleneck problems such as size and weight reduction. Despite the unquestionable potential of such elements, nowadays they are not widely used in systems operating in space. This is due to many factors, including the fact that space radiation has disruptive influence on optical fibre. Namely it introduces additional radiation induced attenuation (RIA) that significantly lowers efficiency of optical fibre based systems. However, there is a possibility to produce radiation-hardened (rad-hard) components. One of them is seven core erbium-doped active fibre (MC-EDF) for fibre amplifiers in satellites that we have been developing. In this paper we present a detailed description of seven core structure design as well as experimental results. We report that average gain of 20 dB in C-band with noise figure of 5.8 dB was obtained. We also confirmed that low crosstalk value for a multicore fibre amplifier based on our fibre can be achieved.

  8. Daily fluctuation of hepatic P450 monooxygenase activities in male rats is controlled by the suprachiasmatic nucleus but remains unaffected by adrenal hormones.

    Science.gov (United States)

    Furukawa, T; Manabe, S; Watanabe, T; Sehata, S; Sharyo, S; Okada, T; Mori, Y

    1999-09-01

    Hepatic P450 monooxygenase activities, which strongly influence the efficacy and/or toxicity of drugs, are known to fluctuate daily. We also know that the P450 activities assessed by measurement of 7-alkoxycoumarin O-dealkylase (ACD) activities fluctuate daily, with apparently high values during the dark period in male rats. However, there is little knowledge about the factors that regulate daily fluctuation of P450 monooxygenase activities. In the present study using rats, we induced lesions in the suprachiasmatic nucleus (SCN) of the brain, the known site of the body's internal clock, and examined the effects on the daily fluctuation of the ACD activities to clarify the relationship between the SCN and the daily fluctuation of P450 monooxygenase activities. In addition, adrenalectomy was performed to re-evaluate the influence of adrenal hormones on the P450 activities. Our results indicated that daily fluctuations of the hepatic ACD activities were completely eliminated in the SCN-lesioned rats. However, the ACD activities in the adrenalectomized rats showed apparent daily fluctuations with high values during the dark period and low values during the light period. Therefore, this study demonstrated that the daily fluctuation of the hepatic P450 monooxygenase activities in male rats is controlled by the SCN but remains unaffected by the adrenal hormones.

  9. Human migration activities drive the fluctuation of ARGs: Case study of landfills in Nanjing, eastern China.

    Science.gov (United States)

    Sun, Mingming; Ye, Mao; Schwab, Arthur P; Li, Xu; Wan, Jinzhong; Wei, Zhong; Wu, Jun; Friman, Ville-Petri; Liu, Kuan; Tian, Da; Liu, Manqiang; Li, Huixin; Hu, Feng; Jiang, Xin

    2016-09-05

    Landfills are perfect sites to study the effect of human migration on fluctuation of antibiotic resistance genes (ARGs) as they are the final destination of municipal waste. For example, large-scale human migration during the holidays is often accompanied by changes in waste dumping having potential effects on ARG abundance. Three landfills were selected to examine fluctuation in the abundance of fifteen ARGs and Intl1 genes for 14 months in Nanjing, eastern China. Mass human migration, the amount of dumped waste and temperature exerted the most significant effects on bimonthly fluctuations of ARG levels in landfill sites. As a middle-sized cosmopolitan city in China, millions of college students and workers migrate during holidays, contributing to the dramatic increases in waste production and fluctuation in ARG abundances. In line with this, mass migration explained most of the variation in waste dumping. The waste dumping also affected the bioaccessibility of mixed-compound pollutants that further positively impacted the level of ARGs. The influence of various bioaccessible compounds on ARG abundance followed the order: antibiotics>nutrients>metals>organic pollutants. Concentrations of bioaccessible compounds were more strongly correlated with ARG levels compared to total compound concentrations. Improved waste classification and management strategies could thus help to decrease the amount of bioaccessible pollutants leading to more effective control for urban ARG dissemination. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. The effects of therapeutic hip exercise with abdominal core activation on recruitment of the hip muscles.

    Science.gov (United States)

    Chan, Mandy Ky; Chow, Ka Wai; Lai, Alfred Ys; Mak, Noble Kc; Sze, Jason Ch; Tsang, Sharon Mh

    2017-07-21

    Core stabilization has been utilized for rehabilitation and prevention of lower limb musculoskeletal injuries. Previous studies showed that activation of the abdominal core muscles enhanced the hip muscle activity in hip extension and abduction exercises. However, the lack of the direct measurement and quantification of the activation level of the abdominal core muscles during the execution of the hip exercises affect the level of evidence to substantiate the proposed application of core exercises to promote training and rehabilitation outcome of the hip region. The aim of the present study was to examine the effects of abdominal core activation, which is monitored directly by surface electromyography (EMG), on hip muscle activation while performing different hip exercises, and to explore whether participant characteristics such as gender, physical activity level and contractile properties of muscles, which is assessed by tensiomyography (TMG), have confounding effect to the activation of hip muscles in enhanced core condition. Surface EMG of bilateral internal obliques (IO), upper gluteus maximus (UGMax), lower gluteus maximus (LGMax), gluteus medius (GMed) and biceps femoris (BF) of dominant leg was recorded in 20 young healthy subjects while performing 3 hip exercises: Clam, side-lying hip abduction (HABD), and prone hip extension (PHE) in 2 conditions: natural core activation (NC) and enhanced core activation (CO). EMG signals normalized to percentage of maximal voluntary isometric contraction (%MVIC) were compared between two core conditions with the threshold of the enhanced abdominal core condition defined as >20%MVIC of IO. Enhanced abdominal core activation has significantly promoted the activation level of GMed in all phases of clam exercise (P recruitment in Clam, HABD and PHE exercises, and this enhancement is correlated with higher physical activity and stiffer hip muscle. Our results suggest the potential application of abdominal core activation for

  11. Experimental and theoretical evidence for fluctuation driven activations in an excitable chemical system

    Science.gov (United States)

    Hastings, Harold; Sobel, Sabrina; Field, Richard; Minchenberg, Scott; Spinelli, Nicole; Zauderer, Keith

    2011-03-01

    An excitable medium is a system in which small perturbations die out, but sufficiently large perturbations generate large ``excitations.'' Biological examples include neurons and the heart; the latter supports waves of excitation normally generated by the sinus node, but occasionally generated by other mechanisms. The ferroin-catalyzed Belousov-Zhabotinsky reaction is the prototype chemical excitable medium. We present experimental and theoretical evidence for that random fluctuations can generate excitations in the Belousov-Zhabothinsky reaction. Although the heart is significantly different, there are some scaling analogies. This material is based upon work supported by the Department of Energy under Award Number DE-FG02-08ER64623.

  12. Hepatitis C virus core protein potentiates proangiogenic activity of hepatocellular carcinoma cells.

    Science.gov (United States)

    Shao, Yu-Yun; Hsieh, Min-Shu; Wang, Han-Yu; Li, Yong-Shi; Lin, Hang; Hsu, Hung-Wei; Huang, Chung-Yi; Hsu, Chih-Hung; Cheng, Ann-Lii

    2017-10-17

    Increased angiogenic activity has been demonstrated in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC), but the mechanism was unclear. To study the role of HCV core protein, we used tube formation and Matrigel plug assays to assess the proangiogenic activity of an HCC cell line, HuH7, and 2 of its stable clones-HuH7-core-high and HuH7-core-low, with high and low HCV core protein expression, respectively. In both assays, HuH7-core-high and HuH7-core-low cells dose-dependently induced stronger angiogenesis than control cells. HuH7 cells with HCV core protein expression showed increased mRNA and protein expression of vascular endothelial growth factor (VEGF). VEGF inhibition by bevacizumab reduced the proangiogenic activity of HuH7-core-high cells. The promotor region of VEGF contains the binding site of activator protein-1 (AP-1). Compared with controls, HuH7-core-high cells had an increased AP-1 activity and nuclear localization of phospho-c-jun. AP-1 inhibition using either RNA knockdown or AP-1 inhibitors reduced the VEGF mRNA expression and the proangiogenic activity of HuH7-core-high cells. Among 131 tissue samples from HCC patients, HCV-related HCC revealed stronger VEGF expression than did hepatitis B virus-related HCC. In conclusion, increased VEGF expression through AP-1 activation is a crucial mechanism underlying the proangiogenic activity of the HCV core protein in HCC cells.

  13. Determination of heavy metals and other elements by Neutron Activation Analysis in sediment cores of laguna Mar Chiquita (Cordoba, Argentina)

    International Nuclear Information System (INIS)

    Larizzatti, Flavio Eduardo

    2001-01-01

    Laguna Mar Chiquita is one of the largest water bodies of South America. It is a big lake of saline waters, and its geographic localization is SOMS' S, 62 deg 30' W, about 150 km Northwest of Cordoba, Argentina. Due to its large variability of hydrological budget, surface and water levels produced periods of low stands (LLP) and high stands (HLP). This fluctuation of water level also produces substantial changes in the water salinity. The principal tributary of the Laguna Mar Chiquita is Dulce River and also receives water from two other rivers: Suquia and Xanaes. The Suquia River drains in a small satellite lake, the Laguna del Plata. The purpose of the present work was to investigate the sediment composition of the Laguna Mar Chiquita (2 sediment cores) and del Plata (one sediment core) by using Neutron Activation Analysis (NAA) technique. The three 60 cm long sediment cores, sliced each 2 cm, were analyzed and 26 elements were determined (As, Ba, Br, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Na, Nd, Rb, Sb, Sc, Se, Sm, Ta, Tb, Th, U, Yb, Zn e Zr). Other complementary techniques were utilized: macro elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Ti) were determined by X-ray fluorescence, and the mineralogical composition of the sediments was determined by X-ray diffraction. The results obtained did not show any indication of anthropic contribution in the sediment composition, and concentration of the majority of the elements analyzed is uniform along the entire profile of the analyzed core. Statistical analysis of elemental concentrations (Cluster Analysis) reflects that in Laguna del Plata the fine fractions of the sediments is dominated by detrital minerals, while in the Laguna Mar Chiquita, the neo formed minerals are the principal components. In both lakes, it was possible to identify compositional variations in the sediment segments, which may correspond to temporal fluctuations in the sedimentation conditions. The statistical analysis associated to sedimentation

  14. Determination of activation parameters for the core transformation of the screw dislocation in silicon

    International Nuclear Information System (INIS)

    Guénolé, J; Godet, J; Pizzagalli, L

    2010-01-01

    The non-dissociated screw dislocation in a model covalent material like silicon is known to exist in three possible stable core configurations. We performed calculations combining the nudged elastic band technique and a semi-empirical description in order to determine mechanisms and activation parameters for transforming one core into another. Our results showed that a glide core is necessarily reconstructed, since the energy barrier for reconstruction is easily overcome by thermal activation. Conversely, a transformation between a shuffle and a glide core appears unlikely at low temperature, which raises questions about the existence of the double-period glide configuration

  15. Carbon Dioxide Fluctuations Are Associated with Changes in Cerebral Oxygenation and Electrical Activity in Infants Born Preterm.

    Science.gov (United States)

    Dix, Laura Marie Louise; Weeke, Lauren Carleen; de Vries, Linda Simone; Groenendaal, Floris; Baerts, Willem; van Bel, Frank; Lemmers, Petra Maria Anna

    2017-08-01

    To evaluate the effects of acute arterial carbon dioxide partial pressure changes on cerebral oxygenation and electrical activity in infants born preterm. This retrospective observational study included ventilated infants born preterm with acute fluctuations of continuous end-tidal CO 2 (etCO 2 ) as a surrogate marker for arterial carbon dioxide partial pressure, during the first 72 hours of life. Regional cerebral oxygen saturation and fractional tissue oxygen extraction were monitored with near-infrared spectroscopy. Brain activity was monitored with 2-channel electroencephalography. Spontaneous activity transients (SATs) rate (SATs/minute) and interval between SATs (in seconds) were calculated. Ten-minute periods were selected for analysis: before, during, and after etCO 2 fluctuations of ≥5  mm Hg. Thirty-eight patients (mean ± SD gestational age of 29 ± 1.8 weeks) were included, with 60 episodes of etCO 2 increase and 70 episodes of etCO 2 decrease. During etCO 2 increases, brain oxygenation increased (regional cerebral oxygen saturation increased, fractional tissue oxygen extraction decreased; P carbon dioxide partial pressure that may be harmful to the neonatal brain. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. The Relationship of Core Strength and Activation and Performance on Three Functional Movement Screens.

    Science.gov (United States)

    Johnson, Caleb D; Whitehead, Paul N; Pletcher, Erin R; Faherty, Mallory S; Lovalekar, Mita T; Eagle, Shawn R; Keenan, Karen A

    2018-04-01

    Johnson, CD, Whitehead, PN, Pletcher, ER, Faherty, MS, Lovalekar, MT, Eagle, SR, and Keenan, KA. The relationship of core strength and activation and performance on three functional movement screens. J Strength Cond Res 32(4): 1166-1173, 2018-Current measures of core stability used by clinicians and researchers suffer from several shortcomings. Three functional movement screens appear, at face-value, to be dependent on the ability to activate and control core musculature. These 3 screens may present a viable alternative to current measures of core stability. Thirty-nine subjects completed a deep squat, trunk stability push-up, and rotary stability screen. Scores on the 3 screens were summed to calculate a composite score (COMP). During the screens, muscle activity was collected to determine the length of time that the bilateral erector spinae, rectus abdominis, external oblique, and gluteus medius muscles were active. Strength was assessed for core muscles (trunk flexion and extension, trunk rotation, and hip abduction and adduction) and accessory muscles (knee flexion and extension and pectoralis major). Two ordinal logistic regression equations were calculated with COMP as the outcome variable, and: (a) core strength and accessory strength, (b) only core strength. The first model was significant in predicting COMP (p = 0.004) (Pearson's Chi-Square = 149.132, p = 0.435; Nagelkerke's R-Squared = 0.369). The second model was significant in predicting COMP (p = 0.001) (Pearson's Chi-Square = 148.837, p = 0.488; Nagelkerke's R-Squared = 0.362). The core muscles were found to be active for most screens, with percentages of "time active" for each muscle ranging from 54-86%. In conclusion, performance on the 3 screens is predicted by core strength, even when accounting for "accessory" strength variables. Furthermore, it seems the screens elicit wide-ranging activation of core muscles. Although more investigation is needed, these screens, collectively, seem to be a good

  17. HCV core protein induces hepatic lipid accumulation by activating SREBP1 and PPARγ

    International Nuclear Information System (INIS)

    Kim, Kook Hwan; Hong, Sung Pyo; Kim, KyeongJin; Park, Min Jung; Kim, Kwang Jin; Cheong, JaeHun

    2007-01-01

    Hepatic steatosis is a common feature in patients with chronic hepatitis C virus (HCV) infection. HCV core protein plays an important role in the development of hepatic steatosis in HCV infection. Because SREBP1 (sterol regulatory element binding protein 1) and PPARγ (peroxisome proliferators-activated receptor γ) are involved in the regulation of lipid metabolism of hepatocyte, we sought to determine whether HCV core protein may impair the expression and activity of SREBP1 and PPARγ. In this study, it was demonstrated that HCV core protein increases the gene expression of SREBP1 not only in Chang liver, Huh7, and HepG2 cells transiently transfected with HCV core protein expression plasmid, but also in Chang liver-core stable cells. Furthermore, HCV core protein enhanced the transcriptional activity of SREBP1. In addition, HCV core protein elevated PPARγ transcriptional activity. However, HCV core protein had no effect on PPARγ gene expression. Finally, we showed that HCV core protein stimulates the genes expression of lipogenic enzyme and fatty acid uptake associated protein. Therefore, our finding provides a new insight into the mechanism of hepatic steatosis by HCV infection

  18. Determination of the neutron activation profile of core drill samples by gamma-ray spectrometry.

    Science.gov (United States)

    Gurau, D; Boden, S; Sima, O; Stanga, D

    2018-04-01

    This paper provides guidance for determining the neutron activation profile of core drill samples taken from the biological shield of nuclear reactors using gamma spectrometry measurements. Thus, it provides guidance for selecting a model of the right form to fit data and using least squares methods for model fitting. The activity profiles of two core samples taken from the biological shield of a nuclear reactor were determined. The effective activation depth and the total activity of core samples along with their uncertainties were computed by Monte Carlo simulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Linear variable differential transformer sensor using glass-covered amorphous wires as active core

    International Nuclear Information System (INIS)

    Chiriac, H.; Hristoforou, E.; Neagu, Maria; Pieptanariu, M.

    2000-01-01

    Results concerning linear variable differential transformer (LVDT) displacement sensor using as movable core glass-covered amorphous wires are presented. The LVDT response is linear for a displacement of the movable core up to about 14 mm, with an accuracy of 1 μm. LVDT using glass-covered amorphous wire as an active core presents a high sensitivity and good mechanical and corrosion resistance

  20. [Amplitude Changes of Low Frequency Fluctuation in Brain Spontaneous Nervous Activities Induced by Needling at Hand Taiyin Lung Channel].

    Science.gov (United States)

    Zhou, You-long; Su, Cheng-guo; Liu, Shou-fang; Jin, Xiang-yu; Duan, Yan-li; Chen, Xiao-yan; Zhao, Shu-hua; Wang, Quan-liang; Dang, Chang-lin

    2016-05-01

    To observe amplitude changes of low frequency fluctuation in brain spontaneous nervous activities induced by needling at Hand Taiyin Lung Channel, and to preliminarily explore the possible brain function network of Hand Taiyin Lung Channel. By using functional magnetic resonance imaging (fMRI), 16 healthy volunteers underwent resting-state scanning (R1) and scanning with retained acupuncture at Hand Taiyin Lung Channel (acupuncture, AP). Data of fMRI collected were statistically calculated using amplitude of low frequency fluctuations (ALFF). Under R1 significantly enhanced ALFF occurred in right precuneus, left inferior parietal lobule, bilateral superior temporal gyrus, bilateral middle frontal gyrus, left superior frontal gyrus, left inferior frontal gyrus, left medial frontal gyrus. Under AP significantly enhanced ALFF occurred in right precuneus, bilateral superior frontal gyrus, cerebellum, bilateral middle frontal gyrus, right medial frontal gyrus, and so on. Compared with R1, needing at Hand Taiyin Lung Channel could significantly enhance ALFF in right gyrus subcallosum and right inferior frontal gyrus. Significant decreased ALFF appeared in right postcentral gyrus, left precuneus, left superior temporal gyrus, left middle temporal gyrus, and so on. Needing at Hand Taiyin Lung Channel could significantly change fixed activities of cerebral cortex, especially in right subcallosal gyrus, right inferior frontal gyrus, and so on.

  1. Deep bore well water level fluctuations in the Koyna region, India: the presence of a low order dynamical system in a seismically active environment

    Directory of Open Access Journals (Sweden)

    D. V. Ramana

    2009-05-01

    Full Text Available Water level fluctuations in deep bore wells in the vicinity of seismically active Koyna region in western India provides an opportunity to understand the causative mechanism underlying reservoir-triggered earthquakes. As the crustal porous rocks behave nonlinearly, their characteristics can be obtained by analysing water level fluctuations, which reflect an integrated response of the medium. A Fractal dimension is one such measure of nonlinear characteristics of porous rock as observed in water level data from the Koyna region. It is inferred in our study that a low nonlinear dynamical system with three variables can predict the water level fluctuations in bore wells.

  2. Designing Class Activities to Meet Specific Core Training Competencies: A Developmental Approach

    Science.gov (United States)

    Guth, Lorraine J.; McDonnell, Kelly A.

    2004-01-01

    This article presents a developmental model for designing and utilizing class activities to meet specific Association for Specialists in Group Work (ASGW) core training competencies for group workers. A review of the relevant literature about teaching group work and meeting core training standards is provided. The authors suggest a process by…

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

    Science.gov (United States)

    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.

  4. Modeling the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity values.

    Science.gov (United States)

    Muñoz-Cuevas, Marina; Fernández, Pablo S; George, Susan; Pin, Carmen

    2010-05-01

    The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (a(w)) values. To model the duration of the lag phase, the dependence of the parameter h(0), which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or a(w) were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  6. Modeling the Lag Period and Exponential Growth of Listeria monocytogenes under Conditions of Fluctuating Temperature and Water Activity Values▿

    Science.gov (United States)

    Muñoz-Cuevas, Marina; Fernández, Pablo S.; George, Susan; Pin, Carmen

    2010-01-01

    The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (aw) values. To model the duration of the lag phase, the dependence of the parameter h0, which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or aw were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase. PMID:20208022

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

    DEFF Research Database (Denmark)

    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...... 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...... increased HCV IRES-mediated translation and MAPKAPK3-dependent HCV IRES activity was further increased by core protein. These data suggest that HCV core may modulate MAPKAPK3 to facilitate its own propagation....

  8. Conceptual study of axial offset fluctuations upon stepwise power changes in a thorium–plutonium core to improve load-following conditions

    International Nuclear Information System (INIS)

    Lau, Cheuk Wah; Dykin, Victor; Nylén, Henrik; Björk, Klara Insulander; Sandberg, Urban

    2014-01-01

    Highlights: • Thorium–plutonium mixed oxide to improve nuclear reactors load-following capability. • SIMULATE-3 was the main calculation tool. • The Ringhals-3 PWR unit in Sweden was used as a reference. • Lower xenon poisoning and shorter reactor dead time. - Abstract: The increased share of renewable energy, such as wind and solar power, will increase the demand for load-following power sources, and nuclear reactors could be one option. However, during rapid load-following events, traditional UOX cores could be restricted by the volatile oscillation of the power distribution. Therefore, a conceptual study on stability properties of Th-MOX PWR concerning axial offset power excursion during load-following events are investigated and discussed. The study is performed in SIMULATE-3 for a realistic PWR core (Ringhals-3) at the end of cycle, where the largest amplitude of the axial offset oscillations is expected. It is shown that the Th-MOX core possesses much better stability characteristics and shorter reactor dead time compared with a traditional UOX core, and the main reasons are the lower sensitivity to perturbations in the neutron spectrum, lower xenon poisoning and lower thermal neutron flux

  9. Measurement of magnetic fluctuation induced energy transport

    International Nuclear Information System (INIS)

    Fiksel, G.; Prager, S.C.; Shen, W.; Stoneking, M.

    1993-11-01

    The local electron energy flux produced by magnetic fluctuations has been measured directly in the MST reversed field pinch (over the radial range r/a > 0.75). The flux, produced by electrons traveling parallel to a fluctuating magnetic field, is obtained from correlation between the fluctuations in the parallel heat flux and the radial magnetic field. The fluctuation induced flux is large (100 kW/cm 2 ) in the ''core'' (r/a 2 ) in the edge

  10. Quantum fluctuations

    International Nuclear Information System (INIS)

    Reynaud, S.; Giacobino, S.; Zinn-Justin, J.

    1997-01-01

    This course is dedicated to present in a pedagogical manner the recent developments in peculiar fields concerned by quantum fluctuations: quantum noise in optics, light propagation through dielectric media, sub-Poissonian light generated by lasers and masers, quantum non-demolition measurements, quantum electrodynamics applied to cavities and electrical circuits involving superconducting tunnel junctions. (A.C.)

  11. Regulatory Audit Activities on Nuclear Design of Reactor Cores

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chae-Yong; Lee, Gil Soo; Lee, Jaejun; Kim, Gwan-Young; Bae, Moo-Hun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    Regulatory audit analyses are initiated on the purpose of deep knowledge, solving safety issues, being applied in the review of licensee's results. The current most important safety issue on nuclear design is to verify bias and uncertainty on reactor physics codes to examine the behaviors of high burnup fuel during rod ejection accident (REA) and LOCA, and now regulatory audits are concentrated on solving this issue. KINS develops regulatory audit tools on its own, and accepts ones verified from foreign countries. The independent audit tools are sometimes standardized through participating the international programs. New safety issues on nuclear design, reactor physics tests, advanced reactor core design are steadily raised, which are mainly drawn from the independent examination tools. It is some facing subjects for the regulators to find out the unidentified uncertainties in high burnup fuels and to systematically solve them. The safety margin on nuclear design might be clarified by precisely having independent tools and doing audit calculations by using them. SCALE-PARCS/COREDAX and the coupling with T-H code or fuel performance code would be certainly necessary for achieving these purposes.

  12. Regulatory Audit Activities on Nuclear Design of Reactor Cores

    International Nuclear Information System (INIS)

    Yang, Chae-Yong; Lee, Gil Soo; Lee, Jaejun; Kim, Gwan-Young; Bae, Moo-Hun

    2016-01-01

    Regulatory audit analyses are initiated on the purpose of deep knowledge, solving safety issues, being applied in the review of licensee's results. The current most important safety issue on nuclear design is to verify bias and uncertainty on reactor physics codes to examine the behaviors of high burnup fuel during rod ejection accident (REA) and LOCA, and now regulatory audits are concentrated on solving this issue. KINS develops regulatory audit tools on its own, and accepts ones verified from foreign countries. The independent audit tools are sometimes standardized through participating the international programs. New safety issues on nuclear design, reactor physics tests, advanced reactor core design are steadily raised, which are mainly drawn from the independent examination tools. It is some facing subjects for the regulators to find out the unidentified uncertainties in high burnup fuels and to systematically solve them. The safety margin on nuclear design might be clarified by precisely having independent tools and doing audit calculations by using them. SCALE-PARCS/COREDAX and the coupling with T-H code or fuel performance code would be certainly necessary for achieving these purposes

  13. Critical Thoughts About the Core Entrustable Professional Activities in Undergraduate Medical Education.

    Science.gov (United States)

    Krupat, Edward

    2018-03-01

    The Core Entrustable Professional Activities for Entering Residency (Core EPAs) have taken a strong hold on undergraduate medical education (UME). This Perspective questions their value added and considers the utility of the Core EPAs along two separate dimensions: (1) the ways they change the content and focus of the goals of UME; and (2) the extent to which entrustable professional activity (EPA)-based assessment conforms to basic principles of measurement theory as practiced in the social sciences. Concerning content and focus, the author asks whether the 13 Core EPAs frame UME too narrowly, putting competencies into the background and overlooking certain aspirational, but important and measurable, objectives of UME. The author also discusses the unevenness of EPAs in terms of their breadth and their developmental status as core activities. Regarding measurement and assessment, the author raises concerns that the EPA metric introduces layers of inference that may cause distortions and hinder accuracy and rater agreement. In addition, the use of weak anchors and multidimensional scales is also of concern. The author concludes with a proposal for reframing the Core EPAs and Accreditation Council for Graduate Medical Education competencies into broadly defined sets of behaviors, referred to as "Tasks of Medicine," and calls for the development of a systematic and longitudinal research agenda. The author asserts that "slowing down when you should" applies to medical education as well as patient care, and calls for a reevaluation of the Core EPAs before further commitment to them.

  14. The influence of conformational fluctuations on enzymatic activity: modelling the functional motion of β-secretase

    International Nuclear Information System (INIS)

    Neri, M; Cascella, M; Micheletti, C

    2005-01-01

    Considerable insight into the functional activity of proteins and enzymes can be obtained by studying the low energy conformational distortions that the biopolymer can sustain. We carry out the characterization of these large scale structural changes for a protein of considerable pharmaceutical interest, the human β-secretase. Starting from the crystallographic structure of the protein, we use the recently introduced β-Gaussian model to identify, with negligible computational expenditure, the most significant distortions occurring in thermal equilibrium and the associated timescales. The application of this strategy helps us to gain considerable insight into the putative functional movements and, furthermore, allows us to identify a handful of key regions in the protein which have an important mechanical influence on the enzymatic activity despite being spatially distant from the active site. The results obtained within the Gaussian model are validated through an extensive comparison against an all-atom molecular dynamics simulation

  15. Plasma-activated core-shell gold nanoparticle films with enhanced catalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Llorca, Jordi, E-mail: jordi.llorca@upc.edu; Casanovas, Albert; Dominguez, Montserrat; Casanova, Ignasi [Universitat Politecnica de Catalunya, Institut de Tecniques Energetiques (Spain); Angurell, Inmaculada; Seco, Miquel; Rossell, Oriol [Universitat de Barcelona, Departament de Quimica Inorganica (Spain)

    2008-03-15

    Catalytically active gold nanoparticle films have been prepared from core-shell nanoparticles by plasma-activation and characterized by high-resolution transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Methane can be selectively oxidized into formic acid with an O{sub 2}-H{sub 2} mixture in a catalytic wall reactor functionalized with plasma-activated gold nanoparticle films containing well-defined Au particles of about 3.5 nm in diameter. No catalytic activity was recorded over gold nanoparticle films prepared by thermal decomposition of core-shell nanoparticles due to particle agglomeration.

  16. Plasma-activated core-shell gold nanoparticle films with enhanced catalytic properties

    International Nuclear Information System (INIS)

    Llorca, Jordi; Casanovas, Albert; Dominguez, Montserrat; Casanova, Ignasi; Angurell, Inmaculada; Seco, Miquel; Rossell, Oriol

    2008-01-01

    Catalytically active gold nanoparticle films have been prepared from core-shell nanoparticles by plasma-activation and characterized by high-resolution transmission electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Methane can be selectively oxidized into formic acid with an O 2 -H 2 mixture in a catalytic wall reactor functionalized with plasma-activated gold nanoparticle films containing well-defined Au particles of about 3.5 nm in diameter. No catalytic activity was recorded over gold nanoparticle films prepared by thermal decomposition of core-shell nanoparticles due to particle agglomeration

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Thermal ignition revisited with two-dimensional molecular dynamics: role of fluctuations in activated collisions

    OpenAIRE

    Sirmas, Nick; Radulescu, Matei I.

    2016-01-01

    The problem of thermal ignition in a homogeneous gas is revisited from a molecular dynamics perspective. A two-dimensional model is adopted, which assumes reactive disks of type A and B in a fixed area 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 for the ignition delay are compared with those obtained from the continuum description assumi...

  19. High-intensity, long-duration, continuous AE activity events associated with Alfvénic fluctuations in 2003

    Science.gov (United States)

    Prestes, Alan; Klausner, Virginia; Ojeda-González, Arian

    2017-11-01

    The interaction between a fast-speed and a low-speed stream causes large-amplitude Alfvénic fluctuations; consequently, the intermittency and the brief intervals of southward magnetic field associated with Alfvén waves may cause high levels of AE activity, the so-called high-intensity, long-duration, continuous AE activity (HILDCAA). In this article, the 4 h windowed Pearson cross-correlation (4WPCC) between the solar wind velocity and the interplanetary magnetic field (IMF) components is performed in order to confirm that the less strict HILDCAA (HILDCAAs*) events include a larger number of Alfvén waves than the HILDCAA events, once HILDCAAs disregard part of the phenomenon. Actually, a HILDCAA event is entirely contained within a HILDCAA* event. However, the opposite is not necessarily true. This article provides a new insight, since the increase of Alfvén waves results in an increase of auroral electrojet activity; consequently, it can cause HILDCAAs* events. Another important aspect of this article is that the superposed epoch analysis (SEA) results reaffirm that the HILDCAAs* are associated with high-speed solar streams (HSSs), and also the HILDCAAs* present the same physical characteristics of the traditional HILDCAA events.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    limited to no information is available for their ecophysiology in activated sludge. A combination of MAR-FISH and SIP was applied to identify members of the genera Rhodoferax, Dechloromonas and Sulfuritalea, all within the class Betaproteobacteria, to be core denitrifiers in these systems. Similar...... may explain why many of these core organisms have not attracted attention during the many years of research into the ecology of these systems. The future goal will be to obtain genome sequences for members of these core genera, applying recently developed protocols for the assembly of genomes from...

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Behaviours of several animal species have been linked to lunar periodicity. Evidence for such links in humans is weak; however, recently, shorter sleep duration was reported around full moon in two small samples of adults. As restrictions in sleep duration have been shown to adversely affect...... 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...... compared with days around half moon (both P sleep is responsible for the metabolic alterations observed around full moon. However, we have no understanding of potential mechanisms that may mediate a potential true link between childhood...

  3. Recent eolian activity and paleoclimate fluctuations in the Ferris Lost Soldier Area, South-Central Wyoming

    Science.gov (United States)

    Gaylord, D. R.

    1983-09-01

    The Ferris Dune Fields were examined. Sand dunes are especially valuable in paleoclimate reconstructions because they: (1) bury and preserve datable materials and artifacts; (2) respond to even subtle changes in wind velocity and direction as reflected both in external morphology and internal structures; and (3) remain unconsolidated, making them amenable to easy textural and compositional examination. The valley of Clear Creek in the Ferris Dunes reveals a relatively continuous Holocene section of interbedded dune and interdunal pond deposits. Radiocarbon dates from the interdunal pond strata at Clear Creek, theoretical sand dune migration rates, compositional analysis of periglacial sand wedges, and relative dating of actively migrating parabolic dunes reveals a general sequence of geologic-climatic events that affected the Ferris-Lost Soldier area. The most recent major reactivaton of dunes occurred approximately 290 years ago.

  4. Fluctuation-driven directional flow of energy in biochemical cycle: Electric activation of Na,K ATPase

    Science.gov (United States)

    Yow Tsong, Tian

    1998-03-01

    Na,K ATPase is an ion pump which uses chemical bond energy of ATP to pump Na ion out of, and K ion into living cell thus maintaining ionic and osmotic balances of the cell. Both are uphill transport reactions. Surprisingly we have found that electric energy can also substitute chemical energy to fuel the pump activity. However, in this case only electric fields of certain waveforms, amplitudes, and frequencies are effective. Waveform, amplitude and frequency are three elements of signal. In other words, Na,K ATPase can recognize, process, and harvest energy from an oscillating or a fluctuating electric field to drive an endergonic reaction. The enzyme is a molecular transducer of electric signal. This report will describe electric activation experiment to define electric signal. Electric signal will then mixed with electric noise of broad power spectrum for experiment. Effect of white noise (WN) on the efficiency of Na,K ATPase will be investigated. It will be shown that WN of appropriate power level can improve the pump efficiency when a sub-optimal electric field is used. WN can also carry a sub-threshold signal to cross over the threshold. Stochastic resonance will be discussed in reference to these observations.

  5. Fluctuations in Availability of Arthropods Correlated with Microchiropteran and Avian Predator Activities

    Directory of Open Access Journals (Sweden)

    I.L. Rautenbach

    1988-10-01

    Full Text Available Aerial arthropods were sampled by driving a standard transect along the riparian forest of the Luvuvhu River, South Africa, to assess hourly and seasonal variations in available biomass. Sampling, with an air-plankton net mounted on a vehicle, was conducted hourly over 48-hour periods during the fullest phase of the moon for each of eight months during 1986/87. Seasonal variation in availability of terrestrial arthropods was assessed by means of six pitfall traps set in the riparian forest. On a daily basis, the available biomass of aerial arthropods was found to increase markedly at and during the two hours following sunset, with a slight peak at or in the two hours preceding dawn. Highest monthly availability was found to correspond with the warm summer rainy season, with a marked increase after the first rains. The peak for terrestrial arthropods was found to occur later in the summer than for aerial arthropods. These patterns of arthropod availability correlate well with the daily activity rhythms and seasonal reproduc- tion of microchiropteran bats and their avian predators.

  6. A UAV-based active AirCore system for measurements of greenhouse gases

    Science.gov (United States)

    Andersen, Truls; Scheeren, Bert; Peters, Wouter; Chen, Huilin

    2018-05-01

    We developed and field-tested an unmanned aerial vehicle (UAV)-based active AirCore for atmospheric mole fraction measurements of CO2, CH4, and CO. The system applies an alternative way of using the AirCore technique invented by NOAA. As opposed to the conventional concept of passively sampling air using the atmospheric pressure gradient during descent, the active AirCore collects atmospheric air samples using a pump to pull the air through the tube during flight, which opens up the possibility to spatially sample atmospheric air. The active AirCore system used for this study weighs ˜ 1.1 kg. It consists of a ˜ 50 m long stainless-steel tube, a small stainless-steel tube filled with magnesium perchlorate, a KNF micropump, and a 45 µm orifice working together to form a critical flow of dried atmospheric air through the active AirCore. A cavity ring-down spectrometer (CRDS) was used to analyze the air samples on site not more than 7 min after landing for mole fraction measurements of CO2, CH4, and CO. We flew the active AirCore system on a UAV near the atmospheric measurement station at Lutjewad, located in the northwest of the city of Groningen in the Netherlands. Five consecutive flights took place over a 5 h period on the same morning, from sunrise until noon. We validated the measurements of CO2 and CH4 from the active AirCore against those from the Lutjewad station at 60 m. The results show a good agreement between the measurements from the active AirCore and the atmospheric station (N = 146; R2CO2: 0.97 and R2CH4: 0.94; and mean differences: ΔCO2: 0.18 ppm and ΔCH4: 5.13 ppb). The vertical and horizontal resolution (for CH4) at typical UAV speeds of 1.5 and 2.5 m s-1 were determined to be ±24.7 to 29.3 and ±41.2 to 48.9 m, respectively, depending on the storage time. The collapse of the nocturnal boundary layer and the buildup of the mixed layer were clearly observed with three consecutive vertical profile measurements in the early morning hours. Besides

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  8. Does stress affect the joints? Daily stressors, stress vulnerability, immune and HPA axis activity, and short-term disease and symptom fluctuations in rheumatoid arthritis

    NARCIS (Netherlands)

    Evers, A.W.M.; Verhoeven, E.W.M.; Middendorp, H. van; Sweep, F.C.; Kraaimaat, F.W.; Donders, A.R.T.; Eijsbouts, A.E.; Laarhoven, A.I.M. van; Brouwer, S.J.M. de; Wirken, L.; Radstake, T.R.D.J.; Riel, P.L.C.M. van

    2014-01-01

    OBJECTIVES: Both stressors and stress vulnerability factors together with immune and hypothalamus-pituitary-adrenal (HPA) axis activity components have been considered to contribute to disease fluctuations of chronic inflammatory diseases, such as rheumatoid arthritis (RA). The aim of the present

  9. Physical activity, sleep duration and metabolic health in children fluctuate with the lunar cycle: science behind the myth.

    Science.gov (United States)

    Sjödin, A; Hjorth, M F; Damsgaard, C T; Ritz, C; Astrup, A; Michaelsen, K F

    2015-04-01

    Behaviours of several animal species have been linked to lunar periodicity. Evidence for such links in humans is weak; however, recently, shorter sleep duration was reported around full moon in two small samples of adults. As restrictions in sleep duration have been shown to adversely affect 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 0.03 and 0.05 higher homeostatic model assessment of insulin resistance and 0.6 and 0.8 mmHg higher mean arterial blood pressure compared with days around half moon and new moon, respectively (all P ≤ 0.02). Furthermore, ghrelin was lower and leptin was higher during the period around full moon compared with days around half moon (both P lunar cycle or confounders that may explain this, apparently leading to fluctuation in a number of cardiometabolic risk markers conjointly with lunar phases. © 2015 The Authors. Clinical Obesity published by John Wiley & Sons Ltd on behalf of World Obesity.

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

    Science.gov (United States)

    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.

  11. Mesoporous activated carbon from corn stalk core for lithium ion batteries

    Science.gov (United States)

    Li, Yi; Li, Chun; Qi, Hui; Yu, Kaifeng; Liang, Ce

    2018-04-01

    A novel mesoporous activated carbon (AC) derived from corn stalk core is prepared via a facile and effective method which including the decomposition and carbonization of corn stalk core under an inert gas atmosphere and further activation process with KOH solution. The mesoporous activated carbon (AC) is characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) measurements. These biomass waste derived from activated carbon is proved to be promising anode materials for high specific capacity lithium ion batteries. The activated carbon anode possesses excellent reversible capacity of 504 mAh g-1 after 100 cycles at 0.2C. Compared with the unactivated carbon (UAC), the electrochemical performance of activated carbon is significantly improved due to its mesoporous structure.

  12. Activity of corrosion products in pool type reactors with ascending flow in the core

    International Nuclear Information System (INIS)

    Andrade e Silva, Graciete S. de; Queiroz Bogado Leite, Sergio de

    1995-01-01

    A model for the activity of corrosion products in the water of a pool type reactor with ascending flow is presented. The problem is described by a set of coupled differential equations relating the radioisotope concentrations in the core and pool circuits and taking into account two types of radioactive sources: i) those from radioactive species formed in the fuel cladding, control elements, reflector, etc, and afterwards released to the primary stream by corrosion (named reactor sources) and ii) those formed from non radioactive isotopes entering the primary stream by corrosion of the circuit components and being activated when passing through the core (named circuit sources). (author). 6 refs, 3 figs, 4 tabs

  13. Assessing the mean strength and variations of the time-to-time fluctuations of resting-state brain activity.

    Science.gov (United States)

    Li, Zhengjun; Zang, Yu-Feng; Ding, Jianping; Wang, Ze

    2017-04-01

    The time-to-time fluctuations (TTFs) of resting-state brain activity as captured by resting-state fMRI (rsfMRI) have been repeatedly shown to be informative of functional brain structures and disease-related alterations. TTFs can be characterized by the mean and the range of successive difference. The former can be measured with the mean squared successive difference (MSSD), which is mathematically similar to standard deviation; the latter can be calculated by the variability of the successive difference (VSD). The purpose of this study was to evaluate both the resting state-MSSD and VSD of rsfMRI regarding their test-retest stability, sensitivity to brain state change, as well as their biological meanings. We hypothesized that MSSD and VSD are reliable in resting brain; both measures are sensitive to brain state changes such as eyes-open compared to eyes-closed condition; both are predictive of age. These hypotheses were tested with three rsfMRI datasets and proven true, suggesting both MSSD and VSD as reliable and useful tools for resting-state studies.

  14. Higher frequency network activity flow predicts lower frequency node activity in intrinsic low-frequency BOLD fluctuations.

    Science.gov (United States)

    Bajaj, Sahil; Adhikari, Bhim Mani; Dhamala, Mukesh

    2013-01-01

    The brain remains electrically and metabolically active during resting conditions. The low-frequency oscillations (LFO) of the blood oxygen level-dependent (BOLD) signal of functional magnetic resonance imaging (fMRI) coherent across distributed brain regions are known to exhibit features of this activity. However, these intrinsic oscillations may undergo dynamic changes in time scales of seconds to minutes during resting conditions. Here, using wavelet-transform based time-frequency analysis techniques, we investigated the dynamic nature of default-mode networks from intrinsic BOLD signals recorded from participants maintaining visual fixation during resting conditions. We focused on the default-mode network consisting of the posterior cingulate cortex (PCC), the medial prefrontal cortex (mPFC), left middle temporal cortex (LMTC) and left angular gyrus (LAG). The analysis of the spectral power and causal flow patterns revealed that the intrinsic LFO undergo significant dynamic changes over time. Dividing the frequency interval 0 to 0.25 Hz of LFO into four intervals slow-5 (0.01-0.027 Hz), slow-4 (0.027-0.073 Hz), slow-3 (0.073-0.198 Hz) and slow-2 (0.198-0.25 Hz), we further observed significant positive linear relationships of slow-4 in-out flow of network activity with slow-5 node activity, and slow-3 in-out flow of network activity with slow-4 node activity. The network activity associated with respiratory related frequency (slow-2) was found to have no relationship with the node activity in any of the frequency intervals. We found that the net causal flow towards a node in slow-3 band was correlated with the number of fibers, obtained from diffusion tensor imaging (DTI) data, from the other nodes connecting to that node. These findings imply that so-called resting state is not 'entirely' at rest, the higher frequency network activity flow can predict the lower frequency node activity, and the network activity flow can reflect underlying structural

  15. Does stress affect the joints? Daily stressors, stress vulnerability, immune and HPA axis activity, and short-term disease and symptom fluctuations in rheumatoid arthritis.

    Science.gov (United States)

    Evers, Andrea W M; Verhoeven, Elisabeth W M; van Middendorp, Henriët; Sweep, Fred C G J; Kraaimaat, Floris W; Donders, A Rogier T; Eijsbouts, Agnes E; van Laarhoven, Antoinette I M; de Brouwer, Sabine J M; Wirken, Lieke; Radstake, Timothy R D J; van Riel, Piet L C M

    2014-09-01

    Both stressors and stress vulnerability factors together with immune and hypothalamus-pituitary-adrenal (HPA) axis activity components have been considered to contribute to disease fluctuations of chronic inflammatory diseases, such as rheumatoid arthritis (RA). The aim of the present study was to investigate whether daily stressors and worrying as stress vulnerability factor as well as immune and HPA axis activity markers predict short-term disease activity and symptom fluctuations in patients with RA. In a prospective design, daily stressors, worrying, HPA axis (cortisol) and immune system (interleukin (IL)-1β, IL-6, IL-8, interferon (IFN)-γ, tumour necrosis factor α) markers, clinical and self-reported disease activity (disease activity score in 28 joints, RA disease activity index), and physical symptoms of pain and fatigue were monitored monthly during 6 months in 80 RA patients. Multilevel modelling indicated that daily stressors predicted increased fatigue in the next month and that worrying predicted increased self-reported disease activity, swollen joint count and pain in the next month. In addition, specific cytokines of IL-1β and IFN-γ predicted increased fatigue 1 month later. Overall, relationships remained relatively unchanged after controlling for medication use, disease duration and demographic variables. No evidence was found for immune and HPA axis activity markers as mediators of the stress-disease relationship. Daily stressors and the stress-vulnerability factor worrying predict indicators of the short-term course of RA disease activity and fatigue and pain, while specific cytokines predict short-term fluctuations of fatigue. These stress-related variables and immune markers seem to affect different aspects of disease activity or symptom fluctuations independently in RA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

    Science.gov (United States)

    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.

  17. Neutron activation for logging the distribution of gold in bore-hole cores

    International Nuclear Information System (INIS)

    Rahmanian, H.; Watterson, J.I.W.

