The Effects of Compensatory Auditory Stimulation and High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on Tinnitus Perception - A Randomized Pilot Study.

Science.gov (United States)

Henin, Simon; Fein, Dovid; Smouha, Eric; Parra, Lucas C

2016-01-01

Tinnitus correlates with elevated hearing thresholds and reduced cochlear compression. We hypothesized that reduced peripheral input leads to elevated neuronal gain resulting in the perception of a phantom sound. The purpose of this pilot study was to test whether compensating for this peripheral deficit could reduce the tinnitus percept acutely using customized auditory stimulation. To further enhance the effects of auditory stimulation, this intervention was paired with high-definition transcranial direct current stimulation (HD-tDCS). A randomized sham-controlled, single blind study was conducted in a clinical setting on adult participants with chronic tinnitus (n = 14). Compensatory auditory stimulation (CAS) and HD-tDCS were administered either individually or in combination in order to access the effects of both interventions on tinnitus perception. CAS consisted of sound exposure typical to daily living (20-minute sound-track of a TV show), which was adapted with compressive gain to compensate for deficits in each subject's individual audiograms. Minimum masking levels and the visual analog scale were used to assess the strength of the tinnitus percept immediately before and after the treatment intervention. CAS reduced minimum masking levels, and visual analog scale trended towards improvement. Effects of HD-tDCS could not be resolved with the current sample size. The results of this pilot study suggest that providing tailored auditory stimulation with frequency-specific gain and compression may alleviate tinnitus in a clinical population. Further experimentation with longer interventions is warranted in order to optimize effect sizes.

Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

Directory of Open Access Journals (Sweden)

Rasmus Bjerregaard Christensen

2016-01-01

Full Text Available We employ a semi-classical Langevin approach to study current-induced atomic dynamics in a partially dehydrogenated armchair graphene nanoribbon. All parameters are obtained from density functional theory. The dehydrogenated carbon dimers behave as effective impurities, whose motion decouples from the rest of carbon atoms. The electrical current can couple the dimer motion in a coherent fashion. The coupling, which is mediated by nonconservative and pseudo-magnetic current-induced forces, change the atomic dynamics, and thereby show their signature in this simple system. We study the atomic dynamics and current-induced vibrational instabilities using a simplified eigen-mode analysis. Our study illustrates how armchair nanoribbons can serve as a possible testbed for probing the current-induced forces.

Current-induced atomic dynamics, instabilities, and Raman signals

DEFF Research Database (Denmark)

Lu, Jing Tao; Brandbyge, Mads; Hedegard, Per

2012-01-01

We derive and employ a semiclassical Langevin equation obtained from path integrals to describe the ionic dynamics of a molecular junction in the presence of electrical current. The electronic environment serves as an effective nonequilibrium bath. The bath results in random forces describing Joule...... heating, current-induced forces including the nonconservative wind force, dissipative frictional forces, and an effective Lorentz-type force due to the Berry phase of the nonequilibrium electrons. Using a generic two-level molecular model, we highlight the importance of both current-induced forces...... and Joule heating for the stability of the system. We compare the impact of the different forces, and the wide-band approximation for the electronic structure on our result. We examine the current-induced instabilities (excitation of runaway "waterwheel" modes) and investigate the signature...

Adaptation to delayed auditory feedback induces the temporal recalibration effect in both speech perception and production.

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Yamamoto, Kosuke; Kawabata, Hideaki

2014-12-01

We ordinarily speak fluently, even though our perceptions of our own voices are disrupted by various environmental acoustic properties. The underlying mechanism of speech is supposed to monitor the temporal relationship between speech production and the perception of auditory feedback, as suggested by a reduction in speech fluency when the speaker is exposed to delayed auditory feedback (DAF). While many studies have reported that DAF influences speech motor processing, its relationship to the temporal tuning effect on multimodal integration, or temporal recalibration, remains unclear. We investigated whether the temporal aspects of both speech perception and production change due to adaptation to the delay between the motor sensation and the auditory feedback. This is a well-used method of inducing temporal recalibration. Participants continually read texts with specific DAF times in order to adapt to the delay. Then, they judged the simultaneity between the motor sensation and the vocal feedback. We measured the rates of speech with which participants read the texts in both the exposure and re-exposure phases. We found that exposure to DAF changed both the rate of speech and the simultaneity judgment, that is, participants' speech gained fluency. Although we also found that a delay of 200 ms appeared to be most effective in decreasing the rates of speech and shifting the distribution on the simultaneity judgment, there was no correlation between these measurements. These findings suggest that both speech motor production and multimodal perception are adaptive to temporal lag but are processed in distinct ways.

Current-induced dynamics in carbon atomic contacts

DEFF Research Database (Denmark)

Lu, Jing Tao; Gunst, Tue; Brandbyge, Mads

2011-01-01

voltage, which can be used to explore current-induced vibrational instabilities due the NC/BP forces. Furthermore, using tight-binding and the Brenner potential we illustrate how Langevin-type molecular-dynamics calculations including the Joule heating effect for the carbon-chain systems can be performed...... be used to explore current-induced dynamics and instabilities. We find instabilities at experimentally relevant bias and gate voltages for the carbon-chain system. © 2011 Lü et al....... carbon chain connecting electrically gated graphene electrodes. This illustrates how the device stability can be predicted solely from the modes obtained from the Langevin equation, including the current-induced forces. We point out that the gate offers control of the current, independent of the bias...

Disruption-induced poloidal currents in the tokamak wall

International Nuclear Information System (INIS)

Pustovitov, V.D.

2017-01-01

Highlights: • Induction effects during disruptions and rapid transient events in tokamaks. • Plasma-wall electromagnetic interaction. • Flux-conserving evolution of plasma equilibrium. • Poloidal current induced in the vacuum vessel wall in a tokamak. • Complete analytical derivations and estimates. - Abstract: The poloidal current induced in the tokamak wall during fast transient events is analytically evaluated. The analysis is based on the electromagnetic relations coupled with plasma equilibrium equations. The derived formulas describe the consequences of both thermal and current quenches. In the final form, they give explicit dependence of the wall current on the plasma pressure and current. A comparison with numerical results of Villone et al. [F. Villone, G. Ramogida, G. Rubinacci, Fusion Eng. Des. 93, 57 (2015)] for IGNITOR is performed. Our analysis confirms the importance of the effects described there. The estimates show that the disruption-induced poloidal currents in the wall should be necessarily taken into account in the studies of disruptions and disruption mitigation in ITER.

Disruption-induced poloidal currents in the tokamak wall

Energy Technology Data Exchange (ETDEWEB)

Pustovitov, V.D., E-mail: Pustovitov_VD@nrcki.ru [National Research Centre ‘Kurchatov Institute’, Pl. Kurchatova 1, Moscow 123182 (Russian Federation); National Research Nuclear University MEPhI, Kashirskoe sh. 31, Moscow 115409, Russia (Russian Federation)

2017-04-15

Highlights: • Induction effects during disruptions and rapid transient events in tokamaks. • Plasma-wall electromagnetic interaction. • Flux-conserving evolution of plasma equilibrium. • Poloidal current induced in the vacuum vessel wall in a tokamak. • Complete analytical derivations and estimates. - Abstract: The poloidal current induced in the tokamak wall during fast transient events is analytically evaluated. The analysis is based on the electromagnetic relations coupled with plasma equilibrium equations. The derived formulas describe the consequences of both thermal and current quenches. In the final form, they give explicit dependence of the wall current on the plasma pressure and current. A comparison with numerical results of Villone et al. [F. Villone, G. Ramogida, G. Rubinacci, Fusion Eng. Des. 93, 57 (2015)] for IGNITOR is performed. Our analysis confirms the importance of the effects described there. The estimates show that the disruption-induced poloidal currents in the wall should be necessarily taken into account in the studies of disruptions and disruption mitigation in ITER.

Strong mechanically induced effects in DC current-biased suspended Josephson junctions

Science.gov (United States)

McDermott, Thomas; Deng, Hai-Yao; Isacsson, Andreas; Mariani, Eros

2018-01-01

Superconductivity is a result of quantum coherence at macroscopic scales. Two superconductors separated by a metallic or insulating weak link exhibit the AC Josephson effect: the conversion of a DC voltage bias into an AC supercurrent. This current may be used to activate mechanical oscillations in a suspended weak link. As the DC-voltage bias condition is remarkably difficult to achieve in experiments, here we analyze theoretically how the Josephson effect can be exploited to activate and detect mechanical oscillations in the experimentally relevant condition with purely DC current bias. We unveil how changing the strength of the electromechanical coupling results in two qualitatively different regimes showing dramatic effects of the oscillations on the DC-voltage characteristic of the device. These include the appearance of Shapiro-type plateaus for weak coupling and a sudden mechanically induced retrapping for strong coupling. Our predictions, measurable in state-of-the-art experimental setups, allow the determination of the frequency and quality factor of the resonator using DC only techniques.

Effects of spin-polarized current on pulse field-induced precessional magnetization reversal

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Guang-fu Zhang

2012-12-01

Full Text Available We investigate effects of a small DC spin-polarized current on the pulse field-induced precessional magnetization reversal in a thin elliptic magnetic element by micromagnetic simulations. We find that the spin-polarized current not only broadens the time window of the pulse duration, in which a successful precessional reversal is achievable, but also significantly suppresses the magnetization ringing after the reversal. The pulse time window as well as the decay rate of the ringing increase with increasing the current density. When a spin-polarized current with 5 MA/cm2 is applied, the time window increases from 80 ps to 112 ps, and the relaxation time of the ringing decreases from 1.1 ns to 0.32 ns. Our results provide useful information to achieve magnetic nanodevices based on precessional switching.

The effects of negative emotions on sensory perception: fear but not anger decreases tactile sensitivity.

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Kelley, Nicholas J; Schmeichel, Brandon J

2014-01-01

Emotions and sensory perceptions are closely intertwined. Of the five senses, sight has been by far the most extensively studied sense in emotion research. Relatively less is known about how emotions influence the other four senses. Touch is essential for nonverbal communication in both humans and other animals. The current investigation tested competing hypotheses about the effect of fear on tactile perception. One hypothesis based on evolutionary considerations predicts that fear enhances sensory perception, including tactile sensitivity. A competing hypothesis based on research on peripheral psychophysiology predicts that fear should decrease tactile sensitivity. Two experiments that induced negative emotional states and measured two-point discrimination ability at the fingertip found that fear reduces tactile sensitivity relative to anger or a neutral control condition (Studies 1 and 2). These findings did not appear to be driven by participants' naïve beliefs about the influence of emotions on touch (Study 3). The results represent the first evidence of the causal impact of emotional states on tactile sensitivity, are consistent with prior evidence for the peripheral physiological effects of fear, and offer novel empirical grounds for developing and advancing theories of emotional influences on sensory perception.

Current-induced switching in a magnetic insulator

Science.gov (United States)

Avci, Can Onur; Quindeau, Andy; Pai, Chi-Feng; Mann, Maxwell; Caretta, Lucas; Tang, Astera S.; Onbasli, Mehmet C.; Ross, Caroline A.; Beach, Geoffrey S. D.

2017-03-01

The spin Hall effect in heavy metals converts charge current into pure spin current, which can be injected into an adjacent ferromagnet to exert a torque. This spin-orbit torque (SOT) has been widely used to manipulate the magnetization in metallic ferromagnets. In the case of magnetic insulators (MIs), although charge currents cannot flow, spin currents can propagate, but current-induced control of the magnetization in a MI has so far remained elusive. Here we demonstrate spin-current-induced switching of a perpendicularly magnetized thulium iron garnet film driven by charge current in a Pt overlayer. We estimate a relatively large spin-mixing conductance and damping-like SOT through spin Hall magnetoresistance and harmonic Hall measurements, respectively, indicating considerable spin transparency at the Pt/MI interface. We show that spin currents injected across this interface lead to deterministic magnetization reversal at low current densities, paving the road towards ultralow-dissipation spintronic devices based on MIs.

Bradykinin induced a positive chronotropic effect via stimulation of T- and L-type calcium currents in heart cells.

Science.gov (United States)

El-Bizri, Nesrine; Bkaily, Ghassan; Wang, Shimin; Jacques, Danielle; Regoli, Domenico; D'Orléans-Juste, Pedro; Sukarieh, Rami

2003-03-01

Using Fluo-3 calcium dye confocal microscopy and spontaneously contracting embryonic chick heart cells, bradykinin (10(-10) M) was found to induce positive chronotropic effects by increasing the frequency of the transient increase of cytosolic and nuclear free Ca2+. Pretreatment of the cells with either B1 or B2 receptor antagonists (R126 and R817, respectively) completely prevented bradykinin (BK) induced positive chronotropic effects on spontaneously contracting single heart cells. Using the whole-cell voltage clamp technique and ionic substitution to separate the different ionic current species, our results showed that BK (10(-6) M) had no effect on fast Na+ inward current and delayed outward potassium current. However, both L- and T-type Ca2+ currents were found to be increased by BK in a dose-dependent manner (10(-10)-10(-7) M). The effects of BK on T- and L-type Ca2+ currents were partially blocked by the B1 receptor antagonist [Leu8]des-Arg9-BK (R592) (10(-7) M) and completely reversed by the B2 receptor antagonist D-Arg[Hyp3,D-Phe7,Leu8]BK (R-588) (10(-7) M) or pretreatment with pertussis toxin (PTX). These results demonstrate that BK induced a positive chronotropic effect via stimulation of T- and L-type Ca2+ currents in heart cells mainly via stimulation of B2 receptor coupled to PTX-sensitive G-proteins. The increase of both types of Ca2+ current by BK in heart cells may explain the positive inotropic and chronotropic effects of this hormone.

Current-Induced Membrane Discharge

DEFF Research Database (Denmark)

Andersen, Mathias Bækbo; van Soestbergen, M.; Mani, A.

2012-01-01

. Salt depletion leads to a large electric field resulting in a local pH shift within the membrane with the effect that the membrane discharges and loses its ion selectivity. Since salt co-ions, H+ ions, and OH- ions contribute to OLC, CIMD interferes with electrodialysis (salt counterion removal...... neglects chemical effects and remains to be quantitatively tested. Here, we show that charge regulation and water self-ionization can lead to OLC by "current-induced membrane discharge'' (CIMD), even in the absence of fluid flow, in ion-exchange membranes much thicker than the local Debye screening length...

Risk Perceptions of Little Cigar and Cigarillo Smoking Among Adult Current Cigarette Smokers.

Science.gov (United States)

Sterling, Kymberle L; Majeed, Ban A; Nyman, Amy; Eriksen, Michael

2017-11-01

Few studies have examined the perceptions of risk of little cigar and cigarillo (LCC) smoking among cigarette smokers, which is important for expanding regulatory policies and developing prevention programs. We examined current cigarette smokers' perceived harm of LCC smoking, and determined whether these perceptions were associated with susceptibility and intention to continue smoking LCCs. Data were from the 2014 Tobacco Products and Risk Perceptions Survey of a probability sample of 5717 US adults. Data were analyzed for a subsample of 1191 current cigarette smokers who were stratified into three groups: (1) dual current cigarette smokers who had ever used LCCs, (2) current smokers susceptible to LCC smoking, and (3) current smokers who were not susceptible to LCC smoking. Overall, 47.2% of participants were dual smokers, 12.7% were susceptible to LCC smoking, and 40.1% were not susceptible. Perceptions of risk of LCCs varied across the groups. Dual smokers were more likely to perceive that daily LCC smoking is "very risky" (OR = 1.64, 95% CI = 1.08, 2.41) while occasional LCC smoking is only "somewhat risky" (OR = 1.71, 95% CI = 1.02, 2.87). Of the dual smokers, 20.7% intended to continue smoking LCCs in the future. Perceptions of addiction and risk of daily LCC smoking significantly predicted intention to continue LCC smoking. Addiction perceptions also significantly predicted susceptibility to initiate LCC smoking. Perceptions about harms from and addiction to LCCs could predict future LCC smoking. Health communication campaigns need to address the harms of LCCs. Our data suggest that perceptions of risk about the addictiveness of LCCs and frequency of use are important determinants of the LCC smoking susceptibility among some cigarette smokers and intended continued use among cigarette smokers with a history of LCC use. Health communication campaigns should address misperceptions related to LCCs. © The Author 2016. Published by Oxford University Press on

Both the cutaneous sensation and phosphene perception are modulated in a frequency-specific manner during transcranial alternating current stimulation.

Science.gov (United States)

Turi, Zs; Ambrus, G G; Janacsek, K; Emmert, K; Hahn, L; Paulus, W; Antal, A

2013-01-01

Transcranial alternating current stimulation (tACS) is a non-invasive stimulation technique for shaping neuroplastic processes and possibly entraining ongoing neural oscillations in humans. Despite the growing number of studies using tACS, we know little about the procedural sensations caused by stimulation. In order to fill this gap, we explored the cutaneous sensation and phosphene perception during tACS. Twenty healthy participants took part in a randomized, single-blinded, sham-controlled study, where volunteers received short duration stimulation at 1.0 mA intensity between 2 to 250 Hz using the standard left motor cortex-contralateral supraorbital montage. We recorded the perception onset latency and the strength of the sensations assessed by visual rating scale as dependent variables. We found that tACS evoked both cutaneous sensation and phosphene perception in a frequency-dependent manner. Our results show that the most perceptible procedural sensations were induced in the beta and gamma frequency range, especially at 20 Hz, whereas minimal procedural sensations were indicated in the ripple range (140 and 250 Hz). We believe that our results provide a relevant insight into the procedural sensations caused by oscillatory currents, and will offer a basis for developing more sophisticated stimulation protocols and study designs for future investigations.

Current-Induced Spin Polarization at a Single Heterojunction

NARCIS (Netherlands)

Silov, A.; Blajnov, P.; Wolter, J.H.; Hey, R.; Ploog, K.; Averkiev, N.S.; Menendez, J.; Walle, van der C.G.

2005-01-01

We have experimentally achieved spin-polarization by a lateral current in a single non-magnetic semiconductor heterojunction. The effect does not require an applied magnetic field or ferromagnetic contacts. The current-induced spin orientation can be seen as the inverse of the circular

Effects of Transcranial Direct Current Stimulation Block Remifentanil-Induced Hyperalgesia: A Randomized, Double-Blind Clinical Trial

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Gilberto Braulio

2018-02-01

Full Text Available Background: Remifentanil-induced hyperalgesia (r-IH involves an imbalance in the inhibitory and excitatory systems. As the transcranial Direct Current Stimulation (tDCS modulates the thalamocortical synapses in a top-down manner, we hypothesized that the active (a-t-DCS would be more effective than sham(s-tDCS to prevent r-IH. We used an experimental paradigm to induce temporal summation of pain utilizing a repetitive cold test (rCOLDT assessed by the Numerical Pain Score (NPS 0-10 and we evaluated the function of the descending pain modulatory system (DPMS by the change on the NPS (0–10 during the conditioned pain modulation (CPM-task (primary outcomes. We tested whether a-tDCS would be more effective than s-tDCS to improve pain perception assessed by the heat pain threshold (HPT and the reaction time during the ice-water pain test (IPT (secondary outcomes.Methods: This double-blinded, factorial randomized trial included 48 healthy males, ages ranging 19–40 years. They were randomized into four equal groups: a-tDCS/saline, s-tDCS/saline, a-tDCS/remifentanil and s-tDCS/remifentanil. tDCS was applied over the primary motor cortex, during 20 min at 2 mA, which was introduced 10 min after starting remifentanil infusion at 0.06 μg⋅kg-1⋅min-1 or saline.Results: An ANCOVA mixed model revealed that during the rCOLDT, there was a significant main effect on the NPS scores (F = 3.81; P = 0.01. The s-tDCS/remifentanil group presented larger pain scores during rCOLDT, [mean (SD 5.49 (1.04] and a-tDCS/remifentanil group had relative lower pain scores [4.15 (1.62]; showing its blocking effect on r-IH. a-tDCS/saline and s-tDCS/saline groups showed lowest pain scores during rCOLDT, [3.11 (1.2] and [3.15 (1.62], respectively. The effect of sedation induced by remifentanil during the rCOLDT was not significant (F = 0.76; P = 0.38. Remifentanil groups showed positive scores in the NPS (0–10 during the CPM-task, that is, it produced a disengagement of

Effects of induced sad mood on facial emotion perception in young and older adults.

Science.gov (United States)

Lawrie, Louisa; Jackson, Margaret C; Phillips, Louise H

2018-02-15

Older adults perceive less intense negative emotion in facial expressions compared to younger counterparts. Prior research has also demonstrated that mood alters facial emotion perception. Nevertheless, there is little evidence which evaluates the interactive effects of age and mood on emotion perception. This study investigated the effects of sad mood on younger and older adults' perception of emotional and neutral faces. Participants rated the intensity of stimuli while listening to sad music and in silence. Measures of mood were administered. Younger and older participants' rated sad faces as displaying stronger sadness when they experienced sad mood. While younger participants showed no influence of sad mood on happiness ratings of happy faces, older adults rated happy faces as conveying less happiness when they experienced sad mood. This study demonstrates how emotion perception can change when a controlled mood induction procedure is applied to alter mood in young and older participants.

Investigation on a new inducer of pulsed eddy current thermography

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Min He

2016-09-01

Full Text Available In this paper, a new inducer of pulsed eddy current thermography (PECT is presented. The use of the inducer can help avoid the problem of blocking the infrared (IR camera’s view in eddy current thermography technique. The inducer can also provide even heating of the test specimen. This paper is concerned with the temperature distribution law around the crack on a specimen when utilizing the new inducer. Firstly, relative mathematical models are provided. In the following section, eddy current distribution and temperature distribution around the crack are studied using the numerical simulation method. The best separation distance between the inducer and the specimen is also determined. Then, results of temperature distribution around the crack stimulated by the inducer are gained by experiments. Effect of current value on temperature rise is studied as well in the experiments. Based on temperature data, temperature features of the crack are discussed.

Influence of Customer Quality Perception on the Effectiveness of Commercial Stimuli for Electronic Products.

Science.gov (United States)

Garrido-Morgado, Álvaro; González-Benito, Óscar; Martos-Partal, Mercedes

2016-01-01

Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality, and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers' quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality-linked to the brand-and intrinsic quality-related with internal product characteristics. We propose that (i) cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name) is more salient for affective loyalty and, (ii) different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe's largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due to the use of a brand name

Depletion region surface effects in electron beam induced current measurements

Energy Technology Data Exchange (ETDEWEB)

Haney, Paul M.; Zhitenev, Nikolai B. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Yoon, Heayoung P. [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Gaury, Benoit [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Maryland NanoCenter, University of Maryland, College Park, Maryland 20742 (United States)

2016-09-07

Electron beam induced current (EBIC) is a powerful characterization technique which offers the high spatial resolution needed to study polycrystalline solar cells. Current models of EBIC assume that excitations in the p-n junction depletion region result in perfect charge collection efficiency. However, we find that in CdTe and Si samples prepared by focused ion beam (FIB) milling, there is a reduced and nonuniform EBIC lineshape for excitations in the depletion region. Motivated by this, we present a model of the EBIC response for excitations in the depletion region which includes the effects of surface recombination from both charge-neutral and charged surfaces. For neutral surfaces, we present a simple analytical formula which describes the numerical data well, while the charged surface response depends qualitatively on the location of the surface Fermi level relative to the bulk Fermi level. We find that the experimental data on FIB-prepared Si solar cells are most consistent with a charged surface and discuss the implications for EBIC experiments on polycrystalline materials.

Micromagnetic Simulation of Strain-Assisted Current-Induced Magnetization Switching

Directory of Open Access Journals (Sweden)

H. B. Huang

2016-01-01

Full Text Available We investigated the effect of substrate misfit strain on the current-induced magnetization switching in magnetic tunnel junctions by combining micromagnetic simulation with phase-field microelasticity theory. Our results indicate that the positive substrate misfit strain can decrease the critical current density of magnetization switching by pushing the magnetization from out-of-plane to in-plane directions, while the negative strain pushes the magnetization back to the out-of-plane directions. The magnetic domain evolution is obtained to demonstrate the strain-assisted current-induced magnetization switching.

Electric-current-induced step bunching on Si(111)

International Nuclear Information System (INIS)

Homma, Yoshikazu; Aizawa, Noriyuki

2000-01-01

We experimentally investigated step bunching induced by direct current on vicinal Si(111)'1x1' surfaces using scanning electron microscopy and atomic force microscopy. The scaling relation between the average step spacing l b and the number of steps N in a bunch, l b ∼N -α , was determined for four step-bunching temperature regimes above the 7x7-'1x1' transition temperature. The step-bunching rate and scaling exponent differ between neighboring step-bunching regimes. The exponent α is 0.7 for the two regimes where the step-down current induces step bunching (860-960 and 1210-1300 deg. C), and 0.6 for the two regimes where the step-up current induces step bunching (1060-1190 and >1320 deg. C). The number of single steps on terraces also differs in each of the four temperature regimes. For temperatures higher than 1280 deg. C, the prefactor of the scaling relation increases, indicating an increase in step-step repulsion. The scaling exponents obtained agree reasonably well with those predicted by theoretical models. However, they give unrealistic values for the effective charges of adatoms for step-up-current-induced step bunching when the 'transparent' step model is used

Salvinorin-A Induces Intense Dissociative Effects, Blocking External Sensory Perception and Modulating Interoception and Sense of Body Ownership in Humans.

Science.gov (United States)

Maqueda, Ana Elda; Valle, Marta; Addy, Peter H; Antonijoan, Rosa Maria; Puntes, Montserrat; Coimbra, Jimena; Ballester, Maria Rosa; Garrido, Maite; González, Mireia; Claramunt, Judit; Barker, Steven; Johnson, Matthew W; Griffiths, Roland R; Riba, Jordi

2015-06-05

Salvinorin-A is a terpene with agonist properties at the kappa-opioid receptor, the binding site of endogenous dynorphins. Salvinorin-A is found in Salvia divinorum, a psychoactive plant traditionally used by the Mazatec people of Oaxaca, Mexico, for medicinal and spiritual purposes. Previous studies with the plant and salvinorin-A have reported psychedelic-like changes in perception, but also unusual changes in body awareness and detachment from external reality. Here we comprehensively studied the profiles of subjective effects of increasing doses of salvinorin-A in healthy volunteers, with a special emphasis on interoception. A placebo and three increasing doses of vaporized salvinorin-A (0.25, 0.50, and 1mg) were administered to eight healthy volunteers with previous experience in the use of psychedelics. Drug effects were assessed using a battery of questionnaires that included, among others, the Hallucinogen Rating Scale, the Altered States of Consciousness, and a new instrument that evaluates different aspects of body awareness: the Multidimensional Assessment for Interoceptive Awareness. Salvinorin-A led to a disconnection from external reality, induced elaborate visions and auditory phenomena, and modified interoception. The lower doses increased somatic sensations, but the highest dose led to a sense of a complete loss of contact with the body. Salvinorin-A induced intense psychotropic effects characterized by a dose-dependent gating of external audio-visual information and an inverted-U dose-response effect on body awareness. These results suggest a prominent role for the kappa opioid receptor in the regulation of sensory perception, interoception, and the sense of body ownership in humans. © The Author 2015. Published by Oxford University Press on behalf of CINP.

An Adaptation-Induced Repulsion Illusion in Tactile Spatial Perception

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Lux Li

2017-06-01

Full Text Available Following focal sensory adaptation, the perceived separation between visual stimuli that straddle the adapted region is often exaggerated. For instance, in the tilt aftereffect illusion, adaptation to tilted lines causes subsequently viewed lines with nearby orientations to be perceptually repelled from the adapted orientation. Repulsion illusions in the nonvisual senses have been less studied. Here, we investigated whether adaptation induces a repulsion illusion in tactile spatial perception. In a two-interval forced-choice task, participants compared the perceived separation between two point-stimuli applied on the forearms successively. Separation distance was constant on one arm (the reference and varied on the other arm (the comparison. In Experiment 1, we took three consecutive baseline measurements, verifying that in the absence of manipulation, participants’ distance perception was unbiased across arms and stable across experimental blocks. In Experiment 2, we vibrated a region of skin on the reference arm, verifying that this focally reduced tactile sensitivity, as indicated by elevated monofilament detection thresholds. In Experiment 3, we applied vibration between the two reference points in our distance perception protocol and discovered that this caused an illusory increase in the separation between the points. We conclude that focal adaptation induces a repulsion aftereffect illusion in tactile spatial perception. The illusion provides clues as to how the tactile system represents spatial information. The analogous repulsion aftereffects caused by adaptation in different stimulus domains and sensory systems may point to fundamentally similar strategies for dynamic sensory coding.

Neural mechanisms underlying sound-induced visual motion perception: An fMRI study.

Science.gov (United States)

Hidaka, Souta; Higuchi, Satomi; Teramoto, Wataru; Sugita, Yoichi

2017-07-01

Studies of crossmodal interactions in motion perception have reported activation in several brain areas, including those related to motion processing and/or sensory association, in response to multimodal (e.g., visual and auditory) stimuli that were both in motion. Recent studies have demonstrated that sounds can trigger illusory visual apparent motion to static visual stimuli (sound-induced visual motion: SIVM): A visual stimulus blinking at a fixed location is perceived to be moving laterally when an alternating left-right sound is also present. Here, we investigated brain activity related to the perception of SIVM using a 7T functional magnetic resonance imaging technique. Specifically, we focused on the patterns of neural activities in SIVM and visually induced visual apparent motion (VIVM). We observed shared activations in the middle occipital area (V5/hMT), which is thought to be involved in visual motion processing, for SIVM and VIVM. Moreover, as compared to VIVM, SIVM resulted in greater activation in the superior temporal area and dominant functional connectivity between the V5/hMT area and the areas related to auditory and crossmodal motion processing. These findings indicate that similar but partially different neural mechanisms could be involved in auditory-induced and visually-induced motion perception, and neural signals in auditory, visual, and, crossmodal motion processing areas closely and directly interact in the perception of SIVM. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Term Geomagnetically Induced Current Observations From New Zealand: Peak Current Estimates for Extreme Geomagnetic Storms

Science.gov (United States)

Rodger, Craig J.; Mac Manus, Daniel H.; Dalzell, Michael; Thomson, Alan W. P.; Clarke, Ellen; Petersen, Tanja; Clilverd, Mark A.; Divett, Tim

2017-11-01

Geomagnetically induced current (GIC) observations made in New Zealand over 14 years show induction effects associated with a rapidly varying horizontal magnetic field (dBH/dt) during geomagnetic storms. This study analyzes the GIC observations in order to estimate the impact of extreme storms as a hazard to the power system in New Zealand. Analysis is undertaken of GIC in transformer number six in Islington, Christchurch (ISL M6), which had the highest observed currents during the 6 November 2001 storm. Using previously published values of 3,000 nT/min as a representation of an extreme storm with 100 year return period, induced currents of 455 A were estimated for Islington (with the 95% confidence interval range being 155-605 A). For 200 year return periods using 5,000 nT/min, current estimates reach 755 A (confidence interval range 155-910 A). GIC measurements from the much shorter data set collected at transformer number 4 in Halfway Bush, Dunedin, (HWB T4), found induced currents to be consistently a factor of 3 higher than at Islington, suggesting equivalent extreme storm effects of 460-1,815 A (100 year return) and 460-2,720 A (200 year return). An estimate was undertaken of likely failure levels for single-phase transformers, such as HWB T4 when it failed during the 6 November 2001 geomagnetic storm, identifying that induced currents of 100 A can put such transformer types at risk of damage. Detailed modeling of the New Zealand power system is therefore required to put this regional analysis into a global context.

Effect of Human Model Height and Sex on Induced Current Dosimetry in Household Induction Heater Users

Science.gov (United States)

Tarao, Hiroo; Hayashi, Noriyuki; Isaka, Katsuo

Induced currents in the high-resolution, anatomical human models are numerically calculated by the impedance method. The human models are supposed to be exposed to highly inhomogeneous 20.9 kHz magnetic fields from a household induction heater (IH). In the case of the adult models, the currents ranging from 5 to 19 mA/m2 are induced for between the shoulder and lower abdomen. Meanwhile, in the case of the child models, the currents ranging from 5 to 21 mA/m2 are induced for between the head and abdomen. In particular, the induced currents near the brain tissue are almost the same as those near the abdomen. When the induced currents in the central nervous system tissues are considered, the induced currents in the child model are 2.1 to 6.9 times as large as those in the adult model under the same B-field exposure environment. These results suggest the importance of further investigation intended for a pregnant female who uses the IH as well as for a child (or the IH users of small standing height).

Current-induced torques and interfacial spin-orbit coupling

KAUST Repository

Haney, Paul M.; Lee, Hyun-Woo; Lee, Kyung-Jin; Manchon, Aurelien; Stiles, M. D.

2013-01-01

In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

Current-induced torques and interfacial spin-orbit coupling

KAUST Repository

Haney, Paul M.

2013-12-19

In bilayer systems consisting of an ultrathin ferromagnetic layer adjacent to a metal with strong spin-orbit coupling, an applied in-plane current induces torques on the magnetization. The torques that arise from spin-orbit coupling are of particular interest. Here we use first-principles methods to calculate the current-induced torque in a Pt-Co bilayer to help determine the underlying mechanism. We focus exclusively on the analog to the Rashba torque, and do not consider the spin Hall effect. The details of the torque depend strongly on the layer thicknesses and the interface structure, providing an explanation for the wide variation in results found by different groups. The torque depends on the magnetization direction in a way similar to that found for a simple Rashba model. Artificially turning off the exchange spin splitting and separately the spin-orbit coupling potential in the Pt shows that the primary source of the “fieldlike” torque is a proximate spin-orbit effect on the Co layer induced by the strong spin-orbit coupling in the Pt.

Perceptions of a Changing World Induce Hope and Promote Peace in Intractable Conflicts

Science.gov (United States)

Cohen-Chen, Smadar; Crisp, Richard J.; Halperin, Eran

2015-01-01

The importance of hope in promoting conciliatory attitudes has been asserted in the field of conflict resolution. However, little is known about conditions inducing hope, especially in intractable conflicts, where reference to the outgroup may backfire. In the current research, five studies yielded convergent support for the hypothesis that hope for peace stems from a general perception of the world as changing. In Study 1, coders observed associations between belief in a changing world, hope regarding peace, and support for concessions. Study 2 revealed the hypothesized relations using self-reported measures. Studies 3 and 4 established causality by instilling a perception of the world as changing (vs. unchanging) using narrative and drawing manipulations. Study 5 compared the changing world message with a control condition during conflict escalation. Across studies, although the specific context was not referred to, the belief in a changing world increased support for concessions through hope for peace. PMID:25713171

Perceptions of a changing world induce hope and promote peace in intractable conflicts.

Science.gov (United States)

Cohen-Chen, Smadar; Crisp, Richard J; Halperin, Eran

2015-04-01

The importance of hope in promoting conciliatory attitudes has been asserted in the field of conflict resolution. However, little is known about conditions inducing hope, especially in intractable conflicts, where reference to the outgroup may backfire. In the current research, five studies yielded convergent support for the hypothesis that hope for peace stems from a general perception of the world as changing. In Study 1, coders observed associations between belief in a changing world, hope regarding peace, and support for concessions. Study 2 revealed the hypothesized relations using self-reported measures. Studies 3 and 4 established causality by instilling a perception of the world as changing (vs. unchanging) using narrative and drawing manipulations. Study 5 compared the changing world message with a control condition during conflict escalation. Across studies, although the specific context was not referred to, the belief in a changing world increased support for concessions through hope for peace. © 2015 by the Society for Personality and Social Psychology, Inc.

Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force

International Nuclear Information System (INIS)

Antunes, A; Glover, P M; Li, Y; Mian, O S; Day, B L

2012-01-01

Large static magnetic fields may be employed in magnetic resonance imaging (MRI). At high magnetic field strengths (usually from about 3 T and above) it is possible for humans to perceive a number of effects. One such effect is mild vertigo. Recently, Roberts et al (2011 Current Biology 21 1635–40) proposed a Lorentz-force mechanism resulting from the ionic currents occurring naturally in the endolymph of the vestibular system. In the present work a more detailed calculation of the forces and resulting pressures in the vestibular system is carried out using a numerical model. Firstly, realistic 3D finite element conductivity and fluid maps of the utricle and a single semi-circular canal containing the current sources (dark cells) and sinks (hair cells) of the utricle and ampulla were constructed. Secondly, the electrical current densities in the fluid are calculated. Thirdly, the developed Lorentz force is used directly in the Navier–Stokes equation and the trans-cupular pressure is computed. Since the driving force field is relatively large in comparison with the advective acceleration, we demonstrate that it is possible to perform an approximation in the Navier–Stokes equations that reduces the problem to solving a simpler Poisson equation. This simplification allows rapid and easy calculation for many different directions of applied magnetic field. At 7 T a maximum cupula pressure difference of 1.6 mPa was calculated for the combined ampullar (0.7 µA) and utricular (3.31 µA) distributed current sources, assuming a hair-cell resting current of 100 pA per unit. These pressure values are up to an order of magnitude lower than those proposed by Roberts et al using a simplistic model and calculation, and are in good agreement with the estimated pressure values for nystagmus velocities in caloric experiments. This modeling work supports the hypothesis that the Lorentz force mechanism is a significant contributor to the perception of magnetic field induced

Effective Instructional Management: Perceptions and Recommendations from High School Administrators

Science.gov (United States)

Knechtel, Troy

2010-01-01

The two overarching research questions of this study are: What are the perceptions of high school administrators regarding the effectiveness of their current approach to instructional management? What recommendations do high school administrators have for effective strategies for instructional management? To answer these questions, a qualitative…

Influence of Customer Quality Perception on the Effectiveness of Commercial Stimuli for Electronic Products

Science.gov (United States)

Garrido-Morgado, Álvaro; González-Benito, Óscar; Martos-Partal, Mercedes

2016-01-01

Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality, and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers' quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality—linked to the brand—and intrinsic quality—related with internal product characteristics. We propose that (i) cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name) is more salient for affective loyalty and, (ii) different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe's largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due to the use of a brand

Influence of customer quality perception on the effectiveness of commercial stimuli for electronic products

Directory of Open Access Journals (Sweden)

Álvaro eGarrido-Morgado

2016-03-01

Full Text Available Creating and maintaining customer loyalty are strategic requirements for modern business. In the current competitive context, product quality and brand experience are crucial in building and maintaining customer loyalty. Consumer loyalty, which may be classified into cognitive loyalty and affective loyalty, is related to customers’ quality perception. Cue utilization theory distinguishes two dimensions for perceived quality, extrinsic quality –linked to the brand– and intrinsic quality –related with internal product characteristics. We propose that (i cognitive loyalty is more influenced by intrinsic product quality whereas extrinsic product quality (brand name is more salient for affective loyalty and, (ii different commercial stimuli have a differential effectiveness on intrinsic and extrinsic perceived quality. In fact, in this study, we analyze how perceived quality dimensions may influence the effectiveness of two different commercial stimuli: displays and advertising flyers. While displays work within the point of sale under time-constrained conditions where consumers are more likely to use heuristics to simplify their decisions, advertising flyers work outside of the point of sale under low time-constrained conditions, and therefore favor a more reasoned purchase decision where systematic processing will be more likely. We analyze the role of quality perception in determining the effectiveness of both these commercial stimuli for selling products that induce high purchase involvement and perceived risk. The empirical analysis focuses on computer products sold by one of Europe’s largest computer retailers and it combines scanner, observational, and survey data. The results show that both dimensions of quality perceptions moderate the influence of displays and advertising flyers on sales, but their impact is different on each commercial stimuli. Extrinsic quality perception increases to a greater extent the effect of displays due

Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

DEFF Research Database (Denmark)

Christensen, Rasmus Bjerregaard; Lu, Jing Tao; Hedegard, Per

2016-01-01

We employ a semi-classical Langevin approach to study current-induced atomic dynamics in a partially dehydrogenated armchair graphene nanoribbon. All parameters are obtained from density functional theory. The dehydrogenated carbon dimers behave as effective impurities, whose motion decouples from...

Current-induced runaway vibrations in dehydrogenated graphene nanoribbons

DEFF Research Database (Denmark)

Christensen, Rasmus Bjerregaard; Lu, Jing Tao; Hedegard, Per

2016-01-01

We employ a semi-classical Langevin approach to study current-induced atomic dynamics in a partially dehydrogenated armchair graphene nanoribbon. All parameters are obtained from density functional theory. The dehydrogenated carbon dimers behave as effective impurities, whose motion decouples fro...

Heavy-ion induced current through an oxide layer

International Nuclear Information System (INIS)

Takahashi, Yoshihiro; Ohki, Takahiro; Nagasawa, Takaharu; Nakajima, Yasuhito; Kawanabe, Ryu; Ohnishi, Kazunori; Hirao, Toshio; Onoda, Shinobu; Mishima, Kenta; Kawano, Katsuyasu; Itoh, Hisayoshi

2007-01-01

In this paper, the heavy-ion induced current in MOS structure is investigated. We have measured the transient gate current in a MOS capacitor and a MOSFET induced by single heavy-ions, and found that a transient current can be observed when the semiconductor surface is under depletion condition. In the case of MOSFET, a transient gate current with both positive and negative peaks is observed if the ion hits the gate area, and that the total integrated charge is almost zero within 100-200 ns after irradiation. From these results, we conclude that the radiation-induced gate current is dominated by a displacement current. We also discuss the generation mechanism of the radiation-induced current through the oxide layer by device simulation

Current-induced domain wall motion in magnetic nanowires with spatial variation

International Nuclear Information System (INIS)

Ieda, Jun'ichi; Sugishita, Hiroki; Maekawa, Sadamichi

2010-01-01

We model current-induced domain wall motion in magnetic nanowires with the variable width. Employing the collective coordinate method we trace the wall dynamics. The effect of the width modulation is implemented by spatial dependence of an effective magnetic field. The wall destination in the potential energy landscape due to the magnetic anisotropy and the spatial nonuniformity is obtained as a function of the current density. For a nanowire of a periodically modulated width, we identify three (pinned, nonlinear, and linear) current density regimes for current-induced wall motion. The threshold current densities depend on the pulse duration as well as the magnitude of wire modulation. In the nonlinear regime, application of ns order current pulses results in wall displacement which opposes or exceeds the prediction of the spin transfer mechanism. The finding explains stochastic nature of the domain wall displacement observed in recent experiments.

Effects of tensile and compressive stresses on irradiation-induced swelling in AISI 316

International Nuclear Information System (INIS)

Lauritzen, T.; Bell, W.L.; Konze, G.M.; Rosa, J.M.; Vaidyanathan, S.; Garner, F.A.

1985-05-01

The results of two recent experiments indicate that the current perception of stress-affected swelling needs revision. It appears that compressive stresses do not delay swelling as previously modeled but actually accelerate swelling at a rate comparable to that induced by tensile stresses

Photoinduced current and emission induced by current in a ...

Indian Academy of Sciences (India)

... Refresher Courses · Symposia · Live Streaming. Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 3. Photoinduced current and emission induced by current in a nanowire transistor: Temperature dependence. Darehdor Mahvash Arabi Shahtahmassebi Nasser. Regular Volume 86 Issue 3 March 2016 pp ...

Effects of Transverse Magnetic Anisotropy on Current-Induced Spin Switching

Science.gov (United States)

Misiorny, Maciej; Barnaś, Józef

2013-07-01

Spin-polarized transport through bistable magnetic adatoms or single-molecule magnets (SMMs), which exhibit both uniaxial and transverse magnetic anisotropy, is considered theoretically. The main focus is on the impact of transverse anisotropy on transport characteristics and the adatom’s or SMM’s spin. In particular, we analyze the role of quantum tunneling of magnetization (QTM) in the mechanism of the current-induced spin switching, and show that the QTM phenomenon becomes revealed as resonant peaks in the average values of the molecule’s spin and in the charge current. These features appear at some resonant fields and are observable when at least one of the electrodes is ferromagnetic.

Matrix effect on emission/current correlated analysis in laser-induced breakdown spectroscopy of liquid droplets

International Nuclear Information System (INIS)

Huang, J.-S.; Ke, C.-B.; Lin, K.-C.

2004-01-01

We have investigated influence of matrix salts on the liquid droplets by laser-induced breakdown spectroscopy (LIBS). An electrospray ionization technique coupled with LIBS is employed to generate the microdroplets of the Na sample solution with various matrix salts added. A sequence of single-shot time-resolved LIB emission signals is detected. The LIB signal intensity integrated within a gate linearly correlates with the plasma-induced current response obtained simultaneously on a single-shot basis. The slopes thus obtained increase with the sample concentration, but appear to be irrespective of different matrix salts, added up to a 2000 mg/l concentration. The matrix salts involved have the same K + cation but different anions. Given a laser radiation emitting at 355 nm with the energy fixed at 23±1 mJ, a limit of detection (LOD) of 1.0 mg/l may be achieved for the Na analysis. The current normalization might have probably taken into account the ablated amount of the sample and the plasma temperature. Accordingly, the LIB/current correlated analysis becomes efficient to suppress the signal fluctuation, improve the LOD determination, and concurrently correct the matrix effect

Differential effects of gender on entropy perception

Science.gov (United States)

Satcharoen, Kleddao

2017-12-01

The purpose of this research is to examine differences in perception of entropy (color intensity) between male and female computer users. The objectives include identifying gender-based differences in entropy intention and exploring the potential effects of these differences (if any) on user interface design. The research is an effort to contribute to an emerging field of interest in gender as it relates to science, engineering and technology (SET), particularly user interface design. Currently, there is limited evidence on the role of gender in user interface design and in use of technology generally, with most efforts at gender-differentiated or customized design based on stereotypes and assumptions about female use of technology or the assumption of a default position based on male preferences. Image entropy was selected as a potential characteristic where gender could be a factor in perception because of known differences in color perception acuity between male and female individuals, even where there is no known color perception abnormality (which is more common with males). Although the literature review suggested that training could offset differences in color perception and identification, tests in untrained subject groups routinely show that females are more able to identify, match, and differentiate colors, and that there is a stronger emotional and psychosocial association of color for females. Since image entropy is associated with information content and image salience, the ability to identify areas of high entropy could make a difference in user perception and technological capabilities.

Harmonic effects of solar geomagnetically induced currents on the electrical distribution system in nuclear power plants

International Nuclear Information System (INIS)

Carroll, D.P.; Kasturi, S.; Subudhi, M.; Gunther, W.

1992-01-01

Most previous analysis on the effects of geomagnetically induced currents (GIC) on electric utility systems has steady-state phenomena, with the main interest in the generator step-up transformer and the off-site power system. This paper begins to investigate the possible effects that a GIC event might have on the power plant itself, by examining the harmonic distortion that could exist at various voltage levels in the on-site distribution system

Correction for Eddy Current-Induced Echo-Shifting Effect in Partial-Fourier Diffusion Tensor Imaging.

Science.gov (United States)

Truong, Trong-Kha; Song, Allen W; Chen, Nan-Kuei

2015-01-01

In most diffusion tensor imaging (DTI) studies, images are acquired with either a partial-Fourier or a parallel partial-Fourier echo-planar imaging (EPI) sequence, in order to shorten the echo time and increase the signal-to-noise ratio (SNR). However, eddy currents induced by the diffusion-sensitizing gradients can often lead to a shift of the echo in k-space, resulting in three distinct types of artifacts in partial-Fourier DTI. Here, we present an improved DTI acquisition and reconstruction scheme, capable of generating high-quality and high-SNR DTI data without eddy current-induced artifacts. This new scheme consists of three components, respectively, addressing the three distinct types of artifacts. First, a k-space energy-anchored DTI sequence is designed to recover eddy current-induced signal loss (i.e., Type 1 artifact). Second, a multischeme partial-Fourier reconstruction is used to eliminate artificial signal elevation (i.e., Type 2 artifact) associated with the conventional partial-Fourier reconstruction. Third, a signal intensity correction is applied to remove artificial signal modulations due to eddy current-induced erroneous T2(∗) -weighting (i.e., Type 3 artifact). These systematic improvements will greatly increase the consistency and accuracy of DTI measurements, expanding the utility of DTI in translational applications where quantitative robustness is much needed.

Induced current heating probe

International Nuclear Information System (INIS)

Thatcher, G.; Ferguson, B.G.; Winstanley, J.P.

1984-01-01

An induced current heating probe is of thimble form and has an outer conducting sheath and a water flooded flux-generating unit formed from a stack of ferrite rings coaxially disposed in the sheath. The energising coil is made of solid wire which connects at one end with a coaxial water current tube and at the other end with the sheath. The stack of ferrite rings may include non-magnetic insulating rings which help to shape the flux. (author)

Effects of Transverse Magnetic Anisotropy on Current-Induced Spin Switching

OpenAIRE

Misiorny, Maciej; Barnaś, Józef

2013-01-01

Spin-polarized transport through bistable magnetic adatoms or single-molecule magnets (SMMs), which exhibit both uniaxial and transverse magnetic anisotropy, is considered theoretically. The main focus is on the impact of transverse anisotropy on transport characteristics and the adatom's/SMM's spin. In particular, we analyze the role of quantum tunneling of magnetization (QTM) in the mechanism of the current-induced spin switching, and show that the QTM phenomenon becomes revealed as resonan...

Spin-flip scattering effect on the current-induced spin torque in ferromagnet-insulator-ferromagnet tunnel junctions

International Nuclear Information System (INIS)

Zhu Zhengang; Su Gang; Jin Biao; Zheng Qingrong

2003-01-01

We have investigated the current-induced spin transfer torque of a ferromagnet-insulator-ferromagnet tunnel junction by taking the spin-flip scatterings into account. It is found that the spin-flip scattering can induce an additional spin torque, enhancing the maximum of the spin torque and giving rise to an angular shift compared to the case when the spin-flip scatterings are neglected. The effects of the molecular fields of the left and right ferromagnets on the spin torque are also studied. It is found that τ Rx /I e (τ Rx is the spin-transfer torque acting on the right ferromagnet and I e is the tunneling electrical current) does vary with the molecular fields. At two certain angles, τ Rx /I e is independent of the molecular field of the right ferromagnet, resulting in two crossing points in the curve of τ Rx /I e versus the relevant orientation for different molecular fields

Teachers' Perceptions of Esri Story Maps as Effective Teaching Tools

Science.gov (United States)

Strachan, Caitlin; Mitchell, Jerry

2014-01-01

The current study explores teachers' perceptions of Esri Story Maps as effective teaching tools. Story Maps are a relatively new web application created using Esri's cloud-based GIS platform, ArcGIS Online. They combine digitized, dynamic web maps with other story elements to help the creator effectively convey a message. The relative ease…

Carbon monoxide induces cardiac arrhythmia via induction of the late Na+ current.

