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Sample records for 2pi effective action

  1. I=2 pi-pi Scattering from Fully-Dynamical Mixed-Action Lattice QCD

    SciTech Connect

    Silas R. Beane; Paulo F. Bedaque; Kostas Orginos; Martin J. Savage

    2005-06-11

    We compute the I=2 {pi}{pi} scattering length at pion masses of m{sub {pi}} = 294, 348 and 484 MeV in fully-dynamical lattice QCD using Luescher's finite-volume method. The calculation is performed with domain-wall valence-quark propagators on asqtad-improved MILC configurations with staggered sea quarks. Chiral perturbation theory is used to perform the extrapolation of the scattering length from lattice quark masses down to the physical value, and we find m{sub {pi}}a{sub 2} = -0.0426 {+-} 0.0006 {+-} 0.0003 {+-} 0.0018, in good agreement with experiment. The I = 2 {pi}{pi} scattering phase shift is calculated to be {delta} = -43 {+-} 10 {+-} 5 degrees at |p| {approx} 544 MeV for m{pi} {approx} 484 MeV.

  2. Symmetry-improved 2PI approach to the Goldstone-boson IR problem of the SM effective potential

    NASA Astrophysics Data System (ADS)

    Pilaftsis, Apostolos; Teresi, Daniele

    2016-05-01

    The effective potential of the Standard Model (SM), from three loop order and higher, suffers from infrared (IR) divergences arising from quantum effects due to massless would-be Goldstone bosons associated with the longitudinal polarizations of the W± and Z bosons. Such IR pathologies also hinder accurate evaluation of the two-loop threshold corrections to electroweak quantities, such as the vacuum expectation value of the Higgs field. However, these divergences are an artifact of perturbation theory, and therefore need to be consistently resummed in order to obtain an IR-safe effective potential. The so-called Two-Particle-Irreducible (2PI) effective action provides a rigorous framework to consistently perform such resummations, without the need to resort to ad hoc subtractions or running into the risk of over-counting contributions. By considering the recently proposed symmetry-improved 2PI formalism, we address the problem of the Goldstone-boson IR divergences of the SM effective potential in the gaugeless limit of the theory. In the same limit, we evaluate the IR-safe symmetry-improved 2PI effective potential, after taking into account quantum loops of chiral fermions, as well as the renormalization of spurious custodially breaking effects triggered by fermionic Yukawa interactions. Finally, we compare our results with those obtained with other methods presented in the literature.

  3. Zeeman effect in CaF(2Pi(3/2)).

    PubMed

    Krems, R V; Egorov, D; Helton, J S; Maussang, K; Nguyen, S V; Doyle, J M

    2004-12-15

    The Zeeman effect in the excited A 2Pi(3/2) state of CaF is measured and analyzed over a wide range of magnetic fields. It is found that the splitting of the Zeeman levels is largely determined by the coupling between different rotational states and there are no low-field seeking states in the J=3/2 manifold of Zeeman levels at high magnetic fields. A model of the Zeeman spectrum based on the ligand-field theory of CaF is shown to be accurate in the interval of magnetic fields 0-5 Tesla. This demonstrates that the magnetic moment of the CaF(A 2Pi(3/2)) molecule is effectively determined by the spin angular momentum of a single electron and the orbital motion of the valence electron around the Ca2+ core. An analysis of the Zeeman spectrum as a function of the molecular rotational constant indicates that 2Pi(3/2) molecules should have significant rotational constants (at least as large as twice the rotational constant of CaF) to be amenable to magnetic trapping in high fields.

  4. Two-particle irreducible effective actions versus resummation: Analytic properties and self-consistency

    NASA Astrophysics Data System (ADS)

    Brown, Michael; Whittingham, Ian

    2015-11-01

    Approximations based on two-particle irreducible (2PI) effective actions (also known as Φ-derivable, Cornwall-Jackiw-Tomboulis or Luttinger-Ward functionals depending on context) have been widely used in condensed matter and non-equilibrium quantum/statistical field theory because this formalism gives a robust, self-consistent, non-perturbative and systematically improvable approach which avoids problems with secular time evolution. The strengths of 2PI approximations are often described in terms of a selective resummation of Feynman diagrams to infinite order. However, the Feynman diagram series is asymptotic and summation is at best a dangerous procedure. Here we show that, at least in the context of a toy model where exact results are available, the true strength of 2PI approximations derives from their self-consistency rather than any resummation. This self-consistency allows truncated 2PI approximations to capture the branch points of physical amplitudes where adjustments of coupling constants can trigger an instability of the vacuum. This, in effect, turns Dyson's argument for the failure of perturbation theory on its head. As a result we find that 2PI approximations perform better than Padé approximation and are competitive with Borel-Padé resummation. Finally, we introduce a hybrid 2PI-Padé method.

  5. Constraining the effective action by a method of external sources

    NASA Astrophysics Data System (ADS)

    Garbrecht, Björn; Millington, Peter

    2016-05-01

    We propose a novel method of evaluating the effective action, wherein the physical one- and two-point functions are obtained in the limit of non-vanishing external sources. We illustrate the self-consistency of this method by recovering the usual 2PI effective action due to Cornwall, Jackiw and Tomboulis, differing only by the fact that the saddle-point evaluation of the path integral is performed along the extremal quantum, rather than classical, path. As such, this approach is of particular relevance to situations where the dominant quantum and classical paths are non-perturbatively far away from one-another. A pertinent example is the decay of false vacua in radiatively-generated potentials, as may occur for the electroweak vacuum of the Standard Model. In addition, we describe how the external sources may instead be chosen so as to yield the two-particle-point-irreducible (2PPI) effective action of Coppens and Verschelde. Finally, in the spirit of the symmetry-improved effective action of Pilaftsis and Teresi, we give an example of how the external sources can be used to preserve global symmetries in truncations of the 2PI effective action. Specifically, in the context of an O (2) model with spontaneous symmetry breaking, we show that this approach allows the Hartree-Fock approximation to be re-organized, such that the Goldstone boson remains massless algebraically in the symmetry-broken phase and we obtain the correct second-order thermal phase transition.

  6. Action languages: Dimensions, effects

    NASA Technical Reports Server (NTRS)

    Hayes, Daniel G.; Streeter, Gordon

    1989-01-01

    Dimensions of action languages are discussed for communication between humans and machines, and the message handling capabilities of object oriented programming systems are examined. Design of action languages is seen to be very contextual. Economical and effective design will depend on features of situations, the tasks intended to be accomplished, and the nature of the devices themselves. Current object oriented systems turn out to have fairly simple and straightforward message handling facilities, which in themselves do little to buffer action or even in some cases to handle competing messages. Even so, it is possible to program a certain amount of discretion about how they react to messages. Such thoughtfulness and perhaps relative autonomy of program modules seems prerequisite to future systems to handle complex interactions in changing situations.

  7. Two-particle irreducible effective action approach to nonlinear current-conserving approximations in driven systems.

    PubMed

    Peralta-Ramos, J; Calzetta, E

    2009-05-27

    Using closed-time-path two-particle irreducible coarse-grained effective action (CTP 2PI CGEA) techniques, we study the response of an open interacting electronic system to time-dependent external electromagnetic fields. We show that the CTP 2PI CGEA is invariant under a simultaneous gauge transformation of the external field and the full Schwinger-Keldysh propagator, and that this property holds even when the loop expansion of the CTP 2PI CGEA is truncated at arbitrary order. The effective action approach provides a systematic way of calculating the propagator and response functions of the system, via the Schwinger-Dyson equation and the Bethe-Salpeter equations, respectively. We show that, due to the invariance of the CTP 2PI CGEA under external gauge transformations, the response functions calculated from it satisfy the Ward-Takahashi hierarchy, thus warranting the conservation of the electronic current beyond the expectation value level. We also clarify the connection between nonlinear response theory and the WT hierarchy, and discuss an example of an ad hoc approximation that violates it. These findings may be useful in the study of current fluctuations in correlated electronic pumping devices.

  8. Hydroxyl X2Pi pure rotational transitions

    NASA Technical Reports Server (NTRS)

    Goorvitch, D.; Goldman, A.; Dothe, Hoang; Tipping, R. H.; Chackerian, C., Jr.

    1992-01-01

    We present a list of frequencies, term values, Einstein A values, and assignments for the pure rotational transitions of the X2Pi state of the OH molecule. This list includes transitions from 3 to 2015/cm for Delta-v = 0, v-double-prime = 0-4, and J-double-prime = 0.5-49.5. The A values were computed using recent advances in calculating wave functions for a coupled system and an experimentally derived electric dipole moment function (Nelson et al., 1990) which exhibits curvature.

  9. New effective interaction for 0({Dirac_h}/2{pi}){omega} shell-model calculations in the sd-pf valence space

    SciTech Connect

    Nowacki, F.; Poves, A.

    2009-01-15

    The neutron-rich isotopes with Z{<=}20, in particular those with neutron numbers around N=28, have been the focus of a lot experimental and theoretical scrutiny during the past few years. Shell-model calculations using the effective interaction SDPF-NR were able to predict or to explain most of the properties featured by these nuclei. Prominent among them is the disappearance of the N=28 shell closure for Z{<=}16. We have incorporated into SDPF-NR some modifications, either on purely theoretical grounds or guided by new experimental information. The proposed interaction SDPF-U offers enhanced reliability with respect to the earlier version.

  10. Schwinger multichannel study of the 2Pi(g) shape resonance in N2

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Gibson, Thomas L.; Lima, Marco A. P.; Mckoy, Vincent

    1987-01-01

    The results of a study on electron-target correlations in the 2Pi(g) shape resonance of elastic e-N2 scattering, using the Schwinger multichannel formulation, are reported. The effects of basis set, orbital representation, and closed-channel-configurations are delineated. The different roles of radial and angular correlations are compared.

  11. Effective action in spherical domains

    NASA Astrophysics Data System (ADS)

    Dowker, J. S.

    1994-05-01

    The effective action on an orbifolded sphere is computed for minimally coupled scalar fields. The results are presented in terms of derivatives of Barnes ζ-functions and it is shown how these may be evaluated. Numerical values are shown. An analytical, heat-kernel derivation of the Cesàro-Fedorov formula for the number of symmetry planes of a regular solid is also presented.

  12. Learning from their own actions: the unique effect of producing actions on infants' action understanding.

    PubMed

    Gerson, Sarah A; Woodward, Amanda L

    2014-01-01

    Prior research suggests that infants' action production affects their action understanding, but little is known about the aspects of motor experience that render these effects. In Study 1, the relative contributions of self-produced (n = 30) and observational (n = 30) action experience on 3-month-old infants' action understanding was assessed using a visual habituation paradigm. In Study 2, generalization of training to a new context was examined (n = 30). Results revealed a unique effect of active over observational experience. Furthermore, findings suggest that benefits of trained actions do not generalize broadly, at least following brief training.

  13. High resolution absorption cross sections for the A2Pi-X2Pi system of ClO

    NASA Technical Reports Server (NTRS)

    Wine, P. H.; Ravishankara, A. R.; Philen, D. L.; Davis, D. D.; Watson, R. T.

    1977-01-01

    High-resolution ultraviolet absorption cross-sections for the ClO molecule are obtained, with the aim of facilitating studies of ozone depletion resulting from the injection of chlorofluorocarbons into the atmosphere. The spectroscopic analysis, which involves a frequency-doubled tunable dye laser with a bandwidth of 0.015 A, is described. Studies of the rotational lines of the ClO A 2Pi 3/2-X2Pi 3/2 9-10 band were conducted. Peak cross-sections for the P and R lines of the 9-0 band are found to be 10.0, 9.6, 8.6, 10.6, 10.3, and 9.2 times ten to the negative seventeenth power cm squared, with estimated accuracy of plus or minus 25%. Problems in distinguishing between Cl-35 and Cl-37 absorption are also considered.

  14. The GROOP Effect: Groups Mimic Group Actions

    ERIC Educational Resources Information Center

    Tsai, Jessica Chia-Chin; Sebanz, Natalie; Knoblich, Gunther

    2011-01-01

    Research on perception-action links has focused on an interpersonal level, demonstrating effects of observing individual actions on performance. The present study investigated perception-action matching at an inter-group level. Pairs of participants responded to hand movements that were performed by two individuals who used one hand each or they…

  15. Understanding Action beyond Imitation: Reversed Compatibility Effects of Action Observation in Imitation and Joint Action

    ERIC Educational Resources Information Center

    van Schie, Hein T.; van Waterschoot, Boris M.; Bekkering, Harold

    2008-01-01

    A robust finding in imitation literature is that people perform their actions more readily if they are congruent with the behavior of another person. These action congruency effects are typically explained by the idea that the observation of someone else acting automatically activates our motor system in a directly matching way. In the present…

  16. Action orientation overcomes the ego depletion effect.

    PubMed

    Dang, Junhua; Xiao, Shanshan; Shi, Yucai; Mao, Lihua

    2015-04-01

    It has been consistently demonstrated that initial exertion of self-control had negative influence on people's performance on subsequent self-control tasks. This phenomenon is referred to as the ego depletion effect. Based on action control theory, the current research investigated whether the ego depletion effect could be moderated by individuals' action versus state orientation. Our results showed that only state-oriented individuals exhibited ego depletion. For individuals with action orientation, however, their performance was not influenced by initial exertion of self-control. The beneficial effect of action orientation against ego depletion in our experiment results from its facilitation for adapting to the depleting task.

  17. Conformal symmetry of brane world effective actions

    SciTech Connect

    McFadden, Paul L.; Turok, Neil

    2005-01-15

    A simple derivation of the low-energy effective action for brane worlds is given, highlighting the role of conformal invariance. We show how to improve the effective action for a positive- and negative-tension brane pair using the AdS/CFT correspondence.

  18. Optimal targeting of HER2-PI3K signaling in breast cancer: mechanistic insights and clinical implications.

    PubMed

    Rexer, Brent N; Arteaga, Carlos L

    2013-07-01

    The combination of a PI3K inhibitor with trastuzumab has been shown to be effective at overcoming trastuzumab resistance in models of HER2(+) breast cancer by inhibiting HER2-PI3K-FOXO-survivin signaling. In this review the potential clinical implications of these findings are discussed.

  19. Wilsonian effective action of superstring theory

    NASA Astrophysics Data System (ADS)

    Sen, Ashoke

    2017-01-01

    By integrating out the heavy fields in type II or heterotic string field theory one can construct the effective action for the light fields. This effective theory inherits all the algebraic structures of the parent theory and the effective action automatically satisfies the Batalin-Vilkovisky quantum master equation. This theory is manifestly ultraviolet finite, has only light fields as its explicit degrees of freedom, and the Feynman diagrams of this theory reproduce the exact scattering amplitudes of light states in string theory to any arbitrary order in perturbation theory. Furthermore in this theory the degrees of freedom of light fields above certain energy scale are also implicitly integrated out. This energy scale is determined by a particular parameter labelling a family of equivalent actions, and can be made arbitrarily low, leading to the interpretation of the effective action as the Wilsonian effective action.

  20. Improved line parameters for the Chi 2Pi-Chi 2Pi (1-0) bands of (35)ClO and (37)ClO

    NASA Technical Reports Server (NTRS)

    Goldman, Aaron; Gillis, James R.; Rinsland, Curtis P.; Burkholder, James B.

    1994-01-01

    Improved line parameters at 296 K for the Chi 2Pi-Chi 2Pi (1-0) bands of (35)ClO and (37)ClO have been calculated with J up to 43.5. The integrated intensity for the 2048 lines in the main and satellite bands has been normalized to 9.68-sq cm/atm at 296K.

  1. Action-based effects on music perception.

    PubMed

    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.

  2. Action-based effects on music perception

    PubMed Central

    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

  3. Action-effect bindings and ideomotor learning in intention- and stimulus-based actions.

    PubMed

    Herwig, Arvid; Waszak, Florian

    2012-01-01

    According to ideomotor theory, action-effect associations are crucial for voluntary action control. Recently, a number of studies started to investigate the conditions that mediate the acquisition and application of action-effect associations by comparing actions carried out in response to exogenous stimuli (stimulus-based) with actions selected endogenously (intention-based). There is evidence that the acquisition and/or application of action-effect associations is boosted when acting in an intention-based action mode. For instance, bidirectional action-effect associations were diagnosed in a forced choice test phase if participants previously experienced action-effect couplings in an intention-based but not in a stimulus-based action mode. The present study aims at investigating effects of the action mode on action-effect associations in more detail. In a series of experiments, we compared the strength and durability of short-term action-effect associations (binding) immediately following intention- as well as stimulus-based actions. Moreover, long-term action-effect associations (learning) were assessed in a subsequent test phase. Our results show short-term action-effect associations of equal strength and durability for both action modes. However, replicating previous results, long-term associations were observed only following intention-based actions. These findings indicate that the effect of the action mode on long-term associations cannot merely be a result of accumulated short-term action-effect bindings. Instead, only those episodic bindings are selectively perpetuated and retrieved that integrate action-relevant aspects of the processing event, i.e., in case of intention-based actions, the link between action and ensuing effect.

  4. Action-effect coupling in pianists.

    PubMed

    Drost, Ulrich C; Rieger, Martina; Brass, Marcel; Gunter, Thomas C; Prinz, Wolfgang

    2005-03-01

    Recent theories have stressed the role of effect anticipation in action control. Such a mechanism requires the prior acquisition of integrated action-effect associations. The strength of such associations should directly depend on the amount of learning, and therefore be most pronounced in motor experts. Using an interference paradigm, we investigated whether evidence of such representations can be demonstrated in expert pianists. Participants were required to play chords on a keyboard in response to imperative visual stimuli. Concurrently, task-irrelevant auditory stimuli ("potential" action effects) were presented that were congruent or incongruent with the chords to be played. In Experiment 1 we found evidence that expert pianists, compared with non-musicians, have acquired such action-effects representations. Response times were slower when the auditory stimulus was incongruent with the required response. In order to ascertain the locus of interference, we varied imperative stimuli and responses in Experiments 2 and 3. The results indicate that, for the most part, interference occurs on the response level rather than on an abstract level. However, the perception of action effects also evokes processing of abstract features, like the concept of major-minor mode.

  5. Effective actions for bosonic topological defects

    NASA Technical Reports Server (NTRS)

    Gregory, Ruth

    1990-01-01

    A gauge field theory is considered which admits p-dimensional topological defects, expanding the equations of motion in powers of the defect thickness. In this way an effective action and effective equation of motion is derived for the defect in terms of the coordinates of the p-dimensional worldsurface defined by the history of the core of the defect.

  6. Parity propensities in rotational energy transfer of OH X 2Pi(i) with helium

    NASA Technical Reports Server (NTRS)

    Wysong, Ingrid J.; Jeffries, Jay B.; Crosley, David R.

    1991-01-01

    Preliminary results of rotational energy transfer in ground state OH in collisions in He are reported. A surprising propensity is found: conservation of total parity is favored in collisions which change in spin-orbit component, the reversible reaction 2Pi3/2 yields 2Pi1/2. This has implications concerning the OH-He potential surface.

  7. From Outcome Prediction to Action Selection: Developmental Change in the Role of Action-Effect Bindings

    ERIC Educational Resources Information Center

    Verschoor, Stephan A.; Spapé, Michiel; Biro, Szilvia; Hommel, Bernhard

    2013-01-01

    Ideomotor theory considers bidirectional action-effect associations to be the fundamental building blocks for intentional action. The present study employed a novel pupillometric and oculomotor paradigm to study developmental changes in the role of action-effects in the acquisition of voluntary action. Our findings suggest that both 7- and…

  8. (-)-Carvone: antispasmodic effect and mode of action.

    PubMed

    Souza, Fábia Valéria M; da Rocha, Marcelly Barbosa; de Souza, Damião P; Marçal, Rosilene Moretti

    2013-03-01

    (-)-Carvone is a monoterpene ketone found in spearmint (Mentha spicata var. crispa) essential oil that is widely used as an odor and flavor additive. An intestinal antispasmodic effect was recently reported for (-)-carvone, and it has been shown to be more potent than its (+)-antipode. The mechanism of (-)-carvone action in the intestines has not been investigated. To gain a better understanding of the (-)-carvone antispasmodic effect, we investigated its pharmacological effects in the guinea pig ileum. Terminal portions of the ileum were mounted for isotonic contraction recordings. The effect of (-)-carvone was compared with that of the classical calcium channel blocker (CCB) verapamil. In isolated ileal smooth muscle, (-)-carvone did not produce direct contractile or relaxation responses and did not modify electrically elicited contractions or low K(+)-evoked contractions. The submaximal contractions induced by histamine (p<0.001), BaCl2 (p<0.05), and carbachol (p<0.01) were significantly reduced by (-)-carvone. The contractile response elicited by high concentrations of carbachol was reduced but not abolished by (-)-carvone. No additive action was detected with co-incubation of (-)-carvone and verapamil on carbachol-induced contraction. (-)-Carvone reduced the contraction induced by high K(+) and was almost 100 times more potent than verapamil. Thus, (-)-carvone showed a typical and potent CCB-like action. Many effects described for both (-)-carvone and spearmint oil can be explained as a CCB-like mode of action.

  9. ERP correlates of action effect prediction and visual sensory attenuation in voluntary action.

    PubMed

    Hughes, Gethin; Waszak, Florian

    2011-06-01

    Sensory attenuation of voluntary action effects has been widely reported in both somatosensory and auditory domains. However, relatively little research has focused on physiological measures of sensory attenuation of visual action effects. One previous study found, perhaps surprisingly, that both auditory and visual sensory attenuation were manifested as decreased ERP amplitude over the vertex. The present study aimed to extend these findings using a novel paradigm in which voluntary actions were either associated with a visual action effect or to no effect. Crucially, this allowed us to explore both sensory attenuation (by comparing ERPs to action-triggered versus externally triggered stimuli) and action effect prediction (by comparing actions that triggered a stimulus with actions that did not). With regard to sensory attenuation, we found that attenuation of cortical responses to visual action effects was manifested in a reduced activation of a frontoparietal network, from 150 ms after stimulus. Differences between actions that produced an effect and those that did not were observed in lateralized motor potentials and may reflect the cortical correlates of the action effect prediction. We also observed a re-activation of lateralized motor activity following onset of the action effect, suggesting a common representation of action effects in visual and motor cortices. Taken together, these findings help to elucidate the cortical mechanisms of voluntary action as well as their sensory consequences and inform how our interaction with the external world is processed and controlled.

  10. Sensory Attenuation for Jointly Produced Action Effects

    PubMed Central

    Loehr, Janeen D.

    2012-01-01

    Successful joint action often requires people to distinguish between their own and others’ contributions to a shared goal. One mechanism that is thought to underlie a self-other distinction is sensory attenuation, whereby the sensory consequences of one’s own actions are reduced compared to other sensory events. Previous research has shown that the auditory N1 event-related potential (ERP) response is reduced for self-generated compared to externally generated tones. The current study examined whether attenuation also occurs for jointly generated tones, which require two people to coordinate their actions to produce a single tone. ERP responses were measured when participants generated tones alone (tone onset immediately followed the participant’s button press) or with a partner (tone onset immediately followed the participant’s or the partner’s button press, whichever occurred second). N1 attenuation was smaller for jointly generated tones compared to self-generated tones. For jointly generated tones, greater delays between the participant’s and the partner’s button presses were associated with reduced attenuation; moreover, only trials in which there was no delay between the participant’s press and tone onset showed attenuation, whereas trials in which there were delays did not show attenuation. These findings indicate that people differentiate between their own and another person’s contributions to a joint action at the sensorimotor level, even when they must act together to produce a single, shared effect. PMID:23596429

  11. Rotationally inelastic scattering of OH (2Pi 3/2, v=0, J=3/2, f) by HBr (1Sigma, v=0, J<4).

    PubMed

    Moise, A; Cireasa, R; Parker, D H; ter Meulen, J J

    2006-11-28

    Relative state-to-state cross sections of OH molecules in the (2)Pi(32), v=0, J=32, M(J)=32, f state have been determined for transitions up to (2)Pi(32), v=0, J=112, f and (2)Pi(12), v=0, J=72, e states by collisions with HBr molecules ((1)Sigma, v=0, J<4) at 750 cm(-1) collision energy. In order to investigate features of the anisotropy of the OH-HBr potential energy surface, the steric asymmetries, which account for the effect of the OH orientation with respect to the collision partner, have been measured. A comparison with other systems previously studied shows strong similarities with the OH-HCl system.

  12. Winning and Losing: Effects on Impulsive Action

    PubMed Central

    2016-01-01

    In the present study, we examined the effect of wins and losses on impulsive action in gambling (Experiments 1–3) and nongambling tasks (Experiments 4–5). In each experiment, subjects performed a simple task in which they had to win points. On each trial, they had to choose between a gamble and a nongamble. The gamble was always associated with a higher amount but a lower probability of winning than the nongamble. After subjects indicated their choice (i.e., gamble or not), feedback was presented. They had to press a key to start the next trial. Experiments 1–3 showed that, compared to the nongambling baseline, subjects were faster to initiate the next trial after a gambled loss, indicating that losses can induce impulsive actions. In Experiments 4 and 5, subjects alternated between the gambling task and a neutral decision-making task in which they could not win or lose points. Subjects were faster in the neutral decision-making task if they had just lost in the gambling task, suggesting that losses have a general effect on action. Our results challenge the dominant idea that humans become more cautious after suboptimal outcomes. Instead, they indicate that losses in the context of potential rewards are emotional events that increase impulsivity. PMID:27808548

  13. Effectiveness of a solar action campaign

    SciTech Connect

    Tucker, M.

    1981-01-01

    This paper discusses the effectiveness of a Solar Action Campaign implemented to facilitate the commercialization of Solar Energy in a large metropolitan area. The campaign was developed by the staff of the Crosby Gardens Environmental Library. Crosby Gardens is an urban environmental and cultural park. The Solar Action Campaign in Toledo, Ohio, included the coordination of a variety of activities and events designed to stimulate consumer awareness of the Solar Energy applications in the area. Activities included coordinating two workshops, production of media tools, a sunshine awards banquet, and an intensive media campaign. The Solar Week in Toledo provided the stimulus for coalitions to be built, intensive information exchange, and most importantly - media coverage.

  14. Effective Action for Bose-Einstein Condensates

    NASA Astrophysics Data System (ADS)

    Kita, Takafumi

    2014-06-01

    We clarify basic properties of an effective action (i.e., self-consistent perturbation expansion) for interacting Bose-Einstein condensates, where field ψ itself acquires a finite thermodynamic average < ψ > besides two-point Green's function hat{G} to form an off-diagonal long-range order. It is shown that the action can be expressed concisely order by order in terms of the interaction vertex and a special combination of < ψ > and hat{G} so as to satisfy both Noether's theorem and Goldstone's theorem (I) corresponding to the first proof. The self-energy is predicted to have a one-particle-reducible structure due to < ψ > ≠ 0 to transform the Bogoliubov mode into a bubbling mode with a substantial decay rate.

  15. Subliminal priming of actions influences sense of control over effects of action.

    PubMed

    Wenke, Dorit; Fleming, Stephen M; Haggard, Patrick

    2010-04-01

    The experience of controlling one's own actions, and through them events in the outside world, is a pervasive feature of human mental life. Two experiments investigated the relation between this sense of control and the internal processes involved in action selection and cognitive control. Action selection was manipulated by subliminally priming left or right keypress actions in response to a supraliminal visual target. The action caused the display of one of several colours as an action effect. The specific colour shown depended on whether the participant's action was compatible or incompatible with the preceding subliminal prime, and not on the prime identity alone. Unlike previous studies, therefore, the primes did not predict the to-be-expected action effects. Participants rated how much control they experienced over the different colours. Replicating previous results, compatible primes facilitated responding, whereas incompatible primes interfered with response selection. Crucially, priming also modulated the sense of control over action effects: participants experienced more control over colours produced by actions that were compatible with the preceding prime than over colours associated with prime-incompatible actions. Experiment 2 showed that this effect was not solely due to priming modulating action-effect contingencies. These results suggest that sense of control is linked to processes of selection between alternative actions, being strongest when selection is smooth and uncontested.

  16. Representing the Hyphen in Action-Effect Associations: Automatic Acquisition and Bidirectional Retrieval of Action-Effect Intervals

    ERIC Educational Resources Information Center

    Dignath, David; Pfister, Roland; Eder, Andreas B.; Kiesel, Andrea; Kunde, Wilfried

    2014-01-01

    We examined whether a temporal interval between an action and its sensory effect is integrated in the cognitive action structure in a bidirectional fashion. In 3 experiments, participants first experienced that actions produced specific acoustic effects (high and low tones) that occurred temporally delayed after their actions. In a following test…

  17. Effective action theory of Andreev level spectroscopy

    NASA Astrophysics Data System (ADS)

    Galaktionov, Artem V.; Zaikin, Andrei D.

    2015-12-01

    With the aid of the Keldysh effective action technique we develop a microscopic theory describing Andreev level spectroscopy experiments in nontunnel superconducting contacts. We derive an effective impedance of such contacts which accounts for the presence of Andreev levels in the system. At subgap bias voltages and low temperatures, inelastic Cooper pair tunneling is accompanied by transitions between these levels resulting in a set of sharp current peaks. We evaluate the intensities of such peaks, establish their dependence on the external magnetic flux piercing the structure and estimate the thermal broadening of these peaks. We also specifically address the effect of capacitance renormalization in a nontunnel superconducting contact and its impact on both the positions and heights of the current peaks. At overgap bias voltages, the I -V curve is determined by quasiparticle tunneling and contains current steps related to the presence of discrete Andreev states in our system.

  18. Theoretical study of the dipole moment function of OH(X2Pi)

    NASA Technical Reports Server (NTRS)

    Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Taylor, Peter R.

    1989-01-01

    A theoretical study of the sensitivity of the dipole moment function (DMF) of the X2Pi ground state of OH to basis-set saturation and to refinements in the correlation treatment is presented. Emphasis is placed on determining the slope of the DMF at r(e) and the r value at which the maximum occurs. Consideration is given to the effect of oxygen polarization functions up through h type, expansion of the active orbital space to include the O 3d-delta orbital, the effect of higher excitations using the averaged coupled-pair functional method, and the effect of evaluating the dipole moment as an energy derivative rather than as an expectation value. The theoretical DMFs obtained here, which should be the most accurate to date, differ markedly from an empirical DMF of Turnbull and Lowe that is based on experimentally derived intensity ratios. The theoretical DMFs agree better with a recently published DMF of Nelson et al., but suggest that this empirical DMF is also inaccurate for r greater than 2.3 a0.

  19. Embracing causality in specifying the indeterminate effects of actions

    SciTech Connect

    Lin, F.

    1996-12-31

    This paper makes the following two contributions to formal theories of actions: Showing that a causal minimization framework can be used effectively to specify the effects of indeterminate actions; and showing that for certain classes of such actions, regression, an effective computational mechanism, can be used to reason about them.

  20. Effective actions for relativistic fluids from holography

    NASA Astrophysics Data System (ADS)

    de Boer, Jan; Heller, Michal P.; Pinzani-Fokeeva, Natalia

    2015-08-01

    Motivated by recent progress in developing action formulations of relativistic hydrodynamics, we use holography to derive the low energy dissipationless effective action for strongly coupled conformal fluids. Our analysis is based on the study of novel double Dirichlet problems for the gravitational field, in which the boundary conditions are set on two codimension one timelike hypersurfaces (branes). We provide a geometric interpretation of the Goldstone bosons appearing in such constructions in terms of a family of spatial geodesics extending between the ultraviolet and the infrared brane. Furthermore, we discuss supplementing double Dirichlet problems with information about the near-horizon geometry. We show that upon coupling to a membrane paradigm boundary condition, our approach reproduces correctly the complex dispersion relation for both sound and shear waves. We also demonstrate that upon a Wick rotation, our formulation reproduces the equilibrium partition function formalism, provided the near- horizon geometry is properly accounted for. Finally, we define the conserved hydrodynamic entropy current as the Noether current associated with a particular transformation of the Goldstone bosons.

  1. From action intentions to action effects: how does the sense of agency come about?

    PubMed Central

    Chambon, Valérian; Sidarus, Nura; Haggard, Patrick

    2014-01-01

    Sense of agency refers to the feeling of controlling an external event through one’s own action. On one influential view, agency depends on how predictable the consequences of one’s action are, getting stronger as the match between predicted and actual effect of an action gets closer. Thus, sense of agency arises when external events that follow our action are consistent with predictions of action effects made by the motor system while we perform or simply intend to perform an action. According to this view, agency is inferred retrospectively, after an action has been performed and its consequences are known. In contrast, little is known about whether and how internal processes involved in the selection of actions may influence subjective sense of control, in advance of the action itself, and irrespective of effect predictability. In this article, we review several classes of behavioral and neuroimaging data suggesting that earlier processes, linked to fluency of action selection, prospectively contribute to sense of agency. These findings have important implications for better understanding human volition and abnormalities of action experience. PMID:24860486

  2. Causal binding of actions to their effects.

    PubMed

    Buehner, Marc J; Humphreys, Gruffydd R

    2009-10-01

    According to widely held views in cognitive science harking back to David Hume, causality cannot be perceived directly, but instead is inferred from patterns of sensory experience, and the quality of these inferences is determined by perceivable quantities such as contingency and contiguity. We report results that suggest a reversal of Hume's conjecture: People's sense of time is warped by the experience of causality. In a stimulus-anticipation task, participants' response behavior reflected a shortened experience of time in the case of target stimuli participants themselves had generated, relative to equidistant, equally predictable stimuli they had not caused. These findings suggest that causality in the mind leads to temporal binding of cause and effect, and extend and generalize beyond earlier claims of intentional binding between action and outcome.

  3. The e^+e^- -> 3(\\pi^+\\pi^-), 2(\\pi^+\\pi^-\\pi^0) and K^+K^-2(\\pi^+\\pi^-) Cross Sections at Center-of-Mass Energies 0.5--4.5 GeV Measured with Initial-State Radiation

    SciTech Connect

    Aubert, B.

    2006-02-08

    We study the processes e{sup +}e{sup -} {yields} 3({pi}{sup +}{pi}{sup -}){gamma}, 2({pi}{sup +}{pi}{sup -}{pi}{sup 0}){gamma} and K{sup +}K{sup -} 2({pi}{sup +} {sup -}){gamma}, with the photon radiated from the initial state. About 20,000, 33,000 and 4,000 fully reconstructed events, respectively, have been selected from 232 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} center-of-mass energy, so that these data can be compared with the corresponding direct e{sup +}e{sup -} measurements. From the 3({pi}{sup +}{pi}{sup -}), 2({pi}{sup +}{pi}{sup -}{pi}{sup 0}) and K{sup +}K{sup -} 2({pi}{sup +}{pi}{sup -}) mass spectra, the cross sections for the processes e{sup +}e{sup -} {yields} 3({pi}{sup +}{sup -}), e{sup +}e{sup -} {yields} 2({pi}{sup +}{pi}{sup -}{pi}{sup 0}) and e{sup +}e{sup -} {yields} K{sup +}K{sup -} 2({pi}{sup +}{pi}{sup -}) are measured for center-of-mass energies from production threshold to 4.5 GeV. The uncertainty in the cross section measurement is typically 6-15%. We observe the J/{psi} in all these final states and measure the corresponding branching fractions.

  4. Two-Loop Effective Action for Theories with Fermions

    NASA Astrophysics Data System (ADS)

    Faizullaev, B. A.; Musakhanov, M. M.

    1995-08-01

    On the basis of a new approach for the calculation of the effective action developed in our previous works we calculate the effective action (up to two-loop level) for some models containing fermion fields. This method allows us to calculate the fermionic part of the effective action properly. The two-loop contribution to the effective potential for the Nambu-Jona-Lasinio model is calculated and is shown to vanish.

  5. Effects of social intention on movement kinematics in cooperative actions.

    PubMed

    Quesque, François; Lewkowicz, Daniel; Delevoye-Turrell, Yvonne N; Coello, Yann

    2013-01-01

    Optimal control models of biological movements are used to account for those internal variables that constrain voluntary goal-directed actions. They, however, do not take into account external environmental constraints as those associated to social intention. We investigated here the effects of the social context on kinematic characteristics of sequential actions consisting in placing an object on an initial pad (preparatory action) before reaching and grasping as fast as possible the object to move it to another location (main action). Reach-to-grasp actions were performed either in an isolated condition or in the presence of a partner (audience effect), located in the near or far space (effect of shared reachable space), and who could intervene on the object in a systematic fashion (effect of social intention effect) or not (effect of social uncertainty). Results showed an absence of audience effect but nevertheless an influence of the social context both on the main and the preparatory actions. In particular, a "localized" effect of shared reachable space was observed on the main action, which was smoother when performed within the reachable space of the partner. Furthermore, a "global" effect of social uncertainty was observed on both actions with faster and jerkier movements. Finally, social intention affected the preparatory action with higher wrist displacements and slower movements when the object was placed for the partner rather than placed for self-use. Overall, these results demonstrate specific effects of action space, social uncertainty and social intention on the planning of reach-to-grasp actions, in particular on the preparatory action, which was performed with no specific execution constraint. These findings underline the importance of considering the social context in optimal models of action control for human-robot interactions, in particular when focusing on the implementation of motor parameters required to afford intuitive interactions.

  6. Movements or targets: what makes an action in action-effect learning?

    PubMed

    Hoffmann, Joachim; Lenhard, Alexandra; Sebald, Albrecht; Pfister, Roland

    2009-12-01

    According to ideomotor theory, actions become linked to the sensory feedback they contingently produce, so that anticipating the feedback automatically evokes the action it typically results from. Numerous recent studies have provided evidence in favour of such action-effect learning but left an important issue unresolved. It remains unspecified to what extent action-effect learning is based on associating effect-representations to representations of the performed movements or to representations of the targets at which the behaviour aimed at. Two experiments were designed to clarify this issue. In an acquisition phase, participants learned the contingency between key presses and effect tones. In a following test phase, key-effect and movement-effect relations were orthogonally assessed by changing the hand-key mapping for one half of the participants. Experiment 1 showed precedence for target-effect over movement-effect learning in a forced-choice RT task. In Experiment 2, target-effect learning was also shown to influence the outcome of response selection in a free-choice task. Altogether, the data indicate that both movement-effect and target-effect associations contribute to the formation of action-effect linkages-provided that movements and targets are likewise contingently related to the effects.

  7. Iron corrolates: unambiguous chloroiron(III) (corrolate)(2-.) pi-cation radicals.

    PubMed

    Walker, F Ann; Licoccia, Silvia; Paolesse, Roberto

    2006-04-01

    The structures, electron configurations, magnetic susceptibilities, spectroscopic properties, molecular orbital energies and spin density distributions, redox properties and reactivities of iron corrolates having chloride, phenyl, pyridine, NO and other ligands are reviewed. It is shown that with one very strong donor ligand such as phenyl anion the electron configuration of the metal is d(4)S=1 Fe(IV) coordinated to a (corrolate)(3-) anion, while with one weaker donor ligand such as chloride or other halide, the electron configuration is d(5)S=3/2 Fe(III) coordinated to a (corrolate)(2-.) pi-cation radical, with antiferromagnetic coupling between the metal and corrolate radical electron. Many of these complexes have been studied by electrochemical techniques and have rich redox reactivity, in most cases involving two 1-electron oxidations and two 1-electron reductions, and it is not possible to tell, from the shapes of cyclic voltammetric waves, whether the electron is added or removed from the metal or the macrocycle; often infrared, UV-Vis, or EPR spectroscopy can provide this information. (1)H and (13)C NMR spectroscopic methods are most useful in delineating the spin state and pattern of spin density distribution of the complexes listed above, as would also be expected to be the case for the recently-reported formal Fe(V)O corrolate, if this complex were stable enough for characterization by NMR spectroscopy. Iron, manganese and chromium corrolates can be oxidized by iodosylbenzene and other common oxidants used previously with metalloporphyrinates to effect efficient oxidation of substrates. Whether the "resting state" form of these complexes, most generally in the case of iron [FeCl(Corr)], actually has the electron configuration Fe(IV)(Corr)(3-) or Fe(III)(Corr)(2-.) is not relevant to the high-valent reactivity of the complex.

  8. The Role of Attention in a Joint-Action Effect

    PubMed Central

    Doneva, Silviya P.; Cole, Geoff G.

    2014-01-01

    The most common explanation for joint-action effects has been the action co-representation account in which observation of another's action is represented within one's own action system. However, recent evidence has shown that the most prominent of these joint-action effects (i.e., the Social Simon effect), can occur when no co-actor is present. In the current work we examined whether another joint-action phenomenon (a movement congruency effect) can be induced when a participant performs their part of the task with a different effector to that of their co-actor and when a co-actor's action is replaced by an attention-capturing luminance signal. Contrary to what is predicted by the action co-representation account, results show that the basic movement congruency effect occurred in both situations. These findings challenge the action co-representation account of this particular effect and suggest instead that it is driven by bottom-up mechanisms. PMID:24642806

  9. The role of attention in a joint-action effect.

    PubMed

    Doneva, Silviya P; Cole, Geoff G

    2014-01-01

    The most common explanation for joint-action effects has been the action co-representation account in which observation of another's action is represented within one's own action system. However, recent evidence has shown that the most prominent of these joint-action effects (i.e., the Social Simon effect), can occur when no co-actor is present. In the current work we examined whether another joint-action phenomenon (a movement congruency effect) can be induced when a participant performs their part of the task with a different effector to that of their co-actor and when a co-actor's action is replaced by an attention-capturing luminance signal. Contrary to what is predicted by the action co-representation account, results show that the basic movement congruency effect occurred in both situations. These findings challenge the action co-representation account of this particular effect and suggest instead that it is driven by bottom-up mechanisms.

  10. Protein kinase A-mediated cell proliferation in brown preadipocytes is independent of Erk1/2, PI{sub 3}K and mTOR

    SciTech Connect

    Wang, Yanling; Sato, Masaaki; Guo, Yuan; Bengtsson, Tore; Nedergaard, Jan

    2014-10-15

    The physiological agonist norepinephrine promotes cell proliferation of brown preadipocytes during the process of tissue recruitment. In a primary culture system, cAMP mediates these adrenergic effects. In the present study, we demonstrated that, in contrast to other systems where the mitogenic effect of cAMP requires the synergistic action of (serum) growth factors, especially insulin/IGF, the cAMP effect in brown preadipocytes was independent of serum and insulin. Protein kinase A, rather than Epac, mediated the cAMP mitogenic effect. The Erk 1/2 family of MAPK, the PI{sub 3}K system and the mTOR complexes were all activated by cAMP, but these activations were not necessary for cAMP-induced cell proliferation; a protein kinase C isoform may be involved in mediating cAMP-activated cell proliferation. We conclude that the generally acknowledged cellular mediators for induction of cell proliferation are not involved in this process in the brown preadipocyte system; this conclusion may be of relevance both for examination of mechanisms for induction of brown adipose tissue recruitment but also for understanding the mechanism behind e.g. certain endocrine neoplasias. - Highlights: • cAMP can mimick norepinephrine-induced proliferation of brown preadipocytes. • The cAMP-induced proliferation can occur in the absence of serum, of any other growth factors, and of insulin. • Erk1/2, PI{sub 3}K and mTOR are cAMP activated but not involved in induction of proliferation. • A Protein Kinase C member may be in the signalling cascade. • This pathway analysis may also be of importance for certain endocrine hyper- and neoplasias.

  11. Steady-state 2. pi. pulses under conditions of passive locking of laser modes

    SciTech Connect

    Komarov, K.P.; Ugozhaev, V.D.

    1984-06-01

    A theoretical study is made of laser mode locking in the regime of self-induced transparency of a passive filter. It is shown that there is a solution in the form of ultrashort steady-state 2..pi.. pulses. The range of stability of this regime and its characteristics are determined. By way of example, estimates are obtained of parameters of a steady-state pulse emitted by an alexandrite laser with a potassium absorption cell.

  12. Chlorogenic Acid Prevents Osteoporosis by Shp2/PI3K/Akt Pathway in Ovariectomized Rats

    PubMed Central

    Zuo, Hui Ling; Yao, Fen Fen; Ruan, Hui Bing; Xu, Jin; Song, Wei; Zhou, Yi Cheng; Wen, Shi Yao; Dai, Jiang Hua; Zhu, Mei Lan; Luo, Jun

    2016-01-01

    differentiation by decreasing Shp2, p-Akt, and cyclin D1. This study found that CGA improved the BMD and trabecular micro-architecture for the OVX-induced osteoporosis. Therefore, CGA might be an effective alternative treatment for postmenopausal osteoporosis. CGA promoted proliferation of osteoblast precursors and osteoblastic differentiation of BMSCs via the Shp2/PI3K/Akt/cyclin D1 pathway. PMID:28033335

  13. Instanton Effective Action in Deformed Super Yang-Mills Theories

    SciTech Connect

    Nakajima, Hiroaki; Ito, Katsushi; Sasaki, Shin

    2008-11-23

    We study the ADHM construction of instantons in N = 2 supersymmetric Yang-Mills theory deformed in constant Ramond-Ramond (R-R) 3-form field strength background in type IIB superstrings. We compare the deformed instanton effective action with the effective action of fractional D3/D(-1) branes at the orbifold singularity of C{sup 2}/Z{sub 2} in the same R-R background. We find discrepancy between them at the second order in deformation parameters, which comes from the coupling of the translational zero modes of the D(-1)-branes to the R-R background. We improve the deformed action by adding a term with spacetime dependent gauge coupling such that the action reproduces the effective action of the fractional branes.

  14. The Evidence for the Effectiveness of Action Learning

    ERIC Educational Resources Information Center

    Leonard, H. Skipton; Marquardt, Michael J.

    2010-01-01

    For the past 50 years, organizations and individuals around the world have reported success in their use of action learning programs to solve problems, develop leaders, build teams and transform their corporate cultures. However, very little rigorous research has been conducted to determine the effectiveness of action learning. The authors…

  15. Regular bouncing cosmological solutions in effective actions in four dimensions

    NASA Astrophysics Data System (ADS)

    Constantinidis, C. P.; Fabris, J. C.; Furtado, R. G.; Picco, M.

    2000-02-01

    We study cosmological scenarios resulting from effective actions in four dimensions which are, under some assumptions, connected with multidimensional, supergravity and string theories. These effective actions are labeled by the parameters ω, the dilaton coupling constant, and n which establishes the coupling between the dilaton and a scalar field originating from the gauge field existing in the original theories. There is a large class of bouncing as well as Friedmann-like solutions. We investigate under which conditions bouncing regular solutions can be obtained. In the case of the string effective action, regularity is obtained through the inclusion of contributions from the Ramond-Ramond sector of superstring.

  16. Thermal effective action for 1+1 dimensional massive QED

    SciTech Connect

    Das, Ashok

    2010-12-15

    In continuation of our earlier proposal [A. Das and J. Frenkel, Phys. Lett. B 680, 195 (2009).] and [A. Das and J. Frenkel, Phys. Rev. D 80, 125039 (2009).] for evaluating thermal effective actions, we determine the exact fermion propagator in 1+1 dimensional massive QED. This propagator is used to derive the finite temperature effective action of the theory which generates systematically all the one loop Feynman amplitudes calculated in thermal perturbation theory. Various aspects of the effective action, including its imaginary part are discussed.

  17. Effect of chlorpromazine on the smg GDS action.

    PubMed

    Kim, Y S; Kikuchi, A; Takai, Y

    1992-02-14

    A stimulatory GDP/GTP exchange protein for smg p21 (smg GDS) stimulated the binding of guanosine 5'-(3-0-thio) triphosphate (GTP gamma S) to smg p21B. Chlorpromazine (CPZ) inhibited the smg GDS action in a manner competitive with smg GDS and in a manner noncompetitive with smg p21B. In spite of the inhibitory effect of CPZ on the smg GDS action, it counteracted the inhibition of the smg GDS action by acidic phospholipids. These results suggest that CPZ interacts with smg p21B, smg GDS, or both, and thereby inhibits the smg GDS action, and that CPZ also interacts with the acidic phospholipids and thereby counteracts their inhibitory effect on the smg GDS action.

  18. Age effects on rotational hand action.

    PubMed

    Varadhan, S K M; Zhang, Wei; Zatsiorsky, Vladimir M; Latash, Mark L

    2012-06-01

    We investigated age-related differences in finger coordination during rotational hand actions. Two hypotheses based on earlier studies were tested: higher safety margins and lower synergy indices were expected in the elderly. Young and elderly subjects held a handle instrumented with five six-component force sensors and performed discrete accurate pronation and supination movements. The weight of the system was counterbalanced with another load. Indices of synergies stabilizing salient performance variables, such as total normal force, total tangential force, moments produced by these forces, and total moment of force were computed at two levels of a hypothetical control hierarchy, at the virtual finger-thumb level and at the individual finger level. At each level, synergy indices reflected the normalized difference between the sum of the variances of elemental variables and variance of their combined output, both computed at comparable phases over repetitive trials. The elderly group performed the task slower and showed lower safety margins for the thumb during the rotation phase. Overall, the synergy indices were not lower in the elderly group. In several cases, these indices were significantly higher in the elderly than in the younger participants. Hence, both main hypotheses have been falsified. We interpret the unexpectedly low safety margins in the elderly as resulting from several factors such as increased force variability, impaired feed-forward control, and the fact that there was no danger of dropping the object. Our results suggest that in some natural tasks, such as the one used in this study, healthy elderly persons show no impairment, as compared to younger persons, in their ability to organize digits into synergies stabilizing salient performance variables.

  19. Quantum Corrections and Effective Action in Field Theory

    NASA Astrophysics Data System (ADS)

    Dalvit, Diego A. R.

    1998-07-01

    In this Thesis we study quantum corrections to the classical dynamics for mean values in field theory. To that end we make use of the formalism of the closed time path effective action to get real and causal equations of motion. We introduce a coarse grained effective action, which is useful in the study of phase transitions in field theory. We derive an exact renormalization group equation that describes how this action varies with the coarse graining scale. We develop different approximation methods to solve that equation, and we obtain non perturbative improvements to the effective potential for a self interacting scalar field theory. We also discuss the stochastic aspects contained in this action. On the other hand, using the effective action, we find low energy and large distance quantum corrections for the gravitational potential, treating relativity as an effective low energy theory. We include the effect of scalar fields, fermions and gravitons. The inclusion of metric fluctuations causes Einstein semiclassical equations to depend on the gauge fixing parameters, and they are therefore non physical. We solve this problem identifying as a physical observable the trayectory of a test particle. We explicitly show that the geodesic equation for such particle is independent of the arbitrary parameters of the gauge fixing.

  20. Effective action for noncommutative Bianchi I model

    SciTech Connect

    Rosenbaum, M.; Vergara, J. D.; Minzoni, A. A.

    2013-06-12

    Quantum Mechanics, as a mini-superspace of Field Theory has been assumed to provide physically relevant information on quantum processes in Field Theory. In the case of Quantum Gravity this would imply using Cosmological models to investigate quantum processes at distances of the order of the Planck scale. However because of the Stone-von Neuman Theorem, it is well known that quantization of Cosmological models by the Wheeler-DeWitt procedure in the context of a Heisenberg-Weyl group with piecewise continuous parameters leads irremediably to a volume singularity. In order to avoid this information catastrophe it has been suggested recently the need to introduce in an effective theory of the quantization some form of reticulation in 3-space. On the other hand, since in the geometry of the General Relativistic formulation of Gravitation space can not be visualized as some underlying static manifold in which the physical system evolves, it would be interesting to investigate whether the effective reticulation which removes the singularity in such simple cosmologies as the Bianchi models has a dynamical origin manifested by a noncommutativity of the generators of the Heisenberg-Weyl algebra, as would be expected from an operational point of view at the Planck length scale.

  1. Boldine action against the stannous chloride effect.

    PubMed

    Reiniger, I W; Ribeiro da Silva, C; Felzenszwalb, I; de Mattos, J C; de Oliveira, J F; da Silva Dantas, F J; Bezerra, R J; Caldeira-de-Araújo, A; Bernardo-Filho, M

    1999-12-15

    Peumus boldus extract has been used in popular medicine in the treatment of biliar litiase, hepatic insufficiency and liver congestion. Its effects are associated to the substance boldine that is present in its extract. In the present work, we evaluated the influence of boldine both in: (i) the structural conformation of a plasmid pUC 9.1 through gel electrophoresis analysis; and in (ii) the survival of the strain of Escherichia coli AB1157 submitted to reactive oxygen species (ROS), generated by a Fenton like reaction, induced by stannous chloride. Our results show a reduction of the lethal effect induced by stannous chloride on the survival of the E. coli culture in the presence of boldine. The supercoiled form of the plasmid is not modified by stannous chloride in the presence of boldine. We suggest that the protection induced by boldine could be explained by its anti-oxidant mechanism. In this way, the boldine could be reacting with stannous ions, protecting them against the oxidation and, consequently, avoiding the generation of ROS.

  2. Effective action for noncommutative Bianchi I model

    NASA Astrophysics Data System (ADS)

    Rosenbaum, M.; Vergara, J. D.; Minzoni, A. A.

    2013-06-01

    Quantum Mechanics, as a mini-superspace of Field Theory has been assumed to provide physically relevant information on quantum processes in Field Theory. In the case of Quantum Gravity this would imply using Cosmological models to investigate quantum processes at distances of the order of the Planck scale. However because of the Stone-von Neuman Theorem, it is well known that quantization of Cosmological models by the Wheeler-DeWitt procedure in the context of a Heisenberg-Weyl group with piecewise continuous parameters leads irremediably to a volume singularity. In order to avoid this information catastrophe it has been suggested recently the need to introduce in an effective theory of the quantization some form of reticulation in 3-space. On the other hand, since in the geometry of the General Relativistic formulation of Gravitation space can not be visualized as some underlying static manifold in which the physical system evolves, it would be interesting to investigate whether the effective reticulation which removes the singularity in such simple cosmologies as the Bianchi models has a dynamical origin manifested by a noncommutativity of the generators of the Heisenberg-Weyl algebra, as would be expected from an operational point of view at the Planck length scale.

  3. Effective action of softly broken supersymmetric theories

    SciTech Connect

    Nibbelink, Stefan Groot; Nyawelo, Tino S.

    2007-02-15

    We study the renormalization of (softly) broken supersymmetric theories at the one loop level in detail. We perform this analysis in a superspace approach in which the supersymmetry breaking interactions are parametrized using spurion insertions. We comment on the uniqueness of this parametrization. We compute the one loop renormalization of such theories by calculating superspace vacuum graphs with multiple spurion insertions. To perform this computation efficiently we develop algebraic properties of spurion operators, that naturally arise because the spurions are often surrounded by superspace projection operators. Our results are general apart from the restrictions that higher super covariant derivative terms and some finite effects due to noncommutativity of superfield dependent mass matrices are ignored. One of the soft potentials induces renormalization of the Kaehler potential.

  4. Non-dissipative hydrodynamics: effective actions versus entropy current

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Jyotirmoy; Bhattacharyya, Sayantani; Rangamani, Mukund

    2013-02-01

    While conventional hydrodynamics incorporating dissipative effects is hard to derive from an action principle, it is nevertheless possible to construct classical actions when the dissipative terms are switched off. In this note we undertake a systematic exploration of such constructions from an effective field theory approach and argue for the existence of non-trivial second order non-dissipative hydrodynamics involving pure energy-momentum transport. We find these fluids to be characterized by five second-order transport coefficients based on the effective action (a three parameter family is Weyl invariant). On the other hand since all flows of such fluids are non-dissipative, they entail zero entropy production; one can therefore understand them using the entropy current formalism which has provided much insight into hydrodynamic transport. An analysis of the most general stress tensor with zero entropy production however turns out to give a seven parameter family of non-dissipative hydrodynamics (a four parameter sub-family being Weyl invariant). The non-dissipative fluids derived from the effective action approach are a special case of the fluid dynamics constrained by conservation of the entropy current. We speculate on the reasons for the mismatch and potential limitations of the effective action approach.

  5. 16 CFR 1.89 - Effect on prior actions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Effect on prior actions. 1.89 Section 1.89 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL PROCEDURES Procedures for Implementation of the National Environmental Policy Act of 1969 § 1.89 Effect...

  6. 16 CFR 1.89 - Effect on prior actions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Effect on prior actions. 1.89 Section 1.89 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL PROCEDURES Procedures for Implementation of the National Environmental Policy Act of 1969 § 1.89 Effect...

  7. 16 CFR 1.89 - Effect on prior actions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Effect on prior actions. 1.89 Section 1.89 Commercial Practices FEDERAL TRADE COMMISSION ORGANIZATION, PROCEDURES AND RULES OF PRACTICE GENERAL PROCEDURES Procedures for Implementation of the National Environmental Policy Act of 1969 § 1.89 Effect...

  8. Power effects on cognitive control: Turning conflict into action.

    PubMed

    Schmid, Petra C; Kleiman, Tali; Amodio, David M

    2015-06-01

    Power is known to promote effective goal pursuit, especially when it requires one to overcome distractions or bias. We proposed that this effect involves the ability to engage and implement cognitive control. In Study 1, we demonstrated that power enhances behavioral performance on a response conflict task and that it does so by enhancing controlled processing rather than by reducing automatic processing. In Study 2, we used an event-related potential index of anterior cingulate activity to test whether power effects on control were due to enhanced conflict sensitivity or action implementation. Power did not significantly affect neural sensitivity to conflict; rather, high power was associated with a stronger link between conflict processing and intended action, relative to low power. These findings suggest a new perspective on how social factors can affect controlled processing and offer new evidence regarding the transition between conflict detection and the implementation of action control.

  9. Fully quantum state-resolved inelastic scattering between He and NO(X (2)Pi).

    PubMed

    Kłos, J; Aoiz, F J; Verdasco, J E; Brouard, M; Marinakis, S; Stolte, S

    2007-07-21

    Quantum mechanical close-coupling calculations have been used to obtain fully quantum state-resolved differential cross sections and opacity functions for the rotationally inelastic collisions of NO(X (2)Pi) with He at collision energies of 63 and 147 meV using the most recent ab initio potential energy surfaces of Kłos et al. [J. Chem. Phys. 112, 2195 (2000)]. Double peaks observed in the Lambda-doublet resolved differential cross sections are shown to be related to the presence of analogous peaks in the corresponding opacity functions. These structures can be linked directly to a specific expansion term in the potential, and reflect the fact that NO is not quite homonuclear.

  10. A second-order focusing electrostatic toroidal electron spectrometer with 2pi radian collection.

    PubMed

    Khursheed, Anjam; Hoang, Hung Quang

    2008-12-01

    This paper presents a toroidal electron energy spectrometer designed to capture electrons in the full 2pi azimuthal angular direction while at the same time having second-order focusing optics. Simulation results based upon direct ray tracing predict that the relative energy resolution of the spectrometer will be 0.146% and 0.0188% at input angular spreads of +/- 6 degrees and +/- 3 degrees, respectively, comparable to the theoretically best resolution of the cylindrical mirror analyzer (CMA), and an order of magnitude better than existing toroidal spectrometers. Also predicted for the spectrometer is a parallel energy acquisition mode of operation, where the energy bandwidth is expected to be > +/- 10% (20% total) of the pass energy. The spectrometer is designed to allow for retardation of the pass energy without the need to incorporate auxiliary lenses.

  11. Theoretical study of the dipole moment function of OH(X 2Pi)

    NASA Technical Reports Server (NTRS)

    Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.; Taylor, Peter R.

    1987-01-01

    A complete theoretical electric dipole moment function mu(r) is computed for OH(X 2Pi) at the full configuration-interaction (FCI) level for DZP + diffuse Gaussian basis set. The energy and dipole moment are also determined with 2d functions on oxygen at seven r values. The following methods are compared to the FCI for both the oxygen 1d and 2d basis sets: single-reference singles-plus-doubles configuration interaction (SDCI), SDCI with Davidson's correction, the coupled pair functional approach (CPF) and a modified form of CPF, CASSCF, and CASSCF-MRSDCI, and the external contracted CI(CCI) method. The dipole moments are evaluated both as an expectation value and by finite-field methods. The results support the superiority of evaluating the dipole moment as an energy derivative rather than as an expectation value.

  12. Derivative expansion at small mass for the spinor effective action

    SciTech Connect

    Dunne, Gerald V.; Huet, Adolfo; Hur, Jin; Min, Hyunsoo

    2011-05-15

    We study the small-mass limit of the one-loop spinor effective action, comparing the derivative expansion approximation with exact numerical results that are obtained from an extension to spinor theories of the partial-wave cutoff method. In this approach, one can compute numerically the renormalized one-loop effective action for radially separable gauge field background fields in spinor QED. We highlight an important difference between the small-mass limit of the derivative expansion for spinor and scalar theories.

  13. Interference effect of body shadow in action control.

    PubMed

    Badets, Arnaud; Toussaint, Lucette; Blandin, Yannick; Bidet-Ildei, Christel

    2013-01-01

    Observing actions performed by other persons can subsequently influence our own motor behaviours. However, it is unknown whether the shadows cast by such actions can also have an impact on the observers' actions. Here we show that the mere observation of a cast shadow can influence imitative behaviours. Specifically, participants were shown a hand picture and its associated cast shadow in a neutral position. In a 'compatible trial' the hand and the shadow that followed were turned in the same open or closed direction, whereas in an 'incompatible trial' the hand and the shadow were turned in different directions. We contrasted two experimental conditions: (i) 'hand-shadow' in which participants observed a hand and its cast shadow (the hand covered the shadow); (ii) 'hand-hand' in which participants observed a hand and another black hand (the shadow covered the hand). The participants' task was to imitate (ie by closing or opening their own hands) the hand or the cast shadow of an action. For both conditions results revealed interference (ie longer response latencies) for incompatible trials. This suggests for the first time that the mere observation of a cast shadow of a hand can influence imitative behaviours. However, time courses of the response latencies revealed that imitative effect in the hand-shadow condition was different than the imitative effect in the hand-hand condition. Therefore, we suggest considering the cast shadow of an action as an important feature during motor control for humans.

  14. Action Research: Effective Marketing Strategies for a Blended University Program

    ERIC Educational Resources Information Center

    Cook, Ruth Gannon; Ley, Kathryn

    2008-01-01

    This action research study investigated a marketing plan based on collaboration among a program faculty team and other organizational units for a graduate professional program. From its inception through the second year of operation, program enrollment increased due to the marketing plan based on an effective approach grounded in simple marketing…

  15. Effects of Action Relations on the Configural Coding between Objects

    ERIC Educational Resources Information Center

    Riddoch, M. J.; Pippard, B.; Booth, L.; Rickell, J.; Summers, J.; Brownson, A.; Humphreys, G. W.

    2011-01-01

    Configural coding is known to take place between the parts of individual objects but has never been shown between separate objects. We provide novel evidence here for configural coding between separate objects through a study of the effects of action relations between objects on extinction. Patients showing visual extinction were presented with…

  16. Long-Term Effects of the Positive Action Program.

    ERIC Educational Resources Information Center

    Flay, Brian R.; Allred, Carol G.

    2003-01-01

    Used a matched-schools design, school-level achievement, and disciplinary data to evaluate the effectiveness of the elementary-level Positive Action program on students' performance and behavior over time. Results indicated that program participation improved student behavior, school involvement, and academic achievement into high school. The…

  17. One Loop Superstring Effective Actions and d = 4 Supergravity

    SciTech Connect

    Moura, Filipe

    2008-06-25

    We review our recent work on the existence of a new independent R{sup 4} term, at one loop, in the type IIA and heterotic effective actions, after reduction to four dimensions, besides the usual square of the Bel-Robinson tensor. We discuss its supersymmetrization.

  18. Finiteness of the Coulomb gauge QCD perturbative effective action

    SciTech Connect

    Andraši, A.; Taylor, J.C.

    2015-05-15

    At 2-loop order in the Coulomb gauge, individual Feynman graphs contributing to the effective action have energy divergences. It is proved that these cancel in suitable combinations of graphs. This has previously been shown only for transverse external fields. The calculation results in a generalization of the Christ–Lee term which was inserted into the Hamiltonian.

  19. Probing Competitive Noncovalent Interactions: Resonance Enhanced Two-Photon Ionization (R2PI) Spectroscopy of Haloaromatic Clusters

    NASA Astrophysics Data System (ADS)

    Nyambo, Silver; Muzangwa, Lloyd; Uhler, Brandon; Reid, Scott A.

    2013-06-01

    Non-covalent interactions in bromobenzene have been studied here using resonance two-photon ionization (R2PI) spectroscopy combined with a linear TOF-mass spectrometer. Bromobenzene clusters were created in a supersonic expansion with helium as a carrier gas. The molecules were excited and ionized from the ground state in a two stage process. The general trend observed in the R2PI spectra of all the clusters is the broadness and a red-shift relative to the monomer absorption. Optimized dimer and trimer structures were calculated at the M06-2x/aug-cc-pVDZ level, which show that π-stacked and C-H/π interactions are most important in these clusters. TD-DFT calculations of the different cluster conformers have been carried out to assess the geometry changes active upon electronic excitation. The theoretical studies are helpful in explaining trends observed in the R2PI spectra.

  20. Action video game training reduces the Simon Effect.

    PubMed

    Hutchinson, Claire V; Barrett, Doug J K; Nitka, Aleksander; Raynes, Kerry

    2016-04-01

    A number of studies have shown that training on action video games improves various aspects of visual cognition including selective attention and inhibitory control. Here, we demonstrate that action video game play can also reduce the Simon Effect, and, hence, may have the potential to improve response selection during the planning and execution of goal-directed action. Non-game-players were randomly assigned to one of four groups; two trained on a first-person-shooter game (Call of Duty) on either Microsoft Xbox or Nintendo DS, one trained on a visual training game for Nintendo DS, and a control group who received no training. Response times were used to contrast performance before and after training on a behavioral assay designed to manipulate stimulus-response compatibility (the Simon Task). The results revealed significantly faster response times and a reduced cost of stimulus-response incompatibility in the groups trained on the first-person-shooter game. No benefit of training was observed in the control group or the group trained on the visual training game. These findings are consistent with previous evidence that action game play elicits plastic changes in the neural circuits that serve attentional control, and suggest training may facilitate goal-directed action by improving players' ability to resolve conflict during response selection and execution.

  1. QED effective action at finite temperature and density

    NASA Astrophysics Data System (ADS)

    Elmfors, Per; Persson, David; Skagerstam, Bo-Sture

    1993-07-01

    Results are presented of calculations of the QED effective action at finite temperature and density to all orders in an external homogeneous and time-independent magnetic field, in the weak coupling limit. The free energy, obtained explicitly, exhibits the expected de Haas-van Alphen oscillations. An effective coupling at finite temperature and density is derived in a closed form and is compared with renormalization group results.