    1992-01-01

    A new method for the non-destructive determination of gold in bore-hole cores has been developed using instrumental neutron activation analysis with a 252 Cf source. The procedure obtains the distribution and concentration of gold along the longitudinal axis of the core i.e. a log of the gold concentration. The accuracy of the method is comparable to fire assay at a level of 2 ppm and has a detection limit of 1 ppm under the conditions used. The assay of the gold is carried out by employing a novel variation of the conventional comparator method using gold wires as both standard and flux monitor. A method is described for logging gold in bore-hole cores using neutron activation with a 160 μg 252 Cf neutron source. The method has a limit of detection of about 1 ppm under the described conditions. (author)

  18. Facile Synthesis of Au Nanocube-CdS Core-Shell Nanocomposites with Enhanced Photocatalytic Activity

    Science.gov (United States)

    Liu, Xiao-Li; Liang, Shan; Li, Min; Yu, Xue-Feng; Zhou, Li; Wang, Qu-Qua

    2014-06-01

    Au nanocube-CdS core-shell nanocomposites are prepared by using a one-pot method in aqueous phase with cetyltrimethylammonium bromide as the surfactant. The extinction properties and photocatalytic activity of Au-CdS nanocomposites are investigated. Compared with the pure Au nanocubes, the Au-CdS nanocomposites exhibit enhanced extinction intensity. Compared with CdS nanoparticles, the Au-CdS nanocomposites exhibit improved photocatalytic activity. Furthermore, the photocatalytic efficiency is even better with the increase in the core size of the Au-CdS nanocomposites. Typically, the photocatalytic efficiency of the Au-CdS with 62 nm sized Au nanocubes is about two times higher than that of the pure CdS. It is believed that the Au-CdS nanocomposites may find potential applications in environmental fields, and this synthesis method can be extended to prepare a wide variety of functional composites with Au cores.

  19. Prompt Gamma Activation Analysis of the Nyírlugos obsidian core depot find

    Directory of Open Access Journals (Sweden)

    Zsolt Kasztovszky

    2014-03-01

    Full Text Available The Nyírlugos obsidian core depot find is one of the most important lithic assemblages in the collection of the Hungarian National Museum (HNM. The original set comprised 12 giant obsidian cores, of which 11 are currently on the permanent archaeological exhibition of the HNM. One of the cores is known to be inDebrecen. The first publication attributed the hoard, on the strength of giant (flint blades known from the Early and Middle Copper Age Tiszapolgár and Bodrogkeresztúr cultures, to the Copper Age. In the light of recent finds it is more likely to belong to the Middle Neolithic period. The source area was defined as Tokaj Mts., about100 kmto the NW from Nyírlugos. The size and beauty of the exceptional pieces exclude any invasive analysis. Using Prompt Gamma Activation Analysis (PGAA, we can measure major chemical components and some key trace elements of stone artefacts with adequate accuracy to successfully determine provenance of obsidian. Recent methodological development also facilitated the study of relatively large objects like the Nyírlugos cores. The cores were individually measured by PGAA. The results show that the cores originate from the Carpathian 1 sources, most probably the Viničky variety (C1b. The study of the hoard as a batch is an important contribution to the assessment of prehistoric trade and allows us to reconsider the so-called Carpathian, especially Carpathian 1 (Slovakian sources.

  20. 40 CFR 35.6225 - Activities eligible for funding under Core Program Cooperative Agreements.

    Science.gov (United States)

    2010-07-01

    ... under a Core Program Cooperative Agreement, activities must develop and maintain a recipient's abilities... safety plans, quality assurance project plans, and community relation plans); (2) Provisions for... staff to manage publicly-funded cleanups, oversee responsible party-lead cleanups, and provide clerical...

  1. Standardization of 32P activity determination method in soil-root cores for root distribution studies

    International Nuclear Information System (INIS)

    Sharma, R.B.; Ghildyal, B.P.

    1976-01-01

    The root distribution of wheat variety UP 301 was obtained by determining the 32 P activity in soil-root cores by two methods, viz., ignition and triacid digestion. Root distribution obtained by these two methods was compared with that by standard root core washing procedure. The percent error in root distribution as determined by triacid digestion method was within +- 2.1 to +- 9.0 as against +- 5.5 to +- 21.2 by ignition method. Thus triacid digestion method proved better over the ignition method. (author)

  2. State Public Health Enabling Authorities: Results of a Fundamental Activities Assessment Examining Core and Essential Services

    Science.gov (United States)

    Hoss, Aila; Menon, Akshara; Corso, Liza

    2016-01-01

    Context Public health enabling authorities establish the legal foundation for financing, organizing, and delivering public health services. State laws vary in terms of the content, depth, and breadth of these fundamental public health activities. Given this variance, the Institute of Medicine has identified state public health laws as an area that requires further examination. To respond to this call for further examination, the Centers for Disease Control and Prevention’s Public Health Law Program conducted a fundamental activities legal assessment on state public health laws. Objective The goal of the legal assessment was to examine state laws referencing frameworks representing public health department fundamental activities (ie, core and essential services) in an effort to identify, catalog, and describe enabling authorities of state governmental public health systems. Design In 2013, Public Health Law Program staff compiled a list of state statutes and regulations referencing different commonly-recognized public health frameworks of fundamental activities. The legal assessment included state fundamental activities laws available on WestlawNext as of July 2013. The results related to the 10 essential public health services and the 3 core public health functions were confirmed and updated in June 2016. Results Eighteen states reference commonly-recognized frameworks of fundamental activities in their laws. Thirteen states have listed the 10 essential public health services in their laws. Eight of these states have also referenced the 3 core public health functions in their laws. Five states reference only the core public health functions. Conclusions Several states reference fundamental activities in their state laws, particularly through use of the essential services framework. Further work is needed to capture the public health laws and practices of states that may be performing fundamental activities but without reference to a common framework. PMID

  3. State Public Health Enabling Authorities: Results of a Fundamental Activities Assessment Examining Core and Essential Services.

    Science.gov (United States)

    Hoss, Aila; Menon, Akshara; Corso, Liza

    2016-01-01

    Public health enabling authorities establish the legal foundation for financing, organizing, and delivering public health services. State laws vary in terms of the content, depth, and breadth of these fundamental public health activities. Given this variance, the Institute of Medicine has identified state public health laws as an area that requires further examination. To respond to this call for further examination, the Centers for Disease Control and Prevention's Public Health Law Program conducted a fundamental activities legal assessment on state public health laws. The goal of the legal assessment was to examine state laws referencing frameworks representing public health department fundamental activities (ie, core and essential services) in an effort to identify, catalog, and describe enabling authorities of state governmental public health systems. In 2013, Public Health Law Program staff compiled a list of state statutes and regulations referencing different commonly-recognized public health frameworks of fundamental activities. The legal assessment included state fundamental activities laws available on WestlawNext as of July 2013. The results related to the 10 essential public health services and the 3 core public health functions were confirmed and updated in June 2016. Eighteen states reference commonly-recognized frameworks of fundamental activities in their laws. Thirteen states have listed the 10 essential public health services in their laws. Eight of these states have also referenced the 3 core public health functions in their laws. Five states reference only the core public health functions. Several states reference fundamental activities in their state laws, particularly through use of the essential services framework. Further work is needed to capture the public health laws and practices of states that may be performing fundamental activities but without reference to a common framework.

  4. CORE MUSCLE ACTIVITY DURING THE CLEAN AND JERK LIFT WITH BARBELL VERSUS SANDBAGS AND WATER BAGS.

    Science.gov (United States)

    Calatayud, Joaquin; Colado, Juan C; Martin, Fernando; Casaña, José; Jakobsen, Markus D; Andersen, Lars L

    2015-11-01

    While the traditional clean and jerk maneuver implies simultaneous participation of a large number of muscle groups, the use of this exercise with some variations to enhance core muscle activity remains uninvestigated. The purpose of this study was to compare the muscle activity during clean and jerk lift when performed with a barbell, sandbag and a water bag at same absolute load. Descriptive, repeated-measures study. Twenty-one young fit male university students (age: 25 ± 2.66 years; height: 180.71 ± 5.42 cm; body mass: 80.32 ± 9.8 kg; body fat percentage: 12.41 ± 3.56 %) participated. Surface electromyographic (EMG) signals were recorded from the anterior deltoid (AD), external oblique (OBLIQ), lumbar erector spinae (LUMB), and gluteus medius (GM) and were expressed as a percentage of the maximum voluntary isometric contraction (MVIC). There were no significantly significant differences for AD muscle activity between conditions, whereas muscle activation values for OBLIQ (60%MVIC), GM (29%MVIC) and LUMB (85%MVIC) were significantly higher during the water bag power clean and jerk maneuver when compared with the other conditions. The clean and jerk is an exercise that may be used to enhance core muscle activity. Performing the maneuver with water bags resulted in higher core muscle activity compared with sandbag and standard barbell versions. 3.

  5. Fluctuation analysis

    International Nuclear Information System (INIS)

    Clarke, J.

    1980-01-01

    This paper briefly reviews sources of noise in Josephson junctions, and the limits they impose on the sensitivity of dc and rf SQUIDS. The results are strictly valid only for a resistively shunted junction (RSJ) with zero capacitance, but should be applicable to point contact junctions and microbridges in so far as these devices can be approximated by the RSJ model. Fluctuations arising from Nyquist noise in the resistive shunt of a single junction are discussed in the limit eI/sub o/R/k/sub B/T << 1 in which a classical treatment is appropriate, and then extend the treatment to the limit eI/sub o/R/k/sub B/T greater than or equal to 1 in which quantum effects become important. The Nyquist limit theory is used to calculate the noise in a dc SQUID, and the results are compared with a number of practical devices. The quantum limit is briefly considered. Results for the predicted sensitivity of rf SQUIDS are presented, and also compared with a number of practical devices. Finally, the importance of l/f noise (f is the frequency) in limiting the low frequency performance of SQUIDS is discussed

  6. A UAV-based active AirCore system for measurements of greenhouse gases

    Directory of Open Access Journals (Sweden)

    T. Andersen

    2018-05-01

    Full Text Available We developed and field-tested an unmanned aerial vehicle (UAV-based active AirCore for atmospheric mole fraction measurements of CO2, CH4, and CO. The system applies an alternative way of using the AirCore technique invented by NOAA. As opposed to the conventional concept of passively sampling air using the atmospheric pressure gradient during descent, the active AirCore collects atmospheric air samples using a pump to pull the air through the tube during flight, which opens up the possibility to spatially sample atmospheric air. The active AirCore system used for this study weighs ∼ 1.1 kg. It consists of a ∼ 50 m long stainless-steel tube, a small stainless-steel tube filled with magnesium perchlorate, a KNF micropump, and a 45 µm orifice working together to form a critical flow of dried atmospheric air through the active AirCore. A cavity ring-down spectrometer (CRDS was used to analyze the air samples on site not more than 7 min after landing for mole fraction measurements of CO2, CH4, and CO. We flew the active AirCore system on a UAV near the atmospheric measurement station at Lutjewad, located in the northwest of the city of Groningen in the Netherlands. Five consecutive flights took place over a 5 h period on the same morning, from sunrise until noon. We validated the measurements of CO2 and CH4 from the active AirCore against those from the Lutjewad station at 60 m. The results show a good agreement between the measurements from the active AirCore and the atmospheric station (N  =  146; R2CO2: 0.97 and R2CH4: 0.94; and mean differences: ΔCO2: 0.18 ppm and ΔCH4: 5.13 ppb. The vertical and horizontal resolution (for CH4 at typical UAV speeds of 1.5 and 2.5 m s−1 were determined to be ±24.7 to 29.3 and ±41.2 to 48.9 m, respectively, depending on the storage time. The collapse of the nocturnal boundary layer and the buildup of the mixed layer were clearly observed with three consecutive vertical

  7. Study of density fluctuations during MHD activity, soft landing discharges and major disruptions in TEXTOR using CO2 laser collective scattering

    International Nuclear Information System (INIS)

    Boileau, A.; Van Andel, H.W.H.; Hellermann, M. von; Rogister, A.

    1987-01-01

    A modulation of microturbulence is observed in TEXTOR during low mode number MHD activity using CO 2 laser collective scattering. This is accomplished by a strong enhancement of density fluctuations near ka s approx. = 3 at the end of soft landing discharges and a displacement of the frequency spectrum towards lower frequencies. The increase is most significant for rapid rampdown of the plasma current accompanied by strong MHD activity but also occurs when the latter is not detected. The evolution of microturbulence is also studied during major plasma disruptions. It was found that disruptions without MHD precursor oscillations are characterized by a rapid increase in the density fluctuations starting approx. 100 ms before plasma disruption. (author)

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

    International Nuclear Information System (INIS)

    Baraliya, Jagdish D.; Joshi, Hiren H.

    2014-01-01

    We report the results of biological study on core-shell structured MFe 2 O 4 (where M = Co, Mn, Ni) nanoparticles and influence of silica- DEG dual coating on their antimicrobial activity. Spherical MFe 2 O 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

  9. ISOTROPIC HEATING OF GALAXY CLUSTER CORES VIA RAPIDLY REORIENTING ACTIVE GALACTIC NUCLEUS JETS

    International Nuclear Information System (INIS)

    Babul, Arif; Sharma, Prateek; Reynolds, Christopher S.

    2013-01-01

    Active galactic nucleus (AGN) jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic fashion and narrow bipolar jets with P jet = 10 44–45 erg s –1 , typical of radio AGNs at cluster centers, are inefficient in heating the gas in the transverse direction to the jets. We argue that due to existent conditions in cluster cores, the supermassive black holes (SMBHs) will, in addition to accreting gas via radiatively inefficient flows, experience short stochastic episodes of enhanced accretion via thin disks. In general, the orientation of these accretion disks will be misaligned with the spin axis of the black holes (BHs) and the ensuing torques will cause the BH's spin axis (and therefore the jet axis) to slew and rapidly change direction. This model not only explains recent observations showing successive generations of jet-lobes-bubbles in individual cool-core clusters that are offset from each other in the angular direction with respect to the cluster center, but also shows that AGN jets can heat the cluster core nearly isotropically on the gas cooling timescale. Our model does require that the SMBHs at the centers of cool-core clusters be spinning relatively slowly. Torques from individual misaligned disks are ineffective at tilting rapidly spinning BHs by more than a few degrees. Additionally, since SMBHs that host thin accretion disks will manifest as quasars, we predict that roughly 1-2 rich clusters within z < 0.5 should have quasars at their centers.

  10. Effect of high temperature filtration on out-core corrosion product activity

    International Nuclear Information System (INIS)

    Horvath, G.L.; Bogancs, J.

    1983-01-01

    Investigation of the effect of high temperature filtration on corrosion product transport and out-core corrosion product activity has been carried out for VVER-440 plants. In the physico-chemical model applied particulate and dissolved corrosion products were taken into account. We supposed 100% effectivity for the particulate filter. It was found that about 0,5% 160 t/h/ of the main flow would result in an approx.50% reduction of the out-core corrosion product activity. Investigation of the details of the physico-chemical model in Nuclear Power Plant Paks showed a particle deposition rate measured during power transients fairly agreeing with other measurements and data used in the calculations. (author)

  11. Investigation of magnetic active core sizes and hydrodynamic diameters of a magnetically fractionated ferrofluid

    International Nuclear Information System (INIS)

    Büttner, Markus; Weber, Peter; Schmidl, Frank; Seidel, Paul; Röder, Michael; Schnabelrauch, Matthias; Wagner, Kerstin; Görnert, Peter; Glöckl, Gunnar; Weitschies, Werner

    2011-01-01

    In this work we address the question which relates between the size of the magnetically active core of magnetic nanoparticles (MNPs) and the size of the overall particle in the solution (the so-called hydrodynamic diameter d hyd ) exists. For this purpose we use two methods of examination that can deliver conclusions about the properties of MNP which are not accessible with normal microscopy. On the one hand, we use temperature dependent magnetorelaxation (TMRX) method, which enables direct access to the energy barrier distribution and by using additional hysteresis loop measurements can provide details about the size of the magnetically active cores. On the other hand, to determine the size of the overall particle in the solution, we use the magnetooptical relaxation of ferrofluids (MORFF) method, where the stimulation is done magnetically while the reading of the relaxation signal, however, is done optically. As a basis for the examinations in this work we use a ferrofluid that was developed for medicinal purposes and which has been fractioned magnetically to obtain differently sized fractions of MNPs. The two values obtained through these methods for each fraction shows the success in fractioning the original solution. Therefore, one can conclude a direct correlation between the size of the magnetically active core and the size of the complete particle in the solution from the experimental results. To calculate the size of the magnetically active core we found a temperature dependent anisotropy constant which was taken into account for the calculations. Furthermore, we found relaxation signals at 18 K for all fractions in these TMRX measurements, which have their origin in other magnetic effects than the Néel relaxation.

  12. A novel technique to measure intensity fluctuations in EUV images and to detect coronal sound waves nearby active regions

    Science.gov (United States)

    Stenborg, G.; Marsch, E.; Vourlidas, A.; Howard, R.; Baldwin, K.

    2011-02-01

    Context. In the past years, evidence for the existence of outward-moving (Doppler blue-shifted) plasma and slow-mode magneto-acoustic propagating waves in various magnetic field structures (loops in particular) in the solar corona has been found in ultraviolet images and spectra. Yet their origin and possible connection to and importance for the mass and energy supply to the corona and solar wind is still unclear. There has been increasing interest in this problem thanks to the high-resolution observations available from the extreme ultraviolet (EUV) imagers on the Solar TErrestrial RElationships Observatory (STEREO) and the EUV spectrometer on the Hinode mission. Aims: Flows and waves exist in the corona, and their signatures appear in EUV imaging observations but are extremely difficult to analyse quantitatively because of their weak intensity. Hence, such information is currently available mostly from spectroscopic observations that are restricted in their spatial and temporal coverage. To understand the nature and origin of these fluctuations, imaging observations are essential. Here, we present measurements of the speed of intensity fluctuations observed along apparently open field lines with the Extreme UltraViolet Imagers (EUVI) onboard the STEREO mission. One aim of our paper is to demonstrate that we can make reliable kinematic measurements from these EUV images, thereby complementing and extending the spectroscopic measurements and opening up the full corona for such an analysis. Another aim is to examine the assumptions that lead to flow versus wave interpretation for these fluctuations. Methods: We have developed a novel image-processing method by fusing well established techniques for the kinematic analysis of coronal mass ejections (CME) with standard wavelet analysis. The power of our method lies with its ability to recover weak intensity fluctuations along individual magnetic structures at any orientation , anywhere within the full solar disk , and

  13. Effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 expression in juvenile chinese shrimp, Fenneropenaeus chinensis

    Science.gov (United States)

    Ding, Sen; Wang, Fang; Sun, Hao; Guo, Biao; Dong, Shuanglin

    2009-03-01

    Experiments were conducted to examine the effects of salinity fluctuation frequency on the osmolarity, Na+-K+-ATPase activity and HSP70 of Chinese shrimp Fenneropenaeus chinensis with initial wet body weight of 1.460 g ± 0.091 g. The salinity in the control group (D0) was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8 d, respectively, decreased abruptly to salinity 24, lasted for another 2 d, and then was raised to its initial value 28. This was a complete salinity fluctuation cycle that afterwards repeated itself. After 32 days, the osmolarity in treatments D2, D4, D6 and D8 was significantly lower than that in treatment D0 ( P<0.05). There were significant differences in both muscle and eyestalks HSP70 expression among groups. The HSP70 expressions in muscle and eyestalks in group D4 were 61.4% and 57.0% higher, respectively, than that in the control group D0 ( P<0.05). There were, however, no significant differences in gill or hepatopancreas Na+-K+-ATPase activity between the treatments and the control.

  14. Fluctuations in quantum chaos

    International Nuclear Information System (INIS)

    Casati, G.; Chirikov, B.V.

    1996-01-01

    Various fluctuations in quantum systems with discrete spectrum are discussed, including recent unpublished results. Open questions and unexplained peculiarities of quantum fluctuations are formulated [ru

  15. Enhancement of curcumin water dispersibility and antioxidant activity using core-shell protein-polysaccharide nanoparticles.

    Science.gov (United States)

    Huang, Xiaoxia; Huang, Xulin; Gong, Yushi; Xiao, Hang; McClements, David Julian; Hu, Kun

    2016-09-01

    Curcumin has strong antioxidant activity, but poor water-solubility and chemical stability, which limits its utilization as a nutraceutical in many applications. Previously, we developed a core-shell (zein-pectin) nanoparticle delivery system with high curcumin loading efficiency, high particle yield, and good water dispersibility. However, this system was unstable to aggregation around neutral pH and moderate ionic strengths due to weakening of electrostatic repulsion between nanoparticles. In the current study, we used a combination of alginate (high charge density) and pectin (low charge density) to form the shell around zein nanoparticles. Replacement of 30% of pectin with alginate greatly improved aggregation stability at pH 5 to 7 and at high ionic strengths (2000mM NaCl). Curcumin encapsulated within these core-shell nanoparticles exhibited higher antioxidant and radical scavenging activities than curcumin solubilized in ethanol solutions as determined by Fe (III) reducing power, 1, 1-Diphenyl-2-picrylhydrazyl free radical (DPPH·), and 2, 2'-azinobis-(3-ethylbenzothiazoline)-6-sulfonic acid radical cation (ABTS· + ) scavenging analysis. These core-shell nanoparticles may be useful for incorporating chemically unstable hydrophobic nutraceuticals such as curcumin into functional foods, dietary supplements, and pharmaceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. Alterations in task-induced activity and resting-state fluctuations in visual and DMN areas revealed in long-term meditators.

    Science.gov (United States)

    Berkovich-Ohana, Aviva; Harel, Michal; Hahamy, Avital; Arieli, Amos; Malach, Rafael

    2016-07-15

    Recently we proposed that the information contained in spontaneously emerging (resting-state) fluctuations may reflect individually unique neuro-cognitive traits. One prediction of this conjecture, termed the "spontaneous trait reactivation" (STR) hypothesis, is that resting-state activity patterns could be diagnostic of unique personalities, talents and life-styles of individuals. Long-term meditators could provide a unique experimental group to test this hypothesis. Using fMRI we found that, during resting-state, the amplitude of spontaneous fluctuations in long-term mindfulness meditation (MM) practitioners was enhanced in the visual cortex and significantly reduced in the DMN compared to naïve controls. Importantly, during a visual recognition memory task, the MM group showed heightened visual cortex responsivity, concomitant with weaker negative responses in Default Mode Network (DMN) areas. This effect was also reflected in the behavioral performance, where MM practitioners performed significantly faster than the control group. Thus, our results uncover opposite changes in the visual and default mode systems in long-term meditators which are revealed during both rest and task. The results support the STR hypothesis and extend it to the domain of local changes in the magnitude of the spontaneous fluctuations. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Summary on the activity of AERs Working Group on core monitoring (flux reconstruction, in-core measurements)

    International Nuclear Information System (INIS)

    Nemes, I.

    2010-01-01

    Working Group C had a joint meeting with Group G in Balatonfuered, Hungary, 31 May-1 June, 2010. At the joint meeting 21 people from 10 AER member organisations of 4 countries - such as Russia, Czech Republic, Slovakia and Hungary - participated. In the 2 days of the program 15 papers were presented, 10 from these connected to the topic of working group C. The title of papers and the list of participants are attached. At the meeting the following topics were discussed:1-Gd fuel introduction and experiences;2-Reactor physical measurement and evaluation problems; 3-Code development and testing;4-In-core surveillance system developments. (Author)

  20. Program Director Perceptions of Proficiency in the Core Entrustable Professional Activities.

    Science.gov (United States)

    Pearlman, R Ellen; Pawelczak, Melissa; Yacht, Andrew C; Akbar, Salaahuddin; Farina, Gino A

    2017-10-01

    The Association of American Medical Colleges describes 13 core entrustable professional activities (EPAs) that every graduating medical student should be expected to perform proficiently on day 1 of residency, regardless of chosen specialty. Studies have shown wide variability in program director (PD) confidence in interns' abilities to perform these core EPAs. Little is known regarding comparison of United States Medical Licensing Examination (USMLE) scores with proficiency in EPAs. We determined if PDs from a large health system felt confident in their postgraduate year 1 residents' abilities to perform the 13 core EPAs, and compared perceived EPA proficiency with USMLE Step 1 and Step 2 scores. The PDs were asked to rate their residents' proficiency in each EPA and to provide residents' USMLE scores. Timing coincided with the reporting period for resident milestones. Surveys were completed on 204 of 328 residents (62%). PDs reported that 69% of residents (140 of 204) were prepared for EPA 4 (orders/prescriptions), 61% (117 of 192) for EPA 7 (form clinical questions), 68% (135 of 198) for EPA 8 (handovers), 63% (116 of 185) for EPA 11 (consent), and 38% (49 of 129) for EPA 13 (patient safety). EPA ratings and USMLE 1 and 2 were negatively correlated ( r (101) = -0.23, P  = .031). PDs felt that a significant percentage of residents were not adequately prepared in order writing, forming clinical questions, handoffs, informed consent, and promoting a culture of patient safety. We found no positive association between USMLE scores and EPA ratings.

  1. The commitment of Indra with the innovation as core of its activities

    International Nuclear Information System (INIS)

    Martin de castro, G.; Lopez Saez, P.; Murcia Rivera, C.

    2007-01-01

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    Magnetic Fe 3 O 4 @CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe 3 O 4 @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 Fe 3 O 4 core and a CuO shell. The Fe 3 O 4 @CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe 3 O 4 -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. - Graphical abstract: Fe 3 O 4 @CuO core-shell release of copper ions. These Cu 2+ ions were responsible for the exhibited antibacterial activity. - Highlights: • The Fe 3 O 4 @CuO core-shell was prepared by MOF method. • This is the first study of antibacterial activity of core-shell consist of CuO and Fe 3 O 4 . • The core-shell can be reused effectively. • Core-shell was separated from the reaction solution by external magnetic field.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Tao; Yu, Shanwen; Fang, Xiaoxin; Huang, Honghong; Li, Lun [School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan (China); Wang, Xiuyuan [College of Plant Science and Technology, Huazhong Agricultural University, Wuhan (China); Wang, Huihu, E-mail: wanghuihu@mail.hbut.edu.cn [School of Materials and Chemical Engineering, Hubei University of Technology, Wuhan (China); Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan (China)

    2016-12-15

    Highlights: • C@ZnO nanostructures were synthesized by a facile hydrothermal carbonization method. • Glucose content has a great influence on the microstructure of C@ZnO nanostructures. • An ultrathin amorphous carbon layer enhances the adsorption capacity of C@ZnO. • C@ZnO nanostructures exhibit the improved photocatalytic activity and stability. - Abstract: 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.

  6. The relationship between solar activity and the H and K line cores in integrated sunlight

    International Nuclear Information System (INIS)

    Jebsen, D.E.; Mitchell, W.E. Jr.

    1978-01-01

    In this paper the authors present and analyze new data on the cores of the H and K lines of ionized calcium in the spectrum of integrated sunlight. The intensities of the components Hsub(2γ), H 3 , Hsub(2r), Ksub(2γ), K 3 , and Ksub(2r) in the line cores were measured in terms of the continuum intensity at 4000 A during a solar rotation in September 1969. Other data on these components, obtained at or close to the time of solar minimum (September 1964) and solar maximum (September 1968), were also included. The intensities of these features are compared with two indices of solar activity: the Ca II plage index and the 2800 MHZ signal. The average correlation coefficients between the intensities of the measured features and those indices were 0.69 and 0.64, respectively. The results are consistent with those of Bumba and Ruzickova-Topolova (1967) for a solar rotation period in 1965. The method and results should provide a detailed quantitative basis for the study of the activity cycles and rotation periods of solar-type stars. (Auth.)

  7. Shielding and activation calculations around the reactor core for the MYRRHA ADS design

    Science.gov (United States)

    Ferrari, Anna; Mueller, Stefan; Konheiser, J.; Castelliti, D.; Sarotto, M.; Stankovskiy, A.

    2017-09-01

    In the frame of the FP7 European project MAXSIMA, an extensive simulation study has been done to assess the main shielding problems in view of the construction of the MYRRHA accelerator-driven system at SCK·CEN in Mol (Belgium). An innovative method based on the combined use of the two state-of-the-art Monte Carlo codes MCNPX and FLUKA has been used, with the goal to characterize complex, realistic neutron fields around the core barrel, to be used as source terms in detailed analyses of the radiation fields due to the system in operation, and of the coupled residual radiation. The main results of the shielding analysis are presented, as well as the construction of an activation database of all the key structural materials. The results evidenced a powerful way to analyse the shielding and activation problems, with direct and clear implications on the design solutions.

  8. Addendum to ''Density fluctuations in liquid rubidium''

    International Nuclear Information System (INIS)

    Haan, S.W.; Mountain, R.D.; Hsu, C.S.; Rahman, A.

    1980-01-01

    We performed molecular-dynamics simulations of liquid rubidium and the Lennard-Jones fluid at several densities and temperatures, and of a system whose pair potential is the repulsive core of the rubidium potential. In all cases, propagating density fluctuations occurred in the rubidiumlike systems at much shorter wavelengths than in the Lennard-Jones system. This indicates that the repulsive part of the pair potential is the dominant factor in determining the relaxation of short-wavelength density fluctuations

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Preservice Secondary Teachers' Conceptions from a Mathematical Modeling Activity and Connections to the Common Core State Standards

    Science.gov (United States)

    Stohlmann, Micah; Maiorca, Cathrine; Olson, Travis A.

    2015-01-01

    Mathematical modeling is an essential integrated piece of the Common Core State Standards. However, researchers have shown that mathematical modeling activities can be difficult for teachers to implement. Teachers are more likely to implement mathematical modeling activities if they have their own successful experiences with such activities. This…

  11. ACTIVE GALACTIC NUCLEUS FEEDBACK AND ENTROPY INJECTION IN GALAXY CLUSTER CORES

    International Nuclear Information System (INIS)

    Chaudhuri, Anya; Majumdar, Subhabrata; Nath, Biman B.

    2013-01-01

    We make the first estimate of non-gravitational energy profiles in galaxy cluster cores (and beyond) based on observational data. Comparing the observed entropy profiles within r 500 , from the Representative XMM-Newton Cluster Structure Survey to simulated base entropy profiles without feedback from both adaptive mesh refinement (AMR) and smoothed particle hydrodynamic (SPH) non-radiative simulations, we estimate the amount of additional non-gravitational energy, E ICM , contained in the intracluster medium (ICM), as well as the total energy feedback, E Feedback , from active galactic nuclei (AGNs; the central AGNs in most cases) into the clusters. The total feedback energy scales with the mean spectroscopic temperature as E Feedback ∝T sp 2.52±0.08 and E Feedback ∝T sp 2.17±0.11 for the SPH and AMR baseline profiles. The mean non-gravitational energy per particle within r 500 remaining in the ICM after energy lost during cooling is ε ICM = 2.8 ± 0.8 keV for the SPH theoretical relation and ε ICM = 1.7 ± 0.9 keV for the AMR theoretical relation. We use the NRAO/VLA Sky Survey source catalog to determine the radio luminosity, L R , at 1.4 GHz of the central source(s) of our sample. For T sp > 3 keV, the E Feedback correlates with L R , although with different normalization for cool-core and non-cool-core clusters. We show that AGNs could provide a significant portion of the feedback

  12. Rapid fluctuations in extracellular brain glucose levels induced by natural arousing stimuli and intravenous cocaine: fueling the brain during neural activation

    Science.gov (United States)

    Lenoir, Magalie

    2012-01-01

    Glucose, a primary energetic substrate for neural activity, is continuously influenced by two opposing forces that tend to either decrease its extracellular levels due to enhanced utilization in neural cells or increase its levels due to entry from peripheral circulation via enhanced cerebral blood flow. How this balance is maintained under physiological conditions and changed during neural activation remains unclear. To clarify this issue, enzyme-based glucose sensors coupled with high-speed amperometry were used in freely moving rats to evaluate fluctuations in extracellular glucose levels induced by brief audio stimulus, tail pinch (TP), social interaction with another rat (SI), and intravenous cocaine (1 mg/kg). Measurements were performed in nucleus accumbens (NAcc) and substantia nigra pars reticulata (SNr), which drastically differ in neuronal activity. In NAcc, where most cells are powerfully excited after salient stimulation, glucose levels rapidly (latency 2–6 s) increased (30–70 μM or 6–14% over baseline) by all stimuli; the increase differed in magnitude and duration for each stimulus. In SNr, where most cells are transiently inhibited by salient stimuli, TP, SI, and cocaine induced a biphasic glucose response, with the initial decrease (−20–40 μM or 5–10% below baseline) followed by a reboundlike increase. The critical role of neuronal activity in mediating the initial glucose response was confirmed by monitoring glucose currents after local microinjections of glutamate (GLU) or procaine (PRO). While intra-NAcc injection of GLU transiently increased glucose levels in this structure, intra-SNr PRO injection resulted in rapid, transient decreases in SNr glucose. Therefore, extracellular glucose levels in the brain change very rapidly after physiological and pharmacological stimulation, the response is structure specific, and the pattern of neuronal activity appears to be a critical factor determining direction and magnitude of physiological

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

    Directory of Open Access Journals (Sweden)

    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.

  14. OUTFLOWS AND DARK BANDS AT ARCADE-LIKE ACTIVE REGION CORE BOUNDARIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott, J. T.; Martens, P. C. H.; Tarr, L. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2013-03-10

    Observations from the EUV Imaging Spectrometer (EIS) on board Hinode have revealed outflows and non-thermal line broadening in low intensity regions at the edges of active regions (ARs). We use data from Hinode's EIS, Solar Dynamic Observatory's Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager, and the Transition Region and Coronal Explorer instrument to investigate the boundaries of arcade-like AR cores for NOAA ARs 11112, 10978, and 9077. A narrow, low intensity region that is observed at the core's periphery as a dark band shows outflows and increased spectral line broadening. This dark band is found to exist for days and appears between the bright coronal loop structures of different coronal topologies. We find a case where the dark band region is formed between the magnetic field from emerging flux and the field of the pre-existing flux. A magnetic field extrapolation indicates that this dark band is coincident with the spine lines or magnetic separatrices in the extrapolated field. This occurs over unipolar regions where the brightened coronal field is separated in connectivity and topology. This separation does not appear to be infinitesimal and an initial estimate of the minimum distance of separation is found to be Almost-Equal-To 1.5-3.5 Mm.

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

    KAUST Repository

    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.

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

    KAUST Repository

    Ferreira, Ari J S; Siam, Rania; Setubal, Joã o C; Moustafa, Ahmed; Sayed, Ahmed; Chambergo, Felipe S; Dawe, Adam S; Ghazy, Mohamed A; Sharaf, Hazem; Ouf, Amged; Alam, Intikhab; Abdel-Haleem, Alyaa M; Lehvä slaiho, Heikki; Ramadan, Eman; Antunes, André ; Stingl, Ulrich; Archer, John A.C.; Jankovic, Boris R; Sogin, Mitchell; Bajic, Vladimir B.; El-Dorry, Hamza

    2014-01-01

    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.

  17. Water-filled training tubes increase core muscle activation and somatosensory control of balance during squat.

    Science.gov (United States)

    Ditroilo, Massimiliano; O'Sullivan, Rory; Harnan, Brian; Crossey, Aislinn; Gillmor, Beth; Dardis, William; Grainger, Adam

    2018-09-01

    This study examined trunk muscle activation, balance and proprioception while squatting with a water-filled training tube (WT) and a traditional barbell (BB), with either closed (CE) or open eyes (OE). Eighteen male elite Gaelic footballers performed an isometric squat under the following conditions: BB-OE, BB-CE, WT-OE and WT-CE. The activity of rectus abdominis (RA), external oblique (EO) and multifidus (MF) was measured using electromyography, along with sway of the centre of pressure (CoP) using a force platform. Only the EO and the MF muscles exhibited an increased activity with WT (p velocity and range of the CoP increased significantly with WT (p velocity of the CoP was marginally reduced (d = 0.29). WT elicited a greater level core muscle activation and created a greater challenge to postural stability when compared to a BB. It appears that WT does not benefit from vision but emphasises the somatosensory control of balance. The use of WT may be beneficial in those sports requiring development of somatosensory/proprioceptive contribution to balance control.

  18. An Objective Fluctuation Score for Parkinson's Disease

    Science.gov (United States)

    Horne, Malcolm K.; McGregor, Sarah; Bergquist, Filip

    2015-01-01

    Introduction 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. Methods 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. Results 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. Conclusion 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. PMID:25928634

  19. Distribution of 35 Elements in Peat Cores from Ombrotrophic Bogs Studied by Epithermal Neutron Activation Analysis

    CERN Document Server

    Frontasyeva, M V

    2004-01-01

    In ombrotrophic bogs the surface peat layer is supplied with chemical substances only from the atmosphere. Peat cores from these bogs therefore can be used to study temporal trends in atmospheric deposition of pollutants. In this work epithermal neutron activation analysis was applied for the first time to study the distribution of 35 elements in peat profiles from ombrotrophic bogs. The selected examples were from Finnmark county in northern Norway: one pristine site far from any local pollution source, and another strongly affected by long-term operation of Russian copper-nickel smelters located close to the border. The elements are classified with respect to their behavior in the uppermost 40 cm of the peat, and similarities and differences between the two profiles are discussed. As compared with other more commonly used analytical techniques based on acid decomposition of the sample ENAA has the advantage of providing the total concentrations of the elements.

  20. Thermally activated post-glitch response of the neutron star inner crust and core. I. Theory

    Energy Technology Data Exchange (ETDEWEB)

    Link, Bennett, E-mail: link@physics.montana.edu [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2014-07-10

    Pinning of superfluid vortices is predicted to prevail throughout much of a neutron star. Based on the idea of Alpar et al., I develop a description of the coupling between the solid and liquid components of a neutron star through thermally activated vortex slippage, and calculate the response to a spin glitch. The treatment begins with a derivation of the vortex velocity from the vorticity equations of motion. The activation energy for vortex slippage is obtained from a detailed study of the mechanics and energetics of vortex motion. I show that the 'linear creep' regime introduced by Alpar et al. and invoked in fits to post-glitch response is not realized for physically reasonable parameters, a conclusion that strongly constrains the physics of a post-glitch response through thermal activation. Moreover, a regime of 'superweak pinning', crucial to the theory of Alpar et al. and its extensions, is probably precluded by thermal fluctuations. The theory given here has a robust conclusion that can be tested by observations: for a glitch in the spin rate of magnitude Δν, pinning introduces a delay in the post-glitch response time. The delay time is t{sub d} = 7(t{sub sd}/10{sup 4} yr)((Δν/ν)/10{sup –6}) d, where t{sub sd} is the spin-down age; t{sub d} is typically weeks for the Vela pulsar and months in older pulsars, and is independent of the details of vortex pinning. Post-glitch response through thermal activation cannot occur more quickly than this timescale. Quicker components of post-glitch response, as have been observed in some pulsars, notably, the Vela pulsar, cannot be due to thermally activated vortex motion but must represent a different process, such as drag on vortices in regions where there is no pinning. I also derive the mutual friction force for a pinned superfluid at finite temperature for use in other studies of neutron star hydrodynamics.

  1. Effects of phase transition induced density fluctuations on pulser dynamics

    International Nuclear Information System (INIS)

    Bagchi, Partha; Das, Arpan; Srivastava, Ajit M.; Layek, Biswanath

    2016-01-01

    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. (author)

  2. Core temperature responses of military working dogs during training activities and exercise walks.

    Science.gov (United States)

    O'Brien, Catherine; Karis, Anthony J; Tharion, William J; Sullivan, Heather M; Hoyt, Reed W

    2017-01-01

    Heat strain is common in military working dogs (MWDs), but can be mitigated by limiting duration of activity to avoid overheating and allowing sufficient time for recovery. To determine work/rest times for MWDs, temperature responses during training must be characterized. This study measured body core temperature of 48 MWDs at Lackland Air Force Base, San Antonio, TX. Twenty-four MWDs in training for patrol and detection activities participated under a range of ambient temperatures in August (27°C-32°C), October (22°C-26°C) and March (approximately 13°C). These MWDs swallowed a telemetric thermometer pill to measure continuous gastrointestinal tract temperature (Tgi). Twenty-four kennel MWDs participated in July (25°C-29°C). In these dogs rectal temperature (Tre) was measured manually during a standard exercise walk. For the MWDs in training, Tgi before the first activity was 38.5±0.5°C (mean±SD) and final Tgi was 39.8±0.6°C after sessions that lasted 13.1±4.9 minutes (5.4 to 26.3 minutes). Peak Tgi, 0.4±0.4°C above final Tgi, occurred 8 to 12 minutes into recovery. Before beginning a second activity 40 to 165 minutes later, Tgi was within 0.5°C of initial values for 80% of dogs. For the kennel MWDs, Tre was 39.0±0.8°C (37.7°C to 40.7°C) at the start and 40.1±0.6°C at the end of the 21.3±2.8 minute walk. The continuous increase in core temperature during activity of both groups of MWDs indicates that limiting exercise duration is important for minimizing risk of overheating in MWDs. The observation of continued increase in Tgi to a peak after exercise ends suggests that for MWDs suspected of overheating temperature should be monitored for at least 15 minutes postexercise to ensure recovery.

  3. Fluctuations and Photons

    International Nuclear Information System (INIS)

    Gupta, Sourendu

    2007-01-01

    In this talk I discuss measures of fluctuations, especially those leading to the proof that the quark gluon plasma indeed contains quarks. I discuss the quark mass dependence of the critical end point of QCD. Then I discuss probes of the QCD critical point. Non-gaussian behaviour of event-to-event fluctuations of conserved quantum numbers is one such probe. Another is due to the coupling of fluctuations in baryon number and electrical charge, giving rise to long range random fluctuations of local charge density which relax slowly. These fluctuations can scatter photons, giving rise to critical opalescence

  4. Fluctuations and Photons

    Science.gov (United States)

    Gupta, Sourendu

    2007-02-01

    In this talk I discuss measures of fluctuations, especially those leading to the proof that the quark gluon plasma indeed contains quarks. I discuss the quark mass dependence of the critical end point of QCD. Then I discuss probes of the QCD critical point. Non-gaussian behaviour of event-to-event fluctuations of conserved quantum numbers is one such probe. Another is due to the coupling of fluctuations in baryon number and electrical charge, giving rise to long range random fluctuations of local charge density which relax slowly. These fluctuations can scatter photons, giving rise to critical opalescence.

  5. Fluctuations and Photons

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Sourendu [Department of Theoretical Physics, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)

    2007-02-15

    In this talk I discuss measures of fluctuations, especially those leading to the proof that the quark gluon plasma indeed contains quarks. I discuss the quark mass dependence of the critical end point of QCD. Then I discuss probes of the QCD critical point. Non-gaussian behaviour of event-to-event fluctuations of conserved quantum numbers is one such probe. Another is due to the coupling of fluctuations in baryon number and electrical charge, giving rise to long range random fluctuations of local charge density which relax slowly. These fluctuations can scatter photons, giving rise to critical opalescence.

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

    Energy Technology Data Exchange (ETDEWEB)

    Minati, Ludovico, E-mail: lminati@ieee.org, E-mail: ludovico.minati@unitn.it, E-mail: lminati@istituto-besta.it [Scientific Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan (Italy); Center for Mind/Brain Sciences, University of Trento, Trento (Italy); Chiesa, Pietro; Tabarelli, Davide; Jovicich, Jorge [Center for Mind/Brain Sciences, University of Trento, Trento (Italy); D' Incerti, Ludovico [Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan (Italy)

    2015-03-15

    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 (D{sub 2}), 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.

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

    International Nuclear Information System (INIS)

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

    2015-01-01

    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 (D 2 ), 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

  8. Construction of CdS@UIO-66-NH2 core-shell nanorods for enhanced photocatalytic activity with excellent photostability.

    Science.gov (United States)

    Liang, Qian; Cui, Sainan; Liu, Changhai; Xu, Song; Yao, Chao; Li, Zhongyu

    2018-08-15

    A novel class of CdS@UIO-66-NH 2 core shell heterojunction was fabricated by the facile in-situ solvothermal method. Characterizations show that porous UIO-66-NH 2 shell not only allows the visible light to be absorbed on CdS nanorod core, but also provides abundant catalytic active sites as well as an intimate heterojunction interface between UIO-66-NH 2 shell and CdS nanorod core. By taking advantage of this property, the core-shell composite presents highly solar-driven photocatalytic performance compared with pristine UIO-66-NH 2 and CdS nanorod for the degradation of organic dyes including malachite green (MG) and methyl orange (MO), and displays superior photostability after four recycles. Furthermore, the photoelectrochemical performance of CdS@UIO-66-NH 2 can be measured by the UV-vis spectra, Mott-Schottky plots and photocurrent. The remarkably enhanced photocatalytic activity of CdS@UIO-66-NH 2 can be ascribed to high surface areas, intimate interaction on molecular scale and the formation of one-dimensional heterojunction with n-n type. What's more, the core-shell heterostructural CdS@UIO-66-NH 2 can facilitate the effective separation and transfer of the photoinduced interfacial electron-hole pairs and protect CdS nanorod core from photocorrosion. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Controllable synthesis of Au@SnO2 core-shell nanohybrids with enhanced photocatalytic activities

    Science.gov (United States)

    Zhang, Shaofeng; Hao, Jinggang; Ren, Feng; Wu, Wei; Xiao, Xiangheng

    2017-05-01

    Combination of semiconductors with plasmonic nanostructures is an effective route to promote the solar light harvesting as well as the efficiency of photocatalysis. In the present work, the Au@SnO2 hybrid nanostructures with Au nanorods as the cores and highly crystallized SnO2 nanoparticles as the shells were fabricated by a facile hydrothermal method. A critical factor, which influences the coating state of the SnO2 shells over Au NRs, was found to be the concentration of CTAB agent in the system and the corresponding mechanism was also proposed. The photocatalytic activities of the Au@SnO2 nanohybrids were examined by degradation of rhodamine B (RhB) dyes at room temperature. The Au@SnO2 nanohybrids exhibited much higher catalytic activities than that of the commercial SnO2 NPs, which could be attributed to the localized electric field enhancement effect of Au nanorods plasmon and charges transfer between the Au nanorods and SnO2.

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

    Science.gov (United States)

    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.

  11. Neutron activation analysis of core and drill cutting samples from geothermal well drilling

    International Nuclear Information System (INIS)

    Miller, G.E.