Science.gov (United States)

Dallas, Mark L; Yang, Zhaokang; Boyle, John P; Boycott, Hannah E; Scragg, Jason L; Milligan, Carol J; Elies, Jacobo; Duke, Adrian; Thireau, Jérôme; Reboul, Cyril; Richard, Sylvain; Bernus, Olivier; Steele, Derek S; Peers, Chris

2012-10-01

Clinical reports describe life-threatening cardiac arrhythmias after environmental exposure to carbon monoxide (CO) or accidental CO poisoning. Numerous case studies describe disruption of repolarization and prolongation of the QT interval, yet the mechanisms underlying CO-induced arrhythmias are unknown. To understand the cellular basis of CO-induced arrhythmias and to identify an effective therapeutic approach. Patch-clamp electrophysiology and confocal Ca(2+) and nitric oxide (NO) imaging in isolated ventricular myocytes was performed together with protein S-nitrosylation to investigate the effects of CO at the cellular and molecular levels, whereas telemetry was used to investigate effects of CO on electrocardiogram recordings in vivo. CO increased the sustained (late) component of the inward Na(+) current, resulting in prolongation of the action potential and the associated intracellular Ca(2+) transient. In more than 50% of myocytes these changes progressed to early after-depolarization-like arrhythmias. CO elevated NO levels in myocytes and caused S-nitrosylation of the Na(+) channel, Na(v)1.5. All proarrhythmic effects of CO were abolished by the NO synthase inhibitor l-NAME, and reversed by ranolazine, an inhibitor of the late Na(+) current. Ranolazine also corrected QT variability and arrhythmias induced by CO in vivo, as monitored by telemetry. Our data indicate that the proarrhythmic effects of CO arise from activation of NO synthase, leading to NO-mediated nitrosylation of Na(V)1.5 and to induction of the late Na(+) current. We also show that the antianginal drug ranolazine can abolish CO-induced early after-depolarizations, highlighting a novel approach to the treatment of CO-induced arrhythmias.

Polarity Specific Suppression Effects of Transcranial Direct Current Stimulation for Tinnitus

Directory of Open Access Journals (Sweden)

Kathleen Joos

2014-01-01

Full Text Available Tinnitus is the perception of a sound in the absence of an external auditory stimulus and affects 10–15% of the Western population. Previous studies have demonstrated the therapeutic effect of anodal transcranial direct current stimulation (tDCS over the left auditory cortex on tinnitus loudness, but the effect of this presumed excitatory stimulation contradicts with the underlying pathophysiological model of tinnitus. Therefore, we included 175 patients with chronic tinnitus to study polarity specific effects of a single tDCS session over the auditory cortex (39 anodal, 136 cathodal. To assess the effect of treatment, we used the numeric rating scale for tinnitus loudness and annoyance. Statistical analysis demonstrated a significant main effect for tinnitus loudness and annoyance, but for tinnitus annoyance anodal stimulation has a significantly more pronounced effect than cathodal stimulation. We hypothesize that the suppressive effect of tDCS on tinnitus loudness may be attributed to a disrupting effect of ongoing neural hyperactivity, independent of the inhibitory or excitatory effects and that the reduction of annoyance may be induced by influencing adjacent or functionally connected brain areas involved in the tinnitus related distress network. Further research is required to explain why only anodal stimulation has a suppressive effect on tinnitus annoyance.

Youth perceptions of alcohol advertising: are current advertising regulations working?

Science.gov (United States)

Aiken, Alexandra; Lam, Tina; Gilmore, William; Burns, Lucy; Chikritzhs, Tanya; Lenton, Simon; Lloyd, Belinda; Lubman, Dan; Ogeil, Rowan; Allsop, Steve

2018-06-01

We investigated young people's exposure to alcohol advertising, their intentions to consume and purchase alcohol products following the viewing of advertisements, and whether they perceived the actors in the advertisements as being under the age of 25 years. Face-to-face interviews were completed with 351 risky drinking 16-19-year-old Australians, with a sub-sample (n=68) responding to a range of alcohol advertisements in an in-depth interview. Participants were exposed to alcohol advertisements from an average of seven specific contexts in the past 12 months, with younger adolescents more likely to recall TV and outdoor billboards (n=351). Positive perception of advertisements was associated with increased intention to use and to purchase advertised products (n=68). A liqueur advertisement actor was perceived by 94% as being under 25 years-old, and almost 30% thought the advertisement was marketed at people younger than 18 years of age. Young people's perceptions of alcohol advertising are not necessarily in line with expert/industry assessment; products are sometimes marketed in a way that is highly appealing to young people. Greater appeal was associated with increased intention to consume and to purchase products. Implications for public health: These results indicate deficiencies in the effectiveness of current advertising codes in regard to protecting the health and wellbeing of adolescents. © 2018 The Authors.

Neck proprioception shapes body orientation and perception of motion.

Science.gov (United States)

Pettorossi, Vito Enrico; Schieppati, Marco

2014-01-01

This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead (SSA), and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers. We first remind the early findings on human balance, gait trajectory, SSA, induced by limb, and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, SSA, and walking trajectory. Neck vibration also induces persistent aftereffects on the SSA and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck-proprioceptive input may induce persistent influences on the subject's mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes.

PROCESSORS’ PERCEPTION OF THE EFFECTIVENESS OF SOME CASSAVA PROCESSING INNOVATIONS IN OGUN STATE, NIGERIA

OpenAIRE

Adebayo, K.; Sangosina, M.A.

2005-01-01

The current drive towards higher levels of commercialisation of cassava processing under the Presidential Initiative on Cassava requires that the scale of cassava processing be increased in Nigeria. Primary data obtained from 112 respondents selected from the 4 extension zones of Ogun State was used to examine the perception of effectiveness of innovations by cassava processors and the factors responsible for adoption of these innovations. The processors’ perception of effectiveness of cassav...

How does relativity affect magnetically induced currents?

Science.gov (United States)

Berger, R J F; Repisky, M; Komorovsky, S

2015-09-21

Magnetically induced probability currents in molecules are studied in relativistic theory. Spin-orbit coupling (SOC) enhances the curvature and gives rise to a previously unobserved current cusp in AuH or small bulge-like distortions in HgH2 at the proton positions. The origin of this curvature is magnetically induced spin-density arising from SOC in the relativistic description.

Exposure to arousal-inducing sounds facilitates visual search.

Science.gov (United States)

Asutay, Erkin; Västfjäll, Daniel

2017-09-04

Exposure to affective stimuli could enhance perception and facilitate attention via increasing alertness, vigilance, and by decreasing attentional thresholds. However, evidence on the impact of affective sounds on perception and attention is scant. Here, a novel aspect of affective facilitation of attention is studied: whether arousal induced by task-irrelevant auditory stimuli could modulate attention in a visual search. In two experiments, participants performed a visual search task with and without auditory-cues that preceded the search. Participants were faster in locating high-salient targets compared to low-salient targets. Critically, search times and search slopes decreased with increasing auditory-induced arousal while searching for low-salient targets. Taken together, these findings suggest that arousal induced by sounds can facilitate attention in a subsequent visual search. This novel finding provides support for the alerting function of the auditory system by showing an auditory-phasic alerting effect in visual attention. The results also indicate that stimulus arousal modulates the alerting effect. Attention and perception are our everyday tools to navigate our surrounding world and the current findings showing that affective sounds could influence visual attention provide evidence that we make use of affective information during perceptual processing.

Improving speech perception in noise with current focusing in cochlear implant users.

Science.gov (United States)

Srinivasan, Arthi G; Padilla, Monica; Shannon, Robert V; Landsberger, David M

2013-05-01

Cochlear implant (CI) users typically have excellent speech recognition in quiet but struggle with understanding speech in noise. It is thought that broad current spread from stimulating electrodes causes adjacent electrodes to activate overlapping populations of neurons which results in interactions across adjacent channels. Current focusing has been studied as a way to reduce spread of excitation, and therefore, reduce channel interactions. In particular, partial tripolar stimulation has been shown to reduce spread of excitation relative to monopolar stimulation. However, the crucial question is whether this benefit translates to improvements in speech perception. In this study, we compared speech perception in noise with experimental monopolar and partial tripolar speech processing strategies. The two strategies were matched in terms of number of active electrodes, microphone, filterbanks, stimulation rate and loudness (although both strategies used a lower stimulation rate than typical clinical strategies). The results of this study showed a significant improvement in speech perception in noise with partial tripolar stimulation. All subjects benefited from the current focused speech processing strategy. There was a mean improvement in speech recognition threshold of 2.7 dB in a digits in noise task and a mean improvement of 3 dB in a sentences in noise task with partial tripolar stimulation relative to monopolar stimulation. Although the experimental monopolar strategy was worse than the clinical, presumably due to different microphones, frequency allocations and stimulation rates, the experimental partial-tripolar strategy, which had the same changes, showed no acute deficit relative to the clinical. Copyright © 2013 Elsevier B.V. All rights reserved.

Neck proprioception shapes body orientation and perception of motion

Directory of Open Access Journals (Sweden)

Vito Enrico Pettorossi

2014-11-01

Full Text Available This review article deals with some effects of neck muscle proprioception on human balance, gait trajectory, subjective straight-ahead, and self-motion perception. These effects are easily observed during neck muscle vibration, a strong stimulus for the spindle primary afferent fibers.We first remind the early findings on human balance, gait trajectory, subjective straight-ahead, induced by limb and neck muscle vibration. Then, more recent findings on self-motion perception of vestibular origin are described. The use of a vestibular asymmetric yaw-rotation stimulus for emphasizing the proprioceptive modulation of motion perception from the neck is mentioned. In addition, an attempt has been made to conjointly discuss the effects of unilateral neck proprioception on motion perception, subjective straight-ahead and walking trajectory.Neck vibration also induces persistent aftereffects on the subjective straight-ahead and on self-motion perception of vestibular origin. These perceptive effects depend on intensity, duration, side of the conditioning vibratory stimulation, and on muscle status. These effects can be maintained for hours when prolonged high-frequency vibration is superimposed on muscle contraction. Overall, this brief outline emphasizes the contribution of neck muscle inflow to the construction and fine-tuning of perception of body orientation and motion. Furthermore, it indicates that tonic neck proprioceptive input may induce persistent influences on the subject's mental representation of space. These plastic changes might adapt motion sensitiveness to lasting or permanent head positional or motor changes.

Equity perceptions and marital satisfaction in former and current marriage: A study among the remarried

NARCIS (Netherlands)

Buunk, A.P.; Mutsaers, W

A study among 290 remarried individuals examined equity perceptions in the former and the current marriage. The results showed that equity in the former and the current marriage were not related to each other. In general, respondents perceived much more inequity in the former than in the current

The coupling of mechanical dynamics and induced currents in plates and surfaces

International Nuclear Information System (INIS)

Weissenburger, D.W.; Bialek, J.M.

1986-10-01

Significant mechanical reactions and deflections may be produced when electrical eddy currents induced in a conducting structure by transformer-like electromotive forces interact with background magnetic fields. Additional eddy currents induced by structural motion through the background fields modify both the mechanical and electrical dynamic behavior of the system. The observed effects of these motional eddy currents are sometimes referred to as magnetic damping and magnetic stiffness. This paper addresses the coupled structural deformation and eddy currents in flat plates and simple two-dimensional surfaces in three-space. A coupled system of equations has been formulated using finite element techniques for the mechanical aspects and a mesh network method for the electrical aspects of the problem

Being watched: the effect of social self-focus on interoceptive and exteroceptive somatosensory perception.

Science.gov (United States)

Durlik, Caroline; Cardini, Flavia; Tsakiris, Manos

2014-04-01

We become aware of our bodies interoceptively, by processing signals arising from within the body, and exteroceptively, by processing signals arising on or outside the body. Recent research highlights the importance of the interaction of exteroceptive and interoceptive signals in modulating bodily self-consciousness. The current study investigated the effect of social self-focus, manipulated via a video camera that was facing the participants and that was either switched on or off, on interoceptive sensitivity (using a heartbeat perception task) and on tactile perception (using the Somatic Signal Detection Task (SSDT)). The results indicated a significant effect of self-focus on SSDT performance, but not on interoception. SSDT performance was not moderated by interoceptive sensitivity, although interoceptive sensitivity scores were positively correlated with false alarms, independently of self-focus. Together with previous research, our results suggest that self-focus may exert different effects on body perception depending on its mode (private versus social). While interoception has been previously shown to be enhanced by private self-focus, the current study failed to find an effect of social self-focus on interoceptive sensitivity, instead demonstrating that social self-focus improves exteroceptive somatosensory processing. Copyright © 2014 Elsevier Inc. All rights reserved.

Coupled Dzyaloshinskii walls and their current-induced dynamics by the spin Hall effect

Energy Technology Data Exchange (ETDEWEB)

Martínez, Eduardo, E-mail: edumartinez@usal.es [Dpto. de Fisica Aplicada, Universidad de Salamanca, Plaza de los Caídos s/n, E-37008 Salamanca (Spain); Alejos, Óscar [Dpto. de Electricidad y Electrónica, Universidad de Valladolid, Paseo de Belén, 7, E-47011 Valladolid (Spain)

2014-07-14

The nucleation of domain walls in ultrathin ferromagnetic/heavy-metal bilayers is studied by means of micromagnetic simulations. In the presence of interfacial Dzyaloshinskii-Moriya interaction, the nucleated walls naturally adopt a homochiral configuration with internal magnetization pointing antiparallely. The interaction between these walls was analyzed and described in terms of a classical dipolar force between the magnetic moments of the walls, which couples their dynamics. Additionally, the current-induced motion of two homochiral walls in the presence of longitudinal fields was also studied by means of a simple one-dimensional model and micromagnetic modeling, considering both one free-defect strip and another one with random edge roughness. It is evidenced that in the presence of pinning due to edge roughness, the in-plane longitudinal field introduces an asymmetry in the current-induced depinning, in agreement with recent experimental results.

Coupled Dzyaloshinskii walls and their current-induced dynamics by the spin Hall effect

International Nuclear Information System (INIS)

Martínez, Eduardo; Alejos, Óscar

2014-01-01

The nucleation of domain walls in ultrathin ferromagnetic/heavy-metal bilayers is studied by means of micromagnetic simulations. In the presence of interfacial Dzyaloshinskii-Moriya interaction, the nucleated walls naturally adopt a homochiral configuration with internal magnetization pointing antiparallely. The interaction between these walls was analyzed and described in terms of a classical dipolar force between the magnetic moments of the walls, which couples their dynamics. Additionally, the current-induced motion of two homochiral walls in the presence of longitudinal fields was also studied by means of a simple one-dimensional model and micromagnetic modeling, considering both one free-defect strip and another one with random edge roughness. It is evidenced that in the presence of pinning due to edge roughness, the in-plane longitudinal field introduces an asymmetry in the current-induced depinning, in agreement with recent experimental results.

Current-Induced Forces and Hot Spots in Biased Nanojunctions

DEFF Research Database (Denmark)

Lu, Jing Tao; Christensen, Rasmus Bjerregaard; Wang, Jian-Sheng

2015-01-01

We investigate theoretically the interplay of current-induced forces (CIFs), Joule heating, and heat transport inside a current-carrying nanoconductor. We find that the CIFs, due to the electron-phonon coherence, can control the spatial heat dissipation in the conductor. This yields a significant...... asymmetric concentration of excess heating (hot spot) even for a symmetric conductor. When coupled to the electrode phonons, CIFs drive different phonon heat flux into the two electrodes. First-principles calculations on realistic biased nanojunctions illustrate the importance of the effect....

Hysteresis in audiovisual synchrony perception.

Directory of Open Access Journals (Sweden)

Jean-Rémy Martin

Full Text Available The effect of stimulation history on the perception of a current event can yield two opposite effects, namely: adaptation or hysteresis. The perception of the current event thus goes in the opposite or in the same direction as prior stimulation, respectively. In audiovisual (AV synchrony perception, adaptation effects have primarily been reported. Here, we tested if perceptual hysteresis could also be observed over adaptation in AV timing perception by varying different experimental conditions. Participants were asked to judge the synchrony of the last (test stimulus of an AV sequence with either constant or gradually changing AV intervals (constant and dynamic condition, respectively. The onset timing of the test stimulus could be cued or not (prospective vs. retrospective condition, respectively. We observed hysteretic effects for AV synchrony judgments in the retrospective condition that were independent of the constant or dynamic nature of the adapted stimuli; these effects disappeared in the prospective condition. The present findings suggest that knowing when to estimate a stimulus property has a crucial impact on perceptual simultaneity judgments. Our results extend beyond AV timing perception, and have strong implications regarding the comparative study of hysteresis and adaptation phenomena.

Effect of transcranial direct current stimulation on vestibular-ocular and vestibulo-perceptual thresholds.

Science.gov (United States)

Kyriakareli, Artemis; Cousins, Sian; Pettorossi, Vito E; Bronstein, Adolfo M

2013-10-02

Transcranial direct current stimulation (tDCS) was used in 17 normal individuals to modulate vestibulo-ocular reflex (VOR) and self-motion perception rotational thresholds. The electrodes were applied over the temporoparietal junction bilaterally. Both vestibular nystagmic and perceptual thresholds were increased during as well as after tDCS stimulation. Body rotation was labeled as ipsilateral or contralateral to the anode side, but no difference was observed depending on the direction of rotation or hemisphere polarity. Threshold increase during tDCS was greater for VOR than for motion perception. 'Sham' stimulation had no effect on thresholds. We conclude that tDCS produces an immediate and sustained depression of cortical regions controlling VOR and movement perception. Temporoparietal areas appear to be involved in vestibular threshold modulation but the differential effects observed between VOR and perception suggest a partial dissociation between cortical processing of reflexive and perceptual responses.

Modulation of Perception or Emotion? A Scoping Review of Tinnitus Neuromodulation Using Transcranial Direct Current Stimulation.

Science.gov (United States)

Shekhawat, Giriraj Singh; Stinear, Cathy M; Searchfield, Grant D

2015-10-01

Tinnitus is the phantom perception of sound and can have negative effect on the quality of life. Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation technique, which can increase or decrease the cortical excitability in the brain region to which it is applied. tDCS has been used for tinnitus research since 2006. To investigate whether tDCS affects tinnitus perception, related emotion, or both, and the potential implications for tinnitus management. A scoping review was undertaken using the methods proposed by Arksey and O'Malley. After initial consideration of title relevance and reading abstracts, 15 studies were included in this review. The data from these studies were charted to investigate the impact of tDCS on tinnitus perception and emotions. tDCS results in transient suppression of tinnitus loudness and annoyance; however, it does not lead to long-term impact on tinnitus related emotion. Local stimulation of different sites of stimulation (left temporoparietal area, dorsolateral prefrontal cortex, and auditory cortex) might modulate tinnitus perception (loudness) and emotions differently; however, further research is needed to explore this hypothesis. This review has identified aspects of methodologies that require attention in upcoming tinnitus and tDCS trials to offer better insights. tDCS is an effective research tool for transient tinnitus neuromodulation. However, efforts should be invested in designing clinical trials using local and multiple sites of stimulation, optimized parameters, and objective outcome measures before it can be translated in to a clinical tool for tinnitus management. © The Author(s) 2015.

Neutron induced current pulses in fission chambers

International Nuclear Information System (INIS)

Taboas, A.L.; Buck, W.L.

1978-01-01

The mechanism of neutron induced current pulse generation in fission chambers is discussed. By application of the calculated detector transfer function to proposed detector current pulse shapes, and by comparison with actually observed detector output voltage pulses, a credible, semi-empirical, trapezoidal pulse shape of chamber current is obtained

Current-induced domain wall motion: Separating spin torque and Oersted-field effects in Co/Pt nanowires

Energy Technology Data Exchange (ETDEWEB)

Heinen, Jan; Boulle, Olivier; Rousseau, Kevin; Malinowski, Gregory; Klaeui, Mathias [Universitaet Konstanz, Fachbereich Physik, D-78457 Konstanz (Germany); Swagton, Henk J.; Koopmans, Bert [Eindhoven University of Technology, Department of Applied Physics, MB 5600 (Netherlands); Ulysse, Christian; Faini, Giancarlo [CNRS, Phynano team, Laboratoire de Photonique et de Nanostructures, 91460 Marcoussis (France)

2010-07-01

We report on magnetotransport studies on perpendicularly magnetized nanowires with narrow domain wall (DW) structures. Using Co/Pt multilayer nanowires, we have previously shown that Joule heating is concealing most of the current induced domain wall effects, but using a constant sample temperature a large non-adiabacity factor {beta} has been deduced. Here, we carry out experiments for both applied field directions and current polarities, starting from different DW configurations within a Hall cross. We clearly show, using the different symmetries of spin torque and Oersted-field, that the much debated Oersted-field does not contribute to the DW depinning significantly. This allows us to extract the spin torque contribution and the non-adiabacity factor {beta}, which turns out to be in line with previous measurements.

On Current Drive and Wave Induced Bootstrap Current in Toroidal Plasmas

International Nuclear Information System (INIS)

Hellsten, T.; Johnson, T.

2008-01-01

A comprehensive treatment of wave-particle interactions in toroidal plasmas including collisional relaxation, applicable to heating or anomalous wave induced transport, has been obtained by using Monte Carlo operators satisfying quasi-neutrality. This approach enables a self-consistent treatment of wave-particle interactions applicable to the banana regime in the neoclassical theory. It allows an extension into a regime with large temperature and density gradients, losses and transport of particles by wave-particle interactions making the method applicable to transport barriers. It is found that at large gradients the relationship between radial electric field, parallel velocity, temperature and density gradient in the neoclassical theory is modified such that coefficient in front of the logarithmic ion temperature gradient, which in the standard neoclassical theory is small and counteracts the electric field caused by the density gradient, now changes sign and contributes to the built up of the radial electric field. The possibility to drive current by absorbing the waves on trapped particles has been studied and how the wave-particle interactions affect the bootstrap current. Two new current drive mechanisms are studied: current drive by wave induced bootstrap current and selective detrapping into passing orbits by directed waves.

Effect of head pitch and roll orientations on magnetically induced vertigo.

Science.gov (United States)

Mian, Omar S; Li, Yan; Antunes, Andre; Glover, Paul M; Day, Brian L

2016-02-15

Lying supine in a strong magnetic field, such as in magnetic resonance imaging scanners, can induce a perception of whole-body rotation. The leading hypothesis to explain this invokes a Lorentz force mechanism acting on vestibular endolymph that acts to stimulate semicircular canals. The hypothesis predicts that the perception of whole-body rotation will depend on head orientation in the field. Results showed that the direction and magnitude of apparent whole-body rotation while stationary in a 7 T magnetic field is influenced by head orientation. The data are compatible with the Lorentz force hypothesis of magnetic vestibular stimulation and furthermore demonstrate the operation of a spatial transformation process from head-referenced vestibular signals to Earth-referenced body motion. High strength static magnetic fields are known to induce vertigo, believed to be via stimulation of the vestibular system. The leading hypothesis (Lorentz forces) predicts that the induced vertigo should depend on the orientation of the magnetic field relative to the head. In this study we examined the effect of static head pitch (-80 to +40 deg; 12 participants) and roll (-40 to +40 deg; 11 participants) on qualitative and quantitative aspects of vertigo experienced in the dark by healthy humans when exposed to the static uniform magnetic field inside a 7 T MRI scanner. Three participants were additionally examined at 180 deg pitch and roll orientations. The effect of roll orientation on horizontal and vertical nystagmus was also measured and was found to affect only the vertical component. Vertigo was most discomforting when head pitch was around 60 deg extension and was mildest when it was around 20 deg flexion. Quantitative analysis of vertigo focused on the induced perception of horizontal-plane rotation reported online with the aid of hand-held switches. Head orientation had effects on both the magnitude and the direction of this perceived rotation. The data suggest

Revisiting Antipsychotic-induced Akathisia: Current Issues and Prospective Challenges

Science.gov (United States)

Salem, Haitham; Nagpal, Caesa; Pigott, Teresa; Teixeira, Antonio Lucio

2017-01-01

Background: Akathisia continues to be a significant challenge in current neurological and psychiatric practice. Prompt and accurate detection is often difficult and there is a lack of consensus concerning the neurobiological basis of akathisia. No definitive treatment has been established for akathisia despite numerous preclinical and clinical studies. Method: We reviewed antipsychotic-induced akathisia including its clinical presentation, proposed underlying pathophysiology, current and under investigation therapeutic strategies. Conclusion: Despite the initial promise that second generation antipsychotics would be devoid of akathisia effects, this has not been confirmed. Currently, there are limited therapeutic options for the clinical practice and the evidence supporting the most widely used treatments (beta blockers, anticholinergic drugs) is still absent or inconsistent. PMID:27928948

Teachers' Autonomy in Today's Educational Climate: Current Perceptions from an Acceptable Instrument

Science.gov (United States)

Strong, Luman E. G.; Yoshida, Roland K.

2014-01-01

This research evaluated the psychometric properties of Friedman's (1999) Teacher Work-Autonomy Scale (TWA) to determine whether it was an acceptable instrument to measure U.S. teacher autonomy in the present educational context. A second purpose was to ascertain the current status of teachers' perceptions of their autonomy from a sample of U.S.…

Theory of in-plane current induced spin torque in metal/ferromagnet bilayers

Science.gov (United States)

Sakanashi, Kohei; Sigrist, Manfred; Chen, Wei

2018-05-01

Using a semiclassical approach that simultaneously incorporates the spin Hall effect (SHE), spin diffusion, quantum well states, and interface spin–orbit coupling (SOC), we address the interplay of these mechanisms as the origin of the spin–orbit torque (SOT) induced by in-plane currents, as observed in the normal metal/ferromagnetic metal bilayer thin films. Focusing on the bilayers with a ferromagnet much thinner than its spin diffusion length, such as Pt/Co with  ∼10 nm thickness, our approach addresses simultaneously the two contributions to the SOT, namely the spin-transfer torque (SHE-STT) due to SHE-induced spin injection, and the inverse spin Galvanic effect spin–orbit torque (ISGE-SOT) due to SOC-induced spin accumulation. The SOC produces an effective magnetic field at the interface, hence it modifies the angular momentum conservation expected for the SHE-STT. The SHE-induced spin voltage and the interface spin current are mutually dependent and, hence, are solved in a self-consistent manner. The result suggests that the SHE-STT and ISGE-SOT are of the same order of magnitude, and the spin transport mediated by the quantum well states may be an important mechanism for the experimentally observed rapid variation of the SOT with respect to the thickness of the ferromagnet.

The effects of transcranial direct current stimulation on conscious perception of sensory inputs from hand palm and dorsum.

Science.gov (United States)

Westgeest, Annette; Morales, Merche; Cabib, Christopher; Valls-Sole, Josep

2014-12-01

Conscious perception of sensory signals depends in part on stimulus salience, relevance and topography. Letting aside differences at skin receptor level and afferent fibres, it is the CNS that makes a contextual selection of relevant sensory inputs. We hypothesized that subjective awareness (AW) of the time at which a sensory stimulus is perceived, a cortical function, may be differently modified by cortical stimulation, according to site and type of the stimulus. In 24 healthy volunteers, we examined the effects of transcranial direct current stimulation (tDCS) on the assessment of AW to heat pain or weak electrical stimuli applied to either the hand palm or dorsum. We also recorded the vertex-evoked potentials to the same stimuli. The assessment was done before, during and after cathodal or anodal tDCS over the parietal cortex contralateral to the hand receiving the stimuli. At baseline, AW to thermal stimuli was significantly longer for palm than for dorsum (P sensory inputs. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

GABAB receptor phosphorylation regulates KCTD12-induced K+ current desensitization

DEFF Research Database (Denmark)

Adelfinger, L; Turecek, R; Ivankova, K

2014-01-01

released from the G-protein. Receptor-activated K+ currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K+ currents integrates distinct mechanistic underpinnings. GABAB receptor activity reduces protein kinase-A activity, which...... reduces phosphorylation of serine-892 in GABAB2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G......-protein βγ subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast...

Long-term effects of serial anodal tDCS on motion perception in subjects with occipital stroke measured in the unaffected visual hemifield

Directory of Open Access Journals (Sweden)

Manuel C Olma

2013-06-01

Full Text Available Transcranial direct current stimulation (tDCS is a novel neuromodulatory tool that has seen early transition to clinical trials, although the high variability of these findings necessitates further studies in clincally-relevant populations. The majority of evidence into effects of repeated tDCS is based on research in the human motor system, but it is unclear whether the long-term effects of serial tDCS are motor-specific or transferable to other brain areas. This study aimed to examine whether serial anodal tDCS over the visual cortex can exogenously induce long-term neuroplastic changes in the visual cortex. However, when the visual cortex is affected by a cortical lesion, up-regulated endogenous neuroplastic adaptation processes may alter the susceptibility to tDCS. To this end, motion perception was investigated in the unaffected hemifield of subjects with unilateral visual cortex lesions. Twelve subjects with occipital ischaemic lesions participated in a within-subject, sham-controlled, double-blind study. MRI-registered sham or anodal tDCS (1.5 mA, 20 minutes was applied on five consecutive days over the visual cortex. Motion perception was tested before and after stimulation sessions and at 14- and 28-day follow-up. After a 16-day interval an identical study block with the other stimulation condition (anodal or sham tDCS followed. Serial anodal tDCS over the visual cortex resulted in an improvement in motion perception, a function attributed to MT/V5. This effect was still measurable at 14- and 28-day follow-up measurements. Thus, this may represent evidence for long-term tDCS-induced plasticity and has implications for the design of studies examining the time course of tDCS effects in both the visual and motor systems.

Bodily action penetrates affective perception

Science.gov (United States)

Rigutti, Sara; Gerbino, Walter

2016-01-01

Fantoni & Gerbino (2014) showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP), they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015) would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification) task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions), in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top-down effect on

Bodily action penetrates affective perception

Directory of Open Access Journals (Sweden)

Carlo Fantoni

2016-02-01

Full Text Available Fantoni & Gerbino (2014 showed that subtle postural shifts associated with reaching can have a strong hedonic impact and affect how actors experience facial expressions of emotion. Using a novel Motor Action Mood Induction Procedure (MAMIP, they found consistent congruency effects in participants who performed a facial emotion identification task after a sequence of visually-guided reaches: a face perceived as neutral in a baseline condition appeared slightly happy after comfortable actions and slightly angry after uncomfortable actions. However, skeptics about the penetrability of perception (Zeimbekis & Raftopoulos, 2015 would consider such evidence insufficient to demonstrate that observer’s internal states induced by action comfort/discomfort affect perception in a top-down fashion. The action-modulated mood might have produced a back-end memory effect capable of affecting post-perceptual and decision processing, but not front-end perception. Here, we present evidence that performing a facial emotion detection (not identification task after MAMIP exhibits systematic mood-congruent sensitivity changes, rather than response bias changes attributable to cognitive set shifts; i.e., we show that observer’s internal states induced by bodily action can modulate affective perception. The detection threshold for happiness was lower after fifty comfortable than uncomfortable reaches; while the detection threshold for anger was lower after fifty uncomfortable than comfortable reaches. Action valence induced an overall sensitivity improvement in detecting subtle variations of congruent facial expressions (happiness after positive comfortable actions, anger after negative uncomfortable actions, in the absence of significant response bias shifts. Notably, both comfortable and uncomfortable reaches impact sensitivity in an approximately symmetric way relative to a baseline inaction condition. All of these constitute compelling evidence of a genuine top

Climate-Induced Boreal Forest Change: Predictions versus Current Observations

Science.gov (United States)

Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

2007-01-01

For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

Current-induced Rashba spin orbit torque in silicene

Energy Technology Data Exchange (ETDEWEB)

Chen, Ji, E-mail: muze7777@hdu.edu.cn [Department of Mathematics, School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Peng, Yingzi [Department of Physics, School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China); Center for Integrated Spintronic Devices, Hangzhou Dianzi University, Hangzhou 310018 (China); Zhou, Jie [Department of Mathematics, School of Science, Hangzhou Dianzi University, Hangzhou 310018 (China)

2017-06-15

Highlights: • The spin dynamics of a ferromagnetic layer coupled to a silicene is investigated. • The Rashba spin orbit torque is obtained and the well-known LLG equation is modified. • The explicit forms of spin orbit torques in Domain Wall and vortex is also obtained. - Abstract: We study theoretically the spin torque of a ferromagnetic layer coupled to a silicene in the presence of the intrinsic Rashba spin orbit coupling (RSOC) effect. By using gauge field method, we find that under the applied current, the RSOC can induce an effective field which will result in the spin precession of conduction electron without applying any magnetic field. We also derive the spin torques due to the RSOC, which generalize the Landau-Lifshitz-Gilbert (LLG) equation. The spin torques are related to the applied current, the carrier density and Rashba strength of the system.

Radiation induced leakage current and stress induced leakage current in ultra-thin gate oxides

International Nuclear Information System (INIS)

Ceschia, M.; Paccagnella, A.; Cester, A.; Scarpa, A.

1998-01-01

Low-field leakage current has been measured in thin oxides after exposure to ionizing radiation. This Radiation Induced Leakage Current (RILC) can be described as an inelastic tunneling process mediated by neutral traps in the oxide, with an energy loss of about 1 eV. The neutral trap distribution is influenced by the oxide field applied during irradiation, thus indicating that the precursors of the neutral defects are charged, likely being defects associated to trapped holes. The maximum leakage current is found under zero-field condition during irradiation, and it rapidly decreases as the field is enhanced, due to a displacement of the defect distribution across the oxide towards the cathodic interface. The RILC kinetics are linear with the cumulative dose, in contrast with the power law found on electrically stressed devices

Action potential influences spatial perception: Evidence for genuine top-down effects on perception.

Science.gov (United States)

Witt, Jessica K

2017-08-01

The action-specific account of spatial perception asserts that a perceiver's ability to perform an action, such as hitting a softball or walking up a hill, impacts the visual perception of the target object. Although much evidence is consistent with this claim, the evidence has been challenged as to whether perception is truly impacted, as opposed to the responses themselves. These challenges have recently been organized as six pitfalls that provide a framework with which to evaluate the empirical evidence. Four case studies of action-specific effects are offered as evidence that meets the framework's high bar, and thus that demonstrates genuine perceptual effects. That action influences spatial perception is evidence that perceptual and action-related processes are intricately and bidirectionally linked.

Effect of semiconductor GaAs laser irradiation on pain perception in mice

Energy Technology Data Exchange (ETDEWEB)

Zarkovic, N.; Manev, H.; Pericic, D.; Skala, K.; Jurin, M.; Persin, A.; Kubovic, M.

1989-01-01

The influence of subacute exposure (11 exposures within 16 days) of mice to the low power (GaAs) semiconductive laser-stimulated irradiation on pain perception was investigated. The pain perception was determined by the latency of foot-licking or jumping from the surface of a 53 degrees C hot plate. Repeated hot-plate testing resulted in shortening of latencies in both sham- and laser-irradiated mice. Laser treatment (wavelength, 905 nm; frequency, 256 Hz; irradiation time, 50 sec; pulse duration, 100 nsec; distance, 3 cm; peak irradiance, 50 W/cm2 in irradiated area; and total exposure, 0.41 mJ/cm2) induced further shortening of latencies, suggesting its stimulatory influence on pain perception. Administration of morphine (20 mg/kg) prolonged the latency of response to the hot plate in both sham- and laser-irradiated mice. This prolongation tended to be lesser in laser-irradiated animals. Further investigations are required to elucidate the mechanism of the observed effect of laser.

Ambiguity in Tactile Apparent Motion Perception.

Directory of Open Access Journals (Sweden)

Emanuela Liaci

Full Text Available In von Schiller's Stroboscopic Alternative Motion (SAM stimulus two visually presented diagonal dot pairs, located on the corners of an imaginary rectangle, alternate with each other and induce either horizontal, vertical or, rarely, rotational motion percepts. SAM motion perception can be described by a psychometric function of the dot aspect ratio ("AR", i.e. the relation between vertical and horizontal dot distances. Further, with equal horizontal and vertical dot distances (AR = 1 perception is biased towards vertical motion. In a series of five experiments, we presented tactile SAM versions and studied the role of AR and of different reference frames for the perception of tactile apparent motion.We presented tactile SAM stimuli and varied the ARs, while participants reported the perceived motion directions. Pairs of vibration stimulators were attached to the participants' forearms and stimulator distances were varied within and between forearms. We compared straight and rotated forearm conditions with each other in order to disentangle the roles of exogenous and endogenous reference frames.Increasing the tactile SAM's AR biased perception towards vertical motion, but the effect was weak compared to the visual modality. We found no horizontal disambiguation, even for very small tactile ARs. A forearm rotation by 90° kept the vertical bias, even though it was now coupled with small ARs. A 45° rotation condition with crossed forearms, however, evoked a strong horizontal motion bias.Existing approaches to explain the visual SAM bias fail to explain the current tactile results. Particularly puzzling is the strong horizontal bias in the crossed-forearm conditions. In the case of tactile apparent motion, there seem to be no fixed priority rule for perceptual disambiguation. Rather the weighting of available evidence seems to depend on the degree of stimulus ambiguity, the current situation and on the perceptual strategy of the individual

Disentangling the effect of illness perceptions on health status in people with type 2 diabetes after an acute coronary event.

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Vos, Rimke Cathelijne; Kasteleyn, Marise Jeannine; Heijmans, Monique Johanna; de Leeuw, Elke; Schellevis, François Georges; Rijken, Mieke; Rutten, Guy Emile

2018-03-02

Chronically ill patients such as people with type 2 diabetes develop perceptions of their illness, which will influence their coping behaviour. Perceptions are formed once a health threat has been recognised. Many people with type 2 diabetes suffer from multimorbidity, for example the combination with cardiovascular disease. Perceptions of one illness may influence perceptions of the other condition. The aim of the current study was to evaluate the effect of an intervention in type 2 diabetes patients with a first acute coronary event on change in illness perceptions and whether this mediates the intervention effect on health status. The current study is a secondary data analysis of a RCT. Two hundred one participants were randomised (1:1 ratio) to the intervention (n = 101, three home visits) or control group (n = 100). Outcome variables were diabetes and acute coronary event perceptions, assessed with the two separate Brief Illness Perceptions Questionnaires (BIPQs); and health status (Euroqol Visual Analog Scale (EQ-VAS)). The intervention effect was analysed using ANCOVA. Linear regression analyses were used to assess whether illness perceptions mediated the intervention effect on health status. A positive intervention effect was found on the BIPQ diabetes items coherence and treatment control (F = 8.19, p = 0.005; F = 14.01, p effect was found on the other BIPQ diabetes items consequence, personal control, identity, illness concern and emotional representation. Regarding the acute coronary event, a positive intervention effect on treatment control was found (F = 7.81, p = 0.006). No intervention effect was found on the other items of the acute coronary event BIPQ. Better diabetes coherence was associated with improved health status, whereas perceiving more treatment control was not. The mediating effect of the diabetes perception 'coherence' on health status was not significant. Targeting illness perceptions of people with

Evidence of a New Current-Induced Magnetoelectric Effect in a Toroidal Magnetic Ordered State of UNi4B

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Saito, Hiraku; Uenishi, Kenta; Miura, Naoyuki; Tabata, Chihiro; Hidaka, Hiroyuki; Yanagisawa, Tatsuya; Amitsuka, Hiroshi

2018-03-01

Magnetization measurements under direct electric current were performed in a toroidal magnetic ordered state of UNi4B to test a recent theoretical prediction of current-induced magnetization in a metallic system lacking local-inversion symmetry. We found that electric current parallel to [2\\bar{1}\\bar{1}0] and [0001] in the hexagonal 4-index notation induces a uniform magnetization along the [01\\bar{1}0] direction. The observed behavior of the induced magnetization is essentially consistent with the theoretical prediction; however, it also shows an inconsistency suggesting that the antiferromagnetic state of UNi4B could not be simply regarded as a uniform toroidal order in the ideal honeycomb layered structure.

The effect of a medical opinion on self-perceptions of weight for Mexican adults: perception of change and cognitive biases.

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Easton, Jonathan F; Stephens, Christopher R; Román Sicilia, Heriberto

2017-01-01

This study analysed the relationship between perceived and actual Body Mass Index (BMI) and the effect of a prior identification of obesity by a medical professional for adults using difference in response for two distinct BMI self-perception questions. Typically, self-perception studies only investigate the relation with current weight, whereas here the focus is on the self-perception of weight differences. A statistical approach was used to assess responses to the Mexican ENSANUT 2006 survey. Adults in the range of BMI from 13 to 60 were tested on responses to a categorical question and a figure rating scale self-perception question. Differences in response by gender and identification of obesity by a medical professional were analysed using linear regression. Results indicated that regardless of current BMI and gender, a verbal intervention by a medical professional will increase perceived BMI independently of actual BMI but does not necessarily make the identified obese more accurate in their BMI estimates. A shift in the average self-perception was seen with a higher response for the identified obese. A linear increase in perceived BMI as a function of actual BMI was observed in the range BMI self-image, to be considerably less. It was seen that an identification of obesity by a health care professional did not improve ability to judge weight but, rather, served as a new anchor from which the identified obese judge their weight, suggesting that even those identified obese who have lost weight, perceive their weight to be greater than it actually is. We believe that these results can be explained in terms of two cognitive biases; the self-serving bias and the anchoring bias.

Computer simulation of induced electric currents and fields in biological bodies by 60 Hz magnetic fields

International Nuclear Information System (INIS)

Xi Weiguo; Stuchly, M.A.; Gandhi, O.P.

1993-01-01

Possible health effects of human exposure to 60 Hz magnetic fields are a subject of increasing concern. An understanding of the coupling of electromagnetic fields to human body tissues is essential for assessment of their biological effects. A method is presented for the computerized simulation of induced electric currents and fields in bodies of men and rodents from power-line frequency magnetic fields. In the impedance method, the body is represented by a 3 dimensional impedance network. The computational model consists of several tens of thousands of cubic numerical cells and thus represented a realistic shape. The modelling for humans is performed with two models, a heterogeneous model based on cross-section anatomy and a homogeneous one using an average tissue conductivity. A summary of computed results of induced electric currents and fields is presented. It is confirmed that induced currents are lower than endangerous current levels for most environmental exposures. However, the induced current density varies greatly, with the maximum being at least 10 times larger than the average. This difference is likely to be greater when more detailed anatomy and morphology are considered. 15 refs., 2 figs., 1 tab

Long-lasting effects of neck muscle vibration and contraction on self-motion perception of vestibular origin.

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Pettorossi, Vito Enrico; Panichi, Roberto; Botti, Fabio Massimo; Biscarini, Andrea; Filippi, Guido Maria; Schieppati, Marco

2015-10-01

To show that neck proprioceptive input can induce long-term effects on vestibular-dependent self-motion perception. Motion perception was assessed by measuring the subject's error in tracking in the dark the remembered position of a fixed target during whole-body yaw asymmetric rotation of a supporting platform, consisting in a fast rightward half-cycle and a slow leftward half-cycle returning the subject to the initial position. Neck muscles were relaxed or voluntarily contracted, and/or vibrated. Whole-body rotation was administered during or at various intervals after the vibration train. The tracking position error (TPE) at the end of the platform rotation was measured during and after the muscle conditioning maneuvers. Neck input produced immediate and sustained changes in the vestibular perceptual response to whole-body rotation. Vibration of the left sterno-cleido-mastoideus (SCM) or right splenius capitis (SC) or isometric neck muscle effort to rotate the head to the right enhanced the TPE by decreasing the perception of the slow rotation. The reverse effect was observed by activating the contralateral muscle. The effects persisted after the end of SCM conditioning, and slowly vanished within several hours, as tested by late asymmetric rotations. The aftereffect increased in amplitude and persistence by extending the duration of the vibration train (from 1 to 10min), augmenting the vibration frequency (from 5 to 100Hz) or contracting the vibrated muscle. Symmetric yaw rotation elicited a negligible TPE, upon which neck muscle vibrations were ineffective. Neck proprioceptive input induces enduring changes in vestibular-dependent self-motion perception, conditional on the vestibular stimulus feature, and on the side and the characteristics of vibration and status of vibrated muscles. This shows that our perception of whole-body yaw-rotation is not only dependent on accurate vestibular information, but is modulated by proprioceptive information related to

Protection of power transformers against geomagnetically induced currents

Directory of Open Access Journals (Sweden)

Gurevich Vladimir

2011-01-01

Full Text Available The article examines the problem of saturation and failure of power transformers under geomagnetically induced currents and currents of the E3 component of high-altitude nuclear explosions. It also describes a special protective relay reacting on DC component in the transformer neutral current.

Perception-Induced Effects of Corporate Social Irresponsibility (CSiR) for Stereotypical and Admired Firms.

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Voliotis, Seraphim; Vlachos, Pavlos A; Epitropaki, Olga

2016-01-01

How do stakeholders react to Corporate Social Irresponsibility (CSiR)? What are the emotional mechanisms and behavioral outcomes following CSiR perception? The psychology of CSR literature has yet to address these important questions and has largely considered CSR and CSiR as the opposite poles of the same continuum. In contrast, we view CSR and CSiR as distinct constructs and theorize about the cognitive (perceptual), emotional, and behavioral effects of CSiR activity on observers (i.e., primary and secondary stakeholders) building on theories of intergroup perception. Specifically, building on the Stereotype Content Model (SCM; Fiske et al., 2002) and the BIAS map (i.e., Behaviors from Intergroup Affect and Stereotypes; Cuddy et al., 2007)-which extends the SCM by predicting behavioral responses-we make predictions on potential stakeholder reactions to CSiR focusing on two practice-relevant cases: (a) a typical for-profit firm that engages in a CSiR activity, (b) an atypical admired firm that engages in CSiR activity.

Induced Current Characteristics Due to Laser Induced Plasma and Its Application to Laser Processing Monitoring

International Nuclear Information System (INIS)

Madjid, Syahrun Nur; Idris, Nasrullah; Kurniawan, Koo Hendrik; Kagawa, Kiichiro

2011-01-01

In laser processing, suitable conditions for laser and gas play important role in ensuring a high quality of processing. To determine suitable conditions, we employed the electromagnetic phenomena associated with laser plasma generation. An electrode circuit was utilised to detect induced current due to the fast electrons propelled from the material during laser material processing. The characteristics of induced current were examined by changing parameters such as supplied voltage, laser pulse energy, number of laser shots, and type of ambient gas. These characteristics were compared with the optical emission characteristics. It was shown that the induced current technique proposed in this study is much more sensitive than the optical method in monitoring laser processing, that is to determine the precise focusing condition, and to accurately determine the moment of completion of laser beam penetration. In this study it was also shown that the induced current technique induced by CW CO 2 laser can be applied in industrial material processing for monitoring the penetration completion in a stainless steel plate drilling process.

Evidence for a New Magnetoelectric Effect of Current-Induced Magnetization in a Toroidal Magnetic Ordered State of UNi$_4$B

OpenAIRE

Saito, Hiraku; Uenishi, Kenta; Miura, Naoyuki; Tabata, Chihiro; Hidaka, Hiroyuki; Yanagisawa, Tatsuya; Amitsuka, Hiroshi

2018-01-01

Magnetization measurements under direct electric currents were performed for toroidal magnetic ordered state of UNi$_4$B to test a recent theoretical prediction of current-induced magnetization in a metallic system lacking local inversion symmetry.We found that each of the electric currents parallel to [$2\\bar{1}\\bar{1}0$] and [$0001$] in the hexagonal 4-index notation induces uniform magnetization in the direction of [$01\\bar{1}0$].The observed behavior of the induced magnetization is essent...

The effect of chemically induced colitis, psychological stress and their combination on visceral pain in female Wistar rats.

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Deiteren, Annemie; Vermeulen, Wim; Moreels, Tom G; Pelckmans, Paul A; De Man, Joris G; De Winter, Benedicte Y

2014-09-01

Visceral sensitivity is of pathophysiological importance in abdominal pain disorders and can be modulated by inflammation and stress. However, it is unclear whether inflammation and stress alter visceral perception independently of each other or in conjunction through neuroendocrine interactions. Therefore, we compared the short- and long-term effects of experimental colitis and water avoidance stress (WAS), alone or in combination, on visceral sensitivity in female Wistar rats. Colitis was induced by trinitrobenzene sulfonic acid (TNBS) and colonoscopically confirmed. During WAS, rats were placed on a platform surrounded by water for 1 h. Visceral sensitivity was assessed by quantifying the visceromotor responses (VMRs) to colorectal distension. Activation of the hypothalamic-pituitary-adrenal axis was determined by measuring serum corticosterone in a separate protocol. TNBS instillation resulted in overt colitis, associated with significant visceral hypersensitivity during the acute inflammatory phase (3 days post-TNBS; n = 8/group); after colitis had subsided (28 days post-TNBS), hypersensitivity was resolved (n = 4-8/group). Single WAS was associated with increased VMRs of a magnitude comparable to acute TNBS-induced hypersensitivity (n = 8/group). However, after repetitive WAS no significant hypersensitivity was present (n = 8/group). No additive effect of colitis and stress was seen on visceral pain perception (n = 6-8/group). Corticosterone levels were only increased in acute TNBS-colitis, acute WAS and their combination. To conclude, both colitis and stress successfully induced short-term visceral hypersensitivity and activated the hypothalamic-pituitary-adrenal axis, but long-term effects were absent. In addition, our current findings do not support an additive effect of colitis and stress on visceral sensitivity in female Wistar rats.

Strain and thermally induced magnetic dynamics and spin current in magnetic insulators subject to transient optical grating

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Wang, Xi-Guang; Chotorlishvili, Levan; Berakdar, Jamal

2017-07-01

We analyze the magnetic dynamics and particularlythe spin current in an open-circuit ferromagnetic insulator irradiated by two intense, phase-locked laser pulses. The interference of the laser beams generates a transient optical grating and a transient spatio-temporal temperature distribution. Both effects lead to elastic and heat waves at the surface and into the bulk of the sample. The strain induced spin current as well as the thermally induced magnonic spin current are evaluated numerically on the basis of micromagnetic simulations using solutions of the heat equation. We observe that the thermo-elastically induced magnonic spin current propagates on a distance larger than the characteristic size of thermal profile, an effect useful for applications in remote detection of spin caloritronics phenomena. Our findings point out that exploiting strain adds a new twist to heat-assisted magnetic switching and spin-current generation for spintronic applications.

Current-Induced Transistor Sensorics with Electrogenic Cells

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Peter Fromherz

2016-04-01

Full Text Available The concepts of transistor recording of electroactive cells are considered, when the response is determined by a current-induced voltage in the electrolyte due to cellular activity. The relationship to traditional transistor recording, with an interface-induced response due to interactions with the open gate oxide, is addressed. For the geometry of a cell-substrate junction, the theory of a planar core-coat conductor is described with a one-compartment approximation. The fast electrical relaxation of the junction and the slow change of ion concentrations are pointed out. On that basis, various recording situations are considered and documented by experiments. For voltage-gated ion channels under voltage clamp, the effects of a changing extracellular ion concentration and the enhancement/depletion of ion conductances in the adherent membrane are addressed. Inhomogeneous ion conductances are crucial for transistor recording of neuronal action potentials. For a propagating action potential, the effects of an axon-substrate junction and the surrounding volume conductor are distinguished. Finally, a receptor-transistor-sensor is described, where the inhomogeneity of a ligand–activated ion conductance is achieved by diffusion of the agonist and inactivation of the conductance. Problems with regard to a development of reliable biosensors are mentioned.