  2. A correlated ab initio study of the A2 pi <-- X2 sigma+ transition in MgCCH.

    PubMed

    Woon, D E

    1997-08-01

    The A2 pi <-- X2 sigma+ transition in MgCCH was studied with correlation consistent basis sets and single- and multireference correlation methods. The A2 pi excited state was characterized in detail; the x2 sigma+ ground state has been described elsewhere recently. The estimated complete basis set (CBS) limits for valence correlation, including zero-point energy corrections, are 22668, 23191, and 22795 for the RCCSD(T), MRCI, and MRCI + Q methods, respectively. A core-valence correction of +162 cm-1 shifts the RCCSD(T) value to 22830 cm-1, in good agreement with the experimental result of 22807 cm-1.

  3. Rotational dependence of the proton-transfer reaction HBr{sup +}+ CO{sub 2}{yields} HOCO{sup +}+ Br. II. Comparison of HBr{sup +} ({sup 2}{Pi}{sub 3/2}) and HBr{sup +} ({sup 2}{Pi}{sub 1/2})

    SciTech Connect

    Paetow, Lisa; Unger, Franziska; Beutel, Bernd; Weitzel, Karl-Michael

    2010-12-21

    The effects of reactant ion rotational excitation on the exothermic proton-transfer reactions of HBr{sup +}({sup 2}{Pi}{sub 1/2}) and DBr{sup +}({sup 2}{Pi}{sub 1/2}), respectively, with CO{sub 2} were studied in a guided ion beam apparatus. Cross sections are presented for collision energies in the center of mass system E{sub c.m.} in the range of 0.23 to 1.90 eV. The HBr{sup +}/DBr{sup +} ions were prepared in a state-selective manner by resonance enhanced multiphoton ionization. The mean rotational energy was varied from 3.4 to 46.8 meV for HBr{sup +}({sup 2}{Pi}{sub 1/2}) and from 1.8 to 40.9 meV for DBr{sup +}({sup 2}{Pi}{sub 1/2}). Both reactions studied are inhibited by collision energy, as expected for exothermic reactions. For all collision energies considered, the cross section decreases with increasing rotational energy of the ion, but the degree of the rotational dependence differs depending on the collision energy. For E{sub c.m.}= 0.31 eV, the cross sections of the deuteron transfer are significantly larger than those of the proton transfer. For higher E{sub c.m.} they differ very little. The current results for the exothermic proton transfer are systematically compared to previously published data for the endothermic proton transfer starting from HBr{sup +}({sup 2}{Pi}{sub 3/2}) [L. Paetow et al., J. Chem. Phys. 132, 174305 (2010)]. Additional new data regarding the latter reaction are presented to further confirm the conclusions. The dependences on rotational excitation found cannot be explained by the corresponding change in the total energy of the system. For both the endothermic and the exothermic reaction, the cross section is maximized for the smallest rotational energy, at least well above the threshold.

  4. Evaluation of 2-PI liquid scintillation whole body counter using MCNP

    NASA Astrophysics Data System (ADS)

    Mireles-Garcia, Fernando

    The 2-pi liquid scintillation whole body counter (WBC) at the University of Missouri-Columbia has been evaluated using MCNP-4A (a general Monte Carlo Neutron-Photon transport code, Version 4A). This facility is of importance to a wide variety of applications, such as determination of body fat content in human and animal subjects and measurement of radioactive tracers in animals. Phantoms and mathematical models were used in this research to upgrade the calibration procedures of the WBC. Since the existing protocol assumes a simple efficiency calibration based only upon body mass, it does not account for body shape and gives no methodology for placement of the subject below the detectors. Mathematical models were developed to calculate geometry efficiency for a variety of subjects and geometries utilizing the MCNP-4A transport code. Comparison of the results from simulation with experimental data shows excellent agreement not only in the shape of the curves as a function of subject position but also in absolute magnitude. In the case of the WBC and a phantom consisting of 40 liters of water containing 800 grams of sp+K the error in the magnitude is within 6%, which is easily attributable to the experimental calibration of the detectors. The efficiency of the WBC has been calculated for different weights for modified Adam-E through Adam-L model geometries; hence weight and shape can be modeled carefully and correction can be applied to actual human measurements based upon this work.

  5. Subliminal Priming of Actions Influences Sense of Control over Effects of Action

    ERIC Educational Resources Information Center

    Wenke, Dorit; Fleming, Stephen M.; Haggard, Patrick

    2010-01-01

    The experience of controlling one's own actions, and through them events in the outside world, is a pervasive feature of human mental life. Two experiments investigated the relation between this sense of control and the internal processes involved in action selection and cognitive control. Action selection was manipulated by subliminally priming…

  6. Covariant effective action for loop quantum cosmology a la Palatini

    SciTech Connect

    Olmo, Gonzalo J.; Singh, Parampreet E-mail: psingh@perimeterinstitute.ca

    2009-01-15

    In loop quantum cosmology, non-perturbative quantum gravity effects lead to the resolution of the big bang singularity by a quantum bounce without introducing any new degrees of freedom. Though fundamentally discrete, the theory admits a continuum description in terms of an effective Hamiltonian. Here we provide an algorithm to obtain the corresponding effective action, establishing in this way the covariance of the theory for the first time. This result provides new insights on the continuum properties of the discrete structure of quantum geometry and opens new avenues to extract physical predictions such as those related to gauge invariant cosmological perturbations.

  7. The "HER2-PI3K/Akt-FASN Axis" regulated malignant phenotype of colorectal cancer cells.

    PubMed

    Li, Nan; Bu, Xiaodong; Wu, Peng; Wu, Pingping; Huang, Peilin

    2012-04-01

    Recent evidence suggests that HER2 (ErbB2; Her-2/neu) and the related PI3K/Akt signaling pathway substantially affect the malignant phenotype of colorectal cancer cells. Moreover, fatty acid synthase (FASN), which mediates de-novo fatty acid synthesis, is crucially important in the carcinogenesis process of a variety of cancers, including colorectal cancer. The purpose of this study was to investigate the malignant phenotype regulation of colorectal cancer cells via the "HER2-PI3K/Akt-FASN axis". Caco-2 cells with high expression of HER2 and FASN and high transfection efficiency were selected for functional characterization. The cells were transfected with either HER2-specific RNAi plasmid or negative control RNAi plasmid, followed by Q-RT-PCR and western blot assays to examine expression of HER2, PI3K, Akt, and FASN. MTT and colony-formation assays were used to assess proliferation. Migration was investigated by use of the transwell assay, and apoptosis and cell cycle were assayed by use of flow cytometry. Expression of HER2, PI3K, Akt, and FASN were downregulated when HER2 was silenced. Proliferation decreased after downregulation of HER2, which was consistent with increased apoptosis. Migration of HER2-silenced cells was also impaired. Loss of HER2 inhibits the activity of the "HER2-PI3K/Akt-FASN axis" of Caco-2 cells, and reduced activity of this axis alters the malignant behavior of Caco-2 cells.

  8. A Comparison of 2pi and 4pi Photometric Testing of Directional and Omnidirectional Sources in an Integrating Sphere

    SciTech Connect

    Richman, Eric E.; Merzouk, Massine B.

    2014-06-12

    A Comparison of 2pi and 4pi Photometric Testing of Directional and Omnidirectional Sources in an Integrating Sphere. These data will help determine if differences in methods should be addresed in test methods specifically for LED products but applicable to other technologies as well

  9. Gauge symmetry breaking in gravity and auxiliary effective action

    NASA Astrophysics Data System (ADS)

    Akhavan, Amin

    2017-02-01

    In the context of the covariant symmetry breaking in gravity, we study the quantum aspect of Chamseddine-Mukhanov model by making use of path integral method. Utilizing one of the gauge fixing constraints, we remove the specific ghost degree of freedom. In continuation, we define an auxiliary effective action. Introducing an auxiliary field, we will have a new dynamic field in addition to the fundamental field.

  10. Modafinil: a review of neurochemical actions and effects on cognition.

    PubMed

    Minzenberg, Michael J; Carter, Cameron S

    2008-06-01

    Modafinil (2-[(Diphenylmethyl) sulfinyl] acetamide, Provigil) is an FDA-approved medication with wake-promoting properties. Pre-clinical studies of modafinil suggest a complex profile of neurochemical and behavioral effects, distinct from those of amphetamine. In addition, modafinil shows initial promise for a variety of off-label indications in psychiatry, including treatment-resistant depression, attention-deficit/hyperactivity disorder, and schizophrenia. Cognitive dysfunction may be a particularly important emerging treatment target for modafinil, across these and other neuropsychiatric disorders. We aimed to comprehensively review the empirical literature on neurochemical actions of modafinil, and effects on cognition in animal models, healthy adult humans, and clinical populations. We searched PubMed with the search term 'modafinil' and reviewed all English-language articles for neurochemical, neurophysiological, cognitive, or information-processing experimental measures. We additionally summarized the pharmacokinetic profile of modafinil and clinical efficacy in psychiatric patients. Modafinil exhibits robust effects on catecholamines, serotonin, glutamate, gamma amino-butyric acid, orexin, and histamine systems in the brain. Many of these effects may be secondary to catecholamine effects, with some selectivity for cortical over subcortical sites of action. In addition, modafinil (at well-tolerated doses) improves function in several cognitive domains, including working memory and episodic memory, and other processes dependent on prefrontal cortex and cognitive control. These effects are observed in rodents, healthy adults, and across several psychiatric disorders. Furthermore, modafinil appears to be well-tolerated, with a low rate of adverse events and a low liability to abuse. Modafinil has a number of neurochemical actions in the brain, which may be related to primary effects on catecholaminergic systems. These effects are in general advantageous for

  11. Kaon condensation in CFL quark matter, the Goldstone theorem, and the 2PI Hartree approximation

    SciTech Connect

    Leganger, Lars E.

    2011-05-23

    At very high densities, QCD is in the color-flavor-locked phase, which is a color-superconducting phase. The diquark condensates break chiral symmetry in the same way as it is broken in vacuum QCD and gives rise to an octet of pseudo-Goldstone bosons and a superfluid mode. The lightest of these are the charged and neutral kaons. For energies below the superconducting gap, the kaons are described by an O(2)xO(2)-symmetric effective scalar field theory with chemical potentials. We use this effective theory to study Bose-condensation of kaons and their properties as functions of the temperature and the chemical potentials. We use the 2-particle irreducible effective action formalism in the Hartree approximation. The renormalization of the gap equations and the effective potential is studied in detail and we show that the counterterms are independent of temperature and chemical potentials. We determine the phase diagram and the medium-dependent quasiparticle masses. It is shown that the Goldstone theorem is satisfied to a very good approximation.

  12. Brane Effective Actions, Kappa-Symmetry and Applications

    NASA Astrophysics Data System (ADS)

    Simón, Joan

    2012-12-01

    This is a review on brane effective actions, their symmetries and some of their applications. Its first part covers the Green-Schwarz formulation of single M- and D-brane effective actions focusing on kinematical aspects: the identification of their degrees of freedom, the importance of world volume diffeomorphisms and kappa symmetry to achieve manifest spacetime covariance and supersymmetry, and the explicit construction of such actions in arbitrary on-shell supergravity backgrounds. Its second part deals with applications. First, the use of kappa symmetry to determine supersymmetric world volume solitons. This includes their explicit construction in flat and curved backgrounds, their interpretation as Bogomol’nyi-Prasad-Sommerfield (BPS) states carrying (topological) charges in the supersymmetry algebra and the connection between supersymmetry and Hamiltonian BPS bounds. When available, I emphasise the use of these solitons as constituents in microscopic models of black holes. Second, the use of probe approximations to infer about the non-trivial dynamics of strongly-coupled gauge theories using the anti de Sitter/conformal field theory (AdS/CFT) correspondence. This includes expectation values of Wilson loop operators, spectrum information and the general use of D-brane probes to approximate the dynamics of systems with small number of degrees of freedom interacting with larger systems allowing a dual gravitational description. Its final part briefly discusses effective actions for N D-branes and M2-branes. This includes both Super-Yang-Mills theories, their higher-order corrections and partial results in covariantising these couplings to curved backgrounds, and the more recent supersymmetric Chern-Simons matter theories describing M2-branes using field theory, brane constructions and 3-algebra considerations.

  13. Using the Psychology of Language to Effectively Communicate Actionable Science

    NASA Astrophysics Data System (ADS)

    Hall, J. M.

    2014-12-01

    The words used to articulate science can have as significant a psychological impact on public perception as the data itself. It is therefore essential to utilize language that not only accurately relates the scientific information, but also effectively conveys a message that is congruent with the presenter's motivation for expressing the data. This is especially relevant for environmental subjects that are surrounded by emotionally charged, political discourses. For example are terms like catastrophe and disaster; while these words may accurately illustrate impartial scientific data, they will likely trigger psychological responses in audiences such as fear or denial that have a detrimental impact on the human decision making process. I propose a set of 5 key principles to assist in communicating data to the general public that both support the transfer of ideas and the presenter's intended psychological impact. 1) Articulate the underlying intentions that motivate the communication of data in a transparent manner 2) Use language congruent with the presenter's stated intentions 3) Maintain a neutral, non-judgmental attitude towards the complex human psychological and emotional dynamics present in a target audience 4) Demonstrate acceptance and compassion when analyzing past and present human actions that adversely affect the environment 5) Develop a perspective of non-attachment when proposing future actions and/or consequences of current human behaviors. The application of these 5 principles provides a framework to move from our current understanding of problems and solutions to effective physical action that allows us to gracefully adapt with our ever changing planet.

  14. The effect of mechanical damping loads on disabling action tremor.

    PubMed

    Aisen, M L; Arnold, A; Baiges, I; Maxwell, S; Rosen, M

    1993-07-01

    Patients with severe action tremor have uncontrollable, relatively rapid oscillatory motion super-imposed on otherwise useable slower voluntary motor activity. Because a mechanical damper produces an opposing force proportional to velocity, applying damping loads to tremorous limbs should attenuate the (high-velocity) tremor component of movement while permitting the slower purposeful portion to proceed relatively unopposed. In this study, the effect of upper extremity damping in three degrees of freedom was examined in 10 patients with cerebellar action tremor due to multiple sclerosis or traumatic brain injury. Variable amounts of damping were applied by prototype energy-dissipating orthoses which generated resistive viscous loads by means of computer-controlled magnetic particle brakes. All patients experienced statistically and functionally significant tremor reduction with the application of damping.

  15. Highly effective action from large N gauge fields

    NASA Astrophysics Data System (ADS)

    Yang, Hyun Seok

    2014-10-01

    Recently Schwarz put forward a conjecture that the world-volume action of a probe D3-brane in an AdS5×S5 background of type IIB superstring theory can be reinterpreted as the highly effective action (HEA) of four-dimensional N =4 superconformal field theory on the Coulomb branch. We argue that the HEA can be derived from the noncommutative (NC) field theory representation of the AdS/CFT correspondence and the Seiberg-Witten (SW) map defining a spacetime field redefinition between ordinary and NC gauge fields. It is based only on the well-known facts that the master fields of large N matrices are higher-dimensional NC U(1) gauge fields and the SW map is a local coordinate transformation eliminating U(1) gauge fields known as the Darboux theorem in symplectic geometry.

  16. The production of cosmogenic nuclides by GCR-particles for 2 pi exposure geometries

    NASA Astrophysics Data System (ADS)

    Leya, I.; Neumann, S.; Wieler, R.; Michel, R.

    2001-11-01

    We present a purely physical model for the calculation of depth dependent production rates in 2 pi exposure geometries by galactic cosmic rays (GCR). Besides the spectra of primary and secondary particles and the excitation functions of the underlying nuclear reactions, the model is based on the integral number of GCR particles in the lunar orbit. We derived this value from adjusting modeled depth profiles for 10Be, 26Al, and 53Mn to measured data from the Apollo 15 drill core. The J0,GCR-value of 4.54 cm-2 s-1 and the solar modulation parameter of M = 490 MeV determined this way for 1 AU is in reasonable agreement with the J0,GCR-value derived recently for the meteoroid orbits (Leya et al., 2000b). We also show that the mean GCR proton spectrum in the lunar orbit has not changed substantially over about the last 10 Myr. For the major target elements we present depth dependent production rates for 10Be, 14C, 26Al, 36Cl and 53Mn, as well as for the rare gas isotopes 20,21,22Ne. In addition we present production rates for 36,38Ar from Fe and Ni. The new results are consistent with the data for stony meteoroids presented recently by our group (Leya et al., 2000b), but for the rare gas isotopes the new production rates sometimes differ significantly from earlier estimates. The applicability of the 22Ne/21Ne ratio as a shielding parameter is also discussed.

  17. The effects of an action's "age-of-acquisition" on action-sentence processing.

    PubMed

    Gilead, Michael; Liberman, Nira; Maril, Anat

    2016-11-01

    How does our brain allow us comprehend abstract/symbolic descriptions of human action? Whereas past research suggested that processing action language relies on sensorimotor brain regions, recent work suggests that sensorimotor activation depends on participants' task goals, such that focusing on abstract (vs. concrete) aspects of an action activates "default mode network" (rather than sensorimotor) regions. Following a Piagetian framework, we hypothesized that for actions acquired at an age wherein abstract/symbolic cognition is fully-developed, even when participants focus on the concrete aspects of an action, they should retrieve abstract-symbolic mental representations. In two studies, participants processed the concrete (i.e., "how") and abstract (i.e., "why") aspects of late-acquired and early-acquired actions. Consistent with previous research, focusing on the abstract (vs. concrete) aspects of an action resulted in greater activation in the "default mode network". Importantly, the activation in these regions was higher when processing later-acquired (vs. earlier acquired) actions-also when participants' goal was to focus on the concrete aspects of the action. We discuss the implications of the current findings to research on the involvement of concrete representations in abstract cognition.

  18. Time-dependent quantum study of H(2S) + FO(2Pi) --> OH(2Pi) + F(2P) reaction on the 1(3)A' and 1(3)A'' states.

    PubMed

    Gogtas, Fahrettin; Tutuk, Rukiye; Kurban, Mustafa

    2010-11-15

    The dynamics of the H((2)S) + FO((2)Pi) --> OH((2)Pi) + F((2)P) reaction on the adiabatic potential energy surface of the 1(3)A' and 1(3)A'' states is investigated. The initial state selected reaction probabilities for total angular momentum J = 0 have been calculated by using the quantum mechanical real wave packet method. The integral cross sections and initial state selected reaction rate constants have been obtained from the corresponding J = 0 reaction probabilities by means of the simple J-Shifting technique. The initial state-selected reaction probabilities and reaction cross section do not manifest any sharp oscillations and the initial state selected reaction rate constants are sensitive to the temperature.

  19. Laxative effects and mechanism of action of Brazilian green propolis

    PubMed Central

    2012-01-01

    Background Brazilian green propolis is reported to have wide range of biological properties including antibacterial, anti-inflammatory, anti-influenza, and antioxidant activities. In the digestive system, a protective effect of propolis on gastric ulcer has been reported, but a laxative effect has not yet been reported. We investigated the effect and the mechanism of action of water and ethanol extracts of Brazilian green propolis. Methods We examined the laxative effect of propolis on stool frequency by administering orally an ethanol extract of propolis (EEP) or a water extract of propolis (WEP) at 10, 50, 100, or 500 mg/kg to normal mice. We then investigated the effects of propolis using constipation model mice induced by two types of drugs, loperamide (a μ opioid receptor agonist) and clonidine (an α-2 adrenergic receptor agonist). We also investigated the effects of WEP on gastrointestinal transit and contractional tension of the ileum to uncover the mechanism of action of WEP. Results Treatment with WEP, but not with EEP, significantly increased the weight of stools (p<0.01 at 500 mg/kg). WEP treatment significantly restored stool frequency and stool weight in clonidine-induced constipation model mice, but not in loperamide-induced constipation model mice. WEP treatment did not affect gastro-intestinal transit, but significantly increased the contractional tension of the isolated ileum of guinea pigs. This increase was inhibited by an acetylcholine receptor antagonist (atropine), but not by a 5-HT receptor antagonist (GR113808). Conclusion These findings indicate that WEP has laxative effects both in normal mice and in clonidine-induced constipation model mice. The laxative effects of WEP might be mediated by increased contractional tension of the ileum exerted at least in part via activation of an acetylcholine receptor. PMID:23088672

  20. Yang-Mills effective action at high temperature

    NASA Astrophysics Data System (ADS)

    Oswald, M.

    2005-06-01

    Yang-Mills theory undergoes a transition from a confined to a deconfined phase in the intermediate temperature regime, where perturbation theory fails. In order to approach this phase transition from the high temperature side we study the effective action for the eigenvalues of the order parameter, the Polyakov loop, in the whole range of its possible variation. By means of a covariant derivative expansion we integrate out fast varying quantum fluctuations around background gluon fields and assume that these are slowly varying, but that the amplitude of A4 is arbitrary. Our results can be used to study correlation functions of the order parameter at high temperatures.

  1. Bending effects on lasing action of semiconductor nanowires.

    PubMed

    Yang, Weisong; Ma, Yaoguang; Wang, Yipei; Meng, Chao; Wu, Xiaoqin; Ye, Yu; Dai, Lun; Tong, Limin; Liu, Xu; Yang, Qing

    2013-01-28

    High flexibility has been one of advantages for one-dimensional semiconductor nanowires (NWs) in wide application of nanoscale integrated circuits. We investigate the bending effects on lasing action of CdSe NWs. Threshold increases and differential efficiency decreases gradually when we decrease the bending radius step by step. Red shift and mode reduction in the output spectra are also observed. The bending loss of laser oscillation is considerably larger than that of photoluminescence (PL), and both show the exponential relationship with the bending radius. Diameter and mode dependent bending losses are investigated. Furthermore, the polarizations of output can be modulated linearly by bending the NWs into different angles continuously.

  2. Theory and renormalization of the gauge-invariant effective action

    NASA Astrophysics Data System (ADS)

    Hart, C. F.

    1983-10-01

    The different methods for constructing a gauge-invariant effective action (GIEA) for quantum non-Abelian gauge field theories proposed by 't Hooft, DeWitt, Boulware, and Abbott are all shown to be equivalent. In the course of proving this equivalence we show how to extend the usual background-field method so as to construct what may be considered the prototypical GIEA and discuss in some detail the invariance and gauge transformation properties of both the usual theory and the new theory using the GIEA. All solutions to the GIEA field equations are shown to be physical-being solutions to the usual field equations with an arbitrary gauge condition. The renormalization program based upon the GIEA is shown to differ from the standard theory and we outline the modifications which are needed in the present proof of renormalizability. In particular we prove that the physical renormalization is independent of any gauge-fixing choice. Finally, we prove that the S-matrix elements derived from the GIEA for an arbitrary background-field solution to the field equations are the same as those derived using the usual effective action.

  3. Observation of Simple Intransitive Actions: The Effect of Familiarity

    PubMed Central

    Plata Bello, Julio; Modroño, Cristián; Marcano, Francisco; González–Mora, José Luis

    2013-01-01

    Introduction Humans are more familiar with index – thumb than with any other finger to thumb grasping. The effect of familiarity has been previously tested with complex, specialized and/or transitive movements, but not with simple intransitive ones. The aim of this study is to evaluate brain activity patterns during the observation of simple and intransitive finger movements with differing degrees of familiarity. Methodology A functional Magnetic Resonance Imaging (fMRI) study was performed using a paradigm consisting of the observation of 4 videos showing a finger opposition task between the thumb and the other fingers (index, middle, ring and little) in a repetitive manner with a fixed frequency (1 Hz). This movement is considered as the pantomime of a precision grasping action. Results Significant activity was identified in the bilateral Inferior Parietal Lobule and premotor regions with the selected level of significance (FDR [False Discovery Rate] = 0.01). The extent of the activation in both regions tended to decrease when the finger that performed the action was further from the thumb. More specifically, this effect showed a linear trend (index>middle>ring>little) in the right parietal and premotor regions. Conclusions The observation of less familiar simple intransitive movements produces less activation of parietal and premotor areas than familiar ones. The most important implication of this study is the identification of differences in brain activity during the observation of simple intransitive movements with different degrees of familiarity. PMID:24073213

  4. Effects of photodynamic action on respiration in nonphosphorylating mitochondria.

    PubMed

    Salet, C; Moreno, G; Ricchelli, F

    1998-10-15

    We have studied the effects of singlet oxygen produced by photodynamic action on respiration in nonphosphorylating mitochondria (state 4). Isolated rat liver mitochondria were incubated with 3 microM hematoporphyrin and irradiated at 365 nm with a fluence rate of 25 W/m2. After short durations of irradiation, state 4 respiration with beta-hydroxybutyrate as substrate increases while respiration with succinate is negligibly affected. When mitochondria have been uncoupled with carbonylcyanide-p-trifluoromethoxyphenyl hydrazone before irradiation, no change occurs in beta-hydroxybutyrate-driven respiration, while succinate-driven respiration strongly decreases. Stimulation of state 4 NADH respiration cannot be explained by slippage of the NADH ubiquinone oxidoreductase because the stoichiometry of the redox pump was found insensitive to photodynamic action. In the light of the metabolite theory for linear enzymatic chains applied to state 4 respiration (Brand et al., Biochem. J. 255, 535-539, 1988), these results suggest that stimulation of NADH respiration is simply due to an increase of membrane leaks which occurs after irradiation. In the case of succinate-driven respiration, a strong inhibition of succinate dehydrogenase activity has been demonstrated after irradiation. It can be suggested that this inhibition introduces a negative control coefficient over state 4 respiration, counterbalancing the effects due to leakage.

  5. Collaborative Action Research: Can It Improve School Effectiveness?

    ERIC Educational Resources Information Center

    Sagor, Richard D.; Curley, Janet L.

    The impact of action research on student academic and social performance is examined in this paper. Project LEARN (League of Educational Action Researchers in the Northwest), a cooperative initiative with school districts to train teams of educators in collaborative action research, was evaluated in five participating schools--two elementary, one…

  6. Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects

    PubMed Central

    Christakos, Sylvia; Dhawan, Puneet; Verstuyf, Annemieke; Verlinden, Lieve; Carmeliet, Geert

    2016-01-01

    1,25-Dihydroxvitamin D3 [1,25(OH)2D3] is the hormonally active form of vitamin D. The genomic mechanism of 1,25(OH)2D3 action involves the direct binding of the 1,25(OH)2D3 activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Numerous VDR co-regulatory proteins have been identified, and genome-wide studies have shown that the actions of 1,25(OH)2D3 involve regulation of gene activity at a range of locations many kilobases from the transcription start site. The structure of the liganded VDR/RXR complex was recently characterized using cryoelectron microscopy, X-ray scattering, and hydrogen deuterium exchange. These recent technological advances will result in a more complete understanding of VDR coactivator interactions, thus facilitating cell and gene specific clinical applications. Although the identification of mechanisms mediating VDR-regulated transcription has been one focus of recent research in the field, other topics of fundamental importance include the identification and functional significance of proteins involved in the metabolism of vitamin D. CYP2R1 has been identified as the most important 25-hydroxylase, and a critical role for CYP24A1 in humans was noted in studies showing that inactivating mutations in CYP24A1 are a probable cause of idiopathic infantile hypercalcemia. In addition, studies using knockout and transgenic mice have provided new insight on the physiological role of vitamin D in classical target tissues as well as evidence of extraskeletal effects of 1,25(OH)2D3 including inhibition of cancer progression, effects on the cardiovascular system, and immunomodulatory effects in certain autoimmune diseases. Some of the mechanistic findings in mouse models have also been observed in humans. The identification of similar pathways in humans could lead to the development of new therapies to prevent and treat disease. PMID:26681795

  7. Theoretical results on the effect of `shortcut' actions in MDPs

    NASA Astrophysics Data System (ADS)

    McCarthy, Sara M.; Precup, Doina

    2014-04-01

    Temporally extended actions have been used extensively in reinforcement learning in order to speed up the process of learning good behaviours. While such actions are intuitively appealing, very little work has provided a formal analysis of the advantage that can be obtained by using such actions. In this paper, we tackle this problem using the methodology of stochastic processes. We present case studies of Markov decision processes with actions that allow 'shortcuts' between different parts of the environment, and show how such actions affect the travel time between states. Our main finding is that such actions allow for provably quicker travel around the environment, and the benefit increases with the dimensionality of the state space. Hence, extended actions help in efficiently exploring large, high-dimensional domains.

  8. One loop superstring effective actions and N=8 supergravity

    SciTech Connect

    Moura, Filipe

    2008-06-15

    In a previous article we have shown the existence of a new independent R{sup 4} term, at one loop, in the type IIA and heterotic effective actions, after reduction to four dimensions, besides the usual square of the Bel-Robinson tensor. It had been shown that such a term could not be directly supersymmetrized, but we showed that was possible after coupling to a scalar chiral multiplet. In this article, we study the extended (N=8) supersymmetrization of this term, where no other coupling can be taken. We show that such supersymmetrization cannot be achieved at the linearized level. This is in conflict with the theory one gets after toroidal compactification of type II superstrings being N=8 supersymmetric. We interpret this result in the face of the recent claim that perturbative supergravity cannot be decoupled from string theory in d{>=}4, and N=8, d=4 supergravity is in the swampland.

  9. Influence of action-effect associations acquired by ideomotor learning on imitation.

    PubMed

    Bunlon, Frédérique; Marshall, Peter J; Quandt, Lorna C; Bouquet, Cedric A

    2015-01-01

    According to the ideomotor theory, actions are represented in terms of their perceptual effects, offering a solution for the correspondence problem of imitation (how to translate the observed action into a corresponding motor output). This effect-based coding of action is assumed to be acquired through action-effect learning. Accordingly, performing an action leads to the integration of the perceptual codes of the action effects with the motor commands that brought them about. While ideomotor theory is invoked to account for imitation, the influence of action-effect learning on imitative behavior remains unexplored. In two experiments, imitative performance was measured in a reaction time task following a phase of action-effect acquisition. During action-effect acquisition, participants freely executed a finger movement (index or little finger lifting), and then observed a similar (compatible learning) or a different (incompatible learning) movement. In Experiment 1, finger movements of left and right hands were presented as action-effects during acquisition. In Experiment 2, only right-hand finger movements were presented during action-effect acquisition and in the imitation task the observed hands were oriented orthogonally to participants' hands in order to avoid spatial congruency effects. Experiments 1 and 2 showed that imitative performance was improved after compatible learning, compared to incompatible learning. In Experiment 2, although action-effect learning involved perception of finger movements of right hand only, imitative capabilities of right- and left-hand finger movements were equally affected. These results indicate that an observed movement stimulus processed as the effect of an action can later prime execution of that action, confirming the ideomotor approach to imitation. We further discuss these findings in relation to previous studies of action-effect learning and in the framework of current ideomotor approaches to imitation.

  10. Learning Associations between Action and Perception: Effects of Incompatible Training on Body Part and Spatial Priming

    ERIC Educational Resources Information Center

    Wiggett, Alison J.; Hudson, Matt; Tipper, Steve P.; Downing, Paul E.

    2011-01-01

    Observation of another person executing an action primes the same action in the observer's motor system. Recent evidence has shown that these priming effects are flexible, where training of new associations, such as making a foot response when viewing a moving hand, can reduce standard action priming effects (Gillmeister, Catmur, Liepelt, Brass,…

  11. 43 CFR 46.115 - Consideration of past actions in the analysis of cumulative effects.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Environmental Quality § 46.115 Consideration of past actions in the analysis of cumulative effects. When... Memorandum on Consideration of Past Actions in Cumulative Effects Analysis” dated June 24, 2005, or any... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Consideration of past actions in...

  12. Action and perception in social contexts: intentional binding for social action effects

    PubMed Central

    Pfister, Roland; Obhi, Sukhvinder S.; Rieger, Martina; Wenke, Dorit

    2014-01-01

    The subjective experience of controlling events in the environment alters the perception of these events. For instance, the interval between one's own actions and their consequences is subjectively compressed—a phenomenon known as intentional binding. In two experiments, we studied intentional binding in a social setting in which actions of one agent prompted a second agent to perform another action. Participants worked in pairs and were assigned to a “leader” and a “follower” role, respectively. The leader's key presses triggered (after a variable interval) a tone and this tone served as go signal for the follower to perform a keypress as well. Leaders and followers estimated the interval between the leader's keypress and the following tone, or the interval between the tone and the follower's keypress. The leader showed reliable intentional binding for both intervals relative to the follower's estimates. These results indicate that human agents experience a pre-reflective sense of agency for genuinely social consequences of their actions. PMID:25228869

  13. Geometrical Effective Action: Gauge Field Theory Without Ghosts.

    NASA Astrophysics Data System (ADS)

    Paris, Carmen Molina

    that ghosts are in fact not needed, even in a manifestly covariant quantum theory, and that a gauge invariant quantum effective action can be introduced which, like the classical action from which one starts, is independent of ghosts and gauge-breaking terms. In this dissertation a quantum effective action for gauge field theories is constructed that is gauge invariant and independent of the choice of gauge breaking terms in the functional integral that defines it. The loop expansion of this effective action leads to new Feynman rules, involving new vertex functions but without diagrams containing ghost lines. The new rules are given in full for the Yang-Mills field, both with and without coupling to fermions, and renormalization procedures are described. No BRST arguments are needed. (Abstract shortened by UMI.) ftn^1 Throwing away the noncausal loops can be shown to be equivalent to throwing away nonvanishing contributions from arcs at infinity in the Wick rotation procedure (2). ^2The question of Lorentz invariance arises because Feynman was assuming spacetime to be asymptotically Minkowskian.

  14. The biological effects and possible modes of action of nanosilver.

    PubMed

    Völker, Carolin; Oetken, Matthias; Oehlmann, Jörg

    2013-01-01

    Novel physicochemical and biological properties have led to a versatile spectrum of applications for nanosized silver particles. Silver nanoparticles are applied primarily for their antimicrobial effects, and may variety of commercially available products have emerged. To better predict and prevent possible environmental impacts from silver nanoparticles that are derived from increasing production volumes and environmental release, more data on the biological effects are needed on appropriate model organisms. We examined the literature that addressed the adverse effects of silver nanoparticles on different levels of biological integration, including in vitro and in vivo test systems. Results of in vitro studies indicate a dose-dependent programmed cell death included by oxidative stress as main possible pathway of toxicity. Furthermore, silver nanoparticles may affect cellular enzymes by interference with free thiol groups and mimicry of endogenous ions. Similar mechanisms may apply for antibacterial effects produced by nonasilver. These effects are primary from the interference nanosilver has with bacterial cell membranes. Few in vivo studies have been performed to evaluated the toxic mode of action of nanosilver or to provide evidence for oxidative stress as an important mechanism of nanosilver toxicity. Organisms that are most acutely sensitive to nanosilver toxicity are the freshwater filter-freeding organisms. Both in vitro and in vivo studies have demonstrated tha silver ions released from nanoparticle surface contribute to the toxicity, and, indeed, some findings indicated a unique nanoparticles effect. For an adequate evaluation of the environmental impact of nanosilver, greater emphasis should be placed on combining mechanistic investigations that are performed in vitro, with results obtained in in vivo test systems. Future in vivo test system studies should emphasize long-term exposure scenarios. Moreover, the dietary uptake of silver nanoparticles and

  15. Ecological effects of contaminants and remedial actions in Bear Creek

    SciTech Connect

    Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J. ); Burris, J.A. )

    1992-01-01

    Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report.

  16. Effects of Similarity in Action-Effect Configuration on Mode Awareness

    NASA Astrophysics Data System (ADS)

    Horiguchi, Yukio; Fukuju, Ryuichi; Sawaragi, Tetsuo

    Automated systems are often structured into modes for providing enhanced capabilities to perform complex tasks, but they also increase the need for and difficulty of maintaining mode awareness, which may induce mode errors and eventually lead to automation surprises. Salient feedback on the mode status is necessary for the user to maintain mode awareness, and it should be carefully designed not to interfere in the user's primary task to be achieved in collaboration with the systems. For the purpose of developing a practical theory for effective and robust supports for maintaining mode awareness, this study focuses on action-effect relations as an intuitive human-machine communication channel. An action-effect relation is defined as an association of a user action with some observable effects on the system behavior, and it is expected to provide additional valuable information on the internal state of the system with no focal visual attention required. From this perspective, one hypothesis is made that different modes with a same or similar configuration of action-effect relations should be easily mixed up with one another. This paper tests this hypothesis through a driving simulator experiment where subject drivers were examined on their awareness of the operating mode status of ACC (Adaptive Cruise Control) during driving with the mode-rich automated system. Another experiment examines the contribution of differentiated configuration of action-effect relations to enhancing mode awareness.

  17. The cognitive representation of intending not to act: Evidence for specific non-action-effect binding.

    PubMed

    Kühn, Simone; Brass, Marcel

    2010-10-01

    The question how we represent voluntary action on a cognitive level has recently become of increasing interest to researchers studying motor control. However, so far it has been neglected how we represent the voluntary omission of an action. In our attempt to investigate the representation of voluntary non-actions we demonstrated binding effects between voluntary non-actions and subsequent action effects (Kühn, Elsner, Prinz, & Brass, 2009). That study, however, only distinguished between acting or not acting, and did not address the question of whether non-actions are coded as general omissions or whether they can be encoded specifically as the actual negation of the action in question ("not-right" or "not-left"). Our current study provides first evidence for the specificity of representations of intentional non-actions. Additionally, we compare two ways in which the specific non-actions might be represented: an ironic representation account implying that negations are prone to be omitted and a reformulated representation account assuming that the negated action is suppressed and/or the alternative action is facilitated. Our results suggest that the representation of non-actions contains a facilitation of the alternative action rather than a suppression of the action in question.

  18. Hypocholesterolemic action of dietary fiber unrelated to fecal bulking effect.

    PubMed

    Jenkins, D J; Reynolds, D; Leeds, A R; Waller, A L; Cummings, J H

    1979-12-01

    Twenty-two healthy volunteers took approximately 20 g/day of concentrated dietary fiber from either carrot, cabbage, apple, bran, or guar gum or 31 g from pectin, added for 3-week periods to controlled diets. Total serum cholesterol fell by 13% on both guar and pectin (P less than 0.01) with no significant change in high density lipoprotein cholesterol. Over the 3-week supplementation period, the other fibers were without effect with the exception of carrot, where both control and test high density lipoprotein levels fell (P less than 0.05 and less than 0.01, respectively). If, however, the 3rd week of the control was compared with the 3rd test week, the values for total cholesterol were 7% lower after apple (P less than 0.02) while after carrot the high density lipoprotein cholesterol level was 10% lower than the control (P less than 0.01). No significant change was seen in serum triglyceride or body weight either as judged by differences over the 3-week periods or by comparing test and control values at 3 weeks. Comparison of stool weights obtained in this study indicate that the fecal bulking action of dietary fiber is independent of its hypocholesterolaemic effect.

  19. Far-Infrared Rotational and Fine-Structure Transition Frequencies and Molecular Constants of 14NO and 15NO in the X2Pi (v = 0) State.

    PubMed

    Varberg; Stroh; Evenson

    1999-07-01

    We have made highly accurate measurements of the absorption spectrum of the 14NO and 15NO isotopomers of nitric oxide in the far-infrared. Pure rotational transitions up to J" = 3712 within the 2Pi1/2 and 2Pi3/2 spin components and several 2Pi3/2 <-- 2Pi1/2 fine-structure transitions were recorded within the ground vibrational state. A least-squares fit to these data combined with some lambda-doubling and rotational transitions measured by previous workers has resulted in accurate values for the rotational, fine, and hyperfine parameters of these two isotopomers. Most of the far-infrared transitions reported here have an experimental uncertainty of about 20 kHz and will be useful for astronomers and atmospheric scientists studying this important molecule. The more accurate calculated frequencies will also be useful as spectroscopic calibration standards. Copyright 1999 Academic Press.

  20. Action Control: Independent Effects of Memory and Monocular Viewing on Reaching Accuracy

    ERIC Educational Resources Information Center

    Westwood, D.A.; Robertson, C.; Heath, M.

    2005-01-01

    Evidence suggests that perceptual networks in the ventral visual pathway are necessary for action control when targets are viewed with only one eye, or when the target must be stored in memory. We tested whether memory-linked (i.e., open-loop versus memory-guided actions) and monocular-linked effects (i.e., binocular versus monocular actions) on…

  1. Attenuation of auditory N1 results from identity-specific action-effect prediction.

    PubMed

    Hughes, Gethin; Desantis, Andrea; Waszak, Florian

    2013-04-01

    The auditory N1 event-related potential has previously been observed to be attenuated for tones that are triggered by human actions. This attenuation is thought to be generated by motor prediction mechanisms and is considered to be important for agency attribution. The present study was designed to rigorously test the notion of action prediction-based sensory attenuation. Participants performed one of four voluntary actions on each trial, with each button associated with either predictable or unpredictable action effects. In addition, actions with each hand could result in action effects that were either congruent or incongruent with hand-specific prediction. We observed no significant differences in N1 amplitude between predictable and unpredictable tones. When contrasting action effects that were congruent or incongruent with hand-specific prediction, we observed significant attenuation for prediction-congruent compared to prediction-incongruent action-effects. These novel findings suggest that accurate action-effect prediction drives sensory attenuation of auditory stimuli. These findings have important implications for understanding the mechanisms of action-effect prediction and sensory attenuation, and may have clinical implications for studies investigating action awareness and agency in schizophrenia.

  2. Effects of action video game training on visual working memory.

    PubMed

    Blacker, Kara J; Curby, Kim M; Klobusicky, Elizabeth; Chein, Jason M

    2014-10-01

    The ability to hold visual information in mind over a brief delay is critical for acquiring information and navigating a complex visual world. Despite the ubiquitous nature of visual working memory (VWM) in our everyday lives, this system is fundamentally limited in capacity. Therefore, the potential to improve VWM through training is a growing area of research. An emerging body of literature suggests that extensive experience playing action video games yields a myriad of perceptual and attentional benefits. Several lines of converging work suggest that action video game play may influence VWM as well. The current study utilized a training paradigm to examine whether action video games cause improvements to the quantity and/or the quality of information stored in VWM. The results suggest that VWM capacity, as measured by a change detection task, is increased after action video game training, as compared with training on a control game, and that some improvement to VWM precision occurs with action game training as well. However, these findings do not appear to extend to a complex span measure of VWM, which is often thought to tap into higher-order executive skills. The VWM improvements seen in individuals trained on an action video game cannot be accounted for by differences in motivation or engagement, differential expectations, or baseline differences in demographics as compared with the control group used. In sum, action video game training represents a potentially unique and engaging platform by which this severely capacity-limited VWM system might be enhanced.

  3. Regulation of international energy markets: Economic effects of political actions

    NASA Astrophysics Data System (ADS)

    Shcherbakova, Anastasia V.

    Recent increases in volatility of energy prices have led many governments to reevaluate their regard of national energy reserves and reconsider future exploration, production, and consumption patterns. The flurry of activity that has been generated by such price volatility has included large-scale nationalizations of energy sectors, unilateral renegotiations of foreign energy development contracts, and expropriations of resources from foreign energy firms on one hand, and on the other hand more rapid energy sector liberalization, intensified search for and development of renewable fuels and technologies, and development of incentives for increased energy efficiency and conservation. The aim of this dissertation is to examine and quantify the extent of positive and negative effects that have resulted from some of these activities. The first chapter focuses on quantifying the effect that nationalistic sentiment has had on economic attractiveness of energy sectors during the decade prior to the recent global economic crisis, as measured by foreign direct investment (FDI) inflows. Empirical results demonstrate that both political and economic conditions play an important role in investors' decisions. A combination of investment friendliness, corruption levels, and democracy all help to explain the trends in energy-sector investment levels over time in my sample countries, although differences in the types of corruption existing in these nations do not. Investment levels, in turn, appear to influence future levels of oil production, underscoring the significance of good investment policies for future success of energy sectors. Chapter two considers the response of energy stock prices to severe regulatory actions. It employs an event study framework to examine causal effects of critical informational announcements (i.e. events of expropriation and nationalization) on daily returns and cumulative losses in firm value of energy corporations. Results show that a firm

  4. Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

    SciTech Connect

    Wang, Tao Fang; Wang, Heng; Peng, Ai Fen; Luo, Qing Feng; Liu, Zhi Li; Zhou, Rong Ping; Gao, Song; Zhou, Yang; Chen, Wen Zhao

    2013-10-18

    Highlights: •We investigate the relationship between FASN and HER2 or p-HER2 by IHC in OS tissues. •We construct FASN-specific RNAi plasmid. •Inhibiting FASN down-regulates HER2/PI3K/AKT cell signaling in U-2 OS. •Inhibiting FASN blocks U-2 OS cell invasion and migration. -- Abstract: FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

  5. Light composite Higgs from an effective action for technicolor

    SciTech Connect

    Doff, A.; Natale, A. A.; Rodrigues da Silva, P. S.

    2008-04-01

    We compute an effective action for a composite Higgs boson formed by new fermions belonging to a general technicolor non-Abelian gauge theory, using a quite general expression for the fermionic self-energy that depends on a certain parameter ({alpha}), that defines the technicolor theory from the extreme walking behavior up to the one with a standard operator product expansion behavior. We discuss the values of the trilinear and quadrilinear scalar couplings. Our calculation spans all the possible physical possibilities for mass and couplings of the composite system. In the case of extreme walking technicolor theories we verify that it is possible to have a composite Higgs boson with a mass as light as the present experimental limit, contrary to the usual expectation of a heavy mass for the composite Higgs boson. In this case we obtain an upper limit for the Higgs boson mass, (M{sub H}{<=}O(700) GeV for SU(2){sub TC}), and the experimental data on the Higgs boson mass constrain SU(N){sub TC} technicolor gauge groups to be smaller than SU(10){sub TC}.

  6. How and when auditory action effects impair motor performance.

    PubMed

    D'Ausilio, Alessandro; Brunetti, Riccardo; Delogu, Franco; Santonico, Cristina; Belardinelli, Marta Olivetti

    2010-03-01

    Music performance is characterized by complex cross-modal interactions, offering a remarkable window into training-induced long-term plasticity and multimodal integration processes. Previous research with pianists has shown that playing a musical score is affected by the concurrent presentation of musical tones. We investigated the nature of this audio-motor coupling by evaluating how congruent and incongruent cross-modal auditory cues affect motor performance at different time intervals. We found facilitation if a congruent sound preceded motor planning with a large Stimulus Onset Asynchrony (SOA -300 and -200 ms), whereas we observed interference when an incongruent sound was presented with shorter SOAs (-200, -100 and 0 ms). Interference and facilitation, instead of developing through time as opposite effects of the same mechanism, showed dissociable time-courses suggesting their derivation from distinct processes. It seems that the motor preparation induced by the auditory cue has different consequences on motor performance according to the congruency with the future motor state the system is planning and the degree of asynchrony between the motor act and the sound presentation. The temporal dissociation we found contributes to the understanding of how perception meets action in the context of audio-motor integration.

  7. Effects of Velocity on Electromyographic, Mechanomyographic, and Torque Responses to Repeated Eccentric Muscle Actions.

    PubMed

    Hill, Ethan C; Housh, Terry J; Camic, Clayton L; Smith, Cory M; Cochrane, Kristen C; Jenkins, Nathaniel D M; Cramer, Joel T; Schmidt, Richard J; Johnson, Glen O

    2016-06-01

    The purposes of this study were to examine the effects of the velocity of repeated eccentric muscle actions on the torque and neuromuscular responses during maximal isometric and eccentric muscle actions. Twelve resistance-trained men performed 30 repeated, maximal, eccentric, isokinetic muscle actions at randomly ordered velocities of 60, 120, or 180°·s on separate days. Maximal voluntary isometric contractions (MVICs) were performed before (pretest) and after (posttest) the repeated eccentric muscle actions on each day. Eccentric isokinetic peak torque (EIPT) values were the averages of the first 3 and last 3 repetitions of the 30 repeated eccentric muscle actions. During the EIPT and MVIC muscle actions, electromyographic (EMG) and mechanomyographic (MMG) amplitude (EMG AMP and MMG AMP) and mean power frequency (EMG MPF and MMG MPF) values were assessed. These results indicated that the repeated eccentric muscle actions had no effects on EIPT, or the EMG AMP, EMG MPF, or MMG MPF values assessed during the EIPT muscle actions, but decreased MMG AMP. The repeated eccentric muscle actions, however, decreased MVIC torque, and also the EMG AMP and MMG MPF values assessed during the MVIC muscle actions, but increased MMG AMP. The results indicated that the velocity of the repeated eccentric muscle actions affected the MVIC torque responses, but not EIPT or any of the neuromuscular parameters. Furthermore, there are differences in the torque and neuromuscular responses for isometric vs. eccentric muscle actions after repeated eccentric muscle actions.

  8. Simple system for measuring tritium Ad/absorption using a 2. pi. counter and thermal desorption spectrometer

    SciTech Connect

    Miyake, H.; Matsuyama, M.; Watanabe, K. ); Cowgill, D.F. )

    1992-03-01

    In this paper, the authors develop a simple system using tritium tracer and thermal desorption techniques to measure the tritium adsorption and/or absorption on/in a material having typical surface conditions: namely, not cleaned surface. The tritium counting devices used were a 2{pi} counter and conventional proportional counter. With this system, the amounts of ad/absorption could be measured without exposing the samples to air after exposing them to tritium gas. The overall efficiency (F) of the 2{pi} counter was described at F = exp({minus}2.64h), where h is the distance from the sample to the detector. Ad/absorption measurements were carried out for several materials used for fabricating conventional vacuum systems. The results were, in the order of decreasing amounts of ad/absorption, as (fiber reinforced plastics(FRP)) {gt} (nickel(Ni), molybdenum disulfide(MoS{sub 2})) {gt} (stainless steel (SS304), iron(Fe), aluminum alloy(A2219)) {gt} (boron nitride(h-BN), silicon carbide (SiC), SS304 passivated by anodic oxidation layers(ASS) and that by boron nitride segregation layers (BSS)). The relative amounts were abut 100 for Ni and 0.1 for ASS and BSS, being normalized to Fe = 1.

  9. Anticancer effect of Howiinol A and its mechanism of action.

    PubMed

    Xu, C X; He, J H

    1999-01-01

    Howiinol A (GHM-10) is a kind of phenylethylene pyrone compounds isolated from Goniothalamus howii. By using the techniques of cell growth curve determination, MTT test, soft agar colony assay and experimental therapy of transplantable tumors in mice, it is found that GHM-10 exerts potent inhibitory effect on cancer cells but its influence on normal cells is relatively slight; the sensitivity of a drug-resistant cell line, KB/VCR 2000, to GHM-10 is similar to its parent cell line KB. Remarkable therapeutic effect can be seen in mice bearing H22 hepatoma and Lewis lung cancer and in mice with ascetic sarcoma 180 when GHM-10 is orally or intraperitoneally administered. The IC50s of L1210 cells treated with GHM-10 for 1 and 24 h are 6.85 and 3.32 micrograms.ml-1 respectively. The ratio of IC50 1 h and IC50 24 h is only 2.06, indicating that the action of GHM-10 is conformed to a cell cycle non-specific cytotoxic agent. By using trypan blue exclusive test and morphological examination, it is demonstrated that the main effect of GHM-10 is to inhibit the cell proliferation. Flow cytometery technique is used to analyze the cell cycle of L1210 cells. The results show that to some extent, GHM-10 blocks the cell cycle transition from G1 phase to S phase. By using [3H] labeled precursor incorporation technique, it is shown that GHM-10 significantly suppresses the biosynthesis of DNA, RNA and protein in L1210 cells, and the DNA synthesis is mostly affected. At 1 h after the cells were treated with GHM-10, these inhibitory effects have already been irreversible, suggesting that GHM-10 may cause structural damage on DNA molecules. However, GHM-10 is unable to intercalate into DNA molecules or to destroy its structure directly. By using single cell gel electrophoresis and alkaline elution technology, it is confirmed that GHM-10 causes DNA molecule damage and single strand breakage in L1210 cells. Further studies show that GHM-10 markedly inhibits DNA dehelix induced by DNA

  10. Soft symmetry improvement of two particle irreducible effective actions

    NASA Astrophysics Data System (ADS)

    Brown, Michael J.; Whittingham, Ian B.

    2017-01-01

    Two particle irreducible effective actions (2PIEAs) are valuable nonperturbative techniques in quantum field theory; however, finite truncations of them violate the Ward identities (WIs) of theories with spontaneously broken symmetries. The symmetry improvement (SI) method of Pilaftsis and Teresi attempts to overcome this by imposing the WIs as constraints on the solution; however, the method suffers from the nonexistence of solutions in linear response theory and in certain truncations in equilibrium. Motivated by this, we introduce a new method called soft-symmetry improvement (SSI) which relaxes the constraint. Violations of WIs are allowed but punished in a least-squares implementation of the symmetry improvement idea. A new parameter ξ controls the strength of the constraint. The method interpolates between the unimproved (ξ →∞ ) and SI (ξ →0 ) cases, and the hope is that practically useful solutions can be found for finite ξ . We study the SSI 2PIEA for a scalar O (N ) model in the Hartree-Fock approximation. We find that the method is IR sensitive; the system must be formulated in finite volume V and temperature T =β-1 , and the V β →∞ limit must be taken carefully. Three distinct limits exist. Two are equivalent to the unimproved 2PIEA and SI 2PIEA respectively, and the third is a new limit where the WI is satisfied but the phase transition is strongly first order and solutions can fail to exist depending on ξ . Further, these limits are disconnected from each other; there is no smooth way to interpolate from one to another. These results suggest that any potential advantages of SSI methods, and indeed any application of (S)SI methods out of equilibrium, must occur in finite volume.

  11. The effects of an action video game on visual and affective information processing.

    PubMed

    Bailey, Kira; West, Robert

    2013-04-04

    Playing action video games can have beneficial effects on visuospatial cognition and negative effects on social information processing. However, these two effects have not been demonstrated in the same individuals in a single study. The current study used event-related brain potentials (ERPs) to examine the effects of playing an action or non-action video game on the processing of emotion in facial expression. The data revealed that 10h of playing an action or non-action video game had differential effects on the ERPs relative to a no-contact control group. Playing an action game resulted in two effects: one that reflected an increase in the amplitude of the ERPs following training over the right frontal and posterior regions that was similar for angry, happy, and neutral faces; and one that reflected a reduction in the allocation of attention to happy faces. In contrast, playing a non-action game resulted in changes in slow wave activity over the central-parietal and frontal regions that were greater for targets (i.e., angry and happy faces) than for non-targets (i.e., neutral faces). These data demonstrate that the contrasting effects of action video games on visuospatial and emotion processing occur in the same individuals following the same level of gaming experience. This observation leads to the suggestion that caution should be exercised when using action video games to modify visual processing, as this experience could also have unintended effects on emotion processing.

  12. Effects of troglitazone and pioglitazone on the action potentials and membrane currents of rabbit ventricular myocytes.

    PubMed

    Ikeda, S; Watanabe, T

    1998-09-18

    The effects of the antidiabetic thiazolidinediones troglitazone and pioglitazone on action potentials and membrane currents were studied in rabbit ventricular myocytes. Troglitazone (10 microM) reversibly reduced excitability of the myocytes and modified their action potential configuration. It significantly increased the stimulation threshold required to elicit action potentials and decreased action potential amplitude and the maximum upstroke velocity of the action potentials. The Inhibition of the maximum upstroke velocity by troglitazone was also significant at 1 microM. Voltage-clamp experiments revealed that troglitazone (10 microM) reversibly inhibited both the slow inward Ca2+ current and the steady-state K+ current. In contrast to troglitazone, pioglitazone (1-10 microM) had no significant effect on the excitability, action potential configuration, or membrane currents of myocytes. These results suggest that troglitazone, but not pioglitazone, modulates Na+, Ca2+ and K+ currents, leading to the changes in excitability and action potential configuration of ventricular myocytes.

  13. I=2{pi}{pi} scattering phase shift with two flavors of Oa improved dynamical quarks

    SciTech Connect

    Yamazaki, T.; Aoki, S.; Kanaya, K.; Fukugita, M.; Ishikawa, K-I.; Okawa, M.; Ishizuka, N.; Iwasaki, Y.; Ukawa, A.; Yoshie, T.; Kaneko, T.; Kuramashi, Y.

    2004-10-01

    We present a lattice QCD calculation of phase shift including the chiral and continuum extrapolations in two-flavor QCD. The calculation is carried out for I=2 S-wave {pi}{pi} scattering. The phase shift is evaluated for two momentum systems, the center of mass and laboratory systems, by using the finite-volume method proposed by Luescher in the center of mass system and its extension to general systems by Rummukainen and Gottlieb. The measurements are made at three different bare couplings {beta}=1.80, 1.95 and 2.10 using a renormalization group improved gauge and a tadpole improved clover fermion action, and employing a set of configurations generated for hadron spectroscopy in our previous work. The illustrative values we obtain for the phase shift in the continuum limit are {delta}(deg.)=-3.50(64), -9.5(30) and -16.9(64) for {radical}(s)(GeV)=0.4, 0.6 and 0.8, which are consistent with experiments.

  14. Intersubjective Action-Effect Binding: Eye Contact Modulates Acquisition of Bidirectional Association between Our and Others' Actions

    ERIC Educational Resources Information Center

    Sato, Atsushi; Itakura, Shoji

    2013-01-01

    In everyday social life, we predict others' actions in response to our own actions. Subsequently, on the basis of these predictions, we control our actions to attain desired social outcomes and/or adjust our actions to accommodate the anticipated actions of the others. Representation of the bidirectional association between our and others'…

  15. Effective Use of Action-Oriented Studies in Pakistan.

    ERIC Educational Resources Information Center

    Miles, M.

    1991-01-01

    This article summarizes results from action-oriented studies carried out at the Mental Heath Centre in Peshawar, Pakistan, dealing with such topics as attitudes toward disability, casual integration, and trends in polio paralysis. The article also considers problems associated with the dissemination of special education and rehabilitation research…

  16. TOPICAL REVIEW: Effective action of vacuum: the semiclassical approach

    NASA Astrophysics Data System (ADS)

    Shapiro, Ilya L.

    2008-05-01

    We present a brief, and to a great extent, pedagogical, review on renormalization in curved spacetime and some recent results on the derivation and better understanding of quantum corrections to the action of gravity. The paper is mainly devoted to the semiclassical approach, but we also discuss its importance for quantum gravity and string theory.

  17. State Actions to Advance Teacher Evaluation. Educator Effectiveness Series

    ERIC Educational Resources Information Center

    Gandha, Tysza; Baxter, Andy

    2016-01-01

    This report offers state leaders key areas for action to continue progress in implementing evaluation systems, even as federal policies on teacher evaluation relax state requirements. The Southern Regional Education Board (SREB) offers its current best thinking for how state agencies can make the smartest use of funds, time and partners to refine…

  18. Object Rotation Effects on the Timing of a Hitting Action

    ERIC Educational Resources Information Center

    Scott, Mark A.; van der Kamp, John; Savelsbergh, Geert J. P.; Oudejans, Raoul R. D.; Davids, Keith

    2004-01-01

    In this article, the authors investigated how perturbing optical information affects the guidance of an unfolding hitting action. Using monocular and binocular vision, six participants were required to hit a rectangular foam object, released from two different heights, under four different approach conditions, two with object rotation (to perturb…

  19. Calculated hydroxyl A2 sigma --> X2 pi (0, 0) band emission rate factors applicable to atmospheric spectroscopy.

    PubMed

    Cageao, R P; Ha, Y L; Jiang, Y; Morgan, M F; Yung, Y L; Sander, S P

    1997-05-01

    A calculation of the A2 sigma --> X2 pi (0, 0) band emission rate factors and line center absorption cross sections of OH applicable to its measurement using solar resonant fluorescence in the terrestrial atmosphere is presented in this paper. The most accurate available line parameters have been used. Special consideration has been given to the solar input flux because of its highly structured Fraunhofer spectrum. The calculation for the OH atmospheric emission rate factor in the solar resonant fluorescent case is described in detail with examples and intermediate results. Results of this calculation of OH emission rate factors for individual rotational lines are on average 30% lower than the values obtained in an earlier work.

  20. Constraining gravitational interactions in the M theory effective action

    NASA Astrophysics Data System (ADS)

    Basu, Anirban

    2014-08-01

    We consider purely gravitational interactions of the type {{D}^{6n}}{{{ R}}^{4}} in the effective action of M theory in 11 dimensional flat spacetime. The duality between M theory on S 1 and type IIA string theory relates them to the type IIA interactions of the form {{e}^{2n{{\\phi }_{A}}}}{{D}^{6n}}{{{ R}}^{4}} where {{\\phi }_{A}} is the type IIA dilaton. The coefficients of the M theory interactions are determined by the strongly coupled type IIA theory. Given the nature of the dilaton dependence, it is plausible that for low values of n, the coefficient has a similar structure as the genus (n+1) string amplitude of the type IIA {{D}^{6n}}{{{ R}}^{4}} interaction, namely the transcendental nature. Assuming this, and focussing on the even-even spin structure part of the type IIA string amplitude, this coefficient is given by the type IIB genus (n+1) amplitude, which we constrain using supersymmetry, S-duality and maximal supergravity. The source terms of the Poisson equations satisfied by the S-duality invariant IIB couplings play a central role in the analysis. This procedure yields partial contributions to several multi-loop type IIB string amplitudes, from which we extract the transcendental nature of the corresponding M theory couplings. For n\\leqslant 2, all possible source terms involve only BPS couplings. While the {{{ R}}^{4}} and {{D}^{6}}{{{ R}}^{4}} M theory couplings agree with known results, the coefficient of the {{D}^{12}}{{{ R}}^{4}} interaction takes the form \\zeta {{(2)}^{3}}({{\\Omega }_{1}}+{{\\Omega }_{2}}\\zeta (3)). We also analyze the {{D}^{18}}{{{ R}}^{4}} and {{D}^{24}}{{{ R}}^{4}} interactions, and show that their coefficients have at least the terms \\zeta {{(2)}^{4}}({{\\tilde{\\Omega }}_{1}}+{{\\tilde{\\Omega }}_{2}}\\zeta (3)+{{\\tilde{\\Omega }}_{3}}\\zeta (5)) and \\zeta {{(2)}^{5}}({{\\underline{\\Omega }}_{1}}+{{\\underline{\\Omega }}_{2}}\\zeta (3)+{{\\underline{\\Omega }}_{3}}\\zeta (5) +\\;{{\\underline{\\Omega }}_{4

  1. Loop expansion of the average effective action in the functional renormalization group approach

    NASA Astrophysics Data System (ADS)

    Lavrov, Peter M.; Merzlikin, Boris S.

    2015-10-01

    We formulate a perturbation expansion for the effective action in a new approach to the functional renormalization group method based on the concept of composite fields for regulator functions being their most essential ingredients. We demonstrate explicitly the principal difference between the properties of effective actions in these two approaches existing already on the one-loop level in a simple gauge model.

  2. What is the general action of ghrelin for vertebrates? - comparisons of ghrelin's effects across vertebrates.

    PubMed

    Kaiya, Hiroyuki; Kangawa, Kenji; Miyazato, Mikiya

    2013-01-15

    Ten years and more passed since ghrelin was discovered. Various physiological actions of ghrelin have been documented in both mammalian and nonmammalian vertebrates. Do these actions have any commonality? In this review, we focused on several effects of ghrelin, and compared the effect across vertebrates. We would like to discuss possible general function of ghrelin in vertebrates.

  3. Target- and Effect-Directed Actions towards Temporal Goals: Similar Mechanisms?

    ERIC Educational Resources Information Center

    Walter, Andrea M.; Rieger, Martina

    2012-01-01

    The goal of an action can consist of generating a change in the environment (to produce an effect) or changing one's own situation in the environment (to move to a physical target). To investigate whether the mechanisms of effect-directed and target-directed action control are similar, participants performed continuous reversal movements. They…

  4. On the importance of being first: serial order effects in the interaction between action plans and ongoing actions.

    PubMed

    Fournier, Lisa R; Gallimore, Jonathan M; Feiszli, Kevin R; Logan, Gordon D

    2014-02-01

    When we plan sequences of actions, we must hold some elements of the sequence in working memory (WM) while we execute others. Research shows that execution of an action can be delayed if it partly overlaps (vs. does not overlap) with another action plan maintained in WM (partial repetition cost). However, it is not known whether all features of the action maintained in WM interfere equally with current actions. Most serial models of memory and action assume that interference will be equal, because all action features in the sequence should be activated to an equal degree in parallel; others assume that action features earlier in the sequence will interfere more than those later in the sequence, because earlier features will be more active. Using a partial repetition paradigm, this study examined whether serial position of action features in action sequences maintained in WM have an influence on current actions. Two stimulus events occurred in a sequence, and participants planned and maintained an action sequence to the first event (action A) in WM while executing a speeded response to the second event (action B). Results showed delayed execution of action B when it matched the first feature in the action A sequence (partial repetition cost), but not when it matched the last feature. These findings suggest that serial order is represented in the action plan prior to response execution, consistent with models that assume that serial order is represented by a primacy gradient of parallel feature activation prior to action execution.

  5. Forecasting Effects of MISO Actions: An ABM Methodology

    DTIC Science & Technology

    2013-12-01

    MISO ACTIONS: AN ABM METHODOLOGY Chris Weimer J.O. Miller Mark Friend Janet Miller Department of Operational Sciences Graduate School of...AFB,OH 45433 USA Wright Patterson AFB, OH 45433, USA ABSTRACT Agent-based models ( ABM ) have been used successfully in the field of generative...develop an ABM to investigate factors that affect the growth of rebel uprisings in a notional population. Our ABM expands the civil violence model

  6. Focused ultrasound effects on nerve action potential in vitro

    PubMed Central

    Colucci, Vincent; Strichartz, Gary; Jolesz, Ferenc; Vykhodtseva, Natalia; Hynynen, Kullervo

    2009-01-01

    Minimally invasive applications of thermal and mechanical energy to selective areas of the human anatomy have led to significant advances in treatment of and recovery from typical surgical interventions. Image-guided focused ultrasound allows energy to be deposited deep into the tissue, completely noninvasively. There has long been interest in using this focal energy delivery to block nerve conduction for pain control and local anesthesia. In this study, we have performed an in vitro study to further extend our knowledge of this potential clinical application. The sciatic nerves from the bullfrog (Rana catesbeiana) were subjected to focused ultrasound (at frequencies of 0.661MHz and 1.986MHz) and to heated Ringer’s solution. The nerve action potential was shown to decrease in the experiments and correlated with temperature elevation measured in the nerve. The action potential recovered either completely, partially, or not at all, depending on the parameters of the ultrasound exposure. The reduction of the baseline nerve temperature by circulating cooling fluid through the sonication chamber did not prevent the collapse of the nerve action potential; but higher power was required to induce the same endpoint as without cooling. These results indicate that a thermal mechanism of focused ultrasound can be used to block nerve conduction, either temporarily or permanently. PMID:19647923

  7. Photoacoustic measurement of differential broadening of the Lambda doublets in NO(X 2Pi 1/2,v = 2-0) by Ar

    NASA Technical Reports Server (NTRS)

    Pine, A. S.