    1986-01-01

    Samples of sandstones and shales were analysed by instrumental neutron activation analysis for a total of 30 elements. Three irradiation and five counting periods were employed. Solutions and National Bureau of Standards Reference Materials were used for comparison. The samples were obtained from drill cuttings (with a few core samples) from drillings in the Salton Sea geothermal field of California. These determinations form part of a major study to establish elemental variation as a function of mineral variation as depth and temperature in the well vary. The overall goal is to examine mineral alteration and/or element migration under typical geothermal conditions. The techniques involve typical compromises between maximizing precision for individual element determinations and the amount of time and effort that can be expended, as it is desired to examine large numbers of samples. With the limitations imposed by the reactor flux available at the U.C.Irvine TRIGA reactor, the detectors available, and time factors, most precisions are acceptable for geological comparison purposes. Some additional measurements were made by delayed-neutron counting methods to compare with uranium determinations made by conventional instrumental neutron activation analysis methods. (author)

  12. [Alkaline phosphatase activity in blood group B or O secretors is fluctuated by the dinner intake of previous night].

    Science.gov (United States)

    Matsushita, Makoto; Harajiri, Sanae; Tabata, Shiori; Yukimasa, Nobuyasu; Muramoto, Yoshimi; Komoda, Tsugikazu

    2013-04-01

    We previously reported that two intestinal alkaline phosphatase (IAP) isoforms, high molecular mass IAP (HIAP) and normal molecular mass IAP (NIAP), appear in healthy serum with our Triton-PAGE method for determination of ALP isozymes. In addition, HIAP is chiefly present in blood group B or O secretors, and a large amount of NIAP is secreted into the circulation after high-fat meal in blood group B or O secretors. In the present paper, we investigated the relationship between alkaline phosphatase (ALP) activity in early morning with the patient in a fasted state and the dinner intake of previous night. Two types of dinner were prepared; a low-fat meal (520 kcal), and a high-fat meal (1,040 kcal). Subjects ate the 2 types of dinner on different days. The mean ALP activities at 14 h after high-fat meal ingestion in blood group B or O secretors (n=14) from JSCC and IFCC methods were 8.8% and 5.2% higher than those at 14 h after low-fat meal ingestion in blood group B or O secretors, respectively. The increases in ALP activity between after high-fat meal and low-fat meal were nearly identical to the increases in NIAP activity. These results suggest that a high-fat meal is more likely to affect ALP activity at the early morning with the patient in a fasted state in blood group B or O secretors.

  13. TAF4 nucleates a core subcomplex of TFIID and mediates activated transcription from a TATA-less promoter

    OpenAIRE

    Wright, Kevin J.; Marr, Michael T.; Tjian, Robert

    2006-01-01

    Activator-dependent recruitment of TFIID initiates formation of the transcriptional preinitiation complex. TFIID binds core promoter DNA elements and directs the assembly of other general transcription factors, leading to binding of RNA polymerase II and activation of RNA synthesis. How TATA box-binding protein (TBP) and the TBP-associated factors (TAFs) are assembled into a functional TFIID complex with promoter recognition and coactivator activities in vivo remains unknown. Here, we use RNA...

  14. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W.; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H. Eric

    2017-01-01

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β2-adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. PMID:28356352

  15. Rearrangement of a polar core provides a conserved mechanism for constitutive activation of class B G protein-coupled receptors.

    Science.gov (United States)

    Yin, Yanting; de Waal, Parker W; He, Yuanzheng; Zhao, Li-Hua; Yang, Dehua; Cai, Xiaoqing; Jiang, Yi; Melcher, Karsten; Wang, Ming-Wei; Xu, H Eric

    2017-06-16

    The glucagon receptor (GCGR) belongs to the secretin-like (class B) family of G protein-coupled receptors (GPCRs) and is activated by the peptide hormone glucagon. The structures of an activated class B GPCR have remained unsolved, preventing a mechanistic understanding of how these receptors are activated. Using a combination of structural modeling and mutagenesis studies, we present here two modes of ligand-independent activation of GCGR. First, we identified a GCGR-specific hydrophobic lock comprising Met-338 and Phe-345 within the IC3 loop and transmembrane helix 6 (TM6) and found that this lock stabilizes the TM6 helix in the inactive conformation. Disruption of this hydrophobic lock led to constitutive G protein and arrestin signaling. Second, we discovered a polar core comprising conserved residues in TM2, TM3, TM6, and TM7, and mutations that disrupt this polar core led to constitutive GCGR activity. On the basis of these results, we propose a mechanistic model of GCGR activation in which TM6 is held in an inactive conformation by the conserved polar core and the hydrophobic lock. Mutations that disrupt these inhibitory elements allow TM6 to swing outward to adopt an active TM6 conformation similar to that of the canonical β 2 -adrenergic receptor complexed with G protein and to that of rhodopsin complexed with arrestin. Importantly, mutations in the corresponding polar core of several other members of class B GPCRs, including PTH1R, PAC1R, VIP1R, and CRFR1, also induce constitutive G protein signaling, suggesting that the rearrangement of the polar core is a conserved mechanism for class B GPCR activation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Hepatitis C virus core protein regulates p300/CBP co-activation function. Possible role in the regulation of NF-AT1 transcriptional activity

    International Nuclear Information System (INIS)

    Gomez-Gonzalo, Marta; Benedicto, Ignacio; Carretero, Marta; Lara-Pezzi, Enrique; Maldonado-Rodriguez, Alejandra; Moreno-Otero, Ricardo; Lai, Michael M.C.; Lopez-Cabrera, Manuel

    2004-01-01

    Hepatitis C virus (HCV) core is a viral structural protein; it also participates in some cellular processes, including transcriptional regulation. However, the mechanisms of core-mediated transcriptional regulation remain poorly understood. Oncogenic virus proteins often target p300/CBP, a known co-activator of a wide variety of transcription factors, to regulate the expression of cellular and viral genes. Here we demonstrate, for the first time, that HCV core protein interacts with p300/CBP and enhances both its acetyl-transferase and transcriptional activities. In addition, we demonstrate that nuclear core protein activates the NH 2 -terminal transcription activation domain (TAD) of NF-AT1 in a p300/CBP-dependent manner. We propose a model in which core protein regulates the co-activation function of p300/CBP and activates NF-AT1, and probably other p300/CBP-regulated transcription factors, by a novel mechanism involving the regulation of the acetylation state of histones and/or components of the transcriptional machinery

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

    International Nuclear Information System (INIS)

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

    2011-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Method for a reliable activation calculation of core components; Methode zur zuverlaessigen Berechnung von Aktivierungen in Kernbauteilen

    Energy Technology Data Exchange (ETDEWEB)

    Mispagel, T.; Phlippen, P.W.; Rose, J. [Wissenschaftlich-Technische Ingenieurberatung GmbH (WTI), Juelich (Germany)

    2013-07-01

    During nuclear power plant operation components and materials are exposed to the neutron flux from the reactor core and radionuclides are produced. After removal of the fuel elements the radioactivity of these radionuclides in the reactor pressure vessel and the core internals provide more than 99% of the activity of the power plant. For the transport, the interim storage and the final disposal of these radioactive components the radioactive inventories have to be decoded with respect to radiation and nuclides. The declaration of the nuclide and activity inventories requires a reliable calculation of neutron induced activation of reactor components. These activation calculations describe the pile-up of nuclides due to irradiation and due to the decay of nuclides. For an optimum usage of the activity capacities of the repository Konrad it is necessary to have a qualified calculation procedure that keeps the conservatism as low as possible.

  20. An active magnetic bearing with high Tc superconducting coils and ferromagnetic cores

    International Nuclear Information System (INIS)

    Brown, G.V.; DiRusso, E.; Provenza, A.J.

    1996-01-01

    A proof-of-feasibility demonstration showed that high-T c , superconductor (HTS) coils can be used in a high-load, active magnetic bearing in LN 2 . A homopolar radial bearing with commercially wound HTS (Bi 2223) bias and control coils produced over 890 N (200 lb) radial load capacity (measured nonrotating) and supported a shaft to 14000 rpm. The goal was to show that HTS coils can operate stably with ferromagnetic cores in a feedback controlled system at a current density similar to that for Cu in LN 2 . The bias coil, wound with nontwisted, multifilament HTS conductor, dissipated negligible power for its direct current. The control coils, wound with monofilament HTS sheathed in Ag, dissipated negligible power for direct current. AC losses increased rapidly with frequency and quadratically with AC amplitude. Above about 2 Hz, the effective resistance of the control coils exceeds that of the silver which is in electrical parallel with the oxide superconductor. These results show that twisted multifilament conductor is not needed for stable levitation but may be desired to reduce control power for sizable dynamic loads

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...... 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...

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

    Directory of Open Access Journals (Sweden)

    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. 76 FR 6839 - ActiveCore Technologies, Inc., Battery Technologies, Inc., China Media1 Corp., Dura Products...

    Science.gov (United States)

    2011-02-08

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] ActiveCore Technologies, Inc., Battery Technologies, Inc., China Media1 Corp., Dura Products International, Inc. (n/k/a Dexx Corp.), Global Mainframe Corp., GrandeTel Technologies, Inc., Magna Entertainment Corp. (n/k/a Reorganized Magna Entertainment...

  6. Cell cycle-related fluctuations in transcellular ionic currents and plasma membrane Ca2+/Mg2+ ATPase activity during early cleavages of Lymnaea stagnalis embryos.

    Science.gov (United States)

    Zivkovic, Danica; Créton, Robbert; Dohmen, René

    1991-08-01

    During the first four mitotic division cycles of Lymnaea stagnalis embryos, we have detected cell cycle-dependent changes in the pattern of transcellular ionic currents and membrane-bound Ca 2+ -stimulated ATPase activity. Ionic currents ranging from 0.05 to 2.50 μA/cm 2 have been measured using the vibrating probe technique. Enzyme activity was detected using Ando's cytochemical method (Ando et al. 1981) which reveals Ca 2+ /Mg 2+ ATPase localization at the ultrastructural level, and under high-stringency conditions with respect to calcium availability, it reveals Ca 2+ -stimulated ATPase. The ionic currents and Ca 2+ -stimulated ATPase localization have in common that important changes occur during the M-phase of the cell cycles. Minimal outward current at the vegetal pole coincides with metaphase/anaphase. Maximal inward current at the animal pole coincides with the onset of cytokinesis at that pole. Ca 2+ -stimulated ATPase is absent from one half of the embryo at metaphase/anaphase of the two- and four-cell stage, whereas it is present in all cells during the remaining part of the cell cycle. Since fluctuations of cytosolic free calcium concentrations appear to correlate with both karyokinesis and cytokinesis, we speculate that part of the cyclic pattern of Ca 2+ -stimulated ATPase localization and of the transcellular ionic currents reflects the elevation of cytosolic free calcium concentration during the M-phase.

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

    Energy Technology Data Exchange (ETDEWEB)

    Poochai, Chatwarin, E-mail: p_chatwarin@yahoo.com

    2017-02-28

    Highlights: • This is the first report on electrooxidation of 2-propanol in acidic media on dealloyed Cu@Pt/CP core-shell electrocatalyst. • The dealloyed Cu@Pt/CP is prepared using cyclic co-electrodeposition and selective Cu dealloying (CCEd-sCuD). • The structure of dealloyed Cu@Pt/CP is core-shell structure with Cu-rich core and Pt-rich surface. • The dealloyed Cu@Pt/CP shows high activity and great stability towards 2-propanol electrooxidation in acidic media. - Abstract: 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 H{sub 2}SO{sub 4} in terms of peak current density (j{sub p}), peak potential (E{sub p}), onset potential (E{sub onset}), diffusion coefficient (D), and charge transfer resistance (R{sub ct}) which were caused by electronic structure modification, higher compressive lattice strain, and larger ECSA, compared with Pt/CP.

  8. Superconductivity and spin fluctuations

    International Nuclear Information System (INIS)

    Scalapino, D.J.

    1999-01-01

    The organizers of the Memorial Session for Herman Rietschel asked that the author review some of the history of the interplay of superconductivity and spin fluctuations. Initially, Berk and Schrieffer showed how paramagnon spin fluctuations could suppress superconductivity in nearly-ferromagnetic materials. Following this, Rietschel and various co-workers wrote a number of papers in which they investigated the role of spin fluctuations in reducing the Tc of various electron-phonon superconductors. Paramagnon spin fluctuations are also believed to provide the p-wave pairing mechanism responsible for the superfluid phases of 3 He. More recently, antiferromagnetic spin fluctuations have been proposed as the mechanism for d-wave pairing in the heavy-fermion superconductors and in some organic materials as well as possibly the high-Tc cuprates. Here the author will review some of this early history and discuss some of the things he has learned more recently from numerical simulations

  9. The role of the shot effect in the accumulation of nuclide masses and activities in the thermal reactor core

    International Nuclear Information System (INIS)

    Nepoleao, P.; Rudak, E.; Wiley, J.

    1998-01-01

    A method is proposed for estimating masses and activities of nuclides in the thermal reactor core with an arbitrary dependence of specific masses on the burnout depth. The method takes into account the statistical character of micro processes accompanying the fuel burning out and accumulation of fission and activation products. For the RBMK reactor of Chernobyl NPP the method gives practically the same results as exact numerical calculations. (author)

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Ortodontia como atividade de meio ou resultado? Orthodontics as a support or core activity?

    Directory of Open Access Journals (Sweden)

    Erivaldo Ferreira Lopes

    2008-12-01

    Full Text Available Este trabalho apresenta a Ortodontia como atividade de meio, abordando as obrigações profissionais e as formas de se evitar e de se defender de ações judiciais. A grande parte dos litígios entre pacientes e ortodontistas se dá pelo fato equivocado, que ainda perdura, de que muitos juristas consideram a Ortodontia uma especialidade de fim, quando, na verdade, sua prática está sujeita a fatores que a caracterizam como atividade de meio. A Ortodontia deve ser, portanto, considerada uma obrigação de meio, onde o profissional tem o dever de utilizar todos os meios possíveis para atingir as expectativas do paciente, sem, entretanto, ter a obrigação de atingir o resultado idealizado. O ortodontista deve ser responsabilizado somente quando incorrer em imprudência, negligência, imperícia ou em caso de propaganda enganosa. Para evitar litígios, o ortodontista deve ter uma boa conduta profissional, registrando e mantendo arquivadas todas as etapas do tratamento, efetuando diagnósticos diferenciados, baseados nas características individuais, e escolhendo e conduzindo adequadamente o plano de tratamento.This study presents Orthodontics as a support activity, approaching professional obligations and ways to avoid and defend against legal action. A considerable part of litigation between patients and orthodontists results from the mistaken fact, which still persists, that many scholars regard Orthodontics as a core activity. In reality, its practice is subjected to factors that characterize it as a support activity. Orthodontics must be, therefore, regarded as a support obligation, whereupon the professional has the obligation to make use of all means possible to meet the patient's expectations - without, however, having the obligation to achieve the idealized result. The orthodontist must be made responsible only upon acts of imprudence, negligence, malpractice, or in the case of false advertising. In order to avoid litigation

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

    Science.gov (United States)

    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.

  13. An active homopolar magnetic bearing with high temperature superconductor (HTS) coils and ferromagnetic cores

    Science.gov (United States)

    Brown, G. V.; Dirusso, E.; Provenza, A. J.

    1995-01-01

    A proof-of-feasibility demonstration showed that high temperature superconductor (HTS) coils can be used in a high-load, active magnetic bearing in liquid nitrogen. A homopolar radial bearing with commercially wound HTS (Bi 2223) bias and control coils produced over 200 lb (890 N) radial load capacity (measured non-rotating) and supported a shaft to 14000 rpm. The goal was to show that HTS coils can operate stably with ferromagnetic cores in a feedback controlled system at a current density similar to that in Cu in liquid nitrogen. Design compromises permitted use of circular coils with rectangular cross section. Conductor improvements will eventually permit coil shape optimization, higher current density and higher bearing load capacity. The bias coil, wound with non-twisted, multifilament HTS conductor, required negligible power to carry its direct current. The control coils were wound with monofilament HTS sheathed in Ag. These dissipated negligible power for direct current (i.e. for steady radial load components). When an alternating current (AC) was added, the AC component dissipated power which increased rapidly with frequency and quadratically with AC amplitude. In fact at frequencies above about 2 hz, the effective resistance of the control coil conductor actually exceeds that of the silver which is in electrical parallel with the oxide superconductor. This is at least qualitatively understandable in the context of a Bean-type model of flux and current penetration into a Type II superconductor. Fortunately the dynamic currents required for bearing stability are of small amplitude. These results show that while twisted multifilament conductor is not needed for stable levitation, twisted multifilaments will be required to reduce control power for sizable dynamic loads, such as those due to unbalance.

  14. Heating mechanisms for intermittent loops in active region cores from AIA/SDO EUV observations

    Energy Technology Data Exchange (ETDEWEB)

    Cadavid, A. C.; Lawrence, J. K.; Christian, D. J. [Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330 (United States); Jess, D. B. [Astrophysics Research Centre, School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Nigro, G. [Universita della Calabria, Dipartimento di Fisica and Centro Nazionale Interuniversitario Struttura della Materia, Unita di Cosenza, I-87030 Arcavacata di Rende (Italy)

    2014-11-01

    We investigate intensity variations and energy deposition in five coronal loops in active region cores. These were selected for their strong variability in the AIA/SDO 94 Å intensity channel. We isolate the hot Fe XVIII and Fe XXI components of the 94 Å and 131 Å by modeling and subtracting the 'warm' contributions to the emission. HMI/SDO data allow us to focus on 'inter-moss' regions in the loops. The detailed evolution of the inter-moss intensity time series reveals loops that are impulsively heated in a mode compatible with a nanoflare storm, with a spike in the hot 131 Å signals leading and the other five EUV emission channels following in progressive cooling order. A sharp increase in electron temperature tends to follow closely after the hot 131 Å signal confirming the impulsive nature of the process. A cooler process of growing emission measure follows more slowly. The Fourier power spectra of the hot 131 Å signals, when averaged over the five loops, present three scaling regimes with break frequencies near 0.1 min{sup –1} and 0.7 min{sup –1}. The low frequency regime corresponds to 1/f noise; the intermediate indicates a persistent scaling process and the high frequencies show white noise. Very similar results are found for the energy dissipation in a 2D 'hybrid' shell model of loop magneto-turbulence, based on reduced magnetohydrodynamics, that is compatible with nanoflare statistics. We suggest that such turbulent dissipation is the energy source for our loops.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  16. Late Pleistocene and Holocene paleoclimate and alpine glacier fluctuations recorded by high-resolution grain-size data from an alpine lake sediment core, Wind River Range, Wyoming, USA

    Science.gov (United States)

    Thompson Davis, P.; Machalett, Björn; Gosse, John

    2013-04-01

    Varved lake sediments, which provide ideal high-resolution climate proxies, are not commonly available in many geographic areas over long time scales. This paper utilizes high-resolution grain-size analyses (n = 1040) from a 520-cm long sediment core from Lower Titcomb Lake (LTL), which lies just outside the type Titcomb Basin (TTB) moraines in the Wind River Range, Wyoming. The TTB moraines lie between Lower Titcomb Lake and Upper Titcomb Lake (UTL), about 3 km beyond, and 200 m lower than the modern glacier margin and Gannett Peak (Little Ice Age) moraines in the basin. Based on cosmogenic exposure dating, the TTB moraines are believed to be Younger Dryas (YD) age (Gosse et al., 1995) and lie in a geomorphic position similar to several other outer cirque moraines throughout the western American Cordillera. Until recently, many of these outer cirque moraines were believed to be Neoglacial age. The sediment core discussed here is one of five obtained from the two Titcomb Lakes, but is by the far the longest with the oldest sediment depositional record. Two AMS radiocarbon ages from the 445- and 455-cm core depths (about 2% loss on ignition, LOI) suggest that the lake basin may have been ice-free as early as 16.1 or even 16.8 cal 14C kyr, consistent with 10Be and 26Al exposure ages from boulders and bedrock surfaces outside the TTB moraines. The 257-cm depth in the core marks an abrupt transition from inorganic, sticky gray silt below (rock flour production between the 257 and 466 cm core depths appear to be roughly correlative with the YD-Alleröd-Bölling-Meiendorf-Heinrich 1 climate events recognized in other terrestrial records and Northern Atlantic Ocean marine cores, but provide much higher resolution than most of those records from a climate-sensitive alpine region in North America.

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

    DEFF Research Database (Denmark)

    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...... are responsible for the improvement of electrocatalytic activity and durability. The results obtained in this work are different from those previous reports, in which alloy walls with hollow interiors are usually formed. This work provides a new and simple method for synthesizing novel bimetallic core...

  18. Decrease of GSK3β phosphorylation in the rat nucleus accumbens core enhances cocaine-induced hyper-locomotor activity.

    Science.gov (United States)

    Kim, Wha Y; Jang, Ju K; Lee, Jung W; Jang, Hyunduk; Kim, Jeong-Hoon

    2013-06-01

    Glycogen synthase kinase 3β (GSK3β), which is abundantly present in the brain, is known to contribute to psychomotor stimulant-induced locomotor behaviors. However, most studies have been focused in showing that GSK3β is able to attenuate psychomotor stimulants-induced hyperactivity by increasing its phosphorylation levels in the nucleus accumbens (NAcc). So, here we examined in the opposite direction about the effects of decreased phosphorylation of GSK3β in the NAcc core on both basal and cocaine-induced locomotor activity by a bilateral microinjection into this site of an artificially synthesized peptide, S9 (0.5 or 5.0 μg/μL), which contains sequences around N-terminal serine 9 residue of GSK3β. We found that decreased levels of GSK3β phosphorylation in the NAcc core enhance cocaine-induced hyper-locomotor activity, while leaving basal locomotor activity unchanged. This is the first demonstration, to our knowledge, that the selective decrease of GSK3β phosphorylation levels in the NAcc core may contribute positively to cocaine-induced locomotor activity, while this is not sufficient for the generation of locomotor behavior by itself without cocaine. Taken together, these findings importantly suggest that GSK3β may need other molecular targets which are co-activated (or deactivated) by psychomotor stimulants like cocaine to contribute to generation of locomotor behaviors. © 2013 International Society for Neurochemistry.

  19. Dating an actively exhuming metamorphic core complex, the Suckling Dayman Massif in SE Papua New Guinea

    Science.gov (United States)

    Oesterle, J.; Seward, D.; Little, T.; Stockli, D. F.; Mizera, M.

    2016-12-01

    Low-temperature thermochronology is a powerful tool for revealing the thermal and kinematic evolution of metamorphic core complexes (MCCs). Most globally studied MCCs are ancient, partially eroded, and have been modified by deformation events that postdate their origin. The Mai'iu Fault is a rapidly slipping active low-angle normal fault (LANF) in the Woodlark Rift in Papua New Guinea that has exhumed a >25 km-wide (in the slip direction), and over 3 km-high domal fault surface in its footwall called the Suckling-Dayman massif. Some knowledge of the present-day thermal structure in the adjacent Woodlark Rift, and the pristine nature of this active MCC make it an ideal candidate for thermochronological study of a high finite-slip LANF. To constrain the thermal and kinematic evolution of this MCC we apply the U/Pb, fission-track (FT) and (U-Th)/He methods. Zircon U/Pb analyses from the syn-extensional Suckling Granite that intrudes the footwall of the MCC yield an intrusion age of 3.3 Ma. Preliminary zircon FT ages from the same body indicate cooling below 300 °C at 2.7 Ma. Ages decrease to 2.0 Ma with increasing proximity to the Mai'iu Fault and imply cooling controlled by tectonic exhumation. Almost coincident zircon U/Pb and FT ages from the nearby syn-extensional Mai'iu Monzonite, on the other hand, record extremely rapid cooling from magmatic temperatures to 300 °C at 2 Ma. As apparent from the preliminary He extraction stage, these syn-extensional plutons have young zircon and apatite (U-Th)/He ages. These initial results suggest that the Mai'iu Fault was initiated as an extensional structure by 3.3 Ma. We infer that it reactivated an older ophiolitic suture that had emplaced the Papuan Ultramafic body in the Paleogene. Rapid cooling of the Mai'iu Monzonite indicates that it was intruded into a part of the MCC's footwall that was already shallow in the crust by 2 Ma. This inference is further supported by the mineral andalusite occurring in the contact

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

    Science.gov (United States)

    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. Hadronic Correlations and Fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Quantum fluctuations and inflation

    International Nuclear Information System (INIS)

    Bardeen, J.M.; Bublik, G.J.

    1986-05-01

    We study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. We consider two different inflationary scenarios (new and chaotic inflation) and find that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. 8 refs., 2 figs

  3. Quantum fluctuations and inflation

    International Nuclear Information System (INIS)

    Bardeen, J.M.; Bublik, G.J.

    1987-01-01

    The authors study the effect of quantum fluctuations on the roll-down rate of the inflation field in a semiclassical approximation; this is done by treating the inflation field as a classical random field. The quantum fluctuations are simulated by a noise term in the equation of motion. Two different inflationary scenarios (new and chaotic inflation) are considered and it is found that the roll-down rate of the median value of the inflation field is increased by the quantum fluctuations. Non-linear effects may become important in the later stages of the inflationary regime. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  5. Constructing a Shared Mental Model for Faculty Development for the Core Entrustable Professional Activities for Entering Residency.

    Science.gov (United States)

    Favreau, Michele A; Tewksbury, Linda; Lupi, Carla; Cutrer, William B; Jokela, Janet A; Yarris, Lalena M

    2017-06-01

    In 2014, the Association of American Medical Colleges identified 13 Core Entrustable Professional Activities for Entering Residency (Core EPAs), which are activities that entering residents might be expected to perform without direct supervision. This work included the creation of an interinstitutional concept group focused on faculty development efforts, as the processes and tools for teaching and assessing entrustability in undergraduate medical education (UME) are still evolving. In this article, the authors describe a conceptual framework for entrustment that they developed to better prepare all educators involved in entrustment decision making in UME. This framework applies to faculty with limited or longitudinal contact with medical students and to those who contribute to entrustment development or render summative entrustment decisions.The authors describe a shared mental model for entrustment that they developed, based on a critical synthesis of the EPA literature, to serve as a guide for UME faculty development efforts. This model includes four dimensions for Core EPA faculty development: (1) observation skills in authentic settings (workplace-based assessments), (2) coaching and feedback skills, (3) self-assessment and reflection skills, and (4) peer guidance skills developed through a community of practice. These dimensions form a conceptual foundation for meaningful faculty participation in entrustment decision making.The authors also differentiate between the UME learning environment and the graduate medical education learning environment to highlight distinct challenges and opportunities for faculty development in UME settings. They conclude with recommendations and research questions for future Core EPA faculty development efforts.

  6. Microstructural investigations on carbonate fault core rocks in active extensional fault zones from the central Apennines (Italy)

    Science.gov (United States)

    Cortinovis, Silvia; Balsamo, Fabrizio; Storti, Fabrizio

    2017-04-01

    The study of the microstructural and petrophysical evolution of cataclasites and gouges has a fundamental impact on both hydraulic and frictional properties of fault zones. In the last decades, growing attention has been payed to the characterization of carbonate fault core rocks due to the nucleation and propagation of coseismic ruptures in carbonate successions (e.g., Umbria-Marche 1997, L'Aquila 2009, Amatrice 2016 earthquakes in Central Apennines, Italy). Among several physical parameters, grain size and shape in fault core rocks are expected to control the way of sliding along the slip surfaces in active fault zones, thus influencing the propagation of coseismic ruptures during earthquakes. Nevertheless, the role of grain size and shape distribution evolution in controlling the weakening or strengthening behavior in seismogenic fault zones is still not fully understood also because a comprehensive database from natural fault cores is still missing. In this contribution, we present a preliminary study of seismogenic extensional fault zones in Central Apennines by combining detailed filed mapping with grain size and microstructural analysis of fault core rocks. Field mapping was aimed to describe the structural architecture of fault systems and the along-strike fault rock distribution and fracturing variations. In the laboratory we used a Malvern Mastersizer 3000 granulometer to obtain a precise grain size characterization of loose fault rocks combined with sieving for coarser size classes. In addition, we employed image analysis on thin sections to quantify the grain shape and size in cemented fault core rocks. The studied fault zones consist of an up to 5-10 m-thick fault core where most of slip is accommodated, surrounded by a tens-of-meters wide fractured damage zone. Fault core rocks consist of (1) loose to partially cemented breccias characterized by different grain size (from several cm up to mm) and variable grain shape (from very angular to sub

  7. Active AirCore Sampling: Constraining Point Sources of Methane and Other Gases with Fixed Wing Unmanned Aerial Systems

    Science.gov (United States)

    Bent, J. D.; Sweeney, C.; Tans, P. P.; Newberger, T.; Higgs, J. A.; Wolter, S.

    2017-12-01

    Accurate estimates of point source gas emissions are essential for reconciling top-down and bottom-up greenhouse gas measurements, but sampling such sources is challenging. Remote sensing methods are limited by resolution and cloud cover; aircraft methods are limited by air traffic control clearances, and the need to properly determine boundary layer height. A new sampling approach leverages the ability of unmanned aerial systems (UAS) to measure all the way to the surface near the source of emissions, improving sample resolution, and reducing the need to characterize a wide downstream swath, or measure to the full height of the planetary boundary layer (PBL). The "Active-AirCore" sampler, currently under development, will fly on a fixed wing UAS in Class G airspace, spiraling from the surface to 1200 ft AGL around point sources such as leaking oil wells to measure methane, carbon dioxide and carbon monoxide. The sampler collects a 100-meter long sample "core" of air in an 1/8" passivated stainless steel tube. This "core" is run on a high-precision instrument shortly after the UAS is recovered. Sample values are mapped to a specific geographic location by cross-referencing GPS and flow/pressure metadata, and fluxes are quantified by applying Gauss's theorem to the data, mapped onto the spatial "cylinder" circumscribed by the UAS. The AirCore-Active builds off the sampling ability and analytical approach of the related AirCore sampler, which profiles the atmosphere passively using a balloon launch platform, but will add an active pumping capability needed for near-surface horizontal sampling applications. Here, we show design elements, laboratory and field test results for methane, describe the overall goals of the mission, and discuss how the platform can be adapted, with minimal effort, to measure other gas species.

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

    CERN Document Server

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  10. Fluorescence fluctuation spectroscopy (FFS)

    CERN Document Server

    Tetin, Sergey

    2012-01-01

    This new volume of Methods in Enzymology continues the legacy of this premier serial with quality chapters authored by leaders in the field. This volume covers fluorescence fluctuation spectroscopy and includes chapters on such topics as Förster resonance energy transfer (fret) with fluctuation algorithms, protein corona on nanoparticles by FCS, and FFS approaches to the study of receptors in live cells. Continues the legacy of this premier serial with quality chapters authored by leaders in the field Covers fluorescence fluctuation spectroscopy Contains chapters on such topics as Förster resonance energy transfer (fret) with fluctuation algorithms, protein corona on nanoparticles by FCS, and FFS approaches to the study of receptors in live cells.

  11. Fully Quantum Fluctuation Theorems

    Science.gov (United States)

    Åberg, Johan

    2018-02-01

    Systems that are driven out of thermal equilibrium typically dissipate random quantities of energy on microscopic scales. Crooks fluctuation theorem relates the distribution of these random work costs to the corresponding distribution for the reverse process. By an analysis that explicitly incorporates the energy reservoir that donates the energy and the control system that implements the dynamic, we obtain a quantum generalization of Crooks theorem that not only includes the energy changes in the reservoir but also the full description of its evolution, including coherences. Moreover, this approach opens up the possibility for generalizations of the concept of fluctuation relations. Here, we introduce "conditional" fluctuation relations that are applicable to nonequilibrium systems, as well as approximate fluctuation relations that allow for the analysis of autonomous evolution generated by global time-independent Hamiltonians. We furthermore extend these notions to Markovian master equations, implicitly modeling the influence of the heat bath.

  12. Measuring shape fluctuations in biological membranes

    International Nuclear Information System (INIS)

    Monzel, C; Sengupta, K

    2016-01-01

    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. (topical review)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

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

    Science.gov (United States)

    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…

  16. Research activities at JAERI on core material behaviour under severe accident conditions

    International Nuclear Information System (INIS)

    Uetsuka, H.; Katanashi, S.; Ishijima, K.

    1996-01-01

    At the Japan Atomic Energy Research Institute (JAERI), experimental studies on physical phenomena under the condition of a severe accident have been conducted. This paper presents the progress of the experimental studies on fuel and core materials behaviour such as the thermal shock fracture of fuel cladding due to quenching, the chemical interaction of core materials at high temperatures and the examination of TMI-2 debris. The mechanical behaviour of fuel rod with heavily embrittled cladding tube due to the thermal shock during delayed reflooding have been investigated at the Nuclear Safety Research Reactor (NSSR) of JAERI. A test fuel rod was heated in steam atmosphere by both electric and nuclear heating using the NSSR, then the rod was quenched by reflooding at the test section. Melting of core component materials having relatively low melting points and their eutectic reaction with other materials significantly influence on the degradation and melt down of fuel bundles during severe accidents. Therefore basic information on the reaction of core materials is necessary to understand and analyze the progress of core melting and relocation. Chemical interactions have been widely investigated at high temperatures for various binary systems of core component materials including absorber materials such as Zircaloy/Inconel, Zircaloy/stainless steel, Zircaloy/(Ag-In-Cd), stainless steel B 4 C and Zircaloy/B 4 C. It was found that the reaction generally obeyed a parabolic rate law and the reaction rate was determined for each reaction system. Many debris samples obtained from the degraded core of TMI-2 were transported to JAERI for numerous examinations and analyses. The microstructural examination revealed that the most part of debris was ceramic and it was not homogeneous in a microscopic sense. The thermal diffusivity data was also obtained for the temperature range up to about 1800K. The data from the large scale integral experiments were also obtained through the

  17. Fluctuation-dissipation relation and stationary distribution of an exactly solvable many-particle model for active biomatter far from equilibrium.

    Science.gov (United States)

    Netz, Roland R

    2018-05-14

    An exactly solvable, Hamiltonian-based model of many massive particles that are coupled by harmonic potentials and driven by stochastic non-equilibrium forces is introduced. The stationary distribution and the fluctuation-dissipation relation are derived in closed form for the general non-equilibrium case. Deviations from equilibrium are on one hand characterized by the difference of the obtained stationary distribution from the Boltzmann distribution; this is possible because the model derives from a particle Hamiltonian. On the other hand, the difference between the obtained non-equilibrium fluctuation-dissipation relation and the standard equilibrium fluctuation-dissipation theorem allows us to quantify non-equilibrium in an alternative fashion. Both indicators of non-equilibrium behavior, i.e., deviations from the Boltzmann distribution and deviations from the equilibrium fluctuation-dissipation theorem, can be expressed in terms of a single non-equilibrium parameter α that involves the ratio of friction coefficients and random force strengths. The concept of a non-equilibrium effective temperature, which can be defined by the relation between fluctuations and the dissipation, is by comparison with the exactly derived stationary distribution shown not to hold, even if the effective temperature is made frequency dependent. The analysis is not confined to close-to-equilibrium situations but rather is exact and thus holds for arbitrarily large deviations from equilibrium. Also, the suggested harmonic model can be obtained from non-linear mechanical network systems by an expansion in terms of suitably chosen deviatory coordinates; the obtained results should thus be quite general. This is demonstrated by comparison of the derived non-equilibrium fluctuation dissipation relation with experimental data on actin networks that are driven out of equilibrium by energy-consuming protein motors. The comparison is excellent and allows us to extract the non

  18. Fluctuation-dissipation relation and stationary distribution of an exactly solvable many-particle model for active biomatter far from equilibrium

    Science.gov (United States)

    Netz, Roland R.

    2018-05-01

    An exactly solvable, Hamiltonian-based model of many massive particles that are coupled by harmonic potentials and driven by stochastic non-equilibrium forces is introduced. The stationary distribution and the fluctuation-dissipation relation are derived in closed form for the general non-equilibrium case. Deviations from equilibrium are on one hand characterized by the difference of the obtained stationary distribution from the Boltzmann distribution; this is possible because the model derives from a particle Hamiltonian. On the other hand, the difference between the obtained non-equilibrium fluctuation-dissipation relation and the standard equilibrium fluctuation-dissipation theorem allows us to quantify non-equilibrium in an alternative fashion. Both indicators of non-equilibrium behavior, i.e., deviations from the Boltzmann distribution and deviations from the equilibrium fluctuation-dissipation theorem, can be expressed in terms of a single non-equilibrium parameter α that involves the ratio of friction coefficients and random force strengths. The concept of a non-equilibrium effective temperature, which can be defined by the relation between fluctuations and the dissipation, is by comparison with the exactly derived stationary distribution shown not to hold, even if the effective temperature is made frequency dependent. The analysis is not confined to close-to-equilibrium situations but rather is exact and thus holds for arbitrarily large deviations from equilibrium. Also, the suggested harmonic model can be obtained from non-linear mechanical network systems by an expansion in terms of suitably chosen deviatory coordinates; the obtained results should thus be quite general. This is demonstrated by comparison of the derived non-equilibrium fluctuation dissipation relation with experimental data on actin networks that are driven out of equilibrium by energy-consuming protein motors. The comparison is excellent and allows us to extract the non

  19. Altered intrinsic brain activities in patients with acute eye pain using amplitude of low-frequency fluctuation: a resting-state fMRI study

    Directory of Open Access Journals (Sweden)

    Pan Z

    2018-01-01

    Full Text Available Zhi-Ming Pan,1 Hai-Jun Li,1 Jing Bao,1 Nan Jiang,1 Qing Yuan,1 Shelby Freeberg,2 Pei-Wen Zhu,1 Lei Ye,1 Ming-Yang Ma,1 Xin Huang,1 Yi Shao1 1Department of Ophthalmology and Radiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, People’s Republic of China; 2Department of Ophthalmology, University of Florida, Gainesville, FL, USA Objective: Many previous studies have reported that pain symptoms can lead to significant brain function and anatomical changes, whereas the intrinsic brain activity changes in acute eye pain (EP patients remain unknown. Using the amplitude of low-frequency fluctuation (ALFF method, this study aimed to evaluate the spontaneous brain activity alterations and their relationships with clinical features in acute EP patients.Participants and methods: A total of 20 patients with EP (15 males and 5 females and 20 healthy controls (HCs; 15 males and 5 females closely matched in age, sex, and education underwent resting-state functional magnetic resonance imaging scans. The ALFF method was applied to assess spontaneous brain activity changes. The ALFF values of the EP patients were distinguished from those of the HCs using a receiver operating characteristic curve. Pearson’s correlation analysis was used to investigate the relationships between the mean ALFF signal values from many brain regions and the clinical features in EP patients.Results: Compared with the HCs, acute EP patients had significantly lower ALFF in the left and right precentral/postcentral gyrus and left precuneus. In contrast, acute EP patients showed higher ALFF values in the right and left parahippocampal gyri and left caudate. However, no relationship was observed between the mean ALFF signal values from the different areas and clinical manifestations in the acute EP patients.Conclusion: We demonstrated that acute EP patients showed abnormal intrinsic brain activities in the precentral/postcentral gyrus and limbic system

  20. Synthesis of bimetallic Pt-Pd core-shell nanocrystals and their high electrocatalytic activity modulated by Pd shell thickness

    Science.gov (United States)

    Li, Yujing; Wang, Zhi Wei; Chiu, Chin-Yi; Ruan, Lingyan; Yang, Wenbing; Yang, Yang; Palmer, Richard E.; Huang, Yu

    2012-01-01

    Bimetallic Pt-Pd core-shell nanocrystals (NCs) are synthesized through a two-step process with controlled Pd thickness from sub-monolayer to multiple atomic layers. The oxygen reduction reaction (ORR) catalytic activity and methanol oxidation reactivity of the core-shell NCs for fuel cell applications in alkaline solution are systematically studied and compared based on different Pd thickness. It is found that the Pd shell helps to reduce the over-potential of ORR by up to 50mV when compared to commercial Pd black, while generating up to 3-fold higher kinetic current density. The carbon monoxide poisoning test shows that the bimetallic NCs are more resistant to the CO poisoning than Pt NCs and Pt black. It is also demonstrated that the bimetallic Pt-Pd core-shell NCs can enhance the current density of the methanol oxidation reaction, lowering the over-potential by 35 mV with respect to the Pt core NCs. Further investigation reveals that the Pd/Pt ratio of 1/3, which corresponds to nearly monolayer Pd deposition on Pt core NCs, gives the highest oxidation current density and lowest over-potential. This study shows for the first time the systematic investigation of effects of Pd atomic shells on Pt-Pd bimetallic nanocatalysts, providing valuable guidelines for designing high-performance catalysts for fuel cell applications.Bimetallic Pt-Pd core-shell nanocrystals (NCs) are synthesized through a two-step process with controlled Pd thickness from sub-monolayer to multiple atomic layers. The oxygen reduction reaction (ORR) catalytic activity and methanol oxidation reactivity of the core-shell NCs for fuel cell applications in alkaline solution are systematically studied and compared based on different Pd thickness. It is found that the Pd shell helps to reduce the over-potential of ORR by up to 50mV when compared to commercial Pd black, while generating up to 3-fold higher kinetic current density. The carbon monoxide poisoning test shows that the bimetallic NCs are more

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

    Directory of Open Access Journals (Sweden)

    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

  2. A survey of core and support activities of communicable disease surveillance systems at operating-level CDCs in China.

    Science.gov (United States)

    Xiong, Weiyi; Lv, Jun; Li, Liming

    2010-11-17

    In recent years, problems like insufficient coordination, low efficiency, and heavy working load in national communicable disease surveillance systems in China have been pointed out by many researchers. To strengthen the national communicable disease surveillance systems becomes an immediate concern. Since the World Health Organization has recommended that a structured approach to strengthen national communicable disease surveillance must include an evaluation to existing systems which usually begins with a systematic description, we conducted the first survey for communicable disease surveillance systems in China, in order to understand the situation of core and support surveillance activities at province-level and county-level centers for disease control and prevention (CDCs). A nationwide survey was conducted by mail between May and October 2006 to investigate the implementation of core and support activities of the Notifiable Disease Reporting System (NDRS) and disease-specific surveillance systems in all of the 31 province-level and selected 14 county-level CDCs in Mainland China The comments on the performance of communicable disease surveillance systems were also collected from the directors of CDCs in this survey. The core activities of NDRS such as confirmation, reporting and analysis and some support activities such as supervision and staff training were found sufficient in both province-level and county-level surveyed CDCs, but other support activities including information feedback, equipment and financial support need to be strengthened in most of the investigated CDCs. A total of 47 communicable diseases or syndromes were under surveillance at province level, and 20 diseases or syndromes at county level. The activities among different disease-specific surveillance systems varied widely. Acute flaccid paralysis (AFP), measles and tuberculosis (TB) surveillance systems got relatively high recognition both at province level and county level. China has

  3. Transform and filtration methods in fluctuation analysis

    International Nuclear Information System (INIS)

    Saxe, R.F.

    1976-01-01

    Digitized fluctuation signals from an ex-core ion-chamber of a PWR were analysed to produce a Power Spectral Density, (PSD), curve by two means: (1) by digital filter techniques and (2) by a Fast Fourier Transform program. For both these methods, the effects of the precision of the input data were investigated and it is shown that reasonably good PSD curves may be obtained using very poor input precision. (author)

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

    Science.gov (United States)

    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

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

    KAUST Repository

    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.

  6. Antimicrobial active silver nanoparticles and silver/polystyrene core-shell nanoparticles prepared in room-temperature ionic liquid

    International Nuclear Information System (INIS)

    An Jing; Wang Desong; Luo Qingzhi; Yuan Xiaoyan

    2009-01-01

    Uniform silver nanoparticles and silver/polystyrene core-shell nanoparticles were successfully synthesized in a room temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate ([BMIM].BF 4 ). [BMIM].BF 4 plays a protective role to prevent the nanoparticles from aggregation during the preparation process. Transmission electron micrographs confirm that both silver nanoparticles and core-shell nanoparticles are regular spheres with the sizes in the range of 5-15 nm and 15-25 nm, respectively. The X-ray diffraction analysis reveals the face-centered cubic geometry of silver nanoparticles. The as-prepared nanoparticles were also characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, UV-vis diffuse reflectance spectroscopy and X-ray photoelectron spectroscopy. In addition, antimicrobial activities against E. coli and S. aureus were studied and the results show that both silver nanoparticles and core-shell nanoparticles possess excellent antimicrobial activities. The antimicrobial mechanism of the as-prepared nanoparticles was discussed.

  7. Reducing and measuring fluctuations in the MST RFP: Enhancement of energy confinement and measurement of the MHD dynamo

    International Nuclear Information System (INIS)

    Den Hartog, D.J.; Almagri, A.F.

    1996-09-01

    A three- to five-fold enhancement of the energy confinement time in a reversed-field pinch (RFP) has been achieved in the Madison Symmetric Torus (MST) by reducing the amplitude of tearing mode fluctuations responsible for anomalous transport in the core of the RFP. By applying a transient poloidal inductive electric field to flatten the current density profile, the fluctuation amplitude b/B decreases from 1.5% to 0.8%, the electron temperature T e0 increases from 250 eV to 370 eV, the ohmic input power decreases from 4.5 MW to approximately 1.5 MW, the poloidal beta β 0 increases from 6% to 9%, and the energy confinement time τ E increases from 1 ms to ∼5 ms in I φ = 340 kA plasmas with density n = 1 x 10 19 m -3 . Current profile control methods are being developed for the RFP in a program to eliminate transport associated with these current-gradient-driven fluctuations. In addition to controlling the amplitude of the tearing modes, we are vigorously pursuing an understanding of the physics of these fluctuations. In particular, plasma flow, both equilibrium and fluctuating, plays a critical role in a diversity of physical phenomena in MST. The key results: 1) Edge probe measurements show that the MHD dynamo is active in low collisionality plasmas, while at high collisionality a new mechanism, the 'electron diamagnetic dynamo,' is observed. 2) Core spectroscopic measurements show that the toroidal velocity fluctuations of the plasma are coherent with the large-scale magnetic tearing modes; the scalar product of these two fluctuating quantities is similar to that expected for the MHD dynamo electromotive force. 3) Toroidal plasma flow in MST exhibits large radial shear and can be actively controlled, including unlocking locked discharges, by modifying E r with a robust biased probe. 24 refs

  8. Neutron activation analysis of sediment core samples of Lake Erhai in southern China and a Salt Lake in India

    International Nuclear Information System (INIS)

    Toyoda, Kazuhiro; Shinozuka, Yoshitsugu; Miura, Masahiro; Moriyasu, Yuki

    2005-01-01

    The purpose of this research is in the verification of the hypothesis that the long-lived nuclide ratio of Th/Sc in the deposit sample dug up in the lake with the hinterland of the granite quality is the index of a past change of precipitation and of the event such as earthquakes. As a preceding step the relation between an environmental change and a climate change was studied by the measuring result of the ratio of Th/Sc by the neutron activation analysis about the digging core sample of the Nepalese Katmandu basin (For the past 700,000 years) and the core sample (For 40,000 years and 8,000 years of the past) in Lake Biwa. (H. Katsuta)

  9. Universal mesoscopic conductance fluctuations

    International Nuclear Information System (INIS)

    Evangelou, S.N.