Muscle spindle thixotropy affects force perception through afferent-induced facilitation of the motor pathways as revealed by the Kohnstamm effect.

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Monjo, Florian; Forestier, Nicolas

2018-04-01

This study was designed to explore the effects of intrafusal thixotropy, a property affecting muscle spindle sensitivity, on the sense of force. For this purpose, psychophysical measurements of force perception were performed using an isometric force matching paradigm of elbow flexors consisting of matching different force magnitudes (5, 10 and 20% of subjects' maximal voluntary force). We investigated participants' capacity to match these forces after their indicator arm had undergone voluntary isometric conditioning contractions known to alter spindle thixotropy, i.e., contractions performed at long ('hold long') or short muscle lengths ('hold short'). In parallel, their reference arm was conditioned at the intermediate muscle length ('hold-test') at which the matchings were performed. The thixotropy hypothesis predicts that estimation errors should only be observed at low force levels (up to 10% of the maximal voluntary force) with overestimation of the forces produced following 'hold short' conditioning and underestimation following 'hold long' conditioning. We found the complete opposite, especially following 'hold-short' conditioning where subjects underestimated the force they generated with similar relative error magnitudes across force levels. In a second experiment, we tested the hypothesis that estimation errors depended on the degree of afferent-induced facilitation using the Kohnstamm phenomenon as a probe of motor pathway excitability. Because the stronger post-effects were observed following 'hold-short' conditioning, it appears that the conditioning-induced excitation of spindle afferents leads to force misjudgments by introducing a decoupling between the central effort and the cortical motor outputs.

The effect of occlusion therapy on motion perception deficits in amblyopia.

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Giaschi, Deborah; Chapman, Christine; Meier, Kimberly; Narasimhan, Sathyasri; Regan, David

2015-09-01

There is growing evidence for deficits in motion perception in amblyopia, but these are rarely assessed clinically. In this prospective study we examined the effect of occlusion therapy on motion-defined form perception and multiple-object tracking. Participants included children (3-10years old) with unilateral anisometropic and/or strabismic amblyopia who were currently undergoing occlusion therapy and age-matched control children with normal vision. At the start of the study, deficits in motion-defined form perception were present in at least one eye in 69% of the children with amblyopia. These deficits were still present at the end of the study in 55% of the amblyopia group. For multiple-object tracking, deficits were present initially in 64% and finally in 55% of the children with amblyopia, even after completion of occlusion therapy. Many of these deficits persisted in spite of an improvement in amblyopic eye visual acuity in response to occlusion therapy. The prevalence of motion perception deficits in amblyopia as well as their resistance to occlusion therapy, support the need for new approaches to amblyopia treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamical nuclear spin polarization induced by electronic current through double quantum dots

International Nuclear Information System (INIS)

Lopez-Monis, Carlos; Platero, Gloria; Inarrea, Jesus

2011-01-01

We analyse electron-spin relaxation in electronic transport through coherently coupled double quantum dots (DQDs) in the spin blockade regime. In particular, we focus on hyperfine (HF) interaction as the spin-relaxation mechanism. We pay special attention to the effect of the dynamical nuclear spin polarization induced by the electronic current on the nuclear environment. We discuss the behaviour of the electronic current and the induced nuclear spin polarization versus an external magnetic field for different HF coupling intensities and interdot tunnelling strengths. We take into account, for each magnetic field, all HF-mediated spin-relaxation processes coming from different opposite spin level approaches. We find that the current as a function of the external magnetic field shows a peak or a dip and that the transition from a current dip to a current peak behaviour is obtained by decreasing the HF coupling or by increasing the interdot tunnelling strength. We give a physical picture in terms of the interplay between the electrons tunnelling out of the DQD and the spin-flip processes due to the nuclear environment.

Electric currents induced by twisted light in Quantum Rings.

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Quinteiro, G F; Berakdar, J

2009-10-26

We theoretically investigate the generation of electric currents in quantum rings resulting from the optical excitation with twisted light. Our model describes the kinetics of electrons in a two-band model of a semiconductor-based mesoscopic quantum ring coupled to light having orbital angular momentum (twisted light). We find the analytical solution, which exhibits a "circular" photon-drag effect and an induced magnetization, suggesting that this system is the circular analog of that of a bulk semiconductor excited by plane waves. For realistic values of the electric field and material parameters, the computed electric current can be as large as microA; from an applied perspective, this opens new possibilities to the optical control of the magnetization in semiconductors.

Audio effects on haptics perception during drilling simulation

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Yair Valbuena

2017-06-01

Full Text Available Virtual reality has provided immersion and interactions through computer generated environments attempting to reproduce real life experiences through sensorial stimuli. Realism can be achieved through multimodal interactions which can enhance the user’s presence within the computer generated world. The most notorious advances in virtual reality can be seen in computer graphics visuals, where photorealism is the norm thriving to overcome the uncanny valley. Other advances have followed related to sound, haptics, and in a lesser manner smell and taste feedback. Currently, virtual reality systems (multimodal immersion and interactions through visual-haptic-sound are being massively used in entertainment (e.g., cinema, video games, art, and in non-entertainment scenarios (e.g., social inclusion, educational, training, therapy, and tourism. Moreover, the cost reduction of virtual reality technologies has resulted in the availability at a consumer-level of various haptic, headsets, and motion tracking devices. Current consumer-level devices offer low-fidelity experiences due to the properties of the sensors, displays, and other electro-mechanical devices, that may not be suitable for high-precision or realistic experiences requiring dexterity. However, research has been conducted on how toovercome or compensate the lack of high fidelity to provide an engaging user experience using storytelling, multimodal interactions and gaming elements. Our work focuses on analyzing the possible effects of auditory perception on haptic feedback within a drilling scenario. Drilling involves multimodal interactions and it is a task with multiple applications in medicine, crafting, and construction. We compare two drilling scenarios were two groups of participants had to drill through wood while listening to contextual and non-contextual audios. We gathered their perception using a survey after the task completion. From the results, we believe that sound does

Action-based effects on music perception.

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Maes, Pieter-Jan; Leman, Marc; Palmer, Caroline; Wanderley, Marcelo M

2014-01-03

The classical, disembodied approach to music cognition conceptualizes action and perception as separate, peripheral processes. In contrast, embodied accounts of music cognition emphasize the central role of the close coupling of action and perception. It is a commonly established fact that perception spurs action tendencies. We present a theoretical framework that captures the ways in which the human motor system and its actions can reciprocally influence the perception of music. The cornerstone of this framework is the common coding theory, postulating a representational overlap in the brain between the planning, the execution, and the perception of movement. The integration of action and perception in so-called internal models is explained as a result of associative learning processes. Characteristic of internal models is that they allow intended or perceived sensory states to be transferred into corresponding motor commands (inverse modeling), and vice versa, to predict the sensory outcomes of planned actions (forward modeling). Embodied accounts typically refer to inverse modeling to explain action effects on music perception (Leman, 2007). We extend this account by pinpointing forward modeling as an alternative mechanism by which action can modulate perception. We provide an extensive overview of recent empirical evidence in support of this idea. Additionally, we demonstrate that motor dysfunctions can cause perceptual disabilities, supporting the main idea of the paper that the human motor system plays a functional role in auditory perception. The finding that music perception is shaped by the human motor system and its actions suggests that the musical mind is highly embodied. However, we advocate for a more radical approach to embodied (music) cognition in the sense that it needs to be considered as a dynamical process, in which aspects of action, perception, introspection, and social interaction are of crucial importance.

Action-based effects on music perception

Science.gov (United States)

Maes, Pieter-Jan; Leman, Marc; Palmer, Caroline; Wanderley, Marcelo M.

2013-01-01

The classical, disembodied approach to music cognition conceptualizes action and perception as separate, peripheral processes. In contrast, embodied accounts of music cognition emphasize the central role of the close coupling of action and perception. It is a commonly established fact that perception spurs action tendencies. We present a theoretical framework that captures the ways in which the human motor system and its actions can reciprocally influence the perception of music. The cornerstone of this framework is the common coding theory, postulating a representational overlap in the brain between the planning, the execution, and the perception of movement. The integration of action and perception in so-called internal models is explained as a result of associative learning processes. Characteristic of internal models is that they allow intended or perceived sensory states to be transferred into corresponding motor commands (inverse modeling), and vice versa, to predict the sensory outcomes of planned actions (forward modeling). Embodied accounts typically refer to inverse modeling to explain action effects on music perception (Leman, 2007). We extend this account by pinpointing forward modeling as an alternative mechanism by which action can modulate perception. We provide an extensive overview of recent empirical evidence in support of this idea. Additionally, we demonstrate that motor dysfunctions can cause perceptual disabilities, supporting the main idea of the paper that the human motor system plays a functional role in auditory perception. The finding that music perception is shaped by the human motor system and its actions suggests that the musical mind is highly embodied. However, we advocate for a more radical approach to embodied (music) cognition in the sense that it needs to be considered as a dynamical process, in which aspects of action, perception, introspection, and social interaction are of crucial importance. PMID:24454299

Action-based effects on music perception

Directory of Open Access Journals (Sweden)

Pieter-Jan eMaes

2014-01-01

Full Text Available The classical, disembodied approach to music cognition conceptualizes action and perception as separate, peripheral phenomena. In contrast, embodied accounts to music cognition emphasize the central role of the close coupling of action and perception. It is a commonly established fact that perception spurs action tendencies. We present a theoretical framework capturing the ways that the human motor system, and the actions it produces, can reciprocally influence the perception of music. The cornerstone of this framework is the common coding theory postulating a representational overlap in the brain between the planning, the execution, and the perception of movement. The integration of action and perception in so-called internal models is explained as a result of associative learning processes. Characteristic of internal models is that they allow intended or perceived sensory states to be transferred into corresponding motor commands (inverse modelling, and vice versa, to predict the sensory outcomes of planned actions (forward modelling. Embodied accounts typically adhere to inverse modelling to explain action effects on music perception (Leman, 2007. We extent this account by pinpointing forward modelling as an alternative mechanism by which action can modulate perception. We provide an extensive overview of recent empirical evidence in support of this idea. Additionally, we demonstrate that motor dysfunctions can cause perceptual disabilities, supporting the main idea of the paper that the human motor system plays a functional role in auditory perception. The finding that music perception is shaped by the human motor system, and the action it produces, suggests that the musical mind is highly embodied. However, we advocate for a more radical approach to embodied (music cognition in the sense that it needs to be considered as a dynamic process, in which aspects of action, perception, introspection, and social interaction are of crucial

Observation of transverse spin Nernst magnetoresistance induced by thermal spin current in ferromagnet/non-magnet bilayers.

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Kim, Dong-Jun; Jeon, Chul-Yeon; Choi, Jong-Guk; Lee, Jae Wook; Surabhi, Srivathsava; Jeong, Jong-Ryul; Lee, Kyung-Jin; Park, Byong-Guk

2017-11-09

Electric generation of spin current via spin Hall effect is of great interest as it allows an efficient manipulation of magnetization in spintronic devices. Theoretically, pure spin current can be also created by a temperature gradient, which is known as spin Nernst effect. Here, we report spin Nernst effect-induced transverse magnetoresistance in ferromagnet/non-magnetic heavy metal bilayers. We observe that the magnitude of transverse magnetoresistance in the bilayers is significantly modified by heavy metal and its thickness. This strong dependence of transverse magnetoresistance on heavy metal evidences the generation of thermally induced pure spin current in heavy metal. Our analysis shows that spin Nernst angles of W and Pt have the opposite sign to their spin Hall angles. Moreover, our estimate implies that the magnitude of spin Nernst angle would be comparable to that of spin Hall angle, suggesting an efficient generation of spin current by the spin Nernst effect.

Characteristics of Effective EFL Instructors: Language Teachers’ Perceptions Versus Learners’ Perceptions

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Negar Hajizadeh

2014-01-01

Full Text Available Improving the field of foreign language teaching without improving the qualities of the teachers seems impossible. This attempt, at first hand, requires recognizing the qualities of effective EFL teachers. The aim of this study was to find what foreign language instructors perceive to be the most important characteristics of a successful EFL teacher. In addition, the teachers’ perception was compared to that of learners’ to see whether there were discrepancies between the two groups’ perceptions regarding the preferable characteristics of an effective English language instructors or not. A 58-item questionnaire was administered to teachers at a prominent language institute in Iran. This questionnaire was divided into eight sections and addressed issues relating to teachers’ personal qualities, command in English, teaching methods and evaluation methods they used within the class, mastery over teaching, teacher-student relation, class management and finally language skills management. Teachers were asked to specify the importance of each item in the questionnaire using terms like not important at all, somehow important, important and finally very important. Basic statistics were used to convert the qualitative results into quantitative ones for easier comparison. Interestingly however, the study revealed that the students’ perceptions and teachers’ perceptions do not differ in major ways although there are slight discrepancies.

The Effects of Acute Stress-Induced Sleep Disturbance on Acoustic Trauma-Induced Tinnitus in Rats

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Yiwen Zheng

2014-01-01

Full Text Available Chronic tinnitus is a debilitating condition and often accompanied by anxiety, depression, and sleep disturbance. It has been suggested that sleep disturbance, such as insomnia, may be a risk factor/predictor for tinnitus-related distress and the two conditions may share common neurobiological mechanisms. This study investigated whether acute stress-induced sleep disturbance could increase the susceptibility to acoustic trauma-induced tinnitus in rats. The animals were exposed to unilateral acoustic trauma 24 h before sleep disturbance being induced using the cage exchange method. Tinnitus perception was assessed behaviourally using a conditioned lick suppression paradigm 3 weeks after the acoustic trauma. Changes in the orexin system in the hypothalamus, which plays an important role in maintaining long-lasting arousal, were also examined using immunohistochemistry. Cage exchange resulted in a significant reduction in the number of sleep episodes and acoustic trauma-induced tinnitus with acoustic features similar to a 32 kHz tone at 100 dB. However, sleep disturbance did not exacerbate the perception of tinnitus in rats. Neither tinnitus alone nor tinnitus plus sleep disturbance altered the number of orexin-expressing neurons. The results suggest that acute sleep disturbance does not cause long-term changes in the number of orexin neurons and does not change the perception of tinnitus induced by acoustic trauma in rats.

Obesity prevention programs and policies: practitioner and policy-maker perceptions of feasibility and effectiveness.

Science.gov (United States)

Cleland, Verity; McNeilly, Briohny; Crawford, David; Ball, Kylie

2013-09-01

The aims of this study were to map obesity prevention activity being implemented by government, non-government, and community-based organizations; to determine practitioner and policy-maker perceptions of the feasibility and effectiveness of a range of evidence-based obesity prevention strategies; and to determine practitioner and policy-maker perceptions of preferred settings for obesity prevention strategies. This study involved a cross-sectional survey of 304 public health practitioners and policy-makers from government, non-government, and community organizations across Victoria, Australia. Participants reported their organizations' current obesity prevention programs and policies, their own perceptions of the feasibility and effectiveness of strategies to prevent obesity and their preferred settings for obesity prevention. Thirty-nine percent had an obesity prevention policy, and 92% were implementing obesity prevention programs. The most common programs focused on education, skill-building, and increasing access to healthy eating/physical activity opportunities. School curriculum-based initiatives, social support for physical activity, and family-based programs were considered the most effective strategies, whereas curriculum-based initiatives, active after-school programs, and providing access to and information about physical activity facilities were deemed the most feasible strategies. Schools were generally perceived as the most preferred setting for obesity prevention. Many organizations had obesity prevention programs, but far fewer had obesity prevention policies. Current strategies and those considered feasible and effective are often mismatched with the empirical literature. Systems to ensure better alignment between researchers, practitioners, and policy-makers, and identifying effective methods of translating empirical evidence into practice and policy are required. Copyright © 2012 The Obesity Society.

Spin current induced by a charged tip in a quantum point contact

Energy Technology Data Exchange (ETDEWEB)

Shchamkhalova, B.S., E-mail: s.bagun@gmail.com

2017-03-15

We show that the charged tip of the probe microscope, which is widely used in studying the electron transport in low-dimensional systems, induces a spin current. The effect is caused by the spin–orbit interaction arising due to an electric field produced by the charged tip. The tip acts as a spin-flip scatterer giving rise to the spin polarization of the net current and the occurrence of a spin density in the system.

Effects of Patient-Provider Race Concordance and Smoking Status on Lung Cancer Risk Perception Accuracy among African Americans

Science.gov (United States)

Persky, Susan; Kaphingst, Kimberly A.; Allen, Vincent C.; Senay, Ibrahim

2013-01-01

Background Communication of lung cancer risk information between providers and African-American patients occurs in a context marked by race-based health disparities. Purpose A controlled experiment assessed whether perceived physician race influenced African-American patients’ (n=127) risk perception accuracy following the provision of objective lung cancer risk information. Methods Participants interacted with a virtual reality-based, simulated physician who provided personalized cancer risk information. Results Participants who interacted with a racially discordant virtual doctor were less accurate in their risk perceptions at post-test than those who interacted with a concordant virtual doctor, F(1,94)=4.02, p=.048. This effect was amplified among current smokers. Effects were not mediated by trust in the provider, engagement with the health care system, or attention during the encounter. Conclusions The current study demonstrates that African-American patients’ perceptions of a doctor’s race are sufficient to independently impact their processing of lung cancer risk information. PMID:23389688

Effects of patient-provider race concordance and smoking status on lung cancer risk perception accuracy among African-Americans.

Science.gov (United States)

Persky, Susan; Kaphingst, Kimberly A; Allen, Vincent C; Senay, Ibrahim

2013-06-01

Communication of lung cancer risk information between providers and African-American patients occurs in a context marked by race-based health disparities. A controlled experiment assessed whether perceived physician race influenced African-American patients' (n = 127) risk perception accuracy following the provision of objective lung cancer risk information. Participants interacted with a virtual reality-based, simulated physician who provided personalized cancer risk information. Participants who interacted with a racially discordant virtual doctor were less accurate in their risk perceptions at post-test than those who interacted with a concordant virtual doctor, F(1,94) = 4.02, p = .048. This effect was amplified among current smokers. Effects were not mediated by trust in the provider, engagement with the health care system, or attention during the encounter. The current study demonstrates that African-American patients' perceptions of a doctor's race are sufficient to independently impact their processing of lung cancer risk information.

Wave-induced current considering wave-tide interaction in Haeundae

Science.gov (United States)

Lim, Hak Soo

2017-04-01

The Haeundae, located at the south eastern end of the Korean Peninsula, is a famous beach, which has an approximately 1.6 km long and 70 m wide coastline. The beach has been repeatedly eroded by the swell waves caused by typhoons in summer and high waves originating in the East Sea in winter. The Korean government conducted beach restoration projects including beach nourishment (620,000 m3) and construction of two submerged breakwaters near both ends of the beach. To prevent the beach erosion and to support the beach restoration project, the Korean government initiated a R&D project, the development of coastal erosion control technology since 2013. As a part of the project, we have been measuring waves and currents at a water depth of 22 m, 1.8 km away from the beach using an acoustic wave and current meter (AWAC) continuously for more than three years; we have also measured waves and currents intensively near the surf-zone in summer and winter. In this study, a numerical simulation using a wave and current coupled model (ROMS-SWAN) was conducted for determining the wave-induced current considering seasonal swell waves (Hs : 2.5 m, Tp: 12 s) and for better understanding of the coastal process near the surf-zone in Haeundae. By comparing the measured and simulated results, we found that cross-shore current during summer is mainly caused by the eddy produced by the wave-induced current near the beach, which in turn, is generated by the strong waves coming from the SSW and S directions. During other seasons, longshore wave-induced current is produced by the swell waves coming from the E and ESE directions. The longshore current heading west toward Dong-Back Island, west end of the beach, during all the seasons and eddy current toward Mipo-Port, east end of the beach, in summer which is well matched with the observed residual current. The wave-induced current with long-term measurement data is incorporated in simulation of sediment transport modeling for developing

Effects of e-Cigarette Advertisements on Adolescents' Perceptions of Cigarettes.

Science.gov (United States)

Kim, Minji; Popova, Lucy; Halpern-Felsher, Bonnie; Ling, Pamela M

2017-12-13

This study examined the effect of exposure to "cigalike" (products resembling cigarettes) e-cigarette advertisements on adolescents' perceptions of cigarettes. A nationally representative sample of 802 adolescents (13-17 years old) was randomly assigned to watch three e-cigarette or three control advertisements. Never-smokers who saw the e-cigarette advertisements (n = 352) reported significantly lower perceived risks of smoking than those in the control condition (n = 320). Ever-smokers (n = 130) did not show significant differences across the conditions. In subgroup analyses, current smokers (reported smoking in the past 30 days, n = 31) in the e-cigarette condition reported significantly lower perceived benefits of smoking than those in the control condition. E-cigarette advertisements can affect adolescents' perceptions of cigarettes. Many advertisements, especially the ones promoting "cigalikes," depict e-cigarettes as being similar to cigarettes (e.g., look, flavor) but also as a solution for cigarettes' shortcomings (e.g., bad smell). While the advertisements include messages about problems posed by cigarettes, proposing e-cigarettes as a solution may decrease the perceived risks of smoking among never-smokers. It may also not be clear to adolescents whether advertisements are for cigarettes or e-cigarettes. Regulating e-cigarette advertisements to minimize adolescents' exposure may prevent potential harmful effects on never-smokers' perception of smoking.

High School Rugby Players' Perception of Coaching Effectiveness

Science.gov (United States)

Broodryk, Retief; van den Berg, Pieter Hendrick

2011-01-01

The aims of this study were firstly to determine the players' perceptions of their respective coaches' coaching effectiveness and secondly, determine the difference between big and small schools of the players' perceptions of their respective coaches' coaching effectiveness. Four hundred and seventy six players from 22 schools were asked to fill…

Perception of Arabidopsis AtPep peptides, but not bacterial elicitors, accelerates starvation-induced senescence

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Kay eGully

2015-01-01

Full Text Available Members of the AtPep group of Arabidopsis endogenous peptides have frequently been reported to induce pattern-triggered immunity and to increase resistance to diverse pathogens by amplifying the innate immune response. Here, we made the surprising observation that dark-induced leaf senescence was accelerated by the presence of Peps. Adult leaves as well as leaf discs of Col-0 wild type plants showed a Pep-triggered early onset of chlorophyll breakdown and leaf yellowing whereas pepr1 pepr2 double mutant plants were insensitive. In addition, this response was dependent on ethylene signaling and inhibited by the addition of cytokinins. Notably, addition of the bacterial elicitors flg22 or elf18, both potent inducers of pattern-triggered immunity, did not provoke an early onset of leaf senescence.Continuous darkness leads to energy deprivation and starvation and therewith promotes leaf senescence. We found that continuous darkness also strongly induced PROPEP3 transcription. Moreover, Pep-perception led to a rapid induction of PAO, APG7 and APG8a, genes indispensable for chlorophyll degradation as well as autophagy, respectively, and all three hallmarks of starvation and senescence. Notably, addition of sucrose as a source of energy inhibited the Pep-triggered early onset of senescence. In conclusion, we report that Pep-perception accelerates dark/starvation-induced senescence via an early induction of chlorophyll degradation and autophagy. This represents a novel and unique characteristic of PEPR signaling, unrelated to pattern-triggered immunity.

Adolescents’ Perceptions Regarding Effective Tobacco Use Prevention Strategies for their Younger Counterparts: A Qualitative Study in Malaysia

Science.gov (United States)

Mohd Zin, Faridah; Hillaluddin, Azlin Hilma; Mustaffa, Jamaludin

2016-12-01

Purpose:The present qualitative study explored adolescents’ perceptions regarding effective strategies to prevent adolescents from using tobacco products (TP). Apart from the commercial TPs, there has been emerging use of alternatives such as vapes, e-cigarettes and shisha. This unfortunate phenomenon continues despite the currently available preventive strategies. Thus, understanding of the perceptions of the current generation would be valuable to provide new insights. Methods: Purposive sampling was utilized to recruit 40 adolescents between the age of 15 and 16 years old attending public daily secondary schools. Eight focus group discussions were conducted among the TP users, ex-users and non-users. Data were analyzed using a thematic content analysis procedure with NVivo. Results: Among barriers with the currently available strategies were having teachers who smoke tobacco, addiction to nicotine and self-perceptions of being healthy. The content of any program should include knowledge on negative outcomes of using tobacco products and awareness of the legislation together with ways to overcome peer and family influence including improving self-efficacy and refusal skills. Strategies were suggested to be delivered using information technology which provides interactive learning and visual effects. Conclusions: Adolescents agreed that the content and delivery of tobacco use prevention strategies need to be revised to suit the current generation to ensure sustainability. Creative Commons Attribution License

Effects of noise and reverberation on speech perception and listening comprehension of children and adults in a classroom-like setting.

Science.gov (United States)

Klatte, Maria; Lachmann, Thomas; Meis, Markus

2010-01-01

The effects of classroom noise and background speech on speech perception, measured by word-to-picture matching, and listening comprehension, measured by execution of oral instructions, were assessed in first- and third-grade children and adults in a classroom-like setting. For speech perception, in addition to noise, reverberation time (RT) was varied by conducting the experiment in two virtual classrooms with mean RT = 0.47 versus RT = 1.1 s. Children were more impaired than adults by background sounds in both speech perception and listening comprehension. Classroom noise evoked a reliable disruption in children's speech perception even under conditions of short reverberation. RT had no effect on speech perception in silence, but evoked a severe increase in the impairments due to background sounds in all age groups. For listening comprehension, impairments due to background sounds were found in the children, stronger for first- than for third-graders, whereas adults were unaffected. Compared to classroom noise, background speech had a smaller effect on speech perception, but a stronger effect on listening comprehension, remaining significant when speech perception was controlled. This indicates that background speech affects higher-order cognitive processes involved in children's comprehension. Children's ratings of the sound-induced disturbance were low overall and uncorrelated to the actual disruption, indicating that the children did not consciously realize the detrimental effects. The present results confirm earlier findings on the substantial impact of noise and reverberation on children's speech perception, and extend these to classroom-like environmental settings and listening demands closely resembling those faced by children at school.

Current-induced energy barrier suppression for electromigration from first principles

KAUST Repository

Zhang, Ruoxing

2011-08-01

We present an efficient method for evaluating current-induced forces in nanoscale junctions, which naturally integrates into the nonequilibrium Green\\'s function formalism implemented within density functional theory. This allows us to perform dynamic atomic relaxation in the presence of an electric current while evaluating the current-voltage characteristics. The central idea consists of expressing the system energy density matrix in terms of Green\\'s functions. To validate our implementation, we perform a series of benchmark calculations, both at zero and at finite bias. First we evaluate the current-induced forces acting over an Al nanowire and compare them with previously published results for fixed geometries. Then we perform structural relaxation of the same wires under bias and determine the critical voltage at which they break. We find that although a perfectly straight wire does not break at any of the voltages considered, a zigzag wire is more fragile and snaps at 1.4 V, with the Al atoms moving against the electron flow. The critical current density for the rupture is estimated to be 9.6 × 1010 A/cm2, in good agreement with the experimentally measured value of 5 × 1010 A/cm2. Finally, we demonstrate the capability of our scheme to tackle the electromigration problem by studying the current-induced motion of a single Si atom covalently attached to the sidewall of a (4,4) armchair single-walled carbon nanotube. Our calculations indicate that if Si is attached along the current path, then current-induced forces can induce migration. In contrast, if the bonding site is away from the current path, then the adatom remains stable regardless of the voltage. An analysis based on decomposing the total force into a wind and an electrostatic component, as well as on a detailed evaluation of the bond currents, shows that this remarkable electromigration phenomenon is due solely to the position-dependent wind force. © 2011 American Physical Society.

Visceral hyperalgesia induced by forebrain-specific suppression of native Kv7/KCNQ/M-current in mice

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Bian Xiling

2011-10-01

Full Text Available Abstract Background Dysfunction of brain-gut interaction is thought to underlie visceral hypersensitivity which causes unexplained abdominal pain syndromes. However, the mechanism by which alteration of brain function in the brain-gut axis influences the perception of visceral pain remains largely elusive. In this study we investigated whether altered brain activity can generate visceral hyperalgesia. Results Using a forebrain specific αCaMKII promoter, we established a line of transgenic (Tg mice expressing a dominant-negative pore mutant of the Kv7.2/KCNQ2 channel which suppresses native KCNQ/M-current and enhances forebrain neuronal excitability. Brain slice recording of hippocampal pyramidal neurons from these Tg mice confirmed the presence of hyperexcitable properties with increased firing. Behavioral evaluation of Tg mice exhibited increased sensitivity to visceral pain induced by intraperitoneal (i.p. injection of either acetic acid or magnesium sulfate, and intracolon capsaicin stimulation, but not cutaneous sensation for thermal or inflammatory pain. Immunohistological staining showed increased c-Fos expression in the somatosensory SII cortex and insular cortex of Tg mice that were injected intraperitoneally with acetic acid. To mimic the effect of cortical hyperexcitability on visceral hyperalgesia, we injected KCNQ/M channel blocker XE991 into the lateral ventricle of wild type (WT mice. Intracerebroventricular injection of XE991 resulted in increased writhes of WT mice induced by acetic acid, and this effect was reversed by co-injection of the channel opener retigabine. Conclusions Our findings provide evidence that forebrain hyperexcitability confers visceral hyperalgesia, and suppression of central hyperexcitability by activation of KCNQ/M-channel function may provide a therapeutic potential for treatment of abdominal pain syndromes.

Effects of prosody on spoken Thai word perception in pre-attentive brain processing: a pilot study

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Kittipun Arunphalungsanti

2016-12-01

Full Text Available This study aimed to investigate the effect of the unfamiliar stressed prosody on spoken Thai word perception in the pre-attentive processing of the brain evaluated by the N2a and brain wave oscillatory activity. EEG recording was obtained from eleven participants, who were instructed to ignore the sound stimuli while watching silent movies. Results showed that prosody of unfamiliar stress word perception elicited N2a component and the quantitative EEG analysis found that theta and delta wave powers were principally generated in the frontal area. It was possible that the unfamiliar prosody with different frequencies, duration and intensity of the sound of Thai words induced highly selective attention and retrieval of information from the episodic memory of the pre-attentive stage of speech perception. This brain electrical activity evidence could be used for further study in the development of valuable clinical tests to evaluate the frontal lobe function in speech perception.

Current study on ionizing radiation-induced mitochondial DNA damage and mutations

International Nuclear Information System (INIS)

Zhou Xin; Wang Zhenhua; Zhang Hong

2012-01-01

Current advance in ionizing radiation-induced mitochondrial DNA damage and mutations is reviewed, in addition with the essential differences between mtDNA and nDNA damage and mutations. To extent the knowledge about radiation induced mitochondrial alterations, the researchers in Institute of Modern Physics, Chinese Academy of Sciences developed some technics such as real-time PCR, long-PCR for accurate quantification of radiation induced damage and mutations, and in-depth investigation about the functional changes of mitochondria based on mtDNA damage and mutations were also carried out. In conclusion, the important role of mitochondrial study in radiation biology is underlined, and further study on mitochondrial study associated with late effect and metabolism changes in radiation biology is pointed out. (authors)

Perception through a Perspective-Taking Lens: Differential Effects on Judgment and Behavior

OpenAIRE

Ku , Gillian; Wang , Cynthia S.; Galinsky , Adam D.

2010-01-01

International audience; In contrast to the view that social perception has symmetric effects on judgments and behavior, the current research explored whether perspective-taking leads stereotypes to differentially affect judgments and behavior. Across three studies, perspective-takers consistently used stereotypes more in their own behavior while simultaneously using them less in their judgments of others. After writing about an African American, perspective-taking tendencies were positively c...

The association of motor imagery and kinesthetic illusion prolongs the effect of transcranial direct current stimulation on corticospinal tract excitability.

Science.gov (United States)

Kaneko, Fuminari; Shibata, Eriko; Hayami, Tatsuya; Nagahata, Keita; Aoyama, Toshiyuki

2016-04-15

A kinesthetic illusion induced by a visual stimulus (KI) can produce vivid kinesthetic perception. During KI, corticospinal tract excitability increases and results in the activation of cerebral networks. Transcranial direct current stimulation (tDCS) is emerging as an alternative potential therapeutic modality for a variety of neurological and psychiatric conditions, such that identifying factors that enhance the magnitude and duration of tDCS effects is currently a topic of great scientific interest. This study aimed to establish whether the combination of tDCS with KI and sensory-motor imagery (MI) induces larger and longer-lasting effects on the excitability of corticomotor pathways in healthy Japanese subjects. A total of 21 healthy male volunteers participated in this study. Four interventions were investigated in the first experiment: (1) anodal tDCS alone (tDCSa), (2) anodal tDCS with visually evoked kinesthetic illusion (tDCSa + KI), (3) anodal tDCS with motor imagery (tDCSa + MI), and (4) anodal tDCS with kinesthetic illusion and motor imagery (tDCSa + KIMI). In the second experiment, we added a sham tDCS intervention with kinesthetic illusion and motor imagery (sham + KIMI) as a control for the tDCSa + KIMI condition. Direct currents were applied to the right primary motor cortex. Corticospinal excitability was examined using transcranial magnetic stimulation of the area associated with the left first dorsal interosseous. In the first experiment, corticomotor excitability was sustained for at least 30 min following tDCSa + KIMI (p < 0.01). The effect of tDCSa + KIMI on corticomotor excitability was greater and longer-lasting than that achieved in all other conditions. In the second experiment, significant effects were not achieved following sham + KIMI. Our results suggest that tDCSa + KIMI has a greater therapeutic potential than tDCS alone for inducing higher excitability of the corticospinal tract. The observed

The complex duration perception of emotional faces: Effects of face direction

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Katrin Martina Kliegl

2015-03-01

Full Text Available The perceived duration of emotional face stimuli strongly depends on the expressed emotion. But, emotional faces also differ regarding a number of other features like gaze, face direction, or sex. Usually, these features have been controlled by only using pictures of female models with straight gaze and face direction. Doi and Shinohara (2009 reported that an overestimation of angry faces could only be found when the model’s gaze was oriented towards the observer. We aimed at replicating this effect for face direction. Moreover, we explored the effect of face direction on the duration perception sad faces. Controlling for the sex of the face model and the participant, female and male participants rated the duration of neutral, angry and sad face stimuli of both sexes photographed from different perspectives in a bisection task. In line with current findings, we report a significant overestimation of angry compared to neutral face stimuli that was modulated by face direction. Moreover, the perceived duration of sad face stimuli did not differ from that of neutral faces and was not influenced by face direction. Furthermore, we found that faces of the opposite sex appeared to last longer than those of the same sex. This outcome is discussed with regards to stimulus parameters like the induced arousal, social relevance and an evolutionary context.

Forward current enhanced elimination of the radiation induced boron-oxygen complex in silicon n+-p diodes

CERN Document Server

Makarenko, L F; Yakushevich, H S; Moll, M; Pintilie, I

2014-01-01

Using forward current injection with densities in the range 15-30A/cm(2) we can effectively eliminate the radiation-induced boron-oxygen complex, which is the main compensating center in irradiated Si solar cells. It was found that for a given forward current density the elimination rate is decreasing with increasing irradiation dose. Additionally, some evidences have been obtained on the negative-U properties of the radiation-induced boron-oxygen complex.

Reward modulates perception in binocular rivalry.

Science.gov (United States)

Marx, Svenja; Einhäuser, Wolfgang

2015-01-14

Our perception does not provide us with an exact imprint of the outside world, but is continuously adapted to our internal expectations, task sets, and behavioral goals. Although effects of reward-or value in general-on perception therefore seem likely, how valuation modulates perception and how such modulation relates to attention is largely unknown. We probed effects of reward on perception by using a binocular-rivalry paradigm. Distinct gratings drifting in opposite directions were presented to each observer's eyes. To objectify their subjective perceptual experience, the optokinetic nystagmus was used as measure of current perceptual dominance. In a first experiment, one of the percepts was either rewarded or attended. We found that reward and attention similarly biased perception. In a second experiment, observers performed an attentionally demanding task either on the rewarded stimulus, the other stimulus, or both. We found that-on top of an attentional effect on perception-at each level of attentional load, reward still modulated perception by increasing the dominance of the rewarded percept. Similarly, penalizing one percept increased dominance of the other at each level of attentional load. In turn, rewarding-and similarly nonpunishing-a percept yielded performance benefits that are typically associated with selective attention. In conclusion, our data show that value modulates perception in a similar way as the volitional deployment of attention, even though the relative effect of value is largely unaffected by an attention task. © 2015 ARVO.

The effects of magnetite (Fe3O4 nanoparticles on electroporation-induced inward currents in pituitary tumor (GH3 cells and in RAW 264.7 macrophages

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Liu YC

2012-03-01

Full Text Available Yen-Chin Liu1, Ping-Ching Wu2, Dar-Bin Shieh2–5, Sheng-Nan Wu3,6,71Department of Anesthesiology, 2Institute of Oral Medicine and Department of Stomatology, 3Department of Physiology, National Cheng Kung University Hospital, College of Medicine, 4Advanced Optoelectronic Technology Center, 5Center for Micro/Nano Science and Technology, National Cheng Kung University, 6Innovation Center for Advanced Medical Device Technology, National Cheng Kung University, 7Department of Anatomy and Cell Biology, National Cheng Kung University Medical College, Tainan, TaiwanAims: Fe3O4 nanoparticles (NPs have been known to provide a distinct image contrast effect for magnetic resonance imaging owing to their super paramagnetic properties on local magnetic fields. However, the possible effects of these NPs on membrane ion currents that concurrently induce local magnetic field perturbation remain unclear.Methods: We evaluated whether amine surface-modified Fe3O4 NPs have any effect on ion currents in pituitary tumor (GH3 cells via voltage clamp methods.Results: The addition of Fe3O4 NPs decreases the amplitude of membrane electroporation-induced currents (IMEP with a half-maximal inhibitory concentration at 45 µg/mL. Fe3O4 NPs at a concentration of 3 mg/mL produced a biphasic response in the amplitude of IMEP, ie, an initial decrease followed by a sustained increase. A similar effect was also noted in RAW 264.7 macrophages.Conclusion: The modulation of magnetic electroporation-induced currents by Fe3O4 NPs constitutes an important approach for cell tracking under various imaging modalities or facilitated drug delivery.Keywords: iron oxide, ion current, free radical

The effect of electron range on electron beam induced current collection and a simple method to extract an electron range for any generation function

International Nuclear Information System (INIS)

Lahreche, A.; Beggah, Y.; Corkish, R.

2011-01-01

The effect of electron range on electron beam induced current (EBIC) is demonstrated and the problem of the choice of the optimal electron ranges to use with simple uniform and point generation function models is resolved by proposing a method to extract an electron range-energy relationship (ERER). The results show that the use of these extracted electron ranges remove the previous disagreement between the EBIC curves computed with simple forms of generation model and those based on a more realistic generation model. The impact of these extracted electron ranges on the extraction of diffusion length, surface recombination velocity and EBIC contrast of defects is discussed. It is also demonstrated that, for the case of uniform generation, the computed EBIC current is independent of the assumed shape of the generation volume. -- Highlights: → Effect of electron ranges on modeling electron beam induced current is shown. → A method to extract an electron range for simple form of generation is proposed. → For uniform generation the EBIC current is independent of the choice of it shape. → Uses of the extracted electron ranges remove some existing literature ambiguity.

Motion-induced eddy current thermography for high-speed inspection

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Jianbo Wu

2017-08-01

Full Text Available This letter proposes a novel motion-induced eddy current based thermography (MIECT for high-speed inspection. In contrast to conventional eddy current thermography (ECT based on a time-varying magnetic field created by an AC coil, the motion-induced eddy current is induced by the relative motion between magnetic field and inspected objects. A rotating magnetic field created by three-phase windings is used to investigate the heating principle and feasibility of the proposed method. Firstly, based on Faraday’s law the distribution of MIEC is investigated, which is then validated by numerical simulation. Further, experimental studies are conducted to validate the proposed method by creating rotating magnetic fields at different speeds from 600 rpm to 6000 rpm, and it is verified that rotating speed will increase MIEC intensity and thereafter improve the heating efficiency. The conclusion can be preliminarily drawn that the proposed MIECT is a platform suitable for high-speed inspection.

Radiation-induced bystander effects. Mechanisms, biological implications, and current investigations at the Leipzig LIPSION facility

International Nuclear Information System (INIS)

Oesterreicher, J.; Prise, K.M.; Michael, B.D.; Vogt, J.; Butz, T.; Tanner, J.M.

2003-01-01

Background: The bystander effect is a relatively new area of radiobiological research, which is aimed at studying post-radiation changes in neighboring non-hit cells or tissues. The bystander effect of ionizing irradiation is important after low-dose irradiation in the range of up to 0.2 Gy, where a higher incidence of stochastic damage was observed than was expected from a linear-quadratic model. It is also important when the irradiation of a cell population is highly non-uniform. Objective: This review summarizes most of the important results and proposed bystander effect mechanisms as well as their impact on theory and clinical practice. The literature, in parts contradictory, is collected, the main topics are outlined, and some basic papers are described in more detail. In order to illustrate the microbeam technique, which is considered relevant for the bystander effect research, the state of the Leipzig LIPSION nanoprobe facility is described. Results: The existence of a radiation-induced bystander effect is now generally accepted. The current state of knowledge on it is summarized here. Several groups worldwide are working on understanding its different aspects and its impact on radiobiology and radiation protection. Conclusion: The observation of a bystander effect has posed many questions, and answering them is a challenging topic for radiobiology in the future. (orig.)

Radiation-induced bystander effects. Mechanisms, biological implications, and current investigations at the Leipzig LIPSION facility

Energy Technology Data Exchange (ETDEWEB)

Oesterreicher, J. [Dept. of Nuclear Solid State Physics, Univ. of Leipzig (Germany); Dept. of Radiobiology and Immunology, Purkyne Military Medical Academy, Hradec Kralove (Czech Republic); Prise, K.M.; Michael, B.D. [Gray Cancer Inst., Mount Vernon Hospital, Northwood, Middlesex (United Kingdom); Vogt, J.; Butz, T. [Dept. of Nuclear Solid State Physics, Univ. of Leipzig (Germany); Tanner, J.M. [Clinic and Polyclinic of Radiation Oncology, Martin Luther Univ. Halle-Wittenberg (Germany)

2003-02-01

Background: The bystander effect is a relatively new area of radiobiological research, which is aimed at studying post-radiation changes in neighboring non-hit cells or tissues. The bystander effect of ionizing irradiation is important after low-dose irradiation in the range of up to 0.2 Gy, where a higher incidence of stochastic damage was observed than was expected from a linear-quadratic model. It is also important when the irradiation of a cell population is highly non-uniform. Objective: This review summarizes most of the important results and proposed bystander effect mechanisms as well as their impact on theory and clinical practice. The literature, in parts contradictory, is collected, the main topics are outlined, and some basic papers are described in more detail. In order to illustrate the microbeam technique, which is considered relevant for the bystander effect research, the state of the Leipzig LIPSION nanoprobe facility is described. Results: The existence of a radiation-induced bystander effect is now generally accepted. The current state of knowledge on it is summarized here. Several groups worldwide are working on understanding its different aspects and its impact on radiobiology and radiation protection. Conclusion: The observation of a bystander effect has posed many questions, and answering them is a challenging topic for radiobiology in the future. (orig.)

Radiation-induced off-state leakage current in commercial power MOSFETs

International Nuclear Information System (INIS)

Dodd, Paul Emerson; Shaneyfelt, Marty Ray; Draper, Bruce Leroy; Felix, James Andrew; Schwank, James Ralph; Dalton, Scott Matthew

2005-01-01

The total dose hardness of several commercial power MOSFET technologies is examined. After exposure to 20 krad(SiO 2 ) most of the n- and p-channel devices examined in this work show substantial (2 to 6 orders of magnitude) increases in off-state leakage current. For the n-channel devices, the increase in radiation-induced leakage current follows standard behavior for moderately thick gate oxides, i.e., the increase in leakage current is dominated by large negative threshold voltage shifts, which cause the transistor to be partially on even when no bias is applied to the gate electrode. N-channel devices biased during irradiation show a significantly larger leakage current increase than grounded devices. The increase in leakage current for the p-channel devices, however, was unexpected. For the p-channel devices, it is shown using electrical characterization and simulation that the radiation-induced leakage current increase is related to an increase in the reverse bias leakage characteristics of the gated diode which is formed by the drain epitaxial layer and the body. This mechanism does not significantly contribute to radiation-induced leakage current in typical p-channel MOS transistors. The p-channel leakage current increase is nearly identical for both biased and grounded irradiations and therefore has serious implications for long duration missions since even devices which are usually powered off could show significant degradation and potentially fail.

Numerical study of induced current perturbations in the vicinity of excitable cells exposed to extremely low frequency magnetic fields

International Nuclear Information System (INIS)

Hassan, Noha; Chatterjee, Indira; Publicover, Nelson G; Craviso, Gale L

2003-01-01

Realistic three-dimensional cell morphologies were modelled to determine the current density induced in excitable cell culture preparations exposed to 60 Hz magnetic fields and to identify important factors that can influence the responses of cells to these fields. Cell morphologies representing single spherical adrenal chromaffin cells, single elongated smooth muscle cells and chromaffin cell aggregates in a Petri dish containing culture medium were modelled using the finite element method. The computations for a spherical cell revealed alterations in the magnitude and spatial distribution of the induced current density in the immediate vicinity of the cell. Maxima occurred at the equatorial sides and minima at the poles. Proximity of cells to each other as well as cell aggregate shape, size and orientation with respect to the induced current influenced the magnitude and spatial distribution of the induced current density. For an elongated cell, effects on the induced current density were highly dependent on cell orientation with respect to the direction of the induced current. These results provide novel insights into the perturbations in induced current that occur in excitable cell culture preparations and lay a foundation for understanding the mechanisms of interaction with extremely low frequency magnetic fields at the tissue level

Power of the Desired Self: Influence of Induced Perceptions of the Self on Reasoning

Science.gov (United States)

Augustinova, Maria; Collange, Julie; Sanitioso, Rasyid Bo; Musca, Serban C.

2011-01-01

This research shows that the motivation to posses a desired characteristic (or to avoid an undesired one) results in self-perceptions that guide people's use of base rate in the Lawyer-Engineer problem (Kahneman & Tversky, 1973). In four studies, participants induced to believe (or recall, Exp. 2) that a rational cognitive style is…

Space Weather Effects Produced by the Ring Current Particles

Science.gov (United States)

Ganushkina, Natalia; Jaynes, Allison; Liemohn, Michael

2017-11-01

One of the definitions of space weather describes it as the time-varying space environment that may be hazardous to technological systems in space and/or on the ground and/or endanger human health or life. The ring current has its contributions to space weather effects, both in terms of particles, ions and electrons, which constitute it, and magnetic and electric fields produced and modified by it at the ground and in space. We address the main aspects of the space weather effects from the ring current starting with brief review of ring current discovery and physical processes and the Dst-index and predictions of the ring current and storm occurrence based on it. Special attention is paid to the effects on satellites produced by the ring current electrons. The ring current is responsible for several processes in the other inner magnetosphere populations, such as the plasmasphere and radiation belts which is also described. Finally, we discuss the ring current influence on the ionosphere and the generation of geomagnetically induced currents (GIC).

The effects of solar-geomagnetically induced currents on electrical systems in nuclear power stations

International Nuclear Information System (INIS)

Subudhi, M.; Carroll, D.P.; Kasturi, S.

1994-01-01

This report presents the results of a study to evaluate the potential effects of geomagnetically induced currents (GICs) caused by the solar disturbances on the in-plant electrical distribution system and equipment in nuclear power stations. The plant-specific electrical distribution system for a typical nuclear plant is modeled using the ElectroMagnetic Transient Program (EMTP). The computer model simulates online equipment and loads from the station transformer in the switchyard of the power station to the safety-buses at 120 volts to which all electronic devices are connected for plant monitoring. The analytical model of the plant's electrical distribution system is studied to identify the transient effects caused by the half-cycle saturation of the station transformers due to GIC. This study provides results of the voltage harmonics levels that have been noted at various electrical buses inside the plant. The emergency circuits appear to be more susceptible to high harmonics due to the normally light load conditions. In addition to steady-state analysis, this model was further analyzed simulating various plant transient conditions (e.g., loss of load or large motor start-up) occurring during GIC events. Detail models of the plant's protective relaying system employed in bus transfer application were included in this model to study the effects of the harmonic distortion of the voltage input. Potential harmonic effects on the uniterruptable power system (UPS) are qualitatively discussed as well

Nonconservative current-induced forces: A physical interpretation

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Tchavdar N. Todorov

2011-10-01

Full Text Available We give a physical interpretation of the recently demonstrated nonconservative nature of interatomic forces in current-carrying nanostructures. We start from the analytical expression for the curl of these forces, and evaluate it for a point defect in a current-carrying system. We obtain a general definition of the capacity of electrical current flow to exert a nonconservative force, and thus do net work around closed paths, by a formal noninvasive test procedure. Second, we show that the gain in atomic kinetic energy over time, generated by nonconservative current-induced forces, is equivalent to the uncompensated stimulated emission of directional phonons. This connection with electron–phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.

Nano-electron beam induced current and hole charge dynamics through uncapped Ge nanocrystals

Energy Technology Data Exchange (ETDEWEB)

Marchand, A.; El Hdiy, A.; Troyon, M. [Laboratoire de Recherche en Nanosciences, Bat. 6, case no 15, UFR Sciences, Universite de Reims Champagne Ardenne, 51687 Reims Cedex 2 (France); Amiard, G.; Ronda, A.; Berbezier, I. [IM2NP, Faculte des Sciences et Techniques, Campus de Saint Jerome - Case 142, Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20 (France)

2012-04-16

Dynamics of hole storage in spherical Ge nanocrystals (NCs) formed by a two step dewetting/nucleation process on an oxide layer grown on an n-doped <001> silicon substrate is studied using a nano-electron beam induced current technique. Carrier generation is produced by an electron beam irradiation. The generated current is collected by an atomic force microscope--tip in contact mode at a fixed position away from the beam spot of about 0.5 {mu}m. This distance represents the effective diffusion length of holes. The time constants of holes charging are determined and the effect of the NC size is underlined.