    1989-01-01

    A differential broadening of the Lambda doublets in the v = 2-0 overtone band of the 2pi1/2 ground electronic state of NO in an Ar buffer gas has been observed by photoacoustic spectroscopy using a tunable color-center laser. The broadening coefficients for the f symmetry components are larger than for the e symmetry components by up to about 6 percent for J of about 16.5. This differential depends on J and vanishes at low J, implicating the anisotropy of the unpaired electron Pi orbital in the plane of rotation. The 2Pi3/2 transitions are slightly broader than the 2Pi1/2 as a result of spin-flipping collisional relaxation. The observed line shapes also exhibit collisional or Dicke narrowing due to velocity-changing collisions.

  8. Action semantics modulate action prediction.

    PubMed

    Springer, Anne; Prinz, Wolfgang

    2010-11-01

    Previous studies have demonstrated that action prediction involves an internal action simulation that runs time-locked to the real action. The present study replicates and extends these findings by indicating a real-time simulation process (Graf et al., 2007), which can be differentiated from a similarity-based evaluation of internal action representations. Moreover, results showed that action semantics modulate action prediction accuracy. The semantic effect was specified by the processing of action verbs and concrete nouns (Experiment 1) and, more specifically, by the dynamics described by action verbs (Experiment 2) and the speed described by the verbs (e.g., "to catch" vs. "to grasp" vs. "to stretch"; Experiment 3). These results propose a linkage between action simulation and action semantics as two yet unrelated domains, a view that coincides with a recent notion of a close link between motor processes and the understanding of action language.

  9. Response-effect compatibility with complex actions: the case of wheel rotations.

    PubMed

    Janczyk, Markus; Yamaguchi, Motonori; Proctor, Robert W; Pfister, Roland

    2015-04-01

    The response-effect compatibility (REC) paradigm provides an elegant tool for studying the impact of anticipated action effects on action control. Converging evidence for such anticipative processes has mainly emerged from tasks that require simple, discrete actions, whereas tasks that require more complex, continuous actions such as wheel-rotation responses have yielded discrepant results. We investigate the role of two moderating variables that have only played a minor role in effect-based theories of human action control and may account for this discrepancy: (1) the degree of dimensional overlap (rather than its mere presence) and (2) directing attention towards the action effects. The results of three experiments suggest that both factors are crucial in determining the size of REC effects for continuous wheel-rotation responses: Reliable REC effects were obtained, and they were larger with high than with low dimensional overlap and when attending to the effects than when not. Thus, the study points toward important preconditions that determine whether and how effect anticipations affect complex motor actions.

  10. Differential effects of K(+) channel blockers on frequency-dependent action potential broadening in supraoptic neurons.

    PubMed

    Hlubek, M D; Cobbett, P

    2000-09-15

    Recordings were made from magnocellular neuroendocrine cells dissociated from the supraoptic nucleus of the adult guinea pig to determine the role of voltage gated K(+) channels in controlling the duration of action potentials and in mediating frequency-dependent action potential broadening exhibited by these neurons. The K(+) channel blockers charybdotoxin (ChTx), tetraethylammonium (TEA), and 4-aminopyridine (4-AP) increased the duration of individual action potentials indicating that multiple types of K(+) channel are important in controlling action potential duration. The effect of these K(+) channel blockers was almost completely reversed by simultaneous blockade of voltage gated Ca(2+) channels with Cd(2+). Frequency-dependent action potential broadening was exhibited by these neurons during trains of action potentials elicited by membrane depolarizing current pulses presented at 10 Hz but not at 1 Hz. 4-AP but not ChTx or TEA inhibited frequency-dependent action potential broadening indicating that frequency-dependent action potential broadening is dependent on increasing steady-state inactivation of A-type K(+) channels (which are blocked by 4-AP). A model of differential contributions of voltage gated K(+) channels and voltage gated Ca(2+) channels to frequency-dependent action potential broadening, in which an increase of Ca(2+) current during each successive action potential is permitted as a result of the increasing steady-state inactivation of A-type K(+) channels, is presented.

  11. Complex multireference configuration interaction calculations employing a coupled diabatic representation for the 2Pi(g) resonance states of N2(-).

    PubMed

    Honigmann, Michael; Buenker, Robert J; Liebermann, Heinz-Peter

    2009-07-21

    Complex multireference configuration interaction calculations have been carried out for the lowest resonance states of (2)Pi(g) symmetry of the N(2)(-) molecule. It is shown that there is a forbidden crossing between the two lowest roots of this symmetry and that a satisfactory calculation of vibrational levels and cross sections therefore requires inclusion of both states and the coupling between them. A diabatic representation for the two (2)Pi(g) states was determined and vibronic calculations of the cross sections for vibrational excitation were carried out with a two-dimensional complex variational program.

  12. The Side-Effect Effect in Children Is Robust and Not Specific to the Moral Status of Action Effects

    PubMed Central

    Rakoczy, Hannes; Behne, Tanya; Clüver, Annette; Dallmann, Stephanie; Weidner, Sarah; Waldmann, Michael R.

    2015-01-01

    Adults’ intentionality judgments regarding an action are influenced by their moral evaluation of this action. This is clearly indicated in the so-called side-effect effect: when told about an action (e.g. implementing a business plan) with an intended primary effect (e.g. raise profits) and a foreseen side effect (e.g. harming/helping the environment), subjects tend to interpret the bringing about of the side effect more often as intentional when it is negative (harming the environment) than when it is positive (helping the environment). From a cognitive point of view, it is unclear whether the side-effect effect is driven by the moral status of the side effects specifically, or rather more generally by its normative status. And from a developmental point of view, little is known about the ontogenetic origins of the effect. The present study therefore explored the cognitive foundations and the ontogenetic origins of the side-effect effect by testing 4-to 5-year-old children with scenarios in which a side effect was in accordance with/violated a norm. Crucially, the status of the norm was varied to be conventional or moral. Children rated the bringing about of side-effects as more intentional when it broke a norm than when it accorded with a norm irrespective of the type of norm. The side-effect effect is thus an early-developing, more general and pervasive phenomenon, not restricted to morally relevant side effects. PMID:26218422

  13. Action scales for quantum decoherence and their relation to structures in phase space

    SciTech Connect

    Alonso, Daniel; Brouard, S.; Palao, Jose P.; Mayato, R. Sala

    2004-05-01

    A characteristic action {delta}S is defined whose magnitude determines some properties of the expectation value of a general quantum displacement operator. These properties are related to the capability of a given environmental ''monitoring'' system to induce decoherence in quantum systems coupled to it. We show that the scale for effective decoherence is given by {delta}S{approx_equal}({Dirac_h}/2{pi}). We relate this characteristic action with a complementary quantity, {delta}Z, and analyze their connection with the main features of the pattern of structures developed by the environmental state in different phase space representations. The relevance of the {delta}S-action scale is illustrated using both a model quantum system solved numerically and a set of model quantum systems for which analytical expressions for the time-averaged expectation value of the displacement operator are obtained explicitly.

  14. Hepatitis C Virus Induces MDSCs-Like Monocytes through TLR2/PI3K/AKT/STAT3 Signaling

    PubMed Central

    Zhai, Naicui; Li, Haijun; Song, Hongxiao; Yang, Yang; Cui, An; Li, Tianyang; Niu, Junqi; Crispe, Ian Nicholas; Su, Lishan; Tu, Zhengkun

    2017-01-01

    Background and Aims Recent studies reveal the accumulation of myeloid derived suppressor cells (MDSCs) in human peripheral blood mononuclear cells (PBMCs) following HCV infection, which may facilitate and maintain HCV persistent infection. The mechanisms by which HCV induces MDSCs are poorly understood. In the present study, we investigated the mechanisms by which HCV induces MDSCs that lead to suppression of T cell proliferation and expansion of CD4+Foxp3+ regulatory T cells. Methods Purified monocytes from healthy donors were cultured with HCV core protein (HCVc) or cell culture-derived HCV virions (HCVcc), and characterized the phenotype and function of these monocytes by flow cytometry, quantitative PCR, ELISA and western blot assays. In addition, peripheral blood from healthy donors and chronic HCV infected patients was collected, and MDSCs and CD4+CD25+CD127- regulatory T cells were analyzed by flow cytometry. Results Both HCVc and HCVcc induced expression of IDO1, PD-L1 and IL-10, and significantly down-regulated HLA-DR expression in human monocytes. HCVc-treated monocytes triggered CD4+Foxp3+ Tregs expansion, and inhibited autologous CD4+ T cell activation in an IDO1-dependent fashion. Our results showed that HCV virions or HCV core proteins induced MDSC-like suppressive monocytes via the TLR2/PI3K/AKT/STAT3 signaling pathway. Monocytes derived from patients with chronic HCV infection displayed MDSCs characteristics. Moreover, the percentages of CD14+ MDSCs and CD4+CD25+CD127- Tregs in chronic HCV infected patients were significantly higher than healthy individuals, and the frequency of MDSCs correlated with CD4+CD25+CD127- Tregs. Conclusions HCV induced MDSC-like suppressive monocytes through TLR2/PI3K/AKT/STAT3 signaling pathway to induce CD4+Foxp3+ regulatory T cells and inhibit autologous CD4+ T cell activation. It will be of interest to test whether antagonizing suppressive functions of MDSCs could enhance immune responses and virus control in chronic

  15. Effects of binge drinking on action cascading processes: an EEG study.

    PubMed

    Stock, Ann-Kathrin; Blaszkewicz, Meinolf; Beste, Christian

    2014-02-01

    High-dosage alcohol intoxication (i.e., binge drinking in humans) is an increasingly prevalent problem. Despite the well-known long-term consequences, the acute effects of high-dosage alcohol intoxication on cognitive control processes have not been investigated with respect to neurophysiological changes in humans. We provide insights into the effects of high-dosage ethanol intoxication on action control functions in humans on the basis of neurophysiological (EEG) data. Action control processes were examined in a stop-change task. Based on a detailed analysis of behavioral and electrophysiological data, we demonstrate a specific modulation of action cascading processes. Opposed to commonly held views, high-dosage ethanol intoxication (0.9-1.13 ‰) exerts highly specific effects on cognitive subprocesses mediating action control. If action control processes are performed in succession, intoxicated and non-intoxicated participants perform equally well. However, action control processes become compromised during high-dosage ethanol intoxication, when different response options require processing resources in parallel. Under high-dose ethanol intoxication, subjects are not able to prioritize different response options. We could demonstrate that the effects were of high effect sizes (η (2) = 0.702) and rely more on response selection deficits than on deficits in attentional processing. The changes in response selection processes are mediated via the anterior cingulate cortex. The specificity of the observed effects may be due to a differential involvement of dopaminergic and GABAergic processes in action control and attentional selection processes.

  16. High-energy effective action from scattering of QCD shock waves

    SciTech Connect

    Ian Balitsky

    2005-07-01

    At high energies, the relevant degrees of freedom are Wilson lines - infinite gauge links ordered along straight lines collinear to the velocities of colliding particles. The effective action for these Wilson lines is determined by the scattering of QCD shock waves. I develop the symmetric expansion of the effective action in powers of strength of one of the shock waves and calculate the leading term of the series. The corresponding first-order effective action, symmetric with respect to projectile and target, includes both up and down fan diagrams and pomeron loops.

  17. High-energy effective action from scattering of QCD shock waves

    SciTech Connect

    Ian Balitsky

    2005-10-25

    At high energies, the relevant degrees of freedom are Wilson lines--infinite gauge links ordered along straight lines collinear to the velocities of colliding particles. The effective action for these Wilson lines is determined by the scattering of QCD shock waves. I develop the symmetric expansion of the effective action in powers of strength of one of the shock waves and calculate the leading term of the series. The corresponding first-order effective action, symmetric with respect to the projectile and target, includes both up and down fan diagrams and pomeron loops.

  18. In-Out Formalism for One-Loop Effective Actions in QED and Gravity

    NASA Astrophysics Data System (ADS)

    Kim, S. P.

    2017-03-01

    The in-out formalism is a systematic and powerful method for finding the effective actions in an electromagnetic field and a curved spacetime provided that the field equation has explicitly known solutions. The effective action becomes complex when pairs of charged particles are produced due to an electric field and curved spacetime. This may lead to a conjecture of one-to-one correspondence between the vacuum polarization (real part) and the vacuum persistence (imaginary part). We illustrate the one-loop effective action in a constant electric field in a Minkowski spacetime and in a uniform electric field in a two-dimensional (anti-) de Sitter space.

  19. High-energy effective action from scattering of QCD shock waves

    SciTech Connect

    Ian Balitsky

    2005-05-15

    At high energies, the relevant degrees of freedom are Wilson lines - infinite gauge links ordered along straight lines collinear to the velocities of colliding particles. The effective action for these Wilson lines is determined by the scattering of QCD shock waves. I develop the symmetric expansion of the effective action in powers of strength of one of the shock waves and calculate the leading term of the series. The corresponding first-order effective action, symmetric with respect to projectile and target, includes both up and down fan diagrams and pomeron loops.

  20. Effect of Constrained Arm Posture on the Processing of Action Verbs

    PubMed Central

    Yasuda, Masaaki; Stins, John F.; Higuchi, Takahiro

    2017-01-01

    Evidence is increasing that brain areas that are responsible for action planning and execution are activated during the information processing of action-related verbs (e.g., pick or kick). To obtain further evidence, we conducted three experiments to see if constraining arm posture, which could disturb the motor planning and imagery for that arm, would lead to delayed judgment of verbs referring to arm actions. In all experiments, native Japanese speakers judged as quickly as possible whether the presented object and the verb would be compatible (e.g., ball–throw) or not (e.g., ball–pour). Constrained arm posture was introduced to the task by asking participants to keep both hands behind their back. Two types of verbs were used: manual action verbs (i.e., verbs referring to actions performed on an object by a human hand) and non-manual action verbs. In contrast to our hypothesis that constrained arm posture would affect only the information processing of manual action verbs, the results showed delayed processing of both manual action and non-manual action verbs when the arm posture was constrained. The effect of constrained arm posture was observed even when participants responded with their voice, suggesting that the delayed judgment was not simply due to the difficulty of responding with the hand (i.e., basic motor interference). We discussed why, contrary to our hypothesis, constrained arm posture resulted in delayed CRTs regardless of the “manipulability” as symbolized by the verbs. PMID:28239336

  1. Adverse Effects of Psychotropic Medications: A Call to Action.

    PubMed

    Mago, Rajnish

    2016-09-01

    Adverse effects are common, bothersome, and a leading cause of discontinuation of treatment. The methodology for evaluating adverse effects of medications has been greatly neglected, however, especially in comparison to the methodology for assessment of efficacy of medications. Existing methods for assessment and reporting of adverse effects have important limitations leading to lack of much-needed data related to adverse effects. Lastly, there is little systematic research into management of most adverse effects. A series of recommendations are made in this article about how to improve identification, assessment, reporting, and management of adverse effects.

  2. Leadership: Improving Its Effectiveness. Research Action Brief Number 1.

    ERIC Educational Resources Information Center

    ERIC Clearinghouse on Educational Management, Eugene, OR.

    This brief summarizes the major findings of significant research studies dealing with different leadership behaviors and strategies for increasing leadership effectiveness. Fred Fiedler's Contingency Theory of Leadership Effectiveness emphasizes that a leader's effectiveness is determined by how well his leadership style fits the specific…

  3. Study of the Decay {tau}{sup -} {yields} 2 {pi}{sup -}{pi}{sup +}3{pi}{sup 0}{nu}{sub {tau}}

    SciTech Connect

    Jessop, Colin P.

    2003-05-05

    The decay {tau}{sup -} {yields} 2{pi}{sup -}{pi}{sup +}3{pi}{sup 0}{nu}{sub {tau}} has been studied with the CLEO II detector at the Cornell Electron Storage Ring (CESR). The branching fraction is measured to be (2.85 {+-} 0.56 {+-} 0.51) x 10{sup -4}. The result is in good agreement with the isospin expectation but somewhat below the Conserved-Vector-Current (CVC) prediction. We have searched for resonance substructure in the decay. Within the statistical precision, the decay is saturated by the channels {tau}{sup -} {yields} {pi}{sup -}2{pi}{sup 0}{omega}{nu}{sub {tau}}, 2{pi}{sup -}{pi}{sup +}{eta}{nu}{sub {tau}}, and {pi}{sup -}2{pi}{sup 0}{eta}{nu}{sub {tau}}.. This is the first observation of this {omega} decay mode and the branching fraction is measured to be (1.89{sub -0.67}{sup +0.74} {+-} 0.40) x 10{sup -4}.

  4. Hawking radiation from the Garfinkle-Horowitz-Strominger black hole, effective action, and covariant boundary condition

    SciTech Connect

    Gangopadhyay, Sunandan

    2008-03-15

    We exploit the expression for the anomalous (chiral) effective action to obtain the Hawking radiation from a Garfinkle-Horowitz-Strominger (stringy) black hole falling in the class of the most general spherically symmetric black holes ({radical}(-g){ne}1), using only covariant boundary conditions at the event horizon. The connection between the anomalous and the normal energy-momentum tensors is also established from the effective action approach.

  5. The effect of action recognition and robot awareness in cooperative robot teams

    SciTech Connect

    Parker, L.E.

    1995-03-01

    Previous research in cooperative robotics has investigated several possible ways of coordinating the actions of cooperative teams -- from implicit cooperation through sensory feedback to explicit cooperation using the exchange of communicated messages. These various approaches differ in the extent to which robot team members arc aware of, or recognize, the actions of their teammates, and the extent to which they use this information to effect their own actions. The research described in this paper investigates this issue of robot awareness of team member actions and its effect on cooperative team performance by examining the results of a series of experiments on teams of physical mobile robots performing a laboratory version of hazardous waste cleanup. In these experiments. we vary the team size (and thus the level of redundancy in team member capabilities) and the level of awareness robots have of their teammates` current actions and evaluate the team`s performance using two metrics: time and energy. The results indicate that the impact of action awareness on cooperative team performance is a function not only of team size and the metric of evaluation. but also on the degree to which the effects of actions can be sensed through the world, the relative amount of work that is available per robot, and the cost of replicated actions. From these empirical studies, we propose a number of principles regarding the use of action recognition and robot awareness of team member actions in cooperative teams -- principles which will help guide engineers in the design and composition of the proper cooperative team for a given robotic mission.

  6. The effect of viewing graspable objects and actions in Parkinson's disease.

    PubMed

    Poliakoff, Ellen; Galpin, Adam; Dick, Jeremy; Moore, Peter; Tipper, Steven P

    2007-03-26

    Viewing action-relevant stimuli such as a graspable object or another person moving can affect the observer's own motor system. Evidence exists that external stimuli may facilitate or hinder movement in Parkinson's disease, so we investigated whether action-relevant stimuli would exert a stronger influence. We measured the effect of action-relevant stimuli (graspable door handles and finger movements) on reaction times compared with baseline stimuli (bars and object movements). Parkinson's patients were influenced by the location of the baseline stimuli, but unlike healthy controls, action-relevant stimuli did not exert a stronger influence. This suggests that external cues exert their influence in Parkinson's disease through lower-level visual processes and the influence of action-relevant stimuli on the motor system is disrupted.

  7. Inactivation of the Mitochondrial Carrier SLC25A25 (ATP-Mg2+/Pi Transporter) Reduces Physical Endurance and Metabolic Efficiency in Mice*

    PubMed Central

    Anunciado-Koza, Rea P.; Zhang, Jingying; Ukropec, Jozef; Bajpeyi, Sudip; Koza, Robert A.; Rogers, Richard C.; Cefalu, William T.; Mynatt, Randall L.; Kozak, Leslie P.

    2011-01-01

    An ATP-Mg2+/Pi inner mitochondrial membrane solute transporter (SLC25A25), which is induced during adaptation to cold stress in the skeletal muscle of mice with defective UCP1/brown adipose tissue thermogenesis, has been evaluated for its role in metabolic efficiency. SLC25A25 is thought to control ATP homeostasis by functioning as a Ca2+-regulated shuttle of ATP-Mg2+ and Pi across the inner mitochondrial membrane. Mice with an inactivated Slc25a25 gene have reduced metabolic efficiency as evidenced by enhanced resistance to diet-induced obesity and impaired exercise performance on a treadmill. Mouse embryo fibroblasts from Slc25a25−/− mice have reduced Ca2+ flux across the endoplasmic reticulum, basal mitochondrial respiration, and ATP content. Although Slc25a25−/− mice are metabolically inefficient, the source of the inefficiency is not from a primary function in thermogenesis, because Slc25a25−/− mice maintain body temperature upon acute exposure to the cold (4 °C). Rather, the role of SLC25A25 in metabolic efficiency is most likely linked to muscle function as evidenced from the physical endurance test of mutant mice on a treadmill. Consequently, in the absence of SLC25A25 the efficiency of ATP production required for skeletal muscle function is diminished with secondary effects on adiposity. However, in the absence of UCP1-based thermogenesis, induction of Slc25a25 in mice with an intact gene may contribute to an alternative thermogenic pathway for the maintenance of body temperature during cold stress. PMID:21296886

  8. [The effect of food intake on drug action].

    PubMed

    Pletscher, W; Peretti, E

    1990-01-01

    Interactions between medicaments and food are only incompletely documented--despite their frequent occurrence. Food can influence the effect of medicaments in a variety of ways: the effect of the medicament can be delayed or weakened; in some cases the effect may also be increased. The interactions between the kinetics of medicaments and food are described in the present survey. The absorption conditions in the stomach and small intestine are influenced physiologically and chemically by food. In very rare cases the elimination of active ingredients too can be modified by the quality and quantity of the food. Detailed knowledge about the physical-chemical properties of the medicaments used help to optimize the pharmacotherapy in the individual case. For the patient, the easiest suggestion to follow would be to take the medicaments with plenty of water and always at the same time.

  9. Explanation of non-additive effects in mixtures of similar mode of action chemicals.

    PubMed

    Kamo, Masashi; Yokomizo, Hiroyuki

    2015-09-01

    Many models have been developed to predict the combined effect of drugs and chemicals. Most models are classified into two additive models: independent action (IA) and concentration addition (CA). It is generally considered if the modes of action of chemicals are similar then the combined effect obeys CA; however, many empirical studies report nonlinear effects deviating from the predictions by CA. Such deviations are termed synergism and antagonism. Synergism, which leads to a stronger toxicity, requires more careful management, and hence it is important to understand how and which combinations of chemicals lead to synergism. In this paper, three types of chemical reactions are mathematically modeled and the cause of the nonlinear effects among chemicals with similar modes of action was investigated. Our results show that combined effects obey CA only when the modes of action are exactly the same. Contrary to existing knowledge, combined effects are generally nonlinear even if the modes of action of the chemicals are similar. Our results further show that the nonlinear effects vanish out when the chemical concentrations are low, suggesting that the current management procedure of assuming CA is rarely inappropriate because environmental concentrations of chemicals are generally low.

  10. Acute Stressor Effects on Goal-Directed Action in Rats

    ERIC Educational Resources Information Center

    Braun, Stephanie; Hauber, Wolfgang

    2013-01-01

    Here we examined effects of acute stressors that involve either systemic coadministration of corticosterone/yohimbine (3 mg/kg each) to increase glucocorticoid/noradrenaline activity (denoted as "pharmacological" stressor) or one or several distinct restraint stressors (denoted as "single" vs. "multiple" stressor) on…

  11. [The PLACEBO effect: Definition, theories of action, ethical considerations].

    PubMed

    Andreou, Ch; Bozikas, V P

    2008-04-01

    The placebo effect (from latin placere=to please), i.e. the nonspecific psychological therapeutic effects of a substance or procedure, remains one of the biggest challenges encountered by modern medicine, as a therapeutic means with unquestionable and yet unappreciated, global and yet uncontrollable, efficacy. The history of medicine largely intersects the history of placebo effect, as the first scientifically proven non-placebo drug only appeared in the 17th century. Today, placebos have themselves become an object of investigations aiming to clarify the mechanisms of mind-body interactions. Moreover, placebos occupy an important place as methodological tools in modern medical research; randomized double-blind, placebo-controlled studies have been established as the golden standard in the evaluation of new therapies. However, the use of placebos raises a number of important ethical issues, as it comes in contrast to the two most basic principles of medicine, beneficence and autonomy. Therefore, the use of placebos in clinical research should always include measures that ensure minimization of any risk associated with delay of active treatment, as well as preser vation of the patients' interests. In clinical practice, physicians should be aware of psychological dimensions of treatment, of the meaning that the patient ascribes to it, as well as of the influence of the doctor-patient relationship, so that they can use these beneficial nonspecific (i.e. placebo) effects of treatment in the best interest of their patients.

  12. Observation Can Be as Effective as Action in Problem Solving

    ERIC Educational Resources Information Center

    Osman, Magda

    2008-01-01

    This study discusses findings that replicate and extend the original work of Burns and Vollmeyer (2002), which showed that performance in problem-solving tasks was more accurate when people were engaged in a non-specific goal than in a specific goal. The main innovation here was to examine the goal specificity effect under both observation-based…

  13. Action-effect binding is decreased in motor conversion disorder: implications for sense of agency.

    PubMed

    Kranick, Sarah M; Moore, James W; Yusuf, Nadia; Martinez, Valeria T; LaFaver, Kathrin; Edwards, Mark J; Mehta, Arpan R; Collins, Phoebe; Harrison, Neil A; Haggard, Patrick; Hallett, Mark; Voon, Valerie

    2013-07-01

    The abnormal movements seen in motor conversion disorder are affected by distraction and entrainment, similar to voluntary movement. Unlike voluntary movement, however, patients lack a sense of control for the abnormal movements, a failure of "self-agency." The action-effect binding paradigm has been used to quantify the sense of self-agency, because subjective contraction of time between an action and its effect only occurs if the patient feels that they are the agent responsible for the action. We used this paradigm, coupled with emotional stimuli, to investigate the sense of agency with voluntary movements in patients with motor conversion disorder. Twenty patients with motor conversion disorder and 20 age-matched and sex-matched healthy volunteers used a rotating clock to judge the time of their own voluntary key presses (action) and a subsequent auditory tone (effect) after they completed conditioning blocks in which high, medium, and low tones were coupled to images of happy, fearful, and neutral faces. The results replicated those produced previously: it was reported that an effect after a voluntary action occurred earlier, and the preceding action occurred later, compared with trials that used only key presses or tones. Patients had reduced overall binding scores relative to healthy volunteers, suggesting a reduced sense of agency. There was no effect of the emotional stimuli (faces) or other interaction effects. Healthy volunteers with subclinical depressive symptoms had higher overall binding scores. We demonstrate that patients with motor conversion disorder have decreased action-effect binding for normal voluntary movements compared with healthy volunteers, consistent with the greater experience of lack of control.

  14. Action of Interferon: Kinetics and Differential Effects on Viral Functions

    PubMed Central

    Yamazaki, Shudo; Wagner, Robert R.

    1970-01-01

    A highly purified rabbit interferon was tested for its capacity to inhibit various manifestations of infection of primary rabbit kidney (RK) cells with vesicular stomatitis (VS) virus. A kinetic analysis of the actinomycin-sensitive phase of interferon-induced cellular resistance revealed that RK cells could transcribe virtually all of the hypothetical antiviral messenger ribonucleic acid (mRNA) within 3 hr. Similar exposure to interferon reduced virus yield by 95 to 99% and markedly inhibited cytopathic effect on RK cells infected at a multiplicity of 10 or less. Interferon was less effective in blocking cytopathic effects when RK cells were infected at a multiplicity of 100. However, RK cells pretreated with the same amount of interferon and infected at a multiplicity of 100 failed to incorporate 3H-amino acids into structural or nonstructural proteins of VS virus identified by polyacrylamide gel electrophoresis. Despite this inhibition of viral protein synthesis, interferon did not prevent the switch off by VS virus of cellular protein synthesis. The rapidity with which a high multiplicity of VS virus switched off cellular protein synthesis, even in cells rendered resistant to viral infection by interferon, is further evidence that this reaction is caused by an infecting virion component rather than by a newly synthesized viral product. PMID:5497887

  15. Wogonin prevents immunosuppressive action but not anti-inflammatory effect induced by glucocorticoid.

    PubMed

    Enomoto, Riyo; Suzuki, Chie; Koshiba, Chika; Nishino, Takayuki; Nakayama, Mikiko; Hirano, Hiroyuki; Yokoi, Toshio; Lee, Eibai

    2007-01-01

    Glucocorticoid, such as dexamethasone, has anti-inflammatory and immunosuppressive action as major pharmacological effects. The latter action caused by lymphocyte apoptosis is not only a therapeutic effect but also an adverse reaction. Wogonin, a plant flavone found in Scutellaria baicalensis Georgi, inhibited dexamethasone-induced apoptotic changes, such as DNA fragmentation, nuclear condensation, phosphatidylserine translocation, and caspase activation in rat thymocytes. Since wogonin inhibited dexamethasone-induced DNA fragmentation in a noncompetitive manner, a target of this flavone is unlikely to be an antagonist of glucocorticoid receptor. Wogonin did not only act as an inhibitor of caspases, but also protected apoptosis induced by other glucocorticoids. Since wogonin reduced one of the major pharmacological effects of dexamethasone, we examined whether this flavone diminishes the anti-inflammatory action, another pharmacological effect. The anti-inflammatory action of dexamethasone was evaluated by carrageenan-induced paw edema model. Although dexamethasone significantly suppressed paw edema induced by carrageenan, wogonin had no effect on the anti-inflammatory action of dexamethasone. These results suggest that wogonin may be a useful compound to reduce the immunosuppressive side effect of glucocorticoid.

  16. N400 effect when a semantic anomaly is detected in action representation. A source localization analysis.

    PubMed

    Balconi, Michela; Vitaloni, Silvia

    2014-02-01

    The strength relationship between action and language was largely discussed. In the present research, we explored this link by considering the cortical response (N400 event-related potential effect) to the semantic incongruence induced by a final anomalous object-related action within an actions' sequence. Seventeen participants performed an explicit task to distinguish congruous from incongruous final target action. Event-related potentials analysis showed a significant N400-like effect more frontally (dorsolateral prefrontal cortex) and temporoparietal (mainly left supramarginal gyrus) distribution in response to incongruous condition. It can be argued that the N400-like effect is similar in nature to the N400, which is generally evoked by linguistic stimuli. Nevertheless, the cortical source analysis (low-resolution electromagnetic tomography) showed significant differences for the cortical generators induced by an action processing. This fact may be explained by assuming that object-related action representation activates a specific cortical network, more directly related to congruous/incongruous object use comprehension in relationship with a specific context.

  17. Effect of tactile stimulation on primary motor cortex excitability during action observation combined with motor imagery.

    PubMed

    Tanaka, Megumi; Kubota, Shinji; Onmyoji, Yusuke; Hirano, Masato; Uehara, Kazumasa; Morishita, Takuya; Funase, Kozo

    2015-07-23

    We aimed to investigate the effects of the tactile stimulation to an observer's fingertips at the moment that they saw an object being pinched by another person on the excitability of observer's primary motor cortex (M1) using transcranial magnetic stimulation (TMS). In addition, the above effects were also examined during action observation combined with the motor imagery. Motor evoked potentials (MEP) were evoked from the subjects' right first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles. Electrical stimulation (ES) inducing tactile sensation was delivered to the subjects' first and second fingertips at the moment of pinching action performed by another person. Although neither the ES nor action observation alone had significant effects on the MEP amplitude of the FDI or ADM, the FDI MEP amplitude which acts as the prime mover during pinching was reduced when ES and action observation were combined; however, no such changes were seen in the ADM. Conversely, that reduced FDI MEP amplitude was increased during the motor imagery. These results indicated that the M1 excitability during the action observation of pinching action combined with motor imagery could be enhanced by the tactile stimulation delivered to the observer's fingertips at the moment corresponding to the pinching being observed.

  18. Effects of calcium antagonists on central actions of ethanol: comparative studies with nifedipine, verapamil and cinnarizine.

    PubMed

    Czarnecka, E; Kubik-Bogucka, E

    1993-11-01

    The effects of nifedipine (17.5 and 50 mg/kg), verapamil (5 and 15 mg/kg) and cinnarizine (75 and 200 mg/kg) on acute toxicity and central actions of ethanol (i.e. ethanol-induced sleep and hypothermia, disturbances of rota-rod performance and spontaneous activity) were investigated in mice. Additionally, effects of these drugs on the development of tolerance to hypothermic and sleep-inducing action of ethanol were studied in rats. Calcium antagonists were given acutely 30 min before ethanol administration, or chronically once daily (lower dose) for 10 days, and on the 11th day the animals received an ethanol injection. Single doses of nifedipine increased the acute toxicity of ethanol and potentiated its central effects. After long-term administration of nifedipine no significant alterations in the central actions of ethanol were observed. Verapamil and cinnarizine antagonized the ethanol-induced sleep and impairment of locomotor activity. Nifedipine did not affect the development of tolerance to hypnotic and hypothermic action of ethanol. Verapamil prevents the development of tolerance to hypnotic action of ethanol, whereas cinnarizine prevents the development of tolerance to the hypnotic and hypothermic action of ethanol.

  19. Effects of tacrolimus on action potential configuration and transmembrane ion currents in canine ventricular cells.

    PubMed

    Szabó, László; Szentandrássy, Norbert; Kistamás, Kornél; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Horváth, Balázs; Magyar, János; Bányász, Tamás; Pál, Balázs; Nánási, Péter P

    2013-03-01

    Tacrolimus is a commonly used immunosuppressive agent which causes cardiovascular complications, e.g., hypertension and hypertrophic cardiomyopathy. In spite of it, there is little information on the cellular cardiac effects of the immunosuppressive agent tacrolimus in larger mammals. In the present study, therefore, the concentration-dependent effects of tacrolimus on action potential morphology and the underlying ion currents were studied in canine ventricular cardiomyocytes. Standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques were applied in myocytes enzymatically dispersed from canine ventricular myocardium. Tacrolimus (3-30 μM) caused a concentration-dependent reduction of maximum velocity of depolarization and repolarization, action potential amplitude, phase-1 repolarization, action potential duration, and plateau potential, while no significant change in the resting membrane potential was observed. Conventional voltage clamp experiments revealed that tacrolimus concentrations ≥3 μM blocked a variety of ion currents, including I(Ca), I(to), I(K1), I(Kr), and I(Ks). Similar results were obtained under action potential voltage clamp conditions. These effects of tacrolimus developed rapidly and were fully reversible upon washout. The blockade of inward currents with the concomitant shortening of action potential duration in canine myocytes is the opposite of those observed previously with tacrolimus in small rodents. It is concluded that although tacrolimus blocks several ion channels at higher concentrations, there is no risk of direct interaction with cardiac ion channels when applying tacrolimus in therapeutic concentrations.

  20. The joint Simon effect depends on perceived agency, but not intentionality, of the alternative action

    PubMed Central

    Stenzel, Anna; Dolk, Thomas; Colzato, Lorenza S.; Sellaro, Roberta; Hommel, Bernhard; Liepelt, Roman

    2014-01-01

    A co-actor's intentionality has been suggested to be a key modulating factor for joint action effects like the joint Simon effect (JSE). However, in previous studies intentionality has often been confounded with agency defined as perceiving the initiator of an action as being the causal source of the action. The aim of the present study was to disentangle the role of agency and intentionality as modulating factors of the JSE. In Experiment 1, participants performed a joint go/nogo Simon task next to a co-actor who either intentionally controlled a response button with own finger movements (agency+/intentionality+) or who passively placed the hand on a response button that moved up and down on its own as triggered by computer signals (agency−/intentionality−). In Experiment 2, we included a condition in which participants believed that the co-actor intentionally controlled the response button with a Brain-Computer Interface (BCI) while placing the response finger clearly besides the response button, so that the causal relationship between agent and action effect was perceptually disrupted (agency−/intentionality+). As a control condition, the response button was computer controlled while the co-actor placed the response finger besides the response button (agency−/intentionality−). Experiment 1 showed that the JSE is present with an intentional co-actor and causality between co-actor and action effect, but absent with an unintentional co-actor and a lack of causality between co-actor and action effect. Experiment 2 showed that the JSE is absent with an intentional co-actor, but no causality between co-actor and action effect. Our findings indicate an important role of the co-actor's agency for the JSE. They also suggest that the attribution of agency has a strong perceptual basis. PMID:25140144

  1. Dynamical tides in general relativity: Effective action and effective-one-body Hamiltonian

    NASA Astrophysics Data System (ADS)

    Steinhoff, Jan; Hinderer, Tanja; Buonanno, Alessandra; Taracchini, Andrea

    2016-11-01

    Tidal effects have an important impact on the late inspiral of compact binary systems containing neutron stars. Most current models of tidal deformations of neutron stars assume that the tidal bulge is directly related to the tidal field generated by the companion, with a constant response coefficient. However, if the orbital motion approaches a resonance with one of the internal modes of the neutron star, this adiabatic description of tidal effects starts to break down, and the tides become dynamical. In this paper, we consider dynamical tides in general relativity due to the quadrupolar fundamental oscillation mode of a neutron star. We devise a description of the effects of the neutron star's finite size on the orbital dynamics based on an effective point-particle action augmented by dynamical quadrupolar degrees of freedom. We analyze the post-Newtonian and test-particle approximations of this model and incorporate the results into an effective-one-body Hamiltonian. This enables us to extend the description of dynamical tides over the entire inspiral. We demonstrate that dynamical tides give a significant enhancement of matter effects compared to adiabatic tides, at least for neutron stars with large radii and for low mass-ratio systems, and should therefore be included in accurate models for gravitational-wave data analysis.

  2. Effective Swimmer’s Action during the Grab Start Technique

    PubMed Central

    Mourão, Luis; de Jesus, Karla; Roesler, Hélio; Machado, Leandro J.; Fernandes, Ricardo J.; Vilas-Boas, João Paulo; Vaz, Mário A. P.

    2015-01-01

    The external forces applied in swimming starts have been often studied, but using direct analysis and simple interpretation data processes. This study aimed to develop a tool for vertical and horizontal force assessment based on the swimmers’ propulsive and structural forces (passive forces due to dead weight) applied during the block phase. Four methodological pathways were followed: the experimented fall of a rigid body, the swimmers’ inertia effect, the development of a mathematical model to describe the outcome of the rigid body fall and its generalization to include the effects of the inertia, and the experimental swimmers’ starting protocol analysed with the inclusion of the developed mathematical tool. The first three methodological steps resulted in the description and computation of the passive force components. At the fourth step, six well-trained swimmers performed three 15 m maximal grab start trials and three-dimensional (3D) kinetic data were obtained using a six degrees of freedom force plate. The passive force contribution to the start performance obtained from the model was subtracted from the experimental force due to the swimmers resulting in the swimmers’ active forces. As expected, the swimmers’ vertical and horizontal active forces accounted for the maximum variability contribution of the experimental forces. It was found that the active force profile for the vertical and horizontal components resembled one another. These findings should be considered in clarifying the active swimmers’ force variability and the respective geometrical profile as indicators to redefine steering strategies. PMID:25978370

  3. Evolution of the violin: The law of effect in action.

    PubMed

    Wasserman, Edward A; Cullen, Patrick

    2016-01-01

    As is true for most other human inventions, the origin of the violin is unknown. What is known is that this popular and versatile instrument has notably changed over the course of several hundred years. At issue is whether those evolutionary changes in the construction of the violin are the result of premeditated, intelligent design or whether they arose through a trial-and-error process. Recent scientific evidence favors the latter account. Our perspective piece puts these recent empirical findings into a comprehensive selectionist framework. According to this view, the many things we do and make--like violins--arise from a process of variation and selection which accords with the law of effect. Contrary to popular opinion, there is neither mystique nor romance in this process; it is as fundamental and ubiquitous as the law of natural selection. As with the law of natural selection in the evolution of organisms, there is staunch resistance to the role of the law of effect in the evolution of human inventions. We conclude our piece by considering several objections to our perspective.

  4. Effect of phorbol esters on mitochondrial actions of glucagon

    SciTech Connect

    Cardellach, F.; Moehren, G.; Hoek, J.B.

    1987-05-01

    Glucagon generates different second messenger signals in liver. It increases cAMP levels and elevates cytosolic Ca/sup 2 +/ levels by degradation of polyphosphoinositides. The phorbol ester 12-0-tetradecanoyl phorbol 13-acetate (TPA) inhibits glucagon-induced calcium mobilization, but not cAMP formation. TPA can thus be used to assess the role of Ca/sup 2 +/ and cAMP in the activation of mitochondrial processes. In isolated hepatocytes, glucagon increased the steady state NAD(P)H level, probably by activating mitochondrial Ca/sup 2 +/ dependent dehydrogenases. TPA inhibited the glucagon-induced NAD(P) reduction without affecting phosphorylase activation. The effects of glucagon and TPA on mitochondrial respiratory activity and calcium retention were tested after isolation of the mitochondria from perfused livers. Electron transport rates were increased by 15-25% and calcium retention time was increased four-fold after glucagon treatment. When livers were pretreated with TPA, glucagon had no effect on electron transport activity, but calcium retention was increased by the same factor. The results suggest that glucagon-induced calcium mobilization is required for the stimulation of the respiratory activity but not for the increased capacity to retain a calcium overload in the mitochondria.

  5. The effects of action observation training and mirror therapy on gait and balance in stroke patients

    PubMed Central

    Lee, Ho Jeong; Kim, Young Mi; Lee, Dong Kyu

    2017-01-01

    [Purpose] The aim of this study was to evaluate the effects of action observation training and mirror therapy to improve on balance and gait function of stroke patients. [Subjects and Methods] The participants were randomly allocated to one of three groups: The action observation training with activity group practiced additional action observation training with activity for three 30-minute session for six weeks (n=12). The mirror therapy with activity group practiced additional mirror therapy with activity for three 30-minute sessions for six weeks (n=11). The only action observation training group practiced additional action observation training for three 30-minute sessions for weeks (n=12). All groups received conventional therapy for five 60-minute sessions over a six-week period. [Results] There were significant improvements in balance and gait function. The action observation training with activity group significantly improved subjects’ static balance. The action observation training with activity group and the mirror therapy with activity group significantly improved subjects’ gait ability. [Conclusion] The activation of mirror neurons combined with a conventional stroke physiotherapy program enhances lower-extremity motor recovery and motor functioning in stroke patients. PMID:28356646

  6. Mode of Action of Shigella Toxin: Effects on Ribosome Structure and Function

    DTIC Science & Technology

    1984-10-18

    clinical symptoms associated with these toxin -producing bacteria are, in part, a result of their effect on protein synthesis. To go one step further...hOC UlL.~ COPY AD_ ____/ iMode of Action of Shigella Toxin : Effects on 00 Ribosome Structure and Function 0Annual Report Tom G. Obrig, Ph.D. October...OF ACTION OF SHIGELLA TOXIN : EFFECTS 2 Aug 83 - 1 Aug 84 ON RIBOSOME STRUCTURE AND FUNCTION 6. PERFORMING ORG. REPORT NUM BER 7. AUTHOR(. ) S

  7. Mode of Action of Shigella Toxin. Effects on Ribosome Structure and Function

    DTIC Science & Technology

    1983-08-15

    accepted that clinical symptoms associated with these toxin -producing bacteria are, in part, a result of their effect on protein synthesis. To go one...NUMBER I Mode of Action of Shigella Toxin : Effects on Ribosome Structure and Function Annual Report STom G. Obrig, Ph.D. 0 August 15, 1983 Supported...REPORT A PERIOD COVERED MODE OF ACTION OF SII(;EI.LA TOXIN : EFFECTS Annual 11/15/82-8/l/83 ON RIBOSOME STRUCTURE AND FUNCTION 6 PERFORMING ORG. REPORT

  8. Spontaneously broken asymptotic symmetries and an effective action for horizon dynamics

    NASA Astrophysics Data System (ADS)

    Eling, Christopher

    2017-02-01

    Asymptotic spacetime symmetries have been conjectured to play an important role in quantum gravity. In this paper we study the breaking of asymptotic symmetries associated with a null horizon boundary. In two-dimensions, these symmetries are reparametrizations of the time parameter on the horizon. We show how this horizon reparametrization symmetry is explicitly and spontaneously broken in dilaton gravity and construct an effective action for these pseudo-Goldstone modes using the on-shell gravitational action for a null boundary. The variation of this action yields the horizon constraint equation. This action is invariant under a 2 parameter subgroup of SL(2) transformations, whose Noether charges we interpret via the membrane paradigm. We place these results in the context of recent work on the near AdS2/ near CFT1 correspondence. In this setting the horizon action characterizes the infrared regime near the horizon and has a hydrodynamical sigma model form. We also discuss our construction in General Relativity. In the three-dimensional case there is a natural generalization of our results. However, in higher dimensions, the variation of the effective action only yields the Raychaudhuri equation for small perturbations of the horizon.

  9. Effects of sparfloxacin, grepafloxacin, moxifloxacin, and ciprofloxacin on cardiac action potential duration.

    PubMed

    Patmore, L; Fraser, S; Mair, D; Templeton, A

    2000-10-20

    Fluoroquinolone antibiotics have been associated with QT prolongation following administration to humans. This study compares the effects of four fluoroquinolones, sparfloxacin, grepafloxacin, moxifloxacin and ciprofloxacin on action potential duration recorded from canine isolated cardiac Purkinje fibres. Left and right ventricular Purkinje fibres were isolated from canine hearts and continuously superfused with physiological salt solution. Action potential duration at 90% repolarization was recorded via intracellular microelectrodes. Sparfloxacin, grepafloxacin, moxifloxacin and ciprofloxacin prolonged action potential duration in a concentration dependent manner. Mean concentrations causing a 15% prolongation of action potential duration recorded at a stimulation frequency of 1 Hz were: sparfloxacin 4.2+/-0.7 microg/ml; grepafloxacin 9.3+/-0.9 microg/ml; moxifloxacin 9.9+/-1.6 microg/ml and ciprofloxacin 72.8+/-26.4 microg/ml. Prolongation was inverse frequency dependent with larger increases in action potential duration occurring when the stimulation frequency was reduced to 0.5 Hz. These results indicate that effects on action potential duration vary within this class of compound. Rank order of potency was sparfloxacin > grepafloxacin = moxifloxacin > ciprofloxacin.

  10. Effective Global Action on Antibiotic Resistance Requires Careful Consideration of Convening Forums.

    PubMed

    Rizvi, Zain; Hoffman, Steven J

    2015-01-01

    Global collective action is needed to address the growing transnational threat of antibiotic resistance (ABR). Some commentators have recommended an international legal agreement as the most promising mechanism for coordinating such action. While much has been said about what must be done to address ABR, far less work has analyzed how or where such collective action should be facilitated - even though the success of any international agreement depends greatly on where it is negotiated and implemented. This article evaluates four different forums that states may use to develop an international legal agreement for antibiotic resistance: (1) a self-organized venue; (2) the World Health Organization; (3) the World Trade Organization; and (4) the United Nations General Assembly. The need for a multisectoral approach and the diverse institutional landscape suggest that an effective response may best be coordinated through linked action pursued through multiple forums.

  11. Effect of Action Video Games on the Spatial Distribution of Visuospatial Attention

    ERIC Educational Resources Information Center

    Green, C. Shawn; Bavelier, Daphne

    2006-01-01

    The authors investigated the effect of action gaming on the spatial distribution of attention. The authors used the flanker compatibility effect to separately assess center and peripheral attentional resources in gamers versus nongamers. Gamers exhibited an enhancement in attentional resources compared with nongamers, not only in the periphery but…

  12. [Effect of dexamethasone on indomethacin-induced gastric erosion formation upon duration of the hormonal action].

    PubMed

    Podvigina, T T; Morozova, O Iu; Bagaeva, T R; Filaretova, L P

    2009-07-01

    The aim of the study was to verify a dependence of dexamethasone effect on the gastric erosion formation upon duration of the hormonal action. Gastric erosions were induced by indometha cin (35 mg/kg, sc) in male rats after 24-hour fasting. The rats were given a single injection of dexamethasone at a dose of 1 mg/kg and they underwent the ulcerogenic stimulus (indomethacin) at va rious time points after the hormonal injection (1, 6, 12, 18, 24 hours as well as 3, 5, 7 days). The control rats were given dexamethasone vehicle. In 4 hours after indomethacin injection gastric erosions, corticosterone and blood glucose levels, as well as body and thymus weights were examined. The results obtained demonstrate a dependence ofdexamethasone effect on the gastric erosion formation upon duration of its action: dexamethasone attenuated or aggravated indomethacin-induced gastric erosions depending on the time of its injection. Gastroprotective action of dexamethasone was observed in the case of its injection 1, 6, and 12 hours before indomethacin. The further increase in the time interval caused transformation of gastroprotective action of dexamethasone against ulcerogenic effect. The data obtained suggest that a disturbance of carbohydrate regulation accompanied with the signs of catabolic effects of the glucocorticoid may be responsible for the ulcerogenic action of dexamethasone.

  13. THE MAGNESIUM ISOTOPOLOGUES OF MgH IN THE A {sup 2}{Pi}-X {sup 2}{Sigma}{sup +} SYSTEM

    SciTech Connect

    Hinkle, Kenneth H.; Wallace, Lloyd; Ram, Ram S.; Bernath, Peter F.; Sneden, Christopher; Lucatello, Sara E-mail: wallace@noao.edu E-mail: pbernath@odu.edu E-mail: sara.lucatello@oapd.inaf.it

    2013-08-15

    Using laboratory hollow cathode spectra we have identified lines of the less common magnesium isotopologues of MgH, {sup 25}MgH and {sup 26}MgH, in the A {sup 2}{Pi}-X {sup 2}{Sigma}{sup +} system. Based on the previous analysis of {sup 24}MgH, molecular lines have been measured and molecular constants derived for {sup 25}MgH and {sup 26}MgH. Term values and linelists, in both wavenumber and wavelength units, are presented. The A {sup 2}{Pi}-X {sup 2}{Sigma}{sup +} system of MgH is important for measuring the magnesium isotope ratios in stars. Examples of analysis using the new linelists to derive the Mg isotope ratio in a metal poor dwarf and giant are shown.

  14. I don't get you. Action observation effects inverted by kinematic variation.

    PubMed

    González-Perilli, Fernando; Ellis, Rob

    2015-05-01

    Recent studies have reported an intricate interplay between affordance and mirror effects (the imitation of another agent) when participants attend to the concurrent presentation of an object and another agent interacting with it. In the present paper, we compare two experimental settings in which an observed action was presented as a prime for a task involving the categorization of a graspable object. In experiment 1a, the action depicted a reach and grasp gesture whereas in experiment 1b, only the reach phase was presented. This modification led to very different outcomes. Experiment 1a reflected the traditional imitation effect elicited by human motion. Conversely, experiment 1b showed the facilitation of contralateral responses. Affordance effects were found in experiment 1a only for the RVF. Our results support the view that motor simulation processes underlying imitation or joint actions are extremely sensitive to specific phase kinematics.

  15. RG flows in d dimensions, the dilaton effective action, and the a-theorem

    NASA Astrophysics Data System (ADS)

    Elvang, Henriette; Olson, Timothy M.

    2013-03-01

    Motivated by the recent dilaton-based proof of the 4d a-theorem, we study the dilaton effective action for RG flows in d dimensions. When d is even, the action consists of a Wess-Zumino (WZ) term, whose Weyl-variation encodes the trace-anomaly, plus all Weyl-invariants. For d odd, the action consists of Weyl-invariants only. We present explicit results for the flat-space limit of the dilaton effective action in d-dimensions up to and including 8-derivative terms. GJMS-operators from conformal geometry motivate a form of the action that unifies the Weyl-invariants and anomaly-terms into a compact general- d structure. A new feature in 8d is the presence of an 8-derivative Weyl-invariant that pollutes the O( p 8)-contribution from the WZ action to the dilaton scattering amplitudes; this may challenge a dilaton-based proof of an a-theorem in 8d. We use the example of a free massive scalar for two purposes: 1) it allows us to confirm the structure of the d-dimensional dilaton effective action explicitly; we carry out this check for d = 3, 4, 5, . . . , 10; and 2) in 8d we demonstrate how the flow Δ a = a UV - a IR can be extracted systematically from the O( p 8)-amplitudes despite the contamination from the 8-derivative Weyl-invariant. This computation gives a value for the a-anomaly of the 8d free conformal scalar that is shown to match the value obtained from zeta-function regularization of the log-term in the free energy.

  16. Effects of some heavy metals on the action potentials of an identified Helix pomatia photosensitive neuron.

    PubMed

    Kartelija, Gordana; Radenović, Lidija; Todorović, Natasa; Nedeljković, Miodrag

    2005-06-01

    In the photosensitive MB neuron in the left parietal ganglion of Helix pomatia, the onset of light prolongs significantly (by about 40%) the duration of the action potential. The broadening of the action potential after the onset of light was found to be due to its calcium component and could not be induced after blocking Ca(2+) channels by Cd(2+) and Pb(2+) and in absence of Ca(2+) in medium. The blocking effect of both compounds was reversible. It was found that CdCl(2) exhibited a more intense blocking effect than PbCl(2).

  17. The interference effect of men's handling of muscular action figures on a lexical decision task.

    PubMed

    Barlett, Christopher P; Smith, Sara J; Harris, Richard J

    2006-12-01

    It has been shown in previous work [Action figures and men. Sex Roles 53, 877-885] that male participants who handled extremely muscular action figures had lower body esteem than those who did not handle action figures or a Ken doll. However, the internal mechanisms that dictated this effect are unclear. Therefore, the current study extended this previous work by having male participants handle action figures of varying muscularity and completing a lexical decision task with target words that consisted of both positive and negative body words and feeling words in order to determine if males would be primed to think negatively about their bodies and self or if positive thoughts about their bodies and self would be interfered with. The results show that those participants who handled the extremely muscular action figures responded significantly more slowly to feeling positive words (e.g., content, confident) and marginally more slowly to body positive words (e.g., muscle, bicep) than those who did not handle any action figures. Overall, this suggests that the interference of positive words, not the priming of negative words, is the internal mechanism that produces the decreased body image satisfaction after exposure to muscular stimuli. Implications and future research are discussed.

  18. Effects of pioglitazone on cardiac ion currents and action potential morphology in canine ventricular myocytes.

    PubMed

    Kistamás, Kornél; Szentandrássy, Norbert; Hegyi, Bence; Ruzsnavszky, Ferenc; Váczi, Krisztina; Bárándi, László; Horváth, Balázs; Szebeni, Andrea; Magyar, János; Bányász, Tamás; Kecskeméti, Valéria; Nánási, Péter P

    2013-06-15

    Despite its widespread therapeutical use there is little information on the cellular cardiac effects of the antidiabetic drug pioglitazone in larger mammals. In the present study, therefore, the concentration-dependent effects of pioglitazone on ion currents and action potential configuration were studied in isolated canine ventricular myocytes using standard microelectrode, conventional whole cell patch clamp, and action potential voltage clamp techniques. Pioglitazone decreased the maximum velocity of depolarization and the amplitude of phase-1 repolarization at concentrations ≥3 μM. Action potentials were shortened by pioglitazone at concentrations ≥10 μM, which effect was accompanied with significant reduction of beat-to-beat variability of action potential duration. Several transmembrane ion currents, including the transient outward K(+) current (Ito), the L-type Ca(2+) current (ICa), the rapid and slow components of the delayed rectifier K(+) current (IKr and IKs, respectively), and the inward rectifier K(+) current (IK1) were inhibited by pioglitazone under conventional voltage clamp conditions. Ito was blocked significantly at concentrations ≥3 μM, ICa, IKr, IKs at concentrations ≥10 μM, while IK1 at concentrations ≥30 μM. Suppression of Ito, ICa, IKr, and IK1 has been confirmed also under action potential voltage clamp conditions. ATP-sensitive K(+) current, when activated by lemakalim, was effectively blocked by pioglitazone. Accordingly, action potentials were prolonged by 10 μM pioglitazone when the drug was applied in the presence of lemakalim. All these effects developed rapidly and were readily reversible upon washout. In conclusion, pioglitazone seems to be a harmless agent at usual therapeutic concentrations.

  19. Complementary actions.

    PubMed

    Sartori, Luisa; Betti, Sonia

    2015-01-01

    Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person's movements, (ii) to predict another person's future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one's own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception-action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions.

  20. Complementary actions

    PubMed Central

    Sartori, Luisa; Betti, Sonia

    2015-01-01

    Complementary colors are color pairs which, when combined in the right proportions, produce white or black. Complementary actions refer here to forms of social interaction wherein individuals adapt their joint actions according to a common aim. Notably, complementary actions are incongruent actions. But being incongruent is not sufficient to be complementary (i.e., to complete the action of another person). Successful complementary interactions are founded on the abilities: (i) to simulate another person’s movements, (ii) to predict another person’s future action/s, (iii) to produce an appropriate incongruent response which differ, while interacting, with observed ones, and (iv) to complete the social interaction by integrating the predicted effects of one’s own action with those of another person. This definition clearly alludes to the functional importance of complementary actions in the perception–action cycle and prompts us to scrutinize what is taking place behind the scenes. Preliminary data on this topic have been provided by recent cutting-edge studies utilizing different research methods. This mini-review aims to provide an up-to-date overview of the processes and the specific activations underlying complementary actions. PMID:25983717

  1. Covariant and background independent functional RG flow for the effective average action

    NASA Astrophysics Data System (ADS)

    Safari, Mahmoud; Vacca, Gian Paolo

    2016-11-01

    We extend our prescription for the construction of a covariant and background-independent effective action for scalar quantum field theories to the case where momentum modes below a certain scale are suppressed by the presence of an infrared regulator. The key step is an appropriate choice of the infrared cutoff for which the Ward identity, capturing the information from single-field dependence of the ultraviolet action, continues to be exactly solvable, and therefore, in addition to covariance, manifest background independence of the effective action is guaranteed at any scale. A practical consequence is that in this framework one can adopt truncations dependent on the single total field. Furthermore we discuss the necessary and sufficient conditions for the preservation of symmetries along the renormalization group flow.

  2. Opposing history effect of preceding decision and action in the free choice of saccade direction.

    PubMed

    Mochizuki, Kei; Funahashi, Shintaro

    2014-08-15

    When we act voluntarily, we make a decision to do so prior to the actual execution. However, because of the strong tie between decision and action, it has been difficult to dissociate these two processes in an animal's free behavior. In the present study, we tried to characterize the differences in these processes on the basis of their unique history effect. Using simple eye movement tasks in which the direction of a saccade was either instructed by a computer or freely chosen by the subject, we found that the preceding decision and action had different effects on the animal's subsequent behavior. While choosing a direction (previous decision) produced a positive history effect that prompted the choice of the same saccade direction, making a saccadic response to a direction (previous action) produced a negative history effect that discouraged the monkey from choosing the same direction. This result suggests that the history effect in sequential behavior reported in previous studies was a mixture of these two different components. Future studies on decision-making need to consider the importance of the distinction between decision and action in animal behavior.

  3. Intra- and intermodal integration of discrepant visual and proprioceptive action effects.

    PubMed

    Ladwig, Stefan; Sutter, Christine; Müsseler, Jochen

    2013-12-01

    Integration of discrepant visual and proprioceptive action effects puts high demands on the human information processing system. The present study aimed to examine the integration mechanisms for the motor (Exp. 1) and visual modality (Exp. 2). According to theories of common coding, we assumed that visual as well as proprioceptive information is represented within the same cognitive domain and is therefore likely to affect each other (multisensory cross talk). Thus, apart from the often-confirmed visual dominance in multisensory integration, we asked about intra- and intermodal recall of either proprioceptive or visual information and whether there were any differences between the motor and visual modality. In a replication paradigm, we perturbed the relation between hand movements and cursor movements. The task required the (intra- vs. intermodal) replication of an initially performed (seen) hand (cursor) movement in a subsequent motor (visual) replication phase. First, mechanisms of integration were found to be dependent on the output modality. Visual action effects interfered the motor modality, but proprioceptive action effects did not have any effects on the visual modality. Second, however, intermodal integration was more susceptible to interference, and this was found to be independent from the output modality. Third, for the motor modality, the locus of perturbation (perturbation of cursor amplitude or perturbation of hand amplitude) was irrelevant, but for the visual modality, perturbation of hand amplitudes reduced the cross talk. Tool use is one field of application of these kinds of results, since the optimized integration of conflicting action effects is a precondition for using tools successfully.

  4. Effect of an educational game on university students' learning about action potentials.

    PubMed

    Luchi, Kelly Cristina Gaviao; Montrezor, Luís Henrique; Marcondes, Fernanda K

    2017-06-01

    The aim of this study was to evaluate the effect of an educational game that is used for teaching the mechanisms of the action potentials in cell membranes. The game was composed of pieces representing the intracellular and extracellular environments, ions, ion channels, and the Na(+)-K(+)-ATPase pump. During the game activity, the students arranged the pieces to demonstrate how the ions move through the membrane in a resting state and during an action potential, linking the ion movement with a graph of the action potential. To test the effect of the game activity on student understanding, first-year dental students were given the game to play at different times in a series of classes teaching resting membrane potential and action potentials. In all experiments, students who played the game performed better in assessments. According to 98% of the students, the game supported the learning process. The data confirm the students' perception, indicating that the educational game improved their understanding about action potentials.

  5. Perturbing the action observation network during perception and categorization of actions' goals and grips: state-dependency and virtual lesion TMS effects.

    PubMed

    Jacquet, Pierre O; Avenanti, Alessio

    2015-03-01

    Watching others grasping and using objects activates an action observation network (AON), including inferior frontal (IFC), anterior intraparietal (AIP), and somatosensory cortices (S1). Yet, causal evidence of the differential involvement of such AON sensorimotor nodes in representing high- and low-level action components (i.e., end-goals and grip type) is meager. To address this issue, we used transcranial magnetic stimulation-adaptation (TMS-A) during 2 novel action perception tasks. Participants were shown adapting movies displaying a demonstrator performing goal-directed actions with a tool, using either power or precision grips. They were then asked to match the end-goal (Goal-recognition task) or the grip (Grip-recognition task) of actions shown in test pictures to the adapting movies. TMS was administered over IFC, AIP, or S1 during presentation of test pictures. Virtual lesion-like effects were found in the Grip-recognition task where IFC stimulation induced a general performance decrease, suggesting a critical role of IFC in perceiving grips. In the Goal-recognition task, IFC and S1 stimulation differently affected the processing of "adapted" and "nonadapted" goals. These "state-dependent" effects suggest that the overall goal of seen actions is encoded into functionally distinct and spatially overlapping neural populations in IFC-S1 and such encoding is critical for recognizing and understanding end-goals.

  6. Effective Rotations: Action Effects Determine the Interplay of Mental and Manual Rotations

    ERIC Educational Resources Information Center

    Janczyk, Markus; Pfister, Roland; Crognale, Michael A.; Kunde, Wilfried

    2012-01-01

    The last decades have seen a growing interest in the impact of action on perception and other concurrent cognitive processes. One particularly interesting example is that manual rotation actions facilitate mental rotations in the same direction. The present study extends this research in two fundamental ways. First, Experiment 1 demonstrates that…

  7. 14 CFR 1216.321 - Environmental effects abroad of major Federal actions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Environmental effects abroad of major Federal actions. 1216.321 Section 1216.321 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE... multilateral environmental studies, or (3) Concise reviews of environmental issues. (e) When informed of...

  8. 14 CFR 1216.321 - Environmental effects abroad of major Federal actions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Environmental effects abroad of major Federal actions. 1216.321 Section 1216.321 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE... multilateral environmental studies, or (3) Concise reviews of environmental issues. (e) When informed of...

  9. Effects of a Year-Long Newspaper Energy Series on Reader Knowledge and Action.

    ERIC Educational Resources Information Center

    Abbott, Eric A.

    The effects of a year-long newspaper series about energy on peoples' knowledge and actions were assessed in a Wisconsin study. The series consisted of 20 full-page newspaper articles, which appeared at intervals of from three to five weeks. Results, based on responses to a 16-item knowledge test mailed to newspaper subscribers and nonsubscribers…

  10. 14 CFR 1216.321 - Environmental effects abroad of major Federal actions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Environmental effects abroad of major Federal actions. 1216.321 Section 1216.321 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION ENVIRONMENTAL QUALITY Procedures for Implementing the National Environmental Policy Act...

  11. Effects of Movement Velocity and Maximal Concentric and Eccentric Actions on the Bilateral Deficit

    ERIC Educational Resources Information Center

    Dickin, D. Clark; Too, Danny

    2006-01-01

    This study was performed to examine the effects of movement velocity and maximal concentric and eccentric actions on the bilateral deficit. Eighteen female participants performed maximal unilateral and bilateral knee extensions concentrically and eccentrically across six movement velocities (30, 60, 90, 120, 150, and 180[degrees]/s). Repeated…

  12. Effects of the "Positive Action" Program on Indicators of Positive Youth Development among Urban Youth

    ERIC Educational Resources Information Center

    Lewis, Kendra M.; Vuchinich, Samuel; Ji, Peter; DuBois, David L.; Acock, Alan; Bavarian, Niloofar; Day, Joseph; Silverthorn, Naida; Flay, Brian R.

    2016-01-01

    This study evaluated effects of "Positive Action," a school-based social-emotional and character development intervention, on indicators of positive youth development (PYD) among a sample of low-income, ethnic minority youth attending 14 urban schools. The study used a matched-pair, cluster-randomized controlled design at the school…

  13. Toward a Psychophysics of Agency: Detecting Gain and Loss of Control over Auditory Action Effects

    ERIC Educational Resources Information Center

    Repp, Bruno H.; Knoblich, Gunther

    2007-01-01

    Theories of agency--the feeling of being in control of one's actions and their effects--emphasize either perceptual or cognitive aspects. This study addresses both aspects simultaneously in a finger-tapping paradigm. The tasks required participants to detect when synchronization of their taps with computer-controlled tones changed to…

  14. Context Effects on the Processing of Action-Relevant Object Features

    ERIC Educational Resources Information Center

    Girardi, Giovanna; Lindemann, Oliver; Bekkering, Harold

    2010-01-01

    In 4 experiments, we investigated the effects of object affordance in reach-to-grasp actions. Participants indicated whether a depicted small or large object was natural or manmade by means of different object-grasping responses (i.e., with a power or a precision grip). We observed that the size of the depicted object affected the grasping…

  15. The Effects of Single Laban Effort Action Instruction on Undergraduate Conducting Students' Gestural Clarity

    ERIC Educational Resources Information Center

    Hart, John T., Jr.