    1992-01-01

    The theory of conductance fluctuations in disordered metallic systems with size large compared to the mean free path of the electron but small compared to localization length is considered. It is demonstrates that fluctuations have an universal character and are due to repulsion between levels and spectral rigidity. The basic fluctuation measures for the energy spectrum in the mesoscopic regime of disordered systems are consistent with the Gaussian random matrix ensemble predictions. Although our disordered electron random matrix ensemble does not belong to the Gaussian ensemble the two ensembles turn out to be essentially similar. The level repulsion and the spectral rigidity found in nuclear spectra should also be observed in the metallic regime of Anderson localization. 7 refs. (orig.)

  10. Spin fluctuations and the

    Directory of Open Access Journals (Sweden)

    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.

  11. The fluctuating gap model

    Energy Technology Data Exchange (ETDEWEB)

    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

  12. The fluctuating gap model

    International Nuclear Information System (INIS)

    Cao, Xiaobin

    2011-01-01

    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 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 quasi

  13. α-Glucosidase inhibitor miglitol attenuates glucose fluctuation, heart rate variability and sympathetic activity in patients with type 2 diabetes and acute coronary syndrome: a multicenter randomized controlled (MACS) study.

    Science.gov (United States)

    Shimabukuro, Michio; Tanaka, Atsushi; Sata, Masataka; Dai, Kazuoki; Shibata, Yoshisato; Inoue, Yohei; Ikenaga, Hiroki; Kishimoto, Shinji; Ogasawara, Kozue; Takashima, Akira; Niki, Toshiyuki; Arasaki, Osamu; Oshiro, Koichi; Mori, Yutaka; Ishihara, Masaharu; Node, Koichi

    2017-07-06

    Little is known about clinical associations between glucose fluctuations including hypoglycemia, heart rate variability (HRV), and the activity of the sympathetic nervous system (SNS) in patients with acute phase of acute coronary syndrome (ACS). This pilot study aimed to evaluate the short-term effects of glucose fluctuations on HRV and SNS activity in type 2 diabetes mellitus (T2DM) patients with recent ACS. We also examined the effect of suppressing glucose fluctuations with miglitol on these variables. This prospective, randomized, open-label, blinded-endpoint, multicenter, parallel-group comparative study included 39 T2DM patients with recent ACS, who were randomly assigned to either a miglitol group (n = 19) or a control group (n = 20). After initial 24-h Holter electrocardiogram (ECG) (Day 1), miglitol was commenced and another 24-h Holter ECG (Day 2) was recorded. In addition, continuous glucose monitoring (CGM) was performed throughout the Holter ECG. Although frequent episodes of subclinical hypoglycemia (≤4.44 mmo/L) during CGM were observed on Day 1 in the both groups (35% of patients in the control group and 31% in the miglitol group), glucose fluctuations were decreased and the minimum glucose level was increased with substantial reduction in the episodes of subclinical hypoglycemia to 7.7% in the miglitol group on Day 2. Holter ECG showed that the mean and maximum heart rate and mean LF/HF were increased on Day 2 in the control group, and these increases were attenuated by miglitol. When divided 24-h time periods into day-time (0700-1800 h), night-time (1800-0000 h), and bed-time (0000-0700 h), we found increased SNS activity during day-time, increased maximum heart rate during night-time, and glucose fluctuations during bed-time, which were attenuated by miglitol treatment. In T2DM patients with recent ACS, glucose fluctuations with subclinical hypoglycemia were associated with alterations of HRV and SNS activity, which were mitigated by

  14. Fluctuating Asymmetry and Intelligence

    Science.gov (United States)

    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…

  15. Engineering Ru@Pt Core-Shell Catalysts for Enhanced Electrochemical Oxygen Reduction Mass Activity and Stability

    Directory of Open Access Journals (Sweden)

    Ariel Jackson

    2018-01-01

    Full Text Available Improving the performance of oxygen reduction reaction (ORR electrocatalysts is essential for the commercial efficacy of many renewable energy technologies, including low temperature polymer electrolyte fuel cells (PEFCs. Herein, we report highly active and stable carbon-supported Ru@Pt core-shell nanoparticles (Ru@Pt/C prepared by a wet chemical synthesis technique. Through rotating disc electrode testing, the Ru@Pt/C achieves an ORR Pt mass-based activity of 0.50 A mgPt−1 at 0.9 V versus the reversible hydrogen electrode (RHE, which exceeds the activity of the state-of-the-art commercial Pt/C catalyst as well as the Department of Energy 2020 PEFC electrocatalyst activity targets for transportation applications. The impact of various synthetic parameters, including Pt to Ru ratios and catalyst pretreatments (i.e., annealing are thoroughly explored. Pt-based mass activity of all prepared Ru@Pt/C catalysts was found to exceed 0.4 mgPt−1 across the range of compositions investigated, with the maximum activity catalyst having a Ru:Pt ratio of 1:1. This optimized composition of Ru@Pt/C catalyst demonstrated remarkable stability after 30,000 accelerated durability cycles (0.6 to 1.0 V vs. RHE at 125 mV s−1, maintaining 85% of its initial mass activity. Scanning transmission electron microscopy energy dispersive spectroscopy (STEM-EDS analysis at various stages of electrochemical testing demonstrated that the Pt shell can provide sufficient protection against the dissolution of the otherwise unstable Ru core.

  16. Engineering Ru@Pt Core-Shell Catalysts for Enhanced Electrochemical Oxygen Reduction Mass Activity and Stability.

    Science.gov (United States)

    Jackson, Ariel; Strickler, Alaina; Higgins, Drew; Jaramillo, Thomas Francisco

    2018-01-12

    Improving the performance of oxygen reduction reaction (ORR) electrocatalysts is essential for the commercial efficacy of many renewable energy technologies, including low temperature polymer electrolyte fuel cells (PEFCs). Herein, we report highly active and stable carbon-supported Ru@Pt core-shell nanoparticles (Ru@Pt/C) prepared by a wet chemical synthesis technique. Through rotating disc electrode testing, the Ru@Pt/C achieves an ORR Pt mass-based activity of 0.50 A mg Pt -1 at 0.9 V versus the reversible hydrogen electrode (RHE), which exceeds the activity of the state-of-the-art commercial Pt/C catalyst as well as the Department of Energy 2020 PEFC electrocatalyst activity targets for transportation applications. The impact of various synthetic parameters, including Pt to Ru ratios and catalyst pretreatments (i.e., annealing) are thoroughly explored. Pt-based mass activity of all prepared Ru@Pt/C catalysts was found to exceed 0.4 mg Pt -1 across the range of compositions investigated, with the maximum activity catalyst having a Ru:Pt ratio of 1:1. This optimized composition of Ru@Pt/C catalyst demonstrated remarkable stability after 30,000 accelerated durability cycles (0.6 to 1.0 V vs. RHE at 125 mV s -1 ), maintaining 85% of its initial mass activity. Scanning transmission electron microscopy energy dispersive spectroscopy (STEM-EDS) analysis at various stages of electrochemical testing demonstrated that the Pt shell can provide sufficient protection against the dissolution of the otherwise unstable Ru core.

  17. Active core profile and transport modification by application of ion Bernstein wave power in the Princeton Beta Experiment-Modification

    Science.gov (United States)

    LeBlanc, B.; Batha, S.; Bell, R.; Bernabei, S.; Blush, L.; de la Luna, E.; Doerner, R.; Dunlap, J.; England, A.; Garcia, I.; Ignat, D.; Isler, R.; Jones, S.; Kaita, R.; Kaye, S.; Kugel, H.; Levinton, F.; Luckhardt, S.; Mutoh, T.; Okabayashi, M.; Ono, M.; Paoletti, F.; Paul, S.; Petravich, G.; Post-Zwicker, A.; Sauthoff, N.; Schmitz, L.; Sesnic, S.; Takahashi, H.; Talvard, M.; Tighe, W.; Tynan, G.; von Goeler, S.; Woskov, P.; Zolfaghari, A.

    1995-03-01

    Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH-assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large ∇ne, ∇Te, ∇νφ, and ∇Ti, delimiting the confinement zone. This regime is reminiscent of the H(high) mode, but with a confinement zone moved inward. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhances NBI core deposition and increases nuclear reactivity. An increase in central Ti results from χi reduction (compared to the H mode) and better beam penetration. Bootstrap current fractions of up to 0.32-0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma.

  18. Active core profile and transport modification by application of ion Bernstein wave power in the Princeton Beta Experiment-Modification

    International Nuclear Information System (INIS)

    LeBlanc, B.; Batha, S.; Bell, R.; Bernabei, S.; Blush, L.; de la Luna, E.; Doerner, R.; Dunlap, J.; England, A.; Garcia, I.; Ignat, D.; Isler, R.; Jones, S.; Kaita, R.; Kaye, S.; Kugel, H.; Levinton, F.; Luckhardt, S.; Mutoh, T.; Okabayashi, M.; Ono, M.; Paoletti, F.; Paul, S.; Petravich, G.; Post-Zwicker, A.; Sauthoff, N.; Schmitz, L.; Sesnic, S.; Takahashi, H.; Talvard, M.; Tighe, W.; Tynan, G.; von Goeler, S.; Woskov, P.; Zolfaghari, A.

    1995-01-01

    Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH-assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large ∇n e , ∇T e , ∇ν φ , and ∇T i , delimiting the confinement zone. This regime is reminiscent of the H(high) mode, but with a confinement zone moved inward. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhances NBI core deposition and increases nuclear reactivity. An increase in central T i results from χ i reduction (compared to the H mode) and better beam penetration. Bootstrap current fractions of up to 0.32--0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma

  19. Active core profile and transport modification by application of Ion Bernstein Wave power in PBX-M

    International Nuclear Information System (INIS)

    LeBlanc, B.; Bell, R.

    1995-01-01

    Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with the IBWH power deposition profile, is observed in the core of IBWH assisted neutral beam injection (NBI) discharges. A precursor to the fully developed barrier is seen in the soft x-ray data during edge localized mode (ELM) activity. Sustained IBWH operation is conducive to a regime where the barrier supports large triangledown n e , triangledown T e , triangledown v phi , and triangledown T i , delimiting the confinement zone. This regime is reminiscent of the H(high)-mode but with a confinement zone moved inwards. The core region has better than H-mode confinement while the peripheral region is L(low)-mode-like. The peaked profile enhanced NBI core deposition and increases nuclear reactivity. An increase in central T i results from χ i reduction (compared to H-mode) and better beam penetration. Bootstrap current fractions of up to 0.32--0.35 locally and 0.28 overall were obtained when an additional NBI burst is applied to this plasma

  20. The effect of surface-bulk potential difference on the kinetics of intercalation in core-shell active cathode particles

    Science.gov (United States)

    Kazemiabnavi, Saeed; Malik, Rahul; Orvananos, Bernardo; Abdellahi, Aziz; Ceder, Gerbrand; Thornton, Katsuyo

    2018-04-01

    Surface modification of active cathode particles is commonly observed in battery research as either a surface phase evolving during the cycling process, or intentionally engineered to improve capacity retention, rate capability, and/or thermal stability of the cathode material. Here, a continuum-scale model is developed to simulate the galvanostatic charge/discharge of a cathode particle with core-shell heterostructure. The particle is assumed to be comprised of a core material encapsulated by a thin layer of a second phase that has a different open-circuit voltage. The effect of the potential difference between the surface and bulk phases (Ω) on the kinetics of lithium intercalation and the galvanostatic charge/discharge profiles is studied at different values of Ω, C-rates, and exchange current densities. The difference between the Li chemical potential in the surface and bulk phases of the cathode particle results in a concentration difference between these two phases. This leads to a charge/discharge asymmetry in the galvanostatic voltage profiles, causing a decrease in the accessible capacity of the particle. These effects are more significant at higher magnitudes of surface-bulk potential difference. The proposed model provides detailed insight into the kinetics and voltage behavior of the intercalation/de-intercalation processes in core-shell heterostructure cathode particles.

  1. [Neurons in NAc core and BLA are activated during cocaine context-associated reward memory retrieval in mice].

    Science.gov (United States)

    Wang, Jun-Jun; Yao, Wen-Qing; Chen, Yue-Jun; Ma, Lan; Tao, Ye-Zheng

    2014-10-25

    The intense associative memories that develop between cocaine-paired contexts and rewarding stimuli make addiction hard to cure by contributing to cocaine seeking and relapse. So it's of great importance to examine the neurobiological basis of addiction memory. Cocaine conditioned place preference (CPP) used in this study is a form of Pavlovian conditioning which can establish associations between drug and contextual factors. c-Fos and Zif268 are commonly used immediate early gene (IEG) makers to identify neurons that are activated after a stimulus or behavioral conditioning. This study was designed to reveal neuronal c-Fos, Zif268 expression pattern in 10 brain regions following cocaine context-associated reward memory retrieval in mice, combining animal behavioral study and immunofluorescence method. C57BL/6 mice were randomly divided into 3 groups: Saline retrieval, Cocaine retrieval, and No retrieval of cocaine groups. Cocaine retrieval and No retrieval of cocaine underwent CPP training (one side paired with cocaine, and the other side with saline) except that No retrieval of cocaine group didn't undergo CPP test. Saline retrieval group received saline injections (i.p) on both sides. The results showed that: Neuronal c-Fos, Zif268 protein expression levels in nucleus accumbens (NAc) core both were elevated in Cocaine retrieval group compared with those in Saline retrieval (Control) group during cocaine context-associated reward memory retrieval. Zif268 protein expression level in basolateral amygdala (BLA) was also elevated in Cocaine retrieval group compared with that in control mice. Elevation was not seen in other regions such as hippocampus, prefrontal cortex (PFC). Thus, NAc core and BLA were activated during cocaine context-associated reward memory retrieval. The results suggest that neurons that are activated in NAc core and BLA are crucial basis of cocaine context-associated reward memory.

  2. Impairment of interferon regulatory factor-3 activation by hepatitis C virus core protein basic amino acid region 1.

    Science.gov (United States)

    Inoue, Kazuaki; Tsukiyama-Kohara, Kyoko; Matsuda, Chiho; Yoneyama, Mitsutoshi; Fujita, Takashi; Kuge, Shusuke; Yoshiba, Makoto; Kohara, Michinori

    2012-11-30

    Interferon regulatory factor-3 (IRF-3), a key transcriptional factor in the type I interferon system, is frequently impaired by hepatitis C virus (HCV), in order to establish persistent infection. However, the exact mechanism by which the virus establishes persistent infection has not been fully understood yet. The present study aimed to investigate the effects of various HCV proteins on IRF-3 activation, and elucidate the underlying mechanisms. To achieve this, full-length HCV and HCV subgenomic constructs corresponding to structural and each of the nonstructural proteins were transiently transfected into HepG2 cells. IFN-β induction, plaque formation, and IRF-3 dimerization were elicited by Newcastle disease virus (NDV) infection. The expressions of IRF-3 homodimer and its monomer, Ser386-phosphorylated IRF-3, and HCV core protein were detected by immunofluorescence and western blotting. IFN-β mRNA expression was quantified by real-time PCR (RT-PCR), and IRF-3 activity was measured by the levels of IRF-3 dimerization and phosphorylation, induced by NDV infection or polyriboinosinic:polyribocytidylic acid [poly(I:C)]. Switching of the expression of the complete HCV genome as well as the core proteins, E1, E2, and NS2, suppressed IFN-β mRNA levels and IRF-3 dimerization, induced by NDV infection. Our study revealed a crucial region of the HCV core protein, basic amino acid region 1 (BR1), to inhibit IRF-3 dimerization as well as its phosphorylation induced by NDV infection and poly (I:C), thus interfering with IRF-3 activation. Therefore, our study suggests that rescue of the IRF-3 pathway impairment may be an effective treatment for HCV infection. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. Fluctuations at electrode-YSZ interfaces

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hansen, Karin Vels; Skou, Eivind

    2005-01-01

    Current fluctuations at potentiostatically controlled point electrodes of Pt, La$_{0.85}$Sr$_{0.15}$MnO$_3$ and Ni on YSZ surfaces are determined at 1000$^\\circ$C. For the oxygen reduction process on Pt electrodes characteristic sawtooth shaped low frequency fluctuations are observed. At temperat......Current fluctuations at potentiostatically controlled point electrodes of Pt, La$_{0.85}$Sr$_{0.15}$MnO$_3$ and Ni on YSZ surfaces are determined at 1000$^\\circ$C. For the oxygen reduction process on Pt electrodes characteristic sawtooth shaped low frequency fluctuations are observed....../water atmosphere are presented for discussion. The origin of the observations is not known at present but it appears likely that they are related to the activation/deactivation mechanism of SOFCs....

  4. Central GLP-1 receptor activation modulates cocaine-evoked phasic dopamine signaling in the nucleus accumbens core.

    Science.gov (United States)

    Fortin, Samantha M; Roitman, Mitchell F

    2017-07-01

    Drugs of abuse increase the frequency and magnitude of brief (1-3s), high concentration (phasic) dopamine release events in terminal regions. These are thought to be a critical part of drug reinforcement and ultimately the development of addiction. Recently, metabolic regulatory peptides, including the satiety signal glucagon-like peptide-1 (GLP-1), have been shown to modulate cocaine reward-driven behavior and sustained dopamine levels after cocaine administration. Here, we use fast-scan cyclic voltammetry (FSCV) to explore GLP-1 receptor (GLP-1R) modulation of dynamic dopamine release in the nucleus accumbens (NAc) during cocaine administration. We analyzed dopamine release events in both the NAc shell and core, as these two subregions are differentially affected by cocaine and uniquely contribute to motivated behavior. We found that central delivery of the GLP-1R agonist Exendin-4 suppressed the induction of phasic dopamine release events by intravenous cocaine. This effect was selective for dopamine signaling in the NAc core. Suppression of phasic signaling in the core by Exendin-4 could not be attributed to interference with cocaine binding to one of its major substrates, the dopamine transporter, as cocaine-induced increases in reuptake were unaffected. The results suggest that GLP-1R activation, instead, exerts its suppressive effects by altering dopamine release - possibly by suppressing the excitability of dopamine neurons. Given the role of NAc core dopamine in the generation of conditioned responses based on associative learning, suppression of cocaine-induced dopamine signaling in this subregion by GLP-1R agonism may decrease the reinforcing properties of cocaine. Thus, GLP-1Rs remain viable targets for the treatment and prevention of cocaine seeking, taking and relapse. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Tests on the release of fission and activation products during core meltdown

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, H; Krause, W; Wild, H

    1976-01-01

    The first available results are related to tests in which the release of the main components of the core melt, namely the steel, zircaloy and uranium components, was determined using ThO/sub 2/ crucibles. The release products are dispersed onto the pipe walls of the transport system and the measuring filters which were installed at about 1 m distance from the melt crucibles. Of these, only the precipitates on the filters have been analyzed so far. In the tests under air, the release was clearly dependent on the maximum temperature reached. The release values for Mo and Mn were the highest with 5-10%; uranium with 0.1% on the other hand, was the lowest. In a steam atmosphere over the melt, the analysis of the filter precipitates for all elements gave considerably lower values than with the tests in air.

  8. Reconstitution of active human core Mediator complex reveals a pivotal role of the MED14 subunit

    Science.gov (United States)

    Cevher, Murat A.; Shi, Yi; Li, Dan; Chait, Brian T.; Malik, Sohail; Roeder, Robert G.

    2014-01-01

    The evolutionarily conserved Mediator complex is a critical coactivator for RNA polymerase II (Pol II)-mediated transcription. Here, we report the reconstitution of a functional 15-subunit human core Mediator complex and its characterization by functional assays and chemical cross-linking coupled to mass spectrometry (CX-MS). Whereas the reconstituted head and middle modules can stably associate, only with incorporation of MED14 into the bi-modular complex does it acquire basal and coactivator functions. This results from a dramatically enhanced ability of MED14-containing complexes to associate with Pol II. Altogether, our analyses identify MED14 as both an architectural and a functional backbone of the Mediator complex. We further establish a conditional requirement for metazoan-specific MED26 that becomes evident in the presence of heterologous nuclear factors. This general approach paves the way for systematically dissecting the multiple layers of functionalities associated with the Mediator complex. PMID:25383669

  9. Reconstitution of active human core Mediator complex reveals a critical role of the MED14 subunit.

    Science.gov (United States)

    Cevher, Murat A; Shi, Yi; Li, Dan; Chait, Brian T; Malik, Sohail; Roeder, Robert G

    2014-12-01

    The evolutionarily conserved Mediator complex is a critical coactivator for RNA polymerase II (Pol II)-mediated transcription. Here we report the reconstitution of a functional 15-subunit human core Mediator complex and its characterization by functional assays and chemical cross-linking coupled to MS (CX-MS). Whereas the reconstituted head and middle modules can stably associate, basal and coactivator functions are acquired only after incorporation of MED14 into the bimodular complex. This results from a dramatically enhanced ability of MED14-containing complexes to associate with Pol II. Altogether, our analyses identify MED14 as both an architectural and a functional backbone of the Mediator complex. We further establish a conditional requirement for metazoan-specific MED26 that becomes evident in the presence of heterologous nuclear factors. This general approach paves the way for systematic dissection of the multiple layers of functionality associated with the Mediator complex.

  10. Fabrication of Fe{sub 3}O{sub 4}@CuO core-shell from MOF based materials and its antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Rajabi, S.K. [Department of Chemistry, University of Guilan, University Campus 2, Rasht (Iran, Islamic Republic of); Sohrabnezhad, Sh., E-mail: sohrabnezhad@guilan.ac.ir [Department of Chemistry, Faculty of Science, University of Guilan, P.O. Box 1914, Rasht (Iran, Islamic Republic of); Ghafourian, S. [Clinical Microbiology Research Center, Ilam University of Medical Sciences, Ilam (Iran, Islamic Republic of)

    2016-12-15

    Magnetic Fe{sub 3}O{sub 4}@CuO nanocomposite with a core/shell structure was successfully synthesized via direct calcinations of magnetic Fe{sub 3}O{sub 4}@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 Fe{sub 3}O{sub 4} core and a CuO shell. The Fe{sub 3}O{sub 4}@CuO core-shell can be separated easily from the medium by a small magnet. The antibacterial activity of Fe{sub 3}O{sub 4}-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. - Graphical abstract: Fe{sub 3}O{sub 4}@CuO core-shell release of copper ions. These Cu{sup 2+} ions were responsible for the exhibited antibacterial activity. - Highlights: • The Fe{sub 3}O{sub 4}@CuO core-shell was prepared by MOF method. • This is the first study of antibacterial activity of core-shell consist of CuO and Fe{sub 3}O{sub 4}. • The core-shell can be reused effectively. • Core-shell was separated from the reaction solution by external magnetic field.

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

    Science.gov (United States)

    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.

  12. Controlling fluctuations in an ITB and comparison with gyrokinetic simulations

    Science.gov (United States)

    Ernst, D. R.; Fiore, C. L.; Dominguez, A.; Podpaly, Y.; Reinke, M. L.; Terry, J. L.; Tsujii, N.; Bespamyatnov, I.; Churchill, M.; Greenwald, M.; Hubbard, A.; Hughes, J. W.; Lee, J.; Ma, Y.; Wolfe, S.; Wukitch, S.

    2011-10-01

    We have modulated on-axis ICRF minority heating to trigger fluctuations and core electron transport in Alcator C-Mod Internal Transport Barriers (ITB's). Temperature swings of 50% produced strong bursts of density fluctuations, measured by phase contrast imaging (PCI), while edge fluctuations from reflectometry, Mirnov coils, and gas puff imaging (GPI) simultaneously diminished. The PCI fluctuations are in phase with sawteeth, further evidence that they originate within the ITB foot. Linear gyrokinetic analysis with GS2 shows TEMs are driven unstable in the ITB by the on-axis heating, as in Refs.,. Nonlinear gyrokinetic simulations of turbulence in the ITB are compared with fluctuation data using a synthetic diagnostic. Strong ITB's were produced with high quality ion and electron profile data. Supported by U.S. DoE awards DE-FC02-99ER54512, DE-FG02-91ER54109, DE-FC02-08ER54966.

  13. In Vivo antiplatelet activity aggregation assay of bromelain fractionate by ethanol from extract pineapple core (Ananas comosus [l.] merr.)

    Science.gov (United States)

    Musfiroh, F. F.; Setiasih, S.; Handayani, S.; Hudiyono, S.; Ilyas, N. M.

    2018-01-01

    Processed fruit from pineapple is one of largest commodities tropical fruit production in Indonesia and will bring the waste from the skin and core. This study aims to isolate bromelain from the pineapple core (Ananas comusus) are purified by fractionation using ethanol and continued by activity test as an antiplatelets agent by in vivo method using white mice male ddy type with acetosal as positive control. Fractionation of crude enzyme bromelain with ethanol produces highest specific activity on ethanol 30-60% fraction (fraction 2) 3.107 Unit/mg and the protein content 61.25 mg with the degree of purity of 155 times compared to crude enzyme. Antiplatelet aggregation tests from in vivo method shows that faction of bromelain with doses 70 μg/KgBW, 140 μg/KgBW, and 210 μg/KgBW can increase a meaningful bleeding time. The highest percentage of increase shown by the isolate at a dose of 210 μg/KgBW in the amount of 515.10 ± 182.23%, when compared to aspirin (231.20 ± 140.66), the value is relatively higher.

  14. Fluctuations in quantum devices

    Directory of Open Access Journals (Sweden)

    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.

  15. Status and prospects of activities on algorithms and methods in WWER-1000 core control

    International Nuclear Information System (INIS)

    Filimonov, P.; Krainov, Y.; Proselkov, V.

    1994-01-01

    On the basis of long-term operational experience and investigations the problems of WWER-1000 reactor control are discussed. Such control is needed for WWER-1000, as well as for its Western analog PWR, for suppressing the axially instable power density field resulted from non-equilibrium redistribution of Xe-135 nuclei in the reactor core. It has been found that an adequate assessment of the reactor state and the prediction of its response to various control actions is essential for the control of power density distribution. For this purpose a computerized operator's adviser with a reactor simulator realizing a physical reactor model based on BIPR-7 code is used. The operation experience of WWER-1000 shows that the available control algorithms allow, with a fair degree of assurance, the prevention of intensive xenon oscillations and the stabilization of the axial offset. But in connection with the renunciation of half-length control rods a new algorithm is under development which makes use of full-length control rods for suppressing the intensive xenon oscillations in the descending phase. A new method based on BIPR-7 and PERMAK codes is also being developed for estimating the value and rate of linear power rating change of the fuel elements in power cycling. 12 figs., 7 refs

  16. Status and prospects of activities on algorithms and methods in WWER-1000 core control

    Energy Technology Data Exchange (ETDEWEB)

    Filimonov, P; Krainov, Y; Proselkov, V [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    1994-12-31

    On the basis of long-term operational experience and investigations the problems of WWER-1000 reactor control are discussed. Such control is needed for WWER-1000, as well as for its Western analog PWR, for suppressing the axially instable power density field resulted from non-equilibrium redistribution of Xe-135 nuclei in the reactor core. It has been found that an adequate assessment of the reactor state and the prediction of its response to various control actions is essential for the control of power density distribution. For this purpose a computerized operator`s adviser with a reactor simulator realizing a physical reactor model based on BIPR-7 code is used. The operation experience of WWER-1000 shows that the available control algorithms allow, with a fair degree of assurance, the prevention of intensive xenon oscillations and the stabilization of the axial offset. But in connection with the renunciation of half-length control rods a new algorithm is under development which makes use of full-length control rods for suppressing the intensive xenon oscillations in the descending phase. A new method based on BIPR-7 and PERMAK codes is also being developed for estimating the value and rate of linear power rating change of the fuel elements in power cycling. 12 figs., 7 refs.

  17. Density Fluctuations in a Polar Coronal Hole

    Science.gov (United States)

    Hahn, Michael; D’Huys, Elke; Savin, Daniel Wolf

    2018-06-01

    We have measured the root-mean-square (rms) amplitude of intensity fluctuations, ΔI, in plume and interplume regions of a polar coronal hole. These intensity fluctuations correspond to density fluctuations. Using data from the Sun Watcher using the Active Pixel System detector and Image Processing on the Project for Onboard Autonomy (Proba2), our results extend up to a height of about 1.35 R ⊙. One advantage of the rms analysis is that it does not rely on a detailed evaluation of the power spectrum, which is limited by noise levels to low heights in the corona. The rms approach can be performed up to larger heights where the noise level is greater, provided that the noise itself can be quantified. At low heights, both the absolute ΔI, and the amplitude relative to the mean intensity, ΔI/I, decrease with height. However, starting at about 1.2 R ⊙, ΔI/I increases, reaching 20%–40% by 1.35 R ⊙. This corresponds to density fluctuations of Δn e/n e ≈ 10%–20%. The increasing relative amplitude implies that the density fluctuations are generated in the corona itself. One possibility is that the density fluctuations are generated by an instability of Alfvén waves. This generation mechanism is consistent with some theoretical models and with observations of Alfvén wave amplitudes in coronal holes. Although we find that the energy of the observed density fluctuations is small, these fluctuations are likely to play an important indirect role in coronal heating by promoting the reflection of Alfvén waves and driving turbulence.

  18. Fluctuations and Instability in Sedimentation

    KAUST Repository

    Guazzelli, É lisabeth; Hinch, John

    2011-01-01

    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

  19. Statistical fluctuations in reactors (1960); Fluctuations statistiques dans les piles (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The theory of space dependent fluctuations is developed, taking into account the effect of delayed neutrons. The 'diffusion equation' or Fokker-Planck equation is worked out in the case of age and two group theory, but the first one because of in physical significance is used in this report. The theory is applied to the study of the spectral density of fluctuations and fluctuations of counting rate and current flowing through the charge resistor of an ionisation chamber, the effect of the entrance capacity is discussed. The space dependent theory shows that the fluctuations in the core and reflector of a near critical pile obey to the same law. The spectral densities in the core and reflector are similar, there is no sensible attenuation of high frequency fluctuations in the reflector. Compared to the space independent theory, this theory give better agreement with experience, one can use the simple space independent theory but in checking with experiment it is necessary to introduce numerical factors given by the space dependent theory. (author) [French] La theorie des fluctuations statistiques est developpee dans le cas spatial en tenant compte des neutrons retardes, et dans le cadre de la theorie de l'age vitesse. L'equation d'evolution de la probabilite est egalement etablie dans le cadre de la theorie a deux groupes. Ces considerations sont appliquees a l'etude de la densite spectrale des fluctuations et aux fluctuations des taux de comptage et du courant circulant dans la resistance de charge du detecteur. On etudie en particulier l'effet de la constante de temps introduite par la capacite d'entree. Cette theorie etablit que les fluctuations dans le coeur et le reflecteur suivent la meme loi pour une pile critique, il en est de meme pour la densite spectrale meme a frequence elevee. Par rapport a la theorie d'ensemble, la theorie spatiale donne des coefficients numeriques ou facteurs de forme, qui permettent d'obtenir un bon accord entre la theorie et l

  20. Core Angular Momentum and the IERS Sub-Centers Activity for Monitoring Global Geophysical Fluids. Part 1; Core Angular Momentum and Earth Rotation

    Science.gov (United States)

    Song, Xia-Dong; Chao, Benjamin (Technical Monitor)

    1999-01-01

    The part of the grant was to use recordings of seismic waves travelling through the earth's core (PKP waves) to study the inner core rotation and constraints on possible density anomalies in the fluid core. The shapes and relative arrival times of such waves associated with a common source were used to reduce the uncertainties in source location and excitation and the effect of unknown mantle structure. The major effort of the project is to assemble historical seismograms with long observing base lines. We have found original paper records of SSI earthquakes at COL between 1951 and 1966 in a warehouse of the U.S. Geological Survey office in Golden, Colorado, extending the previous measurements at COL by Song and Richards [1996] further back 15 years. Also in Alaska, the University of Alaska, Fairbanks Geophysical Institute (UAFGI) has been operating the Alaskan Seismic Network with over 100 stations since the late 1960s. Virtually complete archives of seismograms are still available at UAFGI. Unfortunately, most of the archives are in microchip form (develocorders), for which the use of waveforms is impossible. Paper seismograms (helicorders) are available for a limited number of stations, and digital recordings of analog signals started around 1989. Of the paper records obtained, stations at Gilmore Dome (GLM, very close to COL), Yukon (FYU), McKinley (MCK), and Sheep Creek Mountain (SCM) have the most complete continuous recordings.

  1. Proteomics Core

    Data.gov (United States)

    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...

  2. The shifting study of the active core or a VHTR based on the TRISO packing fraction changing

    Energy Technology Data Exchange (ETDEWEB)

    Silva, F.C.; Pereira, C.; Veloso, M.A.F., E-mail: claubia@nuclear.ufmg.br, E-mail: antonella@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br [Departamento de Engenharia Nuclear. Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Costa, A.L. [Instituto Nacional de Ciencias e Tecnologia de Reatores Nucleares Inovadores (CNPq), Brasilia, DF (Brazil)

    2011-07-01

    A simplified VHTR core was analyzed, loaded with a fuel mixture of uranium oxide together with reprocessed transuranic nuclides. The TRUs were reprocessed together with Pu, Am, Np and Cm (23.80%) from PWR spent fuel, and dissolved in depleted uranium (0.2% {sup 235}U) until obtain 15% LEU-fuel ({sup 235}U, {sup 239}Pu and {sup 241}Pu). The shifting study of the active core was based on changes in the TRISO particle. Five cases were analyzed changing the VM/VF ratio (moderator volume/ fuel volume) making changes in the TRISO packing fraction (tpf), where tpf represents the ratio of TRISO particle on the fuel pin. The fuels were evaluated during the burnup up to 100,000.0 MWd/THM, during 990 days and without reloads. Then, it evaluated the multiplication (k{sub eff}) at zero and full power, fuel temperature coefficient ({alpha}{sub TF}), moderator temperature coefficient ({alpha}{sub TM}), and fuel composition at BOL (begin of life) and EOL (end of life), using the code Winfrith Improved Multi-Group Scheme (WIMSD5). The results show an overall heavy metal decrease in relation to the total TRU, with some Pu and Np being transmuted in the VHTR core. The results also clearly show the advantage of using reprocessed fuel in VHTR. It decreases the impact of the final spent fuel deposition, minimizes the cost of new fuel using reprocessed fuel and depleted uranium and demonstrated the promising neutronic behavior of the new types of nuclear reactors. (author)

  3. Fluctuations in Schottky barrier heights

    International Nuclear Information System (INIS)

    Mahan, G.D.

    1984-01-01

    A double Schottky barrier is often formed at the grain boundary in polycrystalline semiconductors. The barrier height is shown to fluctuate in value due to the random nature of the impurity positions. The magnitude of the fluctuations is 0.1 eV, and the fluctuations cause the barrier height measured by capacitance to differ from the one measured by electrical conductivity

  4. Fluctuating nonlinear hydrodynamics of flocking

    Science.gov (United States)

    Yadav, Sunil Kumar; Das, Shankar P.

    2018-03-01

    Starting from a microscopic model, the continuum field theoretic description of the dynamics of a system of active ingredients or "particles" is presented. The equations of motion for the respective collective densities of mass and momentum follow exactly from that of a single element in the flock. The single-particle dynamics has noise and anomalous momentum dependence in its frictional terms. The equations for the collective densities are averaged over a local equilibrium distribution to obtain the corresponding coarse grained equations of fluctuating nonlinear hydrodynamics (FNH). The latter are the equations used frequently for describing active systems on the basis of intuitive arguments. The transport coefficients which appear in the macroscopic FNH equations are determined in terms of the parameters of the microscopic dynamics.

  5. Spark-safe mechanical fluctuation sensor

    Energy Technology Data Exchange (ETDEWEB)

    Retek, S; Galisz, T

    1979-04-20

    The subject of the invention is a mechanical fluctuation sensor in a spark-safe design for use at mines which are dangerous for gas, as an element of different systems for remote control information transfer. The patented sensor of mechanical fluctuations contains: magnetic-induction transformer characterized by the fact that its inert mass consists of a plane permanent magnet placed in the suspended state on springs between 2 coils, which together with their cores are rigidly fixed to the walls of the ferromagnetic vessels. The ends of the coil windings are interconnected, while the beginnings of the windings are lead out with connection to the outlet of the electronic amplifier with binary outlet signal. The electronic amplifier is placed between the transformer in the common ferromagnetic housing which is a screen for protection from the effect of external magnetic fields.

  6. EFFECT OF ACTIVE COOLING AND α-2 ADRENOCEPTOR ANTAGONISM ON CORE TEMPERATURE IN ANESTHETIZED BROWN BEARS (URSUS ARCTOS).

    Science.gov (United States)

    Ozeki, Larissa Mourad; Caulkett, Nigel; Stenhouse, Gordon; Arnemo, Jon M; Fahlman, Åsa

    2015-06-01

    Hyperthermia is a common complication during anesthesia of bears, and it can be life threatening. The objective of this study was to evaluate the effectiveness of active cooling on core body temperature for treatment of hyperthermia in anesthetized brown bears (Ursus arctos). In addition, body temperature after reversal with atipamezole was also evaluated. Twenty-five adult and subadult brown bears were captured with a combination of zolazepam-tiletamine and xylazine or medetomidine. A core temperature capsule was inserted into the bears' stomach or 15 cm into their rectum or a combination of both. In six bears with gastric temperatures≥40.0°C, an active cooling protocol was performed, and the temperature change over 30 min was analyzed. The cooling protocol consisted of enemas with 2 L of water at approximately 5°C/100 kg of body weight every 10 min, 1 L of intravenous fluids at ambient temperature, water or snow on the paws or the inguinal area, intranasal oxygen supplementation, and removing the bear from direct sunlight or providing shade. Nine bears with body temperature>39.0°C that were not cooled served as control for the treated animals. Their body temperatures were recorded for 30 min, prior to administration of reversal. At the end of the anesthetic procedure, all bears received an intramuscular dose of atipamezole. In 10 bears, deep rectal temperature change over 30 min after administration of atipamezole was evaluated. The active cooling protocol used in hyperthermic bears significantly decreased their body temperatures within 10 min, and it produced a significantly greater decrease in their temperature than that recorded in the control group.

  7. Highly Active, Carbon-supported, PdSn Nano-core, Partially ...

    African Journals Online (AJOL)

    Carbon-supported, Pt partially covered, PdSn alloy nanoparticles (Pt-PdSn/C) were synthesized via a metathetical reaction of PdSn alloy nanoparticles, and a platinum precursor. The electrochemical activity was evaluated by methanol oxidation. The Pt-PdSn/C catalysts were characterized by transmission electron ...

  8. Mathematical prediction of core body temperature from environment, activity, and clothing: The heat strain decision aid (HSDA).

    Science.gov (United States)

    Potter, Adam W; Blanchard, Laurie A; Friedl, Karl E; Cadarette, Bruce S; Hoyt, Reed W

    2017-02-01

    Physiological models provide useful summaries of complex interrelated regulatory functions. These can often be reduced to simple input requirements and simple predictions for pragmatic applications. This paper demonstrates this modeling efficiency by tracing the development of one such simple model, the Heat Strain Decision Aid (HSDA), originally developed to address Army needs. The HSDA, which derives from the Givoni-Goldman equilibrium body core temperature prediction model, uses 16 inputs from four elements: individual characteristics, physical activity, clothing biophysics, and environmental conditions. These inputs are used to mathematically predict core temperature (T c ) rise over time and can estimate water turnover from sweat loss. Based on a history of military applications such as derivation of training and mission planning tools, we conclude that the HSDA model is a robust integration of physiological rules that can guide a variety of useful predictions. The HSDA model is limited to generalized predictions of thermal strain and does not provide individualized predictions that could be obtained from physiological sensor data-driven predictive models. This fully transparent physiological model should be improved and extended with new findings and new challenging scenarios. Published by Elsevier Ltd.

  9. Strain fluctuations and elastic constants

    Energy Technology Data Exchange (ETDEWEB)

    Parrinello, M.; Rahman, A.

    1982-03-01

    It is shown that the elastic strain fluctuations are a direct measure of elastic compliances in a general anisotropic medium; depending on the ensemble in which the fluctuation is measured either the isothermal or the adiabatic compliances are obtained. These fluctuations can now be calculated in a constant enthalpy and pressure, and hence, constant entropy, ensemble due to recent develpments in the molecular dynamics techniques. A calculation for a Ni single crystal under uniform uniaxial 100 tensile or compressive load is presented as an illustration of the relationships derived between various strain fluctuations and the elastic modulii. The Born stability criteria and the behavior of strain fluctuations are shown to be related.

  10. Sports Cardiology: Core Curriculum for Providing Cardiovascular Care to Competitive Athletes and Highly Active People.

    Science.gov (United States)

    Baggish, Aaron L; Battle, Robert W; Beckerman, James G; Bove, Alfred A; Lampert, Rachel J; Levine, Benjamin D; Link, Mark S; Martinez, Matthew W; Molossi, Silvana M; Salerno, Jack; Wasfy, Meagan M; Weiner, Rory B; Emery, Michael S

    2017-10-10

    The last few decades have seen substantial growth in the populations of competitive athletes and highly active people (CAHAP). Although vigorous physical exercise is an effective way to reduce the risk of cardiovascular (CV) disease, CAHAP remain susceptible to inherited and acquired CV disease, and may be most at risk for adverse CV outcomes during intense physical activity. Traditionally, multidisciplinary teams comprising athletic trainers, physical therapists, primary care sports medicine physicians, and orthopedic surgeons have provided clinical care for CAHAP. However, there is increasing recognition that a care team including qualified CV specialists optimizes care delivery for CAHAP. In recognition of the increasing demand for CV specialists competent in the care of CAHAP, the American College of Cardiology has recently established a Sports and Exercise Council. An important primary objective of this council is to define the essential skills necessary to practice effective sports cardiology. Copyright © 2017. Published by Elsevier Inc.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    using a mixed methods approach. Based on this it is concluded that laboratory studies are important research tools and that clear and definable relationships do exist between design activity in practice and the laboratory. © 2013 Elsevier Ltd. All rights reserved....... 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......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...

  12. Gambling with Superconducting Fluctuations

    Science.gov (United States)

    Foltyn, Marek; Zgirski, Maciej

    2015-08-01

    Josephson junctions and superconducting nanowires, when biased close to superconducting critical current, can switch to a nonzero voltage state by thermal or quantum fluctuations. The process is understood as an escape of a Brownian particle from a metastable state. Since this effect is fully stochastic, we propose to use it for generating random numbers. We present protocol for obtaining random numbers and test the experimentally harvested data for their fidelity. Our work is prerequisite for using the Josephson junction as a tool for stochastic (probabilistic) determination of physical parameters such as magnetic flux, temperature, and current.

  13. Fluctuations in the hadronization

    International Nuclear Information System (INIS)

    Bozek, P.; Ploszajaczak, M.

    1992-01-01

    The multiscaling in the fluctuations of the multiparticle distributions at small scales is studied. Similarly to the multiscaling effect, recently found in multifractal models, the dependence of the intermittency patterns on the low density cut-off in the cascade is analyzed. The effect changes the scaling behaviour and leads to stronger dependence of the scaled factorial moments on the resolution than the power law. This could be an explanation of the behaviour observed recently in the experimental 3-dimensional data. The multiscaling analysis allows to restore the universality in the processes with different cut-offs and could be used in the analysis of the experimental data. (author) 17 refs., 5 figs

  14. Balancing activity, stability and conductivity of nanoporous core-shell iridium/iridium oxide oxygen evolution catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong-Tae; Lopes, Pietro Papa; Park, Shin-Ae; Lee, A-Yeong; Lim, Jinkyu; Lee, Hyunjoo; Back, Seoin; Jung, Yousung; Danilovic, Nemanja; Stamenkovic, Vojislav; Erlebacher, Jonah; Snyder, Joshua; Markovic, Nenad M.

    2017-11-13

    The selection of oxide materials for catalyzing the Oxygen Evolution Reaction in acid-based electrolyzers must be guided by the proper balance between activity, stability and conductivity – a challenging mission of great importance for delivering affordable and environmentally friendly hydrogen. Here we report that the highly conductive nanoporous architecture of an iridium oxide shell on a metallic iridium core, formed through the fast dealloying of osmium from an Ir25Os75 alloy, exhibits an exceptional balance between oxygen evolution activity and stability as quantified by the Activity-Stability FactorASF. Based on this metric, the nanoporous Ir/IrO2 morphology of dealloyed Ir25Os75 shows a factor of ~30 improvement ASFrelative to conventional Ir-based oxide materials and a ~8 times improvement over dealloyed Ir25Os75 nanoparticles due to optimized stability and conductivity, respectively. We propose that the Activity-Stability FactorASF is the key “metric” for determining the technological relevance of oxide-based anodic water electrolyzer catalysts.

  15. Exercise performance, core temperature, and metabolism after prolonged restricted activity and retraining in dogs

    Science.gov (United States)

    Nazar, K.; Greenleaf, J. E.; Pohoska, E.; Turlejska, E.; Kaciuba-Uscilko, H.; Kozlowski, S.