Safety considerations to avoid current-induced skin burns in MRI

International Nuclear Information System (INIS)

Knopp, M.V.; Metzner, R.; Kaick, G. van; Brix, G.; Bundesamt fuer Strahlenschutz, Oberschleissheim

1998-01-01

The safety aspects of radiological methods continue to evolve. In this paper we report on two cases of skin burns in MRI caused by induced electrical current. A second- and a third-degree skin burn occurred during imaging in a 1.5 T system. The electromagnetic radiofrequency field inadvertently led to electrical currents caused by a conducting loop through the extremities and trunk. Skin burns induced by electrical current may occur in extremely rare cases even with standard MR imaging protocols operating within all current safety guidelines by inadvertently forming a closed conducting loop. By avoiding focal skin to skin contact of the extremities, this extremely rare adverse event can be avoided. (orig.) [de

Radiation induced currents in MRI RF coils: application to linac/MRI integration

Science.gov (United States)

Burke, B.; Fallone, B. G.; Rathee, S.

2010-02-01

The integration of medical linear accelerators (linac) with magnetic resonance imaging (MRI) systems is advancing the current state of image-guided radiotherapy. The MRI in these integrated units will provide real-time, accurate tumor locations for radiotherapy treatment, thus decreasing geometric margins around tumors and reducing normal tissue damage. In the real-time operation of these integrated systems, the radiofrequency (RF) coils of MRI will be irradiated with radiation pulses from the linac. The effect of pulsed radiation on MRI radio frequency (RF) coils is not known and must be studied. The instantaneous radiation induced current (RIC) in two different MRI RF coils were measured and presented. The frequency spectra of the induced currents were calculated. Some basic characterization of the RIC was also done: isolation of the RF coil component responsible for RIC, dependence of RIC on dose rate, and effect of wax buildup placed on coil on RIC. Both the time and frequency characteristics of the RIC were seen to vary with the MRI RF coil used. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence on dose rate was seen. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. This study shows a measurable RIC present in MRI RF coils. This unwanted current could be possibly detrimental to the signal to noise ratio in MRI and produce image artifacts.

The Effect of Comparatively-Framed versus Similarity-Framed E-Cigarette and Snus Print Ads on Young Adults' Ad and Product Perceptions.

Science.gov (United States)

Banerjee, Smita C; Greene, Kathryn; Li, Yuelin; Ostroff, Jamie S

2016-07-01

This study examined the effects of comparative-framing [C-F; ads highlighting differences between the advertised product and conventional cigarettes and/or smokeless tobacco products] versus similarity-framing (S-F; ads highlighting congruence with conventional cigarettes and/or smokeless tobacco products) in e-cigarette and snus ads on young adult smokers' and non-smokers' ad- and product-related perceptions. One thousand fifty one (1,051) young adults (18-24 years; 76% women; 50% smokers) from existing consumer panels were recruited in a within-subjects quasi-experiment. Each participant viewed 4 online advertisements, varied by tobacco product type (e-cigarette or snus) and ad framing (C-F or S-F). The dependent measures for this study were ad-related (ad perceptions, ad credibility) and product-related perceptions (absolute and comparative risk perceptions, product appeal, and product use intentions). Former and current smokers rated C-F ads as more persuasive than S-F ads, as evidenced by favorable ad perceptions and high product use intentions. Former and current smokers also rated e-cigarette ads with more favorable ad perceptions, low absolute and comparative risk perceptions, high product appeal, and high product use intentions as compared to snus ads. However, the effect sizes of the significant differences are less than.2, indicating small magnitude of difference between the study variables. Unless FDA regulates e-cig and snus advertising, there is a potential of decreasing risk perceptions and increasing use of e-cigs among young adults. Further research on implicit/explicit comparative claims in e-cigarettes and snus advertisements that encourage risk misperceptions is recommended.

From sensation to percept: the neural signature of auditory event-related potentials.

Science.gov (United States)

Joos, Kathleen; Gilles, Annick; Van de Heyning, Paul; De Ridder, Dirk; Vanneste, Sven

2014-05-01

An external auditory stimulus induces an auditory sensation which may lead to a conscious auditory perception. Although the sensory aspect is well known, it is still a question how an auditory stimulus results in an individual's conscious percept. To unravel the uncertainties concerning the neural correlates of a conscious auditory percept, event-related potentials may serve as a useful tool. In the current review we mainly wanted to shed light on the perceptual aspects of auditory processing and therefore we mainly focused on the auditory late-latency responses. Moreover, there is increasing evidence that perception is an active process in which the brain searches for the information it expects to be present, suggesting that auditory perception requires the presence of both bottom-up, i.e. sensory and top-down, i.e. prediction-driven processing. Therefore, the auditory evoked potentials will be interpreted in the context of the Bayesian brain model, in which the brain predicts which information it expects and when this will happen. The internal representation of the auditory environment will be verified by sensation samples of the environment (P50, N100). When this incoming information violates the expectation, it will induce the emission of a prediction error signal (Mismatch Negativity), activating higher-order neural networks and inducing the update of prior internal representations of the environment (P300). Copyright © 2014 Elsevier Ltd. All rights reserved.

Ion induced intermixing and consequent effects on the leakage currents in HfO{sub 2}/SiO{sub 2}/Si systems

Energy Technology Data Exchange (ETDEWEB)

Manikanthababu, N.; Saikiran, V.; Pathak, A.P.; Rao, S.V.S.N. [University of Hyderabad, School of Physics, Hyderabad (India); Chan, T.K.; Vajandar, S.; Osipowicz, T. [National University of Singapore, Department of Physics, Centre for Ion Beam Applications (CIBA), Singapore (Singapore)

2017-05-15

Atomic layer deposited (ALD) samples with layer stacks of HfO{sub 2} (3 nm)/SiO{sub 2} (0.7 nm)/Si were subjected to 120 MeV Au ion irradiation at different fluences to study intermixing effects across the HfO{sub 2}/SiO{sub 2} interface. High-resolution Rutherford backscattering spectrometry (HRBS) and X-ray reflectivity (XRR) measurements confirm an increase in the interlayer thickness as a result of SHI induced intermixing effects. Current-voltage (I-V) measurements reveal an order of magnitude difference in the leakage current density between the pristine and irradiated samples. This can be explained by considering the increased physical thickness of interlayer (HfSiO). Furthermore, the samples were subjected to rapid thermal annealing (RTA) process to analyze annealing kinetics. (orig.)

Effect of hall currents on thermal instability of dusty couple stress fluid

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Aggarwal Amrish Kumar

2016-09-01

Full Text Available In this paper, effect of Hall currents on the thermal instability of couple-stress fluid permeated with dust particles has been considered. Following the linearized stability theory and normal mode analysis, the dispersion relation is obtained. For the case of stationary convection, dust particles and Hall currents are found to have destabilizing effect while couple stresses have stabilizing effect on the system. Magnetic field induced by Hall currents has stabilizing/destabilizing effect under certain conditions. It is found that due to the presence of Hall currents (hence magnetic field, oscillatory modes are produced which were non-existent in their absence.

Brain mechanisms of abnormal temperature perception in cold allodynia induced by ciguatoxin.

Science.gov (United States)

Eisenblätter, Anneka; Lewis, Richard; Dörfler, Arnd; Forster, Clemens; Zimmermann, Katharina

2017-01-01

Cold allodynia occurs as a major symptom of neuropathic pain states. It remains poorly treated with current analgesics. Ciguatoxins (CTXs), ichthyosarcotoxins that cause ciguatera, produce a large peripheral sensitization to dynamic cold stimuli in Aδ-fibers by activating sodium channels without producing heat or mechanical allodynia. We used CTXs as a surrogate model of cold allodynia to dissect the framework of cold allodynia-activated central pain pathways. Reversible cold allodynia was induced in healthy male volunteers by shallow intracutaneous injection of low millimolar concentrations of CTX into the dorsal skin of the forefoot. Cold and warm stimuli were delivered to the treated and the control site using a Peltier-driven thermotest device. Functional magnetic resonance imaging (fMRI) scans were acquired with a 3T MRI scanner using a blood oxygen level-dependent (BOLD) protocol. The CTX-induced substantial peripheral sensitization to cooling stimuli in Aδ-fibers is particularly retrieved in BOLD changes due to dynamic temperature changes and less during constant cooling. Brain areas that responded during cold allodynia were almost always located bilaterally and appeared in the medial insula, medial cingulate cortex, secondary somatosensory cortex, frontal areas, and cerebellum. Whereas these areas also produced changes in BOLD signal during the dynamic warming stimulus on the control site, they remained silent during the warming stimuli on the injected site. We describe the defining feature of the cold allodynia pain percept in the human brain and illustrate why ciguatera sufferers often report a perceptual temperature reversal. ANN NEUROL 2017;81:104-116. © 2016 American Neurological Association.

Public perceptions and acceptance of induced earthquakes related to energy development

International Nuclear Information System (INIS)

McComas, Katherine A.; Lu, Hang; Keranen, Katie M.; Furtney, Maria A.; Song, Hwansuck

2016-01-01

Growing awareness of the potential for some energy-related activities to induce earthquakes has created a need to understand how the public evaluates the risks of induced earthquakes versus the benefits of energy development. To address this need, this study presents a web survey that used a between-subjects factorial experimental design to explore the views of 325 U.S. adults, who were asked about their experiences with earthquakes; risk perceptions related to different causes of earthquakes (e.g., natural versus induced); and acceptability of earthquakes depending on the benefits, beneficiaries, and decision making process. The results found that participants had more negative feelings toward induced versus naturally occurring earthquakes. Although they judged no earthquake as “acceptable,” participants rated induced earthquakes significantly less acceptable than naturally occurring ones. Attributing the benefits to the provision of renewable energy or climate change mitigation did not increase induced earthquake acceptability, and no particular beneficiary made earthquakes more acceptable, although private companies as beneficiaries made earthquakes less acceptable. Finally, induced earthquake acceptability was significantly higher when people believed that people like them had a voice in the decision to implement the technology that caused the earthquake, underscoring the importance of public engagement in the development of energy technologies. - Highlights: • Human induced earthquakes were perceived as more negative than natural earthquakes. • Attributing benefits to renewable energy did not increase earthquake acceptability. • Acceptability was highest after a procedurally fair decision making process. • Acceptability was lowest following an expert-driven decision.

Effects of Rational-Emotive Health Education Program on HIV risk perceptions among in-school adolescents in Nigeria.

Science.gov (United States)

Onyechi, Kay Chinonyelum Nwamaka; Eseadi, Chiedu; Okere, Anthony U; Otu, Mkpoikanke Sunday

2016-07-01

Exploring beliefs about personal risk for human immunodeficiency virus (HIV) infection is essential to understanding what motivates people to engage in behaviors that reduce or increase their risk of HIV infection. Therefore, the current study's objective was to examine the effects of a Rational-Emotive Health Education Program (REHEP) on HIV risk perceptions among in-school adolescents in Anambra State, Nigeria.Forty-four participants were identified as having high-risk perceptions about HIV infection through a self-report questionnaire and met the inclusion criteria. The treatment process was guided by a REHEP manual and consisted of 8 weeks of full intervention and 2 weeks of follow-up meetings that marked the end of intervention. The study used repeated measures analysis of variance to assess improvements in individual participants and across control and treatment group risk perceptions after the intervention.HIV risk perceptions of in-school adolescents did not differ across the treatment and control groups at baseline. Through REHEP, HIV risk perceptions significantly reduced in the treatment group compared to those in the control group. REHEP had significant effect on HIV risk perceptions of in-school adolescents exposed to treatment group, despite their sex. Religious background did not determine the significant effect of REHEP on HIV risk perceptions of in-school adolescents in the treatment group.Follow-up studies that would use a REHEP to assist client population from other parts of the country to promote HIV risk reduction, especially among those with high-risk behavior, are needed in Nigeria.

The current perception threshold among rice farmers in Muda, Kedah and fishermen in Setiu, Terengganu

International Nuclear Information System (INIS)

Syarif Husin Lubis; Uttaman ABdullah; Nezrul Hisham Abdul Ghani; Mohd Rafaai Mohd Jamil; Salmaan Hussain Inayat Hussain

2002-01-01

A cross sectional study was conducted to investigate the effects of pesticide exposure on the current perception threshold (CPT) among 148 rice farmers in the Muda area Kedah and 85 fishermen in Setiu, Terengganu. The duration of pesticide exposure among the farmers was between 5 to 20 years. The CPT values were measured using a portable constant current electric nerve stimulator Neurometer CPT/Eagle, on the index finger (median digital nerve) and the great toe (perineal digital nerve) with three neuro selective frequency range (2000 Hz, 250 Hz, and 5 Hz). The CPT values were significantly elevated among farmers for all frequencies (2000 Hz, 250 Hz and 5 Hz) for both measurement sites (index finger and great toe). The range of the probability was between P<0.002 and P<0.0001. The selective involvement of the large diameter myelinated sensory fibres (2000 Hz and 250 Hz) and small diameter unmyelinated sensory fibres (5 Hz) were reflective of toxic peripheral neuropathy in exposed farmers. The CPT on the media nerve and perineal nerve between exposed farmers and none exposed fishermen is significantly different and thus the measurement of CPT can be used as a marker to determine and monitor the effects of pesticide exposure among the farmers. (Author)

Are vegans the same as vegetarians? The effect of diet on perceptions of masculinity.

Science.gov (United States)

Thomas, Margaret A

2016-02-01

Food and food consumption matters in interpersonal interactions. Foods consumed can affect how a person is perceived by others in terms of morality, likeability, and gender. Food consumption can be used as a strategy for gendered presentation, either in terms of what foods are consumed or in the amount of food consumed. Finally, foods themselves are associated with gender. Previous research (Browarnik, 2012; Ruby & Heine, 2011) shows inconsistent patterns in the association between vegetarianism and masculinity. The current research conceptually replicates and extends this research by including the explicit label of vegetarian. The four studies in this article provide increased information about the effects of diet on gendered perceptions. Study 1 shows that vegetarian and omnivorous targets are rated equally in terms of masculinity. Study 2 shows that perceptions of vegetarians and vegans are similar, though comparing this research with past research indicates that perceptions of vegetarians are more variable. Study 3 shows that veganism leads perceptions of decreased masculinity relative to omnivores. Finally, Study 4 tests one possible mechanism for the results of Study 3, that it is the choice to be vegan that impacts perceptions of gender. Implications include increased knowledge about how meatless diets can affect the perceptions of gender in others. Multiple directions for future research are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pharmacological and Expectancy Effects of a Low Amount of Alcohol Drinking on Outcome Valuation and Risk Perception in Males and Females

Science.gov (United States)

Tsurugizawa, Tomokazu; Tokuda, Shinsuke; Harada, Tokiko; Takahashi, Taiki; Sadato, Norihiro

2016-01-01

The high-dose, alcohol-induced influences on risk perception and loss aversion depend on sex. On the other hand, low-dose alcohol has less effect on risky behavior. However, the effect of low-dose alcohol on subjective valuation of gain or loss and also the effect of placebo (expectancy of alcohol) on risk perception have not been fully investigated. We investigated the effects of low-dose alcohol (0.02 g/100 ml blood alcohol concentration) and placebo effects on subjective risk perception and subjective valuation of uncertain gain and loss in females and males. Participants in the control group and the placebo group were served alcohol-free, wine-flavored beverage and participants of alcohol group were served wine (14% alcohol). The placebo group was not informed that the drink was not alcohol but the control group was informed. Then paper–pencil tasks for subjective risk perception and valuation of gain or loss were performed 45 min after drinking the beverage. The participants were asked to draw the line on a 180 mm scale for each question. The placebo effects as well as the low-dose alcohol effects were observed in subjective valuations of gain or loss. Except for effect of beverages, a gender difference was also observed for subjective likelihood. The females estimated a low-probability loss as more likely and estimated a high-probability gain as less likely than did the males. From the Stevens’ law fitting analysis, the placebo, not alcohol, significantly induced the psychophysical effect of the subjective valuation of gain or loss. These results indicate that the psychological effects of expectancy of alcohol (placebo) could be a major factor in changing the subjective valuation of gain or loss over the pharmacological effects of a small amount of alcohol (like a glass of wine). Furthermore, these results also indicate that gender differences should be taken into account when investigating pharmacological or psychological effect on decision-making. PMID

Pharmacological and Expectancy Effects of a Low Amount of Alcohol Drinking on Outcome Valuation and Risk Perception in Males and Females.

Directory of Open Access Journals (Sweden)

Tomokazu Tsurugizawa

Full Text Available The high-dose, alcohol-induced influences on risk perception and loss aversion depend on sex. On the other hand, low-dose alcohol has less effect on risky behavior. However, the effect of low-dose alcohol on subjective valuation of gain or loss and also the effect of placebo (expectancy of alcohol on risk perception have not been fully investigated. We investigated the effects of low-dose alcohol (0.02 g/100 ml blood alcohol concentration and placebo effects on subjective risk perception and subjective valuation of uncertain gain and loss in females and males. Participants in the control group and the placebo group were served alcohol-free, wine-flavored beverage and participants of alcohol group were served wine (14% alcohol. The placebo group was not informed that the drink was not alcohol but the control group was informed. Then paper-pencil tasks for subjective risk perception and valuation of gain or loss were performed 45 min after drinking the beverage. The participants were asked to draw the line on a 180 mm scale for each question. The placebo effects as well as the low-dose alcohol effects were observed in subjective valuations of gain or loss. Except for effect of beverages, a gender difference was also observed for subjective likelihood. The females estimated a low-probability loss as more likely and estimated a high-probability gain as less likely than did the males. From the Stevens' law fitting analysis, the placebo, not alcohol, significantly induced the psychophysical effect of the subjective valuation of gain or loss. These results indicate that the psychological effects of expectancy of alcohol (placebo could be a major factor in changing the subjective valuation of gain or loss over the pharmacological effects of a small amount of alcohol (like a glass of wine. Furthermore, these results also indicate that gender differences should be taken into account when investigating pharmacological or psychological effect on decision-making.

Applying inversion techniques to derive source currents and geoelectric fields for geomagnetically induced current calculations

Directory of Open Access Journals (Sweden)

J. S. de Villiers

2014-10-01

Full Text Available This research focuses on the inversion of geomagnetic variation field measurement to obtain source currents in the ionosphere. During a geomagnetic disturbance, the ionospheric currents create magnetic field variations that induce geoelectric fields, which drive geomagnetically induced currents (GIC in power systems. These GIC may disturb the operation of power systems and cause damage to grounded power transformers. The geoelectric fields at any location of interest can be determined from the source currents in the ionosphere through a solution of the forward problem. Line currents running east–west along given surface position are postulated to exist at a certain height above the Earth's surface. This physical arrangement results in the fields on the ground having the magnetic north and down components, and the electric east component. Ionospheric currents are modelled by inverting Fourier integrals (over the wavenumber of elementary geomagnetic fields using the Levenberg–Marquardt technique. The output parameters of the inversion model are the current strength, height and surface position of the ionospheric current system. A ground conductivity structure with five layers from Quebec, Canada, based on the Layered-Earth model is used to obtain the complex skin depth at a given angular frequency. This paper presents preliminary and inversion results based on these structures and simulated geomagnetic fields. The results show some interesting features in the frequency domain. Model parameters obtained through inversion are within 2% of simulated values. This technique has applications for modelling the currents of electrojets at the equator and auroral regions, as well as currents in the magnetosphere.

Current bistability in a weakly coupled multi-quantum well structure: a magnetic field induced 'memory effect'

International Nuclear Information System (INIS)

Feu, W H M; Villas-Boas, J M; Cury, L A; Guimaraes, P S S; Vieira, G S; Tanaka, R Y; Passaro, A; Pires, M P; Landi, S M; Souza, P L

2009-01-01

A study of magnetotunnelling in weakly coupled multi-quantum wells reveals a new phenomenon which constitutes a kind of memory effect in the sense that the electrical resistance of the sample after application of the magnetic field is different from before and contains the information that a magnetic field was applied previously. The change in the electric field domain configuration triggered by the magnetic field was compared for two samples, one strictly periodic and another with a thicker quantum well inserted into the periodic structure. For applied biases at which two electric field domains are present in the sample, as the magnetic field is increased a succession of discontinuous reductions in the electrical resistance is observed due to the magnetic field-induced rearrangement of the electric field domains, i.e. the domain boundary jumps from well to well as the magnetic field is changed. The memory effect is revealed for the aperiodic structure as the electric field domain configuration triggered by the magnetic field remains stable after the field is reduced back to zero. This effect is related to the multi-stability in the current-voltage characteristics observed in some weakly coupled multi-quantum well structures.

Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

Science.gov (United States)

Luengo-Kovac, M.; Huang, S.; Del Gaudio, D.; Occena, J.; Goldman, R. S.; Raimondi, R.; Sih, V.

2017-11-01

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in InxGa1 -xAs epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin-polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to reproduce the experimental finding that the crystal direction with the smaller net spin-orbit field has larger electrical spin generation efficiency and are used to predict how sample parameters affect the magnitude of the current-induced spin polarization.

College Advising: Current Perceptions, Future Directions.

Science.gov (United States)

Chapman, David W.; Gill, Stephen J.

1981-01-01

Examines the college admissions activities that high school counselors believe are most effective in providing accurate information to students. Also examines the current role of the counselor in college advising and reports on what counselors predict will be the trends in college advising. (Author/RC)

The Effect of Comparatively-Framed versus Similarity-Framed E-Cigarette and Snus Print Ads on Young Adults’ Ad and Product Perceptions

Science.gov (United States)

Banerjee, Smita C.; Greene, Kathryn; Li, Yuelin; Ostroff, Jamie S.

2016-01-01

Objectives This study examined the effects of comparative-framing [C-F; ads highlighting differences between the advertised product and conventional cigarettes and/or smokeless tobacco products] versus similarity-framing (S-F; ads highlighting congruence with conventional cigarettes and/or smokeless tobacco products) in e-cigarette and snus ads on young adult smokers’ and non-smokers’ ad- and product-related perceptions. Methods One thousand fifty one (1,051) young adults (18–24 years; 76% women; 50% smokers) from existing consumer panels were recruited in a within-subjects quasi-experiment. Each participant viewed 4 online advertisements, varied by tobacco product type (e-cigarette or snus) and ad framing (C-F or S-F). The dependent measures for this study were ad-related (ad perceptions, ad credibility) and product-related perceptions (absolute and comparative risk perceptions, product appeal, and product use intentions). Results Former and current smokers rated C-F ads as more persuasive than S-F ads, as evidenced by favorable ad perceptions and high product use intentions. Former and current smokers also rated e-cigarette ads with more favorable ad perceptions, low absolute and comparative risk perceptions, high product appeal, and high product use intentions as compared to snus ads. However, the effect sizes of the significant differences are less than.2, indicating small magnitude of difference between the study variables. Conclusions Unless FDA regulates e-cig and snus advertising, there is a potential of decreasing risk perceptions and increasing use of e-cigs among young adults. Further research on implicit/explicit comparative claims in e-cigarettes and snus advertisements that encourage risk misperceptions is recommended. PMID:28042597

Effects of Sleeve Gastrectomy vs. Roux-en-Y Gastric Bypass on Eating Behavior and Sweet Taste Perception in Subjects with Obesity

Directory of Open Access Journals (Sweden)

Katie Nance

2017-12-01

Full Text Available The goal of this study was to test the hypothesis that weight loss induced by Roux-en-Y gastric bypass (RYGB has greater effects on taste perception and eating behavior than comparable weight loss induced by sleeve gastrectomy (SG. We evaluated the following outcomes in 31 subjects both before and after ~20% weight loss induced by RYGB (n = 23 or SG (n = 8: (1 sweet, savory, and salty taste sensitivity; (2 the most preferred concentrations of sucrose and monosodium glutamate; (3 sweetness palatability, by using validated sensory testing techniques; and (4 eating behavior, by using the Food Craving Inventory and the Dutch Eating Behavior Questionnaire. We found that neither RYGB nor SG affected sweetness or saltiness sensitivity. However, weight loss induced by either RYGB or SG caused the same decrease in: (1 frequency of cravings for foods; (2 influence of emotions and external food cues on eating behavior; and (3 shifted sweetness palatability from pleasant to unpleasant when repetitively tasting sucrose (all p-values ≤ 0.01. Therefore, when matched on weight loss, SG and RYGB cause the same beneficial effects on key factors involved in the regulation of eating behavior and hedonic component of taste perception.

Pre-Service Science Teachers' Perception of the Principles of Scientific Research

Science.gov (United States)

Can, Sendil; Kaymakci, Güliz

2016-01-01

The purpose of the current study employing the survey method is to determine the pre-service science teachers' perceptions of the principles of scientific research and to investigate the effects of gender, grade level and the state of following scientific publications on their perceptions. The sampling of the current research is comprised of 125…

Students' perceptions of motivation in high school biology class: Informing current theories

Science.gov (United States)

McManic, Janet A.

The purpose of this study was to investigate students' perceptions of motivation to achieve while participating in general level high school biology classes. In a national poll of teacher's attitudes, student's motivation was a top concern of teachers (Elam, 1989). The student's perceptions of motivation are important to understand if improvements and advancements in motivation are to be implemented in the science classroom. This qualitative study was conducted in an urban high school that is located in a major metropolitan area in the southeast of the United States. The student body of 1100 is composed of Caucasian, African-American, Hispanic, and Asian students. The focus question of the study was: What are students' perceptions of their motivation in biology class? From general level biology classes, purposeful sampling narrowed the participants to fifteen students. Semi-structured interviews were conducted with the participants having varying measurements of motivation on the Scale of Intrinsic versus Extrinsic Orientation in the Classroom (Harter, 1980). The interviews were recorded and transcribed. After transcription, the interviews were coded by the constant comparative method (Glaser & Strauss, 1967). The coded data of students' responses were analyzed and compared to current theories of motivation. The current theories are the social-cognitive model (Bandura, 1977), attribution theory (Weiner, 1979), basic needs theory (Maslow, 1954) and choice theory (Glasser, 1986). The results of this study support the social cognitive model of motivation (Bandura, 1977) through the description of family structure and its relationship to motivation (Gonzalez, 2002). The study upheld previous research in that extrinsic orientation was shown to be prevalent in older students (Harter, 1981; Anderman & Maehr, 1994). In addition, the students' responses disclosed the difficulties encountered in studying biology. Students expressed the opinion that biology terms are

The effects of body posture, anatomy, age and pregnancy on the calculation of induced current densities at 50 Hz

International Nuclear Information System (INIS)

Dimbylow, P.; Findlay, R.

2010-01-01

This paper presents calculations of the induced current density in the body at 50 Hz from applied electric and magnetic fields. An extensive ensemble of 25 voxel models has been used to investigate the effects of body posture, anatomy, age and pregnancy. This set includes six adult models, eight child models and seven pregnant female models at various stages of gestation. The four postures investigated in the HPA adult model, NORMAN, were the standard position with the arms at the side, with the arms vertically above the head, the arms horizontally to the side and sitting. (authors)

The influence of perceptions of community norms on current contraceptive use among men and women in Ethiopia and Kenya.

Science.gov (United States)

Dynes, Michelle; Stephenson, Rob; Rubardt, Marcie; Bartel, Doris

2012-07-01

The paper uses data from Ethiopia and Kenya to examine how perceptions of community norms differentially shape contraceptive use among men and women. Women whose current number of sons is lower than their perception of the community ideal had lower odds of reporting contraceptive use, while women whose own personal ideal number of sons is lower than the community ideal had greater odds of reporting contraceptive use. Men and women in Kenya were influenced more by their perception of their social network's approval of family planning than by their own approval of family planning. Results highlight the importance of place, conceptualized as the place-specific perceptions of fertility ideals, when conducting reproductive health research. Identification of people who use contraception in the face of pervasive pronatalist community norms presents a point for future intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.

Soft X-ray beam induced current technique

Energy Technology Data Exchange (ETDEWEB)

Watts, B; Ade, H [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Queen, D; Hellman, F [Department of Physics, University of California, Berkeley, CA 94720 (United States); Kilcoyne, A L D; Tyliszczak, T, E-mail: benjamin.watts@gmail.co [Advanced Light Source, Lawrence Berkeley Nat. Lab., Berkeley, CA 94720 (United States)

2009-09-01

Direct mapping of the charge transport efficiency of polymer solar cell devices using a soft X-ray beam induced current (SoXBIC) method is described. By fabricating a polymer solar cell on an x-ray transparent substrate, we demonstrate the ability to map polymer composition and nanoscale structure within an operating solar cell device and to simultaneously measure the local charge transport efficiency via the short-circuit current. A simple model is calculated and compared to experimental SoXBIC data of a PFB:F8BT bulk-heterojunction device in order to gain greater insight into the device operation and physics.

The current perception threshold test differentiates categories of mechanical neck disorder.

Science.gov (United States)

Uddin, Zakir; MacDermid, Joy C; Galea, Victoria; Gross, Anita R; Pierrynowski, Michael R

2014-07-01

Cross-sectional discriminative analysis. To determine whether current perception threshold (CPT) can differentiate between categories of patients with mechanical neck disorders (MNDs). Neck pain is the third most common musculoskeletal disorder and affects a third of all adults each year. It can present as neck pain without musculoskeletal signs, neck pain with musculoskeletal signs but no neurological signs, or neck pain with neurological signs. CPT testing can assess altered sensory perception that may reflect neurological changes. Patients with MNDs (n = 106) were classified into 3 groups, based on a standardized musculoskeletal examination process performed by an experienced physiotherapist who was blinded to CPT scores. The 3 groups were defined as neck pain without musculoskeletal signs (MND I) (n = 60), neck pain with musculoskeletal signs (MND II) (n = 29), and neck pain with neurological signs (MND III) (n = 17). A rapid protocol of CPT testing was performed at 3 frequencies (5, 250, and 2000 Hz), using 3 dermatomal locations on the hand. A 1-way analysis of variance with post hoc comparison and effect sizes was calculated to compare the mean CPT scores between the groups. A binary logistic-regression model was used to predict probability of higher CPT in MND III and to create a receiver-operating-characteristic curve. Mean CPT differed significantly across the 3 MND groups (MND I, 9.7; MND II, 10.6; and MND III, 11.8; Pabnormal CPT in MND III had an estimated 73% sensitivity and 81% specificity; the odds ratio was 11.5 (P = .001) for the differentiation capacity of CPT between MND II and III, with a cutoff of 11. The area under the receiver-operating-characteristic curve was 0.84 (95% confidence interval: 0.72, 0.96; P<.001). CPT testing has moderate discriminatory accuracy, specificity, and sensitivity for classification of MND categories into neck pain with or without neurological signs. J Orthop Sports Phys Ther 2014;44(7):532-540. Epub 10 May 2014

Current methodologies for assessing seismically induced settlements in soil

International Nuclear Information System (INIS)

Ledbetter, R.

1983-08-01

Earthquake-induced surface settlements have ranged from 0.7 to 10 percent of layer thickness for the relatively few incidences where reliable estimates have been made of settlement magnitudes and soil conditions. Standard penetration test results obtained for pre-earthquake and postearthquake conditions in Japan show that relative densities have changed from 188 percent increase to 44 percent decrease. At present, there are no verified methods of seismic settlement analysis. However, there are current methods of analysis ranging from empirical to fully theoretical, which take into account a few to all of the major variables affecting seismically induced settlement behavior. This report reviews pertinent current knowledge and methodologies related to this subject. 69 references, 9 figures

Herbal medicines for the treatment of cancer chemotherapy-induced side effects.

Science.gov (United States)

Ohnishi, Shunsuke; Takeda, Hiroshi

2015-01-01

Accumulating evidence suggests that Japanese herbal medicines, called Kampo, have beneficial effects on cancer chemotherapy-induced side effects. Rikkunshito ameliorates cisplatin-induced anorexia through an antagonistic effect on the 5-HT receptors and by increasing the serum ghrelin levels. Hangeshashinto improves irinotecan-induced diarrhea and chemotherapy-induced mucositis by inhibiting the activity of β-glucuronidase as well as the synthesis of prostaglandin E2. Goshajinkigan prevents oxaliplatin-induced neurotoxicity, possibly through suppressing functional alterations of the transient receptor potential channels. In this review, we will summarize the currently available literature regarding the clinical efficacy and potential mechanisms of Kampo medicines in the treatment of cancer chemotherapy-induced side effects.

Motionally-induced electromagnetic fields generated by idealized ocean currents

Science.gov (United States)

Tyler, R. H.; Mysak, L. A.

Using the induction equation, we investigate the generation of electromagnetic fields by the motional electromagnetic induction due to ocean currents. In this paper, solutions are presented for a linear induction equation for the magnetic flux density vector which contains prescribed time-independent ocean current and conductivity fields. Once the magnetic flux density is known, the electric field and electric current density are easily obtained by differentiation. Solutions are given for several examples of idealized flow which include: 1) Vertically and horizontally sheared plane-parallel flow with depth-dependent conductivity; 2) A simple Stommel circulation gyre; and 3) Symmetric gyres. The results indicate that typical ocean current features induce magnetic fields with magnitudes reaching 100's of nT within the water and about 1-10 outside of the water. For the case of a field of gyres, the ocean-induced magnetic fields decay away from the ocean on spatial scales set by the horizontal scale of the ocean feature. At the altitudes of magnetic field satellite surveys, ocean-induced magnetic fields may retain values of a few nT, which are strong enough to be detected. Thus it is concluded that satellite observations of the earth's main magnetic field and, in particular, the observed temporal variations, could be affected by the ocean circulation. Summary and discussion In Section 3, we found exact solutions to the induction equation for idealized flows. The results gave magnitudes of about tens to hundreds of nT for the magnetic fields bH, about 10-5 V/m for the electric fields E, and about 10-5 A/m2 for the electric current density J induced by the ocean currents. These figures are in general agreement with the calculations of Lilley et al. (1993). In Section 4.2 we obtained solutions for the magnetic field above the ocean surface for the case of a Stommel gyre and a field of symmetric gyres. It was found in the last case that ocean gyres with a total transport

Effects of Transcranial Direct Current Stimulation, Transcranial Pulsed Current Stimulation, and Their Combination on Brain Oscillations in Patients with Chronic Visceral Pain: A Pilot Crossover Randomized Controlled Study

Directory of Open Access Journals (Sweden)

Aurore Thibaut

2017-11-01

Full Text Available ObjectiveChronic visceral pain (CVP syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different neuromodulation techniques in patients with CVP on cortical activity, through electreocephalography (EEG and on pain perception, through clinical tests.DesignA pilot crossover randomized controlled study.SettingsOut-patient.SubjectsAdults with CVP (>3 months.MethodsParticipants received four interventions in a randomized order: (1 transcranial pulsed current stimulation (tPCS and active transcranial direct current stimulation (tDCS combined, (2 tPCS alone, (3 tDCS alone, and (4 sham condition. Resting state quantitative electroencephalography (qEEG and pain assessments were performed before and after each intervention. Results were compared with a cohort of 47 healthy controls.ResultsWe enrolled six patients with CVP for a total of 21 visits completed. Compared with healthy participants, patients with CVP showed altered cortical activity characterized by increased power in theta, alpha and beta bands, and a significant reduction in the alpha/beta ratio. Regarding tES, the combination of tDCS with tPCS had no effect on power in any of the bandwidths, nor brain regions. Comparing tPCS with tDCS alone, we found that tPCS induced higher increase in power within the theta and alpha bandwidths.ConclusionThis study confirms that patients with CVP present abnormal EEG-indexed cortical activity compared with healthy controls. Moreover, we showed that combining two types of neurostimulation techniques had no effect, whereas the two interventions, when applied individually, have different neural signatures.

Effects of Transcranial Direct Current Stimulation, Transcranial Pulsed Current Stimulation, and Their Combination on Brain Oscillations in Patients with Chronic Visceral Pain: A Pilot Crossover Randomized Controlled Study.

Science.gov (United States)

Thibaut, Aurore; Russo, Cristina; Hurtado-Puerto, Aura Maria; Morales-Quezada, Jorge Leon; Deitos, Alícia; Petrozza, John Christopher; Freedman, Steven; Fregni, Felipe

2017-01-01

Chronic visceral pain (CVP) syndromes are persistently painful disorders with a remarkable lack of effective treatment options. This study aimed at evaluating the effects of different neuromodulation techniques in patients with CVP on cortical activity, through electreocephalography (EEG) and on pain perception, through clinical tests. A pilot crossover randomized controlled study. Out-patient. Adults with CVP (>3 months). Participants received four interventions in a randomized order: (1) transcranial pulsed current stimulation (tPCS) and active transcranial direct current stimulation (tDCS) combined, (2) tPCS alone, (3) tDCS alone, and (4) sham condition. Resting state quantitative electroencephalography (qEEG) and pain assessments were performed before and after each intervention. Results were compared with a cohort of 47 healthy controls. We enrolled six patients with CVP for a total of 21 visits completed. Compared with healthy participants, patients with CVP showed altered cortical activity characterized by increased power in theta, alpha and beta bands, and a significant reduction in the alpha/beta ratio. Regarding tES, the combination of tDCS with tPCS had no effect on power in any of the bandwidths, nor brain regions. Comparing tPCS with tDCS alone, we found that tPCS induced higher increase in power within the theta and alpha bandwidths. This study confirms that patients with CVP present abnormal EEG-indexed cortical activity compared with healthy controls. Moreover, we showed that combining two types of neurostimulation techniques had no effect, whereas the two interventions, when applied individually, have different neural signatures.

Pain perception in healthy volunteers

DEFF Research Database (Denmark)

Janum, Susanne; Nielsen, Signe Tellerup; Werner, Mads U

2016-01-01

We aimed to study the relationship between pain perception and cytokine release during systemic inflammation. We present a randomized crossover trial in healthy volunteers (n = 17) in 37 individual trials. Systemic inflammation was induced by an i.v. bolus of Escherichia coli LPS (2 ng/kg) on two...... separate trial days, with or without a nicotine patch applied 10 h previously. Pain perception at baseline, and 2 and 6 h after LPS was assessed by pressure algometry and tonic heat stimulation at an increasing temperature (45-48℃) during both trials. Compared with baseline, pain pressure threshold...... was reduced 2 and 6 h after LPS, while heat pain perception was accentuated at all testing temperatures after 2 but not 6 h. The magnitude of changes in pain perception did not correlate to cytokine release. No effect of transdermal nicotine or training status was observed. In conclusion, LPS administration...

What is the optimal anodal electrode position for inducing corticomotor excitability changes in transcranial direct current stimulation?

Science.gov (United States)

Lee, Minji; Kim, Yun-Hee; Im, Chang-Hwan; Kim, Jung-Hoon; Park, Chang-hyun; Chang, Won Hyuk; Lee, Ahee

2015-01-01

Transcranial direct current stimulation (tDCS) non-invasively modulates brain function by inducing neuronal excitability. The conventional hot spot for inducing the highest current density in the hand motor area may not be the optimal site for effective stimulation. In this study, we investigated the influence of the center position of the anodal electrode on changes in motor cortical excitability. We considered three tDCS conditions in 16 healthy subjects: (i) real stimulation with the anodal electrode located at the conventional hand motor hot spot determined by motor evoked potentials (MEPs); (ii) real stimulation with the anodal electrode located at the point with the highest current density in the hand motor area as determined by electric current simulation; and (iii) sham stimulation. Motor cortical excitability as measured by MEP amplitude increased after both real stimulation conditions, but not after sham stimulation. Stimulation using the simulation-derived anodal electrode position, which was found to be posterior to the MEP hot spot for all subjects, induced higher motor cortical excitability. Individual positioning of the anodal electrode, based on the consideration of anatomical differences between subjects, appears to be important for maximizing the effects of tDCS. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Analysis of eddy current induced in track on medium-low speed maglev train

Science.gov (United States)

Li, Guanchun; Jia, Zhen; He, Guang; Li, Jie

2017-06-01

Electromagnetic levitation (EMS) maglev train relies on the attraction between the electromagnets and rails which are mounted on the train to achieve suspension. During the movement, the magnetic field generated by the electromagnet will induce the eddy current in the orbit and the eddy current will weaken the suspended magnetic field. Which leads to the attenuation of the levitation force, the increases of suspension current and the degradation the suspension performance. In this paper, the influence of eddy current on the air gap magnetic field is solved by theoretical analysis, and the correction coefficient of air gap magnetic field is fitted according to the finite element data. The levitation force and current are calculated by the modified formula, and the velocity curves of the levitation force and current are obtained. The results show that the eddy current effect increases the load power by 61.9% in the case of heavy loads.

Suppressive and enhancing effects in early visual cortex during illusory shape perception: A comment on.

Science.gov (United States)

Moors, Pieter

2015-01-01

In a recent functional magnetic resonance imaging study, Kok and de Lange (2014) observed that BOLD activity for a Kanizsa illusory shape stimulus, in which pacmen-like inducers elicit an illusory shape percept, was either enhanced or suppressed relative to a nonillusory control configuration depending on whether the spatial profile of BOLD activity in early visual cortex was related to the illusory shape or the inducers, respectively. The authors argued that these findings fit well with the predictive coding framework, because top-down predictions related to the illusory shape are not met with bottom-up sensory input and hence the feedforward error signal is enhanced. Conversely, for the inducing elements, there is a match between top-down predictions and input, leading to a decrease in error. Rather than invoking predictive coding as the explanatory framework, the suppressive effect related to the inducers might be caused by neural adaptation to perceptually stable input due to the trial sequence used in the experiment.

Simulated Design Strategies for SPECT Collimators to Reduce the Eddy Currents Induced by MRI Gradient Fields

Science.gov (United States)

Samoudi, Amine M.; Van Audenhaege, Karen; Vermeeren, Günter; Verhoyen, Gregory; Martens, Luc; Van Holen, Roel; Joseph, Wout

2015-10-01

Combining single photon emission computed tomography (SPECT) with magnetic resonance imaging (MRI) requires the insertion of highly conductive SPECT collimators inside the MRI scanner, resulting in an induced eddy current disturbing the combined system. We reduced the eddy currents due to the insert of a novel tungsten collimator inside transverse and longitudinal gradient coils. The collimator was produced with metal additive manufacturing, that is part of a microSPECT insert for a preclinical SPECT/MRI scanner. We characterized the induced magnetic field due to the gradient field and adapted the collimators to reduce the induced eddy currents. We modeled the x-, y-, and z-gradient coil and the different collimator designs and simulated them with FEKO, a three-dimensional method of moments / finite element methods (MoM/FEM) full-wave simulation tool. We used a time analysis approach to generate the pulsed magnetic field gradient. Simulation results show that the maximum induced field can be reduced by 50.82% in the final design bringing the maximum induced magnetic field to less than 2% of the applied gradient for all the gradient coils. The numerical model was validated with measurements and was proposed as a tool for studying the effect of a SPECT collimator within the MRI gradient coils.

Current-induced changes of migration energy barriers in graphene and carbon nanotubes

Science.gov (United States)

Obodo, J. T.; Rungger, I.; Sanvito, S.; Schwingenschlögl, U.

2016-05-01

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. Electronic supplementary information (ESI) available. See DOI: 10.1039/C6NR00534A

Counterintuitive effects of global warming-induced wind patterns on primary production in the Northern Humboldt Current System.

Science.gov (United States)

Mogollón, Rodrigo; R Calil, Paulo H

2018-04-14

It has been hypothesized that global warming will strengthen upwelling-favorable winds in the Northern Humboldt Current System (NHCS) as a consequence of the increase of the land-sea thermal gradient along the Peruvian coast. The effect of strengthened winds in this region is assessed with the use of a coupled physical-biogeochemical model forced with projected and climatological winds. Strengthened winds induce an increase in primary production of 2% per latitudinal degree from 9.5°S to 5°S. In some important coastal upwelling sites primary production is reduced. This is due to a complex balance between nutrient availability, nutrient use efficiency, as well as eddy- and wind-driven factors. Mesoscale activity induces a net offshore transport of inorganic nutrients, thus reducing primary production in the coastal upwelling region. Wind mixing, in general disadvantageous for primary producers, leads to shorter residence times in the southern and central coastal zones. Overall, instead of a proportional enhancement in primary production due to increased winds, the NHCS becomes only 5% more productive (+5 mol C m -2 year -1 ), 10% less limited by nutrients and 15% less efficient due to eddy-driven effects. It is found that regions with a initial strong nutrient limitation are more efficient in terms of nutrient assimilation which makes them more resilient in face of the acceleration of the upwelling circulation. © 2018 John Wiley & Sons Ltd.

Theory of current-induced spin polarization in an electron gas

Science.gov (United States)

Gorini, Cosimo; Maleki Sheikhabadi, Amin; Shen, Ka; Tokatly, Ilya V.; Vignale, Giovanni; Raimondi, Roberto

2017-05-01

We derive the Bloch equations for the spin dynamics of a two-dimensional electron gas in the presence of spin-orbit coupling. For the latter we consider both the intrinsic mechanisms of structure inversion asymmetry (Rashba) and bulk inversion asymmetry (Dresselhaus), and the extrinsic ones arising from the scattering from impurities. The derivation is based on the SU(2) gauge-field formulation of the Rashba-Dresselhaus spin-orbit coupling. Our main result is the identification of a spin-generation torque arising from Elliot-Yafet scattering, which opposes a similar term arising from Dyakonov-Perel relaxation. Such a torque, which to the best of our knowledge has gone unnoticed so far, is of basic nature, i.e., should be effective whenever Elliott-Yafet processes are present in a system with intrinsic spin-orbit coupling, irrespective of further specific details. The spin-generation torque contributes to the current-induced spin polarization (CISP), also known as inverse spin-galvanic or Edelstein effect. As a result, the behavior of the CISP turns out to be more complex than one would surmise from consideration of the internal Rashba-Dresselhaus fields alone. In particular, the symmetry of the current-induced spin polarization does not necessarily coincide with that of the internal Rashba-Dresselhaus field, and an out-of-plane component of the CISP is generally predicted, as observed in recent experiments. We also discuss the extension to the three-dimensional electron gas, which may be relevant for the interpretation of experiments in thin films.

Identification of radiation induced dark current sources in pinned photodiode CMOS image sensors

International Nuclear Information System (INIS)

Goiffon, V.; Virmontois, C.; Magnan, P.; Cervantes, P.; Place, S.; Estribeau, M.; Martin-Gonthier, P.; Gaillardin, M.; Girard, S.; Paillet, P.

2012-01-01

This paper presents an investigation of Total Ionizing Dose (TID) induced dark current sources in Pinned Photodiodes (PPD) CMOS Image Sensors based on pixel design variations. The influence of several layout parameters is studied. Only one parameter is changed at a time enabling the direct evaluation of its contribution to the observed device degradation. By this approach, the origin of radiation induced dark current in PPD is localized on the pixel layout. The PPD peripheral shallow trench isolation does not seem to play a role in the degradation. The PPD area and a transfer gate contribution independent of the pixel dimensions appear to be the main sources of the TID induced dark current increase. This study also demonstrates that applying a negative voltage on the transfer gate during integration strongly reduces the radiation induced dark current. (authors)

Perception of linear horizontal self-motion induced by peripheral vision /linearvection/ - Basic characteristics and visual-vestibular interactions

Science.gov (United States)

Berthoz, A.; Pavard, B.; Young, L. R.

1975-01-01

The basic characteristics of the sensation of linear horizontal motion have been studied. Objective linear motion was induced by means of a moving cart. Visually induced linear motion perception (linearvection) was obtained by projection of moving images at the periphery of the visual field. Image velocity and luminance thresholds for the appearance of linearvection have been measured and are in the range of those for image motion detection (without sensation of self motion) by the visual system. Latencies of onset are around 1 sec and short term adaptation has been shown. The dynamic range of the visual analyzer as judged by frequency analysis is lower than the vestibular analyzer. Conflicting situations in which visual cues contradict vestibular and other proprioceptive cues show, in the case of linearvection a dominance of vision which supports the idea of an essential although not independent role of vision in self motion perception.

Strain-induced chiral magnetic effect in Weyl semimetals

International Nuclear Information System (INIS)

Cortijo, Alberto; Kharzeev, Dmitri; Vozmediano, Maria A. H.

2016-01-01

Here, we argue that strain applied to a time-reversal and inversion breaking Weyl semimetal in a magnetic field can induce an electric current via the chiral magnetic effect. A tight-binding model is used to show that strain generically changes the locations in the Brillouin zone but also the energies of the band touching points (tips of the Weyl cones). Since axial charge in a Weyl semimetal can relax via intervalley scattering processes, the induced current will decay with a time scale given by the lifetime of a chiral quasiparticle. Lastly, we estimate the strength and lifetime of the current for typical material parameters and find that it should be experimentally observable.

Vasotocin- and mesotocin-induced increases in short-circuit current across tree frog skin.

Science.gov (United States)

Takada, Makoto; Fujimaki-Aoba, Kayo; Hokari, Shigeru

2011-02-01

In adult amphibian skin, Na(+) crosses from outside to inside. This Na(+) transport can be measured as the amiloride-blockable short-circuit current (SCC) across the skin. We investigated the effects of arginine vasotocin (AVT) and mesotocin (MT), and those of antagonists of the vasopressin and oxytocin receptors, on the SCC across Hyla japonica skin. (1) Both AVT (100 pmol/L or more) and MT (1 nmol/L or more) increased the SCC. (2) The AVT- and MT-induced increases in SCC recovered with time (downregulation). (3) These AVT/MT-induced effects were blocked by application of OPC-31260 (vasopressin V(2)-receptor antagonist). (4) The OPC-31260 concentration needed to block the AVT-induced response was lower upon post-application (after application of agonist) than upon pre-application (before application of agonist), suggesting the number of receptors may have decreased after AVT application. (5) Upon repeated application of AVT (100 pmol/L), the induced SCC increase did not differ significantly between the 1st and 2nd applications. (6) The time to reach the half-maximum value of the AVT-induced or MT-induced increase in SCC was not significantly different between washout and post-application of OPC-31260, suggesting that post-application of OPC-31260 cleared AVT and MT from their receptors. The effects of AVT, MT, and their antagonists in H. japonica, which is adapted to a terrestrial habitat, are compared with our previously published data on Rana catesbeiana (=Lithobates catesbeianus), which is adapted to a semiaquatic habitat.

Influence of Joule heating on current-induced domain wall depinning

Energy Technology Data Exchange (ETDEWEB)

Moretti, Simone, E-mail: simone.moretti@usal.es; Raposo, Victor; Martinez, Eduardo [University of Salamanca, Plaza de los Caidos, 37008 Salamanca (Spain)

2016-06-07

The domain wall depinning from a notch in a Permalloy nanostrip on top of a SiO{sub 2}/Si substrate is studied theoretically under application of static magnetic fields and the injection of short current pulses. The influence of Joule heating on current-induced domain wall depinning is explored self-consistently by coupling the magnetization dynamics in the ferromagnetic strip to the heat transport throughout the system. Our results indicate that Joule heating plays a remarkable role in these processes, resulting in a reduction in the critical depinning field and/or in a temporary destruction of the ferromagnetic order for typically injected current pulses. In agreement with experimental observations, similar pinning-depinning phase diagrams can be deduced for both current polarities when the Joule heating is taken into account. These observations, which are incompatible with the sole contribution of spin transfer torques, provide a deeper understanding of the physics underlying these processes and establish the real scope of the spin transfer torque. They are also relevant for technological applications based on current-induced domain-wall motion along soft strips.