    2016-01-01

    The purpose of this study was to examine the effects of Laban Effort Action (slash) instruction in an undergraduate conducting class on college wind ensemble member's ratings of conductors' gestural clarity. Participants--undergraduate and graduate wind ensemble members (N = 28)--rated 32 videos of eight undergraduate conducting students who had…

  16. 21 CFR 25.60 - Environmental effects abroad of major agency actions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Environmental effects abroad of major agency actions. 25.60 Section 25.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ENVIRONMENTAL IMPACT CONSIDERATIONS Other Requirements § 25.60 Environmental...

  17. 21 CFR 25.60 - Environmental effects abroad of major agency actions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Environmental effects abroad of major agency actions. 25.60 Section 25.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ENVIRONMENTAL IMPACT CONSIDERATIONS Other Requirements § 25.60 Environmental...

  18. The Effects of the Coordination Support on Shared Mental Models and Coordinated Action

    ERIC Educational Resources Information Center

    Kim, Hyunsong; Kim, Dongsik

    2008-01-01

    The purpose of this study was to examine the effects of coordination support (tool support and tutor support) on the development of shared mental models (SMMs) and coordinated action in a computer-supported collaborative learning environment. Eighteen students were randomly assigned to one of three conditions, including the tool condition, the…

  19. Positive Education for School Leaders: Exploring the Effects of Emotion-Gratitude and Action-Gratitude

    ERIC Educational Resources Information Center

    Waters, Lea; Stokes, Helen

    2015-01-01

    This qualitative study describes the effect of two gratitude interventions designed to trigger emotion-gratitude (gratitude diary) and action-gratitude (gratitude letter) in school leaders. Case study methodology was applied to analyse reflective journals of 27 school leaders. The gratitude diary served to foster a more balanced view of the…

  20. Action Research: Effects of Self-Efficacy Training on Low Achieving Freshmen

    ERIC Educational Resources Information Center

    Haselden, Polly G.; Sanders, Marla; Sturkie, Lindsay

    2012-01-01

    This action research project investigated the effects of self-efficacy training on low achieving high school freshman who were considered to be at risk for academic failure. Six students participated in psycho-educational group counseling sessions for forty-five minutes weekly over the course of a nine-week reporting period. Findings indicated…

  1. Action Naming in Anomic Aphasic Speakers: Effects of Instrumentality and Name Relation

    ERIC Educational Resources Information Center

    Jonkers, Roel; Bastiaanse, Roelien

    2007-01-01

    Many studies reveal effects of verb type on verb retrieval, mainly in agrammatic aphasic speakers. In the current study, two factors that might play a role in action naming in anomic aphasic speakers were considered: the conceptual factor instrumentality and the lexical factor name relation to a noun. Instrumental verbs were shown to be better…

  2. Nonperturbative corrections to 4D string theory effective actions from SL(2,Z) duality and supersymmetry.

    PubMed

    Robles-Llana, Daniel; Rocek, Martin; Saueressig, Frank; Theis, Ulrich; Vandoren, Stefan

    2007-05-25

    We find the D(-1)- and D1-brane instanton contributions to the hypermultiplet moduli space of type IIB string compactifications on Calabi-Yau threefolds. These combine with known perturbative and world sheet instanton corrections into a single modular invariant function that determines the hypermultiplet low-energy effective action.

  3. Characterizing Teaching Effectiveness in the Joint Action Theory in Didactics: An Exploratory Study in Primary School

    ERIC Educational Resources Information Center

    Sensevy, Gérard

    2014-01-01

    This paper presents an exploratory study of two consecutive reading sessions conducted in primary school by two different teachers. Our purpose is twofold. From a theoretical viewpoint, we propose a tentative set of conditions of teaching effectiveness by relying on the Joint Action Theory in Didactics. From a methodological viewpoint, drawing on…

  4. New Perspectives on the Effects of Action on Perceptual and Cognitive Development

    ERIC Educational Resources Information Center

    Rakison, David H.; Woodward, Amanda L.

    2008-01-01

    This special section was motivated by a resurgence in the view that it is impossible to investigate perceptual and cognitive development without considering how it is affected by, and intertwined with, infants' and children's action in the world. This view has long been foundational to the field, yet contemporary investigations of the effects of…

  5. Learned Patterns of Action-Effect Anticipation Contribute to the Spatial Displacement of Continuously Moving Stimuli

    ERIC Educational Resources Information Center

    Jordan, J. Scott; Hunsinger, Matthew

    2008-01-01

    When participants control the horizontal movements of a stimulus and indicate its vanishing point after it unexpectedly vanishes, the perceived vanishing point is displaced beyond the actual vanishing point, and the size of the displacement is directly related to the action-effect anticipation one has to generate to successfully control the…

  6. Using Action Research Interventions to Improve the Effectiveness of an Executive Team

    ERIC Educational Resources Information Center

    McCarty, Timothy

    2010-01-01

    Purpose: The purpose of this study was to conduct an in-depth investigation of an executive team, to determine which internal and external factors impacted the team and to determine in what ways action research interventions improved the team's effectiveness. Methodology: The subjects in this study were seven members of a school district…

  7. Group Effects of Instrumentality and Name Relation on Action Naming in Bilingual Anomic Aphasia

    ERIC Educational Resources Information Center

    Kambanaros, Maria

    2009-01-01

    Verb production in sentences was investigated in two groups of late bilingual Greek-English speakers: individuals with anomic aphasia and a control group. Verb retrieval in sentences was significantly impaired in both languages for the individuals with anomic aphasia. Additional results revealed no effect of instrumentality on action naming in…

  8. Memory for actions: self-performed tasks and the reenactment effect.

    PubMed

    Mulligan, Neil W; Hornstein, Susan L

    2003-04-01

    Encoding action phrases by enactment (self-performed tasks, or SPTs) leads to better memory than does observing actions (experimenter-performed tasks, or EPTs) or hearing action phrases (Engelkamp, 1998). In addition, recognition memory for SPTs is enhanced when test items are reenacted. Experiment 1 demonstrated a reenactment effect for EPTs, as well as for SPTs, indicating that the effect can be based on visual, as well as motoric, feedback. However, the reenactment effect in SPTs was found even when the participants were blindfolded at test (Experiment 2), indicating that the basis for the reenactment effect differs across SPTs and EPTs. Experiments 3 and 4 provided additional evidence that visual feedback is not critical for reenactment recognition in the case of SPTs. In addition, these experiments failed to show a hand congruency effect (enhanced recognition when the same hand enacts at study and at test), indicating that this effect is not as generalizable as the reenactment effect. These results have important implications for the motor-encoding hypothesis of the enactment effect.

  9. THE EFFECTS OF MAINTENANCE ACTIONS ON THE PFDavg OF SPRING OPERATED PRESSURE RELIEF VALVES

    SciTech Connect

    Harris, S.; Gross, R.

    2014-04-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

  10. The Effects of Maintenance Actions on the PFDavg of Spring Operated Pressure Relief Valves

    SciTech Connect

    Harris, S.; Gross, R.; Goble, W; Bukowski, J

    2015-12-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

  11. The Effects of Maintenance Actions on the PFDavg of Spring Operated Pressure Relief Valves

    DOE PAGES

    Harris, S.; Gross, R.; Goble, W; ...

    2015-12-01

    The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accountedmore » for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.« less

  12. Symmetry properties of the effective action for high-energy scattering in QCD

    SciTech Connect

    Kirschner, R. ); Lipatov, L.N. ); Szymanowski, L. )

    1995-01-15

    We study the effective action describing high-energy scattering processes in the multi-Regge limit of QCD, which should provide the starting point for a new attempt to overcome the limitations of the leading logarithmic and the eikonal approximations. The action can be obtained via simple graphical rules or by integrating in the QCD functional integral over momentum modes of gluon and quark fields that do not appear explicitly as scattering or exchanged particles in the considered processes. The supersymmetry is used to obtain the terms in the action involving quark fields from the pure gluonic ones. We observe Weizsaecker-Williams-type relations between terms describing scattering and production of particles.

  13. [Antihypoxic effect of 3-hydroxypyridine and succinic acid derivatives and their nootropic action in alloxan diabetes].

    PubMed

    Volchegorskiĭ, I A; Rassokhina, L M; Miroshnichenko, I Iu

    2011-01-01

    Relationship between the antihypoxic effect of 3-hydroxypyridine and succinic acid derivatives (emoxipine, reamberin and mexidol) and their effect on conditional learning, glycemia, and lipidemia was studied in rats with alloxan-induced diabetes. In parallel, the analogous relationship was investigated for alpha-lipoic acid that is regarded as a "gold standard" in treatment of diabetic neuropathy. It was established that single administration of emoxipine and mexidol in mice in doses equivalent to therapeutic-range doses in humans produces antihypoxic effect manifested by increased resistance to acute hypoxic hypoxia in test animals. Alpha-lipoic acid is inferior to emoxipin and mexidol in the degree of antihypoxic action. Reamberin does not exhibit this effect. The introduction of emoxipin, reamberin, mexidol, and alpha-lipoic acid in rats with alloxan diabetes during 7 or 14 days in doses equivalent to therapeutic-range doses in humans corrects conditional learning disorders in direct relationship with the antihypoxic activity of these drugs. The development of the nootropic effect of emoxipin, mexidol, and alpha-lipoic acid is related to a decrease in hyperglycemia and hyperlipidemia in rats with alloxan diabetes. The nootropic action of reamberin is accompanied by a transient hypoglycemizing effect and aggravation of dyslipidemic disorders. The antihypoxic activity of investigated drugs determines the direction and expression of their lipidemic effect, but is not correlated with the hypoglycemizing action these drugs on test animals with alloxan diabetes.

  14. Effect of purposeful action observation on upper extremity function in stroke patients

    PubMed Central

    Kim, Eunjoo; Kim, KyeongMi

    2015-01-01

    [Purpose] The purpose of this study was to identify the effect of purposeful action observation on upper extremity function in patients with stroke. [Subjects and Methods] Twelve subjects were randomly to either the experimental group or control group. The experimental group underwent occupational therapy and a purposeful action observation program. The control group underwent occupational therapy and placebo treatment in which the subjects performed a purposeful action observation program without actually observing the purposeful actions. The Wolf Motor Function Test was used to measure upper extremity function before and after the intervention in both groups. [Results] Both the experimental and control groups demonstrated improved upper extremity function after the intervention, but there was no significant difference between groups. Compared with before the intervention, the experimental group showed significantly improved upper extremity function after the intervention. [Conclusion] Based on these results, a purposeful action observation program can improve upper extremity function in patients with stroke. In future research, more subjects should be included for evaluation of different treatments. PMID:26504313

  15. Effects of purposeful action observation on kinematic patterns of upper extremity in individuals with hemiplegia

    PubMed Central

    Kim, Eunjoo; Kim, KyeongMi

    2015-01-01

    [Purpose] This study investigated the effects of purposeful action observation on upper extremity kinematic patterns in individuals with hemiplegia. [Subjects and Methods] Twelve patients were recruited in accordance with the inclusion criteria. The experimental group (n=6) was trained with a purposeful action observation program. The control group (n=6) was trained with only purposeful action without action observation. The programs were performed 30 min/session, 5 times per week for 30 sessions in 6 weeks of training. Upper extremity kinematic patterns were measured by a 3-dimensional motion analysis system before and after training, and the results were analyzed. [Results] The experimental group and the control group showed improvements in average velocity, trajectory ratio, and movement degree, but no statistically significant differences were observed between the groups. The experimental group showed statistically significant improvements in average velocity, trajectory ratio after the intervention. The experimental group also showed an improvement in movement degree, but the post-intervention difference was not significant. [Conclusion] The results of this study show that purposeful action observation training program improved the average velocity and trajectory ratio of stroke patients. Further research should enroll more subjects divided into more specific groups for treatment. PMID:26180326

  16. Reducing aggressive intergroup action tendencies: effects of intergroup contact via perceived intergroup threat.

    PubMed

    Schmid, Katharina; Hewstone, Miles; Küpper, Beate; Zick, Andreas; Tausch, Nicole

    2014-01-01

    Two studies tested the prediction that more positive intergroup contact would be associated with reduced aggressive intergroup action tendencies, an effect predicted to occur indirectly via reduced intergroup threat perceptions, and over and above well-established effects of contact on intergroup attitudes. Study 1, using data based on a cross-section of the general population of eight European countries (France, Germany, Hungary, Italy, the Netherlands, Poland, Portugal, and the UK; N = 7,042), examined this hypothesis in the context of aggressive action tendencies towards immigrants. Study 2, using longitudinal data obtained from a general population sample in Northern Ireland, considered effects on aggressive action tendencies between ethno-religious groups in conflict. Both studies confirmed our predictions, showing that while perceived threat was associated with greater intergroup aggressive tendencies, positive intergroup contact was indirectly associated with reduced aggressive action tendencies, via reduced intergroup threat. Findings are discussed in terms of the theoretical contributions of this research for understanding the relationship between intergroup contact and intergroup aggression.

  17. Feature activation during word recognition: action, visual, and associative-semantic priming effects

    PubMed Central

    Lam, Kevin J. Y.; Dijkstra, Ton; Rueschemeyer, Shirley-Ann

    2015-01-01

    Embodied theories of language postulate that language meaning is stored in modality-specific brain areas generally involved in perception and action in the real world. However, the temporal dynamics of the interaction between modality-specific information and lexical-semantic processing remain unclear. We investigated the relative timing at which two types of modality-specific information (action-based and visual-form information) contribute to lexical-semantic comprehension. To this end, we applied a behavioral priming paradigm in which prime and target words were related with respect to (1) action features, (2) visual features, or (3) semantically associative information. Using a Go/No-Go lexical decision task, priming effects were measured across four different inter-stimulus intervals (ISI = 100, 250, 400, and 1000 ms) to determine the relative time course of the different features. Notably, action priming effects were found in ISIs of 100, 250, and 1000 ms whereas a visual priming effect was seen only in the ISI of 1000 ms. Importantly, our data suggest that features follow different time courses of activation during word recognition. In this regard, feature activation is dynamic, measurable in specific time windows but not in others. Thus the current study (1) demonstrates how multiple ISIs can be used within an experiment to help chart the time course of feature activation and (2) provides new evidence for embodied theories of language. PMID:26074836

  18. Priming tool actions: Are real objects more effective primes than pictures?

    PubMed

    Squires, Scott D; Macdonald, Scott N; Culham, Jody C; Snow, Jacqueline C

    2016-04-01

    Humans are faster to grasp an object such as a tool if they have previewed the same object beforehand. This priming effect is strongest when actors gesture the use of the tool rather than simply move it, possibly because the previewed tool activates action-specific routines in dorsal-stream motor networks. Here, we examined whether real tools, which observers could physically act upon, serve as more potent primes than two-dimensional images of tools, which do not afford physical action. Participants were presented with a prime stimulus that could be either a real tool or a visually matched photograph of a tool. After a brief delay, participants interacted with a real tool target, either by 'grasping to move,' or 'grasping to use' it. The identities of the prime and target tools were either the same (congruent trials; e.g., spatula-spatula) or different (incongruent trials; e.g., whisk-spatula). As expected, participants were faster to initiate grasps during trials when they had to move the tool rather than gesture its use. Priming effects were observed for grasp-to-use, but not grasp-to-move, responses. Surprisingly, however, both pictures of tools and real tools primed action responses equally. Our results indicate that tool priming effects are driven by pictorial cues and their implied actions, even in the absence of volumetric cues that reflect the tangibility and affordances of the prime.

  19. Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects

    PubMed Central

    Aravena, Pia; Hurtado, Esteban; Riveros, Rodrigo; Cardona, Juan Felipe; Manes, Facundo; Ibáñez, Agustín

    2010-01-01

    Background Behavioral studies have provided evidence for an action–sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. Methodology/Principal Findings Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. Conclusions/Significance The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration

  20. Actions of Ethanol on Voltage-Sensitive Sodium Channels: Effects on Neurotoxin Binding

    DTIC Science & Technology

    1987-01-01

    Exprnmantal Trherpeutics Ped in I.SA. Actions of Ethanol on Voltage-Sensitive Sodium Channels: Effects on Neurotoxin Binding1 MICHAEL J. MULLIN 2 and... sodium channels. This indirect allosteric mechanism for inhibition of [H]BTX-B binding. effect orethanol was concentration-dependent and was affected...ethanol increased the equilibrium binding constant without af- that ethanol can affect the voltage-sensitive sodium channels in fecting the apparent

  1. [Comparison of the action of 2 effective analgesics. Experimental study: tramadol versus tilidine/naloxone].

    PubMed

    Bromm, B; Herrmann, W M; Scharein, E

    1989-06-10

    In the present study involving healthy test subjects, tilidin/naloxone (Valoron N; VAL) proved to have an analgesic effect roughly twice as pronounced as that of tramadol (TRA). Moreover, the analgesic effect of VAL showed a significantly more rapid onset than did that of TRA. This finding reflects the difference in rate of action of the active substances. In accordance with these findings, VAL is thus the most powerful analgesic presently available on the German market on simple prescription.

  2. Promoting the translation of intentions into action by implementation intentions: behavioral effects and physiological correlates

    PubMed Central

    Wieber, Frank; Thürmer, J. Lukas; Gollwitzer, Peter M.

    2015-01-01

    The present review addresses the physiological correlates of planning effects on behavior. Although intentions to act qualify as predictors of behavior, accumulated evidence indicates that there is a substantial gap between even strong intentions and subsequent action. One effective strategy to reduce this intention–behavior gap is the formation of implementation intentions that specify when, where, and how to act on a given goal in an if-then format (“If I encounter situation Y, then I will initiate action Z!”). It has been proposed that implementation intentions render the mental representation of the situation highly accessible and establish a strong associative link between the mental representations of the situation and the action. These process assumptions have been examined in behavioral research, and in physiological research, a field that has begun to investigate the temporal dynamics of and brain areas involved in implementation intention effects. In the present review, we first summarize studies on the cognitive processes that are central to the strategic automation of action control by implementation intentions. We then examine studies involving critical samples with impaired self-regulation. Lastly, we review studies that have applied physiological measures such as heart rate, cortisol level, and eye movement, as well as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) studies on the neural correlates of implementation intention effects. In support of the assumed processes, implementation intentions increased goal attainment in studies on cognitive processes and in critical samples, modulated brain waves related to perceptual and decision processes, and generated less activity in brain areas associated with effortful action control. In our discussion, we reflect on the status quo of physiological research on implementation intentions, methodological and conceptual issues, related research, and propose future

  3. Dissociating perception from judgment in the action-specific effect of blocking ease on perceived speed.

    PubMed

    Witt, Jessica K; Tenhundfeld, Nathan L; Bielak, Allison A M

    2017-01-01

    The action-specific approach to perception claims that a person's ability to act directly influences perceptual processes related to spatial vision. For example, a person's ability to block a moving ball impacts perceptual judgments of the ball's speed. However, an alternative explanation is that action rather than perception influences judgments. Here, we explore this distinction directly. Our method produces two distinct effects, one that is clearly a judgment-based effect and is based on the outcome of the trial (trial-outcome effect) and one that is under debate as to whether or not it is perceptual and is based on the ease with which the ball can be blocked (paddle-size effect). We explored whether these two effects would produce convergence or dissociations across various populations and manipulations. A dissociation is evidence for two separate underlying processes, whereas if the two effects did not dissociate, this would be consistent with claims that both effects were judgment-based. In Experiment 1, we examined whether older and younger adults would show a dissociation between the two effects given some precedent for older adults to show greater susceptibility to nonperceptual factors in their judgments. In Experiment 2, we used a cover story to excuse poor performance and examined its effects on both types of effects. Both experiments revealed dissociations, suggesting that while one effect is judgment-based, the other effect is not. Coupled with prior research, we conclude that the action-specific effect of ease to block a ball on estimated ball speed is perceptual.

  4. Renormalization-group flow of the effective action of cosmological large-scale structures

    NASA Astrophysics Data System (ADS)

    Floerchinger, Stefan; Garny, Mathias; Tetradis, Nikolaos; Wiedemann, Urs Achim

    2017-01-01

    Following an approach of Matarrese and Pietroni, we derive the functional renormalization group (RG) flow of the effective action of cosmological large-scale structures. Perturbative solutions of this RG flow equation are shown to be consistent with standard cosmological perturbation theory. Non-perturbative approximate solutions can be obtained by truncating the a priori infinite set of possible effective actions to a finite subspace. Using for the truncated effective action a form dictated by dissipative fluid dynamics, we derive RG flow equations for the scale dependence of the effective viscosity and sound velocity of non-interacting dark matter, and we solve them numerically. Physically, the effective viscosity and sound velocity account for the interactions of long-wavelength fluctuations with the spectrum of smaller-scale perturbations. We find that the RG flow exhibits an attractor behaviour in the IR that significantly reduces the dependence of the effective viscosity and sound velocity on the input values at the UV scale. This allows for a self-contained computation of matter and velocity power spectra for which the sensitivity to UV modes is under control.

  5. Entrainment and task co-representation effects for discrete and continuous action sequences.

    PubMed

    van der Wel, Robrecht P R D; Fu, En

    2015-12-01

    A large body of work has established an influence of other people's actions on our own actions. For example, actors entrain to the movements of others, in studies that typically employ continuous movements. Likewise, studies on co-representation have shown that people automatically co-represent a co-actor's task, in studies that typically employ discrete actions. Here we examined entrainment and co-representation within a single task paradigm. Participants sat next to a confederate while simultaneously moving their right hand back and forth between two targets. We crossed whether or not the participant and the confederate moved over an obstacle and manipulated whether participants generated discrete or continuous movement sequences, while varying the space between the actors and whether the actors could see each other's movements. Participants moved higher when the confederate cleared an obstacle than when he did not. For continuous movements, this effect depended on the availability of visual information, as would be expected on the basis of entrainment. In contrast, the co-actor's task modulated the height of discrete movements, regardless of the availability of visual information, which is consistent with co-representation. Space did not have an effect. These results provide new insights into the interplay between co-representation and entrainment for discrete- and continuous-action tasks.

  6. Linear response theory for symmetry improved two particle irreducible effective actions

    NASA Astrophysics Data System (ADS)

    Brown, Michael J.; Whittingham, Ian B.; Kosov, Daniel S.

    2016-05-01

    We investigate the linear response of an O (N ) scalar quantum field theory subject to external perturbations using the symmetry-improved two-particle irreducible effective action (SI-2PIEA) formalism [A. Pilaftsis and D. Teresi, Nucl. Phys. B874, 594 (2013)]. Despite satisfactory equilibrium behavior, we find a number of unphysical effects at the linear response level. Goldstone boson field fluctuations are overdetermined, with the only consistent solution being to set the fluctuations and their driving sources to zero, except for momentum modes where the Higgs and Goldstone self-energies obey a particular relationship. Also Higgs field fluctuations propagate masslessly, despite the Higgs propagator having the correct mass. These pathologies are independent of any truncation of the effective action and still exist even if we relax the overdetermining Ward identities, so long as the constraint is formulated O (N ) covariantly. We discuss possible reasons for the apparent incompatibility of the constraints and linear response approximation and possible ways forward.

  7. Mixed heavy-light matching in the Universal One-Loop Effective Action

    NASA Astrophysics Data System (ADS)

    Ellis, Sebastian A. R.; Quevillon, Jérémie; You, Tevong; Zhang, Zhengkang

    2016-11-01

    Recently, a general result for evaluating the path integral at one loop was obtained in the form of the Universal One-Loop Effective Action. It may be used to derive effective field theory operators of dimensions up to six, by evaluating the traces of matrices in this expression, with the mass dependence encapsulated in the universal coefficients. Here we show that it can account for loops of mixed heavy-light particles in the matching procedure. Our prescription for computing these mixed contributions to the Wilson coefficients is conceptually simple. Moreover it has the advantage of maintaining the universal structure of the effective action, which we illustrate using the example of integrating out a heavy electroweak triplet scalar coupling to a light Higgs doublet. Finally we also identify new structures that were previously neglected in the universal results.

  8. Positive mood + action = negative mood + inaction: effects of general action and inaction concepts on decisions and performance as a function of affect.

    PubMed

    Albarracin, Dolores; Hart, William

    2011-08-01

    General action and inaction concepts have been shown to produce broad, goal-mediated effects on cognitive and motor activity irrespective of the type of activity. The current research tested a model in which action and inaction goals interact with the valence of incidental moods to guide behavior. Over four experiments, participants' moods were manipulated to be positive (happy), neutral, or negative (angry or sad), and then general action, inaction, and neutral concepts were primed. In Experiment 1, action primes increased intellectual performance when participants experienced a positive (happy) or neutral mood, whereas inaction primes increased performance when participants experienced a negative (angry) mood. Including a control-prime condition, Experiments 2 and 3 replicated these results measuring the number of general interest articles participants were willing to read and participants' memory for pictures of celebrities. Experiment 4 replicated the results comparing happiness with sadness and suggested that the effect of the prime's adoption was automatic. Overall, the findings supported an interactive model by which action concepts and positive affect produce the same increases in active behavior as inaction concepts and negative affect.

  9. Positive Mood + Action = Negative Mood + Inaction: Effects of General Action and Inaction Concepts on Decisions and Performance as a Function of Affect

    PubMed Central

    Albarracin, Dolores; Hart, William

    2013-01-01

    General action and inaction concepts have been shown to produce broad, goal-mediated effects on cognitive and motor activity irrespective of the type of activity. The current research tested a model in which action and inaction goals interact with the valence of incidental moods to guide behavior. Over four experiments, participants’ moods were manipulated to be positive (happy), neutral, or negative (angry or sad), and then general action, inaction, and neutral concepts were primed. In Experiment 1, action primes increased intellectual performance when participants experienced a positive (happy) or neutral mood, whereas inaction primes increased performance when participants experienced a negative (angry) mood. Including a control-prime condition, Experiments 2 and 3 replicated these results measuring the number of general interest articles participants were willing to read and participants’ memory for pictures of celebrities. Experiment 4 replicated the results comparing happiness with sadness and suggested that the effect of the prime’s adoption was automatic. Overall, the findings supported an interactive model by which action concepts and positive affect produce the same increases in active behavior as inaction concepts and negative affect. PMID:21859209

  10. The Characteristics of Action Potentials in Primo Vessels and the Effects of Acetylcholine Injection to the Action Potentials

    PubMed Central

    Cho, Seong Jin; Lim, Jaekwan; Yeon, Sun Hee; Kwon, O. Sang; Choi, Kwang-Ho; Choi, Sun-Mi; Ryu, Yeon-Hee

    2013-01-01

    In a previous study, we found that Primo vessels generate different action potentials in smooth muscles, but this study compared the pulse shape to distinguish the two tissues. Thus, a more sophisticated extracellular experiment was performed in this study using an acetylcholine injection; we then observed changes in the amplitude, FWHM (full width at half maximum), and period to explore Primo vessel function. A third type of pulse was recorded for Primo vessels. We observed fast depolarizing and repolarizing phases for this pulse. Further, its FWHM was 30 ms between smooth muscles and neurons. Acetylcholine affected only the period. The amplitude and FWHM were consistent after injection. Primo-vessels generated action potentials at twice the frequency after injection. From the results, we speculate that Primo-vessels perform a role in transferring signals in a different manner, which may be relevant for acupuncture treatment. PMID:23861710

  11. IL-8 inhibits cAMP-stimulated alveolar epithelial fluid transport via a GRK2/PI3K-dependent mechanism

    PubMed Central

    Roux, Jérémie; McNicholas, Carmel M.; Carles, Michel; Goolaerts, Arnaud; Houseman, Benjamin T.; Dickinson, Dale A.; Iles, Karen E.; Ware, Lorraine B.; Matthay, Michael A.; Pittet, Jean-François

    2013-01-01

    Patients with acute lung injury (ALI) who retain maximal alveolar fluid clearance (AFC) have better clinical outcomes. Experimental and small clinical studies have shown that β2-adrenergic receptor (β2AR) agonists enhance AFC via a cAMP-dependent mechanism. However, two multicenter phase 3 clinical trials failed to show that β2AR agonists provide a survival advantage in patients with ALI. We hypothesized that IL-8, an important mediator of ALI, directly antagonizes the alveolar epithelial response to β2AR agonists. Short-circuit current and whole-cell patch-clamping experiments revealed that IL-8 or its rat analog CINC-1 decreases by 50% β2AR agonist-stimulated vectorial Cl− and net fluid transport across rat and human alveolar epithelial type II cells via a reduction in the cystic fibrosis transmembrane conductance regulator activity and biosynthesis. This reduction was mediated by heterologous β2AR desensitization and down-regulation (50%) via the G-protein-coupled receptor kinase 2 (GRK2)/PI3K signaling pathway. Inhibition of CINC-1 restored β2AR agonist-stimulated AFC in an experimental model of ALI in rats. Finally, consistent with the experimental results, high pulmonary edema fluid levels of IL-8 (>4000 pg/ml) were associated with impaired AFC in patients with ALI. These results demonstrate a novel role for IL-8 in inhibiting β2AR agonist-stimulated alveolar epithelial fluid transport via GRK2/PI3K-dependent mechanisms.—Roux, J., McNicholas, C. M., Carles, M., Goolaerts, A., Houseman, B. T., Dickinson, D. A., Iles, K. E., Ware, L. B., Matthay, M. A., Pittet, J.-F. IL-8 inhibits cAMP-stimulated alveolar epithelial fluid transport via a GRK2/PI3K-dependent mechanism. PMID:23221335

  12. Discretization effects and the scalar meson correlator in mixed-action lattice simulations

    SciTech Connect

    Aubin, C.; Laiho, Jack; Van de Water, Ruth S.

    2008-06-01

    We study discretization effects in a mixed-action lattice theory with domain-wall valence quarks and Asqtad-improved staggered sea quarks. At the level of the chiral effective Lagrangian, discretization effects in the mixed-action theory give rise to two new parameters as compared to the lowest order Lagrangian for rooted-staggered fermions - the residual quark mass m{sub res} and the mixed valence-sea meson mass splitting {delta}{sub mix}. We find that m{sub res}, which parametrizes explicit chiral symmetry breaking in the mixed-action theory, is approximately one-quarter the size of our lightest valence quark mass on our coarser lattice spacing and of comparable size to that of simulations by the RBC and UKQCD Collaborations. We also find that the size of {delta}{sub mix} is comparable to the size of the smallest of the staggered meson taste splittings measured by the MILC Collaboration. Because lattice artifacts are different in the valence and sea sectors of the mixed-action theory, they give rise to unitarity-violating effects that disappear in the continuum limit, some of which should be described by mixed-action chiral perturbation theory (MA{chi}PT). Such effects are expected to be mild for many quantities of interest but are expected to be significant in the case of the isovector scalar (a{sub 0}) correlator. Specifically, once the parameters m{sub res}, {delta}{sub mix}, and two others that can be determined from the light pseudoscalar meson spectrum are known, the two-particle intermediate state 'bubble' contribution to the scalar correlator is completely predicted within MA{chi}PT. We find that the behavior of the scalar meson correlator is quantitatively consistent with the MA{chi}PT prediction; this supports the claim that MA{chi}PT describes the dominant unitarity-violating effects in the mixed-action theory and can therefore be used to remove lattice artifacts and recover physical quantities.

  13. Einstein coefficients for rotational lines of the (0,0) band of the NO A2sigma(+)-X2Pi system

    NASA Technical Reports Server (NTRS)

    Reisel, John R.; Carter, Campbell D.; Laurendeau, Normand M.

    1992-01-01

    A summary of the spectroscopic equations necessary for prediction of the molecular transition energies and the Einstein A and B coefficients for rovibronic lines of the gamma(0,0) band of nitric oxide (NO) is presented. The calculated molecular transition energies are all within 0.57/cm of published experimental values; in addition, over 95 percent of the calculated energies give agreement with measured results within 0.25/cm. Einstein coefficients are calculated from the band A00 value and the known Hoenl-London factors and are tabulated for individual rovibronic transitions in the NO A2sigma(+)-X2Pi(0,0) band.

  14. Collisional Removal of OH (X (sup 2)Pi, nu=7) by O2, N2, CO2, and N2O

    NASA Technical Reports Server (NTRS)

    Knutsen, Karen; Dyer, Mark J.; Copeland, Richard A.

    1996-01-01

    Collisional removal rate constants for the OH (X 2PI, nu = 7) radical are measured for the colliders O2, CO2, and N2O, and an upper limit is established for N2. OH(nu = 4) molecules, generated in a microwave discharge flow cell by the reaction of hydrogen atoms with ozone, are excited to v = 7 by the output of a pulsed infrared laser via direct vibrational overtone excitation. The temporal evolution of the P = 7 population is probed as a function of the collider gas partial pressure by a time-delayed pulsed ultraviolet laser. Fluorescence from the B 21 + state is detected in the visible spectral region.

  15. Effectiveness and sustainability of remedial actions for land restoration in Abeokuta urban communities, Ogun State, Nigeria

    NASA Astrophysics Data System (ADS)

    Lawal-Adebowale, Okanlade

    2016-04-01

    Land as a major collective human property faces a great deal of threats and eventual degradation from both natural and human causal factors across the globe. But for the central role of land in human's sustenance and quality living, man cannot afford to lose its natural asset and as such takes mitigating or remedial actions to save and restore his land for sustainable use. In view of this, the study assessed the causal factors of land degradation in urban areas of Abeokuta and effectiveness and sustainability of the taken remedial actions to stem the tide of land degradation in the study area. The selected communities were purposively selected based on the observed prevalence of degraded lands in the areas. A qualitative research approach which encompasses observational techniques - participant/field observation, interactive discussion and photographic capturing, was used for collection of data on land degradation in the study area. A combination of phenomenological, inductive thematic analysis and conversation/discourse analysis was employed for data analysis. The results showed land gradients/slopes, rainfall, run-offs/erosion, land-entrenched foot impacts, sand scraping/mining, poor/absence of drainage system and land covers as causal factors of land degradation in the study area. The employed remedial actions for restoration of degraded land included filling of drenches with sand bags, wood logs, bricks and stones, and sand filling. The study though observed that filling of drenches caused by erosion with rubles/stones and construction of drainage were effective remedial actions, good drainage system was presumed to be the most appropriate and sustainable remedial action for land restoration in the study area.

  16. Effect of Action Video Games on the Spatial Distribution of Visuospatial Attention

    PubMed Central

    Green, C. Shawn; Bavelier, Daphne

    2010-01-01

    The authors investigated the effect of action gaming on the spatial distribution of attention. The authors used the flanker compatibility effect to separately assess center and peripheral attentional resources in gamers versus nongamers. Gamers exhibited an enhancement in attentional resources compared with nongamers, not only in the periphery but also in central vision. The authors then used a target localization task to unambiguously establish that gaming enhances the spatial distribution of visual attention over a wide field of view. Gamers were more accurate than nongamers at all eccentricities tested, and the advantage held even when a concurrent center task was added, ruling out a trade-off between central and peripheral attention. By establishing the causal role of gaming through training studies, the authors demonstrate that action gaming enhances visuospatial attention throughout the visual field. PMID:17154785

  17. Between-person effects on attention and action: Joe and Fred revisited.

    PubMed

    Hayes, Spencer J; Hansen, Steve; Elliott, Digby

    2010-05-01

    Previous study indicates that target-target inhibition of return (IOR) is not restricted to a single nervous system. Specifically, watching another person perform a goal-directed aiming movement engages similar inhibitory processes on a subsequent aiming attempt as if having performed the preceding movement oneself. This between-person effect has been attributed to the mirror neuron system. In the study reported here, we replicated this finding and examined the relative importance of automatic stimulus alerting events and action-observation by dissociating these two influences. This was done by having two people alternately perform sets of two aiming trials to the same equally probable targets. Under some experimental conditions, one or both of the performers moved to a non-illuminated target. In this way, we dissociated the stimulus and observed event under some between-person conditions. Although IOR was greatest when the stimulus and observed events were compatible, both contributed to the between-person inhibitory processes slowing the responses (Experiment 1). The impact of observing another person perform an aiming movement appears to have more to do with realizing a particular spatial goal than seeing the biological motion associated with achieving that goal (Experiment 2). Findings that both the illumination of a visual target signal and the observation of another person's action engage similar attention-action processes are consistent with action-based accounts of visual selective attention.

  18. Supplemental action learning workshops: Understanding the effects of independent and cooperative workshops on students' knowledge

    NASA Astrophysics Data System (ADS)

    Morris, Kathryn Michelle

    Community colleges enroll more than half of the undergraduate population in the United States, thereby retaining students of varying demographics with extracurricular demands differing from traditional four-year university students. Often in a collegiate lecture course, students are limited in their abilities to absorb and process information presented by their instructors due to content-specific cognitive gaps between the instructor and the student (Preszler, 2009). Research has shown that implementation of instructor-facilitated action learning workshops as supplemental instruction may help bridge these cognitive gaps allowing better student conceptualization and dissemination of knowledge (Drake, 2011; Fullilove & Treisman, 1990; Preszler, 2009; Udovic, Morris, Dickman, Postlethwait, & Wetherwax, 2002). The purpose of this study was to determine the effects of cooperative action learning workshops and independent action learning workshops on students' knowledge of specified topics within a General Biology I with lab course. The results of this investigation indicate that implementation of an instructor-facilitated action learning workshop did not affect students' knowledge gain; furthermore, attendance of a particular workshop style (independent or cooperative) did not affect students' knowledge gain.

  19. Coding Controlled and Triggered Cursor Movements as Action Effects: Influences on the Auditory Simon Effect for Wheel-Rotation Responses

    ERIC Educational Resources Information Center

    Wang, Dong-Yuan Debbie; Procter, Robert W.; Pick, David F.

    2007-01-01

    Four experiments investigated influences of irrelevant action effects on response selection in Simon tasks for which tone pitch was relevant and location irrelevant, and responses were clockwise-counterclockwise wheel rotations. When the wheel controlled left-right movement of a cursor in a direction opposite an instructed left-right hand-movement…

  20. Lay Evaluation of Financial Experts: The Action Advice Effect and Confirmation Bias.

    PubMed

    Zaleskiewicz, Tomasz; Gasiorowska, Agata; Stasiuk, Katarzyna; Maksymiuk, Renata; Bar-Tal, Yoram

    2016-01-01

    The goal of this experimental project was to investigate lay peoples' perceptions of epistemic authority (EA) in the field of finance. EA is defined as the extent to which a source of information is treated as evidence for judgments independently of its objective expertise and based on subjective beliefs. Previous research suggested that EA evaluations are biased and that lay people tend to ascribe higher EA to experts who advise action (in the case of medical experts) or confirm clients' expectations (in the case of politicians). However, there has been no research into biases in lay evaluations of financial experts and this project is aimed to fill this gap. Experiment 1 showed that lay people tended to ascribe greater authority to financial consultants who gave more active advice to clients considering taking out a mortgage. Experiment 2 confirmed the action advice effect found in Experiment 1. However, the outcomes of Experiments 2 and - particularly - 3 suggested that this bias might also be due to clients' desire to confirm their own opinions. Experiment 2 showed that the action advice effect was moderated by clients' own opinions on taking loans. Lay people ascribed the greatest EA to the advisor in the scenario in which he advised taking action and where this coincided with the client's positive opinion on the advisability of taking out a loan. In Experiment 3 only participants with a positive opinion on the financial product ascribed greater authority to experts who recommended it; participants whose opinion was negative tended to rate consultants who advised rejecting the product more highly. To conclude, these three experiments revealed that lay people ascribe higher EA to financial consultants who advise action rather than maintenance of the status quo, but this effect is limited by confirmation bias: when the client's a priori opinion is salient, greater authority is ascribed to experts whose advice confirms it. In this sense, results presented in the

  1. Lay Evaluation of Financial Experts: The Action Advice Effect and Confirmation Bias

    PubMed Central

    Zaleskiewicz, Tomasz; Gasiorowska, Agata; Stasiuk, Katarzyna; Maksymiuk, Renata; Bar-Tal, Yoram

    2016-01-01

    The goal of this experimental project was to investigate lay peoples’ perceptions of epistemic authority (EA) in the field of finance. EA is defined as the extent to which a source of information is treated as evidence for judgments independently of its objective expertise and based on subjective beliefs. Previous research suggested that EA evaluations are biased and that lay people tend to ascribe higher EA to experts who advise action (in the case of medical experts) or confirm clients’ expectations (in the case of politicians). However, there has been no research into biases in lay evaluations of financial experts and this project is aimed to fill this gap. Experiment 1 showed that lay people tended to ascribe greater authority to financial consultants who gave more active advice to clients considering taking out a mortgage. Experiment 2 confirmed the action advice effect found in Experiment 1. However, the outcomes of Experiments 2 and – particularly – 3 suggested that this bias might also be due to clients’ desire to confirm their own opinions. Experiment 2 showed that the action advice effect was moderated by clients’ own opinions on taking loans. Lay people ascribed the greatest EA to the advisor in the scenario in which he advised taking action and where this coincided with the client’s positive opinion on the advisability of taking out a loan. In Experiment 3 only participants with a positive opinion on the financial product ascribed greater authority to experts who recommended it; participants whose opinion was negative tended to rate consultants who advised rejecting the product more highly. To conclude, these three experiments revealed that lay people ascribe higher EA to financial consultants who advise action rather than maintenance of the status quo, but this effect is limited by confirmation bias: when the client’s a priori opinion is salient, greater authority is ascribed to experts whose advice confirms it. In this sense, results

  2. Observing Grasping Actions Directed to Emotion-Laden Objects: Effects upon Corticospinal Excitability

    PubMed Central

    Nogueira-Campos, Anaelli A.; Saunier, Ghislain; Della-Maggiore, Valeria; De Oliveira, Laura A. S.; Rodrigues, Erika C.; Vargas, Claudia D.

    2016-01-01

    The motor system is recruited whenever one executes an action as well as when one observes the same action being executed by others. Although it is well established that emotion modulates the motor system, the effect of observing other individuals acting in an emotional context is particularly elusive. The main aim of this study was to investigate the effect induced by the observation of grasping directed to emotion-laden objects upon corticospinal excitability (CSE). Participants classified video-clips depicting the right-hand of an actor grasping emotion-laden objects. Twenty video-clips differing in terms of valence but balanced in arousal level were selected. Motor evoked potentials (MEPs) were then recorded from the first dorsal interosseous using transcranial magnetic stimulation (TMS) while the participants observed the selected emotional video-clips. During the video-clip presentation, TMS pulses were randomly applied at one of two different time points of grasping: (1) maximum grip aperture, and (2) object contact time. CSE was higher during the observation of grasping directed to unpleasant objects compared to pleasant ones. These results indicate that when someone observes an action of grasping directed to emotion-laden objects, the effect of the object valence promotes a specific modulation over the motor system. PMID:27625602

  3. Partially massless higher-spin theory II: one-loop effective actions

    NASA Astrophysics Data System (ADS)

    Brust, Christopher; Hinterbichler, Kurt

    2017-01-01

    We continue our study of a generalization of the D-dimensional linearized Vasiliev higher-spin equations to include a tower of partially massless (PM) fields. We compute one-loop effective actions by evaluating zeta functions for both the "minimal" and "non-minimal" parity-even versions of the theory. Specifically, we compute the log-divergent part of the effective action in odd-dimensional Euclidean AdS spaces for D = 7 through 19 (dual to the a-type conformal anomaly of the dual boundary theory), and the finite part of the effective action in even-dimensional Euclidean AdS spaces for D = 4 through 8 (dual to the free energy on a sphere of the dual boundary theory). We pay special attention to the case D = 4, where module mixings occur in the dual field theory and subtlety arises in the one-loop computation. The results provide evidence that the theory is UV complete and one-loop exact, and we conjecture and provide evidence for a map between the inverse Newton's constant of the partially massless higher-spin theory and the number of colors in the dual CFT.

  4. Complex self-consistent field and multireference single- and double-excitation configuration interaction calculations for the 2Pi(g) resonance state of N2-.

    PubMed

    Honigmann, Michael; Buenker, Robert J; Liebermann, Heinz-Peter

    2006-12-21

    Self-consistent field and multireference single- and double-excitation configuration interaction calculations employing the complex basis function technique are carried out for the (2)Pi(g) resonance state of the N(2) (-) molecule as well as several other anionic resonance states in the neighboring energy region. The results of calculations employing the same method for the (1)S (2s(2)) state of the He atom and the (1)Sigma(g) (+) (sigma(u) (2)) state of the H(2) molecule are found to be in good agreement with those of earlier work. The present theoretical treatment has succeeded for the first time in satisfying the rigorous criterion of the complex variational principle in computing the N(2) (-) resonance states, namely, a cusp in the plots of real versus imaginary components of the corresponding complex energies has been located at each internuclear distance. On this basis, it is found that the open-shell orbital in the lowest-energy adiabatic N(2) (-) resonance state of (2)Pi(g) symmetry changes its character from quite compact at large internuclear distance to relatively diffuse for r<2.3a(0). This is in contrast to all previous theoretical treatments of this system that have not rigorously satisfied the complex variational principle in their determination of this wave function.

  5. Rapid Sensitization of Physiological, Neuronal, and Locomotor Effects of Nicotine: Critical Role of Peripheral Drug Actions

    PubMed Central

    Lenoir, Magalie; Tang, Jeremy S.; Woods, Amina S.

    2013-01-01

    Repeated exposure to nicotine and other psychostimulant drugs produces persistent increases in their psychomotor and physiological effects (sensitization), a phenomenon related to the drugs' reinforcing properties and abuse potential. Here we examined the role of peripheral actions of nicotine in nicotine-induced sensitization of centrally mediated physiological parameters (brain, muscle, and skin temperatures), cortical and VTA EEG, neck EMG activity, and locomotion in freely moving rats. Repeated injections of intravenous nicotine (30 μg/kg) induced sensitization of the drug's effects on all these measures. In contrast, repeated injections of the peripherally acting analog of nicotine, nicotine pyrrolidine methiodide (nicotinePM, 30 μg/kg, i.v.) resulted in habituation (tolerance) of the same physiological, neuronal, and behavioral measures. However, after repeated nicotine exposure, acute nicotinePM injections induced nicotine-like physiological responses: powerful cortical and VTA EEG desynchronization, EMG activation, a large brain temperature increase, but weaker hyperlocomotion. Additionally, both the acute locomotor response to nicotine and nicotine-induced locomotor sensitization were attenuated by blockade of peripheral nicotinic receptors by hexamethonium (3 mg/kg, i.v.). These data suggest that the peripheral actions of nicotine, which precede its direct central actions, serve as a conditioned interoceptive cue capable of eliciting nicotine-like physiological and neural responses after repeated nicotine exposure. Thus, by providing a neural signal to the CNS that is repeatedly paired with the direct central effects of nicotine, the drug's peripheral actions play a critical role in the development of nicotine-induced physiological, neural, and behavioral sensitization. PMID:23761889

  6. Effects of ropinirole on action potential characteristics and the underlying ion currents in canine ventricular myocytes.

    PubMed

    Simkó, József; Szentandrássy, Norbert; Harmati, Gábor; Bárándi, László; Horváth, Balázs; Magyar, János; Bányász, Tamás; Lorincz, István; Nánási, Péter P

    2010-09-01

    In spite of its widespread clinical application, there is little information on the cellular cardiac effects of the dopamine receptor agonist ropinirole. In the present study, therefore, the concentration-dependent effects of ropinirole on action potential morphology and the underlying ion currents were studied in enzymatically dispersed canine ventricular cardiomyocytes using standard microelectrode, conventional whole-cell patch clamp, and action potential voltage clamp techniques. At concentrations > or = 1 microM, ropinirole increased action potential duration (APD(90)) and suppressed the rapid delayed rectifier K(+) current (I (Kr)) with an IC(50) value of 2.7 +/- 0.25 microM and Hill coefficient of 0.92 +/- 0.09. The block increased with increasing depolarizations to more positive voltages, but paradoxically, the activation of I (Kr) was accelerated by 3 muM ropinirole (time constant decreased from 34 +/- 4 to 14 +/- 1 ms). No significant changes in the fast and slow deactivation time constants were observed with ropinirole. At higher concentrations, ropinirole decreased the amplitude of early repolarization (at concentrations > or = 10 microM), reduced the maximum rate of depolarization and caused depression of the plateau (at concentrations > or = 30 microM), and shortened APD measured at 50% repolarization (at 300 microM) indicating a concentration-dependent inhibition of I (to), I (Na), and I (Ca). Suppression of I (Kr), I (to), and I (Ca) has been confirmed under conventional patch clamp and action potential voltage clamp conditions. I (Ks) and I (K1) were not influenced significantly by ropinirole at concentrations less than 300 microM. All these effects of ropinirole were fully reversible upon washout. The results indicate that ropinirole treatment may carry proarrhythmic risk for patients with inherited or acquired long QT syndrome due to inhibition of I (Kr)-especially in cases of accidental overdose or intoxication.

  7. The effect of adrenaline on the temperature dependency of cardiac action potentials in pink salmon Oncorhynchus gorbuscha.

    PubMed

    Ballesta, S; Hanson, L M; Farrell, A P

    2012-04-01

    Using sharp electrode impalement, action potentials recorded from atrial and ventricular tissue of pink salmon Oncorhynchus gorbuscha generally decreased in duration with increasing test temperature (6, 10, 16 and 20° C). Stimulation of the tissue using 500 nM adrenaline had no significant effect on the duration of the atrial action potential at any test temperature but lengthened the ventricular action potential by ~17%.

  8. Effect of membrane structure on the action of polyenes: I. Nystatin action in cholesterol- and ergosterol-containing membranes.

    PubMed

    Récamier, K S; Hernández-Gómez, A; González-Damián, J; Ortega-Blake, I

    2010-09-01

    A detailed and thorough characterization of nystatin-induced permeability on lipid bilayers of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)-containing ergosterol or cholesterol is presented. The results show that the same collection of transmembrane pores appears in membranes containing either sterol. The concentration range for the appearance of these pores is sterol-dependent. Another mechanism of action, membrane disruption, is also observed in ergosterol-POPC membranes. The greater potency of nystatin present in ergosterol-containing membranes cannot be explained simply by the longer opening times of its pores, as has been suggested; it is also due to an increased number of events in these membranes. The present results and those of a companion paper lead us to propose that membrane structure is the determining factor for drug selectivity in membranes with different sterols.

  9. Rapid and estrogen receptor beta mediated actions in the hippocampus mediate some functional effects of estrogen

    PubMed Central

    Walf, Alicia A.; Frye, Cheryl A.

    2008-01-01

    The steroid hormone, estradiol (E2), has numerous targets in the central nervous system, including the hippocampus, which plays a key role in cognition and affective behavior. This review focuses on our evidence from studies in rodents that E2 has diverse mechanisms in the hippocampus for its functional effects E2 has rapid, membrane-mediated effects in the hippocampus to enhance cognitive performance. Administration of E2 to the hippocampus of rats for 10 minutes following training enhances performance in a hippocampus-mediated task. Increased cell firing in the hippocampus occurs within this short time frame. Furthermore, administration of free E2 or an E2 conjugate, E2:bovine serum albumin (BSA), to the hippocampus produces similar performance-enhancing effects in this task, suggesting that E2 has membrane actions in the hippocampus for these effects. Further evidence that E2 has rapid, membrane-mediated effects is that co-administration of E2 and inhibitors of mitogen activated protein kinase (MAPK), rather than intracellular E2 receptors (ERs) or protein synthesis, attenuate the enhancing effects of E2 in this task. Despite these data that demonstrate E2 can have rapid and/or membrane-mediated effects in the hippocampus, there is clear evidence to suggest that intracellular ERs, particularly the β (rather than α) isoform of ERs, may be important targets for E2’s functional effects for hippocampal processes. Administration of ligands that are specific for ERβ, but not ERα, have enhancing effects on hippocampal processes similar to that of E2 (which has similar affinity for ERα and ERβ). These effects are attenuated when ERβ expression is knocked down in transgenic models or with central administration of antisense oligonucleotides. Thus, there may be a convergence of E2’s actions through rapid, membrane-mediated effects and intracellular ERs and in the hippocampus for these functional effects. PMID:18342348

  10. Learning to Control Actions: Transfer Effects following a Procedural Cognitive Control Computerized Training

    PubMed Central

    Shahar, Nitzan; Meiran, Nachshon

    2015-01-01

    Few studies have addressed action control training. In the current study, participants were trained over 19 days in an adaptive training task that demanded constant switching, maintenance and updating of novel action rules. Participants completed an executive functions battery before and after training that estimated processing speed, working memory updating, set-shifting, response inhibition and fluid intelligence. Participants in the training group showed greater improvement than a no-contact control group in processing speed, indicated by reduced reaction times in speeded classification tasks. No other systematic group differences were found across the different pre-post measurements. Ex-Gaussian fitting of the reaction-time distribution revealed that the reaction time reduction observed among trained participants was restricted to the right tail of the distribution, previously shown to be related to working memory. Furthermore, training effects were only found in classification tasks that required participants to maintain novel stimulus-response rules in mind, supporting the notion that the training improved working memory abilities. Training benefits were maintained in a 10-month follow-up, indicating relatively long-lasting effects. The authors conclude that training improved action-related working memory abilities. PMID:25799443

  11. New Insights into the Mechanisms of Action of Cotinine and its Distinctive Effects from Nicotine.

    PubMed

    Grizzell, J Alex; Echeverria, Valentina

    2015-10-01

    Tobacco consumption is far higher among a number of psychiatric and neurological diseases, supporting the notion that some component(s) of tobacco may underlie the oft-reported reduction in associated symptoms during tobacco use. Popular dogma holds that this component is nicotine. However, increasing evidence support theories that cotinine, the main metabolite of nicotine, may underlie at least some of nicotine's actions in the nervous system, apart from its adverse cardiovascular and habit forming effects. Though similarities exist, disparate and even antagonizing actions between cotinine and nicotine have been described both in terms of behavior and physiology, underscoring the need to further characterize this potentially therapeutic compound. Cotinine has been shown to be psychoactive in humans and animals, facilitating memory, cognition, executive function, and emotional responding. Furthermore, recent research shows that cotinine acts as an antidepressant and reduces cognitive-impairment associated with disease and stress-induced dysfunction. Despite these promising findings, continued focus on this potentially safe alternative to tobacco and nicotine use is lacking. Here, we review the effects of cotinine, including comparisons with nicotine, and discuss potential mechanisms of cotinine-specific actions in the central nervous system which are, to date, still being elucidated.

  12. Motivating Exercise: The Interactive Effect of General Action Goals and Past Behavior on Physical Activity.

    PubMed

    Hepler, Justin; Wang, Wei; Albarracin, Dolores

    2012-09-01

    Although exercise is recognized as a powerful tool to combat obesity, remarkably few US adults pursue adequate amounts of exercise, with one major impediment being a lack of motivation for active behaviors. Recent empirical work has demonstrated that behavior can be guided by goals to be generally active or inactive. In the present paper, an experiment is presented in which participants played or observed a video game, were primed with action or inaction goals, and practiced a stretching exercise for as long as desired. Exposure to environmental action cues led to increased time spent exercising. This effect was moderated by past behavior, such that individuals who had just engaged in an active task (played a videogame) were insensitive to attempts to motivate general action. This suggests that the effectiveness of attempts to motivate activity ("just do it", "be active") hinges on the recent past-behavior of the targeted individuals. An implication of this work is that participation in certain leisure activities, such as playing videogames, may be causally related to a lack of motivation for exercise.

  13. Motivating Exercise: The Interactive Effect of General Action Goals and Past Behavior on Physical Activity

    PubMed Central

    Hepler, Justin; Wang, Wei; Albarracin, Dolores

    2013-01-01

    Although exercise is recognized as a powerful tool to combat obesity, remarkably few US adults pursue adequate amounts of exercise, with one major impediment being a lack of motivation for active behaviors. Recent empirical work has demonstrated that behavior can be guided by goals to be generally active or inactive. In the present paper, an experiment is presented in which participants played or observed a video game, were primed with action or inaction goals, and practiced a stretching exercise for as long as desired. Exposure to environmental action cues led to increased time spent exercising. This effect was moderated by past behavior, such that individuals who had just engaged in an active task (played a videogame) were insensitive to attempts to motivate general action. This suggests that the effectiveness of attempts to motivate activity (“just do it”, “be active”) hinges on the recent past-behavior of the targeted individuals. An implication of this work is that participation in certain leisure activities, such as playing videogames, may be causally related to a lack of motivation for exercise. PMID:23606776

  14. Learning to control actions: transfer effects following a procedural cognitive control computerized training.

    PubMed

    Shahar, Nitzan; Meiran, Nachshon

    2015-01-01

    Few studies have addressed action control training. In the current study, participants were trained over 19 days in an adaptive training task that demanded constant switching, maintenance and updating of novel action rules. Participants completed an executive functions battery before and after training that estimated processing speed, working memory updating, set-shifting, response inhibition and fluid intelligence. Participants in the training group showed greater improvement than a no-contact control group in processing speed, indicated by reduced reaction times in speeded classification tasks. No other systematic group differences were found across the different pre-post measurements. Ex-Gaussian fitting of the reaction-time distribution revealed that the reaction time reduction observed among trained participants was restricted to the right tail of the distribution, previously shown to be related to working memory. Furthermore, training effects were only found in classification tasks that required participants to maintain novel stimulus-response rules in mind, supporting the notion that the training improved working memory abilities. Training benefits were maintained in a 10-month follow-up, indicating relatively long-lasting effects. The authors conclude that training improved action-related working memory abilities.

  15. Effective-action approach to wave propagation in scalar QED plasmas

    NASA Astrophysics Data System (ADS)

    Shi, Yuan; Fisch, Nathaniel J.; Qin, Hong

    2016-07-01

    A relativistic quantum field theory with nontrivial background fields is developed and applied to study waves in plasmas. The effective action of the electromagnetic 4-potential is calculated ab initio from the standard action of scalar QED using path integrals. The resultant effective action is gauge invariant and contains nonlocal interactions, from which gauge bosons acquire masses without breaking the local gauge symmetry. To demonstrate how the general theory can be applied, we give two examples: a cold unmagnetized plasma and a cold uniformly magnetized plasma. Using these two examples, we show that all linear waves well known in classical plasma physics can be recovered from relativistic quantum results when taking the classical limit. In the opposite limit, classical wave dispersion relations are modified substantially. In unmagnetized plasmas, longitudinal waves propagate with nonzero group velocities even when plasmas are cold. In magnetized plasmas, anharmonically spaced Bernstein waves persist even when plasmas are cold. These waves account for cyclotron absorption features observed in spectra of x-ray pulsars. Moreover, cutoff frequencies of the two nondegenerate electromagnetic waves are red-shifted by different amounts. These corrections need to be taken into account in order to correctly interpret diagnostic results in laser plasma experiments.

  16. Effect and evaluation of prying action for top- and seat-angle connections

    NASA Astrophysics Data System (ADS)

    Ahmed, Ali; Hasan, Rafiq

    2015-06-01

    Nonlinear finite element (FE) static analyses of top- and seat-angle connections were performed using ABAQUS standard to investigate the influence of connection parameters and its properties on prying action developed due to the interaction between column flange and top angle's vertical leg. Contact phenomenon between two interfaces with finite sliding and bolt pretension in the initial step of analysis was considered in the FE model. FE analysis results were compared with the experimental ones to examine the applicability of the FE model. Then, the location of plastic hinges in connection assemblages was investigated at the ultimate state of the connection and a parametric study was performed varying connection parameters, material properties of connection assemblages, and magnitude of bolt pretension to visualize their effects on prying force and on the position of prying force on top angle's vertical leg. Current study shows that plastic hinges not only develop at top angle's heel and bolt hole region but also in the bolt shank that differs from some assumptions of power model (Kishi and Chen 1990): (1) top angle thickness and gage distance from angle heel to bolt hole center line have an distinct effect on prying action; and (2) distributed prying force developed near the region of the top edge of tension angle's leg adjacent to column flange can contribute to the failure of the connection. Finally, a mathematical formulation to identify the location of prying force action point is proposed.

  17. Actions of Ethanol on Voltage-Sensitive Sodium Channels: Effects of Acute and Chronic Ethanol Treatment

    DTIC Science & Technology

    1987-01-01

    No. 2 C4"ght 0 1967 by "he Amusca Soiety for Pharmacolog and Kxporuont Therpadu" Prud m U.S.A. Actions of Ethanol on Voltage-Sensitive Sodium ...inhibitory effect of ethanol in vitro on sodium benzoate binding to neuronal sodium channels were studi-d in uptake for up to 20 days after withdrawal...adapt rapidly to some sodium uptake in the absence of ethanol in vitro, however, a effects of ethanol and that chronic ethanol administration can

  18. Natural Products with Anti-obesity Effects and Different Mechanisms of Action.

    PubMed

    Fu, Chuhan; Jiang, Yao; Guo, Jiao; Su, Zhengquan

    2016-12-28

    Obesity, a primary influence on health condition, causes numerous comorbidities and complications and, therefore, pharmacotherapy is considered a strategy for its treatment. However, the adverse effects of most chemical drugs targeting weight loss complicate their approval by regulatory authorities. Recently, interest has increased in the development of ingredients from natural sources with fewer adverse effects for preventing and ameliorating obesity. This review provides an overview of current anti-obesity drugs and natural products with anti-obesity properties as well as their mechanisms of action, which include interfering with nutrient absorption, decreasing adipogenesis, increasing energy expenditure (thermogenesis), appetite suppression, modifying intestinal microbiota composition, and increasing fecal fat excretion.

  19. The Steroidal Glycoalkaloids from Solanaceae: Toxic Effect, Antitumour Activity and Mechanism of Action.

    PubMed

    Sucha, Lenka; Tomsik, Pavel

    2016-03-01

    Steroidal glycoalkaloids present in Solanaceae are toxic compounds biosynthesised for the protection of the plants. However, many health benefits of these compounds have been reported so far. One of their promising targets might be cancer, as demonstrated in a large number of studies. However, the main mechanism of action seems to be unclear. It could include the induction of apoptosis or trigger a necrosis with a subsequent inflammatory response. The relatively high systemic toxicity of steroidal compounds is another effect that must be taken into account in anticancer research. The main aim of this work was to summarise the recent progress in the investigation of the mechanisms of their antitumour action and to discuss their potential.

  20. Stage-specific effects of an action control intervention on dental flossing.

    PubMed

    Schüz, Benjamin; Sniehotta, Falko F; Schwarzer, Ralf

    2007-06-01

    Health behavior interventions may have different effects when targeting individuals at different stages of change. A 'motivation' stage, during which intentions are formed, has been distinguished from a 'volition' stage, implying that the latter requires self-regulatory effort in implementing and maintaining behavior. To test this stage assumption, an action control intervention (self-monitoring tool for dental flossing) matched to the volition stage and mismatched to the motivation stage was provided to 151 university students, with follow-up measures of action control and flossing after 2 and 6 weeks. Separate regression analyses for motivational and volitional participants indicated that only volitional participants benefited from the volitional intervention. This supports the usefulness of stage assumptions and the advantage of tailoring interventions to participants who reside either in the motivational or in the volitional stage.

  1. Effect of Nitrogen Additives on Flame Retardant Action of Tributyl Phosphate: Phosphorus – Nitrogen Synergism

    SciTech Connect

    Gaan, Sabyasachi; Sun, Gang; Hutches, Katherine; Engelhard, Mark H.

    2008-01-01

    The effect of nitrogen additives like urea, guanidine carbonate and melamine formaldehyde on the flame retardant efficacy of tributyl phosphate (TBP) has been investigated. From the LOI tests on treated cotton it is clear that the nitrogen additives have synergistic action. Estimation of activation energy of decomposition of treated cotton indicated that nitrogen additives enhance the thermal stability during the burning process. SEM pictures of chars formed after LOI test showed the formation of protective polymeric coating on the surface. The surface of chars formed were evaluated using FTIR-ATR and XPS analysis which showed that the coating was composed of Phosphorus-Nitrogen-Oxygen containing species. Formation of this coating during the burning process could lead to the synergistic interaction of phosphorus and nitrogen. Based on the experimental data we have further proposed several reaction mechanisms which could contribute to synergistic action and formation of protective coating on the surface of char.

  2. Was it me? - Filling the interval between action and effects increases agency but not sensory attenuation.

    PubMed

    Weller, Lisa; Schwarz, Katharina A; Kunde, Wilfried; Pfister, Roland

    2017-02-01

    Sensory stimuli resulting from one's own actions are perceptually attenuated compared to identical but externally produced stimuli. This may enable the organism to discriminate between self-produced events and externally produced events, suggesting a strong link between sensory attenuation and a subjective sense of agency. To investigate this supposed link, we compared the influence of filled and unfilled action-effect delays on both, judgements of agency for self-produced sounds and attenuation of the event-related potential (ERP). In line with previous findings, judgments of agency differed between both delay conditions with higher ratings for filled than for unfilled delays. Sensory attenuation, however, was not influenced by filling the delay. These findings indicate a partial dissociation of the two phenomena.

  3. Action-specific effects in aviation: what determines judged runway size?

    PubMed

    Gray, Rob; Navia, José Antonio; Allsop, Jonathan

    2014-01-01

    Several recent studies have shown that the performance of a skill that involves acting on a goal object can influence one's judgment of the size of that object. The present study investigated this effect in an aviation context. Novice pilots were asked to perform a series of visual approach and landing manoeuvres in a flight simulator. After each landing, participants next performed a task in which runway size was judged for different simulated altitudes. Gaze behaviour and control stick kinematics were also analyzed. There were significant relationships between judged runway size and multiple action-related variables including touchdown velocity, time fixating the runway, and the magnitude and frequency of control inputs. These findings suggest that relationship between the perception of a target object and action is not solely determined by performance success or failure but rather involves a relationship between multiple variables that reflect the actor's ability.

  4. Differential effects of systemic cholinergic receptor blockade on Pavlovian incentive motivation and goal-directed action selection.