    1992-01-01

    Physiological effects of restricted activity (RA) and subsequent retraining have been studied. Ten male mongrel dogs performed a submaximal exercise endurance test on a treadmill during kennel control, after 8 weeks of cage confinement and after eight weeks of retraining using the same treadmill protocol 1 h/d for 6 d/week. Data obtained show that RA reduces exercise endurance, the effectiveness of exercise thermoregulation, muscle glycogen stores, and the lipolytic response to exercise and to noradrenaline stimulation.

  16. The dense core vesicle protein IA-2, but not IA-2β, is required for active avoidance learning.

    Science.gov (United States)

    Carmona, G N; Nishimura, T; Schindler, C W; Panlilio, L V; Notkins, A L

    2014-06-06

    The islet-antigens IA-2 and IA-2β are major autoantigens in type-1 diabetes and transmembrane proteins in dense core vesicles (DCV). Recently we showed that deletion of both IA-2 and IA-2β alters the secretion of hormones and neurotransmitters and impairs behavior and learning. The present study was designed to evaluate the contribution to learning of each of these genes by using single knockout (SKO) and double knockout (DKO) mice in an active avoidance test. After 5 days of training, wild-type (WT) mice showed 60-70% active avoidance responses, whereas the DKO mice showed only 10-15% active avoidance responses. The degree of active avoidance responses in the IA-2 SKO mice was similar to that of the DKO mice, but in contrast, the IA-2β SKO mice behaved like WT mice showing 60-70% active avoidance responses. Molecular studies revealed a marked decrease in the phosphorylation of the cAMP response element-binding protein (CREB) and Ca(2+)/calmodulin-dependent protein kinase II (CAMKII) in the striatum and hippocampus of the IA-2 SKO and DKO mice, but not in the IA-2β SKO mice. To evaluate the role of CREB and CAMKII in the SKO and DKO mice, GBR-12909, which selectively blocks the dopamine uptake transporter and increases CREB and CAMKII phosphorylation, was administered. GBR-12909 restored the phosphorylation of CREB and CAMKII and increased active avoidance learning in the DKO and IA-2 SKO to near the normal levels found in the WT and IA-2β SKO mice. We conclude that in the absence of the DCV protein IA-2, active avoidance learning is impaired. Published by Elsevier Ltd.

  17. Systematic logging utilizing a log sheet designed for drill core descriptions. An example in uranium exploration activities

    International Nuclear Information System (INIS)

    Sasao, Eiji; Tsuruta, Tadahiko; Iida, Yoshimasa

    2000-01-01

    We describe the log sheets used during uranium exploration activities for unconformity-related uranium deposits by JNC. The purpose of using the logging sheets is to standardize the objects which all geologists must observe and for data quality assurance. The log sheets are a three-part set describing basement lithology, sandstone lithology and geotechnics. We devised our own log sheets to describe both the sandstone and the underlying basement rock when we started exploration in Athabasca Basin, Canada. We modified the sheets to gain a better understanding of the geological features related to uranium mineralization, and made final improvements to satisfy required quality based on the criteria of descriptive objects and accuracy. Use of the log sheets resulted in effective performance of core logging and improvement in the display of data. (author)

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

    Directory of Open Access Journals (Sweden)

    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. Status and prospects of WWER in-core fuel management activities

    International Nuclear Information System (INIS)

    Novikov, A.N.; Pavlov, V.I.; Pavlovichev, A.M.; Proselkov, V.N.; Saprykin, V.V.

    1994-01-01

    A short review is given of recent extensive calculational and experimental studies carried out in Russia and Bulgaria for WWER fuel cycle modernization. The main activities performed at Kola NPP, Novovoronezh NPP, Kozloduy NPP and Balakovo NPP are outlined. Based on experience gained, the following improvements in the fuel cycle have been introduced: 1) increased fuel burnup; 2) reduced natural uranium consumption and decreased amount of separation work per energy output unit; 3) increased efficiency of the reactor emergency protection; 4) reduced fast neutron flux onto the reactor vessel. The main characteristics of modernized fuel cycles of WWER-440 and WWER-1000 are presented. 4 tabs., 3 figs., 14 refs

  20. Status and prospects of WWER in-core fuel management activities

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, A N; Pavlov, V I; Pavlovichev, A M; Proselkov, V N; Saprykin, V V [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation)

    1994-12-31

    A short review is given of recent extensive calculational and experimental studies carried out in Russia and Bulgaria for WWER fuel cycle modernization. The main activities performed at Kola NPP, Novovoronezh NPP, Kozloduy NPP and Balakovo NPP are outlined. Based on experience gained, the following improvements in the fuel cycle have been introduced: (1) increased fuel burnup; (2) reduced natural uranium consumption and decreased amount of separation work per energy output unit; (3) increased efficiency of the reactor emergency protection; (4) reduced fast neutron flux onto the reactor vessel. The main characteristics of modernized fuel cycles of WWER-440 and WWER-1000 are presented. 4 tabs., 3 figs., 14 refs.

  1. Investigation of radial propagation of electrostatic fluctuations in the IR-T1 tokamak plasma edge

    Energy Technology Data Exchange (ETDEWEB)

    Shariatzadeh, R; Ghoranneviss, M; Salem, M K [Plasma Physics Research Center, Science and Research Branch, Islamic Azad University (IAU), PO Box 14665-678, Tehran (Iran, Islamic Republic of); Emami, M, E-mail: rezashariatzadeh@gmail.com [Laser and Optics Research School, NSTRI, AEOI, PO Box 14155-1339, Tehran (Iran, Islamic Republic of)

    2011-01-15

    The radial propagation of electrostatic fluctuation is considered extremely important for understanding cross-field anomalous transport. In this paper, two arrays of Langmuir probes are used to analyze electrostatic fluctuations in the edge of IR-T1 tokamak plasma in both the radial and the poloidal directions. The propagation characteristics of the floating potential fluctuations are analyzed by the two-point correlation technique. The wavenumber spectrum shows that there is a net radially outward propagation of turbulent fluctuations in the edge and scrape-off layer (SOL) regions. Hence, edge turbulence presumably originates from core fluctuations.

  2. Scrape-off layer-induced beam density fluctuations and their effect on beam emission spectroscopy

    Science.gov (United States)

    Moulton, D.; Marandet, Y.; Tamain, P.; Dif-Pradalier, G.

    2015-07-01

    A statistical model is presented to calculate the magnitude of beam density fluctuations generated by a turbulent scrape-off layer (SOL). It is shown that the SOL can induce neutral beam density fluctuations of a similar magnitude to the plasma density fluctuations in the core, potentially corrupting beam emission spectroscopy measurements. The degree of corruption is quantified by combining simulations of beam and plasma density fluctuations inside a simulated measurement window. A change in pitch angle from the separatrix to the measurement window is found to reduce the effect of beam fluctuations, whose largest effect is to significantly reduce the measured correlation time.

  3. Investigation of radial propagation of electrostatic fluctuations in the IR-T1 tokamak plasma edge

    International Nuclear Information System (INIS)

    Shariatzadeh, R; Ghoranneviss, M; Salem, M K; Emami, M

    2011-01-01

    The radial propagation of electrostatic fluctuation is considered extremely important for understanding cross-field anomalous transport. In this paper, two arrays of Langmuir probes are used to analyze electrostatic fluctuations in the edge of IR-T1 tokamak plasma in both the radial and the poloidal directions. The propagation characteristics of the floating potential fluctuations are analyzed by the two-point correlation technique. The wavenumber spectrum shows that there is a net radially outward propagation of turbulent fluctuations in the edge and scrape-off layer (SOL) regions. Hence, edge turbulence presumably originates from core fluctuations.

  4. Plastics in the Ocean: Engaging Students in Core Competencies Through Issues-Based Activities in the Science Classroom.

    Science.gov (United States)

    Fergusson-Kolmes, L. A.

    2016-02-01

    Plastic pollution in the ocean is a critical issue. The high profile of this issue in the popular media makes it an opportune vehicle for promoting deeper understanding of the topic while also advancing student learning in the core competency areas identified in the NSF's Vision and Change document: integration of the process of science, quantitative reasoning, modeling and simulation, and an understanding of the relationship between science and society. This is a challenging task in an introductory non-majors class where the students may have very limited math skills and no prior science background. In this case activities are described that ask students to use an understanding of density to make predictions and test them as they consider the fate of different kinds of plastics in the marine environment. A comparison of the results from different sampling regimes introduces students to the difficulties of carrying out scientific investigations in the complex marine environment as well as building quantitative literacy skills. Activities that call on students to make connections between global issues of plastic pollution and personal actions include extraction of microplastic from personal care products, inventories of local plastic-recycling options and estimations of contributions to the waste stream on an individual level. This combination of hands-on-activities in an accessible context serves to help students appreciate the immediacy of the threat of plastic pollution and calls them to reflect on possible solutions.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Comparison of the electrical activity of trunk core muscles and knee muscles in subjects with and without patellofemoral pain syndrome during gait

    Directory of Open Access Journals (Sweden)

    Raheleh Dorosti

    2017-10-01

    Conclusion: It seems that electromyographic activities of some of core muscles in patients with patellofemoral pain syndrome in comparison with healthy subjects are different. However, there was no differences in electromyographic activities in some of the muscles around the knee between patients and healthy subjects.

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

    Science.gov (United States)

    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., H 2 O 2 , substrate, and oxidase) due to the aperture limitation of the ZIF-8 shell. H 2 O 2 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 H 2 O 2 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. TRACING MULTIPLE GENERATIONS OF ACTIVE GALACTIC NUCLEUS FEEDBACK IN THE CORE OF ABELL 262

    International Nuclear Information System (INIS)

    Clarke, T. E.; Kassim, N. E.; Blanton, E. L.; Anderson, L. D.; Douglass, E. M.; Sarazin, C. L.; Gopal-Krishna

    2009-01-01

    We present new radio and X-ray observations of Abell 262. The X-ray residual image provides the first evidence of an X-ray tunnel in this system while the radio data reveal that the central radio source is more than three times larger than previously known. We find that the well-known cluster-center S-shaped radio source B2 0149+35 is surrounded by extended emission to the east and southwest. The south-western extension is cospatial with the X-ray tunnel seen in our new Chandra images while the eastern extension shows three clumps of emission with the innermost coincident with a faint X-ray cavity. The outer two eastern radio extensions are coincident with a newly detected X-ray depression. We use the projected separation of the emission regions to estimate a lower limit of τ rep = 28 Myr to the outburst repetition timescale of the central active galactic nucleus (AGN). The total energy input into the cluster over multiple outburst episodes is estimated to be 2.2 x 10 58 erg, more than an order of magnitude larger than previously thought. The total AGN energy output determined from our new observations shows that the source should be capable of offsetting radiative cooling over several outburst episodes.

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

    Directory of Open Access Journals (Sweden)

    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. HOT PLASMA FROM SOLAR ACTIVE-REGION CORES: CONSTRAINTS FROM THE HINODE X-RAY TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Schmelz, J. T. [USRA, 7178 Columbia Gateway Drive, Columbia, MD 21046 (United States); Christian, G. M.; Matheny, P. O., E-mail: jschmelz@usra.edu [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

    2016-12-20

    Mechanisms invoked to heat the solar corona to millions of degrees kelvin involve either magnetic waves or magnetic reconnections. Turbulence in the convection zone produces MHD waves, which travel upward and dissipate. Photospheric motions continuously build up magnetic energy, which is released through magnetic reconnection. In this paper, we concentrate on hot non-flaring plasma with temperatures of 5 MK <  T  < 10 MK because it is one of the few observables for which wave and reconnection models make different predictions. Wave models predict no (or little) hot plasma, whereas reconnection models predict it, although in amounts that are challenging to detect with current instrumentation. We used data from the X-ray Telescope (XRT) and the Atmospheric Imaging Assembly (AIA). We requested a special XRT observing sequence, which cycled through the thickest XRT filter several times per hour so we could average these images and improve the signal-to-noise. We did differential emission measure (DEM) analysis using the time-averaged thick-filter data as well as all available channels from both the XRT and AIA for regions observed on 2014 December 11. Whereas our earlier work was only able to determine that plasma with a temperature greater than 5 MK was present , we are now able to find a well-constrained DEM distribution. We have therefore added a strong observational constraint that must be explained by any viable coronal heating model. Comparing state-of-the-art wave and reconnection model predictions, we can conclude that reconnection is heating the hot plasma in these active regions.

  11. Fluctuation Relations for Currents

    Science.gov (United States)

    Sinitsyn, Nikolai; Akimov, Alexei; Chernyak, Vladimir; Chertkov, Michael

    2011-03-01

    We consider a non-equilibrium statistical system on a graph or a network. Identical particles are injected, interact with each other, traverse, and leave the graph in a stochastic manner described in terms of Poisson rates, possibly strongly dependent on time and instantaneous occupation numbers at the nodes of the graph. We show that the system demonstrates a profound statistical symmetry, leading to new Fluctuation Relations that originate from the supersymmetry and the principle of the geometric universality of currents rather than from the relations between probabilities of forward and reverse trajectories. NSF/ECCS-0925618, NSF/CHE-0808910 and DOE at LANL under Contract No. DE-AC52-06NA25396.

  12. Impact of magnetic shear modification on confinement and turbulent fluctuations in LHD plasmas

    International Nuclear Information System (INIS)

    Fukuda, T.; Tamura, N.; Ida, K.

    2008-10-01

    For the comprehensive understandings of transport phenomena in toroidal confinement systems and improvement of the predictive capability of burning plasmas in ITER, the impact of magnetic shear has been extensively investigated in the Large Helical Device (LHD) for comparison with tokamaks. Consequently, it was heuristically documented that the pronounced effect of magnetic shear, which has been hitherto considered to be ubiquitous and strongly impacts the core transport in the tokamak experiments, is not quite obvious. Namely, the kinetic profiles respond little under extensive modification of the magnetic shear in the core, although the local transport analysis indicates the sign of improvement in confinement transiently when the magnetic shear is reduced. It was thereby concluded that the magnetic shear in the core strongly influences the MHD activity, but it may only be one of the necessary conditions for the transport reduction, and some other crucial knobs, such as the density gradient or T e /T i ratio, would have to be simultaneously controlled. The low wavenumber turbulence seems to be suppressed under the weak shear, and the turbulent fluctuation intensity behaves in a consistent manner as a whole, following the conventional paradigm accumulated in the negative shear experiments in tokamaks. However, vigorous dynamics of turbulent fluctuations have occasionally been observed under the magnetic shear modification, which respond in much faster time scale than the characteristic time scale for either the magnetic diffusion or the profile evolution. (author)

  13. The N terminus of cGAS de-oligomerizes the cGAS:DNA complex and lifts the DNA size restriction of core-cGAS activity.

    Science.gov (United States)

    Lee, Arum; Park, Eun-Byeol; Lee, Janghyun; Choi, Byong-Seok; Kang, Suk-Jo

    2017-03-01

    Cyclic GMP-AMP synthase (cGAS) is a DNA-sensing enzyme in the innate immune system. Recent studies using core-cGAS lacking the N terminus investigated the mechanism for binding of double-stranded (ds) DNA and synthesis of 2',3'-cyclic GMP-AMP (cGAMP), a secondary messenger that ultimately induces type I interferons. However, the function of the N terminus of cGAS remains largely unknown. Here, we found that the N terminus enhanced the activity of core-cGAS in vivo. Importantly, the catalytic activity of core-cGAS decreased as the length of double-stranded DNA (dsDNA) increased, but the diminished activity was restored by addition of the N terminus. Furthermore, the N terminus de-oligomerized the 2 : 2 complex of core-cGAS and dsDNA into a 1 : 1 complex, suggesting that the N terminus enhanced the activity of core-cGAS by facilitating formation of a monomeric complex of cGAS and DNA. © 2017 Federation of European Biochemical Societies.

  14. Current status of studies on temperature fluctuation phenomena in LMFRs

    International Nuclear Information System (INIS)

    Ohshima, H.; Muramatsu, T.; Kobayashi, J.; Yamaguchi, A.

    1994-01-01

    This paper describes the current status of studies being performed in PNC on temperature fluctuation phenomena occurring in fast reactors. The studies concentrate on four problems: thermal stratification, thermal striping, core-plenum interaction and free surface sloshing. Both experimental and analytical approaches to reveal these phenomena and to establish design and safety evaluation methods are presented together with future works. (author)

  15. Fluctuations in email size

    Science.gov (United States)

    Matsubara, Yoshitsugu; Musashi, Yasuo

    2017-12-01

    The purpose of this study is to explain fluctuations in email size. We have previously investigated the long-term correlations between email send requests and data flow in the system log of the primary staff email server at a university campus, finding that email size frequency follows a power-law distribution with two inflection points, and that the power-law property weakens the correlation of the data flow. However, the mechanism underlying this fluctuation is not completely understood. We collected new log data from both staff and students over six academic years and analyzed the frequency distribution thereof, focusing on the type of content contained in the emails. Furthermore, we obtained permission to collect "Content-Type" log data from the email headers. We therefore collected the staff log data from May 1, 2015 to July 31, 2015, creating two subdistributions. In this paper, we propose a model to explain these subdistributions, which follow log-normal-like distributions. In the log-normal-like model, email senders -consciously or unconsciously- regulate the size of new email sentences according to a normal distribution. The fitting of the model is acceptable for these subdistributions, and the model demonstrates power-law properties for large email sizes. An analysis of the length of new email sentences would be required for further discussion of our model; however, to protect user privacy at the participating organization, we left this analysis for future work. This study provides new knowledge on the properties of email sizes, and our model is expected to contribute to the decision on whether to establish upper size limits in the design of email services.

  16. Torsional Oscillations of the Earths's Core

    Science.gov (United States)

    Hide, Raymond; Boggs, Dale H.; Dickey, Jean O.

    1997-01-01

    Torsional oscillations of the Earth's liquid metallic outer core are investigated by diving the core into twenty imaginary e1qui-volume annuli coaxial with the axis of ratation of the Earth and determining temproal fluctuations in the axial component of angular memonetum of each annulus under the assumption of iso-rotation on cylindrical surfaces.

  17. Activities of working party on 'Subcritical core of accelerator-driven system' under the research committee on reactor physics of AESJ and JAERI

    International Nuclear Information System (INIS)

    Iwasaki, T.; Tsujimoto, K.; Nishihara, K.; Kitamura, Y.

    2004-01-01

    The Research Committee on Reactor Physics under the Atomic Energy Society of Japan and the Japan Atomic Energy Research Inst. organized the working party (ADS-WP) on S ubcritical Core of Accelerator-Driven System . The ADS-WP investigated reactor physics of subcriticality from the viewpoint of the accelerator driven system (ADS) since subcriticality has been almost studied from the viewpoint of critical safety. The working party was set in July 2001 and it worked for two years. The activities of the ADS-WP are (Work-I) theory of subcriticality, (Work-II) benchmark of subcritical core, (Work-III) setting of subcriticality level of ADS and (Work-JAO monitoring of subcriticality. These activities clarified about the important issues related to the subcriticality or the subcritical core from the wide ranges of theory, analysis, calculation, design and monitoring for ADS. The activities were already summarized and the report will be published in March 2004. (authors)

  18. Fluctuating Thermodynamics for Biological Processes

    Science.gov (United States)

    Ham, Sihyun

    Because biomolecular processes are largely under thermodynamic control, dynamic extension of thermodynamics is necessary to uncover the mechanisms and driving factors of fluctuating processes. The fluctuating thermodynamics technology presented in this talk offers a practical means for the thermodynamic characterization of conformational dynamics in biomolecules. The use of fluctuating thermodynamics has the potential to provide a comprehensive picture of fluctuating phenomena in diverse biological processes. Through the application of fluctuating thermodynamics, we provide a thermodynamic perspective on the misfolding and aggregation of the various proteins associated with human diseases. In this talk, I will present the detailed concepts and applications of the fluctuating thermodynamics technology for elucidating biological processes. This work was supported by Samsung Science and Technology Foundation under Project Number SSTF-BA1401-13.

  19. Concentration fluctuations in gas releases by industrial accidents

    DEFF Research Database (Denmark)

    Nielsen, M.; Chatwin, P.C.; Ejsing Jørgensen, Hans

    2002-01-01

    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 statisticalanalyses and surface-layer scaling. The statistical...... and the probability distribution for the plume centreline. The distance-neighbour function generalizedfor 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...... 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 thesemoments is universal with a gaussian core and exponential tails. The instantaneous plume width...

  20. Statistical fluctuations of the number of neutrons in a pile

    International Nuclear Information System (INIS)

    Raievski, V.

    1958-01-01

    The theory of the statistical fluctuations in a pile is extended to the space dependent case, and gives the fluctuations of the number of neutrons in a cell of the core or reflector of the pile. This number changes through elementary processes occurring at random, which are, capture, source, fission and scattering. Of all these processes, fission is the only one which changes more than one neutron at a time and so is responsible of the deviation of the fluctuations from a Poisson law. The importance of this deviation depends on the dimensions of the cell compared to the slowing down length. When the dimensions are small, the fluctuations close to a Poisson law. (author) [fr

  1. Switchable transport strategy to deposit active Fe/Fe3C cores into hollow microporous carbons for efficient chromium removal.

    Science.gov (United States)

    Liu, Dong-Hai; Guo, Yue; Zhang, Lu-Hua; Li, Wen-Cui; Sun, Tao; Lu, An-Hui

    2013-11-25

    Magnetic hollow structures with microporous shell and highly dispersed active cores (Fe/Fe3 C nanoparticles) are rationally designed and fabricated by solution-phase switchable transport of active iron species combined with a solid-state thermolysis technique, thus allowing selective encapsulation of functional Fe/Fe3 C nanoparticles in the interior cavity. These engineered functional materials show high loading (≈54 wt%) of Fe, excellent chromium removal capability (100 mg g(-1)), fast adsorption rate (8766 mL mg(-1) h(-1)), and easy magnetic separation property (63.25 emu g(-1)). During the adsorption process, the internal highly dispersed Fe/Fe3 C nanoparticles supply a driving force for facilitating Cr(VI) diffusion inward, thus improving the adsorption rate and the adsorption capacity. At the same time, the external microporous carbon shell can also efficiently trap guest Cr(VI) ions and protect Fe/Fe3 C nanoparticles from corrosion and subsequent leaching problems. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Treatment of fluctuations of startup rates for core subcriticality monitoring

    International Nuclear Information System (INIS)

    Mol, Antonio Carlos de Abreu; Martinez, Aquilino Senra

    1996-01-01

    In this paper it is presented a method to eliminate the variations in the source and intermediate range count rate, which are used for the on-line and real time monitoring of the critical safety function Subcriticality. The method may be applied to a safety parameters display system, because it is very simple and precise, which it will not affect the real time requirements of such systems. Variations in the count range could cause a temporary positive startup rate, that could lead to incorrect addressing of function restoration guideline. (author)

  3. Gyro-Landau fluid model of tokamak core fluctuations

    International Nuclear Information System (INIS)

    Leboeuf, J.N.; Carreras, B.A.; Dominguez, N.; Hedrick, C.L.; Sidikman, K.L.; Lynch, V.E.; Drake, J.B.; Walker, D.W.

    1992-01-01

    Dissipative trapped electron modes (DTEM) may be one of the causes of deterioration of confinement in tokamak and stellatator plasmas. We have implemented a fluid model to study DTEM turbulence in slab geometry. The electron dynamics include in addition to the adiabatic part, a non-adiabatic piece modeled with an i-delta-type response. The ion dynamics include Landau damping and FLR corrections through Landau fluid approximate techniques and Pade approximants for Γ 0 (b)=I 0 (b)e -b . The model follows from the gyrokinetic equation. Evolution equations, which closely resemble those used in standard reduced MHD, are presented since these are better suited to non-linear calculations. The numerical results of radially resolved calculations will be discussed. A recently developed hybrid model, which consists of a gyrokinetic implementation for the ions using particles and the same description for the electron dynamics as in the fluid model, will also be presented

  4. Big Bang or vacuum fluctuation

    International Nuclear Information System (INIS)

    Zel'dovich, Ya.B.

    1980-01-01

    Some general properties of vacuum fluctuations in quantum field theory are described. The connection between the ''energy dominance'' of the energy density of vacuum fluctuations in curved space-time and the presence of singularity is discussed. It is pointed out that a de-Sitter space-time (with the energy density of the vacuum fluctuations in the Einstein equations) that matches the expanding Friedman solution may describe the history of the Universe before the Big Bang. (P.L.)

  5. Thermodynamic theory of equilibrium fluctuations

    International Nuclear Information System (INIS)

    Mishin, Y.

    2015-01-01

    The postulational basis of classical thermodynamics has been expanded to incorporate equilibrium fluctuations. The main additional elements of the proposed thermodynamic theory are the concept of quasi-equilibrium states, a definition of non-equilibrium entropy, a fundamental equation of state in the entropy representation, and a fluctuation postulate describing the probability distribution of macroscopic parameters of an isolated system. Although these elements introduce a statistical component that does not exist in classical thermodynamics, the logical structure of the theory is different from that of statistical mechanics and represents an expanded version of thermodynamics. Based on this theory, we present a regular procedure for calculations of equilibrium fluctuations of extensive parameters, intensive parameters and densities in systems with any number of fluctuating parameters. The proposed fluctuation formalism is demonstrated by four applications: (1) derivation of the complete set of fluctuation relations for a simple fluid in three different ensembles; (2) fluctuations in finite-reservoir systems interpolating between the canonical and micro-canonical ensembles; (3) derivation of fluctuation relations for excess properties of grain boundaries in binary solid solutions, and (4) derivation of the grain boundary width distribution for pre-melted grain boundaries in alloys. The last two applications offer an efficient fluctuation-based approach to calculations of interface excess properties and extraction of the disjoining potential in pre-melted grain boundaries. Possible future extensions of the theory are outlined.

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

    Directory of Open Access Journals (Sweden)

    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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sojka, Bartlomiej [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Liskova, Aurelia; Kuricova, Miroslava [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia); Banski, Mateusz; Misiewicz, Jan [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Dusinska, Maria [Norwegian Institute for Air Research, Health Effects Laboratory, Department of Environmental Chemistry (Norway); Horvathova, Mira; Ilavska, Silvia; Szabova, Michaela [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia); Rollerova, Eva [Slovak Medical University, Faculty of Public Health, Department of Toxicology (Slovakia); Podhorodecki, Artur, E-mail: artur.p.podhorodecki@pwr.edu.pl [Wroclaw University of Science and Technology, Department of Experimental Physics (Poland); Tulinska, Jana, E-mail: jana.tulinska@szu.sk [Slovak Medical University, Medical Faculty, Department of Immunology and Immunotoxicology (Slovakia)

    2017-02-15

    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.

  9. Magnetic fluctuations associated with density fluctuations in the tokamak edge

    International Nuclear Information System (INIS)

    Kim, Y.J.; Gentle, K.W.; Ritz, C.P.; Rhodes, T.L.; Bengtson, R.D.

    1989-01-01

    Electrostatic density and potential fluctuations occurring with high amplitude near the edge of a tokamak are correlated with components of the fluctuating magnetic field measured outside the limiter radius. It has been established that this turbulence is associated with fluctuations in current as well as density and potential. The correlation extends for substantial toroidal distances, but only if the probes are displaced approximately along field lines, consistent with the short coherence lengths poloidally but long coherence lengths parallel to the field which are characteristic for this turbulence. Furthermore, the correlation can be found only with density fluctuations measured inside the limiter radius; density fluctuations behind the limiter have no detectable magnetic concomitant for the toroidally spaced probes used here. (author). Letter-to-the-editor. 12 refs, 3 figs

  10. Statistical fluctuations of the number of neutrons in a pile; Fluctuations statistiques du nombre de neutrons dans une pile

    Energy Technology Data Exchange (ETDEWEB)

    Raievski, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The theory of the statistical fluctuations in a pile is extended to the space dependent case, and gives the fluctuations of the number of neutrons in a cell of the core or reflector of the pile. This number changes through elementary processes occurring at random, which are, capture, source, fission and scattering. Of all these processes, fission is the only one which changes more than one neutron at a time and so is responsible of the deviation of the fluctuations from a Poisson law. The importance of this deviation depends on the dimensions of the cell compared to the slowing down length. When the dimensions are small, the fluctuations close to a Poisson law. (author) [French] La theorie des fluctuations statistiques est etendue au cas local et donne les fluctuations du nombre de neutrons dans une cellule situee dans le coeur ou le reflecteur de la pile. Ce nombre evolue au cours du temps sous l'influence de phenomenes aleatoires qui sont la capture, la diffusion, les sources et les neutrons secondaires de fission. L'emission simultanee de plusieurs neutrons distingue ce phenomene des precedents qui n'affectent qu'un neutron individuellement. L'importance de ce phenomene sur la loi de fluctuation depend des dimensions de la cellule par rapport a la longueur de ralentissement. Quand ces dimensions sont petites, le caractere particulier de ce phenomene disparait. (auteur)

  11. Holocene eruptive activity of Yufu-Tsurumi volcano group found from piston cores in Beppu bay, Central Kyushu; Beppuwan core kara mita Yufu Tsurumi kazangun ni okeru kanshinsei no funka katsudo

    Energy Technology Data Exchange (ETDEWEB)

    Umeda, K. [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan); Kusanagi, M. [Kobe University, Kobe (Japan); Furusawa, A. [Dia Consultants Co. Ltd., Nagoya (Japan); Ui, T. [Hokkaido University, Sapporo (Japan)

    1996-08-01

    With an objective to identify the Holocene eruptive activity of the Yufu-Tsurumi volcano group, analysis was made on the volcanic ash, Yufu-dake 1 (a product of the latest eruptive activity). The analysis used piston core samples collected in Beppu Bay. Volcanic ash deposited in lakes and inner bays are not subjected to erosion effect, hence remain in better condition than on-land deposits. A volcanic ash bed characteristically containing micro-crystal contained glass has existed, and so has a volcanic ash bed characteristically containing volcanic foam glass and polyhedral glass. The volcanic ash bed characteristically containing micro-crystal contained glass was found comparable with the Yufu-dake 1 volcanic ash bed originated in the Yufu-Tsurumi volcanic group, as proven from the stratigraphy, rock statement and refraction of the volcanic glass. As a result of performing a {sup 14}C age measurement on seashells in the core samples by using an accelerator mass analysis method, it was found that the eruption age of the Yufu-dake 1 volcanic ash dates back about 2,500 years ago. Core samples collected from lakes and inner bays contain much carbonic material used in the {sup 14}C age measurement. Therefore, investigation on volcanic ash deposited on ocean bottoms is effective. 25 refs., 7 figs., 3 tabs.

  12. 75 FR 8239 - Federal Home Loan Bank Housing Associates, Core Mission Activities and Standby Letters of Credit

    Science.gov (United States)

    2010-02-24

    ... written appeal to FHFA that includes the Bank's decision resolution and a statement of the basis for the... Parts 1264, 1265 and 1269 RIN 2590-AA33 Federal Home Loan Bank Housing Associates, Core Mission... regulations address, respectively, Federal Home Loan Bank (Bank) housing associates, the Banks' core mission...

  13. Galvanic replacement-free deposition of Au on Ag for core-shell nanocubes with enhanced chemical stability and SERS activity.

    Science.gov (United States)

    Yang, Yin; Liu, Jingyue; Fu, Zheng-Wen; Qin, Dong

    2014-06-11

    We report a robust synthesis of Ag@Au core-shell nanocubes by directly depositing Au atoms on the surfaces of Ag nanocubes as conformal, ultrathin shells. Our success relies on the introduction of a strong reducing agent to compete with and thereby block the galvanic replacement between Ag and HAuCl4. An ultrathin Au shell of 0.6 nm thick was able to protect the Ag in the core in an oxidative environment. Significantly, the core-shell nanocubes exhibited surface plasmonic properties essentially identical to those of the original Ag nanocubes, while the SERS activity showed a 5.4-fold further enhancement owing to an improvement in chemical enhancement. The combination of excellent SERS activity and chemical stability may enable a variety of new applications.

  14. Charge Fluctuations in Nanoscale Capacitors

    NARCIS (Netherlands)

    Limmer, D.T.; Merlet, C.; Salanne, M.; Chandler, D.; Madden, P.A.; van Roij, R.H.H.G.; Rotenberg, B.

    2013-01-01

    The fluctuations of the charge on an electrode contain information on the microscopic correlations within the adjacent fluid and their effect on the electronic properties of the interface. We investigate these fluctuations using molecular dynamics simulations in a constant-potential ensemble with

  15. Fluctuating attention in Parkinson's disease

    DEFF Research Database (Denmark)

    Starrfelt, Randi; Aarsland, Dag; Janvin, Carmen

    2001-01-01

    Lewy body dementia (DLB), which share many clinical and pathological features with Parkinson’s disease (PD), is charac- terised by marked fluctuations in cognition and consciousness. Fluctuating cognition has not been formally studied in PD, although some studies indicate that PD patients show...

  16. Evidence of Influence of Human Activities and Volcanic Eruptions on Environmental Perchlorate from a 300-Year Greenland Ice Core Record.

    Science.gov (United States)

    Cole-Dai, Jihong; Peterson, Kari Marie; Kennedy, Joshua Andrew; Cox, Thomas S; Ferris, David G

    2018-06-26

    A 300-year (1700-2007) chronological record of environmental perchlorate, reconstructed from high-resolution analysis of a central Greenland ice core, shows that perchlorate levels in the post-1980 atmosphere were two-to-three times those of the pre-1980 environment. While this confirms recent reports of increased perchlorate in Arctic snow since 1980 compared with the levels for the prior decades (1930-1980), the longer Greenland record demonstrates that the Industrial Revolution and other human activities, which emitted large quantities of pollutants and contaminants, did not significantly impact environmental perchlorate, as perchlorate levels remained stable throughout the eighteenth, nineteenth, and much of the twentieth centuries. The increased levels since 1980 likely result from enhanced atmospheric perchlorate production, rather than from direct release from perchlorate manufacturing and applications. The enhancement is probably influenced by the emission of organic chlorine compounds in the last several decades. Prior to 1980, no significant long-term temporal trends in perchlorate concentration are observed. Brief (a few years) high concentration episodes appear frequently over an apparently stable and low background (~1 ng kg‒1). Several such episodes coincide in time with large explosive volcanic eruptions including the 1912 Novarupta/Katmai eruption in Alaska. It appears that atmospheric perchlorate production is impacted by large eruptions in both high and low latitudes, but not by small eruptions and non-explosive degassing.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. INFERENCE OF HEATING PROPERTIES FROM “HOT” NON-FLARING PLASMAS IN ACTIVE REGION CORES. II. NANOFLARE TRAINS

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, W. T.; Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77251-1892 (United States); Cargill, P. J., E-mail: will.t.barnes@rice.edu, E-mail: stephen.bradshaw@rice.edu, E-mail: p.cargill@imperial.ac.uk [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)

    2016-12-20

    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 (EM(T)) peaks at T = T{sub m} , we find that EM(T{sub m}) is independent of details of the nanoflare train, and EM(T) above and below T{sub m} reflects different aspects of the heating. Below T{sub m} , the main influence is the relationship of the waiting time between successive nanoflares to the nanoflare energy. Above T{sub m}, power-law nanoflare distributions lead to an extensive plasma population not present in a mono-energetic train. Furthermore, in some cases, characteristic features are present in EM(T). Such details may be detectable given adequate spectral resolution and a good knowledge of the relevant atomic physics. In the absence of such resolution we propose some metrics that can be used to infer the presence of “hot” plasma.

  19. Hydraulic and acoustic properties of the active Alpine Fault, New Zealand: Laboratory measurements on DFDP-1 drill core

    Science.gov (United States)

    Carpenter, B. M.; Kitajima, H.; Sutherland, R.; Townend, J.; Toy, V. G.; Saffer, D. M.

    2014-03-01

    We report on laboratory measurements of permeability and elastic wavespeed for a suite of samples obtained by drilling across the active Alpine Fault on the South Island of New Zealand, as part of the first phase of the Deep Fault Drilling Project (DFDP-1). We find that clay-rich cataclasite and principal slip zone (PSZ) samples exhibit low permeabilities (⩽10-18 m), and that the permeability of hanging-wall cataclasites increases (from c. 10-18 m to 10-15 m) with distance from the fault. Additionally, the PSZ exhibits a markedly lower P-wave velocity and Young's modulus relative to the wall rocks. Our laboratory data are in good agreement with in situ wireline logging measurements and are consistent with the identification of an alteration zone surrounding the PSZ defined by observations of core samples. The properties of this zone and the low permeability of the PSZ likely govern transient hydrologic processes during earthquake slip, including thermal pressurization and dilatancy strengthening.

  20. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... applications, and places emphasis on the development of polarization maintaining (PM) HC-PCF. The polarization cross-coupling characteristics of PM HC-PCF are very different from those of conventional PM fibers. The former fibers have the advantage of suffering far less from stress-field fluctuations...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  2. Nonequilibrium fluctuations in a resistor.

    Science.gov (United States)

    Garnier, N; Ciliberto, S

    2005-06-01

    In small systems where relevant energies are comparable to thermal agitation, fluctuations are of the order of average values. In systems in thermodynamical equilibrium, the variance of these fluctuations can be related to the dissipation constant in the system, exploiting the fluctuation-dissipation theorem. In nonequilibrium steady systems, fluctuations theorems (FT) additionally describe symmetry properties of the probability density functions (PDFs) of the fluctuations of injected and dissipated energies. We experimentally probe a model system: an electrical dipole driven out of equilibrium by a small constant current I, and show that FT are experimentally accessible and valid. Furthermore, we stress that FT can be used to measure the dissipated power P = R I2 in the system by just studying the PDFs' symmetries.

  3. Inverse scattering problem in turbulent magnetic fluctuations

    Directory of Open Access Journals (Sweden)

    R. A. Treumann

    2016-08-01

    Full Text Available 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

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    International Nuclear Information System (INIS)

    Wasserman, Julio Cesar; Figueira, Andre Luiz; Kelecom, Alphonse

    2002-01-01

    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 12 n cm -2 s -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)

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Quantum fluctuations from thermal fluctuations in Jacobson formalism

    Energy Technology Data Exchange (ETDEWEB)

    Faizal, Mir [University of British Columbia-Okanagan, Irving K. Barber School of Arts and Sciences, Kelowna, BC (Canada); University of Lethbridge, Department of Physics and Astronomy, Lethbridge, AB (Canada); Ashour, Amani; Alcheikh, Mohammad [Damascus University, Mathematics Department, Faculty of Science, Damascus (Syrian Arab Republic); Alasfar, Lina [Universite Clermont Auvergne, Laboratoire de Physique Corpusculaire de Clermont-Ferrand, Aubiere (France); Alsaleh, Salwa; Mahroussah, Ahmed [King Saud University, Department of Physics and Astronomy, Riyadh (Saudi Arabia)

    2017-09-15

    In the Jacobson formalism general relativity is obtained from thermodynamics. This is done by using the Bekenstein-Hawking entropy-area relation. However, as a black hole gets smaller, its temperature will increase. This will cause the thermal fluctuations to also increase, and these will in turn correct the Bekenstein-Hawking entropy-area relation. Furthermore, with the reduction in the size of the black hole, quantum effects will also start to dominate. Just as the general relativity can be obtained from thermodynamics in the Jacobson formalism, we propose that the quantum fluctuations to the geometry can be obtained from thermal fluctuations. (orig.)

  8. Protection against β-amyloid neurotoxicity by a non-toxic endogenous N-terminal β-amyloid fragment and its active hexapeptide core sequence.

    Science.gov (United States)

    Forest, Kelly H; Alfulaij, Naghum; Arora, Komal; Taketa, Ruth; Sherrin, Tessi; Todorovic, Cedomir; Lawrence, James L M; Yoshikawa, Gene T; Ng, Ho-Leung; Hruby, Victor J; Nichols, Robert A

    2018-01-01

    High levels (μM) of beta amyloid (Aβ) oligomers are known to trigger neurotoxic effects, leading to synaptic impairment, behavioral deficits, and apoptotic cell death. The hydrophobic C-terminal domain of Aβ, together with sequences critical for oligomer formation, is essential for this neurotoxicity. However, Aβ at low levels (pM-nM) has been shown to function as a positive neuromodulator and this activity resides in the hydrophilic N-terminal domain of Aβ. An N-terminal Aβ fragment (1-15/16), found in cerebrospinal fluid, was also shown to be a highly active neuromodulator and to reverse Aβ-induced impairments of long-term potentiation. Here, we show the impact of this N-terminal Aβ fragment and a shorter hexapeptide core sequence in the Aβ fragment (Aβcore: 10-15) to protect or reverse Aβ-induced neuronal toxicity, fear memory deficits and apoptotic death. The neuroprotective effects of the N-terminal Aβ fragment and Aβcore on Aβ-induced changes in mitochondrial function, oxidative stress, and apoptotic neuronal death were demonstrated via mitochondrial membrane potential, live reactive oxygen species, DNA fragmentation and cell survival assays using a model neuroblastoma cell line (differentiated NG108-15) and mouse hippocampal neuron cultures. The protective action of the N-terminal Aβ fragment and Aβcore against spatial memory processing deficits in amyloid precursor protein/PSEN1 (5XFAD) mice was demonstrated in contextual fear conditioning. Stabilized derivatives of the N-terminal Aβcore were also shown to be fully protective against Aβ-triggered oxidative stress. Together, these findings indicate an endogenous neuroprotective role for the N-terminal Aβ fragment, while active stabilized N-terminal Aβcore derivatives offer the potential for therapeutic application. © 2017 International Society for Neurochemistry.

  9. Facile in situ synthesis of wurtzite ZnS/ZnO core/shell heterostructure with highly efficient visible-light photocatalytic activity and photostability

    Science.gov (United States)

    Xiao, Jian-Hua; Huang, Wei-Qing; Hu, Yong-sheng; Zeng, Fan; Huang, Qin-Yi; Zhou, Bing-Xin; Pan, Anlian; Li, Kai; Huang, Gui-Fang

    2018-02-01

    High photocatalytic activity and photostability are the pursuit of the goal for designing promising photocatalysts. Herein, using ZnO to encapsulate ZnS nanoparticles is proposed as an effective strategy to enhance photocatalytic activity and anti-photocorrosion. The ZnS/ZnO core/shell heterostructures are obtained via an annealing treatment of ZnS nanoparticles produced by a facile wet chemical approach. Due to its small size, the nascent cubic sphalerite ZnS (s-ZnS) converts into a hexagonal wurtzite ZnS (w-ZnS)/ZnO core/shell structure after annealing treatment. In situ oxidation leads to increasing ZnO, simultaneously decreasing the w-ZnS content in the resultant w-ZnS/ZnO with thermal annealing time. The w-ZnS/ZnO core/shell heterostructures show high photocatalytic activity, demonstrated by the photodegradation rate of methylene blue being up to ten-fold and seven-fold higher than that of s-ZnS under UV and visible light irradiation, respectively, and the high capability of degrading rhodamine B. The enhanced photocatalytic activity may be attributed to the large specific surface and improved charge carrier separation at the core/shell interface. Moreover, it displays high photostability owing to the protection of the ZnO shell, greatly inhibiting the photocorrosion of ZnS. This facile in situ oxidation is effective and easily scalable, providing opportunities for developing novel core/shell structure photocatalysts with high activity and photostability.

  10. Studies on antimony absorption on Carbon steel (CS) and magnetite coated CS at high temperature to investigate the problem of out of core Sb activity in PHWRs

    International Nuclear Information System (INIS)

    Keny, S.J.; Gokhale, B.K.; Kumbhar, A.G.; Bera, Santanu; Velmurugan, S.

    2014-01-01

    Sb from PHT (primary heat transfer) pump bearings of PHWRs (Pressurized Heavy Water Reactors) goes to the reactor core and gets activated to 121 Sb and 123 Sb. Subsequently, it deposits on out of core surface resulting in radiation exposure to station personnel's apparent high decontamination factors. Sb, thus deposited can't be impassivated by normal decontamination process. Earlier studies indicates lattice substitution of Sb +3 for Fe +2 in magnetite at low doping levels (≤5%). This process, at reactor conditions is yet to be well understood. To formulate an adequate decontamination formulation and methodology and for having insight at Sb deposition mechanism under rector conditions studies are performed

  11. Post-processor for simulations of the ORIGEN program and calculation of the composition of the activity of a burnt fuel core by a BWR type reactor

    International Nuclear Information System (INIS)

    Sandoval V, S.

    2006-01-01

    The composition calculation and the activity of nuclear materials subject to processes of burnt, irradiation and decay periods are of utility for diverse activities inside the nuclear industry, as they are it: the processes design and operations that manage radioactive material, the calculation of the inventory and activity of a core of burnt nuclear fuel, for studies of type Probabilistic Safety Analysis (APS), as well as for regulation processes and licensing of nuclear facilities. ORIGEN is a program for computer that calculates the composition and the activity of nuclear materials subject to periods of burnt, irradiation and decay. ORIGEN generates a great quantity of information whose processing and analysis are laborious, and it requires thoroughness to avoid errors. The automation of the extraction, conditioning and classification of that information is of great utility for the analyst. By means of the use of the post-processor presented in this work it is facilitated, it speeds up and wide the capacity of analysis of results, since diverse consultations with several classification options and filtrate of results can be made. As illustration of the utility of the post-processor, and as an analysis of interest for itself, it is also presented in this work the composition of the activity of a burned core in a BWR type reactor according to the following classification criteria: by type of radioisotope (fission products, activation products and actinides), by specie type (gassy, volatile, semi-volatile and not volatile), by element and by chemical group. The results show that the total activity of the studied core is dominated by the fission products and for the actinides, in proportion four to one, and that the gassy and volatile species conform a fifth part of the total activity of the core. (Author)

  12. Study of thermal - hydraulic sensors signal fluctuations in PWR

    International Nuclear Information System (INIS)

    Hennion, F.