Probing wavenumbers of current-induced excitations in point-contact experiments

Directory of Open Access Journals (Sweden)

Z Wei

2010-06-01

Full Text Available Z Wei, M TsoiDepartment of Physics, Center for Nano and Molecular Science and Technology, and Texas Materials Institute, The University of Texas at Austin, Austin, TX, USAAbstract: We demonstrate how a mechanical point-contact technique can provide information on the wavenumber of spin waves excited by high-density electrical current in magnetic multilayers. By varying the size of point-contacts, we have been able to control the size of the excitation volume and therefore the wavelength of current-induced spin waves. This leads to a technique with in situ sensitivity to wavenumbers of current-induced excitations. Our detailed size-dependent measurements support the prediction that the excited wavelength is determined by the contact size.Keywords: spin transfer torque, giant magnetoresistance, spin waves, point contact

The minimizing style: perceptions of psychological abuse and quality of past and current relationships.

Science.gov (United States)

Varia, R; Abidin, R R

1999-11-01

The goals of this current project were to expand and elaborate on the results of Varia, Abidin, and Dass' (1996) study to better understand what historical parenting factors may contribute in creating a "Minimizing" perception of childhood psychological abuse. A second objective included examining the association between perceptual styles and adult ratings of adult relationship satisfaction. Ninety individuals from a non-clinical adult sample completed self-report questionnaires regarding psychological maltreatment and adult relationship satisfaction. Three groups were created and compared using analysis of variance. The groups were (I) "Non-Abused," consistent reporters of no abuse; (II) "Acknowledgers," consistent reporters of abuse; and (III) "Minimizers," reporters of abuse, but do not label themselves as having been abused. Results indicated a continuum effect with the Non-Abused individuals reporting the highest level of maternal warmth and affection, the Acknowledgers reporting the lowest, with the Minimizers in the middle. The Non-Abused group reported the healthiest adjustment in terms of adult relationship satisfaction. While Minimizers and Acknowledgers reported similar levels of psychologically abusive experiences, Acknowledgers reported more difficulties with adult relationships. This study highlights the importance of studying Minimizers, a group which describes abusive events but minimizes the meaning and scope of these experiences. The relatively higher levels of maternal care which the Minimizers reported is hypothesized to be associated with their perceptions that they were not abused and acted as a protective factor associated with better quality adult relationships. The varying degrees of nurturance and care in the early family environment of abused individuals is speculated to be associated with distinct perceptual styles.

Pharmacological modulation of cortical excitability shifts induced by transcranial direct current stimulation in humans.

Science.gov (United States)

Nitsche, M A; Fricke, K; Henschke, U; Schlitterlau, A; Liebetanz, D; Lang, N; Henning, S; Tergau, F; Paulus, W

2003-11-15

Transcranial direct current stimulation (tDCS) of the human motor cortex results in polarity-specific shifts of cortical excitability during and after stimulation. Anodal tDCS enhances and cathodal stimulation reduces excitability. Animal experiments have demonstrated that the effect of anodal tDCS is caused by neuronal depolarisation, while cathodal tDCS hyperpolarises cortical neurones. However, not much is known about the ion channels and receptors involved in these effects. Thus, the impact of the sodium channel blocker carbamazepine, the calcium channel blocker flunarizine and the NMDA receptor antagonist dextromethorphane on tDCS-elicited motor cortical excitability changes of healthy human subjects were tested. tDCS-protocols inducing excitability alterations (1) only during tDCS and (2) eliciting long-lasting after-effects were applied after drug administration. Carbamazepine selectively eliminated the excitability enhancement induced by anodal stimulation during and after tDCS. Flunarizine resulted in similar changes. Antagonising NMDA receptors did not alter current-generated excitability changes during a short stimulation, which elicits no after-effects, but prevented the induction of long-lasting after-effects independent of their direction. These results suggest that, like in other animals, cortical excitability shifts induced during tDCS in humans also depend on membrane polarisation, thus modulating the conductance of sodium and calcium channels. Moreover, they suggest that the after-effects may be NMDA receptor dependent. Since NMDA receptors are involved in neuroplastic changes, the results suggest a possible application of tDCS in the modulation or induction of these processes in a clinical setting. The selective elimination of tDCS-driven excitability enhancements by carbamazepine proposes a role for this drug in focussing the effects of cathodal tDCS, which may have important future clinical applications.

Asymmetric magnetoimpedance in amorphous microwires due to bias current: Effect of torsional stress

International Nuclear Information System (INIS)

Buznikov, N.A.; Antonov, A.S.; Granovsky, A.B.

2014-01-01

The influence of torsional stress on the asymmetric magnetoimpedance in a glass-coated negative magnetostrictive amorphous microwire due to bias current is studied theoretically. The longitudinal and off-diagonal impedance components are found assuming a simplified spatial distribution of the magnetoelastic anisotropy induced by the torsional stress. The asymmetry in the field dependence of the impedance components is attributed to the combination of the circular magnetic field produced by the bias current and a helical anisotropy induced by the torsional stress. The asymmetry in the magnetoimpedance and the low-field hysteresis are analyzed as a function of the bias current and torsional stress. It is shown that the application of torsional stress significantly changes the value of the bias current required to suppress the hysteresis effect. The results obtained may be useful for applications in magnetic-field and stress sensors. - Highlights: • Effects of torsional stress on magnetoimpedance in amorphous microwire are studied. • Asymmetry in magnetoimpedance is analyzed as a function of bias current and stress. • Torsional stress changes the anisotropy and effects on the microwire impedance. • Field-dependence of impedance is anhysteretic when bias current exceeds threshold value. • Threshold bias current can be tuned by the application of torsional stress

Asymmetric magnetoimpedance in amorphous microwires due to bias current: Effect of torsional stress

Energy Technology Data Exchange (ETDEWEB)

Buznikov, N.A., E-mail: n_buznikov@mail.ru [Scientific-Research Institute of Natural Gases and Gas Technologies – GAZPROM VNIIGAZ, Razvilka, Leninsky District, Moscow Region 142717 (Russian Federation); Antonov, A.S. [Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Granovsky, A.B. [Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation)

2014-04-15

The influence of torsional stress on the asymmetric magnetoimpedance in a glass-coated negative magnetostrictive amorphous microwire due to bias current is studied theoretically. The longitudinal and off-diagonal impedance components are found assuming a simplified spatial distribution of the magnetoelastic anisotropy induced by the torsional stress. The asymmetry in the field dependence of the impedance components is attributed to the combination of the circular magnetic field produced by the bias current and a helical anisotropy induced by the torsional stress. The asymmetry in the magnetoimpedance and the low-field hysteresis are analyzed as a function of the bias current and torsional stress. It is shown that the application of torsional stress significantly changes the value of the bias current required to suppress the hysteresis effect. The results obtained may be useful for applications in magnetic-field and stress sensors. - Highlights: • Effects of torsional stress on magnetoimpedance in amorphous microwire are studied. • Asymmetry in magnetoimpedance is analyzed as a function of bias current and stress. • Torsional stress changes the anisotropy and effects on the microwire impedance. • Field-dependence of impedance is anhysteretic when bias current exceeds threshold value. • Threshold bias current can be tuned by the application of torsional stress.

Effective Instructor Feedback: Perceptions of Online Graduate Students

Directory of Open Access Journals (Sweden)

Beverley Getzlaf

2009-07-01

Full Text Available This descriptive study explored online graduate students' perceptions of effective instructor feedback. The objectives of the study were to determine the students’ perceptions of the content of effective instructor feedback (“what should be included in effective feedback?” and the process of effective instructor feedback (“how should effective feedback be provided?”. The participants were students completing health-related graduate courses offered exclusively online. Data were collected via a survey that included open ended questions inviting participants to share their perspectives regarding effective online instructor feedback. Thematic analysis revealed five major themes: student involvement/individualization, gentle guidance, being positively constructive, timeliness and future orientation. We conclude that effective instructor feedback has positive outcomes for the students. Future studies are warranted to investigate strategies to make feedback a mutual process between instructor and student that supports an effective feedback cycle.

Colossal X-Ray-Induced Persistent Photoconductivity in Current-Perpendicular-to-Plane Ferroelectric/Semiconductor Junctions

KAUST Repository

Hu, Weijin

2017-12-07

Persistent photoconductivity (PPC) is an intriguing physical phenomenon, where electric conduction is retained after the termination of electromagnetic radiation, which makes it appealing for applications in a wide range of optoelectronic devices. So far, PPC has been observed in bulk materials and thin-film structures, where the current flows in the plane, limiting the magnitude of the effect. Here using epitaxial Nb:SrTiO3/Sm0.1Bi0.9FeO3/Pt junctions with a current-perpendicular-to-plane geometry, a colossal X-ray-induced PPC (XPPC) is achieved with a magnitude of six orders. This PPC persists for days with negligible decay. Furthermore, the pristine insulating state could be fully recovered by thermal annealing for a few minutes. Based on the electric transport and microstructure analysis, this colossal XPPC effect is attributed to the X-ray-induced formation and ionization of oxygen vacancies, which drives nonvolatile modification of atomic configurations and results in the reduction of interfacial Schottky barriers. This mechanism differs from the conventional mechanism of photon-enhanced carrier density/mobility in the current-in-plane structures. With their persistent nature, such ferroelectric/semiconductor heterojunctions open a new route toward X-ray sensing and imaging applications.

The study of human bodies' impedance networks in testing leakage currents of electrical equipments

Science.gov (United States)

Zhang, Zhaohui; Wang, Xiaofei

2006-11-01

In the testing of electrical equipments' leakage currents, impedance networks of human bodies are used to simulate the current's effect on human bodies, and they are key to the preciseness of the testing result. This paper analyses and calculates three human bodies' impedance networks of measuring electric burn current, perception or reaction current, let-go current in IEC60990, by using Matlab, compares the research result of current effect thresholds' change with sine wave's frequency published in IEC479-2, and amends parameters of measuring networks. It also analyses the change of perception or reaction current with waveform by Multisim.

Odors Bias Time Perception in Visual and Auditory Modalities.

Science.gov (United States)

Yue, Zhenzhu; Gao, Tianyu; Chen, Lihan; Wu, Jiashuang

2016-01-01

Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal) were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor). The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a framework of

The Temporal Effect of Training Utility Perceptions on Adopting a Trained Method: The Role of Perceived Organizational Support

Science.gov (United States)

Madera, Juan M.; Steele, Stacey T.; Beier, Margaret

2011-01-01

The current study examined the temporal effect of perceived training utility on adoption of a trained method and how perceived organizational support influences the relationship between perceived training utility perceptions and adoption of a trained method. With the use of a correlational-survey-based design, this longitudinal study required…

Prevalence, Harm Perceptions, and Reasons for Using Noncombustible Tobacco Products Among Current and Former Smokers

Science.gov (United States)

Pearson, Jennifer; Xiao, Haijun; Stalgaitis, Carolyn; Vallone, Donna

2014-01-01

Objectives. We provided estimates of noncombustible tobacco product (electronic nicotine delivery systems [ENDS]; snus; chewing tobacco, dip, or snuff; and dissolvables) use among current and former smokers and examined harm perceptions of noncombustible tobacco products and reasons for their use. Methods. We assessed awareness of, prevalence of, purchase of, harm perceptions of, and reasons for using noncombustible tobacco products among 1487 current and former smokers from 8 US designated market areas. We used adjusted logistic regression to identify correlates of noncombustible tobacco product use. Results. Of the sample, 96% were aware of at least 1 noncombustible tobacco product, but only 33% had used and 21% had purchased one. Noncombustible tobacco product use was associated with being male, non-Hispanic White, younger, and more nicotine dependent. Respondents used noncombustible tobacco products to cut down or quit cigarettes, but only snus was associated with a higher likelihood of making a quit attempt. Users of noncombustible tobacco products, particularly ENDS, were most likely to endorse the product as less harmful than cigarettes. Conclusions. Smokers may use noncombustible tobacco products to cut down or quit smoking. However, noncombustible tobacco product use was not associated with a reduction in cigarettes per day or cessation. PMID:24922154

Photocurrent, Rectification, and Magnetic Field Symmetry of Induced Current Through Quantum Dots

DEFF Research Database (Denmark)

DiCarlo, L.; M. Marcus, C.; Harris jr, J.

2003-01-01

We report mesoscopic dc current generation in an open chaotic quantum dot with ac excitation applied to one of the shape-defining gates. For excitation frequencies large compared to the inverse dwell time of electrons in the dot (i.e., GHz), we find mesoscopic fluctuations of induced current...... that are fully asymmetric in the applied perpendicular magnetic field, as predicted by recent theory. Conductance, measured simultaneously, is found to be symmetric in field. In the adiabatic (i.e., MHz) regime, in contrast, the induced current is always symmetric in field, suggesting its origin is mesoscopic...

The Effects of Transcranial Direct Current Stimulation (tDCS on Psychomotor and Visual Perception Functions Related to Driving Skills

Directory of Open Access Journals (Sweden)

Alexander Brunnauer

2018-01-01

Full Text Available Objective: It could be demonstrated that anodal transcranial direct current stimulation (tDCS of the left dorsolateral prefrontal cortex (DLPFC enhances accuracy in working memory tasks and reaction time in healthy adults and thus may also have an influence on complex everyday tasks like driving a car. However, no studies have applied tDCS to psychomotor skills related to a standard driving test so far.Methods: 10 female and 5 male healthy adults without any medication and history of psychiatric or neurological illness were randomly assigned to two groups receiving active and sham stimulation in a double blind, cross-over study design. Standardized computerized psychomotor tests according to the German guidelines for road and traffic safety were administered at baseline. Then they performed the same tests during an anodal or sham tDCS of the left DLPFC in two separated sessions.Results: No significant improvements in skills related to driving performance like visual perception, stress tolerance, concentration, and vigilance could be shown after left anodal prefrontal tDCS. Side effects were low and did not differ between active and sham stimulation.Conclusions: The findings of our study indicate that left prefrontal tDCS may not alter driving skills affording more automated action patterns but as shown in previous studies may have an influence on driving behavior requiring executive control processes. This however has to be proved in future studies and within greater samples.

Current-induced changes of migration energy barriers in graphene and carbon nanotubes.

Science.gov (United States)

Obodo, J T; Rungger, I; Sanvito, S; Schwingenschlögl, U

2016-05-21

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.

Expertise effects in cutaneous wind perception

NARCIS (Netherlands)

Pluijms, Joost P.; Cañal-Bruland, Rouwen; Bergmann Tiest, Wouter M.; Mulder, F.A.; Savelsbergh, Geert J.P.

2015-01-01

We examined whether expertise effects are present in cutaneous wind perception. To this end, we presented wind stimuli consisting of different wind directions and speeds in a wind simulator. The wind simulator generated wind stimuli from 16 directions and with three speeds by means of eight

Cigarette Design Features: Effects on Emission Levels, User Perception, and Behavior.

Science.gov (United States)

Talhout, Reinskje; Richter, Patricia A; Stepanov, Irina; Watson, Christina V; Watson, Clifford H

2018-01-01

This paper describes the effects of non-tobacco, physical cigarette design features on smoke emissions, product appeal, and smoking behaviors - 3 factors that determine smoker's exposure and related health risks. We reviewed available evidence for the impact of filter ventilation, new filter types, and cigarettes dimensions on toxic emissions, smoker's perceptions, and behavior. For evidence sources we used scientific literature and websites providing product characteristics and marketing information. Whereas filter ventilation results in lower machine-generated emissions, it also leads to perceptions of lighter taste and relative safety in smokers who can unwittingly employ more intense smoking behavior to obtain the desired amount of nicotine and sensory appeal. Filter additives that modify smoke emissions can also modify sensory cues, resulting in changes in smoking behavior. Flavor capsules increase the cigarette's appeal and novelty, and lead to misperceptions of reduced harm. Slim cigarettes have lower yields of some smoke emissions, but smoking behavior can be more intense than with standard cigarettes. Physical design features significantly impact machine-measured emission yields in cigarette smoke, product appeal, smoking behaviors, and exposures in smokers. The influence of current and emerging design features is important in understanding the effectiveness of regulatory actions to reduce smoking-related harm.

Novel magnetic wire fabrication process by way of nanoimprint lithography for current induced magnetization switching

Science.gov (United States)

Asari, Tsukasa; Shibata, Ryosuke; Awano, Hiroyuki

2017-05-01

Nanoimprint lithography (NIL) is an effective method to fabricate nanowire because it does not need expensive systems and this process is easier than conventional processes. In this letter, we report the Current Induced Magnetization Switching (CIMS) in perpendicularly magnetized Tb-Co alloy nanowire fabricated by NIL. The CIMS in Tb-Co alloy wire was observed by using current pulse under in-plane external magnetic field (HL). We successfully observed the CIMS in Tb-Co wire fabricated by NIL. Additionally, we found that the critical current density (Jc) for the CIMS in the Tb-Co wire fabricated by NIL is 4 times smaller than that fabricated by conventional lift-off process under HL = 200Oe. These results indicate that the NIL is effective method for the CIMS.

Teachers' perceptions of effective science, technology, and mathematics professional development and changes in classroom practices

Science.gov (United States)

Boriack, Anna Christine

The purpose of this study is to examine teachers' perceptions of professional development and changes in classroom practice. A proposed conceptual framework for effective professional development that results in changes in classroom practices was developed. Data from two programs that provided professional development to teachers in the areas of technology, mathematics, and science was used to inform the conceptual framework. These two programs were Target Technology in Texas (T3) and Mathematics, Science, and Technology Teacher Preparation Academies (MSTTPA). This dissertation used a multiple article format to explore each program separately, yet the proposed conceptual framework allowed for comparisons to be made between the two programs. The first study investigated teachers' perceptions of technology-related professional development after their districts had received a T3 grant. An online survey was administrated to all teachers to determine their perceptions of technology-related professional development along with technology self-efficacy. Classroom observations were conducted to determine if teachers were implementing technology. The results indicated that teachers did not perceive professional development as being effective and were not implementing technology in their classrooms. Teachers did have high technology self-efficacy and perceived adequate school support, which implies that effective professional development may be a large factor in whether or not teachers implement technology in their classrooms. The second study evaluated participants' perceptions of the effectiveness of mathematics and science professional development offered through a MSTTP academy. Current and former participants completed an online survey which measured their perceptions of academy activities and school environment. Participants also self-reported classroom implementation of technology. Interviews and open-ended survey questions were used to provide further insight into

Ghanaian parents' perceptions of pre and postnatal nutrient supplements and their effects.

Science.gov (United States)

Adams, Katherine P; Okronipa, Harriet; Adu-Afarwuah, Seth; Arimond, Mary; Kumordzie, Sika; Oaks, Brietta M; Ocansey, Maku E; Young, Rebecca R; Vosti, Stephen A; Dewey, Kathryn G

2018-04-15

Small-quantity lipid-based nutrient supplements (SQ-LNS) have been studied in efficacy and effectiveness trials, but little is known about how parents perceive the products and their effects. In a randomised trial in Ghana, efficacy of SQ-LNS provided to women during pregnancy and the first 6 months postpartum and to their children from 6 to 18 months of age was assessed by comparison with iron-folic acid (IFA) capsules and multiple micronutrient (MMN) capsules provided to women. In a follow-up study conducted when the index children from the original trial were between 4 and 6 years of age, we used survey-based methods to assess retrospective and current parental perceptions of nutrient supplements generally and of SQ-LNS and their effects compared with perceptions IFA and MMN capsules. Most parents perceived that the assigned supplements (SQ-LNS, IFA, or MMN) positively impacted the mother during pregnancy (approximately 89% of both mothers and fathers) and during lactation (84% of mothers and 86% of fathers). Almost all (≥90%) of mothers and fathers perceived that the assigned supplement positively impacted the index child and expected continued positive impacts on the child's health and human capital into the future. A smaller percentage of parents perceived negative impacts of the supplements (7%-17% of mothers and 4%-12% of fathers). Perceptions of positive impacts and of negative impacts did not differ by intervention group. The results suggest that similar populations would likely be receptive to programs to deliver SQ-LNS or micronutrient capsules. © 2018 The Authors. Maternal and Child Nutrition Published by John Wiley & Sons, Ltd.

Spin Current Noise of the Spin Seebeck Effect and Spin Pumping

Science.gov (United States)

Matsuo, M.; Ohnuma, Y.; Kato, T.; Maekawa, S.

2018-01-01

We theoretically investigate the fluctuation of a pure spin current induced by the spin Seebeck effect and spin pumping in a normal-metal-(NM-)ferromagnet(FM) bilayer system. Starting with a simple ferromagnet-insulator-(FI-)NM interface model with both spin-conserving and non-spin-conserving processes, we derive general expressions of the spin current and the spin-current noise at the interface within second-order perturbation of the FI-NM coupling strength, and estimate them for a yttrium-iron-garnet-platinum interface. We show that the spin-current noise can be used to determine the effective spin carried by a magnon modified by the non-spin-conserving process at the interface. In addition, we show that it provides information on the effective spin of a magnon, heating at the interface under spin pumping, and spin Hall angle of the NM.

Training Stiffness perception: Knowledge of results and modality effects

Directory of Open Access Journals (Sweden)

Korman Maria

2011-12-01

Full Text Available Perception of compliant objects demands integration of haptic and visual position information with force information. Multisensory interactions are ubiquitous in perception, even at early processing stages, and thus can potentially play a role in learning. In this study we explored humans' improvement on uni-sensory stiffness discrimination as a function of different sensory conditions and immediate knowledge of results (KR during training. Two by two design was used: subjects were trained over two days on stiffness discrimination task with either matched visual-tactile, or tactile only stimuli and either with or without immediate feedback on their performance during training trials. Training resulted in both immediate but also latent, overnight learning in the proportion of correctly discriminated pairs of targets (PC, in all groups. Discrimination decision time (DT gains were obtained only during practice, while between sessions partial deterioration was evident. Affordance of visual information during training blocks resulted in higher PC during training blocks, but lower PC in the haptic-only retests. This finding challenges the notion that long-term unisensory learning mechanisms operate optimally under multisensory training conditions, at least for the combination of the visual and haptic modalities. We didn’t find evidence that information feedback during training enhances discrimination ability in terms of PC. However, we found transient within-session effects of KR and visual-haptic trainings on DT: while visualhaptic training resulted in slower responses, KR training induced faster responses.

Quantitative Sensory Testing and Current Perception Threshold Testing in Patients With Chronic Pain Following Lower Extremity Fracture.

Science.gov (United States)

Griffioen, Mari A; Greenspan, Joel D; Johantgen, Meg; Von Rueden, Kathryn; O'Toole, Robert V; Dorsey, Susan G; Renn, Cynthia L

2018-01-01

Chronic pain is a significant problem for patients with lower extremity injuries. While pain hypersensitivity has been identified in many chronic pain conditions, it is not known whether patients with chronic pain following lower extremity fracture report pain hypersensitivity in the injured leg. To quantify and compare peripheral somatosensory function and sensory nerve activation thresholds in persons with chronic pain following lower extremity fractures with a cohort of persons with no history of lower extremity fractures. This was a cross-sectional study where quantitative sensory testing and current perception threshold testing were conducted on the injured and noninjured legs of cases and both legs of controls. A total of 14 cases and 28 controls participated in the study. Mean time since injury at the time of testing for cases was 22.3 (standard deviation = 12.1) months. The warmth detection threshold ( p = .024) and nerve activation thresholds at 2,000 Hz ( p sensory nerve function at the site of injury in patients with chronic pain following lower extremity fractures using quantitative sensory testing and current perception threshold testing.

Relationship between leadership styles of hospital pharmacists and perceptions of work-unit effectiveness.

Science.gov (United States)

Bennett, C R; Grussing, P G; Hutchinson, R A; Stewart, J E

1988-08-01

Relationships between hospital pharmacists' perceptions of their own and their immediate supervisors' leadership styles and their perceptions of the effectiveness of their work units were examined. Pharmacists practicing in 12 large Chicago-area hospitals were asked to complete a four-part questionnaire that consisted of demographic questions, the LEADSelf instrument, the LEADOther instrument, and a measure of perceived work unit effectiveness. Respondents' primary, secondary, and combination leadership styles and their degree of style adaptability were determined and compared with the primary, secondary, and combination leadership styles and style adaptability of their immediate supervisors and with their perceptions of the effectiveness of their work units. Pharmacists involved in providing clinical or drug information services and pharmacists responsible for purchasing activities perceived their work units to be most and least effective, respectively. Most respondents perceived their primary leadership style to be high task-high relationship, but only 32% perceived their immediate supervisors to exhibit this style. Pharmacists who perceived their immediate supervisors to have high relationship leadership styles (based on primary and combination style classifications) had significantly more favorable perceptions of the effectiveness of their work units than did pharmacists who perceived their supervisors to exhibit low relationship styles. Respondents' perceptions of their supervisors' style adaptability were positively and significantly correlated with their perceptions of work-unit effectiveness. Respondents who thought their supervisors' leadership styles were more adaptable than their own had the most favorable perceptions of work-unit effectiveness.(ABSTRACT TRUNCATED AT 250 WORDS)

Ragweed-induced allergic rhinoconjunctivitis: current and emerging treatment options

Directory of Open Access Journals (Sweden)

Ihler F

2015-02-01

Full Text Available Friedrich Ihler, Martin CanisDepartment of Otorhinolaryngology, University Medical Center Göttingen, Göttingen, GermanyAbstract: Ragweed (Ambrosia spp. is an annually flowering plant whose pollen bears high allergenic potential. Ragweed-induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population. The invasive occurrence of ragweed (A. artemisiifolia poses an increasing challenge to public health in Europe and Asia as well. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds. Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed-induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed-induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists. The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy. An approach targeting toll-like receptor 9 by

Change in magnetic induction lines during the current-induced destruction of superconductivity

Energy Technology Data Exchange (ETDEWEB)

Makiei, B; Golab, S; Sikora, A; Troinar, E; Zacharko, W [Polska Akademia Nauk, Wroclaw. Instytut Niskich Temperatur i Badan Strukturalnych

1976-09-01

Recent results of experimental investigations show that during the current-induced destruction of superconductivity in cylindrical samples a non-azimuthal component of the magnetic induction arises. This 'autoparamagnetic effect' is observable both in type I and type II superconductors. Assuming a helical form for the magnetic flux filaments the angle between the magnetic induction lines and the plane perpendicular to the Pb + In alloy sample axis is estimated in several cases. A conceptual explanation of the energy losses in the resistive state is.

Chemotherapy-Induced Constipation and Diarrhea: Pathophysiology, Current and Emerging Treatments

Science.gov (United States)

McQuade, Rachel M.; Stojanovska, Vanesa; Abalo, Raquel; Bornstein, Joel C.; Nurgali, Kulmira

2016-01-01

Gastrointestinal (GI) side-effects of chemotherapy are a debilitating and often overlooked clinical hurdle in cancer management. Chemotherapy-induced constipation (CIC) and Diarrhea (CID) present a constant challenge in the efficient and tolerable treatment of cancer and are amongst the primary contributors to dose reductions, delays and cessation of treatment. Although prevalence of CIC is hard to estimate, it is believed to affect approximately 16% of cancer patients, whilst incidence of CID has been estimated to be as high as 80%. Despite this, the underlying mechanisms of both CID and CIC remain unclear, but are believed to result from a combination of intersecting mechanisms including inflammation, secretory dysfunctions, GI dysmotility and alterations in GI innervation. Current treatments for CIC and CID aim to reduce the severity of symptoms rather than combating the pathophysiological mechanisms of dysfunction, and often result in worsening of already chronic GI symptoms or trigger the onset of a plethora of other side-effects including respiratory depression, uneven heartbeat, seizures, and neurotoxicity. Emerging treatments including those targeting the enteric nervous system present promising avenues to alleviate CID and CIC. Identification of potential targets for novel therapies to alleviate chemotherapy-induced toxicity is essential to improve clinical outcomes and quality of life amongst cancer sufferers. PMID:27857691

Current-induced changes of migration energy barriers in graphene and carbon nanotubes

KAUST Repository

Obodo, Tobechukwu Joshua

2016-04-29

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. © 2016 The Royal Society of Chemistry.

Gigantic 2D laser-induced photovoltaic effect in magnetically doped topological insulators for surface zero-bias spin-polarized current generation

Science.gov (United States)

Shikin, A. M.; Voroshin, V. Yu; Rybkin, A. G.; Kokh, K. A.; Tereshchenko, O. E.; Ishida, Y.; Kimura, A.

2018-01-01

A new kind of 2D photovoltaic effect (PVE) with the generation of anomalously large surface photovoltage up to 210 meV in magnetically doped topological insulators (TIs) has been studied by the laser time-resolved pump-probe angle-resolved photoelectron spectroscopy. The PVE has maximal efficiency for TIs with high occupation of the upper Dirac cone (DC) states and the Dirac point located inside the fundamental energy gap. For TIs with low occupation of the upper DC states and the Dirac point located inside the valence band the generated surface photovoltage is significantly reduced. We have shown that the observed giant PVE is related to the laser-generated electron-hole asymmetry followed by accumulation of the photoexcited electrons at the surface. It is accompanied by the 2D relaxation process with the generation of zero-bias spin-polarized currents flowing along the topological surface states (TSSs) outside the laser beam spot. As a result, the spin-polarized current generates an effective in-plane magnetic field that is experimentally confirmed by the k II-shift of the DC relative to the bottom non-spin-polarized conduction band states. The realized 2D PVE can be considered as a source for the generation of zero-bias surface spin-polarized currents and the laser-induced local surface magnetization developed in such kind 2D TSS materials.

Origin of current-induced forces in an atomic gold wire: A first-principles study

DEFF Research Database (Denmark)

Brandbyge, Mads; Stokbro, Kurt; Taylor, Jeremy Philip

2003-01-01

We address the microscopic origin of the current-induced forces by analyzing results of first principles density functional calculations of atomic gold wires connected to two gold electrodes with different electrochemical potentials. We find that current induced forces are closely related...

High dislocation density of tin induced by electric current

International Nuclear Information System (INIS)

Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung; Wu, Albert T.

2015-01-01

A dislocation density of as high as 10 17 /m 2 in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10 3 A/ cm 2 . The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining

Modifiable risk factors of ecstasy use: risk perception, current dependence, perceived control, and depression

Science.gov (United States)

Leung, Kit Sang; Ben Abdallah, Arbi; Cottler, Linda B.

2009-01-01

Risk perception, perceived behavioral control of obtaining ecstasy (PBC-obtaining), current ecstasy dependence, and recent depression have been associated with past ecstasy use, however, their utility in predicting ecstasy use has not been demonstrated. This study aimed to determine whether these four modifiable risk factors could predict ecstasy use after controlling for socio-demographic covariates and recent polydrug use. Data from 601 ecstasy users in the National Institute on Drug Abuse funded TriCity Study of Club Drug Use, Abuse and Dependence were analyzed using multivariate logistic regression. Participants were interviewed twice within a 2-week period using standardized instruments. Thirteen percent (n=80) of the participants reported using ecstasy between the two interviews. Low risk perception, high PBC-obtaining (an estimated ecstasy procurement time ecstasy dependence were statistically associated with ecstasy use between the two interviews. Recent depression was not a significant predictor. Despite not being a target predictor, recent polydrug use was also statistically associated with ecstasy use. The present findings may inform the development of interventions targeting ecstasy users. PMID:19880258

Higher cortical modulation of pain perception in the human brain: Psychological determinant.

Science.gov (United States)

Chen, Andrew Cn

2009-10-01

Pain perception and its genesis in the human brain have been reviewed recently. In the current article, the reports on pain modulation in the human brain were reviewed from higher cortical regulation, i.e. top-down effect, particularly studied in psychological determinants. Pain modulation can be examined by gene therapy, physical modulation, pharmacological modulation, psychological modulation, and pathophysiological modulation. In psychological modulation, this article examined (a) willed determination, (b) distraction, (c) placebo, (d) hypnosis, (e) meditation, (f) qi-gong, (g) belief, and (h) emotions, respectively, in the brain function for pain modulation. In each, the operational definition, cortical processing, neuroimaging, and pain modulation were systematically deliberated. However, not all studies had featured the brain modulation processing but rather demonstrated potential effects on human pain. In our own studies on the emotional modulation on human pain, we observed that emotions could be induced from music melodies or pictures perception for reduction of tonic human pain, mainly in potentiation of the posterior alpha EEG fields, likely resulted from underneath activities of precuneous in regulation of consciousness, including pain perception. To sum, higher brain functions become the leading edge research in all sciences. How to solve the information bit of thinking and feeling in the brain can be the greatest challenge of human intelligence. Application of higher cortical modulation of human pain and suffering can lead to the progress of social humanity and civilization.

Current-ripple effect on superconductive dc critical current measurements

International Nuclear Information System (INIS)

Goodrich, L.F.; Bray, S.L.; Clark, A.F.

1988-01-01

The effect of sample-current power-supply ripple on dc critical current measurement in multifilamentary NbTi superconductors was evaluated. In general the ripple in a current supply became more significant above 500 A because effective filtering was hard to achieve. Ripple also caused noise at the input of the voltmeter used for the measurements. The quantitative effect of current ripple was studied using a battery current supply modified to allow the creation of ripple current with variable frequency and amplitude. Problems common to all large-conductor critical current measurements are discussed

Short-term pre- and post-operative stress prolongs incision-induced pain hypersensitivity without changing basal pain perception.

Science.gov (United States)

Cao, Jing; Wang, Po-Kai; Tiwari, Vinod; Liang, Lingli; Lutz, Brianna Marie; Shieh, Kun-Ruey; Zang, Wei-Dong; Kaufman, Andrew G; Bekker, Alex; Gao, Xiao-Qun; Tao, Yuan-Xiang

2015-12-02

Chronic stress has been reported to increase basal pain sensitivity and/or exacerbate existing persistent pain. However, most surgical patients have normal physiological and psychological health status such as normal pain perception before surgery although they do experience short-term stress during pre- and post-operative periods. Whether or not this short-term stress affects persistent postsurgical pain is unclear. In this study, we showed that pre- or post-surgical exposure to immobilization 6 h daily for three consecutive days did not change basal responses to mechanical, thermal, or cold stimuli or peak levels of incision-induced hypersensitivity to these stimuli; however, immobilization did prolong the duration of incision-induced hypersensitivity in both male and female rats. These phenomena were also observed in post-surgical exposure to forced swimming 25 min daily for 3 consecutive days. Short-term stress induced by immobilization was demonstrated by an elevation in the level of serum corticosterone, an increase in swim immobility, and a decrease in sucrose consumption. Blocking this short-term stress via intrathecal administration of a selective glucocorticoid receptor antagonist, RU38486, or bilateral adrenalectomy significantly attenuated the prolongation of incision-induced hypersensitivity to mechanical, thermal, and cold stimuli. Our results indicate that short-term stress during the pre- or post-operative period delays postoperative pain recovery although it does not affect basal pain perception. Prevention of short-term stress may facilitate patients' recovery from postoperative pain.

Current reprogramming systems in regenerative medicine: from somatic cells to induced pluripotent stem cells.

Science.gov (United States)

Hu, Chenxia; Li, Lanjuan

2016-01-01

Induced pluripotent stem cells (iPSCs) paved the way for research fields including cell therapy, drug screening, disease modeling and the mechanism of embryonic development. Although iPSC technology has been improved by various delivery systems, direct transduction and small molecule regulation, low reprogramming efficiency and genomic modification steps still inhibit its clinical use. Improvements in current vectors and the exploration of novel vectors are required to balance efficiency and genomic modification for reprogramming. Herein, we set out a comprehensive analysis of current reprogramming systems for the generation of iPSCs from somatic cells. By clarifying advantages and disadvantages of the current reprogramming systems, we are striding toward an effective route to generate clinical grade iPSCs.

Mental Imagery Induces Cross-Modal Sensory Plasticity and Changes Future Auditory Perception.

Science.gov (United States)

Berger, Christopher C; Ehrsson, H Henrik

2018-04-01

Can what we imagine in our minds change how we perceive the world in the future? A continuous process of multisensory integration and recalibration is responsible for maintaining a correspondence between the senses (e.g., vision, touch, audition) and, ultimately, a stable and coherent perception of our environment. This process depends on the plasticity of our sensory systems. The so-called ventriloquism aftereffect-a shift in the perceived localization of sounds presented alone after repeated exposure to spatially mismatched auditory and visual stimuli-is a clear example of this type of plasticity in the audiovisual domain. In a series of six studies with 24 participants each, we investigated an imagery-induced ventriloquism aftereffect in which imagining a visual stimulus elicits the same frequency-specific auditory aftereffect as actually seeing one. These results demonstrate that mental imagery can recalibrate the senses and induce the same cross-modal sensory plasticity as real sensory stimuli.

Energy confinement of tokamak plasma with consideration of bootstrap current effect

International Nuclear Information System (INIS)

Yuan Ying; Gao Qingdi

1992-01-01

Based on the η i -mode induced anomalous transport model of Lee et al., the energy confinement of tokamak plasmas with auxiliary heating is investigated with consideration of bootstrap current effect. The results indicate that energy confinement time increases with plasma current and tokamak major radius, and decreases with heating power, toroidal field and minor radius. This is in reasonable agreement with the Kaye-Goldston empirical scaling law. Bootstrap current always leads to an improvement of energy confinement and the contraction of inversion radius. When γ, the ratio between bootstrap current and total plasma current, is small, the part of energy confinement time contributed from bootstrap current will be about γ/2

Novel magnetic wire fabrication process by way of nanoimprint lithography for current induced magnetization switching

Directory of Open Access Journals (Sweden)

Tsukasa Asari

2017-05-01

Full Text Available Nanoimprint lithography (NIL is an effective method to fabricate nanowire because it does not need expensive systems and this process is easier than conventional processes. In this letter, we report the Current Induced Magnetization Switching (CIMS in perpendicularly magnetized Tb-Co alloy nanowire fabricated by NIL. The CIMS in Tb-Co alloy wire was observed by using current pulse under in-plane external magnetic field (HL. We successfully observed the CIMS in Tb-Co wire fabricated by NIL. Additionally, we found that the critical current density (Jc for the CIMS in the Tb-Co wire fabricated by NIL is 4 times smaller than that fabricated by conventional lift-off process under HL = 200Oe. These results indicate that the NIL is effective method for the CIMS.

Effect of Induced Magnetic Field on MHD Mixed Convection Flow in Vertical Microchannel

Science.gov (United States)

Jha, B. K.; Aina, B.

2017-08-01

The present work presents a theoretical investigation of an MHD mixed convection flow in a vertical microchannel formed by two electrically non-conducting infinite vertical parallel plates. The influence of an induced magnetic field arising due to motion of an electrically conducting fluid is taken into consideration. The governing equations of the motion are a set of simultaneous ordinary differential equations and their exact solutions in dimensionless form have been obtained for the velocity field, the induced magnetic field and the temperature field. The expressions for the induced current density and skin friction have also been obtained. The effects of various non-dimensional parameters such as rarefaction, fluid wall interaction, the Hartmann number and the magnetic Prandtl number on the velocity, the induced magnetic field, the temperature, the induced current density, and skin friction have been presented in a graphical form. It is found that the effect of the Hartmann number and magnetic Prandtl number on the induced current density is found to have a decreasing nature at the central region of the microchannel.

PLC-dependent intracellular Ca2+ release was associated with C6-ceramide-induced inhibition of Na+ current in rat granule cells.

Science.gov (United States)

Liu, Zheng; Fei, Xiao-Wei; Fang, Yan-Jia; Shi, Wen-Jie; Zhang, Yu-Qiu; Mei, Yan-Ai

2008-09-01

In this report, the effects of C(6)-ceramide on the voltage-gated inward Na(+) currents (I(Na)), two types of main K(+) current [outward rectifier delayed K(+) current (I(K)) and outward transient K(+) current (I(A))], and cell death in cultured rat cerebellar granule cells were investigated. At concentrations of 0.01-100 microM, ceramide produced a dose-dependent and reversible inhibition of I(Na) without alteration of the steady-state activation and inactivation properties. Treatment with C(2)-ceramide caused a similar inhibitory effect on I(Na). However, dihydro-C(6)-ceramide failed to modulate I(Na). The effect of C(6)-ceramide on I(Na) was abolished by intracellular infusion of the Ca(2+)-chelating agent, 1,2-bis (2-aminophenoxy) ethane-N, N, N9, N9-tetraacetic acid, but was mimicked by application of caffeine. Blocking the release of Ca(2+) from the sarcoplasmic reticulum with ryanodine receptor blocker induced a gradual increase in I(Na) amplitude and eliminated the effect of ceramide on I(Na). In contrast, the blocker of the inositol 1,4,5-trisphosphate-sensitive Ca(2+) receptor did not affect the action of C(6)-ceramide. Intracellular application of GTPgammaS also induced a gradual decrease in I(Na) amplitude, while GDPbetaS eliminated the effect of C(6)-ceramide on I(Na). Furthermore, the C(6)-ceramide effect on I(Na) was abolished after application of the phospholipase C (PLC) blockers and was greatly reduced by the calmodulin inhibitors. Fluorescence staining showed that C(6)-ceramide decreased cell viability and blocking I(Na) by tetrodotoxin did not mimic the effect of C(6)-ceramide, and inhibiting intracellular Ca(2+) release by dantrolene could not decrease the C(6)-ceramide-induced cell death. We therefore suggest that increased PLC-dependent Ca(2+) release through the ryanodine-sensitive Ca(2+) receptor may be responsible for the C(6)-ceramide-induced inhibition of I(Na), which does not seem to be associated with C(6)-ceramide-induced granule

Decreased pain perception by unconscious emotional pictures

Directory of Open Access Journals (Sweden)

Irene Peláez

2016-10-01

Full Text Available Pain perception arises from a complex interaction between a nociceptive stimulus and different emotional and cognitive factors, which appear to be mediated by both automatic and controlled systems. Previous evidence has shown that whereas conscious processing of unpleasant stimuli enhances pain perception, emotional influences on pain under unaware conditions are much less known. The aim of the present study was to investigate the modulation of pain perception by unconscious emotional pictures through an emotional masking paradigm. Two kinds of both somatosensory (painful and non-painful and emotional stimulation (negative and neutral pictures were employed. Fifty pain-free participants were asked to rate the perception of pain they were feeling in response to laser-induced somatosensory stimuli as faster as they can. Data from pain intensity and reaction times were measured. Statistical analyses revealed a significant effect for the interaction between pain and emotional stimulation, but surprisingly this relationship was opposite to expected. In particular, lower pain intensity scores and longer reaction times were found in response to negative images being strengthened this effect for painful stimulation. Present findings suggest a clear pain perception modulation by unconscious emotional contexts. Attentional capture mechanisms triggered by unaware negative stimulation could explain this phenomenon leading to a withdrawal of processing resources from pain.

Farmers' perception on the effects of climate change on groundnut ...

African Journals Online (AJOL)

The study analyzed farmer's perception on the effect of climate change on groundnut production in Obi Local Government Area of Benue State, Nigeria. Despite the fact that efforts have been made towards combating climate change, research and policies directed towards understanding of local perception are useful in ...

Effects of coloured lighting on the perception of interior spaces.

Science.gov (United States)

Odabaşioğlu, Seden; Olguntürk, Nіlgün

2015-02-01

Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.

Change in magnetic induction lines during the current-induced destruction of superconductivity

Energy Technology Data Exchange (ETDEWEB)

Makiej, B; Golab, S; Sikora, A; Trojnar, E; Zacharko, W

1976-09-01

Recent results of experimental investigations show that during the current-induced destruction of superconductivity in cylindrical samples a non-azimuthal component of the magnetic induction arises. This ''autoparamagnetic effect'' is observable both in type I and type II superconductors. Assuming a helical form for the magnetic flux filaments the angle between the magnetic induction lines and the plane perpendicular to the Pb + In alloy sample axis is estimated in several cases. A conceptual explanation of the energy losses in the resistive state is presented. 4 refs.

Current and Future Leaders' Perceptions of Agricultural Biotechnology

Science.gov (United States)

Wingenbach, Gary J.; Miller, Rene P.

2009-01-01

Were elected state FFA officers' attitudes toward agricultural biotechnology significantly different from elected Texas legislators' attitudes about the same topic? The purpose of this study was to determine if differences existed in agricultural biotechnology perceptions or information source preferences when compared by leadership status:…

Neutral current induced neutrino oscillations in a supernova

CERN Document Server

Kusenko, A; Kusenko, Alexander; Segre, Gino

1997-01-01

Neutral currents induced matter oscillations of electroweak-active (anti-)neutrinos to sterile neutrinos can explain the observed motion of pulsars. In contrast to a recently proposed explanation of the pulsar birth velocities based on the electron to tau (muon) neutrino oscillations [hep-ph/9606428], the heaviest neutrino (either active or sterile) would have to have mass of order several keV.

Racial/ethnic differences in electronic cigarette knowledge, social norms, and risk perceptions among current and former smokers.

Science.gov (United States)

Webb Hooper, Monica; Kolar, Stephanie K

2017-04-01

Psychosocial factors that may affect electronic cigarette (e-cigarette) initiation or maintenance among racial/ethnic minorities are not well-understood. This study examined racial/ethnic differences in e-cigarette knowledge, risk perceptions, and social norms among current and former smokers. Individuals with a tobacco smoking history and an awareness of e-cigarettes (N=285) were recruited from the community from June to August 2014. Telephone-administered surveys assessed demographics, smoking status, and e-cigarette knowledge, risk perceptions, and normative beliefs. Analyses of covariance and multinomial logistic regression tested associations by race/ethnicity. Controlling for sociodemographics and smoking status, White participants scored significantly higher on e-cigarette knowledge, compared to both Hispanics and African Americans/Blacks. Knowledge was lower among African Americans/Blacks compared to Hispanics. Compared to both Whites and Hispanics, African American/Black participants held lower perceptions regarding e-cigarette health risks and were less likely to view e-cigarettes as addictive. Normative beliefs did not differ by race/ethnicity. In conclusion, e-cigarette knowledge, health risk perceptions, and perceived addictiveness differed by race/ethnicity. The variation in e-cigarette knowledge and beliefs among smokers and former smokers has implications for use, and potentially, dual use. Understanding these relationships in unrepresented populations can inform future research and practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adaptive threshold hunting for the effects of transcranial direct current stimulation on primary motor cortex inhibition.

Science.gov (United States)

Mooney, Ronan A; Cirillo, John; Byblow, Winston D

2018-06-01

Primary motor cortex excitability can be modulated by anodal and cathodal transcranial direct current stimulation (tDCS). These neuromodulatory effects may, in part, be dependent on modulation within gamma-aminobutyric acid (GABA)-mediated inhibitory networks. GABAergic function can be quantified non-invasively using adaptive threshold hunting paired-pulse transcranial magnetic stimulation (TMS). The previous studies have used TMS with posterior-anterior (PA) induced current to assess tDCS effects on inhibition. However, TMS with anterior-posterior (AP) induced current in the brain provides a more robust measure of GABA-mediated inhibition. The aim of the present study was to assess the modulation of corticomotor excitability and inhibition after anodal and cathodal tDCS using TMS with PA- and AP-induced current. In 16 young adults (26 ± 1 years), we investigated the response to anodal, cathodal, and sham tDCS in a repeated-measures double-blinded crossover design. Adaptive threshold hunting paired-pulse TMS with PA- and AP-induced current was used to examine separate interneuronal populations within M1 and their influence on corticomotor excitability and short- and long-interval inhibition (SICI and LICI) for up to 60 min after tDCS. Unexpectedly, cathodal tDCS increased corticomotor excitability assessed with AP (P = 0.047) but not PA stimulation (P = 0.74). SICI AP was reduced after anodal tDCS compared with sham (P = 0.040). Pearson's correlations indicated that SICI AP and LICI AP modulation was associated with corticomotor excitability after anodal (P = 0.027) and cathodal tDCS (P = 0.042). The after-effects of tDCS on corticomotor excitability may depend on the direction of the TMS-induced current used to make assessments, and on modulation within GABA-mediated inhibitory circuits.

Mental Health Service Providers: College Student Perceptions of Helper Effectiveness

Science.gov (United States)

Ackerman, Ashley M.; Wantz, Richard A.; Firmin, Michael W; Poindexter, Dawn C.; Pujara, Amita L.

2014-01-01

Undergraduate perceptions of the overall effectiveness of six types of mental health service providers (MHSPs) were obtained with a survey. Although many mental health services are available to consumers in the United States, research has indicated that these services are underutilized. Perceptions have been linked to therapeutic outcomes and may…

Solution of magnetic field and eddy current problem induced by rotating magnetic poles (abstract)

Science.gov (United States)

Liu, Z. J.; Low, T. S.

1996-04-01

The magnetic field and eddy current problems induced by rotating permanent magnet poles occur in electromagnetic dampers, magnetic couplings, and many other devices. Whereas numerical techniques, for example, finite element methods can be exploited to study various features of these problems, such as heat generation and drag torque development, etc., the analytical solution is always of interest to the designers since it helps them to gain the insight into the interdependence of the parameters involved and provides an efficient tool for designing. Some of the previous work showed that the solution of the eddy current problem due to the linearly moving magnet poles can give satisfactory approximation for the eddy current problem due to rotating fields. However, in many practical cases, especially when the number of magnet poles is small, there is significant effect of flux focusing due to the geometry. The above approximation can therefore lead to marked errors in the theoretical predictions of the device performance. Bernot et al. recently described an analytical solution in a polar coordinate system where the radial field is excited by a time-varying source. A discussion of an analytical solution of the magnetic field and eddy current problems induced by moving magnet poles in radial field machines will be given in this article. The theoretical predictions obtained from this method is compared with the results obtained from finite element calculations. The validity of the method is also checked by the comparison of the theoretical predictions and the measurements from a test machine. It is shown that the introduced solution leads to a significant improvement in the air gap field prediction as compared with the results obtained from the analytical solution that models the eddy current problems induced by linearly moving magnet poles.

Side Effect Perceptions and Their Impact on Treatment Decisions in Women.

Science.gov (United States)

Waters, Erika A; Pachur, Thorsten; Colditz, Graham A

2017-04-01

Side effects prompt some patients to forego otherwise-beneficial therapies. This study explored which characteristics make side effects particularly aversive. We used a psychometric approach, originating from research on risk perception, to identify the factors (or components) underlying side effect perceptions. Women ( N = 149) aged 40 to 74 years were recruited from a patient registry to complete an online experiment. Participants were presented with hypothetical scenarios in which an effective and necessary medication conferred a small risk of a single side effect (e.g., nausea, dizziness). They rated a broad range of side effects on several characteristics (e.g., embarrassing, treatable). In addition, we collected 4 measures of aversiveness for each side effect: choosing to take the medication, willingness to pay to avoid the side effect (WTP), negative affective attitude associated with the side effect, and how each side effect ranks among others in terms of undesirability. A principal components analysis (PCA) was used to identify the components underlying side effect perceptions. Then, for each aversiveness measure separately, regression analyses were used to determine which components predicted differences in aversiveness among the side effects. The PCA revealed 4 components underlying side effect perceptions: affective challenge (e.g., frightening), social challenge (e.g., disfiguring), physical challenge (e.g., painful), and familiarity (e.g., common). Side effects perceived as affectively and physically challenging elicited the highest levels of aversiveness across all 4 measures. Understanding what side effect characteristics are most aversive may inform interventions to improve medical decisions and facilitate the translation of novel biomedical therapies into clinical practice.