    PubMed

    Ostlund, Sean B; Kosheleff, Alisa R; Maidment, Nigel T

    2014-05-01

    Reward-seeking actions can be guided by external cues that signal reward availability. For instance, when confronted with a stimulus that signals sugar, rats will prefer an action that produces sugar over a second action that produces grain pellets. Action selection is also sensitive to changes in the incentive value of potential rewards. Thus, rats that have been prefed a large meal of sucrose will prefer a grain-seeking action to a sucrose-seeking action. The current study investigated the dependence of these different aspects of action selection on cholinergic transmission. Hungry rats were given differential training with two unique stimulus-outcome (S1-O1 and S2-O2) and action-outcome (A1-O1 and A2-O2) contingencies during separate training phases. Rats were then given a series of Pavlovian-to-instrumental transfer tests, an assay of cue-triggered responding. Before each test, rats were injected with scopolamine (0, 0.03, or 0.1 mg/kg, intraperitoneally), a muscarinic receptor antagonist, or mecamylamine (0, 0.75, or 2.25 mg/kg, intraperitoneally), a nicotinic receptor antagonist. Although the reward-paired cues were capable of biasing action selection when rats were tested off-drug, both anticholinergic treatments were effective in disrupting this effect. During a subsequent round of outcome devaluation testing-used to assess the sensitivity of action selection to a change in reward value--we found no effect of either scopolamine or mecamylamine. These results reveal that cholinergic signaling at both muscarinic and nicotinic receptors mediates action selection based on Pavlovian reward expectations, but is not critical for flexibly selecting actions using current reward values.

  5. Variations in onset of action potential broadening: effects on calcium current studied in chick ciliary ganglion neurones.

    PubMed

    Pattillo, J M; Artim, D E; Simples, J E; Meriney, S D

    1999-02-01

    1. The voltage dependence and kinetic properties of stage 40 ciliary ganglion calcium currents were determined using short (10 ms) voltage steps. These properties aided the interpretation of the action potential-evoked calcium current described below, and the comparison of our data with those observed in other preparations. 2. Three different natural action potential waveforms were modelled by a series of ramps to generate voltage clamp commands. Calcium currents evoked by these model action potentials were compared before and after alterations in the repolarization phase of each action potential. 3. Abrupt step repolarizations from various time points were used to estimate the time course of calcium current activation during each action potential. Calcium current evoked by fast action potentials (duration at half-amplitude, 0.5 or 1.0 ms) did not reach maximal activation until the action potential had repolarized by 40-50 %. In contrast, calcium current evoked by a slow action potential (duration at half-amplitude, 2.2 ms) was maximally activated near the peak of the action potential. 4. Slowing the rate of repolarization of the action potential (broadening) from different times was used to examine effects on peak and total calcium influx. With all three waveforms tested, broadening consistently increased total calcium influx (integral). However, peak calcium current was either increased or decreased depending on the duration of the control action potential tested and the specific timing of the initiation of broadening the repolarization phase. 5. The opposite effects on peak calcium current observed with action potential broadening beginning at different time points in repolarization may provide a mechanism for the variable effects of potassium channel blockers on transmitter release magnitude.

  6. Test of a model of antiarrhythmic drug action. Effects of quinidine and lidocaine on myocardial conduction.

    PubMed

    Hondeghem, L; Katzung, B G

    1980-06-01

    The effects of quinidine and lidocaine on the maximum upstroke velocity (Vmax) of the ventricular myocardial action potential were compared with the effects predicted by a model over a wide range of driving rates, rhythm disturbances and holding potentials. These rate-, rhythm- and voltage-dependent effects were accurately predicted by the proposed model. The model was also able to predict several previously undocumented properties of the drugs: 1) If lidocaine decreases Vmax of a pulse train, the steady state is reached within a few action potentials. 2) The poststimulation recovery of Vmax in the presence of lidocaine or quinidine can occur in a multiexponential fashion, if the membrane potential is kept at the potential where both the fast (operating mainly at more negative membrane potentials) and the slow (operating at more positive potentials) recovery processes are operative. 3) Hyperpolarization markedly attenuates the rate-dependent drug effects. 4) Combinations of lidocaine and quinidine have a superadditive effect on the Vmax of early extrasystoles.

  7. Effects of acoustic noise on the auditory nerve compound action potentials evoked by electric pulse trains.

    PubMed

    Nourski, Kirill V; Abbas, Paul J; Miller, Charles A; Robinson, Barbara K; Jeng, Fuh-Cherng

    2005-04-01

    This study investigated the effects of acoustic noise on the auditory nerve compound action potentials in response to electric pulse trains. Subjects were adult guinea pigs, implanted with a minimally invasive electrode to preserve acoustic sensitivity. Electrically evoked compound action potentials (ECAP) were recorded from the auditory nerve trunk in response to electric pulse trains both during and after the presentation of acoustic white noise. Simultaneously presented acoustic noise produced a decrease in ECAP amplitude. The effect of the acoustic masker on the electric probe was greatest at the onset of the acoustic stimulus and it was followed by a partial recovery of the ECAP amplitude. Following cessation of the acoustic noise, ECAP amplitude recovered over a period of approximately 100-200 ms. The effects of the acoustic noise were more prominent at lower electric pulse rates (interpulse intervals of 3 ms and higher). At higher pulse rates, the ECAP adaptation to the electric pulse train alone was larger and the acoustic noise, when presented, produced little additional effect. The observed effects of noise on ECAP were the greatest at high electric stimulus levels and, for a particular electric stimulus level, at high acoustic noise levels.

  8. UV action spectra for mammalian systems: their implications for the predicted effects of ozone depletion on skin cancer incidence

    SciTech Connect

    Setlow, R.B.

    1982-01-01

    The predicted environmental effect of UV-B depend on the action spectrum for the response studied. Since such spectra change rapidly - usually decreasing with increasing wavelength - and since the biological effects depend on the product of the action spectrum and the sun's spectrum at the surface of the earth which decreases with decreasing wavelength, a slight change in action spectrum will markedly influence the predicted effects of ozone depletion on biological systems. Thus, the key, but by no means only step in the prediction, is a knowledge of the action spectrum. Unfortunately, it is rare that we know or even hope to know the spectrum for biological systems of interest such as skin cancer induction, nor is it possible to do experiments with solar simulators on many systems. Hence, we must base our predictions on the photobiological properties of simple systems and the knowledge of their action spectra and general biological theories connecting simple cells with higher organisms.

  9. 10 CFR 2.1327 - Application for a stay of the effectiveness of NRC staff action on license transfer.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... action on license transfer. 2.1327 Section 2.1327 Energy NUCLEAR REGULATORY COMMISSION AGENCY RULES OF PRACTICE AND PROCEDURE Procedures for Hearings on License Transfer Applications § 2.1327 Application for a stay of the effectiveness of NRC staff action on license transfer. (a) Any application for a stay...

  10. 10 CFR 2.1327 - Application for a stay of the effectiveness of NRC staff action on license transfer.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... action on license transfer. 2.1327 Section 2.1327 Energy NUCLEAR REGULATORY COMMISSION AGENCY RULES OF PRACTICE AND PROCEDURE Procedures for Hearings on License Transfer Applications § 2.1327 Application for a stay of the effectiveness of NRC staff action on license transfer. (a) Any application for a stay...

  11. 10 CFR 2.1327 - Application for a stay of the effectiveness of NRC staff action on license transfer.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... action on license transfer. 2.1327 Section 2.1327 Energy NUCLEAR REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS AND ISSUANCE OF ORDERS Procedures for Hearings on License Transfer Applications § 2.1327 Application for a stay of the effectiveness of NRC staff action on license transfer....

  12. 10 CFR 2.1327 - Application for a stay of the effectiveness of NRC staff action on license transfer.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... action on license transfer. 2.1327 Section 2.1327 Energy NUCLEAR REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS AND ISSUANCE OF ORDERS Procedures for Hearings on License Transfer Applications § 2.1327 Application for a stay of the effectiveness of NRC staff action on license transfer....

  13. Bridging the Gap between the Other and Me: The Functional Role of Motor Resonance and Action Effects in Infants' Imitation

    ERIC Educational Resources Information Center

    Paulus, Markus; Hunnius, Sabine; Vissers, Marlies; Bekkering, Harold

    2011-01-01

    This paper investigates a two-stage model of infants' imitative learning from observed actions and their effects. According to this model, the observation of another person's action activates the corresponding motor code in the infants' motor repertoire (i.e. leads to motor resonance). The second process guiding imitative behavior results from the…

  14. The effect of carbohydrate availability following exercise on whole-body insulin action.

    PubMed

    Holtz, Kaila A; Stephens, Brooke R; Sharoff, Carrie G; Chipkin, Stuart R; Braun, Barry

    2008-10-01

    One bout of exercise enhances insulin-stimulated glucose uptake (insulin action), but the effect is blunted by consumption of carbohydrate-containing food after exercise. The independent roles of energy and carbohydrate in mediating post-exercise insulin action have not been systematically evaluated in humans. The purpose of this study was to determine if varying carbohydrate availability, with energy intake held constant, mediates post-exercise insulin action. Ten young (21 +/- 2 y, overweight (body fat 37% +/- 3%) men and women completed 3 conditions in random order: (i) no-exercise (BASE), (ii) exercise with energy balance but carbohydrate deficit (C-DEF), and (iii) exercise with energy and carbohydrate balance (C-BAL). In the exercise conditions, subjects expended 30% of total daily energy expenditure on a cycle ergometer at 70% VO2 peak. Following exercise, subjects consumed a meal that replaced expended energy (~3000 kJ) and was either balanced (intake = expenditure) or deficient (-100 g) in carbohydrate. Twelve hours later, insulin action was measured by continuous infusion of glucose with stable isotope tracer (CIG-SIT). Changes in insulin action were evaluated using a one-way ANOVA with repeated measures. During CIG-SIT, non-oxidative glucose disposal (i.e., glucose storage) was higher in C-DEF than in BASE (27.2 +/- 3.2 vs. 16.9 +/- 3.5 micromol.L-1.kg-1.min-1, p < 0.05). Conversely, glucose oxidation was lower in C-DEF (8.6 +/- 1.3 micromol.L-1.kg-1.min-1) compared with C-BAL (12.2 +/- 1.2 micromol.L-1.kg-1.min-1), and BASE (17.1 +/- 2.2 micromol.L-1.kg-1.min-1), p < 0.05). Fasting fat oxidation was higher in C-DEF than in BASE (109.8 +/- 10.5 vs. 80.7 +/- 9.6 mg.min-1, p < 0.05). In C-DEF, enhanced insulin action was correlated with the magnitude of the carbohydrate deficit (r = 0.82, p < 0.01). Following exercise, re-feeding expended energy, but not carbohydrate, increased fasting fat oxidation, and shifted insulin-mediated glucose disposal toward

  15. Beyond Synchrony: Joint Action in a Complex Production Task Reveals Beneficial Effects of Decreased Interpersonal Synchrony

    PubMed Central

    Mitkidis, Panagiotis; Roepstorff, Andreas

    2016-01-01

    A variety of joint action studies show that people tend to fall into synchronous behavior with others participating in the same task, and that such synchronization is beneficial, leading to greater rapport, satisfaction, and performance. It has been noted that many of these task environments require simple interactions that involve little planning of action coordination toward a shared goal. The present study utilized a complex joint construction task in which dyads were instructed to build model cars while their hand movements and heart rates were measured. Participants built these models under varying conditions, delimiting how freely they could divide labor during a build session. While hand movement synchrony was sensitive to the different tasks and outcomes, the heart rate measure did not show any effects of interpersonal synchrony. Results for hand movements show that the more participants were constrained by a particular building strategy, the greater their behavioral synchrony. Within the different conditions, the degree of synchrony was predictive of subjective satisfaction and objective product outcomes. However, in contrast to many previous findings, synchrony was negatively associated with superior products, and, depending on the constraints on the interaction, positively or negatively correlated with higher subjective satisfaction. These results show that the task context critically shapes the role of synchronization during joint action, and that in more complex tasks, not synchronization of behavior, but rather complementary types of behavior may be associated with superior task outcomes. PMID:27997558

  16. Effect of dimerization on the mechanism of action of aurein 1.2.

    PubMed

    Lorenzón, E N; Riske, K A; Troiano, G F; Da Hora, G C A; Soares, T A; Cilli, E M

    2016-06-01

    The mechanism of action of antimicrobial peptides depends on physicochemical properties such as structure, concentration, and oligomerization. Here, we focused on the effect of dimerization on the mechanism of action of aurein 1.2 (AU). We designed a lysine-linked AU dimer, (AU)2K, and its interaction with membrane mimetics was studied using four biophysical techniques and molecular dynamics simulations. Circular dichroism and molecular dynamics studies showed that AU displayed a typical spectrum for disordered structures in aqueous solution whereas (AU)2K exhibited the typical spectrum of α-helices in a coiled-coil conformation, wherein helices are wrapped around each other. With the addition of large unilamellar vesicles (LUVs), AU adopted an α-helix structure whereas the coiled-coil structure of (AU)2K assumed an extended conformation. Carboxyfluorescein release experiments with LUVs showed that both peptides were able to permeabilize vesicles although the leakage response to increases in peptide concentration differed. Optical microscopy experiments showed that both peptides induced pore opening and the dimer eventually caused the vesicles to burst. Finally, calorimetric traces determined by isothermal titration calorimetry on the LUVs also showed significant differences in peptide-membrane interactions. Together, the results of our study demonstrated that dimerization changes the mechanism of action of AU.

  17. Gauge coupling field, currents, anomalies and N = 1 super-Yang-Mills effective actions

    NASA Astrophysics Data System (ADS)

    Ambrosetti, Nicola; Arnold, Daniel; Derendinger, Jean-Pierre; Hartong, Jelle

    2017-02-01

    Working with a gauge coupling field in a linear superfield, we construct effective Lagrangians for N = 1 super-Yang-Mills theory fully compatible with the expected all-order behavior or physical quantities. Using the one-loop dependence on its ultraviolet cutoff and anomaly matching or cancellation of R and dilatation anomalies, we obtain the Wilsonian effective Lagrangian. With similar anomaly matching or cancellation methods, we derive the effective action for gaugino condensates, as a function of the real coupling field. Both effective actions lead to a derivation of the NSVZ β function from algebraic arguments only. The extension of results to N = 2 theories or to matter systems is briefly considered. The main tool for the discussion of anomalies is a generic supercurrent structure with 16B +16F operators (the S multiplet), which we derive using superspace identities and field equations for a fully general gauge theory Lagrangian with the linear gauge coupling superfield, and with various U(1)R currents. As a byproduct, we show under which conditions the S multiplet can be improved to contain the Callan-Coleman-Jackiw energy-momentum tensor whose trace measures the breaking of scale invariance.

  18. Mode of action of immunological adjuvants: some physicochemical factors influencing the effectivity of polyacrylic adjuvants.

    PubMed Central

    Kreuter, J; Haenzel, I

    1978-01-01

    The adjuvant effects of different polyacrylic products and monomers were tested. Influenza vaccine was used as a model antigen. Addition of monomers resulted in a decrease in the antibody response, though adjuvant activity of the monomers should be expected according to some theories on adjuvant action. The particle size of the polymer adjuvants proved to be a very important parameter for adjuvant activity. Particles of 0.1 to 0.2 micron yielded a good adjuvant effect, whereas conglomerates or particles bigger than 0.5 micron yielded only poor or no adjuvant effects. The adjuvant effect of 0.1- to 0.2-micron particles was much more reproducible than rat of Al(OH)3. Attention is drawn to the importance of using physiochemically reproducible materials, such as polymer particles, for experimental work. Images PMID:631894

  19. Effect of prostaglandin E1 on certain renal actions of parathyroid hormone

    PubMed Central

    Beck, Nama P.; DeRubertis, Frederick R.; Michelis, Michael F.; Fusco, Robert D.; Field, James B.; Davis, Bernard B.

    1972-01-01

    Parathyroid hormone increased basal adenyl cyclase activity and that increase was inhibited by prostaglandin E1 (PGE1). Tissue cyclic 3′,5′-adenosine monophosphate (cyclic AMP) concentrations were increased by parathyroid hormone and that increase was likewise inhibited by PGE1. Both parathyroid hormone and dibutyryl cyclic AMP increased 32P incorporation into renal cortical phospholipids. PGE1 diminished the effect of parathyroid hormone but not dibutyryl cyclic AMP to influence that parameter. PGE1 likewise modulated the effect of parathyroid hormone but not dibutyryl cyclic AMP to decrease fractional phosphate reabsorption by the renal tubule. It is suggested that PGE1 inhibits the effect of parathyroid hormone by decreasing its effect on adenyl cyclase. Such interaction may be important in modulating the intracellular action of parathyroid hormone on kidney cortex. PMID:4344730

  20. In vitro effect of agriculture pollutants and their joint action on Pseudokirchneriella subcapitata acid phosphatase.

    PubMed

    Jonsson, Claudio Martín; Aoyama, Hiroshi

    2007-10-01

    Acid phosphatase plays important roles in algae metabolism such as availability and recycling of inorganic phosphate, autophagic digestive processes and fertilization. Chemicals released into the environment from agriculture activities may impair algae phosphatase activity. The aim of this work was to evaluate the in vitro effect of twenty-four organic compounds and six metals used as pesticides, or present as contaminants in sewage sludge, on the acid phosphatase activity extracted from Pseudokirchneriella subcapitata. Results demonstrated that only the linear surfactant alkyl benzenesulphonate (LAS) and the heavy metals Hg(2+), Al(3+) and Cu(2+) markedly altered (50%) the enzyme activity. Join action inhibition studies indicated that Hg(2+) was more potent inhibitor than Al(3+) or LAS, and that the Hg(2+)+Al(3+) and Hg(2+)+LAS mixtures have, respectively, additive and slight antagonism effects. Copper, which demonstrated an activator effect when preincubated with the enzyme, behaved as a slight antagonist for the inhibitor effect of Hg(2+).

  1. Effects of lead acetate on guinea pig - cochear microphonics, action potential, and motor nerve conduction velocity

    SciTech Connect

    Yamamura, K.; Maehara, N.; Terayama, K.; Ueno, N.; Kohyama, A.; Sawada, Y.; Kishi, R.

    1987-04-01

    Segmental demyelination and axonal degeneration of motor nerves induced by lead exposure is well known in man, and animals. The effect of lead acetate exposure to man may involve the cranial nerves, since vertigo and sensory neuronal deafness have been reported among lead workers. However, there are few reports concerning the dose-effects of lead acetate both to the peripheral nerve and the cranial VII nerve with measurement of blood lead concentration. The authors investigated the effects of lead acetate to the cochlea and the VIII nerve using CM (cochlear microphonics) and AP (action potential) of the guinea pigs. The effects of lead acetate to the sciatic nerve were measured by MCV of the sciatic nerve with measurement of blood lead concentration.

  2. Effects of menthol on circular smooth muscle of human colon: analysis of the mechanism of action.

    PubMed

    Amato, Antonella; Liotta, Rosa; Mulè, Flavia

    2014-10-05

    Menthol is the major constituent of peppermint oil, an herbal preparation commonly used to treat nausea, spasms during colonoscopy and irritable bowel disease. The mechanism responsible for its spasmolytic action remains unclear. The aims of this study were to investigate the effects induced by menthol on the human distal colon mechanical activity in vitro and to analyze the mechanism of action. The spontaneous or evoked-contractions of the circular smooth muscle were recorded using vertical organ bath. Menthol (0.1 mM-30 mM) reduced, in a concentration-dependent manner, the amplitude of the spontaneous contractions without affecting the frequency and the resting basal tone. The inhibitory effect was not affected by 5-benzyloxytryptamine (1 μM), a transient receptor potential-melastatin8 channel antagonist, or tetrodotoxin (1 μM), a neural blocker, or 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (10 µM), inhibitor of nitric oxide (NO)-sensitive soluble guanylyl cyclase, or tetraethylammonium (10 mM), a blocker of potassium (K+)-channels. On the contrary, nifedipine (3 nM), a voltage-activated L-type Ca2+ channel blocker, significantly reduced the inhibitory menthol actions. Menthol also reduced in a concentration-dependent manner the contractile responses caused by exogenous application of Ca2+ (75-375 μM) in a Ca2+-free solution, or induced by potassium chloride (KCl; 40 mM). Moreover menthol (1-3 mM) strongly reduced the electrical field stimulation (EFS)-evoked atropine-sensitive contractions and the carbachol-contractile responses. The present results suggest that menthol induces spasmolytic effects in human colon circular muscle inhibiting directly the gastrointestinal smooth muscle contractility, through the block of Ca2+ influx through sarcolemma L-type Ca2+ channels.

  3. Mediobasal Hypothalamic SIRT1 Is Essential for Resveratrol’s Effects on Insulin Action in Rats

    PubMed Central

    Knight, Colette M.; Gutierrez-Juarez, Roger; Lam, Tony K.T.; Arrieta-Cruz, Isabel; Huang, Loli; Schwartz, Gary; Barzilai, Nir; Rossetti, Luciano

    2011-01-01

    OBJECTIVE Sirtuin 1 (SIRT1) and its activator resveratrol are emerging as major regulators of metabolic processes. We investigate the site of resveratrol action on glucose metabolism and the contribution of SIRT1 to these effects. Because the arcuate nucleus in the mediobasal hypothalamus (MBH) plays a pivotal role in integrating peripheral metabolic responses to nutrients and hormones, we examined whether the actions of resveratrol are mediated at the MBH. RESEARCH DESIGN AND METHODS Sprague Dawley (SD) male rats received acute central (MBH) or systemic injections of vehicle, resveratrol, or SIRT1 inhibitor during basal pancreatic insulin clamp studies. To delineate the pathway(s) by which MBH resveratrol modulates hepatic glucose production, we silenced hypothalamic SIRT1 expression using a short hairpin RNA (shRNA) inhibited the hypothalamic ATP-sensitive potassium (KATP) channel with glibenclamide, or selectively transected the hepatic branch of the vagus nerve while infusing resveratrol centrally. RESULTS Our studies show that marked improvement in insulin sensitivity can be elicited by acute administration of resveratrol to the MBH or during acute systemic administration. Selective inhibition of hypothalamic SIRT1 using a cell-permeable SIRT1 inhibitor or SIRT1-shRNA negated the effect of central and peripheral resveratrol on glucose production. Blockade of the KATP channel and hepatic vagotomy significantly attenuated the effect of central resveratrol on hepatic glucose production. In addition, we found no evidence for hypothalamic AMPK activation after MBH resveratrol administration. CONCLUSIONS Taken together, these studies demonstrate that resveratrol improves glucose homeostasis mainly through a central SIRT1-dependent pathway and that the MBH is a major site of resveratrol action. PMID:21896928

  4. Therapeutic Effects and Mechanisms of Action of Rifaximin in Gastrointestinal Diseases.

    PubMed

    DuPont, Herbert L

    2015-08-01

    Emerging preclinical and clinic evidence described herein suggests that the mechanism of action of rifaximin is not restricted to direct antibacterial effects within the gastrointestinal tract. Data from this study were derived from general and clinical trial-specific PubMed searches of English-language articles on rifaximin available through December 3, 2014. Search terms included rifaximin alone and in combination (using the Boolean operation "AND") with travelers' diarrhea, hepatic encephalopathy, liver cirrhosis, irritable bowel syndrome, inflammatory bowel disease, and Crohn's disease. Rifaximin appears to reduce bacterial virulence and pathogenicity by inhibiting bacterial translocation across the gastrointestinal epithelial lining. Rifaximin was shown to decrease bacterial adherence to epithelial cells and subsequent internalization in a bacteria- and cell type-specific manner, without an alteration in bacterial counts, but with a down-regulation in epithelial proinflammatory cytokine expression. Rifaximin also appears to modulate gut-immune signaling. In animal models of inflammatory bowel disease, rifaximin produced therapeutic effects by activating the pregnane X receptor and thereby reducing levels of the proinflammatory transcription factor nuclear factor κB. Therefore, for a given disease state, rifaximin may act through several mechanisms of action to exert its therapeutic effects. Clinically, rifaximin 600 mg/d significantly reduced symptoms of travelers' diarrhea (eg, time to last unformed stool vs placebo [32.0 hours vs 65.5 hours, respectively; P=.001]). For the prevention of hepatic encephalopathy recurrence, data indicate that treating 4 patients with rifaximin 1100 mg/d for 6 months would prevent 1 episode of hepatic encephalopathy. For diarrhea-predominant irritable bowel syndrome, a significantly greater percentage (40.7%) of patients treated with rifaximin 1650 mg/d for 2 weeks experienced adequate global irritable bowel syndrome symptom

  5. Effects of rosiglitazone on the configuration of action potentials and ion currents in canine ventricular cells

    PubMed Central

    Szentandrássy, N; Harmati, G; Bárándi, L; Simkó, J; Horváth, B; Magyar, J; Bányász, T; Lőrincz, I; Szebeni, A; Kecskeméti, V; Nánási, PP

    2011-01-01

    BACKGROUND AND PURPOSE In spite of its widespread clinical application, there is little information on the cellular cardiac effects of the antidiabetic drug rosiglitazone in larger experimental animals. In the present study therefore concentration-dependent effects of rosiglitazone on action potential morphology and the underlying ion currents were studied in dog hearts. EXPERIMENTAL APPROACH Standard microelectrode techniques, conventional whole cell patch clamp and action potential voltage clamp techniques were applied in enzymatically dispersed ventricular cells from dog hearts. KEY RESULTS At concentrations ≥10 µM rosiglitazone decreased the amplitude of phase-1 repolarization, reduced the maximum velocity of depolarization and caused depression of the plateau potential. These effects developed rapidly and were readily reversible upon washout. Rosiglitazone suppressed several transmembrane ion currents, concentration-dependently, under conventional voltage clamp conditions and altered their kinetic properties. The EC50 value for this inhibition was 25.2 ± 2.7 µM for the transient outward K+ current (Ito), 72.3 ± 9.3 µM for the rapid delayed rectifier K+ current (IKr) and 82.5 ± 9.4 µM for the L-type Ca2+ current (ICa) with Hill coefficients close to unity. The inward rectifier K+ current (IK1) was not affected by rosiglitazone up to concentrations of 100 µM. Suppression of Ito, IKr, and ICa was confirmed also under action potential voltage clamp conditions. CONCLUSIONS AND IMPLICATIONS Alterations in the densities and kinetic properties of ion currents may carry serious pro-arrhythmic risk in case of overdose with rosiglitazone, especially in patients having multiple cardiovascular risk factors, like elderly diabetic patients. LINKED ARTICLE This article is commented on by Hancox, pp. 496–498 of this issue. To view this commentary visit http://dx.doi.org/10.1111/j.1476-5381.2011.01281.x PMID:21232044

  6. Excitatory actions of GABA in developing chick vestibular afferents: effects on resting electrical activity.

    PubMed

    Cortes, Celso; Galindo, Fabian; Galicia, Salvador; Cebada, Jorge; Flores, Amira

    2013-07-01

    The aim of this study was to characterize the effect of γ-aminobutyric acid (GABA) in the resting multiunit activity of the vestibular afferents during development using the isolated inner ear of embryonic and postnatal chickens (E15-E21 and P5). GABA (10(-3) to 10(-5) M; n = 133) and muscimol (10(-3) M) elicited an increase in the frequency of the basal discharge of the vestibular afferents. We found that GABA action was dose-dependent and inversely related to animal age. Thus, the largest effect was observed in embryonic ages such as E15 and E17 and decreases in E21 and P5. The GABAA receptor antagonists, bicuculline (10(-5) M; n = 10) and picrotoxin (10(-4) M; n = 10), significantly decreased the excitatory action of GABA and muscimol (10(-3) M). Additionally, CNQX 10(-6) M, MCPG 10(-5) M and 7ClKyn 10(-5) M (n = 5) were co-applied by bath substitution (n = 5). Both the basal discharge and the GABA action significantly decreased in these experimental conditions. The chloride channel blocker 9-AC 0.5 mM produced an important reduction in the effect of GABA 10(-3) (n = 5) and 10(-4) M (n = 5). Thus, our results suggest an excitatory role of GABA in the resting activity of the vestibular afferents that can be explained by changes in the gradient of concentration of Cl(-) during development. We show for the first time that the magnitude of this GABA effect decreases at later stages of embryonic and early postnatal development. Taking into account the results with glutamatergic antagonists, we conclude that GABA has a presynaptic action but is not the neurotransmitter in the vestibular afferent synapses, although it could act as a facilitator of the spontaneous activity and may regulate glutamate release.

  7. Three-dimensional noncommutative Yukawa theory: Induced effective action and propagating modes

    NASA Astrophysics Data System (ADS)

    Bufalo, R.; Ghasemkhani, M.

    2017-02-01

    In this paper, we establish the analysis of noncommutative Yukawa theory, encompassing neutral and charged scalar fields. We approach the analysis by considering carefully the derivation of the respective effective actions. Hence, based on the obtained results, we compute the one-loop contributions to the neutral and charged scalar field self-energy, as well as to the Chern-Simons polarization tensor. In order to properly define the behavior of the quantum fields, the known UV/IR mixing due to radiative corrections is analyzed in the one-loop physical dispersion relation of the scalar and gauge fields.

  8. Euler-Lagrange equations for effective actions in QCD and gravity at high energies

    NASA Astrophysics Data System (ADS)

    Lipatov, L. N.

    2017-03-01

    Gluons in QCD and gravitons in quantum gravity lie on the Regge trajectories, which allows to formulate the high-energy scattering in these models in the framework of the reggeon field theory. In particular, the BFKL Pomeron is a composite state of reggeized gluons. In N = 4 SUSY the Pomeron is dual to the reggeized graviton living in the 10-dimensional anti-de-Sitter space. The effective actions for reggeized gluon and graviton interactions are formulated locally in the particle rapidities. The corresponding Euler-Lagrange equations are derived and their simple solutions are constructed.

  9. Action perception predicts action performance

    PubMed Central

    Bailey, Heather R.; Kurby, Christopher A.; Giovannetti, Tania; Zacks, Jeffrey M.

    2013-01-01

    Everyday action impairments often are observed in demented older adults, and they are common potential barriers to functional independence. We evaluated whether the ability to segment and efficiently encode activities is related to the ability to execute activities. Further, we evaluated whether brain regions important for segmentation also were important for action performance. Cognitively healthy older adults and those with very mild or mild dementia of the Alzheimer's type watched and segmented movies of everyday activities and then completed the Naturalistic Action Test. Structural MRI was used to measure volume in the dorsolateral prefrontal cortex (DLPFC), medial temporal lobes (MTL), posterior cortex, and anterior cingulate cortex (ACC). Dementia status and the ability to segment everyday activities strongly predicted naturalistic action performance, and MTL volume largely accounted for this relationship. In addition, the current results supported the Omission-Commission Model: Different cognitive and neurological mechanisms predicted different types of action error. Segmentation, dementia severity, and MTL volume predicted everyday omission errors, DLPFC volume predicted commission errors, and ACC volume predicted action additions. These findings suggest that event segmentation may be critical for effective action production, and that the segmentation and production of activities may recruit the same event representation system. PMID:23851113

  10. Action perception predicts action performance.

    PubMed

    Bailey, Heather R; Kurby, Christopher A; Giovannetti, Tania; Zacks, Jeffrey M

    2013-09-01

    Everyday action impairments often are observed in demented older adults, and they are common potential barriers to functional independence. We evaluated whether the ability to segment and efficiently encode activities is related to the ability to execute activities. Further, we evaluated whether brain regions important for segmentation also were important for action performance. Cognitively healthy older adults and those with very mild or mild dementia of the Alzheimer's type watched and segmented movies of everyday activities and then completed the Naturalistic Action Test. Structural MRI was used to measure volume in the dorsolateral prefrontal cortex (DLPFC), medial temporal lobes (MTL), posterior cortex, and anterior cingulate cortex (ACC). Dementia status and the ability to segment everyday activities strongly predicted naturalistic action performance, and MTL volume largely accounted for this relationship. In addition, the current results supported the Omission-Commission Model: Different cognitive and neurological mechanisms predicted different types of action error. Segmentation, dementia severity, and MTL volume predicted everyday omission errors, DLPFC volume predicted commission errors, and ACC volume predicted action additions. These findings suggest that event segmentation may be critical for effective action production, and that the segmentation and production of activities may recruit the same event representation system.

  11. Effects of pedal type and pull-up action during cycling.

    PubMed

    Mornieux, G; Stapelfeldt, B; Gollhofer, A; Belli, A

    2008-10-01

    The aim of this study was to determine the influence of different shoe-pedal interfaces and of an active pulling-up action during the upstroke phase on the pedalling technique. Eight elite cyclists (C) and seven non-cyclists (NC) performed three different bouts at 90 rev . min (-1) and 60 % of their maximal aerobic power. They pedalled with single pedals (PED), with clipless pedals (CLIP) and with a pedal force feedback (CLIPFBACK) where subjects were asked to pull up on the pedal during the upstroke. There was no significant difference for pedalling effectiveness, net mechanical efficiency (NE) and muscular activity between PED and CLIP. When compared to CLIP, CLIPFBACK resulted in a significant increase in pedalling effectiveness during upstroke (86 % for C and 57 % NC, respectively), as well as higher biceps femoris and tibialis anterior muscle activity (p < 0.001). However, NE was significantly reduced (p < 0.008) with 9 % and 3.3 % reduction for C and NC, respectively. Consequently, shoe-pedal interface (PED vs. CLIP) did not significantly influence cycling technique during submaximal exercise. However, an active pulling-up action on the pedal during upstroke increased the pedalling effectiveness, while reducing net mechanical efficiency.

  12. Effect of drugs modulating serotonergic system on the analgesic action of paracetamol in mice

    PubMed Central

    Karandikar, Yogita S.; Belsare, Peeyush; Panditrao, Aditi

    2016-01-01

    Objective: The underlying mechanisms for the analgesic action of paracetamol (PCT) are still under considerable debate. It has been recently proposed that PCT may act by modulating the Serotonin system. This study was conducted to verify the influence of Serotonin modulating drugs (buspirone, ondansetron, and fluoxetine) on the analgesic effect of PCT. Materials and Methods: Thirty adult albino mice were assigned to five groups: Normal saline, PCT, fluoxetine selective serotonin reuptake inhibitor (SSRI) + PCT, buspirone (5-HT1A Agonist) + PCT, and ondansetron (5HT3 antagonist) + PCT. Hot-plate and formalin test were used to determine pain threshold, tests being conducted 60 min after the last treatment. Statistical analysis was done using analysis of variance followed by Dunnet's test. Results: Coadministration of buspirone with PCT attenuated the antinociceptive activity of PCT (P < 0.001), whereas fluoxetine + PCT increased pain threshold in the hot-plate and formalin test (P = 0.0046). Analgesic effect of PCT was not affected by ondansetron in formalin models. It attenuated analgesic action of PCT in hot-plate test (P = 0.0137). Conclusion: The results suggest that 5-HT1 receptors could also be responsible for the analgesic effect of PCT. Also, higher analgesia is produced by co-administration of SSRI (fluoxetine) + PCT. PMID:27298498

  13. The novel combination of chlorpromazine and pentamidine exerts synergistic antiproliferative effects through dual mitotic action.

    PubMed

    Lee, Margaret S; Johansen, Lisa; Zhang, Yanzhen; Wilson, Amy; Keegan, Mitchell; Avery, William; Elliott, Peter; Borisy, Alexis A; Keith, Curtis T

    2007-12-01

    Combination therapy has proven successful in treating a wide variety of aggressive human cancers. Historically, combination treatments have been discovered through serendipity or lengthy trials using known anticancer agents with similar indications. We have used combination high-throughput screening to discover the unexpected synergistic combination of an antiparasitic agent, pentamidine, and a phenothiazine antipsychotic, chlorpromazine. This combination, CRx-026, inhibits the growth of tumor cell lines in vivo more effectively than either pentamidine or chlorpromazine alone. Here, we report that CRx-026 exerts its antiproliferative effect through synergistic dual mitotic action. Chlorpromazine is a potent and specific inhibitor of the mitotic kinesin KSP/Eg5 and inhibits tumor cell proliferation through mitotic arrest and accumulation of monopolar spindles. Pentamidine treatment results in chromosomal segregation defects and delayed progression through mitosis, consistent with inhibition of the phosphatase of regenerating liver family of phosphatases. We also show that CRx-026 synergizes in vitro and in vivo with the microtubule-binding agents paclitaxel and vinorelbine. These data support a model where dual action of pentamidine and chlorpromazine in mitosis results in synergistic antitumor effects and show the importance of systematic screening for combinations of targeted agents.

  14. OH/A 2 Sigma + - X 2 Pi sub i/ yield from H2O photodissociation in 1050-1370 A

    NASA Technical Reports Server (NTRS)

    Lee, L. C.

    1980-01-01

    The cross section and quantum yield for the production of the OH(A 2 Sigma + - X 2 Pi sub i) emission from H2O photodissociation by synchrotron radiation in the region 1050-1370 A are determined. Measurements of the photoemission and photoabsorption cross sections obtained for incident radiation bandwidths of 2 A reveal different vibrational structures in the range 1250-1370 A, and the photoemission is attributed to the 3a1-4a1 valence and 3a1-3sa1 Rydberg transitions. Photoemission quantum yields determined from the ratio of photoemission to photoabsorption cross sections are found to increase sharply at a threshold of 1362-5 A to a peak of 11% at 1300 A, then to decrease slowly with decreasing wavelength. Implications of the results for the dissociation processes of H2O are considered.

  15. Van der Waals interactions in a monosolvated chiral fluorinated molecule: R2PI vibroelectronic spectra of ( R)-1-phenyl-2,2,2-trifluoroethanol clustered with water

    NASA Astrophysics Data System (ADS)

    Giardini, A.; Rondino, F.; Cattenacci, G.; Paladini, A.; Piccirillo, S.; Satta, M.; Speranza, M.

    2007-02-01

    One colour mass selected resonant two photon ionization R2PI spectra of supersonically expanded ( R)-1-phenyl-2,2,2-trifluoroethanol ( FER) and its complex with water are reported. The excitation spectra are analyzed and discussed on the basis of theoretical predictions at the B3LYP/6-31G ∗∗ level of theory. In the most stable conformer of FER, the OH group establishes an intramolecular hydrogen bond with one of the fluorine atoms of CF 3. In the FER/water complex the formation of a structure in which the water molecule acts as proton acceptor from the OH group and proton donor to the fluorine atom of the CF 3 group is found.

  16. Electronic structure of C-Li, Si-H, and Si-Li in the lowest /sup 4/. sigma. /sup -/ and /sup 2/PI states

    SciTech Connect

    Mavridis, A.; Harrison, J.F.

    1982-05-27

    We have studied the electronic structure of C-Li, Si-Li, and Si-H in the /sup 4/..sigma../sup -/ and /sup 2/pI states using ab initio SCF, MCSCF, and CI techniques. We find that, while Si-H is similar to C-H, having a /sup 2/PI ground state with the /sup 4/..sigma../sup -/ approximately 36 kcal mol/sup -1/ higher, both C-Li and Si-Li have /sup 4/..sigma../sup -/ ground states with the /sup 2/II being 33 and 14 kcal mol/sup -1/ higher, respectively. Potential energy curves and spectroscopic constants are presented for the three title molecules, and some speculation as to the possible consequences of the /sup 4/..sigma../sup -/ ground state of Si-Li and C-Li is indulged in.

  17. 2pi ambiguity-free optical distance measurement with subnanometer precision with a novel phase-crossing low-coherence interferometer.

    PubMed

    Yang, Changhuei; Wax, Adam; Dasari, Ramachandra R; Feld, Michael S

    2002-01-15

    We report a highly accurate phase-based technique for measuring arbitrarily long optical distance with subnanometer precision. The method employs a Michelson interferometer with a pair of harmonically related light sources, one cw and the other low coherence. By slightly detuning (~2 nm) the center wavelength of the low-coherence source between scans of the target sample, we can use the phase relationship between the heterodyne signals of the cw and the low-coherence light to measure the separation between reflecting interfaces with subnanometer precision. As this technique is completely free of 2pi ambiguity, an issue that plagues most phase-based techniques, it can be used to measure arbitrarily long optical distances without loss of precision. We demonstrate one application of this technique, the high-precision determination of the differential refractive index.

  18. Effects of berberine in the gastrointestinal tract - a review of actions and therapeutic implications.

    PubMed

    Chen, Chunqiu; Yu, Zhen; Li, Yongyu; Fichna, Jakub; Storr, Martin

    2014-01-01

    Berberine is an isoquinoline alkaloid present in several plant species, including Coptis sp. and Berberis sp. In traditional medicine, extracts of berberine are used in the treatment of diarrhea of different origins. Recent studies have shown that berberine and its derivatives have significant biological effects on gastrointestinal (GI) and other functions and may become therapeutics for the treatment of diarrhea, gastroenteritis, diabetes, hyperlipidemia, cardiovascular diseases and inflammatory conditions. This paper summarizes the current knowledge on the actions of berberine in the GI tract. Binding and target sites, activated intracellular pathways, as well as the absorption and metabolism of berberine are discussed. Effects that may be useful in future clinical treatment, like antidiarrheal, anti-inflammatory and antitumor effects are critically reviewed and potential clinical applications are presented in detail.

  19. Effect of the 5-HT(6) serotonin antagonist MS-245 on the actions of (-)nicotine.

    PubMed

    Young, Richard; Bondareva, Tatiana; Wesolowska, Anna; Young, Shawquia; Glennon, Richard A

    2006-09-01

    The 5-HT(6) serotonin receptor antagonist MS-245 neither substitutes for nor antagonizes the discriminative stimulus effects of (-)nicotine. However, MS-245 was shown to enhance the potency of (-)nicotine in Sprague-Dawley rats trained to discriminate 0.6 mg/kg of (-)nicotine from saline vehicle in a typical two-lever drug discrimination paradigm such that a combination of MS-245 (5.0 mg/kg) plus the ED(50) dose of (-)nicotine caused the animals to respond as if they had received the training dose of (-)nicotine. MS-245 also potentiated the hypolocomotor actions, but not the antinociceptive effects, of (-)nicotine in mice. The results suggest possible involvement of serotonin-regulated signaling mechanisms in certain behavioral effects of nicotine.

  20. Novel Insights into Lithium's Mechanism of Action: Neurotrophic and Neuroprotective Effects

    PubMed Central

    Quiroz, Jorge A.; Machado-Vieira, Rodrigo; Zarate, Carlos A.; Manji, Husseini K.

    2010-01-01

    The monovalent cation lithium partially exerts its effects by activating neurotrophic and neuroprotective cellular cascades. Here, we discuss the effects of lithium on oxidative stress, programmed cell death (apoptosis), inflammation, glial dysfunction, neurotrophic factor functioning, excitotoxicity, and mitochondrial stability. In particular, we review evidence demonstrating the action of lithium on cyclic adenosine monophosphate (cAMP)-mediated signal transduction, cAMP response element binding activation, increased expression of brain-derived neurotrophic factor, the phosphatidylinositide cascade, protein kinase C inhibition, glycogen synthase kinase 3 inhibition, and B-cell lymphoma 2 expression. Notably, we also review data from clinical studies demonstrating neurotrophic effects of lithium. We expect that a better understanding of the clinically relevant pathophysiological targets of lithium will lead to improved treatments for those who suffer from mood as well as neurodegenerative disorders. PMID:20453535

  1. Novel insights into lithium's mechanism of action: neurotrophic and neuroprotective effects.

    PubMed

    Quiroz, Jorge A; Machado-Vieira, Rodrigo; Zarate, Carlos A; Manji, Husseini K

    2010-01-01

    The monovalent cation lithium partially exerts its effects by activating neurotrophic and neuroprotective cellular cascades. Here, we discuss the effects of lithium on oxidative stress, programmed cell death (apoptosis), inflammation, glial dysfunction, neurotrophic factor functioning, excitotoxicity, and mitochondrial stability. In particular, we review evidence demonstrating the action of lithium on cyclic adenosine monophosphate (cAMP)-mediated signal transduction, cAMP response element binding activation, increased expression of brain-derived neurotrophic factor, the phosphatidylinositide cascade, protein kinase C inhibition, glycogen synthase kinase 3 inhibition, and B-cell lymphoma 2 expression. Notably, we also review data from clinical studies demonstrating neurotrophic effects of lithium. We expect that a better understanding of the clinically relevant pathophysiological targets of lithium will lead to improved treatments for those who suffer from mood as well as neurodegenerative disorders.

  2. Endocrine disrupting chemicals in fish: developing exposure indicators and predictive models of effects based on mechanism of action

    EPA Science Inventory

    Knowledge of possible toxic mechanisms/modes of action (MOA) of chemicals can provide valuable insights as to appropriate methods for assessing exposure and effects, such as reducing uncertainties related to extrapolation across species, endpoints and chemical structure. However,...

  3. The study of combined action of agents using differential geometry of dose-effect surfaces.

    PubMed

    Lam, G K

    1992-09-01

    Although graphic surfaces have been used routinely in the study of combined action of agents, they are mainly used for display purposes. In this paper, it is shown that useful mechanistic information can be obtained from an analytical study of these surfaces using the tools of differential geometry. From the analysis of some simple dose-effect surfaces, it is proposed that the intrinsic curvature, referred to in differential geometry as the Gaussian curvature, of a dose-effect surface can be used as a general criterion for the classification of interaction between different agents. This is analogous to the interpretation of the line curvature of a dose-effect curve as an indication of self-interaction between doses for an agent. In this framework, the dose-effect surface would have basic uniform fabric with zero curvature in the absence of interaction, tentatively referred to as null-interaction. Pictorially speaking, this fabric is distorted locally or globally like the stretching and shrinking of a rubber sheet by the presence of interaction mechanisms between different agents. Since self-interaction with dilution dummies does not generate intrinsic curvature, this criterion of null-interaction would describe the interaction between two truly different agents. It is shown that many of the published interaction mechanisms give rise to dose-effect surfaces with characteristic curvatures. This possible correlation between the intrinsic geometric curvature of dose-effect surfaces and the biophysical mechanism of interaction presents an interesting philosophical viewpoint for the study of combined action of agents.

  4. Update on raloxifene: mechanism of action, clinical efficacy, adverse effects, and contraindications.

    PubMed

    Gizzo, Salvatore; Saccardi, Carlo; Patrelli, Tito Silvio; Berretta, Roberto; Capobianco, Giampiero; Di Gangi, Stefania; Vacilotto, Antonio; Bertocco, Anna; Noventa, Marco; Ancona, Emanuele; D'Antona, Donato; Nardelli, Giovanni Battista

    2013-06-01

    Raloxifene is the only selective estrogen receptor modulator approved for long-term treatment in the prevention of osteoporotic fractures and for the reduction of invasive breast cancer risk in post-menopausal women. The demonstrated beneficial effects on bone and mammalian tissue led clinical and molecular research to focus mainly on these organs, giving less attention to all other systemic effects. The aim of this review was to evaluate all described systemic effects of raloxifene, investigating its molecular and tissutal mechanism of action. A literature research was carried out in electronic databases MEDLINE, EMBASE, ScienceDirect, and the Cochrane Library in interval time between 2000 and 2012. Outcomes were considered in relation to positive/adverse effects concerning bone metabolism, lipid metabolism, coagulation pattern, menopausal symptoms, breast cancer onset, and endometrial cancer onset. Raloxifene acts as an estrogen agonist or antagonist depending on the tissue. This feature is related to specific actions on at least 2 distinct estrogen receptors, whose proportions vary according to tissue type. Raloxifene is a drug for the treatment of osteoporosis and for the prevention of estrogen receptor-positive breast cancer because it guarantees a safety profile on the endometrium. Raloxifene is furthermore an effective therapy in women with increased levels of plasma cholesterol. Raloxifene treatment shifts the coagulation pattern toward prothrombosis, and the patients should be exhaustively informed about the risks associated with therapy. Raloxifene does not show to affect memory and cognition. Finally, it is noteworthy that quality-of-life studies demonstrated some favorable effects of raloxifene.

  5. Dissociating affordance and spatial compatibility effects using a pantomimed reaching action.

    PubMed

    Couth, Samuel; Gowen, Emma; Poliakoff, Ellen

    2014-03-01

    Previous research has demonstrated faster reaction times in response to appropriately oriented action-inducing stimuli (affordance effect, e.g. Tucker and Ellis in J Exp Psychol Hum Percept Perform 24:830-846, 1998). However, it has been argued that faster responses may be due to a spatial compatibility effect. In the current investigation, we aimed to dissociate the affordance and spatial compatibility effects. Moreover, we explored these effects beyond button-press responses by measuring detailed kinematics of the arms and hands during a naturalistic reach response. Participants were presented with images of a door handle (affording) or an abstract (non-affording) stimulus and made a pantomimed reach response with either hand depending on a colour change of the stimulus (i.e. Blue = left, Green = right). Stimuli could be aligned as spatially compatible or incompatible with the responding hand. The colour change occurred after a delay of 0, 500 or 1,000 ms. Only spatially compatible affordance stimuli facilitated reach onset compared to other stimuli and compatibility combinations, replicating previous reaction time studies. Therefore, in the absence of graspable stimuli, spatial compatibility alone was not sufficient to facilitate reach onset. There was also a larger outwards deviation of reach trajectory for spatially incompatible abstract stimuli compared to spatially compatible abstract stimuli, which waned with stimulus onset delay. However, no such affect was observed for the affording stimuli. Accordingly, later kinematics of the reaching action was influenced by the spatial compatibility of the stimulus alone. Overall, the dissociation of affordance and spatial compatibility effects suggests that these effects are driven by visuomotor priming and the inhibition of the incompatible spatial location, respectively.

  6. The effects of rTMS over the primary motor cortex: the link between action and language.

    PubMed

    Repetto, Claudia; Colombo, Barbara; Cipresso, Pietro; Riva, Giuseppe

    2013-01-01

    Is the primary motor cortex (M1) necessary for language comprehension? The present study investigates the role of the primary motor cortex during verbs comprehension, within the framework of the embodied theories of language. We applied rTMS over the right and left hand portion of M1 and tested the effects of the stimulation toward the processing of hand-related action verbs versus abstract verbs. Results underlined a specific inhibition effect following left stimulation, only with hand-related action verbs. These findings seem to corroborate the hypothesis of a functional role of M1 in action verbs comprehension.

  7. Molecular-beam optical Stark and Zeeman study of the A {sup 2}{Pi}--X {sup 2}{Sigma}{sup +} (0,0) band system of BaF

    SciTech Connect

    Steimle, Timothy C.; Frey, Sarah; Le, Anh; DeMille, David; Rahmlow, David A.; Linton, Colan

    2011-07-15

    The A {sup 2}{Pi}-X {sup 2}{Sigma}{sup +} (0,0) band system of barium monofluoride (BaF) has been recorded using high-resolution laser-induced fluorescence spectroscopy both field-free and in the presence of static magnetic and electric fields. The field-free spectra for the {sup 135}BaF, {sup 137}BaF, and {sup 138}BaF isotopologues were modeled to generate an improved set of spectroscopic constants for the A {sup 2}{Pi}({upsilon} = 0) and X {sup 2}{Sigma}{sup +}({upsilon} = 0) states. The observed optical Stark shifts for the {sup 138}BaF isotopologue were analyzed to produce the permanent electric dipole moments of 1.50(2) and 1.31(2) D for the A {sup 2}{Pi}{sub 1/2}({upsilon} = 0) and A {sup 2}{Pi}{sub 3/2} ({upsilon} = 0) states, respectively. The observed optical Zeeman shifts for the {sup 138}BaF isotopologue were analyzed to produce a set of magnetic g factors for the A {sup 2}{Pi}({upsilon} = 0) and X {sup 2}{Sigma}{sup +}({upsilon} = 0) states.

  8. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    USGS Publications Warehouse

    Elskus, Adria A.

    2012-01-01

    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  9. Modelling the differential effects of prisms on perception and action in neglect.

    PubMed

    Leigh, Steven; Danckert, James; Eliasmith, Chris

    2015-03-01

    Damage to the right parietal cortex often leads to a syndrome known as unilateral neglect in which the patient fails to attend or respond to stimuli in left space. Recent work attempting to rehabilitate the disorder has made use of rightward-shifting prisms that displace visual input further rightward. After a brief period of adaptation to prisms, many of the symptoms of neglect show improvements that can last for hours or longer, depending on the adaptation procedure. Recent work has shown, however, that differential effects of prisms can be observed on actions (which are typically improved) and perceptual biases (which often remain unchanged). Here, we present a computational model capable of explaining some basic symptoms of neglect (line bisection behaviour), the effects of prism adaptation in both healthy controls and neglect patients and the observed dissociation between action and perception following prisms. The results of our simulations support recent contentions that prisms primarily influence behaviours normally thought to be controlled by the dorsal stream.

  10. Action-specific effects in a social context: others' abilities influence perceived speed.

    PubMed

    Witt, Jessica K; Sugovic, Mila; Taylor, J Eric T

    2012-06-01

    According to the action-specific account of perception, perceivers see the environment relative to their ability to perform the intended action. For example, in a modified version of the computer game Pong, balls that were easier to block looked to be moving slower than balls that were more difficult to block (Witt & Sugovic, 2010). It is unknown, however, if perception can be influenced by another person's abilities. In the current experiment, we examined whether another person's ability to block a ball influenced the observer's perception of ball speed. Participants played and observed others play the modified version of Pong where the task was to successfully block the ball with paddles that varied in size, and both the actor and observer estimated the speed of the ball. The results showed that both judged the ball to be moving faster when it was harder to block. However, the same effect of difficulty on speed estimates was not found when observers watched a computer play, suggesting the effect is specific to people and not to the task. These studies suggest that the environment can be perceived relative to another person's abilities.

  11. Evaluating noncancer effects of trichloroethylene: dosimetry, mode of action, and risk assessment.

    PubMed Central

    Barton, H A; Clewell, H J

    2000-01-01

    Alternatives for developing chronic exposure limits for noncancer effects of trichloroethylene (TCE) were evaluated. These alternatives were organized within a framework for dose-response assessment--exposure:dosimetry (pharmacokinetics):mode of action (pharmacodynamics): response. This framework provides a consistent structure within which to make scientific judgments about available information, its interpretation, and use. These judgments occur in the selection of critical studies, internal dose metrics, pharmacokinetic models, approaches for interspecies extrapolation of pharmacodynamics, and uncertainty factors. Potentially limiting end points included developmental eye malformations, liver effects, immunotoxicity, and kidney toxicity from oral exposure and neurological, liver, and kidney effects by inhalation. Each end point was evaluated quantitatively using several methods. Default analyses used the traditional no-observed adverse effect level divided by uncertainty factors and the benchmark dose divided by uncertainty factors methods. Subsequently, mode-of-action and pharmacokinetic information were incorporated. Internal dose metrics were estimated using a physiologically based pharmacokinetic (PBPK) model for TCE and its major metabolites. This approach was notably useful with neurological and kidney toxicities. The human PBPK model provided estimates of human exposure doses for the internal dose metrics. Pharmacodynamic data or default assumptions were used for interspecies extrapolation. For liver and neurological effects, humans appear no more sensitive than rodents when internal dose metrics were considered. Therefore, the interspecies uncertainty factor was reduced, illustrating that uncertainty factors are a semiquantitative approach fitting into the organizational framework. Incorporation of pharmacokinetics and pharmacodynamics can result in values that differ significantly from those obtained with the default methods. PMID:10807562

  12. Effects and Mechanism of Action of a Tribulus terrestris Extract on Penile Erection

    PubMed Central

    Do, Jungmo; Choi, Seemin; Choi, Jaehwi

    2013-01-01

    Purpose Tribulus terrestris has been used as an aphrodisiac. However, little is known about the effects and mechanism of action of T. terrestris on penile erection. Therefore, the effect of a T. terrestris extract and the mechanism of action of the extract on relaxation of the corpus cavernosum (CC) were investigated. The erectogenic effects of an oral preparation of the extract were also assessed. Materials and Methods The relaxation effects and mechanism of action of the T. terrestris extract on rabbit CC were investigated in an organ bath. The intracavernous pressure (ICP) was calculated after oral administration of the extract for 1 month to evaluate whether the relaxation response of the CC shown in the organ bath occurred in vivo. Additionally, cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) were measured in the CC by immunoassay. Smooth muscle relaxation was expressed as the percentage decrease in precontraction induced by phenylephrine. The ICP was also assessed in rats after oral administration of the extract for 1 month, and changes in concentrations of cGMP and cAMP were monitored. Results Concentration-dependent relaxation effects of the extract on the CC were detected in the organ bath study. Relaxation of the CC by the T. terrestris extract was inhibited in both an endothelium-removed group and an L-arginen methyl ester pretreatment group. The ICP measured after oral administration of the T. terrestris extract for 1 month was higher than that measured in the control group, and a significant increase in cAMP was observed in the T. terrestris extract group. Conclusions The T. terrestris extract induced concentration-dependent relaxation of the CC in an organ bath. The mechanism included a reaction involving the nitric oxide/nitric oxide synthase pathway and endothelium of the CC. Moreover, in an in vivo study, the T. terrestris extract showed a significant concentration-dependent increase in ICP. Accordingly, the T

  13. The Action-Sentence Compatibility Effect in ASL: the role of semantics vs. perception*

    PubMed Central

    SECORA, KRISTEN; EMMOREY, KAREN

    2015-01-01

    Embodied theories of cognition propose that humans use sensorimotor systems in processing language. The Action-Sentence Compatibility Effect (ACE) refers to the finding that motor responses are facilitated after comprehending sentences that imply movement in the same direction. In sign languages there is a potential conflict between sensorimotor systems and linguistic semantics: movement away from the signer is perceived as motion toward the comprehender. We examined whether perceptual processing of sign movement or verb semantics modulate the ACE. Deaf ASL signers performed a semantic judgment task while viewing signed sentences expressing toward or away motion. We found a significant congruency effect relative to the verb’s semantics rather than to the perceived motion. This result indicates that (a) the motor system is involved in the comprehension of a visual–manual language, and (b) motor simulations for sign language are modulated by verb semantics rather than by the perceived visual motion of the hands. PMID:26052352

  14. Effects of the Positive Action Program on Indicators of Positive Youth Development Among Urban Youth.

    PubMed

    Lewis, Kendra M; Vuchinich, Samuel; Ji, Peter; DuBois, David L; Acock, Alan; Bavarian, Niloofar; Day, Joseph; Silverthorn, Naida; Flay, Brian R

    This study evaluated effects of Positive Action, a school-based social-emotional and character development (SECD) intervention, on indicators of positive youth development (PYD) among a sample of low-income, ethnic minority youth attending 14 urban schools. The study used a matched-pair, cluster-randomized controlled design at the school level. A multiple-measure self-report protocol assessed four key strengths and resources for PYD: self-concept, peer affiliations, ethics, and social skills. Students (n=1170) were assessed from grades 3 to 8, the duration of the intervention, with drop-outs and late entrants included in analyses. Growth curve analyses revealed evidence of favorable program effects on each of the four types of resources. The study contributes to PYD research by providing evidence for school-based interventions in low-income, urban contexts for ethnic minority youth.

  15. Effects of the Positive Action Program on Indicators of Positive Youth Development Among Urban Youth

    PubMed Central

    Lewis, Kendra M.; Vuchinich, Samuel; Ji, Peter; DuBois, David L.; Acock, Alan; Bavarian, Niloofar; Day, Joseph; Silverthorn, Naida; Flay, Brian R.

    2015-01-01

    This study evaluated effects of Positive Action, a school-based social-emotional and character development (SECD) intervention, on indicators of positive youth development (PYD) among a sample of low-income, ethnic minority youth attending 14 urban schools. The study used a matched-pair, cluster-randomized controlled design at the school level. A multiple-measure self-report protocol assessed four key strengths and resources for PYD: self-concept, peer affiliations, ethics, and social skills. Students (n=1170) were assessed from grades 3 to 8, the duration of the intervention, with drop-outs and late entrants included in analyses. Growth curve analyses revealed evidence of favorable program effects on each of the four types of resources. The study contributes to PYD research by providing evidence for school-based interventions in low-income, urban contexts for ethnic minority youth. PMID:26941548

  16. Carbon monoxide effects on human ventricle action potential assessed by mathematical simulations

    PubMed Central

    Trenor, Beatriz; Cardona, Karen; Saiz, Javier; Rajamani, Sridharan; Belardinelli, Luiz; Giles, Wayne R.

    2013-01-01

    Carbon monoxide (CO) that is produced in a number of different mammalian tissues is now known to have significant effects on the cardiovascular system. These include: (i) vasodilation, (ii) changes in heart rate and strength of contractions, and (iii) modulation of autonomic nervous system input to both the primary pacemaker and the working myocardium. Excessive CO in the environment is toxic and can initiate or mediate life threatening cardiac rhythm disturbances. Recent reports link these ventricular arrhythmias to an increase in the slowly inactivating, or “late” component of the Na+ current in the mammalian heart. The main goal of this paper is to explore the basis of this pro-arrhythmic capability of CO by incorporating changes in CO-induced ion channel activity with intracellular signaling pathways in the mammalian heart. To do this, a quite well-documented mathematical model of the action potential and intracellular calcium transient in the human ventricular myocyte has been employed. In silico iterations based on this model provide a useful first step in illustrating the cellular electrophysiological consequences of CO that have been reported from mammalian heart experiments. Specifically, when the Grandi et al. model of the human ventricular action potential is utilized, and after the Na+ and Ca2+ currents in a single myocyte are modified based on the experimental literature, early after-depolarization (EAD) rhythm disturbances appear, and important elements of the underlying causes of these EADs are revealed/illustrated. Our modified mathematical model of the human ventricular action potential also provides a convenient digital platform for designing future experimental work and relating these changes in cellular cardiac electrophysiology to emerging clinical and epidemiological data on CO toxicity. PMID:24146650

  17. Unintended consequences of management actions in salt pond restoration: cascading effects in trophic interactions

    USGS Publications Warehouse

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark; Topping, Brent R.; Shellenbarger, Gregory; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  18. Multi-species occurrence models to evaluate the effects of conservation and management actions

    USGS Publications Warehouse

    Zipkin, E.F.; Andrew, Royle J.; Dawson, D.K.; Bates, S.

    2010-01-01

    Conservation and management actions often have direct and indirect effects on a wide range of species. As such, it is important to evaluate the impacts that such actions may have on both target and non-target species within a region. Understanding how species richness and composition differ as a result of management treatments can help determine potential ecological consequences. Yet it is difficult to estimate richness because traditional sampling approaches detect species at variable rates and some species are never observed. We present a framework for assessing management actions on biodiversity using a multi-species hierarchical model that estimates individual species occurrences, while accounting for imperfect detection of species. Our model incorporates species-specific responses to management treatments and local vegetation characteristics and a hierarchical component that links species at a community-level. This allows for comprehensive inferences on the whole community or on assemblages of interest. Compared to traditional species models, occurrence estimates are improved for all species, even for those that are rarely observed, resulting in more precise estimates of species richness (including species that were unobserved during sampling). We demonstrate the utility of this approach for conservation through an analysis comparing bird communities in two geographically similar study areas: one in which white-tailed deer (Odocoileus virginianus) densities have been regulated through hunting and one in which deer densities have gone unregulated. Although our results indicate that species and assemblage richness were similar in the two study areas, point-level richness was significantly influenced by local vegetation characteristics, a result that would have been underestimated had we not accounted for variability in species detection.

  19. Unintended Consequences of Management Actions in Salt Pond Restoration: Cascading Effects in Trophic Interactions

    PubMed Central

    Takekawa, John Y.; Ackerman, Joshua T.; Brand, L. Arriana; Graham, Tanya R.; Eagles-Smith, Collin A.; Herzog, Mark P.; Topping, Brent R.; Shellenbarger, Gregory G.; Kuwabara, James S.; Mruz, Eric; Piotter, Sara L.; Athearn, Nicole D.

    2015-01-01

    Salt evaporation ponds have played an important role as habitat for migratory waterbirds across the world, however, efforts to restore and manage these habitats to maximize their conservation value has proven to be challenging. For example, salinity reduction has been a goal for restoring and managing former salt evaporation ponds to support waterbirds in the South Bay Salt Pond Restoration Project in San Francisco Bay, California, USA. Here, we describe a case study of unexpected consequences of a low-dissolved oxygen (DO) event on trophic interactions in a salt pond system following management actions to reduce salinity concentrations. We document the ramifications of an anoxic event in water quality including salinity, DO, and temperature, and in the response of the biota including prey fish biomass, numerical response by California Gulls (Larus californicus), and chick survival of Forster's Tern (Sterna forsteri). Management actions intended to protect receiving waters resulted in decreased DO concentrations that collapsed to zero for ≥ 4 consecutive days, resulting in an extensive fish kill. DO depletion likely resulted from an algal bloom that arose following transition of the pond system from high to low salinity as respiration and decomposition outpaced photosynthetic production. We measured a ≥ 6-fold increase in biomass of fish dropped on the levee by foraging avian predators compared with weeks prior to and following the low-DO event. California Gulls rapidly responded to the availability of aerobically-stressed and vulnerable fish and increased in abundance by two orders of magnitude. Mark-recapture analysis of 254 Forster's Tern chicks indicated that their survival declined substantially following the increase in gull abundance. Thus, management actions to reduce salinity concentrations resulted in cascading effects in trophic interactions that serves as a cautionary tale illustrating the importance of understanding the interaction of water quality

  20. Empowering America's Communities to Prepare for the Effects of Climate Change: Developing Actionable Climate Science Under the President's Climate Action Plan

    NASA Astrophysics Data System (ADS)

    Duffy, P. B.; Colohan, P.; Driggers, R.; Herring, D.; Laurier, F.; Petes, L.; Ruffo, S.; Tilmes, C.; Venkataraman, B.; Weaver, C. P.

    2014-12-01

    Effective adaptation to impacts of climate change requires best-available information. To be most useful, this information should be easily found, well-documented, and translated into tools that decision-makers use and trust. To meet these needs, the President's Climate Action Plan includes efforts to develop "actionable climate science". The Climate Data Initiative (CDI) leverages the Federal Government's extensive, open data resources to stimulate innovation and private-sector entrepreneurship in support of actions to prepare for climate change. The Initiative forges commitments and partnerships from the private, NGO, academic, and public sectors to create data-driven tools. Open data from Federal agencies to support this innovation is available on Climate.Data.gov, initially focusing on coastal flooding but soon to expand to topics including food, energy, water, energy, transportation, and health. The Climate Resilience Toolkit (CRT) will facilitate access to data-driven resilience tools, services, and best practices, including those accessible through the CDI. The CRT will also include access to training and tutorials, case studies, engagement forums, and other information sources. The Climate Action Plan also calls for a public-private partnership on extreme weather risk, with the goal of generating improved assessments of risk from different types of extreme weather events, using methods and data that are transparent and accessible. Finally, the U.S. Global Change Research Program and associated agencies work to advance the science necessary to inform decisions and sustain assessments. Collectively, these efforts represent increased emphasis across the Federal Government on the importance of information to support climate resilience.