    1987-10-01

    This thesis deals with signal fluctuations of thermal-hydraulic sensors in the main coolant primary of a pressurized water reactor. The aim of this work is to give a first response about the potentiality of use of these noise signals for the functionning monitoring. Two aspects have been studied: - the modelisation of temperature fluctuations of core thermocouples, by a Monte-Carlo method, gives the main characteristics of these signals and their domain of application. - the determination of eigenfrequency in the primary by an acoustic representation could permit the monitoring of local and global thermo-hydraulic conditions [fr

  13. Current density fluctuations and ambipolarity of transport

    International Nuclear Information System (INIS)

    Shen, W.; Dexter, R.N.; Prager, S.C.

    1991-10-01

    The fluctuation in the plasma current density is measured in the MIST reversed field pinch experiment. Such fluctuations, and the measured radial profile of the k spectrum of magnetic fluctuations, supports the view and that low frequency fluctuations (f r >) demonstrates that radial particle transport from particle motion parallel to a fluctuating magnetic field is ambipolar over the full frequency range

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

    Science.gov (United States)

    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 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.

  15. Internal Medicine Residency Program Directors' Views of the Core Entrustable Professional Activities for Entering Residency: An Opportunity to Enhance Communication of Competency Along the Continuum.

    Science.gov (United States)

    Angus, Steven V; Vu, T Robert; Willett, Lisa L; Call, Stephanie; Halvorsen, Andrew J; Chaudhry, Saima

    2017-06-01

    To examine internal medicine (IM) residency program directors' (PDs') perspectives on the Core Entrustable Professional Activities for Entering Residency (Core EPAs)-introduced into undergraduate medical education to further competency-based assessment-and on communicating competency-based information during transitions. A spring 2015 Association of Program Directors in Internal Medicine survey asked PDs of U.S. IM residency programs for their perspectives on which Core EPAs new interns must or should possess on day 1, which are most essential, and which have the largest gap between expected and observed performance. Their views and preferences were also requested regarding communicating competency-based information at transitions from medical school to residency and residency to fellowship/employment. The response rate was 57% (204/361 programs). The majority of PDs felt new interns must/should possess 12 of the 13 Core EPAs. PDs' rankings of Core EPAs by relative importance were more varied than their rankings by the largest gaps in performance. Although preferred timing varied, most PDs (82%) considered it important for medical schools to communicate Core EPA-based information to PDs; nearly three-quarters (71%) would prefer a checklist format. Many (60%) would be willing to provide competency-based evaluations to fellowship directors/employers. Most (> 80%) agreed that there should be a bidirectional communication mechanism for programs/employers to provide feedback on competency assessments. The gaps identified in Core EPA performance may help guide medical schools' curricular and assessment tool design. Sharing competency-based information at transitions along the medical education continuum could help ensure production of competent, practice-ready physicians.

  16. A study of power fluctuations in a flip fuel reactor using the technique of noise analysis

    Energy Technology Data Exchange (ETDEWEB)

    Randall, J D; Wood, G C; Edwards, M A [Texas A and M University (United States)

    1974-07-01

    The Nuclear Science Center Reactor at Texas A and M University has experienced minor power fluctuations when operating at or near 1 megawatt. A noise analysis system was developed to investigate these fluctuations assuming that void formation, primarily due to nucleate boiling, was the cause. Experiments were carried out to correlate boiling noise with power level, fission product poisoning, and pool temperature. Results show that void formation in the core is the probable cause of the fluctuations with the onset of boiling occurring at 400 Kw. Data was also obtained that indicated the presence of boiling in a standard TRIGA core. (author)

  17. Activities of research-reactor-technology project in FNCA from FY2005 to FY2007. Sharing neutronics calculation technique for core management and utilization of research reactors

    International Nuclear Information System (INIS)

    2010-07-01

    RRT project (Research-Reactor-Technology Project) was carried out with the theme of 'sharing neutronics calculation technique for core management and utilization of research reactors' in the framework of FNCA (Forum for Nuclear Cooperation in Asia) from FY2005 to FY2007. The objective of the project was to improve and equalize the level of neutronics calculation technique for the reactor core management among participating countries to assure the safe and stable operation of research reactors and the promotion of the effective utilization. Neutronics calculation codes, namely SRAC code system and MVP code, were adopted as common codes. Participating countries succeeded in applying the common codes to analyzing the core of each domestic research reactor. Some participating countries succeeded in applying the common codes to analyzing for utilization of own research reactors. Activities of RRT project have improved and equalized the level of neutronics calculation technique among participating countries. (author)

  18. 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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Measurement of nitrophenols in rain and air by two-dimensional liquid chromatography-chemically active liquid core waveguide spectrometry.

    Science.gov (United States)

    Ganranoo, Lucksagoon; Mishra, Santosh K; Azad, Abul K; Shigihara, Ado; Dasgupta, Purnendu K; Breitbach, Zachary S; Armstrong, Daniel W; Grudpan, Kate; Rappenglueck, Bernhard

    2010-07-01

    We report a novel system to analyze atmospheric nitrophenols (NPs). Rain or air sample extracts (1 mL) are preconcentrated on a narrow bore (2 mm) aliphatic anion exchanger. In the absence of strong retention of NPs exhibited by aromatic ion exchangers, retained NPs are eluted as a plug by injection of 100 microL of 0.1 M Na(2)SO(4) on to a short (2 x 50 mm) reverse phase C-18 column packed with 2.2 mum particles. The salt plug passes through the C-18 column unretained while the NPs are separated by an ammonium acetate buffered methanol-water eluent, compatible with mass spectrometry (MS). The eluted NPs are measured with a long path Teflon AF-based liquid core waveguide (0.15 x 1420 mm) illuminated by a 403 nm light emitting diode and detected by a monolithic photodiode-operational amplifier. The waveguide is rendered chemically active by suspending it over concentrated ammonia that permeates into the lumen. The NPs ionize to the yellow anion form (lambda(max) approximately 400 nm). The separation of 4-nitrophenol, 2,4-dinitrophenol, 2-methyl-4-nitrophenol, 3-methyl-4-nitrophenol, and 2-nitrophenol (these are the dominant NPs, typically in that order, in both rain and air of Houston and Arlington, TX, confirmed by tandem MS) takes just over 5 min with respective S/N = 3 limits of detection (LODs) of 60, 12, 30, 67, and 23 pg/mL compared to MS/MS LODs of 20, 49, 11, 20, and 210 pg/mL. Illustrative air and rain data are presented.

  1. Size effects in many-valley fluctuations in semiconductors

    International Nuclear Information System (INIS)

    Sokolov, V.N.; Kochelap, V.A.

    1995-08-01

    We present the results of theoretical investigations of nonhomogeneous fluctuations in submicron active regions of many-valley semiconductors with equivalent valleys(Ge, Si-type), where the dimension 2d of the region is comparable to or less than the intervalley diffusion relaxation length L iv . It is shown that for arbitrary orientations of the valley axes (the crystal axes) with respect to lateral sample surfaces, the fluctuation spectra depend on the bias voltage applied to the layer in the region of weak nonheating electric fields. The new physical phenomenon is reported: the fluctuation spectra depend on the sample thickness, with 2d iv the suppression of fluctuations arises for fluctuation frequencies ω -1 iv , τ -1 iv is the characteristic intervalley relaxation time. (author). 43 refs, 5 figs

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Critical fluctuations in cortical models near instability

    Directory of Open Access Journals (Sweden)

    Matthew J. Aburn

    2012-08-01

    Full Text Available Computational studies often proceed from the premise that cortical dynamics operate in a linearly stable domain, where fluctuations dissipate quickly and show only short memory. Studies of human EEG, however, have shown significant autocorrelation at time lags on the scale of minutes, indicating the need to consider regimes where nonlinearities influence the dynamics. Statistical properties such as increased autocorrelation length, increased variance, power-law scaling and bistable switching have been suggested as generic indicators of the approach to bifurcation in nonlinear dynamical systems. We study temporal fluctuations in a widely-employed computational model (the Jansen-Rit model of cortical activity, examining the statistical signatures that accompany bifurcations. Approaching supercritical Hopf bifurcations through tuning of the background excitatory input, we find a dramatic increase in the autocorrelation length that depends sensitively on the direction in phase space of the input fluctuations and hence on which neuronal subpopulation is stochastically perturbed. Similar dependence on the input direction is found in the distribution of fluctuation size and duration, which show power law scaling that extends over four orders of magnitude at the Hopf bifurcation. We conjecture that the alignment in phase space between the input noise vector and the center manifold of the Hopf bifurcation is directly linked to these changes. These results are consistent with the possibility of statistical indicators of linear instability being detectable in real EEG time series. However, even in a simple cortical model, we find that these indicators may not necessarily be visible even when bifurcations are present because their expression can depend sensitively on the neuronal pathway of incoming fluctuations.

  5. Localized description of valence fluctuations

    International Nuclear Information System (INIS)

    Alascio, B.; Allub, R.; Aligia, A.

    1979-07-01

    The authors set up a model for intermediate valence equivalent to the ''atomic'' limit of the Anderson Hamiltonian. Detailed analysis of this model shows that most of the essential characteristics of valence fluctuators are already present in this crudely simplified Hamiltonian. The spin-spin and the 4f charge-charge correlation functions are studied and it is shown that it is possible to define a spin fluctuation frequency ωsub(s.f.) and a charge fluctuation frequency ωsub(ch.f.).ωsub(s.f.) and ωsub(ch.f.) can differ considerably for some values of the parameters of the model. The magnetic susceptibility and the specific heat are calculated as functions of temperature and it is shown how the results simulate the behaviour found in valence fluctuators. (author)

  6. The Fluctuation Niche in Plants

    Directory of Open Access Journals (Sweden)

    Jaume Terradas

    2009-01-01

    Full Text Available Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and ecophysiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and interannual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.

  7. The Fluctuation Niche in Plants

    International Nuclear Information System (INIS)

    Terradas, J.; Penuelas, J.; Lloret, F.; Penuelas, J.

    2009-01-01

    Classical approaches to niche in coexisting plants have undervalued temporal fluctuations. We propose that fluctuation niche is an important dimension of the total niche and interacts with habitat and life-history niches to provide a better understanding of the multidimensional niche space where ecological interactions occur. To scale a fluctuation niche, it is necessary to relate environmental constrictions or species performance not only to the absolute values of the usual environmental and eco physiological variables but also to their variances or other measures of variability. We use Mediterranean plant communities as examples, because they present characteristic large seasonal and inter annual fluctuations in water and nutrient availabilities, along an episodic-constant gradient, and because the plant responses include a number of syndromes coupled to this gradient.

  8. Insects in fluctuating thermal environments.

    Science.gov (United States)

    Colinet, Hervé; Sinclair, Brent J; Vernon, Philippe; Renault, David

    2015-01-07

    All climate change scenarios predict an increase in both global temperature means and the magnitude of seasonal and diel temperature variation. The nonlinear relationship between temperature and biological processes means that fluctuating temperatures lead to physiological, life history, and ecological consequences for ectothermic insects that diverge from those predicted from constant temperatures. Fluctuating temperatures that remain within permissive temperature ranges generally improve performance. By contrast, those which extend to stressful temperatures may have either positive impacts, allowing repair of damage accrued during exposure to thermal extremes, or negative impacts from cumulative damage during successive exposures. We discuss the mechanisms underlying these differing effects. Fluctuating temperatures could be used to enhance or weaken insects in applied rearing programs, and any prediction of insect performance in the field-including models of climate change or population performance-must account for the effect of fluctuating temperatures.

  9. Nonequilibrium quantum fluctuations of work.

    Science.gov (United States)

    Allahverdyan, A E

    2014-09-01

    The concept of work is basic for statistical thermodynamics. To gain a fuller understanding of work and its (quantum) features, it needs to be represented as an average of a fluctuating quantity. Here I focus on the work done between two moments of time for a thermally isolated quantum system driven by a time-dependent Hamiltonian. I formulate two natural conditions needed for the fluctuating work to be physically meaningful for a system that starts its evolution from a nonequilibrium state. The existing definitions do not satisfy these conditions due to issues that are traced back to noncommutativity. I propose a definition of fluctuating work that is free of previous drawbacks and that applies for a wide class of nonequilibrium initial states. It allows the deduction of a generalized work-fluctuation theorem that applies for an arbitrary (out-of-equilibrium) initial state.

  10. Quantum fluctuations in insulating ferroelectrics

    International Nuclear Information System (INIS)

    Riseborough, Peter S.

    2010-01-01

    Graphical abstract: It has been proposed that in a ferroelectric insulator, an applied magnetic field may couple the transverse phonon modes and produce left and right circularly polarized phonon modes which are no longer degenerate. We quantize the theory and examine the effects of quantal fluctuations. In particular, we show that the zero point fluctuations result in a large diamagnetic contribution to the magnetic susceptibility. - Abstract: It has been proposed that in a ferroelectric insulator, an applied magnetic field may couple the transverse phonon modes and produce left and right circularly polarized phonon modes which are no longer degenerate. We quantize the theory and examine the effects of quantal fluctuations. In particular, we show that the zero-point fluctuations result in a large diamagnetic contribution to the magnetic susceptibility.

  11. Fluctuations and Instability in Sedimentation

    KAUST Repository

    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.

  12. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2008-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  13. Transformer core

    NARCIS (Netherlands)

    Mehendale, A.; Hagedoorn, Wouter; Lötters, Joost Conrad

    2010-01-01

    A transformer core includes a stack of a plurality of planar core plates of a magnetically permeable material, which plates each consist of a first and a second sub-part that together enclose at least one opening. The sub-parts can be fitted together via contact faces that are located on either side

  14. Broadband magnetic and density fluctuations in the TCA tokamak

    International Nuclear Information System (INIS)

    Hollenstein, Ch.; Keller, R.; Pochelon, A.; Ryter, F.; Sawley, M.L.; Simm, W.; Weisen, H.

    1987-01-01

    The results of comparative studies of broadband magnetic and density fluctuations during ohmic discharges in the TCA tokamak are described. Long coherence lengths are observed in poloidal and toroidal directions between magnetic probes in the scrape-off layer. A phase contrast diagnostic provides a newly accessible range of density fluctuations in the bulk plasma with very long wavelengths. Langmuir probes provide similar measurements in the scrape-off layer. Statistical dispersion relations for both density and magnetic fluctuations are deduced and are shown to be substantially different. Low mean poloidal wavenumbers (m ∼ 2 at 100 kHz) are obtained for the magnetic fluctuations, in contrast to the much higher values measured for density fluctuations. The difference between magnetic and density fluctuations is also reflected in different scalings with plasma parameters and with electron confinement time. The helicity of the coherent magnetic structures is analyzed to show that interior regions of the plasma, such as the q = 2 region contribute to the magnetic activity at the edge. This explains why the magnetic fluctuations measured at the edge are likely to reflect the confinement properties of the bulk plasma. The results of detailed probe rotation experiments and coherence measurements give indications of the physical nature and origin of magnetic fluctuations

  15. Principle of minimal work fluctuations.

    Science.gov (United States)

    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)].

  16. Visible-light photochemical activity of heterostructured core-shell materials composed of selected ternary titanates and ferrites coated by tiO2.

    Science.gov (United States)

    Li, Li; Liu, Xuan; Zhang, Yiling; Nuhfer, Noel T; Barmak, Katayun; Salvador, Paul A; Rohrer, Gregory S

    2013-06-12

    Heterostructured photocatalysts comprised of microcrystalline (mc-) cores and nanostructured (ns-) shells were prepared by the sol-gel method. The ability of titania-coated ATiO3 (A = Fe, Pb) and AFeO3 (A = Bi, La, Y) catalysts to degrade methylene blue in visible light (λ > 420 nm) was compared. The catalysts with the titanate cores had enhanced photocatalytic activities for methylene blue degradation compared to their components alone, whereas the catalysts with ferrite cores did not. The temperature at which the ns-titania shell is crystallized influences the photocatalytic dye degradation. mc-FeTiO3/ns-TiO2 annealed at 500 °C shows the highest reaction rate. Fe-doped TiO2, which absorbs visible light, did not show enhanced photocatalytic activity for methylene blue degradation. This result indicates that iron contamination is not a decisive factor in the reduced reactivity of the titania coated ferrite catalysts. The higher reactivity of materials with the titanate cores suggests that photogenerated charge carriers are more easily transported across the titanate-titanate interface than the ferrite-titanate interface and this provides guidance for materials selection in composite catalyst design.

  17. Fabrication of SnO{sub 2}-TiO{sub 2} core-shell nanopillar-array films for enhanced photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Hsyi-En, E-mail: sean@mail.stust.edu.tw; Lin, Chun-Yuan; Hsu, Ching-Ming

    2017-02-28

    Highlights: • SnO{sub 2}-TiO{sub 2} core-shell nanopillar-arrays on ITO glass were successfully fabricated. • The 3D heterojunction solves the problem of low photocatalytic activity of TiO{sub 2} films. • SnO{sub 2} is more suitable than ITO for the core layer to separate electron-hole pairs. - Abstract: Immobilized or deposited thin film TiO{sub 2} 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 TiO{sub 2} can be effectively improved by the SnO{sub 2}-TiO{sub 2} core-shell nanopillar-array structure which combines the benefits of SnO{sub 2}/TiO{sub 2} heterojunction and high reaction surface area. The SnO{sub 2}-TiO{sub 2} 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 TiO{sub 2} film was 45% improved by introducing a SnO{sub 2} film between TiO{sub 2} and ITO glass substrate and was 300% improved by using the SnO{sub 2}-TiO{sub 2} core-shell nanopillar-array structure. The 45% improvement by the SnO{sub 2} interlayer is attributed to the SnO{sub 2}/TiO{sub 2} heterojunction which separates the photogenerated electron-hole pairs in TiO{sub 2} for MB degradation, and the high photocatalytic activity of the SnO{sub 2}-TiO{sub 2} core-shell nanopillar-array films is attributed to the three dimensional SnO{sub 2}/TiO{sub 2} heterojunction which owns both the carrier separation ability and the high photocatalytic reaction surface area.

  18. A portable and independent edge fluctuation diagnostic

    International Nuclear Information System (INIS)

    Tsui, H.Y.W.; Ritz, C.P.; Wootton, A.J.

    1991-01-01

    The measurements of fluctuations and its associated transport with Langmuir probes have provided essential experimental information for some understanding of the turbulent transport. While such measurements have been conducted in the edge region of several tokamaks, only limited effort has been devoted to link and to consolidate these results: such effort can provide information for a more global understanding of the transport process. The purpose of this project is to provide a portable diagnostic facility to measure the edge turbulence on different devices, a signal processing package to analyze the data in a systematic manner and a database to consolidate the experimental results. The end product which provides a collection of information for the comparisons with the theoretical models may lead to a more global understanding of the transport process. A compact self contained portable system has been designed and developed to diagnose the edge plasma of devices with a wide range of sizes and configurations. The system is capable of measuring both the mean and the fluctuation quantities of density, temperature and potential from a standardized Langmuir probe array using a fast reciprocating probe drive. The system can also be used for other fluctuation diagnostics, such as magnetic probes, if necessary. The data acquisition and analysis is performed on a Macintosh 2fx which provides a user-friendly environment. The results obtained by the signal processing routines are stored in a tabloid format to allow comparative studies. The database is a core part of the portable signal analysis system. It allows a fast display of shot data versus each other, as well as comparison between different devices

  19. Limitation and suppression of hot electron fluctuations in submicron semiconductor structures

    International Nuclear Information System (INIS)

    Kochelap, V.A.; Zahleniuk, N.A.; Sokolov, V.N.

    1992-09-01

    We present theoretical investigations of fluctuations of hot electrons in submicron active regions, where the dimensions 2 d of the region is comparable to the electron energy relaxation length L ε . The new physical phenomenon is reported; the fluctuations depend on the sample thickness, with 2d ε a suppression of fluctuations arises in the range of fluctuation frequencies ω much less than T -1 ε , T ε is the electron energy relaxation time. (author). 12 refs, 7 figs

  20. Core lifter

    Energy Technology Data Exchange (ETDEWEB)

    Pavlov, N G; Edel' man, Ya A

    1981-02-15

    A core lifter is suggested which contains a housing, core-clamping elements installed in the housing depressions in the form of semirings with projections on the outer surface restricting the rotation of the semirings in the housing depressions. In order to improve the strength and reliability of the core lifter, the semirings have a variable transverse section formed from the outside by the surface of the rotation body of the inner arc of the semiring aroung the rotation axis and from the inner a cylindrical surface which is concentric to the outer arc of the semiring. The core-clamping elements made in this manner have the possibility of freely rotating in the housing depressions under their own weight and from contact with the core sample. These semirings do not have weakened sections, have sufficient strength, are inserted into the limited ring section of the housing of the core lifter without reduction in its through opening and this improve the reliability of the core lifter in operation.

  1. Core/shell Fe{sub 3}O{sub 4}/BiOI nanoparticles with high photocatalytic activity and stability

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Liyun, E-mail: zhengliyun@126.com [Hebei University of Engineering, College of Materials Science and Engineering (China); Wang, Shuling; Zhao, Lixin [Hebei University of Engineering, College of Mechanical and Equipment Engineering (China); Zhao, Shuguo [Handan Polytechnic College, Mechanical and Electrical Department (China)

    2016-11-15

    Core/shell Fe{sub 3}O{sub 4}/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 Fe{sub 3}O{sub 4} 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 Fe{sub 3}O{sub 4}/BiOI catalysts reached 98 % after 40-min irradiation. The catalytic performance enhancement of the core/shell Fe{sub 3}O{sub 4}/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 Fe{sub 3}O{sub 4} 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 Fe{sub 3}O{sub 4}/BiOI nanoparticles have excellent photocatalytic stability and are recyclable for decomposing organic pollutants under visible light irradiation.

  2. Spatial variability in photosynthetic and heterotrophic activity drives localized δ13C org fluctuations and carbonate precipitation in hypersaline microbial mats.

    Science.gov (United States)

    Houghton, J; Fike, D; Druschel, G; Orphan, V; Hoehler, T M; Des Marais, D J

    2014-11-01

    Modern laminated photosynthetic microbial mats are ideal environments to study how microbial activity creates and modifies carbon and sulfur isotopic signatures prior to lithification. Laminated microbial mats from a hypersaline lagoon (Guerrero Negro, Baja California, Mexico) maintained in a flume in a greenhouse at NASA Ames Research Center were sampled for δ(13) C of organic material and carbonate to assess the impact of carbon fixation (e.g., photosynthesis) and decomposition (e.g., bacterial respiration) on δ(13) C signatures. In the photic zone, the δ(13) C org signature records a complex relationship between the activities of cyanobacteria under variable conditions of CO2 limitation with a significant contribution from green sulfur bacteria using the reductive TCA cycle for carbon fixation. Carbonate is present in some layers of the mat, associated with high concentrations of bacteriochlorophyll e (characteristic of green sulfur bacteria) and exhibits δ(13) C signatures similar to DIC in the overlying water column (-2.0‰), with small but variable decreases consistent with localized heterotrophic activity from sulfate-reducing bacteria (SRB). Model results indicate respiration rates in the upper 12 mm of the mat alter in situ pH and HCO3- concentrations to create both phototrophic CO2 limitation and carbonate supersaturation, leading to local precipitation of carbonate minerals. The measured activity of SRB with depth suggests they variably contribute to decomposition in the mat dependent on organic substrate concentrations. Millimeter-scale variability in the δ(13) C org signature beneath the photic zone in the mat is a result of shifting dominance between cyanobacteria and green sulfur bacteria with the aggregate signature overprinted by heterotrophic reworking by SRB and methanogens. These observations highlight the impact of sedimentary microbial processes on δ(13) C org signatures; these processes need to be considered when attempting to relate

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

    Energy Technology Data Exchange (ETDEWEB)

    Bakina, O. V., E-mail: ovbakina@ispms.tsc.ru; Fomenko, A. N., E-mail: alserova@ispms.tsc.ru; Korovin, M. S., E-mail: msk@ispms.tsc.ru; Glazkova, E. A., E-mail: eagl@ispms.tsc.ru; Svarovskaya, N. V., E-mail: nvsv@ispms.tsc.ru [Institute of Strength Physics and Materials Sciences SB RAS, Akademicheskii Pr. 2/4, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Lenin Avenue 30, Tomsk, 634050 (Russian Federation)

    2016-08-02

    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.

  4. Fluctuation analysis of rotational spectra

    International Nuclear Information System (INIS)

    Doessing, T.; Bracco, A.; Broglia, R.A.; Matsuo, M.

    1996-01-01

    The compound state rotational degree of freedom is ''damped'' in the sense that the electric quadrupole decay of a single quantum state with angular momentum I exhibits a spectrum of final states all having spin I-2. In actual experiments, the cascade of γ-rays associated with each of the members of the ensemble of compound nuclei uses each of the ''discrete'' transitions many more times than the ''continuum'' transitions. Relatively large and small fluctuations in the recorded coincidence spectrum ensue, respectively. The analysis of the fluctuations will be shown to be instrumental to gain insight into the phenomenon of rotational damping. For this purpose, two- and higher-fold coincidence spectra emitted from rotating nuclei are analyzed with respect to the count fluctuations. The coincidences from consecutive γ-rays emitted from discrete rotational bands generate ridges in the E γ1 .E γ2 spectrum, and the fluctuation analysis of the ridges is based upon the ansatz of a random selection of transition energies from band to band. This ansatz is supported by a cranked mean-field calculation for the nucleus 168 Yb, as well as by analyzing resolved bands in 168 Yb and its neighbors. The fluctuation analysis of the central valley (E γ1 =E γ2 ) is based upon the ansatz of fluctuations in the intensity of the transitions of Porter-Thomas type superposed on a smooth spectrum of transition energies. This ansatz is again supported by a mixed-band calculation. The mathematical treatment of count fluctuations is formulated in general (orig.)

  5. Parameter Sensitivity Study of the Unreacted-Core Shrinking Model: A Computer Activity for Chemical Reaction Engineering Courses

    Science.gov (United States)

    Tudela, Ignacio; Bonete, Pedro; Fullana, Andres; Conesa, Juan Antonio

    2011-01-01

    The unreacted-core shrinking (UCS) model is employed to characterize fluid-particle reactions that are important in industry and research. An approach to understand the UCS model by numerical methods is presented, which helps the visualization of the influence of the variables that control the overall heterogeneous process. Use of this approach in…

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

    Science.gov (United States)

    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…

  7. An Efficient Null Model for Conformational Fluctuations in Proteins

    DEFF Research Database (Denmark)

    Harder, Tim Philipp; Borg, Mikael; Bottaro, Sandro

    2012-01-01

    Protein dynamics play a crucial role in function, catalytic activity, and pathogenesis. Consequently, there is great interest in computational methods that probe the conformational fluctuations of a protein. However, molecular dynamics simulations are computationally costly and therefore are often...... limited to comparatively short timescales. TYPHON is a probabilistic method to explore the conformational space of proteins under the guidance of a sophisticated probabilistic model of local structure and a given set of restraints that represent nonlocal interactions, such as hydrogen bonds or disulfide...... on conformational fluctuations that is in correspondence with experimental measurements. TYPHON provides a flexible, yet computationally efficient, method to explore possible conformational fluctuations in proteins....

  8. Enhanced visible light photocatalytic activity in SnO{sub 2}@g-C{sub 3}N{sub 4} core-shell structures

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Hao; Zhao, Xiaoru, E-mail: xrzhao@nwpu.edu.cn; Duan, Libing; Liu, Ruidi; Li, Hui

    2017-04-15

    Highlights: • Novel SnO{sub 2}@g-C{sub 3}N{sub 4} core-shell structures were successfully synthesized. • The core-shell structures exhibited enhanced visible light photocatalytic activity. • The enhanced photocatalytic activity was due to synergic action of SnO{sub 2} and g-C{sub 3}N{sub 4}. - Abstract: SnO{sub 2}@g-C{sub 3}N{sub 4} core-shell structures were successfully synthesized by simple calcination of SnO{sub 2} microspheres and urea in a muffle furnace. The investigation of morphologies and microstructures showed that g-C{sub 3}N{sub 4} was wrapped tightly on the surface of SnO{sub 2} microspheres with large intimate interface contact areas between the g-C{sub 3}N{sub 4} shells and SnO{sub 2} cores. The X-ray photoelectron spectroscopy results and photoluminescence spectra demonstrated that the intimate interface contacts could facilitate the transfer and separation of the photogenerated charge carriers at their interface, thus the recombination of the photogenerated electron-hole pairs was impeded. The photocatalytic activity of the synthesized composites was evaluated by the photodegradation of methyl orange under visible light irradiation. It was found that SnO{sub 2}@g-C{sub 3}N{sub 4} exhibited higher photodegradation rate (k = 0.013 min{sup −1}) than that of g-C{sub 3}N{sub 4} (k = 0.008 min{sup −1}) and pure SnO{sub 2}. The enhanced photocatalytic activity could be attributed to the synergic action of SnO{sub 2} and g-C{sub 3}N{sub 4}.

  9. Reactor core

    International Nuclear Information System (INIS)

    Azekura, Kazuo; Kurihara, Kunitoshi.

    1992-01-01

    In a BWR type reactor, a great number of pipes (spectral shift pipes) are disposed in the reactor core. Moderators having a small moderating cross section (heavy water) are circulated in the spectral shift pipes to suppress the excess reactivity while increasing the conversion ratio at an initial stage of the operation cycle. After the intermediate stage of the operation cycle in which the reactor core reactivity is lowered, reactivity is increased by circulating moderators having a great moderating cross section (light water) to extend the taken up burnup degree. Further, neutron absorbers such as boron are mixed to the moderator in the spectral shift pipe to control the concentration thereof. With such a constitution, control rods and driving mechanisms are no more necessary, to simplify the structure of the reactor core. This can increase the fuel conversion ratio and control great excess reactivity. Accordingly, a nuclear reactor core of high conversion and high burnup degree can be attained. (I.N.)

  10. Ice Cores

    Data.gov (United States)

    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...

  11. An accelerating high-latitude jet in Earth's core

    Science.gov (United States)

    Livermore, P. W.; Finlay, C. C.; Hollerbach, R.

    2017-12-01

    Observations of the change in Earth's magnetic field, the secular variation, provide information on the motion of liquid metal within the core that is responsible for its generation. The very latest high-resolution observations from ESA's Swarm satellite mission show intense field change at high-latitude localised in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we explain this feature with a localised, nonaxisymmetric, westwards 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, and is now much stronger than typical large-scale flows inferred for the core. The current accelerating phase may be a part of a longer term fluctuation of the jet causing both eastwards and westwards 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Topics in fluctuating nonlinear hydrodynamics

    International Nuclear Information System (INIS)

    Milner, S.T.

    1986-01-01

    Models of fluctuating nonlinear hydrodynamics have enjoyed much success in explaining the effect of long-wavelength fluctuations in diverse hydrodynamic systems. This thesis explores two such problems; in both, the body of hydrodynamic assumptions powerfully constrains the predictions of a well-posed theory. The effects of layer fluctuations in smectic-A liquid crystals are first examined. The static theory (introduced by Grinstein and Pelcovits) is reviewed. Ward identities, resulting from the arbitrariness of the layering direction, are derived and exploited. The static results motivate an examination of dynamic fluctuation effects. A new sound-damping experiment is proposed that would probe singular dependence of viscosities on applied stress. A theory of Procaccia and Gitterman that reaction rates of chemically reacting binary mixtures are drastically reduced near their thermodynamic critical points is analyzed. Hydrodynamic arguments and Van Hove theory are applied, concluding that the PG idea is drastically slowed, and spatially varying composition fluctuations are at best slowed down over a narrow range of wavenumbers

  14. Electric Field Fluctuations in Water

    Science.gov (United States)

    Thorpe, Dayton; Limmer, David; Chandler, David

    2013-03-01

    Charge transfer in solution, such as autoionization and ion pair dissociation in water, is governed by rare electric field fluctuations of the solvent. Knowing the statistics of such fluctuations can help explain the dynamics of these rare events. Trajectories short enough to be tractable by computer simulation are virtually certain not to sample the large fluctuations that promote rare events. Here, we employ importance sampling techniques with classical molecular dynamics simulations of liquid water to study statistics of electric field fluctuations far from their means. We find that the distributions of electric fields located on individual water molecules are not in general gaussian. Near the mean this non-gaussianity is due to the internal charge distribution of the water molecule. Further from the mean, however, there is a previously unreported Bjerrum-like defect that stabilizes certain large fluctuations out of equilibrium. As expected, differences in electric fields acting between molecules are gaussian to a remarkable degree. By studying these differences, though, we are able to determine what configurations result not only in large electric fields, but also in electric fields with long spatial correlations that may be needed to promote charge separation.

  15. Neural evidence that human emotions share core affective properties.

    Science.gov (United States)

    Wilson-Mendenhall, Christine D; Barrett, Lisa Feldman; Barsalou, Lawrence W

    2013-06-01

    Research on the "emotional brain" remains centered around the idea that emotions like fear, happiness, and sadness result from specialized and distinct neural circuitry. Accumulating behavioral and physiological evidence suggests, instead, that emotions are grounded in core affect--a person's fluctuating level of pleasant or unpleasant arousal. A neuroimaging study revealed that participants' subjective ratings of valence (i.e., pleasure/displeasure) and of arousal evoked by various fear, happiness, and sadness experiences correlated with neural activity in specific brain regions (orbitofrontal cortex and amygdala, respectively). We observed these correlations across diverse instances within each emotion category, as well as across instances from all three categories. Consistent with a psychological construction approach to emotion, the results suggest that neural circuitry realizes more basic processes across discrete emotions. The implicated brain regions regulate the body to deal with the world, producing the affective changes at the core of emotions and many other psychological phenomena.

  16. Activity of Maly Aktru Glacier (Сentral Altai and changes tree line fluctuations in its basin for a historical period

    Directory of Open Access Journals (Sweden)

    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.

  17. Continuous high and low temperature induced a decrease of photosynthetic activity and changes in the diurnal fluctuations of organic acids in Opuntia streptacantha.

    Directory of Open Access Journals (Sweden)

    Zaida Zarely Ojeda-Pérez

    Full Text Available Opuntia plants grow naturally in areas where temperatures are extreme and highly variable in the day during the entire year. These plants survive through different adaptations to respond to adverse environmental conditions. Despite this capability, it is unknown how CAM photosynthetic activity and growth in Opuntia plantlets is affected by constant heat or cold. Therefore, the main objective of this research was to evaluate the short-term effect of high (40°C and low (4°C continuous temperatures on the photosynthetic efficiency, the organic acid content (malic acid and the relative growth rate (RGR in seven-month-old Opuntia streptacantha plantlets during 5, 10, and 15 days. Chlorophyll fluorescence analysis allowed us to determine that high temperatures negatively impact the photosynthetic efficiency of O. streptacantha plantlets, which exhibited the lowest values of maximum quantum efficiency of the photosystem II (Fv/Fm = 52%, Fv/F0 = 85%, operational quantum yield of PS (ΦPSII = 65% and relative electron transport rate (rETR = 65%, as well as highest values of basal fluorescence (F0 = 226% during 15 days of treatment. Similarly, low temperatures decreased Fv/Fm (16%, Fv/F0 (50%, ΦPSII and rETR (16%. High temperatures also decreased nocturnal acidification in approximately 34-50%, whereas low temperatures increased it by 30-36%. Additionally, both continuous temperatures affected drastically diurnal consumption of malic acid, which was related to a significant RGR inhibition, where the specific photosynthetic structure area component was the most affected. Our results allowed determining that, despite the high tolerance to extreme temperatures described for Opuntia plants, young individuals of O. streptacantha suffered photosynthetic impairment that led to the inhibition of their growth. Thus, the main findings reported in this study can help to predict the potential impact of climatic change on the establishment and survival of succulent

  18. Multiscale fluctuations in nuclear response

    International Nuclear Information System (INIS)

    Lacroix, D.; Chomaz, Ph.

    1999-01-01

    The nuclear collective response is investigated in the framework of a doorway picture in which the spreading width of the collective emotion is described as a coupling to more and more complex configurations. It is shown that this coupling induces fluctuations of the observed strength. In the case of a hierarchy of overlapping decay channels, Ericson fluctuations are observed at different scales. Methods for extracting these scales and the related lifetimes are discussed. Finally, it is shown that the coupling of different states at one level of complexity to some common decay channels at the next level, may produce interference-like patterns in the nuclear response. This quantum effect leads to anew type of fluctuations with a typical width related to the level spacing. (author)

  19. Fluctuation relations for anomalous dynamics

    International Nuclear Information System (INIS)

    Chechkin, A V; Klages, R

    2009-01-01

    We consider work fluctuation relations (FRs) for generic types of dynamics generating anomalous diffusion: Lévy flights, long-correlated Gaussian processes and time-fractional kinetics. By combining Langevin and kinetic approaches we calculate the probability distributions of mechanical and thermodynamical work in two paradigmatic nonequilibrium situations, respectively: a particle subject to a constant force and a particle in a harmonic potential dragged by a constant force. We check the transient FR for two models exhibiting superdiffusion, where a fluctuation-dissipation relation does not exist, and for two other models displaying subdiffusion, where there is a fluctuation-dissipation relation. In the two former cases the conventional transient FR is not recovered, whereas in the latter two it holds either exactly or in the long-time limit. (letter)

  20. Fluctuations in the multiparticle dynamics

    International Nuclear Information System (INIS)

    Bozek, P.; Ploszajczak, M.

    1993-01-01

    The appearance and properties of intermittent fluctuations in physical systems, in particular the formation of rare structures in transport phenomena are discussed. The distribution of fluctuations approaches a limiting log-normal statistical distribution. The log-normal distribution is introduced as a simple parametrization of the energy fluctuations leading to the subthreshold production of particles in nuclear collisions, and it is shown that it fits all available data both for total π 0 production cross section as well as the π 0 kinetic energy spectra for E/A < 90 MeV. It is suggested that the same universal distribution should also describe the subthreshold production of other hadrons like η and K. (author) 36 refs., 11 figs

  1. Multiscale fluctuations in nuclear response

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, D.; Chomaz, Ph

    1999-01-01

    The nuclear collective response is investigated in the framework of a doorway picture in which the spreading width of the collective emotion is described as a coupling to more and more complex configurations. It is shown that this coupling induces fluctuations of the observed strength. In the case of a hierarchy of overlapping decay channels, Ericson fluctuations are observed at different scales. Methods for extracting these scales and the related lifetimes are discussed. Finally, it is shown that the coupling of different states at one level of complexity to some common decay channels at the next level, may produce interference-like patterns in the nuclear response. This quantum effect leads to anew type of fluctuations with a typical width related to the level spacing. (author) 25 refs.

  2. Edge transport and fluctuation induced turbulence characteristics in early SST-1 plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kakati, B., E-mail: bharat.kakati@ipr.res.in; Pradhan, S., E-mail: pradhan@ipr.res.in; Dhongde, J.; Semwal, P.; Yohan, K.; Banaudha, M.

    2017-02-15

    Highlights: • Anomalous particle transport during the high MHD activity at SST-1. • Electrostatic turbulence is modulated by MHD activity at SST-1 tokamak. • Edge floating potential fluctuations shows poloidal long-range cross correlation. - Abstract: Plasma edge transport characteristics are known to be heavily influenced by the edge fluctuation induced turbulences. These characteristics play a critical role towards the confinement of plasma column in a Tokamak. The edge magnetic fluctuations and its subsequent effect on electrostatic fluctuations have been experimentally investigated for the first time at the edge of the SST-1 plasma column. This paper reports the correlations that exist and is experimentally been observed between the edge densities and floating potential fluctuations with the magnetic fluctuations. The edge density and floating potential fluctuations have been measured with the help of poloidally separated Langmuir probes, whereas the magnetic fluctuations have been measured with poloidally spaced Mirnov coils. Increase in magnetic fluctuations associated with enhanced MHD activities has been found to increase the floating potential and ion saturation current. These observations indicate electrostatic turbulence getting influenced with the MHD activities and reveal the edge anomalous particle transport during SST-1 tokamak discharge. Large-scale coherent structures have been observed in the floating potential fluctuations, indicating long-distance cross correlation in the poloidal directions. From bispectral analysis, a strong nonlinear coupling among the floating potential fluctuations is observed in the low-frequency range about 0–15 kHz.

  3. Phase space fluctuations and dynamics of fluctuations of collective variables

    Energy Technology Data Exchange (ETDEWEB)

    Benhassine, B.; Farine, M.; Idier, D.; Remaud, B.; Sebille, F. (Lab. de Physique Nucleaire, IN2P3/CNRS, 44 - Nantes (France) Nantes Univ., 44 (France)); Hernandez, E.S. (Dept. de Fisica, Ciudad Universitaria, Buenos Aires (Argentina))

    1992-08-03

    Within the framework of theoretical approaches based on stochastic transport equation of one-body distribution function, a numerical treatment of the fluctuations of collective observables is studied and checked in comparison with analytical results either at equilibrium or close to it. (orig.).

  4. Phase space fluctuations and dynamics of fluctuations of collective variables

    International Nuclear Information System (INIS)

    Benhassine, B.; Farine, M.; Idier, D.; Remaud, B.; Sebille, F.; Hernandez, E.S.

    1992-01-01

    Within the framework of theoretical approaches based on stochastic transport equation of one-body distribution function, a numerical treatment of the fluctuations of collective observables is studied and checked in comparison with analytical results either at equilibrium or close to it. (orig.)

  5. Decay heat and activity of the structural materials of the fuel and blanket assemblies of the second and third core of KNK II

    International Nuclear Information System (INIS)

    Winterhagen, D.

    1986-06-01

    The decay heat and activity caused by structural materials have been calculated for the fuel assemblies of KNK II (second and third core) with a residence time of 720 equivalent full-power days (efpd) and the blanket assemblies with 1880 efpd. The values are given for the different zones of the assemblies (head, active zone, fission gas plenum, foot and stellite area) for decay times from 1 to 20 years. For decay times beyond 2 years more than 80 % of the decay heat are caused by the Co60-decay, more than 60 % of which result from the stellite in the foot area [de

  6. Enhancing photocatalytic activity by using TiO2-MgO core-shell-structured nanoparticles

    International Nuclear Information System (INIS)

    Jung, Hyun Suk; Lee, Jung-Kun; Nastasi, Michael; Kim, Jeong-Ryeol; Lee, Sang-Wook; Kim, Jin Young; Park, Jong-Sung; Hong, Kug Sun; Shin, Hyunho

    2006-01-01

    Hygroscopic Mg(OH) 2 gel was topotactically decomposed on TiO 2 particle surfaces, resulting in highly nanoporous MgO-coated TiO 2 particles. The highly hygroscopic and nanoporous MgO shell absorbed more water molecules and hydroxyl groups from the environment to yield an improved photocatalytic property of the core-shell particles as compared to the uncoated TiO 2 counterpart

  7. Entropic Repulsion Between Fluctuating Surfaces

    Science.gov (United States)

    Janke, W.

    The statistical mechanics of fluctuating surfaces plays an important role in a variety of physical systems, ranging from biological membranes to world sheets of strings in theories of fundamental interactions. In many applications it is a good approximation to assume that the surfaces possess no tension. Their statistical properties are then governed by curvature energies only, which allow for gigantic out-of-plane undulations. These fluctuations are the “entropic” origin of long-range repulsive forces in layered surface systems. Theoretical estimates of these forces for simple model surfaces are surveyed and compared with recent Monte Carlo simulations.

  8. Origin of cosmological density fluctuations

    International Nuclear Information System (INIS)

    Carr, B.J.

    1984-11-01

    The density fluctuations required to explain the large-scale cosmological structure may have arisen spontaneously as a result of a phase transition in the early Universe. There are several ways in which such fluctuations may have ben produced, and they could have a variety of spectra, so one should not necessarily expect all features of the large-scale structure to derive from a simple power law spectrum. Some features may even result from astrophysical amplification mechanisms rather than gravitational instability. 128 references

  9. Holocene glacial fluctuations in southern South America

    Science.gov (United States)

    Reynhout, S.; Sagredo, E. A.; Kaplan, M. R.; Aravena, J. C.; Martini, M. A.; Strelin, J. A.; Schaefer, J. M.

    2016-12-01

    Understanding the timing and magnitude of former glacier fluctuations is critical to decipher long-term climatic trends and to unravel both natural cycles and human impact on the current glacial behavior. Despite more than seven decades of research efforts, a unifying model of Holocene glacial fluctuations in Southern South America remains elusive. Here, we present the state-of-the-art regarding the timing of Holocene glacial fluctuation in southern Patagonia-Tierra del Fuego, with a focus on a new generation of high-resolution radiocarbon and 10Be surface exposure dating chronologies. Recently acquired evidence suggest that after receding from advanced Late Glacial positions, Patagonian glaciers were for the most part close to, or even behind, present ice margins during the Early Holocene. On the other hand, emerging chronologies indicate that in some areas there were extensive expansions (century scale?) that punctuated the warm interval. Subsequently, we have evidence of multiple millennial timescale glacial advances starting in the middle Holocene. Several glacial maxima are defined by moraines and other landforms from 7000 years ago to the 19th century, with a gap sometime between 4,500 and 2,500 years ago. The last set of advances began around 800-600 years ago. Although glacial activity is documented in Patagonia at the same time as the European Little Ice Age, the extent of these glacial events are less prominent than those of the mid-Holocene. The causes that may explain these glacial fluctuations remain elusive. Finally, we discuss ongoing efforts to better define the timing and extent of Holocene glaciations in southern South America, and to establish the basis to test competing hypothesis of regional Holocene climate variability.

  10. Evaluation of the Characteristics of a Workplace Assessment Form to Assess Entrustable Professional Activities (EPAs) in an Undergraduate Surgery Core Clerkship.