Current-induced energy barrier suppression for electromigration from first principles

KAUST Repository

Zhang, Ruoxing; Rungger, Ivan; Sanvito, Stefano; Hou, Shimin

2011-01-01

We present an efficient method for evaluating current-induced forces in nanoscale junctions, which naturally integrates into the nonequilibrium Green's function formalism implemented within density functional theory. This allows us to perform

Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol.

Science.gov (United States)

Gillick, Bernadette; Menk, Jeremiah; Mueller, Bryon; Meekins, Gregg; Krach, Linda E; Feyma, Timothy; Rudser, Kyle

2015-11-12

Perinatal stroke occurs in more than 1 in 2,500 live births and resultant congenital hemiparesis necessitates investigation into interventions which may improve long-term function and decreased burden of care beyond current therapies ( http://www.cdc.gov/ncbddd/cp/data.html ). Constraint-Induced Movement Therapy (CIMT) is recognized as an effective hemiparesis rehabilitation intervention. Transcranial direct current stimulation as an adjunct treatment to CIMT may potentiate neuroplastic responses and improve motor function. The methodology of a clinical trial in children designed as a placebo-controlled, serial -session, non-invasive brain stimulation trial incorporating CIMT is described here. The primary hypotheses are 1) that no serious adverse events will occur in children receiving non-invasive brain stimulation and 2) that children in the stimulation intervention group will show significant improvements in hand motor function compared to children in the placebo stimulation control group. A randomized, controlled, double-blinded clinical trial. Twenty children and/or young adults (ages 8-21) with congenital hemiparesis, will be enrolled. The intervention group will receive ten 2-hour sessions of transcranial direct current stimulation combined with constraint-induced movement therapy and the control group will receive sham stimulation with CIMT. The primary outcome measure is safety assessment of transcranial direct current stimulation by physician evaluation, vital sign monitoring and symptom reports. Additionally, hand function will be evaluated using the Assisting Hand Assessment, grip strength and assessment of goals using the Canadian Occupational Performance Measure. Neuroimaging will confirm diagnoses, corticospinal tract integrity and cortical activation. Motor cortical excitability will also be examined using transcranial magnetic stimulation techniques. Combining non-invasive brain stimulation and CIMT interventions has the potential to improve motor

GABA concentration in superior temporal sulcus predicts gamma power and perception in the sound-induced flash illusion.

Science.gov (United States)

Balz, Johanna; Keil, Julian; Roa Romero, Yadira; Mekle, Ralf; Schubert, Florian; Aydin, Semiha; Ittermann, Bernd; Gallinat, Jürgen; Senkowski, Daniel

2016-01-15

In everyday life we are confronted with inputs of multisensory stimuli that need to be integrated across our senses. Individuals vary considerably in how they integrate multisensory information, yet the neurochemical foundations underlying this variability are not well understood. Neural oscillations, especially in the gamma band (>30Hz) play an important role in multisensory processing. Furthermore, gamma-aminobutyric acid (GABA) neurotransmission contributes to the generation of gamma band oscillations (GBO), which can be sustained by activation of metabotropic glutamate receptors. Hence, differences in the GABA and glutamate systems might contribute to individual differences in multisensory processing. In this combined magnetic resonance spectroscopy and electroencephalography study, we examined the relationships between GABA and glutamate concentrations in the superior temporal sulcus (STS), source localized GBO, and illusion rate in the sound-induced flash illusion (SIFI). In 39 human volunteers we found robust relationships between GABA concentration, GBO power, and the SIFI perception rate (r-values=0.44 to 0.53). The correlation between GBO power and SIFI perception rate was about twofold higher when the modulating influence of the GABA level was included in the analysis as compared to when it was excluded. No significant effects were obtained for glutamate concentration. Our study suggests that the GABA level shapes individual differences in audiovisual perception through its modulating influence on GBO. GABA neurotransmission could be a promising target for treatment interventions of multisensory processing deficits in clinical populations, such as schizophrenia or autism. Copyright © 2015 Elsevier Inc. All rights reserved.

Leadership effectiveness in Higher Education: Managerial self-perceptions versus perceptions of others

Directory of Open Access Journals (Sweden)

Tessie H.H. Herbst

2011-03-01

Research purpose: The purpose of this study was to investigate the prevalence of selfperception accuracy amongst the managers and to explore the patterns of interaction between self-perception accuracy (regarding their leadership behaviour and perceived transformational leadership behaviour (as measured by composite ‘other’-ratings. Motivation of the study: Research has shown that managers in various work environments typically overestimate their own level of competence and that this could impact on the effectiveness of their leadership behaviour. This phenomenon has however not yet been researched in the context of South African higher education institutions. Research design, approach and method: A quantitative cross-sectional study of the relationship between self-perception accuracy and leadership effectiveness was conducted amongst the total population (N = 204 of staff members in management positions. The response rate was 67% and the realised sample consisted of 137 managers. Leadership behaviour was measured by means of behavioural ratings on the following five dimensions of the Leadership Practices Inventory (LPI: ‘Challenging the process’, ‘Inspiring a shared vision’, ‘Enabling others to act’, ‘Modelling the way’ and ‘Encouraging the heart’. Main findings: Statistically significant discrepancies were found between self- and observer ratings on all five leadership dimensions, indicating a probable overestimation of their own capabilities. Results further provide evidence that perceived leadership effectiveness on three of the five transformational leadership practices varied as a function of the self-perceptions of managers. Practical/managerial implications: Managerial development practices should sensitise managers to what is essentially introspective and provide opportunities for them to reflect upon and question their leadership practices. Contribution/value-add: A challenge for higher education is to embark on feedback intensive

The Relationship among EFL Teachers’ Critical Thinking, Self-efficacy, and their Perception of Effective Teaching

Directory of Open Access Journals (Sweden)

Nassim Shangarffam

2010-05-01

Full Text Available The present study was an attempt, in the first place, to observe whether there was any significant relationship among teachers’ critical thinking, self-efficacy, and perception of effective teaching. Moreover, the researchers tried to examine which variable was a better predictor of perception of effective teaching. To this end, the measures of the critical thinking ability of 143 EFL teachers were obtained using Honey’s (2000 Critical Thinking Questionnaire(adopted from Naieni, 2005. Also, their sense of efficacy was estimated utilizing Tschannen-Moran and Hoy’s (2001 Teachers’ Sense of Efficacy Scale. Moreover, their perception of effective teaching was determined employing Bell’s (2005 Effective Teaching Questionnaire. The results revealed a statistically significant relationship between both critical thinking and self efficacy of teachers and their perception of effective teaching. However, only two of the components of critical thinking, namely analysis and evaluation, were correlated with perception of effective teaching. Also, critical thinking components had a significant relationship with perception of effective teaching components. Additionally, it was found that there was a positive relationship between all components of self efficacy and perception of effective teaching and its components. Finally, the regression analysis showed that self efficacy was a better predictor of teachers’ perception of effective teaching in comparison with critical thinking though the margin of difference was not that large. This study has implications for the EFL teacher preparation and education programs.

MEASUREMENTS AND MODELING OF EDDY CURRENT EFFECTS IN BNL'S AGS BOOSTER

International Nuclear Information System (INIS)

BROWN, K.A.; AHRENS, L.; GARDNER, C.; GLENN, J.W.; HARVEY, M.; MENG, W.; ZENO, K.

2006-01-01

Recent beam experiments at BNL's AGS Booster have enabled us to study in more detail the effects of eddy currents on the lattice structure and our control over the betatron tune. The Booster is capable of operating at ramp rates as high as 9 T/sec. At these ramp rates eddy currents in the vacuum chambers significantly alter the fields and gradients seen by the beam as it is accelerated. The Booster was designed with these effects in mind and to help control the field uniformity and linearity in the Booster Dipoles special vacuum chambers were designed with current windings to negate the affect of the induced eddy currents. In this report results from betatron tune measurements and eddy current simulations will be presented. We will then present results from modeling the accelerator using the results of the magnetic field simulations and compare these to the measurements

New pathway for the formation of metallic cubic phase Ge-Sb-Te compounds induced by an electric current.

Science.gov (United States)

Park, Yong-Jin; Cho, Ju-Young; Jeong, Min-Woo; Na, Sekwon; Joo, Young-Chang

2016-02-23

The novel discovery of a current-induced transition from insulator to metal in the crystalline phase of Ge2Sb2Te5 and GeSb4Te7 have been studied by means of a model using line-patterned samples. The resistivity of cubic phase Ge-Sb-Te compound was reduced by an electrical current (~1 MA/cm(2)), and the final resistivity was determined based on the stress current density, regardless of the initial resistivity and temperature, which indicates that the conductivity of Ge-Sb-Te compound can be modulated by an electrical current. The minimum resistivity of Ge-Sb-Te materials can be achieved at high kinetic rates by applying an electrical current, and the material properties change from insulating to metallic behavior without a phase transition. The current-induced metal transition is more effective in GeSb4Te7 than Ge2Sb2Te5, which depends on the intrinsic vacancy of materials. Electromigration, which is the migration of atoms induced by a momentum transfer from charge carriers, can easily promote the rearrangement of vacancies in the cubic phase of Ge-Sb-Te compound. This behavior differs significantly from thermal annealing, which accompanies a phase transition to the hexagonal phase. This result suggests a new pathway for modulating the electrical conductivity and material properties of chalcogenide materials by applying an electrical current.

Measurement of the current in water discharge using magneto-optical Faraday effect

International Nuclear Information System (INIS)

Sarkisov, G.S.; Woodworth, J.R.

2006-01-01

The observation of magnetooptical Faraday effects in water in experiments with electrical breakdown is presented. After high-voltage breakdown, the ionized channel with ∼4 kA current was generated. The magnetic field from the current channel induces a circular birefringence which results in rotation of the polarization plane of a probing laser (200 ps, 532 nm). In spite of fast opposite radius drop of the magnetic field in radial direction, the Faraday rotation effect drops very slowly. The rotation of the polarization plane was ∼0.65 deg. ±5%. The optical measurements are in good agreement within ∼7% with the electrical measurements of the current

Strain-assisted current-induced magnetization reversal in magnetic tunnel junctions: A micromagnetic study with phase-field microelasticity

International Nuclear Information System (INIS)

Huang, H. B.; Hu, J. M.; Yang, T. N.; Chen, L. Q.; Ma, X. Q.

2014-01-01

Effect of substrate misfit strain on current-induced in-plane magnetization reversal in CoFeB-MgO based magnetic tunnel junctions is investigated by combining micromagnetic simulations with phase-field microelasticity theory. It is found that the critical current density for in-plane magnetization reversal decreases dramatically with an increasing substrate strain, since the effective elastic field can drag the magnetization to one of the four in-plane diagonal directions. A potential strain-assisted multilevel bit spin transfer magnetization switching device using substrate misfit strain is also proposed.

Effects of tetrodotoxin and ion replacements on the short-circuit current induced by Escherichiacoli heat stable enterotoxin across small intestine of the gerbil (Gerbillus cheesmani

Directory of Open Access Journals (Sweden)

Fawzia Yaqoub Al-Balool

2004-03-01

Full Text Available The effects of mucosally added Escherichia coli heat stable enterotoxin (STa 30 ng ml-1 on the basal short-circuit current (Isc in µA cm-2 across stripped and unstripped sheets of jejuna and ilea taken from fed, starved (4 days, water ad lib and undernourished (50% control food intake for 21 days gerbil (Gerbillus cheesmani were investigated. The effect of neurotoxin tetrodotoxin (TTX 10 µM and the effects of replacing chloride by gluconate or the effects of removing bicarbonate from bathing buffers on the maximum increase in Isc induced by STa were also investigated. The maximum increase in Isc which resulted from the addition of STa were significantly higher in jejuna and ilea taken from starved and undernourished gerbils when compared with the fed control both using stripped and unstripped sheets. In the two regions of the small intestine taken from fed and starved animals TTX reduced the maximum increase in Isc induced by STa across unstripped sheets only. Moreover in jejuna and ilea taken from undernourished gerbils TTX reduced significantly the maximum increase in Isc induced by STa across stripped and unstripped sheets. Replacing chloride by gluconate decreased the maximum increase in Isc induced by STa across jejuna and ilea taken from undernourished gerbils only. Removing bicarbonates from bathing buffer decreased the maximum increase in Isc across the jejuna and ilea taken from starved and undernourished gerbils.

Crossmodal influences on visual perception

Science.gov (United States)

Shams, Ladan; Kim, Robyn

2010-09-01

Vision is generally considered the dominant sensory modality; self-contained and independent of other senses. In this article, we will present recent results that contradict this view, and show that visual perception can be strongly altered by sound and touch, and such alterations can occur even at early stages of processing, as early as primary visual cortex. We will first review the behavioral evidence demonstrating modulation of visual perception by other modalities. As extreme examples of such modulations, we will describe two visual illusions induced by sound, and a visual illusion induced by touch. Next, we will discuss studies demonstrating modulation of activity in visual areas by stimulation of other modalities, and discuss possible pathways that could underpin such interactions. This will be followed by a discussion of how crossmodal interactions can affect visual learning and adaptation. We will review several studies showing crossmodal effects on visual learning. We will conclude with a discussion of computational principles governing these crossmodal interactions, and review several recent studies that demonstrate that these interactions are statistically optimal.

Odors bias time perception in visual and auditory modalities

Directory of Open Access Journals (Sweden)

Zhenzhu eYue

2016-04-01

Full Text Available Previous studies have shown that emotional states alter our perception of time. However, attention, which is modulated by a number of factors, such as emotional events, also influences time perception. To exclude potential attentional effects associated with emotional events, various types of odors (inducing different levels of emotional arousal were used to explore whether olfactory events modulated time perception differently in visual and auditory modalities. Participants were shown either a visual dot or heard a continuous tone for 1000 ms or 4000 ms while they were exposed to odors of jasmine, lavender, or garlic. Participants then reproduced the temporal durations of the preceding visual or auditory stimuli by pressing the spacebar twice. Their reproduced durations were compared to those in the control condition (without odor. The results showed that participants produced significantly longer time intervals in the lavender condition than in the jasmine or garlic conditions. The overall influence of odor on time perception was equivalent for both visual and auditory modalities. The analysis of the interaction effect showed that participants produced longer durations than the actual duration in the short interval condition, but they produced shorter durations in the long interval condition. The effect sizes were larger for the auditory modality than those for the visual modality. Moreover, by comparing performance across the initial and the final blocks of the experiment, we found odor adaptation effects were mainly manifested as longer reproductions for the short time interval later in the adaptation phase, and there was a larger effect size in the auditory modality. In summary, the present results indicate that odors imposed differential impacts on reproduced time durations, and they were constrained by different sensory modalities, valence of the emotional events, and target durations. Biases in time perception could be accounted for by a

Mutual influence between current-induced giant magnetoresistance and radiation-induced magnetoresistance oscillations in the GaAs/AlGaAs 2DES.

Science.gov (United States)

Samaraweera, R L; Liu, H-C; Wang, Z; Reichl, C; Wegscheider, W; Mani, R G

2017-07-11

Radiation-induced magnetoresistance oscillations are examined in the GaAs/AlGaAs 2D system in the regime where an observed concurrent giant magnetoresistance is systematically varied with a supplementary dc-current, I dc . The I dc tuned giant magnetoresistance is subsequently separated from the photo-excited oscillatory resistance using a multi-conduction model in order to examine the interplay between the two effects. The results show that the invoked multiconduction model describes the observed giant magnetoresistance effect even in the presence of radiation-induced magnetoresistance oscillations, the magnetoresistance oscillations do not modify the giant magnetoresistance, and the magnetoresistance oscillatory extrema, i.e., maxima and minima, disappear rather asymmetrically with increasing I dc . The results suggest the interpretation that the I dc serves to suppress scattering between states near the Fermi level in a strong magnetic field limit.

Effects of electrode size and spacing on sensory modalities in the phantom thumb perception area for the forearm amputees.

Science.gov (United States)

Li, P; Chai, G H; Zhu, K H; Lan, N; Sui, X H

2015-01-01

Tactile sensory feedback plays a key role in accomplishing the dexterous manipulation of prosthetic hands for the amputees, and the non-invasive transcutaneous electrical nerve stimulation (TENS) of the phantom finger perception (PFP) area would be an effective way to realize sensory feedback clinically. In order to realize the high-spatial-resolution tactile sensory feedback in the PFP region, we investigated the effects of electrode size and spacing on the tactile sensations for potentially optimizing the surface electrode array configuration. Six forearm-amputated subjects were recruited in the psychophysical studies. With the diameter of the circular electrode increasing from 3 mm to 12 mm, the threshold current intensity was enhanced correspondingly under different sensory modalities. The smaller electrode could potentially lead to high sensation spatial resolution. Whereas, the smaller the electrode, the less the number of sensory modalities. For an Φ-3 mm electrode, it is even hard for the subject to perceive any perception modalities under normal stimulating current. In addition, the two-electrode discrimination distance (TEDD) in the phantom thumb perception area decreased with electrode size decreasing in two directions of parallel or perpendicular to the forearm. No significant difference of TEDD existed along the two directions. Studies in this paper would guide the configuration optimization of the TENS electrode array for potential high spatial-resolution sensory feedback.

Transcranial Alternating Current Stimulation Attenuates Neuronal Adaptation.

Science.gov (United States)

Kar, Kohitij; Duijnhouwer, Jacob; Krekelberg, Bart

2017-03-01

We previously showed that brief application of 2 mA (peak-to-peak) transcranial currents alternating at 10 Hz significantly reduces motion adaptation in humans. This is but one of many behavioral studies showing that weak currents applied to the scalp modulate neural processing. Transcranial stimulation has been shown to improve perception, learning, and a range of clinical symptoms. Few studies, however, have measured the neural consequences of transcranial current stimulation. We capitalized on the strong link between motion perception and neural activity in the middle temporal (MT) area of the macaque monkey to study the neural mechanisms that underlie the behavioral consequences of transcranial alternating current stimulation. First, we observed that 2 mA currents generated substantial intracranial fields, which were much stronger in the stimulated hemisphere (0.12 V/m) than on the opposite side of the brain (0.03 V/m). Second, we found that brief application of transcranial alternating current stimulation at 10 Hz reduced spike-frequency adaptation of MT neurons and led to a broadband increase in the power spectrum of local field potentials. Together, these findings provide a direct demonstration that weak electric fields applied to the scalp significantly affect neural processing in the primate brain and that this includes a hitherto unknown mechanism that attenuates sensory adaptation. SIGNIFICANCE STATEMENT Transcranial stimulation has been claimed to improve perception, learning, and a range of clinical symptoms. Little is known, however, how transcranial current stimulation generates such effects, and the search for better stimulation protocols proceeds largely by trial and error. We investigated, for the first time, the neural consequences of stimulation in the monkey brain. We found that even brief application of alternating current stimulation reduced the effects of adaptation on single-neuron firing rates and local field potentials; this mechanistic

Moderating effect of nurses' customer-oriented perception between organizational citizenship behaviors and satisfaction.

Science.gov (United States)

Chang, Ching Sheng; Chang, Hae Ching

2010-08-01

This study investigates whether organizational citizenship behaviors enhance job satisfaction among nursing personnel, while exploring whether customer-oriented perception has a moderating effect between nursing personnel's organizational citizenship behaviors and job satisfaction.The authors used a cross-sectional survey sent to 500 nurses with 232 valid responses. According to the research findings, nurses' organizational citizenship behaviors have a positive and significant influence on job satisfaction. Results also indicated that the moderating effect of nurses' customer-oriented perception on the relationship between their organizational citizenship behaviors and job satisfaction was stronger for high customer-oriented perception than it was low customer-oriented perception.

Trickle-down effects of supervisor perceptions of interactional justice: a moderated mediation approach.

Science.gov (United States)

Ambrose, Maureen L; Schminke, Marshall; Mayer, David M

2013-07-01

Supervisors' perceptions of how fairly they are treated by their own supervisors can influence their subordinates' perceptions, attitudes, and behavior. We present a moderated mediation model that demonstrates how work group structure can enhance or constrain these effects. Results show supervisors' perceptions of the fairness of the interactional treatment they receive relate to their subordinates' perceptions of interactional justice climate, and this relationship is stronger in work groups with more organic structures. Furthermore, consistent with the moderated mediation prediction, interactional justice climate mediates the relationship between supervisors' perceptions of interactional justice and outcomes when work group structures are more organic. We discuss the implications of the findings for research on justice and trickle-down effects. PsycINFO Database Record (c) 2013 APA, all rights reserved.

A framework for the first-person internal sensation of visual perception in mammals and a comparable circuitry for olfactory perception in Drosophila.

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Vadakkan, Kunjumon I

2015-01-01

Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure

THE RELATION OF FREQUENCY TO THE PHYSIOLOGICAL EFFECTS OF ULTRA-HIGH FREQUENCY CURRENTS.

Science.gov (United States)

Christie, R V; Loomis, A L

1929-01-31

1. Biological effects of electromagnetic waves emitted by a vacuum tube oscillator have been studied at frequencis ranging from 8,300,000 to 158,000,000 cycles per second (1.9 to 38 meters wave-length). 2. The effects produced on animals can be fully explained on the basis of the heat generated by high frequency currents which are induced in them. 3. No evidence was obtained to support the theory that certain wave-lengths have a specific action on living cells. 4. At frequencies below 50,000,000 cycles, the effect of these radiations on animals is proportionate to the intensity of the electro-magnetic field. As the frequency is increased beyond this point, the amount of induced current is diminished and the apparent lethality of the radiation is decreased. This can be explained by changes occurring in the dielectric properties of tissues at low wave-lengths.

The Effects of General System Justification on Corruption Perception and Intent.

Science.gov (United States)

Tan, Xuyun; Liu, Li; Huang, Zhenwei; Zheng, Wenwen; Liang, Yuan

2016-01-01

Previous research stresses that system justifying belief can weaken corruption perception, by this possibly fostering unjust behaviors. However, general results of the effect of general system justification on corruption are ambiguous, indicating also a lessening impact. We conducted a line of studies trying to elucidate these circumstances by testing the effect of general system justification on corruption perception and intention. In addition, we explored institutional trust as a possible mediator in this process. For this purpose, we conducted three studies. The first two studies examined the association between general system justification and corruption. In Study 1, a correlational design was run using questionnaires to assess the relation between general system justification and corruption perception as well as corruption intention. In Study 2, an experimental design was conducted manipulating general system justification via exposure to high or low system threat condition, then measuring its effect on corruption perception and corrupt intention. In Study 3, two sub-studies using correlational and experimental designs were run to explore the mediating role of institutional trust, respectively. Results replicated former studies showing that general system justification is negatively associated with corruption perception. However, they also showed a negative correlation with corrupt intention. Furthermore, they showed that institutional trust mediated the relation between general system justification and corruption. We suggest to consider these findings to further elucidate the psychological basis underlying different effects of general system justification on human behaviors.

The Effects of General System Justification on Corruption Perception and Intent

Directory of Open Access Journals (Sweden)

Xuyun Tan

2016-07-01

Full Text Available Previous research stresses that system justifying belief can weaken corruption perception, by this possibly fostering unjust behaviors. However, general results of the effect of general system justification on corruption are ambiguous, indicating also a lessening impact. We conducted a line of studies trying to elucidate these circumstances by testing the effect of general system justification on corruption perception and intention. In addition, we explored institutional trust as a possible mediator in this process. For this purpose we conducted three studies. The first two studies examined the association between general system justification and corruption. In Study 1, a correlational design was run using questionnaires to assess the relation between general system justification and corruption perception as well as corruption intention. In Study 2, an experimental design was conducted manipulating general system justification via exposure to high or low system threat condition, then measuring its effect on corruption perception and corrupt intention. In Study 3, two sub-studies using correlational and experimental designs were run to explore the mediating role of institutional trust, respectively. Results replicated former studies showing that general system justification is negatively associated with corruption perception. However, they also showed a negative correlation with corrupt intention. Furthermore, they showed that institutional trust mediated the relation between general system justification and corruption. We suggest to consider these findings to further elucidate the psychological basis underlying different effects of general system justification on human behaviors.

The effect of cigarillo packaging elements on young adult perceptions of product flavor, taste, smell, and appeal.

Science.gov (United States)

Meernik, Clare; Ranney, Leah M; Lazard, Allison J; Kim, KyungSu; Queen, Tara L; Avishai, Aya; Boynton, Marcella H; Sheeran, Paschal J; Goldstein, Adam O

2018-01-01

Product packaging has long been used by the tobacco industry to target consumers and manipulate product perceptions. This study examines the extent to which cigarillo packaging influences perceptions of product flavor, taste, smell, and appeal. A web-based experiment was conducted among young adults. Participants viewed three randomly selected cigarillo packs, varying on pack flavor descriptor, color, type, branding, and warning-totaling 180 pack images. Mixed-effects models were used to estimate the effect of pack elements on product perceptions. A total of 2,664 current, ever, and never little cigar and cigarillo users participated. Cigarillo packs with a flavor descriptor were perceived as having a more favorable taste (β = 0.21, p product taste (pictorial: β = -0.07, p = .03) and smell (text-only: β = -0.08, p = .01; pictorial: β = -0.09, p = .007), warnings did not moderate the effects of flavor descriptor or color. To our knowledge, this study provides the first quantitative evidence that cigarillo packaging alters consumers' cognitive responses, and warnings on packs do not suffice to overcome the effects of product packaging. The findings support efforts at federal, state, and local levels to prohibit flavor descriptors and their associated product flavoring in non-cigarette products such as cigarillos, along with new data that supports restrictions on flavor cues and colors.

Drug-induced GABA transporter currents enhance GABA release to induce opioid withdrawal behaviors.

Science.gov (United States)

Bagley, Elena E; Hacker, Jennifer; Chefer, Vladimir I; Mallet, Christophe; McNally, Gavan P; Chieng, Billy C H; Perroud, Julie; Shippenberg, Toni S; Christie, MacDonald J

2011-10-30

Neurotransmitter transporters can affect neuronal excitability indirectly via modulation of neurotransmitter concentrations or directly via transporter currents. A physiological or pathophysiological role for transporter currents has not been described. We found that GABA transporter 1 (GAT-1) cation currents directly increased GABAergic neuronal excitability and synaptic GABA release in the periaqueductal gray (PAG) during opioid withdrawal in rodents. In contrast, GAT-1 did not indirectly alter GABA receptor responses via modulation of extracellular GABA concentrations. Notably, we found that GAT-1-induced increases in GABAergic activity contributed to many PAG-mediated signs of opioid withdrawal. Together, these data support the hypothesis that GAT-1 activity directly produces opioid withdrawal signs through direct hyperexcitation of GABAergic PAG neurons and nerve terminals, which presumably enhances GABAergic inhibition of PAG output neurons. These data provide, to the best of our knowledge, the first evidence that dysregulation of a neurotransmitter transporter current is important for the maladaptive plasticity that underlies opiate withdrawal.

Interface tuning of current-induced cooling in molecular circuits

Czech Academy of Sciences Publication Activity Database

Foti, Giuseppe; Vázquez, Héctor

2017-01-01

Roč. 121, č. 2 (2017), s. 1082-1088 ISSN 1932-7447 R&D Projects: GA ČR GA15-19672S Institutional support: RVO:68378271 Keywords : current-induced heating and cooling * molecular junction * Carbene Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 4.536, year: 2016

Disruption of crystalline structure of Sn3.5Ag induced by electric current

International Nuclear Information System (INIS)

Huang, Han-Chie; Lin, Kwang-Lung; Wu, Albert T.

2016-01-01

This study presented the disruption of the Sn and Ag_3Sn lattice structures of Sn3.5Ag solder induced by electric current at 5–7 × 10"3 A/cm"2 with a high resolution transmission electron microscope investigation and electron diffraction analysis. The electric current stressing induced a high degree of strain on the alloy, as estimated from the X-ray diffraction (XRD) peak shift of the current stressed specimen. The XRD peak intensity of the Sn matrix and the Ag_3Sn intermetallic compound diminished to nearly undetectable after 2 h of current stressing. The electric current stressing gave rise to a high dislocation density of up to 10"1"7/m"2. The grain morphology of the Sn matrix became invisible after prolonged current stressing as a result of the coalescence of dislocations.

Perception of low dose radiation risks among radiation researchers in Korea.

Science.gov (United States)

Seong, Ki Moon; Kwon, TaeWoo; Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects perception of radiation exposure.

Perception of low dose radiation risks among radiation researchers in Korea

Science.gov (United States)

Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

2017-01-01

Expert’s risk evaluation of radiation exposure strongly influences the public’s risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts’ radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual’s opinions have often exacerbated the public’s confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years’ research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects risk perception of radiation exposure. PMID:28166286

Effect of ethanol at clinically relevant concentrations on atrial inward rectifier potassium current sensitive to acetylcholine.

Science.gov (United States)

Bébarová, Markéta; Matejovič, Peter; Pásek, Michal; Hořáková, Zuzana; Hošek, Jan; Šimurdová, Milena; Šimurda, Jiří

2016-10-01

Alcohol intoxication tends to induce arrhythmias, most often the atrial fibrillation. To elucidate arrhythmogenic mechanisms related to alcohol consumption, the effect of ethanol on main components of the ionic membrane current is investigated step by step. Considering limited knowledge, we aimed to examine the effect of clinically relevant concentrations of ethanol (0.8-80 mM) on acetylcholine-sensitive inward rectifier potassium current I K(Ach). Experiments were performed by the whole-cell patch clamp technique at 23 ± 1 °C on isolated rat and guinea-pig atrial myocytes, and on expressed human Kir3.1/3.4 channels. Ethanol induced changes of I K(Ach) in the whole range of concentrations applied; the effect was not voltage dependent. The constitutively active component of I K(Ach) was significantly increased by ethanol with the maximum effect (an increase by ∼100 %) between 8 and 20 mM. The changes were comparable in rat and guinea-pig atrial myocytes and also in expressed human Kir3.1/3.4 channels (i.e., structural correlate of I K(Ach)). In the case of the acetylcholine-induced component of I K(Ach), a dual ethanol effect was apparent with a striking heterogeneity of changes in individual cells. The effect correlated with the current magnitude in control: the current was increased by eth-anol in the cells showing small current in control and vice versa. The average effect peaked at 20 mM ethanol (an increase of the current by ∼20 %). Observed changes of action potential duration agreed well with the voltage clamp data. Ethanol significantly affected both components of I K(Ach) even in concentrations corresponding to light alcohol consumption.

Effects of current stressing on the p-Bi2Te3/Sn interfacial reactions

International Nuclear Information System (INIS)

Chan, Hsing-Ting; Lin, Chih-Fan; Yen, Yee-Wen; Chen, Chih-Ming

2016-01-01

The Sn/p-Bi 2 Te 3 /Sn sandwich-type sample was current stressed with a density of 150 A/cm 2 to investigate the effects of current stressing on the p-Bi 2 Te 3 /Sn interfacial reactions. Asymmetrical heating phenomenon was observed at the anodic Sn/p-Bi 2 Te 3 (50 °C) and cathodic p-Bi 2 Te 3 /Sn (120 °C) interfaces due to the Peltier effect. Besides the Peltier effect, the electromigration effect also influenced the growth of the SnTe phase and therefore polarity growth behavior was observed at the two interfaces. The growth of the SnTe phase at the cathodic p-Bi 2 Te 3 /Sn interface was accelerated because Peltier and electromigration effects drove more Sn atoms (dominant diffusion species) for the phase growth. By measuring the electromigration-induced atomic flux of Sn, the product of diffusivity and effective charge number (D × z*) was calculated to be 6.3 × 10 −9 cm 2 s −1 at 120 °C. - Highlights: • Sn/p-Bi 2 Te 3 /Sn sandwich-type sample is current stressed with a density of 150 A/cm 2 . • Passage of an electric current induces Peltier and electromigration effects. • Peltier effect causes asymmetrical heating at the anode and cathode interfaces. • Both effects accelerate the SnTe growth at the cathode interface. • Sn is the dominant diffusion species identified by a marker experiment.

Experimental investigation between attentional-resource effectiveness and perception and diagnosis in nuclear power plants

International Nuclear Information System (INIS)

Ha, Jun Su; Seong, Poong Hyun

2014-01-01

Highlights: • Effectiveness in information searching is measured by two eye-tracking measures. • The relationship between the effectiveness and perception and diagnosis is addressed. • An experimental study is conducted to investigate the relationship. • The experimental results show close correlation. • The eye-tracking measures as inferential measures for perception and diagnosis. - Abstract: Eye-tracking-based measures of attentional-resource effectiveness in information searching such as FIR (fixation to importance ratio) and SAE (selective attention effectiveness) have been developed based on cost-benefit principles. The relationship between the eye-tracking-based measures and perception and diagnosis of operators during operating tasks in main control rooms (MCRs) of nuclear power plants (NPPs) is investigated with experimental studies. The FIR and the SAE, which represent how effectively an operator attends to important information sources, are used as measures of the effectiveness in information searching. Perception failure rate (PFR) and diagnosis score (DS) are used as measures of perception and diagnosis, respectively. Experimental results show that the FIR and the SAE correlate closely with the PFR and the DS, respectively. It is concluded that the FIR and the SAE can be used as inferential measures of perception and diagnosis for human factors in NPP MCRs

Experimental investigation between attentional-resource effectiveness and perception and diagnosis in nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Ha, Jun Su, E-mail: junsu.ha@kustar.ac.ae [Nuclear Engineering Department, Khalifa University of Science, Technology and Research, P.O. Box 127788, Abu Dhabi (United Arab Emirates); Seong, Poong Hyun, E-mail: phseong@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2014-10-15

Highlights: • Effectiveness in information searching is measured by two eye-tracking measures. • The relationship between the effectiveness and perception and diagnosis is addressed. • An experimental study is conducted to investigate the relationship. • The experimental results show close correlation. • The eye-tracking measures as inferential measures for perception and diagnosis. - Abstract: Eye-tracking-based measures of attentional-resource effectiveness in information searching such as FIR (fixation to importance ratio) and SAE (selective attention effectiveness) have been developed based on cost-benefit principles. The relationship between the eye-tracking-based measures and perception and diagnosis of operators during operating tasks in main control rooms (MCRs) of nuclear power plants (NPPs) is investigated with experimental studies. The FIR and the SAE, which represent how effectively an operator attends to important information sources, are used as measures of the effectiveness in information searching. Perception failure rate (PFR) and diagnosis score (DS) are used as measures of perception and diagnosis, respectively. Experimental results show that the FIR and the SAE correlate closely with the PFR and the DS, respectively. It is concluded that the FIR and the SAE can be used as inferential measures of perception and diagnosis for human factors in NPP MCRs.

Transcranial direct current stimulation (tDCS) reverts behavioral alterations and brainstem BDNF level increase induced by neuropathic pain model: Long-lasting effect.

Science.gov (United States)

Filho, Paulo Ricardo Marques; Vercelino, Rafael; Cioato, Stefania Giotti; Medeiros, Liciane Fernandes; de Oliveira, Carla; Scarabelot, Vanessa Leal; Souza, Andressa; Rozisky, Joanna Ripoll; Quevedo, Alexandre da Silva; Adachi, Lauren Naomi Spezia; Sanches, Paulo Roberto S; Fregni, Felipe; Caumo, Wolnei; Torres, Iraci L S

2016-01-04

Neuropathic pain (NP) is a chronic pain modality that usually results of damage in the somatosensory system. NP often shows insufficient response to classic analgesics and remains a challenge to medical treatment. The transcranial direct current stimulation (tDCS) is a non-invasive technique, which induces neuroplastic changes in central nervous system of animals and humans. The brain derived neurotrophic factor plays an important role in synaptic plasticity process. Behavior changes such as decreased locomotor and exploratory activities and anxiety disorders are common comorbidities associated with NP. Evaluate the effect of tDCS treatment on locomotor and exploratory activities, and anxiety-like behavior, and peripheral and central BDNF levels in rats submitted to neuropathic pain model. Rats were randomly divided: Ss, SsS, SsT, NP, NpS, and NpT. The neuropathic pain model was induced by partial sciatic nerve compression at 14 days after surgery; the tDCS treatment was initiated. The animals of treated groups were subjected to a 20 minute session of tDCS, for eight days. The Open Field and Elevated Pluz Maze tests were applied 24 h (phase I) and 7 days (phase II) after the end of tDCS treatment. The serum, spinal cord, brainstem and cerebral cortex BDNF levels were determined 48 h (phase I) and 8 days (phase II) after tDCS treatment by ELISA. The chronic constriction injury (CCI) induces decrease in locomotor and exploratory activities, increases in the behavior-like anxiety, and increases in the brainstem BDNF levels, the last, in phase II (one-way ANOVA/SNK, PtDCS treatment already reverted all these effects induced by CCI (one-way ANOVA/SNK, PtDCS treatment decreased serum and cerebral cortex BDNF levels and it increased these levels in the spinal cord in phase II (one-way ANOVA/SNK, PtDCS reverts behavioral alterations associated to neuropathic pain, indicating possible analgesic and anxiolytic tDCS effects. tDCS treatment induces changes in the BDNF levels

Film-induced Tourism in Finland : Its Current State and Opportunities

OpenAIRE

Anul, Kezban

2013-01-01

The goal of this paper was to evaluate the current state of film-induced tourism in Finland and to create suggestions for further development in the context of international markets. To the knowledge of the author, a comprehensive study about film-induced tourism in Finland has not been undertaken yet. Therefore, the thesis was designed in the form of an exploratory research with the aim to deliver some initial insights and key issues for the broad topic. The paper starts with a general ...

Hydrogen peroxide-induced reduction of delayed rectifier potassium current in hippocampal neurons involves oxidation of sulfhydryl groups.

Science.gov (United States)

Hasan, Sonia M K; Redzic, Zoran B; Alshuaib, Waleed B

2013-07-03

This study examined the effect of H2O2 on the delayed rectifier potassium current (IKDR) in isolated hippocampal neurons. Whole-cell voltage-clamp experiments were performed on freshly dissociated hippocampal CA1 neurons of SD rats before and after treatment with H2O2. To reveal the mechanism behind H2O2-induced changes in IKDR, cells were treated with different oxidizing and reducing agents. External application of membrane permeable H2O2 reduced the amplitude and voltage-dependence of IKDR in a concentration dependent manner. Desferoxamine (DFO), an iron-chelator that prevents hydroxyl radical (OH) generation, prevented H2O2-induced reduction in IKDR. Application of the sulfhydryl-oxidizing agent 5,5 dithio-bis-nitrobenzoic acid (DTNB) mimicked the effect of H2O2. Sulfhydryl-reducing agents dithiothreitol (DTT) and glutathione (GSH) alone did not affect IKDR; however, DTT and GSH reversed and prevented the H2O2-induced inhibition of IKDR, respectively. Membrane impermeable agents GSH and DTNB showed effects only when added intracellularly identifying intracellular sulfhydryl groups as potential targets for hydroxyl-mediated oxidation. However, the inhibitory effects of DTNB and H2O2 at the positive test potentials were completely and partially abolished by DTT, respectively, suggesting an additional mechanism of action for H2O2, that is not shared by DTNB. In summary, this study provides evidence for the redox modulation of IKDR, identifies hydroxyl radical as an intermediate oxidant responsible for the H2O2-induced decrease in current amplitude and identifies intracellular sulfhydryl groups as an oxidative target. Copyright © 2013 Elsevier B.V. All rights reserved.

Perceptions of entitativity and attitude change.

Science.gov (United States)

Rydell, Robert J; McConnell, Allen R

2005-01-01

The current work explored the properties of groups that lead them to be persuasive and the processes through which such persuasion occurs. Because more entitative groups induce greater levels of information processing, their arguments should receive greater elaboration, leading to persuasion when members of groups present strong (vs. weak) counter attitudinal arguments. Experiment 1 explored these hypotheses by examining if idiosyncratic perceptions of group entitativity and manipulations of argument strength affect attitude change and argument elaboration. Experiment 2 experimentally manipulated group entitativity and argument strength independently to examine the causal relationship between entitativity, attitude change, and argument elaboration. In both experiments, it was found that groups greater in entitativity were more persuasive when presenting strong (vs. weak) arguments and induced greater argument elaboration. Implications for our understanding of entitativity, persuasion, and information processing about social groups are discussed.

Risk Analysis and Forecast Service for Geomagnetically Induced Currents in Europe

Science.gov (United States)

Wik, Magnus; Pirjola, Risto; Viljanen, Ari; Lundstedt, Henrik

Geomagnetically induced currents (GIC), occurring during magnetic storms, pose a widespread natural disaster risk to the reliable operation of electric power transmission grids, oil and gas pipelines, telecommunication cables and railway systems. The solar magnetic activity is the cause of GIC. Solar coronal holes can cause recurrent inter-vals of raised geomagnetic activity, and coronal mass ejections (CME) at the Sun, sometimes producing very high speed plasma clouds with enhanced magnetic fields and particle densities, can cause the strongest geomagnetic storms. When the solar wind interacts with the geomag-netic field, energy is transferred to the magnetosphere, driving strong currents in the ionosphere. When these currents change in time a geoelectric field is induced at the surface of the Earth and in the ground. Finally, this field drives GIC in the ground and in any technological conductor systems. The worst consequence of a severe magnetic storm within a power grid is a complete blackout, as happened in the province of Québec, Canada, in March 1989, and in the city of Malmü, Sweden, in October 2003. Gas and oil pipelines are not regarded as vulnerable to the immediate impact of GIC, but the corrosion rate of buried steel pipes can increase due to GIC, which may thus shorten the lifetime of a pipe. European Risk from Geomagnetically Induced Currents (EURISGIC) is an EU project, that, if approved, will produce the first European-wide real-time prototype forecast service of GIC in power systems, based on in-situ solar wind observations and comprehensive simulations of the Earth's magnetosphere. This project focuses on high-voltage power transmission networks, which are probably currently the most susceptible to GIC effects. Geomagnetic storms cover large geographical regions, at times the whole globe. Consequently, power networks are rightly described as being European critical infrastructures whose disruption or destruction could have a significant impact

Relativistic Néel-Order Fields Induced by Electrical Current in Antiferromagnets

KAUST Repository

Železný, J.

2014-10-06

We predict that a lateral electrical current in antiferromagnets can induce nonequilibrium Néel-order fields, i.e., fields whose sign alternates between the spin sublattices, which can trigger ultrafast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intraband and to the intrinsic interband spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we consider bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modeled by a Rashba spin-orbit coupling. We propose an antiferromagnetic memory device with electrical writing and reading.

Relativistic Néel-Order Fields Induced by Electrical Current in Antiferromagnets

KAUST Repository

Železný , J.; Gao, H.; Vý borný , K.; Zemen, J.; Mašek, J.; Manchon, Aurelien; Wunderlich, J.; Sinova, Jairo; Jungwirth, T.

2014-01-01

We predict that a lateral electrical current in antiferromagnets can induce nonequilibrium Néel-order fields, i.e., fields whose sign alternates between the spin sublattices, which can trigger ultrafast spin-axis reorientation. Based on microscopic transport theory calculations we identify staggered current-induced fields analogous to the intraband and to the intrinsic interband spin-orbit fields previously reported in ferromagnets with a broken inversion-symmetry crystal. To illustrate their rich physics and utility, we consider bulk Mn2Au with the two spin sublattices forming inversion partners, and a 2D square-lattice antiferromagnet with broken structural inversion symmetry modeled by a Rashba spin-orbit coupling. We propose an antiferromagnetic memory device with electrical writing and reading.

Effect of Size Change and Brightness Change of Visual Stimuli on Loudness Perception and Pitch Perception of Auditory Stimuli

Directory of Open Access Journals (Sweden)

Syouya Tanabe

2011-10-01

Full Text Available People obtain a lot of information from visual and auditory sensation on daily life. Regarding the effect of visual stimuli on perception of auditory stimuli, studies of phonological perception and sound localization have been made in great numbers. This study examined the effect of visual stimuli on perception in loudness and pitch of auditory stimuli. We used the image of figures whose size or brightness was changed as visual stimuli, and the sound of pure tone whose loudness or pitch was changed as auditory stimuli. Those visual and auditory stimuli were combined independently to make four types of audio-visual multisensory stimuli for psychophysical experiments. In the experiments, participants judged change in loudness or pitch of auditory stimuli, while they judged the direction of size change or the kind of a presented figure in visual stimuli. Therefore they cannot neglect visual stimuli while they judged auditory stimuli. As a result, perception in loudness and pitch were promoted significantly around their difference limen, when the image was getting bigger or brighter, compared with the case in which the image had no changes. This indicates that perception in loudness and pitch were affected by change in size and brightness of visual stimuli.

Investigating stakeholders' perceptions of the link between high STD rates and the current Baltimore City Public Schools' sex education curriculum

Science.gov (United States)

Bolden, Shenell L. T.

The purpose of this exploratory study was to examine key stakeholders' perceptions of the current Baltimore City Public Schools' (BCPS) sex education curriculum and to gain insight into how they believe the curriculum could be modified to be more effective. A mixed methods approach using qualitative and quantitative data collection consisting of a survey, focus group interview, and individual interviews was conducted to gather information on stakeholders' perceptions. The stakeholders included: (1) former students who received their sex education courses in the Baltimore City Public School system (BCPS); (2) teachers in BCPS who were affiliated with the sex education curriculum; (3) health care professionals who screened and/or treated East Baltimore City residents for a sexually transmitted disease (STD) and; (4) one policy maker who was responsible for creating sex education curriculum at the national level. Analysis of the quantitative data from former Baltimore City Public School students revealed a general satisfaction with the current sex education curriculum. However, qualitative data from the same group of stakeholders revealed several changes they thought should be implemented into the program in an effort to improve the current curriculum. Findings from the other groups after qualitative analysis of the interviews suggest three major themes in support of curriculum change: (1) a blended curriculum that integrates both the cognitive and affective learning domains; (2) knowledge of prevention of STD's and pregnancy; and (3) authentic teaching and learning. Results from this study strongly suggest that the Baltimore City Public School system is apathetic to the sexual health needs of students and, therefore, is inadvertently contributing to the high rate of sexually transmitted diseases among young people. Keywords: Abstinence, Affective domain, Indoctrination, Behavior Modification, Cognitive domain, Sex education curriculum, Sexually Transmitted Diseases.

Perceptions of Active Versus Passive Risks, and the Effect of Personal Responsibility.

Science.gov (United States)

Keinan, Ruty; Bereby-Meyer, Yoella

2017-07-01

Not getting vaccinated or not backing up computer files are examples of passive risk taking: risk brought on or magnified by inaction. We suggest the difficulty in paying attention to absences, together with the reduced agency and responsibility that is associated with passive choices, leads to the perception of passive risks as being less risky than equivalent active risks. Using scenarios in which risk was taken either actively or passively, we demonstrate that passive risks are judged as less risky than equivalent active risks. We find the perception of personal responsibility mediates the differences between the perception of passive and active risks. The current research offers an additional explanation for omission or default biases: The passive nature of these choices causes them to appear less risky than they really are.

Finite-size effects on current correlation functions

Science.gov (United States)

Chen, Shunda; Zhang, Yong; Wang, Jiao; Zhao, Hong

2014-02-01

We study why the calculation of current correlation functions (CCFs) still suffers from finite-size effects even when the periodic boundary condition is taken. Two important one-dimensional, momentum-conserving systems are investigated as examples. Intriguingly, it is found that the state of a system recurs in the sense of microcanonical ensemble average, and such recurrence may result in oscillations in CCFs. Meanwhile, we find that the sound mode collisions induce an extra time decay in a current so that its correlation function decays faster (slower) in a smaller (larger) system. Based on these two unveiled mechanisms, a procedure for correctly evaluating the decay rate of a CCF is proposed, with which our analysis suggests that the global energy CCF decays as ˜t-2/3 in the diatomic hard-core gas model and in a manner close to ˜t-1/2 in the Fermi-Pasta-Ulam-β model.

Disruption of crystalline structure of Sn3.5Ag induced by electric current

Energy Technology Data Exchange (ETDEWEB)

Huang, Han-Chie; Lin, Kwang-Lung, E-mail: matkllin@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China); Wu, Albert T. [Department of Chemical and Material Engineering, National Central University, Jhongli 32001, Taiwan (China)

2016-03-21

This study presented the disruption of the Sn and Ag{sub 3}Sn lattice structures of Sn3.5Ag solder induced by electric current at 5–7 × 10{sup 3} A/cm{sup 2} with a high resolution transmission electron microscope investigation and electron diffraction analysis. The electric current stressing induced a high degree of strain on the alloy, as estimated from the X-ray diffraction (XRD) peak shift of the current stressed specimen. The XRD peak intensity of the Sn matrix and the Ag{sub 3}Sn intermetallic compound diminished to nearly undetectable after 2 h of current stressing. The electric current stressing gave rise to a high dislocation density of up to 10{sup 17}/m{sup 2}. The grain morphology of the Sn matrix became invisible after prolonged current stressing as a result of the coalescence of dislocations.

Opposite patterns of change in perception of imagined and physically induced pain over the course of repeated thermal stimulations.

Science.gov (United States)

Gács, B; Szolcsányi, T; Csathó, Á

2017-08-01

Individuals frequently show habituation to repeated noxious heat. However, given the defensive function of human pain processing, it is reasonable to assume that individuals anticipate that they would become increasingly sensitive to repeated thermal pain stimuli. No previous studies have, however, been addressed to this assumption. Therefore, in the current study, we investigated how healthy human individuals imagine the intensity of repeated thermal pain stimulations, and compared this with the intensity ratings given after physically induced thermal pain trials. Healthy participants (N = 20) gave pain intensity ratings in two conditions: imagined and real thermal pain. In the real pain condition, thermal pain stimuli of two intensities (minimal and moderate pain) were delivered in four consecutive trials. The duration of the peak temperature was 20 s, and stimulation was always delivered to the same location. In each trial, participants rated the pain intensity twice, 5 and 15 s after the onset of the peak temperature. In the imagined pain condition, participants were subjected to a reference pain stimulus and then asked to imagine and rate the same sequence of stimulations as in the induced pain condition. Ratings of imagined pain and physically induced pain followed opposite courses over repeated stimulations: Ratings of imagined pain indicated sensitization, whereas ratings for physically induced pain indicated habituation. The findings were similar for minimal and moderate pain intensities. The findings suggest that, rather than habituating to pain, healthy individuals imagine that they would become increasingly sensitive to repeated thermal pain stimuli. This study identified opposite patterns of change in perception of imagined pain (sensitization) and physically induced pain (habituation). The findings show that individuals anticipate that they would become increasingly sensitive to repeated pain stimuli, which might also have clinical implications. �

Light-induced, GTP-binding protein mediated membrane currents of Xenopus oocytes injected with rhodopsin of cephalopods.