  1. A naturally occurring naringenin derivative exerts potent bone anabolic effects by mimicking oestrogen action on osteoblasts

    PubMed Central

    Swarnkar, Gaurav; Sharan, Kunal; Siddiqui, Jawed A; Mishra, Jay Sharan; Khan, Kainat; Khan, Mohd Parvez; Gupta, Varsha; Rawat, Preeti; Maurya, Rakesh; Dwivedi, Anil K; Sanyal, Sabyasachi; Chattopadhyay, Naibedya

    2012-01-01

    BACKGROUND AND PURPOSE Naringenin and its derivatives have been assessed in bone health for their oestrogen-‘like’ effects but low bioavailability impedes clinical potential. This study was aimed at finding a potent form of naringenin with osteogenic action. EXPERIMENTAL APPROACH Osteoblast cultures were harvested from mouse calvaria to study differentiation by naringenin, isosakuranetin, poncirin, phloretin and naringenin-6-C-glucoside (NCG). Balb/cByJ ovariectomized (OVx) mice without or with osteopenia were given naringenin, NCG, 17β-oestradiol (E2) or parathyroid hormone (PTH). Efficacy was evaluated by bone microarchitecture using microcomputed tomography and determination of new bone formation by fluorescent labelling of bone. Plasma levels of NCG and naringenin were determined by HPLC. KEY RESULTS NCG stimulated osteoblast differentiation more potently than naringenin, while isosakuranetin, poncirin or phloretin had no effect. NCG had better oral bioavailability than naringenin. NCG increased the mRNA levels of oestrogen receptors (ERs) and bone morphogenetic protein (an ER responsive gene) in vivo, more than naringenin. In OVx mice, NCG treatment in a preventive protocol increased bone formation rate (BFR) and improved trabecular microarchitecture more than naringenin or E2. In osteopenic mice, NCG but not naringenin, in a therapeutic protocol, increased BFR and improved trabecular microarchitecture, comparable with effects of PTH treatment. Stimulatory effects of NCG on osteoblasts were abolished by an ER antagonist. NCG transactivated ERβ but not ERα. NCG exhibited no uterine oestrogenicity unlike naringenin. CONCLUSIONS AND IMPLICATIONS NCG is a potent derivative of naringenin that has bone anabolic action through the activation of osteoblast ERs and exhibited substantial oral bioavailability. PMID:21864313

  2. Differential effects of fluoxetine and venlafaxine on memory recognition: possible mechanisms of action.

    PubMed

    Carlini, Valeria Paola; Poretti, María Belén; Rask-Andersen, Mathias; Chavan, Rohit A; Ponzio, Marina F; Sawant, Rahul S; de Barioglio, Susana Rubiales; Schiöth, Helgi B; de Cuneo, Marta Fiol

    2012-08-07

    Serotonin-specific reuptake inhibitors (SSRI) and serotonin-norepinephrine reuptake inhibitors (SNRI) are antidepressant drugs commonly used to treat a wide spectrum of mood disorders (Wong and Licinio, 2001). Although they have been clinically used for more than 50 years, the molecular and cellular basis for the action of SSRIs and SNRIs is not clear. Considering that the changes in gene expression involved in the action of antidepressant drugs on memory have not been identified, in this study we investigated the impact of chronic treatment with a SSRI (fluoxetine) and a SNRI (venlafaxine) on the mRNA expression of genes related to memory cascade in the mouse hippocampus, namely, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), nitric oxide synthase 1 (NOS1), neurotrophic tyrosine kinase receptor type 2 (TrKB), mitogen-activated protein kinases (MAPK/ERK) and serotonin transporter (SERT). Animals treated with fluoxetine 10 mg/Kg/day for 28 days showed a significant decrease in the percentage of time spent in the novel object recognition test (p≤0.005) and induced MAPK1/ERK2 down-regulation (p=0.005). Our results suggest that the effect on cognition could probably be explained by fluoxetine interference in the MAPK/ERK memory pathway. In contrast, chronic treatment with venlafaxine did not reduce MAPK1/ERK2 expression, suggesting that MAPK1/ERK2 down-regulation is not a common effect of all antidepressant drugs. Further studies are needed to examine the effect of chronic fluoxetine treatment on the ERK-CREB system, and to determine whether there is a causal relationship between the disruption of the ERK-CREB system and the effect of this antidepressant on memory performance.

  3. Effects of norfluoxetine on the action potential and transmembrane ion currents in canine ventricular cardiomyocytes.

    PubMed

    Magyar, János; Szentandrássy, Norbert; Bányász, Tamás; Kecskeméti, Valéria; Nánási, Péter P

    2004-09-01

    Norfluoxetine is the most important active metabolite of the widely used antidepressant compound fluoxetine. Although the cellular electrophysiological actions of fluoxetine are well characterized in cardiac cells, little is known about the effects of its metabolite. In this study, therefore, the effects of norfluoxetine on action potential (AP) configuration and transmembrane ion currents were studied in isolated canine cardiomyocytes using the whole cell configuration of patch clamp techniques. Micromolar concentrations of norfluoxetine (1-10 microM) modified AP configuration: amplitude and duration of the AP and maximum velocity of depolarization were decreased in addition to depression of the plateau and elimination of the incisura of AP. Voltage clamp experiments revealed a concentration-dependent suppression of both L-type Ca(2+) current, I(Ca) (EC(50)=1.13+/-0.08 microM) and transient outward K(+) current, I(to) (EC(50)=1.19+/-0.17 microM) having Hill coefficients close to unity. The midpoint potential of the steady-state inactivation of I(Ca) was shifted from -20.9+/-0.75 mV to -27.7+/-1.35 mV by 3 microM norfluoxetine ( P<0.05, n=7). No such shift in the steady-state inactivation curve was observed in the case of I(to). Similarly, norfluoxetine caused no change in the steady-state current-voltage relationship of the membrane or in the density of the inward rectifier K(+) current, I(K1). All these effects of norfluoxetine developed rapidly and were fully reversible. Comparing present results with those obtained previously with fluoxetine, it can be concluded that norfluoxetine displays stronger suppression of cardiac ion channels than fluoxetine. Consequently, the majority of the cardiac side effects observed during fluoxetine treatment are likely to be attributed to its metabolite norfluoxetine.

  4. The ERP Effects of Combined Cognitive Training on Intention-Based and Stimulus-Based Actions in Older Chinese Adults

    PubMed Central

    Niu, Ya-Nan; Zhu, Xinyi; Li, Juan; Fu, Jiang-Ning

    2016-01-01

    Age-related decreases in action are caused by neuromuscular weakness and cognitive decline. Although physical interventions have been reported to have beneficial effects on cognitive function in older adults, whether cognitive training improves action-related function remains unclear. In this study, we investigated the effects of combined cognitive training on intention-based and stimulus-based actions in older adults using event-related potentials (ERPs). A total of 26 healthy older adults (16 in the training group and 10 in the control group) participated in the study. The training group received 16 sessions of cognitive training, including eight sessions of executive function training and eight sessions of memory strategy training. Before and after training, both groups of participants underwent cognitive assessments and ERP recordings during both the acquisition and test phases with a motor cognitive paradigm. During the acquisition phase, subjects were asked to press one of two keys, either using a self-selected (intention-based) method or based on the preceding stimulus (stimulus-based). During the test phase, subjects were asked to respond to the pre-cues with either congruent or incongruent tasks. Using ERP indices—including readiness potential, P3 and contingent negative variation to identify motor preparation, stimulus processing and interference effect, respectively—we revealed the effects of training on both intention-based and stimulus-based actions. The correlations were also computed between the improved cognitive performance and the ERP amplitudes. It was shown that the improved executive function might extend substantial benefits to both actions, whereas associative memory may be specifically related to the bidirectional action-effect association of intention-based action, although the training effect of memory was absent during the insufficient training hours. In sum, the present study provided empirical evidence demonstrating that action

  5. The ERP Effects of Combined Cognitive Training on Intention-Based and Stimulus-Based Actions in Older Chinese Adults.

    PubMed

    Niu, Ya-Nan; Zhu, Xinyi; Li, Juan; Fu, Jiang-Ning

    2016-01-01

    Age-related decreases in action are caused by neuromuscular weakness and cognitive decline. Although physical interventions have been reported to have beneficial effects on cognitive function in older adults, whether cognitive training improves action-related function remains unclear. In this study, we investigated the effects of combined cognitive training on intention-based and stimulus-based actions in older adults using event-related potentials (ERPs). A total of 26 healthy older adults (16 in the training group and 10 in the control group) participated in the study. The training group received 16 sessions of cognitive training, including eight sessions of executive function training and eight sessions of memory strategy training. Before and after training, both groups of participants underwent cognitive assessments and ERP recordings during both the acquisition and test phases with a motor cognitive paradigm. During the acquisition phase, subjects were asked to press one of two keys, either using a self-selected (intention-based) method or based on the preceding stimulus (stimulus-based). During the test phase, subjects were asked to respond to the pre-cues with either congruent or incongruent tasks. Using ERP indices-including readiness potential, P3 and contingent negative variation to identify motor preparation, stimulus processing and interference effect, respectively-we revealed the effects of training on both intention-based and stimulus-based actions. The correlations were also computed between the improved cognitive performance and the ERP amplitudes. It was shown that the improved executive function might extend substantial benefits to both actions, whereas associative memory may be specifically related to the bidirectional action-effect association of intention-based action, although the training effect of memory was absent during the insufficient training hours. In sum, the present study provided empirical evidence demonstrating that action could

  6. The Cognitive Representation of Intending Not to Act: Evidence for Specific Non-Action-Effect Binding

    ERIC Educational Resources Information Center

    Kuhn, Simone; Brass, Marcel

    2010-01-01

    The question how we represent voluntary action on a cognitive level has recently become of increasing interest to researchers studying motor control. However, so far it has been neglected how we represent the voluntary omission of an action. In our attempt to investigate the representation of voluntary non-actions we demonstrated binding effects…

  7. Action Research in Special Education: An Inquiry Approach for Effective Teaching and Learning. Practitioner Inquiry Series

    ERIC Educational Resources Information Center

    Bruce, Susan M.; Pine, Gerald J.

    2010-01-01

    This is the first book about action research devoted to the complex issues faced by children with disabilities and their teachers. The authors begin by providing the historical and philosophical underpinnings of action research and then present a framework for conducting action research in special education. In addition, they feature four examples…

  8. Effects of the association of antifungal drugs on the antimicrobial action of endodontic sealers.

    PubMed

    Weckwerth, Paulo Henrique; Lima, Fellipe Lombardo de Souza; Greatti, Vanessa Raquel; Duarte, Marco Antonio Hungaro; Vivan, Rodrigo Ricci

    2015-01-01

    This in vitro study aimed to determine the susceptibility of oral specimens and ATCC lineages of Candida albicans for five endodontic sealers, which were pure and associated with two antifungal drugs, and to analyze their effect on the physical properties. For this purpose, 30 lineages of C. albicans, collected from the oral cavity of patients assisted at the endodontics clinic of the Universidade Sagrado Coração, were analyzed. Yeasts susceptibility to the sealers was tested by diffusion on agar plates. Physical properties were evaluated according to the ADA specification no. 57. The pure versions of the Sealer 26, AH Plus, Endofill, Fillapex, and Sealapex demonstrated antifungal activity, with Endofill presenting the greatest inhibition zones. All cements, except for Endofill, had their antifungal actions enhanced by addition of ketoconazole and fluconazole (p < 0.05), and the AH Plus presented the best antifungal activity. The addition of antifungal drugs did not interfere with the setting time and flowability of the sealers. It was concluded that the addition of antifungals to endodontic sealers enhanced the antimicrobial action of most cements tested without altering their physical properties.

  9. Action of boron at the molecular level: effects on transcription and translation in an acellular system.

    PubMed

    Dzondo-Gadet, M; Mayap-Nzietchueng, R; Hess, K; Nabet, P; Belleville, F; Dousset, B

    2002-01-01

    It has been shown that boric acid has well-defined biological effects such as stimulation of wound healing in vivo, release of growth factors and cytokines, and increase of the extracellular matrice turnover. We examined its action at the molecular level, using cell-free systems of transcription (isolated placenta nuclei) and translation (wheat germ extract). We found that 10 mM boric acid greatly increased RNA synthesis, measured by absorbance at 260 nm (x 6.4) or by [3H]-UTP uptake (x 11). Full-length functional mRNA was produced because proteins of 14-80 kDa were translated. Among these proteins, factors involved in angiogenesis and, subsequently, in wound healing (VEGF and TGFbeta) were identified by slot blot, whereas growth factors such as FGF1 and TNFalpha were not detected. These results demonstrate that boron may contribute to biological cell activities at both the transcription and translation levels. However, the mechanism of action is still not known.

  10. The effect of arm action on the vertical jump performance in children and adult females.

    PubMed

    Floría, Pablo; Harrison, Andrew J

    2013-12-01

    The aim of this study was to evaluate the effect of age on the use of arm swing in the vertical jump. Countermovement jumps with arms (CMJA) and without arms (CMJ) performed by 36 girls and 20 adult females were examined using force platform analysis. The data were analyzed to determine differences between groups and between types of jump. The analysis of the data indicated that the arm action increased the jump height in both groups, although the increase was greater in children than adults (22.6% and 18.7% respectively; P < .05). This difference in jump height was due to a combination of a greater increase of the height at take-off in children compared with adults (40.6% and 21.6% respectively; P < .05) with no differences in the increase of the flight height. This increase in height of take-off was accompanied by an increase in the distance of propulsion in CMJA compared with CMJ (0.25 m and 0.23 m respectively; P < .05). The results suggested that children take advantage of the action of the arms in vertical jump differently than adults. The children improved their jump height by increasing height at take-off whereas the adults improved by increasing the flight height.

  11. Differential effects of forward and backward masks on the relationship between perception and action.

    PubMed

    Deplancke, A; Madelain, L; Coello, Y

    2016-03-01

    A recent series of experiments has shown that the effects of near-threshold stimuli on perceptual and motor responses are highly dependent on experimental conditions. In particular, motor influences of near-threshold distractors were observed when using low-contrast unmasked stimuli and high-contrast masked stimuli although only the latter affected motor responses in the absence of stimulus awareness. These results are compatible with neurophysiological models of visual masking, suggesting that early neural responses to a visual stimulus can be decomposed in feedforward activations to-and feedback activations from-higher visual areas, correlating respectively with the actual presence of the stimulus and its conscious perception. We tested the compatibility between these neurophysiological models and the behavioural data obtained in near-threshold experiments. We recorded fast reaching movements directed to a highly visible target followed by a report of the presence of a near-threshold distractor presented either at low contrast without mask or at high contrast with a backward or forward mask. Analysis of hand trajectories revealed that deviations toward the distractor were observed in the no-mask condition when the distractor was present and reported, and when it was present but not reported in the backward and forward mask conditions, although the effect was weaker in the latter condition. These data reveal that the presence or absence of perception-action dissociations in behavioural studies are well accounted for by neurophysiological models of visual masking and that behavioural effects of near-threshold distractors cannot result merely from on a dichotomic visual system for perception and action.

  12. Action at an Attentional Distance: A Study of Children's Reasoning about Causes and Effects Involving Spatial and Attentional Discontinuity

    ERIC Educational Resources Information Center

    Grotzer, Tina A.; Solis, S. Lynneth

    2015-01-01

    Spatial discontinuity between causes and effects is a feature of many scientific concepts, particularly those in the environmental and ecological sciences. Causes can be spatially separated from their effects by great distances. Action at a distance, the idea that causes and effects can be separated in physical space, is a well-studied concept in…

  13. Apoptosis May Explain the Pharmacological Mode of Action and Adverse Effects of Isotretinoin, Including Teratogenicity.

    PubMed

    Melnik, Bodo C

    2017-02-08

    Isotretinoin (13-cis retinoic acid) is the most effective sebum-suppressive drug for the treatment of severe acne. Its effect depends on sebocyte apoptosis, which results from isotretinoin-induced expression of the apoptotic protein tumour necrosis factor-related apoptosis-inducing ligand, insulin-like growth factor-binding protein-3 and neutrophil gelatinase-associated lipocalin. This review proposes that the pharmacological mode of action of isotretinoin in the treatment of severe acne, acute promyelocytic leukaemia, and neuroblastoma results from apoptosis. Furthermore, apoptosis may be the underlying and unifying mechanism of the adverse effects of isotretinoin on neural crest cells (teratogenicity), hippocampal neurones (depression), epidermal keratinocytes and mucosa cells (mucocutaneous side-effects), hair follicle cells (telogen effluvium), intestinal epithelial cells (inflammatory bowel disease), skeletal muscle cells (myalgia and release of creatine kinase), and hepatocytes (release of transaminases and very low-density lipoproteins). Genetic variants of components of the apoptotic signalling cascade, such as RARA polymorphisms, might explain variations in the magnitude of isotretinoin-induced apoptotic signalling and apparently identify subgroups of patients who experience either stronger adverse effects with isotretinoin therapy or resistance to treatment.

  14. Protective action of low-intensity laser radiation relative to the toxic effect of metals (experimental study in vitro)

    NASA Astrophysics Data System (ADS)

    Dejneka, S. Y.

    1997-12-01

    The study of a possible cytotoxic effect of different doses of low-insensitive laser radiation and protective action of low-intensive laser radiation relative to the toxic effect of metals was carried out by means of the alternative method of investigation in vitro on cell cultura Hela. It was established that the investigated doses of low-intensive laser radiation had not produced any toxic effect on cell culture Hela, so the mentioned doses were not cytotoxic. It was revealed that laser radiation reduced the level of the cytotoxic effect of the studied metal salts on the cell culture, and possessed the protective action against the toxic effect of metals. This action has a clear-cut dose- related character.

  15. The effect of animation on learning action symbols by individuals with intellectual disabilities.

    PubMed

    Fujisawa, Kazuko; Inoue, Tomoyoshi; Yamana, Yuko; Hayashi, Humirhiro

    2011-03-01

    The purpose of the present study was to investigate whether participants with intellectual impairments could benefit from the movement associated with animated pictures while they were learning symbol names. Sixteen school students, whose linguistic-developmental age ranged from 38?91 months, participated in the experiment. They were taught 16 static visual symbols and the corresponding action words (naming task) in two sessions conducted one week apart. In the experimental condition, animation was employed to facilitate comprehension, whereas no animation was used in the control condition. Enhancement of learning was shown in the experimental condition, suggesting that the participants benefited from animated symbols. Furthermore, it was found that the lower the linguistic developmental age, the more effective the animated cue was in learning static visual symbols.

  16. Antifungal effect and action mechanism of antimicrobial peptide polybia-CP.

    PubMed

    Wang, Kairong; Jia, Fengjing; Dang, Wen; Zhao, Yanyan; Zhu, Ranran; Sun, Mengyang; Qiu, Shuai; An, Xiaoping; Ma, Zelin; Zhu, Yuanyuan; Yan, Jiexi; Kong, Ziqing; Yan, Wenjin; Wang, Rui

    2016-01-01

    The incidence of life-threatening invasive fungal infections increased significantly in recent years. However, the antifungal therapeutic options are very limited. Antimicrobial peptides are a class of potential lead chemical for the development of novel antifungal agents. Antimicrobial peptide polybia-CP was purified from the venom of the social wasp Polybia paulista. In this study, we synthesized polybia-CP and determined its antifungal effects against a series of Candidian species. Our results showed that polybia-CP has potent antifungal activity and fungicidal activity against the tested fungal cells with a proposed membrane-active action mode. In addition, polybia-CP could induce the increase of cellular reactive oxygen species production, which would attribute to its antifungal activity. In conclusion, the present study suggests that polybia-CP has potential as an antifungal agent or may offer a new strategy for antifungal therapeutic option.

  17. Applications of superspace techniques to effective actions, complex geometry, and T duality in string theory

    NASA Astrophysics Data System (ADS)

    Merrell, Willie Carl, II

    2007-12-01

    We describe the use of superspace techniques to discuss some of the issues in string theory. First we use superspace techniques to derive the effective action for the 10D N = 1 Heterotic string perturbatively to first order in the parameter alpha'. Next we demonstrate how to use the superspace description of the supersymmetric gauge multiplet for chiral superfield in 2d N = (2, 2) to discuss T duality for sigma models that realizes a particular case of generalized Kahler geometry. We find that the salient features of T duality are captured but at the cost of introducing unwanted fields in dual sigma model. Fortunately the extra fields decouple from the relevant fields under consideration. This leads us to introduce a new supersymmetric gauge multiplet that will eliminate the need to introduce extra fields in the dual sigma model.

  18. Nonlinear refractive index measurements and self-action effects in Roselle-Hibiscus Sabdariffa solutions

    NASA Astrophysics Data System (ADS)

    Henari, F. Z.; Al-Saie, A.

    2006-12-01

    We report the observation of self-action phenomena, such as self-focusing, self-defocusing, self-phase modulation and beam fanning in Roselle-Hibiscus Sabdariffa solutions. This material is found to be a new type of natural nonlinear media, and the nonlinear reflective index coefficient has been determined using a Z-scan technique and by measuring the critical power for the self-trapping effect. Z-scan measurements show that this material has a large negative nonlinear refractive index, n 2 = 1 × 10-4 esu. A comparison between the experimental n 2 values and the calculated thermal value for n 2 suggests that the major contribution to nonlinear response is of thermal origin.

  19. Public health in action: effective school health needs renewed international attention.

    PubMed

    Benzian, Habib; Monse, Bella; Belizario, Vicente; Schratz, Alexander; Sahin, Murat; Helderman, Wim van Palenstein

    2012-01-01

    School health programmes as a platform to deliver high-impact health interventions are currently underrated by decision makers and do not get adequate attention from the international public health community. We describe the award-winning Fit for School Approach from the Philippines as an example of a large-scale, integrated, cost-effective and evidence-based programme that bridges the gap between sectors, and between evidence and practice. In view of the challenges to achieve the health and education related Millennium Development Goals (MDGs) in many countries, intensified efforts are required. We present the Fit for School Action Framework as a realistic and tested approach that helps to make schools places of public health for children and wider communities.

  20. Biological effects and mechanisms of action of mesenchymal stem cell therapy in chronic obstructive pulmonary disease.

    PubMed

    Jin, Zhixian; Pan, Xinghua; Zhou, Kaihua; Bi, Hong; Wang, Liyan; Yu, Lu; Wang, Qing

    2015-06-01

    Chronic obstructive pulmonary disease (COPD) is the most frequent chronic respiratory disease and a leading cause of morbidity and mortality, worldwide. Given that the foremost risk factor leading to the development of COPD is cigarette smoke, the initial treatment for COPD is smoking cessation. Even after smoking cessation, inflammation, apoptosis and oxidative stress can persist and continue to contribute to COPD. Although current therapies for COPD (which are primarily based on anti-inflammatory drugs such as corticosteroids, theophylline and bronchodilators) reduce airway obstruction, limit COPD exacerbation and improve the patient's health-related quality-of-life, none can prevent disease progression or reduce mortality. Recent advances in stem cell research have provided novel insight into the potential of bone marrow mesenchymal stem cells (MSCs) in the treatment of several pulmonary diseases. This review article discusses the biological effects and mechanisms of action of MSC transplantation in COPD, and highlights the foundation that MSCs provide for novel therapeutic approaches in COPD.

  1. Action-perception coupling in pianists: learned mappings or spatial musical association of response codes (SMARC) effect?

    PubMed

    Stewart, Lauren; Verdonschot, Rinus G; Nasralla, Patrick; Lanipekun, Jennifer

    2013-01-01

    The principle of common coding suggests that a joint representation is formed when actions are repeatedly paired with a specific perceptual event. Musicians are occupationally specialized with regard to the coupling between actions and their auditory effects. In the present study, we employed a novel paradigm to demonstrate automatic action-effect associations in pianists. Pianists and nonmusicians pressed keys according to aurally presented number sequences. Numbers were presented at pitches that were neutral, congruent, or incongruent with respect to pitches that would normally be produced by such actions. Response time differences were seen between congruent and incongruent sequences in pianists alone. A second experiment was conducted to determine whether these effects could be attributed to the existence of previously documented spatial/pitch compatibility effects. In a "stretched" version of the task, the pitch distance over which the numbers were presented was enlarged to a range that could not be produced by the hand span used in Experiment 1. The finding of a larger response time difference between congruent and incongruent trials in the original, standard, version compared with the stretched version, in pianists, but not in nonmusicians, indicates that the effects obtained are, at least partially, attributable to learned action effects.

  2. Effect of adenosine system in the action of oseltamivir on behavior in mice.

    PubMed

    Uchiyama, Hidemori; Hiromura, Makoto; Shiratani, Tomonori; Kuroki, Hiroaki; Honda, Sinichiro; Kosako, Kazuhiro; Soeda, Shinji; Inoue, Kazuhide; Toda, Akihisa

    2015-07-10

    Abnormal behaviors and death associated with the use of oseltamivir (Tamiflu(®)) have emerged as a major issue in influenza patients. We have previously reported that the mechanisms underlying the effects of caffeine, a non-selective adenosine A1/A2 receptor antagonist, combined with oseltamivir. Oseltamivir is rapidly hydrolyzed to its active form (oseltamivir carboxylate, OCB). In this study, we investigated the effects of an adenosine system and OCB on the action of oseltamivir on mice behavior. Oseltamivir for 1 day (150 mg/kg, intraperitoneally (i.p.)) alone did not affect ambulation at 2 h post-injection. However, caffeine (10 mg/kg, i.p.) in combination with oseltamivir for 1 day increased ambulation. Moreover, caffeine (30 mg/kg, i.p.) in combination with oseltamivir for 3 days increased ambulation, but caffeine (10 mg/kg, i.p.) in combination with oseltamivir for 3 days did not increase. These enhancements were inhibited by an adenosine A2 receptor agonist, CGS21680 (0.2 mg/kg, subcutaneously (s.c.)). Furthermore, an adenosine A2 receptor antagonist, SCH58261 (1 and 3 mg/kg, i.p.) in combination with oseltamivir for 1 day increased ambulation. Moreover, SCH58261 (3 mg/kg, i.p.) in combination with oseltamivir for 3 days increased ambulation, but SCH58261 (1 mg/kg, i.p.) in combination with oseltamivir for 3 days did not. Conversely, in phenobarbital (PB)-treated mice, caffeine (3 mg/kg, i.p.) in combination with oseltamivir for 1 day increased ambulation. Moreover, OCB for 1 day (0.3 μg/mouse intracerebroventricular (i.c.v.)) alone increased ambulation. These findings suggest that the actions of oseltamivir may involve the adenosine systems and its metabolism. Our findings suggest an interaction between the central blockade of adenosine A2 receptors by caffeine and OCB-induced behavioral changes.

  3. Interceptor effect of C60 fullerene on the in vitro action of aromatic drug molecules.

    PubMed

    Skamrova, Galyna B; Laponogov, Ivan; Buchelnikov, Anatoly S; Shckorbatov, Yuriy G; Prylutska, Svitlana V; Ritter, Uwe; Prylutskyy, Yuriy I; Evstigneev, Maxim P

    2014-07-01

    C60 fullerenes are spherical molecules composed purely of carbon atoms. They inspire a particularly strong scientific interest because of their specific physico-chemical properties and potential medical and nanotechnological applications. In this work we are focusing on studying the influence of the pristine C60 fullerene on biological activity of some aromatic drug molecules in human buccal epithelial cells. Assessment of the heterochromatin structure in the cell nucleus as well as the barrier function of the cell membrane was performed. The methods of cell microelectrophoresis and atomic force microscopy were also applied. A concentration-dependent restoration of the functional activity of the cellular nucleus after exposure to DNA-binding drugs (doxorubicin, proflavine and ethidium bromide) has been observed in human buccal epithelial cells upon addition of C60 fullerene at a concentration of ~10(-5 )M. The results were shown to follow the framework of interceptor/protector action theory, assuming that non-covalent complexation between C60 fullerene and the drugs (i.e., hetero-association) is the major process responsible for the observed biological effects. An independent confirmation of this hypothesis was obtained via investigation of the cellular response of buccal epithelium to the coadministration of the aromatic drugs and caffeine, and it is based on the well-established role of hetero-association in drug-caffeine systems. The results indicate that C60 fullerene may reverse the effects caused by the aromatic drugs, thereby pointing out the potential possibility of the use of aromatic drugs in combination with C60 fullerene for regulation of their medico-biological action.

  4. Ecosystem health of the Great Barrier Reef: Time for effective management action based on evidence

    NASA Astrophysics Data System (ADS)

    Brodie, Jon; Pearson, Richard G.

    2016-12-01

    The Great Barrier Reef (GBR) is a World Heritage site off the north-eastern coast of Australia. The GBR is worth A 15-20 billion/year to the Australian economy and provides approximately 64,000 full time jobs. Many of the species and ecosystems of the GBR are in poor condition and continue to decline. The principal causes of the decline are catchment pollutant runoff associated with agricultural and urban land uses, climate change impacts and the effects of fishing. Many important ecosystems of the GBR region are not included inside the boundaries of the World Heritage Area. The current management regime for catchment pollutant runoff and climate change is clearly inadequate to prevent further decline. We propose a refocus of management on a "Greater GBR" (containing not only the major ecosystems and species of the GBR, but also its catchment) and on a set of management actions to halt the decline of the GBR. Proposed actions include: (1) Strengthen management in the areas of the Greater GBR where ecosystems are in good condition, with Torres Strait, northern Cape York and Hervey Bay being the systems with highest current integrity; (2) Investigate methods of cross-boundary management to achieve simultaneous cost-effective terrestrial, freshwater and marine ecosystem protection in the Greater GBR; (3) Develop a detailed, comprehensive, costed water quality management plan for the Greater GBR; (4) Use the Great Barrier Reef Marine Park Act and the Environment Protection and Biodiversity Conservation Act to regulate catchment activities that lead to damage to the Greater GBR, in conjunction with the relevant Queensland legislation; (5) Fund catchment and coastal management to the required level to solve pollution issues for the Greater GBR by 2025, before climate change impacts on Greater GBR ecosystems become overwhelming; (6) Continue enforcement of the zoning plan; (7) Australia to show commitment to protecting the Greater GBR through greenhouse gas emissions

  5. Structual Effects of Cytidine 2^' Ribose Modifications as Determined by Irmpd Action Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hamlow, Lucas; He, Chenchen; Fan, Lin; Wu, Ranran; Yang, Bo; Rodgers, M. T.; Berden, Giel; Oomens, J.

    2015-06-01

    Modified nucleosides, both naturally occurring and synthetic play an important role in understanding and manipulating RNA and DNA. Naturally occurring modified nucleosides are commonly found in functionally important regions of RNA and also affect antibiotic resistance or sensitivity. Synthetic modifications of nucleosides such as fluorinated and arabinosyl nucleosides have found uses as anti-virals and chemotherapy agents. Understanding the effect that modifications have on structure and glycosidic bond stability may lend insight into the functions of these modified nucleosides. Modifications such as the naturally occurring 2^'-O-methylation and the synthetic 2^'-fluorination are believed to help stabilize the nucleoside through the glycosidic bond stability and intramolecular hydrogen bonding. Changing the sugar from ribose to arabinose alters the stereochemistry at the 2^' position and thus shifts the 3D orientation of the 2^'-hydroxyl group, which also affects intramolecular hydrogen bonding and glycosidic bond stability. The structures of 2^'-deoxy-2^'-fluorocytidine, 2^'-O-methylcytidine and cytosine arabinoside are examined in the current work by measuring the infrared spectra in the IR fingerprint region using infrared multiple photon dissociation (IRMPD) action spectroscopy. The structures accessed in the experiments were determined via comparison of the measured IRMPD action spectra to the theoretical linear IR spectra determined by density functional theory and molecular modeling for the stable low-energy structures. Although glycosidic bond stability cannot be quantitatively determined from this data, complementary TCID studies will establish the effect of these modifications. Comparison of these modified nucleosides with their RNA and DNA analogues will help elucidate differences in their intrinsic chemistry.

  6. Just Out of Reach: On the Reliability of the Action-Sentence Compatibility Effect

    PubMed Central

    Papesh, Megan H.

    2015-01-01

    The action-sentence compatibility effect (ACE; Glenberg & Kaschak, 2002), a hallmark finding in Embodied Cognition, implicates the motor system in language comprehension. In the ACE, people process sentences implying movement toward or away from themselves, responding with actions toward or away from their bodies. These processes interact, implying a linkage between linguistic and motor systems. From a theoretical perspective, the ACE has been extremely influential, being widely-cited evidence in favor of embodied cognition. The present study began as an attempt to extend the ACE in a new direction, but eventually became a series of attempts to simply replicate the effect. Across eight experiments, I tested whether the ACE extends to a novel mouse-tracking method and/or is susceptible to higher-order cognitive influences. In three experiments, attempts were made to “disembody” the ACE by presenting participants' names on the computer screen (as in Markman & Brendl, 2005). In each experiment, the ACE could not be disembodied, because the ACE did not occur. In further experiments, the ACE was not observed in reading times, regardless of response mode (mouse movements versus button-presses) or stimuli, including those from the original research. Similarly, no ACE was observed in physical movement times. Bayes Factor analyses of the current experiments, and the previous ACE literature, suggest that the evidence for the ACE is generally weak: Many studies considered as positive evidence actually support the null hypothesis, and very few published results offer strong evidence for the ACE. Implications for the embodiment hypothesis are discussed. PMID:26595844

  7. Effects of covert subject actions on percent body fat by air-displacement plethsymography.

    PubMed

    Tegenkamp, Michelle H; Clark, R Randall; Schoeller, Dale A; Landry, Greg L

    2011-07-01

    Air-displacement plethysmography (ADP) is used for estimation of body composition, however, some individuals, such as athletes in weight classification sports, may use covert methods during ADP testing to alter their apparent percent body fat. The purpose of this study was to examine the effect of covert subject actions on percent body fat measured by ADP. Subjects underwent body composition analysis in the Bod Pod following the standard procedure using the manufacturer's guidelines. The subjects then underwent 8 more measurements while performing the following intentional manipulations: 4 breathing patterns altering lung volume, foot movement to disrupt air, hand cupping to trap air, and heat and cold exposure before entering the chamber. Increasing and decreasing lung volume during thoracic volume measurement and during body density measurement altered the percent body fat assessment (p < 0.001). High lung volume during thoracic gas measures overestimated fat by 3.7 ± 2.1 percentage points. Lowered lung volume during body volume measures overestimated body fat by an additional 2.2 ± 2.1 percentage points. The heat and cold exposure, tapping, and cupping treatments provided similar estimates of percent body fat when compared with the standard condition. These results demonstrate the subjects were able to covertly change their estimated ADP body composition value by altering breathing when compared with the standard condition. We recommend that sports conditioning coaches, athletic trainers, and technicians administering ADP should be aware of the potential effects of these covert actions. The individual responsible for administering ADP should remain vigilant during testing to detect deliberate altered breathing patterns by athletes in an effort to gain a competitive advantage by manipulating their body composition assessment.

  8. Observation of CH A (sup 2)Delta approaches X (sup 2)Pi(sub r) and B (sup 2)Sigma(sup -) approaches X (sup 2)Pi(sub r) emissions in gas-phase collisions of fast O((sup 3)P) atoms with acetylene

    NASA Technical Reports Server (NTRS)

    Orient, O. J.; Chutjian, A.; Murad, E.

    1995-01-01

    Optical emissions in single-collision, beam-beam reactions of fast (3-22 eV translational energy) O(P-3) atoms with C2H2 have been measured in the wavelength range 300-850 nm. Two features were observed, one with a peak wavelength at 431 nm, corresponding to the CH A (sup 2)Delta yields X (sup 2)Pi(sub r) transition, and a second weaker emission in the range 380-400 nm corresponding to the B (sup 2)Sigma(sup -) yields X (sup 2)Pi(sub r) transition. Both the A yields X and B yields X emissions were fit to a synthetic spectrum of CH(A) at a vibrational temperature T(sub v) of 10,000 K (0.86 eV) and a rotational temperature T(r) of approximately 5000 K (0.43 eV); and CH(B) to T(sub v) = 2500 K (0.22 eV) and T(sub r) = 1000 K (0.09 eV). The energy threshold for the A yields X emission was measured to be 7.3 +/- 0.4 eV (lab) or 4.5 +/- 0.2 eV (c.m.). This agrees with the energy threshold of 7.36 eV (lab) for the reaction O(P-3) + C2H2 yields CH(A) + HCO.

  9. 17 CFR 171.41 - Petition for a stay of effective date of a member responsibility action pending a hearing by the...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... effective date of a member responsibility action pending a hearing by the National Futures Association. 171..., REGISTRATION AND MEMBER RESPONSIBILITY ACTIONS Commission Review of Decisions by the National Futures Association In Member Responsibility Actions § 171.41 Petition for a stay of effective date of a...

  10. An electrophysiological study of the object-based correspondence effect: is the effect triggered by an intended grasping action?

    PubMed

    Lien, Mei-Ching; Jardin, Elliott; Proctor, Robert W

    2013-11-01

    We examined Goslin, Dixon, Fischer, Cangelosi, and Ellis's (Psychological Science 23:152-157, 2012) claim that the object-based correspondence effect (i.e., faster keypress responses when the orientation of an object's graspable part corresponds with the response location than when it does not) is the result of object-based attention (vision-action binding). In Experiment 1, participants determined the category of a centrally located object (kitchen utensil vs. tool), as in Goslin et al.'s study. The handle orientation (left vs. right) did or did not correspond with the response location (left vs. right). We found no correspondence effect on the response times (RTs) for either category. The effect was also not evident in the P1 and N1 components of the event-related potentials, which are thought to reflect the allocation of early visual attention. This finding was replicated in Experiment 2 for centrally located objects, even when the object was presented 45 times (33 more times than in Exp. 1). Critically, the correspondence effects on RTs, P1s, and N1s emerged only when the object was presented peripherally, so that the object handle was clearly located to the left or right of fixation. Experiment 3 provided further evidence that the effect was observed only for the base-centered objects, in which the handle was clearly positioned to the left or right of center. These findings contradict those of Goslin et al. and provide no evidence that an intended grasping action modulates visual attention. Instead, the findings support the spatial-coding account of the object-based correspondence effect.

  11. [Farmacological effect of retabolil on aldosterone level and arterial pressure in rats under the action of vibrations].

    PubMed

    Obut, T A; Ovsiukova, M V; Egorova, S A; Érdynieva, T A; Dement'eva, T Iu; Obut, E T

    2014-01-01

    The experiments were performed on male rats, which were subjected to single and multiply repeated vibrations (low-frequency, horizontal, high-amplitude) analogous to the action of motor transport vibrations. It is established that the administration of retabolil produces a hypotensive effect and blocks the vibration-induced increase in the level of hypertensive hormone aldosterone. Under conditions of the multiply repeated action of vibrations, both effects were realized via micro-opioid receptors. In the case of a single action, these receptors were only involved in a hypotensive effect but not mediated in aldosterone suppression. Both these effects were absent in the control group of animals (not subjected to vibrations). Therefore, retabolil can be used as a hypotensive and aldosterone-blocking drug for vibration-induced hypertension in animals and, probably, in humans.

  12. Nongenomic steroid action: Inhibiting effects on cell-to-cell communication between rat ventricular myocytes.

    PubMed

    Verrecchia, F; Sarrouilhe, D; Hervé, J C

    2001-01-01

    Numerous steroids are now believed to possess rapid membrane effects independent of the classical gene activation pathways and are potent modulators of membrane proteins, including voltage-and ligand-operated channels. The effects of steroids on the functional state of the intercellular channels clustered in gap junctions were compared by estimation of either the permeability for a fluorescent dye or the electrical conductance in cardiac myocytes of newborn rat. At 25 muM, the esters of 17beta-estradiol, testosterone and two other androgen hormones rapidly abolished cell-to-cell communication, whereas none of the longer chain steroids, belonging to pregnane (17alpha-hydroxypregnenolone, hydrocortisone), sterol (cholesterol, 25-hydroxycholesterol), bile acid (cholic and lithocholic acids) and vitamin (D3) families, lowered the junctional permeability. Altogether, no correlation with the presence or position of double bonds nor with the trans- or cis-fusion of the A and B rings was recognized. Esterification was a prerequisite for the activity of extracellularly applied steroids but the number, nature and position of ester chain(s) had no influence. 17beta-estradiol or testosterone effects were not prevented when cells were prein-cubated with blockers of the estrogen or androgen nuclear receptors (tamoxifen and cyproterone acetate, respectively). This, together with the rapid time course of the steroid effect (complete within a few minutes), in a rather high active concentration range, suggests a nongenomic mechanism of action. The reversible uncoupling effect of steroids appears to be independent of the shape of the molecules and more probably related to their size and lipo-solubility, which condition their insertion into the lipid bilayer and their subsequent disturbing effects.

  13. Antagonistic effects of fluconazole and 5-fluorocytosine on candidacidal action of amphotericin B in human serum.

    PubMed Central

    Martin, E; Maier, F; Bhakdi, S

    1994-01-01

    This study addressed the effects of fluconazole and 5-fluorocytosine on the candidacidal activity of amphotericin B in the presence of human serum. A Candida albicans isolate that was susceptible to all three agents according to standard testing procedures was employed. Fungicidal activity was estimated by using a flow cytometric procedure that exploited the fact that yeast cells killed by amphotericin B diminish in size and take up propidium iodide. The following findings were made. (i) Fluconazole and 5-fluorocytosine each failed to inhibit pseudohyphal formation and cell aggregation even when applied at 10 and 50 micrograms/ml, respectively, for up to 10 h. Hence, these agents were not fungistatic when tested in the presence of serum. (ii) Simultaneous application of 5-fluorocytosine had neither enhancing nor inhibitory effects on the fungicidal activity of amphotericin B. However, yeasts that were preincubated for 20 h with 5-fluorocytosine became less susceptible to killing by amphotericin B. (iii) Fluconazole exerted a frank antagonistic effect on the fungicidal activity of amphotericin B. Thus, under our in vitro conditions, both fluconazole and 5-fluorocytosine can overtly antagonize the candidacidal action of amphotericin B. PMID:8092834

  14. Effects of goal- and task-oriented motivation in the guilty action test.

    PubMed

    Elaad, Eitan

    2013-04-01

    The present study examined the effectiveness of the Guilty Action Test in detecting critical information from goal-oriented and task-oriented informed innocent examinees. A mock crime procedure was employed and informed innocent participants were either motivated to prove innocence (goal-oriented motivation) or to prove innocence by being cooperative on the test (task-oriented motivation). Half of the participants in each motivation condition were promised course credit reward for successful completion of their mission to prove innocence or to be cooperative (high incentive level). The other half were promised no reward (low incentive level). A fifth group of uninformed innocent participants served for control purposes. Electrodemal, respiration, and cardiovascular measures were used to indicate the motivation effects. Results showed that the combination of goal-oriented instructions and an incentive for success contributed to enhanced responses to the crime-related information. The combination of task-oriented instructions and an incentive for success attenuated these responses. Skin conductance responses were most sensitive to these effects. Theoretical and practical aspects of the results were discussed.

  15. Vasodilatory effects of cinnamaldehyde and its mechanism of action in the rat aorta.

    PubMed

    Xue, Yong-Liang; Shi, Hai-Xia; Murad, Ferid; Bian, Ka

    2011-01-01

    The vasodilatory effect of cinnamaldehyde was investigated for its mechanism of action using isolated rings of rat aorta. Cinnamaldehyde relaxed aortic rings precontracted with phenylephrine in a dose-dependent manner, was not affected by either the presence or removal of the endothelium. Pretreatment with NG-nitro-L-arginine methyl ester and 1H-[1,2,4]-oxadiazole-[4,3-a]-quinoxalin-1-one could not block vasodilation by cinnamaldehyde, indicating that nitric oxide signaling is not involved. Potassium channel blockers, such as glibenclamide, tetraethylammonium, and BaCl2, had no effect on the relaxation produced by cinnamaldehyde. In addition, treatment with either indomethacin or propranolol did not affect cinnamaldehyde-induced vasodilatation. On the other hand, pretreatment of endothelium-denuded rings with cinnamaldehyde significantly inhibited vasoconstriction induced by endogenous vasoconstrictors, including angiotensin II, 5-hydroxytryptamine, dopamine, endothelin-1, and phenylephrine. In a Ca2+-free experimental setting, this natural vasodilator not only blocked Ca2+ influx-dependent vasoconstriction by either phenylephrine or KCl, but also inhibited phenylephrine-induced tonic contraction, which relies on intracellular Ca2+ release. This study shows that endothelium-independent, Ca2+ influx and/or an inhibitory release mechanism contributes to the vasodilatory effect of cinnamaldehyde.

  16. Bioactive effects of quercetin in the central nervous system: Focusing on the mechanisms of actions.

    PubMed

    Suganthy, Natarajan; Devi, Kasi Pandima; Nabavi, Seyed Fazel; Braidy, Nady; Nabavi, Seyed Mohammad

    2016-12-01

    Quercetin, a ubiquitous flavonoid that is widely distributed in plants is classified as a cognitive enhancer in traditional and oriental medicine. The protective effects of quercetin for the treatment of neurodegenerative disorders and cerebrovascular diseases have been demonstrated in both in vitro and in vivo studies. The free radical scavenging activity of quercetin has been well-documented, wherein quercetin has been observed to exhibit protective effects against oxidative stress mediated neuronal damage by modulating the expression of NRF-2 dependent antioxidant responsive elements, and attenuation of neuroinflammation by suppressing NF-κB signal transducer and activator of transcription-1 (STAT-1). Several in vitro and in vivo studies have also shown that quercetin destabilizes and enhances the clearance of abnormal protein such as beta- amyloid peptide and hyperphosphorlyated tau, the key pathological hallmarks of Alzheimer's disease. Quercetin enhances neurogenesis and neuronal longevity by modulating a broad number of kinase signaling cascades such as phophoinositide 3- kinase (P13-kinase), AKT/PKB tyrosine kinase and Protein kinase C (PKC). Quercetin has also been well reported for its ability to reverse cognitive impairment and memory enhancement during aging. The current review focuses on summarizing the recent findings on the neuroprotective effect of quercetin, its mechanism of action and its possible roles in the prevention of neurological disorders.

  17. Anesthetic action on extra-synaptic receptors: effects in neural population models of EEG activity

    PubMed Central

    Hashemi, Meysam; Hutt, Axel; Sleigh, Jamie

    2014-01-01

    The role of extra-synaptic receptors in the regulation of excitation and inhibition in the brain has attracted increasing attention. Because activity in the extra-synaptic receptors plays a role in regulating the level of excitation and inhibition in the brain, they may be important in determining the level of consciousness. This paper reviews briefly the literature on extra-synaptic GABA and NMDA receptors and their affinity to anesthetic drugs. We propose a neural population model that illustrates how the effect of the anesthetic drug propofol on GABAergic extra-synaptic receptors results in changes in neural population activity and the electroencephalogram (EEG). Our results show that increased tonic inhibition in inhibitory cortical neurons cause a dramatic increase in the power of both δ− and α− bands. Conversely, the effects of increased tonic inhibition in cortical excitatory neurons and thalamic relay neurons have the opposite effect and decrease the power in these bands. The increased δ-activity is in accord with observed data for deepening propofol anesthesia; but is absolutely dependent on the inclusion of extrasynaptic (tonic) GABA action in the model. PMID:25540612

  18. Effects of terpineol on the compound action potential of the rat sciatic nerve.

    PubMed

    Moreira, M R; Cruz, G M; Lopes, M S; Albuquerque, A A; Leal-Cardoso, J H

    2001-10-01

    Terpineol, a volatile terpenoid alcohol of low toxicity, is widely used in the perfumery industry. It is an important chemical constituent of the essential oil of many plants with widespread applications in folk medicine and in aromatherapy. The effects of terpineol on the compound action potential (CAP) of rat sciatic nerve were studied. Terpineol induced a dose-dependent blockade of the CAP. At 100 microM, terpineol had no demonstrable effect. At 300 microM terpineol, peak-to-peak amplitude and conduction velocity of CAP were significantly reduced at the end of 180-min exposure of the nerve to the drug, from 3.28 +/- 0.22 mV and 33.5 +/- 7.05 m/s, respectively, to 1.91 +/- 0.51 mV and 26.2 +/- 4.55 m/s. At 600 microM, terpineol significantly reduced peak-to-peak amplitude and conduction velocity from 2.97 +/- 0.55 mV and 32.8 +/- 3.91 m/s to 0.24 +/- 0.23 mV and 2.72 +/- 2.72 m/s, respectively (N = 5). All these effects developed slowly and were reversible upon 180-min washout.

  19. Effect of BML-111 on the intestinal mucosal barrier in sepsis and its mechanism of action.

    PubMed

    Liu, Huaizheng; Liu, Zuoliang; Zhao, Shangping; Sun, Chuanzheng; Yang, Mingshi

    2015-08-01

    5(S),6(R)-7-trihydroxymethyl heptanoate (BML-111) is an lipoxin A4 receptor agonist, which modulates the immune response and attenuates hemorrhagic shock-induced acute lung injury. However, the role of BML-111 in sepsis and in the intestinal mucosal barrier are not well understood. Therefore, the present study was designed to investigate the effect of BML-111 on the intestinal mucosal barrier in a rat model of sepsis. Furthermore, the molecular mechanism of action of BML-111 was evaluated. The cecal ligation and puncture-induced rat model of sepsis was constructed, and BML-111 was administered at three different doses. The results revealed that BML-111 suppressed the elevation of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6, while enhancing the elevation of the anti-inflammatory cytokine transforming growth factor-β in the intestine. In addition, BML-111 significantly upregulated rat defensin-5 mRNA expression levels and downregulated the induction of cell apoptosis as well as caspase-3 activity in the intestine. All these results demonstrated that BML-111 exerted protective effects on the intestinal mucosal barrier in sepsis. Further, it was indicated that alterations in the expression of toll-like receptor (TLR)2 and TLR4 may be one of the molecular mechanisms underlying the protective effect of BML-111. The present study therefore suggested that BML-111 may be a novel therapeutic agent for sepsis.

  20. Vasodilatory effects of cinnamaldehyde and its mechanism of action in the rat aorta

    PubMed Central

    Xue, Yong-Liang; Shi, Hai-Xia; Murad, Ferid; Bian, Ka

    2011-01-01

    The vasodilatory effect of cinnamaldehyde was investigated for its mechanism of action using isolated rings of rat aorta. Cinnamaldehyde relaxed aortic rings precontracted with phenylephrine in a dose-dependent manner, was not affected by either the presence or removal of the endothelium. Pretreatment with NG-nitro-L-arginine methyl ester and 1H-[1,2,4]-oxadiazole-[4,3-a]-quinoxalin-1-one could not block vasodilation by cinnamaldehyde, indicating that nitric oxide signaling is not involved. Potassium channel blockers, such as glibenclamide, tetraethylammonium, and BaCl2, had no effect on the relaxation produced by cinnamaldehyde. In addition, treatment with either indomethacin or propranolol did not affect cinnamaldehyde-induced vasodilatation. On the other hand, pretreatment of endothelium-denuded rings with cinnamaldehyde significantly inhibited vasoconstriction induced by endogenous vasoconstrictors, including angiotensin II, 5-hydroxytryptamine, dopamine, endothelin-1, and phenylephrine. In a Ca2+-free experimental setting, this natural vasodilator not only blocked Ca2+ influx-dependent vasoconstriction by either phenylephrine or KCl, but also inhibited phenylephrine-induced tonic contraction, which relies on intracellular Ca2+ release. This study shows that endothelium-independent, Ca2+ influx and/or an inhibitory release mechanism contributes to the vasodilatory effect of cinnamaldehyde. PMID:21603596

  1. Effects of K(+) channel openers on spontaneous action potentials in detrusor smooth muscle of the guinea-pig urinary bladder.

    PubMed

    Takagi, Hiroaki; Hashitani, Hikaru

    2016-10-15

    The modulation of spontaneous excitability in detrusor smooth muscle (DSM) upon the pharmacological activation of different populations of K(+) channels was investigated. Effects of distinct K(+) channel openers on spontaneous action potentials in DSM of the guinea-pig bladder were examined using intracellular microelectrode techniques. NS1619 (10μM), a large conductance Ca(2+)-activated K(+) (BK) channel opener, transiently increased action potential frequency and then prevented their generation without hyperpolarizing the membrane in a manner sensitive to iberiotoxin (IbTX, 100nM). A higher concentration of NS1619 (30μM) hyperpolarized the membrane and abolished action potential firing. NS309 (10μM) and SKA31 (100μM), small conductance Ca(2+)-activated K(+) (SK) channel openers, dramatically increased the duration of the after-hyperpolarization and then abolished action potential firing in an apamin (100nM)-sensitive manner. Flupirtine (10μM), a Kv7 channel opener, inhibited action potential firing without hyperpolarizing the membrane in a manner sensitive to XE991 (10μM), a Kv7 channel blocker. BRL37344 (10μM), a β3-adrenceptor agonist, or rolipram (10nM), a phosphodiesterase 4 inhibitor, also inhibited action potential firing. A higher concentration of rolipram (100nM) hyperpolarized the DSM and abolished the action potentials. IbTX (100nM) prevented the rolipram-induced blockade of action potentials but not the hyperpolarization. BK and Kv7 channels appear to predominantly contribute to the stabilization of DSM excitability. Spare SK channels could be pharmacologically activated to suppress DSM excitability. BK channels appear to be involved in the cyclic AMP-induced inhibition of action potentials but not the membrane hyperpolarization.

  2. Unexpected events induce motor slowing via a brain mechanism for action-stopping with global suppressive effects.

    PubMed

    Wessel, Jan R; Aron, Adam R

    2013-11-20

    When an unexpected event occurs in everyday life (e.g., a car honking), one experiences a slowing down of ongoing action (e.g., of walking into the street). Motor slowing following unexpected events is a ubiquitous phenomenon, both in laboratory experiments as well as such everyday situations, yet the underlying mechanism is unknown. We hypothesized that unexpected events recruit the same inhibition network in the brain as does complete cancellation of an action (i.e., action-stopping). Using electroencephalography and independent component analysis in humans, we show that a brain signature of successful outright action-stopping also exhibits activity following unexpected events, and more so in blocks with greater motor slowing. Further, using transcranial magnetic stimulation to measure corticospinal excitability, we show that an unexpected event has a global motor suppressive effect, just like outright action-stopping. Thus, unexpected events recruit a common mechanism with outright action-stopping, moreover with global suppressive effects. These findings imply that we can now leverage the considerable extant knowledge of the neural architecture and functional properties of the stopping system to better understand the processing of unexpected events, including perhaps how they induce distraction via global suppression.

  3. Motor imagery in typing: effects of typing style and action familiarity.

    PubMed

    Rieger, Martina

    2012-02-01

    The influences of typing style and action familiarity on executed and imagined typing were investigated. A group of touch typists and a group of hunt-and-peck typists were asked to imagine and execute typing texts of different lengths in two different styles: with ten fingers (familiar for touch typists, unfamiliar for hunt-and-peck typists) and with two fingers (unfamiliar for touch typists, familiar for hunt-and-peck typists). The imagination (but not the execution) of familiar and unfamiliar typing was correlated in both groups, indicating that participants used skill knowledge from the familiar action to imagine the unfamiliar action. Only when touch typists imagined familiar typing accurate motor imagery was observed (similar durations of and positive correlations between imagination and execution). When touch typists imagined unfamiliar typing, the average imagination durations resembled the execution durations, but correlations indicated individual differences in the processes of imagination and execution. Hunt-and-peck typists showed shorter imagination than execution durations with both familiar and unfamiliar typing, indicating that in both styles they did not imagine all details of typing. Also, they did not imagine some details specifically related to unfamiliar typing (reflected in particularly high percentages of absolute error). However, correlations indicated that individual difficulties in executing the unfamiliar action were reflected in the imagination durations. In conclusion, skill knowledge from familiar actions is used to imagine unfamiliar actions. Familiarity with actions promotes accurate motor imagery, but only if stable internal action representations have been acquired, and not if action control relies on online, step-by-step control. However, stable internal action representations of familiar actions may be detrimental for imagery of unfamiliar actions.

  4. Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X)

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter; Laux, Christophe O.

    2004-01-01

    We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

  5. An analysis through order variant Planck's constant over 2pi(2) of a surface hopping expansion of the nonadiabatic wave function.

    PubMed

    Herman, Michael F; Wu, Yinghua

    2008-03-21

    It is shown that a surface hopping expansion of the semiclassical wave function formally satisfies the time independent Schrodinger equation for many-state, multidimensional problems. This wave function includes terms involving hops between different adiabatic quantum states as well as momentum changes without change of state at each point along classical trajectories. The single-state momentum changes correct for the order variant Planck's constant over 2pi(2) errors due to the semiclassical approximation that are present even in single surface problems. A prescription is provided for the direction of this momentum change and the amplitude associated with it. The direction of the momentum change for energy conserving hops between adiabatic states is required to be in the direction of the nonadiabatic coupling vector. The magnitude of the posthop momentum in this direction is determined by the energy, but the sign is not. Hops with both signs of this momentum component are required in order for the wave function to formally satisfy the Schrodinger equation. Numerical results are presented which illustrate how the surface hopping expansion can be implemented and the accuracy that can be obtained.

  6. ASIC1a mediates the drug resistance of human hepatocellular carcinoma via the Ca2+/PI3-kinase/AKT signaling pathway

    PubMed Central

    Zhang, Yihao; Zhang, Ting; Wu, Chao; Xia, Quan; Xu, Dujuan

    2017-01-01

    Chemotherapy is the main treatment method of patients with advanced liver cancer. However, drug resistance is a serious problem in the treatment of hepatocellular carcinoma (HCC). Acid sensing ion channel 1a (ASIC1a) is a H+-gated cation channel; it mediates tumor cell migration and invasion, which suggests that it is involved in the development of malignant tumors. Therefore, we studied the relationship between ASIC1a and drug resistance in human hepatocellular carcinoma. In our study, we found that ASIC1a is highly expressed in human HCC tissue, and that its levels were significantly increased in resistant HCC cells Bel7402/FU and HepG2/ADM. Inhibiting the activity of ASIC1a enhances the chemosensitivity of Bel7402/FU and HepG2/ADM cells. The overexpression of ASIC1a contributed to drug resistance in Bel7402 and HepG2 cells, whereas knockdown of ASIC1a overcame drug resistance in Bel7402/FU and HepG2/ADM cells. We further demonstrated that ASIC1a mediated calcium influx, which resulted in the activation of PI3K/AKT signaling and increased drug resistance. These data suggest that ASIC1a/Ca2+/PI3K/AKT signaling represents a novel pathway that regulates drug resistance, thus offering a potential target for chemotherapy of HCC. PMID:27918554

  7. Search for the OH (X(2)Pi) Meinel band emission in meteors as a tracer of mineral water in comets: detection of N(2)(+) (A-X).

    PubMed

    Jenniskens, Peter; Laux, Christophe O

    2004-01-01

    We report the discovery of the N(2)(+) A-X Meinel band in the 780-840 nm meteor emission from two Leonid meteoroids that were ejected less than 1000 years ago by comet 55P/Tempel-Tuttle. Our analysis indicates that the N(2)(+) molecule is at least an order of magnitude less abundant than expected, possibly as a result of charge transfer reactions with meteoric metal atoms. This new band was found while searching for rovibrational transitions in the X(2)Pi electronic ground state of OH (the OH Meinel band), a potential tracer of water bound to minerals in cometary matter. The electronic A-X transition of OH has been identified in other Leonid meteors. We did not detect this OH Meinel band, which implies that the excited A state is not populated by thermal excitation but by a mechanism that directly produces OH in low vibrational levels of the excited A(2)Sigma state. Ultraviolet dissociation of atmospheric or meteoric water vapor is such a mechanism, as is the possible combustion of meteoric organics.

  8. A discharge flow-photoionization mass spectrometric study of the FO(X 2 Pi i) radical. Photoionization efficiency spectrum and ionization energy

    NASA Technical Reports Server (NTRS)

    Zhang, Zhengyu; Kuo, Szu-Cherng; Klemm, R. Bruce; Monks, Paul S.; Stief, Louis J.

    1994-01-01

    Photoionization efficiency spectra of FO were measured over the wavelength range 80.0-100.0 nm and in the ionization threshold region, 94.0-100.0 nm, using a discharge flow-photoionization mass spectrometer apparatus coupled to a synchrotron radiation source. FO was generated by the reaction of F2P atoms with NO3 and via a F2O2 discharge. A value of 12.78 +/- 0.03 eV was obtained for the adiabatic ionization energy of FO from photoion thresholds which corresponds to FO(+)(X 3 Sigma -) from FO(X 2 Pi i). These results, which are the first to be obtained by direct Photo-ionization mass spectrometry (PIMS) measurements, corroborate those of a photoelectron spectroscopy (PES) study; however, the ionization energy determined here is free from interferences due to other species which complicated the PES measurement. A value of 109.5 +/- 8.0 kJ/mol for Delta f H 0 298(FO) is computed from the present value of IE(FO) and a previous appearance energy measurement, and a value for the proton affinity of FO is calculated to be 511.5 +/- 10.0 kJ/mol.

  9. Effects of 4-aminopyridine on action potentials generation in mouse sinoauricular node strips

    PubMed Central

    Golovko, Vladimir; Gonotkov, Mikhail; Lebedeva, Elena

    2015-01-01

    The physiological role of Ito has yet to be clarified. The goal of this study is to investigate the possible contribution of the transient outward current (Ito) on the generation of transmembrane action potentials (APs) and the sensitivity of mouse sinoauricular node (SAN) cells to a 4-aminopyridine (4AP) as Ito blocker. The electrophysiological identification of cells was performed in the sinoauricular node artery area (nstrips = 38) of the subendocardial surface using microelectrode technique. In this study, for the first time, it was observed that dependence duration of action potential at the level of 20% repolarization (APD20) level under a 4AP concentration in the pacemaker SAN and auricular cells corresponds to a curve predicted by Hill’s equation. APD20 raised by 70% and spike duration of AP increased by 15–25%, when 4AP concentration was increased from 0.1 to 5.0 mmol/L. Auricular cells were found to be more sensitive to 4AP than true pacemaker cells. This was accompanied by a decrease in the upstroke velocity as compared to the control. Our data and previous findings in the literature lead us to hypothesize that the 4AP-sensitive current participates in the repolarization formation of pacemaker and auricular type cells. Thus, study concerning the inhibitory effects of lidocaine and TTX on APD20 can explain the phenomenon of the decrease in upstroke velocity, which, for the first time, was observed after exposure to 4AP. Duration of AP at the level of 20% repolarization (APD20) under a 4-AP concentration 0.5 mmol/L in the true pacemaker cells lengthen by 60–70% with a control. PMID:26156968

  10. Bactericidal Effects and Mechanism of Action of Olanexidine Gluconate, a New Antiseptic

    PubMed Central

    Iwata, Koushi; Nii, Takuya; Nakata, Hikaru; Tsubotani, Yoshie; Inoue, Yasuhide

    2015-01-01

    Olanexidine gluconate [1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate] (development code OPB-2045G) is a new monobiguanide compound with bactericidal activity. In this study, we assessed its spectrum of bactericidal activity and mechanism of action. The minimal bactericidal concentrations of the compound for 30-, 60-, and 180-s exposures were determined with the microdilution method using a neutralizer against 320 bacterial strains from culture collections and clinical isolates. Based on the results, the estimated bactericidal olanexidine concentrations with 180-s exposures were 869 μg/ml for Gram-positive cocci (155 strains), 109 μg/ml for Gram-positive bacilli (29 strains), and 434 μg/ml for Gram-negative bacteria (136 strains). Olanexidine was active against a wide range of bacteria, especially Gram-positive cocci, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, and had a spectrum of bactericidal activity comparable to that of commercial antiseptics, such as chlorhexidine and povidone-iodine. In vitro experiments exploring its mechanism of action indicated that olanexidine (i) interacts with the bacterial surface molecules, such as lipopolysaccharide and lipoteichoic acid, (ii) disrupts the cell membranes of liposomes, which are artificial bacterial membrane models, (iii) enhances the membrane permeability of Escherichia coli, (iv) disrupts the membrane integrity of S. aureus, and (v) denatures proteins at relatively high concentrations (≥160 μg/ml). These results indicate that olanexidine probably binds to the cell membrane, disrupts membrane integrity, and its bacteriostatic and bactericidal effects are caused by irreversible leakage of intracellular components. At relatively high concentrations, olanexidine aggregates cells by denaturing proteins. This mechanism differs slightly from that of a similar biguanide compound, chlorhexidine. PMID:25987609

  11. Effects of bicyclol on dimethylnitrosamine-induced liver fibrosis in mice and its mechanism of action.

    PubMed

    Hu, Qing-Wei; Liu, Geng-Tao

    2006-07-04

    The aim was to investigate the suppressive effect of bicyclol on hepatic fibrosis induced by dimethylnitrosamine (DMN) in mice and the mechanism of its action. Hepatic fibrosis was established by intraperitoneal injection of 8 mg kg(-1) day(-1) on three consecutive days of each week for 4 or 5 weeks. In the prophylactic experiment, bicyclol (100 and 200mg.kg(-1)) was administered by gavage in association with DMN injection. For the therapeutic experiment, mice were firstly injected with DMN for 5 weeks as in the prophylactic experiment, and then the mice in drug groups were orally administered bicyclol (100 and 200mg.kg(-1)) once daily for 5 weeks. As a result, the levels of alanine aminotransferase (ALT), total bilirubin, hydroxyproline (Hyp), prolidase, tumor necrosis factor-alpha (TNFalpha), transforming growth factor beta-1 (TGFbeta(1)), type I collagen in serum and the score of liver fibrosis all significantly increased in the hepatic fibrosis model group in comparison with those in control group. The treatment with bicyclol markedly reduced all the above criteria. Bicyclol also attenuated the decrease of body weight of mice, serum total protein and albumin. In addition, bicyclol treatment inhibited liver TGFbeta(1) and tissue inhibitor of metalloproteinase 1 (TIMP-1) mRNA expression in the prophylactic experiment. Similarly, bicyclol reduced TIMP-1 levels in liver and serum and increased collagenase activity in the liver in the therapeutic experiment. The result suggest that bicyclol attenuates DMN-induced hepatic fibrosis in mice. Its mechanisms of action may be related to the hepatoprotective and anti-inflammation properties, the down-regulation of liver TGFbeta(1) and TIMP-1 expression and the increase of net collagenase activity in liver.