    Science.gov (United States)

    Curran, Vernon R; Deacon, Diana; Schulz, Henry; Stringer, Katherine; Stone, Craig N; Duggan, Norah; Coombs-Thorne, Heidi

    2018-03-30

    Entrustable Professional Activities (EPAs) are explicit, directly observable tasks requiring the demonstration of specific knowledge, skills, and behaviors that learners are expected to perform without direct supervision once they have gained sufficient competence. Undergraduate level implementation of EPAs is relatively new. We examined the characteristics of a workplace assessment form (clinic card) as part of a formative programmatic assessment process of EPAs for a core undergraduate surgery rotation. A clinic card was introduced to assess progression towards EPA achievement in the clerkship curriculum phase. Students completing their core eight (8) week clerkship surgery rotation submitted at least 1 clinic card per week. We compiled assessment scores for the 2015 to 2016 academic year, in which EPAs were introduced, and analyzed relationships between scores and time, EPA, training site, and assessor role. We surveyed preceptors and students, and conducted a focus group with clinical discipline coordinators of all core rotations. This study took place at the Faculty of Medicine, Memorial University in St. John's, Newfoundland, Canada. Third year medical students (n = 79) who completed their core eight (8) week surgery clerkship rotation during the 2015 to 2016 academic year, preceptors, and clinical discipline coordinators participated in this study. EPAs reflecting tasks commonly performed by students were more likely to be assessed. EPAs frequently observed during preceptor-student encounters had higher entrustment ratings. Most EPAs showed increased entrustment scores over time and no significant differences in ratings between teaching sites nor preceptors and residents. Survey and focus group feedback suggest clinic cards fostered direct observation by preceptors and promoted constructive feedback on clinical tasks. A binary rating scale (entrustable/pre-entrustable) was not educationally beneficial. The findings support the feasibility, utility, catalytic

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

    Science.gov (United States)

    Fong, Shirley S M; Tam, Y T; Macfarlane, Duncan J; Ng, Shamay S M; Bae, Young-Hyeon; Chan, Eleanor W Y; Guo, X

    2015-01-01

    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 (P hamstring curl was effective in inducing a high EMG amplitude of LMF (P 0.05). 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.

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

    Directory of Open Access Journals (Sweden)

    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. On-line core monitoring with CORE MASTER / PRESTO

    International Nuclear Information System (INIS)

    Lindahl, S.O.; Borresen, S.; Ovrum, S.

    1986-01-01

    Advanced calculational tools are instrumental in improving reactor plant capacity factors and fuel utilization. The computer code package CORE MASTER is an integrated system designed to achieve this objective. The system covers all main activities in the area of in-core fuel management for boiling water reactors; design, operation support, and on-line core monitoring. CORE MASTER operates on a common data base, which defines the reactor and documents the operating history of the core and of all fuel bundles ever used

  14. Lead users' ideas on core features to support physical activity in rheumatoid arthritis: a first step in the development of an internet service using participatory design.

    Science.gov (United States)

    Revenäs, Åsa; Opava, Christina H; Åsenlöf, Pernilla

    2014-03-22

    Despite the growing evidence of the benefits of physical activity (PA) in individuals with rheumatoid arthritis (RA), the majority is not physically active enough. An innovative strategy is to engage lead users in the development of PA interventions provided over the internet. The aim was to explore lead users' ideas and prioritization of core features in a future internet service targeting adoption and maintenance of healthy PA in people with RA. Six focus group interviews were performed with a purposively selected sample of 26 individuals with RA. Data were analyzed with qualitative content analysis and quantification of participants' prioritization of most important content. Six categories were identified as core features for a future internet service: up-to-date and evidence-based information and instructions, self-regulation tools, social interaction, personalized set-up, attractive design and content, and access to the internet service. The categories represented four themes, or core aspects, important to consider in the design of the future service: (1) content, (2) customized options, (3) user interface and (4) access and implementation. This is, to the best of our knowledge, the first study involving people with RA in the development of an internet service to support the adoption and maintenance of PA.Participants helped identifying core features and aspects important to consider and further explore during the next phase of development. We hypothesize that involvement of lead users will make transfer from theory to service more adequate and user-friendly and therefore will be an effective mean to facilitate PA behavior change.

  15. Fluctuations in Overlapping Generations Economies

    DEFF Research Database (Denmark)

    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...

  16. Magnetic fluctuations in turbulent flow

    International Nuclear Information System (INIS)

    Ruzmaikin, A.A.

    1990-01-01

    For dynamo excitation of the magnetic fluctuations in infinite fluid only a sufficient large magnetic Reynolds number is needed. In a infinite region an additional condition appears. Due to the diffusion of the magnetic field through the boundaries a size of the region must be large enough compare with a correlation length of the turbulence. Author)

  17. Firm default and aggregate fluctuations

    NARCIS (Netherlands)

    Jacobson, Tor; Linde, Jesper; Roszbach, Kasper

    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

  18. Fluctuating hydrodynamics for ionic liquids

    Energy Technology Data Exchange (ETDEWEB)

    Lazaridis, Konstantinos [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States); Wickham, Logan [Department of Computer Science, Washington State University, Richland, 99354 (United States); Voulgarakis, Nikolaos, E-mail: n.voulgarakis@wsu.edu [Department of Mathematics and Statistics, Washington State University, Pullman, 99163 (United States)

    2017-04-25

    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. - Highlights: • A new fluctuating hydrodynamics method for ionic liquids. • Description of ionic liquid morphology in bulk and near electrified surfaces. • Direct comparison with experimental measurements.

  19. A facile method for preparing porous, optically active, magnetic Fe3 O4 @poly(N-acryloyl-leucine) inverse core/shell composite microspheres.

    Science.gov (United States)

    Liu, Dong; Deng, Jianping; Yang, Wantai

    2014-01-01

    The first synthesis of porous, optically active, magnetic Fe3 O4 @poly(N-acryloyl-leucine) inverse core/shell composite microspheres is reported, in which the core is constructed of chiral polymer and the shell is constructed of Fe3 O4 NPs. The microspheres integrate three significant concepts, "porosity", "chirality", and "magneticity", in one single microspheric entity. The microspheres consist of Fe3 O4 nanoparticles and porous optically active microspheres, and thus combine the advantages of both magnetic nanoparticles and porous optically active microspheres. The pore size and specific surface area of the microspheres are characterized by N2 adsorption, from which it is found that the composite microspheres possess a desirable porous structure. Circular dichroism and UV-vis absorption spectroscopy measurements demonstrate that the microspheres exhibit the expected optical activity. The microspheres also have high saturation magnetization of 14.7 emu g(-1) and rapid magnetic responsivity. After further optimization, these novel microspheres may potentially find applications in areas such as asymmetric catalysis, chiral adsorption, etc. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. On the origin of shape fluctuations of the cell nucleus.

    Science.gov (United States)

    Chu, Fang-Yi; Haley, Shannon C; Zidovska, Alexandra

    2017-09-26

    The nuclear envelope (NE) presents a physical boundary between the cytoplasm and the nucleoplasm, sandwiched in between two highly active systems inside the cell: cytoskeleton and chromatin. NE defines the shape and size of the cell nucleus, which increases during the cell cycle, accommodating for chromosome decondensation followed by genome duplication. In this work, we study nuclear shape fluctuations at short time scales of seconds in human cells. Using spinning disk confocal microscopy, we observe fast fluctuations of the NE, visualized by fluorescently labeled lamin A, and of the chromatin globule surface (CGS) underneath the NE, visualized by fluorescently labeled histone H2B. Our findings reveal that fluctuation amplitudes of both CGS and NE monotonously decrease during the cell cycle, serving as a reliable cell cycle stage indicator. Remarkably, we find that, while CGS and NE typically fluctuate in phase, they do exhibit localized regions of out-of-phase motion, which lead to separation of NE and CGS. To explore the mechanism behind these shape fluctuations, we use biochemical perturbations. We find the shape fluctuations of CGS and NE to be both thermally and actively driven, the latter caused by forces from chromatin and cytoskeleton. Such undulations might affect gene regulation as well as contribute to the anomalously high rates of nuclear transport by, e.g., stirring of molecules next to NE, or increasing flux of molecules through the nuclear pores.

  1. Reactor core

    International Nuclear Information System (INIS)

    Matsuura, Tetsuaki; Nomura, Teiji; Tokunaga, Kensuke; Okuda, Shin-ichi

    1990-01-01

    Fuel assemblies in the portions where the gradient of fast neutron fluxes between two opposing faces of a channel box is great are kept loaded at the outermost peripheral position of the reactor core also in the second operation cycle in the order to prevent interference between a control rod and the channel box due to bending deformation of the channel box. Further, the fuel assemblies in the second row from the outer most periphery in the first operation cycle are also kept loaded at the second row in the second operation cycle. Since the gradient of the fast neutrons in the reactor core is especially great at the outer circumference of the reactor core, the channel box at the outer circumference is bent such that the surface facing to the center of the reactor core is convexed and the channel box in the second row is also bent to the identical direction, the insertion of the control rod is not interfered. Further, if the positions for the fuels at the outermost periphery and the fuels in the second row are not altered in the second operation cycle, the gaps are not reduced to prevent the interference between the control rod and the channel box. (N.H.)

  2. Electrostatic fluctuations measured in low temperature helical plasmas with low collisionality

    International Nuclear Information System (INIS)

    Takeuchi, M.; Ikeda, R.; Ito, T.; Toi, K.; Suzuki, C.; Matsunaga, G.

    2004-01-01

    Electrostatic fluctuations have been measured by Langmuir probes from edge to core plasma region in low temperature helical plasmas which are produced by 2.45 GHz microwaves at very low field less than 0.1 T. The principal dimensionless parameters of the plasmas, that is, the normalized electron-ion collision frequency ν ei , and averaged plasma β φ and others are in the same range of them in high temperature plasmas, except the normalized gyro radius ρ s . The data on fluctuation characteristics from the dimensionally similar low temperature plasmas may give an important insight into the understanding of turbulent transport in high temperature plasmas. Dependences of fluctuation amplitudes on the radial electric field shear, ρ s and ν ei are investigated. Electrostatic fluctuations propagating in electron-diamagnetic drift direction have been observed in the plasma edge region and in ion-diamagnetic drift direction in the plasma core region. (authors)

  3. Reactor core for LMFBR type reactors

    International Nuclear Information System (INIS)

    Masumi, Ryoji; Azekura, Kazuo; Kurihara, Kunitoshi; Bando, Masaru; Watari, Yoshio.

    1987-01-01

    Purpose: To reduce the power distribution fluctuations and obtain flat and stable power distribution throughout the operation period in an LMFBR type reactor. Constitution: In the inner reactor core region and the outer reactor core region surrounding the same, the thickness of the inner region is made smaller than the axial height of the reactor core region and the radial width thereof is made smaller than that of the reactor core region and the volume thereof is made to 30 - 50 % for the reactor core region. Further, the amount of the fuel material per unit volume in the inner region is made to 70 - 90 % of that in the outer region. The difference in the neutron infinite multiplication factor between the inner region and the outer region is substantially constant irrespective of the burnup degree and the power distribution fluctuation can be reduced to about 2/3, by which the effect of thermal striping to the reactor core upper mechanisms can be moderated. Further, the maximum linear power during operation can be reduced by 3 %, by which the thermal margin in the reactor core is increased and the reactor core fuels can be saved by 3 %. (Kamimura, M.)

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

    KAUST Repository

    Wang, Yin; Liu, Jinyong; Wang, Peng; Werth, Charles; Strathmann, Timothy J.

    2014-01-01

    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.

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

    KAUST Repository

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

    Directory of Open Access Journals (Sweden)

    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%.

  7. DFT study of Fe-Ni core-shell nanoparticles: Stability, catalytic activity, and interaction with carbon atom for single-walled carbon nanotube growth

    International Nuclear Information System (INIS)

    Yang, Zhimin; Wang, Qiang; Shan, Xiaoye; Zhu, Hongjun; Li, Wei-qi; Chen, Guang-hui

    2015-01-01

    Metal catalysts play an important role in the nucleation and growth of single-walled carbon nanotubes (SWCNTs). It is essential for probing the nucleation and growth mechanism of SWCNTs to fundamentally understand the properties of the metal catalysts and their interaction with carbon species. In this study, we systematically studied the stability of 13- and 55-atom Fe and Fe-Ni core-shell particles as well as these particles interaction with the carbon atoms using the density functional theory calculations. Icosahedral 13- and 55-atom Fe-Ni core-shell bimetallic particles have higher stability than the corresponding monometallic Fe and Ni particles. Opposite charge transfer (or distribution) in these particles leads to the Fe surface-shell displays a positive charge, while the Ni surface-shell exhibits a negative charge. The opposite charge transfer would induce different chemical activities. Compared with the monometallic Fe and Ni particles, the core-shell bimetallic particles have weaker interaction with C atoms. More importantly, C atoms only prefer staying on the surface of the bimetallic particles. In contrast, C atoms prefer locating into the subsurface of the monometallic particles, which is more likely to form stable metal carbides. The difference of the mono- and bimetallic particles on this issue may result in different nucleation and growth mechanism of SWCNTs. Our findings provide useful insights for the design of bimetallic catalysts and a better understanding nucleation and growth mechanism of SWCNTs

  8. Role of Spontaneous Brain Activity in Explicit and Implicit Aspects of Cognitive Flexibility under Socially Conflicting Situations: A Resting-state fMRI Study using Fractional Amplitude of Low-frequency Fluctuations.

    Science.gov (United States)

    Fujino, Junya; Tei, Shisei; Jankowski, Kathryn F; Kawada, Ryosaku; Murai, Toshiya; Takahashi, Hidehiko

    2017-12-26

    We are constantly exposed to socially conflicting situations in everyday life, and cognitive flexibility is essential for adaptively coping with such difficulties. Flexible goal choice and pursuit are not exclusively conscious, and therefore cognitive flexibility involves both explicit and implicit forms of processing. However, it is unclear how individual differences in explicit and implicit aspects of flexibility are associated with neural activity in a resting state. Here, we measured intrinsic fractional amplitude of low-frequency fluctuations (fALFF) by resting-state functional magnetic resonance imaging (RS-fMRI) as an indicator of regional brain spontaneous activity, together with explicit and implicit aspects of cognitive flexibility using the Cognitive Flexibility Scale (CFS) and Implicit Association Test (IAT). Consistent with the dual processing theory, there was a strong association between explicit aspects of flexibility (CFS score) and "rationalism" thinking style and between implicit aspects (IAT effect) and "experientialism." The level of explicit flexibility was also correlated with fALFF values in the left lateral prefrontal cortex, whereas the level of implicit flexibility was correlated with fALFF values in the right cerebellum. Furthermore, the fALFF values in both regions predicted individual preference for flexible decision-making strategy in a vignettes simulation task. These results add to our understanding of the neural mechanisms underlying flexible decision-making for solving social conflicts. More generally, our findings highlight the utility of RS-fMRI combined with both explicit and implicit psychometric measures for better understanding individual differences in social cognition. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

  10. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Determination of plasma velocity from light fluctuations in a cutting torch

    International Nuclear Information System (INIS)

    Prevosto, L.; Mancinelli, B.; Kelly, H.

    2009-01-01

    Measurements of plasma velocities in a 30 A high energy density cutting torch are reported. The velocity diagnostic is based on the analysis of the light fluctuations emitted by the arc which are assumed to propagate with the flow velocity. These light fluctuations originate from plasma temperature and plasma density fluctuations mainly due to hydrodynamic instabilities. Fast photodiodes are employed as the light sensors. The arc core velocity was obtained from spectrally filtered light fluctuations measurements using a band-pass filter to detect light emission fluctuations emitted only from the arc axis. Maximum plasma jet velocities of 5000 m s -1 close to the nozzle exit and about 2000 m s -1 close to the anode were found. The obtained velocity values are in good agreement with those values predicted by a numerical code for a similar torch to that employed in this work.

  12. Real-time monitoring of disintegration activity of catalytic core domain of HIV-1 integrase using molecular beacon.

    Science.gov (United States)

    Zhang, Da-wei; Zhao, Ming-ming; He, Hong-qiu; Guo, Shun-xing

    2013-09-15

    HIV-1 integrase, an essential enzyme for retroviral replication, is a validated target for anti-HIV therapy development. The catalytic core domain of integrase (IN-CCD) is capable of catalyzing disintegration reaction. In this work, a hairpin-shaped disintegration substrate was designed and validated by enzyme-linked immunosorbent assay; a molecular beacon-based assay was developed for disintegration reaction of IN-CCD. Results showed that the disintegration substrate could be recognized and catalyzed by IN-CCD, and the disintegration reaction can be monitored according to the increase of fluorescent signal. The assay can be applied to real-time detection of disintegration with advantages of simplicity, high sensitivity, and excellent specificity. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Ghrelin receptor inverse agonists: identification of an active peptide core and its interaction epitopes on the receptor

    DEFF Research Database (Denmark)

    Holst, Birgitte; Lang, Manja; Brandt, Erik

    2006-01-01

    [D-Arg1,D-Phe5,D-Trp7,9,Leu11]Substance P functions as a low-potency antagonist but a high-potency full inverse agonist on the ghrelin receptor. Through a systematic deletion and substitution analysis of this peptide, the C-terminal carboxyamidated pentapeptide wFwLX was identified as the core...... structure, which itself displayed relatively low inverse agonist potency. Mutational analysis at 17 selected positions in the main ligand-binding crevice of the ghrelin receptor demonstrated that ghrelin apparently interacts only with residues in the middle part of the pocket [i.e., between transmembrane...... upon both AspII:20 and GluIII:09. The identified pharmacophore can possibly serve as the basis for targeted discovery of also nonpeptide inverse agonists for the ghrelin receptor....

  14. Ag-decorated Fe_3O_4@SiO_2 core-shell nanospheres: Seed-mediated growth preparation and their antibacterial activity during the consecutive recycling

    International Nuclear Information System (INIS)

    Li, Miaomiao; Wu, Wenjie; Qiao, Ru; Tan, Linxiang; Li, Zhengquan; Zhang, Yong

    2016-01-01

    We demonstrated a seed-mediated growth approach to synthesize Ag nanoparticles-decorated Fe_3O_4@SiO_2 core-shell nanospheres without use of surface functionalization. The particle size and decoration density of the immobilized Ag nanoparticles on SiO_2 surface were tunable by adjusting the added AgNO_3 concentration and the alternating repetition times in seed-mediated growth procedure. The as-prepared Ag-decorated Fe_3O_4@SiO_2 nanospheres exhibited excellent antibacterial activities against Escherichia coli, Bacillus subtilis and Candida albicans, in which the minimum inhibitory concentration were 12.5 μg mL"−"1, 50 μg mL"−"1 and 50 μg mL"−"1, respectively. It is speculated that their antibacterial activity is attributed to both the interaction of released Ag ions with the functional groups of vital enzymes and proteins and the strong oxidation of reactive oxygen species generated under the action of photoinduced electrons in Ag nanoparticles. Besides studying their antibacterial mechanism, we also investigated the variation of antibacterial activity of these heterostructured nanospheres during the consecutive magnetic separation and recycling. It shows that the magnetic antibacterial agent could be reused and its activity remained stable even after nine cycles, which enable it to be promisingly applied in biomedical areas. - Highlights: • Ag-decorated Fe_3O_4@SiO_2 were synthesized via a seed-mediated growth method. • The core-shell heterostructures exhibited excellent antibacterial activity. • The activity was attributed to the effect of released Ag"+ with ROS oxidation. • The antibacterial agent was reused during magnetic separation and recycling.

  15. Two Millennia of Pb Pollution Related to Altiplano Metallurgical Activities and Leaded Gasoline in South America from Illimani Ice Core

    Science.gov (United States)

    Eichler, A.; Gramlich, G.; Kellerhals, T.; Tobler, L.; Schwikowski, M.

    2014-12-01

    The exploitation of the extended polymetallic deposits of the Altiplano in South America led to significant emissions of the neurotoxic Pb into the atmosphere already since pre-Colonial times. Long-term histories of Pb pollution in Eastern and Western Europe, Asia, and North America suggest that within the Northern Hemisphere emissions from metallurgy and coal combustion are minor compared to that from leaded gasoline during the second half of the 20th century. However, there is no equivalent data for Southern America. Here we present the first comprehensive, high-resolution two millennia Pb emission history for South America, based on an ice core record from Illimani glacier in Bolivia. Illimani is the highest mountain of the eastern Bolivian Andes and is located at the northeastern margin of the Bolivian Altiplano. The 2000 year ice-core based decadal Pb deposition history revealed highest Pb Enrichment Factors (EFs) during the period 1965-85. Metallurgical processing for silver production during periods of the Tiwanaku culture (400-900 AD), the Inca empire (1450-1532 AD), colonial times (1532-1900 AD), and the tin production at the beginning of the 20th century were identified as major sources for enhanced Pb EFs before the 1960s. Gasoline related Pb emissions in 1965-85, however, led to a threefold increase of the Pb EFs compared to the emission level from metal production, considerably preceding those of the past 2000 years. This finding is complementary to the local air pollution signal preserved in lake sediments and in good agreement with various studies from the Northern Hemisphere.

  16. Experimental study of particle transport and density fluctuation in LHD

    International Nuclear Information System (INIS)

    Tanaka, K.; Morita, S.; Sanin, A.; Michael, C.; Kawahata, K.; Yamada, H.; Miyazawa, J.; Tokuzawa, T.; Akiyama, T.; Goto, M.; Ida, K.; Yoshinuma, M.; Narihara, K.; Yamada, I.; Yokoyama, M.; Masuzaki, S.; Morisaki, T.; Sakamoto, R.; Funaba, H.; Komori, A.; Vyacheslavov, L.N.; Murakami, S.; Wakasa, A.

    2005-01-01

    A variety of electron density (n e ) profiles have been observed in Large Helical Device (LHD). The density profiles change dramatically with heating power and toroidal magnetic field (B t ) under the same line averaged density. The particle transport coefficients, i.e., diffusion coefficient (D) and convection velocity (V) are experimentally obtained from density modulation experiments in the standard configuration. The values of D and V are estimated separately at the core and edge. The diffusion coefficients are strong function of electron temperature (T e ) and are proportional to T e 1.7±0.9 in core and T e 1.1±0.14 in edge. And edge diffusion coefficients are proportional to B t -2.08 . It is found that the scaling of D in edge is close to gyro-Bohm-like in nature. The existence of non-zero V is observed. It is observed that the electron temperature (T e ) gradient can drive particle convection. This is particularly clear in the core region. The convection velocity in the core region reverses direction from inward to outward as the T e gradient increases. In the edge, the convection is inward directed in the most of the case of the present data set. And it shows modest tendency, whose value is proportional to T e gradient keeping inward direction. However, the toroidal magnetic field also significantly affects value and direction of V. The spectrum of density fluctuation changes at different heating power suggesting that it has an influence on particle transport. The peak wavenumber is around 0.1 times the inversed ion Larmor radius, as is expected from gyro-Bohm diffusion. The peaks of fluctuation intensity are localized at the plasma edge, where density gradient becomes negative and diffusion contributes most to the particle flux. These results suggest a qualitative correlation of fluctuations with particle diffusion. (author)

  17. Experimental study of particle transport and density fluctuation in LHD

    International Nuclear Information System (INIS)

    Tanaka, K.; Michael, C.; Sanin, A.

    2005-01-01

    A variety of electron density (n e ) profiles have been observed in Large Helical Device (LHD). The density profiles change dramatically with heating power and toroidal magnetic field (B t ) under the same line averaged density. The particle transport coefficients, i.e., diffusion coefficient (D) and convection velocity (V) are experimentally obtained in the standard configuration from density modulation experiments. The values of D and V are estimated separately in the core and edge. The diffusion coefficients are found to be a strong function of electron temperature (T e ) and are proportional to T e 1.7±0.9 in the core and T e 1.1±0.14 in the edge. Edge diffusion coefficients are proportional to B t -2.08 . It is found that the scaling of D in the edge is close to gyro-Bohm-like in nature. Non-zero V is observed and it is found that the electron temperature gradient can drive particle convection, particularly in the core region. The convection velocity in the core reverses direction from inward to outward as the T e gradient increases. In the edge, convection is inward directed in most cases of the present data set. It shows a modest tendency, being proportional to T e gradient and remaining inward directed. However, the toroidal magnetic field also significantly affects the value and direction of V. The density fluctuation spectrum varies with heating power suggesting that it has an influence on particle transport. The value of K sub(perpendicular) ρ i is around 0.1, as expected for gyro-Bohm diffusion. Fluctuations are localized in both positive and negative density gradient regions of the hollow density profiles. The fluctuation power in each region is clearly distinguished having different phase velocity profiles. (author)

  18. Fluctuation current in superconducting loops

    International Nuclear Information System (INIS)

    Berger, Jorge

    2012-01-01

    A superconducting loop that encloses noninteger flux holds a permanent current. On the average, this current is also present above T c , and has been measured in recent years. We are able to evaluate the permanent current within the TDGL or the Kramer-Watts-Tobin models for loops of general configuration, i.e., we don't require uniform cross section, material or temperature. We can also consider situations in which the width is not negligible in comparison to the radius. Our results agree with experiments. The situations with which we deal at present include fluctuation superconductivity in two-band superconductors, equilibrium thermal fluctuations of supercurrent along a weak link, and ratchet effects.

  19. Fluctuations and confinement in ATF

    International Nuclear Information System (INIS)

    Isler, R.C.; Harris, J.H.; Murakami, M.

    1993-01-01

    In the period immediately prior to the suspension of ATF operation in November, 1991, a great deal of emphasis was palced on investigations of the fundamental mechanisms controlling confinement in this device. At that time, measurements of the density fluctuations throughout the plasma volume indicated the existence of theoretically predicted dissipative trapped electron and resistive interchange instabilities. These identifications were supported by results of dynamic configuration scans of the magnetic fields during which the extent of the magnetic well, shear, and fraction of confined trapped particles were changed continuously. Interpretation of the data from these experiments has been an ongoing exercise. Most recently, analysis of discharges employing strong gas puffing to change density gradients and fluctuation levels have strengthened the view that dissipative trapped electron modes may be present but do not play a significant direct role in energy transport. The present paper summarizes the current understanding concerning the identification of instabilities and their relationship to confinement in ATF

  20. Charge Fluctuations in Nanoscale Capacitors

    Science.gov (United States)

    Limmer, David T.; Merlet, Céline; Salanne, Mathieu; Chandler, David; Madden, Paul A.; van Roij, René; Rotenberg, Benjamin

    2013-09-01

    The fluctuations of the charge on an electrode contain information on the microscopic correlations within the adjacent fluid and their effect on the electronic properties of the interface. We investigate these fluctuations using molecular dynamics simulations in a constant-potential ensemble with histogram reweighting techniques. This approach offers, in particular, an efficient, accurate, and physically insightful route to the differential capacitance that is broadly applicable. We demonstrate these methods with three different capacitors: pure water between platinum electrodes and a pure as well as a solvent-based organic electrolyte each between graphite electrodes. The total charge distributions with the pure solvent and solvent-based electrolytes are remarkably Gaussian, while in the pure ionic liquid the total charge distribution displays distinct non-Gaussian features, suggesting significant potential-driven changes in the organization of the interfacial fluid.

  1. Charge fluctuations in nanoscale capacitors.

    Science.gov (United States)

    Limmer, David T; Merlet, Céline; Salanne, Mathieu; Chandler, David; Madden, Paul A; van Roij, René; Rotenberg, Benjamin

    2013-09-06

    The fluctuations of the charge on an electrode contain information on the microscopic correlations within the adjacent fluid and their effect on the electronic properties of the interface. We investigate these fluctuations using molecular dynamics simulations in a constant-potential ensemble with histogram reweighting techniques. This approach offers, in particular, an efficient, accurate, and physically insightful route to the differential capacitance that is broadly applicable. We demonstrate these methods with three different capacitors: pure water between platinum electrodes and a pure as well as a solvent-based organic electrolyte each between graphite electrodes. The total charge distributions with the pure solvent and solvent-based electrolytes are remarkably Gaussian, while in the pure ionic liquid the total charge distribution displays distinct non-Gaussian features, suggesting significant potential-driven changes in the organization of the interfacial fluid.

  2. Fluctuation theorems and atypical trajectories

    International Nuclear Information System (INIS)

    Sahoo, M; Lahiri, S; Jayannavar, A M

    2011-01-01

    In this work, we have studied simple models that can be solved analytically to illustrate various fluctuation theorems. These fluctuation theorems provide symmetries individually to the distributions of physical quantities such as the classical work (W c ), thermodynamic work (W), total entropy (Δs tot ) and dissipated heat (Q), when the system is driven arbitrarily out of equilibrium. All these quantities can be defined for individual trajectories. We have studied the number of trajectories which exhibit behaviour unexpected at the macroscopic level. As the time of observation increases, the fraction of such atypical trajectories decreases, as expected at the macroscale. The distributions for the thermodynamic work and entropy production in nonlinear models may exhibit a peak (most probable value) in the atypical regime without violating the expected average behaviour. However, dissipated heat and classical work exhibit a peak in the regime of typical behaviour only.

  3. Random numbers from vacuum fluctuations

    International Nuclear Information System (INIS)

    Shi, Yicheng; Kurtsiefer, Christian; Chng, Brenda

    2016-01-01

    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.

  4. Random numbers from vacuum fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yicheng; Kurtsiefer, Christian, E-mail: christian.kurtsiefer@gmail.com [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore); Chng, Brenda [Center for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543 (Singapore)

    2016-07-25

    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. Elucidation of the fluctuation history of cosmic radiation and global environmental using AMS

    International Nuclear Information System (INIS)

    Horiuchi, Kazuho

    2008-01-01

    Recently, accuracy of AMS has further been raised in trace amounts of sample. Besides application of 14 C to the age estimation, it has been able to restore in detail the past fluctuation of cosmic radiation strength using the other radioactive isotopes ( 10 Be, 36 Cl etc) in environmental samples and to elucidate the correlation of this with the fluctuation of climate and environment. In this report, the attempts to elucidate the fluctuation history of cosmic radiation and global environment with ice cores using AMS are presented. (M.H.)

  6. Calculation and analysis of thermal–hydraulics fluctuations in pressurized water reactors

    International Nuclear Information System (INIS)

    Malmir, Hessam; Vosoughi, Naser

    2015-01-01

    Highlights: • Single-phase thermal–hydraulics noise equations are originally derived in the frequency domain. • The fluctuations of all the coolant parameters are calculated, without any simplifying assumptions. • The radial distribution of the temperature fluctuations in the fuel, gap and cladding are taken into account. • The closed-loop calculations are performed by means of the point kinetics noise theory. • Both the space- and frequency-dependence of the thermal–hydraulics fluctuations are analyzed. - Abstract: Analysis of thermal–hydraulics fluctuations in pressurized water reactors (e.g., local and global temperature or density fluctuations, as well as primary and charging pumps fluctuations) has various applications in calculation or measurement of the core dynamical parameters (temperature or density reactivity coefficients) in addition to thermal–hydraulics surveillance and diagnostics. In this paper, the thermal–hydraulics fluctuations in PWRs are investigated. At first, the single-phase thermal–hydraulics noise equations (in the frequency domain) are originally derived, without any simplifying assumptions. The fluctuations of all the coolant parameters, as well as the radial distribution of the temperature fluctuations in the fuel, gap and cladding are taken into account. Then, the derived governing equations are discretized using the finite volume method (FVM). Based on the discretized equations and the proposed algorithm of solving, a single heated channel noise calculation code (SHC-Noise) is developed, by which the steady-state and fluctuating parameters of PWR fuel assemblies can be calculated. The noise sources include the inlet coolant temperature and velocity fluctuations, in addition to the power density noises. The developed SHC-Noise code is benchmarked in different cases and scenarios. Furthermore, to show the effects of the power feedbacks, the closed-loop calculations are performed by means of the point kinetics noise

  7. Fluctuations of radio occultation signals in sounding the Earth's atmosphere

    Directory of Open Access Journals (Sweden)

    V. Kan

    2018-02-01

    Full Text Available We discuss the relationships that link the observed fluctuation spectra of the amplitude and phase of signals used for the radio occultation sounding of the Earth's atmosphere, with the spectra of atmospheric inhomogeneities. Our analysis employs the approximation of the phase screen and of weak fluctuations. We make our estimates for the following characteristic inhomogeneity types: (1 the isotropic Kolmogorov turbulence and (2 the anisotropic saturated internal gravity waves. We obtain the expressions for the variances of the amplitude and phase fluctuations of radio occultation signals as well as their estimates for the typical parameters of inhomogeneity models. From the GPS/MET observations, we evaluate the spectra of the amplitude and phase fluctuations in the altitude interval from 4 to 25 km in the middle and polar latitudes. As indicated by theoretical and experimental estimates, the main contribution into the radio signal fluctuations comes from the internal gravity waves. The influence of the Kolmogorov turbulence is negligible. We derive simple relationships that link the parameters of internal gravity waves and the statistical characteristics of the radio signal fluctuations. These results may serve as the basis for the global monitoring of the wave activity in the stratosphere and upper troposphere.

  8. Report on investigational research on business activities under fluctuating exchange rates and the trend of energy-conservation related investments in fiscal 1995; 1995 nendo hendosuru kawase rate no motode kigyo katsudo oyobi shoene kanren toshi doko nado ni kansuru chosa kenkyu hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    A study was made on effects of fluctuation of the exchange rate on business activities in the iron/steel industry. Fluctuation of the exchange rate is an uncertain element in working out a plan for future business activities, and hinders research development and equipment investment to be positively made. In the iron/steel industry in Japan, the rate of yen basis in trade settlement currency is especially lower than in other industries, and has a constitution which is easily influenced by yen appreciation. However, the iron/steel industry is an industry exporting products, and at the same time, is an industry depending on import for most of the main raw materials. Accordingly, the yen appreciation not only has negative effects, but has different effects, depending on the rate of shifting the amount of exchange rate fluctuation to local price, and on conditions of the rate of realizing price lowering which means that the exchange rate fluctuation reflects the lowering of imported raw material prices. If only these conditions are fulfilled, the yen appreciation even produces rather favorable effects in the iron/steel industry. In the circle, the conversion of the structure is being expedited for converting effects of yen appreciation to beneficial ones. Financially, exchange risk management is also necessary. 41 figs., 35 tabs.

  9. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer’s disease (3xTgAD mice

    Directory of Open Access Journals (Sweden)

    Elysse M. Knight

    2013-01-01

    Alzheimer’s disease (AD is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD and non-transgenic (Non-Tg control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4–10 months, 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD.

  10. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer’s disease (3xTgAD) mice

    Science.gov (United States)

    Knight, Elysse M.; Brown, Timothy M.; Gümüsgöz, Sarah; Smith, Jennifer C. M.; Waters, Elizabeth J.; Allan, Stuart M.; Lawrence, Catherine B.

    2013-01-01

    SUMMARY Alzheimer’s disease (AD) is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD) and non-transgenic (Non-Tg) control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4–10 months), 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ) plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD. PMID:22864021

  11. Age-related changes in core body temperature and activity in triple-transgenic Alzheimer's disease (3xTgAD) mice.

    Science.gov (United States)

    Knight, Elysse M; Brown, Timothy M; Gümüsgöz, Sarah; Smith, Jennifer C M; Waters, Elizabeth J; Allan, Stuart M; Lawrence, Catherine B

    2013-01-01

    Alzheimer's disease (AD) is characterised, not only by cognitive deficits and neuropathological changes, but also by several non-cognitive behavioural symptoms that can lead to a poorer quality of life. Circadian disturbances in core body temperature and physical activity are reported in AD patients, although the cause and consequences of these changes are unknown. We therefore characterised circadian patterns of body temperature and activity in male triple transgenic AD mice (3xTgAD) and non-transgenic (Non-Tg) control mice by remote radiotelemetry. At 4 months of age, daily temperature rhythms were phase advanced and by 6 months of age an increase in mean core body temperature and amplitude of temperature rhythms were observed in 3xTgAD mice. No differences in daily activity rhythms were seen in 4- to 9-month-old 3xTgAD mice, but by 10 months of age an increase in mean daily activity and the amplitude of activity profiles for 3xTgAD mice were detected. At all ages (4-10 months), 3xTgAD mice exhibited greater food intake compared with Non-Tg mice. The changes in temperature did not appear to be solely due to increased food intake and were not cyclooxygenase dependent because the temperature rise was not abolished by chronic ibuprofen treatment. No β-amyloid (Aβ) plaques or neurofibrillary tangles were noted in the hypothalamus of 3xTgAD mice, a key area involved in temperature regulation, although these pathological features were observed in the hippocampus and amygdala of 3xTgAD mice from 10 months of age. These data demonstrate age-dependent changes in core body temperature and activity in 3xTgAD mice that are present before significant AD-related neuropathology and are analogous to those observed in AD patients. The 3xTgAD mouse might therefore be an appropriate model for studying the underlying mechanisms involved in non-cognitive behavioural changes in AD.

  12. Measurement of the Effective Delayed Neutron Fraction in Three Different FR0-cores

    Energy Technology Data Exchange (ETDEWEB)

    Moberg, L; Kockum, J

    1972-06-15

    The effective delayed neutron fraction, beta{sub eff}, has been measured in the three cores 3, 5 and 8 of the fast zero-power reactor FR0. The variance-to-mean method, in which the statistical fluctuations of the neutron density in the reactor is studied, was used. A 3He-gas scintillator was placed in the reflector and used as a neutron detector. It was made more sensitive to fast neutrons by surrounding it with polythene. Its efficiency, expressed as the number of counts per fission in the reactor, was determined using fission chambers with known efficiency placed in the core. The space distribution of the fission rate in the core was determined by foil activation technique. The experimental results were compared with theoretical beta{sub eff}-values calculated with perturbation theory. The difference was about 3 % which is of the same order as the accuracy in the experimental values

  13. [Towards computer-aided catalyst design: Three effective core potential studies of C-H activation]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    Research in the initial grant period focused on computational studies relevant to the selective activation of methane, the prime component of natural gas. Reaction coordinates for methane activation by experimental models were delineated, as well as the bonding and structure of complexes that effect this important reaction. This research, highlighted in the following sections, also provided the impetus for further development, and application of methods for modeling metal-containing catalysts. Sections of the report describe the following: methane activation by multiple-bonded transition metal complexes; computational lanthanide chemistry; and methane activation by non-imido, multiple-bonded ligands.

  14. Remanent magnetization stratigraphy of lunar cores

    Science.gov (United States)

    Banerjee, S. K.; Gingrich, D.; Marvin, J. A.

    1977-01-01

    Depth dependent fluctuations have been observed in the natural remanent magnetizations (NRM) of drive cores and drill strings from Apollo 16 and 17 missions. Partial demagnetization of unstable secondary magnetizations and identification of characteristic error signals from a core which is known to have been recently disturbed allow us to identify and isolate the stable NRM stratigraphy in double drive core 60010/60009 and drill strings 60002-60004. The observed magnetization fluctuations persist after normalization to take into account depth dependent variations in the carriers of stable NRM. We tentatively ascribe the stable NRM stratigraphy to instantaneous records of past magnetic fields at the lunar surface and suggest that the stable NRM stratigraphy technique could develop as a new relative time-stratigraphic tool, to be used with other physical measurements such as relative intensity of ferromagnetic resonance and charged particle track density to study the evolution of the lunar regolith.

  15. Quantum Fluctuations for Gravitational Impulsive Waves

    OpenAIRE

    Enginer, Y.; Hortacsu, M.; Ozdemir, N.

    1998-01-01

    Quantum fluctuations for a massless scalar field in the background metric of spherical impulsive gravitational waves through Minkowski and de Sitter spaces are investigated. It is shown that there exist finite fluctuations for de Sitter space.

  16. Net charge fluctuations and local charge compensation

    International Nuclear Information System (INIS)

    Fu Jinghua

    2006-01-01

    We propose net charge fluctuation as a measure of local charge correlation length. It is demonstrated that, in terms of a schematic multiperipheral model, net charge fluctuation satisfies the same Quigg-Thomas relation as satisfied by charge transfer fluctuation. Net charge fluctuations measured in finite rapidity windows depend on both the local charge correlation length and the size of the observation window. When the observation window is larger than the local charge correlation length, the net charge fluctuation only depends on the local charge correlation length, while forward-backward charge fluctuations always have strong dependence on the observation window size. Net charge fluctuations and forward-backward charge fluctuations measured in the present heavy ion experiments show characteristic features similar to those from multiperipheral models. But the data cannot all be understood within this simple model

  17. THE CORES OF THE Fe Kα LINES IN ACTIVE GALACTIC NUCLEI: AN EXTENDED CHANDRA HIGH ENERGY GRATING SAMPLE

    International Nuclear Information System (INIS)

    Shu, X. W.; Wang, J. X.; Yaqoob, T.

    2010-01-01

    We extend the study of the core of the Fe Kα emission line at ∼6.4 keV in Seyfert galaxies reported by Yaqoob and Padmanabhan using a larger sample observed by the Chandra high-energy grating (HEG). The sample consists of 82 observations of 36 unique sources with z H 23 cm -2 ) Seyfert galaxies to date. From an empirical and uniform analysis, we present measurements of the Fe Kα line centroid energy, flux, equivalent width (EW), and intrinsic width (FWHM). The Fe Kα line is detected in 33 sources, and its centroid energy is constrained in 32 sources. In 27 sources, the statistical quality of the data is good enough to yield measurements of the FWHM. We find that the distribution in the line centroid energy is strongly peaked around the value for neutral Fe, with over 80% of the observations giving values in the range 6.38-6.43 keV. Including statistical errors, 30 out of 32 sources (∼94%) have a line centroid energy in the range 6.35-6.47 keV. The mean EW, among the observations in which a non-zero lower limit could be measured, was 53 ± 3 eV. The mean FWHM from the subsample of 27 sources was 2060 ± 230 km s -1 . The mean EW and FWHM are somewhat higher when multiple observations for a given source are averaged. From a comparison with the Hβ optical emission-line widths (or, for one source, Brα), we find that there is no universal location of the Fe Kα line-emitting region relative to the optical broad-line region (BLR). In general, a given source may have contributions to the Fe Kα line flux from parsec-scale distances from the putative black hole, down to matter a factor ∼2 closer to the black hole than the BLR. We confirm the presence of the X-ray Baldwin effect, an anti-correlation between the Fe Kα line EW and X-ray continuum luminosity. The HEG data have enabled isolation of this effect to the narrow core of the Fe Kα line.

  18. Fabrication of Core-Shell Structural SiO2@H3[PM12O40] Material and Its Catalytic Activity

    Directory of Open Access Journals (Sweden)

    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.

  19. Recent advances in platinum monolayer electrocatalysts for oxygen reduction reaction: Scale-up synthesis, structure and activity of Pt shells on Pd cores

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, K., E-mail: ksasaki@bnl.go [Brookhaven National Laboratory, Chemistry Department, Upton, NY 11973 (United States); Wang, J.X. [Brookhaven National Laboratory, Chemistry Department, Upton, NY 11973 (United States); Naohara, H. [Toyota Motor Corporation, Susono 410-1193 (Japan); Marinkovic, N. [University of Delaware, Department of Chemical Engineering, Newark, DE 19716 (United States); More, K. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Inada, H. [Hitachi High Technologies America, Pleasanton, CA 94588 (United States); Adzic, R.R., E-mail: adzic@bnl.go [Brookhaven National Laboratory, Chemistry Department, Upton, NY 11973 (United States)

    2010-03-01

    We have established a scale-up synthesis method to produce gram-quantities of Pt monolayer electrocatalysts. The core-shell structure of the Pt/Pd/C electrocatalyst has been verified using the HAADF-STEM Z-contrast images, STEM/EELS, and STEM/EDS line profile analysis. The atomic structure of this electrocatalyst and formation of a Pt monolayer on Pd nanoparticle surfaces were examined using in situ EXAFS. The Pt mass activity of the Pt/Pd/C electrocatalyst for ORR is considerably higher than that of commercial Pt/C electrocatalysts. The results with Pt monolayer electrocatalysts may significantly impact science of electrocatalysis and fuel-cell technology, as they have demonstrated an exceptionally effective way of using Pt that can resolve problems of other approaches, including electrocatalysts' inadequate activity and high Pt content.

  20. Recent advances in platinum monolayer electrocatalysts for oxygen reduction reaction: Scale-up synthesis, structure and activity of Pt shells on Pd cores

    International Nuclear Information System (INIS)

    Sasaki, K.; Wang, J.X.; Naohara, H.; Marinkovic, N.; More, K.; Inada, H.; Adzic, R.R.

    2010-01-01

    We have established a scale-up synthesis method to produce gram-quantities of Pt monolayer electrocatalysts. The core-shell structure of the Pt/Pd/C electrocatalyst has been verified using the HAADF-STEM Z-contrast images, STEM/EELS, and STEM/EDS line profile analysis. The atomic structure of this electrocatalyst and formation of a Pt monolayer on Pd nanoparticle surfaces were examined using in situ EXAFS. The Pt mass activity of the Pt/Pd/C electrocatalyst for ORR is considerably higher than that of commercial Pt/C electrocatalysts. The results with Pt monolayer electrocatalysts may significantly impact science of electrocatalysis and fuel-cell technology, as they have demonstrated an exceptionally effective way of using Pt that can resolve problems of other approaches, including electrocatalysts' inadequate activity and high Pt content.

  1. Core BPEL

    DEFF Research Database (Denmark)

    Hallwyl, Tim; Højsgaard, Espen

    The Web Services Business Process Execution Language (WS-BPEL) is a language for expressing business process behaviour based on web services. The language is intentionally not minimal but provides a rich set of constructs, allows omission of constructs by relying on defaults, and supports language......, 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...

  2. A High-Throughput Cell-Based Screen Identified a 2-[(E)-2-Phenylvinyl]-8-Quinolinol Core Structure That Activates p53.

    Science.gov (United States)

    Bechill, John; Zhong, Rong; Zhang, Chen; Solomaha, Elena; Spiotto, Michael T

    2016-01-01

    p53 function is frequently inhibited in cancer either through mutations or by increased degradation via MDM2 and/or E6AP E3-ubiquitin ligases. Most agents that restore p53 expression act by binding MDM2 or E6AP to prevent p53 degradation. However, fewer compounds directly bind to and activate p53. Here, we identified compounds that shared a core structure that bound p53, caused nuclear localization of p53 and caused cell death. To identify these compounds, we developed a novel cell-based screen to redirect p53 degradation to the Skip-Cullin-F-box (SCF) ubiquitin ligase complex in cells expressing high levels of p53. In a multiplexed assay, we coupled p53 targeted degradation with Rb1 targeted degradation in order to identify compounds that prevented p53 degradation while not inhibiting degradation through the SCF complex or other proteolytic machinery. High-throughput screening identified several leads that shared a common 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that stabilized p53. Surface plasmon resonance analysis indicated that these compounds bound p53 with a KD of 200 ± 52 nM. Furthermore, these compounds increased p53 nuclear localization and transcription of the p53 target genes PUMA, BAX, p21 and FAS in cancer cells. Although p53-null cells had a 2.5±0.5-fold greater viability compared to p53 wild type cells after treatment with core compounds, loss of p53 did not completely rescue cell viability suggesting that compounds may target both p53-dependent and p53-independent pathways to inhibit cell proliferation. Thus, we present a novel, cell-based high-throughput screen to identify a 2-[(E)-2-phenylvinyl]-8-quinolinol core structure that bound to p53 and increased p53 activity in cancer cells. These compounds may serve as anti-neoplastic agents in part by targeting p53 as well as other potential pathways.