Science.gov (United States)

Ando, H; Seidou, M; Kito, Y

1991-01-01

Xenopus oocytes that were injected with rhabdomeric membranes of squid and octopus photoreceptors acquired light sensitivity. The injected oocytes showed a light-induced current having characteristics similar to other G-protein-mediated Cl- currents induced by the activation of other membrane receptors. Pretreatment of the oocytes with pertussis toxin before the injection suppressed the generation of the light-induced current, indicating an ability of cephalopod rhodopsin to cross-react with an endogenous G-protein of Xenopus oocytes.

[Effects of noise competition on monosyllabic and disyllabic word perception in children].

Science.gov (United States)

Liu, H H; Liu, S; Li, Y; Zheng, Z P; Jin, X; Li, J; Ren, C C; Zheng, J; Zhang, J; Chen, M; Hao, J S; Yang, Y; Liu, W; Ni, X

2017-05-07

Objective: The purpose of the present study was to investigate the effects of noise competition on word perception in normal hearing (NH) children and children with cochlear implantation (CI). Methods: To estimate the contribution of noise competition on speech perception, word perception in speech-shaped noise(SSN)and 4-talker babble noise(BN) with Mandarin Lexical Neighborhood Test were performed in 80 NH children and 89 children with CI. Corrected perception percentages were acquired in each group. Results: Both signal to noise ratio (SNR) and noise type influenced the word perception. In NH group, corrected percentages of disyllabic word perception in SSN were 24.2%, 55.9%, 77.1%, 85.1% and 88.9% at -8, -4, 0, 4 and 8 dB SNR, corresponding corrected percentages of monosyllabic word were 13.9%, 39.5%, 60.1%, 68.8% and 80.1%, respectively. In BN noise, corrected percentages of disyllabic word were 2.4%, 24.3%, 55.6%, 74.3% and 86.2%, corresponding monosyllabic word were 2.3%, 20.8%, 47.2%, 61.1% and 74.8%, respectively. In CI group, corrected percentages of dissyllabic word in SSN and BN at 10 dB SNR were 65.5% and 58.1%, respectively. Corresponding monosyllabic word were 49.0% and 41.0%. For SNR=5 dB, corrected percentages of disyllabic word in SSN and BN were 50.0% and 38.1%, corresponding corrected percentages of monosyllabic word were 40.8% and 25.1%, respectively. Analysis indicated that the masking effect were significantly higher in BN compared with SSN. Conclusions: Noise competition influence word perception performance significantly. In specific, the influence of noise on word perception is bigger in children with CI than in NH children. The masking effect is higher in BN noise when compared with SSN.

Comparative Research of Residents’ Effect Perception and Participation Capacity and Willingness on Pro-poor Tourism

Institute of Scientific and Technical Information of China (English)

Guoqing; HUANG; Hong; SHU

2014-01-01

In this article,comparative research on residents’ effect perception,participation capacity and willingness on Pro-poor Tourism( PPT) is given based on the questionnaire carried out in Wulong County and Fengjie County in Three Gorges Area,Chongqing,China. Some technologies,such as SPSS 13. 0,ANOVA and T-test are applied to analyze the data and results show Wulong residents’ perception behavior is better than that of Fengjie residents. Moreover,the residents with different demographic characteristics have different participation behavior.Finally,multiple regression analysis is applied to identify the key factors influencing residents’ perception behavior,that is participation willingness and positive economic effect perception,positive social and cultural effect perception and participation capacity.

Influence of Visual Motion, Suggestion, and Illusory Motion on Self-Motion Perception in the Horizontal Plane.

Science.gov (United States)

Rosenblatt, Steven David; Crane, Benjamin Thomas

2015-01-01

A moving visual field can induce the feeling of self-motion or vection. Illusory motion from static repeated asymmetric patterns creates a compelling visual motion stimulus, but it is unclear if such illusory motion can induce a feeling of self-motion or alter self-motion perception. In these experiments, human subjects reported the perceived direction of self-motion for sway translation and yaw rotation at the end of a period of viewing set visual stimuli coordinated with varying inertial stimuli. This tested the hypothesis that illusory visual motion would influence self-motion perception in the horizontal plane. Trials were arranged into 5 blocks based on stimulus type: moving star field with yaw rotation, moving star field with sway translation, illusory motion with yaw, illusory motion with sway, and static arrows with sway. Static arrows were used to evaluate the effect of cognitive suggestion on self-motion perception. Each trial had a control condition; the illusory motion controls were altered versions of the experimental image, which removed the illusory motion effect. For the moving visual stimulus, controls were carried out in a dark room. With the arrow visual stimulus, controls were a gray screen. In blocks containing a visual stimulus there was an 8s viewing interval with the inertial stimulus occurring over the final 1s. This allowed measurement of the visual illusion perception using objective methods. When no visual stimulus was present, only the 1s motion stimulus was presented. Eight women and five men (mean age 37) participated. To assess for a shift in self-motion perception, the effect of each visual stimulus on the self-motion stimulus (cm/s) at which subjects were equally likely to report motion in either direction was measured. Significant effects were seen for moving star fields for both translation (p = 0.001) and rotation (pperception was shifted in the direction consistent with the visual stimulus. Arrows had a small effect on self

The Effect of Personality Characteristics on Business Students' Perceptions of Cheating

Science.gov (United States)

Elias, Rafik Z.

2015-01-01

Cheating is a common problem among college students. Research shows that business students cheat more often than other students and that this cheating was correlated with future unethical workplace behavior. The current study examines some psychological determinants of business students' cheating perception. A survey was administered to 474…

Changing motor perception by sensorimotor conflicts and body ownership

Science.gov (United States)

Salomon, R.; Fernandez, N. B.; van Elk, M.; Vachicouras, N.; Sabatier, F.; Tychinskaya, A.; Llobera, J.; Blanke, O.

2016-01-01

Experimentally induced sensorimotor conflicts can result in a loss of the feeling of control over a movement (sense of agency). These findings are typically interpreted in terms of a forward model in which the predicted sensory consequences of the movement are compared with the observed sensory consequences. In the present study we investigated whether a mismatch between movements and their observed sensory consequences does not only result in a reduced feeling of agency, but may affect motor perception as well. Visual feedback of participants’ finger movements was manipulated using virtual reality to be anatomically congruent or incongruent to the performed movement. Participants made a motor perception judgment (i.e. which finger did you move?) or a visual perceptual judgment (i.e. which finger did you see moving?). Subjective measures of agency and body ownership were also collected. Seeing movements that were visually incongruent to the performed movement resulted in a lower accuracy for motor perception judgments, but not visual perceptual judgments. This effect was modified by rotating the virtual hand (Exp.2), but not by passively induced movements (Exp.3). Hence, sensorimotor conflicts can modulate the perception of one’s motor actions, causing viewed “alien actions” to be felt as one’s own. PMID:27225834

Effects of Induced Electric Fields on Tissues and Cells

Science.gov (United States)

Sequin, Emily Katherine

Cancer remains a substantial health burden in the United States. Traditional treatments for solid malignancies may include chemotherapy, radiation therapy, targeted therapies, or surgical resection. Improved surgical outcomes coincide with increased information regarding the tumor extent in the operating room. Furthermore, pathological examination and diagnosis is bettered when the pathologist has additional information about lesion locations on the large resected specimens from which they take a small sample for microscopic evaluation. Likewise, cancer metastasis is a leading cause of cancer death. Fully understanding why a particular tumor becomes metastatic as well as the mechanisms of cell migration are critical to both preventing metastasis and treating it. This dissertation utilizes the complex interactions of induced electric fields with tissues and cells to meet two complementary research goals. First, eddy currents are induced in tissues using a coaxial eddy current probe (8mm diameter) in order to distinguish tumor tissue from surrounding normal tissue to address the needs of surgeons performing curative cancer resections. Measurements on animal tissue phantoms characterize the eddy current measurement finding that the effective probing area corresponds to about twice the diameter of the probe and that the specimen temperature must be constant for reliable measurements. Measurements on ten fresh tissue specimens from human patients undergoing surgical resection for liver metastases from colorectal cancer showed that the eddy current measurement technique can be used to differentiate tumors from surrounding liver tissue in a non-destructive, non-invasive manner. Furthermore, the differentiation between the tumor and normal tissues required no use of contrast agents. Statistically significant differences between eddy current measurements in three tissue categories, tumor, normal, and interface, were found across patients using a Tukey's pairwise comparison

The effect of left frontal transcranial direct-current stimulation on propranolol-induced fear memory acquisition and consolidation deficits.

Science.gov (United States)

Nasehi, Mohammad; Khani-Abyaneh, Mozhgan; Ebrahimi-Ghiri, Mohaddeseh; Zarrindast, Mohammad-Reza

2017-07-28

Accumulating evidence supports the efficacy of transcranial direct current stimulation (tDCS) in modulating numerous cognitive functions. Despite the fact that tDCS has been used for the enhancement of memory and cognition, very few animal studies have addressed its impact on the modulation of fear memory. This study was designed to determine whether pre/post-training frontal tDCS application would alter fear memory acquisition and/or consolidation deficits induced by propranolol in NMRI mice. Results indicated that administration of β1-adrenoceptor blocker propranolol (0.1mg/kg) impaired fear memory retrieval. Pre/post-training application of anodal tDCS when propranolol was administered prior to training reversed contextual memory retrieval whereas only the anodal application prior to training could induce the same result in the auditory test. Meanwhile, anodal stimulation had no effect on fear memories by itself. Moreover, regardless of when cathode was applied and propranolol administered, their combination restored contextual memory retrieval, while only cathodal stimulation prior to training facilitated the contextual memory retrieval. Also, auditory memory retrieval was restored when cathodal stimulation and propranolol occurred prior to training but it was abolished when stimulation occurred after training and propranolol was administered prior to training. Collectively, our findings show that tDCS applied on the left frontal cortex of mice affects fear memory performance. This alteration seems to be task-dependent and varies depending on the nature and timing of the stimulation. In certain conditions, tDCS reverses the effect of propranolol. These results provide initial evidence to support the timely use of tDCS for the modulation of fear-related memories. Copyright © 2017 Elsevier B.V. All rights reserved.

Stakeholders’ Perceptions of Effective EFL Teachers

OpenAIRE

Thooptong Kwangsawad

2017-01-01

Teacher preparation is important as the component of teachers’ ongoing learning and development. Well-designed teacher preparation can also be a powerful vehicle for preparing the next generation of teachers to implement new curriculum and innovative teaching methods. The rationale for this quantitative study was to explore stakeholders’ perceptions of effective EFL teachers in the EFL pre-service education program at Mahasarakham University, Thailand. The questionnair...

Nuclear Medicine Technologists' Perception and Current Assessment of Quality: A Society of Nuclear Medicine and Molecular Imaging Technologist Section Survey.

Science.gov (United States)

Mann, April; Farrell, Mary Beth; Williams, Jessica; Basso, Danny

2017-06-01

In 2015, the Society of Nuclear Medicine and Molecular Imaging Technologist Section (SNMMI-TS) launched a multiyear quality initiative to help prepare the technologist workforce for an evidence-based health-care delivery system that focuses on quality. To best implement the quality strategy, the SNMMI-TS first surveyed technologists to ascertain their perception of quality and current measurement of quality indicators. Methods: An internet survey was sent to 27,989 e-mail contacts. Questions related to demographic data, perceptions of quality, quality measurement, and opinions on the minimum level of education are discussed in this article. Results: A total of 4,007 (14.3%) responses were received. When asked to list 3 words or phrases that represent quality, there were a plethora of different responses. The top 3 responses were image quality, quality control, and technologist education or competency. Surveying patient satisfaction was the most common quality measure (80.9%), followed by evaluation of image quality (78.2%). Evaluation of image quality (90.3%) and equipment functionality (89.4%) were considered the most effective measures. Technologists' differentiation between quality, quality improvement, quality control, quality assurance, and quality assessment seemed ambiguous. Respondents were confident in their ability to assess and improve quality at their workplace (91.9%) and agreed their colleagues were committed to delivering quality work. Of note, 70.7% of respondents believed that quality is directly related to the technologist's level of education. Correspondingly, respondents felt there should be a minimum level of education (99.5%) and that certification or registry should be required (74.4%). Most respondents (59.6%) felt that a Bachelor's degree should be the minimum level of education, followed by an Associate's degree (40.4%). Conclusion: To best help nuclear medicine technologists provide quality care, the SNMMI-TS queried technologists to

The effect of phasic auditory alerting on visual perception.

Science.gov (United States)

Petersen, Anders; Petersen, Annemarie Hilkjær; Bundesen, Claus; Vangkilde, Signe; Habekost, Thomas

2017-08-01

Phasic alertness refers to a short-lived change in the preparatory state of the cognitive system following an alerting signal. In the present study, we examined the effect of phasic auditory alerting on distinct perceptual processes, unconfounded by motor components. We combined an alerting/no-alerting design with a pure accuracy-based single-letter recognition task. Computational modeling based on Bundesen's Theory of Visual Attention was used to examine the effect of phasic alertness on visual processing speed and threshold of conscious perception. Results show that phasic auditory alertness affects visual perception by increasing the visual processing speed and lowering the threshold of conscious perception (Experiment 1). By manipulating the intensity of the alerting cue, we further observed a positive relationship between alerting intensity and processing speed, which was not seen for the threshold of conscious perception (Experiment 2). This was replicated in a third experiment, in which pupil size was measured as a physiological marker of alertness. Results revealed that the increase in processing speed was accompanied by an increase in pupil size, substantiating the link between alertness and processing speed (Experiment 3). The implications of these results are discussed in relation to a newly developed mathematical model of the relationship between levels of alertness and the speed with which humans process visual information. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanism of Estradiol-Induced Block of Voltage-Gated K+ Currents in Rat Medial Preoptic Neurons

Science.gov (United States)

Druzin, Michael; Malinina, Evgenya; Grimsholm, Ola; Johansson, Staffan

2011-01-01

The present study was conducted to characterize possible rapid effects of 17-β-estradiol on voltage-gated K+ channels in preoptic neurons and, in particular, to identify the mechanisms by which 17-β-estradiol affects the K+ channels. Whole-cell currents from dissociated rat preoptic neurons were studied by perforated-patch recording. 17-β-estradiol rapidly (within seconds) and reversibly reduced the K+ currents, showing an EC50 value of 9.7 µM. The effect was slightly voltage dependent, but independent of external Ca2+, and not sensitive to an estrogen-receptor blocker. Although 17-α-estradiol also significantly reduced the K+ currents, membrane-impermeant forms of estradiol did not reduce the K+ currents and other estrogens, testosterone and cholesterol were considerably less effective. The reduction induced by estradiol was overlapping with that of the KV-2-channel blocker r-stromatoxin-1. The time course of K+ current in 17-β-estradiol, with a time-dependent inhibition and a slight dependence on external K+, suggested an open-channel block mechanism. The properties of block were predicted from a computational model where 17-β-estradiol binds to open K+ channels. It was concluded that 17-β-estradiol rapidly reduces voltage-gated K+ currents in a way consistent with an open-channel block mechanism. This suggests a new mechanism for steroid action on ion channels. PMID:21625454

Inhibitory Effects of Edaravone in β-Amyloid-Induced Neurotoxicity in Rats

Directory of Open Access Journals (Sweden)

Feng He

2014-01-01

Full Text Available Amyloid protein can damage nerve cells through a variety of biological mechanisms including oxidative stress, alterations in calcium homeostasis, and proapoptosis. Edaravone, a potent free radical scavenger possessing antioxidant effects, has been proved neuroprotective effect in stroke patients. The current study aimed to investigate the effects of EDA in an Aβ-induced rat model of AD, by studying Aβ1–40-induced voltage-gated calcium channel currents in hippocampal CA1 pyramidal neurons, learning and memory behavioral tests, the number of surviving cholinergic neurons in the basal forebrain, and the acetylcholine level in the hippocampus in this rat model of AD. The results showed that the Aβ1–40-induced increase of ICa can be inhibited by EDA in a dose-dependent manner. Treatment with EDA significantly improved Aβ1–40-induced learning and memory performance. Choline acetyltransferase positive cells in basal forebrain and acetylcholine content in the hippocampus were increased by the administration of EDA as compared with the non-EDA treated Aβ1–40 group. These results demonstrate that EDA can inhibit the neurotoxic effect of Aβ toxicity. Collectively, these findings suggest that EDA may serve as a potential complemental treatment strategy for AD.

Role of action potential configuration and the contribution of Ca2+ and K+ currents to isoprenaline-induced changes in canine ventricular cells

Science.gov (United States)

Szentandrássy, N; Farkas, V; Bárándi, L; Hegyi, B; Ruzsnavszky, F; Horváth, B; Bányász, T; Magyar, J; Márton, I; Nánási, PP

2012-01-01

BACKGROUND AND PURPOSE Although isoprenaline (ISO) is known to activate several ion currents in mammalian myocardium, little is known about the role of action potential morphology in the ISO-induced changes in ion currents. Therefore, the effects of ISO on action potential configuration, L-type Ca2+ current (ICa), slow delayed rectifier K+ current (IKs) and fast delayed rectifier K+ current (IKr) were studied and compared in a frequency-dependent manner using canine isolated ventricular myocytes from various transmural locations. EXPERIMENTAL APPROACH Action potentials were recorded with conventional sharp microelectrodes; ion currents were measured using conventional and action potential voltage clamp techniques. KEY RESULTS In myocytes displaying a spike-and-dome action potential configuration (epicardial and midmyocardial cells), ISO caused reversible shortening of action potentials accompanied by elevation of the plateau. ISO-induced action potential shortening was absent in endocardial cells and in myocytes pretreated with 4-aminopyridine. Application of the IKr blocker E-4031 failed to modify the ISO effect, while action potentials were lengthened by ISO in the presence of the IKs blocker HMR-1556. Both action potential shortening and elevation of the plateau were prevented by pretreatment with the ICa blocker nisoldipine. Action potential voltage clamp experiments revealed a prominent slowly inactivating ICa followed by a rise in IKs, both currents increased with increasing the cycle length. CONCLUSIONS AND IMPLICATIONS The effect of ISO in canine ventricular cells depends critically on action potential configuration, and the ISO-induced activation of IKs– but not IKr– may be responsible for the observed shortening of action potentials. PMID:22563726

The effects of antiepileptic inducers in neuropsychopharmacology, a neglected issue. Part I: A summary of the current state for clinicians.

Science.gov (United States)

de Leon, Jose

2015-01-01

The literature on inducers in epilepsy and bipolar disorder is seriously contaminated by false negative findings. This is part i of a comprehensive review on antiepileptic drug (AED) inducers using both mechanistic pharmacological and evidence-based medicine to provide practical recommendations to neurologists and psychiatrists concerning how to control for them. Carbamazepine, phenobarbital and phenytoin, are clinically relevant AED inducers; correction factors were calculated for studied induced drugs. These correction factors are rough simplifications for orienting clinicians, since there is great variability in the population regarding inductive effects. As new information is published, the correction factors may need to be modified. Some of the correction factors are so high that the drugs (e.g., bupropion, quetiapine or lurasidone) should not co-prescribed with potent inducers. Clobazam, eslicarbazepine, felbamate, lamotrigine, oxcarbazepine, rufinamide, topiramate, vigabatrin and valproic acid are grouped as mild inducers which may (i)be inducers only in high doses; (ii)frequently combine with inhibitory properties; and (iii)take months to reach maximum effects or de-induction, definitively longer than the potent inducers. Potent inducers, definitively, and mild inducers, possibly, have relevant effects in the endogenous metabolism of (i)sexual hormones, (ii) vitamin D, (iii)thyroid hormones, (iv)lipid metabolism, and (v)folic acid. Copyright © 2014 SEP y SEPB. Published by Elsevier España. All rights reserved.

A review on stray current-induced steel corrosion in infrastructure

NARCIS (Netherlands)

Chen, Zhipei; Koleva, D.A.; van Breugel, K.

2017-01-01

Metallic corrosion can cause substantial damage at various levels and in almost all types of infrastructure. For metallic corrosion to occur, a certain external environment and the presence of corrodents are the prerequisites. Stray current-induced corrosion, however, is a rather underestimated

[Perception of health risks: psychological and social factors].

Science.gov (United States)

Kurzenhäuser, S; Epp, A

2009-12-01

This article reviews central findings and current developments of psychological and sociological research on the perception of health risks. Risk perception is influenced by numerous psychological, social, political, and cultural factors. These factors can be categorized into (a) risk characteristics, (b) characteristics of the risk perceiving person and his/her situation, and (c) characteristics of risk communication. Thus, besides individual cognitive and affective processing of risk information, social processes of risk amplification (e.g., media effects) are also involved in the construction of individual risk perceptions. We discuss the recommendations for health risk communication that follow from these findings with regard to different communication goals.

Chronic Enhancement of Serotonin Facilitates Excitatory Transcranial Direct Current Stimulation-Induced Neuroplasticity.

Science.gov (United States)

Kuo, Hsiao-I; Paulus, Walter; Batsikadze, Giorgi; Jamil, Asif; Kuo, Min-Fang; Nitsche, Michael A

2016-04-01

Serotonin affects memory formation via modulating long-term potentiation (LTP) and depression (LTD). Accordingly, acute selective serotonin reuptake inhibitor (SSRI) administration enhanced LTP-like plasticity induced by transcranial direct current stimulation (tDCS) in humans. However, it usually takes some time for SSRI to reduce clinical symptoms such as anxiety, negative mood, and related symptoms of depression and anxiety disorders. This might be related to an at least partially different effect of chronic serotonergic enhancement on plasticity, as compared with single-dose medication. Here we explored the impact of chronic application of the SSRI citalopram (CIT) on plasticity induced by tDCS in healthy humans in a partially double-blinded, placebo (PLC)-controlled, randomized crossover study. Furthermore, we explored the dependency of plasticity induction from the glutamatergic system via N-methyl-D-aspartate receptor antagonism. Twelve healthy subjects received PLC medication, combined with anodal or cathodal tDCS of the primary motor cortex. Afterwards, the same subjects took CIT (20 mg/day) consecutively for 35 days. During this period, four additional interventions were performed (CIT and PLC medication with anodal/cathodal tDCS, CIT and dextromethorphan (150 mg) with anodal/cathodal tDCS). Plasticity was monitored by motor-evoked potential amplitudes elicited by transcranial magnetic stimulation. Chronic application of CIT increased and prolonged the LTP-like plasticity induced by anodal tDCS for over 24 h, and converted cathodal tDCS-induced LTD-like plasticity into facilitation. These effects were abolished by dextromethorphan. Chronic serotonergic enhancement results in a strengthening of LTP-like glutamatergic plasticity, which might partially explain the therapeutic impact of SSRIs in depression and other neuropsychiatric diseases.

Effect of ambient temperature on human pain and temperature perception.

Science.gov (United States)

Strigo, I A; Carli, F; Bushnell, M C

2000-03-01

Animal studies show reduced nociceptive responses to noxious heat stimuli and increases in endogenous beta-endorphin levels in cold environments, suggesting that human pain perception may be dependent on ambient temperature. However, studies of changes in local skin temperature on human pain perception have yielded variable results. This study examines the effect of both warm and cool ambient temperature on the perception of noxious and innocuous mechanical and thermal stimuli. Ten subjects (7 men and 3 women, aged 20-23 yr) used visual analog scales to rate the stimulus intensity, pain intensity, and unpleasantness of thermal (0-50 degrees C) and mechanical (1.2-28.9 g) stimuli applied on the volar forearm with a 1-cm2 contact thermode and von Frey filaments, respectively. Mean skin temperatures were measured throughout the experiment by infrared pyrometer. Each subject was tested in ambient temperatures of 15 degrees C (cool), 25 degrees C (neutral), and 35 degrees C (warm) on separate days, after a 30-min acclimation to the environment. Studies began in the morning after an 8-h fast. Mean skin temperature was altered by ambient temperature (cool room: 30.1 degrees C; neutral room: 33.4 degrees C; warm room: 34.5 degrees C; P cool than in the neutral environment (P cool room and that noxious heat stimuli were more unpleasant in a warm environment. Environmental temperature did not alter ratings of warm (37 and 40 degrees C) or mechanical stimuli. These results indicate that, in humans, a decrease in skin temperature following exposure to cool environments reduces thermal pain. Suppression of Adelta primary afferent cold fiber activity has been shown to increase cold pain produced by skin cooling. Our current findings may represent the reverse phenomenon, i.e., a reduction in thermal nociceptive transmission by the activation of Adelta cutaneous cold fibers.

Odd-parity currents induced by dynamic deformations in graphene-like systems

International Nuclear Information System (INIS)

Zhang, Kai; Zhang, Erhu; Chen, Huawei; Zhang, Shengli

2016-01-01

Reduced (3  +  1)-dimensional Dirac systems with inter-pseudo-spin and inter-valley scattering are employed to investigate current responses to (chiral) gauge fields in graphene-like systems. From (chiral) current—(chiral) current correlation functions, we derive the current responses. Except for electric currents induced by external gauge fields, we find the inter-valley scattering can break the topological nature of odd-parity currents. Given the proper conditions, this property can help us realize valley-polarized electric currents. Through the dynamic deformations generating the chiral gauge fields, we find the vortex-like currents while their profiles can be tuned by superposition of some deformations. In particular, we find a more manageable approach to realize the topological electric current by choosing a linear dynamic deformation. (paper)

Mutual influence between current-induced giant magnetoresistance and radiation-induced magnetoresistance oscillations in the GaAs/AlGaAs 2DES

OpenAIRE

Samaraweera, R. L.; Liu, H.-C.; Wang, Z.; Reichl, C.; Wegscheider, W.; Mani, R. G.

2017-01-01

Radiation-induced magnetoresistance oscillations are examined in the GaAs/AlGaAs 2D system in the regime where an observed concurrent giant magnetoresistance is systematically varied with a supplementary dc-current, I dc . The I dc tuned giant magnetoresistance is subsequently separated from the photo-excited oscillatory resistance using a multi-conduction model in order to examine the interplay between the two effects. The results show that the invoked multiconduction model describes the obs...

Observations and modeling of tsunami-induced currents in ports and harbors

Science.gov (United States)

Lynett, Patrick J.; Borrero, Jose C.; Weiss, Robert; Son, Sangyoung; Greer, Dougal; Renteria, Willington

2012-04-01

Tsunamis, or "harbor waves" in Japanese, are so-named due to common observations of enhanced wave heights, currents and damage in harbors and ports. However, dynamic currents induced by these waves, while regularly observed and known to cause significant damage, are poorly understood. Observations and modeling of the currents induced by the 2011 Tohoku and 2004 Indian Ocean tsunamis allows us to show that the strongest flows in harbor basins are governed by horizontally sheared and rotational shallow features, such as jets and large eddies. When examining currents in harbors, this conclusion will generally require a simulation approach that both includes the relevant physical processes in the governing equations and uses a numerical scheme that does not artificially damp these features. Without proper representation of the physics associated with these phenomena, predictive models may provide drag force estimates that are an order of magnitude or more in error. The immediate implementation of this type of analysis into tsunami hazard studies can mean the difference between an unaffected port and one in which 300 m long container vessels are detached from their moorings and drift chaotically.

teachers' perception of their head teachers' role effectiveness

African Journals Online (AJOL)

Global Journal

This paper is a survey study focused on teacher's perception of their head teachers' role effectiveness. Two research ... children at this level must be of high quality. Ngada (2009) states .... The statistical analysis techniques used in testing this ...

Silicon radiation detector analysis using back electron beam induced current

International Nuclear Information System (INIS)

Guye, R.

1987-01-01

A new technique for the observation and analysis of defects in silicon radiation detectors is described. This method uses an electron beam from a scanning electron microscope (SEM) impinging on the rear side of the p + n junction of the silicon detector, which itself is active and detects the electron beam induced current (EBIC). It is shown that this current is a sensitive probe of localized trapping centers, either at the junction surface or somewhere in the volume of the silicon crystal. (orig.)

The Monetary Effect of Power: How Perception of Power Affects Monetary Value Judgments in China and US

OpenAIRE

Qian Yang; Kaiping Peng; Xueya Zhou; Ruoqiao Zheng; Wanhua Peng

2013-01-01

Previous research has found a positive correlation between the perception of power and the perception of a number of social attributes (e.g., attractiveness, height, personality traits), but most of the studies were conducted in the US, and none has investigated the relationship between power perception and monetary value judgments. The current study found dramatic differences between Americans and Chinese on value estimations; the Chinese seem to perceive much higher monetary values for all ...

Rectifying the Optical-Field-Induced Current in Dielectrics: Petahertz Diode.

Science.gov (United States)

Lee, J D; Yun, Won Seok; Park, Noejung

2016-02-05

Investigating a theoretical model of the optical-field-induced current in dielectrics driven by strong few-cycle laser pulses, we propose an asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with a low hole mass (m_{h}^{*}≪m_{e}^{*}) and low electron mass (m_{e}^{*}≪m_{h}^{*}), respectively. This proposition introduces the novel concept of a petahertz (10^{15}  Hz) diode to rectify the current in the petahertz domain, which should be a key ingredient for the electric signal manipulation of future light-wave electronics. Further, we suggest the candidate dielectrics for the heterojunction.

VEGF attenuated increase of outward delayed-rectifier potassium currents in hippocampal neurons induced by focal ischemia via PI3-K pathway.

Science.gov (United States)

Wu, K W; Yang, P; Li, S S; Liu, C W; Sun, F Y

2015-07-09

We recently indicated that the vascular endothelial growth factor (VEGF) protects neurons against hypoxic death via enhancement of tyrosine phosphorylation of Kv1.2, an isoform of the delayed-rectifier potassium channels through activation of the phosphatidylinositol 3-kinase (PI3-K) signaling pathway. The present study investigated whether VEGF could attenuate ischemia-induced increase of the potassium currents in the hippocampal pyramidal neurons of rats after ischemic injury. Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion (MCAO) to induce brain ischemia. The whole-cell patch-clamp technique was used to record the potassium currents of hippocampal neurons in brain slices from the ischemically injured brains of the rats 24h after MCAO. We detected that transient MCAO caused a significant increase of voltage-gated potassium currents (Kv) and outward delayed-rectifier potassium currents (IK), but not outward transient potassium currents (IA), in the ipsilateral hippocampus compared with the sham. Moreover, we found that VEGF could acutely, reversibly and voltage-dependently inhibit the ischemia-induced IK increase. This inhibitory effect of VEGF could be completely abolished by wortmannin, an inhibitor of PI3-K. Our data indicate that VEGF attenuates the ischemia-induced increase of IK via activation of the PI3-K signaling pathway. Published by Elsevier Ltd.

The Effect of Lifestyle, Perception, Satisfaction, and Preference on The Online Re-purchase Intention

Directory of Open Access Journals (Sweden)

Winda Victoria Pebriani

2018-06-01

Full Text Available The objective of this research was to analyze the effect of lifestyle, perception, satisfaction, and preference on the online re-purchase intention. The data are collected from 218 women consumers who have bought Muslim clothing through e-commerce (Hijup and social network (Instagram at least two times in the last three months. The data are analyzed using t-test and Structural Equation Modelling (SEM. The result of this research indicates that lifestyle has a significant effect on perception, perception has an effect on satisfaction, satisfaction has an effect on preference, and preference has an effect on re-purchase intention. Meanwhile, satisfaction has no significant effect on re-purchase intention in both models.

Social Media in Education: The Relationship between Past Use and Current Perceptions

Science.gov (United States)

Settle, Quisto; Telg, Ricky; Baker, Lauri M.; Irani, Tracy; Rhoades, Emily; Rutherford, Tracy

2012-01-01

The purpose of this study was to assess the relationship between prior use of social media in education and the perception of social media use in education and for future careers. College agriculture students and instructors were surveyed to address the objectives. The descriptive measures showed that instructors had more positive perceptions of…

S3-1: The Serial Dependence of Visual Perception

Directory of Open Access Journals (Sweden)

David Whitney

2012-10-01

Full Text Available In our moment-to-moment perceptual experience, visual scenes can change, but objects rarely spontaneously come into or out of existence. The visual system may therefore delicately balance the need to optimize sensitivity to image changes (e.g., by adapting to changes in color, orientation, object identity, etc with the desire to represent the temporal continuity of objects—the likelihood that objects perceived at this moment tend to exist in subsequent moments. One way that the visual system may promote such stability is through the introduction of serial dependence to visual perception: by biasing the current percept toward what was seen at previous moments, the brain could compensate for variability in visual input that might otherwise disrupt perceptual continuity. Here, in two sets of experiments, we tested for serial dependence in visual perception of orientation and facial expression. We found that on a given trial, a subject's perception of the orientation of a grating reflected not only the currently viewed stimulus, but also a systematic attraction toward the orientations of the previously viewed stimuli. We found the same serial dependence in the perception of facial expression. This perceptual attraction extended over several trials and seconds, and displayed clear tuning to the difference (in orientation or facial expression between the sequential stimuli. Furthermore, serial dependence in object perception was spatially specific and selective to the attended object within a scene. Several control experiments showed that the perceptual serial dependence we report cannot be explained by effects of priming, known hysteresis effects, visual short-term memory, or expectation. Our results reveal a systematic influence of recent visual experiences on perception at any given moment: visual percepts, even of unambiguous stimuli, are attracted toward what was previously seen. We propose that such serial dependence helps to maintain

Exercise in obese pregnant women: positive impacts and current perceptions

Directory of Open Access Journals (Sweden)

Sui Z

2013-07-01

Full Text Available Zhixian Sui,1 Jodie M Dodd1,21The University of Adelaide, Robinson Institute, Discipline of Obstetrics and Gynaecology, Women’s and Children’s Hospital, 2Department of Perinatal Medicine, Women’s and Babies Division, Women’s and Children’s Hospital, Adelaide, SA, AustraliaAbstract: Overweight and obesity have significant implications during pregnancy and childbirth. The objective of this review was to provide a comprehensive overview of the effect of physical activity on pregnancy outcomes, the change of physical activity during pregnancy, and women’s perception of being physically active during pregnancy, with a particular focus on women who are overweight or obese. Many studies have investigated the beneficial effect of exercise during pregnancy, including reduced risk of gestational diabetes, preeclampsia, and operative birth, in addition to improved cardiovascular function, overall fitness, psychological well-being, and mood stability. Benefits for the infant include reduced risks of prematurity and improved fetal growth, although there is more limited information about longer-term health benefits for both women and infants. The existing literature examining physical activity patterns during pregnancy has generally focused on women of all body mass index categories, consistently indicating a reduction in activity over the course of pregnancy. However, the available literature evaluating physical activity during pregnancy among women who are overweight or obese is more limited and contradictory. A number of studies identified barriers preventing women from being active during pregnancy, including pregnancy symptoms, lack of time, access to child care, and concerns about their safety and that of their unborn baby. Conversely, significant enablers included positive psychological feelings, family influence, and receiving advice from health professionals. Very few studies have provided insights about perceptions of being active during

Antiresonance induced spin-polarized current generation

Science.gov (United States)

Yin, Sun; Min, Wen-Jing; Gao, Kun; Xie, Shi-Jie; Liu, De-Sheng

2011-12-01

According to the one-dimensional antiresonance effect (Wang X R, Wang Y and Sun Z Z 2003 Phys. Rev. B 65 193402), we propose a possible spin-polarized current generation device. Our proposed model consists of one chain and an impurity coupling to the chain. The energy level of the impurity can be occupied by an electron with a specific spin, and the electron with such a spin is blocked because of the antiresonance effect. Based on this phenomenon our model can generate the spin-polarized current flowing through the chain due to different polarization rates. On the other hand, the device can also be used to measure the generated spin accumulation. Our model is feasible with today's technology.

GABA shapes the dynamics of bistable perception.

Science.gov (United States)

van Loon, Anouk M; Knapen, Tomas; Scholte, H Steven; St John-Saaltink, Elexa; Donner, Tobias H; Lamme, Victor A F

2013-05-06

Sometimes, perception fluctuates spontaneously between two distinct interpretations of a constant sensory input. These bistable perceptual phenomena provide a unique window into the neural mechanisms that create the contents of conscious perception. Models of bistable perception posit that mutual inhibition between stimulus-selective neural populations in visual cortex plays a key role in these spontaneous perceptual fluctuations. However, a direct link between neural inhibition and bistable perception has not yet been established experimentally. Here, we link perceptual dynamics in three distinct bistable visual illusions (binocular rivalry, motion-induced blindness, and structure from motion) to measurements of gamma-aminobutyric acid (GABA) concentrations in human visual cortex (as measured with magnetic resonance spectroscopy) and to pharmacological stimulation of the GABAA receptor by means of lorazepam. As predicted by a model of neural interactions underlying bistability, both higher GABA concentrations in visual cortex and lorazepam administration induced slower perceptual dynamics, as reflected in a reduced number of perceptual switches and a lengthening of percept durations. Thus, we show that GABA, the main inhibitory neurotransmitter, shapes the dynamics of bistable perception. These results pave the way for future studies into the competitive neural interactions across the visual cortical hierarchy that elicit conscious perception. Copyright © 2013 Elsevier Ltd. All rights reserved.

Inhibition by sigma receptor ligand, MS-377, of N-methyl- D-aspartate-induced currents in dopamine neurons of the rat ventral tegmental area.

Science.gov (United States)

Yamazaki, Yuu; Ishioka, Miwa; Matsubayashi, Hiroaki; Amano, Taku; Sasa, Masashi

2002-04-01

MS-377 [( R)-(+)-1-(4-chlorophenyl)-3-[4-(2-methoxyethyl) piperazin-1-yl]methyl-2-pyrrolidinone L-tartrate] is a novel anti-psychotic drug candidate with high affinity for sigma receptors but devoid of binding affinity for PCP binding site of NMDA receptor/ion channel complex. The effects of MS-377 on NMDA receptor and/or its ion channel complex were examined to elucidate the antipsychotic properties of MS-377. We examined the effect of MS-377 on NMDA ( N-methyl- D-aspartate)-induced current in acutely dissociated dopamine neurons of rat ventral tegmental area (VTA) using patch clamp whole cell recording. MS-377 applied in a bath inhibited the peak current evoked by NMDA applied via the U-tube method for 2 s in a concentration-dependent manner. Other sigma receptor ligands, BD-1063 (1-[2-(3,4-dichlorophenyl)ethyl]-4-methylpiperazine), NE-100 ( N, N-dipropyl-2-[4-methoxy-3-(2-phenylenoxy)-phenyl]-ethylamine monohydrochloride) and haloperidol also inhibited NMDA-induced current in a concentration-dependent manner. Interestingly, concomitant application of MS-377 with BD-1063, NE-100 or haloperidol at concentrations that had no effects on NMDA-induced current, potentiated the MS-377-induced inhibition. The results suggest that MS-377, as well as other sigma receptor ligands, indirectly acts on the sigma receptor to inhibit glutaminergic transmission mediated by NMDA receptor/ion channel complex in VTA dopamine neurons, thereby inhibiting dopamine release in target VTA areas.

The effect of psychosocial factors and patients' perception of ...

African Journals Online (AJOL)

The effect of psychosocial factors and patients' perception of tuberculosis treatment ... psychological distress, alcohol use, tobacco smoking and six HBM domains. ... with health promotion intervention to enhance TB treatment adherence.

Focusing on appraisals: how and why anger and fear influence driving risk perception.

Science.gov (United States)

Lu, Jingyi; Xie, Xiaofei; Zhang, Ruogu

2013-06-01

The present research explores how and why anger and fear influence driving risk perception. Based on appraisal tendency framework, researchers hypothesized that anger and fear would influence driving risk perception in opposite directions due to their differences in appraisals. Study 1 showed that anger reduced risk perception, whereas fear increased it. In Studies 2, 3, and 4, the researchers adopted the paradigm of reappraisal to investigate the causes of the opposite effects found in Study 1. Consistent with our hypothesis, appraisals accounted for these effects: After reappraisals along the dimensions of certainty (Study 2), control (Study 3), and responsibility (Study 4), the different effects between anger and fear on driving risk perception diminished or disappeared. In addition, fearful or angry experience mediated the effects of reappraisals on driving risk perception. The findings highlight the necessity to differentiate anger and fear in road safety management. Additionally, the current research also provides feasible methods (e.g., certainty, control, or responsibility reappraisal) to intervene in driving risk perception, which is important for driving safety. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Edge integration and the perception of brightness and darkness

NARCIS (Netherlands)

Vladusich, T.; Lucassen, M.P.; Cornelissen, F.W.

2006-01-01

How do induced brightness and darkness signals from local and remote surfaces interact to determine the final achromatic color percept of a target surface? An emerging theory of achromatic color perception posits that brightness and darkness percepts are computed by weighting and summing the

A current assessment of diversity characteristics and perceptions of their importance in the surgical workforce.

Science.gov (United States)

French, Judith C; O'Rourke, Colin; Walsh, R Matthew

2014-11-01

Diversity in the workforce is vital to successful businesses. Healthcare in general has suffered from a lack of cultural competence, which is the ability to successfully interact with individuals from diverse backgrounds. In order to eliminate discrimination and build a diverse workforce, physicians' perceptions and importance of diversity need to be measured. A 25-item, anonymous, online questionnaire was created, and a cross-sectional survey was performed. The instrument consisted of demographic and Likert-style questions which attempted to determine the participants' perceptions of the current level of diversity in their specialty and their perceived importance of particular diversity categories. Over 1,000 responses were received from US-based physicians across all specialties and levels of training. Statistically significant differences existed between surgical and nonsurgical specialties with regard to gender, prior work experience, and political identity. In the surgical workforce, there is significant perceived homogeneity regarding gender/sexual identity. Surgical respondents also deemed gender/sexual identity diversity to be less important than respondents from medical specialties. Surgeons and surgical trainees are less diverse than their medical colleagues, both by demographics and self-acknowledgement. The long-term impact and potential barriers to resolve these differences in diversity require further investigation.

The white (male) effect and risk perception: can equality make a difference?

Science.gov (United States)

Olofsson, Anna; Rashid, Saman

2011-06-01

Previous research has shown that white males have a relatively low perception of risks, known as the "white male effect" (WME). Many of the explanations of this effect refer to the privileged position of this particular demographic group in society, adducing white males' socio-economic resources, sense of control, worldviews, etc. It can thus be argued that inequality leads women and ethnic minorities to have higher risk perception than men and the ethnic majority. Therefore, the aim of this study is to investigate the WME in a gender-equal country, Sweden, to see if the pattern is similar to previous studies from the comparably less gender-equal United States. The empirical analyses are based on a national survey (n= 1,472) on the perception of risk conducted in Sweden in the winter of 2005. The results show that in Sweden there is no significant difference between men and women in risk perception, while people with foreign backgrounds perceive risks higher than native people. The chief finding is that there is no WME in Sweden, which we concluded results from the relative equality between the sexes in the country. On the other hand, ethnicity serves as a marker of inequality and discrimination in Sweden. Consequently, ethnicity, in terms of foreign background, mediates inequality, resulting in high risk perception. Equality therefore seems to be a fruitful concept with which to examine differences in risk perception between groups in society, and we propose that the "societal inequality effect" is a more proper description than the "WME." © 2011 Society for Risk Analysis.

Validation of Finite-Element Models of Persistent-Current Effects in Nb3Sn Accelerator Magnets

International Nuclear Information System (INIS)

Wang, X.; Ambrosio, G.; Chlachidze, G.; Collings, E. W.; Dietderich, D. R.; DiMarco, J.; Felice, H.; Ghosh, A. K.; Godeke, A.; Gourlay, S. A.; Marchevsky, M.; Prestemon, S. O.; Sabbi, G.; Sumption, M. D.; Velev, G. V.; Xu, X.; Zlobin, A. V.

2015-01-01

Persistent magnetization currents are induced in superconducting filaments during the current ramping in magnets. The resulting perturbation to the design magnetic field leads to field quality degradation, in particular at low field where the effect is stronger relative to the main field. The effects observed in NbTi accelerator magnets were reproduced well with the critical-state model. However, this approach becomes less accurate for the calculation of the persistent-current effects observed in Nb 3 Sn accelerator magnets. Here a finite-element method based on the measured strand magnetization is validated against three state-of-art Nb3Sn accelerator magnets featuring different subelement diameters, critical currents, magnet designs and measurement temperatures. The temperature dependence of the persistent-current effects is reproduced. Based on the validated model, the impact of conductor design on the persistent current effects is discussed. The performance, limitations and possible improvements of the approach are also discussed

Current-induced magnetic switching of a single molecule magnet on a spin valve

International Nuclear Information System (INIS)

Zhang, Xiao; Wang, Zheng-Chuan; Zheng, Qing-Rong; Zhu, Zheng-Gang; Su, Gang

2015-01-01

The current-induced magnetic switching of a single-molecule magnet (SMM) attached on the central region of a spin valve is explored, and the condition for the switching current is derived. Electrons flowing through the spin valve will interact with the SMM via the s–d exchange interaction, producing the spin accumulation that satisfies the spin diffusion equation. We further describe the spin motion of the SMM by a Heisenberg-like equation. Based on the linear stability analysis, we obtain the critical current from two coupled equations. The results of the critical current versus the external magnetic field indicate that one can manipulate the magnetic state of the SMM by an external magnetic field. - Highlights: • We theoretically study the current-induced magnetic switching of the SMM. • We describe the spin motion of the SMM by a Heisenberg-like equation. • We describe the spin accumulation by the spin diffusion equation. • We obtain the critical current by the linear stability analysis. • Our approach can be easily extended to other SMMs

Current-induced magnetic switching of a single molecule magnet on a spin valve

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiao [Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory, School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Zheng-Chuan, E-mail: wangzc@ucas.ac.cn [Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory, School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Zheng, Qing-Rong [Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory, School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); Zhu, Zheng-Gang [Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory, School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China); School of Electronics, Electric and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049 (China); Su, Gang, E-mail: gsu@ucas.ac.cn [Theoretical Condensed Matter Physics and Computational Materials Physics Laboratory, School of Physics, University of Chinese Academy of Sciences, Beijing 100049 (China)

2015-04-17

The current-induced magnetic switching of a single-molecule magnet (SMM) attached on the central region of a spin valve is explored, and the condition for the switching current is derived. Electrons flowing through the spin valve will interact with the SMM via the s–d exchange interaction, producing the spin accumulation that satisfies the spin diffusion equation. We further describe the spin motion of the SMM by a Heisenberg-like equation. Based on the linear stability analysis, we obtain the critical current from two coupled equations. The results of the critical current versus the external magnetic field indicate that one can manipulate the magnetic state of the SMM by an external magnetic field. - Highlights: • We theoretically study the current-induced magnetic switching of the SMM. • We describe the spin motion of the SMM by a Heisenberg-like equation. • We describe the spin accumulation by the spin diffusion equation. • We obtain the critical current by the linear stability analysis. • Our approach can be easily extended to other SMMs.

5-HT modulation of pain perception in humans.

Science.gov (United States)

Martin, Sarah L; Power, Andrea; Boyle, Yvonne; Anderson, Ian M; Silverdale, Monty A; Jones, Anthony K P

2017-10-01

Although there is clear evidence for the serotonergic regulation of descending control of pain in animals, little direct evidence exists in humans. The majority of our knowledge comes from the use of serotonin (5-HT)-modulating antidepressants as analgesics in the clinical management of chronic pain. Here, we have used an acute tryptophan depletion (ATD) to manipulate 5-HT function and examine its effects of ATD on heat pain threshold and tolerance, attentional manipulation of nociceptive processing and mood in human volunteers. Fifteen healthy participants received both ATD and balanced amino acid (BAL) drinks on two separate sessions in a double-blind cross-over design. Pain threshold and tolerance were determined 4 h post-drink via a heat thermode. Additional attention, distraction and temperature discrimination paradigms were completed using a laser-induced heat pain stimulus. Mood was assessed prior and throughout each session. Our investigation reported that the ATD lowered plasma TRP levels by 65.05 ± 7.29% and significantly reduced pain threshold and tolerance in response to the heat thermode. There was a direct correlation between the reduction in total plasma TRP levels and reduction in thermode temperature. In contrast, ATD showed no effect on laser-induced pain nor significant impact of the distraction-induced analgesia on pain perception but did reduce performance of the painful temperature discrimination task. Importantly, all findings were independent of any effects of ATD on mood. As far as we are aware, it is the first demonstration of 5-HT effects on pain perception which are not confounded by mood changes.

As time goes by: Oxytocin influences the subjective perception of time in a social context.

Science.gov (United States)

Colonnello, Valentina; Domes, Gregor; Heinrichs, Markus

2016-06-01

Time perception depends on an event's emotional relevance to the beholder; a subjective time dilation effect is associated with self-relevant, emotionally salient stimuli. Previous studies have revealed that oxytocin modulates the salience of social stimuli and attention to social cues. However, whether the oxytocin system is involved in human subjective time perception is unknown. The aim of the present study was to investigate whether increased oxytocin levels would induce a time dilation effect for self-relevant, positive social cues. In a double-blind, placebo-controlled, between-subject design, heterosexual men were administered intranasal oxytocin or placebo. After about 50min, participants completed a time-bisection task in which they estimated lengths of exposure to happy female faces (self-relevant positive stimuli, based on sexual orientation), emotionally neutral and negative female faces (control), and happy, neutral, and negative male faces (control). Oxytocin induced a subjective time dilation effect for happy female faces and a time compression effect for happy male faces. Our results provide evidence that oxytocin influences time perception, a primary form of human subjectivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Counselor Education and Title IX: Current Perceptions and Questions

Science.gov (United States)

Welfare, Laura E.; Wagstaff, Jennifer; Haynes, Jenna R.

2017-01-01

This national survey of counselor educator perceptions of the Title IX requirement to report student disclosures of gender-based discrimination revealed the need for greater clarity about faculty strategies for serving counseling program students while upholding the federal law. The authors describe the recent expansion of the requirements and…

Side effects associated with current and prospective antimigraine pharmacotherapies.

Science.gov (United States)

González-Hernández, Abimael; Marichal-Cancino, Bruno A; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

2018-01-01

Migraine is a neurovascular disorder. Current acute specific antimigraine pharmacotherapies target trigeminovascular 5-HT 1B/1D , 5-HT 1F and CGRP receptors but, unfortunately, they induce some cardiovascular and central side effects that lead to poor treatment adherence/compliance. Therefore, new antimigraine drugs are being explored. Areas covered: This review considers the adverse (or potential) side effects produced by current and prospective antimigraine drugs, including medication overuse headache (MOH) produced by ergots and triptans, the side effects observed in clinical trials for the new gepants and CGRP antibodies, and a section discussing the potential effects resulting from disruption of the cardiovascular CGRPergic neurotransmission. Expert opinion: The last decades have witnessed remarkable developments in antimigraine therapy, which includes acute (e.g. triptans) and prophylactic (e.g. β-adrenoceptor blockers) antimigraine drugs. Indeed, the triptans represent a considerable advance, but their side effects (including nausea, dizziness and coronary vasoconstriction) preclude some patients from using triptans. This has led to the development of the ditans (5-HT 1F receptor agonists), the gepants (CGRP receptor antagonists) and the monoclonal antibodies against CGRP or its receptor. The latter drugs represent a new hope in the antimigraine armamentarium, but as CGRP plays a role in cardiovascular homeostasis, the potential for adverse cardiovascular side effects remains latent.