  12. Multinational Corporations and Health Care in the United States and Latin America: Strategies, Actions, and Effects*

    PubMed Central

    JASSO-AGUILAR, REBECA; WAITZKIN, HOWARD; LANDWEHR, ANGELA

    2010-01-01

    In this article we analyze the corporate dominance of health care in the United States and the dynamics that have motivated the international expansion of multinational health care corporations, especially to Latin America. We identify the strategies, actions, and effects of multinational corporations in health care delivery and public health policies. Our methods have included systematic bibliographical research and in-depth interviews in the United States, Mexico, and Brazil. Influenced by public policy makers in the United States, such organizations as the World Bank, International Monetary Fund, and World Trade Organization have advocated policies that encourage reduction and privatization of health care and public health services previously provided in the public sector. Multinational managed care organizations have entered managed care markets in several Latin American countries at the same time as they were withdrawing from managed care activities in Medicaid and Medicare within the United States. Corporate strategies have culminated in a marked expansion of corporations’ access to social security and related public sector funds for the support of privatized health services. International financial institutions and multinational corporations have influenced reforms that, while favorable to corporate interests, have worsened access to needed services and have strained the remaining public sector institutions. A theoretical approach to these problems emphasizes the falling rate of profit as an economic motivation of corporate actions, silent reform, and the subordination of polity to economy. Praxis to address these problems involves opposition to policies that enhance corporate interests while reducing public sector services, as well as alternative models that emphasize a strengthened public sector. PMID:15779471

  13. Multinational corporations and health care in the United States and Latin America: strategies, actions, and effects.

    PubMed

    Jasso-Aguilar, Rebeca; Waitzkin, Howard; Landwehr, Angela

    2004-01-01

    In this article we analyze the corporate dominance of health care in the United States and the dynamics that have motivated the international expansion of multinational health care corporations, especially to Latin America. We identify the strategies, actions, and effects of multinational corporations in health care delivery and public health policies. Our methods have included systematic bibliographical research and in-depth interviews in the United States, Mexico, and Brazil. Influenced by public policy makers in the United States, such organizations as the World Bank, International Monetary Fund, and World Trade Organization have advocated policies that encourage reduction and privatization of health care and public health services previously provided in the public sector. Multinational managed care organizations have entered managed care markets in several Latin American countries at the same time as they were withdrawing from managed care activities in Medicaid and Medicare within the United States. Corporate strategies have culminated in a marked expansion of corporations' access to social security and related public sector funds for the support of privatized health services. International financial institutions and multinational corporations have influenced reforms that, while favorable to corporate interests, have worsened access to needed services and have strained the remaining public sector institutions. A theoretical approach to these problems emphasizes the falling rate of profit as an economic motivation of corporate actions, silent reform, and the subordination of polity to economy. Praxis to address these problems involves opposition to policies that enhance corporate interests while reducing public sector services, as well as alternative models that emphasize a strengthened public sector

  14. H + O3 Fourier-transform infrared emission and laser absorption studies of OH(X2Pi) radical - An experimental dipole moment function and state-to-state Einstein A coefficients

    NASA Technical Reports Server (NTRS)

    Nelson, David D., Jr.; Schiffman, Aram; Nesbitt, David J.; Orlando, John J.; Burkholder, James B.

    1990-01-01

    FTIR emission/absorption spectroscopy is used to measure the relative intensities of 88 pairs of rovibrational transitions of OH(X2Pi) distributed over 16 vibrational bands. The experimental technique used to obtain the Einstein A ratios is discussed. The dipole moment function which follows from the intensity ratios along with Einstein A coefficients calculated from mu(r) is presented.

  15. Theory of laser enhancement and suppression of cold reactions: the fermion-boson 6Li+7Li2<-->(variant Planck's over 2pi omega0) 6Li7Li+7Li radiative collision.

    PubMed

    Li, Xuan; Parker, Gregory A; Brumer, Paul; Thanopulos, Ioannis; Shapiro, Moshe

    2008-03-28

    We present a nonperturbative time-dependent quantum mechanical theory of the laser catalysis and control of a bifurcating A+BC<-->(variant Planck's over 2pi omega(0))ABC*(v)<-->(variant Planck's over 2pi omega(0) )AB+C reaction, with ABC*(v) denoting an intermediate, electronically excited, complex of ABC in the vth vibrational state. We apply this theory to the low collision energy fermion-boson light-induced exchange reaction, (6)Li((2)S)+(7)Li(2)((3)Sigma(u)(+))<-->(variant Planck's over 2pi omega(0))((6)Li(7)Li(7)Li)*<-->(variant Planck's over 2pi omega(0))(6)Li(7)Li((3)Sigma(+))+(7)Li((2)S). We show that at very low collision energies and energetically narrow (approximately 0.01 cm(-1)) initial reactant wave packets, it is possible to tune the yield of the exchange reaction from 0 to near-unity (yield >or=99%) values. Controllability is somewhat reduced at collisions involving energetically wider (approximately 1 cm(-1)) initial reactant wave packets. At these energetic bandwidths, the radiative reactive control, although still impressive, is limited to the 0%-76% reactive-probabilities range.

  16. H + O3 Fourier-transform infrared emission and laser absorption studies of OH(X2Pi) radical - An experimental dipole moment function and state-to-state Einstein A coefficients

    NASA Astrophysics Data System (ADS)

    Nelson, David D., Jr.; Schiffman, Aram; Nesbitt, David J.; Orlando, John J.; Burkholder, James B.

    1990-11-01

    FTIR emission/absorption spectroscopy is used to measure the relative intensities of 88 pairs of rovibrational transitions of OH(X2Pi) distributed over 16 vibrational bands. The experimental technique used to obtain the Einstein A ratios is discussed. The dipole moment function which follows from the intensity ratios along with Einstein A coefficients calculated from mu(r) is presented.

  17. Effects of staggered fermions and mixed actions on the scalar correlator

    SciTech Connect

    Prelovsek, S.

    2006-01-01

    We provide the analytic predictions for the flavor nonsinglet scalar correlator, which will enable determination of the scalar meson mass from the lattice scalar correlator. We consider simulations with 2+1 staggered sea quarks and staggered or chiral valence quarks. At small u/d masses the correlator is dominated by the bubble contribution, which is the intermediate state with two pseudoscalar mesons. We determine the bubble contribution within staggered and mixed chiral perturbation theory. Its effective mass is smaller than the mass of {pi}{eta}, which is the lightest intermediate state in proper 2+1 QCD. The unphysical effective mass is a consequence of the taste breaking that makes possible the intermediate state with mass 2M{sub {pi}}. We find that the scalar correlator can be negative in the simulations with mixed quark actions if the sea- and valence-quark masses are tuned by matching the pion masses M{sub val,val}=M{sub {pi}{sub 5}}.

  18. Keldysh effective action theory for universal physics in spin-(1)/(2) Kondo dots

    NASA Astrophysics Data System (ADS)

    Smirnov, Sergey; Grifoni, Milena

    2013-03-01

    We present a theory for the Kondo spin-(1)/(2) effect in strongly correlated quantum dots. The theory is applicable at any temperature and voltage. It is based on a quadratic Keldysh effective action parametrized by a universal function. We provide a general analytical form for the tunneling density of states through this universal function for which we propose a simple microscopic model. We apply our theory to the highly asymmetric Anderson model with U=∞ and describe its strong-coupling limit, weak-coupling limit, and crossover region within a single analytical expression. We compare our results with a numerical renormalization group in equilibrium and with a real-time renormalization group out of equilibrium and show that the universal shapes of the linear and differential conductance obtained in our theory and in these theories are very close to each other in a wide range of temperatures and voltages. In particular, as in the real-time renormalization group, we predict that at the Kondo voltage the differential conductance is equal to 2/3 of its maximum.

  19. Effects of aminoglycoside antibiotics on calcium action potentials and calcium channel currents.

    PubMed

    Suarez-Kurtz, G

    1989-01-01

    The author reviews work from his laboratory on the effects of neomycin and streptomycin on the Ca(2+)-dependent electrogenesis of crustacean muscle fibers and on two distinct Ca2+ channel currents of pituitary cells. The data indicate that these aminoglycosides inhibit the graded electrogenesis and the action potentials of crustacean muscle; these effects are accompanied by inhibition of tension development upon membrane depolarization. Increasing the extracellular Ca2+ concentration reverses the aminoglycoside-induced blockade of the Ca(2+)-dependent electrogenesis of the muscle fibers. Neomycin blocked both the transient (T-type) and the slowly-inactivating (L-type) Ca2+ currents of clonal pituitary GH3 cells, studied with the whole cell modality of the patch clamp technique. The blockade of these currents was not modulated by activation or inactivation of the channels. Neomycin inhibited also the currents conveyed by Na+ through the slowly-inactivating Ca2+ in cells equilibrated with Ca(2+)-free media. Interpretation of these data led to the suggestion that the blockade of Ca2+ currents by neomycin (and other aminoglycosides) cannot be explained by competition with Ca2+ ions for binding to high affinity transition sites within the Ca2+ channel path.

  20. Designing Effective Natural Hazards Preparedness Communications: Factors that Influence Perceptions and Action

    NASA Astrophysics Data System (ADS)

    Wong-Parodi, G.; Fischhoff, B.

    2012-12-01

    Even though most people believe that natural hazards preparation is important for mitigating damage to their homes and basic survival in the aftermath of a disaster, few actually disaster-proof their homes, create plans, or obtain supplies recommended by agencies such as the Federal Emergency Management Agency. Several observational studies suggest that socio-demographic characteristics such as income and psychological characteristics such as self-efficacy affect whether or not an individual takes action to prepare for a natural hazard. These studies, however, only suggest that these characteristics may play a role. There has been little research that systematically investigates how these characteristics play a role in people's perceptions of recommended preparatory activities and decisions to perform them. Therefore, in Study 1, we explore people's perceptions of natural hazards preparedness measures on four dimensions: time, cost, helpfulness, and sense of preparedness. We further investigate if these responses vary by the socio-demographic and psychological characteristics of self-efficacy, knowledge, and income level. In Study 2, we experimentally test whether people's sense of self-efficacy, as it relates to natural hazards, can be manipulated through exposure to an "easy-and-effective" versus a "hard-and-effective" set of preparation measures. Our findings have implications for the design of natural hazards communication materials for the general public.

  1. Modulatory Effects and Action Mechanisms of Tryptanthrin on Murine Myeloid Leukemia Cells

    PubMed Central

    Chan, Hoi-Ling; Yip, Hon-Yan; Mak, Nai-Ki; Leung, Kwok-Nam

    2009-01-01

    Leukemia is the disorder of hematopoietic cell development and is characterized by an uncoupling of cell proliferation and differentiation. There is a pressing need for the development of novel tactics for leukemia therapy as conventional treatments often have severe adverse side effects. Tryptanthrin (6,12-dihydro-6,12-dioxoindolo-(2,1-b)-quinazoline) is a naturally-occurring, weakly basic alkaloid isolated from the dried roots of medicinal indigo plants (Ban-Lan-Gen). It has been reported to have various biological and pharmacological activities, including anti-microbial, anti-inflammatory, immunomodulatory and anti-tumor effects. However, its modulatory effects and action mechanisms on myeloid cells remain poorly understood. In this study, tryptanthrin was shown to suppress the proliferation of the murine myeloid leukemia WEHI-3B JCS cells in a dose- and time-dependent manner. It also significantly reduced the growth of WEHI-3B JCS cells in vivo in syngeneic BALB/c mice. However, it exhibited no significant direct cytotoxicity on normal murine peritoneal macrophages. Flow cytometric analysis showed an obvious cell cycle arrest of the tryptanthrin-treated WEHI-3B JCS cells at the G0/G1 phase. The expression of cyclin D2, D3, Cdk 2, 4 and 6 genes in WEHI-3B JCS cells was found to be down-regulated at 24 h as measured by RT-PCR. Morphological and functional studies revealed that tryptanthrin could induce differentiation in WEHI-3B JCS cells, as shown by the increases in vacuolation, cellular granularity and NBT-reducing activity in tryptanthrin-treated cells. Collectively, our findings suggest that tryptanthrin might exert its anti-tumor effect on the murine myelomonocytic leukemia WEHI-3B JCS cells by causing cell cycle arrest and by triggering cell differentiation. PMID:19887046

  2. Effect of thermal acclimation on action potentials and sarcolemmal K+ channels from Pacific bluefin tuna cardiomyocytes.

    PubMed

    Galli, G L J; Lipnick, M S; Block, B A

    2009-08-01

    To sustain cardiac muscle contractility relatively independent of temperature, some fish species are capable of temporarily altering excitation-contraction coupling processes to meet the demands of their environment. The Pacific bluefin tuna, Thunnus orientalis, is a partially endothermic fish that inhabits a wide range of thermal niches. The present study examined the effects of temperature and thermal acclimation on sarcolemmal K(+) currents and their role in action potential (AP) generation in bluefin tuna cardiomyocytes. Atrial and ventricular myocytes were enzymatically isolated from cold (14 degrees C)- and warm (24 degrees C)-acclimated bluefin tuna. APs and current-voltage relations of K(+) channels were measured using the whole cell current and voltage clamp techniques, respectively. Data were collected either at the cardiomyocytes' respective acclimation temperature of 14 or 24 degrees C or at a common test temperature of 19 degrees C (to reveal the effects of acclimation). AP duration (APD) was prolonged in cold-acclimated (CA) cardiomyocytes tested at 14 degrees C compared with 19 degrees C and in warm-acclimated (WA) cardiomyocytes tested at 19 degrees C compared with 24 degrees C. This effect was mirrored by a decrease in the density of the delayed-rectifier current (I(Kr)), whereas the density of the background inward-rectifier current (I(K1)) was unchanged. When CA and WA cardiomyocytes were tested at a common temperature of 19 degrees C, no significant effects of temperature acclimation on AP shape or duration were observed, whereas I(Kr) density was markedly increased in CA cardiomyocytes. I(K1) density was unaffected in CA ventricular myocytes but was significantly reduced in CA atrial myocytes, resulting in a depolarization of atrial resting membrane potential. Our results indicate the bluefin AP is relatively short compared with other teleosts, which may allow the bluefin heart to function at cold temperatures without the necessity for thermal

  3. Organising Collective Action for Effective Environmental Management and Social Learning in Wales

    ERIC Educational Resources Information Center

    Mills, Jane; Gibbon, David; Ingram, Julie; Reed, Matt; Short, Christopher; Dwyer, Janet

    2011-01-01

    The paper explored key factors that might lead to successful agri-environmental social learning and collective action in order to deliver landscape-scale resource management within agri-environment schemes. Using the theory of collective action as an analytical framework the paper examined findings from in-depth interviews with 20 members of two…

  4. Action Research an Effective Instructional Leadership Skill for Future Public School Leaders

    ERIC Educational Resources Information Center

    Ringler, Marjorie C.

    2007-01-01

    Learner-centered leadership promotes the facilitation of action research in the classroom as a method of improving teaching and learning. Action research is a classroom research process in which educators study their students' learning related to their own teaching. This process allows teachers to reflect on their own instructional practices and…

  5. The Self in Action Effects: Selective Attenuation of Self-Generated Sounds

    ERIC Educational Resources Information Center

    Weiss, Carmen; Herwig, Arvid; Schutz-Bosbach, Simone

    2011-01-01

    The immediate experience of self-agency, that is, the experience of generating and controlling our actions, is thought to be a key aspect of selfhood. It has been suggested that this experience is intimately linked to internal motor signals associated with the ongoing actions. These signals should lead to an attenuation of the sensory consequences…

  6. Action-Specific Effects in a Social Context: Others' Abilities Influence Perceived Speed

    ERIC Educational Resources Information Center

    Witt, Jessica K.; Sugovic, Mila; Taylor, J. Eric T.

    2012-01-01

    According to the action-specific account of perception, perceivers see the environment relative to their ability to perform the intended action. For example, in a modified version of the computer game Pong, balls that were easier to block looked to be moving slower than balls that were more difficult to block (Witt & Sugovic, 2010). It is unknown,…

  7. Design, Mechanism of Action, Bioavailability and Therapeutic Effects of Mn Porphyrin-based Redox Modulators

    PubMed Central

    Tovmasyan, Artak; Sheng, Huaxin; Weitner, Tin; Arulpragasam, Amanda; Lu, Miaomiao; Warner, David S.; Vujaskovic, Zeljko; Spasojevic, Ivan; Batinic-Haberle, Ines

    2013-01-01

    Based on aqueous redox chemistry and simple in vivo models of oxidative stress, Escherichia coli and Streptomyces cerevisiae, the cationic Mn(III) N-substituted pyridylporphyrins (MnPs) have been identified as the most potent cellular redox modulators within the porphyrin class of drugs; their efficacy in animal models of diseases that have oxidative stress in common, is based on their high ability to catalytically remove superoxide (O2•−), peroxynitrite, carbonate anion radical (CO3•−), hypochlorous acid (HClO), nitric oxide (NO), lipid peroxyl and alkoxyl radicals, thus suppressing the primary oxidative event. While doing so MnPs could couple with cellular reductants and redox-active proteins. Reactive species are widely accepted as regulators of cellular transcriptional activity: minute, nanomolar levels are essential for normal cell function, while submicromolar or micromolar levels impose oxidative stress, which is evidenced in increased inflammatory and immune responses. By removing reactive species, MnPs affect redox-based cellular transcriptional activity and consequently secondary oxidative stress, and in turn inflammatory processes. The equal ability to reduce and oxidize superoxide during the dismutation process and recently accumulated results suggest that pro-oxidative actions of MnPs may also contribute to their therapeutic effects. All our data identify the superoxide dismutase (SOD)-like activity (estimated by log kca(O2•−) as a good measure for the therapeutic efficacy of MnPs. Their accumulation in mitochondria and their ability to cross the blood brain barrier contribute to their remarkable efficacy. We summarize herein the therapeutic effects of MnPs in cancer, central nervous system injuries, diabetes, their radioprotective action and potential for imaging. Few of the most potent modulators of cellular redox-based pathways, MnTE-2-PyP5+, MnTDE-2-ImP5+, MnTnHex-2-PyP5+ and MnTnBuOE-2-PyP5+ are under preclinical and clinical

  8. The effects of ventricular end-diastolic and systolic pressures on action potential and duration in anaesthetized dogs.

    PubMed Central

    Coulshed, D S; Cowan, J C; Drinkhill, M J; Hainsworth, R

    1992-01-01

    1. Although it is known that mechanical events in the heart influence the duration of the cardiac action potential, there is no quantitative information on the effects of independent changes in ventricular end-diastolic and systolic pressures. 2. Experiments were carried out on open-chest anaesthetized dogs in which the autonomic nervous influences on the heart were prevented and monophasic action potentials were recorded form the epicardial surface of the left ventricle. The duration of these action potentials was taken as the interval from the upstroke to the point of 90% repolarization. 3. Elevation of left ventricular peak systolic pressure, at constant end-diastolic pressure, significantly shortened the monophasic action potential. 4. Elevation of end-diastolic pressure at constant peak systolic pressure significantly lengthened the monophasic action potential. 5. Responses were not dependent on release of noradrenaline from sympathetic nerve terminals because they persisted after administration of bretylium tosylate. They were also not due to myocardial ischaemia because they persisted when coronary perfusion pressure was maintained at a constant high level. 6. Simultaneous recordings of changes in myocardial segment length showed the expected responses to changes in ventricular pressures: increases in shortening in response to increases in diastolic pressure and no consistent effect from changes in systolic pressure. 7. These investigations demonstrate the independent effects of changes in systolic and end-diastolic pressures on cardiac action potential duration. This effect is likely to be an effect of the mechanical events, i.e. contraction-excitation feedback. This response may be mediated through changes in myocardial fibre tension, the consequent changes in fibre shortening, or both. PMID:1297849

  9. Evidence for the role of self-priming in epistemic action: expertise and the effective use of memory.

    PubMed

    Maglio, Paul P; Wenger, Michael J; Copeland, Angelina M

    2008-01-01

    Epistemic actions are physical actions people take to simplify internal problem solving rather than to move closer to an external goal. When playing the video game Tetris, for instance, experts routinely rotate falling shapes more than is strictly needed to place the shapes. Maglio and Kirsh [Kirsh, D., & Maglio, P. (1994). On distinguishing epistemic from pragmatic action. Cognitive Science, 18, 513-549; Maglio, P. P. (1995). The computational basis of interactive skill. PhD thesis, University of California, San Diego] proposed that such actions might serve the purpose of priming memory by external means, reducing the need for internal computation (e.g., mental rotation), and resulting in performance improvements that exceed the cost of taking additional actions. The present study tests this priming hypothesis in a set of four experiments. The first three explored precisely the conditions under which priming produces benefits. Results showed that presentation of multiple orientations of a shape led to faster responses than did presentation of a single orientation, and that this effect depended on the interval between preview and test. The fourth explored whether the benefit of seeing shapes in multiple orientations outweighs the cost of taking the extra actions to rotate shapes physically. Benefits were measured using a novel statistical method for mapping reaction-time data onto an estimate of the increase in processing capacity afforded by seeing multiple orientations. Cost was measured using an empirical estimate of time needed to take action in Tetris. Results showed that indeed the increase in internal processing capacity obtained from seeing shapes in multiple orientations outweighed the time to take extra actions.

  10. Mechanisms of action underlying the antiandrogenic effects of the fungicide prochloraz

    SciTech Connect

    Laier, Peter; Metzdorff, Stine Broeng; Borch, Julie; Hagen, Marie Louise; Hass, Ulla; Christiansen, Sofie; Axelstad, Marta; Kledal, Thuri; Dalgaard, Majken; McKinnell, Chris; Brokken, Leon J.S.; Vinggaard, Anne Marie . E-mail: amv@dfvf.dk

    2006-06-01

    The fungicide prochloraz has got multiple mechanisms of action that may influence the demasculinizing and reproductive toxic effects of the compound. In the present study, Wistar rats were dosed perinatally with prochloraz (50 and 150 mg/kg/day) from gestational day (GD) 7 to postnatal day (PND) 16. Caesarian sections were performed on selected dams at GD 21, while others were allowed to give birth to pups that were followed until PND 16. Prochloraz caused mild dysgenesis of the male external genitalia as well as reduced anogenital distance and retention of nipples in male pups. An increased anogenital distance indicated virilization of female pups. Effects on steroidogenesis in male fetuses became evident as decreased testicular and plasma levels of testosterone and increased levels of progesterone. Ex vivo synthesis of both steroid hormones was qualitatively similarly affected by prochloraz. Immunohistochemistry of fetal testes showed increased expression of 17{alpha}-hydroxylase/17,20-lyase (P450c17) and a reduction in 17{beta}-hydroxysteroid dehydrogenase (type 10) expression, whereas no changes in expression of genes involved in testicular steroidogenesis were observed. Increased expression of P450c17 mRNA was observed in fetal male adrenals, and the androgen-regulated genes ornithine decarboxylase, prostatic binding protein C3 as well as insulin-like growth factor I mRNA were reduced in ventral prostates PND 16. These results indicate that reduced activity of P450c17 may be a primary cause of the disrupted fetal steroidogenesis and that an altered androgen metabolism may play a role as well. In vitro studies on human adrenocortical carcinoma cells supported the findings in vivo as reduced testosterone and increased progesterone levels were observed. Overall, these results together indicate that prochloraz acts directly on the fetal testis to inhibit steroidogenesis and that this effect is exhibited at protein, and not at genomic, level.

  11. Antitumor effects of the partially purified polysaccharides from Antrodia camphorata and the mechanism of its action

    SciTech Connect

    Liu, J.-J.; Huang, T.-S.; Hsu, M.-L.; Chen, C.-C.; Lin, W.-S.; Lu, F.-J. . E-mail: fjlu@csmu.edu.tw; Chang, W.-H. . E-mail: whchang@csmu.edu.tw

    2004-12-01

    Antrodia camphorata is a popular folk medicine that has attracted great attention due to its fame for antitumor activity against cancer. However, there is little information available about its action. In the present study, we purified a unique polysaccharide component from A. camphorata mycelia (AC-PS) and found that it has pronounced anti-tumor effects on both in vitro and in vivo model. Our results showed that AC-PS alone did not show any direct cytotoxic effect to human leukemic U937 cells, even at high concentration (200 {mu}g/ml). However, it could inhibit the proliferation of U937 cells via activation of mononuclear cells (MNCs). Treatment of U937 cells with AC-PS-stimulated-MNC-CM could significantly inhibit its proliferation with 55.3% growth inhibition rate. The in vitro antitumor activity was substantiated by the in vivo therapeutical study of AC-PS in sarcoma 180-bearing mice. Intraperitoneal and oral administration of AC-PS, 100 and 200 mg/kg significantly suppressed the tumor growth with the inhibition rate of 69.1% and 58.8%, respectively. In vivo studies also showed that several immunoparameters, such as the spontaneous proliferation of spleen cells, after AC-PS administration, were two-fold higher than in control mice. Furthermore, the cytolytic activity of spleen cells also increased from 9.8 {+-} 1.1% in control mice to 34.2 {+-} 5.5% and 48.2 {+-} 2.5%, after oral and intraperitoneal treatment, respectively. Besides, the mice serum interleukin-12 levels increased significantly by AC-PS treatment. Considering all these results, it is suggested that AC-PS elicit its anti-tumor effect by promoting a Th1-dominant state and killer activities.

  12. Bulk Surfaces Coated with Triangular Silver Nanoplates: Antibacterial Action Based on Silver Release and Photo-Thermal Effect

    PubMed Central

    D’Agostino, Agnese; Taglietti, Angelo; Desando, Roberto; Bini, Marcella; Patrini, Maddalena; Dacarro, Giacomo; Cucca, Lucia; Pallavicini, Piersandro; Grisoli, Pietro

    2017-01-01

    A layer of silver nanoplates, specifically synthesized with the desired localized surface plasmon resonance (LSPR) features, was grafted on amino-functionalized bulk glass surfaces to impart a double antibacterial action: (i) the well-known, long-term antibacterial effect based on the release of Ag+; (ii) an “on demand” action which can be switched on by the use of photo-thermal properties of silver nano-objects. Irradiation of these samples with a laser having a wavelength falling into the so called “therapeutic window” of the near infrared region allows the reinforcement, in the timescale of minutes, of the classical antibacterial effect of silver nanoparticles. We demonstrate how using the two actions allows for almost complete elimination of the population of two bacterial strains of representative Gram-positive and Gram-negative bacteria. PMID:28336841

  13. Feature-Specific Event-Related Potential Effects to Action- and Sound-Related Verbs during Visual Word Recognition

    PubMed Central

    Popp, Margot; Trumpp, Natalie M.; Kiefer, Markus

    2016-01-01

    Grounded cognition theories suggest that conceptual representations essentially depend on modality-specific sensory and motor systems. Feature-specific brain activation across different feature types such as action or audition has been intensively investigated in nouns, while feature-specific conceptual category differences in verbs mainly focused on body part specific effects. The present work aimed at assessing whether feature-specific event-related potential (ERP) differences between action and sound concepts, as previously observed in nouns, can also be found within the word class of verbs. In Experiment 1, participants were visually presented with carefully matched sound and action verbs within a lexical decision task, which provides implicit access to word meaning and minimizes strategic access to semantic word features. Experiment 2 tested whether pre-activating the verb concept in a context phase, in which the verb is presented with a related context noun, modulates subsequent feature-specific action vs. sound verb processing within the lexical decision task. In Experiment 1, ERP analyses revealed a differential ERP polarity pattern for action and sound verbs at parietal and central electrodes similar to previous results in nouns. Pre-activation of the meaning of verbs in the preceding context phase in Experiment 2 resulted in a polarity-reversal of feature-specific ERP effects in the lexical decision task compared with Experiment 1. This parallels analogous earlier findings for primed action and sound related nouns. In line with grounded cognitions theories, our ERP study provides evidence for a differential processing of action and sound verbs similar to earlier observation for concrete nouns. Although the localizational value of ERPs must be viewed with caution, our results indicate that the meaning of verbs is linked to different neural circuits depending on conceptual feature relevance. PMID:28018201

  14. CNS-related (side-)effects of beta-blockers with special reference to mechanisms of action.

    PubMed

    Koella, W P

    1985-01-01

    beta-Adrenoreceptor antagonists are liable to produce behavioural side-effects such as drowsiness, fatigue, lethargy, sleep disorders, nightmares, depressive moods, and hallucinations. These undesirable actions indicate that beta-blockers affect not only peripheral autonomic activity but also some central nervous mechanisms. In experimental animals beta-blockers have been found to reduce spontaneous motor activity, to counteract isolation-, lesion-, stimulation- and amphetamine-induced hyperactivity, and to produce slow-wave and paradoxical sleep disturbances. Furthermore, central effects such as tranquilizing influences are used for the treatment of conditions such as anxiety. Several different mechanisms of action could be responsible for these CNS effects: Centrally mediated specific actions on centrally located beta-adrenergic receptors, known to exist downstream from, and at the terminals of, 'vigilance-enhancing' central noradrenergic pathways. Centrally mediated specific actions on centrally located receptors of the non-adrenergic type; an affinity of some beta-blockers towards 5-HT-receptors is well documented. Centrally mediated non-specific actions on centrally located neurones, owing to the membrane-stabilizing effects of beta-blockers. Peripherally mediated actions whereby beta-blockers induce changes in the autonomic activity in the periphery, which are relayed to the CNS to induce changes in activity of a variety of central systems. It can be assumed that with any one of the beta-blockers all these mechanisms come into play, yet with varying degrees depending on characteristics of the drugs such as lipophilicity and hydrophilicity, the ratio of antagonist versus (partial) agonist properties, affinity to 'alien' receptor sites, strength of membrane-stabilizing activity, stereospecific affinity, and potency.

  15. Effective action approach to cosmological perturbations in dark energy and modified gravity

    SciTech Connect

    Battye, Richard A.; Pearson, Jonathan A. E-mail: jp@jb.man.ac.uk

    2012-07-01

    In light of upcoming observations modelling perturbations in dark energy and modified gravity models has become an important topic of research. We develop an effective action to construct the components of the perturbed dark energy momentum tensor which appears in the perturbed generalized gravitational field equations, δG{sup μν} = 8πGδT{sup μν}+δU{sup μν} for linearized perturbations. Our method does not require knowledge of the Lagrangian density of the dark sector to be provided, only its field content. The method is based on the fact that it is only necessary to specify the perturbed Lagrangian to quadratic order and couples this with the assumption of global statistical isotropy of spatial sections to show that the model can be specified completely in terms of a finite number of background dependent functions. We present our formalism in a coordinate independent fashion and provide explicit formulae for the perturbed conservation equation and the components of δU{sup μ}{sub ν} for two explicit generic examples: (i) the dark sector does not contain extra fields, L = L(g{sub μν}) and (ii) the dark sector contains a scalar field and its first derivative L = L(g{sub μν},φ,∇{sub μ}φ). We discuss how the formalism can be applied to modified gravity models containing derivatives of the metric, curvature tensors, higher derivatives of the scalar fields and vector fields.

  16. Effects of stochastic channel gating and distribution on the cardiac action potential.

    PubMed

    Lemay, Mathieu; de Lange, Enno; Kucera, Jan P

    2011-07-21

    Ion channels exhibit stochastic conformational changes determining their gating behavior. In addition, the process of protein turnover leads to a natural variability of the number of membrane and gap junctional channels. Nevertheless, in computational models, these two aspects are scarcely considered and their impacts are largely unknown. We investigated the effects of stochastic current fluctuations and channel distributions on action potential duration (APD), intercellular conduction delays (ICDs) and conduction blocks using a modified ventricular cell model (Rudy et al.) with Markovian formulations of the principal ion currents (to simulate their stochastic open-close gating behavior) and with channel counts drawn from Poisson distributions (to simulate their natural variability). In single cells, APD variability (coefficient of variation: 1.6% at BCL=1000ms) was essentially caused by stochastic channel gating of I(Ks), persistent I(Na) and I(Ca,L). In cell strands, ICD variability induced by stochastic channel gating and Poissonian channel distributions was low under normal conditions. Nonetheless, at low intercellular coupling levels, Poissonian gap junctional channel distribution resulted in a large ICD variability (coefficient of variation >20%), highly heterogeneous conduction patterns and conduction blocks. Therefore, the stochastic behavior of current fluctuations and channel distributions can contribute to the heterogeneity of conduction patterns and to conduction block, as observed previously in experiments in cardiac tissue with altered intercellular coupling.

  17. Effect of visual field presentation on action planning (estimating reach) in children.

    PubMed

    Gabbard, Carl; Cordova, Alberto

    2012-01-01

    In this article, the authors examined the effects of target information presented in different visual fields (lower, upper, central) on estimates of reach via use of motor imagery in children (5-11 years old) and young adults. Results indicated an advantage for estimating reach movements for targets placed in lower visual field (LoVF), with all groups having greater difficulty in the upper visual field (UpVF) condition, especially 5- and 7-year-olds. Complementing these results was an overall age-related increase in accuracy. Based in part on the equivalence hypothesis suggesting that motor imagery and motor planning and execution are similar, the findings support previous work of executed behaviors showing that there is a LoVF bias for motor skill actions of the hand. Given that previous research hints that the UpVF may be bias for visuospatial (perceptual) qualities, research in that area and its association with visuomotor processing (LoVF) should be considered.

  18. Silver nanoparticles: mechanism of antimicrobial action, synthesis, medical applications, and toxicity effects

    NASA Astrophysics Data System (ADS)

    Prabhu, Sukumaran; Poulose, Eldho K.

    2012-10-01

    Silver nanoparticles are nanoparticles of silver which are in the range of 1 and 100 nm in size. Silver nanoparticles have unique properties which help in molecular diagnostics, in therapies, as well as in devices that are used in several medical procedures. The major methods used for silver nanoparticle synthesis are the physical and chemical methods. The problem with the chemical and physical methods is that the synthesis is expensive and can also have toxic substances absorbed onto them. To overcome this, the biological method provides a feasible alternative. The major biological systems involved in this are bacteria, fungi, and plant extracts. The major applications of silver nanoparticles in the medical field include diagnostic applications and therapeutic applications. In most of the therapeutic applications, it is the antimicrobial property that is being majorly explored, though the anti-inflammatory property has its fair share of applications. Though silver nanoparticles are rampantly used in many medical procedures and devices as well as in various biological fields, they have their drawbacks due to nanotoxicity. This review provides a comprehensive view on the mechanism of action, production, applications in the medical field, and the health and environmental concerns that are allegedly caused due to these nanoparticles. The focus is on effective and efficient synthesis of silver nanoparticles while exploring their various prospective applications besides trying to understand the current scenario in the debates on the toxicity concerns these nanoparticles pose.

  19. Effect of the combined action of Faradaic currents and mobility differences in ac electro-osmosis

    NASA Astrophysics Data System (ADS)

    González, A.; Ramos, A.; García-Sánchez, P.; Castellanos, A.

    2010-01-01

    In this work, we extend previous analyses of ac electro-osmosis to account for the combined action of two experimentally relevant effects: (i) Faradaic currents from electrochemical reactions at the electrodes and (ii) differences in ion mobilities of the electrolyte. In previous works, the ac electro-osmotic motion has been analyzed theoretically under the assumption that only forces in the diffuse (Debye) layer are relevant. Here, we first show that if the ion mobilities of a 1-1 aqueous solution are different, the charged zone expands from the Debye layer to include the diffusion layer. We later include the Faradaic currents and, as an attempt to explore both factors simultaneously, we perform a thin-layer, low-frequency, linear analysis of the system. Finally, the model is applied to the case of an electrolyte actuated by a traveling-wave signal. A steady liquid motion in opposite direction to the applied signal is predicted for some ranges of the parameters. This could serve as a partial explanation for the observed flow reversal in some experiments.

  20. Is India's policy framework geared for effective action on avoidable blindness from diabetes?

    PubMed Central

    Gaiha, Shivani M.; Shukla, Rajan; Gilbert, Clare E.; Anchala, Raghupathy; Gudlavalleti, Murthy V. S.

    2016-01-01

    Background: The growing burden of avoidable blindness caused by diabetic retinopathy (DR) needs an effective and holistic policy that reflects mechanisms for early detection and treatment of DR to reduce the risk of blindness. Materials and Methods: We performed a comprehensive health policy review to highlight the existing systemic issues that enable policy translation and to assess whether India's policy architecture is geared to address the mounting challenge of DR. We used a keyword-based Internet search for documents available in the last 15 years. Two reviewers independently assessed retrieved policies and extracted contextual and program-oriented information and components delineated in national policy documents. Using a “descriptive analytical” method, the results were collated and summarized as per themes to present status quo, gaps, and recommendations for the future. Results: Lack of focus on building sustainable synergies that require well laid out mechanisms for collaboration within and outside the health sector and poor convergence between national health programs appears to be the weakest links across policy documents. Conclusions: To reasonably address the issues of consistency, comprehensiveness, clarity, context, connectedness, and sustainability, policies will have to rely more strongly on evidence from operational research to support decisions. There is a need to involve multiple stakeholders from multiple sectors, recognize contributions from not-for-profit sector and private health service providers, and finally bring about a nuanced holistic perspective that has a voice with implementable multiple sector actions. PMID:27144136

  1. Immunomodulatory effects of fluoxetine: A new potential pharmacological action for a classic antidepressant drug?

    PubMed

    Di Rosso, María Emilia; Palumbo, María Laura; Genaro, Ana María

    2016-07-01

    Selective serotonin reuptake inhibitors are frequently used antidepressants. In particular, fluoxetine is usually chosen for the treatment of the symptoms of depression, obsessive-compulsive, panic attack and bulimia nervosa. Antidepressant therapy has been associated with immune dysfunction. However, there is contradictory evidence about the effect of fluoxetine on the immune system. Experimental findings indicate that lymphocytes express the serotonin transporter. Moreover it has been shown that fluoxetine is able to modulate the immune function through a serotonin-dependent pathway and through a novel independent mechanism. In addition, several studies have shown that fluoxetine can alter tumor cell viability. Thus, it was recently demonstrated in vivo that chronic fluoxetine treatment inhibits tumor growth by increasing antitumor T-cell activity. Here we briefly review some of the literature referring to how fluoxetine is able to modify, for better or worse, the functionality of the immune system. These results of our analysis point to the relevance of the novel pharmacological action of this drug as an immunomodulator helping to treat several pathologies in which immune deficiency and/or deregulation is present.

  2. The anti-melanogenic effect of pycnogenol by its anti-oxidative actions.

    PubMed

    Kim, You Jung; Kang, Ki Sung; Yokozawa, Takako

    2008-07-01

    Pycnogenol is a natural plant extract from pine bark that contains compounds that have anti-oxidative, free-radical scavenging properties. In this work, utilizing cultured B16 melanoma cells (B16 cells), pycnogenol was investigated for its ability to inhibit tyrosinase activity and melanin biosynthesis. We also examined the anti-oxidative power of pycnogenol by measuring its suppressive effect against peroxynitrite (ONOO-), superoxide (.O2), nitric oxide (NO.), and hydroxyl radical (.OH)-scavenging activities using an electron spin resonance spectrometer. Results show that pycnogenol had a strong anti-tyrosinase activity and suppressed melanin biosynthesis. Further, our results showed that through its anti-oxidative properties, pycnogenol suppressed .O2) NO., ONOO-, and .OH in in vitro assays, and reactive species, ONOO-, .O2, and NO., while up-regulating the reduced glutathione/oxidized glutathione ratio in B16 cells. Based on the findings, we propose that pycnogenol exerts anti-melanogenic activity via its anti-oxidative actions.

  3. Participatory Action Research: creating an effective prevention curriculum for adolescents in the Southwestern US.

    PubMed

    Gosin, M N; Dustman, P A; Drapeau, A E; Harthun, M L

    2003-06-01

    Existing research confirms a need to seek strategies that combine the strengths of researchers and community to create effective prevention curricula for youth. This article describes how components of Participatory Action Research (PAR) methodology were used to create the keepin' it REAL Drug Resistance Strategies (DRS) curriculum designed for a diverse Southwestern US youth population. School community participants were involved in multiple stages of creation and implementation. The research team developed a systematic process for creating lessons built upon strong theoretical foundations, while teachers and students contributed lesson modifications and evaluations, suggestions for supplemental activities, and the actual production of instructional videos. While the experimental design and some methodological constraints served to limit school community involvement in some phases of the DRS project, this article describes how PAR methodology ensured that researchers collaborated with school community members to create this promising drug prevention curriculum. Results of the REAL experiment, discussion of the use of this methodology, implications and recommendations for future research also are included.

  4. The effect and action mechanism of resveratrol on the vascular endothelial cell by high glucose treatment.

    PubMed

    Liu, Xun; Tian, Jie; Bai, Quanhao; Ashraf, Muhammad Aqeel; Sarfraz, Maliha; Zhao, Bojun

    2016-01-01

    To investigate the effect and action mechanism of resveratrol on the vascular endothelial cell by high glucose treatment. Primarily cultured human umbilical vein endothelial cells (HUVECs) were pretreated by resveratrol (0.2 μmol/L) and holding for 6 h, and then cultured in Dulbecco Modified Eagle Medium (DMEM) within 0.45 mmol/L of palmimte acid and 32.8 mmol/L of glucose, which is holding for 12 h. The cells were collected to analyze the expression of E-selected element. Supernatant of cultured cells, induced by 100 nmol/L insulin for 30 min, was used to analyze the nitric oxide content. Compared with normal control cells, the secretion of nitric oxide is stimulated by insulin decrease, however, the expression of E-selected element increased in HUVEC. Resveratrol treatment increased the secretion of nitric oxide stimulated by insulin and decreased the expression of E-selected element and partly counteracts the impairment of high glucose and palmitate acid on the function of endothelial cells. Resveratrol can improve and protect the function of high glucose and fatty acid cultured endothelial cell, and therefore may be a promising medicine in the prevention or therapy of diabetic macrovascular diseases.

  5. Allosteric Inhibitors Have Distinct Effects, but Also Common Modes of Action, in the HCV Polymerase

    PubMed Central

    Davis, Brittny C.; Brown, Jodian A.; Thorpe, Ian F.

    2015-01-01

    The RNA-dependent RNA polymerase from the Hepatitis C Virus (gene product NS5B) is a validated drug target because of its critical role in genome replication. There are at least four distinct allosteric sites on the polymerase to which several small molecule inhibitors bind. In addition, numerous crystal structures have been solved with different allosteric inhibitors bound to the polymerase. However, the molecular mechanisms by which these small molecules inhibit the enzyme have not been fully elucidated. There is evidence that allosteric inhibitors alter the intrinsic motions and distribution of conformations sampled by the enzyme. In this study we use molecular dynamics simulations to understand the structural and dynamic changes that result when inhibitors are bound at three different allosteric binding sites on the enzyme. We observe that ligand binding at each site alters the structure and dynamics of NS5B in a distinct manner. Nonetheless, our studies also highlight commonalities in the mechanisms of action of the different inhibitors. Each inhibitor alters the conformational states sampled by the enzyme, either by rigidifying the enzyme and preventing transitions between functional conformational states or by destabilizing the enzyme and preventing functionally relevant conformations from being adequately sampled. By illuminating the molecular mechanisms of allosteric inhibition, these studies delineate the intrinsic functional properties of the enzyme and pave the way for designing novel and more effective polymerase inhibitors. This information may also be important to understand how allosteric regulation occurs in related viral polymerases and other enzymes. PMID:25863069

  6. Effects of Action Video Game on Attention Distribution: A Cognitive Study

    NASA Astrophysics Data System (ADS)

    Zhang, Xuemin; Yan, Bin; Shu, Hua

    Based on the previous researches, Flanker compatibility effect paradigm was applied to explore the degree where people process the visual information presented on to-be-ignored locations. In present study, this paradigm was used to investigate attention distribution of Video Game Players (VGPs) and Non Video Game Players (NVGPs). The results suggested, under low perceptual load, VGPs tried to focus their attention on the task at-hand whereas the NVGPs tried to explore the adjacent locations with the left-over resources from the research task; however, under high perceptual load, the players would process the visual information at the adjacent locations of the target with the left-over resources, because they had comparatively greater attention capability, whereas the non-players focused their attention on the target locations to finish the search task. To conclude, the present study suggested that action video game play could not only enhance the attention capacity but also cause a different way of attention distribution in different perceptual load situations.

  7. Dissociable Effects of Dopamine on the Initial Capture and the Reactive Inhibition of Impulsive Actions in Parkinson's Disease

    PubMed Central

    van Wouwe, Nelleke C.; Kanoff, Kristen E.; Claassen, Daniel O.; Spears, Charis A.; Neimat, Joseph; van den Wildenberg, Wery P. M.; Wylie, Scott A.

    2016-01-01

    Dopamine plays a key role in a range of action control processes. Here, we investigate how dopamine depletion caused by Parkinson disease (PD) and how dopamine restoring medication modulate the expression and suppression of unintended action impulses. Fifty-five PD patients and 56 healthy controls (HCs) performed an action control task (Simon task). PD patients completed the task twice, once withdrawn from dopamine medications and once while taking their medications. PD patients experienced similar susceptibility to making fast errors in conflict trials as HCs, but PD patients were less proficient compared with HCs at suppressing incorrect responses. Administration of dopaminergic medications had no effect on impulsive error rates but significantly improved the proficiency of inhibitory control in PD patients. We found no evidence that dopamine precursors and agonists affected action control in PD differently. Additionally, there was no clear evidence that individual differences in baseline action control (off dopamine medications) differentially responded to dopamine medications (i.e., no evidence for an inverted U-shaped performance curve). Together, these results indicate that dopamine depletion and restoration therapies directly modulate the reactive inhibitory control processes engaged to suppress interference from the spontaneously activated response impulses but exert no effect on an individual's susceptibility to act on impulses. PMID:26836515

  8. Inelastic scattering of He atoms and NO(X2Pi) molecules: the role of parity on the differential cross section.

    PubMed

    Aoiz, F J; Verdasco, J E; Brouard, M; Kłos, J; Marinakis, S; Stolte, S

    2009-12-31

    Quasiclassical trajectory (QCT) and quantum mechanical (QM) close-coupling calculations have been used to study the state-resolved rotationally inelastic scattering of NO(X(2)Pi(1/2),v = 0,j = 1/2,e/f) by He on the most recent ab initio potential energy surface of J. Kłos et al. [J. Chem. Phys. 2000, 112, 2195.]. Opacity functions, and integral and differential cross sections are reported at collision energies of 63 and 147 meV and compared with previous theoretical calculations and experimental measurements on this and other systems. The existence of double peaks in the QCT and QM differential cross sections is examined in detail. While at a collision energy of 147 meV two rotational peaks appear in both the QCT and open-shell QM results, only a single peak is found in the QM calculations at the lower collision energy. The double peaks in the quantum-state-resolved differential cross sections (DCS) are found to be closely related to structure found in the corresponding state-resolved opacity functions. The structure in the QCT and QM DCSs is attributed to a flattening of the potential energy surface for sideways approach of He to the near-symmetric NO(X) molecule, and in both sets of calculations, it is shown to arise from a specific odd term in the expansion of the intermolecular potential. Although significant differences are found between the QCT and QM data in the forward scattered direction, and for higher final rotational levels, reflecting differences in the nature of the rotational rainbows observed in these two methods, in general, the QCT calculations are shown to give similar results to quantum theory. Furthermore, they provide valuable clues as to the mechanism of rotational energy transfer in this system.

  9. A spectroscopic study of nicotine analogue 2-phenylpyrrolidine (PPD) using resonant two-photon ionization (R2PI), microwave, and 2D NMR techniques.

    PubMed

    Martin, Danielle E; Robertson, Evan G; MacLellan, Jonathan G; Godfrey, Peter D; Thompson, Christopher D; Morrison, Richard J S

    2009-02-25

    Conformational preferences of the nicotine analogue 2-phenylpyrrolidine (PPD) have been studied in both gaseous and solution phases. Theoretical calculations at the MP2 and B3LYP levels point to 5-6 stable conformers which differ in three degrees of conformational freedom; torsion between the two rings, inversion at the pyrrolidine (PY) amine, and PY ring puckering, characterized using the Cremer-Pople definition for pseudorotation. Only one conformer has a trans arrangement between the amino hydrogen and the phenyl substituent. It is 6-8 kJ mol(-1) more stable than the cis conformers, has a perpendicular ring arrangement, and puckers at the nitrogen atom--similar to structures reported for nicotine. Resonant two-photon ionization (R2PI) data, including hole burn spectra, indicate only one conformer is present in the free jet expansion, and band contour analysis suggests assignment to the trans conformer. Confirmation was provided by microwave spectroscopy. Fifty-seven lines measured in the 48-72 GHz region were assigned to 206 b-type transitions and fitted to yield rotational constants within 2 MHz of MP2 values predicted for the trans conformer. The solution-phase conformers of PPD were studied using 1D and 2D (1)H NMR spectroscopy and solvent-based theoretical calculations. In marked contrast to the gas phase, NMR data reveals only cis conformers present in solution. Calculations confirm increased stability for these conformers when placed in simulated chloroform or water environments. Solvent molecules are believed to disrupt a crucial N...H(ortho) stabilizing interaction present within the trans conformer.

  10. Intracellular recordings of action potentials by an extracellular nanoscale field-effect transistor

    NASA Astrophysics Data System (ADS)

    Duan, Xiaojie; Gao, Ruixuan; Xie, Ping; Cohen-Karni, Tzahi; Qing, Quan; Choe, Hwan Sung; Tian, Bozhi; Jiang, Xiaocheng; Lieber, Charles M.

    2012-03-01

    The ability to make electrical measurements inside cells has led to many important advances in electrophysiology. The patch clamp technique, in which a glass micropipette filled with electrolyte is inserted into a cell, offers both high signal-to-noise ratio and temporal resolution. Ideally, the micropipette should be as small as possible to increase the spatial resolution and reduce the invasiveness of the measurement, but the overall performance of the technique depends on the impedance of the interface between the micropipette and the cell interior, which limits how small the micropipette can be. Techniques that involve inserting metal or carbon microelectrodes into cells are subject to similar constraints. Field-effect transistors (FETs) can also record electric potentials inside cells, and because their performance does not depend on impedance, they can be made much smaller than micropipettes and microelectrodes. Moreover, FET arrays are better suited for multiplexed measurements. Previously, we have demonstrated FET-based intracellular recording with kinked nanowire structures, but the kink configuration and device design places limits on the probe size and the potential for multiplexing. Here, we report a new approach in which a SiO2 nanotube is synthetically integrated on top of a nanoscale FET. This nanotube penetrates the cell membrane, bringing the cell cytosol into contact with the FET, which is then able to record the intracellular transmembrane potential. Simulations show that the bandwidth of this branched intracellular nanotube FET (BIT-FET) is high enough for it to record fast action potentials even when the nanotube diameter is decreased to 3 nm, a length scale well below that accessible with other methods. Studies of cardiomyocyte cells demonstrate that when phospholipid-modified BIT-FETs are brought close to cells, the nanotubes can spontaneously penetrate the cell membrane to allow the full-amplitude intracellular action potential to be

  11. Fine-tuning and vacuum stability in the Wilsonian effective action

    NASA Astrophysics Data System (ADS)

    Krajewski, Tomasz; Lalak, Zygmunt

    2015-10-01

    We have computed the Wilsonian effective action in a simple model with a spontaneously broken chiral parity. The Wilsonian running of relevant parameters makes it possible to discuss in a consistent manner the issues of fine-tuning and the stability of the scalar potential. This has been compared with the standard picture based on a Gell-Mann-Low running. Since the Wilsonian running automatically includes integration of heavy degrees of freedom, the running differs markedly from the Gell-Mann-Low version. Similar behavior can be observed: the scalar mass-squared parameter and the quartic coupling can change sign from a positive to a negative one, due to the running which causes a spontaneous symmetry breaking or an instability in the renormalizable part of the potential for a given range of scales. However, care must be taken when drawing conclusions, because of the truncation of higher-dimension operators. Taking the scalar field's amplitude near the cutoff Λ may cancel the suppression due to the scale, and only the suppression due to small couplings partially justifies the truncation in this region. Also, when taking the cutoff higher, to include larger amplitudes of the fields, the higher-order irrelevant operators, whose coefficients grow with the scale, may affect the conclusion about the stability. The Gell-Mann-Low running allows one to resume relatively easily a class of operators corresponding to large logarithms to the form of the renormalization group equation improved effective potential which is valid over a huge range of scales. In the Wilsonian approach this would correspond to following the running of a large number of irrelevant operators, which is technically problematic. As for the issue of the fine-tuning, since in the Wilsonian approach power-law terms are not subtracted, one can clearly observe the quadratic sensitivity of a fine-tuning measure to the change of the cutoff scale. The Wilsonian version of the radiative symmetry

  12. Melatonin nephroprotective action in Zucker diabetic fatty rats involves its inhibitory effect on NADPH oxidase.

    PubMed

    Winiarska, Katarzyna; Dzik, Jolanta M; Labudda, Mateusz; Focht, Dorota; Sierakowski, Bartosz; Owczarek, Aleksandra; Komorowski, Lukasz; Bielecki, Wojciech

    2016-01-01

    Excessive activity of NADPH oxidase (Nox) is considered to be of importance for the progress of diabetic nephropathy. The aim of the study was to elucidate the effect of melatonin, known for its nephroprotective properties, on Nox activity under diabetic conditions. The experiments were performed on three groups of animals: (i) untreated lean (?/+) Zucker diabetic fatty (ZDF) rats; (ii) untreated obese diabetic (fa/fa) ZDF rats; and (iii) ZDF fa/fa rats treated with melatonin (20 mg/L) in drinking water. Urinary albumin excretion was measured weekly. After 4 wk of the treatment, the following parameters were determined in kidney cortex: Nox activity, expression of subunits of the enzyme, their phosphorylation and subcellular distribution. Histological studies were also performed. Compared to ?/+ controls, ZDF fa/fa rats exhibited increased renal Nox activity, augmented expression of Nox4 and p47(phox) subunits, elevated level of p47(phox) phosphorylation, and enlarged phospho-p47(phox) and p67(phox) content in membrane. Melatonin administration to ZDF fa/fa rats resulted in the improvement of renal functions, as manifested by considerable attenuation of albuminuria and some amelioration of structural abnormalities. The treatment turned out to nearly normalize Nox activity, which was accompanied by considerably lowered expression and diminished membrane distribution of regulatory subunits, that is, phospho-p47(phox) and p67(phox) . Thus, it is concluded that: (i) melatonin beneficial action against diabetic nephropathy involves attenuation of the excessive activity of Nox; and (ii) the mechanism of melatonin inhibitory effect on Nox is based on the mitigation of expression and membrane translocation of its regulatory subunits.

  13. Superselective Particle Embolization Enhances Efficacy of Radiofrequency Ablation: Effects of Particle Size and Sequence of Action

    SciTech Connect

    Tanaka, Toshihiro; Isfort, Peter; Braunschweig, Till Westphal, Saskia; Woitok, Anna; Penzkofer, Tobias Bruners, Philipp; Kichikawa, Kimihiko; Schmitz-Rode, Thomas Mahnken, Andreas H.

    2013-06-15

    Purpose. To evaluate the effects of particle size and course of action of superselective bland transcatheter arterial embolization (TAE) on the efficacy of radiofrequency ablation (RFA). Methods. Twenty pigs were divided into five groups: group 1a, 40-{mu}m bland TAE before RFA; group 1b, 40-{mu}m bland TAE after RFA; group 2a, 250-{mu}m bland TAE before RFA; group 2b, 250-{mu}m bland TAE after RFA and group 3, RFA alone. A total of 40 treatments were performed with a combined CT and angiography system. The sizes of the treated zones were measured from contrast-enhanced CTs on days 1 and 28. Animals were humanely killed, and the treated zones were examined pathologically. Results. There were no complications during procedures and follow-up. The short-axis diameter of the ablation zone in group 1a (mean {+-} standard deviation, 3.19 {+-} 0.39 cm) was significantly larger than in group 1b (2.44 {+-} 0.52 cm; P = 0.021), group 2a (2.51 {+-} 0.32 cm; P = 0.048), group 2b (2.19 {+-} 0.44 cm; P = 0.02), and group 3 (1.91 {+-} 0.55 cm; P < 0.001). The greatest volume of ablation was achieved by performing embolization with 40-{mu}m particles before RFA (group 1a; 20.97 {+-} 9.65 cm{sup 3}). At histology, 40-{mu}m microspheres were observed to occlude smaller and more distal arteries than 250-{mu}m microspheres. Conclusion. Bland TAE is more effective before RFA than postablation embolization. The use of very small 40-{mu}m microspheres enhances the efficacy of RFA more than the use of larger particles.

  14. Cholecystokinin actions in the parabrachial nucleus: effects on thirst and salt appetite

    NASA Technical Reports Server (NTRS)

    Menani, J. V.; Johnson, A. K.

    1998-01-01

    The present study investigated the effects of bilateral injections of the nonselective CCK receptor antagonist proglumide or CCK-8 into the lateral parabrachial nuclei (LPBN) on the ingestion of 0.3 M NaCl and water induced by intracerebroventricular injection of ANG II or by a combined treatment with subcutaneous furosemide (Furo) + captopril (Cap). Compared with the injection of saline (vehicle), bilateral LPBN injections of proglumide (50 micrograms . 200 nl-1 . site-1) increased the intake of 0.3 M NaCl induced by intracerebroventricular ANG II (50 ng/1 microliter). Bilateral injections of proglumide into the LPBN also increased ANG II-induced water intake when NaCl was simultaneously available, but not when only water was present. Similarly, the ingestion of 0.3 M NaCl and water induced by the treatment with Furo (10 mg/kg) + Cap (5 mg/kg) was increased by bilateral LPBN proglumide pretreatment. Bilateral CCK-8 (0.5 microgram . 200 nl-1 . site-1) injections into the LPBN did not change Furo + Cap-induced 0.3 M NaCl intake but reduced water consumption. When only water was available after intracerebroventricular ANG II, bilateral LPBN injections of proglumide or CCK-8 had no effect or significantly reduced water intake compared with LPBN vehicle-treated rats. Taken together, these results suggest that CCK actions in the LPBN play a modulatory role on the control of NaCl and water intake induced by experimental treatments that induce hypovolemia and/or hypotension or that mimic those states.

  15. Hawking radiation from a Reissner-Nordstroem black hole with a global monopole via covariant anomalies and effective action

    SciTech Connect

    Gangopadhyay, Sunandan

    2008-08-15

    We adopt the covariant anomaly cancellation method as well as the effective action approach to obtain the Hawking radiation from the Reissner-Nordstroem blackhole with a global monopole falling in the class of the most general spherically symmetric charged blackhole ({radical}(-g){ne}1), using only covariant boundary conditions at the event horizon.

  16. 20 CFR 405.420 - Effect of Decision Review Board action on the right to seek judicial review.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... right to seek judicial review. 405.420 Section 405.420 Employees' Benefits SOCIAL SECURITY... § 405.420 Effect of Decision Review Board action on the right to seek judicial review. (a)(1) Subject to..., you may seek judicial review of the decision under section 205(g) of the Act within 60 days of...

  17. Parent Drug Education: A Participatory Action Research Study into Effective Communication about Drugs between Parents and Unrelated Young People

    ERIC Educational Resources Information Center

    Mallick, Jane

    2007-01-01

    Parent drug education is considered a key aspect of drug prevention. Effective communication acts as protective factor for drug misuse in young people. This study is a Participatory Action Research study of "Drugsbridge", a drug education programme that has an emphasis on facilitating intergenerational communication about drugs between parents and…

  18. 10 CFR 2.1327 - Application for a stay of the effectiveness of NRC staff action on license transfer.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Application for a stay of the effectiveness of NRC staff action on license transfer. 2.1327 Section 2.1327 Energy NUCLEAR REGULATORY COMMISSION RULES OF PRACTICE FOR DOMESTIC LICENSING PROCEEDINGS AND ISSUANCE OF ORDERS Procedures for Hearings on License...

  19. Estimating Individual Influences of Behavioral Intentions: An Application of Random-Effects Modeling to the Theory of Reasoned Action.

    ERIC Educational Resources Information Center

    Hedeker, Donald; And Others

    1996-01-01

    Methods are proposed and described for estimating the degree to which relations among variables vary at the individual level. As an example, M. Fishbein and I. Ajzen's theory of reasoned action is examined. This article illustrates the use of empirical Bayes methods based on a random-effects regression model to estimate individual influences…

  20. Effects of nandrolone decanoate on the toxicity and anti-tumour action of CCNU and FU in murine tumours.

    PubMed Central

    Bibby, M. C.; Double, J. A.; Mughal, M. A.

    1981-01-01

    Pre-treatment with the anabolic steroid nandrolone decanoate (ND) increases the LD50 of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) and 5-Fluorouracil (FU) in NMRI mice. Administration of ND did not affect the anti-tumour action of CCNU against a transplantable mouse adenocarcinoma of the colon (MAC 13) or the anti-tumour action of FU against MAC 26. In both tumour lines ND had no significant effect on tumour growth. These data suggest that an increase in the anti-tumour selectivity of these agents may be produced by pre-treatment with ND. PMID:7295514

  1. ENDOCRINE DISRUPTERS: A REVIEW OF SOME SOURCES, EFFECTS, AND MECHANISMS OF ACTIONS ON BEHAVIOR AND NEUROENDOCRINE SYSTEMS

    PubMed Central

    Frye, C.; Bo, E.; Calamandrei, G.; Calzà, L.; Dessì-Fulgheri, F.; Fernández, M.; Fusani, L.; Kah, O.; Kajta, M.; Le Page, Y.; Patisaul, H.B.; Venerosi, A.; Wojtowicz, A.K.; Panzica, G.C.

    2011-01-01

    Some environmental contaminants interact with hormones and may exert adverse consequences due to their actions as endocrine disrupting chemicals (EDCs). Exposure in people is typically due to contamination of the food chain, inhalation of contaminated house dust, or occupational exposure. EDCs include pesticides and herbicides (such as diphenyl-dichloro-trichloroethane, DDT, or its metabolites), methoxychlor, biocides, heat stabilizers and chemical catalysts (such as tributyltin, TBT), plastic contaminants (e.g. bisphenol A, BPA), pharmaceuticals (i.e. diethylstilbestrol, DES; 17alpha-ethynilestradiol, EE2), or dietary components (such as phytoestrogens). The goal of this review is to address sources, effects and actions of EDCs, with an emphasis on topics discussed at the International Congress on Steroids and the Nervous System. EDCs may alter reproductively-relevant or non-reproductive, sexually-dimorphic behaviors. In addition, EDCs may have significant effects on neurodevelopmental processes, influencing morphology of sexually-dimorphic cerebral circuits. Exposure to EDCs is more dangerous if it occurs during specific “critical periods” of life, such as intrauterine, perinatal, juvenile or puberty periods, when organisms are more sensitive to hormonal disruption, than in other periods. However, exposure to EDCs in adulthood also can alter physiology. Several EDCs are xenoestrogens, may alter serum lipid concentrations, or metabolism enzymes that are necessary for converting cholesterol to steroid hormones, ultimately altering production of E2 and/or other steroids. Finally, many EDCs may have actions via, or independent of, classic actions at cognate steroid receptors. EDCs may have effects through numerous other substrates, such as the aryl hydrocarbon receptor (AhR), the peroxisome proliferator-activated receptor (PPAR) and retinoid X receptor (RXR), signal transduction pathways, calcium influx, and/or neurotransmitter receptors. Thus, EDCs, from varied

  2. Effects of in-season plyometric training within soccer practice on explosive actions of young players.

    PubMed

    Meylan, César; Malatesta, Davide

    2009-12-01

    In soccer, explosive actions such as jumping, sprinting, and changes of direction are essential to optimal performance not only in adults, but also in children's games. The purpose of the present investigation was to determine the influence of a short-term plyometric training within regular soccer practice on explosive actions of early pubertal soccer players during the in-season. Fourteen children (13.3 +/- 0.6 years) were selected as the training group (TG) and 11 children (13.1 +/- 0.6 years) were defined as the control group (CG). All children were playing in the same league and trained twice per week for 90 minutes with the same soccer drills. The TG followed an 8-week plyometric program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented as a substitute for some soccer drills to obtain the same session duration as CG. At baseline and after training, explosive actions were assessed with the following 6 tests: 10-meter sprint, agility test, 3 vertical jump tests (squat jump [SJ], countermovement jump [CMJ], contact test [CT] and multiple 5 bounds test [MB5]). Plyometric training was associated with significant decreases in 10-m sprint time (-2.1%) and agility test time (-9.6%) and significant increases in jump height for the CMJ (+7.9%) and CT (+10.9%). No significant changes in explosive actions after the 8-week period were recorded for the CG. The current study demonstrated that a plyometric program within regular soccer practice improved explosive actions of young players compared to conventional soccer training only. Therefore, the short-term plyometric program had a beneficial impact on explosive actions, such as sprinting, change of direction, and jumping, which are important determinants of match-winning actions in soccer performance.

  3. Liver tumor promoting effect of omeprazole in rats and its possible mechanism of action.

    PubMed

    Hayashi, Hitomi; Shimamoto, Keisuke; Taniai, Eriko; Ishii, Yuji; Morita, Reiko; Suzuki, Kazuhiko; Shibutani, Makoto; Mitsumori, Kunitoshi

    2012-01-01

    Omeprazole (OPZ), a proton pump inhibitor, is a cytochrome P450 (CYP) 1A1/2 inducer. Some CYP1A inducers are known to have liver tumor promoting effects in rats and the ability to enhance oxidative stress. In this study, we performed a two-stage liver carcinogenesis bioassay in rats to examine the tumor promoting effect of OPZ (Experiment 1) and to clarify a possible mechanism of action (Experiment 2). In Experiment 1, male F344 rats were subjected to a two-third partial hepatectomy, and treated with 0, 138 or 276 mg/kg OPZ by oral gavage once a day for six weeks after an intraperitoneal injection of N-diethylnitrosamine (DEN). Liver weights significantly increased in the DEN+OPZ groups, and the number and area of glutathione S-transferase placental form (GST-P) positive foci significantly increased in the DEN+276 mg/kg OPZ group. In Experiment 2, the same experiment as Experiment 1 was performed, but the dosage of OPZ was 0 or 276 mg/kg. The number and area of GST-P positive foci as well as liver weights significantly increased in the DEN+276 mg/kg OPZ group. The number of proliferative cell nuclear antigen (PCNA)-positive cells also significantly increased in the same group. Real-time RT-PCR showed that the expression of AhR battery genes including Cyp1a1, Cyp1a2, Ugt1a6 and Nqo1, and Nrf2 battery genes including Gpx2, Yc2, Akr7a3, Aldh1a1 Me1 and Ggt1 were significantly upregulated in this group. However, the production of microsomal reactive oxygen species (ROS) and formation of thiobarbituric acid-reactive substances (TBARS) decreased, and 8-hydroxydeoxyguanosine (8-OHdG) content remained unchanged in this group. These results indicate that OPZ, CYP1A inducer, is a liver tumor promoter in rats, but oxidative stress is not involved in the liver tumor promoting effect of OPZ.