  3. 210Po/210Pb Activity Ratios as a Possible `Dating Tool' of Ice Cores and Ice-rafted Sediments from the Western Arctic Ocean - Preliminary Results

    Science.gov (United States)

    Krupp, K.; Baskaran, M. M.

    2016-02-01

    We have collected and analyzed a suite of surface snow samples, ice cores, ice-rafted sediments (IRS) and aerosol samples from the Western Arctic for Po-210 and Pb-210 to examine the extent of disequilibrium between this pair to possibly use 210Po/210Pb activity ratio to date different layers of ice cores and time of incorporation of ice-rafted sediments into the sea ice. We have earlier reported that the activity concentrations of 210Pb in IRS vary over an order of magnitude and it is 1-2 orders of magnitude higher than that of the benthic sediments (1-2 dpm/g in benthic sediments compared to 25 to 300 dpm/g in IRS). In this study, we have measured 210Po/210Pb activity ratios in aerosols from the Arctic Ocean to constrain the initial 210Po/210Pb ratio at the time of deposition during precipitation. The 210Po activity concentration in recent snow is compared to surface ice samples. The `age' of IRS incorporation can be calculated as follows: [210Po]measured = [210Po]initial + [210Pb] (1 - exp(-λt)) (1) where λ is the decay constant of 210Po, 138.4 days, and `t' is the in-growth time period. From this equation, `t' can be calculated as follows: t = (-1/λ) [ln (1- ((210Po/210Pb)measured - (210Po/210Pb)initial)] (2) The assumption involved in this approach are: i) there is no preferential uptake of 210Po (highly biogenic - S group); and iii) both 210Po and 210Pb remain as closed system. The calculated age using equation (2) will be discussed and presented.

  4. Analytical analyses of active control of sound transmission through soft-core sandwich structures and double panel partitions

    OpenAIRE

    Sahu, Kiran Chandra

    2016-01-01

    Active structural acoustic control (ASAC) is a form of active noise control which focuses on the control of structural vibrations in a manner that minimizes acoustic radiation from a structure. The greatest difficulty ASAC suffers from is in finding an "optimal" error quantity, which can be easily implemented in a control algorithm. Volume velocity control (VVC) metric which is generally used in ASAC typically requires either a large number of sensors distributed across the entire structure, ...

  5. Synthesis of polystyrene@(silver-polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Science.gov (United States)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu

    2015-01-01

    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+ and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA)2]+) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO3 and Py, the introduction of [Ag(TEA)2]+ 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)2]+ 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 × 105 - 9×105 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.

  6. Analysis of dynamic multiplicity fluctuations at PHOBOS

    Science.gov (United States)

    Chai, Zhengwei; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J. L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2005-01-01

    This paper presents the analysis of the dynamic fluctuations in the inclusive charged particle multiplicity measured by PHOBOS for Au+Au collisions at surdsNN = 200GeV within the pseudo-rapidity range of -3 < η < 3. First the definition of the fluctuations observables used in this analysis is presented, together with the discussion of their physics meaning. Then the procedure for the extraction of dynamic fluctuations is described. Some preliminary results are included to illustrate the correlation features of the fluctuation observable. New dynamic fluctuations results will be available in a later publication.

  7. 5th International Conference on Valence Fluctuations

    CERN Document Server

    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...

  8. Fluctuations When Driving Between Nonequilibrium Steady States

    Science.gov (United States)

    Riechers, Paul M.; Crutchfield, James P.

    2017-08-01

    Maintained by environmental fluxes, biological systems are thermodynamic processes that operate far from equilibrium without detailed-balanced dynamics. Yet, they often exhibit well defined nonequilibrium steady states (NESSs). More importantly, critical thermodynamic functionality arises directly from transitions among their NESSs, driven by environmental switching. Here, we identify the constraints on excess heat and dissipated work necessary to control a system that is kept far from equilibrium by background, uncontrolled "housekeeping" forces. We do this by extending the Crooks fluctuation theorem to transitions among NESSs, without invoking an unphysical dual dynamics. This and corresponding integral fluctuation theorems determine how much work must be expended when controlling systems maintained far from equilibrium. This generalizes thermodynamic feedback control theory, showing that Maxwellian Demons can leverage mesoscopic-state information to take advantage of the excess energetics in NESS transitions. We also generalize an approach recently used to determine the work dissipated when driving between functionally relevant configurations of an active energy-consuming complex system. Altogether, these results highlight universal thermodynamic laws that apply to the accessible degrees of freedom within the effective dynamic at any emergent level of hierarchical organization. By way of illustration, we analyze a voltage-gated sodium ion channel whose molecular conformational dynamics play a critical functional role in propagating action potentials in mammalian neuronal membranes.

  9. Noise and fluctuations an introduction

    CERN Document Server

    MacDonald, D K C

    2006-01-01

    An understanding of fluctuations and their role is both useful and fundamental to the study of physics. This concise study of random processes offers graduate students and research physicists a survey that encompasses both the relationship of Brownian Movement with statistical mechanics and the problem of irreversible processes. It outlines the basics of the physics involved, without the strictures of mathematical rigor.The three-part treatment starts with a general survey of Brownian Movement, including electrical Brownian Movement and ""shot-noise,"" Part two explores correlation, frequency

  10. Electrostatic fluctuations in soap films

    International Nuclear Information System (INIS)

    Dean, D.S.; Horgan, R.R.

    2002-01-01

    A field theory to describe electrostatic interactions in soap films, described by electric multilayers with a generalized thermodynamic surface-charging mechanism, is studied. In the limit where the electrostatic interactions are weak, this theory is exactly soluble. The theory incorporates in a consistent way, the surface-charging mechanism and the fluctuations in the electrostatic field that correspond to the zero-frequency component of the van der Waals force. It is shown that these terms lead to a Casimir-like attraction that can be sufficiently large to explain the transition between the common black film to a Newton black film

  11. Chaotic fluctuations in mathematical economics

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Hiroyuki, E-mail: yoshida.hiroyuki@nihon-u.ac.jp [College of Economics, Nihon University, Chiyoda-ku, Tokyo 101-8360 (Japan)

    2011-03-01

    In this paper we examine a Cournot duopoly model, which expresses the strategic interaction between two firms. We formulate the dynamic adjustment process and investigate the dynamic properties of the stationary point. By introducing a memory mechanism characterized by distributed lag functions, we presuppose that each firm makes production decisions in a cautious manner. This implies that we have to deal with the system of integro-differential equations. By means of numerical simulations we show the occurrence of chaotic fluctuations in the case of fixed delays.

  12. SU-F-T-237: The Imaging and Radiation Oncology Core (IROC) Cooperatives Activities Supporting the NCI’s National Clinical Trial Network

    Energy Technology Data Exchange (ETDEWEB)

    Followill, D [UT MD Anderson Cancer Center, Houston, TX (United States); Galvin, J [Thomas Jefferson University Hospital, Newtown, PA (United States); Michalski, J [Washington University in St. Louis, St. Louis, MO (United States); Rosen, M [University of Pennsylvania Medical Center, Philadelphia, PA (United States); FitzGerald, T [University of Massachusetts Medical School, Lincoln, RI (United States); Knopp, M [The Ohio State University, Columbus, OH (United States)

    2016-06-15

    Purpose: The Imaging and Radiation Oncology Core (IROC) Cooperative has been active for the past two years supporting the National Clinical Trial Network and the details of that support are reported. Methods: There are six QA centers (Houston, Ohio, Philadelphia-RT, Philadelphia-DI, Rhode Island, St. Louis) providing an integrated RT and DI quality control program in support of the NCI’s clinical trials. The QA Center’s efforts are focused on assuring high quality data for clinical trials designed to improve the clinical outcomes for cancer patients worldwide. This program is administered through five core services: site qualification, trial design support, credentialing, data management, and case review. Results: IROC currently provides core support for 172 NCTN trials with RT, DI and RT/DI components. Many of these trials were legacy trial from the previous cooperative group program. IROC monitors nearly 1800 RT photon and 20 proton institutions. Over 28,000 beams outputs were monitored with 8% of the sites requiring repeat audits due to beam out of criteria. As part of credentialing, 950 QA phantoms have been irradiated, 515 imaging modalities evaluated and almost 4000 credentialing letters have been issued. In just year 2, 5290 RT and 4934 DI patient datasets were received (many using TRIAD) by IROC QA Centers to be prepared for review. During the past 2 years, a total of 6300 RT cases and 19,000 DI image sets were reviewed by IROC technical staff. To date, IROC has published 36 manuscripts. Conclusion: The QA services provided by IROC are numerous and are continually being evaluated for effectiveness, harmonized across all NCTN Groups and administered in an efficient and timely manner to enhance accurate and per protocol trial data submission. These efforts increase each NCTN Group’s ability to derive meaningful outcomes from their clinical trials. This work was supported by DHHS NIH grant 5U24CA180803.

  13. Stronger enhancer II/core promoter activities of hepatitis B virus isolates of B2 subgenotype than those of C2 subgenotype.

    Science.gov (United States)

    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.

  14. Alfvénic fluctuations in "newborn"' polar solar wind

    Directory of Open Access Journals (Sweden)

    B. Bavassano

    2005-06-01

    Full Text Available The 3-D structure of the solar wind is strongly dependent upon the Sun's activity cycle. At low solar activity a bimodal structure is dominant, with a fast and uniform flow at the high latitudes, and slow and variable flows at low latitudes. Around solar maximum, in sharp contrast, variable flows are observed at all latitudes. This last kind of pattern, however, is a relatively short-lived feature, and quite soon after solar maximum the polar wind tends to regain its role. The plasma parameter distributions for these newborn polar flows appear very similar to those typically observed in polar wind at low solar activity. The point addressed here is about polar wind fluctuations. As is well known, the low-solar-activity polar wind is characterized by a strong flow of Alfvénic fluctuations. Does this hold for the new polar flows too? An answer to this question is given here through a comparative statistical analysis on parameters such as total energy, cross helicity, and residual energy, that are of general use to describe the Alfvénic character of fluctuations. Our results indicate that the main features of the Alfvénic fluctuations observed in low-solar-activity polar wind have been quickly recovered in the new polar flows developed shortly after solar maximum. Keywords. Interplanetary physics (MHD waves and turbulence; Sources of the solar wind – Space plasma physics (Turbulence

  15. Spatial distribution of the neutron flux in the IEA-R1 reactor core obtained by means of foil activation

    International Nuclear Information System (INIS)

    Mestnik Filho, J.

    1979-01-01

    A three-dimensional distribution of the neutron flux in IEA-R1 reactor, obtained by activating gold foils, is presented. The foils of diameter 8mm and thickness 0,013mm were mounted on lucite plates and located between the fuel element plates. Foil activities were measured using a 3x3 inches Nal(Tl) scintilation detector calibrated against a 4πβγ coincidence detector. Foil positions were chosen to minimize the errors of measurement; the overall estimated error on the measured flux is 5%. (Author) [pt

  16. Using a Time-Driven Activity-Based Costing Model To Determine the Actual Cost of Services Provided by a Transgenic Core.

    Science.gov (United States)

    Gerwin, Philip M; Norinsky, Rada M; Tolwani, Ravi J

    2018-03-01

    Laboratory animal programs and core laboratories often set service rates based on cost estimates. However, actual costs may be unknown, and service rates may not reflect the actual cost of services. Accurately evaluating the actual costs of services can be challenging and time-consuming. We used a time-driven activity-based costing (ABC) model to determine the cost of services provided by a resource laboratory at our institution. The time-driven approach is a more efficient approach to calculating costs than using a traditional ABC model. We calculated only 2 parameters: the time required to perform an activity and the unit cost of the activity based on employee cost. This method allowed us to rapidly and accurately calculate the actual cost of services provided, including microinjection of a DNA construct, microinjection of embryonic stem cells, embryo transfer, and in vitro fertilization. We successfully implemented a time-driven ABC model to evaluate the cost of these services and the capacity of labor used to deliver them. We determined how actual costs compared with current service rates. In addition, we determined that the labor supplied to conduct all services (10,645 min/wk) exceeded the practical labor capacity (8400 min/wk), indicating that the laboratory team was highly efficient and that additional labor capacity was needed to prevent overloading of the current team. Importantly, this time-driven ABC approach allowed us to establish a baseline model that can easily be updated to reflect operational changes or changes in labor costs. We demonstrated that a time-driven ABC model is a powerful management tool that can be applied to other core facilities as well as to entire animal programs, providing valuable information that can be used to set rates based on the actual cost of services and to improve operating efficiency.

  17. Characteristics of the co-fluctuation matrix transmission network based on financial multi-time series

    OpenAIRE

    Huajiao Li; Haizhong An; Xiangyun Gao; Wei Fang

    2015-01-01

    The co-fluctuation of two time series has often been studied by analysing the correlation coefficient over a selected period. However, in both domestic and global financial markets, there are more than two active time series that fluctuate constantly as a result of various factors, including geographic locations, information communications and so on. In addition to correlation relationships over longer periods, daily co-fluctuation relationships and their transmission features are also import...

  18. N-Acylated and d Enantiomer Derivatives of a Nonamer Core Peptide of Lactoferricin B Showing Improved Antimicrobial Activity

    OpenAIRE

    Wakabayashi, Hiroyuki; Matsumoto, Hiroshi; Hashimoto, Koichi; Teraguchi, Susumu; Takase, Mitsunori; Hayasawa, Hirotoshi

    1999-01-01

    N-acylated or d enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

  19. N-Acylated and D enantiomer derivatives of a nonamer core peptide of lactoferricin B showing improved antimicrobial activity.

    Science.gov (United States)

    Wakabayashi, H; Matsumoto, H; Hashimoto, K; Teraguchi, S; Takase, M; Hayasawa, H

    1999-05-01

    N-acylated or D enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

  20. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    International Nuclear Information System (INIS)

    Guo, Longhai; Ren, Shanshan; Qiu, Teng; Wang, Leilei; Zhang, Jiangru; He, Lifan; Li, Xiaoyu

    2015-01-01

    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 + and Py monomer and to avoid the accumulation of these AgNPs during synthesis process, the complexation of triethanolamine (TEA) and silver ion ([Ag(TEA) 2 ] + ) was employed as the oxidant, so that the generation rate of AgNPs was in turn decreased. Moreover, compared with the redox reaction between AgNO 3 and Py, the introduction of [Ag(TEA) 2 ] + 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) 2 ] + 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 5  – 9×10 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

  1. Synthesis of polystyrene@(silver–polypyrrole) core/shell nanocomposite microspheres and study on their antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Currency speculation and dollar fluctuations

    Directory of Open Access Journals (Sweden)

    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.

  3. Entropic fluctuations in DNA sequences

    Science.gov (United States)

    Thanos, Dimitrios; Li, Wentian; Provata, Astero

    2018-03-01

    The Local Shannon Entropy (LSE) in blocks is used as a complexity measure to study the information fluctuations along DNA sequences. The LSE of a DNA block maps the local base arrangement information to a single numerical value. It is shown that despite this reduction of information, LSE allows to extract meaningful information related to the detection of repetitive sequences in whole chromosomes and is useful in finding evolutionary differences between organisms. More specifically, large regions of tandem repeats, such as centromeres, can be detected based on their low LSE fluctuations along the chromosome. Furthermore, an empirical investigation of the appropriate block sizes is provided and the relationship of LSE properties with the structure of the underlying repetitive units is revealed by using both computational and mathematical methods. Sequence similarity between the genomic DNA of closely related species also leads to similar LSE values at the orthologous regions. As an application, the LSE covariance function is used to measure the evolutionary distance between several primate genomes.

  4. Universal bounds on current fluctuations.

    Science.gov (United States)

    Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

    2016-05-01

    For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

  5. Plutonium activities and 240Pu/ 239Pu atom ratios in sediment cores from the east China sea and Okinawa Trough: Sources and inventories

    Science.gov (United States)

    Wang, Zhong-liang; Yamada, Masatoshi

    2005-05-01

    Plutonium concentrations and 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry after separation using ion-exchange chromatography. The results showed that 240Pu/ 239Pu atom ratios in the East China Sea and Okinawa Trough sediments, ranging from 0.21 to 0.33, were much higher than the reported value of global fallout (0.18). The highest 240Pu/ 239Pu ratios (0.32-0.33) were observed in the deepest Okinawa Trough sediment samples. These ratios suggested the US nuclear weapons tests in the early 1950s at the Pacific Proving Grounds in the Marshall Islands were a major source of plutonium in the East China Sea and Okinawa Trough sediments, in addition to the global fallout source. It was proposed that close-in fallout plutonium was delivered from the Pacific Proving Grounds test sites via early direct tropospheric fallout and transportation by the North Pacific Equatorial Circulation system and Kuroshio Current into the Okinawa Trough and East China Sea. The total 239 + 240 Pu inventories in the cores were about 150-200% of that expected from direct global fallout; about 46-67% of the total inventories were delivered from the Pacific Proving Grounds. Much higher 239 + 240 Pu inventories were observed in the East China Sea sediments than in sediments of the Okinawa Trough, because in the open oceans, part of the 239 + 240 Pu was still retained in the water column, and continued Pu scavenging was higher over the margin than the trough. According to the vertical distributions of 239 + 240 Pu activities and 240Pu/ 239Pu atom ratios in these cores, it was concluded that sediment mixing was the dominant process in controlling profiles of plutonium in this area. Faster mixing in the coastal samples has homogenized the entire 240Pu/ 239Pu ratio record today; slightly slower mixing and less scavenging in the Okinawa Trough have left the surface sediment ratios closer

  6. Transport barrier fluctuations governed by SOL turbulence spreading

    International Nuclear Information System (INIS)

    Ghendrih, Ph.; Sarazin, Y.; Ciraolo, G.; Darmet, G.; Garbet, X.; Grangirard, V.; Tamain, P.; Benkadda, S.; Beyer, P.

    2007-01-01

    Turbulence spreading, namely turbulent transport extending into a stable region is reported both for the flat density profiles in the far SOL and into a modeled H-mode barrier. It is shown that due to turbulence penetration, the pedestal width fluctuates and that its effective width is a factor 2 smaller than the linear predicted width. Turbulence overshooting throughout the pedestal leads to a non-vanishing turbulent transport within the barrier and provides a coupling of core and SOL turbulence despite the transport barrier

  7. AJUBA LIM Proteins Limit Hippo Activity in Proliferating Cells by Sequestering the Hippo Core Kinase Complex in the Cytosol.

    Science.gov (United States)

    Jagannathan, Radhika; Schimizzi, Gregory V; Zhang, Kun; Loza, Andrew J; Yabuta, Norikazu; Nojima, Hitoshi; Longmore, Gregory D

    2016-10-15

    The Hippo pathway controls organ growth and is implicated in cancer development. Whether and how Hippo pathway activity is limited to sustain or initiate cell growth when needed is not understood. The members of the AJUBA family of LIM proteins are negative regulators of the Hippo pathway. In mammalian epithelial cells, we found that AJUBA LIM proteins limit Hippo regulation of YAP, in proliferating cells only, by sequestering a cytosolic Hippo kinase complex in which LATS kinase is inhibited. At the plasma membranes of growth-arrested cells, AJUBA LIM proteins do not inhibit or associate with the Hippo kinase complex. The ability of AJUBA LIM proteins to inhibit YAP regulation by Hippo and to associate with the kinase complex directly correlate with their capacity to limit Hippo signaling during Drosophila wing development. AJUBA LIM proteins did not influence YAP activity in response to cell-extrinsic or cell-intrinsic mechanical signals. Thus, AJUBA LIM proteins limit Hippo pathway activity in contexts where cell proliferation is needed. Copyright © 2016 Jagannathan et al.

  8. Prediction of propeller-induced hull-pressure fluctuations

    NARCIS (Netherlands)

    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

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

    KAUST Repository

    Yuan, Qiang; Huang, Dabing; Wang, Honghui; Zhou, Zhiyou; Wang, Qingxiao

    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

  10. Sampling rare fluctuations of discrete-time Markov chains

    Science.gov (United States)

    Whitelam, Stephen

    2018-03-01

    We describe a simple method that can be used to sample the rare fluctuations of discrete-time Markov chains. We focus on the case of Markov chains with well-defined steady-state measures, and derive expressions for the large-deviation rate functions (and upper bounds on such functions) for dynamical quantities extensive in the length of the Markov chain. We illustrate the method using a series of simple examples, and use it to study the fluctuations of a lattice-based model of active matter that can undergo motility-induced phase separation.

  11. A multi-proxy lake core record from Lago Lungo, Rieti Basin, Lazio, Italy and its relation to human activities in the catchment during the last century

    Science.gov (United States)

    Noble, Paula; Tunno, Irene; Mensing, Scott; Piovesan, Gianluca

    2016-04-01

    The lakes of the Rieti Basin have experienced extensive human modification dating back to pre-Roman times, yet lake archives indicate that the most profound changes to the aquatic ecosystem have occurred during the last century. Analysis of the upper ˜120 cm segment of a sediment core from Lago Lungo, dating back to ˜1830 CE, show changes in water quality and hydrologic inflow largely attributed to 20th century reclamation and land use activities. Lago Lungo is a shallow, small, eutrophic, hard water lake situated in an intermontaine alluvial plain ˜90 km NE of Rome. It is one of several remnant lakes in a poorly drained wetland area fed by numerous springs. Reclamation activities over the last century have substantially altered the drainage network affecting water delivery to the lakes and their connectivity. There are 3 interesting signals in the core. First, small Stephanodiscus species, associated with hypereutrophic conditions, appear after 1950, peak ˜1990, and may be attributed to increased use of chemical fertilizers and intensification of local agriculture. Elemental proxies from scanning XRF data (abundances of Ti, Si/Ti, and Ca) are consistent with increased eutrophication starting ˜1950. A decline in Stephanodicsus after 1990 reflects some improvement to the water quality following the lake's incorporation into a nature preserve and creation of a narrow vegetation buffer. Intermittent water quality measurements from 1982 onward corroborate the changes in trophic status interpreted from the core record. Second, a large change in the core stratigraphy, elemental geochemistry, and diatom composition occurs ˜1940 and is associated with several major reclamation efforts, including the rerouting of the Santa Susanna channel, which redirected large volumes of artesian inflows away from the lakes and estuarine system. Upstream, dams on the Turano and Salto rivers were also constructed, further affecting hydrological inflows into the basin. From ˜1900

  12. Reactor core of FBR type reactor

    International Nuclear Information System (INIS)

    Hayashi, Hideyuki; Ichimiya, Masakazu.

    1994-01-01

    A reactor core is a homogeneous reactor core divided into two regions of an inner reactor core region at the center and an outer reactor core region surrounding the outside of the inner reactor core region. In this case, the inner reactor core region has a lower plutonium enrichment degree and less amount of neutron leakage in the radial direction, and the outer reactor core region has higher plutonium enrichment degree and greater amount of neutron leakage in the radial direction. Moderator materials containing hydrogen are added only to the inner reactor core fuels in the inner reactor core region. Pins loaded with the fuels with addition of the moderator materials are inserted at a ratio of from 3 to 10% of the total number of the fuel pins. The moderator materials containing hydrogen comprise zirconium hydride, titanium hydride, or calcium hydride. With such a constitution, fluctuation of the power distribution in the radial direction along with burning is suppressed. In addition, an absolute value of the Doppler coefficient can be increased, and a temperature coefficient of coolants can be reduced. (I.N.)

  13. Hydrodynamical fluctuations in smooth shear flows

    International Nuclear Information System (INIS)

    Chagelishvili, G.D.; Khujadze, G.R.; Lominadze, J.G.

    1999-11-01

    Background of hydrodynamical fluctuations in a intrinsically/stochastically forced, laminar, uniform shear flow is studied. The employment of so-called nonmodal mathematical analysis makes it possible to represent the background of fluctuations in a new light and to get more insight into the physics of its formation. The basic physical processes responsible for the formation of vortex and acoustic wave fluctuation backgrounds are analyzed. Interplay of the processes at low and moderate shear rates is described. Three-dimensional vortex fluctuations around a given macroscopic state are numerically calculated. The correlation functions of the fluctuations of physical quantities are analyzed. It is shown that there exists subspace D k in the wave-number space (k-space) that is limited externally by spherical surface with radius k ν ≡ A/ν (where A is the velocity shear parameter, ν - the kinematic viscosity) in the nonequilibrium open system under study. The spatial Fourier harmonics of vortex as well as acoustic wave fluctuations are strongly subjected by flow shear (by the open character of the system) at wave-numbers satisfying the condition k ν . Specifically it is shown that in D k : The fluctuations are non-Markovian; the spatial spectral density of energy of the vortex fluctuations by far exceeds the white-noise; the term of a new type associated to the hydrodynamical fluctuation of velocity appears in the correlation function of pressure; the fluctuation background of the acoustic waves is completely different at low and moderate shear rates (at low shear rates it is reduced in D k in comparison to the uniform (non-shear) flow; at moderate shear rates it it comparable to the background of the vortex fluctuations). The fluctuation background of both the vortex and the acoustic wave modes is anisotropic. The possible significance of the fluctuation background of vortices for the subcritical transition to turbulence and Brownian motion of small macroscopic

  14. Voltage fluctuations in neurons: signal or noise?

    DEFF Research Database (Denmark)

    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......Noise and variability are fundamental companions to ion channels and synapses and thus inescapable elements of brain function. The overriding unresolved issue is to what extent noise distorts and limits signaling on one hand and at the same time constitutes a crucial and fundamental enrichment...... 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...

  15. Influence Of Tools Input/Output Requirements On Managers Core Front End Activities In New Product Development

    DEFF Research Database (Denmark)

    Appio, Francesco P.; Achiche, Sofiane; Minin, Alberto Di

    2011-01-01

    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......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...

  16. Perturbative analysis of transport and fluctuation studies on RFX

    International Nuclear Information System (INIS)

    Martini, S.

    2002-01-01

    On the RFX reversed field pinch different transport mechanisms govern the centre and the edge of the plasma. Core transport is driven by parallel transport in a stochastic magnetic field, giving rise to an outward directed particle convection velocity. At the edge, roughly corresponding to the region outside the toroidal field reversal surface (where q=0), electrostatic fluctuations are an important loss channel, but more than 50% of the power losses have been associated to localized plasma-wall interaction due to the non-axisymmetric magnetic perturbations caused by locked modes. In the paper we present the most recent progress made in the modeling and understanding of the above mechanisms underlying particle and energy transport. The paper also discusses the correlations between core and edge transport phenomena. The main tools are perturbative transport studies by pellet injection and the analysis of the contribution of intermittency processes to particle transport in the edge. (author)

  17. Neutron fluctuations a treatise on the physics of branching processes

    CERN Document Server

    Pazsit, Imre; Pzsit, Imre

    2007-01-01

    The transport of neutrons in a multiplying system is an area of branching processes with a clear formalism. This book presents an account of the mathematical tools used in describing branching processes, which are then used to derive a large number of properties of the neutron distribution in multiplying systems with or without an external source. In the second part of the book, the theory is applied to the description of the neutron fluctuations in nuclear reactor cores as well as in small samples of fissile material. The question of how to extract information about the system under study is discussed. In particular the measurement of the reactivity of subcritical cores, driven with various Poisson and non-Poisson (pulsed) sources, and the identification of fissile material samples, is illustrated. The book gives pragmatic information for those planning and executing and evaluating experiments on such systems. - Gives a complete treatise of the mathematics of branching particle processes, and in particular n...

  18. Fluctuating hyperfine interactions: computational implementation

    International Nuclear Information System (INIS)

    Zacate, M. O.; Evenson, W. E.

    2010-01-01

    A library of computational routines has been created to assist in the analysis of stochastic models of hyperfine interactions. We call this library the stochastic hyperfine interactions modeling library (SHIML). It provides routines written in the C programming language that (1) read a text description of a model for fluctuating hyperfine fields, (2) set up the Blume matrix, upon which the evolution operator of the system depends, and (3) find the eigenvalues and eigenvectors of the Blume matrix so that theoretical spectra of experimental hyperfine interaction measurements can be calculated. Example model calculations are included in the SHIML package to illustrate its use and to generate perturbed angular correlation spectra for the special case of polycrystalline samples when anisotropy terms of higher order than A 22 can be neglected.

  19. INFERENCE OF HEATING PROPERTIES FROM “HOT” NON-FLARING PLASMAS IN ACTIVE REGION CORES. I. SINGLE NANOFLARES

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, W. T.; Bradshaw, S. J. [Department of Physics and Astronomy, Rice University, Houston, TX 77251-1892 (United States); Cargill, P. J., E-mail: will.t.barnes@rice.edu [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)

    2016-09-20

    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 10{sup 6.6} and 10{sup 7} K. Signatures of the actual heating may be detectable in some instances.

  20. Interplanetary Alfvenic fluctuations: A stochastic model

    International Nuclear Information System (INIS)

    Barnes, A.

    1981-01-01

    The strong alignment of the average directions of minimum magnetic variance and mean magnetic field in interplanetary Alfvenic fluctuations is inconsistent with the usual wave-propagation models. We investigate the concept of minimum variance for nonplanar Alfvenic fluctuations in which the field direction varies stochastically. It is found that the tendency of the minimum variance and mean field directions to be aligned may be purely a consequence of the randomness of the field direction. In particular, a well-defined direction of minimum variance does not imply that the fluctuations are necessarily planar. The fluctuation power spectrum is a power law for frequencies much higher than the inverse of the correlation time. The probability distribution of directions a randomly fluctuating field of constant magnitude is calculated. A new approach for observational studies of interplanetary fluctuations is suggested

  1. Vessel size effect on the characteristic frequency of the free surface fluctuations

    International Nuclear Information System (INIS)

    Nam, Ho Yun; Kim, Min Joon; Kim, Jong Man; Choi, Byoung Hae

    2004-01-01

    Studies of the free surface fluctuations is one of the important topics in a liquid metal nuclear reactor using sodium as the coolant that has a free surface in the upper plenum of the reactor vessel. The main reasons for the study on the free surface fluctuations can be summarized as: 1. to secure the structural integrity of a reactor vessel by considering the thermal stress on the vessel wall induced by the fluctuations of the free surface between the hot sodium and cold cover gas, 2. to prevent the cover gas entrainment at the free surface of the sodium because the entrained gas causes a change in the reactivity and also reduces the heat removal capability in the core. Some experimental studies on the free surface fluctuations have been reported. However, most of them focus on the gas entrainment phenomena and only a few works concern the basic characteristics of the free surface fluctuations. Since the thermal stress on the wall is strongly dependent on the amplitude and frequency of the free surface fluctuations, studies on the amplitudes and frequencies should receive more attention. In Nam, empirical formulae on the amplitudes and frequencies with respect to the geometric and hydraulic parameters were introduced. It is an interesting result, but the experiment was performed within the parameter range near the onset point of the fluctuations. In the real reactor condition, larger sized fluctuations may exist and the formula needs to be modified. In this study, we performed experiments on the free surface fluctuations, especially on larger sized fluctuations and made an analysis of the amplitudes and frequencies. The main focus of this paper is the effect of the vessel size on the characteristic frequencies. It is thought to be helpful for finding the scaling laws, for example, designing a scale-down experiment

  2. MULTIFRACTAL SOLAR EUV INTENSITY FLUCTUATIONS AND THEIR IMPLICATIONS FOR CORONAL HEATING MODELS

    Energy Technology Data Exchange (ETDEWEB)

    Cadavid, A. C.; Lawrence, J. K.; Christian, D. J. [Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Rivera, Y. J. [Department of Climate and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109-2143 (United States); Jennings, P. J. [5174 S. Slauson Avenue, Culver City, CA 90230 (United States); Rappazzo, A. F., E-mail: ana.cadavid@csun.edu [Department of Earth, Planetary and Space Sciences, University of California Los Angeles, Los Angeles, CA 90095 (United States)

    2016-11-10

    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.

  3. Charge Fluctuations of an Uncharged Black Hole

    OpenAIRE

    Schiffer, Marcelo

    2016-01-01

    In this paper we calculate charge fluctuations of a Schwarzschild black-hole of mass $M$ confined within a perfectly reflecting cavity of radius R in thermal equilibrium with various species of radiation and fermions . Charge conservation is constrained by a Lagrange multiplier (the chemical potential). Black hole charge fluctuations are expected owing to continuous absorption and emission of particles by the black hole. For black holes much more massive than $10^{16} g$ , these fluctuations ...

  4. Diurnal changes in core body temperature, day/night locomotor activity patterns, and actigraphy-generated behavioral sleep in aged canines with varying levels of cognitive dysfunction

    Directory of Open Access Journals (Sweden)

    Brian M. Zanghi

    2016-10-01

    Full Text Available Core body temperature (CBT rhythm, locomotor activity, and actigraphy-sleep were evaluated in geriatric dogs with cognitive dysfunction. Dogs (n=33; 9–16 yrs performed a spatial working memory task and divided into three memory groups: Low, Moderate, and High, with subsequent evaluation of learning and attention. Rectal CBT was recorded 6 times over a 17.5 h period and Actiwatch® activity monitoring system for 5 days while housed indoors with 12 h light/dark schedule. Rhythm of daily activity data was evaluated using the traditional cosinor analysis and generation of non-parametric measures of interdaily stability, intradaily variability, and relative amplitude. CBT differed with time (F (5, 130=11.36, p<0.001, and was the highest at 19:00C. CBT at 19:00 was positively related (p<0.01 to memory (r(31=0.50 and 3-domain cognitive performance index (memory, learning, attention; r(31=0.39. Total daytime or night-time activity did not differ between memory groups, but hourly counts at 8:00 were positively related (p<0.05 to memory (r(31=0.52, learning (r(31=0.36, and 3-domain cognitive performance index (r(31=0.53. There were no significant differences between age or memory groups for any circadian rhythm measures. Daytime naps were inversely related to memory accuracy (r(31=−0.39; p<0.05 and BT at 15:00 (r(30=−0.51; p<0.01. Lower peak BT and increased napping may predict some aspects of cognitive performance of working memory, learning, and/or attention processes in these geriatric dogs, but minimal diurnal rhythm disruption of locomotor activity is observed when these cognitive processes decline.

  5. Geomorphic response of an active metamorphic core-complex in a collisional orogen: Example from the Lunggar Shan, Southern Tibet

    International Nuclear Information System (INIS)

    Taylor, M H; Stockli, D F; Kapp, P A

    2008-01-01

    We present structural and neotectonic mapping from the Lunggar Shan rift in southern Tibet. The Lunggar Shan is a N-trending mountain range ∼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 ( 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 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

  6. Fluctuations in Cytosolic Calcium Regulate the Neuronal Malate-Aspartate NADH Shuttle

    DEFF Research Database (Denmark)

    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...

  7. Temperature fluctuation reducing device for FBR type reactor

    International Nuclear Information System (INIS)

    Ootsuka, Fumio; Shiratori, Fumihiro.

    1991-01-01

    In existent FBR type reactors, since temperature fluctuation in the reactor upper portion has been inevitable, thermal fatigue may be caused possibly in reactor core upper mechanisms. Then, a valve is disposed to a control rod lower guide tube contained in a reactor container for automatically controlling the amount of passing coolants in accordance with the temperature of the passing coolants, to mix and control coolants passing through a fuel assembly in adjacent with the guide tube and coolants passing through the guide tube. Further, a rectification cylinder is disposed, in which a portion of coolants passing through the fuel assembly is caused to flow. An orifice is disposed to the cylinder with an exit being disposed to the upstream thereof such that the coolants not flown into the rectification cylinder and the coolants passing through the guide tube are mixed to moderate the temperature fluctuation. That is, a portion of the coolants flown into the rectification cylinder can not pass through the orifice, but flow backwardly to the upstream and is discharged out of the rectification cylinder from the coolants exit and mixed sufficiently with coolants passing through the guide tube. In this way, temperature fluctuation can be moderated. (N.H.)

  8. Wind fluctuations over the North Sea

    DEFF Research Database (Denmark)

    Vincent, Claire Louise; Pinson, Pierre; Giebel, Gregor

    2011-01-01

    Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms. The Hil......Climatological patterns in wind speed fluctuations with periods of 1 min to 10 h are analysed using data from a meteorological mast in the Danish North Sea. Fluctuations on these time scales are of particular relevance to the effective management of the power supply from large wind farms...

  9. Neutrino propagation in a fluctuating sun

    International Nuclear Information System (INIS)

    Burgess, C.P.; Michaud, D.

    1997-01-01

    We adapt to neutrino physics a general formulation for particle propagation in fluctuating media, initially developed for applications to electromagnetism and neutron optics. In leading approximation this formalism leads to the usual MSW effective Hamiltonian governing neutrino propagation through a medium. Next-to-leading contributions describe deviations from this description, which arise due to neutrino interactions with fluctuations in the medium. We compute these corrections for two types of fluctuations: (i) microscopic thermal fluctuations and (ii) macroscopic fluctuations in the medium s density. While the first of these reproduces standard estimates, which are negligible for applications to solar neutrinos, we find that the second can be quite large, since it grows in size with the correlation length of the fluctuation. We consider two models in some detail. For fluctuations whose correlations extend only over a local region in space of length l, appreciable effects for MSW oscillations arise if (δn/n) 2 l approx-gt 100m or so. Alternatively, a crude model of helioseismic p-waves gives appreciable effects only when (δn/n)approx-gt 1%. In general the dominant effect is to diminish the quality of the resonance, making the suppression of the 7 Be neutrinos a good experimental probe of fluctuations deep within the sun. Fluctuations can also provide a new mechanism for reducing the solar neutrino flux, giving an energy-independent suppression factor of 1/2 away from the resonant region, even for small vacuum mixing angles. copyright 1997 Academic Press, Inc

  10. Non-Gaussian conductivity fluctuations in semiconductors

    International Nuclear Information System (INIS)

    Melkonyan, S.V.

    2010-01-01

    A theoretical study is presented on the statistical properties of conductivity fluctuations caused by concentration and mobility fluctuations of the current carriers. It is established that mobility fluctuations result from random deviations in the thermal equilibrium distribution of the carriers. It is shown that mobility fluctuations have generation-recombination and shot components which do not satisfy the requirements of the central limit theorem, in contrast to the current carrier's concentration fluctuation and intraband component of the mobility fluctuation. It is shown that in general the mobility fluctuation consist of thermal (or intraband) Gaussian and non-thermal (or generation-recombination, shot, etc.) non-Gaussian components. The analyses of theoretical results and experimental data from literature show that the statistical properties of mobility fluctuation and of 1/f-noise fully coincide. The deviation from Gaussian statistics of the mobility or 1/f fluctuations goes hand in hand with the magnitude of non-thermal noise (generation-recombination, shot, burst, pulse noises, etc.).

  11. Catalytic activity of tungsten carbide-carbon (WC@C) core-shell structured for ethanol electro-oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Singla, Gourav, E-mail: gsinghla@gmail.com; Singh, K., E-mail: kusingh@thapar.edu; Pandey, O.P., E-mail: oppandey@thapar.edu

    2017-01-15

    In this study, carbon coated WC (WC@C) was synthesized through solvothermal reactions in the presence of reducing agent magnesium (Mg) by employing tungsten oxide (WO{sub 3}) as a precursor, acetone (C{sub 3}H{sub 6}O) as a carbon source. The formation of WC@C nano particles is confirmed by X-ray diffraction and Transmission electron microscopy. The thermal stability of the synthesized powder examined in air shows its stability up to 550 °C. In this method, in-situ produced outer carbon layer increase the surface area of materials which is 52.6 m{sup 2} g{sup −1} with pore volume 0.213 cm{sup 3} g{sup −1}. The Electrocatalytic activity of ethanol oxidation on a synthesized sample with and without Pt nano particles have been investigated using cyclic voltammetry (CV). The CV results show the enhancement in oxidation stability of WC@C in acidic media as well as better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles as compared to without Pt nano particles. - Highlights: • Tungsten carbide nano powder was synthesized using acetone as carbon source. • In-situ produced outer carbon layer increase the surface area of materials. • Mesoporous WC with surface areas 52.6 m{sup 2}/g obtained. • Pt modified WC powder showed higher electrochemical stability. • Better CO-tolerance for ethanol oxidation after the deposition of Pt nanoparticles.

  12. Geomagnetic fluctuations during a polarity transition

    Science.gov (United States)

    Audunsson, Haraldur; Levi, Shaul

    1997-01-01

    The extensive Roza Member of the Columbia River Basalt Group (Washington State) has intermediate paleomagnetic directions, bracketed by underlying normal and overlying reverse polarity flows. A consistent paleomagnetic direction was measured at 11 widely distributed outcrops; the average direction has a declination of 189° and an inclination of -5°, with greater variation in the inclination [Rietman, 1966]. In this study the Roza Member was sampled in two Pasco Basin drillcores, where it is a single cooling unit and its thickness exceeds 50 m. Excellent core recovery allowed uniform and dense sampling of the drillcores. During its protracted cooling, the Roza flow in the drillcores recorded part of a 15.5 Ma geomagnetic polarity transition. The inclination has symmetric, quasicyclic intraflow variation, while the declination is nearly constant, consistent with the results from the outcrops. Thermal models of the cooling flow provide the timing for remanence acquisition. The inclination is inferred to have progressed from 0° to -15° and back to -3°over a period of 15 to 60 years, at rates of 1.6° to 0.5°/yr. Because the geomagnetic intensity was probably weak during the transition, these apparently high rates of change are not significantly different from present-day secular variation. These results agree with the hypothesis that normal secular variation persists through geomagnetic transitions. The Iow-amplitude quasicyclical fluctuations of the field over tens of years, recorded by Roza, suggest that the geomagnetic field reverses in discrete steps, and that more than 15-60 years were required to complete this reversal.

  13. Seed-mediated photodeposition route to Ag-decorated SiO2@TiO2 microspheres with ideal core-shell structure and enhanced photocatalytic activity

    Science.gov (United States)

    Ma, Jianqi; Guo, Xiaohua; Ge, Hongguang; Tian, Guanghui; Zhang, Qiang

    2018-03-01

    Ag-decorated SiO2@TiO2 microspheres (SiO2@TiO2-Ag) with ideal core-shell structure and enhanced photocatalytic activity were successfully fabricated by combining both coating anatase TiO2 on the surface of SiO2 spheres and subsequent depositing face-centered cubic Ag nanoparticles (NPs) on the coated TiO2 surface via novel sol-gel method and Ag-seed-mediated photodeposition (PD) route, respectively. The morphology, structure, composition and optical properties of the resulting composites were characterized in detail. The results reveal that the monodisperse SiO2 spheres of ∼260 nm were covered uniformly and perfectly by the TiO2 nanoparticle coating layer with the thickness of ca. 55 nm by the novel sol-gel method. Further, homogeneously and highly dispersed Ag NPs with an average size of 8 ± 1.5 nm were strongly anchored onto the TiO2 surface in SiO2@TiO2 core-shell spheres by the modified PD process (Ag-seed-mediated PD route), whereas polydispersed Ag aggregates and detached Ag NPs were irregularly deposited over the TiO2 surface in previous works, which is the inherent problem and has not been effectively solved for depositing noble metal NPs such as Au, Ag, Pt, Pd on TiO2 surface by conventional PD method. The formation mechanism of small and uniformly dispersed Ag NPs with narrow size distribution via the modified PD method is tentatively explained by both nucleation kinetics and growth kinetics. The key reason is that the pre-deposited seeds firmly tethered on SiO2@TiO2 spheres served as nucleation sites and anchoring points for the further nucleation and subsequent growth of Ag via photoreduction of Ag+.

  14. Formulation and preparation of Hanford Waste Treatment Plant direct feed low activity waste Effluent Management Facility core simulant

    Energy Technology Data Exchange (ETDEWEB)

    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

  15. Production and purification of immunologically active core protein p24 from HIV-1 fused to ricin toxin B subunit in E. coli

    Directory of Open Access Journals (Sweden)

    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

  16. Differential Rotation within the Earth's Outer Core

    Science.gov (United States)

    Hide, R.; Boggs, D. H.; Dickey, J. O.

    1998-01-01

    Non-steady differential rotation drive by bouyancy forces within the Earth's liquid outer core (OC) plays a key role not only in the generation of the main geomagnetic field by the magnetohydrodynamic (MHD) dynamo process but also in the excitation of irregular fluctuations in the angular speed of rotation of the overlying solid mantle, as evidenced by changes in the length of the day (LOD) on decadal and longer timescales (1-8).

  17. Core-shell N-doped active carbon fiber@graphene composites for aqueous symmetric supercapacitors with high-energy and high-power density

    Science.gov (United States)

    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.

  18. Possibilities of instrumental neutron activation and X-ray fluorescence analyses of sedimentary-magmatic metamorphosed rocks from deep borehole drill cores

    International Nuclear Information System (INIS)

    Gurevich, A.L.; Drynkin, V.I.; Lejpunskaya, D.I.

    1977-01-01

    The possibilities for instrumental neutron-activation and X-ray fluorescence analyses of rocks of metamorphized sedimentary magmatic complexes have been studied with the aid of deep-hole core. The principal characteristics of the conditions of irradiation and of sample measurement ensuring the determination of the content of 26 elements are presented. The use of X-ray fluorescence analysis enables one to determine additionally the content of stron-tium and niobium. Standard specimens of the composition of rocks and complex reference compounds based on phenol formaldehyde resins are used as metrolo.o.ical auxiliaries in the calibration system and in evaluating the correctness of the techniques of instrumental neutron activation