Induced- and alternating-current electro-osmotic control of the diffusion layer growth in a microchannel-membrane interface device

Science.gov (United States)

Park, Sinwook; Yossifon, Gilad

2014-11-01

The passage of an electric current through an ionic permselective medium under an applied electric field is characterized by the formation of ionic concentration gradients, which result in regions of depleted and enriched ionic concentration at opposite ends of the medium. Induced-current electro-osmosis (ICEO) and alternating-current-electro-osmosis (ACEO) are shown to control the growth of the diffusion layer (DL) which, in turn, controls the diffusion limited ion transport through the microchannel-membrane system. We fabricated and tested devices made of a Nafion membrane connecting two opposite PDMS microchannels. An interdigitated electrode array was embedded within the microchannel with various distances from the microchannel-membrane interface. The induced ICEO (floating electrodes) / ACEO (active electrodes) vortices formed at the electrode array stir the fluid and thereby suppress the growth of the DL. The intensity of the ACEO vortices is controlled by either varying the voltage amplitude or the frequency, each having its own unique effect. Enhancement of the limiting current by on-demand control of the diffusion length is of importance in on-chip electro-dialysis, desalination and preconcentration of analytes.

Northeast Tennessee Educators' Perception of STEM Education Implementation

Science.gov (United States)

Turner, Kristin Beard

2013-01-01

A quantitative nonexperimental survey study was developed to investigate Northeast Tennessee K-8 educators' perceptions of STEM education. This study was an examination of current perceptions of STEM education. Perceived need, current implementation practices, access to STEM resources, definition of STEM, and the current condition of STEM in…

Wave-current induced erosion of cohesive riverbanks in northern Manitoba, Canada

Science.gov (United States)

Kimiaghalam, N.; Clark, S.; Ahmari, H.; Hunt, J.

2015-03-01

The field of cohesive soil erosion is still not fully understood, in large part due to the many soil parameters that affect cohesive soil erodibility. This study is focused on two channels, 2-Mile and 8-Mile channels in northern Manitoba, Canada, that were built to connect Lake Winnipeg with Playgreen Lake and Playgreen Lake with Kiskikittogisu Lake, respectively. The banks of the channels consist of clay rich soils and alluvial deposits of layered clay, silts and sands. The study of erosion at the sites is further complicated because the flow-induced erosion is combined with the effects of significant wave action due to the large fetch length on the adjacent lakes, particularly Lake Winnipeg that is the seventh largest lake in North America. The study included three main components: field measurements, laboratory experiments and numerical modelling. Field measurements consisted of soil sampling from the banks and bed of the channels, current measurements and water sampling. Grab soil samples were used to measure the essential physical and electrochemical properties of the riverbanks, and standard ASTM Shelby tube samples were used to estimate the critical shear stress and erodibility of the soil samples using an erosion measurement device (EMD). Water samples were taken to estimate the sediment concentration profile and also to monitor changes in sediment concentration along the channels over time. An Acoustic Doppler Current Profiler (ADCP) was used to collect bathymetry and current data, and two water level gauges have been installed to record water levels at the entrance and outlet of the channels. The MIKE 21 NSW model was used to simulate waves using historical winds and measured bathymetry of the channels and lakes. Finally, results from the wave numerical model, laboratory tests and current measurement were used to estimate the effect of each component on erodibility of the cohesive banks.

Wave-current induced erosion of cohesive riverbanks in northern Manitoba, Canada

Directory of Open Access Journals (Sweden)

N. Kimiaghalam

2015-03-01

Full Text Available The field of cohesive soil erosion is still not fully understood, in large part due to the many soil parameters that affect cohesive soil erodibility. This study is focused on two channels, 2-Mile and 8-Mile channels in northern Manitoba, Canada, that were built to connect Lake Winnipeg with Playgreen Lake and Playgreen Lake with Kiskikittogisu Lake, respectively. The banks of the channels consist of clay rich soils and alluvial deposits of layered clay, silts and sands. The study of erosion at the sites is further complicated because the flow-induced erosion is combined with the effects of significant wave action due to the large fetch length on the adjacent lakes, particularly Lake Winnipeg that is the seventh largest lake in North America. The study included three main components: field measurements, laboratory experiments and numerical modelling. Field measurements consisted of soil sampling from the banks and bed of the channels, current measurements and water sampling. Grab soil samples were used to measure the essential physical and electrochemical properties of the riverbanks, and standard ASTM Shelby tube samples were used to estimate the critical shear stress and erodibility of the soil samples using an erosion measurement device (EMD. Water samples were taken to estimate the sediment concentration profile and also to monitor changes in sediment concentration along the channels over time. An Acoustic Doppler Current Profiler (ADCP was used to collect bathymetry and current data, and two water level gauges have been installed to record water levels at the entrance and outlet of the channels. The MIKE 21 NSW model was used to simulate waves using historical winds and measured bathymetry of the channels and lakes. Finally, results from the wave numerical model, laboratory tests and current measurement were used to estimate the effect of each component on erodibility of the cohesive banks.

What is a typical rape? Effects of victim and participant gender in female and male rape perception

OpenAIRE

Anderson, Irina

2007-01-01

The study had three research aims: (1) to examine the current perception of female rape. Given recent changes in public awareness of female rape, it was predicted that respondents would conceptualise a typical female rape as an acquaintance rape rather than as the stranger rape stereotype; (2) to examine whether these perceptions differ according to respondents’ gender; (3) to examine the ‘cultural lag’ theory of male rape where it was hypothesised that if the public perception of male rape l...

Oscillatory phase dynamics in neural entrainment underpin illusory percepts of time.

Science.gov (United States)

Herrmann, Björn; Henry, Molly J; Grigutsch, Maren; Obleser, Jonas

2013-10-02

Neural oscillatory dynamics are a candidate mechanism to steer perception of time and temporal rate change. While oscillator models of time perception are strongly supported by behavioral evidence, a direct link to neural oscillations and oscillatory entrainment has not yet been provided. In addition, it has thus far remained unaddressed how context-induced illusory percepts of time are coded for in oscillator models of time perception. To investigate these questions, we used magnetoencephalography and examined the neural oscillatory dynamics that underpin pitch-induced illusory percepts of temporal rate change. Human participants listened to frequency-modulated sounds that varied over time in both modulation rate and pitch, and judged the direction of rate change (decrease vs increase). Our results demonstrate distinct neural mechanisms of rate perception: Modulation rate changes directly affected listeners' rate percept as well as the exact frequency of the neural oscillation. However, pitch-induced illusory rate changes were unrelated to the exact frequency of the neural responses. The rate change illusion was instead linked to changes in neural phase patterns, which allowed for single-trial decoding of percepts. That is, illusory underestimations or overestimations of perceived rate change were tightly coupled to increased intertrial phase coherence and changes in cerebro-acoustic phase lag. The results provide insight on how illusory percepts of time are coded for by neural oscillatory dynamics.

Principal Perceptions of the Effectiveness of University Educational Leadership Preparation and Professional Learning

Science.gov (United States)

Johnson, Arvin D.

2016-01-01

Principals and assistant principals currently serving in Florida and Georgia school districts were surveyed about their perceptions of university educational leadership preparation and professional learning. The results revealed that many principals and assistant principals agreed that university educational leadership preparation programs…

EFFECT OF DIRECTORS’ BURNOUT PERCEPTION ON TEAMWORK

Directory of Open Access Journals (Sweden)

Nezih Metin Ozmutaf

2017-09-01

Full Text Available The main objective of the research is determining the perceptions towards the effect of burnout of principals in educational institutions in Izmir province on team works. The survey form prepared intended for the research, a face to face survey method is applied between the dates October 2016 - May 2017 within the frame of 148 principals in 87 schools of Izmir province. Following the research, the propositions towards emotional breaking, relational breaking and performance have been collected under sole factor. It has been concluded that exhaustion affects the team works negatively in terms of the factor and the propositions within the scope of it. Moreover, it has been defined that the results in point do not show difference in terms of gender, educational status, employment period, employment period as a director, vocational stress perception and personality structure.

Terahertz electric field driven electric currents and ratchet effects in graphene

Energy Technology Data Exchange (ETDEWEB)

Ganichev, Sergey D.; Weiss, Dieter; Eroms, Jonathan [Terahertz Center, University of Regensburg (Germany)

2017-11-15

Terahertz field induced photocurrents in graphene were studied experimentally and by microscopic modeling. Currents were generated by cw and pulsed laser radiation in large area as well as small-size exfoliated graphene samples. We review general symmetry considerations leading to photocurrents depending on linear and circular polarized radiation and then present a number of situations where photocurrents were detected. Starting with the photon drag effect under oblique incidence, we proceed to the photogalvanic effect enhancement in the reststrahlen band of SiC and edge-generated currents in graphene. Ratchet effects were considered for in-plane magnetic fields and a structure inversion asymmetry as well as for graphene with non-symmetric patterned top gates. Lastly, we demonstrate that graphene can be used as a fast, broadband detector of terahertz radiation. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Attention to bodily sensations and symptom perception in individuals with idiopathic environmental intolerance

DEFF Research Database (Denmark)

Skovbjerg, Sine; Zachariae, Robert; Rasmussen, Alice

2010-01-01

Idiopathic environmental intolerance (IEI) is characterized by non-specific symptoms attributed to exposure to environmental odours or chemicals at levels below those known to induce adverse health effects. A clarification of whether psychological processes involved in sensory perceptions...

Transition from condensation-induced counter-current flow to dispersed flow

International Nuclear Information System (INIS)

Gale, J.; Tiselj, I.

2004-01-01

Model of transition from the horizontally stratified condensation-induced counter-current flow to slug flow has been analyzed with computer code WAHA and compared to the experimental data obtained in the steamline of the PMK2 test facility of Hungarian Atomic Energy Institute. The experiment was performed in the steamline initially filled with hot vapor that was gradually flooded with cold liquid. Successful simulation of the condensation-induced water hammer that follows the transition, requires accurate description of the horizontally stratified and slug flow regimes and criteria for transition between both flow regimes. Current version of the WAHA code, not verified for the condensation induced type of the water hammer, predicts the water-hammer pressure peak that exceeds 600 bar, while the measured pressure is p m = 170 ± 50 bar. Sensitivity analysis of the inter-phase exchange terms and transition conditions, pointed to the most important closure relations for heat, mass and momentum transfer. The main conclusion of the analysis is large uncertainty of the simulations: minor modification of the crucial correlations can lead to a severe water-hammer in one case, or to the 'calm' transient without pressure peaks in the other case. Large uncertainty is observed in experiments. The same simulation was performed also with RELAP5 code. However, no water hammer was predicted. (author)

Deficits in pain perception in borderline personality disorder: results from the thermal grill illusion.

Science.gov (United States)

Bekrater-Bodmann, Robin; Chung, Boo Young; Richter, Ingmarie; Wicking, Manon; Foell, Jens; Mancke, Falk; Schmahl, Christian; Flor, Herta

2015-10-01

It is well documented that borderline personality disorder (BPD) is characterized by reduced pain sensitivity, which might be related to nonsuicidal self-injury and dissociative experiences in patients with BPD. However, it remains an open question whether this insensitivity relies at least partly on altered sensory integration or on an altered evaluation of pain or a combination of both. In this study, we used the thermal grill illusion (TGI), describing a painful sensation induced by the application of alternating cold and warm nonnoxious stimuli, in patients with either current or remitted BPD as well as matched healthy controls. Two additional conditions, applying warm or cold temperatures only, served as control. We further assessed thermal perception, discrimination, and pain thresholds. We found significantly reduced heat and cold pain thresholds for the current BPD group, as well as reduced cold pain thresholds for the remitted BPD group, as compared with the HC group. Current BPD patients perceived a less-intense TGI in terms of induced pain and unpleasantness, while their general ability to perceive this kind of illusion seemed to be unaffected. Thermal grill illusion magnitude was negatively correlated with dissociation and traumatization only in the current BPD patients. These results indicate that higher-order pain perception is altered in current BPD, which seems to normalize after remission. We discuss these findings against the background of neurophysiological evidence for the TGI in general and reduced pain sensitivity in BPD and suggest a relationship to alterations in N-methyl-D-aspartate neurotransmission.

Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains.

Science.gov (United States)

Sabater, Carlos; Untiedt, Carlos; van Ruitenbeek, Jan M

2015-01-01

This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a 'Berry force'. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.

Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains

Directory of Open Access Journals (Sweden)

Carlos Sabater

2015-12-01

Full Text Available This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a ‘Berry force’. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.

Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study.

Science.gov (United States)

Santos, Michele Devido; Gagliardi, Rubens José; Mac-Kay, Ana Paula Machado Goyano; Boggio, Paulo Sergio; Lianza, Roberta; Fregni, Felipe

2013-01-01

Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. Prospective cohort study developed in a public university hospital. Nineteen patients with chronic aphasia received 10 transcranial direct current stimulation sessions lasting 20 minutes each on consecutive days, using a current of 2 mA. The anode was positioned over the supraorbital area and the cathode over the contralateral motor cortex. The following variables were analyzed before and after the 10 neuromodulation sessions: oral language comprehension, copying, dictation, reading, writing, naming and verbal fluency. There were no adverse effects in the study. We found statistically significant differences from before to after stimulation in relation to simple sentence comprehension (P = 0.034), naming (P = 0.041) and verbal fluency for names of animals (P = 0.038). Improved scores for performing these three tasks were seen after stimulation. We observed that excitability of the primary motor cortex through transcranial direct current stimulation was associated with effects on different aspects of language. This can contribute towards future testing in randomized controlled trials.

Quinine-induced tinnitus in rats.

Science.gov (United States)

Jastreboff, P J; Brennan, J F; Sasaki, C T

1991-10-01

Quinine ingestion reportedly induces tinnitus in humans. To expand our salicylate-based animal model of tinnitus, a series of conditioned suppression experiments was performed on 54 male-pigmented rats using quinine injections to induce tinnitus. Quinine induced changes in both the extent of suppression and recovery of licking, which followed a pattern that paralleled those produced after salicylate injections, and which may be interpreted as the result of tinnitus perception in animals. These changes depended on the dose and time schedule of quinine administration. Additionally, the calcium channel blocker, nimodipine, abolished the quinine-induced effect in a dose-dependent manner.

Suppressive and Enhancing Effects in Early Visual Cortex during Illusory Shape Perception: A Comment on Kok and de Lange (2014

Directory of Open Access Journals (Sweden)

Pieter Moors

2015-02-01

Full Text Available In a recent functional magnetic resonance imaging study, Kok and de Lange (2014 observed that BOLD activity for a Kanizsa illusory shape stimulus, in which pacmen-like inducers elicit an illusory shape percept, was either enhanced or suppressed relative to a nonillusory control configuration depending on whether the spatial profile of BOLD activity in early visual cortex was related to the illusory shape or the inducers, respectively. The authors argued that these findings fit well with the predictive coding framework, because top-down predictions related to the illusory shape are not met with bottom-up sensory input and hence the feedforward error signal is enhanced. Conversely, for the inducing elements, there is a match between top-down predictions and input, leading to a decrease in error. Rather than invoking predictive coding as the explanatory framework, the suppressive effect related to the inducers might be caused by neural adaptation to perceptually stable input due to the trial sequence used in the experiment.

Can the use of pulsed direct current induce oscillation in the applied pressure during spark plasma sintering?

International Nuclear Information System (INIS)

Salamon, David; Eriksson, Mirva; Nygren, Mats; Shen Zhijian

2012-01-01

The spark plasma sintering (SPS) process is known for its rapid densification of metals and ceramics. The mechanism behind this rapid densification has been discussed during the last few decades and is yet uncertain. During our SPS experiments we noticed oscillations in the applied pressure, related to a change in electric current. In this study, we investigated the effect of pulsed electrical current on the applied mechanical pressure and related changes in temperature. We eliminated the effect of sample shrinkage in the SPS setup and used a transparent quartz die allowing direct observation of the sample. We found that the use of pulsed direct electric current in our apparatus induces pressure oscillations with the amplitude depending on the current density. While sintering Ti samples we observed temperature oscillations resulting from pressure oscillations, which we attribute to magnetic forces generated within the SPS apparatus. The described current–pressure–temperature relations might increase understanding of the SPS process.

In-plane current induced domain wall nucleation and its stochasticity in perpendicular magnetic anisotropy Hall cross structures

International Nuclear Information System (INIS)

Sethi, P.; Murapaka, C.; Lim, G. J.; Lew, W. S.

2015-01-01

Hall cross structures in magnetic nanowires are commonly used for electrical detection of magnetization reversal in which a domain wall (DW) is conventionally nucleated by a local Oersted field. In this letter, we demonstrate DW nucleation in Co/Ni perpendicular magnetic anisotropy nanowire at the magnetic Hall cross junction. The DWs are nucleated by applying an in-plane pulsed current through the nanowire without the need of a local Oersted field. The change in Hall resistance, detected using anomalous Hall effect, is governed by the magnetic volume switched at the Hall junction, which can be tuned by varying the magnitude of the applied current density and pulse width. The nucleated DWs are driven simultaneously under the spin transfer torque effect when the applied current density is above a threshold. The possibility of multiple DW generation and variation in magnetic volume switched makes nucleation process stochastic in nature. The in-plane current induced stochastic nature of DW generation may find applications in random number generation

Current-induced damping of nanosized quantum moments in the presence of spin-orbit interaction

Science.gov (United States)

Mahfouzi, Farzad; Kioussis, Nicholas

2017-05-01

Motivated by the need to understand current-induced magnetization dynamics at the nanoscale, we have developed a formalism, within the framework of Keldysh Green function approach, to study the current-induced dynamics of a ferromagnetic (FM) nanoisland overlayer on a spin-orbit-coupling (SOC) Rashba plane. In contrast to the commonly employed classical micromagnetic LLG simulations the magnetic moments of the FM are treated quantum mechanically. We obtain the density matrix of the whole system consisting of conduction electrons entangled with the local magnetic moments and calculate the effective damping rate of the FM. We investigate two opposite limiting regimes of FM dynamics: (1) The precessional regime where the magnetic anisotropy energy (MAE) and precessional frequency are smaller than the exchange interactions and (2) the local spin-flip regime where the MAE and precessional frequency are comparable to the exchange interactions. In the former case, we show that due to the finite size of the FM domain, the "Gilbert damping" does not diverge in the ballistic electron transport regime, in sharp contrast to Kambersky's breathing Fermi surface theory for damping in metallic FMs. In the latter case, we show that above a critical bias the excited conduction electrons can switch the local spin moments resulting in demagnetization and reversal of the magnetization. Furthermore, our calculations show that the bias-induced antidamping efficiency in the local spin-flip regime is much higher than that in the rotational excitation regime.

Effects of Positive Affect on Risk Perceptions in Adolescence and Young Adulthood

Science.gov (United States)

Haase, Claudia M.; Silbereisen, Rainer K.

2011-01-01

Affective influences may play a key role in adolescent risk taking, but have rarely been studied. Using an audiovisual method of affect induction, two experimental studies examined the effect of positive affect on risk perceptions in adolescence and young adulthood. Outcomes were risk perceptions regarding drinking alcohol, smoking a cigarette,…

Circulating persistent current and induced magnetic field in a fractal network

Energy Technology Data Exchange (ETDEWEB)

Saha, Srilekha [Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata 700 064 (India); Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in [Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700 108 (India); Karmakar, S.N. [Condensed Matter Physics Division, Saha Institute of Nuclear Physics, Sector-I, Block-AF, Bidhannagar, Kolkata 700 064 (India)

2016-04-29

We present the overall conductance as well as the circulating currents in individual loops of a Sierpinski gasket (SPG) as we apply bias voltage via the side attached electrodes. SPG being a self-similar structure, its manifestation on loop currents and magnetic fields is examined in various generations of this fractal and it has been observed that for a given configuration of the electrodes, the physical quantities exhibit certain regularity as we go from one generation to another. Also a notable feature is the introduction of anisotropy in hopping causes an increase in magnitude of overall transport current. These features are a subject of interest in this article. - Highlights: • Voltage driven circular current is analyzed in a fractal network. • Current induced magnetic field is strong enough to flip a spin. • Anisotropy in hopping enhances overall transport current.

The Joint Effect of Relationship Perceptions, Loyalty Program and Direct Mailing on Customer Share Development

NARCIS (Netherlands)

P.C. Verhoef (Peter)

2002-01-01

textabstractIn this paper, we examine the effect of relationship perceptions and relationship marketing instruments on customer share development. We also study the interaction effect of these instruments with behavioral loyalty and relationship perceptions. This study is

A comprehensive model of audiovisual perception: both percept and temporal dynamics.

Directory of Open Access Journals (Sweden)

Patricia Besson

Full Text Available The sparse information captured by the sensory systems is used by the brain to apprehend the environment, for example, to spatially locate the source of audiovisual stimuli. This is an ill-posed inverse problem whose inherent uncertainty can be solved by jointly processing the information, as well as introducing constraints during this process, on the way this multisensory information is handled. This process and its result--the percept--depend on the contextual conditions perception takes place in. To date, perception has been investigated and modeled on the basis of either one of two of its dimensions: the percept or the temporal dynamics of the process. Here, we extend our previously proposed audiovisual perception model to predict both these dimensions to capture the phenomenon as a whole. Starting from a behavioral analysis, we use a data-driven approach to elicit a bayesian network which infers the different percepts and dynamics of the process. Context-specific independence analyses enable us to use the model's structure to directly explore how different contexts affect the way subjects handle the same available information. Hence, we establish that, while the percepts yielded by a unisensory stimulus or by the non-fusion of multisensory stimuli may be similar, they result from different processes, as shown by their differing temporal dynamics. Moreover, our model predicts the impact of bottom-up (stimulus driven factors as well as of top-down factors (induced by instruction manipulation on both the perception process and the percept itself.

Facilitating Effects of Emotion on the Perception of Biological Motion: Evidence for a Happiness Superiority Effect.

Science.gov (United States)

Lee, Hannah; Kim, Jejoong

2017-06-01

It has been reported that visual perception can be influenced not only by the physical features of a stimulus but also by the emotional valence of the stimulus, even without explicit emotion recognition. Some previous studies reported an anger superiority effect while others found a happiness superiority effect during visual perception. It thus remains unclear as to which emotion is more influential. In the present study, we conducted two experiments using biological motion (BM) stimuli to examine whether emotional valence of the stimuli would affect BM perception; and if so, whether a specific type of emotion is associated with a superiority effect. Point-light walkers with three emotion types (anger, happiness, and neutral) were used, and the threshold to detect BM within noise was measured in Experiment 1. Participants showed higher performance in detecting happy walkers compared with the angry and neutral walkers. Follow-up motion velocity analysis revealed that physical difference among the stimuli was not the main factor causing the effect. The results of the emotion recognition task in Experiment 2 also showed a happiness superiority effect, as in Experiment 1. These results show that emotional valence (happiness) of the stimuli can facilitate the processing of BM.

Muon track induced current measurements in semi-insulating GaAs

Energy Technology Data Exchange (ETDEWEB)

Eshchenko, D.G., E-mail: dimitry.eshchenko@psi.c [Physik-Institut der Universitaet Zuerich, CH-8057 Zuerich (Switzerland); Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Storchak, V.G. [Russian Research Centre ' Kurchatov Institute' , Kurchatov Sq. 1, Moscow 123182 (Russian Federation); Cottrell, S.P. [ISIS Facility, Rutherford Appleton Laboratory, Oxfordshire OX11 OQX (United Kingdom)

2009-04-15

We report on preliminary muon-track-induced current measurements in semi-insulating (SI-) GaAs. At T=70K, after simultaneous treatment of the sample by muon irradiation and a strong electric field (a square wave with |E|>10kV/cm and the polarity changed every 1/(50) s) for approximately 2 h, the sample is transferred to a metastable-like state which is characterized by increased life-times for non-equilibrium electrons and holes. The sample can be returned to the original state by heating up to 250 K. Our results for SI-GaAs suggest a muon-track-induced electric-field-assisted neutralization process for the deep traps.

Three-dimensional wave-induced current model equations and radiation stresses

Science.gov (United States)

Xia, Hua-yong

2017-08-01

After the approach by Mellor (2003, 2008), the present paper reports on a repeated effort to derive the equations for three-dimensional wave-induced current. Via the vertical momentum equation and a proper coordinate transformation, the phase-averaged wave dynamic pressure is well treated, and a continuous and depth-dependent radiation stress tensor, rather than the controversial delta Dirac function at the surface shown in Mellor (2008), is provided. Besides, a phase-averaged vertical momentum flux over a sloping bottom is introduced. All the inconsistencies in Mellor (2003, 2008), pointed out by Ardhuin et al. (2008) and Bennis and Ardhuin (2011), are overcome in the presently revised equations. In a test case with a sloping sea bed, as shown in Ardhuin et al. (2008), the wave-driving forces derived in the present equations are in good balance, and no spurious vertical circulation occurs outside the surf zone, indicating that Airy's wave theory and the approach of Mellor (2003, 2008) are applicable for the derivation of the wave-induced current model.

Analysis of induced electrical currents from magnetic field coupling inside implantable neurostimulator leads

Directory of Open Access Journals (Sweden)

Seidman Seth J

2011-10-01

Full Text Available Abstract Background Over the last decade, the number of neurostimulator systems implanted in patients has been rapidly growing. Nearly 50, 000 neurostimulators are implanted worldwide annually. The most common type of implantable neurostimulators is indicated for pain relief. At the same time, commercial use of other electromagnetic technologies is expanding, making electromagnetic interference (EMI of neurostimulator function an issue of concern. Typically reported sources of neurostimulator EMI include security systems, metal detectors and wireless equipment. When near such sources, patients with implanted neurostimulators have reported adverse events such as shock, pain, and increased stimulation. In recent in vitro studies, radio frequency identification (RFID technology has been shown to inhibit the stimulation pulse of an implantable neurostimulator system during low frequency exposure at close distances. This could potentially be due to induced electrical currents inside the implantable neurostimulator leads that are caused by magnetic field coupling from the low frequency identification system. Methods To systematically address the concerns posed by EMI, we developed a test platform to assess the interference from coupled magnetic fields on implantable neurostimulator systems. To measure interference, we recorded the output of one implantable neurostimulator, programmed for best therapy threshold settings, when in close proximity to an operating low frequency RFID emitter. The output contained electrical potentials from the neurostimulator system and those induced by EMI from the RFID emitter. We also recorded the output of the same neurostimulator system programmed for best therapy threshold settings without RFID interference. Using the Spatially Extended Nonlinear Node (SENN model, we compared threshold factors of spinal cord fiber excitation for both recorded outputs. Results The electric current induced by low frequency RFID emitter

Dual Aharonov-Casher effect and persistent dipole current

International Nuclear Information System (INIS)

Yi, J.; Jeon, G.S.; Choi, M.Y.

1995-01-01

An electric dipole moving in a magnetic field acquires a nontrivial quantum phase in the appropriate configuration. It is shown that this phase is manifested by the persistent dipole current induced on a ring pierced by a line of magnetic monopoles. Such a current depends on the statistics of the dipoles, which may have interesting implications for experiments. It is also pointed out that the dipole current cannot be self-sustained

Effects of the ohmic current on collective scattering spectra

International Nuclear Information System (INIS)

Castiglioni, S.; Lontano, M.; Tartari, U.

1993-01-01

A numerical and analytical study of the modifications induced in the collective scattering spectra by the ohmic current governing the equilibrium magnetic configuration in toroidal plasmas is presented. The spectral density function is calculated assuming equilibrium distributions for the (bulk and impurity) ion species and a Spitzer-like distribution to describe the response of the electrons to the applied DC electric field. As expected, the spectral asymmetries can be non-negligibly enhanced in the region of the ion-acoustic frequency. They reach their maxima for tangential scattering geometries, where the magnetic effects on the spectra are negligible. This justifies the assumption of the non-magnetized spectra. A theoretically motivated potential is shown to exist for a more detailed experimental investigation of the feasibility of current-density measurements in ohmic plasmas, based on collective scattering. (author)

Effect of screening current induced pair breaking on magnetization of superconducting lead nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Yashwant, G.; Prajapat, C.L. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085 (India); Jayakumar, O.D. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085 (India); Singh, M.R.; Gupta, S.K. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085 (India); Tyagi, A.K. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085 (India); Ravikumar, G. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085 (India)], E-mail: gurazada@barc.gov.in

2008-06-15

Magnetization measurements on lead nanoparticles in the size range 35-45 nm are presented. It is shown that the critical fields in these nanoparticles are enhanced significantly above their bulk values with temperature dependence also distinct from that of bulk. The observed 'type II' like shape of the magnetization curves is explained on the basis of the Ginzburg-Landau phenomenology by invoking the pair breaking effect of the London screening currents, which makes the effective penetration depth an increasing function of the field. The temperature dependence of critical field is found to be consistent with our explanation.

Effects of auditory information on self-motion perception during simultaneous presentation of visual shearing motion

Science.gov (United States)

Tanahashi, Shigehito; Ashihara, Kaoru; Ujike, Hiroyasu

2015-01-01

Recent studies have found that self-motion perception induced by simultaneous presentation of visual and auditory motion is facilitated when the directions of visual and auditory motion stimuli are identical. They did not, however, examine possible contributions of auditory motion information for determining direction of self-motion perception. To examine this, a visual stimulus projected on a hemisphere screen and an auditory stimulus presented through headphones were presented separately or simultaneously, depending on experimental conditions. The participant continuously indicated the direction and strength of self-motion during the 130-s experimental trial. When the visual stimulus with a horizontal shearing rotation and the auditory stimulus with a horizontal one-directional rotation were presented simultaneously, the duration and strength of self-motion perceived in the opposite direction of the auditory rotation stimulus were significantly longer and stronger than those perceived in the same direction of the auditory rotation stimulus. However, the auditory stimulus alone could not sufficiently induce self-motion perception, and if it did, its direction was not consistent within each experimental trial. We concluded that auditory motion information can determine perceived direction of self-motion during simultaneous presentation of visual and auditory motion information, at least when visual stimuli moved in opposing directions (around the yaw-axis). We speculate that the contribution of auditory information depends on the plausibility and information balance of visual and auditory information. PMID:26113828

Manifesto for the current understanding and management of traumatic brain injury-induced hypopituitarism.

LENUS (Irish Health Repository)

Tanriverdi, F

2011-01-01

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here.

Manifesto for the current understanding and management of traumatic brain injury-induced hypopituitarism

DEFF Research Database (Denmark)

Tanriverdi, F; Agha, A; Aimaretti, G

2011-01-01

Traumatic brain injury (TBI)-induced hypopituitarism remains a relevant medical problem, because it may affect a significant proportion of the population. In the last decade important studies have been published investigating pituitary dysfunction after TBI. Recently, a group of experts gathered...... and revisited the topic of TBI-induced hypopituitarism. During the 2-day meeting, the main issues of this topic were presented and discussed, and current understanding and management of TBI-induced hypopituitarism are summarized here....

Eddy Effects in the General Circulation, Spanning Mean Currents, Mesoscale Eddies, and Topographic Generation, Including Submesoscale Nests

Science.gov (United States)

2014-09-30

alongshore winds favoring upwelling circulation. As for the other EBUS (e.g., Humboldt, Benguela, and Canary Currents ), equatorward winds drive...Eddy Effects in the General Circulation, Spanning Mean Currents , Mesoscale Eddies, and Topographic Generation, Including Submesoscale Nests...environments OBJECTIVES The central scientific questions are how the eddies control the persistent currents by their eddy-induced momentum and buoyancy fluxes

Effects of Production Training and Perception Training on Lexical Tone Perception--Are the Effects Domain General or Domain Specific?

Science.gov (United States)

Lu, Shuang

2013-01-01

The relationship between speech perception and production has been debated for a long time. The Motor Theory of speech perception (Liberman et al., 1989) claims that perceiving speech is identifying the intended articulatory gestures rather than perceiving the sound patterns. It seems to suggest that speech production precedes speech perception,…

Thermally induced spin-dependent current based on Zigzag Germanene Nanoribbons

Science.gov (United States)

Majidi, Danial; Faez, Rahim

2017-02-01

In this paper, using first principle calculation and non-equilibrium Green's function, the thermally induced spin current in Hydrogen terminated Zigzag-edge Germanene Nanoribbon (ZGeNR-H) is investigated. In this model, because of the difference between the source and the drain temperature of ZGeNR device, the spin up and spin down currents flow in the opposite direction with two different threshold temperatures (Tth). Hence, a pure spin polarized current which belongs to spin down is obtained. It is shown that, for temperatures above the threshold temperature spin down current increases with the increasing temperature up to 75 K and then decreases. But spin up current rises steadily and in the high temperature we can obtain polarized spin up current. In addition, we show an acceptable spin current around the room temperature for ZGeNR. The transmission peaks in ZGeNR which are closer to the Fermi level rather than Zigzag Graphene Nanoribbon (ZGNRS) which causes ZGeNR to have spin current at higher temperatures. Finally, it is indicated that by tuning the back gate voltage, the spin current can be completely modulated and polarized. Simulation results verify the Zigzag Germanene Nanoribbon as a promising candidate for spin caloritronics devices, which can be applied in future low power consumption technology.

Principals' Perceptions of Politics

Science.gov (United States)

Tooms, Autumn K.; Kretovics, Mark A.; Smialek, Charles A.

2007-01-01

This study is an effort to examine principals' perceptions of workplace politics and its influence on their productivity and efficacy. A survey was used to explore the perceptions of current school administrators with regard to workplace politics. The instrument was disseminated to principals serving public schools in one Midwestern state in the…

Resistance and sheet resistance measurements using electron beam induced current

International Nuclear Information System (INIS)

Czerwinski, A.; Pluska, M.; Ratajczak, J.; Szerling, A.; KaPtcki, J.

2006-01-01

A method for measurement of spatially uniform or nonuniform resistance in layers and strips, based on electron beam induced current (EBIC) technique, is described. High electron beam currents are used so that the overall resistance of the measurement circuit affects the EBIC signal. During the evaluation, the electron beam is scanned along the measured object, whose load resistance varies with the distance. The variation is compensated by an adjustable resistance within an external circuit. The method has been experimentally deployed for sheet resistance determination of buried regions of lateral confinements in semiconductor laser heterostructures manufactured by molecular beam epitaxy

Teachers' Perceptions of Leadership Effectiveness Based on Gender

Science.gov (United States)

Alagbada-Ekekhomen, Gloria O.

2013-01-01

This research examined teachers' perceptions of effective leadership skills and any significant differences of teachers' views of an administrator's success based on the leader's gender. A review of studies examining differences in the leadership behaviors of men and women did not provide conclusive results. The three hypotheses based on the…

Audiovisual perception in amblyopia: A review and synthesis.

Science.gov (United States)

Richards, Michael D; Goltz, Herbert C; Wong, Agnes M F

2018-05-17

Amblyopia is a common developmental sensory disorder that has been extensively and systematically investigated as a unisensory visual impairment. However, its effects are increasingly recognized to extend beyond vision to the multisensory domain. Indeed, amblyopia is associated with altered cross-modal interactions in audiovisual temporal perception, audiovisual spatial perception, and audiovisual speech perception. Furthermore, although the visual impairment in amblyopia is typically unilateral, the multisensory abnormalities tend to persist even when viewing with both eyes. Knowledge of the extent and mechanisms of the audiovisual impairments in amblyopia, however, remains in its infancy. This work aims to review our current understanding of audiovisual processing and integration deficits in amblyopia, and considers the possible mechanisms underlying these abnormalities. Copyright © 2018. Published by Elsevier Ltd.

Intrinsic Motivation, Self-Perception, and Their Effects on Black Urban Elementary Students.

Science.gov (United States)

Marchant, Gregory J.

This study examined the effects of specific motivational dimensions and self-perceptions of a group of 47 urban black fourth and fifth grade students on attendance and academic achievement. Each student's responses to a measure of intrinsic and extrinsic motivation and a self-perception inventory were compared to each other and to his or her…

Current advances in orthodontic pain

Science.gov (United States)

Long, Hu; Wang, Yan; Jian, Fan; Liao, Li-Na; Yang, Xin; Lai, Wen-Li

2016-01-01

Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway—periaqueductal grey and dorsal raphe—has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future. PMID:27341389

Chemotherapy-induced peripheral neuropathy: an update on the current understanding.

Science.gov (United States)

Addington, James; Freimer, Miriam

2016-01-01

Chemotherapy-induced peripheral neuropathy is a common side effect of selected chemotherapeutic agents. Previous work has suggested that patients often under report the symptoms of chemotherapy-induced peripheral neuropathy and physicians fail to recognize the presence of such symptoms in a timely fashion. The precise pathophysiology that underlies chemotherapy-induced peripheral neuropathy, in both the acute and the chronic phase, remains complex and appears to be medication specific. Recent work has begun to demonstrate and further clarify potential pathophysiological processes that predispose and, ultimately, lead to the development of chemotherapy-induced peripheral neuropathy. There is increasing evidence that the pathway to neuropathy varies with each agent. With a clearer understanding of how these agents affect the peripheral nervous system, more targeted treatments can be developed in order to optimize treatment and prevent long-term side effects.

The effects of neutral inertia on ionospheric currents in the high-latitude thermosphere following a geomagnetic storm

International Nuclear Information System (INIS)

Deng, W.; Killeen, T.L.; Burns, A.G.; Roble, R.G.; Slavin, J.A.; Wharton, L.E.

1993-01-01

The authors extend previous work with a National Center for Atmospheric Research (NCAR) thermosphere/ionosphere general circulation model (TIGCM), to study dynamo effects in the high latitude thermosphere. Ionospheric convection can drive neutral currents in much the same pattern by means of ion drag reactions. It has been observed that ion currents established during magnetic storms can induce neutral currents which persist for hours after the end of the storm. Model results have shown that such currents can account for up to 80 percent of the Hall currents in the period immediately following storms. Here this previous work is extended and compared with experimental observations. The authors simulate time dependent Hall currents, field-aligned currents, and electrical power fluxes coupling the magnetosphere and ionosphere. They discuss their results in terms of a loaded magnetosphere, which accounts for the fact that the neutral currents can also induce currents and electric fields in the ionosphere

Risk Perceptions in Diabetic Patients Who Have Experienced Adverse Events

DEFF Research Database (Denmark)

Sachs, Mikkel Lindskov; Sporrong, Sofia Kälvemark; Colding-Jørgensen, Morten

2017-01-01

as part of a benefit-risk assessment. However, the degree of heterogeneity of the patient population is critical for how accurately they can be represented by individuals. OBJECTIVES: This study aims to explore patients' risk perception of rare, serious adverse effects of medicines with regard to blood......, perceptions of the terms rare and serious, and overall levels of risk aversion. A thematic analysis of the interviews, including a consensus discussion, was carried out. RESULTS: Interestingly, respondents rarely made a clear distinction between medicines-induced AEs and complications related to disease...... focused on common and less serious AEs, thus disregarding rare and more serious events. CONCLUSION: The study suggests that experience of AEs, related to either medicines or disease, constitutes an important factor of patient risk perception. We therefore propose that serious adverse experiences should...

Anti-fatigue effect of percutaneous stimulation of the hepatic region by mid-frequency pulse current in different diadynamic cycles in soldiers with exercise-induced fatigue

Directory of Open Access Journals (Sweden)

Peng-yi DAI

2012-01-01

Full Text Available Objective  To investigate the anti-fatigue effect of percutaneous stimulation of the hepatic region with the mid-frequency pulse current in different diadynamic cycles in exercise-induced fatigued soldiers. Methods  One hundred twenty healthy PLA recruits who did not have physical exercise were randomly divided into four groups with thirty ones in each: control, stimulation group A, stimulation group B, and stimulation group C. All the subjects of four groups were ordered intensive training (exercise from Monday to Saturday, with rest on Sunday for five weeks to establish the exercise-induced fatigue model. Each day after the exercise, the recruits of stimulation groups A, B, and C were treated immediately with mid-frequency (1204Hz, current intensity ≤80mA stimulation to the hepatic region with diadynamic cycles of 0.5, 1, and 2 seconds, respectively. No pulse current stimulation was given in the control group. Venous blood was collected before breakfast on Sundays to measure the fasting plasma glucose (FPG and blood lactate (LAC contents, and liver function was determined by determination of alanine aminotransferase (ALT, aspartate aminotransferase (AST, and lactate dehydrogenase (LDH. The 3000-m running performance of the recruits in each group was recorded on the same day. Results  There was no significant difference between the four groups in terms of the FPG level at the end of the first week (P>0.05. At the end of the third and fifth weeks, the FPG level was significantly higher in the three stimulation groups than in the control group (PPP>0.05. At the end of the first, third, and fifth weeks, the ALT, AST, LDH, and LAC levels were significantly lower in every stimulation group than in the control group (PPPPP>0.05. At the end of the first week, there was no significant difference in 3000-m running performance (P>0.05 between the 4 groups. At the end of the third and fifth weeks, the 3000-m running performance was significantly

Computer circuit analysis of induced currents in the MFTF-B magnet system

International Nuclear Information System (INIS)

Magnuson, G.D.; Woods, E.L.

1981-01-01

An analysis was made of the induced current behavior of the MFTF-B magnet system. Although the magnet system consists of 22 coils, because of its symmetry we considered only 11 coils in the analysis. Various combinations of the coils were dumped either singly or in groups, with the current behavior in all magnets calculated as a function of time after initiation of the dump

On geomagnetically-induced currents in the Finnish 400 kV power system by an auroral electrojet current

International Nuclear Information System (INIS)

Pirjola, R.; Viljanen, A.

1989-01-01

The auroral electrojet current flowing in the ionosphere is modeled by a horizontal east-west line current of infinite length. The earth is described by a simple two-layer model. An expression for the earth-surface electric field, which is thus connected with a geomagnetic disturbance in and near the auroral zone, is given. This electric field is considered as external from the viewpoint of the Finnish 400 kV power system, and the resulting geomagnetically-induced currents (GICs) in the system are computed. In the north, i.e. near the electrojet, GICs may have values even in the order of hundreds of amperes. A comparison to GICs produced by an equivalent spatially-constant external electric field is demonstrated. Sometimes the location of the electrojet is further south. This possibility is studied by letting the line current have several different locations above the Finnish power grid

Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

Science.gov (United States)

Kwon, Yong Hyun; Jang, Sung Ho

2012-01-01

We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation. PMID:25624815

Radiation induced ion currents in vacuum due to residual He and H, and their expected effect on insulating surfaces

International Nuclear Information System (INIS)

Hodgson, E.R.; Morono, A.; Gonzalez de Vicente, S.M.

2006-01-01

Ceramic insulators and windows in ITER will be subjected to bombardment by energetic hydrogen isotopes and helium as a consequence of ionization of the residual gas by gamma radiation and acceleration of the ions by the local electric fields. Most of the energy carried by these particles will be deposited at or very near the surface giving rise to possible electrical and optical degradation. Severe surface electrical degradation has recently been observed when oxide materials are implanted to low doses (10 15 ions/cm 2 ) with protons and alpha particles at temperatures between 50 and 450 o C. In order to estimate the relevance to fusion applications and hence the lifetime of ceramic insulators in ITER it is necessary to quantify possible ion currents generated in the residual gas by measuring radiation induced electrical conductivity for hydrogen isotopes and helium gases at low pressures and then perform experiments in which ceramic candidate materials are subjected to ion bombardment at representative currents and energies. To determine the magnitude of radiation generated ion currents, experiments have been carried out in a special gas chamber mounted in the beam line of a 2 MeV Van de Graaff electron accelerator, with the gases being irradiated through an 0.05 x 10 -3 m thick aluminium window with 1.8 MeV electrons. A guarded volume was defined between two parallel square copper plate electrodes separated by 1.5 x 10 -2 m. The experimental set-up permitted an electric field to be applied to the irradiated volume of gas, and the electric current flowing through the ionized gas to be measured. For these experiments the radiation beam was perpendicular to the electric field direction. In this way radiation induced conductivity for helium and hydrogen has been measured at pressures between about 1000 and 10 -3 mbar (10 -5 to 10 -1 Pa), radiation dose rates of 30 Gy/s and applied voltages up to 1500 volts. The radiation induced electrical currents for low pressure

Parietal theta burst TMS: Functional fractionation observed during bistable perception not evident in attention tasks.

Science.gov (United States)

Schauer, Georg; Kanai, Ryota; Brascamp, Jan W

2016-02-01

When visual input is ambiguous, perception spontaneously alternates between interpretations: bistable perception. Studies have identified two distinct sites near the right intraparietal sulcus where inhibitory transcranial magnetic stimulation (TMS) affects the frequency of occurrence of these alternations, but strikingly with opposite directions of effect for the two sites. Lesion and TMS studies on spatial and sustained attention have also indicated a parcellation of right parietal cortex, into areas serving distinct attentional functions. We used the exact TMS procedure previously employed to affect bistable perception, yet measured its effect on spatial and sustained attention tasks. Although there was a trend for TMS to affect performance, trends were consistently similar for both parietal sites, with no indication of opposite effects. We interpret this as signifying that the previously observed parietal fractionation of function regarding the perception of ambiguous stimuli is not due to TMS-induced modification of spatial or sustained attention. Copyright © 2016 Elsevier Inc. All rights reserved.

Sensorimotor influences on speech perception in infancy.

Science.gov (United States)

Bruderer, Alison G; Danielson, D Kyle; Kandhadai, Padmapriya; Werker, Janet F

2015-11-03

The influence of speech production on speech perception is well established in adults. However, because adults have a long history of both perceiving and producing speech, the extent to which the perception-production linkage is due to experience is unknown. We addressed this issue by asking whether articulatory configurations can influence infants' speech perception performance. To eliminate influences from specific linguistic experience, we studied preverbal, 6-mo-old infants and tested the discrimination of a nonnative, and hence never-before-experienced, speech sound distinction. In three experimental studies, we used teething toys to control the position and movement of the tongue tip while the infants listened to the speech sounds. Using ultrasound imaging technology, we verified that the teething toys consistently and effectively constrained the movement and positioning of infants' tongues. With a looking-time procedure, we found that temporarily restraining infants' articulators impeded their discrimination of a nonnative consonant contrast but only when the relevant articulator was selectively restrained to prevent the movements associated with producing those sounds. Our results provide striking evidence that even before infants speak their first words and without specific listening experience, sensorimotor information from the articulators influences speech perception. These results transform theories of speech perception by suggesting that even at the initial stages of development, oral-motor movements influence speech sound discrimination. Moreover, an experimentally induced "impairment" in articulator movement can compromise speech perception performance, raising the question of whether long-term oral-motor impairments may impact perceptual development.

Effects of fitness and self-confidence on time perception during exertion

Directory of Open Access Journals (Sweden)

2015-09-01

Full Text Available Aims: Human physical and psychological features influence perceptions of the environment during activity. If during exercise an individual over-estimates time, they may interpret this as spending longer than necessary under a potentially aversive state of exertion. This may in turn decrease one’s sense of exercise success and tendency to persevere with exercise. We tested if experimentally manipulating sense of exercise self-efficacy would affect time perception during standardised physical exertion. Method: Exercise Self-Efficacy (ESE of 18 -73 year olds (N=51 was measured before and after an exercise challenge of moderate intensity. Height, weight and body fat composition were measured before participants were randomly allocated to one of three groups. After a 4-minute treadmill fitness test, participants were presented with either bogus feedback about their performance (positive or negative or no feedback (control. Before and during exercise, participants estimated a prescribed 2-minute time interval. Ratings of perceived exertion were also measured periodically. Results: Feedback on performance had no significant effect on time perception, even when controlling for individual exertion level. Reported ESE was also unaffected by whether someone received positive, negative or no feedback. Age was again found to be significantly correlated with VO2max, r(51 = .62, p < .001, but in contrast to prior findings, estimates of general fitness such as VO2max, BMI and waist circumference were unrelated to changes in time perception due to exertion. Conclusions: These findings failed to support prior findings and anecdotal evidence suggesting that exertion might alter one’s perception of time. We also failed to find any support for effects on ESE when participants were given explicit performance feedback. Finally, participants’ physical characteristics appear to be unrelated to time perception whilst exercising at moderate intensity.

Current approaches to prevent NSAID-induced gastropathy – COX selectivity and beyond

Science.gov (United States)

Becker, Jan C; Domschke, Wolfram; Pohle, Thorsten

2004-01-01

Gastrointestinal (GI) toxicity associated with nonsteroidal anti-inflammatory drugs (NSAIDs) is still an important medical and socio-economic problem – despite recent pharmaceutical advances. To prevent NSAID-induced gastropathy, three strategies are followed in clinical routine: (i) coprescription of a gastroprotective drug, (ii) use of selective COX-2 inhibitors, and (iii) eradication of Helicobacter pylori. Proton pump inhibitors are the comedication of choice as they effectively reduce gastrointestinal adverse events of NSAIDs and are safe even in long-term use. Co-medication with vitamin C has only been little studied in the prevention of NSAID-induced gastropathy. Apart from scavenging free radicals it is able to induce haeme-oxgenase 1 in gastric cells, a protective enzyme with antioxidant and vasodilative properties. Final results of the celecoxib outcome study (CLASS study) attenuated the initial enthusiasm about the GI safety of selective COX-2 inhibitors, especially in patients concomitantly taking aspirin for cardiovascular prophylaxis. Helicobacter pylori increases the risk for ulcers particularly in NSAID-naive patients and therefore eradication is recommended prior to long-term NSAID therapy at least in patients at high risk. New classes of COX-inhibitors are currently evaluated in clinical studies with very promising results: NSAIDs combined with a nitric oxide releasing moiety (NO-NSAID) and dual inhibitors of COX and 5-LOX. These drugs offer extended anti-inflammatory potency while sparing gastric mucosa. PMID:15563357

Evaluating the loudness of phantom auditory perception (tinnitus) in rats.

Science.gov (United States)

Jastreboff, P J; Brennan, J F

1994-01-01

Using our behavioral paradigm for evaluating tinnitus, the loudness of salicylate-induced tinnitus was evaluated in 144 rats by comparing their behavioral responses induced by different doses of salicylate to those induced by different intensities of a continuous reference tone mimicking tinnitus. Group differences in resistance to extinction were linearly related to salicylate dose and, at moderate intensities, to the reference tone as well. Comparison of regression equations for salicylate versus tone effects permitted estimation of the loudness of salicylate-induced tinnitus. These results extend the animal model of tinnitus and provide evidence that the loudness of phantom auditory perception is expressed through observable behavior, can be evaluated, and its changes detected.