  4. Systemic and coronary hemodynamic actions and left ventricular functional effects of levosimendan in conscious dogs.

    PubMed

    Harkin, C P; Pagel, P S; Tessmer, J P; Warltier, D C

    1995-08-01

    control to 29 +/- 1 ms at the high dose) and increased the magnitude of LV -dP/dtmin in dogs with intact but not blocked ANS reflexes, suggesting that relaxation was enhanced by favorable changes in systemic hemodynamics or ANS activation and direct effects of this drug on lusitropic state. Levosimendan also increased dL/dtmax to a greater degree in ANS-intact dogs, indicating that improvement of rapid ventricular filling was also partially dependent on ANS tone. No changes in Kp were observed in either experimental group. The results indicate that levosimendan decreases preload and afterload and has positive inotropic and lusitropic properties. The actions of levosimendan on diastolic function are largely mediated by the ANS.

  5. Time for actions in lucid dreams: effects of task modality, length, and complexity.

    PubMed

    Erlacher, Daniel; Schädlich, Melanie; Stumbrys, Tadas; Schredl, Michael

    2013-01-01

    The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.

  6. Effect of knockout of α2δ-1 on action potentials in mouse sensory neurons

    PubMed Central

    Margas, Wojciech; Ferron, Laurent; Nieto-Rostro, Manuela; Schwartz, Arnold; Dolphin, Annette C.

    2016-01-01

    Gene deletion of the voltage-gated calcium channel auxiliary subunit α2δ-1 has been shown previously to have a cardiovascular phenotype, and a reduction in mechano- and cold sensitivity, coupled with delayed development of neuropathic allodynia. We have also previously shown that dorsal root ganglion (DRG) neuron calcium channel currents were significantly reduced in α2δ-1 knockout mice. To extend our findings in these sensory neurons, we have examined here the properties of action potentials (APs) in DRG neurons from α2δ-1 knockout mice in comparison to their wild-type (WT) littermates, in order to dissect how the calcium channels that are affected by α2δ-1 knockout are involved in setting the duration of individual APs and their firing frequency. Our main findings are that there is reduced Ca2+ entry on single AP stimulation, particularly in the axon proximal segment, reduced AP duration and reduced firing frequency to a 400 ms stimulation in α2δ-1 knockout neurons, consistent with the expected role of voltage-gated calcium channels in these events. Furthermore, lower intracellular Ca2+ buffering also resulted in reduced AP duration, and a lower frequency of AP firing in WT neurons, mimicking the effect of α2δ-1 knockout. By contrast, we did not obtain any consistent evidence for the involvement of Ca2+-activation of large conductance calcium-activated potassium (BK) and small conductance calcium-activated potassium (SK) channels in these events. In conclusion, the reduced Ca2+ elevation as a result of single AP stimulation is likely to result from the reduced duration of the AP in α2δ-1 knockout sensory neurons. This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’. PMID:27377724

  7. Time for actions in lucid dreams: effects of task modality, length, and complexity

    PubMed Central

    Erlacher, Daniel; Schädlich, Melanie; Stumbrys, Tadas; Schredl, Michael

    2014-01-01

    The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations. PMID:24474942

  8. Effect of rapid delayed rectifier current on hysteresis in restitution of action potential duration in swine.

    PubMed

    Agarwal, Anuj; Jing, Linyuan; Patwardhan, Abhijit

    2012-01-01

    Electrical stability in the heart depends on two important factors; restitution of action potential duration (APD) and memory. Repolarization currents play an important role in determining APD and also affect memory. We determined the effects of blocking the rapid component of the delayed rectifier (I(Kr)) on a quantifiable measure of memory, i.e. hysteresis in restitution of APD, in swine. Transmembrane potentials were recorded from right ventricular endocardial tissues. Two pacing protocols with explicit control of diastolic interval (DI) were used to change DIs in a sequential and sinusoidal pattern to quantify hysteresis in restitution of APD. E-4031 (5 µM/L) was used to block I(Kr). Measures of memory and restitution were quantified by calculating hysteresis loop thickness, area, overall tilt, and maximum and minimum delays between DIs and APDs. Blocking I(Kr) with E-4031 increased the baseline APD, loop thickness, area, and tilt (p<0.05). However, loop thickness did not increase beyond what could be predicted by the increase in baseline APD after block of I(Kr). The substantial change in APD after blocking I(Kr) suggests that this current plays a major role in repolarization in the swine. Loop thickness is a measure of memory, an increase in which is predicted by theory to reduce instability in activation. In our study, the substantial increase in loop thickness could be accounted for by an equally substantial increase in APD and therefore does not necessarily indicate increased memory after blocking I(Kr). Our results also suggest that factors based on restitution and memory need to be considered in the context of operating point, i.e. baseline APD, when they are used to explore mechanisms that affect electrical stability in the heart.

  9. Diarrhetic effect of okadaic acid could be related with its neuronal action: Changes in neuropeptide Y.

    PubMed

    Louzao, M Carmen; Fernández, Diego A; Abal, Paula; Fraga, Maria; Vilariño, Natalia; Vieytes, Mercedes R; Botana, Luis M

    2015-09-02

    Okadaic acid (OA) and dinophysistoxins (DTXs) are a group of marine toxins that cause diarrheic shellfish poisoning (DSP) in humans and animals. These compounds are produced by dinoflagellates of the Prorocentrum and Dinophysis genera and can accumulate in filter-feeding bivalves, posing a serious health risk for shellfish consumers. The enteric nervous system (ENS) plays a crucial role in the regulation of the gastrointestinal tract. In addition, neuropeptides produced by ENS affects the epithelial barrier functions. In the present work we used a two-compartment human coculture model containing the SH-SY5Y neuroblastoma cell line and polarized colonic epithelial monolayers (Caco-2) to study the OA intestinal permeability. First, we have determined OA cytotoxicity and we have found that OA reduces the viability of SH-SY5Y in a dose-dependent way, even though DTX1 is 4 to 5 times more potent than OA. Besides DTX1 is 15 to 18 orders of magnitude more potent than OA in decreasing transepithelial electrical resistance (TEER) of caco-2 cells without inducing cytotoxicity. Permeability assays indicate that OA cross the monolayer and modulates the neuropeptide Y (NPY) secretion by neuroblastoma cells. This NPY also affects the permeability of OA. This offers a novel approach to establish the influence of OA neuronal action on their diarrheic effects through a cross talk between ENS and intestine via OA induced NPY secretion. Therefore, the OA mechanisms of toxicity that were long attributed only to the inhibition of protein phosphatases, would require a reevaluation.

  10. An integrated approach for prospectively investigating a mode-of-action for rodent liver effects.

    PubMed

    LeBaron, Matthew J; Geter, David R; Rasoulpour, Reza J; Gollapudi, B Bhaskar; Thomas, Johnson; Murray, Jennifer; Kan, H Lynn; Wood, Amanda J; Elcombe, Cliff; Vardy, Audrey; McEwan, Jillian; Terry, Claire; Billington, Richard

    2013-07-15

    Registration of new plant protection products (e.g., herbicide, insecticide, or fungicide) requires comprehensive mammalian toxicity evaluation including carcinogenicity studies in two species. The outcome of the carcinogenicity testing has a significant bearing on the overall human health risk assessment of the substance and, consequently, approved uses for different crops across geographies. In order to understand the relevance of a specific tumor finding to human health, a systematic, transparent, and hypothesis-driven mode of action (MoA) investigation is, appropriately, an expectation by the regulatory agencies. Here, we describe a novel approach of prospectively generating the MoA data by implementing additional end points to the standard guideline toxicity studies with sulfoxaflor, a molecule in development. This proactive MoA approach results in a more robust integration of molecular with apical end points while minimizing animal use. Sulfoxaflor, a molecule targeting sap-feeding insects, induced liver effects (increased liver weight due to hepatocellular hypertrophy) in an initial palatability probe study for selecting doses for subsequent repeat-dose dietary studies. This finding triggered the inclusion of dose-response investigations of the potential key events for rodent liver carcinogenesis, concurrent with the hazard assessment studies. As predicted, sulfoxaflor induced liver tumors in rats and mice in the bioassays. The MoA data available by the time of the carcinogenicity finding supported the conclusion that the carcinogenic potential of sulfoxaflor was due to CAR/PXR nuclear receptor activation with subsequent hepatocellular proliferation. This MoA was not considered to be relevant to humans as sulfoxaflor is unlikely to induce hepatocellular proliferation in humans and therefore would not be a human liver carcinogen.

  11. Sexual Assault: Actions Needed to Improve DOD’s Prevention Strategy and to Help Ensure It Is Effectively Implemented

    DTIC Science & Technology

    2015-11-01

    SEXUAL ASSAULT Actions Needed to Improve DOD’s Prevention Strategy and to Help Ensure It Is Effectively...to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE NOV 2015 2. REPORT TYPE 3...Ensure It Is Effectively Implemented 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER

  12. Protective effect of dietary potassium against cardiovascular damage in salt-sensitive hypertension: possible role of its antioxidant action.

    PubMed

    Ando, Katsuyuki; Matsui, Hiromitsu; Fujita, Megumi; Fujita, Toshiro

    2010-01-01

    It is well known that high salt intake induces hypertension and cardiovascular damage, while dietary potassium supplementation counteracts these harmful effects. Actually, the protective effect of potassium is strengthened with excess salt as compared with salt depletion. Although the precise mechanisms have not been fully elucidated, in our previous reports, the antihypertensive effect of dietary potassium was accompanied by sympathetic nerve inhibition in salt-sensitive hypertension. Also, potassium supplement suppressed salt-induced insulin resistance. These effects of dietary potassium can explain its cardio- and vasculo-protective action in addition to the potassium supplementation induced decreased salt-induced rise in blood pressure. On the other hand, salt-sensitive hypertension is associated with reactive oxygen species (ROS) overproduction. Moreover, sympathoexcitation can be induced by central ROS upregulation and insulin resistance can be caused by ROS excess in the target organs of insulin, such as skeletal muscle. Conversely, the seemingly different actions of potassium can be explained by the antioxidant effect of dietary potassium; in our recent studies, potassium supplementation inhibits salt-induced progress of cardiac diastolic dysfunction and vascular neointima formation by cuff placement around arteries, associated with the inhibition of regional ROS overproduction, in salt-sensitive hypertension. Thus, it is possible that dietary potassium protects against salt-induced cardiovascular damage by the reduction of ROS generation and by central sympatholytic action and amelioration of insulin resistance induced through its antioxidant effect.

  13. Different mechanisms for role relations versus verb-action congruence effects: evidence from ERPs in picture-sentence verification.

    PubMed

    Knoeferle, Pia; Urbach, Thomas P; Kutas, Marta

    2014-10-01

    Extant accounts of visually situated language processing do make general predictions about visual context effects on incremental sentence comprehension; these, however, are not sufficiently detailed to accommodate potentially different visual context effects (such as a scene-sentence mismatch based on actions versus thematic role relations, e.g., (Altmann & Kamide, 2007; Knoeferle & Crocker, 2007; Taylor & Zwaan, 2008; Zwaan & Radvansky, 1998)). To provide additional data for theory testing and development, we collected event-related brain potentials (ERPs) as participants read a subject-verb-object sentence (500 ms SOA in Experiment 1 and 300 ms SOA in Experiment 2), and post-sentence verification times indicating whether or not the verb and/or the thematic role relations matched a preceding picture (depicting two participants engaged in an action). Though incrementally processed, these two types of mismatch yielded different ERP effects. Role-relation mismatch effects emerged at the subject noun as anterior negativities to the mismatching noun, preceding action mismatch effects manifest as centro-parietal N400s greater to the mismatching verb, regardless of SOAs. These two types of mismatch manipulations also yielded different effects post-verbally, correlated differently with a participant's mean accuracy, verbal working memory and visual-spatial scores, and differed in their interactions with SOA. Taken together these results clearly implicate more than a single mismatch mechanism for extant accounts of picture-sentence processing to accommodate.

  14. Exploring perceptual processing of ASL and human actions: Effects of inversion and repetition priming

    PubMed Central

    Corina, David P.; Grosvald, Michael

    2011-01-01

    In this paper, we compare responses of deaf signers and hearing non-signers engaged in a categorization task of signs and non-linguistic human actions. We examine the time it takes to make such categorizations under conditions of 180-degree stimulus inversion and as a function of repetition priming, in an effort to understand whether the processing of sign language forms draws upon special processing mechanisms or makes use of mechanisms used in recognition of non-linguistic human actions. Our data show that deaf signers were much faster in the categorization of both linguistic and non-linguistic actions, and relative to hearing non-signers, show evidence that they were more sensitive to the configural properties of signs. Our study suggests that sign expertise may lead to modifications of a general-purpose human action recognition system rather than evoking a qualitatively different mode of processing, and supports the contention that signed languages make use of perceptual systems through which humans understand or parse human actions and gestures more generally. PMID:22153323

  15. Choosing Actions

    PubMed Central

    Rosenbaum, David A.; Chapman, Kate M.; Coelho, Chase J.; Gong, Lanyun; Studenka, Breanna E.

    2013-01-01

    Actions that are chosen have properties that distinguish them from actions that are not. Of the nearly infinite possible actions that can achieve any given task, many of the unchosen actions are irrelevant, incorrect, or inappropriate. Others are relevant, correct, or appropriate but are disfavored for other reasons. Our research focuses on the question of what distinguishes actions that are chosen from actions that are possible but are not. We review studies that use simple preference methods to identify factors that contribute to action choices, especially for object-manipulation tasks. We can determine which factors are especially important through simple behavioral experiments. PMID:23761769

  16. Defining soldier equipment trade space: load effects on combat marksmanship and perception-action coupling.

    PubMed

    Palmer, Christopher J; Bigelow, Carol; Van Emmerik, Richard E A

    2013-01-01

    Soldier equipment compromises task performance as temporal constraints during critical situations and load increase inertial and interactive forces during movement. Methods are necessary to optimise equipment that relate task performance to underlying coordination and perception-action coupling. Employing ecological task analysis and methods from dynamical systems theory, equipment load and coordination was examined during two sub-tasks embedded in combat performance, threat discrimination and dynamic marksmanship. Perception-action coupling was degraded with load during threat discrimination, leading to delays in functional reaction time. Reduced speed and accuracy during dynamic marksmanship under load was related to disrupted segmental coordination and adaptability during postural transitions between targets. These results show how reduced performance under load relates to coordination changes and perception-action coupling. These changes in functional capability are directly related to soldier survivability in combat. The methods employed may aid equipment design towards more optimised performance by modifying equipment or its distribution on humans.

  17. Rate constants and H atom branching ratios of the gas-phase reactions of methylidyne CH(X2Pi) radical with a series of alkanes.

    PubMed

    Loison, Jean-Christophe; Bergeat, Astrid; Caralp, Françoise; Hannachi, Yacine

    2006-12-21

    The reactions of the CH radical with several alkanes were studied, at room temperature, in a low-pressure fast-flow reactor. CH(X2Pi, v = 0) radicals were obtained from the reaction of CHBr(3) with potassium atoms. The overall rate constants at 300 K are (0.76 +/- 0.20) x 10(-10) [Fleurat-Lessard, P.; Rayez, J. C.; Bergeat, A.; Loison, J. C. Chem. Phys. 2002, 279, 87],1 (1.60 +/- 0.60) x 10(-10)[Galland, N.; Caralp, F.; Hannachi, Y.; Bergeat, A.; Loison, J.-C. J. Phys. Chem. A 2003, 107, 5419],2 (2.20 +/- 0.80) x 10(-10), (2.80 +/- 0.80) x 10(-10), (3.20 +/- 0.80) x 10(-10), (3.30 +/- 0.60) x 10(-10), and (3.60 +/- 0.80) x 10(-10) cm3 molecule(-1) s(-1), (errors refer to +/-2sigma) for methane, ethane, propane, n-butane, n-pentane, neo-pentane, and n-hexane respectively. The experimental overall rate constants correspond to those obtained using a simple classical capture theory. Absolute atomic hydrogen production was determined by V.U.V. resonance fluorescence, with H production from the CH + CH4 reaction being used as a reference. Observed H branching ratios were for CH4, 1.00[Fleurat-Lessard, P.; Rayez, J. C.; Bergeat, A.; Loison, J. C. Chem. Phys. 2002, 279, 87];1 C(2)H(6), 0.22 +/- 0.08 [Galland, N.; Caralp, F.; Hannachi, Y.; Bergeat, A.; Loison, J.-C. J. Phys. Chem. A 2003, 107, 5419];2 C(3)H(8), 0.19 +/- 0.07; C(4)H(10) (n-butane), 0.14 +/- 0.06; C(5)H(12) (n-pentane), 0.52 +/- 0.08; C(5)H(12) (neo-pentane), 0.51 +/- 0.08; C(5)H(12) (iso-pentane), 0.12 +/- 0.06; C(6)H(14) (n-hexane), 0.06 +/- 0.04.

  18. Selective effects of potassium elevations on glutamate signaling and action potential conduction in hippocampus.

    PubMed

    Meeks, Julian P; Mennerick, Steven

    2004-01-07

    High-frequency synaptic transmission is depressed by moderate rises in the extracellular potassium concentration ([K+]o). Previous reports have indicated that depression of action potential signaling may underlie the synaptic depression. Here, we investigated the specific contribution of K+-induced action potential changes to synaptic depression. We found that glutamatergic transmission in the hippocampal area CA1 was significantly depressed by 8-10 mM [K+]o, but that GABAergic transmission remained intact. Riluzole, a drug that slows recovery from inactivation of voltage-gated sodium channels (NaChs), interacts with subthreshold [K+]o to depress afferent volleys and EPSCs strongly. Thus, elevated [K+]o likely depresses synapses by slowing NaCh recovery from inactivation. It is unclear from previous studies whether [K+]o-induced action potential depression is caused by changes in initiation, reliability, or waveform. We investigated these possibilities explicitly. [K+]o-induced afferent volley depression was independent of stimulus strength, suggesting that changes in action potential initiation do not explain [K+]o-induced depression. Measurements of action potentials from single axons revealed that 8 mM [K+]o increased conduction failures in a subpopulation of fibers and depressed action potential amplitude in all fibers. Together, these changes quantitatively account for the afferent volley depression. We estimate that conduction failure explains more than half of the synaptic depression observed at 8 mM [K+]o, with the remaining depression likely explained by waveform changes. These mechanisms of selective sensitivity of glutamate release to [K+]o accumulation represent a unique neuromodulatory mechanism and a brake on runaway excitation.

  19. [The interrelation of the antimutagenic action of mannitol to its effect on cellular metabolic processes].

    PubMed

    Aliev, A A; Ragimova, G K; Gadzhiev, R R; Alekperov, U K

    1992-01-01

    The mannitol influence on mutagenesis of ionizing radiation and cyclophosphate has been studied in albino mongrel rats using the methods of genetic and biochemical analysis. N correlation is determined between antimutagenic action of this preparation and a decrease of malondialdehyde content in cells and free fractions of matrix lysosomes (beta-galactosidase; N-acetyl-beta-D-glucosaminidase) and firmly membrane-structurized microsomal (glucose-6-phosphatase) enzymes, whose level increases under the influence of mutagens. It is shown that, one of the way of antimutagenic actions of mannitol is connected with mutagenesis correction at the stage of origin of mutagenic products and their transport to chromosome DNA.

  20. Hyperfine structure and Zeeman tuning of the A {sup 2}PI-X {sup 2}SIGMA{sup +}(0,0) band system of the odd isotopologue of strontium monofluoride {sup 87}SrF

    SciTech Connect

    Le, Anh T.; Wang Hailing; Steimle, Timothy C.

    2009-12-15

    The low-rotational lines of the A {sup 2}PI-X {sup 2}SIGMA{sup +}(0,0) band system of the odd isotopologue of strontium monofluoride, {sup 87}SrF, were recorded and analyzed. The {sup 87}Sr(I=9/2) magnetic hyperfine interaction is significant only in the |OMEGA|=1/2 spin-orbit component of the A {sup 2}PI state. Optical transitions appropriate for monitoring ultracold samples of {sup 87}SrF are identified. The determined fine-structure parameters were used to predict the anisotropic magnetic g factor, g{sub l}, for the X {sup 2}SIGMA{sup +}(v=0) state. The g factors were used to predict the magnetic tuning of the N=0 (+parity) and N=1 (-parity) levels of the X {sup 2}SIGMA{sup +}(v=0) state. A comparison to spectroscopic parameters for the {sup 88}SrF isotopologue is given.

  1. Res Judicata and Section 1983: The Effect of State Court Judgments on Federal Civil Rights Actions.

    ERIC Educational Resources Information Center

    Levenson, Laurie L.

    1979-01-01

    Argues for a consistent approach to determining when Section 1983 litigation may follow state proceedings. Provides guidelines similar to those applied in habeas corpus proceedings for deciding when federal action will be barred. Available from UCLA Law Review, 405 Hilgard Ave., Los Angeles, CA 90024. (IRT)

  2. Exploring Perceptual Processing of ASL and Human Actions: Effects of Inversion and Repetition Priming

    ERIC Educational Resources Information Center

    Corina, David P.; Grosvald, Michael

    2012-01-01

    In this paper, we compare responses of deaf signers and hearing non-signers engaged in a categorization task of signs and non-linguistic human actions. We examine the time it takes to make such categorizations under conditions of 180 degrees stimulus inversion and as a function of repetition priming, in an effort to understand whether the…

  3. Understanding Teacher Effectiveness: Providing Feedback to Teacher Preparation Programs. Data for Action 2013

    ERIC Educational Resources Information Center

    Data Quality Campaign, 2014

    2014-01-01

    Teachers need longitudinal student-level data, such as attendance history, course-taking patterns, grades, and test scores, to tailor instruction to individual students' strengths and weaknesses.This factsheet uses the findings from the Data for Action 2013 analysis to discuss how states can provide teachers with student-level longitudinal data,…

  4. Taking Action--Mathematics Curricular Organization for Effective Teaching and Learning

    ERIC Educational Resources Information Center

    Appelbaum, Peter

    2009-01-01

    The curricular structure of Taking Action is described and analyzed as a form of culturally responsive and culturally specific pedagogy. In this design structure, students reconsider what they have done and identify key aspects of their experience. Based on this reflection, they design a way to interact with people outside of their class in order…

  5. An Action Research Study on the Effect of Interactive Technology and Active Learning on Student Performance

    ERIC Educational Resources Information Center

    Bear, Teresa J.

    2013-01-01

    This quantitative action science research study utilized a causal-comparative experimental research design in order to determine if the use of student response systems (clickers), as an active learning strategy in a community college course, improved student performance in the course. Students in the experimental group (n = 26) used clickers to…

  6. Re-Mediating Practitioners' Practice for Equity in Higher Education: Evaluating the Effectiveness of Action Research

    ERIC Educational Resources Information Center

    Vines, Erin

    2012-01-01

    This study examines the influence of action research on California community college practitioners' attitudes, beliefs, and behavior using the Center for Urban Education's (CUE) Equity Scorecard tools and process. This developmental evaluation study began March 2011 and concluded April 2012. The pseudonym of the field site studied is Las Flores…

  7. Effects of Noun-Verb Homonymy on the Neural Correlates of Naming Concrete Entities and Actions

    ERIC Educational Resources Information Center

    Tranel, D.; Martin, C.; Damasio, H.; Grabowski, T.J.; Hichwa, R.

    2005-01-01

    The neural correlates of naming concrete entities such as tools (with nouns) and naming actions (with verbs) are partially distinct: the former are linked to the left inferotemporal (IT) region, whereas the latter are linked to the left frontal opercular (FO) and left posterior middle temporal (MT) regions. This raises an intriguing question: How…

  8. The Effects of Varied Inquiry Experiences on Teacher and Student Questions and Actions in STS Classrooms

    ERIC Educational Resources Information Center

    Yager, Robert E.; Abd-Hamid, Nor Hashidah; Akcay, Hakan

    2005-01-01

    The purpose of this study was to examine how different inquiry experiences affect in-service science teachers' performance in terms of their questions and classroom actions. Teachers in a workshop experience proceeded through structured, guided, and full inquiry stations where materials to make foam were provided. Participants were 26 in-service…

  9. Effects of a Long-Term Participatory Action Research Project on Science Teachers' Professional Development

    ERIC Educational Resources Information Center

    Eilks, Ingo; Markic, Silvija

    2011-01-01

    This paper describes the potential of long-term co-operation between science educators and science teachers concerning the teachers' continuous professional development, based on Participatory Action Research in science education. The discussion is based on a six-year case study observing a group of about ten German chemistry teachers by chemistry…

  10. Effects of preparatory and action planning instructions on situation-specific and general fruit and snack intake.

    PubMed

    de Bruijn, Gert-Jan; Nguyen, Minh Hao; Rhodes, Ryan E; van Osch, Liesbeth

    2017-01-01

    Evidence to date suggests heterogeneity in the effects of implementation intentions on health behaviour, including diet. Additional variables and study designs may impact on their effectiveness. Preparatory action, such as making sure fruits are available for consumption, may be an important additional variable. Likewise, most implementation intention research has focused on changes in general intake, yet implementation intention instructions typically require participants to consider behaviour in specific situations. Little is known on how implementation intentions impact situation-specific intake. The present study sought to add to the evidence base by comparing (1) the effects of action planning instructions versus preparatory planning instructions on (2) both situation-specific (as formulated in the implementation intention instruction) and general intake of fruits and in-between meal snack intake frequency. Fruit intake was assessed in average pieces per day, whereas snacking intake was assessed as average frequency in days per week. Using non-probability sampling, 243 undergraduate students who intended to have a healthy diet were randomized to either a standard information control condition, an action planning condition, or a preparatory planning condition. Planning manipulations were based on previous work. Two weeks later, general and situation-specific intake was assessed again in 181 participants. Data were analysed using 2 (time) x 3 (conditions) analyses of variance. Results showed that both planning manipulations were successful in decreasing snack intake frequency in the specified situation, with larger effect sizes for the action planning condition than for the preparatory planning condition. No effects were found on general snack intake frequency or fruit intake. Future planning interventions should more explicitly compare changes in situational and general intake, as well as simultaneously assessed decreases in unhealthy intake and increases in

  11. Effect of meal type on specific dynamic action in the green shore crab, Carcinus maenas.

    PubMed

    McGaw, Iain J; Penney, Chantelle M

    2014-05-01

    The effect of meal type on specific dynamic action was investigated in the green shore crab, Carcinus maenas. When the crabs were offered a meal of fish, shrimp, or mussel of 3 % of their body mass the duration of the SDA response and thus the resultant SDA was lower for the mussel, compared with the shrimp or fish meals. In feeding behaviour experiments the crabs consumed almost twice as much mussel compared with fish or shrimp. When the animals were allowed to feed on each meal until satiated, the differences in the SDA response were abolished. The mussel was much softer (compression test) than the fish or shrimp meal, and meal texture is known to affect the SDA response in amphibians and reptiles. When the crabs were offered a meal of homogenized fish muscle or whole fish muscle, the SDA for the homogenized meal was approximately 35 % lower. This suggested that a significant portion of the SDA budget in decapod crustaceans may be related to mechanical digestion. This is not unexpected since the foregut is supplied by over forty muscles which control the cutting and grinding movements of the gastric mill apparatus. There were slight, but significant differences in protein, lipid, moisture and total energy content of each meal type. Three prepared meals that were high in either protein, lipid or carbohydrate were offered to the crabs to determine if the nutrient content was also a contributing factor to the observed differences in the SDA. The crabs did not eat the prepared meals as readily as the natural food items and as they are messy feeders there was a large variation in the amount of food eaten. The lack of significant differences in the SDA response as a function of nutrient content was likely due to differences in amount of food eaten, which is a major factor determining the SDA response. The differences in SDA when consuming natural food items were likely due to a combination of the costs of mechanical digestion, variation in nutrient content and food

  12. An integrated approach for prospectively investigating a mode-of-action for rodent liver effects

    SciTech Connect

    LeBaron, Matthew J.; Geter, David R.; Rasoulpour, Reza J.; Gollapudi, B. Bhaskar; Thomas, Johnson; Murray, Jennifer; Kan, H. Lynn; Wood, Amanda J.; Elcombe, Cliff; Vardy, Audrey; McEwan, Jillian; Terry, Claire; Billington, Richard

    2013-07-15

    Registration of new plant protection products (e.g., herbicide, insecticide, or fungicide) requires comprehensive mammalian toxicity evaluation including carcinogenicity studies in two species. The outcome of the carcinogenicity testing has a significant bearing on the overall human health risk assessment of the substance and, consequently, approved uses for different crops across geographies. In order to understand the relevance of a specific tumor finding to human health, a systematic, transparent, and hypothesis-driven mode of action (MoA) investigation is, appropriately, an expectation by the regulatory agencies. Here, we describe a novel approach of prospectively generating the MoA data by implementing additional end points to the standard guideline toxicity studies with sulfoxaflor, a molecule in development. This proactive MoA approach results in a more robust integration of molecular with apical end points while minimizing animal use. Sulfoxaflor, a molecule targeting sap-feeding insects, induced liver effects (increased liver weight due to hepatocellular hypertrophy) in an initial palatability probe study for selecting doses for subsequent repeat-dose dietary studies. This finding triggered the inclusion of dose-response investigations of the potential key events for rodent liver carcinogenesis, concurrent with the hazard assessment studies. As predicted, sulfoxaflor induced liver tumors in rats and mice in the bioassays. The MoA data available by the time of the carcinogenicity finding supported the conclusion that the carcinogenic potential of sulfoxaflor was due to CAR/PXR nuclear receptor activation with subsequent hepatocellular proliferation. This MoA was not considered to be relevant to humans as sulfoxaflor is unlikely to induce hepatocellular proliferation in humans and therefore would not be a human liver carcinogen. - Highlights: • We prospectively generated MoA data into standard guideline toxicity studies. • A proactive MoA approach

  13. Comparative effects of clarithromycin on action potential and ionic currents from rabbit isolated atrial and ventricular myocytes.

    PubMed

    Gluais, Pascale; Bastide, Michìle; Caron, Jacques; Adamantidis, Monique

    2003-04-01

    Prolongation of QT interval by several antibacterial drugs is an unwanted side effect that may be associated with development of ventricular arrhythmias. The macrolide antibacterial agent clarithromycin has been shown to cause QT prolongation. To determine the electrophysiologic basis for this arrhythmogenic potential, we investigated clarithromycin effects on (i). action potentials recorded from rabbit Purkinje fibers and atrial and ventricular myocardium using conventional microelectrodes and (ii). potassium and calcium currents recorded from rabbit atrial and ventricular isolated myocytes using whole-cell patch clamp recordings. We found that (i). clarithromycin (3-100 microM) exerted concentration-dependent lengthening effects on action potential duration in all tissues, with higher efficacy and reverse frequency-dependence in Purkinje fibers. However, clarithromycin did not cause development of early afterdepolarizations, and the parameters other than action potential duration were almost unaffected; (ii). clarithromycin (10-100 microM) reduced the delayed rectifier current. Significant blockade (approximately 30%) was found at the concentration of 30 microM. At 100 microM, it decreased significantly the maximum peak of the calcium current amplitude but failed to alter the transient outward and inwardly rectifier currents. It was concluded that these effects might be an explanation for the QT prolongation observed in some patients treated with clarithromycin.

  14. Effects of action observation on corticospinal excitability: Muscle specificity, direction, and timing of the mirror response.

    PubMed

    Naish, Katherine R; Houston-Price, Carmel; Bremner, Andrew J; Holmes, Nicholas P

    2014-11-01

    Many human behaviours and pathologies have been attributed to the putative mirror neuron system, a neural system that is active during both the observation and execution of actions. While there are now a very large number of papers on the mirror neuron system, variations in the methods and analyses employed by researchers mean that the basic characteristics of the mirror response are not clear. This review focuses on three important aspects of the mirror response, as measured by modulations in corticospinal excitability: (1) muscle specificity; (2) direction; and (3) timing of modulation. We focus mainly on electromyographic (EMG) data gathered following single-pulse transcranial magnetic stimulation (TMS), because this method provides precise information regarding these three aspects of the response. Data from paired-pulse TMS paradigms and peripheral nerve stimulation (PNS) are also considered when we discuss the possible mechanisms underlying the mirror response. In this systematic review of the literature, we examine the findings of 85 TMS and PNS studies of the human mirror response, and consider the limitations and advantages of the different methodological approaches these have adopted in relation to discrepancies between their findings. We conclude by proposing a testable model of how action observation modulates corticospinal excitability in humans. Specifically, we propose that action observation elicits an early, non-specific facilitation of corticospinal excitability (at around 90ms from action onset), followed by a later modulation of activity specific to the muscles involved in the observed action (from around 200ms). Testing this model will greatly advance our understanding of the mirror mechanism and provide a more stable grounding on which to base inferences about its role in human behaviour.

  15. From primed concepts to action: A meta-analysis of the behavioral effects of incidentally presented words.

    PubMed

    Weingarten, Evan; Chen, Qijia; McAdams, Maxwell; Yi, Jessica; Hepler, Justin; Albarracín, Dolores

    2016-05-01

    A meta-analysis assessed the behavioral impact of and psychological processes associated with presenting words connected to an action or a goal representation. The average and distribution of 352 effect sizes (analyzed using fixed-effects and random-effects models) was obtained from 133 studies (84 reports) in which word primes were incidentally presented to participants, with a nonopposite control group, before measuring a behavioral dependent variable. Findings revealed a small behavioral priming effect (dFE = 0.332, dRE = 0.352), which was robust across methodological procedures and only minimally biased by the publication of positive (vs. negative) results. Theory testing analyses indicated that more valued behavior or goal concepts (e.g., associated with important outcomes or values) were associated with stronger priming effects than were less valued behaviors. Furthermore, there was some evidence of persistence of goal effects over time. These results support the notion that goal activation contributes over and above perception-behavior in explaining priming effects. In summary, theorizing about the role of value and satisfaction in goal activation pointed to stronger effects of a behavior or goal concept on overt action. There was no evidence that expectancy (ease of achieving the goal) moderated priming effects. (PsycINFO Database Record

  16. A frame-dependent gravitational effective action mimics a cosmological constant, but modifies the black hole horizon

    NASA Astrophysics Data System (ADS)

    Adler, Stephen L.

    2016-06-01

    A frame-dependent effective action motivated by the postulates of three-space general coordinate invariance and Weyl scaling invariance exactly mimics a cosmological constant in Robertson-Walker spacetimes. However, in a static spherically symmetric Schwarzschild-like geometry it modifies the black hole horizon structure within microscopic distances of the nominal horizon, in such a way that g00 never vanishes. This could have important implications for the black hole “information paradox”.

  17. The effective action of a spin 1/2 field in the background of a nontopological soliton

    NASA Astrophysics Data System (ADS)

    Baacke, J.

    1990-12-01

    We generalize a new method of calculating the effective action for fields in a spherically symmetric background to the case of a spin 1/2 field whose mass is a function of r=| x|, as it is the case in the nontopological soliton model of Friedberg and Lee. The quantum corrections to the soliton energy are sizeable, of the same order as the bound state energies that stabilize the soliton.

  18. Computational modeling of inhibition of voltage-gated Ca channels: identification of different effects on uterine and cardiac action potentials

    PubMed Central

    Tong, Wing-Chiu; Ghouri, Iffath; Taggart, Michael J.

    2014-01-01

    The uterus and heart share the important physiological feature whereby contractile activation of the muscle tissue is regulated by the generation of periodic, spontaneous electrical action potentials (APs). Preterm birth arising from premature uterine contractions is a major complication of pregnancy and there remains a need to pursue avenues of research that facilitate the use of drugs, tocolytics, to limit these inappropriate contractions without deleterious actions on cardiac electrical excitation. A novel approach is to make use of mathematical models of uterine and cardiac APs, which incorporate many ionic currents contributing to the AP forms, and test the cell-specific responses to interventions. We have used three such models—of uterine smooth muscle cells (USMC), cardiac sinoatrial node cells (SAN), and ventricular cells—to investigate the relative effects of reducing two important voltage-gated Ca currents—the L-type (ICaL) and T-type (ICaT) Ca currents. Reduction of ICaL (10%) alone, or ICaT (40%) alone, blunted USMC APs with little effect on ventricular APs and only mild effects on SAN activity. Larger reductions in either current further attenuated the USMC APs but with also greater effects on SAN APs. Encouragingly, a combination of ICaL and ICaT reduction did blunt USMC APs as intended with little detriment to APs of either cardiac cell type. Subsequent overlapping maps of ICaL and ICaT inhibition profiles from each model revealed a range of combined reductions of ICaL and ICaT over which an appreciable diminution of USMC APs could be achieved with no deleterious action on cardiac SAN or ventricular APs. This novel approach illustrates the potential for computational biology to inform us of possible uterine and cardiac cell-specific mechanisms. Incorporating such computational approaches in future studies directed at designing new, or repurposing existing, tocolytics will be beneficial for establishing a desired uterine specificity of action

  19. The mass-action law based algorithm for cost-effective approach for cancer drug discovery and development

    PubMed Central

    Chou, Ting-Chao

    2011-01-01

    The mass-action law based system analysis via mathematical induction and deduction lead to the generalized theory and algorithm that allows computerized simulation of dose-effect dynamics with small size experiments using a small number of data points in vitro, in animals, and in humans. The median-effect equation of the mass-action law deduced from over 300 mechanism specific-equations has been shown to be the unified theory that serves as the common-link for complicated biomedical systems. After using the median-effect principle as the common denominator, its applications are mechanism-independent, drug unit-independent, and dynamic order-independent; and can be used generally for single drug analysis or for multiple drug combinations in constant-ratio or non-constant ratios. Since the “median” is the common link and universal reference point in biological systems, these general enabling lead to computerized quantitative bio-informatics for econo-green bio-research in broad disciplines. Specific applications of the theory, especially relevant to drug discovery, drug combination, and clinical trials, have been cited or illustrated in terms of algorithms, experimental design and computerized simulation for data analysis. Lessons learned from cancer research during the past fifty years provide a valuable opportunity to reflect, and to improve the conventional divergent approach and to introduce a new convergent avenue, based on the mass-action law principle, for the efficient cancer drug discovery and the low-cost drug development. PMID:22016837

  20. Nutridynamics: mechanism(s) of action of bioactive compounds and their effects.

    PubMed

    Serrano, Jose C E; Jove, Mariona; Gonzalo, Hugo; Pamplona, Reinald; Portero-Otin, Manuel

    2015-07-01

    Mechanism of action of bioactive compounds may be multiple, especially in the food matrix. Therefore, the interplay between these compounds and hosts' physiology, and the consequences of its continuous intake should be considered. In analogy with pharmacodynamics, the bioactive compounds should have both defined targets and mechanisms of action. However, several essential differences arise when considering the heterogeneous nature of the food matrix, the multiplicity of mechanisms and the variety of responses. In order to ascertain a potential mechanism of activity, one should consider both the intended use of the food, the biomarker that will support this claim and previous evidences, examined from current information sources. Once these have been examined, several experimental strategies should be considered, ranging from the choice of preclinical or experimental model, the use of samples from pilot interventional studies and the application of system's biology derived techniques, such as transcriptomics or metabolomics.

  1. Some new laser dyes: solvent effect on QE and lasing action

    SciTech Connect

    Padhye, M.R.; Varadarajan, T.S.; Deshpande, A.V.

    1982-08-01

    With a view to extend the tunability range and maximum output with the coumarin series of dyes, eleven new coumarins differing in the nature of substituents and their positions are synthesized. Two of these are found to be capable of laser action. Optical spectra and quantum efficiencies of these two dyes in various solvents are studied. Correlation between lasing capability structure of the dye and its optical characteristics is discussed.

  2. Multi-Scale Action Effectiveness Research in the Lower Columbia River and Estuary, 2012

    SciTech Connect

    Johnson, Gary E.; Sather, Nichole K.; Storch, Adam; Johnson, Jeff; Skalski, J. R.; Teel, D. J.; Brewer, Taylor; Bryson, Amanda J.; Dawley, Earl M.; Kuligowski, D. R.; Whitesel, T.; Mallette, Christine

    2013-11-30

    The study reported herein was conducted for the U.S. Army Corps of Engineers, Portland District (USACE) by researchers at the Pacific Northwest National Laboratory (PNNL), Oregon Department of Fish and Wildlife (ODFW), National Marine Fisheries Service (NMFS), University of Washington (UW), and U.S. Fish and Wildlife Service (USFWS). The goal of the study was to evaluate the ecological benefits of restoration actions for juvenile salmon in the lower Columbia River and estuary (LCRE; rkm 0–234).

  3. Effects of glucosamine infusion on insulin secretion and insulin action in humans.

    PubMed

    Monauni, T; Zenti, M G; Cretti, A; Daniels, M C; Targher, G; Caruso, B; Caputo, M; McClain, D; Del Prato, S; Giaccari, A; Muggeo, M; Bonora, E; Bonadonna, R C

    2000-06-01

    Glucose toxicity (i.e., glucose-induced reduction in insulin secretion and action) may be mediated by an increased flux through the hexosamine-phosphate pathway. Glucosamine (GlcN) is widely used to accelerate the hexosamine pathway flux, independently of glucose. We tested the hypothesis that GlcN can affect insulin secretion and/or action in humans. In 10 healthy subjects, we sequentially performed an intravenous glucose (plus [2-3H]glucose) tolerance test (IVGTT) and a euglycemic insulin clamp during either a saline infusion or a low (1.6 micromol x min(-1) x kg(-1)) or high (5 micromol x min(-1) x kg(-1) [n = 5]) GlcN infusion. Beta-cell secretion, insulin (SI*-IVGTT), and glucose (SG*) action on glucose utilization during the IVGTT were measured according to minimal models of insulin secretion and action. Infusion of GlcN did not affect readily releasable insulin levels, glucose-stimulated insulin secretion (GSIS), or the time constant of secretion, but it increased both the glucose threshold of GSIS (delta approximately 0.5-0.8 mmol/l, P < 0.03-0.01) and plasma fasting glucose levels (delta approximately 0.3-0.5 mmol/l, P < 0.05-0.02). GlcN did not change glucose utilization or intracellular metabolism (glucose oxidation and glucose storage were measured by indirect calorimetry) during the clamp. However, high levels of GlcN caused a decrease in SI*-IVGTT (delta approximately 30%, P < 0.02) and in SG* (delta approximately 40%, P < 0.05). Thus, in humans, acute GlcN infusion recapitulates some metabolic features of human diabetes. It remains to be determined whether acceleration of the hexosamine pathway can cause insulin resistance at euglycemia in humans.

  4. Combination effect of ultrasound and shake as a mechanical action for textile cleaning.

    PubMed

    Gotoh, Keiko; Harayama, Kokoro; Handa, Keiko

    2015-01-01

    The ultrasonic cleaning of artificially soiled fabrics with and without shake was carried out in an aqueous anionic surfactant solution. The polyester, cotton and polyester/cotton (65/35) fabrics were soiled with oleic acid or carbon black as a model soil, and cleaned together with their original fabrics with applying ultrasound for 5min. The detergency and the soil redeposition were determined from the change in the Kubelka-Munk function of the soiled and original fabric surfaces due to the cleaning. For any fabric, the removal of oleic acid and carbon black from the soiled fabric and their redeposition onto the original fabric increased with increasing electric power consumption of ultrasound. When ultrasound and shake were applied at the same time, the detergency further increased for any electric power consumption. The maximum detergency obtained with combination of ultrasound 340W and shake 160spm was compared with detergency obtained with Wascator, a horizontal axis drum type washer. It was found that the ultrasound/shake combination cleaning enabled efficient removal of both soils from any fabric and the detergency of the polyester fabrics was comparable to that with Wascator. The mechanical action during the washing was evaluated by two mechanical action test pieces commercially available, which indicated that the ultrasound/shake combination cleaning provided gentle mechanical action to the fabric in comparison with the drum type washer. The SEM observations showed the damage of the fabric and fiber surfaces was negligibly small after the ultrasound/shake combination washing.

  5. The effect of action video game experience on task-switching

    PubMed Central

    Green, C.Shawn; Sugarman, Michael A.; Medford, Katherine; Klobusicky, Elizabeth; Daphne Bavelier

    2012-01-01

    There is now a substantial body of work demonstrating that action video game experience results in enhancements in a wide variety of perceptual skills. More recently, several groups have also demonstrated improvements in abilities that are more cognitive in nature, in particular, the ability to efficiently switch between tasks. In a series of four experiments, we add to this body of work, demonstrating that the action video game player advantage is not exclusively due to an ability to map manual responses onto arbitrary buttons, but rather generalizes to vocal responses, is not restricted to tasks that are perceptual in nature (e.g. respond to a physical dimension of the stimulus such as its color), but generalizes to more cognitive tasks (e.g. is a number odd or even), and is present whether the switch requires a goal-switch or only a motor switch. Finally, a training study establishes that the relationship between the reduction in switch cost and action game playing is causal. PMID:22393270

  6. The effect of action video game experience on task-switching.

    PubMed

    Green, C Shawn; Sugarman, Michael A; Medford, Katherine; Klobusicky, Elizabeth; Daphne Bavelier

    2012-05-01

    There is now a substantial body of work demonstrating that action video game experience results in enhancements in a wide variety of perceptual skills. More recently, several groups have also demonstrated improvements in abilities that are more cognitive in nature, in particular, the ability to efficiently switch between tasks. In a series of four experiments, we add to this body of work, demonstrating that the action video game player advantage is not exclusively due to an ability to map manual responses onto arbitrary buttons, but rather generalizes to vocal responses, is not restricted to tasks that are perceptual in nature (e.g. respond to a physical dimension of the stimulus such as its color), but generalizes to more cognitive tasks (e.g. is a number odd or even), and is present whether the switch requires a goal-switch or only a motor switch. Finally, a training study establishes that the relationship between the reduction in switch cost and action game playing is causal.

  7. The Effects of Action and Violence in Television Programs on the Social Behavior and Imaginative Play of Preschool Children.

    ERIC Educational Resources Information Center

    Huston-Stein, Aletha; And Others

    The independent contributions of action and violence in television programs to children's attention and social behavior were investigated. Pairs of preschool children were assigned to one of four television conditions (1) high action-high violence, (2) high action-low violence, (3) low action-low violence, or (4) no television. Action was defined…

  8. Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action

    PubMed Central

    Peck, Rebecca; Rella, Walter; Tudela, Julio; Aznar, Justo; Mozzanega, Bruno

    2016-01-01

    Background Recent studies have identified that levonorgestrel administered orally in emergency contraception (LNG-EC) is only efficacious when taken before ovulation. However, the drug does not consistently prevent follicular rupture or impair sperm function. Objective The present systematic review is performed to analyze and more precisely define the extent to which pre-fertilization mechanisms of action may explain the drug's efficacy in pregnancy avoidance. We also examine the available evidence to determine if pre-ovulatory drug administration may be associated with post-fertilization effects. Conclusion The mechanism of action of LNG-EC is reviewed. The drug has no ability to alter sperm function at doses used in vivo and has limited ability to suppress ovulation. Our analysis estimates that the drug's ovulatory inhibition potential could prevent less than 15 percent of potential conceptions, thus making a pre-fertilization mechanism of action significantly less likely than previously thought. Luteal effects (such as decreased progesterone, altered glycodelin levels, and shortened luteal phase) present in the literature may suggest a pre-ovulatory induced post-fertilization drug effect. Lay Summary Plan B is the most widely used emergency contraceptive available. It is important for patients and physicians to clearly understand the drug’s mechanism of action (MOA). The drug was originally thought to work by preventing fertilization. Recent research has cast doubt on this. Our review of the research suggests that it could act in a pre-fertilization capacity, and we estimate that it could prevent ovulation in only 15 percent or less of cases. The drug has no ability to alter sperm function and limited ability to suppress ovulation. Further, data suggest that when administered pre-ovulation, it may have a post-fertilization MOA. PMID:27833181

  9. Potential effect of CAD systems on the detection of actionable nodules in chest CT scans during routine reporting

    NASA Astrophysics Data System (ADS)

    Wormanns, Dag; Beyer, Florian; Butzbach, Arnauld; Zierott, Livia; Heindel, Walter

    2006-03-01

    The purpose of the presented study was to determine the impact of two different CAD systems used as concur-rent reader for detection of actionable nodules (>4 mm) on the interpretation of chest CT scans during routine reporting. Fifty consecutive MDCT scans (1 mm or 1.25 mm slice thickness, 0.8 mm reconstruction increment) were se-lected from clinical routine. All cases were read by a resident and a staff radiologist, and a written report was available in the radiology information system (RIS). The RIS report mentioned at least one actionable pulmonary nodule in 18 cases (50%) and did not report any pulmonary nodule in the remaining 32 cases. Two different recent CAD systems were independently applied to the 50 CT scans as concurrent reader with two radiologists: Siemens LungCare NEV and MEDIAN CAD-Lung. Two radiologists independently reviewed the CAD results and determined if a CAD result was a true positive or a false positive finding. Patients were classified into two groups: in group A if at least one actionable nodule was detected and in group B if no actionable nodules were found. The effect of CAD on routine reporting was simulated as set union of the findings of routine reporting and CAD thus applying CAD as concurrent reader. According to the RIS report group A (patients with at least one actionable nodule) contained 18 cases (36% of all 50 cases), and group B contained 32 cases. Application of a CAD system as concurrent reader resulted in detec-tion of additional CT scans with actionable nodules and reclassification into group A in 16 resp. 18 cases (radi-ologist 1 resp. radiologist 2) with Siemens NEV and in 19 resp. 18 cases with MEDIAN CAD-Lung. In seven cases MEDIAN CAD-Lung and in four cases Siemens NEV reclassified a case into group A while the other CAD system missed the relevant finding. Sensitivity on a nodule (>4 mm) base was .45 for Siemens NEV and .55 for MEDIAN CAD-Lung; the difference was not yet significant (p=.077). In our study use of CAD

  10. Transforming Conflict into Effective Action: A Case Study on the Effects of Anthropogenic Sound on Marine Mammals

    NASA Astrophysics Data System (ADS)

    Lewandowski, Jill K.

    Like many wicked environmental problems of our time, marine sound and its potential effects on marine mammals is characterized by high levels of scientific uncertainty, diversified values across many stakeholder groups, political and regulatory complexities, and a continually evolving ecological and social environment. Further, the history of conflict and the relationships between major actors has rooted the issue firmly in identity conflict where prejudices lead to avoidance of working together. What results is continuing controversy, failed management decisions, litigation and an increasing frustration by all parties on why a better solution cannot be found. Ultimately, the intractability of the issue is not about the science, nor will the science ever tame the issue on its own. Rather, the issue is intractable because of the conflict between people about the most appropriate path forward. It is then imperative to understand, address, and transform this conflict in order to move off the decision carousel toward improved conservation outcomes and sustainable decisions for all. This research used an explanatory case study approach to quantitatively and qualitatively investigate the context and reasoning underlying conflict on this issue. Three methods were used in order to triangulate the data, and thus add rigor, including: (1) a document review of 230 publications: (2) exploratory interviews with 10 collaborative action experts and semi-structured interviews with 58 marine mammals and sound stakeholders; and (3) participant review of selected analyses. Data elucidate how different stakeholder groups define the problem and potential solutions, how they see their role and view the role of other stakeholders, specific experiences that increased or decrease conflict, and design preferences for a collaborative effort. These data are combined with conflict transformation principles to provide recommendations for a collaborative, transformative framework designed to

  11. Effects of ONO-1101, a novel beta-antagonist, on action potential and membrane currents in cardiac muscle.

    PubMed

    Muraki, K; Nakagawa, H; Nagano, N; Henmi, S; Kawasumi, H; Nakanishi, T; Imaizumi, K; Tokuno, T; Atsuki, K; Imaizumi, Y; Watanabe, M

    1996-08-01

    Direct effects of ONO-1101 ¿(-)-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]methyl-3-[4-[(S) -2-hydroxy-3-(2-morpholino carbonylamino)ethylamino] propoxy]phenylpropionate monohydrochloride), a novel beta-antagonist, on action potential parameters and membrane currents, and its beta adrenoceptor antagonism were examined in cardiac muscle. Action potential-parameters in papillary muscle of reserpinized animals and membrane currents recorded from single myocytes obtained from guinea pig and rabbit hearts were not affected by 1 to 100 microM ONO-1101. On the other hand, ONO-1101 markedly inhibited the potentiation of Ca current by isoproterenol in single cardiac myocytes of the guinea pig. The concentration-response relationship of Ca current for isoproterenol was shifted to the right. This effect resembled that of esmolol, which is also a beta adrenoceptor antagonist. A Schild plot analysis revealed the slope and pA2 value of each antagonist (ONO-1101, 0.94, 8.0; and esmolol, 0.98, 7.3, respectively) and demonstrated that ONO-1101 is about 5 times more potent than esmolol as a beta-antagonist. Two other effects of isoproterenol: 1) potentiation of delayed rectifier K current and 2) activation of chloride current, were also inhibited by ONO-1101. The time required for 50% removal of beta-antagonism of ONO-1101 and esmolol after the washout was estimated as 4 and 6 min, respectively, in depolarized papillary muscle. These results suggest that ONO-1101 is a potent beta-antagonist whose effects were removed quickly by washout. When applied at what is thought to be a clinical dosage, ONO-1101 had no direct effects on action potential-parameters and membrane currents in cardiac muscle. These characteristics of ONO-1101 suggest that this agent may be effective in clinical use.

  12. Sharing a task or sharing space? On the effect of the confederate in action coding in a detection task.

    PubMed

    Guagnano, Delia; Rusconi, Elena; Umiltà, Carlo Arrigo

    2010-03-01

    Several studies showed a Simon effect when two participants sit close to each other and perform one of the two halves of a two-choice RT task. That is, each participant perform a go-nogo task. A Simon effect emerges, which instead is absent when the same go-nogo tasks are performed individually. Hence the terms were introduced of "social Simon task" and 'social Simon effect". As of now, the social Simon effect was observed with social Simon tasks that overtly gave the participants the impression of being performing in collaboration with another person. In the present study we show that the social Simon effect was present also when, in the social Simon task, the two participants did not actually collaborate. It is, however, absent when participants perform the social task outside of each other's peripersonal space (i.e., outside arm-reach). We argue that the social Simon effect does not necessarily imply a representation of the other's action, as previously suggested. The presence of an active confederate in peripersonal space might simply provide a reference for coding one's own action in space.

  13. Action physics

    NASA Astrophysics Data System (ADS)

    McGinness, Lachlan P.; Savage, C. M.

    2016-09-01

    More than a decade ago, Edwin Taylor issued a "call to action" that presented the case for basing introductory university mechanics teaching around the principle of stationary action [E. F. Taylor, Am. J. Phys. 71, 423-425 (2003)]. We report on our response to that call in the form of an investigation of the teaching and learning of the stationary action formulation of physics in a first-year university course. Our action physics instruction proceeded from the many-paths approach to quantum physics to ray optics, classical mechanics, and relativity. Despite the challenges presented by action physics, students reported it to be accessible, interesting, motivational, and valuable.

  14. Religion and action control: Faith-specific modulation of the Simon effect but not Stop-Signal performance.

    PubMed

    Hommel, Bernhard; Colzato, Lorenza S; Scorolli, Claudia; Borghi, Anna M; van den Wildenberg, Wery P M

    2011-08-01

    Previous findings suggest that religion has a specific impact on attentional processes. Here we show that religion also affects action control. Experiment 1 compared Dutch Calvinists and Dutch atheists, matched for age, sex, intelligence, education, and cultural and socio-economic background, and Experiment 2 compared Italian Catholics with matched Italian seculars. As expected, Calvinists showed a smaller and Catholics a larger Simon effect than nonbelievers, while performance of the groups was comparable in the Stop-Signal task. This pattern suggests that religions emphasizing individualism or collectivism affects action control in specific ways, presumably by inducing chronic biases towards a more "exclusive" or "inclusive" style of decision-making. Interestingly, there was no evidence that religious practice affects inhibitory skills.

  15. The effects of tert-butyl hydroperoxide on human erythrocyte membrane ion transport and the protective actions of antioxidants.

    PubMed

    Dwight, J F; Hendry, B M

    1996-05-30

    The oxidising actions of tert-butyl hydroperoxide (tBH) (0-3 mmol/l) on human erythrocyte membrane ion transport have been studied using measurements of 86Rb+ influx. Ouabain and bumetanide were used to distinguish Rb+ flux via the sodium pump (Na,K-ATPase), Na,K,2Cl cotransporter and through residual membrane permeability. The protective actions of antioxidants and related molecules (vitamin E, vitamin E acetate, Trolox, butylated hydroxytoluene (BHT) and dithioerythritol (DTE) were studied. The effects of tBH were concentration dependent and the mean residual (ouabain and bumetanide insensitive) Rb+ permeability was increased by a factor of 8.5 (S.E.M. 2.2, n = 15) by a 5-min exposure to 2 mmol/l tBH. This action was almost completely prevented by co-incubation with Trolox or BHT, and partially prevented by the presence of vitamin E or DTE. Incubation with 2 mmol/l tBH for 5 min increased intracellular Na+ by a factor of 1.8 (S.E.M. 0.1, n = 8) and reduced intracellular K+ by a factor of 0.93 (S.E.M. 0.03, n = 8). These effects were prevented by Trolox and partially prevented by vitamin E, whereas DTE and vitamin E acetate were ineffective. Incubation with 2 mmol/l tBH for 5 min reduced the mean apparent sodium pump Vmax by 43% (S.E.M. 4, n = 8). This effect was completely prevented by Trolox and partially prevented by vitamin E. Vitamin E acetate had no effect. The mean bumetanide-sensitive Rb+ influx via the Na,K,2Cl cotransporter was reduced by 30% (S.E.M. 8.7, n = 25) by a 5-min exposure to 2 mmol/l tBH. This action was variable and no significant actions of the antioxidants studied could be demonstrated. This study suggests that tBH-mediated oxidative damage occurs from a hydrophilic site and involves increased non-selective membrane cation permeability and inhibition of specific transport systems.

  16. Differential effects of cortical neurotrophic factors on development of lateral geniculate nucleus and superior colliculus neurons: anterograde and retrograde actions.

    PubMed

    Wahle, Petra; Di Cristo, Graziella; Schwerdtfeger, Gudrun; Engelhardt, Maren; Berardi, Nicoletta; Maffei, Lamberto

    2003-02-01

    Neurotrophins strongly affect visual system development and plasticity. However, the mode of delivery and targets of neurotrophin action are still under debate. For instance, cortical NT-4/5 (neurotrophin 4/5; Ntf4/5) was shown to rescue lateral geniculate nucleus (LGN) neurons from monocular deprivation-induced atrophy suggesting a retrograde action on thalamic afferents. It is still unclear whether LGN neurons respond to NT-4/5 and other neurotrophins during development in animals with normal vision. We now show that infusions of NT-4/5 and NGF (nerve growth factor) into visual cortex at the onset and the peak of the critical period accelerated LGN neuron growth. BDNF (brain-derived neurotrophic factor) was ineffective. The effects of neurotrophin on LGN development were clearly dissociated from the effects at cortical level because soma growth of cortical layer IV and VI neurons was strongly promoted by BDNF. NT-4/5 was only effective at the onset, but no longer at the peak of the critical period suggesting a switch in neurotrophin dependency for these cortical cell classes. To dissociate retrograde and anterograde effects of the TrkB ligands, we analyzed the stratum griseum superficiale (SGS) of the superior colliculus, a target of visual cortical efferents. Indeed, TrkB-expressing inhibitory SGS neurons responded to cortical NT-4/5 infusion with somatic growth. Strikingly, the TrkB-expressing excitatory tectothalamic calbindin neurons in the SGS did not respond. This demonstrated for the first time a selective cell type-specific anterograde action of NT-4/5 and suggested for the LGN that anterograde as well as retrograde effects contribute to soma size regulation. Strikingly, cortical infusion of the cytokine LIF, which affects development of visual cortex neurochemical architecture, transiently inhibited growth of neurons in LGN, cortical layer IV and VI and SGS. In summary, the study presents three important results. First, central neurons regulate soma size

  17. Inhaled dry-powder formoterol and salmeterol in asthmatic patients: onset of action, duration of effect and potency.

    PubMed

    Palmqvist, M; Persson, G; Lazer, L; Rosenborg, J; Larsson, P; Lötvall, J

    1997-11-01

    Salmeterol and formoterol are two long-acting beta2-agonists for inhalation, currently being used in clinical practice. The aim of the present study was to investigate the onset of action, duration of effect and potency of these two beta2-agonists in asthmatic patients. Patients (n=28) were included on the basis of salbutamol stepwise reversibility (100, 100 and 200 microg, given cumulatively; total reversibility > or =15%). In a double-blind placebo-controlled crossover study, the bronchodilating properties of formoterol 6, 12 and 24 microg were compared with the effects of salmeterol 50 microg. Formoterol was given via Turbuhaler and salmeterol via Diskhaler, and forced expiratory volume in one second (FEV1) was monitored during 12 h. Formoterol at all doses had a more rapid onset than salmeterol as judged from bronchodilation at 3 min after the dose. Formoterol at all doses had a similar duration of effect to salmeterol 50 microg, as judged from bronchodilation at 12 h after dose administration. When the relative potency of the two drugs was compared, salmeterol 50 microg was estimated to correspond to formoterol 9 microg (95% confidence interval: 3-19 microg). We confirm that formoterol and salmeterol are both long-acting beta2-agonists, but with some differences in effect profile. We confirm the more rapid onset of action of formoterol compared with salmeterol, and furthermore, no difference in duration of effect is evident.

  18. Decreased insulin sensitivity during dietary sodium restriction is not mediated by effects of angiotensin II on insulin action.

    PubMed

    Perry, Colin G; Palmer, Tim; Cleland, Steven J; Morton, Ian J; Salt, Ian P; Petrie, John R; Gould, Gwyn W; Connell, John M C

    2003-08-01

    We have previously reported that modest dietary sodium restriction, as advocated in management guidelines for diabetes, may reduce insulin sensitivity. It has since been suggested that this effect may be mediated via cross-talk between insulin and angiotensin II (AII)-stimulated intracellular second messengers. In order to assess the effect of 5 days of modest sodium restriction (to <80 mmol/day target sodium intake) on insulin sensitivity, 15 healthy males underwent a double-blind, placebo-controlled, randomized, cross-over euglycaemic hyperinsulinaemic clamp study. One phase was supplemented with sodium tablets and the other with matched placebo. Insulin sensitivity (M) was reduced during dietary sodium restriction [median M value, 10.2 mg/kg per min (interquartile range 9.50-13.85) versus 12.8 mg/kg per min (interquartile range 9.60-14.30), P <0.05]. To elucidate potential mechanisms that may explain this observation, we investigated the effect of AII on insulin action in isolated adipocytes obtained from healthy females. No effect of AII on insulin-mediated glucose transport or suppression of lipolysis was observed. In conclusion, despite the observation that dietary sodium restriction was associated with a median 15% reduction in insulin sensitivity, we found no evidence of a direct effect of AII on insulin action in human adipocytes.

  19. [Cytogenetic effects of separate and combined action of 232Th and Cd nitrates on Allum cepa root meristem cells].

    PubMed

    Evseeva, T I; Geras'kin, S A; Khramova, E S

    2001-01-01

    Effects of separate and combined action of 232Th and Cd on Allium cepa root tip cells were investigated. It has been shown that cytogenetic effects of 232Th results mainly from its ability to induce genome damages. Cadmium in the examined concentration does not induce chromosomal vagrants, and this effect is not intensified by the combined action of 232Th and Cd (with 232Th). Cd induced increased aberrations of chromosome type frequency (1.5 times more than in control group), and fragment frequence, while mitotic index was significantly decreased. While taking into consideration the frequency of anaphase--telophase damages, and the number of aberrations per cell, the combined effects of 232Th and Cd may be considered as synergic. The aberration type ratio, frequencies of bridges and fragments, and also the level of proliferative activity of 232Th and Cd in the presence of both ions were similar with the corresponding parameters obtained when Cd acted alone. Possible mechanisms of formation of 232Th and Cd synergic effects are discussed.

  20. Joint Action of a Pair of Rowers in a Race: Shared Experiences of Effectiveness Are Shaped by Interpersonal Mechanical States

    PubMed Central

    R’Kiouak, Mehdi; Saury, Jacques; Durand, Marc; Bourbousson, Jérôme

    2016-01-01

    The purpose of this study was to understand how a single pair of expert individual rowers experienced their crew functioning in natural conditions when asked to practice a joint movement for the first time. To fulfill this objective, we conducted a field study of interpersonal coordination that combined phenomenological and mechanical data from a coxless pair activity, to analyze the dynamics of the (inter)subjective experience compared with the dynamics of the team coordination. Using an enactivist approach to social couplings, these heterogeneous data were combined to explore the salience (and accuracy) of individuals’ shared experiences of their joint action. First, we determined how each rower experienced the continuous crew functioning states (e.g., feelings of the boat’s glide). Second, the phenomenological data helped us to build several categories of oar strokes (i.e., cycles), experienced by the rowers as either detrimentally or effectively performed strokes. Third, the mechanical signatures that correlated with each phenomenological category were tracked at various level of organization (i.e., individual-, interpersonal-, and boat-levels). The results indicated that (a) the two rowers did not pay attention to their joint action during most of the cycles, (b) some cycles were simultaneously lived as a salient, meaningful experience of either a detrimental (n = 15 cycles) or an effective (n = 18 cycles) joint action, and (c) the mechanical signatures diverged across the delineated phenomenological categories, suggesting that the way in which the cycles were experienced emerged from the variance in some mechanical parameters (i.e., differences in peak force level and mean force). Notably, the mechanical measures that helped to explain differences within the phenomenological categories were found at the interpersonal level of analysis, thus suggesting an intentional inter-personal mode of regulation of their joint action. This result is further challenged